Perfluorooctane sulfonate-induced oxidative stress contributes to pancreatic β-cell apoptosis by inhibiting cyclic adenosine monophosphate pathway: Prevention by pentoxifylline

PFOS and PFOSA induce oxidative stress-mediated cardiac defects in zebrafish via PPARγ and AHR pathways, respectively

Perfluorooctane sulfonate (PFOS) and its precursor, perfluorooctane sulfonamide (PFOSA), are widespread in the environment. Evidence suggests a strong link between maternal exposure to PFOS/PFOSA and congenital heart diseases in the offspring, but the underlying mechanisms remain unclear. We hypothesized that PFOS and PFOSA induce cardiac defects through the peroxisome proliferator-activated receptor gamma (PPARγ) and aryl hydrocarbon receptor (AHR) pathways, respectively. In this study, we demonstrated that exposing zebrafish embryos to either PFOSA or PFOS caused cardiac malformations and dysfunction. Both PFOS and PFOSA induced reactive oxygen species (ROS) overproduction, mitochondrial damage, and apoptosis in zebrafish larvae hearts. Blockade of PPARγ through either pharmaceutical inhibition or genetic knockdown only attenuated the changes caused by PFOS, but not those elicited by PFOSA. Conversely, inhibition of AHR alleviated the adverse effects induced by PFOSA but not by PFOS. Both PFOSA and PFOS exhibited similar binding affinities to AHR using molecular docking techniques. The varying ability of PFOS and PFOSA to induce AHR activity in zebrafish embryonic hearts can be attributed to their different capabilities for activating PPARγ. In summary, our findings indicate that PFOS and PFOSA induce excessive ROS production in zebrafish larvae via the PPARγ and AHR pathways, respectively. This oxidative stress in turn causes mitochondrial damage and apoptosis, leading to cardiac defects.

Association between mixed exposure to per- and polyfluoroalkyl substances and metabolic syndrome in Korean adults: Data from the Korean National environmental health survey cycle 4

AIM

To explore the effect of mixed exposure to per- and polyfluoroalkyl substances (PFAS) on metabolic syndrome (MetS).

METHODS

This cross-sectional study used data from the Korean National Environmental Health Survey Cycle 4 (2018-2020). The serum concentrations of five PFAS (perfluorooctanoic acid [PFOA], perfluorooctanesulfonic acid [PFOS], perfluorohexanesulfonic acid, perfluorononanoic acid [PFNA], and perfluorodecanoic acid [PFDeA]) were measured, and the relative potency factor approach was employed for the mixture of PFAS (Cmix) assessment. MetS was diagnosed if the patient satisfied three of five criteria: central obesity, elevated triglycerides, reduced high-density lipoprotein cholesterol, elevated blood pressure (BP), and elevated glycated hemoglobin (HbA1c). Age, sex, smoking, drinking, and exercise status were considered as covariates. The risk of MetS for single and mixed exposure to PFAS was analyzed using binomial regression and Bayesian kernel machine regression (BKMR).

RESULTS

A total of 2984 (male:female = 1:1.3; age range, 19-80 years) adults were enrolled. The prevalence of MetS was 45.6%. Each PFAS and Cmix levels were higher in participants with MetS than in those without MetS. Cmix increased the risk of elevated BP and HbA1c, and eventually MetS (odds ratio [OR] = 2.00, 95% confidence interval [CI] 1.11-3.60 per log10Cmix; OR = 1.57, 95% CI 1.07-2.31 in the highest quartile of Cmix [Q4] vs. the lowest [Q1]). Sex-specific analyses revealed that the impact of Cmix was valid in females but not in males (Cmix Q4 vs. Q1: OR = 1.01, 95% CI 0.57-1.8 in males; OR = 2.30, 95% CI 1.38-3.84 in females). In the BKMR analysis, mixed exposure to PFAS dose-dependently increased the risk of MetS, particularly in females. Among single exposures, PFNA contributed significantly to the cumulative effect.

CONCLUSION

Mixed exposure to PFAS was associated with a higher risk of MetS in females. Further studies on potential health concerns associated with PFAS mixtures are warranted.

