BanXiaXieXin decoction treating gastritis mice with drug-resistant Helicobacter pylori and its mechanism.

BACKGROUND: Helicobacter pylori (H. pylori) is the main pathogen that causes a variety of upper digestive diseases. The drug resistance rate of H. pylori is increasingly higher, and the eradication rate is increasingly lower. The antimicrobial resistance of H. pylori is an urgent global problem. It has been confirmed that Banxia Xiexin decoction (BXXXT) demonstrates the effects of treating gastrointestinal diseases, inhibiting H. pylori and protecting gastric mucosa. The purpose of the present study is to further explore the therapeutic effects of BXXXT on drug-resistant H. pylori. AIM: To confirm that BXXXT demonstrates therapeutical effects in vivo and in vitro on gastritis mice with drug-resistant H. pylori and explain its mechanism to provide an experimental basis for promoting the application of BXXXT. METHODS: The aqueous extract of BXXXT was gained by water decocting method. The inhibitory effect of the aqueous extract on H. pylori was detected by dilution in vitro; drug-resistant H. pylori cells were used to build an acute gastritis model in vivo. Thereafter, the model mice were treated with the aqueous extract of BXXXT. The amount of H. pylori colonization, the repair of gastric mucosal damage, changes of inflammatory factors, apoptosis, etc., were assessed. In terms of mechanism exploration, the main medicinal compositions of BXXXT aqueous extract and the synergistic bacteriostatic effects they had demonstrated were analyzed using mass spectrometry; the immune function of peripheral blood cells such as CD3+ T and CD4+ T of mice with gastritis before and after treatment with BXXXT aqueous extract was detected using a flow cytometry; the H. pylori transcriptome and proteome after treatment with BXXXT aqueous extract were detected. Differently expressed genes were screened and verification was performed thereon with knockout expression. RESULTS: The minimum inhibitory concentration of BXXXT aqueous extract against H. pylori was 256-512 µg/mL. A dose of 28 mg/kg BXXXT aqueous extract treatment produced better therapeutical effects than the standard triple therapy did; the BXXXT aqueous extract have at least 11 ingredients inhibiting H. pylori, including berberine, quercetin, baicalin, luteolin, gallic acid, rosmarinic acid, aloe emodin, etc., of which berberine, aloe emodin, luteolin and gallic acid have a synergistic effect; BXXXT aqueous extract was found to stimulate the expressions of CD3+ T and CD4+ T and increase the number of CD4+ T/CD8+ T in gastritis mice; the detection of transcriptome and proteome, quantitative polymerase chain reaction, Western blotting and knockout verification revealed that the main targets of BXXXT aqueous extract are CFAs related to urea enzymes, and CagA, VacA, etc. CONCLUSION: BXXXT aqueous extract could demonstrate good therapeutic effects on drug-resistance H. pylori in vitro and in vivo and its mechanism comes down to the synergistic or additional antibacterial effects of berberine, emodin and luteolin, the main components of the extract; the extract could activate the immune function and enhance bactericidal effects; BXXXT aqueous extract, with main targets of BXXXT aqueous extract related to urease, virulence factors, etc., could reduce the urease and virulence of H. pylori, weaken its colonization, and reduce its inflammatory damage to the gastric mucosa.

Characterization of carbapenem-resistant Acinetobacter baumannii ST540 and Klebsiella pneumoniae ST2237 isolates in a pneumonia case from China.

