Neurological Disorders

Coding Dimension ID: 
303
Coding Dimension path name: 
Neurological Disorders

The HD iPSC Consortium: Repeat Length Dependent Phenotypes for Assay Development

Funding Type: 
iPSC Consortia Award
Grant Number: 
RP1-05741
ICOC Funds Committed: 
$300 000
Disease Focus: 
Huntington's Disease
Neurological Disorders
Stem Cell Use: 
iPS Cell
Cell Line Generation: 
iPS Cell
oldStatus: 
Active
Public Abstract: 
Statement of Benefit to California: 
Progress Report: 
  • Huntington’s disease (HD) is a significant neurodegenerative disease with unique genetic features. A CAG expansion in Huntington gene is correlated with severity and onset of sub-clinical and overt clinical symptoms, make it particularly suited to therapeutic development . The single genetic cause offers the opportunity to understand the pathological process triggered in all individuals with a CAG expansion, as emerging evidence suggests effects of the mutation in all cell types, though striatal neurons are most vulnerable to degeneration. Moreover, by virtue of a molecular test for the mutation, a unique opportunity exists to intervene/treat before the onset of overt clinical symptoms utilizing sub-clinical phenotypes emerging in pre-manifest individuals. Since human induced pluripotent stem cells (iPSCs) have the power to make any cell type in the human body, we are utilizing the technology to make patients iPSCs and study the effects of different number of CAG repeats on the neurons we generate from the patient iPS cells. Preliminary studies indicate that CAG length–dependent phenotypes occur at all stages of differentiation, from iPSC through to mature neurons and are likely to occur in non-neuronal cells as well, which can also be investigated using the iPSC that we are creating. The non-integrating technology (avoids integration of potentially deleterious reprogramming factors in the cell DNA) for producing iPSC lines is crucial to obtaining reproducible disease traits from patient cells.
  • The Cedars-Sinai RMI iPSC Core is part of the Huntington’s Disease (HD) consortium. In the past year the iPSC Core has made many new non-integrating induced pluripotent stem (iPSC) cell lines from HD patients with different numbers of CAG repeat expansions. The grant application proposed generation of 18 HD and Control iPSC lines. Instead we are generating 20 iPSC lines. So far we have already generated 17 iPSC lines from individuals with Huntington’s disease and controls (10 HD patients and 7 controls). In order to have the disease trait reproducible across multiple groups, three clonal iPSC lines were generated from each subject. Some of these lines have (or are in process) of expansion for distribution to consortium members. We are now in the process of making the last 3 lines as part of this grant application to generate a HD iPSC repository with total of 20 patient/control lines from subjects with multitude of CAG repeat numbers. Most of these lines have undergone rigorous battery of characterization for pluripotency determination, while some other lines are currently being validated through more characterization tests. Neural stem cell aggregates (EZ spheres) have been generated from few of the patient lines in the Svendsen lab (not supported by this grant). We have also submitted 6 patient iPSC lines to Coriell Cell Repository for larger banking and distribution of these important and resourceful lines to other academic investigators and industry. We strongly believe that this iPSC repository will enormously speed up the process of understanding the disease causing mechanisms in HD patient brain cells as well as discovering novel therapeutics or drugs that may one day be able to treat HD patients.
  • Huntington’s disease (HD) is a fatal neurodegenerative condition with no current treatment. This significant neurodegenerative disease, whose relatively simple and unique known genetic cause, a CAG expansion in the HD gene correlated with severity and onset of clinical symptoms, makes it particularly suited to therapeutic development. The Huntington’s disease (HD) iPS cell consortium, funded with NIH and CIRM support, brings together leading groups in stem cell and HD research to establish whether newly created iPS cell lines show HD related (i.e., CAG length-dependent) phenotypes. Human iPSC technology can be used to generate specific neuronal and glial cell types, permitting investigation of the effects of the genetic lesion in the susceptible human cell types in the context of HD. The monogenic nature of HD and the existence of allelic series of iPSCs with a range of CAG repeat lengths confer tremendous power to model HD. Through CIRM support this consortium has capitalized on new technologies to use non-integrating approaches for reprogramming and promising phenotypes in current HD iPS lines to develop robust and validated assays for drug development for HD.
  • Significant progress has been made through CIRM-funded support of this proposal. Notably, the Cedars-Sinai Medical Center’s Board of iPSC core housed in the Board of Governors Regenerative Medicine Institute has taken skin cells from HD patients with a wide range of CAG repeats (43 to 180), and unaffected healthy controls (21 to 33) and reprogrammed then to pluripotency using the latest non-integrating iPS cell technology. So far 18 well-characterized patient-specific iPSC lines have been generated. These new iPSC lines have been rigorously characterized by our iPSC core and available to HD research community throughout California and the world. The Svendsen lab and the other HD iPSC Consortium laboratories have already used these lines and differentiated into relevant neuronal cell types to study the disease mechanisms as well develop new treatment.
  • These cell lines will be an essential resource for academic groups and pharmaceutical companies for studying pathogenesis and for testing experimental therapeutics for HD. The ultimate goal is to develop and validate methods and assays using >96 well format for CAG repeat length-dependent phenotypes that are amenable to high content/throughput screening methods. Assays developed using these patient-specific iPSC lines and their neuronal derivatives will allow academic groups and pharmaceutical companies to study pathogenesis and test experimental therapeutics for HD, which will significantly advance both our understanding of HD and potential treatments for this devastating and currently untreatable disease.

