Signalling functions of alpha-tocopherol in smooth muscle cells

Azzi A., Boscoboinik D., Clement S., Ozer N., Ricciarelli R., Stocker A., ...More

INTERNATIONAL JOURNAL FOR VITAMIN AND NUTRITION RESEARCH, vol.67, no.5, pp.343-349, 1997 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 67 Issue: 5
  • Publication Date: 1997
  • Journal Name: INTERNATIONAL JOURNAL FOR VITAMIN AND NUTRITION RESEARCH
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.343-349
  • Keywords: alpha-tocopherol, vitamin E, protein kinase C, vascular smooth muscle cell, cell proliferation, protein phosphatase, oxidative stress, PROTEIN-KINASE-C, VITAMIN-E CONSUMPTION, CORONARY-DISEASE, CAROTID-ARTERY, PROLIFERATION, ATHEROSCLEROSIS, ANTIOXIDANT, RAT, PHOSPHORYLATION, PATHOGENESIS
  • Marmara University Affiliated: Yes

Abstract

alpha-Tocopherol but not beta-tocopherol, activates protein phosphatase 2A, decreases protein kinase C activity and attenuates smooth muscle cell proliferation at physiological concentrations. beta-Tocopherol prevents the effects of alpha-tocopherol. Inhibition of protein kinase C alpha but not of the other isoforms, by the inhibitor Go6976 prevents the effect of alpha-tocopherol. Protein kinase C alpha, immunoprecipitated from alpha-tocopherol treated cells, is less phosphorylated and inactive. It is proposed that the specific activation of protein phosphatase 2A by alpha-tocopherol results in dephosphorylation and inactivation of protein kinase C alpha. Finally, this cascade of events leads to smooth muscle cell proliferation inhibition.