Screening and identification of bioactive compounds from citrus against non-structural protein 3 protease of hepatitis C virus genotype 3a by fluorescence resonance energy transfer assay and mass spectrometry

BACKGROUND Hepatitis C virus genotype 3a(HCV G3a)is highly prevalent in Pakistan.Due to the elevated cost of available Food and Drug Administration-approved drugs against HCV,medicinal natural products of potent antiviral activity should be screened for the cost-effective treatment of the disease.Furthermore,from natural products,active compounds against vital HCV proteins like non-structural protein 3(NS3)protease could be identified to prevent viral proliferation in the host.AIM To develop cost-effective HCV genotype 3a NS3 protease inhibitors from citrus fruit extracts.METHODS Full-length NS3 without co-factor non-structural protein 4A(NS4A)and codon optimized NS3 protease in fusion with NS4A were expressed in Escherichia coli.The expressed protein was purified by metal ion affinity chromatography and gel filtration.Citrus fruit extracts were screened using fluorescence resonance energy transfer(FRET)assay against the protease and polyphenols were identified as potential inhibitors using electrospray ionization-mass spectrometry(MS)/MS technique.Among different polyphenols,highly potent compounds were screened using molecular modeling approaches and consequently the most active compound was further evaluated against HCV NS4A-NS3 protease domain using FRET assay.RESULTS NS4A fused with NS3 protease domain gene was overexpressed and the purified protein yield was high in comparison to the lower yield of the full-length NS3 protein.Furthermore,in enzyme kinetic studies,NS4A fused with NS3 protease proved to be functionally active compared to full-length NS3.So it was concluded that co-factor NS4A fusion is essential for the purification of functionally active protease.FRET assay was developed and validated by the half maximal inhibitory concentration(IC50)values of commercially available inhibitors.Screening of citrus fruit extracts against the native purified fused NS4A-NS3 protease domain showed that the grapefruit mesocarp extract exhibits the highest percentage inhibition 91%of protease activity.Among the compounds identified by LCMS analysis,hesperidin showed strong binding affinity with the protease catalytic triad having S-score value of-10.98.CONCLUSION Fused NS4A-NS3 protease is functionally more active,which is effectively inhibited by hesperidin from the grapefruit mesocarp extract with an IC50 value of 23.32μmol/L.

Retraction Note:Screening and identification of bioactive compounds from citrus against non-structural protein 3 protease of hepatitis C virus genotype 3a by fluorescence resonance energy transfer assay and mass spectrometry

Retraction note:Khan M,Rauf W,Habib F,Rahman M,Iqbal M.Screening and identification of bioactive compounds from citrus against non-structural protein 3 protease of hepatitis C virus genotype 3a by fluorescence resonance energy transfer assay and mass spectrometry.World J Hepatol 2020;12(11):976-992 PMID:33312423 DOI:10.4254/wjh.v12.i11.976.The online version of the original article can be found at https://www.wjgnet.com/1948-5182/full/v12/i11/976.htm.

Inhibition of Hepatitis C Virus Genotype 1a Non-Structural Proteins by Small Interference RNA in Human Hepatoma Cell Lines

Hepatitis C virus (HCV) infection and associated liver diseases are still challenging and represent a significant health care burden around the world. Although, the treatment strategies have been improved by the development of novel direct-acting antivirals, but such therapeutic options are still expensive and beyond the financial range of the most infected individuals in developing or even in resource replete countries. It demands an urgent need to search novel and improved alternate treatment strategies to treat the infection. The present study was aimed to develop an in vitro stable cell culture system, persistently expressing HCV genotype 1a non-structural genes and to characterize the inhibitory effects of synthetic siRNAs (short interference RNA) directed against the most conserved regions of nonstructural genes in an in vitro cell culture model. The continuous expression of nonstructural genes for more than 30 days post transfection was detected by reverse transcription polymerase chain reaction (RT-PCR) and Western blot analysis in stable human hepatoma cell line (Huh-7). The gene expression studies revealed significantly reduced gene expression of HCV nonstructural genes (i.e., NS2, NS4A and NS5A) both at mRNA and protein levels when treated against genome specific synthetic siRNAs in stable cell lines (51%, 47% and 54% respectively, p < 0.05). Similarly, a vivid decrease in HCV viral titer was exhibited by synthetic siRNAs in an in vitro viral replicate cell culture model (58%, 48% and 50%, respectively, p < 0.05) determined by quantitative Real-Time PCR (qPCR). Our data indicate that siRNA mediated gene silencing may be considered a promising alternate treatment strategy against HCV in combination with other effective therapeutic regimens in future.

