The goal of this project is to produce a stem cell-based therapy for stroke (also known as an ischemic cerebral infarct). Stroke is the third leading cause of death in the USA, and a leading cause of disability among adults. Currently, there are no effective treatments once a stroke has occurred (termed completed stroke). In this proposal, we aim to develop human stem cells for therapeutic transplantation to treat stroke. Potential benefits will outweigh risks because only patients with severe strokes that have compromised activities of daily living to an extreme degree will initially be treated. Using a novel approach, we will generate stem cells that do not form tumors, but instead only make new nerve cells. We will give drugs to avoid rejection of the transplanted cells. Thus, the treatment should be safe. We will first test the cells in stroke models in rodents (mice and rats) in preparation for a human clinical trial. We will collect comprehensive data on the mice and rats to determine if the stem cells indeed become new nerve cells to replace the damaged tissue and to assess if the behavior of the mice and rats has improved. If successfully developed and commercialized, this approach has the potential for revolutionizing stroke therapy.
The goal of this project is to produce a stem cell-based therapy for stroke (also known as an ischemic cerebral infarct). Stroke is the third leading cause of death in the State of California, and a leading cause of disability among adults. Currently, there are no effective treatments once a stroke has occurred (termed completed stroke), and the quality of life is severely compromised in those that survive the malady. In this proposal, we aim to develop human stem cells for therapeutic transplantation to treat stroke. Using a novel approach, we will generate stem cells that do not form tumors, but instead only make new nerve cells. If successfully developed and commercialized, this approach could provide a therapeutic candidate for the unmet medical need, which would have a tremendous impact on the quality of life for the patient, his or her family, and for the economic and emotional burden on the State of California and its citizens.
- Stroke is the third leading cause of death in the USA and remains a great medical problem in California. Currently, there is no effective treatment for patients with a stroke who are seen several hours after the event. The goal of this project is to establish the feasibility of using a stem cell line for cell-replacement therapy to target stroke (cerebral ischemia). Using a novel, genetic pre-programming approach, we will generate human neural stem/progenitor cells (hNSC/NPCs) that are resistant to apoptotic cell death and destined to become nerve cells (or neurons). Our approach also avoids tumor formation, which can occur if stem cells that are not programmed to become neurons are injected into the brain. We will achieve our goals by introducing a constitutively active form of the transcription factor MEF2C (MEF2CA) into human embryonic stem cell (hESC)-derived hNPCs. For this purpose it is critical to identify a viral vector system that is the safest and most effective in producing MEF2CA-programmed hNPCs. We decided to use an adenoviral-associated virus (AAV) vector system because unlike other viral delivery methods (e.g., lentiviral, retroviral), an AAV system allows us to achieve MEF2CA expression in an integration-free and transient manner, as required for proper neuronal differentiation from NPCs. After in vitro characterization of these cells, including their neurogenic capacity, scalability etc., we will transplant them into rodent models of focal stroke. We are analyzing transplanted rats with immunohistochemical, electrophysiological, and behavioral methods to determine whether MEF2CA-programmed hNPCs can successfully differentiate into functional, integrated neurons into the host brain and ameliorate stroke-induced behavioral deficits. To assess the robustness of the AAV approach, we will also compare the results obtained from this system to those obtained using a hESC line that is stably programmed (resulting in permanent insertion of the MEF2C transgene into the genome of the cell, as opposed to transient MEF2C expression achieved with the AAV system). These studies will allow us to determine the effectiveness of the integration-free AAV system vs. stable integration of MEF2C on hNPCs developed for cell replacement therapy. During the current reporting period (Year 01), we have efficiently produced an AAV vector that transduces the MEF2CA transgene into hESC-derived NPCs. FACS analysis revealed that we have robustly infected the hNPCs with this AAV-based construct (~95% of cells infected). In vitro evaluation for protein and mRNA (through immunocytochemistry, and qRT-PCR assays) from the cells infected with AAV-MEF2CA revealed their neural progenitor cell identity and that the MEF2CA transgene is active in these cells. We have begun to transplant these cells into the brain of the spontaneously hypertensive (SHR) rat model of focal stroke. We have begun to compare the effects in stroke of the AAV-MEF2CA and stable-MEF2CA cell lines. In vitro characterization of the stable MEF2CA stem cell line demonstrated that we can differentiate these hNPCs into neurons. For example, protein, mRNA, and morphological analyses revealed robust differentiation of these hNPCs into mature cerebrocortical neurons. Electrophysiological analysis further confirmed the expression of functional neuronal channels and synaptic currents. Behavioral evaluation performed 12-weeks after transplant into the stroked brain with the stable-MEF2CA hNPC line vs. control revealed promising behavioral improvements in the MEF2CA-NPC transplanted group compared to control without apparent side effects.
