Identification of Streptococcus mutans genes involved in fluoride resistance by screening of a transposon mutant library.

Fluoride has been used as an effective anticaries agent for more than 70 years, which might result in the emergence of fluoride-resistant strains. However, the fluoride resistance mechanism and the cariogenic properties of fluoride-resistant mutant for cariogenic bacterial species Streptococcus mutans remain largely unknown. We describe here the construction and characterization of a mariner-based transposon system designed to be used in S.

Corrigendum: Transcriptome, Phenotypic, and Virulence Analysis of SK36 Wild Type and Its CcpA-Null Derivative (ΔCcpA).

[This corrects the article DOI: 10.3389/fcimb.2019.

Transcriptome, Phenotypic, and Virulence Analysis of SK36 Wild Type and Its CcpA-Null Derivative (ΔCcpA).

Catabolic control protein (CcpA) is linked to complex carbohydrate utilization and virulence factor in many bacteria species, influences the transcription of target genes by many mechanisms. To characterize the activity and regulatory mechanisms of CcpA in , here, we analyzed the transcriptome of SK36 and its CcpA-null derivative (ΔCcpA) using RNA-seq. Compared to the regulon of CcpA in SK36 in the RegPrecise database, we found that only minority of differentially expressed genes (DEGs) contained putative catabolite response element (cre) in their regulatory regions, indicating that many genes could have been affected indirectly by the loss of CcpA and analyzing the sequence of the promoter region using prediction tools is not a desirable method to recognize potential target genes of global regulator CcpA.

Coccomyxa Gloeobotrydiformis Polysaccharide Inhibits Lipopolysaccharide-Induced Inflammation in RAW 264.7 Macrophages.

Background/aims: Inflammation plays a vital role in the etiology and pathogenesis of chronic noncommunicable diseases (NCDs), which are the leading health issues throughout the world. Our previous studies verified the satisfactory therapeutic effects of Coccomyxa gloeobotrydiformis (CGD) polysaccharide on several NCDs. In this study, we aimed to investigate the anti-inflammatory effects of CGD polysaccharide, and the corresponding molecular mechanisms, on lipopolysaccharide (LPS)-induced inflammation in RAW264.

Chitosan Oligosaccharides Improve Glucolipid Metabolism Disorder in Liver by Suppression of Obesity-Related Inflammation and Restoration of Peroxisome Proliferator-Activated Receptor Gamma (PPARγ).

Chitosan oligosaccharides (COS) display various biological activities. In this study, we aimed to explore the preventive effects of COS on glucolipid metabolism disorder using palmitic acid (PA)-induced HepG2 cells and high-fat diet (HFD)-fed C57BL/6J mice as experimental models in vitro and in vivo, respectively. The results showed that COS pretreatment for 12 h significantly ameliorated lipid accumulation in HepG2 cells exposed to PA for 24 h, accompanied by a reversing of the upregulated mRNA expression of proinflammatory cytokines (IL-6, MCP-1, TNF-α) and glucolipid metabolism-related regulators (SCD-1, ACC1, PCK1-α).

Therapeutic Effects of Coccomyxagloeobotrydiformis on the Metabolic Syndrome in Rats.

Background/aims: The metabolic syndrome (MS) is a cluster of metabolic changes that carry a high risk of cardiovascular disease (CVD). A newly discovered microalga, coccomyxagloeobotrydiformis (CGD), has been reported to improve ischemic stroke and metabolism-related indicators. We observed the therapeutic effects of CGD on MS and postulated the underlying mechanism.

Shexiang Baoxin Pill Corrects Metabolic Disorders in a Rat Model of Metabolic Syndrome by Targeting Mitochondria.

Metabolic syndrome (MS) is a global epidemic that has great socioeconomic and public health implications. This study reports observed effects of the Shexiang Baoxin Pill (SBP) in a rat model of MS and explores its underlying mechanisms of action. A diet-induced rat model of MS was established according to accepted methods, and the rats were randomly divided into two groups: a control group (0.

Rational design of Pleurotus eryngii versatile ligninolytic peroxidase for enhanced pH and thermal stability through structure-based protein engineering.

Versatile peroxidase (VP) from Pleurotus eryngii is a high redox potential peroxidase. It has aroused great biotechnological interest due to its ability to oxidize a wide range of substrates, but its application is still limited due to low pH and thermal stability. Since CiP (Coprinopsis cinerea peroxidase) and PNP (peanut peroxidase) exhibited higher pH and thermal stability than VP, several motifs, which might contribute to their pH and thermal stability, were identified through structure and sequence alignment.

Mitochondrial Genome Encoded Proteins Expression Disorder, the Possible Mechanism of the Heart Disease in Metabolic Syndrome.

