Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Heads or Tails: Cells' Electricity Decides

02.02.2011
For the first time, scientists have shown that specific changes in cell membrane voltage and ion flow are a key determinant in whether an organism regenerates a head or a tail. Biologists at Tufts University's School of Arts and Sciences were able to control the shape of tissue regenerated by amputated planarian (flatworm) segments by manipulating the natural electrical signals that determine head-tail identity in the worms.

The research, led by Tufts Professor of Biology Michael Levin, Ph.D., is reported in the Jan. 28, 2011, issue of the journal Chemistry & Biology, appearing online Jan. 27.

"This study has uncovered a previously unknown role for bioelectric signals in patterning tissues in flatworms, an important model system for understanding the basic mechanisms of regeneration," said Susan Haynes, Ph.D., who manages Levin's and other developmental biology grants at the National Institutes of Health. "The findings suggest that control of ion channels by pharmacological agents could be a useful approach in developing regenerative therapies for tissues and organs lost to injury or disease."

The Tufts study provides critical insights into how an injured organism determines that it has deviated from normal patterning and how it then restores the missing parts--providing precisely the amount and type of tissue necessary and avoiding overgrowth or cancer.

"Our and others’ previous research indicated that it is possible to trigger the process of regeneration by bioelectric means, but no one had yet shown that it is possible to actually determine what part regenerates by targeted changes in the function of ion channel and pump proteins that control transmembrane voltage potential," said Levin. "Once we understand this more fully, we hope to be able to induce human bodies to do the same."

Co-authors with Levin on the paper were three members of his laboratory: Wendy Scott Beane, Ph.D., post doctoral associate; Junji Morokuma, research associate; and Dany Spencer Adams, Ph.D., research associate professor.

Chemical Genetics
Importantly, the work demonstrates a technique for manipulating membrane voltage during regeneration that does not rely on gene therapy.

Such a drug-based "chemical genetics" approach avoids the need to regulate each signaling pathway and epigenetic mechanism individually and circumvents the difficulties of transgenes.

Flatworms have a complex central nervous system, a true brain and a well-defined adult stem cell population. They share a significant number of genes with vertebrates. The adult worms have remarkable powers of regeneration: any piece that is cut off will regrow, including the brain.

Two Heads Better than One?
The Tufts biologists had previously identified a possible role for the enzyme H,K-ATPase and cell-cell junctions in planarian regeneration. In the recent Chemistry and Biology paper, they report that H,K,-ATPase mediates ion transport to depolarize wounded tissue and enable planaria to regenerate heads.

Further, when the biologists used ivermectin independently of H,K,-ATPase to effect depolarization, the planarian fragments also regenerated new heads. This was true even for posterior wounds, which would normally regrow tails. The induction of the same tissue pattern by completely different means that have in common only their control of membrane voltage underscores the crucial nature of voltage gradient as a physiological parameter controlling regeneration.

The biologists also reported that treatment of wounded tissue with the H,K-ATPase inhibitor SCH 28080 for 72 hours hyperpolarized the tissue and stopped head regeneration.

The researchers concluded that pharmacologically induced changes in membrane voltage are enough to trigger an entire morphogenetic program -- head regeneration -- downstream of stem cell proliferation, and serve as a master regulator of a complex patterning cascade.

Unique Research Focus
Developmental biologists commonly study biochemical signals that cells exchange during the orchestration of the tissue regeneration process. The Levin lab is unique in focusing on an important and different kind of signal: a bioelectrical language that integrates the new cells' activity with the host to enable them to establish pattern during embryogenesis, fill in missing pieces during regeneration, and avoid the shape derangement observed in cancer throughout the lifespan.

Research funding was provided by the National Institutes of Health and the National Highway Traffic Safety Administration.

"A Chemical Genetics Approach Reveals H,K-ATPase-Mediated Membrane Voltage is Required for Planarian Head Regeneration," Chemistry & Biology, Jan. 28, 2011, Wendy Scott Beane; Junji Morokuma; Dany Spencer Adams; Michael Levin.

Tufts University, located on three Massachusetts campuses in Boston, Medford/Somerville, and Grafton, and in Talloires, France, is recognized among the premier research universities in the United States. Tufts enjoys a global reputation for academic excellence and for the preparation of students as leaders in a wide range of professions. A growing number of innovative teaching and research initiatives span all campuses, and collaboration among the faculty and students in the undergraduate, graduate and professional programs across the university is widely encouraged.

Kim Thurler | Newswise Science News
Further information:
http://www.tufts.edu

More articles from Life Sciences:

nachricht Not of Divided Mind
19.01.2017 | Hertie-Institut für klinische Hirnforschung (HIH)

nachricht CRISPR meets single-cell sequencing in new screening method
19.01.2017 | CeMM Forschungszentrum für Molekulare Medizin der Österreichischen Akademie der Wissenschaften

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland

19.01.2017 | Earth Sciences

Not of Divided Mind

19.01.2017 | Life Sciences

Molecule flash mob

19.01.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>