Project description:To explore the effects of gut microbiota of young (8 weeks) or old mice (18~20 months) on stroke, feces of young (Y1-Y9) and old mice (O6-O16) were collected and analyzed by 16s rRNA sequencing. Then stroke model was established on young mouse receive feces from old mouse (DOT1-15) and young mouse receive feces from young mouse (DYT1-15). 16s rRNA sequencing were also performed for those young mice received feces from young and old mice.
Project description:Microbiota alteration and IFN-γ-producing CD4+ T cell overactivation are implicated in Crohn's disease (CD) pathogenesis. However, it remains unclear how dysbiosis enhances Th1 responses, leading to intestinal inflammation. Here, we identified key metabolites that are derived from dysbiotic microbiota and induce enhanced Th1 responses and severe colitis in mouse models. Patients with CD showed elevated lysophosphatidylserine (LysoPS) concentration in their feces, accompanied with a higher relative abundance of microbiota possessing a gene encoding the phospholipid-hydrolyzing enzyme phospholipase A. LysoPS induced metabolic reprograming, thereby eliciting aberrant effector responses in both human and mouse IFN-?-producing CD4+ T cells. Administration of LysoPS into T cell-dependent mouse colitis models induced severe inflammation. LysoPS-induced aggravation of colitis was impaired in mice lacking P2ry10 and P2ry10b, and their CD4+ T cells were hypo-responsive to LysoPS. Thus, our findings elaborate on the mechanism by which metabolites elevated in patients with CD harboring dysbiotic microbiota induce intestinal pathology.
Project description:The human intestinal microbiota plays an essential role in host health. Modifications in its composition and diversity could induce pathologies such as inflammatory bowel diseases (IBD). These diseases are characterized by an unbalanced intestinal microbiota (a process known as dysbiosis) and an altered immune response. Faecalibacterium prausnitzii, the most abundant commensal bacterium in the human intestinal microbiota of healthy individuals (representing more than 5% of the total bacterial population), has been reported to be lower in feces and mucosa-associated microbiota of IBD patients. In addition, we have shown that both F. prausnitzii and its culture supernatant (SN) have anti-inflammatory and protective effects in both acute and chronic colitis models. However, the host molecular mechanisms involved in these anti-inflammatory effects remain unknown. In order to address this issue, we performed DNA chip-based transcriptomic analyses in HT-29 human intestinal epithelial cells stimulated with TNF-a and exposed to F. prausnitzii SN or to BHI (growth medium for F prausnitzii).
Project description:Essential to terrestrial life is the formation of a competent skin barrier that prevents desiccation and entry by harmful substances. A tightly orchestrated series of cellular changes is required for the proper formation of the epidermal permeability barrier. These changes occur in the context of the commensal skin microbiota. Using germ free mice and antibiotic depletion models, we demonstrate the microbiota is necessary for proper differentiation and repair of the barrier. These effects were mediated by keratinocyte signaling through the aryl hydrocarbon receptor (AHR), a xenobiotic receptor that also regulates epidermal differentiation. Murine skin lacking keratinocyte AHR was more susceptible to infection by S. aureus and increased pathology in a model of atopic dermatitis. Topical colonization with a defined consortium of human skin commensals restored barrier competence in germ free skin and during epicutaneous sensitization; these effects were dependent on keratinocyte AHR. We reveal a fundamental role for the commensal skin microbiota in directing skin barrier formation and repair through the AHR, with far-reaching implications for the numerous skin disorders characterized by disrupted epidermal differentiation and/or barrier competence.
Project description:To examine potential changes of the intestinal microbiota in mice caused by repeated mild stress, we profiled bacteria and fungi in the mouse feces by sequencing the 16s v3v4 region and the ITS1-2 region.
