Search

Gibberellic acid (GA3) is a tetracyclic diterpene compound which displays interesting bioactivities. Recently, its potential use for preparing antitumor drug leads has been highlighted, and various modification methods of GA3 have been reported. Aiming at investigating GA3 derivatives with potential antitumor activities, ring distortion of GA3 under different conditions was carried out, and this was followed with amidation or substitution, yielding four series of derivatives. The chemical structure of these compounds were analyzed by 1H-NMR, 13C-NMR, HRMS, FTIR and polarimetry, and SXRD was employed to further confirm the spatial configurations of derivatives 3c and 7d. The antitumor activities of three series of derivatives were evaluated by using MTT assay and ELISA. Results shows that, among amide derivatives, compounds with a saturated linear amide showed better activity than those with an aromatic amide. Among ester derivatives, compounds with a meta-substituted benzyl group showed better activities than those with a para-substituted benzyl group. The antitumor activity of ester derivatives might possibly be linked with the inhibition of FGFR1 activation and KDR activation. Overall, this study discussed how the antitumor activity of GA3 was formed, thereby assisting the future design of more effective active GA3 derivatives.

Signal molecules are stimulators of multiple quroum-sensing virulence and biofilm formation. Small molecule analogues have been suspected as a potent inhibitor in therapeutic strategy. Herein, we synthesized a series of small molecule compounds from the 2, 8-bit derivatives of quinoline by Suzuki coupling reaction. We found that these compounds have the biofilm inhibitory effect in normal condition instead of phosphate limitation state. Furthermore, lacZ reporter strain assay and rhamnolipids as well as pyocyanin experiments showed that these compounds did not affect las and pqs system but reduced the expression of rhl. All these results suggest that quinoline derivatives can be treated as potent inhibitors against biofilm and reduce virulence through the rhl system. This research will be useful in designing new quorum sensing inhibitors to attenuate the infection of bacteria.

Aim: To investigate the biological fate of cuprous oxide nanoparticles (Cu2O-NPs) and to evaluate their potential in uveal melanoma therapy. Materials & methods: The protein corona, cellular uptake mechanism and localization of Cu2O-NPs were investigated. Furthermore, the effect of Cu2O-NPs on uveal melanoma cell proliferation, migration and invasion, and possible mechanisms were studied in detail. Results: Cu2O-NPs are able to adsorb serum proteins in cell culture medium, which are then internalized by uveal melanoma cells mainly through lipid raft-mediated endocytosis. Furthermore, Cu2O-NPs selectively inhibit cancer cell growth and impair the ability of uveal melanoma cell migration, invasion and the cytoskeleton assembly. The mechanism may be that Cu2O-NPs located in and damage mitochondria, autophagolysosomes and lysosomes, leading to elevated reactive oxygen species level and over-stimulated apoptosis and autophagy. Conclusion: The data provide detailed information of Cu2O-NPs for further application and indicate that Cu2O-NPs could be a potential agent for uveal melanoma therapy.

Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus that causes the most prevalent viral encephalitis in Asia. Since JEV is a neurotropic virus, it is important to identify key molecules that mediate JEV infection in neuronal cells and to investigate their underlying mechanisms. In this study, the critical role of Nedd4, an E3 ubiquitin ligase that is highly expressed in the central nervous system, was examined in JEV propagation. In SK-N-SH neuroblastoma cells, Nedd4 was up-regulated in response to JEV infection. Moreover, down-regulation of Nedd4 resulted in a significant decrease in JEV replication without alterations in virus attachment and internalization or in JEV pseudotyped virus infection, suggesting that Nedd4 participates in the replication but not in the entry stage of JEV infection. Further functional analysis showed that Nedd4 attenuated JEV-induced autophagy, which negatively regulates virus replication during infection. These results suggest that Nedd4 facilitates the replication of JEV by suppressing virus-induced autophagy. Taken together, our results indicate that Nedd4 plays a crucial role in JEV infection of neuronal cells, which provides a potential target for the development of novel treatment to combat JEV infection.

