Project description:Akirin2 is an evolutionally conserved nuclear protein involved in the regulation of a set of inflammatory gene expression in various cell types. We used microarrays to examine the effect of Akirin2 deficiency in LPS-inducible gene expression in macrophages Peritoneal macrophages from wild-type and LysM-Cre+;Akirin2fl/fl mice were stimulated with LPS for 0, 2 and 4 hours, followed by RNA extraction and microarray analysis.
Project description:Macrophages were derived from the bone-marrow of 3 x fl/+ Dicer LysCre +/- (wild-type) and 3 x fl/fl Dicer LysCre +/- mice and stimulated with IL-4 (50ng/mL) for 72h. Total RNA was isolated and analyzed by gene array. In this experiment, we derived Dicer deficient bone-marrow macrophages using Dicer fl/+ LysM-Cre by Dicer fl/+ crossed mice to obtain Dicer fl/fl LysM-cre progeny (and Dicer deficient macrophages). Next, we studied the effects of IL-4 stimulation in macrophage with a deficiency in Dicer/microRNAs.
Project description:Comparative analysis of gene expression in bone marrow-derived macrophages (BMDM) from trsp knockout mice (Trspfl/fl-LysM-Cre+/-) and Control (Trspfl/fl-LysM-Cre-/-) mice. Selenium, a micronutrient whose deficiency in the diet causes immune dysfunction and inflammatory disorders, exerts its physiological effects partly in the form of selenium-containing proteins (selenoproteins). Incorporation of selenium into the amino acid selenocysteine (Sec), and subsequently into selenoproteins, is mediated by Sec tRNA[Ser]Sec. To identify macrophage-specific selenoprotein function, we generated mice with the Sec tRNA[Ser]Sec gene specifically deleted in myeloid cells. These mutant mice were devoid of the selenoproteome in macrophages, yet exhibited largely normal inflammatory responses. However, selenoprotein deficiency led to aberrant expression of extracellular matrix-related genes, and diminished migration of macrophages in a protein gel matrix. Therefore, selenium status may affect immune defense and tissue homeostasis through its effect on selenoprotein expression and the trafficking of tissue macrophages. We have generated mice in which we have selectively removed the selenocysteine tRNA gene (trsp) in macrophages under the control of LysM-Cre promoter. Microarray analysis was performed on RNA samples taken from bone marrow-derived macrophages in knockout and control mice. 1. Control unstimulated 2. Knockout unstimulated 3. Control lipopolysaccharide (LPS) stimulated (4h) 4. Knockout LPS stimulated (4h). Three replicates for each condition. Thus, a total of 12 samples.
Project description:The responses of macrophages to lipopolysaccharide (LPS) might determine the direction of clinical manifestations of sepsis, which is the immune response against severe infection. Meanwhile, the enhancer of zeste homologue 2 (Ezh2), a histone lysine methyltransferase of epigenetic regulation, might interfere with LPS response. With a single LPS stimulation, Ezh2 null(Ezh2flox/flox; LysM-Crecre/−) macrophages demonstrated lower supernatant TNF-α than Ezh2 control (Ezh2fl/fl; LysM-Cre−/−), perhaps due to an upregulation of Socs3, which is a suppressor of cytokine signaling 3, due to the loss of the Ezh2 gene. In LPS tolerance, Ezh2 null macrophages indicated higher supernatant TNF-α and IL-6 than the control, supporting an impact of the loss of the Ezh2 inhibitory gene. In parallel, Ezh2 null mice demonstrated lower serum TNF-α and IL-6 than the control mice after an LPS injection, indicating a less severe LPS-induced hyper-inflammation in Ezh2 null mice. In conclusion, an absence of Ezh2 in macrophages resulted in less severe LPS-induced inflammation, as indicated by low serum cytokines, with less severe LPS tolerance, as demonstrated by higher cytokine production, partly through the upregulated Socs3.
Project description:We show that meteorin (Metrn) from hypoxic macrophages restrains hematopoietic stem cells (HSCs) proliferation and mobilization. In macrophages specific Metrn knockout mice, reactive oxygen species levels in HSCs were upregulated through activating phospholipase C signaling. Macrophage specific knockout mice for Metrn (Metrn-fl/fl*LysM-Cre) were generated. Transcriptome profiling (RNA-Seq) and differential gene expression analysis of bone marrow LSK (lin- sca-1+ c-kit+) cells from Metrn-fl/fl*LysM-Cre (Metrn-cKO) and Metrn-fl/fl mice was performed. Metrn cKO mice showed a regulatory role for HSPCs by macrophages.