Stem cell based small molecule therapy for Alzheimer's disease

Funding Type: 
Early Translational III
Grant Number: 
TR3-05669
ICOC Funds Committed: 
$1 673 757
Disease Focus: 
Alzheimer's Disease
Neurological Disorders
Stem Cell Use: 
Embryonic Stem Cell
Cell Line Generation: 
Embryonic Stem Cell
oldStatus: 
Active
Public Abstract: 
Over 6 million people in the US suffer from AD. There are no drugs that prevent the death of nerve cells in AD, nor has any drug been identified that can stimulate their replacement. Even if nerve cells could be replaced, the toxic environment of the brain will kill them unless they are protected by a drug. Therefore, drugs that stimulate the generation of new neurons (neurogenesis) alone will not be effective; a drug with both neurogenic and neuroprotective properties is required. With the ability to use cells derived from human embryonic stem cells (hESCs) as a screen for neurogenic compounds, it should now be possible to identify and tailor drugs for therapeutic use in AD. Our laboratory has developed a drug discovery scheme based upon using hESCs to screen drug candidates. We have recently identified a very potent drug that is exceptionally effective in rodent models of AD. However, this molecule needs to be optimized for human use. In this proposal, we will harness the power of hESCs to develop derivatives of J147 specifically tailored to stimulate neurogenesis and be neuroprotective in human cells. This work will optimize the chances for its true therapeutic potential in AD, and presents a unique opportunity to expand the use of hESCs for the development of a therapeutic for a disease for which there is no cure. This work could lead to a paradigm shift in the treatment of neurodegenerative disease.
Statement of Benefit to California: 
Over 6 million people in the US suffer from Alzheimer’s disease (AD). Unless a viable therapeutic is identified it is estimated that this number will increase to 16 million by 2050, with a cost of well over $1 trillion per year, overwhelming California and national health care systems. Among the top 10 causes of death, AD (6th) is the only one with no treatment available to prevent, cure or slow down the condition. An enormous additional burden to families is the emotional and physical stress of having to deal with a family member with a disease which is going to become much more frequent with our aging population. In this application we use new human stem cell technologies to develop an AD drug candidate based upon a strong lead compound that we have already made that stimulates the multiplication of nerve precursor cells derived from human embryonic stem cells. This approach presents a unique opportunity to expand the use of human embryonic stem cells for the development of a therapeutic for a disease for which there is no cure, and could lead to a paradigm shift in the treatment of neurodegenerative disease. Since our AD drug discovery approach is fundamentally different from the unsuccessful approaches used by the pharmaceutical industry, it could also stimulate new biotech. The work in this proposal addresses one of the most important medical problems of California as well as the rest of the world, and if successful would benefit all.
Progress Report: 
  • Introduction: Over 6 million people in the US suffer from AD. There are no drugs that prevent the death of nerve cells in AD, nor has any drug been identified that can stimulate their replacement. Even if nerve cells could be replaced, the toxic environment of the brain will kill them unless they are protected by a drug. Therefore, drugs that stimulate the generation of new neurons (neurogenesis) alone will not be effective; a drug with both neurogenic and neuroprotective properties is required. With the ability to use cells derived from human embryonic stem cells (hESCs) as a screen for neurogenic compounds, it should now be possible to identify and tailor drugs for therapeutic use in AD. This is the overall goal of this application.
  • Year One Progress: Using a novel drug discovery paradigm, we have made a very potent drug called J147 that is exceptionally effective in rodent models of AD and also stimulates neurogenesis in both young and very old mice. Very few, if any, drugs or drug candidates are both neuroprotective and neurogenic, particularly in old animals. In the first year of this application we harnessed the power of hESCs and medicinal chemistry to develop derivatives of J147 specifically tailored to stimulate neurogenesis and be neuroprotective in human cells. Using iterative chemistry, we synthesized over 200 new compounds, tested them for neurogenic properties in ES-derived neural precursor cells, assayed their ability to protect from the amyloid toxicity associated with AD, and determined their metabolic stability. All of the year one milestones we met and we now have the required minimum of six compounds to move into year two studies. In addition, we have made a good start on the work for year two in that some pharmacokinetics and safety studies has been completed.
  • This work will optimize the chances for its true therapeutic potential in AD, and presents a unique opportunity to expand the use of hESCs for the development of a therapeutic for a disease for which there is no cure. This work could lead to a paradigm shift in the treatment of neurodegenerative disease.
  • Introduction: Over 6 million people in the US suffer from Alzheimer’s disease (AD). There are no drugs that prevent the death of nerve cells in AD, nor has any drug been identified that can stimulate their replacement. Even if nerve cells could be replaced, the toxic environment of the brain will kill them unless they are protected by a drug. Therefore, drugs that stimulate the generation of new neurons (neurogenesis) alone will not be effective; a drug with both neurogenic and neuroprotective properties is required. With the ability to use cells derived from human embryonic stem cells (hESCs) as a screen to identify neurogenic compounds, we have shown that it is now be possible to identify and tailor drugs for therapeutic use in AD. This was the overall goal of this application, and to date we have made outstanding progress, making a drug that is both neurogenic for human cells and has therapeutic efficacy in a rigorous mouse model of AD.
  • Year 2 Progress: Using a novel drug discovery paradigm based upon human stem cell derived nerve precursor cells, we have made a very potent drug called CAD-31. CAD-31 potently stimulates neurogenesis in human cells in culture and in mice, and prevents nerve cell death in cell culture models of toxicities associated with old age and AD. Very few, if any, drugs or drug candidates are both neuroprotective and neurogenic, particularly in animals. In the first year of this project, we harnessed the power of hESCs and medicinal chemistry to develop CAD-31. All of the Year 1 milestones were met. In Year 2 we completed all of the required pharmacokinetics and safety studies on the six best compounds synthesized in Year 1. Of those six, one compound, CAD-31, was the best in terms of medicinal chemical, pharmacokinetic, neuroprotective and neurogenic properties. This compound underwent extensive testing for safety and passed with flying colors. It was then put into an AD mouse model where it stimulated neurogenesis, prevented behavioral deficits and some of the disease pathology. All Year 2 milestones were completed. In Year 3 of the project we will determine if CAD-31 is able to reverse AD symptoms in old AD mice that already have the disease. This is the most clinically relevant model of AD since therapies can only be initiated once the disease is identified.
  • This work has produced a novel AD drug candidate that is developed based upon a set of assays never before used by pharmaceutical companies. It presents a unique opportunity to expand the use of hESCs for the development of a therapeutic for a disease for which there is no cure. This work could lead to a paradigm shift in drug discovery for the treatment of neurodegenerative disease.

