Activated human monocytes exhibit receptor-mediated adhesion to a non-enzymatically glycosylated protein substrate

Non-enzymatic glycosylation of proteins is thought to play an important role in the development of diabetic vascular disease. Advanced glycosylation end products have been shown to accumulate on basement membranes and collagen in diabetes, and receptors for such adducts have recently been found on murine macrophages. We have observed that human monocytes activated by endotoxin express receptors for advanced glycosylation end products of similar affinity and number as has been previously reported for murine macrophages. In addition, there is an increased adherence of activated human monocytes to a nonenzymatically glycosylated albumin substrate, and such adhesion can be competitively inhibited up to 50% by soluble, non-enzymatically glycosylated albumin. We suggest that increased adherence of activated monocytes to non-enzymatically glycosylated proteins in the vessel wall may result in monocyte stimulation and/or local monocyte accumulation and thereby contribute to vascular disease in diabetes.