From: unk...@googlegroups.com   
      
   This Alzheimer's Breakthrough Could Be a Game Changer   
   Alice Park @aliceparkny  Oct. 13, 2014    
      
          
   Scientists recreated what goes on in the brains of Alzheimer's patients in a   
   3D culture dish that could speed development of new drugs for the disease   
      
   Researchers have overcome a major barrier in the study of Alzheimer's that   
   could pave the way for breakthroughs in our understanding of the disease, a   
   new report shows--and that new understanding could, in turn, pave the way for   
   drugs that treat or    
   interrupt the progression of the neurodegenerative condition.   
      
      
      
   For decades, animals have been the stand-ins for studying human disease, and   
   for good reason. Their shorter lifespans mean they can model human conditions   
   in weeks or months, and their cells can be useful for testing promising new   
   drug treatments.   
      
      
      
   But they haven't been so helpful in studying Alzheimer's disease. Two factors   
   contribute to the neurodegenerative condition -- the buildup of sticky plaques   
   of the protein amyloid, and the toxic web of another protein, tau, which   
   strangles healthy nerve    
   cells and leaves behind a tangled mess of dead and dying neurons. Despite   
   attempts by scientists to engineer mice who exhibit both factors, they haven't   
   been able to generate the tau tangles that contribute to the disease.   
      
   Now, Dr. Rudolph Tanzi and Dr. Doo Kim at the Mass General Institute for   
   Neurodegenerative Diseases at Massachusetts General Hospital, have devised a   
   work-around that doesn't involve animals. They have developed a way to watch   
   the disease progress in a    
   lab dish.   
      
   "In this new system that we call 'Alzheimer's-in-a-dish,' we've been able to   
   show for the first time that amyloid deposition is sufficient to lead to   
   tangles and subsequent cell death," said Tanzi in a statement.   
      
   MORE: Blood Test for Alzheimer's   
      
   While autopsies showed evidence of both amyloid and tau in the brain,   
   Alzheimer's experts have been debating for years which came first -- do   
   amyloid plaques trigger the formation of tau tangles, or does the presence of   
   tau cause amyloid to get stickier    
   and bunch together in the brain? Tanzi and his colleagues showed definitively   
   for the first time that amyloid is the first step in the Alzheimer's process,   
   followed by tau tangles. When he blocked the formation of amyloid in the   
   culture with a known    
   amyloid inhibitor, tau tangles never formed.   
      
   The disease-in-a-dish model is an emerging way of understanding conditions   
   that either can't be recapitulated accurately in animals, or diseases that   
   make it difficult to study and test in human patients. In recent years, for   
   example, scientists have    
   successfully recreated the process behind amyotrophic lateral sclerosis (ALS),   
   or Lou Gehrig's disease, using stem cells from patients and allowing them to   
   develop into the motor neurons that are affected by the disease. The technique   
   led to a    
   breakthrough in understanding that a certain population of nerve cells known   
   as glial cells poison the motor neurons and impede their normal function. Now   
   experts are focusing on finding ways to control the glial cell activity as   
   possible treatment for    
   ALS.   
      
   MORE: How Moodiness and Jealousy May Lead to Alzheimer's   
      
   Tanzi and his team are hoping that something similar will come from their   
   model of Alzheimer's.   
      
   While the genes responsible for the inherited form of Alzheimer's differ   
   slightly from those involved in the more common form that affects people as   
   they age, the end result -- the build up of amyloid plaques and tau tangles --   
   are the same. So now that    
   they can see both the clumps of amyloid and the tau tangles, form, they can   
   start to tease apart the processes that link the two processes together.   
      
   That will open the way toward finding drugs or other ways of interrupting the   
   process more quickly than they could working with animals. It took six to   
   eight weeks for the cells in the dish to form plaques and then tangles,   
   compared to a year or so in    
   mice. "We can now screen hundreds of thousands of drugs in this system that   
   recapitulates both plaques and tangles...in a matter of months," Tanzi said.   
   "This was not possible in mouse models." The system also makes it possible to   
   test these drug    
   compounds at one-tenth the cost of evaluating them in mice, he said. And that   
   means that finding a way to prevent Alzheimer's may come both faster and   
   cheaper than scientists had expected.   
      
      
   http://time.com/3502215/this-alzheimers-breakthrough-could-be-a-game-changer/   
      
   --- SoupGate-Win32 v1.05   
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