Luteolin ameliorates LPS-induced acute liver injury by inhibiting TXNIP-NLRP3 inflammasome in mice.

Chemical liver injury is one of the main causes of acute liver failure and death. To date, however, treatment strategies for acute liver injury have been limited. Therefore, there is an urgent need to find new therapeutic targets and effective drugs. NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome is a complex of multiple proteins that has been shown to induce cell death under inflammatory and stress pathologic conditions and is thought to provide new targets for the treatment of a variety of diseases. The purpose of this study was to investigate whether luteolin has a protective effect on the liver and further elucidate whether it is realized through the thioredoxin interacting protein (TXNIP)-NLRP3 axis. Acute hepatic injury in mice caused by intraperitoneal injection of lipopolysaccharide (LPS) was treated with or without luteolin. Male C57BL/6 mice and mouse primary hepatocytes were selected. TXNIP protein knockdown was achieved by siRNA, qPCR and Western blot were performed to explore the mechanism of luteolin in alleviating acute liver injury. The results indicated that luteolin had a markedly protective effect on acute liver injury induced by LPS in mice by inhibiting the TXNIP-NLRP3 axis. Luteolin inhibits NLRP3 inflammasome activation by suppressing TXNIP, apoptosis associated speck-like protein containing a CARD domain (ASC), caspase-1, interleukin-1β (IL-1β) and IL-18 to reduce liver injury. In addition, luteolin inhibits LPS-induced liver inflammation by inhibiting the production of inflammation-related gene tumor necrosis factor-α (TNF-α), IL-10, and IL-6. What's more, luteolin alleviated LPS-induced hepatocyte injury by inhibiting oxidative stress and regulating MDA, SOD, and GSH levels. However, the protective effect of luteolin on acute LPS-induced liver injury in mice was blocked by si-TXNIP in vitro. These combined data showed that luteolin may alleviate LPS-induced liver injury through the TXNIP-NLPR3 axis, providing new therapeutic targets and therapeutic drugs for subsequent studies.

Wang X ，Wang L ，Dong R ，Huang K ，Wang C ，Gu J ，Luo H ，Liu K ，Wu J ，Sun H ，Meng Q ... -  《-》

Biochanin A protects lipopolysaccharide/D-galactosamine-induced acute liver injury in mice by activating the Nrf2 pathway and inhibiting NLRP3 inflammasome activation.

Biochanin A, an isoflavone existed in red clover and peanuts, has been reported to possess a wide spectrum of pharmacological activities, such as anti-inflammatory and antioxidant effects. However, the protective effects and mechanism of biochanin A on liver injury have not been reported. In this study, acute liver injury was induced by intraperitoneal injection of lipopolysaccharide (LPS) and d-galactosamine (D-GalN). Biochanin A was administrated 1h prior to LPS/D-GalN challenge. Serum ALT, AST, IL-1β, and TNF-α levels, hepatic malondialdehyde (MDA), GPx, SOD, and Catalase contents, tissue histology, IL-1β, TNF-α, NLRP3, and Nrf2 expression were detected. The results showed that serum ALT, AST, IL-1β, and TNF-α levels and hepatic MDA content increased after LPS/GalN treatment. These changes were attenuated by biochanin A. Meanwhile, biochanin A dose-dependently up-regulated the expression of Nrf2 and HO-1. Biochanin A also inhibited hepatic IL-1β and TNF-α expression in a dose-dependent manner. Biochanin A did not inhibit LPS/D-GalN-induced hepatic NLRP3, ASC, and caspase-1 expression. However, the interaction of NLRP3 with ASC and caspase-1 were inhibited by biochanin A. In addition, LPS/D-GalN-induced up-regulation of thioredoxin-interacting protein (TXNIP) and interaction between TXNIP and NLRP3 were also inhibited by biochanin A. In conclusion, biochanin A protected against LPS/GalN-induced liver injury by activating the Nrf2 pathway and inhibiting NLRP3 inflammasome activation.

Liu X ，Wang T ，Liu X ，Cai L ，Qi J ，Zhang P ，Li Y ... -  《-》

NLRP3 inflammasome activation in D-galactosamine and lipopolysaccharide-induced acute liver failure: role of heme oxygenase-1.

