With help from the best tweezers in the world a team of researchers from
the University of Copenhagen has shed new light on a fundamental mechanism in all living cells that helps them explore their surroundings and even invade tissue
Date:
March 28, 2022
Source:
University of Copenhagen - Faculty of Science
Summary:
With help from the best tweezers in the world a team of researchers
has shed new light on a fundamental mechanism in all living
cells that helps them explore their surroundings and even invade
tissue. Their discovery could have implications for research into
cancer, neurological disorders and much else.
FULL STORY ==========================================================================
With help from the best tweezers in the world a team of researchers
from the University of Copenhagen has shed new light on a fundamental
mechanism in all living cells that helps them explore their surroundings
and even invade tissue.
Their discovery could have implications for research into cancer,
neurological disorders and much else.
========================================================================== Using octopus-like tentacles, a cell pushes toward its target, a
bacterium, like a predator tracking down its prey. The scene could be
playing out in a nature programme. Instead the pursuit is being observed
at the nano-scale through a microscope at the University of Copenhagen's
Niels Bohr Institute.
The microscope recording shows a human immune cell pursuing and then
devouring a bacterium.
With their new study, a team of Danish researchers has added to the
world's understanding of how cells use octopus-like tentacles called
filopodia to move around in our bodies. This discovery about how cells
move had never been addressed. The study is being published today in
the journal, Nature Communications.
"While the cell doesn't have eyes or a sense of smell, its surface
is equipped with ultra-slim filopodia that resemble entangled octopus tentacles. These filopodia help a cell move towards a bacterium, and at
the same time, act as sensory feelers that identify the bacterium as
a prey," explains Associate Professor Poul Martin Bendix, head of the laboratory for experimental biophysics at the Niels Bohr Institute.
The discovery is not that filopodia act as sensory devices -- which
was already well established -- but rather about how they can rotate
and behave mechanically, which helps a cell move, as when a cancer cell
invades new tissue.
"Obviously, our results are of interest to cancer researchers. Cancer
cells are noted for their being highly invasive. And, it is reasonable
to believe that they are especially dependent on the efficacy of their filopodia, in terms of examining their surroundings and facilitating
their spread. So, it's conceivable that by finding ways of inhibiting
the filopodia of cancer cells, cancer growth can be stalled," explains Associate Professor Poul Martin Bendix.
==========================================================================
For this reason, researchers from the Danish Cancer Society Research
Center are a part of the team behind the discovery. Among other things,
the cancer researchers are interested in whether switching off the
production of certain proteins can inhibit the transport mechanisms
which are important for the filopodia of cancer cells.
The cell's engine and cutting torch According to Poul Martin Bendix,
the mechanical function of filopodia can be compared to a rubber
band. Untwisted, a rubber band has no power. But if you twist it, it
contracts. This combination of twisting and contraction helps a cell
move directionally and makes the filopodia very flexible.
"They're able to bend -- twist, if you will -- in a way that allows them
to explore the entire space around the cell, and they can even penetrate tissues in their environment," says lead author, Natascha Leijnse.
The mechanism discovered by the Danish researchers appears to be found
in all living cells. Besides cancer cells, it is also relevant to study
the importance of filopodia in other types of cells, such as embryonic
stem cells and brain cells, which are highly dependent on filopodia for
their development.
========================================================================== Studying cells with the best tweezers in the world The project involved interdisciplinary collaboration at the Niels Bohr Institute, where
Associate Professor Amin Doostmohammadi, who heads a research group that simulates biologically active materials, contributed with the modelling
of filopodia behaviour.
"It is very interesting that Amin Doostmohammadi could simulate the
mechanical movements we witnessed through the microscope, completely independent of chemical and biological details," explains Poul Martin
Bendix.
The main reason that the team succeeded in being the first to
describe the mechanical behaviour of filopodia is that NBI has unique
equipment for this type of experiment, as well as skilled researchers
with tremendous experience working with optical tweezers. When an
object is extraordinarily small, holding onto it mechanically becomes impossible. However, it can be held and moved using a laser beam with
a wavelength carefully calibrated to the object being studied. This is
called an optical tweezers.
"At NBI, we have some of the world's best optical tweezers for
biomechanical studies. The experiments require the use of several optical tweezers and the simultaneous deployment of ultra-fine microscopy,"
explains Poul Martin Bendix.
Leading the study alongside Poul Martin Bendix and Assistant Professor
Natascha Leijnse was NBI Technical Scientist Younes Barooji. The article
on cell filopodia is published today in Nature Communications.
========================================================================== Story Source: Materials provided by University_of_Copenhagen_-_Faculty_of_Science. Note: Content may be
edited for style and length.
========================================================================== Journal Reference:
1. Natascha Leijnse, Younes Farhangi Barooji, Mohammad Reza Arastoo,
Stine
Lauritzen So/nder, Bram Verhagen, Lena Wullkopf, Janine Terra
Erler, Szabolcs Semsey, Jesper Nylandsted, Lene Broeng Oddershede,
Amin Doostmohammadi, Poul Martin Bendix. Filopodia rotate and
coil by actively generating twist in their actin shaft. Nature
Communications, 2022; 13 (1) DOI: 10.1038/s41467-022-28961-x ==========================================================================
Link to news story:
https://www.sciencedaily.com/releases/2022/03/220328090014.htm
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