Non-alcoholic fatty liver disease (NAFLD) is one of the major health concerns worldwide. However, the underlying mechanism has been poorly understood. MicroRNAs (miRNAs) are small (19-22 nucleotide) noncoding RNA molecules that bind to the 3' untranslated region (3'-UTR) of mRNAs to post- transcriptionally regulate gene expression, usually leading to inhibition of gene expression. Recent data have demonstrated that miRNAs play an important role in regulating lipid and glucose metabolism as well as many other biological processes. Nuclear hormone receptors are ligand-activated transcription factors that regulate both development and adult physiology. Hepatocyte nuclear factor 4? (HNF4?) is a member of the nuclear hormone receptor superfamily and has been shown to play a critical role in maintaining bile acid, lipid and glucose homeostasis. Although loss of hepatic HNF4? is known to cause liver steatosis, the role of HNF4? in the progression of NAFLD has not been investigated before. Our preliminary data have shown that 1) patients with non-alcoholic steatohepatitis (NASH) have a significant increase in miR-34a and miR-149 expression and a marked decrease in HNF4? expression, 2) diabetic mice or high fat diet (HFD)-fed mice also have increased hepatic miR-34a and miR-149 expression and a significant reduction in hepatic HNF4? expression, and 3) over-expression of hepatic miR-34a or miR-149 causes a reduction in hepatic HNF4? expression and an increase in hepatic triglyceride (TG) levels. Based on these preliminary data, we hypothesize that in response to specific metabolic cue(s), a cascade involving miR-34a, miR-149 and HNF4? is activated to increase hepatic TG levels, therefore facilitating the development and progression of NAFLD. To test this hypothesis, we will utilize both gain- and loss-of-function approaches to further characterize the role of miR-34a, miR-149 and HNF4??in hepatic TG metabolism and the development and progression of NAFLD. Accomplishing the specific aims proposed in this application will provide novel and important insights into the mechanism underlying the pathogenesis of NAFLD, and may lead to identification of novel target(s) for treatment of NAFLD.

Public Health Relevance

Non-alcoholic fatty liver disease (NAFLD) is one of the most common liver diseases in humans. Completion of the proposed studies will help determine whether a cascade involving miR-34a, miR-149 and HNF4? plays an important role in the pathogenesis of NAFLD, and may lead to new strategies for treatment of NAFLD. Thus, the studies proposed in this application are highly relevant to human health.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
1R01DK102619-01A1
Application #
8884995
Study Section
Hepatobiliary Pathophysiology Study Section (HBPP)
Program Officer
Doo, Edward
Project Start
2015-07-01
Project End
2020-06-30
Budget Start
2015-07-01
Budget End
2016-06-30
Support Year
1
Fiscal Year
2015
Total Cost
Indirect Cost
Name
Northeast Ohio Medical University
Department
Other Basic Sciences
Type
Schools of Medicine
DUNS #
077779882
City
Rootstown
State
OH
Country
United States
Zip Code
44272
Singh, Amar Bahadur; Dong, Bin; Kraemer, Fredric B et al. (2018) Farnesoid X Receptor Activation by Obeticholic Acid Elevates Liver Low-Density Lipoprotein Receptor Expression by mRNA Stabilization and Reduces Plasma Low-Density Lipoprotein Cholesterol in Mice. Arterioscler Thromb Vasc Biol 38:2448-2459
Jadhav, Kavita; Xu, Yang; Xu, Yanyong et al. (2018) Reversal of metabolic disorders by pharmacological activation of bile acid receptors TGR5 and FXR. Mol Metab 9:131-140
Jadhav, Kavita; Zhang, Yanqiao (2017) Activating transcription factor 3 in immune response and metabolic regulation. Liver Res 1:96-102
Park, Jung Eun; Lee, Mikang; Kim, Seong-Chul et al. (2017) Hairy and enhancer of split 6 prevents hepatic lipid accumulation through inhibition of Pparg2 expression. Hepatol Commun 1:1085-1098
Zhang, Guoning; Liu, Shuainan; Tan, Wenjuan et al. (2017) Synthesis and biological evaluations of chalcones, flavones and chromenes as farnesoid x receptor (FXR) antagonists. Eur J Med Chem 129:303-309
Xu, Jiesi; Xu, Yang; Xu, Yanyong et al. (2017) Global inactivation of carboxylesterase 1 (Ces1/Ces1g) protects against atherosclerosis in Ldlr -/- mice. Sci Rep 7:17845
Xu, Jiesi; Xu, Yang; Li, Yuanyuan et al. (2016) Carboxylesterase 1 Is Regulated by Hepatocyte Nuclear Factor 4? and Protects Against Alcohol- and MCD diet-induced Liver Injury. Sci Rep 6:24277
Li, Yuanyuan; Zalzala, Munaf; Jadhav, Kavita et al. (2016) Carboxylesterase 2 prevents liver steatosis by modulating lipolysis, endoplasmic reticulum stress, and lipogenesis and is regulated by hepatocyte nuclear factor 4 alpha in mice. Hepatology 63:1860-74
Xu, Yang; Li, Fei; Zalzala, Munaf et al. (2016) Farnesoid X receptor activation increases reverse cholesterol transport by modulating bile acid composition and cholesterol absorption in mice. Hepatology 64:1072-85
Xu, Yang; Zalzala, Munaf; Xu, Jiesi et al. (2015) A metabolic stress-inducible miR-34a-HNF4? pathway regulates lipid and lipoprotein metabolism. Nat Commun 6:7466