Project description:To assess the role of a transcription factor St18 in LPS response, peritoneal macrophage from wild-type or LysM-St18flox mice were stimulated with LPS and gene expressions were compared.
Project description:The impaired aerobic glycolysis of monocyte/macrophage are the main features in sepsis that encountered immunosuppression. NLRC3, an inhibitory sensor, can diminish the Toll-like receptor 4 pathways of macrophages which is associated with sepsis-induced immunosuppression, but whether NLRC3 plays key role in regulating the immunosuppression of macrophage via interfering glycolysis still unclear. The aim of this study was to characterize the transcriptome alterations by which NLRC3 loss, and further investigate the role of the glycolysis in the macrophage with the development of sepsis. Bone marrow-derived macrophages (BMDMs) was isolated from the femurs and tibias of the NLRC3 WT (LysM-Cre-NLRC3fl/fl) and NLRC3ΔMac (LysM-Cre+ NLRC3fl/fl) mice and then was treated with or without LPS for 12 hours, and the macrophages mRNA profiles of five-weeks-old NLRC3 WT mice (WT macrophages) and of five-weeks-old NLRC3ΔMac mice (NLRC3-/- macrophages) were generated by deep sequencing, in triplicate, using Illumina 6000.
Project description:Immune-Responsive Gene 1 (Irg1) is a mitochondrial enzyme that produces itaconate under inflammatory conditions principally in cells of myeloid lineage. Cell culture studies suggest that itaconate regulates inflammation through inhibitory effects on cytokine and reactive oxygen species production. To evaluate the functions of Irg1 in vivo, we challenged wild-type (WT) and Irg1-/- mice with Mycobacterium tuberculosis (Mtb) and monitored disease progression. Irg1-/- but not WT mice succumbed rapidly to Mtb, and mortality was associated with increased infection, inflammation, and pathology. Infection of LysM-Cre Irg1fl/fl, MPR8-Cre Irg1fl/fl, and CD11c-Cre Irg1fl/fl conditional knockout mice along with neutrophil depletion experiments revealed a role for Irg1 in alveolar macrophages and LysM+ myeloid cells in preventing neutrophil-mediated immunopathology and disease. RNA-seq analyses suggest that Irg1 and its production of itaconate temper Mtb-induced inflammatory responses in myeloid cells at the transcriptional level. Thus, Irg1 modulates inflammation to curtail Mtb-induced lung disease.
Project description:Iron is an essential nutrient for humans as well as for pathogens. Hence, its correct distribution at the systemic and cellular level is mandatory for mounting an effective innate immune defense. Here we delved into the role of macrophage-expressed iron storing protein ferritin H (FTH) in immune response against the model intracellular pathogen Salmonella Typhimurium. Mice lacking FTH in the myeloid lineage (LysM-Cre+/+ Fthfl/fl) displayed impaired iron storage capacities in tissue leukocyte compartment, increased levels of labile iron in macrophages and an accelerated macrophage-mediated iron turnover. Without iron supplementation, wildtype (WT) and LysM-Cre+/+ Fthfl/fl animals showed comparable susceptibility to Salmonella infection. Interestingly, iron supplementation rapidly elicited symptoms of cytokine storm and drastically shortened survival of LysM-Cre+/+ Fthfl/fl mice. Mechanistically, we traced this phenotype back to labile iron-mediated hyperactivity of the inflammasome in FTH-deficient macrophages, culminating in excessive IL-1β secretion and secondary triggering of NF-kappaB-dependent inflammatory circuits. Accordingly, bacterial burden and cytokine levels in iron-loaded LysM-Cre+/+ Fthfl/fl mice could be effectively kept at bay by pharmacological inflammasome and IL-1β blockade. These findings point towards a previously unrecognized role of ferritin as an inhibitor of iron-dependent inflammasome activity in macrophages and a checkpoint of systemic innate response.
Project description:mRNA from wild-type (Cre-) and MLL1-deficient (Cre+) BMDMs were analyzed via gene chip (Mouse Gene ST 2.1, Affymetrix) for relative expression changes. Isolated mRNA from Cre- and Cre+ BMDMs stimulated with classical activation signals (IFNg, LPS or IFNg+LPS) was analyzed using a gene chip panel of >40,000 RefSeq transcripts, and resulting fold expression was determined by analyzing quality-controlled expression values for validated probesets. Bone marrow derived macrophages from wild-type (Cre-) or MLL1-deficient (Cre+) mice were stimulated in vitro with IFNgamma (10 ng/ml), LPS (100 ng/ml) or the combination of IFNgamma+LPS for six hours. Cells were then processed in Trizol reagent for RNA extraction.