A murine model of accelerated periodontal disease in diabetes

Diabetes is a risk factor for periodontal disease in humans. In hyperglycemia, glycoxidation of proteins and lipids results in the formation of advanced glycation endproducts, or AGEs. The accumulation of AGEs in the plasma and tissues, and their interaction with their cellular receptor for AGE (RAGE), has been implicated in diabetic complications. In order to establish a model with which to delineate the specific host response factors that underlie the development of periodontal disease in diabetes, male C57BL/6J mice were rendered diabetic with streptozotocin. One month after documentation of diabetes or control state, mice were inoculated with the human periodontal pathogen Porphyromonas gingivalis, strain 381 (P. gingivalis) or treated with vehicle. Infection with P. gingivalis was achieved, as demonstrated by infiltration of gingival tissue with granulocytes, presence of DNA specific for P. gingivalis as well as increased serum antibody titer to P. gingivalis. At 2 and 3 months after infection, increased alveolar bone loss was demonstrated in P. gingivalis-inoculated diabetic vs. non-diabetic mice, along with enhanced tissue-destructive capacity, as demonstrated by increased collagenolytic activity in gingival extracts. Consistent with an important role for AGE-RAGE interaction, increased AGE deposition and expression of vascular and monocyte RAGE were demonstrated in diabetic gingiva compared with non-diabetic controls. Taken together, these data indicate that we have established a murine model of enhanced periodontal disease in diabetes. This model will serve to delineate molecular mechanisms which account for the increased susceptibility of diabetic patients to periodontal disease.