Related Experiment Video
Updated: Jan 6, 2026
Three-dimensional Confocal Analysis of Microglia/macrophage Markers of Polarization in Experimental Brain Injury
Published on: September 4, 2013
Microglial Polarization and Therapeutic Strategies in Post-stroke Neuroinflammation
Travis Yui Hei Chan1, Brian De Yu Ma1, Timothy Keith Hung1
1Division of Neurosurgery, LKS Faculty of Medicine, The University of Hong Kong, Pok Fu Lam, Hong Kong.
Abstract:
Stroke remains a leading cause of global disability, perpetuated by maladaptive neuroinflammation that drives secondary injury and impairs recovery. An early reparative (M2) state rapidly transitions into a dominant destructive (M1) phenotype within days, worsening tissue damage through the release of cytokines [tumor necrosis factor alpha (TNFα), interleukin-6 (IL-6)], blood-brain barrier disruption, and amplified peripheral immune cell infiltration. Emerging pharmacological interventions, such as the free radical scavenger edaravone, the neurotrophic factor cerebrolysin, and the excitotoxicity modulator citicoline, demonstrate promising neuroprotective potential when strategically timed. Additionally, novel non-pharmacological approaches, including repetitive transcranial magnetic stimulation, stem cell therapy, and nanoparticle-based drug delivery, offer innovative pathways for targeting neuroinflammation. However, translational challenges persist, including narrow therapeutic windows, biomarker heterogeneity, and preclinical-to-clinical gaps. Future progress necessitates precision medicine paradigms integrating spatiotemporal drug delivery, biomarker-guided intervention timing, and synergistic combinatorial regimens targeting acute injury and chronic repair phases. By bridging mechanistic insights with clinical applications, this review delineates neuroinflammatory modulation as a pivotal frontier for redefining stroke recovery while outlining essential research trajectories to overcome existing barriers. Systematic search of electronic databases including PubMed, Web of Science, Embase, and Cochrane (1996-2025) was performed, with eligible studies assessed using PRISMA guidelines. Findings on neuroinflammation, mechanism, or interventions in ischemic stroke were narratively synthesized through thematic analysis. This review summarizes current insights into post-stroke neuroinflammatory mechanisms, with a focus on the dual role of microglial polarization.
Insights
Stroke recovery is hindered by neuroinflammation, where immune cells shift from repair to damage. Targeting this inflammation with new drugs and therapies offers hope for better outcomes.
Area of Science:
- Neuroscience
- Immunology
- Pharmacology
Background:
- Stroke causes significant global disability, largely due to detrimental neuroinflammation.
- Post-stroke, the immune response shifts from a reparative (M2) to a destructive (M1) phenotype, exacerbating tissue damage.
- Key mediators include pro-inflammatory cytokines (TNFα, IL-6), blood-brain barrier disruption, and peripheral immune cell infiltration.
Purpose of the Study:
- To review current understanding of post-stroke neuroinflammatory mechanisms, focusing on microglial polarization.
- To explore emerging pharmacological and non-pharmacological interventions for modulating neuroinflammation.
- To identify translational challenges and future research directions for optimizing stroke recovery.
Main Methods:
- Systematic literature search of major electronic databases (PubMed, Web of Science, Embase, Cochrane) from 1996-2025.
- Eligibility assessment of studies using PRISMA guidelines.
- Narrative synthesis of findings on neuroinflammation, mechanisms, and interventions in ischemic stroke through thematic analysis.
Main Results:
- Neuroinflammation plays a dual role, with early reparative phases transitioning to destructive M1 phenotypes.
- Pharmacological agents (edaravone, cerebrolysin, citicoline) and non-pharmacological approaches (TMS, stem cells, nanoparticles) show therapeutic potential.
- Significant translational hurdles exist, including narrow therapeutic windows and biomarker variability.
Conclusions:
- Modulating neuroinflammation is crucial for improving stroke recovery.
- Precision medicine approaches, including spatiotemporal drug delivery and biomarker-guided timing, are essential.
- Future research should focus on combinatorial strategies targeting both acute injury and chronic repair phases to overcome existing barriers.
