Articles de revues : « Oligonucleotidi antisenso »

1

Goddard, Layla R., Charlotte E. Mardle, Hassan Gneid, Ciara G. Ball, Darren M. Gowers, Helen S. Atkins, Louise E. Butt, Jonathan K. Watts, Helen A. Vincent et Anastasia J. Callaghan. « An Investigation into the Potential of Targeting Escherichia coli rne mRNA with Locked Nucleic Acid (LNA) Gapmers as an Antibacterial Strategy ». Molecules 26, n^o 11 (4 juin 2021) : 3414. http://dx.doi.org/10.3390/molecules26113414.

Texte intégral

Résumé :

The increase in antibacterial resistance is a serious challenge for both the health and defence sectors and there is a need for both novel antibacterial targets and antibacterial strategies. RNA degradation and ribonucleases, such as the essential endoribonuclease RNase E, encoded by the rne gene, are emerging as potential antibacterial targets while antisense oligonucleotides may provide alternative antibacterial strategies. As rne mRNA has not been previously targeted using an antisense approach, we decided to explore using antisense oligonucleotides to target the translation initiation region of the Escherichia coli rne mRNA. Antisense oligonucleotides were rationally designed and were synthesised as locked nucleic acid (LNA) gapmers to enable inhibition of rne mRNA translation through two mechanisms. Either LNA gapmer binding could sterically block translation and/or LNA gapmer binding could facilitate RNase H-mediated cleavage of the rne mRNA. This may prove to be an advantage over the majority of previous antibacterial antisense oligonucleotide approaches which used oligonucleotide chemistries that restrict the mode-of-action of the antisense oligonucleotide to steric blocking of translation. Using an electrophoretic mobility shift assay, we demonstrate that the LNA gapmers bind to the translation initiation region of E. coli rne mRNA. We then use a cell-free transcription translation reporter assay to show that this binding is capable of inhibiting translation. Finally, in an in vitro RNase H cleavage assay, the LNA gapmers facilitate RNase H-mediated mRNA cleavage. Although the challenges of antisense oligonucleotide delivery remain to be addressed, overall, this work lays the foundations for the development of a novel antibacterial strategy targeting rne mRNA with antisense oligonucleotides.

Styles APA, Harvard, Vancouver, ISO, etc.

2

Božič, Tim, Matja Zalar, Boris Rogelj, Janez Plavec et Primož Šket. « Structural Diversity of Sense and Antisense RNA Hexanucleotide Repeats Associated with ALS and FTLD ». Molecules 25, n^o 3 (25 janvier 2020) : 525. http://dx.doi.org/10.3390/molecules25030525.

Texte intégral

Résumé :

The hexanucleotide expansion GGGGCC located in C9orf72 gene represents the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal lobar dementia (FTLD). Since the discovery one of the non-exclusive mechanisms of expanded hexanucleotide G4C2 repeats involved in ALS and FTLD is RNA toxicity, which involves accumulation of pathological sense and antisense RNA transcripts. Formed RNA foci sequester RNA-binding proteins, causing their mislocalization and, thus, diminishing their biological function. Therefore, structures adopted by pathological RNA transcripts could have a key role in pathogenesis of ALS and FTLD. Utilizing NMR spectroscopy and complementary methods, we examined structures adopted by both guanine-rich sense and cytosine-rich antisense RNA oligonucleotides with four hexanucleotide repeats. While both oligonucleotides tend to form dimers and hairpins, the equilibrium of these structures differs with antisense oligonucleotide being more sensitive to changes in pH and sense oligonucleotide to temperature. In the presence of K+ ions, guanine-rich sense RNA oligonucleotide also adopts secondary structures called G-quadruplexes. Here, we also observed, for the first time, that antisense RNA oligonucleotide forms i-motifs under specific conditions. Moreover, simultaneous presence of sense and antisense RNA oligonucleotides promotes formation of heterodimer. Studied structural diversity of sense and antisense RNA transcripts not only further depicts the complex nature of neurodegenerative diseases but also reveals potential targets for drug design in treatment of ALS and FTLD.

Styles APA, Harvard, Vancouver, ISO, etc.

3

Dung, Tran Huu, Seung-Rok Lee, Suhk-Dong Han, Seon-Jeong Kim, Yeon-Mi Ju, Myong-Soo Kim et Hoon Yoo. « Chitosan-TPP Nanoparticle as a Release System of Antisense Oligonucleotide in the Oral Environment ». Journal of Nanoscience and Nanotechnology 7, n^o 11 (1 novembre 2007) : 3695–99. http://dx.doi.org/10.1166/jnn.2007.041.

Texte intégral

Résumé :

Antisense oligonucleotide loaded chitosan nanoparticles were prepared and the release of oligonucleotide from chitosan-TPP/oligonucleotide nanoparticles was investigated. Morphological property, zeta potential and particle size of the prepared chitosan/oligonucleotide nanoparticles were investigated using Field Emission-Scanning Electron Microscope (FE-SEM) and particle size analyzer. The interaction between chitosan and oligonucleotide was confirmed by using capillary zone electrophoresis (CZE), and the released oligonucleotides were determined by spectrophotometric method. Oligonucleotides formed the complexes with chitosan with a unique morphological property. The release of oligonucleotides from nanoparticles was dependent on loading methods and pH conditions. Chitosan/oligomer-TPP nanoparticles, which was prepared by adding TPP after the formation of chitosan/oligonucleotide complex, showed the lowest release percent of oligonucleotides with 41.3% at pH 7.0 among the loading methods. The percent release of oligonucleotide from oligonucleotide loaded chitosan nanoparticle at pH 10 was higher than the one in acidic condition (pH 5.0). The released oligonucleotides from chitosan/oligonucleotide nanoparticles were stable enough for 12 h under the 20% saliva solution. Our results suggest that the sustained release of oligonucleotide from chitosan nanoparticles may be suitable for the local therapeutic application in periodontal diseases.

Styles APA, Harvard, Vancouver, ISO, etc.

4

CHAKRABORTY, Rila, Dalia DASGUPTA, Samit ADHYA et Mukul K. BASU. « Cationic liposome-encapsulated antisense oligonucleotide mediates efficient killing of intracellular Leishmania ». Biochemical Journal 340, n^o 2 (25 mai 1999) : 393–96. http://dx.doi.org/10.1042/bj3400393.

Texte intégral

Résumé :

Antisense oligonucleotides have been considered as inhibitors of growth of intracellular parasites such as Leishmania, but only limited inhibition has been observed in vitro. We have encapsulated an antisense oligonucleotide, complementary to the Leishmania universal miniexon sequence, in cationic liposomes. Low concentrations (4 μM) of encapsulated oligonucleotides specifically reduced the amastigote burden within cultured macrophages by 80%. This result illustrates the importance of effective delivery for efficient antiparasitic activity of antisense oligonucleotides.

Styles APA, Harvard, Vancouver, ISO, etc.

5

Zhao, Q., X. Song, T. Waldschmidt, E. Fisher et AM Krieg. « Oligonucleotide uptake in human hematopoietic cells is increased in leukemia and is related to cellular activation ». Blood 88, n^o 5 (1 septembre 1996) : 1788–95. http://dx.doi.org/10.1182/blood.v88.5.1788.1788.

Texte intégral

Résumé :

Abstract The use of antisense oligonucleotides as tools for modulating gene expression represents a novel strategy for designing drugs to treat a variety of diseases. Several factors, including cellular uptake and internalization of the oligonucleotides, are important parameters in determining the effectiveness of antisense agents such as therapeutic drugs. We have studied oligonucleotides uptake in normal and leukemic human hematopoietic cells, such as peripheral blood, bone marrow (BM), and HL-60 cell line; and have found that, in normal human blood and BM, myeloid cells and B cells preferably took up more oligonucleotides than T cells. There was no marked difference in oligonucleotide uptake between CD4+ helper T cells and CD8+ cytolytic T cells. Leukemic cells had greater oligonucleotide uptake than their normal counterparts. Furthermore, oligonucleotide uptake was closely related to cell activation status and can be modulated by growth factors or inhibitors. These studies provide a basis for using oligonucleotides as therapeutic drugs both in vitro and in vivo.

Styles APA, Harvard, Vancouver, ISO, etc.

6

Zhao, Q., X. Song, T. Waldschmidt, E. Fisher et AM Krieg. « Oligonucleotide uptake in human hematopoietic cells is increased in leukemia and is related to cellular activation ». Blood 88, n^o 5 (1 septembre 1996) : 1788–95. http://dx.doi.org/10.1182/blood.v88.5.1788.bloodjournal8851788.

Texte intégral

Résumé :

The use of antisense oligonucleotides as tools for modulating gene expression represents a novel strategy for designing drugs to treat a variety of diseases. Several factors, including cellular uptake and internalization of the oligonucleotides, are important parameters in determining the effectiveness of antisense agents such as therapeutic drugs. We have studied oligonucleotides uptake in normal and leukemic human hematopoietic cells, such as peripheral blood, bone marrow (BM), and HL-60 cell line; and have found that, in normal human blood and BM, myeloid cells and B cells preferably took up more oligonucleotides than T cells. There was no marked difference in oligonucleotide uptake between CD4+ helper T cells and CD8+ cytolytic T cells. Leukemic cells had greater oligonucleotide uptake than their normal counterparts. Furthermore, oligonucleotide uptake was closely related to cell activation status and can be modulated by growth factors or inhibitors. These studies provide a basis for using oligonucleotides as therapeutic drugs both in vitro and in vivo.

