Corporate Banner
Satellite Banner
Technology
Networks
Scientific Communities
 
Become a Member | Sign in
Home>News>This Article
  News
Return

Cells, Cell Fragments Move in Opposing Directions

Published: Wednesday, April 03, 2013
Last Updated: Wednesday, April 03, 2013
Bookmark and Share
Like tiny, crawling compass needles, whole living cells and cell fragments orient and move in response to electric fields — but in opposite directions.

Their results, published April 8 in the journal Current Biology, could ultimately lead to new ways to heal wounds and deliver stem cell therapies.

When cells crawl into wounded flesh to heal it, they follow an electric field. In healthy tissue there's a flux of charged particles between layers. Damage to tissue sets up a "short circuit," changing the flux direction and creating an electrical field that leads cells into the wound. But exactly how and why does this happen? That’s unclear.

"We know that cells can respond to a weak electrical field, but we don't know how they sense it," said Min Zhao, professor of dermatology and ophthalmology and a researcher at UC Davis' stem cell center, the Institute for Regenerative Cures. "If we can understand the process better, we can make wound healing and tissue regeneration more effective.”

The researchers worked with cells that form fish scales, called keratocytes. These fish cells are commonly used to study cell motion, and they also readily shed cell fragments, wrapped in a cell membrane but lacking a nucleus, major organelles, DNA or much else in the way of other structures.

In a surprise discovery, whole cells and cell fragments moved in opposite directions in the same electric field, said Alex Mogilner, professor of mathematics and of neurobiology, physiology and behavior at UC Davis and co-senior author of the paper.

It's the first time that such basic cell fragments have been shown to orient and move in an electric field, Mogilner said. That allowed the researchers to discover that the cells and cell fragments are oriented by a "tug of war" between two competing processes.

Think of a cell as a blob of fluid and protein gel wrapped in a membrane. Cells crawl along surfaces by sliding and ratcheting protein fibers inside the cell past each other, advancing the leading edge of the cell while withdrawing the trailing edge.

Assistant project scientist Yaohui Sun found that when whole cells were exposed to an electric field, actin protein fibers collected and grew on the side of the cell facing the negative electrode (cathode), while a mix of contracting actin and myosin fibers formed toward the positive electrode (anode). Both actin alone, and actin with myosin, can create motors that drive the cell forward.

The polarizing effect set up a tug-of-war between the two mechanisms. In whole cells, the actin mechanism won, and the cell crawled toward the cathode. But in cell fragments, the actin/myosin motor came out on top, got the rear of the cell oriented toward the cathode, and the cell fragment crawled in the opposite direction.

The results show that there are at least two distinct pathways through which cells respond to electric fields, Mogilner said. At least one of the pathways — leading to organized actin/myosin fibers — can work without a cell nucleus or any of the other organelles found in cells, beyond the cell membrane and proteins that make up the cytoskeleton.

Upstream of those two pathways is some kind of sensor that detects the electric field. In a separate paper to be published in the same journal issue, Mogilner and Stanford University researchers Greg Allen and Julie Theriot narrow down the possible mechanisms. The most likely explanation, they conclude, is that the electric field causes certain electrically charged proteins in the cell membrane to concentrate at the membrane edge, triggering a response.

The team also included Hao Do, Jing Gao and Ren Zhao, all at the Institute for Regenerative Cures and the UC Davis departments of Ophthalmology and Dermatology. Sun is co-advised by Mogilner and Zhao; Gao is now working at Yunnan Normal University, Kunming, China, and Ren Zhao is at the Third Military Medical University, Chongqing, China.

The work was funded by the National Institutes of Health, the California Institute for Regenerative Medicine and the National Science Foundation.


Further Information

Join For Free

Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 2,900+ scientific posters on ePosters
  • More Than 4,200+ scientific videos on LabTube
  • 35 community eNewsletters


Sign In



Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into TechnologyNetworks.com you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Related Content

