脑出血灶周组织Bax、Bcl-2的表达与神经元凋亡关系的实验研究

目的检测脑出血灶周组织Bax、Bcl-2的表达,探讨与神经元凋亡的关系。方法对健康家犬30只在DSA介入下刺破大脑中动脉制作脑出血模型,选择出血后6h、12h、24h、48h、72h及96h共6个时间点,每点5只,均于相应时间点处死后取脑,检测出血灶周Bax、Bcl-2及神经元凋亡的表达。结果Bax及神经元凋亡的表达均于48h达高峰,至96h皆明显下降(与48h比较,P<0.01);Bcl-2出血后72h达高峰,至96h末见明显下降(与72h比较,P>0.05);Bax的表达与神经元凋亡呈正相关(P<0.05);Bcl-2与神经元凋亡的表达出血后48h前均呈正相关(P<0.05),48h后均呈负相关倾向,但无统计学差异(P>0.05)。结论Bax及Bcl-2参与了ICH后出血灶周神经元凋亡的过程,前者诱导和加重了神经元凋亡,后者有抑制凋亡作用,但显示其强度不足。     

阿苯达唑对人结肠癌SW480细胞增殖、凋亡及Bcl-2表达的影响

目的观察阿苯达唑(Albendazole,ABZ)对人结肠癌SW480细胞增殖、凋亡及其对Bcl-2表达的影响,并探讨其作用机制。方法用不同终浓度的ABZ(0.5、1.0、2.0及4.0 mg/ml)处理SW480细胞24、48、72 h,设对照组(ABZ浓度为0 mg/ml),CCK-8法检测ABZ对SW480细胞增殖活力的影响,并计算增殖抑制率及IC50。用不同终浓度的ABZ(1.0、2.0 mg/ml)处理SW480细胞,设对照组(ABZ浓度为0 mg/ml),流式细胞术检测细胞凋亡率,RT-PCR及Western blot检测Bcl-2 mRNA及蛋白的表达。结果与对照组比较,0.5、1.0、2.0及4.0 mg/ml ABZ处理组A值均明显降低(P﹤0.05),随着作用浓度的增加及作用时间的延长,抑制作用逐渐增强,且呈时间-剂量依赖性,2.0 mg/ml ABZ处理组24、48、72 h的IC50值分别为3.18、1.96和1.03 mg/ml;与对照组比较,1.0、2.0 mg/mlABZ处理组细胞凋亡率均明显增加(P﹤0.05),Bcl-2 mRNA及蛋白的表达均明显降低(P﹤0.05)。结论 ABZ能抑制结肠癌SW480细胞的增殖,并显著促进细胞凋亡,其作用机制可能与下调Bcl-2表达有关。     

环磷酰胺暴露后Piwil2在人神经母细胞瘤移植瘤中的表达

目的探讨环磷酰胺(cyclophosphamide,CP)暴露后Piwil2在人神经母细胞瘤(neuroblastoma,NB)移植瘤中的表达。方法建立免疫活性C57BL/6j系小鼠的人NB SK-N-SH细胞株荷瘤模型,选择瘤体积在100~200 mm3之间的20只荷瘤小鼠,随机分为生理盐水对照组(NS组)和环磷酰胺组(CP组),每组10只,CP组每日经腹腔注射CP75 mg/kg,2次/周,连续2周;NS组每日经腹腔注射NS 2 ml。每2天测量肿瘤体积,计算相对肿瘤体积(RTV);停药后次日处死小鼠,称瘤重,计算抑瘤率(IR);并采用RT-PCR法检测各组移植瘤组织中Piwil2基因m RNA的转录水平,免疫组化法和Western blot法检测各组移植瘤组织中Piwil2蛋白的分布及表达水平。结果与NS组比较,CP组移植瘤的RTV和瘤重均显著降低(P0.05),CP组的平均抑瘤率为83.56%。两组移植瘤组织中Piwil2基因m RNA的转录水平差异无统计学意义(P0.05)。NS组移植瘤组织中Piwil2蛋白高表达于胞浆,而CP组大部分肿瘤细胞坏死,Piwil2蛋白表达下降,细胞核稀疏,核浓缩,细胞体积变小;CP组移植瘤组织中Piwil2蛋白的表达水平明显低于NS组(P0.05)。结论 CP干预后,移植瘤缩小,移植瘤组织中Piwil2基因m RNA的转录水平不变,但蛋白表达水平有改变,可能影响人NB抵抗性。     

