scholarly journals Selectins—The Two Dr. Jekyll and Mr. Hyde Faces of Adhesion Molecules—A Review

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2835 ◽  
Author(s):  
Igor Tvaroška ◽  
Chandrabose Selvaraj ◽  
Jaroslav Koča
Keyword(s):  
Cancer Cells ◽  
Adhesion Molecules ◽  
Catalytic Mechanism ◽  
Inflammatory Responses ◽  
Inflammatory Diseases ◽  
Current Status ◽  
Biological Processes ◽  
Tissue Destruction ◽  
Non Covalent Interactions ◽  
Covalent Interactions

Selectins belong to a group of adhesion molecules that fulfill an essential role in immune and inflammatory responses and tissue healing. Selectins are glycoproteins that decode the information carried by glycan structures, and non-covalent interactions of selectins with these glycan structures mediate biological processes. The sialylated and fucosylated tetrasaccharide sLex is an essential glycan recognized by selectins. Several glycosyltransferases are responsible for the biosynthesis of the sLex tetrasaccharide. Selectins are involved in a sequence of interactions of circulated leukocytes with endothelial cells in the blood called the adhesion cascade. Recently, it has become evident that cancer cells utilize a similar adhesion cascade to promote metastases. However, like Dr. Jekyll and Mr. Hyde’s two faces, selectins also contribute to tissue destruction during some infections and inflammatory diseases. The most prominent function of selectins is associated with the initial stage of the leukocyte adhesion cascade, in which selectin binding enables tethering and rolling. The first adhesive event occurs through specific non-covalent interactions between selectins and their ligands, with glycans functioning as an interface between leukocytes or cancer cells and the endothelium. Targeting these interactions remains a principal strategy aimed at developing new therapies for the treatment of immune and inflammatory disorders and cancer. In this review, we will survey the significant contributions to and the current status of the understanding of the structure of selectins and the role of selectins in various biological processes. The potential of selectins and their ligands as therapeutic targets in chronic and acute inflammatory diseases and cancer will also be discussed. We will emphasize the structural characteristic of selectins and the catalytic mechanisms of glycosyltransferases involved in the biosynthesis of glycan recognition determinants. Furthermore, recent achievements in the synthesis of selectin inhibitors will be reviewed with a focus on the various strategies used for the development of glycosyltransferase inhibitors, including substrate analog inhibitors and transition state analog inhibitors, which are based on knowledge of the catalytic mechanism.

Osteopontin and Mucosal Protection

2006 ◽  
Vol 85 (5) ◽  
pp. 404-415 ◽  
Author(s):  
J. Sodek ◽  
A. Paes Batista Da Silva ◽  
R. Zohar
Keyword(s):  
Immune Cells ◽  
Barrier Function ◽  
Inflammatory Responses ◽  
Current Knowledge ◽  
Inflammatory Diseases ◽  
Biological Activities ◽  
Proteolytic Processing ◽  
Mucosal Inflammation ◽  
Tissue Destruction ◽  
Mucosal Tissues

Protection of mucosal tissues of the oral cavity, intestines, respiratory tract, and urogenital tract from the constant challenge of pathogens is achieved by the combined barrier function of the lining epithelia and specialized immune cells. Recent studies have indicated that osteopontin (OPN) has a pivotal role in the development of immune responses and in the tissue destruction and the subsequent repair processes associated with inflammatory diseases. While expression of OPN is increased in immune cells—including neutrophils, macrophages, T- and B-lymphocytes—and in epithelial, endothelial, and fibroblastic cells of inflamed tissues, deciphering the specific functions of OPN has been difficult. In part, this is due to the broad range of biological activities of OPN that are mediated by multiple receptors which recognize several signaling motifs whose activities are influenced by post-translational modifications and proteolytic processing of OPN. Understanding the role of OPN in mucosal inflammation is further complicated by its contributions to the barrier function of the lining epithelia and the complexity of the specialized mucosal immune system. In an attempt to provide some insights into the involvement of OPN in mucosal diseases, this review summarizes current knowledge of the biological activities of OPN involved in the development of inflammatory responses and in wound healing, and indicates how these activities may affect the protection of mucosal tissues.

scholarly journals Manifold Dynamic Non-Covalent Interactions for Steering Molecular Assembly and Cyclization

2021 ◽  
Author(s):  
Shaotang Song ◽  
Jie Su ◽  
Lulu Wang ◽  
Zhen Xu ◽  
Chia-Hsiu Hsu ◽  
...  
Keyword(s):  
Real Space ◽  
Molecular Assembly ◽  
Biological Processes ◽  
Chemical Transformations ◽  
Molecular Assemblies ◽  
Non Covalent Interactions ◽  
Covalent Interactions ◽  
Space Characterization

Deciphering rich non-covalent interactions that govern many chemical and biological processes is crucial for the design of drugs and controlling molecular assemblies and their chemical transformations. However, real-space characterization of...

