Project description:Hematopoietic stem/progenitor cells (HS/PCs) were transduced with lentiviral vectors overexpressing OFP and either miR-511-3p or a control, mutated miRNA sequence (miR-511-3p-mut). The transduced HS/PCs were then transplanted in recipient C57BL/6 mice. Tumors (Lewis lung carcinomas, LLC) were injected s.c. 4 weeks after HS/PC transplant. Lentiviral vector-transduced (OFP+), tumor-associated macrophages (TAMs) were isolated 4 weeks after LLC injection by fluorescence-activated cell sorting. Gene expression profiles of TAMs overexpressing either miR-511-3p or miR-511-3p-mut were obtained from 3 independent biological samples/each. Gene expression profiles of miRNA-overexpressing TAMs were then compared with the gene expression profiles of wild-type TAMs isolated from LLCs grown in nontransplanted C57BL/6 mice; the latter TAMs were subfractioned into MRC1+CD11c(low) or CD11c+MRC1(low) subsets before RNA isolation and analysis. Comparison of gene expression profiles of TAMs revealed that miR-511-3p overexpression tunes down the expression of multiple genes that are classically upregulated in protumoral MRC1+CD11c(low) TAMs. TAMs were isolated from Lewis lung carcinomas grown s.c. in C57BL/6 mice.
Project description:Hematopoietic stem/progenitor cells (HS/PCs) were transduced with lentiviral vectors overexpressing OFP and either miR-511-3p or a control, mutated miRNA sequence (miR-511-3p-mut). The transduced HS/PCs were then transplanted in recipient C57BL/6 mice. Tumors (Lewis lung carcinomas, LLC) were injected s.c. 4 weeks after HS/PC transplant. Lentiviral vector-transduced (OFP+), tumor-associated macrophages (TAMs) were isolated 4 weeks after LLC injection by fluorescence-activated cell sorting. Gene expression profiles of TAMs overexpressing either miR-511-3p or miR-511-3p-mut were obtained from 3 independent biological samples/each. Gene expression profiles of miRNA-overexpressing TAMs were then compared with the gene expression profiles of wild-type TAMs isolated from LLCs grown in nontransplanted C57BL/6 mice; the latter TAMs were subfractioned into MRC1+CD11c(low) or CD11c+MRC1(low) subsets before RNA isolation and analysis. Comparison of gene expression profiles of TAMs revealed that miR-511-3p overexpression tunes down the expression of multiple genes that are classically upregulated in protumoral MRC1+CD11c(low) TAMs.
Project description:BACKGROUND:Mannose receptor (MRC1/CD206) has been suggested to mediate allergic sensitization and asthma to multiple glycoallergens, including cockroach allergens. OBJECTIVE:We sought to determine the existence of a protective mechanism through which MRC1 limits allergic inflammation through its intronic miR-511-3p. METHODS:We examined MRC1-mediated cockroach allergen uptake by lung macrophages and lung inflammation using C57BL/6 wild-type (WT) and Mrc1-/- mice. The role of miR-511-3p in macrophage polarization and cockroach allergen-induced lung inflammation in mice transfected with adeno-associated virus (AAV)-miR-511-3p (AAV-cytomegalovirus-miR-511-3p-enhanced green fluorescent protein) was analyzed. Gene profiling of macrophages with or without miR-511-3p overexpression was also performed. RESULTS:Mrc1-/- lung macrophages showed a significant reduction in cockroach allergen uptake compared with WT mice, and Mrc1-/- mice had an exacerbated lung inflammation with increased levels of cockroach allergen-specific IgE and TH2/TH17 cytokines in a cockroach allergen-induced mouse model compared with WT mice. Macrophages from Mrc1-/- mice showed significantly reduced levels of miR-511-3 and an M1 phenotype, whereas overexpression of miR-511-3p rendered macrophages to exhibit a M2 phenotype. Furthermore, mice transfected with AAV-miR-511-3p showed a significant reduction in cockroach allergen-induced inflammation. Profiling of macrophages with or without miR-511-3p overexpression identified 729 differentially expressed genes, wherein expression of prostaglandin D2 synthase (Ptgds) and its product PGD2 were significantly downregulated by miR-511-3p. Ptgds showed a robust binding to miR-511-3p, which might contribute to the protective effect of miR-511-3p. Plasma levels of miR-511-3p were significantly lower in human asthmatic patients compared with nonasthmatic subjects. CONCLUSION:These studies support a critical but previously unrecognized role of MRC1 and miR-511-3p in protection against allergen-induced lung inflammation.
Project description:In response to microenvironmental signals macrophages undergo different activation, indicated as classic/M1 and alternative/M2 polarization. C-Myc transcription factor could be an essential player in M2 polarization. Functional relevance of c-Myc in M2 macrophage biology is investigated by evaluating the effect of 100-58F4, on the transcriptional profile induced on human macrophages by IL-4. Human monocytes were obtained from normal donor buffy coats by two-step gradient centrifugation using Ficoll (Biochrom) and Percoll (Amersham). Non-adherent cells were discarded, and the purified monocytes were incubated for 7 days in RPMI 1640 (Biochom) supplemented with 10% FCS (HyClone) and 100 ng/mL M-CSF to obtain resting macrophages. Macrophage polarization was obtained by removing the culture medium and culturing cells in RPMI 1640 supplemented with 10% FCS and 100 ng/mL LPS plus 20 ng/mL IFN-gamma (M1 polarization) or 20 ng/mL IL-4 (M2 polarization) for 24 h. When needed, chemical inhibitors were added with IL-4.
Project description:The model describes the mechanisms by which macrophages differentiate into a given phenotype. The model shows that both extracellular and intracellular signalling are both important for that process. More specifically, STAT1 activity favors macrophages polarization towards M1 phenotype and STAT6 activity favors macrophage polarization towards M2 phenotype. However, these polarizations are can be reversed by molecular signalling.
Project description:To experimentally investigate the function of hsa-miR-511-5p in AML monoblasts, we employed miRNA mimic mediated up-regulation of miR-511 in THP1 cells and subsequently analyzed a comprehensive gene expression profile. 4 samples of two independent miRNA mimic experiments were analyzed. THP1 monoblasts were transfected with 30 nM of Ambion Pre-miR miRNA Precursors (hsa-miR-511-5p AM10237 or negative Control #1 AM17110, Life Technologies).
Project description:To experimentally investigate the function of hsa-miR-511-5p in AML monoblasts, we employed miRNA mimic mediated up-regulation of miR-511 in THP1 cells and subsequently analyzed a comprehensive gene expression profile.