Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mouse study: New muscle-building agent beats all previous ones

09.12.2005


The Johns Hopkins scientists who first created "mighty mice" have developed, with pharmaceutical company Wyeth and the biotechnology firm MetaMorphix, an agent that’s more effective at increasing muscle mass in mice than a related potential treatment for muscular dystrophy now in clinical trials.



The new agent is a version of a cellular docking point for the muscle-limiting protein myostatin. In mice, just two weekly injections of the new agent triggered a 60 percent increase in muscle size, the researchers report in the Proceedings of the National Academy of Sciences, published online Dec. 5 and available publicly through the journal’s website.

The researchers’ original mighty mice, created by knocking out the gene that codes for myostatin, grew muscles twice as big as normal mice. An antibody against myostatin now in clinical trials caused mice to develop muscles 25 percent larger than those of untreated mice after five weeks or more of treatment.


The researchers’ expectation is that blocking myostatin might help maintain critical muscle strength in people whose muscles are wasting due to diseases like muscular dystrophy or side effects from cancer treatment or AIDS.

"This new inhibitor of myostatin, known as ACVR2B, is very potent and gives very dramatic effects in the mice," says Se-Jin Lee, M.D., Ph.D., a professor of molecular biology and genetics in Johns Hopkins’ Institute for Basic Biomedical Sciences. "Its effects were larger and faster than we’ve seen with any other agent, and they were even larger than we expected."

ACVR2B is the business end of a cellular docking point for the myostatin protein, and it probably works in part by mopping up myostatin so it can’t exert its muscle-inhibiting influence. But the researchers’ experiments also show that the new agent’s extra potency stems from its ability to block more than just myostatin, says Lee.

"We don’t know how many other muscle-limiting proteins there may be or which ones they are," says Lee, "but these experiments clearly show that myostatin is not the whole story."

The evidence for other players came from experiments with mighty mice themselves. Because these mice don’t have any myostatin, any effects of injecting the new agent would come from its effects on other proteins, explains Lee. After five injections over four weeks, mighty mice injected with the new agent had muscles 24 percent larger than their counterparts that didn’t get the new agent.

"In some ways this was supposed to be a control experiment," says Lee. "We weren’t really expecting to see an effect, let alone an effect that sizeable."

In other experiments with normal female mice, weekly injections of the new agent provided the biggest effect on muscle growth after just two weeks at the highest dose given (50 milligrams per kilogram mouse weight). Depending on the muscle group analyzed, the treated mice’s muscles were bigger than untreated mice by 39 percent (the gastrocnemius [calf] muscle) to 61 percent (the triceps).

After just one week, mice given a fifth of that highest dose had muscles 16 percent to 25 percent bigger than untreated mice, depending on the muscle group analyzed, and mice treated with one injection a week for two, three or four weeks continued to gain muscle mass.

But although the new agent seems quite promising, its advantage in potency also requires extra caution. "We don’t know what else the new agent is affecting or whether those effects will turn out to be entirely beneficial," says Lee.

Lee says they also are conducting experiments with the mice now to see whether the effect lasts after injections cease and whether it helps a mouse model of muscular dystrophy retain enough muscle strength to prolong life.

Joanna Downer | EurekAlert!
Further information:
http://www.jhmi.edu

More articles from Life Sciences:

nachricht Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery
20.01.2017 | GSI Helmholtzzentrum für Schwerionenforschung GmbH

nachricht Seeking structure with metagenome sequences
20.01.2017 | DOE/Joint Genome Institute

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

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>