VITAMIN-E - A SENSOR AND AN INFORMATION TRANSDUCER OF THE CELL OXIDATION-STATE


AZZI A., BOSCOBOINIK D., MARILLEY D., OZER N. , STAUBLE B., TASINATO A.

AMERICAN JOURNAL OF CLINICAL NUTRITION, cilt.62, ss.1337-1346, 1995 (SCI İndekslerine Giren Dergi) identifier identifier identifier

  • Cilt numarası: 62 Konu: 6
  • Basım Tarihi: 1995
  • Doi Numarası: 10.1093/ajcn/62.6.1337s
  • Dergi Adı: AMERICAN JOURNAL OF CLINICAL NUTRITION
  • Sayfa Sayıları: ss.1337-1346

Özet

We studied the effects of RRR-alpha-tocopherol and RRR-beta-tocopherol in smooth muscle cells from rat (line A7r5) and human aortas. RRR-alpha-Tocopherol, but not RRR-beta-tocopherol, inhibited smooth muscle cell proliferation in a dose-dependent manner at concentrations in the range from 10 to 50 mu mol/L. RRR-beta-Tocopherol added simultaneously with RRR-alpha-tocopherol prevented growth inhibition. The earliest event brought about by RRR-alpha-tocopherol in the signal transduction cascade controlling receptor-mediated cell growth was the activation of the transcription factor AP-1. RRR-beta-tocopherol alone was without effect but in combination with RRR-alpha-tocopherol prevented the AP-1 activating effect of the latter. Protein kinase C was inhibited by RRR-alpha-tocopherol and not by RRR-beta-tocopherol, which also in this case prevented the effect of RRR-alpha-tocopherol. Calyculin A, a protein phosphatase inhibitor, prevented the effect of RRR-alpha-tocopherol on protein kinase C. The data can be rationalized by a model in which a tocopherol-binding protein discriminates between RRR-alpha-tocopherol and RRR-beta-tocopherol and initiates a cascade of events at the level of cell signal transduction that leads to the inhibition of cell proliferation.