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- MicroRNAs (9)
- Caenorhabditis elegans (6)
- MicroRNA (3)
- Caenorhabditis elegans Proteins (2)
- Gene Expression Regulation, Developmental (2)
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- Mutation (2)
- *Gene Expression Regulation, Developmental (1)
- *Immunity, Innate (1)
- ALG-1 (1)
- Alleles (1)
- Argonaute (1)
- Biosynthesis (1)
- Carrier Proteins (1)
- Dauer (1)
- Development (1)
- Developmental timing (1)
- Distal tip cell migrations (1)
- Drosophila (1)
- Fertility (1)
- Gene Expression Regulation (1)
- Gene Regulatory Networks (1)
- Genes, Reporter (1)
- Germline (1)
- Heterochronic developmental timing (1)
- Immune System (1)
- Immunoprecipitation (1)
- Innate immunity (1)
- Larvae (1)
- Let-7 (1)
- Let-7 family microRNAs (1)
Articles 1 - 15 of 15
Full-Text Articles in Life Sciences
Caenorhabditis Elegans Alg-1 Antimorphic Mutations Uncover Functions For Argonaute In Microrna Guide Strand Selection And Passenger Strand Disposal, Anna Y. Zinovyeva, Isana Veksler-Lublinsky, Ajay A. Vashisht, James A. Wohlschlegel, Victor R. Ambros
Caenorhabditis Elegans Alg-1 Antimorphic Mutations Uncover Functions For Argonaute In Microrna Guide Strand Selection And Passenger Strand Disposal, Anna Y. Zinovyeva, Isana Veksler-Lublinsky, Ajay A. Vashisht, James A. Wohlschlegel, Victor R. Ambros
Victor R. Ambros
MicroRNAs are regulators of gene expression whose functions are critical for normal development and physiology. We have previously characterized mutations in a Caenorhabditis elegans microRNA-specific Argonaute ALG-1 (Argonaute-like gene) that are antimorphic [alg-1(anti)]. alg-1(anti) mutants have dramatically stronger microRNA-related phenotypes than animals with a complete loss of ALG-1. ALG-1(anti) miRISC (microRNA induced silencing complex) fails to undergo a functional transition from microRNA processing to target repression. To better understand this transition, we characterized the small RNA and protein populations associated with ALG-1(anti) complexes in vivo. We extensively characterized proteins associated with wild-type and mutant ALG-1 and found that the mutant …
Robust Distal Tip Cell Pathfinding In The Face Of Temperature Stress Is Ensured By Two Conserved Micrornas In Caenorhabditis Elegans, Samantha L. Burke, Molly Hammell, Victor R. Ambros
Robust Distal Tip Cell Pathfinding In The Face Of Temperature Stress Is Ensured By Two Conserved Micrornas In Caenorhabditis Elegans, Samantha L. Burke, Molly Hammell, Victor R. Ambros
Victor R. Ambros
Biological robustness, the ability of an organism to maintain a steady-state output as genetic or environmental inputs change, is critical for proper development. MicroRNAs have been implicated in biological robustness mechanisms through their post-transcriptional regulation of genes and gene networks. Previous research has illustrated examples of microRNAs promoting robustness as part of feedback loops and genetic switches and by buffering noisy gene expression resulting from environmental and/or internal changes. Here we show that the evolutionarily conserved microRNAs mir-34 and mir-83 (homolog of mammalian mir-29) contribute to the robust migration pattern of the distal tip cells in Caenorhabditis elegans by specifically …
Biodistribution And Function Of Extracellular Mirna-155 In Mice, Shashi Bala, Timea Csak, Fatemeh Momen-Heravi, Dora Lippai, Karen Kodys, Donna Catalano, Abhishek Satishchandran, Victor R. Ambros, Gyongyi Szabo
Biodistribution And Function Of Extracellular Mirna-155 In Mice, Shashi Bala, Timea Csak, Fatemeh Momen-Heravi, Dora Lippai, Karen Kodys, Donna Catalano, Abhishek Satishchandran, Victor R. Ambros, Gyongyi Szabo
Victor R. Ambros
Circulating miRNAs can be found in extracellular vesicles (EV) and could be involved in intercellular communication. Here, we report the biodistribution of EV associated miR-155 using miR-155 KO mouse model. Administration of exosomes loaded with synthetic miR-155 mimic into miR-155 KO mice resulted in a rapid accumulation and clearance of miR-155 in the plasma with subsequent distribution in the liver, adipose tissue, lung, muscle and kidney (highest to lowest, respectively). miR-155 expression was detected in isolated hepatocytes and liver mononuclear cells of recipient KO mice suggesting its cellular uptake. In vitro, exosome-mediated restoration of miR-155 in Kupffer cells from miR-155 …
