Research may help scientists understand what causes pregnancy complications

Dr. Hanna Mikkola and researchers at UCLA’s Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research have identified a specific type of cell and a related cell communication pathway that are key to the successful growth of a healthy placenta. The findings could greatly bolster our knowledge about the potential causes of complications during pregnancy.
Specifically, the findings could help scientists clarify the particular order in which progenitor cells grow in the placenta, which would allow researchers to track foetal development and identify complications. Progenitor cells are cells that develop into other cells and that initiate growth of the placenta.
The placenta is the organ that forms inside the uterus during pregnancy and enables oxygen and nutrients to reach the foetus, but little is understood about the biological mechanisms and cellular processes responsible for this interface. Studying mouse models, Mikkola and her colleagues tracked individual cells in the placenta to determine which cells and which cell communication routes, or signalling pathways, were responsible for the healthy development of the placenta.
The UCLA team was the first to identify the cells that form the placenta: Epcamhi labyrinth trophoblast progenitors, or LaTP cells, can become the various cells necessary to form a specific tissue, in this case the placenta.
Mikkola and her colleagues also found a signalling pathway that consists of hepatocyte growth factor and its receptor, c-Met. The researchers found that this signalling pathway was required for the placenta to keep making LaTP cells. Production of LaTP cells, in turn, continues the production of the different cells needed to maintain the growth and health of the placenta while the foetus is growing. Placental health enables healthy transmission of oxygen and nutrients through the exchange of blood between the foetus and the mother. In the mice, when c-Met signalling stopped, foetal growth slowed, the liver did not develop fully and it produced fewer blood cells, and the foetus died.
‘Identifying this novel c-Met–dependent multipotent labyrinth trophoblast progenitor is a landmark that may help us understand pregnancy complications that are caused by defective placental exchange, such as foetal growth restriction,’ Mikkola said. University of California – Los Angeles