The effect of Porphyromonas gingivalis infection on cytokine levels in type 2 diabetic mice

Several studies have shown that diabetes mellitus increases the severity of periodontitis. Conversely, periodontitis has been shown to have an impact on diabetes, although the underlying mechanisms of this are unclear. The aim of this study was to compare the inflammatory response to Porphyromonas gingivalis infection in normal and diabetic mice. Porphyromonas gingivalis were inoculated adjacent to the periosteum, at a point on the midline of the skull located between the ears, in C57BL/6 (normal) and KKAy (diabetic) mice. After induction, the levels of tumor necrosis factor-alpha, interleukin-6 and adiponectin in the mice were measured using real-time polymerase chain reaction and enzyme-linked immunosorbent assay. The KKAy mice showed significant increases in blood glucose, serum tumor necrosis factor-alpha and interleukin-6 levels after inoculation with Porphyromonas gingivalis, and a significant decrease in adiponectin to 35.7%. Similar results were observed at the mRNA level in liver and visceral adipose tissue. These observations suggest that tumor necrosis factor-alpha, interleukin-6 and adiponectin are an integral part of the link between diabetes mellitus and Porphyromonas gingivalis infection.