Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The dance of the cells: A minuet or a mosh?

23.05.2011
The physical forces that guide how cells migrate—how they manage to get from place to place in a coordinated fashion inside the living body— are poorly understood.

Scientists at the Harvard School of Public Health (HSPH) and the Institute for Bioengineering of Catalonia (IBEC) have, for the first time, devised a way to measure these forces during collective cellular migration. Their surprising conclusion is that the cells fight it out, each pushing and pulling on its neighbors in a chaotic dance, yet together moving cooperatively toward their intended direction.

The study appears May 22, 2011, in an advance online edition of Nature Materials.

Until now it was known that cells could follow gradients of soluble chemical cues, called morphogens, which help to direct tissue development, or they could follow physical cues, such as adhesion to their surroundings. Fundamental studies of these and other mechanisms of cellular migration have focused on dissecting cell behavior into ever smaller increments, trying to get to the molecular roots of how migration occurs. In contrast, the HSPH team worked at a higher level—the group level—and focused upon the forces that cells exert upon their immediate neighbors, to begin to resolve the riddle of collective cellular migration.

Collective cellular migrations are necessary for multicellular life; for example, in order for cells to form the embryo, cells must move collectively. Or in the healing of a wound, cells must migrate collectively to fill the wound gap. But the migration process is also dangerous in situations such as cancer, when malignant cells, or clumps of cells, can migrate to distant sites to invade other tissues or form new tumors. Understanding how and why collective cellular migration happens may lead to ways to control or interrupt diseases that involve abnormal cell migration.

The laboratories of Jeffrey Fredberg, professor of bioengineering and physiology at HSPH, and his colleague Xavier Trepat, a researcher at IBEC, are the only ones in the world that can now measure the forces within and between complex cellular groups. "We're beginning for the first time to see the forces and understand how they work when cells behave in large groups," said Trepat.

To do this, the researchers invented a measurement technology called Monolayer Stress Microscopy, which allows them to visualize the minute mechanical forces exerted at the junctions where individual cells are connected. Their studies led to discovery of a new phenomenon, which they named "plithotaxis," a term derived from Greek "plithos" suggestive of throng, swarm or crowd.

"If you studied a cell in isolation, you'd never be able to understand the behavior of a cell in a crowd," said Dhananjay Tambe, the first author and a research fellow at HSPH. Instead, the researchers studied groups of cells living in a single thin layer—a monolayer—and precisely measured the forces each cell was experiencing as it was navigating within the group. The findings surprised them.

"We thought that as cells are moving—say, to close a wound—that the underlying forces would be synchronized and smoothly changing so as to vary coherently across the crowd of cells, as in a minuet," said co-first author Corey Hardin, a research fellow at Massachusetts General Hospital. "Instead, we found the forces to vary tremendously, occurring in huge peaks and valleys across the monolayer. So the forces are not smooth and orderly at all; they are more like those in a 'mosh pit'—organized chaos with pushing and pulling in all directions at once, but collectively giving rise to motion in a given direction," he said.

"This new finding has the potential to alter, in a fundamental way, our understanding of mechano-biology and its role in the basic processes that underlie the function of monolayers in health and disease," said Fredberg. He also predicted the new report would be interesting for both physicists and biologists, and might even spur new research collaborations between the two disciplines.

The study findings should provide a better understanding of cell migration as it occurs in embryonic development—how the human body gets put together soon after fertilization, say the researchers. The findings may also help to explain how cancer cells migrate in the deadly process called metastasis.

Support for the study was provided by the European Research Council, the Spanish Ministry of Science and Innovation and the National Institutes of Health.

"Collective Cell Guidance by Cooperative Intercellular Forces," Dhananjay T. Tambe, C. Corey Hardin, Thomas E. Angelini, Kavitha Rajendran, Chan Young Park, Xavier Serra-Picamal, Enhua H. Zhou, Muhammad H. Zaman, James P. Butler, David A. Weitz, Jeffrey J. Fredberg, Xavier Trepat, Nature Materials, online May 22, 2011.

Visit the HSPH website for the latest news, press releases and multimedia offerings.

Harvard School of Public Health is dedicated to advancing the public's health through learning, discovery and communication. More than 400 faculty members are engaged in teaching and training the 1,000-plus student body in a broad spectrum of disciplines crucial to the health and well being of individuals and populations around the world. Programs and projects range from the molecular biology of AIDS vaccines to the epidemiology of cancer; from risk analysis to violence prevention; from maternal and children's health to quality of care measurement; from health care management to international health and human rights. For more information on the school visit www.hsph.harvard.edu.

Todd Datz | EurekAlert!
Further information:
http://www.hsph.harvard.edu

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

DGIST develops 20 times faster biosensor

24.04.2017 | Physics and Astronomy

Nanoimprinted hyperlens array: Paving the way for practical super-resolution imaging

24.04.2017 | Materials Sciences

Atomic-level motion may drive bacteria's ability to evade immune system defenses

24.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>