Aging gracefully requires taking out the trash

Suppressing a cellular cleanup-mechanism known as autophagy can accelerate the accumulation of protein aggregates that leads to neural degeneration. In an upcoming issue of Autophagy, scientists at the Salk Institute for Biological Studies report for the first time that the opposite is true as well: Boosting autophagy in the nervous system of fruit flies prevented the age-dependent accumulation of cellular damage in neurons and promoted longevity.

 

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10-fold life span extension reported in simple organism

Biologists have created baker’s yeast capable of living to 800 in yeast years without apparent side effects. The basic but important discovery, achieved through a combination of dietary and genetic changes, brings science closer to controlling the survival and health of the unit of all living systems: the cell.

Researchers discover a gene that might control fat accumulation

Researchers at UT Southwestern Medical Center have found that a single gene might control whether or not individuals tend to pile on fat, a discovery that may point to new ways to fight obesity and diabetes.

“From worms to mammals, this gene controls fat formation,” said Dr. Jonathan Graff, associate professor of developmental biology and internal medicine at UT Southwestern and senior author of a study appearing in the Sept. 5 issue of Cell Metabolism. “It could explain why so many people struggle to lose weight and suggests an entirely new direction for developing medical treatments that address the current epidemic of diabetes and obesity.

“People who want to fit in their jeans might someday be able to overcome their genes.”

MIT creates 3D images of living cell

A new imaging technique developed at MIT has allowed scientists to create the first 3D images of a living cell, using a method similar to the X-ray CT scans doctors use to see inside the body.

The technique, described in a paper published in the Aug. 12 online edition of Nature Methods, could be used to produce the most detailed images yet of what goes on inside a living cell without the help of fluorescent markers or other externally added contrast agents, said Michael Feld, director of MIT’s George R. Harrison Spectroscopy Laboratory and a professor of physics.

 

A new brake on cellular energy production discovered

A condition that has to be met for the body to be able to keep warm, move and even survive is that the mitochondria – the cells’ power stations – release the right amounts of energy. Scientists at Karolinska Institutet have now identified the first known factor that acts as a brake on cellular energy production.

Evidence found for novel brain cell communication

n article published today in Proceedings of the National Academy of Sciences provides strong evidence for a novel type of communication between nerve cells in the brain. The findings may have relevance for the prevention and treatment of epilepsy, and possibly in the exploration of other aspects of brain functions, from creative thought processes to mental illnesses such as schizophrenia.

Scientists find brown fat master switch

Researchers at Dana-Farber Cancer Institute have identified a long-sought “master switch” in mice for the production of brown fat, a type of adipose tissue that generates heat and counters obesity caused by overeating.

A team headed by Bruce Spiegelman, PhD, suggests in the July issue of Cell Metabolism that turning up the equivalent switch in people might be a new strategy for treating overweight and obesity. The investigators said their next step is to rev up the control in mice and overfeed them to see if they are resistant to becoming obese.

Researchers reverse symptoms in mice of leading inherited cause of mental retardation

Researchers at the Picower Institute for Learning and Memory at MIT have, for the first time, reversed symptoms of mental retardation and autism in mice.

The mice were genetically manipulated to model Fragile X Syndrome (FXS), the leading inherited cause of mental retardation and the most common genetic cause of autism. The condition, tied to a mutated X chromosome gene called fragile X mental retardation 1 (FMR1) gene, causes mild learning disabilities to severe autism.

Recording a Cell’s Dying Gasp

Scientists in the United Kingdom have developed a way to monitor the health of individual cells by recording their electrical activity in much the same way that an electrocardiogram (EKG) monitors the heart. They say that the technique could revolutionize the way we test drugs and carry out environmental sensing. Using extremely sensitive equipment, the scientists have captured the last pulse of electrical activity in a cell, the equivalent of a final heartbeat, before the cell died.

Life signs: Superconducting electrodes (pink) act like leads of an electrocardiogram, measuring the electrical activity of an individual yeast cell (yellow blob). Credit: Dr. Irina Barbolina, University of Manchester

Read rest of this story on Technology Review site.

