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

Cell death pathway linked to mitochondrial fusion

2011-01-26
(Press-News.org) New research led by UC Davis scientists provides insight into why some body organs are more susceptible to cell death than others and could eventually lead to advances in treating or preventing heart attack or stroke.

In a paper published Jan. 21 in the journal Molecular Cell, the UC Davis team and their collaborators at the National Institutes of Health and Johns Hopkins University report that Bax, a factor known to promote cell death, is also involved in regulating the behavior of mitochondria, the structures that provide energy inside living cells.

Mitochondria constantly split and fuse. The proteins that control the splitting of mitochondria also promote a process called apoptosis, or programmed cell death. In contrast, the proteins that control mitochondrial fusion help protect against cell death. Cell death can happen when cells are starved of oxygen, for example during a heart attack or stroke.

Yeast have a single protein that controls outer membrane fusion, but both human and mouse cells have two proteins, called MFN1 and MFN2, which control outer membrane fusion. Using mitochondria from cells derived from genetically modified "knockout" mice, Suzanne Hoppins, a postdoctoral researcher at UC Davis, and Jodi Nunnari, a professor of molecular cell biology, studied how these two proteins work together and the role specific genes play in that process.

The research team discovered that these proteins combine with themselves or each other to form a tether between two mitochondria, leading to fusion. All three combinations -- MFN1/MFN1, MFN1/MFN2 and MFN2/MFN2 -- can promote membrane fusion, but the combination of MFN1/MFN2 is by far the most efficient, Hoppins said.

Hoppins also found that a soluble form of Bax, a protein that triggers apoptosis, can also stimulate mitochondria to fuse. It acts only through the MFN2/MFN2 combination, she found.

The form of Bax that promotes mitochondrial fusion is different from the type that leads to cell death, Nunnari said. Bax leads to cell death when it inserts itself in the mitochondrial membrane. In its soluble, free-floating form, it causes mitochondria to fuse instead.

MFN1 and MFN2 are found in different amounts in different body organs. MFN2 is more abundant in the brain and heart -- tissues where cell death can have disastrous consequences.

The paper shows how MFN2 could act to protect the brain or heart from cell death, by using Bax in a different form, Nunnari said.

"This shows that the fusion machine is both positively and negatively regulated in cells and opens doors to finding the regulatory mechanisms and discovering ways to increase or decrease the sensitivity of cells to apoptosis," Hoppins said. That could lead to new drugs that save cells, for heart disease and stroke, or that kill cells, for cancer.

INFORMATION:

Co-authors of the study are UC Davis graduate student Megan Cleland; UC Davis postdoctoral researchers Frank Edlich and Soojay Banerjee; and Richard Youle, a senior investigator at the National Institute for Neurological Disorders and Stroke; and J. Michael McCaffery, a professor at Johns Hopkins University.

The research was supported by grants from the National Institutes of Health. Hoppins recently received a K99 "Young Investigator" award from the NIH.

END



ELSE PRESS RELEASES FROM THIS DATE:

Wheat resistance genes failing, new approach needed to stop flies

Wheat resistance genes failing, new approach needed to stop flies
2011-01-26
WEST LAFAYETTE, Ind. - Many of the genes that allow wheat to ward off Hessian flies are no longer effective in the southeastern United States, and care should be taken to ensure that resistance genes that so far haven't been utilized in commercial wheat lines are used prudently, according to U.S. Department of Agriculture and Purdue University scientists. An analysis of wheat lines carrying resistance genes from dozens of locations throughout the Southeast showed that some give little or no resistance to the Hessian fly, a major pest of wheat that can cause millions of ...

Conversion of brain tumor cells into blood vessels thwarts treatment efforts

Conversion of brain tumor cells into blood vessels thwarts treatment efforts
2011-01-26
LA JOLLA, CA--Glioblastoma, the most common and lethal form of brain cancer and the disease that killed Massachusetts Senator Ted Kennedy, resists nearly all treatment efforts, even when attacked simultaneously on several fronts. One explanation can be found in the tumor cells' unexpected flexibility, discovered researchers at the Salk Institute for Biological Studies. When faced with a life-threatening oxygen shortage, glioblastoma cells can shift gears and morph into blood vessels to ensure the continued supply of nutrients, reports a team led by Inder Verma, Ph.D., ...

Purdue team creates 'engineered organ' model for breast cancer research

Purdue team creates engineered organ model for breast cancer research
2011-01-26
WEST LAFAYETTE, Ind. - Purdue University researchers have reproduced portions of the female breast in a tiny slide-sized model dubbed "breast on-a-chip" that will be used to test nanomedical approaches for the detection and treatment of breast cancer. The model mimics the branching mammary duct system, where most breast cancers begin, and will serve as an "engineered organ" to study the use of nanoparticles to detect and target tumor cells within the ducts. Sophie Lelièvre, associate professor of basic medical sciences in the School of Veterinary Medicine, and ...

Blue crab research may help Chesapeake Bay watermen improve soft shell harvest

2011-01-26
Baltimore, Md. (January 24, 2011) – A research effort designed to prevent the introduction of viruses to blue crabs in a research hatchery could end up helping Chesapeake Bay watermen improve their bottom line by reducing the number of soft shell crabs perishing before reaching the market. The findings, published in the journal Diseases of Aquatic Organisms, shows that the transmission of a crab-specific virus in diseased and dying crabs likely occurs after the pre-molt (or 'peeler') crabs are removed from the wild and placed in soft-shell production facilities. Crab ...

