Background: Chronic low-grade inflammation in obesity is linked to white adipose tissue (WAT) dysfunction. Plasma lipopolysaccharide (LPS) activates Toll-like receptor 4 (TLR4), triggering NF-κB and worsening these disturbances. Previously, we showed that histone H3 lysine 27 (H3K27) epigenetic modifications affect WAT gene expression in high-fat-diet mice, identifying key pathways in adipose-derived stem cells (ASCs). This study explores whether NF-κB influences H3K27 modifiers in human ASCs and evaluates fish oil (FO) as a modulator. Methods: Human visceral WAT ASCs were stimulated with LPS and treated with FO enriched with eicosapentaenoic acid (EPA). Flow cytometry, PCR array, RT-PCR, and Western blot assays were used. Results: LPS increased NF-κB activity, elevating KDM6B demethylase levels and H3K27 acetylation. These epigenetic modifications in LPS-stimulated ASCs were associated with persistent changes in the expression of genes involved in adipogenesis, metabolic regulation, and inflammation, even after LPS removal and cell differentiation. FO mitigated these effects, reducing H3K27 acetylation and promoting methylation. Conclusions: FO demonstrates potential in modulating inflammation-induced epigenetic changes and preserving adipocyte function.

Background: Chronic low-grade inflammation in obesity is linked to white adipose tissue (WAT) dysfunction. Plasma lipopolysaccharide (LPS) activates Toll-like receptor 4 (TLR4), triggering NF-κB and worsening these disturbances. Previously, we showed that H3K27 epigenetic modifications affect WAT gene expression in high-fat diet mice, identifying key pathways in adipose-derived stem cells (ASCs). This study explores whether NF-κB influences H3K27 modifiers in human ASCs and evaluates fish oil (FO) as a modulator. Methods: Human visceral WAT ASCs were stimulated with LPS and treated with FO enriched with eicosapentaenoic acid (EPA). Flow cytometry, PCR array, RT-PCR, and Western blot assays were used. Results: LPS increased NF-κB activity, elevating KDM6B demethylase levels and H3K27 acetylation. These epigenetic modifications in LPS-stimulated ASCs were associated with persistent changes in the expression of genes involved in adipogenesis, metabolic regulation, and inflammation, even after LPS removal and cell differentiation. FO mitigated these effects, reducing H3K27 acetylation and promoting methylation. Conclusions: FO demonstrates potential in modulating inflammation-induced epigenetic changes and preserving adipocyte function.

Environmental exposure to heavy metals, particularly cadmium (Cd), has been increasingly associated with obesity, metabolic dysfunction, chronic inflammation, and related disorders such as type 2 diabetes and cardiovascular diseases. Adipose tissue (AT), a paracrine and endocrine organ central to systemic energy and inflammatory homeostasis, is a major site of heavy metal accumulation and a key target of Cd toxicity. However, the mechanisms by which Cd disrupts adipocyte function, especially through epigenetic pathways, remain poorly understood. In this study, we investigated the effects of Cd on epigenetic regulators, antioxidant enzyme activity, inflammatory mediators, and adipogenic programming in human adipose-derived stromal/stem cells (hASCs) and differentiated adipocytes. Cd exposure altered histone modifiers associated with lysine 27 of histone 3 (H3K27), disrupted redox balance in a concentration-dependent manner, impaired adipogenic differentiation and lipid accumulation, and modulated inflammatory and adipokine responses according to differentiation stage and Cd concentration. Our findings suggest that Cd compromises adipose cell homeostasis through mechanisms involving epigenetic dysregulation, oxidative stress imbalance, and altered adipogenic and inflammatory signalling. These observations point to possible long-term metabolic consequences of environmental Cd exposure due to its accumulation in adipose tissue.

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. We investigated the effects of PPF and DFB on human adipose-derived stem cells (hASCs) redox balance, epigenetic regulation, and adipogenic differentiation. 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. 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. 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.