Lipid droplets are both highly oxidized and Plin2-covered in hepatocytes of diet-induced obese mice

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.