Streptococcus suis serotype 2 ( S. suis 2) is an important zoonotic pathogen that causes considerable economic losses to the pig industry and significantly threatens public health worldwide. The highly pathogenic S. suis 2, which contains the 89K pathogenicity island (PAI), has caused large-scale outbreaks of infections in humans, resulting in high mortality rates. In this study, we established two loop-mediated isothermal amplification (LAMP)-based assays that can rapidly detect S. suis 2 and the 89K PAI and can be performed simultaneously under the same conditions. Further, based on the findings of these two LAMP assays and using the same set of serially diluted DNA samples, we compared the sensitivities of different LAMP product detection methods, including SYBR green detection, gel electrophoresis, turbidimetry, calcein assays, and hydroxynaphthol blue detection. The results suggest that target genes can be amplified and detected within 48 min under 63°C isothermal conditions. The sensitivity of tests for S. suis 2 detection varies between detection methods and reaction systems, indicating that for each LAMP reaction system, multiple detection methods should be performed to select the optimal one. The sensitivities of the optimized methods (7.16 copies/reaction) in the present study were identical to those of the real-time PCR assay, and the test results for reference strains and clinical samples showed that these LAMP systems have high specificities. Thus, since the LAMP systems established in this study are simple, fast, and sensitive, they may have good clinical potential for detecting the highly pathogenic S. suis 2.

Despite recent progress in the development of hepatitis C virus (HCV) inhibitors, cost-effective antiviral drugs, especially among the patients receiving liver transplantations, are still awaited. Schisandra is a traditional medicinal herb used to treat a range of liver disorders including hepatitis for thousands of years in China. To isolate the bioactive compounds of schisandra for the treatment of HCV infection, we screened a schisandra-extracts library and identified a tetracyclic triterpenoid, schizandronic acid (SZA), as a novel HCV entry inhibitor. Our findings suggested that SZA potently inhibited pan-HCV genotype entry into hepatoma cells and primary human hepatocytes without interfering virus binding on cell surface or internalization. However, virion-cell fusion process was impaired in the presence of SZA, along with the increased host membrane fluidity. We also found that SZA inhibited the spread of HCV to the neighboring cells, and combinations of SZA with interferon or telaprevir resulted in additive synergistic effect against HCV. Additionally, SZA diminished the establishment of HCV infection in vivo. The SZA target is different from conventional direct-acting antiviral agents, therefore, SZA is a potential therapeutic compound for the development of effective HCV entry inhibitors, especially for patients who need to prevent HCV reinfection during the course of liver transplantations.

Although much progress has been made in antiviral agents against hepatitis C virus (HCV) in recent years, novel HCV inhibitors with improved efficacy, optimized treatment duration and more affordable prices are still urgently needed. Here, we report the identification of a natural plant-derived lignan, trachelogenin (TGN), as a potent entry inhibitor of HCV without genotype specificity, and with low cytotoxicity. TGN was extracted and purified from Caulis trachelospermi, a traditional Chinese herb with anti-inflammatory and analgesic effects. A crucial function of TGN was the inhibition of HCV entry during a post-binding step without affecting virus replication, translation, assembly and release. TGN blocked virus infection by interfering with the normal interactions between HCV glycoprotein E2 and the host entry factor CD81, which are key processes for valid virus entry. In addition, TGN diminished HCV cell-to-cell spread and exhibited additional synergistic effects when combined with IFN or telaprevir. In conclusion, this study highlights the effect of a novel HCV entry inhibitor, TGN, which has a target that differs from those of the current antiviral agents. Therefore, TGN is a potential candidate for future cocktail therapies to treat HCV-infected patients.

Objectives: Hepatitis C virus (HCV) F protein is a newly identified protein encoded by an alternative open reading frame that +1 overlaps core-encoding gene. It has been found that regulation of c-myc and p53 genes by HCV core protein is involved in liver cancer genesis. We wondered whether HCV F protein exerts similar or adverse regulatory effects on the transcription of c-myc and p53 genes. Methods: HCV F gene-containing, plasmid pcDNA3.1-F and HCV core gene-containing pcDNA3.1-C were constructed and transiently transfected into HepG2 cells. Real-time quantitative PCR or Western blotting was used to determine the changes at transcription or translation levels of c-myc and p53 genes. Results: The transcription level of c-myc was much higher in pcDNA3.1-F transfected cells than those without plasmid transfected. Whereas the level of p53 transcription in pcDNA3.1-F transfected cells was lower than those in the parental cells. Moreover, levels of c-myc expression were up-regulated and those of p53 expression were down-regulated by HCV F protein. Conclusions: HCV F protein is of regulatory properties in cellular oncogene c-myc and anti-oncogene p53, which may be implicated in the formation of hepatocellular carcinoma.

