Advanced SearchSearch Tips
7-Ketocholesterol Induces Vascular Smooth Muscle Cell Apoptosis via Akt Degradation
facebook(new window)  Pirnt(new window) E-mail(new window) Excel Download
  • Journal title : Journal of Life Science
  • Volume 26, Issue 2,  2016, pp.226-233
  • Publisher : Korean Society of Life Science
  • DOI : 10.5352/JLS.2016.26.2.226
 Title & Authors
7-Ketocholesterol Induces Vascular Smooth Muscle Cell Apoptosis via Akt Degradation
Seo, Kyo Won; Kim, Chi Dae; Lee, Won Suk;
  PDF(new window)
Vascular smooth muscle cell (VSMC) apoptosis has been identified in various vascular diseases, including atherosclerosis and restenosis after angioplasty, and has been known to precipitate atherosclerotic plaque instability and rupture. Oxysterols are known as inducers of apoptosis in VSMC, and 7-ketocholesterol (7KC) is the major nonenzymically formed oxysterol in atherosclerotic lesions. The precise mechanism underlying VSMC apoptosis is still poorly understood. In this study, we investigated whether 7KC causes apoptosis, and characterized its apoptotic mechanisms in primary cultured rat aortic VSMC. Cell viability was assessed by MTT assay and trypan blue assay. Apoptosis was assessed by flow cytometry, immunofluorescence, immunoprecipitation, and Western blot analyses. 7KC markedly decreased the VSMC viability in a time- and concentration-dependent manner, and increased the production of 4-hydroxynonenal (HNE), a major end-product of lipid peroxidation, which also decreased the VSMC viability. Pretreatment with 2,4-dinitrophenylhydrazine, a well-known reagent of lipid peroxidation-derived aldehydes, significantly restored the 7KC-decreased viability of VSMC. Furthermore, HNE, as well as 7KC, reduced the level of total Akt, a major mediator of cell survival. The 7KC-decreased level of total Akt was significantly restored by pretreatments with 2,4-dinitrophenylhydrazine and N-acetylcysteine. Lactacystin, a proteasome inhibitor, protected VSMC against apoptosis and Akt degradation, but did not inhibit HNE production. In the immunoprecipitation assay, 7KC increased HNE-modified Akt. From the results, it seems that, in atherosclerotic lesions, 7KC induces HNE production in VSMC, and this HNE binds to Akt, proceeding to proteasomal degradation of Akt, through which mechanism the atherosclerotic plaque instability may be facilitated.
4-Hydroxynonenal;7-ketocholesterol;Akt;apoptosis;vascular smooth muscle cell;
 Cited by
Allard, D., Figg, N., Bennett, M. R. and Littlewood, T. D. 2008. Akt regulates the survival of vascular smooth muscle cells via inhibition of FoxO3a and GSK3. J. Biol. Chem. 283, 19739-19747. crossref(new window)

Basso, A. D., Solit, D. B., Chiosis, G., Giri, B., Tsichlis, P. and Rosen, N. 2002. Akt forms an intracellular complex with heat shock protein 90 (Hsp90) and Cdc37 and is destabilized by inhibitors of Hsp90 function. J. Biol. Chem. 277, 39858-39866. crossref(new window)

Bonomini, F., Tengattini, S., Fabiano, A., Bianchi, R. and Rezzani, R. 2008. Atherosclerosis and oxidative stress. Histol. Histopathol. 23, 381-390.

Brown, A. J. and Jessup, W. 1999. Oxysterols and atherosclerosis. Atherosclerosis 142, 1-28. crossref(new window)

Chapple, S. J., Cheng, X. and Mann, G. E. 2013. Effects of 4-hydroxynonenal on vascular endothelial and smooth muscle cell redox signaling and function in health and disease. Redox Biol. 23, 319-331.

