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Sergeeva O, Akhmetova E, Dukova S, Beloglazkina E, Uspenskaya A, Machulkin A, Stetsenko D, Zatsepin T. Structure-activity relationship study of mesyl and busyl phosphoramidate antisense oligonucleotides for unaided and PSMA-mediated uptake into prostate cancer cells. Front Chem 2024; 12:1342178. [PMID: 38501046 PMCID: PMC10944894 DOI: 10.3389/fchem.2024.1342178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 02/13/2024] [Indexed: 03/20/2024] Open
Abstract
Phosphorothioate (PS) group is a key component of a majority of FDA approved oligonucleotide drugs that increase stability to nucleases whilst maintaining interactions with many proteins, including RNase H in the case of antisense oligonucleotides (ASOs). At the same time, uniform PS modification increases nonspecific protein binding that can trigger toxicity and pro-inflammatory effects, so discovery and characterization of alternative phosphate mimics for RNA therapeutics is an actual task. Here we evaluated the effects of the introduction of several N-alkane sulfonyl phosphoramidate groups such as mesyl (methanesulfonyl) or busyl (1-butanesulfonyl) phosphoramidates into gapmer ASOs on the efficiency and pattern of RNase H cleavage, cellular uptake in vitro, and intracellular localization. Using Malat1 lncRNA as a target, we have identified patterns of mesyl or busyl modifications in the ASOs for optimal knockdown in vitro. Combination of the PSMA ligand-mediated delivery with optimized mesyl and busyl ASOs resulted in the efficient target depletion in the prostate cancer cells. Our study demonstrated that other N-alkanesulfonyl phosphoramidate groups apart from a known mesyl phosphoramidate can serve as an essential component of mixed backbone gapmer ASOs to reduce drawbacks of uniformly PS-modified gapmers, and deserve further investigation in RNA therapeutics.
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Affiliation(s)
- O. Sergeeva
- Skolkovo Institute of Science and Technology, Moscow, Russia
| | - E. Akhmetova
- Skolkovo Institute of Science and Technology, Moscow, Russia
| | - S. Dukova
- Skolkovo Institute of Science and Technology, Moscow, Russia
| | - E. Beloglazkina
- Department of Chemistry, Lomonosov Moscow State University, Moscow, Russia
| | - A. Uspenskaya
- Department of Chemistry, Lomonosov Moscow State University, Moscow, Russia
| | - A. Machulkin
- Department of Chemistry, Lomonosov Moscow State University, Moscow, Russia
- Department for Biochemistry, People’s Friendship University of Russia Named after Patrice Lumumba (RUDN University), Moscow, Russia
| | - D. Stetsenko
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - T. Zatsepin
- Department of Chemistry, Lomonosov Moscow State University, Moscow, Russia
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2
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Das S, Forrest J, Kuzminov A. Synthetic lethal mutants in Escherichia coli define pathways necessary for survival with RNase H deficiency. J Bacteriol 2023; 205:e0028023. [PMID: 37819120 PMCID: PMC10601623 DOI: 10.1128/jb.00280-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 09/09/2023] [Indexed: 10/13/2023] Open
Abstract
Ribonucleotides frequently contaminate DNA and, if not removed, cause genomic instability. Consequently, all organisms are equipped with RNase H enzymes to remove RNA-DNA hybrids (RDHs). Escherichia coli lacking RNase HI (rnhA) and RNase HII (rnhB) enzymes, the ∆rnhA ∆rnhB double mutant, accumulates RDHs in its DNA. These RDHs can convert into RNA-containing DNA lesions (R-lesions) of unclear nature that compromise genomic stability. The ∆rnhAB double mutant has severe phenotypes, like growth inhibition, replication stress, sensitivity to ultraviolet radiation, SOS induction, increased chromosomal fragmentation, and defects in nucleoid organization. In this study, we found that RNase HI deficiency also alters wild-type levels of DNA supercoiling. Despite these severe chromosomal complications, ∆rnhAB double mutant survives, suggesting that dedicated pathways operate to avoid or repair R-lesions. To identify these pathways, we systematically searched for mutants synthetic lethal (colethal) with the rnhAB defect using an unbiased color screen and a candidate gene approach. We identified both novel and previously reported rnhAB-colethal and -coinhibited mutants, characterized them, and sorted them into avoidance or repair pathways. These mutants operate in various parts of nucleic acid metabolism, including replication fork progression, R-loop prevention and removal, nucleoid organization, tRNA modification, recombinational repair, and chromosome-dimer resolution, demonstrating the pleiotropic nature of RNase H deficiency. IMPORTANCE Ribonucleotides (rNs) are structurally very similar to deoxyribonucleotides. Consequently, rN contamination of DNA is common and pervasive across all domains of life. Failure to remove rNs from DNA has severe consequences, and all organisms are equipped with RNase H enzymes to remove RNA-DNA hybrids. RNase H deficiency leads to complications in bacteria, yeast, and mouse, and diseases like progressive external ophthalmoplegia (mitochondrial defects in RNASEH1) and Aicardi-Goutières syndrome (defects in RNASEH2) in humans. Escherichia coli ∆rnhAB mutant, deficient in RNases H, has severe chromosomal complications. Despite substantial problems, nearly half of the mutant population survives. We have identified novel and previously confirmed pathways in various parts of nucleic acid metabolism that ensure survival with RNase H deficiency.
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Affiliation(s)
- Sneha Das
- Department of Microbiology, University of Illinois Urbana-Champaign, Urbana, Illinois, USA
| | - Jonathan Forrest
- Department of Microbiology, University of Illinois Urbana-Champaign, Urbana, Illinois, USA
| | - Andrei Kuzminov
- Department of Microbiology, University of Illinois Urbana-Champaign, Urbana, Illinois, USA
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El Boujnouni N, van der Bent ML, Willemse M, ’t Hoen PA, Brock R, Wansink DG. Block or degrade? Balancing on- and off-target effects of antisense strategies against transcripts with expanded triplet repeats in DM1. MOLECULAR THERAPY. NUCLEIC ACIDS 2023; 32:622-636. [PMID: 37200862 PMCID: PMC10185704 DOI: 10.1016/j.omtn.2023.04.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 04/13/2023] [Indexed: 05/20/2023]
Abstract
Antisense oligonucleotide (ASO) therapies for myotonic dystrophy type 1 (DM1) are based on elimination of transcripts containing an expanded repeat or inhibition of sequestration of RNA-binding proteins. This activity is achievable by both degradation of expanded transcripts and steric hindrance, although it is unknown which approach is superior. We compared blocking ASOs with RNase H-recruiting gapmers of equivalent chemistries. Two DMPK target sequences were selected: the triplet repeat and a unique sequence upstream thereof. We assessed ASO effects on transcript levels, ribonucleoprotein foci and disease-associated missplicing, and performed RNA sequencing to investigate on- and off-target effects. Both gapmers and the repeat blocker led to significant DMPK knockdown and a reduction in (CUG)exp foci. However, the repeat blocker was more effective in MBNL1 protein displacement and had superior efficiency in splicing correction at the tested dose of 100 nM. By comparison, on a transcriptome level, the blocking ASO had the fewest off-target effects. In particular, the off-target profile of the repeat gapmer asks for cautious consideration in further therapeutic development. Altogether, our study demonstrates the importance of evaluating both on-target and downstream effects of ASOs in a DM1 context, and provides guiding principles for safe and effective targeting of toxic transcripts.
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Affiliation(s)
- Najoua El Boujnouni
- Department of Medical BioSciences, Research Institute for Medical Innovation, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands
| | - M. Leontien van der Bent
- Department of Medical BioSciences, Research Institute for Medical Innovation, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands
| | - Marieke Willemse
- Department of Medical BioSciences, Research Institute for Medical Innovation, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands
| | - Peter A.C. ’t Hoen
- Department of Medical BioSciences, Research Institute for Medical Innovation, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands
| | - Roland Brock
- Department of Medical BioSciences, Research Institute for Medical Innovation, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands
- Department of Medical Biochemistry, College of Medicine and Medical Sciences, Arabian Gulf University, Manama 293, Bahrain
- Corresponding author Roland Brock, Department of Medical BioSciences, Research Institute for Medical Innovation, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands.
| | - Derick G. Wansink
- Department of Medical BioSciences, Research Institute for Medical Innovation, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands
- Corresponding author Derick G. Wansink, Department of Medical BioSciences, Research Institute for Medical Innovation, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands.
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Pradeep SP, Malik S, Slack FJ, Bahal R. Unlocking the potential of chemically modified peptide nucleic acids for RNA-based therapeutics. RNA (NEW YORK, N.Y.) 2023; 29:434-445. [PMID: 36653113 PMCID: PMC10019372 DOI: 10.1261/rna.079498.122] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 01/12/2023] [Indexed: 05/27/2023]
Abstract
RNA therapeutics have emerged as next-generation therapy for the treatment of many diseases. Unlike small molecules, RNA targeted drugs are not limited by the availability of binding pockets on the protein, but rather utilize Watson-Crick (WC) base-pairing rules to recognize the target RNA and modulate gene expression. Antisense oligonucleotides (ASOs) present a powerful therapeutic approach to treat disorders triggered by genetic alterations. ASOs recognize the cognate site on the target RNA to alter gene expression. Nine single-stranded ASOs have been approved for clinical use and several candidates are in late-stage clinical trials for both rare and common diseases. Several chemical modifications, including phosphorothioates, locked nucleic acid, phosphorodiamidate, morpholino, and peptide nucleic acids (PNAs), have been investigated for efficient RNA targeting. PNAs are synthetic DNA mimics where the deoxyribose phosphate backbone is replaced by N-(2-aminoethyl)-glycine units. The neutral pseudopeptide backbone of PNAs contributes to enhanced binding affinity and high biological stability. PNAs hybridize with the complementary site in the target RNA and act by a steric hindrance--based mechanism. In the last three decades, various PNA designs, chemical modifications, and delivery strategies have been explored to demonstrate their potential as an effective and safe RNA-targeting platform. This review covers the advances in PNA-mediated targeting of coding and noncoding RNAs for a myriad of therapeutic applications.
