Expression of short chain fatty acid receptors and pro-inflammatory cytokines in utero-placental tissues is altered in cows developing retention of fetal membranes

IntroductionRetention of fetal membranes (RFM) is an economically important condition in dairy cattle disturbing the health and production in affected animals. In spite of extensive research, pathogenesis for RFM and identification of a predictive marker for the condition still remains elusive. Since expulsion of fetal membranes in an inflammatory process, studying the expression of inflammatory molecules is expected to give an idea about the pathogenesis of RFM.MethodsExpression of pro-inflammatory cytokines, short chain fatty acid (SCFA) receptors and adhesion molecules was studied using qRT-PCR in the utero-placental tissues obtained from the cows that expelled fetal membranes normally (n = 12) and from the cows that developed RFM (n = 12). Concentrations of SCFAs were estimated in the utero-placental tissues using Gas Chromatography.ResultsThe concentration of butyrate in the utero-placental tissue extract was 3–4 times lower, and GPR41 and GPR43 mRNA expression was 7.7–10.0 and 3.4–4.4 folds lower (p < 0.05) in cows that developed RFM compared to those that expelled the fetal membranes normally. The expression of IL-1, IL-6, IL-8, TNF-α, ICAM and PECAM was higher (p < 0.05) in the cows that normally expelled the fetal membranes compared to those that developed RFM.DiscussionSince a clear association of butyrate levels, expression of pro-inflammatory cytokines, adhesion molecules and SCFAs receptors was observed with expulsion of fetal membranes, modulating the levels of these molecules prior to parturition might help in reducing the incidence of RFM in cows.ConclusionInflammatory response is essential for normal expulsion of fetal membranes and that inadequate or altered expression of pro-inflammatory cytokines, adhesion molecules and SCFA receptors is associated with RFM in cows.