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Chuang WC, Yang CN, Wang HW, Lin SK, Yu CC, Syu JH, Chiang CP, Shiao YJ, Chen YW. The mechanisms of Porphyromonas gingivalis-derived outer membrane vesicles-induced neurotoxicity and microglia activation. J Dent Sci 2024; 19:1434-1442. [PMID: 39035337 PMCID: PMC11259672 DOI: 10.1016/j.jds.2024.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Indexed: 07/23/2024] Open
Abstract
Background/purpose Periodontitis is associated with various systemic diseases, potentially facilitated by the passage of Porphyromonas gingivalis outer membrane vesicles (Pg-OMVs). Several recent studies have suggested a connection between Pg-OMVs and neuroinflammation and neurodegeneration, but the precise causal relationship remains unclear. This study aimed to investigate the mechanisms underlying these associations using in vitro models. Materials and methods Isolated Pg-OMVs were characterized by morphology, size, and gingipain activity. We exposed SH-SY5Y neuroblastoma cells and BV-2 microglial cells to various concentrations of Pg-OMVs. Cell morphology, a 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, an enzyme-linked immunosorbent assay, and Western blot analysis were used to evaluate the cellular mechanism underlying Pg-OMV-induced neurotoxicity in neuronal cells and inflammatory responses in microglial cells. Results Exposure to Pg-OMVs induced neurotoxicity in SH-SY5Y cells, as evidenced by cellular shrinkage, reduced viability, activation of apoptotic pathways, and diminished neuronal differentiation markers. Gingipain inhibition mitigated these effects, suggesting that gingipain mediates Pg-OMVs-induced neurotoxicity in SH-SY5Y cells. Our research on neuroinflammation suggests that upon endocytosis of Pg-OMVs by BV-2 cells, lipopolysaccharide (LPS) can modulate the production of inducible nitric oxide synthase and tumor necrosis factor-alpha by activating pathways that involve phosphorylated AKT and the phosphorylated JNK pathway. Conclusion Our study demonstrated that following the endocytosis of Pg-OMVs, gingipain can induce neurotoxicity in SH-SY5Y cells. Furthermore, the Pg-OMVs-associated LPS can trigger neuroinflammation via AKT and JNK signaling pathways in BV-2 cells.
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Affiliation(s)
- Wei-Chun Chuang
- Department of Dentistry, Fu Jen Catholic University Hospital, New Taipei City, Taiwan
| | - Cheng-Ning Yang
- Department of Dentistry, School of Dentistry, National Taiwan University, Taipei, Taiwan
| | - Han-Wei Wang
- Department of Dentistry, National Taiwan University Hospital, Taipei, Taiwan
| | - Sze-Kwan Lin
- Department of Dentistry, School of Dentistry, National Taiwan University, Taipei, Taiwan
- Department of Dentistry, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Ching-Chu Yu
- Graduate Institute of Oral Biology, School of Dentistry, National Taiwan University, Taipei, Taiwan
| | - Jhe-Hao Syu
- Graduate Institute of Oral Biology, School of Dentistry, National Taiwan University, Taipei, Taiwan
| | - Chun-Pin Chiang
- Department of Dentistry, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan
- Graduate Institute of Oral Biology, School of Dentistry, National Taiwan University, Taipei, Taiwan
- Graduate Institute of Clinical Dentistry, School of Dentistry, National Taiwan University, Taipei, Taiwan
- Department of Dentistry, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan
| | - Young-Ji Shiao
- National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei, Taiwan
| | - Yi-Wen Chen
- Department of Dentistry, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan
- Graduate Institute of Clinical Dentistry, School of Dentistry, National Taiwan University, Taipei, Taiwan
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Xie S, Iberi V, Boissy Y, Tansky CS, Huggins T, Ramji N, Biesbrock AR. Stannous fluoride forms aggregates between outer and inner membranes leading to membrane rupture of Porphyromonas gingivalis and Prevotella pallens. FRONTIERS IN ORAL HEALTH 2024; 5:1427008. [PMID: 38989256 PMCID: PMC11233731 DOI: 10.3389/froh.2024.1427008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Accepted: 06/07/2024] [Indexed: 07/12/2024] Open
Abstract
Objective Stannous has been shown to bind to free lipopolysaccharides, thus preventing them from binding to TLR receptors. This study was undertaken to determine the histomorphological mechanism of stannous binding to anaerobic bacteria. Methods Two bacteria associated with gingivitis and advanced periodontal disease, Porphyromonas gingivalis (P. gingivalis) and Prevotella pallens (P. pallens), were cultured in 25-1,000 μM of stannous fluoride and stannous chloride for 48 h. The growth rate was estimated using absorbance OD600. Bacterial cells were then fixed and processed for transmission electron microscopy (TEM) analysis. Results Stannous fluoride inhibited proliferation of both P. gingivalis and P. pallens in a dose-dependent manner. There was a statistically significant suppression of the growth curve starting at 100 μM for P. pallens (P = 0.050) and 200 μM for P. gingivalis (P = 0.039). TEM analysis revealed a thick layer of polysaccharides (19.8 nm) in P. gingivalis. The outer and inner membranes were clearly visible with low electron densities in both bacteria. Stannous diffused into bacterial membranes and formed precipitates in the areas spanning outer and inner membranes and below inner membranes. Precipitates varied in size ranging from 46.4 to 84.5 nm in length, and 18.4 to 35.9 nm in width. The membranes were disintegrated in the region where stannous formed precipitates. Cytosolic contents were leaked out, and in several cases, small vesicles were formed. Stannous precipitates were more abundant in numbers and larger in size in bacteria treated with high concentrations (100-300 μM) than in low concentrations (25-50 μM) of stannous fluoride. Furthermore, most of the bacteria were disintegrated in the groups treated with 100-300 μM stannous fluoride. At low concentrations (25 μM), stannous fluoride formed complexes primarily around outer membranes, to which lipopolysaccharides are anchored. Stannous chloride results showed similar trends, but it was less potent than stannous fluoride. Conclusion Stannous fluoride can penetrate bacteria, bind to the constituents of the membrane and form precipitates between outer and inner membranes and beneath inner membranes. These large precipitates damaged the integrity of membranes and allowed cytosolic contents to be leaked out. Stannous complexes formed at the outer membranes, even at low concentrations (25 μM).
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Affiliation(s)
- Sancai Xie
- Discovery & Innovation Platforms, The Procter & Gamble Company, Mason, OH, United States
| | - Vighter Iberi
- Discovery & Innovation Platforms, The Procter & Gamble Company, Mason, OH, United States
| | - Ying Boissy
- Discovery & Innovation Platforms, The Procter & Gamble Company, Mason, OH, United States
| | - Cheryl S Tansky
- Discovery & Innovation Platforms, The Procter & Gamble Company, Mason, OH, United States
| | - Tom Huggins
- Discovery & Innovation Platforms, The Procter & Gamble Company, Mason, OH, United States
| | - Niranjan Ramji
- Global Oral Care R&D, The Procter & Gamble Company, Mason, OH, United States
| | - Aaron R Biesbrock
- Global Oral Care R&D, The Procter & Gamble Company, Mason, OH, United States
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Wang SY, Cai Y, Hu X, Li F, Qian XH, Xia LY, Gao B, Wu L, Xie WZ, Gu JM, Deng T, Zhu C, Jia HC, Peng WQ, Huang J, Fang C, Zeng XT. P. gingivalis in oral-prostate axis exacerbates benign prostatic hyperplasia via IL-6/IL-6R pathway. Mil Med Res 2024; 11:30. [PMID: 38764065 PMCID: PMC11103868 DOI: 10.1186/s40779-024-00533-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 04/30/2024] [Indexed: 05/21/2024] Open
Abstract
BACKGROUND Benign prostatic hyperplasia (BPH) is the most common disease in elderly men. There is increasing evidence that periodontitis increases the risk of BPH, but the specific mechanism remains unclear. This study aimed to explore the role and mechanism of the key periodontal pathogen Porphyromonas gingivalis (P. gingivalis) in the development of BPH. METHODS The subgingival plaque (Sp) and prostatic fluid (Pf) of patients with BPH concurrent periodontitis were extracted and cultured for 16S rDNA sequencing. Ligature-induced periodontitis, testosterone-induced BPH and the composite models in rats were established. The P. gingivalis and its toxic factor P. gingivalis lipopolysaccharide (P.g-LPS) were injected into the ventral lobe of prostate in rats to simulate its colonization of prostate. P.g-LPS was used to construct the prostate cell infection model for mechanism exploration. RESULTS P. gingivalis, Streptococcus oralis, Capnocytophaga ochracea and other oral pathogens were simultaneously detected in the Pf and Sp of patients with BPH concurrent periodontitis, and the average relative abundance of P. gingivalis was found to be the highest. P. gingivalis was detected in both Pf and Sp in 62.5% of patients. Simultaneous periodontitis and BPH synergistically aggravated prostate histological changes. P. gingivalis and P.g-LPS infection could induce obvious hyperplasia of the prostate epithelium and stroma (epithelial thickness was 2.97- and 3.08-fold that of control group, respectively), and increase of collagen fibrosis (3.81- and 5.02-fold that of control group, respectively). P. gingivalis infection promoted prostate cell proliferation, inhibited apoptosis, and upregulated the expression of inflammatory cytokines interleukin-6 (IL-6; 4.47-fold), interleukin-6 receptor-α (IL-6Rα; 5.74-fold) and glycoprotein 130 (gp130; 4.47-fold) in prostatic tissue. P.g-LPS could significantly inhibit cell apoptosis, promote mitosis and proliferation of cells. P.g-LPS activates the Akt pathway through IL-6/IL-6Rα/gp130 complex, which destroys the imbalance between proliferation and apoptosis of prostate cells, induces BPH. CONCLUSION P. gingivalis was abundant in the Pf of patients with BPH concurrent periodontitis. P. gingivalis infection can promote BPH, which may affect the progression of BPH via inflammation and the Akt signaling pathway.
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Affiliation(s)
- Shuang-Ying Wang
- Center for Evidence-Based and Translational Medicine, Zhongnan Hospital of Wuhan University, Wuhan, 430071, China
| | - Yi Cai
- Center for Evidence-Based and Translational Medicine, Zhongnan Hospital of Wuhan University, Wuhan, 430071, China
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, 430071, China
| | - Xiao Hu
- Center for Evidence-Based and Translational Medicine, Zhongnan Hospital of Wuhan University, Wuhan, 430071, China
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, 430071, China
| | - Fei Li
- Center for Evidence-Based and Translational Medicine, Zhongnan Hospital of Wuhan University, Wuhan, 430071, China
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, 430071, China
| | - Xin-Hang Qian
- Center for Evidence-Based and Translational Medicine, Zhongnan Hospital of Wuhan University, Wuhan, 430071, China
- Department of Urology, Huaihe Hospital of Henan University, Kaifeng, 475000, Henan, China
| | - Ling-Yun Xia
- Department of Stomatology, Taihe Hospital, Hubei University of Medicine, Shiyan, 442000, Hubei, China
| | - Bo Gao
- Department of Laboratory Medicine, Taihe Hospital, Hubei University of Medicine, Shiyan, 442000, Hubei, China
| | - Lan Wu
- Department of Stomatology, Zhongnan Hospital of Wuhan University, Wuhan, 430071, China
| | - Wen-Zhong Xie
- Henan Provincial Engineering Research Center for Microecological Regulatory of Oral Environment and Oral Implantology, Kaifeng University Health Science Center, Kaifeng, 475000, Henan, China
| | - Jia-Min Gu
- Center for Evidence-Based and Translational Medicine, Zhongnan Hospital of Wuhan University, Wuhan, 430071, China
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, 430071, China
| | - Tong Deng
- Center for Evidence-Based and Translational Medicine, Zhongnan Hospital of Wuhan University, Wuhan, 430071, China
| | - Cong Zhu
- Center for Evidence-Based and Translational Medicine, Zhongnan Hospital of Wuhan University, Wuhan, 430071, China
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, 430071, China
| | - Hai-Chang Jia
- Center for Evidence-Based and Translational Medicine, Zhongnan Hospital of Wuhan University, Wuhan, 430071, China
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, 430071, China
| | - Wan-Qi Peng
- Department of Stomatology, Zhongnan Hospital of Wuhan University, Wuhan, 430071, China
- School of Stomatology, Jinan University, Guangzhou, 510632, China
| | - Jiao Huang
- Center for Evidence-Based and Translational Medicine, Zhongnan Hospital of Wuhan University, Wuhan, 430071, China.
| | - Cheng Fang
- Center for Evidence-Based and Translational Medicine, Zhongnan Hospital of Wuhan University, Wuhan, 430071, China.
| | - Xian-Tao Zeng
- Center for Evidence-Based and Translational Medicine, Zhongnan Hospital of Wuhan University, Wuhan, 430071, China.
