MicroRNA miR-133b is essential for functional recovery after spinal cord injury in adult zebrafish

MicroRNAs (miRNAs) are important for regulating gene expression during development and in adults. This study focuses on miR-133b's role in spinal cord regeneration in zebrafish, showing its upregulation in regenerating neurons after spinal cord transection. The study found that inhibiting miR-133b impaired locomotor recovery and reduced axon regeneration from specific brainstem neurons. miR-133b targets RhoA, which inhibits axonal growth, suggesting a mechanism for its regenerative effects. The findings indicate miR-133b is critical for spinal cord regeneration in zebrafish by reducing RhoA protein levels. This regulation of RhoA by a microRNA is a novel finding and may inform strategies for improving functional recovery after spinal cord injury in humans.

• 1
  miR-133b expression is upregulated in regenerating neurons of the brainstem after spinal cord transection in adult zebrafish.
• 2
  Inhibition of miR-133b expression impairs locomotor recovery and reduces regeneration of axons from neurons in the NMLF, SRF, and IMRF.
• 3
  miR-133b targets the small GTPase RhoA, an inhibitor of axonal growth, and reduces RhoA protein levels by direct interaction with its mRNA.