Project description:Per- and polyfluoroalkyl substances (PFAS) are environmental contaminants of concern due to their persistence and potential adverse health effects. Epidemiological studies have linked PFAS with an increased risk of uterine diseases including fibroids however, the mechanisms involved remain to be elucidated. This study investigated the effects of individual PFAS, including long-chain “legacy” PFAS [perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS)] and short-chain “alternative” PFAS compounds [undecafluoro-2-methyl-3-oxahexanoic acid (GENX/HFPO-DA), perfluorobutanesulfonic acid (PFBS)], as well as a mixture of these chemicals on the function and transcriptome of an immortalized human myometrial cell line (UT-TERT). UT-TERT cells exposed to individual PFAS displayed increased cell viability and proliferation. Flow cytometry analysis revealed that PFOS and the PFAS mixture altered cell cycle progression. Migration assays demonstrated that PFOS and the PFAS mixture significantly enhanced UT-TERT cell migration. Gap junction intercellular communication (GJIC) was impaired following PFOA, PFBS, and PFAS mixture exposure, indicating potential disruptions in cell-to-cell communication within the uterine environment. Transcriptomic analysis using RNA-seq identified substantial changes in gene expression after exposure to environmentally relevant levels of individual PFAS and PFAS mixture. Pathway analysis revealed common molecular pathways associated with PFAS exposure, including Cell-to-Cell Signaling, Lipid Metabolism, and Cell Death and Survival, while other pathways were unique to specific PFAS. These findings highlight the multifaceted effects of PFAS on myometrial cells, providing insights into the potential mechanisms underlying PFAS-associated health risks. Further research is necessary to elucidate the long-term implications of PFAS exposure on uterine function and overall reproductive health.
Project description:Class-switching to IgG2a/c in mice is a hallmark response to intracellular pathogens. T cells can promote class-switching and the predominant pathway for induction of IgG2a/c antibody responses has been suggested to be via stimulation from Th1 cells. We previously formulated CAF®01 (cationic liposomes containing dimethyldioctadecylammonium bromide (DDA) and Trehalose-6,6-dibehenate (TDB)) with the lipidated TLR7/8 agonist 3M-052 (DDA/TDB/3M-052), which promoted robust Th1 immunity in newborn mice. When testing this adjuvant in adult mice using the recombinant Chlamydia trachomatis (C.t.) vaccine antigen CTH522, it similarly enhanced IgG2a/c responses compared to DDA/TDB, but surprisingly reduced the magnitude of the IFN-g+ Th1 response in a TLR7 agonist dose-dependent manner. Single cell RNA-sequencing revealed that DDA/TDB/3M-052 liposomes initiated early transcription of class-switch regulating genes directly in pre-germinal center B cells. Mixed bone marrow chimeras further demonstrated that this adjuvant did not require Th1 cells for IgG2a/c switching, but rather facilitated TLR7-dependent T-bet programming directly in B cells. This study underlines that adjuvant-directed IgG2a/c class-switching in vivo can occur in the absence of T cell help, via direct activation of TLR7 on B cells and positions DDA/TDB/3M-052 as a powerful adjuvant capable of eliciting type I-like immunity in B cells without strong induction of Th1 responses.
Project description:The placenta is crucial for fetal development, is affected by PFAS toxicity, and evidence is accumulating that gestational PFAS perturb the epigenetic activity of the placenta. Gestational PFAS exposure can adversely affect offspring, yet individual and cumulative impacts of PFAS on the placental epigenome remain underexplored. Here, we conducted an epigenome-wide association study (EWAS) to examine the relationships between placental PFAS levels and DNA methylation in a cohort of mother-infant dyads in Arkansas (N = 151). We measured 17 PFAS in human placental tissues and quantified placental DNA methylation levels via the Illumina EPIC Microarray. We tested for differential DNA methylation with individual PFAS, and with mixtures of multiple PFAS. Our results demonstrated that numerous epigenetic loci were perturbed by PFAS, with PFHxS exhibiting the most abundant effects. Mixture analyses suggested cumulative effects of PFOA and PFOS, while PFHxS may act more independently. We additionally explored whether sex-specific effects may be present and concluded that future large studies should explicitly test for sex-specific effects. The genes that are annotated to our PFAS-associated epigenetic loci are primarily involved in growth processes and cardiometabolic health, while some genes are involved in neurodevelopment. These findings shed light on how prenatal PFAS exposures affect birth outcomes and children's health, emphasizing the importance of understanding PFAS mechanisms in the in-utero environment.
