Gas-blockers might slow down Alzheimer's disease

October 31, 2005

A noxious gas speeds up brain degeneration in Alzheimer's disease, according to a study in the November 7 issue of The Journal of Experimental Medicine. Carl Nathan and colleagues at Cornell University Weill Medical College found that an enzyme that triggers the production of nitric oxide (NO) -- a gas that helps immune cells fight off invading pathogens -- accelerates the formation of brain lesions in Alzheimer's-prone mice. The study suggests that inhibitors of this enzyme (called iNOS) -- which have already been produced and tested in humans -- might be a promising and thus far overlooked therapy for the treatment of this devastating disease.

Alzheimer's disease is a lethal neurodegenerative disease that causes progressive memory loss and dementia. The disease is associated with a build-up in the brain of abnormal fragments of a resident brain protein called beta-amyloid protein. Researchers have not yet figured out exactly how the fragments of this protein (referred to as A-beta) cause disease, but they have some clues.

One clue is the fact that A-beta causes brain cells to make iNOS. This enzyme is normally turned on during infection and is needed to help immune cells destroy invading pathogens. But iNOS is not normally found in the brain. There, the enzyme may cause cellular damage that destroys neurons.

For nearly a decade, researchers have known that iNOS was present in the brain lesions of patients with Alzheimer's disease, but nobody had addressed whether its presence was making the disease worse. Nathan and colleagues now show that Alzheimer's-prone mice that lack iNOS live twice as long and develop fewer brain lesions than iNOS-expressing mice. Both groups of mice developed some brain lesions initially, but the iNOS-deficient mice were spared the rapid accumulation of lesions later in life.

Based on these results, Nathan suggests that iNOS inhibitors might turn out to be more effective than current therapies for Alzheimer's disease, which temporarily improve performance on cognitive tests, but do not increase survival.
-end-


Journal of Experimental Medicine

Related Brain Articles from Brightsurf:

Glioblastoma nanomedicine crosses into brain in mice, eradicates recurring brain cancer
A new synthetic protein nanoparticle capable of slipping past the nearly impermeable blood-brain barrier in mice could deliver cancer-killing drugs directly to malignant brain tumors, new research from the University of Michigan shows.

Children with asymptomatic brain bleeds as newborns show normal brain development at age 2
A study by UNC researchers finds that neurodevelopmental scores and gray matter volumes at age two years did not differ between children who had MRI-confirmed asymptomatic subdural hemorrhages when they were neonates, compared to children with no history of subdural hemorrhage.

New model of human brain 'conversations' could inform research on brain disease, cognition
A team of Indiana University neuroscientists has built a new model of human brain networks that sheds light on how the brain functions.

Human brain size gene triggers bigger brain in monkeys
Dresden and Japanese researchers show that a human-specific gene causes a larger neocortex in the common marmoset, a non-human primate.

Unique insight into development of the human brain: Model of the early embryonic brain
Stem cell researchers from the University of Copenhagen have designed a model of an early embryonic brain.

An optical brain-to-brain interface supports information exchange for locomotion control
Chinese researchers established an optical BtBI that supports rapid information transmission for precise locomotion control, thus providing a proof-of-principle demonstration of fast BtBI for real-time behavioral control.

Transplanting human nerve cells into a mouse brain reveals how they wire into brain circuits
A team of researchers led by Pierre Vanderhaeghen and Vincent Bonin (VIB-KU Leuven, Université libre de Bruxelles and NERF) showed how human nerve cells can develop at their own pace, and form highly precise connections with the surrounding mouse brain cells.

Brain scans reveal how the human brain compensates when one hemisphere is removed
Researchers studying six adults who had one of their brain hemispheres removed during childhood to reduce epileptic seizures found that the remaining half of the brain formed unusually strong connections between different functional brain networks, which potentially help the body to function as if the brain were intact.

Alcohol byproduct contributes to brain chemistry changes in specific brain regions
Study of mouse models provides clear implications for new targets to treat alcohol use disorder and fetal alcohol syndrome.

Scientists predict the areas of the brain to stimulate transitions between different brain states
Using a computer model of the brain, Gustavo Deco, director of the Center for Brain and Cognition, and Josephine Cruzat, a member of his team, together with a group of international collaborators, have developed an innovative method published in Proceedings of the National Academy of Sciences on Sept.

Read More: Brain News and Brain Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.