Angela M. Floden, Mona Sohrabi, Suba Nookala, Jay J. Cao and Colin K. Combs * Pages 1133 - 1144 ( 12 )
<P>Background: Beta amyloid (Aβ) peptide containing plaque aggregations in the brain are a hallmark of Alzheimer’s Disease (AD). However, Aβ is produced by cell types outside of the brain suggesting that the peptide may serve a broad physiologic purpose. </P><P> Objective: Based upon our prior work documenting expression of amyloid β precursor protein (APP) in intestinal epithelium we hypothesized that salivary epithelium might also express APP and be a source of Aβ. </P><P> Methods: To begin testing this idea, we compared human age-matched control and AD salivary glands to C57BL/6 wild type, App<sup>NL-G-F</sup> , and APP/PS1 mice. </P><P> Results: Both male and female AD, App<sup>NL-G-F</sup> , and APP/PS1 glands demonstrated robust APP and Aβ immunoreactivity. Female App<sup>NL-G-F</sup> mice had significantly higher levels of pilocarpine stimulated Aβ 1-42 compared to both wild type and APP/PS1 mice. No differences in male salivary Aβ levels were detected. No significant differences in total pilocarpine stimulated saliva volumes were observed in any group. Both male and female App<sup>NL-G-F</sup> but not APP/PS1 mice demonstrated significant differences in oral microbiome phylum and genus abundance compared to wild type mice. Male, but not female, APP/PS1 and App<sup>NL-G-F</sup> mice had significantly thinner molar enamel compared to their wild type counterparts. </P><P> Conclusion: These data support the idea that oral microbiome changes exist during AD in addition to changes in salivary Aβ and oral health.</P>
Microbiome, Alzheimer, amyloid, inflammation, saliva, biomarker.
Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND 58202-9037, Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND 58202-9037, Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND 58202-9037, USDA, Agricultural Research Service, Grand Forks Human Nutrition Research Center, Grand Forks, ND, Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND 58202-9037