title: Diazoxide and cyclosporin A protect primary cholinergic neurons against beta-amyloid (1-42)-induced cytotoxicity.
abstract: OBJECTIVE
  Activation of mitochondrial (MitoKATP) channels was found to protect against anoxic and chemical stress in brain. This present study sought to investigate the ability of diazoxide and cyclosporin A to antagonize cytotoxicity induced by beta-amyloid peptide (A-beta1-42) in cultured rat primary basal forebrain cholinergic neurons.
  
  
  METHODS
  Cytotoxicity was induced by A-beta1-42 (2 μM) in the presence of either diazoxide (500 μM), a selective opener of the mitochondrial ATP-sensitive potassium channel (MitoKATP), or cyclosporin A (20 μM), an inhibitor of the mitochondrial permeability transition pore (MTP), or the combination of both the reagents. We determined cell morphology and cell viability using MTT assay and expression levels of anti-apoptotic protein (Bcl-2), pro-apoptotic proteins (Bax, cytochrome C, caspase-3 and cleaved caspase-3) using Western blotting at 24 hours and 72 hours.
  
  
  RESULTS
  Cell viability decreased markedly after exposure to A-beta1-42 for 72 hours with a decrease in the expression of Bcl-2 protein and cytochrome C and an increase in the caspase-3 and cleaved caspase-3 levels. Both diazoxide and cyclosporin A exerted significant protective effects on cell viability by ameliorating the decrease in Bcl-2 and the increase in cytochrome c and caspase-3 activity induced by A-beta1-42. The combination of both the reagents had a greater protective effect than either one alone.
  
  
  CONCLUSIONS
  The present research demonstrates that activation of MitoKATP channels independently or in combination with inhibitors of the MTP can elicit a protective effect against primary cholinergic neuron cytotoxicity induced by A-beta1-42. These findings suggest new mitochondrial targets for the development of therapeutic agents against A-beta-induced cytotoxicity.
authors.affiliation: Department of Neurosurgery, Affiliated Hospital of Weifang Medical University, Shandong, China.
authors.forename: Xianwei
authors.initials: X
authors.lastname: Zeng
authors.forename: Tony
authors.initials: T
authors.lastname: Wang
authors.forename: Liangliang
authors.initials: L
authors.lastname: Jiang
authors.forename: Guozhao
authors.initials: G
authors.lastname: Ma
authors.forename: Shuhui
authors.initials: S
authors.lastname: Tan
authors.forename: Jialong
authors.initials: J
authors.lastname: Li
authors.forename: Jianxin
authors.initials: J
authors.lastname: Gao
authors.forename: Kejing
authors.initials: K
authors.lastname: Liu
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D016229:Amyloid beta-Peptides / Q000037:antagonists & inhibitors* / Q000633:toxicity*; D000818:Animals; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism*; D002470:Cell Survival / Q000187:drug effects*; D059329:Cholinergic Neurons / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D016572:Cyclosporine / Q000494:pharmacology; D003981:Diazoxide / Q000494:pharmacology; D004357:Drug Synergism; D015870:Gene Expression / Q000187:drug effects; D033681:Mitochondrial Membrane Transport Proteins / Q000037:antagonists & inhibitors; D000083162:Mitochondrial Permeability Transition Pore; D018696:Neuroprotective Agents / Q000494:pharmacology*; D010446:Peptide Fragments / Q000037:antagonists & inhibitors* / Q000633:toxicity*; D015221:Potassium Channels / Q000819:agonists; D061251:Primary Cell Culture; D016548:Prosencephalon / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: D016229:Amyloid beta-Peptides; D051017:Apoptosis Regulatory Proteins; D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; D018696:Neuroprotective Agents; D010446:Peptide Fragments; D015221:Potassium Channels; C075222:amyloid beta-protein (1-42); D051028:bcl-2-Associated X Protein; C117780:mitochondrial K(ATP) channel; D016572:Cyclosporine; D003981:Diazoxide