Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.


Mir-19b Regulates TLR2 Expression in Rheumatoid Arthritis Fibroblast-Like Synoviocytes.

Philippe3,  Lucas, Suffert1,  Guillaume, Alsaleh3,  Ghada, Theulin3,  Arnaud, Gottenberg3,  Jacques Eric, Sibilia3,  Jean, Pfeffer2,  Sebastien

Architecture et Réactivité de l'ARN, Université de Strasbourg, Institut de Biologie Moléculaire et Cellulaire du CNRS, Strasbourg, France, Metropolitan
Architecture et Reactivite de l'ARN, Universite de Strasbourg, Institut de Biologie Moleculaire et Cellulaire du CNRS, Strasbourg, France, Metropolitan
Laboratoire de Physiopathologie des Arthrites, EA4438, Faculté de Pharmacie, 74 Route du Rhin, Illkirch-Graffenstaden, France, Metropolitan

Background:

Rheumatoid arthritis (RA) is a chronic autoimmune disease of which the main characteristic is irreversible joint destruction. An excessive stimulation of resident cells such as fibroblast-like synoviocytes (FLS) seems to be a fundamental event. This activation is in part due to microbial components such as PAMPs (Pathogen Associated Molecular Patterns) or DAMPs (damage associated molecular patterns) that activate cells by interacting with Pattern Recognition Receptors (PRRs) such as Toll like receptors (TLRs). Their activation triggers the transcription of numerous genes coding for pro-inflammatory cytokines and metalloproteases implicated in cartilage and bone destruction. MicroRNAs (miRNA) are small non-coding RNA that have emerged as key players in the regulation of translation and degradation of target mRNAs. The aim of this work was to evaluate their potential involvement in the control of TLR expression by RA FLS.We focused on TLR2 expression which is up-regulated in RA synovium.

Materials and Methods:

FLS were obtained from RA patients at the time of joint surgery.TLR2 mRNA and protein expression was assessed by RT-qPCR and western blot after stimulation of RA FLS with BLP, a ligand of TLR2. MiRNAs expression was analyzed using a microarray-based approach and confirmed by RT-qPCR. Transfection of FLS was performed using the AMAXA nucleofactor kit II (c) system. Identification of 19b targets was assessed by the luciferase assay using the psiCHECK™-2 Vectors. IL-6 secretion was evaluated using the ELISA sandwich method.

Results:

We first showed that RA FLS expressed constitutively TLR2 and that TLR2 expression was up-regulated in response to BLP. Using a miRNA microarray analysis, we identified the downregulation of miR-19b which was predicted to target TLR2 mRNA. Down regulation of miR-19b was confirmed by qRT-PCR. Transfection of RA FLS with miR-19b mimic decreased TLR2 expression. Using a luciferase assay, we also showed that miR-19b targets directly TLR2 mRNA 3'UTR. In addition, direct targeting of TLR2 mRNA by 19b mimic inhibited IL-6 secretion by BLP activated RA FLS.

Conclusion:

Together, these data demonstrated a critical functional link between miR-19b, TLR2 expression and IL6 secretion by RA FLS, which could play an important role in RA inflammation.

To cite this abstract, please use the following information:
Philippe, Lucas, Suffert, Guillaume, Alsaleh, Ghada, Theulin, Arnaud, Gottenberg, Jacques Eric, Sibilia, Jean, et al; Mir-19b Regulates TLR2 Expression in Rheumatoid Arthritis Fibroblast-Like Synoviocytes. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :858
DOI: 10.1002/art.28626

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