科學家日前破解了日本腦炎病毒如何讓許多被感染的兒童終身遭受大腦和神經(jīng)系統(tǒng)問題的秘密,。
日本腦炎(乙腦)病毒是由蚊子傳播的,而且與西尼羅河病毒親緣密切,。大約70%感染這種病毒的兒童會死亡,、終身癱瘓、痙攣或者產(chǎn)生智力缺陷,。
如今,,來自印度Manesar的國立大腦研究中心(NBRC)的科學家發(fā)現(xiàn)了乙腦病毒如何永久性地損傷大腦。NBRC的科學家Anirban Basu說這種病毒不僅殺死腦細胞,,而且還殺死產(chǎn)生新的腦細胞和神經(jīng)細胞的干細胞,。Basu說:“這是一個雙重打擊。不僅僅是神經(jīng)元(神經(jīng)細胞)死亡,,產(chǎn)生神經(jīng)元的干細胞也死亡了,。”他還說:“由于神經(jīng)干細胞群的不足,,兒童受到了永久性的損害,。”
Basu及其同事Sulagna Das的發(fā)現(xiàn)發(fā)表在了即將出版的《神經(jīng)化學雜志》(Journal of Neurochemistry)上,他們發(fā)現(xiàn)乙腦病毒會干擾特定階段的干細胞分化,,阻止了它們的增殖,。
該發(fā)現(xiàn)可能幫助科學家設計出一個基于改進挽救神經(jīng)細胞和干細胞并幫助它們增殖的方法的治療策略。
在2008年2月出版的《神經(jīng)化學雜志》上,,Basu及其同事報告說,,一種常見抗生素四環(huán)素的衍生物米諾環(huán)素可以保護感染乙腦的小鼠免受腦和神經(jīng)損傷。這組作者寫道:“這些數(shù)據(jù)提示可以考慮米諾環(huán)素作為人類乙腦臨床實驗的候選藥物,。”
Basu說乙腦是窮國的被忽視疾病,,很少有科學家研究這種疾病。美國的非營利組織適宜衛(wèi)生技術組織(PATH)說乙腦每年導致亞洲超過5萬人感染,,其中大多數(shù)是易感兒童,。估計約有30億人生活在乙腦流行的地區(qū)。
對于乙腦感染沒有特定的療法,,流行區(qū)的公共衛(wèi)生當局依靠的是控制蚊子的措施和為兒童接種疫苗,。在現(xiàn)有的兩種乙腦疫苗中,,一種由滅活小鼠腦組織制成的疫苗價格昂貴,而另一種中國的減毒活疫苗在中國和尼泊爾的臨床實驗中展現(xiàn)了前景,。(生物谷Bioon.com)
生物谷推薦原始出處:
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: [email protected]
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.