Astroglia, often called as astrocytes, play a crucial role in protecting neurons and preserved the neurophysiological functions. Astrocytes’ dysfunction contributes to numerous neurological disorders. Astrocytes are involved in the regulation of oxidative stress and inflammatory process within Central nervous system. Developments in specific transcriptomic and genomics have initiated the discovery of new mechanisms governing astrocyte during oxidative and inflammatory process. Despite the advancements in existing diagnostic and therapeutic methods like targeted ultrasound and NPs mediated administration, these methods still pose risks and have drawbacks. Aptamers, artificial single stranded oligonucleotides have the ability to specific target cells and exhibit strong binding affinity and enhance the administration of therapeutic agents. Research over the last few years has demonstrated that the ability to target specific molecules/intermediates such as reactive oxygen species, interleukins, tumor necrotic factor, vascular endothelial growth factor, brain-derived neurotrophic factor and penetrate the blood brain barrier makes aptamers ideal candidates for addressing the oxidative and inflammatory intermediaries within astrocytes. Present review explores the emerging applications of aptamers in cytoprotection specially focus on their potential to combat oxidative stress and inflammation in astrocytes. We also discuss the capability of aptamers as cell specific molecular probes for advancing tailored diagnostic and therapeutic interventions. Present article also addresses future directions and significant issues.

Cultured astrocytes were incubated with CuCl2, which caused dose-dependent cell death (25-200 μM, 24 h). Immunocytochemical detection of the nucleolar protein nucleophosmin/B23 (NPM/B23) demonstrated that exposure to Cu2+ (100 μM, 24 h) caused a significant increase in the surface area of NPM/B23 clusters, which was accompanied by the changes in the nucleolar ultrastructure characteristic of nucleolar stress. Longer incubation of astrocytes with Cu2+ (100 μM, 48 h) led to accumulation of the endoplasmic reticulum (ER) stress marker GRP78, which was accompanied by the increase in nucleolar size and migration of the nucleolar material into the nucleoplasm.

Copper-induced cell death (cuproptosis) is implicated in the pathogenesis of Wilson's disease, there-fore it is important to understand how copper ions can affect brain astrocytes, as these cells play an important role in copper metabolism. The cultured astrocytes were incubated with various concentra-tions of CuCl2 (0.025-0.2 mM) for 24 h. CuCl2 caused dose-dependent decrease in cell viability. Statistically significant decrease in cell viability (85 %) was detected at 0.05 mM Cu2+ . Higher con-centrations of copper (0.1 mM and 0.2 mM) reduced cell viability to 80 % and 59 %, respectively. The concentration 0.1 mM was used for further experiments. In the surviving cells treated with 24 h Cu2+ , there was a significant increase in the level of the p53 protein and changes in the localization of nucleophosmin/B23 in nuclei of cultured astrocytes, increase in the size of the nucleoli to 2.47 ± 0.1 µm2 compared to 1.35 ± 0.04 µm2 in the control and a decrease in the mitochondrial membrane potential. The electron microscopy showed that copper induced a redistribution of the dense fibrillar component to the nucleolar periphery and a disorganization of the whole nucleolar structure. Our results show that the nucleoli are one of the main targets of Cu-induced damage, leading to the development of nucleolar stress.

Introduction. Wilson–Konovalov disease is associated with impaired intracellular transport of Cu2+, resulting in increased concentrations of unbound copper in the blood, its accumulation in various organs and tissues, primarily the liver, brain, kidneys, and cornea. The resulting excess Cu2+ ions in the brain leads to altered astrocyte morphology, enlarged microglia, edema of oligodendroglia, reduced neuronal count, and impaired permeability of microcirculatory vessels. The study aimed to determine how Cu2+ excess affects angiogenesis and nucleoli in cultured rat cerebral cortex endothelial cells (ECs). Materials and methods. Copper chloride was added to the culture medium of rat cerebral cortex ECs at concentrations of 50–300 μM for 24 hours. Angiogenesis in cultures was studied using cultured rat brain ECs and the Angiogenesis Assay Kit. Cell viability was assessed using the MTT test, and nucleoli were stained with acridine orange. Results. The effect of Cu2+ on cultured rat cerebral cortex ECs was examined. MTT assay of cultures showed reduced formazan production starting at Cu2+ concentrations of 100 μM in the culture medium, indicating decreased cell viability. At this same concentration, Cu2+ -induced impairment of angiogenesis was observed in EC cultures. At higher Cu2+ concentrations (200 μM), surviving cells exhibited a statistically significant increase in nucleolar size to 1.71 ± 0.09 μm2 compared to 1.33 ± 0.07 μm2 in control cultures. Conclusion. Thus, excess copper ions reduce angiogenesis and induce changes in ECs nucleoli, which may represent a universal cellular response associated with cell damage.

