title: Newly developed Mg2+-selective fluorescent probe enables visualization of Mg2+ dynamics in mitochondria.
abstract: Mg(2+) plays important roles in numerous cellular functions. Mitochondria take part in intracellular Mg(2+) regulation and the Mg(2+) concentration in mitochondria affects the synthesis of ATP. However, there are few methods to observe Mg(2+) in mitochondria in intact cells. Here, we have developed a novel Mg(2+)-selective fluorescent probe, KMG-301, that is functional in mitochondria. This probe changes its fluorescence properties solely depending on the Mg(2+) concentration in mitochondria under physiologically normal conditions. Simultaneous measurements using this probe together with a probe for cytosolic Mg(2+), KMG-104, enabled us to compare the dynamics of Mg(2+) in the cytosol and in mitochondria. With this method, carbonyl cyanide p-(trifluoromethoxy) phenylhydrazone (FCCP)-induced Mg(2+) mobilization from mitochondria to the cytosol was visualized. Although a FCCP-induced decrease in the Mg(2+) concentration in mitochondria and an increase in the cytosol were observed both in differentiated PC12 cells and in hippocampal neurons, the time-courses of concentration changes varied with cell type. Moreover, the relationship between mitochondrial Mg(2+) and Parkinson's disease was analyzed in a cellular model of Parkinson's disease by using the 1-methyl-4-phenylpyridinium ion (MPP(+)). A gradual decrease in the Mg(2+) concentration in mitochondria was observed in response to MPP(+) in differentiated PC12 cells. These results indicate that KMG-301 is useful for investigating Mg(2+) dynamics in mitochondria. All animal procedures to obtain neurons from Wistar rats were approved by the ethical committee of Keio University (permit number is 09106-(1)).
authors.affiliation: Center for Biosciences and Informatics, Graduate School of Science and Technology, Keio University, Yokohama, Kanagawa, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Shindo
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Fujii
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Komatsu
authors.forename: Daniel
authors.initials: D
authors.lastname: Citterio
authors.forename: Kohji
authors.initials: K
authors.lastname: Hotta
authors.forename: Koji
authors.initials: K
authors.lastname: Suzuki
authors.forename: Kotaro
authors.initials: K
authors.lastname: Oka
mesh_terms: D015655:1-Methyl-4-phenylpyridinium / Q000494:pharmacology; D000818:Animals; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone / Q000494:pharmacology; D027682:Cation Transport Proteins / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D003600:Cytosol / Q000737:chemistry / Q000378:metabolism; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006624:Hippocampus / Q000166:cytology; D017136:Ion Transport / Q000187:drug effects; D008274:Magnesium / Q000737:chemistry / Q000378:metabolism*; D018613:Microscopy, Confocal; D008928:Mitochondria / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism; D056004:Molecular Dynamics Simulation; D015394:Molecular Structure; D009474:Neurons / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D016716:PC12 Cells; D061209:Proton Ionophores / Q000494:pharmacology; D034741:RNA, Small Interfering / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D013050:Spectrometry, Fluorescence; D014162:Transfection
chemical_list: D027682:Cation Transport Proteins; D005456:Fluorescent Dyes; C556671:MRS2 protein, rat; D024101:Mitochondrial Proteins; D061209:Proton Ionophores; D034741:RNA, Small Interfering; D049452:Green Fluorescent Proteins; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone; D008274:Magnesium; D015655:1-Methyl-4-phenylpyridinium