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

Live and let-7: MicroRNA plays surprising role in cell survival

Live and let-7: MicroRNA plays surprising role in cell survival
2014-10-07
(Press-News.org) Researchers at the University of California, San Diego School of Medicine have identified a microRNA molecule as a surprisingly crucial player in managing cell survival and growth. The findings, published in the October 7 issue of Cell Metabolism, underscore the emerging recognition that non-coding RNAs – small molecules that are not translated into working proteins – help regulate basic cellular processes and may be key to developing new drugs and therapies.

Specifically, principal investigator Albert R. La Spada, MD, PhD, professor of cellular and molecular medicine, chief of the Division of Genetics in the Department of Pediatrics and associate director of the Institute for Genomic Medicine at UC San Diego, and colleagues found that a microRNA known as let-7 controls autophagy through the amino acid sensing pathway, which has emerged as the most potent activator of mTORC1 complex activity.

Autophagy is a fundamental process used by cells to degrade unnecessary components in times of starvation, releasing energy stores that help promote cell survival. Cells have further adapted autophagy for other purposes as well, including recycling dysfunctional components, immune response to pathogen invasion, surveillance against cancer and maintenance of protein and organelle control in the central nervous system. MTORC1 is a critical protein complex that regulates energy consumption and growth in cells.

"The ability of let-7 alone to activate autophagy in this way was totally unknown and is very surprising," said La Spada. "As let-7 is known to be a tumor suppressor, its ability to activate autophagy could be a major component of its anti-tumor forming activity," though La Spada noted that autophagy may also contrarily promote tumor progression by supporting the altered metabolism of growing cancers.

With let-7 revealed to be a master regulator of metabolism, helping to modulate anabolic growth (the creation of new molecules in cells) with catabolic destruction (the breakdown of molecules in cells), researchers say the overall picture of how cells function becomes more fine-tuned but also more complicated.

"The fact that let-7 is opposing the action of the amino acid sensing pathway provides a glimpse into the complex pathway regulation at work in the cell, with microRNAs emerging as important factors for cells to maintain metabolic set points and overall homeostasis or a healthy equilibrium."

The therapeutic potential of let-7 remains to be explored. La Spada said he and colleagues have shown that a lentivirus encoding let-7 injected into mouse neurons promotes the autophagic turnover of toxic misfolded proteins associated with neurodegenerative disease.

"We also demonstrate that treatment with anti-let-7 can block autophagy and that this has physiological consequences (weight gain) in mice. It is possible that modulation of let-7 could be pursued for therapeutic application using very carefully targeted delivery systems, but further work will be necessary to see if this is practically possible."

INFORMATION:

Co-authors include Amy N. Dubinsky, Somasish Ghosh Dasidar, Cynthia L. Hsu, Rabaab Zahra, Steven Djakovic, Travis D. Ashe and Bradley E. Morrison, UCSD Department of Pediatrics; Sonia Duarte, Kimberlee M. Fischer and Luis Pereira de Almeida, University of Coimbra, Portugal; Christine C. Esau, Deidre A. MacKenna and B. Nelson Chau, Regulus Therapeutics; Brian Spencer and Eliezer Masliah, UCSD Department of Neurosciences; Bryce L. Sopher, University of Washington; and Terry Gaasterland, Scripps Institute for Oceanography and UCSD Institute for Genomic Medicine.

Funding support came, in part, from the National Institutes of Health (grants R01 AG03382, R01 EY014997, T32 AG000216, T32 GM008666 and P30 HD002274) and the Portuguese Foundation for Science and Technology.


[Attachments] See images for this press release:
Live and let-7: MicroRNA plays surprising role in cell survival

ELSE PRESS RELEASES FROM THIS DATE:

This week From AGU: Avalanche detection, paleoclimate reconstructions, India's Tapti Fault

This week From AGU: Avalanche detection, paleoclimate reconstructions, Indias Tapti Fault
2014-10-07
From AGU's blogs: Detecting avalanches from sounds we can't hear http://blogs.agu.org/geospace/2014/10/07/detecting-avalanches-sounds-cant-hear/ Researchers have developed a new avalanche monitoring method that uses sound below the range of human hearing to detect and track these deadly and destructive snow slides. The technique can detect an avalanche from the moment it starts, picking up the unheard thump of a rupture in the snowpack that can precede the snow cascade. It can then track the avalanche's path second by second down the mountain. In a new study published ...

Toddlers regulate behavior to avoid making adults angry

2014-10-07
When kids say "the darnedest things," it's often in response to something they heard or saw. This sponge-like learning starts at birth, as infants begin to decipher the social world surrounding them long before they can speak. Now researchers at the University of Washington have found that children as young as 15 months can detect anger when watching other people's social interactions and then use that emotional information to guide their own behavior. The study, published in the October/November issue of the journal, Cognitive Development, is the first evidence that ...

