title: Preconditioning-mediated neuroprotection: role of nitric oxide, cGMP, and new protein expression.
abstract: Preconditioning adaptation induced by transient ischemia can increase brain tolerance to oxidative stress, but the underlying neuroprotective mechanisms are not fully understood. Recently, we developed a human brain-derived cell model to investigate preconditioning mechanism in SH-SY5Y neuroblastoma cells.(1) Our results demonstrate that a non-lethal serum deprivation-stress for 2 h (preconditioning stress) enhanced the tolerance to a subsequent lethal oxidative stress (24 h serum deprivation) and also to 1-methyl-4-phenyl-pyridinium (MPP(+)).(2) Two-hour non-lethal preconditioning stress increased the expression of neuronal nitric oxide (NOS1/nNOS) mRNA, Fos, Ref-1, NOS protein, and then nitric oxide (*NO) production. As well as MnSOD expression, the *NO-cGMP-PKG pathway mediated the preconditioning-induced upregulation of antiapoptotic protein Bcl-2 and the downregulation of adaptor protein p66(shc). We also propose that cGMP-mediated preconditioning-induced adaptation against oxidative stress may be due to the synthesis of a new protein, such as thioredoxin (Trx) since the protective effect can be blocked by Trx reductase inhibitor.(3) The antioxidative potency of Trx was approximately 100 and 1,000 times greater than GSNO and GSH, respectively. These results suggest that *NO-cGMP-PKG signaling pathway plays an important role in the preconditioning-induced neuroprotection, and perhaps cardioprotection, against oxidative stress.
authors.affiliation: Department of Applied Pharmacology, Faculty of Pharmaceutical Sciences, Toyama Medical and Pharmaceutical University, 2630 Sugitani, Toyama, Japan. andoht@ms.toyama-mpu.ac.jp
authors.forename: Tsugunobu
authors.initials: T
authors.lastname: Andoh
authors.forename: P Boon
authors.initials: PB
authors.lastname: Chock
authors.forename: Chuang C
authors.initials: CC
authors.lastname: Chiueh
mesh_terms: D002490:Central Nervous System / Q000378:metabolism; D016895:Culture Media, Serum-Free; D006152:Cyclic GMP / Q000378:metabolism*; D006801:Humans; D009447:Neuroblastoma; D018696:Neuroprotective Agents / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000235:genetics / Q000378:metabolism; D052248:Nitric Oxide Synthase Type I; D018384:Oxidative Stress; D011506:Proteins / Q000378:metabolism*; D015398:Signal Transduction; D014407:Tumor Cells, Cultured
chemical_list: D016895:Culture Media, Serum-Free; D018696:Neuroprotective Agents; D011506:Proteins; D009569:Nitric Oxide; C496320:NOS1 protein, human; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; D006152:Cyclic GMP