Abstract: Objective To investigate the effect of insulin-like growth factor 1 ( IGF1) genetransfected bone marrow mesenchymal stem cells (BMSCs) on fracture healing and angiogenesis inrats. Methods The rat femoral fracture model was established, and the BMSCs with or withoutIGF1 gene transfection were used to treat the rats. X-ray imaging system and micro-CT scanner wereused to observe the fracture healing. HE staining was used to observe the histopathological changes offemur. Immunofluorescence staining was used to observe the expression of vascular endothelial marker CD31. Western blotting was used to detect the expression levels of bone morphogenetic protein 2( BMP-2 ), osteopontin ( OPN ), osteocalcin ( OCN ), vascular endothelial growth factor(VEGF) and angiopoietin-1 ( Ang-1). Results When compared with those in the model group,the fracture lines of the rats in the BMSC group and the IGF1-BMSC group were blurred and the formation of healing callus was observed, the values of BMD and BV / TV were increased (P < 0. 05), the value of Tb. N was increased (P < 0. 05), the value of Tb. Sp was decreased (P < 0. 05), theCD31 fluorescence expression was enhanced, the relative protein expression levels of BMP-2,OPN, OCN, VEGF and Ang-1 were all up-regulated ( P < 0. 05). When compared with those inthe BMSC group, the fracture line of rats in the IGF1-BMSC group was almost disappeared, andthe healing effect was better, the values of BMD and BV / TV were increased (P < 0. 05), the value of Tb. N was increased (P < 0. 05), the value of Tb. Sp was decreased (P < 0. 05), and CD31 fluorescence expression was stronger in the IGF1-BMSC group, the relative protein expression levelsof BMP-2, OPN, OCN, VEGF and Ang-1 were further up-regulated ( P < 0. 05). Conclusion IGF1 gene transfection with BMSC can effectively promote femoral fracture healing and acceleratevascular formation in rats, and the effect is better than that of BMSC alone.

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