Regulation of microRNA during cardiomyocyte maturation in sheep
ABSTRACT: Background: There is a limited capacity to repair damage in the mammalian heart after birth, which is primarily due to the inability of cardiomyocytes to proliferate after birth. This is in contrast to zebrafish and salamander, in which cardiomyocytes retain the ability to proliferate throughout life and can regenerate their heart after significant damage. Recent studies in zebrafish and rodents implicate microRNAs (miRNAs) in the regulation of genes responsible for cardiac cell cycle progression and regeneration, in particular, miR-133a, the miR-15 family, miR-199a and miR-590. However, the significance of these miRNAs and miRNA in general in the regulation of cardiomyocyte proliferation in large mammals, including humans, where the timing of heart development relative to birth is very different than in rodents, is unclear. To determine the involvement of miRNAs in the down-regulation of cardiomyocyte proliferation occurring before birth in large mammals, we investigated miRNA and target gene expression in sheep hearts before and after birth. The experimental approach included targeted transcriptional profiling of miRNA and target mRNA previously identified in rodent studies as well as genome-wide miRNA profiling using microarrays. Results: The cardiac expression of miR-133a increased and its target gene IGF1R decreased with increasing age, reaching their respective maximum and minimum abundance when the majority of ovine cardiomyocytes were quiescent. The expression of the miR-15 family members was variable with age, however, four of their target genes decreased with age. These latter profiles are inconsistent with the direct involvement of this family of miRNA in cardiomyocyte quiescence in late gestation sheep. The expression patterns of ‘pro-proliferative’ miR-199a and miR-590 were also inconsistent with their involvement in cardiomyocyte quiescence. Consequently, miRNA microarray analysis was undertaken, which identified six discrete clusters of miRNA with characteristic developmental profiles. The functions of predicted target genes for the miRNA in four of the six clusters were enriched for aspects of cell division and regulation of cell proliferation suggesting a potential role of these miRNA in regulating cardiomyocyte proliferation. Conclusion: The results of this study show that the expression of miR-133a and one of its target genes is consistent with it being involved in the suppression of cardiomyocyte proliferation, which occurs across the last third of gestation in sheep. The expression patterns of the miR-15 family, miR-199a and miR-590 were inconsistent with direct involvement in the regulation cardiomyocyte proliferation in sheep, despite studies in rodents demonstrating that their manipulation can influence the degree of cardiomyocyte proliferation. miRNA microarray analysis suggests a coordinated and potentially more complex role of multiple miRNA in the regulation of cardiomyocyte quiescence and highlights significant differences between species that may reflect their substantial differences in the timing of this developmental process. RNA, (2 µg) from three heart samples from each of the 91 d (fetus), 141 d (fetus), 5 d (postnatal) and 173 d (postnatal) groups, was used for analysis according to standard procedures. The experimental design included three biological replicates from each of the four normal developmental ages in sheep and thus a total of 12 samples was analyzed.
Project description:To identify the relevant targets of the selected miRNAs, we assessed global transcriptome changes by deep-sequencing total neonatal mouse cardiomyocyte RNA after transfection with hsa-miR-590-3p or hsa-miR-199a-3p Four condition experiment; one replicate per condition; mouse neonatal cardiomyocytes transfected with cel-miR-67, hsa-miR-590-3p and hsa-miR-199a-3p; samples collected 72 hours after transfection
Project description:Epithelial ovarian cancer (EOC) is the deadliest gynecological cancer. MicroRNAs (miRNAs) are small non-coding RNAs that play important roles in gene regulation and their dysregulation is associated with many diseases. In this study, we determined the expression and function of miR-590-3p in EOC. We found that miR-590-3p levels were higher in high-grade carcinoma when compared to low-grade or tumours with low malignant potential. Interestingly, plasma levels of miR-590-3p were significantly higher in EOC patients than in subjects with benign gynaecological disorders. Transient transfection of miR-590-3p mimics, or stable transfection of mir-590, increased cell growth, migration, and invasion. In vivo studies revealed that mir-590 accelerated tumour growth and metastasis. Using a cDNA microarray, we identified Forkhead box A2 (FOXA2) and Versican (VCAN) as a top downregulated and a top upregulated gene, respectively, by mir-590. We showed that miR-590-3p targeted FOXA2 3’ UTR to suppress its expression. In addition, knockdown of FOXA2 by siRNAs or knockout of FOXA2 by CRISPR/Cas9 enhanced cell proliferation, migration, and invasion. Overexpression of FOXA2 decreased, while knockout of FOXA2 increased, VCAN mRNA and protein levels and ChIP-qPCR revealed that FOXA2 binds to VCAN promoter. Interrogation of the TCGA ovarian cancer database revealed a negative relationship between FOXA2 and VCAN mRNA levels in EOC tumours and that high FOXA2/low VCAN mRNA levels in tumours were positively correlated with patient survival. Finally, overexpression of FOXA2 or silencing of VCAN reversed the effects of mir-590. These findings demonstrate that miR-590-3p promotes EOC development via a novel FOXA2-VCAN pathway. Overall design: A total of 6 samples were analyzed. Three control (EV) and three mir-590 overexpressing samples