The number of microglia cells and astrocytes in layer V of the cerebral cortex was estimated on day 7 after damage caused by a unilateral focal traumatic brain injury of the left hemisphere sensorimotor cortex. Quantitative assessment was performed by counting immunocytochemically stained microglia cells (Iba1 marker) and activated astrocytes (GFAP) at different distances from the lesion site. Activation of microglial and astroglial cells was observed not only in the marginal zone of the lesion of the left hemisphere, but also in the intact hemisphere. The data obtained indicate the dissemination of inflammation in focal traumatic brain injury.

Mitochondrial dysmorphology/dysfunction follow global cerebral ischemia-reperfusion (GCI/R) injury, leading to neuronal death. Our previous researches demonstrated that Levodopa (L-DOPA) improves learning and memory impairment in GCI/R rats by increasing synaptic plasticity of hippocampal neurons. This study investigates if L-DOPA, used in Parkinson's disease treatment, alleviates GCI/R-induced cell death by enhancing mitochondrial quality. Metabolomics and transcriptomic results showed that GCI/R damage affected the Tricarboxylic acid (TCA) cycle in the hippocampus. The results of this study show that L-DOPA stabilized mitochondrial membrane potential and ultrastructure in hippocampus of GCI/R rats, increased dopamine level in hippocampus, decreased succinic acid level, and stabilized Ca2+ level in CA1 subregion of hippocampus. As a precursor of dopamine, L-DOPA is presumed to improves mitochondrial function in hippocampus of GCI/R rats. However, dopamine cannot cross the blood-brain barrier, so L-DOPA is used in clinical therapy to supplement dopamine. In this investigation, OGD/R models were established in isolated mouse hippocampal neurons (HT22) and primary rat hippocampal neurons. Notably, dopamine exhibited a multifaceted impact, demonstrating inhibition of mitochondrial reactive oxygen species (mitoROS) production, stabilization of mitochondrial membrane potential and Ca2+ level, facilitation of TCA circulation, promotion of aerobic respiratory metabolism, and downregulation of succinic acid-related gene expression. Consistency between in vitro and in vivo results underscores dopamine's significant neuroprotective role in mitigating mitochondrial dysfunction following global cerebral hypoxia and ischemia injury. Supplement dopamine may represent a promising therapy to the cognitive impairment caused by GCI/R injury.

We studied the effect of extracellular acidosis, cysteine, glutathione, and iron ions (Fe3+) on the neurocytotoxic effect of copper ions (Cu2+) in vitro. At acidic pH of the culture medium (pH 6.8), the toxic effect of copper on cultured neurons significantly increased in comparison with that at neutral pH 7.3. In the presence of 25 μM Cu2+ in the culture medium at pH 7.3 and 6.8, the neuronal survival was 89±2 and 63±4

Neurodegenerative disorders are difficult to treat because of this natural barrier in the brain. Moreover, neurovascular units seem to be essential targets/mediators of the nervous system cytoprotective effects. Functionalized nanomaterials have gained significant prominence in the medical domain due to their extensive utilization in targeted drug delivery and therapeutics within the neurovascular system. Their remarkable potential in neurovascular therapy has been demonstrated, highlighting their effectiveness in this field. A systematic summary of the specific applications and limitations of functionalized nanomaterials in the targeted delivery system is essential for developing smart therapies to overcome the gaps in neurovascular therapy for the treatment of neurological disorders. The objective of present article was to highlight the advancements in recent therapies support the potential role of functionalized nanomaterials to tackle the difficulties in targeted delivery systems for neurodegenerative disorders. We review the role of functionalized nanomaterials as therapeutics within the neurovascular units and their potential to lead to more sophisticated and smart treatment techniques despite some obstacles, given to the patients of neurological disorders, particularly when paired with multimodal drugs who are likely to benefit from cytoprotection. This review also addresses the current understanding, gaps, and issues to be resolved.

