Neurodevelopmental abnormalities in neurosphere-derived neural stem cells from SMN-depleted mice.
Spinal muscular atrophy (SMA) is a genetic disorder caused by depletion of survival motor neuron (SMN) protein and characterized by degeneration of alpha-motor neurons in the spinal cord. We investigated the morphology and differentiation of neurosphere-derived neural stem cells (NSCs) generated from the brains of a hypomorphic series of SMA mice. Neurospheres from the Smn(-/-);SMN2 mice, which represent a model of very severe SMA, produced NSCs with increased proliferation during growth and differentiation. These cells produced fewer Tuj1-positive neuronal cells, which displayed morphological alterations and had fewer and shorter neurites. The decrease in the number of Tuj1-positive cells was not a result of enhanced apoptosis but was accompanied by an increase in the number of nestin-positive cells. These results provide insight into the most severe model of SMA, in which SMN is nearly completely depleted, and suggest that SMN has a role in neurodevelopment as well as in neuromaintenance. Our work raises the possibility that SMN depletion affects neurodevelopment and neuromaintenance to varying extents, leading to SMA pathogenesis.
Shafey
Dina
D
Ottawa Health Research Institute, Ottawa, Ontario, Canada.
MacKenzie
Alex E
AE
Kothary
Rashmi
R
D000818:Animals; D017209:Apoptosis / Q000502:physiology; D015153:Blotting, Western; D002454:Cell Differentiation / Q000502:physiology*; D049109:Cell Proliferation; D005455:Fluorescent Antibody Technique; D020287:In Situ Nick-End Labeling; D051379:Mice; D008822:Mice, Transgenic; D009474:Neurons / Q000166:cytology* / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism; D055533:Survival of Motor Neuron 1 Protein / Q000235:genetics / Q000378:metabolism*
C526472:Smn1 protein, mouse; D055533:Survival of Motor Neuron 1 Protein