A Periodontal pathogen Porphyromonas gingivalis deteriorates Isoproterenol-Induced myocardial remodeling in mice

Heart failure is a serious disease induced by several conditions, including hypertrophic cardiomyopathy. Although many reports suggest that there is an association between periodontal disease and cardiovascular disease, the mechanisms have yet to be elucidated. The purpose of this study was to clarify the relationship between periodontal disease and heart disease, especially in cardiac hypertrophy. We used C57BL/6J mice and implanted two types of subcutaneous chambers. First, we subcutaneously implanted a coil-shaped chamber into the back of a mouse. Porphyromonas gingivalis (P.g.), a major periodontal pathogen, was injected into the chamber. Then, an osmotic pump was implanted to infuse isoproterenol. Four weeks after the ISO infusion, we performed echocardiography and harvested the heart and blood. We measured the serum level of anti-P.g.-IgG using ELISA. The mRNA levels of several factors were measured using PCR. We found stronger cardiomyocyte hypertrophy in the ISO(+)/P.g.(+) mice compared with the ISO(+)/P.g.(−) mice. The total square of randomly selected cardiomyocytes was 23% larger in the ISO(+)/P.g.(+) mice than in the ISO(+)/P.g.(−) mice. We detected a higher level of mRNA expression in Toll-like receptor 2 and NADPH oxidase 4 in the ISO(+)/P.g.(−) mice compared with the control group. We revealed that a periodontal pathogen affected ISO-induced cardiac hypertrophy via oxidative stress.