During endochondral bone formation, hypertrophic cartilage is replaced by bone or by a marrow cavity. The matrix of hypertrophic cartilage contains at least one tissue-specific component, type X collagen. Structurally type X collagen contains both a collagenous domain and a COOH-terminal non-collagenous one. However, the function(s) of this molecule have remained largely speculative. To examine the behavior and functions of type X collagen within hypertrophic cartilage, we (Chen, Q., E. Gibney, J. M. Fitch, C. Linsenmayer, T. M. Schmid, and T. F. Linsenmayer. 1990. Proc. Natl. Acad. Sci. USA. 87:8046-8050) recently devised an in vitro system in which exogenous type X collagen rapidly (15 min to several hours) moves into non-hypertrophic cartilage. There the molecule becomes associated with preexisting cartilage collagen fibrils. In the present investigation, we find that the isolated collagenous domain of type X collagen is sufficient for its association with fibrils. Furthermore, when non-hypertrophic cartilage is incubated for a longer time (overnight) with "intact" type X collagen, the molecule is found both in the matrix and inside of the chondrocytes. The properties of the matrix of such type X collagen-infiltrated cartilage become altered. Such changes include: (a) antigenic masking of type X collagen by proteoglycans; (b) loss of the permissiveness for further infiltration by type X collagen; and (c) enhanced accumulation of proteoglycans. Some of these changes are dependent on the presence of the COOH-terminal non-collagenous domain of the molecule. In fact, the isolated collagenous domain of type X collagen appears to exert an opposite effect on proteoglycan accumulation, producing a net decrease in their accumulation, particularly of the light form(s) of proteoglycans. Certain of these matrix alterations are similar to ones that have been observed to occur in vivo. This suggests that within hypertrophic cartilage type X collagen has regulatory as well as structural functions, and that these functions are achieved specifically by its two different domains.
Skip Nav Destination
Article navigation
1 May 1992
Article|
May 01 1992
Domains of type X collagen: alteration of cartilage matrix by fibril association and proteoglycan accumulation.
Q Chen,
Q Chen
Department of Anatomy and Cellular Biology, Tufts University Health Sciences Schools, Boston, Massachusetts 02111.
Search for other works by this author on:
C Linsenmayer,
C Linsenmayer
Department of Anatomy and Cellular Biology, Tufts University Health Sciences Schools, Boston, Massachusetts 02111.
Search for other works by this author on:
H Gu,
H Gu
Department of Anatomy and Cellular Biology, Tufts University Health Sciences Schools, Boston, Massachusetts 02111.
Search for other works by this author on:
T M Schmid,
T M Schmid
Department of Anatomy and Cellular Biology, Tufts University Health Sciences Schools, Boston, Massachusetts 02111.
Search for other works by this author on:
T F Linsenmayer
T F Linsenmayer
Department of Anatomy and Cellular Biology, Tufts University Health Sciences Schools, Boston, Massachusetts 02111.
Search for other works by this author on:
Q Chen
Department of Anatomy and Cellular Biology, Tufts University Health Sciences Schools, Boston, Massachusetts 02111.
C Linsenmayer
Department of Anatomy and Cellular Biology, Tufts University Health Sciences Schools, Boston, Massachusetts 02111.
H Gu
Department of Anatomy and Cellular Biology, Tufts University Health Sciences Schools, Boston, Massachusetts 02111.
T M Schmid
Department of Anatomy and Cellular Biology, Tufts University Health Sciences Schools, Boston, Massachusetts 02111.
T F Linsenmayer
Department of Anatomy and Cellular Biology, Tufts University Health Sciences Schools, Boston, Massachusetts 02111.
Online ISSN: 1540-8140
Print ISSN: 0021-9525
J Cell Biol (1992) 117 (3): 687–694.
Citation
Q Chen, C Linsenmayer, H Gu, T M Schmid, T F Linsenmayer; Domains of type X collagen: alteration of cartilage matrix by fibril association and proteoglycan accumulation.. J Cell Biol 1 May 1992; 117 (3): 687–694. doi: https://doi.org/10.1083/jcb.117.3.687
Download citation file:
Sign in
Don't already have an account? Register
Client Account
You could not be signed in. Please check your email address / username and password and try again.
Could not validate captcha. Please try again.
Sign in via your Institution
Sign in via your InstitutionSuggested Content
Email alerts
Advertisement
Advertisement