Ovarian disrupting effects and mechanisms of long- and short-chain per- and polyfluoroalkyl substances in mice

Abstract

BackgroundThe extensive use of per- and polyfluoroalkyl substances (PFAS) has led to environmental contamination and bioaccumulation. Previous research linked PFAS exposure to female reproductive disorders, but the mechanism remains elusive. Further, most studies focused on legacy long-chain PFOA and PFOS, yet the reproductive impacts of other long-chain PFAS and short-chain alternatives are rarely explored.ObjectivesWe investigated the effects and mechanisms of long- and short-chain PFAS on the ovary and associated ovarian functions.MethodsA 3Din vitroovarian follicle culture system and anin vivomouse model, together with approaches of reverse transcription-quantitative polymerase chain reaction, enzyme-linked immunosorbent assay, RNA-sequencing, pharmacological treatment,in situzymography, histology,in situhybridization, analytical chemistry, and benchmark dose modeling (BMD), were used to test environmentally relevant exposure levels of six long- and short-chain PFAS on follicle maturation, hormone secretion, and ovulation.ResultsIn vitroexposure revealed that long-but not short-chain PFAS interfered with gonadotropin-dependent follicle maturation, ovulation, and hormone secretion. Mechanistically, long-chain perfluorononanoic acid (PFNA) acted as a peroxisome proliferator-activated receptor gamma (PPARγ) agonist in granulosa cells to disrupt follicle-stimulating hormone (FSH)-dependent follicle maturation, luteinizing hormone (LH)-stimulated ovulation, and associated gene regulatory pathways.In vivomouse exposure confirmed the ovarian accumulation of PFNA and the mechanism of PPARγ-mediated ovarian toxicities of PFNA observedin vitro. The BMD analysis ofin vitroandin vivoresults suggested human relevant exposure levels of long-chain PFAS in our study pose an extra risk of ovarian defects, with follicular rupture as the most sensitive endpoint.DiscussionUsingin vitrofollicle culture andin vivomouse models, we discovered that long-chain PFAS interfere with gonadotropin-dependent follicle maturation, hormone secretion, and ovulation, posing a non-negligible risk to women’s reproductive health including anovulation, irregular menstrual cycles, and sub- or infertility.