[Development of blood-brain barrier under the modulation of HIF activity in astroglialand neuronal cells in vitro]. / Osobennosti formirovaniia gematoéntsefalicheskogo bar'era pri moduliatsii aktivnosti HIF v kletkakh astroglial'noi i neironal'noi prirody in vitro.

Barriergenesis is the process of maturation of the primary vascular network of the brain responsible for the establishment of the blood-brain barrier. It represents a combination of factors that, on the one hand, contribute to the process of migration and tubulogenesis of endothelial cells (angiogenesis), on the other hand, contribute to the formation of new connections between endothelial cells and other elements of the neurovascular unit. Astrocytes play a key role in barriergenesis, however, mechanisms of their action are still poorly examined. We have studied the effects of HIF-1 modulators acting on the cells of non-endothelial origin (neurons and astrocytes) on the development of the blood-brain barrier in vitro. Application of FM19G11 regulating expression of HIF-1 activity and GSI-1 suppressing gamma-secretase and/or proteasomal activity resulted in the elevated expression of thrombospondins and matrix metalloproteinases in the developing blood-brain barrier. However, it caused the opposite effect on VEGF expression thus promoting barrier maturation in vitro.

Perinatal Brain Injury is Accompanied by Disturbances in Expression of SLC Protein Superfamily in Endotheliocytes of Hippocampal Microvessels.

The peculiarities in expression of transport proteins and the proteins implicated in the control of glycolysis by the cellular components of neurovascular units were examined in animals of different age under normal conditions and after modeled perinatal stress or hypoxic brain injury. In both cases, the specialties in expression of transport proteins in ontogenesis were revealed. The perinatal hypoxic brain injury resulted in up-regulation of MCT1, MCT4, and GLUT4 expression in endotheliocytes of hippocampal microvessels accompanied by transient elevation of HIF-1α and GSK3 expression.

[MODULATION OF LACTATE PRODUCTION, TRANSPORT AND RECEPTION BY CELLS IN THE MODEL OF BRAIN NEUROVASCUL. UNIT I.]

Metabolic activity of cells within a neurovascular unit is among the factors determining structural and functional integritY of the blood-brain barrier and the an- giogenesis process. in order to verify the hypothesis about the role Of g1YcolYtic activity in the perivascula astroglialcells associated with lactate release in the development of functioning of cerebral microvessel endothelial cells, we have used a three-component model of the brain neurovascular unit in vitro. The cells o f n o n -en d o th elia l o rig in w ere in c u b a te d in th e p rese n ce o f m o d u la to rs o f la c ta te pro d u c n ago ni glu c ose ta a G ly c o s o) , bas t h e oe t a n t a at- blocker of monocarboxylate transporters MCTlprCT and recepltiors of3Ctate0produasan (2-donisyoflactate G e8 breceptor) Iasa estbishe vthat that te suppression of lactate production and transport, prdc o1,adrcpin(C-O-Aa n (2gdoxysgflucoase as a glycolysis inhibitor), transport (phloretin as a sukr of lacaroduto transport , aswellasastimultionof3lactate receptors in astroglial cells, lead to aberrant development of endothelial layer, ther by u g g e tin t h efor atio o f anti ngi gencmi roen ircm ent for cerebral endothelium due to inappropriate lactate-m ediated effects. KeYw.ords:-n-eur-ovascular unit; metabolism; glYcolysis; lactate.

TIGHT JUNCTIONS PROTEINS IN CEREBRAL ENDOTHELIAL CELLS DURING EARLY POSTNATAL DEVELOPMENT.

Formation and functional plasticity of the blood-brain barrier is associated with the molecular events that occur in the brain neurovascular unit in the embryonic and early postnatal development. To study the characteristics of barriergenesis under physiological conditions, as well as recovering from perinatal hypoxia and early life stress, we examined the expression of proteins of cerebral endothelial tight junctions (JAM, ZO1, CLDN5) in rats aged 7, 28 and 70 days of postnatal development (P7­P70). Under physiological conditions, we have found that the number of endothelial cells expressing JAM, ZO1, CLDN5 slightly increases in the cortex, hippocampus and amygdala of the brain in the period from P7 to P70. Perinatal hypoxia significantly increased the number of cells expressing proteins of tight junction proteins (JAM, CLDN5) up to the age P28­P70, whereas the number of cells expressing ZO1 was reduced in the same period of time. Early life stress led to an imbalance between the number of cells expressing ZO1 proteins and that expressing tight junctions proteins, but these changes were in opposite direction to that observed in perinatal hypoxia

Expression of Glutamate and Glutamine Transporter Proteins in Neurovascular Unit Cells In Vitro.

