Molekulyarnaya Biologiya最新文献

Diallyl thiosulfinate (allicin) effectively inhibits the growth of various microorganisms, including antibiotic-resistant strains, so it can be considered to be a broad-spectrum antimicrobial compound. However, its instability in the bloodstream hinders its use as a therapeutic agent. We have synthesized a number of allicin analogues, both natural and synthetic, and evaluated in vitro their antimicrobial properties against Staphylococcus aureus and Candida albicans. The synthesized compounds were shown to exhibited more pronounced antifungal activity than antibacterial. Among the compounds obtained, synthetic di-(2,2,2-trichloroethyl) ester of 3,3'-[(thio)sulfinyl]dipropionic acid effectively inhibited the growth of both fungi and bacteria at concentrations comparable to those of known antimicrobial agents used in medical practice.

Solving the problem of multidrug resistance currently requires the development of nonstandard approaches, since the potential for creating new antibiotics is almost exhausted. Controlling the metabolism of a pathogen in order to increase its susceptibility to antibacterial therapy is considered the most promising area of research for the creation of new combination drugs. In recent years, the number of studies devoted to investigation the role of the biosynthesis of the cell wall component ADP-heptose in the sensitivity of bacteria to antibiotics, as well as in the pathogenesis of bacterial infection, has increased. This review examines the main directions of scientific research in the field of use of ADP-heptose and its analogues in the treatment of bacterial infections. The exclusive role of ADP-heptose in the induction of an immune response is known through the activation of the NF-κB signaling pathway and the synthesis of pro-inflammatory cytokines. Our latest work has shown that disruption of the synthesis of ADP-heptose and the efflux of sedoheptulose-7-phosphate from the pentose phosphate pathway induces a redox imbalance and completely disorganizes the metabolism of low molecular weight thiols such as hydrogen sulfide, cysteine, and glutathione, which makes the bacterial cell extremely vulnerable to the action of antibiotics. We demonstrate that the hypersensitivity of ADP-heptose mutants to a wide range of antibiotics is explained by a new metabolic status rather than by changes in cell wall permeability. Thus, potential inhibitors of ADP-heptose biosynthesis can combine several positive qualities: an immunomodulatory effect and a powerful potentiating effect in combination with antibiotic therapy.

Cardiovascular diseases remain a predominant global cause of mortality, with a noteworthy rise in the risk of morbidity with advancing age. Besides, it accompanied by a phenomenon of disease rejuvenation in the circulatory system. Currently, epigenetic modifications play a key role in the genesis of cardiovascular diseases (CVD), influencing the complex interaction between genotype and phenotype variability. Consequently, delving into the realm of epigenetic markers offers a promising avenue to unravel the molecular underpinnings of cardiovascular disease pathogenesis. This study endeavors to pinpoint epigenetic markers intricately linked with age-related transformations in the cardiovascular system. The study revealed a robust correlation with age for two cardiological parameters: R wave tension in the augmented left arm lead (RaVL) and carotid-femoral pulse wave velocity (cfPWV). Moreover, these parameters exhibited a strong correlation with the DNA methylation level of 21 CpG-sites (CpGs) examined through the Illumina EPIC array. Notably, the majority of these identified CpG-sites are affiliated with genes involved in the development of pathologies of the cardiovascular system.

Currently, empirical therapy regimens are often used in the treatment of infectious diseases that are not based on data on pathogen resistance. One of the main reasons for the unjustified prescription of antibacterial drugs is the lack of rapid and at the same time universal methods of determining the antibiotic resistance of the pathogen. The most widely used culture techniques, such as the microdilution method, require a long time to generate the necessary number of bacterial cells. Less time-consuming methods of resistance assessment (genomic or proteomic) are based on the determination of specific markers (resistance genes, overexpression of certain proteins, etc.); in this case, the specific protocol is most often applicable to a narrow number of both microorganism strains and antibiotics. Previously, we demonstrated the possibility of using Raman spectroscopy (RS) technology for quantitative determination of the product of bacterial cell activity in the MTT assay, formazan, directly in the cell suspension. The absence of the formazan isolation step simplifies the assay and increases its accuracy. The analysis time did not exceed 2 h while maintaining the versatility of the MTT assay itself. Limitations of the developed protocol for RS detection of the MTT assay results include a high sensitivity threshold of 10^(7) CFU/mL for the bacterial cell concentration, so a preliminary stage of cultivation is necessary for samples with a low bacterial content. Here, we propose a method to increase the sensitivity of formazan determination by utilizing the effect of surface-enhanced Raman scattering (SERS) on gold nanoparticles. As a result of this study, the optimal conditions for SERS analysis of formazan in both solution and suspension of Escherichia coli cells are selected. Formazan signal amplification due to the use of SERS on gold nanoparticles instead of RS allowed us to reduce the sensitivity threshold for the number of bacterial cells in the sample by at least 30 times, up to 3 x 10^(5) CFU/mL. This sensitivity is not the limit of the SERS technology capabilities because the introduction of other types of nanoparticles (more optimal in shape, size, concentration, etc.) into the experiment will allow one to achieve even higher signal amplification.

