Gene deletion of either interleukin-1beta, interleukin-1beta-converting enzyme, inducible nitric oxide synthase, or stromelysin 1 accelerates the development of knee osteoarthritis in mice after surgical transection of the medial collateral ligament and partial medial meniscectomy.
OBJECTIVE
To investigate the development of osteoarthritis (OA) after transection of the medial collateral ligament and partial medial meniscectomy in mice in which genes encoding either interleukin-1beta (IL-1beta), IL-1beta-converting enzyme (ICE), stromelysin 1, or inducible nitric oxide synthase (iNOS) were deleted.


METHODS
Sectioning of the medial collateral ligament and partial medial meniscectomy were performed on right knee joints of wild-type and knockout mice. Left joints served as unoperated controls. Serial histologic sections were obtained from throughout the whole joint of both knees 4 days or 1, 2, 3, or 4 weeks after surgery. Sections were graded for OA lesions on a scale of 0-6 and were assessed for breakdown of tibial cartilage matrix proteoglycan (aggrecan) and type II collagen by matrix metalloproteinases (MMPs) and aggrecanases with immunohistochemistry studies using anti-VDIPEN, anti-NITEGE, and Col2-3/4C(short) neoepitope antibodies. Proteoglycan depletion was assessed by Alcian blue staining and chondrocyte cell death, with the TUNEL technique.


RESULTS
All knockout mice showed accelerated development of OA lesions in the medial tibial cartilage after surgery, compared with wild-type mice. ICE-, iNOS-, and particularly IL-1beta-knockout mice developed OA lesions in the lateral cartilage of unoperated limbs. Development of focal histopathologic lesions was accompanied by increased levels of MMP-, aggrecanase-, and collagenase-generated cleavage neoepitopes in areas around lesions, while nonlesional areas showed no change in immunostaining. Extensive cell death was also detected by TUNEL staining in focal areas around lesions.


CONCLUSIONS
We postulate that deletion of each of these genes, which encode molecules capable of producing degenerative changes in cartilage, leads to changes in the homeostatic controls regulating the balance between anabolism and catabolism, favoring accelerated cartilage degeneration. These observations suggest that these genes may play important regulatory roles in maintaining normal homeostasis in articular cartilage matrix turnover.
Clements
Kristen M
KM
Imperial College London, London, UK.
Price
Joanne S
JS
Chambers
Mark G
MG
Visco
Denise M
DM
Poole
A Robin
AR
Mason
Roger M
RM
D051722:ADAM Proteins; D000071121:ADAMTS4 Protein; D000071116:ADAMTS5 Protein; D053674:Aggrecans; D000423:Alcian Blue; D000818:Animals; D000906:Antibodies; D020170:Caspase 1 / Q000235:genetics*; D024043:Collagen Type II / Q000276:immunology / Q000378:metabolism; D004396:Coloring Agents; D053938:DNA Fragmentation; D016326:Extracellular Matrix Proteins; D017353:Gene Deletion; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D007375:Interleukin-1 / Q000235:genetics*; D037181:Lectins, C-Type; D008297:Male; D019278:Matrix Metalloproteinase 3 / Q000235:genetics*; D017888:Medial Collateral Ligament, Knee / Q000601:surgery; D008592:Menisci, Tibial / Q000601:surgery; D008666:Metalloendopeptidases / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D019001:Nitric Oxide Synthase / Q000235:genetics*; D052247:Nitric Oxide Synthase Type II; D009842:Oligopeptides; D020370:Osteoarthritis, Knee / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery*; D010446:Peptide Fragments; D011183:Postoperative Complications / Q000473:pathology; D011348:Procollagen N-Endopeptidase; D011509:Proteoglycans / Q000378:metabolism; D013194:Staining and Labeling
C508320:Acan protein, mouse; D053674:Aggrecans; D000906:Antibodies; D024043:Collagen Type II; D004396:Coloring Agents; D016326:Extracellular Matrix Proteins; D007375:Interleukin-1; D037181:Lectins, C-Type; D009842:Oligopeptides; D010446:Peptide Fragments; D011509:Proteoglycans; C093378:peptide VDIPEN; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; D020170:Caspase 1; D051722:ADAM Proteins; D000071116:ADAMTS5 Protein; C498489:Adamts5 protein, mouse; D008666:Metalloendopeptidases; D011348:Procollagen N-Endopeptidase; D019278:Matrix Metalloproteinase 3; D000071121:ADAMTS4 Protein; D000423:Alcian Blue