The role of AGEs for the pathogenesis of osteopenia in diabetes mellitus

Abstract

Osteopenia was reported in patients with type I diabetes mellitus (DM). Also, serum levels of advanced glycation endproducts (AGEs) were reported to be elevated in DM. In this review, we showed the effect of AGEs on primary human osteoblasts, the precursor of human osteoclast like cells and parathyroid cells in culture. AGEs were made from incubating bovine serum albumin with glucose 6 phosphate for 8 weeks (AGEs-BSA). AGEs-BSA (1,000 microg/mL) showed inhibitory effect for human osteoblasts in terms of the productions of procolagen c propeptide and osteocalcin, which were regarded as bone forming parameters. On the other hand, the same concentration of AGEs-BSA inhibited the increase in the parathyroid hormone secretion from the cultured human parathyroid cells induced by low calcium medium concentration. AGEs-BSA increased time dependently intracellular calcium levels of HEK 293 cells, which expressed the wild type human calcium-sensing receptor. Also, AGEs-BSA increased IL-6 synthesis by primary human osteoblast. Our preliminary data also showed that AGEs-BSA increased osteoclast-like cells formation in number from the osteoclast precursor rich bone marrow cells. These data suggested the important role of AGEs for the pathogenesis of osteopenia in patients with DM through decreased bone formation and increased bone resorption.