Heart Disease

Coding Dimension ID: 
295
Coding Dimension path name: 
Heart Disease

Human Embryonic Stem Cell-Derived Cardiomyocytes for Patients with End Stage Heart Failure

Funding Type: 
Disease Team Therapy Planning I
Grant Number: 
DR2-05394
ICOC Funds Committed: 
$108 895
Disease Focus: 
Heart Disease
oldStatus: 
Closed
Public Abstract: 
Patients with end-stage heart failure (ESHF) have a 2-year survival rate of 50% with conventional medical therapy. This dismal survival rate is actually significantly worse than patients with AIDS, liver cirrhosis, stroke, and other debilitating diseases. Stem cell therapy may be a promising strategy for inducing myocardial regeneration via paracrine activation, prevention of cardiac apoptosis, and other mechanisms. Several studies have convincingly shown that human embryonic stem cells can be differentiated into cardiomyocytes (hESC-CMs) and that these cells can be used to effectively improve cardiac function following myocardial infarction (MI). The objectives of this CIRM Disease Team Therapy proposal are two-fold: (1) to perform IND enabling studies involving hESC-CM for subsequent FDA approval and (2) to complete a Phase I trial with ESHF patients undergoing the left ventricular assist device (LVAD) procedure whereby hESC-CMs will be injected at the same time.
Statement of Benefit to California: 
Coronary artery disease (CAD) is the number one cause of mortality and morbidity in the US. Following myocardial infarction (MI), the limited ability of the surviving cardiac cells to proliferate thereafter renders the damaged heart susceptible to dangerous consequences such as heart failure. In recent years, stem cell therapy has emerged as a promising candidate for treating ischemic heart disease. In contrast to adult stem cells, human embryonic stem cells (hESCs) have the advantage of being pluripotent, which endows them with the ability to differentiate into virtually every cell type. Numerous studies have demonstrated that hESC-derived cardiomyocytes (hESC-CMs) can improve cardiac function in small and large animal models. In addition, the FDA has approved hESC-derived oligodendrocyte progenitor cells for patients with acute spinal cord injury and hESC-derived retinal pigment epithelial cells for patients with Stargardt’s macular dystrophy. Hence the conventional controversies and regulatory hurdles related to hESC-based trials are no longer major barriers to the field. In this proposal, we seek to extend and translate the robust pre-clinical data into clinical reality by demonstrating the safety and feasibility of hESC-CM transplantation. We will perform careful IND-enabling research in the first 3 years. Afterwards, our medical teams will initiate a phase 1 clinical trial involving 10 patients with end stage heart failure (ESHF). We will perform direct intramyocardial injection of hESC-CMs in ESHF patients undergoing left ventricular assist device (LVAD) implantation as a bridge toward orthotopic heart transplantation (OHT). After the patients have received matching donor hearts, the native recipient hearts will be explanted. This will provide us an opportunity to carefully assess the fate of these cells and to ensure safety before we can embark on a larger clinical trial in Years 5-10.
Progress Report: 
  • Patients with end-stage heart failure (ESHF) have a 2-year survival rate of 50% with conventional medical therapy. This dismal survival rate is actually significantly worse than patients with AIDS, liver cirrhosis, stroke, and other debilitating diseases. Stem cell therapy may be a promising strategy for inducing myocardial regeneration via paracrine activation, prevention of cardiac apoptosis, and other mechanisms. Several studies have convincingly shown that human embryonic stem cells can be differentiated into cardiomyocytes (hESC-CMs) and that these cells can be used to effectively improve cardiac function following myocardial infarction (MI). Over the past year, we have assembled a strong multi-disciplinary team and applied for the CIRM Disease Team Therapy proposal.

Preclinical Development and First-In-Human Testing of [REDACTED] in Advanced Heart Failure

Funding Type: 
Disease Team Therapy Planning I
Grant Number: 
DR2-05434
ICOC Funds Committed: 
$106 239
Disease Focus: 
Heart Disease
oldStatus: 
Closed
Public Abstract: 
This application seeks to bring to the clinic a new treatment for myocardial disease based on human embryonic stem cell (hESC) derived cardiomyocytes. hESC-cardiomyocytes have the unique potential to address the underlying cause of heart disease by repopulating areas of damaged myocardium (heart tissue) with viable cardiac cells. This therapeutic approach represents a potential breakthrough in heart disease treatment, serving one of the most intractable, largest, and most costly unmet clinical needs in the U.S. Currently available heart disease treatments have demonstrated ability to slow progression of the disease, but to date none can restore the key underlying defect in heart failure, a loss of contractile function. Cell therapy approaches have generated excitement for their unique potential to play a curative role in myocardial disease through the restoration of lost contractile and/or circulatory function. hESC-cardiomyocytes are unique amongst the cell therapy approaches in that they are a human cardiomyocyte (heart muscle cell) product; replacing damaged myocardium with viable heart cells which can integrate and form fully functional cardiac tissue. This approach has the potential to significantly halt or reverse cardiac functional decline. These benefits can significantly impact patient medication requirements and hospitalizations associated with ongoing cardiac decline, key drivers of the enormous health care costs associated with heart failure. The proposed scope of this project includes activities leading up to and including a regulatory filing with the FDA to initiate clinical testing of hESC-cardiomyocytes for the treatment of heart failure, as well as the enrollment and initial follow-up of a small cohort of patients in a first-in-human trial. The proposed product has completed extensive process development, product characterization, and preclinical (animal model studies) proof-of-concept studies to date. The scope of the proposed research includes: (i) performance of key preclinical safety and efficacy studies to enable entry to clinical testing (ii) manufacture of material for use in preclinical studies, development work, and clinical testing (iii) development and qualification of assays for product characterization, and (iv) preparation for and execution of initial clinical studies.
Statement of Benefit to California: 
The proposed project has the potential to benefit the state of California through 1) providing improved medical outcomes for patients with heart disease, 2) increasing California’s leadership in the emerging field of stem cell research, and 3) preserving and creating high quality, high paying jobs for Californians. Heart disease is one of the most intractable, wide-spread, and fatal diseases in the U.S. More than 5.8 million Americans currently suffer from heart failure; close to 60% of heart failure patients die within 5 years of diagnosis. Although specific statistics are not available for California, they are likely similar to those nationwide, with incidence of more than 10 in 1000 individuals >65 years of age (AHA, 2010). Currently available heart disease therapies have demonstrated the ability to slow disease progression, but to date none can restore the key underlying defect leading to heart failure, a loss of cardiac contractile function. Cell therapy, an approach to regenerate or repair the damaged heart with new cells, addresses this fundamental need, and is considered one of the most important and promising frontiers for the treatment of heart disease. Although multiple other cell therapy products are currently being evaluated for the treatment of heart disease, human embryonic stem cell derived cardiomyocytes have unique potential to address the underlying defect of loss of contractile activity in heart failure, by replacing scarred or damaged heart tissue with new, functional human heart cells to restore cardiac function. California has a history of leadership in biotechnology, and is emerging as a leader in the development of stem cell therapeutics. Cutting edge stem cell research, in many cases funded by CIRM, is already underway in academic research laboratories and biotechnology companies throughout the state. The proposed project has the potential to further increase California’s leadership in the field of stem cell therapeutics through the performance of the first clinical testing of an hESC-derived cardiac cell therapy. The applicant has been located in California since its inception, and currently employs nearly 200 full-time employees at its California headquarters with more than 50% of employees holding an advanced degree. These positions are highly skilled positions, offering competitive salaries and comprehensive benefits. The successful performance of the proposed project would enable significant additional jobs creation as the program progresses through more advanced clinical testing.

