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Śmiga M, Olczak T. Porphyromonas endodontalis HmuY differentially participates in heme acquisition compared to the Porphyromonas gingivalis and Tannerella forsythia hemophore-like proteins. Front Cell Infect Microbiol 2024; 14:1421018. [PMID: 38938884 PMCID: PMC11208336 DOI: 10.3389/fcimb.2024.1421018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2024] [Accepted: 06/03/2024] [Indexed: 06/29/2024] Open
Abstract
Introduction Porphyromonas gingivalis and Porphyromonas endodontalis belong to the Bacteroidota phylum. Both species inhabit the oral cavity and can be associated with periodontal diseases. To survive, they must uptake heme from the host as an iron and protoporphyrin IX source. Among the best-characterized heme acquisition systems identified in members of the Bacteroidota phylum is the P. gingivalis Hmu system, with a leading role played by the hemophore-like HmuY (HmuYPg) protein. Methods Theoretical analysis of selected HmuY proteins and spectrophotometric methods were employed to determine the heme-binding mode of the P. endodontalis HmuY homolog (HmuYPe) and its ability to sequester heme. Growth phenotype and gene expression analysis of P. endodontalis were employed to reveal the importance of the HmuYPe and Hmu system for this bacterium. Results Unlike in P. gingivalis, where HmuYPg uses two histidines for heme-iron coordination, other known HmuY homologs use two methionines in this process. P. endodontalis HmuYPe is the first characterized representative of the HmuY family that binds heme using a histidine-methionine pair. It allows HmuYPe to sequester heme directly from serum albumin and Tannerella forsythia HmuYTf, the HmuY homolog which uses two methionines for heme-iron coordination. In contrast to HmuYPg, which sequesters heme directly from methemoglobin, HmuYPe may bind heme only after the proteolytic digestion of hemoglobin. Conclusions We hypothesize that differences in components of the Hmu system and structure-based properties of HmuY proteins may evolved allowing different adaptations of Porphyromonas species to the changing host environment. This may add to the superior virulence potential of P. gingivalis over other members of the Bacteroidota phylum.
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Han M, Zhu C, Tang S, Liang J, Li D, Guo Y, Zuraini Z, Si Q, Jiang Q. The effects of a polystyrene nanoplastic on the immune response and gut microbiota of Eriocheir sinensis and its post-recovery state. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2023; 262:106644. [PMID: 37549485 DOI: 10.1016/j.aquatox.2023.106644] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 07/14/2023] [Accepted: 07/28/2023] [Indexed: 08/09/2023]
Abstract
Although there is increasing concern about the toxicity of nanoplastics, the effects of nanoplastic exposure and subsequent recovery on immune responses, as well as antioxidant responses and gut microbiota, in crustaceans are rarely reported. In this study, the nonspecific immunity and antioxidant defense of Eriocheir sinensis were evaluated after acute exposure to various concentrations (0, 2.5, 5, 10 and 20 mg/L) of 75-nm polystyrene nanoplastics (PS-NPs) for 48 h, as well as after 7 days of recovery from the nanoplastic environment. The results showed that, after 48 h of exposure, nanoplastics were observed in the gills, hepatopancreas and gut. However, no nanoplastics were found in the gut after 7 days of recovery. Under nanoplastic-induced stress, Hc, Relish, proPO, and LITAF mRNA levels increased in the gills and hepatopancreas for 48 h. Expression of the myd88, Hc, Relish and proPO genes decreased in the gills during the 7-day recovery period. Exposure to nanoplastics for 48 h and recovery for 7 days significantly decreased the activities of lysozyme (LZM) alkaline phosphatase (AKP), total superoxide dismutase (SOD) and phenoloxidase (POD) and, glutathione peroxidase (GPX) in the hepatopancreas. Meanwhile, the relative abundance of pathogens exposed to 10 mg/L nanoplastics for 48 h increased at the species level, and these pathogens decreased significantly in the 7-day recovery period. These results suggested that exposure to nanoplastics for 48 h affected the activities of immune system enzymes and expression of immune-related genes in Eriocheir sinensis and altered the diversity and composition of their gut microbiota. E. sinensis could not recover from damage to the hepatopancreas within a 7-day recovery period. The results of this study provided insight into the effects of nanoplastics on crustaceans and it filled a gap in research on crustacean recovery after exposure to nanoplastics.
