scholarly journals Mouse Cytomegalovirus MicroRNAs Dominate the Cellular Small RNA Profile during Lytic Infection and Show Features of Posttranscriptional Regulation

2007 ◽  
Vol 81 (24) ◽  
pp. 13771-13782 ◽  
Author(s):  
Lars Dölken ◽  
Jonathan Perot ◽  
Valérie Cognat ◽  
Abdelmalek Alioua ◽  
Matthias John ◽  
...  

ABSTRACT MicroRNAs (miRNAs) are small, noncoding RNA molecules that regulate gene expression at the posttranscriptional level. Originally identified in a variety of organisms ranging from plants to mammals, miRNAs have recently been identified in several viruses. Viral miRNAs may play a role in modulating both viral and host gene expression. Here, we report on the identification and characterization of 18 viral miRNAs from mouse fibroblasts lytically infected with the murine cytomegalovirus (MCMV). The MCMV miRNAs are expressed at early times of infection and are scattered in small clusters throughout the genome with up to four distinct miRNAs processed from a single transcript. No significant homologies to human CMV-encoded miRNAs were found. Remarkably, as soon as 24 h after infection, MCMV miRNAs constituted about 35% of the total miRNA pool, and at 72 h postinfection, this proportion was increased to more than 60%. However, despite the abundance of viral miRNAs during the early phase of infection, the expression of some MCMV miRNAs appeared to be regulated. Hence, for three miRNAs we observed polyuridylation of their 3′ end, coupled to subsequent degradation. Individual knockout mutants of two of the most abundant MCMV miRNAs, miR-m01-4 and miR-M44-1, or a double knockout mutant of miR-m21-1 and miR-M23-2, incurred no or only a very mild growth deficit in murine embryonic fibroblasts in vitro.

2013 ◽  
Vol 81 (11) ◽  
pp. 4081-4090 ◽  
Author(s):  
Ilona Bibova ◽  
Karolina Skopova ◽  
Jiri Masin ◽  
Ondrej Cerny ◽  
David Hot ◽  
...  

ABSTRACTBordetella pertussisis a Gram-negative pathogen causing the human respiratory disease called pertussis or whooping cough. Here we examined the role of the RNA chaperone Hfq inB. pertussisvirulence. Hfq mediates interactions between small regulatory RNAs and their mRNA targets and thus plays an important role in posttranscriptional regulation of many cellular processes in bacteria, including production of virulence factors. We characterized anhfqdeletion mutant (Δhfq) ofB. pertussis18323 and show that the Δhfqstrain produces decreased amounts of the adenylate cyclase toxin that plays a central role inB. pertussisvirulence. Production of pertussis toxin and filamentous hemagglutinin was affected to a lesser extent.In vitro, the ability of the Δhfqstrain to survive within macrophages was significantly reduced compared to that of the wild-type (wt) strain. The virulence of the Δhfqstrain in the mouse respiratory model of infection was attenuated, with its capacity to colonize mouse lungs being strongly reduced and its 50% lethal dose value being increased by one order of magnitude over that of the wt strain. In mixed-infection experiments, the Δhfqstrain was then clearly outcompeted by the wt strain. This requirement for Hfq suggests involvement of small noncoding RNA regulation inB. pertussisvirulence.


mSystems ◽  
2018 ◽  
Vol 3 (3) ◽  
Author(s):  
Ce Yuan ◽  
Michael B. Burns ◽  
Subbaya Subramanian ◽  
Ran Blekhman

