Project description:Background and aims: We aimed to study the pathogenesis of AH in an animal model of acute-on-chronic alcoholic liver disease which combines chronic hepatic fibrosis with intragastric alcohol administration. Methods: Adult male C57BL6/J mice were treated with CCl4 (0.2 ml/kg, 2×weekly by intraperitoneal injections for 6 weeks) to induce chronic liver fibrosis. Then, ethyl alcohol (EtOH) (up to 25 g/kg/day, for 3 weeks) was administered continuously to mice via a gastric feeding tube, with or without one-half dose of CCl4. Liver and serum markers were evaluated to characterize acute-on-chronic-alcoholic liver disease in our model. Results: CCl4 or EtOH treatment alone induced liver fibrosis or steatohepatitis, respectively, findings that were consistent with expected pathology. Combined treatment with CCl4 and EtOH resulted in a marked exacerbation of liver injury, as evident by the development of hepatic inflammation, marked steatosis, and pericellular fibrosis, and by increased serum transaminase levels, compared to mice treated with either treatment alone. Liver transcriptomic changes specific to combined treatment group demonstrated close concordance with pathways perturbed in human severe cases of AH. In addition to gene expression changes, E. coli and Candida species were also significantly more abundant in livers of mice co-treated with CCl4 and EtOH. Conclusions: Mice treated with CCl4 and EtOH displayed several key characteristics of human AH, including pericellular fibrosis, increased hepatic bacterial load, and dysregulation of the same molecular pathways. This model may be useful for developing therapeutics for AH.
Project description:Compared to whole serum miRNAs, miRNAs in serum small extracellular vesicles (sEVs) are well protected form RNA enzymes, thus provide a consistent source of miRNA for disease biomarker detection. Serum sEVs and their miRNA cargos released by injured liver cells could be promising biomarkers for diagnosis of liver diseases. We were very interested to find out the effects of liver injury on serum extracellular vesicles as well as the small RNA components they transported, if there is any difference between acute and chronic injury. Study in this regard will help us to identify new serum biomarkers for liver injury, and to find out if there are specific markers for acute or chronic liver injury. To identify potential biomarker for liver injury based on serum sEVs miRNAs, we established the carbon tetrachloride (CCL4) induced acute and chronic liver injury mice model, and examined the dynamic changes of small RNA components, especially miRNAs, in serum sEVs.
Project description:Background and aims: Liver is a major target organ for alcohol-induced disease and the spectrum of pathological states elicited by alcohol in liver comprises steatosis, alcoholic steatohepatitis, progressive fibrosis and cirrhosis, conditions that may progress to hepatocellular carcinoma. Many experimental animal models of alcoholic steatohepatitis exist that vary in duration, mode of alcohol administration and the degree and types of liver injury produced. While most of these models, regardless whether alcohol is administered through liquid diet or intragastrically, produce steatohepatitis and mild fibrosis, it is widely acknowledged that these models fail to fully recapitulate key characteristics of severe forms of alcoholic liver disease, such as alcoholic hepatitis. Recent studies attempted to combine alcohol and fibrosis and achieved promising results in mouse models that achieve some of the key features of alcoholic liver disease accompanied by exacerbated fibrosis and acute renal injury. This study combined a chronic cholestatic liver fibrosis model induced by 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) with a mouse model of intragastric alcohol feeding. Methods: Adult male C57BL6/J mice were treated with 3,5-diethoxycarbonyl-1,4-dihydrocolidine (DDC) containing diet (0.05% w/w) to induce chronic liver fibrosis. Following DDC-induced fibrogenesis, ethyl alcohol (EtOH) (up to 27 g/ kg/day, up to 28 days) was administered continuously to mice via a gastric feeding tube (Tsukamoto-Frenchmodel of alcoholic liver disease). Results: Exposure to DDC or EtOH alone resulted in liver fibrosis or steatosis, respectively. Combined treatment with DDC and EtOH lead to an additive effect on liver injury, as evident by the development of hepatic inflammation, steatosis, and pericellular fibrosis, and by increased serum transaminase levels, compared to mice treated with either agent alone. Liver transcriptomic changes specific to combined treatment group included pathways involved in the cell cycle and DNA damage. Analyses of feces from these mice revealed alcohol-associated changes to the bile acid profile and gut microbiome. Conclusions: Mice treated with DDC and EtOH displayed several key characteristics of human alcoholic hepatitis, including pericellular fibrosis, increased hepatic bacterial load with dysbiosis, reduced capacity of the microbiome to synthesize secondary bile acids.
