Pyriproxyfen and diflubenzuron pesticides impair human adipose stem cell function: evidence of redox imbalance, KDM6B upregulation, and dysregulated adipogenesis

Introduction
Pyriproxyfen (PPF) and diflubenzuron (DFB) are widely used pesticides with metabolic toxicity in humans underexplored. White adipose tissue (WAT) is a potential target for endocrine-disrupting chemicals.
Aim
We investigated the effects of PPF and DFB on human adipose-derived stem cells (hASCs) redox balance, epigenetic regulation, and adipogenic differentiation.
Method
Visceral WAT hASCs were exposed to PPF or DFB (0.01–2 mg/L). Cytotoxicity was observed at ≥1.5 mg/L, with 1 mg/L selected for further experiments.
Results
8-day exposure to PPF or DFB reduced catalase and superoxide dismutase activities while increasing glutathione peroxidase. This was accompanied by 74% increase in mRNA expression of H3K27 demethylase KDM6B and elevated secretion of CCL2 in PPF-exposed cells. During adipogenic differentiation, PPF and DFB upregulated early transcription factors and enhanced lipid accumulation. Differentiated adipocytes exhibited higher proportion of saturated fatty acids and increased leptin secretion, while adiponectin levels remained unchanged. In mature primary adipocytes, PPF suppressed the secretion of leptin and adiponectin, and significantly increased basal lipolysis.
Discussion
our results show endocrine and metabolic disruption induced by non-cytotoxic concentrations of PPF and DFB. PPF upregulated the epigenetic modulator KDM6B and promoted dysregulated adipogenic programming in hASCs, favouring lipid accumulation and a pro-inflammatory, metabolically compromised phenotype.