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Journal of Experimental & Clinical... Jan 2022Immune checkpoint inhibitor-related cardiotoxicity is one of the most lethal adverse effects, and thus, the identification of underlying mechanisms for developing...
BACKGROUND
Immune checkpoint inhibitor-related cardiotoxicity is one of the most lethal adverse effects, and thus, the identification of underlying mechanisms for developing strategies to overcome it has clinical importance. This study aimed to investigate whether microbiota-host interactions contribute to PD-1/PD-L1 inhibitor-related cardiotoxicity.
METHODS
A mouse model of immune checkpoint inhibitor-related cardiotoxicity was constructed by PD-1/PD-L1 inhibitor BMS-1 (5 and 10 mg/kg), and cardiomyocyte apoptosis and cardiotoxicity were determined by hematoxylin and eosin, Masson's trichome and TUNEL assays. 16S rRNA sequencing was used to define the gut microbiota composition. Gut microbiota metabolites short-chain fatty acids (SCFAs) were determined by HPLC. The serum levels of myocardial enzymes (creatine kinase, aspartate transaminase, creatine kinase-MB and lactate dehydrogenase) and the production of M1 factors (TNF-α and IL-1β) were measured by ELISA. The colonic macrophage phenotype was measured by mmunofluorescence and qPCR. The expression of Claudin-1, Occludin, ZO-1 and p-p65 was measured by western blot. The gene expression of peroxisome proliferator-activated receptor α (PPARα) and cytochrome P450 (CYP) 4X1 was determined using qPCR. Statistical analyses were performed using Student's t-test for two-group comparisons, and one-way ANOVA followed by Student-Newman-Keul test for multiple-group comparisons.
RESULTS
We observed intestinal barrier injury and gut microbiota dysbiosis characterized by Prevotellaceae and Rikenellaceae genus depletion and Escherichia-Shigella and Ruminococcaceae genus enrichment, accompanied by low butyrate production and M1-like polarization of colonic macrophages in BMS-1 (5 and 10 mg/kg)-induced cardiotoxicity. Fecal microbiota transplantation mirrored the effect of BMS-1 on cardiomyocyte apoptosis and cardiotoxicity, while macrophage depletion and neutralization of TNF-α and IL-1β greatly attenuated BMS-1-induced cardiotoxicity. Importantly, Prevotella loescheii recolonization and butyrate supplementation alleviated PD-1/PD-L1 inhibitor-related cardiotoxicity. Mechanistically, gut microbiota dysbiosis promoted M1-like polarization of colonic macrophages and the production of proinflammatory factors TNF-α and IL-1β through downregulation of PPARα-CYP4X1 axis.
CONCLUSIONS
Intestinal barrier dysfunction amplifies PD-1/PD-L1 inhibitor-related cardiotoxicity by upregulating proinflammatory factors TNF-α and IL-1β in colonic macrophages via downregulation of butyrate-PPARα-CYP4X1 axis. Thus, targeting gut microbiota to polarize colonic macrophages away from the M1-like phenotype could provide a potential therapeutic strategy for PD-1/PD-L1 inhibitor-related cardiotoxicity.
Topics: Animals; Butyrates; Cardiotoxicity; Colon; Cytochrome P-450 Enzyme System; Disease Models, Animal; Fecal Microbiota Transplantation; Humans; Immune Checkpoint Inhibitors; Macrophages; Male; Mice; Transfection
PubMed: 34980222
DOI: 10.1186/s13046-021-02201-4 -
Journal of Indian Society of... 2023is a Gram-negative anaerobic bacilli. The phenotypic characteristics of the various species of are similar, which often makes it difficult in routine differentiation...
Simultaneous detection and evaluation of , and in subgingival plaque samples of chronic periodontitis and healthy individuals through multiplex polymerase chain reaction.
BACKGROUND
is a Gram-negative anaerobic bacilli. The phenotypic characteristics of the various species of are similar, which often makes it difficult in routine differentiation and identification of all the species.
AIM
The purpose of the study was to detect and compare presence of , and in subgingival plaque samples of chronic periodontitis and healthy individuals.
MATERIALS AND METHODS
Two hundred and thirty-six subjects were considered consisting of chronic periodontitis (128) and healthy (108) individuals. Subgingival plaque sample was collected in reduced transport fluid and analyzed. DNA extraction and polymerase chain reaction (PCR) were performed for genus followed by positive samples were considered for the detection of selected species through multiplex PCR using specific primers.
