Department of Ophthalmology, Qilu Hospital, Shandong University, Jinan, China.
Parasite Immunol. 2011 Jan;33(1):25-33. doi: 10.1111/j.1365-3024.2010.01247.x.
The pathogenesis of Acanthamoeba keratitis (AK) is complicated. In our previous studies, TLR4 was found involved in the process of infection by Acanthamoeba in human corneal cells. The purpose of this study was to investigate the role of Toll-like receptor 4 (TLR4) signalling pathway in Wistar rats challenged with Acanthamoeba. The rat model of AK was established. Corneas were collected and analysed by real-time PCR to assess the mRNA levels of TLR 2, 4, myeloid differentiation protein (MyD)88, nuclear factor (NF)-κB, extracellular signal-regulated kinase (ERK), interleukin (IL)-8, tumour necrosis factor (TNF)-α and interferon (IFN) -β. Immunocytochemistry and Western blot were conducted to examine the proteins of TLR2, TLR4, p-Erk1/2 and p-IκB. Specific inhibitors PDTC and U0126 were used to pretreat the animals to determine the exact receptor and signalling pathway involved in pathogenesis. Expressions of TLR4, MyD88, all three cytokines, NF-κB, p-IκB and p-Erk1/2 were increased in Acanthamoeba-treated rat corneas. PDTC inhibited the production of IL-8 and TNF-α, while U0126 inhibited the synthesis of IFN-β. TLR4 was involved in sensing the challenge of Acanthamoeba and inducing production of cytokines through TLR4-NF-κB and TLR4-Erk1/2 pathways in corneas of Wistar rats.
棘阿米巴角膜炎（AK）的发病机制较为复杂。在我们之前的研究中，发现 TLR4 参与了棘阿米巴感染人角膜细胞的过程。本研究旨在探讨 Toll 样受体 4（TLR4）信号通路在感染棘阿米巴的 Wistar 大鼠中的作用。建立 AK 大鼠模型。实时 PCR 检测角膜 TLR2、4、髓样分化蛋白（MyD）88、核因子（NF）-κB、细胞外信号调节激酶（ERK）、白细胞介素（IL）-8、肿瘤坏死因子（TNF）-α和干扰素（IFN）-β的 mRNA 水平。免疫细胞化学和 Western blot 检测 TLR2、TLR4、p-Erk1/2 和 p-IκB 蛋白。用特异性抑制剂 PDTC 和 U0126 预处理动物，以确定参与发病机制的确切受体和信号通路。棘阿米巴处理后的大鼠角膜 TLR4、MyD88、三种细胞因子、NF-κB、p-IκB 和 p-Erk1/2 的表达均增加。PDTC 抑制了 IL-8 和 TNF-α的产生，而 U0126 抑制了 IFN-β的合成。TLR4 通过 TLR4-NF-κB 和 TLR4-Erk1/2 通路参与感知棘阿米巴的挑战，并在 Wistar 大鼠角膜中诱导细胞因子的产生。
