Project description:Long noncoding RNAs (lncRNAs) play important roles in various biological processes; however, few have been identified that regulate hepatic stellate cells (HSCs) activation and the progression of liver fibrosis. Through a detailed analysis of the expression of lncRNAs in various tissues, we discovered the existence of a liver enriched lncRNA-LFAR1 (lncRNA-Liver Fibrosis Associated RNA1). To identify the roles of lncRNA-LFAR1 in liver fiboris, we systematically analyzed the regulation of mRNAs in primary HSCs infected with two separated lnc-LFAR1-shRNAs by RNA-seq, which revealed a panel of mRNAs that were specifically regulated by lncRNA-LFAR1 in mouse primary HSCs.
Project description:Among the large, diverse set of mammalian long noncoding RNAs (lncRNAs), long noncoding primary microRNAs (lnc-pri-miRNAs) are those that host miRNAs. Whether lnc-pri-miRNA loci have important biological function independent of their cognate miRNAs is poorly understood. From a genome-scale lncRNA screen, lnc-pri-miRNA loci were enriched for function in cell proliferation, and in glioblastoma (i.e., GBM) cells with DGCR8 or DROSHA knockdown, lnc-pri-miRNA screen hits still regulated cell growth. To molecularly dissect the function of a lnc-pri-miRNA locus, we studied LOC646329 (also known as MIR29HG), which hosts the miR-29a/b1 cluster. In GBM cells, LOC646329 knockdown reduced miR-29a/b1 levels, and these cells exhibited decreased growth. However, genetic deletion of the miR-29a/b1 cluster (LOC646329-miR29Δ) did not decrease cell growth, while knockdown of LOC646329-miR29Δ transcripts reduced cell proliferation. The miR-29a/b1-independent activity of LOC646329 corresponded to enhancer-like activation of a neighboring oncogene (MKLN1), regulating cell propagation. The LOC646329 locus interacts with the MKLN1 promoter, and antisense oligonucleotide knockdown of the lncRNA disrupts these interactions and reduces the enhancer-like activity. More broadly, analysis of genome-wide data from multiple human cell types showed that lnc-pri-miRNA loci are significantly enriched for DNA looping interactions with gene promoters as well as genomic and epigenetic characteristics of transcriptional enhancers. Functional studies of additional lnc-pri-miRNA loci demonstrated cognate miRNA-independent enhancer-like activity. Together, these data demonstrate that lnc-pri-miRNA loci can regulate cell biology via both miRNA-dependent and miRNA-independent mechanisms.
Project description:Cellular quiescence is coupled with cellular development, tissue homeostasis, and cancer progression. Both quiescence and cell cycle re-entry are controlled by active and precise regulation of gene expression. However, the roles of long noncoding RNAs (lncRNAs) during these processes remain to be elucidated. By performing a genome-wide transcriptome analyses, we identify thousands of differentially expressed lncRNAs, including ~30 of the less-characterized class of microRNA-host-gene lncRNAs (lnc-MIRHGs), during cellular quiescence and during serum-stimulation in human diploid cells. We observe that the mature MIR222HG display serum-stimulated induction due to enhanced pre-RNA splicing. Serum-stimulated binding of the pre-mRNA splicing factor SRSF1 to a micro-exon, which partially overlaps with the primary miR-222 precursor, facilitates enhanced MIR222HG splicing. In serum-stimulated cells, SRSF1 negatively regulates the Drosha/DGCR8-catalyzed cleavage of pri-miR-222, thereby increasing the cellular pool of the mature MIR222HG. Further, loss-of-function studies indicate that the mature MIR222HG facilitates the serum-stimulated cell cycle re-entry in a microRNA-independent manner. Mechanistically, MIR222HG, along with ILF3/2 complex, forms RNA:RNA duplex with DNM3OS lncRNA, thereby promoting DNM3OS stability. The current study identifies a mechanism in which the interplay between splicing versus microprocessor complex dictates the serum-induced expression of lnc-MIRHG MIR222HG for efficient cell cycle re-entry.