Interleukin-28 and hepatitis C virus genotype-4:Treatment-induced clearance and liver fibrosis

AIM:To investigate the association between interleukin-28B(IL28B) genotype and response to treatment and hepatic fibrosis in patients with hepatitis C virus(HCV) genotype 4.METHODS:Two hundred and one HCV-genotype 4 patients were included.All patients were treated with Peginterferon alph2a/Ribavirin for 48 wk.End of treatment response(ETR) was defined as loss of detectable serum HCV RNA at the end of treatment.Sustained viral response(SVR) was defined as loss of detectable serum HCV RNA at the end of 24 wk follow up.Genotyping of IL28B rs12979860 was performed using the TaqMan assay.We used logistic regression to estimate the adjusted odds ratio(aOR) and 95%CI.RESULTS:The study included 201 HCV-genotype 4 patients.The majority of patients were men(89.6%),with a median age of 47 years,inter-quartile range(40-51).Approximately 62.5% of patients had ETR,and 49.6% had SVR.Individuals who achieved SVR were more likely to be younger(χ 2 = 4.91,P = 0.027),and less likely to have fibrosis(χ 2 = 15.54,P < 0.0001),or inflammation(χ 2 = 7.58,P = 0.006).The genotype distribution of rs12979860 was 36.2%,49.0% and 14.8% for genotypes CC,CT,and TT,respectively.In these participants,rs12979860 genotype distribution did not differ by gender(P = 0.466),pretreatment viral load(P = 0.600),inflammation(P = 0.435),or fibrosis(P = 0.291).The frequencies of IL28B rs12979860 genotypes were TT(14.8%),CT(49.0%),and CC(36.2%).Compared to rs12979860 genotype TT,aORs(95%CI) for ETR and SVR were:CC genotype,[17.55(5.34-57.69) and 5.92(2.09-16.76),respectively];CT genotype,[5.15(1.80-14.78) and 2.48(0.94-6.52),respectively].In the current study,the patients who did not achieve ETR or SVR had a lower prevalence of rs12979860 CC(17.4% and 23.3%,respectively) than individuals who had ETR or SVR(47.9% and 47.2%,respectively).Individuals with rs12979860 CC genotype had approximately 6 times the odds of SVR compared to individuals with TT genotype(aOR = 5.92;95%CI:2.09-16.76).Similarly,patients with CT genotype had SVR more often than patients with TT genotype(aOR = 2.48;95%CI:0.94-6.52).Carrying at least one copy of the C allele(genotypes CT and CC) had almost 8 times the probability of ETR compared to those with genotype rs12979860 TT(aOR = 7.87;95%CI:2.84-21.82),and approximately 3 times the odds of SVR compared to those with genotype rs12979860 TT(aOR = 3.46;95%CI:1.37-8.74).In addition,data were consistent with a significant gene-dose relationship(aOR = 4.05/allele;95%CI:2.27-7.22).The association between rs12979860 genotype and SVR was similar among those who achieved and those who did not achieve SVR.CONCLUSION:In HCV-genotype 4 patients,rs12979860 is a sensitive predictor of viral clearance,independent of viral load,age,gender or fibrosis,with no similar relation to severity of fibrosis.

