Biological effects of CTGF combined with TIMP1 mediated by adeno associated virus to degenerated lumbar intervertebral discs in rhesus monkey.

Objective To study the biological effect of connective tissue growth factor (CTGF) and tissue inhibitor of metalloproteinases 1 (TIMPI) mediated by adeno-associated virus 2 (AAV2) to rhesus monkey lumbar intervertebral discs in vivo. Methods To establish a novel model of lumbar disc degeneration in the rhesus monkey using percutaneous needle puncture guided by CT. The rAAV2-CTGF-IRES-T1MPI was injected percutaneously with minimal invasive technique. The mRNA expression of CTGF and TIMP1 was determined through RT-PCR. The biological effect of rAAV2-CTGF-IRES-TIMP1 was examined by RT-PCR, ~(35)S incorporation assay. Results At the 8th, 16th, 24th week after gene transfection, the expression of CTGF mRNA were 10.02, 2.39, 0.91 times respectively compared with the PBS control group; TIMP1 mRNA expression were 6.08, 3.81, 2.67 times respectively compared with the PBS control group; collagen type Ⅱ mRNA expression for the PBS control group were 145.51%, 174.72%, 113.73% respectively; proteoglycan mRNA expression were 461.19%, 191.46%, 301.39% respectively compared with the PBS contrel group; the efficiency of proteoglycan synthesis were 455.06%, 285.97%, 165.58% respectively compared with PBS control group. Conclusion The longer-term expression of CTGF and TIMP1 genes mediated by adeno-associated virus can achieve in vivo after transferring into the intervertebral disc, and also can increase the proteoglycan and collagen type Ⅱ synthesis, which delay disc degeneration. Key words: Adenoviruses, simian;  Matrix metalloproteinases 1;  Macaca mulatta;  Intervertebral disk