MLE/DHX9 is a DNA/RNA helicase that performs important functions in gene expression regulation in eukaryotes. However, the specific role of MLE and the mechanisms by which this regulation is carried out remain poorly understood. This work is devoted to the study of the effect of MLE on the constitutive expression of nuclear receptor genes in D. melanogaster. The nuclear receptors Eip75B, DHR3, and Hr4 are evolutionarily conserved and have orthologs in humans. In D. melanogaster, Eip75B, DHR3, and Hr4 are activated in the ecdysone cascade, but they are also expressed at a stable level in various tissues and at various stages of development. The experiments were carried in vivo at the imago stage in females and in S2 cell culture. Taken together, the results indicate that MLE is involved in activating the expression of these genes. At the same time, the helicase activity of MLE is not necessary for activation. The results obtained extend knowledge about the functions of MLE beyond dosage compensation, as potentially conserved in evolution, and contribute to understanding the mechanisms of regulation of nuclear receptor expression.

The interplay between innate immunity and other signaling pathways remains a central focus in immunological research, with considerable ongoing investigation. Of particular interest are studies exploring the influence of the hormonal system on the innate immunity of Drosophila melanogaster. In this study, we performed a comprehensive analysis of the combined effects of the insect hormone 20-hydroxyecdysone (20E) and spores from the fungus Metarhizium anisopliae on the innate immune response in D. melanogaster S2 cell culture, addressing this interaction for the first time. Our results demonstrate that, compared to cells exposed solely to M. anisopliae spores, pretreatment with 20E followed by fungal challenge led to a reduction in the transcription of antimicrobial peptide genes CecropinA1 and Drosocin. In contrast, expression of the Metchnikowin (Mtk) gene was upregulated. No significant alterations were observed in the transcription levels of Drosomycin or in genes encoding key receptors, transcription factors, or other components of innate immune signaling pathways. Furthermore, knockdown of the transcription factor Relish markedly decreased Mtk expression, highlighting its central role in hormone-modulated antifungal immunity. These findings reveal complex hormonal-immune crosstalk that differentially regulates AMP gene expression in Drosophila.

The regularities of tumor induction and growth in mice were studied during a single ex vivo irradiation of Ehrlich adenocarcinoma ascites cells with a beam of protons, helium ions (Не), and carbon ions (С) at doses of 10, 20, and 30 Gy. It was shown that, when tumor cells were exposed to all types of radiation, a dose-dependent increase in the antitumor effect was observed in the latent period of tumor appearance, the frequency of their induction, and tumor growth inhibition. According to all indices, C had the greatest antitumor effect, He occupied an intermediate position, and protons caused the least effect.

Today, breast cancer (BC) occupies a leading position in prevalence and mortality from oncological diseases among the female population worldwide. Ferroptosis is a special type of cell death associated with peroxidation of intracellular lipids. It is a promising option for the therapy of BC resistant to traditional methods of treatment. The ELOVL5 gene, involved in the elongation of long-chain polyunsaturated fatty acids (LC-PUFA), was previously associated with BC progression. In this work, the effect of ELOVL5 knockdown on the dynamics of ferroptosis induction in MDA-MB-231 cells under the influence of docosahexaenoic acid (DHA) and erastin was investigated. A comparative analysis of changes in the expression of individual genes under the influence of these agents was also carried out. It was shown that a decrease in ELOVL5 expression increases cell sensitivity to both agents, while DHA causes earlier cell death. The protective effect of ferroptosis inhibitors (ferrostatin-1 and deferoxamine) confirmed the involvement of this pathway in the observed effects. Differences in the expression of genes associated with oxidative stress, inflammation and proliferation were also revealed, indicating different molecular trajectories of ferroptosis in cells with different ELOVL5 gene expression. Thus, the present study deepens the understanding of the contribution of the ELOVL5 gene to the regulation of ferroptosis and can be used in the development of targeted therapy for breast cancer.

The tomato gene Mi-1,2 is currently the only commercially available source of resistance to the root-knot nematode Meloidogyne incognita, which loses activity when soil temperatures exceed 28°C. The study aimed to investigate the components of the tomato immune system to root-knot nematode associated with salicylic acid (SA) at elevated (34°C) and normal (25°C) temperatures. The obtained results showed that the Mi-1,2-mediated immune response is disrupted at 34°C. At elevated temperatures in plants infested with nematodes, the synthesis of salicylic acid and the activity of phenylalanine ammonia lyase are reduced, and catalase is inhibited, a decrease in the activity of which was discovered at the stage of nematode penetration into the roots and the creation of feeding structures-giant cells. Elevated temperature decreased the activity of the PR-1 gene, a marker of systemic plant resistance. These results provide important information on the sensitivity temperature of the Mi-1.2 resistance gene and the effect of elevated temperature on SA-dependent components of the immune system that are associated with tomato resistance to the nematode.

