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Updated: Aug 30, 2025
Isolation of Cortical Microglia with Preserved Immunophenotype and Functionality From Murine Neonates
Published on: January 30, 2014
Microglia-derived CCL2 has a prime role in neocortex neuroinflammation
Mariella Errede1, Tiziana Annese1,2, Valentina Petrosino3
1Department of Basic Medical Sciences, Neuroscience, and Sensory Organs, University of Bari School of Medicine, Piazza Giulio Cesare, Policlinics, 70124, Bari, Italy.
Background:
In myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis (EAE), several areas of demyelination are detectable in mouse cerebral cortex, where neuroinflammation events are associated with scarce inflammatory infiltrates and blood-brain barrier (BBB) impairment. In this condition, the administration of mesenchymal stem cells (MSCs) controls neuroinflammation, attenuating astrogliosis and promoting the acquisition of stem cell traits by astrocytes. To contribute to the understanding of the mechanisms involved in the pathogenesis of EAE in gray matter and in the reverting effects of MSC treatment, the neocortex of EAE-affected mice was investigated by analyzing the cellular source(s) of chemokine CCL2, a molecule involved in immune cell recruitment and BBB-microvessel leakage.
Methods:
The study was carried out by immunohistochemistry (IHC) and dual RNAscope IHC/in situ hybridization methods, using astrocyte, NG2-glia, macrophage/microglia, and microglia elective markers combined with CCL2.
Results:
The results showed that in EAE-affected mice, hypertrophic microglia are the primary source of CCL2, surround the cortex neurons and the damaged BBB microvessels. In EAE-affected mice treated with MSCs, microgliosis appeared diminished very soon (6 h) after treatment, an observation that was long-lasting (tested after 10 days). This was associated with a reduced CCL2 expression and with apparently preserved/restored BBB features. In conclusion, the hallmark of EAE in the mouse neocortex is a condition of microgliosis characterized by high levels of CCL2 expression.
Conclusions:
This finding supports relevant pathogenetic and clinical aspects of the human disease, while the demonstrated early control of neuroinflammation and BBB permeability exerted by treatment with MSCs may have important therapeutic implications.
Insights
In experimental autoimmune encephalomyelitis (EAE), microglia drive neuroinflammation by producing CCL2. Mesenchymal stem cell (MSC) treatment early reduces microgliosis and preserves the blood-brain barrier (BBB).
Area of Science:
- Neuroscience
- Immunology
- Stem Cell Biology
Background:
- Experimental autoimmune encephalomyelitis (EAE) in mice shows demyelination and blood-brain barrier (BBB) impairment in the cerebral cortex.
- Mesenchymal stem cells (MSCs) are known to control neuroinflammation and astrogliosis in EAE.
- Understanding the cellular sources of CCL2 is crucial for EAE pathogenesis and MSC therapeutic mechanisms.
Purpose of the Study:
- To investigate the cellular source of chemokine CCL2 in the neocortex of EAE-affected mice.
- To analyze the effect of mesenchymal stem cell (MSC) treatment on CCL2 expression and neuroinflammation in EAE.
- To elucidate the role of microglia and CCL2 in EAE pathogenesis and MSC therapeutic effects.
Main Methods:
- Immunohistochemistry (IHC) and dual RNAscope IHC/in situ hybridization were employed.
- Specific markers for astrocytes, NG2-glia, macrophages, and microglia were used in conjunction with CCL2.
- Analysis focused on the cellular localization of CCL2 in the neocortex of EAE mice with and without MSC treatment.
Main Results:
- Hypertrophic microglia were identified as the primary source of CCL2 in EAE-affected mouse neocortex.
- CCL2-producing microglia surrounded cortical neurons and damaged BBB microvessels.
- MSC treatment rapidly and persistently reduced microgliosis and CCL2 expression, preserving BBB integrity.
Conclusions:
- Microgliosis with high CCL2 expression is a key feature of EAE in the mouse neocortex.
- MSC treatment effectively controls neuroinflammation and BBB permeability in EAE.
- These findings have significant implications for understanding EAE pathogenesis and developing MSC-based therapies for related human diseases.
