scholarly journals PORPHYROMONAS GINGIVALIS E PERIODONTITE CRÔNICA - AVANÇOS RECENTES

Author(s):  
Victor Hugo Rocha Leon ◽  
Ellen Karla Nobre dos Santos-Lima ◽  
Ana Carla Montino Pimentel ◽  
Patricia Mares de Miranda ◽  
Paulo Cirino De Carvalho Filho ◽  
...  

Periodontal disease is multifactorial and it affects the tissues surrounding the teeth. Its etiology includes microrganisms as Porphyromonas gingivalis, Tannerella forsythia and Aggregatibacter actinomycetemcomitans. This work aimed to discuss the role of Porphyromonas gingivalis in chronic periodontitis. The electronic bases PubMed, BIREME and SciELO were used to search for historical aspects and studies published between 2000 and 2015, using the following descriptors in Portuguese and English: “Chronic periodontitis, Porphyromonas gingivalis” and “Virulence factors”. 205 articles were found and 24 were included. Records on periodontal diseases from the early civilization to the present day were found. Its prevalence in the world’s population remains high and several studies report the pathogenesis of the disease. P. gingivalis is able to induce humoral and cellular response in infected individuals. Studies on its escape mechanisms and virulence factors report tissue breakdown consequent to immuno-inflammatory exacerbated response in the host which may evolve into edentulism. Studies of the immune response to P. gingivalis suggest its role in perpetuation of the inflammatory state by interfering with cytokines production and cell death mechanisms in the host’s cells, resulting in tissue destruction. The current knowledge about mechanisms of infection and virulence factors of P. gingivalis indicate its role as a key component in chronic periodontitis.

2020 ◽  
Vol 11 ◽  
Author(s):  
Chiaki Yamada ◽  
Juliet Akkaoui ◽  
Anny Ho ◽  
Carolina Duarte ◽  
Richard Deth ◽  
...  

BackgroundAmong different types of sphingolipids produced by human cells, the possible engagement of ceramide species in the pathogenesis of Alzheimer’s disease (AD) has attracted recent attention. While ceramides are primarily generated by de novo synthesis in mammalian cells, only a limited number of bacterial species, produce ceramides, including phosphoglycerol dihydroceramide (PGDHC) that is produced by the key periodontal pathogen Porphyromonas gingivalis. Emerging evidence indicates that virulence factors produced by P. gingivalis, such as lipopolysaccharide and gingipain, may be engaged in the initiation and/or progression of AD. However, the potential role of PGDHC in the pathogenesis of AD remains unknown. Therefore, the aim of this study was to evaluate the influence of PGDHC on hallmark findings in AD.Material and MethodsCHO-7WD10 and SH-SY-5Y cells were exposed to PGDHC and lipopolysaccharide (LPS) isolated from P. gingivalis. Soluble Aβ42 peptide, amyloid precursor protein (APP), phosphorylated tau and senescence-associated secretory phenotype (SASP) factors were quantified using ELISA and Western blot assays. ResultsOur results indicate that P. gingivalis (Pg)-derived PGDHC, but not Pg-LPS, upregulated secretion of soluble Aβ42 peptide and expression of APP in CHO-7WD10 cells. Furthermore, hyperphosphorylation of tau protein was observed in SH-SY-5Y cells in response to PGDHC lipid. In contrast, Pg-LPS had little, or no significant effect on the tau phosphorylation induced in SH-SY-5Y cells. However, both PGDHC and Pg-LPS contributed to the senescence of SH-SY5Y cells as indicated by the production of senescence-associated secretory phenotype (SASP) markers, including beta-galactosidase, cathepsin B (CtsB), and pro-inflammatory cytokines TNF-α, and IL-6. Additionally, PGDHC diminished expression of the senescence-protection marker sirtuin-1 in SH-SY-5Y cells.ConclusionsAltogether, our results indicate that P. gingivalis-derived PGDHC ceramide promotes amyloidogenesis and hyperphosphorylation, as well as the production of SASP factors. Thus, PGDHC may represent a novel class of bacterial-derived virulence factors for AD associated with periodontitis.


