Hyodeoxycholic acid ameliorates nonalcoholic fatty liver disease by inhibiting RAN-mediated PPARa nucleus-cytoplasm shuttling

Nonalcoholic fatty liver disease (NAFLD) is usually characterized with disrupted bile acid (BA) homeostasis. However, the exact role of certain BA in NAFLD is poorly understood. Here we show levels of serum hyodeoxycholic acid (HDCA) decrease in both NAFLD patients and mice, as well as in liver and intestinal contents of NAFLD mice compared to their healthy counterparts. Serum HDCA is also inversely correlated with NAFLD severity. Dietary HDCA supplementation ameliorates diet-induced NAFLD in male wild type mice by activating fatty acid oxidation in hepatic peroxisome proliferator-activated receptor & alpha; (PPAR & alpha;)-dependent way because the anti-NAFLD effect of HDCA is abolished in hepatocyte-specific Ppar & alpha; knockout mice. Mechanistically, HDCA facilitates nuclear localization of PPAR & alpha; by directly interacting with RAN protein. This interaction disrupts the formation of RAN/CRM1/PPAR & alpha; nucleus-cytoplasm shuttling heterotrimer. Our results demonstrate the therapeutic potential of HDCA for NAFLD and provide new insights of BAs on regulating fatty acid metabolism. Nonalcoholic fatty liver disease (NAFLD) is often linked to disrupted bile acid homeostasis. Here, the authors show hyodeoxycholic acid (HDCA) ameliorates nonalcoholic fatty liver disease by inhibiting the formation of RAN/CRM1/PPAR & alpha; nuclear export heterotrimer, resulting in increased nuclear localization of PPAR & alpha; and activated fatty acid oxidation.

Automated summary

Nonalcoholic fatty liver disease (NAFLD) is associated with disrupted bile acid homeostasis. The authors demonstrate that hyodeoxycholic acid (HDCA) ameliorates NAFLD by inhibiting the formation of RAN/CRM1/PPARα nuclear export heterotrimer, which leads to increased nuclear localization of PPARα and activation of fatty acid oxidation.