Overexpression of microRNA-223 in rheumatoid arthritis synovium controls osteoclast differentiation.
OBJECTIVE
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 TRAP-positive 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.


CONCLUSIONS
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.
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. hshibuya8@gmail.com
Hayatoshi
H
Shibuya
Tomoyuki
T
Nakasa
Nobuo
N
Adachi
Yoshihiko
Y
Nagata
Masakazu
M
Ishikawa
Masataka
M
Deie
Osami
O
Suzuki
Mitsuo
M
Ochi
D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D002454:Cell Differentiation / Q000235:genetics*; D015536:Down-Regulation / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D008875:Middle Aged; D010010:Osteoclasts / Q000378:metabolism / Q000473:pathology*; D013583:Synovial Membrane / Q000378:metabolism* / Q000473:pathology
D035683:MicroRNAs; C525067:MIR223, human