Periodontal Bacteria Aggravate Chronic Renal Failure Induced by Subtotal Nephrectomy in Mice

Periodontitis is associated with several systemic disorders, such as diabetes, cardiovascular disease and chronic kidney disease (CKD). However, the pathophysiological relationship between periodontitis and CKD is yet to be elucidated. We assessed the hypothesis that periodontal bacteria influence renal dysfunction. We used C57BL/6J mice and implanted chambers subcutaneously in the back of each mouse. Two weeks after implantation, we injected Porphyromonas gingivalis (P.g.), which is a major periodontal pathogen, or phosphate-buffered saline (PBS) into the chamber. The subcutaneous injections were administered once a week for 6 weeks during the observation period. 5/6 nephrectomy (NTX) was made by a two-step surgical procedure. The levels of anti-P.g. IgG in the serum were determined with an ELISA. After the operation, we measured serum creatinine using an enzymatic method. On day 28, mice were sacrificed and pathological evaluation was also performed. The repeated bacterial injections elevated the serum level of anti-P.g. IgG significantly. NTX increased the serum creatinine level (0.35 ± 0.02mg/dl) compared to native mice (0.15 ± 0.01mg/dl). Neither infection altered creatinine levels (P.g. 0.41 ± 0.04mg/dl) (n = 15) compared to the PBS injected group (n = 20). On days 1, 3 and 7, serum creatinine levels were significantly increased in the P.g. injected group compared to the PBS injected group. Of note, P.g. infection deteriorated 28 days survival rate (46.9%, p<0.05) compared to the PBS injected group (90.9%). It was suggested that periodontal pathogens deteriorated serum creatinine levels and the survival rate after NTX.