脑部血管破坏可能与阿尔兹海默症有关

开始神话

-最近研究发现，阿尔兹海默症与血管型痴呆症之间可能存在着某些联系。根据最近发表在Nature Communications上的一项研究显示，阿尔兹海默症的产生可能与脑部血管的崩坏有所联系。这一发现有助于阐明为什么淀粉样蛋白会导致神经元死亡。

来自南加州大学与美国国家健康中心（NIH）下属的神经紊乱与中风研究中心（NINDS）的研究人员开发了两种新的转基因小鼠用于研究该课题。其中一种脑部含有与遗传性阿尔兹海默症相关的淀粉样蛋白，另外一种是PDGFR-beta突变型小鼠，PDGFR-beta与血脑屏障有关。利用这两种小鼠，研究人员发现血管上的周皮细胞可能参与运输了淀粉样蛋白跨越血脑屏障，进而导致脑部神经元损伤并最终促成阿尔兹海默症的发生。

详细英文报道：

Alzheimer's disease and vascular dementia, the two most common dementias, may be more alike than scientists previously thought.

While Alzheimer's is characterized as an age-related disease that erodes a person's memory, vascular dementias are brain disorders that are marked by a range of blood vessel problems. Now, researchers believe blood vessel breakdown may also be linked to Alzheimer's disease.

The brains of Alzheimer's patients are riddled with extensive neuron loss, beta-amyloid protein accumulation next to brain cells, and neurofibrillary tangles inside neurons. A new study, published in Nature Communications and funded by NIH, suggests that cells called pericytes, which are found on the outside of blood vessels and line the blood-brain barrier, may help point to whether increased beta-amyloid causes tangles and neuron loss.

Researchers at the University of Southern California in Los Angeles and the National Institute of Neurological Disorders and Stroke (NINDS), a branch of NIH, genetically engineered two kinds of mice--ones that have a form of amyloid precursor protein linked to hereditary Alzheimer's and those with reduced levels of platelet-derived growth factor beta receptor (PDGFR-beta), a protein that controls pericyte growth and survival. Pericytes along the blood-brain barrier work with other cells to transport nutrients and waste molecules between the blood and the brain tissue fluid. From previous studies, scientists know that PDGFR-beta mice have lower levels of pericytes, decreased brain blood flow, and damage to the blood-brain barrier.

Researchers found that both the APP and PDGFR-beta mutant mice had problems with learning and memory. Crossbreeding the mice slightly enhanced these problems and increased beta-amyloid levels near brain cells and along brain blood vessels. The brains of the crossbred mice also showed greater neuronal cell death and extensive neurofibrillary tangles in the hippocampus and cerebral cortex, regions that are typically affected during Alzheimer's.

Crossbreeding the mice slowed the rate at which beta-amyloid was cleared away from nerve cells in the brain, suggesting that pericytes may transport beta-amyloid across the blood-brain barrier into the blood

The findings suggest that pericytes and other blood-brain barrier cells may provide new therapeutic targets to treat Alzheimer's.

开始神话

2013年12月20日讯