2019 ◽  
Vol 119 (04) ◽  
pp. 534-541 ◽  
Author(s):  
Selin Gencer ◽  
Emiel van der Vorst ◽  
Maria Aslani ◽  
Christian Weber ◽  
Yvonne Döring ◽  
...  

AbstractInflammation has been well recognized as one of the main drivers of atherosclerosis development and therefore cardiovascular diseases (CVDs). It has been shown that several chemokines, small 8 to 12 kDa cytokines with chemotactic properties, play a crucial role in the pathophysiology of atherosclerosis. Chemokines classically mediate their effects by binding to G-protein-coupled receptors called chemokine receptors. In addition, chemokines can also bind to atypical chemokine receptors (ACKRs). ACKRs fail to induce G-protein-dependent signalling pathways and thus subsequent cellular response, but instead are able to internalize, scavenge or transport chemokines. In this review, we will give an overview of the current knowledge about the involvement of ACKR1–4 in CVDs and especially in atherosclerosis development. In the recent years, several studies have highlighted the importance of ACKRs in CVDs, although there are still several controversies and unexplored aspects that have to be further elucidated. A better understanding of the precise role of these atypical receptors may pave the way towards novel and improved therapeutic strategies.


2020 ◽  
Vol 23 (1) ◽  
pp. 6-12
Author(s):  
Tienneke Riana Septiwidyati ◽  
Endang Winiati Bachtiar

Porphyromonas gingivalis is an anaerobic Gram-negative oral bacterium involved in the pathogenesis of periodontitis. Periodontitis is an infection that is characterized by damage to the supporting tissues of the teeth so that it can cause tooth loss if not given treatment. P. gingivalis locally can invade periodontal tissue and avoid host defense mechanisms. This bacterium has virulence factors which can cause deregulation of innate immune responses and inflammation in the host. The role of P. gingivalis virulence factors such as capsules, fimbriae, lipopolysaccharides, and gingipain in the pathogenesis of periodontitis will be discussed in this paper.


Author(s):  
Ridhima Seth

Objective: The study reveals the effects of green tea and cocoa on the growth of Porphyromonas gingivalis, a common periodontal pathogen. The studies at the cellular level enhance our understanding of the periodontal diseases. Hence, improving our knowledge of the antioxidant activity against periodontal pathogens will help to develop effective periodontal therapeutics. Design: The methodology of study involves isolation of Porphyromonas gingivalis colonies from salivary samples and then studying the effect of green tea and cocoa on the growth of colonies on blood agar plates by studying the zones of inhibition around these extracts in different solvents. Result: The activity of green tea and cocoa extract against Porphyromonas gingivalis on Blood agar was studied by a suitable method by measuring the diameter of zones of inhibition. The maximum diameter of zone of inhibition of 16 mm was observed with green tea extracts in an aqueous medium while no zones were observed with cocoa extracts in an aqueous medium. Conclusion: Our study concluded that green tea has inhibitory activity against Porphyromonas gingivalis, which is one of the major pathogens involved in chronic periodontitis. Therefore, the study provided an insight of the possibility to overcome bacterial resistance to antibiotics and to augment the action of antibiotics by providing green tea supplements in chronic periodontitis patients. Thus, the development of potent inhibitors against P. Gingivalis can provide new therapeutic approaches to treat periodontal diseases and as a result, the related systemic diseases.


2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Ioannis P. Nezis

Autophagy is an evolutionarily conserved process of cellular self-eating and is a major pathway for degradation of cytoplasmic material by the lysosomal machinery. Autophagy functions as a cellular response in nutrient starvation, but it is also associated with the removal of protein aggregates and damaged organelles and therefore plays an important role in the quality control of proteins and organelles. Although it was initially believed that autophagy occurs randomly in the cell, during the last years, there is growing evidence that sequestration and degradation of cytoplasmic material by autophagy can be selective. Given the important role of autophagy and selective autophagy in several disease-related processes such as neurodegeneration, infections, and tumorigenesis, it is important to understand the molecular mechanisms of selective autophagy, especially at the organismal level.Drosophilais an excellent genetically modifiable model organism exhibiting high conservation in the autophagic machinery. However, the regulation and mechanisms of selective autophagy inDrosophilahave been largely unexplored. In this paper, I will present an overview of the current knowledge about selective autophagy inDrosophila.


