Constitutive hsp70 attenuates hydrogen peroxide-induced membrane lipid peroxidation.
Thermal pretreatment improves cardiac recovery from subsequent ischemia/reperfusion. Induction of heat shock proteins (hsps) may contribute to this protection. We have demonstrated that augmentation of the constitutive hsp70 (hsc70) in H9c2 heart myoblasts promotes oxidative resistance. We employed a model oxidant to explore potential target(s) of protection by hsc70. Upon exposure to 54 microM of hydrogen peroxide (H(2)O(2)), hsc70-overexpressing cells exhibited a lower lipid peroxidation than the sham-transfected control. Constitutive hsc70 overexpression, however, did not protect against H(2)O(2)-induced depletion of ATP and glutathione (GSH). Lipid protection also occurred in cells preconditioned at 39 degrees C (selectively induces hsc70) during H(2)O(2) exposure. Interestingly, the protection conferred by hsc70 was comparable in magnitude to that provided by alpha-tocopherol, and was followed with a reduced release of lactate dehydrogenase and a unaltered calcium uptake during H(2)O(2) challenge. Collectively, our observations suggest that hsc70 may preserve membrane function via attenuation of lipid peroxidation during oxidative insult.
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Department of Medicine, Southern Illinois University School of Medicine, Springfield, Illinois, 62794, USA.
Chong
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Edelstein
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Lille
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Khardori
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Lai
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D000818:Animals; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D015870:Gene Expression; D050883:HSC70 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D006321:Heart / Q000187:drug effects; D006861:Hydrogen Peroxide / Q000633:toxicity*; D015227:Lipid Peroxidation / Q000187:drug effects*; D008563:Membrane Lipids / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism; D018384:Oxidative Stress; D051381:Rats; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
D002352:Carrier Proteins; D050883:HSC70 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; C494373:Hspa8 protein, rat; D008563:Membrane Lipids; D011994:Recombinant Proteins; D006861:Hydrogen Peroxide