Inhibiting Mirna In Caenorhabditis Elegans Using A Potent And Selective Antisense Reagent, Genhua Zheng, Victor R. Ambros, Wen-Hong Li
Inhibiting Mirna In Caenorhabditis Elegans Using A Potent And Selective Antisense Reagent, Genhua Zheng, Victor R. Ambros, Wen-Hong Li
Victor R. Ambros
BACKGROUND: Antisense reagents can serve as efficient and versatile tools for studying gene function by inhibiting nucleic acids in vivo. Antisense reagents have particular utility for the experimental manipulation of the activity of microRNAs (miRNAs), which are involved in the regulation of diverse developmental and physiological pathways in animals. Even in traditional genetic systems, such as the nematode Caenorhabditis elegans, antisense reagents can provide experimental strategies complementary to mutational approaches. Presently no antisense reagents are available for inhibiting miRNAs in the nematode C. elegans. RESULTS: We have developed a new class of fluorescently labelled antisense reagents to inhibit miRNAs in …
Victor Ambros: The Broad Scope Of Micrornas. Interview By Caitlin Sedwick, Victor R. Ambros
Victor Ambros: The Broad Scope Of Micrornas. Interview By Caitlin Sedwick, Victor R. Ambros
Victor R. Ambros
Interview with Victor Ambros, who studies how microRNAs impact development.
Mutations In Conserved Residues Of The C. Elegans Microrna Argonaute Alg-1 Identify Separable Functions In Alg-1 Mirisc Loading And Target Repression, Anna Y. Zinovyeva, Samir Bouasker, Martin J. Simard, Christopher M. Hammell, Victor R. Ambros
Mutations In Conserved Residues Of The C. Elegans Microrna Argonaute Alg-1 Identify Separable Functions In Alg-1 Mirisc Loading And Target Repression, Anna Y. Zinovyeva, Samir Bouasker, Martin J. Simard, Christopher M. Hammell, Victor R. Ambros
Victor R. Ambros
microRNAs function in diverse developmental and physiological processes by regulating target gene expression at the post-transcriptional level. ALG-1 is one of two Caenorhabditis elegans Argonautes (ALG-1 and ALG-2) that together are essential for microRNA biogenesis and function. Here, we report the identification of novel antimorphic (anti) alleles of ALG-1 as suppressors of lin-28(lf) precocious developmental phenotypes. The alg-1(anti) mutations broadly impair the function of many microRNAs and cause dosage-dependent phenotypes that are more severe than the complete loss of ALG-1. ALG-1(anti) mutant proteins are competent for promoting Dicer cleavage of microRNA precursors and for associating with and stabilizing microRNAs. However, …
Plasma Micrornas Are Associated With Atrial Fibrillation (The Mirhythm Study) And Change After Catheter-Ablation, David D. Mcmanus, Kahraman Tanriverdi, Honghuang Lin, Nada Esa, Menhel Kinno, Rosalind Lee, Divakar Mandapati, Stanley Tam, Patrick T. Ellinor, John F. Keaney, Emelia J. Benjamin, Victor R. Ambros, Jane E. Freedman
Plasma Micrornas Are Associated With Atrial Fibrillation (The Mirhythm Study) And Change After Catheter-Ablation, David D. Mcmanus, Kahraman Tanriverdi, Honghuang Lin, Nada Esa, Menhel Kinno, Rosalind Lee, Divakar Mandapati, Stanley Tam, Patrick T. Ellinor, John F. Keaney, Emelia J. Benjamin, Victor R. Ambros, Jane E. Freedman
Victor R. Ambros
Background: Atrial fibrillation (AF) is the most common dysrhythmia in the U.S. and Europe. Few biomarkers exist to identify individuals at risk for AF. Cardiac microRNAs (miRNAs) have been implicated in susceptibility to AF and are detectable in the circulation. Nevertheless, data are limited on how circulating levels of miRNAs relate to AF or change over time after catheter- ablation. Methods: In 211 miRhythm participants (112 with paroxysmal or persistent AF; 99 without AF), we quantified plasma expression of 86 miRNAs associated with cardiac remodeling or disease by high-throughput quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR). We used qRT-PCR to examine …
Circulating Micrornas Are Associated With Paroxysmal Or Persistent Atrial Fibrillation, David D. Mcmanus, Jeanine Ward, Amir Y. Shaikh, Khushleen Jaggi, Victor R. Ambros, Jane Freedman, John F. Keaney Jr.