// Cui-Ling Ding 1,* , Gang Xu 1,* , Hai-Lin Tang 1 , Shi-Ying Zhu 1 , Lan-Juan Zhao 1 , Hao Ren 1 , Ping Zhao 1 , Zhong-Tian Qi 1 and Wen Wang 1 1 Department of Microbiology, Shanghai Key Laboratory of Medical Biodefense, Second Military Medical University, Shanghai, China * These authors have contributed equally to this work Correspondence to: Zhong-Tian Qi, email: // Wen Wang, email: // Keywords : RAI16, Fam160B2, AKAP, PKA-RIIα, 14-3-3θ Received : January 19, 2015 Accepted : March 05, 2015 Published : March 30, 2015 Abstract Our previous study reported that retinoic acid induced 16 (RAI16) could enhance tumorigenesis in hepatocellular carcinoma (HCC). However, the cellular functions of RAI16 are still unclear. In this study, by immunoprecipitation and tandem (MS/MS) mass spectrometry analysis, we identified that RAI16 interacted with the type II regulatory subunit of PKA (PKA-RIIα), acting as a novel protein kinase A anchoring protein (AKAP). In addition, RAI16 also interacted with heat shock protein 70 (HSP70) and 14-3-3θ. Further studies indicated that RAI16 mediated PKA phosphorylation of HSP70 at serine 486, resulting in anti-apoptosis events. RAI16 was also phosphorylated by the anchored PKA at serine 325, which promoted the recruitment of 14-3-3θ, which, in turn, inhibited RAI16 mediated PKA phosphorylation of HSP70. These findings offer mechanism insight into RAI16 mediated anti-apoptosis signaling in HCC.

Hepatitis C virus (HCV) infection correlates with human immune disorders characterized by abnormal activation and proliferation of lymphocytes. Interaction of HCV major envelope protein E2 with susceptible cells occurs at an early stage of the viral infection. HCV tropism for susceptible cells may elicit cellular signaling events implicated in the viral pathogenicity, and E2 protein is known to be responsible for the tropism. We documented previously that HCV E2 protein was capable of activating extracellular signal-regulated kinase (ERK) in human hepatoma Huh-7 cells. Here, ERK and p38 mitogen-activated protein kinase (MAPK) signaling pathways were investigated in human T lymphoma cell line Molt-4 in response to HCV E2 protein. Binding of HCV E2 protein to Molt-4 cells was detectable, and such interaction was a determinant for recognition and delivery of the E2 signal to intracellular pathways. Activation of ERK and p38 MAPK was specifically induced following the HCV E2-cell interaction. CD81 and low-density lipoprotein receptor (LDLR), proposed cellular receptors for HCV, were expressed naturally on Molt-4 cells. CD81 and LDLR were shown to mediate HCV E2-induced activation of ERK and p38 MAPK. In CD81-deficient U937 cells, levels of ERK and p38 MAPK activation and cell proliferation induced by HCV E2 protein were lower than those in Molt-4 cells. Furthermore, cell proliferation and secretion of interferon-γ and interleukin-10 by Molt-4 cells were promoted by HCV E2 protein. Therefore, ERK and p38 MAPK signaling pathways were up-regulated by HCV E2 protein without synergetic stimulation, which was accompanied by alterations of cell behavior.

The objective of this study is to investigate the characteristics of the recombinant variant of human vascular endothelial cell growth inhibitor, VEGI72−251, and compare its biological activities with that of its prototype VEGI24−174. The recombinant plasmid containing the variant VEGI72−251 gene was constructed and expressed in Escherichia coli. The effects of the expressed VEGI72−251 on cell proliferations were checked in the human umbilical vein endothelial cell line and certain tumor cell lines (ECV304 and B16). The inhibition of VEGI72−251 on angiogenesis was detected in the chorioallantoic membrane of chick embryos. In comparison with VEGI24−174, the recombinant human VEGI72−251 seems to have no effect on the proliferation of endothelial cells and the angiogenesis of the chorioallantoic membrane in vitro. An enzyme-linked immunosorbent assay- based method was used for the measurement of interleukin-2 (IL-2) production by peripheral blood monocytes (PBMCs) treated with VEGI72−251. PBMCs were pretreated with VEGI72−251 (1.25−12.50 μg/ml) for 24 h in vitro, and the IL-2 concentration in PBMC medium was increased from 354 pg/ml to 1256 pg/ml. It can be concluded that VEGI72−251 is able to increase the level of human IL-2 production by the activation of T lymphocytes. Differing from VEGI24−174 on anti-angiogenesis, VEGI72−251 may serve as an anti-cancer factor through its activation of T lymphocytes.

