Nonalcoholic fatty liver disease (NAFLD) results from excessive accumulation of fat in the liver. By itself, hepatic fat accumulation is not life-threatening, but a significant proportion of NAFLD patients progress to more severe forms of the disease characterized by inflammation, fibrosis, and cirrhosis, a condition known as nonalcoholic steatohepatitis (NASH). Although some factors, such as diet, obesity, insulin resistance, and ethnicity, have been associated with hepatic fat storage, clinical characteristics predicting NAFLD progression to more severe forms of fatty liver disease have not yet been identified. Further, little is known of the underlying physiology governing disease progression, and this gap in knowledge is a barrier to predicting which NAFLD patients will develop fibrosis and cirrhosis. The overall plan for this project, therefore, is to identify factors that predict progression of NAFLD to more severe forms of the disease. The specific goals of this study are to first evaluate the relationship between individual and composite predictors of NAFLD progression to steatohepatitis, fibrosis, and cirrhosis. Next, we will utilize a genome-wide approach to genotype 1M markers in 2075 obese individuals and assess association between these markers and NASH severity, as defined by histological grade of hepatic biopsy. All trait-associated markers and haplotypes will be validated in two independent study samples. Finally, we will perform RNA sequencing to measure hepatic gene expression and identify gene networks that are correlated with progressive NASH severity. We will also combine genotype and RNA sequencing data in an innovative approach to identify genetic variants associated with mRNA expression levels in liver samples comprising the entire spectrum of NAFLD stages. Completion of these aims will advance our understanding of NASH development and progression to more severe forms of the disease and may lead to better treatment and prevention strategies for at-risk individuals.

Public Health Relevance

Individuals suffering from obesity, insulin resistance and/or type 2 diabetes often store excessive fat in the liver. By itself, hepatic fat accumulation is not life-threatening, but some affected patients will develop more severe forms of fatty liver disease including steatohepatitis, fibrosis, and cirrhosis; however, no clinical measures are yet available to identify which individuals are most likely to progress. This study will identify genetic variants that modulate severity and progression of nonalcoholic fatty liver disease, which will lead to better treatment and prevention strategies in at-risk individuals.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK091601-05
Application #
8858622
Study Section
Kidney, Nutrition, Obesity and Diabetes (KNOD)
Program Officer
Karp, Robert W
Project Start
2011-07-25
Project End
2017-05-31
Budget Start
2015-06-01
Budget End
2017-05-31
Support Year
5
Fiscal Year
2015
Total Cost
Indirect Cost
Name
Translational Genomics Research Institute
Department
Type
DUNS #
118069611
City
Phoenix
State
AZ
Country
United States
Zip Code
85004
Chu, Xin; Jin, Qunyan; Chen, Hui et al. (2018) CCL20 is up-regulated in non-alcoholic fatty liver disease fibrosis and is produced by hepatic stellate cells in response to fatty acid loading. J Transl Med 16:108
Wood, G Craig; Chu, Xin; Argyropoulos, George et al. (2017) A multi-component classifier for nonalcoholic fatty liver disease (NAFLD) based on genomic, proteomic, and phenomic data domains. Sci Rep 7:43238
DiStefano, Johanna K (2017) Long noncoding RNAs in the initiation, progression, and metastasis of hepatocellular carcinoma. Noncoding RNA Res 2:129-136
Leti, Fatjon; Legendre, Christophe; Still, Christopher D et al. (2017) Altered expression of MALAT1 lncRNA in nonalcoholic steatohepatitis fibrosis regulates CXCL5 in hepatic stellate cells. Transl Res 190:25-39.e21
O'Hare, Elizabeth A; Yang, Rongze; Yerges-Armstrong, Laura M et al. (2017) TM6SF2 rs58542926 impacts lipid processing in liver and small intestine. Hepatology 65:1526-1542
Mosley, J D; Shaffer, C M; Van Driest, S L et al. (2016) A genome-wide association study identifies variants in KCNIP4 associated with ACE inhibitor-induced cough. Pharmacogenomics J 16:231-7
DiStefano, Johanna K; Gerhard, Glenn S (2016) Circulating microRNAs in nonalcoholic fatty liver disease. Expert Rev Gastroenterol Hepatol 10:161-3
Benotti, Peter; Wood, G Craig; Argyropoulos, George et al. (2016) The impact of obstructive sleep apnea on nonalcoholic fatty liver disease in patients with severe obesity. Obesity (Silver Spring) 24:871-7
Gerhard, Glenn S; Still, Christopher D; DiStefano, Johanna K (2016) High False-Negative Rate for Nonalcoholic Steatohepatitis in Extreme Obesity. Gastroenterology 150:283-4
Roesch, Stephen L; Styer, Amanda M; Wood, G Craig et al. (2015) Perturbations of fibroblast growth factors 19 and 21 in type 2 diabetes. PLoS One 10:e0116928

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