Research articleKetamine-induced neurotoxicity blocked by N-Methyl-d-aspartate is mediated through activation of PKC/ERK pathway in developing hippocampal neurons
Introduction
Ketamine, a non-competitive N-methyl d-aspartate (NMDA) receptor antagonist, is widely used in pediatric clinical practice due to its potent anesthetic and safe hemodynamic and respiratory profile [[1], [2]]. However, there has been a growing concern about the safety of ketamine on the developing brain [3]. Increasing evidence showed that prolonged exposure to ketamine results in anesthetic neurotoxicity and long-term neurocognitive deficits [[4], [5], [6], [7]]. Rodent and monkey research confirmed that ketamine anesthesia during critical periods of brain development can induce neuronal apoptosis [[8], [9]]. These findings urge that caution with the use of ketamine in neonatal and pediatric anesthesia.
NMDA (N-methyl-d-aspartate) receptors are densely localized on neurons of most major brain areas and are physically connected to proteins involved in cell-signaling cascades [10]. NMDA receptor blockade can accelerate neuronal apoptotic death [11]. PKC and ERK participate in some important cellular activities mediated by NMDA (N-Methyl-d-aspartate) receptors [[12], [13]]. Ketamine is a non-competitive NMDA receptor antagonist. Therefore we hypothesized thattreatment neurons with NMDA alleviates ketamine-induced neurotoxicityby PKC/ERK pathway.
Cell cycle can be divided into 4 distinct phases: gap 1(G1) phase, DNA synthesis (S), second gap (G2) and mitosis (M) phases [14]. Postmitotic neurons are believed to arrest in the G0 state and unable to proliferate. For postmitotic neurons, neural cell cycle reentry is related to apoptotic cell death and neurodegenerative diseases [[15], [16], [17]]. Hippocampus plays important roles in the consolidation of information from short-term memory to long-term memory, and in spatial memory that enables navigation [[18], [19]]. In this study, we will explore effect of ketamine on hippocampus neurons and focus on cell cycle phases.
In the present study, we show that ketamine induces aberrant cycle cell re-entry and decreases cell viability in a dose- and time-dependent manner, resulting in neuroapoptosis. In addition, ketamine decreases phosphorylation of PKCγ and ERK1/2, and leads to neuroapoptosis. Furthermore, neuroapoptosis induced by ketamine are reversed by co-incubating neurons with NMDA. These data suggest that inhibition of PKC/ERK signaling pathway involved in ketamine-induced neurotoxicity in the developing brain, and neuroprotection conferred by NMDA against ketamine cytotoxicity is mediated through activation of PKC/ERK pathway.
Section snippets
Ethics statement
This study was performed in strict accordance with the recommendations in the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health. The Institutional Animal Care and Use Committee (IACUC) of the Hebei Medical University specifically approved this study under protocol. All of the animals were handled according to this approved protocol.
Primary neurons cultures
Sprague-Dawley rats, aged to postnatal 24 h and weighing 4.5–6.5 g, were sacrificed. The bilateral hippocampal tissues were
Ketamine inhibits cell viability in a dose and duration dependent manner
Primary hippocampal neurons exposed to concentration of ketamine ranging from 0.1 to 1000 μM for hours. The MTT assay revealed a dose-dependent decrease in cell viability (Fig. 2A). Neurons treated with low concentrations (0.1, 1, 10 μM) of ketamine had no effect on cell viability. High concentrations (100, 300, 1000 μM) of ketamine decreased cell viability significantly. In addition, prolonged exposure to high concentrations (100, 300, 1000 μM) of ketamine damaged cell viability, suggested
Discussion
Anesthetic-induced neurotoxicity is age-dependent [21]. A period of 3–5 days is the critical period for brain development. During this period, anesthetic exposure can delete millions of neurons from the developing brain. Therefore, we chose to use primary neurons that were cultured in vitro for 3 days to explore the effect of ketamine on neurotoxicity. Ketamine inhibits cell viability in a dose and duration dependent manner, further indicates that ketamine can cause neuronal cell death in the
Author contributions
Lining Huang designed experiments and supervised the study. Xuze Li, Rui Zhang, Ying Wang and Jiangli Wu performed experiments and analyzed data. Sufang Jiang prepared the manuscript. Wei Jin, Rongtian Kang, Xiaofeng Duan and Lijun Bo revised the manuscript.
Conflicts of interest
None.
Acknowledgements
We gratefully acknowledge the technical assistance of Ms. Hanying Xing in Hebei General Hospitial. This work was also supported by Natural Science Foundation of Hebei Province (No.H2014206454).
References (47)
- et al.
Ketamine for conscious sedation in pediatric emergency care
Pharmacotherapy
(2005) - et al.
