Project description:Aim: Differentiation of cardiac fibroblasts (Fb) into myofibroblasts (MyoFb) is responsible for connective tissue buildup in myocardial remodeling. We examined reversibility of MyoFb differentiation. Methods and Results: Adult rat cardiac Fb were cultured on a plastic substratum providing mechanical stress, with conditions to obtain different Fb phenotypes. Fb spontaneously differentiated to proliferating MyoFb (p-MyoFb) with stress fiber formation decorated with alpha-smooth muscle actin (M-NM-1-SMA). Transforming growth factor-M-NM-21 (TGF-M-NM-21) promoted terminal differentiation into M-NM-1-SMA positive MyoFb showing near absence of proliferation i.e. non-p-MyoFb (2-fold increase in cell number after 12 days vs 11-fold for p-MyoFb). SD-208, a TGF-M-NM-2-receptor-I kinase blocker, inhibited p-MyoFb differentiation as shown by stress fiber absence, low levels of M-NM-1-SMA protein expression, and high levels of proliferation (32-fold increase after 12 days). Fb seeded in collagen matrices induced no contraction, whereas p-MyoFb and non-p-MyoFb induced 2.5- and 4-fold contraction. Fb produced low levels of collagen and secreted high levels of IL-10. Non-p-MyoFb showed high collagen production and high MCP-1 and TIMP-1 secretion. Transcriptome analysis indicated differential gene expression between all phenotypes. Dedifferentiation of p-MyoFb, but not of non-p-MyoFb, was induced by SD-208 despite maintained stress, shown by stress fiber de-polymerization in 30% of p-MyoFb vs in 8% of non-p-MyoFb. Stress fiber de-polymerization could be induced by mechanical strain release in p-MyoFb and non-p-MyoFb (2 day culture in unrestrained 3-D collagen matrices). Only p-MyoFb showed true dedifferentiation after long-term 3-D culture. Conclusions: Both reduction in mechanical strain and TGF-M-NM-2-receptor-I kinase inhibition can reverse p-MyoFb differentiation but not in non-p-MyoFb. Fibroblasts isolated from each rat heart (n= 4) were cultured in specific conditions to obtain different fibroblast phenotypes: 1) spontaneously differentiation into proliferating myofibroblasts (code RC), 2) terminal differentiation into non-proliferating myofibroblasts with TGF-M-NM-21 (code RT) and 3) inhibition of myofibroblast differentiation with SD-208, a TGF-M-NM-2-receptor-I kinase blocker (code RS). RNA concentration and purity from a total of 12 samples were determined spectrophotometrically using the Nanodrop ND-1000 (Nanodrop Technologies) and RNA integrity was assessed using a Bioanalyser 2100 (Agilent). Using the Ambion WT Expression Kit, per sample, an amount of 100 ng of total RNA spiked with bacterial poly-A RNA positive controls (Affymetrix) was converted to double stranded cDNA in a reverse transcription reaction. Next the sample was converted and amplified to antisense cRNA in an in vitro transcription reaction which was subsequently converted to single stranded sense cDNA. Finally, samples were fragmented and labeled with biotin in a terminal labeling reaction according to the Affymetrix WT Terminal Labeling Kit. A mixture of fragmented biotinylated cDNA and hybridisation controls (Affymetrix) was hybridised on Affymetrix GeneChipM-BM-. Rat Gene 2.0 ST array followed by staining and washing in a GeneChipM-BM-. fluidics station 450 (Affymetrix) according to the manufacturerM-bM-^@M-^Ys procedures. To assess the raw probe signal intensities, chips were scanned using a GeneChipM-BM-. scanner 3000 (Affymetrix).

