Showing posts with label cell biology. Show all posts
Showing posts with label cell biology. Show all posts

Wednesday, September 29, 2010

Sneaking Spies Into A Cell's Nucleus

Tuan Vo-Dinh, left, and Molly Gregas are researchers at Duke University. (Credit: Duke University Photography)

From Science Daily:

ScienceDaily (Sep. 28, 2010) — Duke University bioengineers have not only figured out a way to sneak molecular spies through the walls of individual cells, they can now slip them into the command center -- or nucleus -- of those cells, where they can report back important information or drop off payloads.

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Friday, September 10, 2010

A Cellular Secret To Long Life

From Science News:

Just as proper storage keeps a loaf fresh longer, adequate packaging may be a key to cellular longevity, reports a study of the organisms that make bread rise.

New research on aging in baker’s yeast suggests that proper packaging of DNA can halt aging and lead to longer life. The study, published September 10 in Molecular Cell, shows that a decline in levels of DNA-packaging proteins called histones is partially responsible for aging, and that making more of the proteins can extend the life-span of yeast.

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Monday, April 26, 2010

The Secrets Of Intelligence Lie Within A Single Cell

Modelling the neuron as little more than a simple on/off switch is a big mistake (Image: Dan Webber)

From The New Scientist:

LATE at night on a sultry evening, I watch intently as the predator senses its prey, gathers itself, and strikes. It could be a polecat, or even a mantis - but in fact it's a microbe. The microscopic world of the single, living cell mirrors our own in so many ways: cells are essentially autonomous, sentient and ingenious. In the lives of single cells we can perceive the roots of our own intelligence.

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Monday, March 15, 2010

Scientists Identify Driving Forces In Human Cell Division

Metaphase in a human cervical carcinoma (HeLa) cell. Chromosomes (red), microtubules (green). (Credit: Jason Swedlow, University of Dundee)

From Science Daily:

Science Daily (Mar. 14, 2010) — If you can imagine identical twin sisters at rest, their breath drawing them subtly together and apart, who somehow latch onto ropes that pull them to opposite sides of the bed -- you can imagine what happens to a chromosome in the dividing cell.

Understanding the forces that drive chromosome segregation -- a crucial aspect of human development and some diseases, including cancer -- is the goal of an international group of researchers who collaborate each summer at the MBL.

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Wednesday, February 3, 2010

Monitoring Cell Death Could Help Cancer Treatment

Image: Death of a tumor: This PET scan, taken just days after radiation therapy, shows a hot spot of cell-death activity in a brain tumor--a good indication that the therapy is working. Credit: Aaron Allen, Davidoff Comprehensive Cancer Center, Rabin Medical Center

From Technology Review:

An earlier measure of treatment could improve patients' prognosis.

When it comes to aggressive cancers, in the brain or lung for example, oncologists know that the sooner they can determine whether a treatment is unsuccessful, the sooner they can reevaluate and, if necessary, prescribe a new course of action. But typically, it takes two months or more to do the before-and-after comparisons that help determine whether a tumor is shrinking. Now an Israeli company called Aposense says it may have found a way to drastically speed up the process: an imaging marker that, when used with PET scans, indicates the presence of dying cells.

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Friday, January 29, 2010

Skin Cells Turned Into Brain Cells

Image: Cellular transformation: A cocktail of three genes can transform skin cells into neurons (shown here in red). Credit: Thomas Vierbuchen

From Technology Review:

A simple approach shows that cells might be more flexible than once thought.

Skin cells called fibroblasts can be transformed into neurons quickly and efficiently with just a few genetic tweaks, according to new research. The surprisingly simple conversion, which doesn't require the cells to be returned to an embryonic state, suggests that differentiated adult cells are much more flexible than previously thought.

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Saturday, October 10, 2009

Major Step Forward In Cell Reprogramming, Researchers Report

Lee Rubin, director of translational medicine at HSCI and the other senior author on the research team, said that "our goals were to try to as discretely and specifically as possible guide the cells through the deprogramming process" from the adult state to the embryonic-like state. (Credit: Photograph by Kris Snibbe/Harvard Staff Photographer)

From Science Daily:


ScienceDaily (Oct. 10, 2009) — A team of Harvard Stem Cell Institute (HSCI) researchers has made a major advance toward producing induced pluripotent stem cells, or iPS cells, that are safe enough to use in treating diseases in patients.

“This demonstrates that we’re halfway home, and remarkably we got halfway home with just one chemical,” said Kevin Eggan, an HSCI principal faculty member who is the senior author of the paper being published online today by the journal Cell Stem Cell.

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Monday, October 5, 2009

Vital Embryo Research Driven Out Of Britain

Professor Justin St John, who has left the UK for Australia (left); Sir Leszek Borysiewicz, of the MRC, which turned down one licence-holder (right). REX

From The Independent:

Scientists abandon plan to develop stem cells after funding dries up.

All research involving the controversial creation of animal-human "hybrid" embryos has been refused funding in Britain and one of the three scientists licensed to carry out the work has left the UK for a job in Australia.

