scholarly journals Nonulosonic acids contribute to the pathogenicity of the oral bacterium Tannerella forsythia

2019 ◽  
Vol 9 (2) ◽  
pp. 20180064 ◽  
Author(s):  
Susanne Bloch ◽  
Markus B. Tomek ◽  
Valentin Friedrich ◽  
Paul Messner ◽  
Christina Schäffer
Keyword(s):  
Cell Surface ◽  
Current Knowledge ◽  
Cell Envelope ◽  
Treatment Strategies ◽  
Periodontal Pathogen ◽  
Tannerella Forsythia ◽  
Oral Bacterium ◽  
Complex Protein ◽  
Unique Cell ◽  
Systemic Health

Periodontitis is a polymicrobial, biofilm-caused, inflammatory disease affecting the tooth-supporting tissues. It is not only the leading cause of tooth loss worldwide, but can also impact systemic health. The development of effective treatment strategies is hampered by the complicated disease pathogenesis which is best described by a polymicrobial synergy and dysbiosis model. This model classifies the Gram-negative anaerobe Tannerella forsythia as a periodontal pathogen, making it a prime candidate for interference with the disease. Tannerella forsythia employs a protein O -glycosylation system that enables high-density display of nonulosonic acids via the bacterium's two-dimensional crystalline cell surface layer. Nonulosonic acids are sialic acid-like sugars which are well known for their pivotal biological roles. This review summarizes the current knowledge of T. forsythia' s unique cell envelope with a focus on composition, biosynthesis and functional implications of the cell surface O -glycan. We have obtained evidence that glycobiology affects the bacterium's immunogenicity and capability to establish itself in the polymicrobial oral biofilm. Analysis of the genomes of different T. forsythia isolates revealed that complex protein O -glycosylation involving nonulosonic acids is a hallmark of pathogenic T. forsythia strains and, thus, constitutes a valuable target for the design of novel anti-infective strategies to combat periodontitis.

scholarly journals Adsorption of Components of the Plasma Kinin-Forming System on the Surface ofPorphyromonas gingivalisInvolves Gingipains as the Major Docking Platforms

2010 ◽  
Vol 79 (2) ◽  
pp. 797-805 ◽  
Author(s):  
Maria Rapala-Kozik ◽  
Grazyna Bras ◽  
Barbara Chruscicka ◽  
Justyna Karkowska-Kuleta ◽  
Aneta Sroka ◽  
...  
Keyword(s):  
Cell Surface ◽  
Cell Envelope ◽  
Periodontal Pathogen ◽  
Kinin System ◽  
Relative Significance ◽  
Proteolytic Activation ◽  
Bacterial Surface ◽  
Enhanced Production ◽  
Direct Binding ◽  
Kallikrein Kinin System

ABSTRACTEnhanced production of proinflammatory bradykinin-related peptides, the kinins, has been suggested to contribute to the pathogenesis of periodontitis, a common inflammatory disease of human gingival tissues. In this report, we describe a plausible mechanism of activation of the kinin-generating system, also known as the contact system or kininogen-kallikrein-kinin system, by the adsorption of its plasma-derived components such as high-molecular-mass kininogen (HK), prekallikrein (PK), and Hageman factor (FXII) to the cell surface of periodontal pathogenPorphyromonas gingivalis. The adsorption characteristics of mutant strains deficient in selected proteins of the cell envelope suggested that the surface-associated cysteine proteinases, gingipains, bearing hemagglutinin/adhesin domains (RgpA and Kgp) serve as the major platforms for HK and FXII adhesion. These interactions were confirmed by direct binding tests using microplate-immobilized gingipains and biotinylated contact factors. Other bacterial cell surface components such as fimbriae and lipopolysaccharide were also found to contribute to the binding of contact factors, particularly PK. Analysis of kinin release in plasma upon contact withP. gingivalisshowed that the bacterial surface-dependent mechanism is complementary to the previously described kinin generation system dependent on HK and PK proteolytic activation by the gingipains. We also found that severalP. gingivalisclinical isolates differed in the relative significance of these two mechanisms of kinin production. Taken together, these data show the importance of this specific type of bacterial surface-host homeostatic system interaction in periodontal infections.