The spike (S) protein, a main surface antigen of SARS-coronavirus (SARS-CoV), is one of the most important antigen candidates for vaccine design. In the present study, three fragments of the truncated S protein were expressed in E. coli, and analyzed with pooled sera of convalescence phase of SARS patients. The full length S gene DNA vaccine was constructed and used to immunize BALB/c mice. The mouse serum IgG antibody against SARS-CoV was measured by ELISA with E. coli expressed truncated S protein or SARS-CoV lysate as diagnostic antigen. The results showed that all the three fragments of S protein expressed by E. coli was able to react with sera of SARS patients and the S gene DNA candidate vaccine could induce the production of specific IgG antibody against SARS-CoV efficiently in mice with seroconversion ratio of 75% after 3 times of immunization. These findings lay some foundations for further understanding the immunology of SARS-CoV and developing SARS vaccines.

The human CD81 (hCD81) molecule has been identified as a putative receptor for hepatitis C virus (HCV). In this study, eukaryotic expression vector pCDM8-hCD81 containing hCD81 cDNA and pSV2 neo helper plasmid was used to cotransfect with lipofectamine into murine fibroblast cell line NIH/3T3 to establish an hCD81-expressing cell line. Resistant cell clones were obtained 20 days after the selection with neomycin (600 μg/ml) and then cultured as monoclones. The expression of the transfected hCD81 gene in the cells was verified by RT-PCR and flow cytometry analyses. One of the selected cell clones showed obvious expression of hCD81 and was named NIH/3T3-hCD81. Competitive inhibition tests indicated that the binding of monoclonal anti-hCD81 (JS-81) to NIH/3T3-hCD81 cells was inhibited by recombinant HCV E2 protein, suggesting that the expressed hCD81 molecules on NIH/3T3-hCD81 cells maintain natural conformation of binding to HCV E2. The transfected NIH/3T3-hCD81 cells should be of great potential value in studies on HCV attachment and onset of infection.

To understand the current state of staff for Plasmodium microscopy examinations in Changzhou City in the early stage of eliminating malaria action, so as to provide the evidence for achieving the target of malaria elimination.The staff for Plasmodium microscopy examinations from medical institutions and centers for disease control and prevention at different levels were investigated by questionnaires and tests of the malaria related theory and microscopic operation.Totally 95 people were investigated, and among them, 40.0% had college degree and 45.3% were university educated. There were 18.9% of them working on Plasmodium microscopy examinations for less than 1 year, 40.0% for 2-5 years, 18.9% for 6-10 years and 22.1% for more than 10 years. The numbers of person-time of provincial and municipal level training, district-level training, and unit-level training in the last year were 0.57, 0.59, and 0.14, respectively. Totally 18.9% of them had the experience of finding Plasmodium at work, and 97.9% of them considered it was necessary or very necessary to do Plasmodium microscopy examinations. However, 57.9% and 8.4% of them considered Plasmodium microscopy examinations increased their work load and work difficulty, respectively. The average correct rates of knowledge tests on malaria before and after training were 72.5% and 91.6% respectively (P0.05). The average mark of Plasmodium microscopic tests was 25.3 points (full mark being 50 points), and the passing rate (or = 30 points) was 58.9%.The working experience of staff for Plasmodium microscopy examinations in Changzhou City is relatively poor, and the related training should be enhanced.

