NEW YORK (Reuters Health) - A bacterial enzyme that prunes scar tissue formed after spinal injury could help regrow severed nerves, research in rats suggests.
Researchers speculate that the enzyme could eventually be used with other experimental therapies to treat serious spinal cord injuries in humans.
In experiments with rats with crush-type spinal injuries, UK scientists found that the enzyme--called chondroitinase ABC--broke through cellular obstacles at the injury site and allowed some regrowth of severed nerve fibers. What's more, the treated animals recovered at least some normal walking abilities.
Elizabeth J. Bradbury, of King's College London, and her colleagues report the findings in the April 11th issue of Nature.
One of the obstacles to natural nerve regrowth after a severe spinal injury is the build-up of molecules at the injury site that inhibit nerve regeneration. Among these are chondroitin sulphate proteoglycan (CSPG) molecules. Certain bacteria harbor enzymes, including chondroitinase ABC, that can effectively "prune" CSPG molecules.
So Bradbury's team looked at whether infusions of the enzyme could trim back these molecular obstacles and clear a path for nerve regrowth in spine-injured rats. They found that the treatment did promote some nerve regeneration and improve injured animals' movement.
Chondroitinase ABC and other potential treatments that target CSPG molecules join other experimental therapies, such as nerve growth factors, that could eventually treat human spinal cord injuries, the researchers conclude.
The "molecular machete" chondroitinase ABC could indeed be used to help "clear the road" for nerve regeneration, according to an accompanying editorial.
Lars Olsen of the Karolinska Institute in Stockholm, Sweden, notes that no single experimental therapy has been shown to completely heal severe spinal injuries. Fortunately, he adds, many could potentially be combined.
"In the short term," Olsen writes, "the prognosis for people with complete spinal-cord injury remains grim. Yet, looking further into the future, we can perhaps allow ourselves to be a bit more optimistic."