The aim of this work was to study the effect of intravenous transplantation of human mesenchymal stem cells (hMSCs) on the functional state of KATP channels of smooth-muscle cells of cerebral arteries at different times of the postischemic period. Using a device for intravital visualization of pial vessels, the reaction of arteries to the KATP-channel blocker glibenclamide (GC), the activator of the same channels of pinacidil (PI), acetylcholine (ACh), and ACh against a background of GC action (ACh/GC) 7, 14, and 21 days after cerebral ischemia/reperfusion (I/R) and intravenous hMSC transplantation. On exposure to GC 7 days after I/R, two to five times fewer arteries narrowed than in the SO group and 1.5 times fewer expanded after PI. The introduction of hMSCs on the day of I/R of the brain after 7 days had no effect on the functioning of KATP channels: the constrictor reaction to GC and the dilator reaction to PI in this group were the same as in animals that underwent I/R. Fourteen days after I/R, the number of narrowed pial arteries on GС was 1.5–2 times less than in SO rats; the number of arteries that responded with dilatation to PI was 2–2.5 times less. In the cell-therapy group, for 14 days after I/R, the number of pial arteries that narrowed under the influence of GС and expanded under that of PI almost completely corresponded to those in SO rats. On day 21 after I/R, complete recovery of pial-artery responses to GC to the level in LO rats was observed. In the cell-therapy group, the reactivity of the pial arteries fully corresponded to the indicators in the SO group of animals. The functional state of KATP channels after I/R of the brain was assessed by comparing the dilator reactions of the pial arteries when exposed to pure ACh and ACh against a background of KATP channels being blocked with glibenclamide (ACh/GC). In SO animals, GC blocked the dilator reaction to ACh. The application of ACh against the background of GC increased the number of dilatations 7–14 days after I/R. After 21 days, the number of dilated vessels on exposure to ACh and ACh/GC was the same. In animals with transplanted hMSCs, excluding the first 7 days, GC blocked the dilator reaction of the pial arteries to ACh in the same way as in the SO group. It can be concluded that I/R of the rat cerebral cortex reduces the contribution of KATP channels to maintaining the basal tone of the pial arterial vessels. Changes persist for 14 days after ischemic exposure. At the same time, in the period from 7 to 21 days after I/R, the role of KATP channels in the dilatation of pial arteries on ACh decreased and by day 21 channels practically did not participate in the dilator response. Intravenous transplantation of hMSCs on the day of brain I/R results in earlier (as early as after 14 days) restoration of participation of SMC KATP channels in maintaining the basal tone and ACh-mediated dilatation of pial arteries.

This study aims at examining how intravenous transplantation of human mesenchymal stem cells (MSCs) performed on the day of ischemia/reperfusion affects the vascular density and the reactivity of the pial arteries and tissue perfusion in the cerebral cortex 7, 14, and 21 days after ischemic exposure. The density of the entire microvascular network and arterial vessels in the pial membrane of the sensorimotor cortex of rats undergoing cerebral ischemia/reperfusion (I/P) and MSC intravenous transplantation were assessed with equipment for microcirculation monitoring. The same setup was used to study the reactivity of the pial arteries exposed to acetylcholine (ACh). In parallel, the perfusion index (PI) was measured in the sensorimotor cortex using a LAKK-M laser Doppler system. The density of the entire microvascular network and arterial vessels decreased more than in the case of sham-operated (SO) rats in the first 7 days after I/R: by 1.6 and 1.4 times on average, respectively. After 14 days, these indicators were 1.4 and 1.2 times; after 21 days, 1.2 and 1.3 times. In animals that underwent I/R, the reactivity of the pial arteries to ACh significantly declined. Seven days after I/R, the number of dilating arteries decreased by 1.4–1.7 times; after 14 days, by 1.6–1.9 times; and, after 21 days, by 1.2–1.7 times. After 21 days, the PI level decreased statistically significantly (on average, by 1.6 times). Intravenous administration of MSCs preserved the density of the microvascular network of the pial membrane in rats at the level of control animals at all periods after I/R. The PI 21 days after I/R was 1.2 times lower than in the SO group, but statistically higher than in rats with ischemic brain injury without MSC administration. It is concluded that intravenous transplantation of MSCs made it possible to prevent degradation of the microvascular bed in the cerebral cortex of rats after I/R and to preserve the reactivity of the pial arteries at the level of control animals. The reactivity in the cell therapy group also did not differ from the control values. The PI 21 days after I/R was 1.2 times lower than in the SO group, but statistically higher than in rats with ischemic brain injury without MSC administration. It is concluded that intravenous transplantation of MSCs made it possible to prevent degradation of the microvascular system in the cerebral cortex of rats after I/R and to preserve the reactivity of the pial arteries at the level of control animals.