Circulating Micrornas Are Associated With Paroxysmal Or Persistent Atrial Fibrillation, David D. Mcmanus, Jeanine Ward, Amir Y. Shaikh, Khushleen Jaggi, Victor R. Ambros, Jane Freedman, John F. Keaney Jr.
Victor R. Ambros
Introduction: Novel methods of identifying individuals at risk for atrial fibrillation (AF) are needed. MicroRNAs (MiRNAs) regulate gene expression in a number of cardiovascular diseases, including AF. It is unknown, however, if key circulating, cardiac-specific miRNAs differ between individuals with paroxysmal or persistent AF and those in sinus rhythm. Methods: 17 individuals with a history of AF were recruited prior to catheter ablation. 24 hospitalized patients in normal sinus rhythm and no history of AF comprised the control group. 94 plasma miRNAs were selected based on a priori associations with processes implicated in AF for evaluation using the TaqMan miRNA …
Circulating Cell And Plasma Microrna Profiles Differ Between Non-St-Segment And St-Segment-Elevation Myocardial Infarction, Jeanine Ward, Nada Esa, Rahul Pidikiti, Jane E. Freedman, John F. Keaney, Kahraman Tanriverdi, Olga Vitseva, Victor R. Ambros, Rosalind Lee, David D. Mcmanus
Circulating Cell And Plasma Microrna Profiles Differ Between Non-St-Segment And St-Segment-Elevation Myocardial Infarction, Jeanine Ward, Nada Esa, Rahul Pidikiti, Jane E. Freedman, John F. Keaney, Kahraman Tanriverdi, Olga Vitseva, Victor R. Ambros, Rosalind Lee, David D. Mcmanus
Victor R. Ambros
BACKGROUND: Differences in plasma and whole blood expression microRNAs (miRNAs) in patients with an acute coronary syndrome (ACS) have been determined in both in vitro and in vivo studies. Although most circulating miRNAs are located in the cellular components of whole blood, little is known about the miRNA profiles of whole blood subcomponents, including plasma, platelets and leukocytes in patients with myocardial ischemia. METHODS: Thirteen patients with a ST-segment-elevation (STEMI) or non-ST-segment elevation (NSTEMI) myocardial infarction were identified in the University of Massachusetts Medical Center Emergency Department (ED) or cardiac catheterization laboratory between February and June of 2012. Whole blood …
The Embryonic Mir-35 Family Of Micrornas Promotes Multiple Aspects Of Fecundity In Caenorhabditis Elegans, Katherine Mcjunkin, Victor R. Ambros
The Embryonic Mir-35 Family Of Micrornas Promotes Multiple Aspects Of Fecundity In Caenorhabditis Elegans, Katherine Mcjunkin, Victor R. Ambros
Victor R. Ambros
MicroRNAs guide many aspects of development in all metazoan species. Frequently, microRNAs are expressed during a specific developmental stage to perform a temporally defined function. The C. elegans mir-35-42 microRNAs are expressed abundantly in oocytes and early embryos and are essential for embryonic development. Here, we show that these embryonic microRNAs surprisingly also function to control the number of progeny produced by adult hermaphrodites. Using a temperature-sensitive mir-35-42 family mutant (a deletion of the mir-35-41 cluster), we demonstrate three distinct defects in hermaphrodite fecundity. At permissive temperatures, a mild sperm defect partially reduces hermaphrodite fecundity. At restrictive temperatures, somatic gonad …
An Efficient And Sensitive Method For Preparing Cdna Libraries From Scarce Biological Samples, Catherine H. Sterling, Isana Veksler-Lublinsky, Victor R. Ambros
An Efficient And Sensitive Method For Preparing Cdna Libraries From Scarce Biological Samples, Catherine H. Sterling, Isana Veksler-Lublinsky, Victor R. Ambros
Victor R. Ambros
