Liver Disease

Coding Dimension ID: 
301
Coding Dimension path name: 
Liver Disease
Funding Type: 
Early Translational IV
Grant Number: 
TR4-06809
Investigator: 
Type: 
PI
ICOC Funds Committed: 
$2 322 440
Disease Focus: 
Blood Disorders
Liver Disease
Pediatrics
Stem Cell Use: 
iPS Cell
Cell Line Generation: 
iPS Cell
oldStatus: 
Closed
Public Abstract: 

Hemophilia B is a bleeding disorder caused by the lack of FIX in the plasma and affects 1/30,000 males. Patients suffer from recurrent bleeds in soft tissues leading to physical disability in addition to life threatening bleeds. Current treatment (based on FIX infusion) is transient and plagued by increased risk for blood-borne infections (HCV, HIV), high costs and limited availability. This has fueled a search for gene/cell therapy based alternatives. Being the natural site of FIX synthesis, the liver is expected to provide immune-tolerance and easy circulatory access. Liver transplantation is a successful, long-term therapeutic option but is limited by scarcity of donor livers and chronic immunosuppression; making iPSC-based cell therapy an attractive prospect. As part of this project, we plan to generate iPSCs from hemophilic patients that will then be genetically corrected by inserting DNA capable of making FIX. After validation for correction, we will then differentiate these iPSCs into liver cells that can be transplanted into our mouse model of hemophilia that is capable of accepting human hepatocytes and allowing their proliferation. These mice exhibit disease symptoms similar to human patients and we propose that by injecting our corrected liver cells they will exhibit normal clotting as measured by various biochemical and physiological assays. If successful, this will provide a long-term cure for hemophilia and other liver diseases.

Statement of Benefit to California: 

Generation of iPSCs from adult cells unlocked the potential of tissue engineering, replacement and cell transplant therapies to cure a host of debilitating diseases without the ethical concerns of working with embryos or the practical problems of immune-rejection. We aim to develop a POC for a novel cell- and gene-therapy based approach towards the treatment of hemophilia B. In addition to the obvious and direct benefit to the affected patients and families by providing a potential long-term cure; the successful development of our proposal will serve as a POC for moving other iPSC-based therapies to the clinic. Our proposal also has the potential to treat a host of other hepatic diseases like alpha-1-antitrypsin deficiency, Wilson’s disease, hereditary hypercholesterolemia, etc. These diseases have devastating effects on the patients in addition to the huge financial drain on the State in terms of the healthcare costs. There is a pressing need to find effective solutions to such chronic health problems in the current socio-economic climate. The work proposed here seeks to redress this by developing cures for diseases that, if left untreated, require substantial, prolonged medical expenditures and cause increased suffering to patients. Being global leaders in these technologies, we are ideally suited to this task, which will establish the state of California at the forefront of medical breakthroughs and strengthen its biomedical/biotechnology industries.

Progress Report: 
  • Hemophilia B is a bleeding disorder caused by the lack of FIX in the plasma and affects 1 in 30,000 males. Patients suffer from recurrent bleeds in soft tissues leading to physical disability in addition to life threatening bleeds. Current treatment (based on FIX infusion) is transient and plagued by increased risk for blood-borne infections (HCV, HIV), high costs and limited availability. This has fueled a search for gene/cell therapy based alternatives. Gene therapy with viruses is beset with problems of safety and increased immunogenicity. Being the natural site of FIX synthesis, the liver is expected to provide immune-tolerance and easy circulatory access. Liver transplantation is a successful, long-term therapeutic option but is limited by scarcity of donor livers and chronic immunosuppression, making iPSC-based cell therapy an attractive prospect. As part of this project, we will generate iPSCs from hemophilic patients that will be genetically corrected by inserting FIX coding DNA. After correction, we will differentiate these iPSCs into liver cells which will then be transplanted into our mouse model of hemophilia that can accept human hepatocytes and allow their proliferation. These mice exhibit disease symptoms similar to human patients and we propose that by injecting our corrected liver cells they will exhibit normal clotting as measured by various biochemical and physiological assays. If successful, this will provide a long-term cure for hemophilia and will serve as a proof-of-concept for the treatment of other liver diseases.
  • With this long term aim, during the first year of the project, we have procured two hemophilic patient samples and two control samples from our collaborators. We have successfully generated iPSCs with no long-term genomic changes. We are currently working towards identifying the mutations in the patients that were responsible for the disease. Our efforts are presently directed towards correcting the mutations in the patient derived iPSCs so that they can now produce a functional FIX protein.
Funding Type: 
Early Translational III
Grant Number: 
TR3-05542
Investigator: 
ICOC Funds Committed: 
$1 544 170
Disease Focus: 
Liver Disease
Collaborative Funder: 
China
Stem Cell Use: 
Directly Reprogrammed Cell
oldStatus: 
Active
Public Abstract: 

Although the liver can regenerate itself, chronic or overwhelming damage can cause life-threatening liver failure. Currently, the only therapy for liver failure is liver transplantation. Because the supply of cadaveric livers or liver tissue from living donors far exceeds the demand, physicians and researchers seek to develop new therapies to save the lives of patients with liver failure. One promising strategy is transplantation of hepatocytes, the cells of the liver that provide most of its functions and that are defective in liver failure. To make hepatocyte transplantation available to all patients who could benefit, a cell source other than scarce donor livers has to be established. In contrast to hepatocytes, skin cells can be readily obtained and expanded in culture. Therefore, the recent discovery that skin cells can be converted into hepatocytes by transfer of a few genes suggests a promising new source of hepatocytes. To develop transplantation of such cells as a therapy for liver failure, we aim to identify which readily available human cell type—skin, blood or fat cells—can be most efficiently converted into hepatocytes using methods of temporary gene transfer. Importantly, the therapeutic efficacy and safety of these induced hepatocytes will be rigorously tested in animal models of human liver failure. If successful, our project will establish the feasibility of therapy of liver failure with cells derived from a patient’s own readily available non-liver cells.

