|Blogs||Articles||Organizations||Biography||Jack's Book||Contact Information||Links|
Navigation: SOS Sisson > Traumatic Injury Blog
Jack Sisson's TBI Blog
A hug is duct tape for the soul.
Saturday, February 09, 2013
Mysterious brain clumps behind dementia identified
From Fox News:
Certain forms of dementia may be caused by a gene mutation that makes proteins in the brain clump together, a new study finds.
The most common cause of frontotemporal dementia and a motor neuron disease called amyotrophic lateral sclerosis (ALS, or Lou Gehrig's disease) is a genetic mutation that creates extra copies of a DNA sequence, but the actual mechanism of the diseases is unknown. A team of researchers has now found that proteins, molecules that normally help cells function, are being produced from the mutated gene and appear to be causing the clumping seen in both those diseases.
The findings, described online Feb. 7 in the journal Science, could explain how these diseases arise and might even be treated.
About 10 percent of FTLD (frontotemporal lobar degeneration) and ALS patients have a mutation in the C9orf72 gene, which contains a short repeated DNA sequence. Healthy people have about 25 repeats of this sequence, but there are hundreds of repeats in these patients. Their brains exhibit telltale clumps of proteins in the hippocampus and cerebellum regions.
While proteins in other forms of dementia are known, patients with this mutation have clumps of other, unknown proteins, said study co-author Dieter Edbauer, a neuroscientist at Ludwig Maximilian University of Munich, in Germany. The mutated gene lacks the label that normally tells cells to start making a protein, and is located in a stretch of the DNA that isn't normally active.
Edbauer and his colleagues hypothesized that if the gene were somehow activated, it would cause three different proteins to be made, and these proteins would aggregate in cells and cause disease.
To test their hypothesis, the researchers took both diseased and healthy brain tissue from deceased patients and filtered it through a fine mesh. Clumps of brain tissue from the patients got stuck in the mesh. By making antibodies (proteins produced by the body to target and fight off foreign invaders) that recognized the three specific proteins, the scientists were able to determine that these were the proteins in the clumps.
"This study helps to resolve a major question about how C9orf72 mutations cause FTD and ALS," said neurologist Adam Boxer of the University of California, San Francisco, who was not involved in the study.
"It suggests that these mutations can lead to creation of a new toxic protein that aggregates and accumulates in cells, similar to other neurodegenerative diseases such as Huntington's and Alzheimer's, which are also associated with toxic protein aggregates," Boxer told LiveScience.
Others agree that the findings, if replicated, will be important. "It would be good to confirm their results using an independent method," said neuropathologist Ian Mackenzie of Vancouver General Hospital and the University of British Columbia, in Canada.
Understanding the diseases
There are several possible explanations for how the proteins are being made. One is that the ribosome, the cellular machinery that reads genetic instructions to make proteins, is misreading the mutated gene. Another possibility is that the repeated sequence is forming a hairpin shape that attracts the ribosome and tells it to make proteins.
It's unclear whether the clumps are causing the diseases or are simply markers. If the protein clumps are in fact responsible, scientists might be able to treat the disease by getting rid of those proteins, Edbauer said.
FTD and ALS are characterized by personality changes, language abnormalities and movement disorders, which often appear before the age of 65. There is currently no cure.
Link to Fox News.
LinksTBI Film Reviews
TBI Book Reviews
Traumatic Brain Injury Law Blog
SoapBlox/Chicago: Protecting Our Troops
Head Injury Survival Journal
Losing the Physical Self
Tower of Hanoi: Instructions for this popular puzzle can be viewed simply by clicking the Instructions button on that page.
May 2005 June 2005 July 2005 August 2005 September 2005 October 2005 November 2005 August 2006 September 2006 October 2006 December 2006 January 2007 February 2007 March 2007 April 2007 May 2007 June 2007 July 2007 August 2007 September 2007 October 2007 November 2007 December 2007 January 2008 February 2008 March 2008 January 2009 March 2009 April 2009 December 2009 April 2010 May 2010 June 2010 July 2010 August 2010 September 2010 October 2010 November 2010 January 2011 February 2011 March 2011 April 2011 May 2011 June 2011 July 2011 August 2011 September 2011 October 2011 November 2011 December 2011 January 2012 February 2012 March 2012 April 2012 May 2012 June 2012 October 2012 November 2012 December 2012 January 2013 February 2013 March 2013 April 2013 May 2013 June 2013 October 2013