Hepatitis C virus in human B lymphocytes transformed by Epstein-Barr virus in vitro by in situ reverse transcriptase-polymerase chain reaction

AIM: To study persistence and replication of hepatitis C virus (HCV) in patients' peripheral blood mononuclear cells (PBMC) cultured in vitro. METHODS: Epstein Barr virus (EBV) was used to transform the hepatitis C virus from a HCV positive patient to permanent lymphoblastoid cell lines (LCL). Positive and negative HCV RNA strands of the cultured cells and growth media were detected by reverse transcriptase-polymerase chain reaction (RT-PCR) each month. Core and NS5 proteins of HCV were further tested using immunohistochemical SP method and in situ RT-PCR. RESULTS: HCV RNA positive strands were consistently detected the cultured cells for one year. The negative-strand RNA in LCL cells and the positive-strand RNA in supernatants were observed intermittently. Immunohistochemical results medicated expression of HCV NS3 and C proteins in LCL cytoplasm mostly. The positive signal of PCR product was dark blue and mainly localized to the LCL cytoplasm. The RT-PCR signal was eliminated by overnight RNase digestion but not DNase digestion. CONCLUSION: HCV may exist and remain functional in a cultured cell line for a long period.

Contributions of transgenic mouse studies on the research of hepatitis B virus and hepatitis C virus-induced hepatocarcinogenesis

Transgenic mouse technology has enabled the investigation of the pathogenic effects, including those on development, immunological reactions and carcinogenesis, of viral genes directly in living organism in a real-time manner. Although viral hepatocarcinogenesis comprises multiple sequences of pathological events, that is, chronic necroinflammation and the subsequent regeneration of hepatocytes that induces the accumulation of genetic alterations and hepatocellular carcinoma(HCC), the direct action of viral proteins also play significant roles. The pathogenesis of hepatitis B virus X and hepatitis C virus(HCV) core genes has been extensively studied by virtue of their functions as a transactivator and a steatosis inducer, respectively. In particular, the mechanism of steatosis in HCV infection and its possible association with HCC has been well studied using HCV core gene transgenic mouse models. Although transgenic mouse models have remarkable advantages, they are intrinsically accompanied by some drawbacks when used to study human diseases. Therefore, the results obtained from transgenic mouse studies should be carefully interpreted in the context of whether or not they are well associated with human pathogenesis.

In vitro inhibitory analysis of consensus siRNAs against NS3 gene of hepatitis C virus 1a genotype

Objective: To explore inhibitory effects of genome-specific, chemically synthesized siRNAs(small interference RNA) against NS3 gene of hepatitis C virus(HCV) 1a genotype in stable Huh-7(human hepatoma) cells as well as against viral replication in serum-inoculated Huh-7 cells. Methods: Stable Huh-7 cells persistently expressing NS3 gene were produced under antibiotic gentamycin(G418) selection. The cell clones resistant to 1 000 μg antibiotic concentration(G418) were picked as stable cell clones. The NS3 gene expression in stable cell clone was confirmed by RT-PCR and Western blotting. siRNA cell cytotoxicity was determined by MTT cell proliferation assay. Stable cell lines were transfected with sequence specific siRNAs and their inhibitory effects were determined by RT-PCR, real-time PCR and Western blotting. The viral replication inhibition by siRNAs in serum inoculated Huh-7 cells was determined by real-time PCR. Results: RT-PCR and Western blot analysis confirmed NS3 gene and protein expression in stable cell lines on day 10, 20 and 30 post transfection. MTT cell proliferation assay revealed that at most concentrated dose tested(50 nmol/L), siRNA had no cytotoxic effects on Huh-7 cells and cell proliferation remained unaffected. As demonstrated by the siRNA time-dependent inhibitory analysis, siRNA NS3-is44 showed maximum inhibition of NS3 gene in stable Huh-7 cell clones at 24(80%, P=0.013) and 48 h(75%, P=0.002) post transfection. The impact of siRNAs on virus replication in serum inoculated Huh-7 cells also demonstrated significant decrease in viral copy number, where siRNA NS3-is44 exhibited 70%(P<0.05) viral RNA reduction as compared to NS3-is33, which showed a 64%(P<0.05) decrease in viral copy number. siRNA synergism(NS3-is33 + NS3-is44) decreased viral load by 84%(P<0.05) as compared to individual inhibition by each siRNA(i.e., 64%–70%(P<0.05) in serum-inoculated cells. Synthetic siRNAs mixture(NS5Bis88 + NS3-is33) targeting different region of HCV genome(NS5B and NS3) also decreased HCV viral load by 85%(P< 0.05) as compared to siRNA inhibitory effects alone(70% and 64% respectively, P<0.05). Conclusions: siRNAs directed against NS3 gene significantly decreased m RNA and protein expression in stable cell clones. Viral replication was also vividly decreased in serum infected Huh-7 cells. Stable Huh-7 cells expressing NS3 gene is helpful to develop anti-hepatitis C drug screening assays. siRNA therapeutic potential along with other anti-HCV agents can be considered against hepatitis C.

