Publications by authors named "Zatsepin T"

Non-canonical nucleic acid structures play significant roles in cellular processes through selective interactions with proteins. While both natural and artificial G-quadruplexes have been extensively studied, the functions of i-motifs remain less understood. This study investigates the artificial aptamer BV42, which binds strongly to influenza A virus hemagglutinin and unexpectedly retains its i-motif structure even at neutral pH.

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Non-canonical nucleic acid structures possess an ability to interact selectively with proteins, thereby exerting influence over various intracellular processes. Numerous studies indicate that genomic G-quadruplexes and i-motifs are involved in the regulation of transcription. These structures are formed temporarily during the unwinding of the DNA double helix; and their direct determination is a rather difficult task.

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During liver development, bipotential progenitor cells called hepatoblasts differentiate into hepatocytes or cholangiocytes. Hepatocyte differentiation is uniquely associated with multi-axial polarity, enabling the anisotropic expansion of apical lumina between adjacent cells and formation of a three-dimensional network of bile canaliculi. Cholangiocytes, the cells forming the bile ducts, exhibit the vectorial polarity characteristic of epithelial cells.

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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 -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 , and intracellular localization.

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Background: Prostate adenocarcinoma (PRAD) is the second leading cause of cancer-related deaths in men. High variability in DNA methylation and a high rate of large genomic rearrangements are often observed in PRAD.

Results: To investigate the reasons for such high variance, we integrated DNA methylation, RNA-seq, and copy number alterations datasets from The Cancer Genome Atlas (TCGA), focusing on PRAD, and employed weighted gene co-expression network analysis (WGCNA).

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Hepatic fibrosis remains a significant clinical challenge due to ineffective treatments. 4-methylumbelliferone (4MU), a hyaluronic acid (HA) synthesis inhibitor, has proven safe in phase one clinical trials. In this study, we aimed to ameliorate liver fibrosis by inhibiting HA synthesis.

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A template-assisted assembly approach to a C fullerene-like double-stranded DNA polyhedral shell is proposed. The assembly employed a supramolecular oligonucleotide dendrimer as a 3D template that was obtained via the hybridization of siRNA strands and a single-stranded DNA oligonucleotide joined to three- or four-way branched junctions. A four-way branched oligonucleotide building block (a ) was designed for the assembly of the shell composed of three identical self-complementary DNA single strands and a single RNA strand for hybridization to the DNA oligonucleotides of the template.

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Reactive oxygen species (ROS) are highly reactive products of the cell metabolism derived from oxygen molecules, and their abundant level is observed in many diseases, particularly tumors, such as hepatocellular carcinoma (HCC). In vivo imaging of ROS is a necessary tool in preclinical research to evaluate the efficacy of drugs with antioxidant activity and for diagnosis and monitoring of diseases. However, most known sensors cannot be used for in vivo experiments due to low stability in the blood and rapid elimination from the body.

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The COVID-19 pandemic has shown the urgent need for new treatments for coronavirus infections. Nucleoside analogs were successfully used to inhibit replication of some viruses through the incorporation into the growing DNA or RNA chain. However, the replicative machinery of coronaviruses contains nsp14, a non-structural protein with a 3'→5'-exonuclease activity that removes misincorporated and modified nucleotides from the 3' end of the growing RNA chain.

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To overcome immune tolerance to cancer, the immune system needs to be exposed to a multi-target action intervention. Here, we investigated the activating effect of CpG oligodeoxynucleotides (ODNs), mesyl phosphoramidate CpG ODNs, anti-OX40 antibodies, and OX40 RNA aptamers on major populations of immunocompetent cells . Comparative analysis of the antitumor effects of vaccination with CpG ODNs and anti-OX40 antibodies, as well as several other combinations, such as mesyl phosphoramidate CpG ODNs and OX40 RNA aptamers, was conducted.

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Single-domain antibodies (sdAbs, VHHs, or nanobodies) are a promising tool for the treatment of both infectious and somatic diseases. Their small size greatly simplifies any genetic engineering manipulations. Such antibodies have the ability to bind hard-to-reach antigenic epitopes through long parts of the variable chains, the third complementarity-determining regions (CDR3s).

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Progress in RNA metabolism and function studies relies largely on molecular imaging systems, including those comprising a fluorogenic dye and an aptamer-based fluorescence-activating tag. G4 aptamers of the Mango family, typically combined with a duplex/hairpin scaffold, activate the fluorescence of a green light-emitting dye TO1-biotin and hold great promise for intracellular RNA tracking. Here, we report a new Mango-based imaging platform.

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We propose catalytically synthesized nanozymes based on Prussian Blue (PB) and azidomethyl-substituted poly (3,4-ethylenedioxythiophene) (azidomethyl-PEDOT) as novel electrocatalytic labels for DNA/RNA sensors. Catalytic approach allowed to synthesize highly redox and electrocatalytically active Prussian Blue nanoparticles functionalized with azide groups that enable 'click' conjugation with alkyne-modified oligonucleotides. Both competitive and sandwich-type schemes were realized.

