丙型肝炎病毒核心区蛋白对 HepG2细胞周期、细胞凋亡和细胞端粒酶活性的影响

目的　研究丙型肝炎病毒核心区 (HCV C)蛋白对肝癌细胞HepG2细胞周期、细胞凋亡和细胞端粒酶活性的影响。方法　首先运用基因重组技术构建含有HCV C基因的真核表达质粒pcDNA3.1( ) ,然后利用脂质体介导将重组真核表达质粒转染HepG2 ,经G4 18筛选获得稳定转染HepG2细胞 (HCV C转染HepG2细胞 ) ,经逆转录 聚合酶链反应技术 (RT PCR)和间接免疫荧光法证实其中有HCV C蛋白表达。然后进行如下实验 :( 1)利用四甲基偶氮唑蓝比色 (MTT)法检测HCV C转染HepG2细胞、空白质粒转染HepG2细胞和未转染HepG2细胞的生长增殖率 ;经流式细胞术(FACS)检测 3组细胞的细胞周期 ;( 2 )经流式细胞术检测细胞凋亡率 ;( 3)经端粒重复扩增 酶联免疫吸附试验 (TRAP ELISA)法检测上述 3组细胞端粒酶活性表达情况。结果　 ( 1)HCV C转染HepG2细胞增殖率显著高于空白质粒转染HepG2和未转染HepG2细胞增殖率 ;HCV C转染HepG2细胞S期所占百分率高于未转染HepG2细胞S期所占百分率 ;( 2 )HCV C转染HepG2细胞凋亡率显著低于无HCV C转染细胞凋亡率 ;( 3)上述 3组细胞端粒酶活性之间差异无显著性。结论　 ( 1)HCV C蛋白具有抑制细胞凋亡的作用 ;( 2 )HCV C蛋白促进HepG2从G0 /1期进入S期 ,从而可能促进细胞生长增殖 ,抑制细胞凋亡 ;( 3)HCV     

人CD40 ligand基因真核表达质粒的构建及对人肝癌细胞HepG2的促凋亡作用

目的:构建含人CD40ligand(CD40L)基因的真核表达载体,并使之在人肝癌细胞HepG2中表达,研究CD40L稳定表达对HepG2细胞的影响.方法:从人外周血单个核细胞总RNA中经RT-PCR扩增出人CD40L基因,经过酶切连接进入真核表达载体pcDNATM3.1/myc-His(-)A制备重组质粒.重组质粒经酶切及测序证实人CD40L基因成功克隆进入真核表达载体pcDNATM3.1/myc-His(-)A,并进一步转入大肠杆菌(E.coliDH5a)大量扩增.实验分4组,A组HepG2细胞转染重组质粒,B组HepG2细胞转染不含CD40LcDNA的空质粒,C组HepG2细胞正常培养,D组HepG2细胞加入G418作为转染对照.RT-PCR及流式细胞术鉴定A,B,C3组细胞表面CD40L和CD40的表达后,A,B,C3组细胞分别设6个复孔培养72h后,流式细胞术检测细胞凋亡、细胞周期分布和Fas表达.结果:测序结果显示人CD40L基因真核表达质粒CD40L-pcDNATM3.1/myc-His(-)A构建成功.流式细胞术检测A组HepG2细胞表面CD40L表达为39.7%,CD40表达为15.4%;B和C组细胞表面仅有CD40表达,分别为31.7%和28.5%.A组细胞凋亡率45.0±0.3%,B,C组均未发生明显凋亡(P<0.01).与C组细胞比较,A组细胞周期分布主要阻滞在G1期(90.4±1.3%vs60.6±1.5%,P<0.01),S期(6.32±1.0%vs12.0±0.7%)和G2/M期分布(3.3±0.7%vs27.3±1.2%)均有减少(P<0.01).A组细胞Fas表达率(27.8±1.5%)较B组(3.2±0.8%)和C组(4.2±1.0%)明显上调(P<0.01).结论:我们构建的人CD40L基因真核表达质粒CD40L-pcDNATM3.1/myc-His(-)A可以在人肝癌细胞HepG2中稳定表达,CD40L对于HepG2细胞具有促凋亡的作用,这可能与CD40L-CD40作用后导致HepG2细胞Fas表达上调和细胞周期阻滞有关.     