Phase I study of IM Injection of VEGF Producing MSC for the Treatment of Critical Limb Ischemia

Funding Type: 
Disease Team Therapy Planning I
Grant Number: 
DR2-05423
ICOC Funds Committed: 
$76 861
Disease Focus: 
Heart Disease
oldStatus: 
Closed
Public Abstract: 
Critical limb ischemia (CLI) represents a significant unmet medical need without any approved medical therapies for patients who fail surgical or angioplasty procedures to restore blood flow to the lower leg. CLI affects 2 million people in the U.S. and is associated with an increased risk of leg amputation and death. Amputation rates in patients not suitable for surgery or angioplasty are reported to be up to 30-50% after 1 year. Patients who are not eligible for revascularization procedures are managed with palliative care, but would be candidates for the proposed phase I clinical trial. In an effort to combat CLI, prior and ongoing clinical trials that our group and others have conducted have evaluated direct injection of purified growth factors into the limb that has low blood flow. Some trials have tested plasmids that would produce the blood vessel growth factors for a short period of time. These therapies did show benefit in early stage clinical trials but were not significantly better than controls in Phase III (late stage) trials, probably due to the short duration of presence of the growth factors and their inability to spread to the areas most needed. Other clinical trials ongoing in our vascular center and others are testing the patient’s own stem cells, moved from the bone marrow to the damaged limb, and those studies are showing some benefit, although the final assessments are not yet completed. Stem cells can have benefit in limb ischemia because they can actively seek out areas of low oxygen and will produce some growth factors to try to encourage blood vessel growth. But in cases where the circulation needs very high levels of rescue, this strategy might not be enough. As an improved strategy we are combining the stem cell and growth factor approaches to make a more potent therapy. We have engineered human Mesenchymal Stem Cells (MSCs) to produce high levels of the strong angiogenic agent VEGF for this novel approach (MSC/VEGF). We and others have documented over the past 20+ years that MSC are capable of sustained expression of growth factors, migrate into the areas of lowest oxygen in the tissues after injection, and wrap around the damaged or tiny blood vessels to secrete their factors where they are needed most. These MSC/VEGF cells are highly potent, safe and effective in our preclinical studies. These human stem cells designed to produce VEGF as “paramedic delivery vehicles armed with growth factor to administer” rapidly restored blood flow to the limbs of rodents who had zero circulation in one leg. With funding that could be potentially obtained through the proposed application we will follow the detailed steps to move this candidate therapy into clinical trials, and will initiate and complete an early phase clinical trial to test safety and potential efficacy of this product that is designed to save limbs from amputation.
Statement of Benefit to California: 
Critical Limb Ischemia (CLI) represents a significant unmet medical need without any curative therapies in its end stages, after even the best revascularization attempts using sophisticated catheters, stents, and bypass surgeries have failed. CLI affects over 2 million people in the US and the prevalence is increasing due to the aging of our population and the diabetes epidemic. In 2007, the treatment of diabetes and its complications in the USA generated $116 billion in direct costs; at least 33% of these costs were linked to the treatment of ischemic foot ulcers, associated with CLI. Once a patient develops CLI in a limb, the risk of needing amputation of the other limb is 50% after 6 years, with devastating consequences. Treatment costs are immense and lives are significantly shortened by this morbid disease. The symptoms associated with this very severe form of lower extremity peripheral artery disease (PAD) are pain in the foot at rest, non- healing ulcers, limb/digital gangrene and delayed wound healing. The quality of life for those with CLI is extremely poor and reported to be similar to that of patients with end stage malignancy. Most patients with CLI will undergo repeat hospitalizations and surgical/endovascular procedures in an effort to preserve the limb, progress to immobility and need constant care. Unfortunately, the limb salvage efforts are often not effective enough, and despite multiple attempts at revascularization, the wounds still fail to heal. The final stage in 25% of cases is limb amputation, which is associated with a high mortality rate within 6 months. Amputation rates in patients not suitable for revascularization are reported to be up to 30-50% after 1 year. Fewer than half of all CLI patients achieve full mobility after an amputation and only one in four above-the-knee amputees will ever wear a prosthesis. Between 199– 1999, over 28,000 first time lower extremity bypass procedures were performed in California for CLI, and 29% of patients were admitted to the hospital for at least one subsequent bypass operation or revision procedure. The 5-year amputation free survival rate for this group of CLI patients from California was only 51.1%. The direct costs to California for the treatment of CLI and diabetic ischemic ulcers are substantial. The lost ability of no-option CLI patients to remain in the CA workforce, to support their families, and to pay taxes causes additional financial strain on the state’s economy. The goal of the proposed study is to develop and apply a safe and effective stem cell therapy to save limbs from amputation due to disorders of the vasculature that currently cannot be cured. The successful implementation of our planned therapies will significantly reduce the cost of healthcare in California and could bring people currently unable to work due to immobility back to the workforce and active lifestyles, with a significantly improved quality of life.
Progress Report: 
  • A) Pre-clinical: The remainder of the IND-enabling studies for the development candidate MSC/VEGF were designed in consultation with Biologics Consulting Group (BCG). The project will begin with the IND-enabling phase and transition through regulatory approvals and through the Phase I clinical trial. The project has a Preclinical unit under the leadership of co-PI Dr. Jan Nolta, and a Clinical unit under the leadership of PI Dr. John Laird. The two units are well integrated, since the team has been meeting frequently since 2008 to plan the testing of the current and prior development candidates. The team is currently performing a Phase I stem cell therapy to test a medical device, as the result of those interactions. During the planning phase we met weekly, and worked continually on the MSC/VEGF project.
  • Co-PI Jan Nolta, Ph.D. is Scientific Director of the UC Davis/CIRM GMP Facility. Dr. Nolta’s team is expert in translational applications of gene-modified MSC at the level of GLP. The Pre-Clinical team is performing all IND-enabling studies for MSC/VEGF, and will manufacture and qualify the MSC and MSC/VEGF products in the GMP facility at UC Davis that is directed by Dr. Bauer (CMC lead). These studies are ongoing and we have been advised by BCG consulting lead Andra Miller, who was formerly Gene Therapy Group Leader at the FDA, CBER, Division of Cell and Gene Therapies. BCG is assisting with preIND preparation, through the planning grant period funding for this project.
  • B) Clinical: The Clinical team is led by PI John Laird MD, Medical Director of the UCD Vascular Center, who is an internationally recognized leader in the field of peripheral vascular interventions. He is the PI for multicenter and multinational trials to evaluate novel treatments for peripheral arterial disease. He has led clinical trials investigating the use of FGF-1, Hif, and VEGF to treat claudication and CLI. Christy Pifer is the experienced Project Manager who will guide the entire process. She is the Vascular Center’s clinical trials manager and orchestrates accrual of patients to all trials, including one ongoing Phase I stem cell clinical trial and another pending, as well as a Phase III gene transfer clinical trial. Ms. Pifer has coordinated over 100 Phase I, II and III clinical trials over the past 12 years. The planning grant allowed Ms. Pifer to contribute significant amounts of time to conducting meetings and designing the clinical study with Dr. Laird and other Vascular Center faculty. We had weekly meetings with the clinical and translational team members to finalize the CIRM Disease Team Grant Application.
  • C) Consultant meetings conducted through the Planning Grant Mechanism:
  • - Paragon was chosen as our CRO for the proposed trial. We had on-site meetings and conference calls with Paragon during the planning phase.
  • - Our consultant Dr. Andy Balber, was a Founder, and for ten years served as the CSO of Aldagen, Inc. At Aldagen since 2000, he helped the Company establish and maintain a clinical program during which patients were treated with stem cell products under seven cleared INDs. Dr. Balber has assisted our team with preparation of the preIND application, and will assist with further dialog with the FDA. We met frequently through conference call and email, and he edited our Disease Teams Grant proposal.
  • - Andra Miller, Director, Cell and Gene Therapy, Biologics Consulting Group, Inc, is a consultant for the development of regulatory strategies to facilitate rapid development of our cell and gene based therap. She and her team are providing support for CMC submission, pre-IND, RAC and IND preparation, Phase I product development strategies and assessment of cGLP compliance. Dr. Miller was Gene Therapy Group Leader for the Division of Cellular and Gene Therapies, Office of Therapeutics of FDA's Center for Biologics Evaluation and Research, for ten years. We met through conference call and email during the Planning Grant period and she edited our Disease Teams grant application.
  • Partner PI group: Dr. Herrera from the Reina Sofia Hospital, Cordoba University, Andalucia, is our partner, identified through the planning grant phase. Her team is currently performing clinical trials of MSC injections for CLI using intra-arterial administration. Now, using the strong development candidate MSC/VEGF, the two teams will each embark upon parallel clinical trials in their respective countries, each capitalizing on their own team’s stem cell delivery strengths to patients at the same stage of no option CLI. The two teams will use similar inclusion and exclusion criteria and will work closely together, if funded, to develop Phase I trials that are highly similar except for the route of injection. We had Skype and conference call meetings with interpreters, and frequent email contact during the Planning Grant phase. This partnership would not have been possible without the CIRM Planning Award.

