转化生长因子-β1在人和小鼠口腔鳞癌组织中的表达比较

［摘要］　目的　检测转化生长因子-β1（TGF-β1）在人和小鼠正常口腔黏膜、异常增生及鳞癌组织中的表达情况,探讨其在口腔癌发生与发展中的意义。方法　采用免疫组织化学技术,分别检测人和小鼠正常口腔黏膜、中重度异常增生、高分化鳞癌组织各12例中TGF-β1的表达情况,并对人和小鼠各型组织中TGF-β1的表达进行分析。结果　正常口腔黏膜组中人和小鼠TGF-β1表达率分别为33.3%（4/12）和41.7%（5/12）;口腔异常增生组中人和小鼠TGF-β1表达率分别为50.0%（6/12）和58.3%（7/12）;口腔鳞癌组中人和小鼠TGF-β1表达率均为75.0%（9/12）。结论　随着组织恶性程度的升高,人和小鼠各型组织中TGF-β1的阳性表达率逐渐增加,表达部位与强度具有相似性,表明TGF-β1是参与肿瘤发生与发展过程中的一个重要因子,并且人与小鼠口腔癌的发展过程具有相似性。     

小鼠口腔癌不同时期淋巴结和骨髓的VEGF表达情况及其微环境对淋巴道转移的影响

目的 探讨小鼠口腔癌不同时期淋巴结和骨髓的血管内皮生长因子(VEGF)表达情况,及其微环境对口腔癌淋巴道转移的影响.方法 选入40只6周龄雄性健康Balb/c小鼠,将其随机分为A、B、C、D、E组,每组8只.采用4-硝基喹啉-1-氧化物(4-NQO)饮水法构建小鼠口腔癌淋巴道转移模型.其中A组为正常小鼠;B组小鼠舌部黏...     

人肝细胞癌c-myc基因扩增、MTS1/p16基因变异和HBV感染的研究

]目的探讨原癌基因c-myc扩增、抑癌基因MTS1/p16变异以及HBV感染在人肝细胞癌(HCC)发生发展中的作用.方法应用差异PCR结合非变性聚丙烯酰胺凝胶电泳银染及激光扫描(d-PCR-PAGE-Laser)技术检测c-myc基因扩增,应用PCR结合单链构象多态(SSCP)银染法分析MTS1/p16基因变异,PCR检测HBVDNA.结果(1)29例配对肝细胞癌、癌旁组织中c-myc基因扩增阳性率分别为44.83%(13/29)和51.72%(15/29),两者差异无显著性,P＞0.05;但两者均显著高于肝硬化组织c-myc基因扩增的阳性率8.33%(1/12),P＜0.05.(2)只有3例(10.34%,3/29)肝细胞癌中发现MTS1/p16基因纯合性缺失,未发现MTS1/p16基因突变.(3)正常肝脏、肝硬化和肝细胞癌组织中HBVDNA的阳性率分别为14.29%(2/14)、66.67%(8/12)和96.55%(28/29),三者间差异具有高度显著性,P＜0.001,并且HBVDNA的阳性率随肝脏病情的加重而增高(b＝0.3986,P＜0.001).(4)29例肝细胞癌中c-myc基因扩增和HBVDNA存在与否无关(P＜0.01).结论(1)c-myc基因扩增和HBV感染与HCC的发生、发展密切相关,HCC中c-myc基因扩增和HBV感染之间无内在相关性.(2)HCC中MTS1/p16基因纯合性缺失和突变的发生频率较低.[     

基质细胞衍生因子1对骨髓单个核细胞向肝脏迁移分化的影响

目的 探索基质细胞衍生因子1对骨髓单个核细胞向肝脏迁移、分化的影响。方法建立小鼠CCl4-AAF肝损伤模型，从小鼠骨髓中分离出骨髓单个核细胞，以荧光染料PKH26标记后经尾静脉输入肝损伤模型的小鼠体内，实验组立即给予肝内注射基质细胞衍生因子1，对照组给予肝内注射盐水，12d后取肝组织，在荧光显微镜下观察两组骨髓单个核细胞向肝脏迁移的差异，并用免疫组化法测定移植细胞的白蛋白表达。结果 PKH26标记阳性的细胞20倍镜下实验组中每张切片平均迁移数为（195．40±9．095）个，对照组平均迁移数为（169．80±7.983）个（P〈0．05）。免疫组化显示移植细胞可以表达白蛋白。结论 基质细胞衍生因子1可以促进骨髓单个核细胞向肝脏迁移，并且迁移至肝脏的骨髓单个核细胞可以向肝细胞分化。     