The long-term objective of this project is to develop a drug to treat Huntington’s disease (HD), the most common inherited neurodegenerative disorder. Characterized by involuntary movements, personality changes and dementia, HD is a devastatingly progressive disease that results in death 10–20 years after disease onset and diagnosis. No therapy presently exists for HD; therefore, this project is highly innovative and ultimately aims to deliver something transformative for the HD patient population. The specific goal of the proposed research will be to achieve preclinical proof-of-concept with a novel small molecule that binds to and ameliorates the neurotoxicity of the mutant huntingtin (mHtt) protein that causes HD. Rationale for development of such compounds comes from previous research that found that mHtt assumes a shape that is selectively toxic to neurons, and that small molecules that disrupt this shape can reduce mHtt’s toxicity in primary neurons. Critical to the proposed studies will be assays that employ human striatal neurons derived from adult and juvenile HD patients and generated with induced pluripotent stem cell (iPSC) technology. These HD i-neurons display many characteristics that are also observed in striatal neurons of HD patients, including reduced survival times. They provide the most genetically precise preclinical system available to test for both drug efficacy and safety.
The long-term objective of this project is to develop a first-in-class, disease-modifying drug to treat Huntington’s disease (HD), a devastatingly progressive genetic disorder that results in death 10–20 years after disease onset and diagnosis. No therapy presently exists for HD; therefore, this highly innovative project aims to deliver a medical breakthrough that will provide significant benefit for California’s estimated > 2000 HD patients and the family members, friends and medical system that care for them. The proposed research will be performed at a biotechnology startup, a leading academic research center and two contract research organizations, all of which are California-based. The work will over time involve more than 10 California scientists, thereby helping to employ tax-paying citizens and maintain the State’s advanced technical base. Finally, an effective, proprietary drug for the treatment of HD is expected to be highly valuable and to attract favorable financial terms upon out-licensing for development and commercialization. These revenues would flow to the California companies and institutions (including CIRM) that would have a stake in the proceeds.
- The long-term objective for this project was to develop a first-in-class, disease-modifying drug to treat Huntington's disease (HD). This drug would comprise a small molecule that binds to and ameliorates the neurotoxicity of the mutant huntingtin protein (mHtt) that causes HD.
- The goal of the research conducted under the CIRM Award was to demonstrate development candidate feasibility in vitro with a novel small molecule mHtt detoxifier early lead compound that is potent and efficacious in neurons from HD patients generated using stem cell technology (HD i-neurons) as well as suitable for use in mice as experimental models for HD.
- The original project strategy was to 1) acquire or synthesize new samples of compounds identified as potential mHtt detoxifiers in the screening campaign conducted 7 years ago; 2) establish or re-establish the cell-free and cultured neuron biological assays needed to characterize potential small molecule mHtt detoxifiers (this work was carried out in the laboratory of our collaborator, Dr. Steven Finkbeiner of the J. David Gladstone Institutes); 3) acquire or synthesize new/novel analogs of the initial hits; 4) test new/novel compounds for activity in a cell-free assay for potential mHtt detoxifier activity; 5) test hits for efficacy in HD and non-HD i-neurons; and 6) profile the in vitro and in vivo pharmacokinetics and absorption, distribution, metabolism and elimination (PK/ADME) profiles of compounds that displayed selective neuroprotection toward HD i-neurons.
- Specific achievements of the first year of the Project include:
- • Acquiring 205 previously identified hits or analogs thereof from commercial sources;
- • Synthesizing an additional 84 novel, designed analogs;
- • Generating the reagents, re-establishing and implementing the screening assay;
- • Testing all compounds acquired or synthesized in the screening assay;
- • Establishing a counterscreen for false positives in the screening assay;
- • Preliminary screening 48 previously reported hits in the counterscreen;
- • Testing 14 previously or newly identified hits side-by-side in full concentration-response assays in both the screening and counterscreening assays;
- • Profiling 11 diverse hits in in vitro PK/ADME assays;
- • Testing 17 compounds for their ability to ameliorate neurotoxicity in a rodent primary neuron model; and
- • Preliminary testing 2 previously identified hits in human HD i-neurons.
- Unfortunately and surprisingly, we observed that all compounds displayed essentially identical profiles in full concentration-response studies in both the screening and counterscreening assays. We interpret this result to indicate that these compounds and structurally related compounds that we considered to be most promising and tested do not in fact bind to mHtt, i.e., they are all false positives. Since no valid starting points exist for continued work, the Project will be terminated after the first award period.
Critical to the long term success of the CIRM iPSC Initiative of generating and ensuring the availability of high quality disease-specific human IPSC lines is the establishment and successful operation of a biorepository with proven methods for quality control, safe storage and capabilities for worldwide distribution of high quality, highly-characterized iPSCs. Specifically the biorepository will be responsible for receipt, expansion, quality characterization, safe storage and distribution of human pluripotent stem cells generated by the CIRM stem cell initiative. This biobanking resource will ensure the availability of the highest quality hiPSC resources for researchers to use in disease modeling, target discovery and drug discovery and development for prevalent, genetically complex diseases.
