title: Unmodified calcium concentrations in tumour necrosis factor receptor subtype-mediated apoptotic cell death.
abstract: Tumour necrosis factor-alpha (TNF) receptors mediate a variety of effects dependent on cell type. A role for Ca2+ in TNF-induced death remains uncertain. Here we investigated restricting intracellular/extracellular Ca2+ in HeLa epithelial carcinoma cells expressing low and high levels of p75TNFR receptor subtype and KYM-1 rhabdomyosarcoma cells, models of rapid TNF-induced apoptosis. Ca2+ -chelators EGTA and BAPTA-AM as well as microsomal Ca2+ -ATPase inhibitor thapsigargin, did not alter TNF-induced death. TNF was also unable to alter resting [Ca2+]i levels which remained < 200 nM even during times when these cells were undergoing apoptotic cell death. These findings indicate no role for modulated Ca2+ concentrations in TNF-induced apoptotic cell death.
authors.affiliation: Department of Biomedical Sciences, Institute of Medical Sciences, University of Aberdeen, UK.
authors.forename: S M
authors.initials: SM
authors.lastname: McFarlane
authors.forename: H M
authors.initials: HM
authors.lastname: Anderson
authors.forename: S J
authors.initials: SJ
authors.lastname: Tucker
authors.forename: O J
authors.initials: OJ
authors.lastname: Jupp
authors.forename: D J
authors.initials: DJ
authors.lastname: MacEwan
mesh_terms: D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism*; D017209:Apoptosis / Q000502:physiology*; D002118:Calcium / Q000378:metabolism*; D002460:Cell Line; D002470:Cell Survival; D016257:Fura-2 / Q000031:analogs & derivatives* / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D015759:Ionomycin / Q000494:pharmacology; D007476:Ionophores / Q000494:pharmacology; D008856:Microscopy, Fluorescence; D018124:Receptors, Tumor Necrosis Factor / Q000235:genetics / Q000378:metabolism*; D047889:Receptors, Tumor Necrosis Factor, Type II; D012208:Rhabdomyosarcoma; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: D015703:Antigens, CD; D007476:Ionophores; D018124:Receptors, Tumor Necrosis Factor; D047889:Receptors, Tumor Necrosis Factor, Type II; D014409:Tumor Necrosis Factor-alpha; C049925:fura-2-am; D015759:Ionomycin; D002118:Calcium; D016257:Fura-2