Vol 89, No 11 (2024)

Dependence on psychoactive substances is a phenomenon that is based on the alterations of common molecular cellular mechanisms, structures and neuronal networks underlying normal brain functioning and realizing stress response, reinforcement and aversion, learning and memory. As a result, aberrant neuroplasticity states associated with somatic changes are formed, which determine the pathogenesis and symptoms of chemical dependence and at the same time can be considered as targets for the development of therapies for such addictions. An integrative scheme of stress and neuroplastic changes participation in the formation of the vicious circle of pathological substance dependence syndrome based on a holistic approach is presented.

Chemokines are immunoregulatory proteins with pleiotropic functions involved in processes of neuromodulation, neurogenesis and neurotransmission. The chemokines effect on the central nervous system plays an important role in modulating various conditions. It can have negative consequences for central nervous system functions, including the development of alcohol-related disorders. In the review we analyzed the available literature data devoted to the problem of chemokines participation in the pathogenesis, formation of the clinical picture and remission of alcohol use disorder both in animal models and in the study of patients with alcoholism. Presented data confirm the hypothesis that alcohol-induced chemokine production can modulates the processes of chronic neuroinflammation. Thus, the data summarized and presented in this review are devoted to the current direction of research in the field of psychiatry, which will be in demand by both scientists and clinical specialists.

With prolonged ethanol ingestion, disturbances in the emotional spectrum develop, and memory problems are noted. These symptoms may be mediated by the development of neurochemical changes in the hippocampus of the brain. Although there is evidence that the hippocampus is vulnerable to chronic alcohol intoxication and the development of neuroinflammation and neurodegeneration in this brain region, the key molecular mechanisms have not been identified. The aim of the study was to investigate changes in the immune system in the periphery as well as in the hippocampus of the rat brain during ethanol exposure and during pharmacological correction with azithromycin (AZM). Long-term ethanol exposure was modeled by injecting rats with a 20% ethanol solution (4 g/kg) for 4 weeks. General biochemical and clinical blood analysis was performed in animals. The expression levels of cytokine genes (Il1β, Ccl2, Il6, Il11, Il13, Tnfα, Tgfβ) and toll-like receptor system genes (Tlr3, Tl4, Tlr7, Nfkb1, Hmgb1) and TLR system-related microRNA molecules (miR-182, miR-155-5p, miR-96-5p, miR-let-7b) were evaluated in the hippocampus. IL-1β protein content was also assessed in the hippocampus. Prolonged alcoholization caused an increase in mRNA and protein levels of IL-1β, and a decrease in mRNA levels of Tnfα, Il11, Tlr3, and Tlr7. The contents of miR-let-7b, miR-96, and miR-155 were downregulated in the hippocampus during long-term alcoholization. Elevated Il1β mRNA and protein levels and Hmgb1 mRNA levels were maintained under conditions of ethanol withdrawal. Tlr3 mRNA levels were decreased under withdrawal. Administration of AZM reduced IL-1β, TLR3 and HMGB1 mRNA levels under conditions of ethanol withdrawal, and at higher doses of the drug, a decrease in IL-1β protein levels in the hippocampus of rat brain was observed. Thus, the study provided new insights into the mechanisms of neuroinflammation in the brain hippocampus during prolonged exposure to ethanol and upon withdrawal. The results obtained allowed us to outline a number of tasks for further studies in this direction.

Quite often, conception of a child occurs after consuming small doses of alcohol. However, the effect of this factor on offspring has not been studied at all. The aim of this study was to study the level of motor activity, anxiety-like and depressive-like behavior, sensitivity to the analgesic effect of ethanol, as well as the activity of the enzymes DPP-IV, PEP and ADG in the blood of rats whose fathers received ethanol immediately before mating. As a result of the experiments conducted, it was found that males conceived by fathers who were intoxicated have significant differences in behavior compared to control animals. Thus, motor activity in rats conceived by males under the influence of alcohol was 2-2.5 times less intense, they decreased the severity of anxiety-like and depressive-like behavior. In such animals, the activity of DPP-IV and ADG was increased and the activity of PEP in the blood was reduced. In rats conceived by fathers under the influence of alcohol, the analgesic effect of ethanol decreased, and there was also a decrease in the reaction of ADG, DPP-IV and PEP to ethanol administration. It is assumed that a single use of ethanol by male rats immediately before mating leads to a decrease in the methylation of paternal inherited genes in offspring. As a result, the activity of a number of enzymes may change, which leads to a change in the balance of neuropeptides involved in formation of animal behavior.

