Neurological Disorders

Coding Dimension ID: 
303
Coding Dimension path name: 
Neurological Disorders
Funding Type: 
Tools and Technologies II
Grant Number: 
RT2-01927
Investigator: 
ICOC Funds Committed: 
$1 816 157
Disease Focus: 
Alzheimer's Disease
Neurological Disorders
Stem Cell Use: 
iPS Cell
Cell Line Generation: 
iPS Cell
oldStatus: 
Active
Public Abstract: 

Elucidating how genetic variation contributes to disease susceptibility and drug response requires human Induced Pluripotent Stem Cell (hIPSC) lines from many human patients. Yet, current methods of hIPSC generation are labor-intensive and expensive. Thus, a cost-effective, non-labor intensive set of methods for hIPSC generation and characterization is essential to bring the translational potential of hIPSC to disease modeling, drug discovery, genomic analysis, etc.

Our project combines technology development and scaling methods to increase throughput and reduce cost of hiPSC generation at least 10-fold, enabling the demonstration, and criterion for success, that we can generate 300 useful hiPSC lines (6 independent lines each for 50 individuals) by the end of this project. Thus, we propose to develop an efficient, cost effective, and minimally labor-intensive pipeline of methods for hIPSC identification and characterization that will enable routine generation of tens to hundreds of independent hIPSC lines from human patients. We will achieve this goal by adapting two simple and high throughput methods to enable analysis of many candidate hIPSC lines in large pools. These methods are already working in our labs and are called "fluorescence cell barcoding" (FCB) and expression cell barcoding (ECB).

To reach a goal of generating 6 high quality hIPSC lines from one patient, as many as 60 candidate hIPSC colonies must be expanded and evaluated individually using labor and cost intensive methods. By improving culturing protocols, and implementing suitable pooled analysis strategies, we propose to increase throughput at least 10-fold with a substantial drop in cost. In outline, the pipeline we propose to develop will begin with the generation of 60 candidate hIPSC lines per patient directly in 96 well plates. All 60 will be analyzed for diagnostic hIPSC markers by FCB in 1 pooled sample. The 10 best candidates per patient will then be picked for expression and multilineage differentiation analyses with the goal of finding the best 6 from each patient for digital karyotype analyses. Success at 10-fold scaleup as proposed here may be the first step towards further scaleup once these methods are fully developed.

Aim 1: To develop a cost-effective and minimally labor-intensive set of methods/pipeline for the generation and characterization high quality hIPSC lines from large numbers of human patients. We will test suitability/develop a set of methods that allow inexpensive and rapid characterization of 60 candidate hIPSC lines per patient at a time.

Aim 2: To demonstrate/test/evaluate the success and cost-effectiveness of our pipeline by generating 6 high quality hIPSC lines from each of 50 human patients from [REDACTED]. We will obtain skin biopsies and expand fibroblasts from 50 patients, and generate and analyze a total of 6 independent hIPSC lines from each using the methods developed in Aim 1.

Statement of Benefit to California: 

Many Californians suffer from diseases whose origin is poorly understood, and which are not treatable in an effective or economically advantageous manner. Part of solving this problem relies upon elucidating how genetic variation contributes to disease susceptibility and drug response and better understanding disease mechanism. Achieving these goals can be accelerated through the use of human Induced Pluripotent Stem Cell (hIPSC) lines from many human patients. Yet, current methods of hIPSC generation are labor-intensive and expensive. Thus, a cost-effective, non-labor intensive set of methods for hIPSC generation and characterization is essential to bring the translational potential of hIPSC to disease modeling, drug discovery, genomic analysis, etc.

If successful, our project will lead to breakthroughs in understanding of disease, development of better therapies, and economic development in California as businesses that use our methods are launched. In addition, new therapies will bring cost-savings in healthcare to Californians, stimulate employment since Californians will be employed in businesses that develop and sell these therapies, and relieve much suffering from the burdens of chronic disease.

Progress Report: 
  • An important problem in stem cell and regenerative medicine research has been the ability to quickly and cheaply generate and characterize reprogrammed stem cells from defined human patients. The primary goal of our project is to address this need by developing new technologies that allow stem cell lines to be characterized in large mixed pools as opposed to one by one. Our new methods use flow cytometry and highly sensitive methods for detecting the activity of genes in the cell lines. We made excellent progress in the first year and reduced flow cytometry methods to practice taking advantage of a method called fluorescence cell barcoding. Methods for analyzing activity of genes and chromosome number are in progress and being tested. Our ultimate goal is to reduce cost tenfold and increase speed by about tenfold and our methods development is on track to accomplish this aim.
  • A key bottleneck in reprogramming technology to make induced pluripotent stem (IPS) cell lines is the ability to make large numbers of lines from large numbers of patients in a way that is cost effective and minimizes labor. Our project has focused primarily on dropping the cost of characterization of candidate lines. We have made a number of discoveries about the behavior of candidate reprogrammed lines that allow us to drop cost and labor needed for candidate reprogrammed line characterization. We measured the frequency of candidate lines that were well-behaved in a large retroviral reprogramming experiment, which allows us to rigorously estimate how many candidate lines must be picked and analyzed if 4-6 high-quality lines are to be generated for every patient fibroblast sample subjected to typical retroviral reprogramming technology. We then continued our work on developing a combination of different array and microfluidic chip technologies to measure the chromosome number in each candidate line and the ability of each line to be pluripotent, i.e., to be able to generate many different type of cells similar to embryonic stem cells. We are optimistic that our work will simplify and drop the cost of the characterization process so that it costs far less than before our work was initiated.
  • Reprogrammed stem cell lines, i.e., induced pluripotent stem cell lines, have the potential to revolutionize research into causes of disease and genetic contributions to the causes of disease. One key limitation, however, is the ability to generate large numbers of different stem cell lines from different people to sample the range of genetic variation in the human population as it relates to disease development. A key bottleneck is the speed and cost with which reprogrammed stem cell lines can be generated and validated for usefulness. We have succeeded in developing a streamlined workflow for characterization of reprogrammed stem cell lines that drops the cost for characterization from several thousand dollars to a few hundred dollars and increases the speed and number of lines that can be handled substantially. We take advantage of novel genetic characterization methods to analyze genetic stability and the pattern of gene expression as it reveals the capabilities of the stem cell lines. We are finishing up the loose ends on this project now and should have a high quality publication prepared for submission shortly that describes this simple and inexpensive workflow that we have developed with modern gene characterization methods.
Funding Type: 
Tools and Technologies II
Grant Number: 
RT2-01920
Investigator: 
ICOC Funds Committed: 
$1 833 054
Disease Focus: 
Neurological Disorders
Pediatrics
Stem Cell Use: 
iPS Cell
Cell Line Generation: 
iPS Cell
oldStatus: 
Active
Public Abstract: 

This study will use Ataxia-Telangiectasia (A-T), an early-onset inherited neurodegenerative disease of children, as a model to study the mechanisms leading to cerebellar neurodegeneration and to develop a drug that can slow or halt neurodegeneration. We will start with skin cells that were originally grown from biopsies of patients with A-T who specifically carry “nonsense” type of mutations in the ATM gene. We will convert these skin cells to stem cells capable of forming neural cells that are lacking in the brain (cerebellum) of A-T patients; presumably these neural cells need ATM protein to develop normally. We will then test the effects of our most promising new “readthrough compounds” (RTCs) on the newly-developed neural cells. Our lab has been developing the drugs over the past six years. At present, there is no other disease model (animal or in a test tube) for evaluating the effects of RTCs on the nervous system and its development. Nor is there any effective treatment for the children with A-T or other progressively-deteriorating ataxias. Success in this project would open up at least three new areas for understanding and treating neurodegenerative diseases: 1) the laboratory availability of human neural cells with specific disease-causing mutations; 2) a new approach to learning how the human brain develops and 3) a new class of drugs (RTCs) that correct nonsense mutations, even in the brain, and may correct neurodegeneration.

Statement of Benefit to California: 

This project seeks to merge the expertise of two major research cultures: one with long-standing experience in developing a treatment for a progressive childhood-onset disease called Ataxia-telangiectasia and another with recent success in converting skin cells into cells of the nervous system. California citizens will benefit by finding new ways to treat neurodegenerative diseases, like A-T, Parkinson and Alzheimer, and expanding the many possible applications of stem cell technology to medicine. More specifically, we will construct a new “disease in a dish” model for neurodegeneration, and this will enable our scientists to test the positive and negative effects of a new class of drugs for correcting inherited diseases/mutations directly on brain cells. These advances will drastically decrease drug development costs and will stimulate new biotech opportunities and increase tax revenues for California, while also training the next generation of young scientists to deliver these new medical products to physicians and patients within the next five years.

Progress Report: 
  • No effective treatments are available for most neurodegenerative diseases. This study uses Ataxia-Telangiectasia (A-T), an early-onset inherited neurodegenerative disease of children, as a model to study the mechanisms leading to cerebellar neurodegeneration and to develop a drug that can slow or halt neurodegeneration. Aim1 proposed to use “Yamanaka factors” to reprogram A-T patient-derived skin fibroblasts, which carry nonsense mutations that we have shown can be induced by RTCs to express full-length and functional ATM protein, into iPSCs. We have successfully reprogrammed A-T fibroblasts to hiPSCs and teratoma formation shows their pluripotency. Aim2 will use these established iPSCs to model neurodegeneration, focusing on differentiation to cerebellar cells, such as Purkinje cells and granule cells. We have generated the Purkinje cell promoter –driven GFP reporter system and will use this system to examine the differentiation capacity of A-T iPSCs to Purkinje cells. Aim3 will utilize the newly-developed neural cells carrying disease-causing ATM nonsense mutations as targets for evaluating the potential therapeutic effects of leading RTCs. We have already started to test the efficacy and toxicity of our lead RTC compounds on A-T iPSC-derived neural progenitor cells. The continuation of this study will help us to pick up one promising RTC compound for IND application. This project is on the right track towards its objective for the development of disease models with hiPSCs and the test of our lead small molecule compounds for the treatment of A-T or other neurodegenerative diseases.
  • No effective treatments are available for most neurodegenerative diseases. This study uses Ataxia-Telangiectasia (A-T), an early-onset inherited neurodegenerative disease of children, as a model to study the mechanisms leading to cerebellar neurodegeneration and to develop a drug that can slow or halt neurodegeneration. Aim1 proposed to use “Yamanaka factors” to reprogram A-T patient-derived skin fibroblasts, which carry nonsense mutations that we have shown can be induced by RTCs to express full-length and functional ATM protein, into iPSCs. Aim2 will use these established iPSCs to model neurodegeneration, focusing on differentiation to cerebellar cells, such as Purkinje cells and granule cells. Aim3 will utilize the newly-developed neural cells carrying disease-causing ATM nonsense mutations as targets for evaluating the potential therapeutic effects of leading RTCs.
  • During the past two years of this project, we established Ataxia-telangiectasia (A-T) patient-derived iPSC lines from two patients which contain nonsense mutations and splicing mutations. These two lines are currently used for testing the mutation-targeted therapies with small molecule readthrough (SMRT) compounds and antisense morpholino oligonucleotides (AMOs). Manuscript describing this work was recently accepted, showing that SMRT compounds can abrogate phenotypes of A-T iPSC-derived neural cells
  • This is the third year (last year) progress report. During the first two years of this project, we have already established two Ataxia-telangiectasia (A-T) patient-derived iPSC lines which contain nonsense mutations and splicing mutations, respectively. These two lines are currently used for testing the mutation-targeted therapies with small molecule readthrough (SMRT) compounds and antisense morpholino oligonucleotides (AMOs). In the third year, we have formally published our results from the first two years’ research work in Nature Communications (Lee et al., 2013). In the last year, we continue to make progresses in the characterization of A-T iPSCs and their derived neuronal cells as well as developing the mutation-targeted therapies for neurodegeneration diseases
Funding Type: 
Tools and Technologies II
Grant Number: 
RT2-01906
Investigator: 
Institution: 
Type: 
PI
ICOC Funds Committed: 
$1 884 808
Disease Focus: 
Autism
Neurological Disorders
Pediatrics
Stem Cell Use: 
iPS Cell
Cell Line Generation: 
iPS Cell
oldStatus: 
Active
Public Abstract: 

