Aleksey A. Ustyugov

Introduction: The structure-property relationship of drug candidates determines their transport to target organs and is used as a tool to design drugs with optimal properties and minimal undesirable effects. The effects of fluorinated derivatives of gamma-carboline on the formation of cytosolic aggregates of the FUS protein and the relationships among structure, physicochemical characteristics, and anti-aggregation properties were studied. Methods: The effect of the compounds on FUS protein aggregation in SH-SY5Y cells was evaluated using confocal fluorescence microscopy. Partition coefficients were determined using the isothermal saturation method, and all descriptors were calculated with a software package. Results: A series of fluorinated γ‑carboline derivatives was synthesized and demonstrated the ability to reduce pathological FUS protein aggregation in a cellular model of proteinopathy. The influence of substituents on the distribution coefficients of the studied compounds was revealed. Among the most active compounds, this study highlights DF-302 and DF-402, which feature a methyl group and a trifluoromethyl group on the pyridinium fragment, respectively. Discussion: The structure-activity relationships for the inhibition of FUS protein aggregation by fluorinated γ-carbolines were analyzed in relation to their physicochemical properties. A linear correlation was observed between the anti-aggregation efficacy and the total hydrogen bond acceptor capacity: as the compound's propensity to form hydrogen bonds with the FUS protein increased, its ability to prevent large aggregate formation in cells decreased. An assumption has been made that off-target interactions of the studied compounds with membrane proteins increase with their hydrogen bond acceptor capacity. This effect can limit compounds' availability to influence the processes of cytosolic FUS protein aggregates. Conclusion: The positive correlation of lipophilicity with FUS aggregate reduction underscores the role of cellular penetration in the anti-aggregation effect. Conversely, the negative correlation with hydrogen-bond acceptor capacity suggests that off-target interactions with membrane proteins may compete with binding to FUS aggregates.

Wavelet analysis is a powerful tool for studying behaviors across scales and timing. We used it to analyze spontaneous motor activity in 3-month-old 5xFAD mice and their wild-type littermates, focusing on sex and genotype differences. Mice were placed in home cages 24 hours before recording, and their movements generated oscillations in the environment, which were recorded and analyzed using wavelet transforms. Initially, there were no differences in activity between transgenic and non-transgenic mice for either sex. However, after eight hours, male transgenic mice showed significant differences, lasting from 64 to 256 minutes, while females exhibited disparities after twelve hours, with events lasting 32 to 128 minutes. Transgenic mice had lower interaction levels with their environment during the second half of the experiment. These findings suggest that genotype influences spontaneous motor activity, aligning with human data and supporting the use of non-invasive methods to assess pathology severity and therapeutic efficacy in preclinical studies. Detecting frequency and timing discrepancies between transgenic and non-transgenic animals provides valuable diagnostic insights.

Alzheimer’s disease is a progressive neurodegenerative disorder characterized by mitochondria dysfunction, accumulation of beta-amyloid plaques, and hyperphosphorylated tau tangles in the brain leading to memory loss and cognitive deficits. There is currently no cure for this condition, but the potential of stem cells for the therapy of neurodegenerative pathologies is actively being researched. This review discusses preclinical and clinical studies that have used mouse models and human patients to investigate the use of novel types of stem cell treatment approaches. The findings provide valuable insights into the applications of stem cell-based therapies and include the use of neural, glial, mesenchymal, embryonic, and induced pluripotent stem cells. We cover current studies on stem cell replacement therapy where cells can functionally integrate into neural networks, replace damaged neurons, and strengthen impaired synaptic circuits in the brain. We address the paracrine action of stem cells acting via secreted factors to induce neuroregeneration and modify inflammatory responses. We focus on the neuroprotective functions of exosomes as well as their neurogenic and synaptogenic effects. We look into the shuttling of mitochondria through tunneling nanotubes that enables the transfer of healthy mitochondria by restoring the normal functioning of damaged cells, improving their metabolism, and reducing the level of apoptosis.