RESULTS
Out of 236 samples, 94.1% were positive for genus . Out of 222 cases showed the highest number of cases positive (59.5%) followed by (57.2%), (55.4%), and (40.1%). Species were analyzed individually between chronic periodontitis and healthy, , and showed greater positivity in healthy compared to chronic periodontitis. Positivity for was high in chronic periodontitis compared to healthy.
CONCLUSION
The number of positive cases for species, when correlated with clinical parameters showed an increase in mean score for all clinical parameters assessed, suggesting the presence of variation in the prevalence of species and geographic variation do exist in oral microflora. Findings suggest that they can be normal commensals and opportunistic.
PubMed: 37346862
DOI: 10.4103/jisp.jisp_154_22 -
International Journal of Systematic... Oct 1992During studies of human periodontal disease, a number of bacterial strains were encountered that, on the basis of results of standard biochemical tests, appeared to be...
During studies of human periodontal disease, a number of bacterial strains were encountered that, on the basis of results of standard biochemical tests, appeared to be Prevotella buccalis, Prevotella denticola, Prevotella melaninogenica, or Prevotella loescheii. However, use of the standard biochemical tests, cellular fatty acid analyses, and the polyacrylamide gel electrophoresis patterns of soluble proteins resulted in conflicting identifications of these strains. The results of tests for cellobiose fermentation, inulin fermentation, and pigment production were responsible for most of the discordant results. Cellular fatty acid analyses in which the Microbial Identification System was used did not differentiate these strains from validly described species, even though separate library entries were created for them. DNA reassociation determinations in which the S1 nuclease procedure was used showed that cellobiose fermentation and pigment production are variable among strains of P. melaninogenica and P. denticola and that fermentation of xylan is not a reliable characteristic for differentiating P. buccalis from Prevotella veroralis. In contrast to previous indications, most strains of P. veroralis do not ferment xylan. These species can be differentiated by DNA-DNA reassociation and by cellular fatty acid analysis, using the Microbial Identification System, but differentiation by currently described phenotypic characteristics is not reliable. Similarly, P. loescheii and the genetically distinct (but closely related) D1C-20 group cannot be distinguished reliably from each other or from P. veroralis, P. denticola, and P. melaninogenica on the basis of currently described phenotypic tests other than cellular fatty acid composition or, for some species, electrophoretic patterns of soluble whole-cell proteins.
Topics: Bacterial Typing Techniques; Bacteroides; Cellobiose; Culture Media; DNA, Bacterial; Fatty Acids; Fermentation; Humans; Phenotype; Xylans
PubMed: 1390106
DOI: 10.1099/00207713-42-4-536 -
Journal of Bacteriology Apr 1994The 2.4-kb plaA gene, which encodes a Prevotella loescheii galactoside-specific adhesin, contains a programmed frameshifting hop. The frameshift region consists of two...
The 2.4-kb plaA gene, which encodes a Prevotella loescheii galactoside-specific adhesin, contains a programmed frameshifting hop. The frameshift region consists of two UAA termination codons, two repeats of four identical bases between the terminators, and a stem-loop structure that has the potential to form a pseudoknot located downstream from the second UAA. The stem-loop and pseudoknot are features found in a number of retroviruses where frameshifting is a more common occurrence. The terminators, sequence repeats, and secondary structures were identified in both the P. loescheii plaA gene and the mRNA transcript. An in-frame fusion of the entire plaA frameshift region between codons 9 and 10 of the lacZ gene permitted relatively efficient expression (4 to 25% of that of the control) of beta-galactosidase in Escherichia coli.
Topics: Adhesins, Bacterial; Amino Acid Sequence; Bacteria; Bacterial Adhesion; Bacterial Proteins; Base Sequence; Gene Expression Regulation, Bacterial; Genes, Bacterial; Genes, Reporter; Lac Operon; Lectins; Models, Genetic; Molecular Sequence Data; Nucleic Acid Conformation; Reading Frames; Recombinant Fusion Proteins
PubMed: 8144461
DOI: 10.1128/jb.176.7.1944-1948.1994 -
Frontiers in Oral Health 2021Periodontitis, a chronic inflammatory oral infection is the outcome of disturbances in the homeostasis of the oral biofilm microbiota. A number of studies have found...
