Comparative genomic analysis of the coding sequences (CDSs) of Leptospira interrogans revealed a pair of closely linked genes homologous to the vapBC loci of many other bacteria with respect to both deduced amino acid...Comparative genomic analysis of the coding sequences (CDSs) of Leptospira interrogans revealed a pair of closely linked genes homologous to the vapBC loci of many other bacteria with respect to both deduced amino acid sequences and operon organizations. Expression of single vapC gene in Escherichia coli resulted in inhibition of bacterial growth,whereas co-expression of vapBC restored the growth effectively. This phenotype is typical for three other characterized toxin-antitoxin systems of bacteria, i.e., mazEF[1], relBE[2] and chpIK[3]. The VapC proteins of bacteria and a thermophilic archeae, Solfolobus tokodaii, form a structurally distinguished group of toxin different from the other known toxins of bacteria. Phylogenetic analysis of both toxins and antitoxins of all categories indicated that although toxins were evolved from divergent sources and may or may not follow their speciation paths (as indicated by their 16s RNA sequences), co-evolution with their antitoxins was obvious.展开更多
Resveratrol (3, 5, 4'-trihydroxystilbene) (RV) is a constituent of grape seeds with anti-inflammatory andanti-oxidant activities. In this study, we examined the capacity of RV to modulate the function of Gprotein-...Resveratrol (3, 5, 4'-trihydroxystilbene) (RV) is a constituent of grape seeds with anti-inflammatory andanti-oxidant activities. In this study, we examined the capacity of RV to modulate the function of Gprotein-coupled chemoattractant receptors, which play important roles in inflammation and immune responses.RV, over a non-cytotoxic concentration range, inhibited chemotactic and calcium mobilization responses ofphagocytic cells to selected chemoattractants. At low micromolar concentrations,RV potently reducedsuperoxide anion production by phagocytic leukocytes in response to the bacterial chemotactic peptide fMLF, ahigh affinity ligand for formylpeptide receptor FPR, and Ap.4z, an Alzheimer's disease-associated peptide and aligand for the FPR variant FPRL1. In addition, RV reduced phosphorylation of extracellular signal-regulatedkinase (ERK1/2) and the activation of nuclear factor NF-KB induced by formylpeptide receptor agonists. Theseresults suggest that the inhibition of the function of chemoattractant receptors may contribute to theanti-inflammatory properties of RV Thus, RV may be therapeutically promising for diseases in which activationof formylpeptide receptors contributes to the pathogenic processes. Cellular&Molecular Immunology. 2004;1(1):50-56.展开更多
基金This work was supported by the National High Technology Research and Development Program of China(Program No.2003AA223031).
文摘Comparative genomic analysis of the coding sequences (CDSs) of Leptospira interrogans revealed a pair of closely linked genes homologous to the vapBC loci of many other bacteria with respect to both deduced amino acid sequences and operon organizations. Expression of single vapC gene in Escherichia coli resulted in inhibition of bacterial growth,whereas co-expression of vapBC restored the growth effectively. This phenotype is typical for three other characterized toxin-antitoxin systems of bacteria, i.e., mazEF[1], relBE[2] and chpIK[3]. The VapC proteins of bacteria and a thermophilic archeae, Solfolobus tokodaii, form a structurally distinguished group of toxin different from the other known toxins of bacteria. Phylogenetic analysis of both toxins and antitoxins of all categories indicated that although toxins were evolved from divergent sources and may or may not follow their speciation paths (as indicated by their 16s RNA sequences), co-evolution with their antitoxins was obvious.
文摘Resveratrol (3, 5, 4'-trihydroxystilbene) (RV) is a constituent of grape seeds with anti-inflammatory andanti-oxidant activities. In this study, we examined the capacity of RV to modulate the function of Gprotein-coupled chemoattractant receptors, which play important roles in inflammation and immune responses.RV, over a non-cytotoxic concentration range, inhibited chemotactic and calcium mobilization responses ofphagocytic cells to selected chemoattractants. At low micromolar concentrations,RV potently reducedsuperoxide anion production by phagocytic leukocytes in response to the bacterial chemotactic peptide fMLF, ahigh affinity ligand for formylpeptide receptor FPR, and Ap.4z, an Alzheimer's disease-associated peptide and aligand for the FPR variant FPRL1. In addition, RV reduced phosphorylation of extracellular signal-regulatedkinase (ERK1/2) and the activation of nuclear factor NF-KB induced by formylpeptide receptor agonists. Theseresults suggest that the inhibition of the function of chemoattractant receptors may contribute to theanti-inflammatory properties of RV Thus, RV may be therapeutically promising for diseases in which activationof formylpeptide receptors contributes to the pathogenic processes. Cellular&Molecular Immunology. 2004;1(1):50-56.