Targeting Stem Cells to Enhance Remyelination in the Treatment of Multiple Sclerosis

Funding Type: 
Early Translational III
Grant Number: 
TR3-05617
ICOC Funds Committed: 
$4 327 175
Disease Focus: 
Multiple Sclerosis
Neurological Disorders
Stem Cell Use: 
Adult Stem Cell
Cell Line Generation: 
Adult Stem Cell
oldStatus: 
Active
Public Abstract: 
Multiple sclerosis (MS) is an autoimmune disease in which the myelin sheath that insulates neurons is destroyed, resulting in loss of proper neuronal function. Existing treatments for MS are based on strategies that suppress the immune response. While these drugs do provide benefit by reducing relapses and delaying progression (but have significant side effects), the disease invariably progresses. We are pursuing an alternative therapy aimed at regeneration of the myelin sheath through drugs that act on an endogenous stem cell population in the central nervous system termed oligodendrocyte precursor cells (OPCs). Remission in MS is largely dependent upon OPCs migrating to sites of injury and subsequently differentiating into oligodendrocytes – the cells that synthesize myelin and are capable of neuronal repair. Previous studies indicate that in progressive MS, OPCs are abundantly present at sites of damage but fail to differentiate to oligodendrocytes. As such, drug-like molecules capable of inducing OPC differentiation should have significant potential, used alone or in combination with existing immunomodulatory agents, for the treatment of MS. The objective of this project is to identify a development candidate (DC) for the treatment of multiple sclerosis (MS) that functions by directly stimulating the differentiation of the adult stem cells required for remyelination.
Statement of Benefit to California: 
Multiple Sclerosis (MS) is a painful, neurodegenerative disease that leads to an impairment of physical and cognitive abilities. Patients with MS are often forced to stop working because their condition becomes so limiting. MS can interfere with a patient's ability to even perform simple routine daily activities, resulting in a decreased quality of life. Existing treatments for MS delay disease progression and minimize symptoms, however, the disease invariably progresses to a state of chronic demyelination. The goal of this project is to identify novel promyelinating drugs, based on differentiation of an endogenous stem cell population. Such drugs would be used in combination with existing immunosuppressive drugs to prevent disease progression and restore proper neuronal activity. More effective MS treatment strategies represent a major unmet medical need that could impact the roughly 50,000 Californians suffering from this disease. Clearly the development of a promyelinating therapeutic would have a significant impact on the well-being of Californians and reduce the negative economic impact on the state resulting from this degenerative disease.
Progress Report: 
  • Multiple sclerosis (MS) is an autoimmune disease characterized by the destruction of the myelin sheath that insulates neurons, resulting in loss of proper neuronal function. Existing treatments for MS are based exclusively on strategies that suppress the immune response. We are pursuing an alternative stem cell-based therapeutic approach aimed at enhancing regeneration of the myelin sheath. Specifically, we are focused on the identification of drug-like molecules capable of inducing oligodendrocyte precursor cell (OPC) differentiation. To date, we have identified a series approved drugs that effectively induce OPC differentiation under tissue culture conditions. Additionally, we have demonstrated that several of these drug candidates reduce MS-like symptoms in relevant rodent models of the disease. We are currently conducting detailed pharmacology experiments to determine which of the identified molecules will serve as the best candidate for future clinical development.
  • The aim of this project is to identify and characterize molecules that induce the repair of lesions in multiple sclerosis. Molecules that induce the selective differentiation of oligodendrocyte precursor cells to oligodendrocytes and thereby lead to remyelination of axons are being characterized with respect to their in vitro activity and in vivo efficacy in relevant animal models, alone and in combination with immunosuppressive drugs. This work may lead to a new regenerative therapy for multiple sclerosis that is complementary to the current immune-focused therapies.

Molecules to Correct Aberrant RNA Signature in Human Diseased Neurons

Funding Type: 
Early Translational III
Grant Number: 
TR3-05676
ICOC Funds Committed: 
$1 654 830
Disease Focus: 
Amyotrophic Lateral Sclerosis
Neurological Disorders
Stem Cell Use: 
iPS Cell
Cell Line Generation: 
iPS Cell
oldStatus: 
Active
Public Abstract: 
Approximately 5,600 people in the U.S. are diagnosed with ALS each year. The incidence of ALS is two per 100,000 people, and it is estimated that as many as 30,000 Americans may have the disease at any given time. There are no effective therapies of ALS to-date. Recent genetic discoveries have pinpointed mutations that lead to the aberrant function of two proteins that bind to RNA transcripts in neurons. Misregulation of these RNA binding proteins is responsible for the aberrant levels and processing of hundreds of RNA representing genes that are important for neuronal survival and function. In this proposal, we will use neurons generated from patient cells that harbor the mutations in these RNA binding proteins to (1) prioritize a RNA “signature” unique to neurons suffering from the toxic function of these proteins and (2) as an abundant source of raw material to enable high-throughput screens of drug-like compounds that will bypass the mutations in the proteins and “correct” the RNA signature to resemble that of a healthy neuron. If successful, our unconventional approach that uses hundreds of parallel measurements of specific RNA events, will identify drugs that will treat ALS patients.
Statement of Benefit to California: 
Our research aims to develop drug-like compounds that are aimed to treat Amyotrophic Lateral Sclerosis (ALS), which may be applicable to other neurological diseases that heavily impact Californians, such as Frontotemporal Lobar Degeneration, Parkinson’s and Alzheimer’s. The cellular resources and genomic assays that we are developing in this research will have great potential for future research and can be applied to other disease areas. The cells, in particular will be beneficial to California health care patients, pharmaceutical and biotechnology industries in terms of improved human models for drug discovery and toxicology testing. Our improved knowledge base will support our efforts as well as other Californian researchers to study stem cell models of neurological disease and design new diagnostics and treatments, thereby maintaining California's position as a leader in clinical research.
Progress Report: 
  • Our research aims to develop drug-like compounds that are aimed to treat Amyotrophic Lateral Sclerosis (ALS), which may be applicable to other neurological diseases that heavily impact Californians, such as Frontotemporal Lobar Degeneration, Parkinson’s and Alzheimer’s. In the first year, we have succeeded in improving the efficiency of motor neuron differentiation to generate high-quality motor neurons from induced pluripotent stem cells. We have generated RNA signatures from motor neurons differentiated from induced pluripotent stem cells from normal, healthy individuals whereby key proteins implicated in ALS are depleted using RNAi technology. We have also generated motor neurons from induced pluripotent stem cells that contained mutations in these key proteins and are in the process of applying genomic technologies to compare these cells to ones where we have depleted the proteins themselves. In parallel, we have started to optimize conditions for a small molecule screen to identify previously FDA-approved compounds that may alter aberrant and ALS-associated phenotypes in human cell lines.
  • In this reporting period, we have successfully generated lines that we have used to identify small molecules that alter the formation of aggregates in human neural progenitors and non-neuronal cell lines. These molecules will be tested for the reversal of aberrant RNA signatures in motor neurons from patients with ALS-associated mutations.

