👤 Gianfranco Silecchia

Neonicotinoid pesticides, including acetamiprid (ACE), are widely used in agriculture and pose increasing concerns due to their persistence in the environment and potential human exposure mainly through diet. Available evidence suggests that ACE may disrupt adipocyte function and promote metabolic dysfunctions such as obesity; however, there is limited research on how ACE negatively affects adipose tissue (AT) in men and women. This study utilizes an Twenty-four subjects with severe obesity (11 men and 13 women) undergoing bariatric surgery were recruited from St. Andrea University Hospital (Rome, Italy). Visceral adipose tissue biopsies were collected and either treated with ACE or left untreated for further gene and protein expression analysis by RT-qPCR and Western blot, respectively. In addition, adipocytokines secretion, reactive oxygen species production, and free fatty acid release were measured in adipose tissue culture media using commercial or in house assays. Our findings demonstrate that ACE induces distinct sex-dependent alterations in lipid metabolism, Adipokines regulation, and inflammatory pathways. Specifically, it significantly lowers PPARγ gene expression but raises protein levels, particularly in men. Free fatty acid release increases and Hormone Sensitive Lipase (HSL) drops in both sexes, while Lipoprotein Lipase (LPL) decreases only in women. ACE also promotes inflammation mainly in women, increasing TNF-α, NF-κB, and reactive oxygen species. These results show that the neonicotinoid ACE worsens AT dysfunction via inflammatory and metabolic pathways in a sex-specific way, likely leading to different risks of obesity-related complications. Overall, these findings provide a mechanistic basis for understanding the toxicological risk of neonicotinoids, highlighting the importance of sex-specific assessment in evaluating metabolic risks of environmental pesticide exposure. Show less

Angiopoietin-like protein 4 (ANGPTL4) regulates lipid partitioning by inhibiting circulating and tissue lipoprotein lipase (LPL); ANGPTL4 loss-of-function variants improve insulin sensitivity and reduce type 2 diabetes (T2D) risk with mechanisms partially unknown. This study was designed to explore metabolic implications of differential ANGPTL4 and LPL expression in human adipose tissue (AT). We recruited eighty-eight obese individuals, with and without abnormal glucose metabolism (AGM), undergoing bariatric surgery; visceral AT (VAT) fragments were obtained intra-operatively and analyzed by immunohistochemistry and mRNA by rt-PCR. Data on hepatic ANGPTL4 mRNA were available for 40 participants. VAT ANGPTL4 expression was higher in AGM individuals than in those with normal glucose tolerance (NGT) and associated with VAT inflammation, insulin resistance, and presence of adipocyte size heterogeneity. Increased ANGPTL4 was associated with AGM with OR = 5.1 (95% C.I.: 1.2-23; Show less

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide and an independent risk factor for cardiovascular mortality. Angiopoietin-like proteins (ANGPTLs) are targets for vitamin D receptor (VDR)-mediated gene transcription and this axis may promote NAFLD. ANGPTL3 is a hepatokine which inhibits lipoprotein lipase and its experimentally induced inactivation reduces hepatosteatosis. Little is known on ANGPTL3 in human NAFLD and no data exist on its relationship with hepatic VDR/VD-related genes. The aim of this research was to investigate hepatic ANGPTLs and VDR/VD-related gene expression in human obesity in relation to NAFLD. We conducted a cross-sectional investigation on forty obese subjects with/without NAFLD. We evaluated hepatic ANGPTL3, ANGPTL4, ANGPTL8, LPL, VDR, CYP27A1 and CYP2R1 mRNA expression in liver biopsies by RT-PCR; VDR expression was further investigated by immunohistochemistry; circulating ANGPTL3 was measured by Milliplex assay. Compared to non-NAFLD, NAFLD individuals had significantly higher hepatic VDR, ANGPTL3 and LPL expression. ANGPTL3 correlated with steatosis grade, LPL, VDR, CYP27A1 and CYP2R1 expression. Plasma ANGPTL3 concentrations were positively associated with clinical/histological markers of NAFLD/NASH and with hepatic ANGPTL3 expression. Greater hepatic VDR expression was the main determinant of hepatic ANGPTL3 after adjusting for multiple confounders. Hepatic ANGPTL3 expression correlates with greater VDR expression, presence and severity of NAFLD and translates in increased circulating ANGPTL3, likely as a result of its modulation by up-regulated hepatic VDR in NAFLD. This study provides novel insights to potential mechanisms underlying ANGPTLs-mediated ectopic fat accumulation and NAFLD development in obesity. Show less