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, 430071, China.
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Zhang Y, Jia Z, Wang J, Liang H. Research Hotspots and Frontiers of Alzheimer's Disease and Gut Microbiota: A Knowledge Mapping and Text Mining Analysis. Mol Neurobiol 2024:10.1007/s12035-024-04168-7. [PMID: 38632152 DOI: 10.1007/s12035-024-04168-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Accepted: 04/03/2024] [Indexed: 04/19/2024]
Abstract
Gut microbiota has been confirmed to be closely related to Alzheimer's disease (AD). Research on gut microbiota and AD has also increased significantly. This study aimed to conduct a bibliometric and visual analysis of published studies related to gut microbiota and AD. Based on the Web of Science Core Collection SCI-Expanded database, we utilize Excel 2019 and visualization analysis tools VOSviewer, Co-Occurrence13.2 (COOC13.2), Citespace, HistCite, and Bibliometrix (R-Tool of R-Studio) for analysis. A total of 1093 related kinds of literature were included, and the number of papers presented an overall increasing trend. The country/region with the most publications is China, the institution is Zhejiang University, the author is Walter J Lukiw from the USA, and the journal is the Journal of Alzheimer's Disease. Hotspot research areas include the relationship between gut microbiota metabolism and AD, AD treatments related to the gut microbiota, and diseases related to AD and gut microbiota. The future research direction may be T cells, NLRP3 inflammasome, and Porphyromonas gingivalis. Studies on AD and gut microbiota have grown rapidly in recent years. Our research results may provide valuable references for readers and help researchers better find new research directions in the future.
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Affiliation(s)
- Youao Zhang
- Department of Urology, People's Hospital of Longhua, No.38 Jinglong Jianshe Road, 518109, Shenzhen, China
- The First School of Clinical Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Zixuan Jia
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, China
| | - Jieyan Wang
- Department of Urology, People's Hospital of Longhua, No.38 Jinglong Jianshe Road, 518109, Shenzhen, China.
| | - Hui Liang
- Department of Urology, People's Hospital of Longhua, No.38 Jinglong Jianshe Road, 518109, Shenzhen, China.
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Shen H, Jiang Y, Qiu C, Xie X, Zhang H, He Z, Song Z, Zhou W. Abnormal amyloid precursor protein processing in periodontal tissue in a murine model of periodontitis induced by Porphyromonas gingivalis. J Periodontal Res 2024; 59:395-407. [PMID: 38311599 DOI: 10.1111/jre.13224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 11/27/2023] [Accepted: 12/05/2023] [Indexed: 02/06/2024]
Abstract
OBJECTIVE The study aimed to investigate the change of amyloid precursor protein (APP) processing and amyloid β (Aβ) metabolites in linking periodontitis to Alzheimer's disease (AD). BACKGROUND Aβ is one of the main pathological features of AD, and few studies have discussed changes in its expression in peripheral tissues or analyzed the relationship between the peripheral imbalance of Aβ production and clearance. METHODS A murine model of periodontitis was established by oral infection with Porphyromonas gingivalis (P. gingivalis). Micro-computed tomography (Micro-CT) was used to observe the destruction of the alveolar bone. Nested quantitative polymerase chain reaction (qPCR) was used to measure small quantities of P.gingivalis DNA in different tissues. Behavioral experiments were performed to measure cognitive function in the mice. The mRNA levels of TNF-α, IL-6, IL-8, RANKL, OPG, APP695, APP751, APP770, and BACE1 in the gingival tissues or cortex were detected by RT-PCR. The levels of Aβ1-40 and Aβ1-42 in gingival crevicular fluid (GCF) and plasma were tested by ELISA. RESULTS P. gingivalis oral infection was found to cause alveolar bone resorption and impaired learning and memory. P.gingivalis DNA was detected in the gingiva, blood and cortex of the P.gingivalis group by nested qPCR (p < .05). The mRNA expression of TNF-α, IL-6, IL-8, RANKL/OPG, and BACE1 in the gingival tissue was significantly higher than that in the control group (p < .05). Similarly, upregulated mRNA levels of APP695 and APP770 were observed in the gingival tissuses and cortex of the P. gingivalis group (p < .05). The levels of Aβ1-40 and Aβ1-42 in the GCF and plasma of the P. gingivalis group were significantly higher than those in the control group (p < .05). CONCLUSION P. gingivalis can directly invade the brain via hematogenous infection. The invasion of P. gingivalis could trigger an immune response and lead to an imbalance between Aβ production and clearance in peripheral tissues, which may trigger an abnormal Aβ metabolite in the brain, resulting in the occurrence and development of AD.
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Affiliation(s)
- Hui Shen
- Department of Periodontology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, China
- National Center for Stomatology, National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology, Shanghai, China
| | - Yiting Jiang
- Department of Periodontology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, China
- National Center for Stomatology, National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology, Shanghai, China
| | - Che Qiu
- Department of Periodontology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, China
- National Center for Stomatology, National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology, Shanghai, China
| | - Xinyi Xie
- Department of Periodontology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, China
- National Center for Stomatology, National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology, Shanghai, China
| | - Huanyu Zhang
- Department of Periodontology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, China
- National Center for Stomatology, National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology, Shanghai, China
| | - Zhiyan He
- National Center for Stomatology, National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology, Shanghai, China
- Laboratory of Oral Microbiota and Systemic Diseases, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, China
| | - Zhongchen Song
- Department of Periodontology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, China
- National Center for Stomatology, National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology, Shanghai, China
| | - Wei Zhou
- National Center for Stomatology, National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology, Shanghai, China
- Laboratory of Oral Microbiota and Systemic Diseases, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, China
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Cichońska D, Mazuś M, Kusiak A. Recent Aspects of Periodontitis and Alzheimer's Disease-A Narrative Review. Int J Mol Sci 2024; 25:2612. [PMID: 38473858 DOI: 10.3390/ijms25052612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 02/13/2024] [Accepted: 02/21/2024] [Indexed: 03/14/2024] Open
Abstract
Periodontitis is an inflammatory condition affecting the supporting structures of the teeth. Periodontal conditions may increase the susceptibility of individuals to various systemic illnesses, including Alzheimer's disease. Alzheimer's disease is a neurodegenerative condition characterized by a gradual onset and progressive deterioration, making it the primary cause of dementia, although the exact cause of the disease remains elusive. Both Alzheimer's disease and periodontitis share risk factors and clinical studies comparing the associations and occurrence of periodontitis among individuals with Alzheimer's disease have suggested a potential correlation between these conditions. Brains of individuals with Alzheimer's disease have substantiated the existence of microorganisms related to periodontitis, especially Porphyromonas gingivalis, which produces neurotoxic gingipains and may present the capability to breach the blood-brain barrier. Treponema denticola may induce tau hyperphosphorylation and lead to neuronal apoptosis. Lipopolysaccharides-components of bacterial cell membranes and mediators of inflammation-also have an impact on brain function. Further research could unveil therapeutic approaches targeting periodontal pathogens to potentially alleviate AD progression.
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Affiliation(s)
- Dominika Cichońska
- Department of Periodontology and Oral Mucosa Diseases, Medical University of Gdańsk, Orzeszkowej 18 St. 18, 80-208 Gdańsk, Poland
| | - Magda Mazuś
- Student Research Group of the Department of Periodontology and Oral Mucosa Diseases, Medical University of Gdańsk, Orzeszkowej 18 St. 18, 80-208 Gdańsk, Poland
| | - Aida Kusiak
- Department of Periodontology and Oral Mucosa Diseases, Medical University of Gdańsk, Orzeszkowej 18 St. 18, 80-208 Gdańsk, Poland
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Ma X, Shin YJ, Yoo JW, Park HS, Kim DH. Extracellular vesicles derived from Porphyromonas gingivalis induce trigeminal nerve-mediated cognitive impairment. J Adv Res 2023; 54:293-303. [PMID: 36796586 DOI: 10.1016/j.jare.2023.02.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 02/09/2023] [Accepted: 02/10/2023] [Indexed: 02/17/2023] Open
Abstract
INTRODUCTION Porphyromonas gingivalis (PG)-infected periodontitis is in close connection with the development of Alzheimer's disease (AD). PG-derived extracellular vesicles (pEVs) contain inflammation-inducing virulence factors, including gingipains (GPs) and lipopolysaccharide (LPS). OBJECTIVES To understand how PG could cause cognitive decline, we investigated the effects of PG and pEVs on the etiology of periodontitis and cognitive impairment in mice. METHODS Cognitive behaviors were measured in the Y-maze and novel object recognition tasks. Biomarkers were measured using ELISA, qPCR, immunofluorescence assay, and pyrosequencing. RESULTS pEVs contained neurotoxic GPs and inflammation-inducible fimbria protein and LPS. Gingivally exposed, but not orally gavaged, PG or pEVs caused periodontitis and induced memory impairment-like behaviors. Gingival exposure to PG or pEVs increased TNF-α expression in the periodontal and hippocampus tissues. They also increased hippocampal GP+Iba1+, LPS+Iba1+, and NF-κB+Iba1+ cell numbers. Gingivally exposed PG or pEVs decreased BDNF, claudin-5, and N-methyl-D-aspartate receptor expression and BDNF+NeuN+ cell number. Gingivally exposed fluorescein-5-isothiocyanate-labeled pEVs (F-pEVs) were detected in the trigeminal ganglia and hippocampus. However, right trigeminal neurectomy inhibited the translocation of gingivally injected F-EVs into the right trigeminal ganglia. Gingivally exposed PG or pEVs increased blood LPS and TNF-α levels. Furthermore, they caused colitis and gut dysbiosis. CONCLUSION Gingivally infected PG, particularly pEVs, may cause cognitive decline with periodontitis. PG products pEVs and LPS may be translocated into the brain through the trigeminal nerve and periodontal blood pathways, respectively, resulting in the cognitive decline, which may cause colitis and gut dysbiosis. Therefore, pEVs may be a remarkable risk factor for dementia.
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Affiliation(s)
- Xiaoyang Ma
- Neurobiota Research Center, College of Pharmacy, Kyung Hee University, 26, Kyungheedae-ro, Dong-daemun-gu, Seoul 02447, Korea.
| | - Yoon-Jung Shin
- Neurobiota Research Center, College of Pharmacy, Kyung Hee University, 26, Kyungheedae-ro, Dong-daemun-gu, Seoul 02447, Korea.
| | - Jong-Wook Yoo
- Neurobiota Research Center, College of Pharmacy, Kyung Hee University, 26, Kyungheedae-ro, Dong-daemun-gu, Seoul 02447, Korea.
| | - Hee-Seo Park
- Neurobiota Research Center, College of Pharmacy, Kyung Hee University, 26, Kyungheedae-ro, Dong-daemun-gu, Seoul 02447, Korea.
| | - Dong-Hyun Kim
- Neurobiota Research Center, College of Pharmacy, Kyung Hee University, 26, Kyungheedae-ro, Dong-daemun-gu, Seoul 02447, Korea.
