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Updated: Jun 29, 2026
Assessing Microglial Phagocytosis of Myelin Debris in vitro Under Repeated Magnetic Stimulation
Published on: June 17, 2025
Frequency-specific effects of pulsed magnetic field on BV2 microglial cell function
Anning Song1, Yaqing Zhao1, Shuaiju Wu1
1State Key Laboratory of Reliability and Intelligence of Electrical Equipment, School of Health Sciences and Biomedical Engineering, Hebei University of Technology, Tianjin, China.
Abstract:
The objective of this study was to investigate the effects of pulsed magnetic field (PMF) at different frequencies on phagocytosis, migration, and the expression of inflammatory factors in microglia. BV2 microglia were subjected to PMF at different frequencies for 3 d, twice daily. The changes of cell viability, phagocytosis and migration after magnetic stimulation were detected. The mRNA and protein levels of TNF-α and IL-1β were determined using RT-PCR and ELISA. The nuclear translocation of NF-κB P65 and intracellular Ca2+ level was detected through immunofluorescence. PMF at different frequencies did not affect microglial viability. Stimulation at all frequencies enhanced the ability of microglia to phagocytosis and migration. The mRNA expression level of IL-1β and TNF-α was significantly decreased by magnetic stimulation at 20 Hz and 40 Hz. However, only the protein level of IL-1β was significantly reduced by magnetic stimulation at 20 Hz, while TNF-α remained unaffected. Magnetic stimulation at 20 Hz and 40 Hz inhibited the nuclear translocation of NF-κB P65 and increased the intracellular Ca2+ level. Repetitive magnetic stimulation can modulate the secretion of inflammatory cytokines and enhance the phagocytosis and migration capacity of microglia in a frequency-dependent manner. This variation may be linked to differences in the activation of NF-κB and calcium in microglia.
Insights
Pulsed magnetic field (PMF) stimulation enhanced microglial phagocytosis and migration without affecting viability. Specific frequencies (20Hz, 40Hz) reduced inflammatory markers, suggesting PMF as a potential therapeutic approach for neuroinflammation.
Area of Science:
- Neuroscience
- Biophysics
- Immunology
Background:
- Microglia play crucial roles in brain immunity and inflammation.
- Dysregulated microglial function contributes to neuroinflammatory diseases.
- Pulsed magnetic fields (PMF) offer a non-invasive method to modulate cellular functions.
Purpose of the Study:
- To investigate the impact of different PMF frequencies on microglial phagocytosis, migration, and inflammatory factor expression.
- To explore the underlying mechanisms involving NF-κB signaling and intracellular calcium.
Main Methods:
- BV2 microglia were exposed to PMF at various frequencies.
- Assessed cell viability, phagocytosis, and migration.
- Quantified mRNA and protein levels of TNF-α and IL-1β.
- Detected NF-κB p65 nuclear translocation and intracellular Ca2+ via immunofluorescence.
Main Results:
- PMF did not alter microglial viability across tested frequencies.
- All tested PMF frequencies enhanced microglial phagocytosis and migration.
- PMF at 20Hz and 40Hz decreased IL-1β and TNF-α mRNA levels.
- Only IL-1β protein levels were significantly reduced by 20Hz PMF.
- 20Hz and 40Hz PMF inhibited NF-κB p65 nuclear translocation and increased intracellular Ca2+.
Conclusions:
- Repetitive PMF stimulation modulates microglial inflammatory cytokine secretion and enhances phagocytosis/migration in a frequency-dependent manner.
- Observed variations in response may be associated with altered NF-κB activation and intracellular calcium levels.
- PMF demonstrates potential as a therapeutic tool for modulating microglial responses in neuroinflammatory conditions.
