Voltage-sensitive and ligand-gated channels in differentiating neural stem-like cells derived from the nonhematopoietic fraction of human umbilical cord blood

Stem Cells. 2005 Aug;23(7):931-45. doi: 10.1634/stemcells.2004-0316.

Abstract

Fetal cells with the characteristics of neural stem cells (NSCs) can be derived from the nonhematopoietic fraction of human umbilical cord blood (HUCB), expanded as a nonimmortalized cell line (HUCB-NSC), and further differentiated into neuron-like cells (HUCB-NSCD); however, the functional and neuronal properties of these cells are poorly understood. To address this issue, we used whole-cell patch-clamp recordings, gene microarrays, and immunocytochemistry to identify voltage-gated channels and ligand-gated receptors on HUCB-NSCs and HUCB-NSCDs. Gene microarray analysis identified genes for voltage-dependent potassium and sodium channels and the neurotransmitter receptors acetylcholine (ACh), gamma-aminobutyric acid (GABA), glutamate, glycine, 5-hydroxytryptamine (5-HT), and dopamine (DA). Several of these genes (GABA-A, glycine and glutamate receptors, voltage-gated potassium channels, and voltage-gated sodium type XII alpha channels) were not expressed in the HUCB mono-nuclear fraction (HUCB-MC), which served as a starting cell population for HUCB-NSC. HUCB-NSCD acquired neuronal phenotypes and displayed an inward rectifying potassium current (Kir) and an outward rectifying potassium current (I(K+)). Kir was present on most HUCB-NSCs and HUCB-NSCDs, whereas I(K+) was present only on HUCB-NSCDs. Many HUCB-NSCDs were immunopositive for glutamate, glycine, nicotinic ACh, DA, 5-HT, and GABA receptors. Kainic acid (KA), a non-N-methyl-D-asparate (NMDA) glutamate-receptor agonist, induced an inward current in some HUCB-NSCDs. KA, glycine, DA, ACh, GABA, and 5-HT partially blocked Kir through their respective receptors. These results suggest that HUCB-NSCs differentiate toward neuron-like cells, with functional voltage- and ligand-gated channels identified in other neuronal systems.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Antigens, CD34 / biosynthesis
  • Cell Differentiation
  • Cell Line
  • Electrophysiology
  • Excitatory Amino Acid Antagonists / metabolism
  • Fetal Blood / cytology
  • Fetal Blood / metabolism*
  • Glycine / chemistry
  • Humans
  • Immunohistochemistry
  • Ions
  • Kainic Acid / metabolism
  • Leukocyte Common Antigens / biosynthesis
  • Ligands
  • N-Methylaspartate / metabolism
  • Neurons / metabolism*
  • Neurotransmitter Agents / metabolism
  • Oligonucleotide Array Sequence Analysis
  • Patch-Clamp Techniques
  • Phenotype
  • Potassium / chemistry
  • Receptors, GABA / metabolism
  • Receptors, Glutamate / metabolism
  • Sodium / chemistry
  • Stem Cells / cytology*
  • Stem Cells / metabolism
  • Umbilical Veins / metabolism

Substances

  • Antigens, CD34
  • Excitatory Amino Acid Antagonists
  • Ions
  • Ligands
  • Neurotransmitter Agents
  • Receptors, GABA
  • Receptors, Glutamate
  • N-Methylaspartate
  • Sodium
  • Leukocyte Common Antigens
  • Potassium
  • Kainic Acid
  • Glycine