alpha-tocopherol as a modulator of smooth muscle cell proliferation

Azzi A., Boscoboinik D., Clement S., Marilley D., Ozer N. , Ricciarelli A., ...Daha Fazla

PROSTAGLANDINS LEUKOTRIENES AND ESSENTIAL FATTY ACIDS, cilt.57, ss.507-514, 1997 (SCI İndekslerine Giren Dergi) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 57
  • Basım Tarihi: 1997
  • Doi Numarası: 10.1016/s0952-3278(97)90436-1
  • Sayfa Sayıları: ss.507-514


The effects of alpha-tocopherol and beta-tocopherol have been studied in rat and human aortic smooth muscle cells. alpha-tocopherol, but not beta-tocopherol, inhibited smooth muscle cell proliferation and protein kinase C in a dose-dependent manner, at concentrations ranging from 10 to 50 mu M. beta-tocopherol added simultaneously with alpha-tocopherol prevented both proliferation and protein kinase C inhibition. Protein kinase C inhibition was cell cycle-dependent and it was prevented by okadaic acid, a protein phosphatase inhibitor. Protein kinase C activity measured from aortas of cholesterol-fed rabbits was also inhibited by alpha-tocopherol. By using protein kinase C (PKC) isoform-specific inhibitors and immunoprecipitation reactions it was found that PKC-alpha was selectively inhibited by alpha-tocopherol. Further, an activation of protein phosphatase 2A by alpha-tocopherol was found, which caused PKC-alpha dephosphorylation and inhibition. Ultimately, this cascade of events at the level of cell signal transduction leads to the inhibition of smooth muscle cell proliferation.