Progressive Motor Neuron Pathology and the Role of Astrocytes in a Human Stem Cell Model of VCP-Related ALS

Publication date: 30 May 2017
Source:Cell Reports, Volume 19, Issue 9
Author(s): Claire E. Hall, Zhi Yao, Minee Choi, Giulia E. Tyzack, Andrea Serio, Raphaelle Luisier, Jasmine Harley, Elisavet Preza, Charlie Arber, Sarah J. Crisp, P. Marc D. Watson, Dimitri M. Kullmann, Andrey Y. Abramov, Selina Wray, Russell Burley, Samantha H.Y. Loh, L. Miguel Martins, Molly M. Stevens, Nicholas M. Luscombe, Christopher R. Sibley, Andras Lakatos, Jernej Ule, Sonia Gandhi, Rickie Patani
Motor neurons (MNs) and astrocytes (ACs) are implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS), but their interaction and the sequence of molecular events leading to MN death remain unresolved. Here, we optimized directed differentiation of induced pluripotent stem cells (iPSCs) into highly enriched (> 85%) functional populations of spinal cord MNs and ACs. We identify significantly increased cytoplasmic TDP-43 and ER stress as primary pathogenic events in patient-specific valosin-containing protein (VCP)-mutant MNs, with secondary mitochondrial dysfunction and oxidative stress. Cumulatively, these cellular stresses result in synaptic pathology and cell death in VCP-mutant MNs. We additionally identify a cell-autonomous VCP-mutant AC survival phenotype, which is not attributable to the same molecular pathology occurring in VCP-mutant MNs. Finally, through iterative co-culture experiments, we uncover non-cell-autonomous effects of VCP-mutant ACs on both control and mutant MNs. This work elucidates molecular events and cellular interplay that could guide future therapeutic strategies in ALS.

Graphical abstract

Teaser

Hall et al. use iPSCs to examine the sequence of events by which motor neurons degenerate in a genetic form of ALS. They find that astrocytes, a type of supportive cell, also degenerate under these conditions. The ALS-causing mutation disrupts the ability of astrocytes to promote survival of motor neurons.


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