Project description:Recent studies have indicated important roles for long noncoding RNAs (lncRNAs) as potential essential regulators of myogenesis and adult skeletal muscle regeneration. However, in vivo, the role and mechanism of lncRNAs in myogenic differentiation of adult skeletal muscle stem cells (MuSCs) and myogenesis are still largely unknown. Here, we identified a skeletal muscle specific-enriched lncRNA (myogenesis-associated lncRNA, short for lnc-mg). In vivo, skeletal muscle conditional knockout of lnc-mg resulted in muscle atrophy and the loss of muscular endurance during exercise. Alternatively, skeletal muscle-specific overexpression of lnc-mg promoted muscle hypertrophy in mice. In vitro analyses of primary skeletal muscle cells isolated from mice showed that expression of lnc-mg was increased gradually during myogenic differentiation and overexpressed lnc-mg improved cell differentiation. Mechanistically, lnc-mg promoted myogenesis, by functioning as a competing endogenous RNA (ceRNA) for miR-125b to control protein abundance of Igf2. These findings identify lnc-mg as a novel and important noncoding regulator for muscle cell differentiation and skeletal muscle development. In order to test the hypothesis that lnc-mg may function as a ceRNA leading to the liberation of corresponding miRNA-targeted transcripts, microarrays were performed to detect miRNAs expression in lnc-mg overexpression and lnc-mg knockdown C2C12 cells.
Project description:GM0637 cell were treated with or without DNA damaging agent neocarzinostatin (NCS), and cells were harvested after 4 hours and 8 hours for the microarray analyses of whole-genome long noncoding RNAs. To examine how long noncoding RNAs are regulated in the DNA damage response, we assessed the genome-wide long noncoding RNA expression in GM0637 cells treated with or without DNA damage
Project description:Head and neck squamous cell carcinoma (HNSCC) is the most common malignant tumor in the oral and maxillofacial regions, and long noncoding RNAs (lncRNAs) play crucial roles in the occurrence and progression of HNSCC. in our study, quantified m6A RNA methylation and dot blot assays revealed that total m6A methylation in HNSCC cells was accompanied by lnc-H2AFV-1 expression. Western blotting showed that the expression of methyltransferase-like 3 (METTL3) and 14 (METTL14) was consistent with that of lnc-H2AFV-1, whereas the expression of demethylase fat mass and obesity-associated (FTO) was contrary to that of lnc-H2AFV-1. Methylated RNA immunoprecipitation sequencing (MeRIP-seq) and MeRIP-qPCR were used to determined the target genes regulated by lnc-H2AFV-1 overexpression in HNSCC cells.
Project description:Recent studies have indicated important roles for long noncoding RNAs (lncRNAs) as potential essential regulators of myogenesis and adult skeletal muscle regeneration. However, in vivo, the role and mechanism of lncRNAs in myogenic differentiation of adult skeletal muscle stem cells (MuSCs) and myogenesis are still largely unknown. Here, we identified a skeletal muscle specific-enriched lncRNA (myogenesis-associated lncRNA, short for lnc-mg). In vivo, skeletal muscle conditional knockout of lnc-mg resulted in muscle atrophy and the loss of muscular endurance during exercise. Alternatively, skeletal muscle-specific overexpression of lnc-mg promoted muscle hypertrophy in mice. In vitro analyses of primary skeletal muscle cells isolated from mice showed that expression of lnc-mg was increased gradually during myogenic differentiation and overexpressed lnc-mg improved cell differentiation. Mechanistically, lnc-mg promoted myogenesis, by functioning as a competing endogenous RNA (ceRNA) for miR-125b to control protein abundance of Igf2. These findings identify lnc-mg as a novel and important noncoding regulator for muscle cell differentiation and skeletal muscle development. In order to identify functional lncRNAs correlating with myogenesis, microarrays were performed to detect the lncRNAs expression profile in undifferentiated MuSCs (GM, growth media/GM) ) and differentiated MuSCs (DM, differentiation media/DM).
