 |
|
How oxidative stress may help prolong life
May 29, 2009Oxidative stress has been linked to aging, cancer and other diseases in humans. Paradoxically, researchers have suggested that small exposure to oxidative conditions may actually offer protection from acute doses. Now, scientists at the University of California, San Diego, have discovered the gene responsible for this effect. Their study, published in PLoS Genetics on May 29, explains the underlying mechanism of the process that prevents cellular damage by reactive oxygen species (ROS).
"We may drink pomegranate juice to protect our bodies from so-called 'free radicals' or look at restricting calorie intake to extend our lifespan," said Trey Ideker, PhD, chief of the Division of Genetics in the Department of Medicine at UC San Diego's School of Medicine and professor of bioengineering at the Jacobs School of Engineering. "But our study suggests why humans may actually be able to prolong the aging process by regularly exposing our bodies to minimal amounts of oxidants."
Reactive oxygen species (ROS), ions that form as a natural byproduct of the metabolism of oxygen, play important roles in cell signaling. These very small molecules include oxygen ions, free radicals and peroxides. However, during times of environmental stress (for example, ultraviolet radiation or heat or chemical exposure), ROS levels can increase dramatically. This can result in significant damage to cellular damage to DNA, RNA and proteins - cumulating in an effect called oxidative stress.
One major contributor to oxidative stress is hydrogen peroxide, converted from a type of free radical that leaks from the mitochondria as it produces energy. While the cell has ways to help minimize the damaging effects of hydrogen peroxide by converting it to oxygen and water, this conversion isn't 100 percent successful.
Ideker and first author Ryan Kelley used the rich functional genomics toolbox of yeast to identify pathways involved in the cell's adaption to hydrogen peroxide. Adaption (or hormesis) is an effect where a toxic substance acts like a stimulant in small doses, but is an inhibitor in large doses.
To shed light on the molecular mechanisms of adaptation, Ideker and Kelley designed a way to identify genes involved in adaptation to hydrogen peroxide. They elicited adaptation by pre-treating cells with a mild dose of hydrogen peroxide, followed by a high dose. They observed that the cells undergoing this adaptation protocol exhibited a smaller reduction in viability than cells exposed to only an acute treatment protocol (in which about half of the cells died.)
To figure out which genes might control this adaptation mechanism, Kelley and Ideker ran a series of experiments in which cells were forced to adapt while each gene in the genome was removed, one by one - covering a total of nearly 5,000 genes. By systematically removing genes, they identified a novel factor called Mga2 - and discovered that this transcription factor is essential for adaptation.
"This was a surprise, because Mga2 is found at the control point of a completely different pathway than those which respond to acute exposure of oxidative agents," said Ideker. "This second pathway is only active at lower doses of oxidation."
This finding may explain recent studies suggesting that eating less may, in fact, raise ROS levels - and, in doing so, provide protection from acute doses of oxidants. This is counter to the hypothesis that caloric restriction extends lifespan in some species because it reduces ROS produced as a by-product of the energy regenerated by mitochondria.
"It may be that adaption to oxidative stress is the main factor responsible for the lifespan-expanding effects of caloric restriction," said Ideker. "Our next step is to figure out how Mga2 works to create a separate pathway - to discover the upstream mechanism that senses low doses of oxidation and triggers a protective mechanism downstream." Further efforts to understand this process may have broad implications on models of aging and disease.
University of California - San Diego
One major contributor to oxidative stress is hydrogen peroxide, converted from a type of free radical that leaks from the mitochondria as it produces energy. While the cell has ways to help minimize the damaging effects of hydrogen peroxide by converting it to oxygen and water, this conversion isn't 100 percent successful.
Ideker and first author Ryan Kelley used the rich functional genomics toolbox of yeast to identify pathways involved in the cell's adaption to hydrogen peroxide. Adaption (or hormesis) is an effect where a toxic substance acts like a stimulant in small doses, but is an inhibitor in large doses.
To shed light on the molecular mechanisms of adaptation, Ideker and Kelley designed a way to identify genes involved in adaptation to hydrogen peroxide. They elicited adaptation by pre-treating cells with a mild dose of hydrogen peroxide, followed by a high dose. They observed that the cells undergoing this adaptation protocol exhibited a smaller reduction in viability than cells exposed to only an acute treatment protocol (in which about half of the cells died.)
To figure out which genes might control this adaptation mechanism, Kelley and Ideker ran a series of experiments in which cells were forced to adapt while each gene in the genome was removed, one by one - covering a total of nearly 5,000 genes. By systematically removing genes, they identified a novel factor called Mga2 - and discovered that this transcription factor is essential for adaptation.
"This was a surprise, because Mga2 is found at the control point of a completely different pathway than those which respond to acute exposure of oxidative agents," said Ideker. "This second pathway is only active at lower doses of oxidation."
This finding may explain recent studies suggesting that eating less may, in fact, raise ROS levels - and, in doing so, provide protection from acute doses of oxidants. This is counter to the hypothesis that caloric restriction extends lifespan in some species because it reduces ROS produced as a by-product of the energy regenerated by mitochondria.