Previous studies have shown that the combined effect of fetal hypoxia and maternal stress hormones predetermines tendency to nicotine addiction in adulthood. This study in rats aimed to investigate the effect of prenatal severe hypoxia (PSH) on acetylcholine metabolism in the developing brain, as well as on expression of acetylcholine receptors chrna4 and chrna7 in both the developing brain and adult brain structures following nicotine consumption. In the developing brain of PSH rats, no changes were found in the activity of choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) or disturbances in the acetylcholine levels. However, decreased chrna4 expression was detected on the day 15 of pregnancy, while elevation in the chrna7 expression was observed on the days 15 and 16 of embryogenesis. In adulthood, the consequences of PSH were manifested as decreased expression of chrna4 in the medial prefrontal cortex (PFC), nucleus accumbens (NAcc), and hypothalamus (HT), decreased expression of chrna7 in the PFC and hippocampus (HPC). Whereas, nicotine consumption did not decrease the expression levels of chrna4 and chrna7 compared to the control group in the adult PSH rats. Thus, prenatal hypoxia predisposes to impaired expression of the chrna4 and chrna7 genes in adult rats without affecting acetylcholine metabolism during embryonic development.

The studying the role and condition of small extracellular vesicles (sEV) in mental and addictive disorders is an extremely promising area. SEV contain proteins on the membrane that protect against destruction by their own immunity, and due to their size, they are able to cross the blood-brain barrier. These properties make it possible to consider sEV as potential biomarkers reflecting the processes occurring in the brain, and at the same time available for study in peripheral blood samples. Studies have shown that the amount, biogenesis and contents of explosives change significantly when exposed to psychoactive substances both in vitro and in vivo. The results of the analysis of modern literature demonstrate the presence of numerous potential markers of addictive pathology among the loads carried by sEV, nevertheless, the real diagnostic significance of each of them requires to be studied. Many data indicate the effect of psychoactive substances on GTPases of the Rab family, Toll-like receptors, the complement system and cytokines. Also, in several studies, sex differences in sEV changes were found in response to substance exposure. Most studies indicate the involvement of sEV in the regulation of neuroinflammatory processes, interaction between glial cells and neurons, as well as between peripheral cells and cells of the central nervous system. The authors of the review formulated a hypothesis about the presence of two mechanisms-stages in which sEV is involved: “fast” – in response to the effects of substances, providing neuroplasticity, and “slow” – the result of impaired biogenesis of sEV and the appearance of aberrant vesicle variants.

Over the past decade, liquid biopsy (LB) has become a routine diagnostic test essential for the treatment of malignant tumors of various localizations. Its capabilities include early diagnosis, molecular genotyping, prognosis, prediction, and monitoring of tumor response. Typically, liquid biopsy involves the extraction of a single type of tumor-derived molecules or cellular elements from blood and subsequent molecular analysis. These elements may include circulating tumor DNA (ctDNA), circulating tumor cells (CTCs), circulating RNA (ctRNA), or the contents of extracellular vesicles (exosomes). Despite the technical sophistication of molecular analysis methods for circulating biomarkers, this diagnostic approach has limited relevance. In a significant proportion of cancer patients (ranging from 10 to 50%, depending on the tumor type), none of these analytes can be detected and analyzed, despite the presence of large, progressing neoplastic foci in the body. It seems reasonable to posit that heterogeneous fractions of circulating tumor-specific biomarkers complement each other, thus, the simultaneous analysis of several fractions will not only increase the sensitivity of the method but also more accurately characterize and predict the clinical situation. This review examines the possibilities and advantages of applying a combined multiparametric approach to liquid biopsy, which involves testing multiple circulating analytes in a single blood sample.