2006 ◽  
Vol 85 (5) ◽  
pp. 392-403 ◽  
Author(s):  
E. Andrian ◽  
D. Grenier ◽  
M. Rouabhia

Emerging data on the consequences of the interactions between invasive oral bacteria and host cells have provided new insights into the pathogenesis of periodontal disease. Indeed, modulation of the mucosal epithelial barrier by pathogenic bacteria appears to be a critical step in the initiation and progression of periodontal disease. Periodontopathogens such as Porphyromonas gingivalis have developed different strategies to perturb the structural and functional integrity of the gingival epithelium. P. gingivalis adheres to, invades, and replicates within human epithelial cells. Adhesion of P. gingivalis to host cells is multimodal and involves the interaction of bacterial cell-surface adhesins with receptors expressed on the surfaces of epithelial cells. Internalization of P. gingivalis within host cells is rapid and requires both bacterial contact-dependent components and host-induced signaling pathways. P. gingivalis also subverts host responses to bacterial challenges by inactivating immune cells and molecules and by activating host processes leading to tissue destruction. The adaptive ability of these pathogens that allows them to survive within host cells and degrade periodontal tissue constituents may contribute to the initiation and progression of periodontitis. In this paper, we review current knowledge on the molecular cross-talk between P. gingivalis and gingival epithelial cells in the development of periodontitis.


2020 ◽  
Vol 16 (1) ◽  
pp. 70-74
Author(s):  
Viktoriya Miroshnichenko ◽  
Alena Kokoreva ◽  
Anastasiya Safonova

Subject. Despite the constant efforts of practicing physicians and scientists, the prevalence proportion of inflammatory and destructive periodontal diseases in the world is not subsiding. Previously scientists have examined several different theories on the development of pathological conditions in periodontal tissues, ranging problems from the neurotrophic theory of occurrence to the effect of occlusion injury on periodontal tissues. Theories dealing with the influence of specific and non-specific bacterial plaque have also been studied. None of the theories has become reasonable and single valued. It is believed that the mechanism of the development of the disease is complex, autoimmune, damaging primarily collagen, elastic fibers of the capillary endothelium, gingival ligament and bone tissue. Over the past decade, it has been proven that inflammation in periodontal tissues is initiated and proceeds in response to the introduction of pathogenic bacteria. However, it can be said that not all patients develop an inflammatory response to bacterial invasion. The second important factor in the development and progression of the inflammatory-destructive process is the immune response of a particular individual. Scientists have noted the influence of the non-microbial factor and have come to the conclusion that in the surrounding tissues of the inflamed area there are not only enzymes secreted by bacteria, but also leukocyte proteinases, which in turn are mediators of the tissue destruction. Purpose ― to examine the role of leukocyte proteinases in the pathogenesis of inflammatory periodontal diseases. Methodology. The number of indigenous and foreign literature sources dealing with the study of the role of leukocyte proteinases in the development and maintenance of a destructive inflammatory process has been reviewed by us. Conclusion. The role of the aggressive destructive effect of leukocyte proteinases on periodontal tissues has been analyzed. Leukocyte proteinases are mediators of progressive destruction of connective tissue and can be used as markers to assess the severity of the course and predict the development of the inflammatory process in periodontal tissues.


2021 ◽  
Vol 66 (7) ◽  
pp. 422-427
Author(s):  
N. V. Davidovich ◽  
N. V. Solovieva ◽  
A. S. Galieva ◽  
S. Yu. Lepeshkin ◽  
E. N. Bashilova ◽  
...  

