The detection of amyloid-β peptides in gingival crevicular fluid and its influence on oral pathogens

Abstract Objective Periodontitis is the most prevalent oral inflammatory disease, contributing to the onset and progression of Alzheimer’s disease. However, the expression level of amyloid-β (Aβ) peptide in gingival crevicular fluid (GCF) and its effects on oral pathogens have not been studied adequately. This study aimed to analyze the expression level of Aβ peptides in GCF of periodontitis patients and the effects of Aβ peptides against common oral pathogens. Methods GCF samples were collected from patients with periodontitis (n = 15) and periodontally healthy people (n = 10). Four common oral pathogenic strains were used to evaluate the antibacterial effect of Aβ peptides via an MTT assay, Crystal Violet Staining, fluorescence microscope, and transmission electron microscope. Results The protein level of Aβ40 and Aβ42 in the GCF of periodontitis group was up-regulated compared with the healthy group. Both Aβ40 and Aβ42 exhibited antibacterial effects on Porphyromonas gingivalis , Aggregatibacter actinomycetemcomitans , and Lactobacillus acidophilus in both planktonic and biofilm conditions. Further, Aβ40 showed an antibacterial effect on the biofilm of Fusobacterium nucleatum . Conclusions This study's findings demonstrate that Aβ peptides in GCF could be an indicator associated with the status of periodontitis. Further, the antimicrobial peptides derived from Aβ peptides have great potential in periodontal therapy.