Modulation of ovine SBD-1 expression by 17beta-estradiol in ovine oviduct epithelial cells

17beta-estradiol (E2) induced release of SBD-1 in ovine oviduct epithelial cells. SBD-1 expression was mediated through G-protein-coupled receptor 30 (GPR30) and Estrogen Receptors (ERs) activation in ovine oviduct epithelial cell. Inhibition of gene expression of protein kinase A (PKA), protein kinase C (PKC), and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) led to a decreased SBD-1 expression.Taken together, E2-induced up-regulation of SBD-1 expressions were GPR30-dependent during prophase and ERs-dependent during later-stage in ovine oviduct epithelial cells, and we assume that the effect was completed by the PKA, PKC, and NF-κB pathways simultaneous.Ovine oviduct epithelial cells are effective barriers for microorganisms and actively participate in the initiation of innate host defense. Unfortunately, salpingitis is the one of most common and serious infections in reproductive system diseases [1]. However, there has been a dramatic worldwide increase in antibiotic resistance in pathogens in the past several decades. Thus, there is an urgent need to develop new and innovative, non-antibiotic approaches to prevent and manage this disease [2,3]. Defensins are antimicrobial peptides of innate immunity functioning by non-specific binding to anionic phospholipids in bacterial membranes.β-defensins are produced directly by epithelial cells, and combat infection both through direct microbicidal action and by modulation of cell-mediated immunity [4-7]. These peptides are involved in the innate immunity mechanisms and act directly against bacteria, viruses, and fungi, due to their bactericidal and cytotoxic activity [8]. Moreover, they have been suggested as effector molecules in host defense, interacting with many target cells and tissues [9]. So far, only two β-defensin genes have been identified in sheep: β-defensin 1 (SBD-1) and β-defensin 2 (SBD-2), although genomic studies suggest more have yet to be discovered [10]. Recent studies have rev