Transcriptional suppression of the function of the Type II nuclear receptor (NR) superfamily member and heterodimer partner to ~17 NRs in liver-the Retinoid X Receptor ? (RXR?, NR2B1)-underlies most of the inflammation-mediated changes in liver biology, including a suppression of bile acid (BA) transport. The overall unifying hypothesis is that inflammatory cell signaling pathways modulate RXR? activities by post-translational modification (PTM)->altered genome-wide RXR? chromatin site occupancy->reduced RXR? heterodimer function->broad changes in RXR?-dependent gene expression in liver->increased BA retention->exacerbation of liver damage. These studies are aimed at two PTMs-phosphorylation of S260 and SUMOylation of K108. Moreover, detailed ChIP-SEQ mapping of the alterations in RXR? genome wide binding in response to bile acids and inflammation in mouse liver, along with potential attenuation with select therapeutic NR ligands will provide insight into the whole liver changes in RXR? heterodimer site chromatin occupancy, and the effectiveness of NR ligands.

Public Health Relevance

The liver responds to inflammation by changing the expression of thousands of genes, due to changes in the function of a host of nuclear proteins. These nuclear proteins drive liver gene expression for many core functions including the handling of sugars, fats, and bile formation. How they are altered in response to inflammation is poorly understood. These studies are aimed at uncovering the mechanisms and targets of inflammation in liver, with the expectation to provide a detailing mapping and opportunities for therapeutic intervention.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK056239-16
Application #
9281721
Study Section
Hepatobiliary Pathophysiology Study Section (HBPP)
Program Officer
Burgess-Beusse, Bonnie L
Project Start
1999-09-01
Project End
2019-06-30
Budget Start
2017-07-01
Budget End
2019-06-30
Support Year
16
Fiscal Year
2017
Total Cost
Indirect Cost
Name
Emory University
Department
Pediatrics
Type
Schools of Medicine
DUNS #
066469933
City
Atlanta
State
GA
Country
United States
Zip Code
30322
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