Traumatic brain injury (TBI) and brain ischemia/reperfusion cause neurodegenerative processes that can continue after the acute stage with the development of severe brain atrophy with dementia. In this case, the long-term neurodegeneration of the brain is similar to the neurodegeneration characteristic of Alzheimer's disease (AD) and is associated with the accumulation of beta amyloid and tau protein. In the pathogenesis of AD as well as in the pathogenesis of cerebral ischemia and TBI oxidative stress, progressive inflammation, glial activation, blood-brain barrier dysfunction, and excessive activation of autophagy are involved, which implies the presence of many targets that can be affected by neuroprotectors. That is, multivariate cascades of nerve tissue damage represent many potential targets for therapeutic interventions. One of such substances that can be used in multi-purpose therapeutic strategies is methylene blue (MB). This drug can have an antiapoptotic and anti-inflammatory effect, activate autophagy, inhibit the aggregation of proteins with an irregular shape, inhibit NO synthase, and bypass impaired electron transfer in the respiratory chain of mitochondria. MB is a well-described treatment for methemoglobinemia, malaria, and encephalopathy caused by ifosfamide. In recent years, this drug has attracted great interest as a potential treatment for a number of neurodegenerative disorders, including the effects of TBI, ischemia, and AD.

Oxidative stress is one of the main pathogenic factors of neuron damage in neurodegenerative processes; this makes it an important therapeutic target to which the action of neuroprotectors should be directed. One of these drugs is thymoquinone. According to modern data, this substance has a wide range of pharmacological activity, including neuroprotective, which was demonstrated in experimental modeling of various neurodegenerative diseases and pathological conditions of the brain. The neuroprotective effect of thymoquinone is largely due to its antioxidant ability. Currently available data show that thymoquinone is an effective means to reduce the negative consequences of acute and chronic forms of cerebral pathology, leading to the normalization of the content of antioxidant enzymes and preventing an increase in the level of lipid peroxidation products. Antioxidant properties make this substance a promising basis for the development of prototypes of therapeutic agents aimed at the treatment of a number of degenerative diseases of the central nervous system.

Introduction. Copper ions (Cu2+) are structural elements of proteins such as cytochrome с oxidase (Complex IV), an enzyme that catalyzes the final step of electron transfer to oxygen during oxidative phosphorylation in the mitochondria. With Cu2+ homeostasis being of utmost importance, its disturbances in the central nervous system are involved in the mechanisms of many neurodegenerative and other brain disorders. This study aimed to assess the effects of non-toxic copper ion levels on death of cerebellar granule neurons associated with lipopolysaccharide (LPS; in vitro inflammation model) or azide sodium (NaN3; cytochrome с oxidase inhibitor). Materials and methods. LPS (10 μg/mL) or NaN3 (250 μM) was added on day 7 to 8 to the culture medium with rat cerebellar cells for 24 hours in vitro. Nitrite concentrations were measured in the culture medium by Griess assay; absorbance was recorded with a spectrophotometer at 540 nm, and morphologically intact cells were counted as survived neurons. Results. Added to the culture medium, LPS or NaN3 reduced neuron survival to 15 ± 2% or 20 ± 3% vs. control, respectively. Cu2+ (0.5 to 5.0 μM) increased neuron survival in a dose-dependent manner to 78 ± 4% with toxic levels of LPS and to 86 ± 6% with NaN3 with 5 μM Cu2+. The concentration of nitrites in the control culture medium was 2.0 ± 0.2 μM. Added to the cell cultures, LPS increased the concentration of nitrites to 8.5 ± 0.5 μM. Cu2+ 5 μM did not show any significant effects on nitrite accumulation in the culture medium. Conclusions. We showed that copper ions can exert protective effects on neurons against LPS-induced or NaN3-induced toxicity. This protection is likely to be associated rather with Cu2+ interaction with Complex IV of the electron transfer chain in the mitochondria than with inhibition of NO production. Effects of Cu2+ on apoptosis pathway proteins also cannot be ruled out.

