Project description:Production of functional proteins requires multiple steps including gene transcription and post-translational processing. MicroRNAs (miRNA) can regulate individual stages of these processes. Despite the importance of the cystic fibrosis transmembrane conductance regulator (CFTR) channel for epithelial anion transport, how its expression is regulated remains uncertain. We discovered that microRNA-138 regulates CFTR expression through its interactions with the transcriptional regulatory protein SIN3A. Treating airway epithelia with a miR-138 mimic increased CFTR mRNA and also enhanced CFTR abundance and transepithelial Cl- permeability independently of elevated mRNA levels. A miR-138 anti-miR had the opposite effects. Importantly, miR-138 altered the expression of many genes encoding proteins that associate with CFTR and may influence its biosynthesis. The most common CFTR mutation, M-NM-^TF508, causes protein misfolding, degradation, and cystic fibrosis. Remarkably, manipulating the miR-138 regulatory network also improved biosynthesis of CFTR-M-NM-^TF508 and restored Cl- transport to cystic fibrosis airway epithelia. This novel miRNA-regulated network directs gene expression from the chromosome to the cell membrane, indicating that an individual miRNA can control a cellular process broader than previously recognized. This discovery also provides new therapeutic avenues for restoring CFTR function to cells affected by the most common cystic fibrosis mutation. 12 samples of Calu-3 cells representing different interventions.
Project description:The purpose of the study is to compare the transcriptomic profile of the airway epithelium generated from bronchial airway epithelial cells isolated from healthy donors (NCF) and patients with cystic fibrosis (CF). Cells were grown at the air-liquid interface for at least 2-months. CF is caused by mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Only patients homozygous for the F508del mutation of the CFTR gene were considered. The reconstituted airway epithelium was mechanically wounded and allowed to repair with time. We considered four steps: 1) intact, non-wounded (NW) epithelium; 2) 24h hours post-wounding (pW); 3) time at which the wound is closed (WC); 4) two days post-wound closure (pWC). We also mimicked infection by exposing the cells to Pseudominas aeruginosa flagelin for NW and WC conditions.
Project description:5’ tRNA-fMet1 half is delivered into cystic fibrosis airway epithelium cells by outer membrane vesicles and regulate gene expression. We used chimeric eCLIP to map transcriptome-wide interactions between 5’ tRNA-fMet1 half and target mRNAs mediated by AGO2.
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:Production of functional proteins requires multiple steps including gene transcription and post-translational processing. MicroRNAs (miRNA) can regulate individual stages of these processes. Despite the importance of the cystic fibrosis transmembrane conductance regulator (CFTR) channel for epithelial anion transport, how its expression is regulated remains uncertain. We discovered that microRNA-138 regulates CFTR expression through its interactions with the transcriptional regulatory protein SIN3A. Treating airway epithelia with a miR-138 mimic increased CFTR mRNA and also enhanced CFTR abundance and transepithelial Cl- permeability independently of elevated mRNA levels. A miR-138 anti-miR had the opposite effects. Importantly, miR-138 altered the expression of many genes encoding proteins that associate with CFTR and may influence its biosynthesis. The most common CFTR mutation, ΔF508, causes protein misfolding, degradation, and cystic fibrosis. Remarkably, manipulating the miR-138 regulatory network also improved biosynthesis of CFTR-ΔF508 and restored Cl- transport to cystic fibrosis airway epithelia. This novel miRNA-regulated network directs gene expression from the chromosome to the cell membrane, indicating that an individual miRNA can control a cellular process broader than previously recognized. This discovery also provides new therapeutic avenues for restoring CFTR function to cells affected by the most common cystic fibrosis mutation.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.