PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

New findings regarding DNA damage checkpoint mechanism in oxidative stress

2013-06-14
(Press-News.org) In current health lore, antioxidants are all the rage, as "everybody knows" that reducing the amount of "reactive oxygen species" -- cell-damaging molecules that are byproducts of cellular metabolism -- is critical to staying healthy. What everyone doesn't know is that our bodies already have a complex set of processes built into our cells that handle these harmful byproducts of living and repair the damage they cause.

For example, few of us realize that, while our cells' DNA is constantly being damaged by reactive oxygen species (as well as by other forces), there are also complex mechanisms that constantly assess that damage and make repairs to our fragile genetic material at least 10,000 times a day in every cell in our bodies. The vital biochemical processes by which this constant DNA repair takes place are still only partially understood because of their complexity, speed, and the difficulty of studying complex interactions within living cells. Moreover, it remains unknown how cells sense the oxidatively damaged DNA in the first place.

In an article published in the Proceedings of the National Academy of Sciences (PNAS) a research team from University of North Carolina at Charlotte announced that they had uncovered a previously unknown surveillance mechanism, known as a DNA damage checkpoint, used by cells to monitor oxidatively damaged DNA. The finding, first-authored by UNC Charlotte biology graduate student Jeremy Willis and undergraduate honors student Yogin Patel, was also co-authored by undergraduate honors student Barry L. Lentz and assistant professor of biology Shan Yan.

"DNA damage is the underlying pathology in many major human diseases, including cancers and neurodegenerative disorders such as Alzheimer's and Parkinson's, so arriving at a full understanding of the sophisticated mechanisms that cells usually employ to avoid such disastrous outcomes is important," Yan noted.

Two biochemical pathways, known as ATM-Chk2 and ATR-Chk1, govern the cell's response and repair of double-strand DNA breaks and other types of DNA damage or replication stress respectively. The molecular mechanisms underlying the ATR-Chk1 checkpoint activation include the uncoupling of DNA helicase and polymerase activities and DNA end resection of double-strand breaks.

"The significance of what we have found is that there is a third, previously unknown trigger for ATR-Chk1 checkpoint pathway, and this novel mechanism is discovered in the context of oxidative stress," Yan said.

In particular, Yan's team discovered that under conditions of oxidative stress (in the presence of hydrogen peroxide) a base excision repair protein known as APE2 plays unexpected roles in the checkpoint response: single-strand DNA generation and Chk1 association. The protein was previously known to be involved in the DNA repair of oxidative damage, but not to extent revealed in the study's findings. The distinct role of APE2 in the single-strand DNA generation in 3' to 5' direction is referred to as single-strand break end resection ("SSB end resection") by the authors.

The study involved experiments performed with Xenopus laves (the African clawed frog, a species commonly used as a lab animal) egg extracts – an experimental system that Yan's lab has developed for studying DNA repair and checkpoint mechanisms in a cell-free conditions. Xenopus is useful because it is a vertebrate (and thus quite similar to humans in cell biology), and its egg cells can be easily produced and manipulated.

Yan is hopeful that this research will open new avenues to pharmacological strategies in drug development for cancer and neurodegenerative diseases.

###

The article appeared in the June 10, 2013 print edition of PNAS: http://www.pnas.org/content/early/2013/06/06/1301445110.abstract.

The Yan laboratory at UNC Charlotte is funded in part by the University of North Carolina at Charlotte and a National Institute of General Medical Sciences/National Institutes of Health grant, number R15GM101571.


ELSE PRESS RELEASES FROM THIS DATE:

Genome decoding of the medieval leprosy pathogen

2013-06-14
From skeletons and biopsies, an international team of scientists was successful in reconstructing a dozen medieval and modern genomes of the leprosy-causing bacteria Mycobacterium leprae. Under the direction of Professor Johannes Krause, University of Tübingen, and Professor Stewart Cole, Swiss Federal Institute of Technology of Lausanne (EPFL), the research group created a genome from archaeological finds for the first time without having to resort to a reference sequence. Professor Almut Nebel and Dr. Ben Krause-Kyora, both of the Institute of Clinical Molecular Biology, ...

Automated 'coach' could help with social interactions

2013-06-14
CAMBRIDGE, MA -- Social phobias affect about 15 million adults in the United States, according to the National Institute of Mental Health, and surveys show that public speaking is high on the list of such phobias. For some people, these fears of social situations can be especially acute: For example, individuals with Asperger's syndrome often have difficulty making eye contact and reacting appropriately to social cues. But with appropriate training, such difficulties can often be overcome. Now, new software developed at MIT can be used to help people practice their interpersonal ...

Berkeley Lab team uncovers secrets of biological soil crusts

2013-06-14
They lie dormant for years, but at the first sign of favorable conditions they awaken. This sounds like the tagline for a science fiction movie, but it describes the amazing life-cycles of microbial organisms that form the biological soil crusts (BSCs) of Earth's deserts. Now a research team with the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab) has reported a unique molecular-level analysis of a BSC cyanobacterium responding to the wetting and drying of its environment. The results hold implications for land management, improved ...

Researchers unearth bioenergy potential in leaf-cutter ant communities

2013-06-14
MADISON-— As spring warms up Wisconsin, humans aren't the only ones tending their gardens. At the University of Wisconsin–Madison Department of Bacteriology, colonies of leaf-cutter ants cultivate thriving communities of fungi and bacteria using freshly cut plant material. While these fungus gardens are a source of food and shelter for the ants, for researchers, they are potential models for better biofuel production. "We are interested in the whole fungus garden community, because a lot of plant biomass goes in and is converted to energy for the ants," says Frank ...

