title: The specific Na(+)/Ca(2+) exchange inhibitor SEA0400 prevents nitric oxide-induced cytotoxicity in SH-SY5Y cells.
abstract: The Na(+)/Ca(2+) exchanger (NCX) plays a role in the regulation of intracellular Ca(2+) levels, and nitric oxide (NO) is involved in many pathological conditions including neurodegenerative disorders. We have previously found that sodium nitroprusside (SNP), an NO donor, causes apoptotic-like cell death in cultured glial cells via NCX-mediated pathways and the mechanism for NO-induced cytotoxicity is cell type-dependent. The present study examined using the specific NCX inhibitor 2-[4-[(2,5-difluorophenyl)methoxy]phenoxy]-5-ethoxyaniline (SEA0400) whether NCX is involved in NO-induced injury in cultured neuronal cells. The treatment of neuroblastoma SH-SY5Y cells with SNP resulted in apoptosis and the cytotoxicity was blocked by the mitogen-activated protein (MAP)/extracellular signal-regulated kinase (ERK) kinase inhibitor U0126 and the p38 MAP kinase (MAPK) inhibitor SB203580, but not by the c-Jun N-terminal kinase (JNK) inhibitor SP60012. SNP increased Ca(2+) influx and intracellular Ca(2+) levels. In addition, SNP increased ERK and p38 MAPK phosphorylation, and production of reactive oxygen species (ROS) in an extracellular Ca(2+)-dependent manner. These effects of SNP were prevented by SEA0400. SNP-induced cytotoxicity was not affected by inhibitors of the Ca(2+), Na(+) and store-operated/capacitative channels. Moreover, SNP-induced increase in intracellular Ca(2+) levels, ROS production and decrease in cell viability were blocked by a cGMP-dependent protein kinase (PKG) inhibitor. These results suggest that Ca(2+) influx via the reverse of NCX is involved in the cascade of NO-induced neuronal apoptosis and NO activates the NCX through guanylate cyclase/PKG pathway.
authors.affiliation: Laboratory of Medicinal Pharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, Japan.
authors.forename: Tetsuaki
authors.initials: T
authors.lastname: Nashida
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Takuma
authors.forename: Sayoko
authors.initials: S
authors.lastname: Fukuda
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Kawasaki
authors.forename: Teisuke
authors.initials: T
authors.lastname: Takahashi
authors.forename: Akemichi
authors.initials: A
authors.lastname: Baba
authors.forename: Yukio
authors.initials: Y
authors.lastname: Ago
authors.forename: Toshio
authors.initials: T
authors.lastname: Matsuda
mesh_terms: D000814:Aniline Compounds / Q000494:pharmacology*; D015153:Blotting, Western; D045744:Cell Line, Tumor; D004789:Enzyme Activation; D006801:Humans; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009569:Nitric Oxide / Q000502:physiology*; D010647:Phenyl Ethers / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D019831:Sodium-Calcium Exchanger / Q000037:antagonists & inhibitors*
chemical_list: D000814:Aniline Compounds; D010647:Phenyl Ethers; D017382:Reactive Oxygen Species; C430918:SEA 0400; D019831:Sodium-Calcium Exchanger; D009569:Nitric Oxide; D020928:Mitogen-Activated Protein Kinases