Styles APA, Harvard, Vancouver, ISO, etc.

7

Studzińska, Sylwia, Ewelina Zawadzka, Szymon Bocian et Michał Szumski. « Synthesis and application of stationary phase for DNA-affinity chromatographic analysis of unmodified and antisense oligonucleotide ». Analytical and Bioanalytical Chemistry 413, n^o 20 (24 juin 2021) : 5109–19. http://dx.doi.org/10.1007/s00216-021-03473-7.

Texte intégral

Résumé :

AbstractThe goal of the research was the synthesis and application of an oligonucleotide immobilized stationary phase for the analysis of unmodified and antisense oligonucleotides. The method for attaching these molecules to aminopropyl silica modified with pentanedioic acid was developed. Each step of the synthesis was carefully controlled with the application of spectroscopic, elemental, and chromatographic analyses. The oligonucleotide-based stationary phase was applied for the retention studies. Unmodified oligonucleotides of different complementarity to the molecule attached as a stationary phase, as well as antisense oligonucleotides, were tested. The comparative study upon complex optimization of oligonucleotide analysis in different liquid chromatography modes was performed. Results have shown that this stationary phase may be applied for oligonucleotide analysis in hydrophilic interaction liquid chromatography and ion exchange chromatography, but no unique sequence-based selectivity was obtained. Contrary results were observed for affinity chromatography, which allowed for specific separation of the complementary strands based on hydrogen bonding and stacking interactions, where the temperature was the main factor influencing the selectivity of the separation. Furthermore, the oligonucleotide-based stationary phase may be applied for comparative antisense oligonucleotide hybridization studies to a specific RNA sequence. All of the results have shown that affinity chromatography with oligonucleotide-based stationary phases is a powerful technique for the specific base recognition of polynucleotides. Graphical abstract

Styles APA, Harvard, Vancouver, ISO, etc.

8

Pandiri, Kavya, Mohammed Abdul Samad, Nadeem Abbas Gulamus et Hajera Khanam. « Medicinal Applications of Antisense Oligonucleotides : A Review ». INTERNATIONAL JOURNAL OF APPLIED PHARMACEUTICAL SCIENCES AND RESEARCH 5, n^o 02 (1 avril 2020) : 30–36. http://dx.doi.org/10.21477/ijapsr.5.2.2.

Texte intégral

Résumé :

Antisense technology has emerged as a fast and conceivably high-throughput method for repressing genes due to advancement in knowledge about DNA and RNA physiology. The limitations of antisense oligonucleotide therapy in delivery strategies have been overcome in recent years. Antisense oligonucleotide treatment was effectively applied towards targeting a wide range of therapeutic areas. With ongoing approvals of antisense oligonucleotides, there is an expanding enthusiasm for increasing the utilization of these compounds for curing various infections. This short survey gives a far-reaching comprehension of applications of antisense technology, how they can be utilized therapeutically, and current endeavors to grow new antisense oligonucleotide treatments that will add a forthcoming therapeutic approach for the treatment of various diseases.

Styles APA, Harvard, Vancouver, ISO, etc.

9

Yamamoto, T., R. P. Moerschell, L. P. Wakem, S. Komar-Panicucci et F. Sherman. « Strand-specificity in the transformation of yeast with synthetic oligonucleotides. » Genetics 131, n^o 4 (1 août 1992) : 811–19. http://dx.doi.org/10.1093/genetics/131.4.811.

Texte intégral

Résumé :

Abstract Cyc1 mutants of the yeast Saccharomyces cerevisiae were directly transformed with both sense and antisense oligonucleotides to examine the involvement of the two genomic DNA strands in transformation. Sense oligonucleotides yielded approximately 20-fold more transformants than antisense oligonucleotides. This differential effect was observed with oligonucleotides designed to make alterations at six different sites along the gene and was independent of the oligonucleotide sequence and length, number of mismatches and the host strain. Competition studies showed that antisense oligonucleotides did not inhibit transformation. Although the mechanism for this strand specificity is unknown, this difference was maintained even when CYC1 transcription was diminished to approximately 2% of the normal level.

Styles APA, Harvard, Vancouver, ISO, etc.

10

Tanaka, T., C. C. Chu et W. E. Paul. « An antisense oligonucleotide complementary to a sequence in I gamma 2b increases gamma 2b germline transcripts, stimulates B cell DNA synthesis, and inhibits immunoglobulin secretion. » Journal of Experimental Medicine 175, n^o 2 (1 février 1992) : 597–607. http://dx.doi.org/10.1084/jem.175.2.597.

Texte intégral

Résumé :

An antisense phosphorothioate (S)-oligonucleotide to a sequence in the intervening (I) region of the gamma 2b immunoglobulin (Ig) heavy chain gene inhibits Ig secretion by B cells stimulated with lipopolysaccharide (LPS) or LPS plus interleukin 4. It is also a striking stimulant of DNA synthesis by resting B cells. The antisense S-oligonucleotide causes a 10-20-fold increase in the expression of the gamma 2b germline transcript. Among mutants of the antisense S-oligonucleotide, some show all the effects whereas others are inactive. A similar hierarchy exists in the quantitative biological activities of mutant S-oligonucleotides and in their capacity to hybridize to the sense oligonucleotide, strongly suggesting that an I gamma 2b sequence in the RNA transcript or in the noncoding strand of the DNA is the target of the antisense S-oligonucleotide. The possible relationship of the overexpression of the germline gamma 2b transcript to the biological functions of the I gamma 2b antisense S-oligonucleotide is discussed.

Styles APA, Harvard, Vancouver, ISO, etc.

11

Leung-Hagesteijn, C. Y., K. Milankov, M. Michalak, J. Wilkins et S. Dedhar. « Cell attachment to extracellular matrix substrates is inhibited upon downregulation of expression of calreticulin, an intracellular integrin alpha-subunit-binding protein ». Journal of Cell Science 107, n^o 3 (1 mars 1994) : 589–600. http://dx.doi.org/10.1242/jcs.107.3.589.

Texte intégral

Résumé :

We have demonstrated recently that calreticulin, an intracellular calcium-binding protein, can interact with the alpha-subunits of integrin receptors via the highly conserved KXGFFKR amino acid sequence present in the cytoplasmic domains of all integrin alpha-subunits (Rojiani et al. (1991) Biochemistry 30, 9859–9866). Here we demonstrate that calreticulin can be co-localized by immunofluorescence as well as co-purified with integrins, that recombinant calreticulin can also interact with integrins, and that the interaction occurs predominantly via the N-domain of calreticulin, to a much lesser extent with the C-domain, but not at all with the proline-rich P-domain. To demonstrate a physiological role for the interaction of calreticulin with integrins, calreticulin expression was downregulated by treating cells with antisense oligonucleotides designed to inhibit the initiation of translation of calreticulin. Antisense oligonucleotides, but not sense or non-sense oligonucleotides, inhibited attachment and spreading of cells cultured in the presence of fetal bovine serum, and also of cells plated on individual extracellular matrix substrates in the absence of serum. The antisense oligonucleotide inhibited cell proliferation of anchorage-dependent cells slightly, but there was no effect on cell viability. The effect on cell attachment was similar to that achieved by treating cells with an antisense oligonucleotide designed to inhibit translation of the integrin alpha 3 subunit, which resulted in the inhibition of cell attachment to alpha 3 beta 1-specific substrates. The effect of the antisense calreticulin oligonucleotide on cell attachment was demonstrated to be integrin-mediated since antisense calreticulin treatment of Jurkat cells abrogated the stimulation of collagen cell attachment achieved by attachment-stimulating signalling anti-alpha 2 (JBS2) and anti-beta 1 (21C8) antibodies. The oligonucleotides did not affect the rate of cell proliferation of these cells. These results demonstrate a fundamental role of calreticulin in cell-extracellular matrix interactions.

Styles APA, Harvard, Vancouver, ISO, etc.

12

Bennett, C. F., T. P. Condon, S. Grimm, H. Chan et M. Y. Chiang. « Inhibition of endothelial cell adhesion molecule expression with antisense oligonucleotides. » Journal of Immunology 152, n^o 7 (1 avril 1994) : 3530–40. http://dx.doi.org/10.4049/jimmunol.152.7.3530.

Texte intégral

Résumé :

Abstract In response to inflammatory stimuli, expression of a group of proteins that bind circulating leukocytes (endothelial-leukocyte adhesion molecules) are induced on the luminal surface of vascular endothelium. A series of phosphorothioate oligonucleotides 18 to 21 bases in length were designed and synthesized to hybridize selectively to the mRNA, which encodes three such endothelial-leukocyte adhesion molecules; human intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin. Antisense oligonucleotides were identified that selectively inhibited ICAM-1, VCAM-1, and E-selectin expression in HUVEC. Oligonucleotides that hybridized to the 3'-untranslated region of either ICAM-1, VCAM-1, or E-selectin mRNAs promoted a selective reduction in the respective mRNA levels. In contrast, oligonucleotides that hybridized to 5'-untranslated sequences did not significantly reduce target mRNA levels, although they did promote a reduction in protein expression. With the use of flow cytometry to measure cell surface expression, ICAM-1 and E-selectin were selectively inhibited by their respective antisense oligonucleotide. At low concentrations of oligonucleotides, only VCAM-1 antisense oligonucleotides inhibited VCAM-1 expression. However, at an oligonucleotide concentration of 50 nM or greater, phosphorothioate oligonucleotides not predicted to hybridize to VCAM-1 mRNA also reduced VCAM-1 expression. The sequence-independent inhibition of VCAM-1 expression by phosphorothioate oligonucleotides could be the result of a perturbation in the transcriptional regulation of the VCAM-1 gene. ICAM-1, VCAM-1, and E-selectin antisense oligonucleotides reduced adhesion of HL-60 cells to TNF-activated HUVEC. These data demonstrate that phosphorothioate oligonucleotides are capable of selectively inhibiting the expression of ICAM-1, VCAM-1, and E-selectin in HUVEC.

