Although alpha-synuclein is generally thought to have a pathological role in Parkinson＇s disease, accumulative evidence exists that alpha-synuclein has a neuroprotective effect. The aim of this study was to evaluate ...Although alpha-synuclein is generally thought to have a pathological role in Parkinson＇s disease, accumulative evidence exists that alpha-synuclein has a neuroprotective effect. The aim of this study was to evaluate the effect of extracellular alpha-synuclein on dopaminergic cell survival. We assessed cell viability using the 3-（4,5-dimethyt-thiazol-2-yt）-2,5-diphenyltertazolium bromide （MTT） assay both in undifferentiated SH-SY5Y （SHSY） cells and neuronally-differentiated SH-SY5Y （ndSHSY） cells after 24 hour treatment with monomeric alpha-synuclein at various concentrations （0 [control], 50, 100 nmol/L, 1 IJmol/L）. To determine whether cell viability assessed by MTT assay was affected by cell proliferation, 5-bromo-2＇-deoxyuridine （BrdU） incorporation assay was per- formed. Level of both Akt and phosphorylated Akt was measured using western blot method in ndSHSY cells with or without 24 hour alpha-synuclein treatment. Cell viability was increased in ndSHSY cells at the nanomolar concentration of alpha-synuclein, but not in SHSY cells. Proportion of BrdU-positive ndSHSY cells was decreased in alpha-synuclein-treated group compared with control group. Level of phosphorylated Akt in alpha-synuclein-treated group was higher compared with the control group. Our study shows that extracellular alpha-synuclein at nanomolar concentra- tion benefits dopaminergic cell survival via Akt pathway.展开更多
The homogeneous electrocatalytic oxidation of hydrazine（HZ） has been studied by indigocarmine（IND） as a mediator at the surface of TiO_2 nanoparticles modified carbon paste electrode（TNMCPE）.Cyclic voltammetry w...The homogeneous electrocatalytic oxidation of hydrazine（HZ） has been studied by indigocarmine（IND） as a mediator at the surface of TiO_2 nanoparticles modified carbon paste electrode（TNMCPE）.Cyclic voltammetry was used to study the electrochemical behavior of IND at different scan rates.The voltammetric response of the modified electrode was linear against the concentration of HZ in the ranges of 3.0×l0^（-8）-7.0×10~6 mol/L with differential pulse voltammetry method.The detection limit（3σ） was determined as 27.3 nmol/L.To evaluate the applicability of the proposed method to real samples,the modified CPE was applied to the determination of HZ in water samples.展开更多
基金supported by the Seoul National University Hospital(SNUH)Research Fund,No.03-2010-0240
文摘Although alpha-synuclein is generally thought to have a pathological role in Parkinson＇s disease, accumulative evidence exists that alpha-synuclein has a neuroprotective effect. The aim of this study was to evaluate the effect of extracellular alpha-synuclein on dopaminergic cell survival. We assessed cell viability using the 3-（4,5-dimethyt-thiazol-2-yt）-2,5-diphenyltertazolium bromide （MTT） assay both in undifferentiated SH-SY5Y （SHSY） cells and neuronally-differentiated SH-SY5Y （ndSHSY） cells after 24 hour treatment with monomeric alpha-synuclein at various concentrations （0 [control], 50, 100 nmol/L, 1 IJmol/L）. To determine whether cell viability assessed by MTT assay was affected by cell proliferation, 5-bromo-2＇-deoxyuridine （BrdU） incorporation assay was per- formed. Level of both Akt and phosphorylated Akt was measured using western blot method in ndSHSY cells with or without 24 hour alpha-synuclein treatment. Cell viability was increased in ndSHSY cells at the nanomolar concentration of alpha-synuclein, but not in SHSY cells. Proportion of BrdU-positive ndSHSY cells was decreased in alpha-synuclein-treated group compared with control group. Level of phosphorylated Akt in alpha-synuclein-treated group was higher compared with the control group. Our study shows that extracellular alpha-synuclein at nanomolar concentra- tion benefits dopaminergic cell survival via Akt pathway.
文摘The homogeneous electrocatalytic oxidation of hydrazine（HZ） has been studied by indigocarmine（IND） as a mediator at the surface of TiO_2 nanoparticles modified carbon paste electrode（TNMCPE）.Cyclic voltammetry was used to study the electrochemical behavior of IND at different scan rates.The voltammetric response of the modified electrode was linear against the concentration of HZ in the ranges of 3.0×l0^（-8）-7.0×10~6 mol/L with differential pulse voltammetry method.The detection limit（3σ） was determined as 27.3 nmol/L.To evaluate the applicability of the proposed method to real samples,the modified CPE was applied to the determination of HZ in water samples.