Scientists unlock mystery of embryonic stem cell signaling pathway

A newly discovered small molecule called IQ-1 plays a key role in preventing embryonic stem cells from differentiating into one or more specific cell types, allowing them to instead continue growing and dividing indefinitely, according to research performed by a team of scientists who have recently joined the stem-cell research efforts at the Keck School of Medicine of the University of Southern California.

Scientists develop new procedure to differentiate human embryonic stem cells

Scientists have developed a new procedure for the differentiation of human embryonic stem cells, with which they have created the first transplantable source of lung epithelial cells.

The method involves the use of protein markers under the control of cell-specific promoters to convert undifferentiated human embryonic stem cells into highly-specialized cells. The human embryonic stem cells were cultured on specially coated dishes and transfected with a lung epithelial gene regulator of a drug selection gene.

Regulating the nuclear architecture of the cell

An organelle called the nucleolus resides deep within the cell nucleus and performs one of the cell’s most critical functions: it manufactures ribosomes, the molecular machines that convert the genetic information carried by messenger RNA into proteins that do the work of life.

Gary Karpen and Jamy Peng, researchers in the Life Sciences Division of the Department of Energy’s Lawrence Berkeley National Laboratory, have now discovered two pathways that regulate the organization of the nucleolus and other features of nuclear architecture, maintaining genome stability in the fruit fly Drosophila melanogaster.

Major breakthrough in the mechanism of myelin formation

The discovery reported in this study sheds light on the mechanisms that control how myelin is formed during development of the nerves. The article, which will be published in the November 3rd issue of Science, constitutes an important step forward in our understanding of the process of myelination, and opens the way to new research in this field. The results of their study that could have a major impact on the treatment of diseases such as multiple sclerosis, and peripheral neuropathies.

Technique reveals inner lives of red blood cells

For the first time, researchers at MIT can see every vibration of a cell membrane, using a technique that could one day allow scientists to create three-dimensional images of the inner workings of living cells.

Studying cell membrane dynamics can help scientists gain insight into diseases such as sickle cell anemia, malaria and cancer. Using a technique known as quantitative phase imaging, researchers at MIT’s George R. Harrison Spectroscopy Laboratory can see cell membrane vibrations as tiny as a few tens of nanometers (billionths of a meter).

Researchers discover misfolded protein clumps common to dementia, Lou Gehrig’s disease

Scientists have identified a misfolded, or incorrectly formed, protein common to two devastating neurological diseases, frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS, also known as Lou Gehrig’s disease), according to a report in the Oct. 6, 2006, issue of Science. The findings suggest that certain forms of FTD, ALS and possibly other neurological diseases might share a common pathological process.

Molecular mechanism provides intra-cellular traffic signal

City planners could learn a lesson or two from tiny cells on how to maximize traffic flow.

Researchers at the University of Illinois at Chicago have found that intra-cellular trafficking is tightly coordinated for maximum flow through cellular compartments — much as vehicles on a crowded road are allowed to pass quickly through a succession of green traffic lights.

Scientists prove that parts of cell nuclei are not arranged at random

The nucleus of a mammal cell is made up of component parts arranged in a pattern which can be predicted statistically, says new research published today. Scientists hope this discovery that parts of the inside of a cell nucleus are not arranged at random will give greater insight into how cells work and could eventually lead to a greater understanding of how they become dysfunctional in diseases like cancer.

Researchers discover a protein as potential tactic to prevent tumors

Mayo Clinic researchers have found that a protein that initiates a “quality control check” during cell division also directs cell death for those cells damaged during duplication. This knowledge represents a potential “bulls eye” for targeting anti-tumor drugs. The findings appear in the current issue of Science.

