Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Cartilage matrix resorption in skeletogenesis.

W Wu1, F Mwale, E Tchetina

  • 1Joint Diseases Laboratory, Shriners Hospitals for Children and Division of Surgical Research, Department of Surgery, McGill University, 1529 Cedar Avenue, Montreal, Quebec, Canada H3G 1A6.

Novartis Foundation Symposium
|March 30, 2001
PubMed
Summary

This study explores how the extracellular matrix of cartilage changes during skeletal development. As chondrocytes mature, they modify the composition of collagen and proteoglycan components. Specifically, collagen type IX loses a domain, and collagenase 3 (MMP13) is activated to cleave type II collagen and the remaining collagen IX domain. Aggrecan, a proteoglycan, is selectively retained in the matrix. Inhibiting collagenase activity stops chondrocyte maturation and reduces MMP13 expression. These findings suggest that proteolysis is essential for matrix resorption and chondrocyte differentiation. The study highlights the role of specific enzymes in shaping cartilage during development.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Tungsten accumulates in the intervertebral disc and vertebrae stimulating disc degeneration and upregulating markers of inflammation and pain.

European cells & materials·2021
Same author

Chitosan-based hydrogels supplemented with gelatine and Link N enhance extracellular matrix deposition by encapsulated cells in a degenerative intervertebral disc environment.

European cells & materials·2021
Same author

Link N suppresses interleukin-1β-induced biological effects on human osteoarthritic cartilage.

European cells & materials·2020
Same author

Short link N acts as a disease modifying osteoarthritis drug.

European cells & materials·2019
Same author

C2K77 ELISA detects cleavage of type II collagen by cathepsin K in equine articular cartilage.

Osteoarthritis and cartilage·2017
Same author

Human cartilaginous endplate degeneration is induced by calcium and the extracellular calcium-sensing receptor in the intervertebral disc.

European cells & materials·2016

Area of Science:

  • Cartilage biology within developmental biology
  • Matrix remodeling in skeletal development
  • Collagen and proteoglycan regulation in connective tissues

Background:

The structure of cartilage is shaped by dynamic changes in its extracellular matrix during skeletal development. While prior research has shown that chondrocytes produce and organize collagen and proteoglycan components, the specific mechanisms governing matrix turnover remain unclear. Established knowledge indicates that collagen types II and IX are foundational in immature cartilage. However, the transition to hypertrophic chondrocytes involves selective matrix modifications. No prior work had resolved how collagen domains are removed during maturation. This gap motivated investigations into proteolytic enzymes like MMP13. The role of proteoglycan retention in cartilage function is also not fully understood. Understanding these changes could clarify how cartilage supports bone formation. This paper addresses the molecular steps underlying matrix resorption in skeletogenesis.

Purpose Of The Study:

This study aimed to investigate how chondrocyte maturation affects the composition of the extracellular matrix during skeletal development. The specific problem addressed is the mechanism by which collagen and proteoglycan components are modified or removed as chondrocytes differentiate. The motivation stems from the need to understand how matrix remodeling supports skeletal growth. The authors sought to determine the role of proteolytic enzymes in this process. They focused on collagen types II and IX and the proteoglycan aggrecan. The study also aimed to identify the consequences of inhibiting matrix metalloproteinases. By examining these factors, the researchers hoped to clarify the molecular basis of cartilage matrix resorption. This could inform future studies on skeletal development and matrix diseases.

Keywords:
cartilage developmentmatrix metalloproteinaseskeletal growthcollagen degradation

Frequently Asked Questions

MMP13 is up-regulated during chondrocyte maturation and cleaves type II collagen and the COL2 domain of type IX collagen.

The NC4 domain of the alpha 1(IX) chain is lost as chondrocytes differentiate into hypertrophic cells.

Its removal is necessary for matrix remodeling and chondrocyte hypertrophy, as shown by inhibition experiments.

Aggrecan is selectively retained, suggesting it plays a structural role in maintaining matrix stability.

Related Experiment Videos

Main Methods:

The researchers used a combination of biochemical and molecular techniques to study chondrocyte matrix changes. They analyzed collagen and proteoglycan composition in developing cartilage. Immunostaining and proteomic methods were used to track collagen domain changes. Gene expression profiling was employed to identify up-regulated enzymes like MMP13. Inhibitors were applied to assess the effects of proteolysis on matrix remodeling. The study also included in situ hybridization to detect collagen and proteoglycan expression patterns. The researchers examined the structural organization of collagen fibrils using electron microscopy. These methods allowed them to link enzyme activity to matrix modifications in hypertrophic chondrocytes.

Main Results:

Collagen type IX loses its NC4 domain as chondrocytes mature into hypertrophic cells. MMP13 expression increases with the onset of type X collagen production. This enzyme cleaves type II collagen and the remaining COL2 domain of type IX collagen. Aggrecan is selectively retained in the extracellular matrix during this process. Inhibition of collagenase prevents chondrocyte hypertrophy and MMP13 gene expression. These findings suggest that proteolysis is essential for matrix resorption. The cleavage of collagen domains is tightly regulated during cartilage maturation. The selective retention of aggrecan indicates a functional role in matrix stability.

Conclusions:

The authors conclude that proteolysis, particularly by MMP13, is required for chondrocyte differentiation and matrix resorption. The cleavage of collagen domains is a key step in cartilage remodeling during skeletal development. Aggrecan retention suggests a structural role in the extracellular matrix. The study shows that matrix metalloproteinases are not only involved in degradation but also in tissue maturation. The findings support the idea that specific proteolytic events are necessary for cartilage development. The results do not suggest broader implications beyond the developmental context. The authors do not propose new drug targets or future directions. Their conclusions are limited to the molecular mechanisms observed in the study.

Inhibition prevents chondrocyte hypertrophy and reduces MMP13 gene expression.

Proteolysis, especially by MMP13, is required for chondrocyte differentiation and matrix resorption.