Acetaminophen (APAP) overdose is a leading cause of drug-induced liver injury (DILI). The impact of the gut microbiota and associated metabolites on APAP and liver function remains unclear. We show that APAP disturbance is associated with a distinct gut microbial community, with notable decreases in Lactobacillus vaginalis. Mice receiving L. vaginalis showed resistance to APAP hepatotoxicity due to the liberation of the isoflavone daidzein from the diet by bacterial β-galactosidase. The hepatoprotective effects of L. vaginalis in APAP-exposed germ-free mice were abolished with a β-galactosidase inhibitor. Similarly, β-galactosidase-deficient L. vaginalis produced poorer outcomes in APAP-treated mice than the wild-type strain, but these differences were overcome with daidzein administration. Mechanistically, daidzein prevented ferroptotic death, which was linked to decreased expression of farnesyl diphosphate synthase (Fdps) that activated a key ferroptosis pathway involving AKT-GSK3β-Nrf2. Thus, liberation of daidzein by L. vaginalis β-galactosidase inhibits Fdps-mediated hepatocyte ferroptosis, providing promising therapeutic approaches for DILI.
Traumatic brain injury (TBI) is irreversible brain damage, leading to inflammation and cognitive dysfunction. Microglia involved in the inflammatory response after TBI. The gut microbiota, known as the body's "second brain," regulates neurogenesis and immune responses, but its precise role in regulating TBI remains unclear. to investigate the effect of gut microbiota and metabolites disorder on TBI injury. 16SrRNA and metabolomics compared gut microbiota and metabolites in sham group and TBI group, then proved that the differential metabolite 8-gingerol (8G) alleviated the microglia neuroinflammatory response after TBI. fecal microbiota transplantation explored the role of dysbiosis in TBI. LC/MS detected the content of 8-gingerol in cecum, blood, and brain. HE, Nissl, Tunel staining and mNSS score evaluated brain injury. Western blot and immunofluorescence detected the expression of inflammasome-related proteins and mitophagy-related proteins in brain tissue and BV2 cells. RNA sequencing analyzed the molecular mechanism of 8-gingerol. rats transplanted with TBI feces had worse brain injury and neurological deficits than those with normal feces. 16SrRNA and metabolomics found that TBI caused dysbiosis and decreased 8-gingerol level, leading to severe neuroinflammation. Mechanistically, 8-gingerol inhibited NLRP3 inflammasome by promoting PINK1-Parkin mediated mitophagy in microglia. Inhibition of Parkin, through either small interfering RNA or the inhibitor 3MA reversed the inhibitory effect of 8-gingerol on NLRP3 by blocking mitophagy. BV2 cells transcriptome showed that 8-gingerol significantly increased the expression of autophagy factor Wipi1, and small interfering RNA of Wipi1 abolished the effect of 8-gingerol on promoting mitophagy and the inhibitory effect on NLRP3. our findings shed light on the pivotal role of gut microbes in TBI, and identify 8 gingerol as an important anti-inflammatory compound during TBI.
Damage-associated molecular patterns (DAMPs) often cause an exaggerated immune response. Fatty acid-binding protein 5 (FABP5) is traditionally considered a cytosolic protein responsible for the transport of fatty acids. However, little is known about the role of FABP5 in sepsis. Herein, we found that circulating FABP5 levels were higher in patients with sepsis and were associated with adverse outcomes. The circulating FABP5 originated mainly from macrophage pyroptosis in the later stages of sepsis despite a decrease in cytoplasm-resident FABP5 expression. Functionally, circulating FABP5 penetrated the living macrophage membrane and bound to the intracellular domain of TLR4, ultimately inducing secondary inflammation through the NF-κB and MAPK pathways. Unlike circulating oxidized FABP5, cytoplasm-resident FABP5 was present in its reduced form and suppressed macrophage pyroptosis. Clearance of circulating DAMP FABP5 by preventing the passive release from dying macrophages or using a specific blocking antibody can improve survival in mice with sepsis.
Ulcerative colitis (UC) is characterised by chronic intestinal inflammation and its global prevalence is increasing. Although a variety of drugs have been