Neuronal targeting of cardiotrophin-1 by coupling with tetanus toxin C fragment

Mol Cell Neurosci. 2001 May;17(5):842-54. doi: 10.1006/mcne.2001.0979.

Abstract

Cardiotrophin-1 (CT-1) is a potent neurotrophic factor for motoneurons but its clinical use in motor neuron diseases is precluded by side effects on the heart and liver. We explored the possibility of targeting CT-1 to neurons by coupling with the tetanus toxin fragment TTC. Genetic fusion proteins between CT-1 or GFP and TTC were produced in Escherichia coli and assayed in vitro. In contrast to uncoupled CT-1 or GFP, TTC-coupled proteins bound with high affinity to cerebral neurons and spinal cord motoneurons and were rapidly internalized. Glia, hepatocytes, or cardiomyocytes did not show detectable binding or uptake of TTC-coupled proteins. Similar to CT-1, TTC-coupled CT-1 induced IL-6 secretion by KB cells, activated Reg-2 gene expression, and promoted motoneuron survival in a dose-dependent manner. In vivo studies will test whether TTC-coupled CT-1 might be targeted to degenerating spinal cord or brain-stem motoneurons and migrate trans-synaptically to cortical motoneurons, which are also affected in amyotrophic lateral sclerosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain / cytology
  • Brain / drug effects
  • Brain / metabolism
  • Cell Survival / drug effects
  • Cell Survival / physiology
  • Cells, Cultured / cytology
  • Cells, Cultured / drug effects*
  • Cells, Cultured / metabolism
  • Cytokines / genetics
  • Cytokines / pharmacology*
  • Dose-Response Relationship, Drug
  • Escherichia coli / genetics
  • Fetus
  • Gene Expression / drug effects
  • Gene Expression / physiology
  • Green Fluorescent Proteins
  • Heart / drug effects
  • Heart / physiology
  • Hepatocytes / cytology
  • Hepatocytes / drug effects
  • Hepatocytes / metabolism
  • Humans
  • Interleukin-6 / genetics
  • Interleukin-6 / metabolism
  • Luminescent Proteins / analysis
  • Luminescent Proteins / genetics
  • Mice
  • Motor Neuron Disease / drug therapy*
  • Motor Neuron Disease / metabolism
  • Motor Neuron Disease / physiopathology
  • Motor Neurons / cytology
  • Motor Neurons / drug effects*
  • Motor Neurons / metabolism
  • Nerve Growth Factors / genetics
  • Nerve Growth Factors / pharmacology*
  • Peptide Fragments / genetics
  • Peptide Fragments / pharmacology*
  • Protein Engineering / methods
  • Recombinant Fusion Proteins / chemical synthesis
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / pharmacology*
  • Signal Transduction / drug effects
  • Signal Transduction / genetics
  • Spinal Cord / cytology
  • Spinal Cord / drug effects
  • Spinal Cord / metabolism
  • Tetanus Toxin / genetics
  • Tetanus Toxin / pharmacology*

Substances

  • Cytokines
  • Interleukin-6
  • Luminescent Proteins
  • Nerve Growth Factors
  • Peptide Fragments
  • Recombinant Fusion Proteins
  • Tetanus Toxin
  • tetanus toxin fragment C
  • Green Fluorescent Proteins
  • cardiotrophin 1