Biosynthesis of a disulphide-bonded short-chain collagen by calf growth-plate cartilage

Collagen biosynthesis by organ cultures of the hypertrophic zone of calf growth-plate cartilage was studied. It was found that this tissue devotes a large portion of its biosynthetic commitment towards production of a collagen molecule comprising short collagen chains. This collagen is similar to short-chain collagens synthesized by chick-embryo tibiotarsus, rabbit growth-plate cartilage and chick chondrocytes grown in three-dimensional gels. However, in contrast with the collagen synthesized in these three systems, the short-chain collagen synthesized by calf growth-plate hypertrophic cartilage is stabilized by disulphide bonds localized within the pepsin-resistant triple-helical collagenous domains of these molecules.

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A disulfide-bonded short chain collagen synthesized by degenerative and calcifying zones of bovine growth plate cartilage.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(19)83694-3 ◽

1985 ◽

Vol 260 (6) ◽

pp. 3798-3803 ◽

Cited By ~ 2

Author(s):

W T Grant ◽

M D Sussman ◽

G Balian

Keyword(s):

Growth Plate ◽

Short Chain ◽

Growth Plate Cartilage

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The synthesis of type X collagen by bovine and human growth-plate chondrocytes

Journal of Cell Science ◽

10.1242/jcs.99.3.641 ◽

1991 ◽

Vol 99 (3) ◽

pp. 641-649 ◽

Cited By ~ 3

Author(s):

A. Marriott ◽

S. Ayad ◽

M.E. Grant

Keyword(s):

Growth Plate ◽

Type I Collagen ◽

Polyacrylamide Gel Electrophoresis ◽

Human Growth ◽

Type I ◽

Collagen Gels ◽

Type X Collagen ◽

Growth Plate Chondrocytes ◽

Growth Plate Cartilage ◽

Disulphide Bonds

Chondrocytes were isolated from bovine growth-plate cartilage and cultured within type I collagen gels. A major collagen with chains of Mr 59,000, decreasing to 47,000 on pepsinization, was synthesized and identified as type X collagen. This collagen was cleaved at two sites by mammalian collagenase, resulting in a major triple-helical fragment with chains of Mr 32,000. The species of Mr 59,000, 47,000 and 32,000 were not detected by SDS-polyacrylamide gel electrophoresis before reduction, indicating the presence of disulphide bonds within the triple helix. In contrast, similar biosynthetic studies with human growth-plate cartilage in organ culture, indicated that human type X collagen does not contain disulphide bonds. A polyclonal antiserum was raised to bovine type X collagen and used in immunolocalization studies to provide direct evidence for the association of type X collagen with the hypertrophic chondrocytes in both bovine and human growth plates during development.

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Quantitative analysis of type X-collagen biosynthesis by embryonic-chick sternal cartilage

Biochemical Journal ◽

10.1042/bj2330357 ◽

1986 ◽

Vol 233 (2) ◽

pp. 357-367 ◽

Cited By ~ 24

Author(s):

S A Jimenez ◽

R Yankowski ◽

A M Reginato

Keyword(s):

Quantitative Analysis ◽

Hyaline Cartilage ◽

Type Ii Collagen ◽

Type Ii ◽

Embryonic Chick ◽

Collagen Biosynthesis ◽

Molecular Aggregate ◽

Type X Collagen ◽

Organ Cultures ◽

Disulphide Bonds

We have performed a quantitative analysis of the various collagens biosynthesized by organ cultures of whole embryonic-chick sternum and its separate anatomical regions corresponding to the zones of permanent hyaline and presumptive-calcification cartilages. Our studies demonstrated that embryonic-chick sternum devotes a large portion of its biosynthetic commitment towards production of Type X collagen, which represented approx. 18% of the total newly synthesized collagen. Comparison of the collagens biosynthesized by the permanent hyaline cartilage and by the cartilage from the presumptive-calcification zone demonstrated that Type X-collagen production was strictly confined to the presumptive-calcification region. Sequential extraction of the newly synthesized Type X collagen demonstrated the existence of two separate populations. One population (approx. 20%) was composed of easily extractable molecules that were solubilized with 1.0 m-NaCl/50 mM-Tris/HCI buffer, pH 7.4. The second population was composed of molecules that were not extractable even after repeated pepsin digestion, but became completely solubilized after treatment with 20 mM-dithiothreitol/0.15 M-NaCl buffer at neutral pH. These results suggest that most of the Type X collagen normally exists in the tissue as part of a pepsin-resistant molecular aggregate that may be stabilized by disulphide bonds. Quantitative analysis of the proportion of Type X collagen relative to the other collagens synthesized in the cultures indicated that this collagen was a major biosynthetic product of the presumptive-calcification cartilage, since it represented about 35% of the total collagen synthesized by this tissue. In contrast, the permanent hyaline cartilage did not display any detectable synthesis of Type X collagen. When compared on a per-cell basis, the chondrocytes from the presumptive-calcification zone synthesized approx. 33% more Type X collagen than the amount of Type II collagen synthesized by the chondrocytes from the permanent-hyaline-cartilage zone. Subsequently, it was demonstrated that Type X collagen is a structural component of chick sternum matrix, since quantitative amounts could be extracted from the region of presumptive calcification of 17-day-old chick-embryo sterna and from the calcified portion of adult-chick sterna. The strict topographic distribution in the expression of Type X collagen biosynthesis to the zone of presumptive calcification suggests that this collagen may play an important role in initiation or progression of tissue calcification.