Every one of the three projects to develop embryonic stem cells from cloned embryos created by fusing human cells with animal eggs has now been abandoned, after publicly-funded research councils refused to back the studies aimed at developing new treatments for incurable illnesses ranging from heart disease to Parkinson's.

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Mitochondrial Death Channels

Figure 1. A 53-year-old patient experiencing sporadic discomfort undergoes a coronary angiogram. The results are ominous. Severe stenosis (narrowing) is visible in the pinched regions (top middle), indicating the buildup of fatty deposits within the artery. If a wandering clot blocks the pinhole opening of a nearly clogged vessel, a heart attack ensues. With bloodflow blocked, cardiac cells downstream are starved for oxygen, leading to drastic metabolic changes as the cells struggle to survive. The most important changes affect mitochondria, the powerhouses of cell metabolism. The inset shows mitochondria (orange) arrayed among cardiac muscle fibrils (blue), where they are positioned to supply a steady stream of ATP to contracting muscle. Under oxidative stress, the mitochondria can also release potent effectors that lead directly to apoptosis—cell suicide. The trigger for the opening of the so-called mitochondrial death channels is, ironically, the return of oxygen to starved tissue during reperfusion. Learning to control the activities of the death channels could vastly improve the outlook for heart attack victims.

Top image by Zephyr/Photo Researchers, Inc.; bottom image by Steve Gschmeissner/Photo Researchers, Inc.

From American Scientist:


In heart attacks, cells die if they aren’t perfused with fresh oxygen—and kill themselves if they are. Understanding cell suicide may greatly improve outcomes.


Coronary artery disease is the leading cause of morbidity and mortality in North America and Europe. More than 12 million people in the United States have coronary artery disease, and more than 7 million have had a myocardial infarction (heart attack). Chronic stable angina (chest pain) is the initial manifestation of coronary artery disease in approximately half of all presenting patients, and about 16.5 million Americans (more than 5 percent) currently have stable angina.

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Saturday, October 3, 2009

Scientists Discover What Makes The Same Type Of Cells Different

Cell-to-cell variability in clathrin-mediated endocytosis (green signal) is determined by local cell density. (Credit: Image courtesy of ETH Zurich)

From Science Daily:

ScienceDaily (Oct. 3, 2009) — A research team led by Lucas Pelkmans at ETH Zürich has managed to decipher a well-known phenomenon that had, until now, remained unexplained: why cells of the same type can react differently, and what the reason for this is.

The properties of a cell population determine the different cell activities observed in cells of the same type. This is the conclusion drawn by a research team lead by Lucas Pelkmans, professor at the Institute for Molecular Systems Biology at ETH Zürich.

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Wednesday, June 17, 2009

Synthetic Cells Get Together To Make Electronics

Collections of a few protocells connected by shared membranes penetrated by pores (a) can be used in groups to perform as electronic devices (b), in this case as a rectifier, or AC to DC converter. (Image: Nature)

From New Scientist:

A network of artificial cells that work together to act as an AC/DC converter has been built. Demonstrating that synthetic cells can team up to achieve such feats is a step towards building synthetic tissues to interface biology with electronics, says the team of chemists behind the work.

Synthetic biologists have show they can reprogram living cells to make them produce drug compounds, and are even working towards building cells from scratch to create artificial life.

But that work focuses on only individual cells, says Hagan Bayley at the University of Oxford. He's more interested in making artificial tissue in which individual synthetic cells work together.

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Tuesday, June 2, 2009

Combined Stem Cell-Gene Therapy Approach Cures Human Genetic Disease In Vitro

Shown in green are genetically-corrected fibroblasts from Fanconi anemia patients are reprogrammed to generate induced pluripotent stem cells, which, in turn, can be differentiated into disease-free hematopoietic progenitors, capable of producing blood cells in vitro. (Credit: Courtesy of Dr. Juan-Carlos Belmonte, Salk Institute for Biological Studies)

From Science Daily:

ScienceDaily (June 1, 2009) — A study led by researchers at the Salk Institute for Biological Studies, has catapulted the field of regenerative medicine significantly forward, proving in principle that a human genetic disease can be cured using a combination of gene therapy and induced pluripotent stem (iPS) cell technology. The study is a major milestone on the path from the laboratory to the clinic.

"It's been ten years since human stem cells were first cultured in a Petri dish," says the study's leader Juan-Carlos Izpisúa Belmonte, Ph.D., a professor in the Gene Expression Laboratory and director of the Center of Regenerative Medicine in Barcelona (CMRB), Spain. "The hope in the field has always been that we'll be able to correct a disease genetically and then make iPS cells that differentiate into the type of tissue where the disease is manifested and bring it to clinic."

