S1P 与人类和实验性脑疟疾的保护有关。
S1P is associated with protection in human and experimental cerebral malaria.
机构信息
SA Rotman Laboratories, McLaughlin-Rotman Centre for Global Health, University Health Network and University of Toronto, Canada Faculty of Medicine, University of Toronto, Canada.
出版信息
Mol Med. 2011;17(7-8):717-25. doi: 10.2119/molmed.2010.00214. Epub 2011 May 5.
Cerebral malaria (CM) is associated with excessive inflammatory responses and endothelial activation. Sphingosine 1-phosphate (S1P) is a signaling sphingolipid implicated in regulating vascular integrity, inflammation and T-cell migration. We hypothesized that altered S1P signaling during malaria contributes to endothelial activation and inflammation, and show that plasma S1P levels were decreased in Ugandan children with CM compared with children with uncomplicated malaria. Using the Plasmodium berghei ANKA (PbA) model of experimental CM (ECM), we demonstrate that humanized S1P lyase (hS1PL)(-/-) mice with reduced S1P lyase activity (resulting in increased bio-available S1P) had improved survival compared with wild-type littermates. Prophylactic and therapeutic treatment of infected mice with compounds that modulate the S1P pathway and are in human trials for other conditions (FTY720 or LX2931) significantly improved survival in ECM. FTY720 treatment improved vascular integrity as indicated by reduced levels of soluble intercellular adhesion molecule (sICAM), increased angiopoietin 1 (Ang1) (regulator of endothelial quiescence) levels, and decreased Evans blue dye leakage into brain parenchyma. Furthermore, treatment with FTY720 decreased IFNγ levels in plasma as well as CD4(+) and CD8(+) T-cell infiltration into the brain. Finally, when administered during infection in combination with artesunate, FTY720 treatment resulted in increased survival to ECM. These findings implicate dysregulation of the S1P pathway in the pathogenesis of human and murine CM and suggest a novel therapeutic strategy to improve clinical outcome in severe malaria.
脑型疟疾(CM)与过度炎症反应和内皮细胞激活有关。 1-磷酸鞘氨醇(S1P)是一种信号鞘脂,参与调节血管完整性、炎症和 T 细胞迁移。我们假设疟疾期间 S1P 信号的改变有助于内皮细胞激活和炎症,并表明与无并发症疟疾的儿童相比,乌干达患有 CM 的儿童的血浆 S1P 水平降低。使用伯氏疟原虫 ANKA(PbA)实验性 CM(ECM)模型,我们证明了具有降低的 S1P 裂解酶活性(导致生物可用的 S1P 增加)的人源化 S1P 裂解酶(hS1PL)(-/-)小鼠与野生型同窝仔相比具有更好的存活率。用调节 S1P 途径的化合物(在临床试验中用于其他疾病的 FTY720 或 LX2931)对感染小鼠进行预防性和治疗性治疗,可显著提高 ECM 中的存活率。FTY720 治疗可改善血管完整性,表现为可溶性细胞间黏附分子(sICAM)水平降低、血管生成素 1(Ang1)水平升高(内皮静止的调节剂)和 Evans 蓝染料漏入脑组织减少。此外,FTY720 治疗可降低血浆中的 IFNγ 水平以及 CD4+和 CD8+T 细胞向大脑的浸润。最后,当在感染期间与青蒿琥酯联合给药时,FTY720 治疗可提高 ECM 的存活率。这些发现表明 S1P 途径的失调参与了人类和鼠类 CM 的发病机制,并提出了一种新的治疗策略,以改善严重疟疾的临床结果。