卷 57, 编号 5 (2023)

Malignant tumors are characterized by high cellular heterogeneity, including cancerous and non-malignant cells, as well as non-cellular components that are part of the tumor microenvironment. Cancer-associated fibroblasts often form a major component of the microenvironment, providing the very “soil” in which cancer cells thrive. Cancer-associated fibroblasts may contribute to tumor growth, invasion, metastasis, and resistance to therapy. However, clinical trials of treatment strategies targeting cancer-associated fibroblasts have largely failed. Moreover, there is evidence that cancer-associated fibroblasts are able to inhibit tumor development. In this review, we aimed to present the current understanding of the functional heterogeneity of cancer-associated fibroblasts, their bimodality in tumor development, and tumor progression. Understanding the tumor-promoting and tumor-inhibiting activities of cancer-associated fibroblasts may contribute to the development of new diagnostic and therapeutic approaches.

PARP1 and PARP2 proteins are members of the poly(ADP-ribose) polymerase family involved in the regulation of DNA repair and replication, RNA processing, ribosome biogenesis, transcription, and cell division and death. PARP1 and PARP2 are promising targets for the development of anticancer and can be used in treatment of cardiovascular and neurodegenerative diseases, as well as other disorders. WGR domain was shown to play a central role in functioning of PARP1 and PARP2 proteins. This review considers the mechanisms of functioning of WGR domains in PARP1 and PARP2 proteins, which have a number of similar and specialized properties. Understanding these processes is of great interest for fundamental science and will contribute to the development of more effective and selective inhibitors of PARP1 and PARP2.

Nucleotide sequence variability of whole mitochondrial genomes (mtDNA) was analyzed and mutation spectra were reconstructed (by L-chain of mtDNA) in four regional groups of indigenous populations representing Northeastern and Southern Siberia, Western Asia, and the Americas. The pyrimidine transitions were found to be predominant in all groups, and of these, the substitutions T→C were most frequent. The second most common in all regional groups (except Northeastern Siberia) are substitutions A→G. Of the transversions, in all the populations studied the substitutions C→A prevail. Between-regional differences in the distribution of nucleotide substitutions in mtDNA mutation spectra were not detected. However, a significant (4-fold) decrease in the number of mutations in mitochondrial gene pools was detected in the indigenous population of Northeastern Siberia compared to other regions. This may be due to the increased effect of negative selection on mtDNA in the Far North environment, which prevents the accumulation of new mutations, and gene drift, which is most pronounced in isolated and small populations of Northeastern Siberia. Because of the lack of between-regional differences in mtDNA mutation spectra, the results obtained do not allow us to confirm the hypothesis that the T→C substitution frequency appears to be a molecular marker of the level of oxidative stress in mitochondria (at least for generative mutations).

Bacillus pumilus ribonuclease (binase) exhibits cytotoxic and oncolytic properties, while at high concentrations it causes genotoxic effects. The use of mutants with reduced catalytic activity preserving the antitumor properties of the native enzyme could reduce the toxic side effects of the enzyme. Here, mutant forms of binase with Lys26Ala and His101Glu single substitutions were obtained by site-directed mutagenesis. A comparative analysis of Escherichia coli and Bacillus subtilis-based expression systems demonstrated the feasibility of using a bacilli-based heterologous system for production binase mutants. Binase mutants with reduced catalytic activity were isolated and purified with ion exchange chromatography in a homogeneous state with 25 mg/L yield. The catalytic properties of obtained mutants toward natural RNA-substrates in comparison with those for native binase were analyzed. The catalytic activity of the Lys26Ala and His101Glu mutants was 11 and 0.02%, respectively. It was found that the Lys26Ala mutant as well as the native binase exhibits selective cytotoxicity toward A549, BT-20 and HuTu 80 tumor cell lines, without causing toxic effects toward normal WI-38 cells. The mutant His101Glu did not exhibit cytotoxicity.

Vasovagal syncope (VVS) is the most common form of syncope. The mechanisms of VVS development are not entirely clear. It is known that there is a genetic predisposition to this disease, but the data on the role of individual genes are quite contradictory. Recently, a genome-wide association study identified a locus at chromosome 2q32.1 associated with a united group of diseases – syncope and collapse; among the single nucleotide polymorphisms (SNPs) of this locus, the most significant association was observed for rs12465214. In a homogeneous sample of patients according to the diagnosis of VVS, we analyzed the association of rs12465214, rs12621296, rs17582219 and rs1344706 located on chromosome 2q32.1, with this form of syncope. In the enrolled set, only rs12621296 was associated with VVS by itself, whereas associations of other SNPs were observed only in biallelic combinations. An epistatic interaction between the components of the combination rs12621296*A + rs17582219*A was revealed. The possible involvement of individual genes localized in the 2q32.1 locus in the genetic architecture of the VVS is discussed.

