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

Penn biologists identify a key enzyme involved in protecting nerves from degeneration

2012-04-02
(Press-News.org) PHILADELPHIA –- A new animal model of nerve injury has brought to light a critical role of an enzyme called Nmnat in nerve fiber maintenance and neuroprotection. Understanding biological pathways involved in maintaining healthy nerves and clearing away damaged ones may offer scientists targets for drugs to mitigate neurodegenerative diseases such as Huntington's and Parkinson's, as well as aid in situations of acute nerve damage, such as spinal cord injury.

University of Pennsylvanian biologists developed the model in the adult fruit fly, Drosophila melanogaster.

"We are using the basic power of the fly to learn about how neurons are damaged in acute injury situations," said Nancy Bonini, senior author of the research and a professor in the Department of Biology at Penn. "Our work indicates that Nmnat may be key."

The research was published in Current Biology. First author on the study is postdoctoral researcher Yanshan Fang, with additional contributions from postdoctoral researcher Lorena Soares and research technicians Xiuyin Teng and Melissa Geary, all of Penn's Department of Biology.

When a nerve suffers an acute injury -- as might be caused by a penetrating wound, for example, or a broken bone that damages nearby tissues -- the long projection of the nerve cell, called the axon, can become injured and degenerate. The process by which it disintegrates is known as Wallerian or Wallerian-like degeneration and is an active, orderly process.

Though this function of eliminating damaged nerve cells is crucial, biologists do not have a clear understanding of all of the molecular signaling pathways that govern the process.

Bonini's lab has previously focused on chronic neurodegenerative diseases but made this foray into acute nerve injury to determine if mechanistic overlaps exist between acute axon injury and chronic neurodegeneration. They first searched for an appropriate nerve tract to target and identified the wing of adult flies as a prime option.

The fly wing is not only translucent and a site of lengthy nerve fibers that can be easily observed, but it can also be cut to cause injury without killing the fly. That way, the researchers can follow the animal's response to nerve injury for weeks.

Using various reagents to manipulate the fly's genetic traits, the team confirmed that the cut wing nerve underwent Wallerian degeneration. They then tested versions of Nmnat and another protein called WldS, all of which had previously been shown to protect nerves from degeneration, to see if any of these might stop the process. All significantly delayed neurodegeneration. Even a form of Nmnat that hadn't worked in other animal models suppressed degeneration, although to a lesser extent.

"That indicates that our assay is really sensitive," Bonini said. "This sensitivity could help us identify genes that have moderate although important functionality at protecting against nerve degeneration."

Their investigations into the wing nerve also showed that the degenerating axon "died back," fragmenting first from the axon terminals, the side farthest from the nerve cell body—a pattern similar to what has been seen in other disorders.

Doing more genetic tinkering, the researchers showed that when the animal's own Nmnat was depleted, the nerves fragmented in the same way as if the axon was physically cut. And when Nmnat and the other "rescue" proteins were added back to these genetically modified flies, they were able to block degeneration, highlighting that Nmnat is critical to maintaining healthy axons.

In a final set of experiments, the biologists sought to narrow where in the nerve cells Nmnat might be working. They focused on mitochondria, the powerhouses of cells. When they created a genetic line of flies that blocked mitochondria from entering the axon fibers, the nerve tract degenerated, again, in a dying-back fashion. Yet now WldS and Nmnat failed to prevent axon degeneration, suggesting that those proteins may act on and require the presence of axonal mitochondria to maintain healthy nerves in normal flies.

Flipping that scenario around, they looked to see what happened to the mitochondria of flies upon nerve injury. When they cut the wing nerve axons, the mitochondria rapidly disappeared. Yet they can largely preserve the mitochrondria by increasing expression of Nmnat.

Their results, taken together with the findings of other studies, suggest that Nmnat may stabilize mitochondria in some way in order to keep axons in a healthy state.

"We have some hope that these proteins or their activity may someday serve as drug targets or could provide the foundation for a therapeutic advance," Bonini said. "But right now, my hope is that the power of the fly model will open up a lot of new directions of research and new pathways that could be targets for development in the future."

INFORMATION:

This study was supported by the Howard Hughes Medical Institute, the Fidelity Foundation and the National Institutes of Health.