Autism Spectrum Disorders (ASDs) are a heritable group of neuro-developmental disorders characterized by language impairments, difficulties in social integrations, and the presence of stereotyped and repetitive behaviors. There are no treatments for ASDs, and very few targets for drug development. Recent evidence suggests that some types of ASDs are caused by defects in calcium signaling during development of the nervous system. We have identified cellular defects in neurons derived from induced pluripotent stem cells (iPSCs) from patients with Timothy Syndrome (TS), caused by a rare mutation in a calcium channel that leads to autism. We propose to use cells carrying this mutant calcium channel to identify drugs that act on calcium signaling pathways that are involved in ASDs.

Our research project has three aims. First, we will determine whether known channel modulators reverse the cellular defects we observe in cells from TS patients. It is possible that we will find that existing drugs already approved for use in humans might be effective for treating this rare but devastating disorder.

Our second aim is to determine whether screens using neuronal cells derived from ASD patients can be used to identify calcium signaling modulators. A bottleneck to therapy development for ASDs has been the lack of appropriate in vitro models for these disorders, and we would like to determine whether our studies could serve as the basis for a new type of screen in human neurons.

Our third aim is to identify signaling molecules that might be affected in patients with ASDs, which could be targets for future drug discovery. There is increasing evidence that several types of ASDs are caused by defects in neuronal activity and calcium signaling. More specifically, the CaV1.2 calcium channel that we are studying has been implicated in syndromic and non-syndromic forms of autism, and also in schizophrenia and bipolar disorder. One of the more exciting aspects of our screen of neurons with a mutation in CaV1.2 is that it gives us a tool to explore calcium-mediated signaling pathways that are defective in ASDs. We will try to modify calcium signaling in neurons from ASD patients by changing the expression of proteins that are known to affect calcium signaling in other contexts. These experiments will identify targets that are active in human neurons and that affect cellular phenotypes that are defective in ASD.

In summary, the work described in this proposal constitutes a critical step to fulfilling the promise that reprogramming of patient-specific cells offers for the treatment of neuropsychiatric disorders such as autism. Our studies will identify lead compounds that could be tested in the clinic for a rare form of autism, and novel molecular targets for therapeutic development in the future. Importantly, these studies will provide a proof of principle that iPSC-derived cells are valuable for drug discovery for neuropsychiatric disorders.

Statement of Benefit to California: 

Autism Spectrum Disorders (ASDs) affect approximately 1 in 110 children in California. In addition to the devastating effects that ASDs have on the families of affected individuals, treating and educating people with ASDs imposes a heavy economic burden on the state. In 2007, almost 35,000 individuals with autism were receiving services from the California Regional Centers, and the number was expected to rise to 50,000 by last year. Recent estimates suggest that the lifetime cost of caring for an individual with an ASD can exceed $3 million.

In spite of their impact on our society, there are currently no effective therapies for ASDs. Our lack of cellular and molecular tools to study these disorders means that there are no good targets for drug screening, so there are very limited prospects for developing effective pharmacological treatments in the near future. New drug discovery paradigms are needed to help develop therapies for these neuropsychiatric conditions.

The research described in this proposal could have a dramatic impact on drug discovery methods for ASDs. First, we hope to identify drugs that are effective in treating Timothy Syndrome, a rare form of autism caused by an electrophysiological defect in a calcium channel. Second, we aim to develop new tools to explore calcium-mediated signaling pathways that are defective in ASDs. If successful, our research will identify a family of molecular targets that will be useful for developing therapies for ASDs in the future.

Progress Report: 
  • Autism Spectrum Disorders (ASDs) are a heritable group of neuro-developmental disorders characterized by language impairments, difficulties in social integrations, and the presence of stereotyped and repetitive behaviors. There are no treatments for ASDs, and very few targets for drug development. The goal of this CIRM project is to develop a series of in vitro screens for drugs that might affect the underlying cellular defects in ASDs.
  • Since ASDs are uniquely human, we proposed to design, optimize and conduct high-throughput chemical screens using human neurons derived from induced pluripotent stem cells (iPSCs). Our lab identified cellular defects in neurons derived from patients with Timothy Syndrome (TS), a syndromic disorder often presenting with autism that is caused by a rare mutation in a calcium channel. In our project, we proposed to develop in vitro screening assays for ASDs based on these TS phenotypes, and to screen these assays to identify drugs that might affect behavioral symptoms of autism. In the first year of this award, we conducted preliminary screens and found that certain calcium channel modulators reverse some of the differentiation defects that we observe in these cells. We also extended observations that we had made in mice and showed that TS neurons have defects in the structure and length of their dendrites, measurable features that we can use as the basis for additional drug screens. We have therefore progressed within the aims of the original award.
  • For the remainder of the grant, however, we are proposing to broaden the scope of this project to include iPSC-based screens using neurons from patients with more prevalent forms of ASDs. In other research in our lab, we have characterized phenotypes in neurons derived from patients with two other diseases that are more prevalent than TS: DiGeorge Syndrome (DGS) and Phelan-McDermid Syndrome (PMDS), two neurodevelopmental disorders resulting from deletions within chromosome 22 and patients present symptoms that often include autism. We have shown that these cells have defects in the length of their dendrites, in the structure and function of their synapses, and in their ability to transmit electrical impulses. We propose to broaden the scope of our work to develop screens for TS, DGS, and PMDS. These screens will serve as a basis for identifying drugs that lessen or reverse cellular defects in these disorders, and thus may lead to more generalized treatments for ASDs.
  • We believe that this research not only fulfills critical steps in the development of a novel test for potential ASD treatments, but demonstrates the power of iPSC technology for understanding the underlying mechanisms of neurological disorders. Expanding the scope of our original project will help us increase the impact of our studies on therapeutic development and on the understanding of the neurobiology of ASDs.
  • Autism Spectrum Disorders (ASDs) are a heritable group of neurodevelopmental disorders that affect the verbal, social, and behavioral abilities of affected individuals. There are no pharmacological treatments for ASDs, in part because of a lack of validated cellular and animal models for use in drug screens. The goal of this project is to develop and validate a cell-based high throughput screening method that we will use to identify therapies for ASDs.
  • Our laboratory has established methods for collecting skin samples from patients and reprogramming these cells into induced pluripotent stem (iPS) cells, which we then differentiate into neurons. We have characterized neurons from patients with ASDs, and identified cellular phenotypes that are amenable to high-throughput methods to identify drug targets. Our efforts in Year 2 of our CIRM funding have focused on Phelan-McDermid Syndrome (PMDS), an inherited progressive neurodevelopmental disorder characterized by developmental delay, absent or severely impaired speech, and an increased risk of autism. We have discovered that neurons from PMDS patients who have autism have defects in excitatory synaptic transmission caused by the loss of one copy of the gene Shank3. Shank3 lies in the region of Chromosome 22 that is deleted in PMDS, and is important for the development of synapses. Based on our studies, PMDS neurons can be distinguished from their wildtype counterparts by low expression levels of Shank3 measured by quantitative PCR, decreased number of excitatory synapses labeled by immunocytochemistry and imaged with a microscope, and reduced excitatory cellular currents measured electrophysiologically. Each of these phenotypes is amenable to high throughput screening of therapeutic compounds. We tested several candidate therapeutics and found that prolonged treatment with the growth factor IGF-1 partially reverses the defects we have discovered in PMDS neurons. While IGF-1 is highly bioactive and therefore not an ideal drug candidate, it can be used to validate our screening method.
  • We are currently running trials to select the best phenotype and assay for larger-scale screening. In parallel, we have developed protocols to culture large numbers of iPSC-derived neurons for high throughput screens, and we are growing and banking working stocks of PMDS and control neurons. These experiments will help us identify drug candidates for PMDS, and will represent a significant advance in HTS approaches for the testing of ASD therapies using iPSC-based systems.
  • Autism Spectrum Disorders (ASDs) are a heritable group of neurodevelopmental disorders that affect the verbal, social, and behavioral ability of affected in individual. There are no treatments for ASD, in part because the biological basis for the disorders are not know. In addition, there are no methods for screening drugs that may be therapeutic. The goal of this project was to develop screening assays based on stem cells that were derived from individuals with autism.
  • Using skin samples from affected individuals, our laboratory was able to generate induced pluripotent stem cells (iPSC) and use these stem cells to generate neurons. With CIRM support, we have now generated iPSC from many individuals, some of whom carry genetic alterations that cause autism. Work under this award focused on two genetic disorders, Timothy Syndrome (TS) and Phelan-McDermid Syndrome (PMDS). Both are inherited syndromes that affect several body systems and also greatly increase the risk of autism. In each case, we found that neurons from affected individuals displayed changes in the way neurons connect and communicate. The effects were pronounced in PMDS neurons, in part due to the loss of the Shank3 gene that is involved in the function of the excitatory synapse. Work in year 3 has focused on identifying a robust alteration in neuron function that can be used for drug screening.
  • One such phenotype was discovered and involves a change in the way calcium is utilized when neurons communicate by generating an electrical current. Using chemicals that detect calcium, fluorescent assays were developed that show a robust difference in calcium response in PMDS neurons relative to neurons from unaffected individuals. Adapting the fluorescent calcium reporter assay to a high-throughput format also required the invention of new stem cell culture methods for generating neurons that were more efficient and less costly. Ultimately, a novel strategy was developed that now permits the production of very large numbers of neurons that can be assayed in high throughput screens. A limited screen using candidate drugs has confirmed the utility of the assay and future work will utilize these assays in large scale screens for drugs that normalize or augment the synaptic defects.
Funding Type: 
Tools and Technologies II
Grant Number: 
RT2-01881
Investigator: 
ICOC Funds Committed: 
$1 825 613
Disease Focus: 
Stroke
Neurological Disorders
Stem Cell Use: 
iPS Cell
oldStatus: 
Active
Public Abstract: 