ABSTRACT Although variation in gut microbiome composition has been linked with colorectal cancer (CRC), the factors that mediate the interactions between CRC tumors and the microbiome are poorly understood. MicroRNAs (miRNAs) are known to regulate CRC progression and are associated with patient survival outcomes. In addition, recent studies suggested that host miRNAs can also regulate bacterial growth and influence the composition of the gut microbiome. Here, we investigated the association between miRNA expression and microbiome composition in human CRC tumor and normal tissues. We identified 76 miRNAs as differentially expressed (DE) in tissue from CRC tumors and normal tissue, including the known oncogenic miRNAs miR-182, miR-503, and mir-17~92 cluster. These DE miRNAs were correlated with the relative abundances of several bacterial taxa, including Firmicutes , Bacteroidetes , and Proteobacteria . Bacteria correlated with DE miRNAs were enriched with distinct predicted metabolic categories. Additionally, we found that miRNAs that correlated with CRC-associated bacteria are predicted to regulate targets that are relevant for host-microbiome interactions and highlight a possible role for miRNA-driven glycan production in the recruitment of pathogenic microbial taxa. Our work characterized a global relationship between microbial community composition and miRNA expression in human CRC tissues. IMPORTANCE Recent studies have found an association between colorectal cancer (CRC) and the gut microbiota. One potential mechanism by which the microbiota can influence host physiology is through affecting gene expression in host cells. MicroRNAs (miRNAs) are small noncoding RNA molecules that can regulate gene expression and have important roles in cancer development. Here, we investigated the link between the gut microbiota and the expression of miRNA in CRC. We found that dozens of miRNAs are differentially regulated in CRC tumors and adjacent normal colon and that these miRNAs are correlated with the abundance of microbes in the tumor microenvironment. Moreover, we found that microbes that have been previously associated with CRC are correlated with miRNAs that regulate genes related to interactions with microbes. Notably, these miRNAs likely regulate glycan production, which is important for the recruitment of pathogenic microbial taxa to the tumor. This work provides a first systems-level map of the association between microbes and host miRNAs in the context of CRC and provides targets for further experimental validation and potential interventions.


2013 ◽  
Vol 45 (16) ◽  
pp. 685-696 ◽  
Author(s):  
Attia Fatima ◽  
Dermot G. Morris

microRNAs (miRNAs) are a class of small noncoding RNA that bind to complementary sequences in the untranslated regions of multiple target mRNAs resulting in posttranscriptional regulation of gene expression. The recent discovery and expression-profiling studies of miRNAs in domestic livestock have revealed both their tissue-specific and temporal expression pattern. In addition, breed-dependent expression patterns as well as single nucleotide polymorphisms in either the miRNA or in the target mRNA binding site have revealed associations with traits of economic importance and highlight the potential use of miRNAs in future genomic selection programs.


2021 ◽  
Vol 21 ◽  
Author(s):  
Afsane Bahrami ◽  
Gordon A. Ferns

: MicroRNAs (miRs) is a class of conserved, small, noncoding RNA molecules which modulate gene expression post-transcriptionally. miR-148b is a member of miR-148/152 family generally known to be a tumor suppressor via its affect on different signaling pathways and regulatory genes. Aberrant expression of miR-148b has recently been shown to be responsible for tumorigenesis for several different cancer types. This review discusses the current evidences regarding the involvement of miR-148b expression in human cancers and its potential clinical importance for tumor diagnosis, prognosis, and therapeutics.


2005 ◽  
Vol 289 (5) ◽  
pp. C1240-C1250 ◽  
Author(s):  
Maryvonne Baudouin-Legros ◽  
Alexandre Hinzpeter ◽  
Amandine Jaulmes ◽  
Franck Brouillard ◽  
Bruno Costes ◽  
...  