Statement of Benefit to California: 

Like in most states in the US, the number of Californians in need of a liver transplant significantly exceeds the number of available donor organs. Most of these patients have liver cirrhosis due to hepatitis C infection, alcoholic liver disease or cholestatic diseases. Other indications for liver transplantation include acute liver failure, hepatitis B virus infection, metabolic liver diseases and cancer. While the incidence of these liver diseases has been relatively stable, non-alcoholic steatohepatitis (NASH), which was first described only 10 years ago, is rapidly emerging and predicted to become the leading indication for liver transplantation in the future. Because Hispanics have an increased risk of developing NASH, California, the state with the largest Hispanic population in the US, will be particularly impacted by this epidemic. Thus, developing an abundant source of cells for liver cell therapy, as proposed in this project, will not only benefit the Californians currently awaiting liver transplantation, but may also help the state’s medical system to respond to this future challenge.

Progress Report: 
  • The overall goal of this project is to generate safe and therapeutically effective human induced hepatocyte-like cells from readily accessible cell sources like skin, fat or blood cells. In the first year of this project we have identified genetic factors effective in inducing hepatocyte differentiation of skin and fat cells. We have also identified genetic factors that allow the expansion of these induced hepatocyte-like cells. In addition, we have identified chemical factors that promote the function of human induced hepatocyte-like cells.
  • The objective of this project is to establish the feasibility of liver cell therapy with human induced hepatocyte-like cells (iHeps). As proposed we established the feasibility of generating iHeps from several expandable, potentially autologous human cell types. We identified transcription factors effective in inducing hepatocyte differentiation as well as further maturation of these cells. We also identified small molecules and culture conditions (extracellular matrix composition and stiffness) that promote proliferation and hepatocyte-specific differentiation. The next steps are to investigate the genomic integrity and therapeutic efficacy of these cells.
Funding Type: 
Early Translational IV
Grant Number: 
TR4-06831
Investigator: 
ICOC Funds Committed: 
$1 801 629
Disease Focus: 
Liver Disease
Genetic Disorder
Pediatrics
Stem Cell Use: 
iPS Cell
Cell Line Generation: 
iPS Cell
oldStatus: 
Active
Public Abstract: 

Liver transplantation (LT) has been used to treat a variety of liver diseases. Within hours after birth, neonates can present with disorders of the urea cycle (UCDs), the critical metabolic liver pathway needed to detoxify waste nitrogen from the diet and cellular turnover. The overall incidence of UCDs is estimated to be 1 in 8200 births. An increase in ammonia concentrations is particularly toxic to the central nervous system (CNS), causing brain edema, with multiple episodes affecting survival and often resulting in mental retardation and cerebral palsy. While LT is recommended in neonatal-onset patients with these single-enzyme defects, organ availability is a major limitation and transplantation requires lifelong immunosuppression. In addition, transplant morbidity and mortality are not inconsequential: 1-year survival is about 91.9%, and 5-year survival in children transplanted at less than 5 kg is 74%. Transplantation of genetically corrected embryonic stem cell-derived hepatocytes from the affected patients themselves is a potential way to replace LT for the treatment of metabolic liver disease and will likely not require immunosuppression; importantly, the supply will be limitless, allowing early transplantation before CNS injury. We propose to explore this approach by using a new and robust liver repopulation UCD mouse to advance this therapy: treatment of single-enzyme liver defects with patient-derived and genetically corrected stem cell-induced liver cells.

Statement of Benefit to California: 

Unfortunately there is a substantial wait for people in California who need a liver transplant, resulting in many who develop significant disability or die while waiting. While many are adults with chronic disease, some are children with metabolic disorders including urea cycle disorders (UCDs).

UCDs are caused by mutations resulting in enzyme deficiencies responsible for removing waste nitrogen, which as ammonia can cause irreversible brain damage, coma and/or death. Newborns can become catastrophically ill within 36-48 hours after birth. These and other inborn errors represent a substantial cause of brain damage and death among newborns and infants and because many cases remain undiagnosed, or infants with the disorders die without a definitive diagnosis, the exact incidence is unknown and likely underestimated.

Present treatment is dietary for most which is onerous & incomplete; definitive therapy is liver transplantation which is challenging in infants who have greater rates of complications and morbidity. In this proposal we will develop genetically-corrected hepatocyte-like cells from induced pluripotent stem cells from patients with arginase deficiency, a UCD. These will be tested for the ability to correct the disorder in a unique UCD liver repopulation animal model. The advantage of the proposed methodology over current therapy is that genetically-corrected cells will be limitless and will require no major surgery or immunosuppression and its short- & long-term risks.

