Porphyromonas gingivalis in Alzheimer's disease brains: Evidence for disease causation and treatment with small-molecule inhibitors

Stephen S Dominy, Casey Lynch, Florian Ermini, Malgorzata Benedyk, Agata Marczyk, Andrei Konradi, Mai Nguyen, Ursula Haditsch, Debasish Raha, Christina Griffin, Leslie J Holsinger, Shirin Arastu-Kapur, Samer Kaba, Alexander Lee, Mark I Ryder, Barbara Potempa, Piotr Mydel, Annelie Hellvard, Karina Adamowicz, Hatice Hasturk, Glenn D Walker, Eric C Reynolds, Richard L M Faull, Maurice A Curtis, Mike Dragunow, Jan Potempa, Stephen S Dominy, Casey Lynch, Florian Ermini, Malgorzata Benedyk, Agata Marczyk, Andrei Konradi, Mai Nguyen, Ursula Haditsch, Debasish Raha, Christina Griffin, Leslie J Holsinger, Shirin Arastu-Kapur, Samer Kaba, Alexander Lee, Mark I Ryder, Barbara Potempa, Piotr Mydel, Annelie Hellvard, Karina Adamowicz, Hatice Hasturk, Glenn D Walker, Eric C Reynolds, Richard L M Faull, Maurice A Curtis, Mike Dragunow, Jan Potempa

Abstract

Porphyromonas gingivalis, the keystone pathogen in chronic periodontitis, was identified in the brain of Alzheimer's disease patients. Toxic proteases from the bacterium called gingipains were also identified in the brain of Alzheimer's patients, and levels correlated with tau and ubiquitin pathology. Oral P. gingivalis infection in mice resulted in brain colonization and increased production of Aβ1-42, a component of amyloid plaques. Further, gingipains were neurotoxic in vivo and in vitro, exerting detrimental effects on tau, a protein needed for normal neuronal function. To block this neurotoxicity, we designed and synthesized small-molecule inhibitors targeting gingipains. Gingipain inhibition reduced the bacterial load of an established P. gingivalis brain infection, blocked Aβ1-42 production, reduced neuroinflammation, and rescued neurons in the hippocampus. These data suggest that gingipain inhibitors could be valuable for treating P. gingivalis brain colonization and neurodegeneration in Alzheimer's disease.

Figures

Fig. 1. Gingipain IR in brain correlates…
Fig. 1. Gingipain IR in brain correlates with AD diagnosis and pathology.
(A and B) Representative TMA NVD005 containing brain tissue cores from the MTG of AD patients and controls probed for RgpB (A) and Kgp (B) with antibodies CAB101 and CAB102, respectively. Higher magnification of representative tissue cores reveals higher neuronal RgpB-IR and Kgp-IR in AD tissue cores than in control cores. (C) RgpB-IR and (D) Kgp-IR data from TMAs NVD005 and NVD003 show significantly higher load in AD brain compared to controls. Mann-Whitney test, ***P < 0.0001; presented as geometric mean ± 95% confidence interval, n = 99 (C) and n = 104 (D). (E and F) Tau load correlates to RgpB load (Spearman r = 0.674, P < 0.0001, n = 84) (E) and Kgp load (Spearman r = 0.563, P < 0.0001, n = 89) (F). Blue, control; red, AD. (G and H) Ubiquitin load, a marker of AD pathology, correlates to RgpB load (blue, control; red, AD; Spearman r = 0.786, P < 0.0001, n = 99) (G) and Kgp load (Spearman r = 0.572, P < 0.0001, n = 104) (H). (I) RgpB load correlates with Kgp load (Spearman r = 0.610, P < 0.0001, n = 99).
Fig. 2. RgpB colocalizes with neurons and…
Fig. 2. RgpB colocalizes with neurons and pathology in AD hippocampus.
(A) IHC using RgpB-specific monoclonal antibody 18E6 (representative images from a 63-year-old AD patient). The hippocampus shows abundant intracellular RgpB in the hilus (1), CA3 pyramidal layer (2), granular cell layer (3), and molecular layer (4). High-magnification images from the indicated areas (1 to 4) exhibit a granular staining pattern consistent with P. gingivalis intracellular infection. Scale bars, 200 μm (overview), 50 μm (1), and 10 μm (2 to 4). (B) AD hippocampus stained with 18E6 (AD) compared to gingival tissue (gingiva) from a patient with periodontal disease as well as a non-AD control and mouse IgG1 control (IgG1) in an adjacent hippocampal section. Scale bars, 50 μm. (C) Immunofluorescent colabeling with CAB101 reveals granular intraneuronal staining for RgpB (arrows) in MAP2-positive neurons in both the granular cell layer (GCL) and the pyramidal cell layer (CA1). Scale bars, 10 μm. (D) Dense extracellular RgpB-positive aggregates (arrowheads) were closely associated with astrocytes [glial fibrillary acidic protein (GFAP)]. There was no observed association of RgpB with microglia (IBA1). Scale bars, 10 μm. (E) RgpB was associated with paired helical filament Tau (PHF-Tau; arrows). RgpB-positive neurons negative for PHF-Tau (arrowheads) were also seen. Intracellular Aβ was often colocalized with RgpB (arrows). In some Aβ-positive cells, RgpB could not be detected (arrowheads). Scale bars, 10 μm.
Fig. 3. Identification of P. gingivalis –specific…
Fig. 3. Identification of P. gingivalis–specific protein and DNA in cortex from control and AD patients.
