Abstract:

【Objective】 MicroRNA (miRNA) is a kind of short non-coding RNA about 22-23 nucleotides in length. The present study was performed to investigate the effects and molecule mechanism of miRNA -24 on mammary epithelial cells growth and apoptosis in response to high temperature. 【Method】 Bovine mammary epithelial cells were cultured in vitro, and gene silencing techniques were used to inhibit the expression of miRNA-24 in mammary epithelial cells which in response to heat stress. Cell proliferation was measured by cell count method. Apoptosis of cells was analyzed by Hoechst33342/PI fluorescent staining and FCM. The expression of apoptosis correlation factors caspases-8 and caspases-3 were detected by western blot. 【Results】 The results showed that miRNA-24 gene silencing in mammary epithelial cells significantly increased (P＜0.05) the proliferation of cells although these cells were treated at high temperature beforehand. In contrast, the apoptosis of these cells were decreased (P＜0.05), the expression of caspases-8 and caspases-3 were also decreased after miRNA-24 gene silencing. 【Conclusion】 miRNA-24 have important roles in regulation of glandular tissue development, inhibition of miRNA-24 may rescue heat stress-induced apoptosis of bovine mammary epithelial cells and promote the cells growth and development.

Key words: MicroRNA-24, heat stress, mammary epithelial cell, apoptosis, proliferation, bovine