ABSTRACT: To investigate the expression of pancreatic miRNAs during the period of perinatal beta-cell expansion and maturation in rats, RNA was extracted from whole pancreas at embryonic day 20 (E20), on the day of birth (P0) and two days after birth (P2) and hybridized to miRCURY LNA microRNA Arrays ver.8.1 (Exiqon). Labeling swaps were performed for technical duplicates of each sample. A common reference pool was generated by combining the three biologically different RNA pools from all three time points. All samples were analysed against this common reference.
Project description:Invariant Natural killer T (iNKT) cells are a separate lineage of T lymphocytes with innate effector functions. They express an invariant TCR specific for lipids presented by CD1d and their development and effector differentiation rely on a unique gene expression program. We asked whether this program includes microRNAs, small non-coding RNAs that regulate gene expression posttranscriptionally and play key role in the control of cellular differentiation programs. We identified a miRNA profile specific for iNKT cells, which exhibits features of activated/effector T lymphocytes. In this experiment we compared microRNAs of NKT cells versus those of conventional T lymphocytes, both extracted from wild type mouse thymus. To produce the populations we enriched mature thymocytes and then sorted NKT cells and conventional T cells (from one sorting we obtain one â??NKTâ?? sample and one â??Tâ?? sample). We performed the experiment in triplicate; the sample NKT 1 was sorted the same day of the sample T 1, NKT 2 with T 2, NKT 3 with T 3. We used a common reference approach for the 6 samples; as a common reference we produced RNA from total thymocytes, without the enrichment for mature cells and without the sorting; we pooled thymocytes derived from all the thymi used in the study. The aim of the experiment was to demonstrate that NKT cells have a microRNA profile different from that of conventional T cells.
Project description:We report the identification of microRNA-138 (miR-138), as a molecular signature of GSCs and demonstrate a vital role for miR-138 to promote growth and survival of bona fide tumor-initiating cells with self-renewal potential. Total RNA from Glioma Stem Cells and Neural Stem Cells were subjected to microRNA microarray analysis, 3 replicates each.
Project description:The goal of this study was to investigate the generation and normalization of microRNA expression data based on microarray technologies to comparatively assess their quality. Two profiling platforms were compared: the single-channel Affymetrix GeneChip(r) and the Exiqon dual-channel miRCURY LNA(tm), which was processed as a single-channel array. Due to fundamental differences in the platform constitution, the normalization methods developed for gene expression need to be applied very cautiously to microRNA raw data. This motivated the development of a novel normalization method based on controllable assumptions, which uses the intensities of spike-in control probes. The results showed that the novel normalization method reduced the data variability in the most consistent way and confirmed the reliability of the differentially expressed microRNAs obtained, based on an RT-qPCR experiment performed for a subset of microRNAs. The conclusion was that the Exiqon platform combined with the novel spike-in controls based normalization method provides high-quality microRNA expression data suitable for reliable downstream analysis. This preprocessing pipeline was implemented into an R package called ExiMiR and deposited in the Bioconductor repository. Data generated in a sister experiment on the Affymetrix platform has been submitted to ArrayExpress under accession E-MTAB-875.
Project description:Organotypic culture of human primary bronchial epithelial cells is a useful in vitro system to study normal biological processes and lung disease mechanisms, to develop new therapies, and to assess the biological perturbations induced by environmental pollutants. Herein, we further develop this in vitro model as a standard human airway assay by comparing the biological response observed after cigarette smoke (CS) exposure in vitro and published data from human bronchial epithelium of smokers. To this end, we exposed differentiated normal human bronchial epithelial cells (AIR-100 tissue) to mainstream CS for 7, 14, 21, or 28 min at the air-liquid interface and investigated various biological endpoints (e.g., gene expression and microRNA profiles, MMP-1 release) at multiple post-exposure time points (0.5, 2, 4, 24, 48 hours).
Project description:Comparison of miRNA profiles of wildtype and lin-28(n719); lin-46(ma164) Caenorhabditis elegans nematodes at the L1 stage Two genotypes, wildtype vs. mutant. Biological replicates: 3 wild type, 3 mutant, independently grown and harvested. One replicate per slide.