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Affiliation(s)
- Sai Pallavi Pradeep
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut 06269, USA
| | - Shipra Malik
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut 06269, USA
| | - Frank J Slack
- HMS Initiative for RNA Medicine, Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Raman Bahal
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut 06269, USA
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Begum S, Jabeen S, Rizvi SAH. The pattern of RNA integrity and the expression of housekeeping genes are influenced by sodium hypochlorite and ascorbic acid. AMERICAN JOURNAL OF STEM CELLS 2023; 12:12-22. [PMID: 36937027 PMCID: PMC10018005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 01/20/2023] [Indexed: 03/21/2023]
Abstract
BACKGROUND Basic biological science research deals with nucleic acid isolation. Post-isolation nucleic acid integrity has a pivotal role in further elucidating gene expression and other molecular mechanisms. RNA (ribonucleic acid), cDNA (complementary deoxyribonucleic acid), and PCR (Polymerase chain reaction) products' integrity and quality are affected by several factors in biochemical and biophysical degradation modes. Inadequate evidence was noted about the direct effects of sodium hypochlorite and L-ascorbic acid. OBJECTIVES This study aims to test the effects of sodium hypochlorite (SHC) and L-ascorbic acid (LAA) in total RNA and PCR products, respectively, in an acellular condition. METHODS The study was categorized into three steps total RNA, cDNA, and PCR product evaluations. mBM-MSCs were used to extract RNA and then treated with SHC. Crude total RNA and, after DNase 1 treatment, the bands of total RNA samples were visualized by agarose gel electrophoresis. cDNAs were synthesized from SHC-treated (0.25%) and untreated RNAs, which were also expressed on the gel. LAA (5 µM, 15 µM, 25 µM, and 50 µM) were added to cDNAs synthesized from SHC- and non-SHC-treated samples. Housekeeping genes, Gapdh (Glyceraldehyde 3-phosphate dehydrogenase), and 18S rRNA (18S Ribosomal ribonucleic acid) were amplified in both groups. RESULTS SHC-treated samples produced clearer bands on an agarose gel. Its treatment did not affect the integrated densities of agarose bands which revealed non-significant (P ≤ 0.05) differences in SHC-treated, untreated RNA, and cDNA. However, significant variations were observed at the PCR level. SHC-treated samples expressed decreased housekeeping gene expression in amplified products (Gapdh and 18S rRNA) and slightly but non-significantly high band intensities appeared in the presence of LAA. Significant variable differences (*P ≤ 0.05) were observed between SHC-treated and non-treated groups after LAA treatment. CONCLUSIONS SHC (0.25%) is favorable in removing RNases and maintaining the integrity of RNA. cDNA synthesis did not affect by SHC treatment, and it follows the same as untreated samples after DNase 1 treatment. LAA drew a positive impact to improve the quality of PCR products in terms of band intensities, which is insignificant in SHC-treated RNA. Interestingly, it was revealed from our study that 5-25 µM LAA has the most beneficial role in the acquisition of PCR products, i.e. gene expression. These concentrations can be safely used to improve the quality of gene expression. This phenomenon can be used to achieve other, rarer, desired gene expressions. Further research is needed to explore the effects of SHC on the acquisition of PCR products using other solutions.
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Affiliation(s)
- Sumreen Begum
- Sindh Institute of Urology and Transplantation (SIUT) Karachi-74200, Pakistan
| | - Sehrish Jabeen
- Sindh Institute of Urology and Transplantation (SIUT) Karachi-74200, Pakistan
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Putnam WC, Bashkin JK. Oligonucleotides containing abasic threoninol-terpyridine residues as potential artificial ribonucleases. J Inorg Biochem 2022; 232:111831. [DOI: 10.1016/j.jinorgbio.2022.111831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 04/04/2022] [Accepted: 04/11/2022] [Indexed: 11/24/2022]
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Fleurier S, Dapa T, Tenaillon O, Condon C, Matic I. rRNA operon multiplicity as a bacterial genome stability insurance policy. Nucleic Acids Res 2022; 50:12601-12620. [PMID: 35552441 PMCID: PMC9825170 DOI: 10.1093/nar/gkac332] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 04/12/2022] [Accepted: 04/21/2022] [Indexed: 01/29/2023] Open
Abstract
Quick growth restart after upon encountering favourable environmental conditions is a major fitness contributor in natural environment. It is widely assumed that the time required to restart growth after nutritional upshift is determined by how long it takes for cells to synthesize enough ribosomes to produce the proteins required to reinitiate growth. Here we show that a reduction in the capacity to synthesize ribosomes by reducing number of ribosomal RNA (rRNA) operons (rrn) causes a longer transition from stationary phase to growth of Escherichia coli primarily due to high mortality rates. Cell death results from DNA replication blockage and massive DNA breakage at the sites of the remaining rrn operons that become overloaded with RNA polymerases (RNAPs). Mortality rates and growth restart duration can be reduced by preventing R-loop formation and improving DNA repair capacity. The same molecular mechanisms determine the duration of the recovery phase after ribosome-damaging stresses, such as antibiotics, exposure to bile salts or high temperature. Our study therefore suggests that a major function of rrn operon multiplicity is to ensure that individual rrn operons are not saturated by RNAPs, which can result in catastrophic chromosome replication failure and cell death during adaptation to environmental fluctuations.
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Affiliation(s)
- Sebastien Fleurier
- Department of Infection, Immunity and Inflammation, Institut Cochin, Inserm U1016, CNRS UMR8104, Université de Paris, 75014 Paris, France
| | - Tanja Dapa
- Department of Infection, Immunity and Inflammation, Institut Cochin, Inserm U1016, CNRS UMR8104, Université de Paris, 75014 Paris, France
| | | | - Ciarán Condon
- Institut de Biologie Physico-Chimique, CNRS UMR8261, Université de Paris, 75005 Paris, France
| | - Ivan Matic
- To whom correspondence should be addressed.
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Xie Y, Zhang S, Deng T, Zhang K, Ren J, Li J. A Novel DNAzyme Signal Amplification-based Colorimetric Method for RNase H Assays. ANAL SCI 2021; 37:1675-1680. [PMID: 33162413 DOI: 10.2116/analsci.20p337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A simple visual strategy was developed for the RNase H colorimetric measurement using DNAzyme-mediated signal amplification. When RNase H was presented, the RNA strand of the duplex formed by the G-rich DNA sequence (G-Rich) and its complementary RNA sequence (cp-RNA) was digested, releasing G-Rich to form HRP-mimicking DNAzymes of the G-quadruplex/hemin complexes in the presence of hemin. These DNAzymes catalyze the oxidation reaction of the substrate of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) to produce green-color products of ABTS•-, allowing for the detection of RNase H. A horseradish peroxidase (HRP)-mimicking DNAzyme of the G-quadruplex/hemin complex was used to mediate the signal amplification in the sensing strategy, resulting in high selectivity and sensitivity. This proposed colorimetric method shows a low detection limit of 0.04 U/mL, with a detection range of 0.1 to 3 U/mL. Moreover, this colorimetric method has been successfully used for RNase H assays in complicated biosamples, such as cell lysates. These results indicate that our colorimetric method not only detects RNase H in an ideal system, but also in real samples.
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Affiliation(s)
- Ye Xie
- Institute of Applied Chemistry, School of Science, Hunan Province Key Laboratory of Edible Forestry Resources Safety and Processing Utilization, Central South University of Forestry and Technology
| | - Sina Zhang
- Institute of Applied Chemistry, School of Science, Hunan Province Key Laboratory of Edible Forestry Resources Safety and Processing Utilization, Central South University of Forestry and Technology
| | - Ting Deng
- Institute of Applied Chemistry, School of Science, Hunan Province Key Laboratory of Edible Forestry Resources Safety and Processing Utilization, Central South University of Forestry and Technology
| | - Ke Zhang
- Institute of Applied Chemistry, School of Science, Hunan Province Key Laboratory of Edible Forestry Resources Safety and Processing Utilization, Central South University of Forestry and Technology
| | - Jiali Ren
- Institute of Applied Chemistry, School of Science, Hunan Province Key Laboratory of Edible Forestry Resources Safety and Processing Utilization, Central South University of Forestry and Technology
| | - Jishan Li
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University
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Demelenne A, Servais AC, Crommen J, Fillet M. Analytical techniques currently used in the pharmaceutical industry for the quality control of RNA-based therapeutics and ongoing developments. J Chromatogr A 2021; 1651:462283. [PMID: 34107400 DOI: 10.1016/j.chroma.2021.462283] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 05/14/2021] [Accepted: 05/18/2021] [Indexed: 01/21/2023]
Abstract
The number of RNA-based therapeutics has significantly grown in number on the market over the last 20 years. This number is expected to further increase in the coming years as many RNA therapeutics are being tested in late clinical trials stages. The first part of this paper considers the mechanism of action, the synthesis and the potential impurities resulting from synthesis as well as the strategies used to increase RNA-based therapeutics efficacy. In the second part of this review, the tests that are usually performed in the pharmaceutical industry for the quality testing of antisense oligonucleotides (ASOs), small-interfering RNAs (siRNAs) and messenger RNAs (mRNAs) will be described. In the last part, the remaining challenges and the ongoing developments to meet them are discussed.
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Affiliation(s)
- Alice Demelenne
- Laboratory for the Analysis of Medicines, Department of Pharmacy, Center for Interdisciplinary Research on Medicines (CIRM), University of Liege, Quartier Hôpital, Avenue Hippocrate 15, CHU, B36, Liege 4000, Belgium
| | - Anne-Catherine Servais
- Laboratory for the Analysis of Medicines, Department of Pharmacy, Center for Interdisciplinary Research on Medicines (CIRM), University of Liege, Quartier Hôpital, Avenue Hippocrate 15, CHU, B36, Liege 4000, Belgium
| | - Jacques Crommen
- Laboratory for the Analysis of Medicines, Department of Pharmacy, Center for Interdisciplinary Research on Medicines (CIRM), University of Liege, Quartier Hôpital, Avenue Hippocrate 15, CHU, B36, Liege 4000, Belgium
| | - Marianne Fillet
- Laboratory for the Analysis of Medicines, Department of Pharmacy, Center for Interdisciplinary Research on Medicines (CIRM), University of Liege, Quartier Hôpital, Avenue Hippocrate 15, CHU, B36, Liege 4000, Belgium.
