18ß-glycyrrhetinic Acid Modulated Autophagy is Cytotoxic to Breast Cancer Cells.

The development of endocrine therapy resistance in the luminal A subtype of breast cancer is related to the appearance of protective autophagy. The bioactive component from the root of licorice, 18ß-glycyrrhetinic acid (18ß-GA), has many antitumor properties. Whether 18ß-GA can modulate autophagy to inhibit proliferation of the luminal A subtype is still unclear. The proportion of apoptosis caused by 18ß-GA in MCF-7 and T-47D cells was determined using flow cytometry. The autophagy marker, LC3-II conversion, was investigated using Western blotting, and a PremoTM Tandem Autophagy Sensor Kit. We found that the concentration (150-µM) of 18ß-GA caused caspase-dependent apoptosis and LC3-II accumulation or blocked autophagic flux. Moreover, 18ß-GA-mediated apoptosis was improved using rapamycin but reversed by 3-methyladenine (3-MA) addition. The phosphorylation level of Jun-amino-terminal kinase (JNK) was increased significantly in the 18ß-GA treatment and combined incubation using rapamycin. A JNK inhibitor (SP600125) significantly inhibited 18ß-GA-mediated apoptosis, LC3-II accumulation and rescued the numbers of MCF-7 and T-47D colony formation. Especially, 18ß-GA can inhibit xenograft tumor growth in BALB/c nude mice. These data indicate the combination of 18ß-GA with rapamycin or 3-MA can sensitize or decrease MCF-7 and T-47D cells to 18ß-GA-induced apoptosis, respectively. 18ß-GA modulated autophagy is cytotoxic to luminal A subtype breast cancer cells through apoptosis promotion and JNK activation.

Lipofundin mediates major inhibition of intravenous propofol on phorbol myristate acetate and Escherichia coli-induced neutrophil extracellular traps.

BACKGROUND: Neutrophil extracellular traps (NETs) consist of chromatin DNA networks that are studded with cytosolic and granular antimicrobial proteins to trap or kill an infected microorganism. A lipid emulsion, the solvent of pure propofol for intravenous application, is given to clinical patients who require intravenous feeding of fatty acids and fat for energy. Intravenous propofol is widely used to sedate critically ill patients. Both intravenous propofol and its lipid emulsion have immunomodulatory activity. However, the role of lipid emulsion of intravenous propofol on NET induction remains unclear. METHODS: In this study, neutrophils were stimulated with phorbol myristate acetate (PMA) or Escherichia coli (E. coli) in the absence or presence of intravenous propofol (Propofol-Lipuro®), its solvent lipid emulsion (Lipofundin) or pure propofol, and NETs were stained with SYTOX Green for visualization and quantification. Total HOCl was determined by measuring the taurine-chloramine complex, and intracellular HOCl was evaluated with BioTracker™ TP-HOCl 1 dye. RESULTS: PMA-induced NETs were not efficiently inhibited when Propofol-Lipuro® was added after PMA stimulation. Clinically relevant concentrations of Lipofundin exerted a significant reduction in PMA-induced NETs and total reactive oxidative species (ROS), which was comparable to that observed for Propofol-Lipuro®. Lipofundin transiently reduced intracellular HOCl production and the phosphorylation level of extracellular regulated kinase (p-ERK) but did not scavenge HOCl. Moreover, Lipofundin decreased E. coli-induced NETs in a ROS-independent pathway, similar to Propofol-Lipuro®. CONCLUSIONS: All data agree that Lipofundin, the major component of Propofol-Lipuro®, inhibits intracellular HOCl and p-ERK to suppress PMA-induced NET formation but reduces E.coli-induced NETs in a ROS-independent pathway.

Three Lipid Emulsions Reduce Staphylococcus aureus-Stimulated Phagocytosis in Mouse RAW264.7 Cells.

