Navigation Links
Neuron-nourishing cells appear to retaliate in Alzheimer's
Date:5/22/2012

AUGUSTA, Ga. When brain cells start oozing too much of the amyloid protein that is the hallmark of Alzheimer's disease, the astrocytes that normally nourish and protect them deliver a suicide package instead, researchers report.

Amyloid is excreted by all neurons, but rates increase with aging and dramatically accelerate in Alzheimer's. Astrocytes, which deliver blood, oxygen and nutrients to neurons in addition to hauling off some of their garbage, get activated and inflamed by excessive amyloid.

Now researchers have shown another way astrocytes respond is by packaging the lipid ceramide with the protein PAR-4, which independently can do damage but together are a more "deadly duo," said Dr. Erhard Bieberich, biochemist at the Medical College of Georgia at Georgia Health Sciences University.

"If the neuron makes something toxic and dumps it at your door, what would you do?" said Bieberich, corresponding author of the study published in the Journal of Biological Chemistry. "You would probably do something to defend yourself."

The researchers hypothesize that this lipid-coated package ultimately kills them both, which could help explain the brain-cell death and shrinkage that occurs in Alzheimer's. "If the astrocytes die, the neurons die," Bieberich said, noting studies suggest that excess amyloid alone does not kill brain cells. "There must be a secondary process toxifying the amyloid; otherwise the neuron would self-intoxicate before it made a big plaque," he said. "The neuron would die first."

One of many avenues for future pursuit include whether a ceramide antibody could be a viable Alzheimer's treatment. In the researchers' studies of brain cells of humans with Alzheimer's as well as an animal model of the disease, antibodies to ceramide and Par-4 prevented astrocytes' amyloid-induced death.

Ceramide and Par-4 get packaged in lipid-coated vesicles called exosomes; all cells secrete thousands of these vesicles but scientists are only beginning to understand their normal function. When exosomes become deadly, they are called apoxosomes.

Ceramide and Par-4 are typically not in a vesicle, rather in two distinct parts of a cell. Ceramide appears to take the lead in bringing the two together when confronted with amyloid. Bieberich and colleagues at the University of Georgia reported in 2003 that the deadly duo helps eliminate duplicate brain cells that occur early in brain development when their survival could result in a malformed brain. They suspected then that the duo might also have a role in Alzheimer's.

Risk factors for Alzheimer's include aging, family history and genetics, according to the Alzheimer's Association. Increasing evidence suggests that Alzheimer's also shares many of the same risk factors for cardiovascular disease, such as high cholesterol, high blood pressure and inactivity.


'/>"/>
Contact: Toni Baker
tbaker@georgiahealth.edu
706-721-4421
Georgia Health Sciences University
Source:Eurekalert  

Related medicine news :

1. Study: Heart damage after chemo linked to stress in cardiac cells
2. Scientists discover marker to identify, attack breast cancer stem cells
3. All cancer cells are not created equal
4. Drug kills cancer cells by restoring faulty tumor suppressor
5. Rutgers team discovers novel approach to stimulate immune cells
6. Mayo Clinic: Exhaustion renders immune cells less effective in cancer treatment
7. Cancer Cells in Bloodstream Show Great Diversity: Study
8. Scripps Research scientists show how memory B cells stay in class to fight different infections
9. Gut flora affects maturation of B cells in infants
10. Researchers Rejuvenate Blood-Forming Stem Cells in Mice
11. Presence of fetal cells in women lowers risk of breast cancer but raises risk of colon cancer
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Neuron-nourishing cells appear to retaliate in Alzheimer's
(Date:5/26/2016)... ... 26, 2016 , ... There are many ways to cook a hot dog, ... that Americans prefer their dogs straight off the grill. Of the 90 percent of ... way to cook a hot dog, far outpacing other cooking methods such as steaming ...
(Date:5/26/2016)... ... 2016 , ... Connor Sports, through its Connor Cares initiative, will ... Tamika Catchings Legacy Tour that will commemorate the Indiana Fever legend’s hall-of-fame career ... all forms and levels of the game, Connor Sports has committed to a significantly ...
(Date:5/26/2016)... ... May 26, 2016 , ... MadgeTech will be showcasing ... and manufactured in Warner, New Hampshire at the MadgeTech headquarters. With products sold in ... solutions trusted by government agencies, including NASA. , In 2012, NASA strategically set ...
(Date:5/26/2016)... ... ... Memorial Day Weekend marks the unofficial start of summer and the beginning ... sure your family and vehicle are ready to hit the road this weekend. , ... and an additional 50,500 serious injuries from motor vehicle crashes during the three-day Memorial ...
(Date:5/26/2016)... ... May 26, 2016 , ... Nike ... of activities from daily practices, arts & crafts, discussions, and games all geared ... and Christy Evans have combined backgrounds in kids’ yoga, collegiate sport yoga instruction, ...
Breaking Medicine News(10 mins):
(Date:5/25/2016)... NORTH CHESTERFIELD, Va. , May 25, 2016 ... commercially-available next-generation sequencing test for wounds and infections. ... fungi, ALL parasites, and select viruses. The test ... infected area. David G. ... advanced molecular testing to facilitate wound healing: "We ...
(Date:5/25/2016)... May 25, 2016 Inivata, ... precision of circulating tumour DNA (ctDNA) analysis to ... appointment of Professor Clive Morris as ... across the clinical development programme, scientific collaborations, and ... deliver significant improvements in clinical outcomes for patients. ...
(Date:5/24/2016)... 24, 2016 Cirujanos holandeses han ... a los médicos a compartir sus mejores prácticas por ... mundial. Profesionales médicos de Europa, África, Asia ... a la aplicación, que combina la transmisión en vivo ... seguro. Educación   "Imagine un médico ...
Breaking Medicine Technology: