Traumatic brain injuries account for 30–50% of all physical traumas and are the most common pathological diseases of the brain. Mechanical damage of brain tissue leads to the disruption of the blood–brain barrier and the massive death of neuronal, glial, and endothelial cells. These events trigger a neuroinflammatory response and neurodegenerative processes locally and in distant parts of the brain and promote cognitive impairment. Effective instruments to restore neural tissue in traumatic brain injury are lacking. Glial cells are the main auxiliary cells of the nervous system, supporting homeostasis and ensuring the protection of neurons through contact and paracrine mechanisms. The glial cells’ secretome may be considered as a means to support the regeneration of nervous tissue. Consequently, this study focused on the therapeutic efficiency of composite proteins with a molecular weight of 5–100 kDa secreted by glial progenitor cells in a rat model of traumatic brain injury. The characterization of proteins below 100 kDa secreted by glial progenitor cells was evaluated by proteomic analysis. Therapeutic effects were assessed by neurological outcomes, measurement of the damage volume by MRI, and an evaluation of the neurodegenerative, apoptotic, and inflammation markers in different areas of the brain. Intranasal infusions of the composite protein product facilitated the functional recovery of the experimental animals by decreasing the inflammation and apoptotic processes, preventing neurodegenerative processes by reducing the amounts of phosphorylated Tau isoforms Ser396 and Thr205. Consistently, our findings support the further consideration of glial secretomes for clinical use in TBI, notably in such aspects as dose-dependent effects and standardization.

Neurodegenerative diseases pose a significant challenge to modern medicine. Despite significant advances in neurology, current therapeutic approaches often prove insufficient to treat such disorders. This study investigates the neuroprotective effect of extracellular vesicles derived from glial derivates of human-induced pluripotent stem cells. The extracellular vesicle’s cargo was characterised by proteomic analysis. The neuroprotective effect was assessed using a model of glutamate excitotoxicity performed on a primary culture of cortical neuroglial cells. The viability of cells was estimated using the MTT test and morphometric analyses. A comprehensive methodology was applied to investigate intracellular mechanisms, integrating assessments of intracellular calcium concentrations, mitochondrial membrane potential, and targeted inhibition of the PI3K-Akt pathway. Transcriptomic analysis of neuroglial cultures was used to validate the role of obtained mechanisms of extracellular vesicle’s neuroprotective effect. The obtaining results demonstrated the improvement of neuronal survival by reducing intracellular calcium levels and stabilising mitochondrial membrane potential under glutamate-induced excitotoxicity via PI3K-Akt signalling pathway activation. Moreover, the vesicles contained proteins that contribute to preventing apoptotic processes, activating regeneration of the nervous system, and modulating calcium ion transport and are associated with redox processes. Further transcriptomic analyses of neuroglial cultures treated with EVs showed an up-regulation of genes associated with regeneration, inhibition of calcium ion transport, regulation of membrane depolarisation, and negative regulation of apoptotic pathways.

Neurodegenerative diseases pose a significant challenge to modern medicine. Despite significant advances in neurology, current therapeutic approaches often prove insufficient to treat such disorders. This study investigates the neuroprotective effect of extracellular vesicles derived from glial derivates of human induced pluripotent stem cells. The extra-cellular vesicle’s cargo was characterised by proteomic analysis. They neuroprotective ef-fect was assessed using a model of glutamate excitotoxicity performed on primary culture of cortical neurons. The viability of cortical neurons was estimated using the MTT test and morphometric analyses. A comprehensive methodology was applied to investigate intra-cellular mechanisms, integrating assessments of intracellular calcium concentrations, mitochondrial membrane potential, and targeted inhibition of the PI3K‑Akt pathway. Transcriptomic analysis of cortical neurons was used to validated the role of obtained mechanisms of extracellular vesicle’s neuroprotective effect. The obtaining results demon-strated the improvement of neuronal survival by reducing intracellular calcium levels, and stabilizing mitochondrial membrane potential under glutamate-induced excitotoxi-city via PI3K-Akt signaling pathway activation. Moreover, the vesicles contained proteins that contribute to preventing apoptotic processes, activating regeneration of nervous sys-tem, modulating of calcium ion transport and associated with redox processes. Further transcriptomic analyses of neuroglial cultures treated with EVs showed up-regulation of genes associated with regeneration, inhibition of calcium ion transport, regulation of membrane depolirisation and negative regulation of apoptotic pathways.