Molecular Mechanisms Underlying Human Cardiac Cell Junction Maturation and Disease Using Human iPSC

Funding Type: 
Basic Biology III
Grant Number: 
RB3-05103
ICOC Funds Committed: 
$1 341 955
Disease Focus: 
Heart Disease
Pediatrics
Stem Cell Use: 
iPS Cell
Cell Line Generation: 
iPS Cell
oldStatus: 
Active
Public Abstract: 
Heart disease is the number one cause of death and disability in California and in the United States. Especially devastating is Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC), an inherited form of heart disease associated with a high frequency of arrhythmias and sudden cardiac death in young people, including young athletes, who despite their appearance of health are struck down by this type of heart disease. Even though it is inherited, early detection is hindered because people carrying the genetic code have highly variable clinical symptoms, making ARVC and catastrophic cardiac events very hard to predict and avoid. Evidence suggests that this heart disease is caused by mistakes in the genetic code essential for holding the mechanical integrity of heart muscle cells together or cell junctions. What is missing is an understanding of the basic biology of these heart muscle cell junctions in humans and appropriate human model systems to study their dynamics in heart disease, which is important since other heart diseases also share some of these same heart cell defects. Our goal is to understand the basic biology of how human heart muscle cell junctions mature and what happens in disease, by studying ARVC. Human iPS cells are a unique population of stem cells from our own tissues, such as skin, that have the same genetic information as the rest of our bodies. Thus, hiPS from people who carry the ARVC heart disease mistakes can be used in our laboratory to provide a true human model of that disease. We will generate heart muscle cells from hiPS from normal and ARVC donors that carry mistakes in the genetic code for cell junction components. We have identified new pathways that may be important causes of ARVC, thus we will also use our hiPS lines, to confirm whether these new pathways are truly important in human ARVC disease progression and if our approaches reverse disease progression. Characterization of our hiPS derived heart cells can also be exploited for translational medicine to predict an individual's heart cell response to drug treatment and provides a promising platform to identify new drugs for heart diseases, such as ARVC, which are currently lacking in the field. Recent advances in stem cell biology have highlighted the unique potential of hiPS to be used in the future as a source of cells for cell-based therapies for heart disease. However, prior to clinical application, a detailed understanding of the basic biology and maturation of these hiPS into heart muscle cells is required. Our studies seek to advance our understanding of how cell-cell junctions mature in hiPS and highlight tools that influence the microenvironment of the hiPS in a dish, to accelerate this process. This knowledge can also be exploited in regenerative medicine to achieve proper electromechanical integration of cardiac stem cells when using stem cells for heart repair, to improve longterm successful clinical outcomes of cardiac stem cell therapies.
Statement of Benefit to California: 
Heart disease is the number one cause of death and disability within the United States and the rates are calculated to be even higher for citizens of the State of California when compared to the rest of the nation. These diseases place tremendous financial burdens on the people and communities of California, which highlights an urgency to understand the underlying molecular basis of heart diseases as well as find more effective therapies to alleviate these growing burdens. Our goal is to improve heart health and quality of life of Californians by generating human stem cell models from people with an especially devastating form of genetic heart disease that affects young people and results in sudden cardiac death, to improve our molecular and medical understanding of how cardiac cells go wrong in the early stages of heart disease in humans. We will also test current drugs used to treat heart disease and new candidate pathways, that we have uncovered, to determine if and how they reverse and intervene with these defects. We believe that our model systems have tremendous potential in being used to diagnose, test an individual's heart cell's response to drug treatment, as well as predict severity of symptoms in heart diseases at an early stage, to monitor drug treatment strategies for the heart. We believe our studies also have a direct impact on regenerative medicine as a therapy for Californians suffering from heart disease, since data from our studies can identify ways to improve cardiac stem cell integration into the diseased heart when used for repair, as a way to improve long-term successful clinical outcomes of cardiac stem cell therapies. We also believe that our development of multiple human heart disease stem cells lines with unique genetic characteristics could be of tremendous value to biotechnology companies and academic researchers interested in large scale drug screening strategies to identify more effective compounds to rescue defects and treat Californians with heart disease, as well as provide important economic revenue and resources to California, which is stimulated by the development of businesses interested in developing these therapies further.
Progress Report: 
  • Heart disease is the number one cause of death and disability in California and in the United States. Especially devastating is Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC), an inherited form of heart disease associated with a high frequency of arrhythmias and sudden cardiac death in young people, including young athletes, who despite their appearance of health are struck down by this type of heart disease. Even though it is inherited, early detection is hindered because people carrying the genetic code have highly variable clinical symptoms, making ARVC and catastrophic cardiac events very hard to predict and avoid. Evidence suggests that this heart disease is caused by mistakes in the genetic code essential for holding the mechanical integrity of heart muscle cells together or cell junctions. What is missing is an understanding of the basic biology of these heart muscle cell junctions in humans and appropriate human model systems to study their dynamics in heart disease, which is important since other heart diseases also share some of these same heart cell defects. Our goal is to understand the basic biology of how human heart muscle cell junctions mature and what happens in disease, by studying ARVC. Human iPS cells are a unique population of stem cells from our own tissues, such as skin, that have the same genetic information as the rest of our bodies. Thus, hiPS from people who carry the ARVC heart disease mistakes can be used in our laboratory to provide a true human model of that disease. During the first year of our grant, we have enrolled sufficient numbers of normal and ARVC donors into our study. We have collected skin biopsy tissues from donors as means to generate hiPS cells. Our results show that hiPS cell lines can be efficiently generated from both normal and ARVC donors and we have extensively characterized their profiles, such that we know they are bona fide stem cell lines and can be used as a model system to dissect defects in cardiac cell junction biology between these various different hiPS lines. We have also developed efficient and robust methodologies to generate heart muscle cells from hiPS from normal and ARVC donors that carry mistakes in the genetic code for cell junction components and are now in the midst of characterizing their molecular, genetic, biochemical and functional profiles to identify features in these cells that are unique for ARVC. Through our previous studies, we identified new pathways that may be important causes of ARVC, thus we will also use our hiPS lines, to confirm whether these new pathways are truly important in human ARVC disease progression and if our approaches reverse disease progression. Towards this goal, we have generated novel tools to increase and decrease a component of this pathway in order to test these approaches and have preliminary data to show that these tools are efficient in altering levels of this component in heart muscle cells, which we are now applying towards understanding these pathways in hiPS derived heart muscle cells and reversing defects in heart muscle cells from ARVC hiPS derived lines. Based on our progress, we have met all of the milestones stated in our grant proposal and in some cases, surpassed some milestones. We believe progress over the next year, will allow us to define some of the key cellular defects in ARVC and advance our understanding of how cell-cell junctions mature in hiPS and highlight tools that influence the microenvironment of the hiPS in a dish, to accelerate this process.
  • Overall, we have been able to achieve the milestones proposed for Year 2 of the grant. We have generated a panel of control and ARVC hiPSC lines using integration-free based methods. We provide evidence of our method to generate robust numbers of hiPSC-derived cardiac cells that express desmosomal cell-cell junction proteins. We show ARVC lines that display disease symptom-specific features (adipogenic or arrhythmic), which phenocopy the striking and differential symptoms found in respective individual ARVC-patients as tools to study human ARVC. We also uncover desmosomal defects in hiPSC-derived cardiac muscle cells that underlie the disease features found in ARVC cells. We have also published two reviews in the field of cell-cell junctional remodeling and stem cell approaches that helps to further our understanding of this field in cardiomyocytes, that is relevant to human disease and our research using hiPS.

