Role of the RprY Response Regulator in P. gingivalis Community Development and Virulence
In this study we examined cross phosphorylation of RprY on tyrosine residues and its importance for RprY function. We show that RprY reacts with phosphotyrosine antibodies, and a tyrosine (Y) resi due at position 41 is predicted to be solvent accessible. Loss of RprY increased the level of heterotypic community development withStreptococcus gordonii, and the community ‐suppressive function of RprY required Y41. Expression of the Mfa1 fimbrial adhesin was increased in therprY mutant and in the mutant complemented withrprY containing a Y41F mutation. In a microscale thermophoresis assay, recombinant RprY protein bound to t...
Source: Molecular Oral Microbiology - September 15, 2020 Category: Microbiology Authors: Daonan Shen,
John D. Perpich,
Kendall S. Stocke,
Lan Yakoumatos,
Zackary R. Fitzsimonds,
Chengcheng Liu,
Daniel P. Miller,
Richard J. Lamont Tags: ORIGINAL ARTICLE Source Type: research
Inflammatory response of uric acid produced by Porphyromonas gingivalis gingipains
In this study, we demonstrate thatP. gingivalis gingipains play a role in THP ‐1 macrophage uric acid production by increasing the expression and activity of xanthine oxidoreductase. Uric acid sodium salt induces caspase‐1 activation, cell death, and the expression of proinflammatory cytokines, including IL‐1α, IL‐6, and IL‐8, in the human keratinocyte HOK‐16B ce ll line. Our results suggest that gingipain‐induced uric acid can mediate inflammation in periodontal tissue cells. (Source: Molecular Oral Microbiology)
Source: Molecular Oral Microbiology - August 13, 2020 Category: Microbiology Authors: Hye ‐Kyung Jun,
Sun‐Jin An,
Hyun Young Kim,
Bong‐Kyu Choi Tags: ORIGINAL ARTICLE Source Type: research
Deletion of csn2 gene affects acid tolerance and exopolysaccharide synthesis in Streptococcus mutans
In this study, we investigated whethercsn2 deletion would affectS. mutans physiology and virulence gene expression. We used microscopic imaging, acid killing assays, pH drop, biofilm formation and exopolysaccharide (EPS) prodction tests to determine whethercsn2 deletion influencedS. mutans colony morphology, acid tolerance/production and glucan formation abilities. Comparisons were made between qRT ‐PCR data from the UA159 andcsn2 deletion strain to determine the impact ofcsn2 knockout onS. mutans gene expression. The results showed that deletion ofS. mutans csn2 changed its colony morphotype and made it more sensitive t...
Source: Molecular Oral Microbiology - August 13, 2020 Category: Microbiology Authors: Anqi Zhang,
Jiamin Chen,
Tao Gong,
Miao Lu,
Boyu Tang,
Xuedong Zhou,
Yuqing Li Tags: ORIGINAL ARTICLE Source Type: research
Filifactor alocis ‐derived extracellular vesicles inhibit osteogenesis through TLR2 signaling
AbstractFilifactor alocis, an asaccharolytic anaerobic Gram ‐positive rod (AAGPR), is an emerging marker of periodontitis. Severe periodontitis causes destruction of the alveolar bone that supports teeth and can even lead to tooth loss. Based on our previous report thatF. alocis‐derived extracellular vesicles (FA EVs) contain various effector molecules and have immunostimulatory activity, we investigated the effect of FA EVs on osteogenesis using mouse bone‐derived mesenchymal stromal cells (BMSCs). FA EVs dramatically inhibited bone mineralization similarly to whole b acteria and reduced the expression levels of ost...