INTRODUCTION. Stem cell therapy is a promising treatment method for various diseases and injuries, but its safety has yet to be determined. Therefore, studying the safety of administering a xenogeneic cell-based medicinal product (CBMP) into the retro-orbital venous sinus is essential for developing protocols for further studies of potential medicinal products for neurological conditions.AIM. The aim of the study was to determine the optimal dose of a CBMP derived from glial progenitor cells (GPCs) and to evaluate its safety during retrobulbar administration in C57BL/6J mice.MATERIALS AND METHODS. GPCs were derived from human induced pluripotent stem cells by stepwise differentiation and cultured in DMEM/F12 supplemented with epidermal growth factor and ciliary neurotrophic factor. Matrigel was used as a substrate. GPCs were injected into the retro-orbital venous sinus of male C57BL/6J mice under isoflurane anaesthesia once a week for two months. The study analysed changes in biochemical blood parameters and behaviour. The quantities of activated astrocytes and glial cells were determined by postmortem immunohistochemical staining.RESULTS. The administration of GPCs at a dose of 500×10³ cells/mouse, which was selected using literature data, induced an increase in the plasma levels of ala nine aminotransferase and aspartate aminotransferase. This could indicate cell damage and the development of inflammatory reactions. At doses reduced to one-third the initial GPC concentration or lower, the biochemical blood parameters of the treatment groups did not differ significantly from those of the control group. There were no significant differences in neuroinflammatory markers between the groups receiving GPCs at different doses, except for an increase in astrocyte activation at a dose of 150×10³ cells/mouse, which could potentially indicate inflammatory processes in the brain. The study detected no pathological changes in the brain or cell damage markers in the blood of mice after retrobulbar GPC injections of 15×10³ or 50×10³ cells/mouse.CONCLUSIONS. The study results indicate that long-term therapy with GPCs is potentially safe for mice if the dose is optimal. The authors suggest using the optimal doses and the administration route established in this study for further research into the safety of intravenous administration of CBMPs for neurological conditions.

Alzheimer’s disease is a neurodegenerative disease characterized by extracellular accumulation of β-amyloid and intracellular aggregation of hyperphosphorylated tau into neurofibrillary tangles in the brain. It leads to progressive memory impairment and loss of daily living skills. Currently, there is no effective treatment for this disease, but the potential of stem cells for the therapy of neurodegenerative pathologies, inclu­ding Alzheimer’s disease, is being actively explored. Stem cell-secreted growth factors, extracellular vesicles can attenuate neuroinflammation and slow down cognitive deterioration during disease progression. This review highlights progress in preclinical studies using mouse models of different stem cell types as treatment stra­tegies for Alzheimer’s disease and provides insights into their translational applications. The article reviews the benefits, therapeutic effects and prospects of stem cells and their differentiating descendants, and provides current information on the mechanisms by which different types of stem and pluripotent cells are involved endogenous neurogenesis in Alzheimer’s disease. The data presented in this review contain information on cell therapy methods, both those already used in clinical practice and those being studied in various models, including transgenic mice. In the future, effective methods of obtaining and delivering of stem cells and their pro­ducts to achieve significant clinical results in patients with Alzheimer’s disease will be developed.

Рассмотрены некоторые возможности создания оригинальных конъюгатов препарата «Рилузол» с ключевыми структурными фрагментами фармакологически активных веществ с целью получения новых мультитаргетных соединений, способных одновременно действовать на несколько мишеней, участвующих в процессе развития бокового амиотрофического склероза. Проведена оценка действия рилузола, его производных (конъюгатов с другими фармакофорными фрагментами) и биоизостерных аналогов на высвобождение и обратный захват нейромедиатора глутамата нервными окончаниями на модели фракции синаптосом Р2 радиолигандным методом. Методом фиксации напряжения было также изучено действие всех синтезированных соединений на потенциал-управляемые быстрые Na⁺-токи нейронов головного мозга млекопитающих. Результаты лазерной конфокальной микроскопии позволили получить информацию о состоянии патогенного белка. Показано, что конъюгаты рилузола с тремя нейроактивными фармакофорными структурами, а именно, диметиламиноадамантаном, фенотиазином и тетрагидро-гамма-карболином, в 2 – 3 раза снижают патологическую агрегацию белка FUS (коэффициент агрегации в диапазоне 28 – 46 %). Биохимический анализ накоплений патологической изоформы белка FUS после дифференциального ультрацентрифугирования позволил сделать заключение о том, что соединение ТГ-2253 в наибольшей степени приводит к накоплению меченого белка в цитоплазматической, а не в цитоскелетной фракции.