Relevance. Modern research in the field of biomedicine leads to the development of therapeutic drugs based on extracellular vesicles, which are defined as sources of production, as well as targeted modification. In the presented work, for the first time, transcriptome profiling of primary culture of cortical neurons under the influence of extracellular vesicles obtained from glial cells during glutamate excitotoxicity was carried out in order to determine differentially expressed genes. Materials and Methods. Extracellular vesicles were obtained from the conditioned medium of human glial progenitor cells using ultracentrifugation. Model of glutamate excitotoxicity, distributed on the first cultured cortical neurons of cells (P0) with the addition of 100 μM glutamate. Sequencing of prepared libraries of electronic technologies on the NextSeq 1000 platform (Illumina, USA) using the NextSeq 1000/2000 P2 (200 cycles) v3 reagent kit supplemented with 2 % Phix (Illumina) as an internal control. The criterion for statistical innovation of gene expression change between officially recognized FDR 0.05. Results and Discussion. Transcriptome analysis showed that the addition of extracellular vesicles during glutamate excitotoxicity leads to increased expression of 190 genes and decreased expression of 309 genes (p value 0.05 and |FC| 1.5). Gene analysis using the Gene Onthology database showed that genes with increased expression are consistently classified by biological processes. The most represented were: regeneration, reorganization of the extracellular matrix and cytoskeleton, maintenance of homeostasis, activation of the PI3K-Akt pathway and response to cellular stress. Genes with reduced expression were consistently classified into groups: calcium transport, regulation of neuronal processes, apoptosis, glutathergic synapse. These data can indicate that. Extracellular vesicles trigger survival processes in nerve cells when exposed to glutamate and inhibit pathways associated with the entry of substances and glutamate into the cell. Conclusions. Extracellular vesicles enhance the expression of genes with survival and inhibit genes, resulting in calcium transport and apoptosis. The results of the study show the promise of using extracellular vesicles of glial origin as a basis for developing new therapeutic approaches to individual neurological diseases.

Introduction: Traumatic brain injury presents a significant challenge, characterized by complex pathologies including neuroinflammation and axonal degeneration with limited treatment options. One of the promising areas of traumatic brain injury treatment is cell therapy. However, a critical aspect of this therapy is the method of stem/progenitor cell administration. This study aimed to evaluate the therapeutic potential of glial progenitor cells derived from induced pluripotent stem cells after intra-arterial administration in an experimental model of traumatic brain injury of male Wistar rats. Methods: Neurological status was assessed using the limb—placing, cylinder, and beam walking tests. Lesion volume was quantified by magnetic resonance imaging. Markers of inflammation and neurogenesis were analyzed using immunofluorescence staining and quantitative reverse transcription polymerase chain reaction. Cell migration was tracked via magnetic resonance imaging and histology. Results: Intra-arterial administration provided targeted delivery of cells into the cerebral vasculature. The cells successfully crossed the blood-brain barrier, migrated into the brain parenchyma, and were detectable for up to 48 hours. Transplantation led to significant improvement in sensorimotor function, reduced neuroinflammation in the injured area, and promoted neurogenesis. Discussion: The observed therapeutic effects are likely mediated by the factors secreted by glial progenitor cells, which possess anti-inflammatory and regenerative properties (paracrine signaling effect) and/or by their transient interactions with the target cells (juxtacrine signaling effect). Conclusion: Glial progenitor cells derived from induced pluripotent stem cells and delivered via the intra-arterial route show promise for the treatment of traumatic brain injury by reducing inflammation and enhancing neurogenesis.