Hepatitis C virus infection and insulin resistance

Approximately 170 million people worldwide are chronically infected with hepatitis C virus(HCV).Chronic HCV infection is the leading cause for the development of liver fibrosis,cirrhosis,hepatocellular carcinoma(HCC)and is the primary cause for liver transplantation in the western world.Insulin resistance is one of the pathological features in patients with HCV infection and often leads to development of typeⅡdiabetes.Insulin resistance plays an important role in the development of various complications associated with HCV infection.Recent evidence indicates that HCV associated insulin resistance may result in hepatic fibrosis,steatosis,HCC and resistance to anti-viral treatment.Thus,HCV associated insulin resistance is a therapeutic target at any stage of HCV infection.HCV modulates normal cellular gene expression and interferes with the insulin signaling pathway.Various mechanisms have been proposed in regard to HCV mediated insulin resistance,involving up regulation of inflammatory cytokines,like tumor necrosis factor-α,phosphorylation of insulin-receptor substrate-1,Akt,up-regulation of gluconeogenic genes like glucose 6 phosphatase,phosphoenolpyruvate carboxykinase 2,and accumulation of lipid droplets.In this review,we summarize the available information on how HCV infection interferes with insulin signaling pathways resulting in insulin resistance.

Antiviral treatment of hepatitis C virus infection and factors affecting efficacy

Hepatitis C virus(HCV)infection is the leading cause of chronic liver-related diseases,including cirrhosis,liver failure,and hepatocellular carcinoma.Currently,no effective vaccine is available for HCV infection.Polyethylene glycol interferon-α(PegIFN-α)in combination with ribavirin(RBV)is the standard of care(SOC)for chronic hepatitis C.However,the efficacy of PegIFN-αand RBV combination therapy is less than 50%for genotype 1HCV,which is the dominant virus in humans.In addition,IFN and RBV have several severe side effects.Therefore,strategies to improve sustained virological response(SVR)rates have been an important focus for clinical physicians.The serine protease inhibitors telaprevir and boceprevir were approved by the United States Food and Drug Administration in 2011.The addition of HCV protease inhibitors to the SOC has significantly improved the efficacy of treatments for HCV infection.Several direct-acting antiviral drugs currently in late-stage clinical trials,both with and without pegIFN and RBV,have several advantages over the previous SOC,including higher specificity and efficacy,fewer side effects,and the ability to be administered orally,and might be optimal regimens in the future.Factors affecting the efficacy of anti-HCV treatments based on IFN-αinclude the HCV genotype,baseline viral load,virological response during treatment,host IL28B gene polymorphisms and hepatic steatosis.However,determining the effect of the above factors on DAA therapy is necessary.In this review,we summarize the development of antiHCV agents and assess the main factors affecting the efficacy of antiviral treatments.