Scientists at UMass Medical School identify neurons that control feeding behavior in Drosophila

2013-06-14
WORCESTER – Scientists at the University of Massachusetts Medical School have developed a novel transgenic system which allows them to remotely activate individual brain cells in the model organism Drosophila using ambient temperature. This powerful new tool for identifying and characterizing neural circuitry has lead to the identification of a pair of neurons – now called Fdg neurons – in the fruit fly that decide when to eat and initiate the subsequent feeding action. Discovery of these neurons may help neurobiologists better understand how the brain uses memory and stimuli ...

UCLA climate study predicts dramatic loss in local snowfall

2013-06-14
By midcentury, snowfall on Los Angeles–area mountains will be 30 to 40 percent less than it was at the end of the 20th century, according to a UCLA study released today and led by UCLA climate expert Alex Hall. The projected snow loss, a result of climate change, could get even worse by the end of the 21st century, depending on how the world reacts. Sustained action to reduce global greenhouse gas emissions could keep annual average snowfall levels steady after mid-century, but if emissions continue unabated, the study predicts that snowfall in Southern California mountains ...

Researchers solve mystery of X-ray light from black holes

2013-06-14
It is a mystery that has stymied astrophysicists for decades: how do black holes produce so many high-power X-rays? In a new study, astrophysicists from The Johns Hopkins University, NASA and the Rochester Institute of Technology bridged the gap between theory and observation by demonstrating that gas spiraling toward a black hole inevitably results in X-ray emissions. The paper states that as gas spirals toward a black hole through a formation called an accretion disk, it heats up to roughly 10 million degrees Celsius. The temperature in the main body of the disk ...

Male preference for younger female mates identified as likely cause of menopause

2013-06-14
A study published in this week's PLOS Computational Biology reports that menopause is an unintended outcome of natural selection caused by the preference of males for younger female mates. While conventional thinking has held that menopause prevents older women from continuing to reproduce, the researchers, from McMaster's University, concluded that it is the lack of reproduction that has given rise to menopause. The researchers found that, over time, competition among men of all ages for younger mates has left older females with much less chance of reproducing. The pressures ...

Finasteride, medication for male pattern hair loss, may also decrease drinking

2013-06-14
Contact: Michael S. Irwig mirwig@mfa.gwu.edu 202-741-2489 The George Washington University Contact: Chuck Zorumski zorumskc@psychiatry.wustl.edu 314-286-1700 Washington University School of Medicine Alcoholism: Clinical & Experimental Research Finasteride, medication for male pattern hair loss, may also decrease drinking Finasteride is a synthetic drug for the treatment of male pattern hair loss and an enlarged prostate. Rodent research has shown that finasteride can reduce alcohol intake. A preliminary study of men with finasteride-related sexual ...

Chronic drinking + exposure to particulate matter dramatically decreases lung function

2013-06-14
Contact: Stephania A. Cormier scorm1@lsuhsc.edu 504-568-2810 Louisiana State University Health Sciences Center Contact: George Leikauf gleikauf@pitt.edu 412-383-5305 University of Pittsburgh Alcoholism: Clinical & Experimental Research Chronic drinking + exposure to particulate matter dramatically decreases lung function Alveolar macrophage (AM) function plays a critical role in protecting the lungs by removing particulates. Chronic drinking causes persistent oxidative stress in the lungs, leading to impaired AM function. A new rodent study shows that ...

LAST 30 PRESS RELEASES:

Scientists track evolution of pumice rafts after 2021 underwater eruption in Japan

The future of geothermal for reliable clean energy

Study shows end-of-life cancer care lacking for Medicare patients

Scented wax melts may not be as safe for indoor air as initially thought, study finds

Underwater mics and machine learning aid right whale conservation

Solving the case of the missing platinum

Glass fertilizer beads could be a sustained nutrient delivery system

Biobased lignin gels offer sustainable alternative for hair conditioning

Perovskite solar cells: Thermal stresses are the key to long-term stability

University of Houston professors named senior members of the National Academy of Inventors

Unraveling the mystery of the missing blue whale calves

UTA partnership boosts biomanufacturing in North Texas

Kennesaw State researcher earns American Heart Association award for innovative study on heart disease diagnostics

Self-imaging of structured light in new dimensions

Study highlights successes of Virginia’s oyster restoration efforts

Optimism can encourage healthy habits

Precision therapy with microbubbles

LLM-based web application scanner recognizes tasks and workflows

Pattern of compounds in blood may indicate severity of gestational hypertension and preeclampsia

How does innovation policy respond to the challenges of a changing world?

What happens when a diet targets ultra-processed foods?

University of Vaasa, Finland, conducts research on utilizing buildings as energy sources

Stealth virus: Zika virus builds tunnels to covertly infect cells of the placenta

The rising tide of sand mining: a growing threat to marine life

Contemporary patterns of end-of-life care among Medicare beneficiaries with advanced cancer

Digital screen time and nearsightedness

Postoperative weight loss after anti-obesity medications and revision risk after joint replacement

New ACS research finds low uptake of supportive care at the end-of-life for patients with advanced cancer

New frailty measurement tool could help identify vulnerable older adults in epic

Co-prescribed stimulants, opioids linked to higher opioid doses

[Press-News.org] New findings regarding DNA damage checkpoint mechanism in oxidative stress