Background/aims: The direct consequence of metabolic syndrome (MS) is the increased morbidity and mortality caused by the heart disease. We tried to explain why the heart is more severely damaged during MS from the point of mitochondria, the center of cellular metabolism.

Methods: 1.

Is SpxA2 involved in hydrogen peroxide production and competence development in Streptococcus sanguinis?

Purpose: The objective of the present study was to investigate whether Streptococcus sanguinis SpxA2 plays a role in competence development and endogenous H2O2 generation, and whether the SpxA2 Cys10-XX-Cys13 (CXXC) motif is involved in competence development.

Methodology: The competence development of wild-type S. sanguinis (SK36) and its derivatives was compared by transformation efficiency assay and real-time RT-PCR.

Insight into the impact of two structural calcium ions on the properties of Pleurotus eryngii versatile ligninolytic peroxidase.

Two structural Ca (proximal and distal) is known to be important for ligninolytic peroxidases. However, few studies toward impact of residues involved in two Ca on properties of ligninolytic peroxidases have been done, especially the proximal one. In this study, mutants of nine residues involved in liganding two Ca of Pleurotus eryngii versatile peroxidase (VP) were investigated.

SpxB-mediated H2 O2 induces programmed cell death in Streptococcus sanguinis.

Streptococcus sanguinis (S. sanguinis) is a commensal oral streptococci that produces hydrogen peroxide (H2 O2 ), and this production is dependent on pyruvate oxidase (SpxB) activity. In addition to its well-known role in intraspecies or interspecies competitions, recent studies have shown that H2 O2 produced by S.

Hydrogen peroxide-dependent DNA release and transfer of antibiotic resistance genes in Streptococcus gordonii.

Certain oral streptococci produce H(2)O(2) under aerobic growth conditions to inhibit competing species like Streptococcus mutans. Additionally, H(2)O(2) production causes the release of extracellular DNA (eDNA). eDNA can participate in several important functions: biofilm formation and cell-cell aggregation are supported by eDNA, while eDNA can serve as a nutrient and as an antimicrobial agent by chelating essential cations.

Environmental influences on competitive hydrogen peroxide production in Streptococcus gordonii.

Streptococcus gordonii is an important member of the oral biofilm. One of its phenotypic traits is the production of hydrogen peroxide (H2O2). H2O2 is an antimicrobial component produced by S.

Oxygen dependent pyruvate oxidase expression and production in Streptococcus sanguinis.

The objective of this study was to characterize the oxygen dependent regulation of pyruvate oxidase (SpxB) gene expression and protein production in Streptococcus sanguinis (S. sanguinis). SpxB is responsible for the generation of growth-inhibiting amounts of hydrogen peroxide (H2O2) able to antagonize cariogenic Streptococcus mutans (S.

Catabolite control protein A controls hydrogen peroxide production and cell death in Streptococcus sanguinis.

Streptococcus sanguinis is a commensal oral bacterium producing hydrogen peroxide (H₂O₂) that is dependent on pyruvate oxidase (Spx) activity. In addition to its well-known role in bacterial antagonism during interspecies competition, H₂O₂ causes cell death in about 10% of the S. sanguinis population.

In vivo kinetics and biodistribution of a Hantaan virus DNA vaccine after intramuscular injection in mice.

To study the kinetics in vivo of a Hantaan virus DNA vaccine, we constructed a fusion DNA vaccine, pEGFP/S, by cloning the S segment of Hantavirus into the vector, pEGFP-C1, which encodes Green fluorescent protein EGFP. In this report, we provide evidence that pEGFP/S was distributed and persistently expressed for more than 60 days in several organs after inoculation. Our findings suggest that the persistent immune responses induced by a Hantaan virus DNA vaccine are likely due to the plasmid pEGFP/S deposited in vivo, which acts as a booster immunization.

Genetic characterization of the hdrRM operon: a novel high-cell-density-responsive regulator in Streptococcus mutans.

Many species of bacteria can adhere to surfaces and grow as sessile communities. The continued accumulation of bacteria can eventually lead to the extremely high-cell-density environment characteristic of many biofilms or cell colonies. This is the normal habitat of the cariogenic species Streptococcus mutans, which normally resides in the high-cell-density, multispecies community commonly referred to as dental plaque.

Enhancing DNA vaccine potency against hantavirus by co-administration of interleukin-12 expression vector as a genetic adjuvant.

Background: The heavy incidence and mortality of hemorrhagic fever with renal syndrome, as well as no specific drugs in curing the disease, clearly indicate the need for development of the more effective hantavirus vaccine. Refining the DNA vaccination strategy to elicit more clinically efficacious immune responses is now under intensive investigation. In the present study, we examined the effects of using an interleukin-12 expression plasmid as a genetic adjuvant to enhance the immune responses induced by a DNA vaccine based on the S gene encoding nucleocapsid protein against hantavirus.