Russian Journal of Bioorganic Chemistry最新文献

Bacteria utilize a wide range of regulatory systems to adapt to life in various environmental conditions. Among these regulators small non-coding RNAs (ncRNAs) play a particularly important role. Acting primarily at the post-transcriptional level, small ncRNAs enable bacteria to rapidly adjust gene expression in response to external influences. They are involved in the regulation of almost all cellular processes, including replication, transcription, translation, energy and general metabolism, antibiotic resistance, bacterial virulence, as well as mechanisms associated with bacterial pathogenesis. Bacterial small ncRNAs are capable of mediating interactions between the bacterium and the host organism, directly modulating the expression of eukaryotic genes (most often those related to the immune response). Thus, ncRNAs serve as universal and powerful regulatory elements that ensure the survival and active functioning of bacteria under any adverse conditions.

Objective: Double-negative (DN) CD3⁺CD4^–CD8^– T lymphocytes represent a rare subset of unconventional peripheral T cells, accounting for only 3–5% of circulating T lymphocytes. Despite their low abundance, they play an important role in the pathogenesis of inflammation, cancer, autoimmune diseases, and allergic asthma. However, the cytokine profile of DN T cells remains poorly studied. This work aimed to comprehensively characterize the spectrum of cytokines, chemokines, and growth factors secreted by DN T cells. Methods: DN T cells were isolated from in vitro culture of human peripheral blood mononuclear cells (PBMCs). Cells were activated using anti-CD3/CD28 magnetic beads. The cytokine profile was assessed by multiplex analysis using xMAP technology, allowing simultaneous quantification of 48 analytes, including cytokines, chemokines, and growth factors. Results and Discussion: The pro-inflammatory αβTCR⁺CD161⁺ DN T cell subset exhibited a distinct secretory profile. Elevated levels of pro-inflammatory cytokines (TNFα, IFNγ, IL-3, IL-13, IL-27), chemokines (IL-8/CXCL8, MIG/CXCL9, MIP-1α/CCL3, MIP-1β/CCL4, RANTES/CCL5), and growth factors (M-CSF, GM-CSF) were detected. These findings suggest that DN T cells possess a broad and functionally diverse cytokine secretion potential, implicating them in a wide range of immune processes. Conclusions: The absence of regulatory cytokines and the predominant production of inflammatory mediators suggest their potential role in immune activation rather than suppression. These findings provide a basis for further investigation into the functional heterogeneity and therapeutic targeting of DN T cells in autoimmune and inflammatory diseases.

Objective: Studying heterotetrameric voltage-gated potassium channels and their blockers requires mastering the approach to create bioengineered protein constructs that will form channels of a given composition and stoichiometry in cells. It is also important to ensure that the covalent linkage of α-subunits does not hinder the proper functioning of the channel. Methods: Confocal microscopy and electrophysiological techniques were used to study the properties of the voltage-gated potassium Kv1.1 channel, formed in Neuro-2a cells from dimers of the human Kv1.1 α-subunits linked by the Lys-Leu dipeptide and fused at the N-terminus with mKate2 fluorescent protein (mKate2-(Kv1.1)₂). Results and Discussion: It was found that the linking of Kv1.1 α-subunits into a dimer did not cause changes either in the membrane expression of the channel or in the features of its cellular distribution compared with mKate2-Kv1.1 monomers. No differences were found between the channels based on mKate2-(Kv1.1)₂ dimers and mKate2-Kv1.1 monomers in the half-activation potential, channel activation constants, and the magnitude and nature of potassium ion currents. Conclusions: The data obtained suggest the possibility of creating bioengineered protein constructs by similarly linking two different α-subunits, which would form fluorescent heterotetrameric voltage-gated potassium channels with an α-subunit stoichiometry of 2 : 2 in mammalian cells.

