Repair of injured central nervous system may be possible

French researchers developed a procedure that halts the formation of scar tissue and could promote neuronal regeneration after nerve injury. The possibility of repairing voluntary motor activity brings hope to those with spinal cord injuries.

Recent studies have shown that when the spine is injured (or has a lesion), astrocytes (feeder cells of neurons) that normally envelop the neurons move to isolate damaged ones. The team of scientists from Inserm, led by Alain Privat, found that in doing so, the astrocytes “induces formation of impermeable cicatricial tissue around the neuron, thus constituting impenetrable scarring hostile to axonal regeneration and hence to propagation of nervous impulses. In the event of severe injury, the scarring engenders motor paralysis.” In response, French researchers from Inserm, the CNRS and the UPMC conducted in vitro studies using gene therapy to block the synthesis of tissue formation. Specifically, short interfering RNA was created and inserted into “the cytoplasm of cultured astrocytes using a viral therapeutic vector.” The RNA successfully blocked the synthesis of two astrocytes-created proteins responsible for tissue formation. In addition, the scientists were able to promote neuronal survival, triggering axonal growth. The study is published in the current issue of PLoS ONE. In vivo mouse studies are currently underway. If successful, the gene therapy could soon be available for those with spinal injuries.