Scientists provide insights into how the immune system avoids attacking itself

finding by University of Pennsylvania School of Medicine researchers about how immune cells “decide” to become active or inactive may have applications in fighting cancerous tumors, autoimmune diseases, and organ transplant rejection. Pathology and Laboratory Medicine Professor Gary A. Koretzky, MD, PhD, director of the Signal Transduction Program at Penn’s Abramson Family Cancer Research Institute describes, in the current issue of Nature Immunology, one way in which T cells may develop tolerance to host cells and proteins. Koretzky and colleagues found that small fatty acids called diacylglycerols (DAGs), and the enzymes that metabolize them, are critical players in the molecular pathway that leads to activity versus inactivity.

Researchers map out networks that determine cell fate

A two-step process appears to regulate cell fate decisions for many types of developing cells, according to researchers from the University of Chicago.

This finding sheds light on a puzzling behavior. For some differentiating stem cells, the first step leads not to a final decision but to a new choice. In response to the initial chemical signal, these cells take on the genetic signatures of two different cell types. It often requires a second signal for them to commit to a single cellular identity.

Genome code cracked for breast and colon cancers

Scientists have completed the first draft of the genetic code for breast and colon cancers. Their report, published online in the September 7 issue of Science Express, identifies close to 200 mutated genes, now linked to these cancers, most of which were not previously recognized as associated with tumor initiation, growth, spread or control.

Scientists report full humanization of yeast glycosylation pathway

For the first time, scientists have engineered yeast cells capable of producing a broad repertoire of recombinant therapeutic proteins with fully human sugar structures (glycosylation). These sugar structures ensure a glycoprotein’s biological activity and half-life and to date, have necessitated the expression of therapeutic glycoproteins in mammalian hosts. The accomplishment reported today has the potential to eliminate the need for mammalian cell culture, while improving control over glycosylation, and improving performance characteristics of many therapeutic proteins.

Mapping system tells skin cells whether to become scalp or palm tissues

Global-positioning system aficionados know that it’s possible to precisely define any location in the world with just three geographic coordinates: latitude, longitude and altitude. Now scientists at the Stanford University School of Medicine have discovered that specialized skin cells use a similar mapping system to identify where they belong in the body and how to act once they arrive.

These cellular cornerstones direct embryonic patterning and wound healing by sending vital location cues to their neighbors, and may help in growing tissue for transplant or understanding metastatic cancer.

Researchers find new way to open ion channels in cell membranes

Using an enzyme found in the venom of the brown recluse spider, researchers at the University of Pennsylvania School of Medicine have discovered a new way to open molecular pores, called ion channels, in the membrane of cells. The research team screened venoms from over 100 poisonous invertebrate species to make this discovery.

The enzyme, sphingomyelinase D (SMase D), splits a lipid called sphingomyelin that surrounds the channel embedded in the cell membrane. As a result, the channel opens to allow the passage of small ions into and out of the cell, thereby generating electrical currents.

Medium is the message for stem cells in search of identities

Embryonic stem cells, prized for their astonishing ability to apparently transform into any kind of cell in the body, acquire their identities in part by interacting with their surroundings – even when they are outside of the body in a laboratory dish, University of Florida scientists report.

Using an animal model of embryonic stem cell development, researchers with UF’s McKnight Brain Institute have begun to answer one of the most fundamental questions in science – how does a batch of immature cells give rise to an organ as extraordinarily complex as the human brain?

The findings, to be published this week in the Proceedings of the National Academy of Sciences, may one day help scientists create laboratory environments to grow specialized cells that can be transplanted into patients to treat epilepsy, Parkinson’s, Huntington’s and Alzheimer’s diseases or other brain disorders.

Researchers discover new cell properties in accelerated aging process

Carnegie Mellon University researchers Kris Noel Dahl and Mohammad F. Islam have made a new breakthrough for children suffering from an extremely rare disease that accelerates the aging process by about seven times the normal rate. Researchers found that children suffering from Hutchinson-Gilford Progeria Syndrome (HGPS) have an excessively stiff shell of proteins.

New roles for growth factors: Enticing nerve cells to muscles

During embryonic development, nerve cells hesitantly extend tentacle-like protrusions called axons that sniff their way through a labyrinth of attractive and repulsive chemical cues that guide them to their target.

