A mannose-sensing AraC-type transcriptional activator regulates cell-cell aggregation of Vibrio cholerae.

In addition to catalyzing coupled transport and phosphorylation of carbohydrates, the phosphoenolpyruvate:carbohydrate phosphotransferase system (PTS) regulates various physiological processes in most bacteria. Therefore, the transcription of genes encoding the PTS is precisely regulated by transcriptional regulators depending on substrate availability. As the distribution of the mannose-specific PTS (PTSMan) is limited to animal-associated bacteria, it has been suggested to play an important role in host-bacteria interactions. In Vibrio cholerae, mannose is known to inhibit biofilm formation. During host infection, the transcription level of the V. cholerae gene encoding the putative PTSMan (hereafter referred to as manP) significantly increases, and mutations in this gene increase host survival rate. Herein, we show that an AraC-type transcriptional regulator (hereafter referred to as ManR) acts as a transcriptional activator of the mannose operon and is responsible for V. cholerae growth and biofilm inhibition on a mannose or fructose-supplemented medium. ManR activates mannose operon transcription by facilitating RNA polymerase binding to the promoter in response to mannose 6-phosphate and, to a lesser extent, to fructose 1-phosphate. When manP or manR is impaired, the mannose-induced inhibition of biofilm formation was reversed and intestinal colonization was significantly reduced in a Drosophila melanogaster infection model. Our results show that ManR recognizes mannose and fructose in the environment and facilitates V. cholerae survival in the host.

Eupatilin treatment inhibits transforming growth factor beta-induced endometrial fibrosis in vitro.

OBJECTIVE: Endometrial fibrosis, the primary pathological feature of intrauterine adhesion, may lead to disruption of endometrial tissue structure, menstrual abnormalities, infertility, and recurrent pregnancy loss. At present, no ideal therapeutic strategy exists for this fibrotic disease. Eupatilin, a major pharmacologically active flavone from Artemisia, has been previously reported to act as a potent inducer of dedifferentiation of fibrotic tissue in the liver and lung. However, the effects of eupatilin on endometrial fibrosis have not yet been investigated. In this study, we present the first report on the impact of eupatilin treatment on transforming growth factor beta (TGF-ß)-induced endometrial fibrosis. METHODS: The efficacy of eupatilin on TGF-ß-induced endometrial fibrosis was assessed by examining changes in morphology and the expression levels of fibrosis markers using immunofluorescence staining and quantitative real-time reverse-transcription polymerase chain reaction. RESULTS: Eupatilin treatment significantly reduced the fibrotic activity of TGF-ß-induced endometrial fibrosis in Ishikawa cells, which displayed more circular shapes and formed more colonies. Additionally, the effects of eupatilin on fibrotic markers including alpha-smooth muscle actin, hypoxia-inducible factor 1 alpha, collagen type I alpha 1 chain, and matrix metalloproteinase-2, were evaluated in TGF-ß-induced endometrial fibrosis. The expression of these markers was highly upregulated by TGF-ß pretreatment and recovered to the levels of control cells in response to eupatilin treatment. CONCLUSION: Our findings suggest that suppression of TGF-ß-induced signaling by eupatilin might be an effective therapeutic strategy for the treatment of endometrial fibrosis.

Enantioseparation of N-fluorenylmethoxycarbonyl alpha-amino acids on polysaccharide-derived chiral stationary phases by reverse mode liquid chromatography.

The enantioseparation of N-protected fluorenylmethoxycarbonyl (N-FMOC) alpha-amino acids was carried out on three polysaccharide-derived chiral stationary phases, such as cellulose tris(3,5-dimethylphenylcarbamate) (Chiralcel OD), amylose tris(3,5-dimethyl-phenylcarbamate) (Chiralpak AD) and cellulose tris(4-methylbenzoate) (Chiralcel OJ), and the influence of acetonitrile composition and pH of the eluents on the enantioseparation in reverse mode chromatography was examined. The best separation of the enantiomers was achieved with 40% acetonitrile in 50mM phosphate buffer at pH 2. However, increasing the composition of acetonitrile to 50% on Chiralcel OD yielded a considerable decrease of retention time with minimum loss of resolution. The elution order of N-FMOC alpha-amino acid enantiomers on Chiralcel OD and OJ were quite different, indicating that both phases could be used in a complementary manner for the separation of the enantiomers of N-FMOC alpha-amino acids. The positive relationship between the capacity factor of N-FMOC alpha-amino acids and the hydrophobicity of amino acids indicated that hydrophobicity plays an important role on the retention of the N-FMOC alpha-amino acids in the reverse mode.

Capillary electrophoretic method for the determination of diterpenoid isomers in Acanthopanax species.

Acanthoic, continentalic and kaurenoic acids are bioactive diterpenoids that are structural isomers isolated from Acanthopanax species. Due to the interest in their potent biological activity, an analytical method of diterpenoids was developed for the quality control and the classification of Acanthopanax species. Capillary electrophoresis was used to separate and quantify the isomers. The three compounds were successfully separated from each other and from the matrices in the extracts of leaves, stems and roots of Acanthopanax species. The contents of acanthoic, continentalic and kaurenoic acids showed taxonomical differences in Acanthopanax species. Relatively higher concentrations of diterpenoids were found from A. koreanum and A. trifoliatus, while only trace amounts were found from the four other species tested: A. senticosus, A. senticosus f. inermis, A. chiisanensis, and A. divaricatus var. albeofructus. The contents of diterpenoids in association with lignans and triterpenoids in the Acanthopanax species could provide a chemotaxonomical index able to be used in the classification and discrimination of the species.