Endothelial Dysfunction as a Consequence of Endothelial Glycocalyx Damage: A Role in the Pathogenesis of Preeclampsia

The endothelial glycocalyx is an intravascular compartment which consists of carbohydrate part of membrane glycoconjugates, free proteoglycans and associated proteins. It is thought to play an important role in the vascular tone regulation, vascular permeability and thromboresistance. It was suggested that the leading cause of endothelial dysfunction in various cardiovascular, inflammatory, and kidney diseases is the damage of the endothelial glycocalyx. This review presents the changes in the composition and structure of the endothelial glycocalyx in the settings of damage and under systemic inflammatory response, and the impact of these changes on the functions of endothelial cells and intercellular contacts, mediating the interaction of endothelium and the immune cells. The second issue, discussed in this article is a possible role of endothelial glycocalyx in the pathogenesis of preeclampsia—a complication of pregnancy associated with hypertension, proteinuria and edema. The reviewed data contribute a new insight in the endothelial dysfunction pathogenesis

Impact of human bladder cancer cell architecture on autologous T-lymphocyte activation

To investigate the influence of tumor cell architecture on T-cell activation, we used an autologous human model based on 2 bladder tumor cell lines as targets for cytotoxic tumor-infiltrating lymphocytes (TILs). These tumor cell lines were grown in vitro as either standard 2-dimensional (2D) monolayers or 3-dimensional (3D) spheroids. T-cell activation was determined by measuring the production of three major cytokines (tumor necrosis factor, granulocyte/macrophage colony-stimulating factor and interferon-gamma), known to be secreted by most activated TILs. Changes in the architecture of target cells from 2D to 3D induced a dramatic decrease in their capacity for stimulating TILs. Interestingly, neither TIL infiltration nor MHC class I, B7.1 costimulatory or lymphocyte function-associated factor-3 adhesion molecule downregulation played a major role in this decrease. These findings demonstrate that tumor architecture has a major impact on T-cell activation and might be implicated in the escape of tumor cells from the immune system

Lectin ligands: New insights into their conformations and their dynamic behavior and the discovery of conformer selection by lectins

The mysteries of the functions of complex glycoconjugates have enthralled scientists over decades. Theoretical considerations have ascribed an enormous capacity to store information to oligosaccharides, In the interplay with lectins sugar-code words of complex carbohydrate structures can be deciphered. To capitalize on knowledge about this type of molecular recognition for rational marker/drug design, the intimate details of the recognition process must be delineated, To this aim the required approach is garnered from several fields, profiting from advances primarily in X-ray crystallography, nuclear magnetic resonance spectroscopy and computational calculations encompassing molecular mechanics, molecular dynamics and homology modeling. Collectively considered, the results force us to jettison the preconception of a rigid ligand structure. On the contrary, a carbohydrate ligand may move rather freely between two or even more low-energy positions, affording the basis for conformer selection by a lectin. By an exemplary illustration of the interdisciplinary approach including up-to-date refinements in carbohydrate modeling it is underscored why this combination is considered to show promise of fostering innovative strategies in rational marker/drug design

Phylogenetic and structural analysis of annexins in pea (<i>Pisum sativum</i> L.) and their role in legume-rhizobial symbiosis development

Annexins as Ca2+/phospholipid-binding proteins are involved in the control of many biological processes essential for plant growth and development. In a previous study, we had shown, using a proteomic approach, that the synthesis of two annexins is induced in pea roots in response to rhizobial inoculation. In this study, phylogenetic analysis identified these annexins as PsAnn4 and PsAnn8 based on their homology with annexins from other legumes. The modeling approach allowed us to estimate the structural features of these annexins that might influence their functional activity. To verify the functions of these annexins, we performed comparative proteomic analysis, experiments with calcium influx inhibitors, and localization of labeled proteins. Essential down-regulation of PsAnn4 synthesis in a non-nodulating pea mutant P56 (sym10) suggests an involvement of this annexin in the rhizobial symbiosis. Quantitative RT-PCR analysis showed that PsAnn4 was upregulated at the early stages of symbiosis development, starting from 1–3 days after inoculation to up to 5 days after inoculation, while experiments with the Ca2+ channel blocker LaCl3 revealed its negative influence on this expression. To follow the PsAnn4 protein localization in plant cells, it was fused to the fluorophores such as red fluorescent protein (RFP) and yellow fluorescent protein (YFP) and expressed under the transcriptional regulation of the 35S promoter in Nicotiana benthamiana leaves by infiltration with Agrobacterium tumefaciens. The localization of PsAnn4 in the cell wall or plasma membrane of plant cells may indicate its participation in membrane modification or ion transport. Our results suggest that PsAnn4 may play an important role during the early stages of pea-rhizobial symbiosis development

