Project description:The Murine Sepsis Score (MSS) is used to assess the severity of sepsis in rats and mice based on observational characteristics. The quantitative variables of glycemia, body weight, and temperature are predictors of severity in experimental models of sepsis. Therefore, our study sought to adapt the MSS with the same variables to indicate earlier the severity of the disease in murine models of the disease. Sepsis mice presented hypoglycemia, weight loss, and hypothermia. Therefore, these variables were included in the Adapted Murine Sepsis Score (A-MSS). The A-MASS presented 100% specificity and 87.5% sensibility been able to differentiate the early sepsis symptoms and its severity. The A-MSS allows an early and more complete diagnosis of sepsis in mice and might be considered as a procedure to improve the analysis of systemic sepsis dysfunction in murine experimental models.
Project description:Cannabidiol (CBD) (25 mg/kg peroral) treatment was shown to improve metabolic outcomes in ovariectomized (OVX) mice deficient in 17β-estradiol (E2). Herein, CBD effects on intestinal and hepatic bile acids (BAs) and inflammation were investigated. Following RNA sequencing of colon tissues from vehicle (VEH)- or CBD-treated sham surgery (SS) or OVX mice (n = 4 per group), differentially expressed genes (DEGs) were sorted in ShinyGO. Inflammatory response and bile secretion pathways were further analyzed. Colon content and hepatic BAs were quantified by LC-MS (n = 8-10 samples/group). Gut organoids were treated with CBD (100, 250, 500 µM) with or without TNFα and lipopolysaccharide (LPS) followed by mRNA extraction and qPCR to assess CBD-induced changes to inflammatory markers. The expression of 78 out of 114 inflammatory response pathway genes were reduced in CBD-treated OVX mice relative to vehicle (VEH)-treated OVX mice. In contrast, 63 of 111 inflammatory response pathway genes were increased in CBD-treated sham surgery (SS) mice compared to VEH-treated SS group and 71 of 121 genes were increased due to ovariectomy. CBD did not alter BA profiles in colon content or liver. CBD repressed Tnf and Nos2 expression in intestinal organoids in a dose-dependent manner. In conclusion, CBD suppressed colonic inflammatory gene expression in E2-deficient mice but was pro-inflammatory in E2-sufficient mice suggesting CBD activity in the intestine is E2-dependent.
Project description:BackgroundMechanical ventilation could lead to ventilator-induced lung injury (VILI), but its underlying pathogenesis remains largely unknown. In this study, we aimed to determine the genes which were highly correlated with VILI as well as their expressions and interactions by analyzing the differentially expressed genes (DEGs) between the VILI samples and controls.MethodsGSE11434 was downloaded from the gene expression omnibus (GEO) database, and DEGs were identified with GEO2R. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were conducted using DAVID. Next, we used the STRING tool to construct protein-protein interaction (PPI) network of the DEGs. Then, the hub genes and related modules were identified with the Cytoscape plugins: cytoHubba and MCODE. qRT-PCR was further used to validate the results in the GSE11434 dataset. We also applied gene set enrichment analysis (GSEA) to discern the gene sets that had a significant difference between the VILI group and the control. Hub genes were also subjected to analyses by CyTargetLinker and NetworkAnalyst to predict associated miRNAs and transcription factors (TFs). Besides, we used CIBERSORT to detect the contributions of different types of immune cells in lung tissues of mice in the VILI group. By using DrugBank, small molecular compounds that could potentially interact with hub genes were identified.ResultsA total of 141 DEGs between the VILI group and the control were identified in GSE11434. Then, seven hub genes were identified and were validated by using qRT-PCR. Those seven hub genes were largely enriched in TLR and JAK-STAT signaling pathways. GSEA showed that VILI-associated genes were also enriched in NOD, antigen presentation, and chemokine pathways. We predicted the miRNAs and TFs associated with hub genes and constructed miRNA-TF-gene regulatory network. An analysis with CIBERSORT showed that the proportion of M0 macrophages and activated mast cells was higher in the VILI group than in the control. Small molecules, like nadroparin and siltuximab, could act as potential drugs for VILI.ConclusionIn sum, a number of hub genes associated with VILI were identified and could provide novel insights into the pathogenesis of VILI and potential targets for its treatment.