END



ELSE PRESS RELEASES FROM THIS DATE:

NIH study finds women spend longer in labor now than 50 years ago

2012-04-02
Women take longer to give birth today than did women 50 years ago, according to an analysis of nearly 140,000 deliveries conducted by researchers at the National Institutes of Health. The researchers could not identify all of the factors that accounted for the increase, but concluded that the change is likely due to changes in delivery room practice. The study authors called for further research to determine whether modern delivery practices are contributing to the increase in labor duration. The researchers compared data on deliveries in the early 1960s to data gathered ...

Preventing home invasions means fighting side-by-side for coral-dwelling crabs and shrimp

Preventing home invasions means fighting side-by-side for coral-dwelling crabs and shrimp
2012-04-02
As any comic book lover knows, when superheroes band together the bad guys fall harder. The strength that comes in numbers is greater than the sum of its parts. The same holds true, researchers have recently learned, when different species of crabs (genus Trapezia) and snapping shrimp (Alepheus lottini) in the central Pacific band together to defend their coral homes from hungry seastars. In these frequent conflicts "one-plus-one doesn't always equal two, sometime it is more," explains Seabird McKeon, a marine biologist at the National Museum of Natural History's Smithsonian ...

Study supports using virtual environment to teach mind/body techniques

2012-04-02
A small study from Massachusetts General Hospital (MGH) researchers found that online virtual communities may be an effective way to train patients in meditation and other mind/body techniques. The ability to learn and practice approaches that elicit the relaxation response – a state of deep rest that has been shown to alleviate stress-related symptoms – in a virtual environment could help surmount several barriers that can restrict participation. "Our finding that a medical intervention – in this case teaching a mind/body approach that includes the relaxation response ...

NASA sees Typhoon Pakhar headed for Vietnam landfall

NASA sees Typhoon Pakhar headed for Vietnam landfall
2012-04-02
The first typhoon of the northern hemisphere 2012 typhoon season is headed for landfall in Vietnam. NASA's Aqua and TRMM satellites have been providing forecasters with valuable data on Typhoon Pakhar, that includes rainfall rates, cloud extent and temperature. The Tropical Rainfall Measuring Mission (TRMM) satellite flew almost directly over Pakhar when it was a newly formed tropical storm in the South China Sea on March 29, 2012 at 1122 UTC/4:22 p.m. Asia local time (or 7:22 a.m. EDT). The intensifying storm had wind speeds of about 45 knots (~52 mph/~83 kph) and was ...

Images capture split personality of dense suspensions

Images capture split personality of dense suspensions
2012-04-02
Stir lots of small particles into water, and the resulting thick mixture appears highly viscous. When this dense suspension slips through a nozzle and forms a droplet, however, its behavior momentarily reveals a decidedly non-viscous side. University of Chicago physicists recorded this surprising behavior in laboratory experiments using high-speed photography that can capture action taking place in one hundred-thousandths of a second or less. UChicago graduate student Marc Miskin and Heinrich Jaeger, the William J. Friedman and Alicia Townsend Friedman Professor in Physics, ...

Tokai Pharmaceuticals' galeterone well-tolerated in patients with advanced prostate cancer

2012-04-02
CAMBRIDGE, Mass. and CHICAGO, Ill. -- Tokai Pharmaceuticals, Inc., a biopharmaceutical company focused on developing new treatments for prostate cancer, today announced that its lead candidate galeterone (TOK-001) was well-tolerated with minimal side effects and demonstrated efficacy in patients with castration-resistant prostate cancer (CRPC) in a Phase 1 study. The data will be presented in an oral presentation titled, "ARMOR1: Safety of galeterone (TOK-001) in a Phase 1 clinical trial in chemotherapy naïve patients with castration-resistant prostate cancer (CRPC)," abstract ...

Early clinical data show galeterone safe, effective against prostate cancer

2012-04-02
CHICAGO — Patients with castration-resistant prostate cancer had limited side effects and in many cases a drop in prostate-specific antigen expression with galeterone (TOK-001), a small-molecule oral drug, according to phase I data presented at the AACR Annual Meeting 2012, held here March 31 - April 4. Castration-resistant prostate cancer (CRPC) is an advanced form of prostate cancer that occurs when the disease progresses after treatment with androgen deprivation therapy. Galeterone works against CRPC by blocking the androgen receptor, reducing levels of the ligand ...

