Selective assembly and remodelling of collagens II and IX associated with expression of the chondrocyte hypertrophic phenotype (original) (raw)
Related papers
The EMBO journal, 1984
The low mol. wt. collagen (64 K) synthesized by chick embryo chondrocytes in culture is deposited in the extracellular matrix; its deposition is strictly dependent upon a correct hydroxylation. In vivo the 64 K collagen has been isolated from the cartilage of tibiae obtained from 17-day-old chick embryos. The turnover of this collagen in the extracellular matrix is very rapid: within a few hours it is matured into a 30-K fragment released in the medium. Also this maturation is dependent upon a correct hydroxylation of the molecule. The underhydroxylated form, synthesized in the absence of ascorbic acid or in the presence of alpha-alpha' dipyridyl, is not deposited in the extracellular matrix and is directly secreted as 64 K collagen in the culture medium.
Transitions in collagen types during matrix-induced cartilage, bone, and bone marrow formation
Proceedings of the National Academy of Sciences, 1977
The localization of types I, II, and III collagens during bone matrix-induced sequential differentiation of cartilage, bone, and bone marrow was studied by specific immunofluorescence. Subcutaneous transplantation of coarse powders of demineralized rat bone matrix into allogeneic recipients resulted in new bone formation. After a transient appearance of polymorphonuclear leukocytes in the implant, fibroblasts appeared in close continguity to the matrix on day 3. Type III collagen was then localized as a fine network around the invading fibroblasts. On days 4--6 smaller amounts of type I were also detected around these proliferating cells. With the onset of chondrogenesis, type II collagen was detected in the cartilage matrix on day 6 and persisted until the early stages of bone formation. Vascular invasion of the implant was accompanied by osteogenesis on day 10. Type I collagen was demonstrated in the newly deposited bone matrix coating the surfaces of cartilage spicules and partic...
Characterization of collagenous matrix assembly in a chondrocyte model system
Journal of Biomedical Materials Research Part A - J BIOMED MATER RES PART A, 2009
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 ~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.
FEBS Letters, 1989
Cell cultures were nuttated from eptphyseal cartrlages, dtaphyseal penosteum, and muscle of 16-week human fetuses Total RNAs tsolated from these cultures were analyzed for the levels of mRNAs for major fibnllar collagens, two proteoglycan core protems and osteonectm In standard monolayer cultures the dtfferenttated chondrocyte phenotype was replaced by a dedtfferenttated one the mRNA levels of carttlage-specrfic type II collagen decreased upon subculturmg, whtle those of types I and III collagen, and the core proteins Increased When the cells were transferred to grow m agarose, redtfferenttatton (reappearance of type II collagen mRNA) occurred Ftbroblasts grown from penosteum and muscle were found to contam mRNAs for types I and III collagen and proteoglycan cores When these cells were transferred to agarose they acquired a shape mdtstmgutshable from chondrocytes, but no type II collagen mRNA was observed Cartrlage, Chondrocyte, Collagen, Proteoglycan
Biomaterials, 2002
The limited intrinsic repair capacity of articular cartilage has stimulated continuing efforts to develop tissue engineered analogues. Matrices composed of type II collagen and chondroitin sulfate (CS), the major constituents of hyaline cartilage, may create an appropriate environment for the generation of cartilage-like tissue. In this study, we prepared, characterized, and evaluated type II collagen matrices with and without CS. Type II collagen matrices were prepared using purified, pepsin-treated, type II collagen. Techniques applied to prepare type I collagen matrices were found unsuitable for type II collagen. Crosslinking of collagen and covalent attachment of CS was performed using 1-ethyl-3-(3-dimethyl aminopropyl)carbodiimide. Porous matrices were prepared by freezing and lyophilization, and their physico-chemical characteristics (degree of crosslinking, denaturing temperature, collagenase-resistance, amount of CS incorporated) established. Matrices were evaluated for their capacity to sustain chondrocyte proliferation and differentiation in vitro. After 7 d of culture, chondrocytes were mainly located at the periphery of the matrices. In contrast to type I collagen, type II collagen supported the distribution of cells throughout the matrix. After 14 d of culture, matrices were surfaced with a cartilagenous-like layer, and occasionally clusters of chondrocytes were present inside the matrix. Chondrocytes proliferated and differentiated as indicated by biochemical analyses, ultrastructural observations, and reverse transcriptase PCR for collagen types I, II and X. No major differences were observed with respect to the presence or absence of CS in the matrices. r
Journal of Orthopaedic Research, 1994
The cells responsible for skeletal growth are the chondrocytes of the cartilaginous growth plate. These cells differentiate through a series of maturational stages, establishing different zones in the growth plate. Among the major functions of these cells is the production of appropriate extracellular matrix, primarily composed of collagens and proteoglycans. To determine whether matrix synthesis varies with respect t o maturational stage and in which cell populations different collagens are expressed, bovine growth plates were analyzed by in situ hybridization t o mRNA and by Northern blot hybridization. The most abundant collagen mRNA in the growth plate was type-I1 collagen. This mRNA was present at relatively low levels in the most immature cells of the growth plate but increased several-fold as cells entered the proliferative stage and remained high through subsequent phases of maturation. Type-XI collagen mRNA and mRNA for the cartilage-characteristic proteoglycan, aggrecan. were codistributed with the type-I1 collagen mRNA; however, both were present in much smaller quantities. Type-X procollagen mRNA was localized to chondrocytes late in their maturation and was expressed at levels similar to the expression of type-I1 collagen. In situ hybridization of serial sections revealed that growth plate chondrocytes in their more mature stages contain both type-I1 and type-X collagen mRNA. Type-I collagen mRNA was not observed in growth plate chondrocytes at any maturational stage; rather, it was localized t o a morphologically distinct population of cells attached to calcifying cartilage septa in the region of vascular invasion. These data indicate that the genes for major matrix constituents synthesized by the growth plate in some cases are expressed differentially at different stages of cellular maturation and in other cases are expressed coordinately. The pattern of mRNA expression suggests possible mechanisms of gene regulation.
Collagens as organizers of extracellular matrix during morphogenesis
Seminars in Cell & Developmental Biology, 1996
The composition of the extracellular matrix (ECM) varies depending on tissue location and developmental stage. Collagens as the main constituents determine its structure and play a major role in determining its function. Polymers of fibrillar collagens (I,II) form the backbone of many ECMs, whereas many minor collagens regulate or stabilize their structural properties. Changes in the minor collagens introduce subtle modifications in intermolecular interactions, which can modulate the morphology of the ECM and responses of the underlying or embedded cells. The functions of these modulating collagens is now being investigated by a number of biochemical, genetic and molecular approaches.