Expression of the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) gene, which contains the mutations responsible for CF, is regulated by cytokines (TNF-α and IL-1β) in a cell-specific manner. TNF-α decreases CFTR mRNA in human colon cell lines (HT-29), but not in pulmonary cell lines (Calu-3), and IL-1β increases it only in Calu-3 cells. We looked for the cytokine-induced posttranscriptional regulation of CFTR gene expression and studied the modulation of CFTR mRNA stability linked to its 3′ untranslated sequence (3′UTR) in HT-29 and Calu-3 cells. The stability of CFTR mRNA was analyzed by Northern blot after in vitro incubation of total RNAs from CFTR-expressing cells with cytosolic proteins extracted from control or cytokine-treated HT-29 and Calu-3 cells. CFTR mRNA was degraded only by extracts of TNF-α-treated HT-29 cells and not by cytosolic proteins from untreated or IL-1β-treated HT-29 cells. In contrast, extracts of untreated Calu-3 cells enhanced CFTR mRNA degradation, and IL-1β treatment inhibited this; TNF-α had no significant effect. The 3′UTR part of CFTR mRNA was found to be required for this posttranscriptional regulation. The 5′ part of the 3′UTR (the 217 first bases), which contains two AUUUA sequences, was implicated in CFTR mRNA destabilization and the following 136 bases, containing several C-repeats in U-rich environment, in its protection. The proteins, which reacted with the U- and C-repeats of CFTR mRNA 3′UTR, were mainly controlled by stimulation of the p42/p44 and p38 MAP kinase cascades with interaction between these pathways. This posttranscriptional control of gene expression is a common feature of CFTR and many proteins of inflammation.


2010 ◽  
Vol 2010 ◽  
pp. 1-29 ◽  
Author(s):  
Nicoletta Filigheddu ◽  
Ilaria Gregnanin ◽  
Paolo E. Porporato ◽  
Daniela Surico ◽  
Beatrice Perego ◽  
...  

Endometriosis, defined as the presence of endometrial tissue outside the uterus, is a common gynecological disease with poorly understood pathogenesis. MicroRNAs are members of a class of small noncoding RNA molecules that have a critical role in posttranscriptional regulation of gene expression by repression of target mRNAs translation. We assessed differentially expressed microRNAs in ectopic endometrium compared with eutopic endometrium in 3 patients through microarray analysis. We identified 50 microRNAs differentially expressed and the differential expression of five microRNAs was validated by real-time RT-PCR in other 13 patients. We identifiedin silicotheir predicted targets, several of which match the genes that have been identified to be differentially expressed in ectopicversuseutopic endometrium in studies of gene expression. A functional analysis of the predicted targets indicates that several of these are involved in molecular pathways implicated in endometriosis, thus strengthening the hypothesis of the role of microRNAs in this pathology.


2012 ◽  
Vol 07 (01n02) ◽  
pp. 41-70 ◽  
Author(s):  
JASON SHULMAN ◽  
LARS SEEMANN ◽  
GREGG W. ROMAN ◽  
GEMUNU H. GUNARATNE

Networks are used to abstract large, highly-coupled sets of objects. Their analyses have included network classification into a few broad classes and selection of small substructures that perform simple yet common tasks. One issue that has received little attention is how the state of a network can be moved according to a pre-specified set of guidelines. In this paper, we address this question in the context of gene networks. In general, neither the full membership of the gene network associated with a biological process nor the precise form of interactions between nodes is known. What is available, through microarrays or sequencing, are gene expression profiles of an organism or its viable mutants. Our approach relies only on these expression profiles, and not on the availability of an accurate model for the network. The first step is to select a small set of core- or master- nodes, such as transcription factors or microRNAs, that can be used to alter the levels of many of the remaining genes in the network. We ask how the state — or solution — of the gene network changes as the levels of these master nodes are altered externally. The object of our study is, not the network, but the surface of these solutions. We argue that it can be approximated using gene expression profiles of the organism and single manipulation of master node activity. This is done through an "effective model." The effective model as well as error estimates for its predictions can be derived from experimental data. The method is validated using synthetic gene networks that have stationary solutions and those that are periodically driven, e.g., circadian networks. An effective model for the oxygen-deprivation network of E.coli is constructed using previously published gene expression profiles, and used to predict the expression levels in a double knockout mutant. Less that 30% of the predictions lie outside the 5% confidence level. We propose the use of the effective model methodology to compute how Drosophila melanogaster in the normal state can be genetically altered into a pre-defined sleep deprived-like state.


