Regulation of transcriptional states in acute liver failure by microbiome
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ABSTRACT: We performed single cell RNAseq of liver cells in acute liver failure model in mice with different microbiome states to unravel cellular changes in the disease and the impact of gut microbiota on the physiology in this disease.
Project description:The well-known difference in sensitivity of mice and rats to acetaminophen (APAP) liver injury has been related to differences in the fraction that is bioactivated to the reactive metabolite N-acetyl-p-benzoquinoneimine (NAPQI). Physiologically-based pharmacokinetic modelling was used to identify doses of APAP (300 and 1000 mg/kg in mice and rats, respectively) yielding similar hepatic burdens of NAPQI, to enable the comparison of temporal liver tissue responses under conditions of equivalent chemical insult.
Project description:Genetic disruption of thioredoxin reductase 1 protects against acetaminophen (APAP) toxicity. To determine the role of the thioredoxin system on xenobiotic metabolism we challeneged wildtype and txnrd1liver-null mice with acetaminophen. Adult male wildtype and txnrd1 liver-null mice (C57BL6/J) were treated with either saline (PBS) or 100mg/kg APAP. Liver RNA was harvested eight hours after challenge and processed for microarray analysis. Comparison of 2 treatment conditions in 2 genotypes, biological replicates in triplicate.
Project description:Acute cognitive impairment (i.e., delirium) is common in elderly emergency department patients and frequently results from infections that are unrelated to the central nervous system. Since activation of the peripheral innate immune system induces brain microglia to produce inflammatory cytokines that are responsible for behavioral deficits, we investigated if aging exacerbated neuroinflammation and sickness behavior after peripheral injection of lipopolysaccharide (LPS). Microarray analysis revealed a transcriptional profile indicating the presence of primed or activated microglia and increased inflammation in the aged brain. Furthermore, aged mice had a unique gene expression profile in the brain after an intraperitoneal injection of LPS, and the LPS-induced elevation in the brain inflammatory cytokines and oxidative stress was both exaggerated and prolonged compared with adults. Aged mice were anorectic longer and lost more weight than adults after peripheral LPS administration. Moreover, reductions in both locomotor and social behavior remained 24 h later in aged mice, when adults had fully recovered, and the exaggerated neuroinflammatory response in aged mice was not reliably paralleled by increased circulating cytokines in the periphery. Taken together these data establish that activation of the peripheral innate immune system leads to exacerbated neuroinflammation in the aged as compared with adult mice. This dysregulated link between the peripheral and central innate immune system is likely to be involved in the severe behavioral deficits that frequently occur in older adults with systemic infections. Experiment Overall Design: In this study, adult and aged mice were injected intraperitoneal with sterile saline or Escherichia coli LPS (0.33 mg/kg, ~10 µg/mouse; serotype 0127:B8, Sigma). This dosage of LPS was used because it induces a mild transient sickness behavior in young adults. Mice were killed 4 h after saline or LPS injection by CO2 asphyxiation. Blood samples were collected and brains were removed, separated in half at the longitudinal fissure, frozen in liquid nitrogen, and stored (-80°C) until assaying. Total RNA was later isolated from some brain samples for microarray analysis (n=3).
Project description:Persistent liver injury triggers a fibrogenic program that causes pathologic remodelling of the hepatic microenvironment (i.e., liver fibrosis) and portal hypertension. The dynamics of gene regulation during liver disease progression and regression remain understudied. Here, we generated hepatic transcriptome profiles in two well-established liver disease models at peak fibrosis and during spontaneous regression after the removal of the inducing agents. We linked the dynamics of key liver disease readouts, such as portal pressure, collagen proportionate area, and transaminase serum levels, to most differentially expressed genes, enabling the identification of transcriptomic signatures of progressive vs. regressive liver fibrosis and portal hypertension. These candidate biomarkers (e.g., Scube1, Tcf4, Src, Hmga1, Trem2, Mafk, Mmp7) were also validated in RNA-seq datasets of patients with cirrhosis and portal hypertension. Finally, deconvolution analysis identified major cell types and suggested an association of macrophage and portal hepatocyte signatures with portal hypertension and fibrosis area in both models.
Project description:Purpose : Identification of novel microRNA biomarkers in urine and plasma from rats with kidney or liver damage micoRNA-SEQ was used to analyze changes in miRNA profiles of tissue, plasma and urine samples of rats treated with either a nephrotoxicant (cisplatin) or one of two hepatotoxicants (Acetaminophen [APAP] or Carbon Tetrachloride [CCL4]).
