Neurological Disorders

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

Developing a drug-screening system for Autism Spectrum Disorders using human neurons

Funding Type: 
Early Translational II
Grant Number: 
TR2-01814
ICOC Funds Committed: 
$1 491 471
Disease Focus: 
Autism
Neurological Disorders
Pediatrics
Stem Cell Use: 
iPS Cell
Cell Line Generation: 
iPS Cell
oldStatus: 
Active
Public Abstract: 
Autism and autism spectrum disorders (ASD) are complex neurodevelopmental diseases that affect 1 in 150 children in the United States. Such diseases are mainly characterized by deficits in verbal communication, impaired social interaction, and limited and repetitive interests and behavior. Because autism is a complex spectrum of disorders, a different combination of genetic mutations is likely to play a role in each individual. One of the major impediments to ASD research is the lack of relevant human disease models. ASD animal models are limited and cannot reproduce the important language and social behavior impairment of ASD patients. Moreover, mouse models do not represent the vast human genetic variation. Reprogramming of somatic cells to a pluripotent state (induced pluripotent stem cells, iPSCs) has been accomplished using human cells. Isogenic pluripotent cells are attractive from the prospective to understanding complex diseases, such as ASD. Our preliminary data provide evidence for an unexplored developmental window in ASD wherein potential therapies could be successfully employed. The model recapitulates early stages of ASD and represents a promising cellular tool for drug screening, diagnosis and personalized treatment. By testing whether drugs have differential effects in iPSC-derived neurons from different ASD backgrounds, we can begin to unravel how genetic variation in ASD dictates responses to different drugs or modulation of different pathways. If we succeed, we may find new molecular mechanisms in ASD and new compounds that may interfere and rescue these pathways. The impact of this approach is significant, since it will help better design and anticipate results for translational medicine. Moreover, the collection and molecular/cellular characterization of these iPSCs will be an extremely valuable tool to understand the fundamental mechanism behind ASD. The current proposal uses human somatic cells converted into iPSC-derived neurons. The proposed experiments bring our analyses to real human cell models for the first time. We anticipate gaining insights into the causal molecular mechanisms of ASD and to discover potential biomarkers and specific therapeutic targets for ASD.
Statement of Benefit to California: 
Autism spectrum disorders, including Rett syndrome, Angelman syndrome, Timothy syndrome, Fragile X syndrome, Tuberous sclerosis, Asperger syndrome or childhood disintegrative disorder, affect many Californian children. In the absence of a functionally effective cure or early diagnostic tool, the cost of caring for patients with such pediatric diseases is high, in addition to a major personal and family impact since childhood. The strikingly high prevalence of ASD, dramatically increasing over the past years, has led to the emotional view that ASD can be traced to a single source, such as vaccine, preservatives or other environmental factors. Such perspective has a negative impact on science and society in general. Our major goal is to develop a drug-screening platform to rescue deficiencies showed from neurons derived from induced pluripotent stem cells generated from patients with ASD. If successful, our model will bring novel insights on the dentification of potential diagnostics for early detection of ASD risk, or ability to predict severity of particular symptoms. In addition, the development of this type of pharmacological therapeutic approach in California will serve as an important proof of principle and stimulate the formation of businesses that seek to develop these types of therapies (providing banks of inducible pluripotent stem cells) in California with consequent economic benefit.
Progress Report: 
  • During the first year of the project, we focused on creating a cell bank of reprogrammed fibroblasts derived from several autistic patients. These pluripotent stem cells were then induced to differentiate into neurons and gene expression analyses will be done at different time points along the process. We also used some of the syndromic and non-syndromic patients for neuronal phenotypic assays and found that a subset of idiopathic autism cases displayed a molecular overlap with Rett syndrome. Our plan is to use these data to test the ability of candidate drugs on reverting some of the neuronal defects observed in patient neurons.
  • The goal of this CIRM translational award is to generate a hiPSC-based drug-screening platform to identify potential therapies or biomarkers for autism spectrum disorders. In this second year we have made significant progress toward this goal by working on validating several neuronal phenotypes derived from iPSCs from idiopathic and syndromic autistic patients. We also made significant progress in order to optimize a synaptic readout for the screening platform. This step was important to speed up drug discovery. Using Rett syndrome iPSC-derived neurons as a prototype, we showed that we could rescue defect in synaptogenesis using a collection of FDA-approved drugs. Finally, we have initiated our analyses on global gene expression, from several neurons and progenitor cells derived from controls and autistic patients. We expect to find pathways that are altered in subgroups of patients, defined by specific clinical phenotypes.
  • The goal of this CIRM translational award is to generate a hiPSC-based drug-screening platform to identify potential therapies or biomarkers for ASDs. We have made significant progress toward this goal by working on validating several neuronal phenotypes derived from iPSC from Rett syndrome (RTT) and idiopathic autistic patients. We also made significant progress to optimize the readout for our screening platform. This was important to speed up drug discovery. Using RTT iPSC as a prototype, we showed that we could rescue defect in synaptogenesis using a collection of FDA-approved drugs. Finally, we initiate our analyses on gene expression, collected from several neurons and progenitor cells derived from controls and autistic patients. We expect to find pathways that are altered in subgroups of patients, defined by specific clinical phenotypes. Here, we describe the results of our drug screening, using FDA-approved drugs in a repurposing strategy. We also show for the first time that iPSC-derived human neurons are able to generate synchronized neuronal networks. RTT neurons behave differently from controls. Our focus now is on the completion of our gene expression analyses and to validate positive drugs using a battery of secondary cellular assays.
  • The goal of this CIRM translational award is to generate a hiPSC-based drug-screening platform to identify potential therapies or biomarkers for ASDs. We have made significant progress toward this goal by working on validating several neuronal phenotypes derived from iPSC from Rett syndrome (RTT) and idiopathic autistic patients. We also made significant progress to optimize the synaptogenesis readout for our screening platform. This was important to speed up drug discovery. Using RTT iPSC as a prototype, we showed that we could rescue defect in synaptogenesis using a collection of FDA-approved drugs. We also show for the first time that iPSC-derived human neurons are able to generate synchronized neuronal networks using a multi-electrode array approach. We showed that RTT and ASD neurons behave differently from controls and defects in synchronization can be rescued with candidate drugs. Finally, we concluded our analyses on gene expression, collected from several neurons and progenitor cells derived from controls and autistic patients. We revealed and validated pathways that are altered in ASD patients, defined by specific clinical phenotypes (macrencephaly).