Cat Stem Cell Therapy Gives Humans Hope
By the time Bob the cat came to the UC Davis veterinary hospital, he had used up most of his nine lives.
Monday, February 08, 2016
Crowdfunding the Fight Against Cancer
From budding social causes to groundbreaking businesses to the next big band, crowdfunding has helped connect countless worthy projects with like-minded people willing to support their efforts, even in small ways. But could crowdfunding help fight cancer?
Monday, February 08, 2016
Toxic Pollutants Found in Fish Across the World's Oceans
Scripps researchers' analysis shows highly variable pollutant concentrations in fish meat.
Friday, January 29, 2016
Key Enzyme in Pierce’s Disease Grapevine Damage Uncovered
UC Davis plant scientists have identified an enzyme that appears to play a key role in the insect-transmitted bacterial infection of grapevines with Pierce’s disease, which annually costs California’s grape and wine industries more than $100 million.
Wednesday, January 13, 2016
Science Magazine Names CRISPR ‘Breakthrough of the Year’
In its year-end issue, the journal Science chose the CRISPR genome-editing technology invented at UC Berkeley 2015’s Breakthrough of the Year.
Monday, December 21, 2015
Genome Sequencing May Save California's Legendary Sugar Pine
The genome of California’s legendary sugar pine, which naturalist John Muir declared to be “king of the conifers” more than a century ago, has been sequenced by a research team led by UC Davis scientists.
Thursday, December 17, 2015
Cellular “ORACLs” to Aid Drug Discovery
New approach for finding therapeutics is inspired by face-recognition software.
Wednesday, December 16, 2015
New Virus Disovered, Linked To Hepatitis C
Study is first to reveal entire genetic makeup of human pegivirus 2.
Tuesday, December 15, 2015
CRISPR-Cas9 Helps Uncover Genetics of Exotic Organisms
A new study illustrates the ease with which CRISPR-Cas9 can knock out genes in exotic animals to learn how those genes control growth and development.
Friday, December 11, 2015
UC Davis Cracks the Walnut Genome
Scientists at the University of California, Davis, have for the first time sequenced the genome of a commercial walnut variety.
Friday, December 11, 2015
‘Purity’ Of Tumor Samples May Significantly Bias Genomic Analyses
Non-cancerous tumor components influence research findings, clinical classifications, study shows.
Monday, December 07, 2015
New Method for Screening Cancer Cells
Parallel microfiltration could lead to better treatments for a number of diseases, UCLA-led study says.
Thursday, December 03, 2015
Embryonic Switch for Cancer Stem Cell Generation
An international team of scientists report that decreases in a specific group of proteins trigger changes in the cancer microenvironment that accelerate growth and development of therapy-resistant cancer stem cells (CSCs).
Wednesday, December 02, 2015
New Organic Plant Breeding Effort Launched
A new effort to provide California growers with seeds for tomato, bean, pepper and other crop varieties that are specially bred for organic farming has been launched at UC Davis.
Tuesday, December 01, 2015
When it Comes to Breast Cancer, Common Pigeon is No Bird Brain
If pigeons went to medical school and specialized in pathology or radiology, they’d be pretty good at distinguishing digitized microscope slides and mammograms of normal vs. cancerous breast tissue, a new study has found.
Monday, November 30, 2015
Scientific News
Food Triggers Creation of Regulatory T Cells
IBS researchers document how normal diet establishes immune tolerance conditions in the small intestine.
Light Signals from Living Cells
Fluorescent protein markers delivered under high pressure.
Counting Cancer-busting Oxygen Molecules
Researchers from the Centre for Nanoscale BioPhotonics (CNBP), an Australian Research Centre of Excellence, have shown that nanoparticles used in combination with X-rays, are a viable method for killing cancer cells deep within the living body.
Therapeutic Approach Gives Hope for Multiple Myeloma
A new therapeutic approach tested by a team from Maisonneuve-Rosemont Hospital (CIUSSS-EST, Montreal) and the University of Montreal gives promising results for the treatment of multiple myeloma, a cancer of the bone marrow currently considered incurable with conventional chemotherapy and for which the average life expectancy is about 6 or 7 years.
Cellular 'Relief Valve'
A team led by scientists at The Scripps Research Institute (TSRI) has solved a long-standing mystery in cell biology by showing essentially how a key “relief-valve” in cells does its job.
Genomic Signature Shared by Five Types of Cancer
National Institutes of Health researchers have identified a striking signature in tumor DNA that occurs in five different types of cancer.
Protein Protects Against Flu in Mice
The engineered molecule doesn’t provoke inflammation and may hail a new class of antivirals.
Cat Stem Cell Therapy Gives Humans Hope
By the time Bob the cat came to the UC Davis veterinary hospital, he had used up most of his nine lives.
Crowdfunding the Fight Against Cancer
From budding social causes to groundbreaking businesses to the next big band, crowdfunding has helped connect countless worthy projects with like-minded people willing to support their efforts, even in small ways. But could crowdfunding help fight cancer?
Switch Lets Salmonella Fight, Evade Immune System
Researchers at the University of Illinois at Chicago have discovered a molecular regulator that allows salmonella bacteria to switch from actively causing disease to lurking in a chronic but asymptomatic state called a biofilm.
Scroll Up
Scroll Down
Skyscraper Banner

Skyscraper Banner
Go to LabTube
Go to eposters
 
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
2,900+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
4,200+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FOR FREE!