ACR Meeting Abstracts

ACR Meeting Abstracts

  • Meetings
    • ACR Convergence 2024
    • ACR Convergence 2023
    • 2023 ACR/ARP PRSYM
    • ACR Convergence 2022
    • ACR Convergence 2021
    • ACR Convergence 2020
    • 2020 ACR/ARP PRSYM
    • 2019 ACR/ARP Annual Meeting
    • 2018-2009 Meetings
    • Download Abstracts
  • Keyword Index
  • Advanced Search
  • Your Favorites
    • Favorites
    • Login
    • View and print all favorites
    • Clear all your favorites
  • ACR Meetings

Abstract Number: 2519

IL-1β and TNF-α Regulate the Global and Locus-Specific hydroxymethylation  of Genomic DNA by Modulating the Expression and Activity of Tet-1 in Human OA Chondrocytes

Abdul Haseeb1 and Tariq M. Haqqi2, 1Medicine/Rheumatology, Case Western Reserve University, Cleveland, OH, 2Medicine/Rheumatology/Haman 586, Metro Health Medical Center, Cleveland, OH

Meeting: 2012 ACR/ARHP Annual Meeting

Keywords: cartilage, chondrocytes, epigenetics and matrix metalloproteinase (MMP), OA

  • Tweet
  • Click to email a link to a friend (Opens in new window) Email
  • Click to print (Opens in new window) Print
Session Information

Title: Biology and Pathology of Bone and Joint: Regulation of Bone Cells

Session Type: Abstract Submissions (ACR)

Background/Purpose:

5-hydroxymethylcytosine (5-hmC), which is formed by the oxidation of 5-methylcytosine (5-mC), is a recently discovered epigenetic mark and is highest in brain and in embryonic stem cells. There have been reports supporting the notion that generation of 5-hmC may be a mechanism of DNA demethylation and thus important in the regulation of gene expression. In the present study we investigated the global and locus-specific 5-hmC content in the promoter region of MMP-3 gene and its expression in human OA chondrocytes. We also investigated the effect of IL-1β and TNF-α on the level of 5-hmC, expression and activity of the enzymes responsible for hydroxylation of 5-mC to generate 5-hmC and MMP-3 in human chondrocytes.

Methods:

Primary human chondrocytes were isolated from the deep zone of the cartilage obtained from OA patients who underwent total joint replacement (n=8) and were treated with IL-1β and TNF-α for 48 hr. Global 5-hmC content in genomic DNA was quantified using a 5-hmC-specific ELISA (Epigentek, Farmingdale, NY). Total TET methylcytosine dioxygenase (Tet) activity was determined by an ELISA based activity assay kit (Epigentek). Tet-1, Tet-2 and Tet-3 and MMP-3 mRNA levels were quantitated by using the TaqMan assays (Applied Biosystems, Carlsbad, CA). Locus specific 5-mC and 5-hmC content in the MMP-3 promoter was examined by using EpiMark 5-mC and 5-hmC analysis kit (NEB, Ipswich, MA), which uses methylation sensitive HpaII and glucosylation sensitive enzyme MspI following the treatment of genomic DNA with T4-β-glucosyl transferase, and PCR using specific primers. Data were derived using Origin 6.1 software and P<0.05 was considered significant.

Results:

The global content of 5-hmC in human chondrocytes was found to be 0.1-0.2% of the total genome. There was approximately 70% decrease (P<0.05) in the 5-hmC content upon treatment with IL-1β in combination with TNF-α for 48 hrs. This correlated with the reduction of Tet enzyme activity in chondrocytes after treatment with IL-1β and IL-1β + TNF-α. There was a significant (upto 20 fold) reduction in the level of Tet-1 mRNA expression while expression of Tet-3 mRNA was increased slightly (2-3 fold). The level of Tet-2 mRNA expression did not change upon treatment with the cytokines. MMP-3 promoter contained a high percentage (~70%) of 5-hmC at HpaII locus in deep zone chondrocytes and these chondrocytes showed a dramatic (40 fold) increase in the expression level of MMP-3 upon treatment with IL-1β and TNF-α.

Conclusion:

Our results demonstrate for the first time the presence of a significant amount of 5-hmC in human chondrocyte DNA. We also for the first time show that the 5-hmC content of the genomic DNA can be modulated by treatment with proinflammatory cytokines IL-1β and TNF-α in a short span of 48 hrs. The changes in 5-hmC levels correlated with the Tet-1 gene expression level and Tet enzyme activity in chondrocytes stimulated with IL-1β + TNF-α. Our data also demonstrate that the expression of MMP-3 was significantly (P <0.005) increased in chondrocytes with high content of 5-hmC in its promoter region. Taken together our novel data identify an important role for DNA hydroxymethylation in cartilage and may be important in understanding the mechanism and pathogenesis of OA.


Disclosure:

A. Haseeb,
None;

T. M. Haqqi,
None.

  • Tweet
  • Click to email a link to a friend (Opens in new window) Email
  • Click to print (Opens in new window) Print

« Back to 2012 ACR/ARHP Annual Meeting

ACR Meeting Abstracts - https://acrabstracts.org/abstract/il-1%ce%b2-and-tnf-%ce%b1-regulate-the-global-and-locus-specific-hydroxymethylation-of-genomic-dna-by-modulating-the-expression-and-activity-of-tet-1-in-human-oa-chondrocytes/

Advanced Search

Your Favorites

You can save and print a list of your favorite abstracts during your browser session by clicking the “Favorite” button at the bottom of any abstract. View your favorites »

All abstracts accepted to ACR Convergence are under media embargo once the ACR has notified presenters of their abstract’s acceptance. They may be presented at other meetings or published as manuscripts after this time but should not be discussed in non-scholarly venues or outlets. The following embargo policies are strictly enforced by the ACR.

Accepted abstracts are made available to the public online in advance of the meeting and are published in a special online supplement of our scientific journal, Arthritis & Rheumatology. Information contained in those abstracts may not be released until the abstracts appear online. In an exception to the media embargo, academic institutions, private organizations, and companies with products whose value may be influenced by information contained in an abstract may issue a press release to coincide with the availability of an ACR abstract on the ACR website. However, the ACR continues to require that information that goes beyond that contained in the abstract (e.g., discussion of the abstract done as part of editorial news coverage) is under media embargo until 10:00 AM ET on November 14, 2024. Journalists with access to embargoed information cannot release articles or editorial news coverage before this time. Editorial news coverage is considered original articles/videos developed by employed journalists to report facts, commentary, and subject matter expert quotes in a narrative form using a variety of sources (e.g., research, announcements, press releases, events, etc.).

Violation of this policy may result in the abstract being withdrawn from the meeting and other measures deemed appropriate. Authors are responsible for notifying colleagues, institutions, communications firms, and all other stakeholders related to the development or promotion of the abstract about this policy. If you have questions about the ACR abstract embargo policy, please contact ACR abstracts staff at [email protected].

Wiley

  • Online Journal
  • Privacy Policy
  • Permissions Policies
  • Cookie Preferences

© Copyright 2025 American College of Rheumatology