Periodontitis, a chronic inflammatory oral infection is the outcome of disturbances in the homeostasis of the oral biofilm microbiota. A number of studies have found the occurrence of species in elevated levels in periodontitis compared to healthy subjects. Even though different aspects of as part of oral biofilm have been studied, biofilms formed by these species have not been characterized systematically. The objective of this study was to characterize biofilms formed by several species and further to assess biofilm inhibition and detachment of preformed biofilms. Biofilms were grown in 24-well plates containing brucella broth in anaerobic conditions for 3 days, and were quantified using crystal violet staining. Images of SYTO 9 Green fluorescent stained biofilms were captured using confocal microscopy. Biofilm inhibition and detachment by proteinase and DNase I was tested. The biochemical characterization included quantification of proteins and DNA in the biofilms and biofilm-supernatants. and showed highest biofilm formation. formed significantly higher amounts of biofilms than ( = 0.005) and ( = 0.0013). Inhibition of biofilm formation was significant only in the case of when treated with proteinase ( = 0.037), whereas with DNase I treatment, the inhibition was not significant ( = 0.531). Overall, proteinase was more effective in biofilm detachment than DNase I. Protein and DNA content were higher in biofilm than the supernatant with the highest amounts found in biofilm and supernatants. biofilms appeared to secrete large amounts of proteins extracellularly into the biofilm-supernatants. Significant differences among species to form biofilms may imply their variable abilities to get integrated into oral biofilm communities. Of the species that were able to grow as biofilms, DNase I and proteinase inhibited the biofilm growth or were able to cause biofilm detachment.
PubMed: 35048047
DOI: 10.3389/froh.2021.724194 -
Infection and Immunity Apr 1992Prevotella loescheii PK1295 can grow on native hemoglobin as a source of heme. Supernatants of P. loescheii cultures hemolysed human erythrocytes and degraded native...
Prevotella loescheii PK1295 can grow on native hemoglobin as a source of heme. Supernatants of P. loescheii cultures hemolysed human erythrocytes and degraded native hemoglobin. These combined activities may provide heme (or iron) for the growth of P. loescheii and other dental plaque bacteria.
Topics: Cell Division; Heme; Hemoglobins; Hemolysis; Humans; In Vitro Techniques
PubMed: 1548099
DOI: 10.1128/iai.60.4.1721-1723.1992 -
Current Microbiology Feb 2001Heat shock proteins play an important role in bacterial survival and response to environmental stress. We cloned the Prevotella loescheii HSP70 homolog (dnaK) and...
Heat shock proteins play an important role in bacterial survival and response to environmental stress. We cloned the Prevotella loescheii HSP70 homolog (dnaK) and characterized the coding sequence, regulatory regions, and evolutionary relationships to other bacteria. Predicted proteins encoded by the P. loescheii dnaK homolog (open reading frame ORF-1) and two downstream coding regions, ORF-2 and ORF-3, are highly homologous to the proteins encoded by ORF-4 (dnaK), ORF-5, and ORF-6 from the dnaK region of Porphyromonas gingivalis. The dnaK promoter resembles other HSP (heat shock protein) promoters. Alignment of the predicted protein encoded by ORF-2 showed significant homology to the Bacteroides fragilis tnpA gene from the transposon Tn4555, whereas the ORF-3 protein showed homology to B. fragilis transposase (Tn5220) and integrase (Tn4555) proteins. This suggests a transposition-like event may be responsible for transfer of these genes between Porphyromonas and Prevotella.
Topics: Amino Acid Sequence; Base Sequence; Escherichia coli Proteins; Evolution, Molecular; Genes, Bacterial; HSP70 Heat-Shock Proteins; Models, Genetic; Molecular Sequence Data; Nucleic Acid Conformation; Open Reading Frames; Porphyromonas gingivalis; Prevotella; RNA, Bacterial; RNA, Messenger; Sequence Homology, Amino Acid
PubMed: 11136127
DOI: 10.1007/s0028403313 -
Oral Microbiology and Immunology Aug 1992Soluble sonic extracts of Prevotella loescheii caused a dose-dependent inhibition of human peripheral blood lymphocyte proliferation by mitogen and of the proliferation...
