MicroRNA-216b inhibits heat stress-induced cell apoptosis by targeting Fas in bovine mammary epithelial cells

Abstract

Heat stress affects milk yield and quality in lactating dairy cows in summer. Bovine mammary epithelial cells (bMECs) play a key role in milk secretion, and microRNAs (miRNAs) regulate numerous functions of bMEC. Previous reports have verified that miR-216b regulated cell apoptosis through repressing target genes in several cancer cells. So, our purpose was to explore the potential involvement of miR-216b in heat stress-induced cell apoptosis in bMECs. Firstly, the heat stress model was constructed and we found that apoptotic rates of bMECs significantly increased under heat stress. The expression of miR-216b, Bax mRNA, and caspase-3 mRNA was upregulated. However, Bcl-2 mRNA level was detected to differentially downregulated. Overexpression of miR-216b remarkably downregulated the expression of caspase-3 and Bax mRNA and protein, and the mRNA and protein level of Bcl-2 was increased. Inhibition of miR-216b increased the activity of caspase-3 and Bax, and the level of Bcl-2 was inhibited. Moreover, Fas was identified as a target gene of miR-216b through bioinformatic analysis and dual-luciferase reporter assay. Fas activity was significantly inhibited and enhanced respectively after transfecting miRNA mimics and inhibitor. Finally, inhibition of Fas via the small interfering RNA (siRNA) also inhibited cell apoptosis induced by heat stress. Taken together, our results indicated that miR-216b exerted as an anti-apoptotic effect under heat stress in bMECs by targeting Fas.

Characterization of Short-Term Heat Stress in Holstein Dairy Cows Using Altered Indicators of Metabolomics, Blood Parameters, Milk MicroRNA-216 and Characteristics

“…Cortisol is released from the adrenal cortex, which allows the body to continue to stay on high alert. Acutely, catabolic mechanisms of cortisol provide energy to the body [ 13 ]. The higher cortisol levels observed in HTHH group were in line with the higher heart rate in the corresponding group in this study.…”

“…Furthermore, microRNAs (miRNAs) was recognized as an important regulator of gene expression beyond the transcriptional stage and various biological reactions such as development, apoptosis, differentiation, and viral infection [ 12 ]. Additionally, miRNAs regulate numerous functions of bovine mammary epithelial cells (bMECs), which play a putative role in milk secretion [ 13 ]. In humans, it has been documented that miR-216 can regulate cell apoptosis through repressing target genes in several cancer cells [ 13 ].…”

“…Additionally, miRNAs regulate numerous functions of bovine mammary epithelial cells (bMECs), which play a putative role in milk secretion [ 13 ]. In humans, it has been documented that miR-216 can regulate cell apoptosis through repressing target genes in several cancer cells [ 13 ]. Likewise in this study, we aimed at exploring the potential involvement of miR-216 in the milk of heat stressed cows.…”

Effect of heat stress on udder health of dairy cows

“…Heat stress also reduces phagocytosis capacity and the oxidative burst of bovine PMN, which together with having the negative effect on the immune system may explain the increased susceptibility to IMI (Lecchi et al, 2016). Cai et al (2018) investigated apoptosis of bMECs under heat stress and found a differential expression of apoptotic genes and miRNAs which led to increased apoptosis. However, they also detected an antiapoptotic effect of miR-216b under heat stress in bMECs by targeting Fas.…”

“…Cai et al . (2018) investigated apoptosis of bMECs under heat stress and found a differential expression of apoptotic genes and miRNAs which led to increased apoptosis. However, they also detected an anti-apoptotic effect of miR-216b under heat stress in bMECs by targeting Fas.…”