邻苯二甲酸二(2-乙基)己酯诱导隐睾对SD幼鼠睾丸生殖细胞凋亡的影响

目的探讨环境内分泌干扰物邻苯二甲酸二(2-乙基)己酯[D(i2-ethylhexy1)phthalate,DEHP]作用于SD孕鼠后,对哺乳期雄性幼鼠睾丸组织中生殖细胞凋亡及凋亡基因Bax和Bcl-2表达的影响。方法将30只妊娠第12.5天的SD孕鼠随机分正常对照组、玉米油对照组和DEHP诱导隐睾组,每组10只。玉米油对照组和DEHP诱导隐睾组自妊娠第12.5～19.5天分别每日灌胃玉米油(2 ml)和DEHP(500 mg/kg),正常对照组不给药。取各组出生后第20天的雄性幼鼠睾丸组织,采用Q-PCR法检测睾丸组织中Bax和Bcl-2基因的水平,流式细胞术检测睾丸生殖细胞的凋亡情况。结果 DEHP诱导隐睾组幼鼠睾丸组织中Bax基因mRNA的水平显著高于两对照组(P<0.000 1),Bcl-2基因mRNA的水平显著低于两对照组(P<0.01);DEHP诱导隐睾组幼鼠睾丸生殖细胞凋亡百分率显著高于两对照组(P<0.000 1)。结论孕期暴露环境内分泌干扰物DEHP可引起雄性子代发生隐睾,且隐睾鼠睾丸生殖细胞凋亡率增加,隐睾子代睾丸组织中凋亡基因Bax和Bcl-2的表达有改变,推测其改变可能参与了生殖细胞的凋亡过程,并可能与隐睾继发的远期不育有关。     

Caspase-3、Bcl-2和Bak在胃癌中的表达及意义

目的 研究Caspase-3,Be1-2.Bak等凋亡相关基因蛋白在胃癌中的表达与胃癌临床病理特征和预后的相关性.方法 将100例无术前放化疗史的胃癌手术标本和30例对照组胃粘膜制成组织芯片,取样针直径2.0 mm.用免疫组化方法分别检测Caspase-3.Bel-2,Bak的表达;用原位末端标记法进行细胞凋亡指数捡测.对随访14个月至13年的47例作生存分析.结果 获得2个组织芯片蜡块,分别含114和1164个位点.Caspase-3在正常粘膜的表达(90%)显著高于胃癌组织(56%)(P＜0.01),其表述与胃癌组织学分化.血管神经侵犯相关(P＜0.05),与淋巴结转移和国际抗癌联盟(UICC)临床分期及预后无关.Bl-2和Bak在胃癌中的表达分别为42%和47%,表达均与组织学分化相关(P＜0.05),与淋巴结转移、血管神经侵犯、UICC分期及预后无关.结论 Caspase-3.Bcl-2和Bak均参与细胞凋亡调控和胃癌生物学进程,但其表达与胃癌预后无关.UICC分期仍然是胃癌的独立预后指标.     

GINS2基因siRNA真核表达质粒的构建及其对NB4细胞凋亡的影响

目的构建GINS2基因siRNA真核表达质粒,并检测其对NB4细胞凋亡的影响。方法人工合成针对GINS2基因的4组siRNA干扰序列和1组无同源性的序列,测序鉴定后转染低传代人早幼粒细胞系NB4细胞,经G418筛选后,通过QRT-PCR、Western blot检测重组质粒对NB4细胞中GINS2基因mRNA转录水平和蛋白表达水平的影响;流式细胞术检测NB4细胞的凋亡情况。结果 5组重组质粒经测序证明构建正确,4组干扰质粒转染NB4细胞后,细胞中GINS2基因mRNA的转录水平和蛋白的表达水平均有所降低,其中干扰组1基因干扰率达50%,蛋白相对表达量为56%;干扰组1细胞凋亡率为32.54%,较正常对照组和NC组明显上升(P<0.01)。结论成功构建了GINS2基因siRNA真核表达质粒,抑制GINS2基因的表达可促进NB4细胞的凋亡,为进一步研究GINS2基因在白血病中的作用奠定了基础。     

