About Careers Internship MedBlog Contact us
Medindia LOGIN REGISTER
Advertisement

Scientists Explain How Cells and Cell Fragments Move in Electric Fields

by Rukmani Krishna on March 30, 2013 at 11:51 PM
 Scientists Explain How Cells and Cell Fragments Move in Electric Fields

Scientists at the University of California, Davis, have found that 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.

Advertisement

"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's 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.
Advertisement

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 on 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 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.

Source: Eurekalert
Font : A-A+

Advertisement

Advertisement
Advertisement

Latest General Health News

Hawk Data Pro: An Essential One Health Surveillance Tool for Rabies Management
Implementing the Hawk Data Pro system as a passive surveillance tool enabled us to record an ongoing rabies outbreak within a major Indian metropolis.
Wild Poliovirus Resurfaces in Pakistan
The Pakistan Ministry has announced the commencement of a nationwide polio vaccination campaign beginning on October 2, aiming to immunize more children.
US Woman Loses All Limbs in Fish-Related Bacterial Outbreak
In a tragic incident, a woman in the US experienced the loss of all her limbs as a result of a bacterial outbreak linked to the consumption of contaminated fish.
NIH Launches the First In-Human Universal Flu Vaccine Trial
FluMos-v2, a unique universal influenza vaccine candidate, undergoing a phase 1 trial at NIH, increases recipients' immunity against many influenza viruses.
Global Polio Eradication Initiative Assesses Vaccination Strategies in Pakistan
In Pakistan, the polio campaign focuses on more than 270,000 children under the age of five years, residing in areas with insufficient vaccine coverage.
View All
This site uses cookies to deliver our services.By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Use  Ok, Got it. Close
MediBotMediBot
Greetings! How can I assist you?MediBot
×

Scientists Explain How Cells and Cell Fragments Move in Electric Fields Personalised Printable Document (PDF)

Please complete this form and we'll send you a personalised information that is requested

You may use this for your own reference or forward it to your friends.

Please use the information prudently. If you are not a medical doctor please remember to consult your healthcare provider as this information is not a substitute for professional advice.

Name *

Email Address *

Country *

Areas of Interests