MicroRNA-124 protects against focal cerebral ischemia via mechanisms involving Usp14-dependent REST degradation

Acta Neuropathol. 2013 Aug;126(2):251-65. doi: 10.1007/s00401-013-1142-5. Epub 2013 Jun 11.

Abstract

MicroRNAs (miRNAs) are highly conserved non-coding RNAs modulating gene expression via mRNA binding. Recent work suggests an involvement of miRNAs in cardiovascular diseases including stroke. As such, the brain-abundant miR-124 and its transcriptional repressor RE1-silencing transcription factor (REST) do not only have elementary roles in the developing and the adult brain, but also alter expression upon cerebral ischemia. However, the therapeutic potential of miR-124 against stroke and the mechanisms involved remain elusive. Here, we analyzed the therapeutic potential of ectopic miR-124 against stroke and its underlying mechanisms with regard to the interaction between miR-124 and REST. Our results show that viral vector-mediated miR-124 delivery increased the resistance of cultured oxygen-glucose-deprived cortical neurons in vitro and reduced brain injury as well as functional impairment in mice submitted to middle cerebral artery occlusion. Likewise, miR-124 induced enhanced neurovascular remodeling leading to increased angioneurogenesis 8 weeks post-stroke. While REST abundance increased upon stroke, the increase was prevented by miR-124 despite a so far unknown negative feedback loop between miR-124 and REST. Rather, miR-124 decreased the expression of the deubiquitinating enzyme Usp14, which has two conserved miR-124-binding sites in the 3'UTR of its mRNA, and thereby mediated reduced REST levels. The down-regulation of REST by miR-124 was also mimicked by the Usp14 inhibitor IU-1, suggesting that miR-124 promotes neuronal survival under ischemic conditions via Usp14-dependent REST degradation. Ectopic miR-124 expression, therefore, appears as an attractive and novel tool in stroke treatment, mediating neuroprotection via a hitherto unknown mechanism that involves Usp14-dependent REST degradation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain Ischemia / genetics*
  • Brain Ischemia / metabolism
  • Brain Ischemia / pathology*
  • Calpain / metabolism
  • Cell Survival / physiology
  • Glucose / pharmacology
  • HEK293 Cells
  • Humans
  • Lipid Peroxidation / physiology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • MicroRNAs / physiology*
  • Neurons / pathology*
  • Neurons / physiology
  • Oxygen / pharmacology
  • Receptors, AMPA / metabolism
  • Repressor Proteins / metabolism*
  • Stroke / genetics
  • Stroke / metabolism
  • Stroke / pathology
  • Thiobarbituric Acid Reactive Substances / metabolism
  • Ubiquitin Thiolesterase / metabolism*
  • Ubiquitination / physiology

Substances

  • MicroRNAs
  • Mirn124 microRNA, mouse
  • RE1-silencing transcription factor
  • Receptors, AMPA
  • Repressor Proteins
  • Thiobarbituric Acid Reactive Substances
  • Usp14 protein, mouse
  • Ubiquitin Thiolesterase
  • Calpain
  • Glucose
  • glutamate receptor ionotropic, AMPA 2
  • Oxygen