Alcohol amplifies ketamine-induced apoptosis in primary cultured cortical neurons and PC12 cells through down-regulating CREB-related signaling pathways

Daiying Zuo,Yingliang Wu,Jiahui Cui,Zengqiang Li,Feng Sun,Yumiao Liu,Zi Liu,Xuejiao Zhou

doi:10.1038/s41598-017-10868-z

Daiying Zuo, Yingliang Wu + Show 6 more

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https://doi.org/10.1038/s41598-017-10868-z

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Journal: Scientific Reports	Publication Date: Sep 5, 2017
Citations: 20	License type: open-access

Affiliation: Shenyang Pharmaceutical University

Abstract

Recreational use of ketamine (KET) has been increasing worldwide. Previous studies have demonstrated that KET induced neurotoxicity; however, few studies have examined how alcohol (ALC) affects KET-induced neurotoxicity. In light of the fact that some KET abusers combine KET with ALC, the present study was aimed to investigate the effects of ALC on KET-induced neurotoxicity and the underlying mechanism in vitro. Our data revealed that co-treatment with ALC and KET was more detrimental to cell viability than KET single treatment in both PC12 cells and primary cultured rat cortical neurons. Furthermore, ALC exacerbated KET-induced apoptosis characterized by morphological changes and the sub-G1 phase increase, which were mitigated by the pretreatment of CNQX, a known alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA)/kainite (KA) receptor antagonist. In addition, ALC and KET co-treatment led to intracellular Ca2+ overload, down-regulation of p-Akt, p-CREB, PKA, CaMK-IV, Bcl-2 and BDNF expression and up-regulation of cleaved caspase-3 and Bax expression, which can be attenuated by CNQX pretreatment. These results indicate that the potentiation of ALC on KET-induced neurotoxicity was related to the down-regulation of CREB-related pathways. Our present study also indicates that ALC and KET co-abuse might cause serious neurotoxicity which should be conveyed to the public and drew enough attention.

Highlights

Glutamatergic receptors can be classified as ionotropic and metabotropic receptors
The pathways that are essential for cell survival such as the activation of Akt, protein kinase A (PKA), cyclic AMP-responsive element binding protein (CREB), brain-derived neurotrophic factor (BDNF) and apoptosis-related proteins, were further investigated to explore the underlying molecular mechanisms of ALC and KET-induced neurotoxicity in PC12 cells
The levels of reactive oxygen species (ROS) in PC12 cells were investigated by 2′,7′-dichlorodihydrofluorescein diacetate (DCFH-DA) staining

Summary

Introduction

Glutamatergic receptors can be classified as ionotropic (iGluRs) and metabotropic (mGluRs) receptors. KET is a mainstream recreational substance with increasing prevalence of illegal abuse, especially in adolescents[11]. There is evidence for mixed-drug abuse intoxications involving KET and ALC19, 20. In our opinion, further concerns should be considered regarding the combination of ALC and KET, as there is a possible risk of synergistic interaction between KET and ALC that may play a vital role in the mixed-drug intoxications, especially the neurotoxicity. The pathways that are essential for cell survival such as the activation of Akt (a serine/threonine kinase or protein kinase, PKB), protein kinase A (PKA), cyclic AMP-responsive element binding protein (CREB), brain-derived neurotrophic factor (BDNF) and apoptosis-related proteins, were further investigated to explore the underlying molecular mechanisms of ALC and KET-induced neurotoxicity in PC12 cells

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Conclusion