Myriam Hemberger
The placenta is the organ that mediates and regulates nutrition of the growing fetus during pregnancy. Reflecting its importance for reproductive success, the cell lineage that gives rise to the placenta is set aside in the earliest differentiation event after fertilisation. Formation of the placenta is tightly controlled by a variety of genes with major players including key transcription factors, epigenetic regulators, imprinted genes and proteases. Because placental function is essential for fetal growth and survival and is also implicated in the aetiology of diseases in later life, knowledge in this field is crucial to advance our understanding of the molecular mechanisms that underlie fetal and adult health.
The focus of our research is how stem cell self-renewal and differentiation of the various placental cell types is controlled within the trophoblast lineage. At early stages, a tight epigenetic barrier - established by DNA methylation of a critical transcription factor - sets cells with a trophoblast cell fate apart from those that will form the embryo proper. A trophoblast stem (TS) cell niche is established that is controlled by a transcription factor network akin to the situation in ES cells. Exit from this stem cell compartment leads to the onset of differentiation into specific trophoblast cell types. One of these, termed trophoblast giant cell, can invade into the uterus and interact with maternal arteries where these cells induce an amazing physiological remodeling process of the maternal vasculature. We are investigating genes that regulate trophoblast differentiation and invasion into the uterus, and how they affect supply of maternal blood to the placenta. Complementing this genetic control, we are also studying the epigenetic mechanisms that help maintain trophoblast specific gene expression patterns.
Another aspect of our research is the interaction between fetal trophoblast cells and maternal immune cells at the feto-maternal interface of the placenta, and how this interaction may influence reproductive success. It is the combined regulation of all these processes that ensures normal embryonic development as well as maternal health during pregnancy.
