Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cells are crawling all over our bodies, but how?

19.10.2011
Biologists at Florida State devise new way to watch how cells move

For better and for worse, human health depends on a cell's motility –– the ability to crawl from place to place. In every human body, millions of cells –are crawling around doing mostly good deeds ––– though if any of those crawlers are cancerous, watch out.


This is an electron microscope image of two crawling worm sperm magnified ~5,000X. Credit: Courtesy, Tom Roberts, FSU Dept. of Biological Science

"This is not some horrible sci-fi movie come true but, instead, normal cells carrying out their daily duties," said Florida State University cell biologist Tom Roberts. For 35 years he has studied the mechanical and molecular means by which amorphous single cells purposefully propel themselves throughout the body in amoeboid-like fashion ––absent muscles, bones or brains.

Meanwhile, human cells don't give up their secrets easily. In the body, they use the millions of tiny filaments found on their front ends to push the front of their cytoskeletons forward. In rapid succession the cells then retract their rears in a smooth, coordinated extension-contraction manner that puts inchworms to shame. Yet take them out of the body and put them under a microscope and the crawling changes or stops.

But now Roberts and his research team have found a novel way around uncooperative human cells.

In a landmark study led by Roberts and conducted in large part by his then-FSU postdoctoral associate Katsuya Shimabukuro, researchers used worm sperm to replicate cell motility in vitro –– in this case, on a microscope slide.

Doing what no other scientists had ever successfully done before, Shimabukuro disassembled and reconstituted a worm sperm cell, then devised conditions to promote thecell's natural pull-push crawling motions even in the unnatural conditions of a laboratory. Once launched, the reconstituted machinery moved just like regular worm sperm do in a natural setting –– giving scientists an unprecedented opportunity to watch it move.

Roberts called his former postdoc's signal achievement "careful, clever work" –– and work it did, making possible new, revealing images of cell motility that should help to pinpoint with never-before-seen precision just how cells crawl.

"Understanding how cells crawl is a big deal," Roberts said. "The first line of defense against invading microorganisms, the remodeling of bones, healing wounds in the skin and reconnecting of neuronal circuits during regeneration of the nervous system –– all depend on the capacity of specialized cells to crawl.

"On the downside, the ability of tumor cells to crawl around is a contributing factor in the metastasis of malignancies," he said. "But we believe our achievements in this latest round of basic research could eventually aid in the development of therapies that target cell motility in order to interfere with or block the metastasis of cancer."

Funding for Robert's worm-sperm study came from the National Institutes of Health. The findings are described in a paper ("Reconstitution of Amoeboid Motility In Vitro Identifies a Motor-Independent Mechanism for Cell Body Retraction") published online in the journal Current Biology.

Why worm sperm?

For one thing, said Roberts, the worm sperm is different from most cells in that itdoesn't use molecular motor proteins to facilitate its contractions; it shimmies along strictly by putting together and tearing down its tiny filaments. And the simple worm sperm makes a good model because, while it is similar to a human cell it has fewer moving parts, making it less complicated to take apart and reassemble than, say, brain or cancer cells.

Armed with the newfound ability to reconstitute amoeboid motility in vitro, cell biologists such as Roberts may be able to learn the answers to some major moving questions. Among them: How can some cells continue to crawl even after researchers have disabled their supply of myosin, the force-producing "mover protein" that functions like a motor to help power muscle and cell contraction?

For Roberts and his team, the next move will be to determine if what they've learned about worm sperm also applies to more conventional crawling cells, including tumor cells.

"As always, there will be more questions," Roberts said. "Are there multiple mechanisms collaborating to drive cell body retraction? Is there redundancy built into the motility systems?"

Co-authors of the Current Biology paper include Roberts, a professor in the FSU Department of Biological Science; Shimabukuro, a former FSU postdoctoral associate in biology who now is a research scientist at the Japan Science and Technology Agency; Naoki Noda, of the Marine Biological Laboratory at Woods Hole, Mass.; and Murray Stewart, of the Medical Research Council's Laboratory of Molecular Biology in Cambridge, England.

Thomas A. Roberts | EurekAlert!
Further information:
http://www.fsu.edu

More articles from Life Sciences:

nachricht Nerves control the body’s bacterial community
26.09.2017 | Christian-Albrechts-Universität zu Kiel

nachricht Ageless ears? Elderly barn owls do not become hard of hearing
26.09.2017 | Carl von Ossietzky-Universität Oldenburg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: The fastest light-driven current source

Controlling electronic current is essential to modern electronics, as data and signals are transferred by streams of electrons which are controlled at high speed. Demands on transmission speeds are also increasing as technology develops. Scientists from the Chair of Laser Physics and the Chair of Applied Physics at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) have succeeded in switching on a current with a desired direction in graphene using a single laser pulse within a femtosecond ¬¬ – a femtosecond corresponds to the millionth part of a billionth of a second. This is more than a thousand times faster compared to the most efficient transistors today.

Graphene is up to the job

Im Focus: LaserTAB: More efficient and precise contacts thanks to human-robot collaboration

At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.

Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Nerves control the body’s bacterial community

26.09.2017 | Life Sciences

Four elements make 2-D optical platform

26.09.2017 | Physics and Astronomy

Goodbye, login. Hello, heart scan

26.09.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>