title: Intracellular magnesium level determines cell viability in the MPP(+) model of Parkinson's disease.
abstract: Parkinson's disease (PD) is a neurodegenerative disorder resulting from mitochondrial dysfunction in dopaminergic neurons. Mitochondria are believed to be responsible for cellular Mg²⁺ homeostasis. Mg²⁺ is indispensable for maintaining ordinal cellular functions, hence perturbation of the cellular Mg²⁺ homeostasis may be responsible for the disorders of physiological functions and diseases including PD. However, the changes in intracellular Mg²⁺ concentration ([Mg²⁺]i) and the role of Mg²⁺ in PD have still been obscure. In this study, we investigated [Mg²⁺]i and its effect on neurodegeneration in the 1-methyl-4-phenylpyridinium (MPP⁺) model of PD in differentiated PC12 cells. Application of MPP⁺ induced an increase in [Mg²⁺]i immediately via two different pathways: Mg²⁺ release from mitochondria and Mg²⁺ influx across cell membrane, and the increased [Mg²⁺]i sustained for more than 16 h after MPP⁺ application. Suppression of Mg²⁺ influx decreased the viability of the cells exposed to MPP⁺. The cell viability correlated highly with [Mg²⁺]i. In the PC12 cells with suppressed Mg²⁺ influx, ATP concentration decreased and the amount of reactive oxygen species (ROS) increased after an 8h exposure to MPP⁺. Our results indicate that the increase in [Mg²⁺]i inhibited cellular ROS generation and maintained ATP production, which resulted in the protection from MPP⁺ toxicity.
authors: Department of Bioscience and Informatics, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan.
authors: Yutaka
authors: Y
authors: Shindo
authors: Department of Bioscience and Informatics, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan.
authors: Ryu
authors: R
authors: Yamanaka
authors: Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan.
authors: Koji
authors: K
authors: Suzuki
authors: Department of Bioscience and Informatics, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan.
authors: Kohji
authors: K
authors: Hotta
authors: Department of Bioscience and Informatics, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan. Electronic address: oka@bio.keio.ac.jp.
authors: Kotaro
authors: K
authors: Oka
mesh_terms: D015655:1-Methyl-4-phenylpyridinium / Q000633:toxicity*; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D008274:Magnesium / Q000378:metabolism*; D016716:PC12 Cells; D010300:Parkinson Disease / Q000378:metabolism*; D051381:Rats
chemical_list: D000255:Adenosine Triphosphate; D008274:Magnesium; D015655:1-Methyl-4-phenylpyridinium
keywords: ATP; Magnesium; Mitochondria; Neuroprotection; Parkinson's disease; Reactive oxygen species