Abstract
BACKGROUND - We hypothesized that c-kit receptor function in the bone marrow is important for facilitating healing, leading to efficient cardiac repair after myocardial infarction (MI). METHODS AND RESULTS - We used Kit/Kit c-kit mutant mice and their wild-type littermates to assess the importance of c-kit function in cardiac remodeling after coronary ligation. We found that mutant mice developed 1.6-fold greater ventricular dilation (P=0.008) attributable to a 1.3-fold greater infarct expansion by day 14 after MI (P=0.01). The number of proliferating smooth muscle α-actin expressing cells was 1.8-fold lower in mutant mice at day 3 (P<0.01), resulting in a 1.6 to 1.8-fold reduction in total regional nonvascular smooth muscle α-actin expressing cells by both microscopy and flow cytometry (P<0.001 for both). This decrease was accompanied by a 1.4-fold reduction in the number of CD31 expressing blood vessels (P<0.05). Prior transplantation of wild-type bone marrow cells into mutant mice rescued the efficient establishment of vessel-rich repair tissue by inducing a 1.5-fold increase in nonvascular smooth muscle α-actin expressing cells and CD31 expressing blood vessels (P<0.05 for both). The increased recruitment of cells into the infarct region in the chimeric mice was associated with reduced infarct expansion (P<0.03) compared to wild-type levels. CONCLUSIONS - Bone marrow c-kit function critically impacts the myofibroblast repair response in infarcted hearts. Interventions that increase the infiltration of c-kit cells to the infarcted heart may potentiate this endogenous repair response, prevent infarct expansion, and improve the recovery of cardiac function after MI.
Original language | English (US) |
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Pages (from-to) | I77-I82 |
Journal | Circulation |
Volume | 116 |
Issue number | 11 SUPPL. 1 |
DOIs | |
State | Published - Sep 2007 |
Externally published | Yes |
Keywords
- Cardiac remodeling
- Myocardial infarction
- Myofibroblast
- c-Kit
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine
- Physiology (medical)