Progress Report: 
  • The long-term objective of this multidisciplinary program is to develop a gene-corrected induced pluripotent stem cell-derived hepatocyte transplantation approach for clinical trials in children to replace the deficiency of single-enzyme defects in urea cycle disorders (UCDs) and other single-enzyme deficiencies that affect the liver. At present, liver transplantation for UCDs replaces a liver that is normal architecturally and in all other aspects except for a single enzyme. It is believed that establishing enzyme function to 10% or less in many of these disorders may result in a cure.
  • We are performing studies reprogramming of skin fibroblasts from human patients with UCDs into induced pluripotent stem cells followed by a gene addition approach and subsequent differentiation into functional hepatocytes. These human cells will be transplanted into a mouse model with a urea cycle disorder to demonstrate proof-of-principle enzyme replacement, define cell dose to replace enzyme activity to low normal levels, and characterize cell behavior after transplantation. These studies will serve as a preclinical proof of concept for a potential development candidate for a currently unmet need by using corrected and differentiated derivatives of a patient's induced pluripotent stem cells for neonatal and juvenile hepatic regenerative medicine.
  • In the first year of this award, we have obtained three human skin samples/fibroblasts from patients with a urea cycle disorder. We have gone through the regulatory process at our institution and completed all approvals related to stem cells. We have been developing induced pluripotent stem cells from the first two lines and also a control line. We require characterization of these stem cells by gene studies and by demonstrating that they can turn into all three germ layers; some of these studies have been completed and others are in process. We have prepared adequate stocks of these fibroblasts and induced pluripotent stem cells for these ongoing studies. We have been developing what we believe will be a safe approach to adding a gene; in this way supplying the correct copy of the abnormal gene to treat the disorder. We are developing this as a universal method of gene addition. That is, one that could be used for all of the urea cycle disorders and for other disorders of the liver such as maple syrup urine disease, alpha1-antitrypsin, and others. Our data suggests that have been able to successfully target this "safe" site for gene integration; further studies are in progress to prove this finding. We have also examined for gene expression of the urea cycle disorder gene that is being corrected in both our gene-corrected control cell line and in our first gene-corrected human patient disease-specific cell line. Both have demonstrated expression of the gene. We are now working to demonstrate that the gene is present at the correct location and that it is functional in that it is producing protein to correct this disorder.
Funding Type: 
hiPSC Derivation
Grant Number: 
ID1-06557
Investigator: 
Type: 
PI
ICOC Funds Committed: 
$16 000 000
Disease Focus: 
Developmental Disorders
Genetic Disorder
Heart Disease
Infectious Disease
Alzheimer's Disease
Neurological Disorders
Autism
Respiratory Disorders
Vision Loss
Liver Disease
Cell Line Generation: 
iPS Cell
oldStatus: 
Active
Public Abstract: 

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.

Statement of Benefit to California: 

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.

Progress Report: 
  • 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.
Funding Type: 
Tissue Collection for Disease Modeling
Grant Number: 
IT1-06563
Investigator: 
ICOC Funds Committed: 
$865 370
Disease Focus: 
Liver Disease
Infectious Disease
Stem Cell Use: 
iPS Cell
oldStatus: 
Active
Public Abstract: 

Hepatitis C and fatty liver disease are the two most common liver diseases in California. Individuals from different backgrounds are susceptible to these liver diseases, but they have unique genetic profiles that may influence the severity of disease and the response to specific therapies. Technology now makes it possible to generate stem cells from a person’s own skin. These cells can subsequently be used to generate liver cells identical to those from the original donor. Using this approach, scientists can perform research directly on an individual’s own liver cells to identify features that make the cells susceptible or resistant to disease and drug therapy. In this project, the research team will collect blood and skin tissue from people with liver disease and from healthy control subjects. The donated tissues will be placed in a "bank" for the production of stem cells. The overall goal is for the donated cells to be made available to scientists who will convert them to liver cells, and then carefully study them to learn more about liver disease. Research such as this is extremely valuable because it allows patients and volunteers to make a very personal contribution to the understanding of liver disease. The materials donated to this tissue "bank" will be a resource to the scientific community for many years.

Statement of Benefit to California: 

Hepatitis C and fatty liver disease are the two most common liver diseases affecting the citizens of California. Together they afflict one in every 12 people in the state and kill roughly 4,000 state residents each year. Researchers in California are actively seeking new information about the causes of and treatments for liver disease; their progress will be greatly accelerated by the opportunity to directly study the biology of diseased patients. The goal of this project is to build a "bank" of stem cells from local patients with liver disease. Patient donors will come from many different backgrounds, reflecting the great diversity of California. The bank, once established, will be a tremendous resource for medical research because the banked cells will be renewable and made available to the entire research community. Banked stem cells will enable researchers to study the genetics and biology of liver disease and to test new therapies. Importantly, they will give researchers an opportunity to study liver disease in its most important context - the affected patient. The research made possible through this effort will greatly enhance our understanding of liver disease; this will in turn reduce the negative impact of liver disease on the health and well-being of California residents.

Progress Report: 
  • The goal of this project is to collect blood or skin tissues from subjects with liver disease to learn more about the factors that predispose individuals to their conditions. We are focusing our attention on subjects with two specific liver diseases: hepatitis C and non-alcoholic steatohepatitis (the latter is termed "NASH" or "fatty liver disease"). These are the two most common causes of liver disease in California. In the case of hepatitis C, research to date shows that factors such as race, genetic makeup and immunologic makeup influence individual responses to infection by the hepatitis C virus as well as responses to antiviral drug treatment. Our goal is to recruit individuals with diverse backgrounds and responses to hepatitis C infection and treatment, to enable scientists to identify the determinants of susceptibility or resistance to hepatitis C-related liver disease. In the case of fatty liver disease, we are recruiting subjects who have significant liver injury due to the accumulation of fat, proven on a liver biopsy (NASH). NASH is typically found in subjects who are overweight, and who often have additional health problems such as high blood pressure, high cholesterol and diabetes. We are also looking for subjects who are at risk for NASH and have prominent fat accumulation in the liver on a biopsy, but have no evidence of actual liver injury. As with hepatitis C, the goal with fatty liver disease is to accumulate a cohort of subjects with diverse backgrounds and a spectrum of disease severity, to enable scientists to determine the factors that predispose some individuals at risk to serious liver disease while sparing others.
Funding Type: 
hPSC Repository
Grant Number: 
IR1-06600
Investigator: 
ICOC Funds Committed: 
$9 999 834
Disease Focus: 
Developmental Disorders
Heart Disease
Infectious Disease
Alzheimer's Disease
Neurological Disorders
Autism
Respiratory Disorders
Vision Loss
Liver Disease
Epilepsy
Stem Cell Use: 
iPS Cell
Cell Line Generation: 
iPS Cell
oldStatus: 
Active
Public Abstract: 

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.

Statement of Benefit to California: 

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.