The generation of induced pluripotent stem cells (iPSCs) from patients and subsequently, the ability to differentiate these iPSCs into disease-relevant cell types holds great promise in facilitating the “disease-in-a-dish” approach for studying our understanding of the pathological mechanisms of human disease. iPSCs have already proven to be a useful model for several monogenic diseases such as Parkinson’s, Fragile X Syndrome, Schizophrenia, Spinal Muscular Atrophy, and inherited metabolic diseases such as 1-antitrypsin deficiency, familial hypercholesterolemia, and glycogen storage disease. In addition, the differentiated cells obtained from iPSCs represent a renewable, disease-relevant cell model for high-throughput drug screening and toxicology/safety assessment which will ultimately lead to the successful development of new therapeutic agents. iPSCs also hold great hope for advancing the use of live cells as therapies for correcting the physiological manifestations caused by disease or injury.
- The California Institute for Regenerative Medicine (CIRM) Human Pluripotent Stem Cell Biorepository is operated by the Coriell Institute for Medical Research and is a critical component of the CIRM Human Stem Cell Initiative. The overall goal of this initiative is to generate, for world-wide use by non-profit and for-profit entities, high quality, disease-specific induced pluripotent stem cells (iPSCs). These cells are derived from existing tissues such as blood or skin, and are genetically manipulated in the laboratory to change into cells that resemble embryonic stem cells. iPSCs can be grown indefinitely in the Petri dish and have the remarkable capability to be converted into most of the major cell types in the body including neurons, heart cells, and liver cells. This ability makes iPSCs an exceptional resource for disease modeling as well as for drug screening. The expectation is that these cells will be a major benefit to the process for understanding prevalent, genetically complex diseases and in developing innovative therapeutics.
- The Coriell CIRM iPSC Biorepository, located at the Buck Institute for Research on Aging in Novato, CA, is funded through a competitive grant award to Coriell from CIRM and is managed by Mr. Matt Self under the supervision of the Program Director, Dr. Steven Madore, Director of Molecular Biology at Coriell. The Biorepository will receive biospecimens consisting of peripheral blood mononuclear cells (PBMCs) and skin biopsies obtained from donors recruited by seven Tissue Collector grant awardees. These biospecimens will serve as the starting material for iPSC derivation by Cellular Dynamics, Inc (CDI). Under a contractual agreement with Coriell, CDI will expand each iPSC line to generate sufficient aliquots of high quality cryopreserved cells for distribution via the Coriell on-line catalogue. Aliquots of frozen cell lines and iPSCs will be stored in liquid nitrogen vapor in storage units at the Buck Institute with back-up aliquots stored in a safe off-site location.
- Renovation and construction of the Biorepository began at the Buck Institute in late January. The Biorepository Manger was hired March 1 and after installation of cryogenic storage vessels and alarm validation, the first biospecimens were received on April 30, 2014. Additionally, Coriell has developed a Clinical Information Management System (CIMS) for storing all clinical and demographic data associated with enrolled subjects. Tissue Collectors utilize CIMS via a web interface to upload and edit the subject demographic and clinical information that will ultimately be made available, along with the iPSCs, via Coriell’s on-line catalogue
- As of November 1 specimens representing a total of 725 unique individuals have been received at the Biorepository. These samples include PBMCs obtained from 550 unique individuals, skin biopsies from 72 unique individuals, and 103 primary dermal fibroblast cultures previously prepared in the laboratories of the CIRM Tissue Collectors. A total of 280 biospecimen samples have been delivered to CDI for the purpose of iPSC derivation. The Biorepository is anticipating delivery of the first batches of iPSCs for distribution in early 2015. These lines, along with the associated clinical data, will become available to scientists via the on-line Coriell catalogue. The CIRM Coriell iPSC Biorepository will ensure safe long-term storage and distribution of high quality iPSCs.
Induced pluripotent stem cells (iPSCs) have the potential to differentiate to nearly any cells of the body, thereby providing a new paradigm for studying normal and aberrant biological networks in nearly all stages of development. Donor-specific iPSCs and differentiated cells made from them can be used for basic and applied research, for developing better disease models, and for regenerative medicine involving novel cell therapies and tissue engineering platforms. When iPSCs are derived from a disease-carrying donor; the iPSC-derived differentiated cells may show the same disease phenotype as the donor, producing a very valuable cell type as a disease model. To facilitate wider access to large numbers of iPSCs in order to develop cures for polygenic diseases, we will use a an episomal reprogramming system to produce 3 well-characterized iPSC lines from each of 3,000 selected donors. These donors may express traits related to Alzheimer’s disease, autism spectrum disorders, autoimmune diseases, cardiovascular diseases, cerebral palsy, diabetes, or respiratory diseases. The footprint-free iPSCs will be derived from donor peripheral blood or skin biopsies. iPSCs made by this method have been thoroughly tested, routinely grown at large scale, and differentiated to produce cardiomyocytes, neurons, hepatocytes, and endothelial cells. The 9,000 iPSC lines developed in this proposal will be made widely available to stem cell researchers studying these often intractable diseases.
