In a collaboration between the University’s Veterinary School and MRC’s Regenerative Medicine Centre, scientists used a unique type of cell to regenerate the damaged part of the dogs’ spines. The researchers are cautiously optimistic that the work could have a future role in the treatment of human patients with similar injuries if used alongside other treatments.
Scientists have been aware for over a decade that olfactory ensheathing cells (OEC) might be useful in treating the damaged spinal cord because of their unique properties. The cells have the ability to support nerve fibre growth that maintains a pathway between the nose and the brain.
Previous research using laboratory animals has already revealed that OECs can aid regeneration of the parts of nerve cells that transmit signals (axons) so as to form a ‘bridge’ between damaged and undamaged spinal cord tissue. A Phase 1 trial in human patients with SCI established that the procedure is safe.
The study, published in the latest issue of the neurology journal Brain, is the first double-blinded randomised controlled trial to test the effectiveness of these transplants to improve function in ‘real-life’ spinal cord injury. The trial was performed on animals that had spontaneous and accidental injury rather than in the controlled environment of a laboratory, and some time after the injury occurred. This far more closely resembles the way in which the procedure might be used in human patients.
The 34 pet dogs had all suffered severe spinal cord injury. Twelve months or more after the injury, they were unable to use their back legs to walk and unable to feel pain in their hindquarters. Many of the dogs were dachshunds which are particularly prone to this type of injury. Dogs are also more likely to suffer from SCIs because the spinal cord may be damaged as a result of what in humans is the relatively minor condition of a slipped disc.
In the study, funded by the MRC, one group of dogs had olfactory ensheathing cells from the lining of their own nose injected into the injury site. The other group of dogs was injected with just the liquid in which the cells were transplanted. Neither the researchers nor the owners (nor the dogs!) knew which injection they were receiving.
The dogs were observed for adverse reactions for 24 hours before being returned to their owners. From then on, they were tested at one month intervals for neurological function and to have their gait analysed on a treadmill while being supported in a harness. In particular, the researchers analysed the dogs’ ability to co-ordinate movement of their front and back limbs.