Role of genetic polymorphisms in hepatitis C virus chronic infection

AIM: To analyze the host genetics factors influencing the clinical course and the response to antiviral treatment in patients with chronic hepatitis C(CHC).METHODS: We conducted an electronic search on the Pub Med and MEDLINE(2000-2014) databases and Cochrane library(2000-2014). A total of 73 articles were retrieved and their data were extensively evaluated and discussed by the authors and then analyzed in this review article.RESULTS: Several studies associated polymorphisms in the interleukin 28 B gene on chromosome 19(19q13.13) with a spontaneous viral clearance in acute hepatitis C and with the response to pegylated interferon(PegIFN)-based treatment in chronic hepatitis C patients. Other investigations demonstrated that inosine triphosphate pyrophosphatase genetic variants protect hepatitis C virus-genotype-1 CHC patients from ribavirin-induced anemia, and other studies that a polymorphism in the patatin-like phospholipase domain-containing protein 3 was associated with hepatic steatosis in CHC patients. Although not conclusive, some investigations suggested that the vitamin D-associated polymorphisms play an important role in the achievement of sustained virologic response in CHC patients treated with Peg-IFN-based antiviral therapy. Several other polymorphisms have been investigated to ascertain their possible impact on the natural history and on the response to treatment in patients with CHC, but the data are preliminary and warrant confirmation. CONCLUSION: Several genetic polymorphisms seem to influence the clinical course and the response to antiviral treatment in patients with CHC, suggesting individualized follow up and treatment strategies.

Risk Factors, Clinical Features, Baseline Alanine Aminotransferase and CD4+ Count of Children with HIV Co-Infection with Hepatitis B and C at a Tertiary Hospital in Southwest Nigeria

Background: Human immunodeficiency virus and hepatitis B and C viruses are endemic in sub- Saharan African countries including Nigeria. Researchers have studied the burden of co-infection of HIV with hepatitis B and hepatitis C but the risk factors and clinical presentation have not been much addressed especially in children. Methodology: This was a prospective cross sectional study that determined the prevalence, risk factors, clinical features, baseline CD4+ count, CD4+ percentage, and alanine aminotransferase (ALT) of newly diagnosed, HAART na?ve HIV co-infection among children who were managed at a Tertiary Hospital in Ilorin, Nigeria. Result: Of the 60 HIV- infected children recruited, 11.7% had HIV co-infection with HBV or HCV. Children with co-infec- tions (mean age 8.43 ± 2.37 years) were significantly older than their HIV mono-infected counterparts (mean age 5.25 ± 3.96 years) (p = 0.011). There was no significant difference between HIV monoinfection and HIV co-infection with respect to gender (p = 0.758), ethnicity (p = 0.707), religion of parents (p = 0.436), family type (p = 0.184), social class (p = 0.535), previous transfusion (p = 0.053), scarification (p = 0.612), female genital mutilation (p = 0.778), and sharing of clippers (p = 0.806). The mean BMI, immunological staging (p = 0.535), baseline ALT (p = 0.940), and mean baseline CD4+ count (p = 0.928) were comparable. However, the body mass index of HIV co-infec- ted children decreased with age up till age 10 years. Conclusion: There were no risk factors, nor clinical features predictive of co-infection identified in this study. Co-infection did not negatively impact baseline, CD4+ count and ALT.

Zika virus non-structural protein 4B interacts with DHCR7 to facilitate viral infection

Zika virus(ZIKV)evolves non-structural proteins to evade immune response and ensure efficient replication in the host cells.Cholesterol metabolic enzyme 7-dehydrocholesterol reductase(DHCR7)was recently reported to impact innate immune responses in ZIKV infection.However,the vital non-structural protein and mechanisms involved in DHCR7-mediated viral evasion are not well elucidated.In this study,we demonstrated that ZIKV infection facilitated DHCR7 expression.Notably,the upregulated DHCR7 in turn facilitated ZIKV infection and blocking DHCR7 suppressed ZIKV infection.Mechanically,ZIKV non-structural protein 4B(NS4B)interacted with DHCR7 to induce DHCR7 expression.Moreover,DHCR7 inhibited TANK-binding kinase 1(TBK1)and interferon regulatory factor 3(IRF3)phosphorylation,which resulted in the reduction of interferon-beta(IFN-β)and interferon-stimulated genes(ISGs)productions.Therefore,we propose that ZIKV NS4B binds to DHCR7 to repress TBK1 and IRF3 activation,which in turn inhibits IFN-βand ISGs,and thereby facilitating ZIKV evasion.This study broadens the insights on how viral non-structural proteins antagonize innate immunity to facilitate viral infection via cholesterol metabolic enzymes and intermediates.