scholarly journals Current Insights into Immunology and Novel Therapeutics of Atopic Dermatitis

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1392
Author(s):  
Hidaya A. Kader ◽  
Muhammad Azeem ◽  
Suhib A. Jwayed ◽  
Aaesha Al-Shehhi ◽  
Attia Tabassum ◽  
...  
Keyword(s):  
Atopic Dermatitis ◽  
Skin Diseases ◽  
Current Knowledge ◽  
Treatment Strategies ◽  
Developed Countries ◽  
Food Allergies ◽  
Th2 Response ◽  
Therapeutic Outcomes ◽  
Environmental Agents ◽  
Novel Treatment Strategies

Atopic dermatitis (AD) is one of the most prevalent inflammatory disease among non-fatal skin diseases, affecting up to one fifth of the population in developed countries. AD is characterized by recurrent pruritic and localized eczema with seasonal fluctuations. AD initializes the phenomenon of atopic march, during which infant AD patients are predisposed to progressive secondary allergies such as allergic rhinitis, asthma, and food allergies. The pathophysiology of AD is complex; onset of the disease is caused by several factors, including strong genetic predisposition, disrupted epidermal barrier, and immune dysregulation. AD was initially characterized by defects in the innate immune system and a vigorous skewed adaptive Th2 response to environmental agents; there are compelling evidences that the disorder involves multiple immune pathways. Symptomatic palliative treatment is the only strategy to manage the disease and restore skin integrity. Researchers are trying to more precisely define the contribution of different AD genotypes and elucidate the role of various immune axes. In this review, we have summarized the current knowledge about the roles of innate and adaptive immune responsive cells in AD. In addition, current and novel treatment strategies for the management of AD are comprehensively described, including some ongoing clinical trials and promising therapeutic agents. This information will provide an asset towards identifying personalized targets for better therapeutic outcomes.

scholarly journals Diversity of GPI-anchored fungal adhesins

2020 ◽  
Vol 401 (12) ◽  
pp. 1389-1405
Author(s):  
Lars-Oliver Essen ◽  
Marian Samuel Vogt ◽  
Hans-Ulrich Mösch
Keyword(s):  
Cell Wall ◽  
Cell Surface ◽  
Bioinformatics Analysis ◽  
Current Knowledge ◽  
Sequence Similarity ◽  
Growth Forms ◽  
Similarity Networks ◽  
Fungal Adhesins ◽  
Sequence Similarity Networks ◽  
Successful Colonization

AbstractSelective adhesion of fungal cells to one another and to foreign surfaces is fundamental for the development of multicellular growth forms and the successful colonization of substrates and host organisms. Accordingly, fungi possess diverse cell wall-associated adhesins, mostly large glycoproteins, which present N-terminal adhesion domains at the cell surface for ligand recognition and binding. In order to function as robust adhesins, these glycoproteins must be covalently linkedto the cell wall via C-terminal glycosylphosphatidylinositol (GPI) anchors by transglycosylation. In this review, we summarize the current knowledge on the structural and functional diversity of so far characterized protein families of adhesion domains and set it into a broad context by an in-depth bioinformatics analysis using sequence similarity networks. In addition, we discuss possible mechanisms for the membrane-to-cell wall transfer of fungal adhesins by membrane-anchored Dfg5 transglycosidases.

Exploring the Contribution of Mycobacteria Characteristics in Their Interaction with Human Macrophages

2013 ◽  
Vol 19 (5) ◽  
pp. 1159-1169 ◽  
Author(s):  
Carla Silva ◽  
Joao Perdigao ◽  
Elsa Alverca ◽  
António P. Alves de Matos ◽  
Patricia A. Carvalho ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Cell Envelope ◽  
Treatment Strategies ◽  
Human Monocyte ◽  
Selective Advantage ◽  
Multidrug Resistant ◽  
Structural Features ◽  
Major Health Problem ◽  
Transmission Electron ◽  
Mdr Tb

