Dicer-microRNA-Myc circuit promotes transcription of hundreds of long noncoding RNAs
ABSTRACT: Long noncoding RNAs (lncRNAs) are important regulators of cell fate, and their mis-expression has been implicated in many diseases. While distinct polymerases generate messenger vs. noncoding ribosomal or tRNAs3, little is known about distinct mechanisms controlling lncRNA expression. Here we show that transcription of lncRNAs is quantitatively different from that of messenger RNAs (mRNAs)--as revealed by deficiency of Dicer (Dcr), a key ribonuclease that generates microRNAs (miRNAs). Loss of Dcr in mouse embryonic stem cells (mESCs) led surprisingly to decreased level of the majority of lncRNAs. The canonical Dgcr8-Dcr-miRNA pathway is required for robust lncRNA expression, at the level of transcriptional initiation and elongation of lncRNA genes rather than at the level of their stability. cMyc, an oncogenic transcription factor, whose expression is indirectly regulated by Dcr-miRNA in mESCs, is partly responsible for lncRNA transcription. Loss of cMyc led to a more dramatic decrease of lncRNAs than mRNAs, and cMyc overexpression rescues lncRNA expression in Dcr KO cells. A quantitative metric of “mRNA-lncRNA decoupling” revealed that Dcr and cMyc differentially regulate lncRNAs vs. mRNAs in diverse cell types and in vivo, as evidenced by hundreds of microarray experiments. Thus, Dcr and cMyc may allow numerous lncRNAs to be activated or deactivated as a class, implicating lncRNAs to potential regulatory roles in development and disease states where Dcr and cMyc have been associated with. RNA was sequenced from WT and Dcr KO mESCs and the expression of lncRNAs and mRNAs are compared between WT and Dcr KO mESCs.
Project description:Long noncoding RNAs (lncRNAs) are important regulators of cell fate, yet little is known about mechanisms controlling lncRNA expression. Here we show that transcription is quantitatively different for lncRNAs and mRNAs--as revealed by deficiency of Dicer (Dcr), a key RNase that generates microRNAs (miRNAs). Dcr loss in mouse embryonic stem cells led unexpectedly to decreased levels of hundreds of lncRNAs. The canonical Dgcr8-Dcr-miRNA pathway is required for robust lncRNA transcriptional initiation and elongation. Computational and genetic epistasis analyses demonstrated that Dcr activation of the oncogenic transcription factor cMyc is partly responsible for lncRNA expression. A quantitative metric of mRNA-lncRNA decoupling revealed that Dcr and cMyc differentially regulate lncRNAs versus mRNAs in diverse cell types and in vivo. Thus, numerous lncRNAs may be modulated as a class in development and disease, notably where Dcr and cMyc act.
Project description:The regulatory role of long noncoding RNAs (lncRNAs) have been partially proved in embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs).In the current study, we investigated mouse ESC (mESC) self-renewal, differentiation, and proliferation in vitro by knocking down a lncRNA, growth arrest specific 5 (Gas5). A series of related indicators were examined by cell counting kit-8 (CCK-8) assay, quantitative reverse-transcription polymerase chain reaction (qRT-PCR), Western blot, alkaline phosphatase staining, propidium iodide (PI) staining, Annexin V staining, competition growth assay, immunofluorescence, and chromatin immunoprecipitation (ChIP)-qPCR. An in vivo teratoma formation assay was also performed to validate the in vitro results. qRT-PCR, fluorescence-activated cell sorting (FACS), alkaline phosphatase staining, and immunofluorescence were used to evaluate the role of Gas5 during mouse iPSC reprogramming. The regulatory axis of Dicer-miR291a-cMyc-Gas5 and the relationship between Gas5 and Tet/5hmC in mESCs was examined by qRT-PCR, Dot blot, and Western blot.We identified that Gas5 was required for self-renewal and pluripotency of mESCs and iPSCs. Gas5 formed a positive feedback network with a group of key pluripotent modulators (Sox2, Oct4, Nanog, Tcl1, Esrrb, and Tet1) in mESCs. Knockdown of Gas5 promoted endodermal differentiation of mESCs and impaired the efficiency of iPSC reprogramming. In addition, Gas5 was regulated by the Dicer-miR291a-cMyc axis and was involved in the DNA demethylation process in mESCs.Taken together, our results suggest that the lncRNA Gas5 plays an important role in modulating self-renewal and pluripotency of mESCs as well as iPSC reprogramming.
