Researcher Regenerates Nerve Cells

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U Researcher Regenerates Nerve Cells

By Matt Groesbeck

Published: Wednesday, July 11, 2001

Through genetic tinkering, Maureen Condic can regenerate

nerve cells. This research may lead to improved treatments for

spinal and brain injuries.A University of Utah neuroscientist has

developed a way to spur adult nerve cells to regenerate, which

may lead to new treatments for debilitating brain and spinal-cord

injuries

..

Maureen Condic, researcher in the department of neurobiology

and anatomy at the U School of Medicine, said her study had a

different approach than other regeneration studies. Previous

researchers in this field altered the nerves' environment,

whereas Condic altered the properties of the nerve cells in an

effort to regenerate nerves in the adult central nervous system.

" We saw a huge improvement in the ability of adult neurons to

extend their axons, " Condic said.

An axon is the part of the nerve that transmits electrical signals

down to other nerves or tissue, said Condic. She explained

when the electrical signals are cut off, the nerve cells in the brain

and spinal cord, or central nervous system (CNS), don't

regenerate to fix themselves.

In contrast, peripheral nerves, those in other parts of the body,

can regrow after they're severed, an important attribute that

allows people with severed limbs the hope to regain motor and

sensory function, as was the case with the Florida boy whose

arm was reattached after a shark bit it off last weekend.

" The inability of adult CNS neurons to regenerate is believed to

be primarily attributable to the poor environment that the CNS

provides for neuronal growth, " Condic said in report published in

the July Journal of Neuroscience.

Most neuronal regeneration studies have manipulated factors in

the environment to try to influence neuron growth, Condic said.

To get into the neuron, Condic used an inactivated virus as a

vehicle to deliver the desired instructions. A virus is stripped of

its original genetic information, or " silenced, " and replaced with

the desired cargo. Through the silenced virus, Condic introduced

integrin into the nerve cell.

Integrin is to a nerve what tires are to a car, Condic said.

" It's as though you have a '57 Chevy on blocks in the front yard,

and it has all the necessary components except for its wheels. If

you give the wheels back, which are the car's usual way of

interacting with the environment, it's ready to go, " Condic said.

Condic believes increasing integrin levels can direct the neuron

to grab onto extracellular objects to propel its growth. By

increasing amounts of integrin, Condic increased the nerve-fiber

growth 10 times more than that in any other published study.

Regulating the amount of growth is the first challenge to

Condics' results.

" We don't want uncontrolled regeneration, " Condic said.

However, Condic said it is possible to control when the gene

goes on and off.

" The next step is critical, " Condic said. " I'm optimistic that at least

some of this will hold up in a more realistic animal model of

injury. "

Michele Lemons, a neuroscience post-doctoral fellow with

surgery expertise, and Condic's assistant, will continue Condic's

integrin expression research as it expands from the petri dish to

three dimensional animal models.

Animal studies will start in a few months as soon as Lemons

receives federal and local grants.

" I think this is really a profound set of experiments that [Condic]

has done…the extent of regrowth is so phenomenal that it

provides promise for future studies, " Lemons said.

Lemons anticipates many obstacles in researching animal

models, such as unknown environmental and anatomical

problems, not to mention the challenge of moving from a 2-D

petri dish to more complicated 3 D surgery.

Ultimately, Lemons envisions that the most successful result, in

terms of therapeutic benefits, may not be a single approach, but

the combination of other therapies as well.

" I think to get successful regeneration, it's going to be a

multi-faceted approach that includes a variety of therapies, "

Lemons said.

Condic believes that future studies will prove worthwhile based

on her initial findings. " This is all very theoretical, but it is not

imaginary, " Condic said. " This gives us a new tool, a new

weapon in our arsenal, with ultimate therapeutic effects…even

when I'm in my most cynical mode, I can see very few downsides

to this approach. "

According to Lemons, applicable results from Condic's lab won't

be known for at least two years.

mgroesbeck@...