Репозиторий Университета

© 2019 Stem cells and the niche in which they reside feature a complex microenvironment with tightly regulated homeostasis, cell-cell interactions and dynamic regulation of metabolism. A significant number of organoid models has been described over the last decade, yet few methodologies can enable single cell level resolution analysis of the stem cell niche metabolic demands, in real-time and without perturbing integrity. Here, we studied the redox metabolism of Lgr5-GFP intestinal organoids by two emerging microscopy approaches based on luminescence lifetime measurement – fluorescence-based FLIM for NAD(P)H, and phosphorescence-based PLIM for real-time oxygenation. We found that exposure of stem (Lgr5-GFP) and differentiated (no GFP) cells to high and low glucose concentrations resulted in measurable shifts in oxygenation and redox status. NAD(P)H-FLIM and O2-PLIM both indicated that at high ‘basal’ glucose conditions, Lgr5-GFP cells had lower activity of oxidative phosphorylation when compared with cells lacking Lgr5. However, when exposed to low (0.5 mM) glucose, stem cells utilized oxidative metabolism more dynamically than non-stem cells. The high heterogeneity of complex 3D architecture and energy production pathways of Lgr5-GFP organoids were also confirmed by the extracellular flux (XF) analysis. Our data reveals that combined analysis of NAD(P)H-FLIM and organoid oxygenation by PLIM represents promising approach for studying stem cell niche metabolism in a live readout.

© 2018, Springer Science+Business Media, LLC, part of Springer Nature. We studied the expression of Hif-1α, Nf-κb, and Vegf genes in the liver and serum levels of HIF-1α, erythropoietin, VEGF, TGF-β, 8-isoprostane, and corticosterone in Wistar rats with different resistance to hypoxia in 5 and 90 min after acute exposure to hypobaric hypoxia. In 5 min after hypoxic exposure, Hif-1α expression in the liver and serum levels of erythropoietin, VEGF, and TGF-β in high-resistant rats were higher than in low-resistant animals. In highresistant rats, the increment in expression of Nf-κb gene responsible for the control over the inflammatory processes was more pronounced than in low-resistant animals. In 90 min after hypoxic exposure, the serum levels of HIF-1α, erythropoietin, VEGF, and TGF-β returned to normal in high-resistant rats, while in low-resistant animals, an increase in 8-isoprostane and TGF-β concentrations was observed. The rats with different resistance to hypoxia were characterized by different changes in biomolecular parameters determining predilection to inflammatory diseases.

© 2018 by the authors. Neonatal hypoxia–ischemia is one of the main causes of mortality and disability of newborns. To study the mechanisms of neonatal brain cell damage, we used a model of neonatal hypoxia–ischemia in seven-day-old rats, by annealing of the common carotid artery with subsequent hypoxia of 8% oxygen. We demonstrate that neonatal hypoxia–ischemia causes mitochondrial dysfunction associated with high production of reactive oxygen species, which leads to oxidative stress. Targeted delivery of antioxidants to the mitochondria can be an effective therapeutic approach to treat the deleterious effects of brain hypoxia–ischemia. We explored the neuroprotective properties of the mitochondria-targeted antioxidant SkQR1, which is the conjugate of a plant plastoquinone and a penetrating cation, rhodamine 19. Being introduced before or immediately after hypoxia–ischemia, SkQR1 affords neuroprotection as judged by the diminished brain damage and recovery of long-term neurological functions. Using vital sections of the brain, SkQR1 has been shown to reduce the development of oxidative stress. Thus, the mitochondrial-targeted antioxidant derived from plant plastoquinone can effectively protect the brain of newborns both in pre-ischemic and post-stroke conditions, making it a promising candidate for further clinical studies.

