PROJECT SUMMARY/ABSTRACT Non-alcoholic Fatty Liver Disease (NAFLD) is characterized by hepatocyte fat accumulation in the absence of alcoholic or viral etiologies, and is part of a spectrum of disease ranging from isolated steatosis to hepatocellular carcinoma (HCC). NAFLD is estimated to affect nearly one-quarter of the world's population. As the incidence of NAFLD-associated HCC has risen rapidly over the past few decades, it has become clear that NAFLD is an emerging public health crisis for which there is currently no approved pharmacologic intervention. This project will investigate the role of AKR1a1—a recently discovered protein denitrosylase—in the pathogenesis of NAFLD through interrogation of its role in modulating hepatic lipid metabolism via reversible S- nitrosylation of key lipogenic enzymes. Further, the potential for AKR1a1 as a novel therapeutic target to prevent NAFLD will be investigated. To this end, the study will employ a variety of techniques including: CRISPR-Cas9 genome editing and administration of small molecule inhibitors in dietary models of murine NAFLD; isotope tracing studies to interrogate whole-pathway and enzyme-specific effects on lipid metabolism; resin-assisted capture to assess endogenous S-nitrosylation of enzymes; and site-directed mutagenesis to determine the functional role of S-nitrosylation. Together, this study will provide novel insight into the regulation of hepatic lipid metabolism and the pathophysiology of NAFLD, and identify potential therapeutic targets.

PROJECT NARRATIVE Non-alcoholic fatty liver disease (NAFLD) is a burgeoning public health crisis that is projected to affect nearly 25% of the global population, and may soon become the leading indication for liver transplantation. The role of S-nitrosylation in this disease is poorly understood. The goal of this study is to probe the role of S-nitrosylation in NAFLD through genetic and pharmacologic modulation of the denitrosylase enzyme AKR1a1 in order to better understand its role in the pathophysiology of this disease and to identify AKR1a1-regulated enzymes as potential therapeutic targets.