Acute PFOS exposure consistently dysregulates glucose-stimulated insulin secretion across model systems

Palaniyandi, J.; Hoyeck, M. P.; van Zyl, E.; Basu, L.; Ching, M. E. A.; Ameyaa-Sakyi, A.; Blais, A.; Tayabali, A.; Rand, A. A.; Bruin, J. E.

doi:10.1101/2025.10.23.684149

bioRxiv · 10.1101/2025.10.23.684149

Acute PFOS exposure consistently dysregulates glucose-stimulated insulin secretion across model systems

Palaniyandi, J.·Hoyeck, M. P.·van Zyl, E.·Basu, L.·Ching, M. E. A.·Ameyaa-Sakyi, A.·Blais, A.·Tayabali, A.·Rand, A. A.·Bruin, J. E.

View original source ↗Export metadata ↓

Abstract

Aims/hypothesisPoly- and perfluoroalkyl substances (PFAS) are fluorinated chemicals widely used in consumer and industrial products. Serum PFAS concentrations have been linked to increased type 2 diabetes risk, but whether this is caused by direct effects of PFAS on the endocrine pancreas remains unclear. This study expands on previous biodistribution data to better characterize PFAS accumulation in human pancreas. We also assessed the effects of perfluorooctane sulfonic acid (PFOS) on pancreatic beta cell function using various model systems. MethodsWe measured concentrations of three legacy PFAS (PFOS, PFOA, PFHxS) in plasma and pancreas from 88 human donors. We also modeled PFOS and PFOA exposure in mice to confirm our human biodistribution data. We next exposed immortalized INS-1 cells, primary human donor islets, and primary mouse islets to DMSO (vehicle) or PFOS (1, 10 or 100 M) either acutely during a glucose-stimulated insulin secretion (GSIS) assay or for 48h (prolonged) and GSIS was subsequently measured. We also assessed whether the acute effects of PFOS on GSIS in mouse islets were mediated by G-protein coupled receptor-40 (GPR40) and/or glucagon-like peptide-1 receptor (GLP-1R). Lastly, we exposed female mice to DMSO or 10 mg/kg PFOS with or without a 2 g/kg glucose bolus to assess the acute effects of PFOS on glucose homeostasis in vivo. ResultsPFOS was detected at higher concentrations in both plasma and pancreas compared to PFOA and PFHxS in our human donor population. Similarly, PFOS accumulated in pancreas at concentrations 2x higher than PFOA in our mouse model. We provide compelling evidence that PFOS exposure dysregulates insulin secretion in various model systems. Prolonged PFOS exposure suppressed GSIS in INS-1 832/3 cells and mouse islets, whereas acute PFOS exposure stimulated GSIS in mouse islets and in a subset of our human donor islets. We also show that the acute effects of PFOS on GSIS in mouse islets were partly mediated by GLP-1R. Importantly, acute PFOS exposure increased plasma insulin levels in female mice in vivo, but only when PFOS exposure was concurrent with a glucose bolus. ConclusionsLegacy PFAS chemicals are consistently detected in human pancreas tissue. We clearly show that PFOS exposure dysregulates insulin secretion in various model systems, although effects varied based on the model and duration of exposure. Collectively, our findings support emerging evidence that PFOS contribute to beta cell dysfunction and points to the importance of model selection when assessing toxicological effects of PFAS on islet function.

Explore related subjects

molecular biology Preprint

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Palaniyandi, J., Hoyeck, M. P., van Zyl, E., Basu, L., Ching, M. E. A., Ameyaa-Sakyi, A., Blais, A., Tayabali, A., Rand, A. A., Bruin, J. E.. 2025-10-27. Acute PFOS exposure consistently dysregulates glucose-stimulated insulin secretion across model systems. https://doi.org/10.1101/2025.10.23.684149

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Hidden Biodiversity in Wildlife Trade Networks: DNA Barcoding Reveals Fish and Crocodilian Species in Commercialized Swim Bladders

