The Effect of Rhbmp-2/allograft Composite on the Regulation of Gene Expression Related to Rabbit Lumbar Spinal Fusion
|School||Xinjiang Medical University|
|Keywords||rhBMP-2 Lumbar spinal fusion allograft|
Objective: To investigate the endogenous correlative gene expression of the masses taken from the rabbits undergone posterolateral lumbar spinal fusion with rhBMP-2/ allograft composite.Methods: Sixty adult male New Zealand white rabbits were randomly divided into three groups:rhBMP-2/allograft composite group, autograft group and allograft group, and each group included 20 rabbits. The rabbits were undergone L5, L6 intertransverse process fusion using rhBMP-2/allograft composite, autogenous iliac crest bone graft and allograft. Every four rabbits from each group sacrificed at the 1st, 2nd, 3th, 4th, 5th week after operation, the fusion masses were harvested then, then determine BMP -2?BMP-7 and VEGF expression at the transcriptional level by real time RT-PCR and situ hybridization.Results: Situ hybridization results: at the 1st week, the BMP-7 expression of composite was higher than other two groups, while from the soncend week the autograft group was higher than the composite and the BMP-7 expression of these two groups was higher than the aiiograft. At the 4th week, the composite group (61.12±2.42)、autograft group (64.64±2.00) and allograft group (50.20±2.15) reached the highest level. At the 3th week, the VEGF expression of the composite (65.43±2.67), autograft groups (63.23±4.63) and allograft groups (45.69±2.61) reached the highest, at the 3th,4th ,5th week, there was not statistically significant between the composite and autograft. while the VEGF expression of these two groups was higher than the allograft. RT-PCR results: At the 3th week, the endogenous BMP-2 (5.3519±1.0384) and VEGF (0.9257±0.2534) gene transcription of the composite group reached the highest level which was higher in comparison to autograft and allograft groups (P<0.05), and then declined. After 4 weeks, endogenous BMP-2 of the composite still keep high expression, but VEGF level was not statistically significant compared to the other two groups (P>0.05). At the 3th, 4th, 5th week after operation, there was not statistically significant among the composite group and autograft group, But both were superior to the allograft group. The trend of BMP-7 expression change between Real-time PCR and situ hybridization was the same.At the 4th, there was statistically significant among the composite group (1.2115±0.4007), autograft group (1.7859±0.1033) and allograft group (1.1322±0.1233). At the 5th, BMP-7 expression of the three groups declined, while there was not statistically significant (P>0.05).Conclusion: The rhBMP-2/allograft composite could slowly、constantly and steadily release endogenous rhBMP-2 ,boost endogenous BMP-2 ? BMP-7and VEGF gene expression effectively and improve the bone formation and vascularization.