scholarly journals Preferential dipeptide incorporation of Porphyromonas gingivalis mediated by proton-dependent oligopeptide transporter (Pot)

2020 ◽  
Author(s):  
Yuko Ohara-Nemoto ◽  
Mohammad Tanvir Sarwar ◽  
Yu Shimoyama ◽  
Takeshi Kobayakawa ◽  
Takayuki K Nemoto
Keyword(s):  
Porphyromonas Gingivalis ◽  
Systemic Diseases ◽  
Bacterial Cells ◽  
Wild Type ◽  
Oligopeptide Transporter ◽  
Potential Therapeutic Target ◽  
Metabolic Analysis ◽  
Dipeptidyl Peptidases ◽  
Dipeptide Uptake ◽  
Cellular Components

Abstract Multiple dipeptidyl-peptidases (DPPs) are present in the periplasmic space of Porphyromonas gingivalis, an asaccharolytic periodontopathic bacterium. Dipeptides produced by DPPs are presumed to be transported into the bacterial cells and metabolized to generate energy and cellular components. The present study aimed to identify a transporter responsible for dipeptide uptake in the bacterium. A real-time metabolic analysis demonstrated that P. gingivalis preferentially incorporated Gly-Xaa dipeptides, and then, single amino acids, tripeptides, and longer oligopeptides to lesser extents. Heterologous expression of the P. gingivalis serine/threonine transporter (SstT) (PGN_1460), oligopeptide transporter (Opt) (PGN_1518), and proton-dependent oligopeptide transporter (Pot) (PGN_0135) genes demonstrated that Escherichia coli expressing Pot exclusively incorporated Gly-Gly, while SstT managed Ser uptake and Opt was responsible for Gly-Gly-Gly uptake. Dipeptide uptake was significantly decreased in a P. gingivalis Δpot strain and further suppressed in a Δpot-Δopt double-deficient strain. In addition, the growth of the Δpot strain was markedly attenuated and the Δpot-Δopt strain scarcely grew, whereas the ΔsstT strain grew well almost like wild type. Consequently, these results demonstrate that predominant uptake of dipeptide in P. gingivalis is mostly managed by POT. We thus propose that Pot is a potential therapeutic target of periodontal disease and P. gingivalis-related systemic diseases.

scholarly journals Kgp and RgpB, but Not RgpA, Are Important for Porphyromonas gingivalis Virulence in the Murine Periodontitis Model

2007 ◽  
Vol 75 (3) ◽  
pp. 1436-1442 ◽  
Author(s):  
Rishi D. Pathirana ◽  
Neil M. O'Brien-Simpson ◽  
Gail C. Brammar ◽  
Nada Slakeski ◽  
Eric C. Reynolds
Keyword(s):  
Bone Loss ◽  
Porphyromonas Gingivalis ◽  
Alveolar Bone ◽  
Alveolar Bone Loss ◽  
Enzyme Linked Immunosorbent Assay ◽  
Bacterial Cells ◽  
Wild Type ◽  
Isogenic Mutant ◽  
Specific Immunoglobulin ◽  
Isogenic Mutants

ABSTRACT The contributions of three proteinase genes (rgpA, rgpB, and kgp) to the virulence of Porphyromonas gingivalis W50 were investigated in the murine periodontitis model. Mice were orally inoculated with eight doses (1 × 1010 cells per dose) of rgpA, rgpB, kgp, rgpA rgpB, or rgpA rgpB kgp isogenic mutants, and the level of alveolar bone loss, immune response induced, and number of bacterial cells per half maxilla were compared with those of animals inoculated with wild-type P. gingivalis. The kgp, rgpB, rgpA rgpB, and rgpA rgpB kgp isogenic mutants induced significantly (P < 0.05) less bone loss than the rgpA isogenic mutant and the wild type did, and the virulence of the rgpA isogenic mutant and the wild type were not significantly different. Mice inoculated with the wild type or the rgpA isogenic mutant exhibited significantly (P < 0.01) more P. gingivalis cells per half maxilla than mice inoculated with rgpB, kgp, rgpA rgpB, and rgpA rgpB kgp isogenic mutants or nonchallenged mice did, as determined using real-time PCR. A significant positive correlation was found between the number of P. gingivalis cells detected per half maxilla and the amount of alveolar bone loss induced. Enzyme-linked immunosorbent assay results showed that each isogenic mutant and the wild type induced a predominant P. gingivalis antigen-specific immunoglobulin G3 (IgG3) response. Furthermore, the kgp and rgpA rgpB kgp isogenic mutants induced significantly (P < 0.05) lower IgG3 antibody responses than the responses induced by the wild type or the rgpA, rgpB, and rgpA rgpB isogenic mutants. The results suggest that the order in which the proteinases contribute to the virulence of P. gingivalis in the murine periodontitis model is Kgp ≥ RgpB ≫ RgpA.