Neural and general splicing factors control self-renewal, neural survival and differentiation

Funding Type: 
Basic Biology III
Grant Number: 
RB3-05009
ICOC Funds Committed: 
$1 372 660
Disease Focus: 
Amyotrophic Lateral Sclerosis
Neurological Disorders
Dementia
Stem Cell Use: 
Embryonic Stem Cell
Cell Line Generation: 
iPS Cell
oldStatus: 
Active
Public Abstract: 
Human embryonic and patient-specific induced pluripotent stem cells have the remarkable capacity to differentiate into many cell-types, including neurons, thus enabling the modeling of human neurological diseases in vitro, and permit the screening of molecules to correct diseases. Maintaining the pluripotent state of the stem cell, directing the stem cell towards a neuronal lineage, keeping the neuronal progenitor and stem cells alive - these are all maintained by thousands of different proteins in the cell at these different "stages". Thus the levels and types of proteins are highly controlled by gene regulatory mechanisms. Genes produce pre-messenger RNA (mRNA) transcripts in the nucleus, which undergo a process of refinement called splicing, whereby long (1,000-100,000 bases) stretches of nucleotides are excised, and much shorter pieces (150 bases) are ligated together to form mature messenger RNA to eventually make proteins in the cytoplasm. Strikingly, some pieces of RNA are used in a particular cell-type, but not another, in a process called "alternative splicing". This is the most prevalent form of generating transcriptome diversity in the human genome, and is important for pushing cells from one state to another i.e. stem cells to neurons, maintaining a cell state i.e. keeping a stem cell pluripotent, or a neuron alive and functioning. Alternative splicing is highly controlled by the recognition of even smaller stretches (6-10 bases) of RNA binding sites) by proteins that bind directly to RNA called splicing factors. The goal of the proposed research is to produce a regulatory map of where these splicing factors bind within pre-mRNAs across the entire human genome with unprecedented resolution using a high-throughput biochemical strategy. Furthermore, using advanced genomic technologies, we will deduce what happens to splicing when these factors do not bind to their binding sites. Finally, using molecular and imaging methods, we will analyze what happens to survival of stem and neuronal cells when these factors are depleted or over-expressed, and if stem cells are induced to make neurons if the levels of these factors are altered. Completion of the proposed research is expected to transform our understanding of the regulatory mechanisms underlying transcriptome complexity important for neurological disease modeling, especially human neurodegeneration, and stem cell biology. In turn, this will facilitate more accurate comparisons of diseased states of neurons from stem-cell models of Amyotrophic Lateral Sclerosis (ALS), Myotonic Dystropy, Spinal Muscular Atrophy (SMA), Parkinson’s and Alzheimer’s to identify mis-spliced genes and the splicing factors responsible for therapeutic intervention.
Statement of Benefit to California: 
Our research provides the foundation for decoding the mechanisms that control the transcriptome complexity of stem cells and neurons derived from stem cells. Our work has direct application in the design of novel strategies to understand the impact of splicing factor misregulation, or mutations within the binding sites for these splicing factors in neurological diseases that heavily impact Californians, such as Amyotrophic Lateral Sclerosis (ALS), Myotonic Dystropy, Spinal Muscular Atrophy (SMA), Parkinson’s and Alzheimer’s. Our research has and will continue to serve as a basis for understanding deviations from "normal" stem and neuronal cells, enabling us to make inroards to understanding neurological disease modeling using neurons differentiated from reprogammed patient-specific lines. Such disease modeling will have great potential for California health care patients, pharmaceutical and biotechnology industries in terms of improved human models for drug discovery and toxicology testing. Our improved knowledge base will support our efforts as well as other Californian researchers to study stem cell models of neurological disease and regenerative medicine, and for the design of new diagnostics and treatments, thereby maintaining California's position as a leader in clinical and biomedical research.
Progress Report: 
  • The overwhelming majority of human genes undergo extensive alternative splicing, but save for several dozens of these regulated splicing events, it is not known which proteins are responsible for controlling these key splicing decisions. Furthermore, mutations in several of these proteins, known as splicing factors, have recently been shown to be causative of neurodegeneration. In this proposal we aim to understand the importance of splicing factor regulation of alternative splicing in controlling pluripotency, fate decision towards the neural lineage and neuronal survival. In our recent publication in Cell Reports, Huelga et al demonstrated that the ubiquitously expressed heterogeneous nuclear ribonucleoproteins (hnRNPs) commonly cooperate and antagonize one another to regulate alternative splicing in a somatic human cell-line. In year one of this grant, we have interrogated several key members of these hnRNP proteins in human neural progenitor and differentiated neurons from embryonic stem cells and induced pluripotent stem cells.
  • The overwhelming majority of human genes undergo extensive alternative splicing, but save for several dozens of these regulated splicing events, it is not known which proteins are responsible for controlling these key splicing decisions. Furthermore, mutations in several of these proteins, known as splicing factors, have recently been shown to be causative of neurodegeneration. In this proposal we aim to understand the importance of splicing factor regulation of alternative splicing in controlling pluripotency, fate decision towards the neural lineage and neuronal survival. In years one and two, we have made significant progress in analyzing the functions of three hnRNP proteins, namely TAF15, EWSR1 and hnRNP A2/B1. All three have been associated with neurological diseases, in particular ALS and FTD. We have also made progress in generating and successfully validating reagents to deplete the larger class of RNA binding proteins in human neural progenitors. Finally, we are making slower but steady progress in depleting RBFOX proteins in human neurons.
  • The overwhelming majority of human genes undergo extensive alternative splicing, but save for several dozens of these regulated splicing events, it is not known which proteins are responsible for controlling these key splicing decisions. Furthermore, mutations in several of these proteins, known as splicing factors, have recently been shown to be causative of neurodegeneration. In this proposal we aim to understand the importance of splicing factor regulation of alternative splicing in controlling pluripotency, fate decision towards the neural lineage and neuronal survival. In year 3 of the proposal, we have completed a deeper analysis of hnRNP A2/B1 which we are preparing for manuscript submission. HnRNP A2/B1 is implicated in neurological diseases such as ALS and FTD.

