Featured Research

from universities, journals, and other organizations

How do our cells move? Liquid droplets could explain

Date:
May 1, 2014
Source:
Ecole Polytechnique Fédérale de Lausanne
Summary:
Living cells move; not just bacteria, but also cells in our own bodies. Scientists have discovered a new relationship between the three-dimensional shape of the cell and its ability to migrate. The work has important implications for the fundamental understanding of cell movement and for practical applications like tissue engineering.

Cells migrating off a fish scale.
Credit: © 2014 EPFL

'Cell migration' is a broad term for all the processes associated with the movement of cells from one location to another. It lies at the core of biological processes like embryonic development, immune responses and wound healing, but also autoimmune diseases and metastasis of cancerous cells. Cell migration is achieved through the movement of the cell's membrane, which is powered by the action of a protein network inside the cell. However, this interaction is affected by the cell's overall shape, but exactly how this takes place is unclear. Publishing in Current Biology, EPFL scientists have discovered an unexpected link between the 3D shape of the cell and its migration efficiency, and have explained its physics using a simple model of a liquid droplet.

The first step in cell migration occurs when the cell extends its front edge -- a process called 'protrusion'. This is driven by the growth of the filaments of the protein actin, which push the cell membrane from inside. Simultaneously, membrane tension controls protrusion by providing resistance protecting the cell from over-extending. But physical laws (e.g. Laplace's law) dictate that the shape of the cell membrane must play a role in the balance between force exerted by actin and the resisting membrane tension. However, this was not taken into account in previous studies, which used simplified 2D models of migrating cells.

Now, Chiara Gabella and Alexander Verkhovsky at EPFL have determined the relationship between cell protrusion, shape and membrane tension. Using a model cell type taken from fish scales, the researchers developed a fast and simple way to evaluate the 3D shape of migrating cells by observing them in a chamber filled with a fluorescent solution. By applying various treatments to swell, shrink, or stretch the cells, they were able to observe their impact on membrane tension, shape, and protrusion velocity. The treatments only affected the cells' shape and migration speed, but not membrane tension. The overall conclusion was that that the more spherical the cell, the faster it moves.

In order to interpret these unexpected findings, the researchers modeled a migrating cell as a liquid droplet spreading on a surface. "It is well known that a droplet's shape and, in particular, the contact angle that it makes with the surface are determined by the tension forces between the droplet, its environmental medium (e.g. air or a different liquid) and the surface on which it moves," says Gabella. The researchers considered the protruding edge of the cell as such a triple interface, but also added the tension from growing actin filaments inside the cell.

"From this point of view, a more spherical cell means less load for actin filaments to overcome, and therefore faster actin growth and migration," explains Verkhovsky. In support of this idea, the researchers found that the cells were also sensitive to the surface's characteristics just as droplets would be, by slowing down or being pinned at ridges.

"The emphasis of many studies has been on discovering and characterizing individual cellular components," says Verkhovsky. "This is rooted in the common belief that a cell's behavior is determined by intricate networks of genes and proteins." In contrast, this work shows that, despite their enormous molecular complexity, cells can be described as physical objects. The findings point to a new relationship between a cell's shape and its dynamics, and may help to understand how cell migration is guided by the cell's 3D environment.


Story Source:

The above story is based on materials provided by Ecole Polytechnique Fédérale de Lausanne. Note: Materials may be edited for content and length.


Journal Reference:

  1. Chiara Gabella, Elena Bertseva, Céline Bottier, Niccolň Piacentini, Alicia Bornert, Sylvia Jeney, László Forró, Ivo F. Sbalzarini, Jean-Jacques Meister, Alexander B. Verkhovsky. Contact Angle at the Leading Edge Controls Cell Protrusion Rate. Current Biology, 2014; DOI: 10.1016/j.cub.2014.03.050

Cite This Page:

Ecole Polytechnique Fédérale de Lausanne. "How do our cells move? Liquid droplets could explain." ScienceDaily. ScienceDaily, 1 May 2014. <www.sciencedaily.com/releases/2014/05/140501123457.htm>.
Ecole Polytechnique Fédérale de Lausanne. (2014, May 1). How do our cells move? Liquid droplets could explain. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2014/05/140501123457.htm
Ecole Polytechnique Fédérale de Lausanne. "How do our cells move? Liquid droplets could explain." ScienceDaily. www.sciencedaily.com/releases/2014/05/140501123457.htm (accessed July 31, 2014).

Share This




More Plants & Animals News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Thousands Flocking to German Crop Circle

Raw: Thousands Flocking to German Crop Circle

AP (July 30, 2014) — Thousands of people are trekking to a Bavarian farmer's field to check out a mysterious set of crop circles. (July 30) Video provided by AP
Powered by NewsLook.com
Concern Grows Over Worsening Ebola Crisis

Concern Grows Over Worsening Ebola Crisis

AFP (July 30, 2014) — Pan-African airline ASKY has suspended all flights to and from the capitals of Liberia and Sierra Leone amid the worsening Ebola health crisis, which has so far caused 672 deaths in Guinea, Liberia and Sierra Leone. Duration: 00:43 Video provided by AFP
Powered by NewsLook.com
At Least 20 Chikungunya Cases in New Jersey

At Least 20 Chikungunya Cases in New Jersey

AP (July 30, 2014) — At least 20 New Jersey residents have tested positive for chikungunya, a mosquito-borne virus that has spread through the Caribbean. (July 30) Video provided by AP
Powered by NewsLook.com
Xtreme Eating: Your Daily Caloric Intake All On One Plate

Xtreme Eating: Your Daily Caloric Intake All On One Plate

Newsy (July 30, 2014) — The Center for Science in the Public Interest released its 2014 list of single meals with whopping calorie counts. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

    Technology News



      Save/Print:
      Share:  

      Free Subscriptions


      Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

      Get Social & Mobile


      Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

      Have Feedback?


      Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
      Mobile iPhone Android Web
      Follow Facebook Twitter Google+
      Subscribe RSS Feeds Email Newsletters
      Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins