Effect of endothelin-1 (1-31) on extracellular signal-regulated kinase and proliferation of human coronary artery smooth muscle cells.
1. We have previously found that human chymase cleaves big endothelins (ETs) at the Tyr31-Gly32 bond and produces 31-amino acid ETs (1-31), without any further degradation products. In this study, we investigated the effect of synthetic ET-1 (1-31) on the proliferation of cultured human coronary artery smooth muscle cells (HCASMCs). 2. ET-1 (1-31) increased [3H]-thymidine incorporation and cell numbers to a similar extent as ET-1 at 100 nM. This ET-1 (1-31)-induced [3H]-thymidine uptake was not affected by phosphoramidon, an inhibitor of ET-converting enzyme. It was, however, inhibited by BQ123, an endothelin ET(A) receptor antagonist, but not by BQ788, an endothelin ET(B) receptor antagonist. 3. By using an in-gel kinase assay, we demonstrated that ET-1 (1-31) activated extracellular signal-regulated kinase 1/2 (ERK1/2) in a concentration-dependent manner (100 pM to 1 microM) in HCASMCs. ET-1 (1-31)-induced ERK1/2 activation was inhibited by BQ123, but not by BQ788 and phosphoramidon. Inhibition of protein kinase C (PKC) and ERK kinase also caused a reduction of ET-1 (1-31)-induced ERK1/2 activation, whereas tyrosine kinase inhibition had little effect. 4. Gel-mobility shift analysis revealed that the ERK1/2 activation was followed by an increase in transcription factor activator protein-1 DNA binding activity in HCASMCs. 5. Our results strongly suggest that ET-1 (1-31) itself stimulates HCASMC proliferation probably through endothelin ET(A) or ET(A)-like receptors. The underlining mechanism of cell growth by ET-1 (1-31) may be explained in part by PKC-dependent ERK1/2 activation. Since human chymase has been proposed to play a role in atherosclerosis, ET-1 (1-31) may be one of the mediators.
Yoshizumi
M
M
Department of Pharmacology, The University of Tokushima School of Medicine, Japan.
Kim
S
S
Kagami
S
S
Hamaguchi
A
A
Tsuchiya
K
K
Houchi
H
H
Iwao
H
H
Kido
H
H
Tamaki
T
T
D001158:Arteries; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000378:metabolism; D019332:Endothelin-1 / Q000031:analogs & derivatives; D016232:Endothelins / Q000494:pharmacology*; D004789:Enzyme Activation; D006321:Heart / Q000187:drug effects; D006801:Humans; D048369:MAP Kinase Kinase 1; D020929:Mitogen-Activated Protein Kinase Kinases; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D010446:Peptide Fragments / Q000494:pharmacology*; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D013997:Time Factors; D018808:Transcription Factor AP-1 / Q000378:metabolism
D004268:DNA-Binding Proteins; D019332:Endothelin-1; D016232:Endothelins; D010446:Peptide Fragments; D018808:Transcription Factor AP-1; C114932:endothelin-1 (1-31); D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; D011493:Protein Kinase C; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D048369:MAP Kinase Kinase 1; C482125:MAP2K1 protein, human; D020929:Mitogen-Activated Protein Kinase Kinases