High genetic heterogeneity is an important characteristic of hepatitis C virus (HCV) that contributes to its ability to establish persistent infection. The hypervariable region 1 (HVR1) that includes the first 27 amino acid residues of the E2 envelope glycoprotein is the most variable region within the HCV polyprotein. HVR1 plays a major role in both HCV cell entry and immune evasion, but the respective contribution of specific amino acid residues is still unclear. Our mutagenesis analyses of HCV pseudoparticles and cell culture-derived HCV using the H77 isolate indicate that five residues at positions 14, 15, and 25-27 mediate binding of the E2 protein to the scavenger receptor class B, type I receptor, and any residue herein is indispensable for HCV cell entry. The region spanning positions 16-24 contains the sole neutralizing epitope and is dispensable for HCV entry, but it is involved in heparan binding. More importantly, this region is necessary for the enhancement of HCV entry by high density lipoprotein and interferes with virus neutralization by E2-neutralizing antibodies. Residues at positions 1-13 are also dispensable for HCV entry, but they can affect HCV infectivity by modulating binding of the envelope protein to scavenger receptor class B, type I. Mutations occurring at this site may confer resistance to HVR1 antibodies. These findings further our understanding about the mechanisms of HCV cell entry and the significance of HVR1 variation in HCV immune evasion. They have major implications for the development of HCV entry inhibitors and prophylactic vaccines.

T helper-1 (Th-1)-type immune responses play an important role in viral clearance during infection with hepatitis B virus (HBV). Unmethylated CpG motifs present in bacterial DNA can activate toll-like receptor 9 (TLR9) signals and act as potent adjuvants to induce Th-1-type immune responses. Here, a mini-plasmid with 812 base pairs in length was constructed and used as a vector to prepare a series of plasmids containing 3-21 copies of D-type CpG motifs. In vitro, these CpG-enriched plasmids strongly stimulated proliferation of human peripheral blood mononuclear cells (PBMCs) and enhanced secretion of interferon-γ (IFN-γ) and interleukin-12 (IL-12). The responses of the PBMCs from healthy individuals to the plasmids were stronger than those obtained from HBV-infected individuals. Contrary to the strong Th-2-biased response induced by surface antigen of hepatitis B virus (HBsAg) plus alum adjuvant, immunization of BALB/c mice with HBsAg plus these plasmids induced a strong Th-1-biased response. The plasmids increased the titers of HBsAg-specific total immunoglobulin G (IgG) and IgG(2a). HBsAg-specific IL-2 and IFN-γ production and cytotoxic activity were also enhanced in the presence of the plasmids. The strength of the immune responses positively correlated with the number of CpG motifs in the plasmids. These results indicate that the use of CpG-enriched plasmids as an adjuvant to recombinant HBsAg could provide a promising and cost-effective approach for the development of efficacious therapeutic vaccines against HBV infection.

Dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin (DC-SIGN) is a cellular receptor for hepatitis C virus for the binding of viral envelope glycoprotein E2. Interaction of DC-SIGN with the E2 may evoke cellular signal transduction implicated in viral pathogenesis. We developed a cell model with DC-SIGN transient transfection to study p38 mitogen-activated protein kinase (MAPK) signaling pathway in response to the E2 treatment. HEK293T and HeLa were DC-SIGN-deficient cell lines. DC-SIGN was detectable at the surface of HEK293T and HeLa transfected with DC-SIGN, and the levels of DC-SIGN were high in transfected-HEK293T as compared with HeLa. The transfected-HEK293T displayed ability for the E2 binding. In the transfected-HEK293T, level of p38 MAPK phosphorylation was increased upon the E2 treatment and reduced following blockage of DC-SIGN with an antibody against DC-SIGN. Phosphorylation of downstream transcription factor activating transcription factor (ATF)-2 was also up-regulated by the E2 via DC-SIGN. Similar results were obtained with NIH3T3 cells stably expressing DC-SIGN and Huh7 cells. Our results indicate that DC-SIGN transient expression in HEK293T is a useful cell model for investigating p38 MAPK pathway triggered by the E2, which may provide information for understanding cellular receptors-mediated signaling events and the viral pathogenesis.