NON COVALENT INTERACTIONS IN LARGE DIAMONDOID DIMERS IN THE GAS PHASE - A MICROWAVE STUDY

2017 ◽  
Author(s):  
Cristobal Perez ◽  
Melanie Schnell ◽  
Peter Schreiner ◽  
Norbert Mitzel ◽  
Yury Vishnevskiy ◽  
...  
Keyword(s):  
Gas Phase ◽  
Non Covalent Interactions ◽  
Covalent Interactions

Vapour Pressure Isotope Effect on Evaporation from Pure Organic Phases - a PIMD Approach

2020 ◽  
Author(s):  
Luis Vasquez ◽  
Agnieszka Dybala-Defratyka
Keyword(s):  
Path Integral ◽  
Vapour Pressure ◽  
Density Functional ◽  
Isotope Effects ◽  
Tight Binding ◽  
Decomposition Analysis ◽  
Energy Decomposition Analysis ◽  
Special Importance ◽  
Non Covalent Interactions ◽  
Covalent Interactions

<p></p><p>Very often in order to understand physical and chemical processes taking place among several phases fractionation of naturally abundant isotopes is monitored. Its measurement can be accompanied by theoretical determination to provide a more insightful interpretation of observed phenomena. Predictions are challenging due to the complexity of the effects involved in fractionation such as solvent effects and non-covalent interactions governing the behavior of the system which results in the necessity of using large models of those systems. This is sometimes a bottleneck and limits the theoretical description to only a few methods.<br> In this work vapour pressure isotope effects on evaporation from various organic solvents (ethanol, bromobenzene, dibromomethane, and trichloromethane) in the pure phase are estimated by combining force field or self-consistent charge density-functional tight-binding (SCC-DFTB) atomistic simulations with path integral principle. Furthermore, the recently developed Suzuki-Chin path integral is tested. In general, isotope effects are predicted qualitatively for most of the cases, however, the distinction between position-specific isotope effects observed for ethanol was only reproduced by SCC-DFTB, which indicates the importance of using non-harmonic bond approximations.<br> Energy decomposition analysis performed using the symmetry-adapted perturbation theory (SAPT) revealed sometimes quite substantial differences in interaction energy depending on whether the studied system was treated classically or quantum mechanically. Those observed differences might be the source of different magnitudes of isotope effects predicted using these two different levels of theory which is of special importance for the systems governed by non-covalent interactions.</p><br><p></p>

Biological Aspects and Clinical Applications of Mesenchymal Stem Cells: Key Features You Need to be Aware of.

2020 ◽  
Vol 21 ◽  
Author(s):  
Mohammad Saeedi ◽  
Muhammad Sadeqi Nezhad ◽  
Fatemeh Mehranfar ◽  
Mahdieh Golpour ◽  
Mohammad Ali Esakandari ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Cancer Cells ◽  
Immune Modulation ◽  
Adult Stem Cells ◽  
Inflammatory Diseases ◽  
High Capacity ◽  
Genetically Engineered ◽  
Cartilage Cells ◽  
Biological Aspects

: Mesenchymal stem cells (MSCs), a form of adult stem cells, are known to have a self-renewing property and the potential to specialize into a multitude of cells and tissues such as adipocytes, cartilage cells, and fibroblasts. MSCs can migrate and home to the desired target zone where inflammation is present. The unique characteristics of MSCs in repairing, differentiation, regeneration, and its high capacity of immune modulation has attracted tremendous attention for exerting them in clinical purposes, as they contribute to tissue regeneration process and anti-tumor activity. The MSCs-based treatment has demonstrated remarkable applicability towards various diseases such as heart and bone malignancies, and cancer cells. Importantly, genetically engineered MSCs, as a state-of-the-art therapeutic approach, could address some clinical hurdles by systemic secretion of cytokines and other agents with a short half-life and high toxicity. Therefore, understanding the biological aspects and the characteristics of MSCs is an imperative issue of concern. Herein, we provide an overview of the therapeutic application and the biological features of MSCs against different inflammatory diseases and cancer cells. We further shed light on MSCs physiological interaction, such as migration, homing, and tissue repairing mechanisms with different healthy and inflamed tissues.

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