Department of Medicine and Rheumatology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
J Pharmacol Exp Ther. 2012 Jan;340(1):109-13. doi: 10.1124/jpet.111.185884. Epub 2011 Oct 12.
RNA interference, mediated by small interfering RNA (siRNA), is effective in silencing genes with a high degree of specificity. To explore the therapeutic potential of systemically administered siRNA for rheumatoid arthritis (RA), we tested the complex of siRNA and the recently developed wrapsome (siRNA/WS) containing siRNA-encapsulated liposome in mice with collagen-induced arthritis (CIA). Mice with CIA received an intravenous injection of Cy5-labeled siRNA/WS. Fluorescence stereoscopic microscopy and flow cytometry were used to assess the siRNA/WS tissue distribution. The efficacy of siRNA-targeting tumor necrosis factor (TNF)-α/WS in CIA was evaluated by arthritis score. TNF-α mRNA levels in the joints were measured by real-time reverse transcriptase-polymerase chain reaction. The intensity of Cy5 fluorescence was higher in arthritic joints than in nonarthritic sites in Cy5-siRNA/WS-treated mice and remained higher up to 48 h after injection, compared with that in naked Cy5-siRNA-treated mice. Cy5 fluorescence intensity was higher in synovial cells than in splenocytes, bone marrow cells, and peripheral blood leukocytes. The majority of Cy5-positive synovial cells were CD11b⁺ with only a few CD3⁺ cells. Treatment with TNF-α siRNA/WS resulted in significant decreases in severity of arthritis and TNF-α mRNA level in the joints compared with control siRNA/WS. In conclusion, the use of our WS allowed efficient and targeted delivery of siRNAs to arthritic joints. The siRNA/WS was mainly incorporated into CD11b⁺ cells, including macrophages and neutrophils, in the inflamed synovium, suggesting its potential therapeutic effects in RA by silencing the expression of inflammatory molecules produced by these cells.
RNA 干扰，由小干扰 RNA（siRNA）介导，在基因沉默方面具有高度特异性。为了探索系统性给予 siRNA 治疗类风湿关节炎（RA）的潜力，我们在胶原诱导关节炎（CIA）小鼠中测试了 siRNA 与最近开发的包裹体（siRNA/WS）的复合物，该包裹体包含包裹有 siRNA 的脂质体。CIA 小鼠接受静脉注射 Cy5 标记的 siRNA/WS。荧光立体显微镜和流式细胞术用于评估 siRNA/WS 的组织分布。通过关节炎评分评估靶向肿瘤坏死因子（TNF）-α/WS 的 siRNA 在 CIA 中的疗效。通过实时逆转录-聚合酶链反应测量关节中 TNF-α mRNA 水平。与裸 Cy5-siRNA 处理的小鼠相比，在接受 Cy5-siRNA/WS 治疗的小鼠中，关节炎部位的 Cy5 荧光强度高于非关节炎部位，并且在注射后 48 小时内仍保持较高水平。Cy5 荧光强度在滑膜细胞中高于脾细胞、骨髓细胞和外周血白细胞。大多数 Cy5 阳性滑膜细胞是 CD11b⁺，只有少数 CD3⁺细胞。与对照 siRNA/WS 相比，TNF-α siRNA/WS 的治疗导致关节炎严重程度和关节中 TNF-α mRNA 水平显著降低。总之，我们的 WS 的使用允许 siRNA 高效且靶向递送至关节炎关节。siRNA/WS 主要被整合到炎症滑膜中的 CD11b⁺细胞中，包括巨噬细胞和中性粒细胞，这表明其通过沉默这些细胞产生的炎症分子的表达，在 RA 中具有潜在的治疗作用。
