Proteoglycans are produced by most eukaryotic cells and versatile components of pericellular extracellular matrices. They belong to many different protein families. Their functions vary from the physical effects proteoglycan aggrecan, which binds with link hyaluronan form multi-molecular aggregates in cartilage; intercalated membrane CD44 that has a is receptor cell-binding site for hyaluronan; heparan sulfate proteoglycans syndecan other families provide matrix binding sites cell-surface...

Abstract Objective To investigate the role of matrix metalloproteinase 13 (MMP‐13; collagenase 3) in osteoarthritis (OA). Methods OA was surgically induced knees MMP‐13–knockout mice and wild‐type mice, were compared. Histologic scoring femoral tibial cartilage aggrecan loss (0–3 scale), erosion (0–7 chondrocyte hypertrophy (0–1 as well osteophyte size scale) maturity performed. Serial sections stained for type X collagen MMP‐generated neoepitope DIPEN. Results Following surgery, more severe...

The assembly and degradation of extracellular matrix (ECM) molecules are crucial processes during bone development. In this study, we show that ECM remodeling is a critical rate-limiting step in endochondral formation. Matrix metalloproteinase (MMP) 13 (collagenase 3) poised to play role formation because its expression both terminal hypertrophic chondrocytes the growth plate osteoblasts. Moreover, mutation human MMP13 gene causes Missouri variant spondyloepimetaphyseal dysplasia....

Degradation of the large cartilage proteoglycan aggrecan in arthritis involves an unidentified enzyme aggrecanase, and at least one matrix metalloproteinases. Proteinase-sensitive cleavage sites interglobular domain (IGD) have been identified for many humman MMPs, as well aggrecanase other proteinases. The major MMP expressed by chondrocytes stimulated with retinoic acid to degrade their is collagenase-3 or MMP-13. Because its potential role degradation we examined specificity MMP-13...

The action of three matrix metalloproteinases (MMPs), 72- and 95-kDa gelatinases (MMP-2 MMP-9) PUMP (MMP-7), a cysteine proteinase, cathepsin B, were investigated on aggrecan the major proteoglycan cartilage. All enzymes cleaved although activity gelatinase was very low. Specific cleavage sites following incubation with purified G1-G2 domain fragment (150 kDa). Both produced 110-kDa G2 56-kDa G1 products by single at an Asn-Phe bond within interglobular close to domain. This similar...

Monoclonal antibodies have been prepared that react specifically with the neoepitopes present on proteoglycan degradation products generated from proteolytic cleavage of aggrecan in interglobular domain. Antibody BC-3 recognizes new N-terminus (ARGSV...) produced by action as yet uncharacterized activity, 'aggrecanase', and antibody BC-4 C-terminus (...DIPEN) matrix metalloproteinases. Specificity for these neoepitope sequences was determined competitive e.l.i.s.a. using synthetic peptide...

Proteolytic degradation of aggrecan is a hallmark the pathology arthritis, yet identity enzyme(s) in cartilage responsible for this unknown. Previous studies have suggested that matrix metalloproteinases (MMPs) may be involved but there has been no definitive evidence their direct action proteolysis human arthritis. We now show unequivocally fragments derived from specific MMPs can detected synovial fluids patients with both inflammatory and noninflammatory neoepitope monoclonal antibody...

Aggrecan loss from cartilage in arthritis is mediated by aggrecanases. Aggrecanases cleave aggrecan preferentially the chondroitin sulfate-2 (CS-2) domain and secondarily at E(373) downward arrow(374)A bond interglobular (IGD). However, IGD cleavage may be more deleterious for biomechanics because it releases entire CS-containing portion of aggrecan. Recent studies identifying aggrecanase-2 (ADAMTS-5) as predominant aggrecanase mouse have not distinguished aggrecanolysis CS-2 domain. We...

Abstract Introduction Physiological and pathophysiological cartilage turnover may coexist in articular cartilage. The distinct enzymatic processes leading to irreversible damage, compared with those needed for continuous self-repair regeneration, remain be identified. We investigated the capacity of repair chondrocytes by analyzing their ability initiate an anabolic response subsequent three different levels catabolic stimulation. Methods Cartilage degradation was induced oncostatin M tumour...

