Related Experiment Video
Updated: Jul 15, 2026
Sub-acute Cerebral Microhemorrhages Induced by Lipopolysaccharide Injection in Rats
Published on: October 17, 2018
Methylene blue reduces the severity of lipopolysaccharide-induced morphological changes in microglia in rat cerebral
E V Stelmashook1, E E Genrikhs1, M R Kapkaeva1
1Russian Center of Neurology and Neurosciences, Moscow, Russia.
Abstract:
Neuroinflammation is a process implicated in the development of many neurodegenerative diseases. It involves microglia, astrocytes, and cytokines. The aim of this study was to investigate the effects of neuroprotectors on morphology of microglial cell during lipopolysaccharide (LPS)-induced neuroinflammation. Immunocytochemical detection of microglia using the IBA1 marker in glial cell cultures obtained from rat cerebral cortex revealed the presence of a significant number of microglial cells in the studied culture. In the control, microglial cells possessed a large number of processes typical of nonactivated cells. In cultures treated with LPS (10 μg/ml, 24 h), microglia had a flattened amoeboid morphology, characteristic of activated cells. Furthermore, LPS treatment also resulted in an increase in the profile field area of the cell body, while the perimeter did not increase significantly, indicating a more rounded cell body shape compared to the control. In cultures treated with methylene blue (1 μM, 24 h) in the presence of LPS, microglial cells had a larger number of processes and a smaller body profile area than microglia treated with LPS alone, and their perimeter did not differ significantly from that of control cells. In the case of menadione (1 μM, 24 h) in the presence of LPS, the cells retained an amoeboid shape, and their size did not change significantly compared to the LPS group. Microglia treated with methylene blue alone did not differ from control microglia in morphology, body profile area, or perimeter, whereas menadione caused a significant increase in the cell's body profile area and a shift in their morphology toward an activated phenotype. Methylene blue, a substance whose anti-inflammatory action is associated with Nrf2 activation, is capable of not only reducing the production of proinflammatory cytokines but also preventing the transition of microglia to the activated phenotype.
Insights
Neuroinflammation, a key factor in neurodegenerative diseases, involves microglia activation. Methylene blue, a neuroprotector, was found to prevent microglial activation during inflammation, unlike menadione.
Area of Science:
- Neuroscience
- Cell Biology
- Immunology
Background:
- Neuroinflammation is a critical process in neurodegenerative diseases.
- Microglia play a central role in neuroinflammation.
- Lipopolysaccharide (LPS) is commonly used to induce neuroinflammation in experimental models.
Purpose of the Study:
- To investigate the effects of potential neuroprotectors on microglial cell morphology during LPS-induced neuroinflammation.
- To compare the effects of methylene blue and menadione on microglial activation.
Main Methods:
- Primary glial cell cultures were established from rat cerebral cortex.
- Immunocytochemistry using the IBA1 marker was employed to detect and analyze microglial morphology.
- Cells were treated with LPS alone, or in combination with methylene blue or menadione.
Main Results:
- LPS treatment induced microglial activation, characterized by a flattened amoeboid morphology and increased cell body area.
- Methylene blue treatment, in the presence of LPS, preserved microglial processes and reduced cell body area, indicating a less activated state.
- Menadione treatment, with LPS, did not significantly alter the activated morphology or size of microglia compared to LPS alone.
- Methylene blue alone did not affect microglial morphology, while menadione alone induced an activated phenotype.
Conclusions:
- Methylene blue effectively prevents the transition of microglia to an activated phenotype during LPS-induced neuroinflammation.
- Methylene blue's anti-inflammatory effects may be mediated through Nrf2 activation, reducing pro-inflammatory cytokine production.
- These findings suggest methylene blue as a potential therapeutic agent for neurodegenerative diseases associated with neuroinflammation.
