Prion-like proteins drive several diseases of aging

Self-propagating aggregates key to Alzheimer's, other diseases

2013-09-05

(Press-News.org) Two leading neurology researchers have proposed a theory that could unify scientists' thinking about several neurodegenerative diseases and suggest therapeutic strategies to combat them.

The theory and backing for it are described in Nature.

Mathias Jucker and Lary Walker outline the emerging concept that many of the brain diseases associated with aging, such as Alzheimer's and Parkinson's, are caused by specific proteins that misfold and aggregate into harmful seeds.

These seeds behave very much like the pathogenic agents known as prions, which cause mad cow disease, chronic wasting disease in deer, scrapie in sheep, and Creutzfeldt-Jakob disease in humans.

Walker is research professor at Yerkes National Primate Research Center, Emory University. Jucker is head of the Department of Cellular Neurology at the Hertie Institute for Clinical Brain Research at the University of Tübingen and the German Center for Neurodegenerative Diseases.

Unlike prion diseases, which can be infectious, Alzheimer's, Parkinson's, and other neurodegenerative diseases can not be passed from person to person under normal circumstances. Once all of these diseases take hold in the brain, however, it is increasingly apparent that the clumps of misfolded proteins spread throughout the nervous system and disrupt its function.

The authors were the first to show that a protein that is involved in Alzheimer's disease -- known as amyloid-beta -- forms prion-like seeds that stimulate the aggregation of other amyloid-beta molecules in senile plaques and in brain blood vessels. Since then, a growing number of laboratories worldwide have discovered that proteins linked to other neurodegenerative disorders also share key features with prions.

Age-related neurodegenerative disorders remain stubbornly resistant to the discovery of effective treatments. Jucker and Walker propose that the concept of pathogenic protein seeding not only could focus research strategies for these seemingly unrelated diseases, but it also suggests that therapeutic approaches designed to thwart prion-like seeds early in the disease process could eventually delay or even prevent the diseases.

###

ELSE PRESS RELEASES FROM THIS DATE:

400-year study finds Northeast forests resilient, changing

2013-09-05

A joint Harvard-Smithsonian study released today in the journal PLOS ONE reveals how much -- and how little -- Northeastern forests have changed after centuries of intensive land use. A hike through today's woods will reveal the same types of trees that a colonial settler would have encountered 400 years ago. But the similarities end there. Jonathan Thompson, research associate at the Smithsonian Conservation Biology Institute and lead author of the new study, explains, "If you only looked at a tree species list, you'd have the impression that Northeast forests haven't ...

Female tiger sharks migrate from Northwestern to Main Hawaiian Islands during fall pupping season

2013-09-05

A quarter of the mature female tiger sharks plying the waters around the remote coral atolls of the Northwestern Hawaiian Islands decamp for the populated Main Hawaiian Islands in the late summer and fall, swimming as far as 2,500 kilometers (1,500 miles) according to new research from University of Florida and the University of Hawaii. Their report is scheduled for publication in the November 2013 issue of Ecological Society of America's journal Ecology. The authors' manuscript is available as a preprint. "When we think of animal migrations, we tend to think of all individuals ...

Overgrazing turning parts of Mongolian Steppe into desert

2013-09-05

CORVALLIS, Ore. – Overgrazing by millions of sheep and goats is the primary cause of degraded land in the Mongolian Steppe, one of the largest remaining grassland ecosystems in the world, Oregon State University researchers say in a new report. Using a new satellite-based vegetation monitoring system, researchers found that about 12 percent of the biomass has disappeared in this country that's more than twice the size of Texas, and 70 percent of the grassland ecosystem is now considered degraded. The findings were published in Global Change Biology. Overgrazing accounts ...

