Macrophage S1PR2 Drives Sepsis-induced Immunosuppression by Exacerbating Mitochondrial Fragmentation

Macrophage mitochondrial dysfunction is associated with immunosuppression and poor prognosis of septic patients. Mitochondrial fragmentation drives mitochondrial dysfunction. Our previous study has found that S1PR2 regulates macrophage phagocytosis during sepsis, while the role of S1PR2 in immunosuppression and the mechanisms remain further studied. This study aimed to unveil the relationship between macrophage mitochondrial fragmentation and sepsis-induced immunosuppression, as well as the S1PR2-related mechanisms thereof. Peripheral blood monocytes were collected from healthy controls (n = 12), nonseptic critical controls (n = 13) and septic patients (n = 19). Peritoneal macrophages were harvested from wildtype and