(A) WB with four different strains of P. gingivalis and CAB102 detection of typical molecular weight bands for Kgp in bacterial lysates. (B) IP using brain lysates from nondemented controls (C1 to C6; ages 75, 54, 63, 45, 37, and 102 years, respectively) and AD patients (AD1 to AD3; ages 83, 90, and 80 years, respectively) using CAB102 with subsequent WB reveals the ~50-kDa Kgp catalytic subunit (Kgpcat), along with higher– and lower–molecular weight Kgp species seen in (A). (C) qPCR from DNA isolated from the same brain lysates as the protein samples analyzed in (B) shows a positive signal in nondemented control (C1 to C5) and AD (AD1 to AD3) samples. Sample C6 from the 102-year-old nondemented control patient had no detectable qPCR signal in (C) and very faint bands indicating near absence of Kgp (B) (mean with SEM error bars of repeat qPCR runs).
Fig. 4. Detection of P. gingivalis in…
Fig. 4. Detection of P. gingivalis in CSF and oral biofluids from clinical AD subjects.
(A) Detection and quantitation of P. gingivalis DNA by qPCR in CSF from subjects with probable AD. (B) Detection and quantitation of P. gingivalis DNA by qPCR from matching saliva samples. (C) Top: PCR products detecting P. gingivalis from CSF in (A) from all subjects run on agarose gel including negative and positive controls containing a synthetic DNA template. Faint or undetectable PCR products from subjects AD1, AD3, and AD5 were below the limit of quantitation for copy number and not of sufficient quantity for sequence analysis. Bottom: qPCR products from CSF from the same subjects for H. pylori. (D) Data table includes age and Mini Mental Status Exam (MMSE) score on subjects and sequence identity of PCR products to P. gingivalis hmuY DNA sequence. Sequence data are included in fig. S4. NS, not sequenced.
Fig. 5. P. gingivalis and gingipains fragment…
Fig. 5. P. gingivalis and gingipains fragment tau.
(A) WB analysis of total soluble tau in SH-SY5Y cells infected with increasing concentrations of wild-type (WT) P. gingivalis strain W83 (P.g.) and P. gingivalis gingipain-deficient mutants either lacking Kgp activity (KgpΔIg-B) or lacking both Kgp and Rgp activity (ΔK/ΔRAB-A). Uninfected SH-SY5Y cells (No P.g.) were used as a negative control. Glyceraldehyde-phosphate dehydrogenase (GAPDH) was used as a loading control. Total tau was monitored with the monoclonal antibody Tau-5 at 1, 4, and 8 hours after infection. (B) Densitometry analysis of the total tau WB images. (C) WB analysis of rtau-441 incubated with purified Kgp and RgpB catalytic domains combined (Gp) at various concentrations for 1 hour at 37°C. The blot was probed with tau monoclonal antibody T46. (D) Gingipain cleavage sites in rtau-441 deduced from peptide fragments identified by MS for rtau-441 incubated with 1 or 10 nM gingipains. (a) T46 antibody epitope (red). (b) Tau-5 antibody epitope (red). (c) N-terminal tau fragment. (d) C-terminal tau fragment. (e) Kgp-generated tau fragments containing the VQIVYK sequence. (f) Kgp-generated fragments containing the VQIINK sequence. (g) An RgpB-generated tau fragment. *Cleavage sites identified at 1 nM gingipains.
Fig. 6. Small-molecule gingipain inhibitors protect neuronal…
Fig. 6. Small-molecule gingipain inhibitors protect neuronal cells against P. gingivalis– and gingipain-induced toxicity in vitro and in vivo.
(A) Differentiated SH-SY5Y neuroblastoma cells demonstrate cell aggregation after exposure to RgpB (10 μg/ml), Kgp (10 μg/ml), or both for 24 hours. The nonselective cysteine protease inhibitor iodoacetamide (IAM) blocks the gingipain-induced cell aggregation. (B) AlamarBlue viability assay shows that P. gingivalis (P.g.) is toxic to SH-SY5Y cells (MOI of 400) and that the small-molecule Kgp inhibitor COR271 and the RgpB inhibitor COR286 provide dose-dependent protection. The broad-spectrum antibiotics moxifloxacin and doxycycline and the γ-secretase inhibitor semagacestat did not inhibit the cytotoxic effect of P. gingivalis. (C) Fluoro-Jade C (FJC) staining (green) in pyramidal neurons of the CA1 region of the mouse hippocampus indicates neurodegeneration after stereotactic injection of gingipains. Counterstain with 4′,6-diamidino-2-phenylindole (DAPI) (blue). Scale bars, 50 μm. (D) The total number of FJC-positive cells was determined from serial section through the entire hippocampus. Results demonstrate a significant neuroprotective effect of gingipain inhibitors COR271 + COR286 after acute gingipain exposure in the hippocampus (*P < 0.05, n = 14). All graphs show the mean with SEM error bars.
Fig. 7. P. gingivalis invasion of the…
Fig. 7. P. gingivalis invasion of the brain induces an Aβ1–42 response that is blocked by gingipain inhibition in mice.
(A) P. gingivalis PCR product in mouse brains after oral infection with P. gingivalis W83, with or without treatment with the Kgp inhibitor COR119, or infection with gingipain knockout strain ΔRgpB or ΔKgp. Lanes 1 to 8 represent individual experimental animals. In the first lane (P.g.), P. gingivalis W83 was used as a positive control. (B) P. gingivalis W83–infected mice, but not COR119-treated mice or mice infected with gingipain knockouts, had significantly higher Aβ1–42 levels compared to mock-infected mice (***P < 0.001, n = 40). (C) RgpB-IR (red) colocalized with Aβ1–42-IR (green) on the surface of P. gingivalis (D) Aβ1–42, but not Aβ1–40 or Aβ1–42 scrambled, decreased viability of P. gingivalis (***P < 0.001, n = 12). (E) Study design to quantitate the effect of gingipain inhibitors on brain P. gingivalis load. (F) qPCR results showed a substantial P. gingivalis copy number in the brain at 5 weeks, increasing 10-fold at 10 weeks (Inf. 10 week). All treatment groups showed a significant decrease in P. gingivalis load compared to vehicle-treated Inf. 10 week mice (***P < 0.0001, n = 63). Treatment with the Kgp inhibitor COR271 resulted in a 90% reduction of P. gingivalis copy number. Comparing treatment groups to baseline infection at the beginning of treatment (Inf. 5 week) showed a significant reduction with COR271 and COR286 (##P < 0.01, #P < 0.05) but not with moxifloxacin. (G) The number of Gad67+ interneurons in the dentate gyrus of the hippocampus was significantly decreased in the Inf. 10 week group (*P < 0.05, n = 120). This decrease was reduced in all treatment groups, with COR271 and COR286 trending to better protection than moxifloxacin. (F) Geometric mean with 95% confidence interval. (B), (D), and (G) show the mean with SEM error bars.
