Dual oxidases play a role in innate host defense at barrier epithelia. We examined the effect of loss of dual oxidase function (duoxa-/-) on gene expression in the mouse terminal ileum at homeostasis. To control for cage/litter effects, duoxa-/- were cohoused with wild type littermate controls.
Increased Expression of DUOX2 Is an Epithelial Response to Mucosal Dysbiosis Required for Immune Homeostasis in Mouse Intestine.
Sex, Age, Specimen part
View SamplesGut dysbiosis is closely involved in the pathogenesis of inflammatory bowel disease (IBD). However, it remains unclear whether IBD-associated gut dysbiosis plays a primary role in disease manifestation or is merely secondary to intestinal inflammation. Here, we established a humanized gnotobiotic (hGB) mouse system to assess the functional role of gut dysbiosis associated with two types of IBD - Crohn's disease (CD) and ulcerative colitis (UC).
Functional Characterization of Inflammatory Bowel Disease-Associated Gut Dysbiosis in Gnotobiotic Mice.
Specimen part
View SamplesDespite accepted health benefits of dietary fiber, little is known about the mechanisms by which fiber deprivation impacts the gut microbiota and alters disease risk. Using a gnotobiotic model, in which mice were colonized with a synthetic human gut microbiota, we elucidated the functional interactions between dietary fiber, the gut microbiota and the colonic mucus barrier, which serves as a primary defence against pathogens. We show that during chronic or intermittent dietary fiber deficiency, the gut microbiota resorts to host-secreted mucus glycoproteins as a nutrient source, leading to erosion of the colonic mucus barrier. Dietary fiber deprivation promoted greater epithelial access and lethal colitis by the mucosal pathogen, Citrobacter rodentium, but only in the presence of a fiber-deprived microbiota that is pushed to degrade the mucus layer. Our work reveals intricate pathways linking diet, gut microbiome and intestinal barrier dysfunction, which could be exploited to improve health using dietary therapeutics.
A Dietary Fiber-Deprived Gut Microbiota Degrades the Colonic Mucus Barrier and Enhances Pathogen Susceptibility.
Specimen part
View SamplesNIH3T3 in the middle of G0 to G1 transion consists of the cells which is still staying G0 phase and the cells which enters G1. Monitoring the expressions of p27 and Cdt1 enables to distinguish these two; p27+/Cdt1+ cells as the cells in G0 phase and p27-Cdt1+ cells as G1 phase
A novel cell-cycle-indicator, mVenus-p27K-, identifies quiescent cells and visualizes G0-G1 transition.
Cell line
View SamplesAlthough LIPUS has been shown to enhance fracture healing, the underlying mechanism of LIPUS remains to be fully elucidated. Here, to understand the molecular mechanism underlying cellular responses to LIPUS, we investigated gene expression profiles in mouse MC3T3-E1 preosteoblast cells using a GeneChip system.
Genes responsive to low-intensity pulsed ultrasound in MC3T3-E1 preosteoblast cells.
Specimen part, Cell line, Treatment, Time
View SamplesGerminal centers (GCs) are clusters of activated B cells built on stromal cells known as follicular dendritic cells (FDCs). In the Peyers patches (PPs), GCs are chronically induced by bacteria and are the major sites for generation of gut IgA immune responses. Whether FDCs directly contribute to the IgA production in PP GCs is unknown.
The sensing of environmental stimuli by follicular dendritic cells promotes immunoglobulin A generation in the gut.
Specimen part
View SamplesSkeletal muscle mass is an important determinant of whole-body glucose disposal. We here show that mice (M-PDK1KO mice) with skeletal muscle–specific deficiency of 3'-phosphoinositide–dependent kinase 1 (PDK1), a key component of the phosphatidylinositol 3-kinase (PI3K) signaling pathway, manifest a reduced skeletal muscle mass under the static condition as well as impairment of exercise load–induced muscle hypertrophy.
Role of PDK1 in skeletal muscle hypertrophy induced by mechanical load.