Enhancing healing via Wnt-protein mediated activation of endogenous stem cells

Funding Type: 
Early Translational I
Grant Number: 
TR1-01249
ICOC Funds Committed: 
$6 762 954
Disease Focus: 
Bone or Cartilage Disease
Stroke
Neurological Disorders
Heart Disease
Neurological Disorders
Skin Disease
Stem Cell Use: 
Adult Stem Cell
oldStatus: 
Active
Public Abstract: 
All adult tissues contain stem cells. Some tissues, like bone marrow and skin, harbor more adult stem cells; other tissues, like muscle, have fewer. When a tissue or organ is injured these stem cells possess a remarkable ability to divide and multiply. In the end, the ability of a tissue to repair itself seems to depend on how many stem cells reside in a particular tissue, and the state of those stem cells. For example, stress, disease, and aging all diminish the capacity of adult stem cells to self-renew and to proliferate, which in turn hinders tissue regeneration. Our strategy is to commandeer the molecular machinery responsible for adult stem cell self-renewal and proliferation and by doing so, stimulate the endogenous program of tissue regeneration. This approach takes advantage of the solution that Nature itself developed for repairing damaged or diseased tissues, and controls adult stem cell proliferation in a localized, highly controlled fashion. This strategy circumvents the immunological, medical, and ethical hurdles that exist when exogenous stem cells are introduced into a human. When utilizing this strategy the goal of reaching clinical trials in human patients within 5 years becomes realistic. Specifically, we will target the growing problem of neurologic, musculoskeletal, cardiovascular, and wound healing diseases by local delivery of a protein that promotes the body’s inherent ability to repair and regenerate tissues. We have evidence that this class of proteins, when delivered locally to an injury site, is able to stimulate adult tissue stem cells to grow and repair/replace the deficient tissue following injury. We have developed technologies to package the protein in a specialized manner that preserves its biological activity but simultaneously restricts its diffusion to unintended regions of the body. For example, when we treat a skeletal injury with this packaged protein we augment the natural ability to heal bone by 350%; and when this protein is delivered to the heart immediately after an infarction cardiac output is improved and complications related to scarring are reduced. This remarkable capacity to augment tissue healing is not limited to bones and the heart: the same powerful effect can be elicited in the brain, and skin injuries. The disease targets of stroke, bone fractures, heart attacks, and skin wounds and ulcers represent an enormous health care burden now, but this burden is expected to skyrocket because our population is quickly aging. Thus, our proposal addresses a present and ongoing challenge to healthcare for the majority of Californians, with a novel therapeutic strategy that mimics the body’s inherent repair mechanisms.
Statement of Benefit to California: 
Californians represent 1 in 7 Americans, and make up the single largest healthcare market in the United States. The diseases and injuries that affect Californians affect the rest of the US, and the world. For example, stroke is the third leading cause of death, with more than 700,000 people affected every year. It is a leading cause of serious long-term disability, with an estimated 5.4 million stroke survivors currently alive today. Symptoms of musculoskeletal disease are the number two most cited reasons for visit to a physician. Musculoskeletal disease is the leading cause of work-related and physical disability in the United States, with arthritis being the leading chronic condition reported by the elderly. In adults over the age of 70, 40% suffer from osteoarthritis of the knee and of these nearly 80% have limitation of movement. By 2030, nearly 67 million US adults will be diagnosed with arthritis. Cardiovascular disease is the leading cause of death, and is a major cause of disability worldwide. The annual socioeconomic burden posed by cardiovascular disease is estimated to exceed $400 billion annually and remains a major cause of health disparities and rising health care costs. Skin wounds from burns, trauma, or surgery, and chronic wounds associated with diabetes or pressure ulcer, exact a staggering toll on our healthcare system: Burns alone affect 1.25M Americans each year, and the economic global burden of these injuries approaches $50B/yr. In California alone, the annual healthcare expenditures for stroke, skeletal repair, heart attacks, and skin wound healing are staggering and exceed 700,000 cases, 3.5M hospital days, and $34B. We have developed a novel, protein-based therapeutic platform to accelerate and enhance tissue regeneration through activation of adult stem cells. This technology takes advantage of a powerful stem cell factor that is essential for the development and repair of most of the body’s tissues. We have generated the first stable, biologically active recombinant Wnt pathway agonist, and showed that this protein has the ability to activate adult stem cells after tissue injury. Thus, our developmental candidate leverages the body’s natural response to injury. We have generated exciting preclinical results in a variety of animals models including stroke, skeletal repair, heart attack, and skin wounding. If successful, this early translational award would have enormous benefits for the citizens of California and beyond.
Progress Report: 
  • In the first year of CIRM funding our objectives were to optimize the activity of the Wnt protein for use in the body and then to test, in a variety of injury models, the effects of this lipid-packaged form of Wnt. We have made considerable progress on both of these fronts. For example, in Roel Nusse and Jill Helms’ groups, we have been able to generate large amounts of the mouse form of Wnt3a protein and package it into liposomal vesicles, which can then be used by all investigators in their studies of injury and repair. Also, Roel Nusse succeeded in generating human Wnt3a protein. This is a major accomplishment since our ultimate goal is to develop this regenerative medicine tool for use in humans. In Jill Helms’ lab we made steady progress in standardizing the activity of the liposomal Wnt3a formulation, and this is critically important for all subsequent studies that will compare the efficacy of this treatment across multiple injury repair scenarios.
  • Each group began testing the effects of liposomal Wnt3a treatment for their particular application. For example, in Theo Palmer’s group, the investigators tested how liposomal Wnt3a affected cells in the brain following a stroke. We previously found that Wnt3A promotes the growth of neural stem cells in a petri dish and we are now trying to determine if delivery of Wnt3A can enhance the activity of endogenous stem cells in the brain and improve the level of recovery following stroke. Research in the first year examined toxicity of a liposome formulation used to deliver Wnt3a and we found it to be well tolerated after injection into the brains of mice. We also find that liposomal Wnt3a can promote the production of new neurons following stroke. The ongoing research involves experiments to determine if these changes in stem cell activity are accompanied by improved neurological function. In Jill Helms’ group, the investigators tested how liposomal Wnt3a affected cells in a bone injury site. We made a significant discovery this year, by demonstrating that liposomal Wnt3a stimulates the proliferation of skeletal progenitor cells and accelerates their differentiation into osteoblasts (published in Science Translational Medicine 2010). We also started testing liposomal Wnt3a for safety and toxicity issues, both of which are important prerequisites for use of liposomal Wnt3a in humans. Following a heart attack (i.e., myocardial infarction) we found that endogenous Wnt signaling peaks between post-infarct day 5-7. We also found that small aggregates of cardiac cells called cardiospheres respond to Wnt in a dose-responsive manner. In skin wounds, we tested the effect of boosting Wnt signaling during skin wound healing. We found that the injection of Wnt liposomes into wounds enhanced the regeneration of hair follicles, which would otherwise not regenerate and make a scar instead. The speed and strength of wound closure are now being measured.
  • In aggregate, our work on this project continues to move forward with a number of great successes, and encouraging data to support our hypothesis that augmenting Wnt signaling following tissue injury will provide beneficial effects.