Project description:Idiopathic pulmonary fibrosis (IPF) is a chronic and often fatal pulmonary disorder characterized by fibroblast proliferation and the excess deposit of extracellular matrix proteins. The etiology of IPF is unknown, but a central role for microRNAs (miRNAs), a class of small non-coding regulatory RNAs, has been recently suggested. We report the upregulation of miR-199a-5p in mouse lungs undergoing bleomycin-induced fibrosis and also in human biopsies from IPF patients. Levels of miR-199a-5p were increased selectively in myofibroblasts and putative profibrotic effects of miR-199a-5p were further investigated in cultured lung fibroblasts. MiR-199a-5p expression was induced upon TGFβ exposure and ectopic expression of miR-199a-5p was sufficient to promote the pathogenic activation of pulmonary fibroblasts. CAV1, a critical mediator of pulmonary fibrosis, was established as a bona fide target of miR-199a-5p. Finally, we also found an aberrant expression of miR-199a-5p in mouse models of kidney and liver fibrosis, suggesting that dysregulation of miR-199a-5p represents a general mechanism contributing to the fibrotic process. We propose miR-199a-5p as a major regulator of fibrosis that represents a potential therapeutic target to treat fibroproliferative diseases. This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
Project description:Cardiovascular disease is the leading cause of morbidity and mortality in the Western world due to a limited regenerative capacity. In lieu of new muscle synthesis, the human heart replaces necrotic tissue with deposition of a non-contractile scar. In contrast, the adult zebrafish is endowed with a remarkable regenerative capacity, capable of de novo cardiomyocyte (CM) creation and scar tissue resolution when challenged with an acute injury. In these studies, we examined the contributions of the dynamically regulated microRNA, miR-101a, during adult zebrafish heart regeneration. We demonstrate that miR-101a expression is rapidly depleted within 3 days post-amputation (dpa) but is highly upregulated by 7-14 dpa, before returning to uninjured levels at the completion of the regenerative process. Employing heat-inducible transgenic strains and antisense oligonucleotides, we demonstrate that decreases in miR-101a levels at the onset of cardiac injury enhanced CM proliferation. Interestingly, prolonged suppression of miR-101a activity stimulates new muscle synthesis but with defects in scar tissue resolution. Upregulation of miR-101a expression between 7-14 dpa is critical to stimulate remodeling of the scar. Through a series of studies, we identified the proto-oncogene, fosab (cfos) as a potent miR-101a target gene, stimulator of CM proliferation, and inhibitor of scar tissue remodeling. Importantly, combinatorial depletion of fosab and miR-101a activity rescued defects in scar tissue resolution mediated by miR-101a inhibition alone. In summation, our studies indicate that the precise temporal modulation in the miR-101a/fosab genetic axis is critical for coordinating CM proliferation and scar tissue resolution during zebrafish heart regeneration. Pooled cardiac samples from uninjured and regenerating (6hpa) adult fish in biological triplicate.
Project description:Phosphatase and tensin homologue deleted on chromosome 10 (PTEN) is a tumor suppressor that negatively regulates cell survival and proliferation by antagonizing phosphatidylinositol 3-kinase(PI3K)/protein kinase B(PKB/Akt) signaling. Loss of heterozygosity (LOH) of PTEN, reduced expression of PTEN and overexpression of phosphorylated Akt are frequently found in human gastric cancer, and their changes correlate with tumor progression and prognosis. Previous studies have shown that the deregulated miRNAs in human gastric cancer play important roles in gastric cancer cell proliferation, apoptosis and inflammation. However, miRNAs downstream PTEN/Akt signaling is poorly investigated. To clarify whether PTEN is involved in gastric tumorigenesis, we have generated a gastric epithelium specific PTEN knockout mouse which exhibited gastric tumor formation with enhanced cell proliferation.So the objectives of the microarray experiment were to, a) screen miRNAs which might be regulated by PTEN/Akt signaling by comparing the miRNA expression profiles between PTEN deficient and control gastric epithelia. 2) explore the microRNA mechanism involved in gastric cell proliferation and gastric tumorigenesis. miRNA profiling of mouse gastric epithelium,comparing Pten mutant mouse with controls. 4 samples. Experiments in 2 different time point, 20 days and 60 days after birth, 2 Biological replicates. Mutant tissue vs. controls from mixture of 3-4 mouse.