Stroke is the leading cause of adult disability. Most patients survive their initial stroke, but do not recover fully. Because of incomplete recovery, up to 1/3 of stroke patients are taken from independence to a nursing home or assisted living environment, and most are left with some disability in strength or control of the arms or legs. There is no treatment that promotes brain repair and recovery in this disease. Recent studies have shown that stem cell transplantation into the brain can promote repair and recovery in animal models of stroke. However, a stem cell therapy for stroke has not reached the clinic. There are at least three limitations to the development of a human stroke stem cell therapy: most of the transplanted cells die, most of the cells that survive do not interact with the surrounding brain, and the process of injecting stem cells into the brain may damage the normal brain tissue that is near the stroke site. The studies in this grant develop a novel investigative team and research approach to achieve a solution to these limits. Using the combined expertise of engineering, stem cell biology and stroke scientists the studies in this grant will develop tissue bioengineering systems for a stem cell therapy in stroke. The studies will develop a biopolymer hydrogel that provides a pro-growth and pro-survival environment for stem cells when injected with them into the brain. This approach has three unique aspects. First, the hydrogel system utilizes biological components that mimic the normal brain environment and releases specific growth factors that enhance transplanted stem cell survival. Second, these growth factors will also likely stimulate the normal brain to undergo repair and recovery, providing a dual mechanism for neural repair after stroke. Third, this approach allows targeting of the stroke cavity for a stem cell transplant, and not normal brain. The stroke cavity is an ideal target for a stroke stem cell therapy, as it is a cavity and can receive a stem cell transplant without displacing normal brain, and it lies adjacent to the site in the brain of most recovery in this disease—placing the stem cell transplant near the target brain region for repair in stroke.
The progress from stroke stem cell research has identified stem cell transplantation as a promising treatment for stroke. The research in this grant develops a next generation in stem cell therapies for the brain by combining new bioengineering techniques to develop an integrated hydrogel/stem cell system for transplantation, survival and neural repair in this disease.

Statement of Benefit to California: 

Advances in the early treatment of stroke have led to a decline in the death rate from this disease. At the same time, the overall incidence of stroke is projected to substantially increase because of the aging population. These two facts mean that stroke will not be lethal, but instead produce a greater number of disabled survivors. A 2006 estimate placed over half of the annual cost in stroke as committed to disabled stroke survivors, and exceeding $30 billion per year in the United States. The studies in this grant develop a novel stem cell therapy in stroke by focusing on one major bottleneck in this disease: the inability of most stem cell therapies to survive and repair the injured brain. With its large population California accounts for roughly 24% of all stroke hospital discharges in the Unites States. The development of a new stem cell therapy approach for this disease will lead to a direct benefit to the State of California.

Progress Report: 
  • This grant develops a tissue bioengineering approach to stem cell transplantation as a treatment for brain repair and recovery in stroke. Stem cell transplantation has shown promise as a therapy that promotes recovery in stroke. Stem cell transplantation in stroke has been limited by poor survival of the transplanted cells. The studies in this grant utilize a multidisciplinary team of bioengineers, neuroscientists/neurologists and stem cell biologists to develop an approach in which stem or progenitor cells can be transplanted into the site of the stroke within a biopolymer hydrogel that provides an environment which supports cell survival and treatment of the injured brain. These hydrogels need to contain naturally occurring brain molecules, so that they do not release foreign or toxic components when they degrade. Further, the hydrogels have to remain liquid so that the injection approach can be minimally invasive, and then gel within the brain. In the past year the fundamental properties of the hydrogels have been determined and the optimal physical characteristics, such as elasticity, identified. Hydrogels have been modified to contain molecules which stem or progenitor cells will recognize and support survival, and to contain growth factors that will both immediately release and, using a novel nanoparticle approach, more slowly release. These have been tested in culture systems and advanced to testing in rodent stroke models. This grant also tests the concept that the stem/progenitor cell that is more closely related to the area within the brain that receives the transplant will provide a greater degree of neural repair and recovery. Progress has been made in the past year in differentiating induced pluripotent stem cells along a lineage that more closely resembles the part of the brain injured in this stroke model, the cerebral cortex.
  • This grant determines the effect of a tissue bioengineering approach to stem cell survival and engraftment after stroke, as means of improving functional recovery in this disease. Stem cell transplantation in stroke has been limited by the poor survival of transplanted cells and their lack of differentiation in the brain. These studies use a biopolymer hydrogel, made of naturally occurring molecules, to provide a pro-survival matrix to the transplanted cells. The studies in the past year developed the chemical characteristics of the hydrogel that promote survival of the cells. These characteristics include the modification of the hydrogel so that it contains specific amounts of protein signals which resemble those seen in the normal stem cell environment. Systematic variation of the levels of these protein signals determined an optimal concentration to promote stem cell survival in vitro. Next, the studies identified the chemistry and release characteristics from the hydrogel of stem cell growth factors that normally promotes survival and differentiation of stem cells. Two growth factors have been tested, with the release characteristics more completely defined with one specific growth factor. The studies then progressed to determine which hydrogels supported stem cell survival in vivo in a mouse model of stroke. Tests of several hydrogels determined that some provide poor cell survival, but one that combines the protein signals, or “motifs”, that were studied in vitro provided improved survival in vivo. These hydrogels did not provoke any additional scarring or inflammation in surrounding tissue after stroke. Studies in the coming year will now determine if these stem cell/hydrogel matrices promote recovery of function after stroke, testing both the protein motif hydrogels and those that contain these motifs plus specific growth factors.
  • This grant determines the effect of a tissue bioengineering approach to stem cell survival and engraftment after stroke, as means of improving functional recovery in this disease. Stem cell transplantation in stroke has been limited by the poor survival of transplanted cells and their lack of differentiation in the brain. These studies use a biopolymer hydrogel, made of naturally occurring molecules, to provide a pro-survival matrix to the transplanted cells. The studies in past years developed the two chemical characteristics of hydrogels that contain recognition or signal elements for stem cells: “protein motifs” that resemble molecules in the normal stem cell environment and growth factors that normally communicate to stem cells in the brain. The hydrogels were engineered so that they contain these familiar stem cell protein motifs and growth factors and release the growth factors over a slow and sustained time course. In the past year on this grant, we tested the effects of hydrogels that had the combined characteristics of these protein motifs and growth factors, at varying concentrations, for their effect on induced pluripotent neural precursor cells (iPS-NPCs) in culture. We identified an optimum concentration for cell survival and for differentiation into immature neurons. We then initiated studies of the effects of this optimized hydrogel in vivo in a mouse model of stroke. These studies are ongoing. They will determine the cell biological effect of this hydrogel on adjacent tissue and on the transplanted cells—determining how the hydrogel enhances engraftment of the transplant. The behavioral studies, also under way, will determine if this optimized hydrogel/iPS-NPC transplant enhances recovery of movement, or motor, function after stroke.
Funding Type: 
Tools and Technologies II
Grant Number: 
RT2-01880
Investigator: 
Institution: 
Type: 
PI
ICOC Funds Committed: 
$1 619 627
Disease Focus: 
Parkinson's Disease
Neurological Disorders
Stem Cell Use: 
iPS Cell
Cell Line Generation: 
iPS Cell
Embryonic Stem Cell
oldStatus: 
Active
Public Abstract: 

The objective of this study is to develop a new, optimized technology to obtain a homogenous population of midbrain dopaminergic (mDA) neurons in a culture dish through neuronal differentiation. Dopaminergic neurons of the midbrain are the main source of dopamine in the mammalian central nervous system. Their loss is associated with one of the most prominent human neurological disorders, Parkinson's disease (PD). There is no cure for PD, or good long-term therapeutics without deleterious side effects. Therefore, there is a great need for novel drugs and therapies to halt or reverse the disease.

Recent groundbreaking discoveries allow us to use adult human skin cells, transduce them with specific genes, and generate cells that exhibit virtually all characteristics of embryonic stem cells, termed induced pluripotent stem cells (iPSCs). These cell lines, when derived from PD patient skin cells, can be used as an experimental pre-clinical model to study disease mechanisms unique to PD. These cells will not only serve as an ‘authentic’ model for PD when further differentiated into the specific dopaminergic neurons, but that these cells are actually pathologically affected with PD.

All of the current protocols for directed neuronal differentiation from iPSCs are lengthy and suboptimal in terms of efficiency and reproducibility of defined cell populations. This hinders the ability to establish a robust model in-a-dish for the disease of interest, in our case PD-related neurodegeneration. We will use a new, efficient gene integration technology to induce expression of midbrain specific transcription factors in iPSC lines derived from a patient with PD and a sibling control. Forced expression of these midbrain transcription factors will direct iPSCs to differentiate into DA neurons in cell culture. We aim at achieving higher efficiency and reproducibility in generating a homogenous population of midbrain DA neurons, which will lay the foundation for successfully modeling PD and improving hit rates of future drug screening approaches. Our study could also set a milestone towards the establishment of efficient, stable, and reproducible neuronal differentiation using a technology that has proven to be safe and is therefore suitable for cell replacement therapies in human.

The absence of cellular models of Parkinson’s disease represents a major bottleneck in the scientific field of Parkinson’s disease, which, if solved, would be instantly translated into a wide range of clinical applications, including drug discovery. This is an essential avenue if we want to offer our patients a new therapeutic approach that can give them a near normal life after being diagnosed with this progressively disabling disease.

Statement of Benefit to California: 

The proposed research could lead to a robust model in-a-dish for Parkinson’s disease (PD)-related neurodegeneration. This outcome would deliver a variety of benefits to the state of California.

First, there would be a profound personal impact on patients and their families if the current inevitable decline of PD patients could be halted or reversed. This would bring great happiness and satisfaction to the tens of thousands of Californians affected directly or indirectly by PD.

Progress toward a cure for PD is also likely to accelerate the development of treatments for other degenerative disorders. The technology for PD modeling in-a-dish could be applied to other cell types such as cardiomyocytes (for heart diseases) and beta-cells (for diabetes). The impact would likely stimulate medical progress on a variety of conditions in which stem cell based drug screening and therapy could be beneficial.

An effective drug and therapy for PD would also bring economic benefits to the state. Currently, there is a huge burden of costs associated with the care of patients with long-term degenerative disorders like PD, which afflict tens of thousands of patients statewide. If the clinical condition of these patients could be improved, the cost of maintenance would be reduced, saving billions in medical costs. Many of these patients would be more able to contribute to the workforce and pay taxes.

Another benefit is the effect of novel, cutting-edge technologies developed in California on the business economy of the state. Such technologies can have a profound effect on the competitiveness of California through the formation of new manufacturing and health care delivery facilities that would employ California citizens and bring new sources of revenue to the state.

