Prostaglandin E stimulates anion and fluid secretion triggered by lipopolysaccharide in rat vaginal epithelium.

Prostaglandin E (PGE) is a principal lipid mediator mediating various biological processes including immune responses and fluid secretion. As the first line of host defense against infection, vaginal epithelium plays orchestrated roles in vaginal innate immunity. However, the effect of PGE triggered by pro-inflammatory stimuli on vaginal epithelium remains elusive. This study aimed to investigate the regulatory role of PGE on vaginal epithelium after lipopolysaccharide (LPS) stimulation. RT-PCR and western blot analysis revealed that E-prostanoid (EP) receptors EP2 and EP4 were expressed in rat vagina. Basolateral application of PGE induced anion secretion mediated by cystic fibrosis transmembrane conductance regulator (CFTR) via EP-adenylate cyclase-cAMP signaling pathway in rat vaginal epithelial cells. The in vivo study showed that PGE promoted fluid secretion in rat vagina. Moreover, LPS stimulation facilitated cyclooxygenase-dependent PGE synthesis and vaginal fluid secretion in vivo. Conclusively, LPS stimulation triggered epithelium-derived PGE production in vaginal epithelium, leading to CFTR-mediated anion secretion and luminal flushing. This study provides valuable insights into the physiological role of PGE during vaginal bacterial infection.