A comparative structural-phylogenetic and expression analysis of the SNAT1 and SNAT2 genes of tomato Solanum lycopersicum and garlic Allium sativum was performed. It was shown that the SNAT1 and SNAT2 are intron-rich and intronless genes, respectively, and may have different evolutionary origins. It was predicted that, unlike the chloroplast protein SNAT1, SNAT2 has features of chloroplast-mitochondrial localization. The highest expression level of SNAT1 and SNAT2 was detected (in silico and qRT-PCR) in leaves, while in roots and mature storage organs it was significantly lower; SNAT2 was not expressed in garlic roots and bulbs. It was found that the expression level of SNAT2 in tomato plant organs is higher than the expression level of SNAT1, while for garlic the opposite ratio was observed.

The fatty acid (FA) composition of the mantle, foot (muscle), and hepatopancreas of the European pearl mussel Margaritifera margaritifera from the Kem River (estuary), the Ukhta River, and the Vozhma River (Republic of Karelia, Russia) was studied for the first time. All tissues of the pearl mussel from the studied rivers were shown to have a higher content of saturated and polyunsaturated FAs compared to monounsaturated ones, which may be due to the post-spawning period. In the hepatopancreas of the pearl mussel, a predominance of polyunsaturated FAs due to the FAs of n-3 family, as well as a higher amount of 16:1(n-7), 18:1(n-7), 18:3(n-3), 20:5(n-3), and 22:6(n-3) FAs and a lower amount of 16:0, 18:0, 18:1(n-9), 20:1(n-11), and 20:4(n-6) FAs compared to the foot and mantle was shown. An important distinctive feature of M. margaritifera is the high amount of 20:1(n-11) FA. Mollusks from the Kem River estuary were distinguished by a higher content of 18:0 and 20:5(n-3) FAs in all the studied tissues and a lower content of 18:1(n-7), 18:2(n-6), and 22:6(n-3) FAs. The obtained data are important for monitoring work to assess the state of pearl mussel populations in different rivers of the European North (in particular, using physiological and biochemical indices).

The effect of low-intensity femtosecond laser radiation (200 fs, 525 nm, 5 mW) on cognitive abilities of mice at late stages after exposure was studied. Open field and Barnes maze tests were performed 5 months after a single irradiation to assess general activity, anxiety level, and spatial learning ability. Irradiated animals retained normal motor skills, did not show anxiety, and demonstrated stable long-term memory when performing spatial learning tasks. Irradiated mice showed no changes in the model of locomotor and psychoemotional behavior or disturbances in spatial learning and memory, while they better preserved the memory trace on the 9th day after training compared to control animals. The obtained results indicate the potential of photobiomodulation with femtosecond pulses as a promising non-drug method for the prevention and correction of cognitive impairment, including those caused by radiation therapy.

Hypertrophic cardiomyopathy (HCM) is the most common hereditary heart disease with a prevalence ranging from 1 : 500 to 1 : 200 individuals. The development and clinical presentation of HCM do not always conform to the traditional view of its monogenic inheritance pattern. One key to addressing this issue may lie in identifying epigenetic mechanisms regulating gene expression, particularly DNA methylation, involved in the pathogenesis of the disease and modifying its course. Using previously obtained whole-genome data, we identified four extended genomic regions with reduced methylation levels in the myocardium of patients with HCM. These include region chr2:113993204-113994075, located within the transcribed area of the PAX8 gene, as well as three other regions (chr6:31148369-31148577, chr8:11565217-11567212, and chr8:22132791-22133357), which are associated with promoters of genes PSORS1C3, GATA4, and PIWIL2, respectively. We demonstrated altered expression of PAX8 and GATA4 genes containing one each of these four mentioned regions. Our findings will expand the currently very limited understanding of the unique features of epigenetic regulation in this condition.

Syngeneic models are widely used in experimental oncology both for modeling tumor diseases and for testing anticancer drugs. However, when testing targeted drugs aimed at human tumor-associated antigens, the presence of target antigens in the animal's body is important. In this study, a syngeneic cell line with stable expression of two genes-the ERBB2 gene encoding human epidermal growth factor receptor type 2 (HER2) and the NanoLuc luciferase gene-was created based on murine mammary gland carcinoma. Optical bioimaging methods have proven that the created cell line is characterized by stable expression of ERBB2 and NanoLuc in vitro and in vivo, retains the aggressive growth of the original 4T1 cell line in animals, and forms spontaneous metastases that are detected in the animal's body by intravital biovisualization methods.

