Effects of the androstenedione-MSMO1 axis on proliferation, apoptosis, and steroid hormone synthesis and secretion in porcine granulosa cells.

The quality of follicular development is a primary determinant of reproductive performance in female livestock and is governed by the functional state of granulosa cells (GCs). Androstenedione (ASD), a key steroid precursor converted within the ovary to estrogens and androgens via multiple pathways, has recognized biological roles. However, its direct regulatory actions in GCs and their consequences for sow fertility remain insufficiently defined. By comparing ovarian metabolomes from high and low reproductive performance sows, we pinpointed differentially abundant metabolites and prioritized ASD for mechanistic investigation. We then systematically characterized ASD function in primary porcine GCs in vitro and validated mechanisms using transcriptomics and gene overexpression. Our data support a model in which ASD acts via an ASD-MSMO1 axis and may engages canonical TGF-β, AMPK, p53, Hedgehog, Apelin, FoxO, and Hippo signaling pathways to orchestrate multilayered regulation of GC physiology, promoting proliferation, enhancing estrogen and progesterone synthesis and secretion, and inhibiting apoptosis. These findings provide mechanistic insights and suggest feasible strategies to improve fertility in female livestock.