Fig. 8. COR388 target engagement and dose-dependent…
Fig. 8. COR388 target engagement and dose-dependent effects on brain P. gingivalis, Aβ1–42, and TNFα in mice.
(A) COR553 fluorescent activity probe for Kgp. (B) COR553 labeling of Kgp in P. gingivalis W83 strain and no labeling in mutant deficient in Kgp (ΔKgp). (C) W83 lysates labeled with COR553. Left lane, before immunodepletion; middle lane, after immunodepletion with anti-Kgp–conjugated beads; right lane, after elution from anti-Kgp–conjugated beads. (D) W83 strain titrated and labeled with COR553 to determine the limit of bacterial detection. See Results for details. (E) Oral plaque samples from human subjects (CB1-5) with periodontal disease were incubated ex vivo with COR553 probe with or without preincubation with COR388. COR553 probe and CAB102 detected Kgp strongly in three subjects (CB1, CB4, and CB5) and weakly in one subject (CB3). COR388 preincubation blocked COR553 probe binding to Kgp. (F) qPCR analysis of plaque samples using hmuY gene–specific primers identified P. gingivalis DNA in samples. (G) qPCR analysis of saliva samples. The bar graphs in (F) and (G) show the means and SEMs of three replicates. (H) COR388 treatment of W83 culture in defined growth medium reduced growth similarly to a Kgp-deficient strain (ΔKgp) over 43 hours. (I) Resistance developed rapidly to moxifloxacin but not COR388 with repeat passaging of bacterial culture. (J to L) Efficacy of COR388 at three oral doses of 3, 10, and 30 mg/kg twice daily in treating an established P. gingivalis brain infection in mice. Reduction of brain tissue levels of P. gingivalis (J), Aβ1–42 (K), and TNFα (L). The bar graphs show the means with SEM error bars. ***P < 0.001, **P < 0.01, *P < 0.05, t test with Dunn’s multiple comparison correction; n = 39.

References

    1. Wyss-Coray T., Rogers J., Inflammation in Alzheimer disease—A brief review of the basic science and clinical literature. Cold Spring Harb. Perspect. Med. 2, a006346 (2012).
    1. Kaushal V., Dye R., Pakavathkumar P., Foveau B., Flores J., Hyman B., Ghetti B., Koller B. H., LeBlanc A. C., Neuronal NLRP1 inflammasome activation of Caspase-1 coordinately regulates inflammatory interleukin-1-beta production and axonal degeneration-associated Caspase-6 activation. Cell Death Differ. 22, 1676–1686 (2015).
    1. Mawanda F., Wallace R., Can infections cause Alzheimer's disease? Epidemiol. Rev. 35, 161–180 (2013).
    1. Kumar D. K. V., Choi S. H., Washicosky K. J., Eimer W. A., Tucker S., Ghofrani J., Lefkowitz A., McColl G., Goldstein L. E., Tanzi R. E., Moir R. D., Amyloid-β peptide protects against microbial infection in mouse and worm models of Alzheimer’s disease. Sci. Transl. Med. 8, 340ra72 (2016).
    1. Soscia S. J., Kirby J. E., Washicosky K. J., Tucker S. M., Ingelsson M., Hyman B., Burton M. A., Goldstein L. E., Duong S., Tanzi R. E., Moir R. D., The Alzheimer’s disease-associated amyloid β-protein is an antimicrobial peptide. PLOS ONE 5, e9505 (2010).
    1. Spitzer P., Condic M., Herrmann M., Oberstein T. J., Scharin-Mehlmann M., Gilbert D. F., Friedrich O., Grömer T., Kornhuber J., Lang R., Maler J. M., Amyloidogenic amyloid-β-peptide variants induce microbial agglutination and exert antimicrobial activity. Sci. Rep. 6, 32228 (2016).
    1. Darveau R. P., Hajishengallis G., Curtis M. A., Porphyromonas gingivalis as a potential community activist for disease. J. Dent. Res. 91, 816–820 (2012).
    1. Kaye E. K., Valencia A., Baba N., Spiro A. III, Dietrich T., Garcia R. I., Tooth loss and periodontal disease predict poor cognitive function in older men. J. Am. Geriatr. Soc. 58, 713–718 (2010).
    1. Gatz M., Mortimer J. A., Fratiglioni L., Johansson B., Berg S., Reynolds C. A., Pedersen N. L., Potentially modifiable risk factors for dementia in identical twins. Alzheimers Dement. 2, 110–117 (2006).
    1. Stein P. S., Desrosiers M., Donegan S. J., Yepes J. F., Kryscio R. J., Tooth loss, dementia and neuropathology in the Nun study. J. Am. Dent. Assoc. 138, 1314–1322; quiz 1381–2 (2007).