Induced pluripotent stem cells (iPSCs) offer great promise to the large number of Californians suffering from often intractable polygenic diseases such as Alzheimer’s disease, autism spectrum disorders, autoimmune and cardiovascular diseases, diabetes, and respiratory disease. iPSCs can be generated from numerous adult tissues, including blood or skin, in 4–5 weeks and then differentiated to almost any desired terminal cell type. When iPSCs are derived from a disease-carrying donor, the iPSC-derived differentiated cells may show the same disease phenotype as the donor. In these cases, the cells will be useful for understanding disease biology and for screening drug candidates, and California researchers will benefit from access to a large, genetically diverse iPSC bank. The goal of this project is to reprogram 3,000 tissue samples from patients who have been diagnosed with various complex diseases and from healthy controls. These tissue samples will be used to generate fully characterized, high-quality iPSC lines that will be banked and made readily available to researchers for basic and clinical research. These efforts will ultimately lead to better medicines and/or cellular therapies to treat afflicted Californians. As iPSC research progresses to commercial development and clinical applications, more and more California patients will benefit and a substantial number of new jobs will be created in the state.
- First year progress on grant ID1-06557, " Generation and Characterization of High-Quality, Footprint-Free Human Induced Pluripotent Stem Cell (iPSC) Lines From 3000 Donors to Investigate Multigenic Disease" has met all agreed-upon milestones. In particular, Cellular Dynamics International (CDI) has taken lease to approximately 5000 square feet of lab space at the Buck Institute for Research on Aging in Novato, CA. The majority of this space is located within the new CIRM-funded Stem Cell Research Building at the Buck Institute and was extensively reconfigured to meet the specific needs of this grant. All equipment, including tissue culture safety cabinets and incubators, liquid-handling robotics, and QC instrumentation have been installed and qualified. A total of 16 scientists have been hired and trained (13 in Production and 3 in Quality) and more than 20 Standard Operating Procedures (SOPs) have been developed and approved specifically for this project. These SOPs serve to govern the daily activities of the Production and Quality staff and help ensure consistency and quality throughout the iPSC derivation and characterization process. In addition, a Laboratory Information Management System (LIMS) had to be developed to handle the large amount of data generated by this project and to track all samples from start to finish. The first and most important phase of this LIMS project has been completed; additional functionalities will likely be added to the LIMS during the next year, but completion of phase 1 will allow us to enter full production mode on schedule in the first quarter of year 2. Procedures for the shipping, infectious disease testing, and processing of donor samples were successfully implemented with the seven Tissue Collectors. To date, over 700 samples have been received from these Tissue Collectors and derivation of the first 50 patient-derived iPSC lines has been completed on schedule. These cells have been banked in the Coriell BioRepository, also located at the Buck Institute. The first Distribution Banks will be available for commercial release during year 2.
Alzheimer's Disease (AD), the most common form of dementia in the elderly, affects over 5 million Americans. There are no treatments to slow progression or prevent AD. This reflects limitations in knowledge of mechanisms underlying AD, and in tools and models for early development and testing of treatment. Genetic breakthroughs related to early onset AD led to initial treatment targets related to a protein called amyloid, but clinical trials have been negative. Extensive research links genetic risk to AD, even when the age at onset is after the age of 65. AD affects the brain alone, therefore studying authentic nerve cells in the laboratory should provide the clearest insights into mechanisms and targets for treatment. This has recently become feasible due to advances in programming skin cells into stem cells and then growing (differentiating) them into nerve cells. In this project we will obtain skin biopsies from a total of 220 people with AD and 120 controls, who are extensively studied at the [REDACTED] AD Research Center. These studies include detailed genetic (DNA) analysis, which will allow genetic risks to be mapped onto reprogrammed cells. These derived cells that preserve the genetic background of the person who donated the skin biopsy will be made available to the research community, and have the promise to accelerate studies of mechanisms of disease, understanding genetic risk, new treatment targets, and screening of new treatments for this devastating brain disorder.
The proposed project will provide a unique and valuable research resource, which will be stored and managed in California. This resource will consist of skin cells or similar biological samples, suitable for reprogramming, obtained from well-characterized patients with Alzheimer's Disease and cognitively healthy elderly controls. Its immediate impact will be to benefit CIRM-funded researchers as well as the greater research community, by providing them access to critical tools to study, namely nerve cells that can be grown in a dish (cultured) that retain the genetic background of the skin cell donors. This technology to develop and reprogram cells into nerve cells or other cell types results from breakthroughs in stem cell research, many of which were developed using CIRM funding. Alzheimer's Disease affects over 600,000 Californians, and lacks effective treatment. Research into mechanisms of disease, identifying treatment targets, and screening novel drugs will be greatly improved and accelerated through the availability of the resources developed by this project, which could have a major impact on the heath of Californians. California is home to world class academic and private research institutes, Biotechnology and Pharmaceutical Companies, many of whom are already engaged in AD research. This project could provide them with tools to make research breakthroughs and pioneer the development of novel treatments for AD.
