Effect of 7beta-hydroxycholesterol on cellular redox status and heat shock protein 70 expression in macrophages.
The proatherogenic effects of oxidized low-density lipoproteins are attributed to oxysterols, particularly 7beta-hydroxycholesterol. In the present study, we have examined the effect of 7beta-hydroxycholesterol on cellular redox status and heat shock protein 70 (hsp70) expression. Murine peritoneal macrophages were incubated for 24 hours with increasing concentrations of 7beta-hydroxycholesterol (0-25 microg/ml). Intracellular reduced glutathione levels decreased and oxidized glutathione levels increased, thus increasing the redox ratio. Hsp70 expression in macrophages decreased in a dose-dependent fashion. It is suggested that 7beta-hydroxycholesterol exerts oxidative stress on macrophages and makes them more susceptible to its proatherogenic effects by impairing the cellular defense system consisting of antioxidants and stress proteins.
Bansal
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G
Department of Biophysics, Panjab University, Chandigarh-160014, India. mpbansal@pu.ac.in
Singh
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Bansal
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MP
D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003593:Cytoplasm / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005978:Glutathione / Q000378:metabolism; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D006888:Hydroxycholesterols / Q000494:pharmacology*; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010084:Oxidation-Reduction; D018384:Oxidative Stress
D018840:HSP70 Heat-Shock Proteins; D006888:Hydroxycholesterols; C011724:cholest-5-en-3 beta,7 alpha-diol; D005978:Glutathione