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

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.

Automated summary

Milk protein synthesis is regulated by miRNAs and mRNA genes, with PTHLH playing a crucial role. This study identified differentially expressed miRNA and mRNA genes between early and peak lactation. Overexpression and knockdown experiments of PTHLH gene revealed its ability to promote milk protein synthesis in BuMECs through mTOR and JAK2-STAT5 signaling pathways. Additionally, miR-190a was found to inhibit milk protein synthesis by targeting PTHLH through the same signaling pathways in BuMECs. These findings highlight the significance of the miR-190a-PTHLH pathway in regulating milk protein synthesis.