Human recombinant H2 relaxin induces AKT and GSK3β phosphorylation and HTR-8/SVneo cell proliferation

Relaxin is essential for trophoblast development during pregnancy. Evidence shows that relaxin increases trophoblast cell migration capacity. Here, we show the effect of relaxin on protein kinase B (AKT) activation and glycogen synthase kinase 3-beta (GSK3β) inactivation as well as on the proliferation of HTR-8/SVneo cells, a model of human extravillous trophoblast (EVT). HTR-8/SVneo cells were treated with different doses of human recombinant (rH2) relaxin in serum-deprived conditions and treated for increasing time with 1 ng/mL of rH2 relaxin. Western blot analysis was performed to detect pAKT, AKT, pGSK3β, GSK3β, and actin expression. Proliferation of HTR-8/SVneo cells was analyzed by MTS assay. rH2 relaxin treatment increased the ratio of pAKT/AKT, pGSK3β/GSK3β, and proliferation in HTR-8/SVneo cells. Furthermore, AKT and GSK3β activation by rH2 relaxin was inhibited by a phosphoinositide 3-kinase (PI3K) inhibitor. This study suggests that rH2 relaxin induces AKT and GSK3β phosphorylation as well as proliferation in HTR-8/SVneo cells.