The Role of De Novo Lipogenesis in Regulation of Insulin Sensitivity in Adipose Tissue in Obese

The main goal of the proposed project is to characterize the regulation of de novo lipogenesis in AT, a pathway strongly associated with insulin sensitivity in humans. The project should provide information that will bring proof-of-concept for the development of AT DNL-targeting therapeutic strategies to decrease the metabolic risk in obese individuals. Two protocols in lean and obese women to modulate (inhibit/induce) DNL will be implemented: 1) two days of fasting followed by two days of high-carbohydrate diet refeeding (FAST/RF) in lean and obese women; 2) "fasting-mimicking" intervention in obese women with high fat low carbohydrate ketogenic diet followed by two days of high-carbohydrate diet refeeding (KETO/RF). KETO diet should provide long lasting AT DNL inhibition, and as such it should further highlight the processes necessary for DNL activation in the refeeding phase. The unique protocols proposed in the application will allow to investigate in humans the relationship between AT DNL and whole body insulin sensitivity and glucose tolerance. Moreover, the state of the art experimental methodologies applied for the analyses of AT samples should uncover the possible mechanisms of regulation of DNL by ChREBP, HSL and other factors as well as the related AT secretory capacity in humans. The findings obtained in lean subjects will be compared to obese subjects, as the deregulated response of these pathways might be expected. The project will provide a proof-of-principle for the role of AT DNL in the regulation of insulin sensitivity in lean and obese individuals. The results will indicate novel pathways for future development of drugs targeting the relevant sites in AT in the context of treatment of obesity-induced insulin resistance and associated disorders.