Biology subjects

Gastaldelli, A.

Publications and source records attributed to Gastaldelli, A..

3 recordsLinked to original sources

bioRxiv2022

Adipose tissue dysfunction and visceral fat are associated to hepatic insulin resistance and severity of NASH even in lean individuals

Background & AimsNonalcoholic fatty liver disease (NAFLD) is a heterogeneous disorder, but the factors that determine this heterogeneity remain poorly understood. Adipose tissue (AT) dysfunction is causally linked to NAFLD since it causes intrahepatic triglyceride (IHTG) accumulation through increased hepatic lipid flow, due to insulin resistance (IR) and pro-inflammatory adipokines release. While many studies in NAFLD have looked at total adiposity (that is mainly subcutaneous fat, SC-AT), it is still unclear the impact of visceral fat (VF). Thus, we investigated how VF vs. SC-AT were related to NAFLD in lean, overweight, and obese individuals compared to lean controls. MethodsThirty-four non-diabetic NAFLD with liver biopsy and eight lean control individuals (CT) were enrolled in this study. We measured fat distribution (VF, SC-AT and IHTG) by magnetic resonance imaging (MRI), adiponectin concentration, free fatty acids (FFAs) and triglyceride (TAG) concentration and composition by mass spectrometry (MS), lipolysis and IR by tracer infusion. ResultsIHTG was positively associated with lipolysis, adipose tissue IR, TG concentrations, and increased ratio of saturated/unsaturated fatty acids. VF was higher in NAFLD (including lean individuals) compared to controls, was increased with fibrosis stage and was associated with IR in liver, muscle and adipose tissue, increased lipolysis, and decreased adiponectin levels. Collectively, our results suggest that VF accumulation, given its location close to the liver, is one of the major risk factors for NAFLD. ConclusionsThese findings propose VF as an early indicator of NAFLD independently of BMI, which may allow for evidence-based prevention and intervention strategies.

physiology↗

bioRxiv2021

Assessment of exposure to Di (2-ethylhexyl) phthalate (DEHP) metabolites and Bisphenol A (BPA) and its importance for the prevention of cardiometabolic diseases

Exposomics analyses have highlighted the importance of biomonitoring of human exposure to pollutants, even non-persistent, for the prevention of non-communicable diseases like obesity, diabetes, non-alcoholic fatty liver disease, atherosclerosis and cardiovascular diseases. Phthalates and bisphenol A (BPA) are endocrine disrupting chemicals (EDCs) widely used in industry and in a large range of daily life products that increase the risk of endocrine and cardiometabolic diseases especially if the exposure starts during childhood. Thus, it is important the biomonitoring of exposure to these compounds not only in adulthood but also in childhood. This was the goal of the LIFE-PERSUADED project that measured the exposure to phthalates (DEHP metabolites, MEHP, MEHHP, MEOHP) and BPA in Italian mother-children couples of different ages. In this paper we describe the method that was set up for the LIFE PERSUADED project and validated during in the proficiency test (ICI/EQUAS) showing that accurate determination of urinary phthalates and BPA can be achieved starting from small sample size (0.5ml) using two MS techniques applied in cascade on the same deconjugated matrix.

pharmacology and toxicology↗

bioRxiv2020

TM6SF2/PNPLA3/MBOAT7 loss-of-function genetic variants impact on NAFLD development and progression both in patients and in in vitro models

Background and aimsThe I148M PNPLA3, the rs641738 in MBOAT7/TMC4 locus and the E167K TM6SF2 polymorphisms represent the main predisposing factors to non-alcoholic fatty liver disease (NAFLD) development and progression. We previously generated a full knockout of MBOAT7 in HepG2 cells (MBOAT7-/-), homozygous for the I148M PNPLA3. Therefore, we aimed to:1) investigate the synergic impact of the 3 at-risk variants on liver injury and hepatocellular carcinoma (HCC) in a large cohort of NAFLD patients;2) create in vitro models of genetic NAFLD by silencing TM6SF2 in both HepG2 and MBOAT7-/- cells. MethodsNAFLD patients (n=1380) of whom 121 had HCC were stratified with a semi-quantitative score ranging from 0 to 3 according to the number of PNPLA3, TM6SF2 and MBOAT7 at-risk variants. TM6SF2 was silenced in HepG2 (TM6SF2-/-) and MBOAT7-/- (MBOAT7-/-TM6SF2-/-) through CRISPR/Cas9. ResultsIn NAFLD patients, the additive weight of these mutations was associated with liver disease severity and increased risk to develop HCC. In HepG2 cells, TM6SF2 silencing altered lipid composition and induced the accumulation of micro-vesicular LDs, whereas the MBOAT7-/-TM6SF2-/- cells showed a mixed micro/macro pattern of LDs. TM6SF2 deletion strongly affected endoplasmic reticulum (ER) and mitochondria ultrastructures thus increasing ER/oxidative stress. Mitochondrial number raised in both TM6SF2-/- and MBOAT7-/-TM6SF2-/- models, suggesting an unbalancing in mitochondrial dynamics and the silencing of both MBOAT7 and TM6SF2 impaired mitochondrial activity with a shift towards anaerobic glycolysis. MBOAT7-/-TM6SF2-/- cells also showed the highest proliferation rate. ConclusionsThe co-presence of the 3 at-risk variants impacts on NAFLD course, in both patients and experimental models affecting LDs accumulation, mitochondrial functionality and metabolic reprogramming towards HCC.

genetics↗