Stroke is a global medical and socio-economic problem and a great demand for alternative therapies, the leading one being stem cell (SC) therapy. Pathogenetic processes in ischemic stroke (II) trigger the mechanisms of necrotic and apoptotic death of neurons with the formation of the central infarct zone («core of ischemia») and the ischemic «penumbra» zone; the severity and reversibility of the injury directly depends on the duration of ischemia. In parallel with pathogenetic processes, endogenous neurogenesis occurs – the proliferation of neurogenic stem and progenitor cells (NSC/NPC) and their migration into the ischemic focus; however, most NSCs and newly formed neurons undergo apoptosis and recovery of lost functions does not occur. Significant efforts are being made to find ways to control neurogenesis, in particular through the transplantation of exogenous SCs. The main factors preventing the use of SCs in humans are moral, ethical, religious and legal aspects related to the source and method of obtaining cells, as well as possible immunocompromised complications due to incompatibility of donor cells with the recipient of the main histocompatibility complex antigens. The safest is the use of autologous SCs (the patient’s own cells), as it does not require the use of immunosuppressive protocols. Due to the relative safety and ease of production, the most common are multipotent mesenchymal stem cells (MSCs), namely MSCs of the bone marrow (BM). Numerous preclinical studies in experimental animals with modeled II, as well as clinical trials conducted over the past 15 years, have shown the safety and feasibility of transplantation of autologous MSCs in patients with severe neurological deficits after II. Two different approaches to the use of MSCs are discussed: neuroprotection in the acute phase and neurorestoration in the chronic phase II. Proposals are currently being developed for phase II/III clinical trials in acute and chronic stroke using BM MSCs, the results of which will form the basis for certified standardized II treatment protocols.

Platelets play an important part in the progression and pathological angiogenesis of brain glioma because of the different granules content and release of microvesicles that are the source of numerous mediators and bioactive substances, which probably provides a "strategy" for the tumour survival. The objective of study was exploring the effect of platelet-released secretion products of patients with brain glioma on the experimental model of tumour growth in vitro. For this purpose, the cells of glioma C6 were cultured for 72 hours under the addition of modified media containing platelet-released secretion products or conditioned media of peripheral blood cells of patients with glioma as well as persons of the comparison group without rough somatic pathology. In control glioma C6 cultures in standard conditions cell clusters were formed by the type of "spheroids", from which radial cell migration occurred, a tense cellular or reticular growth zone was formed, and tumour cells preserved their ability to mitotic division. Under the influence of platelet-released secretion products of patients with glioma, differently directed effects on cell mitotic activity and the number of cell clusters in glioma C6 cultures were detected depending on the degree of tumour malignancy: stimulating effect under the influence of platelet factors of patients with high-malignancy glioma (G4) and inhibitory effect – due to the influence of platelet factors of patients with differentiated glioma (G2). In contrast to the thrombocyte-released factors, the conditioned media of a common pool of peripheral blood cells of patients with G4 glioma suppressed the mitotic activity of tumour cells and did not affect the number of cell clusters. No changes in glioma C6 cultures were revealed after the influence of platelet-released secretion products of persons of the comparison group. The obtained data confirm the important role of platelets in the pathogenesis of brain glioma, pointing to the fundamental difference in the spectrum of biologically active molecules that are released by platelets of patients depending on the degree of tumour malignancy and are able to regulate the cell cycle and proliferative activity of the glioma tumour cells, which may have application as a diagnostic marker as well as predictive marker of response to antitumour therapy.

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A potential strategy for recovery and regeneration of brain damage due to traumatic brain injury is considered to be the transplantation of neurogenic stem and/or progenitor cells (NSCs/NPCs). The key factors of the regenerative non-targeted effects of NSCs/NPCs (so-called bystander effects) include the signal molecules produced by them into the extracellular environment (secretome). The purpose is to study the regenerative bystander effects of rat fetal brain neurogenic cells (FBNCs) in the in vitro model of neurotrauma. Materials and methods. In cell culture of FBNCs from rat fetuses (E14-16), neurotrauma was modeled in vitro by mechanical scratching of monolayer and conditioned medium obtained from 24-h cultures of rat FBNCs was added. Cell phenotype was evaluated by morphological features and by immunocytochemical staining for Nestin and GFAP. The density and length of processes, migration capacity, the cell growth rate and monolayer density in the scratched area were compared. Morphometric study included analysis of the width of the scratched area, the number of migrating cells, the distance of migration and mitotic activity in the intact monolayer. Results. Under the conditions of the nutrient medium of standard composition in the scratched area the signs of endogenous regeneration are shown during 24-48 h of cultivation. The overgrowth of cell processes from monolayer and short distance migration of single undifferentiated or poorly differentiated cells were shown. In the next 72-96 h of observation, the degeneration of migrated cells and processes in the scratched area was detected. Under the influence of conditioned media from 24-h cultures of FBNCs by single addition immediately after scratching at dose of 0.1 mg/ml for protein content the stimulation of regeneration were detected up to 96 hours of cultivation. The migration of cell processes from the monolayer simultaneously with undifferentiated or poorly differentiated cells at 24 hours was shown. The formation of cell clusters and their differentiation (at 48 h), as well as migration of differentiated cells with partial or complete overgrowth of scratched area (72-96 h) were observed. The morphological signs of degeneration of migrated cells in the scratched area appeared only on the 8th day of cultivation. Conditioned media does not affect qualitative and quantitative properties of the culture of rat FBNCs in the intact area where mitotic activity was average. Conclusions. Conditioned medium from 24-h cultures of rat FBNC can stimulate reparation in the in vitro model of neurotrauma in neural cell culture for at least 7 days at a single addition, without affecting the cellular composition and mitotic activity of the intact monolayer.