AIMS: This study aimed to characterize the chromosome and plasmid sequences, and determine the transferability of plasmids in carbapenem-resistance Acinetobacter baumannii DD520 and Klebsiella pneumoniae DD521 isolates from the same patient who was co-infected in a hospital in China. METHODS AND RESULTS: Both isolates DD520 and DD521 exhibited multidrug resistance phenotype, especially the former isolate which was resistant to nine classes of antimicrobials including carbapenems, quinolones, penicillins, cephalosporins, tetracyclines, phenicols, fosfomycins, sulfanilamides and aminoglycosides. Carbapenem resistance genes of blaOXA-23 and blaOXA-66 were identified on the chromosome of A. baumannii DD520, and blaKPC-2 was found in the plasmid pDD521.2 from K. pneumoniae DD521. Phylogenetic analysis revealed that A. baumannii DD520 belonged to the ST540 clone, and K. pneumoniae DD521 belonged to the ST2237 clone. Plasmid analysis suggested that blaKPC-2 was embedded into plasmid pDD521.2, which might be resulted from IS26- and Tn1721-mediated transposition. Plasmid pDD521.2 carrying blaKPC-2 successfully transferred from K. pneumoniae DD521 into Escherichia coli C600, and carbapenems resistance also transferred in the conjugation. CONCLUSIONS: To our knowledge, it was the first report of A. baumannii ST540 and K. pneumoniae ST2237 in the same patient in China. Both these two isolates exhibited resistance to carbapenem, which was likely to have resulted from carbapenem-resistance genes blaOXA-23 -blaOXA-66 on the chromosome of A. baumannii ST540, and blaKPC-2 in the plasmid of K. pneumoniae ST2237. SIGNIFICANCE AND IMPACT OF THE STUDY: Our study highlighted that effective measures were urgent to prevent and control the co-infection caused by two or more carbapenem-resistance pathogens in the same patient.

Replication and Pathology of Duck Influenza Virus Subtype H9N2 in Chukar.

To investigate the susceptibility of Chukars to duck avian influenza virus H9N2 and explore their role in interspecies transmission of influenza viruses. Chukars were inoculated with duck avian influenza viruses H9N2. The present study demonstrated that inflammatory lesions and virus antigen were present in the trachea, bronchus, and parabronchus, and the viruses could be isolated from throat swabs and lung tissue homogenate supernatants. At 14 d post virus inoculation, anti-H9 influenza virus antibody in the serum was detected. The results indicated that Chukars are susceptible to duck avian influenza virus and serve as an intermediate host, thereby facilitating viral gene evolution and supporting the need for continued surveillance of epidemiology and evolution of the influenza virus in Chukars.

The hemagglutinin-neuramidinase protein of Newcastle disease virus upregulates expression of the TRAIL gene in murine natural killer cells through the activation of Syk and NF-κB.

Newcastle disease virus (NDV) is responsible for tumoricidal activity in vitro and in vivo. However, the mechanisms that lead to this activity are unclear. Natural killer cells are able to induce apoptosis of tumor cells through multiple pathways, including the tumor necrosis factor-related apoptosis-inducing ligand-death receptor pathway. We previously showed that exposure of NK and T cells to NDV resulted in enhanced tumoricidal activity that was mediated by upregulated expression of the TRAIL gene, via an interferon gamma -dependent pathway. Other pathways involved in the upregulated expression of TRAIL are yet to be identified. In the current study, we used mice in which the IFN-γ receptor one gene was inactivated functionally. We identified an IFN-γ-independent TRAIL pathway in the NDV-stimulated NK cells. Hemagglutinin-neuramidinase induced expression of the TRAIL gene in IFN-R1-/- NK cells by binding to the NKp46 receptor. This upregulation was inhibited by pretreatment of NDV with a neutralizing monoclonal antibody against HN, or desialylation of NK cells. Phosphorylation of spleen tryosine kinases and IκBα was increased in HN-induced IFN-R1-/- NK cells. Treatment with the HN neutralizing monoclonal antibody, pharmacological disialylation, or a Syk inhibitor decreased Syk and IκBα phosphorylation levels. We concluded that killer activation receptors pathway is involved in the IFN-γ-independent TRAIL expression of NDV-stimulated NK cells, and these are activated by Syk and NF-κB.

TRAIL is involved in the tumoricidal activity of mouse natural killer cells stimulated by Newcastle disease virus in vitro.