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Jin J, Guang M, Li S, Liu Y, Zhang L, Zhang B, Cheng M, Schmalz G, Huang X. Immune-related signature of periodontitis and Alzheimer's disease linkage. Front Genet 2023; 14:1230245. [PMID: 37849501 PMCID: PMC10577303 DOI: 10.3389/fgene.2023.1230245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 09/22/2023] [Indexed: 10/19/2023] Open
Abstract
Background: Periodontits (PD) and Alzheimer's disease (AD) are both associated with ageing and clinical studies increasingly evidence their association. However, specific mechanisms underlying this association remain undeciphered, and immune-related processes are purported to play a signifcant role. The accrual of publicly available transcriptomic datasets permits secondary analysis and the application of data-mining and bioinformatic tools for biological discovery. Aim: The present study aimed to leverage publicly available transcriptomic datasets and databases, and apply a series of bioinformatic analysis to identify a robust signature of immune-related signature of PD and AD linkage. Methods: We downloaded gene-expresssion data pertaining PD and AD and identified crosstalk genes. We constructed a protein-protein network analysis, applied immune cell enrichment analysis, and predicted crosstalk immune-related genes and infiltrating immune cells. Next, we applied consisent cluster analysis and performed immune cell bias analysis, followed by LASSO regression to select biomarker immune-related genes. Results: The results showed a 3 gene set comprising of DUSP14, F13A1 and SELE as a robust immune-related signature. Macrophages M2 and NKT, B-cells, CD4+ memory T-cells and CD8+ naive T-cells emerged as key immune cells linking PD with AD. Conclusion: Candidate immune-related biomarker genes and immune cells central to the assocation of PD with AD were identified, and merit investigation in experimental and clinical research.
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Affiliation(s)
- Jieqi Jin
- Department of Stomatology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Mengkai Guang
- Department of Stomatology, China-Japan Friendship Hospital, Beijing, China
| | - Simin Li
- Stomatological Hospital, Southern Medical University, Guangzhou, China
| | - Yong Liu
- Department of Stomatology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Liwei Zhang
- Department of Stomatology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Bo Zhang
- Department of Stomatology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Menglin Cheng
- Department of Stomatology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Gerhard Schmalz
- Department of Cariology, Endodontology and Periodontology, Leipzig University, Leipzig, Germany
| | - Xiaofeng Huang
- Department of Stomatology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
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Chatanaka MK, Sohaei D, Diamandis EP, Prassas I. Beyond the amyloid hypothesis: how current research implicates autoimmunity in Alzheimer's disease pathogenesis. Crit Rev Clin Lab Sci 2023; 60:398-426. [PMID: 36941789 DOI: 10.1080/10408363.2023.2187342] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 03/01/2023] [Indexed: 03/23/2023]
Abstract
The amyloid hypothesis has so far been at the forefront of explaining the pathogenesis of Alzheimer's Disease (AD), a progressive neurodegenerative disorder that leads to cognitive decline and eventual death. Recent evidence, however, points to additional factors that contribute to the pathogenesis of this disease. These include the neurovascular hypothesis, the mitochondrial cascade hypothesis, the inflammatory hypothesis, the prion hypothesis, the mutational accumulation hypothesis, and the autoimmunity hypothesis. The purpose of this review was to briefly discuss the factors that are associated with autoimmunity in humans, including sex, the gut and lung microbiomes, age, genetics, and environmental factors. Subsequently, it was to examine the rise of autoimmune phenomena in AD, which can be instigated by a blood-brain barrier breakdown, pathogen infections, and dysfunction of the glymphatic system. Lastly, it was to discuss the various ways by which immune system dysregulation leads to AD, immunomodulating therapies, and future directions in the field of autoimmunity and neurodegeneration. A comprehensive account of the recent research done in the field was extracted from PubMed on 31 January 2022, with the keywords "Alzheimer's disease" and "autoantibodies" for the first search input, and "Alzheimer's disease" with "IgG" for the second. From the first search, 19 papers were selected, because they contained recent research on the autoantibodies found in the biofluids of patients with AD. From the second search, four papers were selected. The analysis of the literature has led to support the autoimmune hypothesis in AD. Autoantibodies were found in biofluids (serum/plasma, cerebrospinal fluid) of patients with AD with multiple methods, including ELISA, Mass Spectrometry, and microarray analysis. Through continuous research, the understanding of the synergistic effects of the various components that lead to AD will pave the way for better therapeutic methods and a deeper understanding of the disease.
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Affiliation(s)
- Miyo K Chatanaka
- Department of Laboratory and Medicine Pathobiology, University of Toronto, Toronto, Canada
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada
| | - Dorsa Sohaei
- Faculty of Medicine and Health Sciences, McGill University, Montreal, Canada
| | - Eleftherios P Diamandis
- Department of Laboratory and Medicine Pathobiology, University of Toronto, Toronto, Canada
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada
- Department of Clinical Biochemistry, University Health Network, Toronto, Canada
| | - Ioannis Prassas
- Laboratory Medicine Program, University Health Network, Toronto, Canada
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10
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Cheng X, Chi L, Lin T, Liang F, Pei Z, Sun J, Teng W. Exogenous monocyte myeloid-derived suppressor cells ameliorate immune imbalance, neuroinflammation and cognitive impairment in 5xFAD mice infected with Porphyromonas gingivalis. J Neuroinflammation 2023; 20:55. [PMID: 36864466 PMCID: PMC9979576 DOI: 10.1186/s12974-023-02743-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Accepted: 02/21/2023] [Indexed: 03/04/2023] Open
Abstract
BACKGROUND Periodontitis is closely associated with the pathogenesis of Alzheimer's disease (AD). Porphyromonas gingivalis (Pg), the keystone periodontal pathogen, has been reported in our recent study to cause immune-overreaction and induce cognitive impairment. Monocytic myeloid-derived suppressor cells (mMDSCs) possess potent immunosuppressive function. It is unclear whether mMDSCs-mediated immune homeostasis is impaired in AD patients with periodontitis, and whether exogenous mMDSCs could ameliorate immune-overreaction and cognitive impairment induced by Pg. METHODS To explore the influence of Pg on cognitive function, neuropathology and immune balance in vivo, 5xFAD mice were treated with live Pg by oral gavage, three times a week for 1 month. The cells of peripheral blood, spleen and bone marrow from 5xFAD mice were treated with Pg to detect the proportional and functional alterations of mMDSCs in vitro. Next, exogenous mMDSCs were sorted from wild-type healthy mice and intravenously injected into 5xFAD mice that were infected with Pg. We used behavioral tests, flow cytometry and immunofluorescent staining to evaluate whether exogenous mMDSCs could ameliorate the cognitive function, immune homeostasis and reduce neuropathology exacerbated by Pg infection. RESULTS Pg exacerbated cognitive impairment in 5xFAD mice, with the deposition of amyloid plaque and increased number of microglia in the hippocampus and cortex region. The proportion of mMDSCs decreased in Pg-treated mice. In addition, Pg reduced the proportion and the immunosuppressive function of mMDSCs in vitro. Supplement of exogenous mMDSCs improved the cognitive function, and enhanced the proportions of mMDSCs and IL-10+ T cells of 5xFAD mice infected with Pg. At the same time, supplement of exogenous mMDSCs increased the immunosuppressive function of endogenous mMDSCs while decreased the proportions of IL-6+ T cells and IFN-γ+ CD4+ T cells. In addition, the deposition of amyloid plaque decreased while the number of neurons increased in the hippocampus and cortex region after the supplement of exogenous mMDSCs. Furthermore, the number of microglia increased with an increase in the proportion of M2 phenotype. CONCLUSIONS Pg can reduce the proportion of mMDSCs, induce immune-overreaction, and exacerbate the neuroinflammation and cognitive impairment in 5xFAD mice. Supplement of exogenous mMDSCs can reduce the neuroinflammation, immune imbalance and cognitive impairment in 5xFAD mice infected with Pg. These findings indicate the mechanism of AD pathogenesis and Pg-mediated promotion of AD, and provide a potential therapeutic strategy for AD patients.
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Affiliation(s)
- Xiao Cheng
- grid.12981.330000 0001 2360 039XHospital of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Institute of Stomatology, Guanghua School of Stomatology, Sun Yat-Sen University, Guangzhou, China
| | - Li Chi
- grid.12981.330000 0001 2360 039XHospital of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Institute of Stomatology, Guanghua School of Stomatology, Sun Yat-Sen University, Guangzhou, China
| | - Tianqiong Lin
- grid.410560.60000 0004 1760 3078Dongguan Key Laboratory of Chronic Inflammatory Diseases, The First Dongguan Affiliated Hospital, Guangdong Medical University, Dongguan, China
| | - Fengyin Liang
- grid.12981.330000 0001 2360 039XDepartment of Neurology, The First Affiliated Hospital, Sun Yat-Sen University; Guangdong Provincial Key Laboratory of Diagnosis and Treatment of Major Neurological Diseases; National Key Clinical Department and Key Discipline of Neurology, No.58 Zhongshan Road2, Guangzhou, 510080 China
| | - Zhong Pei
- grid.12981.330000 0001 2360 039XDepartment of Neurology, The First Affiliated Hospital, Sun Yat-Sen University; Guangdong Provincial Key Laboratory of Diagnosis and Treatment of Major Neurological Diseases; National Key Clinical Department and Key Discipline of Neurology, No.58 Zhongshan Road2, Guangzhou, 510080 China
| | - Jianbo Sun
- Dongguan Key Laboratory of Chronic Inflammatory Diseases, The First Dongguan Affiliated Hospital, Guangdong Medical University, Dongguan, China.
| | - Wei Teng
- Hospital of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Institute of Stomatology, Guanghua School of Stomatology, Sun Yat-Sen University, Guangzhou, China.
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11
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Alleviation of Porphyromonas gingivalis or Its Extracellular Vesicles Provoked Periodontitis and Cognitive Impairment by Lactobacillus pentosus NK357 and Bifidobacterium bifidum NK391. Nutrients 2023; 15:nu15051068. [PMID: 36904068 PMCID: PMC10005711 DOI: 10.3390/nu15051068] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 02/16/2023] [Accepted: 02/19/2023] [Indexed: 02/25/2023] Open
Abstract
Porphyromonas gingivalis (PG) is closely involved in the outbreak of periodontitis and cognitive impairment (CI). Herein, we examined the effects of anti-inflammatory Lactobacillus pentosus NK357 and Bifidobacterium bifidum NK391 on PG- or its extracellular vesicles (pEVs)-induced periodontitis and CI in mice. Oral administration of NK357 or NK391 significantly decreased PG-induced tumor necrosis factor (TNF)-α, receptor activator of nuclear factors κB (RANK), and RANK ligand (RANKL) expression, gingipain (GP)+lipopolysaccharide (LPS)+ and NF-κB+CD11c+ populations, and PG 16S rDNA level in the periodontal tissue. Their treatments also suppressed PG-induced CI -like behaviors, TNF-α expression and NF-κB-positive immune cells in the hippocampus and colon, while PG-suppressed hippocampal BDNF and N-methyl-D-aspartate receptor (NMDAR) expression increased. The combination of NK357 and NK391 additively alleviated PG- or pEVs-induced periodontitis, neuroinflammation, CI-like behaviors, colitis, and gut microbiota dysbiosis and increased PG- or pEVs-suppressed BDNF and NMDAR expression in the hippocampus. In conclusion, NK357 and NK391 may alleviate periodontitis and dementia by regulating NF-κB, RANKL/RANK, and BDNF-NMDAR signaling and gut microbiota.
