MiR-190a regulates milk protein biosynthesis through the mTOR and JAK2–STAT5 signaling pathways by targeting PTHLH in buffalo mammary epithelial cells

[Display omitted] •Differentially expressed miRNA and mRNA are screened in the mammary gland of buffalo.•PTHLH promotes milk protein synthesis through mTOR and JAK2–STAT5 signaling pathways.•The PTHLH is the target gene of miR-190a.•The miR-190a inhibits milk protein synthesis by targeting PTHLH. Milk protein is a key quality indicator of milk, so elucidating its synthesis mechanism has been the focus of research in recent years. Studies have shown that both miRNAs and mRNA genes play important roles in the regulation of milk protein synthesis. In this study, a total of 7 and 4073 differentially expressed miRNA and mRNA genes were identified between early and peak lactation, respectively. Overexpression and knockdown experiments of parathyroid hormone like hormone gene (PTHLH) gene showed that it can promote milk protein synthesis in buffalo mammary epithelial cells (BuMECs) through mammalian target of rapamycin (mTOR) and janus kinase 2/signal transducer and activator of transcription 5 (JAK2–STAT5) signaling pathways, and the experiments treated with miR-190a mimic or inhibitor showed that miR-190a inhibited the expression of PTHLH gene. In addition, miR-190a inhibited milk protein synthesis by targeting PTHLH through mTOR and JAK2–STAT5 signaling pathways in BuMECs. Collectively, these findings reveal a novel miR-190a–PTHLH pathway that has a significant role in regulating milk protein synthesis.