Disruption of adenosine 2A receptor exacerbates NAFLD through increasing inflammatory responses and SREBP1c activity
- 9 January 2018
- journal article
- research article
- Published by Ovid Technologies (Wolters Kluwer Health) in Hepatology
- Vol. 68 (1), 48-61
- https://doi.org/10.1002/hep.29777
Abstract
Adenosine 2A receptor (A2AR) exerts protective roles in endotoxin‐ and/or ischemia‐induced tissue damage. However, the role for A2AR in nonalcoholic fatty liver disease (NAFLD) remains largely unknown. We sought to examine the effects of global and/or myeloid cell‐specific A2AR disruption on the aspects of obesity‐associated NAFLD and to elucidate the underlying mechanisms. Global and/or myeloid cell–specific A2AR‐disrupted mice and control mice were fed a high‐fat diet (HFD) to induce NAFLD. In addition, bone marrow–derived macrophages and primary mouse hepatocytes were examined for inflammatory and metabolic responses. Upon feeding an HFD, both global A2AR‐disrupted mice and myeloid cell–specific A2AR‐defcient mice revealed increased severity of HFD‐induced hepatic steatosis and inflammation compared with their respective control mice. In in vitro experiments, A2AR‐deficient macrophages exhibited increased proinflammatory responses, and enhanced fat deposition of wild‐type primary hepatocytes in macrophage–hepatocyte cocultures. In primary hepatocytes, A2AR deficiency increased the proinflammatory responses and enhanced the effect of palmitate on stimulating fat deposition. Moreover, A2AR deficiency significantly increased the abundance of sterol regulatory element‐binding protein 1c (SREBP1c) in livers of fasted mice and in hepatocytes upon nutrient deprivation. In the absence of A2AR, SREBP1c transcription activity was significantly increased in mouse hepatocytes. Conclusion: Taken together, our results demonstrate that disruption of A2AR in both macrophage and hepatocytes accounts for increased severity of NAFLD, likely through increasing inflammation and through elevating lipogenic events due to stimulation of SREBP1c expression and transcription activity. (Hepatology 2018;68:48‐61).Keywords
Funding Information
- American Diabetes Association (1-17-IBS-145)
- National Institutes of Health (DK095862, HL095556, DK062975, DK054811)
- Dr. Nicholas C. Hightower Centennial Chair of Gastroenterology from Scott & White
- VA Research Career Scientist Award
- Hatch Program of the National Institutes of Food and Agriculture
- China Scholarship Council
This publication has 40 references indexed in Scilit:
- Adenosine 2A Receptor Antagonist Prevented and Reversed Liver Fibrosis in a Mouse Model of Ethanol-Exacerbated Liver FibrosisPLOS ONE, 2013
- Regulation of lipogenesis by cyclin-dependent kinase 8–mediated control of SREBP-1JCI Insight, 2012
- Palmitoleate Induces Hepatic Steatosis but Suppresses Liver Inflammatory Response in MicePLOS ONE, 2012
- Human Fatty Liver Disease: Old Questions and New InsightsScience, 2011
- AMPK Phosphorylates and Inhibits SREBP Activity to Attenuate Hepatic Steatosis and Atherosclerosis in Diet-Induced Insulin-Resistant MiceCell Metabolism, 2011
- Suppression of Long Chain Acyl-CoA Synthetase 3 Decreases Hepatic de Novo Fatty Acid Synthesis through Decreased Transcriptional ActivityPublished by Elsevier BV ,2009
- Adenosine receptors: therapeutic aspects for inflammatory and immune diseasesNature Reviews Drug Discovery, 2008
- Adipocyte-Derived Th2 Cytokines and Myeloid PPARδ Regulate Macrophage Polarization and Insulin SensitivityCell Metabolism, 2008
- Alternative M2 Activation of Kupffer Cells by PPARδ Ameliorates Obesity-Induced Insulin ResistanceCell Metabolism, 2008
- Nonalcoholic Fatty Liver Disease: From Steatosis to CirrhosisHepatology, 2006