IL-8 gene induction by low shear stress: pharmacological evaluation of the role of signaling molecules.
Shear stress can modulate endothelial cell function by regulating gene expression. We have previously demonstrated that low shear stress (4.2 dyn/cm(2)) induces the expression of interleukin-8 (IL-8) gene in endothelial cells. The present study was undertaken to further investigate both the effects of shear stress on IL-8 expression and the mechanisms controlling IL-8 mRNA up-regulation in human umbilical vein endothelial cells (HUVEC). We show that shear stress (from 2.23 to 19.29 dyn/cm(2)) induces the IL-8 expression at both the mRNA and protein levels by stimulating transcription. In order to determine the possible contribution of G protein, HUVEC were pretreated with an inhibitor of G-protein activation, GDPbetaS, which abrogated the low shear stress-induced IL-8 gene expression. Such gene expression was also partially inhibited by the tyrosine kinase inhibitor (tyrphostin-25) and in addition by EGTA, BATPA/AM (the intracellular Ca(2+) chelator), Verapamil (a Ca(2+) channel blocker), cAMP-dependent protein kinase inhibitor (KT5720) and phospholipase C inhibitor (neomycin). However, the cGMP-dependent protein kinase inhibitor, KT5823, had no effect on such expression. These findings therefore demonstrate the involvement of several signaling molecules, including tyrosine kinase, G protein, calcium, phospholipase C, and cAMP-dependent protein kinase, in the low shear stress-induced IL-8 gene expression.
Cheng
Min
M
Laboratory of Cardiovascular Diseases, West China Hospital, Sichuan University, Chengdu, Sichuan, PR China.
Liu
Xiaoheng
X
Li
Yi
Y
Tang
Rong
R
Zhang
Wensheng
W
Wu
Jiang
J
Li
Liang
L
Liu
Xiaojing
X
Gang
Yang
Y
Chen
Huaiqing
H
D002118:Calcium / Q000502:physiology; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000502:physiology; D004730:Endothelium, Vascular / Q000166:cytology; D019204:GTP-Binding Proteins / Q000502:physiology; D005786:Gene Expression Regulation; D006801:Humans; D016209:Interleukin-8 / Q000096:biosynthesis / Q000235:genetics*; D040542:Mechanotransduction, Cellular / Q000235:genetics / Q000502:physiology*; D011494:Protein Kinases / Q000502:physiology; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D013314:Stress, Mechanical; D014158:Transcription, Genetic; D010738:Type C Phospholipases / Q000502:physiology
D016209:Interleukin-8; D012333:RNA, Messenger; D011494:Protein Kinases; D011505:Protein-Tyrosine Kinases; D010738:Type C Phospholipases; D019204:GTP-Binding Proteins; D002118:Calcium