  • In the second year of CIRM funding our objectives were to optimize packaging of the developmental candidate, Wnt3a protein, and then to continue to test its efficacy to enhance tissue healing. We continue to make considerable progress on the stated objectives. In Roel Nusse’s laboratory, human Wnt3a protein is now being produced using an FDA-approved cell line, and Jill Helms’ lab the protein is effectively packaged into lipid particles that delay degradation of the protein when it is introduced into the body.
  • Each group has continued to test the effects of liposomal Wnt3a treatment for their particular application. In Theo Palmer’s group we have studied how liposomal Wnt3a affects neurogenesis following stroke. We now know that liposomal Wnt3a transiently stimulates neural progenitor cell proliferation. We don’t see any functional improvement after stroke, though, which is our primary objective.
  • In Jill Helms’ group we’ve now shown that liposomal Wnt3a enhances fracture healing and osseointegration of dental and orthopedic implants and now we demonstrate that liposomal Wnt3a also can improve the bone-forming capacity of bone marrow grafts, especially when they are taken from aged animals.
  • We’ve also tested the ability of liposomal Wnt3a to improve heart function after a heart attack (i.e., myocardial infarction). Small aggregates of cardiac progenitor cells called cardiospheres proliferate to Wnt3a in a dose-responsive manner, and we see an initial improvement in cardiac function after treatment of cells with liposomal Wnt3a. the long-term improvements, however, are not significant and this remains our ultimate goal. In skin wounds, we tested the effect of boosting Wnt signaling during wound healing. We found that the injection of liposomal Wnt3a into wounds enhanced the regeneration of hair follicles, which would otherwise not regenerate and make a scar instead. The speed of wound closure is also enhanced in regions of the skin where there are hair follicles.
  • In aggregate, our work continues to move forward with a number of critical successes, and encouraging data to support our hypothesis that augmenting Wnt signaling following tissue injury will provide beneficial effects.
  • Every adult tissue harbors stem cells. Some tissues, like bone marrow and skin, have more adult stem cells and other tissues, like muscle or brain, have fewer. When a tissue is injured, these stem cells divide and multiply but only to a limited extent. In the end, the ability of a tissue to repair itself seems to depend on how many stem cells reside in a particular tissue, and the state of those stem cells. For example, stress, disease, and aging all diminish the capacity of adult stem cells to respond to injury, which in turn hinders tissue healing. One of the great unmet challenges for regenerative medicine is to devise ways to increase the numbers of these “endogenous” stem cells, and revive their ability to self-renew and proliferate.
  • The scientific basis for our work rests upon our demonstration that a naturally occurring stem cell growth factor, Wnt3a, can be packaged and delivered in such a way that it is robustly stimulates stem cells within an injured tissue to divide and self-renew. This, in turn, leads to unprecedented tissue healing in a wide array of bone injuries especially in aged animals. As California’s population ages, the cost to treat such skeletal injuries in the elderly will skyrocket. Thus, our work addresses a present and ongoing challenge to healthcare for the majority of Californians and the world, and we do it by mimicking the body’s natural response to injury and repair.
  • To our knowledge, there is no existing technology that displays such effectiveness, or that holds such potential for the stem cell-based treatment of skeletal injuries, as does a L-Wnt3a strategy. Because this approach directly activates the body’s own stem cells, it avoids many of the pitfalls associated with the introduction of foreign stem cells or virally reprogrammed autologous stem cells into the human body. In summary, our data show that L-Wnt3a constitutes a viable therapeutic approach for the treatment of skeletal injuries, especially those in individuals with diminished healing potential.
  • This progress report covers the period between Sep 01 2012through Aug 31 2013, and summarizes the work accomplished under ET funding TR1-01249. Under this award we developed a Wnt protein-based platform for activating a patient’s own stem cells for the purpose of tissue regeneration.
  • At the beginning of our grant period we generated research grade human WNT3A protein in quantities sufficient for all our discovery experiments. We then tested the ability of this WNT protein therapeutic to improve the healing response in animal models of stroke, heart attack, skin wounding, and bone fracture. These experimental models recapitulated some of the most prevalent and debilitating human diseases that collectively, affect millions of Californians.
  • At the end of year 2, we assembled an external review panel to select the promising clinical indication. The scientific advisory board unanimously selected skeletal repair as the leading indication. The WNT protein is notoriously difficult to purify; consequently in year 3 we developed new methods to streamline the purification of WNT proteins, and the packaging of the WNT protein into liposomal vesicles that stabilized the protein for in vivo use.
  • In years 3 and 4 we continued to accrue strong scientific evidence in both large and small animal models that a WNT protein therapeutic accelerates bone regeneration in critical size bony non-unions, in fractures, and in cases of implant osseointegration. In this last year of funding, we clarified and characterized the mechanism of action of the WNT protein, by showing that it activates endogenous stem cells, which in turn leads to faster healing of a range of different skeletal defects.
  • In this last year we also identified a therapeutic dose range for the WNT protein, and developed a route and method of delivery that was simultaneously effective and yet limited the body’s exposure to this potent stem cell factor. We initiated preliminary safety studies to identify potential risks, and compared the effects of WNT treatment with other commercially available bone growth factors. In sum, we succeeded in moving our early translational candidate from exploratory studies to validation, and are now ready to enter into the IND-enabling phase of therapeutic candidate development.
  • This progress report covers the period between Sep 01 2013 through April 30 2014, and summarizes the work accomplished under ET funding TR101249. Under this award we developed a Wnt protein-based platform for activating a patient’s own stem cells for purposes of tissue regeneration.
  • At the beginning of our grant period we generated research grade human WNT3A protein in quantities sufficient for all our discovery experiments. We then tested the ability of this WNT protein therapeutic to improve the healing response in animal models of stroke, heart attack, skin wounding, and bone fracture. These experimental models recapitulated some of the most prevalent and debilitating human diseases that collectively, affect millions of Californians. At the conclusion of Year 2 an external review panel was assembled and charged with the selection of a single lead indication for further development. The scientific advisory board unanimously selected skeletal repair as the lead indication.
  • In year 3 we accrued addition scientific evidence, using both large and small animal models, demonstrating that a WNT protein therapeutic accelerated bone healing. Also, we developed new methods to streamline the purification of WNT proteins, and improved our method of packaging of the WNT protein into liposomal vesicles (e.g., L-WNT3A) for in vivo use.
  • In year 4 we clarified the mechanism of action of L-WNT3A, by demonstrating that it activates endogenous stem cells and therefore leads to accelerated bone healing. We also continued our development studies, by identifying a therapeutic dose range for L-WNT3A, as well as a route and method of delivery that is both effective and safe. We initiated preliminary safety studies to identify potential risks, and compared the effects of L-WNT3A with other, commercially available bone growth factors.
  • In year 5 we initiated two new preclinical studies aimed at demonstrating the disease-modifying activity of L-WNT3A in spinal fusion and osteonecrosis. These two new indications were chosen by a CIRM review panel because they represent an unmet need in California and the nation. We also initiated development of a scalable manufacturing and formulation process for both the WNT3A protein and L-WNT3A formulation. These two milestones were emphasized by the CIRM review panel to represent major challenges to commercialization of L-WNT3A; consequently, accomplishment of these milestones is a critical yardstick by which progress towards an IND filing can be assessed.

