BACKGROUNDCardiovascular complications of Kawasaki disease (KD) are a common cause of heart disease in pediatric populations. Previous studies have suggested a role for endothelial progenitor cells (EPCs) in coronary artery lesions associated with KD. However, long-term observations of EPCs during the natural progression of this disorder are lacking. Using an experimental model of KD, we aimed to determine whether the coronary artery lesions are associated with down-regulation of EPCs.

METHODSTo induce KD, C57BL/6 mice were administered an intraperitoneal injection of Lactobacillus casei cell wall extract (LCWE; phosphate buffered saline used as control vehicle). Study groups included: group A (14 days following LCWE injection), group B (56 days following LCWE injection) and group C (controls). Numbers of circulating EPCs (positively staining for both CD34 and Flk-1 while staining negative for CD45) were evaluated using flow cytometry. Bone marrow mononuclear cells were cultured in vitro to expand EPCs for functional analysis. In vitro EPC proliferation, adhesion and migration were assessed.

RESULTSThe model was shown to exhibit similar coronary artery lesions to KD patients with coronary aneurysms. Numbers of circulating EPCs decreased significantly in the KD models (groups A and B) compared to controls ((0.017 ± 0.008)% vs. (0.028 ± 0.007)%, P < 0.05 and (0.016 ± 0.007)% vs. (0.028 ± 0.007)%, P < 0.05). Proliferative, adhesive and migratory properties of EPCs were markedly impaired in groups A and B.

CONCLUSIONCoronary artery lesions in KD occur as a consequence of impaired vascular injury repair, resulting from excess consumption of EPCs together with a functional impairment of bone marrow EPCs and their precursors.

Animals ; Cell Adhesion ; physiology ; Cell Movement ; physiology ; Cell Proliferation ; Cells, Cultured ; Endothelial Cells ; cytology ; Flow Cytometry ; Male ; Mice ; Mice, Inbred C57BL ; Mucocutaneous Lymph Node Syndrome ; pathology ; Stem Cells ; cytology

BACKGROUNDCoronary artery damage from Kawasaki disease (KD) is closely linked to the dysfunction of endothelial progenitor cells (EPCs). The aim of the present study was to evaluate the therapeutic effect of EPCs transplantation in KD model.

METHODSLactobacillus casei cell wall extract (LCWE)-induced KD model in C57BL/6 mice was established. The model mice were injected intravenously with bone marrow-derived in vitro expanded EPCs. Histological evaluation, number of circulating EPCs and the function of bone marrow EPCs were examined at day 56.

RESULTSInflammation was found around the coronary artery of the model mice after 14 days, Elastin breakdown was observed after 56 days. CM-Dil labeled EPCs incorporated into vessel repairing foci was found. At day 56, the number of peripheral EPCs in the KD model group was lower than in EPCs transplanted and control group. The functional index of bone marrow EPCs from the KD model group decreased in proliferation, adhesion and migration. Increased number of circulating EPCs and improved function were observed on the EPCs transplanted group compared with model group.

CONCLUSIONExogenously administered EPCs, which represent a novel strategy could prevent the dysfunction of EPCs, accelerate the repair of coronary artery endothelium lesion and decrease the occurrence of aneurysm.

Animals ; Cell Adhesion ; physiology ; Cell Proliferation ; Disease Models, Animal ; Elastin ; metabolism ; Endothelial Cells ; cytology ; Male ; Mice ; Mucocutaneous Lymph Node Syndrome ; metabolism ; therapy ; Stem Cell Transplantation ; psychology ; Stem Cells ; cytology ; physiology