Gene therapy improves limb function following spinal cord injury

April 1, 2014

Delivering a single injection of a scar-busting gene therapy to the spinal cord of rats following injury promotes the survival of nerve cells and improves hind limb function within weeks, according to a study published April 2 in The Journal of Neuroscience. The findings suggest that, with more confirming research in animals and humans, gene therapy may hold the potential to one day treat people with spinal cord injuries.

The is the main channel through which information passes between the brain and the rest of the body. Most are caused by damage to the axons, the long extensions that use to send these messages. Once these injuries take place, scar tissue forms and prevents the damaged nerves from re-growing.

Previous animal studies show that one way to promote the growth of injured spinal nerve is to administer the enzyme chondroitinase ABC (ChABC), which digests scar-forming proteins, to the site of injury. However, because ChABC breaks down quickly, maintaining these beneficial effects for a long period of time requires invasive and repeated administration of the enzyme to the spinal cord. To get around this hurdle, in recent years, scientists began exploring gene therapy as a method to efficiently coax spinal cord cells to produce the enzyme.

In the current study, a group of researchers led by Elizabeth Bradbury, PhD, of King's College London used a single injection to deliver the ChABC gene therapy into the spinal cord of injured adult rats. The treatment not only led the spinal cord cells to produce and secrete ChABC in large quantities over areas spanning the injury epicenter, it helped to maintain the overall health of the damaged spinal cord and restored hind limb function in the animals within 12 weeks.

"These findings provide convincing evidence that gene therapy with chondroitinase not only encourages the sprouting of injured axons, but also imparts significant protection to nerve cells," said Mark Tuszynski, MD, PhD, who studies how nerve cells recover following injury at the University of California, San Diego, and was not involved in this study. "These are new and important findings that could lead to the development of testable therapies for spinal cord injury in people," he added.

Bradbury's team delivered the ChABC gene into the matrix of the spinal cord (the space between ). Twelve weeks later, the animals that received the therapy had more surviving spinal and fibers present through and around the scar compared with animals that did not receive the treatment. ChABC gene therapy also led to the recovery of hind limb function in the animals, allowing them to navigate the rungs of a horizontal ladder.

Additional analysis revealed that ChABC gene therapy changed the way that inflammatory cells in the region respond following injury. Normally, after injury, immune cells invade the spinal cord and cause destructive and irreparable tissue damage. However, ChABC decreased the presence of these cells and increased the presence of other immune cells called M2 macrophages that help to reduce inflammation and enhance tissue repair.

"This scar-busting therapy represents an important advance since it reveals a novel interaction between the supportive matrix and the following an injury," Bradbury said. The ability to treat large areas of the spinal cord for extended periods of time in animals "will be important for scaling up to the larger human spinal cord for future translation of this therapy to the clinic," she added.

Explore further: Research offers hope in new treatment for spinal cord injuries

Related Stories

Stem cell scarring aids recovery from spinal cord injury

October 31, 2013

In a new study, researchers at Karolinska Institutet in Sweden show that the scar tissue formed by stem cells after a spinal cord injury does not impair recovery; in fact, stem cell scarring confines the damage. The findings, ...

New findings on neurogenesis in the spinal cord

March 5, 2014

Research from Karolinska Institutet in Sweden suggests that the expression of the so called MYC gene is important and necessary for neurogenesis in the spinal cord. The findings are being published in the journal EMBO Reports.

Recommended for you

New insights on how cocaine changes the brain

November 25, 2015

The burst of energy and hyperactivity that comes with a cocaine high is a rather accurate reflection of what's going on in the brain of its users, finds a study published November 25 in Cell Reports. Through experiments conducted ...

Can physical exercise enhance long-term memory?

November 25, 2015

Exercise can enhance the development of new brain cells in the adult brain, a process called adult neurogenesis. These newborn brain cells play an important role in learning and memory. A new study has determined that mice ...

Umbilical cells help eye's neurons connect

November 24, 2015

Cells isolated from human umbilical cord tissue have been shown to produce molecules that help retinal neurons from the eyes of rats grow, connect and survive, according to Duke University researchers working with Janssen ...

Brain connections predict how well you can pay attention

November 24, 2015

During a 1959 television appearance, Jack Kerouac was asked how long it took him to write his novel On The Road. His response – three weeks – amazed the interviewer and ignited an enduring myth that the book was composed ...

No cable spaghetti in the brain

November 24, 2015

Our brain is a mysterious machine. Billions of nerve cells are connected such that they store information as efficiently as books are stored in a well-organized library. To this date, many details remain unclear, for instance ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.