Imagine driving your car along your typical commute, when suddenly you are in an accident.
Waking up in the hospital, you find out that your spinal cord was damaged.
Immediately, everyday tasks like walking, eating, and taking a shower become huge challenges.
Patients with spinal cord injuries can lose the ability to move their legs and upper extremities
and even lose their sense of touch.
But that’s not all: these patients often suffer from pain, ulcers, bowel issues, difficulty
breathing, depression and an overall reduced life expectancy.
A team of scientists and clinicians at Asterias Biotherapeutics is currently conducting a
clinical trial in patients with spinal cord injuries, with the goal of restoring some
of the lost motor function and sensation, and, as a result, improving the quality of
these patients’ lives.
Before we jump in, let’s understand what happens in spinal cord injury.
The spinal cord is a big bundle of nerves and supporting cells, including specialized
nerve cells called motor neurons, which are responsible for movement.
Nerves connect our brains to our bodies by carrying sensory and motor signals from the
brain, down the spinal cord, and to the muscles throughout the body.
The information is transmitted across large distances through a part of the neuron called
the axon, which acts like a wire.
Axons are protected by a material called myelin, which you can think of as the insulation around
the wire.
This insulation helps the nerve signals move rapidly down the spinal cord to the muscle
to allow for movement.
When the spinal cord is injured, two things can happen: 1) the nerve axons can get damaged,
blocking the nerves from sending important motor and sensory signals, and 2) the myelin
insulation can also break down, leaving the nerves exposed and unable to function normally.
The Asterias team has begun a human clinical trial to test a new experimental therapy - called
AST-OPC1 - to see if it can be effective in restoring function back to patients who have
suffered severe spinal cord injuries.
Because the major damage in these types of injuries is done to the nerves, and to their
protective myelin insulation, the scientists are tackling this first.
Their approach uses a cell type known as oligodendrocyte progenitor cells (OPCs).
These OPCs are made from human embryonic stem cells, which can become any type of cell in
the body.
The stem cell-derived OPCs are introduced directly into the spinal cord at the site
of the injury, where they can help repair damaged nerves and can produce more myelin
in the spinal cord.
This therapy is exciting because it utilizes a type of cell similar to one found naturally
in the body, and harnesses its normal function to reinsulate and repair the nerves damaged
in spinal cord injury.
With support from the introduced OPCs, damaged nerves at the sites of injury might recover
their functional abilities to conduct motor and sensory signals between the brain and
the hands, arms and fingers—and, hopefully, reverse some of the devastating paralysis
that affects many patients with spinal cord injuries.
By utilizing the latest stem cell based technologies, scientists are hoping to significantly improve
the quality of life of spinal cord injury patients and restore their ability to interact
with the world around them!
So far, Asterias’ animal studies, and their ongoing human clinical trial, have shown promising
results: safe implantation of the cells and as a result increased motor function.
But it is important to remember these results are early, and this stem cell based therapy
must be tested further.
With the successes we will celebrate, there will inevitably also be setbacks and obstacles
along the way.
However, even setbacks will provide learning opportunities for further scientific and medical
exploration that will bring us closer to curing or mitigating devastating conditions such
as severe spinal cord injury.
As we build on the progress enabled by California’s Proposition 71 and the funding agency it created,
the California Institute of Regenerative Medicine, we must keep the momentum going: we are now
at the point of seeing, for the first time, clinical research results in human patients
with devastating conditions such as severe spinal cord injury, and we can make even more
progress as we learn from these ongoing studies.
Only with continued support for biomedical research can we increase our understanding
of the therapeutic potential of stem cells and translate that understanding into meaningful
treatments that help give patients their lives back.