Nonalcoholic fatty liver disease (NAFLD), a spectrum extending from nonalcoholic fatty liver (NAFL) to nonalcoholic steatohepatitis (NASH), is the most common cause of chronic liver disease in the Western world. It can lead to cirrhosis and hepatocellular carcinoma (HCC) and is independently associated with an increased risk of death due to cardiovascular and liver diseases. Consumption of high fat and cholesterol containing diet, the Western diet, is an important determinant of obesity and hence NAFLD. The molecular mechanism of NAFLD is gradually being elucidated leading to the evaluation of multiple interventional approaches in clinical trials. However, the optimum therapy is yet to be developed mandating more in-depth understanding of molecular pathogenesis of NAFLD, identification of novel molecules regulating this process and development of targeted therapeutic approaches. We unravel a novel role of Astrocyte elevated gene-1, also known as metadherin (MTDH) and LYRIC, in NASH. A transgenic mouse with hepatocyte-specific overexpression of AEG-1 (Alb/AEG-1) develops spontaneous NASH. NASH patients show increased AEG-1 expression in their liver compared to normal individuals. On the other hand hepatocyte-specific conditional AEG-1 knockout mouse (AEG-1CKOHEP) shows significant resistance to high fat diet (HFD)-induced steatosis. These findings indicate that AEG-1 might play a pivotal role in regulating initiation and progression of NASH. The long term objective of the present proposal is to obtain in-depth understanding of the molecular mechanism of NASH to develop effective therapeutic strategies. The immediate objective is to comprehensively interrogate the molecular mechanism by which AEG-1 promotes NASH and NASH-HCC and evaluate AEG-1 inhibition as a potential interventional strategy for NASH. We hypothesize that multiple events, such as preferential inhibition of nuclear receptors, translational regulation of lipid metabolism regulating genes and activation of inflammation, might contribute to AEG-1-induced NASH and AEG-1 inhibition might interfere with all these events thereby inhibiting development and progression of NASH. A comprehensive functional, biochemical and molecular analyses will be performed to address these hypotheses. Successful completion of the proposed studies will provide in-depth insight into the molecular mechanism by which AEG-1 promotes NASH and help establish AEG-1 inhibition as a potential effective therapeutic strategy for NASH and NASH-HCC. Thus the proposal has high mechanistic and translational significance.

Public Health Relevance

The proposal aims at analyzing the functional role of AEG-1 in nonalcoholic steatohepatitis (NASH) and NASH- HCC using hepatocyte-specific AEG-1 transgenic and conditional knock-out mice fed with high fat diet and evaluating AEG-1 inhibition as an interventional strategy for NASH. These studies will provide novel mechanistic insights into AEG-1 function and facilitate development of a novel therapeutic strategy for NASH.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK107451-04
Application #
9745366
Study Section
Hepatobiliary Pathophysiology Study Section (HBPP)
Program Officer
Doo, Edward
Project Start
2016-07-25
Project End
2020-06-30
Budget Start
2019-07-01
Budget End
2020-06-30
Support Year
4
Fiscal Year
2019
Total Cost
Indirect Cost
Name
Virginia Commonwealth University
Department
Genetics
Type
Schools of Medicine
DUNS #
105300446
City
Richmond
State
VA
Country
United States
Zip Code
23298
Robertson, Chadia L; Mendoza, Rachel G; Jariwala, Nidhi et al. (2018) Astrocyte Elevated Gene-1 Regulates Macrophage Activation in Hepatocellular Carcinogenesis. Cancer Res 78:6436-6446
Hsu, Jack C-C; Reid, David W; Hoffman, Alyson M et al. (2018) Oncoprotein AEG-1 is an endoplasmic reticulum RNA-binding protein whose interactome is enriched in organelle resident protein-encoding mRNAs. RNA 24:688-703
Srivastava, Jyoti; Robertson, Chadia L; Ebeid, Kareem et al. (2017) A novel role of astrocyte elevated gene-1 (AEG-1) in regulating nonalcoholic steatohepatitis (NASH). Hepatology 66:466-480
Jariwala, Nidhi; Rajasekaran, Devaraja; Mendoza, Rachel G et al. (2017) Oncogenic Role of SND1 in Development and Progression of Hepatocellular Carcinoma. Cancer Res 77:3306-3316
Akiel, Maaged; Guo, Chunqing; Li, Xia et al. (2017) IGFBP7 Deletion Promotes Hepatocellular Carcinoma. Cancer Res 77:4014-4025