Deleterious effects of reactive aldehydes and glycated proteins on macrophage proteasomal function: Possible links between diabetes and atherosclerosis

BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR BASIS OF DISEASE

卷:1802

Article

Moheimani, Fatemeh^1,3  Morgan, Philip E.^1,3  van Reyk, David M.²  Davies, Michael J.^1,3 

[1] Heart Res Inst, Free Rad Grp, Newtown, NSW 2042, Australia

[2] Univ Technol, Dept Med & Mol Biosci, Broadway, NSW 2007, Australia

[3] Univ Sydney, Fac Med, Sydney, NSW 2006, Australia

关键词: Diabetes-associated atherosclerosis;    Proteasome;    Glycated proteins;    Advanced glycation end products;    Reactive aldehydes;    Protein turnover;   

DOI  :  10.1016/j.bbadis.2010.02.007

来源: Elsevier

【 摘 要 】

People with diabetes experience chronic hyperglycemia and are at a high risk of developing atherosclerosis and microvascular disease. Reactions of glucose, or aldehydes derived from glucose (e.g. methylglyoxal, glyoxal, or glycolaldehyde), with proteins result in glycation that ultimately yield advanced glycation end products (AGE). AGE are present at elevated levels in plasma and atherosclerotic lesions from people with diabetes, and previous in vitro studies have postulated that the presence of these materials is deleterious to cell function. This accumulation of AGE and glycated proteins within cells may arise from either increased formation and/or ineffective removal by cellular proteolytic systems, such as the proteasomes, the major multi-enzyme complex that removes proteins within cells. In this study it is shown that whilst high glucose concentrations fail to modify proteasome enzyme activities in J774A.1 macrophage-like cell extracts, reactive aldehydes enhanced proteasomal enzyme activities. In contrast BSA, pre-treated with high glucose for 8 weeks, inhibited both the chymotrypsin-like and caspase-like activities. BSA glycated using methylglyoxal or glycolaldehyde, also inhibited proteasomal activity though to differing extents. This suppression of proteasome activity by glycated proteins may result in further intracellular accumulation of glycated proteins with subsequent deleterious effects on cellular function. (C) 2010 Elsevier B.V. All rights reserved.

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