The review summarizes the current understanding of nonclassical cannabinoid receptors, their signaling mechanisms, and roles in physiological and pathological processes. Nonclassical receptors (GPR55, GPR18, GPR119, etc.) demonstrate tissue-specific expression, interaction with multiple G proteins, and ligand-dependent activation of signaling pathways. GPR55 is involved in the regulation of pain, angiogenesis, and oncogenesis; GPR18 modulates inflammation and metabolism; and GPR119 is promising for diabetes therapy. Their ability to heterodimerize has been identified, which complicates their pharmacological profile. Nonclassical cannabinoid receptors represent promising targets for the treatment of socially significant diseases (cancer, diabetes, and neurodegeneration). However, their context-dependent activity requires an in-depth study to develop selective drugs.

Objective: Chloramphenicol is a broad-spectrum antibiotic that inhibits bacterial growth by preventing protein synthesis. However, its clinical use is highly limited due to serious side effects, including aplastic anemia. Methods: The aim of the study was to synthesize seven coumarin derivatives (CDC1–CDC7) from chloramphenicol to enhance their activity and improve compatibility with the human microbiome. The chemical synthesis began with the reduction of the nitro group of chloramphenicol to its amine counterpart. The Sandmeyer reaction was used to diazotize the resulting product, forming a compound containing a phenol group. This compound was then coupled with 3-ketoglutaric acid in a Pechmann condensation reaction, yielding the first coumarin (CDC1). By adding different phenolic compounds to this coumarin and esterifying them, (CDC2–CDC7) were synthesized with modifications to the off-side aromatic ring. The chemical structures of the synthesized coumarins were verified using various spectroscopic techniques, and their antimicrobial activities were evaluated using a broth microdilution method. The test microbes included six pathogenic bacteria, four pathogenic anaerobic bacteria, and two pathogenic fungi, while the biocompatibility of the compounds was assessed with three microbiome-derived bacteria. Results and Discussion: The synthesized coumarins exhibited a broader range of antimicrobial activity than the parent drug and showed good compatibility with the microbiome-derived bacteria tested. In addition, some structure-activity relationship (SAR) insights were obtained. The most significant finding was the influence of the off-side aromatic ring substitution on the antimicrobial activity. Specifically, chloride substitution provided the best anti-aerobic effect, methoxy substitution the best anti-anaerobic effect, and fluoride substitution the best antifungal activity. Conclusions: These results suggest that further research into the synthesized coumarins could lead to the development of a next-generation class of biocompatible broad-spectrum antimicrobial agents.

Objective: The visualization of macromolecular complexes is an essential task in modern bioorganic chemistry. This study presents the development of fluorescent molecular probes based on snake toxins for targeting nicotinic acetylcholine receptors (nAChRs). Chimeric constructs were produced by fusing snake toxins with a red fluorescent protein and evaluated for binding affinity and imaging capability. Methods: Three chimeric proteins were engineered by fusing snake toxins (α-bungarotoxin, α-cobratoxin, or neurotoxin NT-II) with the red fluorescent protein mKate2. These constructs were expressed in a bacterial system and purified by size-exclusion chromatography. The binding affinity of the probes to nAChRs was evaluated using competitive radioligand assay with radiolabeled α-bungarotoxin. Fluorescence microscopy was used to visualize receptor binding on human neuroblastoma SH-SY5Y cells. Results and Discussion: The chimeric fluorescent probes exhibited a high binding affinity for nAChRs derived from the electric organ of Torpedo californica, with half-maximal inhibitory concentration (IC₅₀) values in the nanomolar range. This demonstrates that the fusion of the snake toxins with mKate2 does not impair receptor binding. Furthermore, the probes enabled successful visualization of acetylcholine receptors on the surface of SH-SY5Y cells, confirming their functionality as imaging tools. The use of these constructs provides a non-radioactive, highly specific method for receptor localization in biological systems. Conclusions: The developed fluorescent molecular probes based on snake neurotoxins and mKate2 are effective tools for high-affinity binding and visualization of nAChRs. These chimeric proteins offer a promising approach for non-radioactive imaging in neurochemical and pharmacological studies.