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Expression of a Truncated, Kinase-Defective TGF-β Type II Receptor in Mouse Skeletal Tissue Promotes Terminal Chondrocyte Differentiation and Osteoarthritis

The Journal of Cell Biology ◽

10.1083/jcb.139.2.541 ◽

1997 ◽

Vol 139 (2) ◽

pp. 541-552 ◽

Cited By ~ 355

Author(s):

Rosa Serra ◽

Mahlon Johnson ◽

Ellen H. Filvaroff ◽

James LaBorde ◽

Daniel M. Sheehan ◽

...

Keyword(s):

Articular Cartilage ◽

Transgenic Mice ◽

Growth Plate ◽

Dominant Negative Mutant ◽

Type I ◽

Type Ii ◽

Type X Collagen ◽

Skeletal Tissue ◽

Hypertrophic Cartilage ◽

Growth Plate Cartilage

Members of the TGF-β superfamily are important regulators of skeletal development. TGF-βs signal through heteromeric type I and type II receptor serine/threonine kinases. When over-expressed, a cytoplasmically truncated type II receptor can compete with the endogenous receptors for complex formation, thereby acting as a dominant-negative mutant (DNIIR). To determine the role of TGF-βs in the development and maintenance of the skeleton, we have generated transgenic mice (MT-DNIIR-4 and -27) that express the DNIIR in skeletal tissue. DNIIR mRNA expression was localized to the periosteum/perichondrium, syno-vium, and articular cartilage. Lower levels of DNIIR mRNA were detected in growth plate cartilage. Transgenic mice frequently showed bifurcation of the xiphoid process and sternum. They also developed progressive skeletal degeneration, resulting by 4 to 8 mo of age in kyphoscoliosis and stiff and torqued joints. The histology of affected joints strongly resembled human osteo-arthritis. The articular surface was replaced by bone or hypertrophic cartilage as judged by the expression of type X collagen, a marker of hypertrophic cartilage normally absent from articular cartilage. The synovium was hyperplastic, and cartilaginous metaplasia was observed in the joint space. We then tested the hypothesis that TGF-β is required for normal differentiation of cartilage in vivo. By 4 and 8 wk of age, the level of type X collagen was increased in growth plate cartilage of transgenic mice relative to wild-type controls. Less proteoglycan staining was detected in the growth plate and articular cartilage matrix of transgenic mice. Mice that express DNIIR in skeletal tissue also demonstrated increased Indian hedgehog (IHH) expression. IHH is a secreted protein that is expressed in chondrocytes that are committed to becoming hypertrophic. It is thought to be involved in a feedback loop that signals through the periosteum/ perichondrium to inhibit cartilage differentiation. The data suggest that TGF-β may be critical for multifaceted maintenance of synovial joints. Loss of responsiveness to TGF-β promotes chondrocyte terminal differentiation and results in development of degenerative joint disease resembling osteoarthritis in humans.

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Matrix Metalloproteinases Are Not Essential for Aggrecan Turnover during Normal Skeletal Growth and Development

Molecular and Cellular Biology ◽

10.1128/mcb.25.8.3388-3399.2005 ◽

2005 ◽

Vol 25 (8) ◽

pp. 3388-3399 ◽

Cited By ~ 32

Author(s):

Christopher B. Little ◽

Clare T. Meeker ◽

Rosalind M. Hembry ◽

Natalie A. Sims ◽

Kate E. Lawlor ◽

...

Keyword(s):

Matrix Metalloproteinases ◽

Growth Plate ◽

Growth And Development ◽

Type Ii Collagen ◽

Skeletal Growth ◽

Long Bone ◽

Transitional Region ◽

Type Ii ◽

Hypertrophic Cartilage ◽

Growth Plate Cartilage

ABSTRACT The growth plate is a transitional region of cartilage and highly diversified chondrocytes that controls long bone formation. The composition of growth plate cartilage changes markedly from the epiphysis to the metaphysis, notably with the loss of type II collagen, concomitant with an increase in MMP-13; type X collagen; and the C-propeptide of type II collagen. In contrast, the fate of aggrecan in the growth plate is not clear: there is biosynthesis and loss of aggrecan from hypertrophic cartilage, but the mechanism of loss is unknown. All matrix metalloproteinases (MMPs) cleave aggrecan between amino acids N341 and F342 in the proteinase-sensitive interglobular domain (IGD), and MMPs in the growth plate are thought to have a role in aggrecanolysis. We have generated mice with aggrecan resistant to proteolysis by MMPs in the IGD and found that the mice develop normally with no skeletal deformities. The mutant mice do not accumulate aggrecan, and there is no significant compensatory proteolysis occurring at alternate sites in the IGD. Our studies reveal that MMP cleavage in this key region is not a predominant mechanism for removing aggrecan from growth plate cartilage.

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