LncRNA MEG3 regulates ASK1/JNK axis-mediated apoptosis and autophagy via sponging miR-23a in granulosa cells of yak tertiary follicles.

Apoptosis and autophagy in granulosa cells (GCs) are highly related to follicular development and atresia. It has also been reported that they are related to LncRNA MEG3, miR-23a and apoptosis signal-regulating kinase 1 (ASK-1). However, their relationship to follicular development and the extent to which follicle stimulating hormone (FSH) or luteinizing hormone (LH) can regulate this process remain unknown. Here, we found that ASK1 and JNK were expressed in the GCs of gonadotropin-dependent follicles, and those levels were significantly higher (p < 0.05) in yak Tertiary follicles compared to that of Secondary follicles and Graafian follicles. Then, the effect of LncRNA MEG3 / miR-23a on apoptosis and autophagy via ASK1/JNK (c-Jun N-terminal kinase) in yak GCs was studied. Overexpressing LncRNA MEG3 reduced miR-23a levels and p-967 protein expression, but enhanced ASK1 and JNK mRNA levels as well as t-ASK1, p-845, t-JNK, and p-JNK proteins levels. And Up-regulation of LncRNA MEG3 promoted apoptosis while attenuating autophagy. The targeting relationship between miR-23a and the binding sites of LncRNA MEG3 and ASK1 was also confirmed with the dual luciferase reporter assay. And, the relationship between LncRNA MEG3 and miR-23 a was observed as a negative feedback regulation, and changes in LncRNA MEG3 and miR-23a levels can alter the expression of ASK1/JNK axis in yaks GCs. In addition, FSH (10 μg/mL) or LH (100 μg/mL) ability to reverse the effects of LncRNA MEG3 on miR-23a levels and ASK1/JNK axis-mediated apoptosis and autophagy was verified in yak GCs. This is significantly beneficial for decreasing abnormal follicular atresia for yaks tertiary follicles. [Display omitted] • LncRNA MEG3, miR-23a and ASK-1 were related with apoptosis and autophagy, but their effect on follicules of yak remain unknown. • The level of ASK1 and JNK were higher in yak Tertiary follicles compared to Secondary and Graafian follicles. • LncRNA MEG3 reduced miR-23a levels, but enhanced ASK1-JNK axis levels, and promoted apoptosis while attenuating autophagy. • miR-23a can directly targeted LncRNA MEG3, and the relationship of LncRNA MEG3 and miR-23a was observed as a negative feedback regulation. • FSH (10 μg/mL) and LH (100 μg/mL) ability to reverse the effects of LncRNA MEG3 on miR-23a and ASK1/JNK axis. [ABSTRACT FROM AUTHOR]