PubMed HealthSearch

SEARCH · PubMed Health

Results for “Enhancer RNAs”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources

A long noncoding RNA with enhancer-like function in pig zygotic genome activation.

The zygotic genome activation (ZGA) is crucial for the development of pre-implantation embryos. Long noncoding RNAs (lncRNAs) play significant roles in many biological processes, but the study on their role in the early embryonic development of pigs is limited. In this study, we identify lncFKBPL as an enhancer-type lncRNA essential for pig embryo development. lncFKBPL is expressed from the 4-cell stage to the morula stage in pig embryos, and interference with lncFKBPL leads to a developmental arrest at the 8-cell stage. Mechanistic investigations uncover that lncFKBPL is able to bind to MED8, thereby mediating enhancer activity and regulating FKBPL expression. Additionally, FKBPL interacts with the molecular chaperone protein HSP90AA1, stabilizing CDK9 and boosting its protein-level expression. Elevated CDK9 levels enhance Pol II phosphorylation, facilitating ZGA. Our findings illuminate the role of lncFKBPL as an enhancer lncRNA in pig ZGA regulation and early embryo development, providing a foundation for further exploration in this area.

Animals

Hormonal control of gene expression: differential activation of rat bone marrow RNA polymerases by erythropoietin and testosterone.

Hormones play a role in the regulation of gene expression by inducing changes in enzyme patterns in target cells mediated by the synthesis of specific RNA molecules. Erythropoiesis has been used as a system for studying the molecular mechanism of regulation of gene action by means of two hormones: erythropoietin and testosterone. Experiments designed to correlate the biochemical action of both hormones on rat marrow cells are herein reported. Both factors seems to act at different biochemical and citological levels. Erythropoietin triggers the erythropoietic process acting on the erythropoietin sensitive cells (ESC), in which the hormone induces the synthesis of a high molecular weight RNA, which is the precursor of a functional 9 S messenger RNA. Testosterone seems to act on polychromatophilic erythroblasts, in which the synthesis of ribosomal RNA or its precursor is stimulated. The steroid enhances the nuclear ribonuclease activity, which could represent a control mechanism for the processing (maturation) of high molecular weight RNAs. The incorporation of 3H-GTP and 3H-UTP into RNA by isolated rat bone marrow nuclei is stimulated by erythropoietin and testosterone. Using alpha-amanitine and different ionic strength conditions it was found that erythropoietin enhances preferentially RNA polymerase II activity while testosterone increases RNA polymerase I activity. It is postulated that erythropoietin and testosterone act synergically to create the biochemical machinery for hemoglobin synthesis, the macromolecule that characterizes the erythropoietic process.

Amanitins

Are cytotoxicity and interferon inducing activity of poly(I).poly(C) invariably linked in interferon-treated L cells.

Interferon-treated L cells exhibit a specific enhanced susceptibility to the cytotoxic and interferon inducing activities of double-stranded RNAs such as poly(1). poly(C). These activities remained closely linked through widely varying assay conditions, involving, for example, different time anddosage schedules of poly(1). poly (C),suggesting that there is at least one common step in the mechanisms leading to interferon formation and toxicity in interferon-primed cells exposed to poly(1).poly(C). However, some procedures such as addition of metabolic inhibitors (actinomycin D, cycloheximide) and repeated administration of poly(1).poly(C) suppressed the interferon inducing capacity of poly(1).poly(C) without a concomitant decrease of toxicity. Other procedures such as brief treatment of the cells with interferon or DEAE-dextran permitted full expression of the interferon inducing activity of poly(1).poly(C) without any sign of toxicity. The latter results suggest that the mechanisms underlying interferon production and toxicity of poly(1).poly(C) in interferon-treated L cells diverge from a certain point onward.

Animals

m6A RNA methylation modulates IFN-γ-stimulated intestinal epithelial cell-intrinsic antiparasitic defense.