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12
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Lei S, Li J, Yu J, Li F, Pan Y, Chen X, Ma C, Zhao W, Tang X. Porphyromonas gingivalis bacteremia increases the permeability of the blood-brain barrier via the Mfsd2a/Caveolin-1 mediated transcytosis pathway. Int J Oral Sci 2023; 15:3. [PMID: 36631446 PMCID: PMC9834243 DOI: 10.1038/s41368-022-00215-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Revised: 12/06/2022] [Accepted: 12/09/2022] [Indexed: 01/13/2023] Open
Abstract
Bacteremia induced by periodontal infection is an important factor for periodontitis to threaten general health. P. gingivalis DNA/virulence factors have been found in the brain tissues from patients with Alzheimer's disease (AD). The blood-brain barrier (BBB) is essential for keeping toxic substances from entering brain tissues. However, the effect of P. gingivalis bacteremia on BBB permeability and its underlying mechanism remains unclear. In the present study, rats were injected by tail vein with P. gingivalis three times a week for eight weeks to induce bacteremia. An in vitro BBB model infected with P. gingivalis was also established. We found that the infiltration of Evans blue dye and Albumin protein deposition in the rat brain tissues were increased in the rat brain tissues with P. gingivalis bacteremia and P. gingivalis could pass through the in vitro BBB model. Caveolae were detected after P. gingivalis infection in BMECs both in vivo and in vitro. Caveolin-1 (Cav-1) expression was enhanced after P. gingivalis infection. Downregulation of Cav-1 rescued P. gingivalis-enhanced BMECs permeability. We further found P. gingivalis-gingipain could be colocalized with Cav-1 and the strong hydrogen bonding between Cav-1 and arg-specific-gingipain (RgpA) were detected. Moreover, P. gingivalis significantly inhibited the major facilitator superfamily domain containing 2a (Mfsd2a) expression. Mfsd2a overexpression reversed P. gingivalis-increased BMECs permeability and Cav-1 expression. These results revealed that Mfsd2a/Cav-1 mediated transcytosis is a key pathway governing BBB BMECs permeability induced by P. gingivalis, which may contribute to P. gingivalis/virulence factors entrance and the subsequent neurological impairments.
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Affiliation(s)
- Shuang Lei
- Department of Periodontics, School and Hospital of Stomatology, Liaoning Provincial Key Laboratory of Oral Disease, China Medical University, No. 117, Nanjing North Street, Heping District, Shenyang, China
- Department of Pediatric Dentistry, School and Hospital of Stomatology, Liaoning Provincial Key Laboratory of Oral Disease, China Medical University, No. 117, Nanjing North Street, Heping District, Shenyang, China
| | - Jian Li
- Department of Preventive Dentistry, School and Hospital of Stomatology, Liaoning Provincial Key Laboratory of Oral Disease, China Medical University, Shenyang, China
| | - Jingjun Yu
- Department of Periodontics, School and Hospital of Stomatology, Liaoning Provincial Key Laboratory of Oral Disease, China Medical University, No. 117, Nanjing North Street, Heping District, Shenyang, China
| | - Fulong Li
- Department of Periodontics, School and Hospital of Stomatology, Liaoning Provincial Key Laboratory of Oral Disease, China Medical University, No. 117, Nanjing North Street, Heping District, Shenyang, China
| | - Yaping Pan
- Department of Periodontics, School and Hospital of Stomatology, Liaoning Provincial Key Laboratory of Oral Disease, China Medical University, No. 117, Nanjing North Street, Heping District, Shenyang, China
| | - Xu Chen
- Department of Pediatric Dentistry, School and Hospital of Stomatology, Liaoning Provincial Key Laboratory of Oral Disease, China Medical University, No. 117, Nanjing North Street, Heping District, Shenyang, China
| | - Chunliang Ma
- Department of Periodontics, School and Hospital of Stomatology, Liaoning Provincial Key Laboratory of Oral Disease, China Medical University, No. 117, Nanjing North Street, Heping District, Shenyang, China
| | - Weidong Zhao
- Department of Developmental Cell Biology, Key Laboratory of Cell Biology, China Medical University, 77 Puhe Road, Shenbei New District, Shenyang, China
| | - Xiaolin Tang
- Department of Periodontics, School and Hospital of Stomatology, Liaoning Provincial Key Laboratory of Oral Disease, China Medical University, No. 117, Nanjing North Street, Heping District, Shenyang, China.
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13
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Li X, Zhao K, Chen J, Ni Z, Yu Z, Hu L, Qin Y, Zhao J, Peng W, Lu L, Gao X, Sun H. Diurnal changes of the oral microbiome in patients with alcohol dependence. Front Cell Infect Microbiol 2022; 12:1068908. [PMID: 36579346 PMCID: PMC9791055 DOI: 10.3389/fcimb.2022.1068908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Accepted: 11/28/2022] [Indexed: 12/14/2022] Open
Abstract
Background Saliva secretion and oral microbiota change in rhythm with our biological clock. Dysbiosis of the oral microbiome and alcohol consumption have a two-way interactive impact, but little is known about whether the oral microbiome undergoes diurnal changes in composition and function during the daytime in patients with alcohol dependence (AD). Methods The impact of alcohol consumption on the diurnal salivary microbiome was examined in a case-control study of 32 AD patients and 21 healthy control (HC) subjects. We tested the changes in microbial composition and individual taxon abundance by 16S rRNA gene sequencing. Results The present study is the first report showing that alcohol consumption enhanced the richness of the salivary microbiome and lowered the evenness. The composition of the oral microbiota changed significantly in alcohol-dependent patients. Additionally, certain genera were enriched in the AD group, including Actinomyces, Leptotrichia, Sphaerochaeta and Cyanobacteria, all of which have pathogenic effects on the host. There is a correlation between liver enzymes and oral microbiota. KEGG function analysis also showed obvious alterations during the daytime. Conclusion Alcohol drinking influences diurnal changes in the oral microbiota, leading to flora disturbance and related functional impairment. In particular, the diurnal changes of the oral microbiota may open avenues for potential interventions that can relieve the detrimental consequences of AD.
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Affiliation(s)
- Xiangxue Li
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, China
| | - Kangqing Zhao
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, China
| | - Jie Chen
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, China
| | - Zhaojun Ni
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, China
| | - Zhoulong Yu
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, China
| | - Lingming Hu
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, China
| | - Ying Qin
- Addiction Medicine Department, The Second People’s Hospital of Guizhou Province, Guizhou, China
| | - Jingwen Zhao
- Addiction Medicine Department, The Second People’s Hospital of Guizhou Province, Guizhou, China
| | - Wenjuan Peng
- Addiction Medicine Department, The Second People’s Hospital of Guizhou Province, Guizhou, China
| | - Lin Lu
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, China
| | - Xuejiao Gao
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, China,*Correspondence: Xuejiao Gao, ; Hongqiang Sun,
| | - Hongqiang Sun
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, China,*Correspondence: Xuejiao Gao, ; Hongqiang Sun,
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14
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Gong T, Chen Q, Mao H, Zhang Y, Ren H, Xu M, Chen H, Yang D. Outer membrane vesicles of Porphyromonas gingivalis trigger NLRP3 inflammasome and induce neuroinflammation, tau phosphorylation, and memory dysfunction in mice. Front Cell Infect Microbiol 2022; 12:925435. [PMID: 36017373 PMCID: PMC9397999 DOI: 10.3389/fcimb.2022.925435] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 07/01/2022] [Indexed: 11/13/2022] Open
Abstract
BackgroundPorphyromonas gingivalis (Pg), the keystone pathogen in chronic periodontitis, is reported to initiate Alzheimer’s disease pathologies in preclinical studies. However, the specific mechanisms and signaling pathways acting on the brain still need to be further explored. Outer membrane vesicles are derived from Gram-negative bacteria and contain many virulence factors of bacteria. We hypothesized that outer membrane vesicles are an important weapon of Porphyromonas gingivalis to initiate Alzheimer’s disease pathologies.MethodsThe outer membrane vesicles of Porphyromonas gingivalis (Pg OMVs, 4 mg/kg) or saline were delivered to 14-month-old mice by oral gavage every other day for eight weeks. Behavioral alterations were assessed by the open field test, Morris water maze, and Y-maze test. Blood–brain barrier permeability, neuroinflammation, tau phosphorylation, and NLRP3 inflammasome-related protein were analyzed.ResultsPg OMVs impaired memory and learning ability of mice and decreased tight junction–related gene expression ZO-1, occludin, claudin-5, and occludin protein expression in the hippocampus. Pg OMVs could be detected in the hippocampus and cortex three days after oral gavage. Furthermore, Pg OMVs activated both astrocytes and microglia and elevated IL-1β, tau phosphorylation on the Thr231 site, and NLRP3 inflammasome–related protein expression in the hippocampus. In in vitro studies, Pg OMV (5 µg/ml) stimulation increased the mRNA and immunofluorescence of NLRP3 in BV2 microglia, which were significantly inhibited by the NLRP3 inhibitor MCC950. In contrast, the tau phosphorylation in N2a neurons was enhanced after treatment with conditioned media from Pg OMV-stimulated microglia, which was attenuated after pretreatment with MCC950.ConclusionsThese results indicate that Pg OMVs prompt memory dysfunction, neuroinflammation, and tau phosphorylation and trigger NLRP3 inflammasome in the brain of middle-aged mice. We propose that Pg OMVs play an important role in activating neuroinflammation in the AD-like pathology triggered by Porphyromonas gingivalis, and NLRP3 inflammasome activation is a possible mechanism.
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Affiliation(s)
- Ting Gong
- Department of Endodontics, Stomatological Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing Medical University, Chongqing, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing Medical University, Chongqing, China
| | - Qi Chen
- Department of Endodontics, Stomatological Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing Medical University, Chongqing, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing Medical University, Chongqing, China
| | - Hongchen Mao
- Department of Endodontics, Stomatological Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing Medical University, Chongqing, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing Medical University, Chongqing, China
| | - Yao Zhang
- Department of Endodontics, Stomatological Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing Medical University, Chongqing, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing Medical University, Chongqing, China
| | - Huan Ren
- Department of Endodontics, Stomatological Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing Medical University, Chongqing, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing Medical University, Chongqing, China
| | - Mengmeng Xu
- Department of Endodontics, Stomatological Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing Medical University, Chongqing, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing Medical University, Chongqing, China
| | - Hong Chen
- Department of Endodontics, Stomatological Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing Medical University, Chongqing, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing Medical University, Chongqing, China
| | - Deqin Yang
- Department of Endodontics, Stomatological Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing Medical University, Chongqing, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing Medical University, Chongqing, China
- *Correspondence: Deqin Yang,
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15
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Moore C, Cheng Y, Tjokro N, Zhang B, Kerr M, Hayati M, Chang KCJ, Shah N, Chen C, Jokerst JV. A Photoacoustic-Fluorescent Imaging Probe for Proteolytic Gingipains Expressed by Porphyromonas gingivalis. Angew Chem Int Ed Engl 2022; 61:e202201843. [PMID: 35583940 PMCID: PMC9296565 DOI: 10.1002/anie.202201843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Indexed: 11/07/2022]
Abstract
Porphyromonas gingivalis is a keystone pathogen in periodontal disease. We herein report a dual-modal fluorescent and photoacoustic imaging probe for the detection of gingipain proteases secreted by P. gingivalis. Upon proteolytic cleavage by Arg-specific gingipain (RgpB), five-fold photoacoustic enhancement and >100-fold fluorescence activation was measured with detection limits of 1.1 nM RgpB and 5.0E4 CFU mL-1 bacteria in vitro. RgpB activity was imaged in porcine jaws with low-nanomolar sensitivity. Diagnostic efficacy was evaluated in gingival crevicular fluid samples from subjects with and without periodontal disease, wherein activation was correlated to qPCR-based detection of P. gingivalis (Pearson's r=0.71). Finally, photoacoustic imaging of RgpB-cleaved probe was achieved in murine brains ex vivo, with relevance and potential utility for disease models of general infection by P. gingivalis, motivated by the recent biological link between gingipain and Alzheimer's disease.
