科学家日前破解了日本脑炎病毒如何让许多被感染的儿童终身遭受大脑和神经系统问题的秘密。
日本脑炎（乙脑）病毒是由蚊子传播的，而且与西尼罗河病毒亲缘密切。大约70%感染这种病毒的儿童会死亡、终身瘫痪、痉挛或者产生智力缺陷。
如今，来自印度Manesar的国立大脑研究中心（NBRC）的科学家发现了乙脑病毒如何永久性地损伤大脑。NBRC的科学家Anirban Basu说这种病毒不仅杀死脑细胞，而且还杀死产生新的脑细胞和神经细胞的干细胞。Basu说：“这是一个双重打击。不仅仅是神经元（神经细胞）死亡，产生神经元的干细胞也死亡了。”他还说：“由于神经干细胞群的不足，儿童受到了永久性的损害。”
Basu及其同事Sulagna Das的发现发表在了即将出版的《神经化学杂志》（Journal of Neurochemistry）上，他们发现乙脑病毒会干扰特定阶段的干细胞分化，阻止了它们的增殖。
该发现可能帮助科学家设计出一个基于改进挽救神经细胞和干细胞并帮助它们增殖的方法的治疗策略。
在2008年2月出版的《神经化学杂志》上，Basu及其同事报告说，一种常见抗生素四环素的衍生物米诺环素可以保护感染乙脑的小鼠免受脑和神经损伤。这组作者写道：“这些数据提示可以考虑米诺环素作为人类乙脑临床实验的候选药物。”
Basu说乙脑是穷国的被忽视疾病，很少有科学家研究这种疾病。美国的非营利组织适宜卫生技术组织（PATH）说乙脑每年导致亚洲超过5万人感染，其中大多数是易感儿童。估计约有30亿人生活在乙脑流行的地区。
对于乙脑感染没有特定的疗法，流行区的公共卫生当局依靠的是控制蚊子的措施和为儿童接种疫苗。在现有的两种乙脑疫苗中，一种由灭活小鼠脑组织制成的疫苗价格昂贵，而另一种中国的减毒活疫苗在中国和尼泊尔的临床实验中展现了前景。（生物谷Bioon.com）
生物谷推荐原始出处：
Journal of Neurochemistry，doi：10.1111/j.1471-4159.2008.05511.x，Sulagna Das，Anirban Basu
Japanese encephalitis virus infects neural progenitor cells and decreases their proliferation
Sulagna Das and Anirban Basu
National Brain Research Centre, Manesar, Haryana, India
Address correspondence and reprint requests to Anirban Basu, National Brain Research Centre, Manesar, Haryana-122050, India. E-mail: anirban@nbrc.res.in
Copyright Journal compilation © 2008 International Society for Neurochemistry
ABSTRACT
Japanese encephalitis virus (JEV), a common cause of encephalitis in humans, especially in children, leads to substantial neuronal injury. The survivors of JEV infection have severe cognitive impairment, motor and behavioral disorders. We hypothesize that depletion of neural progenitor cells (NPCs) by the virus culminates in neurological sequelae in survivors of Japanese encephalitis (JE). We utilized both in vivo model of JEV infection and in vitro neurosphere cultures to study progressive JEV infection. Cellular infection and cell death was determined by flow cytometry. BrdU administration in animals and in neurospheres was used to determine the proliferative ability of NPCs. JEV leads to massive loss of actively proliferating NPC population from the subventricular zone (SVZ). The ability of JEV infected subventricular zone cells to form neurospheres is severely compromised. This can be attributed to JEV infection in NPCs, which however do not result in robust death of the resilient NPC cells. Instead, JEV suppresses the cycling ability of these cells, preventing their proliferation. JEV primarily targets at a critical postnatal age and severely diminishes the NPC pool in SVZ, thus impairing the process of recovery after the insult. This arrested growth and proliferation of NPCs might have an effect on the neurological consequences in JE survivors.
