👤 Andrea Lenzi

Resource acquisition and allocation impacts individual fitness. Using pellet analysis of breeding adults and stable isotopes of carbon and nitrogen of down feathers of Kelp Gull (Larus dominicanus) nestlings, we evaluated the relationship between urban refuse (beef and chicken) and natural food (fish) consumption of individual females during the pre-incubation period, with fecundity and young nesting's success in the Río de la Plata Estuary in Uruguay. Assimilated urban refuse positively correlated with egg weight and negatively with young nestling's success. This suggests a possible impact of urban refuse foraged by females during the pre-incubation period on their immediate fecundity (positively) and young nestling's survival (negatively). Differences between studies at the individual and colony levels are also discussed in light of an "ecological fallacy" of interpretation and we thus argue for the need of additional research to evaluate this relationship further, considering potential confounding factors. 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

ANGPTL4 inhibits lipoprotein lipase in adipose tissue, regulating plasma triglycerides levels. In persons with obesity plasma ANGPTL4 levels have been positively correlated with body fat mass, TG levels and low HDL. A loss-of-function E40K mutation in Participants with obesity carrying the E40K variant had significantly lower TG ( In participants with obesity the Show less

Apolipoprotein A-V (ApoA-V) is a recognized regulator of plasma triglycerides (TGs), and previous studies have shown associations between variants in APOA5 (apolipoprotein-A5) gene and high TG levels. Recently, a new association between the Arg282Ser missense mutation (rs778114184 G > T) in APOA5 gene and decreased triglyceride levels has been shown in an adult population from Sardinia. In this study we add further insight into the role of APOA5 by exploring whether this association begins early in life in children, or becomes manifest only in adulthood. We performed the genetic association analysis of APOA5 in a cohort of 925 overweight and obese children and adolescents from Sardinia, Italy, to see if the genetic burden is already at play before modifying risk factors are interacting. We identified 24 heterozygous subjects for the Arg282Ser variant and no homozygous subject. Here we show that the Arg282Ser mutation in APOA5 gene is associated with a significant reduction of TG (-15.5 mg/dl), total (-18.1 mg/dl) and LDL-cholesterol (-14.8 mg/dl) levels in overweight/obese children and adolescents, indicating that indeed this association appears early in life. Also, we observed a significant reduction in serum apoA-V levels in heterozygous children. Our data clearly show that the Arg282Ser mutation in APOA5 gene determines a reduction of TG, total and LDL-cholesterol and apolipoprotein A-V levels in overweight/obese children and adolescents, demonstrating that this mutation has the power to affect lipid levels already since childhood. Show less