Chorionic villus-derived mesenchymal stem cell-mediated autophagy promotes proliferation and invasiveness of trophoblasts under hypoxia by activating the JAK2/STAT3 signalling pathway

Abstract Objectives Trophoblast dysfunction during pregnancy is fundamentally involved in preeclampsia. The aim of this study was to understand how human chorionic villous mesenchymal stem cells (CV-MSCs) operate in regulation of trophoblast function. Materials and Methods We treated trophoblasts with CV-MSC supernatant under hypoxic conditions, and transcriptome and pathway analyses of trophoblasts were performed. Western blotting and PCR analysis were used to examine the JAK2, STAT3 and autophagy associated protein expression levels in trophoblasts. Results The CV-MSC supernatant treatment markedly enhanced proliferation, invasion and autophagy. The RNA-seq revealed JAK2/STAT3 signalling as an upstream regulator, and STAT3 mRNA and protein levels increased during CV-MSC treatment. Inhibition of JAK2/STAT3 signalling reduced autophagy, survival and invasion of trophoblasts even in the presence of CV-MSCs, and blocking autophagy did not affect STAT3 activation in trophoblasts treated with CV-MSCs. Importantly, overexpression of STAT3 increased the levels of autophagy in trophoblasts; thus, it regulated positively autophagy in hypoxic trophoblasts. Human placental explants also proved our finding, in which STAT3 was activated and LC3B-II levels were increased by CV-MSC treatment. Conclusions Our data suggest that CV-MSC-dependent activation of JAK2/STAT3 signalling is a prerequisite for upregulation of autophagy in trophoblasts.