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Affiliation(s)
- Mingming Han
- Biology Program, Centre for Marine and Coastal Studies, Universiti Sains Malaysia, Minden, Penang 11800, Malaysia
| | - Chenxi Zhu
- Freshwater Fisheries Research Institute of Jiangsu Province, 79 Chating East Street, Nanjing 210017, China
| | - Shengkai Tang
- Freshwater Fisheries Research Institute of Jiangsu Province, 79 Chating East Street, Nanjing 210017, China
| | - Ji Liang
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Daming Li
- Freshwater Fisheries Research Institute of Jiangsu Province, 79 Chating East Street, Nanjing 210017, China
| | - YanXia Guo
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, China
| | - Zakaria Zuraini
- Biology Program, Centre for Marine and Coastal Studies, Universiti Sains Malaysia, Minden, Penang 11800, Malaysia
| | - Qin Si
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, China
| | - Qichen Jiang
- Freshwater Fisheries Research Institute of Jiangsu Province, 79 Chating East Street, Nanjing 210017, China.
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Sasaki Y, Shoji M, Sueyoshi T, Shibata S, Matsuo T, Yukitake H, Wolf M, Naito M. A conditional gene expression system in Porphyromonas gingivalis for study of the secretion mechanisms of lipoproteins and T9SS cargo proteins. Mol Oral Microbiol 2023. [PMID: 37339018 DOI: 10.1111/omi.12426] [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: 01/26/2023] [Revised: 05/16/2023] [Accepted: 06/04/2023] [Indexed: 06/22/2023]
Abstract
The Gram-negative anaerobe, Porphyromonas gingivalis, is known to be a pathogen associated with chronic periodontitis. P. gingivalis possesses virulence factors such as fimbriae and gingipain proteinases. Fimbrial proteins are secreted to the cell surface as lipoproteins. In contrast, gingipain proteinases are secreted into the bacterial cell surface via the type IX secretion system (T9SS). The transport mechanisms of lipoproteins and T9SS cargo proteins are entirely different and remain unknown. Therefore, using the Tet-on system developed for the genus Bacteroides, we newly created a conditional gene expression system in P. gingivalis. We succeeded in establishing conditional expression of nanoluciferase and its derivatives for lipoprotein export, of FimA for a representative of lipoprotein export, and of T9SS cargo proteins such as Hbp35 and PorA for representatives of type 9 protein export. Using this system, we showed that the lipoprotein export signal, which has recently been found in other species in the phylum Bacteroidota, is also functional in FimA, and that a proton motive force inhibitor can affect type 9 protein export. Collectively, our conditional protein expression method is useful for screening inhibitors of virulence factors, and may be used to investigate the role of proteins essential to bacterial survival in vivo.
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Affiliation(s)
- Yuko Sasaki
- Department of Microbiology and Oral Infection, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
| | - Mikio Shoji
- Department of Microbiology and Oral Infection, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
| | - Takayuki Sueyoshi
- Department of Microbiology and Oral Infection, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
| | - Satoshi Shibata
- Molecular Cryo-Electron Microscopy Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
- Faculty of Medicine, Division of Bacteriology, Department of Microbiology & Immunology, Tottori University, Tottori, Japan
| | - Takehiro Matsuo
- Department of Microbiology and Oral Infection, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
| | - Hideharu Yukitake
- Department of Microbiology and Oral Infection, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
| | - Matthias Wolf
- Molecular Cryo-Electron Microscopy Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Mariko Naito
- Department of Microbiology and Oral Infection, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
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Shimoyama Y, Sasaki D, Ohara-Nemoto Y, Nemoto TK, Nakasato M, Sasaki M, Ishikawa T. Immunoelectron Microscopic Analysis of Dipeptidyl-Peptidases and Dipeptide Transporter Involved in Nutrient Acquisition in Porphyromonas gingivalis. Curr Microbiol 2023; 80:106. [PMID: 36797528 DOI: 10.1007/s00284-023-03212-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 02/02/2023] [Indexed: 02/18/2023]
Abstract
Porphyromonas gingivalis is an asaccharolytic, Gram-negative, anaerobic bacterium representing a keystone pathogen in chronic periodontitis. The bacterium's energy production depends on the metabolism of amino acids, which are predominantly incorporated as dipeptides via the proton-dependent oligopeptide transporter (Pot). In this study, the localization of dipeptidyl-peptidases (DPPs) and Pot was investigated for the first time in P. gingivalis using immunoelectron microscopy with specific antibodies for the bacterial molecules and gold-conjugated secondary antibodies on ultrathin sections. High-temperature protein G and hemin-binding protein 35 were used as controls, and the cytoplasmic localization of the former and outer membrane localization of the latter were confirmed. P. gingivalis DPP4, DPP5, DPP7, and DPP11, which are considered sufficient for complete dipeptide production, were detected in the periplasmic space. In contrast, DPP3 was localized in the cytoplasmic space in accord with the absence of a signal sequence. The inner membrane localization of Pot was confirmed. Thus, spatial integration of the nutrient acquisition system exists in P. gingivalis, in which where dipeptides are produced in the periplasmic space by DPPs and readily transported across the inner membrane via Pot.
