Integrins as therapeutic targets: lessons and opportunities.

The integrins are a large family of cell adhesion molecules that are essential for the regulation of cell growth and function. The identification of key roles for integrins in a diverse range of diseases, including cancer, infection, thrombosis and autoimmune disorders, has revealed their substantial potential as therapeutic targets. However, so far, pharmacological inhibitors for only three integrins have received marketing approval. This article discusses the structure and function of integrins, their roles in disease and the chequered history of the approved integrin antagonists. Recent advances in the understanding of integrin function, ligand interaction and signalling pathways suggest novel strategies for inhibiting integrin function that could help harness their full potential as therapeutic targets

Endothelial progenitor cells and integrins: adhesive needs

In the last decade there have been multiple studies concerning the contribution of endothelial progenitor cells (EPCs) to new vessel formation in different physiological and pathological settings. The process by which EPCs contribute to new vessel formation in adults is termed postnatal vasculogenesis and occurs via four inter-related steps. They must respond to chemoattractant signals and mobilize from the bone marrow to the peripheral blood; home in on sites of new vessel formation; invade and migrate at the same sites; and differentiate into mature endothelial cells (ECs) and/or regulate pre-existing ECs via paracrine or juxtacrine signals. During these four steps, EPCs interact with different physiological compartments, namely bone marrow, peripheral blood, blood vessels and homing tissues. The success of each step depends on the ability of EPCs to interact, adapt and respond to multiple molecular cues. The present review summarizes the interactions between integrins expressed by EPCs and their ligands: extracellular matrix components and cell surface proteins present at sites of postnatal vasculogenesis. The data summarized here indicate that integrins represent a major molecular determinant of EPC function, with different integrin subunits regulating different steps of EPC biology. Specifically, integrin α4β1 is a key regulator of EPC retention and/or mobilization from the bone marrow, while integrins α5β1, α6β1, αvβ3 and αvβ5 are major determinants of EPC homing, invasion, differentiation and paracrine factor production. β2 integrins are the major regulators of EPC transendothelial migration. The relevance of integrins in EPC biology is also demonstrated by many studies that use extracellular matrix-based scaffolds as a clinical tool to improve the vasculogenic functions of EPCs. We propose that targeted and tissue-specific manipulation of EPC integrin-mediated interactions may be crucial to further improve the usage of this cell population as a relevant clinical agent

Substituent effects and solvents

The source data matrix containing 428 data series describing substituent effects from meta and para position (25 substituents from both position) in water, protic and aprotic solvents was investigated by using conjugated deviation analysis and principal component analysis. The results obtained for both meta and para substituted substrates, in three types of solvents, allowed to compare the influence of solvents on substituent effects

Photophysical properties of acid-responsive triphenylamine derivatives bearing pyridine fragments: Towards white light emission

International audienceThe synthesis, thermal, electrochemical, and optical properties of a series of triphenylamine derivatives bearing pyridine fragments and their trifluoroacetate salts are described. A dramatic increase in the intramolecular charge transfer is observed upon protonation, as evidenced by a significant reduction in the HOMO-LUMO gap and a red shift of both the absorption and the emission band. White photoluminescence was obtained in solution by the controlled protonation of blue emitting pyridine derivatives, which resulted in the yellow-orange emissive acidified form. In the solid state the emission color of doped polystyrene thin films could be tuned from steel blue to lawn green when the ratio of the protonated form was increased. These compounds have potential applications in the fabrication of multi-color OLEDs based on only one material. © 2017 Elsevier Lt