Abstract | INTRODUCTION: Abnormal toll-like receptor (TLR)3 signaling plays an indispensable role in pathogenesis of both experimental and human rheumatoid arthritis, and microRNAs ( miRNAs) might orchestrate this signaling pathway. This study was performed to determine the relationship between miR-26a and TLR3 in rat macrophages and to observe effects of miR-26a mimic on pristane induced arthritis (PIA) in rats. METHODS: Dual luciferase reporter assay was used to validate the direct interaction between miR-26a (a candidate miRNA to target tlr3 mRNA) and tlr3 3'UTR. MiR-26a regulation on TLR3 gene expression was determined using RT-qPCR and Western blotting after miR-26a mimics and inhibitors were transfected into rat macrophage line NR8383 cells. Poly I:C (TLR3 ligand) was used to trigger TLR3 activation, and mRNA expression of its downstream cytokines interferon (ifn)-β and tumor necrosis factor (tnf)-α was accordingly detected to determine the regulation of TLR3 signaling. Expressions of TLR3 and miR-26a were detected during rat bone marrow derived macrophage (BMDM) induction, in pristane stimulated NR8383 cells and spleens from methotrexate (MTX) treated PIA rats. A miR-26a mimic was administrated intraperitoneally to PIA rats, and arthritis severity was evaluated by macroscopic or microscopic observations. RESULTS: Direct target relationship between miR-26a and tlr3 mRNA in rats was confirmed. Modifications of miR-26a function by transfection of miR-26a mimics and inhibitors exhibited corresponding repression and augmentation of TLR3 and its signaling downstream cytokine expressions in NR8383 cells. The alteration of miR-26a expression was negatively related with TLR3 expression during BMDM induction, in pristane-primed NR8383 cells and PIA rat spleens. Moreover, both abnormal expressions were rescued in MTX treated arthritis rat spleens. The miR-26a mimic treatment displayed the depression of TLR3 expression and ameliorated the disease severity in the rats with pristane induced arthritis. CONCLUSIONS: MiR-26a negatively regulates TLR3 signaling via targeting of TLR3 itself in rat macrophages, and this finding provides a novel insight into abnormal TLR3 overexpression during experimental arthritis.
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Authors | Congshan Jiang, Wenhua Zhu, Jing Xu, Bo Wang, Weikun Hou, Rui Zhang, Nannan Zhong, Qilan Ning, Yan Han, Hongchuan Yu, Jian Sun, Liesu Meng, Shemin Lu |
Journal | Arthritis research & therapy
(Arthritis Res Ther)
Vol. 16
Issue 1
Pg. R9
(Jan 14 2014)
ISSN: 1478-6362 [Electronic] England |
PMID | 24423102
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Immunosuppressive Agents
- MIRN26 microRNA, rat
- MicroRNAs
- TLR3 protein, rat
- Terpenes
- Toll-Like Receptor 3
- pristane
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Topics |
- Animals
- Arthritis, Experimental
(genetics, metabolism)
- Arthritis, Rheumatoid
(genetics, metabolism)
- Blotting, Western
- Gene Expression Regulation
(physiology)
- Immunosuppressive Agents
(toxicity)
- Macrophages
(metabolism)
- MicroRNAs
(genetics, metabolism)
- Rats
- Real-Time Polymerase Chain Reaction
- Terpenes
(toxicity)
- Toll-Like Receptor 3
(biosynthesis, genetics)
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