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Increasing evidence demonstrates that pyroptosis, pro-inflammatory programmed cell death, is linked to acute lung injury (ALI). Dihydromyricetin (DHM) has been reported to exert anti-inflammatory effects by inhibiting NLRP3 inflammasome activation in vascular endothelial cells. However, the effects of DHM on NLRP3 inflammasome-induced pyroptosis in ALI remain elusive. In the present study, male BALB/c mice were subjected to cecal ligation and puncture (CLP), and DHM (50, 100, 150 mg/kg) was orally administered (once per day, for 3 days) 2 h after CLP. After 72 h, lung histopathology was examined, and the wet/dry (W/D) ratio, inflammatory infiltration, total protein concentration, total cell, and neutrophil counts were detected. Myeloperoxidase (MPO), interleukin (IL)-6, TNF-α, IL-1β, and IL-18 levels in bronchoalveolar lavage fluid (BALF) were measured by ELISA. Additionally, the expression of NLRP3 signaling pathway proteins were detected by Western blotting. The results revealed that in BALF, DHM (150 mg/kg) treatment significantly reduced the CLP-induced lung histopathological injury, inflammatory cell infiltration, total cell and neutrophil number, and total protein and albumin concentration. DHM treatment significantly inhibited the CLP-induced NLRP3 inflammasome pathway (NLRP3, ASC, caspase-1, gasdermin D (Gsdmd), IL-1β, and IL-18). In conclusion, these results demonstrate that DHM protects against CLP-induced ALI by inhibiting NLRP3 inflammasome activation and subsequent pyroptosis. [ABSTRACT FROM AUTHOR]

Increasing evidence indicates that FK866, a specific noncompetitive nicotinamide phosphoribosyl transferase inhibitor, exhibits a protective effect on acute lung injury (ALI). Autophagy plays a pivotal role in sepsis-induced ALI. However, the contribution of autophagy and the underlying mechanism by which FK866-confered lung protection remains elusive. Herein, we aimed to study whether FK866 could alleviate sepsis-induced ALI via the JNK-dependent autophagy. Male C57BL/6 mice were subjected to cecal ligation and puncture (CLP) to establish the polymicrobial sepsis mice model, and treated with FK866 (10 mg/kg) at 24, 12 and 0.5 h before the CLP procedure. The lung protective effects were measured by lung histopathology, tissue edema, vascular leakage, inflammation infiltration, autophagy-related protein expression and JNK activity. A549 cells were stimulated with LPS (1000 ng/ml) to generate the ALI cell model, and pretreated with FK866 or SP600125 for 30 min to measure the autophagy-related protein expression and JNK activity. Our results demonstrated that FK866 reduced lung injury score, tissue edema, vascular leakage, and inflammatory infiltration, and upregulated autophagy. The protective effect of autophagy conferred by FK866 on ALI was further clarified by using 3-methyladenine (3MA) and rapamycin. Additionally, the activity of JNK was suppressed by FK866, and inhibition of JNK promoted autophagy and showed a benefit effect. Our study indicates that FK866 protects against sepsis-induced ALI by induction of JNK-dependent autophagy. This may provide new insights into the functional mechanism of NAMPT inhibition in sepsis-induced ALI. • Levels of NAMPT expression were increased in a sepsis-related ALI mice model. • NAMPT inhibitor FK866 attenuated sepsis-induced ALI by upregulating autophagy. • JNK was a potent negative regulator of autophagy conferred by FK866 on lung protection. [ABSTRACT FROM AUTHOR]

• Sepsis-associated encephalopathy impairs cognitive functions and inhibits synaptic plasticity. • Caspase-1 inhibitor treatment ameliorates cognitive dysfunction and protects brain ultrastructure in septic mice. • Caspase-1 inhibitor treatment mitigated inflammatory cytokines robust and diminished microglia activation in septic mice. Sepsis-associated encephalopathy (SAE) manifested clinically in acute and long-term cognitive impairments and associated with increased morbidity and mortality worldwide. The potential pathological changes of SAE are complex and remain to be elucidated. Pyroptosis, a novel programmed cell death, is executed by caspase-1-cleaved GSDMD N-terminal (GSDMD-NT) and we investigated it in peripheral blood immunocytes of septic patients previously. Here, a caspase-1 inhibitor VX765 was treated with CLP-induced septic mice. Novel object recognition test indicated that VX765 treatment reversed cognitive dysfunction in septic mice. Elevated plus maze, tail suspension test and open field test revealed that depressive-like behaviors of septic mice were relieved. Inhibited caspase-1 suppressed the expressions of GSDMD and its cleavage form GSDMD-NT, and reduced pyroptosis in brain at day 1 and day 7 after sepsis. Meantime, inhibited caspase-1 mitigated the expressions of IL-1β, MCP-1 and TNF-α in serum and brain, diminished microglia activation in septic mice, and reduced sepsis-induced brain-blood barrier disruption and ultrastructure damages in brain as well. Inhibited caspase-1 protected the synapse plasticity and preserved long-term potential, which may be the possible mechanism of cognitive functions protective effects of septic mice. In conclusion, caspase-1 inhibition exerts brain-protective effects against SAE and cognitive impairments in a mouse model of sepsis. [ABSTRACT FROM AUTHOR]