The system of antimicrobial peptides (AMP) is one of the most ancient mechanisms of the macroorganism resistance to infectious pathogens invasion. The aim of the study was to determine the role of the antimicrobial peptides system and periodontal pathogenic markers in the development and progression of inflammatory periodontal diseases. Gingival pocket washes (91 samples in total) for the research were received from patients with inflammatory periodontal diseases (chronic periodontitis and gingivitis) and intact periodontium. Using ELISA, the content of antimicrobial peptides was determined: human alpha-defensin (HNP 1-3), beta-defensin (HBD 1-3) and cathelicidin (LL-37). Periodontal pathogenic markers were isolated during RT-PCR. The study revealed differences in AMP concentrations by groups: level of HBD 2 in patients with chronic periodontitis was 1,36 times higher than those in the group of patients with chronic gingivitis (p=0,023) and 2,39 times higher than those in the control group (p<0,001), the content of HNP 1-3 in the group of patients with chronic periodontitis was reduced by 1,23 times compared with the indicators of the group of patients with gingivitis (p=0,045) and by 1,97 times compared with the indicators of the control group (p<0,001). The frequency of detection of periodontal pathogenic bacteria genes was 88,0% in patients with periodontitis, 76,92% in patients with gingivitis and 33,3% in the group with intact periodontium. HBD 2 content moderately correlated with the definition of P. gingivalis (r=0,612; p=0,022), T. forsythensis (r= 0,434; p=0,015), A. actinomycetemcomitans (r=0,483; p=0,006), a moderate negative correlation was detected between the content of HNP 1-3 and the release of periodontal pathogens in associations (P. gingivalis with T. forsythensis and T. denticola) (r=-0,388; p=0,031) in the group of patients with chronic periodontitis. Thus, the revealed relationships and correlations indicate shifts in the processes of reparative regeneration of the oral cavity and the regulation of local immunity in response to microbial invasion.


Author(s):  
Hiba Redha Hussain ◽  
Ahlam Kadhum Al-Yasseen

This study aims to investigate the correlation between some virulence factors and biofilm production among Porphyromonas gingivalis associated with periodontitis. One hundred and two sub gingival swabs have been collected from patients suffering from acute and chronic periodontitis admitted to Specialty Dental center in the Holy city of Najaf and specialized clinics in the Faculty of Dentistry of the University of Kufa from both sexes during the period from September 2017 to January 2018. A total of 34 isolates (28.43%) were identified as P. gingivalis by amplification of 16S rRNA using PCR technique. luxS, lux pro and lux down genes were investigated and the results of PCR showed that none of the strains were possess luxS, 3 strains of P. gingivalis were possess lux pro and 2 strains of P. gingivalis were possess lux dwn. Only 10 strains of P. gingivalis were selected for detection of some virulence factors. The results showed that all strains were unable to produce biofilm with variant abilities of bacterial strains for autoaggregation have been observed (decrease in O.D of bacterial growth after 1 hr. of incubation), and one strain gave +ve results for hemagglutination.


2020 ◽  
Vol 9 (12) ◽  
pp. 4004
Author(s):  
Yuhei Takayanagi ◽  
Takeshi Kikuchi ◽  
Yoshiaki Hasegawa ◽  
Yoshikazu Naiki ◽  
Hisashi Goto ◽  
...  

Porphyromonas gingivalis Mfa1 fimbriae are thought to act as adhesion factors and to direct periodontal tissue destruction but their immunomodulatory actions are poorly understood. Here, we investigated the effect of Mfa1 stimulation on the immune and metabolic mechanisms of gingival fibroblasts from periodontal connective tissue. We also determined the role of Toll-like receptor (TLR) 2 and TLR4 in Mfa1 recognition. Mfa1 increased the expression of genes encoding chemokine (C-X-C motif) ligand (CXCL) 1, CXCL3, intercellular adhesion molecule (ICAM) 1 and Selectin endothelium (E) in gingival fibroblasts, but did not have a significant effect on genes that regulate metabolism. Mfa1-stimulated up-regulation of genes was significantly suppressed in Tlr4 siRNA-transfected cells compared with that in control siRNA-transfected cells, which indicates that recognition by TLR4 is essential for immunomodulation by Mfa1. Additionally, suppression of Tlr2 expression partially attenuated the stimulatory effect of Mfa1. Overall, these results help explain the involvement of P. gingivalis Mfa1 fimbriae in the progression of periodontal disease.


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