Arizona Health Sciences

Preserved heart function and maintained response to cardiac stresses in a genetic model of cardiomyocyte-targeted deficiency of cyclooxygenase-2.

TitlePreserved heart function and maintained response to cardiac stresses in a genetic model of cardiomyocyte-targeted deficiency of cyclooxygenase-2.
Publication TypeJournal Article
Year of Publication2010
AuthorsPapanicolaou KN, Streicher JM, Ishikawa T-O, Herschman H, Wang Y, Walsh K
JournalJ Mol Cell Cardiol
Volume49
Issue2
Pagination196-209
Date Published2010 Aug
ISSN1095-8584
KeywordsAnimals, Cardiomegaly, Cyclooxygenase 2, Gene Deletion, Heart, Heart Function Tests, Heart Ventricles, Integrases, Mice, Mice, Knockout, Models, Genetic, Myocardial Reperfusion Injury, Myocardium, Myocytes, Cardiac, Organ Specificity, Pressure, Recombination, Genetic, Stress, Physiological, Systole
Abstract

Cyclooxygenase-1 and -2 are rate-limiting enzymes in the formation of a wide array of bioactive lipid mediators collectively known as prostanoids (prostaglandins, prostacyclins, and thromboxanes). Evidence from clinical trials shows that selective inhibition of the second isoenzyme (cyclooxygenase-2, or Cox-2) is associated with increased risk for serious cardiovascular events and findings from animal-based studies have suggested protective roles of Cox-2 for the heart. To further characterize the function of Cox-2 in the heart, mice with loxP sites flanking exons 4 and 5 of Cox-2 were rendered knockout specifically in cardiac myocytes (Cox-2 CKO mice) via cre-mediated recombination. Baseline cardiac performance of CKO mice remained unchanged and closely resembled that of control mice. Furthermore, myocardial infarct size induced after in vivo ischemia/reperfusion (I/R) injury was comparable between CKO and control mice. In addition, cardiac hypertrophy and function four weeks after transverse aortic constriction (TAC) was found to be similar between the two groups. Assessment of Cox-2 expression in purified adult cardiac cells isolated after I/R and TAC suggests that the dominant source of Cox-2 is found in the non-myocyte fraction. In conclusion, our animal-based analyses together with the cell-based observations portray a limited role of cardiomyocyte-produced Cox-2 at baseline and in the context of ischemic or hemodynamic challenge.

DOI10.1016/j.yjmcc.2010.04.002
Alternate JournalJ. Mol. Cell. Cardiol.
PubMed ID20399788
PubMed Central IDPMC2891277
Grant ListR01 CA123055 / CA / NCI NIH HHS / United States
R37 AG015052-14 / AG / NIA NIH HHS / United States
R01 AG034972 / AG / NIA NIH HHS / United States
R37 AG015052 / AG / NIA NIH HHS / United States
R01 AG034972-01 / AG / NIA NIH HHS / United States
Faculty Member Reference: 
John M. Streicher, PhD