Project description:BackgroundBloodstream infections with antibiotic-resistant Pseudomonas aeruginosa are common and increasingly difficult to treat. Pyocins are naturally occurring protein antibiotics produced by P. aeruginosa that have potential for human use.ObjectivesTo determine if pyocin treatment is effective in a murine model of sepsis with P. aeruginosa.MethodsRecombinant pyocins S5 and AP41 were purified and tested for efficacy in a Galleria mellonella infection model and a murine model of P. aeruginosa sepsis.ResultsBoth pyocins produced no adverse effects when injected alone into mice and showed good in vitro antipseudomonal activity. In an invertebrate model of sepsis using G. mellonella, both pyocins significantly prolonged survival from 1/10 (10%) survival in controls to 80%-100% survival among groups of 10 pyocin-treated larvae. Following injection into mice, both showed extensive distribution into different organs. When administered 5 h after infection, pyocin S5 significantly increased survival from 33% (2/6) to 83% (5/6) in a murine model of sepsis (difference significant by log-rank test, P < 0.05).ConclusionsPyocins S5 and AP41 show in vivo biological activity and can improve survival in two models of P. aeruginosa infection. They hold promise as novel antimicrobial agents for treatment of MDR infections with this microbe.
Project description:BackgroundSepsis is a condition with high mortality and morbidity, characterized by deregulation of the immune response against the pathogen. Current treatment strategies rely mainly on antibiotics and supportive care. However, there is growing interest in exploring cell-based therapies as complementary approaches. Human liver stem cells (HLSCs) are pluripotent cells of mesenchymal origin, showing some advantages compared to mesenchymal stem cells in terms of immunomodulatory properties. HSLC-derived extracellular vesicles (EVs) exhibited a superior efficacy profile compared to cells due to their potential to get through biological barriers and possibly to avoid tumorigenicity and showed to be effective in vivo and ex vivo models of liver and kidney disease. The potential of HLSCs and their EVs in recovering damage to distal organs due to sepsis other than the kidney remains unknown. This study aimed to investigate the therapeutic potential of the intravenous administration of HSLCs or HSLCs-derived EVs in a murine model of sepsis.ResultsSepsis was induced by caecal ligation and puncture (CLP) on C57/BL6 mice. After CLP, mice were assigned to receive either normal saline, HLSCs or their EVs and compared to a sham group which underwent only laparotomy. Survival, persistence of bacteraemia, lung function evaluation, histology and bone marrow analysis were performed. Administration of HLSCs or HLSC-EVs resulted in improved bacterial clearance and lung function in terms of lung elastance and oedema. Naïve murine hematopoietic progenitors in bone marrow were enhanced after treatment as well. Administration of HLSCs and HLSC-EVs after CLP to significantly improved survival.ConclusionsTreatment with HLSCs or HLSC-derived EVs was effective in improving acute lung injury, dysmyelopoiesis and ultimately survival in this experimental murine model of lethal sepsis.
Project description:Oxidative mitochondrial damage is closely linked to inflammation and cell death, but low levels of reactive oxygen and nitrogen species serve as signals that involve mitochondrial repair and resolution of inflammation. More specifically, cytoprotection relies on the elimination of damaged mitochondria by selective autophagy (mitophagy) during mitochondrial quality control. This aim of this study was to identify and localize mitophagy in the mouse lung as a potentially upregulatable redox response to Staphylococcus aureus sepsis. Fibrin clots loaded with S. aureus (1×10(7) CFU) were implanted abdominally into anesthetized C57BL/6 and B6.129X1-Nfe2l2tm1Ywk/J (Nrf2(-/-)) mice. At the time of implantation, mice were given vancomycin (6mg/kg) and fluid resuscitation. Mouse lungs were harvested at 0, 6, 24, and 48h for bronchoalveolar lavage (BAL), Western blot analysis, and qRT-PCR. To localize mitochondria with autophagy protein LC3, we used lung immunofluorescence staining in LC3-GFP transgenic mice. In C57BL/6 mice, sepsis-induced pulmonary inflammation was detected by significant increases in mRNA for the inflammatory markers IL-1β and TNF-α at 6 and 24h, respectively. BAL cell count and protein also increased. Sepsis suppressed lung Beclin-1 protein, but not mRNA, suggesting activation of canonical autophagy. Notably sepsis also increased the LC3-II autophagosome marker, as well as the lung׳s noncanonical autophagy pathway as evidenced by loss of p62, a redox-regulated scaffolding protein of the autophagosome. In LC3-GFP mouse lungs, immunofluorescence staining showed colocalization of LC3-II to mitochondria, mainly in type 2 epithelium and alveolar macrophages. In contrast, marked accumulation of p62, as well as attenuation of LC3-II in Nrf2-knockout mice supported an overall decrease in autophagic turnover. The downregulation of canonical autophagy during sepsis may contribute to lung inflammation, whereas the switch to noncanonical autophagy selectively removes damaged mitochondria and accompanies tissue repair and cell survival. Furthermore, mitophagy in the alveolar region appears to depend on activation of Nrf2. Thus, efforts to promote mitophagy may be a useful therapeutic adjunct for acute lung injury in sepsis.
