Unlike the majority of cells in the human body, stem cells can give rise to a wide variety of different cell types. This unique property – pluripotency – is the foundation of virtually all proposed uses of stem cells in regenerative medicine. Understanding the mechanisms that regulate stem cell pluripotency will facilitate the development of new approaches for isolating and culturing human stem cells in the laboratory and manipulating their development in the human body. Accordingly, the molecular mechanisms underlying the control of stem cell pluripotency and differentiation are currently a topic of intense interest.
Members of the Polycomb group of regulatory proteins play important roles in the maintenance of stem cell pluripotency by repressing genes involved in cellular differentiation. A major question in the field of stem cell biology concerns how Polycomb repression is “switched off” to permit the differentiation of stem cells into specialized cell types. Although the molecular nature of this switch is unknown, genetic studies in simple model organisms have suggested that the human CHD7 protein plays a critical role in this process by counteracting Polycomb repression. The goal of our research is to test this hypothesis and determine the role of CHD7 in the control of stem cell pluripotency and differentiation.
The proposed research may lead to novel approaches for the development of diagnostics, tools and therapies. If our hypothesis about the role of CHD7 in human stem cell development is correct, drugs that interfere with CHD7 function could be used to maintain or regulate stem cell pluripotency, either in culture or in patients. Such drugs might also prove extremely useful for creating new stem cell lines for use in regenerative medicine. An added benefit of our research is that it may suggest new treatments for CHARGE syndrome, a serious development that affects one in eight thousand births.
Pluripotency – the ability to differentiate into a seemingly unlimited variety of cell types – is a distinguishing feature of stem cells and the foundation of their potential uses in regenerative medicine. Recent studies have suggested that the human CHD7 protein may function as a genetic switch that triggers the differentiation of stem cells into specialized cell types. The information gained from the proposed research on CHD7 may facilitate the creation of new stem cell lines as well as new approaches for regulating stem cell pluripotency and differentiation in both the laboratory and the human body. In addition, the proposed research may permit the development of more effective treatments for CHARGE syndrome, a serious developmental disorder resulting from mutations in CHD7 that affects one in 8,000 births.