Characterization and Engineering of the Cardiac Stem Cell Niche

Funding Type: 
Basic Biology III
Grant Number: 
RB3-05086
ICOC Funds Committed: 
$1 181 306
Disease Focus: 
Heart Disease
Stem Cell Use: 
iPS Cell
oldStatus: 
Active
Public Abstract: 
Despite therapeutic advances, cardiovascular disease remains a leading cause of mortality and morbidity in both California and Europe. New insights into disease pathology, models to expedite in vitro testing and regenerative therapies would have an enormous societal and financial impact. Although very promising, practical application of pluripotent stem cells or their derivatives face a number of challenges and technological hurdles. For instance, recent reports have demonstrated that cardiac progenitor cells (CPCs), which are capable of differentiating into all three cardiovascular cell types, are present during normal fetal development and can be isolated from pluripotent stem cells. induced pluripotent stem cell (iPSC)-derived CPC therapy after a myocardial infarction would balance the need for an autologous, multipotent stem cell myocardial regeneration with the concerns of tumorigenicity using a more primitive stem cell. However, translating this discovery into a clinically useful therapy will require additional advances in our understanding of CPC biology and the factors that regulate their fate to develop optimized cell culture technology for CPC application in regenerative medicine. Cardiac cell therapy with hiPSC-derived cells, will require reproducible production of large numbers of well-characterized cells under defined conditions in vitro. This is particularly true for the rare and difficult to culture intermediates, such as CPCs. Our preliminary data demonstrated that a CPC niche exists during cardiac development and that CPC expansion is regulated by factors found within the niche microenvironment including specific soluble factors and ECM signals. However, our current understanding of the cardiac niche and how this unique microenvironment influences CPC fate is quite limited. We believe that if large scale production of hiPSC-derived CPCs is ever to be successful, new 3D cell culture technologies to replicate the endogenous cardiac niche will be required. The goals of this proposal are to address current deficiencies in our understanding of the cardiac niche and its effects on CPC expansion and differentiation as well as utilize novel bioengineering approaches to fabricate synthetic niche environments in vitro. The development of advanced fully automated in vitro culture systems that reproduce key features of natural niche microenvironments and control proliferation and/or differentiation, are critically needed both for studying the role of the niche in CPC biology but also the advancement of the field of regenerative medicine.
Statement of Benefit to California: 
Heart disease, stroke and other cardiovascular diseases are the #1 killer in California. Despite medical advances, heart disease remains a leading cause of disability and death. Recent estimates of its cost to the U.S. healthcare system amounts to almost $300 billion dollars. Although current therapies slow the progression of heart disease, there are few, if any options, to reverse or repair damage. Thus, regenerative therapies that restore normal heart function would have an enormous societal and financial impact not only on Californians, but the U.S. more generally. The research that is proposed in this application could lead to new therapies that would restore heart function after and heart attack and prevent the development of heart failure and death. We will develop the techniques to expand and transplant human cardiac progenitor cells. Combining tissue engineering with human pluripotent stem cells will facilitate the creation of new cardiovascular therapies.
Progress Report: 
  • Cardiovascular disease is the leading cause of morbidity and mortality in the United States. As humans lack the ability to regenerate myocardial tissue lost afte a heart attcak, there has been great focus on cardiovascualr regenerative therapies with the use of human embryonic stem cells (ESC) and induced pluripotent stem cells (iPSC). There has been increased attention towards developing tissue engineering as a method to standardize methods to differentiate human ESCs and iPSCs into cardiovascular progenitor cells (CPC) expand these progenitor cells in a standardized manor. We have focused on developing techniques to allow expansion of these CPCs into clinically relevany numbers by determining: 1. Conditions to optimize their derivation into clinically numbers using clinical grade techniques.
  • 2. Defininy and optimizing the extracellular matrxi to be used to maintain these CPCs in an undifferentiated state to allow their expansion to clinically required numbers. We studied the endogenous environment that these CPCs exist in fetal development and focused on the extracellular matrix proteins that help support these CPCs during development. By studying the array of proteins endogenously in developing heart we now will shift our focus on re-engineering this environment in-vitro to be able to mimic this growth to use this as a mean to grow and expand these progenitors for use clinically in the future. Currently we are deriving these CPCs from human ESC and iPSC and expanding them on different combinations of proteins as determined in the staining of the endogenous fetal environment. We hope to by the end of this porject determine the ideal conditions for derivation of these CPCs from iPSCs and the environmental cues needed for culturing these cells to allow for maximal yield for potential use in clinical regenerative therapies in the future.