Progress Report: 
  • 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.
Funding Type: 
Tools and Technologies II
Grant Number: 
RT2-02060
Investigator: 
Institution: 
Type: 
PI
ICOC Funds Committed: 
$1 869 487
Disease Focus: 
Blood Disorders
Heart Disease
Liver Disease
Stem Cell Use: 
Embryonic Stem Cell
iPS Cell
oldStatus: 
Active
Public Abstract: 

Purity is as important for cell-based therapies as it is for treatments based on small-molecule drugs or biologics. Pluripotent stem cells possess two properties: they are capable of self regeneration and they can differentiate to all different tissue types (i.e. muscle, brain, heart, etc.). Despite the promise of pluripotent stem cells as a tool for regenerative medicine, these cells cannot be directly transplanted into patients. In their undifferentiated state they harbor the potential to develop into tumors. Thus, tissue-specific stem cells as they exist in the body or as derived from pluripotent cells are the true targets of stem cell-based therapeutic research, and the cell types most likely to be used clinically. Existing protocols for the generation of these target cells involve large scale differentiation cultures of pluripotent cells that often produce a mixture of different cell types, only a small fraction of which may possess therapeutic potential. Furthermore, there remains the real danger that a small number of these cells remains undifferentiated and retains tumor-forming potential. The ideal pluripotent stem cell-based therapeutic would be a pure population of tissue specific stem cells, devoid of impurities such as undifferentiated or aberrantly-differentiated cells.
We propose to develop antibody-based tools and protocols to purify therapeutic stem cells from heterogeneous cultures. We offer two general strategies to achieve this goal. The first is to develop antibodies and protocols to identify undifferentiated tumor-forming cells and remove them from cultures. The second strategy is to develop antibodies that can identify and isolate heart stem cells, and blood-forming stem cells capable of engraftment from cultures of pluripotent stem cells. The biological underpinning of our approach is that each cell type can be identified by a signature surface marker expression profile.
Antibodies that are specific to cell surface markers can be used to identify and isolate stem cells using flow cytometry. We can detect and isolate rare tissue stem cells by using combinations of antibodies that correspond to the surface marker signature for the given tissue stem cell. We can then functionally characterize the potential of these cells for use in regenerative medicine.
Our proposal aims to speed the clinical application of therapies derived from pluripotent cell products by reducing the risk of transplanting the wrong cell type - whether it is a tumor-causing residual pluripotent cell or a cell that is not native to the site of transplant - into patients. Antibodies, which exhibit exquisitely high sensitivity and specificity to target cellular populations, are the cornerstone of our proposal. The antibodies (and other technologies and reagents) identified and generated as a result of our experiments will greatly increase the safety of pluripotent stem cell-derived cellular therapies.

Statement of Benefit to California: 

Starting with human embryonic stem cells (hESC), which are capable of generating all cell types in the body, we aim to identify and isolate two tissue-specific stem cells – those that can make the heart and the blood – and remove cells that could cause tumors. Heart disease remains the leading cause of mortality and morbidity in the West. In California, 70,000 people die annually from cardiovascular diseases, and the cost exceeded $48 billion in 2006. Despite major advancement in treatments for patients with heart failure, which is mainly due to cellular loss upon myocardial injury, the mortality rate remains high. Similarly, diseases of the blood-forming system, e.g. leukemias, remain a major health problem in our state.
hESC and induced pluripotent stem cells (collectively, pluripotent stem cells, or PSC) could provide an attractive therapeutic option to treat patients with damaged or defective organs. PCS can differentiate into, and may represent a major source of regenerating, cells for these organs. However, the major issues that delay the clinical translation of PSC derivatives include lack of purification technologies for heart- or blood-specific stem cells from PSC cultures and persistence of pluripotent cells that develop into teratomas. We propose to develop reagents that can prospectively identify and isolate heart and blood stem cells, and to test their functional benefit upon engraftment in mice. We will develop reagents to identify and remove residual PSC, which give rise to teratomas. These reagents will enable us to purify patient-specific stem cells, which lack cancer-initiating potential, to replenish defective or damaged tissue.
The reagents generated in these studies can be patented forming an intellectual property portfolio shared by the state and the institutions where the research is carried out. The funds generated from the licensing of these technologies will provide revenue for the state, will help increase hiring of faculty and staff (many of whom will bring in other, out-of-state funds to support their research) and could be used to ameliorate the costs of clinical trials – the final step in translation of basic science research to clinical use. Only California businesses are likely to be able to license these reagents and to develop them into diagnostic and therapeutic entities; such businesses are at the heart of the CIRM strategy to enhance the California economy. Most importantly, this research will set the platform for future stem cell-based therapies. Because tissue stem cells are capable of lifelong self-renewal, stem cell therapies have the potential to be a single, curative treatment. Such therapies will address chronic diseases with no cure that cause considerable disability, leading to substantial medical expense. We expect that California hospitals and health care entities will be first in line for trials and therapies. Thus, California will benefit economically and it will help advance novel medical care.

