Related Experiment Video
Updated: Aug 14, 2026
Flow Cytometry Analysis of Immune Cell Subsets within the Murine Spleen, Bone Marrow, Lymph Nodes and Synovial Tissue in an Osteoarthritis Model
Published on: April 24, 2020
The identification of differentially expressed microRNA in osteoarthritic tissue that modulate the production of
S W Jones1, G Watkins, N Le Good
1Disease Science, Respiratory and Inflammation Research Area, AstraZeneca Alderley Park, Macclesfield SK10 4TG, United Kingdom. simon.w.jones@astrazeneca.com
Objective:
To identify differentially expressed microRNAs (miRNAs) in human osteoarthritic (OA) cartilage and bone tissue and to determine their relevance to chondrocyte function.
Methods:
Cartilage and bone was obtained from OA patients who underwent total knee joint replacement surgery or from post-mortem patients with no previous history of OA. MiRNA expression was quantified by real-time PCR (RT-PCR). Functional pathway analysis of miRNA was performed using Ingenuity Pathway Analysis. Primary chondrocytes were isolated by collagenase digestion and transfected with miRNA mimics and miRNA inhibitors using cationic lipid. Tumour Necrosis Factor-alpha (TNF-alpha) and Matrix metalloprotease 13 (MMP13) protein levels were measured by Enzyme-Linked ImmunoSorbent Assay (ELISA).
Results:
In total we identified 17 miRNA that showed greater than 4-fold differential expression between OA and normal cartilage, and 30 miRNA that showed greater than 4-fold differential expression in OA bone. Functional pathway analysis of the predicted gene targets for miR-9, miR-98, which were upregulated in both OA bone and cartilage tissue, and miR-146, which was downregulated in OA cartilage, suggested that these miRNA mediate inflammatory functions and pathways. Over-expression of miR-9, miR-98 or miR-146 in isolated human chondrocytes reduced interleukin-1 beta (IL-1 beta) induced TNF-alpha production. Furthermore, inhibition and over-expression of miR-9 modulated MMP13 secretion.
Conclusions:
We have identified a number of differentially expressed miRNAs in late-stage human OA cartilage and bone. Functional analysis of miR-9, miR-98 and miR-146 in primary chondrocytes suggests a role in mediating the IL-1 beta induced production of TNF-alpha. MiR-9, upregulated in OA tissue, was found to inhibit secretion of the collagen type II-targeting metalloproteinase MMP13 in isolated human chondrocytes.
Insights
Researchers identified differentially expressed microRNAs (miRNAs) in osteoarthritis (OA) tissues. Specific miRNAs like miR-9, miR-98, and miR-146 influence inflammatory pathways and chondrocyte function, impacting TNF-alpha and MMP13 levels in OA.
Area of Science:
- Molecular Biology
- Biochemistry
- Genetics
Background:
- Osteoarthritis (OA) is a degenerative joint disease characterized by cartilage breakdown and inflammation.
- MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression and play roles in various cellular processes, including inflammation and matrix degradation.
Purpose of the Study:
- To identify differentially expressed miRNAs in human osteoarthritic (OA) cartilage and bone.
- To investigate the functional relevance of these miRNAs in chondrocyte function and OA pathogenesis.
Main Methods:
- miRNA expression profiling using real-time PCR (RT-PCR) on OA and normal cartilage and bone tissues.
- Functional pathway analysis using Ingenuity Pathway Analysis.
- In vitro studies involving transfection of primary human chondrocytes with miRNA mimics/inhibitors and measurement of inflammatory markers (TNF-alpha) and matrix metalloproteinase 13 (MMP13).
Main Results:
- Seventeen miRNAs were differentially expressed in OA cartilage, and 30 in OA bone compared to normal tissues.
- Upregulated miR-9 and miR-98, and downregulated miR-146 were identified in OA tissues.
- Overexpression of miR-9, miR-98, or miR-146 reduced IL-1 beta-induced TNF-alpha production in chondrocytes.
- miR-9 modulated MMP13 secretion, indicating a role in matrix degradation.
Conclusions:
- A distinct set of miRNAs are differentially expressed in late-stage human OA cartilage and bone.
- miR-9, miR-98, and miR-146 are implicated in mediating inflammatory responses in OA, specifically the IL-1 beta-induced TNF-alpha production.
- miR-9, found to be upregulated in OA tissue, inhibits the secretion of MMP13, a key enzyme involved in collagen type II degradation.