- We have completed startup procedures, including obtaining approval for human subjects research, and making logistical arrangements for the study. We have carried out publicity efforts for the study, including giving presentations at health fairs and senior centers. We have recruited 4 subjects as of October 1, 2014. Now that procedures are in place, we are ready to accelerate recruitment. The goals of the study are to obtain blood or skin biopsy samples from well-characterized people with Alzheimer's disease and from healthy elderly controls, to have these samples reprogrammed into nerve cells, which will support research.
- We have continued to collect blood samples from patients with Alzheimer's disease, of varying age at onset, as well as well-characterized elderly controls. These will be used for reprogramming into pluripotent stem cells. Those can then be reprogrammed into other types of mature cells such as nerve cells or neurons. these can be used for research to understand mechanisms of aging, Alzheimer's disease, and other disorders. The mechanisms of Alzheimer's disease are incompletely understood. It is not possible to study nerve cells from patients with Alzheimer's disease during life. Using stem cell technology enables such studies to occur.
Most children who go to the clinic with brain disorders have symptoms combining autism, cerebral palsy and epilepsy, suggesting underlying and shared mechanisms of brain dysfunction in these conditions. Such disorders affect 4-6% of the population with life-long disease, and account for about 10% of health care expenditures in the US. Genetic studies have pointed to frequent low-penetrant or low-frequency genetic alterations, but there is no clear way to use this information to make gene-specific diagnosis, to predict short- or long-term prognosis or to develop disease-specific therapy. We propose to recruit about 500 patients with these disorders mostly from our Children’s Hospital, through a dedicated on-site collaborative approach. Extracting from existing medical records, taking advantage of years of experience in recruitment and stem cell generation, and already existing or planned whole exome or genome sequencing on most patients, we propose a safe, anonymous database linked to meaningful biological, medical, radiographic and genetic data. Because team members will be at the hospital, we can adjust future disease-specific recruitment goals depending upon scientific priorities, and re-contact patients if necessary. The clinical data, coupled with the proposed hiPSC lines, represents a platform for cell-based disease investigation and therapeutic discovery, with benefits to the children of California.
This project can benefit Californians both in financial and non-financial terms. NeuroDevelopmental Disabilities (NDDs) affect 4-6% of Californians, create a huge disease burden estimated to account for 10% of California health care costs, and have no definitive treatments. Because we cannot study brain tissue directly, it is extraordinarily difficult to arrive at a specific diagnosis for affected children, so doctors are left ordering costly and low-yield tests, which limit prognostic information, counseling, prevention strategies, quality of life, and impede initiation of potentially beneficial therapies. Easily obtainable skin cells from Californians will be the basis of this project, so the study results will have maximal relevance to our own population. By combining “disease in a dish” platforms with cutting edge genomics, we can improve diagnosis and treatments for Californians and their families suffering from neurodevelopmental disorders.
Additionally, this project, more than others, will help Californians financially because: 1] The ongoing evaluations of this group of patients utilizes medical diagnostics and genetic sequencing tools developed and manufactured in California, increasing our state revenues. 2] The strategy to develop “disease in a dish” projects centered on Neurodevelopmental Disabilities supports opportunities for ongoing efforts of California-based pharmaceutical and life sciences companies to leverage these discoveries for future therapies.
- Childhood Neurodevelopmental Disabilities (NDDs) affect approximately 12% of children in the US, and account for >5% of total healthcare costs. The ability to use induced pluripotent stem cells (iPSCs) to incorporate characteristics of patient cells into models that predict patient disease characteristics and clinical outcomes can have a major impact on care for the children with these conditions. We have proposed to ascertain pediatric patient samples which represent a range of NDDs including Autism Spectrum Disorders (ASD), Intellectual Disability (ID), Cerebral Palsy (CP) and Epilepsy for iPSC banking. These disorders were chosen because they have high heritability rates but remain genetically complex, and therefore, will greatly benefit from further in-depth study using iPSCs
- To date we have enrolled 128 patients (72 affected patients, 56 healthy control patients) representing a range of racial and ethnic backgrounds (39% White, 2% Black, 2% Asian, 57% Arabic/Middle Eastern) and both genders (52% Male, 48% Female). The patients in the affected patient group carry a primary diagnosis of one of the NDD disease categories (19% Autism Spectrum Disorder, 44% Epilepsy, 28% Intellectual Disability, 9% Cerebral Palsy). Approximately half of the patients are comorbid for one or more of the other disorders. The control patients consist of healthy family members of the affected patient group. Since family members share many common DNA features this will help us better identify and hone in on disease causing variants more effectively.