Survivin启动子驱动Trail诱导肝癌细胞凋亡的实验研究

目的了解Survivin启动子在HepG2肝癌细胞与3T3细胞中诱导Trail蛋白表达能力的差异,并评价其驱动Trail诱导肝癌细胞凋亡的能力。方法以pGL3-surp340质粒为模板,扩增Survivin340启动子,构建重组质粒pcDNA3.1/SurP/Trail。将重组质粒分别转染HepG2肝癌细胞和3T3细胞,通过Western Blot检测两种细胞中Trail蛋白表达的差异。利用流式细胞术检测HepG2肝癌细胞及3T3细胞转染重组质粒pcDNA3.1/SurP/Trail后细胞凋亡的情况。结果成功构建了重组质粒pcDNA3.1/SurP/Trail,转染HepG2和3T3两种细胞后,通过Western Blot检测,HepG2肝癌细胞Trail蛋白表达的相对灰度值为0.49±0.43,较3T3细胞Trail蛋白表达(0.15±0.37)明显增强(P0.05)。利用流式细胞术检测,HepG2肝癌细胞转染重组质粒组的凋亡率(%)为11.59±0.74,空白质粒组为3.45±0.52,未转染组为2.67±0.34;3T3细胞重组质粒组的凋亡率(%)为3.26±0.24,空白质粒组3.16±0.15,未转染组2.83±0.27。HepG2细胞转染重组质粒组凋亡率明显高于其他对照组(P0.05)。结论含Survivin基因启动子的重组质粒pcDNA3.1/SurP/Trail在肿瘤细胞中能增强Trail蛋白的表达,并能诱导HepG2肝癌细胞凋亡。     

乙型肝炎病毒X基因-丙型肝炎病毒C基因共表达对肝癌细胞胰岛素样生长因子-2表达的影响

目的 建立HBV X-HCV C共表达蛋白细胞表达模型,并探讨其对细胞胰岛素样生长因子-2(IGF-2)的影响.方法 双酶切质粒pXT1-X,得到完整的HBV X基因片段后,将其插入到质粒PBK-CMV和PBK-HCV C的相应酶切位点,得到重组质粒PBK-X和PBK-X-C;再将质粒PBK-CMV、PBK-X、PBK-HCV C和PBK-X-C分别导人肝癌细胞株HepG2中,G418筛选,RT-PCR、蛋白印迹鉴定HBV X和HCV C蛋白表达.流式细胞仪、蛋白印迹检测IGF-2蛋白表达.结果 质粒PBK-CMV、PBK-X、PBK-HCV C和PBK-X-C在HepG2细胞中有稳定表达.表达共表达蛋白的细胞的胰岛素样生长因子-2活性较转染空载体的细胞及单独表达HBV X-HCVC蛋白的细胞明显升高.结论 HBV X-HCV C共表达蛋白能显著上调胰岛素样生长因子-2活性,提示HBV、HCV可能具有协同致癌作用.     

HBV X基因转染对HepG2肝癌细胞凋亡的影响及其机制

目的:研究HBV X基因转染对HepG2肝癌细胞凋亡及凋亡相关因子表达的影响.方法:用脂质体转染法将HBx真核表达载体pcDNA3/HBx瞬时转入HepG2细胞,以未转染的HepG2细胞及转染空载体pcDNA3的细胞为对照.RT-PCR法检测HBx基因的表达;MTT法检测各组细胞的增殖活性;TUNEL法检测各组的凋亡情况.β-actin为内参,半定量RT-PCR法检测凋亡相关基因Bax、Bcl-xL、c-myc的表达量变化.结果:pcDNA3-X转染HepG2细胞后,RT-PCR扩增出HBV X片段,空质粒组及正常对照组均未扩增出相应片段.HepG2细胞转染HBx基因后,相对于对照组细胞增殖能力明显下降,凋亡增多,差异有显著性意义(P＜0.01);转染HBx的细胞Bax、Bcl-xL、c-myc mRNA相对表达量较转染空质粒组和未转染质粒组明显增高,差异有显著性意义(P＜0.05).结论:成功将HBx基因转染入HepG2细胞,并在细胞中表达,转染HBx基因可同时上调Bax、Bcl-xL、c-myc mRNA表达,促进HepG2细胞凋亡,抑制增殖.     