Use of iPS cells (iPSCs) to develop novels tools for the treatment of spinal muscular atrophy.

Funding Type: 
Tools and Technologies II
Grant Number: 
RT2-02040
ICOC Funds Committed: 
$1 933 022
Disease Focus: 
Spinal Muscular Atrophy
Neurological Disorders
Pediatrics
Stem Cell Use: 
iPS Cell
Cell Line Generation: 
Adult Stem Cell
oldStatus: 
Active
Public Abstract: 
Spinal Muscular Atrophy (SMA) is one of the most common lethal genetic diseases in children. One in thirty five people carry a mutation in a gene called survival of motor neurons 1 (SMN1) which is responsible for this disease. If two carriers have children together they have a one in four chance of having a child with SMA. Children with Type I SMA seem fine until around 6 months of age, at which time they begin to show lack of muscular development and slowly develop a "floppy" syndrome over the next 6 months. Following this period, SMA children become less able to move and are eventually paralyzed by the disease by 3 years of age or earlier. We know that this mutation causes the death of motor neurons - which are important for making muscle cells work. Interestingly, there is a second gene which can lessen the severity of the disease process (SMN2). Children with more copies of this modifying gene have less severe symptoms and can live for longer periods of time (designated Type II, III and IV and living longer periods respectively). There is no therapy for SMA at the current time. One of the roadblocks is that there are no human models for this disorder as it is very difficult to make the motor neurons that die in the disease in the laboratory. The researchers in the current proposal have recently created pluripotent stem cells from a patient with Type I SMA (the most severe) and shown that motor neurons grown out from the pluripotent stem cells also die in the culture dish just like they do in children. This is an important model for SMA. The proposed research takes this model of SMA and extends it to Type II and Type III children in order to have a wider range of disease severity in the culture dish (Type IV is very rare and difficult to get samples from). It then develops new technologies to produce very large numbers of motor neurons and perform large scale analysis of their survival profiles. Finally, it will explore whether novel compounds can slow down the degeneration of motor neurons in this model which should lead to the discovery of dew drugs that then may be used to treat the disease.
Statement of Benefit to California: 
The aim of this research is to develop novel drugs to treat a lethal childhood disease - SMA. There would be three immediate benefits to the state of California and its citizens. 1. Children in California would have access to novel drugs to slow or prevent their disease. 2. SMA is a world wide disease. The institutions involved with the research would be able to generate income from any new drugs developed and the profit from this would come back to California. 3. The project will employ a number of research staff in Californian institutions
Progress Report: 
  • This year we have created a large number of new SMA lines, developed ways to differentiate them into motor neurons using high content dishes, and begun to analyze the health of the motor neurons over time. We have also submitted a new paper showing that much of the cell death seen in the dying motor neurons is due to apoptosis - a form of cell death that is treatable with specific types of drug. We are now using these new lines to begin setting up screening runs with drug libraries and should be able to start these in the new year of funding.
  • In this year we have made more induced pluripotent stem (iPSC) cell lines from Spinal Muscular Atrophy patients also using blood cells in addition to skin cells. Blood cells from patients are usually more readi;y accessible. As such, this technique can be used to make larger bank of similar cell lines. We have also rigorously tested all the iPSCs them for their quality. These lines are now available for distribution to other California researchers along with a certificate of analysis.
  • Motor neurons are a type of neuron that control muscle movement and are markedly destroyed in SMA patients. In order for these powerful iPS cells form patients to be useful for discovering new drugs for SMA it is very important that we can make motor neurons from iPSCs in large quantities of millions to billions in number. Only then will testing of thousands to millions of new drugs would be feasible in neurons from SMA patients. To this end, we have created a method for making a predecessor cell type to human motor neurons from human iPSCs in a petri dish. These predecessor cells, known as motor neuron precursor spheres (iMNPS), are grown as clumps of floating spherical balls, each containing thousands such cells that are grown in large numbers repeatedly for long periods of time. We have made these iMNPS now from many SMA patients as well as healthy humans. These spheres can be preserved for long period of time by freezing them at very low temperatures. They are then awoken at a later time making it convenient for testing large numbers of drugs.
  • Since iPSCs have the power to make any cell type in the human body, they can also be contaminated with other unwanted types of cells. Typically such a technique is very difficult to accomplish in pluripotent stem cells such as embryonic and iPSCs. Therefore, we have designed a more efficient scheme to generate iPSC lines from SMA patients that will become fluorescent color (green, red or blue) when then motor neurons are made from iPSCs. These types of cells are known as reporter cell lines. This will aid in picking out the desired cell type from patient iPSCs, in this case a motor neuron, and discard any unwanted cell types. This will enormously simplify testing of new drugs in SMA patient motor neurons.
  • Deficiency of an important protein in SMA patients is one of the key causes to the course of the disease. We have also designed an automated method for identifying new drugs in patient motor neurons that will test for correction of SMN protein levels in motor neurons.
  • In Year 3 we completed making all iPSC lines from Spinal Muscular Atrophy patients. We rigorously tested all the iPSCs for quality. These lines are now available for distribution to other California researchers along with a quality control certificate.
  • Motor neurons are a type of neuron that control muscle movement and are markedly destroyed in SMA patients. In order for these powerful iPS cells form patients to be useful for discovering new drugs for SMA it is very important that we can make motor neurons from iPSCs in billions and repeatedly. Only then will testing of thousands to millions of new drugs would be feasible in neurons from SMA patients.
  • To this end, we have created a method for making a predecessor cell type to human motor neurons from human iPSCs in a petri dish. These predecessor cells, known as motor neuron precursor spheres (iMPS), are grown as clumps of floating spherical balls, each containing thousands such cells that are grown in large numbers repeatedly for long periods of time. We have now tested our method in multiple patient cells and characterized these spheres. The iMPS have now been produced from many SMA patients as well as healthy humans. The next step we have developed is to take the iMPS to make motor neurons that are similar to those that are affected in SMA children. We have then discovered a method for creating them quickly. These aggregate spheres and spinal cord motor neurons from them can be preserved for long period of time by freezing them at very low temperatures. They are then awoken at a later time making it convenient for testing large numbers of drugs.
  • Since iPSCs have the power to make any cell type in the human body, they can also be contaminated with other unwanted types of cells. Typically such a technique is very difficult to accomplish in pluripotent stem cells such as embryonic and iPSCs. Therefore, we have designed a more efficient scheme to generate iPSC lines from SMA patients that will become fluorescent color (green, red or blue) when then motor neurons are made from iPSCs. These types of cells are known as reporter cell lines. This will aid in picking out the desired cell type from patient iPSCs, in this case a motor neuron, and discard any unwanted cell types. This will enormously simplify testing of new drugs in SMA patient motor neurons. Using new technologies that can edit, cut, copy, and paste new DNA in the stem cell genome, we are also developing ways to engineer iPS cell lines that will tag the motor neurons when they are made. This will allow us another method for making pure motor neurons and tracking them in a dish among other types of cells while they are alive.
  • Deficiency of an important SMN protein in SMA patients is one of the key causes to the course of the disease. An automated method has been developed for identifying what causes the SMA neurons to become sick and test new drugs in motor neurons. We are now gearing up to test some ~1400 known compounds on patient motor neurons to determine whether we can raise SMN protein levels in motor neurons.