Soluble sonic extracts of Prevotella loescheii caused a dose-dependent inhibition of human peripheral blood lymphocyte proliferation by mitogen and of the proliferation of a leukemic cell line, BALL-1, when assessed by DNA synthesis (3H-thymidine incorporation). RNA (3H-uridine incorporation) and protein (3H-leucine incorporation) synthesis were similarly altered after exposure to the extract. There was no effect on cell viability as measured by either trypan blue exclusion or extracellular release of the cytoplasmic enzyme lactate dehydrogenase. Preliminary characterization indicates the suppressive factor(s) derived from P. loescheii to be a protein since it is heat-labile and trypsin-sensitive. The factor eluted in a peak on a high-pressure liquid chromatography gel filtration corresponding to a molecular weight of approximately 32,000. Since black-pigmented anaerobic rods have been implicated in the pathogenesis of periodontal disease, the data suggest that P. loescheii contributes to the disease process by suppressing lymphocyte function.
Topics: Bacterial Proteins; Bacteroides; Cell Division; DNA; Humans; Immunologic Factors; Lymphocyte Activation; Lymphocytes; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Sonication; Tumor Cells, Cultured; Virulence
PubMed: 1408357
DOI: 10.1111/j.1399-302x.1992.tb00030.x -
Current Microbiology Jan 1999The Prevotella loescheii adhesin gene, plaA, contains a coding gap between a small open reading frame (ORF-1) and a large open reading frame (ORF-2). Translation of the...
The Prevotella loescheii adhesin gene, plaA, contains a coding gap between a small open reading frame (ORF-1) and a large open reading frame (ORF-2). Translation of the plaA mRNA requires bypassing this 29-nt coding gap on the plaA transcript. We have determined the N-terminal peptide sequence of the SO34 adhesin beyond the gap sequence. This sequence shows that the peptide junction between ORF-1 and ORF-2 is continuous in the adhesin and supports the conclusion that synthesis of the SO34 adhesin occurs by a ribosomal hop mechanism. To elucidate upstream signals, we used the 5' RACE (rapid amplification of cDNA ends) technique to map the start point of the plaA mRNA. DNA sequencing of plasmids with the 5' RACE products placed the 5' end of plaA mRNA 270 nt upstream from the plaA start codon. A region corresponding to a Bacteroides fragilis promoter consensus sequence precedes this start site.
Topics: Adhesins, Bacterial; Amino Acid Sequence; Base Sequence; Genes, Bacterial; Lectins; Molecular Sequence Data; Polymerase Chain Reaction; Prevotella; Protein Biosynthesis; RNA, Messenger; Sequence Alignment; Transcription, Genetic
PubMed: 9841777
DOI: 10.1007/pl00006766 -
Journal of Bacteriology Nov 1992We cloned and sequenced the Prevotella loescheii gene plaA, which encodes a lectin-like adhesin that mediates the coaggregation of P. loescheii 1295 with Streptococcus... (Comparative Study)
Comparative Study
We cloned and sequenced the Prevotella loescheii gene plaA, which encodes a lectin-like adhesin that mediates the coaggregation of P. loescheii 1295 with Streptococcus oralis 34. A probe derived from the N-terminal amino acid sequence of the purified adhesin was used to identify the plaA gene from a P. loescheii genomic library constructed in lambda GEM-11. Sequence analysis of plaA indicates that the initial translation product contains a 22-amino-acid leader. The reading frame of the plaA gene is interrupted after amino acid 28 of the mature protein by a TAA termination codon. Amplification of the P. loescheii genomic DNA in the region surrounding this codon by the polymerase chain reaction followed by DNA sequencing of the cloned DNA fragment established that this stop codon was not an experimental artifact. A frameshift beginning 29 bp downstream of the ochre terminator was required to access the only large open reading frame in the gene. Amino acid sequences of six purified peptides derived by limited proteolysis of adhesin with endoproteinase Lys-C matched the downstream amino acid sequence derived by translation of the large open reading frame. The gene coding sequence of 2.4 kb contains sufficient information for the synthesis of an 89-kDa protein. A putative rho-independent terminator (delta G = -25.5 kcal/mol [ca. -107 kJ/mol]) was detected 38 bp downstream from the plaA stop codon.
Topics: Adhesins, Bacterial; Amino Acid Sequence; Bacterial Adhesion; Bacterial Proteins; Bacteroides; Base Sequence; Blotting, Southern; Calorimetry; Cloning, Molecular; Codon; DNA, Bacterial; Escherichia coli; Frameshift Mutation; Genes, Bacterial; Genomic Library; Lectins; Molecular Sequence Data; Molecular Weight; Oligonucleotide Probes; Open Reading Frames; Plasmids; Protein Conformation; Restriction Mapping; Sequence Homology, Amino Acid; Terminator Regions, Genetic
PubMed: 1429455
DOI: 10.1128/jb.174.22.7328-7336.1992