Despite nearly a century of therapy for gonococcal infection with a variety of antimicrobials, more than 80 million cases of the disease are reported annually worldwide. The gonorrhea pathogen, Neisseria gonorrhoeae, exhibits an exceptional capability of developing antimicrobial resistance due to its high genetic flexibility. As an obligate pathogen, the gonococcus has evolved mechanisms to evade host defenses by engaging with the innate and adaptive immune responses in both men and women. N. gonorrhoeae can establish residence within epithelial cells, macrophages, and neutrophils. Strains resistant to each of the drugs used in gonorrhea therapy have emerged via genetic variation and horizontal gene transfer. The type IV secretion system plays a critical role in horizontal gene transfer (HGT), driving the evolvement of antimicrobial resistance. The review explores the pathogenesis and immune evasion mechanisms, antimicrobial resistance, genetic variability, laboratory analysis methods for the pathogen, and emerging trends in diagnosis and treatment of gonococcal infections.

The extracellular matrix (ECM) provides structural support and regulates cell activity. ECM dysfunction due to metabolic pathologies or aging can lead to disease. Developing ECM protectors is crucial for the etiological prevention and treatment of pathologies associated with ECM alterations. Key mechanisms of pathological changes in the ECM include nonenzymatic reactions, such as glycation and glycoxidation. The potential of agents as ECM protectors can be assessed by their capability of inhibiting these processes. Compounds based on heterocyclic scaffolds with partially hydrogenated isoindole fragments were tested for capability of slowing down the formation of advanced glycation end-products (AGEs). A combination of in silico and in vitro approaches was employed. In the in silico study, the energies of the frontier molecular orbitals of the compounds were determined using the ab initio method with the 6-311G(d,p) basis set. Antiglycation activity was then investigated in the glycation reaction of bovine serum albumin (BSA) with glucose, using BSA as a model protein. Pyridoxamine served as a reference compound. Antiglycation activities of the compounds were evaluated spectrofluorometrically by measuring the fluorescent products at excitation/emission wavelengths of 440/520 nm, which are not typically used for assessing antiglycation properties. Glycation and oxidation products in the human skin can be detected at these wavelengths. Their amount correlates with chronological age, in contrast to certain other glycation products. It was found experimentally that the energies of the frontier molecular orbitals of the compounds can serve as predictors of their capability of slowing down the formation of fluorescent products detected at 440/520 nm. Inhibiting the formation of the products may be significant for treatment and prevention of diseases, including metabolic, fibrotic, or age-associated conditions. At 100 μM, series of hydrogenated 3a,6-epoxyisoindole-7-carboxylic acids (compounds of type XIII) and cyclopenta[b]furo[2,3-c]pyrrole-3-carboxylic acids (structures of type XIX) were found to display the most pronounced antiglycation properties.

Serine/threonine protein kinase ATM (ataxia-telangiectasia mutated) performs a number of aging-related functions in the cell. In addition to regulating the cell response to DNA damage, ATM phosphorylates vacuolar ATPase and thus leads to lysosome degradation and cell senescence. The geroprotective potential of the selective ATM inhibitor KU-60019 was studied in three Drosophila species with different lifespans. KU-60019 was shown to increase the lifespan in the long-lived species D. virilis and moderate-lifespan D. melanogaster. However, the lifespan was reduced after KU-60019 treatment in the short-lived species D. kikkawai. KU-60019 was found to increase the survival in hyperthermia, oxidative stress, and starvation in all of the three Drosophila species, but had no effect on age-dependent changes in locomotor activity. Suppression of the tefu gene for an ATM homolog by RNA interference (RNAi) also increased the lifespan and stress tolerance in D. melanogaster compared with control strains. Thus, the effect of KU-60019 on the lifespan was shown to vary among the Drosophila species. The variation might be related to transcriptome differences observed previously and requires further experimental study.

