TY - JOUR
T1 - CC chemokine receptor 5 deletion impairs macrophage activation and induces adverse remodeling following myocardial infarction
AU - Zamilpa, Rogelio
AU - Kanakia, Rushit
AU - Cigarroa, Joaquin
AU - Dai, Qiuxia
AU - Escobar, G. Patricia
AU - Martinez, Hernan
AU - Jimenez, Fabio
AU - Ahuja, Seema S.
AU - Lindsey, Merry L.
PY - 2011/4
Y1 - 2011/4
N2 - Post-myocardial infarction (MI), chemokine homing of inflammatory cells into the injured left ventricle (LV) regulates ventricular remodeling, in part by stimulating the extracellular matrix response. The CC chemokine receptor 5 (CCR5) is a key chemokine receptor expressed on macrophages, and CCR5 ligands are highly upregulated post-MI. We hypothesized that deletion of CCR5 would attenuate adverse remodeling by decreasing inflammatory cell recruitment. Accordingly, we examined LV function, macrophage recruitment and activation, and collagen content in wild-type (WT, n = 25) and CCR5 null (n = 33) mice at 7 days post-MI. Both groups had similar infarct sizes (44 ± 2% in WT and 42 ± 2% in CCR5 null; P =0.37). However, the LV remodeling index (end diastolic volume/LV mass) increased to a larger extent in CCR5 null (1.28 ± 0.08 μl/mg for CCR5 null and 1.02 ± 0.06 μl/mg for WT; P < 0.05). Although numbers of infiltrated macrophages were similar in WT and CCR5 null mice, CCR5-deficient macrophages isolated from the infarct zone displayed >50% decrease in gene expression levels of proinflammatory activation markers (interleukin 1β, interleukin-6, and tumor necrosis factor α), as well as anti-inflammatory activation markers (arginase 1, CD163, mannose receptor, and transforming growth factor- β 1) compared with WT (all P <0.05). Concomitant with the reduced macrophage activation, heat shock protein-47 and collagen type I precursor levels in the infarct region decreased in the CCR5 null (1.2 ± 0.3 units in the CCR5 null and 2.3 ± 0.4 units in the WT; P < 0.05), while collagen fragments increased (88.3 ± 5.9 units in the CCR5 null and 32.7 ± 8.5 units in the WT; P < 0.05). We conclude that CCR5 deletion impairs LV remodeling by hindering macrophage activation, which stimulates an imbalance in collagen metabolism and increases the remodeling index.
AB - Post-myocardial infarction (MI), chemokine homing of inflammatory cells into the injured left ventricle (LV) regulates ventricular remodeling, in part by stimulating the extracellular matrix response. The CC chemokine receptor 5 (CCR5) is a key chemokine receptor expressed on macrophages, and CCR5 ligands are highly upregulated post-MI. We hypothesized that deletion of CCR5 would attenuate adverse remodeling by decreasing inflammatory cell recruitment. Accordingly, we examined LV function, macrophage recruitment and activation, and collagen content in wild-type (WT, n = 25) and CCR5 null (n = 33) mice at 7 days post-MI. Both groups had similar infarct sizes (44 ± 2% in WT and 42 ± 2% in CCR5 null; P =0.37). However, the LV remodeling index (end diastolic volume/LV mass) increased to a larger extent in CCR5 null (1.28 ± 0.08 μl/mg for CCR5 null and 1.02 ± 0.06 μl/mg for WT; P < 0.05). Although numbers of infiltrated macrophages were similar in WT and CCR5 null mice, CCR5-deficient macrophages isolated from the infarct zone displayed >50% decrease in gene expression levels of proinflammatory activation markers (interleukin 1β, interleukin-6, and tumor necrosis factor α), as well as anti-inflammatory activation markers (arginase 1, CD163, mannose receptor, and transforming growth factor- β 1) compared with WT (all P <0.05). Concomitant with the reduced macrophage activation, heat shock protein-47 and collagen type I precursor levels in the infarct region decreased in the CCR5 null (1.2 ± 0.3 units in the CCR5 null and 2.3 ± 0.4 units in the WT; P < 0.05), while collagen fragments increased (88.3 ± 5.9 units in the CCR5 null and 32.7 ± 8.5 units in the WT; P < 0.05). We conclude that CCR5 deletion impairs LV remodeling by hindering macrophage activation, which stimulates an imbalance in collagen metabolism and increases the remodeling index.
KW - CC chemokines
KW - Inflammation
KW - Matrix metalloproteinases
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U2 - 10.1152/ajpheart.01002.2010
DO - 10.1152/ajpheart.01002.2010
M3 - Article
C2 - 21297029
AN - SCOPUS:79955072906
SN - 0363-6135
VL - 300
SP - H1418-H1426
JO - American Journal of Physiology - Heart and Circulatory Physiology
JF - American Journal of Physiology - Heart and Circulatory Physiology
IS - 4
ER -