Project description:Long noncoding RNAs (lncRNAs) have emerged as key regulators in a wide range of biological processes. The involvement of lncRNAs in epithelial-to-mesenchymal transition (EMT) has been well stablished; however, the role as immediate-early regulators is still unclear. Here, we identified a mouse miRNA-host gene lncRNA (lnc-Nr6a1) early upregulated during EMT. We show that this lncRNA is processed giving rise to abundant polyadenylated isoforms, lnc-Nr6a1 and lnc-Nr6a1-2, and a longer non-polyadenylated microprocessor-driven lnc-pri-miRNAS containing clustered pre-miRNA-181a2 and pre-miRNA-181b2 hairpins. Ectopic expression of lnc-Nr6a1-1/2 isoforms enhance cell migration and invasive capacity of the cells, whereas the expression of isoforms and miR-181a2/b2 confers anoikis resistance. Lnc-Nr6a1 gene deletion results in cells with lower adhesion capacity and reduced glycolytic metabolism which are restored by lnc-Nr6a1-1 isoform expression. We perform identification of direct RNA interacting proteins (iDRIP) to identify proteins interacting directly with lnc-Nr6a1-1 isoform. We define a network of interacting proteins, including glycolytic enzymes, desmosome proteins and chaperone proteins and we demonstrated that lnc-Nr6a1-1 isoform directly binds and acts as a scaffold molecule for the assembly of ENO1, ALDOA, GAPDH, PKM glycolytic enzymes along with LDHA, supporting substrate canneling for efficient glycolysis. Our results unveil a role of lnc-Nr6a1 as a multifunctional lncRNA acting as a backbone for multiprotein complexes formation and as a primary microRNAs reservoir.
Project description:Long noncoding RNAs (lncRNAs) have emerged as key regulators in a wide range of biological processes. The involvement of lncRNAs in epithelial-to-mesenchymal transition (EMT) has been well stablished; however, the role as immediate-early regulators is still unclear. Here, we identified a mouse miRNA-host gene lncRNA (lnc-Nr6a1) early upregulated during EMT. We show that this lncRNA is processed giving rise to abundant polyadenylated isoforms, lnc-Nr6a1 and lnc-Nr6a1-2, and a longer non-polyadenylated microprocessor-driven lnc-pri-miRNAS containing clustered pre-miRNA-181a2 and pre-miRNA-181b2 hairpins. Ectopic expression of lnc-Nr6a1-1/2 isoforms enhance cell migration and invasive capacity of the cells, whereas the expression of isoforms and miR-181a2/b2 confers anoikis resistance. Lnc-Nr6a1 gene deletion results in cells with lower adhesion capacity and reduced glycolytic metabolism which are restored by lnc-Nr6a1-1 isoform expression. We perform identification of direct RNA interacting proteins (iDRIP) to identify proteins interacting directly with lnc-Nr6a1-1 isoform. We define a network of interacting proteins, including glycolytic enzymes, desmosome proteins and chaperone proteins and we demonstrated that lnc-Nr6a1-1 isoform directly binds and acts as a scaffold molecule for the assembly of ENO1, ALDOA, GAPDH, PKM glycolytic enzymes along with LDHA, supporting substrate canneling for efficient glycolysis. Our results unveil a role of lnc-Nr6a1 as a multifunctional lncRNA acting as a backbone for multiprotein complexes formation and as a primary microRNAs reservoir.
Project description:Atm+/+ and Atm-/- mouse embryonic fibroblasts were treated with or without DNA damaging agent neocarzinostatin (NCS), and cells were harvested after 4 hours and 8 hours for the microarray analyses of whole-genome long noncoding RNAs. To examine how long noncoding RNAs are regulated in the DNA damage response, we assessed the genome-wide long noncoding RNA expression in Atm+/+ and Atm-/- littermate mouse embryonic fibroblasts (MEFs) treated with or without DNA damage