Development of Single Cell MRI Technology using Genetically-Encoded Iron-Based Reporters

Funding Type: 
Tools and Technologies II
Grant Number: 
RT2-02018
ICOC Funds Committed: 
$1 930 608
Disease Focus: 
Stroke
Neurological Disorders
Stem Cell Use: 
Adult Stem Cell
oldStatus: 
Active
Public Abstract: 
Clinical application of cell transplantation therapy requires a means of non-invasively monitoring these cells in the patient. Several imaging modalities, including MRI, bioluminescence imaging, and positron emission tomography have been used to track stem cells in vivo. For MR imaging, cells are pre-loaded with molecules or particles that substantially alter the image brightness; the most common such labelling strategy employs iron oxide particles. Several studies have shown the ability of MRI to longitudinally track transplanted iron-labeled cells in different animal models, including stroke and cancer. But there are drawbacks to this kind of labeling. Division of cells will result in the dilution of particles and loss of signal. False signal can be detected from dying cells or if the cells of interest are ingested by other cells. To overcome these roadblocks in the drive toward clinical implementation of stem cell tracking, it is now believed that a genetic labeling approach will be necessary, whereby specific protein expression causes the formation of suitable contrast agents. Such endogenous and persistent generation of cellular contrast would be particularly valuable to the field of stem cell therapy, where the homing ability of transplanted stem cells, long-term viability, and capacity for differentiation are all known to strongly influence therapeutic outcomes. However, genetic labeling or "gene reporter" strategies that permit sensitive detection of rare cells, non-invasively and deep in tissue, have not yet been developed. This is therefore the translational bottleneck that we propose to address in this grant, through the development and validation of a novel high-sensitivity MRI gene reporter technology. There have been recent reports of gene-mediated cellular production of magnetic iron-oxide nanoparticles of the same composition as the synthetic iron oxide particles used widely in exogenous labeling studies. It is an extension of this strategy, combined with our own strengths in developing high-sensitivity MRI technology, that we propose to apply to the task of single cell tracking of metastatic cancer cells and neural stem cells. If we are successful with the proposed studies, we will have substantially advanced the field of in vivo cellular imaging, by providing a stable cell tracking technology that could be used to study events occurring at arbitrary depth in tissue (unlike optical methods) and over unlimited time duration and arbitrary number of cell divisions (unlike conventional cellular MRI). With the ability to track not only the fate (migration, homing and proliferation) but also the viability and function of very small numbers of stem cells will come new knowledge of the behavior of these cells in a far more relevant micro-environment compared with current in vitro models, and yet with far better visualization and cell detection sensitivity compared with other in vivo imaging methods.
Statement of Benefit to California: 
Stem cell therapy has enormous promise to become a viable therapy for a range of illnesses, including stroke, other cardiovascular diseases, and neurological diseases. Progress in the development of these therapies depends on the ability to monitor cell delivery, migration and therapeutic action at the disease site, using imaging and other non-invasive technologies. If breakthroughs could be made along these lines, it would not only be of enormous benefit to the citizens of the state of California, but would also greatly reduce healthcare costs. From a broader research perspective, the state of California is the front-runner in stem cell research, having gathered not only private investments, as demonstrated by the numerous biotechnology companies that are developing innovative tools, but also extensive public funds that allows the state, through CIRM, to sponsor stem cell research in public and private institutions. In order to preserve the leadership position and encourage research on stem cells, CIRM is calling for research proposals to develop innovative tools and technologies that will overcome current roadblocks in translational stem cell research. This proposal will benefit the state by providing important new technology that will be valuable for both basic and translational stem cell research. A key bottleneck to the further development and translation of new stem cell therapies is the inability to track stem cells through a human body. It is possible to image stem cells using embedded optical fluorescence labels, but optical imaging does not permit tracking of cells deep in tissue. Other imaging modalities and their associated cellular labels (for example positron emission tomography) have also been used to track cells but do not have the sensitivity to detect rare or single cells. Finally, MRI has been used to track cells deep in tissue, down to the single cell level, but only by pre-loading cells with a non-renewable supply of iron oxide nanoparticles, which prevents long-term tracking and assessment of cell viability and function. We propose here to develop MRI technology and a new form of genetically-encoded, long-term cell labeling technology, to a much more advanced state than available at present. This will make it possible to use MRI to detect and follow cancer and stem cells as they migrate to and proliferate at the site of interest, even starting from the single cell stage. This will provide a technology that will help stem cell researchers, first and foremost in California, to understand stem cell behavior in a realistic in vivo environment. This technology will be translatable to future human stem cell research studies.
Progress Report: 
