Project description:We used microarrays to look at overall gene expression differences between miR-155-/- and WT dendritic cells under inflammatory conditions. Bone marrow from either wild type or miR-155-/- C57Bl/6 mice was differentiated into dendritic cells by incubating with GM-CSF. These cells were then stimulated with LPS, and gene expression was performed.
Project description:MicroRNAs regulated by lipopolysaccharide (LPS) target genes that contribute to the inflammatory phenotype. Here we showed that the protein kinase Akt1, which is activated by LPS, positively regulated miRNAs let-7e, miR-181c but negatively regulated miR-155 and miR-125b. In silico analyses and transfection studies revealed that let-7e repressed Toll-like receptor 4 (TLR4) whereas miR-155 repressed SOCS1, two proteins critical for LPS-driven TLR signalling, which regulate endotoxin sensitivity and tolerance. As a result, Akt1-/- macrophages exhibited increased responsiveness to LPS in culture and Akt1-/- mice did not develop endotoxin tolerance in vivo. Overexpression of let-7e and suppression of miR-155 in Akt1-/- macrophages restored sensitivity and tolerance to LPS in culture and in animals. These results indicate that Akt1 regulates the response of macrophages to LPS by controlling miRNA expression. The data deposited here contain the entire analysis of miRNA profile of Akt1+/+ and Akt1-/- thioglycollate elicited peritoneal macrophages following stimulation with LPS for 3 hours in culture. Thioglycollate elicited macrophages were cultured in complete DMEM medium, stimulated with LPS for 3 hours and RNA was extracted. Samples were analyzed using Taq-man PCR miRNA arrays (Dana Farber microarray Facility).
Project description:Gene expression from WT and NFAT5 KO primary macrophage cultures. Keywords: Bone-marrow derived macrophages. We analyzed 4 arrays from each condition: unstimulated WT BMDMs, LPS stimulated WT BMDMs, unstimulated KO BMDMs, LPS stimulated KO BMDMs.
Project description:MicroRNAs (miRNAs) are small RNAs that play important regulatory roles in many cellular pathways. MiRNAs associate with members of the Argonaute (Ago) protein family and bind to partially complementary sequences on mRNAs and induce translational repression or mRNA decay. MiRNA expression can be controlled by transcription factors and can therefore be cell type- or tissue-specific. Here we have analyzed miRNA expression profiles in murine monocyte-derived dendritic cells (DCs) and macrophages upon stimulation with LPS, LDL, eLDL and oxLDL to identify not only stimuli-specific miRNA, but also to identify a hierarchical miRNA system involving miR-155. For this, miR-155 knockout dendritic cells and macrophages were also sequenced using the same stimuli. Sequencing of murine monocyte-derived dendritic cells and macrophages (each wild type and miR-155 knock out cells) matured and stimulated, respectively, by LPS, oxLDL, eLDL or LDL.
Project description:To confirm the changed gene expression profiles in GPR15 knock out (KO) macrophages, we applied a SurePrint G3 Mouse Gene Expression service from Takara Bio Inc (Kusatsu, Shiga, Japan) to analyze gene expression profiles in lipopolysaccharide (LPS)-stimulated GPR15KO macrophages, comparing with wild type (WT) macrophages. Most significantly up-regulated genes in GPR15KO macropahges included Il6, Il17a, Il23, Tnfsf8, Il1b, Ifna2 and Ccnd2. On the contrary, several inflammation-related genes, including Ccl17, Itgax, Nrp1 and Rasgrf2, were down-regulated in WT macrophages, compared to GPR15 KO macrophages. Abdominal macrophages from WT and GPR15 KO mice were stimulated with PBS or LPS (100 ng/ml) for 4 hrs. Total RNA were extracted using a TRIzol-chloroform based method.
Project description:Using microarrays, we compared the changes in levels of gene expression between wildtype and Bcl6 KO macrophages in the absence or presence of LPS. Total RNA was obtained from WT and Bcl6 KO unstimulated and LPS-stimulated primary bone marrow-derived macrophages
Project description:MicroRNAs regulated by lipopolysaccharide (LPS) target genes that contribute to the inflammatory phenotype. Here we showed that the protein kinase Akt1, which is activated by LPS, positively regulated miRNAs let-7e, miR-181c but negatively regulated miR-155 and miR-125b. In silico analyses and transfection studies revealed that let-7e repressed Toll-like receptor 4 (TLR4) whereas miR-155 repressed SOCS1, two proteins critical for LPS-driven TLR signalling, which regulate endotoxin sensitivity and tolerance. As a result, Akt1-/- macrophages exhibited increased responsiveness to LPS in culture and Akt1-/- mice did not develop endotoxin tolerance in vivo. Overexpression of let-7e and suppression of miR-155 in Akt1-/- macrophages restored sensitivity and tolerance to LPS in culture and in animals. These results indicate that Akt1 regulates the response of macrophages to LPS by controlling miRNA expression. The data deposited here contain the entire analysis of miRNA profile of Akt1+/+ and Akt1-/- thioglycollate elicited peritoneal macrophages following stimulation with LPS for 3 hours in culture.