Effect of the urease accessory genes on activation of the Helicobacter pylori urease apoprotein.

The roles that accessory gene products play in activating the Helicobacter pylori urease apoprotein were examined. The activity of the urease apoprotein increased in the following order when it was expressed with the accessory genes: ureG

Anti-inflammatory effects of 5-hydroxy-3,6,7,8,3',4'-hexamethoxyflavone via NF-κB inactivation in lipopolysaccharide-stimulated RAW 264.7 macrophage.

The anti-inflammatory mechanism of 5-hydroxy-3,6,7,8,3',4'-hexamethoxyflavone (5HHMF), a polyhydroxyflavone isolated from the marine algae Hizikia fusiforme, was investigated in RAW 264.7 murine macrophage cells. Western blot and reverse transcriptase PCR analyses indicated that adding 5HHMF to cultured cells significantly reduced the production of nitric oxide and prostaglandin E2 and downregulated inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. In addition, 5HHMF inhibited the release of pro-inflammatory cytokines, such as tumor necrosis factor-α and interleukin-1ß, and decreased the transcriptional levels. In particular, 5HHMF significantly inhibited the LPS-induced nuclear factor-κB (NF-κB) translocation from the cytosol to the nucleus, which was associated with the abrogation of inhibitory IκBα degradation and subsequent decreases in nuclear p65 levels. In conclusion, these results suggested that the anti-inflammatory activities of 5HHMF may be attributed to the inhibition of iNOS, COX-2 and cytokine expression by attenuating NF-κB activation via IκBα degradation in macrophages.

Effect of cordycepin on the expression of the inflammatory cytokines TNF-alpha, IL-6, and IL-17A in C57BL/6 mice.

Culture supernatants of splenocytes from C57BL/6 mice were exposed to 0.3, 1.0, and 3.0 microg/ml cordycepin plus 3.0 microg/ml lipopolysaccharide (LPS) to investigate the effects of cordycepin (3'-deoxyadenosine) on the production of inflammatory cytokines. Co-administration of 3.0 microg/ml cordycepin with LPS in cultured murine spleen cells significantly diminished the expression of the inflammatory cytokines tumor necrosis factor-alpha and interleukin-6 (IL-6) in a time-dependent manner. Expression of the inflammatory cytokine IL-17A was substantially down-regulated in a time- dependent manner at all cordycepin concentrations. These findings suggest that cordycepin down-regulates the immediate hypersensitivity reaction stimulated by LPS.

Apoptosis induction of human prostate carcinoma cells by cordycepin through reactive oxygen species­mediated mitochondrial death pathway.

Cordycepin is the main functional component of Cordyceps militaris, which has been widely used in oriental traditional medicine. This compound has been shown to possess many pharmacological properties, such as enhancing the body's immune function, and anti-inflammatory, anti-aging and anticancer effects. In the present study, we investigated the apoptotic effects of cordycepin in human prostate carcinoma cells. We found that treatment with cordycepin significantly inhibited cell growth by inducing apoptosis in PC-3 cells. Apoptosis induction of PC-3 cells by cordycepin showed correlation with proteolytic activation of caspase-3 and -9, but not caspase-8, and concomitant degradation of poly (ADP-ribose) polymerases, collapse of the mitochondrial membrane potential (MMP). In addition, cordycepin treatment resulted in an increase of the Bax/Bcl-2 (or Bcl-xL) ratio, downregulation of inhibitor of apoptosis protein (IAP) family members, Bax conformational changes, and release of cytochrome c from the mitochondria to the cytosol. The cordycepin-induced apoptosis was also associated with the generation of intracellular reactive oxygen species (ROS). However, the quenching of ROS generation with antioxidant N-acetyl-L-cysteine conferred significant protection against cordycepin-elicited ROS generation, disruption of the MMP, modulation of Bcl-2 and IAP family proteins, caspase-3 and -9 activation and apoptosis. This indicates that the cellular ROS generation plays a pivotal role in the initiation of cordycepin-triggered apoptotic death. Collectively, our findings suggest that cordycepin is a potent inducer of apoptosis of prostate cancer cells via a mitochondrial-mediated intrinsic pathway and that this agent may be of value in the development of a potential therapeutic candidate for both the prevention and treatment of cancer.

Identification of 5-hydroxy-3,6,7,8,3´,4´-hexamethoxyflavone from Hizikia fusiforme involved in the induction of the apoptosis mediators in human AGS carcinoma cells.

