Effects of a single-session high-frequency repetitive magnetic stimulation on the autophagy marker LC3 and on LPS-induced inflammation in THP-1-derived macrophages

High-frequency repetitive magnetic stimulation (rMS) has emerged as a non-invasive technique capable of modulating cellular signaling pathways, including those involved in inflammation and oxidative stress. Our previous work demonstrated that high-frequency rMS modulated p62/SQSTM1 expression. Given the intricate link between p62 and autophagy, we hypothesized that high-frequency rMS might influence autophagic processes in macrophages. This study investigated the effects of a single high-frequency rMS treatment on autophagy and inflammation in THP-1-derived macrophages. The results showed that 10 Hz rMS decreased autophagy, evidenced by a reduction in LC3-II expression, quantified by Western blot, and a decrease in autophagic flux, assessed by flow cytometry following bafilomycin A1 treatment. Immunofluorescence assays were used to evaluate the number of LC3-positive and LysoTracker-positive puncta. Furthermore, rMS treatment attenuated lipopolysaccharide-induced inflammation and M1 polarization in THP-1-derived macrophages, as demonstrated by the downregulation of genes encoding pro-inflammatory cytokines (IL-1{beta}, IL-6, TNF-) and M1 polarization markers (IL-23 and CCR7). These findings suggest that high-frequency rMS exerts a regulatory effect on autophagy and inflammation in macrophages, providing a novel approach for the treatment of inflammatory and autophagy-related diseases.