HBV X基因-HCV C基因cDNA融合基因真核表达载体的构建及其表达

目的：构建HBV X-HCV C融合基因真核表达载体，并获得稳定表达该基因的HepG2细胞株。方法：双酶切质粒pXT1-X，得到完整的HBV X基因片段后，将其插入到质粒PBK-CMV和PBK-HCVC的相应酶切位点，得到重组质粒PBK-X和PBK-X-C；再将质粒RBK-CMV、PBK-X、PBK-HCV C和PBK-X-C分别导入肝癌细胞株HepG2中，G418筛选，RT-PCR、蛋白印迹鉴定HBV X和HCV C蛋白表达。结果：质粒PBK-CMV、PBK-X、PBK-HCV C和PBK-X-C在HepG2细胞中有稳定表达。结论：成功构建HBV X-HCVC融合基因真核表达载体，并获得稳定表达该基因的HepG2细胞株。     

靶向cyclinE小干扰RNA对肝癌HepG2细胞增殖和凋亡的影响

目的:以cyclinE基因编码区为靶位,构建表达小干扰RNA(siRNA)的质粒载体,观察转染后对HepG2细胞的影响.方法:针对cyclinE基因序列构建表达siRNA的真核表达载体pSilencer3.1-H1hygro,利用脂质体Metafectene转染CyclinE基因高表达的肝癌细胞株HepG2.流式细胞仪检测细胞周期及凋亡率,MTT法检测细胞增殖活性,RT-PCR和Western blot法观察转染后细胞cyclinE基因表达.结果:成功构建了表达siRNA的真核质粒载体,转染后cyclinE基因mRNA及蛋白表达水平分别下降了79%和65%.结论:靶向cyclinE基因的siRNA可有效沉默HepG2细胞高表达的cyclinE基因,从而抑制肝癌细胞的增殖并促进凋亡.     

RNA干扰诱导肝癌HepG2细胞凋亡对丹参酮ⅡA药物敏感性的影响

目的:探讨载体介导的RNA干扰技术诱导HepG2细胞凋亡对丹参酮ⅡA药物敏感性的影响.方法:应用靶向细胞周期E(cyclin E)基因的siRNA真核表达载体转染HepG2细胞诱导凋亡,再以丹参酮ⅡA处理48h(cyclinE siRNA+丹参酮ⅡA组),同时设立cyclin EsiRNA组、无义siRNA组、丹参酮ⅡA组以及空白对照组,流式细胞仪检测细胞周期及凋亡率,吖啶橙荧光染色检测细胞凋亡形态,Western blot法观察细胞Caspase-3蛋白表达.结果:单用cyclinE siRNA质粒转染或丹参酮ⅡA处理肝癌HepG2细胞,细胞凋亡率显著高于空白对照组(P＜0.01),2μg/ml剂量凋亡率分别达到21.6%、23.6%.cyclinE siRNA质粒转染预诱导再经丹参酮ⅡA处理,HepG2细胞G0～G1期比例显著增高,S期、G2～M期细胞所占有比例明显下降;与单用cyclinE siRNA质粒转染、丹参酮ⅡA两组比较,细胞凋亡率分别增高了1.81和1.61倍,比两组合计增高0.35倍,Caspase-3蛋白表达水平分别增高了0.91倍和0.66倍.结论:通过cyclinE siRNA质粒转染诱导的HepG2细胞凋亡可提高丹参酮ⅡA药物敏感性,其机制与增强凋亡控制相关基因表达有关.     

乙型肝炎病毒X基因对肝细胞系细胞凋亡及端粒酶活性的影响

目的探讨乙型肝炎病毒x基因对肝细胞恶性变的作用机制.方法将带C基因、S基因的载体电转染导入HepG2细胞,筛选表达细胞克隆,复苏带X基因的HepG2细胞.PCR-ELISA检测各株细胞的端粒酶活性.用反义寡核苷酸诱导细胞凋亡,流式细胞仪观测转染了x基因、C基因、S基因细胞的凋亡情况.结果表达细胞克隆经同步化处理,39.50%转染X基因的细胞进入细胞S周期,其端粒酶活性指数395±0.07明显高于其它各组细胞.反义寡核苷酸诱导后,转染X基因细胞凋亡峰明显减小,凋亡率仅1.75%;其细胞活性与反义寡核苷酸浓度成反比.结论乙型肝炎病毒X基因上调肝源细胞端粒酶活性,抑制细胞凋亡,这可能是诱导肝细胞恶性变的又一机制.     