Clinical practice guideline for emergency department ketamine dissociative sedation: 2011 update
Ann. Emerg. Med.
(2011) Neurotoxicity of ketamine: known unknowns
Crit. Care Med.
(2012)- et al.
Ketamine induces toxicity in human neurons differentiated from embryonic stem cells via mitochondrial apoptosis pathway
Curr. Drug Saf.
(2012) - et al.
Developmental neurotoxicity of ketamine in pediatric clinical use
Toxicol. Lett.
(2013) - et al.
Repeated exposure to ketamine-xylazine during early development impairs motor learning-dependent dendritic spine plasticity in adulthood
Anesthesiology
(2015) - et al.
Only extra-high dose of ketamine affects l-glutamate-induced intracellular Ca(2+) elevation and neurotoxicity
Neurosci. Res.
(2015) - et al.
Developmental neurotoxicity of ketamine: morphometric confirmation, exposure parameters, and multiple fluorescent labeling of apoptotic neurons
Toxicol. Sci.
(2004) - et al.
Ketamine anesthesia during the first week of life can cause long-lasting cognitive deficits in rhesus monkeys
Neurotoxicol. Teratol.
(2011) - et al.
Molecular mechanisms of calcium-dependent neurodegeneration in excitotoxicity
Cell Calcium
(2003)
Coupling of the NMDA receptor to neuroprotective and neurodestructive events
Biochem. Soc. Trans.
NMDA receptor activation and PKC but not PKA lead to the modification of the long-term potentiation in the insular cortex induced by conditioned taste aversion: differential role of kinases in metaplasticity
Behav. Brain Res.
NMDA-induced ERK signalling is mediated by NR2B subunit in rat cortical neurons and switches from positive to negative depending on stage of development
Neuropharmacology
Cell cycle control across the eukaryotic kingdom
Trends Cell Biol.
Cell cycle molecules define a pathway required for neuron death in development and disease
Biochim. Biophys. Acta
Cell cycle reactivation in mature neurons: a link with brain plasticity, neuronal injury and neurodegenerative diseases?
Neurosci. Bull.
Interplay between MEK-ERK signaling, cyclin D1, and cyclin-dependent kinase 5 regulates cell cycle reentry and apoptosis of neurons
Mol. Biol. Cell
Interaction between paired-pulse facilitation and long-term potentiation in the projection from hippocampal area CA1 to the entorhinal cortex
Neurosci. Res.
The hippocampus
Curr. Biol.
Ketamine potentiates hippocampal neurodegeneration and persistent learning and memory impairment through the PKCgamma-ERK signaling pathway in the developing brain
Brain Res.
Inhibition of p75 neurotrophin receptor attenuates isoflurane-mediated neuronal apoptosis in the neonatal central nervous system
Anesthesiology
Re-entry into the cell cycle: a mechanism for neurodegeneration in Alzheimer disease
Med. Hypotheses
Cell cycle regulation in the postmitotic neuron: oxymoron or new biology?
Nat. Rev. Neurosci.
Cited by (21)
Ketamine and its metabolites: Potential as novel treatments for depression
2023, NeuropharmacologyCitation Excerpt :Similar results were observed with ketamine (Olney et al., 1989). Although the underlying mechanisms remain unknown, a recent study reversed these effects using excitatory NMDAR activation (Jiang et al., 2018), suggesting that this potential neurotoxicity and cognitive impairment may be mediated via NMDAR blockade. Conversely, some studies have concluded that ketamine, at therapeutic doses, does not cause cognitive impairment.
General anesthetic neurotoxicity in the young: Mechanism and prevention
2019, Neuroscience and Biobehavioral ReviewsCitation Excerpt :Earlier studies demonstrated a link between the Trk signaling pathway and GA-induced neurotoxicity (Jiang et al., 2018; Zhu et al., 2018; Reus et al., 2016; Huang et al., 2016). Biochemical dissection of the molecular mechanisms involved has shown that GA administration at the time of the brain growth spurt inhibits phosphorylation of ERK and simultaneously down-regulates ERK activity (Jiang et al., 2018; Zhu et al., 2018; Reus et al., 2016; Huang et al., 2016). Subsequently, a significant decrease of cyclic AMP-response element binding protein (CREB) transcription factor production induces cell death, neuronal degeneration and synaptic loss.
Curcumin-ZnO conjugated nanoparticles confer neuroprotection against ketamine-induced neurotoxicity
2024, Journal of Biochemical and Molecular ToxicologyGRM2 Regulates Functional Integration of Adult-Born DGCs by Paradoxically Modulating MEK/ERK1/2 Pathway
2023, Journal of Neuroscience
- 1
Co-first author.