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Matrix metalloproteinase-1, -3, -13 and aggrecanase-1 and -2 are differentially expressed in experimental
G Bluteau1, T Conrozier, P Mathieu
1Institut de Biologie et Chimie des Protéines, UMR 5086 CNRS/Université Claude Bernard Lyon I, 7 passage du Vercors, 69367 Lyon Cedex 07, France.
Abstract:
The aim of this study was to characterize the cellular phenotypes of articular cartilage and meniscus in rabbits with experimentally induced osteoarthritis (OA), by histological and molecular biological techniques. OA was induced by severing the anterior cruciate ligament of the knee and rabbits were killed 2, 4 or 9 weeks following surgery. Our histological observations show a progressive destruction of extracellular matrix in both tissues. To determine whether these morphological changes could be related to alterations in the regulation of gene expression for a subset of relevant molecules, levels of mRNA for proteinases and one inhibitor (MMP-1, -3 and -13, aggrecanase-1 and -2 and TIMP-1), matrix molecules and one chaperone (type II and X collagens, aggrecan, osteonectin, betaig-h3 and BiP) were assessed by reverse transcription-polymerase chain reaction. Our results indicate that for most markers expression profiles were similar in both tissues. In particular, matrix protein gene expression remained stable or varied little during progression of OA, suggesting a poor repair capacity of the tissues. MMP gene expression increased rapidly whereas aggrecanase gene expression remained stable. These findings suggest that differential regulation of mRNA levels of MMP-1, -3 and -13 on the one hand and aggrecanase-1 and -2 on the other, occurs during OA.
Insights
This study reveals that osteoarthritis progression in rabbits involves matrix destruction and stable matrix protein gene expression, indicating poor tissue repair. Matrix metalloproteinase (MMP) gene expression rises, while aggrecanase expression remains steady.
Area of Science:
- Biochemistry
- Molecular Biology
- Orthopedics
Background:
- Osteoarthritis (OA) is a degenerative joint disease characterized by cartilage and meniscus breakdown.
- Understanding cellular phenotypes and gene expression is crucial for OA research.
Purpose of the Study:
- To characterize cellular phenotypes in rabbit articular cartilage and meniscus during experimentally induced OA.
- To investigate alterations in gene expression of proteinases, matrix molecules, and chaperones.
Main Methods:
- Experimental osteoarthritis (OA) induced by anterior cruciate ligament transection in rabbits.
- Histological analysis to observe tissue destruction.
- Reverse transcription-polymerase chain reaction (RT-PCR) to quantify mRNA levels of specific genes (MMPs, aggrecanases, collagens, etc.).
Main Results:
- Progressive extracellular matrix destruction observed in both cartilage and meniscus.
- Stable mRNA expression for most matrix proteins, suggesting limited repair capacity.
- Rapid increase in matrix metalloproteinase (MMP) gene expression, contrasting with stable aggrecanase gene expression.
Conclusions:
- Differential regulation of MMP and aggrecanase mRNA levels occurs during OA progression.
- The findings highlight a poor intrinsic repair capacity of articular cartilage and meniscus in OA.
- This study provides insights into the molecular mechanisms underlying OA pathogenesis.