miR‐26a suppresses autophagy in swine Sertoli cells by targeting ULK 2

Contents A large number of micro RNA s (mi RNA s) have been detected from porcine testicular tissues thanks to the development of high‐throughput sequencing technology. However, the regulatory roles of most identified mi RNA s in swine testicular development or spermatogenesis are poorly understood. In our previous study, ULK 2 (uncoordinated‐51‐like kinase 2) was predicted as a target gene of miR‐26a. In this study, we aimed to investigate the role of miR‐26a in swine Sertoli cell autophagy. The relative expression of miR‐26a and ULK 2 levels has a significant negative correlation ( R 2  = .5964, p  ≤   .01) in nine developmental stages of swine testicular tissue. Dual‐luciferase reporter assay results show that miR‐26a directly targets the 3′ UTR of the ULK 2 gene (position 618–624). In addition, both the mRNA and protein expression of ULK 2 were downregulated by miR‐26a in swine Sertoli cells. These results indicate that miR‐26a targets the ULK 2 gene and downregulates its expression in swine Sertoli cells. Based on the expression of marker genes ( LC 3, p62 and Beclin‐1), overexpression of miR‐26a or knock‐down of ULK 2 inhibits swine Sertoli cell autophagy. Taken together, these findings demonstrate that miR‐26a suppresses autophagy in swine Sertoli cells by targeting ULK 2 .