Effect of Emodin on Coxsackievirus B3m-Mediated Encephalitis in Hand, Foot, and Mouth Disease by Inhibiting Toll-Like Receptor 3 Pathway In Vitro and In Vivo. (2nd March 2020)

• Record Type: Journal Article
• Authors: Ding, Yan; Xu, Jie; Cheng, Liang-bin; Huang, Yong-qian; Wang, You-qin; Li, Hui; Li, Yu; Ji, Jing-yu; Zhang, Ji-hong; Zhao, Lei
• Is Part Of: Journal of infectious diseases. Volume 222:Number 3(2020)
• Page Start: 443
• Page End: 455
• Publication Date: 2020-03-02
• Subjects: coxsackievirus B3m -- emodin -- signal pathways -- Toll-like receptor 3; Communicable diseases -- Periodicals; Diseases -- Causes and theories of causation -- Periodicals; Medicine -- Periodicals; Communicable Diseases -- Periodicals; Electronic journals; 616.9
• DOI: 10.1093/infdis/jiaa093
• Languages: English
• ISSNs: 0022-1899

Abstract

Abstract: Background: Encephalitis in hand, foot, and mouth disease (HFMD) is a serious threat to children's health and life. Toll-like receptor 3 (TLR3) is an innate immune-recognition receptor that can recognize virus and initiate innate immune responses. Emodin has the effects of anti-inflammatory and regulating immune function, but the mechanism is not very clear. Methods: Cells and mice were pretreated with coxsackievirus B3m (CVB3) and treated with emodin. The messenger ribonucleic acid (mRNA) and protein levels of TLR3 and downstream molecules were detected by quantitative real-time polymearse chain reaction and western blotting analysis, respectively. TLR3 expression was also downregulated by anti-TLR3 antibody (TLR3Ab) or small interfering RNA (siRNA). Pathological changes were assessed with hematoxylin and eosin staining. Immunohistochemistry was used to examine the expression of TLR3 in brain tissues. The expression of interleukin (IL)-6, nuclear factor (NF)-κB, and interferon (IFN)-β in serum were tested with enzyme-linked immunosorbent assay. Results: Emodin decreased the mRNA and protein levels of TLR3 and downstream molecules in vitro and in vivo. After downregulating TLR3 using anti-TLR3Ab or siRNA, emodin could still decrease the mRNA and protein levels of TLR3 and downstream molecules. Emodin also displayed notable effects on pathology, TLR3 protein in brain tissues, and expression of IL-6, NF-κB, IFN-β, in serum. Conclusions: Emodin exerts a protective effect in CVB3-mediated encephalitis in HFMD by inhibiting the TLR3 pathway. Abstract : This study indicated that TLR3 pathway is a viable therapeutic target for CVB3-mediated encephalitis in HFMD and certified the efficacy of emodin via inhibiting the TLR3 signaling pathway to alleviate CVB3-mediated encephalitis in HFMD in vitro and in vivo.