Defining the Isoform-Specific Effects of Apolipoprotein E on the Development of iPS Cells into Functional Neurons in Vitro and in Vivo

Funding Type: 
New Faculty II
Grant Number: 
RN2-00952
ICOC Funds Committed: 
$2 847 600
Disease Focus: 
Stroke
Neurological Disorders
Stem Cell Use: 
iPS Cell
Cell Line Generation: 
iPS Cell
oldStatus: 
Active
Public Abstract: 
GOALS We propose to determine the effects of different forms of apoE on the development of induced pluripotent stem (iPS) cells into functional neurons. In Aim 1, iPS cells will be generated from skin cells of adult knock-in (KI) mice expressing different forms of human apoE and in humans with different apoE genotypes. In Aim 2, the development of the iPS cells into functional neurons in culture and in mouse brains will be compared. In Aim 3, the effects of different forms of apoE on the functional recovery of mice with acute brain injury treated with iPS cell–derived neural stem cells (NSCs) will be assessed. RATIONALE AND SIGNIFICANCE The central nervous system (CNS) has limited ability to regenerate and recover after injury. For this reason, recovery from acute and chronic neurological diseases, such as stroke and Alzheimer’s disease (AD), is often incomplete and disability results. Embryonic stem cells have great promise for treating or curing neurological diseases, but their therapeutic use is limited by ethical concerns and by rejection reactions after allogenic transplantation. The generation of iPS cells from somatic cells offers a way to potentially circumvent the ethical issues and to generate patient- and disease-specific stem cells for future therapy. In the CNS, apoE plays important roles in lipid homeostasis and in neuronal maintenance. However, apoE2, apoE3, and apoE4 differ in their ability to accomplish these tasks. ApoE4, the major genetic risk factor for AD, is associated with poor clinical outcome and more rapid progression or greater severity of head trauma, stroke, Parkinson’s disease, multiple sclerosis, and amyotrophic lateral sclerosis—all potential targets of stem cell therapy. This proposal builds on three novel findings in human apoE-KI mice. (1) NSCs express apoE. (2) ApoE plays a role in cell-fate determination (neuron vs astrocyte) of NSCs. (3) ApoE4 impairs the neuronal development of NSCs. Thus, we hypothesize that transplantation of iPS cells derived from apoE4 carriers (~20% of the general population and ~50% of AD patients) might not be beneficial or even detrimental for patients with neurological diseases. We propose in vitro and in vivo studies to assess the effects of different forms of apoE on the development of iPS cells into functional neurons and on the functional recovery of mice with acute brain injury treated with iPS cell-derived NSCs. These studies will shed light on the regulation of neuronal development of iPS cells and help to “optimize” future iPS cell therapy for neurological diseases. SPECIFIC AIMS Aim 1. To establish adult mouse and human iPS cell lines with different apoE genotypes. Aim 2. To determine the isoform-specific effects of apoE on the development of iPS cells into functional neurons in culture and in mouse brains. Aim 3. To assess the isoform-specific effects of apoE on the functional recovery of mice with acute (stroke) brain injury treated with iPS cell-derived NSCs.
Statement of Benefit to California: 
CONTRIBUTION TO THE CALFORNIA ECONOMY: A major goal of regenerative medicine is to repair damaged cells or tissue. My research focuses on (1) understanding the role of neuronal regeneration in central nervous system function and (2) developing stem cell therapy for acute and chronic neurological diseases, including stroke and Alzheimer's disease. Stroke and Alzheimer's disease are the leading causes of disability and dementia and are the fastest growing form of neurological diseases in California, in the USA, and worldwide. My research could benefit the California economy by creating jobs in the biomedical sector. Ultimately, this study could help reduce the adverse impact of neurological diseases. Thereby, I hope to increase the productivity and enhance the quality of life for Californians. The results of my studies will also help develop new technology that could contribute to the California biotechnology industry. The studies will characterize multiple lines of induced pluripotent stem (iPS) cells carrying apoE3, a protein protective to the brain, or apoE4, which is detrimental to the brain and is associated with increased risk of Alzheimer’s disease and other neurodegenerative disorders. These cell lines could be valuable for biotechnology companies and researchers who are screening for drug compounds targeting different neurological diseases. CONTRIBUTION TO THE HEALTH OF CALFORNIANS: The most important contribution of the studies will be to improve the health of Californians. Diseases that are the target of regenerative medicine, such as stroke and Alzheimer’s disease, are major causes of mortality and morbidity, resulting in billions of dollars in healthcare costs and lost productivity. As we continue our efforts in medical research, we hope to one day unlock the secrets of brain development and repair. This knowledge will help medical researchers develop beneficial therapies beyond what is currently available and potentially improve the quality of life and life expectancy of patients with neurological diseases, such as stroke and Alzheimer’s disease.
Progress Report: 
  • The goal of this proposal is to determine the isoform-specific effects of apolipoprotein (apo) E on the development of induced pluripotent stem (iPS) cells into functional neurons both in vitro and in mice. Toward this goal, we have made significant progress in Aims 1 and 2.
  • First, we further demonstrated that neural stem cells (NSCs) express apoE. ApoE-KO mice had significantly less hippocampal neurogenesis, but significantly more astrogenesis, than wildtype mice due to decreased Noggin expression in NSCs. In contrast, neuronal maturation in apoE4 knock-in (apoE4-KI) mice was impaired due to reduced survival and function of GABAergic interneurons in the hilus of the hippocampus, and a GABAA receptor potentiator rescued the apoE4-associated decrease in hippocampal neurogenesis. Thus, apoE plays an important role in hippocampal neurogenesis, and the apoE4 isoform impairs GABAergic input to newborn neurons, leading to decreased neurogenesis. A paper describing these data was published in Cell Stem Cell (Li G. et al. 2009, 5:634-645), which evidently is the 400th publication of CIRM-funded projects.
  • Second, we established mouse iPS cell lines from adult mouse fibroblasts of wildtype, apoE knockout (apoE-KO), human apoE2-KI, human apoE3-KI, and human apoE4-KI mice.
  • Finally, we developed NSC lines from mouse iPS cells with different apoE genotypes (wildtype mouse apoE, apoE-KO, apoE2, apoE3, and apoE4). These cell lines will be used to study the effects of apoE isoforms on neuronal development in vitro in culture and in vivo in mouse models.
  • The goal of this proposal is to determine the isoform-specific effects of apolipoprotein (apo) E on the development of induced pluripotent stem (iPS) cells into functional neurons both in vitro and in mice. Toward this goal, we have made significant progress in the past year, as summarized below.
  • First, We developed human iPS cells from skin fibroblasts of individuals with different apoE genotypes. We are fully characterizing these human iPS cell lines.
  • Second, We are establishing neural stem cell (NSC) lines from human iPS cells with different apoE genotypes. Some of the NSCs have been maintained in monolayer cultures for many generations. These NSCs will be used to study the effects of apoE isoforms on neuronal development in vitro in cultures and in vivo in mice.
  • Finally, we demonstrated that mouse apoE4-NSCs generated significantly fewer total neurons and fewer GABAergic interneurons than mouse apoE3-NSCs in culture. Thus, the detrimental effects of apoE4 on neurogenesis and GABAergic interneuron survival, as we observed in vivo in apoE4 knock-in mice (Li G. et al. Cell Stem Cell, 2009, 5:634-645), are recapitulated in cultures of mouse iPS cell–derived NSCs in vitro.
  • The goal of this proposal is to determine the isoform-specific effects of apolipoprotein (apo) E on the development of induced pluripotent stem (iPS) cells into functional neurons both in vitro and in mice. Toward this goal, we have made significant progress in all three aims in the past year, as summarized below.
  • 1) We have fully characterized two apoE3/3-hiPS cell lines and two apoE4/4-iPS cell lines.
  • 2) We have established NSC lines from human iPS cells with an apoE3/3 or apoE4/4 genotype. The hNSCs have been maintained in suspension or monolayer culture for multiple passages.
  • 3) We demonstrated that apoE4-hNSCs generated ~50% fewer GABAergic interneurons than apoE3-hNSCs in culture. Thus, the detrimental effects of apoE4 on GABAergic interneuron survival, as we observed in vivo in apoE4 knock-in mice (Li G. et al. Cell Stem Cell, 2009, 5:634-645), are recapitulated in cultures of human iPS cell-derived NSCs in vitro.
  • 4) We established protocols in our lab to differentiate human iPS cell-derived NSCs into different types of neurons in cultures.
  • The goal of this proposal is to determine the isoform-specific effects of apolipoprotein (apo) E on the development of induced pluripotent stem (iPS) cells into functional neurons both in vitro and in mice. Toward this goal, we have made significant progress in all three aims in the past year, as summarized below.
  • 1) We demonstrated that apoE4-miPSC-derived mNSCs had a greater “age-dependent (passage-dependent)” decrease in generation and/or survival of MAP2-positive neurons in cultures.
  • 2) We also demonstrated that apoE4-miPSC-derived mNSCs had an even greater “age-dependent (passage-dependent)” decrease in generation and/or survival of GAD67-positive GABAergic neurons, as seen in vivo in apoE4 knock-in mice (Li et al., Cell Stem Cell, 2009, 5:634–645).
  • 3) We expanded the pilot study reported last year and confirmed the detrimental effect of apoE4 on GABAergic interneuron development/survival of hiPS cell-derived hNSCs. ApoE4 also increased tau phosphorylation, one of the pathological hallmarks of Alzheimer’s disease, in neurons derived from apoE4-hiPS cells.
  • 4) We established a protocol to transplant apoE-miPS cell-derived mNSCs into mouse brains. The transplanted apoE-mNSCs developed into neurons and astrocytes and integrated into the neural circuitry.
  • The goal of this proposal is to determine the isoform-specific effects of apolipoprotein (apo) E on the development of pluripotent stem cells into functional neurons in vitro in culture and in vivo in mice for potential cell replacement therapy. Toward this goal, we have made significant progress in all three aims in the past year, as summarized below.
  • 1) We demonstrated that mouse GABAergic progenitors transplanted into the hilus of apoE3-KI and apoE4-KI mice developed into mature interneurons and functionally integrated into the hippocampal circuitry.
  • 2) We also demonstrated that transplantation of mouse GABAergic progenitors into the hilus of apoE4-KI mice rescued learning and memory deficits.
  • 3) Transplantation of mouse GABAergic progenitors into the hilus of hippocampus also rescued learning and memory deficits in apoE4-KI mice expressing Alzheimer’s disease-causing APP mutations.

High throughput modeling of human neurodegenerative diseases in embryonic stem cells