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Affiliation(s)
- Colman Moore
- Department of NanoEngineering, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093. USA
| | - Yong Cheng
- Department of NanoEngineering, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093. USA
| | - Natalia Tjokro
- Herman Ostrow School of Dentistry, University of Southern California, 925 West 34 Street, Los Angeles, CA 90089. USA
| | - Brendan Zhang
- Department of NanoEngineering, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093. USA
| | - Matthew Kerr
- Department of NanoEngineering, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093. USA
| | - Mohammed Hayati
- Herman Ostrow School of Dentistry, University of Southern California, 925 West 34 Street, Los Angeles, CA 90089. USA
| | - Kai Chiao Joe Chang
- Herman Ostrow School of Dentistry, University of Southern California, 925 West 34 Street, Los Angeles, CA 90089. USA
| | - Nisarg Shah
- Department of NanoEngineering, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093. USA
| | - Casey Chen
- Herman Ostrow School of Dentistry, University of Southern California, 925 West 34 Street, Los Angeles, CA 90089. USA
| | - Jesse V. Jokerst
- Department of NanoEngineering, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093. USA
- Materials Science Program, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093. USA
- Department of Radiology, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093. USA
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16
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Moore C, Cheng Y, Tjokro N, Zhang B, Kerr M, Hayati M, Chang KCJ, Shah N, Chen C, Jokerst JV. A Photoacoustic‐Fluorescent Imaging Probe for Proteolytic Gingipains Expressed by
Porphyromonas gingivalis. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202201843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Colman Moore
- Department of NanoEngineering University of California, San Diego 9500 Gilman Dr. La Jolla CA 92093 USA
| | - Yong Cheng
- Department of NanoEngineering University of California, San Diego 9500 Gilman Dr. La Jolla CA 92093 USA
| | - Natalia Tjokro
- Herman Ostrow School of Dentistry University of Southern California 925 West 34th Street Los Angeles CA 90089 USA
| | - Brendan Zhang
- Department of NanoEngineering University of California, San Diego 9500 Gilman Dr. La Jolla CA 92093 USA
- Current address: Diazyme Laboratories Inc
| | - Matthew Kerr
- Department of NanoEngineering University of California, San Diego 9500 Gilman Dr. La Jolla CA 92093 USA
| | - Mohammed Hayati
- Herman Ostrow School of Dentistry University of Southern California 925 West 34th Street Los Angeles CA 90089 USA
| | - Kai Chiao Joe Chang
- Herman Ostrow School of Dentistry University of Southern California 925 West 34th Street Los Angeles CA 90089 USA
| | - Nisarg Shah
- Department of NanoEngineering University of California, San Diego 9500 Gilman Dr. La Jolla CA 92093 USA
| | - Casey Chen
- Herman Ostrow School of Dentistry University of Southern California 925 West 34th Street Los Angeles CA 90089 USA
| | - Jesse V. Jokerst
- Department of NanoEngineering University of California, San Diego 9500 Gilman Dr. La Jolla CA 92093 USA
- Materials Science Program University of California, San Diego 9500 Gilman Dr. La Jolla CA 92093 USA
- Department of Radiology University of California, San Diego 9500 Gilman Dr. La Jolla CA 92093 USA
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17
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Lu H, Zou P, Zhang Y, Zhang Q, Chen Z, Chen F. The sampling strategy of oral microbiome. IMETA 2022; 1:e23. [PMID: 38868567 PMCID: PMC10989882 DOI: 10.1002/imt2.23] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 04/01/2022] [Accepted: 04/15/2022] [Indexed: 06/14/2024]
Abstract
There are multiple habitats in the oral cavity with bacteria, fungi, viruses, and protozoa residing in, which together constitute the oral micro-ecosystem. These microflorae in the oral cavity primarily include saliva, supragingival dental plaque, subgingival dental plaque, submucosal plaque around implants, plaque in root canals, and plaque on the mucosal surface. The interest and knowledge of the microbiome have dynamically increased with the advancement of technology. Therefore, a reliable, feasible, and practical sampling strategy for the oral microbiome is required for the investigation. This paper introduced the sampling strategy of oral microorganisms, consisting of sample collection, transport, processing, and storage. The materials and devices involved in this study are all commonly used in clinical practice or laboratory. The feasibility and reliability of the sampling methods described in this paper have been verified by multiple studies.
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Affiliation(s)
- Hongye Lu
- Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang ProvinceCancer Center of Zhejiang UniversityHangzhouChina
- Department of Periodontology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital StomatologyPeking University School and Hospital of StomatologyBeijingChina
| | - Peihui Zou
- Department of Periodontology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital StomatologyPeking University School and Hospital of StomatologyBeijingChina
| | - Yifei Zhang
- Central Laboratory, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital StomatologyBeijingChina
| | - Qian Zhang
- Central Laboratory, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital StomatologyBeijingChina
| | - Zhibin Chen
- Department of Periodontology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital StomatologyPeking University School and Hospital of StomatologyBeijingChina
| | - Feng Chen
- Central Laboratory, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital StomatologyBeijingChina
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18
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Harding A, Kanagasingam S, Welbury R, Singhrao SK. Periodontitis as a Risk Factor for Alzheimer's Disease: The Experimental Journey So Far, with Hope of Therapy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1373:241-260. [PMID: 35612802 DOI: 10.1007/978-3-030-96881-6_13] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Periodontitis and Alzheimer's disease (AD) exist globally within the adult population. Given that the risk of AD incidence doubles within 10 years from the time of periodontal disease diagnosis, there is a window of opportunity for slowing down or preventing AD by risk-reduction-based intervention. Literature appraisal on the shared risk factors of these diseases suggests a shift to a healthy lifestyle would be beneficial. Generalised (chronic) periodontitis with an established dysbiotic polymicrobial aetiology affects the tooth supporting tissues with eventual tooth loss. The cause of AD remains unknown, however two neurohistopathological lesions - amyloid-beta plaques and neurofibrillary tangles, together with the clinical history, provide AD diagnosis at autopsy. Historically, prominence was given to the two hallmark lesions but now emphasis is placed on cerebral inflammation and what triggers it. Low socioeconomic status promotes poor lifestyles that compromise oral and personal hygiene along with reliance on poor dietary intake. Taken together with advancing age and a declining immune protection, these risk factors may negatively impact on periodontitis and AD. These factors also provide a tangible solution to controlling pathogenic bacteria indigenous to the oral and gastrointestinal tract microbioes in vulnerable subjects. The focus here is on Porphyromonas gingivalis, one of several important bacterial pathogens associated with both periodontitis and AD. Recent research has enabled advances in our knowledge of the armoury of P. gingivalis via reproduction of all clinical and neuropathological hallmark lesions of AD and chronic periodontal disease in vitro and in vivo experimental models, thus paving the way for better future management.
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Affiliation(s)
- Alice Harding
- Brain and Behavior Centre, Faculty of Clinical and Biomedical Sciences, School of Dentistry, University of Central Lancashire, Preston, UK
| | - Shalini Kanagasingam
- Brain and Behavior Centre, Faculty of Clinical and Biomedical Sciences, School of Dentistry, University of Central Lancashire, Preston, UK
| | - Richard Welbury
- Brain and Behavior Centre, Faculty of Clinical and Biomedical Sciences, School of Dentistry, University of Central Lancashire, Preston, UK
| | - Sim K Singhrao
- Brain and Behavior Centre, Faculty of Clinical and Biomedical Sciences, School of Dentistry, University of Central Lancashire, Preston, UK.
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19
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Kouki MA, Pritchard AB, Alder JE, Crean S. Do Periodontal Pathogens or Associated Virulence Factors Have a Deleterious Effect on the Blood-Brain Barrier, Contributing to Alzheimer's Disease? J Alzheimers Dis 2021; 85:957-973. [PMID: 34897087 DOI: 10.3233/jad-215103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The central nervous system (CNS) is protected by a highly selective barrier, the blood-brain barrier (BBB), that regulates the exchange and homeostasis of bloodborne molecules, excluding xenobiotics. This barrier forms the first line of defense by prohibiting pathogens from crossing to the CNS. Aging and chronic exposure of the BBB to pathogens renders it permeable, and this may give rise to pathology in the CNS such as Alzheimer's disease (AD). Researchers have linked pathogens associated with periodontitis to neuroinflammation and AD-like pathology in vivo and in vitro. Although the presence of periodontitis-associated bacteria has been linked to AD in several clinical studies as DNA and virulence factors were confirmed in brain samples of human AD subjects, the mechanism by which the bacteria traverse to the brain and potentially influences neuropathology is unknown. In this review, we present current knowledge about the association between periodontitis and AD, the mechanism whereby periodontal pathogens might provoke neuroinflammation and how periodontal pathogens could affect the BBB. We suggest future studies, with emphasis on the use of human in vitro models of cells associated with the BBB to unravel the pathway of entry for these bacteria to the CNS and to reveal the molecular and cellular pathways involved in initiating the AD-like pathology. In conclusion, evidence demonstrate that bacteria associated with periodontitis and their virulence factors are capable of inflecting damage to the BBB and have a role in giving rise to pathology similar to that found in AD.
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Affiliation(s)
- Mhd Ammar Kouki
- Brain and Behaviour Centre, Faculty of Clinical and Biomedical Sciences, School of Pharmacy and Biomedical Sciences, University of Central Lancashire, Preston, UK
| | - Anna Barlach Pritchard
- Brain and Behaviour Centre, Faculty of Clinical and Biomedical Sciences, School of Dentistry, University of Central Lancashire, Preston, UK
| | - Jane Elizabeth Alder
- Brain and Behaviour Centre, Faculty of Clinical and Biomedical Sciences, School of Pharmacy and Biomedical Sciences, University of Central Lancashire, Preston, UK
| | - StJohn Crean
- Brain and Behaviour Centre, Faculty of Clinical and Biomedical Sciences, School of Dentistry, University of Central Lancashire, Preston, UK
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20
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Bachtiar EW, Septiwidyati TR. Possible Role of Porphyromonas gingivalis in the Regulation of E2F1, CDK11, and iNOS Gene Expression in Neuronal Cell Cycle: A Preliminary Study. J Int Soc Prev Community Dent 2021; 11:582-587. [PMID: 34760804 PMCID: PMC8533040 DOI: 10.4103/jispcd.jispcd_108_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 06/30/2021] [Accepted: 07/26/2021] [Indexed: 12/04/2022] Open
Abstract
Objective: This study aimed at evaluating the in vitro effect of Porphyromonas gingivalis exposure in gene expression of E2F1 (family of transcription factors), cyclin-dependent kinase-1 (CDK11), and inducible nitric oxide synthase (iNOS) of the neuronal cell cycle. Materials and Methods: The culture of neuronal cell line SH-SY5Y was exposed to P. gingivalis ATCC 33277, and the gene expression of E2F1, CDK11, and iNOS was analyzed by using a real-time polymerase chain reaction. Results: It was shown that E2F1, a G1 phase biomarker and transcription factor, was upregulated in neuronal cells exposed to P. gingivalis compared with that in control cells. However, CDK11, a biomarker of G2/M checkpoint and iNOS, was downregulated in neuronal cells exposed to P. gingivalis compared with that in control cells. Conclusions: P. gingivalis can regulate the neuronal cell cycle, as indicated in the E2F1, CDK11, and iNOS gene expression.
