Recovery of mice raises hopes drug could help people with spinal injuries
Mice with spinal cord injuries have shown remarkable recovery after being given a drug initially developed for people with lung disease, researchers have revealed, saying the treatment could soon be tested on humans.
It is thought there are about 2,500 new spinal cord injuries in the UK every year, with some of those affected experiencing full loss of movement as a result. Despite a number of promising areas of research, at present damage to the spinal cord is not reversible.
Now researchers at the University of Birmingham say a drug called AZD1236, initially developed to treat chronic obstructive pulmonary disease in humans, has shown promise in mice with spinal cord compression injuries, a type of injury often associated with motor accidents in humans, but which is also linked to conditions such as osteoarthritis. A similar drug, called AZD3342, showed comparable benefits in rats.
The results, published in the journal Clinical and Translational Medicine, suggested the drugs block the action of enzymes known as MMP-9 and MMP-12 that rise after spinal cord injury. The upshot was that swelling of the spinal cord was reduced, levels of proteins linked to inflammation and pain were lowered, and breakdown of the bloodspinal cord barrier was limited. Scarring of connective tissue was also reduced.
The team said that compared with injured mice not given AZD1236, those given the drug for three days showed 85% improvement in movement and sensation six weeks after the spinal injury, while their nerve function was 80% of that seen in uninjured mice. Furthermore, the benefits were similar whether the drug was given immediately after spinal injury or 24 hours later.
“What we’re doing is we’re dampening down the damage to the nerve tissues. That way, we’re preserving more and more of the neurons,” said Prof Zubair Ahmed of the University of Birmingham, a co-author of the study.
Ahmed said the findings were exciting, adding that because AZD1236 had already been shown to be safe in humans, it could enter human trials sooner.
“Five to six years and this could be a potential treatment, if everything goes well,” he said.
Dr Mariel Purcell, a consultant in spinal injuries who was not involved in the work, welcomed the findings, although she cautioned that the results were, so far, limited to rodents and it was not yet clear whether similar benefits would be seen in humans.
“Spinal cord injury is a truly devastating life-altering injury with unfortunately little that can be done to limit the primary consequences of injury, such as paralysis and sensory impairment,” she said. “Translating this intervention into newly injured patients seems eminently practical, as the effect of AZD1236 is maintained, even if not administered until 24 hours post-injury, and the course of treatment is short at three days. It’s wonderful to see such exciting results.”