Neuroprotective effect of hepatocyte growth factor

Hepatocyte growth factor (HGF), a natural ligand for the c-Met protooncogene product, exhibits mitogenic, motogenic, and morphogenic activities during regeneration of the liver, kidney, and lung. Recently, HGF was clearly shown to enhance neurite outgrowth in vitro. To determine whether HGF has a neuroprotective effect, i.e., prevents the death of neurons, in vivo, we studied the effect of HGF on delayed neuronal death in the hippocampus after 5 min transient forebrain ischemia in Mongolian gerbils. Continuous postischemic intrastriatal administration of human recombinant HGF (10 mu g or 30 mu g) for 7 days potently prevented the delayed death of hippocampal neurons under both anesthetized and awake conditions. Even when HGF infusion started 6 h after ischemia, i.e., in a delayed manner, HGF exhibited a neuroprotective effect. We conclude that HGF, a novel neurotrophic factor, has a profound neuroprotective effect against postischemic delayed neuronal death in the hippocampus, which may have implications for the development of new therapeutic strategies for ischemic neuronal damage in humans.