The modulation of PERK/ATF4/CHOP signaling by Neurokinin 3 receptor antagonists to ameliorate hepatic steatosis and endocrine dysfunction in PMOS mice - targeting the implication of endoplasmic reticulum stress.

Lipotoxicity contributes to polyendocrine metabolic ovarian syndrome (PMOS) pathogenesis by inducing hyperandrogenism (HA) and insulin resistance (IR), while excess testosterone triggers endoplasmic reticulum (ER) stress and the unfolded protein response (UPR) in PMOS models. However, ER stress and UPR activation under HA-obese conditions remain unexplored in granulosa cells (GCs) and PMOS mouse liver and ovary. Neurokinin 3 receptor antagonists (NK3Ra) reverse PMOS metabolic and reproductive impairments; therefore we established an HA-obese model by exposing KGN cells to palmitic acid (PA) and dihydrotestosterone (DHT), and an HFD-letrozole PMOS mouse model, both treated with NK3Ra. In KGN cells, ER and mitochondrial ultrastructure disruption was observed by TEM, UPR sensor protein and gene expression/phosphorylation was analyzed by qPCR and western blotting, and NK3Ra rescue of cell viability was evaluated, alongside peripheral and tissue biochemical/hormonal assays, immunohistochemistry for AMH, UPR sensor and cascade proteins, and redox metabolism assays. NK3Ra alleviated ER stress by modulating the PERK-ATF4-CHOP axis, improving steroidogenesis, redox homeostasis, and viability in HA-obese models. In PMOS mice, hepatic steatosis was reversed with associated downregulation of CHOP, decreased de novo lipogenic gene expression, and increased superoxide dismutase activity, while estrous cyclicity and steroid hormone metabolism were restored, accompanied by reduced ovarian ATF4, CHOP, and GRP78 expression by NK3Ra activity. Collectively, our findings suggest that NK3Ra alleviates lipotoxic-HA-induced ER stress via the modulation of the PERK-ATF4-CHOP pathway, thereby ameliorating metabolic and endocrine aberrations in PMOS.