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Kouzminova EA, Kuzminov A. Ultraviolet-induced RNA:DNA hybrids interfere with chromosomal DNA synthesis. Nucleic Acids Res 2021; 49:3888-3906. [PMID: 33693789 PMCID: PMC8053090 DOI: 10.1093/nar/gkab147] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 02/14/2021] [Accepted: 02/23/2021] [Indexed: 12/28/2022] Open
Abstract
Ultraviolet (UV) induces pyrimidine dimers (PDs) in DNA and replication-dependent fragmentation in chromosomes. The rnhAB mutants in Escherichia coli, accumulating R-loops and single DNA-rNs, are generally resistant to DNA damage, but are surprisingly UV-sensitive, even though they remove PDs normally, suggesting irreparable chromosome lesions. We show here that the RNase H defect does not cause additional chromosome fragmentation after UV, but inhibits DNA synthesis after replication restart. Genetic analysis implies formation of R-loop-anchored transcription elongation complexes (R-loop-aTECs) in UV-irradiated rnhAB mutants, predicting that their chromosomal DNA will accumulate: (i) RNA:DNA hybrids; (ii) a few slow-to-remove PDs. We confirm both features and also find that both, surprisingly, depend on replication restart. Finally, enriching for the UV-induced RNA:DNA hybrids in the rnhAB uvrA mutants also co-enriches for PDs, showing their co-residence in the same structures. We propose that PD-triggered R-loop-aTECs block head-on replication in RNase H-deficient mutants.
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Affiliation(s)
- Elena A Kouzminova
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Andrei Kuzminov
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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12
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Wojtyniak M, Schmidtgall B, Kirsch P, Ducho C. Towards Zwitterionic Oligonucleotides with Improved Properties: the NAA/LNA-Gapmer Approach. Chembiochem 2020; 21:3234-3243. [PMID: 32662164 PMCID: PMC7754139 DOI: 10.1002/cbic.202000450] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Indexed: 01/21/2023]
Abstract
Oligonucleotides (ON) are promising therapeutic candidates, for instance by blocking endogenous mRNA (antisense mechanism). However, ON usually require structural modifications of the native nucleic acid backbone to ensure satisfying pharmacokinetic properties. One such strategy to design novel antisense oligonucleotides is to replace native phosphate diester units by positively charged artificial linkages, thus leading to (partially) zwitterionic backbone structures. Herein, we report a "gapmer" architecture comprised of one zwitterionic central segment ("gap") containing nucleosyl amino acid (NAA) modifications and two outer segments of locked nucleic acid (LNA). This NAA/LNA-gapmer approach furnished a partially zwitterionic ON with optimised properties: i) the formation of stable ON-RNA duplexes with base-pairing fidelity and superior target selectivity at 37 °C; and ii) excellent stability in complex biological media. Overall, the NAA/LNA-gapmer approach is thus established as a strategy to design partially zwitterionic ON for the future development of novel antisense agents.
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Affiliation(s)
- Melissa Wojtyniak
- Department of PharmacyPharmaceutical and Medicinal ChemistrySaarland UniversityCampus C2 366123SaarbrückenGermany
| | - Boris Schmidtgall
- Department of ChemistryUniversity of PaderbornWarburger Str. 10033098PaderbornGermany
| | - Philine Kirsch
- Department of PharmacyPharmaceutical and Medicinal ChemistrySaarland UniversityCampus C2 366123SaarbrückenGermany
| | - Christian Ducho
- Department of PharmacyPharmaceutical and Medicinal ChemistrySaarland UniversityCampus C2 366123SaarbrückenGermany
- Department of ChemistryUniversity of PaderbornWarburger Str. 10033098PaderbornGermany
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13
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Pifer R, Greenberg DE. Antisense antibacterial compounds. Transl Res 2020; 223:89-106. [PMID: 32522669 DOI: 10.1016/j.trsl.2020.06.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 05/28/2020] [Accepted: 06/01/2020] [Indexed: 02/08/2023]
Abstract
Extensive antibiotic use combined with poor historical drug stewardship practices have created a medical crisis in which once treatable bacterial infections are now increasingly unmanageable. To combat this, new antibiotics will need to be developed and safeguarded. An emerging class of antibiotics based upon nuclease-stable antisense technologies has proven valuable in preclinical testing against a variety of bacterial pathogens. This review describes the current state of development of antisense-based antibiotics, the mechanisms thus far employed by these compounds, and possible future avenues of research.
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Affiliation(s)
- Reed Pifer
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - David E Greenberg
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas; Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas.
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14
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Mind the Gapmer: Implications of Co-transcriptional Cleavage by Antisense Oligonucleotides. Mol Cell 2020; 77:932-933. [PMID: 32142690 DOI: 10.1016/j.molcel.2020.02.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
While gapmers efficiently knock down as well as terminate transcription of nascent lncRNAs and mRNAs, Lee and Mendell (2020) and Lai et al. (2020) also demonstrate that Pol II termination is not observed with gapmers targeting the 3' terminal portions of the transcript.
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15
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Abstract
Gapmers are antisense oligonucleotides composed of a central DNA segment flanked by nucleotides of modified chemistry. Hybridizing with transcripts by sequence complementarity, gapmers recruit ribonuclease H and induce target RNA degradation. Since its concept first emerged in the 1980s, much work has gone into developing gapmers for use in basic research and therapy. These include improvements in gapmer chemistry, delivery, and therapeutic safety. Gapmers have also successfully entered clinical trials for various genetic disorders, with two already approved by the U.S. Food and Drug Administration for the treatment of familial hypercholesterolemia and transthyretin amyloidosis-associated polyneuropathy. Here, we review the events surrounding the early development of gapmers, from conception to their maturity, and briefly conclude with perspectives on their use in therapy.
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Affiliation(s)
- Kenji Rowel Q Lim
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Toshifumi Yokota
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.
- The Friends of Garrett Cumming Research and Muscular Dystrophy Canada HM Toupin Neurological Science Research Chair, Edmonton, AB, Canada.
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Kojima N, Shrestha AR, Akisawa T, Piao H, Kizawa H, Ohmiya Y, Kurita R. Development of gapmer antisense oligonucleotide with deoxyribonucleic guanidine (DNG) modifications. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2019; 39:258-269. [PMID: 31556356 DOI: 10.1080/15257770.2019.1668563] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The properties of gapmer antisense oligonucleotide (ASO) flanked by deoxyribonucleic guanidine (DNG) were investigated for the potential application in antisense technology. DNG is a unique nucleotide analog which has a positively charged internucleotide guanidinium linkage instead of negatively charged phosphodiester backbone linkage. We prepared a gapmer ASO containing DNG units at both wings of the sequence and compared its properties with 2',4'-BNA/LNA gapmer ASOs with phosphorothioate (PS) backbone. Although DNG gapmer showed no stabilizing effect on the duplex formation with target RNA, the DNG modification was found to be tolerant to exonuclease digestion. Furthermore, DNG gapmer can induce RNase H-mediated cleavage of target RNA molecule, a requisite property for the antisense strategy. Therefore, the DNG gapmer developed in this study could be an interesting and useful candidate for the development of potent ASOs.
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Affiliation(s)
- Naoshi Kojima
- Biomedical Research Institute, DBT-AIST International Laboratory for Advanced Biomedicine (DAILAB), and DBT-AIST International Center for Translational & Environmental Research (DAICENTER), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
| | - Ajaya R Shrestha
- Rena Therapeutics Inc., Shonan Health Innovation Park, Fujisawa, Japan
| | - Takuya Akisawa
- Rena Therapeutics Inc., Shonan Health Innovation Park, Fujisawa, Japan
| | - Haishun Piao
- Rena Therapeutics Inc., Shonan Health Innovation Park, Fujisawa, Japan
| | - Hideki Kizawa
- Rena Therapeutics Inc., Shonan Health Innovation Park, Fujisawa, Japan
| | - Yoshihiro Ohmiya
- Biomedical Research Institute, DBT-AIST International Laboratory for Advanced Biomedicine (DAILAB), and DBT-AIST International Center for Translational & Environmental Research (DAICENTER), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
| | - Ryoji Kurita
- Biomedical Research Institute, DBT-AIST International Laboratory for Advanced Biomedicine (DAILAB), and DBT-AIST International Center for Translational & Environmental Research (DAICENTER), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
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17
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Scoles DR, Pulst SM. Antisense therapies for movement disorders. Mov Disord 2019; 34:1112-1119. [PMID: 31283857 DOI: 10.1002/mds.27782] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 05/10/2019] [Accepted: 06/06/2019] [Indexed: 12/12/2022] Open
Abstract
Currently, few disease-modifying therapies exist for degenerative movement disorders. Antisense oligonucleotides are small DNA oligonucleotides, usually encompassing ∼20 base pairs, that can potentially target any messenger RNA of interest. Antisense oligonucleotides often contain modifications to the phosphate backbone, the sugar moiety, and the nucleotide base. The development of antisense oligonucleotide therapies spinal muscular atrophy and Duchenne muscular dystrophy suggest potentially wide-ranging therapeutic applications for antisense oligonucleotides in neurology. Successes with these two diseases have heightened interest in academia and the pharmaceutical industry to develop antisense oligonucleotides for several movement disorders, including, spinocerebellar ataxias, Huntington's disease, and Parkinson's disease. Compared to small molecules, antisense oligonucleotide-based therapies have an advantage because the target disease gene sequence is the immediate path to identifying the therapeutically effective complementary antisense oligonucleotide. In this review we describe the different types of antisense oligonucleotide chemistries and their potential use for the treatment of human movement disorders. © 2019 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Daniel R Scoles
- Department of Neurology, University of Utah, 175 North Medical Drive East, 5th Floor, Salt Lake City, Utah, USA
| | - Stefan M Pulst
- Department of Neurology, University of Utah, 175 North Medical Drive East, 5th Floor, Salt Lake City, Utah, USA
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18
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Scoles DR, Minikel EV, Pulst SM. Antisense oligonucleotides: A primer. NEUROLOGY-GENETICS 2019; 5:e323. [PMID: 31119194 PMCID: PMC6501637 DOI: 10.1212/nxg.0000000000000323] [Citation(s) in RCA: 121] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 02/14/2019] [Indexed: 12/13/2022]
Abstract
There are few disease-modifying therapeutics for neurodegenerative diseases, but successes on the development of antisense oligonucleotide (ASO) therapeutics for spinal muscular atrophy and Duchenne muscular dystrophy predict a robust future for ASOs in medicine. Indeed, existing pipelines for the development of ASO therapies for spinocerebellar ataxias, Huntington disease, Alzheimer disease, amyotrophic lateral sclerosis, Parkinson disease, and others, and increased focus by the pharmaceutical industry on ASO development, strengthen the outlook for using ASOs for neurodegenerative diseases. Perhaps the most significant advantage to ASO therapeutics over other small molecule approaches is that acquisition of the target sequence provides immediate knowledge of putative complementary oligonucleotide therapeutics. In this review, we describe the various types of ASOs, how they are used therapeutically, and the present efforts to develop new ASO therapies that will contribute to a forthcoming toolkit for treating multiple neurodegenerative diseases.
