scholarly journals Mechanistic insights into the inhibitory effect of theaflavins on virulence factors production in Streptococcus mutans

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Junhao Kong ◽  
Kai Xia ◽  
Xiaoqin Su ◽  
Xuan Zheng ◽  
Chunhua Diao ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Streptococcus Mutans ◽  
Virulence Factors ◽  
Biofilm Formation ◽  
Protein Biosynthesis ◽  
Peptide Transport ◽  
Protective Mechanism ◽  
Dependent Manner ◽  
Expression Of Genes ◽  
A Genome

AbstractStreptococcus mutans is the primary etiological agent associated with cariogenic process. The present study aimed to investigate the antibacterial and anti-virulence activities of theaflavins (TFs) to Streptococcus mutans UA159 as well as the underlying mechanisms. The results showed that TFs were capable of suppressing the acid production, cell adherence, water-insoluble exopolysaccharides production, and biofilm formation by S. mutans UA159 with a dosage-dependent manner while without influencing the cell growth. By a genome-wide transcriptome analysis (RNA-seq), we found that TFs attenuated the biofilm formation of S. mutans UA159 by inhibiting glucosyltransferases activity and the production of glucan-binding proteins (GbpB and GbpC) instead of directly blocking the expression of genes coding for glucosyltransferases. Further, TFs inhibited the expression of genes implicated in peptidoglycan synthesis, glycolysis, lipid synthesis, two-component system, signaling peptide transport (comA), oxidative stress response, and DNA replication and repair, suggesting that TFs suppressed the virulence factors of S. mutans UA159 by affecting the signal transduction and cell envelope stability, and weakening the ability of cells on oxidative stress resistance. In addition, an upregulated expression of the genes involved in protein biosynthesis, amino acid metabolism, and transport system upon TFs treatment indicated that cells increase the protein synthesis and nutrients uptake as one self-protective mechanism to cope with stress caused by TFs. The results of this study increase our current understanding of the anti-virulence activity of TFs on S. mutans and provide clues for the use of TFs in the prevention of dental caries.

Abstract 107: Apocynin Attenuates Isoproterenol-induced Myocardial Injury: Implications For Targeting Nadph Oxidase In Myocardial Fibrogenesis

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Yu Chen ◽  
Jingang Cui ◽  
Qinbo Yang ◽  
Chenglin Jia ◽  
Minqi Xiong ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nadph Oxidase ◽  
Myocardial Fibrosis ◽  
Myocardial Injury ◽  
Oxidase Inhibitor ◽  
Ros Generation ◽  
Dependent Manner ◽  
Expression Of Genes ◽  
Therapeutic Development ◽  
Myocardial Injuries

Myocardial fibrosis results from cardiac injuries caused by various pathophysiological mechanisms including myocardial infarction, leading to destruction of myocardial architecture and progressive cardiac dysfunction. Oxidative stress is likely involved in myocardial ischemic injury and the subsequent tissue remodeling mediated by myocardial fibrogenesis. Our current study aimed to evaluate the implication of NADPH oxidase in overproduction of reactive oxygen species and its contribution to the pathogenesis of myocardial fibrogenesis after ischemic injuries. The effects of Apocynin, a selective NADPH oxidase inhibitor, were evaluated in the mouse model of isoproterenol-induced myocardial injury by histopathological approaches and whole-genome gene expression profiling. The results demonstrated that Apocynin was able to inhibit the development of ISO-induced myocardial necrotic lesions and fibrogenesis in a dose-dependent manner. Moreover, the preventive effects of Apocynin on myocardial injuries were associated with suppressed expression of genes implicated in inflammation responses and extracellular matrix, which were remarkably upregulated by isoproterenol administration. In summary, o ur study provides proof-of-concept for the involvement of NADPH oxidase-mediated ROS generation in myocardial ischemic injuries and fibrogenesis, which will benefit the mechanism-based therapeutic development targeting NADPH oxidase and oxidative stress in treating myocardial fibrosis and related disorders.

scholarly journals Comparative Transcriptome Analysis Reveals the Protective Mechanism of Glycyrrhinic Acid for Deoxynivalenol-Induced Inflammation and Apoptosis in IPEC-J2 Cells