New 'lab-on-a-chip' could revolutionize early diagnosis of cancer

New lab-on-a-chip could revolutionize early diagnosis of cancer
2014-10-07
LAWRENCE — Scientists have been laboring to detect cancer and a host of other diseases in people using promising new biomarkers called "exosomes." Indeed, Popular Science magazine named exosome-based cancer diagnostics one of the 20 breakthroughs that will shape the world this year. Exosomes could lead to less invasive, earlier detection of cancer, and sharply boost patients' odds of survival. "Exosomes are minuscule membrane vesicles — or sacs — released from most, if not all, cell types, including cancer cells," said Yong Zeng, assistant professor ...

Study: Even motivated dieters need close access to healthy food

2014-10-07
You're obese, at risk for diabetes and cardiovascular disease, and so motivated to improve your diet that you've enrolled in an intensive behavioral program. But if you need to travel more than a short distance to a store that offers a good selection of healthy food, your success may be limited. A new study from UMass Medical School and the Massachusetts Department of Public Health finds that not having close access to healthy foods can deter even the most motivated dieters from improving their diet, suggesting that easy access to healthy food is as important as personal ...

Around the world in 400,000 years: The journey of the red fox

Around the world in 400,000 years: The journey of the red fox
2014-10-07
Imagine attempting to trace your genetic history using only information from your mother's side. That's what scientists studying the evolution of the red fox had been doing for decades. Now, University of California, Davis, researchers have for the first time investigated ancestry across the red fox genome, including the Y chromosome, or paternal line. The data, compiled for over 1,000 individuals from all over the world, expose some surprises about the origins, journey and evolution of the red fox, the world's most widely distributed land carnivore. "The genome and ...

NASA eyes Super typhoon Vongfong

NASA eyes Super typhoon Vongfong
2014-10-07
Typhoon Vongfong strengthened into a Super typhoon on Tuesday, October 7 as NASA's Aqua satellite passed overhead. On Oct. 7 at 0429 UTC (12:29 a.m. EDT) the Atmospheric Infrared Sounder called AIRS that flies aboard NASA's Aqua satellite captured cloud top temperature data on Super typhoon Vongfong. AIRS data very strong thunderstorms circling Vongfong's clear 27 nautical-mile wide eye. Those cloud top temperatures were colder than -62F/-53C indicating that they were high in the troposphere and capable of generating heavy rainfall. The bands of thunderstorms circling ...

Very low concentrations of heavy metals and antibiotics contribute to resistance

2014-10-07
New Swedish research shows that plasmids containing genes that confer resistance to antibiotics can be enriched by very low concentrations of antibiotics and heavy metals. These results strengthen the suspicion that the antibiotic residues and heavy metals (such as arsenic, silver and copper) that are spread in the environment are contributing to the problems of resistance. These findings have now been published in the highly regarded journal mBio. Antibiotic resistance is a growing medical problem that threatens human health worldwide. Why and how these resistant bacteria ...

Efficacy of potential therapy for autoimmune disorder of muscle weakness

Efficacy of potential therapy for autoimmune disorder of muscle weakness
2014-10-07
PHILADELPHIA — Nearly 60,000 Americans suffer from myasthenia gravis (MG), a non-inherited autoimmune form of muscle weakness. The disease has no cure, and the primary treatments are nonspecific immunosuppressants and inhibitors of the enzyme cholinesterase. Now, a pair of researchers from the Perelman School of Medicine at the University of Pennsylvania have developed a fast-acting "vaccine" that can reverse the course of the disease in rats, and, they hope, in humans. Jon Lindstrom, PhD, a Trustee Professor in the department of Neuroscience led the study, published ...

Advocating weight diversity

2014-10-07
A new review of the way health care professionals emphasise weight to define health and wellbeing suggests the approach could be harmful to patients. Author of the review article, Dr Rachel Calogero of the School of Psychology at the University of Kent, together with experts from other institutions and organisations, recommends that this approach, known as 'weight-normative', is replaced by health care professionals, public health officials and policy-makers with a 'weight-inclusive' approach. Weight-inclusive approaches, such as the Health At Every Size initiative, ...

Hospitalized patients don't wash their hands enough, study finds

2014-10-07
Hamilton, ON (October 7, 2014) – Hospital visitors and staff are greeted with hand sanitizer dispensers in the lobby, by the elevators and outside rooms as reminders to wash their hands to stop infections, but just how clean are patients' hands? A study led by McMaster University researcher Dr. Jocelyn Srigley has found that hospitalized patients wash their hands infrequently. They wash about 30 per cent of the time while in the washroom, 40 per cent during meal times, and only three per cent of the time when using the kitchens on their units. Hand hygiene rates ...

LAST 30 PRESS RELEASES:

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

Healthy nutrition and physical lifestyle choices lower cancer mortality risk for survivors, new ACS study finds

[Press-News.org] Live and let-7: MicroRNA plays surprising role in cell survival