Project description:The high rates of mortality associated with epithelial ovarian cancer (EOC) are a direct consequence of its metastatic nature. Metastasis is dependent on many factors, among which activation of angiogenesis is most significant. Angiogenesis is, in turn, contingent upon the cellular response to hypoxia within the tumor microenvironment. Hypoxia-inducible factor 1 (HIF1) is a transcription factor composed of HIF1alpha and HIF1beta subunits and is the master regulator of the hypoxic response. It is therefore a critical mediator of tumor angiogenesis and metastasis. Regulation of HIF1 is primarily at the level of protein. In normoxia, the HIF1alpha subunit is hydroxylated via an oxygen- and iron-dependent mechanism and targeted for destruction. In hypoxia, low oxygen levels preclude hydroxylation and HIF1alpha is stabilized, allowing for its association with constitutively expressed HIF1beta to form bioactive HIF1. We have identified a novel mechanism of HIF1alpha regulation in EOC cells that involves microRNAs (miRs), ~22 nucleotide, non-coding RNA molecules that repress translation of target mRNAs by binding their 3’ untranslated regions (UTRs). Using microarray and qPCR analysis, we found that levels of miR-199a-1, a miR that is predicted in silico to target the HIF1alpha 3’ UTR, were reduced under hypoxia in EOC cells. We further demonstrated that miR-199a-1 directly targets the HIF1alpha 3’ UTR and overexpression of miR-199a-1 suppresses HIF1alpha protein levels and HIF1-driven gene expression. Moreover, cells stably overexpressing miR-199a-1 exhibit marked defects in migratory ability. These data were corroborated by our in vivo findings, which demonstrated that overexpression of miR-199a-1 causes significant reductions in tumor vessel density and tumor burden in nude mice. These findings provide insight into non-canonical, miR- and iron-based mechanisms of HIF1 regulation that may have important implications in the progression of EOC. Overall design: miRNA expression analysis of A2780 epithelial ovarian cancer cells by microarrays
Project description:In this study, we selected differentially expressed miRNAs through construcing and analyzing the miRNA expression profile during 2-, 6-, and 12- month-old Small Tail Han Sheep ovaries, which provided a theoretical basis for the study of miRNAs regulating the reproduction of Small Tail Han Sheep. RNASeq techniques were used to perform profile analysis for these ovaries. The results showed that 11, 13 and 19 DE miRNAs were identified in 2- vs 6-, 6- vs 12-, and 2- vs 12-month-old ovaries, respectively. In total, 54, 37, and 198 predicted target genes of DE miRNAs were obtained from these three groups, respectively. GO and KEGG analyses showed that, in 2- vs 6-month-olds, the target genes of DE known sheep miRNAs were involved in 102 GO terms and 7 signaling pathways; in 6- vs 12-month-olds, the target genes of DE known sheep miRNAs were involved in 52 GO terms and 3 signaling pathways; and in 2- vs 12-month-olds, the target genes of DE known sheep miRNAs were involved in 88 GO terms and 6 signaling pathways. Three miR–target regulatory networks were constructed based on these DE miRNA–targets. 9 miRNAs were selected to validate the accuracy of miRNA sequencing data by qRT-PCR. The binding sites of oar-miR-432 with RPS6KA1 was validated by a dual luciferase reporter gene detection system. This is the first integrative analysis of miRNA and mRNA expression profiles in Small Tail Han Sheep ovarian development. These data help elucidate the molecular regulatory mechanisms in sheep ovarian development and identify the biomarkers that influence reproductive performance of Small Tail Han Sheep ewe. Overall design: Integrated analysis of miRNA and mRNA expression profiles in 2-, 6-, and 12-month-old Small Tail Han Sheep ovaries by RNAseq techniques which reveals that oar-miR-432 downregulates RPS6KA1 expression
Project description:The high rates of mortality associated with epithelial ovarian cancer (EOC) are a direct consequence of its metastatic nature. Metastasis is dependent on many factors, among which activation of angiogenesis is most significant. Angiogenesis is, in turn, contingent upon the cellular response to hypoxia within the tumor microenvironment. Hypoxia-inducible factor 1 (HIF1) is a transcription factor composed of HIF1alpha and HIF1beta subunits and is the master regulator of the hypoxic response. It is therefore a critical mediator of tumor angiogenesis and metastasis. Regulation of HIF1 is primarily at the level of protein. In normoxia, the HIF1alpha subunit is hydroxylated via an oxygen- and iron-dependent mechanism and targeted for destruction. In hypoxia, low oxygen levels preclude hydroxylation and HIF1alpha is stabilized, allowing for its association with constitutively expressed HIF1beta to form bioactive HIF1. We have identified a novel mechanism of HIF1alpha regulation in EOC cells that involves microRNAs (miRs), ~22 nucleotide, non-coding