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Intrastriatal Injection of Autologous Blood or Clostridial Collagenase as Murine Models of Intracerebral Hemorrhage
Published on: July 3, 2014
Microglial Mechanisms and Therapeutic Potential in Brain Injury Post-Intracerebral Hemorrhage
Yuhua Gong1,2, Hui Li1, Huanglin Cui1
1School of Smart Health, Chongqing Polytechnic University of Electronic Technology, Chongqing, 401331, People's Republic of China.
Insights
Intracerebral hemorrhage (ICH) triggers M1 microglia, causing secondary injury. M2 microglia emerge within 7 days, aiding repair and improving prognosis, offering potential therapeutic targets.
Area of Science:
- Neuroscience
- Immunology
- Pathology
Background:
- Intracerebral hemorrhage (ICH) is a major cause of death and disability with limited treatment options.
- ICH incidence is rising due to an aging population, better vascular prevention, and increased antithrombotic use.
- Understanding ICH mechanisms is crucial for developing effective interventions.
Purpose of the Study:
- To provide a comprehensive overview of microglial dynamics after ICH.
- To elucidate the role of microglia in primary and secondary injury, as well as neurorepair.
- To explore potential therapeutic strategies targeting microglia for ICH treatment.
Main Methods:
- Review of current scientific literature on microglial responses to ICH.
- Analysis of microglial activation states (M1 and M2) and their temporal dynamics.
- Examination of factors influencing microglial polarization, including cellular crosstalk, metabolism, and microbiota.
Main Results:
- M1 microglia are activated early post-ICH, contributing to primary and secondary injury (oxidative stress, neuronal damage, edema).
- M2 microglia polarization occurs within 7 days, facilitating debris clearance and reducing inflammation.
- Microglial M2 polarization is essential for neurorepair and improving clinical outcomes.
Conclusions:
- Microglial polarization is a critical determinant of ICH outcome.
- Targeting microglial M1 to M2 transition presents a promising therapeutic avenue.
- Further research into microglial interactions and signaling pathways is needed for clinical translation.
Abstract:
Intracerebral hemorrhage (ICH) is a particularly common public health problem with a high mortality and disability rate and no effective treatments to enhance clinical prognosis. The increased aging population, improved vascular prevention, and augmented use of antithrombotic agents have collectively contributed to the rise in ICH incidence over the past few decades. The exploration and understanding of mechanisms and intervention strategies has great practical significance for expanding treatments and improving prognosis of ICH. Microglia, as resident macrophages of central nervous system, are responsible for the first immune defense post-ICH. After ICH, M1 microglia is firstly activated by primary injury and thrombin; subsequently, reactive microglia can further amplify the immune response and exert secondary injury (eg, oxidative stress, neuronal damage, and brain edema). The pro-inflammatory phenotype transmits to M2 microglia within 7 days post-ICH, which plays a key role in erythrophagocytosis and limiting the inflammatory secondary injury. Microglial M2 polarization has significant implications for improving prognosis, this process can be mediated through crosstalk with other cells, metabolic changes, and microbiota interaction. Clarifying the effect, timing, and potential downstream effects of multiple mechanisms that synergistically trigger anti-inflammatory responses may be necessary for clinical translation. Analyses of such intricate interaction between microglia cells and brain injury/repair mechanisms will contribute to our understanding of the critical microglial responses to microenvironment and facilitating the discovery of appropriate intervention strategies. Here, we present a comprehensive overview of the latest evidences on microglial dynamics following ICH, their role in driving primary/secondary injury mechanisms as well as neurorepair/plasticity, and possible treatment strategies targeting microglia.
