Purpose: The therapeutic use of antisense oligonucleotides will likely involve their administration over protracted periods of time. The oral route of drug dosing offers many advantages over other possible routes when chronic drug administration is necessary. However, little is known about the potential for oligonucleotide uptake from the gastrointestinal tract. This issue is addressed in the current work.
Methods: We have developed a simple procedure for radiolabeling oligonucleotides by reductive alkylation with 14C-formaldehyde. We have utilized this approach, as well as 5' addition of fluorophores, to prepare labeled methylphosphonate and phosphorothioate oligonucleotides for use in intestinal transport studies. An everted rat gut sac model was employed to compare the transport of oligonucleotides to that of model compounds whose permeation properties are better understood.
Results: We demonstrate that both methylphosphonate and phosphorothioate oligonucleotides are passively transported across the intestinal epithelium, probably by a paracellular route. The rates of transport for both types of oligonucleotides were similar, and were significantly greater than that of the very high MW polymer blue dextran, but were lower than the transport rate of valproic acid, a low MW compound known to have high oral availability.
Conclusions: A significant degree of permeation of oligonucleotides across the gastrointestinal epithelium does occur, but it is still unclear whether this is sufficient to permit effective oral administration of oligonucleotides as drugs.
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http://dx.doi.org/10.1023/a:1016296617434 | DOI Listing |
J Genet
January 2024
Department of Animal Science, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran,
Myostatin is a known negative regulator of muscle tissue growth. Thus, an inhibitor of myostatin may be therapeutically useful as an anabolic agent for the muscle tissue. A promising gene-silencing approach for gene therapy is DNA interference (DNAi), a sequence that is complementary to the promoter region of a target gene.
View Article and Find Full Text PDFMolecules
May 2019
Institute of Organic Chemistry and Biochemistry AS CR, v.v.i., Flemingovo nám. 2, 166 10 Prague 6, Czech Republic.
We have developed a robust solid-phase protocol which allowed the synthesis of chimeric oligonucleotides modified with phosphodiester and -methylphosphonate linkages as well as their and variants. The novel -methylphosphonate-derived modifications were obtained by oxidation, sulfurization, and amidation of the -methyl-()-phosphinate internucleotide linkage introduced into the oligonucleotide chain by -phosphonate chemistry using nucleoside--methyl-()-phosphinates as monomers. The -phosphonate coupling followed by oxidation after each cycle enabled us to successfully combine -phosphonate and phosphoramidite chemistries to synthesize diversely modified oligonucleotide strands.
View Article and Find Full Text PDFBiochemistry
August 2017
Department of Chemistry and Biochemistry, Utah State University, Logan, Utah 84322-0300, United States.
Catalytically promiscuous enzymes are an attractive frontier for biochemistry, because enzyme promiscuities not only plausibly explain enzyme evolution through the mechanism of gene duplication but also could provide an efficient route to changing the catalytic function of proteins by mimicking this evolutionary process. PP1γ is an effectively promiscuous phosphatase for the hydrolysis of both monoanionic and dianionic phosphate ester-based substrates. In addition to its native phosphate monoester substrate, PP1γ catalyzes the hydrolysis of aryl methylphosphonates, fluorophosphate esters, phosphorothioate esters, and phosphodiesters, with second-order rate accelerations that fall within the narrow range of 10-10.
View Article and Find Full Text PDFInorg Chem
July 2010
Department of Chemistry, University at Buffalo, State University of New York, Buffalo, New York 14260, USA.
Ln(S-THP)(3+) complexes are paramagnetic chemical exchange saturation transfer (PARACEST) agents for magnetic resonance imaging (MRI; S-THP = (1S,4S,7S,10S)-1,4,7,10-tetrakis(2-hydroxypropyl)-1,4,7,10-tetraazacyclododecane, Ln(III) = Ce(III), Eu(III), Yb(III)). CEST spectra at 11.7 T show that the PARACEST effect of these complexes is enhanced at neutral pH in buffered solutions containing 100 mM NaCl upon the addition of 1-2 equiv of diethylphosphate (DEP).
View Article and Find Full Text PDFNucleic Acids Res
May 2008
Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, USA.
Aminoacyl-tRNA synthetases (AARS) are an essential family of enzymes that catalyze the attachment of amino acids to specific tRNAs during translation. Previously, we showed that base-specific recognition of the tRNA(Pro) acceptor stem is critical for recognition by Escherichia coli prolyl-tRNA synthetase (ProRS), but not for human ProRS. To further delineate species-specific differences in acceptor stem recognition, atomic group mutagenesis was used to probe the role of sugar-phosphate backbone interactions in recognition of human tRNA(Pro).
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