Apoptosis

, 14:66

Isoflavone genistein protects human vascular endothelial cells against tumor necrosis factor-α-induced apoptosis through the p38β mitogen-activated protein kinase

Original Paper

DOI: 10.1007/s10495-008-0283-9

Cite this article as:
Si, H. & Liu, D. Apoptosis (2009) 14: 66. doi:10.1007/s10495-008-0283-9

Abstract

Isoflavone genistein may have beneficial effects on vascular function, but the mechanism is unclear. Here, we investigated whether genistein protects vascular endothelial cells against apoptosis induced by tumor necrosis factor-α. We show that genistein significantly inhibited TNF-α-induced apoptosis in human aortic endothelial cells as determined by caspase-3 activation, 7-amino actinomycin D staining, in situ apoptotic cell detection and DNA laddering. The anti-apoptotic effect of genistein was associated with an enhanced expression of Bcl-2 protein and its promoter activity. Inhibition of extracellular signal-regulated kinase 1/2, protein kinase A, or estrogen receptors had no effect on the cytoprotective effect of genistein. However, inhibition of p38 mitogen-activated protein kinase (p38) completely abolished this genistein effect. Accordingly, stimulation of HAECs with genistein resulted in rapid activation of p38β, but not p38α. These findings provide the evidence that genistein acts as a survival factor for vascular ECs to protect cells against apoptosis via activation of p38β. Preservation of the functional integrity of the endothelial monolayer may represent an important mechanism by which genistein exerts its vasculoprotective effect.

Keywords

GenisteinEndothelial cellsApoptosisp38

Abbreviations

7-AAD

7-Amino actinomycin D

CREB

cAMP-Responsive element binding protein

DMSO

Dimethylsulfoxide

ECs

Endothelial cells

ERs

Estrogen receptors

ERK1/2

Extracellular signal-regulated kinase 1/2

FBS

Fetal bovine serum

HAECs

Human aortic endothelial cells

LDL

Low density lipoprotein

p38

p38 Mitogen-activated protein kinase

p38α

p38 Mitogen-activated protein kinase alpha

p38β

p38 Mitogen-activated protein kinase beta

PBS

Phosphate-buffered saline

PKA

Protein kinase A

PTK

Protein tyrosine kinase

TNF-α

Tumor necrosis factor-alpha

TUNEL

Terminal deoxynucleotidyltransferase dUTP nick-end labeling

Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  1. 1.Department of Human Nutrition, Foods and Exercise, College of Agriculture and Life SciencesVirginia Polytechnic Institute and State UniversityBlacksburgUSA