Related Experiment Video
Updated: Jul 7, 2026
07:10
An Ex Vivo Tissue Culture Model of Cartilage Remodeling in Bovine Knee Explants
Published on: November 3, 2019
Differential Toll-like receptor-dependent collagenase expression in chondrocytes
Q Zhang1, W Hui, G J Litherland
1Musculoskeletal Research Group, Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne, UK.
Annals of the Rheumatic Diseases
|February 9, 2008
Summary
Toll-like receptor (TLR) activation in osteoarthritis chondrocytes upregulates collagenase genes, with specific ligands inducing cartilage breakdown. Modulating TLR signaling may offer a new therapeutic approach for osteoarthritis treatment.
Area of Science:
- Immunology
- Biochemistry
- Orthopedics
Background:
- Osteoarthritis (OA) is characterized by cartilage degradation.
- Chondrocytes play a key role in maintaining cartilage homeostasis.
- Toll-like receptors (TLRs) are involved in immune responses and inflammation.
Purpose of the Study:
- To investigate the catabolic response of osteoarthritic chondrocytes to Toll-like receptor (TLR) ligands.
- To explore the potential of TLR-mediated signaling as a therapeutic target for OA.
Main Methods:
- Assessed collagenase (MMP1 and MMP13) induction by TLR ligands in chondrocytes using real-time RT-PCR.
- Confirmed TLR signaling pathway activation and involvement in collagenase induction via immunoblotting, pathway inhibitors, and siRNA.
- Compared TLR expression in normal and OA cartilage using real-time RT-PCR.
Main Results:
- Ligands for TLR6/2 and TLR3 significantly upregulated MMP1 and MMP13, respectively.
- Collagenolysis was induced by TLR1/2 and TLR6/2 ligands in a cartilage resorption assay.
- TLR2 was downregulated and TLR3 upregulated in OA cartilage compared to normal cartilage.
Conclusions:
- Activation of chondrocyte TLRs leads to differential collagenase gene activation.
- TLR1/2 or TLR6/2 ligand treatment resulted in collagen resorption.
- Modulating TLR-mediated signaling presents a potential therapeutic strategy for OA.
Related Concept Videos
01:23Role of Matrix Metalloproteases in Degradation of ECM
Matrix metalloproteases (MMPs) are enzymes involved in the hydrolysis of proteins and glycoproteins of the extracellular matrix. MMPs are essential for the migration and proliferation of cells through the dense matrix network, throughout embryonic development, and throughout morphogenesis. The first MMP activity discovered was a collagenase in a tadpole's tail undergoing metamorphosis. The active collagen deposition and modifications lead to the morphogenesis of tadpoles into the adult body.
A...
A...
01:11Fibril-associated Collagen
Fibril-associated collagens are a type of collagens present in the extracellular matrix with interrupted triple helices or FACIT (Fibril-associated collagens interrupted triple-helices). FACIT help connect and attach the collagen fibrils with each other as well as with other proteins of the extracellular matrix.
For example, the type II collagen fibrils in cartilage have covalently bound type IX fibril-associated collagens at regular intervals. Other types of fibril-associated collagens are...
For example, the type II collagen fibrils in cartilage have covalently bound type IX fibril-associated collagens at regular intervals. Other types of fibril-associated collagens are...