Department of Orthopaedic Surgery, Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University, 107 Yanjiangxi Road, 510120, Guangzhou, China.
Inflammation. 2013 Oct;36(5):1041-54. doi: 10.1007/s10753-013-9636-9.
Aseptic joint loosening is a key factor that reduces the life span of arthroplasty. There are currently few effective treatments for joint loosening except surgical revision. We explored the inhibitory effects of p110β-targeted small interfering RNA (siRNA) and lentivirus on particle-induced inflammatory cytokine expression in the murine macrophage cell line, RAW264.7. siRNA- and lentivirus-targeting p110β were transfected and infected prior to particle stimulation, respectively. Ceramic and titanium particles of different sizes were prepared to stimulate macrophages. Fluorescence microscopy showed that the efficiency of siRNA transfection and lentivirus infection were 74.2 ± 4.2 and 92.3 ± 2.6 %, respectively. TNF-alpha mRNA in the particle stimulation plus RNA interference (RNAi) groups were significantly lower compared with the particle stimulation-only groups (P < 0.05). Similarly, protein levels of TNF-alpha in RNAi-treated groups were significantly decreased after transfection or infection (P < 0.05). It showed that Phosphor-AKT (Ser473) activation was significantly reduced by RNAi through western blot. As assessed by CT, micro-CT and histological analysis, particle implantation induced a significant osteolysis in mice calvaria, which was limited by p110β lentivirus addition. These results suggested that p110β subtype of PI3K, followed by activation of Ser473, may possibly participate in the regulation of macrophages activity by wear particles, ultimately resulting in the TNF-α secretion and osteolysis.
无菌性关节松动是降低关节置换寿命的一个关键因素。除了手术翻修外,目前对于关节松动还没有有效的治疗方法。我们探讨了针对 p110β 的小干扰 RNA(siRNA)和慢病毒对小鼠巨噬细胞系 RAW264.7 中颗粒诱导的炎症细胞因子表达的抑制作用。分别在颗粒刺激前转染和感染靶向 p110β 的 siRNA 和慢病毒。制备不同大小的陶瓷和钛颗粒刺激巨噬细胞。荧光显微镜显示,siRNA 转染和慢病毒感染的效率分别为 74.2±4.2%和 92.3±2.6%。与仅颗粒刺激组相比,颗粒刺激加 RNA 干扰(RNAi)组的 TNF-αmRNA 明显降低(P<0.05)。同样,RNAi 处理组的 TNF-α蛋白水平在转染或感染后明显降低(P<0.05)。Western blot 显示,RNAi 通过抑制 Phosphor-AKT(Ser473)的激活来降低 p110β 的表达。通过 CT、micro-CT 和组织学分析评估,颗粒植入可引起小鼠颅骨明显的骨溶解,p110β 慢病毒的添加可限制其发生。这些结果表明,PI3K 的 p110β 亚型可能通过激活 Ser473 参与磨损颗粒对巨噬细胞活性的调节,最终导致 TNF-α的分泌和骨溶解。