Brief Report: Phenotypic Rescue of Induced Pluripotent Stem Cell-Derived Motoneurons of a Spinal Muscular Atrophy Patient§

Authors


  • Author contributions: T.C.: collection and assembly of data and data analysis and interpretation; W.Z. and S.B.: collection and assembly of data and data analysis; W.T.: conception and design and collection of data; H.H.: conception and design; R.L.: conception and design and data analysis and interpretation; J.Y.: conception and design, data analysis and interpretation, and manuscript writing.

  • Disclosure of potential conflicts of interest is found at the end of this article.

  • §

    First published online in STEM CELLSEXPRESS September 28, 2011.

Abstract

Spinal muscular atrophy (SMA) is one of the most common autosomal recessive disorders in humans and is a common genetic cause of infant mortality. The disease is caused by loss of the survival of motoneuron (SMN) protein, resulting in the degeneration of alpha motoneurons in spinal cord and muscular atrophy in the limbs and trunk. One function of SMN involves RNA splicing. It is unclear why a deficiency in a housekeeping function such as RNA splicing causes profound effects only on motoneurons but not on other cell types. One difficulty in studying SMA is the scarcity of patient's samples. The discovery that somatic cells can be reprogrammed to become induced pluripotent stem cell (iPSCs) raises the intriguing possibility of modeling human diseases in vitro. We reported the establishment of five iPSC lines from the fibroblasts of a type 1 SMA patient. Neuronal cultures derived from these SMA iPSC lines exhibited a reduced capacity to form motoneurons and an abnormality in neurite outgrowth. Ectopic SMN expression in these iPSC lines restored normal motoneuron differentiation and rescued the phenotype of delayed neurite outgrowth. These results suggest that the observed abnormalities are indeed caused by SMN deficiency and not by iPSC clonal variability. Further characterization of the cellular and functional deficits in motoneurons derived from these iPSCs may accelerate the exploration of the underlying mechanisms of SMA pathogenesis. STEM CELLS 2011;29:2090–2093.

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