    1. Kamer A. R., Pirraglia E., Tsui W., Rusinek H., Vallabhajosula S., Mosconi L., Yi L., McHugh P., Craig R. G., Svetcov S., Linker R., Shi C., Glodzik L., Williams S., Corby P., Saxena D., de Leon M. J., Periodontal disease associates with higher brain amyloid load in normal elderly. Neurobiol. Aging 36, 627–633 (2015).
    1. Noble J. M., Borrell L. N., Papapanou P. N., Elkind M. S. V., Scarmeas N., Wright C. B., Periodontitis is associated with cognitive impairment among older adults: Analysis of NHANES-III. J. Neurol. Neurosurg. Psychiatry 80, 1206–1211 (2009).
    1. Ide M., Harris M., Stevens A., Sussams R., Hopkins V., Culliford D., Fuller J., Ibbett P., Raybould R., Thomas R., Puenter U., Teeling J., Perry V. H., Holmes C., Periodontitis and cognitive decline in Alzheimer’s disease. PLOS ONE 11, e0151081 (2016).
    1. Poole S., Singhrao S. K., Chukkapalli S., Rivera M., Velsko I., Kesavalu L., Crean S., Active invasion of porphyromonas gingivalis and infection-induced complement activation in ApoE−/− mice brains. J. Alzheimers Dis. 43, 67–80 (2015).
    1. Ishida N., Ishihara Y., Ishida K., Tada H., Funaki-Kato Y., Hagiwara M., Ferdous T., Abdullah M., Mitani A., Michikawa M., Matsushita K., Periodontitis induced by bacterial infection exacerbates features of Alzheimer’s disease in transgenic mice. NPJ Aging Mech. Dis. 3, 15 (2017).
    1. Poole S., Singhrao S. K., Kesavalu L., Curtis M. A., Crean S., Determining the presence of periodontopathic virulence factors in short-term postmortem Alzheimer’s disease brain tissue. J. Alzheimers Dis. 36, 665–677 (2013).
    1. Singhrao S. K., Harding A., Poole S., Kesavalu L., Crean S., Porphyromonas gingivalis periodontal infection and its putative links with Alzheimer’s disease. Mediators Inflamm. 2015, 137357 (2015).
    1. Griffen A. L., Becker M. R., Lyons S. R., Moeschberger M. L., Leys E. J., Prevalence of Porphyromonas gingivalis and periodontal health status. J. Clin. Microbiol. 36, 3239–3242 (1998).
    1. Forner L., Larsen T., Kilian M., Holmstrup P., Incidence of bacteremia after chewing, tooth brushing and scaling in individuals with periodontal inflammation. J. Clin. Periodontol. 33, 401–407 (2006).
    1. Mahendra J., Mahendra L., Kurian V. M., Jaishankar K., Mythilli R., Prevalence of periodontal pathogens in coronary atherosclerotic plaque of patients undergoing coronary artery bypass graft surgery. J. Maxillofac. Oral Surg. 8, 108–113 (2009).
    1. Katz J., Chegini N., Shiverick K. T., Lamont R. J., Localization of P. gingivalis in preterm delivery placenta. J. Dent. Res. 88, 575–578 (2009).
    1. Ishikawa M., Yoshida K., Okamura H., Ochiai K., Takamura H., Fujiwara N., Ozaki K., Oral Porphyromonas gingivalis translocates to the liver and regulates hepatic glycogen synthesis through the Akt/GSK-3β signaling pathway. Biochim. Biophys. Acta 1832, 2035–2043 (2013).
    1. Mougeot J.-L. C., Stevens C. B., Paster B. J., Brennan M. T., Lockhart P. B., Mougeot F. K. B., Porphyromonas gingivalis is the most abundant species detected in coronary and femoral arteries. J. Oral Microbiol. 9, 1281562 (2017).
    1. Guo Y., Nguyen K.-A., Potempa J., Dichotomy of gingipains action as virulence factors: From cleaving substrates with the precision of a surgeon’s knife to a meat chopper-like brutal degradation of proteins. Periodontol. 2000 54, 15–44 (2010).
    1. Gui M. J., Dashper S. G., Slakeski N., Chen Y.-Y., Reynolds E. C., Spheres of influence: Porphyromonas gingivalis outer membrane vesicles. Mol. Oral Microbiol. 31, 365–378 (2016).
    1. Grenier D., Roy S., Chandad F., Plamondon P., Yoshioka M., Nakayama K., Mayrand D., Effect of inactivation of the Arg- and/or Lys-gingipain gene on selected virulence and physiological properties of Porphyromonas gingivalis. Infect. Immun. 71, 4742–4748 (2003).
    1. Stathopoulou P. G., Galicia J. C., Benakanakere M. R., Garcia C. A., Potempa J., Kinane D. F., Porphyromonas gingivalis induce apoptosis in human gingival epithelial cells through a gingipain-dependent mechanism. BMC Microbiol. 9, 107 (2009).
    1. Sheets S. M., Potempa J., Travis J., Casiano C. A., Fletcher H. M., Gingipains from Porphyromonas gingivalis W83 induce cell adhesion molecule cleavage and apoptosis in endothelial cells. Infect. Immun. 73, 1543–1552 (2005).
    1. Kinane J. A., Benakanakere M. R., Zhao J., Hosur K. B., Kinane D. F., Porphyromonas gingivalis influences actin degradation within epithelial cells during invasion and apoptosis. Cell. Microbiol. 14, 1085–1096 (2012).
    1. Flemmig T. F., Milián E., Karch H., Klaiber B., Differential clinical treatment outcome after systemic metronidazole and amoxicillin in patients harboring Actinobacillus actinomycetemcomitans and/or Porphyromonas gingivalis. J. Clin. Periodontol. 25, 380–387 (1998).
    1. Travis J., Potempa J., Bacterial proteinases as targets for the development of second-generation antibiotics. Biochim. Biophys. Acta 1477, 35–50 (2000).