- iPSC lines have not yet been returned from these patients so there are no research results to report at this time. We are continuing with our recruitment efforts to reach our goal of 450 affected patients and 100 healthy controls.
Autism spectrum disorders (ASD) are a family of disabling disorders of the developing brain that affect about 1% of the population. Studying the biology of these conditions has been difficult as they have been challenging to represent in animal models. The core symptoms of ASD, including deficits in social communication, imagination and curiosity are intrinsically human and difficult to model in organisms commonly studied in the laboratory. Ideally, the mechanisms underlying ASDs need to be studied in human patients and in their cells. Since they maintain the genetic profile of an individual, studying neurons derived from human induced pluripotent stem cells (hiPSC) is attractive as a method for studying neurons from ASD patients. hiPSC based studies of ASDs hold promise to uncover deficits in cellular development and function, to evaluate susceptibility to environmental insults, and for screening of novel therapeutics. In this project our goal is to contribute blood and skin samples for hiPSC research from 200 children with an ASD and 100 control subjects to the CIRM repository. To maximize the value of the collected tissue, all subjects will have undergone comprehensive clinical evaluation of their ASD. The cells collected through this project will be made available to the wider research community and should result in a resource that will enable research on hiPSC-derived neurons on a scale and depth that is unmatched anywhere else in the world.
The prevalence and impact of Autism Spectrum Disorders (ASD) in California is staggering. California has experienced 13% new ASD cases each year since 2002. ASD are a highly heritable family of complex neurodevelopmental conditions affecting the brain, with core symptoms of impaired social skills, language, behavior and intellectual abilities. The majority with an ASD experience lifelong disability that requires intensive parental, school, and social support. The result has been a 12-fold increase in the number of people receiving ASD services in California since 1987, with over 50,000 people with ASDs served by developmental and regional centers. Within the school system, the number of special education students with ASD in California has more than tripled between 2002 and 2010. The economic, social and psychological toll is enormous.
It is critical to both prevent and develop effective treatments for ASD. While rare genetic mutations account for a minority of cases, our understanding of idiopathic ASD (>85% of cases) is extremely limited. Mechanisms underlying ASDs need to be studied in human patients and in cells that share the genetic background of these patients. Since they maintain the complete genetic background of an individual, hiPSCs represent a very practical and direct method for investigating neurons from ASD patients to uncover cellular deficits in their development and function, and for screening of novel therapeutics.
- Autism Spectrum Disorders (ASD) have a worldwide prevalence of 1% (>1.5 million in the US) and a lifetime cost per affected individual of $3.2M. ASDs are amongst the most heritable of psychiatric disorders. Genome Wide Association studies utilizing samples in the thousands provide only weak evidence for common allele risk effects; positive findings rarely replicate, and genetic effects sizes are small (odds ratios of ~1.1). In contrast, evidence to date for risk or causation conferred by rare variation, particularly rare copy number variants, is very strong. Pathway analyses of the rare mutations implicated and genome-wide transcriptome analysis of brain and blood tissue provide converging evidence that neural-related pathways are central to the development of autism. Core impairments of ASDs, such as imagination and curiosity about the environment, cannot be modeled well in other organisms. The mechanisms underlying ASDs need to be studied in humans and cells that share the genetic background of the patients, such as neurons from patients derived from induced pluripotent cell lines (iPSC).
- Our goal was to provide the CIRM repository with samples from 200 well characterized individuals with an ASD and 100 demographically matched controls. To date we have enrolled 63 participants.
- The goal of the project is to recruit 200 individuals with an autism spectrum disorder (ASD) and 100 demographically matched controls for derivation of induced pluripotent stem cells (iPSCs). The cells will be deposited in a biorepository and made available to other researchers upon request.. ASDs have a worldwide prevalence of 1% (>1.5 million in the US) and a lifetime cost per affected individual of $3.2M. ASDs are amongst the most heritable of psychiatric disorders. Genome Wide Association studies utilizing samples in the thousands provide only weak evidence for common allele risk effects; positive findings rarely replicate, and genetic effects sizes are small (odds ratios of ~1.1). In contrast, evidence to date for risk or causation conferred by rare variation, particularly rare copy number variants, is very strong. Pathway analyses of the rare mutations implicated and genome-wide transcriptome analysis of brain and blood tissue provide converging evidence that neural-related pathways are central to the development of autism. Core impairments of ASDs, such as imagination and curiosity about the environment, cannot be modeled well in other organisms. The mechanisms underlying ASDs need to be studied in humans and cells that share the genetic background of the patients, such as neurons from patients derived from induced pluripotent cell lines (iPSC). Recruitment of participants occurred through the Autism and Developmental Disabilities Clinic (ADDC) at Stanford University, direct referrals to investigators, through the Stanford autism research registry, from completed and ongoing research studies, and through advertisement on the web and print. To date we have recruited 181 subjects of the 300 total.
