波士顿， 3月29日（合众国际社） - 美国和加拿大的研究人员说，阿尔茨海默氏病的记忆丧失，可能是与锌失衡引起的微管损坏有关。

哈佛大学的资深作家鲁道夫·坦齐说，阿尔茨海默氏病的大脑有两种类型的病灶——老年斑和神经元纤维缠结。已知的阿尔茨海默氏症致病基因与斑块有关，而且与σ-蛋白微管缠结更密切的关联。

坦齐说，锌能稳定多种蛋白复合物，包括微管、微管蛋白聚合物，它们在调节神经突触和神经元记忆编码方面起重要作用。

坦齐和在美国波士顿大学，阿尔伯塔大学，亚利桑那大学和乔普拉基金会的同事确定了促进微管蛋白相互作用的锌-微管蛋白具体的结合位点。

坦齐说，β-淀粉样蛋白斑对阿尔茨海默氏病本身没有破坏性，而是降低了神经细胞中锌的水平，这就破坏了微管和σ-蛋白微管，造成缠结和记忆丧失。保护微管和σ-蛋白微管是治疗阿尔茨海默氏病的最佳治疗方法。

这一研究发表在PloS One上，可能提供不同的治疗方法。

http://www.upi.com/Health_News/2012/03/29/Alzheimers-memory-loss-linked-to-zinc/UPI-32741333058775/#ixzz1qYxUQ6On

Alzheimer's memory loss linked to zinc

Published: March. 29, 2012 at 6:06 PM

BOSTON, March 29 (UPI) -- U.S. and Canadian researchers said Alzheimer's disease's memory loss might be due to disruption of micro tubules caused by zinc imbalance.

Senior author Rudolph Tanzi of Harvard said Alzheimer's disease brains have two types of lesions -- beta-armload plaques outside neurons, and neurofibrillary tangles within them. The known Alzheimer's disease genes implicate plaques but Alzheimer's disease symptoms correlate more closely with tangles, comprised of "tau" protein, normally adhered to microtubules.

Tanzi said zinc stabilizes many protein complexes, including microtubules, polymers of tubulin, which regulate synapses and play recently revealed key roles in memory encoding in neurons.

Tanzi and colleagues at Boston University, The University of Alberta, The University of Arizona and The Chopra Foundation identified specific zinc-tubulin binding sites promoting side-to-side tubulin interactions.

"It looks like beta-amyloid plaques -- linked to Alzheimer's disease's -- themselves aren't destructive directly but lead to lower zinc levels within neurons. This in turn disrupts microtubules and tau, causing tangles and memory loss," Tanzi said in a statement. "Protecting microtubules and their association with tau may be the best treatment approach in Alzheimer's disease."

The findings published in the journal PLoS One might lead to different therapies.