Progress Report: 
  • Our program is focused on improving methods that can be used to purify stem cells so that they can be used safely and effectively for therapy. A significant limitation in translating laboratory discoveries into clinical practice remains our inability to separate specific stem cells that generate one type of desired tissue from a mixture of ‘pluripotent’ stem cells, which generate various types of tissue. An ideal transplant would then consist of only tissue-specific stem cells that retain a robust regenerative potential. Pluripotent cells, on the other hand, pose the risk, when transplanted, of generating normal tissue in the wrong location, abnormal tissue, or cancer. Thus, we have concentrated our efforts to devise strategies to either make pluripotent cells develop into desired tissue-specific stem cells or to separate these desired cells from a mixture of many types of cells.
  • Our approach to separating tissue-specific stem cells from mixed cultures is based on the theory that every type of cell has a very specific set of molecules on its surface that can act as a signature. Once this signature is known, antibodies (molecules that specifically bind to these surface markers) can be used to tag all the cells of a desired type and remove them from a mixed population. To improve stem cell therapy, our aim is to identify the signature markers on: (1) the stem cells that are pluripotent or especially likely to generate tumors; and (2) the tissue-specific stem cells. By then developing antibodies to the pluripotent or tumor-causing cells, we can exclude them from a group of cells to be transplanted. By developing antibodies to the tissue-specific stem cells, we can remove them from a mixture to select them for transplantation. For the second approach, we are particularly interested in targeting stem cells that develop into heart (cardiac) tissue and cells that develop into mature blood cells. As we develop ways to isolate the desired cells, we test them by transplanting them into animals and observing how they grow.
  • Thus, the first goal of our program is to develop tools to isolate pluripotent stem cells, especially those that can generate tumors in transplant recipients. To this end, we tested an antibody aimed at a pluripotent cell marker (stage-specific embryonic antigen-5 [SSEA-5]) that we previously identified. We transplanted into animals a population of stem cells that either had the SSEA-5-expressing cells removed or did not have them removed. The animals that received the transplants lacking the SSEA-5-expressing cells developed smaller and fewer teratomas (tumors consisting of an abnormal mixture of many tissues). Approaching the problem from another angle, we analyzed teratomas in animals that had received stem cell transplants. We found SSEA-5 on a small group of cells we believe to be responsible for generating the entire tumor.
  • The second goal of the program is to develop methods to selectively culture cardiac stem cells or isolate them from mixed cultures. Thus, in the last year we tested procedures for culturing pluripotent stem cells under conditions that cause them to develop into cardiac stem cells. We also tested a combination of four markers that we hypothesized would tag cardiac stem cells for separation. When these cells were grown under the proper conditions, they began to ‘beat’ and had electrical activity similar to that seen in normal heart cells. When we transplanted the cells with the four markers into mice with normal or damaged hearts, they seemed to develop into mature heart cells. However, these (human) cells did not integrate with the native (mouse) heart cells, perhaps because of the species difference. So we varied the approach and transplanted the human heart stem cells into human heart tissue that had been previously implanted in mice. In this case, we found some evidence that the transplanted cells differentiated into mature heart cells and integrated with the surrounding human cells.
  • The third goal of our project is to culture stem cells that give rise only to blood cells and test them for transplantation. In the past year, we developed a new procedure for treating cultures of pluripotent stem cells so that they differentiate into specific stem cells that generate blood cells and blood vessels. We are now working to refine our understanding and methods so that we end up with a culture of differentiated stem cells that generates only blood cells and not vessels.
  • In summary, we have discovered markers and tested combinations of antibodies for these markers that may select unwanted cells for removal or wanted cells for inclusion in stem cell transplants. We have also begun to develop techniques for taking a group of stem cells that can generate many tissue types, and growing them under conditions that cause them to develop into tissue-specific stem cells that can be used safely for transplantation.
  • Our program is focused on improving methods to purify blood-forming and heart-forming stem cells so that they can be used safely and effectively for therapy. Current methods to identify and isolate blood-forming stem cells from bone marrow and blood are efficient. In addition, we found that if blood-forming stem cells are transplanted, they create in the recipient an immune system that will tolerate (i.e., not reject) organs, tissues, or other types of tissue stem cells (e.g. skin, brain, or heart) from the same donor. Many living or recently deceased donors often cannot contribute these stem cells, so we need, in the future, a single biological source of each of the different types of stem cells (e.g., blood and heart) to change the entire field of regenerative medicine. The ultimate reason to fund embryonic stem cell and other pluripotent stem cell research is to create safe banks of predefined pluripotent cells. Protocols to differentiate these cells to the appropriate blood-forming stem cells could then be used to induce tolerance of other tissue stem cells from the same embryonic stem cell line. However, existing protocols to differentiation stem cells often lead to pluripotent cells (cells that generate multiple types of tissue), which pose a risk of generating normal tissue in the wrong location, abnormal tissue, or cancers called teratomas. To address these problems, we have concentrated our efforts to devise strategies to (a) make pluripotent cells develop into desired tissue-specific stem cells, and (b) to separate these desired cells from all other cells, including teratoma-causing cells. In the first funding period of this grant, we succeeded in raising antibodies that identify and eliminate teratoma-causing cells.
  • In the past year, we identified surface markers of cells that can only give rise to heart tissue. First we studied the genes that were activated in these cells, further confirming that they would likely give rise to heart tissue. Using antibodies against these surface markers, we purified heart stem cells to a higher concentration than has been achieved by other purification methods. We showed that these heart stem cells can be transplanted such that they integrate into the human heart, but not mouse heart, and participate in strong and correctly timed beating.