Disruption of the normal expression of histone genes lead to the development of various pathologies. One of the key stages of gene expression is the export of mRNA from the nucleus to the cytoplasm. The TREX-2 protein complex regulates the export of the majority of poly(A)-containing mRNAs. Previously, we demonstrated that TREX-2 is also associated with histone mRNP particles and participates in the nuclear export of histone mRNAs, which lack poly(A)-tails. In this study we investigated the interaction of TREX-2 proteins with the histone mRNA processing machinery. It was shown that TREX-2 interacts with the FLASH protein, a key protein of the specialized histone mRNA processing machinery and a component of the histone locus body (HLB). The TREX-2 complex is recruited through its interaction with FLASH to processed histone mRNAs.

DHX9 helicase and its ortholog MLE in D. melanogaster participate in different stages of gene expression. Both helicases are important for the formation and functioning of the nervous system in humans and D. melanogaster, respectively. However, the role of helicase activity of DHX9 and MLE in the regulation of gene expression has been poorly studied, and the existing data are quite contradictory. This work is devoted to the study of the role of helicase activity of MLE in the regulation of gene expression in D. melanogaster. A site of intense MLE binding was found on chromosome 4 of D. melanogaster, in locus 102F. It was shown that MLE is a co-activator of expression of the Dyrk3, Toy, Sox102F, Shaven, and Fuss genes located in this locus. For this, the helicase activity of MLE is required. Genes whose expression depends on MLE are expressed at a high level in the nervous system of D. melanogaster and are essential for its proper development. The obtained data contributes to the study of potentially evolutionarily conserved functions of MLE.

The functioning of proteins in a cell cannot be studied without analyzing their content in the cell. The most commonly used method of analysis, Western blotting, cannot always be used due to the impossibility of obtaining antibodies that specifically recognize the protein of interest. At the same time, Western blotting is a semi-quantitative method of analysis and does not allow determining the exact content of protein in the cell. In this work, we used the protein complementation method for the qualitative and quantitative assessment of the hTERP protein content in the cell. Using genome editing, a HiBiT epitope was introduced to the C-terminus of the hTERP protein, the complementation of which with LgBiT restores active luciferase. As a result, we determined the hTERP protein content in the HEK293T cell line.

In this study, promoter sequences predicted by the MAHDS method in the Oryza sativa genome were analyzed using three genome annotations: RefSeq NCBI, Rice Genome Annotation Project, and Ensembl. Part of the predicted promoters was found to be located near annotated genes, which indicates their potential functional role. The remaining sequences, considered as potentially novel regulatory elements, were examined using YAPP for the presence of core promoter motifs and their functional combinations. All analyzed predicted promoters contain either an Inr or a TATA motif-the key elements involved in transcription initiation. The identified motif combinations suggest a high likelihood of transcriptional activity in these sequences, and the consistency of the results with annotated data and CAGE-seq signals supports the reliability and applicability of the MAHDS method.

The TREX-2 complex is responsible for the export of mRNA from the nucleus to the cytoplasm and consists of four proteins. It was recently shown that the PCID2 subunit of TREX-2 is responsible for the specific recognition of mRNA by the TREX-2 complex. The majority of the protein contains the PCI domain, which has surfaces for RNA binding. The PCI domain includes the central region of the protein, which has a surface for non-specific RNA binding, M-PCID2, and the C-terminal part of the PCI domain and the C-terminal part of the protein, C-PCID2, which has a surface for specific RNA recognition. The N-terminal part of PCID2 contains a region whose function is unknown. Since the TREX-2 complex binds to only a specific mRNA and only at a specific stage, we hypothesized that the N-terminal part of PCID2 might modulate the binding of C-PCID2 to RNA by binding to it and covering its RNA-binding domain. We showed that the N-terminal region interacts with C-PCID2. The binding of C-PCID2 to RNA in this case is not impaired. In addition, the binding of C-PCID2 to RNA does not disrupt its interaction with the N-terminal part of the protein (N-PCID2). Thus, C-PCID2 can interact with N-PCID2 and RNA by different surfaces. This intrinsic interaction is probably necessary at one of the stages of functioning of the TREX-2 complex.

6-azido-2-chloropurine-2'-deoxyriboside, a valuable precursor for the preparation of modified 2-chloropurine nucleosides substituted at the 6-position of the heterocyclic base, was obtained by enzymatic transglycosylation. 6-azido-2-chloropurine-2'-deoxyriboside can also be used as a photocross-linking agent to study the nucleic acids-proteins interactions. A type II nucleoside deoxyribosyltransferase from Lactobacillus leichmannii was used as a biocatalyst. The optimal conditions for the formation of 6-azido-2-chloropurine-2'-deoxyriboside using 7-methyl-2'-deoxyguanosine as a carbohydrate residue donor were determined.

