Acute effects of hyperglycemia on the peripheral nervous system in zebrafish ( Danio Rerio) following nitroreductase-mediated β-cell ablation

Rocker, A., Howell, J., Voithofer, G., Clark, J.K.
American journal of physiology. Regulatory, integrative and comparative physiology   316(4): R395-R405 (Journal)
Registered Authors
hyperglycemia, motor axons, perineurium, sensory neurons, zebrafish
MeSH Terms
  • Animals
  • Animals, Genetically Modified
  • Basic Helix-Loop-Helix Transcription Factors/genetics
  • Basic Helix-Loop-Helix Transcription Factors/metabolism
  • Behavior, Animal/drug effects
  • Cell Count
  • Ganglia, Spinal/cytology
  • Ganglia, Spinal/metabolism
  • Homeodomain Proteins
  • Hyperglycemia/chemically induced
  • Hyperglycemia/physiopathology*
  • Hyperglycemia/psychology
  • Insulin-Secreting Cells/metabolism*
  • Larva
  • Metronidazole/pharmacology
  • Motor Neurons/drug effects
  • Motor Neurons/metabolism
  • Nerve Tissue Proteins/genetics
  • Nerve Tissue Proteins/metabolism
  • Nitroreductases/antagonists & inhibitors
  • Nitroreductases/metabolism*
  • Peripheral Nervous System/cytology
  • Peripheral Nervous System/physiopathology*
  • Schwann Cells/drug effects
  • Sensory Receptor Cells/metabolism
  • Zebrafish
  • Zebrafish Proteins
30726116 Full text @ Am. J. Physiol. Regul. Integr. Comp. Physiol.
Diabetic peripheral neuropathy (DPN) is estimated to affect 50% of diabetic patients. Although highly prevalent, molecular mechanisms remain unknown and treatment is limited to pain relief and glycemic control. Here, we provide a novel model of acute DPN in zebrafish (Danio Rerio)larvae. Beginning 5 days post fertilization (dpf), zebrafish expressing nitroreductase in their pancreatic b-cells were treated with metronidazole (MTZ) for 48 hours and checked for b-cell ablation 7 dpf. In experimental design, this was meant to serve as proof of concept that b-cell ablation and hyperglycemia was possible at this time-point, but surprisingly, we observed changes occurring to both sensory and motor nerve components. Compared to controls, neurod+ sensory neurons were often observed outside of the dorsal root ganglia in MTZ-treated fish. Fewer motor nerves were properly ensheathed by nkx2.2a+perineurial cells and tight junctions were disrupted along the motor nerve in MTZ-treated fish compared to controls. Not surprisingly, the motor axons of the MTZ-treated group were defasciculated compared to the control, myelination was attenuated and there was a subtle difference in Schwann cell number between MTZ-treated and control groups. All structural changes occurred in the absence of any behavioral changes in the larvae at this timepoint, suggesting that peripheral nerves are influenced by acute hyperglycemia prior to becoming symptomatic. Moving forward, this novel animal model of DPN will allow us to access the molecular mechanisms associated with the acute changes in the hyperglycemic peripheral nervous system, which may help direct therapeutic approaches.
Genes / Markers
Show all Figures
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Engineered Foreign Genes