Elucidation of mechanisms linking periodontitis to Alzheimer’s disease

Abstract

With the rapid increase in aging population, the number of elderlies with dementia in the world is estimated to exceed 160 million within 20 years. Alzheimer’s disease (AD) accounts for 70% of dementia, which 90% onset with aging. The brain pathologies of AD show amyloid β (Aβ)-aggregated senile plaques, Tau protein hyperphosphorylation-degenerated neurofibrils and microglial activation-related neuroinflammation. On the other hand, systemic inflammation which is associated with chronic inflammatory diseases, including rheumatoid arthritis, induces neuroinflammation resulting in promoting onset and progression of AD. Periodontitis is attracting attention as an aggravating factor for AD because the components of P.gingivalis, the major periodontal bacteria, has been detected in the AD autopsy brain. We are incorporating in elucidating the involvement of periodontitis in AD using the constructing analysis methods. The present review will outline the roles of systemic inflammation in AD, and introduce the involvement mechanisms of periodontitis in the onset and progression of AD.