Molekulyarnaya Biologiya最新文献

Obesity is associated with changes in the gut microbiota, as well as with increased permeability of the intestinal wall. In 130 non-obese volunteers, 57 patients with metabolically healthy obesity (MHO), and 76 patients with metabolically unhealthy obesity (MUHO), bacterial DNA was isolated from stool samples, and the 16S rRNA gene was sequenced. The metabolic profile of the microbiota predicted by PICRUSt2 (https://huttenhower.sph.harvard.edu/picrust/) was more altered in patients with MUHO than MHO. Obesity, especially MUHO, was accompanied by an increase in the ability of the gut microbiota to degrade energy substrates, produce energy through oxidative phosphorylation, synthesize water-soluble vitamins (B1, B6, B7), nucleotides, heme, aromatic amino acids, and protective structural components of cells. Such changes may be a consequence of the microbiota adaptation to the MUHO-specific conditions. Thus, a vicious circle is formed, when MUHO promotes the depletion of the gut microbiome, and further degeneration of the latter contributes to the pathogenesis of metabolic disorders. The concentration of the trefoil factor family (TFF) in the serum of the participants was also determined. In MHO and MUHO patients, the TFF2 and TFF3 levels were increased, but we did not find significant associations of these changes with the metabolic profile of the gut microbiota.

Eukaryotic translation release factor eRF1 is an important cellular protein that plays a key role in translation termination, nonsense-mediated mRNA decay (NMD), and readthrough of stop codons. The amount of eRF1 in the cell influences all these processes. The mechanism of regulation of eRF1 translation through an autoregulatory NMD-dependent expression circuit has been described for plants and fungi, but the mechanisms of regulation of human eRF1 translation have not yet been studied. Using reporter constructs, we studied the effect of eRF1 mRNA elements on its translation in cell-free translation systems and HEK293 cell culture. Our data indicate the absence of an NMD-dependent autoregulatory circuit for human eRF1 expression. We found that the translation of the eRF1 coding sequence is most strongly influenced by the 5' untranslated region of eRF1 mRNA and the start codon of the upstream open reading frame. According to the transcription start database, eRF1 mRNA is characterized by high heterogeneity of the transcription start and a variable 5' untranslated region in length. In addition, the start codon of the CDS in eRF1 mRNA is located within the known translational regulator of short 5' untranslated regions (TISU), which also stimulates mRNA transcription of genes with high transcription start heterogeneity. We hypothesize that regulation of human eRF1 synthesis occurs at both the transcriptional and translational levels. At the transcription level, the length of the eRF1 5' untranslated region and the number of the upstream open reading frames in it are regulated. This regulation in turn, regulates the production of eRF1 at the translation level.

Molecules were proposed to block the functional cycles of the influenza virus A and SARS-CoV- 2. The blocker molecules efficiently bind inside the M2 and E channels of influenza A and SARS-CoV-2 viruses and block diffusion of H^(+)/K^(+) ions, thus distorting the virus functional cycle. A family of positively charged (+2 e.u.) molecular blockers of H^(+)/K^(+) ion diffusion through the M2 and E channels was proposed. The blocker molecules were diazabicyclooctane (DABCO) derivatives and were investigated for affinity for the M2 and E channels. Thermal dynamics of native and mutant channel structures and blocker binding were modeled by exhaustive docking. Binding energy calculations revealed within-channel, blocking, and extrachannel binding sites in the M2 and E channel proteins. Blocker molecules with higher affinity for the blocking sites were proposed. The most probable amino acid mutations the M2 and E channels were considered, the efficiency of channel blocking was analyzed, and optimal structures were assumed for the blocker molecules.

In previous studies, we found that the zinc finger proteins Su(Hw) and CG9890 interact with the Drosophila SAGA complex and participate in the formation of the active chromatin structure and transcription regulation. In this research, we discovered the interaction of the DUB module of the SAGA complex with another zinc finger protein, CG9609. ChIP-Seq analysis was performed, and CG9609 binding sites in the Drosophila genome were identified. Analysis of binding sites showed that they are localized predominantly at gene promoters. The CG9609 protein has been shown to be involved in the regulation of gene expression.

