Fatality in mice due to oversaturation of cellular microRNA/short hairpin RNA pathways

  title={Fatality in mice due to oversaturation of cellular microRNA/short hairpin RNA pathways},
  author={Dirk Grimm and Konrad L. Streetz and Catherine L. Jopling and Theresa A. Storm and Kusum Lata Pandey and Corrine R. Davis and Patricia L. Marion and Felix H. Salazar and Mark A. Kay},
RNA interference (RNAi) is a universal and evolutionarily conserved phenomenon of post-transcriptional gene silencing by means of sequence-specific mRNA degradation, triggered by small double-stranded RNAs. Because this mechanism can be efficiently induced in vivo by expressing target-complementary short hairpin RNA (shRNA) from non-viral and viral vectors, RNAi is attractive for functional genomics and human therapeutics. Here we systematically investigate the long-term effects of sustained… 

RNAi induced hepatotoxicity results from loss of the first synthesized isoform of miR-122 in mice

This study establishes limits to the microRNA machinery that is available for therapeutic siRNAs and suggests new paradigms for the role of miR-122 in liver homeostasis in mice.

Constitutive expression of short hairpin RNA in vivo triggers buildup of mature hairpin molecules.

Overall, the data suggest constitutive expression of shRNA results in accumulation of mature shRNA molecules, inducing cellular toxicity at late time points, despite the presence of gene silencing.

Lentiviral delivery of short hairpin RNAs.

Therapeutic expression of hairpins targeting Apolipoprotein B100 induces differential changes in murine liver

Embedding siRNA sequences targeting Apolipoprotein B100 in shRNA (shApoB) or miRNA (miA poB) scaffolds resulted in differential processing and efficacy, leading to changes in liver morphology, cellular miRNA and gene expression, indicating that therapeutic expression of shA PoB and miApoBs results in alterations of different lipid metabolism genes despite the same phenotypic effect of plasma cholesterol reduction.

Early lethality of shRNA-transgenic pigs due to saturation of microRNA pathways

The results show that shRNA causes adverse effects in vitro and in vivo and sh RNA-induced disruption of the endogenous miRNA pathway may lead to the early lethality of shRNA-transgenic animals, and the effects of shRNAs on the development of somatic cell nuclear transfer embryos.

shRNAs targeting hepatitis C: effects of sequence and structural features, and comparision with siRNA.

The results indicate that shRNAs, which can be prepared by either transcription or chemical synthesis, may be effective agents for the control of HCV.

Expression of shRNA from a tissue-specific pol II promoter is an effective and safe RNAi therapeutic.

It is concluded that this pol II shRNA expression system combined with a potent delivery vector represents an effective alternative to either U6-based strategies or systems that achieve tissue specificity through the use of additional elements.

miRNA-embedded shRNAs for Lineage-specific BCL11A Knockdown and Hemoglobin F Induction.

It is demonstrated that pol III-driven shRNAs lead to significantly increased knockdown but also increased cytotoxcity in comparison to pol II-driven miRNA adapted shRNA(miR)s in multiple hematopoietic cell lines, suggesting the requirement for optimization of shRNA sequences upon incorporation into a miRNA backbone.

RNA interference and antiviral therapy.

The present review focuses on the recent development in the use of RNAi in the prevention and treatment of viral infections and the mechanisms, strategies, hurdles and prospects of employing RNA i in the pharmaceutical industry.



Overexpression of exportin 5 enhances RNA interference mediated by short hairpin RNAs and microRNAs.

It is demonstrated that overexpressed sh RNAs can saturate the activity of endogenous Exportin 5, a factor required for nuclear export of both shRNAs and pre-miRNAs, and simultaneous overexpression of exportin 5 reverses this effect.

The silent revolution: RNA interference as basic biology, research tool, and therapeutic.

RNAi may provide an important new therapeutic modality for treating infection, cancer, neurodegenerative disease, and other illnesses, although in vivo delivery of small interfering RNAs into cells remains a significant obstacle.

Silencing of microRNAs in vivo with ‘antagomirs’

It is shown that a novel class of chemically engineered oligonucleotides, termed ‘antagomirs’, are efficient and specific silencers of endogenous miRNA levels in mice and may represent a therapeutic strategy for silencing miRNAs in disease.

siRNA-mediated gene silencing in vitro and in vivo

A viral-mediated delivery mechanism that results in specific silencing of targeted genes through expression of small interfering RNA (siRNA) is described, establishing proof of principle by markedly diminishing expression of exogenous and endogenous genes in vitro and in vivo in brain and liver.

Inhibition of hepatitis B virus in mice by RNA interference

It is shown that RNAi can be applied to inhibit production of HBV replicative intermediates in cell culture and in immunocompetent and immunodeficient mice transfected with an HBV plasmid, showing that such an approach could be useful in the treatment of viral diseases.

Modulation of Hepatitis C Virus RNA Abundance by a Liver-Specific MicroRNA

It is shown that the sequestration of miR-122 in liver cells results in marked loss of autonomously replicating hepatitis C viral RNAs, suggesting that miR -122 may present a target for antiviral intervention.

DNA constructs designed to produce short hairpin, interfering RNAs in transgenic mice sometimes show early lethality and an interferon response.

Arylamine N-acetyltransferase genes were targeted for inhibition using short hairpin RNA (shRNA) using two different RNA polymerase III promoters and expression of the targeted genes was variable between animals and was not generally inhibitory.

Cre-lox-regulated conditional RNA interference from transgenes.

The ability to efficiently control shRNA expression by using two lentiviral vectors for conditional, Cre-lox-regulated, RNA interference was shown in cell-based experiments and should facilitate functional genetic analysis in mammals.

Extrachromosomal Recombinant Adeno-Associated Virus Vector Genomes Are Primarily Responsible for Stable Liver Transduction In Vivo

This small fraction of integrated genomes greatly decreases the potential risk of vector-related insertional mutagenesis associated with all integrating vectors but also raises uncertainties as to whether rAAV-mediated hepatic gene expression can persist lifelong after a single vector administration.