N6-methyladenosine (m6A) RNA methylation is one of the most prevalent reversible post-transcriptional RNA modifications and has been recognized as a crucial regulator of host immune responses. Intestinal epithelial cells (IECs) constitute an important component of gastrointestinal mucosal immunity. Interferons (IFNs) play a central role in maintaining intestinal homeostasis, and m6A methylation status influences IFN-mediated cell-intrinsic defense. In this study, we investigated the potential role of m6A RNA modifications in IFN-γ-stimulated IEC-intrinsic defense. We observed significant alterations in the topology of the m6A mRNA methylome in murine IECs following IFN-γ stimulation. A subset of IFN-γ-stimulated immune gene transcripts exhibited increased m6A RNA methylation, including several members of the immunity-related GTPase family M (IRGM) genes. In addition, IFN-γ-responsive long non-coding RNAs may modulate the m6A methylation levels of multiple IFN-γ-stimulated immune transcripts. Enhanced m6A methylation of the Irgm2/3 transcripts was associated with strengthened cell-intrinsic defense against infection by the protozoan parasite Cryptosporidium. Notably, Cryptosporidium infection altered the host m6A mRNA methylome in IECs, thereby counteracting the IFN-γ-mediated defense response. Although the RNA levels of Irgm2/3 genes were upregulated, their m6A RNA methylation levels and protein expression were reduced in infected cells. This effect was associated with host delivery of dsRNAs derived from Cryptosporidium parvum virus 1, a virus harbored in the parasite. Collectively, our findings suggest that m6A methylation of RNA transcripts enhances IFN-γ-mediated IEC-intrinsic antiparasitic defense, while Cryptosporidium has evolved mechanisms to evade this response by suppressing m6A RNA methylation of IFN-γ-stimulated immune genes.

Animals

abCRISPR: deep learning-based design of abasic gRNA sequences for specific CRISPR-Cas9 genome editing.

SUMMARY: CRISPR-Cas9 has become a widely used tool for genome editing. However, its off-target cleavage caused by partial sequence matches with guide RNAs (gRNAs) remains a critical limitation. Recently, abasic gRNAs (ØXØ) have been developed to enhance target specificity, but their effects vary depending on the positional sequence context. Here, we present abCRISPR, a deep neural network (DNN) framework for the rational design of ØXØ sequences with minimized off-target activity. abCRISPR leverages informative few-shot training with paired datasets of abasic and unmodified gRNAs, using high-quality random mismatch target libraries, exhaustively sequenced for mismatched off-target substrates (n = 97583) in in vitro CRISPR-Cas9 cleavage experiments. Predicted off-target activities for both abasic and unmodified gRNAs showed strong correlation with experimental data (r ≥ 0.95, 10-fold cross-validation). Notably, these comprehensive training sets provide robust ground-truth negatives, enabling accurate and sensitive prediction of off-targets. For unmodified gRNAs, abCRISPR (AUC = 0.98) was validated to outperform existing deep learning-based methods (AUC = 0.45-0.68). When applied to the human genome, abCRISPR generated ØXØ sequences, covering 58 875 004 potent CRISPR-targetable sites with improved target specificity. Together, this work provides a comprehensive bioinformatics resource for safe and precise CRISPR-Cas9 genome editing. AVAILABILITY AND IMPLEMENTATION: The source code for abCRISPR and training data are available at https://doi.org/10.5281/zenodo.20398246. abCRISPR results for the human genome are available at http://clip.korea.ac.kr/abCRISPR/.

Deep Learning

Review: ethidium fluorescence assay. Part II. Enzymatic studies and DNA-protein interactions.

Almost all DNA and RNA metabolizing enzymes can be assayed rapidly and very sensitively by exploiting the enhanced fluorescence of ethidium intercalated into duplex DNA or RNA. Denatured DNA and natural RNAs contain duplex regions due to intramolecular hydrogen-bonding and can also be sensitively measured. Where the product is truly single-stranded (e.g. dTn) it can be assayed by adding the appropriate complementary strand (e.g. dAn or rAn). Some of the assays described provide information not readily obtained by other assay procedures. Among the enzymes readily assayed are DNA and RNA polymerases, terminal deoxynucleotidyl transferases, nucleases of all varieties (e.g. single-strand specific, endonucleases including for example AP endonucleases, exonucleases, RNase H, etc.), ligases, topoisomerases including gyrases, and indirectly enzymes such as proteases and superoxide dismutase. DNA binding proteins such as histones and helix destablizing proteins can also be quantitatively assayed.

