Regulation Of CXCR4/CXCR7 By SDF-1 Stimulation In MSCs And The Relationship With PI3K/NF-κB Signal Pathway

Objective: To investigate the expression of CXCR4/CXCR7 in MSCs induced by SDF-1 and the relationship with PI3K/NF-κB signal pathways, providing experimental basis for further study in vitro.Methods:(1) Using whole bone marrow adherent isolation and cultivation for MSCs.(2) RT-PCR and Western Blot were performed to detect the changes of CXCR4 and CXCR7 expression after treatment of MSCs with different concentrations of SDF-1.(3) Wortmanin and PDTC were used to observe the role of PI3 K and NF-κB in SDF-1-induced CXCR4/CXCR7 up-regulation, respectively.(4)Western Blot assay was used to detect the signal transduction mechanism of MSCs induced by SDF-1 through observing the phosphorylation of Akt andIΚBα.Results:(1) MSCs after inoculation for 24-48 h, showed circular, spindle, polygonal shape. At the third passage, MSCs formed a topic uniform spindle shape.(2)RT-PCR and Western Blot demonstrated that both CXCR4 and CXCR7 were expressed in MSCs. The expression of CXCR4 and CXCR7 were increased by SDF-1 stimulation(P<0.01).(3)Compared to SDF-1 group, the combination of SDF-1 with Wortmanin, PDTC, AMD3100 and CCX733 largely restrained the up-regulation of CXCR4 and CXCR7 induced by SDF-1, both at protein and mRNA levels.(P<0.01)( 4) Further study indicated that the level of Akt phosphorylation significantly decreased in above stated combination groups.Conclusions:(1) SDF-1 stimulation on MSCs in a dose-dependent manner can express CXCR4, CXCR7 enhancement.(2) The activation of PI3K/NF-κB signaling pathways involved the process of CXCR4 and CXCR7 up-regulation by SDF-1 stimulation.