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Xiaoxiang Xu ◽  
Guorong Yan ◽  
Juan Chang ◽  
Ping Wang ◽  
Qingqiang Yin ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Signaling Pathway ◽  
Transcriptome Analysis ◽  
Animal Feed ◽  
Control Group ◽  
Protective Mechanism ◽  
Dependent Manner ◽  
Gene Expressions ◽  
Lactate Dehydrogenase Release ◽  
Tnf Α

Deoxynivalenol (DON) is the most common mycotoxin that frequently contaminates human food and animal feed, resulting in intestinal diseases and systemic immunosuppression. Glycyrrhinic acid (GA) exhibits various pharmacological activities. To investigate the protective mechanism of GA for DON-induced inflammation and apoptosis in IPEC-J2 cells, RNA-seq analysis was used in the current study. The IPEC-J2 cells were treated with the control group (CON), 0.5 μg/mL DON, 400 μg/mL GA, and 400 μg/mL GA+0.5 μg/mL DON (GAD) for 6 h. Results showed that 0.5 μg/mL DON exposure for 6 h could induce oxidative stress, inflammation, and apoptosis in IPEC-J2 cells. GA addition could specifically promote the proliferation of DON-induced IPEC-J2 cells in a dose- and time-dependent manner. In addition, GA addition significantly increased Bcl-2 gene expression ( P < 0.05 ) and superoxide dismutase and catalase activities ( P < 0.01 ) and decreased lactate dehydrogenase release, the contents of malonaldehyde, IL-8, and NF-κB ( P < 0.05 ), the relative mRNA abundances of IL-6, IL-8, TNF-α, COX-2, NF-κB, Bax, and caspase 3 ( P < 0.01 ), and the protein expressions of Bax and TNF-α. Moreover, a total of 1576, 289, 1398, and 154 differentially expressed genes were identified in CON vs. DON, CON vs. GA, CON vs. GAD, and DON vs. GAD, respectively. Transcriptome analysis revealed that MAPK, TNF, and NF-κB signaling pathways and some chemokines played significant roles in the regulation of inflammation and apoptosis induced by DON. GA may alleviate DON cytotoxicity via the TNF signaling pathway by downregulating IL-15, CCL5, and other gene expressions. These results indicated that GA could alleviate DON-induced oxidative stress, inflammation, and apoptosis via the TNF signaling pathway in IPEC-J2 cells.

scholarly journals Suppressive Effects of Octyl Gallate on Streptococcus mutans Biofilm Formation, Acidogenicity, and Gene Expression

Molecules ◽  
2019 ◽  
Vol 24 (17) ◽  
pp. 3170 ◽  
Author(s):  
Vika Gabe ◽  
Tomas Kacergius ◽  
Saleh Abu-Lafi ◽  
Mouhammad Zeidan ◽  
Basheer Abu-Farich ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dental Caries ◽  
Streptococcus Mutans ◽  
Biofilm Formation ◽  
Colorimetric Method ◽  
Solid Surfaces ◽  
Dependent Manner ◽  
Oral Diseases ◽  
Expression Change ◽  
Biofilm Development

The accumulation of biofilm by Streptococcus mutans bacteria on hard tooth tissues leads to dental caries, which remains one of the most prevalent oral diseases. Hence, the development of new antibiofilm agents is of critical importance. The current study reports the results from testing the effectiveness of octyl gallate (C8-OG) against: (1) S. mutans biofilm formation on solid surfaces (polystyrene, glass), (2) acidogenicity, (3) and the expression of biofilm-related genes. The amount of biofilm formed by S. mutans bacteria was evaluated using the colorimetric method and optical profilometry. The pH of the biofilm growth medium was measured with microelectrode. A quantitative reverse transcription-polymerase chain reaction (RT-qPCR) was used to assess the expression of genes encoding glucan binding protein B (gbpB), glucosyltransferases B, -C, -D (gtfB, -C, -D), and the F-ATPase β subunit of the F1 protein (atpD). The results show that C8-OG significantly diminished biofilm formation by exposed S. mutans on solid surfaces and suppressed acidogenicity in a dose-dependent manner, compared to unexposed bacteria (p < 0.05). The C8-OG concentration of 100.24 µM inhibited S. mutans biofilm development on solid surfaces by 100% and prevented a decrease in pH levels by 99%. In addition, the RT-qPCR data demonstrate that the biofilm-producing bacteria treated with C8-OG underwent a significant reduction in gene expression in the case of the four genes under study (gbpB, gtfC, gtfD, and atpD), and there was a slight decrease in expression of the gtfB gene. However, C8-OG treatments did not produce significant expression change compared to the control for the planktonic cells, although there was a significant increase for the atpD gene. Therefore, C8-OG might be a potent antibiofilm and/or anticaries agent for oral formulations that aim to reduce the prevalence of dental caries.

