Gamma Interferon Alters Junctional Integrity via Rho Kinase, Resulting in Blood-Brain Barrier Leakage in Experimental Viral Encephalitis
Gamma Interferon Alters Junctional Integrity via Rho Kinase, Resulting in Blood-Brain Barrier Leakage in Experimental Viral Encephalitis
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DOI：
10.1128/mbio.01675-19
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发表时间：
2019-07-01
期刊：
影响因子：
6.4
通讯作者：
Siegenthaler, Julie A.
中科院分区：
文献类型：
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作者：
Bonney, Stephanie;Seitz, Scott;Siegenthaler, Julie A.
血脑屏障（BBB）的破坏是许多中枢神经系统（CNS）疾病的标志。CNS疾病如病毒性脑炎中BBB完整性的丧失导致营养/氧递送的丧失、免疫细胞的快速浸润和脑肿胀，这可加剧神经元损伤。尽管如此，在病毒性脑炎中BBB破坏的细胞和分子机制还不完全清楚。我们进行了一个全面的分析的细胞和分子信号转导事件，诱导BBB崩溃的病毒诱导的脑炎，其中新生小鼠感染呼肠孤病毒（血清型3株Abney）的实验模型。我们发现，在呼肠孤病毒感染过程中，血脑屏障渗漏与血管系统的形态学变化，周细胞（血脑屏障支持细胞）的减少和血管连接的紊乱相关。对来自脑内皮细胞的RNA测序的途径分析鉴定了呼肠孤病毒感染后脑血管系统内干扰素（IFN）信号传导的激活。我们在体外和体内的研究表明，II型IFN介导的IFN-γ，一个众所周知的抗病毒信号，是一个主要的贡献者在呼肠孤病毒感染的血脑屏障泄漏。我们发现，IFN-γ降低了屏障特性，在培养的脑内皮细胞通过Rho激酶（ROCK）介导的细胞骨架收缩，导致连接紊乱和细胞-细胞分离。在呼肠孤病毒感染过程中，IFN-γ的体内中和显著改善了BBB的完整性、周细胞覆盖率、减弱的血管ROCK活性和连接紊乱。我们的工作支持一个模型，其中IFN-γ直接作用于脑内皮细胞，通过涉及ROCK诱导的交界disorganization.IMPORTANCE机制诱导BBB击穿在实验性病毒性脑炎小鼠模型中，小鼠感染呼肠孤病毒，我们表明，IFN-γ诱导血脑屏障渗漏。我们表明，IFN-γ促进Rho激酶活性，导致肌动蛋白细胞骨架收缩，导致血管连接紊乱和细胞-细胞分离的脑内皮细胞。这些研究现在提供了一个以前未知的机制，如何发生在病毒性脑炎血脑屏障的破坏，并牵连IFN-γ-Rho激酶活性作为这一现象的主要贡献者。通过确定这种血脑屏障破坏的机制，我们现在为治疗病毒性脑炎患者提供了潜在的治疗靶点，希望限制对中枢神经系统的损害。
Blood-brain barrier (BBB) breakdown is a hallmark of many diseases of the central nervous system (CNS). Loss of BBB integrity in CNS diseases such as viral encephalitis results in the loss of nutrient/oxygen delivery, rapid infiltration of immune cells, and brain swelling that can exacerbate neuronal injury. Despite this, the cellular and molecular mechanisms that underlie BBB breakdown in viral encephalitis are incompletely understood. We undertook a comprehensive analysis of the cellular and molecular signaling events that induce BBB breakdown in an experimental model of virus-induced encephalitis in which neonatal mice are infected with reovirus (serotype 3 strain Abney). We show that BBB leakage during reovirus infection correlates with morphological changes in the vasculature, reductions in pericytes (BBB supporting cells), and disorganization of vascular junctions. Pathway analysis on RNA sequencing from brain endothelial cells identified the activation of interferon (IFN) signaling within the brain vasculature following reovirus infection. Our in vitro and in vivo studies show that type II IFN mediated by IFN-gamma, a well known antiviral signal, is a major contributor to BBB leakage during reovirus infection. We show that IFN-gamma reduces barrier properties in cultured brain endothelial cells through Rho kinase (ROCK)-mediated cytoskeletal contractions, resulting in junctional disorganization and cell-cell separations. In vivo neutralization of IFN-gamma during reovirus infection significantly improved BBB integrity, pericyte coverage, attenuated vascular ROCK activity, and junctional disorganization. Our work supports a model in which IFN-gamma acts directly on the brain endothelium to induce BBB breakdown through a mechanism involving ROCK-induced junctional disorganization.IMPORTANCE In an experimental viral encephalitis mouse model in which mice are infected with reovirus, we show that IFN-gamma induces blood-brain barrier leakage. We show that IFN-gamma promotes Rho kinase activity, resulting in actin cytoskeletal contractions in the brain endothelium that lead to vascular junctional disorganization and cell-cell separations. These studies now provide insight into a previously unknown mechanism for how blood-brain barrier breakdown occurs in viral encephalitis and implicates IFN-gamma-Rho kinase activity as major contributor to this phenomenon. By identifying this mechanism of blood-brain barrier breakdown, we now provide potential therapeutic targets in treating patients with viral causes of encephalitis with the hope of limiting damage to the central nervous system.