Perfluorobutanesulfonic Acid Disrupts Pancreatic Organogenesis and Regulation of Lipid Metabolism in the Zebrafish, Danio rerio

Abstract

Since phase-out of highly persistent perfluorosulfonates in the U.S. from non-stick and stain-resistant products in the early 2000s, perfluorobutanesulfonic acid (PFBS) has replaced these compounds as a primary surfactant. Measurements of PFBS in environmental and human samples have been rising in recent years, raising concerns about potential negative health effects. We previously found that embryonic exposures to a related compound, perfluorooctanesulfonic acid (PFOS), decreased pancreas length and insulin-producing islet area in zebrafish embryos (Danio rerio). The objective of this study was to compare the effects of PFBS exposures on pancreatic organogenesis with our previous PFOS findings. Dechorionated zebrafish embryos from two different transgenic fish lines (Tg(insulin:GFP), Tg(ptf1a:GFP)) were exposed to 0 (0.01% DMSO), 16, or 32 µM PFBS daily beginning at 1 day post fertilization (dpf) until 4 and 7 dpf when they were examined using fluorescent microscopy for islet area and morphology, and exocrine pancreas length. PFBS-exposed embryos had significantly increased caudal fin deformities, delayed swim bladder inflation, and impaired yolk utilization. Incidence of fish with significantly stunted growth and truncated exocrine pancreas length was significantly increased, although these two effects occurred independently. Islet morphology revealed an increased incidence of severely hypomorphic islets (areas lower than the 1st percentile of controls) and an elevated occurrence of fragmented islets. RNA Seq data (4 dpf) also identify disruptions in regulation of lipid homeostasis. Overall, this work demonstrates that PFBS exposure can perturb embryonic development, energy homeostasis, and pancreatic organogenesis.

Chemical Characterization of a Legacy Aqueous Film-Forming Foam Sample and Developmental Toxicity in Zebrafish ( Danio rerio )

“… Note: All AFFF data and PFOS liver data are from the present study. PFOS pancreatic data are summarized from Sant et al 2017 , 2019 . —, no effect; AFFF, aqueous film-forming foam; NT, not tested; PFOS, perfluorooctanesulfonic acid.…”

“…Stunted and severely stunted pancreatic phenotypes were determined using the thresholds of 10th and 1st percentiles of control pancreas lengths, respectively, as defined in Sant et al. ( 2019 ). The area of the primary endocrine pancreatic beta cell islets was measured, and qualitative assessment of islet structure was completed to stratify normal, tight structure from fragmented islets.…”

“…Similarly, exocrine pancreas anterior caudal length, which was measured from the depressed fluorescence of the endocrine beta cell islet to the pancreas tail, was normalized to individual body length. Stunted and severely stunted pancreatic phenotypes were determined using the thresholds of 10th and 1st percentiles of control pancreas lengths, respectively, as defined in Sant et al (2019). The area of the primary endocrine pancreatic beta cell islets was measured, and qualitative assessment of islet structure was completed to stratify normal, tight structure from fragmented islets.…”

Associations between Exposures to Perfluoroalkyl Substances and Diabetes, Hyperglycemia, or Insulin Resistance: A Scoping Review

“…A plethora of studies have shown the liver to be the primary target organ of PFAS toxicity, though other tissues such as the kidneys and reproductive tract also have pathological consequences of exposures (reviewed in [ 25 ]). In animals, exposures to PFAS have also been associated with adverse birth outcomes, including teratogenesis and spontaneous abortion [ 26 , 27 ]. PFOA and PFOS have been associated with several types of cancers, including those of the kidney and reproductive organs, and PFOA is now classified as ‘possibly carcinogenic to humans’ (Class 2B) by the International Agency for Research on Cancer (IARC) [ 28 ].…”

“…Following 7-day exposures in mice, scientists also observed increased oxidative stress and inflammation in islets, further supporting PFOS-induced insulitis [ 44 ]. Developmentally, PFOS and perfluorobutanesulfonic acid (PFBS) exposures reduced β-cell area in early pancreatic islets, decreased overall pancreatic size, and decreased insulin gene expression in zebrafish [ 27 , 45 ]. However, these same exposures also led to expanded β-cell area later and increased adiposity in fish later in the lifecourse [ 46 ].…”