International wildlife trade represents one of the major drivers of biodiversity exploitation worldwide. However, the true taxonomic diversity embedded within commercial wildlife products often remains unknown because processing removes diagnostic morphological characteristics, preventing reliable species identification. Consequently, biodiversity assessments based solely on product labels may substantially underestimate the diversity of species involved in trade networks. To investigate hidden biodiversity within wildlife trade products, we applied DNA barcoding based on the mitochondrial cytochrome c oxidase subunit I (COI) gene to 77 products commercialized as fish swim bladders and seized at Guarulhos International Airport, Brazil. Molecular analyses successfully identified all samples and revealed the presence of four species: Plagioscion auratus (n = 38), Cynoscion acoupa (n = 7), Melanosuchus niger (n = 17), and Caiman crocodilus (n = 15). Fish species accounted for 71.4% of all samples, whereas crocodilians represented 28.6%, demonstrating that products marketed under a single commercial category may conceal substantial taxonomic diversity. Notably, the occurrence of two Amazonian crocodilian species within a trade chain traditionally associated with fish products reveals a previously undocumented component of the international wildlife trade. Our findings demonstrate that DNA barcoding is an effective tool for uncovering hidden biodiversity within processed wildlife products and provide evidence that wildlife trade networks may involve a broader spectrum of species than suggested by commercial labels. These results highlight the importance of molecular surveillance for biodiversity monitoring, wildlife trade regulation, and conservation planning.

molecular biology↗

bioRxiv2026

Plasmid architecture determines the stability of inverted terminal repeats in adeno-associated virus vectors

Recombinant vectors derived from adeno-associated viruses (rAAVs) are a mainstay of human gene therapy. rAAVs are produced from plasmids containing transgene cassettes flanked by inverted terminal repeats (ITRs), which form structured DNA elements that stabilize the ends of the single-stranded viral genome and are the only viral sequences required in cis for genome packaging. For decades, it has been recognized that propagation of ITR-containing plasmids can result in deletions and other mutations, prompting the use of specialized bacterial strains, modified growth conditions, and truncated or altered ITRs. Despite these practices, ITR instability remains a persistent source of plasmid heterogeneity. To identify determinants of ITR stability, we evaluated ITR integrity in one of the original cloned AAV2 genome isolates, a reconstructed AAV2 plasmid, and a synthetic rAAV vector containing full-length native AAV2 ITRs. We established a quantitative bioinformatic workflow for analyzing ITR-containing plasmids and virus preparations from raw Oxford Nanopore sequencing data. These experiments showed that ITRs were highly stable during short-term culture, whereas prolonged culture revealed strong positional effects, with preferential loss or mutation of the ITR nearest the plasmid origin of replication. Consistent with this model, a survey of 7,041 sequence-verifiable AAV plasmids from the Addgene repository identified a widely disseminated 11-bp ITR deletion in 4,773 plasmids; among analyzable two-ITR plasmids, this deletion was located in the origin-proximal ITR in 95.3% of cases. Guided by these findings, we constructed a novel rAAV entry vector with stable full-length native AAV2 ITRs that enabled efficient packaging of a 4,750-bp all-in-one CRISPR-Cas9 cassette. Finally, we developed a cell-based strategy to compare the effects of ITR mutations on rAAV genome integration, providing preliminary evidence that ITR sequence variation can influence integration outcomes. Together, these findings show that ITR instability is a preventable, position-dependent property of plasmid architecture and identify ITR integrity as an important variable in rAAV vector design and quality control.

molecular biology↗

bioRxiv2026

Single-point mutation alters odorant receptor sensitivity associated with host plant specialization in Spodoptera moths

Host specialization in herbivorous insects is often associated with divergence in chemosensory abilities. Here, we investigated the possible contribution of odorant receptors (ORs) in host plant restriction in the lily moth Spodoptera picta, a species specialized on Amaryllidaceae. Manual annotation of S. picta ORs in its genome revealed a repertoire similar in size and composition to those of its polyphagous sister species, S. littoralis and S. litura, suggesting that specialization did not involve major gene loss or expansion in the lily moth. To assess functional divergence beyond gene number, we applied a large scaled structure-based virtual screening approach to the entire OR repertoires of these three Spodoptera species, generating ligand-binding profiles for 120,591 volatile compounds. Among 69 1:1:1 OR orthologs, 24 exhibited divergent predicted binding spectra. We pinpointed OR29 that we also found to be highly expressed in both male and female antennae of S. picta through a RNAseq approach. Functional assays demonstrated that S. picta OR29 acquired heightened sensitivity to limonene enantiomers, volatiles emitted by host Amaryllidaceae inflorescences. Site-directed mutagenesis revealed that a single amino acid substitution within the predicted binding region underlies this shift in sensitivity. These results show that host specialization in S. picta has not been accompanied by significant OR repertoire remodeling, but rather by subtle molecular changes that fine-tune receptor sensitivity to host-derived volatiles.

molecular biology↗