Soybean oil (SO)-, SO medium-chain triglyceride (MCT)-, olive oil (OO)-, and fish oil (FO)-based lipid emulsions are generally applied in clinical practice via intravenous injection for patients with nutritional requirements. The function of lipid emulsions on immune modulation remains inconsistent, and their effects on macrophages are limited. In the present study, we used a model of S. aureus-infected mouse RAW264.7 macrophages to determine the influence of three different compositions of lipid emulsions (Lipofundin, ClinOleic, and Omegaven) on reactive oxygen species (ROS) production, phagocytosis, and bacterial survival. The three individual lipid emulsions similarly enhanced bacterial survival but reduced S. aureus-stimulated ROS, phagocytosis of S. aureus bioparticles conjugate, polymerization of F-actin, and phosphorylation of AKT, JNK, and ERK. Compared with the JNK and ERK inhibitors, the PI3K inhibitor markedly suppressed the phagocytosis of S. aureus bioparticles conjugate and the polymerization of F-actin, whereas it significantly increased the bacterial survival. These results suggest that the three lipid emulsions diminished ROS production and phagocytosis, resulting in increased bacterial survival. PI3K predominantly mediated the inhibitory effects of the lipid emulsions on the phagocytosis of mouse RAW264.7 macrophages.

Flavopereirine Inhibits Autophagy via the AKT/p38 MAPK Signaling Pathway in MDA-MB-231 Cells.

Autophagy is a potential target for the treatment of triple negative breast cancer (TNBC). Because of a lack of targeted therapies for TNBC, it is vital to find optimal agents that avoid chemoresistance and metastasis. Flavopereirine has anti-proliferation ability in cancer cells, but whether it regulates autophagy in breast cancer cells remains unclear. A Premo™ Tandem Autophagy Sensor Kit was used to image the stage at which flavopereirine affects autophagy by confocal microscopy. A plasmid that constitutively expresses p-AKT and siRNA targeting p38 mitogen-activated protein kinase (MAPK) was used to confirm the related signaling pathways by Western blot. We found that flavopereirine induced microtubule-associated protein 1 light chain 3 (LC3)-II accumulation in a dose- and time-dependent manner in MDA-MB-231 cells. Confocal florescent images showed that flavopereirine blocked autophagosome fusion with lysosomes. Western blotting showed that flavopereirine directly suppressed p-AKT levels and mammalian target of rapamycin (mTOR) translation. Recovery of AKT phosphorylation decreased the level of p-p38 MAPK and LC3-II, but not mTOR. Moreover, flavopereirine-induced LC3-II accumulation was partially reduced in MDA-MB-231 cells that were transfected with p38 MAPK siRNA. Overall, flavopereirine blocked autophagy via LC3-II accumulation in autophagosomes, which was mediated by the AKT/p38 MAPK signaling pathway.

Lipofundin Mediates the Major Inhibition of Intravenous Propofol in IL-1ß Secretion and Phagocytosis of Staphylococcus aureus-Infected Macrophages.

Lipofundin is the solvent for propofol in the intravenous injection of Propofol-Lipuro® and is used in patients who need intravenous feeding to provide fatty acids and fat for energy. In addition to propofol, Lipofundin also affects the immune modulation of phagocytes. In a previous study, we reported that intravenous propofol effectively decreased Staphylococcus aureus-stimulated reactive oxygen species (ROS) levels, IL-1ß secretion, and phagocytosis in RAW264.7 macrophages. It is important to separately assess the effects of pure propofol, Lipofundin, and Propofol-Lipuro. By using an S. aureus-infected RAW264.7 macrophage model, the levels of secreted IL-1ß in cell supernatants were determined by ELISA. IL-1ß mRNA in cell pellets was further analyzed by quantitative polymerase chain reaction (qPCR), and Western blotting was performed to detect pro-IL-1ß synthesis. Total ROS levels were determined by a luminol chemiluminescence assay. Compared with pure propofol, treatment with clinically relevant concentrations of Propofol-Lipuro and Lipofundin obviously reduced IL-1ß secretion (>85% inhibition), S. aureus-stimulated ROS production (50% inhibition), and phagocytosis (>60% inhibition) to similar levels. Treatment with pure propofol alone significantly decreased IL-1ß mRNA levels and pro-IL-1ß protein synthesis, and slightly inhibited phagocytosis. In contrast, treatment with Propofol-Lipuro did not influence IL-1ß mRNA or pro-IL-1ß protein expression, even though treatment with Lipofundin increased the levels of both IL-1ß mRNA and its precursor protein. In conclusion, IL-1ß secretion is regulated at the posttranslational level. Lipofundin mediated the major effect of Propofol-Lipuro on the inhibition of IL-1ß secretion, ROS production, and phagocytosis in S. aureus-infected RAW264.7 cells.

