Li Ying, Xiong Weijian, Yang Jing, Zhong Jin, Zhang Ling, Zheng Jing, Liu Hong, Zhang Qi, Ouyang Xiaoqin, Lei Lei, Yu Xiao
Department of Nephrology, Chongqing Hospital of Traditional Chinese Medicine, Chongqing, China.
Iran J Kidney Dis. 2015 May;9(3):202-8.
Emodin, an anthraquinone derivative from the Chinese herb Radix et Rhizoma Rhe, has been reported to possess anti-inflammatory property in vivo and in vitro. However, the effect of emodin on inflammation in lipopolysaccharide (LPS)-induced acute kidney injury as an immunomodulator has yet to be determined. This study aimed to investigate whether emodin had protective effects against LPS-induced acute kidney injury by inhibiting toll-like receptor 2 (TLR2) signal pathway in normal rat kidney epithelial cells (NRK-52E).
The NRK-52E cells were incubated with LPS with and without the indicated concentrations of emodin for 24 hours. The TLR2 and NF-κB protein level was detected by Western blot method. Tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 protein levels were measured using an enzyme-linked immunosorbent assay. The mRNA expression of TLR2, NF-κB, TNF-α, IL-1β, and IL-6 was detected using a real-time polymersase chain reaction.
A concentration of 102 ng/mL of LPS significantly upregulated mRNA and protein levels of TLR2 and NF-κB and increased TNF-α, IL-1β, and IL-6 mRNA and protein levels. At doses of 20 µM and 40 µM, emodin was able to inhibit LPS-induced TLR2, NF-κB, TNF-α, IL-1β and IL-6 mRNA and protein expressions in cultured NRK-52E cells.
These results demonstrate that an elevated expression of inflammatory cytokines and TLR2 in cells stimulated by LPS were simultaneously inhibited by emodin. Therefore, emodin attenuates the inflammation by inhibiting TLR2-mediated NF-κB signal pathway, which may contribute to the immune inflammation regulation of emodin in LPS-induced acute kidney injury.
大黄素是一种从中药大黄根茎中提取的蒽醌衍生物，据报道在体内和体外均具有抗炎特性。然而，大黄素作为一种免疫调节剂对脂多糖（LPS）诱导的急性肾损伤炎症的影响尚未确定。本研究旨在探讨大黄素是否通过抑制正常大鼠肾上皮细胞（NRK-52E）中的Toll样受体2（TLR2）信号通路对LPS诱导的急性肾损伤具有保护作用。
将NRK-52E细胞与有或无指定浓度大黄素的LPS孵育24小时。通过蛋白质印迹法检测TLR2和NF-κB蛋白水平。使用酶联免疫吸附测定法测量肿瘤坏死因子（TNF）-α、白细胞介素（IL）-1β和IL-6蛋白水平。使用实时聚合酶链反应检测TLR2、NF-κB、TNF-α、IL-1β和IL-6的mRNA表达。
浓度为102 ng/mL的LPS显著上调TLR2和NF-κB的mRNA和蛋白水平，并增加TNF-α、IL-1β和IL-6的mRNA和蛋白水平。在20 μM和40 μM剂量下，大黄素能够抑制培养的NRK-52E细胞中LPS诱导的TLR2、NF-κB、TNF-α、IL-1β和IL-6的mRNA和蛋白表达。
这些结果表明，大黄素同时抑制了LPS刺激的细胞中炎性细胞因子和TLR2的表达升高。因此，大黄素通过抑制TLR2介导的NF-κB信号通路减轻炎症，这可能有助于大黄素对LPS诱导的急性肾损伤的免疫炎症调节。
