Public Abstract California researchers will investigate how human embryonic stem cells can be transformed into working heart cells. This will, advance us toward a cure for chronic heart disease – for which there is now no cure other than heart transplantation. In so doing, they will broaden our understanding of how human embryonic stem cells, in general, can be transformed into functional cells that repair and regenerate parts of the body that are damaged by disease or injury. Each year there are 1.2 million heart attacks in the US. Although most do not result in immediate death, the cumulative damage leads to 500,000 deaths per year. When the oxygen supply to parts of the heart is shut off, heart muscle cells die leaving only scar tissue. Repeated small heart attacks build up this damage until the heart can no longer pump in response to exertion or excitement. At that stage, patients can die of congestive heart failure. It was previously thought that the scarring damage that leads to heart attacks was permanent. In recent years, however, researchers have shown how the scar tissue may be repaired with stem cells from bone marrow. However it is not known if the bone marrow stem cells become new heart cells or stimulate existing cells in the heart to perform better. This project’s researchers have one of the few laboratories world wide that are able to grow cardiac cells in large numbers and test them. This research project will build from the investigators’ ongoing stem cell research experience and study human embryonic stem cells because of the remarkable ability of such stem cells to turn into almost any type of adult cell. To convert the human embryonic stem cells into cardiac specific cells before they are delivered into the heart it is essential that we understand the molecular and biochemical process for differentiating human embryonic stem cells Researchers plan to study human embryonic stem cells with a chemical inducers to drive the transformation from stem cell to heart cells. The investigators will use a new technique which they have developed to label heart specified cells. They will study the molecular changes that underly the changes as the stem cell transforms. To understand this process fully, they will intensely analyze with computers, changes in newly discovered molecules that control the DNA code of life The resulting heart cells will be administer into the hearts to test if they are, in fact, turning into effective new cells that replace scar tissue in the heart ventricle as theorized. The fate of the transformed stem cells will be followed with a new magnetic imaging method to measure simultaneously the change in scar size, heart performance and the longevity of the stem cells.
Statement of Benefit to California:
Benefits to Californians The citizens of California have a right to expect many benefits from their forward looking approval of stem cell research. The initiative to fund human embryonic stem cell research will bring breakthroughs in treatments for previously untreatable diseases and create unprecedented new business opportunities. This proposal is directed to saving the thousands of Californians who die or suffer from heart failure each year. The only known cure available now is a heart transplant, but because the demand for hearts is greater than the number of donors, an alternative source of heart cells is needed. We are engaged in using the potentiality of human embryonic stem cells to turn them into heart cells that could be injected into damaged hearts and make them heal. To do this we have to build our understanding of the fundamental process of making a stem cell into a heart cell and then testing how effectively such cells can repair injured hearts. Knowing the underlying scientific principles at work in such a process will create the potential to benefit not only heart disease patients, benefits to Californians The citizens of California have a right to expect many benefits from their forward looking approval of stem cell research. The initiative to fund human embryonic stem cell research will bring breakthroughs in treatments for previously untreatable diseases and create unprecedented new business opportunities. This proposal is directed to saving the thousands of Californians who die or suffer from heart failure each year. The only known cure available now is a heart transplant, but because the demand for hearts is greater than the number of donors, an alternative source of heart cells is needed. We are engaged in using the potentiality of human embryonic stem cells to turn them into heart cells that could be injected into damaged hearts and make them heal. To do this we have to build our understanding of the fundamental process of making a stem cell into a heart cell and then testing how effectively such cells can repair injured hearts. Knowing the underlying scientific principles at work in such a process will create the potential to benefit not only heart disease patients, but also others suffering from diseases for which treatment is inadequate or not available. We anticipate that the entrepreneurial business spirit for which California is famous, will generate new jobs and businesses that will build upon the discoveries made in this type of stem cell research. This will leverage the economy because to have an inexhaustible supply of heart cells (or any other type of organ cell) will require significant commercial manufacturing processes. Biologicals for growing cells will be an industry. Newly discovered drugs can be tested on such cells by pharmaceutical companies. California will become the world’s provider of human cells, for transplantation treatments and cures, and it will reap the rewards of its investment.
SYNOPSIS: This proposal aims to understand the process of differentiation of human embryonic stem cells (hESCs) into heart cells using 5-aza-cytidine as an inducer and the use of a viral vector delivery of a heart promoter (myosin light chain -2v) and a reporter gene. The reporter gene will allow cells that have begun to be heart-like to be identified and subsequently cloned. A specific goal of this study is to advance the use of hESCs to provide a ready source of human heart cells for heart transplantation. The PI hypothesizes that 5-azacytidine demethylates the GATA-4 promoter which leads to activation of cardiomyocyte-specific genes through a cardiac transcription factor network. To test this hypothesis, it is proposed: (a) to examine whether the GATA-4 promoter is activated by inhibitors of DNA methyltransferase and/or histone deacetylase (HDAC); (b) to determine the state of cytosine phosphate guanine( CpG) methylation and occupancy state of GATA-4 cis-acting region by histone3-lysine9 ( H3-K9) acetylated and methylated forms, respectively, with chromatin immunoprecipitation as a function of cell differentiation. In addition,(c) mRNA sequences (both translated and untranslated regions) of known GATA-4 targets and their secondary target genes will be examined for potential microRNA target regions; (d) examining Notch and Notch-interacting signal network genes for mir1 and mir133 target sequences; (e) constructing a larger network representing hESC-to-cardiomyocyte differentiation pathway integrating the core cardiac transcription factors with their targets and putative miRNAs. The PI will determine whether treating hESCs with DMT and HDAC inhibitors can activate cardiac-specific marker genes. Knowing the role of critical molecules in the signaling pathways can be used to design growth media and the molecular instructions for differentiating hESCs into heart cells without a chemical inducer. Finally, to ensure that the differentiated heart cells are functional the PI will transplant hESC-derived cardiac cells into infarcted hearts of nude rats. Heart cells labeled with small iron particles will allow us to directly follow their location and longevity as well as measure infarct size and heart performance with MRI. INNOVATION & SIGNIFICANCE: The proposal addresses an important question related to how to maximally drive the formation of differentiated cardiac muscle from hESCs. The strategy incorporates some interesting ideas of the potential importance of epigenetic and microRNA control in the ESC- cardiogenesis pathways. STRENGTHS: The proposal incorporates interesting, timely concepts of epigenetic control in ES cell cardiogenesis. Furthermore, the long-term goal of this project is certainly worthy. WEAKNESSES: Using 5-azacytidine as a tool to promote cardiogenesis generates a relatively artificial system to study the normal pathways leading to cardiac muscle formation. The scientific environment could be stronger for these types of studies and the PI should be encouraged to find a strong set of collaborators. DISCUSSION: Some very modern thinking is expressed in the proposal, especially with the candidates that the PI proposes to test. However, while this proposal addresses an interesting question, the use of azocytidine to promote cardiogenesis is a "non-starter" since ES cell system is aberrant for cardiogenesis (given that cardiac muscle cell formation is the default pathway for ES cells). The proposal is based largely on in vitro approaches, and there are no plans described that will match results obtained from in vitro differentiation to relevance in vivo. Concerns were expressed by the reviewers regarding the environment, the availability of suitable expertise, and the potential to generate interpretable data.