The role of subchondral bone resorption pits in osteoarthritis: MMP production by cells derived from bone marrow.

Abstract

OBJECTIVE:

The vascular invasion of bone marrow tissue into the subchondral plate is often observed in articular cartilage and we named it the subchondral bone absorption pit; however, its implication in the pathogenesis of osteoarthritis (OA) has been poorly understood. The purpose of this study was to evaluate its characteristics and roles in osteoarthritic conditions.

METHODS:

Articular cartilage specimens from 11 patients with medial type knee OA and 7 non-arthritic cadavers were analyzed with HE staining. OA sections were stained with safranin-O, TRAP (tartrate resistant acid phosphatase) and immunostained with anti-MMP-1, MMP-3, MMP-13, vitronectin receptor (VNR)-alpha chain, vimentin and bone morphogenic protein (BMP) 2/4 antibodies.

RESULTS:

Subchondral bone resorption pits were classified according to the extent of invasion: pits with bone marrow tissue were located within uncalcified cartilage below the tidemark in grade I and invaded beyond the tidemark in grade II, while no invasion was seen in grade 0. Grade II pits were dominant in OA compared to non-arthritic joints, especially medial condyles. Proteoglycan detected with safranin-O staining was lost around the tip of grade II pits and the density of pits was related to the modified Mankin Score. Cells in pits expressed vimentin, MMP-1, MMP-3 and MMP-13. Some polynuclear cells co-expressed VNR-alpha chain and MMP-13, whereas pits showed reparative features expressing BMP.

CONCLUSION:

These results suggest that subchondral bone resorption pits contribute to cartilage degradation by expressing matrix metalloproteinases in OA.

• Authors: A Shibakawa, K Yudoh, K Masuko-Hongo, T Kato, K Nishioka, H Nakamura
• Journal: Osteoarthritis and cartilage (Osteoarthritis Cartilage) Vol. 13 Issue 8 Pg. 679-87 (Aug 2005) ISSN: 1063-4584 [Print] England
• PMID: 15961327 (Publication Type: Journal Article)

Chemical References

• Bone Morphogenetic Proteins
• Proteoglycans
• Vimentin
• Vitronectin
• Collagenases
• MMP13 protein, human
• Matrix Metalloproteinase 13
• Matrix Metalloproteinases
• Matrix Metalloproteinase 3
• Matrix Metalloproteinase 1

Topics

• Aged
• Bone Marrow Cells (enzymology)
• Bone Morphogenetic Proteins (analysis)
• Bone Remodeling (physiology)
• Bone Resorption (metabolism, physiopathology)
• Cadaver
• Cartilage, Articular (blood supply, metabolism, physiopathology)
• Collagenases (analysis)
• Humans
• Immunohistochemistry (methods)
• Matrix Metalloproteinase 1 (analysis)
• Matrix Metalloproteinase 13
• Matrix Metalloproteinase 3 (analysis)
• Matrix Metalloproteinases (analysis)
• Neovascularization, Pathologic (physiopathology)
• Osteoarthritis, Knee (metabolism, physiopathology)
• Proteoglycans (metabolism)
• Vimentin (analysis)
• Vitronectin (analysis)