(P30-059-24) Study Protocol: Investigating the Mechanisms by Which Ketogenic Diet Mediates Alleviation of Metabolic Dysfunction-Associated Fatty Liver Disease (MAFLD)

Objectives: Delineate the role of cholesterol metabolite, bile acids (BAs) and their signaling towards the beneficial effects of low-carbohydrate ketogenic diet (KD) during obesity and MAFLD. It is a conundrum that KD (0.4% carbohydrate, 95% fat, and 4.5% protein by calorie) is beneficial to alleviate MAFLD whereas a western diet (WD) (40.7% carbohydrate, 44.6% fat, and 14.7% protein by calorie) promotes it. These studies highlight the relevance of dietary composition.

Methods: Study the transcriptional changes in adipocytes upon dietary challenge using a transgenic NuTRAP mouse line combining ribosome and nuclear tagging strategy. This allows simultaneous isolation of adipocyte mRNA and nuclei using an adiponectin-cre line. MAFLD will be induced in 8-10 week old NuTRAP mice through WD. One group of mice will be challenged as an intervention with a 4 week low-carbohydrate KD, the other will be fed with chow. Metabolic changes will be analyzed using a comprehensive lab animal monitoring system (CLAMS). Adipocyte RNA will be isolated for sequencing and chromatin analysis will also be performed, as well as histological examination of liver and adipose tissue and biochemical serum parameters (glucose, cholesterol, ketone bodies, BA, free fatty acids and  non-esterified fatty acids).

Results: Recent data showed how a low carb KD diet works well for MAFLD treatment, improves insulin resistance, and reduces hepatic fat deposits. We’ve previously shown that BA are important for adipocyte size maintenance, affecting AT remodeling and fat burning and its signaling receptor loss, farnesoid x receptor in AT results in MAFLD indicating a liver to AT cross talk. . Therefore, we’ll test if BA levels or their downstream signaling are altered with low carb KD intervention. Using the NuTRAP mice model, we’ll perform adipose transcriptome and epigenome analysis. These results will be presented in ASN 2024.

Conclusions: We expect to uncover the BA signaling role to mediate the beneficial response to low carb KD. The genome-wide studies with NuTRAP mice will reveal the transcriptomic changes, along with the biochemical data from serum analysis to also help us decipher the mechanism underlying KD-mediated MAFLD treatment.

Funding Sources: This work was supported by R01 DK130317 from NIDDK (to S.A.) and CONACyT (Ximena Yrigoyen).