The adaptation is made possible by a feedback mechanism

Nov 17, 2011 11:52 GMT  ·  By
Cells receive external signals (depicted in yellow) through sensing molecules — or receptors — (depicted in aqua) embedded in the cell membrane
   Cells receive external signals (depicted in yellow) through sensing molecules — or receptors — (depicted in aqua) embedded in the cell membrane

Cells communicate with their environments through chemical signals, which they release in specific patterns and concentrations. A new study shows that the mechanism works both ways, and that cells can adjust the volume of their chemical output accordingly.

Before this investigation, researchers were convinced that cells were only able to release chemical stimuli of a specified intensity. In other words, the fact that each cell responds to stimuli with an energy directly proportional to the intensity of that stimuli was unknown.

In addition, researchers from the Massachusetts Institute of Technology (MIT), in Cambridge, found out that each cell also has a feedback mechanism, which enables it to figure out whether the chemical message it sent out was received. This works like a delivery confirmation notice.

When this return signal is very low, cells can automatically increase the power of their message, by increasing the concentration of chemicals it releases. The process as a whole is very adaptable, and changes depending on each situation.

The reason why such research is critically-important is because chemical signals released through the membranes are responsible for controlling the majority of basic cell functions, without which no lifeform could survive.

Chemical signaling also plays important roles in genetic expression – by determining which genes are turned on or off, and when – as well as in organizing the internal cellular structure, and triggering a programmed cell death mechanism called apoptosis.

But apoptosis is suppressed in cancer cells, so it's easy to understand in how many ways the new study could be useful for doctors. If experts learn to control the strength of the signaling molecule output each cell has, then it may be possible to derive new treatments for a wide variety of disorders.

“Signaling cascades are often portrayed as unidirectional. [But MIT experts] provide a convincing proof of their earlier theory,” explains research scientist Stanislav Shvartsman, who was not a part of the new investigation.

“The results of their beautifully designed and carefully executed experiments profoundly influence our understanding of signal transduction in cellular networks,” he adds. Shvartsman holds an appoitnemtn as a professor of chemical and biological engineering at the Princeton University.

The MIT team was led by the Keck Career Development Associate Professor in Biomedical Engineering at the Institute, Domitilla Del Vecchio. Details of the study were published in the October issue of the esteemed journal Science Signaling.