ABSTRACT: The human genome harbors a large number of sequences encoding for RNAs that are not translated but control cellular functions by distinct mechanisms. The expression and function of the longer transcripts namely the long non-coding RNAs (lncRNAs) in the vasculature is largely unknown. Here, we characterized the expression of lncRNAs in human endothelial cells and elucidated the function of the highly expressed metastasis-associated lung adenocarcinoma transcript 1 (MALAT1; also known as MALAT-1 or NEAT2). Endothelial cells of different origin express high levels of the conserved lncRNAs MALAT1, TUG1, MEG, linc00657 and linc00493. MALAT1 was significantly increased by hypoxia and controls a phenotypic switch in endothelial cells. Silencing of MALAT1 by siRNAs or GapmeRs induced a pro-migratory response and increased basal sprouting and migration, whereas proliferation of endothelial cells was inhibited. If angiogenesis was further stimulated by VEGF, MALAT1 siRNAs induced discontinuous sprouts indicative of defective proliferation of stalk cells. In vivo studies confirmed that genetic ablation of MALAT1 inhibited proliferation of endothelial cells and reduced neonatal retina vascularization. Gene expression profiling followed by confirmatory qRT-PCR demonstrated that silencing of MALAT1 impaired the expression of various cell cycle regulators. Silencing of MALAT1 tips the balance from a proliferative to a migratory endothelial cell phenotype in vitro and its genetic deletion reduces neonatal vascular growth in vivo.
Project description:The human genome harbors a large number of sequences encoding for RNAs that are not translated but control cellular functions by distinct mechanisms. The expression and function of the longer transcripts namely the long non-coding RNAs (lncRNAs) in the vasculature is largely unknown. Here, we characterized the expression of lncRNAs in human endothelial cells and elucidated the function of the highly expressed metastasis-associated lung adenocarcinoma transcript 1 (MALAT1; also known as MALAT-1 or NEAT2). Endothelial cells of different origin express high levels of the conserved lncRNAs MALAT1, TUG1, MEG, linc00657 and linc00493. MALAT1 was significantly increased by hypoxia and controls a phenotypic switch in endothelial cells. Silencing of MALAT1 by siRNAs or GapmeRs induced a pro-migratory response and increased basal sprouting and migration, whereas proliferation of endothelial cells was inhibited. If angiogenesis was further stimulated by VEGF, MALAT1 siRNAs induced discontinuous sprouts indicative of defective proliferation of stalk cells. In vivo studies confirmed that genetic ablation of MALAT1 inhibited proliferation of endothelial cells and reduced neonatal retina vascularization. Gene expression profiling followed by confirmatory qRT-PCR demonstrated that silencing of MALAT1 impaired the expression of various cell cycle regulators. Silencing of MALAT1 tips the balance from a proliferative to a migratory endothelial cell phenotype in vitro and its genetic deletion reduces neonatal vascular growth in vivo. Human endothelial polyA+ RNA expression analysis. We used two replicate samples of human umbilical vein endothelial cells.
Project description:The long noncoding MALAT1 RNA is upregulated in cancer tissues and its elevated expression is associated with hyper-proliferation, but the underlying mechanism is poorly understood. We demonstrate that MALAT1 levels are regulated during normal cell cycle progression. Genome-wide transcriptome analyses in normal human diploid fibroblasts reveal that MALAT1 modulates the expression of cell cycle genes, and is required for G1/S and mitotic progression. Depletion of MALAT1 leads to activation of p53 and its target genes. The cell cycle defects observed in MALAT1-depleted cells are sensitive to p53 levels, indicating that p53 is a major downstream mediator of MALAT1 activity. Furthermore, MALAT1-depleted cells display reduced expression of B-MYB (Mybl2), an oncogenic transcription factor involved in G2/M progression, due to altered binding of splicing factors on B-MYB pre-mRNA and aberrant alternative splicing. In human cells, MALAT1 promotes cellular proliferation by modulating the expression and/or premRNA processing of cell cycle-regulated transcription factors. These findings provide mechanistic insights on the role of MALAT1 in regulating cellular proliferation. Keywords: MALAT1; MALAT-1, NEAT2, ncRNA; E2F, alternative splicing; pre-mRNA splicing factors WI38 cells (normal human diploid fibroblasts) were transfected with a control oligo (CTR) or antisense oligos to MALAT1 and RNA was isolated after 48 hr. Two antisense oligos were use for MALAT1 (AS-1 and AS-2). Arrays were done for 3 sets of samples in triplicate (control, AS-1 and AS-2).
