title: Age-related changes in gene expression patterns of matrix metalloproteinases and their collagenous substrates in mandibular condylar cartilage in rats.
abstract: Matrix metalloproteinases (MMPs) have been implicated in physiological cartilage matrix remodelling as well as in pathological and invasive extracellular matrix remodelling of tissue. Age-related changes in the gene expression patterns of MMPs in mandibular condylar cartilages (MCCs) were analysed. We examined the gene expression patterns of Mmp-8 and -13 and their substrates, Col1a1, Col2a1 and Col10a1, in MCC of growing and ageing rats. Temporomandibular joints of male Wistar rats aged 4, 8, 16 and 32 weeks were subjected to in situ hybridization analysis. Histologically, MMCs showed characteristics of growth plate cartilage at ages 4 and 8 weeks, and more closely resembled articular cartilage thereafter. Mmp-8 was expressed in the cells in all cartilaginous cell layers at ages 4 and 8 weeks, and then was localized only in the mature cells at ages 16 and 32 weeks. Whereas Mmp-13 expression was limited to the lowermost hypertrophic chondrocytes in the growth stage, mature chondrocytes instead of hypertrophic chondrocytes expressed Mmp-13 in adult non-hypertrophic MCC. Because Mmp-8 and -13 expression overlapped with Col2a1 and Col10a1, chondrocytes could play a pivotal role in degradation as well as production of the cartilaginous matrix in MCC.
authors.affiliation: Division of Orthodontics and Dentofacial Orthopedics, Tohoku University Graduate School of Dentistry, 4-1, Seiryo-machi, Aoba-ku, Sendai, Japan, 980-8575.
authors.forename: Jin-Wan
authors.initials: JW
authors.lastname: Bae
authors.forename: Ichiro
authors.initials: I
authors.lastname: Takahashi
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Sasano
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Onodera
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Mitani
authors.forename: Manabu
authors.initials: M
authors.lastname: Kagayama
authors.forename: Hideo
authors.initials: H
authors.lastname: Mitani
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D002358:Cartilage, Articular / Q000033:anatomy & histology / Q000201:enzymology* / Q000254:growth & development; D024042:Collagen Type I / Q000235:genetics; D024043:Collagen Type II / Q000235:genetics; D024121:Collagen Type X / Q000235:genetics; D017364:Collagenases / Q000032:analysis / Q000235:genetics; D015870:Gene Expression; D006132:Growth Plate / Q000201:enzymology*; D017403:In Situ Hybridization; D008297:Male; D008335:Mandibular Condyle / Q000033:anatomy & histology / Q000254:growth & development*; D053509:Matrix Metalloproteinase 13; D020784:Matrix Metalloproteinase 8 / Q000235:genetics; D020782:Matrix Metalloproteinases / Q000235:genetics*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D024042:Collagen Type I; D024043:Collagen Type II; D024121:Collagen Type X; D017364:Collagenases; D053509:Matrix Metalloproteinase 13; D020782:Matrix Metalloproteinases; C507083:Mmp13 protein, rat; D020784:Matrix Metalloproteinase 8