Per- and polyfluoroalkyl substances (PFAS) toxicity and mitigation of adipogenic dysregulation in 3T3-L1 preadipocytes.

Obesity and metabolic disorders are rising global concerns, with one factor linked to per- and polyfluoroalkyl substances (PFAS), a class of persistent endocrine-disrupting chemicals that affect adipogenic pathways. While PFAS are known to promote terminal lipid accumulation in mature adipocytes, their effects during dynamic adipocyte differentiation, particularly at human-relevant doses and in mixtures, remain poorly understood. This study employed 3T3-L1 preadipocytes to assess PFAS toxicity and mitigation in cell viability, redox balance, mitochondrial integrity, lipid content, and gene expression during differentiation. Repeated, low-dose exposure to 0.1 μM PFAS (individual and mixture) time-dependently reduced cell viability through induced reactive oxygen and nitrogen species by 22-49 % and reduced mitochondrial membrane potential. The 2-4-fold increase in lipid accumulation, especially by PFOA, correlated with Pparγ activation by 47-86 % (r(2) ≥ 0.98). PFAS also triggered pro-inflammatory cytokines (Tnfα, Il-6) and suppressed anti-inflammatory mediators (Tgfβ, Il-10, Il-4), suggesting interactions between adipogenic and inflammatory pathways. Importantly, montmorillonite clays amended with choline or chlorophyll at 0.001 % and 0.01 % dose-dependently mitigated these effects, supporting critical PFAS pathways. By integrating mechanistic toxicology with mitigation interventions, this work establishes PFAS adipogenic toxicity through oxidative, metabolic, and inflammatory pathways, and supports nutrient-amended clays as sorbents to reduce PFAS bioavailability and prevent toxicity pathways during adipocyte development.