Related Experiment Video
Updated: Aug 16, 2025
Characterization and Isolation of Mouse Primary Microglia by Density Gradient Centrifugation
Published on: February 16, 2018
Melatonin promotes microglia toward anti-inflammatory phenotype after spinal cord injury
Yue Guo1, Peng Zhang2, Haosen Zhao3
1Department of Orthopedic, First Affiliated Hospital of Jinzhou Medical University, Jinzhou, China; Key Laboratory of medical tissue engineering, Jinzhou Medical University, Jinzhou, P. R. China.
Abstract:
Microglia, immune cells in the central nervous system (CNS), mediate inflammatory responses and provide support to the microenvironment. Neurotoxic microglia predominantly locate in the injured spinal cord that delay spinal cord injury (SCI) repair. We previously found that melatonin could suppress SCI-induced neuronal inflammatory activation. However, the effect of melatonin in microglia responses remains unclear. In this study, isolated primary microglia and neurons were stimulated with lipopolysaccharide (LPS) and interferon-γ (IFN-γ) or melatonin-containing medium. We found that melatonin supported the beneficial polarization from pro-inflammatory to anti-inflammation, downrehulated ROS activity, and recovered mitochondrial metabolism in vitro and in vivo. Furthermore, melatonin downregulated pro-inflammatory-related mRNA levels. These results suggested that melatonin may be therapeutic potential for neuroinflammation-related neurological disorders, such as SCI.
Insights
Melatonin shifts microglia from harmful to helpful, reducing inflammation and improving cell function in spinal cord injury models. This suggests melatonin as a potential therapy for neurological disorders.
Area of Science:
- Neuroscience
- Immunology
- Cell Biology
Background:
- Microglia are central nervous system immune cells involved in inflammation and tissue support.
- Neurotoxic microglia in injured spinal cords impede spinal cord injury (SCI) repair.
- Melatonin previously showed potential in suppressing SCI-induced neuronal inflammation.
Purpose of the Study:
- To investigate the effect of melatonin on microglia responses in the context of SCI.
- To determine if melatonin can modulate microglial polarization and function.
Main Methods:
- Primary microglia and neurons were isolated and stimulated with inflammatory agents (LPS and IFN-γ) or melatonin.
- Microglial polarization, reactive oxygen species (ROS) activity, and mitochondrial metabolism were assessed in vitro and in vivo.
- Pro-inflammatory mRNA levels were quantified.
Main Results:
- Melatonin promoted a shift from pro-inflammatory to anti-inflammatory microglial phenotypes.
- Melatonin downregulated ROS production and restored mitochondrial metabolism.
- Melatonin reduced the expression of pro-inflammatory genes.
Conclusions:
- Melatonin exhibits neuroprotective effects by modulating microglial responses.
- Melatonin demonstrates therapeutic potential for neuroinflammation-related conditions, including SCI.