Project description:Recently, a handful of intergenic long noncoding RNAs (lncRNAs) have been shown to compete with mRNAs for binding to miRNAs and to contribute to development and disease. Beyond these reports, little is yet known of the extent and functional consequences of miRNA-mediated regulation of mRNA levels by lncRNAs. To gain further insight into lncRNA-mRNA miRNA-mediated crosstalk, we reanalyzed transcriptome-wide changes induced by the targeted knockdown of over 100 lncRNA transcripts in mouse embryonic stem cells (mESCs). We predicted that, on average, almost one-fifth of the transcript level changes induced by lncRNAs are dependent on miRNAs that are highly abundant in mESCs. We validated these findings experimentally by temporally profiling transcriptome-wide changes in gene expression following the loss of miRNA biogenesis in mESCs. Following the depletion of miRNAs, we found that >50% of lncRNAs and their miRNA-dependent mRNA targets were up-regulated coordinately, consistent with their interaction being miRNA-mediated. These lncRNAs are preferentially located in the cytoplasm, and the response elements for miRNAs they share with their targets have been preserved in mammals by purifying selection. Lastly, miRNA-dependent mRNA targets of each lncRNA tended to share common biological functions. Post-transcriptional miRNA-mediated crosstalk between lncRNAs and mRNA, in mESCs, is thus surprisingly prevalent, conserved in mammals, and likely to contribute to critical developmental processes.
Project description:βΒ2-crystallin (CRYBB2) is expressed at an increased level in the postnatal lens cortex and is associated with cataracts. Improved understanding of the underlying biology of cataracts is likely to be critical for the development of early detection strategies and new therapeutics. The present study aimed to identify long non-coding RNAs (lncRNAs) and mRNAs associated with CRYBB2 knockdown (KO)-induced cataracts. RNAs from 3 non-treated mice and 3 CRYBB2 KO mice were analyzed using the Affymetrix GeneChip Mouse Gene 2.0 ST array. A total of 149 lncRNAs and 803 mRNAs were identified to have upregulated expression, including Snora73b, Klk1b22 and Rnu3a, while the expression levels of 180 lncRNAs and 732 mRNAs were downregulated in CRYBB2 KO mice, including Snord82, Snhg9 and Foxn3. This lncRNA and mRNA expression profile of mice with CRYBB2 KO provides a basis for studying the genetic mechanisms of cataract progression.
Project description:Although the functional roles of long noncoding RNAs (lncRNAs) have been increasingly identified, few lncRNAs that control the naïve state of embryonic stem cells (ESCs) are known. Here, we report a naïve-state-associated lncRNA, LincU, which is intrinsically activated by Nanog in mESCs. LincU-deficient mESCs exhibit a primed-like pluripotent state and potentiate the transition from the naïve state to the primed state, whereas ectopic LincU expression maintains mESCs in the naïve state. Mechanistically, we demonstrate that LincU binds and stabilizes the DUSP9 protein, an ERK-specific phosphatase, and then constitutively inhibits the ERK1/2 signaling pathway, which critically contributes to maintenance of the naïve state. Importantly, we reveal the functional role of LincU to be evolutionarily conserved in human. Therefore, our findings unveil LincU as a conserved lncRNA that intrinsically restricts MAPK/ERK activity and maintains the naïve state of ESCs.
Project description:Long non-coding RNAs (lncRNAs) represent an emerging layer of cancer biology, contributing to tumor proliferation, invasion, and metastasis. Here, we describe a role for the oncogenic lncRNA PCAT-1 in prostate cancer proliferation through cMyc. We find that PCAT-1-mediated proliferation is dependent on cMyc protein stabilization, and using expression profiling, we observed that cMyc is required for a subset of PCAT-1-induced expression changes. The PCAT-1-cMyc relationship is mediated through the post-transcriptional activity of the MYC 3' untranslated region, and we characterize a role for PCAT-1 in the disruption of MYC-targeting microRNAs. To further elucidate a role for post-transcriptional regulation, we demonstrate that targeting PCAT-1 with miR-3667-3p, which does not target MYC, is able to reverse the stabilization of cMyc by PCAT-1. This work establishes a basis for the oncogenic role of PCAT-1 in cancer cell proliferation and is the first study to implicate lncRNAs in the regulation of cMyc in prostate cancer.