Neoglycolipids Micelle-like Structures as a Basis for Drug Delivery Systems

Targeted drug delivery is one of the most promising tasks of nanomedicine, as this is a real way to increase the effectiveness of therapeutic effects against many diseases. In this regard, the development of new inexpensive highly effective stimulating and non-immunogenic drug delivery systems (DDS) is of great importance. In this work new molecular candidates were proposed and studied for the creation of such systems based on the use of new compounds, neoglycolipids. It is shown that these compounds are capable of self-association in aqueous solutions and can serve as potential carriers of drug compounds with targeted delivery determined by their terminal groups (in particular, glycans). The processes of their associates formation and features of their structure are investigated. The results show that these selforganizing nanoscale systems can be used as a basis for developing new drug delivery systems. Keywords: neoglycolipids, micelle-like structures, small-angle X-ray scattering, molecular dynamics simulatio

Influence of protein (human galectin-3) design on aspects of lectin activity

The concept of biomedical significance of the functional pairing between tissue lectins and their glycoconjugate counterreceptors has reached the mainstream of research on the flow of biological information. A major challenge now is to identify the principles of structure–activity relationships that underlie specificity of recognition and the ensuing post-binding processes. Toward this end, we focus on a distinct feature on the side of the lectin, i.e. its architecture to present the carbohydrate recognition domain (CRD). Working with a multifunctional human lectin, i.e. galectin-3, as model, its CRD is used in protein engineering to build variants with different modular assembly. Hereby, it becomes possible to compare activity features of the natural design, i.e. CRD attached to an N-terminal tail, with those of homo- and heterodimers and the tail-free protein. Thermodynamics of binding disaccharides proved full activity of all proteins at very similar affinity. The following glycan array testing revealed maintained preferential contact formation with N-acetyllactosamine oligomers and histo-blood group ABH epitopes irrespective of variant design. The study of carbohydrate-inhibitable binding of the test panel disclosed up to qualitative cell-type-dependent differences in sections of fixed murine epididymis and especially jejunum. By probing topological aspects of binding, the susceptibility to inhibition by a tetravalent glycocluster was markedly different for the wild-type vs the homodimeric variant proteins. The results teach the salient lesson that protein design matters: the type of CRD presentation can have a profound bearing on whether basically suited oligosaccharides, which for example tested positively in an array, will become binding partners in situ. When lectin-glycoconjugate aggregates (lattices) are formed, their structural organization will depend on this parameter. Further testing (ga)lectin variants will thus be instrumental (i) to define the full range of impact of altering protein assembly and (ii) to explain why certain types of design have been favored during the course of evolution, besides opening biomedical perspectives for potential applications of the novel galectin forms

Locally targeted cytoprotection with dextran sulfate attenuates experimental porcine myocardial ischaemia/reperfusion injury

Aims Intravascular inflammatory events during ischaemia/reperfusion injury following coronary angioplasty alter and denudate the endothelium of its natural anticoagulant heparan sulfate proteoglycan (HSPG) layer, contributing to myocardial tissue damage. We propose that locally targeted cytoprotection of ischaemic myocardium with the glycosaminoglycan analogue dextran sulfate (DXS, MW 5000) may protect damaged tissue from reperfusion injury by functional restoration of HSPG. Methods and results In a closed chest porcine model of acute myocardial ischaemia/reperfusion injury (60 min ischaemia, 120 min reperfusion), DXS was administered intracoronarily into the area at risk 5 min prior to reperfusion. Despite similar areas at risk in both groups (39±8% and 42±9% of left ventricular mass), DXS significantly decreased myocardial infarct size from 61±12% of the area at risk for vehicle controls to 39±14%. Cardioprotection correlated with reduced cardiac enzyme release creatine kinase (CK-MB, troponin-I). DXS abrogated myocardial complement deposition and substantially decreased vascular expression of pro-coagulant tissue factor in ischaemic myocardium. DXS binding, detected using fluorescein-labelled agent, localized to ischaemically damaged blood vessels/myocardium and correlated with reduced vascular staining of HSPG. Conclusion The significant cardioprotection obtained through targeted cytoprotection of ischaemic tissue prior to reperfusion in this model of acute myocardial infarction suggests a possible role for the local modulation of vascular inflammation by glycosaminoglycan analogues as a novel therapy to reduce reperfusion injur