scholarly journals Immunohistochemical Study of Nrf2-Antioxidant Response Element as Indicator of Oxidative Stress Induced by Cadmium in Developing Rats

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Sergio Montes ◽  
Daniel Juárez-Rebollar ◽  
Concepción Nava-Ruíz ◽  
Aurora Sánchez-García ◽  
Yesica Heras-Romero ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Morphological Changes ◽  
Antioxidant Response ◽  
Protective Mechanism ◽  
Antioxidant Response Element ◽  
Response Element ◽  
Expression Of Genes ◽  
Old Rats ◽  
Kidney Liver

In developing animals, Cadmium (Cd) induces toxicity to many organs including brain. Reactive oxygen species (ROS) are often implicated in Cd-inducedtoxicity and it has been clearly demonstrated that oxidative stress interferes with the expression of genes as well as transcriptional factors such as Nrf2-dependent Antioxidant Response Element (Nrf2-ARE). Cd-generated oxidative stress and elevated Nrf2 activity have been reportedin vitroandin situcells. In this study we evaluated the morphological changes and the expression pattern of Nrf2 and correlated them with the Cd concentrations in different ages of developing rats in heart, lung, kidney, liver, and brain. The Cd content in different organs of rats treated with the metal was increased in all ages assayed. Comparatively, lower Cd brain levels were found in rats intoxicated at the age of 12 days, then pups treated at 5, 10, or 15 days old, at the same metal dose. No evident changes, as a consequence of cadmium exposure, were evident in the morphological analysis in any of the ages assayed. However, Nrf2-ARE immunoreactivity was observed in 15-day-old rats exposed to Cd. Our results support that fully developed blood-brain barrier is an important protector against Cd entrance to brain and that Nrf2 increased expression is a part of protective mechanism against cadmium-induced toxicity.

scholarly journals PYED-1 Inhibits Biofilm Formation and Disrupts the Preformed Biofilm of Staphylococcus aureus

Antibiotics ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 240 ◽  
Author(s):  
Adriana Vollaro ◽  
Anna Esposito ◽  
Eliana Pia Esposito ◽  
Raffaele Zarrilli ◽  
Annalisa Guaragna ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Quorum Sensing ◽  
Biofilm Formation ◽  
Surface Proteins ◽  
Transcriptional Analysis ◽  
Capsular Polysaccharides ◽  
Dependent Manner ◽  
Chronic Infections ◽  
Concentration Dependent Manner ◽  
Expression Of Genes

Pregnadiene-11-hydroxy-16α,17α-epoxy-3,20-dione-1 (PYED-1), a heterocyclic corticosteroid derivative of deflazacort, exhibits broad-spectrum antibacterial activity against Gram-negative and Gram-positive bacteria. Here, we investigated the effect of PYED-1 on the biofilms of Staphylococcus aureus, an etiological agent of biofilm-based chronic infections such as osteomyelitis, indwelling medical device infections, periodontitis, chronic wound infections, and endocarditis. PYED-1 caused a strong reduction in biofilm formation in a concentration dependent manner. Furthermore, it was also able to completely remove the preformed biofilm. Transcriptional analysis performed on the established biofilm revealed that PYED-1 downregulates the expression of genes related to quorum sensing (agrA, RNAIII, hld, psm, and sarA), surface proteins (clfB and fnbB), secreted toxins (hla, hlb, and lukD), and capsular polysaccharides (capC). The expression of genes that encode two main global regulators, sigB and saeR, was also significantly inhibited after treatment with PYED-1. In conclusion, PYED-1 not only effectively inhibited biofilm formation, but also eradicated preformed biofilms of S. aureus, modulating the expression of genes related to quorum sensing, surface and secreted proteins, and capsular polysaccharides. These results indicated that PYED-1 may have great potential as an effective antibiofilm agent to prevent S. aureus biofilm-associated infections.

