Kisspeptin-10 Improves Gestational Diabetes Mellitus Symptoms in Rats by Suppressing Insulin Resistance in Placental Trophoblast Cells by Activating the Cyclic AMP/Protein Kinase A Pathway

Gestational diabetes mellitus (GDM) is a common pregnancy complication that leads to insulin resistance (IR) and adversely affects both maternal and fetal health. Kisspeptin-10 (Kp-10), a peptide acting via G Protein-Coupled Receptor 54 (Gpr54), has shown potential in modulating insulin secretion, but its role in GDM remains unclear. This study explores Kp-10's therapeutic effects on GDM by targeting IR in placental tissues. We used GDM rat models (induced by a high-fat diet and streptozotocin) and high-glucose-treated HTR8/SVneo trophoblast cells to investigate Kp-10's effects on glucose metabolism, insulin signaling, and the cAMP/PKA pathway. Our results show that Gpr54 expression was significantly downregulated in the placental tissues of GDM rats, which was associated with impaired glucose uptake and IR. Kp-10 treatment improved fasting blood glucose (FBG) levels, insulin sensitivity, and fetal outcomes, including increased fetal weight and decreased fetal blood glucose. Moreover, Kp-10 restored the cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) signaling pathway and enhanced glucose uptake by upregulating Glut-4, Insr, and Irs1 expression in both placental tissues and HTR8/SVneo cells. The effects of Kp-10 were reversed by the cAMP inhibitor SQ22536, confirming the involvement of the cAMP/PKA pathway in its anti-IR effects. Our findings suggest that Kp-10 has the potential as a therapeutic agent for alleviating IR in GDM and improving maternal–fetal outcomes.