Scientists unlock secret of cellular communication

Last Updated: May 02, 2011, 00:00 AM IST

London: Most of the body`s cells communicate with one another by sending electrical signals through nano-thin membrane tubes.

A sensational Norwegian discovery may help to explain how cells cooperate to develop tissue in the embryo and how wounds heal.

For nearly 10 years, researchers have known that cells can "grow" ultra-thin tubes named tunnelling nanotubes (TNTs) between one another, the journal Proceedings of the National Academy of Sciences reports.

These nanotubes, two to three cells long and just 1/500th the thickness of a human hair, are connections that develop between nearly all cell types to form a communication channel different from any previously known mechanisms.

The breakthrough began with an experiment showing intercellular transmission of signals via nanotubes in 2007. The researchers then carried out similar trials with a number of other cell types, observing similar occurrences.

In 2010, Xiang Wang and Hans-Hermann Gerdes, colleagues at the University of Bergen`s Department of Biomedicine, Norway, discovered that electrical signals were being passed through nanotubes from one cell to another at one to two metres per second.

"We confirmed that this is a common phenomenon between cells," explains Prof Gerdes, according to a Bergen statement.

Intercellular nanotubes are far from permanent. Most of them last only a few minutes. This means the researchers cannot predict where and when the cells will form nanotube connections.

Wang quickly discovered that the mere presence of a nanotube was not sufficient to transmit an electrical signal. There had to be another mechanism involved as well.

Many cells form tiny membrane pores with each other called gap junctions which are made up of ring-shaped proteins.

"In other words," explains Gerdes, "there are two components: a nanotube and a gap junction. The nanotube grows out from one cell and connects to the other cell through a gap junction. Only then can the two cells be coupled electrically."

Nanotubes may also be a factor in explaining cell movement associated with wound healing, since cells move toward a wound in order to close it.

IANS