Disruption of Endothelial Cell Homeostasis Plays a Key Role in the Early Pathogenesis of Coronary Artery Abnormalities in Kawasaki Disease

Figure 1. (a) Cytotoxicity, expressed as relative fluorescence units (RFU), was measured in serum-free HUVECs incubated with PSL, IG, and PSL + IG (median ± SD, 6 independent experiments). (b) RFU values were measured in HUVECs stimulated with sera from 27 Kawasaki disease (KD) patients incubated with PSL, IG, and PSL + IG and those from 6 patients with bacterial infections (median ± SD). **P < 0.01 compared with untreated. (c) RFU values were compared between 19 KD patients without coronary artery abnormalities (CAA) and 8 KD patients with CAA (median ± SD). **P < 0.01.

Figure 2. Levels of high mobility group box protein 1 in supernatants of HUVECs stimulated with sera from 16 Kawasaki disease patients and incubated with PSL, IG, and PSL + IG, and of HUVECs stimulated with sera from 6 patients with bacterial infections (median ± SD). **P < 0.01 compared with untreated.

Figure 3. (a) Caspase-3/7, expressed as relative luminescence units (RLU), was measured in serum-free HUVECs incubated with PSL, IG and PSL + IG (median ± SD, 6 independent experiments). *P < 0.05 compared with serum-free HUVECs. (b) RLU values were measured in HUVECs stimulated with sera from 17 Kawasaki disease patients, and incubated with PSL, IG, and PSL + IG and in HUVECs stimulated with sera from 6 patients with bacterial infections (median ± SD). *P < 0.05, and **P < 0.01, compared with untreated.

Figure 4. (a–d) Immunofluorescence staining showing morphologically condensed and fragmented nuclei (green) in HUVECs stimulated with sera from Kawasaki disease patients and those incubated with PSL. (e–h) Cells incubated with IG or PSL + IG maintained a morphologically normal appearance, with reduced caspase 3/7 activity. Scale bar = 100 μm.

Figure 5. (a) Western blot analysis of Akt and pAkt in HUVECs stimulated with sera from Kawasaki disease (KD) patients and incubated with PSL, IG, and PSL + IG, and in HUVECs stimulated with sera from patients with bacterial infections. (b) Immunoblotting assay of the pAkt/Akt ratio in HUVECs stimulated with sera from 12 KD patients and incubated with PSL, IG and PSL + IG and in HUVECs stimulated with sera from 6 patients with bacterial infections (median ± SD). *P < 0.05, and **P < 0.01, compared with untreated. (c) The effects of PSL, IG and PSL + IG on the pAkt/Akt ratio in HUVECs stimulated with sera from 4 KD patients with CAA and 8 KD patients without CAA. *P < 0.05.