Project description:Lung cancer is closely associated with chronic inflammation, but the mechanism underlying such inflammation has not been clearly defined. The lung is a mucosal tissue colonized by a diverse bacterial community at the steady state, and pulmonary infections commonly present in lung cancer patients are linked to clinical outcomes. Here we provide evidence that local microbiota provoke inflammation associated with lung adenocarcinoma by activating lung-resident gamma-delta T cells. Germ-free or antibiotic-treated mice were significantly protected from lung tumor initiation and progression induced by Kras mutation and p53 loss. Mechanistically, commensal bacteria stimulated My88-dependent IL-1beta and IL-23 production from myeloid cells, inducing proliferation and activation of Vγ6+Vδ1+ γδ T cells that produced IL-17 and other effector molecules to promote inflammation and tumor cell proliferation. Our findings provide a clear link between local microbiota-immune crosstalk and lung tumorigenesis, and thereby define key cellular and molecular mediators that may serve as effective targets in lung cancer treatment and prevention.
Project description:To compare the similarities and differences in species diversity of the gut microbiota between the patients with melasma and healthy subjects. The feces were collected for 16S rRNA sequencing analysis of the gut microbiota.
Project description:Tax1-binding protein 1 (Tax1bp1) negatively regulates NF-κB by editing the ubiquitylation of target molecules with its catalytic partner A20. Genetically engineered TAX1BP1-deficient (KO) mouse develops age-dependent inflammatory constitution in multiple organs including heart, liver, skin and succumb to premature heart failure. Laser capture dissection and gene expression microarray analysis on the mitral valves of TAX1BP1-KO mice (8 and 16 week old) revealed that the 588 transcription alterations. SAA3 (serum amyloid A3), at 1,180-fold induction (FI), CHI3L1(361-FI), HP(187-FI), IL1B(122-FI) and SPP1/OPN(101-FI) and WIF1 (Wnt inhibitory factor 1) at 11-fold decrease implied extensive inflammation and tissue degeneration at this microenvironment. Intense Saa3 staining and significant reduction of I-κBα at the same area, massive infiltration of inflammatory lymphocytes and edema formation at the peripheral areas of sinoatrial and atrioventricular node were also observed and electrocardiogram indicated atrioventricular conduction defect (elongated PQ-interval) in TAX1BP1-KO mice. Since antibiotics-induced ‘germ free’ status for three months significantly ameliorated these chronic autoimmune and altered cardiac excitation properties, we conclude that these chronic pathological conditions, as we named ‘pseudo-infective endocarditis’ were boosted by the commensal microbiota those who are usually harmless by their nature. This experimental outcome raises a novel mechanistic linkage between endothelial inflammation and cardiac dysfunction. We employed laser capture microdissection (LCM) and gene expression microarray technique to obtain the specific gene expression information of pathologic organ. Total RNAs of mitral valves from three independent tissues of 8- or 16-week age (-wk) male mice of either WT or TAX1BP1-KO mice were prepared by LCM followed by total RNA extraction kit. Then the global mRNA expression profiles were analyzed by Agilent gene expression microarray.
Project description:The potential for commensal microorganisms indigenous to a host (the microbiome or microbiota) to alter infection outcome by influencing host-pathogen interplay is largely unknown. We used a multi-omics systems approach, incorporating proteomics, metabolomics, glycomics, and metagenomics, to explore the molecular interplay between the murine host, the pathogen Salmonella enterica serovar Typhimurium (S. Typhimurium), and commensal gut microorganisms during intestinal infection with S. Typhimurium. We find proteomic evidence that S. Typhimurium thrives within the infected 129/SvJ mouse gut without antibiotic pre-treatment, inducing inflammation and disrupting the intestinal microbiome (e.g., suppressing Bacteroidetes and Firmicutes while promoting growth of Salmonella and Enterococcus). Alteration of the host microbiome population structure was highly correlated with gut environmental changes, including the accumulation of metabolites normally consumed by commensal microbiota. Finally, the less characterized phase of S. Typhimurium's lifecycle was investigated, and both proteomic and glycomic evidence suggests S. Typhimurium may take advantage of increased fucose moieties to metabolize fucose while growing in the gut. The application of multiple omics measurements to Salmonella-induced intestinal inflammation provides insights into complex molecular strategies employed during pathogenesis between host, pathogen, and the microbiome.
Project description:This study aimed to analyze changes in gut microbiota composition in mice after transplantation of fecal microbiota (FMT, N = 6) from the feces of NSCLC patients by analyzing fecal content using 16S rRNA sequencing, 10 days after transplantation. Specific-pathogen-free (SPF) mice were used for each experiments (N=4) as controls.