title: Characterization of collagenous matrix assembly in a chondrocyte model system.
abstract: Collagen is a major component of the newly synthesized pericellular microenvironment of chondrocytes. Collagen types II, IX, and XI are synthesized and assembled into higher ordered complexes by a mechanism in which type XI collagen plays a role in nucleation of new fibrils, and in limiting fibril diameter. This study utilizes a cell line derived from the Swarm rat chondrosarcoma that allows the accumulation and assembly of pericellular matrix. Immunofluorescence and atomic force microscopy were used to assess early intermediates of fibril formation. Results indicate that this cell line synthesizes and secretes chondrocyte-specific pericellular matrix molecules including types II, IX, and XI collagen and is suitable for the study of newly synthesized collagen matrix under the experimental conditions used. AFM data indicate that small fibrils or assemblies of microfibrils are detectable and may represent precursors of the approximately 20 nm thin fibrils reported in cartilage. Treatment with hyaluronidase indicates that the dimensions of the small fibrils may be dependent upon the presence of hyaluronan within the matrix. This study provides information on the composition and organization of the newly synthesized extracellular matrix that plays a role in establishing the material properties and performance of biological materials such as cartilage.
authors.affiliation: Biomolecular Research Center, Boise State University, Boise, ID 83725, USA.
authors.forename: Sorcha
authors.initials: S
authors.lastname: Yingst
authors.forename: Kaci
authors.initials: K
authors.lastname: Bloxham
authors.forename: Lisa R
authors.initials: LR
authors.lastname: Warner
authors.forename: Raquel J
authors.initials: RJ
authors.lastname: Brown
authors.forename: Jennifer
authors.initials: J
authors.lastname: Cole
authors.forename: Linda
authors.initials: L
authors.lastname: Kenoyer
authors.forename: William B
authors.initials: WB
authors.lastname: Knowlton
authors.forename: Julia Thom
authors.initials: JT
authors.lastname: Oxford
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D019902:Chondrocytes / Q000166:cytology / Q000378:metabolism*; D024043:Collagen Type II / Q000378:metabolism* / Q000648:ultrastructure; D024081:Collagen Type IX / Q000378:metabolism* / Q000648:ultrastructure; D024161:Collagen Type XI / Q000378:metabolism* / Q000648:ultrastructure; D005109:Extracellular Matrix / Q000737:chemistry / Q000378:metabolism*; D006821:Hyaluronoglucosaminidase / Q000378:metabolism; D020894:Microfibrils / Q000378:metabolism / Q000648:ultrastructure; D018625:Microscopy, Atomic Force; D010641:Phenotype; D051381:Rats
chemical_list: D024043:Collagen Type II; D024081:Collagen Type IX; D024161:Collagen Type XI; D006821:Hyaluronoglucosaminidase