Project description:Molecular profiling of infiltrating monocyte-derived macrophages versus resident kupffer cells following acute liver injury The liver has a remarkable capacity to regenerate after injury; yet, the role of macrophages (MF) in this process remains controversial mainly due to difficulties in distinguishing between different MF-subsets. Here, we utilized a murine model of acute liver injury caused by overdose of acetaminophen (APAP) and defined three distinct MF subsets that populate the liver following injury. Accordingly, resident Kupffer cells (KC) were significantly reduced upon APAP-challenge and started recovering by self-renewal at resolution phase without contribution of circulating Ly6Chi monocytes. The latter were recruited in a CCR2 and M-CSF mediated pathway at the necro-inflammatory phase and differentiated into ephemeral Ly6Clo MF subset at resolution phase. Moreover, their inducible ablation resulted in impaired recovery. Microarray based molecular profiling uncovered high similarity between steady state KC and those recovered at the resolution phase. In contrast, KC and monocyte-derived MF displayed distinct pro-restorative genetic signature at the resolution phase. Finally, we show that infiltrating monocytes acquire a pro-restorative polarization manifested by unique expression of pro-angiogenesis mediators and genes involved with inhibition of neutrophil activity and recruitment and promotion of their clearance. Collectively, our results present a novel phenotypic, ontogenic and molecular definition of liver-MF compartment following acute injury. 11 Samples (arrays) were performed. We generated pairwise comparison between all the different macrophages stages, using Partek Genomics Suite. Genes with p?5%[FDR] and a fold-change difference of ?2 or <-2 were selected.
Project description:Our team has constructed a prediction model based on the expression level of immune factors (PD-L1, PD-1, CTLA4, Siglec15) to predict the chronicization of radiation-induced acute intestinal injury (RAII) and verified the predictive efficacy of the system in retrospective studies. This clinical study intends to further prospectively verify the accuracy of this prediction model in rectal cancer patients. In this study, we plan to enroll 200 patients diagnosed with locally advanced rectal cancer by pathology and MRI, who undergo neoadjuvant chemoradiotherapy (NCRT) and total mesorectal excision (TME) and develop RAII during NCRT or within 1 month. We will follow up the occurrence and progression of radiation-induced intestinal injury within 1 year after TME. Expression levels of immune factors will be detected in pathological tissue after TME and applied to the prediction model to predict the chronicization of RAII. Based on the clinical diagnosis of chronic radiation-induced intestinal injury, the area under curve (AUC), accuracy, precision, specificity, and sensitivity of this prediction model in predicting the chronicization of RAII will be evaluated. The main outcome hypothesis is that the AUC of chronicization of RAII predicted by the prediction model based on the expression level of immune factors is more than 0.8.
Project description:Transcriptional alterations during different stages of hepatic stellate cell activation were determined using RNA Sequencing. Models include acute liver injury (1 injection of CCl4) and chronic liver injury (8 injections of CCl4 over 4-week period) with different recovery timepoints. Illumina NextSeq 500 High was used for sequencing.
Project description:Acute liver injury is a critical life-threatening event. Common causes are infections, intoxication, and ischemic conditions. The cytokine Interleukin 22 (IL-22) has been implicated in this process. However, the role of IL-22 during acute liver damage is controversial, since both protective and pathogenic properties have been reported. IL-22 binding protein (IL-22BP, IL-22Ra2), a soluble endogenous inhibitor of IL-22, is able to regulate IL-22 activity, and thus might explain some of the controversial findings. Since the role of IL-22BP in liver injury is unknown, we used Il22bp deficient mice and mouse models for acute liver damage to address this point. We found that Il22bp deficient mice were more susceptible to ischemia- and acetaminophen- induced liver damage. Deficiency of Il22bp caused increased hepatic damage and delayed liver regeneration. Using an unbiased approach, we found that IL-22, if uncontrolled in Il22bp deficient mice, induced Cxcl10 expression by hepatocytes, thereby recruiting inflammatory CD11b+Ly6C+ monocytes into the liver upon liver damage. Accordingly, neutralization of Cxcl10 reversed the increased disease susceptibility of Il22bp deficient mice. In conclusion, our data suggest dual functions of IL-22 in acute liver damage, and highlight the need to control IL-22 activity via IL-22BP.
Project description:We identify a new phase of functional compensation following acute liver injury that occurs prior to cellular proliferation. By coupling single-cell RNA-seq with in situ transcriptional analyses in two independent murine liver injury models, we discover adaptive reprogramming to ensure expression of both injury response and core liver function genes dependent on macrophage-derived WNT/b-catenin signaling. Interestingly, transcriptional compensation is most prominent in non-proliferating cells, clearly delineating two separate phases of liver recovery. Overall, our work describes a new mechanism by which the liver maintains essential physiological functions prior to cellular reconstitution and characterizes macrophage-derived WNT signals required for this compensation.