Mac-1基因缺失抑制小鼠黑色素瘤肺转移的机制

目的探讨Mac-1基因缺失对黑色素瘤肺转移的抑制作用。方法 Mac-1基因敲除(Mac-1-/-)小鼠配种扩群以获得实验需要的数量,取指数生长期B16细胞,分别尾静脉注射到对照组C57BL/6J小鼠和实验组Mac-1-/-小鼠体内,统计小鼠生存率及肿瘤肺转移结节数,并通过H&E观察肺组织中微转移灶。结果通过配种扩群获得了大量实验用纯合子Mac-1基因敲除小鼠(Mac-1-/-)。与对照组相比,Mac-1缺失后尾静脉注射B16细胞的小鼠存活率显著提高(P<0.001);并且大体观察Mac-1缺失后小鼠肿瘤转移肺结节数目显著减少(P<0.001),抑制率达到75%;进一步通过对肺组织包埋、切片和H&E观察发现,Mac-1缺失后小鼠肺组织中肿瘤微转移灶显著减少(P<0.001)。结论 Mac-1基因缺失能显著抑制小鼠黑色素瘤的肺转移。     

脂多糖动员骨髓CD11b+Gr-1+髓系抑制细胞及其吞噬氧化型低密度脂蛋白形成泡沫细胞

目的 研究小鼠骨髓来源的未成熟CD11b+ Gr-1+髓系前体细胞在急性炎性脂多糖刺激下动员释放.及其诱导分化成巨噬细胞样细胞后吞噬氧化型低密度脂蛋白形成泡沫细胞.方法 小鼠腹腔注射脂多糖5μg/g体重,24 h后采用流式细胞术分析骨髓,脾脏,和外周血中CD11b+Gr-1+髓系前体细胞,CD11b+Gr-1-单核细胞,和CD11b-Gr-1+粒细胞的百分比的变化.体外泡沫细胞形成实验取小鼠骨髓单个核细胞以DMEM培养基+胎牛血清培养,以粒细胞一巨噬细胞集落刺激因子诱导分化48 h,加入100 mg/L氧化型低密度脂蛋白孵育48 h以形成脂质负荷泡沫细胞.油红O染色鉴定泡沫细胞.结果 (1)脂多糖腹腔注射可以显著促进CD11b+Gr-1+髓系前体细胞从骨髓动员并释放到外周组织;脾脏和循环中CD11b+Gr-1+髓系前体细胞和CD11b+Gr-1-单核细胞显著增加.(2)从骨髓分离的CD11b+Gr-1+髓系前体细胞以粒细胞一巨噬细胞集落刺激因子诱导分化后形成单核/巨噬细胞样细胞,继而加入氧化型低密度脂蛋白孵育,可以形成脂质负荷细胞(泡沫细胞).油红O染色可见泡沫细胞的胞浆中有红染的大型脂滴,核被胞浆内脂滴挤压在一侧.结论 急性炎性刺激脂多糖可以动员小鼠骨髓CD11b+Gr-1+髓系前体细胞的向循环和外周组织释放.CD11b+Gr-1+髓系前体细胞可被诱导分化并吞噬氧化型低密度脂蛋白形成泡沫细胞.     

肺间质纤维化小鼠肺内T细胞γ-干扰素和转化生长因子β1的表达

目的 探讨肺组织内T细胞及其转化生长因子β1(TGF-β1)/γ-干扰素(IFN-γ)表达与肺间质纤维化的关系.方法 C57BL/6小鼠30只,随机分为5组,即正常对照组和博莱霉素1、2、3、4周组.采用气管内注射博莱霉素(5 mg/kg)建立纤维化模型,分别于造模后1、2、3、4周断头处死,留取各组小鼠肺组织,观察肺泡炎和肺纤维化程度,流式细胞仪在单个细胞水平检测CD4+、CD8+、CD3+/CD8-/IFN-γ+和CD3+/CD8-/TGF-β1+细胞的频率.结果 博莱霉素组小鼠出现明显纤维化;与正常对照组相比,博莱霉素组肺组织CD4+明显增多,CD8+显著降低(P值均<0.01);博莱霉素组肺组织CD4+T细胞来源IFN-γ水平低于正常对照组,而CD4+T细胞来源TGF-β1水平显著增高于正常对照组(P值均<0.01);CD4+TGF-β1+/CD4+IFN-γ+比值进行性增高,与肺纤维化评分呈正相关(r=0.683,P<0.01).结论 CD4+T细胞来源IFN-γ与TGF-β1分别下调与上调,参与肺纤维化.     

