Impact on migration of SD rat bone marrow mesenchymal stem cells treated with different intensities of low intensity pulsed ultrasound / 中国介入影像与治疗学

ABSTRACT

Objective To investigate the impact of low intensity pulsed ultrasound (LIPUS) with different intensities on the migration of bone marrow mesenchymal stem cells (BMSCs) in vitro.Methods BMSCs were divided into control group,30 mW/cm2 group,60 mW/cm2 group and 90 mW/cm2 group.Control group was treated by sham LIPUS exposure,and the other three groups were treated by LIPUS with corresponding intensities.The impact of LIPUS on scratch healing was tested with scratch assay,and the interference of proliferation was eliminated with MTT assay.The migration of BMSCs were evaluated with transwell migration assay.The expression of F-actin was analyzed with fluorescein isothiocyanate (FITC) fluorescent coloration.Results 24 h and 48 h after LIPUS exposure,there were statistical differences of scratch area among groups (F=26.559,106.110,both P＜0.001),and the scratch area of control group was the largest ([0.93 ± 0.26)mm2 of 24 h after LIPUS exposure and [0.70 ± 0.11]mm2 of 48 h after LIPUS exposure),while that of 30 mW/cm2 group was the smallest ([0.47 ±0.21]mm2 of 24 h after LIPUS exposure and [0.19±0.10]mm2 of 48 h after LIPUS exposure).There was no statistical difference of scratch area among the four groups immediately after LIPUS exposure (F=2.921,P=0.063).MTT assay results showed there was no statistical difference of absorbance among the four groups immediately,nor 24 h,48 h after LIPUS exposure (F=1.616,0.720,1.408;P=0.196,0.544,0.378).Significant difference was found in the number of cells migrated through the transwell chamber among the four groups (F=43.145,P＜0.001),and the cell number of 30 mW/cm2 group was the largest (212.53±35.32),while that of the control group was the least (89.53±19.27).F-actin fluorescence staining results showed the morphology of F-actin was changed after LIPUS exposure.The cytoskeleton became narrow and elongated.Statistical difference of relative fluorescence intensity was found among the four groups (F 64.350,P＜0.001).The relative fluorescence intensity of 30 mW/cm2 group was the largest (125.43 ± 17.43),while that of control group was the least (51.94± 12.76).Conclusion LIPUS can promote the migration ability of BMSCs in vitro with the best intensity was 30 mW/cm2.