Submit a comment
Abstract
Endothelin-converting enzyme-1 and -2 (ECE-1 and -2) are membrane-bound metalloproteases that can cleave biologically the inactive endothelin-1 (ET-1) precursor to form active ET-1 in vitro. We previously reported developmental defects in specific subsets of neural crest–derived tissues, including branchial arch–derived craniofacial structures, aortic arch arteries, and the cardiac outflow tract in ECE-1 knockout mice. To examine the role of ECE-2 in cardiovascular development, we have now generated a null mutation in ECE-2 by homologous recombination. ECE-2 null mice develop normally, are healthy into adulthood, are fertile in both sexes, and live a normal life span. However, when they are bred into an ECE-1–null background, defects in cardiac outflow structures become more severe than those in ECE-1 single knockout embryos. In addition, ECE-1–/–; ECE-2–/– double null embryos exhibited abnormal atrioventricular valve formation, a phenotype never seen in ECE-1 single knockout embryos. In the developing mouse heart, ECE-2 mRNA is expressed in the endocardial cushion mesenchyme from embyronic day (E) 12.5, in contrast to the endocardial expression of ECE-1. Levels of mature ET-1 and ET-2 in whole ECE-1–/–; ECE-2–/– embryos at E12.5 do not differ appreciably from those of ECE-1–/– embryos. The significant residual ET-1/ET-2 in the ECE-1–/–; ECE-2–/– embryos indicates that proteases distinct from ECE-1 and ECE-2 can carry out ET-1 activation in vivo.
Authors
Hiromi Yanagisawa, Robert E. Hammer, James A. Richardson, Noriaki Emoto, S. Clay Williams, Shin-ichi Takeda, David E. Clouthier, Masashi Yanagisawa
Guidelines
The Editorial Board will only consider comments that are deemed relevant and of interest to readers. The Journal will not post data that have not been subjected to peer review; or a comment that is essentially a reiteration of another comment.
- Comments appear on the Journal’s website and are linked from the original article’s web page.
- Authors are notified by email if their comments are posted.
- The Journal reserves the right to edit comments for length and clarity.
- No appeals will be considered.
- Comments are not indexed in PubMed.
Specific requirements
- Maximum length, 400 words
- Entered as plain text or HTML
- Author’s name and email address, to be posted with the comment
- Declaration of all potential conflicts of interest (even if these are not ultimately posted); see the Journal’s conflict-of-interest policy
- Comments may not include figures
Copyright © 2025 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)