Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2017 Aug 31;18(1):377.
doi: 10.1186/s12891-017-1739-2.

Analysis of DNA methylation in chondrocytes in rats with knee osteoarthritis

Xinxin Wang  1   2 , Dezhi Tang  3 , Peng Shen  1   2 , Hao Xu  2 , Hongfu Qiu  1 , Tao Wu  1 , Xiang Gao  4
Affiliations

Analysis of DNA methylation in chondrocytes in rats with knee osteoarthritis

Xinxin Wang et al. BMC Musculoskelet Disord. .

Abstract

Background: Knee osteoarthritis (KOA) is a degenerative knee disease commonly found in the ageing population. DNA methylation works with histone acetylation to participate in aging. Alterations of DNA methylation may involve the joint chondrocyte degeneration in KOA. The aim of this study is to detect DNA methylation changes in chondrocytes of rats with KOA.

Methods: The rat KOA model was established with the Hulth method (n = 10), while rats receiving sham operation served as the control (n = 10). At 16 weeks after modeling, the knee joint tissue was collected from half of the rats in each group for Micro-CT scanning, Haematoxylin& Eosin (HE) staining, ABH/OG staining, immunohistochemistry for Bax, Bcl-2 and Fas, and TUNNEL staining. Meanwhile, the articular cartilage was collected from the other half to detect promoter methylation in target genes with the MethylTarget approach.

Results: Micro-CT scanning, HE staining, ABH/OG staining, immunohistochemistry, and TUNNEL staining all showed more severe cartilage injury in the KOA group than in the control group, indicating successful establishment of KOA model. The methylation rate in the KOA group was significantly decreased for C/ebpα-2 (within a CpG island -452 bp to the initiation codon on chromosome 1 91,363,511), Cdk2 (within a CpG island -55 bp to the initiation codon on chromosome 7 3,132,362), Bak1 (within a CpG island 6452 bp to the initiation codon on chromosome 20 5,622,277), and Fas (within a CpG island on the entire chromosome 1 gene), compared with the sham group (P = 0.005, 0.008, 0.022 and 0.027, respectively).

Conclusion: The chondrocyte apoptosis and significantly reduced methylation levels of C/ebpα-2, Cdk2, Bak1, and Fas may participate in the pathogenesis of KOA. However, the exact mechanisms remain to be determined.

Keywords: Bak; C/ebpα; Cdk2; Fas; Knee osteoarthritis; Methylation.

PubMed Disclaimer

Conflict of interest statement

Ethics approval and consent to participate

This study was approved by the Ethics Committee of Shanghai University of Traditional Chinese Medicine, China (No: SZY201507001). All procedures were in compliance with ethical guidelines for animal experiments. All efforts were made to minimize animal suffering.

Consent for publication

Not applicable

Competing interests

The authors declare that they have no competing interest with other people or any organizations.

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Figures

Fig. 1
Fig. 1
Images of Micro-CT scanning of the rat knee joint. a1 and b1 are reconstructed 3-dimensional images; a2 and b2 are images of coronal sections
Fig. 2
Fig. 2
HE staining of the knee joint. a, sham group; b, KOA model group
Fig. 3
Fig. 3
ABH/OG staining of the knee joint. a, sham group; b, KOA model group
Fig. 4
Fig. 4
Immunohistochemistry of Bax, Bcl-2 and Fas in the knee joint. a, sham group; b, KOA model group
Fig. 5
Fig. 5
TUNEL staining of the knee joint. a and c, nuclei of chondrocyte; b and d, nuclei of apoptotic cells
Fig. 6
Fig. 6
Methylation rate in the promoter region of C/ebpα (a), Cdk2 (b), Bak1 (c), and Fas (d)
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Crane DM, Oliver KS, Bayes MC. Orthobiologics and knee osteoarthritis: a recent literature review, treatment algorithm, and Pathophysiology discussion. Phys Med RehabilClin N Am. 2016;27(4):985–1002. doi: 10.1016/j.pmr.2016.07.004. - DOI - PubMed
    1. Reynard LN. Analysis of genetics and DNA methylation in osteoarthritis: what have we learnt about the disease? Semin Cell Dev Biol. 2017;62:57–66. doi: 10.1016/j.semcdb.2016.04.017. - DOI - PubMed
    1. Xu YS, Jiang XJ, Chen JM. A single nucleotide polymorphism of AIRE gene located in the 21q22.3 increases the risk of rheumatoid arthritis. Oncotarget. 2017, published online. doi:10.18632/oncotarget.17746. - PMC - PubMed
    1. Shao L, Fujii H, Colmegna I, et al. Deficiency of the DNA repair enzyme ATM in rheumatoid arthritis. J Exp Med. 2009;206(6):1435–1449. doi: 10.1084/jem.20082251. - DOI - PMC - PubMed
    1. Liang M, Russell G, Hulley PA. Bim, Bak, and Bax regulate osteoblast survival. J Bone Miner Res. 2008;23(5):610–620. doi: 10.1359/jbmr.080106. - DOI - PMC - PubMed