Neuroscience researchers in Germany are working on a method for inserting “designer cytokines” to regenerate injured spinal cords. Of course, the research to date has been done on mice, but in some cases the treatment restored the ability to walk after only two to three weeks. This new therapy holds promise for reversing paraplegia.

After a spinal cord injury, the neurons in human spines do not naturally regenerate their axons, the long projections that carry nerve signals from the brain via the spinal cord to the muscles. In 2013, the German neuroscientists published a study showing that a particular immune signaling protein (or cytokine) called interleukin-6 (IL-6) could help to regenerate optic nerve axons in lab cultures. In effect, this facilitated the healing of nerve cells.

Trying to apply the same approach to spinal cord damage was a daunting project. But the scientists developed a technique that delivers a “designer” version of IL-6 deep into the central nervous system. That’s where the mice come in: testing this on mice with paraplegia as a result of severe spinal cord injury showed promising results.

The “designer” version of IL-6 was found to have a significant stimulatory effect on molecular regeneration. In the experiments on mice, a genetically engineered virus was inserted to provide genetic instructions for making hyper-IL-6 into motor neurons in an outer region of the brain called the sensorimotor cortex. 

The protein produced in this technique was then distributed via branching axons to more distant parts of the central nervous system that are essential for movement. 

One of the neuroscientists explained: “Gene therapy treatment of only a few nerve cells stimulated the axonal regeneration of various nerve cells in the brain and several motor tracts in the spinal cord spontaneously.” He further noted: “We are now breaking new scientific ground.  These further experiments will show, among other things, whether it will be possible to transfer these new approaches to humans in the future.”