Ultrasonic microbubbles promote mesenchymal stem cell homing to the fibrotic liver via upregulation of CXCR4 expression

Objective To investigate the mechanism of ultrasound microbubbles (UTMB) promoting stem cells homing to fibrotic liver. Methods Bone marrow derived mesenchymal stem cells (BMSCs) were divided into 5 groups with or without ultrasound microbubbles and continuously irradiated with ultrasound conditions of frequency 1 MHZ and output power 0.6 W/cm 2 for different times, and then injected into a mouse model of liver fibrosis through the tail vein with or without ultrasound microbubbles, with sound intensity. The effect of ultrasound microbubbles on MSC expression of CXC chemokine receptor 4 (CXCR4) and homing fibrotic liver was evaluated by flow cytometry (FCM), western blot (WB) and immunohistochemistry (IHC) analysis. Results The level of CXCR4 expression was significantly higher in the ultrasound microbubble group than in the non-intervention group (P < 0.05), and the number of MSC and the rate of CXCR4 receptor positivity in the ultrasound microbubble-treated liver tissues were significantly higher than in the non-intervention group (P < 0.01). Conclusion Ultrasonic microbubbles can promote the expression of CXCR4 on the surface of MSCs, thus improving the homing rate of MSCs in fibrotic liver.