The changing expressions of transforming growth factor-beta signaling pathway in the subchondral bone in experimental early traumatic osteoarthritis

Abstract

Objective To study the expressions of transforming growth factor-beta(TGF-β) signaling pathway in the subchondral bone in experimental early traumatic osteoarthritis to understand the role of TGF-β signaling pathway in the pathogenesis of osteoarthritis.Methods Thirty male SD rats were randomized into 2 equal groups.In the experimental group,the medial meniscus and the medial collateral ligament (MCL)of the right knee joint were exsected while the articular capsule was only cut open in the control group.Samples of the right knee joint were harvested at 1,2 and 4 weeks postsurgery.Total RNA of the subchondral bone was extracted and then hybridized to Agilent Whole Rat Genome Microarray.Analyses of the pathway and differentially expressed genes were conducted to explore changes in the expression of the TGF-β signaling pathway.Results Significant differences in the expression of TGF-β signaling pathway between the experimental group and the control group were found at 1 and 2 weeks postsurgery (P ＜ 0.05),but not at 4 weeks postsurgery (P ＞ 0.05).The following differentially expressed genes were found to be involved in the changing expressions of TGF-β signaling pathway: activin A receptor-I,activin A receptor-2b,anti-mullerian hormone,bone morphogenetic protein-4,bone morphogenetic protein-5,bone morphogenetic protein receptor-la,cartilage oligomeric matrix protein,decorin,interferon gamma,inhibin beta-A,noggin,SMAD specific E3 ubiquitin protein ligase-2,transforming growth factor-beta 1,transforming growth factor-beta 2,transforming growth factor-betareceptor 1,thrombospondin-2,thrombospondin-4precursor,inhibitorofDNAbinding4andFYVEdomain containing 16 (predicted) similar to Zinc finger.Conclusions TGF-β signaling pathway may play an important role in the pathogenesis of experimental early traumatic osteoarthritis in a time-dependent manner. Key words: Transforming growth factor beta; Osteoarthritis; Oligonucleotide array sequence analysis; Cartilage, articular