RNA molecules that repress translation of target mRNAs by binding their 3’ untranslated regions (UTRs). Using microarray and qPCR analysis, we found that levels of miR-199a-1, a miR that is predicted in silico to target the HIF1alpha 3’ UTR, were reduced under hypoxia in EOC cells. We further demonstrated that miR-199a-1 directly targets the HIF1alpha 3’ UTR and overexpression of miR-199a-1 suppresses HIF1alpha protein levels and HIF1-driven gene expression. Moreover, cells stably overexpressing miR-199a-1 exhibit marked defects in migratory ability. These data were corroborated by our in vivo findings, which demonstrated that overexpression of miR-199a-1 causes significant reductions in tumor vessel density and tumor burden in nude mice. These findings provide insight into non-canonical, miR- and iron-based mechanisms of HIF1 regulation that may have important implications in the progression of EOC. miRNA expression analysis of A2780 epithelial ovarian cancer cells by microarrays
Project description:The regulatory role of miRNA in gene expression is an emerging hot new topic in the control of hypometabolism. Sea cucumber aestivation is a complicated physiological process that includes obvious hypometabolism as evidenced by a decrease in the rates of oxygen consumption and ammonia nitrogen excretion, as well as a serious degeneration of the intestine into a very tiny filament. To determine whether miRNAs play an important regulatory roles in this process, the present study analyzed profiles of miRNA expression in the intestine of sea cucumber (Apostichopus japonicus), using Solexa deep sequencing technology. We identified 309 sea cucumber miRNAs, including 19 novel miRNAs specific to sea cucumber. Animals sampled during deep aestivation (DA) after at least 15 days of continuous torpor, were compared with animals from a non-aestivation (NA) state (animals that had passed through aestivation and returned to an active state). We identified 42 differentially expressed miRNAs (RPM (reads per million) >10, |FC| (|fold change|) ≥1, FDR<0.01) during aestivation, which were validated by two other miRNA profiling methods: miRNA microarray and real-time PCR. Among the most prominent miRNA species, miR-200-3p, miR-2004, miR-2010, miR-22, miR-252a, miR-252a-3p and miR-92 were significantly over-expressed during deep aestivation compared with non-aestivation animals. Preliminary analyses of their putative target genes suggest that these miRNAs could play important roles in global transcriptional depression during aestivation. In the present study,we present for the first time, using Solexa sequencing technology, an analysis of the global profile of small RNAs in non-aestivation (NA) and deep aestivation (DA) sea cucumbers. We focus on intestine in the present study because it is the major site responsible for the strong metabolic rate depression seen under deep aestivating conditions and the global expression profile of mRNA from the this organ has also been constructed applying RNA-seq technology in our previous study (Zhao and Chen, unpublished data). A preliminary analysis of the functional relevance of miRNA expression in relation to hypometabolism during aestivation is presented. A miRNA microarray and RT-qPCR were both used to supplement and confirm differentially expressed miRNAs. Our findings provide important new insights into the molecular mechanisms of sea cucumber aestivation.
Project description:To gain insight into the molecular regulation of human heart development, a detailed comparison of the mRNA and miRNA transcriptomes across differentiating human-induced pluripotent stem cell (hiPSC)–derived cardiomyocytes and biopsies from fetal, adult, and hypertensive human hearts was performed. Gene ontology analysis of the mRNA expression levels of the hiPSCs differentiating into cardiomyocytes revealed 3 distinct groups of genes: pluripotent specific, transitional cardiac specification, and mature cardiomyocyte specific. Hierarchical clustering of the mRNA data revealed that the transcriptome of hiPSC cardiomyocytes largely stabilizes 20 days after initiation of differentiation. Nevertheless, analysis of cells continuously cultured for 120 days indicated that the cardiomyocytes continued to mature toward a more adult-like gene expression pattern. Analysis of cardiomyocyte-specific miRNAs (miR-1, miR-133a/b, and miR-208a/b) revealed a miRNA pattern indicative of stem cell to cardiomyocyte specification. A biostatistitical approach integrated the miRNA and mRNA expression profiles revealing a cardiomyocyte differentiation miRNA network and identified putative mRNAs targeted by multiple miRNAs. Together, these data reveal the miRNA network in human heart development and support the notion that overlapping miRNA networks re-enforce transcriptional control during developmental specification. miRNA expression profiling of differentiating human-induced pluripotent stem cell (hiPSC)–derived cardiomyocytes (days 0-120)