The aim of this work is to study the deterioration of the contractile function of smooth muscle cells in pial arteries after subtotal nephrectomy, as well as the possibility of restoring this function by transplantation of human mesenchymal stem cells. A self-designed visualizing device for studying microcirculation (160× magnification) was used to study the reactivity of sensorimotor cortex pial vessels to hydrogen sulfide (H2S), L-NAME nonselective nitric oxide synthase inhibitor, and the combined application of H2S and L-NAME in sham-operated rats, nephrectomized rats, and nephrectomized animals that received human mesenchymal stem cells (hMSCs) intravenously. In parallel, the myogenic tone of cerebral vessels was assessed with a LAKK-M laser doppler. The results showed that, 4 months after nephrectomy in rats, the reactivity of pial arteries to H2S and L-NAME seriously deteriorated (the number of dilated arteries decreased by 1.2–1.7 times, and the extent of constriction was 6–17% smaller). The myogenic tone of cerebral vessels after nephrectomy was 1.5 times higher than in control rats. Intravenous hMSC transplantation allowed the myogenic tone and the reactivity of smooth muscle cells (SMCs) to be maintained at the level of control animals.

— The aim of the investigation was to examine the effect of intravenous transplantation of human stem cells (hMSCs) on the main parameters of microcirculation (density of the microvascular network, reactivity of arterial vessels, tissue perfusion (TP) and oxygen saturation (SaO2)) in the cerebral cortex of rats after nephrectomy. Using an apparatus for studying microcirculation (magnification 40×), the density of the entire microvascular network and the density of arterial vessels in the pial membrane of the sensorimotor cortex of the brain of nephrectomized rats after intravenous transplantation of hMSCs were studied with equipment for the study of microcirculation. Equipment with greater magnification (160×) was utilized to investigate the reactivity of the pial arteries after exposure to acetylcholine (ACh). In parallel, the TP and SaO2 parameters in the sensorimotor cortex were measured with a LAKK-M laser doppler. The results showed that, 4 months after nephrectomy in rats (removal of five-sixths of the whole renal tissue), the density of the entire microvascular network and the density of arterial vessels decreased by an average of 1.3 and 1.5 times, respectively. The reactivity of the pial arteries after ACh exposure significantly reduced: the number of dilated arteries decreased by 2.1–4.4 times. TP (by 20%) and SaO 2 (from 94.8 ± 0.7 to 91.2 ± 1.8%) significantly decreased. Intravenous administration of MSCs restored the density of the pial membrane microvascular network (at the level of control animals) in rats after nephrectomy. All other parameters of microcirculation (reactivity, TP, and SO2) in the cell therapy group also did not differ from the control values. It was concluded that the use of hMSCs prevented degradation of the microvascular bed in the cerebral cortex of rats after nephrectomy and preserved the main parameters of microcirculation at the level of control animals.

