The main hypothesis of the proposal is that after insult by an exogenous protease, such as chymopapain or alternate enzymes such as protease K or pronase, the nucleus pulposus has the ability to regenerate. This hypothesis will be tested by examining biochemical and histologic evidence or recovery using as a model system, dog intervertebral disc injected with protease (0.2 to 1 mg/level) and followed from 2 weeks to 1 year to determine the ability of the nucleus and annulus to recover. Proteoglycan synthesis will be used as a measure of matrix formation and studied using 35S-sulfate with in vitro labeling and the biochemical characterization including the chondrointin sulfate chain lengths, % chondrointin and keratan sulfate. This will be done using enzymes and analysis of the glucosamine/galactosamine ratio by high pressure liquid chromatography. Histologically, the samples will be followed at the light level after Safranin-O fast green staining and by immunofluorescent techniques with antibodies to matrix molecules such as fibronectin: The samples will be analyzed for changes in structure by morphometric analysis. The changes in the adjacent facet joints will also be followed for possible degenerative changes. This will be done with a biochemical analysis of the cartilage for water changes and changes in 35S-sulfate uptake and matrix protein alterations. The histology of the cartilage and bone will be followed by prelabeling in the animals with tetracycline analogs and using both light & fluorescent microscopy. In addition to remodeling after chymopapain injection, the proteases elaborated by the nucleus during early remodeling will be followed using specific substrates and inhibibors.

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Type
Research Project (R01)
Project #
2R01AR032145-04
Application #
3156191
Study Section
Orthopedics and Musculoskeletal Study Section (ORTH)
Project Start
1983-04-01
Project End
1990-03-31
Budget Start
1986-04-01
Budget End
1987-03-31
Support Year
4
Fiscal Year
1986
Total Cost
Indirect Cost
Name
University of Minnesota Twin Cities
Department
Type
Schools of Medicine
DUNS #
168559177
City
Minneapolis
State
MN
Country
United States
Zip Code
55455
Oegema Jr, T R; Johnson, S L; Aguiar, D J et al. (2000) Fibronectin and its fragments increase with degeneration in the human intervertebral disc. Spine (Phila Pa 1976) 25:2742-7
Aguiar, D J; Johnson, S L; Oegema, T R (1999) Notochordal cells interact with nucleus pulposus cells: regulation of proteoglycan synthesis. Exp Cell Res 246:129-37
Chelberg, M K; Banks, G M; Geiger, D F et al. (1995) Identification of heterogeneous cell populations in normal human intervertebral disc. J Anat 186 ( Pt 1):43-53
Oegema Jr, T R (1993) Biochemistry of the intervertebral disc. Clin Sports Med 12:419-39
Oegema Jr, T R; Swedenberg, S; Johnson, S L et al. (1992) Residual chymopapain activity after chemonucleolysis in normal intervertebral discs in dogs. J Bone Joint Surg Am 74:831-8
Maldonado, B A; Oegema Jr, T R (1992) Initial characterization of the metabolism of intervertebral disc cells encapsulated in microspheres. J Orthop Res 10:677-90
Thompson, J P; Oegema Jr, T R; Bradford, D S (1991) Stimulation of mature canine intervertebral disc by growth factors. Spine (Phila Pa 1976) 16:253-60
Oegema Jr, T R; Bradford, D S (1991) The inter-relationship of facet joint osteoarthritis and degenerative disc disease. Br J Rheumatol 30 Suppl 1:16-20
Oegema Jr, T R; Swedenburg, S M; Bradford, D S et al. (1988) Levels of keratan sulfate-bearing fragments rise predictably following chemonucleolysis of dog intervertebral discs with chymopapain. Spine (Phila Pa 1976) 13:707-11