Project description:Background: Exosomes are nanovesicles of endocytic origin believed to be involved in communication between cells. Recently, it has been shown that mast cell exosomes contain RNA named "exosomal shuttle RNA". The aim of this study was to evaluate whether exosomal shuttle RNA could play a role in the communication between human mast cells and between human mast cells and human CD34 positive progenitor cells. Results: Exosomes from the human mast cell line HMC-1 contain RNA. The exosomes contain no or very little ribosomal RNA compared to their donor cells. The mRNA and microRNA content in exosomes and their donor cells was examined using microarray analyses. We found 116 microRNA in the exosomes and 134 microRNA in the cells, from which some were expressed at different level. DNA microarray experiments revealed the presence of approximately 1800 mRNAs in the exosomes, which represent 15% of the donor cell mRNA content. Transfer experiments revealed that exosomes and their RNA can transfer to other HMC-1 cells and to CD34 positive progenitors. Conclusions: To conclude, HMC-1 exosomes contain mRNA and microRNA that can be transferred to other mast cells and to CD34 progenitors. This shuttle of exosomal RNA may represent a powerful mode of communication between cells where cells send genetic information to other cells over a distance via exosomes. [miRNA profiling] Identification of microRNA was performed by Exiqon (www.exiqon.com). Briefly, the quality of the total RNA was verified by an Agilent 2100 Bioanalyzer. Total RNA from the exosome and the HMC-1 cell samples were labelled with Hy3 and Hy5 fluorescent stain, respectively, using the miRCURY Hy3/Hy5 power labelling kit. The Hy3-labelled exosome samples and a Hy5-labeled mast cells were mixed pair-wise and hybridized to the miRCURY? LNA array (v9.2). The hybridization was performed according to the miRCURY? LNA array manual using a Tecan HS4800 hybridization station (Tecan Systems, Inc. San Jose, CA). The miRCURY? LNA array microarray slides were scanned by a ScanArray 4000 XL scanner (Packard Biochip Technologies, Billerica, MA ,USA) and the image analysis was carried out using the ImaGene 6.1.0 software (BioDiscovery, Inc, El Segundo, CA USA). The quantified signals were normalized using the global Lowess (LOcally WEighted Scatterplot Smoothing) regression algorithm. MicroRNA with signals equal to or below the background signal in 2 or more of the 4 replicate measurements were identified as absent in that slide. The limit for a miRNA to be listed as detectable was set to signal intensities higher than 3 x background (3 x median Hy3 or Hy5 for the total slide). In addition, where signals were detected for <3 of the slides, they were considered unreliable and excluded from sets of detected miRNAs. The experiment was performed in triplicate samples. The signal was calculated as the mean value of the log2MeanRatio Hy3/Hy5 for the triplicates M-BM-1 SD. [mRNA profiling] Exosomes were prepared from the supernatant of HMC-1 cells by differential centrifugations and filtration. RNA was isolated from the exosomes and their parental cells using Trizol . The microarray experiments were performed by SweGene (www.swegene.org/) according to Affymetrix microarray DNA chip analysis (n=4). p0739_E1, p0739_ E2, p0739_E3 and p0739_E4 for the exosomes samples and p0739_C1, p0739_C2, p0739_C3, and p0739_C4 for the HMC-1 cells. [miRNA profiling] Exosomes were prepared from the supernatant of HMC-1 cells by differential centrifugations and filtration. RNA was isolated from the exosomes and their parental cells using Trizol followed by RNeasy clean-up. The microarray experiments were performed by Exiqon.

