Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The mending tissue -- Cellular instructions for tissue repair

25.08.2015

NUS-led collaborative study identifies universal mechanism that explains how tissue shape regulates physiological processes such as wound healing and embryo development

A collaborative study led by scientists at the Mechanobiology Institute (MBI) at the National University of Singapore (NUS) has described a universal mechanism that regulates forces during epithelial tissue repair.


The researchers found that cells at the convex edge moved in faster than those at the concave edges. The image above depicts the shape used throughout the investigation which was chosen for its very large range of curvature (from highly convex to highly concave). The green structures protruding into the gap are the lamellipodia or the actin structures that are used in the cell crawling mechanism, while the white and magenta ring surrounding the gap shows the actomyosin cable used in the purse-string mechanism. The cell nuclei are represented in blue.

Credit: Mechanobiology Institute, National University of Singapore

This work, led by MBI co-Principal Investigator Professor Benoit Ladoux and conducted in collaboration with scientists from the Pierre et Marie Curie University, France; the Institute for Bioengineering of Catalonia, Spain; Chronic Disease Research Centre, Portugal, the Weizmann Institute, Israel; and the Cambridge University, UK, was published in prestigious scientific journal Nature Communications in July 2015.

How tissue shape regulates wound repair mechanisms

The epithelial tissue, or the epithelium, is one of four major types of tissue that lines the surfaces of all organs and hollow spaces in our body. The epithelium protects the organs from damage and maintains the body in a state of balance by allowing a selective in-and-out passage of substances. Proper function of the epithelium requires an intact layer of epithelial cells.

During the lifetime of an organism, gaps or holes of different sizes and shapes are introduced into this intact epithelium. They may appear as a consequence of natural biological processes such as embryo development when cells move around and rearrange to establish body patterns, or during cell turnover in adult tissues, when dead cells are cleared away by neighbouring healthy cells. In addition, injury or disease may also lead to wounds or ulcers in the tissue. In either case, any gap in the tissue needs to be sealed so that the normal functioning of the tissue is restored.

In the likelihood of an open wound or gap causing complications such as infections, inflammation or even cancer, our body has developed two major repair mechanisms whereby cells surrounding the gap collectively move in and seal the open spaces completely.

To do so, cells either put forth finger-like protrusions called lamellipodia to crawl along the underlying surface or form an interconnecting belt or cable of actin filaments and myosin proteins. When this cable contracts, it pulls the cells closer in a coordinated fashion, similar to the action of drawing a purse-string. However, the extent to which either mechanism contributes to tissue repair is known to depend on several factors such as the gap geometry, gap size or the presence or absence of an underlying supporting surface.

To determine the impact of tissue geometry on gap closure, the international research team studied the effects of gap shapes on gap closure mechanisms.

By using microfabrication techniques to grow epithelial cells around stencils made of an inert polymer, they created gaps of desired shapes within the cell culture. The boundaries of the gap were either protruding inwards (concave edges) or were extending away (convex edges).

Interestingly, the researchers noted that the speed at which cells along the gap edge moved depended on the local curvature. Specifically, they found that cells at the convex edge moved in faster than those at the concave edges. To test the relevance of their findings in a living system, the researchers studied wound repair in flies and found a similar association between wound shape and wound repair.

The current study has identified a universal mechanism that explains how the geometrical properties of tissue regulate forces and guide cellular movement during physiological processes such as cell turnover, embryo development and wound healing. Cells essentially receive the instructions on how to close a gap by sensing and measuring the shape of the gap itself. Further understanding of how cells do this will help researchers know how to treat chronic medical conditions involving wounds or unsealed gaps as well as designing new substrates to optimise tissue regeneration.

Media Contact

Amal Naquiah
amal@nus.edu.sg
65-651-65125

 @NUSingapore

http://www.nus.edu.sg/ 

Amal Naquiah | EurekAlert!

Further reports about: Cellular embryo development epithelial epithelial tissue epithelium gaps organs processes

More articles from Life Sciences:

nachricht Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides
16.07.2018 | Tokyo Institute of Technology

nachricht The secret sulfate code that lets the bad Tau in
16.07.2018 | American Society for Biochemistry and Molecular Biology

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides

16.07.2018 | Life Sciences

New research calculates capacity of North American forests to sequester carbon

16.07.2018 | Earth Sciences

Nano-kirigami: 'Paper-cut' provides model for 3D intelligent nanofabrication

16.07.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>