Immune Inflammation in Brown Adipose Tissue and Altered Lipid Metabolism in the Liver Under Geomagnetic Field Shielding

Abstract Objective Hypomagnetic field is an environmental factor in deep space that affect multiple systems in human body, but how they impact the immunometabolism of metabolic tissues such as brown adipose tissue (BAT) and liver is still unclear. This study used geomagnetic shielding (GS) environment to simulate hypomagnetic field and preliminarily explored its effects on BAT and liver immunometabolism. Results GS environment caused different immunometabolic changes in BAT and liver. In BAT, the GS environment was associated with immune inflammatory pathways and also affected glucose and lipid metabolism as well as autophagy related to lipid droplets (LDs). Transferrin receptors were enriched on LDs in both GS and non-GS conditions. In liver, GS environment was linked to lipid metabolic pathways such as cholesterol, fatty acid, and glycerophospholipid metabolism, and innate immune responses related to antiviral defense were also activated. Fatty acid synthase was upregulated at both transcriptomic and LD proteomic levels. Furthermore, TAG accumulated significantly in hepatic LDs under GS conditions. These results suggest that GS environment leads to tissue-specific immunometabolic changes in BAT and liver, providing a theoretical basis for developing health protection strategies for astronauts.