Project description:Macrophage activation must be tightly controlled to prevent overzealous responses that cause self-damage. MicroRNAs have been shown to promote classical macrophage activation by blocking concomitant anti-inflammatory signals and transcription factors, but can also place restraints on activation by preventing excessive TLR-signalling. In contrast, the microRNA profile associated with alternatively activated macrophages and their role in regulating wound-healing or anti-helminthic responses has not yet been described. Utilizing an in vivo model of alternative activation, in which adult Brugia malayi nematodes are surgically implanted in the peritoneal cavity of mice, we examined the profile of microRNA expression in these alternatively activated macrophages and compared this to alternatively activated IL-4 receptor knockout macrophages and thioglycollate elicited macrophages. Peritoneal macrophages from BALB/c wild type or IL-4 receptor knockout mice were elicited with thioglycollate or using nemtodes (peritoneal implant of Brugia malayi). The latter leads to a population of alternatively activated macrophages. Microarray analysis was used to examine the microRNA profile of WT alternatively activated macrophages (n = 4), IL-4 receptor knockout alternatively activated macrophages (n = 4), WT thioglycollate elicited macrophages (n = 3) and IL-4 receptor knockout thioglycollate elicited macrophages (n = 3).
Project description:Here we study the effect of LPS in the transcriptome of thioglycollate-elicited peritoneal macrophages isolated from Ldlr knock out mice
Project description:Here we study the effect of LPS in the transcriptome of thioglycollate-elicited peritoneal macrophages isolated from Ldlr knock out and Ch25h;Ldlr double knock out mice
Project description:Data from SREBP1c binding to the genome was visualized using Genome Browser (UCSC) in order to test its role in Mafb transcriptional regulation SREBP ChIP was performed in thioglycollate-elicited peritoneal macrophages treated as indicated.
Project description:Analysis of alternative activation of macrophages at gene expression level. The study forms part of a wider study where we compare the effects of IL-4 in different human and mouse macrophages. Our results support the notion that in vitro culture conditions greatly affect the macrophage response to IL-4. Total RNA obtained from Thioglycollate and Biogel elicited peritoneal macrophages exposed to 20 ng/ml of IL-4 for 18 hours. Biogel and thioglycollate elicited macrophages were stimulated with the Th2 cytokine IL-4, for RNA extraction and hybridization on Affymetrix microarrays.
Project description:Data from nuclear receptors RXR and PPARg binding to the genome was visualized using Genome Browser (UCSC) in order to test their role in Mafb transcriptional regulation RXR and PPARg ChIP was performed in thioglycollate-elicited peritoneal macrophages in basal conditions
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:TSA treatment blocks LPS-induction of several inflammatory target genes in primary macrophages. The microarray experiment was performed to identify LPS-inducible, LXR-sensitive target genes that retained LPS-induction in the presence of TSA. Thioglycollate-elicited macrophages were isolated from mice by peritoneal lavage 3 days following peritoneal injection of 2.5 ml 3% thioglycollate (DIFCO). Cells were plated in RPMI medium 1640 and 10% fetal bovine serum, washed after 5 h the medium was removed and cells were fed with fresh medium containing 0.5% fetal bovine serum. Cells were treated with TSA (Wako) at 100nM and/or with LPS (Sigma) at concentration of 100 ng/ml in the absence or presence of receptor-specific agonist for LXR (GW3965) at 1 µM. Keywords: TSA, LPS, LXR agonist