The CRISPR/Cas technology of targeted genome editing made it possible to carry out genetic engineering manipulations with eukaryotic genomes with a high efficiency. Targeted induction of site-specific DNA breaks is one of the key stages of the technology. The cell repairs the breaks via one of the two pathways, nonhomologous end joining (NHEJ) and homology-driven repair (HDR). The choice of the DNA repair pathway is determined by the architecture of the DNA break region formed as a result of terminal resection and depends on the cell cycle phase. NHEJ is the main pathway of double-strand break (DSB) repair in mammalian cells and involves a nonspecific ligation reaction. The reaction accuracy depends on the structure of break ends, and various insertions or deletions may arise as a result in the target genome region. Integration of a necessary sequence into the genome occurs via HDR, which requires a template with homology regions flanking a DSB. Introducing a genetic construct into a particular genomic locus is an important task, but is currently intricate and laborious to perform. However, the choice of the repair pathway can be of principal importance for basic research of gene functions and construction of animal models of human diseases to develop therapies. The review summarizes and systematizes the available information on strategies designed to increase the HDR efficiency. The strategies that most efficiently shift the balance towards HDR include use of NHEJ inhibitors, regulation of the key factors of homologous recombination, control of the cell cycle and chromatin status, and construction of HDR templates.

The low knock-in efficiency, especially in primary human cells, limits the use of the genome editing technology for therapeutic purposes, rendering it important to develop approaches for increasing the knock-in levels. In this work, the efficiencies of several approaches were studied using a model of knock-in of a construct coding for the peptide HIV fusion inhibitor MT-C34 into the human CXCR4 locus in the CEM/R5 T cell line. First, donor DNA modification was evaluated as a means to improve the efficiency of plasmid transport into the nucleus. The donor plasmid was modified to include the simian virus 40 (SV40) DNA nuclear targeting sequence (DTS) or binding sites for the transcription factor NF-κB, whose effects on the knock-in levels have not been described. The modification was ineffective in the model of MT-C34 knock-in into the CXCR4 locus. A second approach consisted in modification of Cas9 nuclease by introducing two additional nuclear localization signals (NLSs) and increased the knock-in level by 30%. Finally, blocking DNA repair via the nonhomologous end joining (NHEJ) pathway with DNA-dependent protein kinase inhibitors caused a 1.8-fold increase in knock-in. A combination of the last two approaches caused an additive effect. Thus, increasing the number of NLSs in the Cas9 protein and inhibiting DNA repair via the NHEJ pathway significantly increased the level of knock-in of the HIV-1 fusion inhibitory peptide into the clinically relevant locus CXCR4. The finding can be used to develop effective gene therapy approaches for treating HIV infection.

Modern genetic engineering technologies, such as base editing and prime editing (PE), have proven to provide the efficient and reliable genome editing tools that obviate the need for donor templates and double-strand breaks (DSBs) introduced in DNA. Relatively new, they quickly gained recognition for their accuracy, simplicity, and multiplexing capabilities. The review summarizes the new literature on the technologies and considers their architecture, methods to create editors, specificity, efficiency, and versatility. Advantages and disadvantages of the editors are discussed along with their prospective use in basic and applied research. The review may be useful for planning genome editing studies and analyzing their results to solve various problems of fundamental biology, biotechnology, medicine, and agriculture.

In previous studies, we purified the DUB-module of the Drosophila SAGA complex and showed that a number of zinc proteins interact with it, including Aef1 and CG10543. In this work, we conducted a genome-wide study of the Aef1 and CG10543 proteins and showed that they are localized predominantly on the promoters of active genes. The binding sites of these proteins co-localize with the SAGA and dSWI/SNF chromatin modification and remodeling complexes, as well as with the ORC replication complex. It has been shown that the Aef1 and CG10543 proteins are involved in the regulation of the expression of some genes on the promoters of which they are located. Thus, the Aef1 and CG10543 proteins are new participants in the cell transcriptional network and co-localize with the main transcription and replication complexes of Drosophila.

The sensitivity of human glioblastoma cells to virus-mediated oncolysis was investigated on five patient-derived cell lines. Primary glioblastoma cells (Gbl13n, Gbl16n, Gbl17n, Gbl25n, and Gbl27n) were infected with tenfold serial dilutions of the Leningrad-3 strain of the mumps virus, and virus reproduction and cytotoxicity were monitored for 96-120 h. Immortalized human non-tumor NKE cells were used as controls to determine the virus specificity. Four out of the five glioblastoma cell lines examined were susceptible to mumps virus infection, whereas no virus reproduction was observed in the non-tumor cell line. Moreover, the level of proapoptotic caspase-3 activity was increased in all infected cells 48 h after infection. The kinetics of viral RNA accumulation in the studied glioblastoma cell lines was comparable with the rate of cell death. The data suggest that glioblastoma cell lines were permissive for the mumps virus. Glioblastoma cell lines differed in type I IFN production in response to the mumps virus infection. In addition, it was shown that MV infection was able to induce immunogenic death of glioblastoma cells.