Project description:Ph-negative myeloproliferative neoplasms (MPNs) are characterized by many somatic mutations which have already been shown useful in the prognostic assessment of MPN patients. Moreover, aberrant microRNA (miRNA) expression seems to add to the molecular complexity of MPNs, as specific miRNA signatures capable of discriminating MPN cells from those of normal donors were previously reported. In order to have a comprehensive picture of miRNA deregulation and its relationship with differential gene expression in primary myelofibrosis (PMF) cells, we obtained gene- (GEP) and miRNA expression profiles (miEP) of CD34+ cells from 31 healthy donors and 42 PMF patients using Affymetrix technology (HG-U219 and miRNA 2.0 arrays). Differentially expressed genes (DEG) and miRNAs (DEM) were sorted out by means of Partek Genomic Suite vs 6.6. Since each miRNA can target many mRNAs while a single mRNA can be targeted by multiple miRNAs, we performed Integrative Analysis (IA) by means of Ingenuity Pathway Analysis (IPA) to untangle this combinatorial complexity. In particular, IPA points out DEM-DEG pairs among experimentally validated interactions from TarBase, miRecords and Ingenuity Expert Findings as well as predicted microRNA-mRNA interactions from TargetScan. IPA microRNA Target Filter was then employed to select only the DEM-DEG pairs showing an anti-correlated expression pattern and to build regulatory networks. Finally, 3'UTR luciferase reporter assays were performed to validate IPA predicted miRNA-mRNA interactions. This study allowed the identification of different networks possibly involved in PMF onset and progression, highlighting an aberrant cross-regulation in miRNA-targets involved in malignant hematopoiesis. Furthermore, Integrative analysis was proved a powerful tool to unravel miRNA-mRNA interactions in functional networks, shedding light on the potential contribution of miRNAs to PMF pathogenesis. Gene expression profile (GEP) and miRNA expression profile (miEP) were performed starting from the same totalRNA of CD34+ cells from 42 PMF patients and 31 healthy donors (n=16 PB CD34+, n=15 BM CD34+) (1 replicate for each sample). In particular, GEP and miEP were performed on 23 PMF patients carrying the mutation JAK2V617F and 19 wild-type samples.
Project description:We have sequenced miRNA libraries from human embryonic, neural and foetal mesenchymal stem cells. We report that the majority of miRNA genes encode mature isomers that vary in size by one or more bases at the 3’ and/or 5’ end of the miRNA. Northern blotting for individual miRNAs showed that the proportions of isomiRs expressed by a single miRNA gene often differ between cell and tissue types. IsomiRs were readily co-immunoprecipitated with Argonaute proteins in vivo and were active in luciferase assays, indicating that they are functional. Bioinformatics analysis predicts substantial differences in targeting between miRNAs with minor 5’ differences and in support of this we report that a 5’ isomiR-9-1 gained the ability to inhibit the expression of DNMT3B and NCAM2 but lost the ability to inhibit CDH1 in vitro. This result was confirmed by the use of isomiR-specific sponges. Our analysis of the miRGator database indicates that a small percentage of human miRNA genes express isomiRs as the dominant transcript in certain cell types and analysis of miRBase shows that 5’ isomiRs have replaced canonical miRNAs many times during evolution. This strongly indicates that isomiRs are of functional importance and have contributed to the evolution of miRNA genes
Project description:We report the application of Illumina short RNA sequencing for characterization and discovery of miRNAs and moRNAs, and for identification of differentially expressed small RNAs in circulating CD34+ cells from Primary Myelofibrosis (PMF) patients and from normal controls pooled bone marrow CD34+ cells. Short RNAs sequencing for miRNA quantification, discovery and characterisation.
Project description:Short RNAs expression profiling in circulating CD34+ cells from Primary Myelofibrosis patients and from normal controls pooled bone marrow CD34+ cells.
Project description:We have sequenced miRNA libraries from human embryonic, neural and foetal mesenchymal stem cells. We report that the majority of miRNA genes encode mature isomers that vary in size by one or more bases at the 3’ and/or 5’ end of the miRNA. Northern blotting for individual miRNAs showed that the proportions of isomiRs expressed by a single miRNA gene often differ between cell and tissue types. IsomiRs were readily co-immunoprecipitated with Argonaute proteins in vivo and were active in luciferase assays, indicating that they are functional. Bioinformatics analysis predicts substantial differences in targeting between miRNAs with minor 5’ differences and in support of this we report that a 5’ isomiR-9-1 gained the ability to inhibit the expression of DNMT3B and NCAM2 but lost the ability to inhibit CDH1 in vitro. This result was confirmed by the use of isomiR-specific sponges. Our analysis of the miRGator database indicates that a small percentage of human miRNA genes express isomiRs as the dominant transcript in certain cell types and analysis of miRBase shows that 5’ isomiRs have replaced canonical miRNAs many times during evolution. This strongly indicates that isomiRs are of functional importance and have contributed to the evolution of miRNA genes Sequence library of miRNAs from a single sample of human foetal mesenchymal stem cells. Results tested and confirmed by northern blotting. Please note that only raw data files are available for the embryonic and neual samples and thus, directly submitted to SRA (SRX547311, SRX548700, respectively under SRP042115/PRJNA247767)
Project description:Primary Myelofibrosis (PMF) is a Philadelphia negative chronic myeloproliferative neoplasm characterized by bone marrow fibrosis, enhanced oxidative stress and high levels of serum pro-inflammatory cytokines. To identify genes and miRNAs potentially involved in PMF pathogenesis, we have previously carried out an integrative analysis of gene and microRNA expression profiles of PMF hematopoietic stem cells (HSPCs), which allowed us to identify miR-382-5p as up-regulated miRNA (Norfo R. et al, Blood 2014). Overexpression experiments in normal CD34+ cells have already demonstrated its central role in HSPC fate decision toward granulocyte lineage (Zini R. et al, Stem Cell Dev 2016). In this study, to further characterized the role of miR-382-5p in PMF pathogenesis, we performed a gene expression profile analysis in normal CD34+ HSPCs overexpressing miR-382-5p. Among the down-regulated genes upon miR-382-5p upregulation, we selected the anti-oxidant superoxide dismutase 2 (SOD2), depicted as the most favorable predicted target by TatgetScan 7.0. Firstly, luciferase reporter assay confirmed SOD2 as a real target of miR-382-5p. Furthermore, we showed that enforced miR-382-5p expression in CD34+ cells reduced SOD2 expression and activity, induced ROS accumulation, and oxidative DNA damages, as well as enhanced CD34+ cell proliferation. Afterwards, to confirm miR-382-5p as a key player in PMF pathogenesis, we performed inhibition experiments in PMF CD34+ cells revealing that miR-382-5p silencing restored SOD2 expression and activity, induced ROS disposal, decreased DNA oxidation and impaired cell proliferation.