The Experiment Study On Effect Of The Role Of SDF-1/CXCR4 On Human Bone Marrow Mesenchymal Stem Cells Homing To Damaged Liver

Objective:To explore the role of SDF-1/CXCR4 on human mesenchymal stem cells(MSCs)homing to damaged liver in vitro.Methods:MSCs were isolated from the bone marrow of healthy donors and amplified with cell culture technique,then they were stimulated with TNF-α,IL-6,IL-1β,LPS,cytokine cocktail(TNF-α,IL-6 and IL-1β),plasma from normal people and plasma from Patients with liver failure respectively,DMEM-DL as the control,48 hours later,cell-surface expression of CXCR4 was assessed by FCM,cells from each group were collected for chemotaxis assay,toward SDF-1,cell culture supemates were used for the quantitative determination of SDF-1 with ELISA,24 hours later, semi-quantitative RT-PCR technique was used to determine the SDF-1 expression at mRNA level,Real-time RT-PCR tests were used for CXCR4 mRNA expression.All data were presented as means±SEM,statistical analysis was performed using ANOVA with statistical software SPSS 13.0.Results:After primary culture of 12-16 days,MSCs can be passaged and in fusiform shape under light microscope,MSCs surface expression of CXCR4 levels were significantly increased in the groups stimulated with LPS,cytokine cocktail and plasma from patients with liver failure,IL-1βand IL-6 also increased the CXCR4 expression on MSCs surface.Although TNF-αhad no significant effect on increasing the CXCR4 expression on MSCs surface,chemotaxis assay showed that each group increased the migratory response of MSCs to SDF-1 except the normal plasma group. ELISA analysis showed that MSCs itself can secrete high levels of SDF-1,48 hours later,groups of IL-1β,cocktail,normal plasma and plasma from severe hepatitis had a increase SDF-1 level in contrast to control group,of which,IL-1βgroup increased the most obviously,TNF-αgroup had a significantly decreased level.24 hours later, RT-PCR analysis showed that the upper four groups also stimulated the SDF-1 mRNA expression while TNF-αgroup had a down regulation;Real-time RT-PCR showed in addition to normal plasma group,all groups increased CXCR4 gene expression significantly,of which,LPS group and plasma from severe hepatitis increased the most notable.Conclusion:In the process of repairing liver damage,with the interact of a variety of cytokines and inflammatory mediators such as TNF-α,IL-6,IL-1βand LPS,the interaction of SDF-1 and CXCR4 play a very important role in homing MSCs to injured liver.