Science Current Events | Science News | Brightsurf.com
 

Scientists identify major source of cells' defense against oxidative stress

April 09, 2012
Research on how cells cope with stress could lead to more effective ways to weaken and kill cancer cells

Both radiation and many forms of chemotherapy try to kill tumors by causing oxidative stress in cancer cells. New research from USC on a protein that protects cancer and other cells from these stresses could one day help doctors to break down cancer cells' defenses, making them more susceptible to treatment.

In the March 23 issue of the Journal of Biological Chemistry, scientists led by USC Professor Kelvin J. A. Davies demonstrated that a protein known as Nrf2 governs a cell's ability to cope with oxidative stress by increasing the expression of key genes for removing damaged proteins.

Typically, oxidative stress is to be avoided. People eat foods high in antioxidants (such as fruits and vegetables) to try to block oxidation in their cells, in hopes of lowering their risk of illnesses such as cancer, heart disease, stroke and Alzheimer disease - which are all linked to oxidative stress.

But in the case of cancer cells, if the Nrf2 response could some day be selectively turned off, treatments like chemotherapy and radiation could be more effective, Davies said.

"One of the problems you have is that cancer cells start becoming resistant to those treatments: they adapt," said Davies, who holds joint appointments in the USC Davis School of Gerontology the USC Dornsife College of Letters, Arts and Sciences. "The next time they may be more resistant because they've seen it before."

Nrf2 is a transcription factor protein, meaning that it binds to specific sequences of DNA, turning on the process of copying the blueprints encoded in those DNA sequences into functional enzymes. In particular, the new work from the Davies lab shows that production of proteasome and a proteasome regulator (Pa28) is controlled by Nrf2 during oxidative stress. Proteosome, in turn, is a large protein enzyme that breaks down oxidized proteins that would otherwise accumulate and cause cells to die.

When oxidative stress increases (simulated in the lab by adding hydrogen peroxide - the major product of both radiation therapy and chemotherapy), Davies and his team found that the Nrf2 in a cell starts ramping up proteasome production.

The researchers then tested their findings by blocking Nrf2 with various chemical and genetic inhibitors, which in turn decreased the cell's ability to make more proteasome and cope with the hydrogen peroxide.

In normal young cells, Nrf2 allows continuous regulation of proteasome production in response to changing oxidative environments. This ability may decline in aging and age-related diseases, making older individuals less able to cope with stress.

"We would like to be able to reverse this decline in normal cells, while making cancer cells less stress-resistant and more easily killed by radiation therapy and chemotherapy," Davies said.

University of Southern California


Related Oxidative Stress Current Events and Oxidative Stress News Articles


Investigational anti-diabetic may offer potential for management of non-alcoholic fatty liver
Data presented today at The International Liver Congress™ 2015 demonstrates that remogliflozin etabonate, an investigational drug in type 2 diabetes, is a potential treatment option for the management of patients with non-alcoholic steatohepatitis (NASH) and non-alcoholic fatty liver disease (NAFLD).

Dwindling bird populations in Fukushima
This is the time of year when birds come out and really spread their wings, but since a disastrous day just before spring's arrival four years ago, Japan's Fukushima province has not been friendly to the feathered.

Study shows novel pattern of electrical charge movement through DNA
Electrical charges not only move through wires, they also travel along lengths of DNA, the molecule of life. The property is known as charge transport.

Intrauterine exposure to maternal gestational diabetes linked with risk of autism
Among a group of more than 320,000 children, intrauterine exposure to gestational diabetes mellitus diagnosed by 26 weeks' gestation was associated with risk of autism spectrum disorders (ASDs).

Ancient herbal therapy can prevent -- and reverse -- cardiac hypertrophy in mice
A natural compound derived from the bark of the magnolia tree, can protect the heart from hypertrophy, a thickening of cardiac muscle often caused by chronic high blood pressure that can lead to heart failure, researchers report in the April 14 issue of the online journal Nature Communications.

Selenide protects heart muscle in the wake of cardiac arrest
Damage to heart muscle from insufficient blood supply during cardiac arrest and reperfusion injury after blood flow is restored can be reduced by nearly 90 percent if selenide, a form of the essential nutrient selenium, is administered intravenously in the wake of the attack.