Styles APA, Harvard, Vancouver, ISO, etc.

13

Aoki, Yoshitsugu, Tetsuya Nagata et Shin’ichi Takeda. « New Approach for Antisense Oligonucleotide-Mediated Exon Skipping in Duchenne Muscular Dystrophy ». Journal of Advanced Computational Intelligence and Intelligent Informatics 16, n^o 4 (20 juin 2012) : 521–26. http://dx.doi.org/10.20965/jaciii.2012.p0521.

Texte intégral

Résumé :

Duchenne Muscular Dystrophy (DMD) is a lethalmuscle disorder characterized by mutations in the DMD gene. These mutations primarily disrupt the reading frame, resulting in the absence of functional dystrophin protein. Exon skipping, which involves the use of antisense oligonucleotides is a promising therapeutic approach for DMD, and clinical trials on exon skipping are currently underway in DMD patients. Recently, stable and less-toxic antisense oligonucleotides with higher efficacy have been developed in mouse and dog models of DMD. This review highlights a new approach for antisense oligonucleotide-based therapeutics for DMD, particularly for exon skipping-based methods.

Styles APA, Harvard, Vancouver, ISO, etc.

14

Juliano, Rudolph L. « Chemical Manipulation of the Endosome Trafficking Machinery : Implications for Oligonucleotide Delivery ». Biomedicines 9, n^o 5 (5 mai 2021) : 512. http://dx.doi.org/10.3390/biomedicines9050512.

Texte intégral

Résumé :

Antisense oligonucleotides (ASOs), siRNA and splice switching oligonucleotides (SSOs) all have immense potential as therapeutic agents, potential that is now being validated as oligonucleotides enter the clinic. However, progress in oligonucleotide-based therapeutics has been limited by the difficulty in delivering these complex molecules to their sites of action in the cytosol or nucleus of cells within specific tissues. There are two aspects to the delivery problem. The first is that most types of oligonucleotides have poor uptake into non-hepatic tissues. The second is that much of the oligonucleotide that is taken up by cells is entrapped in endosomes where it is pharmacologically inert. It has become increasingly recognized that endosomal trapping is a key constraint on oligonucleotide therapeutics. Thus, many approaches have been devised to address this problem, primarily ones based on various nanoparticle technologies. However, recently an alternative approach has emerged that employs small molecules to manipulate intracellular trafficking processes so as to enhance oligonucleotide actions. This review presents the current status of this chemical biology approach to oligonucleotide delivery and seeks to point out possible paths for future development.

Styles APA, Harvard, Vancouver, ISO, etc.

15

Zhang, R., Z. Lu, X. Zhang, H. Zhao, R. B. Diasio, T. Liu, Z. Jiang et S. Agrawal. « In vivo stability and disposition of a self-stabilized oligodeoxynucleotide phosphorothioate in rats ». Clinical Chemistry 41, n^o 6 (1 juin 1995) : 836–43. http://dx.doi.org/10.1093/clinchem/41.6.836.

Texte intégral

Résumé :

Abstract The use of antisense oligonucleotides represents a novel, genetically based therapy. The biostability and pharmacokinetics of a 33-mer self-stabilized oligodeoxynucleotide with significant anti-HIV activity was determined in rats after intravenous administration of [35S]oligodeoxynucleotide. Plasma disappearance of the labeled oligodeoxynucleotide could be described by a two-compartment model, with half-lives of 0.54 and 41.44 h. The oligodeoxynucleotide in plasma remained mainly intact. Urinary excretion represented the major elimination pathway, with approximately 27% of the administered dose excreted within 24 h and 57% over 240 h. The majority of radioactivity in urine was attached to degradative products. Fecal excretion was a minor elimination pathway. A wide tissue distribution of the oligonucleotide was observed, with the majority of radioactivity in most tissues being intact. Compared with other linear oligonucleotide phosphorothioates, the self-stabilized oligonucleotide was more stable in vivo, which may be important in development of antisense oligonucleotides as therapeutic agents.

Styles APA, Harvard, Vancouver, ISO, etc.

16

Lesnikowski, Zbigniew J., Marzena Przepiórkiewicz, Yutaka Tamura, Hideko Kaji et Eric Wickstrom. « P-Chiral Oligonucleotides. Effect of Configuration at Phosphorus on Transport of Tetra(thymidine Methylphosphonate)s Across Organic Liquid Membrane ». Collection of Czechoslovak Chemical Communications 66, n^o 6 (2001) : 912–22. http://dx.doi.org/10.1135/cccc20010912.

Texte intégral

Résumé :

The stereodependent transport of a P-stereoregular oligonucleotide through a model organic liquid membrane is described. The electroneutral tetra(thymidine methylphosphonate) was used as oligonucleotide. The transportability increased in the order: all-RP > random distribution of P-diastereomers > all-SP. These findings extend our knowledge of the physicochemical properties of single-stranded methylphosphonate oligonucleotides in solution, and might facilitate cellular uptake of future antisense oligonucleotide drugs.

Styles APA, Harvard, Vancouver, ISO, etc.

17

Epple, Sven, Cameron Thorpe, Ysobel R. Baker, Afaf H. El-Sagheer et Tom Brown. « Consecutive 5′- and 3′-amide linkages stabilise antisense oligonucleotides and elicit an efficient RNase H response ». Chemical Communications 56, n^o 41 (2020) : 5496–99. http://dx.doi.org/10.1039/d0cc00444h.

Texte intégral

Résumé :

The combination of amide coupling with standard oligonucleotide synthesis enables assembly of reduced charge chimeric gapmer antisense oligonucleotides that trigger an efficient RNase H response while improving serum lifetime and cellular uptake.

Styles APA, Harvard, Vancouver, ISO, etc.

18

Yuan, Ahu, Yiqiao Hu et Xin Ming. « Dendrimer conjugates for light-activated delivery of antisense oligonucleotides ». RSC Advances 5, n^o 44 (2015) : 35195–200. http://dx.doi.org/10.1039/c5ra04091d.

Texte intégral

Résumé :

PAMAM dendrimer conjugates are used to co-deliver oligonucleotides and photosensitizers to cancer cells. After photo-irradiation, substantial reporter eGFP expression is produced by functional delivery of a model oligonucleotide.

Styles APA, Harvard, Vancouver, ISO, etc.

19

Howell, B., H. Deacon et L. Cassimeris. « Decreasing oncoprotein 18/stathmin levels reduces microtubule catastrophes and increases microtubule polymer in vivo ». Journal of Cell Science 112, n^o 21 (1 novembre 1999) : 3713–22. http://dx.doi.org/10.1242/jcs.112.21.3713.

Texte intégral

Résumé :

Oncoprotein 18/stathmin (Op18) has been identified recently as a protein which destabilizes microtubules. To characterize the function of Op18 in living cells, we used microinjection of anti-Op18 antibodies or antisense oligonucleotides to block either Op18 activity or expression in interphase newt lung cells. Anti-tubulin staining of cells microinjected with anti-Op18 and fixed 1–2 hours after injection showed an increase in total microtubule polymer. In contrast, microinjection of either non-immune IgG or anti-Op18 preincubated with bacterially-expressed Op18 had little effect on microtubule polymer level. Cells treated with Op18 antisense oligonucleotides for 4 days had (greater than or equal to)50% reduced levels of Op18 with no change in the soluble tubulin level. Measurement of MT polymer level in untreated, antisense or nonsense oligonucleotide treated cells demonstrated that reduced Op18 levels resulted in a 2.5-fold increase in microtubule polymer. Next, the assembly dynamics of individual microtubules at the peripheral regions of living cells were examined using video-enhanced contrast DIC microscopy. Microinjection of antibodies against oncoprotein 18 resulted in a 2.2-fold reduction in catastrophe frequency and a slight reduction in plus end elongation velocity compared to uninjected cells or cells microinjected with non-immune IgG. Preincubation of anti-Op18 antibody with recombinant Op18 greatly diminished the effects of the antibody. Similarly, treatment of cells with antisense oligonucleotides reduced catastrophes 2.5- to 3-fold compared to nonsense oligonucleotide treated or untreated cells. The other parameters of dynamic instability were unchanged after reducing Op18 with antisense oligonucleotides. These studies are consistent with Op18 functioning to regulate microtubule catastrophes during interphase in vivo.

Styles APA, Harvard, Vancouver, ISO, etc.