基于单细胞测序发现心脏再灌注损伤中存在一群Fabp5+巨噬细胞新亚群

目的:应用单细胞测序技术,揭示小鼠心脏在缺血再灌注后浸润的巨噬细胞中存在新亚群。方法:选取C57小鼠10只以及绿色荧光蛋白(GFP)基因小鼠,通过伽马射线对C57小鼠进行照射后构建移植有GFP阳性骨髓的小鼠;选用骨髓移植成功的小鼠通过冠脉前降支结扎30 min后再恢复灌注构建心脏缺血再灌注(I/R)模型;于术后3 d处死小鼠并收集新鲜心脏组织,采用美天旎心脏组织消化试剂盒获得细胞悬液,实验分为对照组:单纯利用经典流式细胞分选技术分析I/R 3 d时心脏中的骨髓源性巨噬细胞;实验组:在流式分选的基础上通过新方法C1微流控技术进行单细胞捕获以及转录组学测序。结果:首先通过流式分选技术我们发现心脏中存在两群巨噬细胞:大量骨髓源性的巨噬细胞(CCR2+GFP+,约占80%),以及CCR2-的原位巨噬细胞(约占20%);进一步捕获单个的CCR2+GFP+细胞并构建单细胞的cDNA文库;结合测序数据饱和度以及内部对照spike-in RNA对数据进行筛选得到47个细胞的数据;经过分析发现存在两个细胞亚群,其中一群巨噬细胞高表达Fabp5。结论:通过单细胞测序发现心脏缺血再灌注过程中存在一群新的Fabp5阳性的骨髓来源的巨噬细胞亚群。     

LFA-1基因缺失对小鼠Nave T细胞体外向Th17细胞分化的影响

背景:淋巴细胞功能相关抗原-1(LFA-1)参与T细胞的活化和功能调节,与炎症性肠病的发病密切相关。目的:观察LFA-1基因缺失(LFA-1-/-)对小鼠Nave T细胞体外向Th17细胞分化的影响。方法:繁殖LFA-1-/-子代小鼠,提取鼠尾DNA,PCR法鉴定基因型。LFA-1-/-子代小鼠为实验组,野生型(WT)C57BL/6J小鼠为对照组,磁珠分选脾脏单个核细胞中的CD4+CD62L+Nave T细胞并检测其纯度。体外建立不同Th17细胞诱导分化体系[转化生长因子-β(TGF-β)、TGF-β+白细胞介素-6(IL-6)和TGF-β+IL-6+IL-23],以流式细胞术检测两组分选得到的Nave T细胞在不同体系中诱导出的Th17细胞比率,荧光定量PCR法和ELISA法检测Th17细胞特异性转录因子ROR-γt和特异性标记物IL-17A表达。结果:15只子代小鼠均为LFA-1-/-小鼠,磁珠分选得到的CD4+CD62L+Nave T细胞纯度大于95%。低剂量TGF-β+IL-6即能诱导出Th17细胞,在此基础上加入IL-23能促进更多Th17细胞产生。与WT对照组相比,LFA-1-/-组Nave T细胞在TGF-β+IL-6+IL-23体系中诱导产生Th17细胞的效应更为明显(17.2%±1.4%对5.7%±0.2%,P0.001),ROR-γt、IL-17A mRNA表达上调(P0.001),细胞培养上清液中IL-17A浓度升高(P0.01)。结论:LFA-1基因缺失能促进小鼠Nave T细胞体外向Th17细胞分化。     

癌胚抗原相关黏附分子1对CVB3感染后CAR表达及心肌损伤的影响

目的探讨癌胚抗原相关黏附分子1(CEACAM1或CC1)对柯萨奇病毒(CVB3)感染后柯萨奇病毒-腺病毒受体(CAR)表达和继发心肌损伤的影响。方法构建过表达小鼠CC1重组病毒,包装重组慢病毒pLVX-CEACAM 1-ZsGreen-Puro(rLV-CEACAM 1)并测定慢病毒生物学滴度。分为CC1正常组、CC1过表达组、CC1正常+CVB3组和CC1过表达+CVB3组;各组使用AnnxinV-PE/7-AAD双染法检测心肌细胞凋亡率,CCK8检测细胞活性;qPCR检测CAR基因表达;Western blot检测CAR蛋白表达,ELISA检测肿瘤坏死因子α(TNF-α)及白细胞介素1β(IL-1β)水平。结果 (1)CEACAM1重组载体测序提示目的基因序列连接,证明小鼠CEACAM1重组病毒载体构建成功,测定重组慢病毒滴度为1.5×10~(11) TU/L。(2)CC1过表达+CVB3组较其他组心肌细胞凋亡率明显升高,心肌细胞增殖最低(P0.05)。(3)CAR基因相对表达量在CC1过表达+CVB3组最高,而在CC1正常组最低,CAR蛋白表达也有类似结果;CC1过表达组较CC1正常组胞内CVB3相对表达量显著升高(P0.05)。(4)CC1过表达组TNF-α、IL-1β水平较高,CVB3感染后较前明显升高。结论 CC1可能可以促进CVB3感染心肌细胞后心肌组织或细胞上CAR的表达,CAR可能是CC1调控CVB3感染心肌致心肌损伤过程的潜在作用靶点。     

