Activation of muscarinic receptors inhibits glutamate-induced GSK-3β overactivation in PC12 cells
Abstract
Ke MA, Li-min YANG, Hong-zhuan CHEN, Yang LU*
Department of Pharmacy, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
Aim: To investigate the actions of the muscarinic agonist carbachol on glutamate-induced neurotoxicity in PC12 cells, and the underlying mechanisms.
Methods: PC12 cells were treated with different concentrations of glutamate for 24 or 48 h. The cell viability was measured using MTT assay, and the expression and activation of GSK-3β were detected with Western blot. β-Catenin translocation was detected using immunofluorescence. Luciferase reporter assay and real-time PCR were used to analyze the transcriptional activity of β-catenin.
Results: Glutamate (1, 3, and 10 mmol/L) induced PC12 cell death in a dose-dependent manner. Moreover, treatment of the cells with glutamate (1 mmol/L) caused significant overactivation of GSK-3β and prevented β-catenin translocation to the nucleus. Pretreatment with carbachol (0.01 μmol/L) blocked glutamate-induced cell death and GSK-3β overactivation, and markedly enhanced β-catenin transcriptional activity.
Conclusion: Activation of muscarinic receptors exerts neuroprotection in PC12 cells by attenuating glutamate-induced GSK-3β overactivation, suggesting potential benefits of muscarinic agonists for Alzheimer’s disease.
Keywords: muscarinic receptors; carbachol; neuroprotection; glutamate; excitotoxicity; GSK-3β; β-catenin; PC12 cell; Alzheimer’s disease
This work was supported by the National Natural Science Foundation of China (grant No 30873057 and 81171245) and the Key Basic Project of the Shanghai Municipal Science and Technology Commission, China (No 08JC1413600 and 11JC1406600).
* To whom correspondence should be addressed.
E-mail luyangssmu@yahoo.com
Received 2012-09-29 Accepted 2013-03-20
Keywords:
Department of Pharmacy, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
Aim: To investigate the actions of the muscarinic agonist carbachol on glutamate-induced neurotoxicity in PC12 cells, and the underlying mechanisms.
Methods: PC12 cells were treated with different concentrations of glutamate for 24 or 48 h. The cell viability was measured using MTT assay, and the expression and activation of GSK-3β were detected with Western blot. β-Catenin translocation was detected using immunofluorescence. Luciferase reporter assay and real-time PCR were used to analyze the transcriptional activity of β-catenin.
Results: Glutamate (1, 3, and 10 mmol/L) induced PC12 cell death in a dose-dependent manner. Moreover, treatment of the cells with glutamate (1 mmol/L) caused significant overactivation of GSK-3β and prevented β-catenin translocation to the nucleus. Pretreatment with carbachol (0.01 μmol/L) blocked glutamate-induced cell death and GSK-3β overactivation, and markedly enhanced β-catenin transcriptional activity.
Conclusion: Activation of muscarinic receptors exerts neuroprotection in PC12 cells by attenuating glutamate-induced GSK-3β overactivation, suggesting potential benefits of muscarinic agonists for Alzheimer’s disease.
Keywords: muscarinic receptors; carbachol; neuroprotection; glutamate; excitotoxicity; GSK-3β; β-catenin; PC12 cell; Alzheimer’s disease
This work was supported by the National Natural Science Foundation of China (grant No 30873057 and 81171245) and the Key Basic Project of the Shanghai Municipal Science and Technology Commission, China (No 08JC1413600 and 11JC1406600).
* To whom correspondence should be addressed.
E-mail luyangssmu@yahoo.com
Received 2012-09-29 Accepted 2013-03-20