An 80% ethanol extract of Hizikia fusiforme was obtained and followed by successive fractionation using the organic solvents n-hexane, ethyl acetate, and n-butanol to identify the antioxidative substance. The aqueous part of the nbutanol fractionation step, showing high antioxidative activity, was subjected to reverse-phase liquid chromatography. As a result, a substance purified from a BB-2 fraction showed high antioxidative activity. The m/z 419 [M+H] molecular ion peak in the fraction was observed by the analysis of the ESI-LC/MS spectrum. By the analysis of 1H NMR (500 MHz, DMSO-d6) and 13C NMR (125 MHz, DMSO-d6) spectra, a unique compound of the fraction was biochemically identified as a 5-hydroxy-3,6,7,8,3´,4´- hexamethoxyflavone (5HHMF). We also investigated the effect of 5HHMF on human gastric AGS carcinoma cells. Western blot analysis suggested that the flavone substantially increased the levels of the death receptor-associated apoptosis mediators Fas, Fas L, FADD, TRADD, and DR4 in a concentration-dependent manner. The levels of Fas, Fas L, TRADD, and DR4 in the cells treated with 5HHMF (5 microgram/ml) were approximately 26.4-, 12.8-, 6.7-, and 9.8- times higher than those of non-treated cells, respectively. Of note, the level of FADD protein in the cells exposed to 5HHMF (1 microgram/ml) increased approximately 9.6-times. In addition, the cleavage of caspase-3, -8, and -9 in cultured AGS cells treated with 5HHMF was significantly confirmed. Therefore, our results suggest that 5HHMF from H. fusiforme is involved in the induction of death receptor-associated apoptosis mediators in human gastric AGS carcinoma cells.

Effect of cordycepin purified from Cordyceps militaris on Th1 and Th2 cytokines in mouse splenocytes.

Cordycepin was purified from a mushroom, Cordyceps militaris, and its effect on Th1 and Th2 cytokines was examined. The level of cytokine induction in mouse splenocytes was estimated after co-inoculation of purified cordycepin and LPS. When 5 microg/ml of purified cordycepin was exposed to mouse splenocytes for 72 h, the level of a Th1 cytokine IL-12 increased by 2.9-fold. The addition of the purified cordycepin to splenocytes also increased the level of Th2 cytokines, IL-4 and IL-10, by 1.9- and 1.8- fold, respectively. Therefore, cordycepin increases the cytokine levels and may contribute to the up-regulation of cellular and humoral immunity.

Biochemical characterization of the exopolysaccharide purified from Laetiporus sulphureus mycelia.

The extracellular polysaccharide (EPS) was isolated from mycelial cultures of Laetiporus sulphureus var. miniatus and purified by DEAE cellulose and Sephadex G-50 column chromatography. The purified EPS (EPS-2-1) was composed of only glucose units and its molecular mass was 6.95 kDa. The chemical structure of EPS-2-1 consisted of a main chain containing (1-->4)-Glcp units with branches at the C-6 position of the chain carrying -Glcp-(1-->4)-linked residues. The effect of purified EPS on immunomodulatory genes and proteins of the Bcl-2 family was observed using cultured U937 human leukemia cells. Of note, the levels of Bax and Bad proteins treated with the EPS (4 mg/ml) were approximately 23- and 18-times higher than those in non-treated cells, respectively. These results may suggest that the EPS purified from the mushroom L. sulphureus is associated with the activation of immunomodulatory mediators, Bax and Bad proteins.

Biochemical analysis of a fibrinolytic enzyme purified from Bacillus subtilis strain A1.

A fibrinolytic enzyme from Bacillus subtilis strain Al was purified by chromatographic methods, including DEAE Sephadex A-50 column chromatography and Sephadex G-50 column gel filtration. The purified enzyme consisted of a monomeric subunit and was estimated to be approximately 28 kDa in size by SDS-PAGE. The specific activity of the fibrinolytic enzyme was 1632-fold higher than that of the crude enzyme extract. The fibrinolytic activity of the purified enzyme was approximately 0.62 and 1.33 U/ml in plasminogen-free and plasminogen-rich fibrin plates, respectively. Protease inhibitors PMSF, DIFP, chymostatin, and TPCK reduced the fibrinolytic activity of the enzyme to 13.7, 35.7, 15.7, and 23.3%, respectively. This result suggests that the enzyme purified from B. subtilis strain Al was a chymotrypsin-like serine protease. In addition, the optimum temperature and pH range of the fibrinolytic enzyme were 50°C and 6.0-10.0, respectively. The N-terminal amino acid sequence of the purified enzyme was identified as Q-T-G-G-S-I-I-D-P-I-N-G-Y-N, which was highly distinguished from other known fibrinolytic enzymes. Thus, these results suggest a fibrinolytic enzyme as a novel thrombolytic agent from B. subtilis strain Al.