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Affiliation(s)
- Yu Shimoyama
- Division of Molecular Microbiology, Department of Microbiology, Iwate Medical University, 1-1-1 Idai-Dori, Yahaba-Cho, Shiwa-Gun, Iwate, 028-3694, Japan
| | - Daisuke Sasaki
- Division of Periodontology, Department of Conservative Dentistry, Iwate Medical University School of Dentistry, 1-3-27 Chuo-Dori, Morioka, Iwate, 020-8505, Japan.
| | - Yuko Ohara-Nemoto
- Division of Molecular Microbiology, Department of Microbiology, Iwate Medical University, 1-1-1 Idai-Dori, Yahaba-Cho, Shiwa-Gun, Iwate, 028-3694, Japan
- Department of Pediatric Dentistry, Course of Medical and Dental Sciences, Nagasaki University Graduate School of Biomedical Sciences, Sakamoto 1-7-1, Nagasaki, 852-8588, Japan
| | - Takayuki K Nemoto
- Division of Molecular Microbiology, Department of Microbiology, Iwate Medical University, 1-1-1 Idai-Dori, Yahaba-Cho, Shiwa-Gun, Iwate, 028-3694, Japan
- Department of Pediatric Dentistry, Course of Medical and Dental Sciences, Nagasaki University Graduate School of Biomedical Sciences, Sakamoto 1-7-1, Nagasaki, 852-8588, Japan
| | - Manami Nakasato
- Division of Periodontology, Department of Conservative Dentistry, Iwate Medical University School of Dentistry, 1-3-27 Chuo-Dori, Morioka, Iwate, 020-8505, Japan
| | - Minoru Sasaki
- Division of Molecular Microbiology, Department of Microbiology, Iwate Medical University, 1-1-1 Idai-Dori, Yahaba-Cho, Shiwa-Gun, Iwate, 028-3694, Japan
| | - Taichi Ishikawa
- Division of Molecular Microbiology, Department of Microbiology, Iwate Medical University, 1-1-1 Idai-Dori, Yahaba-Cho, Shiwa-Gun, Iwate, 028-3694, Japan
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Nemoto TK, Ohara Nemoto Y. Dipeptidyl-peptidases: Key enzymes producing entry forms of extracellular proteins in asaccharolytic periodontopathic bacterium Porphyromonas gingivalis. Mol Oral Microbiol 2020; 36:145-156. [PMID: 33006264 PMCID: PMC8048996 DOI: 10.1111/omi.12317] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 09/17/2020] [Accepted: 09/24/2020] [Indexed: 02/06/2023]
Abstract
Porphyromonas gingivalis, a pathogen of chronic periodontitis, is an asaccharolytic microorganism that solely utilizes nutritional amino acids as its energy source and cellular constituents. The bacterium is considered to incorporate proteinaceous nutrients mainly as dipeptides, thus exopeptidases that produce dipeptides from polypeptides are critical for survival and proliferation. We present here an overview of dipeptide production by P. gingivalis mediated by dipeptidyl-peptidases (DPPs), e.g., DPP4, DPP5, DPP7, and DPP11, serine exopeptidases localized in periplasm, which release dipeptides from the N-terminus of polypeptides. Additionally, two other exopeptidases, acylpeptidyl-oligopeptidase (AOP) and prolyl tripeptidyl-peptidase A (PTP-A), which liberate N-terminal acylated di-/tri-peptides and tripeptides with Pro at the third position, respectively, provide polypeptides in an acceptable form for DPPs. Hence, a large fraction of dipeptides is produced from nutritional polypeptides by DPPs with differential specificities in combination with AOP and PTP-A. The resultant dipeptides are then incorporated across the inner membrane mainly via a proton-dependent oligopeptide transporter (POT), a member of the major facilitator superfamily. Recent studies also indicate that DPP4 and DPP7 directly link between periodontal and systemic diseases, such as type 2 diabetes mellitus and coagulation abnormality, respectively. Therefore, these dipeptide-producing and incorporation molecules are considered to be potent targets for prevention and treatment of periodontal and related systemic diseases.
