title: Interleukin-1 receptor antagonist delivered directly and by gene therapy inhibits matrix degradation in the intact degenerate human intervertebral disc: an in situ zymographic and gene therapy study.
abstract: Data implicate IL-1 in the altered matrix biology that characterizes human intervertebral disc (IVD) degeneration. In the current study we investigated the enzymic mechanism by which IL-1 induces matrix degradation in degeneration of the human IVD, and whether the IL-1 inhibitor IL-1 receptor antagonist (IL-1Ra) will inhibit degradation. A combination of in situ zymography (ISZ) and immunohistochemistry was used to examine the effects of IL-1 and IL-1Ra on matrix degradation and metal-dependent protease (MDP) expression in explants of non-degenerate and degenerate human IVDs. ISZ employed three substrates (gelatin, collagen, casein) and different challenges (IL-1beta, IL-1Ra and enzyme inhibitors). Immunohistochemistry was undertaken for MDPs. In addition, IL-1Ra was introduced into degenerate IVD explants using genetically engineered constructs. The novel findings from this study are: IL-1Ra delivered directly onto explants of degenerate IVDs eliminates matrix degradation as assessed by multi-substrate ISZ; there is a direct relationship between matrix degradation assessed by ISZ and MDP expression defined by immunohistochemistry; single injections of IVD cells engineered to over-express IL-1Ra significantly inhibit MDP expression for two weeks. Our findings show that IL-1 is a key cytokine driving matrix degradation in the degenerate IVD. Furthermore, IL-1Ra delivered directly or by gene therapy inhibits IVD matrix degradation. IL-1Ra could be used therapeutically to inhibit degeneration of the IVD.
authors.affiliation: Tissue Injury and Repair Group, Research School of Clinical and Laboratory Sciences, The School of Medicine, University of Manchester, Manchester M13 9PT, UK.
authors.forename: Christine L
authors.initials: CL
authors.lastname: Le Maitre
authors.forename: Judith A
authors.initials: JA
authors.lastname: Hoyland
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Freemont
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002470:Cell Survival / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005109:Extracellular Matrix / Q000235:genetics* / Q000378:metabolism; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D015316:Genetic Therapy / Q000379:methods*; D006801:Humans; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D053590:Interleukin 1 Receptor Antagonist Protein / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D007375:Interleukin-1 / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D007403:Intervertebral Disc / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D007405:Intervertebral Disc Displacement / Q000378:metabolism* / Q000473:pathology; D008297:Male; D061965:Matrix Metalloproteinase Inhibitors; D020782:Matrix Metalloproteinases / Q000378:metabolism; D008875:Middle Aged
chemical_list: D004791:Enzyme Inhibitors; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1; D061965:Matrix Metalloproteinase Inhibitors; D020782:Matrix Metalloproteinases