Source: Molecular Oral Microbiology - July 22, 2020 Category: Microbiology Authors: Min ‐Kyoung Song,
Hyun Young Kim,
Bong‐Kyu Choi,
Hong‐Hee Kim Tags: ORIGINAL ARTICLE Source Type: research
Issue Information
Molecular Oral Microbiology, Volume 35, Issue 4, Page i-iii, August 2020. (Source: Molecular Oral Microbiology)
Source: Molecular Oral Microbiology - July 19, 2020 Category: Microbiology Tags: ISSUE INFORMATION Source Type: research
In vivo and ex vivo actions of a novel P. gingivalis inhibitor on multi ‐species biofilm, inflammatory response and periodontal bone loss
SummaryChronic periodontitis is one of the most common infectious inflammatory diseases worldwide. Current therapeutic options for the disease are only partially and temporarily successful due to periodontal re ‐emergence of pathogens such asPorphyromonas gingivalis, a keystone bacterium in the oral microbial communities, which elicits a dysbiosis between the microbiota and the host. Previously, we reported a peptide inhibitor ofP. gingivalis (SAPP) that specifically targetsP. gingivalis and reduces its virulence potentialin vitro. Here, we show that SAPP can modulate the ability ofP. gingivalis to suppress the host inna...
Source: Molecular Oral Microbiology - June 29, 2020 Category: Microbiology Authors: Meng ‐Hsuan Ho,
Hatice Hasturk,
Daphne F. Young,
Hua Xie Tags: ORIGINAL ARTICLE Source Type: research
Sequence and characterization of shuttle vectors for molecular cloning in Porphyromonas, Bacteroides, and related bacteria
AbstractThere is a lack of shuttle vectors to be needed for investigations into the genetics ofPorphyromonas gingivalis and related species. To better understand the prevalence of candidates for such tools we have examined multiple strains of black pigmented anaerobes (clinical and laboratory isolates) for plasmids. As no plasmids were found inP. gingivalis strains, we have used the pYH420 plasmid, derived fromP. asaccharolytica, as backbone to construct a shuttle vector in combination with pUC19 fromEscherichia coli. Nucleotide sequence determination of the pYH420 plasmid revealed that that it contained a gene with simila...
Source: Molecular Oral Microbiology - June 25, 2020 Category: Microbiology Authors: Kevin R. Jones,
B. Ross Belvin,
Francis L. Macrina,
Janina P. Lewis Tags: ORIGINAL ARTICLE Source Type: research
Proteomic analysis of Fusobacterium nucleatum growth in biofilm versus planktonic state
SummaryFusobacterium nucleatum is isolated from both supra ‐ and sub‐gingival dental biofilms in humans and has been implicated in the aetiology of periodontitis. Also, this bacterium plays an important role in serious infections in other parts of the body. The aim of this investigation was to study the protein differential expression ofF. nucleatum when growing on biofilm, compared to planktonic state, using proteomic analysis by the 2D ‐DIGE™ system. Sixty‐eight proteins were differentially expressed during biofilm growth (1.5‐fold, p<0.05), being 20 down ‐expressed and 31 over‐expressed. The repressed...
Source: Molecular Oral Microbiology - June 17, 2020 Category: Microbiology Authors: Arancha Llama ‐Palacios,
Oksana Potupa,
María C. Sánchez,
Elena Figuero,
David Herrera,
Mariano Sanz Tags: ORIGINAL ARTICLE Source Type: research
Effects of Porphyromonas gingivalis and Fusobacterium nucleatum on inflammasomes and their regulators in H400 cells
ConclusionPg alone increased IL ‐1β by upregulating AIM2, NLRP3 and downregulating POP1.Fn promoted IL ‐1β by increasing AIM2 and downregulating POP1.Pg+ATP with or withoutFn upregulated NLRP3, IL ‐1β by downregulating POP1. Periodontal pathogens may contribute to HNSCC pathogenesis by increasing the IL‐1β response due to inflammasome dysregulation. (Source: Molecular Oral Microbiology)
Source: Molecular Oral Microbiology - June 8, 2020 Category: Microbiology Authors: K übra Aral,
Michael R Milward,
Dhanak Gupta,
Paul R Cooper Tags: ORIGINAL ARTICLE Source Type: research
Aggregatibacter actinomycetemcomitans leukotoxin: From mechanism to targeted anti ‐toxin therapeutics
Aggregatibacter actinomycetemcomitans is a Gram ‐negative bacterium associated with localized aggressive periodontitis, as well as other systemic diseases. Several studies have demonstrated that clinical isolates from diseased patients frequently belong to specific clones ofA. actinomycetemcomitans that produce significantly higher amounts of leukotoxin (LtxA) suggesting that LtxA might play a key role in pathogenicity. In this article, we review the mechanisms by which LtxA interacts with and kills host cells, highlight the remaining open questions, and demonstrate how knowledge of these mechanisms, enable the design of...