Mechanisms of Direct Cardiac Reprogramming

Funding Type: 
Basic Biology III
Grant Number: 
RB3-05174
ICOC Funds Committed: 
$1 708 560
Disease Focus: 
Heart Disease
oldStatus: 
Active
Public Abstract: 
Heart disease is a leading cause of adult and childhood mortality. The underlying pathology is typically loss of heart muscle cells that leads to heart failure, or improper development of specialized cardiac muscle cells called cardiomyocytes during embryonic development that leads to congenital heart malformations. Because cardiomyocytes have little or no regenerative capacity after birth, current therapeutic approaches are limited for the over 5 million Americans who suffer from heart failure. Embryonic stem cells possess clear potential for regenerating heart tissue, but efficiency of cardiac differentiation, risk of tumor formation, and issues of cellular rejection must be overcome. Our recent findings regarding direct reprogramming of a type of structural cell of the heart or skin called fibroblasts into cardiomyocyte-like cells using just three genes offer a potential alternative approach to achieving cardiac regeneration. The human heart is composed of muscle cells, blood vessel cells, and fibroblasts, with the fibroblasts comprising over 50% of all cardiac cells. The large population of cardiac fibroblasts that exists within the heart is a potential source of new heart muscle cells for regenerative therapy if it were possible to directly reprogram the resident fibroblasts into muscle cells. We simulated a heart attack in mice by blocking the coronary artery, and have been able to reprogram existing mouse cardiac fibroblasts after this simulated heart attack by delivering three genes into the heart. We found a significant reduction in scar size and an improvement in cardiac function that persists after injury. The reprogramming process starts quickly but is progressive over several weeks; however, how this actually occurs is unknown. Because this finding represents a new approach that could have clinical benefit, we propose to reveal the mechanism by which fibroblast cells become reprogrammed into heart muscle cells, which will be critical to refine the process for therapeutic use. We will do this by analyzing the changes in how the genome is interpreted and expressed at a genome-wide level at different time points during the process of fibroblast to muscle conversion, which represents the fundamental process that leads to reprogramming. The findings from this proposal will reveal approaches to refine and improve human cardiac reprogramming and will aid in translation of this technology for human cardiac regenerative purposes.
Statement of Benefit to California: 
This research will benefit the state of California and its citizens by helping develop a new approach to cardiac regeneration that would have a lower risk of tumor formation and cellular rejection. In addition, the approach could remove some of the hurdles of cell-based therapy including delivery challenges and incorporation challenges. The mechanisms revealed by this research will enable refinement of the method that could potentially then be used to treat the hundreds of thousands of Californians with heart failure.
Progress Report: 
  • Heart disease is a leading cause of adult and childhood mortality. The underlying pathology is typically loss of heart muscle cells that leads to heart failure, or improper development of specialized cardiac muscle cells called cardiomyocytes during embryonic development that leads to congenital heart malformations. Because cardiomyocytes have little or no regenerative capacity after birth, current therapeutic approaches are limited for the over 5 million Americans who suffer from heart failure. Embryonic stem cells possess clear potential for regenerating heart tissue, but efficiency of cardiac differentiation, risk of tumor formation, and issues of cellular rejection must be overcome.
  • Our recent findings regarding direct reprogramming of a type of structural cell of the heart or skin called fibroblasts into cardiac muscle-like cells using just three genes offer a potential route to achieve cardiac regeneration after cardiac injury. The large population of cardiac fibroblasts that exists within the heart is a potential source of new heart muscle cells for regenerative therapy if it were possible to directly reprogram the resident fibroblasts into muscle cells. In the last year, we simulated a heart attack in mice by blocking the coronary artery, and have been able to reprogram existing mouse cardiac fibroblasts after this simulated heart attack by delivering three genes into the heart. We found a significant reduction in scar size and an improvement in cardiac function that persists after injury. The reprogramming process starts quickly but is progressive over several weeks; however, how this actually occurs is unknown. Because this finding represents a new approach that could have clinical benefit, we are investigating the mechanism by which fibroblast cells become reprogrammed into heart muscle cells, which will be critical to refine the process for therapeutic use. During the last year, we have analyzed the changes in how the genome is interpreted and expressed at a genome-wide level at different time points during the process of fibroblast to muscle conversion, which represents the fundamental process that leads to reprogramming. We have also generated many reagents that will allow us to identify how the reprogramming factors interact with DNA to alter the interpretation. These reagents will be used in the coming year to more thoroughly investigate the epigenetic changes that induce changes in interpretation of the DNA, leading to the cardiac muscle phenotype. The findings from this proposal will reveal approaches to refine and improve human cardiac reprogramming and will aid in translation of this technology for human cardiac regenerative purposes.
  • Heart disease is a leading cause of adult and childhood mortality. The underlying pathology is typically loss of heart muscle cells that leads to heart failure, or improper development of specialized cardiac muscle cells called cardiomyocytes during embryonic development that leads to congenital heart malformations. Because cardiomyocytes have little or no regenerative capacity after birth, current therapeutic approaches are limited for the over 5 million Americans who suffer from heart failure. Embryonic stem cells possess clear potential for regenerating heart tissue, but efficiency of cardiac differentiation, risk of tumor formation, and issues of cellular rejection must be overcome.
  • Our recent findings regarding direct reprogramming of a type of structural cell of the heart or skin called fibroblasts into cardiac muscle-like cells using just three genes offer a potential route to achieve cardiac regeneration after cardiac injury. The large population of cardiac fibroblasts that exists within the heart is a potential source of new heart muscle cells for regenerative therapy if it were possible to directly reprogram the resident fibroblasts into muscle cells. We have simulated a heart attack in mice by blocking the coronary artery, and have been able to reprogram existing mouse cardiac fibroblasts after this simulated heart attack by delivering three genes into the heart. We found a significant reduction in scar size and an improvement in cardiac function that persists after injury. The reprogramming process starts quickly but is progressive over several weeks; however, how this actually occurs is unknown. Because this finding represents a new approach that could have clinical benefit, we are investigating the mechanism by which fibroblast cells become reprogrammed into heart muscle cells, which will be critical to refine the process for therapeutic use. During the last year, we have analyzed the changes in how the genome is interpreted and expressed at a genome-wide level at different time points during the process of fibroblast to muscle conversion, which represents the fundamental process that leads to reprogramming. We have mapped the dynamic and sequential changes that are occurring on the DNA during reprogramming of cells. In the coming year, we will be integrating data from studies of epigenetic changes, DNA-binding of reprogramming factors, and the resulting alterations in activation or repression of genes that are responsible for changing a fibroblast into a cardiac muscle cell. The findings from this proposal will reveal approaches to refine and improve human cardiac reprogramming and will aid in translation of this technology for human cardiac regenerative purposes.

Antibody tools to deplete or isolate teratogenic, cardiac, and blood stem cells from hESCs

Funding Type: 
Tools and Technologies II
Grant Number: 
RT2-02060
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.

