Vol.23 No.4

Original Article

Overexpression of microRNA-223 in rheumatoid arthritis synovium controls osteoclast differentiation

Authors

Hayatoshi Shibuya1 , Tomoyuki Nakasa1 , Nobuo Adachi1 , Yoshihiko Nagata1 , Masakazu Ishikawa1 , Masataka Deie1 , Osami Suzuki1 , Mitsuo Ochi1

  • Programs for Applied Biomedicine, Division of Clinical Medical Science, Department of Orthopedic Surgery, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, Japan
Received:

28 March 2012

Accepted:

14 June 2012

Published online:

19 August 2012

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Abstract

Objectives MicroRNAs, a class of noncoding RNAs, play roles in human diseases. MicroRNA-223 (miR-223) is reported to play critical roles in osteoclastogenesis. The purpose of this study was to analyze the expression pattern of miR-223 in rheumatoid arthritis (RA) synovium and examine the suppression of osteoclastogenesis from human peripheral blood mononuclear cells (PBMC) by overexpression of miR-223.
Methods Expression of miR-223 in synovium from RA patients was analyzed by quantitative reverse transcription polymerase chain reaction (RT-PCR) and section in situ hybridization. MiR-223 was overexpressed in an osteoclastogenesis coculture system with PBMC and RA synovial fibroblast. At 3 weeks after transfection of double-stranded miR-223, the formation of tartrate-resistant acid phosphatase (TRAP)-stained multinucleated cells was analyzed to evaluate the inhibitory effect of miR-223 on osteoclastogenesis.
Results MiR-223 was more highly expressed in RA synovium than in osteoarthritis (OA) synovium due to the increased number of miR-223-positive cells in RA synovium. MiR-223 was expressed in the superficial and sublining layers, and macrophages, monocytes, and CD4 T cells also expressed miR-223. The number of TRAPpositive multinucleated cells was significantly decreased by overexpression of miR-223 in a dose-dependent manner. The expression of osteoclastogenesis marker genes was significantly down-regulated by miR-223 overexpression.
Conclusion MiR-223 is intensely expressed in RA synovium, and overexpression of miR-223 suppresses osteoclastogenesis in vitro. This study demonstrates the possibility of gene therapy with miR-223 to treat bone destruction in RA patients.

Key words

MicroRNA, RA, Human peripheral blood mononuclear cells, RA synovial fibroblast, Osteoclast differentiation