Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cleaning up dead cell corpses: The phosphatidylserine receptor is not needed

24.08.2004

An article published today in Journal of Biology shows that the phosphatidylserine receptor, previously thought to be critical for the recognition and engulfment of dying cells, is not in fact necessary for these processes at all. Instead, the researchers found that the receptor is involved in the differentiation of a wide range of tissues during embryogenesis.

When cells undergo programmed cell death, they spill their normally hidden contents and their neighbours can thus recognise them as sick or dead and dispose of them accordingly. A particular recognition signal is provided by the normally internal phospholipid, phosphatidylserine, which dying cells expose on their surface.

Yet, Dr Andreas Lengeling and his colleagues from the German Research Center for Biotechnology found that the same patterns of cell death occurred during development in both wild-type (control) mice and mice lacking the phosphatidylserine receptor (Ptdsr). In addition, macrophages without Ptdsr, when studied in vitro, were just as efficient at ingesting dying cells as wild-type macrophages.

This evidence contradicts previous studies*, which concluded that mice with no Ptdsr are deficient at clearing up apoptosing cells, and consequently that the receptor is essential to this process. It is not yet clear precisely how the earlier studies led to such different conclusions about the role for the receptor, but one factor may be differences in the genetic background of the knockout mice that were studied by the various groups. In addition, Dr. Lengeling and his colleagues made more detailed studies in a wider range of tissue types than other researchers had previously carried out.

Dr Lengeling’s findings open up the possibility that another, as yet unknown, receptor exists that recognises phosphatidylserine on dying cells and promotes their ingestion. Alternatively, the engulfment of apoptosing cells may be mediated via phosphatidylserine-binding proteins and their receptors.

As dead and dying cells spill their otherwise internal contents, their rapid engulfment by neighbouring cells or professional phagocytes is needed to prevent the induction of autoimmune or inflammatory disorders. An accurate understanding of the molecular mechanisms behind the clearance of cell "corpses", and consequently what might go wrong with this process, could lead to the development of treatments for these disorders - and is important if money and time are not to be wasted creating ineffective remedies.

The experiments performed by Dr Lengeling and his team showed that rather than recognising apoptotic cells, Ptdsr may well be involved in stimulating macrophages to release pro-inflammatory cytokines. Most importantly, however, Ptdsr appears to promote the differentiation of lung, kidney, intestine and other organs. Mice with no Ptdsr died either prior to or shortly after birth, were growth retarded, and experienced delayed organ development. Some knockout mice had severely disturbed eye development.

Gemma Bradley | BioMed Central
Further information:
http://www.biomedcentral.com
http://jbiol.com
http://jbiol.com/content/3/4/15

More articles from Life Sciences:

nachricht The Secret of the Rock Drawings
24.05.2019 | Max-Planck-Institut für Chemie

nachricht Chemical juggling with three particles
24.05.2019 | Rheinische Friedrich-Wilhelms-Universität Bonn

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: New studies increase confidence in NASA's measure of Earth's temperature

A new assessment of NASA's record of global temperatures revealed that the agency's estimate of Earth's long-term temperature rise in recent decades is accurate to within less than a tenth of a degree Fahrenheit, providing confidence that past and future research is correctly capturing rising surface temperatures.

The most complete assessment ever of statistical uncertainty within the GISS Surface Temperature Analysis (GISTEMP) data product shows that the annual values...

Im Focus: The geometry of an electron determined for the first time

Physicists at the University of Basel are able to show for the first time how a single electron looks in an artificial atom. A newly developed method enables them to show the probability of an electron being present in a space. This allows improved control of electron spins, which could serve as the smallest information unit in a future quantum computer. The experiments were published in Physical Review Letters and the related theory in Physical Review B.

The spin of an electron is a promising candidate for use as the smallest information unit (qubit) of a quantum computer. Controlling and switching this spin or...

Im Focus: Self-repairing batteries

UTokyo engineers develop a way to create high-capacity long-life batteries

Engineers at the University of Tokyo continually pioneer new ways to improve battery technology. Professor Atsuo Yamada and his team recently developed a...

Im Focus: Quantum Cloud Computing with Self-Check

With a quantum coprocessor in the cloud, physicists from Innsbruck, Austria, open the door to the simulation of previously unsolvable problems in chemistry, materials research or high-energy physics. The research groups led by Rainer Blatt and Peter Zoller report in the journal Nature how they simulated particle physics phenomena on 20 quantum bits and how the quantum simulator self-verified the result for the first time.

Many scientists are currently working on investigating how quantum advantage can be exploited on hardware already available today. Three years ago, physicists...

Im Focus: Accelerating quantum technologies with materials processing at the atomic scale

'Quantum technologies' utilise the unique phenomena of quantum superposition and entanglement to encode and process information, with potentially profound benefits to a wide range of information technologies from communications to sensing and computing.

However a major challenge in developing these technologies is that the quantum phenomena are very fragile, and only a handful of physical systems have been...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

 
Latest News

On Mars, sands shift to a different drum

24.05.2019 | Physics and Astronomy

Piedmont Atlanta first in Georgia to offer new minimally invasive treatment for emphysema

24.05.2019 | Medical Engineering

Chemical juggling with three particles

24.05.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>