title: [Possible effect of N-Acetyl-L-cysteine on Aβ(25-35)-induced tau hyperphosphorylation].
abstract: OBJECTIVE
  To investigate the possible effect and mechanism of N-Acetyl-L-cysteine (NAC) on fibrillar Aβ(25-35)-induced tau hyperphosphorylation.
  
  
  METHODS
  The phosphorylation of tau was induced by Aβ(25-35) in primary cortical neuron. Neurons were incubated in the absent or present Aβ(25-35), or pre-incubated NAC then co-incubated in Aβ. The measurement of ROS was performed on a microplate fluorometer. The proteins of p35/p25, cdk5, pT205 and pS404 were detected by Western blot.
  
  
  RESULTS
  In Aβ treated group, the ROS, pT205 and pS404 level were obviously higher than that in non-treated with Aβ group for 12 h (t=-6.35, P<0.05; t=-5, P<0.05; t=-4.57, P<0.05). However, in neurons pre-incubated with (10 mmol/L) NAC and then co-incubated with 20 µmol/L Aβ, the ROS, pT205 and pS404 level were significantly decreased compared with that of Aβ group (t=3.47, P<0.05; t=3.88, P<0.05 and t=3.64, P<0.05); Upon Aβ exposure for 12 h, cortical neurons showed a statistically significant increase in p25 when compared to the control group (t=-6.20, P<0.05). However, pre-treatment with NAC showed a decrease in p25 as compared to neurons treated with Aβ alone for 12 h (t=4.72, P<0.05).
  
  
  CONCLUSIONS
  NAC attenuated the Aβ(25-35)-induced tau hyperphosphorylation through CDK5 pathway.
authors.affiliation: Department of Neurology, Fujian Institute of Geriatrics, Fujian Medical University Union Hospital, Fuzhou 350001, China.
authors.forename: Tianwen
authors.initials: T
authors.lastname: Huang
authors.forename: Raoli
authors.initials: R
authors.lastname: He
authors.forename: Meng
authors.initials: M
authors.lastname: Zhou
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.forename: Zhiying
authors.initials: Z
authors.lastname: Lin
authors.forename: Qinyong
authors.initials: Q
authors.lastname: Ye
authors.affiliation: Email: chenxc998@163.com.
authors.forename: Xiaochun
authors.initials: X
authors.lastname: Chen
mesh_terms: D000111:Acetylcysteine; D016229:Amyloid beta-Peptides; D051360:Cyclin-Dependent Kinase 5; D009474:Neurons; D010446:Peptide Fragments; D010766:Phosphorylation; D016875:tau Proteins
chemical_list: D016229:Amyloid beta-Peptides; D010446:Peptide Fragments; C074636:amyloid beta-protein (25-35); D016875:tau Proteins; D051360:Cyclin-Dependent Kinase 5; C495905:CDK5 protein, human; D000111:Acetylcysteine