title: Distribution of pericellular matrix molecules in the temporomandibular joint and their chondroprotective effects against inflammation.
abstract: The objectives of this study were to (1) determine the distribution and synthesis of pericellular matrix (PCM) molecules (collagen VI, collagen IV and laminin) in rat temporomandibular joint (TMJ) and (2) investigate the effects of PCM molecules on chondrocytes against inflammation in osteoarthritis. Four zones (fibrous, proliferating, mature and hypertrophic) of condylar cartilage and three bands (anterior, intermediate and posterior) of disc were analysed by immunohistochemistry for the presence of PCM molecules in rat TMJs. Isolated chondrocytes were pre-treated with PCM molecules before being subjected to interleukin (IL)-1β treatment to stimulate inflammation. The responses of the chondrocytes were analysed using gene expression, nitric oxide release and matrix metalloproteinase (MMP)-13 production measures. Histomorphometric analyses revealed that the highest areal deposition of collagen VI (67.4%), collagen IV (45.7%) and laminin (52.4%) was in the proliferating zone of TMJ condylar cartilage. No significant difference in the distribution of PCM molecules was noted among the three bands of the TMJ disc. All three PCM molecules were expressed intracellularly by chondrocytes cultured in the monolayer. Among the PCM molecules, pre-treatment with collagen VI enhanced cellular proliferation, ameliorated IL-1β-induced MMP-3, MMP-9, MMP-13 and inducible nitric oxide synthase gene expression, and attenuated the downregulation of cartilage matrix genes, including collagen I, aggrecan and cartilage oligomeric matrix protein (COMP). Concurrently, collagen VI pretreatment inhibited nitric oxide and MMP-13 production. Our study demonstrates for the first time the distribution and role of PCM molecules, particularly collagen VI, in the protection of chondrocytes against inflammation.
authors.affiliation: Faculty of Dentistry, National University of Singapore, Singapore.
authors.forename: Wern Cui
authors.initials: WC
authors.lastname: Chu
authors.affiliation: Faculty of Dentistry, National University of Singapore, Singapore.
authors.forename: Shipin
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Faculty of Dentistry, National University of Singapore, Singapore.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Sng
authors.affiliation: Faculty of Dentistry, National University of Singapore, Singapore.
authors.forename: Yu Jie
authors.initials: YJ
authors.lastname: Ong
authors.affiliation: Faculty of Dentistry, National University of Singapore, Singapore.
authors.forename: Wen-Li
authors.initials: WL
authors.lastname: Tan
authors.affiliation: Faculty of Dentistry, National University of Singapore, Singapore.
authors.forename: Vivien Y
authors.initials: VY
authors.lastname: Ang
authors.affiliation: Orthopaedic Research Laboratory, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Casper B
authors.initials: CB
authors.lastname: Foldager
authors.affiliation: Faculty of Dentistry, National University of Singapore, Singapore.|Tissue Engineering Program, Life Sciences Institute, National University of Singapore, Singapore.
authors.forename: Wei Seong
authors.initials: WS
authors.lastname: Toh
mesh_terms: D000818:Animals; D019902:Chondrocytes / Q000166:cytology / Q000378:metabolism*; D003094:Collagen / Q000378:metabolism*; D005260:Female; D007150:Immunohistochemistry; D007249:Inflammation / Q000378:metabolism; D053583:Interleukin-1beta; D007797:Laminin / Q000378:metabolism*; D053509:Matrix Metalloproteinase 13 / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D010003:Osteoarthritis / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013704:Temporomandibular Joint / Q000166:cytology / Q000378:metabolism*
chemical_list: D053583:Interleukin-1beta; D007797:Laminin; D009569:Nitric Oxide; D003094:Collagen; D053509:Matrix Metalloproteinase 13; C507083:Mmp13 protein, rat