title: Voltage-sensitive and ligand-gated channels in differentiating neural stem-like cells derived from the nonhematopoietic fraction of human umbilical cord blood.
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.
authors.affiliation: Department of Pathology and Anatomical Sciences, 206A Farber Hall, SUNY University at Buffalo, Buffalo, New York 14214, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Sun
authors.forename: Leonora
authors.initials: L
authors.lastname: Buzanska
authors.forename: Krystyna
authors.initials: K
authors.lastname: Domanska-Janik
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Salvi
authors.forename: Michal K
authors.initials: MK
authors.lastname: Stachowiak
mesh_terms: D018952:Antigens, CD34 / Q000096:biosynthesis; D002454:Cell Differentiation; D002460:Cell Line; D004594:Electrophysiology; D018691:Excitatory Amino Acid Antagonists / Q000378:metabolism; D005312:Fetal Blood / Q000166:cytology / Q000378:metabolism*; D005998:Glycine / Q000737:chemistry; D006801:Humans; D007150:Immunohistochemistry; D007477:Ions; D007608:Kainic Acid / Q000378:metabolism; D017493:Leukocyte Common Antigens / Q000096:biosynthesis; D008024:Ligands; D016202:N-Methylaspartate / Q000378:metabolism; D009474:Neurons / Q000378:metabolism*; D018377:Neurotransmitter Agents / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D018408:Patch-Clamp Techniques; D010641:Phenotype; D011188:Potassium / Q000737:chemistry; D018079:Receptors, GABA / Q000378:metabolism; D017470:Receptors, Glutamate / Q000378:metabolism; D012964:Sodium / Q000737:chemistry; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism; D014471:Umbilical Veins / Q000378:metabolism
chemical_list: D018952:Antigens, CD34; D018691:Excitatory Amino Acid Antagonists; D007477:Ions; D008024:Ligands; D018377:Neurotransmitter Agents; D018079:Receptors, GABA; D017470:Receptors, Glutamate; D016202:N-Methylaspartate; D012964:Sodium; D017493:Leukocyte Common Antigens; D011188:Potassium; D007608:Kainic Acid; D005998:Glycine