COVID‐19 is a systemic inflammatory disease initiated by SARS‐CoV‐2 virus infection. Multiple vaccines against the Wuhan variant of SARS‐CoV‐2 have been developed including a whole virion beta‐propiolactone‐inactivated vaccine based on the B.1.1 strain (CoviVac). Since most of the population has been vaccinated by targeting the original or early variants of SARS‐CoV‐2, the emergence of novel mutant variants raises concern over possible evasion of vaccine‐induced immune responses. Here, we report on the mechanism of protection by CoviVac, a whole virion‐based vaccine, against the Omicron variant. CoviVac‐immunized K18‐hACE2 Tg mice were protected against both prototype B.1.1 and BA.1‐like (Omicron) variants. Subsequently, vaccinated K18‐hACE2 Tg mice rapidly cleared the infection via cross‐reactive T‐cell responses and cross‐reactive, non‐neutralizing antibodies recognizing the Omicron variant Spike protein. Thus, our data indicate that efficient protection from SARS‐CoV‐2 variants can be achieved by the orchestrated action of cross‐reactive T cells and non‐neutralizing antibodies.

Currently, there are no effective drugs for the treatment of amyotrophic lateral sclerosis (ALS). Only two drugs—edaravone and riluzole—have been approved, but they have very limited efficacy. The aim of this work was to modify the structural core of the Edaravone—phenylpyrazolone moiety and combine it with aminoadamantane pharmacophore in order to expand the spectrum of its action to a number of processes involved in the pathogenesis of ALS. New conjugates of edaravone derivatives with 1-aminoadamantanes combined with alkylene or hydroxypropylene spacers were synthesized, and their biological activity was investigated. Compounds were found that could inhibit lipid peroxidation and calcium-related mitochondrial permeability, block fast sodium currents of CNS neurons, and reduce aggregation of the mutated form of the FUS-protein typical to ALS. So, the proposed modification of the edaravone molecule has allowed the obtaining of new original structures that combine some prospective therapeutic mechanisms against key chains of the pathogenesis of ALS. The identified lead compounds can be used for further optimization and development of new promising drugs on this basis for the treatment of ALS.

Proteasomes degrade most intracellular proteins. Several different forms of proteasomes are known. Little is known about the role of specific proteasome forms in the central nervous system (CNS). Inhibitors targeting different proteasome forms are used in clinical practice and were shown to modulate long-term potentiation (LTP) in hippocampal slices of untreated animals. Here, to address the role of non-constitutive proteasomes in hippocampal synaptic plasticity and reveal the consequences of their continuous inhibition, we studied the effect of chronic administration of the non-constitutive proteasome inhibitor ONX-0914 on the LTP induced by two different protocols: tetanic stimulation and theta-burst stimulation (TBS). Both the tetanus- and TBS-evoked potentiation contribute to the different forms of hippocampal-dependent memory and learning. Field-excitatory postsynaptic potentials (fEPSPs) in hippocampal slices from control animals and animals treated with DMSO or ONX-0914 were compared. LTP induced by the TBS was not affected by ONX-0914 administration; however, chronic injections of ONX-0914 led to a decrease in fEPSP slopes after tetanic stimulation. The observed effects correlated with differential expression of genes involved in synaptic plasticity, glutaminergic synapse, and synaptic signaling. Obtained results indicate that non-constitutive proteasomes are likely involved in the tetanus-evoked LTP, but not the LTP occurring after TBS, supporting the relevance and complexity of the role of specific proteasomes in synaptic plasticity, memory, and learning.