20

SIPES, TAMARA B., et SUSAN M. FREIER. « PREDICTION OF ANTISENSE OLIGONUCLEOTIDE EFFICACY USING AGGREGATE MOTIFS ». Journal of Bioinformatics and Computational Biology 06, n^o 05 (octobre 2008) : 919–32. http://dx.doi.org/10.1142/s0219720008003795.

Texte intégral

Résumé :

Antisense oligonucleotide technology allows the targeted reduction of mRNA expression through the in vitro application of short (~20 nt) DNA molecules. Oligonucleotides are valuable both in the study of gene regulation and for having potential therapeutic effects. In theory, a base sequence complementary to a region of the transcript would hybridize to its mRNA target. Nevertheless, in practice some complementary antisense oligonucleotides are more active and more potent than others in suppressing specific gene expression. We present a novel computational approach to modeling oligonucleotide efficacy that uses aggregate motifs, which are flexible tetramotifs that expand the predictive ability of the data descriptors and the attribute space. We also demonstrate our findings on the largest dataset yet reported in the literature. It was shown that the prediction accuracy was significantly enhanced, offering more than eightfold improvement compared to the traditional methods.

Styles APA, Harvard, Vancouver, ISO, etc.

21

He, Xiao-Yang, Jing Wang, Dan-Dan Lu et Sheng-Qi Wang. « Synthesis and Antisense Properties of 2′β-F-Arabinouridine Modified Oligonucleotides with 4′-C-OMe Substituent ». Molecules 23, n^o 9 (17 septembre 2018) : 2374. http://dx.doi.org/10.3390/molecules23092374.

Texte intégral

Résumé :

A novel 2′-F,4′-C-OMe–arabinouridine (araU) was successfully synthesized and introduced into oligonucleotides. The oligonucleotide containing 2′-F,4′-C-OMe–araU exhibited improved nuclease resistance and RNA hybridizing selective ability relative to 2′-F–araU. In particular, when 2′-F,4′-C-OMe–araU inserted into C–H⋯F–C bonding-favorable 5′–uridine–purine–3′ steps, the modified oligonucleotide showed remarkable binding affinity and selectivity to RNA complements. Thus, 2′-F,4′-C-OMe–araU has valuable antisense properties and can be used as novel chemical modification for antisense therapeutic strategy.

Styles APA, Harvard, Vancouver, ISO, etc.

22

Oberemok, Volodymyr V., Oksana A. Andreeva et Edie E. Alieva. « DNA Oligonucleotides as Antivirals and Vaccine Constituents against SARS Coronaviruses : A Prospective Tool for Immune System Tuning ». International Journal of Molecular Sciences 24, n^o 2 (13 janvier 2023) : 1553. http://dx.doi.org/10.3390/ijms24021553.

Texte intégral

Résumé :

The SARS-CoV-2 pandemic has demonstrated the need to create highly effective antivirals and vaccines against various RNA viruses, including SARS coronaviruses. This paper provides a short review of innovative strategies in the development of antivirals and vaccines against SARS coronaviruses, with a focus on antisense antivirals, oligonucleotide adjuvants in vaccines, and oligonucleotide vaccines. Well-developed viral genomic databases create new opportunities for the development of innovative vaccines and antivirals using a post-genomic platform. The most effective vaccines against SARS coronaviruses are those able to form highly effective memory cells for both humoral and cellular immunity. The most effective antivirals need to efficiently stop viral replication without side effects. Oligonucleotide antivirals and vaccines can resist the rapidly changing genomic sequences of SARS coronaviruses using conserved regions of their genomes to generate a long-term immune response. Oligonucleotides have been used as excellent adjuvants for decades, and increasing data show that oligonucleotides could serve as antisense antivirals and antigens in vaccine formulations, becoming a prospective tool for immune system tuning.

Styles APA, Harvard, Vancouver, ISO, etc.

23

Patutina, Olga A., Svetlana K. Gaponova (Miroshnichenko), Aleksandra V. Sen’kova, Innokenty A. Savin, Daniil V. Gladkikh, Ekaterine A. Burakova, Alesya A. Fokina et al. « Mesyl phosphoramidate backbone modified antisense oligonucleotides targeting miR-21 with enhanced in vivo therapeutic potency ». Proceedings of the National Academy of Sciences 117, n^o 51 (7 décembre 2020) : 32370–79. http://dx.doi.org/10.1073/pnas.2016158117.

Texte intégral

Résumé :

The design of modified oligonucleotides that combine in one molecule several therapeutically beneficial properties still poses a major challenge. Recently a new type of modified mesyl phosphoramidate (or µ-) oligonucleotide was described that demonstrates high affinity to RNA, exceptional nuclease resistance, efficient recruitment of RNase H, and potent inhibition of key carcinogenesis processes in vitro. Herein, using a xenograft mouse tumor model, it was demonstrated that microRNA miR-21–targeted µ-oligonucleotides administered in complex with folate-containing liposomes dramatically inhibit primary tumor growth via long-term down-regulation of miR-21 in tumors and increase in biosynthesis of miR-21–regulated tumor suppressor proteins. This antitumoral effect is superior to the effect of the corresponding phosphorothioate. Peritumoral administration of µ-oligonucleotide results in its rapid distribution and efficient accumulation in the tumor. Blood biochemistry and morphometric studies of internal organs revealed no pronounced toxicity of µ-oligonucleotides. This new oligonucleotide class provides a powerful tool for antisense technology.

Styles APA, Harvard, Vancouver, ISO, etc.

24

Nair, S. K., D. Snyder et E. Gilboa. « Cells treated with TAP-2 antisense oligonucleotides are potent antigen-presenting cells in vitro and in vivo. » Journal of Immunology 156, n^o 5 (1 mars 1996) : 1772–80. http://dx.doi.org/10.4049/jimmunol.156.5.1772.

Texte intégral

Résumé :

Abstract Treatment of RMA and EL4 cells or freshly isolated splenocytes with antisense (AS) oligonucleotides directed against the TAP-2 gene recreates the phenotype seen in cells that are genetically deficient in TAP function. Cells incubated with AS oligonucleotides exhibit reduced MHC class I expression on the cell surface, which can be increased by incubating the oligonucleotide-treated cells at 28 degrees C or by adding MHC haplotype-matched peptides to the culture medium. RMA cells or splenocytes treated with AS oligonucleotides and incubated with peptide were highly effective in generating primary CTL responses in vitro. The bulk of the AS oligonucleotide-responsive and CTL-inducing cells resided in the adherent fraction of splenocytes. Moreover, TAP-2 AS oligonucleotide-treated adherent splenocytes pulsed with OVA peptide elicited potent OVA-specific CTL responses in vivo and provided effective protection from challenge with tumor cells expressing the corresponding Ag. AS oligonucleotide technology provides a simple approach to develop broadly applicable methods for generating potent APC to study TAP function in normal cells and to identify other gene products involved in MHC class I presentation.

Styles APA, Harvard, Vancouver, ISO, etc.

25

SHARPE, CLAIRE C., MARK E. C. DOCKRELL, MAZHAR I. NOOR, BRETT P. MONIA et BRUCE M. HENDRY. « Role of Ras Isoforms in the Stimulated Proliferation of Human Renal Fibroblasts in Primary Culture ». Journal of the American Society of Nephrology 11, n^o 9 (septembre 2000) : 1600–1606. http://dx.doi.org/10.1681/asn.v1191600.

Texte intégral

Résumé :

Abstract. The proliferation of renal fibroblasts is implicated in the pathophysiologic processes of renal fibrosis. Many of the growth factors involved in proliferation are known to activate intracellular signaling pathways that converge on Ras monomeric GTPases. Although three ras family genes exist, their functional specificity is not yet known. Using antisense oligonucleotides, a role for Kirsten (Ki)-Ras in the stimulated proliferation of a primate renal fibroblast cell line was previously demonstrated. This study examines Ras in primary cultures of adult human renal fibroblasts. Using reverse transcription-PCR, mRNA for Harvey (Ha)-ras, Ki(4B)-ras, and neural (N)-ras, but not Ki(4A)-ras, were detected. Antisense oligonucleotides targeting Ha-, Ki-, and N-ras mRNA, which were used for liposomal transfection at 100 to 200 nM, were demonstrated to be active and isoform-specific in quantitative reverse transcription-PCR assays. Cellular Ras protein levels, as estimated using isoform-specific monoclonal antibodies, indicated that Ki-Ras was the predominantly expressed isoform (>95% of total Ras protein) under both serum-containing and serum-free conditions, with N- and Ha-Ras being detected in small amounts. Consistent with this finding, the antisense oligonucleotide directed against Ki-Ras reduced total cellular Ras levels by >70%, whereas Ha-Ras, N-Ras, and control oligonucleotides had no significant effect. Proliferation of oligonucleotide-transfected cells was measured using epidermal growth factor (EGF) and serum stimulation. The Ki-Ras oligonucleotide at 100 nM reduced serum-stimulated proliferation by >50% and EGF-stimulated proliferation by 25%, compared with data obtained with the control oligonucleotide (P < 0.01). The N-Ras oligonucleotide was not active, compared with the control oligonucleotide. The Ha-Ras oligonucleotide was not significantly active at 100 nM but reduced serum-stimulated proliferation by 13% and EGF-stimulated growth by 40% at 200 nM (P < 0.01). These results demonstrate that Ki-Ras(4B) is the predominantly expressed Ras isoform in human renal fibroblasts in primary culture and is important for both serum- and EGF-stimulated proliferation. Ha-Ras appears to be expressed at low levels but may also play a distinct role in stimulated proliferation.

