Targeted Deletion of CC Chemokine Receptor 2 Attenuates Left Ventricular Remodeling after Experimental Myocardial Infarction

• Published in: The American journal of pathology Vol. 165; no. 2; pp. 439 - 447
• Main Authors: Kaikita, Koichi, Hayasaki, Takanori, Okuma, Toshiyuki, Kuziel, William A., Ogawa, Hisao, Takeya, Motohiro
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Elsevier Inc 01-08-2004; ASIP; American Society for Investigative Pathology
• Subjects: Animals; Biological and medical sciences; Cardiology. Vascular system; Chemokine CCL2 - genetics; Chemokine CCL2 - physiology; Chromosome aberrations; Coronary heart disease; Echocardiography; Female; Gene Deletion; Heart; Investigative techniques, diagnostic techniques (general aspects); Macrophages - enzymology; Macrophages - pathology; Matrix Metalloproteinases - genetics; Matrix Metalloproteinases - metabolism; Medical genetics; Medical sciences; Mice; Mice, Knockout; Myocardial Infarction - etiology; Myocardial Infarction - metabolism; Myocardial Infarction - pathology; Myocarditis. Cardiomyopathies; Neutrophils - enzymology; Neutrophils - pathology; Pathology. Cytology. Biochemistry. Spectrometry. Miscellaneous investigative techniques; Receptors, CCR2; Receptors, Chemokine - genetics; Receptors, Chemokine - physiology; Regular; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - genetics; RNA, Messenger - metabolism; Tumor Necrosis Factor-alpha - genetics; Tumor Necrosis Factor-alpha - metabolism; Ventricular Remodeling - physiology; Myocardial infarction; Anatomic pathology; Target; Heart disease; Deletion; Cardiovascular disease; Experimental study; Remodeling; Myocardial disease; CC chemokine receptor; Left ventricle
• ISSN: 0002-9440; 1525-2191
• DOI: 10.1016/S0002-9440(10)63309-3

A key component of cardiac remodeling after acute myocardial infarction (MI) is the inflammatory response, which modulates cardiac tissue repair. The purpose of this study was to investigate the relationship between the monocytic inflammatory response and left ventricular remodeling after MI using mice deficient in CC chemokine receptor 2 (CCR2), the primary receptor for the critical regulator of CC chemokine ligand 2. Immunohistochemical analysis revealed rapid infiltration of macrophages into infarcted tissue within 7 days in wild-type (WT) mice. However, this process was greatly impaired in CCR2-deficient (CCR2
−/−) mice. Echocardiography demonstrated beneficial effects of CCR2 deficiency on left ventricular remodeling at 7 and 28 days after MI.
In situ
zymography showed augmented gelatinolytic activity in WT mice within 7 days after MI, whereas gelatinolytic activity was barely detectable in CCR2
−/− mice. Moreover, the distribution of gelatinolytic activity in serial sections was very similar to the distribution of macrophages rather than neutrophils. Expression of matrix metalloproteinases and tumor necrosis factor-α mRNAs was up-regulated in infarcted regions from WT mice compared to CCR2
−/− mice at 3 days after MI. Direct inhibition of CCR2 functional pathway might contribute to the attenuation of left ventricular remodeling after MI.