Development of murine ischemic cardiomyopathy is associated with a transient inflammatory reaction and depends on reactive oxygen species.
We examined the effects of daily repetitive brief (15 min) myocardial ischemia and reperfusion (I/R) in WT C57BL6 and extracellular superoxide dismutase (EC-SOD)-overexpressing mice. In the absence of myocardial necrosis, I/R resulted in persistent fibrosis in ischemic areas of C57/BL6 mice associated with persistent global and segmental anterior wall dysfunction. The I/R protocol induced chemokines (peak 3 days) followed sequentially by infiltration of macrophages and myofibroblasts (5 days). Fibrosis peaked at 7 days and was stable at 28 days despite regression of the chemokine and cellular response. Discontinuation of I/R at 7 or 28 days led to regression of fibrosis and ventricular dysfunction. In contrast, the EC-SOD mice developed markedly less chemokine induction, cell response, and fibrosis, with no ventricular dysfunction. Reversible fibrosis and ventricular dysfunction are features of human hibernating myocardium. The reduction of the cellular and functional response in EC-SOD mice suggests a role for reactive O(2) in the pathogenesis of ischemic cardiomyopathy.
Dewald
Oliver
O
Cardiovascular Sciences and DeBakey Heart Center, Baylor College of Medicine, and The Methodist Hospital, One Baylor Plaza, M.S. F-602, Houston, TX 77030, USA.
Frangogiannis
Nikolaos G
NG
Zoerlein
Martin
M
Duerr
Georg D
GD
Klemm
Christina
C
Knuefermann
Pascal
P
Taffet
George
G
Michael
Lloyd H
LH
Crapo
James D
JD
Welz
Armin
A
Entman
Mark L
ML
D000818:Animals; D001835:Body Weight; D009202:Cardiomyopathies / Q000209:etiology / Q000276:immunology*; D004452:Echocardiography; D005355:Fibrosis / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D007249:Inflammation; D007511:Ischemia; D008264:Macrophages / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D009206:Myocardium / Q000473:pathology; D010100:Oxygen / Q000378:metabolism; D012313:RNA / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D017382:Reactive Oxygen Species; D015427:Reperfusion Injury; D013482:Superoxide Dismutase / Q000378:metabolism; D013997:Time Factors
D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D012313:RNA; D013482:Superoxide Dismutase; D010100:Oxygen