Project description:Specificity of interaction between a microRNA (miRNA) and its targets crucially depends on the seed region located in its 5’-end. It is often implicitly considered that two miRNAs sharing the same biological activity should display similarity beyond the strict six nucleotide region that forms the seed, in order to form specific complexes with the same mRNA targets. We have found that expression of hsa-miR-147b and hsa-miR-210, though triggered by different stimuli (i.e. lipopolysaccharides and hypoxia, respectively), induce very similar cellular effects in term of proliferation, migration and apoptosis. Hsa-miR-147b only shares a “minimal” 6-nucleotides seed sequence with hsa-miR-210, but is identical with hsa-miR-147a over 20 nucleotides, except for one base located in the seed region. Phenotypic changes induced after heterologous expression of miR-147a strikingly differ from those induced by miR-147b or miR-210. In particular, miR-147a behaves as a potent inhibitor of cell proliferation and migration. These data fit well with the gene expression profiles observed for miR-147b and miR-210, which are very similar, and the gene expression profile of miR-147a, which is distinct from the two others. Bioinformatics analysis of all human miRNA sequences indicates multiple cases of miRNAs from distinct families exhibiting the same kind of similarity that would need to be further characterized in terms of putative functional redundancy. Besides, it implies that functional impact of some miRNAs can be masked by robust expression of miRNAs belonging to distinct families. To compare the set of transcripts targeted by hsa-miR-147a, hsa-miR-147b and hsa-miR-210, we overexpressed these miRNAs in human lung adenocarcinoma A549 cells by transfecting them with synthetic pre-miRNAs or a synthetic “negative” pre-miRNA as a control (miR-Neg). RNA samples were harvested at 48 hours post-transfection and 3 independent experiments were carried out. 48 hours post-transfection, 3 independent experiments were performed in dye-swap: hsa-miR-147a versus miR-Neg; hsa-miR-147b versus miR-Neg; hsa-miR-210 versus miR-Neg.
Project description:Specificity of interaction between a microRNA (miRNA) and its targets crucially depends on the seed region located in its 5’-end. It is often implicitly considered that two miRNAs sharing the same biological activity should display similarity beyond the strict six nucleotide region that forms the seed, in order to form specific complexes with the same mRNA targets. We have found that expression of hsa-miR-147b and hsa-miR-210, though triggered by different stimuli (i.e. lipopolysaccharides and hypoxia, respectively), induce very similar cellular effects in term of proliferation, migration and apoptosis. Hsa-miR-147b only shares a “minimal” 6-nucleotides seed sequence with hsa-miR-210, but is identical with hsa-miR-147a over 20 nucleotides, except for one base located in the seed region. Phenotypic changes induced after heterologous expression of miR-147a strikingly differ from those induced by miR-147b or miR-210. In particular, miR-147a behaves as a potent inhibitor of cell proliferation and migration. These data fit well with the gene expression profiles observed for miR-147b and miR-210, which are very similar, and the gene expression profile of miR-147a, which is distinct from the two others. Bioinformatics analysis of all human miRNA sequences indicates multiple cases of miRNAs from distinct families exhibiting the same kind of similarity that would need to be further characterized in terms of putative functional redundancy. Besides, it implies that functional impact of some miRNAs can be masked by robust expression of miRNAs belonging to distinct families.
Project description:Compulsory expression of miR-210 in normal endometrial stromal cells directed the induction of cell proliferation and vascular endothelial growth factor production, and the inhibition of apoptosis in through signal transducer and activator of transcription 3 (STAT3) activation. Accumulating evidence suggests that microRNAs play definite roles in the pathogenesis of endometriosis. The objective of the study was to determine the role of miR-210, one of the upregulated microRNA in endometriotic cyst stromal cells, in the pathogenesis of endometriosis. Downstream targets of miR-210 were identified by Compulsory expression of miR-210 in normal eutopic endometrial stromal cells, a global mRNA microarray technique, and Ingenuity pathways analysis. NESCs were transfected with precursor hsa-miR-210 (Pre-miRTM miRNA precursor- hsa-miR-210, Ambion, Austin, TX, USA) or negative control precursor miRNA (Pre-miRTM miRNA precursor-negative control #1 Ambion) at a final concentration of 10 nM, using LipofectamineTM RNAiMAX (Invitrogen, Carlsbad, CA, USA). Forty-eight hours after transfection, total RNA from cultured NESCs transfected with precursor hsa-miR-210 (n=4) and NESCs (n=4) transfected with negative control precursor miRNA was extracted with an RNeasy Mini kit (Qiagen, Valencia, CA, USA). Then, the samples were subjected to a gene expression microarray analysis with a commercially available human mRNA microarray (G4845A, Human Gene Expression 4x44K v2, Agilent Technologies, Santa Clara, CA, USA).