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Monday, May 25, 2009

Fundamental Mechanism For Cell Organization Discovered

Image: An embryo treated with RNA interference to delay the onset of cell polarization. At the beginning of the process, P granules (green) have already nearly completely dissolved throughout the embryo. However, when the embryo ultimately polarizes, the polarity protein PAR-2 (red) appears on the posterior cortex, and P granules reform by condensation in the vicinity of this posterior region. Credit: Clifford Brangwynne (Credit: Image courtesy of Marine Biological Laboratory)

From Science Digest:

ScienceDaily (May 22, 2009) — Scientists have discovered that cells use a very simple phase transition -- similar to water vapor condensing into dew -- to assemble and localize subcellular structures that are involved in formation of the embryo.

The discovery, which was made during the 2008 Physiology course at the Marine Biological Laboratory (MBL), is reported in the May 21 early online edition of Science by Clifford P. Brangwynne and Anthony A. Hyman of the Max Planck Institute for Molecular Cell Biology and Genetics in Dresden, Germany, and their colleagues, including Frank Jülicher of the Max Planck Institute for the Physics of Complex Systems, also in Dresden.

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Friday, April 17, 2009

RNA Used To Reprogram One Cell Type Into Another

Rat neuron with a micropipette inserting mRNAs directly onto the cell. After laser photoporation the mRNA goes into the cell and the TIPeR-induced changes in cell phenotype are initiated. (Credit: Chia-wen Wu, PhD and James Eberwine, PhD University of Pennsylvania School of Medicine)

From Science Daily:


ScienceDaily (Apr. 17, 2009) — For the past decade, researchers have tried to tweak cells at the gene and nucleus level to reprogram their identity. Now, working on the idea that the signature of a cell is defined by molecules called messenger RNAs, which contain the chemical blueprint for how to make a protein, researchers at the University of Pennsylvania School of Medicine, School of Arts and Sciences and School of Engineering have found another way to change one cell type into another.

By simply flooding one cell type, a nerve cell, with the an abundance of a specific type of messenger RNA (mRNA) from another cell type, the investigators changed a neuron into an astrocyte-like cell, a star-shaped brain cell that helps to maintain the blood-brain barrier, regulates the chemical environment around cells, responds to injury, and releases regulatory substances.

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Monday, March 2, 2009

From Stem Cells To New Organs: Scientists Cross Threshold In Regenerative Medicine

Computer-rendered image of human organs. New research suggests that bioengineered replacement organs may be closer thanks to a newly developed matrix on which stem cells can form a three-dimensional organ. (Credit: iStockphoto/Sebastian Kaulitzki)

From Science Daily:

ScienceDaily (Mar. 2, 2009) — By now, most people have read stories about how to "grow your own organs" using stem cells is just a breakthrough away. Despite the hype, this breakthrough has been elusive.

A new report brings bioengineered organs a step closer, as scientists from Stanford and New York University Langone Medical Center describe how they were able to use a "scaffolding" material extracted from the groin area of mice on which stem cells from blood, fat, and bone marrow grew. This advance clears two major hurdles to bioengineered replacement organs, namely a matrix on which stem cells can form a three-dimensional organ and transplant rejection.

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Monday, February 23, 2009

Scientists Expect To Create Life In Next 10 years

This photo, provided by ProtoLife, shows vesicles, artificial membranes for cells, made from scratch. Teams around the world, including ProtoLife, are trying to create synthetic life in a lab. Martin Hanczyc / AP

From MSNBC/AP:

First cell of synthetic life can only be seen under a microscope.

WASHINGTON - Around the world, a handful of scientists are trying to create life from scratch and they’re getting closer.

Experts expect an announcement within three to 10 years from someone in the now little-known field of “wet artificial life.”

“It’s going to be a big deal and everybody’s going to know about it,” said Mark Bedau, chief operating officer of ProtoLife of Venice, Italy, one of those in the race. “We’re talking about a technology that could change our world in pretty fundamental ways — in fact, in ways that are impossible to predict.”

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Sunday, February 22, 2009

Single-celled Algae Took The Leap To Multicellularity 200 Million Years Ago

Pleodorina starrii has an incomplete division of labor. Although the 12 small cells near the top of this colony only swim, the 20 larger cells both swim and reproduce. (Credit: Copyright 2008 Matthew Herron)

From Science Daily:

ScienceDaily (Feb. 22, 2009) — Some algae have been hanging together rather than going it alone much longer than previously thought, according to new research.

Ancestors of Volvox algae made the transition from being a single-celled organism to becoming a multicellular colony at least 200 million years ago, during the Triassic Period.

At that time, Earth was a hot-house world whose inhabitants included tree ferns, dinosaurs and early mammals. Previous estimates had suggested Volvox's ancestors arose only 50 million years ago.

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Thursday, August 28, 2008

Converting One Cell Into Another


Going From One Cell Type to Another Without
Using Stem Cells -- Wired Science


In an unprecedented flourish of genetic alchemy, scientists used a virus to coax one type of cell to become another, without the intermediate stem cell step.

The research, conducted with cells from the pancreas, could soon be used to treat people with diabetes -- but its long-term impacts could be even greater.

"This represents a parallel approach for how to make cells in regenerative medicine," said Douglas Melton, co-director of the Harvard Stem Cell Institute. "And now that it's shown that you can turn one of your cells into another, it makes you think of what other cells you'd like to convert."

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