© 2018, Springer International Publishing AG, part of Springer Nature.  Molecular oxygen (O 2 ) is a key player in cell mitochondrial function, redox balance and oxidative stress, normal tissue function and many common disease states. Various chemical, physical and biological methods have been proposed for measurement, real-time monitoring and imaging of O 2 concentration, state of decreased O 2 (hypoxia) and related parameters in cells and tissue. Here, we review the established and emerging optical microscopy techniques allowing to visualize O 2 levels in cells and tissue samples, mostly under in vitro and ex vivo, but also under in vivo settings. Particular examples include fluorescent hypoxia stains, fluorescent protein reporter systems, phosphorescent probes and nanosensors of different types. These techniques allow high-resolution mapping of O 2 gradients in live or post-mortem tissue, in 2D or 3D, qualitatively or quantitatively. They enable control and monitoring of oxygenation conditions and their correlation with other biomarkers of cell and tissue function. Comparison of these techniques and corresponding imaging setups, their analytical capabilities and typical applications are given.

© Copyright 2018, Mary Ann Liebert, Inc., publishers 2018. Aim: To compare a program based on intermittent hypoxia-hyperoxia training (IHHT) consisting of breathing hypoxic-hyperoxic gas mixtures while resting to a standard exercise-based rehabilitation program with respect to cardiorespiratory fitness (CRF) in older, comorbid cardiac outpatients. Materials and Methods: Thirty-two cardiac patients with comorbidities were randomly allocated to IHHT and control (CTRL) groups. IHHT completed a 5-week program of exposure to hypoxia-hyperoxia while resting, CTRL completed an 8-week tailored exercise program, and participants in the CTRL were also exposed to sham hypoxia exposure. CRF and relevant hematological biomarkers were measured at baseline and after treatment in both groups. Results: After intervention, CRF in the IHHT group was not significantly different (n = 15, 19.9 ± 6.1 mlO2 minutes-1 kg-1) compared with the CTRL group (n = 14, 20.6 ± 4.9 mlO2 minutes-1 kg-1). CRF in IHHT increased significantly from baseline (6.05 ± 1.6 mlO2 minutes-1 kg-1), while no difference was found in CTRL. Systolic and diastolic blood pressures were not significantly different between groups after treatment. Hemoglobin content was not significantly different between groups. Erythrocytes and reticulocytes did not change pre/post interventions in both experimental groups. Conclusions: IHHT is safe in patients with cardiac conditions and common comorbidities and it might be a suitable option for older patients who cannot exercise. A 5-week IHHT is as effective as an 8-week exercise program in improving CRF, without hematological changes. Further studies are needed to clarify the nonhematological adaptations to short, repeated exposure to normobaric hypoxia-hyperoxia.

© 2018, Indian Journal of Public Health Research and Development. All rights reserved. Study design: randomized controlled before-and-after and in follow-up trial. Forty-six CAD patients volunteered to take part in the study: a group of 27 patients undertook an Intermittent Hypoxia (O2 at 10%) - Hyperoxia (O2 at 30%) Training (IHHT), while a control group (CTRL) of 19 patients was allocated to sham IHHT treatment (breathing via face mask by room air, O2 at 21%). Exercise performance, blood and metabolic profile, quality of life (MOS SF-36, Seattle Angina Questionnaire, SAQ) were measured before and after IHHT/sham IHHT in both groups; the intervention group was also assessed one month after completing the IHHT. The IHHT intervention group showed improved exercise capacity (+1,8 ml O2/min/kg, p=0,02), reduced resting systolic and diastolic blood pressures (151/85 before vs 130/73 after p<0,01), enhanced Left Ventricle Ejection Fraction (62,6±5,5% vs 58±6,2%, p<0,01), glycemia was significantly reduced only at 1-month follow-up (6,18±1,7 after vs 7,10±2,34 mmol/l at baseline, p=0,037). Frequency of angina as reason to stop exercising was significantly reduced after treatment and at 1-month follow-up. In CAD patients an Intermittent Hypoxia-Hyperoxia Training program is associated with improved exercise tolerance, risks factors profile and quality of life (SF-36, SAQ). IHHT has proved to be safe, well tolerable and easily applicable in cardiac patients.

