Monday, October 27, 2014
Monday, October 20, 2014
A group of New England scientists say they have confirmed what Alzheimer’s disease researchers have long theorized but had been unable to prove: The brain-killing illness is caused by the deposit of a protein in the brain, known as beta amyloid, that triggers a devastating series of dementia-causing events.
Scientists at Massachusetts General Hospital also identified an enzyme that plays a key role in the progression of the disease – thereby offering a target for pharmaceutical-makers to develop a drug that would halt the neurodegenerative disease.
Their results were published online Sunday in the journal Nature.
The team arrived at their conclusion using an innovative laboratory culture they dubbed “Alzheimer’s-in-a-dish.” Instead of cultivating single-layer cultures of test cells in two-dimensional liquid-based systems, the team grew multiple-layered cultures of neural stem cells in gelatin-like, three-dimensional models that more closely resemble the brain.
The scientists used the 3D cultures to answer a simple question: Does beta amyloid actually cause Alzheimer’s disease?
For some time since Bavarian doctor Alois Alzheimer first identified the condition that bears his name, scientists have known that the distinguishing features of Alzheimer’s disease were the presence of two protein variants: amyloid beta, which forms insoluble plaques, and tau, which creates neurofibrillary tangles.
Scientists have also known that both must be present for the symptoms of Alzheimer’s to appear – cognitive impairment, loss of memory and inability to perform certain motor activities.