Fasudil improves survival and promotes skeletal muscle development in a mouse model of spinal muscular atrophy

BMC Med. 2012 Mar 7;10:24. doi: 10.1186/1741-7015-10-24.

Abstract

Background: Spinal muscular atrophy (SMA) is the leading genetic cause of infant death. It is caused by mutations/deletions of the survival motor neuron 1 (SMN1) gene and is typified by the loss of spinal cord motor neurons, muscular atrophy, and in severe cases, death. The SMN protein is ubiquitously expressed and various cellular- and tissue-specific functions have been investigated to explain the specific motor neuron loss in SMA. We have previously shown that the RhoA/Rho kinase (ROCK) pathway is misregulated in cellular and animal SMA models, and that inhibition of ROCK with the chemical Y-27632 significantly increased the lifespan of a mouse model of SMA. In the present study, we evaluated the therapeutic potential of the clinically approved ROCK inhibitor fasudil.

Methods: Fasudil was administered by oral gavage from post-natal day 3 to 21 at a concentration of 30 mg/kg twice daily. The effects of fasudil on lifespan and SMA pathological hallmarks of the SMA mice were assessed and compared to vehicle-treated mice. For the Kaplan-Meier survival analysis, the log-rank test was used and survival curves were considered significantly different at P < 0.05. For the remaining analyses, the Student's two-tail t test for paired variables and one-way analysis of variance (ANOVA) were used to test for differences between samples and data were considered significantly different at P < 0.05.

Results: Fasudil significantly improves survival of SMA mice. This dramatic phenotypic improvement is not mediated by an up-regulation of Smn protein or via preservation of motor neurons. However, fasudil administration results in a significant increase in muscle fiber and postsynaptic endplate size, and restores normal expression of markers of skeletal muscle development, suggesting that the beneficial effects of fasudil could be muscle-specific.

Conclusions: Our work underscores the importance of muscle as a therapeutic target in SMA and highlights the beneficial potential of ROCK inhibitors as a therapeutic strategy for SMA and for other degenerative diseases characterized by muscular atrophy and postsynaptic immaturity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / administration & dosage
  • 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / analogs & derivatives*
  • 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / pharmacology
  • 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / therapeutic use
  • Animals
  • Anterior Horn Cells / drug effects
  • Anterior Horn Cells / pathology
  • Disease Models, Animal
  • Dose-Response Relationship, Drug
  • Gait / drug effects
  • Longevity / drug effects
  • Mice
  • Mice, Inbred C57BL
  • Motor Endplate / drug effects
  • Motor Endplate / pathology
  • Motor Endplate / physiopathology
  • Motor Neurons / drug effects
  • Motor Neurons / pathology
  • Muscle Development / drug effects*
  • Muscle Fibers, Skeletal / drug effects
  • Muscle Fibers, Skeletal / pathology
  • Muscle, Skeletal / drug effects
  • Muscle, Skeletal / growth & development*
  • Muscle, Skeletal / pathology
  • Muscle, Skeletal / physiopathology
  • Muscular Atrophy, Spinal / drug therapy*
  • Muscular Atrophy, Spinal / pathology
  • Muscular Atrophy, Spinal / physiopathology
  • Myogenin / metabolism
  • Phenotype
  • Spinal Cord / drug effects
  • Spinal Cord / pathology
  • Spinal Cord / physiopathology
  • Survival Analysis
  • Survival of Motor Neuron 2 Protein / deficiency
  • Survival of Motor Neuron 2 Protein / metabolism
  • Weight Gain / drug effects

Substances

  • Myogenin
  • Survival of Motor Neuron 2 Protein
  • 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine
  • fasudil