Supplementation of oleic acid, stearic acid, palmitic acid and β-hydroxybutyrate increase H3K9me3 in endometrial epithelial cells of cattle cultured in vitro.

There is growing evidence that greater than homeostatic blood concentrations of nonesterified fatty acids (NEFAs) and β-hydroxybutyrate (BHBA) have negative consequences on dairy cow's fertility, but effects on cell homeostasis in the reproductive system is not completely understood. In this study, lipids accumulation, reactive oxygen species (ROS) concentrations, abundance of gene transcripts, and immunofluorescence signal of H3K4me3 and H3K9me3 were evaluated in endometrial epithelial cells of cattle cultured with NEFAs (Oleic (OA), Stearic (SA) and Palmitic (PA) acids), BHBA, NEFAs + BHBA or each of the three NEFAs alone. The cellular lipids were in greater concentrations as a result of NEFAs + BHBA, NEFAs, SA or OA supplementation, but not by BHBA or PA. The ROS concentrations were greater when there were treatments with NEFAs + BHBA, NEFAs or BHBA. The relative mRNA abundance for genes involved in the regulation of apoptosis (XIAP), glucose transport (GLUT3), and DNA methylation (DNMT1) were greater when there were NEFAs + BHBA, but not NEFAs, BHBA, OA, SA or PA treatments. The immunofluorescence signal for H3K9me3 was greater when there were NEFAs + BHBA, NEFAs or PA, but not by BHBA, OA or SA treatments. These findings indicate that NEFAs and BHBA have an additive effect on endometrial cells of cattle by altering epigenetic markers and the expression of genes controlling important cellular pathways. Furthermore, there was cellular lipid accumulation and increased H3K9me3 in cultured bovine endometrial cells that was mainly induced by OA and PA treatments, respectively.