Inflammasome-Mediated Neuroinflammation in Major Depression

Major depressive disorder has increasingly been linked to innate immune activation within the brain, where inflammasome complexes act as molecular sensors of stress and injury. Upon detecting cellular danger signals, these oligomeric platforms recruit and activate caspase-1, leading to the maturation of pro-inflammatory cytokines such as interleukin-1β and interleukin-18 as well as a lytic form of cell death known as pyroptosis. In key limbic regions including the hippocampus and prefrontal cortex, microglia and astrocytes mount an exaggerated inflammasome-driven response under chronic stress, perturbing synaptic plasticity, neurogenesis and neuronal survival. The resultant imbalance of pro- and anti-inflammatory mediators contributes to behavioural phenotypes characteristic of depression, such as anhedonia and psychomotor slowing. Convergent evidence from animal models and human post-mortem studies highlights the pivotal role of the NLRP3 (NOD-, LRR- and pyrin-domain-containing protein 3) inflammasome, though other sensors such as NLRP1 have also been implicated. Targeting inflammasome activation and its downstream effectors represents a promising avenue for novel antidepressant therapies that directly address the neuroimmune dimension of major depression.

Research from Nature Portfolio

Recent studies have demonstrated that the endogenous ketone body beta-hydroxybutyrate mitigates stress-induced depressive-like behaviours in rodents by selectively inhibiting NLRP3 inflammasome activation in the hippocampus. Repeated administration of beta-hydroxybutyrate attenuated both interleukin-1β and tumour necrosis factor-α elevations following acute and chronic stress paradigms, restoring behavioural performance in forced-swim and elevated-plus-maze tests. This work underscores the potential of metabolic substrates to modulate neuroinflammatory cascades and offers proof of concept for inflammasome-targeted interventions in stress-related mood disorders.

Inflammasome-Mediated Neuroinflammation in Major Depression publication trend

The graph below shows the total number of articles in inflammasome-mediated neuroinflammation in major depression across all publications each year (not limited to Nature Index journals).

Technical terms

Inflammasome: A multiprotein cytosolic complex that detects cellular stress signals and activates inflammatory caspases.

NLRP3 inflammasome: A specific pattern-recognition complex comprising the sensor NLRP3, adaptor ASC and pro-caspase-1, central to stress-induced neuroinflammation.

Pyroptosis: A form of programmed, lytic cell death mediated by gasdermin-D pores, resulting in the release of inflammatory cytokines.

Microglia: Resident immune cells of the central nervous system that orchestrate inflammatory and repair processes in the brain.

Astrocyte: A glial cell type providing metabolic support and maintaining extracellular homeostasis, which can undergo inflammasome-driven dysfunction in depression.

References

1. Berberine ameliorates depression-like behaviors in mice via inhibiting NLRP3 inflammasome-mediated neuroinflammation and preventing neuroplasticity disruption. Journal of Neuroinflammation (2023).
2. Melatonin alleviates chronic stress-induced hippocampal microglia pyroptosis and subsequent depression-like behaviors by inhibiting Cathepsin B/NLRP3 signaling pathway in rats. Translational Psychiatry (2024).
3. NLRP1 inflammasome contributes to chronic stress-induced depressive-like behaviors in mice. Journal of Neuroinflammation (2020).
4. Beta-hydroxybutyrate, an endogenic NLRP3 inflammasome inhibitor, attenuates stress-induced behavioral and inflammatory responses. Scientific Reports (2017).
5. Inflammasomes in neuroinflammation and changes in brain function: a focused review. Frontiers in Neuroscience (2014).