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Affiliation(s)
- Endang W Bachtiar
- Department of Oral Biology and Oral Science Research Center, Faculty of Dentistry, Universitas Indonesia, Jakarta, Indonesia
| | - Tienneke R Septiwidyati
- Department of Oral Biology and Oral Science Research Center, Faculty of Dentistry, Universitas Indonesia, Jakarta, Indonesia
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21
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Li A, Chen Y, Visser A, Marks LAM, Tjakkes GHE. Combined association of cognitive impairment and poor oral health on mortality risk in older adults: Results from the NHANES with 15 years of follow-up. J Periodontol 2021; 93:888-900. [PMID: 34533839 PMCID: PMC9298999 DOI: 10.1002/jper.21-0292] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 08/22/2021] [Accepted: 09/08/2021] [Indexed: 12/14/2022]
Abstract
Background Cognitive impairment and poor oral health are frequently seen among older adults. Both conditions have been identified as risk factors for mortality. However, the combined associations of cognitive impairment and poor oral health with mortality have not been well studied and are therefore the aim of this cohort study. Methods We analyzed data from the National Health and Nutrition Examination Survey (1999–2002) linked with mortality data obtained from the 2015 public‐use linked mortality file. Cognitive impairment was defined as a digit symbol substitution test score lower than the lowest quartile. Oral health status was assessed based on presence of untreated caries, moderate to severe periodontitis, and edentulism. The combined effects of caries/periodontitis or edentulism and cognitive impairment on all‐cause and cardiometabolic mortality were examined using the Cox proportional hazard models after adjusting for potential confounders including demographic characteristics, lifestyle, biomarkers, and comorbidities. Results In total, 1973 participants were enrolled in the prospective study. At a median follow‐up of 13.4 years, 978 participants had died (264 deaths because of cardiometabolic disease). Cognitive impairment, periodontitis, and edentulism were each found to be significant predictors of all‐cause mortality. Caries, however, was not significantly related to mortality. When analyzing these predictors in combination, a diagnosis of cognitive impairment and periodontitis was associated with an 83.1% increase in all‐cause mortality risk and an 87.7% increase in cardiometabolic mortality risk compared with healthy controls. Similarly, the risk for all‐cause mortality was highest in cases where impaired cognition and edentulism co‐occurred (adjusted hazard ratio = 1.701, 1.338–2.161). Conclusion Concomitant presence of cognitive impairment and periodontitis or edentulism can be associated with a higher risk of mortality among older U.S. adults.
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Affiliation(s)
- An Li
- Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.,Stomatological Hospital, Southern Medical University, Guangzhou, China
| | - Yuntao Chen
- Medical Statistics and Decision-Making, Department of Epidemiology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Anita Visser
- Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.,Department of Maxillofacial Surgery, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Luc A M Marks
- Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Geerten-Has E Tjakkes
- Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
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22
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Elwishahy A, Antia K, Bhusari S, Ilechukwu NC, Horstick O, Winkler V. Porphyromonas Gingivalis as a Risk Factor to Alzheimer's Disease: A Systematic Review. J Alzheimers Dis Rep 2021; 5:721-732. [PMID: 34755046 PMCID: PMC8543378 DOI: 10.3233/adr-200237] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/16/2021] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Alzheimer's disease (AD) is a chronic neurodegenerative disease that accounts for more than 50% of all dementia cases worldwide. There is wide consensus on the risk factors of AD; however, a clear etiology remains unknown. Evidence suggests that the inflammatory-mediated disease model, such as that found with periodontal disease due to Porphyromonas gingivalis (P. gingivalis), plays a role in AD progression. OBJECTIVE This study aims to systematically review the literature on the association between P. gingivalis to AD, and to identify the homogeneity of the methods used across studies to measure P. gingivalis involvement in AD. METHODS We systematically searched studies on Cochrane library, Ovid Medline, PubMed, Web of Science, WHOLIS, Google Scholar databases, and reference lists of identified studies. RESULTS 6 studies out of 636 identified records fulfilled all eligibility criteria. Results showed no clear pathophysiology of AD due to P. gingivalis and its various virulence factors. No consensus was found in the literature pertaining to the method of measurement of AD or P. gingivalis and its virulence factors. CONCLUSION The included studies suggest that P. gingivalis bacteria play a role in the process of systemic inflammation which leads to cerebrospinal fluid inflammation and indirectly cause hastening of AD onset and progression. Our included studies revealed heterogeneity in the methodologies of measurement of AD and/or P. gingivalis and its virulence factors, which opens discussion about the benefits and weakness of possible standardization.
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Affiliation(s)
- Abdelrahman Elwishahy
- Heidelberg Institute of Global Health, Heidelberg University Hospital, Heidelberg, Germany
| | - Khatia Antia
- Heidelberg Institute of Global Health, Heidelberg University Hospital, Heidelberg, Germany
| | - Sneha Bhusari
- Heidelberg Institute of Global Health, Heidelberg University Hospital, Heidelberg, Germany
| | | | - Olaf Horstick
- Heidelberg Institute of Global Health, Heidelberg University Hospital, Heidelberg, Germany
| | - Volker Winkler
- Heidelberg Institute of Global Health, Heidelberg University Hospital, Heidelberg, Germany
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23
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Bisogno T, Lauritano A, Piscitelli F. The Endocannabinoid System: A Bridge between Alzheimer's Disease and Gut Microbiota. Life (Basel) 2021; 11:934. [PMID: 34575083 PMCID: PMC8470731 DOI: 10.3390/life11090934] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 09/03/2021] [Accepted: 09/04/2021] [Indexed: 12/12/2022] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease that progresses from mild cognitive impairment to severe dementia over time. The main clinical hallmarks of the disease (e.g., beta-amyloid plaques and neurofibrillary tangles) begin during preclinical AD when cognitive deficits are not yet apparent. Hence, a more profound understanding of AD pathogenesis is needed to develop new therapeutic strategies. In this context, the endocannabinoid (eCB) system and the gut microbiome are increasingly emerging as important players in maintaining the general homeostasis and the health status of the host. However, their interaction has come to light just recently with gut microbiota regulating the eCB tone at both receptor and enzyme levels in intestinal and adipose tissues. Importantly, eCB system and gut microbiome, have been suggested to play a role in AD in both animal and human studies. Therefore, the microbiome gut-brain axis and the eCB system are potential common denominators in the AD physiopathology. Hence, the aim of this review is to provide a general overview on the role of both the eCB system and the microbiome gut-brain axis in AD and to suggest possible mechanisms that underlie the potential interplay of these two systems.
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Affiliation(s)
- Tiziana Bisogno
- Endocannabinoid Research Group, Istituto di Farmacologia Traslazionale, Consiglio Nazionale Delle Ricerche, Area Della Ricerca di Roma 2 Via Fosso del Cavaliere 100, 00133 Roma, Italy
| | - Anna Lauritano
- Endocannabinoid Research Group, Istituto di Chimica Biomolecolare, Via Campi Flegrei 34, 80078 Pozzuoli, Italy;
| | - Fabiana Piscitelli
- Endocannabinoid Research Group, Istituto di Chimica Biomolecolare, Via Campi Flegrei 34, 80078 Pozzuoli, Italy;
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24
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Shi M, Li C, Tian X, Chu F, Zhu J. Can Control Infections Slow Down the Progression of Alzheimer's Disease? Talking About the Role of Infections in Alzheimer's Disease. Front Aging Neurosci 2021; 13:685863. [PMID: 34366826 PMCID: PMC8339924 DOI: 10.3389/fnagi.2021.685863] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 06/24/2021] [Indexed: 01/07/2023] Open
Abstract
Alzheimer’s disease as the most common age-related dementia affects more than 40 million people in the world, representing a global public health priority. However, the pathogenesis of Alzheimer’s disease (AD) is complex, and it remains unclear. Over the past decades, all efforts made in the treatments of AD, with targeting the pathogenic amyloid β (Aβ), neurofibrillary tangles, and misfolded tau protein, were failed. Recently, many studies have hinted that infection, and chronic inflammation that caused by infection are crucial risk factors for AD development and progress. In the review, we analyzed the role of infections caused by bacteria, viruses, and other pathogens in the pathogenesis of AD and its animal models, and explored the therapeutic possibility with anti-infections for AD. However, based on the published data, it is still difficult to determine their causal relationship between infection and AD due to contradictory results. We think that the role of infection in the pathogenesis of AD should not be ignored, even though infection does not necessarily cause AD, it may act as an accelerator in AD at least. It is essential to conduct the longitudinal studies and randomized controlled trials in humans, which can determine the role of infection in AD and clarify the links between infection and the pathological features of AD. Finding targeting infection drugs and identifying the time window for applying antibacterial or antiviral intervention may be more promising for future clinical therapeutic strategies in AD.
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Affiliation(s)
- Mingchao Shi
- Department of Neurology, Neuroscience Center, The First Hospital of Jilin University, Changchun, China.,Division of Neurogeriatrcs, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Karolinska University Hospital, Solna, Sweden
| | - Chunrong Li
- Department of Neurology, Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Xiaoping Tian
- Cognitive Impairment Ward of Neurology Department, The Third Affiliated Hospital of Shenzhen University Medical College, Shenzhen, China
| | - Fengna Chu
- Department of Neurology, Neuroscience Center, The First Hospital of Jilin University, Changchun, China.,Division of Neurogeriatrcs, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Karolinska University Hospital, Solna, Sweden
| | - Jie Zhu
- Department of Neurology, Neuroscience Center, The First Hospital of Jilin University, Changchun, China.,Division of Neurogeriatrcs, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Karolinska University Hospital, Solna, Sweden
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25
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Imai J, Kitamoto S, Kamada N. The pathogenic oral-gut-liver axis: new understandings and clinical implications. Expert Rev Clin Immunol 2021; 17:727-736. [PMID: 34057877 DOI: 10.1080/1744666x.2021.1935877] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
INTRODUCTION Oral health is closely related to extra-oral disease status, as may be represented by the manifestations of gastrointestinal and liver diseases. AREAS COVERED This review focuses on the roles that the oral-gut or the oral-gut-liver axis play in the pathogenesis of inflammatory bowel disease, colorectal cancer, metabolic fatty liver disease, and nonalcoholic steatohepatitis. The discussion will begin with clinical data, including data from preclinical animal models, to elucidate mechanisms. We will also discuss ways to target oral dysbiosis and oral inflammation to treat gastrointestinal and liver diseases. EXPERT OPINION Several studies have demonstrated that oral pathobionts can translocate to the gastrointestinal tract where they contribute to inflammation and tumorigenesis. Furthermore, oral bacteria that migrate to the gastrointestinal tract can disseminate to the liver and cause hepatic disease. Thus, oral bacteria that ectopically colonize the intestine may serve as biomarkers for gastrointestinal and liver diseases. Also, understanding the characteristics of the oral-gut and oral-gut-liver microbial and immune axes will provide new insights into the pathogenesis of these diseases.
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Affiliation(s)
- Jin Imai
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, United States.,Division of Gastroenterology and Hepatology, Department of Internal Medicine, Tokai University School of Medicine, Isehara, Japan
| | - Sho Kitamoto
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, United States
| | - Nobuhiko Kamada
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, United States
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26
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Elsayed R, Elashiry M, Liu Y, El-Awady A, Hamrick M, Cutler CW. Porphyromonas gingivalis Provokes Exosome Secretion and Paracrine Immune Senescence in Bystander Dendritic Cells. Front Cell Infect Microbiol 2021; 11:669989. [PMID: 34141629 PMCID: PMC8204290 DOI: 10.3389/fcimb.2021.669989] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 05/11/2021] [Indexed: 12/13/2022] Open
Abstract
Periodontitis is a disease of ageing or inflammaging, and is comorbid with other more severe age-related chronic diseases. With advanced age comes an increase in accumulation of senescent cells that release soluble and insoluble pro-inflammatory factors collectively termed the senescence associated secretory phenotype (SASP). In the present report, we examined whether immune cells typical of those at the oral mucosa-microbe interface, are vulnerable to cellular senescence (CS) and the role of dysbiotic oral pathogen Porphyromonas gingivalis. Bone marrow-derived dendritic cells (DCs) from young (yDCs) and old (oDCs) mice were co-cultured in vitro with CS inducer doxorubicin or P.gingivalis (Pg), plus or minus senolytic agent rapamycin. CS profiling revealed elevated CS mediators SA-β-Gal, p16 INK4A, p53, and p21Waf1/Clip1 in oDCs, or yDCs in response to doxorubicin or P. gingivalis, reversible with rapamycin. Functional studies indicate impaired maturation function of oDCs, and yDC exposed to P. gingivalis; moreover, OVA-driven proliferation of CD4+ T cells from young OTII transgenic mice was impaired by oDCs or yDCs+Pg. The SASP of DCs, consisting of secreted exosomes and inflammasome-related cytokines was further analyzed. Exosomes of DCs cocultured with P. gingivalis (PgDCexo) were purified, quantitated and characterized. Though typical in terms of size, shape and phenotype, PgDCexo were 2-fold greater in number than control DCs, with several important distinctions. Namely, PgDCexo were enriched in age-related miRNAs, and miRNAs reported to disrupt immune homeostasis through negative regulation of apoptosis and autophagy functions. We further show that PgDCexo were enriched in P. gingivalis fimbrial adhesin protein mfa1 and in inflammasome related cytokines IL-1β, TNFα and IL-6. Functionally PgDCexo were readily endocytosed by recipient yDCs, amplifying functional impairment in maturation and ability to promote Ova-driven proliferation of OTII CD4+ T cells from young mice. In conclusion P. gingivalis induces premature (autocrine) senescence in DCs by direct cellular invasion and greatly amplifies senescence, in paracrine, of bystander DCs by secretion of inflammatory exosomes. The implications of this pathological pathway for periodontal disease in vivo is under investigation in mouse models.