Flavopereirine induces cell cycle arrest and apoptosis via the AKT/p38 MAPK/ERK1/2 signaling pathway in human breast cancer cells.

Breast cancer, which is the most frequently diagnosed cancer, is quite heterogeneous. For breast cancer subtypes lacking targeted therapies, it is vitally essential to find novel agents that prevent chemoresistance and metastatic relapse. Flavopereirine is a ß-carboline alkaloid that has antiplasmodial activity, and its antiproliferative effect in different cancers remains unclear. The effect of flavopereirine on cell cycle arrest and apoptosis signaling in breast cancer cells was analyzed by flow cytometry. An inhibitor and siRNA were used to confirm the related signaling pathways by Western blot analysis. We found that flavopereirine caused G0/G1 phase arrest in MCF-7 cells and S phase arrest in MDA-MB-231 cells. MDA-MB-231 cells were more sensitive to flavopereirine-induced apoptosis. Furthermore, we found that flavopereirine-induced apoptosis was partially reduced in MDA-MB-231 cells treated with an extracellular regulated kinase (ERK) inhibitor and p38 mitogen-activated protein kinase (MAPK) siRNA. Moreover, p38 siRNA treatment simultaneously reduced phosphorylated ERK expression levels. Conversely, the recovered phosphorylation of AKT decreased the levels of p-ERK and p-p38 MAPK. Overall, flavopereirine induces cell cycle arrest and the AKT/p38 MAPK/ERK signaling pathway, which contribute to flavopereirine-induced apoptosis in MDA-MB-231 cells.

Propofol specifically reduces PMA-induced neutrophil extracellular trap formation through inhibition of p-ERK and HOCl.

Neutrophil extracellular traps (NETs) are net-like chromatin fibers that can trap and kill microorganisms. Although several anti-inflammatory effects of intravenous anesthetics have been reported, it has not been investigated whether intravenous anesthetics influence NET formation. AIMS: To compare the effects of four intravenous anesthetics (propofol, thiamylal sodium, midazolam, and ketamine) on phorbol myristate acetate (PMA)-induced NET formation and analyze the associated signaling pathways. MATERIALS AND METHODS: PMA-stimulated NETs formed in the absence or presence of intravenous anesthetics were stained with SYTOX Green and then quantified. Inhibitors were applied to investigate the related mechanism, which was confirmed by western blotting, and ROS were detected. KEY FINDINGS: The neutrophils incubated with propofol showed the lowest degree of NET formation compared with those incubated with the other intravenous anesthetics. Propofol significantly reduced the level of myeloperoxidase (MPO)-derived HOCl but not that of superoxide. Aminopyrine, an MPO inhibitor, markedly decreased the number of PMA-induced NETs, indicating the involvement of HOCl in the inhibitory effect of propofol on NET formation. According to western blotting results, the level of p-ERK was reduced by propofol during PMA-induced NET formation. The ERK inhibitor PD98059 decreased NET formation but did not inhibit PMA-induced HOCl generation, and aminopyrine did not reduce ERK phosphorylation. SIGNIFICANCE: Through this study, we define a new anti-inflammatory effect of intravenous anesthetics. Of the four intravenous anesthetics tested, propofol was the most potent inhibitor of NET formation. Moreover, propofol resulted in a decrease in PMA-induced NET formation by two independent mechanisms: inhibition of HOCl and p-ERK.

Misuse of inhalers among COPD patients in a community hospital in Taiwan.

