Contribution of the Sensor Histidine Kinases PhcS and VsrA to the Quorum Sensing of Strain OE1-1.

The soilborne Gram-negative phytopathogenic beta-proteobacterium strain OE1-1 produces methyl 3-hydroxymyristate (3-OH MAME) as the quorum sensing (QS) signal by the methyltransferase PhcB and senses the chemical, activating the LysR family transcriptional regulator PhcA, which regulates the QS-dependent genes responsible for QS-dependent phenotypes including virulence. The sensor histidine kinases PhcS and VsrA are reportedly involved in the regulation of QS-dependent genes. To elucidate the function of PhcS and VsrA in the active QS, we generated the deletion and -deletion mutants, which exhibited weak changes to their QS-dependent phenotypes including virulence.

Barbed vs conventional sutures for cesarean uterine scar defects: a randomized clinical trial.

Background: The role of barbed sutures in preventing myometrial defects and enhancing postpartum outcomes after cesarean section (C-section) is uncertain.

Objective: This study compared clinical and ultrasonographic outcomes of uterine scar defects after C-section with barbed and conventional smooth thread sutures.

Study Design: This was a multicenter, parallel-group, randomized, controlled clinical trial.

The Micacocidin Production-Related Deletion Alters the Quorum Sensing-Dependent Gene Regulation of Strain OE1-1.

The soil-borne phytopathogenic gram-negative bacterium species complex (RSSC) produces staphyloferrin B and micacocidin as siderophores that scavenge for trivalent iron (Fe) in the environment, depending on the intracellular divalent iron (Fe) concentration. The staphyloferrin B-deficient mutant reportedly retains its virulence, but the relationship between micacocidin and virulence remains unconfirmed. To elucidate the effect of micacocidin on RSSC virulence, we generated the micacocidin productivity-deficient mutant (Δ) that lacks , which encodes a putative polyketide synthase/non-ribosomal peptide synthetase, using the RSSC phylotype I strain OE1-1.

Disproof of the Structures and Biosynthesis of Ergoynes, Gs-Polyyne-l-Ergothioneine Cycloadducts from YC6258.

Some bacteria produce "bacterial polyynes" bearing a conjugated C≡C bond that starts with a terminal alkyne. Ergoynes A and B have been reported as sulfur-containing metabolites from YC6258. These compounds were thought to be formed by cycloaddition between a bacterial polyyne (named Gs-polyyne) and l-ergothioneine.

Structures and Biosynthesis of Caryoynencins, Unstable Bacterial Polyynes from Recombinant Expressing the Gene.

Bacteria in certain genera can produce "bacterial polyynes" that contain a conjugated C≡C bond starting from a terminal alkyne. Protegenin A is a derivative of octadecanoic acid that contains an ene-tetrayne moiety. It was discovered in Cab57 and exhibits strong antioomycete and moderate antifungal activity.

Astaxanthin protects human ARPE-19 retinal pigment epithelium cells from blue light-induced phototoxicity by scavenging singlet oxygen.

Age-related macular degeneration (AMD) is one of an increasing number of diseases that causes irreversible impairment and loss of vision in the elderly. AMD occurs by oxidative stress-mediated apoptosis of retinal pigment epithelium cells. The onset of AMD may be positively correlated with the exposure to blue light.

The transcription regulator ChpA affects the global transcriptome including quorum sensing-dependent genes in Ralstonia pseudosolanacearum strain OE1-1.

The gram-negative plant-pathogenic β-proteobacterium Ralstonia pseudosolanacearum strain OE1-1 produces methyl 3-hydroxymyristate as a quorum sensing (QS) signal through methyltransferase PhcB and senses the chemical via the sensor histidine kinase PhcS. This leads to activation of the LysR family transcription regulator PhcA, which regulates the genes (QS-dependent genes) responsible for QS-dependent phenotypes, including virulence. The transcription regulator ChpA, which possesses a response regulator receiver domain and also a hybrid sensor histidine kinase/response regulator phosphore-acceptor domain but lacks a DNA-binding domain, is reportedly involved in QS-dependent biofilm formation and virulence of R.