Hepatitis B virus encoded X protein (HBx) is a trans-activating protein that may be involved in hepatocarcinogenesis, although few natural effectors of HBx that participate in this process have been identified. We screened, by comparative proteomics method, effectors of HBx associated with hepatocarcinogenesis.HBx positive and negative HepG2 cells were constructed and expression patterns of cellular proteins were obtained by high resolution, two dimensional electrophoresis. Comprehensive analyses of proteins associated with hepatocellular carcinoma (HCC) were focused on the differently expressed proteins (more than two-fold increase or decrease, P0.05) from HBx positive and negative HepG2 cells. For peptide mass fingerprinting, protein spots with different intensity between HBx positive and negative HepG2 cells were directly cut out of gels and processed for matrix assisted, laser desorption/ionization, time of flight mass spectrometry and liquid chromatography-tandem mass spectrometry (LC-ESI-MS/MS) analysis.The mean number of protein spots for HBx negative and HBx positive HepG2 cells were 2095 +/- 137 and 2188 +/- 105, respectively. The analysis of paired cells showed 75 spots with significant differences in expression between HBx negative and HBx positive cells: 37 spots corresponding to 32 different proteins; 25 proteins were upregulated, 7 downregulated. We found 7 proteins not previously reported differentially expressed in HBx positive HepG2 cells. Variations in protein accumulation were confirmed for four (HSP90AB1, BCL2 associated athanogene 2, nucleophosmin and chloride intracellular channel 1) by Western blotting in HBx positive HepG2 cells.Numerous effectors of HBx that may promote the development of HCC are identified, of which 7 are newly noted in HepG2 cells. Several of these effectors of HBx may help in elucidating the roles of HBx in hepatocarcinogenesis and diagnostics or targets for therapeutic intervention.

Aim: To observe the influence of HCV F protein on apoptosis of HepG2 cells, and explore the association between F protein and NF-κB signal pathway. Methods: HCV 1b F gene containing HepG2-F cells and HCV 1b C gene containing HepG2-C cells were treated with 100 IU/mL TNF-α, and analyzed by flow cytometry, Western blotting, and dual luciferase reporter assay. Empty plasmid pcDNA3.1+ containing HepG2-3.1 cells were used as control. Results: (i) With the treatment of TNF-α for 18 h, the apoptosis rates (AR) of HepG2-F and HepG2-3.1 cells were 0.41% (± 0.11%) and 37.43% (± 2.03%) respectively, while that of HepG2-C was 4.07% (± 0.18%). At 36 h after TNF-α treatment, the AR of HepG2-F and HepG2-3.1 cells were 10.03% (± 0.41%) and 44.63% (± 3.37%), and that of HepG2-C was 14.95% (± 0.85%). (ii) After the treatment of TNF-α for 0.5–18 h, the p65 contents in the whole cells of HepG2-F and HepG2-3.1 showed no significant difference (P = 0.34, t = 1.08), while the p65 contents in the nucleus of HepG2-F and HepG2-3.1 cells were 3.8–1.9 times and 1.8–1.0 times higher than that in the non-treated cells (P = 0.013, t = 4.25). (iii) The relative luciferase unit (RLU) of the HepG2 cells, co-transfected with pcDNA3.1-F and pNF-κB-luc, and then treated with TNF-α (100 IU/mL) for 18 h, showed a pcDNA3.1-F dose-dependent increase. Conclusion: HCV F protein can over-activate NF-κB signal pathway, which makes HepG2-F cells able to resist TNF-α induced apoptosis.

Hepatitis C virus (HCV) core protein is considered to be an attractive candidate for inclusion in a protective vaccine. However, this protein may attenuate the development of systemic immune responses because of its immunomodulatory properties. In this study, a eukaryotic expression plasmid, pCI-C, and an in vivo-inducible prokaryotic expression plasmid, pZW-C, for HCV core protein were constructed and transformed into attenuated Salmonella typhimurium aroA strain SL7207. The recombinant expression plasmids SL7207/pCI-C and SL7207/pZW-C were used to orally immunize BALB/c mice, and immune responses specific to core protein were assessed. Immunization with bacteria SL7207/pCI-C led to a persistent decrease in the percentage of CD3(+)CD4(+) T cells and triggered weak anti-core IgG production. Splenocytes from SL7207/pCIC-immunized mice developed relatively weak proliferation response, low interferon-gamma secretion, and inferior cytotoxic activity compared with those from mice immunized with SL7207/pZW-C. Boost immunization with SL7207/pCI-C yielded limited improvement in the immune response, whereas boost with bacteria SL7207/pZW-C enhanced immune responses significantly. These results suggest that de novo host synthesis of native HCV core protein may cut down the induction of immune responses. Attenuated S. typhimurium carrying HCV core protein could efficiently activate systemic cellular and humoral responses, and may be a promising strategy for the development of core-based HCV vaccines.