Tuberculosis (TB) remains one of the world’s deadliest infectious diseases. It is also a leading cause of mortality among people living with HIV, accounting for one in three HIV-related deaths. The emergence and spread of multidrug-resistant (MDR) and extensively drug-resistant (XDR) Mycobacterium tuberculosis strains now threaten global TB control efforts. Current therapies require prolonged, multi-drug regimens that often lead to severe adverse effects and poor adherence, which further drive resistance. Isoniazid (INH) remains the cornerstone of first-line TB treatment, but its utility is compromised by resistance and hepatotoxicity—particularly in fast acetylators. To overcome these limitations, researchers have designed a variety of lipophilic INH analogs and hybrids, incorporating heterocyclic scaffolds (e.g., pyrazole, triazine, quinoline) to enhance cell-wall penetration and metabolic stability. Several of these compounds, including the cyclized derivative LL-3858, have advanced to preclinical and early clinical evaluation, demonstrating potent activity against drug-resistant strains and reduced toxicity profiles. This review summarizes the structural modifications of INH, highlights the most promising analogs and hybrids, and discusses their mechanisms of action, pharmacokinetics, and in vitro/in vivo efficacy. By offering shorter, safer, and more effective regimens, next-generation INH derivatives hold promise as key tools in the fight against MDR- and XDR-TB—especially in settings burdened by HIV co-infection—and may soon be poised for approval by regulatory authorities.

Objective: It is known that even a short-term high-fat diet has a negative effect on the metabolic health of the organism. However, under the influence of diet, first of all, the intestinal microbiota undergoes changes. The type of diet, dietary supplements and drugs affect both the taxonomic diversity of the microbiota and its functional state. It is known that with the participation of the intestinal microbiota, tryptophan is converted into indole and its various derivatives. The leading role of indoles in the regulation of the expression of tight junction proteins, and accordingly the regulation of intestinal permeability, has also been established. The aim of our study was to assess the effect of indole-3-acetate on the taxonomic diversity of the microbiota of the small and large intestines, as well as to establish the potential prebiotic value of this indole derivative under conditions of short-term use of a high-fat diet. Methods: C57/black6 SPF mice aged 4–5 weeks (n = 60, females) were randomly divided into six groups. A high-fat diet was achieved by feeding laboratory animals a high-fat diet of animal origin, providing up to 30% of the total calories. Indole-3-acetate was administered together with a standard or high-fat diet via an atraumatic intragastric tube at a single dose of 0.1392 mg per mouse for 28 days. Results and Discussion: In our study, we showed for the first time that in C57/black6 SPF mice on a short-term high-fat diet, indole-3-acetate increases the representation of Bifidobacterium pseudolongum in the microbial community of both the small intestine and the large intestine. Whereas the increase in Akkermansia muciniphila was only in the microbial community of the large intestine. Indole-3-acetate intake provides normoglycemia in animals on a short-term high-fat diet. Conclusions: The use of indole-3-acetate in various metabolic diseases associated with a high-fat diet and dysbacteriosis may be a promising therapeutic approach to correct metabolic disorders through modulation of the microbiotic community.

8-Oxo-2′-deoxyguanosine is a well-known marker of oxidative stress. Research over the past decade suggests that this compound is probably not a byproduct of oxidative DNA damage, but an important bioregulator driving the cellular response to stress. This review collected and analyzed data on the participation of 8-oxo-2′-deoxyguanosine in the processes of mutagenesis, DNA repair, and regulation of gene expression, inflammatory responses, adaptive stress response, apoptosis, and cellular transformation. Particular attention is paid to the potential of 8-oxo-2′-deoxyguanosine as a therapeutic agent for the treatment of inflammatory, autoimmune, degenerative, and oncological diseases, as well as of traumatic and toxic injuries.