Restorative therapy in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is an adult onset neurodegenerative disorder characterized by the death of upper and lower motor neurons. About 10% of all ALS cases are familial; approximately 20% of familial ALS cases are caused by mutations in the superoxide dismutase 1 (SOD1) gene. We developed rats that express a human SOD1 transgene with ALS-associated mutations, developing striking motor neuron degeneration and paralysis. The larger size of this rat model as compared with the ALS mice, will facilitate studies involving manipulations of spinal fluid and the spinal cord. Hepatocyte growth factor (HGF) is one of the most potent survival-promoting factors for motor neurons. We administered human recombinant HGF (hrHGF) by continuous intrathecal delivery to the transgenic rats at the onset of paralysis for 4 weeks. Intrathecal administration of hrHGF attenuated motor neuron degeneration and prolonged the duration of the disease by 63%. To translate this strategy to human treatment, we induced a contusive cervical spinal cord injury in the common marmoset, a primate, and then administered hrHGF intrathecally. The intrathecal administration of hrHGF promoted functional recovery. These results prompted further clinical trials in ALS using continuous intrathecal administration of hrHGF.