Gene transfer of the catabolic inhibitor TIMP-1 increases measured proteoglycans in cells from degenerated human intervertebral discs.
METHODS
Cells from degenerated intervertebral discs were transduced with an adenoviral vector delivering cDNA of the catabolic inhibitor, TIMP-1, and alterations in the measured proteoglycan were assessed.


OBJECTIVE
To assess the potential of TIMP-1 to favorably modify the proteoglycan content of degenerated intervertebral disc cells.


BACKGROUND
Gene therapy with anabolic factors has resulted in increased proteoglycan synthesis in intervertebral disc cells. Biochemical analysis of degenerated discs has revealed elevated levels of the catabolic enzymes, matrix metalloproteinase, suggesting an intimate role of these factors in the degenerative process. The use of TIMP-1, an endogenous inhibitor of matrix metalloproteinase, via gene therapy may provide an additional method to alter the degenerative processes occurring in the intervertebral disc.


METHODS
Degenerated intervertebral disc were isolated from eight patients undergoing elective surgical procedures. Cells were cultured in monolayer and transduced with different concentrations of either an adenoviral-tissue inhibitor of metalloproteinase-1 (Ad-TIMP-1) or adenoviral-bone morphogenic protein-2 (Ad-BMP-2) construct. Cells were cultured in a three-dimensional pellet and proteoglycan synthesis was assessed via 35S-sulfur incorporation.


RESULTS
Gene delivery of TIMP-1 and BMP-2 increased measured proteoglycan synthesis at each concentration assessed. IVD cells treated with Ad-TIMP-1 demonstrated an optimal response at a multiplicity of infection (MOI) of 100. Cells treated with Ad-BMP-2 demonstrated a progressive increase in proteoglycan synthesis with increasing viral concentrations.


CONCLUSIONS
Successful delivery of the anticatabolic gene, TIMP-1, results in increased measured proteoglycan in cultured degenerated disc cells. This finding supports catabolic inhibition as a promising avenue of research for the treatment of degenerative disc disease via gene therapy.
Wallach
Corey J
CJ
Ferguson Laboratory for Orthopaedic Research, Department of Orthopaedic Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA.
Sobajima
Satoshi
S
Watanabe
Yasuhiko
Y
Kim
Joseph S
JS
Georgescu
Helga I
HI
Robbins
Paul
P
Gilbertson
Lars G
LG
Kang
James D
JD
D000256:Adenoviridae / Q000235:genetics; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D002574:Cervical Vertebrae / Q000378:metabolism / Q000473:pathology; D015316:Genetic Therapy / Q000379:methods; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D007403:Intervertebral Disc / Q000378:metabolism* / Q000473:pathology; D007405:Intervertebral Disc Displacement / Q000378:metabolism / Q000473:pathology / Q000628:therapy; D008159:Lumbar Vertebrae / Q000378:metabolism / Q000473:pathology; D011509:Proteoglycans / Q000378:metabolism*; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism
C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D011509:Proteoglycans; D019715:Tissue Inhibitor of Metalloproteinase-1; D016212:Transforming Growth Factor beta