Detection of a unique fibrinolytic enzyme in Aeromonas sp. JH1.

A fibrinolytic enzyme was found in a Gram-negative bacterium, Aeromonas sp. JH1. SDS-PAGE and fibrinzymography showed that it was a 36 kDa, monomeric protein. Of note, the enzyme was highly specific for fibrinogen molecules and the hydrolysis rate of fibrinogen subunits was highest for α, ß, and γ chains in that order. The first 15 amino acids of N-terminal sequence were X-D-A-T-G-P-G-G-N-V-X-T-G-K-Y, which was distinguishable from other fibrinolytic enzymes. The optimum pH and temperature of the enzyme were approximately 8.0 and 40°C, respectively. Therefore, these results provide a fibrinolytic enzyme with potent thrombolytic activity from the Aeromonas genus.

Purification and biochemical characterization of a 17 kDa fibrinolytic enzyme from Schizophyllum commune.

A fibrinolytic enzyme of the mushroom, Schizophyllum commune was purified with chromatographic methods, including a DEAE-Sephadex A-50 ion-exchange column and gel filtrations with Sephadex G-75 and Sephadex G-50 columns. The analysis of fibrin-zymography and SDS-PAGE showed that the enzyme was a monomeric subunit that was estimated to be approximately 17 kDa in size. The fibrinolytic activity of the enzyme in plasminogen-rich and plasminogen-free fibrin plates was 1.25 and 0.44 U/ml, respectively. The N-terminal amino acid sequence of the purified enzyme was identified as HYNIXNSWSSFID, which was highly distinguished from known fibrinolytic enzymes. The relative activity of the purified enzyme with an addition of 5 mM EDTA, Phosphoramidon, and Bestatin was about 76, 64, and 52%, respectively, indicating that it is a metalloprotease. The optimum temperature for the purified enzyme was approximately 45°C, and over 87% of the enzymatic activity was maintained as a stable state in a pH range from 4.0 to 6.0. Therefore, our results suggest that the potential thrombolytic agent from S. commune is a unique type of fibrinolytic enzyme.

Initial acidic pH is critical for mycelial cultures and functional exopolysaccharide production of an edible mushroom, Laetiporus sulphureus var. miniatus JM 27.

We conducted a time course experiment on mycelial cultures of Laetiporus sulphureus var. miniatus. The strain showed significant survival in an initial pH range of 2.0 to 7.0 for 24 days, during which time oxalic acid was accumulated. A structural analysis of purified exopolysaccharide suggested that it contained 96.1% glucose, and the mode of linkage was mainly → 4-Glcp-(1 → units, with branches at the C-6 position consisting of a Glcp-(1 → 4) linked side chain. An exopolysaccharide purified from the acidophilic strain was added to cultured U937 cells, resulting in significantly increased transcription levels of p53 and p21 genes.

Quantitative analysis of representative proteome components and clustering of Helicobacter pylori clinical strains.

BACKGROUND: Several Helicobacter pylori proteins have been reported to be associated with severe symptoms of gastric disease. However, expression levels of most of these disease-associated proteins require further evaluation in order to clarify their relationships with gastric disease patterns. Representative proteome components of 71 clinical isolates of H. pylori were analyzed quantitatively to determine whether the protein expression levels were associated with gastric diseases and to cluster clinical isolates. METHODS: After two-dimensional electrophoresis (2-DE) of H. pylori isolates, spot intensities were analyzed using pdquest 2-D Gel Analysis Software. The intensities of 10 representative protein spots, identified by peptide fingerprinting using matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS) or peptide sequencing using quadrupole TOF MS, were subjected to the nonparametric Mann-Whitney test and hierarchical agglomerative cluster analysis. The relationship between clusters and gastric diseases was analyzed by the chi-squared test. RESULTS: Although the spot intensities of the 10 representative proteins were highly variable within each gastric disease group, the expression levels of CagA, UreB, GroEL, EF-Tu, EF-P, TagD, and FldA showed some significant differences among the gastric disease patterns. On the basis of the 10 target protein intensities, hierarchical agglomerative cluster analysis generated a dendrogram with clusters indicative of chronic gastritis/gastric cancers and gastric/duodenal ulcers. CONCLUSION: These results indicated that quantitative analysis of proteome components is a feasible method for examining disease-associated proteins and clustering clinical strains of H. pylori.