scholarly journals Anchoring and length regulation of Porphyromonas gingivalis Mfa1 fimbriae by the downstream gene product Mfa2

Microbiology ◽  
2009 ◽  
Vol 155 (10) ◽  
pp. 3333-3347 ◽  
Author(s):  
Yoshiaki Hasegawa ◽  
Jun Iwami ◽  
Keiko Sato ◽  
Yoonsuk Park ◽  
Kiyoshi Nishikawa ◽  
...  
Keyword(s):  
Cell Surface ◽  
Gene Product ◽  
Porphyromonas Gingivalis ◽  
Double Labelling ◽  
Bacterial Cells ◽  
Filament Length ◽  
Wild Type ◽  
Length Regulation ◽  
Parental Phenotype ◽  
In Trans

Porphyromonas gingivalis, a causative agent of periodontitis, has at least two types of thin, single-stranded fimbriae, termed FimA and Mfa1 (according to the names of major subunits), which can be discriminated by filament length and by the size of their major fimbrilin subunits. FimA fimbriae are long filaments that are easily detached from cells, whereas Mfa1 fimbriae are short filaments that are tightly bound to cells. However, a P. gingivalis ATCC 33277-derived mutant deficient in mfa2, a gene downstream of mfa1, produced long filaments (10 times longer than those of the parent), easily detached from the cell surface, similar to FimA fimbriae. Longer Mfa1 fimbriae contributed to stronger autoaggregation of bacterial cells. Complementation of the mutant with the wild-type mfa2 allele in trans restored the parental phenotype. Mfa2 is present in the outer membrane of P. gingivalis, but does not co-purify with the Mfa1 fimbriae. However, co-immunoprecipitation demonstrated that Mfa2 and Mfa1 are associated with each other in whole P. gingivalis cells. Furthermore, immunogold microscopy, including double labelling, confirmed that Mfa2 was located on the cell surface and likely associated with Mfa1 fimbriae. Mfa2 may therefore play a role as an anchor for the Mfa1 fimbriae and also as a regulator of Mfa1 filament length. Two additional downstream genes (pgn0289 and pgn0290) are co-transcribed with mfa1 (pgn0287) and mfa2 (pgn0288), and proteins derived from pgn0289, pgn0290 and pgn0291 appear to be accessory fimbrial components.

Wild-type IDH2 protects nuclear DNA from oxidative damage and is a potential therapeutic target in colorectal cancer

Oncogene ◽  
2021 ◽  
Author(s):  
Shuang Qiao ◽  
Wenhua Lu ◽  
Christophe Glorieux ◽  
Jiangjiang Li ◽  
Peiting Zeng ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Oxidative Damage ◽  
Therapeutic Target ◽  
Nuclear Dna ◽  
Wild Type ◽  
Potential Therapeutic Target

scholarly journals Abrogation of Neuraminidase Reduces Biofilm Formation, Capsule Biosynthesis, and Virulence of Porphyromonas gingivalis

2011 ◽  
Vol 80 (1) ◽  
pp. 3-13 ◽  
Author(s):  
Chen Li ◽  
Kurniyati ◽  
Bo Hu ◽  
Jiang Bian ◽  
Jianlan Sun ◽  
...  
Keyword(s):  
Porphyromonas Gingivalis ◽  
Biofilm Formation ◽  
Adult Population ◽  
Transcriptional Analysis ◽  
Wild Type ◽  
Content Type ◽  
Multiple Organs ◽  
Biochemical Analyses

