A Role for VEGFR2 Activation in Endothelial Responses Caused by Barrier Disruptive OxPAPC Concentrations

Introduction: Oxidation products of 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphatidylcholine (OxPAPC) differentially modulate endothelial cell (EC) barrier function in a dose-dependent fashion. Vascular endothelial growth factor receptor-2 (VEGFR2) is involved in the OxPAPC-induced EC inflammatory activation. This study examined a role of VEGFR2 in barrier dysfunction caused by high concentrations of OxPAPC and evaluated downstream signaling mechanisms resulting from the effect of OxPAPC in EC from pulmonary and systemic circulation

Prostacyclin post-treatment improves LPS-induced acute lung injury and endothelial barrier recovery via Rap1

Protective effects of prostacyclin (PC) or its stable analog beraprost against agonist-induced lung vascular inflammation have been associated with elevation of intracellular cAMP and Rac GTPase signaling which inhibited the RhoA GTPase-dependent pathway of endothelial barrier dysfunction. This study investigated a distinct mechanism of PC-stimulated lung vascular endothelial (EC) barrier recovery and resolution of LPS-induced inflammation mediated by small GTPase Rap1. Efficient barrier recovery was observed in LPS-challenged pulmonary EC after prostacyclin administration even after 15 h of initial inflammatory insult and was accompanied by the significant attenuation of p38 MAP kinase and NFκB signaling and decreased production of IL-8 and soluble ICAM1. These effects were reproduced in cells post-treated with 8CPT, a small molecule activator of Rap1-specific nucleotide exchange factor Epac. By contrast, pharmacologic Epac inhibitor, Rap1 knockdown, or knockdown of cell junction-associated Rap1 effector afadin attenuated EC recovery caused by PC or 8CPT post-treatment. The key role of Rap1 in lung barrier restoration was further confirmed in the murine model of LPS-induced acute lung injury. Lung injury was monitored by measurements of bronchoalveolar lavage protein content, cell count, and Evans blue extravasation and live imaging of vascular leak over 6 days using a fluorescent tracer. The data showed significant acceleration of lung recovery by PC and 8CPT post-treatment, which was abrogated in Rap1a(-/-) mice. These results suggest that post-treatment with PC triggers the Epac/Rap1/afadin-dependent mechanism of endothelial barrier restoration and downregulation of p38MAPK and NFκB inflammatory cascades, altogether leading to accelerated lung recovery

Reciprocal regulation of PKA and rac signaling

Activated G protein-coupled receptors (GPCRs) and receptor tyrosine kinases relay extracellular signals through spatial and temporal controlled kinase and GTPase entities. These enzymes are coordinated by multifunctional scaffolding proteins for precise intracellular signal processing. The cAMP-dependent protein kinase A (PKA) is the prime example for compartmentalized signal transmission downstream of distinct GPCRs. A-kinase anchoring proteins tether PKA to specific intracellular sites to ensure precision and directionality of PKA phosphorylation events. Here, we show that the Rho-GTPase Rac contains A-kinase anchoring protein properties and forms a dynamic cellular protein complex with PKA. The formation of this transient core complex depends on binary interactions with PKA subunits, cAMP levels and cellular GTP-loading accounting for bidirectional consequences on PKA and Rac downstream signaling. We show that GTP-Rac stabilizes the inactive PKA holoenzyme. However, β-adrenergic receptor-mediated activation of GTP-Rac–bound PKA routes signals to the Raf-Mek-Erk cascade, which is critically implicated in cell proliferation. We describe a further mechanism of how cAMP enhances nuclear Erk1/2 signaling: It emanates from transphosphorylation of p21-activated kinases in their evolutionary conserved kinase-activation loop through GTP-Rac compartmentalized PKA activities. Sole transphosphorylation of p21-activated kinases is not sufficient to activate Erk1/2. It requires complex formation of both kinases with GTP-Rac1 to unleash cAMP-PKA–boosted activation of Raf-Mek-Erk. Consequently GTP-Rac functions as a dual kinase-tuning scaffold that favors the PKA holoenzyme and contributes to potentiate Erk1/2 signaling. Our findings offer additional mechanistic insights how β-adrenergic receptor-controlled PKA activities enhance GTP-Rac–mediated activation of nuclear Erk1/2 signaling

CRITERIAL MODEL OF ASSESSMENT OF THE QUALITY OF TREATMENT BY THE METHOD OF SYMPATHOCORRECTION

In this thesis proposed integral model quality evaluation method of treating ophthalmic diseases simpatokoretion. And proposed the template of the table of values of parameters

Возможности ультразвукового исследования в выявлении дивертикулита в условиях стационарного отделения скорой помощи