  • In the embryo, a group of early stem cells in the developing heart give rise to (a) heart cells; (b) cells lining the inner walls of blood vessels; and (c) muscle cells surrounding blood vessels. We identified cell surface markers that could be used to separate each of these subsets from each other and from their common stem cell parents. Finally, we determined that a specific chemical in the body, fibroblast growth factor, increased the growth of a group of pluripotent stem cells that give rise to more specific stem cells that produce either blood cells or the lining of blood vessels. This chemical also prevented blood-forming stem cells from developing into specific blood cells.
  • In the very early embryo, pluripotent cells separate into three distinct categories called ‘germ layers’: the endoderm, mesoderm, and ectoderm. Each of these germ layers later gives rise to certain organs. Our studies of the precursors of mesoderm (the layer that generates the heart, blood vessels, blood, etc.) led us by exclusion to develop techniques to direct ES cell differentiation towards endoderm (the layer that gives rise to liver, pancreas, intestinal lining, etc.). A graduate student before performed most of this work before he joined in our effort to find ways to make functional blood forming stem cells from ES cells. He had identified a group of proteins that we could use to sequentially direct embryonic stem cells to develop almost exclusively into endoderm, then subsets of digestive tract cells, and finally liver stem cells. These liver stem cells derived from embryonic stem cells integrated into mouse livers and showed signs of normal liver tissue function (e.g., secretion of albumin, a major protein in the blood). Using the guidelines of the protocols that generated these liver stem cells, we have now turned our attention back to our goal of generating from mesoderm the predecessors of blood-forming stem cells, and, ultimately, blood-forming stem cells.
  • In summary, we have continued to discover signals that cause pluripotent stem cells (which can generate many types of tissue) to become tissue-specific stem cells that exclusively develop into only heart, blood cells, blood vessel lining cells, cells that line certain sections of the digestive tract, or liver cells. This work has also involved determining the distinguishing molecules on the surface of various cells that allow them to be isolated and nearly purified. These results bring us closer to being able to purify a desired type of stem cell to be transplanted safely to generate only a single type of tissue.
  • The main focus of our program is to improve methods to generate pure populations of tissue-specific stem cells that form only heart tissue or blood. Such tissue-specific stem cells are necessary for developing safe and effective therapies. If injected into patients with heart damage, heart-forming stem cells might be used to regenerate healthy heart tissue. Blood-forming stem cells are capable of regenerating the blood-forming system after cancer therapy and replacing a defective blood forming-system. We showed that blood-forming stem cells from a given donor induce in the recipient permanent transplant tolerance of all organs, tissues, or other tissue stem cells from the same donor. Therefore, having a single biological source of each of the different types of stem cells (e.g., blood and heart) would revolutionize regenerative medicine.
  • Our projects involve generating tissue-specific stem cells from pluripotent stem cells (PSCs), the latter of which are stem cells that can form all tissues of the body. PSCs (which include embryonic stem cells and induced pluripotent stem cells) can turn into all types of more specialized cells in a process known as “differentiation.” Because PSCs can be grown to very large numbers, differentiating PSCs into tissue-specific stem cells could lead to banks of defined tissue stem cells for transplantation into patients—the ultimate reason to conduct PSC research.
  • However, current methods to differentiate PSCs often generate mixtures of various cell types that are unsafe for injection into patients. Therefore, generating a pure population of a desired cell type from PSC is pivotal for regenerative medicine—purity is a key concern for cell therapy as it is with medications.
  • We have invented technologies to purify desired types of cells from complex cell populations, allowing us to precisely isolate a pure population of tissue-specific stem cells from differentiating PSCs for cell therapy. For instance, in our work on heart-forming cells, we developed labels for cells that progressively give rise to heart cells. We used these labeled cells to clarify the natural, stepwise, differentiation process that leads from PSCs to heart-forming stem cells, and finally to different cells within the heart. Exploiting these technologies to isolate desired cell types, we have completed the first step of turning human PSCs into heart-forming stem cells. In the laboratory, when we transplanted these heart-forming stem cells into a human heart, they integrated with the surrounding tissue and participated in correctly timed beating. In the future we hope to deliver heart-forming stem cells into the damaged heart to regenerate healthy tissue.
  • We have also attempted to turn PSCs into blood-forming stem cells by understanding the complex process of blood formation in the early embryo. As mentioned above, if blood-forming stem cells are transplanted into patients, they create in the recipient an immune system that will tolerate (i.e., not reject) other tissues and types of tissue stem cells (e.g., for skin or heart) from the same donor. Thus, turning PSCs into blood-forming stem cells will provide the basis for all regenerative medicine, whereby the blood-forming stem cells and the needed other tissue stem cells can be generated from the same pluripotent cell line and be transplanted together.
  • In parallel studies to those above, we have turned PSCs into liver-forming stem cells. In the embryo, the liver emerges from a cell type known as endoderm, whereas the blood and heart emerge from a different cell type known as mesoderm. We learned that PSCs could only be steered to form endoderm (and subsequently, liver) by diverting them away from the path that leads to mesoderm. Through this approach, we could turn human PSCs into endoderm cells (at >99% purity) and then into liver-forming stem cells that, when injected into the mouse liver, gave rise to human liver cells. This could be of therapeutic importance for human patients with liver damage.
  • Finally, we have developed methods to deplete PSCs from mixtures of cells differentiated from PSCs, because residual PSCs in these mixtures can form tumors (known as teratomas). These methods should increase the safety of PSC-derived tissue stem cell therapy.
  • In summary, we have developed methods to turn PSCs to tissue-specific stem cells that exclusively develop into only heart, blood cells, or liver cells. This work has involved determining the distinguishing molecules on the surface of various cells that allow them to be isolated and nearly purified. These results bring us closer to being able to purify a desired type of stem cell to be transplanted safely to generate only a single type of tissue.
Funding Type: 
New Faculty II
Grant Number: 
RN2-00950
Investigator: 
ICOC Funds Committed: 
$3 032 510
Disease Focus: 
Liver Disease
Stem Cell Use: 
Adult Stem Cell
Embryonic Stem Cell
oldStatus: 
Active
Public Abstract: 

