Preliminary evidence for a link between periodontal disease and Alzheimer’s disease (AD)

1. Preliminary evidence for a link between periodontal disease and Alzheimer’s disease (AD) Sophie Poole, spoole@uclan.ac.ukOral & Dental Sciences Research Group,School of Postgraduate Medical & Dental Education, UCLan

2. Introduction • Alzheimer’s disease & Periodontal disease(s) are complex, multifactorial, progressive & inflammatory. • Clinical and epidemiological studies suggest that periodontitis may be a risk factor for Alzheimer’s disease. • Study purpose - to find evidence for a link between periodontal disease and AD. • There are an estimated 35.6 million people living with dementia in the world (World Alzheimer’s Report) • Rationale: Periodontal therapy from early age may delay onset and reduce the figure of AD patients significantly

3. 200 nm • Chronic Periodontal disease control Clinical features The lesion The main cause X-ray shows a periodontal Pocket (wound) – typically 109 bacteria 0.25 mm Pg, Tf, Td Porphyromonasgingivalis (Pg), Tannerellaforsythia (Tf), and Treponemadenticola (Td) are intimately associated with the disease. Bacteraemia: ref’s: Forner et al., 2006 J ClinPeriodontol 33:401-407 Gingival recession Gingivitis Pus Plaque & Calculus

4. Alzheimer’s disease Pathological features Specific-lesion • Inflammation Astrocytes & microglia Brains for Dementia Research: supplied peri-ventricular cerebral tissue, N = 10 sporadic AD cases and 5 = non-AD age matched controls

5. 4/10 AD cases show cellular immunolabelling to Pg-endotoxin(s) Cell surface membrane labelling with anti-Pg (LPS) CD14….x63 Red = PI nuclear stain. Green = moα pg1B5 detected by FITC conjugated secondary detection system Note: the cellular staining was only observed in 4 /10 AD cases only and NOT in the controls brains. However, there are only a few cells that are positive/case in 4/10 cases.

6. In-vitro assimilation SVGp12 in culture Negative control Anti-GFAP labelling CD14 labelling

7. Glial cells can adsorb LPS Duel labelling Red = GFAP, Green = LPS and nuclei = blue SGVp12 treated with 33277 spent med Spent med 33277 strain Control med only SGVp12 untreated cells E. Coli LPS only 76 52 38 31 24 17 12 anti-Pg (1B5) labelling on cells challenged with control Pg medium anti-Pg (1B5) labelling on cells challenged with Pg 33277 spent medium

8. LPS in AD cases Spent med 33277 strain Control med only SGVp12 untreated cells E. Coli LPS only SGVp12 spent med 33277 AD brain from case 3 AD brain from case 10 AD brain from case 8 AD brain from case 5 76 52 38 31 24 17 12 Loading control

9. NO LPS in NON-AD controls SGVp12 spent med 33277 Non-AD cont. brain 4 Non-AD cont. brain 1 Non-AD cont. brain 2 Non-AD cont. brain 3 Non-AD cont. brain 5 SGVp12 untreated cells Spent med 33277 strain Control med only 76 52 38 31 24 17 12 Loading control

10. Entry to the brain: Vascular channels The particles positively labeled with anti-Pg antibody are indicated in green (FITC) from an AD brain. The green staining was observed in the brain tissue and within blood vessels as shown by phase image overlaid on the dark field image.

11. Conclusions • Immunolabelling: 4/10 AD cases show P. gingivalisLPS in the brain. • The LPS from P. gingivalis strains does enter the brains of dementia patients and the likely route is the vascular channels. • In vitro study using the SV40 immortalised glialcell line (SVGp12) confirms that glial cells can adsorb LPS. • AD patients appear to be susceptible to PD pathogens and/ or their virulence factors

12. Acknowledgements