Source: Molecular Oral Microbiology - May 4, 2020 Category: Microbiology Authors: Eric Krueger,
Angela C. Brown Tags: REVIEW ARTICLE Source Type: research
Issue Information
Molecular Oral Microbiology, Volume 35, Issue 3, Page i-iv, June 2020. (Source: Molecular Oral Microbiology)
Source: Molecular Oral Microbiology - May 4, 2020 Category: Microbiology Tags: ISSUE INFORMATION Source Type: research
Streptococcus mutans SpxA2 relays the signal of cell envelope stress from LiaR to effectors that maintain cell wall and membrane homeostasis
In this study, the role of thespxA2 transcriptional regulator in these two pathways, and overall cell envelope homeostasis, was examined. Loss ofspxA2 resulted in an increase in the proportion of saturated fatty acids in theS. mutans membrane and altered transcription of several genes involved in the production of these membrane fatty acids, includingfabT andfabM. Furthermore, activity of the F1F0‐ATPase was increased in the ∆spxA2 strain. Transcription ofspxA2 was elevated in the presence of a variety of membrane stressors, and highly dependent on theliaR component of the LiaFSR system, which is known to sense cell en...
Source: Molecular Oral Microbiology - May 4, 2020 Category: Microbiology Authors: Jonathon L. Baker,
Sarah Saputo,
Roberta C. Faustoferri,
Robert G. Quivey Tags: ORIGINAL ARTICLE Source Type: research
The S. mutans mntE gene encodes a manganese efflux transporter
In conclusion, theS. mutans SMU_1176 gene, which we renamedmntE, is a manganese efflux transporter that contributes to essential metal ion homeostasis as part of the SloR regulon. (Source: Molecular Oral Microbiology)
Source: Molecular Oral Microbiology - May 4, 2020 Category: Microbiology Authors: Joseph O'Brien,
Alexander Pastora,
Andrew Stoner,
Grace Spatafora Tags: ORIGINAL ARTICLE Source Type: research
Ribosomal protein L4 of Lactobacillus rhamnosus LRB alters resistance to macrolides and other antibiotics
In this study, we isolated a nontargeted mutant that was particularly sensitive to acid stress. Using next generation sequencing, we further mapped the putative mutations in the genome and found that the mutant had acquired a deletion of 75 base pairs in therplD gene that encodes the large ribosomal subunit L4. The mutant had a growth defect at 37 °C and at ambient temperature. Further antibiotic sensitivity analyses indicated that the mutant is relatively more resistant to erythromycin and chloramphenicol; two antibiotics that target the 50S subunit. In contrast, the mutant was more sensitive to tetracycline, which targe...
Source: Molecular Oral Microbiology - May 4, 2020 Category: Microbiology Authors: Saswati Biswas,
Andrew Keightley,
Indranil Biswas Tags: ORIGINAL ARTICLE Source Type: research
Issue Information
Molecular Oral Microbiology, Volume 35, Issue 3, Page i-iv, June 2020. (Source: Molecular Oral Microbiology)
Source: Molecular Oral Microbiology - May 4, 2020 Category: Microbiology Tags: ISSUE INFORMATION Source Type: research
