Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How are cells held together?

09.09.2005


At the Institut Curie, the CNRS team of Yohanns Bellaïche has just discovered a new cellular component that participates in the organization of cells in the epithelium. This tissue, which forms a barrier between our body and the outside world, is an extremely coherent structure of myriad cells that fit together according to very precise rules. This cohesion holds together the tissues that compose the organs and controls the "comings and goings" of various substances between the outside world and our body.


When cellular adhesives come unstuck… One of the components of the exocyst has been inactivated in these cells. The two cellular adhesives – cadherin (pink) and _-catenin (blue) – are dispersed through the cytoplasm instead of being localized essentially at the membranes, to form the intercellular junction. © J. Langevin/Institut Curie



The Institut Curie CNRS researchers’ discovery sheds light on how cells "stick together", thereby ensuring the cohesion needed for proper bodily functioning, but also clarifies the problems that may arise if this cellular cohesion is impaired. When tumor cells no longer stick together, they can move around and invade other tissues. This leads to a risk of propagation via metastases, which complicates the treatment of cancer.
These results are published in the September 2005 issue of Developmental Cell.

The epithelium lines all the cavities of our body. Like a border, it separates inside from out: the skin isolates us from the outside world, epithelial cells lining the small intestine separate the intestinal cavity – the "lumen" – from the rest of the body. The epithelium also regulates "toing and froing" across the border, since its cells are polar – they have a sort of compass which tells them which way is out and which in:



- This polarity controls the point of adhesion between cells, which are held together by adhesion proteins. If cellular cohesion is impaired, epithelial integrity is altered and in certain cases this can have unfortunate consequences (see "When cells go walkabout").

- Epithelial cells are directional. They have a so-called brush border – the apical surface(1) – which optimizes surface exchange with the outside.

The epithelium, the body’s "border guard"

Cell polarity regulates the flow of information between inside and out, controls the passage of various substances (water, ions, nutrients…) between body compartments, and filters the molecules to be transported, into the blood vessels, for example.

The polarity of epithelial cells is in part maintained by a highly organized transport network which ensures that molecules are correctly directed to their "place of work" where they can perform their specific tasks. Polarity is also involved in the distribution of membrane receptors that regulate cell growth. Loss of polarity due to failure of one of the cellular adhesives – a-catenin – leads to the appearance of tumor cells whose growth is perturbed(2).

Trafficking of cellular adhesives

At the Institut Curie, Yohanns Bellaïche’s CNRS team(3) has just shown that one of the transporters of certain molecules to the cell membrane, the exocyst complex(4), plays a key role in the transport of one of the cellular adhesives, cadherin, to the junction with the adjacent cell. There, cadherin joins two other proteins(5) equally vital for cellular cohesion. Together, these adhesion proteins hold the cells together.

CNRS scientists at the Institut Curie have for the first time found evidence that the exocyst plays a part in maintaining the polarity of epithelial cells, which are essential for proper bodily functioning.

This discovery also casts light on the risks associated with loss of this function. When tumor cells lose their capacity to adhere to neighboring cells, they are able to move around and invade other tissues, leading to a risk of metastases. Clear understanding of the mechanisms of cellular adherence could enable the formation of metastases to be limited by maintaining the cohesion of tumor cells.

Catherine Goupillon | alfa
Further information:
http://www.developmentalcell.com/
http://www.curie.fr

More articles from Life Sciences:

nachricht Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University

nachricht How herpesviruses win the footrace against the immune system
26.05.2017 | Helmholtz-Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>