"It may be that adaption to oxidative stress is the main factor responsible for the lifespan-expanding effects of caloric restriction," said Ideker. "Our next step is to figure out how Mga2 works to create a separate pathway - to discover the upstream mechanism that senses low doses of oxidation and triggers a protective mechanism downstream." Further efforts to understand this process may have broad implications on models of aging and disease.
University of California - San Diego
Oxidative Stress Current Events and Oxidative Stress News RSSScientists find molecular trigger that helps prevent aging and disease
Researchers at Mount Sinai School of Medicine set out to address a question that has been challenging scientists for years: How do dietary restriction-and the reverse, overconsumption-produce protective effects against aging and disease?
'Escaped' proteins add to hearing loss in elderly, UF researchers find
Age-related hearing loss is the most common sensory disorder among the elderly. But scientists are still trying to figure out what cellular processes govern or contribute to the loss.
Pathogen protection and virulence: Dark side of fungal membrane protein revealed
Researchers at the Virginia Bioinformatics Institute (VBI) at Virginia Tech and Montana State University have discovered a fungal protein that plays a key role in causing disease in plants and animals and which also shields the pathogen from oxidative stress.
Reduction in glycotoxins from heat-processing of foods reduces risk of chronic disease
Researchers from Mount Sinai School of Medicine report that cutting back on the consumption of processed and fried foods, which are high in toxins called Advanced Glycation End products (AGEs), can reduce inflammation and actually help restore the body's natural defenses regardless of age or health status.
Phytochemicals in plant-based foods could help battle obesity, disease
The cheeseburger and French fries might look tempting, but eating a serving of broccoli or leafy greens first could help people battle metabolic processes that lead to obesity and heart disease, a new University of Florida study shows.
Study: Added oxygen during stroke reduces brain tissue damage
Scientists have countered findings of previous clinical trials by showing that giving supplemental oxygen to animals during a stroke can reduce damage to brain tissue surrounding the clot.
APP -- Good, bad or both?
New data about amyloid precursor protein, or APP, a protein implicated in development of Alzheimer's disease, suggests it also may have a positive role -- directly affecting learning and memory during brain development.
Nanotech protection
Writing in a forthcoming issue of the International Journal of Nanotechnology, Canadian engineers suggest that research is needed into the risks associated with the growing field of nanotechnology manufacture so that appropriate protective equipment can be developed urgently.
Reactive oxygen in fruit flies acts as a cell signalling mechanism for immune response
For years, health conscious people have been taking antioxidants to reduce the levels of reactive oxygen in their blood and prevent the DNA damage done by free radicals, which are the result of oxidative stress. But could excessive use of antioxidants deplete our immune systems?
New method monitors early sign of oxidative stress in cancer
The growth of cancerous tumors is fueled, at least in part, by the buildup of free radicals-highly reactive oxygen-containing molecules.
More Oxidative Stress Current Events and Oxidative Stress News Articles
 |
Autism: Oxidative Stress, Inflammation, and Immune Abnormalities by Abha Chauhan (Author), Ved Chauhan (Author), Ted Brown (Author) Recently, the CDC issued an alert indicating that autism may impact one out of every150 children. While the syndrome is still officially labeled as idiopathic, research shows the cause of autism may possess genetic, environmental, and possibly immunological factors and that it has at least a correlation to oxidative stress. This book collects work from researchers working at the frontier of neuroscience and medicine who report on evidence indicating links between autism and a number of oxidative stress-related abnormalities such as neuroinflammation, mitochondrial dysfunction, membrane and metabolism abnormalities, and signal transduction. The text also reports on potential avenues for new therapeutic intervention strategies. |
 |
Life Time Renu-Time, Oxidative Stress Complex, 60 Capsules by ClubNatural by ClubNatural Supplement Facts Serving Size 2 Capsules Servings Per Container 30 Amount Per Serving % Daily Value* Ashwaghanda 5% PE (standardized to contain 5% withanolides) (Withania somnifera) (root) 250 mg * Green Tea Extract (standardized to contain 90% polyphenols and 60% epigallocatechin gallate) (Camellia sinensis) (leaf) 250 mg * Milk Thistle Extract (standardized to contain 80% silymarin) (Silybum marianum) (root) 250 mg * Turmeric Extract (standardized to contain 95% curcuminoids)(Curcuma Longa)(root) 250 mg * Bacopa Extract (standardized to contain 50% bacosides A/B) (Bacopa monnierri) (leaf) 100 mg * Grape Seed Extract (standardized to contain 95% proanthocyanidins) (Vitis vinifera) (seed) 25 mg * Pine Bark Extract (standardized to contain 85%... |
 |
ABC News Primetime Getting an Edge: Shortcuts to Health Learn about an all-natural pill that some hope could turn back the clock on certain body chemicals -- researchers hope that one day it may help us live longer and avoid certain diseases; a boost for the brain that students are taking as if it were a harmless study aid, but which is, in fact, a prescription medicine that can be addictive; herbal supplements that claim to enhance men's sexual experience... From the classroom to the bedroom, it seems that Americans are more determined than ever to get an edge in their quest for health, success and pleasure. ABC News investigates natural supplements that promise dramatic male sexual enhancement. Then, meet a college student who, like thousands of her peers, has found a new way to improve her concentration during her stressful finals week... |