Project description:To gain insights into the in vivo function of miRNAs in the context of periodontitis, we examined the occurrence of miRNAs in healthy and diseased gingival tissues and validated their in silico-predicted targets through mRNA profiling using whole-genome microarrays in the same specimens. Eighty-six individuals with periodontitis contributed 198 gingival papillae: 158 'diseased' (bleeding-on-probing, PD > 4 mm, and AL ≥ 3 mm) and 40 'healthy' (no bleeding, PD ≤ 4 mm, and AL ≤ 2 mm). Expression of 1,205 miRNAs was assessed by microarrays, followed by selected confirmation by quantitative RT-PCR. Predicted miRNA targets were identified and tested for enrichment by Gene Set Enrichment Analysis (GSEA). Enriched gene sets were grouped in functional categories by DAVID and Ingenuity Pathway Analysis. One hundred fifty-nine miRNAs were significantly differentially expressed between healthy and diseased gingiva. Four miRNAs (hsa-miR-451, hsa-miR-223, hsa-miR-486-5p, hsa-miR-3917) were significantly overexpressed, and 7 (hsa-miR-1246, hsa-miR-1260, hsa-miR-141, hsa-miR-1260b, hsa-miR-203, hsa-miR-210, hsa-miR-205*) were underexpressed by > 2-fold in diseased vs. healthy gingiva. GSEA and additional filtering identified 60 enriched miRNA gene sets with target genes involved in immune/inflammatory responses and tissue homeostasis. This is the first study that concurrently examined miRNA and mRNA expression in gingival tissues and will inform mechanistic experimentation to dissect the role of miRNAs in periodontal tissue homeostasis and pathology.
Project description:To gain insights into the in vivo function of miRNAs in the context of periodontitis, we examined the occurrence of miRNAs in healthy and diseased gingival tissues and validated their in silico-predicted targets through mRNA profiling using whole-genome microarrays in the same specimens. Eighty-six individuals with periodontitis contributed 198 gingival papillae: 158 'diseased' (bleeding-on-probing, PD > 4 mm, and AL M-bM-^IM-% 3 mm) and 40 'healthy' (no bleeding, PD M-bM-^IM-$ 4 mm, and AL M-bM-^IM-$ 2 mm). Expression of 1,205 miRNAs was assessed by microarrays, followed by selected confirmation by quantitative RT-PCR. Predicted miRNA targets were identified and tested for enrichment by Gene Set Enrichment Analysis (GSEA). Enriched gene sets were grouped in functional categories by DAVID and Ingenuity Pathway Analysis. One hundred fifty-nine miRNAs were significantly differentially expressed between healthy and diseased gingiva. Four miRNAs (hsa-miR-451, hsa-miR-223, hsa-miR-486-5p, hsa-miR-3917) were significantly overexpressed, and 7 (hsa-miR-1246, hsa-miR-1260, hsa-miR-141, hsa-miR-1260b, hsa-miR-203, hsa-miR-210, hsa-miR-205*) were underexpressed by > 2-fold in diseased vs. healthy gingiva. GSEA and additional filtering identified 60 enriched miRNA gene sets with target genes involved in immune/inflammatory responses and tissue homeostasis. This is the first study that concurrently examined miRNA and mRNA expression in gingival tissues and will inform mechanistic experimentation to dissect the role of miRNAs in periodontal tissue homeostasis and pathology. The dataset comprise 200 gingival tissue samples from 86 patients with periodontitis. All samples are included in this series, but 2 where not included in the study, as they did not pass our QC. Each patient has one or more healthy and disease sample and samples can be of chronic or aggressive periodontitis type.
Project description:Since the seed sequence is shifted between canonical and isomer variant of hsa-miR-34b-5p and hsa-miR-449c-5p, we examine whether the transfection of the different forms of these miRNAs results in distinct targetomes
Project description:Since the early 1980s remarkable progress has been made in understanding the role of the HER2 locus in carcinogenesis, but many details of its regulatory network are still elusive. We recently reported the finding of 367 new human microRNA (miRNA) genes of which one, mir-4728, is encoded in an intron of the HER2 gene. Here, we confirm that the HER2 oncogene is a bi-functional locus encoding the membrane receptor and a functional miRNA gene. We further show that miR-4728-3p has alternative functionalities depending on the region used for interaction with its target; the canonical seed between nucleotides 2-8 or a novel, more internal seed shifted to nucleotides 6-12. Analysis of public data shows that this internal seed region, although rare compared to the far more abundant canonical 2-8 seed interaction, can also direct targeted down-regulation by other miRNAs. Through the internal seed, miR-4728-3p regulates expression of estrogen receptor alpha, an interaction that would have remained undetected if classic rules for miRNA-target interaction had been applied. In summary, we present here an alternative mode of miRNA regulation and demonstrate this dual function of the HER2 locus, linking the two major biomarkers in breast cancer. 6 samples treated with hsa-miR-4728-3p mimic and 6 samples treated with non-targeting control 4 samples treated with hsa-miR-1-3p mimic and 4 samples treated with non-targeting control