AbstractTuberculosis (TB) is a major health problem. The emergence of multidrug resistant (MDR)Mycobacterium tuberculosis(Mtb) isolates confounds treatment strategies. In Portugal, cases of MDR-TB are reported annually with an increased incidence noted in Lisbon. The majority of these MDR-TB cases are due to closely related mycobacteria known collectively as theLisboafamily and Q1 cluster. Genetic determinants linked to drug resistance have been exhaustively studied resulting in the identification of family and cluster specific mutations. Nevertheless, little is known about other factors involved in development of mycobacteria drug resistance. Here, we complement genetic analysis with the study of morphological and structural features of theLisboafamily and Q1 cluster isolates by using scanning and transmission electron microscopy. This analysis allowed the identification of structural differences, such as cell envelope thickness, between Mtb clinical isolates that are correlated with antibiotic resistance. The infection of human monocyte derived macrophages allowed us to document the relative selective advantage of theLisboafamily isolates over other circulating Mtb isolates.

scholarly journals An Investigation Into The Synergistic Relationship Between Lactoferrin And Azithromycin With Particular Reference To Periodontopathic Bacteria

2017 ◽  
Vol 16 (2) ◽  
Author(s):  
Juzaily Husain
Keyword(s):  
Protein Synthesis ◽  
Outer Membrane ◽  
Porphyromonas Gingivalis ◽  
Treatment Strategies ◽  
Antimicrobial Protein ◽  
Tannerella Forsythia ◽  
Iron Depletion ◽  
Test Strips ◽  
Agar Diffusion ◽  
Synergistic Relationship

Introduction: The development of treatment strategies for periodontitis that maximise the effectiveness of antibiotics is highly desirable. Azithromycin is proving to be an effective antibiotic for treatment of refractory periodontitis which works by binding to the outer membrane of Gramnegative bacteria and subsequently inhibits protein synthesis. Lactoferrin is a membrane-active host antimicrobial protein and so the objective of this study was to determine whether the effect of azithromycin (AZM) against example periodontopathogens (Porphyromonas gingivalis and Tannerella forsythia) could be potentiated by lactoferrin. Materials and Methods: Two strains of P. gingivalis and T. forsythia were exposed to lactoferrin (LF; up to 10 mg/ml) and AZM (up to 5 g/ml) for 0 -72 h. The MICs for AZM were established using E-Test strips and by agar diffusion. Susceptibility to LF and LF + AZM was evaluated using diffusion assays, with and without iron depletion. Results: The range of MIC values of AZM for P. gingivalis strains and T. forsythia was 0.16 - 0.63 µg/ml and 0.50 - 0.63 µg/ml, respectively. However, no inhibition was observed with iron saturated lactoferrin at any concentration or under iron depletion conditions nor was any effect observed on the AZM MIC by its presence. Conclusion(s): P. gingivalis and T. forsythia were inhibited by AZM but were not affected by LF and there was no synergism between AZM and LF.

Diagnosis and Treatment of Smoke Inhalation

1995 ◽  
Vol 10 (3) ◽  
pp. 117-127 ◽  
Author(s):  
Basil A. Pruitt ◽  
William G. Cioffi
Keyword(s):  
Current Knowledge ◽  
Treatment Strategies ◽  
Inhalation Injury ◽  
Smoke Inhalation ◽  
Diagnosis And Treatment ◽  
Laboratory Research ◽  
Individualization Of Therapy ◽  
Injured Patients

Inhalation remains the most frequent and serious comorbid event that occurs in thermally injured patients. A thorough understanding of the pathophysiology enables individualization of therapy and appropriate triage of patients. We summarize our current knowledge of the pathophysiology, diagnosis, and treatment of inhalation injury, with a focus on newer treatment strategies that are evolving secondary to laboratory research.

Monogenic Epilepsies: Disease Mechanisms, Clinical Phenotypes, and Targeted Therapies

Neurology ◽  
2021 ◽  
pp. 10.1212/WNL.0000000000012744
Author(s):  
Renzo Guerrini ◽  
Simona Balestrini ◽  
Elaine C. Wirrell ◽  
Matthew C. Walker
Keyword(s):  
Observational Studies ◽  
Current Knowledge ◽  
Functional Characterization ◽  
Treatment Strategies ◽  
Controlled Trials ◽  
Epileptogenic Zone ◽  
Missense Mutations ◽  
Number Of Patients ◽  
Functional Consequences ◽  
Genetic Epilepsies