Therefore, this project has the potential to bring health and economic benefits to California that is highly desirable for the state.

Progress Report: 
  • Dopaminergic (DA) neurons of the midbrain are the main source of dopamine in the mammalian central nervous system. Their loss is associated with a prominent human neurological disorder, Parkinson's disease (PD). There is no cure for PD, nor are there any good long-term therapeutics without deleterious side effects. Therefore, there is a great need for novel therapies to halt or reverse the disease. The objective of this study is to develop a new technology to obtain a purer, more abundant population of midbrain DA neurons in a culture dish. Such cells would be useful for disease modeling, drug screening, and development of cell therapies.
  • Recent discoveries allow us to use adult human skin cells, introduce specific genes into them, and generate cells, termed induced pluripotent stem cells (iPSC), that exhibit the characteristics of embryonic stem cells. These iPSC, when derived from PD patient skin cells, can be used as an experimental model to study disease mechanisms that are unique to PD. When differentiated into DA neurons, and these cells are actually pathologically affected with PD.
  • The current methods for directed DA neuronal differentiation from iPSC are inadequate in terms of efficiency and reproducibility. This situation hinders the ability to establish a robust model for PD-related neurodegeneration. In this study, we use a new, efficient gene integration technology to induce expression of midbrain-specific genes in iPSC lines derived from a patient with PD and a normal sibling. Forced expression of these midbrain transcription factor genes directs iPSC to differentiate into DA neurons in cell culture. A purer population of midbrain DA neurons may lay the foundation for successfully modeling PD and improving hit rates in drug screening approaches.
  • The milestones for the first year of the project were to establish PD-specific iPSC lines that contain genomic “docking” sites, termed “attP” sites. In year 2, these iPSC/attP cell lines will be used to insert midbrain-specific transcription factors with high efficiency, mediated by enzymes called integrases. We previously established an improved, high-efficiency, site-specific DNA integration technology in mice. This technology combines the integrase system with newly identified, actively expressed locations in the genome and ensures efficient, uniform gene expression.
  • The PD patient-specific iPSC lines we used were PI-1754, which contains a severe mutation in the SNCA (synuclein alpha) gene, and an unaffected sibling line, PI-1761. The SNCA mutation causes dramatic clinical symptoms of PD, with early-onset progressive disease. We use a homologous recombination-based procedure to place the “docking” site, attP, at well-expressed locations in the SNCA and control iPSC lines (Aim 1.1). We also included a human embryonic stem cell line, H9, to monitor our experimental procedures. The genomic locations we chose for placement of the attP sites included a site on chromosome 22 (Chr22) and a second, backup site on chromosome 19 (Chr19). These two sites were chosen based on mouse studies, in which mouse equivalents of both locations conferred strong gene expression. In order to perform recombination, we constructed targeting vectors, each containing an attP cassette flanked by 5’ and 3’ homologous fragments corresponding to the human genomic location we want to target. For the Chr22 locus, we were able to obtain all 3 targeting constructs for the PI-1754, PI-1761 and H9 cell lines. For technical reasons, we were not able to obtain constructs for the Chr19 location Thus, we decided to focus on the Chr22 locus and move to the next step.
  • We introduced the targeting vectors into the cells and selected for positive clones by both drug selection and green fluorescent protein expression. For the H9 cells, we obtained 110 double positive clones and analyzed 98 of them. We found 8 clones that had targeted the attP site precisely to the Chr22 locus. For the PI-1761 sibling control line, we obtained 44 clones, and 1 of them had the attP site inserted at the Chr22 locus. The PI-1754 SNCA mutant line, on the other hand, grows slowly in cell culture. We are in the process of obtaining enough cells to perform the recombination experiment in that cell line.
  • In summary, we demonstrated that the experimental strategy proposed in the grant indeed worked. We were successful in obtaining iPSC lines with a “docking” site placed in a pre-selected human genomic location. These cell lines are the necessary materials that set the stage for us to fulfill the milestones of year 2.
  • Parkinson's disease (PD) is caused by the loss of dopaminergic (DA) neurons in the midbrain. These DA neurons are the main source of dopamine, an important chemical in the central nervous system. PD is a common neurological disorder, affecting 1% of those at 60 years old and 4% of those over 80. Unfortunately, there is no cure for PD, nor are there any long-term therapeutics without harmful side effects. Therefore, there is a need for new therapies to halt or reverse the disease. The goal of this study is to develop a new technology that helps us obtain a purer, more abundant population of DA neurons in a culture dish and to characterize the resulting cells. These cells will be useful for studying the disease, screening potential drugs, and developing cell therapies.
  • Due to recent discoveries, we can introduce specific genes into adult human skin cells and generate cells similar to embryonic stem cells, termed induced pluripotent stem cells (iPSC). These iPSC, when derived from PD patients, can be used as an experimental model to study disease mechanisms that are unique to PD, because when differentiated into DA neurons, these cells are actually pathologically affected with PD. We are using a PD iPSC line called PI-1754 derived from a patient with a severe mutation in the SNCA gene, which encodes alpha-synuclein. The SNCA mutation causes dramatic clinical symptoms of PD, with early-onset progressive disease. For comparison we are using a normal, unaffected sibling iPSC line PI-1761. We are also using a normal human embryonic stem cell (ESC) line H9 as the gold standard for differentiation.
  • The current methods for differentiating iPSC into DA neurons are not adequate in terms of efficiency and reliability. Our hypothesis is that forced expression of certain midbrain-specific genes called transcription factors will direct iPSC to differentiate more effectively into DA neurons in cell culture. We use transcription factors called Lmx1a, Otx2, and FoxA2, abbreviated L, O, and F. In this project, we have developed a new, efficient gene integration technology that allows us rapidly to introduce and express these transcription factor genes in various combinations, in order to test whether they stimulate the differentiation of iPSC into DA neurons.
  • In the first year of the project, we began establishing iPSC and ESC lines that contained a genomic “landing pad” site for insertion of the transcription factor genes. We carefully chose a location for placement of the genes based on previous work in mouse that suggested that a site on human chromosome 22 would provide strong and constant gene expression. We initially used ordinary homologous recombination to place the landing pad into this site. By the end of year 1 of the project, this method was successful in the normal iPSC and in the ESC, but not in the more difficult-to-grow PD iPSC. To solve this problem, in year 2 we introduced a new and more powerful recombination technology, called TALENs, and were successful in placing the landing pad in the correct position in all three of the lines, including the PD iPSC.
  • We were now in a position to insert the midbrain-specific transcription factor genes with high efficiency. For this step, we developed a new genome engineering methodology called DICE, for dual integrase cassette exchange. In this technology, we use two site-specific integrase enzymes, called phiC31 and Bxb1, to catalyze precise placement of the transcription factor genes into the desired place in the genome.
  • We constructed gene cassettes carrying all pair-wise combinations of the L, O, and F transcription factors, LO, LF, and OF, and the triple combination, LOF. We successfully demonstrated the power of this technology by rapidly generating a large set of iPSC and ESC that contained all the above combinations of transcription factors, as well as lines that contained no transcription factors, as negative controls for comparison. Two examples of each type of line for the 1754 and 1761 iPSC and the H9 ESC were chosen for differentiation and functional characterization studies. Initial results from these studies have demonstrated correct differentiation of neural stem cells and expression of the introduced transcription factor genes.
  • In summary, we were successful in obtaining ESC and iPSC lines from normal and PD patient cells that carry a landing pad in a pre-selected genomic location chosen and validated for strong gene expression. These lines are valuable reagents. We then modified these lines to add DA-associated transcription factors in four combinations. All these lines are currently undergoing differentiation studies in accordance with the year two and three timelines. During year three of the project, the correlation between expression of various transcription factors and the level of DA differentiation will be established. Furthermore, functional studies with the PD versus normal lines will be carried out.
  • The objective of this project is to develop approaches and technologies that will improve neuronal differentiation of stem cells into midbrain dopaminergic (DA) neurons. DA neurons are of central importance in the project, because they are that cells that are impaired in patients with Parkinson’s disease (PD). Current differentiation methods typically produce low yields of DA neurons. The methods also give variable results, and cell populations contain many types of cells. These impediments have hampered the study of disease mechanisms for PD, as well as other uses for the cells, such as drug screening and cell replacement therapy. Our strategy is to develop a novel method to introduce genes into the genome at a specific place, so we can rapidly add genes that might help in the differentiation of DA neurons. The genes we would like to add are called transcription factors, which are proteins involved differentiation of stem cells into DA neurons. We have placed the genes for three transcription factors into a safe, active position on human chromosome 22 in the cell lines we are studying. These cells, called pluripotent stem cells, have the potential to differentiate into almost any type of cell. We are using embryonic stem cells in our study, as well as induced pluripotent stem cells (iPSC), which are similar, but are derived from adult cells, rather than an embryo. We are using iPSC derived from a PD patient, as well as iPSC from a normal person, for comparison. By forced expression of these neuronal transcription factors, we may achieve more efficient and reproducible generation of DA neurons. The effects of expressing different combinations of the three transcription factors called Lmx1a, FoxA2, and Otx2 on DA neuronal differentiation will be evaluated in the context of embryonic stem cells (ESC) as the gold standard, as well as in iPSC derived from a PD patient with a severe mutation in alpha-synuclein and iPSC derived from a normal control. Comparative functional assays of the resulting DA neurons will complete the analysis.
  • To date, this project has created a novel technology for modifying the genome. The strategy developed out of the one that we originally proposed, but contains several innovations that make it more powerful and useful. The new methodology, called DICE for Dual Integrase Cassette Exchange, allowed us to generate “master” or recipient cell lines for ESC, normal iPSC, and PD iPSC. These recipient cell lines contain a “landing pad” placed into a newly-identified actively-expressed location on human chromosome 22 called H11 that permits robust expression of genes placed into it. We then generated a series of cell lines by "cassette exchange" at the H11 locus. In cassette exchange, the new genes we want to add take the place of the landing pad we originally put into the cells. Cassette exchange is a good way to introduce various genes into the same place in the chromosomes. We created cell lines expressing three neuronal transcription factors suspected to be involved in DA neuronal differentiation, in all pair-wise combinations, including lines with expression of all three factors, and negative control lines with no transcription factors added. This collection of modified human pluripotent stem cell lines is now being used to study neural differentiation. The modified ESC have undergone differentiation into DA neurons and are being evaluated for the effects of the different transcription factor combinations on DA neuronal differentiation. During the final year of the project, this differentiation analysis will be completed, and we will also analyze functional properties of the differentiated DA neurons, with special emphasis on disease-related features of the cells derived from PD iPSC.
  • The objective of this project is to develop technologies and approaches that will improve differentiation of stem cells into midbrain dopaminergic (DA) neurons. DA neurons are of central importance in the project, because they are the cells that are impaired in patients with Parkinson’s disease (PD). It appears that midbrain dopaminergic neurons have an enormous energy requirement, which might help explain their vulnerability to degeneration in PD. Current differentiation methods typically produce low yields of DA neurons. The methods also give variable results, and cell populations contain many types of cells. These impediments have hampered the study of disease mechanisms for PD, as well as other uses for the cells, such as drug screening and cell replacement therapy. Our strategy is to develop a novel method to introduce genes into the genome at a specific place, so we can rapidly add genes that might help in the differentiation of DA neurons. The genes we would like to add are called transcription factors, which are proteins involved in differentiation of stem cells into DA neurons. We have placed the genes for three transcription factors into a safe, active position on human chromosome 22 in the cell lines we are studying. These cells, called pluripotent stem cells, have the ability to differentiate into almost any type of cell. We are using embryonic stem cells in our study, as well as induced pluripotent stem cells (iPSC), which are similar, but are derived from adult cells, rather than an embryo. We are using iPSC derived from a PD patient, as well as iPSC from a normal person, for comparison. By forced expression of neuronal transcription factors, we may achieve more efficient and reproducible generation of DA neurons. We want to evaluate the effects of expressing different combinations of three transcription factors called Lmx1a, FoxA2, and Otx2 on DA neuronal differentiation in the context of embryonic stem cells (ESC) as the gold standard, as well as in iPSC derived from a PD patient with a severe mutation in alpha-synuclein, and in iPSC derived from a normal person without PD. Comparative functional assays of the resulting DA neurons will complete the analysis.
  • To date, this project created a novel technology for modifying the genome. The strategy developed out of the one that we originally proposed, but contains several innovations that make it more powerful and useful. The new methodology, called DICE for Dual Integrase Cassette Exchange, allowed us to generate “master” or recipient cell lines for ESC, normal iPSC, and PD iPSC. These recipient cell lines contain a “landing pad” placed into a newly-identified actively-expressed location on human chromosome 22 called H11 that permits robust expression of genes placed into it. We then generated a series of cell lines by "cassette exchange" at the H11 locus. In cassette exchange, the new genes we want to add take the place of the landing pad we originally put into the cells. Cassette exchange is a good way to introduce various genes into the same place in the chromosomes.
  • We created cell lines expressing three neuronal transcription factors suspected to be involved in DA neuronal differentiation, in all pair-wise combinations, including lines with expression of all three factors, and negative control lines with no transcription factors added. This collection of modified human pluripotent stem cell lines is being used to study neural differentiation. The modified ESC were used to form embryoid bodies, which are spherical aggregations of stem cells similar to an embryo that are favorable for producing differentiated cells. We found that the embyroid bodies underwent a rapid process of spontaneous differentiation into DA neurons. The differentiation was stimulated in the cells that expressed inserted transcription factors, and some combinations of transcription factors were better than others in bringing about DA neuronal differentiation. We obtained the best differentiation in the lines that expressed the LMX1A and OTX2 transcription factors. In continuing studies, we will analyze functional properties of the differentiated DA neurons, with special emphasis on disease-related features of the cells derived from PD iPSC.
Funding Type: 
Early Translational II
Grant Number: 
TR2-01856
Investigator: 
Type: 
PI
Institution: 
Type: 
Co-PI
ICOC Funds Committed: 
$6 016 624
Disease Focus: 
Parkinson's Disease
Neurological Disorders
Collaborative Funder: 
Maryland
Stem Cell Use: 
Embryonic Stem Cell
oldStatus: 
Active
Public Abstract: 