The applicant is an MD/PhD trained physician scientist, whose clinical expertise is neuromuscular disorders including peripheral nerve disease. The proposal is aimed at providing a research proposal and career development plan that will allow the applicant to develop an independent research program, which attempts to bring stem cell based therapies to patients with peripheral nerve diseases. The proposal will use “adult stem cells” derived from patients with an inherited nerve disease, correct the genetic abnormality in those cells, and determine the feasibility of transplanting the genetically engineered cells back into peripheral nerve to slow disease progression.
The proposed research will benefit the State of California as it will support the career development of a uniquely trained physician scientist to establish an innovative translational stem cell research program aimed toward direct clinical application to patients. The cutting edge technologies proposed are directly in line with the fundamental purpose of the California Initiative for Regenerative Medicine. If successful, both scientific and patient advocate organizations would recognize that these advances came directly from the unique efforts of CIRM and the State of California to lead the world in stem cell research. Finally, as a result of funding of this award, further financial investments from private and public funding organizations would directly benefit the State in the years to come.
- During this award period we have made significant progress. We have established induced pluripotent stem cell (iPSC) lines from four patients with Charcot-Marie-Tooth disease type 1A (CMT1A) due to the PMP22 duplication. We have validated our strategy to genetically engineer induced pluripotent stem cells from patients with inherited neuropathy, and have genetically engineered several patient lines. We further have begun to differentiate these iPSCs into Schwann cell precursors, to begin to investigate cell type specific defects that cause peripheral neurodegeneration in patients with CMT1A. Finally we have imported and characterized a transgenic rat model of CMT1A in order to begin to investigate the ability to inject iPSC derived Schwann cell precursors into rodent nerves as a possible neuroprotective strategy.
- During this reporting period we developed genetically corrected induced pluripotent stem cell lines from patients with CMT1A. We improved and validated a novel method for differentiating Schwann cells from iPSCs, and used this to generate human Schwann cells from patients and controls. Finally we have initiated pilot studies injecting human iPSC derived Schwann cells into the peripheral nerves of rats with myelin diseases to determine whether cell replacement therapy is a viable strategy in these disorders.
Chemotherapy for cancer is often life saving, but it also causes a debilitating syndrome of impaired cognition characterized by deficits in attention, concentration, information processing speed, multitasking and memory. As a result, many cancer survivors find themselves unable to return to work or function in their lives as they had before their cancer therapy. These cognitive deficits, colloquially known as "chemobrain" or "chemofog," are long-lasting and sometimes irreversible. For example, breast cancer survivors treated with chemotherapy suffer from cognitive disability even 20 years later.
These cognitive problems occur because chemotherapy damages the neural stem and precursor cells necessary for the health of the brain's infrastructure, called white matter. We have discovered a powerful way to recruit the stem/precursor cells required for white matter repair that depends on an interaction between the electrical cells of the brain, neurons, and these white matter stem/precursor cells. In this project, we will determine the key molecules responsible for the regenerative influence of neurons on these white matter stem cells and will develop that molecule (or molecules) into a drug to treat chemotherapy-induced cognitive dysfunction. If successful, this will result in the first effective treatment for a disease that affects at least a million cancer survivors in California.
Approximately 100,000 Californians are diagnosed with cancer each year, and the majority of these people require chemotherapy. While cancer chemotherapy is often life saving, it also causes a debilitating neurocognitive syndrome characterized by impaired attention, concentration, information processing speed, multitasking and memory. As a result, many cancer survivors find themselves unable to return to work or function in their lives as they had before their cancer therapy. These cognitive deficits, colloquially known as "chemobrain" or "chemofog" are long-lasting; for example, cognitive deficits have been demonstrated in breast cancer survivors treated with chemotherapy even 20 years later. With increasing cancer survival rates, the number of people living with cognitive disability from chemotherapy is growing and includes well over a million Californians. Presently, there is no known therapy for chemotherapy-induced cognitive decline, and physicians can only offer symptomatic treatment with medications such as psychostimulants.
The underlying cause of "chemobrain" is damage to neural stem and precursor cell populations. The proposed project may result in an effective regenerative strategy to restore damaged neural precursor cell populations and ameliorate or cure the cognitive syndrome caused by chemotherapy. The benefit to California in terms of improved quality of life for cancer survivors and restored occupational productivity would be immeasurable.
- Cancer chemotherapy can be lifesaving but frequently results in long-term cognitive deficits. This project seeks to establish a regenerative strategy for chemotherapy-induced cognitive dysfunction by harnessing the potential of the interactions between active neurons and glial precursor cells that promote myelin plasticity in the healthy brain. In the first year of this award, we have made on-track progress towards establishing a working experimental model system of chemotherapy-induced neurotoxicity that faithfully models the human disease both in terms of the cellular damage as well as functional deficits in cognition. We have also been able to identify several therapeutic candidate molecules that we will be studying in the coming years of the project to ascertain which of these candidates are sufficient to promote OPC population repletion and neuro-regeneration after chemotherapy exposure.
