Adolescent exposure to a mixture of per- and polyfluoroalkyl substances (PFAS) depletes the ovarian reserve, increases ovarian fibrosis, and alters the hippo pathway in adult female mice

Per- and polyfluoroalkyl substances (PFAS) are synthetic chemicals known for their environmental persistence and resistance to biodegradation. This study investigated the impact of adolescent exposure to a PFAS mixture on adult ovarian function. Female CD-1 mice were orally exposed to vehicle control or a PFAS mixture (comprised of perfluorooctanoic acid [PFOA], perfluorooctanesulfonic acid [PFOS], undecafluoro-2-methyl-3-oxahexanoic acid [GenX/HFPO-DA], and perfluorobutanesulfonic acid [PFBS]) for 15 days. After a 42-day recovery period, reproductive hormones, ovarian fibrosis, and ovarian gene and protein expression were analyzed using ELISA, Picrosirius red (PSR) staining, qPCR, and immunoblotting, respectively. Results revealed that PFAS exposure did not affect adult body or organ weight, although ovarian weight slightly decreased. PFAS exposed mice exhibited a disturbed estrous cycle, with less time spent in proestrus than control mice. Follicle counting indicated a reduction in primordial and primary follicles. Serum analysis revealed no changes in steroid hormones, follicle-stimulating hormone, or anti-Müllerian hormone, but a significant increase in luteinizing hormone was observed in PFAS-treated mice. Ovaries collected from PFAS treated mice had increased mRNA transcripts for steroidogenic enzymes and fatty acid synthesis-related genes. PFAS exposure also increased collagen content in the ovary. Additionally, serum tumor necrosis factor-α levels were higher in PFAS treated mice. Finally, transcripts and protein abundance for Hippo pathway components were upregulated in the ovaries of the PFAS treated mice. Overall, these findings suggest that adolescent exposure to PFAS can disrupt ovarian function in adulthood.