DNA

Transfection-mediated recombination of influenza A virus.

Several mechanisms, including a high mutation rate and reassortment of genes, have been found to be responsible for the variability of influenza A viruses. RNA recombination would be another mechanism leading to genetic variation; however, recombination has only rarely been reported to occur in influenza viruses. During ribonucleoprotein transfection experiments designed to generate viable influenza viruses from in vitro-synthesized RNA, we discovered several viruses which must have originated from recombination events. The ribonucleoprotein transfection system may enhance the formation of viruses which result from jumping of the viral polymerase between RNAs or from ligation of different viral RNAs. Five different recombinant viruses are described. Two of these, REC1 and REC2, contain a neuraminidase (NA) gene whose defective polyadenylation signal has been repaired via intergenic recombination; 124 and 95 nucleotides have been added, respectively. Another virus, REC5, must have originated by multiple recombination events since it contains a mosaic gene with sequences derived from the NA gene of influenza A/WSN/33 virus and the matrix, polymerase protein PB1, and NA genes of influenza A/PR/8/34 virus.

Animals

Long noncoding RNA GAS5 disrupts intestinal epithelial barrier function by increasing small vault RNA levels.

Disruptions in the integrity of the intestinal epithelium occur commonly in inflammatory bowel disease (IBD) and critical surgical disorders, but the underlying mechanisms remain largely unknown. Here we identified long noncoding RNA GAS5 as a repressor of intestinal mucosal growth and the function of the gut epithelial barrier. The levels of tissue GAS5/Gas5 increased in mouse intestinal mucosa after colitis and septic stress, as well as in human intestinal mucosa from patients with IBD. Transient and tissue-specific knockdown of Gas5 in mice using CRISPR/Cas9 enhanced the renewal of the mucosa of the small intestine, increased the levels of tight junction (TJ) proteins ZO-1, ZO-2, claudin-1, and claudin-2, and improved gut barrier function. Conversely, ectopic overexpression of GAS5 in intestinal organoids and in cultured intestinal epithelium cells decreased the levels of these TJ proteins and caused epithelial barrier dysfunction. Mechanistic studies revealed that GAS5 acted as a transcriptional enhancer of the gene (2. AUTHOR: Do you mean "genes"?) encoding small noncoding vault RNAs (vtRNAs) and that GAS5 repressed TJ expression by increasing the levels of vtRNAs. Together, our results indicate that GAS5 disrupts the integrity of the intestinal epithelium by impairing mucosal growth and epithelial barrier function and that it represses TJ expression, at least in part, via vtRNAs.

Animals

Dual-gRNA CRISPR/Cas9 Deletion of CsDMR6 in Sweet Orange Supported by Improved In Vitro Regeneration.

Huanglongbing (HLB), caused by Candidatus Liberibacter spp., remains the most destructive disease affecting citrus worldwide. To support host-directed genome-editing strategies aimed at reducing susceptibility, we optimized key regeneration steps in Citrus sinensis and validated a dual-gRNA CRISPR/Cas9 approach targeting the susceptibility gene CsDMR6. Juvenile explants of 'Valencia' and hybrid genotypes (CsH1-CsH3) were successfully established in vitro, and shoot elongation was markedly improved by supplementing Citrus Shoot Multiplication (CiSM) medium with 1 mg L-1 GA3. Callus induction was most efficient in Citrus Callus Induction (CiCM) medium under dark conditions, while a 48 h NAA pulse (100 µM) significantly enhanced rooting, increasing efficiencies to 37.1% in 'Valencia' and 52.9% in CsH1. Two guide RNAs targeting conserved regions of CsDMR6 were designed and shown to be identical across all evaluated genotypes. The dual-gRNA cassette was assembled into a CRISPR/Cas9 geminivirus-based vector and transiently delivered into sweet orange leaf tissue via Agrobacterium. GFP fluorescence verified construct expression, and PCR amplification across the target region produced a diagnostic ~447 bp fragment corresponding to the expected ~5.8 kb deletion. Sanger sequencing confirmed precise junction formation between the two cut sites. These results demonstrate efficient large-fragment deletion of CsDMR6 in sweet orange and establish an experimentally validated, genotype-compatible regeneration and editing platform. This study provides a transient validation of the dual-gRNA system and establishes the technical foundation required for future stable, non-transgenic edited lines. Together, these advances support the downstream functional evaluation of CsDMR6 loss-of-function alleles under HLB pressure.

