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Researchers reported restoring bladder function in paralyzed adult rats using a new technique to promote the regeneration of nerve cells after severe spinal cord injury, according to The Journal of Neuroscience.
Prof Chris Mason, Professor of Regenerative Medicine Bioprocessing, UCL, said:
“It’s expecting far too much for highly complex medical conditions to be cured by a single wonder drug. This paper supports the need for a combination of living tissue and a protein to achieve significant improvement in nerve regeneration in rats. Combination therapies are highly challenging to develop, however, their benefit in medicine is beyond doubt – the highly successful HIV/AIDS triple drug cocktail is one such example. The Cleveland Clinic team now needs to commit to the long journey of developing their breakthrough discovery if one day it is to routinely improve the lives of spinal cord injury patients – a journey that is both costly and uncertain.”
Dr John Williams, Head of Neuroscience and Mental Health at the Wellcome Trust, said:
“This is a careful study that gives us some clues to how we might be able to restore nerve function, however the study was done in rats and the implications for people are not yet clear. This is one of a number of ways that one can approach restoration of bladder function in paralysed patients, but careful studies will be needed to optimise which of the technologies under investigation might be of most benefit to patients.”
Dr Elizabeth Bradbury, MRC Senior Research Fellow in Regenerative Medicine, King’s College London, said:
“This paper is extremely important and will be of significant interest to the public, since recovery of bladder function is rated as one of the highest priorities of spinal injured patients.
“Most paralysed patients can cope with the loss of movement in the legs but find the loss of genitourinary function (the dysfunction of the genital and urinary organs) severely debilitating and demoralising. Consequently, recovery of bladder, bowel and sexual function is almost always ranked higher in priority than the ability to walk again by spinal injured patients. This is often overlooked by the scientific community and is under researched and underfunded.
“This study describes an important breakthrough by Professor Jerry Silver at CASE Western Reserve, Ohio. In an elegant study they combined a number of experimental strategies to try and restore bladder function to adult rats with a spinal cord injury. The injury was made to the lower back, which leads to lower limb paralysis and loss of genitourinary function.
“First they transplanted strips of nerve tissue to bridge the gap in the spinal cord; these tissue bridges were then encased in a special glue which contained growth factors to support regrowing spinal nerves. Finally, they administered an enzyme (called chondroitinase ABC), which breaks down molecules that accumulate in high amounts around injured areas of tissue and which normally stop nerves from re-growing after an injury. This was administered to either side of the transplanted nerves and this allowed regenerating nerve fibres from one side of the injured spinal cord to grow through the transplant and back into the other side of the spinal cord, where they could make useful connections with spinal cord cells. With this therapy bladder function was restored to paralysed rats. The ability to control urination was greatly improved in rats that had the full combinatory treatment (i.e. nerve tissue grafts plus growth factor plus chondroitinase).
“There are a number of challenges before this therapy can be brought to the clinic. For example, we need to make the chondroitinase enzyme safe and stable and find a way of delivering it for long periods of time and in enough quantities to treat the much larger human spinal cord.
“Nevertheless this is a remarkable advance which offers great hope for the future of restoring bladder function to spinal injured patients and if these challenges can be met we could be reaching clinical trials within 3-5 years.”
Dr Dusko Ilic, Senior Lecturer in Stem Cell Science, King’s College London, said:
“Just to be clear, this research does not involve stem cells. In this well-conducted study, using all appropriate controls (7 groups, each group consisting of 16 rats), the authors were looking to improve the outcome of peripheral nerve autografts – where intercostal nerve segments were harvested from an animal and transplanted back into the vertebral column of the same animal at the site of injury. They used an enzyme (chondroitinase) to break down scar tissue and fibroblast growth factor (FGF) to promote survival and growth of the grafts.
“Research into bladder control does not get as much attention as it should, so this paper is interesting and important. However, whilst the strategy is promising it is far from application in humans yet. As the authors state in the last paragraph of the paper, there is still too much unknown.”
‘Nerve Regeneration Restores Supraspinal Control of Bladder Function after Complete Spinal Cord Injury’ by Lee et al., published in Journal of Neuroscience on Tuesday 25th June.