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DNA-intercalated motifs (iMs) are facile scaffolds for the design of various pH-responsive nanomachines, including biocompatible pH sensors. First, DNA pH sensors relied on complex intermolecular scaffolds. Here, we used a simple unimolecular dual-labeled iM scaffold and minimized it by replacing the redundant loop nucleosides with abasic or alkyl linkers.

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We propose a novel approach to disperse and extract small-diameter single-walled carbon nanotubes (SWCNTs) using an aqueous solution of riboflavin and Sephacryl gel. The extraction of small-diameter semiconducting SWCNTs was observed, regardless of the initial diameter distribution of the SWCNTs. Dispersion of SWCNTs occurs due to the adsorption of π-conjugated isoalloxazine moieties on the surface of small-diameter nanotubes and interactions between hydroxy groups of ribityl chains with water.

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Reactive oxygen/nitrogen species (ROS/RNS) are formed during normal cellular metabolism and contribute to its regulation, while many pathological processes are associated with ROS/RNS imbalances. Modern methods for measuring ROS/RNS are mainly based on the use of inducible fluorescent dyes and protein-based sensors, which have several disadvantages for in vivo use. Intravital electrochemical nanosensors can be used to quantify ROS/RNS with high sensitivity without exogenous tracers and allow dynamic ROS/RNS measurements in vivo.

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Nanomedicine has revolutionized the available treatment options during the last decade, but poor selectivity of targeted drug delivery and release is still poses a challenge. In this study, doxorubicin (DOX) and magnetite nanoparticles were encapsulated by freezing-induced loading, coated with polymeric shell bearing two bi-layers of polyarginine/dextran sulphate and finally modified with HER2-specific DARPin proteins. We demonstrated that the enhanced cellular uptake of these nanocarriers predominantly occurs by SKOV-3 (HER2+) cells, in comparison to CHO (HER2-) cells, together with the controlled DOX release using low intensity focused ultrasound (LIFU).

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A lot of long non-coding RNAs (lncRNAs) are expressed in human cells in a number of transcripts of different lengths and composition of exons. In case of cancer-associated lncRNAs, an actual task is to determine their specific isoforms, since each transcript can perform its own function in carcinogenesis and might have a unique expression profile in various types of tumors. For the first time, we analyzed the expression of CASC8 lncRNA in human pancreatic ductal adenocarcinoma cell lines and found an abundant isoform that was previously considered as the minor one in this type of cancer.

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Carbon-encapsulated iron nanoparticles (Fe@C) with a mean diameter of 15 nm have been synthesized using evaporation-condensation flow-levitation method by the direct iron-carbon gas-phase reaction at high temperatures. Further, Fe@C were stabilized with bovine serum albumin (BSA) coating, and their electromagnetic properties were evaluated to test their performance in magnetic hyperthermia therapy (MHT) through a specific absorption rate (SAR). Heat generation was observed at different Fe@C concentrations (1, 2.

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Autologous macrophage transfer is an emerging platform for cell therapy. It is anticipated that conventional macrophage reprogramming based on ex vivo polarization using cytokines and ligands of TLRs may enhance the therapeutic effect. We describe an alternative approach based on small interfering RNA (siRNA) knockdown of selected molecular cues of macrophage polarization, namely EGR2, IRF3, IRF5, and TLR4 in Raw264.

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A benzothiazole-substituted derivative (X) of 1,3-diaza-2-oxophenoxazine was evaluated with respect to its ability to engage in Ag(I)-mediated homo base pair formation in two different DNA duplexes. The metal binding was determined by a combination of temperature-dependent UV spectroscopy, CD spectroscopy, and fluorescence spectroscopy, indicating the incorporation of two Ag(I) ions to generate a dinuclear X-Ag(I)-X base pair. Interestingly, a luminescence increase was observed upon metal binding.

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Glucose and lipid metabolism are crucial functional systems in eukaryotes. A large number of experimental studies both in animal models and humans have shown that long non-coding RNAs (lncRNAs) play an important role in glucose and lipid metabolism. Previously, human lncRNA DEANR1/linc00261 was described as a tumor suppressor that regulates a variety of biological processes such as cell proliferation, apoptosis, glucose metabolism and tumorigenesis.

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Telomerase RNA has long been considered to be a noncoding component of telomerase. However, the expression of the telomerase RNA gene is not always associated with telomerase activity. The existence of distinct gene expression products possessing different functions were demonstrated recently.

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Glioblastoma (GBM) is the most frequent and aggressive primary brain cancer in adult patients. A variety of long non-coding RNAs play an important role in the pathogenesis of GBM, however the molecular functions of most of them still remain elusive. Here, we investigated linc-RoR (long intergenic non-protein coding RNA, regulator of reprogramming) using GBM neurospheres obtained from 12 different patients.

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