An environmentally relevant mixture of per- and polyfluoroalkyl substances (PFAS) impacts proliferation, steroid hormone synthesis, and gene transcription in primary human granulosa cells

PFOS exposure impairs porcine oocyte maturation and embryo development via mitochondria-dependent ferroptosis

Perfluorooctane sulfonate (PFOS) is a widely utilized chemical known for its exceptional environmental stability over extended periods, its significant potential to bioaccumulate in living organisms, and its considerable risks to both health and the environment. Several studies have suggested that PFOS may pose reproductive risks in mammals; however, the exact mechanisms driving these effects are not well understood. In this study, we explored the possible mechanisms by which PFOS toxicity affects the maturation of mammalian oocytes and the embryonic development employing porcine oocytes as a model system. SMART-seq results suggested that PFOS may affect oocyte maturation through mechanisms involving ferroptosis, autophagy, and alterations in membrane structure. Our results suggest that PFOS exposure adversely affects mitochondrial function and structure, thereby influencing peroxisome biogenesis and contributing to oxidative stress. Most importantly, we found that exposure to PFOS significantly elevated Fe2+ levels, an indicator associated with ferroptosis in oocytes. Furthermore, malondialdehyde (MDA) levels in the PFOS group were significantly higher than those in the control group. Additionally, the mRNA expression levels of PCBP1 and PCBP2, which are related to ferroptosis, as well as the expression level of P53, were significantly reduced in the PFOS group. Overall, exposure to PFOS in vitro results in mitochondrial damage in porcine oocytes, which induces lipid peroxidation and subsequently leads to the occurrence of ferroptosis.

Mitochondrial activity and steroid secretion in mouse ovarian granulosa cells are suppressed by a PFAS mixture

The accumulation of a number of per- and polyfluoroalkyl substances (PFASs) in ovarian follicular fluid (FF) has been documented, raising serious questions about their impact on female fertility. Here, we tested the hypothesis that a mixture of PFASs acts in a paracrine manner on granulosa cells (GCs) as a metabolism-disrupting chemical. We selected perfluorooctane sulfonate (PFOS; 22.4 ng/mL), perfluorooctanoic acid (PFOA; 14.5 ng/mL), perfluorohexane sulfonate (PFHxS; 21.3 ng/mL), perfluorodecanoic acid (PFDA; 0.9 ng/mL), perfluoroheptane sulphonate (PFHpA; 0.6 ng/mL), perfluoroundecanoic acid (PFUnDA; 0.4 ng/mL), and perfluorononanoic acid (PFNA; 2 ng/mL), which were the most commonly detected PFASs in FF of women undergoing assisted reproductive technology treatment. Exposure of mouse GCs to the PFAS mixture decreased the amount of active mitochondria and the mitochondrial membrane potential, which correlated with a reduction in ATP production and inhibition of oxidative phosphorylation (OXPHOS). At the same time, expression of the mitochondrial membrane-associated steroidogenic enzyme 3-beta-hydroxysteroid dehydrogenase (3βHSD) and production of the major steroids progesterone and estradiol were decreased. In addition, expression and activity of superoxide dismutase 1 (SOD1), an enzyme that neutralizes reactive oxygen species (ROS), were decreased while ROS levels and lipid peroxidation were increased without cell death, indicating that the PFAS mixture had subtoxic effects. Our results show that PFAS mixtures, at concentrations similar to those found in human FF led to GC dysfunction by impairing mitochondrial function and steroid secretions and therefore may have implications for reproductive health.

Per- and Polyfluoroalkyl Substances and Female Health Concern: Gender-based Accumulation Differences, Adverse Outcomes, and Mechanisms

The deleterious health implications of perfluoroalkyl and polyfluoroalkyl substances (PFAS) are widely recognized. Females, in contrast to males, exhibit unique pathways for PFAS exposure and excretion, leading to complex health outcomes. The health status of females is largely influenced by hormone-related processes. PFAS have been reported to be associated with various aspects of female health, including reproductive system disorders and pregnancy-related diseases. In this article, we provide insights into the correlations between PFAS and female-prevalent diseases. Current epidemiological and toxicological evidence has demonstrated that the adverse effects of PFAS on the health of the female reproductive system are primarily attributed to the disruption of the hypothalamic-pituitary-gonadal (HPG) axis and hormonal homeostasis. However, these findings do not sufficiently elucidate the intricate associations between PFAS and specific diseases. Furthermore, autoimmune disorders, another category that is more prevalent in women compared to men, require additional investigation. Immune biomarkers pertinent to autoimmune disorders have been observed to be influenced by PFAS exposure, although epidemiological evidence is insufficient to substantiate these relations. Further thorough exploration encompassing epidemiological and toxicological studies is essential to elucidating the inherent influence of PFAS on human pathologies. Additionally, comprehensive investigations into female health issues beyond their reproductive functions is essential.

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, perfluorooctanesulfonic acid, undecafluoro-2-methyl-3-oxahexanoic acid, and perfluorobutanesulfonic acid) for 15 d. After a 42-d recovery period, reproductive hormones, ovarian fibrosis, and ovarian gene and protein expression were analyzed using ELISA, Picrosirius red 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.

Developmental perfluorooctane sulfonic acid exposure exacerbates house dust mite induced allergic responses in adult mice

Perfluorooctane sulfonic acid (PFOS) is a long-chain per- and polyfluoroalkyl substance (PFAS), a persistent organic pollutant, which has been used in aqueous film-forming foams. Emerging epidemiological evidence indicates a significant body burden of PFOS is observed in the lungs. Furthermore, developmental PFOS exposure dysregulates lung development and exacerbates eosinophilic inflammation, which are critical risk factors for asthma. However, it is unknown whether PFOS exerts sex-dependent effects on house dust mite (HDM) induced asthmatic progression and allergic inflammation. In this study, timed pregnant Balb/cJ dams were dosed orally via PFOS (1.0 mg/kg/d) spiked or vehicle control mealworms from gestational day (GD) 0.5 to postnatal day (PND) 21. Subsequently, HDM (30 μg/day) was administered starting at PND 77-82 for 10 days, and the mice were sacrificed 48 h after their final treatment. The serum and lung PFOS concentrations were 3.391 ± 0.189 μg/mL and 3.567 ± 0.1676 μg/g in the offspring, respectively. Male mice exposed to PFOS + HDM showed higher total cell counts in bronchoalveolar lavage fluid (BALF), macrophage counts, and eosinophil counts compared to mice exposed to HDM alone. Female mice exposed to PFOS + HDM had increased BALF eosinophil percentage, mucous production, alternatively activated (M2) macrophage polarization, and M2-associated gene expression compared to female mice exposed to HDM alone. PFOS exposure had no significant effect on HDM-induced IL-4, IL-5, or IL-13, but RANTES was further elevated in female mice. Overall, our data suggest that developmental PFOS exposure increased the risk of exacerbated eosinophilic inflammation and M2 polarization, which were more severe in female mice, suggesting sex-dependent developmental effects of PFOS on allergic airway responses.