    1. Clatworthy A. E., Pierson E., Hung D. T., Targeting virulence: A new paradigm for antimicrobial therapy. Nat. Chem. Biol. 3, 541–548 (2007).
    1. Supuran C. T., Scozzafava A., Mastrolorenzo A., Bacterial proteases: Current therapeutic use and future prospects for the development of new antibiotics. Expert Opin. Ther. Pat. 11, 221–259 (2001).
    1. Kadowaki T., Baba A., Abe N., Takii R., Hashimoto M., Tsukuba T., Okazaki S., Suda Y., Asao T., Yamamoto K., Suppression of pathogenicity of Porphyromonas gingivalis by newly developed gingipain inhibitors. Mol. Pharmacol. 66, 1599–1606 (2004).
    1. Nelson P. T., Alafuzoff I., Bigio E. H., Bouras C., Braak H., Cairns N. J., Castellani R. J., Crain B. J., Davies P., Del Tredici K., Duyckaerts C., Frosch M. P., Haroutunian V., Hof P. R., Hulette C. M., Hyman B. T., Iwatsubo T., Jellinger K. A., Jicha G. A., Kovari E., Kukull W. A., Leverenz J. B., Love S., Mackenzie I. R., Mann D. M., Masliah E., McKee A. C., Montine T. J., Morris J. C., Schneider J. A., Sonnen J. A., Thal D. R., Trojanowski J. Q., Troncoso J. C., Wisniewski T., Woltjer R. L., Beach T. G., Correlation of Alzheimer disease neuropathologic changes with cognitive status: A review of the literature. J. Neuropathol. Exp. Neurol. 71, 362–381 (2012).
    1. Hershko A., Ciechanover A., The ubiquitin system. Annu. Rev. Biochem. 67, 425–479 (1998).
    1. Chu C. T., Caruso J. L., Cummings T. J., Ervin J., Rosenberg C., Hulette C. M., Ubiquitin immunochemistry as a diagnostic aid for community pathologists evaluating patients who have dementia. Mod. Pathol. 13, 420–426 (2000).
    1. Sperling R., Mormino E., Johnson K., The evolution of preclinical Alzheimer’s disease: Implications for prevention trials. Neuron 84, 608–622 (2014).
    1. Potempa J., Nguyen K.-A., Purification and characterization of gingipains. Curr. Protoc. Protein Sci. Chapter 21, Unit 21.20 (2007).
    1. Potempa J., Pike R., Travis J., The multiple forms of trypsin-like activity present in various strains of Porphyromonas gingivalis are due to the presence of either Arg-gingipain or Lys-gingipain. Infect. Immun. 63, 1176–1182 (1995).
    1. Gmiterek A., Wójtowicz H., Mackiewicz P., Radwan-Oczko M., Kantorowicz M., Chomyszyn-Gajewska M., Frąszczak M., Bielecki M., Olczak M., Olczak T., The unique hmuY gene sequence as a specific marker of Porphyromonas gingivalis. PLOS ONE 8, e67719 (2013).
    1. Linz B., Balloux F., Moodley Y., Manica A., Liu H., Roumagnac P., Falush D., Stamer C., Prugnolle F., van der Merwe S. W., Yamaoka Y., Graham D. Y., Perez-Trallero E., Wadstrom T., Suerbaum S., Achtman M., An African origin for the intimate association between humans and Helicobacter pylori. Nature 445, 915–918 (2007).
    1. Schabereiter-Gurtner C., Hirschl A. M., Dragosics B., Hufnagl P., Puz S., Kovách Z., Rotter M., Makristathis A., Novel real-time PCR assay for detection of Helicobacter pylori infection and simultaneous clarithromycin susceptibility testing of stool and biopsy specimens. J. Clin. Microbiol. 42, 4512–4518 (2004).
    1. Spudich S. S., Nilsson A. C., Lollo N. D., Liegler T. J., Petropoulos C. J., Deeks S. G., Paxinos E. E., Price R. W., Cerebrospinal fluid HIV infection and pleocytosis: Relation to systemic infection and antiretroviral treatment. BMC Infect. Dis. 5, 98 (2005).
    1. Yamamoto Y., PCR in diagnosis of infection: Detection of bacteria in cerebrospinal fluids. Clin. Diagn. Lab. Immunol. 9, 508–514 (2002).
    1. Espy M. J., Uhl J. R., Sloan L. M., Buckwalter S. P., Jones M. F., Vetter E. A., Yao J. D. C., Wengenack N. L., Rosenblatt J. E., Cockerill F. R. III, Smith T. F., Real-time PCR in clinical microbiology: Applications for routine laboratory testing. Clin. Microbiol. Rev. 19, 165–256 (2006).
    1. Yin H., Kuret J., C-terminal truncation modulates both nucleation and extension phases of τ fibrillization. FEBS Lett. 580, 211–215 (2006).
    1. Kovacech B., Novak M., Tau truncation is a productive posttranslational modification of neurofibrillary degeneration in Alzheimer’s disease. Curr. Alzheimer Res. 7, 708–716 (2010).
    1. Taniguchi-Watanabe S., Arai T., Kametani F., Nonaka T., Masuda-Suzukake M., Tarutani A., Murayama S., Saito Y., Arima K., Yoshida M., Akiyama H., Robinson A., Mann D. M. A., Iwatsubo T., Hasegawa M., Biochemical classification of tauopathies by immunoblot, protein sequence and mass spectrometric analyses of sarkosyl-insoluble and trypsin-resistant tau. Acta Neuropathol. 131, 267–280 (2016).
    1. Uberti D., Rizzini C., Spano P. F., Memo M., Characterization of tau proteins in human neuroblastoma SH-SY5Y cell line. Neurosci. Lett. 235, 149–153 (1997).
