title: Salidroside protects cortical neurons against glutamate-induced cytotoxicity by inhibiting autophagy.
abstract: Recent evidence suggests that glutamate-induced cytotoxicity contributes to autophagic neuron death and is partially mediated by increased oxidative stress. Salidroside has been demonstrated to have neuroprotective effects in glutamate-induced neuronal damage. The precise mechanism of its regulatory role in neuronal autophagy is, however, poorly understood. This study aimed to probe the effects and mechanisms of salidroside in glutamate-induced autophagy activation in cultured rat cortical neurons. Cell viability assay, Western blotting, coimmunoprecipitation, and small interfering RNA were performed to analyze autophagy activities during glutamate-evoked oxidative injury. We found that salidroside protected neonatal neurons from glutamate-induced apoptotic cell death. Salidroside significantly attenuated the LC3-II/LC3-I ratio and expression of Beclin-1, but increased (SQSTM1)/p62 expression under glutamate exposure. Pretreatment with 3-methyladenine (3-MA), an autophagy inhibitor, decreased LC3-II/LC3-I ratio, attenuated glutamate-induced cell injury, and mimicked some of the protective effects of salidroside against glutamate-induced cell injury. Molecular analysis demonstrated that salidroside inhibited cortical neuron autophagy in response to glutamate exposure through p53 signaling by increasing the accumulation of cytoplasmic p53. Salidroside inhibited the glutamate-induced dissociation of the Bcl-2-Beclin-1 complex with minor affects on the PI3K/Akt/mTOR signaling pathways. These data demonstrate that the inhibition of autophagy could be responsible for the neuroprotective effects of salidroside on glutamate-induced neuronal injury.
authors.affiliation: Department of Neurology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shanxi, China.
authors.forename: Wei-Yong
authors.initials: WY
authors.lastname: Yin
authors.affiliation: Department of Neurology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Ye
authors.affiliation: Department of Neurology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
authors.forename: Huan-Jie
authors.initials: HJ
authors.lastname: Huang
authors.affiliation: Department of Neurology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
authors.forename: Nian-Ge
authors.initials: NG
authors.lastname: Xia
authors.affiliation: Department of Neurology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
authors.forename: Yan-Yan
authors.initials: YY
authors.lastname: Chen
authors.affiliation: School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Neurology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shanxi, China. qqmxian@163.com.
authors.forename: Qiu-Min
authors.initials: QM
authors.lastname: Qu
mesh_terms: D000818:Animals; D001343:Autophagy / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D002540:Cerebral Cortex / Q000378:metabolism* / Q000473:pathology; D005960:Glucosides / Q000494:pharmacology*; D018698:Glutamic Acid / Q000633:toxicity*; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009474:Neurons / Q000378:metabolism* / Q000473:pathology; D010636:Phenols / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000187:drug effects*
chemical_list: D005960:Glucosides; D009419:Nerve Tissue Proteins; D010636:Phenols; D018698:Glutamic Acid; C009172:rhodioloside
keywords: Autophagy; Cortical neurons; Cytotoxicity; Neuronal injury; Salidroside