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Affiliation(s)
- Ranya Elsayed
- Department of Periodontics, Dental College of Georgia, Augusta University, Augusta, GA, United States
| | - Mahmoud Elashiry
- Department of Periodontics, Dental College of Georgia, Augusta University, Augusta, GA, United States
| | - Yutao Liu
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta, GA, United States
| | - Ahmed El-Awady
- Department of Periodontics, Dental College of Georgia, Augusta University, Augusta, GA, United States
| | - Mark Hamrick
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta, GA, United States
| | - Christopher W. Cutler
- Department of Periodontics, Dental College of Georgia, Augusta University, Augusta, GA, United States,*Correspondence: Christopher W. Cutler,
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27
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Contini C, Olianas A, Serrao S, Deriu C, Iavarone F, Boroumand M, Bizzarro A, Lauria A, Faa G, Castagnola M, Messana I, Manconi B, Masullo C, Cabras T. Top-Down Proteomics of Human Saliva Highlights Anti-inflammatory, Antioxidant, and Antimicrobial Defense Responses in Alzheimer Disease. Front Neurosci 2021; 15:668852. [PMID: 34121996 PMCID: PMC8189262 DOI: 10.3389/fnins.2021.668852] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 04/06/2021] [Indexed: 12/13/2022] Open
Abstract
Alzheimer disease (AD) is the most prevalent neurodegenerative disease in the elderly, characterized by accumulation in the brain of misfolded proteins, inflammation, and oxidative damage leading to neuronal cell death. By considering the viewpoint that AD onset and worsening may be influenced by environmental factors causing infection, oxidative stress, and inflammatory reaction, we investigated the changes of the salivary proteome in a population of patients with respect to that in healthy controls (HCs). Indeed, the possible use of saliva as a diagnostic tool has been explored in several oral and systemic diseases. Moreover, the oral cavity continuously established adaptative and protective processes toward exogenous stimuli. In the present study, qualitative/quantitative variations of 56 salivary proteoforms, including post-translationally modified derivatives, have been analyzed by RP-HPLC-ESI-IT-MS and MS/MS analyses, and immunological methods were applied to validate MS results. The salivary protein profile of AD patients was characterized by significantly higher levels of some multifaceted proteins and peptides that were either specific to the oral cavity or also expressed in other body districts: (i) peptides involved in the homeostasis of the oral cavity; (ii) proteins acting as ROS/RNS scavengers and with a neuroprotective role, such as S100A8, S100A9, and their glutathionylated and nitrosylated proteoforms; cystatin B and glutathionylated and dimeric derivatives; (iii) proteins with antimicrobial activity, such as α-defensins, cystatins A and B, histatin 1, statherin, and thymosin β4, this last with a neuroprotective role at the level of microglia. These results suggested that, in response to injured conditions, Alzheimer patients established defensive mechanisms detectable at the oral level. Data are available via ProteomeXchange with identifier PXD021538.
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Affiliation(s)
- Cristina Contini
- Dipartimento di Scienze della Vita e dell'Ambiente, Università di Cagliari, Cagliari, Italy
| | - Alessandra Olianas
- Dipartimento di Scienze della Vita e dell'Ambiente, Università di Cagliari, Cagliari, Italy
| | - Simone Serrao
- Dipartimento di Scienze della Vita e dell'Ambiente, Università di Cagliari, Cagliari, Italy
| | - Carla Deriu
- Dipartimento di Scienze della Vita e dell'Ambiente, Università di Cagliari, Cagliari, Italy
| | - Federica Iavarone
- Dipartimento di Scienze Biotecnologiche di Base, Cliniche Intensivologiche e Perioperatorie, Università Cattolica del Sacro Cuore, Rome, Italy.,Fondazione Policlinico Universitario "A. Gemelli" - IRCCS, Rome, Italy
| | - Mozhgan Boroumand
- Laboratorio di Proteomica, Centro Europeo di Ricerca sul Cervello, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Alessandra Bizzarro
- UOC Continuità Assistenziale, Fondazione Policlinico Universitario "A. Gemelli" - IRCCS, Rome, Italy
| | - Alessandra Lauria
- UOC Continuità Assistenziale, Fondazione Policlinico Universitario "A. Gemelli" - IRCCS, Rome, Italy
| | - Gavino Faa
- Dipartimento di Scienze Mediche e Sanità Pubblica, University of Cagliari, Cagliari, Italy
| | - Massimo Castagnola
- Laboratorio di Proteomica, Centro Europeo di Ricerca sul Cervello, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Irene Messana
- Istituto di Scienze e Tecnologie Chimiche "Giulio Natta", Consiglio Nazionale delle Ricerche, Rome, Italy
| | - Barbara Manconi
- Dipartimento di Scienze della Vita e dell'Ambiente, Università di Cagliari, Cagliari, Italy
| | - Carlo Masullo
- Dipartimento di Neuroscienze, Sez. Neurologia, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Tiziana Cabras
- Dipartimento di Scienze della Vita e dell'Ambiente, Università di Cagliari, Cagliari, Italy
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Kamer AR, Pushalkar S, Gulivindala D, Butler T, Li Y, Annam KRC, Glodzik L, Ballman KV, Corby PM, Blennow K, Zetterberg H, Saxena D, de Leon MJ. Periodontal dysbiosis associates with reduced CSF Aβ42 in cognitively normal elderly. ALZHEIMER'S & DEMENTIA (AMSTERDAM, NETHERLANDS) 2021; 13:e12172. [PMID: 33869725 PMCID: PMC8040436 DOI: 10.1002/dad2.12172] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 02/07/2021] [Accepted: 02/08/2021] [Indexed: 12/30/2022]
Abstract
INTRODUCTION Periodontal disease is a chronic, inflammatory bacterial dysbiosis that is associated with both Alzheimer's disease (AD) and Down syndrome. METHODS A total of 48 elderly cognitively normal subjects were evaluated for differences in subgingival periodontal bacteria (assayed by 16S rRNA sequencing) between cerebrospinal fluid (CSF) biomarker groups of amyloid and neurofibrillary pathology. A dysbiotic index (DI) was defined at the genus level as the abundance ratio of known periodontal bacteria to healthy bacteria. Analysis of variance/analysis of covariance (ANOVA/ANCOVA), linear discriminant effect-size analyses (LEfSe) were used to determine the bacterial genera and species differences between the CSF biomarker groups. RESULTS At genera and species levels, higher subgingival periodontal dysbiosis was associated with reduced CSF amyloid beta (Aβ)42 (P = 0.02 and 0.01) but not with P-tau. DISCUSSION We show a selective relationship between periodontal disease bacterial dysbiosis and CSF biomarkers of amyloidosis, but not for tau. Further modeling is needed to establish the direct link between oral bacteria and Aβ.
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Affiliation(s)
- Angela R. Kamer
- Department of Periodontology and Implant DentistryCollege of DentistryNew York UniversityNew YorkUSA
| | - Smruti Pushalkar
- Department of Molecular PathobiologyCollege of DentistryNew York UniversityNew YorkUSA
| | - Deepthi Gulivindala
- Department of Periodontology and Implant DentistryCollege of DentistryNew York UniversityNew YorkUSA
| | - Tracy Butler
- Department of RadiologyWeill Medical CenterBrain Health Imaging Institute Cornell UniversityNew YorkUSA
| | - Yi Li
- Department of RadiologyWeill Medical CenterBrain Health Imaging Institute Cornell UniversityNew YorkUSA
| | | | - Lidia Glodzik
- Department of RadiologyWeill Medical CenterBrain Health Imaging Institute Cornell UniversityNew YorkUSA
| | - Karla V. Ballman
- Division of BiostatisticsDepartment of Population Health SciencesWeill Medical CenterWeill Cornell MedicineNew YorkUSA
| | - Patricia M. Corby
- Department of Oral MedicineSchool of Dental MedicineUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Kaj Blennow
- Department of Psychiatry and NeurochemistryInstitute of Neuroscience and Physiologythe Sahlgrenska Academy at the University of GothenburgMölndalSweden
- Clinical Neurochemistry LaboratorySahlgrenska University HospitalMölndalSweden
| | - Henrik Zetterberg
- Department of Psychiatry and NeurochemistryInstitute of Neuroscience and Physiologythe Sahlgrenska Academy at the University of GothenburgMölndalSweden
- Clinical Neurochemistry LaboratorySahlgrenska University HospitalMölndalSweden
- Department of Neurodegenerative DiseaseUCL Institute of NeurologyLondonUK
- UK Dementia Research Institute at UCLLondonUK
| | - Deepak Saxena
- Department of Molecular PathobiologyCollege of DentistryNew York UniversityNew YorkUSA
| | - Mony J. de Leon
- Department of RadiologyWeill Medical CenterBrain Health Imaging Institute Cornell UniversityNew YorkUSA
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Fouillen A, Mary C, Ponce KJ, Moffatt P, Nanci A. A proline rich protein from the gingival seal around teeth exhibits antimicrobial properties against Porphyromonas gingivalis. Sci Rep 2021; 11:2353. [PMID: 33504866 PMCID: PMC7840901 DOI: 10.1038/s41598-021-81791-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 01/08/2021] [Indexed: 12/22/2022] Open
Abstract
The gingival seal around teeth prevents bacteria from destroying the tooth-supporting tissues and disseminating throughout the body. Porphyromonas gingivalis, a major periodontopathogen, degrades components of the specialized extracellular matrix that mediates attachment of the gingiva to the tooth. Of these, secretory calcium-binding phosphoprotein proline-glutamine rich 1 (SCPPPQ1) protein has a distinctive resistance to degradation, suggesting that it may offer resistance to bacterial attack. In silico analysis of its amino acid sequence was used to explore its molecular characteristics and to predict its two- and three-dimensional structure. SCPPPQ1 exhibits similarities with both proline-rich and cationic antimicrobial proteins, suggesting a putative antimicrobial potential. A combination of imaging approaches showed that incubation with 20 μM of purified SCPPPQ1 decrease bacterial number (p < 0.01). Fluorescence intensity decreased by 70% following a 2 h incubation of Porphyromonas gingivalis with the protein. Electron microscopy analyses revealed that SCPPPQ1 induced bacterial membrane disruption and breaches. While SCPPPQ1 has no effect on mammalian cells, our results suggest that it is bactericidal to Porphyromonas gingivalis, and that this protein, normally present in the gingival seal, may be exploited to maintain a healthy seal and prevent systemic dissemination of bacteria.