Styles APA, Harvard, Vancouver, ISO, etc.

26

White, D. G., K. Maneewannakul, E. von Hofe, M. Zillman, W. Eisenberg, A. K. Field et S. B. Levy. « Inhibition of the multiple antibiotic resistance (mar) operon in Escherichia coli by antisense DNA analogs. » Antimicrobial Agents and Chemotherapy 41, n^o 12 (décembre 1997) : 2699–704. http://dx.doi.org/10.1128/aac.41.12.2699.

Texte intégral

Résumé :

The multiple antibiotic resistance operon (marORAB) in Escherichia coli controls intrinsic susceptibility and resistance to multiple, structurally different antibiotics and other noxious agents. A plasmid construct with marA cloned in the antisense direction reduced LacZ expression from a constitutively expressed marA::lacZ translational fusion and inhibited the induced expression of LacZ in cells bearing the wild-type repressed fusion. The marA antisense construction also decreased the multiple antibiotic resistance of a Mar mutant. Two antisense phosphorothioate oligonucleotides, one targeted to marO and the other targeted to marA of the mar operon, introduced by heat shock or electroporation reduced LacZ expression in the strain having the marA::lacZ fusion. One antisense oligonucleotide, tested against a Mar mutant of E. coli ML308-225, increased the bactericidal activity of norfloxacin. These studies demonstrate the efficacy of exogenously delivered antisense oligonucleotides targeted to the marRAB operon in inhibiting expression of this chromosomal regulatory locus.

Styles APA, Harvard, Vancouver, ISO, etc.

27

Allinquant, B., P. Hantraye, P. Mailleux, K. Moya, C. Bouillot et A. Prochiantz. « Downregulation of amyloid precursor protein inhibits neurite outgrowth in vitro. » Journal of Cell Biology 128, n^o 5 (1 mars 1995) : 919–27. http://dx.doi.org/10.1083/jcb.128.5.919.

Texte intégral

Résumé :

The amyloid precursor protein (APP) is a transmembrane protein expressed in several cell types. In the nervous system, APP is expressed by glial and neuronal cells, and several lines of evidence suggest that it plays a role in normal and pathological phenomena. To address the question of the actual function of APP in normal developing neurons, we undertook a study aimed at blocking APP expression using antisense oligonucleotides. Oligonucleotide internalization was achieved by linking them to a vector peptide that translocates through biological membranes. This original technique, which is very efficient and gives direct access to the cell cytosol and nucleus, allowed us to work with extracellular oligonucleotide concentrations between 40 and 200 nM. Internalization of antisense oligonucleotides overlapping the origin of translation resulted in a marked but transient decrease in APP neosynthesis that was not observed with the vector peptide alone, or with sense oligonucleotides. Although transient, the decrease in APP neosynthesis was sufficient to provoke a distinct decrease in axon and dendrite outgrowth by embryonic cortical neurons developing in vitro. The latter decrease was not accompanied by changes in the spreading of the cell bodies. A single exposure to coupled antisense oligonucleotides at the onset of the culture was sufficient to produce significant morphological effects 6, 18, and 24 h later, but by 42 h, there were no remaining significant morphologic changes. This report thus demonstrates that amyloid precursor protein plays an important function in the morphological differentiation of cortical neurons in primary culture.

Styles APA, Harvard, Vancouver, ISO, etc.

28

Watts, Jonathan K., et Masad J. Damha. « 2′F-Arabinonucleic acids (2′F-ANA) — History, properties, and new frontiers ». Canadian Journal of Chemistry 86, n^o 7 (1 juillet 2008) : 641–56. http://dx.doi.org/10.1139/v08-049.

Texte intégral

Résumé :

The development of arabinonucleosides and oligoarabinonucleotides is described, focusing especially on 2′-deoxy-2′-fluoroarabinonucleosides (araF-N) and -oligonucleotides (2'F-ANA). In addition to their chemical and enzymatic synthesis, we discuss various properties of 2′F-ANA: hydrolytic stability (to nucleases, acids, and bases), binding affinity to complementary strands, structure and conformation, and optimization of RNase H activity. We also discuss the use of 2′F-ANA in gene-silencing approaches (antisense, siRNA), and in the stabilization of higher-order structures (such as triplexes and quadruplexes) including aptamers. Finally, we examine several other oligonucleotide derivatives based on 2′F-ANA and look ahead to the future of 2′-fluoroarabinonucleosides and -oligonucleotides.Key words: arabinonucleic acids, 2′F-ANA, antisense oligonucleotides, siRNA, modified oligonucleotides.

Styles APA, Harvard, Vancouver, ISO, etc.

29

Sheffield, LG. « Epidermal growth factor as an autocrine modulator of stress response in mammary epithelial cells ». Journal of Endocrinology 159, n^o 1 (1 octobre 1998) : 111–16. http://dx.doi.org/10.1677/joe.0.1590111.

Texte intégral

Résumé :

Mouse mammary epithelial cells (NMuMG line) were heat shocked at 42 degreesC for up to 2 h, with continuous culture at 37 degreesC used as controls. EGF mRNA expression, determined by Northern blot hybridization, was increased 4- to 5-fold in heat-shocked cells compared with controls. Heat shock also induced accumulation of EGF immunoreactive protein in both media and cell lysates of NMuMG cells. Oligonucleotides antisense to the EGF mRNA blocked the accumulation of EGF protein, while sense controls were without effect. Antisense oligonucleotide concentrations that inhibited EGF production by NMuMG cells during heat shock dramatically reduced the ability of cells to survive heat shock, while sense oligonucleotide did not affect cell survival. The antisense oligonucleotide inhibition of cell survival was reversed by adding EGF during the heat shock period. Thus the production of EGF or EGF-like peptides during periods of cellular stress may be an important survival mechanism in mammary epithelium.

Styles APA, Harvard, Vancouver, ISO, etc.

30

Yu, Chien-Hung, Mathieu H. M. Noteborn et René C. L. Olsthoorn. « Stimulation of ribosomal frameshifting by antisense LNA ». Nucleic Acids Research 38, n^o 22 (6 août 2010) : 8277–83. http://dx.doi.org/10.1093/nar/gkq650.

Texte intégral

Résumé :

Abstract Programmed ribosomal frameshifting is a translational recoding mechanism commonly used by RNA viruses to express two or more proteins from a single mRNA at a fixed ratio. An essential element in this process is the presence of an RNA secondary structure, such as a pseudoknot or a hairpin, located downstream of the slippery sequence. Here, we have tested the efficiency of RNA oligonucleotides annealing downstream of the slippery sequence to induce frameshifting in vitro. Maximal frameshifting was observed with oligonucleotides of 12–18 nt. Antisense oligonucleotides bearing locked nucleid acid (LNA) modifications also proved to be efficient frameshift-stimulators in contrast to DNA oligonucleotides. The number, sequence and location of LNA bases in an otherwise DNA oligonucleotide have to be carefully manipulated to obtain optimal levels of frameshifting. Our data favor a model in which RNA stability at the entrance of the ribosomal tunnel is the major determinant of stimulating slippage rather than a specific three-dimensional structure of the stimulating RNA element.

Styles APA, Harvard, Vancouver, ISO, etc.

31

Kobylańska, A., E. Pluskota, M. Swiatkowska, M. Wójcik, A. Cierniewska-Cieślak, A. Krakowiak, M. Boczkowska et al. « Inhibition of plasminogen activator inhibitor release in endothelial cell cultures by antisense oligodeoxyribonucleotides with a 5'-end lipophilic modification. » Acta Biochimica Polonica 46, n^o 3 (30 septembre 1999) : 679–91. http://dx.doi.org/10.18388/abp.1999_4140.

Texte intégral

Résumé :

A series of conjugates containing residues of lipophilic alcohols covalently bound to 5' end of oligodeoxyribonucleotides targeted against human plasminogen activator inhibitor (PAI-1) mRNA was synthesized via the oxathiaphospholane approach. The highest anti-PAI-1 activity in EA.hy 926 endothelial cell cultures was found for conjugates containing menthyl or heptadecanyl groups linked with an oligonucleotide complementary to a segment of human PAI-1 mRNA. The phosphodiester antisense oligonucleotides, which otherwise exhibit only limited anti-PAI-1 activity, were found to be more active than phosphorothioate oligonucleotides when conjugated to lipophilic alcohol residues. For menthyl conjugates an evidence of antisense mechanism of inhibition was found.

Styles APA, Harvard, Vancouver, ISO, etc.

32

Pitout, Ianthe, Loren L. Flynn, Steve D. Wilton et Sue Fletcher. « Antisense-mediated splice intervention to treat human disease : the odyssey continues ». F1000Research 8 (22 mai 2019) : 710. http://dx.doi.org/10.12688/f1000research.18466.1.