A workshop held last June by the National Institutes of Health (NIH) Director's Office, Nature Publishing Group, and Science focused on role that journals play in supporting scientific research is reproducible, robust, transparent. The "Principles Guidelines for Reporting Preclinical Research" (http://www.nih.gov/research-training/rigor-reproducibility/principles-guidelines-reporting-preclinical-research) emerged from have since been endorsed nearly 80 societies, journals, associations.

Pain is the predominant symptom of osteoarthritis, but connection between joint damage and genesis pain not well understood. Loss articular cartilage a hallmark it occurs through enzymatic degradation aggrecan by cleavage mediated disintegrin metalloproteinase with thrombospondin motif 4 (ADAMTS-4) or ADAMTS-5 in interglobular domain (E373–374A). Further MMPs (N341–342F) releases 32-amino-acid fragment (32-mer). We investigated role this 32-mer driving pain. found that excites dorsal root...

Normal and pathological turnover of proteoglycans in articular cartilage involves its cleavage close to the N-terminal G1 domain responsible for aggregation. A fragment containing G2 domains pig was therefore used as a substrate investigate degradation by metalloproteinase stromelysin related recombinant enzymes. The stromelysins produced an apparent single yielding 56 kDa 110 kDa. Rabbit bone much more active against G1-G2 proteoglycan aggregates than human stromelysin-1 stromelysin-2. All...

The actions of recombinant human fibroblast collagenase (MMP1), purified polymorphonuclear leucocyte (MMP8) and their N-terminal catalytic domain fragments against cartilage aggrecan an G1-G2 fragment have been investigated in vitro. After activation with stromelysin typsin, both collagenases were able to degrade porcine aggrecans a similar extent. An (150 kDa) was used identify specific cleavage sites occurring within the proteinase-sensitive interglobular between G1 G2. Two found; one at...

To determine whether an aggrecan 32-mer fragment derived from dual ADAMTS and matrix metalloproteinase (MMP) cleavage in the interglobular domain was bioactive and, if so, to elucidate its mechanism of action.Mouse primary chondrocytes, synovial fibroblasts, or peritoneal macrophages, human cells cell lines myeloid differentiation factor 88 (MyD88)-deficient Toll-like receptor 2 (TLR-2)-deficient mice were stimulated with synthetic mouse peptide, a scrambled native, glycosylated peptide....

Matrix metalloproteinase (MMP)‐19 and MMP‐20 (enamelysin) are two recently discovered members of the MMP family. These enzymes involved in degradation various components extracellular matrix (ECM) during development, haemostasis pathological conditions. Whereas MMP‐19 mRNA is found widely expressed body tissues, including synovium normal rheumatoid arthritic patients, expression restricted to enamel organ. In this study we investigated ability cleave macromolecules characterising cartilage...

A family of six insulin-like growth factor binding proteins (IGFBPs) bind IGF-I and modulate its biological activity. IGFBPs may to macromolecules on the cell surface or pericellular extracellular matrix, this interaction their effect IGF To date, little is known about specificity in regulation action brain. We therefore explored whether were associated with membrane matrix components rat sites characteristics an IGFBP found olfactory bulb mitral layer. This was identified as IGFBP-2 by...

Native and recombinant neutrophil collagenase (MMP-8) was shown to cleave at the E373-A374 'aggrecanase' site in interglobular domain of aggrecan. The time course digestion vitro showed that MMP-8 cleaved initially N341-F342, predominant metalloproteinase site, before cleaving site. A synthetic peptide, IPENFFG, inhibited cleavage but not N341-F342 vitro, indicating sequence a less preferred for than N341-F342. IPENFFG also release A374 RGSVI fragments from cartilage explant culture,...

Fragments of fibronectin occur naturally in vivo and are increased the synovial fluid arthritis patients. We have studied 45kDa fragment (Fn-f 45), representing N-terminal collagen-binding domain fibronectin, for its ability to modulate expression metalloproteinases by porcine articular chondrocytes vitro. report that stimulation cultured chondrocytes, or cartilage explants, with Fn-f 45 levels matrix metalloproteinase-13 (MMP-13; collagenase-3) released into conditioned medium a...