Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Swamping bad cells with good in ALS animal models helps sustain breathing

21.10.2008
Targeted cell delivery to the cervical spinal cord is a promising strategy to slow loss of motor neurons in ALS

In a disease like ALS - one that's always fatal and that has a long history of research-resistant biology - finding a proof of principle in animal models is significant.

This week, Johns Hopkins researchers report that transplanting a new line of stem cell-like cells into rat models of the disease clearly shifts key signs of neurodegenerative disease in general and ALS in particular - slowing the animals' neuron loss and extending life.

The new work supports the hypothesis that artificially outnumbering unhealthy cells with healthy ones in targeted parts of the spinal cord preserves limb strength and breathing and can increase survival.

An account of the work appears online this week in Nature Neuroscience.

Two parts of the study hold special interest: One is that the target area for the added cells - parts of the cervical spinal cord that control the diaphragm muscles largely responsible for breathing - reap the most benefit. Forty-seven percent more motor neurons survived there than in untreated model animals. Respiratory failure from diaphragm weakness is the usual cause of death in ALS, also called Lou Gehrig's disease.

"While the added cells, in the long run, didn't save all of the nerves to the diaphragm, they did maintain its nerve's ability to function and stave off death significantly longer," says neuroscientist Nicholas Maragakis, M.D., an associate professor of neurology at Johns Hopkins who led the research team.

"We intentionally targeted the motor neurons in this region," he says, "since we knew that, as in ALS, their death results in respiratory decline."

Also significant is that the transplanted cells, called glial restricted precursors (GRPs), address a well-known flaw in people with ALS and in its animal models. Both humans and models are stunted in their ability to clear away the neurotransmitter glutamate. And excess glutamate - common in ALS - overstimulates the motor neurons that spark muscle movement, causing death. The event, called excitotoxicity, also occurs in other neurological diseases.

So on a more basic level, the study adds clout to the principle - in live animals - that excitotoxicity is a major bad guy in ALS and that finding more effective ways to avoid or lessen it could help protect the nervous system.

In their research, the team transplanted some 900,000 glial restricted precursors overall to specific sites in the cervical spinal cord of each model rat in early stages of disease. The GRPs the scientists used began life as what's called astrocyte progenitor cells from healthy rat spinal cord tissue. Following transplant, they transformed into mature, healthy astrocytes, found living alongside sick motor neurons.

Astrocytes are the most common cells in the central nervous system. Work at Johns Hopkins and elsewhere has shown their crucial role in keeping the CNS in healthy balance. Not only are the cells studded with transporter molecules that mop up glutamate; they also maintain proper ion levels and nutrient support of nerve cells.

The study showed that at least a third of the added GRPs "took root" after their transplantation. With time, almost 90 percent of the GRPs had differentiated into astrocytes. Unlike the model rats' own astrocytes, the new ones continued to appear healthy. None of the GRPs damaged the spinal cord or formed tumors - a worry with some stem cell therapies.

Transplanting alternate GRPs - those that the team engineered to lack glutamate transporters - offered none of the protective properties.

"Our findings demonstrate that astrocyte replacement, by transplantation, is both possible and useful," Maragakis explains. "This targeted cell delivery to the cervical spinal cord is a promising strategy to slow that loss of motor neurons in ALS. We hope at some point that these principles will translate to the clinic."

Earlier research by U.S. scientists suggests that, while astrocytes go downhill in ALS, they may not be a primary cause of the disease. The idea is more that they're involved in its progression. Diseased astrocytes, studies show, may make motor neurons more susceptible to death by excitotoxicity.

Maryalice Yakutchik | EurekAlert!
Further information:
http://www.jhmi.edu
http://www.alscenter.org/

More articles from Life Sciences:

nachricht Closing the carbon loop
08.12.2016 | University of Pittsburgh

nachricht Newly discovered bacteria-binding protein in the intestine
08.12.2016 | University of Gothenburg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Closing the carbon loop

08.12.2016 | Life Sciences

Applicability of dynamic facilitation theory to binary hard disk systems

08.12.2016 | Physics and Astronomy

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D

08.12.2016 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>