The researcher who found a way to get
paralyzed rats back walking is now in Colorado and predicts huge breakthroughs
in treatment of human spinal cord injuries in half a decade.
"We've reached a stage where I'm
comfortable saying that within the next five years, we will have truly
effective new therapies from people with spinal cord injuries," Dr. Stephen
Davies said this week.
Talent scouts last year persuaded Dr.
Stephen Davies to leave his neurology lab at the Baylor School of Medicine in
Texas for the new Anschutz Medical Campus in Aurora, part of the University of
Colorado's Health Sciences Center.
Davies brought with him his methods of
regenerating damaged spinal cords by suppressing scar tissue and by injecting
special cells into the injury.
The two-pronged attack is being used on
rats right now, but he predicts there will be human trials within four or five
years.
First, he uses a naturally occurring
molecule, decorin, to suppress the scar tissue that forms when a spinal cord
has been badly bruised or severed.
By blocking the formation of scar
tissue, decorin helps the sensory nerve fibers cross the area of the spinal
cord injury and reconnect to viable nerves, said Davies, an associate
professor in CU's department of neurosurgery and head of the neuro-repair lab.
In rats, it took just four days, said
Davies, whose innovation won the American Spinal Injury Association's
Breakthrough Award in 2006.
His lab has the gene for the molecule
and is working with a biotech company to develop a pharmaceutical-grade
decorin that will be ready for the human trials.
Integra Life Sciences out of Piscataway,
N.J., is developing the decorin.
The decorin molecule could prove to be
helpful even for those people whose spinal cord injuries were five or more
years ago by breaking down the scar tissues that has blocked the nerves from
attempting to repair themselves.
Davies also has tapped into cells in the
human nervous system to help repair spinal cord injuries.
Astrocytes are the cells that make up 70
percent of the nervous system, even though they are not as well known as
neurons, he said.
Working with precursor cells, Davies and
his colleagues came up with a way to nudge the precursor cells into astrocytes
that have a particular knack for healing.
"They're able to promote robust
regeneration of nerve fibers across the injury," Davies said. In the rats, "40
percent of the sensory nerve fibers crossed the spinal cord injuries in eight
days when we put in the astrocytes."
Within 14 days, the rats were back to
their walking pace before their injuries. "We're very excited about the
potential of these cells," Davies said.
When the astrocytes are injected at the
point of injury, not only do they form a bridge, but they protect the cells in
the injured spinal cord from dying, Davies said. That allows the surviving
circuits to make new extra connections on their own.
"The idea is to combine the two
therapies," decorin and astrocytes, he said.
He is hoping the Department of Defense
will continue to show interest in the two therapies.
"If decorin turns out to be as promising
as we think it is, it may be included in a kit on the battlefield," Davies
said. Medics could administer decorin to prevent scarring from the early
moments of the spinal cord injury. "Early intervention is always the best."
Davies got his seed money from the
Christopher Reeve Paralysis Foundation, now called the Christopher and Dana
Reeve Foundation.
Davies expects to work with the
world-renowned Craig Rehabilitation Hospital in Englewood because physical
therapy is such an important complement to genetic and cell-based treatments
for patients.
Dr. Wise Young, a neuroscientist and
director of Rutgers University's W.M. Keck Center for Collaborative
Neuroscience, recently commented on Davies' work, saying, "This is going to
create a lot of excitement in the field," and will give a lot of impetus to
the push for human trials of spinal injury repair.
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