Pregnancy-specific beta-1-glycoprotein 1-enriched exosomes are involved in the regulation of vascular endothelial cell function during pregnancy

Pregnancy is a dynamic time period associated with significant physiological changes in the cardiovascular system. It is well known that during pregnancy, the placenta secretes a variety of molecular signals, including exosomes, into the maternal circulation to adapt to increased blood volume and maintain blood pressure at normotensive levels.In the present study, we compared the effects of exosomes derived from the peripheral blood serum of nonpregnant women (NP-Exo) and pregnant women with uncomplicated pregnancy (P-Exo) on endothelial cell function. We also analyzed the proteomic profiles of these two groups of exosomes and the molecular mechanisms underlying the effect of exosome cargoes on vascular endothelial cell function.We found that P-Exo were positively involved in regulating the function of human umbilical vein endothelial cell (HUVEC) and promoting the release of nitric oxide (NO). Furthermore, we revealed that trophoblast-derived pregnancy-specific beta-1-glycoprotein 1 (PSG1)-enriched exosomes treatment induced the promotion of HUVEC proliferation and migration as well as the release of NO. In addition, we found that P-Exo maintained blood pressure at normal levels in mice.These results suggested that PSG1-enriched exosomes derived from maternal peripheral blood regulate the function of vascular endothelial cells and play an important role in maintaining maternal blood pressure during pregnancy.