Clarke, M. and Bennett, M. 2006. Defining the role of vascular smooth muscle cell apoptosis in atherosclerosis. Cell Cycle 5, 2329-2331. crossref(new window)

Clarke, M. C, Littlewood, T. D., Figg, N., Maguire, J. J., Davenport, A. P., Goddard, M. and Bennett, M. R. 2008. Chronic apoptosis of vascular smooth muscle cells accelerates atherosclerosis and promotes calcification and medial degeneration. Circ. Res. 102, 1529-1538. crossref(new window)

Clarke, M. C., Littlewood, T. D., Figg, N., Maguire, J. J., Davenport, A. P., Goddard, M. and Bennett, M. R. 2008. Chronic apoptosis of vascular smooth muscle cells accelerates atherosclerosis and promotes calcification and medial degeneration. Circ. Res. 20, 1529-1538.

Dickson, B. C. and Gotlieb, A. I. 2003. Towards understanding acute destabilization of vulnerable atherosclerotic plaques. Cardiovasc. Pathol. 12, 237-248. crossref(new window)

Doong, H., Rizzo, K., Fang, S., Kulpa, V., Weissman, A. M. and Kohn, E. C. 2003. CAIR-1/BAG-3 abrogates heat shock protein-70 chaperone complex-mediated protein degradation: accumulation of poly-ubiquitinated Hsp90 client proteins. J. Biol. Chem. 278, 28490-28500. crossref(new window)

Fan, Y., Xie, P., Zhang, H., Guo, S., Gu, D., She, M. and Li, H. 2008. Proteasome-dependent inactivation of Akt is essential for 12-O-tetradecanoylphorbol 13-acetate-induced apoptosis in vascular smooth muscle cells. Apoptosis 13, 1401-1409. crossref(new window)

Guardiola, F., Codony, R., Addis, P. B., Rafecas, M. and Boatella, J. 1996. Biological effects of oxysterols: current status. Food Chem. Toxicol. 34, 193-211. crossref(new window)

Korshunov, V. A. and Berk, B. C. 2008. Smooth muscle apoptosis and vascular remodeling. Curr. Opin. Hematol. 15, 250-254. crossref(new window)

Lawlor, M. A. and Alessi, D. R. 2001. PKB/Akt: a key mediator of cell proliferation, survival and insulin responses? J. Cell Sci. 114, 2903-2910.

Lee, J. Y., Jung, G. Y., Heo, H. J., Yun, M. R., Park, J. Y., Bae, S. S., Hong, K. W., Lee, W. S. and Kim, C. D. 2006. 4-Hydroxynonenal induces vascular smooth muscle cell apoptosis through mitochondrial generation of reactive oxygen species. Toxicol. Lett. 166, 212-221. crossref(new window)

Leonarduzzi, G., Chiarpotto, E., Biasi, F. and Poli, G. 2005. 4-Hydroxynonenal and cholesterol oxidation products in atherosclerosis. Mol. Nutr. Food Res. 49, 1044-1049. crossref(new window)

Littlewood, T. D. and Bennett, M. R. 2003. Apoptotic cell death in atherosclerosis. Curr. Opin. Lipidol. 14, 469-475. crossref(new window)

Madamanchi, N. R., Hakim, Z. S. and Runge, M. S. 2005. Oxidative stress in atherogenesis and arterial thrombosis: the disconnect between cellular studies and clinical outcomes. J. Thromb. Haemost. 3, 254-267. crossref(new window)

Martinet, W. and Kockx, M. M. 2001. Apoptosis in atherosclerosis: focus on oxidized lipids and inflammation. Curr. Opin. Lipidol. 12, 535-541. crossref(new window)

Martinet, W., De Bie, M., Schrijvers, D. M., De Meyer, G. R., Herman, A. G. and Kockx, M. M. 2004. 7-Ketocholesterol induces protein ubiquitination, myelin figure formation, and light chain 3 processing in vascular smooth muscle cells. Arterioscler. Thromb. Vasc. Biol. 24, 2296-2301. crossref(new window)

Martínez-Hervás, S., Vinué, Á., Núñez, L., Andrés-Blasco, I., Piqueras, L., Real, J. T., Ascaso, J. F., Burks, D. J., Sanz, M. J. and González-Navarro, H. 2014. Insulin resistance aggravates atherosclerosis by reducing vascular smooth muscle cell survival and increasing CX3CL1/CX3CR1 axis. Cardiovasc. Res. 103, 324-336. crossref(new window)

