Profiles analysis reveals circRNAs involving zebrafish physiological development
Ontology highlight
ABSTRACT: Recent studies have found that known functions of circRNAs include sequestration of microRNAs or proteins, modulation of transcription and interference with splicing, and even translation to produce poly-peptides. The zebrafish model is also demonstrably similar to humans in many studies. In order to explore the changes in circRNAs during embryonic development, further to research the mechanism of action of circRNAs in development-related diseases. Zebrafish embryos at blastula period, gastrula period, segmentation period, throat stage and incubation period were collected. Illumina deep sequencing technology and CIRI algorithm were used to detecting circRNAs. Totally we identified 1028 circRNAs (junction reads ≥ 5 and p < 0.05). Considering that circRNAs function is related to host genes, then bioinformatics analysis revealed these differentially expressed host genes are involved in NOTCH signaling pathways, cardiovascular system development, retinal ganglion cell axon guidance and so on. Moreover, circRNAs can participate in biological regulation through miRNA sponges function. TargetScan and miRanda were used to predict 73 miRNAs binding to circRNAs such as miR-19b, miR-124 and so on, some miRNAs play important roles in embryogenesis. The peak expression of circRNAs is distributed at different time points, suggesting that it may be involved in embryogenesis at different stages. Our study provides a foundation for understanding the dynamic regulation of circRNA transcriptomes during embryogenesis and identifies novel key circRNAs that might control embryonic development in zebrafish model.
Project description:The synergism between c-MYC and miR-17-19b, a truncated version of the miR-17-92 cluster, is well documented during tumor initiation. However, little is known about miR-17-19b function in established cancers. Here we investigate the role of miR-17-19b in c-MYC-driven lymphomas by integrating SILAC-based quantitative proteomics, transcriptomics and 3’ UTR analysis upon miR-17-19b overexpression. We identify over one hundred novel miR-17-19b targets, of which 40% are co-regulated by c-MYC. Down-regulation of a new miR-17/20 target Chek2 increases the recruitment of HuR to c-MYC transcripts, resulting in the inhibition of c-MYC translation and thus interfering with in vivo tumor growth. Hence, in established lymphomas, miR-17-19b fine-tunes c-MYC activity through a tight control of its function and expression, ultimately ensuring cancer cell homeostasis. Our data highlight the plasticity of miRNA function, reflecting changes in the mRNA landscape and 3’ UTR shortening at different stages of tumorigenesis.
Project description:miR-19b was up-regulated with hepatocellular carcinoma. We compared the transcriptional profile of Hep 3B transfected with miR-19b inhibitor with Hep3B transfected with control to identify genes affected by miR-19b knockdown.
Project description:miR-19b was up-regulated with hepatocellular carcinoma. We compared the transcriptional profile of Hep 3B transfected with miR-19b inhibitor with Hep3B transfected with control to identify genes affected by miR-19b knockdown. Hep 3B_miR-19b transfected vs Hep 3B_control transfected
Project description:Several members from microRNA 17-92 cluster, i.e. miR-19a, miR-19b and miR-20a, were found up-regulated in human epidermal keratinocytes at wound-edges compared to the intact skin; however their biological role in keratinocytes during wound repair has not been studied. To study the genes regulated by miR-19a, miR-19b and miR-20a, we transfected miRNA specific mimics, i.e. pre-miR-19a, pre-miR-19b or pre-miR-20a into human primary epidermal keratinocytes to overexpress them. We performed a global transcriptome analysis of keratinocytes upon overexpression of miR-19a or miR-19b or miR-20a using Affymetrix arrays.
Project description:Systemic sclerosis (SSc) is a chronic autoimmune disease characterized with fibrosis of skin and multiple vital organs, but the immunological pathogenesis of SSc remains largely unknown. We show here that microRNA-19b (miR-19b) promotes IL-9-producing CD4+ T cells (Th9) that exacerbate SSc. Specifically, TGF-b plus IL-4 induced expression of TNF receptor associated factor 6 (TRAF6) through phosphorylated Smad3 linker region site Serine 213 (p-Smad3L-Ser213) and activated it through K63 ubiquitination by suppressing the leucine-rich-repeat-containing protein 3 (NLRC3). TRAF6 consequently formed complex with and activated TGF-b activated kinase 1 (TAK1). TAK1 promoted nuclear factor kappa B (NFκB) p65 activation, which then specifically upregulated miR-19b. miR-19b activated Il9 gene expression and promoted Th9 differentiation by directly targeting and suppressing atypical E2F family member E2f8 gene, a repressor for Il9 gene transcription. Importantly, Th9 cells played a critical role in the development and pathogenesis of experimental SSc by promoting the fibrosis in mice induced with Bleomycin. miR-19b and IL-9 were increased in CD4+ T cells in experimental SSc in mice and also in patients with SSc. Strikingly, inhibition of miR-19b resulted in fewer Th9 cells and attenuated fibrotic manifestations and ameliorated the disease in SSc mice. Our study identifies miR-19b as a key factor of Th9 cells that are involved in the pathogenesis of SSc. Our findings should have clinical implications for patients with SSc.
