ABSTRACT
Objective To study the feasibility of TNF-α promoting migration of rat mesenchymal stem cells (MSCs) to local damaged tissues. Methods The MSCs was exposed to TNF-α at different concentrations and the expression rate of surface adheslon molecules and specific markers as well as their adhesion to endothelial cells were detected.Based on the above steps,the MSCs stimulated with the optimal concentration of TNF-α were obtained and were injected intravenously to the rats whose hindlimbs experienced ischemia damage.The rats were executed for achieving the muscle samples in the ischemic area,which were made into frozen section to count the number of MSCs. Results ( 1 ) Twenty-four hours after the TNF-o stimulation,the expression of adhesion molecule (VCAM-1) of MSCs increased in a concentration-dependent manner,while the expression of adhesion molecules (ICAM-1,L-Selectin and VLA4) of MSCs showed no significant changes.Besides,the expression rate of specific markers of MSCs was also obscure.(2) Exposed to 10 ng/ml TNF-o,MSCs presented an obviously increased ability in adhesion to the endothelial cells.(3) MSCs stimulated with 10 ng/ml TNF-α showed a larger number in the ischemia-damaged tissue of rat hindlimbs than that in the control group. Conclusion TNF-α at concentration of 10 ng/ml is effective within a short term in increasing VCAM-1 expression in rat MSCs and promoting the adhesion of MSCs to endothelial cells without affecting their character.
ABSTRACT
BACKGROUND: Following bone marrow mesenchymal stem cells (BMMSCs) infusion therapy, which factor promotes BMMSCs migrated to correct position is a key point, currently, adhesion molecule is thought to be playing an important role in mediating BMMSCs migration. OBJECTIVE: To investigate the expression of vascular cell adhesion molecule 1 (VCAM-1) and intercellular adhesion molecule 1 (ICAM-1) in rat BMMSCs. METHODS: BMMSCs were in vitro separated from rat bone marrow by directly adherence method. The expression of VCAM-1 and ICAM-1 were identified by using immunocytochemical staining, and the expression rates of antigen were tested by flow cytometry, in addition, their mRNA expressions were measured by RT-PCR. RESULTS AND CONCLUSION: Immunocytochemistry demonstrated that BMMSCs weakly expressed VCAM-1, but strong expressed ICAM-1. Flow cytometry showed that the expression rate of VCAM-1 was 6%, and the expression rate of ICAM-1 was 100%. RT-PCR showed that BMMSCs expressed a low level of VCAM-1 mRNA but a high level of ICAM-1 mRNA. It revealed under physiological condition, BMMSCs expressed a low level of VCAM-1, whereas they expressed a high level of ICAM-1.