Project description:Animal models of sepsis exhibit considerable variability in the temporal development of the physiologic response, which reduces the power of studies, particularly if interventions are tested at arbitrary time points. We developed a biotelemetry-based model of cecal ligation and puncture (CLP) that standardizes the testing of time-sensitive therapies to specific criteria of physiologic deterioration. In this study we seek to further define the variability in physiologic response to CLP sepsis and conduct a cost analysis detailing the potential for reducing animal usage. We have further characterized the variability in physiologic response after CLP in mice and determined peaks in the temporal distribution of points of physiologic decline. Testing therapies at physiologic thresholds reduces the variability found in historical fixed time-based models. Though initial cost is higher with biotelemetry, this is eventually offset by the significantly reduced number of mice needed to conduct physiologically relevant sepsis experiments.
Project description:BackgroundPericytes are vascular mural cells and are embedded in the basement membrane of the microvasculature. Recent studies suggest a role for pericytes in lipopolysaccharide (LPS)-induced microvascular dysfunction and mortality, but the mechanisms of pericyte loss in sepsis are largely unknown.MethodsBy using a cecal ligation and puncture (CLP)-induced murine model of sepsis, we observed that CLP led to lung and renal pericyte loss and reduced lung pericyte density and pericyte/endothelial cell (EC) coverage.ResultsUp-regulated Friend leukemia virus integration 1 (Fli-1) messenger ribonucleic acid (RNA) and protein levels were found in lung pericytes from CLP mice in vivo and in LPS-stimulated lung pericytes in vitro. Knockout of Fli-1 in Foxd1-derived pericytes prevented CLP-induced pericyte loss, vascular leak, and improved survival. Disrupted Fli-1 expression by small interfering RNA inhibited LPS-induced inflammatory cytokines and chemokines in cultured lung pericytes. Furthermore, CLP-induced pericyte pyroptosis was mitigated in pericyte Fli-1 knockout mice.ConclusionsOur findings suggest that Fli-1 is a potential therapeutic target in sepsis.
Project description:BackgroundBacterial invasion during sepsis induces disregulated systemic responses that could lead to fatal lung failure. The purpose of this study was to relate the temporal dynamics of gene expression to the pathophysiological changes in the lung during the first and second stages of E. coli sepsis in baboons.ResultsUsing human oligonucleotide microarrays, we have explored the temporal changes of gene expression in the lung of baboons challenged with sublethal doses of E. coli. Temporal expression pattern and biological significance of the differentially expressed genes were explored using clustering and pathway analysis software. Expression of selected genes was validated by real-time PCR. Cytokine levels in tissue and plasma were assayed by multiplex ELISA. Changes in lung ultrastructure were visualized by electron microscopy. We found that genes involved in primary inflammation, innate immune response, and apoptosis peaked at 2 hrs. Inflammatory and immune response genes that function in the stimulation of monocytes, natural killer and T-cells, and in the modulation of cell adhesion peaked at 8 hrs, while genes involved in wound healing and functional recovery were upregulated at 24 hrs.ConclusionThe analysis of gene expression modulation in response to sepsis provides the baseline information that is crucial for the understanding of the pathophysiology of systemic inflammation and may facilitate the development of future approaches for sepsis therapy.