PURPOSE: Respiratory inhalers, which directly deliver medication to the airway, are important for controlling symptoms and preventing exacerbations of chronic obstructive pulmonary disease (COPD). The inhaler misuse rate of patients with COPD in Taiwan is unclear. In this study, the inhaler techniques and patient characteristics associated with incorrect inhaler techniques among patients with COPD were evaluated. PATIENTS AND METHODS: This cross-sectional study enrolled 298 patients with COPD (mean age 72.10 years) who used at least one inhaler device. The following five types of inhalers were included: metered-dose inhaler (MDI) with spacer, Diskus®, Turbuhaler®, Respimat®, and Breezhaler®. The inhaler technique was evaluated step by step. Misuse of an individual inhaler was defined as an error in at least one step. The sociodemographic characteristics, vision, hearing ability, type and number of inhalers, and inhaler-related knowledge of these patients were recorded. RESULTS: The misuse rates of the five types of inhalers ranged from 65.00% to 87.89%. The Respimat inhaler was the most likely to be assembled incorrectly. The steps that were most commonly performed incorrectly were "breathing out fully" and "holding breath". In the logistic regression analysis, poor hearing was related to misuse of the MDI with spacer (adjusted odds ratio [aOR] 9.85; 95% CI 1.40-69.30); the number of acute exacerbations was related to misuse of Breezhaler (aOR 4.07; 95% CI 1.50-11.08). Incorrect inhaler-related knowledge was significantly associated with misuse in handling the MDI with spacer (aOR 9.58; 95% CI 2.14-42.80), Respimat (aOR 5.14; 95% CI 2.07-12.76), and Breezhaler (aOR 6.98; 95% CI 1.95-25.08). CONCLUSION: The misuse rates were high for all five types of inhaler. Poor hearing and the number of acute exacerbations were device-specific factors related to the misuse of inhalers. Inhaler-related knowledge was significantly associated with misuse, emphasizing the importance of inhaler education.

Propofol specifically suppresses IL-1ß secretion but increases bacterial survival in Staphylococcus aureus-infected RAW264.7 cells.

Anesthetics have immunomodulatory effects, but the use of different assay systems has contributed to inconsistent results in the literature. IL-1ß and reactive oxygen species (ROS) secreted by phagocytes are important factors that protect against Staphylococcus aureus infection. In this study, the effects of four intravenous anesthetics (propofol, thiamylal sodium, midazolam, and ketamine) on IL-1ß secretion, ROS, and bacterial survival in S. aureus-infected RAW264.7 cells were evaluated. S. aureus-infected RAW264.7 cells with or without intravenous anesthetic treatment were established as the experimental model. Cell supernatants were subjected to ELISAs to measure secreted IL-1ß. Cell pellets were subjected to qPCR and western blot analyses to analyze IL-1ß mRNA and protein levels. Luminol chemiluminescence assays were used to detect ROS, and bacterial survival was determined by counting the colony forming units at the beginning and end of the infection. Compared with the levels after treatment with the other intravenous anesthetics, secreted IL-1ß levels were lowest in the supernatant of S. aureus-infected RAW264.7 cell cultures after propofol treatment, but propofol did not decrease IL-1ß mRNA or protein expression. However, thiamylal sodium and midazolam decreased IL-1ß mRNA and protein expression in a dose-dependent manner. Additionally, propofol substantially decreased S. aureus-stimulated ROS and phagocytosis. Bacterial survival was strongly increased by propofol treatment. Of the four intravenous anesthetics, propofol was the most potent inhibitor of IL-1ß secretion and ROS level in S. aureus-infected RAW264.7 cells; moreover, propofol resulted in an increase in bacterial survival by inhibiting ROS and phagocytosis.

Correction: Age-Dependent Sex Difference of the Incidence and Mortality of Status Epilepticus: A Twelve Year Nationwide Population-Based Cohort Study in Taiwan.

[This corrects the article DOI: 10.1371/journal.pone.0122350.].

Comparison of age-specific hospitalization during pandemic and seasonal influenza periods from 2009 to 2012 in Taiwan: a nationwide population-based study.

BACKGROUND: Determining the age-specific hospitalization burden associated with seasonal influenza and the (H1N1) 2009 pandemic is important for the development of effective vaccine strategies and clinical management. The aim of this study was to investigate age-specific differences in hospitalization rates during the pandemic and seasonal periods. METHODS: Using the Taiwan National Health Insurance Research Database (NHIRD), we identified hospitalized patients with a principle discharge diagnosis of influenza-related infection (ICD-9-CM 487) between 2009 and 2012. RESULTS: Based on the time distribution of influenza-related hospitalizations and previously reported epidemic periods, the first and second waves of the (H1N1) 2009 pandemic (p1 is known as 2009.07-2010.01, and p2 is known as 2010.12-2011.03) and three seasonal periods (s1 is known as 2010.03-2010.11, s2 is known as 2011.10-2012.03, and s3 is known as 2012.04-2012.10) were found. During these five periods, children younger than 7 years of age consistently had the highest hospitalization rate of the studied age groups. In individuals younger than 50 years of age, the seasonal periods were associated with a significantly lower risk of hospitalization than that of p1 (Relative risk (RR) range = 0.18-0.85); however, they had a significantly higher hospitalization risk for adults over 50 years of age (RR = 1.51-3.22). Individuals over 50 years of age also had a higher intensive care unit admission rate and case fatality ratio than individuals under than 50 years of age during the seasonal periods and especially during the pandemic periods. CONCLUSIONS: In both pandemic and seasonal periods, the highest hospitalization rate was observed for children younger than 7 years of age. Adults over 50 years of age had a higher hospitalization risk during the seasonal periods and a higher clinical severity during the pandemic periods. Those results emphasize that the importance of influenza-related prevention strategies in the younger and older age groups, either seasonal or pandemic periods.