Texte intégral

Résumé :

Recent approvals of oligonucleotide analogue drugs to alter gene expression have been welcomed by patient communities but not universally supported. These compounds represent a class of drugs that are designed to target a specific gene transcript, and they include a number of chemical entities to evoke different antisense mechanisms, depending upon the disease aetiology. To date, oligonucleotide therapeutics that are in the clinic or at advanced stages of translation target rare diseases, posing challenges to clinical trial design, recruitment and evaluation and requiring new evaluation paradigms. This review discusses the currently available and emerging therapeutics that alter exon selection through an effect on pre-mRNA splicing and explores emerging concerns over safety and efficacy. Although modification of synthetic nucleic acids destined for therapeutic application is common practice to protect against nuclease degradation and to influence drug function, such modifications may also confer unexpected physicochemical and biological properties. Negatively charged oligonucleotides have a strong propensity to bind extra- and intra-cellular proteins, whereas those analogues with a neutral backbone show inefficient cellular uptake but excellent safety profiles. In addition, the potential for incorporation of chemically modified nucleic acid monomers, yielded by nuclease degradation of exogenous oligonucleotides, into biomolecules has been raised and the possibility not entirely discounted. We conclude with a commentary on the ongoing efforts to develop novel antisense compounds and enhance oligonucleotide delivery in order to further improve efficacy and accelerate implementation of antisense therapeutics for human disease.

Styles APA, Harvard, Vancouver, ISO, etc.

33

Frankel, Bruce, Sharon L. Longo, Gerard S. Rodziewicz et Charles J. Hodge. « Antisense oligonucleotide—induced inhibition of adrenocorticotropic hormone release from cultured human corticotrophs ». Journal of Neurosurgery 91, n^o 2 (août 1999) : 261–67. http://dx.doi.org/10.3171/jns.1999.91.2.0261.

Texte intégral

Résumé :

Object. Available therapies for Cushing's disease are often inadequate or involve the risk of significant morbidity. Accordingly, the need arises for the development of novel treatments, especially for cases caused by corticotroph hyperplasia, a condition difficult to treat using standard therapies. In this study, the authors investigated the use of phosphorothioate antisense oligonucleotides as a potential treatment for Cushing's disease.Methods. Corticotrophs, obtained from a patient with Cushing's disease in whom pathological findings showed multifocal areas of corticotroph adenoma and hyperplasia, were grown in tissue culture. By assessing cell viability and using immunoradiometric assay techniques, it was determined that these cells grew autonomously and secreted adrenocorticotropic hormone (ACTH) in vitro. A fully phosphorothioated antisense oligonucleotide was constructed to be complementary to the first 25 bp of the region coding for ACTH in exon 3 of the proopiomelanocortin precursor. After incubation of the corticotrophs with liposome-coated phosphorothioate antisense oligonucleotides, a greater than 90% decrease in ACTH release was noted on Days 3 and 6, compared with nonsense-treated controls (p < 0.05).Conclusions. Antisense oligonucleotides may prove to be a useful adjunct in treating Cushing's disease by targeting one of its fundamental problems, ACTH hypersecretion.

Styles APA, Harvard, Vancouver, ISO, etc.

34

Duval, Carine, Anne Nègre-Salvayre, Alain Doglio, Robert Salvayre, Luc Pénicaud et Louis Casteilla. « Increased reactive oxygen species production with antisense oligonucleotides directed against uncoupling protein 2 in murine endothelial cells ». Biochemistry and Cell Biology 80, n^o 6 (1 décembre 2002) : 757–64. http://dx.doi.org/10.1139/o02-158.

Texte intégral

Résumé :

Uncoupling protein 2 (UCP-2) belongs to the mitochondrial anion carrier family. It is ubiquitously expressed but is most abdundant in the reticuloendothelial system. In addition to uncoupling function, UCP-2 modulates the production of reactive oxygen species (ROS) by isolated mitochondria. Using an antisense oligonucleotide strategy, we investigated whether a defect in UCP-2 expression modulates ROS in intact endothelial cells. Murine endothelial cells (CRL 2181) pretreated by antisense oligonucleotides directed against UCP-2 mRNA exhibited a significant and specific increase in membrane potential and intracellular ROS level compared with control scrambled or anti-UCP-1 and -UCP-3 antisense oligonucleotides. These specific changes induced by UCP-2 antisense oligonucleotides were correlated with a rise in extracellular superoxide anion production and oxidative stress assessed by thiobarbituric acid reactive substance values. Taken together, these data suggest a role for UCP-2 in control of ROS production and subsequent oxidation of surrounding compounds mediating oxidative stress of endothelial cells. These data also support the notion that manipulations of UCP-2 at the genetic level could control ROS metabolism at the cellular level.Key words: UCP-2, reactive oxygen species, LDL oxidation, oxidative stress, mitochondria, endothelial cells.

Styles APA, Harvard, Vancouver, ISO, etc.

35

Misiura, K., M. Wójcik, A. Krakowiak, M. Koziołkiewicz, Z. Pawłowska, E. Pluskota, C. S. Cierniewski et W. J. Stec. « Synthesis, biochemical and biological studies on oligonucleotides bearing a lipophilic dimethoxytrityl group. » Acta Biochimica Polonica 45, n^o 1 (31 mars 1998) : 27–32. http://dx.doi.org/10.18388/abp.1998_4315.

Texte intégral

Résumé :

Dimethoxytritylphosphono-oligonucleotide conjugates have been prepared. They are totally resistant to nucleases present in human serum and do not affect cleavage of a complementary oligoribonucleotide by RNase H. Conjugates possessing a phosphate backbone gave better antisense inhibition of expression of plasminogen activator inhibitor type-1 within endothelial cells as compared with unconjugated oligonucleotides.

Styles APA, Harvard, Vancouver, ISO, etc.

36

Ozvaran, Mustafa K., Xiaobo X. Cao, Steven D. Miller, Brett A. Monia, Waun Ki Hong et W. Roy Smythe. « Antisense oligonucleotides directed at the bcl-xl gene product augment chemotherapy response in mesothelioma ». Molecular Cancer Therapeutics 3, n^o 5 (1 mai 2004) : 545–50. http://dx.doi.org/10.1158/1535-7163.545.3.5.

Texte intégral

Résumé :

Abstract Objective: Malignant pleural mesothelioma (MPM) is resistant to both conventional chemotherapy and apoptosis. The bcl-2 family proteins are major determinants of apoptotic homeostasis. MPM lines and tumors routinely overexpress the anti-apoptotic protein BCL-XL. We have previously shown that antisense inhibition of BCL-XL in MPM cells leads to apoptosis. We sought to determine whether antisense oligonucleotides directed at the bcl-xl gene product would augment response to a conventional chemotherapeutic agent in human mesothelioma cell lines. Methods: The human MPM cell lines REN and I-45 were exposed to two bcl-xl antisense oligonucleotides (15999, 16009) and one sense oligonucleotide (113529) construct at varying doses, followed by IC50 cisplatin. Cellular viability was assessed by a calorimetric assay, and apoptosis was evaluated by Hoechst staining, Annexin V staining, and sub-G1 fluorescence-activated cell sorter analysis. Western blot analysis of BCL-2 family proteins was performed following single agent and combined treatment. Isobologram mathematical analysis was used to determine whether or not combination therapies were additive or synergistic. Results: Cell viability was most affected with the 15999 antisense oligonucleotides plus IC50 cisplatin combination (70% of I-45 and 90% of REN cells killed), and apoptosis was markedly increased with this combination by all measures. Western blot demonstrated 15999 antisense oligonucleotides construct down-regulation of BCL-XL, but no further effect on expression of BCL-2 proteins with cisplatin. Isobologram analysis demonstrated 15999 + cisplatin synergistic effect. Conclusions: Exposure of human MPM cells to bcl-xl antisense oligonucleotides sensitizes human mesothelioma cells to the conventional chemotherapeutic agent cisplatin. Similar approaches using a combination of molecular and conventional treatment may have clinical utility for this tumor.

Styles APA, Harvard, Vancouver, ISO, etc.

37

Jeromin, A., R. L. Huganir et D. J. Linden. « Suppression of the glutamate receptor delta 2 subunit produces a specific impairment in cerebellar long-term depression ». Journal of Neurophysiology 76, n^o 5 (1 novembre 1996) : 3578–83. http://dx.doi.org/10.1152/jn.1996.76.5.3578.

Texte intégral

Résumé :

1. The role of the glutamate receptor subunit delta 2 in the induction of cerebellar long-term depression (LTD) was investigated by application of antisense oligonucleotides. The delta 2 subunit is selectively localized to Purkinje cells (PCs), with the highest levels being in the PC dendritic spines, where parallel fibers are received and where cerebellar LTD is expressed. 2. Immunocytochemical analysis of calbindin-positive PCs revealed that both the dendritic and somatic expression of delta 2 was reduced in antisense-but not in sense-treated cultures. An antisense oligonucleotide directed against the related subunit delta 1 did not affect the expression of delta 2 in PCs. 3. Cerebellar LTD may be reliably induced in a preparation of cultured embryonic cerebellar neurons from the mouse when parallel and climbing fiber stimulation are replaced by brief glutamate pulses and strong, direct depolarization of the PC, respectively. Application of an antisense oligonucleotide directed against delta 2 completely blocked the induction of LTD produced by glutamate/ depolarization conjunctive stimulation. A delta 2 sense oligonucleotide or an antisense oligonucleotide directed against the related delta 1 subunit had no effect. 4. The effect of the delta 2 antisense oligonucleotide was not related to attenuation of calcium influx via voltage-gated channels or calcium mobilization via metabotropic glutamate receptors, as assessed with fura-2 microfluorimetry. Current flow through alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-receptor-associated ion channels also appeared unaltered. All three of these processes have previously been shown to be required for cerebellar LTD induction. The observation that delta 2 is involved in a metabotropic-glutamate-receptor-independent signaling pathway that is required for LTD induction supports the view that delta 2 participates in the formation of a novel postsynaptic receptor complex.