Funding Type: 
New Faculty II
Grant Number: 
RN2-00919
ICOC Funds Committed: 
$2 259 092
Disease Focus: 
Amyotrophic Lateral Sclerosis
Neurological Disorders
Neuropathy
Neurological Disorders
Stem Cell Use: 
Embryonic Stem Cell
Cell Line Generation: 
Embryonic Stem Cell
oldStatus: 
Active
Public Abstract: 
An important class of neurological diseases predominantly affects spinal motor neurons, the neurons that control muscle movement. The most well known of these motor neuronopathies is Amyotrophic Lateral Sclerosis (ALS), commonly referred to as Lou Gehrig’s disease for the famous Yankee first baseman who died of the disease. The first symptoms of ALS are usually increasing difficulty walking or speaking clearly. People with ALS progressively lose their ability to initate and control movements, and may become totally paralyzed during the late stages of the disease. There are no cures or effective treatments for these diseases. Riluzole (Rilutek), the only FDA approved medication for ALS, only modestly slows disease progression. Consequently, ALS is usually fatal within one to five years from onset, with half dying within eighteen months. Although genetic studies have identified many mutations that cause these diseases, it is not understood why these mutations kill motor neurons. This lack of understanding about the root causes of motor neuron diseases currently hinders the development of effective treatments. We seek to study motor neurons carrying these mutations in cell culture dishes to understand how these diseases sicken and kill these cells. To generate these motor neurons, we will use embryonic stem cells. Embryonic stem cells can become any cell in our body, including motor neurons. We have developed a new technology that allows us to quickly replace healthy genes with mutant genes in mouse embryonic stem cells. We will use this technology to insert both normal and disease-associated versions of genes into embryonic stem cells. Study of the healthy and mutant mutant motor neurons derived from these embryonic stem cells will shed light on the ways in which the mutations cause harm. The development of cell based models of human diseases is likely to have additional benefits as well. For example, diseased motor neurons grown in cell culture dishes can be quickly and efficiently screened with potential drugs to discover agents that slow, halt or reverse the cellular damage. It is our hope that these experiments will both deepen our understanding of important neurodegenerative disorders, and lead to new directions for the development of effective therapies.
Statement of Benefit to California: 
Over 6,000 Americans are diagnosed each year with motor neuronopathies, about the same as are diagnosed with multiple sclerosis. One form of this illness, ALS, is responsible for about one in every 800 deaths, and cause many lengthy and costly hospital admissions. We propose using stem cells to model these diseases so that we can gain a deeper understanding of their root causes. It is our expectation that this deeper understanding will lead to new and better approaches to the treatment of these disorders. In addition, our technology for developing embryonic stem cell-based models of human diseases is likely to have applications in the biotechnology sector. Although our technology is most applicable for modeling simple dominant genetic diseases, it can be adapted to model recessive and complex disorders. Beyond increasing our understanding of human diseases, these cellular models represent useful screening tools for testing novel pharmacological treatments. Identification and development of these new therapies may support new companies or new products for existing companies. We hope that using stem cells to model neurodegenerative disorders will lead to progress in the fight against these diseases, as well as provide the tools and examples for those in academia and industry who hope to create stem cell models of other clinically important disorders.
Progress Report: 
  • We have been developing new tools for the genetic modification of embryonic stem cells (ESCs). Part of the potential for use of ESCs in treatments or as models of disease depends on the ability to change genes within ESCs. We have developed a novel system, which we call the Floxin system, that allows for the more efficient modification of genes within mouse ESCs than has been historically feasible. We have used this system to insert mutations that cause human diseases into mouse ESCs. Introducing human mutations into ESCs has allowed us to study the function of these mutations in the context of stem cell function and gain insight into how these mutations cause human disease.
  • We are interested in extending our findings by modeling an important class of neurological diseases that predominantly affect spinal motor neurons, the neurons that control muscle movement. The most well known of these motor neuronopathies is Amyotrophic Lateral Sclerosis (ALS), commonly referred to as Lou Gehrig’s disease, but there are a number of other motor neuronopathies including Hereditary Motor Neuronopathy and Spinal Muscular Atrophy.
  • Human genetic studies have identified many mutations that cause these diseases, but it is not understood why these mutations kill motor neurons. This lack of understanding about the root causes of motor neuron diseases currently hinders the development of effective treatments. We are currently using the Floxin system to introduce human motor neuronopathy-associated mutations into mouse ESCs. We have introduced mutations into two disease-associated genes, and are deriving motor neurons from these modified ESCs to study how the mutations kill these cells.
  • The development of cell-based models of human diseases is likely to have additional benefits as well. For example, diseased motor neurons grown in cell culture dishes can be quickly and efficiently screened with potential drugs to discover agents that slow, halt or reverse the cellular damage. It is our hope that these experiments will both deepen our understanding of important neurodegenerative disorders, and lead to new directions for the development of effective therapies.
  • We have made the resource of Floxin vectors and the greater than 24,000 characterized Floxin compatible ESC lines available to the research community. Application of the Floxin technology to this resource will allow genetic modification of more than 4,500 genes in ESCs. Furthermore, we are adapting the Floxin technology for use in human ESCs which may allow for tractable genetic engineering in these cells. We anticipate that this technology will allow many researchers to create cellular models of human disease and other genetic modifications that will facilitate the use of stem cells in fighting diverse diseases.
  • We have developed new tools for the genetic modification of embryonic stem cells (ESCs) and are using these tools to model human diseases. Part of the potential for use of ESCs in treatments or as models of disease depends on the ability to change genes within ESCs. We have developed a novel system, which we call the Floxin system, that allows for the more efficient modification of genes within mouse ESCs than has been historically feasible. We use this system to insert mutations that cause human diseases into mouse ESCs. Introducing human mutations into ESCs has allowed us to study the function of these mutations in the context of stem cell function and gain insight into how these mutations cause human disease. To date, we have investigated an inherited congenital malformation syndrome called Orofaciodigital syndrome and elucidated that the underlying birth defects are caused by misregulation of cilia and centrioles, structures within all cells. We have also used our system to investigate how genes are regulated by Polycomb-like proteins and to reveal how cilia control ESC differentiation into motor neurons, findings that shed light on the control of motor neuron production from ESCs.
  • We are extending our findings by modeling an important class of neurological diseases that predominantly affect spinal motor neurons, the neurons that control muscle movement. The most well known of these motor neuronopathies is Amyotrophic Lateral Sclerosis (ALS), commonly referred to as Lou Gehrig’s disease, but there are a number of other motor neuronopathies including Hereditary Motor Neuronopathy and Spinal Muscular Atrophy. Human genetic studies have identified many mutations that cause these diseases, but it is not understood why these mutations kill motor neurons. This lack of understanding about the root causes of motor neuron diseases currently hinders the development of effective treatments.
  • We have used the Floxin system to introduce human motor neuronopathy-associated mutations into mouse ESCs. We have introduced mutations into two disease-associated genes, and have derived motor neurons from these modified ESCs to study how the mutations kill these cells. The development of cell-based models of human diseases is likely to have additional benefits as well. For example, diseased motor neurons grown in cell culture dishes can be quickly and efficiently screened with potential drugs to discover agents that slow, halt or reverse the cellular damage. It is our hope that these experiments will both deepen our understanding of important neurodegenerative disorders, and lead to new directions for the development of effective therapies.
  • We have made the resource of Floxin vectors and the greater than 24,000 characterized Floxin compatible ESC lines available to the research community. Application of the Floxin technology to this resource will allow genetic modification of more than 4,500 genes in ESCs. Furthermore, we are hoping to adapt the Floxin technology for use in human ESCs which may allow for tractable genetic engineering in these cells. We anticipate that this technology will allow many researchers to create cellular models of human disease and other genetic modifications that will facilitate the use of stem cells in fighting diverse diseases.
  • An important class of neurological diseases predominantly affects spinal motor neurons, the neurons that control muscle movement. The most well known of these motor neuronopathies is Amyotrophic Lateral Sclerosis (ALS), commonly referred to as Lou Gehrig’s disease for the famous Yankee first baseman who died of the disease. The first symptoms of ALS are usually increasing difficulty walking or speaking clearly. People with ALS progressively lose their ability to initate and control movements, and may become totally paralyzed during the late stages of the disease. There are no cures or effective treatments for these diseases. Riluzole (Rilutek), the only FDA approved medication for ALS, only modestly slows disease progression. Consequently, ALS is usually fatal within one to five years from onset, with half dying within eighteen months.
  • Although genetic studies have identified many mutations that cause these diseases, it is not understood why these mutations kill motor neurons. This lack of understanding about the root causes of motor neuron diseases currently hinders the development of effective treatments. We seek to study motor neurons carrying these mutations in cell culture dishes to understand how these diseases sicken and kill these cells.
  • To generate these motor neurons, we are using embryonic stem cells. Embryonic stem cells can become any cell in our body, including motor neurons. We have developed a new technology that allows us to quickly replace healthy genes with mutant genes in mouse embryonic stem cells. We are using this technology to insert both normal and disease-associated versions of genes into embryonic stem cells. Study of the healthy and mutant mutant motor neurons derived from these embryonic stem cells will shed light on the ways in which the mutations cause harm.
  • We have been using the mutant embryonic stem cells to assay leading hypotheses about how diseases like ALS begin. In addition, we are using the embryonic stem cells to create new animal models of ALS. Finally, we are adapting our technology to be able to create more faithful models of disease using embryonic stem cells in order to expedite understanding into the origins of these diseases.
  • Neurodegenerative diseases, including Alzheimer disease, Parkinson disease, and Amyotrophic Lateral Sclerosis (ALS, also known as Lou Gehrig’s disease), affect an increasing proportion of our population as the median age increases. There are no cures for any of these disorders. One reason for the absence of cures has been the absence of good models to understand how neurodegeneration happens.
  • Genetic studies have identified many of the genes involved in neurodegeneration. To understand how these mutations lead to motor neuron degeneration in ALS, we have creased embryonic stem cells (ESCs) that contain the human ALS-associated mutations. We have also created mice that express these human ALS-associated mutations. We are studying motor neurons derived from the ESCs and the mutant mice to understand how motor neurons die in ALS. We are defining the proteins and RNAs that interact with normal and disease-associated proteins, and following the mutant neurons over time to examine how they die. Currently, we are testing the hypothesis that disease mutations alter the gene product’s normal interactions, leading to a tonic increase in cell death rate. After several decades of life, the loss of neurons surpasses compensatory mechanisms, leading to the emergence of symptoms.
  • Neurodegenerative diseases, including Alzheimer disease, Parkinson disease, and Amyotrophic Lateral Sclerosis (ALS, also known as Lou Gehrig’s disease), affect an increasing proportion of our population as the median age increases. There are no cures for any of these disorders. One reason for the absence of cures has been the absence of good models to understand how neurodegeneration happens.
  • Genetic studies have identified many of the genes involved in neurodegeneration. To understand how these mutations lead to motor neuron degeneration in ALS, we have creased embryonic stem cells (ESCs) that contain the human ALS-associated mutations. We have also created mice that express these human ALS-associated mutations. We studied motor neurons derived from the ESCs and the mutant mice and found that motor neurons with ALS-associated mutations die at increased rates. We identified proteins that interact with normal and disease-associated proteins. We identified that mutant proteins showed different interactions than normal proteins. After several decades of life, the loss of neurons surpasses compensatory mechanisms, leading to the emergence of symptoms.