Ozaki, H., Miyashita, Y., Watanabe, H. and Shirai, K. 2005. Enhancement of MMP-9 activity in THP-1 cells by 7-ketocholesterol and its suppression by the HMG-CoA reductase inhibitor fluvastatin. J. Atheroscler. Thromb. 12, 308-314. crossref(new window)

Perales, S., Alejandre, M. J., Palomino-Morales, R., Torres, C. and Linares, A. 2010. Influence of cholesterol and fish oil dietary intake on nitric oxide-induced apoptosis in vascular smooth muscle cells. Nitric Oxide 22, 205-212. crossref(new window)

Perales, S., Alejandre, M. J., Palomino-Morales, R., Torres, C., Iglesias, J. and Linares, A. 2009. Effect of oxysterol-induced apoptosis of vascular smooth muscle cells on experimental hypercholesterolemia. J. Biomed. Biotechnol. 2009, 456208.

Rusiñol, A. E., Thewke, D., Liu, J., Freeman, N., Panini, S. R. and Sinensky, M. S. 2004. AKT/protein kinase B regulation of BCL family members during oxysterol-induced apoptosis. J. Biol. Chem. 279, 1392-1399. crossref(new window)

Sampey, B. P., Carbone, D. L., Doorn, J. A., Drechsel, D. A. and Petersen, D. R. 2007. 4-Hydroxy-2-nonenal adduction of extracellular signal-regulated kinase (Erk) and the inhibition of hepatocyte Erk-Est-like protein-1-activating protein-1 signal transduction. Mol. Pharmacol. 71, 871-883.

Schroepfer, G. J. Jr. 2005. Oxysterols: modulators of cholesterol metabolism and other processes. Physiol. Rev. 80, 361-554.

Spiliopoulos, S., Diamantopoulos, A., Katsanos, K., Ravazoula, P., Karnabatidis, D. and Siablis, D. 2014. PolarCath cryoplasty enhances smooth muscle cell apoptosis in a rabbit iliac artery model: an experimental in vivo controlled study. Cryobiology 63, 267-272.

Suizu, F., Hiramuki, Y., Okumura, F., Matsuda, M., Okumura, A. J., Hirata, N., Narita, M., Kohno, T., Yokota, J., Bohgaki, M., Obuse, C., Hatakeyama, S., Obata, T. and Noguchi, M. 2009. The E3 ligase TTC3 facilitates ubiquitination and degradation of phosphorylated Akt. Dev. Cell 17, 800-810. crossref(new window)

Toné, S., Sugimoto, K., Tanda, K., Suda, T., Uehira, K., Kanouchi, H., Samejima, K., Minatogawa, Y. and Earnshaw, W. C. 2007. Three distinct stages of apoptotic nuclear condensation revealed by time-lapse imaging, biochemical and electron microscopy analysis of cell-free apoptosis. Exp. Cell Res. 313, 3635-3644. crossref(new window)

Tucka, J., Yu, H., Gray, K., Figg, N., Maguire, J., Lam, B., Bennett, M. and Littlewood, T. 2014. Akt1 regulates vascular smooth muscle cell apoptosis through FoxO3a and Apaf1 and protects against arterial remodeling and atherosclerosis. Arterioscler. Thromb. Vasc. Biol. 34, 2421-2428. crossref(new window)

Zhao, Y., Miriyala, S., Miao, L., Mitov, M., Schnell, D., Dhar, S. K., Cai, J., Klein, J. B., Sultana, R., Butterfield, D. A., Vore, M., Batinic-Haberle, I., Bondada, S. and St. Clair, D. K. 2014. Redox proteomic identification of HNE-bound mitochondrial proteins in cardiac tissues reveals a systemic effect on energy metabolism after doxorubicin treatment. Free Radic. Biol. Med. 72, 55-65. crossref(new window)