Regenerative therapies for amyotrophic lateral sclerosis using hepatocyte growth factor

Amyotrophic lateral sclerosis (ALS) is an adult onset neurodegenerative disorder characterized by the death of upper and lower motor neurons. Approximately 20% of familial ALS cases are caused by mutations in the superoxide dismutase 1 (SOD1) gene. We have developed rats that express a human SOD1 transgene with two different ALS-associated mutations develop 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 (implantation of intrathecal catheters for chronic therapeutic studies; CSF sampling) and spinal cord (e.g., direct administration of viral- and cell-mediated therapies). Hepatocyte growth factor (HGF) is one of the most potent survival-promoting factors for motor neurons. To examine both its protective effect on motor neurons and its therapeutic potential, 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 attenuates motor neuron degeneration and prolonged the duration of the disease by 63%. Our results indicated the therapeutic efficacy of continuous intrathecal administration of hrHGF in ALS rats. These results should prompt further clinical trials in ALS using continuous intrathecal administration of hrHGF.