The liver is a promising target for cell therapy since it supports and functionally integrates transplanted cells. Human liver contains more than 50 billion cells and more than 10% replacement will be required for most liver diseases. Hence, embryonic stem cells (ESC), which have unlimited growth capacities, represent one of the few cell types with potential for liver cell therapy. However, to be functionally effective and safe, ESC have to be differentiated into hepatocytes, the cells of the liver that provide its typical functions, before transplantation. Unfortunately, current ESC differentiation protocols generate cells that are not fully differentiated or functional. To achieve levels of differentiation that would be therapeutic we propose to identify the mechanisms that establish hepatocyte function in progenitor cells in the adult liver. Adult liver progenitors are typically absent from the normal liver but become apparent in liver disease when hepatocytes are damaged. Remarkably, adult liver progenitors can differentiate into fully functional hepatocytes within a few days. We hope to identify the genes that enable this rapid maturation process in order to apply it to immature cells derived from ESC. If maturation can be induced and these hepatocyte-like cells function to correct a mouse model of a human liver disease we will have provided proof-of-principle for the potential of ESC for liver cell therapy.

Statement of Benefit to California: 

Liver transplantation is the only curative option for patients with severe liver diseases. As donor livers are rare, many Californians are currently waiting to receive a transplant. In fact, many patients on the waiting list die before a donor organ becomes available. If successful, the proposed project would help to alleviate the need for donor organs by establishing embryonic stem cells as a source of hepatocytes for transplantation. As hepatocyte transplantation would be less invasive and expensive than orthotopic liver transplantation, funds might become available that could be used to benefit the citizens of California in other areas.

Progress Report: 
  • The overall goal of this project is to establish new strategies for liver regeneration. For this purpose, we aim at identifying molecular mechanisms regulating liver regeneration that could be exploited for therapeutic purposes. Along these lines, we have identified small RNAs that either promote or inhibit the proliferation of hepatocytes, the cells in the liver that provide its manifold functions. We are now working on developing tools to modify the levels of these small RNAs in the liver with the goal to enhance liver regeneration. In addition, we aim at developing hepatocyte replacement strategies for liver diseases that cause irreparable hepatocyte damage. We focus on immune-compatible pluripotent stem cells because they can in principle generate the large numbers of hepatocytes required for therapeutically effective cell therapy and would not require life-long immune suppression. We have established proof-of-principle for the therapeutic efficacy of hepatocytes derived from mouse pluripotent stem cells, and are now working towards recapitulating these results in human cells.
  • In the past year we have made several discoveries that move us closer to our goal to improve the proliferation and function and thus therapeutic efficacy of hepatocytes derived from pluripotent stem cells.
  • Some of these discoveries have elucidated the role of microRNAs, a class of non-coding small RNAs, in liver regeneration and function. For example, we found that miR-21 acts as a promoter of hepatocyte proliferation during liver regeneration. In addition, we identified several other microRNAs that establish differentiated function in hepatocytes.
  • Other discoveries of ours have revealed which type of pluripotent stem cell is best for liver cell therapy that does not require chronic immune suppression. Our results show that induced pluripotent stem cells derived from fibroblasts are as effective in reversing liver failure as normal hepatocytes.
  • In the last year we have made significant progress towards our goal of "Molecular dissection of adult liver regeneration to guide the generation of hepatocytes from pluripotent stem cells". We have identified the mechanism of how microRNA-21 promotes liver regeneration. We are currently working on translating this understanding into a therapeutic strategy for liver failure. We have also gained in-depth insight into the molecular regulation of differentiation of liver progenitor cells into hepatocytes. We have begun to use this insight to direct the differentiation of pluripotent stem cells into hepatocytes that are effective in liver cell therapy.
  • Being able to generate hepatocytes from human pluripotent stem cells would advance many important research efforts, including studies of the pathobiology of liver diseases and the development of liver cell therapies. Unfortunately, realizing this potential has been hampered by shortcomings of human hepatocyte-like cells (HLCs) generated with current in vitro-differentiation protocols, not only as it pertains to replicating the function of primary human hepatocytes, but also their ability to proliferate in vivo. We have made significant progress toward our goal of identifying regulators of hepatocyte differentiation. In addition, we have established the feasibility of liver repopulation of immune-deficient mice with HLCs generated in vitro, thereby proving their ability to mature and proliferate after transplantation
  • We have made significant progress toward our goal of generating in the laboratory human liver cells that are therapeutically effective in mouse models of human liver failure. Because these surrogate human liver cells can be derived from readily accessible cell types like skin cells, they have potential for autologous liver cell therapies requiring nor or little immune suppression. Much of this progress was afforded by insight into mouse liver development and regeneration obtained from the investigations performed under this grant.
  • The overall goal of the research funded by this award was to establish the feasibility of generating therapeutically effective human hepatocytes in the laboratory. Another goal was to generate these hepatocytes so that they would not require immune suppression after transplantation. For this we investigated how hepatocyte differentiation and proliferation are regulated in mice and humans and applied this insight for the directed differentiation of human fibroblasts fully or partially reprogrammed to pluripotency. Our results showed that human fibroblasts can be converted into cells that replicate both function and proliferation of primary human hepatocytes, thereby establishing the feasibility of autologous liver cell therapy not requiring immune suppression.
Funding Type: 
Tools and Technologies III
Grant Number: 
RT3-07670
Investigator: 
Type: 
PI
Type: 
Partner-PI
ICOC Funds Committed: 
$1 393 290
Disease Focus: 
Liver Disease
Collaborative Funder: 
Germany
Stem Cell Use: 
iPS Cell
Public Abstract: 

Liver failure is the fourth leading cause of adult death in California. Because liver cells can regenerate, some patients with liver failure could be saved without having to undergo organ transplantation if their liver function could be supported temporarily. Here, we propose to develop a device to support these patients called the “extracorporeal liver support system (ELS).”

Numerous pre-clinical studies and clinical trials have demonstrated the therapeutic effectiveness of ELS using human or animal liver cells housed in a device outside of the patient’s body but connected to the patient's circulation. The device removes toxins and prevents irreversible brain damage while the patient regenerates his or her own liver cells. However, the limited availability of human cells and insufficient functionality of animal cells prohibits this therapy from being widely adopted.

For this project, we will develop ELS using human stem cell-derived liver cells (hPSC-Hep) that will overcome two major bottlenecks in the translation of human stem cell therapies: scalability and safety. The unlimited supply and consistent quality of hPSC-Hep will allow us to make ELS scalable. By keeping the hPSC-Hep in a device separate from the patient’s body, we will also be able to allay any safety concerns about these cells forming tumors.

The result will be a widely available, safe and effective treatment that will alleviate the need for liver transplants for certain patients.