人ZEB1基因真核表达载体的构建及其对肝癌细胞株HepG2增殖凋亡的影响

目的：探讨ZEB1基因与肝癌的关系,进一步揭示ZEBl基因在肝癌发生发展过程中的作用。方法：利用基因重组技术构建pCI-neo-ZEB1真核表达载体：脂质体介导转染技术转染肝癌细胞系HepG2。采用WesternBlot技术检测重组质粒的转染效率,CCK8比色法测定重组质粒转染对HepG2细胞体外增殖能力的影响,流式细胞术检测重组质粒转染后HepG2细胞凋亡率。结果：重组质粒经Nhel和Xbal双酶切、测序与ZEBl基因序列一致;利用脂质体介导将pCI-neo-ZEB1重组质粒转染HepG2细胞株,经WesternBlot技术检测ZEB1基因在蛋白水平稳定高表达;与对照组比较,人HepG2细胞株转染pCI-neo-ZEB1真核表达载体后细胞增殖能力增强,细胞凋亡率明显降低。结论：成功构建重组质粒Pci-neo-ZEB1并转入肝癌细胞株HepG2后,细胞增殖能力增强,凋亡减少。     

B protein of factor XIII: differentiation between free B and complexed B

Plasma factor XIII is a complex of A and B proteins noncovalently linked in a tetramer, A2B2, Enzyme-linked immunosorbent assays (ELISA) were developed to measure the separate factor XIII proteins and the complex. All of the A protein in plasma is in the zymogen complex. The B assay measures the total amount of B protein in plasma (both free B and complexed B). This was confirmed by nondenaturing gel electrophoresis and immunoblotting, which showed two bands for B in plasma with this antibody. Two assays were developed to measure A2B2 complex specifically. One assay used a monoclonal antibody to B to bind antigen and measured B protein in the zymogen complex only and hence the concentration of the complex. The specificity of this antibody was also shown by immunoblotting. In the second assay, the capture antibody was to B and the tag antibody was to A. These two assays gave identical results for the concentration of A2B2 (0.07 mumol/L, 21.6 micrograms/mL in normal plasma). Thus, for the first time, differentiation and quantitation of free B and complexed B in plasma was possible. The assays were used to measure factor XIII proteins in plasma from normal controls, homozygous-deficient factor XIII patients, and their heterozygous relatives. The normal concentration of A in plasma is 0.13 to 0.16 mumol/L (approximately 11 micrograms/mL), all of which is in A2B2. The total B concentration is 0.26 to 0.28 mumol/L (approximately 21 micrograms/mL), half of which is complexed. The free B concentration is 0.13 mumol/L (approximately 10 micrograms/mL). Homozygous-deficient patients have essentially no A protein, but their free B concentration is 0.11 mumol/L. Heterozygotes have decreased A2B2, but their free B is 0.11 mumol/L. These results indicate that the concentration of free B is remarkably constant and does not depend on the concentration of A2 or A2B2.     

Subgenotype reclassification of genotype B hepatitis B virus

ABSTRACT: BACKGROUND: Nine subgenotypes from genotype B have been identified for hepatitis B virus (HBV). However, these subgenotypes were less conclusive as they were often designated based on a few representative strains. In addition, subgenotype B6 was designated twice for viruses of different origin. METHODS: All complete genome sequences of genotype B HBV were phylogenetically analyzed. Sequence divergences between different potential subgenotypes were also assessed. RESULTS: Both phylogenetic and sequence divergence analyses supported the designation of subgenotypes B1, B2, B4, and B6 (from Arctic). However, sequence divergences between previously designated B3, B5, B7, B8, B9 and another B6 (from China) were mostly less than 4%. In addition, subgenotype B3 did not form a monophyly. CONCLUSION: Current evidence failed to classify original B5, B7, B8, B9, and B6 (from China) as subgenotypes. Instead, they could be considered as a quasi-subgenotype B3 of Southeast Asian and Chinese origin. In addition, previously designated B6 (from Arctic) should be renamed as B5 for continuous numbering. This novel classification is well supported by both the phylogeny and sequence divergence of > 4%.     

