Aquaporin 7 is upregulated through the PI3K-Akt pathway and modulates decidualisation of endometrial stromal cells

ContextAquaporin 7 (AQP7) is selectively expressed in decidualised endometrial stromal cells (ESCs) of mice surrounding the embryonic implantation sites. However, the roles of AQP7 and the underlying mechanism that regulates AQP7 expression in endometrial decidualisation after implantation are still unclear.AimsThis study aimed to investigate the role of the PI3K-Akt pathway in regulating the expression of AQP7 in ESCs and decidualisation.MethodsPrimary ESCs of pregnant mice were isolated to establish in vitro decidualisation models. PI3K inhibitor LY294002 was added to the decidualisation models, then AQP7 expression, changes in decidualised ESC morphology and expression of decidualisation marker molecules were examined.Key resultsAQP7 knockdown reduced the proliferation and differentiation of ESCs with in vitro induced decidualisation. Furthermore, when the activity of PI3K was inhibited by LY294002, the expression of AQP7 in decidualised ESCs was decreased and both the proliferation and differentiation of ESCs were significantly reduced.ConclusionsThis indicates that AQP7 is a key molecule involved in endometrial decidualisation and the expression of AQP7 is upregulated through activation of the PI3K-Akt pathways, which promotes the proliferation and differentiation of the ESCs, thus affecting occurrence of decidualisation.ImplicationsThis study may provide a new biomarker for the diagnosis of infertility and a new drug target for the prevention and treatment of infertility. Endometrial decidualisation plays an important role in embryo implantation and the successful establishment and maintenance of pregnancy. Our present results showed the expression of AQP7 was upregulated though PI3K-Akt pathway activation, which might promote proliferation and differentiation of the ESCs, thus affecting occurrence of decidualisation. This study explores the mechanisms that influence decidualisation. Moreover, this might provide a new biomarker for the diagnosis of infertility and a new drug target for the prevention and treatment of infertility. Image supplied by Min Liu.