Document Detail


PKCβ inhibition with ruboxistaurin reduces oxidative stress and attenuates left ventricular hypertrophy and dysfunction in rats with streptozotocin-induced diabetes.
MedLine Citation:
PMID:  21892921     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Oxidative stress plays critical roles in the development of diabetic cardiovascular complications, including myocardial hypertrophy. The β isoform of PKC (protein kinase C) is preferentially overexpressed in the myocardium of diabetic subjects accompanied with increased activation of the pro-oxidant enzyme NADPH oxidase, which may exacerbate oxidative stress. We hypothesized that myocardial PKCβ is a major upstream mediator of oxidative stress in diabetes and that PKCβ inhibition can attenuate myocardial hypertrophy and dysfunction. Control or streptozotocin-induced diabetic rats were treated with the selective PKCβ inhibitor RBX (ruboxistaurin; 1 mg/kg of body weight per day) or the antioxidant NAC (N-acetylcysteine) for 4 weeks. LV (left ventricular) dimensions and functions were detected by echocardiography. 15-F2t-isoprostane (a specific index of oxidative stress) and myocardial activities of superoxide dismutase as well as protein levels of NADPH oxidase were assessed by immunoassay or Western blotting. Echocardiography revealed that the LV mass/body weight ratio was significantly increased in diabetic rats (P<0.01 compared with the control group) in parallel with the impaired LV relaxation. A significant increase in cardiomyocyte cross-sectional area was observed in diabetic rats accompanied by an increased production of O2- (superoxide anion) and 15-F2t-isoprostane (all P<0.05 compared with the control group). RBX normalized these changes with concomitant inhibition of PKCβ2 activation and prevention of NADPH oxidase subunit p67phox membrane translocation and p22phox overexpression. The effects of RBX were comparable with that of NAC, except that NAC was inferior to RBX in attenuating cardiac dysfunction. It is concluded that RBX can ameliorate myocardial hypertrophy and dysfunction in diabetes, which may represent a novel therapy in the prevention of diabetic cardiovascular complications.
Authors:
Yanan Liu; Shaoqing Lei; Xia Gao; Xiaowen Mao; Tingting Wang; Gordon T Wong; Paul M Vanhoutte; Michael G Irwin; Zhengyuan Xia
Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Clinical science (London, England : 1979)     Volume:  122     ISSN:  1470-8736     ISO Abbreviation:  Clin. Sci.     Publication Date:  2012 Feb 
Date Detail:
Created Date:  2011-10-27     Completed Date:  2011-12-19     Revised Date:  2012-01-05    
Medline Journal Info:
Nlm Unique ID:  7905731     Medline TA:  Clin Sci (Lond)     Country:  England    
Other Details:
Languages:  eng     Pagination:  161-73     Citation Subset:  IM    
Affiliation:
Department of Anesthesiology, The University of Hong Kong, China.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Acetylcysteine / pharmacology,  therapeutic use
Animals
Diabetes Mellitus, Experimental / complications
Diabetic Cardiomyopathies / prevention & control*
Drug Evaluation, Preclinical
Enzyme Activation / drug effects
Free Radical Scavengers / pharmacology,  therapeutic use
Hypertrophy, Left Ventricular / etiology,  prevention & control*,  ultrasonography
Indoles / pharmacology,  therapeutic use*
Isoprostanes / blood
Male
Maleimides / pharmacology,  therapeutic use*
Myocytes, Cardiac / drug effects,  enzymology
NADPH Oxidase / antagonists & inhibitors,  metabolism
Oxidative Stress / drug effects*
Protein Kinase C / antagonists & inhibitors*
Rats
Rats, Sprague-Dawley
Superoxides / metabolism
Chemical
Reg. No./Substance:
0/15-F2t-isoprostane; 0/Free Radical Scavengers; 0/Indoles; 0/Isoprostanes; 0/Maleimides; 11062-77-4/Superoxides; 169939-94-0/ruboxistaurin; 616-91-1/Acetylcysteine; EC 1.6.3.1/NADPH Oxidase; EC 2.7.1.-/protein kinase C beta; EC 2.7.11.13/Protein Kinase C

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Hsp70 in Oncology.
Next Document:  Selenium-containing amino acids are major targets for myeloperoxidase-derived hypothiocyanous acid: ...