  • We have made good progress in the first year. This project involves four separate scientific teams, brought together for the first time, representing diverse backgrounds ranging from magnetic resonance imaging (MRI) physics and cell tracking (Dr. Rutt), microbiology (Dr. Matin), nano and magnetic characterization (Dr. Moler) and stem cell imaging in stroke models (Dr. Guzman). Substantial progress has been made by all four teams, and we are starting to see important interactions between the teams. An overall summary of progress is that we have evaluated three different bacterial genes (magA, mms6, mamB) in one mammalian cell line (MDA-MB-231BR) and have shown significant iron accumulation in vitro with two of these genes, which is a very positive result implying that these genes may have the required characteristics to act as "reporter genes" for MRI-based tracking of cells labeled with these genes. MR imaging of mouse brain specimens has yielded promising results and in vivo imaging experiments are underway at medium MRI field strength (3 Tesla). At the same time, we are ramping up our higher field, higher sensitivity MR imaging methods and will be ready to evaluate the different variations of our MR reporter gene at 7 Tesla (the highest magnetic field widely available for human MRI) in the near future. Finally, methods to perform quantitative characterization of our reporter cells are being developed, with the goal of being able to characterize magnetic properties down to the single cell level, and also to be able to assess iron loading levels down to the single level in brain tissue slices.
  • We have made good progress in the second year. This project involves four separate scientific teams, brought together for the first time for this project, representing diverse backgrounds ranging from magnetic resonance imaging (MRI) physics and cell tracking (Dr. Rutt), microbiology (Dr. Matin), nano and magnetic characterization (Dr. Moler) and imaging reporter development and testing in small animal models of disease (Dr. Contag). Substantial progress has been made by all four teams, and we are starting to see important interactions between the teams.
  • An overall summary of progress is that we have been evaluating three different bacterial genes (magA, mms6, mamB) in two mammalian cell lines (MDA-MB-231BR and DAOY). In year I we had shown significant iron accumulation in vitro with two of these genes, which was a very positive result implying that these genes may have the required characteristics to act as "reporter genes" for MRI-based tracking of cells labeled with these genes. In year 2, we diversified and intensified the efforts to achieve expression of one or more of the bacterial genes in different cell lines, using different genetic constructs. We began a concerted effort to achieve optical labeling such that we could visualize the gene expression and to identify sub-cellular localization of the report gene products.
  • We obtained promising results from MR imaging of mouse brain. In vivo imaging experiments were accomplished at medium MRI field strength (3 Tesla). At the same time, we ramped up our higher field, higher sensitivity MR imaging methods and began to evaluate the sensitivity gains enabled at the higher magnetic field strength of 7 Tesla (the highest magnetic field widely available for human MRI
  • Finally, methods to perform quantitative characterization of our reporter cells were developed, with the goal of being able to characterize magnetic properties down to the single cell level, and also to be able to assess iron loading levels down to the single level in brain tissue slices.
  • We have made good progress in the third year. This project involves four separate scientific teams, brought together for the first time for this project, representing diverse backgrounds ranging from magnetic resonance imaging (MRI) physics and cell tracking (Dr. Rutt), microbiology (Dr. Matin), nano and magnetic characterization (Dr. Moler) and imaging reporter development and testing in small animal models of disease (Dr. Contag). Substantial progress has been made by all four teams, and we have benefited from important interactions between all teams in this third year.
  • An overall summary of progress is that we evaluated several iron-binding bacterial genes (magA, mamB, mms6, mms13), both singly and doubly, in two mammalian cell lines (MDA-MB-231BR and DAOY). In year 2, we diversified and intensified the efforts to achieve expression of one or more of the bacterial genes in different cell lines, using different genetic constructs. We completed an effort to achieve optical labeling such that we could visualize the gene expression and to identify sub-cellular localization of the report gene products. In year 3, while continuing to face challenges with single gene constructs, we succeeded in finding substantial iron uptake in cells containing unique double gene expression, notably magA and mms13.
  • We completed much of the development of our higher field, higher sensitivity MR imaging methods and evaluated the sensitivity gains enabled at the higher magnetic field strength of 7 Tesla (the highest magnetic field widely available for human MRI).
  • Finally, we demonstrated novel nanomagnetic methods to characterize our reporter cells, able to characterize magnetic properties down to the single cell level.
  • We have made good progress during this 6-month extension period. This project involves four separate scientific teams, brought together for the first time for this project, representing diverse backgrounds ranging from magnetic resonance imaging (MRI) physics and cell tracking (Dr. Rutt), microbiology (Dr. Matin), nano and magnetic characterization (Dr. Moler) and imaging reporter development and testing in small animal models of disease (Dr. Contag). Substantial progress has been made by all four teams, and we have benefited from important interactions between all teams in this third year.
  • An overall summary of progress is that we evaluated several iron-binding bacterial genes (magA, mamB, mms6, mms13), singly, doubly and triply, in several mammalian cell lines (MDA-MB-231BR, DAOY, COS1, 293FT). In year 3 as well as through the extension period, we succeeded in finding substantial iron uptake in cells containing certain expressed genes, notably mms13 by itself, as well as combinations of mms13 with mms6 and mamB.
  • We completed the development of our higher field, higher sensitivity MR imaging methods and evaluated the sensitivity gains enabled at the higher magnetic field strength of 7 Tesla (the highest magnetic field widely available for human MRI).
  • Finally, we demonstrated novel nanomagnetic methods to characterize our reporter cells, able to characterize magnetic properties down to the single cell level.