The preparation and high-throughput sequencing of cDNA libraries from samples of small RNA is a powerful tool to quantify known small RNAs (such as microRNAs) and to discover novel RNA species. Interest in identifying the small RNA repertoire present in tissues and in biofluids has grown substantially with the findings that small RNAs can serve as indicators of biological conditions and disease states. Here we describe a novel and straightforward method to clone cDNA libraries from small quantities of input RNA. This method permits the generation of cDNA libraries from sub-picogram quantities of RNA robustly, efficiently and reproducibly. We demonstrate …
Caenorhabditis Elegans Micrornas Of The Let-7 Family Act In Innate Immune Response Circuits And Confer Robust Developmental Timing Against Pathogen Stress, Zhiji Ren, Victor R. Ambros
Caenorhabditis Elegans Micrornas Of The Let-7 Family Act In Innate Immune Response Circuits And Confer Robust Developmental Timing Against Pathogen Stress, Zhiji Ren, Victor R. Ambros
Victor R. Ambros
Animals maintain their developmental robustness against natural stresses through numerous regulatory mechanisms, including the posttranscriptional regulation of gene expression by microRNAs (miRNAs). Caenorhabditis elegans miRNAs of the let-7 family (let-7-Fam) function semiredundantly to confer robust stage specificity of cell fates in the hypodermal seam cell lineages. Here, we show reciprocal regulatory interactions between let-7-Fam miRNAs and the innate immune response pathway in C. elegans. Upon infection of C. elegans larvae with the opportunistic human pathogen Pseudomonas aeruginosa, the developmental timing defects of certain let-7-Fam miRNA mutants are enhanced. This enhancement is mediated by the p38 MAPK innate immune pathway acting …
Drosophila Let-7 Microrna Is Required For Remodeling Of The Neuromusculature During Metamorphosis, Nicholas S. Sokol, Peizhang Xu, Yuh-Nung Jan, Victor R. Ambros
Drosophila Let-7 Microrna Is Required For Remodeling Of The Neuromusculature During Metamorphosis, Nicholas S. Sokol, Peizhang Xu, Yuh-Nung Jan, Victor R. Ambros
Victor R. Ambros
The Drosophila let-7-Complex (let-7-C) is a polycistronic locus encoding three ancient microRNAs: let-7, miR-100, and fly lin-4 (miR-125). We find that the let-7-C locus is principally expressed in the pupal and adult neuromusculature. let-7-C knockout flies appear normal externally but display defects in adult behaviors (e.g., flight, motility, and fertility) as well as clear juvenile features in their neuromusculature. We find that the function of let-7-C to ensure the appropriate remodeling of the abdominal neuromusculature during the larval-to-adult transition is carried out predominantly by let-7 alone. This heterochronic role of let-7 is likely just one of the ways in which …
Effect Of Life History On Microrna Expression During C. Elegans Development, Xantha Karp, Molly Hammell, Maria C. Ow, Victor R. Ambros
Effect Of Life History On Microrna Expression During C. Elegans Development, Xantha Karp, Molly Hammell, Maria C. Ow, Victor R. Ambros
Victor R. Ambros
Animals have evolved mechanisms to ensure the robustness of developmental outcomes to changing environments. MicroRNA expression may contribute to developmental robustness because microRNAs are key post-transcriptional regulators of developmental gene expression and can affect the expression of multiple target genes. Caenorhabditis elegans provides an excellent model to study developmental responses to environmental conditions. In favorable environments, C. elegans larvae develop rapidly and continuously through four larval stages. In contrast, in unfavorable conditions, larval development may be interrupted at either of two diapause stages: The L1 diapause occurs when embryos hatch in the absence of food, and the dauer diapause occurs …
In The Tradition Of Science: An Interview With Victor Ambros, Victor R. Ambros
In The Tradition Of Science: An Interview With Victor Ambros, Victor R. Ambros
Victor R. Ambros
No abstract provided.