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 Brought to light – chromobodies reveal changes in endogenous protein concentration in living cells
21.09.2018 | NMI Naturwissenschaftliches und Medizinisches Institut an der Universität Tübingen

nachricht A one-way street for salt
21.09.2018 | Julius-Maximilians-Universität Würzburg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Scientists present new observations to understand the phase transition in quantum chromodynamics

The building blocks of matter in our universe were formed in the first 10 microseconds of its existence, according to the currently accepted scientific picture. After the Big Bang about 13.7 billion years ago, matter consisted mainly of quarks and gluons, two types of elementary particles whose interactions are governed by quantum chromodynamics (QCD), the theory of strong interaction. In the early universe, these particles moved (nearly) freely in a quark-gluon plasma.

This is a joint press release of University Muenster and Heidelberg as well as the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt.

Then, in a phase transition, they combined and formed hadrons, among them the building blocks of atomic nuclei, protons and neutrons. In the current issue of...

Im Focus: Patented nanostructure for solar cells: Rough optics, smooth surface

Thin-film solar cells made of crystalline silicon are inexpensive and achieve efficiencies of a good 14 percent. However, they could do even better if their shiny surfaces reflected less light. A team led by Prof. Christiane Becker from the Helmholtz-Zentrum Berlin (HZB) has now patented a sophisticated new solution to this problem.

"It is not enough simply to bring more light into the cell," says Christiane Becker. Such surface structures can even ultimately reduce the efficiency by...

Im Focus: New soft coral species discovered in Panama

A study in the journal Bulletin of Marine Science describes a new, blood-red species of octocoral found in Panama. The species in the genus Thesea was discovered in the threatened low-light reef environment on Hannibal Bank, 60 kilometers off mainland Pacific Panama, by researchers at the Smithsonian Tropical Research Institute in Panama (STRI) and the Centro de Investigación en Ciencias del Mar y Limnología (CIMAR) at the University of Costa Rica.

Scientists established the new species, Thesea dalioi, by comparing its physical traits, such as branch thickness and the bright red colony color, with the...

Im Focus: New devices based on rust could reduce excess heat in computers

Physicists explore long-distance information transmission in antiferromagnetic iron oxide

Scientists have succeeded in observing the first long-distance transfer of information in a magnetic group of materials known as antiferromagnets.

Im Focus: Finding Nemo's genes

An international team of researchers has mapped Nemo's genome

An international team of researchers has mapped Nemo's genome, providing the research community with an invaluable resource to decode the response of fish to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

"Boston calling": TU Berlin and the Weizenbaum Institute organize a conference in USA

21.09.2018 | Event News

One of the world’s most prominent strategic forums for global health held in Berlin in October 2018

03.09.2018 | Event News

4th Intelligent Materials - European Symposium on Intelligent Materials

27.08.2018 | Event News

 
Latest News

Astrophysicists measure precise rotation pattern of sun-like stars for the first time

21.09.2018 | Physics and Astronomy

Brought to light – chromobodies reveal changes in endogenous protein concentration in living cells

21.09.2018 | Life Sciences

"Boston calling": TU Berlin and the Weizenbaum Institute organize a conference in USA

21.09.2018 | Event News

VideoLinks
Science & Research
Overview of more VideoLinks >>>