Quorum Sensing-Dependent Invasion of Ralstonia solanacearum into Fusarium oxysporum Chlamydospores.

Strains of the Ralstonia solanacearum species complex (RSSC), although known as the causative agent of bacterial wilt disease in plants, induce the chlamydospores of many fungal species and invade them through the spores. The lipopeptide ralstonins are the chlamydospore inducers produced by RSSC and are essential for this invasion. However, no mechanistic investigation of this interaction has been conducted.

The Quorum-Sensing System in Species Complex.

species complex (RSSC) strains are devastating plant pathogens distributed worldwide. The primary cell density-dependent gene expression system in RSSC strains is quorum sensing (QS). It regulates the expression of about 30% of all genes, including those related to cellular activity, primary and secondary metabolism, pathogenicity, and more.

Determinants of Subtype-Selectivity of the Anthelmintic Paraherquamide A on Nicotinic Acetylcholine Receptors.

The anthelmintic paraherquamide A acts selectively on the nematode L-type nicotinic acetylcholine receptors (nAChRs), but the mechanism of its selectivity is unknown. This study targeted the basis of paraherquamide A selectivity by determining an X-ray crystal structure of the acetylcholine binding protein (AChBP), a surrogate nAChR ligand-binding domain, complexed with the compound and by measuring its actions on wild-type and mutant nematodes and functionally expressed nAChRs. Paraherquamide A showed a higher efficacy for the levamisole-sensitive [L-type (UNC-38/UNC-29/UNC-63/LEV-1/LEV-8)] nAChR than the nicotine-sensitive [N-type (ACR-16)] nAChR, a result consistent with in vivo studies on wild-type worms and worms with mutations in subunits of these two classes of receptors.

β-1,4-Cellobiohydrolase is involved in full expression of phcA, contributing to the feedback loop in quorum sensing of Ralstonia pseudosolanacearum strain OE1-1.

After infecting roots of tomato plants, the gram-negative bacterium Ralstonia pseudosolanacearum strain OE1-1 activates quorum sensing (QS) to induce production of plant cell wall-degrading enzymes, such as β-1,4-endoglucanase (Egl) and β-1,4-cellobiohydrolase (CbhA), via the LysR family transcriptional regulator PhcA and then invades xylem vessels to exhibit virulence. The phcA-deletion mutant (ΔphcA) exhibits neither the ability to infect xylem vessels nor virulence. Compared with strain OE1-1, the egl-deletion mutant (Δegl) exhibits lower cellulose degradation activity, lower infectivity in xylem vessels, and reduced virulence.

Discovery of Cyclic Lipopeptides Ralstopeptins A and B from Species Complex and Analysis of Biosynthetic Gene Evolution.

species complex (RSSC) strains are plant pathogens that produce lipopeptides (ralstonins and ralstoamides) by the polyketide synthase-nonribosomal peptide synthetase (PKS-NRPS) enzyme hybrid. Recently, ralstonins were found to be key molecules in the parasitism of RSSC to other hosts, and fungi. The PKS-NRPS genes of RSSC strains in the GenBank database suggest the production of additional lipopeptides, although it has not been confirmed to date.

Transport Form and Pathway from the Intestine to the Peripheral Tissues and the Intestinal Absorption and Metabolism Properties of Oleamide.

This study aimed to obtain information on the transport form and pathway from the intestine to the peripheral tissues and on the intestinal absorption and metabolism properties of oleamide (-9-octadecenamide). Oleamide was primarily transported via the portal vein. Density gradient centrifugation indicated that plasma oleamide was enriched in the fractions containing albumin in the portal and peripheral blood.

The behavior of Ralstonia pseudosolanacearum strain OE1-1 and morphological changes of cells in tomato roots.

The soil-borne Gram-negative β-proteobacterium Ralstonia solanacearum species complex (RSSC) infects tomato roots through the wounds where secondary roots emerge, infecting xylem vessels. Because it is difficult to observe the behavior of RSSC by a fluorescence-based microscopic approach at high magnification, we have little information on its behavior at the root apexes in tomato roots. To analyze the infection route of a strain of phylotype I of RSSC, R.