Mechanisms in Choroid Plexus Epithelial Development

Funding Type: 
New Faculty II
Grant Number: 
RN2-00915
ICOC Funds Committed: 
$2 994 328
Disease Focus: 
Neurological Disorders
Stem Cell Use: 
Embryonic Stem Cell
oldStatus: 
Active
Public Abstract: 
Buried deep inside the brain are cells known as choroid plexus epithelial (CPe) cells. Although not as famous as other cells in the nervous system, CPe cells perform a large number of important jobs that keep the brain and spinal cord healthy. They produce the fluid (known as cerebrospinal fluid, or CSF) that bathes the brain and spinal cord with many nourishing chemicals, which promote normal nervous system health and function, learning and memory, and neural repair following injury. In addition, CPe cells protect the brain and spinal cord from toxins – such as heavy metals and the amyloid-beta peptide associated with Alzheimer’s disease – by absorbing them or preventing them from entering the nervous system altogether by forming the so-called blood-CSF barrier. Accordingly, as CPe functions diminish during normal aging or in accelerated fashion in certain diseases, memory loss, Alzheimer’s disease, and a number of other neurologic and neuropsychiatric disorders may ensue or become worse. The ability to grow and make CPe cells should therefore enable many clinical applications, such as CPe cell replacements, transplants, and pharmaceutical studies to identify beneficial drugs that can pass through the blood-CSF barrier. However, all of these potential applications are limited by the current inability to make and expand CPe cells in culture. Our published and preliminary studies suggest that it should be feasible to generate CPe cells in culture. Our broad goals are to study how CPe cells form during normal development, then use this information to make human CPe cells for clinical applications. To achieve this goal, our approach will be to use mice to study how the CPe develops normally, then use both mouse and human stem cells to make CPe cells in culture. Our published and preliminary studies have defined one critical factor for this process (known as Bmp4) and identify candidate factors that work with Bmp4 to regulate whether or not CPe cells are formed. In Aim 1, we test whether a molecule known as Fgf8 provides CPe “competency” – i.e. whether Fgf8 allows cells to become CPe cells when exposed to Bmp4. In Aim 2, we test whether a gene known as Lhx2 prevents cortical cells from becoming CPe cells in response to Bmp4. In Aim 3, we manipulate Bmp4, Fgf8, and Lhx2 in hESC cultures to make human CPe cells. If successful, this proposal should greatly improve our understanding of normal CPe development and enable a number of CPe-based clinical applications with significant potential to improve human health.
Statement of Benefit to California: 
Our proposal to study choroid plexus epithelial (CPe) cell development and to make CPe cells in culture for clinical applications should benefit the State of California and its citizens in a number of ways. In the short term, this project will provide employment, education and training in stem cell research for a handful of California residents, and will support California-based companies that provide supplies for the stem cell and biomedical research communities. In the longer term, success in making CPe cells in culture should enable many new CPe-based clinical applications, stimulate CPe studies and applications by stem cell companies, and enable screens to identify agents that allow for passage of therapeutics across the blood-CSF barrier, which remains a significant roadblock to the development of pharmaceuticals for neurological and neuropsychiatric disorders. Such outcomes would ultimately stimulate investment in California-based companies and benefit the health of many California citizens, which may reduce the economic burden of health care in the state.
Progress Report: 
  • Our project goals are to define the factors involved in choroid plexus epithelial (CPe) cell development in mice, then apply this information to generate CPe cells from mouse and human embryonic stem cells (ESCs) for clinical applications. The first Aim is to determine whether a factor known as Fgf8 promotes CPe fate, the second Aim addresses whether the Lhx2 transcription factor inhibits CPe, and the third Aim is to generate human CPe cells in culture. Significant progress on these Aims has been made during this first year of the grant. Most importantly, multiple lines of evidence for CPe differentiation from both mouse and human ESCs have been obtained. In addition, the genetically-engineered mESC lines needed for the Lhx2 studies in Aim 2 have been successfully generated and validated. Our major goals for the next year are to further replicate, confirm, and optimize the generation of CPe cells in our mouse and human ESC cultures, and to perform the initial experiments that should determine whether manipulating Fgf8 and Lhx2 in the ESC cultures will enhance CPe generation in culture.
  • Our goal is to define the factors involved in choroid plexus epithelial (CPe) cell development in mice, then to apply this knowledge to generate CPe cells from mouse and human embryonic stem cells (ESCs) for clinical applications. The first two Aims examine Fgf8 and Lhx2 as promoter and inhibitor, respectively, of CPe fate, and the third Aim is to generate human CPe cells in culture. Unexpectedly, we obtained significant evidence for CPe differentiation from both mouse and human ESCs during year 1 of the award. Our aims for year 2 were therefore modified to accelerate the translation of our findings towards a CPe-based regenerative medicine. This year, we developed a second cell culture system for deriving mouse CPe cells, and established a functional assay for CPe cells in culture, which we used to confirm the function of our derived mouse CPe cells. To sort and purify CPe cells for clinical applications, we began characterizing CPe cell complexity, size, and mitochondrial content by flow cytometry, obtained a mouse line with fluorescent CPe cells, and identified three antibodies that may be useful for sorting human CPe cells. A stereotaxic injection system was built, and institutional approvals were obtained, to establish methods for replacing or transplanting CPe cells in the mouse brain.
  • The goal of this project is to define the factors involved in choroid plexus epithelial cell (CPEC) development in mice, then to apply this knowledge to generate CPECs from mouse and human embryonic stem cells (ESCs) for clinical applications. The first two Aims used mice to examine a potential promoter and inhibitor, respectively, of CPEC fate, and the third Aim is to generate human CPECs in culture. Unexpectedly early success in CPEC derivation from human ESCs has allowed us to accelerate Aim 3 and the pursuit of translational goals this year. We further optimized our existing human CPEC derivation method and developed a second method (a combined suspension-adherent system) that may prove to be much more efficient. Several new GMP-compliant human ESC lines were approved and obtained. To facilitate the translational efforts, we made many new mouse ESC lines that were designed to fluoresce when CPECs are produced, and this was confirmed using the first of these lines. A crude CPEC purification strategy was also developed, and using this strategy, transplantation of partially-purified CPECs into mice was established in the lab this year. Remarkably, we found that transplanted mESC-derived CPECs, on their own, can integrate into endogenous choroid plexus with relatively high efficiency. This opens up several new and exciting therapeutic possibilities. To further enhance choroid plexus engraftment, a mouse CPEC ablation approach is currently being tested. A collaboration was initiated to profile all of the genes expressed by the purified mouse ESC-derived CPECs, and to compare this profile to those expressed by the choroid plexus in developing mice and humans. Industry partnerships and non-provisional patenting were also pursued to enhance the prospects for human CPEC applications in drug screening and treating patients with a wide range of neurodegenerative and other nervous system disorders.
  • The goal of this project is to define factors involved in choroid plexus epithelial cell (CPEC) development in mice, then to apply this knowledge to generate CPECs from mouse and human embryonic stem cells (ESCs) for clinical applications. Unexpected early success in generating ESC-derived CPECs (dCPECs) allowed us to accelerate and focus on the more translational goals of the project this year. We tested two new culture systems, with promising results from a more controllable and scalable monolayer culture system that will facilitate the improvement of dCPEC generation efficiency. New transcriptome profiling studies allowed us to better define highly-expressed genes for cell surface proteins, which will be targeted to purify dCPECs for downstream applications. New double-labelling and whole mount preparations of mouse choroid plexus have been devised to facilitate ongoing efforts to improve dCPEC engraftment of host choroid plexus after injection, and a new functional assay for dCPEC barrier formation and regulation has been established to complement an already-existing functional secretion assay in the lab. Efforts are also now underway to generate fluorescent and luminescent CPEC reporter hESC lines that should greatly facilitate dCPEC process development (derivation and purification). During this past year, new industry partners were recruited, an initial paper describing the dCPEC technology was published, and an initial patent application on the dCPEC technology was filed.
  • The goal of this project is to define factors involved in choroid plexus epithelial cell (CPEC) development in mice, then to apply this knowledge to generate CPECs from mouse and human embryonic stem cells (ESCs) for clinical applications. Unexpected early success in generating ESC-derived CPECs (dCPECs) allowed us to accelerate and focus on the more translational goals of the project this year. We further developed two culture systems - a more controllable monolayer system and more scalable rotational aggregate system - that will facilitate the dCPEC work. After several disappointments, improvements in dCPEC differentiation efficiency were obtained with two pharmacologic agents. With help from transcriptome profiling studies, we identified cell surface proteins that could be utilized for dCPEC enrichment, with initial promising results for one candidate surface antigen. A robust whole mount choroid plexus culture system was newly developed to facilitate efforts to improve dCPEC engraftment of host choroid plexus, and methods surrounding the stereotactic injection of dCPECs have been improved. After some difficulties, human TTR BAC constructs that express fluorescent and luminescent reporters were created and validated; these will be used to generate new CPEC reporter mouse lines for endpoint and longitudinal studies, and for in vivo drug testing of compounds that enhance TTR production and CPEC secretion. The initial patent application on the dCPEC technology was reviewed by the US PTO, and a revision was submitted.