Statement of Benefit to California: 

Liver disease is a leading cause of death in California. California’s rate of 10.6 deaths per 100,000 people exceeds the national average of 8.8. To mitigate this problem, we propose developing a clinical device that can temporarily perform liver functions until a patient’s own liver cells recover. The device will use stem cells as a source of unlimited and quality controlled liver cells. Because the device is outside of the patient’s body, these stem cell-derived liver cells will remain separate from the patient’s blood stream, overcoming any risk of tumor formation. If successful, the device will be the leading choice for treatment, and will allow patients to recuperate without undergoing costly liver transplantation, which places an economic burden on patients' families as well as society.
Furthermore, the production of this device could constitute a novel industry that would provide job opportunities to the citizens of California. If successful, our industrial partner plans to launch a new California-based company in the near future.
The benefits of this new regenerative therapy will have a tremendous impact on the state of California and the thousands of patients suffering from liver diseases.

Funding Type: 
Early Translational III
Grant Number: 
TR3-05488
Investigator: 
Type: 
PI
ICOC Funds Committed: 
$1 750 375
Disease Focus: 
Liver Disease
Pediatrics
Stem Cell Use: 
Adult Stem Cell
oldStatus: 
Active
Public Abstract: 

Approximately 1 in 1,500 children has a congenital metabolic disorder. These inborn errors of metabolism are caused by deficiencies of different enzymes and result in accumulation of various substances inside cells. These substances affect the function of vital organs, and in many cases are lethal. Transplantation of cells that possess the particular deficient enzyme carries the potential to cure these diseases. Currently, a shortage of human liver cells for transplantation prohibits clinical use of this therapy. The human placenta contains cells that may acquire hepatic function. Following delivery of a baby, these cells can be collected from the placenta which is in most cases is treated as medical waste and discarded. The therapeutic potential of this cell type has been shown in animal models. We propose to first develop a method to separate these cells from non liver like cells, and secondly use these cells to treat multiple mouse models of human inborn errors of metabolism. We will also establish a clinically applicable small-scale preparatory Bio-banking system to provide immunotype-matched cells to patients affected by these diseases. These immunotype-matched cells can replace the missing enzyme function in patients who suffer from congenital liver metabolic disorders, and potentially will be cure the condition. Although this proposal focuses on the congenital liver metabolic disorders, success may lead to the use of these cells in other liver diseases.

Statement of Benefit to California: 

We propose to develop a technology to isolate and derive functional hepatic cells from discarded human placentae. The therapeutic cells will be utilized to treat congenital metabolic disorders. Current therapy for congenital metabolic disorders requires life-long treatment. It is easy to imagine how the economical burden afflicts the patients' families and society. If successful, immuotype matched hAEC-derived cell replacement therapy may completely cure some of the congenital metabolic disorders. The benefit of this new regenerative medicine will be tremendous not only for the patients' quality of life but also for our society. Although this proposal focuses on the congenital liver metabolic disorders, the target disease can potentially be extended to other liver diseases. This cell therapy would be the first cell therapy for liver disease and could benefit thousands of patients in California who suffer various liver diseases.
Furthermore, once this therapeutic potential is demonstrated, a placenta collection system, placental stem cell banking system, and a stem cell-derived hepatic cell distribution system might be a novel industry or industries that could provide job opportunities to the citizens of California.

Progress Report: 
  • We took human amniotic epithelial cells (hAECs) from placentae and isolated the cells with the enzyme activities that are lacking in three inherited metabolic disorders: mucopolysaccharidosis type I (MSP I, or Hurler syndrome), maple syrup urine disease and ornithine transcarbamylase deficiency (OTC). By transplanting these enzymatically-active cells into mice, we demonstrated an effective treatment for these disorders.
  • Our group and others have demonstrated that hAECs possess unique stem cell-like qualities, such as the ability to differentiate. More importantly, hAECs are genetically stable and therefore don’t form tumors upon transplantation in mice and humans.
  • During the first year of the project, we identified markers on the surface of hAECs that indicate the presence of the genes that code for the desired enzymes. We successfully established colonies of mice with each of the three metabolic disorders and defined the protocols for the radiological and biochemical tests, or assays. We also performed several hAEC transplantations to mice with MSP I.
  • The first case of hAEC transplantation demonstrated a very promising result: the pathologic protein concentration in the urine of the treated MSP I mouse was dramatically decreased. We will confirm this result by investigating it further in more mice.
  • As proposed, we have also started building a small-scale bio-bank of hAECs from 24 placentae. These hAECs will be used to determine whether hAECs retain their therapeutic potential after cryopreservation, or freezing.
  • In this reporting period we have conducted multiple analyses and accomplished several tasks. First, we successfully demonstrated therapeutic efficacy of placenta-derived stem cells (PDSCs) in all three proposed congenital metabolic disease model animals.
  • A lysosome disease model Idua deficient mouse was used to test therapeutic efficacy of the PDSC for systemic congenital metabolic diseases. We demonstrated that unfractionated PDSCs express IDUA mRNA and protein at equivalent or higher levels than human hepatocytes. PDSC transplanted mice demonstrated a 15.1% and 32.5% increase of IDUA enzyme activity in the liver and lung, respectively. Interestingly, brain IDUA activity drastically improved (96.5%). We also established quantitative and qualitative bone mass evaluation methods using micro CT. Although the therapeutic efficacy on the bone phenotype of IDUA mouse was limited, the recipient demonstrated slight improvement. This data indicated that our approach to target the largest internal organ, the liver, to treat systemic metabolic disorders was reasonable and efficient. We will further study the optimal condition of PDSC transplantation and the mechanism of cell therapy.
  • Our single cell gene expression analysis data indicated that the PDSC contains BCKDHa expressing cells. Using an intermediate Maple Syrup Urine disease model mouse, we conducted ultrasound guided cell injections to visualize transplanted cell distribution.
  • Previous data indicated that primary PDSCs do not express the OTC gene. We conducted unfractionated PDSC transplantation into Spf/Ash mouse, which is a disease model with OTC deficiency. The urine proteomic analysis data indicated that the PDSC transplantation clearly improved the OTC phenotype. We will further increase the number of recipient mice as well as test different dosages and frequencies of cell transplantation.
  • In conclusion, the project has been progressing very well and has demonstrated promising data in treating congenic metabolic disorder patients with placenta derived stem cells.

Pages