Project description:microRNAs, important regulators of cell proliferation and apoptosis, have been shown to be involved in the pathogenesis of acute myeloid leukemia in adulthood AML. However, comprehensive studies in AML of children and adolescents are missing so far. We investigated the miRNA expression profiles of different AML subtypes from 102 pediatric patients in comparison to CD34+ cells from healthy donors and adult AML patients, in order to identify differentially expressed miRNAs. Pediatric samples with core factor binding acute myeloid leukemia and promyelocytic leukemia could be distinguished from each other and MLL rearranged AML subtypes by 9 and 18 miRNAs, respectively. miR-126, -146a, -181a/b, -100, and miR-125b were identified as highest differentially expressed with marked difference of expression between pediatric and adulthood samples of the same cytogenetic subgroup. We next isolated the miRNA targeting complex from t(8;21) and t(15;17) cell line models and comprehensively identified bound miRNAs and targeted mRNAs by a newly devised immunoprecipitation assay followed by rapid microarray detection. Our findings indicate separate binding preferences for the four human Argonaute proteins. Subsequent bioinformatic analysis revealed a concerted action of different Ago proteins in the regulation of AML-relevant pathways, providing an experimental based database of miRNA-mRNA target interaction in Argonaute proteins. Ago-associated microRNAs: Co-immunoprecipitation in the acute myeloid leukemia cell line models, KASUMI-1 and NB4, of the four human Argonaute complexes using monoclonal antibodies and stringent washing conditions. We performed photo-activated UV cross-linking using 4M-bM-^@M-^Y-thioruidine before cell lysis. Unspecific binding to the bead matrix and to the Fc part of the monoclonal rat antibody were recorded and corrected by empty bead controls and an antibody isotype control. Argonaute-associated miRNAs/mRNAs and unspecific bound miRNAs/mRNAs of the isotype control were identified by microarray hybridization. These experiments were performed in triplicates. Ago-associated mRNAs: Co-immunoprecipitation in the acute myeloid leukemia cell line models, KASUMI-1 and NB4, of the four human Argonaute complexes using monoclonal antibodies and stringent washing conditions. We performed photo-activated UV cross-linking using 4M-bM-^@M-^Y-thioruidine before cell lysis. Unspecific binding to the bead matrix and to the Fc part of the monoclonal rat antibody were recorded and corrected by empty bead controls and an antibody isotype control. Argonaute-associated miRNAs/mRNAs and unspecific bound miRNAs/mRNAs of the isotype control were identified by microarray hybridization. These experiments were performed in triplicates. AML-patient microRNAs: RNA extraction using the TRIzol protocol (Invitrogen), labeling of RNA with Cy3- (universal reference) and Cy5-Dyes (samples) using a truncated and mutated RNA ligase, hybridization of miRNAs over night at 42M-BM-0C using miRXplore microarrays and the a-Hyb Hybridization Station (MACS molecular Miltenyi Biotec)

Project description:BACKGROUND: Orofacial development is a multifaceted process involving precise, spatio-temporal expression of a panoply of genes. MicroRNAs (miRNAs) constitute the largest family of noncoding RNAs involved in gene silencing, and represent critical regulators of cell and tissue differentiation. MicroRNA gene expression profiling is an effective means of acquiring novel and valuable information regarding the expression and regulation of genes, under the control of miRNA, involved in mammalian orofacial development. RESULTS: To identify differentially expressed miRNAs during mammalian orofacial ontogenesis, miRNA expression profiles from gestation day (GD) -12, -13 and -14 murine orofacial tissue were compared utilizing miRXplore™ microarrays from Miltenyi Biotech GmbH. TaqManTM quantitative Real-Time PCR was utilized for validation of gene expression changes. Cluster analysis of the microarray data was conducted with the clValid R package and the UPGMA (hierarchical) clustering method. Functional relationships between selected miRNAs were investigated using Ingenuity Pathway Analysis. Expression of over 26% of the approximately 588 murine miRNA genes examined was detected in murine orofacial tissues from GD 12, 13 and 14. Among these expressed genes several clusters were seen to be developmentally regulated. Differential expression of genes encoding miRNAs within such clusters were shown to target genes encoding proteins involved in cell proliferation, cell adhesion, differentiation, apoptosis and epithelial-mesenchymal transformation, all processes critical for normal orofacial development. Functional relationships between miRNAs differentially expressed were investigated using Ingenuity Pathway Analysis (IPA; Ingenuity Systems). CONCLUSIONS: Using miRNA microarray technology, unique gene expression signatures of hundreds of miRNAs in embryonic orofacial tissue were defined. Gene targeting and functional analysis revealed that the expression of numerous protein-encoding genes, crucial to normal orofacial ontogeny, may be regulated by specific miRNAs. Time-course experiment (Developmental Stages), ICR mice embryos on gestational days (GD) 12, 13 and 14. Biological replicates: For each day of gestation, 3 independent pools of 15 to 20 staged embryos were used to procure embryonic orofacial tissues for preparation of 3 distinct pools of RNA that were independently processed and applied to individual miRXplore™ microRNA Microarray chips (Miltenyi Biotec GmbH). Technology: 2-color spotted cDNA, Hy5 (experimental sample) vs. Hy3 (control - miRXplore Universal Reference).