Project description:The long noncoding MALAT1 RNA is upregulated in cancer tissues and its elevated expression is associated with hyper-proliferation, but the underlying mechanism is poorly understood. We demonstrate that MALAT1 levels are regulated during normal cell cycle progression. Genome-wide transcriptome analyses in normal human diploid fibroblasts reveal that MALAT1 modulates the expression of cell cycle genes, and is required for G1/S and mitotic progression. Depletion of MALAT1 leads to activation of p53 and its target genes. The cell cycle defects observed in MALAT1-depleted cells are sensitive to p53 levels, indicating that p53 is a major downstream mediator of MALAT1 activity. Furthermore, MALAT1-depleted cells display reduced expression of B-MYB (Mybl2), an oncogenic transcription factor involved in G2/M progression, due to altered binding of splicing factors on B-MYB pre-mRNA and aberrant alternative splicing. In human cells, MALAT1 promotes cellular proliferation by modulating the expression and/or premRNA processing of cell cycle-regulated transcription factors. These findings provide mechanistic insights on the role of MALAT1 in regulating cellular proliferation. Keywords: MALAT1; MALAT-1, NEAT2, ncRNA; E2F, alternative splicing; pre-mRNA splicing factors
Project description:Here we show that the 5’ end and 3’ end of Malat1 are dependently and independently expressed. Loss of 5’ Malat1 up-regulates Neat1 in cis, while loss of 3’ Malat1 globally regulated gene expression in trans. Furthermore, loss of 3’ Malat1 accelerates premature aging and shortens the lifespan in mice, but loss of 5’ Malat1 produces no phenotypic changes. Mechanistically, 3’ Malat1 exerts a tight regulation of P21 that is drastically up-regulated in brain and retina upon its deletion in mice. This is very likely mediated at two different levels. One is at the mRNA level since Malat1 interacts with hnRNP A1 and hnRNP A2/B1. This is independently of P53 since it is significantly decreased upon 3’ Malat1 KO, probably due to the down-regulation of hnRNP C which has been shown to maintain P53 mRNA stability in our cell line model. The other is at the protein level through NPM, which is significantly up-regulated in 3’ Malat1 KO and which was known to decrease P21 ubiquitination and hence stabilizing of P21. These observations reveal previously unknown functions of 3’ Malat in the brain and indicates the need for more detailed understanding of highly abundant conserved lncRNAs, such as Malat1, and alarms for detailed understanding before therapeutic targeting in the future.
Project description:Intra- and extracellular metabolomics dataset of human dermal blood endothelial cells (HDBECs), human umbilical vein endothelial cells (HUVECs), human dermal lymphatic endothelial cells (HDLECs) and intestinal lymphatic endothelial cells (iLECs) in proliferation and quiescence.
Project description:The long noncoding RNA MALAT1 (metastasis-associated lung adenocarcinoma transcript 1), also known as MALAT-1 or NEAT2 (nuclear-enriched abundant transcript 2), is a highly conserved nuclear noncoding RNA (ncRNA). Two molecular functions of MALAT1 have been proposed, one is the control of alternative splicing and the other is the transcriptional regulation. To uncover its function in HCC, we knock down it in human HCC LM3 cell lines, and profiling the sample with LC/MS/MS and RNA sequencing.