血清APPL1、CTHRC1、胱抑素C水平联合检测诊断慢性HBV感染肝硬化患者Child-Pugh分级的价值

目的:观察血清磷酸酪氨酸衔接蛋白1(APPL1)、胶原三股螺旋重复蛋白1(CTHRC1)、胱抑素C水平联合检测诊断慢性乙型肝炎病毒(HBV)感染肝硬化患者Child-Pugh分级的价值。方法:选取2021年1月至2023年1月该院收治的136例慢性HBV感染肝硬化患者进行前瞻性研究,设为研究组。选取同期于该院体检的136名健康者为对照组。比较两组血清APPL1、CTHRC1、胱抑素C水平;比较不同Child-Pugh分级慢性HBV感染肝硬化患者入院时血清APPL1、CTHRC1、胱抑素C水平;采用Spearman相关性分析慢性HBV感染肝硬化患者入院时血清APPL1、CTHRC1、胱抑素C水平与Child-Pugh分级的相关性;采用受试者工作特征(ROC)曲线评估慢性HBV感染肝硬化患者入院时血清APPL1、CTHRC1、胱抑素C水平联合检测诊断Child-Pugh分级的价值。结果:入院时,研究组血清APPL1、CTHRC1、胱抑素C水平均高于对照组,差异有统计学意义(P<0.05);入院时,Child-Pugh分级为C级慢性HBV感染肝硬化患者血清APPL1、CTHRC1、胱抑素C水平均高于B级、A级者,且B级者高于A级者,差异均有统计学意义(P<0.05);Spearman相关性分析结果显示,慢性HBV感染肝硬化患者入院时血清APPL1、CTHRC1、胱抑素C水平与Child-Pugh分级均呈正相关(r>0,P<0.05);ROC曲线分析结果显示,慢性HBV感染肝硬化患者入院时血清APPL1、CTHRC1、胱抑素C水平联合检测诊断Child-Pugh分级为C级的AUC为0.931,具有较高诊断价值。结论:血清APPL1、CTHRC1、胱抑素C水平联合检测诊断慢性HBV感染肝硬化患者Child-Pugh分级的价值高于三者单项检测。

EFFECTS OF HBV preS AS A HUMORAL ENHANCER ON THE ABILITIES OF HCV E2 PROTEIN TO INDUCE IMMUNE RESPONSESIN THE DNA-IMMUNIZED MICE

Objective.To study whether the abilities of hepatitis C virus(HCV)E2 gene immunization to induce humoral and cellular immune responses to E2 protein were affected by hepatitis B virus(HBV)preS gene when they were fused in DNA-immunized mice.Methods.Mice were immunized with E2,preS-E2(preS gene was upstream of E2 gene),and E2-preS(preS gene was downstream of E2 gene)gene by their eukaryotic expression vectors,respectively.The anti-E2 or anti-preS antibodies were detected using the E2 and preS antigens.The cellular immune response to E2 pro-tein in immunized mice was presented by its survival time after injecting SP2/O myeloma cells expressing HCV E2 protein into the abdominal cavity.Results. Chimeric E2 and preS gene immunization can induce mice to develop anti-preS and anti-E2 antibodies.The number of the mice developing anti-E2 antibody and the antibody titers in preS-E2 gene-injected group were higher than those in E2-preS gene-immunized group.However,the mice injected with E2 gene did not develop the detectable anti-E2 antibodies until 12 weeks after DNA immunization.After the mice was injected with target cells,the average survival time of the mice in the group immunized with E2 gene alone was longer than that of the group injected with E2 gene fused with HBV preS and was significantly longer than that of the control(P< 0.05).Conclusion.HBV preS might be a humoral enhancer that can affect the abilities of HCV E2 protein to in-duce immune responses in DNA-immunized mice.

