title: Mitochondrial calcium response in human transformed lymphoblastoid cells.
abstract: Human lymphoblastoid cell line (LCL) transformed by Epstein-Barr Virus (EBV) is a unique cellular model for the study of human diseases. Although pathophysiological significance of mitochondrial calcium regulation is drawing attention, it is not known whether or not mitochondria in LCLs play a role in intracellular calcium signaling. In this study, role of mitochondria of the lymphoblastoid cell line in calcium signaling was examined. Intra-mitochondrial calcium concentration ([Ca2+]m) was successfully measured using dihydro-Rhod-2, revealed by the decrease of fluorescence after application of carbonyl cyanide m-chlorophenylhydrazone (CCCP) and intracellular localization patterns imaged by fluorescent microscope. Platelet activating factor (PAF) concentration-dependently increased cytosolic calcium concentration ([Ca2+]i), while no increase of [Ca2+]m was observed. In contrast, 10 microM thapsigargin increased [Ca2+]i as well as [Ca2+]m. LCLs may be used for the study of possible pathophysiological role of mitochondrial calcium regulation in human diseases.
authors.affiliation: Laboratory for Molecular Dynamics of Mental Disorders, Brain Science Institute, RIKEN, Hirosawa 2-1, Saitama, 351-0198, Wako, Japan. kato@brain..riken.go.jp
authors.forename: Tadafumi
authors.initials: T
authors.lastname: Kato
authors.forename: Mizuho
authors.initials: M
authors.lastname: Ishiwata
authors.forename: Takeharu
authors.initials: T
authors.lastname: Nagai
mesh_terms: D000328:Adult; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000502:physiology*; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D002461:Cell Line, Transformed; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D007476:Ionophores / Q000494:pharmacology; D008214:Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D008928:Mitochondria / Q000378:metabolism*; D010972:Platelet Activating Factor / Q000494:pharmacology; D019284:Thapsigargin / Q000494:pharmacology; D014475:Uncoupling Agents / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D007476:Ionophores; D010972:Platelet Activating Factor; D014475:Uncoupling Agents; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D019284:Thapsigargin; D002118:Calcium