Competitive chrodrimanin B interactions with rat brain GABA receptors revealed by radioligand binding assays.

Meroterpenoid compounds chrodrimanins produced by Talaromyces sp. YO-2 have been shown to act as competitive antagonists of silkworm larval GABA receptors using electrophysiology, yet no further evidence has been provided to support such an action. We have investigated the actions of chrodrimanin B on rat brain GABA receptors by binding assays with non-competitive ligand of GABA receptors [H]EBOB and competitive ligands [H]gabazine and [H]muscimol.

Sodium sulfite causes gastric mucosal cell death by inducing oxidative stress.

Sulfites are commonly used as a preservative and antioxidant additives in the food industry. Sulfites are absorbed by the gastrointestinal tract and distributed essentially to all body tissues. Although sulfites have been believed to be safe food additives, some studies have shown that they exhibit adverse effects in various tissues.

The Spiral Trial: A multicenter, randomized, controlled trial of Spiral thread sutures versus conventional thread sutures to prevent thinning of uterine scars following elective cesarean section.

Background: The aim of this randomized controlled trial (RCT) is to investigate whether Spiral-thread sutures are superior to conventional sutures (0-Vicryl) for preventing uterine scar thinning following elective cesarean section.

Methods: This multicenter, parallel-group RCT will be conducted in four hospitals across three medical regions in Japan to assess 200 women (≥20 years old) with singleton pregnancies who are scheduled to undergo cesarean sections. Eligible women will be randomly assigned (1:1 ratio) to receive either the conventional uterine suture continuous absorption thread, which is most commonly used in Japan, or the Spiral thread.

Disproof of the Proposed Structures of Bradyoxetin, a Putative Signaling Molecule, and HMCP, a Putative Quorum-Sensing Molecule.

First, we revisited the reported NMR data of bradyoxetin, a putative cell density factor of , and found some inconsistencies in the proposed structure. To elucidate the correct structure, we synthesized model oxetane compounds and confirmed that the NMR data of the synthetic compounds did not match those of the reported bradyoxetin. After reinterpreting the reported NMR data, we concluded that bradyoxetin must be chloramphenicol.

Chemical genetic approach using β-rubromycin reveals that a RIO kinase-like protein is involved in morphological development in Phytophthora infestans.

To characterize the molecular mechanisms underlying life-stage transitions in Phytophthora infestans, we initiated a chemical genetics approach by screening for a stage-specific inhibitor of morphological development from microbial culture extracts prepared mostly from actinomycetes from soil in Japan. Of the more than 700 extracts, one consistently inhibited Ph. infestans cyst germination.

Quorum Sensing Inhibition Attenuates the Virulence of the Plant Pathogen Species Complex.

Strains of species complex (RSSC) cause "bacterial wilt" on a wide range of plant species and thus lead to marked economic losses in agriculture. Quorum sensing (QS), a bacterial cell-cell communication mechanism, controls the virulence of RSSC strains by regulating the production of extracellular polysaccharide (EPS) and secondary metabolites, biofilm formation, and cellular motility. strain OE1-1 employs ()-methyl 3-hydroxymyristate (3-OH MAME) as a QS signal, which is synthesized by the PhcB methyltransferase and sensed by the PhcS/PhcRQ two-component system.

Oleamide rescues tibialis anterior muscle atrophy of mice housed in small cages.

Skeletal muscle atrophy causes decreased physical activity and increased risk of metabolic diseases. We investigated the effects of oleamide (cis-9,10-octadecanamide) treatment on skeletal muscle health. The plasma concentration of endogenous oleamide was approximately 30 nm in male ddY mice under normal physiological conditions.

Genome- and Mass Spectrometry-Guided Discovery of Ralstoamides A and B from Species Complex.

Strains of species complex (RSSC) are devastating plant pathogens distributed globally with a wide host range and genetic diversity. Many RSSC strains harbor the polyketide synthase-nonribosomal peptide synthetase (PKS-NRPS) hybrid gene / for ralstonin production. We report that ralstoamides A () and B (), which are ralstonin-like but shorter lipopeptides, were discovered from the Japanese strains using accumulated RSSC genome data and LC/MS-based metabolite analysis.