Optimization in the Identification, Selection and Induction of Maturation of Subtypes of Cardiomyocytes derived from Human Embryonic Stem Cells

Funding Type: 
Tools and Technologies I
Grant Number: 
RT1-01143
ICOC Funds Committed: 
$906 629
Disease Focus: 
Heart Disease
Stem Cell Use: 
Embryonic Stem Cell
Cell Line Generation: 
Embryonic Stem Cell
oldStatus: 
Closed
Public Abstract: 
Cardiovascular diseases remain the major cause of death in the western world. Stem and progenitor cell-derived cardiomyocytes (SPC-CMs) hold great promise for the myocardial repair. However, most of SPC-CMs displayed heterogeneous and immature electrophysiological phenotypes with substantial automaticity. Implanting these electrically immature and inhomogeneous CMs to the hearts would be arrhythmogenic and deleterious. Further optimization in identification, selection and inducing maturation of subtypes of CMs from primitive SPC-CMs are paramount for developing a safe and effective cell-based therapy. Commonly used CM isolation techniques are microdissection, density sedimentation or promoter-driven, fluorescence-activated cell sorting (FACS). Microdissection and density sedimentation are labor intensive and lack of purity. Promoter-driven FACS may compromise cell viability and which promoter is proficient for selection remains unclear. We have established several antibiotics (Abx)-resistant human embryonic stem cell (hESC) lines conferred by lentiviral vectors under the control of various cardiac-specific promoters. With simple Abx treatment, we have easily isolated >95% pure hESC-CMs at various stages of differentiation from embryoid bodies (EBs). Using this Abx selection system, we also found that electrical maturation and differentiation of primitive hESC-CMs depended heavily on developmental cues from extracardiac cells in the EBs. This Abx selection system therefore could be used easily to purify CMs for mechanistic studies and future cell-based therapies. However, the subtype specification of atrial, ventricular and pacemaking CMs appears to occur at very early stages of differentiation because early EBs possess all three types of cells. Furthermore, various cardio-specific promoters have been shown to select preferentially certain subtypes of CMs. In order to use these promoters and Abx resistance to sub-select particular types of CMs at early stages of differentiation, we need to know the timing and sequence of expressions of various cardiac promoters during the EB development. For this later purpose, we will generate hESC lines expressing different colors of fluorescent proteins under the control of various cardiac-specific promoters respectively to determine the timing of expressions of these promoters in the EBs. Based on the sequence of expression, we will generate the Abx-resistant hESC lines under the control of these promoters to sub-select CMs. We will then study the EP properties of these sub-selected hESC-CMs and their interactions with extra-cardiac cells. The overall goal of this proposal is to establish an In Vitro system to track the sequence of expressions of various promoters in order to sub-select particular phenotypes of CMs by the Abx-resistance method. As a result, we will be able to optimize the selection and induction of a population of mature and homogeneous hESC-CMs for a safe and effective cell-based therapy.
Statement of Benefit to California: 
Cardiovascular diseases remain the major cause of death in the western world. Stem and progenitor cell (SPC)-based cell therapies in animal and human studies suggest promising therapeutic potentials. However, most SPC-derived cardiomyocytes (SPC-CMs) displayed heterogeneous and immature electrophysiological (EP) phenotypes with substantial automaticity. Implanting these electrically immature and inhomogeneous CMs to the hearts would be arrhythmogenic and deleterious. Further optimization in identification, selection and inducing maturation of subtypes of CMs from these primitive SPC-CMs are badly needed. Most frequently used isolation techniques are microdissection, density sedimentation or promoter-driven, fluorescence-activated cell sorting (FACS). Microdissection and density sedimentation are labor intensive and lack of purity. Promoter-driven FACS may compromise cell viability and which promoter is proficient for the cardiomyocyte selection remains to be determined. None of the laboratories in the world has success in developing an easy and efficient way to isolate the SPC-CMs. As a result, no method has been developed to induce the maturation of SPC-CMs. We already have the technology to efficiently isolate pure populations of human embryonic stem cell-derived CMs (hESC-CMs) from the embryoid bodies. The proposed research will further determine which type of promoter is best to properly sub-select a specific phenotype of hESC-CMs for future cell-based therapies in California. Most importantly, using this antibiotics-based selection method, we have started investigating the methods for inducing maturation of these sub-selected and primitive CMs. With both goals achieved, we will make California the first state to have a safe and effective cell-based therapy for myocardial repair with a mature and homogeneous population of hESC-CMs. None of stem cell-related research in California is devoted to optimize the selection, identification and induction of maturation of a specific phenotype of hESC-CMs in order to develop a safe cell-based therapy. The proposed research will be the first to achieve this goal proposed by CIRM Tools and Technologies Award. The success of this proposal will also make California the epicenter of the next generation of cell therapies and will benefit its citizens who have significant cardiovascular diseases.
Progress Report: 
  • The goal of our project is to develop methods to induce stem cells to differentiate into heart cells. Importantly, there are three major types of heart cells, which correspond to the ventricle (the major chambers that pump blood to the body), the atria (the smaller chambers that pump blood to the ventricles), and the nodes (these are the regions within the heart where the "pacemaker" cells are found, which control the heart rate). If we can produce pure populations of ventricular, atrial, or nodal cells, we can potentially use these cells for "replacement therapy" for patients which have had heart attacks or who have developed arrhythmias. During the first year of the research, we succeeded in producing cells that correspond to the ventricle. Furthermore, we have developed novel culturing techiques that improve the differentiation of the cells into atrial and nodal type myocytes, and the new strategies look very promising for the future research of this project.
  • The goal of our project is to develop methods to induce stem cells to differentiate into heart cells. Importantly, there are three major types of heart cells, which correspond to the ventricle (the major chambers that pump blood to the body), the atria (the smaller chambers that pump blood to the ventricles), and the nodes (these are the regions within the heart where the "pacemaker" cells are found, which control the heart rate). If we can produce pure populations of ventricular, atrial, or nodal cells, we can potentially use these cells for "replacement therapy" for patients which have had heart attacks or who have developed arrhythmias. During the first year of the research, we succeeded in producing cells that correspond to the ventricle. Furthermore, we have developed novel culturing techiques that improve the differentiation of the cells into atrial and nodal type myocytes, and the new strategies look very promising for the future research of this project.