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Affiliation(s)
- Takayuki K Nemoto
- Department of Oral Molecular Biology, Course of Medical and Dental Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Yuko Ohara Nemoto
- Department of Oral Molecular Biology, Course of Medical and Dental Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
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Rai AK, Panda M, Das AK, Rahman T, Das R, Das K, Sarma A, Kataki AC, Chattopadhyay I. Dysbiosis of salivary microbiome and cytokines influence oral squamous cell carcinoma through inflammation. Arch Microbiol 2020; 203:137-152. [PMID: 32783067 DOI: 10.1007/s00203-020-02011-w] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/23/2020] [Accepted: 08/03/2020] [Indexed: 01/10/2023]
Abstract
Advanced combinatorial treatments of surgery, chemotherapy, and radiotherapy do not have any effect on the enhancement of a 5-year survival rate of oral squamous cell carcinoma (OSCC). The discovery of early diagnostic non-invasive biomarkers is required to improve the survival rate of OSCC patients. Recently, it has been reported that oral microbiome has a significant contribution to the development of OSCC. Oral microbiome induces inflammatory response through the production of cytokines and chemokines that enhances tumor cell proliferation and survival. The study aims to develop saliva-based oral microbiome and cytokine biomarker panel that screen OSCC patients based on the level of the microbiome and cytokine differences. We compared the oral microbiome signatures and cytokine level in the saliva of OSCC patients and healthy individuals by 16S rRNA gene sequencing targeting the V3/V4 region using the MiSeq platform and cytokine assay, respectively. The higher abundance of Prevotella melaninogenica, Fusobacterium sp., Veillonella parvula, Porphyromonas endodontalis, Prevotella pallens, Dialister, Streptococcus anginosus, Prevotella nigrescens, Campylobacter ureolyticus, Prevotella nanceiensis, Peptostreptococcus anaerobius and significant elevation of IL-8, IL-6, TNF-α, GM-CSF, and IFN-γ in the saliva of patients having OSCC. Oncobacteria such as S. anginosus, V. parvula, P. endodontalis, and P. anaerobius may contribute to the development of OSCC by increasing inflammation via increased expression of inflammatory cytokines such as IL-6, IL-8, TNF-α, IFN-γ, and GM-CSF. These oncobacteria and cytokines panels could potentially be used as a non-invasive biomarker in clinical practice for more efficient screening and early detection of OSCC patients.
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Affiliation(s)
- Avdhesh Kumar Rai
- Dr. B. Borooah Cancer Institute, A. K. Azad Road, Gopinath Nagar, Guwahati, Assam, 16, India
| | - Madhusmita Panda
- Department of Life Sciences, School of Life Sciences, Central University of Tamil Nadu, Thiruvarur, 610101, India
| | - Ashok Kumar Das
- Dr. B. Borooah Cancer Institute, A. K. Azad Road, Gopinath Nagar, Guwahati, Assam, 16, India
| | - Tashnin Rahman
- Dr. B. Borooah Cancer Institute, A. K. Azad Road, Gopinath Nagar, Guwahati, Assam, 16, India
| | - Rajjyoti Das
- Dr. B. Borooah Cancer Institute, A. K. Azad Road, Gopinath Nagar, Guwahati, Assam, 16, India
| | - Kishore Das
- Dr. B. Borooah Cancer Institute, A. K. Azad Road, Gopinath Nagar, Guwahati, Assam, 16, India
| | - Anupam Sarma
- Dr. B. Borooah Cancer Institute, A. K. Azad Road, Gopinath Nagar, Guwahati, Assam, 16, India
| | - Amal Ch Kataki
- Dr. B. Borooah Cancer Institute, A. K. Azad Road, Gopinath Nagar, Guwahati, Assam, 16, India
| | - Indranil Chattopadhyay
- Department of Life Sciences, School of Life Sciences, Central University of Tamil Nadu, Thiruvarur, 610101, India.
