Dengue Virus Nonstructural Protein 1 Induces Vascular Leakage through Macrophage Migration Inhibitory Factor and Autophagy.
Dengue Virus Nonstructural Protein 1 Induces Vascular Leakage through Macrophage Migration Inhibitory Factor and Autophagy.
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DOI：
10.1371/journal.pntd.0004828
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发表时间：
2016-07
影响因子：
3.8
通讯作者：
Yeh TM
中科院分区：
文献类型：
--
作者：
Chen HR;Chuang YC;Lin YS;Liu HS;Liu CC;Perng GC;Yeh TM
登革热病毒（DENV）是最常见的蚊媒黄病毒；它可以引起轻度登革热或更严重的登革出血热（DHF）和登革休克综合征（DSS）。DHF/DSS的特征之一是血管渗漏；尽管已证实DENV非结构蛋白1 （NS1）与toll样受体4结合后可诱导血管渗漏，但其下游机制尚不完全清楚。在DENV感染患者的血清中，DENV NS1和炎症细胞因子巨噬细胞迁移抑制因子（MIF）的浓度与疾病严重程度呈正相关，但DENV NS1是否通过MIF分泌诱导血管渗漏尚不清楚。我们证实重组NS1在人内皮细胞系HMEC-1和小鼠中诱导血管渗漏和MIF分泌。此外，这些现象在体外和体内均被抗ns1抗体抑制。DENV NS1还诱导内皮细胞株LC3-I向LC3-II转化，p62降解，提示自噬的形成。为了明确是MIF还是自噬介导了DENV ns1诱导的血管渗漏，使用了各种抑制剂。结果显示，在MIF抑制剂、抗MIF抗体或自噬抑制剂的存在下，DENV ns1诱导的血管渗漏和VE-cadherin紊乱被阻断。Atg5敲低克隆进一步证实，ns1诱导的血管渗漏需要内皮细胞自噬形成。此外，在MIF抑制剂的存在下，DENV ns1诱导的LC3点也减少，表明MIF介导了DENV ns1诱导的自噬。综上所述，这些结果提示了denv诱导血管渗漏的潜在机制，并为DHF/DSS提供了可能的治疗靶点。登革热是一种由蚊子传播的病毒性疾病。登革热的症状通常很轻微；然而，严重登革热是亚洲和拉丁美洲国家儿童住院和死亡的主要原因之一。严重登革热的一个症状是血管渗漏，可导致液体积聚、低血压、循环衰竭，甚至死亡。对于登革热和重症登革热，没有专门的治疗方法，唯一的支持性治疗是将患者的体液维持在正常水平。因此，研究登革病毒（DENV）引起血管渗漏的机制是一个重要而紧迫的问题。在本研究中，我们证明了DENV非结构蛋白1 （NS1）通过分泌巨噬细胞迁移抑制因子（MIF）诱导血管渗漏，形成自噬。抑制MIF或自噬形成可有效逆转ns1诱导的体外和小鼠血管渗漏。这些结果为治疗重症登革热血管渗漏提供了可能的治疗靶点。
Dengue virus (DENV) is the most common mosquito-borne flavivirus; it can either cause mild dengue fever or the more severe dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). One of the characteristic features of DHF/DSS is vascular leakage; although DENV nonstructural protein 1 (NS1) has been proved to induce vascular leakage after binding to Toll-like receptor 4, the down-stream mechanism has not yet been fully understood. In the sera of DENV-infected patients, the concentrations of DENV NS1 and inflammatory cytokine macrophage migration inhibitory factor (MIF) are positively correlated with disease severity, but whether DENV NS1 induces vascular leakage through MIF secretion remains unknown. We demonstrated that recombinant NS1 induced vascular leakage and MIF secretion both in human endothelial cell line HMEC-1 and in mice. Furthermore, these phenomena were inhibited in the presence of anti-NS1 antibodies both in vitro and in vivo. DENV NS1 also induced LC3-I to LC3-II conversion and p62 degradation in endothelial cell line, which indicated the formation of autophagy. To clarify whether MIF or autophagy mediated DENV NS1-induced vascular leakage, various inhibitors were applied. The results showed that DENV NS1-induced vascular leakage and VE-cadherin disarray were blocked in the presence of MIF inhibitors, anti-MIF-antibodies or autophagy inhibitors. An Atg5 knockdown clone further confirmed that autophagy formation of endothelial cells was required in NS1-induced vascular leakage. Furthermore, DENV NS1-induced LC3 puncta were also decreased in the presence of MIF inhibitors, indicating that MIF mediated DENV NS1-induced autophagy. Taken together, the results suggest a potential mechanism of DENV-induced vascular leakage and provide possible therapeutic targets against DHF/DSS. Dengue is a viral disease transmitted by mosquitoes. The symptoms of dengue are often mild; however, severe dengue is one of the leading causes of hospitalization and death among children in Asian and Latin American countries. A symptom of severe dengue is vascular leakage, which can result in fluid accumulation, hypotension, circulatory collapse, and even death. For dengue and severe dengue, there is no specific treatment, and the only supportive treatment is to maintain a patient’s body fluids at normal levels. As a result, investigating the mechanism of how dengue virus (DENV) causes vascular leakage is an important and urgent issue. In this study, we demonstrated that DENV nonstructural protein 1 (NS1) induced vascular leakage through the secretion of macrophage migration inhibitory factor (MIF) and the formation of autophagy. Inhibition of MIF or autophagy formation effectively reversed NS1-induced vascular leakage both in vitro and in mice. These results provide possible therapeutic targets for treating vascular leakage in severe dengue.