Experimental Study On Reversing The Degeneration Of Intervertebral Disc Part Ⅳ: An In Vivo Study Of Adenovirus-Mediated Transfer Of The Human Transforming Growth Factor β1 (hTGF-β1) Encoding Gene To The Rabbit Intervertebral Disc

Objectives: 1)To deliver an exogenous therapeutic gene-hTGF-0 1 to rabbit lumbar intervertebral disc in vivo by Adenovirus vector . 2) To observe the expression of the exogenous therapeutic gene and to determine the effect on the biologic activity of the discs of the experimental rabbits.Material and methods: 1) 20 u 1 of 0.01M PBS, with or without adenovirus (6xl06pfu) carrying TGF- 0 1 gene ( Ad/CMV-hTGF-31) which were constructed by our laboratory , was injected directly into nucleus pulposus tissues of lumber discs of 30 skeletally mature New Zealand white rabbits . 2) Immunohistochemical staining for human transforming growth factor 3 1 was performed on the rabbit disc tissues in 4 days, 1 week, 2 weeks, 4 weeks after operation. A half-quantitation for immunohistochemical staining was performed by VIDAS analysis system. 3) The proteoglycan of lumber discs was quantitated in different duration .Result: Discs injected with Ad/CMV-hTGF- 0 1 exhibited extensive and intense positive immunohistochemical staining for transforming growth factor 0 1 from 1 week to 4 weeks after operation, and positive pellets in nucleus pulposus cells in 4th day group, while the control groups (intact group and PBS group)showed negative or weakly positive immunohistochemical staining 2) The OPTDM was significantly increased in the discs injected with Ad/CMV-hTGF ?1 compared to the contact discs or the discs injected with only PBS (P<0.05). 3) The nucleus pulposus tissues of the experimental discs exhibited a significant increase in the proteoglycan quantity in contrast with the contact discs or the discs injected with the PBS.Conclusions: 1) The nucleus pulposus tissues of the rabbit discs can be transferred by the Adenovirus-mediated vector carrying the human transforming growth factor 3 1 enconding gene, and can effectively express the hTGF- 1 protein. 2) The proteoglycan quantity in the nucleus pulposus injected with the Ad/CMV-hTGF- 1 of rabbit disc can be increased significantly. 3) The result of this study suggest that the intervertebral disc is an appropriate site for adenovirus-mediated transfer of exogenous genes. Gene therapy therefor may have useful application for reversing the degeneration of intervertebral discs in the science study and clinical management.