Features | Partner Sites | Information | LinkXpress
Sign In
BioConferenceLive
JIB
GLOBETECH PUBLISHING

Alzheimer’s Risk Gene Identified Using Connectome Scan

By BiotechDaily International staff writers
Posted on 20 Mar 2013
Scientists have discovered a new genetic risk factor for Alzheimer’s disease (AD) by screening individual’s DNA and then employing a cutting-edge type of scan to visualize their brains’ connections. The researchers found signs of disease decades before the illness strikes.

The University of California, Los Angeles (UCLA; USA) researchers discovered a common abnormality in the human genetic code that increases the risk of Alzheimer’s. To locate the gene, they used new imaging technology that screens the brain’s connections. Turning off such Alzheimer’s risk genes (in the last 20 years, nine of them have been associated with AD) could block the disorder or delay its onset by many years.

The research is published in the March 4, 2013, online edition of the journal Proceedings of the National Academy of Sciences of the United States of America (PNAS). “We found a change in our genetic code that boosts our risk for Alzheimer’s disease,” said the study’s senior author, Paul Thompson, a UCLA professor of neurology and a member of the UCLA Laboratory of Neuroimaging. “If you have this variant in your DNA, your brain connections are weaker. As you get older, faulty brain connections increase your risk of dementia.”

The researchers, according to Prof. Thompson, screened more than 1,000 people’s DNA to find the common faults in the genetic code that might raise their chance for the disease later in life. The new study was the first of its kind to also give each individual a “connectome scan,” a special type of scan that measures water diffusion in the brain, allowing scientists to map the strength of the brain’s connections.

The new scan, a 4-[F-18]fluoro-N-{2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl}-N-(2-pyridinyl)benzamide, a selective serotonin 1A (5-HT1A) molecular imaging probe, was used in conjunction with positron emission tomography (PET) to reveal the brain’s circuitry and how information is directed around the brain, in order to discover risk factors for disease. The researchers then combined these connectivity scans with the extensive genomic screening to pinpoint what causes faulty wiring in the brain.

Hundreds of computers, calculating for months, sieved through more than 4,000 brain connections and the entire genetic code, comparing connection patterns in people with different genetic variations. In individuals whose genetic code differed in one specific gene called SPON1, weaker connections were found between brain centers controlling cognitive functions and emotion. The errant gene also affects how senile plaques gather in the brain—one of the tell-tale marks of AD.

“Much of your risk for disease is written in your DNA, so the genome is a good place to look for new drug targets,” said Prof. Thompson, who in 2009 founded a research network known as Project ENIGMA to pool brain scans and DNA from 26,000 people worldwide. “If we scan your brain and DNA today, we can discover dangerous genes that will undermine your ability to think and plan and will make you ill in the future. If we find these genes now, there is a better chance of new drugs that can switch them off before you or your family [will] get ill.”

Developing new therapeutics for AD is a hot topic for pharmaceutical research, according to Prof. Thompson. The SPON1 gene can also be manipulated to develop new treatments for the debilitating disease, he noted. When the errant gene was modified in mice, it led to cognitive improvements and fewer plaques building up in the brain. AD patients show an accumulation of these senile plaques, which are made of an adhesive substance called amyloid and are thought to kill brain cells, causing irreversible memory loss and personality changes.

Screening genomes has led to many new drug targets in the treatment of cancer, heart disease, arthritis, and brain disorders such as epilepsy. But the UCLA team’s approach—screening genomes and performing brain scans of the same people—have the potential to provide a faster and more efficient search. “With a brain scan that takes half an hour and a DNA scan from a saliva sample, we can search your genes for factors that help or harm your brain’s connections,” Prof. Thompson said. “This opens up a new landscape of discovery in medical science.”

Related Links:

University of California, Los Angeles




comments powered by Disqus

Channels

Drug Discovery

view channel
Image: The European Commission has approved the use of Avastin combined with chemotherapy as a treatment for women with recurrent ovarian cancer (Photo courtesy of Genentech).

Drug for Treatment of Platinum Resistant Recurrent Ovarian Cancer Approved for Use in Europe

For the first time in more than 15 years the European Commission (EC) has approved a new therapeutic option for the most difficult to treat form of ovarian cancer. Ovarian cancer causes more deaths... Read more

Therapeutics

view channel
Image: This type of electronic pacemaker could become obsolete if induction of biological pacemaker cells by gene therapy proves successful (Photo courtesy of Wikimedia Commons).

Gene Therapy Induces Functional Pacemaker Cells in Pig Heart Failure Model

Cardiovascular disease researchers working with a porcine heart failure model have demonstrated the practicality of using gene therapy to replace implanted electronic pacemakers to regulate heartbeat.... Read more

Lab Technologies

view channel
Image: Neurons (greenish yellow) attach to silk-based scaffold (blue) creating functional networks throughout the scaffold pores (dark areas) (Photo courtesy of Tufts University).

Functional 3D Brain-Like Tissue Model Bioengineered

Researchers recently reported on the development of the first complex, three-dimensional (3D) model comprised of brain-like cortical tissue that displays biochemical and electrophysiologic responses, and... Read more

Business

view channel

Global Computational Biology Sector Expected to Reach over USD 4 Billion by 2020

The global market for computational biology is expected to reach USD 4.285 billion by 2020 growing at a compound annual growth rate (CAGR) of 21.1%, according to new market research. Steady surge in the usage and application of computational biology for bioinformatics R&D programs designed for sequencing genomes... Read more
 
Copyright © 2000-2014 Globetech Media. All rights reserved.