2009 ◽  
Vol 106 (17) ◽  
pp. 7028-7033 ◽  
Author(s):  
Zhe Ji ◽  
Ju Youn Lee ◽  
Zhenhua Pan ◽  
Bingjun Jiang ◽  
Bin Tian

The 3′ untranslated regions (3′ UTRs) of mRNAs containcis-acting elements for posttranscriptional regulation of gene expression. Here, we report that mouse genes tend to express mRNAs with longer 3′ UTRs as embryonic development progresses. This global regulation is controlled by alternative polyadenylation and coordinates with initiation of organogenesis and aspects of embryonic development, including morphogenesis, differentiation, and proliferation. Using myogenesis of C2C12 myoblast cells as a model, we recapitulated this process in vitro and found that 3′ UTR lengthening is likely caused by weakening of mRNA polyadenylation activity. Because alternative 3′ UTR sequences are typically longer and have higher AU content than constitutive ones, our results suggest that lengthening of 3′ UTR can significantly augment posttranscriptional control of gene expression during embryonic development, such as microRNA-mediated regulation.


2012 ◽  
Vol 35 (4) ◽  
pp. 285-295 ◽  
Author(s):  
Yimin Zhu ◽  
Xingyuan Xiao ◽  
Lairong Dong ◽  
Zhiming Liu

MicroRNAs are small noncoding RNA molecules that control expression of target genes. Our previous studies show that let-7a decreased in gastric carcinoma and that up-regulation of let-7a by gene augmentation inhibited gastric carcinoma cell growth bothin vitroandin vivo, whereas it remains largely unclear as to how let-7a affects tumor growth. In this study, proteins associated with the function of let-7a were detected by high throughout screening. The cell line of SGC-7901 stablely overexpressing let-7a was successfully established by gene cloning. Two-dimensional gel electrophoresis (2-DEy was used to separate the total proteins of SGC-7901/let-7a, SGC-7901/EV and SGC-7901, and PDQuest software was applied to analyze 2-DE images. Ten different protein spots were identified by MALDI-TOF-MS, and they may be the proteins associated with let-7a function. The overexpressed proteins included Antioxidant protein 2, Insulin–like growth factor binding protein 2, Protein disulfide isomerase A2, C-1-tetrahydrofolate synthase, Cyclin-dependent kinase inhibitor1 (CDKN1) and Rho–GTPase activating protein 4. The underexpressed proteins consisted of S-phase kinase-associated protein 2 (Spk2), Platelet membrane glycoprotein, Fibronectin and Cks1 protein. Furthermore, the different expression levels of the partial proteins (CDKN1, Spk2 and Fibronectin) were confirmed by western blot analysis. The data suggest that these differential proteins are involved in a novel let-7a signal pathway and these findings provide the basis to investigate the functional mechanisms of let-7a in gastric carcinoma.


2016 ◽  
Vol 62 (2) ◽  
pp. 134-140
Author(s):  
A.V. Smirnova ◽  
V.N. Sukhorukov ◽  
V.P. Karagodin ◽  
A.N. Orekhov

MicroRNAs (miRNAs) are small (~22 nucleotides in length) noncoding RNA sequences regulating gene expression at posttranscriptional level. MicroRNAs bind complementarily to certain mRNA and cause gene silencing. The involvement of miRNAs in the regulation of lipid metabolism, inflammatory response, cell cycle progression and proliferation, oxidative stress, platelet activation, endothelial and vascular smooth muscle cells (VSMC) function, angiogenesis and plaque formation and rapture indicates important roles in the initiation and progression of atherosclerosis. The key role of microRNAs in pathophysiology of cardiovascular diseases (CVDs), including atherosclerosis, was demonstrated in recent studies. Creating antisense oligonucleotides is a novel technique for selective changes in gene expression both in vitro and in vivo. In this review, we draw attention to the role of miRNAs in atherosclerosis progression, using miRNA as the potential biomarkers and targets in the CVDs, as well as possible application of antisense oligonucleotides


Sign in / Sign up

Export Citation Format

Share Document