Effect of Advanced Glycation End Product–Modified Albumin on Tissue Factor Expression by Monocytes

Abstract

Diabetes is associated with a hypercoagulable state that contributes to macrovascular complications, including cardiovascular events. The glycation reaction, a consequence of chronic hyperglycemia, has also been implicated in the pathogenesis of diabetic complications. Glycated proteins have receptors on monocytes and generate reactive oxygen species that can regulate the expression of a number of genes. As abnormal monocyte expression of tissue factor (TF), the main initiator of the coagulation cascade, is responsible for thrombosis in a number of clinical settings, we studied the effect of glycated albumin on monocyte TF expression. Mononuclear cells were incubated with glycated albumin for 24 hours, and monocyte TF activity was measured with a plasma recalcification time assay; TF antigen was measured by ELISA and TF mRNA by RT-PCR. Glycated albumin induced blood monocyte expression of the procoagulant protein TF at the mRNA level. Oxidative stress appeared to be involved in this effect, as the antioxidant N-acetylcysteine diminished TF mRNA accumulation in stimulated monocytes. Hydroxyl radicals, which may be generated inside cells from H2O2 via the Fenton reaction, also appeared to be involved in this effect, as hydroxyl radical scavengers downregulated TF activity and antigen levels (but not TF mRNA). Finally, the involvement of activated protein tyrosine kinase in the transmission of the signal from the membrane to the nucleus was suggested by the inhibitory effect of herbimycin A. These results point to a new mechanism for the hypercoagulability often described in diabetic patients and suggest that antioxidants or protein tyrosine kinase inhibitors might be of therapeutic value in this setting.

Serum Amyloid A Induces Monocyte Tissue Factor

“…Interaction of RAGE with its ligands activates NF-B through the ERK1/2 and p38 MAPK pathways, resulting in induction of proinflammatory genes and TF (55,56). We confirmed a requirement for these pathways.…”

“…Soluble RAGE [42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59] (sRAGE) and the reverse peptide were synthesized by manual solid-phase synthesis using 2-(1H-benzotriazole-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate-mediated couplings with Boc in situ neutralization chemistry (27) and purified by preparative reverse-phase HPLC using a C 18 column. Fractions containing the pure proteins were rerun on analytical HPLC, and masses were confirmed by electrospray ionization mass spectrometry (21,765.5 Ϯ 1.0, calculated: 2,177.2).…”

“…To determine whether induction may occur via RAGE, SAA or LPS was preincubated with sRAGE [42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59] peptide antagonist containing the RAGE ligand-binding domain, and PBMC was stimulated 2 h later. Fig.…”

Overexpression of the 78-kDa Glucose-regulated Protein/Immunoglobulin-binding Protein (GRP78/BiP) Inhibits Tissue Factor Procoagulant Activity

“…Infection with adenovirus, as well as other respiratory viruses, increases TF expression and procoagulant activity (PCA) (33). Growth factors (34) and cytokines (35,36), endotoxin (37,38), hypoxia (39), cell injury (40), reactive oxygen species (ROS) (41)(42)(43), oxidized LDL (44 -46), and increases in intracellular free Ca 2ϩ (47)(48)(49)(50) are also known to induce TF PCA in a variety of cell types, including vascular endothelial cells, smooth muscle cells, and circulating monocytes. Furthermore, the majority of tumor cells express TF (51)(52)(53)(54), and the prothrombotic state observed in cancer patients has been largely attributed to this expression (53).…”

Advanced glycation end products regulate extracellular matrix protein and protease expression by human glomerular mesangial cells

“…The protein concentration was measured with the Bradford method and AGE-specific fluorescence was determined at 420 nm after excitation at 350 nm by using an Aminco SPF 500 ratio spectrofluorometer (Photon Technology International) as described previously (22).…”