© 2018, Pediatria Ltd.. All rights reserved.  Objective of the research – to reveal the correlation between neurochemical criteria in the neonatal period and the consequences of severe hypoxic hemorrhagic CNS lesions in children according to catamnesis data. Materials and methods: researchers analyzed 54 cases of newborns of different gestational age (GA) that were in the ICU after birth due to severe condition; all newborns had combined hypoxic hemorrhagic brain lesion detected by neurosonography – periventricular leukomalacia (PVL) and intraventricular hemorrhage (IVH) of various severity. Catamnesis follow-up was performed up to 2–2,5 years of age. The control group consisted of 20 newborns, comparable in GA, body weight at birth, with an Apgar score of at least 6 points in the 1st minute of life and without changes in neurosonography. In the neonatal period, serum concentrations of S100, BDNF, VEGF, ALCAM, DR5 were studied in dynamics using the quantitative ELISA (Enzyme Linked Immuno Sorbent Assay) according to a standard protocol. Results: the concentration of factors contributing to destructive changes in tissues (S100, DR5, ALCAM) in the serum, was in inverse correlation with the level of VEGF and BDNF. The latter had a direct correlation relationship. VEGF directly correlated with CNTF by the end of the 2 nd week of life. Results of catamnesis follow-up: 43 children diagnosed with cerebral palsy, 25 with spastic diplegia, 18 with spastic tetraparesis, and 11 without evident motor disorders. In 28 children I–III level of motor disorders was determined according to GMFS, in 26 children – IV–V level. At the age of 2 years, all children underwent MRI of the brain and gliio-atrophic changes were detected. Significant differences in the implementation of neurological consequences were found between the number of children with grade I and II IVH and PVL and III–IV degree IVH and PVL. Conclusion: children with PVL and IVH III–IV degree have a high risk of severe neurological outcomes – spastic tetraparesis, impaired motor activity by GMFS IV–V level, mental retardation and symptomatic epilepsy.

© 2018 Media Sphera Publishing Group. All rights reserved. Prolyl-4-hydroxylases of hypoxia-inducible factor (HIF-P4Hs) are enzymes that, under the conditions of normoxia, cause degradation of the HIF-transcriptional protein, which regulates a number of metabolic processes, including erythropoiesis, glucose level and lipid metabolism. In hypoxic conditions, on the contrary, their activity is suppressed and HIF stabilization takes place. This mechanism, i.e. stabilization of HIF by inhibition of HIF-P4Hs was the basis for the development of drugs designed for treatment of renal anemia, which are currently in stages 2 and 3 of clinical trials and are showing encouraging results. Recently, it has also been reported that inhibition of HIF-P4Hs can be effective in treatment of cardiometabolic diseases - coronary heart disease, hypertension, obesity, metabolic syndrome, diabetic cardiomyopathy and atherosclerosis. The review, based on the most recent data, discusses in detail molecular mechanisms of therapeutic effect of HIF-P4Hs inhibition in these pathological conditions and provides evidence that these mechanisms are associated with HIF stabilization and gene expression, improving perfusion and endothelial function, reprogramming metabolism from oxidative phosphorylation to anaerobic glycolysis, reducing inflammation and having beneficial effect on the innate immune system.

The discovery and development of effective antihypoxic drugs is an important issue in modern experimental and clinical pharmacology. Complexes of zinc containing imidazole cycles as ligands are promising candidates for the design of novel drugs, including pharmacotherapeutic tools for patient’s protection under conditions of oxygen deficiency. Herein, we report antihypoxic activity of zinc complexes with N-alkenylimidazoles, and, specifically, a novel drug Acyzol, which can be used as efficient antidote after poisoning by carbon monoxide and other combustion products.

The discovery and development of effective antihypoxic drugs is an important issue in modern experimental and clinical pharmacology. Complexes of zinc containing imidazole cycles as ligands are promising candidates for the design of novel drugs, including pharmacotherapeutic tools for patient’s protection under conditions of oxygen deficiency. Herein, we report antihypoxic activity of zinc complexes with N-alkenylimidazoles, and, specifically, a novel drug Acyzol, which can be used as efficient antidote after poisoning by carbon monoxide and other combustion products.