Incidence and survival of retinoblastoma in Taiwan: a nationwide population-based study 1998-2011.

OBJECTIVE: To study the epidemiology of retinoblastoma in Taiwan from 1998 to 2011. DESIGN: This was a retrospective population-based cohort study using the Taiwan National Health Insurance Research Database. RESULTS: The present study included 154 patients (92 males, 62 females) with retinoblastoma and the documented overall retinoblastoma incidence was 1 in 17 373 live births without a notable trend over the study period. The incidence per million live births examined by gender was 65.8 for males and 48.5 for females. The age-specific sex ratio increased from 1.4 at age younger than 1 year to 3.0 above age 4 years. Enucleation was performed in 109 (70.8%) children with retinoblastoma, and it was more prevalent in males than in females (77.2% vs 61.3%, p=0.0335). Multivariate Cox regression analyses with adjustment for diagnostic age, sex, and birth year elucidated that enucleation was a significant factor associated with survival (OR 0.27, 95% CI 0.10 to 0.61). CONCLUSIONS: The incidence of retinoblastoma in Taiwan exhibited no marked trend over time. There were more cases of males than females and the male-to-female rate ratio increased with age. Survival outcome was significantly associated with the intervention of enucleation.

Epidemiology of Hirschsprung's Disease in Taiwanese Children: A 13-year Nationwide Population-based Study.

BACKGROUND: Hirschsprung's disease (HD) is an important colon disease in children. The aim of this study is to describe the epidemiological features of HD in Taiwanese children. METHODS: We conducted a study from the Taiwan National Health Insurance Research Database and analyzed cases who received surgical intervention between 1998 and 2010 due to HD (International Classification of Diseases, 9(th) Revision, Clinical Modification 751.3) or megacolon (International Classification of Diseases, 9(th) Revision, Clinical Modification 564.7). The incidence, sex ratio, age at the surgical intervention, associated complication, and medical expenditures were analyzed. RESULTS: There were a total of 629 HD cases, including 458 boys and 171 girls, with an overall incidence of 2.2 per 10,000 live births. The male-to-female incidence ratio was 2.38. There was no secular trend of incidence across the years. Seventy-two percent of cases received surgical treatment before the age of 1 year. The younger cases had higher operation-related medical expenditures. Those patients with preoperative enterocolitis (EC) had a higher possibility of postoperative EC than those patients without preoperative EC (34.6% vs. 24.3%, p = 0.013). There were 169 (26.9%) HD cases with additional anomalies, the most common being gastrointestinal and circulatory system anomalies. Of these, 12 (1.9%) cases were Down syndrome. CONCLUSION: The incidence of HD in Taiwanese children, a majority Chinese population, was one per 4545 live births with a male predominance. Preoperative EC was a significant factor that was associated with postoperative EC. The percentage associated with Down syndrome was relatively low, probably due to a prenatal screening program.

Age-dependent sex difference of the incidence and mortality of status epilepticus: a twelve year nationwide population-based cohort study in Taiwan.

Status epilepticus (SE) is a serious neurologic emergency associated with a significant mortality. The objective of this study is to investigate its epidemiology in terms of age- and sex-specific incidences and mortality. By using the Taiwan National Health Insurance Research Database during 2000 to 2011, we identified hospitalized patients with a discharged diagnosis of SE and calculated the incidence and in-hospital mortality of SE with respect to age and sex. The overall incidence of SE was 4.61 per 100,000 person-years, which displayed a "J-shaped" distribution by age with a little higher under the age of 5 and highest over 60 years. The male-to-female rate ratio was 1.57 and it demonstrated a "mountain-shape" across ages with the peak at 45 to 49 years old. The in-hospital mortality was significantly lower in males (7.38%) than in females (11.12%) with an odds ratio of 0.64 (95% CI 0.56-0.72). Notably, the in-hospital mortality for females increased rapidly after the age of 40 to 45 years. The multivariate analysis found males had a significantly lower risk of mortality than females after, but not before, 45 years of age with an odds ratio of 0.56 (95% CI 0.49-0.65). Sex and age are crucial factors associated with the incidence and in-hospital mortality of SE. The females over 45 years of age have a higher risk of occurrence and mortality from SE. The underlying mechanism deserves further study.

