Department of Biological Sciences, College of Natural Sciences, Kongju National University, Korea.
J Pharmacol Sci. 2014;125(1):83-90. doi: 10.1254/jphs.13232fp. Epub 2014 Apr 19.
Increasing evidence supports the role of microRNAs (miRNA) in the regulation of inflammation in various human disorders. Several recent studies have demonstrated that microRNA-25 (miR-25) has multiple functions, and it affects the expression of inflammatory mediators. Withaferin A (WFA), a natural compound derived from the medicinal plant Withania somnifera, has shown the potential to be an effective drug for arthritis treatment in several preclinical and clinical studies. We investigated the role of miR-25 in the WFA-mediated up-regulation of cyclooxygenase-2 (COX-2) expression in rabbit articular chondrocytes. WFA induced COX-2 expression in a dose-dependent manner as analyzed by western blot analysis and immunofluorescence staining in rabbit articular chondrocytes. WFA up-regulated miR-25 expression as determined by real-time PCR. Overexpression of miR-25 in the presence of WFA increased the expression of COX-2 compared to that observed with just WFA treatment alone, as indicated by western blot analysis and Real-time PCR. Moreover, silencing of miR-25 by anti-miR25 inhibited COX-2 expression in a dose-dependent manner. Since miR-25 up-regulation by WFA treatment induced the expression of COX-2 in rabbit articular chondrocytes, these findings collectively suggest that miR-25 mediates the WFA-induced inflammatory responses in chondrocytes.
越来越多的证据支持 microRNAs（miRNA）在各种人类疾病中的炎症调节作用。最近的几项研究表明，microRNA-25（miR-25）具有多种功能，它影响炎症介质的表达。Withaferin A（WFA），一种从药用植物 Withania somnifera 中提取的天然化合物，在几项临床前和临床试验中显示出作为关节炎治疗有效药物的潜力。我们研究了 miR-25 在 WFA 介导的兔关节软骨细胞中环氧化酶-2（COX-2）表达上调中的作用。Western blot 分析和免疫荧光染色显示，WFA 以剂量依赖性方式诱导 COX-2 的表达。实时 PCR 测定表明 WFA 上调 miR-25 的表达。在存在 WFA 的情况下过表达 miR-25 会增加 COX-2 的表达，与仅用 WFA 处理相比，Western blot 分析和实时 PCR 均表明这一点。此外，用 anti-miR25 沉默 miR-25 会以剂量依赖性方式抑制 COX-2 的表达。由于 WFA 处理引起的 miR-25 上调诱导兔关节软骨细胞中 COX-2 的表达，这些发现共同表明 miR-25 介导了 WFA 诱导的软骨细胞中的炎症反应。
