艾滋病毒「對大腦發起雙重攻擊」

患有艾滋病痴獃后大腦不能修復
The brain cannot regenerate in HIV-associated dementia

HIV 'launches two-pronged attack on brain'

　　[BEIJING] Scientists have identified a way that HIV causes dementia, which could help in developing drugs to treat the disorder.

　　The study was published this week (16 August) in the journal Cell Stem Cell.

　　HIV infection can cause difficulties in memory and learning in patients with advanced disease, a condition known as HIV-associated dementia.

　　Anti-retroviral drugs are not entirely effective in protecting patients from developing the condition because the drugs cannot successfully reach the brain.

　　"The brain therefore is a protected reservoir of HIV," says Stuart Lipton from the California-based Burnham Institute for Medical Research.

　　Lipton and colleagues found that besides killing neural cells, the HIV virus also inhibits the ability of brain cells to regenerate.

　　Using mice, Lipton and colleagues found that a viral protein called HIV/gp120 prevents 'unprogrammed' brain cells ― stem cells ― called adult neural progenitor cells, from developing into new brain cells, thus preventing the brain from repairing itself.


　　The viral protein does this by activating a brain enzyme ― p38 MAPK ― that blocks brain stem cells from dividing.

　　Lipton said that a drug that blocks this enzyme could have potential for treating and preventing HIV-associated dementia.

　　Lu Hongzhou, deputy director of Shanghai Public Health Centre, says now that the Chinese government offers free anti-retroviral treatment to AIDS patients, they live longer and the problem of HIV-associated dementia has become more apparent.

　　"Previously, many doctors were not aware of the HIV-associated dementia disease, and now, with these kind of studies, doctors can better understand the mechanism of the disease," Lu told SciDev.Net.

　　Liu Zhe, director of the Nerve Signal Imitation Laboratory at the Beijing Institute for Psychological Medicine, adds that the study might be used by doctors to distinguish different kinds of dementia and to understand the degree of neural diseases.

　　"But there is a long way before it could be put into clinical practice," Liu told SciDev.Net.

　　艾滋病毒「對大腦發起雙重攻擊」

　　[北京]科學家發現了艾滋病病毒導致痴呆症的方式，這可能有助於開發治療這種精神系統紊亂疾病的新葯。這項研究發表在了8月16日出版的《細胞·幹細胞》雜誌上。

　　艾滋病感染能夠引發晚期患者的記憶力和學習困難，這種狀況稱為艾滋病痴獃。

　　目前治療艾滋病的抗逆轉錄病毒藥物並不能完全有效的保護病人不發生艾滋病痴獃，因為這類藥物很難進入大腦。美國加州Burnham醫學研究所的Stuart Lipton說：「大腦因此成為了艾滋病毒的受保護的存貯區。」

　　Lipton及其同事發現，除了殺死神經細胞外，艾滋病毒還能抑制大腦細胞再生的能力。Lipton和同事用小鼠發現了一個名為HIV/gp120的艾滋病病毒蛋白阻止了名為成年神經前體細胞（adult neural progenitor cells）的大腦幹細胞分化成新的腦細胞，從而讓大腦無法修復自己。

　　病毒蛋白通過激活大腦的一個酶——p38 MAPK——來阻止大腦幹細胞分化。Lipton說，一種抑制這種酶的藥物有可能治療和預防艾滋病痴獃。

　　上海公共衛生中心的副主任盧洪洲表示，隨著中國政府為艾滋病患者提供免費的抗逆轉錄病毒藥物，他們的存活期更長了，艾滋病痴獃的問題因而也更加明顯。

　　「過去，許多醫生意識不到艾滋病痴呆症，現在，通過這類研究，醫生們能更好地理解這種疾病的機理，」 盧洪洲告訴本網路記者。

　　北京心理醫學研究所神經導叢實驗室主任劉喆補充說，這一研究可以被醫生們用來識別不同種類的痴呆症，並更好地理解神經病變的程度。

　　但是他告訴本網路，「要把這一研究能投入臨床實踐還有很長一段路要走。」

（ZT）