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Mukhopadhyay B, Liu J, Osei-Hyiaman D, Godlewski G, Mukhopadhyay P, Wang L, Jeong WI, Gao B, Duester G, Mackie K, Kojima S, Kunos G. Transcriptional regulation of cannabinoid receptor-1 expression in the liver by retinoic acid acting via retinoic acid receptor-gamma. J Biol Chem 2010; 285:19002-11. [PMID: 20410309 PMCID: PMC2885177 DOI: 10.1074/jbc.m109.068460] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2009] [Revised: 04/19/2010] [Indexed: 11/06/2022] Open
Abstract
Alcoholism can result in fatty liver that can progress to steatohepatitis, cirrhosis, and liver cancer. Mice fed alcohol develop fatty liver through endocannabinoid activation of hepatic CB(1) cannabinoid receptors (CB(1)R), which increases lipogenesis and decreases fatty acid oxidation. Chronic alcohol feeding also up-regulates CB(1)R in hepatocytes in vivo, which could be replicated in vitro by co-culturing control hepatocytes with hepatic stellate cells (HSC) isolated from ethanol-fed mice, implicating HSC-derived mediator(s) in the regulation of hepatic CB(1)R (Jeong, W. I., Osei-Hyiaman, D., Park, O., Liu, J., Bátkai, S., Mukhopadhyay, P., Horiguchi, N., Harvey-White, J., Marsicano, G., Lutz, B., Gao, B., and Kunos, G. (2008) Cell Metab. 7, 227-235). HSC being a rich source of retinoic acid (RA), we tested whether RA and its receptors may regulate CB(1)R expression in cultured mouse hepatocytes. Incubation of hepatocytes with RA or RA receptor (RAR) agonists increased CB(1)R mRNA and protein, the most efficacious being the RARgamma agonist CD437 and the pan-RAR agonist TTNPB. The endocannabinoid 2-arachidonoylglycerol (2-AG) also increased hepatic CB(1)R expression, which was mediated indirectly via RA, because it was absent in hepatocytes from mice lacking retinaldehyde dehydrogenase 1, the enzyme catalyzing the generation of RA from retinaldehyde. The binding of RARgamma to the CB(1)R gene 5' upstream domain in hepatocytes treated with RAR agonists or 2-AG was confirmed by chromatin immunoprecipitation and electrophoretic mobility shift and antibody supershift assays. Finally, TTNPB-induced CB(1)R expression was attenuated by small interfering RNA knockdown of RARgamma in hepatocytes. We conclude that RARgamma regulates CB(1)R expression and is thus involved in the control of hepatic fat metabolism by endocannabinoids.
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Affiliation(s)
- Bani Mukhopadhyay
- From the Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland 20892-9413
| | - Jie Liu
- From the Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland 20892-9413
| | - Douglas Osei-Hyiaman
- From the Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland 20892-9413
| | - Grzegorz Godlewski
- From the Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland 20892-9413
| | - Partha Mukhopadhyay
- From the Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland 20892-9413
| | - Lei Wang
- From the Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland 20892-9413
| | - Won-Il Jeong
- From the Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland 20892-9413
| | - Bin Gao
- From the Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland 20892-9413
| | - Gregg Duester
- the Sanford-Burnham Medical Research Institute, La Jolla, California 92037
| | - Ken Mackie
- the Gill Center for Biomolecular Science, Indiana University, Bloomington, Indiana 47405, and
| | - Soichi Kojima
- the Molecular Ligand Biology Research Team, Chemical Genomics Research Group, Chemical Biology Department, RIKEN Advanced Science Institute, Saitam 351-0198, Japan
| | - George Kunos
- From the Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland 20892-9413
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Govindan MV. Recruitment of cAMP-response element-binding protein and histone deacetylase has opposite effects on glucocorticoid receptor gene transcription. J Biol Chem 2010; 285:4489-510. [PMID: 20018896 PMCID: PMC2836055 DOI: 10.1074/jbc.m109.072728] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2009] [Revised: 12/09/2009] [Indexed: 11/06/2022] Open
Abstract
Glucocorticoids control the synthesis of the glucocorticoid receptor (GR) in various tissues through a negative feedback regulation of the mRNA. In this study, we have identified feedback regulatory domains in the human GR gene promoter and examined the roles of GR, the cAMP-response element-binding protein (CREB), and HDAC-6 in association with promoter elements of the human GR gene. Using breast cancer T47D and HeLa-GR cells, we identify specific negative glucocorticoid-response elements in the GR gene. The feedback regulatory domains were also involved in interactions with CREB. GR-bound negative glucocorticoid-response elements recruited HDAC-6, and this was dependent on treatment with dexamethasone. Both CREB and HDAC-6 formed complexes with GR-dexamethasone. The HDAC-6 LXXLL motif between amino acids 313 and 418 made direct contact with the GR AF-1 domain. Interestingly enough, although the level of GR decreased in CREB knockdown cells, it was elevated in HDAC-6 knockdown cells. Our results suggest that CREB-P is dephosphorylated and that HDAC-6 is recruited by the GR, and they play opposite roles in the negative feedback regulation of the GR gene.
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Affiliation(s)
- Manjapra Variath Govindan
- Centre de Recherche en Cancérologie de l'Université Laval, Hôtel-Dieu de Québec, Québec G1R 2J6, Canada.
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