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Affiliation(s)
- Daniel R Scoles
- Department of Neurology (D.R.S., S.M.P.), University of Utah, Salt Lake City, UT; and Center for the Science of Therapeutics (E.V.M.), Broad Institute of MIT and Harvard, Cambridge, MA
| | - Eric V Minikel
- Department of Neurology (D.R.S., S.M.P.), University of Utah, Salt Lake City, UT; and Center for the Science of Therapeutics (E.V.M.), Broad Institute of MIT and Harvard, Cambridge, MA
| | - Stefan M Pulst
- Department of Neurology (D.R.S., S.M.P.), University of Utah, Salt Lake City, UT; and Center for the Science of Therapeutics (E.V.M.), Broad Institute of MIT and Harvard, Cambridge, MA
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19
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Mesyl phosphoramidate antisense oligonucleotides as an alternative to phosphorothioates with improved biochemical and biological properties. Proc Natl Acad Sci U S A 2019; 116:1229-1234. [PMID: 30622178 PMCID: PMC6347720 DOI: 10.1073/pnas.1813376116] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Forty years of research have shown that antisense oligonucleotides have great potential to target mRNAs of disease-associated genes and noncoding RNAs. Among the vast number of oligonucleotide backbone modifications, phosphorothioate modification is the most widely used in research and the clinic. However, along with their merits are notable drawbacks of phosphorothioate oligonucleotides, including decreased binding affinity to RNA, reduced specificity, and increased toxicity. Here we report the synthesis and in vitro evaluation of the DNA analog mesyl phosphoramidate oligonucleotide. This oligonucleotide type recruits RNase H and shows significant advantages over phosphorothioate in RNA affinity, nuclease stability, and specificity in inhibiting key processes of carcinogenesis. Thus, mesyl phosphoramidate oligonucleotides may be an attractive alternative to phosphorothioates. Here we describe a DNA analog in which the mesyl (methanesulfonyl) phosphoramidate group is substituted for the natural phosphodiester group at each internucleotidic position. The oligomers show significant advantages over the often-used DNA phosphorothioates in RNA-binding affinity, nuclease stability, and specificity of their antisense action, which involves activation of cellular RNase H enzyme for hybridization-directed RNA cleavage. Biological activity of the oligonucleotide analog was demonstrated with respect to pro-oncogenic miR-21. A 22-nt anti–miR-21 mesyl phosphoramidate oligodeoxynucleotide specifically decreased the miR-21 level in melanoma B16 cells, induced apoptosis, reduced proliferation, and impeded migration of tumor cells, showing superiority over isosequential phosphorothioate oligodeoxynucleotide in the specificity of its biological effect. Lower overall toxicity compared with phosphorothioate and more efficient activation of RNase H are the key advantages of mesyl phosphoramidate oligonucleotides, which may represent a promising group of antisense therapeutic agents.
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Abstract
Therapeutics that directly target RNAs are promising for a broad spectrum of disorders, including the neurodegenerative diseases. This is exemplified by the FDA approval of Nusinersen, an antisense oligonucleotide (ASO) therapeutic for spinal muscular atrophy (SMA). RNA targeting therapeutics are currently under development for amyotrophic lateral sclerosis (ALS), Huntington's disease (HD), and spinocerebellar ataxias. We have used an ASO approach toward developing a treatment for spinocerebellar ataxia type 2 (SCA2), for targeting the causative gene ATXN2. We demonstrated that reduction of ATXN2 expression in SCA2 mice treated by intracerebroventicular injection (ICV) of ATXN2 ASO delayed motor phenotype onset, improved the expression of several genes demonstrated abnormally reduced by transcriptomic profiling of SCA2 mice, and restored abnormal Purkinje cell firing frequency in acute cerebellar sections. Here we discuss RNA abnormalities in disease and the prospects of targeting neurodegenerative diseases at the level of RNA control using ASOs and other RNA-targeted therapeutics.
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Affiliation(s)
- Daniel R Scoles
- a Department of Neurology , University of Utah , Salt Lake City , UT , USA
| | - Stefan M Pulst
- a Department of Neurology , University of Utah , Salt Lake City , UT , USA
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21
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Dayeh DM, Kruithoff BC, Nakanishi K. Structural and functional analyses reveal the contributions of the C- and N-lobes of Argonaute protein to selectivity of RNA target cleavage. J Biol Chem 2018. [PMID: 29519815 DOI: 10.1074/jbc.ra117.001051] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Some gene transcripts have cellular functions as regulatory noncoding RNAs. For example, ∼23-nucleotide (nt)-long siRNAs are loaded into Argonaute proteins. The resultant ribonucleoprotein assembly, the RNA-induced silencing complex (RISC), cleaves RNAs that are extensively base-paired with the loaded siRNA. To date, base complementarity is recognized as the major determinant of specific target cleavage (or slicing), but little is known about how Argonaute inspects base pairing before cleavage. A hallmark of Argonaute proteins is their bilobal structure, but despite the significance of this structure for curtailing slicing activity against mismatched targets, the molecular mechanism remains elusive. Here, our structural and functional studies of a bilobed yeast Argonaute protein and its isolated catalytic C-terminal lobe (C-lobe) revealed that the C-lobe alone retains almost all properties of bilobed Argonaute: siRNA-duplex loading, passenger cleavage/ejection, and siRNA-dependent RNA cleavage. A 2.1 Å-resolution crystal structure revealed that the catalytic C-lobe mirrors the bilobed Argonaute in terms of guide-RNA recognition and that all requirements for transitioning to the catalytically active conformation reside in the C-lobe. Nevertheless, we found that in the absence of the N-terminal lobe (N-lobe), target RNAs are scanned for complementarity only at positions 5-14 on a 23-nt guide RNA before endonucleolytic cleavage, thereby allowing for some off-target cleavage. Of note, acquisition of an N-lobe expanded the range of the guide RNA strand used for inspecting target complementarity to positions 2-23. These findings offer clues to the evolution of the bilobal structure of catalytically active Argonaute proteins.
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Affiliation(s)
- Daniel M Dayeh
- From the Center for RNA Biology.,the Department of Chemistry and Biochemistry, and.,the Ohio State Biochemistry Program, Ohio State University, Columbus, Ohio 43210
| | - Bradley C Kruithoff
- From the Center for RNA Biology.,the Department of Chemistry and Biochemistry, and
| | - Kotaro Nakanishi
- From the Center for RNA Biology, .,the Department of Chemistry and Biochemistry, and.,the Ohio State Biochemistry Program, Ohio State University, Columbus, Ohio 43210
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22
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Plashkevych O, Li Q, Chattopadhyaya J. How RNase HI (Escherichia coli) promoted site-selective hydrolysis works on RNA in duplex with carba-LNA and LNA substituted antisense strands in an antisense strategy context? MOLECULAR BIOSYSTEMS 2018; 13:921-938. [PMID: 28352859 DOI: 10.1039/c6mb00762g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A detailed kinetic study of 36 single modified AON-RNA heteroduplexes shows that substitution of a single native nucleotide in the antisense strand (AON) by locked nucleic acid (LNA) or by diastereomerically pure carba-LNA results in site-dependent modulation of RNase H promoted cleavage of complementary mRNA strands by 2 to 5 fold at 5'-GpN-3' cleavage sites, giving up to 70% of the RNA cleavage products. The experiments have been performed using RNase HI of Escherichia coli. The 2nd best cleavage site, being the 5'-ApN-3' sites, cleaves up to 23%, depending upon the substitution site in 36 isosequential complementary AONs. A comparison of the modified AON promoted RNA cleavage rates with that of the native AON shows that sequence-specificity is considerably enhanced as a result of modification. Clearly, relatively weaker 5'-purine (Pu)-pyrimidine (Py)-3' stacking in the complementary RNA strand is preferred (giving ∼90% of total cleavage products), which plays an important role in RNase H promoted RNA cleavage. A plausible mechanism of RNase H mediated cleavage of the RNA has been proposed to be two-fold, dictated by the balancing effect of the aromatic character of the purine aglycone: first, the locally formed 9-guanylate ion (pKa 9.3, ∼18-20% N1 ionized at pH 8) alters the adjoining sugar-phosphate backbone around the scissile phosphate, transforming its sugar N/S conformational equilibrium, to preferential S-type, causing preferential cleavage at 5'-GpN-3' sites around the center of 20 mer complementary mRNA. Second, the weaker nearest-neighbor strength of 5'-Pu-p-Py-3' stacking promotes preferential 5'-GpN-3' and 5'-ApN-3' cleavage, providing ∼90% of the total products, compared to ∼50% in that of the native one, because of the cLNA/LNA substituent effect on the neighboring 5'-Pu-p-Py-3' sites, providing both local steric flexibility and additional hydration. This facilitates both the water and water/Mg2+ ion availability at the cleavage site causing sequence-specific hydrolysis of the phosphodiester bond of scissile phosphate. The enhancement of the total rate of cleavage of the complementary mRNA strand by up to 25%, presented in this work, provides opportunities to engineer a single modification site in appropriately substituted AONs to design an effective antisense strategy based on the nucleolytic stability of the AON strand versus RNase H capability to cleave the complementary RNA strand.
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Affiliation(s)
- Oleksandr Plashkevych
- Chemical Biology Program, Department of Cell and Molecular Biology, Biomedical Center, Uppsala University, Box 581, SE-751 23 Uppsala, Sweden.