Project description:Chemotherapy resistance frequently drives tumor progression. However, the underlying molecular mechanisms are poorly characterized. Epithelial-to-mesenchymal transition (EMT) has been shown to correlate with therapy resistance, but the functional link and signaling pathways remain to be elucidated. We report here that miR-30c, a human breast tumor prognostic marker, plays a pivotal role in chemo-resistance by a direct targeting of the actintransporter TWF1, which promotes EMT. An IL-6 family member, IL-11 was identified as a secondary target of TWF1 in the miR-30c signaling pathway. Expression of miR-30c inversely correlated with IL-11 expression in clinical tumors and IL-11 correlated with relapse-free survival in breast cancer patients. Identification of a novel miRNA-mediated pathway that regulates chemo-resistance in breast cancer will facilitate the development of new management strategies. For the primary breast tumor and normal breast samples, both mRNAs (Agilent array data deposited in GSE22049) and miRNAs (Exiqon array data deposited here) profiles have been examined. Patient information include age, tumor subtype and outcome etc. When clustering samples and genes 152 of 757 miRNA passed the filtering criteria on variation across samples; standard deviation > 0.50. Hence, the upper 152 miRNAs in the expression matrix were used in the two-way hierarchical clustering of genes. The matrix numbers are all log2(Hy3/Hy5) ratios, meaning sample/pool. The percentages above the matrix indicates the present call in each sample/slide. When calling of a particular miRNA failed on an array this is indicated as a blank in the row containing this miRNA and in the column corresponding to this array. The criteria for deciding that the calling of a miRNA had failed on a particular array, was that 2 or more of the 4 replicated measures of this miRNA were flagged 1 or 2 (i.e. the signal is below background) by the image analysis software. Further in the expression matrix all capture probes with Hy3 and Hy5 signals lower than 1.5x of the median signal intensity of the given slide is indicated as a blank.

Project description:Background: Exosomes are nanovesicles of endocytic origin believed to be involved in communication between cells. Recently, it has been shown that mast cell exosomes contain RNA named "exosomal shuttle RNA". The aim of this study was to evaluate whether exosomal shuttle RNA could play a role in the communication between human mast cells and between human mast cells and human CD34 positive progenitor cells. Results: Exosomes from the human mast cell line HMC-1 contain RNA. The exosomes contain no or very little ribosomal RNA compared to their donor cells. The mRNA and microRNA content in exosomes and their donor cells was examined using microarray analyses. We found 116 microRNA in the exosomes and 134 microRNA in the cells, from which some were expressed at different level. DNA microarray experiments revealed the presence of approximately 1800 mRNAs in the exosomes, which represent 15% of the donor cell mRNA content. Transfer experiments revealed that exosomes and their RNA can transfer to other HMC-1 cells and to CD34 positive progenitors. Conclusions: To conclude, HMC-1 exosomes contain mRNA and microRNA that can be transferred to other mast cells and to CD34 progenitors. This shuttle of exosomal RNA may represent a powerful mode of communication between cells where cells send genetic information to other cells over a distance via exosomes. [miRNA profiling] Identification of microRNA was performed by Exiqon (www.exiqon.com). Briefly, the quality of the total RNA was verified by an Agilent 2100 Bioanalyzer. Total RNA from the exosome and the HMC-1 cell samples were labelled with Hy3 and Hy5 fluorescent stain, respectively, using the miRCURY Hy3/Hy5 power labelling kit. The Hy3-labelled exosome samples and a Hy5-labeled mast cells were mixed pair-wise and hybridized to the miRCURY? LNA array (v9.2). The hybridization was performed according to the miRCURY? LNA array manual using a Tecan HS4800 hybridization station (Tecan Systems, Inc. San Jose, CA). The miRCURY? LNA array microarray slides were scanned by a ScanArray 4000 XL scanner (Packard Biochip Technologies, Billerica, MA ,USA) and the image analysis was carried out using the ImaGene 6.1.0 software (BioDiscovery, Inc, El Segundo, CA USA). The quantified signals were normalized using the global Lowess (LOcally WEighted Scatterplot Smoothing) regression algorithm. MicroRNA with signals equal to or below the background signal in 2 or more of the 4 replicate measurements were identified as absent in that slide. The limit for a miRNA to be listed as detectable was set to signal intensities higher than 3 x background (3 x median Hy3 or Hy5 for the total slide). In addition, where signals were detected for <3 of the slides, they were considered unreliable and excluded from sets of detected miRNAs. The experiment was performed in triplicate samples. The signal was calculated as the mean value of the log2MeanRatio Hy3/Hy5 for the triplicates ± SD.

