Effects of alpha-tocopherol on ox-LDL-mediated degradation of IkappaB and apoptosis in cultured human coronary artery endothelial cells.
Experimental studies have demonstrated that vitamin E (alpha-tocopherol) may provide significant cytoprotection during cell injury. In this study, we examined the effects of alpha-tocopherol on oxidized low-density lipoprotein (ox-LDL)-induced apoptosis in human coronary artery endothelial cells (HCAECs). In addition, we examined the activation of NF-kappaB pathway in this process. Cultured HCAECs were treated with ox-LDL for 24 h. Incubation of HCAECs with ox-LDL resulted in apoptosis of HCAECs in a concentration-dependent manner, as determined by TUNEL and DNA laddering. Ox-LDL degraded IkappaB and activated NF-kappaB in HCAECs, as determined by Western blot analysis. Treatment with alpha-tocopherol (10 and 50 microM) decreased ox-LDL-mediated apoptosis as well as degradation of IkappaB and activation of NF-kappaB in HCAECs. High concentration of alpha-tocopherol (50 microM) was more effective than the low concentration of alpha-tocopherol (10 microM). Thus, ox-LDL induces apoptosis of HCAECs, in concurrence with degradation of IkappaB and activation of NF-kappaB. Alpha-tocopherol markedly decreases ox-LDL-induced effects.
Li
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D
Department of Medicine, University of Florida and VA Medical Center, Gainesville, USA.
Saldeen
T
T
Mehta
J L
JL
D000975:Antioxidants / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D002478:Cells, Cultured; D003331:Coronary Vessels / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D020672:I-kappa B Proteins / Q000378:metabolism; D008077:Lipoproteins, LDL / Q000633:toxicity*; D016328:NF-kappa B / Q000378:metabolism; D014810:Vitamin E / Q000494:pharmacology*
D000975:Antioxidants; D020672:I-kappa B Proteins; D008077:Lipoproteins, LDL; D016328:NF-kappa B; C099252:oxidized low density lipoprotein; D014810:Vitamin E