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23
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Hong Y, Li L, Luan G, Drlica K, Zhao X. Contribution of reactive oxygen species to thymineless death in Escherichia coli. Nat Microbiol 2017; 2:1667-1675. [PMID: 28970486 PMCID: PMC5705385 DOI: 10.1038/s41564-017-0037-y] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 09/05/2017] [Indexed: 02/06/2023]
Affiliation(s)
- Yuzhi Hong
- Public Health Research Institute and Department of Microbiology, Biochemistry & Molecular Genetics, New Jersey Medical School, Rutgers University, 225 Warren Street, Newark, NJ, 07103, USA
| | - Liping Li
- Public Health Research Institute and Department of Microbiology, Biochemistry & Molecular Genetics, New Jersey Medical School, Rutgers University, 225 Warren Street, Newark, NJ, 07103, USA
| | - Gan Luan
- Public Health Research Institute and Department of Microbiology, Biochemistry & Molecular Genetics, New Jersey Medical School, Rutgers University, 225 Warren Street, Newark, NJ, 07103, USA
| | - Karl Drlica
- Public Health Research Institute and Department of Microbiology, Biochemistry & Molecular Genetics, New Jersey Medical School, Rutgers University, 225 Warren Street, Newark, NJ, 07103, USA
| | - Xilin Zhao
- Public Health Research Institute and Department of Microbiology, Biochemistry & Molecular Genetics, New Jersey Medical School, Rutgers University, 225 Warren Street, Newark, NJ, 07103, USA. .,State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, South Xiang-An Road, Xiang-An District, Xiamen, Fujian Province, 361102, China.
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24
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Kouzminova EA, Kadyrov FF, Kuzminov A. RNase HII Saves rnhA Mutant Escherichia coli from R-Loop-Associated Chromosomal Fragmentation. J Mol Biol 2017; 429:2873-2894. [PMID: 28821455 DOI: 10.1016/j.jmb.2017.08.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2017] [Revised: 08/09/2017] [Accepted: 08/10/2017] [Indexed: 01/02/2023]
Abstract
The rnhAB mutant Escherichia coli, deficient in two RNase H enzymes that remove both R-loops and incorporated ribonucleotides (rNs) from DNA, grow slowly, suggesting accumulation of rN-containing DNA lesions (R-lesions). We report that the rnhAB mutants have reduced viability, form filaments with abnormal nucleoids, induce SOS, and fragment their chromosome, revealing replication and/or segregation stress. R-loops are known to interfere with replication forks, and sensitivity of the double rnhAB mutants to translation inhibition points to R-loops as precursors for R-lesions. However, the strict specificity of bacterial RNase HII for RNA-DNA junctions indicates that R-lesions have rNs integrated into DNA. Indeed, instead of relieving problems of rnhAB mutants, transient inhibition of replication from oriC kills them, suggesting that oriC-initiated replication removes R-loops instead of compounding them to R-lesions. Yet, replication from an R-loop-initiating plasmid origin kills the double rnhAB mutant, revealing generation of R-lesions by R-loop-primed DNA synthesis. These R-lesions could be R-tracts, contiguous runs of ≥4 RNA nucleotides within DNA strand and the only common substrate between the two bacterial RNase H enzymes. However, a plasmid relaxation test failed to detect R-tracts in DNA of the rnhAB mutants, although it readily detected R-patches (runs of 1-3 rNs). Instead, we detected R-gaps, single-strand gaps containing rNs, in the chromosomal DNA of the rnhAB mutant. Therefore, we propose that RNase H-deficient mutants convert some R-loops into R-tracts, which progress into R-gaps and then to double-strand breaks-explaining why R-tracts do not accumulate in RNase H-deficient cells, while double-strand breaks do.
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Affiliation(s)
- Elena A Kouzminova
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Farid F Kadyrov
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Andrei Kuzminov
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
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25
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Istrate A, Katolik A, Istrate A, Leumann CJ. 2'β-Fluoro-Tricyclo Nucleic Acids (2'F-tc-ANA): Thermal Duplex Stability, Structural Studies, and RNase H Activation. Chemistry 2017; 23:10310-10318. [PMID: 28477335 DOI: 10.1002/chem.201701476] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Indexed: 01/16/2023]
Abstract
We describe the synthesis, thermal stability, structural and RNase H activation properties of 2'β-fluoro-tricyclo nucleic acids (2'F-tc-ANA). Three 2'F-tc-ANA nucleosides (T, 5Me C and A) were synthesized starting from a previously described fluorinated tricyclo sugar intermediate. NMR analysis and quantum mechanical calculations indicate that 2'F-tc-ANA nucleosides prefer sugar conformations in the East and South regions of the pseudorotational cycle. UV-melting experiments revealed that non-consecutive insertions of 2'F-tc-ANA units in DNA reduce the affinity to DNA and RNA complements. However, an oligonucleotide with five contiguous 2'F-tc-ANA-T insertions exhibits increased affinity to complementary RNA. Moreover, a fully modified 10-mer 2'F-tc-ANA oligonucleotide paired to both DNA (+1.6 °C/mod) and RNA (+2.5 °C/mod) with significantly higher affinity compared to corresponding unmodified DNA, and similar affinity compared to corresponding tc-DNA. In addition, CD spectroscopy and molecular dynamics simulations indicate that the conformation of the 2'F-tc-ANA/RNA duplex is similar to that of a DNA/RNA duplex. Moreover, in some sequence contexts, 2'F-tc-ANA promotes RNase H-mediated cleavage of a complementary RNA strand. Taken together, 2'F-tc-ANA represents a nucleic acid analogue that offers the advantage of high RNA affinity while maintaining the ability to activate RNase H, and can be considered a prospective candidate for gene silencing applications.
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Affiliation(s)
- Alena Istrate
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012, Bern, Switzerland
| | - Adam Katolik
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012, Bern, Switzerland
| | - Andrei Istrate
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012, Bern, Switzerland
| | - Christian J Leumann
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012, Bern, Switzerland
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26
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Islam MA, Waki R, Fujisaka A, Ito KR, Obika S. In vitro and in vivo biophysical properties of oligonucleotides containing 5'-thio nucleosides. Drug Discov Ther 2017; 10:263-270. [PMID: 27890900 DOI: 10.5582/ddt.2016.01055] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Phosphorothioate modification is one of the most widely investigated and promising chemical modifications in oligonucleotide (ON) based therapeutics. Structurally similar 5'-thio or phosphorothiolate-modified nucleotides, in which a 5'-bridging oxygen is replaced with a sulfur atom, are gaining importance for ON-based research. Several reports have been published describing the synthesis of 5'-thio-modified ONs but no detailed in vitro and in vivo data are available. Here, we report the synthesis of 5'-thio-modified 2'-deoxy-5-methylcytidine. 5'-Thio-modified thymidine and 2'-deoxy-5-methylcytidine were incorporated into target ONs, then we evaluated their binding affinity, nuclease stability, RNase H mediated scission, stability in blood serum, and in vitro and in vivo activity. This is the first report showing the influence of 5'-thio-modified antisense ONs in in vitro and in vivo experiments.
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Affiliation(s)
- Md Ariful Islam
- Graduate School of Pharmaceutical Sciences, Osaka University
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27
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Yamamoto T, Wada F, Harada-Shiba M. Development of Antisense Drugs for Dyslipidemia. J Atheroscler Thromb 2016; 23:1011-25. [PMID: 27466159 PMCID: PMC5090806 DOI: 10.5551/jat.rv16001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Abnormal elevation of low-density lipoprotein (LDL) and triglyceride-rich lipoproteins in plasma as well as dysfunction of anti-atherogenic high-density lipoprotein (HDL) have both been recognized as essential components of the pathogenesis of atherosclerosis and are classified as dyslipidemia. This review describes the arc of development of antisense oligonucleotides for the treatment of dyslipidemia. Chemically-armed antisense candidates can act on various kinds of transcripts, including mRNA and miRNA, via several different endogenous antisense mechanisms, and have exhibited potent systemic anti-dyslipidemic effects. Here, we present specific cutting-edge technologies have recently been brought into antisense strategies, and describe how they have improved the potency of antisense drugs in regard to pharmacokinetics and pharmacodynamics. In addition, we discuss perspectives for the use of armed antisense oligonucleotides as new clinical options for dyslipidemia, in the light of outcomes of recent clinical trials and safety concerns indicated by several clinical and preclinical studies.
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28
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Gerasimova YV, Kolpashchikov DM. Towards a DNA Nanoprocessor: Reusable Tile-Integrated DNA Circuits. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201603265] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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29
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Gerasimova YV, Kolpashchikov DM. Towards a DNA Nanoprocessor: Reusable Tile-Integrated DNA Circuits. Angew Chem Int Ed Engl 2016; 55:10244-7. [DOI: 10.1002/anie.201603265] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2016] [Revised: 06/05/2016] [Indexed: 11/06/2022]
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30
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Abstract
DNA replication in Escherichia coli initiates at oriC, the origin of replication and proceeds bidirectionally, resulting in two replication forks that travel in opposite directions from the origin. Here, we focus on events at the replication fork. The replication machinery (or replisome), first assembled on both forks at oriC, contains the DnaB helicase for strand separation, and the DNA polymerase III holoenzyme (Pol III HE) for DNA synthesis. DnaB interacts transiently with the DnaG primase for RNA priming on both strands. The Pol III HE is made up of three subassemblies: (i) the αɛθ core polymerase complex that is present in two (or three) copies to simultaneously copy both DNA strands, (ii) the β2 sliding clamp that interacts with the core polymerase to ensure its processivity, and (iii) the seven-subunit clamp loader complex that loads β2 onto primer-template junctions and interacts with the α polymerase subunit of the core and the DnaB helicase to organize the two (or three) core polymerases. Here, we review the structures of the enzymatic components of replisomes, and the protein-protein and protein-DNA interactions that ensure they remain intact while undergoing substantial dynamic changes as they function to copy both the leading and lagging strands simultaneously during coordinated replication.
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Affiliation(s)
- J S Lewis
- Centre for Medical & Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia
| | - S Jergic
- Centre for Medical & Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia
| | - N E Dixon
- Centre for Medical & Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia.