Changes in the cardiovascular system are systemic during aging. The aim of this work is to describe systemic patterns of changes in heart rate variability (HRV) parameters during aging in healthy subjects. HRV data of 73 healthy subjects aged 11-76 years from the PhysioNet database were used, which were divided into three groups: young (11-17 years old), middle-aged (24-55 years old), and elderly (56-76 years old). Using the Hilbert-Huang method and wavelet analysis, spectral curves of empirical HRV modes were obtained, for which the maxima and their corresponding frequencies were determined. Nine modes were identified. A twofold decrease in the autonomic control modes and, to a lesser extent, in the very-low-frequency modes (0.002-0.04 Hz) was found in the elderly compared to the young. Very-low-frequency HRV oscillations (<0.001 Hz) did not change with age. The results obtained may serve as a basis for physiological interpretation of HRV regulation processes and may be useful in the development of controlled anti-aging therapy.

PCID2 protein is a subunit of the eukaryotic complex TREX-2, which is responsible for nuclear export of mRNA. PCID2 plays an important role in the complex, being responsible for the recognition and binding of the mRNA molecule. PCID2 of D. melanogaster interacts with a region of ras2 (fr4_2) mRNA and has two interaction sites located in its PCI domain: the M-PCID2 region, which non-specifically binds to mRNA, and the C-terminal part (C-PCID2), which specifically recognizes the ras2 fr4_2 mRNA sequence. At the same time, specific binding to C-PCID2 requires a preliminary nonspecific interaction with M-PCID2. It remains unclear how the transition from primary nonspecific interaction to specific interaction occurs: whether both regions interact with RNA simultaneously or whether the nonspecific interaction is required only at the first step for subsequent specific binding. This study showed that the binding of M-PCID2 and C-PCID2 to ras2 fr4_2 RNA is competitive. M-PCID2 binds more efficiently and displaces C-PCID2 from the complex with the ras2 mRNA fragment. Thus, additional factors are required to replace the M-PCID2 contact by C-PCID2 during the interaction of the full-length PCID2 protein with ras2 mRNA. We also showed that point mutations in M-PCID2 that disrupt the interaction of the full-length PCID2 with RNA result in a greater association of M-PCID2 with RNA. It is likely that the increased affinity of M-PCID2 for RNA disrupts the ability to replace M-PCID2 with C-PCID2 within the full-length PCID2.

A comparative study of three drugs (KRRKPGP peptide, warfarin and acetylsalicylic acid) with an anticoagulant effect in the body was conducted. The drugs were administered orally in effective doses (peptide and warfarin 100 µg/kg, acetylsalicylic acid 1 mg/kg) for 7 days to laboratory rats with metabolic syndrome induced by a high-calorie diet (HCD). As early as 20 h after the last administration of the drugs, a decrease in the concentration of total cholesterol, low-density lipoprotein cholesterol, and triglycerides and an increase in the concentration of high-density lipoprotein cholesterol and a slowdown in the growth of body weight in rats were detected, which persisted for 7 days after stopping their administration. The greatest hypolipidemic effect was caused by the KRRKPGP peptide.

Despite significant progress in oncotherapy, oncological diseases continue to pose a serious problem for public health. The limited penetration of nanoscale therapeutic drugs into solid tumors, due to the presence of tight intercellular junctions, does not allow achieving therapeutically effective drug concentrations in distal tumor cells, which leads to the appearance of drug resistance. In this work, to increase the accumulation of HER2-specific small gold nanoparticles (DARPin-AuNPs) in solid tumors, the use of these particles in combination with the protein-opener of desmoglein junctions (junction opener 4, JO-4) is proposed. A quantitative assessment of gold biodistribution in mice showed that co-administration of DARPin-AuNP/JO-4 in vivo increased particle accumulation in tumors by approximately 2.5-fold compared to administration of DARPin-AuNP alone.

The expression profile of the key carotenoid biosynthesis genes (ZmPSY1, ZmPSY2, ZmLcyE) was determined in the dynamics of cold stress and post-stress recovery in the leaves of Zea mays L. plants of four cold-tolerant (breeders' data) inbred lines (L-5580-1, L-6097-1, L-5254-3, and L-5272-6). It was shown that, under normal growing conditions, the expression level of all three genes in the L-5580-1 line was significantly higher compared to other lines. It was revealed that low-temperature exposure affects the trends of gene expression fluctuations in a similar way between the lines. It was determined that, in the stress dynamics, the co-expression pattern of the ZmPSY1 and ZmPSY2 genes in the leaves of L-5580-1 plants is coordinated with changes in the carotenoid content.