A total amount of 117 candidate chromosomal sequences were screened for the genomic signatures of Bacillus anthracis by a 2-step approach. Out of them, 19 genomic signatures sequences were selected, among which, 6 genomic signatures were competent as the target sequence of TaqMan real-time PCR method. With the most significant alignment and specificity, fragment C04, together with pagA gene and capB gene from virulence plasmids pX01 and pX02, was selected to establish a TaqMan real-time PCR assay. For each target sequence, as little as 10 to 100 copies per reaction could be detected. Twelve bacterial species including 7 from Bacillus cereus group which were closely related to Bacillus anthracis were used to test the specificity of this assay. Data revealed that the assay gained a 100% specificity. Further performance of the assay was assessed with 10 simulative contaminated environmental samples and 20 negative control environmental samples; all of the Bacillus anthracis contaminated samples gave strong positive signals while the control samples were negative. This specific and sensitive real-time PCR assay could be used in rapid confirmation or exclusion of potential bio-attacks and the diagnosis of anthrax.

Hepatitis C virus (HCV) F protein is a newly identified protein encoded by an alternative open reading frame that +1 overlaps core-encoding gene. It has been found that regulation of c-myc and p53 genes by HCV core protein is involved in liver cancer genesis. We wondered whether HCV F protein exerts similar or adverse regulatory effects on the transcription of c-myc and p53 genes.HCV F gene-containing, plasmid pcDNA3.1-F and HCV core gene-containing pcDNA3.1-C were constructed and transiently transfected into HepG(2) cells. Real-time quantitative PCR or Western blotting was used to determine the changes at transcription or translation levels of c-myc and p53 genes.The transcription level of c-myc was much higher in pcDNA3.1-F transfected cells than those without plasmid transfected. Whereas the level of p53 transcription in pcDNA3.1-F transfected cells was lower than those in the parental cells. Moreover, levels of c-myc expression were up-regulated and those of p53 expression were down-regulated by HCV F protein.HCV F protein is of regulatory properties in cellular oncogene c-myc and anti-oncogene p53, which may be implicated in the formation of hepatocellular carcinoma.

To evaluate the impact of universal salt iodization using monitoring data on correctional status of iodine deficiency and hospitalized thyroid diseases.Retrospective survey was conducted to collect medical records of hospitalized thyroid disease cases. Routine monitoring data on population iodine nutrition status and goiter prevalence were analyzed.The coverage of adequately iodized salt was consistently above 95%. Hospitalization rate of thyroid diseases rose steadily, and peaked at 54.5 per 100,000. The proportion of hospitalized thyroid disease among hospitalized diseases also rose with female and those aged above 40 years old mostly affected. The proportion of hospitalized hyperthyroidism among total hospitalized thyroid disease rose from 13.6% to 34.7%.Universal salt iodization might eliminate iodine deficiency while other impact still exists. However, the benefits of universal salt iodization should be far overweight the adverse effects.

The 16S rDNA specific primers were designed for rapid detection of Pseudomonas aeruginosa (PA) by the fluorescence quantitative PCR (FQ-PCR) assay, based upon multiple sequence alignment and phylogenetic tree analysis of the 16S rDNAs of over 20 bacteria. After extraction of PA genomic DNA, the target 16S rDNA fragment was amplified by PCR with specific primers, and used to construct recombinant pMDT-Pfr plasmid, the dilution gradients of which were subjected to the standard quantitation curve in FQ-PCR assay. Different concentrations of PA genomic DNA were detected by FQ-PCR in a 20microL of reaction system with SYBR Green I. At the same time, various genomic DNAs of Staphylococcus aureus, Salmonella typhi, Shigella flexneri, Proteus vulgaris, Staphylococcus epidermidis, Escherichia coli, and Mycobacterium tuberculosis were used as negative controls to confirm specificity of the FQ-PCR detection assay. Results demonstrated that the predicted amplified product of designed primers was of high homology only with PA 16S rDNA, and that sensitivity of the FQ-PCR assay was of 3.6pg/microL of bacterial DNA or (2.1 x 10(3) +/- 3.1 x 10(2)) copies/microL of 16S rDNA, accompanied with high specificity, and that the whole detection process including DNA extraction could be completed in about two hours. In contrast to traditional culture method, the FQ-PCR assay targeting 16S rDNA gene can be used to detect PA rapidly, which exhibits perfect application prospect in future.