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31
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Barrett GL, Naim T, Trieu J, Huang M. In vivo knockdown of basal forebrain p75 neurotrophin receptor stimulates choline acetyltransferase activity in the mature hippocampus. J Neurosci Res 2016; 94:389-400. [DOI: 10.1002/jnr.23717] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2015] [Revised: 12/15/2015] [Accepted: 01/11/2016] [Indexed: 11/09/2022]
Affiliation(s)
- Graham L. Barrett
- Department of Physiology; University of Melbourne; Melbourne Victoria Australia
| | - Timur Naim
- Department of Physiology; University of Melbourne; Melbourne Victoria Australia
| | - Jennifer Trieu
- Department of Physiology; University of Melbourne; Melbourne Victoria Australia
| | - Mengjie Huang
- Department of Physiology; University of Melbourne; Melbourne Victoria Australia
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32
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Urbanska AM, Karagiannis ED, Au AS, Dai SY, Mozafari M, Prakash S. What's Next for Gastrointestinal Disorders: No Needles? J Control Release 2015; 221:48-61. [PMID: 26646543 DOI: 10.1016/j.jconrel.2015.11.031] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 11/26/2015] [Accepted: 11/27/2015] [Indexed: 12/28/2022]
Abstract
A myriad of pathologies affect the gastrointestinal tract, citing this affected area as a significant target for therapeutic intervention. One group of therapeutic agents, antisense and oligonucleotides and small interfering RNAs, offer a promising platform for treating a wide variety of diseases ranging from cancer to auto-immune diseases. Current delivery methods are carried out either systemically or locally into diseased areas, both of which involve needles. The challenge in orally administering this type of treatment lies in the complications that arise due to the vast environmental extremes found within the gastrointestinal tract, owing to the fact that, as the drug travels down the gastrointestinal tract, it is subjected to pH changes and interactions with bacteria and a variety of digestive and protective enzymes including proteases, DNAses, and RNAses. Overcoming these challenges to allow the practical application of these drugs is a priority that has invoked a multitude of research in the chemical, biological, and material sciences. In this review, we will address common gastrointestinal pathologies, the barriers to oral-based therapies and antisense-interfering technologies, the approaches that have already been applied for their delivery, and the current status of antisense drug therapy clinical trials for gastrointestinal-related disorders.
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Affiliation(s)
- Aleksandra M Urbanska
- Biomedical Technology and Cell Therapy Research Laboratory, Departments of Biomedical Engineering and Physiology Artificial Cells and Organs Research Center, Faculty of Medicine, McGill University, 3775 University Street, Montreal, Quebec, Canada
| | - Emmanouil D Karagiannis
- Synthetic Neurobiology Group, Massachusetts Institute of Technology Media Lab and McGovern Institute, Departments of Biological Engineering and Brain and Cognitive Sciences, Cambridge, MA 02139, USA
| | - Andrew S Au
- Division of Digestive and Liver Diseases, Columbia University College of Physicians and Surgeons, New York, NY 10032-3802, USA
| | - Si Yuan Dai
- Biomedical Technology and Cell Therapy Research Laboratory, Departments of Biomedical Engineering and Physiology Artificial Cells and Organs Research Center, Faculty of Medicine, McGill University, 3775 University Street, Montreal, Quebec, Canada
| | - Masoud Mozafari
- Bioengineering Research Group, Nanotechnology and Advanced Materials Department, Materials and Energy Research Center (MERC), P.O. Box 14155-4777, Tehran, Iran.
| | - Satya Prakash
- Biomedical Technology and Cell Therapy Research Laboratory, Departments of Biomedical Engineering and Physiology Artificial Cells and Organs Research Center, Faculty of Medicine, McGill University, 3775 University Street, Montreal, Quebec, Canada
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Magner D, Biala E, Lisowiec-Wachnicka J, Kierzek E, Kierzek R. A Tandem Oligonucleotide Approach for SNP-Selective RNA Degradation Using Modified Antisense Oligonucleotides. PLoS One 2015; 10:e0142139. [PMID: 26544037 PMCID: PMC4704561 DOI: 10.1371/journal.pone.0142139] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 10/19/2015] [Indexed: 12/19/2022] Open
Abstract
Antisense oligonucleotides have been studied for many years as a tool for gene silencing. One of the most difficult cases of selective RNA silencing involves the alleles of single nucleotide polymorphisms, in which the allele sequence is differentiated by a single nucleotide. A new approach to improve the performance of allele selectivity for antisense oligonucleotides is proposed. It is based on the simultaneous application of two oligonucleotides. One is complementary to the mutated form of the targeted RNA and is able to activate RNase H to cleave the RNA. The other oligonucleotide, which is complementary to the wild type allele of the targeted RNA, is able to inhibit RNase H cleavage. Five types of SNPs, C/G, G/C, G/A, A/G, and C/U, were analyzed within the sequence context of genes associated with neurodegenerative disorders such as Alzheimer’s disease, Parkinson’s disease, ALS (Amyotrophic Lateral Sclerosis), and Machado-Joseph disease. For most analyzed cases, the application of the tandem approach increased allele-selective RNA degradation 1.5–15 fold relative to the use of a single antisense oligonucleotide. The presented study proves that differentiation between single substitution is highly dependent on the nature of the SNP and surrounding nucleotides. These variables are crucial for determining the proper length of the inhibitor antisense oligonucleotide. In the tandem approach, the comparison of thermodynamic stability of the favorable duplexes WT RNA-inhibitor and Mut RNA-gapmer with the other possible duplexes allows for the evaluation of chances for the allele-selective degradation of RNA. A larger difference in thermodynamic stability between favorable duplexes and those that could possibly form, usually results in the better allele selectivity of RNA degradation.
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Affiliation(s)
- Dorota Magner
- Institute of Bioorganic Chemistry Polish Academy of Sciences, 61-704 Poznan, Noskowskiego, 12/14, Poland
| | - Ewa Biala
- Institute of Bioorganic Chemistry Polish Academy of Sciences, 61-704 Poznan, Noskowskiego, 12/14, Poland
| | - Jolanta Lisowiec-Wachnicka
- Institute of Bioorganic Chemistry Polish Academy of Sciences, 61-704 Poznan, Noskowskiego, 12/14, Poland
| | - Elzbieta Kierzek
- Institute of Bioorganic Chemistry Polish Academy of Sciences, 61-704 Poznan, Noskowskiego, 12/14, Poland
| | - Ryszard Kierzek
- Institute of Bioorganic Chemistry Polish Academy of Sciences, 61-704 Poznan, Noskowskiego, 12/14, Poland
- * E-mail:
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Abstract
Tracking the evolution of thermostability in resurrected ancestors of a heat-tolerant extremophile protein and its less heat tolerant Escherichia coli homologue shows how thermostability has probably explored different mechanisms of protein stabilization over evolutionary time. Proteins from thermophiles are generally more thermostable than their mesophilic homologs, but little is known about the evolutionary process driving these differences. Here we attempt to understand how the diverse thermostabilities of bacterial ribonuclease H1 (RNH) proteins evolved. RNH proteins from Thermus thermophilus (ttRNH) and Escherichia coli (ecRNH) share similar structures but differ in melting temperature (Tm) by 20°C. ttRNH's greater stability is caused in part by the presence of residual structure in the unfolded state, which results in a low heat capacity of unfolding (ΔCp) relative to ecRNH. We first characterized RNH proteins from a variety of extant bacteria and found that Tm correlates with the species' growth temperatures, consistent with environmental selection for stability. We then used ancestral sequence reconstruction to statistically infer evolutionary intermediates along lineages leading to ecRNH and ttRNH from their common ancestor, which existed approximately 3 billion years ago. Finally, we synthesized and experimentally characterized these intermediates. The shared ancestor has a melting temperature between those of ttRNH and ecRNH; the Tms of intermediate ancestors along the ttRNH lineage increased gradually over time, while the ecRNH lineage exhibited an abrupt drop in Tm followed by relatively little change. To determine whether the underlying mechanisms for thermostability correlate with the changes in Tm, we measured the thermodynamic basis for stabilization—ΔCp and other thermodynamic parameters—for each of the ancestors. We observed that, while the Tm changes smoothly, the mechanistic basis for stability fluctuates over evolutionary time. Thus, even while overall stability appears to be strongly driven by selection, the proteins explored a wide variety of mechanisms of stabilization, a phenomenon we call “thermodynamic system drift.” This suggests that even on lineages with strong selection to increase stability, proteins have wide latitude to explore sequence space, generating biophysical diversity and potentially opening new evolutionary pathways. The biophysical properties of proteins must adjust to accommodate environmental temperatures because of the narrow range over which any given protein sequence can remain folded and functional. We compared the evolution of homologous bacterial enzymes (ribonucleases H1) from two lineages: one from Escherichia coli, which live at moderate temperatures, the other from Thermus thermophilus, which live at extremely high temperatures. Our aim was to investigate how these structurally homologous proteins can have such different thermostabilities, unfolding at temperatures that are 20°C apart. We used bioinformatics to reconstruct the sequences of ancestral proteins along each lineage, synthesized the proteins in the lab, and experimentally traced the evolution of ribonuclease H1 stability. While thermostability appears to have been strongly shaped by selection, the biophysical mechanisms used to tune protein stability appear to have varied throughout evolutionary history; this suggests that proteins have wide latitude to explore different mechanisms of stabilization, generating biophysical diversity and opening up new evolutionary pathways.
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Trembley JH, Unger GM, Korman VL, Abedin MJ, Nacusi LP, Vogel RI, Slaton JW, Kren BT, Ahmed K. Tenfibgen ligand nanoencapsulation delivers bi-functional anti-CK2 RNAi oligomer to key sites for prostate cancer targeting using human xenograft tumors in mice. PLoS One 2014; 9:e109970. [PMID: 25333839 PMCID: PMC4198192 DOI: 10.1371/journal.pone.0109970] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Accepted: 09/02/2014] [Indexed: 01/11/2023] Open
Abstract
Protected and specific delivery of nucleic acids to malignant cells remains a highly desirable approach for cancer therapy. Here we present data on the physical and chemical characteristics, mechanism of action, and pilot therapeutic efficacy of a tenfibgen (TBG)-shell nanocapsule technology for tumor-directed delivery of single stranded DNA/RNA chimeric oligomers targeting CK2αα' to xenograft tumors in mice. The sub-50 nm size TBG nanocapsule (s50-TBG) is a slightly negatively charged, uniform particle of 15 - 20 nm size which confers protection to the nucleic acid cargo. The DNA/RNA chimeric oligomer (RNAi-CK2) functions to decrease CK2αα' expression levels via both siRNA and antisense mechanisms. Systemic delivery of s50-TBG-RNAi-CK2 specifically targets malignant cells, including tumor cells in bone, and at low doses reduces size and CK2-related signals in orthotopic primary and metastatic xenograft prostate cancer tumors. In conclusion, the s50-TBG nanoencapsulation technology together with the chimeric oligomer targeting CK2αα' offer significant promise for systemic treatment of prostate malignancy.