Project description:This SuperSeries is composed of the following subset Series: GSE24992: Drosophila brain microRNA expression with age: miRNA profiling GSE25007: Drosophila brain gene expression with age: mRNA profiling GSE25008: Drosophila brain gene expression between wildtype and miR-34 null flies Refer to individual Series. Aging is the most prominent risk factor for human neurodegenerative disease, but underlying mechanisms that connect two processes are less well characterized. With age, the brain undergoes functional decline and perhaps degeneration. Such decline may not just contribute to normal aging, but also enhance susceptibility to and progression of age-related neurodegenerative diseases. Therefore, defining intrinsic factors and pathways that underline the normal integrity of the adult nervous system may lead to insights that potentially link aging and neurodegeneration. Here, we report a highly conserved microRNA (miRNA), miR-34, as a modulator of aging and neurodegeneration. Using Drosophila, we show that fly miR-34 expression is brain-enriched and strikingly upregulated with age. Functional studies reveal that, whereas animals without miR-34 are normal as young adults, upon aging, they gradually show late-onset deficits characteristic of accelerated brain aging; these include a transcriptional signature of aged animals, coupled with rapid functional decline, loss of brain integrity, followed by a catastrophic decline in adult viability. Moreover, upregulation of miR-34 protects against neurodegeneration induced by pathogenic human polyglutamine (polyQ) disease protein. We next reveal a dramatic effect of miR-34 to silence the Eip74EF gene of steroid hormone pathways in the adult, which is crucial to maintain the normal aging. Collectively, these data define a miR-34-mediated mechanism that specifically affects long-term integrity of the adult nervous system. miR-34 function in Drosophila may thus present a link that functionally connects aging and neurodegeneration. Our studies implicate essential roles of miRNA- dependent pathways in maintenance of the adult brain, disease pathogenesis and healthy aging.

Project description:Background: T-cell intracellular antigen (TIA) proteins function as regulators of cell homeostasis. These proteins control gene expression globally at multiple levels in response to dynamic regulatory changes and environmental stresses. Herein we identified a micro(mi)RNA signature associated to transiently TIA-depleted HeLa cells and analyzed the potential role of miRNAs combining genome-wide analysis data on mRNA and miRNA profiles. Results: Using high-throughput miRNA expression profiling, transient depletion of TIA-proteins in HeLa cells was observed to promote significant and reproducible changes (>2-fold, FDR<0.0001) affecting to a pool of up-regulated miRNAs (miR-30b*, miR125a-3p, miR-193a-5p, miR-197_MM2, miR-203, miR-210, miR-371-5p, miR-373*, miR-483-5p, miR-492, miR-498, miR-503, miR-572, miR-586, miR-612, miR-615, miR-623, miR-625, miR-629, miR-638, miR-658, miR-663, miR-671, miR-769-3p and miR-744). Differential expression analysis of some miRNAs was validated by reverse transcription and real time PCR. By target prediction and combined analysis of the genome-wide expression profiles of the mRNAs and miRNAs identified in TIA-depleted HeLa cells, we detected concomitant connections between up-regulated miRNAs and putative and experimental targeted mRNAs. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes database analyses suggest that targeted mRNAs are related with biological processes associated to the regulation of DNA-dependent transcription, signal transduction and multicellular organismal development as well as with the enrichment of pathways in cancer, focal adhesion, regulation of actin cytoskeleton and MAPK and Wnt signalling pathways, respectively. Conclusion: All this considered, these observations suggest that specific miRNAs could act as potential mediators of the epigenetic switch linking transcriptomic dynamics and cell phenotypes mediated by TIA proteins. The analysis includes two cell types. Three biological replicates were performed per cell type and they were compared by using three dual-channel microarray hybridizations.

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The Expression of MicroRNA and microRNA Clusters in the Aging Heart

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The expression of microRNA and microRNA clusters in the aging heart.

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