Lactogenic hormones alter cellular and extracellular microRNA expression in bovine mammary epithelial cell?culture

摘要

Bovine milk contains not only a variety of nutritional ingredients but also microRNAs (miRNAs) that are thought to be secreted by the bovine mammary epithelial cells (BMECs). The objective of this study was to elucidate the production of milk-related miRNAs in BMECs under the influence of lactogenic hormones. According to a microarray result of milk exosomal miRNAs prior to cellular analyses, a total of 257 miRNAs were detected in a Holstein cow milk. Of these, 18 major miRNAs of interest in the milk were selected for an expression analysis in BMEC culture that was treated with or without dexamethasone, insulin, and prolactin (DIP) to induce a lactogenic differentiation. Quantitative polymerase chain reaction (qPCR) results showed that the expressions of miR-21–5p (P?=?0.005), miR-26a (P?=?0.016), and miR-320a (P?=?0.011) were lower in the DIP-treated cells than in the untreated cells. In contrast, the expression of miR-339a (P?=?0.017) in the cell culture medium were lower in the DIP-treated culture than in the untreated culture. Intriguingly, the miR-148a expression in cell culture medium was elevated by DIP treatment of BMEC culture (P?=?0.018). The medium-to-cell expression ratios of miR-103 (P?=?0.025), miR-148a (P?