Among the properties of lactoferrin (LF) are bactericidal, antianemic, immunomodulatory, antitumour, antiphlogistic effects. Previously we demonstrated its capacity to stabilize in vivo HIF-1-alpha and HIF-2-alpha, which are redox-sensitive multiaimed transcription factors. Various tissues of animals receiving recombinant human LF (rhLF) responded by expressing the HIF-1-alpha target genes, hence such proteins as erythropoietin (EPO), ceruloplasmin, etc. were synthesized in noticeable amounts. Among organs in which EPO synthesis occurred were brain, heart, spleen, liver, kidneys and lungs. Other researchers showed that EPO can act as a protectant against severe brain injury and status epilepticus in rats. Therefore, we tried rhLF as a protector against the severe neurologic disorders developed in rats, such as the rotenone-induced model of Parkinson’s disease and experimental autoimmune encephalomyelitis as a model of multiple sclerosis, and observed its capacity to mitigate the grave symptoms. Moreover, an intraperitoneal injection of rhLF into mice 1 h after occlusion of the medial cerebral artery significantly diminished the necrosis area measured on the third day in the ischaemic brain. During this period EPO was synthesized in various murine tissues. It was known that EPO induces nuclear translocation of Nrf2, which, like HIF-1-alpha, is a transcription factor. In view that under conditions of hypoxia both factors demonstrate a synergistic protective effect, we suggested that LF activates the Keap1/Nrf2 signaling pathway, an important link in proliferation and differentiation of normal and malignant cells. J774 macrophages were cultured for 3 days without or in the presence of ferric and ferrous ions (RPMI-1640 and DMEM/F12, respectively). Then cells were incubated with rhLF or Deferiprone. Confocal microscopy revealed nuclear translocation of Nrf2 (the key event in Keap1/Nrf2 signaling) induced by apo-rhLF (iron-free, RPMI-1640). The reference compound Deferiprone (iron chelator) had the similar effect. Upon iron binding (in DMEM/F12) rhLF did not activate the Keap1/Nrf2 pathway. Added to J774, apo-rhLF enhanced transcription of Nrf2-dependent genes coding for glutathione S-transferase P and heme oxygenase-1. Western blotting revealed presence of Nrf2 in mice brain after 6 days of oral administration of apo-rhLF, but not Fe-rhLF or equivalent amount of PBS. Hence, apo-LF, but not holo-LF, induces the translocation of Nrf2 from cytoplasm to the nucleus, probably due to its capacity to induce EPO synthesis.

We performed morphological analysis of the structure of rat hippocampus after ablation of the left sensorimotor cortex. Four experimental groups were formed: two control groups (intravenous and intracerebral injections of the culture medium) and two experimental groups (intravenous and intracerebral transplantation of MSC). Ten weeks after surgery, disturbed cytoarchitectonics and great number of dead neurons were found in all zones of the hippocampus in animals of the control groups. In animals receiving cell therapy, no pathological changes in the structure of the hippocampus were found: hyperchromatic neurons were absent and the cells had regular shape and closely adjoined to each other.

We studied the effect of various methods of transplantation of mesenchymal stem cells on neuronal survival in rat brain 1 and 6 weeks after severe traumatic brain injury. It was found that intracerebral and systemic transplantation of mesenchymal stem cells improves neuronal survival in the piriform cortex of the contralateral hemisphere without affecting neuronal survival in the marginal zone of the traumatic cavity and amygdaloid nuclei. Intracerebral transplantation of mesenchymal stem cells increases the content of the astroglial component of the scar in the borderline zone of the traumatic cavity.

The effects of the allogeneous demineralized bone transplants, seeded with bone marrow-derived multipotent mesenchymal stromal cells CMSCsJ, on the healing of the damaged articular cartilage and the subchondral bone were studied. It was shown that the use of allogeneous as well as autologous MSCs on the demineralized bone transplants and also on the transplants combined with type I collagen gel promote the remodeling of the regenerating tissue and the recovery of the histotypic cartilaginous and osseous structures in comparison with the articular surface regeneration without any therapy or after the procedure of the mosaic chondroplasty. Nevertheless, the positive effects of cell therapy were not clinically prominent, which means most probably in that case that the generally accepted experimental model is not adequate in full measure, but the approach used is promising.

Cell therapy is prospective, modern attempt to ischemic stroke treatment. It has been being widely worked out recently. We suggest mesenchymal stem cells (MSC) as a cell therapy agent in the therapy of this disease. Experiments were carried out in inbred male Wistar-Kyoto rats. Animals were subjected to middle cerebral artery occlusion (MCAO). MSCs were isolated from rat bone marrow, expanded in culture and labelled with vital fluorescent dye PKH-26. Then 5 x 10(6) cells were injected into the tail vein on the day of MCAO and three days later. Control group animals received PBS injection (negative control). Cognitive function restoration was estimated by Morris Water Maze testing during 6 weeks after MCAO. Animals were sacrificed 1, 2, 3, 5 days and 1, 2, 4 and 6 weeks after operation. Intravenous MSC transplantation decreased post-operation mortality and benefited behavioural and neurological recovery. Experimental groups animals revealed changes in aseptic inflammation processes which were completed faster comparing to control group. That effect correlated with accelerated glial scar formation. Reduction of the infarct volumes and such post-stroke after-effects as border zone gliosis and liquor cysts formation accompanied by increased angiogenesis and subventricular zone cells proliferation were shown after cell therapy. The obtained results referred to both cell therapy groups. Thus, MSC injection benefited post-stroke rehabilitation irrespective of transplantation time. However, further investigation should be carried out in order to find out the mechanism of their action.