SAMD4 family members suppress human hepatitis B virus by directly binding to the Smaug recognition region of viral RNA

HBV infection initiates hepatitis B and promotes liver cirrhosis and hepatocellular carcinoma.IFN-α is commonly used in hepatitis B therapy,but how it inhibits HBV is not fully understood.We screened 285 human interferon-stimulated genes(ISGs)for anti-HBV activity using a cell-based assay,which revealed several anti-HBV ISGs.Among these ISGs,SAMD4A was the strongest suppressor of HBV replication.We found the binding site of SAMD4A in HBV RNA,which was a previously unidentified Smaug recognition region(SRE)sequence conserved in HBV variants.SAMD4A binds to the SRE site in viral RNA to trigger its degradation.The SAM domain in SAMD4A is critical for RNA binding and the C-terminal domain of SAMD4A is required for SAMD4A anti-HBV function.Human SAMD4B is a homolog of human SAMD4A but is not an ISG,and the murine genome encodes SAMD4.All these SAMD4 proteins suppressed HBV replication when overexpressed in vitro and in vivo.We also showed that knocking out the Samd4 gene in hepatocytes led to a higher level of HBV replication in mice and AAV-delivered SAMD4A expression reduced the virus titer in HBVproducing transgenic mice.In addition,a database analysis revealed a negative correlation between the levels of SAMD4A/B and HBV in patients.Our data suggest that SAMD4A is an important anti-HBV ISG for use in IFN therapy of hepatitis B and that the levels of SAMD4A/B expression are related to HBV sensitivity in humans.

HBsAg/截短型HCV核心蛋白融合基因对番茄的遗传转化

[目的]本研究旨在探索乙肝病毒表面抗原/截短型HCV核心蛋白融合基因在植物中表达乙肝丙肝双价抗原的可能性,以期为进一步研制植物乙肝丙肝双价口服疫苗打下基础。[方法]应用重组PCR技术将乙肝病毒(HBV)S基因连接在丙肝病毒(HCV)截短型核心蛋白序列的5'端,2者通过柔性肽(Gly4Ser)2序列相连,构建成融合基因BC。将融合基因BC克隆到植物双元表达载体pBin438上,获得pBin438BC,然后用冻融法将其转入根癌农杆菌EHA105中,侵染丽春番茄子叶和下胚轴,经预培养、共培养、脱菌培养、筛选培养、生根培养,提取抗性植株基因组DNA,进行PCR及PCR-Southern检测。[结果]获得了9株抗卡那霉素的番茄植株,5株获得阳性信号。[结论]初步表明目的基因已整合到番茄基因组中。

苦参素联合阿德福韦酯对慢性乙肝患者HBV复制及C3、C-反应蛋白的影响

目的:观察苦参素联合阿德福韦酯治疗对慢性乙肝(CHB)患者补体C3、CRP水平及乙型肝炎病毒(HBV)复制的影响。方法:164例CHB患者按随机数字表法分为观察组84例和对照组80例,两组均给予阿德福韦酯治疗48周,观察组在疗程的前24周联用苦参素。在治疗前、24周和48周分别检测补体C3、CRP及HBV-DNA水平。结果:治疗后24周及48周察组HBV-DNA转阴率均高于对照组(P<0.05);治疗后两组补体C3、CRP水平与治疗前比较均有统计学差异,且观察组补体C3水平高于对照组,CRP水平低于对照组,差异有统计学意义(P<0.05)。结论:苦参素联合阿德福韦酯治疗CHB可显著提高疗效,改善肝脏炎症活动和器官免疫功能。