 |
Ilizarov Technique for Complex Foot and Ankle Deformities (Oxidative Stress and Disease) by Kirienko/Villa/ (Author) Reveals advanced methods of correcting foot deformities using the Ilizarov technique. Topics span approaches to the equines foot, hindfoot deformities, adduction, the cavus foot, artrorsi, arthrodesis, multi-component foot deformities, and more. |
 |
Carnosine and Oxidative Stress in Cells and Tissues by Alexander A. Boldyrev (Author) The main aim of this new book is to summarise the knowledge on the metabolic transformation of carnosine in excitable tissues of animals and human beings and to analyse the nature of its biological activity. At the beginning of monograph, the short history of the problem is stated. Distribution of carnosine in tissues, its appearance in ontogeny of vertebrates and correlation between carnosine content and functional activity of tissues are discussed. Chemical properties of carnosine and its natural derivatives and their ability to bind heavy metals and protons in water solution are documented.Special attention is paid to free radical quenching ability and to anti-glycating action. Biological activity of carnosine and carnosine containing compounds was tested using biological models of... |
 |
Radical Fruits 60 Cplts by Garden Of Life Radical Fruits is unlike other readily available antioxidant formulas, many of which have isolated single nutrients. This Garden of Life formula is a 100% natural blend of 10 antioxidant-rich fruits and alkalizing minerals that support overall health, and select ingredients are pre-digested using the proprietary Poten-Zyme process to make them more bioavailable to the body. Additionally, for those concerned with sugar intake, Radical Fruits contains only three grams of carbohydrates per serving. |
 |
An Introduction to Vitamins, Minerals and Oxidative Stress: The Role of Micronutrients and Reactive Oxygen Species in Normal and Pathological Processes by Stefan A. Hulea (Author) This book presents in simple and concise terms the biological functions of vitamins and minerals, what makes them essential to life and why they must be replenished daily from food. The best food sources for these micronutrients and the daily recommended intakes of vitamins and minerals are also presented. Information on these important micronutrients is all presented in one place (Part I) as opposed to the current text books where it is scattered throughout the text, making its retrieval tedious and time-consuming. In addition, the trace elements get an adequate coverage in contrast to the current texts. The second part introduces the reader to the concept of oxidative stress and the role of free radicals (mainly of oxygen and nitrogen) in the regulation of several biological... |
 |
Oxidative Stress in Cancer, AIDS, and Neurodegenerative Diseases (Oxidative Stress and Disease, 1) by Montagnier (Author) Presents basic, chemical, biological, and medical studies of free radicals on different targets and the consequences of their reactivity-covering the chemistry and biochemistry of free radicals, free radicals as second messengers that group the activation of transcription factors and enzymes, the importance of the antioxidant system in cell metabolism regulation, and the role of free radicals and antioxidants in disease management. Written by over 200 international authorities, the book offers incisive discussions on the significance of oxidant-antioxidant balance and cytotoxicity of free radicals when produced in excess by several sources, specifically radiation hydrogen peroxide as a stimulant of transcription factor NFkB leading to cell response against oxidative stress ... |
 |
Free Radical LPO Test Kit by Sunyu The level of free radicals, or unstable atoms in the body in general reflects the level of toxicity or unhealthy contaminants within the body. The LPO at-home urine test allows you to determine the amount of stress on the body caused by free radical activity. People who are undergoing ionic foot detoxification treatments or who want to assess their diet or nutritional supplements can benefit from measuring the levels of free radicals in the body. The LPOKit measures the level of free radicals or lipid peroxidation in the body, thus reflecting the body's relative level of aging. * Tests for the presence of MDA metabolite which is produced from free radicals * The testing process is easy, accurate and safe! No blood test required, only a few drops of urine * By using the LPOKit to... |
 |
Advanced Protocols in Oxidative Stress I (Methods in Molecular Biology) by Donald Armstrong (Editor) Protocols books specializing in measuring free radical and antioxidant biomarkers began to be published in 1998. Many of these methods are currently finding use in diagnostic medicine. Advanced Protocols in Oxidative Stress I covers the field of oxidative stress with state-of-the-art technology to utilize in research, contributed by an international panel of experts renowned for developing new procedures and methods. Included are sections on reactive oxygen and nitrogen species techniques, antioxidant technology and application, methods for analyzing gene expression, the exciting new area of oxidative stress and stem cell differentiation and specific biostatistical evaluation of biomarkers. This volume presents the current high-tech methodologies and provides a perspective on... |
| © 2009 BrightSurf.com |