title: Characterisation of Na(v) types endogenously expressed in human SH-SY5Y neuroblastoma cells.
abstract: The human neuroblastoma cell line SH-SY5Y is a potentially useful model for the identification and characterisation of Na(v) modulators, but little is known about the pharmacology of their endogenously expressed Na(v)s. The aim of this study was to determine the expression of endogenous Na(v) α and β subunits in SH-SY5Y cells using PCR and immunohistochemical approaches, and pharmacologically characterise the Na(v) isoforms endogenously expressed in this cell line using electrophysiological and fluorescence approaches. SH-SY5Y human neuroblastoma cells were found to endogenously express several Na(v) isoforms including Na(v)1.2 and Na(v)1.7. Activation of endogenously expressed Na(v)s with veratridine or the scorpion toxin OD1 caused membrane depolarisation and subsequent Ca(2+) influx through voltage-gated L- and N-type calcium channels, allowing Na(v) activation to be detected with membrane potential and fluorescent Ca(2) dyes. μ-Conotoxin TIIIA and ProTxII identified Na(v)1.2 and Na(v)1.7 as the major contributors of this response. The Na(v)1.7-selective scorpion toxin OD1 in combination with veratridine produced a Na(v)1.7-selective response, confirming that endogenously expressed human Na(v)1.7 in SH-SY5Y cells is functional and can be synergistically activated, providing a new assay format for ligand screening.
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, St Lucia, Australia.
authors.forename: Irina
authors.initials: I
authors.lastname: Vetter
authors.forename: Christine A
authors.initials: CA
authors.lastname: Mozar
authors.forename: Thomas
authors.initials: T
authors.lastname: Durek
authors.forename: Joshua S
authors.initials: JS
authors.lastname: Wingerd
authors.forename: Paul F
authors.initials: PF
authors.lastname: Alewood
authors.forename: Macdonald J
authors.initials: MJ
authors.lastname: Christie
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Lewis
mesh_terms: D045744:Cell Line, Tumor; D005453:Fluorescence; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D006801:Humans; D009447:Neuroblastoma / Q000201:enzymology*; D018408:Patch-Clamp Techniques; D020033:Protein Isoforms; D026941:Sodium Channel Blockers / Q000494:pharmacology; D015222:Sodium Channels / Q000145:classification* / Q000378:metabolism*; D013779:Tetrodotoxin / Q000494:pharmacology; D014701:Veratridine / Q000494:pharmacology
chemical_list: D020033:Protein Isoforms; D026941:Sodium Channel Blockers; D015222:Sodium Channels; D013779:Tetrodotoxin; D014701:Veratridine