Induction of cardiogenesis in pluripotent cells via chromatin remodeling factors

Funding Type: 
New Faculty II
Grant Number: 
RN2-00903
ICOC Funds Committed: 
$2 847 600
Disease Focus: 
Heart Disease
Stem Cell Use: 
Embryonic Stem Cell
iPS Cell
oldStatus: 
Closed
Public Abstract: 
Heart disease is one of the biggest killers in the civilized world, and as populations age, this trend will increase dramatically. Currently the only way to treat failing hearts is with expensive and relatively ineffective drugs, or by heart transplantation. Ideally, we would like to be able to regenerate sick or dead heart tissue. The best strategy would be to make new heart cells that match the patients' cells (to avoid rejection), and inject them into diseased heart so that they could regenerate the sick heart.Unfortunately, current strategies that are planned to do so are ineffectual. We wish to attempt to generate heart cells from human embryonic stem cells, or skin-derived "induced pluripotent cells" by "reprogramming" the stem cells into heart cells. This would be accomplished by turning on heart genes that normally are off in stem cells and seeing if this turns stem cells into heart cells. If this approach is successful, these newly generated stem cells could be used for regenerative therapies in the future.
Statement of Benefit to California: 
Heart disease is the leading killer of adults in the Western world. Hundreds of thousands of people in the US die of heart failure of sudden cardiac death each year. Largely, this is because inadequate therapies exist for the repair or treatment of the diseased heart. Our goal is to develop a means to efficiently convert pluripotent stem cells, including induced pluripotent cells (iPS cells) into new heart cells that could be used therapeutically to help regenerate healthy heart tissue. The results of our studies will help develop new technology that is likely to contribute to the California biotechnology industry. Our studies will develop technologies that can be used by biotechnology companies and researchers who wish to develop regenerative medicine therapies in a clinical setting. We are working closely with California companies to develop new microscopes, assay devices, and analytical software that could be the basis for new product lines or new businesses. If therapies do come to fruition, we anticipate that California medical centers will be leading the way. The most important contribution of this study will be to improve the health of Californians. Heart disease is a major cause of mortality and morbidity, resulting in billions of dollars in health care costs and lost days at work. Our goal is to contribute research that would ultimately improve the quality of life and increase productivity for millions of people who suffer from heart disease.
Progress Report: 
  • We hypothesized that human embryonic stem cells (hESCs) or induced pluripotent stem cells (iPS cells, which are derived from skin or other adult cells) can be efficiently reprogrammed to become heart cells using a combination of factors that includes proteins that unwind DNA. To test this hypothesis, we proposed three specific aims. For each we have achieved significant progress. In progress toward our first aim, we have been able to enhance cardiac differentiation of mouse iPS cells by 20%, and have devised strategies to increase this success rate. Our second aim was directed at understanding how important the chromatin remodeling factor, Baf60c, was in the induction of heart cells from pluripotent cells. We have made significant progress in this regard, mostly in developing the complex genetic tools required to investigate this important question. The third aim was to understand how Baf60c and its collaborating factors work to enhance heart cell formation. Again, we have had considerable success in early experiments that indicate that we will be able to address these questions fully in the remaining years of the granting period. Overall, our first year of funding has allowed us to move rapidly forward in understanding how to propel a stem cell toward becoming a heart cell; these results will be important to understand how heart cells are made in the body, and how their genesis can be harnessed using the power of stem cells.
  • We have been studying ways to understand how heart cells form from stem cells, and how we could help make the process more efficient, to generate new heart cells for patients with damaged hearts due to heart attacks. We have focused on the finding that cellular machines that unwind DNA from chromosomes, so-called chromatin remodeling factors, are important for turning on heart genes. To date we have been generating the important biological tools required for these studies. These include stem cells in which some of these chromatin genes have been inactivated, as well as DNA constructions that will be inserted into embryonic stem cells to attempt to induce them to become heart cells. In parallel we have been working towards using these factors to transform other types of cells, such as skin cells, into cardiomyocytes; in collaboration with our colleagues we have made significant progress towards this goal, and are now investigating the importance of the chromatin remodeling complexes in this process. Our progress has been excellent, and we are confident that we are making great strides towards regenerative medicine in the context of heart disease.
  • We have been studying ways to understand how heart cells form from stem cells, and how we could help make the process more efficient, to generate new heart cells for patients with damaged hearts due to heart attacks. We have focused on the finding that cellular machines that unwind DNA from chromosomes, so-called chromatin remodeling factors, are important for turning on heart genes. To date we have been generating the important biological tools required for these studies. These include stem cells in which some of these chromatin genes have been inactivated, as well as DNA constructions that will be inserted into embryonic stem cells to attempt to induce them to become heart cells. In parallel we have been working towards using these factors to transform other types of cells, such as skin cells, into cardiomyocytes; in collaboration with our colleagues we have made significant progress towards this goal, and are now investigating the importance of the chromatin remodeling complexes in this process. Our progress has been excellent, and we are confident that we are making great strides towards regenerative medicine in the context of heart disease.
  • In the last year, we have made significant progress on this project, which aims to understand how heart cells can be produced from pluripotent cells. We have been able to understand the gene program that is controlled by a so-called chromatin remodeling protein, a protein that unwinds DNA to allow genes to be turned on. This protein, called Baf60c, turns on many of the genes that give a heart cell its basic functions, like beating. We have also created stem cell -based tools that will allow us in the final year of this project to identify the partner proteins that allow Baf60c to function, and where in our genome Baf60c turns genes on.
  • During the tenure of this award, we have made some exciting discoveries about how genes are regulated during the process of heart cell formation from embryonic stem cells. In particular, we focused our efforts on a group of proteins that regulate other genes using a process called chromatin remodeling. We discovered that one such chromatin remodeling protein is required for genes that are specific to the heart to be turned on in heart cells. We also discovered new proteins that are also important for the formation of the heart. In studying these chromatin remodeling proteins in an embryonic stem cell system, we identified how these proteins turn on the "right" set of genes in the earliest stages of commitment of stem cells to heart cell progenitors. Finally, we identified the nature of the group of proteins that work together as part of chromatin remodeling "complexes", which for the first time tells us how these proteins assemble together to regulate heart genes. These results have paved the way for studies aimed at creating new heart cells, and have opened up some exciting new possibilities to improve this process.

Derivation and analysis of pluripotent stem cell lines with inherited TGF-b mediated disorders from donated IVF embryos and reprogrammed adult skin fibroblasts

