RNA-seq reveals the role of miR-29c in regulating inflammation and oxidative stress of bovine mammary epithelial cells

Purpose: to detect expression profile of differentially expressed mRNAs during bovine mammary epithelial cells line (MAC-T) transfected with miR-29c inhibitor or negative control (NC) inhibitor in vitro. Methods: bovine mammary epithelial cells were transfected with miR-29c inhibitor or negative control (NC) inhibitor to assess the expression profiles of mRNAs using RNA-seq. Results: a total of 42 up-regulated and 27 down-regulated mRNAs were found in the miR-29c inhibitor transfected group compared with the NC inhibitor group. Conclusion: the inhibition of miR-29c in MAC-T cells could lead to the up-regulation of 42 mRNAs and the down-regulation of 27 mRNAs. The functional enrichment of the differentially expressed mRNAs indicated that miR-29c might be a potential regulator of oxidative stress and inflammatory response in MAC-T through multiple genes, such as FOXO1, TNF-α and BoLA-DQA5, which enriched in stress-activated MAPK cascade, Epstein-Barr virus infection and inflammatory bowel disease signaling pathways. The above results imply that miR-29c plays an important role in the steady state of bMECs or bovine mammary glands and may be a potential therapeutic target for mastitis in dairy cows. Bovine mammary epithelial cells previously frozen in liquid nitrogen were thawed and cultured in in one 6-well plates. When bovine mammary epithelial cell monolayers reached 60%~70% confluence, three wells were transfected with NC inhibitor (100 nM), and the remaining three wells were transfected with miR-29c inhibitor (100 nM), which were used as the negative control group and the experimental group, respectively. Subsequently, all samples were used to perform the RNA-seq.