Styles APA, Harvard, Vancouver, ISO, etc.

38

Abe, T., S. Suzuki, T. Hatta, K. Takai, T. Yokota et H. Takaku. « Specific Inhibition of Influenza Virus RNA Polymerase and Nucleoprotein Gene Expression by Liposomally Encapsulated Antisense Phosphorothioate Oligonucleotides in MDCK Cells ». Antiviral Chemistry and Chemotherapy 9, n^o 3 (juin 1998) : 253–62. http://dx.doi.org/10.1177/095632029800900306.

Texte intégral

Résumé :

We have demonstrated that antisense phosphorothioate oligonucleotides (S-ODNs) inhibit influenza A virus replication in MDCK cells. Liposomally encapsulated and free antisense S-ODNs with four target sites (PB1, PB2, PA and NP genes) were tested for their abilities to inhibit virus-induced cytopathogenic effects in a MTT assay using MDCK cells. The liposomally encapsulated S-ODN complementary to the site around the PB2 AUG initiation codon showed highly inhibitory effects. In contrast, the inhibitory effect of the liposomally encapsulated S-ODN targeted to PB1 was considerably decreased in comparison with that directed to the PB2 target site. The liposomally encapsulated antisense S-ODNs exhibited higher inhibitory activities than the free oligonucleotides, and showed sequence-specific inhibition, whereas free antisense S-ODNs were observed to inhibit viral adsorption to MDCK cells. Liposomal preparations of oligonucleotides facilitated their release from endocytic vesicles, and thus cytoplasmic and nuclear localization was observed. The activities of the antisense S-ODNs were effectively enhanced by using the liposomal carrier. Interestingly, the liposomally encapsulated FITC-S-ODN-PB2–as accumulated in the nuclear region of MDCK cells. However, weak fluorescence was observed within the endosomes and the cytoplasm of MDCK cells treated with the free antisense S-ODNs. The cationic lipid particles may thus be a potentially useful delivery vehicle for oligonucleotide-based therapeutics and transgenes, appropriate for use in vitro or in vivo.

Styles APA, Harvard, Vancouver, ISO, etc.

39

Zhao, Q., T. Waldschmidt, E. Fisher, CJ Herrera et AM Krieg. « Stage-specific oligonucleotide uptake in murine bone marrow B-cell precursors ». Blood 84, n^o 11 (1 décembre 1994) : 3660–66. http://dx.doi.org/10.1182/blood.v84.11.3660.bloodjournal84113660.

Texte intégral

Résumé :

Fluorescein isothiocyanate (FITC)-conjugated phosphodiester and phosphorothioate oligonucleotides were used in four-color flow cytometry with murine bone marrow cells stained with monoclonal antibody specific for the differentiation markers B220, S7 (CD43), and BP-1 to show possible stage-specific oligonucleotide uptake. Relatively low uptake was observed among pre-Pro- and early Pro-B cells. Late Pro- B- and pre-B cells had increased oligonucleotide uptake, whereas B cells had a lower level. Cell membrane binding of oligonucleotides varied during B-cell differentiation in parallel with internalization, which was documented by confocal microscopy. An FITC-conjugated polyanionic dextran sulfate also showed differentiation-related B-cell association, suggesting the presence of cell membrane binding sites specific for polyanions as opposed to a unique feature of the DNA backbone. Interpretation of antisense experiments in murine bone marrow cells will need to account for the heterogeneous oligonucleotide uptake among differentiating B cells.

Styles APA, Harvard, Vancouver, ISO, etc.

40

Susol, N. U. « INHIBITION OF THE EXPRESSION OF PHYSIOLOGICAL PRIONS WITH ANTISENS-OLIGONUCLEOTIDES ». Biotechnologia Acta 10, n^o 5 (octobre 2017) : 43–50. http://dx.doi.org/10.15407/biotech10.05.043.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

41

Sanghvi, Yogesh S., V. T. Ravikumar, Anthony N. Scozzari et Douglas L. Cole. « Applications of green chemistry in the manufacture of oligonucleotide drugs ». Pure and Applied Chemistry 73, n^o 1 (1 janvier 2001) : 175–80. http://dx.doi.org/10.1351/pac200173010175.

Texte intégral

Résumé :

We have modified the current phosphoramidite-based, solid-phase synthesis of antisense oligonucleotides to accommodate principles of green chemistry. In this article, we summarize key accomplishments that reduce or eliminate the use or generation of toxic materials, solvents, and reagents. Also discussed are methodologies that allow reuse of valuable materials such as amidites, solid-support, and protecting groups, thus improving the atom economy and cost-efficiency of oligonucleotide manufacture. Approaches to accident prevention and the use of safer reagents during oligonucleotide synthesis are also covered.

Styles APA, Harvard, Vancouver, ISO, etc.

42

Balcerzak, D., S. Poussard, J. J. Brustis, N. Elamrani, M. Soriano, P. Cottin et A. Ducastaing. « An antisense oligodeoxyribonucleotide to m-calpain mRNA inhibits myoblast fusion ». Journal of Cell Science 108, n^o 5 (1 mai 1995) : 2077–82. http://dx.doi.org/10.1242/jcs.108.5.2077.

Texte intégral

Résumé :

Previous studies have led to the hypothesis of a possible role for m-calpain (EC 3.4.22.17) in myoblast fusion in culture in vitro. To support this hypothesis, an antisense strategy has been used with cultured primary rat myoblasts. Using an appropriate antisense oligodeoxyribonucleotide to m-calpain mRNA, an inhibition of myoblast fusion has been observed, the maximum being obtained when the cell culture was treated with 30 microM of oligomer. Synthesis of m-calpain was decreased by 48% while high concentrations of antisense oligonucleotide do not significantly affect myoblast proliferation. The specificity of m-calpain intervention during fusion has also been confirmed using antisense oligonucleotides to mu-calpain and p94 mRNAs, respectively.

Styles APA, Harvard, Vancouver, ISO, etc.

43

Yamamoto, Tsuyoshi, Hidenori Yasuhara, Fumito Wada, Mariko Harada-Shiba, Takeshi Imanishi et Satoshi Obika. « Superior Silencing by 2′,4′-BNANC-Based Short Antisense Oligonucleotides Compared to 2′,4′-BNA/LNA-Based Apolipoprotein B Antisense Inhibitors ». Journal of Nucleic Acids 2012 (2012) : 1–7. http://dx.doi.org/10.1155/2012/707323.

Texte intégral

Résumé :

The duplex stability with target mRNA and the gene silencing potential of a novel bridged nucleic acid analogue are described. The analogue,2′,4′-BNANCantisense oligonucleotides (AONs) ranging from 10- to 20-nt-long, targeted apolipoprotein B.2′,4′-BNANCwas directly compared to its conventional bridged (or locked) nucleic acid (2′,4′-BNA/LNA)-based counterparts. Melting temperatures of duplexes formed between2′,4′-BNANC-based antisense oligonucleotides and the target mRNA surpassed those of 2′,4′-BNA/LNA-based counterparts at all lengths. Anin vitrotransfection study revealed that when compared to the identical length2′,4′-BNA/LNA-based counterpart, the corresponding2′,4′-BNANC-based antisense oligonucleotide showed significantly stronger inhibitory activity. This inhibitory activity was more pronounced in shorter (13-, 14-, and 16-mer) oligonucleotides. On the other hand, the 2′,4′-BNANC-based 20-mer AON exhibited the highest affinity but the worstIC50value, indicating that very high affinity may undermine antisense potency. These results suggest that the potency of AONs requires a balance between reward term and penalty term. Balance of these two parameters would depend on affinity, length, and the specific chemistry of the AON, and fine-tuning of this balance could lead to improved potency. We demonstrate that2′,4′-BNANCmay be a better alternative to conventional2′,4′-BNA/LNA, even for “short” antisense oligonucleotides, which are attractive in terms of drug-likeness and cost-effective bulk production.

Styles APA, Harvard, Vancouver, ISO, etc.

44

Agramunt, Jordi, Enrique Pedroso, Silvia Kreda, Rudolph Juliano et Anna Grandas. « Retro-1-Oligonucleotide Conjugates. Synthesis and Biological Evaluation ». Molecules 24, n^o 3 (6 février 2019) : 579. http://dx.doi.org/10.3390/molecules24030579.

Texte intégral

Résumé :

Addition of small molecule Retro-1 has been described to enhance antisense and splice switching oligonucleotides. With the aim of assessing the effect of covalently linking Retro-1 to the biologically active oligonucleotide, three different derivatives of Retro-1 were prepared that incorporated a phosphoramidite group, a thiol or a 1,3-diene, respectively. Retro-1–oligonucleotide conjugates were assembled both on-resin (coupling of the phosphoramidite) and from reactions in solution (Michael-type thiol-maleimide reaction and Diels-Alder cycloaddition). Splice switching assays with the resulting conjugates showed that they were active but that they provided little advantage over the unconjugated oligonucleotide in the well-known HeLa Luc705 reporter system.

Styles APA, Harvard, Vancouver, ISO, etc.

