Morphological and Functional Attenuation of Degeneration of Peripheral Neurons by Mesenchymal Stem Cell-Conditioned Medium in Spinocerebellar Ataxia Type 1-Knock-in Mice

CNS Neurosci Ther. 2016 Aug;22(8):670-6. doi: 10.1111/cns.12560. Epub 2016 May 3.

Abstract

Aims: Spinocerebellar ataxia type 1 (SCA1) is caused by the ataxin-1 protein (ATXN1) with an abnormally expanded polyglutamine tract and is characterized by progressive neurodegeneration. We previously showed that intrathecal injection of mesenchymal stem cells (MSCs) during the nonsymptomatic stage mitigates the degeneration of the peripheral nervous system (PNS) neurons in SCA1-knock-in (SCA1-KI) mice. We tested in this study whether the therapeutic effects of MSCs in SCA1-KI mice could be reproduced with MSC-releasing factor(s).

Methods: To test the effects of MSC-releasing factor(s), we used MSC-conditioned medium (MSC-CM). MSC-CM was intrathecally and/or intravenously injected into young SCA1-KI mice, and the therapeutic effects were assessed in the PNS at later ages using immunostaining, electrophysiology, and behavioral tests.

Results: MSC-CM attenuated the degeneration of axons and myelin of spinal motor neurons. Consequently, the injected SCA1-KI mice exhibited smaller reductions in nerve conduction velocity in spinal motor neurons and reduced motor incoordination than the untreated mice.

Conclusions: These results suggest that factors released from MSC mitigate the morphological and functional abnormalities in the PNS that are observed in SCA1-KI mice in a paracrine manner.

Keywords: Axon; Conditioned medium; Mesenchymal stem cell; Myelin; SCA1; Spinal motor neuron.

MeSH terms

  • Age Factors
  • Animals
  • Ataxin-1 / genetics*
  • Ataxin-1 / metabolism
  • Axons / drug effects
  • Axons / pathology
  • Cells, Cultured
  • Culture Media, Conditioned / pharmacology*
  • Disease Models, Animal
  • Evoked Potentials, Motor / physiology
  • Humans
  • Mesenchymal Stem Cells / chemistry*
  • Mesenchymal Stem Cells / physiology
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Motor Activity / drug effects
  • Motor Neurons / metabolism
  • Myelin Basic Protein / metabolism
  • Nerve Degeneration / drug therapy*
  • Nerve Degeneration / etiology*
  • Reaction Time / drug effects
  • Spinocerebellar Ataxias / complications*
  • Spinocerebellar Ataxias / genetics
  • Spinocerebellar Ataxias / metabolism
  • Tubulin / metabolism

Substances

  • ATXN1 protein, human
  • Ataxin-1
  • Culture Media, Conditioned
  • Myelin Basic Protein
  • Tubulin