U-M researchers track the toxicity of Lake Erie cyanobacterial blooms
Efforts to reduce the amount of phosphorus and other nutrients washing off farm fields and into Lake Erie shifted into overdrive after high levels of a bacterial toxin shut down the drinking water supply to more than 400,000 Toledo-area residents last August.

Ironing out oxidative stress
You're up in the mountains, the snow is blindingly white, and the sun is blazing down from the sky: ideal skiing conditions - but any skiers carrying the herpes virus might also have to reckon with the onset of cold sores after their day out.

No evidence that low-frequency magnetic fields accelerate development of Alzheimer's, ALS
Low-frequency alternating magnetic fields such as those generated by overhead power lines are considered a potential health risk because epidemiological studies indicate that they may aggravate, among other things, neurodegenerative disorders such as Alzheimer's disease and amyotrophic lateral sclerosis (ALS).

Researchers uncover a mechanism linking inhaled diesel pollution and respiratory distress
Estoril, Portugal: Researchers in the UK have, for the first time, shown how exhaust pollution from diesel engines is able to affect nerves within the lung.
More Oxidative Stress Current Events and Oxidative Stress News Articles

Molecular Basis of Oxidative Stress: Chemistry, Mechanisms, and Disease Pathogenesis

Molecular Basis of Oxidative Stress: Chemistry, Mechanisms, and Disease Pathogenesis
by Frederick A. Villamena (Author)


Sets the stage for the development of better diagnostic techniques and therapeutics Featuring contributions from an international team of leading clinicians and biomedical researchers, Molecular Basis of Oxidative Stress reviews the molecular and chemical bases of oxidative stress, describing how oxidative stress can lead to the development of cancer and cardiovascular and neurodegenerative diseases. Moreover, it explains the potential role of free radicals in both the diagnosis and the development of therapeutics to treat disease. Molecular Basis of Oxidative Stress is logically organized, beginning with a comprehensive discussion of the fundamental chemistry of reactive species. Next, the book: Presents new mechanistic insights into how oxidative damage of biomolecules occurs Examines...

Oxidative Stress: What is Oxidative Stress?

Oxidative Stress: What is Oxidative Stress?
by Matthew Jordan (Author)


The term oxidative stress has been linked to multiple diseases and aging. Oxidative stress and managing free radicals through antioxidants has also become big business and it is important that consumers educate themselves on effective oxidative stress management. This book will provide a simple definition of oxidative stress along with sources of oxidative stress management.

Role of Oxidative Stress in Chronic Diseases

Role of Oxidative Stress in Chronic Diseases
by Isaias Dichi (Editor), José Wander Breganó (Editor), Andréa Name Colado Simão (Editor), Rubens Cecchini (Editor)


This book presents recent findings on the role of oxidative stress in chronic diseases. Understanding the mechanisms behind it enables readers to comprehend the rationale which underlies intervention in such conditions. The book places special emphasis on genetic polymorphism—an important issue related to this field of study. It covers the role of oxidative stress in transmissible disorders as well as non-transmissible chronic conditions with chapters on metabolic diseases, autoimmune and neurodegenerative diseases, and cancer and cachexia. Each chapter covers a different disorder and the efficacy of interventional procedures.

Secrets from the Eating Lab: The Science of Weight Loss, the Myth of Willpower, and Why You Should Never Diet Again

Secrets from the Eating Lab: The Science of Weight Loss, the Myth of Willpower, and Why You Should Never Diet Again
by Traci Mann (Author)


A provocative expose of the dieting industry from one of the nation’s leading researchers in self-control and the psychology of weight loss that offers proven strategies for sustainable weight loss.From her office in the University of Minnesota’s Health and Eating Lab, professor Traci Mann researches self-control and dieting. And what she has discovered is groundbreaking. Not only do diets not work; they often result in weight gain. Americans are losing the battle of the bulge because our bodies and brains are not hardwired to resist food—the very idea of it works against our biological imperative to survive.In Secrets From the Eating Lab, Mann challenges assumptions—including those that make up the very foundation of the weight loss industry—about how diets work and why they...