Klebsiella oxytoca is a causative agent of various community-acquired and nosocomial infections, including urinary tract infections, nosocomial pneumonia, antibiotic-associated diarrhea, etc. However, the virulence factors of the species are still incompletely understood. The adhesive potential of the urological isolate K. oxytoca NK-1 was characterized using several substrates. The strain was found to efficiently adhere to epithelial cell lines, glycosylated and nonglycosylated proteins, and polystyrene and to induce yeast cell agglutination, indicating the presence of type 1 and type 3 fimbriae, which are organelles that facilitate adhesion of enterobacteria to a wide range of substrates. Both type 1 and type 3 fimbrial operons were identified in the strain genome, the latter occurring in two copies. Mutants with inactivated fimbrial genes were constructed. Inactivation of type 1 fimbrial genes did not affect bacterial adhesion. Inactivation of type 3 fimbrial genes increased adhesion of K. oxytoca NK-1 to lung epithelial cells (line H1299), and mannose was shown to serve as an additional inducer of higher adhesion. Adhesion of the mutant to other substrates was not affected. The findings suggested a multifactorial nature for the K. oxytoca adhesive apparatus and the possibility of compensatory expression or overexpression of genes for alternative adhesins in the absence of type 1 and/or 3 fimbriae.

The human primase-polymerase PrimPol is a key participant of the mechanism of DNA synthesis restart during replication fork stalling at sites of DNA damage. PrimPol has DNA primase activity and synthesizes DNA primers that are used by processive DNA polymerases to continue replication. Recruitment of PrimPol to the sites of DNA damage, as well as stimulation of catalytic activity, depends on interaction with the replicative protein RPA, which binds single-stranded DNA. The C-terminal domain of PrimPol contains a negatively charged RPA-binding motif (RBM), mutations in which disrupt the interaction between two proteins. The RBM motif also plays a role in the negative regulation of PrimPol interaction with DNA. Deletion of the RBM dramatically increases PrimPol affinity to DNA and stimulates PrimPol activity. The mechanism of RBM-mediated regulation of PrimPol activity is unclear. The relatively strong negative charge of RBM potentially may contribute to the interaction of PrimPol with RPA and DNA. RBM contains two negatively charged regions RBM-A and RBM-B. In this work, we additionally added (substitution V546E) or decreased (substitution D547H) a negative charge in RBM-B PrimPol and characterized these mutant variants biochemically. It was shown that the local change in the RBM-B charge has no effect on the interaction of PrimPol with DNA and RPA, or of the catalytic activity of the enzyme.

Transposable elements (TEs) increase the frequency of spontaneous mutations in the genome and are capable of altering the gene structure and expression. TE activities and genomic positions are therefore important to study. A combination of two sequencing methods proved advantageous in searching for TE insertions and chromosomal rearrangements, i.e., full-genome nanopore sequencing allowed detection of TE insertions, and transcriptome sequencing on the Illumina platform evaluated their effects on gene expression. Genome sequencing data were obtained for Drosophila melanogaster strains with the SS (w^(1), flamenco mutant) and MS (w^(1), flamenco mutant, active gypsy copy) flamenco phenotypes. The wild-type laboratory strain D32 was used as a control. TE insertions and deletions in euchromatin genome regions and gene introns were found in the mutant and wild-type strains as compared with a reference genome (NCBI GCF_000001215.4). The genomes under study were searched for insertions and deletions in RNA interference system genes and genes differentially expressed in the SS and MS strains. TE insertions were detected in various regions of the AGO3, CG17147, Su(var)3-3, Gasz, CG43348, moody, and CG17752 genes. A change in TE position did not correlate with a decrease or an increase in gene transcription in most genes. A chromosomal rearrangement affecting the 3'-untranslated region was observed in the vig gene. A de novo genome assembly was conducted for the MS strain based on the long-read sequencing data. Higher expression of CR45822 and pst in the SS and MS strains was found to be due to a triplication rather than to changes in regulatory sequences or a TE insertion.