CRISPR/Cas9

Enhanced exonuclease-Cas9 systems promote multiple nucleotide deletions with higher efficiency and broader targeting scope in plants.

CRISPR-Cas9 is a widely used platform for plant genome editing, but its outcomes are typically dominated by small insertions and deletions (indels). Such limited mutation profiles restrict its utility in functional studies of non-coding RNAs and regulatory elements, such as microRNAs (miRNAs), untranslated regions (UTRs), and promoter sequences, where larger sequence disruptions are often required. Here, we developed enhanced exonuclease-Cas9 platforms, termed multiple nucleotide deletion Cas9 (MND-Cas9) systems, for efficient generation of large deletions in rice. By screening four exonucleases (RecJ, T5, TREX2, and SbcB), we established MND-Cas9v1 systems based on TREX2 or SbcB that produced substantially larger deletions without reducing editing efficiency. Further optimization with an inserted DNA-binding domain (DBD) between Cas9 and exonuclease yielded MND-Cas9v2, which simultaneously enhanced efficiency and deletion size. To expand PAM compatibility, we introduced PAM-relaxed Cas9-NG and SpG variants, generating MND-Cas9-NG/SpGv2 systems with broader targeting scope and superior performance compared to their parental nucleases. Finally, we demonstrated the utility of these systems in two applications: MND-Cas9v2 efficiently knocked out the miRNA gene OsMIR530, producing larger seeds, and generated extended deletions in the 3'UTR of OsGhd2, which upregulated its expression and increased grain size. These results demonstrate that MND-Cas9 systems enable high-efficiency generation of extended deletions and facilitate functional analyses of non-coding RNAs and regulatory sequences. Overall, this work establishes a versatile and expandable exonuclease-Cas9 platform that substantially broadens the mutational spectrum and application potential of CRISPR-Cas9 for plant genome engineering.

CRISPR-Cas Systems

Global lncRNA expression profiles in medulloblastoma reveal crucial lncRNA-oncogene interactions in Sonic hedgehog and Group 4.

BACKGROUND: Advances in multi-omic studies have improved medulloblastoma (MB) characterization, yet novel molecular biomarkers are needed to refine tumor biology and therapeutic strategies. Current profiling mainly targets the protein-coding genome, while the potential of noncoding regions remains unexplored. This study aims to identify long noncoding RNAs (lncRNAs), emerging as crucial regulators in MB, as potential key biomarkers specific to molecular group, enhancing understanding of MB's genomic landscape. METHODS: RNA-seq data from 54 Spanish MB patients (C1) and 207 public samples (C2) were analyzed to profile lncRNAs. Expression and Weighted Gene Coexpression Network (WGCNA) analyses were performed to identify lncRNA-oncogene interactions. Group-specific interactions were examined to infer their role in MB pathogenesis and highlight potential lncRNA involvement in disease mechanisms. RESULTS: LncRNA expression profiles identified 4 clusters corresponding to the MB molecular groups, confirming their potential as biomarkers. Expression and WGCNA analyses revealed group-specific lncRNAs for Sonic hedgehog (SHH), Group 3 (Gr3), and Group 4 (Gr4) MB. Lnc-SMARCA2 was exclusively upregulated in SHH MB, and associated with ATOH1 and PDLIM3, key cilium regulators of this group's cell of origin. In Gr4 MB, MGC32805 and LOC107986446 were upregulated and linked to SNCAIP, potentially influencing PRDM6 activation via enhancer hijacking. Additionally, a 5-lncRNA signature linked to phototransduction was exclusive to Gr3, offering insights into its lineage switch and molecular regulation. CONCLUSIONS: Lnc-SMARCA2 and, MGC32805 and LOC107986446, are exclusively deregulated in SHH and Gr4 MB, respectively, and directly associated with group-specific MB oncogenes, representing promising novel biomarkers and therapeutic targets in MB.

cancer biomarkers

Transcription of host-substituted simian virus 40 DNA in whole cells and extracts.

