[Locally administered lentivirus-mediated siRNA inhibits wear debris-induced inflammation].
OBJECTIVE
To determine the safety and efficacy of local administration of lentivirus-mediated small interfering RNA (siRNA) targeting tumor necrosis factor-alpha (TNF-alpha) in murine air pouch model.


METHODS
From May 2007 to April 2008 a siRNA targeting TNF-alpha and a missense siRNA were designed, and recombine lentivirus which coexpressed the green fluorescent protein (GFP) as a marker gene was constructed. Air pouches were established and stimulated by Ti-6Al-4V particles. Pouches were divided into 3 groups randomly. Lentivirus-mediated siRNA targeting TNF-alpha (TNF-alpha group) or lentivirus-mediated missense siRNA (MS group), or virus-free saline (control group) were injected into pouches respectively. Pouch membrane, peripheral blood, heart, liver, spleen, kidney, lung and brain were harvested at 28 d after transfection, and assayed for markers of inflammation using histological, molecular, immunological techniques and Xenogen in vivo imaging system (IVIS) 50 vivo bioluminescent assay system.


RESULTS
Xenogen IVIS 50 vivo image revealed strong expression of GFP localized in pouch areas and no expression in other parts of mice both in TNF-alpha group and MS group at 4 weeks after transfection, while no expression of GFP was found in control group. By RT-PCR and ELISA, the mRNA and protein levels of TNF-alpha in TNF-alpha group decreased by 81.6% and 82.6% respectively compared to control group (P < 0.01), and decreased by 78.9% and 84.0% respectively compared to MS group (P < 0.01), whereas TNF-alpha level in peripheral blood, heart, liver, spleen, kidney, lung and brain remained invariant (P > 0.05). Less inflammatory responses (thinner pouch membrane and decreased cellular infiltration) were observed in TNF-alpha group.


CONCLUSIONS
Efficient local delivery of lentivirus-mediated siRNA targeting TNF-alpha into modified murine air pouch can inhibit debris-induced inflammation effectively, with no systemic adverse effects.
Peng
Xiao-chun
XC
Department of Orthopaedics, the Sixth Affiliated People's Hospital of Shanghai Jiaotong University, Shanghai 200233, China.
Zhang
Xian-long
XL
Tao
Kun
K
Cheng
Tao
T
Zhu
Jun-feng
JF
Zeng
Bing-fang
BF
D000818:Animals; D004195:Disease Models, Animal; D015316:Genetic Therapy; D005822:Genetic Vectors / Q000235:genetics; D007249:Inflammation / Q000628:therapy*; D016086:Lentivirus / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D034741:RNA, Small Interfering / Q000235:genetics*; D011897:Random Allocation; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*
D034741:RNA, Small Interfering; D014409:Tumor Necrosis Factor-alpha