Parkinson's disease (PD) is a devastating movement disorder caused by the death of dopaminergic neurons (a type of nerve cells in the central nervous system) present in the midbrain. These neurons secrete dopamine (a signaling molecule) and are a critical component of the motor circuit that ensures movements are smooth and coordinated.

All current treatments attempt to overcome the loss of these neurons by either replacing the lost dopamine, or modulating other parts of the circuit to balance this loss or attempting to halt or delay the loss of dopaminergic neurons. Cell replacement therapy (that is, transplantation of dopaminergic neurons into the brain to replace lost cells and restore function) as proposed in this application attempts to use cells as small pumps of dopamine that will be secreted locally and in a regulated way, and will therefore avoid the complications of other modes of treatment. Indeed, cell therapy using fetal tissue-derived cells have been shown to be successful in multiple transplant studies. Work in the field has been limited however, partially due to the limited availability of cells for transplantation (e.g., 6-10 fetuses of 6-10 weeks post-conception are required for a single patient).

We believe that human embryonic stem cells (hESCs) may offer a potentially unlimited source of the right kind of cell required for cell replacement therapy. Work in our laboratories and in others has allowed us to develop a process of directing hESC differentiation into dopaminergic neurons. To move forward stem cell-based therapy development it is important to develop scale-up GMP-compatible process of generating therapeutically relevant cells (dopaminergic neurons in this case).

The overall goal of this proposal is to develop a hESC-based therapeutic candidate (dopaminergic neurons) by developing enabling reagents/tools/processes that will allow us to translate our efforts into clinical use. We have used PD as a model but throughout the application have focused on generalized enabling tools. The tools, reagents and processes we will develop in this project will allow us to move towards translational therapy and establish processes that could be applied to future IND-enabling projects. In addition, the processes we will develop would be of benefit to the CIRM community.

Statement of Benefit to California: 

Parkinson’s disease affects more than a million patients United States with a large fraction being present in California. California, which is the home of the Parkinson’s Institute and several Parkinson’s related foundations and patient advocacy groups, has been at the forefront of this research and a large number of California based scientists supported by these foundations and CIRM have contributed to significant breakthroughs in this field.

In this application we and our collaborators in California aim propose to develop a hESC-based therapeutic candidate (dopaminergic neurons) that will allow us to move towards translational therapy and establish processes that could be applied to future IND-enabling projects for this currently non-curable disorder. We believe that this proposal includes the basic elements that are required for the translation of basic research to clinical research. We believe these experiments not only provide a blueprint for moving Parkinson’s disease towards the clinic for people suffering with the disorder but also a generalized blueprint for the development of stem cell therapy for multiple neurological disorders including motor neuron diseases and spinal cord injury. The tools and reagents that we develop will be made widely available to Californian researchers. We expect that the money expended on this research will benefit the Californian research community and the tools and reagents we develop will help accelerate the research of our colleagues in both California and worldwide.

Progress Report: 
  • Parkinson's disease (PD) is a devastating movement disorder caused by the death of dopaminergic neurons (a type of nerve cells in the central nervous system) present in the midbrain. These neurons secrete dopamine (a signaling molecule) and are a critical component of the motor circuit that ensures movements are smooth and coordinated.
  • All current treatments attempt to overcome the loss of these neurons by either replacing the lost dopamine, or modulating other parts of the circuit to balance this loss or attempting to halt or delay the loss of dopaminergic neurons. Cell replacement therapy (that is, transplantation of dopaminergic neurons into the brain to replace lost cells and restore function) as proposed in this application attempts to use cells as small pumps of dopamine that will be secreted locally and in a regulated way, and will therefore avoid the complications of other modes of treatment. Indeed, cell therapy using fetal tissue-derived cells have been shown to be successful in multiple transplant studies. Work in the field has been limited however, partially due to the limited availability of cells for transplantation (e.g., 6-10 fetuses of 6-10 weeks post-conception are required for a single patient).
  • We believe that human embryonic stem cells (hESCs) may offer a potentially unlimited source of the right kind of cell required for cell replacement therapy. Work in our laboratories and in others has allowed us to develop a process of directing hESC differentiation into dopaminergic neurons. To move forward stem cell-based therapy development it is important to develop scale-up GMP-compatible process of generating therapeutically relevant cells (dopaminergic neurons in this case).
  • The overall goal of this proposal is to develop a hESC-based therapeutic candidate (dopaminergic neurons) by developing enabling reagents/tools/processes that will allow us to translate our efforts into clinical use. We have used PD as a model but throughout the application have focused on generalized enabling tools. The tools, reagents and processes we will develop in this project will allow us to move towards translational therapy and establish processes that could be applied to future IND-enabling projects. In addition, the processes we will develop would be of benefit to the CIRM community.
  • Parkinson's disease (PD) is a devastating movement disorder caused by the death of dopaminergic neurons (a type of nerve cells in the central nervous system) present in the midbrain. These neurons secrete dopamine (a signaling molecule) and are a critical component of the motor circuit that ensures movements are smooth and coordinated.
  • All current treatments attempt to overcome the loss of these neurons by either replacing the lost dopamine, or modulating other parts of the circuit to balance this loss or attempting to halt or delay the loss of dopaminergic neurons. Cell replacement therapy (that is, transplantation of dopaminergic neurons into the brain to replace lost cells and restore function) as proposed in this application attempts to use cells as small pumps of dopamine that will be secreted locally and in a regulated way, and will therefore avoid the complications of other modes of treatment. Indeed, cell therapy using fetal tissue-derived cells have been shown to be successful in multiple transplant studies. Work in the field has been limited however, partially due to the limited availability of cells for transplantation (e.g., 6-10 fetuses of 6-10 weeks post-conception are required for a single patient).
  • We believe that human pluripotent stem cells (PSC) may offer a potentially unlimited source of the right kind of cell required for cell replacement therapy. Work in our laboratories and in others has allowed us to develop a process of directing PSC differentiation into dopaminergic neurons. To move forward stem cell-based therapy development it is important to develop scale-up GMP-compatible process of generating therapeutically relevant cells (dopaminergic neurons in this case).
  • During this grant, we have optimized a step-wise scalable process for generating authentic dopaminergic neurons in defined media from human PSC, and have determined the time point at which dopaminergic neurons can be frozen, shipped, thawed and transplanted without compromising their ability to mature and provide therapeutic benefit in animal models. Our process has been successfully transferred to a GMP facility and we have manufactured multiple lots of GMP-equivalent cells using this process. Importantly, we have shown functional equivalency of the manufactured cells in appropriate models. The tools, reagents and processes we have developed in this project allow us to move towards translational therapy and establish processes that could be applied to future IND-enabling projects. In addition, the processes we have developed would be of benefit to the CIRM community.
  • CIRM Progress Report Part A: Scientific Progress
  • I. Project Overview
  • During the past three years (36 months) we have successfully completed the milestones defined in the NGA for this grant. In brief, we have selected 1 clinically compliant ESC line H14 (and a back-up line H9), which have shown reproducible, efficient differentiation to dopaminergic neurons at lab scale. We have performed in vitro and in vivo characterization as defined in the NGA and guided by our discussion with our program officer at CIRM. We have determined the time point at which dopaminergic precursors (14 days after the NSC stage) can be frozen, shipped, thawed and transplanted without compromising their ability to mature and provide therapeutic benefit in animal models. Importantly, we have evaluated efficacy of cryopreserved dopaminergic precursors manufactured by the GMP-compatible process in a rodent PD model and shown functional recovery up to 6 months post transplantation as well as survival of dopaminergic neurons.
  • In the meanwhile we have successfully transferred the process of generating transplant ready dopaminergic neurons to the manufacture facilities at City of Hope (COH). They have adapted and optimized our protocols and have established GMP-compatible protocols for the culture of ESC-NSC and for differentiating NSC to Stage 3, Day 14 DA precursors for transplantation. During this reporting period (36 month), we have tested the equivalency of these lots and confirmed that lots manufactured at COH are consistent and similar to cells produced in the laboratory.
  • Our effort resulted in two important manuscripts in Cytotherapy:
  • 1. Liu, Q., Pedersen, OZ., Peng, J., Couture, LA., Rao, MS., and Zeng, X. Optimizing dopaminergic differentiation of pluripotent stem cells for the manufacture of dopaminergic neurons for transplantation. Cytotherapy. 2013 Aug;15(8):999-1010.
  • 2. Peng, J., Liu, Q., Rao, MS., and Zeng, X. Survival and engraftment of dopaminergic neurons manufactured by a GMP-compatible process. Cytotherapy. 2014 Sep;16(9):1305-12.
Funding Type: 
Early Translational II
Grant Number: 
TR2-01844
Investigator: 
Name: 
Institution: 
Type: 
PI
ICOC Funds Committed: 
$5 665 887
Disease Focus: 
Spinal Muscular Atrophy
Neurological Disorders
Pediatrics
Stem Cell Use: 
iPS Cell
oldStatus: 
Closed
Public Abstract: 