Prevalence of hepatitis B virus genotype B in Vietnamese patients with chronic hepatitis B

Purpose  Hepatitis B virus (HBV) genotypes can affect treatment response to interferon-based therapy and disease outcomes in patients with chronic hepatitis B (CHB). Little data exist to characterize HBV genotypes in Vietnamese, one of the largest minority groups in the United States and also one with one of the highest CHB and liver cancer disease burdens. The goal of this study was to compare the distribution of HBV genotypes in Vietnamese and Chinese patients. Methods  We performed a cross-sectional study of 567 consecutive patients of Vietnamese (n = 478) or Chinese (n = 89) descent, with HBV genotype mutation analysis performed between 7/2,005 and 6/2,008 at a community gastroenterology clinic and a university-affiliated liver clinic in the United States. Results  There were no significant differences between the Vietnamese and Chinese groups in mean age (45 and 44 years), gender (58% and 61% male), HBeAg status (64% and 65% negative), median alanine aminotransferase (33 and 41 U/L), and log₁₀ HBV DNA (4.9 and 5.0 log₁₀ IU/ml), or the prevalence of precore/basic core promoter mutations (72% and 71%), respectively. Vietnamese patients had a much higher prevalence of HBV genotype B and a lower prevalence of genotype C than Chinese patients: 74% and 25% vs. 55% and 43% (P = 0.001). Conclusions  Chinese patients with CHB often carry either B or C genotype. Vietnamese patients with CHB mostly have HBV genotype B. Additional studies are needed to further characterize the clinical significance of HBV genotype in the natural history and treatment outcomes of CHB in Vietnamese patients.     

乙型肝炎病毒B基因型亚型的检测

目的:建立乙型肝炎病毒(hepatitis B virus,HBV)B基因型亚型的检测方法,并对其进行临床研究.方法:根据GenBank中20株Ba亚型,10株Bi亚型以及25株C型全长基因组序列设计Ba、Bj亚型特异探针以及巢式PCR引物.采用反向杂交技术将B亚型特异探针固定在芯片上,通过与地高辛标记的扩增产物杂交检测B型HBV亚型.对镇江地区200例B基因型HBV血清样本进行亚型分析并对患者HBVDNA YMDD变异进行检测.通过对部分血清中的HBV DNA进行序列分析验证该方法的准确性.结果:200例B基因型HBV患者中,Ba亚型184例(92%),Bj亚型16例(8%).在持续使用拉米呋啶的80例患者中,Bj亚型6(0%)例,均无YMDD变异,Ba亚型74例,YMDD变异21(28.4%)例.结论:镇江地区B基因型HBV以Ba亚型为主.Ba、Bj亚型在服用拉米呋啶1年后发生YMDD变异的几率并无统计学上的显著差异.     

B safe, B sorted: results of a hepatitis B vaccination outreach programme

The risk of hepatitis B among men having sex with men (MSM) is high, with core antibody rates ranging from 5% to 81%. We describe an outreach, hepatitis B vaccination programme aiming to raise awareness of hepatitis B and increase vaccination uptake. The 13-week programme used an ultra rapid vaccination schedule. Follow-up was defined as complete if the client was core antibody positive, had adequate surface antibody levels following prior vaccination or received three vaccine doses. One hundred and fifty clients were screened for hepatitis B and syphilis. Three cases of untreated syphilis (early latent) and one case of e-antigen-positive hepatitis B were detected. With the aid of text-message reminders, a vaccination completion rate of 76.6% was achieved, with 82.5% completing follow-up. In conclusion, this programme succeeded in reaching MSM not routinely accessing services. Text messaging was an acceptable and effective method of follow-up, resulting in high vaccination completion rates.     

To B or not to B

Recent data from mouse models suggest that some phenotypes of X-linked lymphoproliferative disease (XLP) result from impaired T:B-cell interactions.Hislop and colleagues now provide evidence that this may contribute to abnormal responses to Epstein-Barr virus (EBV) in XLP.     

Hepatitis B Antigen and Prevention of Post-Transfusion Hepatitis B

Abstract. Screening for hepatitis B antigen (HB_sAg) in the serum of blood donors and exclusion of antigen-positive blood units have reduced the frequency of post-transfusion hepatitis but several cases of hepatitis B still occur in association with transfusions. One explanation for this is probably that HB_sAg is not an indicator of infectivity. Thus healthy carriers of the antigen seem to have low infectivity while carriers with chronic liver disease as well as donors incubating hepatitis B probably present a great risk.     

Group B streptococcal polyarthritis complicating hemophilia B

We report a case of polyarticular group B streptococcal infection in an HIV-negative 46-year-old alcoholic with factor IX deficiency. Septic arthritis occurs infrequently in the hemophilic population despite their chronic joint disease; indications for diagnostic arthrocentesis in these individuals are discussed. The group B streptococcus often behaves as an opportunist in adults.