VEGF is a modifier of amyotrophic lateral sclerosis in mice and humans and protects motoneurons against ischemic death

Abstract
Amyotrophic lateral sclerosis (ALS) is an incurable degenerative disorder of motoneurons. We recently reported that reduced expression of Vegfa causes ALS-like motoneuron degeneration in Vegfaδ/δ mice. In a meta-analysis of over 900 individuals from Sweden and over 1,000 individuals from Belgium and England, we now report that subjects homozygous with respect to the haplotypes −2,578A/−1,154A/−634G or −2,578A/−1,154G/−634G in the VEGF promoter/leader sequence had a 1.8 times greater risk of ALS (P = 0.00004). These 'at-risk' haplotypes lowered circulating VEGF levels in vivo and reduced VEGF gene transcription, IRES-mediated VEGF expression and translation of a novel large-VEGF isoform (L-VEGF) in vivo. Moreover, SOD1G93A mice crossbred with Vegfaδ/δ mice died earlier due to more severe motoneuron degeneration. Vegfaδ/δ mice were unusually susceptible to persistent paralysis after spinal cord ischemia, and treatment with Vegfa protected mice against ischemic motoneuron death. These findings indicate that VEGF is a modifier of motoneuron degeneration in human ALS and unveil a therapeutic potential of Vegfa for stressed motoneurons in mice.