Integrins alpha4 and alpha M, collagen1A1, and matrix metalloproteinase 7 are upregulated in acute Kawasaki disease vasculopathy

BACKGROUND: Kawasaki Disease (KD) can result in fatal coronary artery aneurysms especially in untreated patients. Our recent studies of KD vascular pathology revealed subacute/chronic vasculitis that began early in the illness with proliferation of smooth muscle cell derived-myofibroblasts in a complex extracellular matrix (ECM). We hypothesized that there is dysregulation of specific ECM and adhesion molecules in KD coronary arteries. METHODS: Gene expression profiling for ECM and adhesion molecules was performed on 6 acute KD and 8 control coronary arteries using a targeted real-time PCR array approach. RESULTS: Integrins alpha4 and alphaM (ITGA4, ITGAM), collagen 1A1 (COL1A1), and matrix metalloproteinase 7 (MMP-7) were significantly upregulated in KD coronary arteries compared with controls. Immunohistochemistry with anti- ITGAM antibodies revealed expression on inflammatory cells within the coronary artery wall in KD patients but not controls. CONCLUSION: Integrins ITGA4 and ITGAM are upregulated in KD vasculopathy, likely promoting inflammatory recruitment that stimulates smooth muscle cell transition to myofibroblasts and their proliferation. MMP-7 likely enhances myofibroblast proliferation and luminal lesion expansion, and overexpression of COL1A1 may lead to coronary artery stenosis. Identification of the molecular pathogenesis of KD vasculopathy may lead to the development of circulating biomarkers and to directed therapeutic interventions.