Adrenal Fatigue: The 21st Century Stress Syndrome

Adrenal Fatigue: The 21st Century Stress Syndrome
by James Wilson (Author), Jonathan V Wright (Foreword)


This is an incredibly informative and reader-friendly book about a common debilitating medical condition that goes largely undiagnosed and untreated. ADRENAL FATIGUE: The 21st Century Stress Syndrome is a very empowering work cram-packed with vital information about a condition that very likely affects millions of people.

Free Radicals in Biology and Medicine

Free Radicals in Biology and Medicine
by Barry Halliwell (Author), John Gutteridge (Author)


Free Radicals in Biology and Medicine has become a classic text in the field of free radical and antioxidant research since its first publication in 1985.

This latest edition has been comprehensively rewritten and updated (over 80% of the text is new), while maintaining the clarity of its predecessor. There is expanded coverage of isoprostanes and related compounds, mechanisms of oxidative damage to DNA and proteins (and the repair of such damage), the free radical theory of aging and the roles played by reactive species in signal transduction, cell death, human reproduction, and other important biological events. Greater emphasis has also been placed on the methods available to measure reactive species and oxidative damage (and their potential pitfalls), as well as the importance...

Oxidative Stress and Hormesis in Evolutionary Ecology and Physiology: A Marriage Between Mechanistic and Evolutionary Approaches

Oxidative Stress and Hormesis in Evolutionary Ecology and Physiology: A Marriage Between Mechanistic and Evolutionary Approaches
by David Costantini (Author)


This book discusses oxidative stress and hormesis from the perspective of an evolutionary ecologist or physiologist. In the first of ten chapters, general historical information, definitions, and background of research on oxidative stress physiology, hormesis, and life history are provided. Chapters 2-10 highlight the different solutions that organisms have evolved to cope with the oxidative threats posed by their environments and lifestyles. The author illustrates how oxidative stress and hormesis have shaped diversity in organism life-histories, behavioral profiles, morphological phenotypes, and aging mechanisms. The book offers fascinating insights into how organisms work and how they evolve to sustain their physiological functions under a vast array of environmental conditions.

What Doesn't Kill Us, Makes Us Stronger: Reducing Oxidative Stress and Damage Through Adaptive Stress Responses (Human Anatomy and Physiology)

What Doesn't Kill Us, Makes Us Stronger: Reducing Oxidative Stress and Damage Through Adaptive Stress Responses (Human Anatomy and Physiology)
by Borut Poljsak (Author), Irina Milisav (Author)




TOX-SICK: From Toxic to Not Sick

TOX-SICK: From Toxic to Not Sick
by Suzanne Somers (Author)


“It’s as if we are all on a big, chemical drunk, and the hangover is a killer.”
—Suzanne Somers, in TOX-SICK

Pioneering health and wellness advocate, Suzanne Somers, delivers a powerful answer in this expose on the immediate and long-term dangers of living in a world that has become increasingly toxic to our health.  The build-up of toxins in our bodies can lead to myriad health concerns — including weight gain, food allergies, brain disorders, cancer, among many others. Moved to investigate by her own family’s plight, Suzanne sits down with environmental doctors and specialists who share eye-opening information and practical advice for how to survive, thrive, and stay healthy today. In Tox-Sick you’ll learn how to effectively detox all your body’s systems and...

Oxidative Stress and Inflammatory Mechanisms in Obesity, Diabetes, and the Metabolic Syndrome (Oxidative Stress and Disease)

Oxidative Stress and Inflammatory Mechanisms in Obesity, Diabetes, and the Metabolic Syndrome (Oxidative Stress and Disease)
by Helmut Sies (Editor)


Characterized by obesity, insulin resistance, dyslipidemia, and hypertension, metabolic syndrome is associated with the risks of type 2 diabetes mellitus and cardiovascular disease. Obesity, which increases the incidence of atherosclerotic cardiovascular disease and subsequently leads to increased stress and inflammation, appears to play a central role in the progression of the syndrome. Evidence of inflammatory processes in accumulated fat appears to be an early initiator of metabolic syndrome. Likewise, the more active angiotensin system in obesity may contribute to even greater oxidative stress that serves as a key signaling event in vascular remodeling. These factors strengthen obesity's association with oxidative stress.

Oxidative Stress and Inflammatory Mechanisms in Obesity,...

© 2015 BrightSurf.com