Spinal muscular atrophy (SMA) is the leading genetic cause of infant death in the U.S. This devastating disease affects 1 child in every 6,000-10,000 live births, with a North American prevalence of approximately 14,000 individuals. The disease is characterized by the death of spinal cord cells called motor neurons that connect the brain to muscle. Death of these cells causes muscle weakness and atrophy, which progresses to paralysis, respiratory failure and frequently death. The three different types of SMA differ in severity and prognosis, with Type I being the most severe. SMA is caused by a genetic defect that leads to reduced levels of a single protein called SMN.

There are currently no approved therapies for the disease. The existing treatments for SMA consist of supportive care for the respiratory and nutritional deficits, for example ventilation and feeding tubes. Previous attempts to develop drugs using conventional technologies, such as cultured cancer cells or cells derived from animals have been unsuccessful. These failures are likely due the fact that previous attempts used cell types that don’t reflect the disease or aren’t affected by low levels of the SMN protein.

Our approach uses patient-derived motor neurons, the specific cell type that dies. We will conduct drug discovery experiments using these motor neurons to find potential therapeutics that increase the levels of the SMN protein in these diseased cells. Induced pluripotent stem cell (iPSC) technology allows us to take skin cells from patients with SMA, grow them in a dish, and turn them into motor neurons. We are conducting high-throughput screens of potential drugs with these cells to identify drug candidates that increase SMN protein levels in motor neurons derived from SMA patients. An added advantage to our approach is that we can test our drug candidates in motor neurons from many different patients, with different disease subtypes and from different ethnic backgrounds. We have generated iPSCs from many patients with SMA and we will test compounds for effectiveness against this cohort. These studies will give us an indication of the effectiveness of our compounds across patients before moving into costly and lengthy clinical trials.

If our drug candidate is successful, it could be the first effective therapeutic available for SMA. It will increase the amount of SMN protein and prevent motor neuron death. Halting the death of spinal cord motor neurons prevents the progressive weakness and muscle atrophy. We anticipate that this would prevent disability in Type III patients. For Type I and II patients, we believe such a therapy would mitigate respiratory and feeding challenges and allow lifespan increase.

The sponsoring institution has integrated iPSC-based drug discovery capabilities, ranging from stem cell line production, high throughput drug screening and medicinal chemistry. Accordingly, this institution is uniquely positioned to achieve the aims of this grant.

Statement of Benefit to California: 

Spinal muscular atrophy (SMA) is the second-most common autosomal-recessive disorder and leading genetic cause of death of infants in the U.S. We estimate that there are up to 1,500 SMA patients currently living in California, with 100 new cases diagnosed in California every year. The CIRM Early Translational II Awards is intended to fund studies that will propel drug discovery forward for many devastating diseases. In keeping with this mission, we propose to leverage iPSC technology to generate disease-relevant cell types from patients themselves for a high throughput drug screen. A successful therapy for SMA would lead to significant cost savings to California’s health care system, and would provide relief to families of patients with this devastating disorder.

Given that there are not many successful drugs in the making for neurological diseases such as ALS, SMA, Parkinson’s disease or Alzheimer’s disease, our project should significantly impact drug discovery in this area by introducing iPSC technologies as a valid drug discovery and development platform. The application of iPSC-based disease modeling and drug discovery to SMA is highly innovative and represents the opportunity to establish worldwide leadership for California in this emerging field.

Furthermore, the sponsoring institution will fund over 70% of the direct costs during the timeframe of this award. Accordingly, the 3:1 leverage provides great opportunity to magnify the effect of a CIRM award. Our research program will also create new, high-paying jobs in California, and will stimulate California’s economy by creating new research and clinical tools. These activities will continue to strengthen California’s leadership position at the forefront of the stem cell and regenerative medical revolution of the 21st century.

Progress Report: 
  • Spinal muscular atrophy (SMA) is the leading genetic cause of infant death in the U.S. This devastating disease affects 1 child in every 6,000-10,000 live births, with a North American prevalence of approximately 14,000 individuals. The disease is characterized by the death of spinal cord cells called motor neurons that connect the brain to muscle. Death of these cells causes muscle weakness and atrophy, which progresses to paralysis, respiratory failure and frequently death. The three different types of SMA differ in severity and prognosis, with Type I being the most severe. SMA is caused by a genetic defect that leads to reduced levels of a single protein called SMN. There are currently no approved therapies for the disease.
  • Existing treatments for SMA consist of supportive care for the respiratory and nutritional deficits, for example ventilation and feeding tubes. Previous attempts to develop drugs using conventional technologies, such as cultured cancer cells or cells derived from animals have been unsuccessful. These failures are likely due to the fact that previous attempts used cell types that do not reflect the disease or are not affected by low levels of the SMN protein. Our approach uses patient-derived motor neurons, the specific cell type that dies in SMA.
  • An added advantage to our approach is that we can test our drug candidates in motor neurons from many different patients and different disease subtypes. We have generated iPSCs from many patients with SMA and we will test compounds for effectiveness against this cohort. These studies will give us an indication of the effectiveness of our compounds across patients before moving into costly and lengthy clinical trials. It will increase the amount of SMN protein and prevent motor neuron death. Halting the death of spinal cord motor neurons prevents the progressive weakness and muscle atrophy. We anticipate that this would prevent disability in Type III patients. For Type I and II patients, we believe such a therapy would mitigate respiratory and feeding challenges and allow an increase in lifespan.
  • In the past year, we conducted drug discovery experiments using these motor neurons to find potential therapeutics that increase the levels of the SMN protein in these diseased cells. Induced pluripotent stem cell (iPSC) technology allows us to take skin cells from patients with SMA, grow them in a dish, and turn them into SMA motor neurons. We conducted high-throughput screens of potential drugs with these cells to identify drug candidates that increase SMN protein levels in motor neurons derived from SMA patients. Despite the high quality of these screens, no suitable drug candidate was identified. We have modified our strategy and developed a method to identify, in parallel, all targets in the “druggable” genome that regulate SMN protein levels. An exhaustive screen currently is being performed to identify such a target and will be completed by end April 2012. Once a target is identified, it will be developed into a lead and validated in animals.
Funding Type: 
Early Translational II
Grant Number: 
TR2-01841
Investigator: 
Type: 
PI
ICOC Funds Committed: 
$4 045 253
Disease Focus: 
Huntington's Disease
Neurological Disorders
Stem Cell Use: 
Embryonic Stem Cell
Cell Line Generation: 
Embryonic Stem Cell
oldStatus: 
Active
Public Abstract: 

Huntington’s disease (HD) is a devastating degenerative brain disease with a 1 in 10,000 prevalence that inevitably leads to death. These numbers do not fully reflect the large societal and familial cost of HD, which requires extensive caregiving. HD has no effective treatment or cure and symptoms unstoppably progress for 15-20 years, with onset typically striking in midlife. Because HD is genetically dominant, the disease has a 50% chance of being inherited by the children of patients. Symptoms of the disease include uncontrolled movements, difficulties in carrying out daily tasks or continuing employment, and severe psychiatric manifestations including depression. Current treatments only address some symptoms and do not change the course of the disease, therefore a completely unmet medical need exists. Human embryonic stem cells (hESCs) offer a possible long-term treatment approach that could relieve the tremendous suffering experienced by patients and their families. HD is the 3rd most prevalent neurodegenerative disease, but because it is entirely genetic and the mutation known, a diagnosis can be made with certainty and clinical applications of hESCs may provide insights into treating brain diseases that are not caused by a single, known mutation. Trials in mice where protective factors were directly delivered to the brains of HD mice have been effective, suggesting that delivery of these factors by hESCs may help patients. Transplantation of fetal brain tissue in HD patients suggests that replacing neurons that are lost may also be effective. The ability to differentiate hESCs into neuronal populations offers a powerful and sustainable alternative for cell replacement. Further, hESCs offer an opportunity to create cell models in which to identify earlier markers of disease onset and progression and for drug development.

We have assembled a multidisciplinary team of investigators and consultants who will integrate basic and translational research with the goal of generating a lead developmental candidate having disease modifying activity with sufficient promise to initiate IND-enabling activities for HD clinical trials. The collaborative research team is comprised of investigators from multiple California institutions and has been assembled to maximize leverage of existing resources and expertise within the HD and stem cell fields.

Statement of Benefit to California: 

The disability and loss of earning power and personal freedom resulting from Huntington's disease (HD) is devastating and creates a financial burden for California. Individuals are struck in the prime of life, at a point when they are their most productive and have their highest earning potential. As the disease progresses, individuals require institutional care at great financial cost. Therapies using human embryonic stem cells (hESCs) have the potential to change the lives of hundreds of individuals and their families, which brings the human cost into the thousands. For the potential of hESCs in HD to be realized, a very forward-thinking team effort will allow highly experienced investigators in HD, stem cell research and clinical trials to come together and identify a lead development candidate for treatment of HD. This early translation grant will allow for a comprehensive and systematic evaluation of hESC-derived cell lines to identify a candidate and develop a candidate line into a viable treatment option. HD is the 3rd most prevalent neurodegenerative disease, but because it is entirely genetic and the mutation known, a diagnosis can be made with certainty and clinical applications of hESCs may provide insights into treating brain diseases that are not caused by a single, known mutation.

We have assembled a strong team of California-based investigators to carry out the proposed studies. Anticipated benefits to the citizens of California include: 1) development of new human stem cell-based treatments for HD with application to other neurodegenerative diseases such as Alzheimer's and Parkinson's diseases that affect thousands of individuals in California; 2) improved methods for following the course of the disease in order to treat HD as early as possible before symptoms are manifest; 3) transfer of new technologies and intellectual property to the public realm with resulting IP revenues coming into the state with possible creation of new biotechnology spin-off companies; and 4) reductions in extensive care-giving and medical costs. It is anticipated that the return to the State in terms of revenue, health benefits for its Citizens and job creation will be significant.

