Estrogen has been reported to inhibit apoptosis in vascular endothelial cells. However, its precise mechanism still remains to be elucidated. Here we determined the role of Akt in the anti-apoptotic effect of estrogen. 17β-Estradiol prevented the apoptosis induced by TNF-α in bovine aortic endothelial cells, as evaluated by double staining with fluorescein isothiocyanate-conjugated annexin V and propidium iodide. Introducing a dominant negative mutant of Akt by using a cell-penetrating peptide of Tat protein inhibited the anti-apoptotic effect of estrogen in a concentration-dependent manner, and resulted in the complete inhibition of the anti-apoptotic effect of 17β-estradiol at 1 nM and higher concentrations. The dominant negative mutant without the cell-penetrating peptide and Tat peptide-conjugated protein A had no effect. The intracellular protein transduction was confirmed by immunoblot analysis. Our observations thus provide first direct evidence that Akt plays a central role in the anti-apoptotic effect of estrogen in vascular endothelial cells.
|Number of pages||5|
|Journal||Biochemical and Biophysical Research Communications|
|Publication status||Published - Nov 5 2004|
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Cell Biology