Development of small molecule screens for autism using patient-derived iPS cells

Funding Type: 
Tools and Technologies II
Grant Number: 
RT2-01906
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.

Identifying Drugs for Alzheimer's Disease with Human Neurons Made From Human IPS cells

Funding Type: 
Early Translational III
Grant Number: 
TR3-05577
ICOC Funds Committed: 
$1 857 600
Disease Focus: 
Alzheimer's Disease
Neurological Disorders
Stem Cell Use: 
iPS Cell
Cell Line Generation: 
iPS Cell
oldStatus: 
Active
Public Abstract: 
We propose to discover new drug candidates for Alzheimer’s Disease (AD), which is common, fatal, and for which no effective disease-modifying drugs are available. Because no effective AD treatment is available or imminent, we propose to discover novel candidates by screening purified human brain cells made from human reprogrammed stem cells (human IPS cells or hIPSC) from patients that have rare and aggressive hereditary forms of AD. We have already discovered that such human brain cells exhibit an unique biochemical behavior that indicates early development of AD in a dish. Thus, we hope to find new drugs by using the new tools of human stem cells that were previously unavailable. We think that human brain cells in a dish will succeed where animal models and other types of cells have thus far failed.
Statement of Benefit to California: 
Alzheimer’s Disease (AD) is a fatal neurodegenerative disease that afflicts millions of Californians. The emotional and financial impact on families and on the state healthcare budget is enormous. This project seeks to find new drugs to treat this terrible disease. If we are successful our work in the long-term may help diminish the social and familial cost of AD, and lead to establishment of new businesses in California using our approaches to drug discovery for AD.
Progress Report: 
  • We have made steady and significant progress in developing a way to use human reprogrammed stem cells to develop drugs for Alzheimer's disease. In the more recent project term we have further refined our key assay, and generated sufficient cells to enable screening of 50,000 different chemical candidates that might reveal potential drugs for this terrible disease. With a little bit of additional refinement, we will be able to begin our search in earnest in collaboration with the Sanford-Burnham Prebys Screening Center.
  • During the past year we completed screening of our Alzheimers “disease in a dish” cultured stem cell lines for response of a critical measure of Alzheimers disease in a dish to FDA approved drugs and other potentially promising drug like compounds. We found several reproducible and interesting categories of potential drugs some of which are already in common use in human patients and therefore might be readily available to the Alzheimer's disease population. We are conducting more careful analyses of these drugs for their mechanism and behavior in human neurons with different types of Alzheimer like behavior and we are beginning to test whether all human variants behave the same way as preparation for potential clinical trials. We are also initiating analysis of new chemical entities for possible modification to improve potency.

Engineering microscale tissue constructs from human pluripotent stem cells

Funding Type: 
Research Leadership 14
Grant Number: 
LA1_C14-08015
ICOC Funds Committed: 
$6 368 285
Disease Focus: 
Heart Disease
Neurological Disorders
Pediatrics
Stem Cell Use: 
Embryonic Stem Cell
iPS Cell
Directly Reprogrammed Cell
Public Abstract: 
Tissues derived from stem cells can serve multiple purposes to enhance biomedical therapies. Human tissues engineered from stem cells hold tremendous potential to serve as better substrates for the discovery and development of new drugs, accurately model development or disease progression, and one day ultimately be used directly to repair, restore and replace traumatically injured and chronically degenerative organs. However, realizing the full potential of stem cells for regenerative medicine applications will require the ability to produce constructs that not only resemble the structure of real tissues, but also recapitulate appropriate physiological functions. In addition, engineered tissues should behave similarly regardless of the varying source of cells, thus requiring robust, reproducible and scalable methods of biofabrication that can be achieved using a holistic systems engineering approach. The primary objective of this research proposal is to create models of cardiac and neural human tissues from stem cells that can be used for various purposes to improve the quality of human health.
Statement of Benefit to California: 
California has become internationally renowned as home to the world's most cutting-edge stem cell biology and a global leader of clinical translation and commercialization activities for stem cell technologies and therapies. California has become the focus of worldwide attention due in large part to the significant investment made by the citizens of the state to prioritize innovative stem cell research as a critical step in advancing future biomedical therapies that can significantly improve the quality of life for countless numbers of people suffering from traumatic injuries, congenital disorders and chronic degenerative diseases. At this stage, additional investment in integration of novel tissue engineering principles with fundamental stem cell research will enable the development of novel human tissue constructs that can be used to further the translational use of stem cell-derived tissues for regenerative medicine applications. This proposal would enable the recruitment of a leading biomedical engineer with significant tissue engineering experience to collaborate with leading cardiovascular and neural investigators. The expected result will be development of new approaches to engineer transplantable tissues from pluripotent stem cell sources leading to new regenerative therapies as well as an enhanced understanding of mechanisms regulating human tissue development.

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