- Cancer chemotherapy can be lifesaving but frequently results in long-term cognitive deficits. This project seeks to establish a regenerative strategy for chemotherapy-induced cognitive dysfunction by harnessing the potential of the interactions between active neurons and glial precursor cells that promote myelin plasticity in the healthy brain. In the first year of this award, we have made on-track progress towards establishing a working experimental model system of chemotherapy-induced neurotoxicity that faithfully models the human disease both in terms of the cellular damage as well as functional deficits in cognition. Using this model, we have found that the oligodendroglial precursor cell population depletion following chemotherapy is due not only to a direct effect of the chemotherapy on the OPCs, but also due to alterations in the microenvironmental milieu of the brain that normally maintains this population of cells. We have also been able to identify several therapeutic candidate molecules that we will be studying in the coming years of the project to ascertain which of these candidates are sufficient to promote OPC population repletion and neuro-regeneration after chemotherapy exposure.
White matter is the infrastructure of the brain, providing conduits for communication between neural regions. White matter continues to mature from birth until early adulthood, particularly in regions of brain critical for higher cognitive functions. However, the precise timing of white matter maturation in the various neural circuits is not well described, and the mechanisms controlling white matter developmental/maturation are poorly understood. White matter is conceptually like wires and their insulating sheath is a substance called myelin. It is clear that neural stem and precursor cells contribute significantly to white matter maturation by forming the cells that generate myelin. In the proposed experiments, we will map the precise timing of myelination in the human brain and changes in the populations of neural precursor cells that generate myelin from birth to adulthood and define mechanisms that govern the process of white matter maturation. The resulting findings about how white matter develops may provide insights for white matter regeneration to aid in therapy for diseases such as cerebral palsy, multiple sclerosis and chemotherapy-induced cognitive dysfunction.
Diseases of white matter account for significant neurological morbidity in both children and adults in California. Understanding the cellular and molecular mechanisms that govern white matter development the may unlock clues to the regenerative potential of endogeneous stem and precursor cells in the childhood and adult brain. Although the brain continues robust white matter development throughout childhood, adolescence and young adulthood, relatively little is known about the mechanisms that orchestrate proliferation, differentiation and functional maturation of neural stem and precursor cells to generate myelin-forming oligodendrocytes during postnatal brain development. In the present proposal, we will define how white matter precursor cell populations vary with age throughout the brain and determine if and how neuronal activity instructs neural stem and precursor cell contributions to human white matter myelin maturation.
Disruption of white matter myelination is implicated in a range of neurological diseases, including cerebral palsy, multiple sclerosis, cognitive dysfunction from chemotherapy exposure, attention deficit and hyperactivity disorder (ADHD) and even psychiatric diseases such as schizophrenia. The results of these studies have the potential to elucidate clues to white matter regeneration that may benefit hundreds of thousands of Californians.
- Formation of the insulated fiber infrastructure of the human brain (called "myelin") depends upon the function of a precursor cell type called "oligodendrocyte precursor cells (OPC)". The first Aim of this study seeks to determine how OPCs differ from each other in different regions of the brain, and over different ages. Understanding this heterogeneity is important as we explore the regenerative capacity of this class of precursor cells. We have, in the past year, isolated OPCs from various regions of the human brain from individuals at various ages and are studying the molecular characteristics of these precursor cells at the single cell level in order to define distinct OPC subpopulations. We have also begun to study the functional capabilities of OPCs isolated from different brain regions. The second Aim of this study seeks to understand how interactions between electrically active neurons and OPCs affect OPC function and myelin formation. We have found that when mouse motor cortex neurons "fire" signals in such a way as to elicit a complex motor behavior, much as would happen when one practices a motor task, OPCs within that circuit respond and myelination increases. This affects the function of that circuit in a lasting way. These results indicate that neurons and OPCs interact in important ways to modulate myelination and supports the hypothesis that OPC function may play a role in learning.
- Sending neural impulses quickly down a long nerve fiber requires a specialized type of insulation called myelin, made by a cell called an oligodendrocyte that wraps itself around neuronal projections. Myelin-insulated nerve fibers make up the “white matter” of the brain, the vast tracts that connect one information-processing area of the brain to another. We have now shown that neuronal activity prompts oligodendrocyte precursor cell (OPC) proliferation and differentiation into myelin-forming oligodendrocytes. Neuronal activity also causes an increase in the thickness of the myelin sheaths within the active neural circuit, making signal transmission along the neural fiber more efficient. This was found to be true in both juvenile and in adult brains Metaphorically, it’s much like a system for improving traffic flow along roadways that are heavily used. And as with a transportation system, improving the routes that are most productive makes the whole system more efficient.
- Interestingly, some parts of the neural circuit studied showed evidence of myelin-forming precursor cell response to neuronal activity, while other parts of the active circuit did not. In related work, we are making progress towards understanding how OPCs differ in various regions of the brain, examining the molecular heterogeneity of human OPCs at a single cell level.