BACKGROUND: Hepatitis B virus encoded X protein (HBx) is a trans-activating protein that may be involved in hepatocarcinogenesis, although few natural effectors of HBx that participate in this process have been identified. We screened, by comparative proteomics method, effectors of HBx associated with hepatocarcinogenesis. METHODS: HBx positive and negative HepG2 cells were constructed and expression patterns of cellular proteins were obtained by high resolution, two dimensional electrophoresis. Comprehensive analyses of proteins associated with hepatocellular carcinoma (HCC) were focused on the differently expressed proteins (more than two-fold increase or decrease, P < 0.05) from HBx positive and negative HepG2 cells. For peptide mass fingerprinting, protein spots with different intensity between HBx positive and negative HepG2 cells were directly cut out of gels and processed for matrix assisted, laser desorption/ionization, time of flight mass spectrometry and liquid chromatography-tandem mass spectrometry (LC-ESI-MS/MS) analysis. RESULTS: The mean number of protein spots for HBx negative and HBx positive HepG2 cells were 2095 +/- 137 and 2188 +/- 105, respectively. The analysis of paired cells showed 75 spots with significant differences in expression between HBx negative and HBx positive cells: 37 spots corresponding to 32 different proteins; 25 proteins were upregulated, 7 downregulated. We found 7 proteins not previously reported differentially expressed in HBx positive HepG2 cells. Variations in protein accumulation were confirmed for four (HSP90AB1, BCL2 associated athanogene 2, nucleophosmin and chloride intracellular channel 1) by Western blotting in HBx positive HepG2 cells. CONCLUSIONS: Numerous effectors of HBx that may promote the development of HCC are identified, of which 7 are newly noted in HepG2 cells. Several of these effectors of HBx may help in elucidating the roles of HBx in hepatocarcinogenesis and diagnostics or targets for therapeutic intervention.

Since cell signal transduction plays an important role in disclosing the nature of human diseases, the pathogenesis of viruses may result from the disturbance of intracellular signal cascades caused by viral proteins. Hepatitis C virus (HCV) is a main causative agent of severe human liver disorders worldwide. So far, the mechanisms of HCV pathogenicity remain unclear. Envelope protein 2 (E2) of HCV is thought to be responsible for initiating virus attachment to host cells, which is a prerequisite of HCV infection. We assume that some early events of HCV pathogenic effects may result from the interaction of HCV E2 protein with its cellular receptor (human CD81), which could regulate cell proliferation and differentiation. To test this hypothesis, the effects of HCV E2 protein on MAPK/ERK pathway in Molt-4 and U937 cells with or without human CD81 expression were investigated. The results showed that HCV E2 protein could specifically activate the MAPK/ERK pathway, and such activation was inhibited by monoclonal antibodies against CD81 or HCV E2, serum antibodies from HCV infected patients, and upstream MEK1 inhibitor PD98059. Moreover, HCV E2-driven MAPK/ERK or downstream transcription factor Elk-1 activation was completely blocked in the presence of PD98059. These findings strongly suggest that the regulation of transmembrane signaling by HCV E2 protein via its receptor(s) on host cells might contribute to the development of HCV-related diseases.

Although reliable assays for the detection of hepatitis C virus and E virus became available, still 10%-20% hepatitis are not caused by hepatitisA-E virus[1-3]. In 1996, two research groups isolated this agent independently and almost simultaneously and named hepatitis G virus and GB virus C, respectively[4-7]. The nucleotide and amino acid homologies between GBV-C and hepatitis G virus (HGV) were 85% and 95%[5-7]. Therefore, GBV-C and HGV were considered as two different isolates of the same virus, referred to as HGV in this paper. HGV is a single-strand, positive sense RNA virus with approximately 9.4 kb in length, and classified as a member of Flaviviridae. HGV is mainly transmitted through transfusion and could be responsible for chronic liver infection. HGV RNA has been detected in the serum of intravenous drug users (IVDUs), volunteer and commercial blood donors, and patients with cryptogenic hepatitis[8-10]. Until now, RT-PCR is the most commonly used method for the diagnosis of HGV infection. It is necessary to develop a more convenient antibody detection assay. The baculovirus expression system is of a strong polyhedrin promoter[11], and can carry out many types of postranslation modification for a variety of proteins. Most of the expressed proteins were usually shown to be antigenic, immunological, and functionally similar to their authentic counterparts[12-16]. In this study, we used the baculovirus expression system to express HGV NS5 protein in Sf9 cells, and studied its immunogenecity.