Prions Involved in Some Alzheimer's

    It’s like the molecular version of the Joker and the Riddler teaming up against Batman. Scientists at Yale University have discovered that amyloid beta, a protein involved in Alzheimer’s disease, can damage brain cells by binding to prion proteins, which are themselves infamous because, in their abnormal form, they cause things like mad cow disease.

    Amyloid beta is best known as the protein that forms the giant plaques that riddle the brains of people with Alzheimer’s. Those plaques contain billions of copies of amyloid beta all stuck together in one gloppy mess. But the protein also exists in a more soluble form, either in single units or in small groups of 50 or 100. These smaller clusters don’t cause the same large-scale mayhem as plaques, but they do damage neurons, impairing their ability to learn. And the Yale researchers wanted to find out how.

    They discovered that amyloid beta binds to the prion proteins normally found on neurons. What’s more, the prions ramp up amyloid beta’s neurotoxic effects. Taking away the prions and amyloid-beta clusters are harmless, findings published in the journal Nature. So drugs that prevent this amyloid–prion coupling could be a potent weapon against Alzheimer’s.

    朊病毒與有些老年癡呆癥相關

    耶魯大學的科學家們發現ß-淀粉樣蛋白（一種與老年癡呆癥有關的蛋白）能通過結合朊病毒蛋白對大腦造成損害，朊病毒蛋白本身就“臭名昭著”，因為它們的變體能導致諸如瘋牛病之類的病害。看來，ß-淀粉樣蛋白與朊病毒蛋白的“狼狽為奸”就像是《蝙蝠俠》里面的Joker 和Riddler 一樣勾結在一起與蝙蝠俠作對。

    眾所周知ß-淀粉樣蛋白導致老年癡呆癥患者的大腦里面形成巨大的斑塊。這些斑塊含有數十億的ß-淀粉樣蛋白拷貝，它們亂七八糟地堆積在一起形成一個糊狀的大塊。不過這些蛋白質也以更加易溶的形式存在，它們要么以單個單元存在，要么由50個或者100個蛋白質構成一個小群體。雖然這些小一點兒的團簇不會像斑塊那樣造成大規模的混亂，但是它們也的確損害對神經元，影響神經元學習的能力。耶魯大學的研究人員們想發現這到底是如何進行的。

    研究人員發現與ß-淀粉樣蛋白與通常是在神經元上發現的朊病毒蛋白結合在一起。而且，朊病毒蛋白增強了ß-淀粉樣蛋白的神經毒性。發表在《自然》(Nature)雜志上的研究表明，取走ß-淀粉樣蛋白和朊病毒蛋白團簇不會對患者造成傷害。所以能防止ß-淀粉樣蛋白和朊病毒蛋白結合的藥物可能會成為治療老年癡呆癥的強有力武器。

    Vocabulary:

Prion：朊病毒
Alzheimer's：老年癡呆癥（也稱阿爾茲海默病）
Amyloid beta：ß-淀粉樣蛋白
Infamous: 臭名昭著的
Abnormal: 反常的
Giant：巨大的
Plaque: 斑塊
Gloppy: 糊狀的
Mayhem: 混亂
Neuron: 神經元
Impair: 損傷
Ramp up: 增強；提高
Potent: 強大的