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Nemoto TK, Bezerra GA, Ono T, Nishimata H, Fujiwara T, Ohara-Nemoto Y. Identification of a new subtype of dipeptidyl peptidase 11 and a third group of the S46-family members specifically present in the genus Bacteroides. Biochimie 2018; 147:25-35. [PMID: 29080830 DOI: 10.1016/j.biochi.2017.10.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 10/22/2017] [Indexed: 10/18/2022]
Abstract
Peptidase family S46 consists of two types of dipeptidyl-peptidases (DPPs), DPP7 and DPP11, which liberate dipeptides from the N-termini of polypeptides along with the penultimate hydrophobic and acidic residues, respectively. Their specificities are primarily defined by a single amino acid residue, Gly673 in DPP7 and Arg673 in DPP11 (numbering for Porphyromonas gingivalis DPP11). Bacterial species in the phyla Proteobacteria and Bacteroidetes generally possess one gene for each, while Bacteroides species exceptionally possess three genes, one gene as DPP7 and two genes as DPP11, annotated based on the full-length similarities. In the present study, we aimed to characterize the above-mentioned Bacteroides S46 DPPs. A recombinant protein of the putative DPP11 gene BF9343_2924 from Bacteroides fragilis harboring Gly673 exhibited DPP7 activity by hydrolyzing Leu-Leu-4-methylcoumaryl-7-amide (MCA). Another gene, BF9343_2925, as well as the Bacteroides vulgatus gene (BVU_2252) with Arg673 was confirmed to encode DPP11. These results demonstrated that classification of S46 peptidase is enforceable by the S1 essential residues. Bacteroides DPP11 showed a decreased level of activity towards the substrates, especially with P1-position Glu. Findings of 3D structural modeling indicated three potential amino acid substitutions responsible for the reduction, one of which, Asn650Thr substitution, actually recovered the hydrolyzing activity of Leu-Glu-MCA. On the other hand, the gene currently annotated as DPP7 carrying Gly673 from B. fragilis (BF9343_0130) and Bacteroides ovatus (Bovatus_03382) did not hydrolyze any of the examined substrates. The existence of a phylogenic branch of these putative Bacteroides DPP7 genes classified by the C-terminal conserved region (Ser571-Leu700) strongly suggests that Bacteroides species expresses a DPP with an unknown property. In conclusion, the genus Bacteroides exceptionally expresses three S46-family members; authentic DPP7, a new subtype of DPP11 with substantially reduced specificity for Glu, and a third group of S46 family members.
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Affiliation(s)
- Takayuki K Nemoto
- Department of Oral Molecular Biology, Course of Medical and Dental Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8588, Japan.
| | - Gustavo Arruda Bezerra
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Vienna Biocenter, Vienna Biocenter Campus 5, 1030 Vienna, Austria.
| | - Toshio Ono
- Department of Oral Molecular Biology, Course of Medical and Dental Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8588, Japan.
| | - Haruka Nishimata
- Department of Pediatric Dentistry, Course of Medical and Dental Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8588, Japan.
| | - Taku Fujiwara
- Department of Pediatric Dentistry, Course of Medical and Dental Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8588, Japan.
| | - Yuko Ohara-Nemoto
- Department of Oral Molecular Biology, Course of Medical and Dental Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8588, Japan.