Histone acetyltransferases of the CBP/p300 family play the role of transcriptional regulators and are required for a number of biological processes (cell proliferation and differentiation, organism development, regulation of stress response and metabolism). In a study on the fruit fly Drosophila melanogaster, we analyzed for the first time the effect of overexpression and knockdown of the nejire (nej) ortholog gene in various tissues (fat body, intestine, nervous system) on lifespan. The activation of nej had both a positive and a negative effect on this parameter, depending on the driver and the tissue where nej was induced, as well as the sex of the animals. The effect of increasing lifespan (by 6–15%) was found in females with conditional overexpression of nej in the intestine and constitutive overexpression of nej in the nervous system. But in other cases, a shortening of life (up to 44%), or the absence of statistically significant changes were observed. In addition, activation of nej revealed changes in the expression of stress response genes (Sod1, Gadd45, Hsp27, Hsp68, Hif1). At the same time, knockdown of nej in most variants of the experiment caused a pronounced negative effect on the Drosophila lifespan.

Infections caused by Flaviviridae pose a threat in the modern world. The pathology of diseases arising from these infections is largely determined by the development of systemic inflammation. The cytokines interleukin-1 beta and interleukin-18 play a key role in triggering inflammation. Their secretion from cells, in its turn, is induced upon activation of inflammasomes. Activation of NLRP3 (NLR family pyrin domain-containing 3) inflammasomes was detected in the cells infected with Flaviviridae. Some nonstructural proteins of these viruses have been shown to be able to activate or inhibit the NLRP3 inflammasome, in particular, through interaction with its components. In this study, the functional NLRP3 inflammasome was reconstructed in human HEK293T cells and the effect of some nonstructural proteins of individual Flaviviridae viruses on it was studied. This model did not reveal any impact of nonstructural proteins NS1 of West Nile virus, NS3 of hepatitis C virus, NS5 of tick-borne encephalitis virus on the inflammasome components content. At the same time, in the presence of the NS1 of the West Nile virus and NS5 of the tick-borne encephalitis virus, the level of secretion of interleukin-1 beta did not change, whereas in the presence of the NS3 protein of the hepatitis C virus, it increased by 1.5 times. Thus, NS3 can be considered as one of the factors of NLRP3 inflammasome activation and inflammatory pathogenesis in chronic hepatitis C virus infection.

Proteasomes are key components of the ubiquitin-proteasome system. Various forms of proteasomes are known. During aging, disturbances in the functioning of proteasomes were revealed, as well as an increased expression of their individual forms. Considering these data, we studied the expression of genes encoding the constitutive and immune subunits of proteasomes in the cerebral cortex samples from C57BL/6 mice at the age of 60, 190, 380, and 720 days. In addition, the content of constitutive and immune proteasome subunits, chymotrypsin-like and caspase-like activities of proteasome pools, as well as the activity of the β5i immune subunit were studied in tissue homogenates. The chymotrypsin-like activity and the activity of the β5i subunit of different forms of proteasomes separated by electrophoresis under native conditions were characterized. Compared with samples from young animals, in the cerebral cortex of animals aged 720 days the following changes in the expression patterns of proteasome genes were revealed: a decrease in the expression of PSMB5 gene encoding the constitutive proteasome subunit β5; activation of genes encoding immune subunits β5i and β1i. In clarified tissue homogenates of aged mice, an increase in the content of immune subunits β1i and β2i was shown. In samples from old animals, decreased chymotrypsin-like activity and a tendency to a decrease in caspase-like activity of proteasomes as well as the β5i subunit activity were also revealed. Analysis of the activity of native complexes in the tissues of old animals revealed decreased chymotrypsin-like activity of both 26S and 20S proteasomes containing the β5i subunit. Based on the data obtained, it can be assumed that changes in the pool of non-constitutive proteasomes reflect aging-associated adaptive processes in mouse brain.

The marine free-living organism Trichoplax (phylum Placozoa) resembles the unicellular amoeba in shape and type of movement. Trichoplax diverged from the main evolutionary tree in the Neoproterozoic Era and is one of the simplest models of a multicellular animal, as well as a strong example of the ensemble of interacting cells in an organism during its development and movement. Two orthologs of mouse Piezo1 protein (6B3R) were found in two Trichoplax haplotypes H1 and H2 as a result of a search for similar sequences in the NCBI databases. Spatial models of the corresponding proteins, XP_002112008.1 and RDD46920.1, were created based on the structural alignment using a 6KG7 (mouse Piezo2) template. The analysis of domain structures was performed, and a limited graph of protein‒protein interactions of the hypothetical mechanosensor XP_002112008.1 was constructed. The possibility of signal transduction from the mechanoreceptor to membrane complexes, cytoplasm and cell nucleus was shown. It is assumed that mechanosensory receptors of Trichoplax are involved in the perception of force stimuli between neighboring cells and the environment. Based on the obtained data, we propose to use the primitive Trichoplax organism as the simplest multicellular model for mechanical and morphogenetic movements.

As an alternative to the classical method of erythrocyte hemagglutination, a latex agglutination assay based on the interaction of influenza viruses with the sialoglycoprotein fetuin immobilized on the surface of polystyrene microspheres, has been developed. Twelve influenza A virus strains of different subtypes and two influenza B viruses of different lines were tested. Simultaneous titration of viruses using the classical hemagglutination test and the proposed latex agglutination assay showed similar sensitivity and a high degree of correlation (R = 0.94). The obtained microspheres can be used for titration of viruses that recognize and bind sialylated glycans as receptors. In particular, latex aggregation was also induced by the Newcastle disease virus.