Related Experiment Video
Updated: Dec 12, 2025
Isolation and Flow Cytometric Assessment of Neuroimmune Interactions in a Mini-Stroke Murine Model
Published on: June 20, 2025
Neuroinflammation and microglia/macrophage phenotype modulate the molecular background of post-stroke depression: A
Előd Ernő Nagy1, Attila Frigy2, József Attila Szász3
1Department of Biochemistry and Environmental Chemistry, 'George Emil Palade' University of Medicine, Pharmacy, Science and Technology of Targu Mures, 540139 Targu Mures, Romania.
Abstract:
Increasing evidence hints to the central role of neuroinflammation in the development of post-stroke depression. Danger signals released in the acute phase of ischemia trigger microglial activation, along with the infiltration of neutrophils and macrophages. The increased secretion of proinflammatory cytokines interleukin (IL)-1β, IL-6, IL-8, and tumor necrosis factor α (TNFα) provokes neuronal degeneration and apoptosis, whereas IL-6, interferon γ (IFNγ), and TNFα induce aberrant tryptophane degradation with the accumulation of the end-product quinolinic acid in resident glial cells. This promotes glutamate excitotoxicity via hyperexcitation of N-methyl-D-aspartate receptors and antagonizes 5-hydroxy-tryptamine, reducing synaptic plasticity and neuronal survival, thus favoring depression. In the post-stroke period, CX3CL1 and the CD200-CD200R interaction mediates the activation of glial cells, whereas CCL-2 attracts infiltrating macrophages. CD206 positive cells grant the removal of excessive danger signals; the high number of regulatory T cells, IL-4, IL-10, transforming growth factor β (TGFβ), and intracellular signaling via cAMP response element-binding protein (CREB) support the M2 type differentiation. In favorable conditions, these cells may exert efficient clearance, mediate tissue repair, and might be essential players in the downregulation of molecular pathways that promote post-stroke depression.
Insights
Neuroinflammation plays a key role in post-stroke depression by triggering microglial activation and cytokine release. Specific cellular and molecular pathways may offer targets for preventing or treating depression after stroke.
Area of Science:
- Neuroscience
- Immunology
- Pathology
Background:
- Neuroinflammation is increasingly recognized as a critical factor in the development of post-stroke depression.
- Ischemic events trigger danger signals, leading to microglial activation and the infiltration of immune cells like neutrophils and macrophages.
Purpose of the Study:
- To elucidate the complex molecular and cellular mechanisms underlying neuroinflammation in post-stroke depression.
- To identify potential therapeutic targets for mitigating depression following stroke.
Main Methods:
- Review of current evidence on the role of cytokines (IL-1β, IL-6, IL-8, TNFα, IFNγ) and their signaling pathways.
- Analysis of glial cell activation (microglia, macrophages) and immune cell interactions (neutrophils, T cells).
- Investigation of molecular mediators such as quinolinic acid, CX3CL1, CD200-CD200R, CCL-2, and CD206.
Main Results:
- Pro-inflammatory cytokines contribute to neuronal damage, apoptosis, and excitotoxicity via N-methyl-D-aspartate receptors.
- Aberrant tryptophan degradation leads to quinolinic acid accumulation, exacerbating neurotoxicity and reducing synaptic plasticity.
- Immune cell interactions and signaling pathways (e.g., CX3CL1, CCL-2) modulate glial activation and macrophage infiltration.
- Regulatory T cells and specific cytokines (IL-4, IL-10, TGFβ) promote M2 macrophage differentiation, crucial for tissue repair and resolution of inflammation.
Conclusions:
- Neuroinflammation, characterized by specific cytokine profiles and immune cell dynamics, is a significant driver of post-stroke depression.
- The balance between pro-inflammatory and anti-inflammatory pathways, including M2 macrophage polarization, is critical for recovery.
- Targeting these neuroinflammatory pathways holds promise for developing novel therapeutic strategies for post-stroke depression.