Sex, Specimen part
View SamplesHigh levels of Hes1 expression are frequently found in BCR-ABL-positive chronic myelogenous leukemia in blast crisis (CML-BC). In mouse bone marrow transplantation (BMT) models, co-expression of BCR-ABL and Hes1 induces CML-BClike disease; however the underlying mechanism remained elusive. Here, based on gene expression analysis, we show that MMP-9 is upregulated by Hes1 in common myeloid progenitors (CMPs). Analysis of promoter activity demonstrated that Hes1 upregulated MMP-9 by activating NF-kB. Analysis of 20 samples from CML-BC patients showed that MMP-9 was highly expressed in three, with two exhibiting high levels of Hes1 expression. Interestingly, MMP-9 deficiency impaired the cobblestone area-forming ability of CMPs expressing BCR-ABL and Hes1 that were in conjunction with a stromal cell layer. In addition, these CMPs secreted MMP-9, promoting the release of soluble Kit-ligand (sKitL) from stromal cells, thereby enhancing proliferation of the leukemic cells. In accordance, mice transplanted with CMPs expressing BCR-ABL and Hes1 exhibited high levels of sKitL as well as MMP-9 in the serum. Importantly, MMP-9 deficiency impaired the development of CML-BClike disease induced by BCR-ABL and Hes1 in mouse BMT models. The present results suggest that Hes1 promotes the development of CML-BC, partly through MMP-9 upregulation in leukemic cells.
Hes1 promotes blast crisis in chronic myelogenous leukemia through MMP-9 upregulation in leukemic cells.
Specimen part
View SamplesRecurrent mutations in ASXL1 are found in various hematological malignancies and are associated with poor prognosis. In particular, ASXL1 mutations are frequently found in patients with hematological malignancies associated with myelodysplasia including myelodysplastic syndromes (MDS), and chronic myelomonocytic leukemia. Although loss-of-function ASXL1 mutations promote myeloid transformation, a large subset of ASXL1 mutations is thought to result in stable truncation of ASXL1. Here we demonstrate that C-terminal truncating ASXL1 mutations (ASXL1-MT) inhibit myeloid differentiation and induce MDS-like disease in mice, displaying all the features of human MDS including multi-lineage myelodysplasia, pancytopenia and occasional progression to overt leukemia. Concerning the molecular mechanisms, ASXL1-MT derepressed expression of Hoxa9 and miR-125a through inhibiting PRC2-mediated methylation of H3K27. miR-125a targeted expression of a surface receptor Clec5a, which was found to supports for myeloid differentiation. In addition, HOXA9 expression was high in MDS patients with ASXL1 mutations while Clec5a expression was generally low in MDS patients. Thus, ASXL1-MT induced MDS-like disease in mice via derepression of Hoxa9 and miR-125a, and Clec5a downregulation. Our data provide evidence for a novel axis of MDS pathogenesis (ASXL1 mutations-upregulation of HoxA9 and miR-125a-downregulation of Clec5a) and implicate both ASXL1 mutants and miR-125a as therapeutic targets in MDS.
Myelodysplastic syndromes are induced by histone methylation–altering ASXL1 mutations.
Cell line, Treatment
View SamplesRecurrent mutations in ASXL1 are found in various hematological malignancies and are associated with poor prognosis. In particular, ASXL1 mutations are frequently found in patients with hematological malignancies associated with myelodysplasia including myelodysplastic syndromes (MDS), and chronic myelomonocytic leukemia. Although loss-of-function ASXL1 mutations promote myeloid transformation, a large subset of ASXL1 mutations is thought to result in stable truncation of ASXL1. Here we demonstrate that C-terminal truncating ASXL1 mutations (ASXL1-MT) inhibit myeloid differentiation and induce MDS-like disease in mice, displaying all the features of human MDS including multi-lineage myelodysplasia, pancytopenia and occasional progression to overt leukemia. Concerning the molecular mechanisms, ASXL1-MT derepressed expression of Hoxa9 and miR-125a through inhibiting PRC2-mediated methylation of H3K27. miR-125a targeted expression of a surface receptor Clec5a, which was found to supports for myeloid differentiation. In addition, HOXA9 expression was high in MDS patients with ASXL1 mutations while Clec5a expression was generally low in MDS patients. Thus, ASXL1-MT induced MDS-like disease in mice via derepression of Hoxa9 and miR-125a, and Clec5a downregulation. Our data provide evidence for a novel axis of MDS pathogenesis (ASXL1 mutations-upregulation of HoxA9 and miR-125a-downregulation of Clec5a) and implicate both ASXL1 mutants and miR-125a as therapeutic targets in MDS.
Myelodysplastic syndromes are induced by histone methylation–altering ASXL1 mutations.
Specimen part
View Samples