Progress Report: 
  • Huntington’s disease (HD) is a devastating degenerative brain disease with a 1 in 10,000 prevalence that inevitably leads to death. Because HD is genetically dominant, the disease has a 50% chance of being inherited by the children of patients. Symptoms of the disease include uncontrolled movements, difficulties in carrying out daily tasks or continuing employment, and severe psychiatric manifestations including depression. Current treatments only address some symptoms and do not change the course of the disease, therefore a completely unmet medical need exists. Human embryonic stem cells (hESCs) offer a possible long-term treatment approach that could relieve the tremendous suffering experienced by patients and their families. Because HD is entirely genetic and the mutation known, a diagnosis can be made with certainty and clinical applications of hESCs may provide insights into treating brain diseases that are not caused by a single, known mutation. The ability to differentiate hESCs into neuronal populations offers a powerful and sustainable treatment opportunity. We have established the multidisciplinary team of investigators and consultants to integrate basic and translational research with the goal of generating a lead developmental candidate having disease modifying activity with sufficient promise to initiate IND-enabling activities for HD clinical trials.
  • In preliminary experiments, the transplantation of mouse neural stem cells, which survived in the brain for the four week period of the trial, provided protective effects in delaying disease progression in an HD mouse model and increased production of protective molecules in the brains of these mice. In the first year, the team has developed and established methods to differentiate hESCs into neural, neuronal and astrocyte precursors to be used for transplantation and has determined the correct cells to use that can be developed for future clinical development of these cells. In initial studies during this year, transplantation of neural stem cells (NSCs) provided both neurological and behavioral benefit to a HD mouse model. In addition, neuroprotective molecules were increased. Three immunosuppression regimens were tested to optimize methods for next stage preclinical trials. Finally, breeding of the three different HD mouse models has been initiated. Taken as a whole, progress supports the feasibility of the CIRM-funded studies to transplant differentiated hESCs into HD mice for preclinical development with the ultimate goal of initiating IND-enabling activities for HD clinical trials.
  • Huntington’s disease (HD) is a devastating degenerative brain disease with a 1 in 10,000 prevalence that inevitably leads to death. Because HD is genetically dominant, the disease has a 50% chance of being inherited by the children of patients. Symptoms of the disease include uncontrolled movements, difficulties in carrying out daily tasks or continuing employment, and severe psychiatric manifestations including depression. Current treatments only address some symptoms and do not change the course of the disease, therefore a completely unmet medical need exists. Human embryonic stem cells (hESCs) offer a possible long-term treatment approach that could relieve the tremendous suffering experienced by patients and their families. Because HD is entirely genetic and the mutation known, a diagnosis can be made with certainty and clinical applications of hESCs may provide insights into treating brain diseases that are not caused by a single, known mutation. The ability to differentiate hESCs into neuronal populations offers a powerful and sustainable treatment opportunity. We have established the multidisciplinary team of investigators and consultants to integrate basic and translational research with the goal of generating a lead developmental candidate having disease modifying activity with sufficient promise to initiate IND-enabling activities for HD clinical trials.
  • We previously performed transplantation of human neural stem cells into an HD mouse model and found that a subset of cells survived in the brain for the four week period of the trial, providing protective effects in delaying disease progression. In the past year, we have increased production and characterization of human neural stem cells (hNSCs) into neuronal (hNPC) and astrocyte (hAPC) precursors to be used for transplantation and optimized methods for shipping and implantation. Immunosuppression regimens were improved to optimize cell survival of implanted cells in HD mice. Transplantation of both human NSCs and NPCs are neuroprotective to HD mice and transplantation of hAPCs is in progress. Once completed, the cell giving the greatest protective benefit will be transplanted into mice that display slower progression over a longer time frame to validate and optimize approach for subsequent human application. All three HD mouse models have been bred and are ready for stem cell transplants. Taken as a whole, progress supports the feasibility of the CIRM-funded studies to transplant differentiated hESC-derived cell types into HD mice for preclinical development with the ultimate goal of identifying a lead candidate cell type and initiating IND-enabling activities for HD clinical trials.
  • Huntington’s disease (HD) is a devastating degenerative brain disease with a 1 in 10,000 prevalence that inevitably leads to death. Because HD is genetically dominant, the disease has a 50% chance of being inherited by the children of patients. Symptoms of the disease include uncontrolled movements, difficulties in carrying out daily tasks or continuing employment, and severe psychiatric manifestations including depression. Current treatments only address some symptoms and do not change the course of the disease, therefore a completely unmet medical need exists. Human embryonic stem cells (hESCs) offer a possible long-term treatment approach that could relieve the tremendous suffering experienced by patients and their families. Because HD is entirely genetic and the mutation known, a diagnosis can be made with certainty and clinical applications of hESCs may provide insights into treating brain diseases that are not caused by a single, known mutation. The ability to differentiate hESCs into neuronal populations offers a powerful and sustainable treatment opportunity. We have established the multidisciplinary team of investigators and consultants to integrate basic and translational research with the goal of generating a lead developmental candidate having disease modifying activity with sufficient promise to initiate Investigational New Drug (IND) enabling activities for HD clinical trials.
  • We have completed several rounds of transplantation of human neural stem cells into an HD mouse model and found that the cells survived in the brain for the four-week period of the trial, provided protective effects in delaying disease progression and increased production of protective molecules in the brains of these mice. In the last year the team differentiated hESCs into neural, neuronal and astrocyte precursors and performed transplantation studies to determine the best cell candidate to use and develop for future clinical work. We determined that the human neural stem cells produce the most robust effect. We have now selected a GMP grade hNSC line that will be carried forward for further testing in both rapidly progressing and slower progressing HD mice, as well as in mouse preclinical dosing studies. Taken as a whole, progress supports the feasibility of the CIRM-funded studies to transplant differentiated hESCs into HD mice for preclinical development with the ultimate goal on initiating IND-enabling activities for HD clinical trials.
  • Huntington’s disease (HD) is a devastating degenerative brain disease with a 1 in 10,000 prevalence that inevitably leads to death. These numbers do not fully reflect the large societal and familial cost of HD, which requires extensive care-giving. HD has no effective treatment or cure and symptoms unstoppably progress for 15-20 years, with onset typically striking in midlife. Because HD is genetically dominant, the disease has a 50% chance of being inherited by the children of patients. Symptoms of the disease include uncontrolled movements, difficulties in carrying out daily tasks or continuing employment, and severe psychiatric manifestations including depression. Current treatments only address some symptoms and do not change the course of the disease, therefore a completely unmet medical need exists. Human embryonic stem cells (hESCs) offer a possible long-term treatment approach that could relieve the tremendous suffering experienced by patients and their families. HD is the 3rd most prevalent neurodegenerative disease, but because it is entirely genetic and the mutation known, a diagnosis can be made with certainty and clinical applications of hESCs may provide insights into treating brain diseases that are not caused by a single, known mutation. Trials in mice where protective factors were directly delivered to the brains of HD mice have been effective, suggesting that delivery of these factors by hESCs may help patients. Transplantation of fetal brain tissue in HD patients suggests that replacing neurons that are lost may also be effective. The ability to differentiate hESCs into neuronal populations offers a powerful and sustainable alternative for cell replacement. Further, hESCs offer an opportunity to create cell models in which to identify earlier markers of disease onset and progression and for drug development. We assembled a multidisciplinary team of investigators and consultants who integrated basic and translational research and have now generated a lead developmental candidate neural stem cell having disease modifying activity with sufficient promise to initiate Investigative New Drug-enabling (IND) activities for HD clinical trials. We are now ready to utilize the collaborative research team, additional clinical investigators and FDA consultants to finalize work that will lead to an IND meeting with the FDA and a path forward for clinical trials with the neural stem cell developmental candidate.
Funding Type: 
Early Translational II
Grant Number: 
TR2-01832
Investigator: 
Institution: 
Type: 
PI
Institution: 
Type: 
Partner-PI
ICOC Funds Committed: 
$1 835 983
Disease Focus: 
Genetic Disorder
Neurological Disorders
Pediatrics
Collaborative Funder: 
Germany
Stem Cell Use: 
iPS Cell
Cell Line Generation: 
iPS Cell
oldStatus: 
Active
Public Abstract: 

Canavan disease is a devastating disease of infants which affects their neural development and leads to mental retardation and early death. It occurs in 1 in 6,400 persons in the U.S. and there is no treatment so far. We propose to generate genetically-repaired and patient-specific stem cells (called iPSCs) from patients’ skin cells, and then coax these stem cells into specific types of corrective neural precursors using methods established in our laboratories in order to develop a therapeutic candidate for this disease. By use of a mouse model of Canavan disease, we will determine the ability of these genetically corrected cells to successfully treat the disease. These results will form the basis for an eventual clinical trial in humans, and if successful, would be the first treatment for this terrible disease.

There are many families affected by this disease, and other diseases similar to it. Results from this work could have applications to this and other similar genetic diseases. Through the proposed research, maybe no parents will have to watch their child suffer and die as a result of these dreadful diseases in one day. What a wonderful day that would be!

Statement of Benefit to California: 

It is estimated that California has ~12% of all cases of Canavan disease in the U.S. Besides the tremendous emotional and physical pain that this disease inflicts on families, it produces in California a medical and fiscal burden that is larger than any other states. Thus, there is a real need to develop a strategy of treatment for this disease. Stem cells provide great hope for the treatment of a variety of human diseases that affect the citizens of California. Combination of gene therapy and iPSC technology will enable the development of therapeutic candidates of human genetic diseases via the creation of genetically-corrected patient-specific iPSCs. Our proposal aims to establish a therapeutic development candidate for Canavan disease, a devastating neurodegenerative disease that leads to mental retardation and early death. The generation of genetically-repaired and patient-specific iPSC lines will represent great potential not only for California health care patients but also for pharmaceutical and biotechnology industries in California. Moreover, California is a strong leader in pre-clinical and clinical research developments. To maintain this position, we need to create patient-specific stem cells as autologous therapeutic candidates, in order to overcome the challenges of immune rejection faced by today’s cell therapy field. This proposal addresses the very issue by generating “disease-corrected” and patient-specific iPSCs as a therapeutic candidate with the potential to create safer and more effective cell replacement therapies.

