Expression of human endothelin-converting enzyme isoforms: role of angiotensin II.
A key step in endothelin-1 (ET-1) synthesis is the proteolytic cleavage of big ET-1 by the endothelin-converting enzyme-1 (ECE-1). Four alternatively spliced isoforms, ECE-1a to ECE-1d, have been discovered; however, regulation of the expression of specific ECE-1 isoforms is not well understood. Therefore, we stimulated primary human umbilical vein endothelial cells (HUVECs) with angiotensin II (Ang II). Furthermore, expression of ECE-1 isoforms was determined in internal mammary arteries of patients undergoing coronary artery bypass grafting surgery. Patients had received one of 4 therapies: angiotensin-converting enzyme inhibitors (ACE-I), Ang II type 1 receptor blockers (ARB), HMG-CoA reductase inhibitors (statins), and a control group that had received neither ACE-I, ARB (that is, treatment not interfering in the renin-angiotensin system), nor statins. Under control conditions, ECE-1a is the dominant isoform in HUVECs (4.5+/-2.8 amol/microg RNA), followed by ECE-1c (2.7+/-1.0 amol/microg), ECE-1d (0.49+/-0.17 amol/microg), and ECE-1b (0.17+/-0.04 amol/microg). Stimulation with Ang II did not change the ECE-1 expression pattern or the ET-1 release. We found that ECE-1 mRNA expression was higher in patients treated with statins than in patients treated with ARB therapy (5.8+/-0.76 RU versus 3.0+/-0.4 RU), mainly attributed to ECE-1a. In addition, ECE-1a mRNA expression was higher in patients receiving ACE-I therapy than in patients receiving ARB therapy (1.68+/-0.27 RU versus 0.83+/-0.07 RU). We conclude that ECE-1a is the major ECE-1 isoform in primary human endothelial cells. Its expression in internal mammary arteries can be regulated by statin therapy and differs between patients with ACE-I and ARB therapy.
Department of Vascular Endothelium and Microcirculation, Medical Clinic and Policlinic III, University of Technology Dresden, Fetscherstr. 74, D-01307 Dresden, Germany.
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Goettsch
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A
Schubert
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H
Morawietz
D000368:Aged; D017398:Alternative Splicing; D000804:Angiotensin II / Q000378:metabolism* / Q000494:pharmacology; D047228:Angiotensin II Type 1 Receptor Blockers / Q000494:pharmacology; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology; D016282:Aspartic Acid Endopeptidases / Q000235:genetics*; D001483:Base Sequence; D002478:Cells, Cultured; D001026:Coronary Artery Bypass; D017931:DNA Primers / Q000235:genetics; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism; D019332:Endothelin-1 / Q000096:biosynthesis; D000072396:Endothelin-Converting Enzymes; D005260:Female; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006801:Humans; D007527:Isoenzymes / Q000235:genetics; D008297:Male; D008323:Mammary Arteries / Q000187:drug effects / Q000378:metabolism; D008666:Metalloendopeptidases / Q000235:genetics*; D008875:Middle Aged; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
D047228:Angiotensin II Type 1 Receptor Blockers; D000806:Angiotensin-Converting Enzyme Inhibitors; D017931:DNA Primers; D019332:Endothelin-1; D007527:Isoenzymes; D012333:RNA, Messenger; D000804:Angiotensin II; D016282:Aspartic Acid Endopeptidases; D008666:Metalloendopeptidases; C000606923:ECE1 protein, human; D000072396:Endothelin-Converting Enzymes