Genome Sequence and Annotation of Helicobacter pylori Strain Hp238, Isolated from a Taiwanese Patient with Mucosa-Associated Lymphoid Tissue Lymphoma.

We present the complete genome sequence of Helicobacter pylori strain Hp238, isolated from a Taiwanese patient with gastric mucosa-associated lymphoid tissue lymphoma. Importantly, H. pylori strain Hp238 can multiply in THP-1 cells after internalization through the induction of autophagosome formation. These genome data will help to identify genes associated with H. pylori intracellular multiplication and pathogenesis.

Higher glucose level can enhance the H. pylori adhesion and virulence related with type IV secretion system in AGS cells.

BACKGROUND: Hyperglycemia increases the risk of gastric cancer in H. pylori-infected patients. High glucose could increase endothelial permeability and cancer-associated signaling. These suggest high glucose may affect H. pylori or its infected status.We used two strains to investigate whether H. pylori growth, viability, adhesion and CagA-phosphorylation level in the infected-AGS cells were influenced by glucose concentration (100, 150, and 200 mg/dL). RESULTS: The growth curves of both strains in 200 mg/dL of glucose were maintained at the highest optimal density after 48 h and the best viability of both strains were retained in the same glucose condition at 72 h. Furthermore, adhesion enhancement of H. pylori was significantly higher in 200 mg/dL of glucose as compared to that in 100 and 150 mg/dL (p < 0.05). CagA protein also increased in higher glucose condition. The cell-associated CagA and phosphorylated-CagA was significantly increased in 150 and 200 mg/dL of glucose concentrations as compared to that of 100 mg/dL (p < 0.05), which were found to be dose-dependent. CONCLUSION: Higher glucose could maintain H. pylori growth and viability after 48 h. H. pylori adhesion and CagA increased to further facilitate the enhancement of cell-associated CagA and phosphorylated CagA in higher glucose conditions.

Heteroresistance of Helicobacter pylori from the same patient prior to antibiotic treatment.

Antibiotic resistance among Helicobacter pylori strains has been increasing worldwide and has affected the efficacy of current treatments. The aim of this study was to evaluate whether treatment failure was due to the presence of antibiotic-susceptible and -resistant H. pylori simultaneously within the same host before eradication. In order to discover H. pylori with antibiotic heteroresistance in the same patient, we examined the antibiotic susceptibility of H. pylori isolated from 412 patients without H. pylori eradication. The E-test was used to determine the minimal inhibitory concentration of these strains. The results showed 19 (4.6%) of patients harbored antibiotic heteroresistant H. pylori, resistant to levofloxacin (5/19), clarithromycin (1/19) and metronidazole (16/19). Among them, three patients' isolates showed heteroresistance to two antibiotics. The genetic diversity of each isolate was evaluated by random amplified polymorphic DNA PCR and the results showed that only 1 patient' isolate (5.3%) had a different pattern while the others showed identical or similar fingerprinting patterns. Mutations in the genes responsible for antibiotic resistance were investigated by direct sequencing and compared between strains within each pair. All 5 levofloxacin-resistant isolates had mutations in GyrA at the QRDR region (N87 or D91). Strain 1571R with clarithromycin resistance had a A2042G substitution in its 23S rRNA. There were 15 metronidazole-resistant strains (100%) with isogenic variation of RdxA, and 6 strains (40%) contained FrxA variation (excluded pair 1159). These results suggest that the treatment failure of heteroresistant H. pylori mostly develops from high genomic variation of pre-existing strains through long term evolution rather than mixed infection with different strains.

Higher motility enhances bacterial density and inflammatory response in dyspeptic patients infected with Helicobacter pylori.

