Effects of Umbilical Cord Blood Stem Cells on Coronary Artery Damage in Mice with Kawasaki Disease By High-Frequency Ultrasound

Abstract

Objective: to use lactobacillus casein cell wall extract (LCWE) to induce Kawasaki disease (KD) mouse model, and analyse the process of coronary artery damage and effects of umbilical cord blood stem cells by high-frequency ultrasound in small animals. Methods: LCWE was prepared and 18 BALB/c pups were randomly divided into two groups: 15 in KD model group and 3 in the normal control group. KD model was induced by a single intraperitoneal injection of 0.5ml LCWE in the model group, and changes of the coronary artery were observed at 2d, 21d and 30d after the injection, respectively. From the 16th day of modeling, 300 μL PBS was injected intraperitoneally daily in the control group and model group. The hUC-MSCs 300 μL (105/mL) were intraperitoneally injected daily for 10 consecutive days in the stem cell group. The mice were sacrificed in batches on day 2, 15, 21 and 30, and the morphological changes of coronary arteries were observed by echocardiography and histopathology. Results: the change of coronary artery diameter could be accurately measured by high-frequency small animal ultrasound. At 21d, the coronary arteries of the model group were widened compared with those of the control group. At 30d, there was no significant difference between the model group and the previous model group. Histopathology showed slight swelling of the epicardium of aortic valve, mitral valve, right ventricle and atrium, scattered infiltration of a few neutrophils, dilatation of the coronary artery lumen, necrosis and disintegration of a small number of myocardial cells, and significant hyperplasia of local fibrous connective tissue accompanied by solid calcium salt deposits. After hUC-MSCs intervention treatment, B-ultrasound showed a decrease in the main coronary artery diameter, histopathology showed multiple lymphocytes, eosinophilic granulocytes, and mononuclear cell infiltration in the left atrial appendage of mice, and no obvious vascular inflammatory reaction or other obvious abnormalities were observed. Conclusion: high-frequency ultrasound can be used to clearly obtain the coronary artery image of KD mice and dynamically observe the evolution process of coronary artery diameter, which provides more diagnostic basis for the treatment of clinical KD. And hUC-MSCs intervention reduced the pathological lesion of coronary artery inflammation in mice compared with the model group.