PUBLIC RELEASE DATE:

4-Apr-2014

Contact: Harry Dayantis h.dayantis@ucl.ac.uk 44-020-310-83844 University College London

A new way to artificially control muscles using light, with the potential to restore function to muscles paralysed by conditions such as motor neuron disease and spinal cord injury, has been developed by scientists at UCL and King's College London.

The technique involves transplanting specially-designed motor neurons created from stem cells into injured nerve branches. These motor neurons are designed to react to pulses of blue light, allowing scientists to fine-tune muscle control by adjusting the intensity, duration and frequency of the light pulses.

In the study, published this week in Science, the team demonstrated the method in mice in which the nerves that supply muscles in the hind legs were injured. They showed that the transplanted stem cell-derived motor neurons grew along the injured nerves to connect successfully with the paralyzed muscles, which could then be controlled by pulses of blue light.

"Following the new procedure, we saw previously paralysed leg muscles start to function," says Professor Linda Greensmith of the MRC Centre for Neuromuscular Diseases at UCL's Institute of Neurology, who co-led the study. "This strategy has significant advantages over existing techniques that use electricity to stimulate nerves, which can be painful and often results in rapid muscle fatigue. Moreover, if the existing motor neurons are lost due to injury or disease, electrical stimulation of nerves is rendered useless as these too are lost."

Muscles are normally controlled by motor neurons, specialized nerve cells within the brain and spinal cord. These neurons relay signals from the brain to muscles to bring about motor functions such as walking, standing and even breathing. However, motor neurons can become damaged in motor neuron disease or following spinal cord injuries, causing permanent loss of muscle function resulting in paralysis

"This new technique represents a means to restore the function of specific muscles following paralysing neurological injuries or disease," explains Professor Greensmith. "Within the next five years or so, we hope to undertake the steps that are necessary to take this ground-breaking approach into human trials, potentially to develop treatments for patients with motor neuron disease, many of whom eventually lose the ability to breathe, as their diaphragm muscles gradually become paralysed. We eventually hope to use our method to create a sort of optical pacemaker for the diaphragm to keep these patients breathing."

The light-responsive motor neurons that made the technique possible were created from stem cells by Dr Ivo Lieberam of the MRC Centre for Developmental Neurobiology, King's College London.

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Light-activated neurons from stem cells restore function to paralyzed muscles

Charlottesville, VA (PRWEB) April 04, 2014

Scientists at the University of Virginia School of Medicine have overcome one of the greatest challenges in biology and taken a major step toward being able to grow whole organs and tissues from stem cells. By manipulating the appropriate signaling, the UVA researchers have turned embryonic stem cells into a fish embryo, essentially controlling embryonic development.

The research will have dramatic impact on the future use of stem cells to better the human condition, providing a framework for future studies in the field of regenerative medicine aimed at constructing tissues and organs from populations of cultured pluripotent cells.

In accomplishing this, UVA scientists Bernard and Chris Thisse have overcome the most massive of biological barriers. We have generated an animal by just instructing embryonic cells the right way, said Chris Thisse, PhD, of the School of Medicines Department of Cell Biology.

The importance of that is profound. If we know how to instruct embryonic cells, she said, we can pretty much do what we want. For example, scientists will be able one day to instruct stem cells to grow into organs needed for transplant.

Directing Embryonic Development The researchers were able to identify the signals sufficient for starting the cascade of molecular and cellular processes that lead to a fully developed fish embryo. With this study came an answer to the longstanding question of how few signals can initiate the processes of development: amazingly, only two.

The study has shed light on the important roles these two signals play for the formation of organs and full development of a zebrafish embryo. Moreover, the Thisses are now able to direct embryonic development and formation of tissues and organs by controlling signal locations and concentrations.

The embryo they generated was smaller than a normal embryo, because they instructed a small pool of embryonic stem cells, but otherwise he has everything in terms of appropriate development, said Bernard Thisse, PhD, of the Department of Cell Biology.

Their next steps will be to attempt to reproduce their findings using mice. They expect molecular and cellular mechanisms will be extremely similar in mice and other mammals including humans.

Published in Science The findings have been published online by Science and will appear in a forthcoming print edition of the prestigious journal. The article was authored by UVAs Peng-Fei Xu, Nathalie Houssin, Karine F. Ferri-Lagneau, Bernard Thisse and Christine Thisse.

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UVA Smashes Barrier to Growing Organs from Stem Cells