Project description:BACKGROUND: Development of the neural tube is a highly orchestrated process relying on precise, spatio-temporal expression of numerous genes as well as hierarchies of signal transduction and gene regulatory networks. Disruption of expression of a number of genes participating in these networks is believed to underlie developmental anomalies such as neural tube defects (NTDs) resulting from anomalous neural tube morphogenesis. MicroRNAs (miRNAs), a large family of noncoding RNAs, have been shown to function as gene silencers, and thus, are key modulators of cell and tissue differentiation. To elucidate potential roles of miRNAs in murine neural tube development, miRNA gene expression profiling has been utilized in the current study, to garner novel and in-depth knowledge on the expression and regulation of genes encoding miRNAs as well as their potential target genes governing maturation of the mammalian neural tube. METHODS: With the aim of identifying differentially expressed miRNAs during mammalian neural tube ontogenesis, miRNA expression profiles from gestation day (GD) -8.5, -9.0 and -9.5 murine neural tube tissue were compared utilizing miRXplore™ microarrays from Miltenyi Biotech GmbH. Gene expression changes observed in microarray analysis were verified by TaqManTM quantitative Real-Time PCR. clValid R package and the UPGMA (hierarchical) clustering method were utilized for cluster analysis of the microarray data. Functional associations among selected miRNAs were examined exploiting Ingenuity Pathway Analysis. RESULTS: Expression of approximately 12% of the 609 murine miRNA genes examined was detected in murine neural tube tissues from GD -8.5, -9.0 and -9.5. Clustering analysis revealed several developmentally regulated clusters among these expressed genes. MicroRNA target analysis enabled identification of a panoply of protein-coding target genes of the differentially expressed miRNAs within such clusters. Interestingly, many of these target genes have been shown to be associated with vital cellular processes such as cell proliferation, cell adhesion, cell migration, differentiation, apoptosis and epithelial-mesenchymal transformation, all of which are essential for normal neural tube development. Utilization of Ingenuity Pathway Analysis (IPA; Ingenuity Systems) allowed identification of interactive biological networks connecting differentially expressed miRNAs and their target genes highlighting functional relationships. CONCLUSIONS: In the present study, a unique gene expression signature of a range of miRNAs in embryonic neural tube tissue was delineated. Analysis of miRNA target genes and gene interaction pathways emphasized that expression of numerous protein-encoding genes, indispensable for normal neural tube morphogenesis, may be regulated by specific miRNAs. Time-course experiment (Developmental Stages), ICR mice embryos on gestational days (GD) 8.5, 9.0 and 9.5. Biological replicates: For each day of gestation, 3 independent pools of 15 to 20 staged embryos were used to procure embryonic orofacial tissues for preparation of 3 distinct pools of RNA that were independently processed and applied to individual miRXplore™ microRNA Microarray chips (Miltenyi Biotec GmbH). Technology: 2-color spotted cDNA, Hy5 (experimental sample) vs. Hy3 (control - miRXplore Universal Reference).

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Identification of miRNAs regulated by TGF-b in human CD8+ T cells

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