Journal of Lipid Research, Vol 38, 2049-2061, Copyright © 1997 by Lipid Research, Inc.

ARTICLES

Ca2+ channel blockers verapamil and nifedipine inhibit apoptosis induced by 25-hydroxycholesterol in human aortic smooth muscle cells

MP Ares, MI Porn-Ares, J Thyberg, L Juntti-Berggren, PO Berggren, U Diczfalusy, B Kallin, I Bjorkhem, S Orrenius and J Nilsson
King Gustav Vth Research Institute, Department of Medicine, Stockholm, Sweden.

We have characterized the death of human aortic smooth muscle cells induced by 25-hydroxycholesterol, an oxidation product of cholesterol. Chromatin condensation characteristic of apoptosis was observed by enzymatic (TUNEL) staining of chromatin, and by electron microscopy. Fourteen percent of cells treated with 5 microg/ml of 25- hydroxycholesterol for 24 h displayed chromatin degradation as determined by positive TUNEL staining. Addition of TNF alpha (10 ng/ml) and IFN gamma (20 ng/ml) increased the proportion of TUNEL positive cells to 30%, whereas the cytokines alone were without effect. After 48 h, 40% of the cells treated with 5 microg/ml of 25-hydroxycholesterol were TUNEL positive, and 21% of the cells displayed chromatin condensation. Oligonucleosomal DNA fragmentation typical of apoptosis was demonstrated by agarose gel electrophoresis. Furthermore, activation of the ICE-like protease caspase 3 (CPP32) was observed in cells treated with 25-hydroxycholesterol. Addition of the Ca2+ entry blockers verapamil or nifedipine to the culture medium inhibited apoptosis by more than 70% and reduced cytotoxicity, while removal of Ca2+ from culture medium reduced apoptosis by 42%. Within a few minutes after addition, 25-hydroxycholesterol induced intracellular Ca2+ oscillations with a frequency of approximately 0.3-0.4 min(-1). Thus it appears that Ca2+ influx through plasma membrane channels is an important signal in oxysterol-induced apoptosis. Addition of TNF alpha and IFN gamma enhanced cytotoxicity and resulted in a higher proportion of apoptotic cells, suggesting that inflammatory cytokines can increase the cytotoxicity of lipid oxidation products.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				E. Pedruzzi, C. Guichard, V. Ollivier, F. Driss, M. Fay, C. Prunet, J.-C. Marie, C. Pouzet, M. Samadi, C. Elbim, et al. NAD(P)H Oxidase Nox-4 Mediates 7-Ketocholesterol-Induced Endoplasmic Reticulum Stress and Apoptosis in Human Aortic Smooth Muscle Cells Mol. Cell. Biol., December 15, 2004; 24(24): 10703 - 10717. [Abstract] [Full Text] [PDF]

				T. Yamada, N. Miyoshi, T. Ogawa, K. Akao, M. Fukuda, T. Ogasawara, Y. Kitagawa, and K. Sano Observation of Molecular Changes of a Necrotic Tissue from a Murine Carcinoma by Fourier-Transform Infrared Microspectroscopy Clin. Cancer Res., June 1, 2002; 8(6): 2010 - 2014. [Abstract] [Full Text] [PDF]

				T.-S. Lee and L.-Y. Chau Fas/Fas ligand-mediated death pathway is involved in oxLDL-induced apoptosis in vascular smooth muscle cells Am J Physiol Cell Physiol, March 1, 2001; 280(3): C709 - C718. [Abstract] [Full Text] [PDF]

				A. E. Rusinol, L. Yang, D. Thewke, S. R. Panini, M. F. Kramer, and M. S. Sinensky Isolation of a Somatic Cell Mutant Resistant to the Induction of Apoptosis by Oxidized Low Density Lipoprotein J. Biol. Chem., March 15, 2000; 275(10): 7296 - 7303. [Abstract] [Full Text] [PDF]

				G. J. Schroepfer Jr. Oxysterols: Modulators of Cholesterol Metabolism and Other Processes Physiol Rev, January 1, 2000; 80(1): 361 - 554. [Abstract] [Full Text] [PDF]

				V. Avdonin, J. Kasuya, M. A. Ciorba, B. Kaplan, T. Hoshi, and L. Iverson Apoptotic proteins Reaper and Grim induce stable inactivation in voltage-gated K+ channels PNAS, September 29, 1998; 95(20): 11703 - 11708. [Abstract] [Full Text] [PDF]

				J. Nilsson, B. Dahlgren, M. Ares, J. Westman, A. H. Nilsson, B. Cercek, and P. K. Shah Lipoprotein-like Phospholipid Particles Inhibit the Smooth Muscle Cell Cytotoxicity of Lysophosphatidycholine and Platelet-Activating Factor Arterioscler. Thromb. Vasc. Biol., January 1, 1998; 18(1): 13 - 19. [Abstract] [Full Text] [PDF]