Glutamine transporter protein SLC1A5 and glutamate transporter protein EAAT2 responsible for cell-cell communication and energetic coupling were studied using in vitro model of multicellular neurovascular unit consisting of astrocytes, neurons, and endotheliocytes under standard conditions and during chemical hypoxia in vitro. Hypoxic damage to the neurovascular unit cells increased the number of SLC1A5-expressing cells and reduced the number of EAAT2-expressing astrocytes. Metabolic uncoupling in the neurovascular unit cells under hypoxic conditions resulted from abnormal expression of glutamine and glutamate transporter proteins, which is indicative of impaired glutamine and glutamate transport.

In Vitro Modeling of Brain Progenitor Cell Development under the Effect of Environmental Factors.

We studied in vitro development of brain progenitor cells isolated from healthy 7-9-month-old Wistar rats and rats with experimental Alzheimer's disease kept under standard conditions and in enriched (multistimulus) environment in vivo. Progenitor cells from healthy animals more rapidly formed neurospheres. Considerable changes at the early stages of in vitro development of brain progenitor cells were observed in both groups kept in enriched environment.

[Inflammation and brain aging].

The review covers current concepts on cell and molecular mechanisms of neuroinflammation and aging with the special focus on the regulation of cytokine-producing activity of astroglial cells and intercellular communication. The review reflects that a key component of the aging phenomenon as a result of ineffective implementation of anti-inflammatory response are processes of the dysregulated cytokine production, in particular, an increase in the secretion of proinflammatory cytokines and an imbalance in the expression of the receptors and receptor associated proteins. Interpretation of the molecular mechanisms of cell conjugating neuroinflammation and aging cells can give rise to new therapeutic strategies that are relevant to the treatment of a wide range of central nervous system diseases and the development of new experimental models of diseases of the central nervous system.

[Current concepts of perinatal ischemic injury in the brain neurovascular unit: molecular targets for neuroprotection].

Perinatal hypoxic-ischemic brain injury is a relevant medical and social problem. Among many pathological processes in the neonatal period perinatal hypoxic-ischemic injury is a major cause of further hemorrhage, necrotic and atrophic changes in the brain. This review presents recent data on the basic mechanisms of the hypoxic-ischemic brain injury along the concept of neurovascular unit (neurons, astrocytes, endothelial cells, pericytes) with the focus on alterations in cell-to-cell communication. Pathological changes caused by ischemia-hypoxia are considered within two phases of injury (ischemic phase and reperfusion phase). The review highlights changes in each individual component of the neurovascular unit and their interactions. Molecular targets for pharmacological improvement of intercellular communication within neurovascular unit as a therapeutic strategy in perinatal brain injury are discussed.

[NAD+-converting enzymes in neuronal and glial cells: CD38 as a novel target for neuroprotection].

The review contains current data on molecular mechanisms which control NAD+ homeostasis in brain cells. It also deals with the role of NAD+-converting enzymes in regulation of functional activity, viability and intercellular communication of neuronal and glial cells. Special attention is paid to involvement of CD38 into regulation of NAD+ levels in brain cells in normal and pathological conditions.

Nootropic activity of extracts from wild and cultivated Alfredia cernua.

Antihypoxic and nootropic activities of extracts from aerial parts of wild and cultivated Alfredia cernua (L.) Cass. were studied on the models of pressure chamber hypoxia, open field test, and passive avoidance conditioning. The extracts of Alfredia cernua promoted retention of the orientation reflex and passive avoidance conditioned response and normalized orientation and exploratory activities disordered as a result of hypoxic injury. The efficiency of the extracts was superior to that of piracetam by the effect on retention of passive avoidance response throughout the greater part of the experiment. Nootropic activity of cultivated Alfredia cernua was not inferior to that of the wild plant.

[Effect of Alfredia cernua extracts on the behavior, memory, and physical work capacity of experimental animals].

It is established, that Alfredia cernua extracts possess nootropic properties. The extracts favor improvement of the indices of orientation and exploration behavior, retention of the passive avoidance reflex upon hypoxic shock, and increase in physical work capacity in mice. The most pronounced effect was observed upon the administration of a 95% ethanol extract of Alfredia cernua.