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Shimoyama Y, Ohara-Nemoto Y, Kimura M, Nemoto TK, Tanaka M, Kimura S. Dominant prevalence of Porphyromonas gingivalis fimA types I and IV in healthy Japanese children. J Dent Sci 2017; 12:213-219. [PMID: 30895053 PMCID: PMC6400010 DOI: 10.1016/j.jds.2017.03.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 12/26/2016] [Indexed: 11/17/2022] Open
Abstract
Background/purpose Porphyromonas gingivalis is a major causative agent of chronic periodontitis, whilst circumstances for acquisition of the bacterium remain to be elucidated. To examine prevalence of the bacterium harboring distinct fimA types in dental plaque of children, we established PCR procedures that are applicable for specimens with limited amounts. By this method, all six fimA types including type I and Ib were directly identified, and prevalence of fimA types and their frequency of guardian-child transmission in Japanese children were assessed. Materials and methods Genomic DNA was purified from dental plaque specimens of 132 periodontally healthy children (2-12 years old, 4.8 ± 0.2 years) and 19 mothers of resultant P. gingivalis-positive child subjects. PCR-based fimA genotyping was performed, and untypeable strains in the first PCR analysis were determined by a nested PCR. Results P. gingivalis was found in 15.2% of the subjects (2-10 years old, 5.1 ± 0.6 years), and the most prevalent types were I and IV (37.0% each), followed by Ib and III (11.1% each), and then II (7.4%). Seven (35.0%) of the 20 P. gingivalis-positive subjects had combined colonization of type I with other fimA types. In most cases, bacterial prevalence and fimA types in the children were distinct from those of their mothers, indicating that its maternal transmission was not significant. Conclusion These results suggest that colonization of non-disease-associated fimA types I and IV P. gingivalis to the oral cavity initiates from early childhood without showing any periodontal inflammation.
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Affiliation(s)
- Yu Shimoyama
- Division of Molecular Microbiology, Iwate Medical University Graduate School of Dentistry, Yahaba-cho, Iwate, Japan
| | - Yuko Ohara-Nemoto
- Department of Oral Molecular Biology, Course of Medical and Dental Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
- Corresponding author. Department of Oral Molecular Biology, Course of Medical and Dental Sciences, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki 852-8588, Japan. Fax: +81 95 819 7642.
| | - Misumi Kimura
- Division of Molecular Microbiology, Iwate Medical University Graduate School of Dentistry, Yahaba-cho, Iwate, Japan
- Division of Paediatric Dentistry, Iwate Medical University Graduate School of Dentistry, Morioka, Iwate, Japan
| | - Takayuki K. Nemoto
- Department of Oral Molecular Biology, Course of Medical and Dental Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Mitsuro Tanaka
- Division of Paediatric Dentistry, Iwate Medical University Graduate School of Dentistry, Morioka, Iwate, Japan
| | - Shigenobu Kimura
- Division of Molecular Microbiology, Iwate Medical University Graduate School of Dentistry, Yahaba-cho, Iwate, Japan
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Nemoto TK, Ohara-Nemoto Y. Exopeptidases and gingipains in Porphyromonas gingivalis as prerequisites for its amino acid metabolism. JAPANESE DENTAL SCIENCE REVIEW 2016; 52:22-29. [PMID: 28408952 PMCID: PMC5382784 DOI: 10.1016/j.jdsr.2015.08.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 08/20/2015] [Accepted: 08/20/2015] [Indexed: 01/22/2023] Open
Abstract
Porphyromonas gingivalis, an asaccharolytic bacterium, utilizes amino acids as energy and carbon sources. Since amino acids are incorporated into the bacterial cells mainly as di- and tri-peptides, exopeptidases including dipeptidyl-peptidase (DPP) and tripeptidyl-peptidase are considered to be prerequisite components for their metabolism. We recently discovered DPP11, DPP5, and acylpeptidyl oligopeptidase in addition to previously reported DPP4, DPP7, and prolyl tripeptidyl peptidase A. DPP11 is a novel enzyme specific for acidic P1 residues (Asp and Glu) and distributed ubiquitously in eubacteria, while DPP5 is preferential for the hydrophobic P1 residue and the first entity identified in prokaryotes. Recently, acylpeptidyl oligopeptidase with a preference for hydrophobic P1 residues was found to release N-terminally blocked di- and tri-peptides. Furthermore, we also demonstrated that gingipains R and K contribute to P1-basic dipeptide production. These observations implicate that most, if not all, combinations of di- and tri-peptides are produced from extracellular oligopeptides even with an N-terminal modification. Here, we review P. gingivalis exopeptidases mainly in regard to their enzymatic characteristics. These exopeptidases with various substrate specificities benefit P. gingivalis for obtaining energy and carbon sources from the nutritionally limited subgingival environment.
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Affiliation(s)
- Takayuki K. Nemoto
- Department of Oral Molecular Biology, Course of Medical and Dental Sciences, Nagasaki University Graduate School of Biomedical Sciences, Japan
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