Contribution of H3K4 methylation by SET-1A to interleukin-1-induced cyclooxygenase 2 and inducible nitric oxide synthase expression in human osteoarthritis chondrocytes.

Abstract

OBJECTIVE:

To investigate the role of histone H3 lysine 4 (H3K4) methylation in interleukin-1β (IL-1β)-induced cyclooxygenase 2 (COX-2) and inducible nitric oxide synthase (iNOS) expression in human osteoarthritic (OA) chondrocytes.

METHODS:

Chondrocytes were stimulated with IL-1, and the expression of iNOS and COX-2 messenger RNA and proteins was evaluated by real-time reverse transcriptase-polymerase chain reaction analysis and Western blotting, respectively. H3K4 methylation and the recruitment of the histone methyltransferases SET-1A and MLL-1 to the iNOS and COX-2 promoters were evaluated using chromatin immunoprecipitation assays. The role of SET-1A was further evaluated using the methyltransferase inhibitor 5'-deoxy-5'-(methylthio)adenosine (MTA) and gene silencing experiments. SET-1A level in cartilage was determined using immunohistochemistry.

RESULTS:

The induction of iNOS and COX-2 expression by IL-1 was associated with H3K4 di- and trimethylation at the iNOS and COX-2 promoters. These changes were temporally correlated with the recruitment of the histone methyltransferase SET-1A, suggesting an implication of SET-1A in these modifications. Treatment with MTA inhibited IL-1-induced H3K4 methylation as well as IL-1-induced iNOS and COX-2 expression. Similarly, SET-1A gene silencing with small interfering RNA prevented IL-1-induced H3K4 methylation at the iNOS and COX-2 promoters as well as iNOS and COX-2 expression. Finally, we showed that the level of SET-1A expression was elevated in OA cartilage as compared with normal cartilage.

CONCLUSION:

These results indicate that H3K4 methylation by SET-1A contributes to IL-1-induced iNOS and COX-2 expression and suggest that this pathway could be a potential target for pharmacologic intervention in the treatment of OA and possibly other arthritic diseases.

• Authors: Fatima Ezzahra El Mansouri, Nadir Chabane, Nadia Zayed, Mohit Kapoor, Mohamed Benderdour, Johanne Martel-Pelletier, Jean-Pierre Pelletier, Nicolas Duval, Hassan Fahmi
• Journal: Arthritis and rheumatism (Arthritis Rheum) Vol. 63 Issue 1 Pg. 168-79 (Jan 2011) ISSN: 1529-0131 [Electronic] United States
• PMID: 20862685 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2011 by the American College of Rheumatology.

Chemical References

• Interleukin-1
• RNA, Messenger
• Nitric Oxide Synthase Type II
• Cyclooxygenase 2
• Histone-Lysine N-Methyltransferase
• Setd1A protein, human

Topics

• Adult
• Aged
• Blotting, Western
• Cartilage (drug effects, metabolism)
• Cells, Cultured
• Chondrocytes (drug effects, metabolism)
• Chromatin Immunoprecipitation
• Cyclooxygenase 2 (genetics, metabolism)
• Gene Expression (drug effects)
• Gene Silencing
• Histone-Lysine N-Methyltransferase (genetics, metabolism)
• Humans
• Immunohistochemistry
• Interleukin-1 (metabolism, pharmacology)
• Methylation
• Middle Aged
• Nitric Oxide Synthase Type II (genetics, metabolism)
• Osteoarthritis (genetics, metabolism)
• RNA, Messenger (genetics, metabolism)
• Reverse Transcriptase Polymerase Chain Reaction
• Statistics, Nonparametric