Viral transcriptional complexes were extracted from the nuclei of monkey kidney cells infected with wild-type simian virus 40 (SV40) or a variant strain containing a high proportion of host-substituted DNA molecules. The RNAs synthesized by these complexes in an in vitro system were analyzed for their content of SV40 and host sequences by a technique of sequential hybridization to plaque-purified and substituted viral DNAs. The relative labeling of the two types of sequences was commensurate with their proportion in the viral DNA (about 20% host). The substituted virus contains both reiterated and unique types of cellular sequences, and both kinds appeared to be transcribed. Transcripts of the substituted sequences formed a much smaller proportion of the virus related RNA recovered from intact infected cells, suggesting that host sequence transcripts are synthesized but rapidly degraded in the whole cell. The alternative, that transcription of these sequences is artificially enhanced in the in vitro system, cannot be rigorously excluded. We compared the self-annealing of viral RNAs from nuclear extracts of cells infected with wild-type and substituted viruses; transcripts labeled both in vivo and in vitro showed a two- to threefold-higher level of self-annealing in the case of the variant than in the case of wild type SV40.

Base Sequence

Multiplexed perturbation enables scalable pooled screens.

CRISPR-based genetic perturbation screens have revolutionized the ability to link genes to cellular phenotypes with unprecedented precision and scale; however, conventional pooled CRISPR screens require large cell numbers to achieve adequate sgRNA representation, posing technical and financial challenges. Here, we investigate the impact of co-delivery of multiple guide RNAs via high multiplicity of infection (MOI) in pooled CRISPR interference screens as a strategy to enhance screening efficiency while reducing cell numbers. We systematically evaluate screen performance across varying MOIs, assessing the effects of multiplexing on knockdown efficiency, sgRNA representation and potential interference of multiple sgRNA phenotypes. Our data demonstrate that sgRNA multiplexing (MOI 2.5-10) can maintain screen performance while enabling significant reductions in cell number requirements. We further apply these optimized conditions to conduct a genome-wide CRISPR screen for regulators of the intracellular adhesion molecule ICAM-1, successfully identifying new candidates using as few as half a million cells. This study provides a framework for adopting multiplexed sgRNA strategies to streamline CRISPR screening applications in resource-limited settings.

Humans

The effect of inhibitors of cellular RNA synthesis on stimulation of mouse encephalomyocarditis virus reproduction by poliovirus in HeLa and MIO cells.

Inoculation of HeLa and MIO cells with a guanidine-dependent mutant of poliovirus (gd-polio) in the absence of guanidine resulted in stimulation of mouse encephalomyocarditis (EMC) virus reproduction. No stimulation was found to occur in the presence of actinomycin D, on pre-treatment of the cells with cordycepin, or on their UV irradiation or enucleation. In contrast to HeLa cells, the enhancement of EMC virus reproduction by gd-polio in MIO cells required no current synthesis of cellular RNAs: it occurred in the presence of actinomycin D, upon UV irradiation of the cells or their enucleation. The possible mechanisms of the stimulating effect of poliovirus in HeLa and MIO cells are discussed.

Animals

[Enhancer-of-white-apricot and its effects on the copia insertion allele white-apricot in Drosophila melanogaster].

In Drosophila melanogaster, the w(a) allele differs from the red-eye gene (w+) by the insertion of the retrovirus-like transposable element copia within the transcription unit. The w(a) flies have the apricot eye color. Most RNAs derived from w(a) have 3' termini within the 3' LTR of copia, and only small amounts of structurally normal RNA are produced. The eye color of flies with w(a) is affected by the gene Enhancer-of-white-apricot [E(w(a))] and become lighter. This effect on pigmentation is correlated with a corresponding decrease in white RNA having wild-type structure which was determined by the Northern blot. Three revertant alleles of E(w(a)) was generated by the irradiation with gamma-ray. These alleles are recessive lethals with death occurring during the larval stage. The original E(w(a)) allele is an antimorph and produces a product that interferes with the activity of the wild-type gene which have the product expected to either have a positive role in the splicing of w(a) RNAs or a negative role in polyadenylation.