Project description:We have described role of Malat1 in cardiomyocyte proliferation and binucleation. Data shows regulated genes by LNA mediated silencing of Malat1
Project description:Long noncoding RNAs (lncRNAs) are non-protein coding RNAs regulating gene expression. Although for some lncRNAs a relevant role in hypoxic endothelium has been shown, the regulation and function of lncRNAs is still largely unknown in the vascular physio-pathology. Taking advantage of next-generation sequencing techniques, transcriptomic changes induced by endothelial cell exposure to hypoxia were investigated. Paired-end sequencing of polyadenylated RNA derived from human umbilical vein endothelial cells (HUVECs) exposed to 1% O2 or normoxia was performed. Bioinformatics analysis identified â 2000 differentially expressed genes, including 122 lncRNAs. Extensive validation was performed by both microarray and qPCR. Among the validated lncRNAs, H19, MIR210HG, MEG9, MALAT1 and MIR22HG were also induced in a mouse model of hindlimb ischemia. To test the functional relevance of lncRNAs in endothelial cells, knockdown of H19 expression was performed. H19 inhibition decreased HUVEC growth, inducing their accumulation in G1 phase of the cell cycle; accordingly, p21 (CDKN1A) expression was increased. Additionally, H19 knockdown also diminished HUVEC ability to form capillary like structures when plated on matrigel. In conclusion, a high-confidence signature of lncRNAs modulated by hypoxia in HUVEC was identified and a significant impact of H19 lncRNA was shown. For H19 knock-down, 50 nM of antisense LNA⢠GapmeRs customer-designed for H19 or Negative control A (Exiqon) were transfected by siRNA transfection reagent (Santa Cruz Biotechnology) in 40% confluent HAOEC according to the manufacturerâs manual.
Project description:Long noncoding RNAs (lncRNAs) are non-protein coding RNAs regulating gene expression. Although for some lncRNAs a relevant role in hypoxic endothelium has been shown, the regulation and function of lncRNAs is still largely unknown in the vascular physio-pathology. Taking advantage of next-generation sequencing techniques, transcriptomic changes induced by endothelial cell exposure to hypoxia were investigated. Paired-end sequencing of polyadenylated RNA derived from human umbilical vein endothelial cells (HUVECs) exposed to 1% O2 or normoxia was performed. Bioinformatics analysis identified â 2000 differentially expressed genes, including 122 lncRNAs. Extensive validation was performed by both microarray and qPCR. Among the validated lncRNAs, H19, MIR210HG, MEG9, MALAT1 and MIR22HG were also induced in a mouse model of hindlimb ischemia. To test the functional relevance of lncRNAs in endothelial cells, knockdown of H19 expression was performed. H19 inhibition decreased HUVEC growth, inducing their accumulation in G1 phase of the cell cycle; accordingly, p21 (CDKN1A) expression was increased. Additionally, H19 knockdown also diminished HUVEC ability to form capillary like structures when plated on matrigel. In conclusion, a high-confidence signature of lncRNAs modulated by hypoxia in HUVEC was identified and a significant impact of H19 lncRNA was shown. HUVEC were exposed to normoxia or 24 and 48 hours of hypoxia (1% oxygen). For each time point and condition was performed in duplicate was produced Total RNAs of six samples were extracted and analysed.
Project description:Long noncoding RNAs (lncRNAs) are non-protein coding RNAs regulating gene expression. Although for some lncRNAs a relevant role in hypoxic endothelium has been shown, the regulation and function of lncRNAs is still largely unknown in the vascular physio-pathology. Taking advantage of next-generation sequencing techniques, transcriptomic changes induced by endothelial cell exposure to hypoxia were investigated. Paired-end sequencing of polyadenylated RNA derived from human umbilical vein endothelial cells (HUVECs) exposed to 1% O2 or normoxia was performed. Bioinformatics analysis identified â 2000 differentially expressed genes, including 122 lncRNAs. Extensive validation was performed by both microarray and qPCR. Among the validated lncRNAs, H19, MIR210HG, MEG9, MALAT1 and MIR22HG were also induced in a mouse model of hindlimb ischemia. To test the functional relevance of lncRNAs in endothelial cells, knockdown of H19 expression was performed. H19 inhibition decreased HUVEC growth, inducing their accumulation in G1 phase of the cell cycle; accordingly, p21 (CDKN1A) expression was increased. Additionally, H19 knockdown also diminished HUVEC ability to form capillary like structures when plated on matrigel. In conclusion, a high-confidence signature of lncRNAs modulated by hypoxia in HUVEC was identified and a significant impact of H19 lncRNA was shown Total RNA was extracted from two independent experiments with different time-points of hypoxia exposure (1% oxygen). HUVEC were exposed to 24h normoxia and 24h hypoxia or to 24h normoxia and 48h hypoxia. Each experiment was performed in duplicate.