ABSTRACTThe oral bacteriumPorphyromonas gingivalisis a key etiological agent of human periodontitis, a prevalent chronic disease that affects up to 80% of the adult population worldwide.P. gingivalisexhibits neuraminidase activity. However, the enzyme responsible for this activity, its biochemical features, and its role in the physiology and virulence ofP. gingivalisremain elusive. In this report, we found thatP. gingivalisencodes a neuraminidase, PG0352 (SiaPg). Transcriptional analysis showed thatPG0352is monocistronic and is regulated by a sigma70-like promoter. Biochemical analyses demonstrated that SiaPgis an exo-α-neuraminidase that cleaves glycosidic-linked sialic acids. Cryoelectron microscopy and tomography analyses revealed that thePG0352deletion mutant (ΔPG352) failed to produce an intact capsule layer. Compared to the wild type,in vitrostudies showed that ΔPG352 formed less biofilm and was less resistant to killing by the host complement.In vivostudies showed that while the wild type caused a spreading type of infection that affected multiple organs and all infected mice were killed, ΔPG352 only caused localized infection and all animals survived. Taken together, these results demonstrate that SiaPgis an important virulence factor that contributes to the biofilm formation, capsule biosynthesis, and pathogenicity ofP. gingivalis, and it can potentially serve as a new target for developing therapeutic agents againstP. gingivalisinfection.

scholarly journals The kfrA gene is the first in a tricistronic operon required for survival of IncP-1 plasmid R751

Microbiology ◽  
2006 ◽  
Vol 152 (6) ◽  
pp. 1621-1637 ◽  
Author(s):  
Malgorzata Adamczyk ◽  
Patrycja Dolowy ◽  
Michal Jonczyk ◽  
Christopher M. Thomas ◽  
Grazyna Jagura-Burdzy
Keyword(s):  
Coiled Coil ◽  
Broad Host Range ◽  
Gram Negative Bacteria ◽  
Bacterial Cells ◽  
Wild Type ◽  
C Terminus ◽  
Low Copy Number ◽  
And Control ◽  
Broad Host Range Plasmids

The kfrA gene of the IncP-1 broad-host-range plasmids is the best-studied member of a growing gene family that shows strong linkage to the minimal replicon of many low-copy-number plasmids. KfrA is a DNA binding protein with a long, alpha-helical, coiled-coil tail. Studying IncP-1β plasmid R751, evidence is presented that kfrA and its downstream genes upf54.8 and upf54.4 were organized in a tricistronic operon (renamed here kfrA kfrB kfrC), expressed from autoregulated kfrAp, that was also repressed by KorA and KorB. KfrA, KfrB and KfrC interacted and may have formed a multi-protein complex. Inactivation of either kfrA or kfrB in R751 resulted in long-term accumulation of plasmid-negative bacteria, whereas wild-type R751 itself persisted without selection. Immunofluorescence studies showed that KfrAR751 formed plasmid-associated foci, and deletion of the C terminus of KfrA caused plasmid R751ΔC 2 kfrA foci to disperse and mislocalize. Thus, the KfrABC complex may be an important component in the organization and control of the plasmid clusters that seem to form the segregating unit in bacterial cells. The studied operon is therefore part of the set of functions needed for R751 to function as an efficient vehicle for maintenance and spread of genes in Gram-negative bacteria.

scholarly journals Autophagy-Lysosomal Pathway as Potential Therapeutic Target in Parkinson’s Disease

Cells ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3547
Author(s):  
Srinivasa Reddy Bonam ◽  
Christine Tranchant ◽  
Sylviane Muller
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Quality Control ◽  
Cell Survival ◽  
Control Systems ◽  
Therapeutic Strategies ◽  
Cell Type ◽  
Potential Therapeutic Target ◽  
Cellular Components

Cellular quality control systems have gained much attention in recent decades. Among these, autophagy is a natural self-preservation mechanism that continuously eliminates toxic cellular components and acts as an anti-ageing process. It is vital for cell survival and to preserve homeostasis. Several cell-type-dependent canonical or non-canonical autophagy pathways have been reported showing varying degrees of selectivity with regard to the substrates targeted. Here, we provide an updated review of the autophagy machinery and discuss the role of various forms of autophagy in neurodegenerative diseases, with a particular focus on Parkinson’s disease. We describe recent findings that have led to the proposal of therapeutic strategies targeting autophagy to alter the course of Parkinson’s disease progression.