    1. McAvoy T., Lassman M. E., Spellman D. S., Ke Z., Howell B. J., Wong O., Zhu L., Tanen M., Struyk A., Laterza O. F., Quantification of tau in cerebrospinal fluid by immunoaffinity enrichment and tandem mass spectrometry. Clin. Chem. 60, 683–689 (2014).
    1. Sato C., Barthélemy N. R., Mawuenyega K. G., Patterson B. W., Gordon B. A., Jockel-Balsarotti J., Sullivan M., Crisp M. J., Kasten T., Kirmess K. M., Kanaan N. M., Yarasheski K. E., Baker-Nigh A., Benzinger T. L. S., Miller T. M., Karch C. M., Bateman R. J., Tau kinetics in neurons and the human central nervous system. Neuron 97, 1284–1298.e7 (2018).
    1. von Bergen M., Friedhoff P., Biernat J., Heberle J., Mandelkow E.-M., Mandelkow E., Assembly of τ protein into Alzheimer paired helical filaments depends on a local sequence motif (306VQIVYK311) forming β structure. Proc. Natl. Acad. Sci. U.S.A. 97, 5129–5134 (2000).
    1. Stöhr J., Wu H., Nick M., Wu Y., Bhate M., Condello C., Johnson N., Rodgers J., Lemmin T., Acharya S., Becker J., Robinson K., Kelly M. J. S., Gai F., Stubbs G., Prusiner S. B., DeGrado W. F., A 31-residue peptide induces aggregation of tau’s microtubule-binding region in cells. Nat. Chem. 9, 874–881 (2017).
    1. Eick S., Pfister W., Efficacy of antibiotics against periodontopathogenic bacteria within epithelial cells: An in vitro study. J. Periodontol. 75, 1327–1334 (2004).
    1. Portelius E., Zetterberg H., Dean R. A., Marcil A., Bourgeois P., Nutu M., Andreasson U., Siemers E., Mawuenyega K. G., Sigurdson W. C., May P. C., Paul S. M., Holtzman D. M., Blennow K., Bateman R. J., Amyloid-β1–15/16 as a marker for γ-secretase inhibition in Alzheimer’s disease. J. Alzheimers Dis. 31, 335–341 (2012).
    1. Sztukowska M., Sroka A., Bugno M., Banbula A., Takahashi Y., Pike R. N., Genco C. A., Travis J., Potempa J., The C-terminal domains of the gingipain K polyprotein are necessary for assembly of the active enzyme and expression of associated activities. Mol. Microbiol. 54, 1393–1408 (2004).
    1. Nguyen K.-A., Travis J., Potempa J., Does the importance of the C-terminal residues in the maturation of RgpB from Porphyromonas gingivalis reveal a novel mechanism for protein export in a subgroup of Gram-Negative bacteria? J. Bacteriol. 189, 833–843 (2007).
    1. Govindpani K., Calvo-Flores Guzman B., Vinnakota C., Waldvogel H. J., Faull R. L., Kwakowsky A., Towards a better understanding of GABAergic remodeling in Alzheimer’s disease. Int. J. Mol. Sci. 18, E1813 (2017).
    1. Fornicola W., Pelcovits A., Li B.-X., Heath J., Perry G., Castellani R. J., Alzheimer disease pathology in middle age reveals a spatial-temporal disconnect between amyloid-β and phosphorylated tau. Open Neurol. J. 8, 22–26 (2014).
    1. Lenzo J. C., O’Brien-Simpson N. M., Orth R. K., Mitchell H. L., Dashper S. G., Reynolds E. C., Porphyromonas gulae has virulence and immunological characteristics similar to those of the human periodontal pathogen Porphyromonas gingivalis. Infect. Immun. 84, 2575–2585 (2016).
    1. Yamasaki Y., Nomura R., Nakano K., Naka S., Matsumoto-Nakano M., Asai F., Ooshima T., Distribution of periodontopathic bacterial species in dogs and their owners. Arch. Oral Biol. 57, 1183–1188 (2012).
    1. Sun L., Zhou R., Yang G., Shi Y., Analysis of 138 pathogenic mutations in presenilin-1 on the in vitro production of Aβ42 and Aβ40 peptides by γ-secretase. Proc. Natl. Acad. Sci. U.S.A. 114, E476–E485 (2017).
    1. Zhou R., Yang G., Shi Y., Dominant negative effect of the loss-of-function γ-secretase mutants on the wild-type enzyme through heterooligomerization. Proc. Natl. Acad. Sci. U.S.A. 114, 12731–12736 (2017).
    1. Zigman W. B., Devenny D. A., Krinsky-McHale S. J., Jenkins E. C., Urv T. K., Wegiel J., Schupf N., Silverman W., Alzheimer’s disease in adults with Down syndrome. Int. Rev. Res. Ment. Retard. 36, 103–145 (2008).
    1. Cichon P. J., Crawford L. B., Grimm W. D., Early-onset periodontitis associated with Down’s syndrome—Clinical interventional study. Ann. Periodontol. 3, 370–380 (1998).
    1. Amano A., Kishima T., Kimura S., Takiguchi M., Ooshima T., Hamada S., Morisaki I., Periodontopathic bacteria in children with Down syndrome. J. Periodontol. 71, 249–255 (2000).
    1. Ram G., Chinen J., Infections and immunodeficiency in Down syndrome. Clin. Exp. Immunol. 164, 9–16 (2011).
    1. Giacona M. B., Papapanou P. N., Lamster I. B., Rong L. L., D’Agati V. D., Schmidt A. M., Lalla E., Porphyromonas gingivalis induces its uptake by human macrophages and promotes foam cell formation in vitro. FEMS Microbiol. Lett. 241, 95–101 (2004).