While several recent studies discovered molecules that repel motor neuron axons from incorrect targets in the limb, scientists at the Salk Institute for Biological Studies have identified a molecule, known as FGF, that actively lures growing axons closer to the right destination. Their findings appear in the June 15 issue of Neuron.

New Mechanism Explains Glucose Effect On Wakefulness

One of the body's basic survival mechanisms is the neural machinery that triggers the hungry brain to the alertness needed for seeking food. That same machinery swings the other way after a hearty meal, as exemplified by the long and honored custom of the siesta. However, scientists have understood little about how the basic energy molecule, glucose, regulates such wakefulness and other energy-related behaviors.

Now, in an article in the June 1, 2006, Neuron, Denis Burdakov of the University of Manchester and his colleagues have pinpointed how glucose inhibits neurons that are key to regulating wakefulness. In the process, they have discovered a role for a class of potassium ion channels whose role has remained largely unknown. Such ion channels are porelike proteins in the cell membrane that affect cellular responses by controlling the flow of potassium into the cell.

Free Radical Cell Death Switch Identified

"A common molecular denominator in aging and many age-related diseases is oxidative stress," says the study's lead author Azad Bonni, MD, PhD, HMS associate professor of pathology. The skin of a bitten apple will brown because of its exposure to air, and in some ways that is a good metaphor for the damage that oxidative stress is causing to neurons and other types of cells over time.

How the oxidative-stress signals trigger these profound effects in cells has remained unclear. But Bonni and his research team, have now defined how a molecular chain-of-events links oxidative-stress signals to cell death in brain neurons.

Fluorescent Nanosensor Detects Cell Death

A team of investigators at Massachusetts General Hospital has developed a nanoparticle that signals when cells are undergoing apoptosis, the kind of cell death triggered by cancer therapies. The new nanoparticles could finally provide oncologists with a rapid assay that could tell them that a given therapy is working. This groundbreaking work was published in the journal Nano Letters.

A New Way of Looking at Molecular Motors

An innovative method of categorizing myosin—one of three molecular “motors” that produce movement within the cells of the body—has dramatically increased the amount of information available about these essential proteins. The studies lay the groundwork for development of treatments for conditions ranging from certain kinds of blindness and kidney disease to neurodegenerative disorders and parasitic diseases such as malaria.

How sperm move their tail in a whip-cracking motion

Researchers have identified a key component of the mechanism spermatozoa use to abruptly convert their tail motion from a steady swimming undulation to the whip-cracking snap that thrusts them into an egg.

The finding opens a new research pathway that the researchers said could help scientists both recognize new forms of male infertility and design new contraceptives to thwart sperm entry into the egg.

Researchers provide fresh evidence for aging cells causing aging body

Brown University biologists have uncovered intriguing evidence to support the theory that old cells help make old bodies. In a study of baboons, scientists showed that as these animals age, the number of aging cells in their skin significantly increases.

Over time, cells lose their ability to divide, a state known as replicative senescence. The new research, published in an advanced online edition of Science, is the first to quantify the presence of replicatively senescent cells in any species.

Decoding the cellular machinary

Researchers from Germany announce they have finished the first complete analysis of the “molecular machines” in one of biology’s most important model organisms: S. cerevisiae (baker’s yeast).

The study combined a method of extracting complete protein complexes from cells (tandem affinity purification, developed in 2001 by Bertrand Séraphin at EMBL), mass spectrometry and bioinformatics to investigate the entire protein household of yeast, turning up 257 machines that had never been observed. It also revealed new components of nearly every complex already known.

Modified Atomic Force Microscopy Proves Critical to Uncovering Cell-growth Secret

Researchers using a customized atomic force microscope (AFM) have discovered new evidence for how the fibrous scaffolding within our cells, which is made of the protein actin, responds to obstacles in its environment.

The discovery demonstrates a technique for tracking a cell’s growth history, and if it proves valid outside of the laboratory, researchers may one day look for actin-growth clues while tracking the pathways of spreading cancers, immune cells, and other free-moving cells that crawl throughout the body.