Funding Type: 
New Cell Lines
Grant Number: 
RL1-00662
ICOC Funds Committed: 
$1 424 412
Disease Focus: 
Heart Disease
Stem Cell Use: 
Embryonic Stem Cell
iPS Cell
Cell Line Generation: 
Embryonic Stem Cell
iPS Cell
oldStatus: 
Closed
Public Abstract: 
The field of regenerative medicine revolves around the capacity of a subset of cells, called stem cells, to become the mature tissues of the adult human body. By studying stem cells, we hope to develop methods and reagents for treating disease. For instance, we hope to develop methods for making stem cells become cardiovascular cells in the lab which could then be used to rapidly screen large numbers drugs that may be used to treat cardiovascular disease. In another example, if we are able to create bone in the lab from stem cells, we may be able to help treat people with catastrophic skeletal injuries such as wounded soldiers. Until recently, the most flexible type of stem cell known was the embryonic stem cell. Embryonic stem cells are pluripotent, meaning they can give rise to all of the adult tissues. In contrast, stem cells found in the adult are considered only multipotent, in that they can only become a limited number of mature cells. For example, bone marrow stem cells can give rise to all of the components of the blood, but cannot make nerves for a spinal chord. Breakthroughs in the past couple of months have indicated that it is possible to "reprogram" adult skin cells and make them become pluripotent, like stem cells from an embryo. These new kind of cells ares called "induced pluripotent cells" or iPS cells for short. This has lead to great excitement within the scientific community because it raises the possibility that we may use this technology to rapidly create pluripotent stem cells from a large host of human diseases using skin from affected individuals. However, whether the new iPS cells made from skin cells and embryonic stem cells are functionally the same in all applications remains to be seen. Our lab is in the unique position to test this hypothesis. We have derived several normal embryonic stem cell lines and are in the process of deriving iPS cells from normal skin. Furthermore, we are fortunate enough to have begun deriving a new embryonic stem cell line harboring an inherited mutation that results in severe cardiovascular and bone disease that affects more than 7,500 Californians. What's more, one of our collaborators has over the past ten years assembled a cell bank of more that 50 unique adult skin cell lines with the same inherited disease. Therefore, for our proposal, we will make new normal and disease specific iPS and embryonic stem cell lines. We will use these new stem cell lines to test whether the iPS and embryonic stem cells are truly functionally the same, by comparing them after we make them become cardiovascular and bone cells. This work will allow us to advance the field of regenerative medicine on two fronts. 1. We will perform an important comparison of iPS and embryonic stem cell lines. 2. We will compare the disease specific cells with normal cells which will help us better understand cardiovascular and bone disease and pave the way for the development of new therapies.
Statement of Benefit to California: 
Our proposal compares normal and disease specific pluripotent stem cells derived from embryonic and adult skin sources. This proposal will benefit the state of California and its citizens in several specific ways. First, the specific inherited disease we are studying affects approximately one in every 5,000 people worldwide. That translates into over 7,500 Californians and over 60,000 men, women and children of every race and ethnic group in the United States. By examining the characteristics of the disease specific lines, we hope to better understand the mechanisms of the disease and create assays for screening new drugs that can be used to treat people with the disease. Second, this disease is one of a broad class of cardiovascular disease, called thoracic aortic disease. An estimated 3,700 Californians are treated for thoracic aortic disease every year. Our findings may provide insight into the mechanisms underlying these diseases and other cardiovascular diseases. Third, this disease also results in skeletal defects. By studying the mechanisms of the skeletal defects, we will better understand the mechanisms of bone development, which will lead to improved applications of stem cell therapies for individuals with bone injury and disease. Finally, by providing detailed comparisons of iPS and embryonic stem cells, our work will have important ramifications for the future direction of the entire field of stem cell research and regenerative medicine.
Progress Report: 
  • During the past year, we have used the funds from this grant to derive a new embryonic stem cell line with an inherited mutation that results in a severe cardiovascular and bone disease called Marfan syndrome that affects more than 7,500 Californians. In addition, using adult skin cell lines with the same inherited disease, we have made significant progress deriving iPS cells with Marfan syndrome. During the next year we also hope to expand our studies by recruiting patients with a disease very similar to Marfan syndrome called Loeys-Dietz syndrome, to donate skin biopsies so that we can make iPS cells to study that disease as well. Using these new stem cell lines, we are testing whether the iPS and embryonic stem cells are truly functionally the same, by comparing them after we make them become cardiovascular and bone cells.
  • One of the biggest challenges in stem cell biology is figuring out how to make the stem cells become the adult cells we want to study and not some other random adult cells. Over the past year, we have made great strides in turning our stem cells into the cell types most severely affected in people with Marfan syndrome, namely bone and cardiovascular cells. What is most exciting to us is that even with these preliminary studies, it looks like we might be seeing differences between the stem cells with Marfan syndrome and normal stem cells after they are coaxed into become the bone and cardiovascular cells. These results are still very preliminary though, and we need to take great care during the next year to rigorously repeat our experiments before we can be certain of those results. If we can reproduce the differences, these differences may be the basis for screening for new drugs to treat people with Marfan syndrome or lead to a better understanding as to what exactly is the sequence of cellular events that leads to the patient’s symptoms. What’s more, by studying how to efficiently make bone and cardiovascular cells from human embryonic stem cells and iPS cells in the dish, we hope to provide important data that could be beneficial in a wide variety of applications such as tissue engineering or cellular replacement therapies using bone or blood vessels.
  • Marfan Syndrome (MFS) is a genetic disorder that affects more than 7,500 Californians. Patients develop severe complications, affecting several parts of the body (eyes, limbs, aorta). During the last two years, we have used the funds from this grant to develop new cell lines aimed at studying MFS in a dish. These cell lines, are called pluripotent stem cells, and have been generated from: (i) an embryo that was donated for research and was known to have inherited the MFS disease (these cell lines are named human embryonic stem cells (hESCs)); and (ii) from skin biopsies of adult patients (these cell lines are named induced pluripotent stem cells (iPSCs)). These stem cell lines allow us to study MFS by differentiating the cells to adult cells (mainly bone and cardiovascular cells) and not other random adult cells. Using these new stem cell lines, we can test whether hESCs and iPSCs are functionally the same, by comparing them after we make them become cardiovascular and bone cells. We have observed that when the cells form bone or muscle cells, the stem cells with MFS are different and do not behave the same as those made with normal stem cells. We also started to use reagents that can force MFS cells to resemble and behave like normal bone cells. This is called “rescuing the disease phenotype”. For the first time, we are close to describing a stem cell-based technology not only to understand the mechanism(s) of the MFS but also to develop a screen for new drugs to treat people with MFS. However, we still need to confirm our results by repeating the experiments. Our results are very promising for understanding the bone issues in MFS, but continued efforts are also required to understand the cardiovascular issue. It is important to point out that the most important health risk associated with the disease is an aortic aneurysm that, if untreated, leads to death around 35 years old. In conclusion, we are continuing to generate data that will provide the foundation for improving our knowledge of the disease, and also will potentially assist us in developing new therapies for improving MFS patient lives.
  • The field of regenerative medicine revolves around the capacity of a subset of cells, called stem cells, to become the mature tissues of the adult human body. By studying stem cells, we hope to develop methods for treating a wide variety of diseases. For instance, we hope to develop methods for making stem cells become cardiovascular cells in the lab, which could then be used to rapidly screen large numbers of drugs that may be used to treat cardiovascular disease. We are also trying to create skeletal tissue from stem cells so that we may be able to help treat people with catastrophic skeletal injuries such as wounded soldiers.
  • Until recently, the most flexible type of stem cell known was the embryonic stem cell. Embryonic stem cells are pluripotent, meaning they can give rise to all cell types in the body. In contrast, stem cells found in the adult are considered only multipotent, in that they can only become a limited number of mature cells. Breakthroughs in the past five years have indicated that it is possible to "reprogram" adult skin cells and make them become pluripotent, like stem cells from an embryo. These new kinds of cells are called "induced pluripotent cells" or iPS cells. This has lead to great excitement within the scientific community because it raises the possibility that we may use this technology to rapidly create pluripotent stem cells from a large host of human diseases using easy to obtain tissue like skin and fat from affected individuals.
  • Our laboratory is in the unique position to test this hypothesis. We have derived several normal embryonic stem cell lines and iPS cells from normal skin. Furthermore, we have derived a new embryonic stem cell line and induced pluripotent stem cells from fibroblasts harboring an inherited mutation that results in severe cardiovascular and bone disease that affects more than 7,500 Californians, called Marfan's Syndrome.
  • We have created stem cells lines, both embryonic and induced pluripotent stem cells from cells having this disease. We have compared these cells to normal embryonic and induced pluripotent stem cells to examine exactly what makes these diseased cells behave in a way to have impaired bone formation. In addition, we have completed the differentiation, banking and full characterization of vascular cells derived from Marfan's Syndrome embryonic stem cells and Marfan’s syndrome induced pluripotent stem cells. We have seen that the cells with Marfan’s syndrome have a particular signaling pathway that has functional disregulation compared to normal, healthy cells. We have been able to explore how this disease process manipulates this pathway to cause this specific disease. Through this kind of modeling, we can use these cells to screen for treatment as well as model the disease in a way to manipulate the specific pathways this disease impacts to hopefully bring clinical treatments to patients who suffer from this disease.

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