Metformin appeared to slow prostate cancer growth

2012-04-02
CHICAGO — The use of metformin in men with prostate cancer before prostatectomy helped to reduce certain metabolic parameters and slow the growth rate of the cancer, according to the results of a phase II study. Anthony M. Joshua, M.B.B.S., Ph.D., staff medical oncologist at the Princess Margaret Hospital, University Health Network in Toronto, Ontario, Canada, presented the data at the AACR Annual Meeting 2012, held here March 31 - April 4. Metformin is the most commonly prescribed medication for diabetes. Prior laboratory research has suggested that metformin may ...

Biomarker identified in relation to drug response in refractory urothelial cancer

2012-04-02
CHICAGO — The antiangiogenic drug pazopanib has demonstrated clinically meaningful activity in patients with refractory urothelial cancer, according to results presented at the AACR Annual Meeting 2012, held here March 31 - April 4. The results also revealed that increases in interleukin-8 levels early after treatment with pazopanib may predict a lack of tumor response to the therapy. "Historically, prognosis of patients with relapsed or refractory urothelial cancer is quite dismal," said Andrea Necchi, M.D., faculty member in the department of medicine at Fondazione ...

Towards TB elimination: ECDC and ERS introduce new guidelines on tuberculosis care in Europe

2012-04-02
Today, the European Respiratory Society (ERS) and the European Centre for Disease Prevention and Control (ECDC) publish their jointly developed European Union Standards for Tuberculosis Care (ESTC). The 21 patient-centred standards aim to guide clinicians and public health workers to ensure optimal diagnosis, treatment and prevention of tuberculosis (TB) in Europe – with nearly 74,000 reported TB cases in the EU/EEA in 2010 clearly showing that TB remains a public health challenge across the region. The new EU-specific guidelines were developed by a panel of 30 experts ...

LAST 30 PRESS RELEASES:

Exercise as an anti-ageing intervention to avoid detrimental impact of mental fatigue

UMass Amherst Nursing Professor Emerita honored as ‘Living Legend’

New guidelines aim to improve cystic fibrosis screening

Picky eaters by day, buffet by night: Butterfly, moth diets sync to plant aromas

Pennington Biomedical’s Dr. Leanne Redman honored with the E. V. McCollum Award from the American Society for Nutrition

CCNY physicists uncover electronic interactions mediated via spin waves

Researchers’ 3D-printing formula may transform future of foam

Nurture more important than nature for robotic hand

Drug-delivering aptamers target leukemia stem cells for one-two knockout punch

New study finds that over 95% of sponsored influencer posts on Twitter were not disclosed

New sea grant report helps great lakes fish farmers navigate aquaculture regulations

Strain “trick” improves perovskite solar cells’ efficiency

How GPS helps older drivers stay on the roads

Estrogen and progesterone stimulate the body to make opioids

Dancing with the cells – how acoustically levitating a diamond led to a breakthrough in biotech automation

Machine learning helps construct an evolutionary timeline of bacteria

Cellular regulator of mRNA vaccine revealed... offering new therapeutic options

Animal behavioral diversity at risk in the face of declining biodiversity

Finding their way: GPS ignites independence in older adult drivers

Antibiotic resistance among key bacterial species plateaus over time

‘Some insects are declining but what’s happening to the other 99%?’

Powerful new software platform could reshape biomedical research by making data analysis more accessible

Revealing capillaries and cells in living organs with ultrasound

American College of Physicians awards $260,000 in grants to address equity challenges in obesity care

Researchers from MARE ULisboa discover that the European catfish, an invasive species in Portugal, has a prolonged breeding season, enhancing its invasive potential

Rakesh K. Jain, PhD, FAACR, honored with the 2025 AACR Award for Lifetime Achievement in Cancer Research

Solar cells made of moon dust could power future space exploration

Deporting immigrants may further shrink the health care workforce

Border region emergency medical services in migrant emergency care

Resident physician intentions regarding unionization

[Press-News.org] Penn biologists identify a key enzyme involved in protecting nerves from degeneration