scholarly journals Pleiotropic Regulation of Virulence Genes in Streptococcus mutans by the Conserved Small Protein SprV

2017 ◽  
Vol 199 (8) ◽  
Author(s):  
Manoharan Shankar ◽  
Mohammad S. Hossain ◽  
Indranil Biswas
Keyword(s):  
Dental Caries ◽  
Streptococcus Mutans ◽  
Virulence Factors ◽  
Biofilm Formation ◽  
Normal Growth ◽  
Hypothetical Protein ◽  
Bacteriocin Production ◽  
Transcript Levels ◽  
Content Type ◽  
Tooth Surfaces

ABSTRACT Streptococcus mutans, an oral pathogen associated with dental caries, colonizes tooth surfaces as polymicrobial biofilms known as dental plaque. S. mutans expresses several virulence factors that allow the organism to tolerate environmental fluctuations and compete with other microorganisms. We recently identified a small hypothetical protein (90 amino acids) essential for the normal growth of the bacterium. Inactivation of the gene, SMU.2137, encoding this protein caused a significant growth defect and loss of various virulence-associated functions. An S. mutans strain lacking this gene was more sensitive to acid, temperature, osmotic, oxidative, and DNA damage-inducing stresses. In addition, we observed an altered protein profile and defects in biofilm formation, bacteriocin production, and natural competence development, possibly due to the fitness defect associated with SMU.2137 deletion. Transcriptome sequencing revealed that nearly 20% of the S. mutans genes were differentially expressed upon SMU.2137 deletion, thereby suggesting a pleiotropic effect. Therefore, we have renamed this hitherto uncharacterized gene as sprV (streptococcal pleiotropic regulator of virulence). The transcript levels of several relevant genes in the sprV mutant corroborated the phenotypes observed upon sprV deletion. Owing to its highly conserved nature, inactivation of the sprV ortholog in Streptococcus gordonii also resulted in poor growth and defective UV tolerance and competence development as in the case of S. mutans. Our experiments suggest that SprV is functionally distinct from its homologs identified by structure and sequence homology. Nonetheless, our current work is aimed at understanding the importance of SprV in the S. mutans biology. IMPORTANCE Streptococcus mutans employs several virulence factors and stress resistance mechanisms to colonize tooth surfaces and cause dental caries. Bacterial pathogenesis is generally controlled by regulators of fitness that are critical for successful disease establishment. Sometimes these regulators, which are potential targets for antimicrobials, are lost in the genomic context due to the lack of annotated homologs. This work outlines the regulatory impact of a small, highly conserved hypothetical protein, SprV, encoded by S. mutans. We show that SprV affects the transcript levels of various virulence factors required for normal growth, biofilm formation, stress tolerance, genetic competence, and bacteriocin production.

scholarly journals Eleutheroside K Isolated from Acanthopanax henryi (Oliv.) Harms Inhibits the Expression of Virulence-Related Exoproteins in Methicillin-Resistant Staphylococcus aureus

2021 ◽  
Author(s):  
Qian-Qian Li ◽  
Jiao Luo ◽  
Xiang-Qian Liu ◽  
Ok-Hwa Kang ◽  
Dong-Yeul Kwon
Keyword(s):  
Virulence Factors ◽  
Enzyme Linked Immunosorbent Assay ◽  
Dependent Manner ◽  
Methicillin Resistant ◽  
Innovative Strategy ◽  
Expression Of Genes ◽  
Tnf Α ◽  
Single Compound ◽  
Mrsa Infection ◽  
Dose Dependent

AbstractMethicillin-resistant Staphylococcus (S.) aureus (MRSA) is a representative pathogen that produces numerous virulence factors involving manifold cytotoxins and exotoxins. The present study was designed to investigate the influence of Eleutheroside K (ETSK), a single compound isolated from the leaves of Acanthopanax (A.) henryi (Oliv.) Harms, on the exotoxins secreted by MRSA. The transcription and translation of the exotoxins (α-hemolysin and staphylococcal enterotoxins) related to virulence in S. aureus were determined via quantitative RT-PCR and western blot analysis. The effect of ETSK on the production of tumor necrosis factor (TNF)-α was evaluated using enzyme-linked immunosorbent assay. As a result, ETSK at sub-MIC concentrations could reduce the protein expression of α-hemolysin and enterotoxin, and the expression of genes that regulate virulence factors was also inhibited. In addition, the TNF-inducing activity of S. aureus was attenuated by ETSK in a dose-dependent manner. These results revealed that ETSK not only reduced the protein and gene expression levels of related exotoxins but also suppressed the ability of S. aureus to induce macrophages to release cytokines. This study indicated that the inhibition of MRSA infection by ETSK may be achieved by reducing the virulence of S. aureus and highlighted the potential of ETSK as an innovative strategy for the prevention and treatment of MRSA infections.