Alleles

Interferon action II. Membrane-bound alkaline ribonuclease activity in chick embryo cells manifesting interferon-mediated interference.

Membrane fractions from chick embryo cells manifesting viral interference mediated by interferon or poly(I)-poly(C) contain high levels of an alkaline ribonuclease. Enhanced RNase activity is not observed when inhibitors of cell protein or RNA synthesis are present during interferon treatment, or when heterologous interferon is used. The RNase associated with comparable membrane fractions from cells treated with mock-interferon is about 1/10 as active, and shows qualitative differences. In principle, divergent views of interferon action may be reconciled to a common mode of action by postulating that viral interference results from a newly induced or activated RNase of cellular origin and proper specificity that acts to reduce the accumulation and functional capacity of newly synthesized viral RNAs, particularly mRNA. Previous data in support of interferon's acting to inhibit virion-derived transcription in vivo are now interpreted as demonstrating enhanced degradation of viral transcripts (mRNA).

Animals

UFold-X: an enhanced Dual & Dynamic U-Mamba model for long-range RNA secondary structure prediction.

RNA secondary structure is essential for understanding the functions of non-coding RNAs, ribosomal RNAs, and viral genomes. However, accurate prediction of long RNA structures remains challenging due to complex long-range interactions and the limited availability of long-RNA training data. We present UFold-X, a dual-branch deep learning framework that combines a convolutional encoder for local structure modeling with a Mamba-based Visual State Space Module for capturing long-range dependencies. A dynamic gating mechanism adaptively integrates the two branches according to sequence length. UFold-X was evaluated on multiple benchmark datasets containing RNAs up to 5000 nucleotides. To rigorously assess generalization, we introduced a cross-clan benchmark for long RNAs. Under this stringent setting, UFold-X achieved performance comparable to state-of-the-art classical approaches while achieving the best performance among deep learning-based methods. Additional cross-family and within-family evaluations further demonstrated robust transferability and competitive predictive performance. UFold-X also maintained excellent computational efficiency, requiring only 0.08 s per sequence on average. To assess biological consistency, we developed a SHAPE-based reactivity prediction variant (UFold-X-R) and an integrated metric, the Hybrid Reactivity-Pairing Score (HRPS). UFold-X-R showed strong agreement with experimental icSHAPE data and achieved the highest HRPS among all evaluated methods. A user-friendly web server is available at https://ufold-x.ai4bread.com.

Nucleic Acid Conformation

Increased production of human immunodeficiency virus (HIV) in HIV-induced syncytia formation: an efficient infection process.

Syncytia or multinucleated giant-cell formation is one of the major cytopathic effects induced by human immunodeficiency virus (HIV) infection. Cell fusion results from the strong interaction of CD4 molecules on the surface of the uninfected T cells and gp120, an external envelope glycoprotein of HIV on the infected T cells. We studied the production of HIV in fusion cells between MOLT-4 and virus-infected MOLT-4/HIV cells and found that HIV production was enhanced up to three- to fivefold, which showed a good correlation with the appearance and extent of syncytia formation. Blocking the fusion by monoclonal antibody against a binding epitope of CD4 molecule to gp120 decreased the HIV production significantly. Enhancement of HIV production was observed by more than five-fold in comparison with chronically infected cells, which were fusion free 20 hr postcocultivation. Electron microscopic observation also showed the presence of abundant HIV particles inside the fused cells and on the outer surface. AZT blocked the HIV augmentation of fused cells in coculture completely. Southern blot analysis revealed that both integrated and unintegrated HIV DNA were highly accumulated in fusion cells, as compared with fusion-free MOLT-4/HIV cells. Among unintegrated DNA, circular and linear DNA were accumulated to a similar degree. Northern blot hybridization showed that rapid enhancement of all three species of HIV-specific RNA containing genomic (9.2 kb) and subgenomic (4.3 and 1.9 kb) RNAs were found 20 hr postinfection in fusion cells. These data suggest that syncytia formation is an extremely active infection process of HIV, by which multiple rounds of reinfection might take place.

Animals