Hydroxychloroquine alleviates cyclophosphamide-induced premature ovarian failure by attenuating granulosa cell senescence and modulating the mtDNA-cGAS pathway.

Cyclophosphamide (CTX) is a first-line chemotherapeutic agent for various cancers but is associated with a significant risk of ovarian dysfunction, which may even progress to premature ovarian failure (POF). Granulosa cell senescence is a key phenotypic manifestation of this process. Hydroxychloroquine (HCQ) exerts anti-senescence effects in age-related diseases; however, its efficacy in preventing CTX-induced ovarian damage remains elusive. We aimed to verify the protective effect of HCQ using a CTX-induced POF mouse model. In vitro validation was performed using the human ovarian granulosa cell line (KGN), which was treated with phosphoramide mustard (PM, the active metabolite of CTX) and HCQ. HCQ partially reversed CTX-induced impairment of ovarian function, reduced follicular depletion, and improved serum hormone levels as well as reproductive outcomes. HCQ attenuated CTX-induced cellular senescence, stabilized mitochondrial membranes, decreased reactive oxygen species (ROS) production and mitochondrial DNA (mtDNA) leakage, inhibited the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) signaling pathway, and suppressed the expression of senescence-associated secretory phenotype (SASP) factors. Collectively, our preclinical findings demonstrate that HCQ alleviates CTX-induced POF, which is associated with the mitigation of granulosa cell senescence and modulation of the mtDNA-cGAS signaling pathway.