scholarly journals Expression of short hairpin RNAs using the compact architecture of retroviral microRNA genes

2017 ◽  
Author(s):  
James M. Burke ◽  
Rodney P. Kincaid ◽  
Francesca Aloisio ◽  
Nicole Welch ◽  
Christopher S. Sullivan

AbstractShort hairpin RNAs (shRNAs) are effective in generating stable repression of gene expression. RNA polymerase III (RNAP III) type III promoters (U6 or H1) are typically used to drive shRNA expression. While useful for some knockdown applications, the robust expression of U6/H1-driven shRNAs can induce toxicity and generate heterogeneous small RNAs with undesirable off-target effects. Additionally, the U6 and H1 promoters encompass the majority of the ∼270 base pairs (bp) of vector space required for shRNA expression. This can limit the efficacy and/or number of delivery vector options, particularly when delivery of multiple gene/shRNA combinations is required. Here, we develop a compact shRNA (cshRNA) expression system based on retroviral microRNA (miRNA) gene architecture that uses RNAP III type II promoters. We demonstrate that cshRNAs coded from as little as 100 bps of total coding space can precisely generate small interfering RNAs (siRNAs) that are active in the RNA-induced silencing complex (RISC). We provide an algorithm with a user-friendly interface to design cshRNAs for desired target genes. This cshRNA expression system reduces the coding space required for shRNA expression by greater than two-fold as compared to the U6/H1 promoters, which may facilitate therapeutic RNAi applications where delivery vector space is limiting.

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Kazuya Terasawa ◽  
Kazuharu Shimizu ◽  
Gozoh Tsujimoto

RNA interference (RNAi) is a powerful tool for studying gene function owing to the ease with which it can selectively silence genes of interest, and it has also attracted attention because of its potential for therapeutic applications. Chemically synthesized small interfering RNAs (siRNAs) and DNA vector-based short hairpin RNAs (shRNAs) are now widely used as RNAi triggers. In contrast to expressed shRNAs, the use of synthetic shRNAs is limited. Here we designed shRNAs modeled on a precursor microRNA (pre-miRNA) and evaluated their biological activity. We demonstrated that chemically synthetic pre-miRNA-based shRNAs have more potent RNAi activity than their corresponding siRNAs and found that their antisense strands are more efficiently incorporated into the RNA-induced silencing complex. Although greater off-target effects and interferon responses were induced by shRNAs than by their corresponding siRNAs, these effects could be overcome by simply using a lower concentration or by optimizing and chemically modifying shRNAs similar to synthetic siRNAs. These are challenges for the future.


2015 ◽  
Vol 59 (9) ◽  
pp. 5297-5305 ◽  
Author(s):  
Robert J. Scarborough ◽  
Kelsey L. Adams ◽  
Aïcha Daher ◽  
Anne Gatignol

ABSTRACTWe have previously identified a target site in HIV-1 RNA that was particularly accessible to a ribozyme and a short hairpin RNA (shRNA). To design small interfering RNAs (siRNAs) targeting this site, we evaluated the effects of siRNAs with different lengths on HIV-1 production. The potency and efficacy of these siRNAs were dependent on the length of their intended sense strand with trends for symmetrical and asymmetrical formats that were similar. Although a typical canonical format with a 21-nucleotide (nt) sense strand was effective at inhibiting HIV-1 production, Dicer substrate siRNAs (dsiRNAs) with the longest lengths (27 to 29 nucleotides) were the most effective. Induction of double-stranded RNA immune responses and effects on cell viability were not detected in cells transfected with different siRNAs, suggesting that the differences observed were not related to indirect effects on HIV-1 production. For the corresponding shRNA designs, a different trend in potency and efficacy against HIV-1 production was observed, with the most effective shRNAs having stem lengths from 20 to 27 bp. Our results highlight the importance of evaluating different designs to identify the best siRNA and shRNA formats for any particular target site and provide a set of highly effective molecules for further development as drug and gene therapies for HIV-1 infection.


Plasmid ◽  
2009 ◽  
Vol 62 (1) ◽  
pp. 50-55 ◽  
Author(s):  
James R. Gilbert ◽  
Christopher S. Adams ◽  
Irving M. Shapiro ◽  
Noreen J. Hickok

2022 ◽  
Author(s):  
N Govardhana Sagar ◽  
A Rajendra Prasad ◽  
Pushpendra Kumar ◽  
Bharat Bhushan ◽  
P Guru Vishnu ◽  
...  