Project description:In order to confirm the role of fatty acid β-oxidation in Src regulation, we performed gene expression analysis in MDA231 cells from in vivo model treated with ETX or knockdown of CPT1 or CPT2 using shRNA. As expected, inhibition of β-oxidation showed a gene expression pattern that is opposite to the published Src regulated gene pattern. The known Src up-regulated genes are down-regulated and Src down-regulated genes are up-regulated in β-oxidation inhibited cells. Western Blotting further confirmed the gene expression pattern. Knockdown of CPT1 or CPT2 inhibited Src Y416 autophosphorylation as observed with ETX. MDA231 cells were treated with ETX or knockdown of CPT1 or CPT2 using shRNA. Gene expression profiles were taken for each group and compared with control group (shRNA scramble). Multiple group comparison [MDA231-Scramble (C), MDA231-Scramble +ETX (D), MDA231-shCPT-1 (E) and MDA231-shCPT-2 (F)]
Project description:Study was performed to improve understanding of erythropoiesis (EP) induced by acute anemia in Atlantic salmon. Fish was injected with a low dose of hemolytic compound phenylhydrazine (PHZ). Treatment resulted in moderate but significant reduction of hematocrit (Hct) and increased transcription of cardiac erythropoietin (epo) at 2 days post challenge (dpc), and epo receptor (epor) in spleen from 2 to 4 dpc. Oligonucleotide microarrays were used to characterize the events of EP in the spleen. These results were compared to gene expression profiles of untreated mature red blood cells (RBC) in order to search for erythroid-specific genes. Splenic responses suggested a prevalence of protective mechanisms at the first stage, characterized by induced xenobiotic metabolism and responses to oxidative and protein stress. Erythroid-specific regulation was evident at 2 dpc and enhanced by 4 dpc, and gene expression profiles witnessed a rapid establishment of RBC phenotype although Hct levels remained low. A large group of genes showed a strong correlation to globins by expression profiles. In addition to epor this included genes of heme and iron metabolism, scavengers of free radicals and chaperones, channels and transporters, markers of erythrocytes, regulators of proliferation and cell cycle arrest and many genes with unidentified roles in RBC differentiation. Induced EP in spleen was characterized by specific features, such as upregulation of virus-responsive genes and sustained high expression of proapoptotic genes including caspases. Transcriptome changes suggested an association between EP and suppression of several developmental programs including adaptive immune responses. In conclusion, acute hemolysis and resulting anemia rapidly induced EP in the spleen of Atlantic salmon, which showed both common characteristics for all vertebrates as well as fish-specific properties. Atlantic salmon was injected with a single dose of PHZ (6 mg/kg body mass) or saline. Spleen samples for microarray analyses were collected after 2 and 4 days. Additonally, red blood cells (RBC) were compared with spleen
Project description:Effect of vehicle vs non-toxic and toxic paracetamol (151mg/kg and 529mg/kg) doses on the gene expression profile at 1, 4 and 24h in murine liver.
Project description:RNA-seq analysis was performed using RNA isolated from three tumor models (GL261 glioma, LLC Lewis lung carcinoma, B16F10 melanoma) implanted subcutaneousy in C57BL/6 mice, or in ICR scid mice. Mice were untreated or were treated with cyclophosphamide (CPA) given on a 6-day repeating metronomic schedule (CPA/6d), except as noted. Results from these global transcriptome analysis indicated substantial elevation of basal GL261 immune infiltration and strong activation by CPA/6d treatment of GL261 immune stimulatory pathways and their upstream regulators, but without preferential depletion of negative immune regulators compared to LLC and B16F10 tumors. In LLC tumors, where CPA/6d treatment was found to be anti-angiogenic, CPA/6d suppressed VEGFA target genes and down regulated cell adhesion and leukocyte transendothelial migration genes. In GL261 tumors implanted in adaptive immune-deficient scid mice, where CPA/6d-induced GL261 regression is incomplete and late tumor growth rebound can occur, T cell receptor signaling and certain cytokine-cytokine receptor responses seen in B6 mice were deficient. Extending the CPA treatment interval from 6 to 9 days (CPA/9d) â which results in a strong but transient natural killer cell response followed by early tumor growth rebound â induced fewer cytokines and increased expression of drug metabolism genes. Taken together, these findings elucidate molecular response pathways activated by intermittent metronomic CPA treatment and identify deficiencies that characterize immune-unresponsive tumor models and drug schedules. RNA isolated from various tumor cell lines implanted s.c in C57BL/6 mice or scid mice, untreated or treated with cyclophosphamide (CPA) given on a metronomic schedule, were prepared and used for stranded or unstranded RNA-seq.
Project description:Gamma-secretase inhibitors (GSIs), which block the activation of NOTCH receptors, are being tested in the treatment of T-cell acute lymphoblastic leukemia (T-ALL). Thus far, limited antileukemic cytotoxicity and severe gastrointestinal toxicity have restricted the clinical application of these targeted drugs. Here we show that combination therapy with GSIs plus glucocorticoids can improve the antileukemic effects of GSIs and reduce their gut toxicity in vivo. Inhibition of NOTCH1 signaling in glucocorticoid-resistant T-ALL restored glucocorticoid receptor auto-up-regulation and induced apoptotic cell death through induction of BIM expression. Additionally, cotreatment with glucocorticoids induced Ccnd2 upregulation in the gut which protected mice from the intestinal secretory metaplasia typically induced by loss of NOTCH signaling. These results support a role for glucocorticoids plus GSIs in the treatment of glucocorticoid-resistant T-ALL. Experiment Overall Design: Experiments analyzing the interacition of dexamethasone and the gamma-secretase inhibitor DBZ were carried out in 6-week-old C57/Black6 female mice (Jackson Laboratory). In these studies we treated mice with vehicle (DMSO) (n=2), dexamethasone (15 mg/kg) (n=2), DBZ (10 micromol/kg) (n=2) and dexamethasone (15 mg/kg) plus DBZ (10 micromol/kg) (n=2) daily by intraperitoneal injection for 5 days. At the end of the treatment, animals were euthanized and segments of the small intestine were collected and processed for RNA extraction, histological and immunohistochemical analysis.