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Affiliation(s)
- Aurélien Fouillen
- Laboratory for the Study of Calcified Tissues and Biomaterials, Faculty of Dental Medicine, Université de Montréal, Montreal, QC, Canada.,Department of Biochemistry and Molecular Medicine, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Charline Mary
- Laboratory for the Study of Calcified Tissues and Biomaterials, Faculty of Dental Medicine, Université de Montréal, Montreal, QC, Canada.,Department of Biochemistry and Molecular Medicine, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Katia Julissa Ponce
- Department of Biochemistry and Molecular Medicine, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Pierre Moffatt
- Department of Human Genetics, McGill University, Montreal, QC, Canada.,Shriners Hospitals for Children - Canada, Montreal, QC, Canada
| | - Antonio Nanci
- Laboratory for the Study of Calcified Tissues and Biomaterials, Faculty of Dental Medicine, Université de Montréal, Montreal, QC, Canada. .,Department of Biochemistry and Molecular Medicine, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada.
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Relationship of Porphyromonas gingivalis and Alzheimer's disease: a systematic review of pre-clinical studies. Clin Oral Investig 2021; 25:797-806. [PMID: 33469718 DOI: 10.1007/s00784-020-03764-w] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 12/21/2020] [Indexed: 12/13/2022]
Abstract
OBJECTIVES This study aimed to analyze the following PICO question: Are animals infected with Porphyromonas gingivalis (P. gingivalis) or bacterial lipopolysaccharide (Pg-LPS) more affected by neurodegeneration, similar to the pathogenesis generated by Alzheimer's disease (AD), compared with non-infected animals? METHODS Databases PubMed, Lilacs, SciELO, Science Direct, Scopus, Web of Science, and Cochrane were searched for pre-clinical in vivo studies in which mice were infected with P. gingivalis or received Pg-LPS, in order to assess the brain tissue and cognitive impairment. No limit for date or publication language was imposed and this study was registered at the International Prospective Register of Systematic Reviews (PROSPERO), with nine articles included. Syrcle's protocol was used to evaluate bias in the selected studies. RESULTS Nine articles were included. Infection by P. gingivalis or the administration of Pg-LPS increased the production of the inflammatory mediators, TNF-α (tumor necrosis factor-alpha), IL-6 (interleukin-6), and IL-1β (interleukin-1beta), augmented Aβ (amyloid beta) production, and activated the complement system, causing inflammation, brain tissue degeneration, and cognitive impairment, consistent with the damage in AD. CONCLUSIONS Infection by P. gingivalis and Pg-LPS administration appears to be in relation with the pathogenesis of AD by activating the complement cascade, increasing Aβ production and augmenting pro-inflammatory cytokine expression, causing age-dependent brain inflammation, neuroinflammation, and neurodegeneration. CLINICAL RELEVANCE Taking into account the importance of holistic treatment in the dental office, this study focuses on identifying highly prevalent oral diseases, such as periodontal disease, as risk factors for the aggravation of degenerative diseases in the elderly population.
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31
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Kanagasingam S, Chukkapalli SS, Welbury R, Singhrao SK. Porphyromonas gingivalis is a Strong Risk Factor for Alzheimer's Disease. J Alzheimers Dis Rep 2020; 4:501-511. [PMID: 33532698 PMCID: PMC7835991 DOI: 10.3233/adr-200250] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Porphyromonas gingivalis (P. gingivalis) is one of the several important bacterial pathogens associated with the sporadic Alzheimer’s disease (AD). Different serotypes are either capsulated or are non-capsulated. It has been demonstrated that P. gingivalis (non-capsulated) can reproduce the neurodegenerative AD-like changes in vitro, and a capsular P. gingivalis (strain W83) could reproduce the cardinal hallmark lesions of AD in a wild-type mouse model. All P. gingivalis forms express proteolytically active proteases that enable cleavage of the amyloid-β protin precursor (AβPP) and tau resulting in the formation of amyloid-β and neurofibrillary tangles. Tau is an established substrate for gingipains, which can cleave tau into various peptides. Some of the P. gingivalis fragmented tau protein peptides contain “VQIINK” and “VQIVYK” hexapeptide motifs which map to the flanking regions of the microtubule binding domains and are also found in paired helical filaments that form NFTs. P. gingivalis can induce peripheral inflammation in periodontitis and can also initiate signaling pathways that activate kinases, which in turn, phosphorylate neuronal tau. Periodontal disease related inflammation has metabolic implications for an individual’s peripheral and brain health as patients suffering from generalized periodontitis often have related co-morbidities and are “at risk” of developing AD. The aim here is to discuss the role of P. gingivalis behind such associations with the backdrop of huge efforts to test P. gingivalis virulence factors clinically (GAIN Trial: Phase 2/3 Study of COR388 in Subjects with AD) with inhibitors, which may lead to an intervention by reducing the pathogenic bacterial load.
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Affiliation(s)
- Shalini Kanagasingam
- Brain and Behavior Centre, Faculty of Clinical and Biomedical Sciences, School of Dentistry, University of Central Lancashire, Preston, UK
| | - Sasanka S Chukkapalli
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, FL, USA
| | - Richard Welbury
- Brain and Behavior Centre, Faculty of Clinical and Biomedical Sciences, School of Dentistry, University of Central Lancashire, Preston, UK
| | - Sim K Singhrao
- Brain and Behavior Centre, Faculty of Clinical and Biomedical Sciences, School of Dentistry, University of Central Lancashire, Preston, UK
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32
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Scherer RX, Scherer WJ. U.S. state correlations between oral health metrics and Alzheimer's disease mortality, prevalence and subjective cognitive decline prevalence. Sci Rep 2020; 10:20962. [PMID: 33262437 PMCID: PMC7708488 DOI: 10.1038/s41598-020-77937-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 11/17/2020] [Indexed: 01/21/2023] Open
Abstract
Given the association between periodontal disease (PdD) and Alzheimer’s disease (AD), we examined correlations between states’ age-adjusted AD mortality rates, AD prevalence, subjective cognitive decline (SCD) prevalence, and oral health data. Data sources include the Centers for Disease Control and Prevention, scientific literature, and oral health rankings formulated by WalletHub.com and Toothbrush.org. Pearson (r) or Spearman (rs) correlation coefficients were generated and evaluated. AD mortality rates correlate with dental visits (r = − 0.50, p = 0.0003), partial (r = 0.39, p = 0.005) or total (r = 0.44, p = 0.001) edentulism, WalletHub.com (rs = 0.30, p = 0.03) and Toothbrush.org (rs = 0.35, p = 0.01) rankings. AD prevalence correlates with dental visits (r = − 0.30, p = 0.03), partial (r = 0.55, p = 0.00003) or total (r = 0.46, p = 0.0009) edentulism, prevalence of any (r = 0.38, p = 0.006) or severe-stage (r = 0.46, p = 0.0009) PdD, and WalletHub.com (rs = 0.38, p = 0.006) rankings. SCD prevalence in adults aged ≥ 45 years correlates with dental visits (r = − 0.69, p < 0.00001), partial (r = 0.33, p = 0.02) or total (r = 0.37, p = 0.008) edentulism, prevalence of any (r = 0.53, p = 0.0001) or severe-stage (r = 0.57, p = 0.00002) PdD, WalletHub.com (rs = 0.53, p = 0.00008) and Toothbrush.org (rs = 0.60, p < 0.00001) rankings. State metrics indicative of compromised oral health correlate with AD mortality rates, AD prevalence and SCD prevalence.
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Affiliation(s)
- Rana X Scherer
- University of Central Florida, The Burnett Honors College, 12778 Aquarius Agora Drive, Orlando, FL, 32816-1800, USA
| | - Warren J Scherer
- St. Luke's Cataract & Laser Institute, 43309 U.S. Highway 19 N., Tarpon Springs, FL, 34689, USA.
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Handsley-Davis M, Jamieson L, Kapellas K, Hedges J, Weyrich LS. The role of the oral microbiota in chronic non-communicable disease and its relevance to the Indigenous health gap in Australia. BMC Oral Health 2020; 20:327. [PMID: 33198712 PMCID: PMC7670664 DOI: 10.1186/s12903-020-01308-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 10/31/2020] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Aboriginal Australians and Torres Strait Islanders (hereafter respectfully referred to as Indigenous Australians) experience disproportionately poor health and low life expectancy compared to non-Indigenous Australians. Poor oral health is a critical, but understudied, contributor to this health gap. A considerable body of evidence links poor oral health to increased risks of other chronic non-communicable conditions, such as diabetes, cardiovascular disease, chronic kidney disease, and poor emotional wellbeing. MAIN: The oral microbiota is indisputably associated with several oral diseases that disproportionately affect Indigenous Australians. Furthermore, a growing literature suggests direct and indirect links between the oral microbiota and systemic chronic non-communicable diseases that underpin much of the Indigenous health gap in Australia. Recent research indicates that oral microbial communities are shaped by a combination of cultural and lifestyle factors and are inherited from caregivers to children. Systematic differences in oral microbiota diversity and composition have been identified between Indigenous and non-Indigenous individuals in Australia and elsewhere, suggesting that microbiota-related diseases may be distinct in Indigenous Australians. CONCLUSION: Oral microbiota research involving Indigenous Australians is a promising new area that could benefit Indigenous communities in numerous ways. These potential benefits include: (1) ensuring equity and access for Indigenous Australians in microbiota-related therapies; (2) opportunities for knowledge-sharing and collaborative research between scientists and Indigenous communities; and (3) using knowledge about the oral microbiota and chronic disease to help close the gaps in Indigenous oral and systemic health.
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Affiliation(s)
- Matilda Handsley-Davis
- Department of Molecular and Cellular Biology, University of Adelaide, Adelaide, SA, Australia.
| | - Lisa Jamieson
- Australian Research Centre for Population Oral Health (ARCPOH), University of Adelaide, Adelaide, SA, Australia
| | - Kostas Kapellas
- Australian Research Centre for Population Oral Health (ARCPOH), University of Adelaide, Adelaide, SA, Australia
| | - Joanne Hedges
- Australian Research Centre for Population Oral Health (ARCPOH), University of Adelaide, Adelaide, SA, Australia
| | - Laura S Weyrich
- Department of Molecular and Cellular Biology, University of Adelaide, Adelaide, SA, Australia.
- Department of Anthropology and Huck Institutes of Life Sciences, The Pennsylvania State University, University Park, PA, USA.
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34
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Ryder MI. Porphyromonas gingivalis and Alzheimer disease: Recent findings and potential therapies. J Periodontol 2020; 91 Suppl 1:S45-S49. [PMID: 32533852 PMCID: PMC7689719 DOI: 10.1002/jper.20-0104] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 04/06/2020] [Accepted: 04/19/2020] [Indexed: 12/12/2022]
Abstract
Epidemiological studies have identified an association between periodontitis and Alzheimer disease (AD); however, the nature of this association has been unclear. Recent work suggests that brain colonization by the periodontal pathogen Porphyromonas gingivalis may link these two inflammatory and degenerative conditions. Evidence of P. gingivalis infiltration has been detected in autopsy specimens from the brains of people with AD and in cerebrospinal fluid of individuals diagnosed with AD. Gingipains, a class of P. gingivalis proteases, are found in association with neurons, tau tangles, and beta-amyloid in specimens from the brains of individuals with AD. The brains of mice orally infected with P. gingivalis show evidence of P. gingivalis infiltration, along with various neuropathological hallmarks of AD. Oral administration of gingipain inhibitors to mice with established brain infections decreases the abundance of P. gingivalis DNA in brain and mitigates the neurotoxic effects of P. gingivalis infection. Thus, gingipain inhibition could provide a potential approach to the treatment of both periodontitis and AD.
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Affiliation(s)
- Mark I Ryder
- Division of Periodontology, Department of Orofacial Sciences School of Dentistry, University of California, San Francisco, CA
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