Rescuing fertility: Itaconic acid prevents ovarian damage through NRF2-mediated pyroptosis pathways in diminished ovarian reserve models

Abstract

Background

Diminished ovarian reserve (DOR) is a major cause of infertility, often triggered by inflammation and oxidative stress. Pyroptosis, a form of programmed cell death, has been implicated in DOR pathogenesis. Itaconic acid (IA), an endogenous metabolite, is known for its anti-inflammatory and antioxidant properties. This study aimed to explore whether IA could alleviate lipopolysaccharide (LPS)-induced DOR in mice by inhibiting pyroptosis through the NRF2 pathway.

Methods

A DOR mouse model was established by administering LPS for 5 consecutive days, followed by IA treatment. Ovarian function was assessed by follicle count and hormone levels. Inflammatory markers, oxidative stress, and pyroptosis-related proteins were evaluated in both in vivo and in vitro models. The molecular mechanism was further investigated using inhibitors and molecular docking studies.

Results

IA significantly improved ovarian function in LPS-induced DOR mice by increasing the number of follicles and normalizing hormone levels. IA also reduced inflammation, oxidative stress, and pyroptosis, as evidenced by lower expression of NLRP3, cleaved-caspase-1, and N-GSDMD, while increasing NRF2 expression. In vitro, IA enhanced granulosa cell (GC) viability, reduced reactive oxygen species (ROS), and decreased pyroptosis in LPS-treated GCs. Additionally, the beneficial effects of IA were mediated via the NRF2 pathway, as NRF2 inhibition (ML385) reversed these improvements. Additionally, we identified GSDMD as a downstream target of IA, with inhibition of GSDMD ameliorating DOR progression and inflammatory responses.

Conclusion

IA alleviates LPS-induced DOR by reducing inflammation, oxidative stress, and pyroptosis through activation of the NRF2 signaling and direct inhibition of the GSDMD pathway. These findings suggest that IA may serve as a potential therapeutic agent for improving ovarian reserve and fertility.