Fluorescently labeled and conjugated (strept)avidin is widely used for imaging of biotinylated molecules in immunological assays and histochemistry. The presented article shows that in addition to biotin, these proteins bind a number of glycans, including fragments of glycoprotein and glycolipid chains of mammals, in particular, antigens of the ABO blood system, oligolactosamines, 6-O-sulfated oligosaccharides. This interaction is inhibited in a dose-dependent manner by glycans in a form of polymeric (but not monomeric) conjugates at the micromolar concentration level, i.e. requires polyvalence. Taking into account the cluster organization of cell glycans (glycoproteins and glycolipids), when analyzing objects containing carbohydrates, this property is a potential source of error, that can be prevented by avoiding a large excess of (strept)avidin in the analytical system.

To prepare a safe cellular system for testing inhibitors targeting the RNA-dependent RNA polymerase (RdRp) of SARS-CoV-2, a genetic construct containing viral cDNA with two blocks of reporter genes while lacking genes encoding the structural S, E and M proteins was engineered. The first reporter block, consisting of renilla luciferase and green fluorescent protein (Rluc-GFP), located upstream of the SARS-CoV-2 5′-UTR. Meanwhile, the second block, represented by firefly luciferase and red fluorescent protein (Fluc-RFP), was positioned downstream of the transcription regulatory sequence (TRS-N). Although the first block of reporter genes can be transcribed by both viral RdRp and cellular polymerases, the second block can only be transcribed by the viral polymerase, aligning with the Coronaviridae discontinuous transcription mechanism. This allowed us to accurately assess the effectiveness of viral RdRp inhibition. To facilitate the search for nucleoside RdRp inhibitors the cell line was obtained expressing herpes simplex virus thymidine kinase which provides the first stage of nucleoside phosphorylation. When screening the ability of a number of compounds to inhibit the catalytic activity of SARS-CoV-2 RdRp, we first discovered the antiviral activity of 2′-amino2′-deoxyadenosine and adenosine-N1-oxide, exceeding the activity of molnupiravir, a therapeutic agent used in the treatment of COVID-19.

The C3f peptide is a by-product of the regulation of the activated complement system with no firmly established function of its own. We have previously shown that C3f exhibits moderate antimicrobial activity against some Gram-positive bacteria in vitro. The occurrence of two histidine residues in the amino acid sequence of the peptide suggested an enhancement of its antimicrobial activity at lower pH and in the presence of metal cations, particularly zinc cations. Since such conditions can be realized in inflammatory foci, the study of the dependence of C3f activity on pH and the presence of metal cations provides an opportunity to assess the biological significance of the antimicrobial properties of the peptide. The peptide C3f and its analogs with histidine substitutions by lysines or serines, C3f[H/K] and C3f[H/S], were prepared by solid-phase synthesis. Using CD spectroscopy, we found that C3f contained a β-hairpin and unstructured regions; the presence of Zn2+ did not affect the conformation of the peptide. In the present work, it was shown that C3f can also exhibit antimicrobial activity against Gram-negative bacteria, in particular, Pseudomonas aeruginosa ATCC 27583. The action of the peptide on Ps. aeruginosa and Listeria monocytogenes EGD is accompanied by impairment of the barrier function of bacterial membranes. Zn²⁺ ions, unlike Cu²⁺ ions, enhanced the antimicrobial activity of C3f against L. monocytogenes, with 4- and 8-fold molar excess of Zn²⁺ being no more effective than a 20% excess. The activity of the C3f analogs was also enhanced to some extent by zinc ions. Thus, we hypothesize a histidine-independent formation of C3f–Zn²⁺ complexes leading to an increase in the total charge and antimicrobial activity of the peptide. In the presence of 0.15 M NaCl, C3f lost its activity regardless of the presence of Zn²⁺, indicating a minor role of C3f as an endogenous antimicrobial peptide. The presence of C3f abolished the bactericidal effect of Zn²⁺ against the zinc-sensitive Escherichia coli strain ESBL 521/17, indirectly confirming the interaction of the peptide with Zn²⁺. The activity of C3f against Micrococcus luteus A270, but not against L. monocytogenes, increased with decreasing pH. In this work, we show the significance of factors such as pH and metal cations in realizing the activity of antimicrobial peptides based on the example of C3f.