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Affiliation(s)
- Janeen H. Trembley
- Research Service, Minneapolis VA Health Care System, Minneapolis, Minnesota, United States of America
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, Minnesota, United States of America
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota, United States of America
| | | | - Vicci L. Korman
- GeneSegues Inc., Chaska, Minnesota, United States of America
| | - Md. Joynal Abedin
- Research Service, Minneapolis VA Health Care System, Minneapolis, Minnesota, United States of America
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Lucas P. Nacusi
- GeneSegues Inc., Chaska, Minnesota, United States of America
| | - Rachel I. Vogel
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Joel W. Slaton
- Department of Urology, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Betsy T. Kren
- Research Service, Minneapolis VA Health Care System, Minneapolis, Minnesota, United States of America
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota, United States of America
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Khalil Ahmed
- Research Service, Minneapolis VA Health Care System, Minneapolis, Minnesota, United States of America
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, Minnesota, United States of America
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota, United States of America
- Department of Urology, University of Minnesota, Minneapolis, Minnesota, United States of America
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Yamamoto T, Fujii N, Yasuhara H, Wada S, Wada F, Shigesada N, Harada-Shiba M, Obika S. Evaluation of multiple-turnover capability of locked nucleic acid antisense oligonucleotides in cell-free RNase H-mediated antisense reaction and in mice. Nucleic Acid Ther 2014; 24:283-90. [PMID: 24758560 DOI: 10.1089/nat.2013.0470] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The multiple-turnover ability of a series of locked nucleic acid (LNA)-based antisense oligonucleotides (AONs) in the RNase H-mediated scission reaction was estimated using a newly developed cell-free reaction system. We determined the initial reaction rates of AONs under multiple-turnover conditions and found that among 24 AONs tested, AONs with melting temperatures (Tm) of 40°C-60°C efficiently elicit multiple rounds of RNA scission. On the other hand, by measuring Tm with two 10-mer RNAs partially complementary to AONs as models of cleaved 5' and 3' fragments of mRNA, we found that AONs require adequate binding affinity for efficient turnover activities. We further demonstrated that the efficacy of a set of 13-mer AONs in mice correlated with their turnover efficiency, indicating that the intracellular situation where AONs function is similar to multiple-turnover conditions. Our methodology and findings may provide an opportunity to shed light on a previously unknown antisense mechanism, leading to further improvement of the activity and safety profiles of AONs.
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Affiliation(s)
- Tsuyoshi Yamamoto
- 1 Graduate School of Pharmaceutical Sciences, Osaka University , Suita, Osaka, Japan
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37
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Šipova H, Špringer T, Rejman D, Šimak O, Petrová M, Novák P, Rosenbergová Š, Páv O, Liboska R, Barvík I, Štěpanek J, Rosenberg I, Homola J. 5'-O-Methylphosphonate nucleic acids--new modified DNAs that increase the Escherichia coli RNase H cleavage rate of hybrid duplexes. Nucleic Acids Res 2014; 42:5378-89. [PMID: 24523351 PMCID: PMC4005664 DOI: 10.1093/nar/gku125] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Several oligothymidylates containing various ratios of phosphodiester and isopolar 5'-hydroxyphosphonate, 5'-O-methylphosphonate and 3'-O-methylphosphonate internucleotide linkages were examined with respect to their hybridization properties with oligoriboadenylates and their ability to induce RNA cleavage by ribonuclease H (RNase H). The results demonstrated that the increasing number of 5'-hydroxyphosphonate or 5'-O-methylphosphonate units in antisense oligonucleotides (AOs) significantly stabilizes the heteroduplexes, whereas 3'-O-methylphosphonate AOs cause strong destabilization of the heteroduplexes. Only the heteroduplexes with 5'-O-methylphosphonate units in the antisense strand exhibited a significant increase in Escherichia coli RNase H cleavage activity by up to 3-fold (depending on the ratio of phosphodiester and phosphonate linkages) in comparison with the natural heteroduplex. A similar increase in RNase H cleavage activity was also observed for heteroduplexes composed of miRNA191 and complementary AOs containing 5'-O-methylphosphonate units. We propose for this type of AOs, working via the RNase H mechanism, the abbreviation MEPNA (MEthylPhosphonate Nucleic Acid).
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Affiliation(s)
- Hana Šipova
- Institute of Photonics and Electronics AS CR, v.v.i., Chaberská 57, 182 51 Prague, Czech Republic, Institute of Organic Chemistry and Biochemistry AS CR, v.v.i., Flemingovo nám. 2., 166 10 Prague, Czech Republic and Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 3, 121 16 Prague, Czech Republic
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38
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Rush AM, Thompson MP, Tatro ET, Gianneschi NC. Nuclease-resistant DNA via high-density packing in polymeric micellar nanoparticle coronas. ACS NANO 2013; 7:1379-87. [PMID: 23379679 PMCID: PMC3608424 DOI: 10.1021/nn305030g] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Herein, we describe a polymeric micellar nanoparticle capable of rendering nucleic acids resistant to nuclease digestion. This approach relies on utilizing DNA as the polar headgroup of a DNA-polymer amphiphile in order to assemble well-defined, discrete nanoparticles. Dense packing of DNA in the micelle corona allows for hybridization of complementary oligonucleotides while prohibiting enzymatic degradation. We demonstrate the preparation, purification, and characterization of the nanoparticles, then describe their resistance to treatment with endo- and exonucleases including snake-venom phosphodiesterase (SVP), a common, general DNA digestion enzyme.
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Affiliation(s)
- Anthony M Rush
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA
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39
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Liu B, Xiang D, Long Y, Tong C. Real time monitoring of junction ribonuclease activity of RNase H using chimeric molecular beacons. Analyst 2013; 138:3238-45. [DOI: 10.1039/c3an36414c] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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40
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Hagihara S, Kusano S, Lin WC, Chao XG, Hori T, Imoto S, Nagatsugi F. Production of truncated protein by the crosslink formation of mRNA with 2'-OMe oligoribonucleotide containing 2-amino-6-vinylpurine. Bioorg Med Chem Lett 2012; 22:3870-2. [PMID: 22613261 DOI: 10.1016/j.bmcl.2012.04.123] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Revised: 04/27/2012] [Accepted: 04/28/2012] [Indexed: 12/29/2022]
Abstract
The development of convenient methods for controlling the protein expression is an important challenge in the postgenomic era. We applied the crosslink forming oligonucleotide (CFO) as a terminator of the ribosomal translation. In this study, we demonstrated that the improved reactivity of our CFO under physiological conditions enabled the sequence-specific introduction of a steric block for a ribosome on mRNAs. In vitro and in cell translation experiments revealed that the crosslinked mRNA can produce the truncated proteins in which the translation terminates at the desired position.
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Affiliation(s)
- Shinya Hagihara
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Miyagi 980-8577, Japan
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41
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Abstract
RNA-based applications requiring high-quality, non-degraded RNA are a foundational element of many research studies. As such, it is paramount that the integrity of experimental RNA is validated prior to cDNA synthesis or other downstream applications. In the absence of expensive equipment such as microfluidic electrophoretic devices, and as an alternative to the costly and time-consuming standard formaldehyde gel, RNA quality can be quickly analyzed by adding small amounts of commercial bleach to TAE buffer-based agarose gels prior to electrophoresis. In the presence of low concentrations of bleach, the secondary structure of RNA is denatured and potential contaminating RNases are destroyed. Because of this, the 'bleach gel' is a functional approach that addresses the need for an inexpensive and safe way to evaluate RNA integrity and will improve the ability of researchers to rapidly analyze RNA quality.
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Affiliation(s)
- Patrick S. Aranda
- Department of Biological Sciences, Boise State University, Boise, ID, 83725, USA
| | - Dollie M. LaJoie
- Department of Biological Sciences, Boise State University, Boise, ID, 83725, USA
| | - Cheryl L. Jorcyk
- Department of Biological Sciences, Boise State University, Boise, ID, 83725, USA
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42
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Grimpe B. Deoxyribozymes and bioinformatics: complementary tools to investigate axon regeneration. Cell Tissue Res 2011; 349:181-200. [PMID: 22190188 PMCID: PMC7087747 DOI: 10.1007/s00441-011-1291-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2011] [Accepted: 11/17/2011] [Indexed: 11/28/2022]
Abstract
For over 100 years, scientists have tried to understand the mechanisms that lead to the axonal growth seen during development or the lack thereof during regeneration failure after spinal cord injury (SCI). Deoxyribozyme technology as a potential therapeutic to treat SCIs or other insults to the brain, combined with a bioinformatics approach to comprehend the complex protein-protein interactions that occur after such trauma, is the focus of this review. The reader will be provided with information on the selection process of deoxyribozymes and their catalytic sequences, on the mechanism of target digestion, on modifications, on cellular uptake and on therapeutic applications and deoxyribozymes are compared with ribozymes, siRNAs and antisense technology. This gives the reader the necessary knowledge to decide which technology is adequate for the problem at hand and to design a relevant agent. Bioinformatics helps to identify not only key players in the complex processes that occur after SCI but also novel or less-well investigated molecules against which new knockdown agents can be generated. These two tools used synergistically should facilitate the pursuit of a treatment for insults to the central nervous system.
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Affiliation(s)
- Barbara Grimpe
- Applied Neurobiology, Department of Neurology, Heinrich Heine University Düsseldorf, Moorenstrasse 5, 40225 Düsseldorf, Germany.
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43
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Abstract
Numerous chemically modified oligonucleotides have been developed so far and show their own unique chemical properties and pharmacodynamic/pharmacokinetic characteristics. Among all non-natural nucleotides, to the best of our knowledge, only five chemistries are currently being tested in clinical trials: phosphorothioate, 2´-O-methyl RNA, 2´-O-methoxyethyl RNA, 2´,4´-bridged nucleic acid/locked nucleic acid and the phosphorodiamidate morpholino oligomer. Since phosphorothioate modification can improve the pharmacokinetics of oligonucleotides, this modification is currently used in combination with all other modifications except phosphorodiamidate morpholino oligomer. For the treatment of metabolic, cardiovascular, cancer and other systemic diseases, the phosphorothioate class of drugs is obviously helpful, while superior efficacies can be observed in phosphorodiamidate morpholino oligomer compared to other classes of oligonucleotides for the treatment of Duchenne muscular dystrophy. Which properties of antisense molecules are actually essential for clinical applications? In this article, we provide an overview of the medicinal chemistry of existing non-natural antisense molecules, as well as their clinical applications, to discuss which properties of antisense oligonuculeotides affect therapeutic potency.
