Abstract: Objective To study the delaying denervated skeletal muscle atrophy after transplantation of mesenchymal progenitor cell (MPC) into the transected position. Methods MPC were isolated from bones of hind limbs of GFP transgenic C57 mice for cultivation and identification. 36 C57 mice were divided into 3 groups evenly in random, MPC transplantation group, the transected group and the control group. 5μL of MPC suspension and 5μL of Phosphate buffered saline (PBS) were injected into the sciatic nerve transected position in the MPC transplantation group and the transected group respectively while nothing was injected in the control group. The activity ability of hind limbs of mice were observed. At the time point of 2 and 4 weeks after the operation, the retain ratio of wet weight of gastrocnemius muscle and cross sectional area of muscle fiber was measured and the ultrastructural organization was observed. The expression of α-actin, myoglobulin (MHC) were detected by western blot and the expression of Myogenin and MyoD were detected by RT-PCR. Results At the time point of 2 and 4 weeks after the operation, the wet weight of gastrocnemius muscle and the retain ratio of cross sectional area of muscle fiber of mice of the MPC transplantation group was higher than that of the transected group significantly (P < 0.05). At the time point of 4 weeks after the operation，compared with the degeneration of myocyte, mitochondria and sarcoplasmic reticulum and the extent of musculus fibrosis of the transected group, that of the MPC transplantation group were lower significantly while compared with the the expression of α-actin, MHC, Myogenin and MyoD of the transected group, that of the MPC transplantation group were higher significantly(P < 0.05). Conclusion The transplantation in vivo of allogenic mesenchymal progenitor cells is effective for delaying denervated muscle atrophy.

Key words: Mesenchymal progenitor cells, muscular atrophy, denervation, Peripheral nerve