D-Galactosamine (GalN) and lipopolysaccharide (LPS) are commonly used to study mechanisms of hepatic malfunction that result in hepatic inflammation and subsequent fulminant hepatic failure. Inflammasomes are intracellular multiprotein complexes that in response to cellular danger signals trigger the biological maturation of proinflammatory cytokines. Heme oxygenase-1 (HO-1) is a cytoprotective enzyme that induces anti-inflammatory and antioxidant activity against oxidative cellular stress. This study examined activation of the NACHT, LRR, and PYD domain-containing protein 3 (NLRP3) inflammasome in GalN/LPS-induced hepatic injury and the role of HO-1 in the signaling pathways of inflammasome. Mice (C57BL/6) were pretreated twice with hemin (HO-1 inducer, 30 mg/kg) and zinc protoporphyrin (ZnPP; HO-1 inhibitor, 10mg/kg) at 12 and 2h before GalN (800 mg/kg)/LPS (40 μg/kg) administration. HO-1 induction with hemin reversed the lethality induced by GalN/LPS administration, and ZnPP pretreatment blocked this change. Lipid peroxidation markedly increased after GalN/LPS treatment, whereas glutathione content decreased in the GalN/LPS group. These changes were attenuated by hemin, but ZnPP reversed the effects of hemin. Serum levels of tumor necrosis factor-α (TNF-α) and interleukin (IL)-1β increased after GalN/LPS treatment; these increases were attenuated by hemin. Hepatic mRNA levels of TNF-α, IL-1β, and NLRP3 increased after GalN/LPS treatment, and hemin attenuated increases in TNF-α and IL-1β. After GalN/LPS treatment, the hepatic expression of NLRP3, ASC, and caspase-1 (p10) was increased. In immunoprecipitation studies, hemin attenuated the interaction of NLRP3 with ASC and caspase-1. GalN/LPS induced expression of the thioredoxin-interacting protein (TXNIP) gene and the interaction between NLRP3 and TXNIP; again, hemin attenuated these effects. The effects of hemin were reversed by ZnPP. Our findings suggest that activation of the NLRP3 inflammasome leads to a GalN/LPS-induced inflammatory response through TXNIP-NLRP3 interaction. Furthermore, HO-1 overexpression may protect the liver against GalN/LPS-induced inflammation through suppression of the NLRP3 signaling pathway.

Kim SJ ，Lee SM 《-》

Melatonin alleviates cadmium-induced liver injury by inhibiting the TXNIP-NLRP3 inflammasome.

Cadmium (Cd) is a persistent environmental and occupational contaminant that accumulates in the liver and induces oxidative stress and inflammation. Melatonin possesses potent hepatoprotective properties against the development and progression of acute and chronic liver injury. Nevertheless, the molecular mechanism underlying the protective effects of melatonin against Cd-induced hepatotoxicity remains obscure. In this study, we aimed to investigate the effects of melatonin on Cd-induced liver inflammation and hepatocyte death. Male C57BL/6 mice were intraperitoneally injected with melatonin (10 mg/kg) once a day for 3 days before exposure to CdCl2 (2.0 mg/kg). We found that Cd induced hepatocellular damage and inflammatory infiltration as well as increased serum ALT/AST enzymes. In addition, we showed that Cd triggered an inflammatory cell death, which is mediated by the NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome. Moreover, melatonin treatment significantly alleviated Cd-induced liver injury by decreasing serum ALT/AST levels, suppressing pro-inflammatory cytokine production, inhibiting NLRP3 inflammasome activation, ameliorating oxidative stress, and attenuating hepatocyte death. Most importantly, melatonin markedly abrogated Cd-induced TXNIP overexpression and decreased the interaction between TXNIP and NLRP3 in vivo and in vitro. However, treatment with siRNA targeting TXNIP blocked the protective effects of melatonin in Cd-treated primary hepatocytes. Collectively, our results suggest that melatonin confers protection against Cd-induced liver inflammation and hepatocyte death via inhibition of the TXNIP-NLRP3 inflammasome pathway.

Cao Z ，Fang Y ，Lu Y ，Tan D ，Du C ，Li Y ，Ma Q ，Yu J ，Chen M ，Zhou C ，Pei L ，Zhang L ，Ran H ，He M ，Yu Z ，Zhou Z ... -  《-》

CORM-2 inhibits TXNIP/NLRP3 inflammasome pathway in LPS-induced acute lung injury.

Jiang L ，Fei D ，Gong R ，Yang W ，Yu W ，Pan S ，Zhao M ，Zhao M ... -  《-》