Purification of a fibrinolytic enzyme (myulchikinase) from pickled anchovy and its cytotoxicity to the tumor cell lines.

A fibrinolytic enzyme, myulchikinase, from a Korean seasoning ingredient, myul-chi-jeot-gal, has been purified to electrophoretic homogeneity. The molecular mass of the myulchikinase was estimated to about 28 kDa by SDS-PAGE and gel filtration. Amino acid sequence of the NH2-terminal of myulchikinase showed significant homology with other fibrinolytic enzymes including trypsin from starfish, katsuwokinase, and rat pancreatic elastase II. The purified myulchikinase hydrolyzed various synthetic substrates with different substrate specificity and cytotoxic to the tumor cell lines.

pHP489, a Helicobacter pylori small cryptic plasmid, harbors a novel gene coding for a replication initiation protein.

We have analyzed a Helicobacter pylori plasmid, pHP489. The 1222-bp nucleotide sequence had one open reading frame, a DnaA-binding site, one direct repeat, and three inverted repeats. The (G+C) content of pHP489 was 33.3%. Although the nucleic acid sequence and deduced amino acid sequence were homologous to those of other bacterial plasmid Rep proteins, the degree of similarity was very low. A deletion analysis showed that the Rep protein was not required for the replication of pHP489 in its H. pylori host, but the host replication machinery was needed.

Proteomic analysis of the sarcosine-insoluble outer membrane fraction of Helicobacter pylori strain 26695.

Helicobacter pylori causes gastroduodenal disease, which is mediated in part by its outer membrane proteins (OMPs). To identify OMPs of H. pylori strain 26695, we performed a proteomic analysis. A sarcosine-insoluble outer membrane fraction was resolved by two-dimensional electrophoresis with immobilized pH gradient strips. Most of the protein spots, with molecular masses of 10 to 100 kDa, were visible on the gel in the alkaline pI regions (6.0 to 10.0). The proteome of the OMPs was analyzed by matrix-assisted laser desorption ionization-time-of-flight mass spectrometry. Of the 80 protein spots processed, 62 spots were identified; they represented 35 genes, including 16 kinds of OMP. Moreover, we identified 9 immunoreactive proteins by immunoblot analysis. This study contributes to the characterization of the H. pylori strain 26695 proteome and may help to further elucidate the biological function of H. pylori OMPs and the pathogenesis of H. pylori infection.

Characterization of a small cryptic plasmid, pHP51, from a Korean isolate of strain 51 of Helicobacter pylori.

The nucleotide sequence of a 3955-bp Helicobacter pylori plasmid, pHP51 was determined, and two open reading frames, ORF1 and ORF2, were identified. The deduced amino acid sequence of ORF1 was highly conserved (87-89%) among plasmid replication initiation proteins, RepBs. The function of ORF2 was not assigned because it lacked known functional domains or sequence similarity with other known proteins, although it had a HPFXXGNG motif that was also found in the cAMP-induced filamentation (fic) gene. Three kinds of repeats were present on the plasmid outside of the ORFs, including the R1 and R2 repeats that are common in H. pylori plasmids. One 100-bp sequence detected in the noncoding region of pHP51 was highly similar to the genomic sequence of H. pylori 26695.

Identifying the major proteome components of Helicobacter pylori strain 26695.

The whole genome sequences of Helicobacter pylori strain 26695 have been reported. Whole cell proteins of H. pylori strain 26695 cells were obtained and analyzed by two-dimensional electrophoresis, using immobilized pH gradient strips. The most abundant proteins were shown in the region of pI 4.0-9.5 with molecular masses from 10 to 100 kDa. Soluble proteins were precipitated by the use of 0-80% saturated solutions of ammonium sulfate. Soluble proteins precipitated by the 0-40% saturations of ammonium sulfate produced similar spot profiles and their abundant protein spots had acidic pI regions. However, a number of soluble proteins precipitated by more than 60% saturation of ammonium sulfate were placed in the alkaline pI regions, compared to those precipitated by 40% saturation. In addition, we have performed an extensive proteome analysis of the strain utilizing peptide MALDI-TOF-MS. Among the 345 protein spots processed, 175 proteins were identified. The identified spots represented 137 genes. One-hundred and fifteen proteins were newly identified in this study, including DNA polymerase III beta-subunit. These results might provide guidance for the enrichment of H. pylori proteins and contribute to construct a master protein map of H. pylori.