Systemic Protein Factors as Modulators of the Aging Neurogenic Niche

Funding Type: 
Basic Biology II
Grant Number: 
RB2-01637
ICOC Funds Committed: 
$1 522 800
Disease Focus: 
Alzheimer's Disease
Neurological Disorders
Stem Cell Use: 
Embryonic Stem Cell
iPS Cell
oldStatus: 
Active
Public Abstract: 
Approaches to repair the injured brain or even prevent age-related neurodegeneration are in their infancy but there is growing interest in the role of neural stem cells in these conditions. Indeed, there is hope that some day stem cells can be used for the treatment of spinal cord injury, stroke, or Parkinson’s disease and stem cells are even mentioned in the public with respect to Alzheimer’s disease. To utilize stem cells for these conditions and, equally important to avoid potential adverse events in premature clinical trials, we need to understand the environment that supports and controls neural stem cell survival, proliferation, and functional integration into the brain. This “neurogenic” environment is controlled by local cues in the neurogenic niche, by cell-intrinsic factors, and by soluble factors which can act as mitogens or inhibitory factors potentially over longer distances. While some of these factors are starting to be identified very little is known why neurogenesis decreases so dramatically with age and what factors might mediate these changes. Because exercise or diet can increase stem cell activity even in old animals and lead to the formation of new neurons there is hope that neurogenesis in the aged brain could be restored to that seen in younger brains and that stem cell transplants could survive in an old brain given the right “young” environmental factors. Indeed, our preliminary data demonstrate that systemic factors circulating in the blood are potent regulators of neurogenesis. By studying how the most promising of these factors influence key aspects of the neurogenic niche in vitro and in vivo we hope to gain an understanding about the molecular interactions that support stem cell activity and the generation of new neurons in the brain. The experiments supported under this grant will help us to identify and understand the minimal signals required to regulate adult neurogenesis. These findings could be highly significant for human health and biomedical applications if they ultimately allow us to stimulate neurogenesis in a controlled way to repair, augment, or replace neural networks that are damaged or lost due to injury and degeneration.
Statement of Benefit to California: 
In California there are hundreds of thousands of elderly individuals with age-related debilitating brain injuries, ranging from stroke to Alzheimer’s and Parkinson’s disease. Approaches to repair the injured brain or even prevent age-related neurodegeneration are in their infancy but there is growing interest in the role of neural stem cells in these conditions. However, to potentially utilize such stem cells we need to understand the basic mechanisms that control their activity in the aging brain. The proposed research will start to address this problem using a novel and innovative approach and characterize protein factors in blood that regulate stem cell activity in the old brain. Such factors could be used in the future to support stem cell transplants into the brain or to increase the activity of the brain’s own stem cells.
Progress Report: 
  • We are interested in identifying soluble protein factors in blood which can either promote or inhibit stem cell activity in the brain. Through a previous aging study and the transfer of blood from young to old mice and vice versa we had identified several proteins which correlated with reduced stem cell function and neurogenesis in young mice exposed to old blood. Over the past year we studied two factors, CCL11/eotaxin and beta2-microglobulin in more detail in tissue culture and in mice. We could demonstrate that both factors administered into the systemic environment of mice reduce neurogenesis in a brain region involved in learning and memory. We have also begun to test the effect of these factors on human neural stem cells and we started experiments to try to identify protein factors which can enhance neurogenesis.
  • While age-related cognitive dysfunction and dementia in humans are clearly distinct entities and affect different brain regions, the aging brain shows the telltale molecular and cellular changes that characterize most neurodegenerative diseases. Remarkably, the aging brain remains plastic and exercise or dietary changes can increase cognitive function in humans and animals, with animal brains showing a reversal of some of the aforementioned biological changes associated with aging. We showed recently that blood-borne factors coming outside the brain can inhibit or promote adult neurogenesis in an age-dependent fashion in mice. Accordingly, exposing an old mouse to a young systemic environment or to plasma from young mice increased neurogenesis, synaptic plasticity, and improved contextual fear conditioning and spatial learning and memory. Preliminary proteomic studies show several proteins with stem cell activity increase in old “rejuvenated” mice supporting the notion that young blood may contain increased levels of beneficial factors with regenerative capacity. We believe we have identified some of these factors now and tested them on cultured mouse and human neural stem cell derived cells. Preliminary data suggest that these factors have beneficial effects and we will test whether these effects hold true in living mice.
  • Cognitive function in humans declines in essentially all domains starting around age 50-60 and neurodegeneration and Alzheimer’s disease seems to be inevitable in all but a few who survive to very old age. Mice with a fraction of the human lifespan show similar cognitive deterioration indicating that specific biological processes rather than time alone are responsible for brain aging. While age-related cognitive dysfunction and dementia in humans are clearly distinct entities the aging brain shows the telltale molecular and cellular changes that characterize most neurodegenerative diseases including synaptic loss, dysfunctional autophagy, increased inflammation, and protein aggregation. Remarkably, the aging brain remains plastic and exercise or dietary changes can increase cognitive function in humans and animals. Using heterochronic parabiosis or systemic application of plasma we showed recently that blood-borne factors present in the systemic milieu can rejuvenate brains of old mice. Accordingly, exposing an old mouse to a young systemic environment or to plasma from young mice increased neurogenesis, synaptic plasticity, and improved contextual fear conditioning and spatial learning and memory. Unbiased genome-wide transcriptome studies from our lab show that hippocampi from old “rejuvenated” mice display increased expression of a synaptic plasticity network which includes increases in c-fos, egr-1, and several ion channels. In our most recent studies, plasma from young but not old humans reduced neuroinflammation in brains of immunodeficient mice (these mice allow us to avoid an immune response against human plasma). Together, these studies lend strong support to the existence of factors with beneficial, “rejuvenating” activity in young plasma and they offer the opportunity to try to identify such factors.
  • Cognitive function in humans declines in essentially all domains starting around age 50-60 and neurodegeneration and dementia seem to be inevitable in all but a few who survive to very old age. Mice with a fraction of the human lifespan show similar cognitive deterioration indicating that specific biological processes rather than time alone are responsible for brain aging. While age-related cognitive dysfunction and dementia in humans are clearly distinct entities and affect different brain regions the aging brain shows the telltale molecular and cellular changes that characterize most neurodegenerative diseases including synaptic loss, dysfunctional autophagy, increased inflammation, and protein aggregation. Remarkably, the aging brain remains plastic and exercise or dietary changes can increase cognitive function in humans and animals, with animal brains showing a reversal of some of the aforementioned biological changes associated with aging. Using heterochronic parabiosis we showed recently that blood-borne factors present in the systemic milieu can inhibit or promote adult neurogenesis in an age-dependent fashion in mice. Accordingly, exposing an old mouse to a young systemic environment or to plasma from young mice increased neurogenesis, synaptic plasticity, and improved contextual fear conditioning and spatial learning and memory. Over the past three years we discovered that factors in blood can actively change the number of new neurons that are being generated in the brain and that local cells in areas were neurons are generated respond to cues from the blood. We have started to identify some of these factors and hope they will allow us to regulate the activity of neural stem cells in the brain and hopefully improve cognition in diseases such as Alzheimer's.

