PFOS exposure destroys the integrity of the blood-testis barrier (BTB) through PI3K/AKT/mTOR-mediated autophagy

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.

Unveiling the nexus between environmental exposures and testicular damages: revelations from autophagy and oxidative stress imbalance

Recent evidence consolidates the deleterious impact of environmental exposure on testicular damage. Environmental exposures can instigate testicular toxicity, causing damage to the Sertoli-Sertoli cell-mediated blood-testis barrier (BTB) integrity, alterations in hormone levels orchestrated by aberrant Leydig cells, and disruption of spermatogenesis. Despite diverse study designs and methodologies, a consensus is emerging on how environmental factors induce oxidative stress by elevating ROS levels, affecting autophagy through pathways such as the ROS-mediated mTOR signaling pathway, ultimately culminating in testicular damage. This review synthesizes existing literature on how environmental exposures, including metals, air pollutants, industrial contaminants, and pesticides, disturb testicular homeostasis via autophagy-mediated oxidative stress, highlighting recent significant advancements. It also explores interventions like antioxidant support and autophagy regulation to alleviate testicular damage. These findings underscore the importance of elucidating the mechanisms of autophagy influenced by environmental exposures in disrupting the equilibrium of oxidative stress, identifying potential drug targets, and establishing a groundwork for enhancing future treatments and clinical management of testicular injuries.

Additive effect of Bisphenol A and Pefluoro-sulphoctanoic acid exposure at subacute toxic levels, on a murine model of sertoli cell

PURPOSE

Endocrine disruptors (EDs) interfere with the endocrine system leading to health consquences and reproductive derangements. Most EDs are environmental pollutants whose risk evaluation is hampered by the simultaneous exposure to a number of chemicals. Here we investigated the possible mechanistic involvement of Sertoli cells, the nurse cell population in the seminiferous tubule, in the reproductive toxicity of Bisphenol A (BPA) and perfluoro-octane sulphonate (PFOS), two acknowledged EDs, at recognized subacute toxic levels.

METHODS

Mouse Sertoli cell line TM4 were exposed for 24 h to 40 ng/mL BPA or 30 ng/mL PFOS or their association. Cell proliferation was measuerd by MTT assay. Cell apoptosis was evaluated with Annexin-V/propidium iodide staining. Protein expression analysis was peformed by western blotting.

RESULTS

Compared to unexposed controls (100.0 ± 3.5%), cells exposed to BPA (79.5 ± 3.5%) or PFOS (76.0 ± 7.9%) showed reduced survival rate (P < 0.001 vs control). The exposure to the mixture of BPA and PFOS was associated with a further reduction of cell survival (63.9 ± 7.2%, P < 0.001 vs control) and an increase of the percentage of apoptotic cells (13.7 ± 4.6% control, 40.3 ± 13.5% BPA, PFOS 28.7 ± 5.6%, 67.1 ± 19.6% BPA + PFOS P = 0.001 vs control; P = 0.022 vs BPA). The exposure to the combination of BPA and PFOS was associated with Akt-signaling pathway activation and with the downstream caspase 3 cleavage. In addition, the exposure to the combination of BPA and PFOS was associated with NF-κB activation and increased expression of FasL.

CONCLUSION

Subacute toxic levels of BPA and PFOS display additive effects on Sertoli cell apoptosis with the possible involvement of FasL-dependent germ cell apoptosis.

Role of hepatocyte-specific FOXO1 in hepatic glucolipid metabolic disorders induced by perfluorooctane sulfonate

Perfluorooctane sulfonate (PFOS), a prevalent perfluoroalkyl substance (PFAS), is widely present in various environmental media, animals, and even human bodies. It primarily accumulates in the liver, contributing to the disruption of hepatic metabolic homeostasis. However, the precise mechanism underlying PFOS-induced hepatic glucolipid metabolic disorders remains elusive. The transcription factor forkhead box protein O 1 (FOXO1) plays a crucial role in regulating hepatic glucolipid metabolism; however, its involvement in PFOS-induced hepatic glucolipid metabolic disorders has not been thoroughly explored. Molecular docking revealed high binding affinity between PFOS and FOXO1. Male C57BL/6 mice were exposed to PFOS at doses of 0.3, 1.0, and 3.0 mg/kg body weight for 12 weeks to assess its subchronic effects on hepatic glucolipid metabolism in this work. The results indicate that PFOS exposure increases hepatic acetylated FOXO1 expression, promotes liver lipid accumulation, suppresses gluconeogenesis, whereas fasting blood glucose levels remain unaffected but this dysregulation results in insulin resistance. Furthermore, hepatic deletion of FOXO1 in PFOS-exposed mice ameliorates liver injury and reduces lipid accumulation by suppressing hepatic autophagy without significantly affecting gluconeogenesis. In conclusion, FOXO1 may play a pivotal role in the development of PFOS-induced hepatic glucolipid metabolic disorder.

Single-cell transcriptomics reveal the microenvironment landscape of perfluorooctane sulfonate-induced liver injury in female mice

Epidemic and animal studies have reported that perfluoroalkyl and polyfluoroalkyl substances (PFASs) are strongly associated with liver injury; however, to date, the effects of PFASs on the hepatic microenvironment remain largely unknown. In this study, we established perfluorooctane sulfonic acid (PFOS)-induced liver injury models by providing male and female C57BL/6 mice with water containing PFOS at varying doses for 4 weeks. Hematoxylin and eosin staining revealed that PFOS induced liver injury in both sexes. Elevated levels of serum aminotransferases including those of alanine aminotransferase and aspartate transaminase were detected in the serum of mice treated with PFOS. Female mice exhibited more severe liver injury than male mice. We collected the livers from female mice and performed single-cell RNA sequencing. In total, 36,529 cells were included and grouped into 10 major cell types: B cells, granulocytes, T cells, NK cells, monocytes, dendritic cells, macrophages, endothelial cells, fibroblasts, and hepatocytes. Osteoclast differentiation was upregulated and the T cell receptor signaling pathway was significantly downregulated in PFOS-treated livers. Further analyses revealed that among immune cell clusters in PFOS-treated livers, Tcf7+CD4+T cells were predominantly downregulated, whereas conventional dendritic cells and macrophages were upregulated. Among the fibroblast subpopulations, hepatic stellate cells were significantly enriched in PFOS-treated female mice. CellphoneDB analysis suggested that fibroblasts interact closely with endothelial cells. The major ligand-receptor pairs between fibroblasts and endothelial cells in PFOS-treated livers were Dpp4_Cxcl12, Ackr3_Cxcl12, and Flt1_complex_Vegfa. These genes are associated with directing cell migration and angiogenesis. Our study provides a general framework for understanding the microenvironment in the livers of female mice exposed to PFOS at the single-cell level.