The effect of per and polyfluoroalkyl substance (PFAS) exposure on gestational diabetes mellitus and its subclinical risk factors: A systematic review and meta-analysis protocol

BACKGROUND

Multiple lines of evidence suggest that exposure to per- and polyfluoroalkyl substances (PFAS) may alter glucose homeostasis, particularly during pregnancy, and may affect risk for developing gestational diabetes mellitus (GDM). While previous systematic reviews have been conducted on this topic, they did not assess internal validity of the included studies and their search strategies were narrowly focused.

OBJECTIVE

The objective of this study is to assess the effect of higher PFAS exposure (defined by individual compounds or mixtures measured before or during pregnancy) on GDM and subclinical measures of impaired glucose homeostasis (measured during pregnancy) compared to lower PFAS exposure in pregnant.

METHODS

We developed our systematic review protocol in accordance with the Navigation Guide. Peer-reviewed journal and grey literature searches were piloted in to identify relevant studies and refine our search terms and strategy. We also piloted the study screening criteria and data extraction form in DistillerSR, and refined our protocol accordingly. The risk of bias assessment protocol was adapted from Navigation Guide guidance and will be piloted and performed in DistillerSR. Pending the identification of comparable studies, quantitative meta-analyses will be performed where possible. Study results that cannot be quantitatively synthesized will be included in a narrative synthesis. The quality and strength of the body of evidence will be evaluated using Navigation Guide methodology, which is informed by guidance from the Cochrane Collaboration and Grading of Recommendations Assessment, Development and Evaluation (GRADE). We also made refinements to the quality of evidence considerations based on guidance from the National Institute of Environmental Health Sciences (NIEHS) Office of Health Assessment and Translation (OHAT).

FUNDING

This work was supported by the Systematizing Data on Per- and Polyfluoroalkyl Substances and Health Northeastern University TIER 1 Award.

Sub-acute exposure of male guppies (Poecilia reticulata) to environmentally relevant concentrations of PFOA and GenX induces significant changes in the testis transcriptome and reproductive traits

Poly- and perfluoroalkyl substances (PFAS) are frequently detected in the environment and are linked to adverse reproductive health outcomes in humans. Although legacy PFAS have been phased out due to their toxicity, alternative PFAS are increasingly used despite the fact that information on their toxic effects on reproductive traits is particularly scarce. Here, we exposed male guppies (Poecilia reticulata) for a short period (21 days) to an environmentally realistic concentration (1 ppb) of PFOA, a legacy PFAS, and its replacement compound, GenX, to assess their impact on reproductive traits and gene expression. Exposure to PFAS did not impair survival but instead caused sublethal effects. Overall, PFAS exposure caused changes in male sexual behaviour and had detrimental effects on sperm motility. Sublethal variations were also seen at the transcriptional level, with the modulation of genes involved in immune regulation, spermatogenesis, and oxidative stress. We also observed bioaccumulation of PFAS, which was higher for PFOA than for GenX. Our results offer a comprehensive comparison of these two PFAS and shed light on the toxicity of a newly emerging alternative to legacy PFAS. It is therefore evident that even at low concentrations and with short exposure, PFAS can have subtle yet significant effects on behaviour, fertility, and immunity. These findings underscore the potential ramifications of pollution under natural conditions and their impact on fish populations.

Unlocking β-cell restoration: The crucial role of PDX1 in diabetes therapy

Diabetes has been a significant healthcare problem worldwide for a considerable period. The primary objective of diabetic treatment plans is to control the symptoms associated with the pathology. To effectively combat diabetes, it is crucial to comprehend the disease's etiology, essential factors, and the relevant processes involving β-cells. The development of the pancreas, maturation, and maintenance of β-cells, and their role in regular insulin function are all regulated by PDX1. Therefore, understanding the regulation of PDX1 and its interactions with signaling pathways involved in β-cell differentiation and proliferation are crucial elements of alternative diabetes treatment strategies. The present review aims to explore the protective role of PDX1 in β-cell proliferation through signaling pathways. The main keywords chosen for this review include "PDX1 for β-cell mass," "β-cell proliferation," "β-cell restoration via PDX1," and "mechanism of PDX1 in β-cells." A comprehensive literature search was conducted using various internet search engines, such as PubMed, Science Direct, and other publication databases. We summarize several approaches to generating β-cells from alternative cell sources, employing PDX1 under various modified growth conditions and different transcriptional factors. Our analysis highlights the unique potential of PDX1 as a promising target in molecular and cell-based therapies for diabetes.