Cell matrix contact modifies endothelial major histocompatibility complex class II expression in high-glucose environment

Abstract

Atherosclerosis is a chronic inflammatory disease. Cardiovascular risk factors such as hyperglycemia, hyperlipidemia, and arterial hypertension induce endothelial dysfunction with alterations in endothelial biosecretion and immune behavior. The aim of this study is to elucidate whether glucose-induced modifications of endothelial biosecretory and immune functions are regulated by interactions of endothelial cells (ECs) with their extracellular matrix [ECs plated on polystyrene-coated tissue culture plates (TC-EC) vs. ECs embedded within three-dimensional (3-D) collagen-based matrixes (3D-EC)]. In the absence of glucose, IFN-γ-induced phosphorylation of JAK and STAT proteins and human leukocyte antigen (HLA)-DR expression were lower in 3D-EC compared with TC-EC. Inversely, the expression of suppressor of cytokine signaling proteins (SOCS)-1 and -3 were significantly higher in naïve 3D-EC compared with naïve TC-EC. IFN-γ-induced upregulation of SOCS proteins was further amplified by the 3-D environment. Glucose significantly augmented IFN-γ-dependent signaling pathways in TC-EC. IFN-γ-induced phosphorylation of JAK and STAT proteins as well as HLA-DR expression by ECs in low- and high-glucose medium was significantly lower in 3-D than in two-dimensional environment. Glucose increased SOCS expression in TC-EC and 3D-EC to the same extent, such that expression levels in 3D-EC exceeded SOCS-1 and -3 expression in TC-EC by 1.6–2.5-fold. In conclusion, low- and high-glucose concentrations amplify IFN-γ-induced signaling pathways in TC-EC. Increased SOCS expression raises the threshold for IFN-γ to induce HLA-DR expression in a 3-D environment. This immunoprotective effect is maintained even in states of experimental hyperglycemia.

CD34+ circulating cells display signs of immune activation in patients with acute coronary syndrome

“…Over the course of atherosclerotic lesion development ECs become injured and immune activated [19]. Immunogenicity of ECs is intertwined with quality of basement membrane contact [19][20][21][22], as liberation of vasculature-derived ECs from the extracellular matrix and changes in composition and spatial formation have been linked with expression of adhesion and costimulatory molecules, HLA-DR expression as well as thrombogenicity. These findings have been extended to epithelial cells and bone marrow residing ECs [23,24].…”

Glt25d2 Knockout Directly Increases CD25+CD69– but Decreases CD25–CD69+ Subset Proliferation and is Involved in Concanavalin-Induced Hepatitis

“…Some ECM components, such as proteoglycans, can also act as signaling molecules, endogenous ligands of Toll-like receptors, activators of the innate immune response, and mediate activators of the adaptive immune response during inflammation [4,5]. The ECM can also modify major histocompatibility complex class II expression in the pathological state [6].…”