ABSTRACT
Objective To observe the effect of the injection of myoblast carrying human insulin-like growth factor-1(hIGF-1) on the expression of endogenous IGF-1 mRNA and IGF-1 level in mice skeletal muscle following injury.Methods Seventy two male C3H mice(20~30g,7~11w)were randomly divided into three groups(24 mice in each group) with four mice normal controls.Applied a falling hit from certain height at the medial calf of right lower limbs in three groups,the injured skeletal muscle model was successfully simulated.Three days following injury,the mice in group A and B were injected with 1?106 myoblasts either carried with or without hIGF-1 gene respectively and the mice in group C were injected with 100?l saline at the injured muscle.Three mice in each group were sacrificed randomly at day 2,5,10,15,20,30 after contusion.The expression level of mIGF-1 was assessed by immunohistochemical staining and real time PCR.Results mIGF-1 mRNA expression and mIGF-1 factor secretion were observed in all three groups;the amount of mIGF-1 mRNA expression and mIGF-1 secretion in group A were significant higher than that in group B and C.Conclusion Myoblast carrying hIGF-1 transplantation could promote endogenous IGF-1 secretion in injured skeletal muscle.
ABSTRACT
Objective To observe the survival of myoblasts carrying hIGF-1 gene transplanted into the mice, and the expression of hIGF-1 in the transplanted mice. Methods Eighty four male C3H mice(20～30g,7～11w)were divided into four groups: group A, B, C and D (20 mice each group), and the remaining four mice were used as normal control. At the middle of the right gastrocnemius muscle, the mice in group A and B were injected with 1?10~6 myoblasts either carried with or without hIGF-1 gene. Muscle contusion at the middle of the right gastrocnemius muscle of the mice in group C and D was produced. At day 3 following injury, they were injected with 1?10~6 myoblasts either carried with hIGF-1 gene (group C) or without hIGF-1 gene (group D). At the day 2, 5, 10, 20, 30 after injection, four mice of each group were sacrificed randomly. BrdU staining in all mice were performed to evaluate cells surviving, and the expression level of hIGF-1 in group A and C was assessed by immunohistochemical staining and real-time-PCR. Results The BrdU staining in both normal and injured mice transplanted with myoblast carried with or without hIGF-1 were positive. hIGF-1 was expressed and secreted in both group A and C. Conclusion The myoblast carrying hIGF-1 gene transplanted into normal or injured mice can survive for a certain period of time, and can secrete hIGF-1.