Progress Report: 
  • Canavan disease is a devastating disease of infants which affects their neural development and leads to mental retardation and early death. It occurs in 1 in 6,400 persons in the U.S. and there is no treatment so far. We propose to generate genetically-repaired and patient-specific stem cells (called iPSCs) from patients’ skin cells, and then coax these stem cells into specific types of corrective neural precursors using methods established in our laboratories in order to develop a therapeutic candidate for this disease.
  • For the reporting period, we have obtained primary dermal fibroblasts from clinically affected Canavan disease patients and have derived Canavan disease patient iPSCs. We have demonstrated that these iPSCs exhibited typical human embryonic stem cell (ESC) like morphology, expressed human ESC cell surface markers and hold pluripotency potential. We are also optimizing methods to coax these cells into specific types of neural precursors. Either the patient iPSCs or their neural precursor derivatives will be genetically corrected in the following years to develop a therapeutic tool for Canavan disease patients.
  • There are many families affected by this disease, and other diseases similar to it. Results from this work could have applications to this and other similar genetic diseases. Through the proposed research, maybe no parents will have to watch their child suffer and die as a result of these dreadful diseases in one day.
  • Canavan disease is a devastating disease of infants which affects their neural development and leads to mental retardation and early death. It occurs in 1 in 6,400 persons in the U.S. and there is no treatment so far. We propose to generate genetically-repaired and patient-specific stem cells (called iPSCs) from patients’ skin cells, and then coax these stem cells into specific types of corrective neural precursors using methods established in our laboratories in order to develop a therapeutic candidate for this disease.
  • For the reporting period, we have demonstrated that the Canavan disease patient iPSCs hold pluripotency potential. We also genetically corrected the patient iPSCs and demonstrated that these genetically-corrected cells maintained human embryonic stem cell-like features. We coaxed these cells into specific types of neural precursors and showed that the genetically-corrected patient cells restored their cellular function. These genetically corrected cells will be tested for their therapeutic effect in the next year, in order to develop a therapeutic tool for Canavan disease patients.
  • There are many families affected by this disease, and other diseases similar to it. Results from this work could have applications to this and other similar genetic diseases. Through the proposed research, maybe no parents will have to watch their child suffer and die as a result of these dreadful diseases in one day.
  • Canavan disease is a devastating disease of infants which affects their neural development and leads to mental retardation and early death. It occurs in 1 in 6,400 persons in the U.S. and there is no treatment so far. We propose to generate genetically-repaired and patient-specific stem cells (called iPSCs) from patients’ skin cells, and then coax these stem cells into specific types of corrective neural precursors using methods established in our laboratories in order to develop a therapeutic candidate for this disease.
  • We have demonstrated that the Canavan disease patient iPSCs hold pluripotency potential. We also genetically corrected the patient iPSCs and demonstrated that these genetically-corrected cells maintained human embryonic stem cell-like features. We coaxed these cells into specific types of neural precursors and showed that the genetically-corrected patient cells restored their cellular function.
  • For the reporting period, we provided evidence that the genetically-corrected patient iPSC-derived neural precursors were able to produce myelin binding protein in an animal model. We also characterized the Canavan disease mice to show that they exhibited the characteristic Canavan disease patient phenotypes. The genetically corrected cells will be tested in Canavan disease mice for their therapeutic effect in the next funding period, in order to develop a therapeutic tool for Canavan disease patients.
  • There are many families affected by this disease, and other diseases similar to it. Results from this work could have applications to this and other similar genetic diseases. Through the proposed research, maybe no parents will have to watch their child suffer and die as a result of these dreadful diseases in one day.
  • Canavan disease is a devastating disease of infants which affects their neural development and leads to mental retardation and early death. It occurs in 1 in 6,400 persons in the U.S. and there is no treatment so far. We propose to generate genetically-repaired and patient-specific stem cells (called iPSCs) from patients’ skin cells, and then coax these stem cells into specific types of corrective neural precursors using methods established in our laboratories in order to develop a therapeutic candidate for this disease.
  • We have demonstrated that the Canavan disease patient iPSCs hold pluripotency potential. We also genetically corrected the patient iPSCs and demonstrated that these genetically-corrected cells maintained human embryonic stem cell-like features. We coaxed these cells into specific types of neural precursors and showed that the genetically-corrected patient cells restored their cellular function.
  • For the reporting period, we characterized the Canavan disease mice to show that they exhibited the characteristic Canavan disease patient phenotypes. We then tested the genetically corrected cells in the Canavan disease mice for their therapeutic effect. We found that the genetically corrected cells were able to survive in the transplanted brains and express the correct lineage marker. Moreover, these cells were able to rescue the major phenotypes that are characteristic of Canavan disease patients in the transplanted mice. Our results convincingly demonstrated that the genetically corrected patient iPSC-derived cells have the potential to serve as a therapeutic tool for Canavan disease patients.
  • There are many families affected by this disease, and other diseases similar to it. Results from this work could have applications to this and other similar genetic diseases. Through the proposed research, maybe no parents will have to watch their child suffer and die as a result of these dreadful diseases in one day.
Funding Type: 
Early Translational II
Grant Number: 
TR2-01814
Investigator: 
ICOC Funds Committed: 
$1 491 471
Disease Focus: 
Autism
Neurological Disorders
Pediatrics
Stem Cell Use: 
iPS Cell
Cell Line Generation: 
iPS Cell
oldStatus: 
Active
Public Abstract: 

Autism and autism spectrum disorders (ASD) are complex neurodevelopmental diseases that affect 1 in 150 children in the United States. Such diseases are mainly characterized by deficits in verbal communication, impaired social interaction, and limited and repetitive interests and behavior. Because autism is a complex spectrum of disorders, a different combination of genetic mutations is likely to play a role in each individual. One of the major impediments to ASD research is the lack of relevant human disease models. ASD animal models are limited and cannot reproduce the important language and social behavior impairment of ASD patients. Moreover, mouse models do not represent the vast human genetic variation. Reprogramming of somatic cells to a pluripotent state (induced pluripotent stem cells, iPSCs) has been accomplished using human cells. Isogenic pluripotent cells are attractive from the prospective to understanding complex diseases, such as ASD. Our preliminary data provide evidence for an unexplored developmental window in ASD wherein potential therapies could be successfully employed. The model recapitulates early stages of ASD and represents a promising cellular tool for drug screening, diagnosis and personalized treatment. By testing whether drugs have differential effects in iPSC-derived neurons from different ASD backgrounds, we can begin to unravel how genetic variation in ASD dictates responses to different drugs or modulation of different pathways. If we succeed, we may find new molecular mechanisms in ASD and new compounds that may interfere and rescue these pathways. The impact of this approach is significant, since it will help better design and anticipate results for translational medicine. Moreover, the collection and molecular/cellular characterization of these iPSCs will be an extremely valuable tool to understand the fundamental mechanism behind ASD. The current proposal uses human somatic cells converted into iPSC-derived neurons. The proposed experiments bring our analyses to real human cell models for the first time. We anticipate gaining insights into the causal molecular mechanisms of ASD and to discover potential biomarkers and specific therapeutic targets for ASD.

Statement of Benefit to California: 

Autism spectrum disorders, including Rett syndrome, Angelman syndrome, Timothy syndrome, Fragile X syndrome, Tuberous sclerosis, Asperger syndrome or childhood disintegrative disorder, affect many Californian children. In the absence of a functionally effective cure or early diagnostic tool, the cost of caring for patients with such pediatric diseases is high, in addition to a major personal and family impact since childhood. The strikingly high prevalence of ASD, dramatically increasing over the past years, has led to the emotional view that ASD can be traced to a single source, such as vaccine, preservatives or other environmental factors. Such perspective has a negative impact on science and society in general. Our major goal is to develop a drug-screening platform to rescue deficiencies showed from neurons derived from induced pluripotent stem cells generated from patients with ASD. If successful, our model will bring novel insights on the dentification of potential diagnostics for early detection of ASD risk, or ability to predict severity of particular symptoms. In addition, the development of this type of pharmacological therapeutic approach in California will serve as an important proof of principle and stimulate the formation of businesses that seek to develop these types of therapies (providing banks of inducible pluripotent stem cells) in California with consequent economic benefit.

Progress Report: 
  • During the first year of the project, we focused on creating a cell bank of reprogrammed fibroblasts derived from several autistic patients. These pluripotent stem cells were then induced to differentiate into neurons and gene expression analyses will be done at different time points along the process. We also used some of the syndromic and non-syndromic patients for neuronal phenotypic assays and found that a subset of idiopathic autism cases displayed a molecular overlap with Rett syndrome. Our plan is to use these data to test the ability of candidate drugs on reverting some of the neuronal defects observed in patient neurons.
  • The goal of this CIRM translational award is to generate a hiPSC-based drug-screening platform to identify potential therapies or biomarkers for autism spectrum disorders. In this second year we have made significant progress toward this goal by working on validating several neuronal phenotypes derived from iPSCs from idiopathic and syndromic autistic patients. We also made significant progress in order to optimize a synaptic readout for the screening platform. This step was important to speed up drug discovery. Using Rett syndrome iPSC-derived neurons as a prototype, we showed that we could rescue defect in synaptogenesis using a collection of FDA-approved drugs. Finally, we have initiated our analyses on global gene expression, from several neurons and progenitor cells derived from controls and autistic patients. We expect to find pathways that are altered in subgroups of patients, defined by specific clinical phenotypes.
  • The goal of this CIRM translational award is to generate a hiPSC-based drug-screening platform to identify potential therapies or biomarkers for ASDs. We have made significant progress toward this goal by working on validating several neuronal phenotypes derived from iPSC from Rett syndrome (RTT) and idiopathic autistic patients. We also made significant progress to optimize the readout for our screening platform. This was important to speed up drug discovery. Using RTT iPSC as a prototype, we showed that we could rescue defect in synaptogenesis using a collection of FDA-approved drugs. Finally, we initiate our analyses on gene expression, collected from several neurons and progenitor cells derived from controls and autistic patients. We expect to find pathways that are altered in subgroups of patients, defined by specific clinical phenotypes. Here, we describe the results of our drug screening, using FDA-approved drugs in a repurposing strategy. We also show for the first time that iPSC-derived human neurons are able to generate synchronized neuronal networks. RTT neurons behave differently from controls. Our focus now is on the completion of our gene expression analyses and to validate positive drugs using a battery of secondary cellular assays.
  • The goal of this CIRM translational award is to generate a hiPSC-based drug-screening platform to identify potential therapies or biomarkers for ASDs. We have made significant progress toward this goal by working on validating several neuronal phenotypes derived from iPSC from Rett syndrome (RTT) and idiopathic autistic patients. We also made significant progress to optimize the synaptogenesis readout for our screening platform. This was important to speed up drug discovery. Using RTT iPSC as a prototype, we showed that we could rescue defect in synaptogenesis using a collection of FDA-approved drugs. We also show for the first time that iPSC-derived human neurons are able to generate synchronized neuronal networks using a multi-electrode array approach. We showed that RTT and ASD neurons behave differently from controls and defects in synchronization can be rescued with candidate drugs. Finally, we concluded our analyses on gene expression, collected from several neurons and progenitor cells derived from controls and autistic patients. We revealed and validated pathways that are altered in ASD patients, defined by specific clinical phenotypes (macrencephaly).

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