BACKGROUND: Motility mediated by the flagella of Helicobacter pylori is important for the cells to move toward the gastric mucus in niches adjacent to the epithelium; then, H. pylori uses the adhesin SabA to interact with sialyl-Le(x) on inflammatory host cells for persistent infection. Here, we reveal the clinical association of bacterial motility, SabA expression, and pathological outcomes. METHODS: Ninety-six clinical isolates were screened for bacterial motility, and the expression of SabA of each isolate was confirmed by Western blotting. H. pylori-infected patients were assessed for their bacterial density, sialyl-Le(x) expression, inflammatory scores, and clinical diseases. RESULTS: The mean diameter in the motility assay was 17 mm, and eight (8.3%) of the strains had impaired motility, with a diameter <5 mm. H. pylori density in cardia, the acute inflammatory score in the body locus, and the prevalence rate of gastric atrophy were increased in patients infected with higher-motility strains (p = .023, <.001, or <.001, respectively). The total inflammatory scores (both acute and chronic) and bacterial density dramatically increased in patients expressing the sialyl-Le(x) antigen and infected with higher-motility, SabA-positive H. pylori (p = .016, .01, or .005, respectively). CONCLUSION: These results suggest that the higher motility of H. pylori enhances pathological outcomes, and the SabA-sialyl-Le(x) interaction has a synergistic effect on virulence of the higher-motility strains.

H. pylori clinical isolates have diverse babAB genotype distributions over different topographic sites of stomach with correlation to clinical disease outcomes.

BACKGROUND: Intragenomic recombination between babA and babB mediates antigenic variations and may help H. pylori colonization. This study determined whether variable genotypes of babA and babB correlate to different clinical disease outcomes, and can distribute over the different gastric niches. RESULTS: This study enrolled 92 clinical strains (45 from peptic ulcer, 27 from gastritis, and 20 from gastric cancer) to detect whether the babA and babB are at locus A or B by PCR reactions using the primers designed from the upstream and variable region of the babA and babB genes. Four genotypes of babA and babB (A B, AB B, A AB, AB AB) were found. The distribution of the 4 genotypes in 92 clinical strains was significantly different among patients with different gastric diseases (p < 0.05). The isolates from gastric cancer patients had a higher rate of AB AB genotype than those from non-cancer patients (40.0% vs. 9.7%, p < 0.05). The AB AB genotype was associated with a higher intensity of intestinal metaplasia (p < 0.05), but did not correlate with a higher inflammation and colonization density in gastric histology (p > 0.05). Besides, the study enrolled 19 patients to verify whether variable genotypes of babAB existed in the different gastric niches. Among the patients infected with more than one babAB genotypes over antrum and corpus, there were higher rate of genotypes as A B or AB AB in isolates from antrum than in those from corpus (75.0 % vs. 16.7%, p < 0.05). CONCLUSIONS: The H. pylori isolate with the AB AB genotype correlates with an increased gastric cancer risk, and colonize in an antrum predominant manner.

Length of thymidine homopolymeric repeats modulates promoter activity of sabA in Helicobacter pylori.

BACKGROUND: Helicobacter pylori uses SabA to interact with sialyl-Lewis x on the gastric mucosal surface to establish persistent colonization. The number of CT repeats in sabA is variable and thus influences SabA translation, but the expression of SabA determined by Western blotting does not fully match with a CT sequence-based prediction. Furthermore, a homopolymeric thymidine (polyT) tract located upstream of sabA has been observed, but its role in regulating sabA expression is still unknown. METHODS: The transcriptional start site (TSS) of sabA in strains J99 and Hp258 was determined by 5' RACE. One hundred and fifteen clinical isolates were sequenced to analyze the distribution of the polyT tract length and promoter sequence. Finally, RT-PCR and an E. coli-lux reporter system were used to determine the sabA promoter activity with different lengths of the polyT tract. RESULTS: The TSS of sabA was located at 66 or 64 bp upstream of the translational start codon in J99 and Hp258, respectively. The polyT tract close to the -35 element varied from T10 to T28 in 115 clinical isolates, and 70% of the isolates contained a stretch of 14-19 Ts. The sabA gene displayed slipped strand mispairing (SSM) of the polyT tract, generating varying genotypes in J99 (16-18 Ts) and Hp258 (14-15 Ts). Furthermore, J99 with lengths of T16 and T30, had higher sabA promoter activity than the common length of T18. CONCLUSION: Our findings indicate that the sabA promoter region modulates its transcriptional activity through a variable polyT tract, and SSM generates mixed genotypes in the population.