Abstract RNA interference by short hairpin RNAs (shRNAs) is a widely used post transcriptional silencing mechanism for suppressing expression of the target gene. In the current study, five shRNA molecules each against SCD and SREBP1 genes involved in denovo lipid biosynthesis were designed upon considering parameters such as secondary structures of shRNAs, mRNA target regions, GC content and thermodynamic properties (ΔG overall, ΔG duplex and ΔG break-target), synthesized and cloned in pENTR/U6 entry vector to knockdown the expression of SCD and SREBP1 genes. After transfection of these shRNA constructs into the chicken embryonic hepatocytes, expressions of the target genes were monitored by real time PCR. Significant reduction (P<0.05) in the expression of SCD and SREBP1 genes was observed in hepatocytes. The shRNAs against SCD gene showed the knock down efficiency ranged from 20.4% (shRNA5) to 74.2% (shRNA2). In case of SREBP1 gene, the shRNAs showed knock-down efficiency ranging from 26.8% (shRNA4) to 95.85% (shRNA1). The shRNAs against both the genes introduced in chicken hepatocyte cells did not show any significant impact on expression of immune response genes (IFNA and IFNB) in those cells. These results clearly demonstrated the successful down regulation of the expression of SCD and SREBP1 genes by the shRNA molecules against both the target genes under in vitro condition. It is concluded that the shRNA molecules against SCD and SREBP1 genes showed great potential to silence the expression of these genes under in vitro chicken embryonic hepatocyte cells.


2003 ◽  
Vol 13 (2) ◽  
pp. 83-105 ◽  
Author(s):  
Jens Harborth ◽  
Sayda M. Elbashir ◽  
Kim Vandenburgh ◽  
Heiko Manninga ◽  
Stephen A. Scaringe ◽  
...  

2016 ◽  
Vol 3 (1) ◽  
Author(s):  
YASIN JESHIMA KHAN ◽  
HUSNARA Tyagi ◽  
Anil kumar Singh ◽  
Santosh kumar. Magadum

Plants respond through a cascade of reactions resulting in varied cellular environment leading to alterations in the patterns of protein expression resulting in phonotypic changes. Single cell genomics and global proteomics came out to be powerful tools and efficient techniques in studying stress tolerant plants. Non-coding RNAs are a distinct class of regulatory RNAs in plants and animals that control a variety of biological processes. Small ncRNAs play a vital role in post transcriptional gene regulation by either translational repression or by inducing mRNA cleavage. The major classes of small RNAs include microRNAs (miRNAs) and small interfering RNAs (siRNAs), which differ in their biogenesis. miRNAs control the expression of cognate target genes by binding to complementary sequences, resulting in cleavage or translational inhibition of the target RNAs. siRNAs too have a similar structure, function, and biogenesis like miRNAs but are derived from long double-stranded RNAs and can often direct DNA methylation at target sequences.In this review, we focus on the involvement of ncRNAs in comabting abiotic stresses of soybean. This review emphasis on previously known miRNAs as they play important role in several abiotic stresses like drought, salinity, chilling and heat stress by their diverse roles in mediating biological processes like gene expression, chromatin formation, defense of genome against invading viruses. This review attempts to elucidate the various kinds of non-coding RNAs explored, their discovery, biogenesis, functions, and response for different type of abiotic stresses and future aspects for crop improvement in the context of soybean, a representative grain legume.


2006 ◽  
Vol 11 (3) ◽  
pp. 236-246 ◽  
Author(s):  
Laurence H. Lamarcq ◽  
Bradley J. Scherer ◽  
Michael L. Phelan ◽  
Nikolai N. Kalnine ◽  
Yen H. Nguyen ◽  
...  

A method for high-throughput cloning and analysis of short hairpin RNAs (shRNAs) is described. Using this approach, 464 shRNAs against 116 different genes were screened for knockdown efficacy, enabling rapid identification of effective shRNAs against 74 genes. Statistical analysis of the effects of various criteria on the activity of the shRNAs confirmed that some of the rules thought to govern small interfering RNA (siRNA) activity also apply to shRNAs. These include moderate GC content, absence of internal hairpins, and asymmetric thermal stability. However, the authors did not find strong support for positionspecific rules. In addition, analysis of the data suggests that not all genes are equally susceptible to RNAinterference (RNAi).


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Yang Zhang ◽  
Tuan M. Nguyen ◽  
Xiao-Ou Zhang ◽  
Limei Wang ◽  
Tin Phan ◽  
...  

AbstractShort hairpin RNAs (shRNAs) are used to deplete circRNAs by targeting back-splicing junction (BSJ) sites. However, frequent discrepancies exist between shRNA-mediated circRNA knockdown and the corresponding biological effect, querying their robustness. By leveraging CRISPR/Cas13d tool and optimizing the strategy for designing single-guide RNAs against circRNA BSJ sites, we markedly enhance specificity of circRNA silencing. This specificity is validated in parallel screenings by shRNA and CRISPR/Cas13d libraries. Using a CRISPR/Cas13d screening library targeting > 2500 human hepatocellular carcinoma-related circRNAs, we subsequently identify a subset of sorafenib-resistant circRNAs. Thus, CRISPR/Cas13d represents an effective approach for high-throughput study of functional circRNAs.


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