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44
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Lecosnier S, Cordier C, Simon P, François JC, Saison-Behmoaras TE. A steric blocker of translation elongation inhibits IGF-1R expression and cell transformation. FASEB J 2011; 25:2201-10. [PMID: 21402719 DOI: 10.1096/fj.10-169540] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The insulin-like growth factor 1 receptor (IGF-1R) is involved in transformation, survival, mitogenesis and differentiation. It is overexpressed in many tumors and a validated target for anticancer therapy. In cell-free systems, polypyrimidic peptide nucleic acids (PNAs) can form triplex-like structures with messenger RNAs and halt the ribosomal machinery during the translation elongation. A 17-mer PNA that formed a PNA(2):mRNA complex with a purine-rich sequence located in the coding region of IGF-1R mRNA induced the synthesis of a truncated IGF-1R in vitro. This PNA down-regulated expression of the receptor by 70-80% in prostate cancer cells without affecting insulin receptor expression that exhibits high homology with IGF-1R. Inhibition occurs at the translational level, since the IGF-1R mRNA level measured by quantitative RT-PCR was not affected by PNA treatment. In addition, IGF-1R knockdown by PNA led to an attenuation of phosphorylation of downstream signaling pathways, PI3K/AKT and MAPK, involved in survival and mitogenesis and also to a decrease in cell transformation. Of the steric blockers tested, which included phosphorodiamidate morpholino oligomers and locked nucleic acids, PNA was unique in its ability to form triplex structures with mRNA and to arrest translation elongation.
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Affiliation(s)
- Sabine Lecosnier
- Centre National de la Recherche Scientifique, Muséum National d'Histoire Naturelle, Unité Mixte de Recherche 7196, Paris, France
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45
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Sípová H, Vaisocherová H, Stěpánek J, Homola J. A dual surface plasmon resonance assay for the determination of ribonuclease H activity. Biosens Bioelectron 2010; 26:1605-11. [PMID: 20829018 DOI: 10.1016/j.bios.2010.08.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2010] [Revised: 07/16/2010] [Accepted: 08/04/2010] [Indexed: 10/19/2022]
Abstract
There is a demand for efficient tools for the monitoring of RNase H activity. We report on a new assay which allows for simultaneous (1) real-time monitoring of RNase H activity and (2) detection of cleavage reaction products. The dual assay is implemented using a multichannel surface plasmon resonance (SPR) biosensor with two independently functionalized sensing areas in a single fluidic path. In the first sensing area the RNA cleavage by RNase H is monitored, while the products of the cleavage reaction are captured in the second sensing area with specific DNA probes. The assay was optimized with respect to AON concentration and temperature. A significant improvement was obtained with special chimeric probes, which contain RNA substrate for RNase H and a longer deoxyribonucleotide tail, which enhances the SPR signal. It has been shown that RNase H stabilizes the RNA:DNA hybrid duplex before the cleavage. The potential of the assay is demonstrated in the study in which the ability of natural and modified oligonucleotides to activate RNase H is examined.
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Affiliation(s)
- Hana Sípová
- Institute of Photonics and Electronics, Academy of Sciences of the Czech Republic, Chaberská 57, 182 51 Prague, Czech Republic
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46
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Zhou C, Liu Y, Andaloussi M, Badgujar N, Plashkevych O, Chattopadhyaya J. Fine tuning of electrostatics around the internucleotidic phosphate through incorporation of modified 2',4'-carbocyclic-LNAs and -ENAs leads to significant modulation of antisense properties. J Org Chem 2009; 74:118-34. [PMID: 19055352 DOI: 10.1021/jo8016742] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In the antisense (AS) and RNA interference (RNAi) technologies, the native single-stranded 2'-deoxyoligonucleotides (for AS) or double-stranded RNA (for RNAi) are chemically modified to bind to the target RNA in order to give improved downregulation of gene expression through inhibition of RNA translation. It is shown here how the fine adjustment of the electrostatic interaction by alteration of the substituents as well as their stereochemical environment around the internucleotidic phosphodiester moiety near the edge of the minor grove of the antisense oligonucleotides (AON)-RNA heteroduplex can lead to the modulation of the antisense properties. This was demonstrated through the synthesis of various modified carbocyclic-locked nucleic acids (LNAs) and -ethylene-bridged nucleic acids (ENAs) with hydroxyl and/or methyl substituents attached at the carbocyclic part and their integration into AONs by solid-phase DNA synthesis. The target affinity toward the complementary RNA and DNA, nuclease resistance, and RNase H elicitation by these modified AONs showed that both the nature of the modification (-OH versus -CH(3)) and their respective stereochemical orientations vis-a-vis vicinal phosphate play a very important role in modulating the AON properties. Whereas the affinity to the target RNA and the enzymatic stability of AONs were not favored by the hydrophobic and sterically bulky modifications in the center of the minor groove, their positioning at the edge of the minor groove near the phosphate linkage resulted in significantly improved nuclease resistance without loss of target affinity. On the other hand, hydrophilic modification, such as a hydroxyl group, close to the phosphate linkage made the internucleotidic phosphodiester especially nucleolytically unstable, and hence was not recommended. The substitutions on the carbocyclic moiety of the carba-LNA and -ENA did not affect significantly the choice of the cleavage sites of RNase H mediated RNA cleavage in the AON/RNA hybrid duplex, but the cleavage rate depended on the modification site in the AON sequence. If the original preferred cleavage site by RNase H was included in the 4-5nt stretch from the 3'-end of the modification site in the AON, decreased cleavage rate was observed. Upon screening of 52 modified AONs, containing 13 differently modified derivatives at C6' and C7' (or C8') of the carba-LNAs and -ENAs, two excellent modifications in the carba-LNA series were identified, which synergistically gave outstanding antisense properties such as the target RNA affinity, nuclease resistance, and RNase H activity and were deemed to be ideal candidates as potential antisense or siRNA therapeutic agents.
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Affiliation(s)
- Chuanzheng Zhou
- Department of Bioorganic Chemistry, Box 581, Biomedical Center, Uppsala University, SE-751 23 Uppsala, Sweden
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47
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Antisense makes sense in engineered regenerative medicine. Pharm Res 2008; 26:263-75. [PMID: 19015958 DOI: 10.1007/s11095-008-9772-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2008] [Accepted: 10/28/2008] [Indexed: 12/16/2022]
Abstract
The use of antisense strategies such as ribozymes, oligodeoxynucleotides (ODNs) and small interfering RNA (siRNA) in gene therapy, in conjunction with the use of stem cells and tissue engineering, has opened up possibilities in curing degenerative diseases and injuries to non-regenerating organs and tissues. With their unique ability to down-regulate or silence gene expression, antisense oligonucleotides are uniquely suited in turning down the production of pathogenic or undesirable proteins and cytokines. Here, we review the antisense strategies and their applications in regenerative medicine with a focus on their efficacies in promoting cell viability, regulating cell functionalities as well as shaping an optimal microenvironment for therapeutic purposes.
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48
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Watkins HA, Baker EN. Cloning, expression, purification and preliminary crystallographic analysis of the RNase HI domain of the Mycobacterium tuberculosis protein Rv2228c as a maltose-binding protein fusion. Acta Crystallogr Sect F Struct Biol Cryst Commun 2008; 64:746-9. [PMID: 18678948 PMCID: PMC2494979 DOI: 10.1107/s1744309108021118] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2008] [Accepted: 07/08/2008] [Indexed: 11/10/2022]
Abstract
The predicted ribonuclease (RNase) HI domain of the open reading frame Rv2228c from Mycobacterium tuberculosis has been cloned as a hexahistidine fusion and a maltose-binding protein (MBP) fusion. Expression was only observed for the MBP-fusion protein, which was purified using amylose affinity chromatography and gel filtration. The RNase HI domain could be cleaved from the MBP-fusion protein by factor Xa digestion, but was very unstable. In contrast, the fusion protein was stable, could be obtained in high yield and gave crystals which diffracted to 2.25 A resolution. The crystals belong to space group P2(1) and have unit-cell parameters a = 73.63, b = 101.38, c = 76.09 A, beta = 109.0 degrees. Two fusion-protein molecules of 57,417 Da were present in each asymmetric unit.
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Affiliation(s)
- Harriet A Watkins
- Maurice Wilkins Centre for Molecular Biodiscovery and School of Biological Sciences, 3A Symonds Street, Private Bag 92019, Auckland, New Zealand.
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49
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Cook PD. A brief history, status, and perspective of modified oligonucleotides for chemotherapeutic applications. ACTA ACUST UNITED AC 2008; Chapter 4:Unit 4.1. [PMID: 18428848 DOI: 10.1002/0471142700.nc0401s00] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The advent of rapid and efficient methods of oligonucleotide synthesis has allowed the design of modified oligonucleotides that are complementary to specific nucleotide sequences in mRNA targets. Such modified oligonucleotides can be used to disrupt the flow of genetic information from transcribed mRNAs to proteins. This antisense strategy has been used to develop therapeutic oligonucleotides against cancer and various infectious diseases in humans. This overview reports recent advances in the application of oligonucleotides as drug candidates, describes the relationship between oligonucleotide modifications and their therapeutic profiles, and provides general guidelines for enhancing oligonucleotide drug properties.
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Affiliation(s)
- P D Cook
- Isis Pharmaceuticals, Carlsbad, California, USA
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Brown D, Joy E, Greatorex J, Gait MJ, Lever AML. Steric block high affinity oligonucleotide analogues: a new tool for mapping RNA-protein binding sites. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2008; 27:196-212. [PMID: 18205073 DOI: 10.1080/15257770701795961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Steric-block ON analogues are efficient inhibitors of RNA-protein interaction and therefore have potential to probe RNA sequences for putative protein binding sites and to investigate mechanisms of protein binding. The packaging process of HIV-1 is highly specific involving an interaction between the Gag protein and a conserved sequence that is only present on genomic viral RNA. Using oligonucleotide probes we have confirmed that the terminal purine loop is the major Gag binding site on SL3 and that a secondary Gag binding site exists at an internal purine bulge. We also demonstrate direct binding of oligonucleotide to their binding sites and confirm this interaction does not alter global RNA conformation, making them highly specific, nondisruptive probes of RNA protein interactions.
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Affiliation(s)
- Douglas Brown
- Department of Medicine, University of Cambridge, Addenbrookes Hospital, Cambridge, United Kingdom
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