May 29, 2018

expert reaction to study attempting spinal cord repair in monkeys

A new study, published in PNAS, attempted spinal cord repair in monkeys.

Prof Catherina Becker, Professor for Neural Development and Regeneration, and the Deputy Director of the Centre for Discovery Brain Sciences, University of Edinburgh, said:

“In this exciting study, the authors follow up on their own previous research and that of others, by implantation of an anti-inflammatory and growth promoting scaffold containing NT3. This supports  some recovery of movement from a partial spinal lesion in macaque monkey, over the time frame of a year. Reconnection of regenerated axons to the far end of the spinal cord, essential for return of function, has been a major challenge in the field. The authors carefully tested that the improvement in function likely stemmed from the newly grown connections.

“One limitation is that intervention followed immediately after injury, which may not always be feasible in human patients. However, this study gives hope that long distance axonal regrowth and functional recovery may in the future be achieved also in human patients.”

Dr Dusko Ilic, Reader in Stem Cell Science, King’s College London, said:

“In this study, the Chinese scientists demonstrated on monkeys that neurotrophin 3-chitosan carriers submerged in collagen I gel and placed into a site of spinal cord injury were able to activate endogenous neural stem cells in the spinal cord. The activated neural stem cells induced formation of neural network, which interconnected sites of the injury and led to sensory and motor recovery.

“Although the data are quite robust, they are neither novel nor surprising. The similar concept was demonstrated in 2015 in a rat model. In some cases, animal models with a similar genetics and physiology to humans are required to assess safety and efficiency of novel therapeutic approaches, however, I really doubt that it was needed to use 38 monkeys in experiments to additionally prove this strategy of enhancing endogenous neurogenesis. Neither the type of the injury nor the therapeutic material had anything specific for primates. In addition, regulations for conducting first-in-man studies in patients with no therapeutic option are less rigorous and exclusive use of the monkey model would not be required to move this particular therapeutic approach to a clinical setting.”

* ‘NT3-chitosan enables de novo regeneration and functional recovery in monkeys after spinal cord injury’ by Jia-Sheng Rao et al. was published in PNAS on Monday 28 May 2018.  

Declared interests

Prof Catherina Becker: “I have no interests to declare.”

Dr Dusko Ilic: “I have no interest to declare.”