scholarly journals Sulfate-Dependent Repression of Genes That Function in Organosulfur Metabolism in Bacillus subtilis Requires Spx

2005 ◽  
Vol 187 (12) ◽  
pp. 4042-4049 ◽  
Author(s):  
Kyle N. Erwin ◽  
Shunji Nakano ◽  
Peter Zuber
Keyword(s):  
Oxidative Stress ◽  
Bacillus Subtilis ◽  
Rna Polymerase ◽  
Transcriptional Control ◽  
Sulfur Metabolism ◽  
Growth Conditions ◽  
Sulfur Source ◽  
Dependent Manner ◽  
Α Subunit ◽  
A Genome

ABSTRACT Oxidative stress in Bacillus subtilis results in the accumulation of Spx protein, which exerts both positive and negative transcriptional control over a genome-wide scale through its interaction with the RNA polymerase α subunit. Previous microarray transcriptome studies uncovered a unique class of genes that are controlled by Spx-RNA polymerase interaction under normal growth conditions that do not promote Spx overproduction. These genes were repressed by Spx when sulfate was present as a sole sulfur source. The genes include those of the ytmI, yxeI, and ssu operons, which encode products resembling proteins that function in the uptake and desulfurization of organic sulfur compounds. Primer extension and analysis of operon-lacZ fusion expression revealed that the operons are repressed by sulfate and cysteine; however, Spx functioned only in sulfate-dependent repression. Both the ytmI operon and the divergently transcribed ytlI, encoding a LysR-type regulator that positively controls ytmI operon transcription, are repressed by Spx in sulfate-containing media. The CXXC motif of Spx, which is necessary for redox sensitive control of Spx activity in response to oxidative stress, is not required for sulfate-dependent repression. The yxeL-lacZ and ssu-lacZ fusions were also repressed in an Spx-dependent manner in media containing sulfate as the sole sulfur source. This work uncovers a new role for Spx in the control of sulfur metabolism in a gram-positive bacterium under nonstressful growth conditions.

Lemon myrtle extract inhibits lactate production by Streptococcus mutans

2021 ◽  
Vol 85 (10) ◽  
pp. 2185-2190
Author(s):  
Yukinori Yabuta ◽  
Yui Sato ◽  
Arisu Miki ◽  
Ryuta Nagata ◽  
Tomohiro Bito ◽  
...  
Keyword(s):  
Lactate Dehydrogenase ◽  
Dental Caries ◽  
Oral Cavity ◽  
Streptococcus Mutans ◽  
Virulence Factors ◽  
Biofilm Formation ◽  
Tooth Enamel ◽  
Lactate Production ◽  
Tooth Decay ◽  
Lactate Dehydrogenase Activity

ABSTRACT Backhousia citriodora (lemon myrtle) extract has been found to inhibit glucansucrase activity, which plays an important role in biofilm formation by Streptococcus mutans. In addition to glucansucrase, various virulence factors in S. mutans are involved in the initiation of caries. Lactate produced by S. mutans demineralizes the tooth enamel. This study investigated whether lemon myrtle extract can inhibit S. mutans lactate production. Lemon myrtle extract reduced the glycolytic pH drop in S. mutans culture and inhibited lactate production by at least 46%. Ellagic acid, quercetin, hesperetin, and myricetin, major polyphenols in lemon myrtle, reduced the glycolytic pH drop and lactate production, but not lactate dehydrogenase activity. Furthermore, these polyphenols reduced the viable S. mutans cell count. Thus, lemon myrtle extracts may inhibit S. mutans-mediated acidification of the oral cavity, thereby preventing dental caries and tooth decay.

Sign in / Sign up

Export Citation Format

Share Document