1-Naphthyl isocyanate and 1-naphthylamine as metabolites of 1-naphthylisothiocyanate

Abstract: The importance of the bioactivation of 1-naphthylisothiocyanate was studied. Forty minutes after 1-naphthylisothiocyanate administration to rats, bile was collected over a 2.5-h period; the liver was then excised and homogenized. 1-naphthylisothiocyanate and its metabolites in bile and liver of rats were identified and quantified using coupled gas chromatography-mass spectrometry. Three main compounds were found in all 1-naphthylisothiocyanate-treated animals. They were identified as 1-naphthyl isocyanate, 1-naphthylamine and the parent compound, 1-naphthylisothiocyanate. When rats were given cycloheximide, which attenuates 1-naphthylisothiocyanate toxicity, 30 min before 1-naphthylisothiocyanate (300 mg/kg), 1-naphthyl isocyanate concentration was significantly lower than in rats receiving only 1-naphthylisothiocyanate. The appearance of 1-naphthylamine was also inhibited by cycloheximide, although not to the same extent as 1-naphthyl isocyanate. On the other hand, phenobarbital, which potentiates 1-naphthylisothiocyanate hepatotoxicity, enhanced 1-naphthyl isocyanate and 1-naphthylamine formation. It is suggested that 1-naphthyl isocyanate, 1-naphthylamine and the highly reactive sulfur released from 1-naphthylisothiocyanate might be involved in the hepatotoxic effect of 1-naphthylisothiocyanate.     

The target of ezetimibe is Niemann-Pick C1-Like 1 (NPC1L1)

Ezetimibe is a potent inhibitor of cholesterol absorption that has been approved for the treatment of hypercholesterolemia, but its molecular target has been elusive. Using a genetic approach, we recently identified Niemann-Pick C1-Like 1 (NPC1L1) as a critical mediator of cholesterol absorption and an essential component of the ezetimibe-sensitive pathway. To determine whether NPC1L1 is the direct molecular target of ezetimibe, we have developed a binding assay and shown that labeled ezetimibe glucuronide binds specifically to a single site in brush border membranes and to human embryonic kidney 293 cells expressing NPC1L1. Moreover, the binding affinities of ezetimibe and several key analogs to recombinant NPC1L1 are virtually identical to those observed for native enterocyte membranes. KD values of ezetimibe glucuronide for mouse, rat, rhesus monkey, and human NPC1L1 are 12,000, 540, 40, and 220 nM, respectively. Last, ezetimibe no longer binds to membranes from NPC1L1 knockout mice. These results unequivocally establish NPC1L1 as the direct target of ezetimibe and should facilitate efforts to identify the molecular mechanism of cholesterol transport.     

Inhibition of procarcinogen-bioactivating human CYP1A1, CYP1A2 and CYP1B1 enzymes by melatonin

Abstract:  Administration of melatonin to rodents decreases the incidence of tumorigenesis initiated by benzo[ a ]pyrene or 7,12-dimethylbenz[ a ]anthracene, which requires bioactivation by cytochrome P450 enzymes, such as CYP1A1, CYP1A2 and CYP1B1, to produce carcinogenic metabolites. The present study tested the hypothesis that melatonin is a modulator of human CYP1 catalytic activity and gene expression. As a comparison, we also investigated the effect of melatonin on the catalytic activity of CYP2A6, which is also a procarcinogen-bioactivating enzyme. Melatonin (3–300 μ m ) decreased 7-ethoxyresorufin O -dealkylation catalyzed by human hepatic microsomes and recombinant CYP1A1, CYP1A2 and CYP1B1, whereas it did not affect coumarin 7-hydroxylation catalyzed by hepatic microsomes or recombinant CYP2A6. Melatonin inhibited CYP1 enzymes by mixed inhibition, with apparent K _i values (mean ± S.E.M.) of 59 ± 1 (CYP1A1), 12 ± 1 (CYP1A2), 14 ± 2 (CYP1B1) and 46 ± 8 μ m (hepatic microsomes). Additional experiments indicated that melatonin decreased benzo[ a ]pyrene hydroxylation catalyzed by hepatic microsomes and CYP1A2 but not by CYP1A1 or CYP1B1. Treatment of MCF-10A human mammary epithelial cells with melatonin (up to 300 μ m ) did not affect basal or benzo[ a ]pyrene-inducible CYP1A1 or CYP1B1 gene expression. Consistent with this finding, melatonin did not influence reporter activity in aryl hydrocarbon receptor-dependent pGudluc6.1-transfected MCF-10A cells treated with or without benzo[ a ]pyrene, as assessed in an in vitro cell-based luciferase reporter gene assay. Overall, melatonin is an in vitro inhibitor of human CYP1 catalytic activity, and it may be useful to develop potent analogues of melatonin as potential cancer chemopreventive agents that block CYP1-mediated chemical carcinogenesis.     

