Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

MicroRNAs and their isomiRs function cooperatively to target common biological pathways (Illumina expression beadchip)

ABSTRACT: Variants of microRNAs, (isomiRs) are commonly reported in deep-sequencing studies; however the functional significance of these variants remains controversial. To assess their biological relevance, we have performed ultra-deep miRNA-seq on ten adult human tissues, and created an analysis pipeline (miRNA-MATE) to align, annotate, and analyze miRNAs and their isomiRs. We find that isomiRs share sequence and expression characteristics with canonical miRNAs, and are generally strongly correlated with canonical miRNA expression. We isolated polyribosome-associated mRNA, and captured the mRNA-bound miRNAs, and found that isomiRs and canonical miRNAs are equally associated with translational machinery. Finally, we transfected cells with biotinylated RNA duplexes encoding isomiRs or their canonical counterparts and directly assayed their mRNA targets. These studies showed substantial overlap in functional mRNA networks suppressed by both canonical miRNAs and their isomiRs. Together, these results find isomiRs to be biologically relevant and functionally synergistic partners of canonical miRNAs that act coordinately to target pathways of functionally related genes. This work exposes the complexity of the miRNA-transcriptome, and helps explain a major miRNA paradox: how specific regulation of biological processes can occur with predominantly non-specific miRNA-mRNA interactions. HEK293T cells were transfected with biotinylated miRNAs (either mir-10a-iso, mir-10a, mir-10b-iso or mir-10b) or a mock control. The miRNAs and target mRNA were pulled down with streptavidin. The pulled down RNA was hybridised to Illumina microarrays. The miRNA-Seq data have been submitted to the short read archive under SRA number SRP006043: http://www.ncbi.nlm.nih.gov/sra?term= SRP006043

ORGANISM(S): Homo sapiens

SUBMITTER: Nic Waddell

PROVIDER: E-GEOD-29043 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

ACCESS DATA

Similar Datasets

Project description:MicroRNAs (miRNAs) are single-stranded non-coding RNAs that negatively regulate target gene expression through mRNA cleavage or translational repression. There is mounting evidence that they play critical roles in heart disease. The expression of known miRNAs in the heart has been studied at length by microarray and quantitative PCR but it is becoming evident that microRNA isoforms (isomiRs) are potentially physiologically important. It is well known that left ventricular (patho)physiology is influenced by transmural heterogeneity of cardiomyocyte phenotype, and this likely reflects underlying heterogeneity of gene expression. Given the significant role of miRNAs in regulating gene expression, knowledge of how the miRNA profile varies across the ventricular wall will be crucial to better understand the mechanisms governing transmural physiological heterogeneity. To determinine miRNA/isomiR expression profiles in the rat heart we investigated tissue from different locations across the left ventricular wall using deep sequencing. We detected significant quantities of 145 known rat miRNAs and 68 potential novel orthologs of known miRNAs, in mature, mature* and isomiR formation. Many isomiRs were detected at a higher frequency than their canonical sequence in miRBase and have different predicted targets. The most common miR-133a isomiR was more effective at targeting a construct containing a sequence from the gelsolin gene than was canonical miR-133a, as determined by dual-fluorescence assay. We identified a novel rat miR-1 homolog from a second miR-1 gene; and a novel rat miRNA similar to miR-676. We also cloned and sequenced the rat miR-486 gene which is not in miRBase (v18). Signalling pathways predicted to be targeted by the most highly detected miRNAs include Ubiquitin-mediated Proteolysis, Mitogen-Activated Protein Kinase, Regulation of Actin Cytoskeleton, Wnt signalling, Calcium Signalling, Gap junctions and Arrhythmogenic Right Ventricular Cardiomyopathy. Most miRNAs are not expressed in a gradient across the ventricular wall, with exceptions including miR-10b, miR-21, miR-99b and miR-486.

Dataset Information

MicroRNAs and their isomiRs function cooperatively to target common biological pathways (Illumina expression beadchip)

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets