RESUMEN
Chronic high-fat diet feeding is associated with obesity and accumulation of fat in the liver, leading to the development of insulin resistance and nonalcoholic fatty liver disease. This condition is characterized by the presence of a high number of intrahepatic lipid droplets (LDs), with changes in the perilipin pattern covering them. This work aimed to describe the distribution of perilipin (Plin) 2, an LD-associated protein involved in neutral lipid storage, and Plin5, which favors lipid oxidation in LD, and to evaluate lipid peroxidation through live-cell visualization using the lipophilic fluorescent probe C11-BODIPY581/591 in fresh hepatocytes isolated from mice fed a high-fat diet (HFD). Male C57BL/6J adult mice were divided into control and HFD groups and fed with a control diet (10% fat, 20% protein, and 70% carbohydrates) or an HFD (60% fat, 20% protein, and 20% carbohydrates) for 8 weeks. The animals fed the HFD showed a significant increase of Plin2 in LD of hepatocytes. LD from HFD-fed mice have a stronger lipid peroxidation level than control hepatocytes. These data provide evidence that obesity status is accompanied by a higher degree of lipid peroxidation in hepatocytes, both in the cytoplasm and in the fats stored inside the LD. Novelty Our study shows that lipid droplets from isolated hepatocytes in HFD-fed mice have a stronger lipid peroxidation level than control hepatocytes. C11-BODIPY581/591 is a useful tool to measure the initial level of intracellular lipid peroxidation in single isolated hepatocytes. Perilipins pattern changes with HFD feeding, showing an increase of Plin2 covering lipid droplets.
Asunto(s)
Hepatocitos/metabolismo , Gotas Lipídicas/metabolismo , Peroxidación de Lípido , Obesidad/metabolismo , Perilipina-2/metabolismo , Animales , Dieta Alta en Grasa , Metabolismo de los Lípidos , Hígado/metabolismo , Masculino , Ratones Endogámicos C57BLRESUMEN
This study aimed to investigate the individual characteristics of body composition and metabolic profile that could explain interindividual variation in high-density lipoprotein cholesterol (HDL-c) concentrations in response to 16 weeks of combined strength plus aerobic (combined) training in postmenopausal women. The participants were divided into tertiles based on percentage of changes in HDL-c concentrations after combined training. Only women in the upper tertile (positive responders: Δ > 10.4%; n = 19) and lower tertile (negative responders: Δ < -1.4%; n = 19) were considered for analyses. The total body fat (BF), trunk fat (TF), android fat (AF), gynoid fat, and lean body mass were estimated by dual-energy X-ray absorptiometry. The metabolic profile - glucose, triacylglycerol, total cholesterol, HDL-c, low-density lipoprotein cholesterol, and very-low-density lipoprotein (VLDL) - were assessed. After 16 weeks, both positive and negative responders presented similar improvement in body composition, such as a decrease in percentage and kilograms of BF, TF, and AF, and increase in lean body mass (p value for time < 0.05). As expected, there was an effect of time and also a significant interaction (time vs. group) (p value < 0.001) in the improvement of HDL-c, with higher values for positive responders. Regarding metabolic profile, there were significant interactions (time vs. group) for triacylglycerol (p value = 0.032) and VLDL (p value = 0.027) concentrations, with lower values for positive responders. Our results suggests there is heterogeneity in combined training-induced HDL-c changes in postmenopausal women, and the positive responders were those who presented more pronounced decreases in triacylglycerol and VLDL concentrations.