Elsevier

Osteoarthritis and Cartilage

Volume 20, Issue 9, September 2012, Pages 1029-1038
Osteoarthritis and Cartilage

Identification of the pathogenic pathways in osteoarthritic hip cartilage: commonality and discord between hip and knee OA

https://doi.org/10.1016/j.joca.2012.05.006Get rights and content
Under an Elsevier user license
open archive

Summary

Objective

To define for the first time the transcriptomes of normal and end-stage osteoarthritis (OA) hip cartilage.

Materials and methods

RNA was isolated from cartilage within 2 h of joint replacement surgery. Gene expression was analyzed using Agilent GeneSpring GX 11 following hybridization to Illumina Human HT-12 V3 microarrays. Real-time reverse-transcription polymerase chain reaction (RT-PCR) was used to validate the expression of six genes identified by microarray as differentially expressed. Gene Set Enrichment Analysis (GSEA) and Ingenuity Pathway Analysis (IPA) were used to investigate enriched functions or canonical pathways amongst differentially expressed genes respectively.

Results

In total we identified 998 differentially expressed genes (fold change  ±1.5, P-value  0.01) between neck of femur fracture (NOF) (n = 10) and OA hip (n = 9) patient cartilage. These differentially expressed genes were enriched within 71 canonical pathways. A comparison between a comparable knee dataset20 only identified 229 genes similarly differentially expressed although remarkably 34 canonical pathways overlapped between experiments.

Conclusions

This study is the first to report a comprehensive gene expression analysis of human hip OA cartilage compared to control (NOF) cartilage at the whole-genome level. Our differential gene expression dataset shows excellent correlation with similar defined studies using comparable tissue but reveals discord between hip and knee OA at the individual gene status but with commonality with regards the molecular pathways involved.

Keywords

Chondrocytes
Cartilage
Microarray
Gene expression profiling
Pathway analysis

Cited by (0)