scholarly journals Low-Power Red and Infrared Laser Effects on Cells Deficient in DNA Repair

2019 ◽  
Vol 10 (3) ◽  
pp. 157-162
Author(s):  
Lucas Kiyoshi da Fonseca Iwahara ◽  
Flavia de Paoli ◽  
Adenilson de Souza da Fonseca
Keyword(s):  
Escherichia Coli ◽  
Dna Repair ◽  
Low Power ◽  
Cell Viability ◽  
Bacterial Cells ◽  
Wild Type ◽  
Low Level ◽  
Affect Cell Viability ◽  
Study Results ◽  
Emission Mode

Introduction: Low-level lasers are successfully used to prevent and treat diseases in soft oral and bone tissues, particularly diseases in oral cavity caused by chemotherapy and radiotherapy in oncology. However, controversy exists as to whether these lasers induce molecular side effects, mainly on DNA. The aim of this work was to assess the effects of low-power lasers on mutant Escherichia coli cells in DNA repair. Methods: Escherichia coli wild type cultures as well as those lacking recombination DNA repair (recA- ) and la SOS responses (lexA- ) irradiated with lasers at different energy densities, powers, and emission modes for cell viability and morphology assessment were used in this study. Results: Laser irradiation: (i) did not affect cell viability of non-mutant and lexA- cells but decreased viability in recA- cultures; (ii) altered morphology of wild type and lexA, depending on the energy density, power, emission mode, and wavelength. Conclusion: Results show that low-level lasers have lethal effects on both recombination DNA repair and SOS response bacterial cells but do not induce morphological modifications in these cells.

scholarly journals Neuroprotective effect of ZnT3 knockout on subarachnoid hemorrhage

2018 ◽  
Vol 9 (1) ◽  
pp. 26-32
Author(s):  
Duo Chen ◽  
Zhao-Bo Nie ◽  
Zhi-Hong Chi ◽  
Zhan-You Wang ◽  
Xiang-Tai Wei ◽  
...  
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Neuroprotective Effect ◽  
Neuronal Injury ◽  
Early Brain Injury ◽  
Vital Role ◽  
Tunel Staining ◽  
Wild Type ◽  
Potential Therapeutic Target ◽  
Neurological Score ◽  
Hematoxylin Eosin

Abstract Background The pathophysiology of early brain injury (EBI) after subarachnoid hemorrhage (SAH) is poorly understood. The present study evaluates the influence of zinc transporter 3 (ZnT3) knockout and the depletion of vesicular zinc on EBI. Methodology SAH was induced in ZnT3 KO mice by internal carotid artery perforation. The changes in behavior were recorded at 24 hours after SAH. Hematoxylin-eosin, Nissl and TUNEL staining were performed to evaluate neuronal apoptosis. Data from mice with a score of 8-12 in intracerebral bleeding (i.e. moderate SAH), were analyzed. Results The degree of SAH-induced neuronal injury was directly correlated to the amount of blood lost, which in turn was negatively reflected in their behavior. The Wild Type (WT)-SAH group behaved poorly when compared to the knockout (KO)-SAH mice and their poor neurological score was accompanied by an increase in the number of apoptotic neurons. Conversely, the improvement of behavior in the KO-SAH group was associated with a marked reduction in apoptotic neurons. Conclusions These results suggest that ZnT3 knockout may have played a vital role in the attenuation of neuronal injury after SAH and that ZnT3 may prove to be a potential therapeutic target for neuroprotection in EBI.

Polypeptide synthesis in cell cycle mutants of fission yeast

1981 ◽  
Vol 51 (1) ◽  
pp. 203-217
Author(s):  
D.P. Dickinson
Keyword(s):  
Cell Cycle ◽  
Dna Synthesis ◽  
Fission Yeast ◽  
Gel Electrophoresis ◽  
Mutant Cell ◽  
Wild Type ◽  
Unsuccessful Attempt ◽  
Dependent Sequence ◽  
Polypeptide Synthesis ◽  
Cellular Components