Project description:This SuperSeries is composed of the following subset Series: GSE30513: MicroRNA expression profiling of Ewing sarcoma cancer stem cells GSE31144: MicroRNA expression profiling of Ewing sarcoma cell lines upon TARBP2 depletion GSE31145: MicroRNA expression profiling of Ewing sarcoma spheres vs. adherent cells Refer to individual Series
Project description:We have recently demonstrated that human paediatric mesenchymal stem cells can be reprogrammed toward a Ewing’s sarcoma family tumor (ESFT) cancer stem cell (CSC) phenotype by mechanisms that implicate microRNAs (miRNAs). Here, we show that the miRNA profile of ESFT CSC is shared by embryonic stem cells and CSC from divergent tumor types. We also provide evidence that the miRNA profile of ESFT CSC is the result of reversible disruption of TARBP2-dependent miRNA maturation. Restoration of TARBP2 activity and systemic delivery of synthetic forms of either of two of its targets, miRNA-143 or miRNA-145, inhibited ESFT CSC clonogenicity and tumor growth in vivo. Our observations suggest that CSC self-renewal and tumor initiation may depend on deregulation of TARBP2-dependent miRNA expression. 3 Ewing sarcoma cell lines: comparison between TARBP2 silencing by shRNA and control.
Project description:We have recently demonstrated that human paediatric mesenchymal stem cells can be reprogrammed toward a Ewing’s sarcoma family tumor (ESFT) cancer stem cell (CSC) phenotype by mechanisms that implicate microRNAs (miRNAs). Here, we show that the miRNA profile of ESFT CSC is shared by embryonic stem cells and CSC from divergent tumor types. We also provide evidence that the miRNA profile of ESFT CSC is the result of reversible disruption of TARBP2-dependent miRNA maturation. Restoration of TARBP2 activity and systemic delivery of synthetic forms of either of two of its targets, miRNA-143 or miRNA-145, inhibited ESFT CSC clonogenicity and tumor growth in vivo. Our observations suggest that CSC self-renewal and tumor initiation may depend on deregulation of TARBP2-dependent miRNA expression. 2 Ewing sarcoma primary samples: comparison between spheres and derived adherent cells.
Project description:MicroRNA expression in the mouse eye.MicroRNAs (miRNAs) are key regulators of biological processes. To define miRNA function in the eye, it is essential to determine a high-resolution profile of their spatial and temporal distribution. In this report, we present the first comprehensive survey of miRNA expression in ocular tissues, using both microarray and RNA in situ hybridization (ISH) procedures. We initially determined the expression profiles of miRNAs in the retina, lens, cornea and retinal pigment epithelium of the adult mouse eye by microarray. Each tissue exhibited notably distinct miRNA enrichment patterns and cluster analysis identified groups of miRNAs that showed predominant expression in specific ocular tissues or combinations of them. Next, we performed RNA ISH for over 220 miRNAs, including those showing the highest expression levels by microarray, and generated a high-resolution expression atlas of miRNAs in the developing and adult wild-type mouse eye, which is accessible in the form of a publicly available web database. We found that 122 miRNAs displayed restricted expression domains in the eye at different developmental stages, with the majority of them expressed in one or more cell layers of the neural retina . This analysis revealed miRNAs with differential expression in ocular tissues and provided a detailed atlas of their tissue-specific distribution during development of the murine eye. The combination of the two approaches offers a valuable resource to decipher the contributions of specific miRNAs and miRNA clusters to the development of distinct ocular structures. microRNA profiling of ocular tissues from mouse. In particular we analysed the cornea, lens, Retina Pigment Epithelium (RPE) and retina and compared them against RNA extracted from the entire eye. The purpose of this experiment was to understand which microRNAs are present nd/or show differential expression in the various structures of the eye (cornea, lens, RPE, retina). The samples numbered 1 & 2 (i.e. CORNEA1, CORNEA2 etc ) are biological replicates, prepared from tissues dissecyed from different groups of wild-type animals. RNA extracted from the entire eye (EYE) served as the unique reference sample. For each tissue to be analysed we performed the following hybridizations: - 2 slides for lens (LENS1, LENS2) vs entire eye (EYE) - 2 slides for RPE (RPE1, RPE2) vs entire eye (EYE) - 2 slides for retina (RETINA1, RETINA2) vs entire eye (EYE) - 2 slides for cornea (CORNEA1, CORNEA2) vs entire eye (EYE) - 1 slide for entire eye (EYE) vs entire eye (EYE)