1α,25(OH)(2)D(3) Promotes the Autophagy of Porcine Ovarian Granulosa Cells as a Protective Mechanism against ROS through the BNIP3/PINK1 Pathway

Vitamin D (VD) is one of the important nutrients required by livestock; however, VD deficiency is reported to be widespread. Earlier studies have suggested a potential role for VD in reproduction. Studies on the correlation between VD and sow reproduction are limited. The aim of the current study was aimed to determine the role of 1,25-dihydroxy vitamin D(3) (1α,25(OH)(2)D(3)) on porcine ovarian granulosa cells (PGCs) in vitro to provide a theoretical basis for improving the reproductive efficiency of sows. We used chloroquine (autophagy inhibitor) and reactive oxygen species (ROS) scavenger N-acetylcysteine in conjunction with 1α,25(OH)(2)D(3) to explore the effect on PGCs. The results showed that 10 nM of 1α,25(OH)(2)D(3) increased PGC viability and ROS content. In addition, 1α,25(OH)(2)D(3) induces PGC autophagy according to the gene transcription and protein expression levels of LC3, ATG7, BECN1, and SQSTM1 and promotes the generation of autophagosomes. 1α,25(OH)(2)D(3)-induced autophagy affects the synthesis of E(2) and P(4) in PGCs. We investigated the relationship between ROS and autophagy, and the results showed that 1α,25(OH)(2)D(3)-induced ROS promoted PGC autophagy. The ROS-BNIP3-PINK1 pathway was involved in PGC autophagy induced by 1α,25(OH)(2)D(3). In conclusion, this study suggests that 1α,25(OH)(2)D(3) promotes PGC autophagy as a protective mechanism against ROS via the BNIP3/PINK1 pathway.