Introduction. Oxidative stress is an important pathogenic factor in cerebral ischemia, which occupies one of the leading places among various forms of cerebral pathology in mortality and disability of the working-age population and is recognized as an actual problem of experimental and clinical neurology. Naturally, modeling of neurodestructive processes and their correction under the action of oxidative stress in vitro contributes to the study of protective mechanisms that counteract ischemic damage of neurons. Objective. To reveal the influence of chemical preconditioning induced by transient inhibition of Na+/K+-ATPase activity on tolerance of cultured cerebellar granule neurons to oxidative stress at different stages of their differentiation in vitro. Materials and methods. The activity of Na+/K+-ATPase was inhibited with ouabain, which was added at 34 and 78 days in vitro to cerebellar cell cultures of 7-day rats at a concentration of 0.1 mM for 24 hours before induction of oxidative stress by hydrogen peroxide (0.05 and 0.075 mM, 4 hours) or paraquat (0.15 and 0.2 mM, 24 hours). Results. Oxidative stress induced by paraquat causes the most pronounced death of cultured granular neurons in immature (34 days) cultures, in which survival was 442,5% of neurons, compared to mature (78 days) cultures, in which survival was 615,4%. Pretreatment of cultures with ouabain has a protective effect, the most significant in mature cultures. The exposure of mature cultures with hydrogen peroxide kills more than 90% of neurons, whereas pretreatment with ouabain increases the survival rate by 44%. At the same time in the immature cultures the damaging effects of H2O2 and the protective effect of ouabain is less pronounced. Conclusion. The increased tolerance of cultured cerebellar granule cells to oxidative stress after transient inhibition of Na+/K+-ATPase activity by ouabain is shown. The direct dependence of the efficiency of the ouabain protection on the degree of neuronal morphochemical differentiation in vitro is revealed.

Mitophagy is the selective degradation of mitochondria by autophagy. This process is considered to be one of the stages of mitochondrial quality control, as a result of which damaged depolarized mitochondria are eliminated, thus limiting the formation of reactive oxygen species and the release of apoptogenic factors. Selective degradation of mitochondria by autophagy is one of the main ways to protect cells from cadmium toxicity, which results in dysfunction of the mitochondrial electron transport chain, leading to electron leakage, production of reactive oxygen species and cells death. However, excessive autophagy can be dangerous for cells. Currently, the participation of cadmium ions in normal physiological processes has not been detected. Zn2+, unlike Cd2+, regulate the activity of a large number of functionally important proteins, including transcription factors, enzymes, and adapters. It has been shown that Zn2+ not only participate in autophagy, but are also crucial for basal or induced autophagy. It is likely that zinc drugs can be used to reduce the cadmium toxicity and in the regulation of mithophagy.

Methylene blue (MB) can be used as a multidirectional neuroprotector to stop the development of multiple cascades of neuron damage during neurodegenerative processes. This study assesses a protective effect of MB, using an experimental simulation of sporadic Alzheimer's disease by intracerebroventricular administration of streptozotocin (STZ) in rats. It was found that a STZ-induced impairment of memory can be partially mitigated with intravenous injections of MB after the administration of STZ. The treatment of animals with MB prevented the STZ-induced increase in the number and density of microglial and GFAP-positive cells in the brain cortex. In addition, it was shown that the expression of the LC3B protein, an indicator of autophagy, increases in the hippocampus of animals treated with STZ. In the hippocampus of animals treated with MB, an increase in the expression of the LC3B protein was prevented. Using the Griess reaction assay and immunocytochemical study was found that MB reduces lipopolysaccharide-induced NO-production and the expression of iNOS in cultured neurons. In conclusion, our data demonstrate that MB has neuroprotective and anti-inflammatory effects and is able to prevent autophagy. These effects have important therapeutic implications, so MB could potentially play a role in the treatment of neurodegenerative processes.