    1. Coureuil M., Lécuyer H., Bourdoulous S., Nassif X., A journey into the brain: Insight into how bacterial pathogens cross blood-brain barriers. Nat. Rev. Microbiol. 15, 149–159 (2017).
    1. Talamo B. R., Feng W.-H., Perez-Cruet M., Adelman L., Kosik K., Lee V. M.-Y., Cork L. C., Kauer J. S., Pathologic changes in olfactory neurons in Alzheimer’s disease. Ann. N. Y. Acad. Sci. 640, 1–7 (1991).
    1. Li L., Michel R., Cohen J., DeCarlo A., Kozarov E., Intracellular survival and vascular cell-to-cell transmission of Porphyromonas gingivalis. BMC Microbiol. 8, 26 (2008).
    1. Cope T. E., Rittman T., Borchert R. J., Jones P. S., Vatansever D., Allinson K., Passamonti L., Vazquez Rodriguez P., Bevan-Jones W. R., O’Brien J. T., Rowe J. B., Tau burden and the functional connectome in Alzheimer’s disease and progressive supranuclear palsy. Brain 141, 550–567 (2018).
    1. Urnowey S., Ansai T., Bitko V., Nakayama K., Takehara T., Barik S., Temporal activation of anti- and pro-apoptotic factors in human gingival fibroblasts infected with the periodontal pathogen, Porphyromonas gingivalis: Potential role of bacterial proteases in host signalling. BMC Microbiol. 6, 26 (2006).
    1. Chu J., Lauretti E., Praticò D., Caspase-3-dependent cleavage of Akt modulates tau phosphorylation via GSK3β kinase: Implications for Alzheimer’s disease. Mol. Psychiatry 22, 1002–1008 (2017).
    1. Sandhu P., Naeem M. M., Lu C., Kumarathasan P., Gomes J., Basak A., Ser422 phosphorylation blocks human Tau cleavage by caspase-3: Biochemical implications to Alzheimer’s Disease. Bioorg. Med. Chem. Lett. 27, 642–652 (2017).
    1. Corder E. H., Saunders A. M., Strittmatter W. J., Schmechel D. E., Gaskell P. C., Small G. W., Roses A. D., Haines J. L., Pericak-Vance M. A., Gene dose of apolipoprotein E type 4 allele and the risk of Alzheimer’s disease in late onset families. Science 261, 921–923 (1993).
    1. Roselaar S. E., Daugherty A., Apolipoprotein E-deficient mice have impaired innate immune responses to Listeria monocytogenes in vivo. J. Lipid Res. 39, 1740–1743 (1998).
    1. Lönn J., Ljunggren S., Klarström-Engström K., Demirel I., Bengtsson T., Karlsson H., Lipoprotein modifications by gingipains of Porphyromonas gingivalis. J. Periodontal Res. 53, 403–413 (2018).
    1. Harris F. M., Brecht W. J., Xu Q., Tesseur I., Kekonius L., Wyss-Coray T., Fish J. D., Masliah E., Hopkins P. C., Scearce-Levie K., Weisgraber K. H., Mucke L., Mahley R. W., Huang Y., Carboxyl-terminal-truncated apolipoprotein E4 causes Alzheimer’s disease-like neurodegeneration and behavioral deficits in transgenic mice. Proc. Natl. Acad. Sci. U.S.A. 100, 10966–10971 (2003).
    1. Jay T. R., von Saucken V. E., Landreth G. E., TREM2 in neurodegenerative diseases. Mol. Neurodegener. 12, 56 (2017).
    1. Minoretti P., Gazzaruso C., Vito C. D., Emanuele E., Bianchi M. P., Coen E., Reino M., Geroldi D., Effect of the functional toll-like receptor 4 Asp299Gly polymorphism on susceptibility to late-onset Alzheimer’s disease. Neurosci. Lett. 391, 147–149 (2006).
    1. Brouwers N., Van Cauwenberghe C., Engelborghs S., Lambert J.-C., Bettens K., Le Bastard N., Pasquier F., Montoya A. G., Peeters K., Mattheijssens M., Vandenberghe R., Deyn P. P., Cruts M., Amouyel P., Sleegers K., Van Broeckhoven C., Alzheimer risk associated with a copy number variation in the complement receptor 1 increasing C3b/C4b binding sites. Mol. Psychiatry 17, 223–233 (2012).
    1. Tan M.-S., Yu J.-T., Jiang T., Zhu X.-C., Wang H.-F., Zhang W., Wang Y.-L., Jiang W., Tan L., NLRP3 polymorphisms are associated with late-onset Alzheimer’s disease in Han Chinese. J. Neuroimmunol. 265, 91–95 (2013).
    1. Gao X., Dong Y., Liu Z., Niu B., Silencing of triggering receptor expressed on myeloid cells-2 enhances the inflammatory responses of alveolar macrophages to lipopolysaccharide. Mol. Med. Rep. 7, 921–926 (2013).
    1. N’Diaye E.-N., Branda C. S., Branda S. S., Nevarez L., Colonna M., Lowell C., Hamerman J. A., Seaman W. E., TREM-2 (triggering receptor expressed on myeloid cells 2) is a phagocytic receptor for bacteria. J. Cell Biol. 184, 215–223 (2009).
    1. Replogle J. M., Chan G., White C. C., Raj T., Winn P. A., Evans D. A., Sperling R. A., Chibnik L. B., Bradshaw E. M., Schneider J. A., Bennett D. A., De Jager P. L., A TREM1 variant alters the accumulation of Alzheimer-related amyloid pathology. Ann. Neurol. 77, 469–477 (2015).
    1. Bostanci N., Thurnheer T., Aduse-Opoku J., Curtis M. A., Zinkernagel A. S., Belibasakis G. N., Porphyromonas gingivalis regulates TREM-1 in human polymorphonuclear neutrophils via its gingipains. PLOS ONE 8, e75784 (2013).
