Bcl-xL expression improves the therapeutic effect of human umbilical cord stem cell transplantation on articular cartilage injury in rabbit.

BACKGROUND

To investigate the therapeutic effect of transplantation of B-cell lymphoma-extra large (Bcl-xL) gene modified human umbilical cord blood stem cells (HUCSCs) on rabbit articular cartilage injury.

MATERIALS AND METHODS

HUCSCs were isolated and identified. Lentiviral encoding Bcl-xL was applied to modify HUCSCs. The effects of Bcl-xL overexpression on apoptosis and related gene expression after differentiation induction of HUCSCs were detected. Additionally, the efficiency of transplantation of Bcl-xL gene modified HUCSCs on articular cartilage injury were evaluated.

RESULTS

HUCSCs could differentiate into chondrocytes after induction. Compared with control group, the apoptosis after induction was significantly elevated, but reduced by Bcl-xL gene overexpression. The differentiation of HUCSCs into chondrocytes was displayed by expression of type II collagen (CII), but accompanying with expression of caspase-3 and matrix metalloproteinase-3 (MMP-3). By contrast, Bcl-xL gene overexpression reduced caspase-3 and MMP-3 expression, but further increased CII expression. Pathological staining showed that Bcl-xL gene modified HUCSCs could obviously repair cartilage injury. Compared with sham control group, the expression of caspase-3 and MMP-3 in model group was significantly up-regulated, while the expression of CII was significantly down-regulated. Transplantation of HUCSCs could ameliorate the injury, while Bcl-xL modification could improve the therapeutic effect of transplantation of HUCSCs. Moreover, Bcl-xL modification could further decrease cartilage injury-induced expression of caspase-3 and MMP-3, and improve the expression of CII compared with transplantation of normal HUCSCs.

CONCLUSIONS

Bcl-xL gene modification decreases cell differentiation-induced apoptosis and improves the efficiency of HUCSCs transplantation in the repairing of cartilage injury.