| Curcumin prevents leptin raising glucose levels in hepatic stellate cells by blocking translocation of glucose transporter-4 and increasing glucokinase. | |
| | |
MedLine Citation:
|
PMID: 20977462 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
BACKGROUND AND PURPOSE: Hyperleptinemia is commonly found in obese patients, associated with non-alcoholic steatohepatitis and hepatic fibrosis. Hepatic stellate cells (HSCs) are the most relevant effectors during hepatic fibrogenesis. We recently reported that leptin stimulated HSC activation, which was eliminated by curcumin, a phytochemical from turmeric. This study was designed to explore the underlying mechanisms, focusing on their effects on intracellular glucose in HSCs. We hypothesized that leptin stimulated HSC activation by elevating the level of intracellular glucose, which was eliminated by curcumin by inhibiting the membrane translocation of glucose transporter-4 (GLUT4) and inducing the conversion of glucose to glucose-6-phosphate (G-6-P). EXPERIMENTAL APPROACH: Levels of intracellular glucose were measured in rat HSCs and immortalized human hepatocytes. Contents of GLUT4 in cell fractions were analysed by Western blotting analyses. Activation of signalling pathways was assessed by comparing phosphorylation levels of protein kinases. KEY RESULTS: Leptin elevated the level of intracellular glucose in cultured HSCs, which was diminished by curcumin. Curcumin suppressed the leptin-induced membrane translocation of GLUT4 by interrupting the insulin receptor substrates/phosphatidyl inositol 3-kinase/AKT signalling pathway. Furthermore, curcumin stimulated glucokinase activity, increasing conversion of glucose to G-6-P. CONCLUSIONS AND IMPLICATIONS: Curcumin prevented leptin from elevating levels of intracellular glucose in activated HSCs in vitro by inhibiting the membrane translocation of GLUT4 and stimulating glucose conversion, leading to the inhibition of HSC activation. Our results provide novel insights into mechanisms of curcumin in inhibiting leptin-induced HSC activation. |
| | |
Authors:
|
Youcai Tang; Anping Chen |
Publication Detail:
|
Type: Journal Article; Research Support, N.I.H., Extramural |
Journal Detail:
|
Title: British journal of pharmacology Volume: 161 ISSN: 1476-5381 ISO Abbreviation: Br. J. Pharmacol. Publication Date: 2010 Nov |
Date Detail:
|
Created Date: 2010-10-27 Completed Date: 2011-02-10 Revised Date: 2011-11-01 |
Medline Journal Info:
|
Nlm Unique ID: 7502536 Medline TA: Br J Pharmacol Country: England |
Other Details:
|
Languages: eng Pagination: 1137-49 Citation Subset: IM |
Copyright Information:
|
© 2010 The Authors. British Journal of Pharmacology © 2010 The British Pharmacological Society. |
Affiliation:
|
Department of Pathology, School of Medicine, Saint Louis University, 1100 S.Grand Boulevard, St Louis, MO 63104, USA. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Animals Blotting, Western Cells, Cultured Curcumin / pharmacology* Glucokinase / drug effects*, metabolism Glucose / metabolism Glucose Transporter Type 4 / metabolism* Hepatic Stellate Cells / drug effects, metabolism Hepatocytes / drug effects, metabolism Humans Leptin / metabolism* Male Phosphorylation / drug effects Protein Transport Rats Rats, Sprague-Dawley Rats, Zucker |
| Grant Support | |
ID/Acronym/Agency:
|
R01 DK 047995/DK/NIDDK NIH HHS |
| Chemical | |
Reg. No./Substance:
|
0/Glucose Transporter Type 4; 0/Leptin; 458-37-7/Curcumin; 50-99-7/Glucose; EC 2.7.1.2/Glucokinase |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Agonists at the ?-opioid receptor modify the binding of µ-receptor agonists to the µ-? receptor he...
Next Document: Inhibition of vascular ectonucleotidase activities by the pro-drugs ticlopidine and clopidogrel favo...