甲型H1N1与季节性H1N1流感病毒血凝素基因比较分析

目的分析泰安市2008～2009年度季节性流感与2009年度甲型H1N1流感病原学检测结果 ,比较季节性H1N1与甲型H1N1血凝素基因变异情况。方法选择国家级流感监测哨点医院以及暴发疫情的疫点,采集流感样病例的鼻咽拭子标本,通过RealtimePCR进行病毒检测,用MDCK细胞进行病毒分离,通过RT-PCR扩增血凝素HA1片段的基因并测序,利用生物信息学进行序列分析。结果 2008～2009年共检测鼻咽拭子标本283份,分离出流感病毒33株,分离阳性率为11.67%,其中季节性H1N1亚型31株。2009年5月1日～12月31日,检测鼻咽拭子标本996份,流感核酸检测阳性417份,阳性率为41.86%,其中甲型H1N1337份,季节性H1N1亚型1份。6株季节性H1N1病毒均在多个氨基酸位点上发生变异,与疫苗株A/Brisbane/59/2007(H1N1)比较,有11个位点发生了突变,其中5个位点位于抗原决定簇上;测序成功的6株甲型H1N1病毒在多个氨基酸位点发生变异,与疫苗株A/California/07/2009(H1N1)比较,有6个位点发生突变,其中1个位点位于抗原决定簇的B区。结论 2008～2009年度季节性H1N1为优势株,甲流暴发后,甲型H1N1成为绝对优势毒株。季节性H1N1分离株有多处氨基酸替换,抗原决定簇B区变异频繁;甲型H1N1病毒分离株的基因有变异,但关键位点第222位仍为D(天冬氨酸),与疫苗株相比抗原决定簇的关键位点变化不大。     

Characterization of MTHFR,GSTM1, GSTT1, GSTP1, and CYP1A1 genotypes in childhood acute leukemia

The role of methylenetetrahydrofolate reductase (MTHFR C677T), glutathione S-transferases (GSTM1 and GSTT1 null, GSTP1 Ile105Val), and cytochromes p450 (CYP1A1*2A) genotypes in the etiology of childhood leukemia was simultaneously investigated. 144 Turkish children with acute lymphoblastic leukemia (ALL) and 33 with acute nonlymphoblastic leukemia (ANLL) were studied and compared with 185 healthy pediatric controls. The frequency of MTHFR genotype was insignificantly higher in ALL (7.7%) and ANLL (6.3%) than in controls (4.4%). Equal distribution of the GSTM1 null genotype was detected between ALL patients and controls (55%), while its incidence was slightly higher in ANLL patients (61.3%). Although GSTT1 null genotype was insignificantly lower in ALL patients (20.9%) than controls (22.7%), it was significantly underrepresented in ANLL patients (6.5%) (P = 0.05, OR 0.24, 95% CI 0.05-1.03). The homozygous frequency of GSTP1 genotype did not differ significantly between groups of ALL (3.7%), ANLL patients (9.1%) and controls (4.9%). Homozygous CYP1A1*2A genotype was underrepresented in ALL patients (1%) as compared to control (4.8%) but the differences did not reach to statistical significance (OR 0.21; 95% CI 0.03-1.72). Homozygosity for this genotype was not detected in ANLL patients. No particular association was noted between different combinations of combined genotypes and risk of development of childhood ALL and ANLL. These results suggested that there are no significant associations between the studied genotypes and the risk of developing either form of acute leukemia except GSTT1 null and homozygosity for CYP1A1 genotypes that may play protective roles in the development of ANLL in Turkish children.