The cell cycle of a growing cel is characterized by 3 main periodic events: DNA synthesis mitosis and cell division. These events generally lie in a dependent sequence, in which one event cannot occur unless preceding events have occurred. The existence of dependent sequences of events raises the possibility that at least some of the gene products involved in the events are synthesized in a dependent sequence parallel to the observable events. To test this hypothesis, the patterns of polypeptide synthesis were investigated in 2 types of cell cycle mutant of the fission yeast Schizosaccharomyces pombe: temperature-sensitive cell cycle (ts cdc) mutants. which become blocked in cell cycle progress at the restrictive temperature; and wee I mutants, which are defective in size control over nuclear division, and which divide at a small size. Cells of mutants and wild-type cells were labelled with [35S[sulphate under conditions designed to maximize any differences between the labelling patterns of wild-type and mutant cell polypeptides. The polypeptides were then separated by O'Farrell 2-dimensional gel electrophoresis, and the patterns compared. Although both types of mutation affect cell cycle control, and cause a considerable alteration in the relative proportions of cellular components, an examination of over 700 polypeptides detected on gels revealed no qualitative differences between wild-type and mutant cell polypeptides. These results suggest that a large majority of the more abundant polypeptides in the growing cell are synthesized independently of cell cycle controls directly related to DNA synthesis and division, and that the synthesis of these polypeptides can occur in the absence of normal progress through the cell cycle. Dependent sequences of gene expression do not appear to make a significant contribution to total polypeptide synthesis during the cell cycle, or to the occurrence of periodic cell cycle events such as mitosis. It is suggested that such cell cycle events may result largely through the reorganization of existing cellular components, rather than by the synthesis of new ones. An unsuccessful attempt was made to detect the wee I gene product on gels by surveying a range of mutants for changes in an individual spot. The limitations of gel electrophoresis for this type of survey, and other cell cycle experiments, are discussed.

scholarly journals Porphyromonas gingivalis Impairs Oral Epithelial Barrier through Targeting GRHL2

2019 ◽  
Vol 98 (10) ◽  
pp. 1150-1158 ◽  
Author(s):  
W. Chen ◽  
A. Alshaikh ◽  
S. Kim ◽  
J. Kim ◽  
C. Chun ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Oral Mucosa ◽  
Porphyromonas Gingivalis ◽  
Oral Bacteria ◽  
Conditional Knockout ◽  
Epithelial Barrier ◽  
Wild Type ◽  
Oral Epithelial ◽  
Junction Proteins

Oral mucosa provides the first line of defense against a diverse array of environmental and microbial irritants by forming the barrier of epithelial cells interconnected by multiprotein tight junctions (TJ), adherens junctions, desmosomes, and gap junction complexes. Grainyhead-like 2 (GRHL2), an epithelial-specific transcription factor, may play a role in the formation of the mucosal epithelial barrier, as it regulates the expression of the junction proteins. The current study investigated the role of GRHL2 in the Porphyromonas gingivalis ( Pg)–induced impairment of epithelial barrier functions. Exposure of human oral keratinocytes (HOK-16B and OKF6 cells) to Pg or Pg-derived lipopolysaccharides ( Pg LPSs) led to rapid loss of endogenous GRHL2 and the junction proteins (e.g., zonula occludens, E-cadherin, claudins, and occludin). GRHL2 directly regulated the expression levels of the junction proteins and the epithelial permeability for small molecules (e.g., dextrans and Pg bacteria). To explore the functional role of GRHL2 in oral mucosal barrier, we used a Grhl2 conditional knockout (KO) mouse model, which allows for epithelial tissue-specific Grhl2 KO in an inducible manner. Grhl2 KO impaired the expression of the junction proteins at the junctional epithelium and increased the alveolar bone loss in the ligature-induced periodontitis model. Fluorescence in situ hybridization revealed increased epithelial penetration of oral bacteria in Grhl2 KO mice compared with the wild-type mice. Also, blood loadings of oral bacteria (e.g., Bacteroides, Bacillus, Firmicutes, β- proteobacteria, and Spirochetes) were significantly elevated in Grhl2 KO mice compared to the wild-type littermates. These data indicate that Pg bacteria may enhance paracellular penetration through oral mucosa in part by targeting the expression of GRHL2 in the oral epithelial cells, which then impairs the epithelial barrier by inhibition of junction protein expression, resulting in increased alveolar tissue destruction and systemic bacteremia.

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