The aim of this prospective study was to evaluate ultrasound capabilities in differential diagnosis of intestinal diverticular disease, diverticulitis and other acute abdomen pathology.Material and methods. The study included 29 patients at the age of 48-95 years, which were admitted to emergency department with clinical symptoms of acute abdomen pain. All patients underwent complex clinical examination, comprising laboratory and instrumental diagnostic methods. Ultrasound of intestines was performed according to a specially developed step-by-step algorithm.Results. Sensitivity of the method was 68%, specificity 80%, accuracy 72.0%, PPT 86.0%, NPT 57.0%.Conclusion. Rather high diagnostic informative value and non-invasiveness of intestine's ultrasound allow to reconsider the sequence of instrumental methods of diagnosis for patients with suspicion on acute diverticulitis, and to consider ultrasound as a first line method of diagnosis.Цель исследования: оценка возможностей ультразвукового исследования в дифференциальной диагностике дивертикулярной болезни кишечника, диверти-кулитов и другой острой абдоминальной патологии.Материал и методы. В исследование включено 29 пациентов в возрасте от 48 до 95 лет, экстренно поступивших в стационар с клинической симптоматикой острого живота. Всем обследованным пациентам было выполнено комплексное клиническое исследование, включавшее в себя лабораторно-инструментальные методы исследования. Ультразвуковое исследование кишечника выполнялось по специально разработанному поэтапному алгоритму.Результаты. Чувствительность метода составила 68%, специфичность - 80,0%, точность - 72,0%, прогностическая ценность положительного результата -86,0%, прогностическая ценность отрицательного результата - 57,0%.Заключение. Достаточно высокая диагностическая информативность и неинвазивность ультразвукового исследования кишечника позволяют пересмотреть последовательность выполнения инструментальных методов обследования у пациентов с подозрением на острые дивертикулиты и рассматривать ультразвуковое исследование в качестве метода первой линии диагностики

Double-Stranded RNA Attenuates the Barrier Function of Human Pulmonary Artery Endothelial Cells

Circulating RNA may result from excessive cell damage or acute viral infection and can interact with vascular endothelial cells. Despite the obvious clinical implications associated with the presence of circulating RNA, its pathological effects on endothelial cells and the governing molecular mechanisms are still not fully elucidated. We analyzed the effects of double stranded RNA on primary human pulmonary artery endothelial cells (hPAECs). The effect of natural and synthetic double-stranded RNA (dsRNA) on hPAECs was investigated using trans-endothelial electric resistance, molecule trafficking, calcium (Ca2+) homeostasis, gene expression and proliferation studies. Furthermore, the morphology and mechanical changes of the cells caused by synthetic dsRNA was followed by in-situ atomic force microscopy, by vascular-endothelial cadherin and F-actin staining. Our results indicated that exposure of hPAECs to synthetic dsRNA led to functional deficits. This was reflected by morphological and mechanical changes and an increase in the permeability of the endothelial monolayer. hPAECs treated with synthetic dsRNA accumulated in the G1 phase of the cell cycle. Additionally, the proliferation rate of the cells in the presence of synthetic dsRNA was significantly decreased. Furthermore, we found that natural and synthetic dsRNA modulated Ca2+ signaling in hPAECs by inhibiting the sarco-endoplasmic Ca2+-ATPase (SERCA) which is involved in the regulation of the intracellular Ca2+ homeostasis and thus cell growth. Even upon synthetic dsRNA stimulation silencing of SERCA3 preserved the endothelial monolayer integrity. Our data identify novel mechanisms by which dsRNA can disrupt endothelial barrier function and these may be relevant in inflammatory processes

Diarrhea infections in north-eastern Ukraine: evolution of epidemic process

Abstract: Background: The significance of some infection sources, pathways of pathogen transmission and etiological structure of diarrhea infections (DI) have changed. Many issues of DI epidemiology are still insufficiently studied, which prevents the organisation of quality epidemiological surveillance and diseases control. Objectives: To study the DI epidemic situation (ES) in North- Eastern Ukraine and to identify the factors that determines the characteristics of epidemic process (EP). Material and Methods: The reports of Ministry of Health of Ukraine (1960- 2018) and Head Statistics Administration of Sumy Oblast (2001-2018) have been used. The biological properties of 40 strains of K. pneumoniae, 50 - S. aureus, 40 - E. cloacae recovered from the feces of patients with DI have been studied. Results: It has been found that the EP of DI is characterized by a sharp decrease in the incidence of typhoid fever and shigellosis, increase in the incidence of salmonellosis and dominance of DI caused by other specified or unspecified pathogens (SDI and UDI) in the nosological structure (p<0.05). The incidence of DI caused by Klebsiella, Staphylococus, Enterobacters exceeds the incidence of salmonellosis, shigellosis, typhoid fever (p<0.05). Opportunistic pathogens (OP), which are pathogens of DI have antilysozyme activity and adhesion ability, which proves their pathogenic potential. The demographics indirectly affect the incidence of DI. Access to water supply, sewerage, hot water supply is correlates with the incidence of DI. Conclusion: The system of epidemiological surveillance over DI in Ukraine needs improvement by optimisation its information and analytical subsystems aimed at objective epidemiological diagnostics and ES forecasting