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Updated: Jul 17, 2026
Modeling Neuronal Death and Degeneration in Mouse Primary Cerebellar Granule Neurons
Published on: November 6, 2017
Tumor necrosis factor alpha stimulates NMDA receptor activity in mouse cortical neurons resulting in ERK-dependent
Javier H Jara1, Brij B Singh, Angela M Floden
1Department of Pharmacology, Physiology and Therapeutics, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota 58202, USA.
Abstract:
Multiple cytokines are secreted in the brain during pro-inflammatory conditions and likely affect neuron survival. Previously, we demonstrated that glutamate and tumor necrosis factor alpha (TNFalpha) kill neurons via activation of the N-methyl-d-aspartate (NMDA) and TNFalpha receptors, respectively. This report continues characterizing the signaling cross-talk pathway initiated during this inflammation-related mechanism of death. Stimulation of mouse cortical neuron cultures with TNFalpha results in a transient increase in NMDA receptor-dependent calcium influx that is additive with NMDA stimulation and inhibited by pre-treatment with the NMDA receptor antagonist, DL-2-amino-5-phosphonovaleric acid, or the alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate/kainate receptor antagonist, 6,7-dinitroquinoxaline-2,3-dione. Pre-treatment with N-type calcium channel antagonist, omega-conotoxin, or the voltage-gated sodium channel antagonist, tetrodotoxin, also prevents the TNFalpha-stimulated calcium influx. Combined TNFalpha and NMDA stimulation results in a transient increase in activity of extracellular signal-regulated kinases (ERKs) and c-Jun N-terminal kinases (JNKs). Specific inhibition of ERKs but not JNKs is protective against TNFalpha and NMDA-dependent death. Death is mediated via the low-affinity TNFalpha receptor, TNFRII, as agonist antibodies for TNFRII but not TNFRI stimulate NMDA receptor-dependent calcium influx and death. These data demonstrate how microglial pro-inflammatory secretions including TNFalpha can acutely facilitate glutamate-dependent neuron death.
Insights
Tumor necrosis factor alpha (TNFalpha) enhances glutamate-induced neuron death by increasing calcium influx via NMDA receptors. Inhibiting extracellular signal-regulated kinases (ERKs) protects neurons, revealing a key inflammatory pathway.
Area of Science:
- Neuroscience
- Neuroinflammation
- Cellular Signaling
Background:
- Pro-inflammatory cytokines, such as tumor necrosis factor alpha (TNFalpha), are released in the brain and can impact neuron survival.
- Previous work showed glutamate and TNFalpha induce neuron death through N-methyl-d-aspartate (NMDA) and TNFalpha receptors, respectively.
- Understanding the signaling crosstalk during inflammation-related neuron death is crucial.
Purpose of the Study:
- To characterize the signaling pathway involved in inflammation-related neuron death.
- To investigate the interaction between TNFalpha and NMDA receptor signaling.
- To identify specific molecular targets for neuroprotection.
Main Methods:
- Primary mouse cortical neuron cultures were stimulated with TNFalpha and/or NMDA.
- Calcium influx was measured using antagonists for NMDA receptors, AMPA/kainate receptors, N-type calcium channels, and sodium channels.
- Extracellular signal-regulated kinases (ERKs) and c-Jun N-terminal kinases (JNKs) activity was assessed.
- Neuron death was evaluated following specific kinase inhibition and receptor activation.
Main Results:
- TNFalpha stimulation increased NMDA receptor-dependent calcium influx, which was additive with NMDA stimulation and blocked by specific antagonists.
- N-type calcium channel and sodium channel blockers also inhibited TNFalpha-induced calcium influx.
- Combined TNFalpha and NMDA stimulation increased ERK and JNK activity; ERK inhibition protected against cell death.
- Activation of the TNFalpha receptor type II (TNFRII) mediated the observed calcium influx and cell death.
Conclusions:
- TNFalpha acutely facilitates glutamate-dependent neuron death by enhancing NMDA receptor activity and calcium influx.
- The low-affinity TNFalpha receptor, TNFRII, plays a critical role in this pro-death signaling pathway.
- Inhibition of ERKs offers a potential therapeutic strategy against inflammation-induced neurotoxicity.
