Moderate static magnetic field modulated lipid metabolism abnormalities induced by continuous artificial light in Caenorhabditis elegans: Role of iron ions

Excessive use of artificial light sources has led to a significant increase in light pollution, which has raised serious concerns due to its serious adverse effects on lipid metabolism. Although moderate static magnetic fields (SMFs) have shown potential in health intervention and treatment as non-invasive and highly permeable physical field, the influence of SMFs on lipid metabolic disturbance induced by lights remains largely unknown. In this study, we explored the lipid metabolism of Caenorhabditis elegans (C. elegans) under varying wavelengths of light ranging from 395 nm to 635 nm, both in the presence and absence of a 0.5 T SMF, and elucidated their underlying mechanisms. Exposure of C. elegans to artificial light at 200 lux resulted in a shortened lifespan while significantly increasing fat accumulation in a wavelength-dependent manner. The presence of 0.5 T SMF significantly extended the lifespan and reduced the size of fat droplets, as well as the content of triglyceride in light exposed worms. These effects were achieved by upregulating the expression of genes related to lipolysis and downregulating the expression of genes related to lipid synthesis. Moreover, the 0.5 T SMF alleviated abnormalities in lipid metabolism caused by light through the regulation of iron ions. Our findings provided clear evidence that moderate SMFs have significant protective effects on lipid metabolism abnormalities induced by artificial light via mediating iron homeostasis, which might contribute to a better understanding of the combined photomagnetic effects in living organisms.