MicroRNAs (miRNAs) are implicated in swine spermatogenesis via their regulations of cell proliferation, apoptosis, and differentiation. Recent studies indicated that miR-34c is indispensable in the late steps of spermatogenesis. However, whether miR-34c plays similar important roles in immature porcine Sertoli cells remain unknown. In the present study, we conducted two experiments using a completely randomised design to study the function roles of miR-34c. The results from experiment I demonstrated that the relative expression level of miR-34c in swine testicular tissues increased (P=0.0017) quadratically with increasing age, while the relative expression level of SMAD family member 7 (SMAD7 ) decreased (P=0.0009) with curve. Furthermore, miR-34c expression levels showed a significant negative correlation (P=0.013) with SMAD7 gene expression levels. The results from experiment II indicated that miR-34c directly targets the SMAD7 gene using a luciferase reporter assay, and suppresses (P<0.05) SMAD7 mRNA and protein expressions in immature porcine Sertoli cells. Overexpression of miR-34c inhibited (P<0.05) proliferation and enhanced (P<0.05) apoptosis in the immature porcine Sertoli cells, which was supported by the results from the Cell Counting Kit-8 (CCK-8) assay, the 5-Ethynyl-2´-deoxyuridine (EdU) assay, and the Annexin V-FITC/PI staining assay. Furthermore, knockdown of SMAD7 via small interfering RNA (siRNA) gave a similar result. It is concluded that miR-34c inhibits proliferation and enhances apoptosis in immature porcine Sertoli cells by targeting the SMAD7 gene.
Fund: This work was financially supported by the earmarked fund for China Agriculture Research System (CARS-36), the Hunan Provincial Natural Science Foundation of China (2018JJ3219 and 2018JJ2176), and the Excellent Doctoral Dissertation Cultivating Fund of Hunan Agricultural University, China (YB2015001). Authors would like to thank Yang Guan, Vanderbilt University, USA, for critical reading of the manuscript.
RAN Mao-liang, Tel: +86-731-84618176, E-mail: ranmaoliang0903@
Cite this article:
RAN Mao-liang, WENG Bo, CAO Rong, PENG Fu-zhi, LUO Hui, GAO Hu, CHEN Bin. 2019. miR-34c inhibits proliferation and enhances apoptosis in immature porcine Sertoli cells by targeting the SMAD7 gene. Journal of Integrative Agriculture,