Project description:Circular RNAs (circRNAs) in animals are an enigmatic class of RNAs with unknown function. To systematically explore circRNAs, we sequenced and computationally analyzed human, mouse and nematode RNA. We detected thousands of well-expressed, stable circRNAs, with oftentimes tissue/developmental stage specific expression. Sequence analysis suggested important regulatory functions for circRNAs. Indeed, we discovered that human circRNA CDR1as is densely bound by miRNA effector complexes and harbors 63 conserved binding sites for the ancient miRNA miR-7. Further analyses indicated that CDR1as functions to bind miR-7 in neuronal tissues. Human CDR1as expression in zebra fish impaired midbrain development similar to knocking down miR-7, suggesting that CDR1as is a miRNA antagonist with a miRNA binding capacity ten times higher than any other known transcript. Together, our data provide evidence that circRNAs form a large class of post-transcriptional regulators. Numerous circRNAs form by head-to-tail splicing of exons, indicating previously unrecognized regulatory potential of coding sequences. 1 Sample
Project description:Circular RNAs (circRNAs) in animals are an enigmatic class of RNAs with unknown function. To systematically explore circRNAs, we sequenced and computationally analyzed human, mouse and nematode RNA. We detected thousands of well-expressed, stable circRNAs, with oftentimes tissue/developmental stage specific expression. Sequence analysis suggested important regulatory functions for circRNAs. Indeed, we discovered that human circRNA CDR1as is densely bound by miRNA effector complexes and harbors 63 conserved binding sites for the ancient miRNA miR-7. Further analyses indicated that CDR1as functions to bind miR-7 in neuronal tissues. Human CDR1as expression in zebra fish impaired midbrain development similar to knocking down miR-7, suggesting that CDR1as is a miRNA antagonist with a miRNA binding capacity ten times higher than any other known transcript. Together, our data provide evidence that circRNAs form a large class of post-transcriptional regulators. Numerous circRNAs form by head-to-tail splicing of exons, indicating previously unrecognized regulatory potential of coding sequences. PARCLIP was performed as in Hafner et. al Cell 2010 with HEK293 cell lines stably expressing HIS/FLAG/HA-tagged AGO1 or AGO2. We used 4-thiouridine (4SU) to enhance the crosslink and generated cDNA libraries.
Project description:iPSC-derived neurons were treated with mimics and inhibitors of the miRNAs miR-150-5p, hsa-mir-193a-3p and hsa-miR-19b-3p.
RNA-sequencing was then performed to examine the effects of miRNA up-regulation and inhibition.
Project description:Background: Early embryonic developmental programs are guided by the coordinated interplay between maternally inherited and zygotically manufactured RNAs and proteins. Although these processes happen concomitantly and affecting gene function during this period is bound to affect both pools of mRNAs, it has been challenging to study their expression dynamics separately. Results: By employing Slam-seq, a nascent mRNA labeling transcriptomic approach, in a developmental time series we observe that over half of the early zebrafish embryo transcriptome consists of maternal-zygotic genes, emphasizing their pivotal role in early embryogenesis. We provide an hourly resolution of de novo transcriptional waves and follow nascent mRNA trajectories, finding that most de novo transcriptional events are stable throughout this period. Additionally, by blocking microRNA430 function, a key post-transcriptional regulator during zebrafish embryogenesis, we directly show that it destabilizes hundreds of de novo transcribed mRNAs from pure zygotic as well as maternal-zygotic genes. This unveils a novel miR-430 function during embryogenesis, fine-tuning zygotic gene expression, which highlights that Slam-seq can be used to disentangle transcriptional and post-transcriptional regulation of mRNA levels. Conclusion: Such valuable insights into zebrafish early embryo transcriptome dynamics emphasize the significance of post-transcriptional regulators in zygotic genome activation. These findings pave the way for future investigations into the coordinated interplay between transcriptional and post-transcriptional landscapes required for the establishment of animal cell identities and functions.
Project description:Background: Early embryonic developmental programs are guided by the coordinated interplay between maternally inherited and zygotically manufactured RNAs and proteins. Although these processes happen concomitantly and affecting gene function during this period is bound to affect both pools of mRNAs, it has been challenging to study their expression dynamics separately. Results: By employing Slam-seq, a nascent mRNA labeling transcriptomic approach, in a developmental time series we observe that over half of the early zebrafish embryo transcriptome consists of maternal-zygotic genes, emphasizing their pivotal role in early embryogenesis. We provide an hourly resolution of de novo transcriptional waves and follow nascent mRNA trajectories, finding that most de novo transcriptional events are stable throughout this period. Additionally, by blocking microRNA430 function, a key post-transcriptional regulator during zebrafish embryogenesis, we directly show that it destabilizes hundreds of de novo transcribed mRNAs from pure zygotic as well as maternal-zygotic genes. This unveils a novel miR-430 function during embryogenesis, fine-tuning zygotic gene expression, which highlights that Slam-seq can be used to disentangle transcriptional and post-transcriptional regulation of mRNA levels. Conclusion: Such valuable insights into zebrafish early embryo transcriptome dynamics emphasize the significance of post-transcriptional regulators in zygotic genome activation. These findings pave the way for future investigations into the coordinated interplay between transcriptional and post-transcriptional landscapes required for the establishment of animal cell identities and functions.