OBJECTIVE To investigate the effect of overexpression of vascular cell adhesion molecule-1(VCAM-1)on the migration in vitro of the murine mesenchymal stem cells(MSCs)and its possible mechanism. METHODS The migration ability of normal mouse MSC (C3) ,empty vector-transfected MSC(C3+N) and VCAM-1 transfected MSC(C3+VCAM-1)was assessed by Transwell culture system in vitro after incubation for 8 and 12 h,respectively. The fetal bovine serum (FBS) was used as the chemotactic agent to induce MSC migration. The transmigrated cells were detected with methylosaniliam chloride(crystal violet)as well as DAPI staining.Furthermore,the specific chemical inhibitors of mitogen-activation protein kinase (MAPK) pathway ( SB203580,PD98059 and JNK inhibitorⅡ)were added to the Transwell system for 12 h and the alteration of the MSC migration ability was evaluated. RESULTS After incubation with FBS for 8 and 12 h,the absolute migrated cell number(7467 ± 485 and 8795 ± 255)and migration rate〔(14.9 ± 1.0)% and(17.6 ± 0.5)%〕of MSC in C3+VCAM-1 group were significantly increased compared with C3 group〔2731±562 and 4779±224, (5.5 ± 1.1)%and(9.6 ± 0.4)%〕and C3+N group〔2539 ± 321 and 5645 ± 1080,(5.1 ± 0.6)%and(11.3 ± 1.1)%〕(P<0.05,P<0.01),but there was no significant difference between C3 and C3+N groups. Moreover,the MSC migration ability of C3+VCAM-1 group was partially suppressed by addition of JNK inhibitorⅡ. The transmigrated cell number(4843 ± 167)and migration rate〔(9.7 ± 0.3)%〕were decreased compared with those of C3+VCAM-1 group without JNK inhibitorⅡ(P<0.01). SB203580 and PD98059,as specific chemical inhibitors of MAPK pathway,had no effect on MSC migration. CONCLUSION VCAM-1 can enhance mouse MSC migration in vitro and th4e mechanism may be related to JNK/MAPK pathway activation.

Objective To investigate biomechanical characteristics of the modified memory alloy internal fixator for separation of pubic symphysis. Methods The model of pubic symphysis separation injury was established based on 10 pelvic specimens. The control group was fixed with the dynamic compression plate after reduction, and the experimental group was fixed with the modified memory alloy internal fixator for separation of pubic symphysis after reduction. The biomechanical stability for two kinds of internal fixation was compared. Results There were no loosening and fracture of internal fixation in both groups. The displacement of pubic symphysis in horizontal, anterio-posterior and vertical direction in the experimental group was obviously reduced compared with the control group (P＜0.05). Conclusions Compared with the dynamic compression plate, the modified memory alloy internal fixator for separation of pubic symphysis shows better resistance to the tensile force against horizontal and anterio-posterior direction, as well as better resistance to the vertical shear force.

Objective: To investigate the effects of Casein kinase 2-interacting protein 1 (CKIP-1) gene silencing on the proliferation of glioma cells U87-MG. Methods: The recombinant lentiviral vectors targeting CKIP-1 gene or negative control were constructed and then used to infect glioma U87-MG cell line.The effects of knock-down on the mRNA or protein expression of CKIP-1 were evaluated by real-time qPCR and western blotting.Cell cycle was detected by the flow cytometry assay, and cell proliferation changes were evaluated by cell counting, MTT, and BrdU assay, respectively.Lastly, the colony formation was used to investigate the effect of CKIP-1 knock-down on the clone formation. Results: Compared with the group of Ctrl, CKIP-1 siRNA was observed to significantly inhibit CKIP-1 expression at the mRNA levels (Ctrl (1.01±0.13) vs CKIP-1 siRNA (0.23±0.02), P<0.01) and protein levels in the U87-MG cells.Also, CKIP-1 suppression mediated by RNAi decreased the ratio of G0/G1 phase (Ctrl (69.64±0.79) vs CKIP-1 siRNA(62.64±0.66), P<0.01), increased that of G2/M phase (Ctrl (8.36±0.52) vs CKIP-1 siRNA(13.87±2.90), P<0.05), and significantly inhibited the cell proliferation and clone formation (Colony number: Ctrl (25±2) vs CKIP-1 siRNA(2±1), P<0.05) of transfected U87-MG cells. Conclusion Knocking down the expression of CKIP-1 significantly inhibit cell proliferation in human U87-MG glioma cells, indicating that CKIP-1 is involved in the development of gliomas and could promote the cell proliferation.