乙肝病毒X蛋白通过CREB上调HBx结合蛋白促进肝癌细胞迁移

乙型肝炎病毒X蛋白(hepatitis B virus X protein,HBx)对肝癌的发生发展具有十分重要的作用.HBx具有促进肝癌迁移的作用,但其作用的分子机制不清.本研究对HBx促进肝癌细胞迁移的分子机制进行了探讨.伤口愈合和Boyden’s chamber结果表明,HBx可明显促进肝癌Hep G2细胞迁移.在稳定转染HBx的Hep G2(Hep G2-X)细胞中转染HBx结合蛋白(hepatitis B X-interacting protein,HBXIP)的RNA干扰片段,可明显抑制HBx的促迁移作用.免疫组化和实时定量PCR结果表明,HBXIP在肝癌组织中显著高表达,并且与HBx表达成正相关.荧光素酶报告基因和免疫印迹结果表明,HBx显著增强HBXIP的启动子活性和蛋白质表达水平.应用HBx的RNA干扰处理Hep G2-X细胞,HBXIP的启动子活性和蛋白质表达水平明显下降.将HBXIP启动子区的c AMP效应元件结合因子(CREB)结合位点突变后,HBx上调HBXIP的作用消失.应用CREB的RNA干扰处理肝癌细胞,在启动子水平和蛋白质水平上,HBx对HBXIP的上调作用被显著抑制.染色质免疫共沉淀结果表明,HBx能够通过CREB结合到HBXIP的启动子上,进而发挥激活HBXIP的功能.本研究结果表明,HBx促进肝癌细胞迁移的作用是通过CREB上调HBXIP实现的.这一发现对进一步揭示HBx促进肝癌细胞迁移的分子机制具有重要意义.

羧基末端截短的HBV表面抗原中蛋白反式激活c-myc表达

目的构建羧基末端截短的乙型肝炎病毒表面抗原中蛋白(MHBst)反式激活基因的消减文库,并观察其对细胞原癌基因c-myc的反式激活作用。方法以重组表达质粒pcDNA3.1(-)-MHBst和空载体pcDNA3.1(-)瞬时转染HepG2细胞,提取细胞mRNA并逆转录为cDNA,分别标记为实验组与对照组,应用抑制性消减杂交技术,构建MHBst反式激活的cDNA消减文库。针对其中的原癌基因c-myc,进一步克隆其启动子序列并构建报告基因表达载体pCAT3-c-myc,与pcDNA3.1(-)-MHBst共转染HepG2细胞,ELISA法检测报告基因氯霉素乙酰转移酶CAT的表达活性。同时,应用反转录聚合酶链反应和免疫印迹方法检测表达MHBst的细胞中c-myc基因的mRNA转录和蛋白表达水平。结果随机挑选消减文库中的50个阳性克隆进行测序和生物信息学分析,显示19种已知功能基因,涉及细胞代谢、信号转导、细胞凋亡和肿瘤发生等生物学过程。细胞内瞬时表达的MHBst蛋白能够反式激活细胞原癌基因c-myc启动子的转录活性,并且RT-PCR和Western blotting结果也证明了表达MHBst蛋白的细胞中原癌基因c-myc的表达水平明显增强。结论成功构建MHBst反式激活基因的消减文库,MHBst可以反式激活细胞原癌基因c-myc的表达,为深入了解乙型肝炎病毒致癌的分子生物学机制提供理论基础。

肝癌组织HBx和ANGPTL4表达及与临床病理、预后的关系

目的探究肝癌组织乙型肝炎病毒(HBV)x蛋白(HBx)、血管生成素样蛋白4(ANGPTL4)表达与临床病理、预后的关系。方法选择2014年12月—2017年3月手术切除的HBV相关性肝癌组织98例,另择50例癌旁组织。分析肝癌及癌旁组织中HBx、ANGPTL4的表达及与肝癌患者临床病理、预后的关系。结果与癌旁组织比较,肝癌组织HBx表达阳性率降低,ANGPTL4表达阳性率升高(P<0.05)。肝癌HBx和ANGPTL4表达与肝癌患者包膜侵犯、门静脉浸润、远处转移相关(P<0.05,P<0.01)。肝癌包膜侵犯、门静脉浸润、临床分期、远处转移、HBx、ANGPTL4表达是影响预后的因素(P<0.05,P<0.01);HBx、ANGPTL4阳性肝癌患者生存率低于阴性患者(P<0.05)。结论肝癌组织HBx和ANGPTL4表达与临床病理及预后相关,临床可通过检测其表达情况判断患者病情及预后。