Molecular basis of plasma membrane characteristics reflecting stem cell fate potential

Funding Type: 
Basic Biology V
Grant Number: 
RB5-07254
ICOC Funds Committed: 
$1 003 590
Disease Focus: 
Neurological Disorders
Stem Cell Use: 
Adult Stem Cell
oldStatus: 
Closed
Public Abstract: 
Stem cells generate mature, functional cells after proteins on the cell surface interact with cues from the environment encountered during development or after transplantation. Thus, these cell surface proteins are critical for directing transplanted stem cells to form appropriate cells to treat injury or disease. A key modification regulating cell surface proteins is glycosylation, which is the addition of sugars onto proteins and has not been well studied in neural stem cells. We focus on a major unsolved problem in the neural stem cell field: do different proteins coated with sugars on the surfaces of cells in this lineage (neuron precursors, NPs and astrocyte precursors, APs) determine what types of mature cells will form? We hypothesize key players directing cellular decisions are glycosylated proteins controlling how precursors respond to extracellular cues. We will address this hypothesis with aims investigating whether (1) glycosylation pathways predicted to affect cell surface proteins differ between NPs and APs, (2) glycosylated proteins on the surface of NPs and APs serve as instructive cues governing fate or merely mark their fate potential, and (3) glycosylation pathways regulate cell surface proteins likely to affect fate choice. By answering these questions we will better understand the formation of NPs and APs, which will improve the use of these cells to treat brain and spinal cord diseases and injuries.
Statement of Benefit to California: 
The goal of this project is to determine how cell surface proteins differ between cells in the neural lineage that form two types of final, mature cells (neurons and astrocytes) in the brain and spinal cord. In the course of these studies, we will uncover specific properties of human stem cells that are used to treat neurological diseases and injuries. We expect this knowledge will improve the use of these cells in transplants by enabling more control over what type of mature cell will be formed from transplanted cells. Also, cells that specifically generate either neurons or astrocytes can be used for drug testing, which will help to predict the effects of compounds on cells in the human brain. We hope our research will greatly improve identification, isolation, and utility of specific types of human neural stem cells for treatment of human conditions. Furthermore, this project will generate new jobs for high-skilled workers and, hopefully, intellectual property that will contribute to the economic growth of California.

CIRM Tissue Collection for Neurodevelopmental Disabilities

Funding Type: 
Tissue Collection for Disease Modeling
Grant Number: 
IT1-06611
ICOC Funds Committed: 
$874 135
Disease Focus: 
Neurological Disorders
Pediatrics
Cell Line Generation: 
iPS Cell
oldStatus: 
Active
Public Abstract: 
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.
Statement of Benefit to 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.

Human iPSC modeling and therapeutics for degenerative peripheral nerve disease

Funding Type: 
New Faculty Physician Scientist
Grant Number: 
RN3-06530
ICOC Funds Committed: 
$3 031 737
Disease Focus: 
Neuropathy
Neurological Disorders
Stem Cell Use: 
iPS Cell
Cell Line Generation: 
iPS Cell
oldStatus: 
Active
Public Abstract: 
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.
Statement of Benefit to California: 
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.
Progress Report: 
  • 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.

Modeling disease in human embryonic stem cells using new genetic tools

Funding Type: 
Basic Biology IV
Grant Number: 
RB4-05855
ICOC Funds Committed: 
$1 387 800
Disease Focus: 
Neuropathy
Neurological Disorders
Stem Cell Use: 
Embryonic Stem Cell
oldStatus: 
Active
Public Abstract: 
The use of stem cells or stem cell-derived cells to treat disease is one important goal of stem cell research. A second, important use for stem cells is the creation of cellular models of human development and disease, critical for uncovering the molecular roots of illness and testing new drugs. However, a major limitation in achieving these goals is the difficulty in manipulating human stem cells. Existing means of generating genetically modified stem cells are not ideal, as they do not preserve the normal gene regulation, are inefficient, and do not permit removal of foreign genes. We have developed a method of genetically modifying mouse embryonic stem cells that is more efficient than traditional methods. We are adapting this approach for use with human embryonic stem cells, so that these cells can be better understood and harnessed for modeling, or even treating, human diseases. We will use this approach to create a human stem cell model of Charcot-Marie-Tooth (CMT) disease, an inherited neuropathy. How gene dysfunction leads to nerve defects in CMT is not clear, and there is no cure or specific therapy for this neurological disease. Thus, we will use our genetic tools to investigate how gene function is disrupted to cause CMT. By developing these tools and using them to gain understanding of CMT, we will illustrate how this system can be used to gain insight into other important diseases.
Statement of Benefit to California: 
Although human stem cells hold the potential to generate new understanding about human biology and new approaches to important diseases, the inability to efficiently and specifically modify stem cells currently limits the pace of research. Also, there is presently no safe means of changing genes compatible with the use of the stem cells in therapies. We are developing new genetic tools to allow for the tractable manipulation of human stem cells. By accelerating diverse other stem cell research projects, these tools will enhance the scientific and economic development of California. We will use these tools to create cellular models of Charcot-Marie-Tooth (CMT), a neurological disease with no cure that affects about 15,000 Californians. This model will facilitate understanding of the etiology of CMT, and may lead to insights that can be used to develop specific therapies. Beyond gaining insight into CMT, the ability to engineer specific genetic changes in human stem cells will be useful for many applications, including the creation of replacement cells for personalized therapies, reporter lines for stem cell-based drug screens, and models of other diseases. Thus, our research will assist the endeavors of the stem cell community in both the public and private arenas, contributing to economic growth and new product development. This project will also train students and postdoctoral scholars in human stem cell biology, who will contribute to the economic capacity of California.
Progress Report: 
  • An important use for stem cells is the creation of cellular models of human development and disease, critical for uncovering the molecular roots of illness and testing new drugs. However, a major limitation in achieving these goals is the difficulty in manipulating human stem cells. We have developed a method of genetically modifying mouse embryonic stem cells that is more efficient than traditional methods. During the first year of this project, we adapted this approach for use with human embryonic stem cells. We have also created gene trap mutations in a diversity of human embryonic stem cell genes that can be used to better harness human embryonic stem cells for modeling, or even treating, human diseases.

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