Project description:Per- and polyfluoroalkyl substances (PFAS) are a very large (thousands of chemicals) category; these substances have important industrial and consumer product applications. PFAS are highly persistent in the environment, and some are known to pose human health hazard. Regulatory agencies worldwide are considering restrictions and outright bans of PFAS; however, little data exists to make informed decisions. Therefore, a prioritization strategy is urgently needed for evaluation of potential hazards of PFAS. Structure-based grouping could expedite selection of PFAS for testing; still, the hypothesis that structure-effect relationships exist requires confirmation. We tested 26 structurally diverse PFAS from 8 groups in two human cell types from organs that are thought to be targets for PFAS. We used human induced pluripotent stem cell-derived hepatocytes and cardiomyocytes and tested concentration-response effects on both cell function and gene expression. Few phenotypic effects were observed in hepatocytes, but negative chronotropy was observed for 8 of 26 PFAS. Substance- and cell-dependent transcriptomic changes were more pronounced; however, little evidence of group-specific effects was observed. In hepatocytes, we found up-regulation of stress-related and extracellular matrix organization pathways, and down-regulation of fat metabolism. In cardiomyocytes, contractility-related pathways were most affected. Using these data, we derived phenotypic and transcriptomic point of departure estimates and compared them to predicted PFAS exposures. The conservative estimates for bioactivity and exposure were used to derive margin-of-exposure (MOE) for each PFAS. We found that most (23 of 26) PFAS had MOE>1. Overall, our data suggests that chemical structure-based grouping of PFAS may not be an appropriate strategy to predict their biological effects. This means that testing of the individual PFAS would be needed for confident decision-making. Our proposed strategy of using two human cell types and considering both phenotypic and transcriptomic effects, combined with dose-response analysis, may be used for prioritization of PFAS.
Project description:Per- and polyfluoroalkyl substances (PFAS) are a very large (thousands of chemicals) category; these substances have important industrial and consumer product applications. PFAS are highly persistent in the environment, and some are known to pose human health hazard. Regulatory agencies worldwide are considering restrictions and outright bans of PFAS; however, little data exists to make informed decisions. Therefore, a prioritization strategy is urgently needed for evaluation of potential hazards of PFAS. Structure-based grouping could expedite selection of PFAS for testing; still, the hypothesis that structure-effect relationships exist requires confirmation. We tested 26 structurally diverse PFAS from 8 groups in two human cell types from organs that are thought to be targets for PFAS. We used human induced pluripotent stem cell-derived hepatocytes and cardiomyocytes and tested concentration-response effects on both cell function and gene expression. Few phenotypic effects were observed in hepatocytes, but negative chronotropy was observed for 8 of 26 PFAS. Substance- and cell-dependent transcriptomic changes were more pronounced; however, little evidence of group-specific effects was observed. In hepatocytes, we found up-regulation of stress-related and extracellular matrix organization pathways, and down-regulation of fat metabolism. In cardiomyocytes, contractility-related pathways were most affected. Using these data, we derived phenotypic and transcriptomic point of departure estimates and compared them to predicted PFAS exposures. The conservative estimates for bioactivity and exposure were used to derive margin-of-exposure (MOE) for each PFAS. We found that most (23 of 26) PFAS had MOE>1. Overall, our data suggests that chemical structure-based grouping of PFAS may not be an appropriate strategy to predict their biological effects. This means that testing of the individual PFAS would be needed for confident decision-making. Our proposed strategy of using two human cell types and considering both phenotypic and transcriptomic effects, combined with dose-response analysis, may be used for prioritization of PFAS.
Project description:The use of aqueous film-forming foams (AFFF) at fire-training areas (FTAs) has introduced into ground- and surface waters a complex mixture of per- and poly-fluorinated alkyl substances (PFAS). The toxicity of environmental PFAS mixtures to wildlife is not well understood and presents a knowledge gap that limits accurate risk assessment. To evaluate reproductive biomarker responses to complex environmental PFAS mixtures, we conducted a series of on-site experiments using flow-through mobile laboratories exposing fish to groundwater impacted by a legacy FTA and an adjacent reference site A 60K fathead minnow microarray was used to quantify gene expression patterns in the testis and liver of fish exposed to water from Fire Training Area 1 and 2 relative to a reference site.
Project description:The use of aqueous film-forming foams (AFFF) at fire-training areas (FTAs) has introduced into ground- and surface waters a complex mixture of per- and poly-fluorinated alkyl substances (PFAS). The toxicity of environmental PFAS mixtures to wildlife is not well understood and presents a knowledge gap that limits accurate risk assessment. To evaluate reproductive biomarker responses to complex environmental PFAS mixtures, we conducted a series of on-site experiments using flow-through mobile laboratories exposing fish to groundwater impacted by a legacy FTA and an adjacent reference site A 60K fathead minnow microarray was used to quantify gene expression patterns in the testis and liver of fish exposed to water from Fire Training Area 1 and 2 relative to a reference site.
Project description:We introduce FluoroMatch, which automates file conversion, chromatographic peak picking, blank feature filtering, PFAS annotation based on precursor and fragment masses, and annotation ranking. The software library currently contains about 7000 PFAS fragmentation patterns based on rules derived from standards and literature, and the software automates a process for users to add additional compounds. The use of intelligent data-acquisition methods (iterative exclusion) nearly doubled the number of annotations. The software application is demonstrated by characterizing PFAS in landfill leachate as well as in leachate foam generated to concentrate the compounds for remediation purposes. FluoroMatch had wide coverage, returning 27 PFAS annotations for landfill leachate samples, explaining 71% of the all-ion fragmentation (CF2)n related fragments. By improving the throughput and coverage of PFAS annotation, FluoroMatch will accelerate the discovery of PFAS posing significant human risk.