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MDR1a/1b gene silencing enhances drug sensitivity in rat fibroblast‐like synoviocytes
Author(s) -
Honjo Kuniaki,
Takahashi Kenji A.,
Mazda Osam,
Kishida Tsunao,
Shinya Masaharu,
Tokunaga Daisaku,
Arai Yuji,
Inoue Atsuo,
Hiraoka Nobuyuki,
Imanishi Jiro,
Kubo Toshikazu
Publication year - 2010
Publication title -
the journal of gene medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.689
H-Index - 91
eISSN - 1521-2254
pISSN - 1099-498X
DOI - 10.1002/jgm.1378
Subject(s) - gene silencing , fibroblast , chemistry , drug , sensitivity (control systems) , microbiology and biotechnology , cancer research , pharmacology , gene , medicine , biology , in vitro , biochemistry , electronic engineering , engineering
Background Drug resistance mediated by P‐glycoprotein (P‐gp) is one of the major reasons for the failure of rheumatoid arthritis (RA) therapy with disease modifying anti‐rheumatic drugs and glucocorticoids. In the present study, we aimed to investigate the in vitro effectiveness of small interfering RNA (siRNA) to render rat fibroblast‐like synoviocytes (FLS) susceptible to drugs. We also attempted the electroporation‐mediated transfer of siRNA against multidrug resistance (MDR) genes into rat knee joints. Methods FLS were transfected with siRNAs corresponding to MDR1a and MDR1b genes. FLS were treated with dexamethasone (DEX) and lipopolysaccharide. The mRNA and protein levels of tumor necrosis factor‐α, interleukin (IL)‐6 and IL‐1β were measured. Both siRNAs were co‐transduced into rat knee joints by an electroporation method and evaluated the target gene expressions in the synovium. Results Each siRNA could sequence‐specifically reduce the target gene expression by over 70% and effectively suppressed P‐gp expression and function in the FLS. Both gene expression and protein production of the inflammatory cytokines in the cells transfected with siRNA were reduced by a greater amount compared to in control cells. The in vivo electroporation‐mediated transduction of siRNA could significantly inhibit the target gene expressions. Conclusions MDR1a/1b gene silencing by siRNA could effectively inhibit P‐gp in rat FLS, resulting in a significant enhancement of the anti‐inflammatory effects of DEX. The in vivo siRNA transduction could successfully silence MDR gene expression in the rat synovium. These findings indicate that the siRNA targeting MDR gene could be a useful tool for treating refractory arthritis in RA. Copyright © 2009 John Wiley & Sons, Ltd.