45

Yuan, Ahu, Brian Laing, Yiqiao Hu et Xin Ming. « Direct oligonucleotide–photosensitizer conjugates for photochemical delivery of antisense oligonucleotides ». Chemical Communications 51, n^o 30 (2015) : 6678–80. http://dx.doi.org/10.1039/c5cc00573f.

Texte intégral

Résumé :

Direct conjugation of photosensitizer to oligonucleotides allows spatial and temporal co-localization of the two modalities in the target cells and thus leads to superior photochemical delivery of oligonucleotides.

Styles APA, Harvard, Vancouver, ISO, etc.

46

Li, Yanjie, Jixue Li, Jun Wang, David R. Lynch, Xiulong Shen, David R. Corey, Darshan Parekh et al. « Targeting 3′ and 5′ untranslated regions with antisense oligonucleotides to stabilize frataxin mRNA and increase protein expression ». Nucleic Acids Research 49, n^o 20 (28 octobre 2021) : 11560–74. http://dx.doi.org/10.1093/nar/gkab954.

Texte intégral

Résumé :

Abstract Friedreich’s ataxia (FRDA) is a severe multisystem disease caused by transcriptional repression induced by expanded GAA repeats located in intron 1 of the Frataxin (FXN) gene encoding frataxin. FRDA results from decreased levels of frataxin; thus, stabilization of the FXN mRNA already present in patient cells represents an attractive and unexplored therapeutic avenue. In this work, we pursued a novel approach based on oligonucleotide-mediated targeting of FXN mRNA ends to extend its half-life and availability as a template for translation. We demonstrated that oligonucleotides designed to bind to FXN 5′ or 3′ noncoding regions can increase FXN mRNA and protein levels. Simultaneous delivery of oligonucleotides targeting both ends increases efficacy of the treatment. The approach was confirmed in several FRDA fibroblast and induced pluripotent stem cell-derived neuronal progenitor lines. RNA sequencing and single-cell expression analyses confirmed oligonucleotide-mediated FXN mRNA upregulation. Mechanistically, a significant elongation of the FXN mRNA half-life without any changes in chromatin status at the FXN gene was observed upon treatment with end-targeting oligonucleotides, indicating that transcript stabilization is responsible for frataxin upregulation. These results identify a novel approach toward upregulation of steady-state mRNA levels via oligonucleotide-mediated end targeting that may be of significance to any condition resulting from transcription downregulation.

Styles APA, Harvard, Vancouver, ISO, etc.

47

Takakura, Kazuki, Atsushi Kawamura, Yuichi Torisu, Shigeo Koido, Naohisa Yahagi et Masayuki Saruta. « The Clinical Potential of Oligonucleotide Therapeutics against Pancreatic Cancer ». International Journal of Molecular Sciences 20, n^o 13 (6 juillet 2019) : 3331. http://dx.doi.org/10.3390/ijms20133331.

Texte intégral

Résumé :

Although many diagnostic and therapeutic modalities for pancreatic cancer have been proposed, an urgent need for improved therapeutic strategies remains. Oligonucleotide therapeutics, such as those based on antisense RNAs, small interfering RNA (siRNA), microRNA (miRNA), aptamers, and decoys, are promising agents against pancreatic cancer, because they can identify a specific mRNA fragment of a given sequence or protein, and interfere with gene expression as molecular-targeted agents. Within the past 25 years, the diversity and feasibility of these drugs as diagnostic or therapeutic tools have dramatically increased. Several clinical and preclinical studies of oligonucleotides have been conducted for patients with pancreatic cancer. To support the discovery of effective diagnostic or therapeutic options using oligonucleotide-based strategies, in the absence of satisfactory therapies for long-term survival and the increasing trend of diseases, we summarize the current clinical trials of oligonucleotide therapeutics for pancreatic cancer patients, with underlying preclinical and scientific data, and focus on the possibility of oligonucleotides for targeting pancreatic cancer in clinical implications.

Styles APA, Harvard, Vancouver, ISO, etc.

48

Victorio, Carla Bianca Luena, Wisna Novera, Jing Yang Tham, Satoru Watanabe, Subhash G. Vasudevan et Ann-Marie Chacko. « Peptide-Conjugated Phosphorodiamidate Morpholino Oligomers for In Situ Live-Cell Molecular Imaging of Dengue Virus Replication ». International Journal of Molecular Sciences 21, n^o 23 (4 décembre 2020) : 9260. http://dx.doi.org/10.3390/ijms21239260.

Texte intégral

Résumé :

Current methods to detect and monitor pathogens in biological systems are largely limited by the tradeoffs between spatial context and temporal detail. A new generation of molecular tracking that provides both information simultaneously involves in situ detection coupled with non-invasive imaging. An example is antisense imaging that uses antisense oligonucleotide probes complementary to a target nucleotide sequence. In this study, we explored the potential of repurposing antisense oligonucleotides initially developed as antiviral therapeutics as molecular probes for imaging of viral infections in vitro and in vivo. We employed nuclease-resistant phosphorodiamidate synthetic oligonucleotides conjugated with cell-penetrating peptides (i.e., PPMOs) previously established as antivirals for dengue virus serotype-2 (DENV2). As proof of concept, and before further development for preclinical testing, we evaluated its validity as in situ molecular imaging probe for tracking cellular DENV2 infection using live-cell fluorescence imaging. Although the PPMO was designed to specifically target the DENV2 genome, it was unsuitable as in situ molecular imaging probe. This study details our evaluation of the PPMOs to assess specific and sensitive molecular imaging of DENV2 infection and tells a cautionary tale for those exploring antisense oligonucleotides as probes for non-invasive imaging and monitoring of pathogen infections in experimental animal models.

Styles APA, Harvard, Vancouver, ISO, etc.

49

Markov, Oleg V., Anton V. Filatov, Maxim S. Kupryushkin, Ivan V. Chernikov, Olga A. Patutina, Anton A. Strunov, Elena L. Chernolovskaya, Valentin V. Vlassov, Dmitrii V. Pyshnyi et Marina A. Zenkova. « Transport Oligonucleotides—A Novel System for Intracellular Delivery of Antisense Therapeutics ». Molecules 25, n^o 16 (11 août 2020) : 3663. http://dx.doi.org/10.3390/molecules25163663.

Texte intégral

Résumé :

Biological activity of antisense oligonucleotides (asON), especially those with a neutral backbone, is often attenuated by poor cellular accumulation. In the present proof-of-concept study, we propose a novel delivery system for asONs which implies the delivery of modified antisense oligonucleotides by so-called transport oligonucleotides (tON), which are oligodeoxyribonucleotides complementary to asON conjugated with hydrophobic dodecyl moieties. Two types of tONs, bearing at the 5′-end up to three dodecyl residues attached through non-nucleotide inserts (TD series) or anchored directly to internucleotidic phosphate (TP series), were synthesized. tONs with three dodecyl residues efficiently delivered asON to cells without any signs of cytotoxicity and provided a transfection efficacy comparable to that achieved using Lipofectamine 2000. We found that, in the case of tON with three dodecyl residues, some tON/asON duplexes were excreted from the cells within extracellular vesicles at late stages of transfection. We confirmed the high efficacy of the novel and demonstrated that MDR1 mRNA targeted asON delivered by tON with three dodecyl residues significantly reduced the level of P-glycoprotein and increased the sensitivity of KB-8-5 human carcinoma cells to vinblastine. The obtained results demonstrate the efficacy of lipophilic oligonucleotide carriers and shows they are potentially capable of intracellular delivery of any kind of antisense oligonucleotides.

Styles APA, Harvard, Vancouver, ISO, etc.

50

Kilanowska, Anna, Łukasz Nuckowski et Sylwia Studzińska. « Studying in vitro metabolism of the first and second generation of antisense oligonucleotides with the use of ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry ». Analytical and Bioanalytical Chemistry 412, n^o 27 (27 août 2020) : 7453–67. http://dx.doi.org/10.1007/s00216-020-02878-0.

Texte intégral

Résumé :

Abstract The aim of the present investigation was the analysis and identification of antisense oligonucleotide metabolism products after incubation with human liver microsomes regarding four different oligonucleotide modifications. Separation and detection methods based on the use of liquid chromatography coupled with quadrupole time-of-flight mass spectrometry were developed for this purpose. Firstly, the optimization of mass spectrometer parameters was done to select those which ensure the highest possible sensitivity of oligonucleotide analysis. This step was conducted for two chromatographic modes—ion pair chromatography and hydrophilic interaction liquid chromatography—due to their common application in oligonucleotide analysis. Based on sensitivity results, ion pair chromatography coupled with mass spectrometry was selected for the separation of model oligonucleotide mixtures in order to verify its selectivity for N-deleted metabolite separation. Next, the developed method was applied in the examination of oligonucleotides in vitro metabolism. First, wide optimization of incubation parameters was conducted including the concentration of the reaction buffer components. Obtained results indicated that both 3′-exonucleases and 5′-exonucleases contributed to the biotransformation of oligonucleotides. Moreover, it may be concluded that the number of metabolites depends on oligonucleotide modification and consequently its resistance to enzymatic attack. Thus, the number of the oligonucleotide metabolites decreased with the decrease of the resultant polarity of oligonucleotide caused by chemical modification.

Styles APA, Harvard, Vancouver, ISO, etc.

Articles de revues sur le sujet « Oligonucleotidi antisenso »

Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres