Hepatocyte growth factor regulates angiotensin converting enzyme expression.
Hepatocyte growth factor (HGF) is a mitogen, morphogen, and motogen that functions in tissue healing and acts as an anti-fibrotic factor. The mechanism for this is not well understood. Recent studies implicate somatic angiotensin-converting enzyme (ACE) in fibrosis. We examined the effects of HGF on ACE expression in bovine pulmonary artery endothelial cells (BPAEC). Short term treatment of BPAEC with HGF transiently increased both ACE mRNA (3 h) and activity (24 h), as determined by ACE protease assays and reverse transcription-PCR. Incubation of BPAEC with HGF for longer periods suppressed ACE mRNA (6 h) and activity (72 h). In contrast, phorbol ester (PMA) treatment produced sustained increase in ACE mRNA and activity. We examined the short term molecular effects of HGF on ACE using PMA for comparison. HGF and PMA increased transcription from a luciferase reporter with the core ACE promoter, which contains a composite binding site for SP1/3 and Egr-1. Immunocytochemistry and electrophoretic mobility shift assay showed that both HGF and PMA increased Egr-1 binding. HGF also increased SP3 binding, as measured by EMSA. However, HGF and PMA increased the cellular activity of only Egr-1, not SP3, as measured by luciferase reporter assays. Deletion of the Egr-1 site in the reporter construct completely abrogated HGF-induced transcription but only approximately 50% of PMA-induced activity. Expression of dominant negative Egr-1 and SP3 blocked up-regulation of the ACE promoter by HGF but only reduced up-regulation by PMA. These results show that HGF transiently increases gene transcription of ACE via activation of Egr-1, whereas PMA regulation involves Egr-1 and additional factor(s).
Day
Regina M
RM
New England Medical Center, Tupper Research Institute, Pulmonary and Critical Care Division, Boston, Massachusetts 02111, USA. reginamday@hotmail.com
Thiel
Gerald
G
Lum
Julie
J
Chévere
Rubén D
RD
Yang
Yongzhen
Y
Stevens
Joanne
J
Sibert
Laura
L
Fanburg
Barry L
BL
D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D004277:DNA, Single-Stranded / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004730:Endothelium, Vascular / Q000201:enzymology; D015971:Gene Expression Regulation, Enzymologic; D017228:Hepatocyte Growth Factor / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007703:Peptidyl-Dipeptidase A / Q000096:biosynthesis* / Q000235:genetics; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D051705:Sp3 Transcription Factor; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014162:Transfection
C400152:DNA enzyme ED5; D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; C497121:SP3 protein, human; D014157:Transcription Factors; D051705:Sp3 Transcription Factor; D017228:Hepatocyte Growth Factor; D007703:Peptidyl-Dipeptidase A