Protein expression changes during phagocytosis influenced by low-frequency electromagnetic field exposure

Area of Science:

• Immunology
• Biophysics

Background:

• Macrophages play a crucial role in the innate immune system, engulfing pathogens and cellular debris through phagocytosis.
• Immune responses involve complex signaling pathways regulated by protein and gene expression.
• Low-frequency electromagnetic fields (EMF) are being explored for their potential biological effects.

Purpose of the Study:

• To investigate the impact of low-frequency EMF on macrophage phagocytosis and immune-related protein/gene expression.
• To assess changes in specific proteins (iPLA, cPLA, iNOS, NLR3/4, Hsp70) and iNOS mRNA levels in human monocytic macrophages (MM6) after EMF exposure.

Main Methods:

• Human monocytic macrophage (MM6) cell line was used for in vitro studies.
• Cells were pre-stimulated with lipopolysaccharide (LPS), Staphylococcal enterotoxin B (SEB), or phytohaemagglutinin (PHA).
• Phagocytosis assay with latex beads (LBs) was performed, followed by EMF exposure (30 mT, 7 Hz, 3 h).
• Protein expression was analyzed using Western blot; mRNA levels were determined by reverse transcription PCR.

Main Results:

• EMF exposure modulated the expression of several immune-related proteins, with notable changes in PLA2 and NLC4 levels.
• Significant alterations were observed in the expression of inducible nitric oxide synthase (iNOS) protein and its corresponding mRNA.
• The strongest effect of EMF on iNOS mRNA was seen in cells pre-stimulated with LPS or SEB and undergoing phagocytosis of LBs.

Conclusions:

• This study provides the first experimental evidence of EMF influencing phagocytosis.
• EMF exposure significantly impacts iNOS gene expression in macrophages, particularly under specific immune stimulation conditions.
• Further research is warranted to explore the potential of EMF as a supportive therapy in immune modulation.