Project description:A few reports have implicated specific lncRNAs in cardiac development or failure, but precise details of lncRNAs expressed in hearts and how their expression may be altered during embryonic heart development or by adult heart disease is unknown. By comparing lncRNA profiles of normal embryonic (~E14), normal adult, and hypertrophied adult hearts we defined a distinct fetal lncRNA abundance signature that includes 157 lncRNAs differentially expressed compared to adults (fold-change ≥ 50%, FDR=0.02), and which was only poorly recapitulated in hypertrophied hearts (17 differentially expressed lncRNAs; 13 of these observed in embryonic hearts). Analysis of protein-coding mRNAs from the same samples identified 22 concordantly and 11 reciprocally regulated mRNAs within 10 kb of dynamically expressed lncRNAs, reciprocal relationships of lncRNA and mRNA levels was validated for the Mccc1 and Relb genes using in vitro lncRNA knockdown in C2C12 cells. Network analysis suggested a central role for lncRNAs in modulating NFkappaB- and CREB1-regulated genes during embryonic heart growth and identified multiple mRNAs within these pathways that are also regulated, but independently of lncRNAs. Cardiac polyadenylated RNA (mRNA and lncRNA) profiles were generated from C57BL/6J mouse hearts were generated on Illumina HiSeq 2000 instruments. 7 independent E13.5 hearts, 12 adult hearts (6 at 6 weeks of age, 6 at 16 weeks of age), 4 sham-operated hearts at 12 weeks of age, and 4 hearts after 4 weeks of pressure overload (TAC) at 12 weeks of age.
Project description:LncRNA and mRNA microarrays were performed to identify differentially expressed lncRNAs and mRNAs in fibroblast-like synoviocytes from rheumatoid arthritis patients compared with fibroblast-like synoviocytes from trauma patients. Fibroblast-like synoviocytes were isolated from synovial tissues. LncRNA and mRNA microarrays were performed using fibroblast-like synoviocytes at passage 3.
Project description:The lncRNA expression profiles in three pairs of hTERT-positive gastric cancer tissue sand hTERT-negative para-cancerous tissues. The para-cancerous tissue is at least 5cm away from the cancer tissue. The expression of hTERT of identified by immunohistochemistry before RNA extraction for lncRNA assay. LncRNAs/mRNAs in 3 gastric cancer tissue and 3 paired para-cancerous tissue (Control) by microarray using Arraystar Human LncRNA Microarray v2.0
Project description:BACKGROUND:Sepsis represents a complex disease with dysregulated inflammatory response and high mortality rate. Long noncoding RNAs (lncRNAs) have been reported to play regulatory roles in a variety of biological processes. However, studies evaluating the function of lncRNAs in pediatric sepsis are scarce, and current knowledge of the role of lncRNAs in pediatric sepsis is still limited. The present study explored the expression patterns of both lncRNAs and mRNAs between pediatric sepsis patients and healthy controls based on a comprehensive microarray analysis. METHODS:LncRNA and mRNA microarray was used to detect the expression of lncRNAs and mRNAs in the septic and control groups. Aberrantly expressed mRNAs and lncRNAs identified were further interpreted by enrichment analysis, receiver operating characteristic (ROC) curve analysis, co-expression network analysis, and quantitative real-time PCR (qPCR). RESULTS:A total of 1488 differetially expressed lncRNAs and 1460 differentially expressed mRNAs were identified. A co-expression network of the identified lncRNAs and mRNAs was constructed. In this network, lncRNA lnc-RP11-1220?K2.2.1-7 is correlated with mRNA CXCR1 and CLEC4D; lncRNA lnc-ANXA3-2 is correlated with mRNA CLEC4D; lncRNA lnc-TRAPPC5-1 is correlated with mRNA DYSF and HLX; lncRNA lnc-ZNF638-1 is correlated with mRNA DYSF and HLX. Significantly different expressions between pediatric sepsis patients and controls were validated by qPCR for the 4 lncRNAs and 4 co-expressed mRNAs, validating the microarray results. CONCLUSIONS:Our study contributes to a comprehensive understading of the involvment of lncRNAs and mRNAs in pediatric sepsis, which may guide subsequent experimental research. Furthermore, our study may also provide potential candidate lncRNAs and mRNAs for the diagnosis and treatment of pediatric sepsis.