LPS-TLR4 pathway exaggerates alcoholic hepatitis via provoking NETs formation / La vía LPS-TLR4 exagera la hepatitis alcohólica al provocar la formación de NET

Background Intrahepatic infiltration of neutrophils is a character of alcoholic hepatitis (AH) and neutrophil extracellular traps (NETs) are an important strategy for neutrophils to fix and kill invading microorganisms. The gut-liver axis has been thought to play a critical role in many liver diseases also including AH. However, whether NETs appear in AH and play role in AH is still unsure. Methods Serum samples from AH patients were collected and LPS and MPO-DNA were detected. WT, NE KO, and TLR4 KO mice were used to build the AH model, and the intestinal bacteria were eliminated at the same time and LPS was given. Then the formation of NETs and AH-related markers were detected. Results The serum MPO-DNA and LPS concentration was increased in AH patients and a correlation was revealed between these two indexes. More intrahepatic NETs formed in AH mice. NETs formation decreased with antibiotic intervention and restored with antibiotic intervention plus LPS supplement. While NETs formation failed to change with gut microbiome or combine LPS supplement in TLR4 KO mice. As we tested AH-related characters, liver injury, intrahepatic fat deposition, inflammation, and fibrosis alleviated with depletion of NE. These related marks were also attenuated with gut sterilization by antibiotics and recovered with a combined treatment with antibiotics plus LPS. But the AH-related markers did show a difference in TLR4 KO mice when they received the same treatment. Conclusion Intestinal-derived LPS promotes NETs formation in AH through the TLR4 pathway and further accelerates the AH process by NETs (AU)

Antecedentes La infiltración intrahepática de neutrófilos es una característica de la hepatitis alcohólica (AH, por sus siglas en inglés) y las trampas extracelulares de neutrófilos (NET, por sus siglas en inglés) son una estrategia importante para que los neutrófilos fijen y maten microorganismos invasores. Se ha pensado que el eje intestino/hígado desempeña un papel crítico en muchas enfermedades hepáticas, incluida la AH. Sin embargo, aún no está claro si las NET aparecen en la AH y desempeñan un papel en la misma. Métodos Se recogieron muestras de suero de pacientes con AH, y se detectaron LPS y MPO-ADN. Se utilizaron ratones WT, NE KO y TLR4 KO para construir el modelo de la AH, y las bacterias intestinales se eliminaron al mismo tiempo y se administró LPS. Luego se detectó la formación de NET y los marcadores relacionados con la AH. Resultados La concentración sérica de MPO-ADN y LPS aumentó en los pacientes con HA, y se reveló una correlación entre estos 2 índices. Se formaron más NET intrahepáticos en ratones con AH. La formación de las NET disminuyó con la intervención antibiótica, y se restauró con la intervención antibiótica más suplemento de LPS. Mientras que la formación de NET no pudo cambiar con el microbioma intestinal o combinar el suplemento de LPS en ratones TLR4 KO. A medida que probamos los caracteres relacionados con la AH, la lesión hepática, la deposición de grasa intrahepática, la inflamación y la fibrosis se aliviaron con el agotamiento de las NET. Estas marcas relacionadas también se atenuaron con la esterilización intestinal con antibióticos, y se recuperaron con un tratamiento combinado con antibióticos más LPS. Pero los marcadores relacionados con la AH mostraron una diferencia en los ratones TLR4 KO cuando recibieron el mismo tratamiento. Conclusión El LPS de origen intestinal promueve la formación de NET en la AH a través de la vía TLR4, y acelera aún más el proceso de AH por NET (AU)

LPS-TLR4 pathway exaggerates alcoholic hepatitis via provoking NETs formation.

BACKGROUND: Intrahepatic infiltration of neutrophils is a character of alcoholic hepatitis (AH) and neutrophil extracellular traps (NETs) are an important strategy for neutrophils to fix and kill invading microorganisms. The gut-liver axis has been thought to play a critical role in many liver diseases also including AH. However, whether NETs appear in AH and play role in AH is still unsure. METHODS: Serum samples from AH patients were collected and LPS and MPO-DNA were detected. WT, NE KO, and TLR4 KO mice were used to build the AH model, and the intestinal bacteria were eliminated at the same time and LPS was given. Then the formation of NETs and AH-related markers were detected. RESULTS: The serum MPO-DNA and LPS concentration was increased in AH patients and a correlation was revealed between these two indexes. More intrahepatic NETs formed in AH mice. NETs formation decreased with antibiotic intervention and restored with antibiotic intervention plus LPS supplement. While NETs formation failed to change with gut microbiome or combine LPS supplement in TLR4 KO mice. As we tested AH-related characters, liver injury, intrahepatic fat deposition, inflammation, and fibrosis alleviated with depletion of NE. These related marks were also attenuated with gut sterilization by antibiotics and recovered with a combined treatment with antibiotics plus LPS. But the AH-related markers did show a difference in TLR4 KO mice when they received the same treatment. CONCLUSION: Intestinal-derived LPS promotes NETs formation in AH through the TLR4 pathway and further accelerates the AH process by NETs.

Gut-derived lipopolysaccharide promotes alcoholic hepatosteatosis and subsequent hepatocellular carcinoma by stimulating neutrophil extracellular traps through toll-like receptor 4.

BACKGROUND/AIMS: Binge drinking leads to many disorders, including alcoholic hepatosteatosis, which is characterized by intrahepatic neutrophil infiltration and increases the risk of hepatocellular carcinoma (HCC). Molecular mechanisms may involve the migration of bacterial metabolites from the gut to the liver and the activation of neutrophil extracellular traps (NETs). METHODS: Serum samples from both binge drinking and alcohol-avoiding patients were analyzed. Mouse models of chronic plus binge alcohol-induced hepatosteatosis and HCC models were used. RESULTS: A marker of NETs formation, lipopolysaccharide (LPS), was significantly higher in alcoholic hepatosteatosis and HCC patients and mice than in controls. Intrahepatic inflammation markers and HCC-related cytokines were decreased in mice with reduced NET formation due to neutrophil elastase (NE) deletion, and liver-related symptoms of alcohol were also alleviated in NE knockout mice. Removal of intestinal bacteria with antibiotics led to decreases in markers of NETs formation and inflammatory cytokines upon chronic alcohol consumption, and development of alcoholic hepatosteatosis and HCC was also attenuated. These functions were restored upon supplementation with the bacterial product LPS. When mice lacking toll-like receptor 4 (TLR4) received chronic alcohol feeding, intrahepatic markers of NETs formation decreased, and hepatosteatosis and HCC were alleviated. CONCLUSION: Formation of NETs following LPS stimulation of TLR4 upon chronic alcohol use leads to increased alcoholic steatosis and subsequent HCC.