Effects of shear stress on uterine vasculature remodeling by trophoblasts
Dr. Jo James,
University of Auckland
Dr. James undertook her PhD at the University of Auckland, New Zealand, looking at the differentiation of specialized cells in the placenta termed trophoblasts and the effects of hypoxia on this process. She then moved to the UK where she has spent the past three years undertaking a New Zealand Foundation of Research Science and Technology fellowship at St George's University of London investigating the effects of low shear stress on the remodeling of the uterine vasculature by trophoblasts. This is a highly specialized process which involves the trophoblast migrating down the arteries, integrating into the endothelial cell layer and replacing these cells by inducing endothelial and smooth muscle cell apoptosis. This results in the uterine arteries increasing in diameter and losing their ability to regulate muscle tone such that they become independent of maternal vasoconstriction. This process is essential in order to deliver an adequate supply of blood to the growing baby, and when it is insufficient results in disorders of pregnancy including pre-eclampsia and babies that are born small. Both these complications can have life threatening consequences for both mother and baby. Low shear stress is believed to be important for uterine artery remodeling as the arteries are plugged by the trophoblasts for the first 10 weeks of the pregnancy, resulting in a slow high-resistance blood flow in these vessels. Dr. James' work using the BioFlux in combination with timelapse microscopy has shown that low shear stress during this time is important to allow trophoblast to migrate down the arteries, and aids trophoblast-induced endothelial apoptosis. Dr James has recently returned to the University of Auckland to begin a new fellowship investigating the presence of trophoblast stem cells in first trimester placenta, and hopes to tie these two interests together eventually by examining the effects of shear stress on trophoblast stem cell differentiation in the future.