Astrocytes control motor neuronal mitochondrial axonal transport deficits in C9ORF72 ALS.
Disrupted axonal transport and astrocyte dysfunction are implicated in amyotrophic lateral sclerosis (ALS). Here, we show these are intrinsically linked: human induced pluripotent stem cell-derived astrocytes carrying the C9ORF72 mutation disrupt axonal transport and mitochondrial function in motor neurons (MNs). Conversely, either isogenic gene-corrected astrocytes or selectively boosting C9ORF72-astrocyte mitochondrial bioenergetics rescue axonal transport deficits in C9ORF72-MNs. Thus, astrocytes have a dominant effect on axonal mitochondrial transport in the context of ALS.