    1. Martinon F., Tschopp J., Inflammatory caspases: Linking an intracellular innate immune system to autoinflammatory diseases. Cell 117, 561–574 (2004).
    1. Saresella M., La Rosa F., Piancone F., Zoppis M., Marventano I., Calabrese E., Rainone V., Nemni R., Mancuso R., Clerici M., The NLRP3 and NLRP1 inflammasomes are activated in Alzheimer’s disease. Mol. Neurodegener. 11, 23 (2016).
    1. Olsen I., Yilmaz Ö., Modulation of inflammasome activity by Porphyromonas gingivalis in periodontitis and associated systemic diseases. J. Oral Microbiol. 8, 30385 (2016).
    1. Venegas C., Kumar S., Franklin B. S., Dierkes T., Brinkschulte R., Tejera D., Vieira-Saecker A., Schwartz S., Santarelli F., Kummer M. P., Griep A., Gelpi E., Beilharz M., Riedel D., Golenbock D. T., Geyer M., Walter J., Latz E., Heneka M. T., Microglia-derived ASC specks cross-seed amyloid-β in Alzheimer’s disease. Nature 552, 355–361 (2017).
    1. Huang M. T.-H., Taxman D. J., Holley-Guthrie E. A., Moore C. B., Willingham S. B., Madden V., Parsons R. K., Featherstone G. L., Arnold R. R., O’Connor B. P., Ting J. P.-Y., Critical role of apoptotic speck protein containing a caspase recruitment domain (ASC) and NLRP3 in causing necrosis and ASC speck formation induced by Porphyromonas gingivalis in human cells. J. Immunol. 182, 2395–2404 (2009).
    1. Mariathasan S., Weiss D. S., Dixit V. M., Monack D. M., Innate immunity against Francisella tularensis is dependent on the ASC/caspase-1 axis. J. Exp. Med. 202, 1043–1049 (2005).
    1. Ellis T. N., Kuehn M. J., Virulence and immunomodulatory roles of bacterial outer membrane vesicles. Microbiol. Mol. Biol. Rev. 74, 81–94 (2010).
    1. Cecil J. D., O’Brien-Simpson N. M., Lenzo J. C., Holden J. A., Singleton W., Perez-Gonzalez A., Mansell A., Reynolds E. C., Outer membrane vesicles prime and activate macrophage inflammasomes and cytokine secretion in vitro and in vivo. Front. Immunol. 8, 1017 (2017).
    1. Fleetwood A. J., Lee M. K. S., Singleton W., Achuthan A., Lee M.-C., O’Brien-Simpson N. M., Cook A. D., Murphy A. J., Dashper S. G., Reynolds E. C., Hamilton J. A., Metabolic remodeling, inflammasome activation, and pyroptosis in macrophages stimulated by Porphyromonas gingivalis and its outer membrane vesicles. Front. Cell. Infect. Microbiol. 7, 351 (2017).
    1. Zhao Y., Shao F., Diverse mechanisms for inflammasome sensing of cytosolic bacteria and bacterial virulence. Curr. Opin. Microbiol. 29, 37–42 (2016).
    1. Bender K. O., Garland M., Ferreyra J. A., Hryckowian A. J., Child M. A., Puri A. W., Solow-Cordero D. E., Higginbottom S. K., Segal E., Banaei N., Shen A., Sonnenburg J. L., Bogyo M., A small-molecule antivirulence agent for treating Clostridium difficile infection. Sci. Transl. Med. 7, 306ra148 (2015).
    1. Shi Y., Ratnayake D. B., Okamoto K., Abe N., Yamamoto K., Nakayama K., Genetic analyses of proteolysis, hemoglobin binding, and hemagglutination of Porphyromonas gingivalis. Construction of mutants with a combination of rgpA, rgpB, kgp, and hagA. J. Biol. Chem. 274, 17955–17960 (1999).
    1. Smalley J. W., Birss A. J., Szmigielski B., Potempa J., Sequential action of R- and K-specific gingipains of Porphyromonas gingivalis in the generation of the haem-containing pigment from oxyhaemoglobin. Arch. Biochem. Biophys. 465, 44–49 (2007).
    1. Pathirana R. D., O’Brien-Simpson N. M., Brammar G. C., Slakeski N., Reynolds E. C., Kgp and RgpB, but not RgpA, are important for Porphyromonas gingivalis virulence in the murine periodontitis model. Infect. Immun. 75, 1436–1442 (2007).
    1. Ventola C. L., The antibiotic resistance crisis: Part 1: Causes and threats. P. T. 40, 277–283 (2015).
    1. Kwon J. H., Olsen M. A., Dubberke E. R., The morbidity, mortality, and costs associated with Clostridium difficile infection. Infect. Dis. Clin. North Am. 29, 123–134 (2015).
    1. Narayan P. J., Kim S.-L., Lill C., Feng S., Faull R. L. M., Curtis M. A., Dragunow M., Assessing fibrinogen extravasation into Alzheimer’s disease brain using high-content screening of brain tissue microarrays. J. Neurosci. Methods 247, 41–49 (2015).
    1. Kolb H. C., Finn M. G., Sharpless K. B., Click chemistry: Diverse chemical function from a few good reactions. Angew. Chem. Int. Ed. 40, 2004–2021 (2001).
    1. Poirier J. L., Čapek R., De Koninck Y., Differential progression of Dark Neuron and Fluoro-Jade labelling in the rat hippocampus following pilocarpine-induced status epilepticus. Neuroscience 97, 59–68 (2000).
    1. Morillo J. M., Lau L., Sanz M., Herrera D., Silva A., Quantitative real-time PCR based on single copy gene sequence for detection of Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis. J. Periodontal Res. 38, 518–524 (2003).

Source: PubMed

Подписаться