Peering into genetic defects, CU scientists discover a new metabolic disease

2013-09-05

An international team of scientists, including University of Colorado School of Medicine and Children's Hospital Colorado researchers, has discovered a new disease related to an inability to process Vitamin B12. The disorder is rare but can be devastating. "Some people with rare inherited conditions cannot process vitamin B 12 properly," says CU researcher Tamim Shaikh, PhD, a geneticist and senior author of a paper about the new disease. "These individuals can end up having serious health problems, including developmental delay, epilepsy, anemia, stroke, psychosis and ...

Researchers determine digestibility of blood products as feed in weanling pigs

2013-09-05

URBANA, Ill. - Because weanling pigs do not tolerate great quantities of soybean meal in the diet, alternative sources of protein must be used. Blood products, such as blood meal and plasma protein, are common ingredients in weanling pig diets and are considered high-quality sources of amino acids. Researchers at the University of Illinois have determined the amino acid digestibility of five blood products produced in the U.S. to provide swine producers with guidance for the use of these products in formulating diets. "Blood meal usually is considered a good source of ...

Deep-ocean carbon sinks

2013-09-05

Although microbes that live in the so-called "dark ocean"—below a depth of some 600 feet where light doesn't penetrate—may not absorb enough carbon to curtail global warming, they do absorb considerable amounts of carbon and merit further study. That is one of the findings of a paper published in the International Society of Microbial Ecology (ISME) Journal by Tim Mattes, associate professor of civil and environmental engineering in the University of Iowa College of Engineering, and his colleagues. Mattes says that while many people are familiar with the concept of ...

DNA changes during pregnancy persist into childhood

2013-09-05

Even before they are born, babies accumulate changes in their DNA through a process called DNA methylation that may interfere with gene expression, and in turn, their health as they grow up. But until now it's been unclear just how long these changes during the prenatal period persist. In a new study, researchers at the Columbia Center for Children's Environmental Health at the Mailman School of Public Health establish that signs of DNA methylation persist through early childhood, suggesting the factors that influence these changes during or before pregnancy could have ...

Hibernating lemurs hint at the secrets of sleep

2013-09-05

DURHAM, N.C. -- By studying hibernation, a Duke University team is providing a window into why humans sleep. Observations of a little-known primate called the fat-tailed dwarf lemur in captivity and the wild has revealed that it goes for days without the deepest part of sleep during its winter hibernation season. The findings support the idea that sleep plays a role in regulating body temperature and metabolism. Despite decades of research, why we sleep is still a mystery. Theories range from conserving energy, to processing information and memories, to removing toxins ...

Exercise may reduce the risk of epilepsy later in life for men

2013-09-05

MINNEAPOLIS -- New research suggests that men who exercise vigorously as young adults may reduce their risk of developing epilepsy later in life. The study is published in the September 4, 2013, online issue of Neurology®, the medical journal of the American Academy of Neurology. Epilepsy is a brain disease that causes repeated seizures over time. "There are a host of ways exercise has been shown to benefit the brain and reduce the risk of brain diseases," said study author Elinor Ben-Menachem, PhD, MD, with the University of Gothenburg in Sweden and an associate member ...

Biology texts geared toward pre-med students, analysis finds

2013-09-05

COLUMBUS, Ohio -- College biology textbooks cater to the needs of pre-med majors and not those of the majority of students who take introductory science classes, a new study reveals. A text analysis of eight commonly used biology textbooks found that all of them closely follow the curriculum suggested for pre-med students by the Medical College Admission Test (MCAT). That means the texts put a heavy emphasis on molecular and cellular biology, while giving less attention to the big issues that have more relevance to students who don't plan on being medical doctors, ...

Data from Poland, Indonesia and Nepal indicate that affectionate behavior is associated with higher relationship satisfaction - though cultural differences impact how affection is displayed and percei

"Boomerang" made from mammoth tusk is likely one of the oldest known in Europe at around 40,000 years old, per analysis of this artifact from a Polish Upper Paleolithic cave

Prion-like proteins drive several diseases of aging

ELSE PRESS RELEASES FROM THIS DATE:

LAST 30 PRESS RELEASES: