Vol 88, No 2 (2023)

Single-cell RNA sequencing (scRNA-seq) is a revolutionary tool for studying the physiology of normal and pathologically altered tissues. This approach provides information about the molecular features (gene expression, mutations, chromatin accessibility, etc.) of cells, opens up the possibility to analyze cell differentiation trajectories/phylogeny and cell-cell interactions and allows discovering new cell types and previously unexplored processes. From a clinical point of view, scRNA-seq allows a deeper and more detailed analysis of the molecular mechanisms of various diseases and serves as the basis for the development of new preventive, diagnostic and therapeutic solutions. This review describes the different approaches to analysis of scRNA-seq data, reviews the strengths and weaknesses of bioinformatic tools, provides recommendations and examples of their successful use and suggests potential directions for improvement. It also emphasizes the need to create new, including multi-omics, protocols for the preparation of DNA/RNA libraries of single cells in order to obtain a more complete and systematic understanding of each cell.

A novel donepezil-caffeic acid (DP-CA) hybrid molecule was designed, synthesis, and investigated by molecular modeling. Its biological activity and protective effect were investigated by the IR spectroscopy, ¹H and ¹³C NMR spectroscopy, and mass spectrometry. DP-CA was highly active against acetylcholine esterase and inhibited it at the micromolar concentrations. Fluorescence and UV-Vis spectroscopy studies showed strong binding of DP-CA to DNA. Moreover, DP-CA exhibited protective effects against H₂O₂-induced toxicity in U-118 MG glioblastoma cells. Finally, molecular docking showed a high affinity of DP-CA in all concentrations, and the active 4EY7 site exhibited essential residues with polar and apolar contacts. Taken together, these findings indicate that DP-CA could be a prospective multifunctional agent for the treatment of neurodegenerative diseases.

Numerous studies have shown that various adverse factors of different nature and action mechanisms have similar negative influence on placental angiogenesis, resulting in insufficiency of placental blood supply. One of the risk factors for pregnancy complications with placental etiology is an increased level of homocysteine in the blood of pregnant women. However, the effect of hyperhomocysteinemia (HHcy) on the development of the placenta and, in particular, on the formation of its vascular network is at present poorly understood. The aim of this work was to study the effect of maternal HHcy on the expression of angiogenic and growth factors (VEGF-A, MMP-2, VEGF-B, BDNF, NGF), as well as their receptors (VEGFR-2, TrkB, p75NTR), in the rat placenta. The effects of HHcy were studied in the morphologically and functionally different maternal and fetal parts of the placenta on the 14th and 20th day of pregnancy. The maternal HHcy caused increase in the levels of oxidative stress and apoptosis markers accompanied by an imbalance of the studied angiogenic and growth factors in the maternal and/or fetal part of the placenta. The influence of maternal HHcy in most cases manifested in a decrease in the protein content (VEGF-A), enzymatic activity (MMP-2), gene expression (VEGFB, NGF, TRKB), and accumulation of precursor form (proBDNF) of the studied factors. In some cases, the effects of HHcy differed depending on the placental part and stage of development. The influence of maternal HHcy on signaling pathways and processes controlled by the studied angiogenic and growth factors could lead to incomplete development of the placental vasculature and decrease in the placental transport, resulting in fetal growth restriction and impaired fetal brain development.

Age-related macular degeneration (AMD) is a complex neurodegenerative disease that is a major cause of irreversible visual impairment in developed countries. Although age is the greatest risk factor for AMD, molecular explanations of this clinical observation are not known. Growing evidence shows that dysregulation of MAPK pathways contributes to aging and neurodegenerative diseases; however, information about the upregulation of MAPKs in this context is still controversial. Among these kinases, ERK1 and ERK2 participate in the maintenance of proteostasis through the regulation of protein aggregation induced by endoplasmic-reticulum stress and other stress-mediated responses in the cell. Here, to assess the contribution of alterations of MEK1/2-ERK1/2 signaling-pathway activity to the development of AMD, we compared its changes with age in the retina of control (Wistar) rats and OXYS rats, which develop AMD-like retinopathy spontaneously. We showed that ERK1/2 signaling-pathway activity increases during physiological aging in the Wistar retina. The manifestation and dramatic progression of AMD-like pathology in OXYS rats co-occurred with hyperphosphorylation of ERK1/2 and MEK1/2 as key ERK1/2 signaling-pathway kinases in the retina. Besides, progression of the retinopathy was accompanied by ERK1/2-dependent tau protein hyperphosphorylation and enhancement of ERK1/2-dependent phosphorylation of CryaB at Ser45 in the retina.

Exposure to paraoxon (POX) and leptin (LP) could cause an imbalance between oxidants and antioxidants in an organism, which can be prevented by introduction of exogenous antioxidants such as N-acetylcysteine (NAC). The aim of this study was to evaluate synergic or additive effects of administration of exogenous LP plus POX on the antioxidant status, as well as the prophylactic and therapeutic roles of NAC in various rat tissues. Fifty-four male Wistar rats were divided into nine groups treated with different compounds: Control (no treatment), POX (0.7 mg/kg), NAC (160 mg/kg), LP (1 mg/kg), POX + LP, NAC-POX, POX-NAC, NAC-POX + LP, and POX + LP-NAC. In the last five groups, only the order of administered compounds differed. After 24 h, plasma and tissues were sampled and examined. The results showed that administration of POX plus LP significantly increased biochemical indices in plasma and antioxidant enzymes activities and decreased glutathione content in the liver, erythrocytes, brain, kidney, and heart. In addition, cholinesterase and paraoxonase 1 activities in the POX + LP-treated group were decreased and malondialdehyde level was increased in the liver, erythrocytes, and brain. However, administration of NAC rectified induced changes although not to the same extent. Our study suggests that POX or LP administration engage the oxidative stress system per se; however, their combination did not produce significantly greater effects. Moreover, both prophylactic and therapeutic treatments of rats with NAC supported the antioxidant defense against oxidative damage in tissues, most probably through both its free radical scavenging ability and maintaining intracellular GSH levels. It can therefore be suggested that NAC has particularly protective effects against POX or/and LP toxicity.

Medicinal plants and their therapeutically promising chemical compounds belonging to the valued category of ‘traditional medicine’ are potential remedies for various health problems. Due to their complex structure and enormous health benefits, the high-value plant-derived metabolites collectively termed as ‘phytochemicals’ have emerged as a crucial source for novel drug discovery and development. Indeed, several medicinal plants from diverse habitats are still in the ‘underexplored’ category in terms of their bioactive principles and therapeutic potential. COVID-19, infection caused by the SARS-CoV-2, first reported in November 2019, resulted in the alarming number of deaths (6.61 million), was further declared ‘pandemic’, and spread of the disease has continued till today. Even though the well-established scientific world has successfully implemented vaccines against COVID-19 within the short period of time, the focus on alternative remedies for long-term symptom management and immunity boosting have been increased. At this point, interventions based on traditional medicine, which include medicinal plants, their bioactive metabolites, extracts and formulations, attracted a lot of attention as alternative solutions for COVID-19 management. Here, we reviewed the recent research findings related to the effectiveness of phytochemicals in treatment or prevention of COVID-19. Furthermore, the literature regarding the mechanisms behind the preventive or therapeutic effects of these natural phytochemicals were also discussed. In conclusion, we suggest that the active plant-derived components could be used alone or in combination as an alternative solution for the management of SARS-CoV-2 infection. Moreover, the structure of these natural productomes may lead to the emergence of new prophylactic strategies for SARS-CoV-2-caused infection.

При изучении возрастной динамики смертности людей необходима осторожность в использовании когортных данных, поскольку смертность зависит не только от возраста, но и от меняющихся со временем условий жизни. Для дальнейшей проверки предложена гипотеза о том, что актуарная скорость старения может даже снижаться в более современных когортах людей благодаря улучшению условий жизни.