A monogenic aetiology can be identified in up to 40% of people with severe epilepsy. To address earlier and more appropriate treatment strategies, clinicians are required to know the implications that specific genetic causes might have on pathophysiology, natural history, comorbidities and treatment choices. In this narrative review, we summarise concepts on the genetic epilepsies based on the underlying pathophysiological mechanisms and present the current knowledge on treatment options based on evidence provided by controlled trials or studies with lower classification of evidence. Overall, evidence robust enough to guide antiseizure medication (ASM) choices in genetic epilepsies remains limited to the more frequent conditions for which controlled trials and observational studies have been possible. Most monogenic disorders are very rare and ASM choices for them are still based on inferences drawn from observational studies and early, often anecdotal, experiences with precision therapies. Precision medicine remains applicable to only a narrow number of patients with monogenic epilepsies and may target only part of the actual functional defects. Phenotypic heterogeneity is remarkable, and some genetic mutations activate epileptogenesis through their developmental effects, which may not be reversed postnatally. Other genes seem to have pure functional consequences on excitability, acting through either loss- or gain-of-function effects, and these may have opposite treatment implications. In addition, the functional consequences of missense mutations may be difficult to predict, making precision treatment approaches considerably more complex than estimated by deterministic interpretations. Knowledge of genetic aetiologies can influence the approach to surgical treatment of focal epilepsies. Identification of germline mutations in specific genes contraindicates surgery while mutations in other genes do not. Identification, quantification and functional characterization of specific somatic mutations before surgery using cerebrospinal fluid liquid biopsy or after surgery in brain specimens, will likely be integrated in planning surgical strategies and re-intervention after a first unsuccessful surgery as initial evidence suggests that mutational load may correlate with the epileptogenic zone. Promising future directions include gene manipulation by DNA or mRNA targeting; although most are still far from clinical use, some are in early phase clinical development.

Missing links — epigenetic regulators of the pancreatic cancer–associated inflammation

2021 ◽  
Vol 135 (10) ◽  
pp. 1289-1293
Author(s):  
Gregor Werba ◽  
Tamas A. Gonda
Keyword(s):  
Pancreatic Cancer ◽  
Noncoding Rna ◽  
Current Knowledge ◽  
Treatment Strategies ◽  
Therapeutic Interventions ◽  
Ductal Adenocarcinoma ◽  
Gastrointestinal Cancers ◽  
Novel Treatment ◽  
Epigenetic Regulator ◽  
Novel Treatment Strategies

Abstract Pancreatic ductal adenocarcinoma (PDAC) features a hostile tumor microenvironment (TME) that renders it remarkably resistant to most therapeutic interventions. Consequently, survival remains among the poorest compared with other gastrointestinal cancers. Concerted efforts are underway to decipher the complex PDAC TME, break down barriers to efficacious therapies and identify novel treatment strategies. In the recent Clinical Science, Li and colleagues identify the long noncoding RNA KLHDC7B-DT as a crucial epigenetic regulator of IL-6 transcription in PDAC and illustrate its potent influences on the pancreatic TME. In this commentary, we introduce epigenetics in pancreatic cancer and put the findings by Li et al. in context with current knowledge.

Computer Vision Syndrome among Internet Users

2012 ◽  
pp. 782-798
Author(s):  
Liang Hu ◽  
Fan Lu
Keyword(s):  
Computer Vision ◽  
Current Knowledge ◽  
Treatment Strategies ◽  
Computer Users ◽  
Computer User ◽  
Contributing Factors ◽  
Internet Users ◽  
Computer Vision Syndrome ◽  
Computer Environments

The chapter is intended to introduce Computer Vision Syndrome (CVS), a widely spreading but largely unknown epidemic among professional and ordinary computer users, especially internet users. Dr. Sheedy and Dr. Anshel are two leading researchers in the ergonomics and optometry fields, and CVS has been extensively studied in these fields. The authors have summarized their views about CVS, including five major symptoms of CVS, three key contributing factors of CVS, and basic preventive and treatment strategies. Future researches are needed to continue the advancement of current knowledge regarding computer screens, computer task, and computer environments, and to expand research in diverse computer user populations, especially younger computer users.

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