Loyola physician helps develop national guidelines for osteoporosis

2011-01-26
MAYWOOD, Ill. -- The American Association of Clinical Endocrinologists (AACE) has released new medical guidelines for the diagnosis and treatment of postmenopausal osteoporosis. Loyola physician Pauline Camacho, MD, was part of a committee that developed the guidelines to manage this major public health issue. These recommendations were developed to reduce the risk of osteoporosis-related fractures and improve the quality of life for patients. They explain new treatment options and suggest the use of the FRAX tool (a fracture risk assessment tool developed by the World ...

GRIN plasmonics

GRIN plasmonics
2011-01-26
They said it could be done and now they've done it. What's more, they did it with a GRIN. A team of researchers with the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California, Berkeley, have carried out the first experimental demonstration of GRIN – for gradient index – plasmonics, a hybrid technology that opens the door to a wide range of exotic optics, including superfast computers based on light rather than electronic signals, ultra-powerful optical microscopes able to resolve DNA molecules with visible ...

Women in Congress outperform men on some measures

2011-01-26
Congresswomen consistently outperform their male counterparts on several measures of job performance, according to a recent study by University of Chicago scholar Christopher Berry. The research comes as the 112th Congress is sworn in this month with 89 women, the first decline in female representation since 1978. The study authors argue that because women face difficult odds in reaching Congress – women account for fewer than one in six representatives – the ones who succeed are more capable on average than their male colleagues. Women in Congress deliver more federal ...

Legal restrictions compromise effectiveness of advance directives

2011-01-26
Current legal restrictions significantly compromise the clinical effectiveness of advance directives, according to a study by researchers at the University of California, San Francisco. Advance directives allow patients to designate health care decision-makers and specify health care preferences for future medical needs. However, "the legal requirements and restrictions necessary to execute a legally valid directive prohibit many individuals from effectively documenting their end-of-life wishes," said lead author Lesley S. Castillo, BA, a geriatrics research assistant ...

Neurologists predict more cases of stroke, dementia, Parkinson's disease and epilepsy

2011-01-26
MAYWOOD, Ill. -- As the population ages, neurologists will be challenged by a growing population of patients with stroke, dementia, Parkinson's disease and epilepsy. The expected increase in these and other age-related neurologic disorders is among the trends that Loyola University Health System neurologists Dr. José Biller and Dr. Michael J. Schneck describe in a January, 2011, article in the journal Frontiers in Neurology. In the past, treatment options were limited for patients with neurological disorders. "Colloquially, the neurologist would 'diagnose and adios,'" ...

Preschool kids know what they like: Salt, sugar and fat

Preschool kids know what they like: Salt, sugar and fat
2011-01-26
EUGENE, Ore. -- (Jan. 25, 2011) -- A child's taste preferences begin at home and most often involve salt, sugar and fat. And, researchers say, young kids learn quickly what brands deliver the goods. In a study of preschoolers ages 3 to 5, involving two separate experiments, researchers found that salt, sugar and fat are what kids most prefer -- and that these children already could equate their taste preferences to brand-name fast-food and soda products. In a world where salt, sugar and fat have been repeatedly linked to obesity, waiting for children to begin school ...

LAST 30 PRESS RELEASES:

Elena Belova and Yevgeny Raitses recognized for groundbreaking plasma physics research

SOX9 overexpression ameliorates metabolic dysfunction-associated steatohepatitis through activation of the AMPK pathway

Florescent probes illuminate cholesterol and Alzheimer’s research

Qigong significantly decreases chronic low back pain in US military veterans

New insights into pancreatic disease and diabetes

Effectiveness and safety of tenofovir amibufenamide in the treatment of chronic hepatitis B: A real-world, multicenter study

Higher costs limit attendance for life changing cardiac rehab

Over 500 patients receive diagnosis through genetic reanalysis

Brain changes in Huntington’s disease decades before diagnosis will guide future prevention trials

U of A astronomers capture unprecedented view of supermassive black hole in action

Astrophysicists reveal structure of 74 exocomet belts orbiting nearby stars in landmark survey

Textbooks need to be rewritten: RNA, not DNA, is the main cause of acute sunburn

Brits still associate working-class accents with criminal behavior – study warns of bias in the criminal justice system

What do you think ‘guilty’ sounds like? Scientists find accent stereotypes influence beliefs about who commits crimes

University of Calgary nursing study envisions child trauma treatment through a Marvel and DC lens

Research on performance optimization of virtual data space across WAN

Researchers reveal novel mechanism for intrinsic regulation of sugar cravings

Immunological face of megakaryocytes

Calorie labelling leads to modest reductions in selection and consumption

The effectiveness of intradialytic parenteral nutrition with ENEFLUID???? infusion

New study reveals AI’s transformative impact on ICU care with smarter predictions and transparent insights

Snakes in potted olive trees ‘tip of the iceberg’ of ornamental plant trade hazards

Climate change driving ‘cost-of-living' squeeze in lizards

Stem Cell Reports seeks applications for its Early Career Scientist Editorial Board

‘Brand new physics’ for next generation spintronics

Pacific Islander teens assert identity through language

White House honors Tufts economist

Sharp drop in mortality after 41 weeks of pregnancy

Flexible electronics integrated with paper-thin structure for use in space

Immune complex shaves stem cells to protect against cancer

[Press-News.org] Cell death pathway linked to mitochondrial fusion