Background: Bovine milk contains not only a variety of nutritional ingredients but also micro RNAs(mi RNAs) that are thought to be secreted by the bovine mammary epithelial cells(BMECs). The objective of this study wa...Background: Bovine milk contains not only a variety of nutritional ingredients but also micro RNAs(mi RNAs) 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 mi RNAs in BMECs under the influence of lactogenic hormones.Results: According to a microarray result of milk exosomal mi RNAs prior to cellular analyses, a total of 257 mi RNAs were detected in a Holstein cow milk. Of these, 18 major mi RNAs 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(q PCR) results showed that the expressions of mi R-21–5p(P = 0.005), mi R-26a(P = 0.016), and mi R-320a(P = 0.011) were lower in the DIP-treated cells than in the untreated cells. In contrast, the expression of mi R-339a(P = 0.017) in the cell culture medium were lower in the DIP-treated culture than in the untreated culture. Intriguingly, the mi R-148 a expression in cell culture medium was elevated by DIP treatment of BMEC culture(P = 0.018). The medium-to-cell expression ratios of mi R-103(P = 0.025), mi R-148a(P < 0.001), and mi R-223(P = 0.013) were elevated in the DIP-treated BMECs, suggesting that the lactogenic differentiation-induced secretion of these three mi RNAs in BMECs. A bioinformatic analysis showed that the mi RNAs down-regulated in the BMECs were associated with the suppression of genes related to transcriptional regulation, protein phosphorylation, and tube development.Conclusion: The results suggest that the mi RNAs changed by lactogenic hormones are associated with milk protein synthesis, and mammary gland development and maturation. The elevated mi R-148 a level in DIP-treated BMECs may be associated with its increase in milk during the lactation period of cows.展开更多
基金supported by the Japan Society for the Promotion of Science (JSPS KAKENHI 25660220) to S.M.
文摘Background: Bovine milk contains not only a variety of nutritional ingredients but also micro RNAs(mi RNAs) 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 mi RNAs in BMECs under the influence of lactogenic hormones.Results: According to a microarray result of milk exosomal mi RNAs prior to cellular analyses, a total of 257 mi RNAs were detected in a Holstein cow milk. Of these, 18 major mi RNAs 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(q PCR) results showed that the expressions of mi R-21–5p(P = 0.005), mi R-26a(P = 0.016), and mi R-320a(P = 0.011) were lower in the DIP-treated cells than in the untreated cells. In contrast, the expression of mi R-339a(P = 0.017) in the cell culture medium were lower in the DIP-treated culture than in the untreated culture. Intriguingly, the mi R-148 a expression in cell culture medium was elevated by DIP treatment of BMEC culture(P = 0.018). The medium-to-cell expression ratios of mi R-103(P = 0.025), mi R-148a(P < 0.001), and mi R-223(P = 0.013) were elevated in the DIP-treated BMECs, suggesting that the lactogenic differentiation-induced secretion of these three mi RNAs in BMECs. A bioinformatic analysis showed that the mi RNAs down-regulated in the BMECs were associated with the suppression of genes related to transcriptional regulation, protein phosphorylation, and tube development.Conclusion: The results suggest that the mi RNAs changed by lactogenic hormones are associated with milk protein synthesis, and mammary gland development and maturation. The elevated mi R-148 a level in DIP-treated BMECs may be associated with its increase in milk during the lactation period of cows.