Newcastle disease virus (NDV) is a potential antitumor agent, and its antitumor effect has been evaluated in preclinical tests. However, the mechanisms of NDV-based antitumor therapy are still not completely clear. In the present study we found that NDV-stimulation enhanced the killing ability of mouse spleen natural killer (NK) cells towards mouse hepatoma cell lines, and tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) plays an important role in this tumoricidal activity. NDV stimulation induced up-regulation of TRAIL both at the mRNA and protein levels in NK cells. Blocking TRAIL by antibody (Ab) almost completely eliminated the killing effect of NK cells on hepatoma cell lines. Furthermore, neutralizing interferon (IFN)-γ by Ab could inhibit TRAIL expression and tumoricidal activity of NDV-stimulated NK cells. These results indicated a substantial role of TRAIL as an effector molecule in NDV-induced NK cells mediated tumoricidal activity. The NDV stimulation triggered TRAIL expression in mouse spleen NK cells could be mediated by IFN-γ induction.

[Avian influenza virus subtype H9N2 replicates in human lung tissues].

Avian influenza virus subtype H9N2 has been circulating in multiple terrestrial birds and repeatedly infecting mammals, including swines and humans to pose a significant threat to public health. The cross-species infection of human, replication activity and tissue tropism of avian influenza virus H9N2 was evaluated in this study. The results showed that surgically removed human lung tissue samples were infected ex vivo by avian influenza virus subtype H9N2 (Ck/GX/1875/04, Ck/GX/187/05) and seasonal human influenza virus H3N2 (A/ST/602/05). Examination of nucleoprotein expression replication in the infected human lung tissue samples showed that the replication of avian influenza virus H9N2 and seasonal human influenza virus H3N2 were mainly prevalent in alveolar epithelial cells, respiratory bronchiole epithelial cells and bronchial epithelial cells. Double-immunostaining for viral antigens and cellular markers indicated that avian influenza virus subtype H9N2 replicated in type 2 alveolar epithelial cells. These findings suggest that the H9N2 virus may be better adapted to the human host and replicates efficiently in human lung epithelial cells. Moreover, H9N2 avian influenza virus repeatedly infecting human, may favor gene evolution and the potential emergence of pandemic influenza virus.

Catalytic activity of Matrix metalloproteinase-19 is essential for tumor suppressor and anti-angiogenic activities in nasopharyngeal carcinoma.

The association of Matrix metalloproteinase-19 (MMP19) in the development of nasopharyngeal carcinoma (NPC) was identified from differential gene profiling, which showed MMP19 was one of the candidate genes down-regulated in the NPC cell lines. In this study, quantitative RT-PCR and Western blot analysis showed MMP19 was down-regulated in all seven NPC cell lines. By tissue microarray immunohistochemical staining, MMP19 appears down-regulated in 69.7% of primary NPC specimens. Allelic deletion and promoter hypermethylation contribute to MMP19 down-regulation. We also clearly demonstrate that the catalytic activity of MMP19 plays an important role in antitumor and antiangiogenesis activities in comparative studies of the wild-type and the catalytically inactive mutant MMP19. In the in vivo tumorigenicity assay, only the wild-type (WT), but not mutant, MMP19 transfectants suppress tumor formation in nude mice. In the in vitro colony formation assay, WT MMP19 dramatically reduces colony-forming ability of NPC cell lines, when compared to the inactive mutant. In the tube formation assay of human umbilical vein endothelial cells and human microvascular endothelial cells (HMEC-1), secreted WT MMP19, but not mutant MMP19, induces reduction of tube-forming ability in endothelial cells with decreased vascular endothelial growth factor (VEGF) in conditioned media detected by enzyme-linked immunosorbent assay (ELISA). The anti-angiogenic activity of WT MMP19 is correlated with suppression of tumor formation. These results now clearly show that catalytic activity of MMP19 is essential for its tumor suppressive and anti-angiogenic functions in NPC.