Project description:Abnormal mitochondria metabolism and innate immune responses participate in the pathogenesis of many inflammatory disorders. The molecular events regulating mitochondrial activity to control survival and cell death in monocytes/macrophages are poorly understood. Here we show that miR-125b attenuates the activity of the mitochondrial respiratory chain through BIK silencing, and promotes the elongation of mitochondrial network through MTP18 targeting, without impacting autophagy, in the human monocytes. Proinflammatory activation is associated with a concomitant increase in miR-125b expression, decrease in BIK and MTP-18 expression, reduced oxidative phosphorylation, and enhanced mitochondrial fusion. Furthermore, expression of M1-associated transcripts as well as mitochondrial dynamics and energy metabolism are induced upon ectopic expression of miR-125b. In turn, by repressing miR-125b, mitochondrial dynamics was preserved, LPS-induced repression of BIK expression and of mitochondrial respiration were prevented, and M1 polarization of macrophages was inhibited. Altogether, our data reveal a novel role for miR-125b in controlling mitochondrial metabolism and dynamics by targeting BIK and MTP18, respectively, two novel cellular target proteins involved in maintaining the mitochondrial integrity in human monocytes. These findings not only suggest a novel function for miR-125b in regulating metabolic adaptation of monocytes to inflammation but also unravel new molecular mechanisms for its pro-apoptotic role and identify potential targets for interfering with inflammatory activation of monocytes.
Project description:Post-transcriptional regulation of gene expression by miRNAs likely makes significant contributions to mRNA abundance at the embryo-maternal interface. In this study, we investigated how miR-26a-5p and miR-125b-5p contribute to molecular changes occurring in the uterine luminal epithelium, which serves as the first site of signal exchange between the mother and developing embryo. To measure de novo protein synthesis after miRNA delivery to primary uterine luminal epithelial cells, we employed pulsed stable isotope labeling by amino acids (pSILAC). We found that both miRNAs alter the proteome of luminal epithelial cells, impacting numerous cellular functions, immune responses, as well as intracellular and second messenger signaling pathways. Additionally, we identified several features of miRNA-mRNA interactions that may influence the targeting efficiency of miR-26a-5p and miR-125b-5p. Overall, our study suggests a complex interaction of miR-26a-5p and miR-125b-5p with their respective targets. However, both appear to cooperatively function in modulating the cellular environment of the luminal epithelium, facilitating the morphological and molecular changes that occur during the intensive communication between the embryo and uterus at pregnancy.
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:In this study, we characterize the fusion protein produced by the EPC1-PHF1 translocation in Low Grade Endometrial Stromal Sarcoma (LG-ESS) and Ossifying FibroMyxoid Tumors (OFMT). We express the fusion protein and necessary controls in K562 Cells. The fusion protein assembles a mega-complex harboring both NuA4/TIP60 and PRC2 subunits and enzymatic activities and leads to mislocalization of chromatin marks in the genome, linked to aberrant gene expression.
Project description:To assess RNA regulation in the MN possessing mutated FUS-H517D gene. Fused in sarcoma/translated in liposarcoma (FUS) is a causative gene of familial amyotrophic lateral sclerosis (fALS). Mutated FUS causes accumulation of DNA damage stress and stress granule (SG) formation, etc., thereby motor neuron (MN) death. However, key molecular etiology of mutated FUS-dependent fALS (fALS-FUS) remains unclear. Here, Bayesian gene regulatory networks (GRN) calculated by Super-Computer with transcriptome data sets of induced pluripotent stem cell (iPSC)-derived MNs possessing mutated FUSH517D (FUSH517D MNs) and FUSWT identified TIMELESS, PRKDC and miR-125b-5p as "hub genes" which influence fALS-FUS GRNs. miR-125b-5p expression up-regulated in FUSH517D MNs, showed opposite correlations against FUS and TIMELESS mRNA levels as well as reported targets of miR-125b-5p. In addition, ectopic introduction of miR-125b-5p could suppress mRNA expression levels of FUS and TIMELESS in the cells. Furthermore, we found TIMELESS and PRKDC among key players of DNA damage stress response (DDR) were down-regulated in FUSH517D MNs and cellular model analysis validated DDR under impaired DNA-PK activity promoted cytosolic FUS mis-localization to SGs. Our GRNs based on iPSC models would reflect fALS-FUS molecular etiology.
Project description:To investigate the gene expresiion regulated by miR-125b and its isomiRs. We transfected H9C2 cells with respective mimics and performed gene expression profiling anlaysis using data from RNA-seq of mimic controls, miR-125b and its isomiRs mimics subjected to normoxia and hypoxia treatment.