Preferential recognition of advanced glycation end products by serum antibodies and low-grade systemic inflammation in diabetes mellitus and its complications.

BACKGROUND: Advanced glycation end products (AGEs) have shown to possess antigenicity. This study analyzes the detrimental effect of non-enzymatic glycation on human serum albumin (HSA) leading to the production of antibodies.

METHODS: HSA (20 μM) incubated with d-glucose formed AGEs confirmed by scanning electron microscopy (SEM). DNA-damage was assessed with comet assay. Antibodies against in-vitro formed AGEs was evaluated in the sera of diabetic patients by enzyme-linked immunosorbent assay. Molecular docking was performed to demonstrate affinity of native and glycated-HSA with IgG. Low-grade systemic inflammation was quantified with IL-4, IL-6, TNF-α and NF-кβ in serum and mRNA expression.

RESULTS: Scanning Electron Microscopy showed the formation of aggregates in glycated-HSA. Comet assay showed DNA damage T2DM with CKD. Serum auto-antibodies in diabetes patients with chronic kidney disease (CKD) showed appreciably high recognition with glycated-HSA compared to native HSA. Molecular docking showed less affinity of glycated-HSA with IgG. Serum IL-4, IL-6, and TNF-α were found significantly higher in T2DM with CKD compared to T2DM and healthy ones. mRNA expression of IL-4, IL-6 and NF-кβ are also found significantly higher in T2DM with CKD.

CONCLUSION: The non-enzymatic glycation-induced damage to the HSA generate neo-epitopes that possess immunogenic response and low-grade systemic inflammation.