A close relationship between the brain capillaries and thefunctional load of neurons and glial cells allows considering themas a single structural and functional complex, a neurovascular unit (NVU).The effects of lipopolysaccharide (LPS, 5–30 µg/mL, 24h) on nitricoxide (NO) production and of menadione (5–50 µM, 24 h) on cell viabilityin cultures of granule neurons, cerebrovascular endothelial cellsand astrocytes, as well as the state of mitochondria (Mt) in differentNVU cell types, were assessed. It was found that the applicationof 5 µg/mL of LPS caused an intense NO production in cell cultures.The largest effect was shown for astrocytes, in which LPS causeda significant increase in NO production by more than 8-fold. Incultures of granule neurons, this exposure caused an almost 5-foldincrease in NO production. The weakest response to the stimulationof NO production was shown for endotheliocytes, 1.7-fold. To induceoxidative damage, menadione was introduced into a culture medium.In neuronal cultures, 10 µM of menadione was already enough to causecomplete death of granule neurons. Damage to endotheliocytes andastrocytes was only observed when the menadione concentration increasedup to 50 µM. Since menadione-induced oxidative stress is mediatedby mitochondria, the state of the Mt was assessed in intact cells.In astrocytes and endotheliocytes, Mt were numerous and representedlong curved strands, whereas in granule neurons, these organellesare much smaller in size and have a rounded shape. Thus, in theNVU, astrocytes are the main NO producers during neuroinflammation,while neurons are the most sensitive to oxidative stress despiterelatively poor development of the mitochondrial network; cerebrovascularendothelial cells demonstrated a minimum contribution to NO production.

Background: Cadmium is a highly toxic heavy metal that is capable of accumulating in the body and causing neurodegeneration. However, the effect of other trace elements on Cd2+ toxicity is currently poorly understood. The aim of this work was to study the effect of Zn2+ and Cu2+ ions on cadmium-induced death of neurons in the cerebral cortex. Methods: The work was performed on rat cortical primary cultures. The MTT test was used to determine the cytotoxicity effects. Analysis of intracellular Ca2+ concentration was assessed by the Fluo-4 AM calcium indicator that exhibit an increase in fluorescence upon binding Ca2+. MitoSOX Red (mitochondrial superoxide indicator) was used to measuring mitochondrial ROS content in live cells. Results: In this article, we show that the administration of CdCl2 (0.005-0.02 mM) for 48 h induced an increase in dose-dependent death rate of cultured cortical neurons. Mature neurons were more sensitive to the damaging effects of Cd2+ than immature ones. ZnCl2 (0.01-0.03 mM) significantly protected neurons from this toxic effect. In contrast to ZnCl2, CuCl2 (0.01 mM) increased cadmium neurotoxicity. Using Fluo-4 AM, measurements of intracellular calcium ions demonstrated that 24 h-exposure to Cd2+ induced intensive increase in Fluo-4 fluorescence in neurons, which was significantly reduced by zinc ions. CuCl2 increased the cadmium-induced Fluo-4 and MitoSOX Red fluorescence in neurons. The chelator of intracellular Ca2+ BAPTA significantly decreased Cd2+-induced intensive increase in Fluo-4 fluorescence in cells. Conclusion: The data obtained by us indicate that Zn2+ and Cu2+ can affect the neurotoxicity of cadmium in different directions: Zn2+ weaken the violation of intracellular calcium homeostasis caused by cadmium, preventing cell death, while Cu2+ potentiate the increase in the level of free intracellular calcium induced by cadmium and the development of mitochondrial dysfunction with an increase in the production of free radicals in differentiated cultured neurons of the cerebral cortex, which ultimately stimulates cytotoxicity.

Addition of 0.07 mM zinc ions to the culture medium induced death of cerebellar granule neurons. This was preceded by a decrease in intracellular pH by 0.86±0.12 and an increase in the level of intracellular zinc registered by increasing fluorescence of FluoZin3. However, intracellular acidosis caused by acidification of the culture medium to pH 6.0 was not toxic to neurons, and even significantly increased their survival under the action of zinc ions. In general, the overload of the neurons cytoplasm with zinc ions causes acidification of the cytoplasm, which is probably associated with the activation of Zn2+/H+ exchangers and is a protective mechanism for the neurocytotoxic effect of zinc ions.

We found that in the in vitro model of Alzheimer's type neurodegeneration based on the toxic action of beta-amyloid on cultured brain cells, the presence of lactate in the extracellular space in a dose-dependent manner reduces mitochondrial activity in brain microvessel endothelial cells. Lactate monocarboxylate transporter (MCT) blockade has the same effect, but the stimulation of lactate GPR81 receptors on the plasma membrane of these cells increases mitochondrial activity. This suggests that a high extracellular lactate concentration inhibits mitochondrial activity in endothelial cells, but not due to the action on GPR81 receptors. Most likely, the effects of GPR81 are significant in the presence of lower extracellular lactate concentrations. Since the development of Alzheimer's disease is known to be accompanied by a decreased expression of MCT isoforms that determine lactate transport and metabolism in brain cells, our data indicate that MCT dysregulation in Alzheimer's disease promotes the development of mitochondrial dysfunction, while the reproduction of the effects of extracellular lactate through activation of GPR81 receptors partially compensates for such alterations.

Introduction. Current demographic situation in Russia is characterized by decreasing birth rate. According to the World Health Organization, percentage of child-free marriages in various countries is 10–15 %. In Russia, the National Medical Research Center for Obstetrics, Gynecology, and Perinatology named after Academician V.I. Kulakov states that this number is 17 %. More than 4 million men suffer from infertility of various types. In recent years, pathologies of male reproductive function have achieved medical and social significance due to progressively decreasing sperm fertility. Fertility disorders are considered multi-factor conditions caused by internal and external factors and leading to pathological changes in sex organs. Correction of pathologies of male fertility does not always lead to positive results. Therefore, it is important to develop and study effective pharmaceuticals affecting the main fertility parameters.The study objective is to investigate the effect of various biological pharmaceuticals, physical and chemical factors on parameters of ejaculate fertility in vitro.Materials and methods. Experiments with a protein-peptide complex (PPC), methylene blue, and hydrogen peroxide were performed on human semen. After semen dilution, the sample was studied under the microscope and sperm motility and other ejaculate parameters were evaluated per the 5th edition WHO standard. Experiments were performed at 20–22 ºС. Statistical data analysis was performed using the Student’s t-test. Differences were considered statistically significant at р <0.05.Results. The results show increased motility in the fraction of active motile sperm in first 30 minutes after incubation with methylene blue. In case of initial asthenospermia, active motility increased by 72 %, in case of normospermia by 89 %. After 2 hours, all motility fractions were at the baseline level.The experiments also showed significant changes in sperm motility in the presence of PPC preparation in the ejaculate: increase in sperm motility was observed beginning at 30-minute mark and this level persisted through 3 hours of observation. A more pronounced change, by 60 %, was observed in the active motile sperm; total motility increased by up to 30 %. After 24 hours, sperm motility remained close to the baseline level, the number of normal sperm forms and live cells did not change. Dependence of the motility change on the preparation concentration should be noted: the highest increase was observed at PPC concentration with total protein level of 10–12 mg/mL. Higher concentrations did not have a positive effect on sperm motility. In experiments with low hydrogen peroxide concentration, a positive effect on sperm motility was observed.Conclusions. Sperm motility is supported by glycolysis energy, and one of the glycolysis enzymes glyceraldehyde 3-phosphate dehydrogenase is tightly bound to the fibrous layer of the flagellum, activation of metabolic pathways leading to increased enzyme activity, increased sperm motility. The mechanism of the observed effect is not entirely clear, however, the obtained data demonstrate potential benefits of further studies on use of pharmaceuticals in andrological and reproductive practice, assisted reproductive technologies, as well as for stimulation of sperm motility in further experimental studies.

Zn2+ is known to be important for the normal brain functions. Disruption of zinc homeostasis and zinc-induced neurotoxicity has been shown to play a role in the development of neurodegenerative diseases. In this work, we investigated the effect of extracellular alkalosis on the zinc ions neurotoxicity in the cultured rat cerebellar granule neurons. Zinc chloride (0.03–0.06 mM, 24 h) added to the culture medium of rat cerebellar granule neurons caused the dose-dependent death of these cells. According to ultrastructural morphological features, the process of cell death could be attributed to necrosis, since it was accompanied by swelling of intracellular organelles and disruption of cell membranes against the background of relatively intact nuclear membranes. Neuronal death was associated with an increase in the level of intracellular free zinc. The toxic effect of zinc ions was significantly decreased when ionotropic glutamate NMDA-receptors were blocked by MK-801 or when the extracellular pH was increased from 7.3 to 7.8, due to a decrease in the zinc overload of the cytoplasm of these cells. The presented results demonstrate that NMDA channels are one of the Zn ion entry pathways in the cultured cerebellar granule neurons. Extracellular alkalosis reduces the zinc overload of the cytoplasm and, consequently, promotes the survival of neurons. Probably, zinc’s neurotoxicity is inextricably linked with changes in the intracellular concentration of protons.