神经干细胞对去血清诱导PC12细胞凋亡的作用

肾上腺嗜铬细胞瘤细胞(PC12 cells)去血清后,其凋亡与多巴胺能神经元的凋亡有许多共同之处,今通过研究神经干细胞(NSCs)对去血清诱导的PC12细胞凋亡的作用,进一步为NSCs移植治疗神经系统疾病提供相应的实验和理论依据.将正常培养的PC12细胞与NSCs以不同的方式进行去血清共培养,观察PC12细胞的形态,检测PC12细胞的活性,计算PC12细胞的存活率,同时检测培养基中胶质细胞源神经营养因子(GDNF)的浓度,分析不同培养方式下NSCs对去血清诱导凋亡的PC12细胞的作用以及NSCs与去血清诱导凋亡的PC12细胞共培养后,其分泌GDNF的能力.结果表明:①去血清诱导PC12细胞凋亡呈时间依赖性,去血清72 h后,PC12细胞存活的比率为44.25%;②NSCs培养基对去血清诱导凋亡的PC12细胞没有明显的保护作用;③NSCs培养上清及NSCs对去血清诱导凋亡的PC12细胞具有保护作用;④NSCs与去血清诱导凋亡的PC12细胞共培养后,分泌GDNF的能力增强.     

RNA干扰Apg-2基因表达对BaF3-MIGR1和BaF3-p210细胞凋亡的影响

目的探讨RNA干扰Apg-2基因表达对BaF3-MIGR1和BaF3-p210(Bp210)细胞凋亡的影响。方法取BaF3-MIGR1和Bp210、稳定抑制Apg-2表达的BaF3-MIGR1-Hspa42和Bp210-Hspa42细胞及阴性对照Bp210-HspaHK和BaF3-MIGR1-HspaHK细胞,采用瑞特染色法观察各组细胞的形态学变化;流式细胞术检测各组细胞的凋亡情况;Western blot法检测各组细胞中凋亡相关蛋白Bax和Bcl-2的表达水平。结果干扰Apg-2基因表达后,细胞出现肿胀、胞浆空泡、核染色质聚集、核碎裂,部分细胞可见凋亡小体,处于有丝分裂中期细胞明显减少。与BaF3-MIGR1和Bp210细胞相比,BaF3-MIGR1-Hspa42和Bp210-Hspa42细胞的凋亡率显著增加(P<0.05);Bcl-2蛋白的表达水平下调,Bax蛋白的表达水平无明显变化。结论干扰Apg-2基因表达可促进BaF3-MIGR1和Bp210细胞凋亡增加,其可能是通过降低抗凋亡蛋白Bcl-2的表达水平来实现的。     

脊髓灰质炎病毒诱导细胞凋亡过程中bcl-2基因家族表达的研究

目的 研究脊髓灰质炎病毒感染与细胞凋亡的关系及凋亡过程中bcl-2基因家族的表达特点。方法 采用人胚肺二倍体细胞(KMB17),在脊髓灰质炎病毒(Poliovirus,PV)感染后不同时间经RT-PCR等方法分析凋亡过程中bcl-2基因家族(bcl-2、bax、bak)转录水平的表达情况。结果 PV感染后诱导细胞凋亡过程中bcl-2家族中抗凋亡基因和促凋亡基因的表达均呈现趋势变化,bak和bax表达增强、bcl-2表达较弱。结论 bcl-2基因家族中抗凋亡基因和促凋亡基因表达水平的差异是脊髓灰质炎病毒诱导凋亡的机制之一。     

血管内皮生长因子受体3和神经纤毛蛋白2对胃癌SGC-7901细胞增殖和凋亡的影响

目的探讨分别阻断和联合阻断血管内皮生长因子受体3(Vascular endothelial growth factor receptor 3,VEGFR3)及神经纤毛蛋白2(Neuropilin 2,NRP2)基因的表达对人胃癌SGC-7901细胞株增殖和凋亡的影响。方法将SGC-7901细胞株分为3大组,VEGFR3阻断组、NRP2阻断组和VEGFR3+NRP2阻断组,各大组中又包含空白对照组、脂质体转染组、无义链转染组(NSODN组)和不同浓度反义链转染组(ASODN组)。转染后的各组SGC-7901细胞株经RT-PCR法检测VEGFR3-mRNA及NRP2-mRNA的转录水平。分别采用MTT法和流式细胞术检测细胞的增殖和凋亡情况。结果反义链转染组VEGFR3-mRNA和NRP2-mRNA的转录水平明显低于其各自的空白对照组、脂质体转染组和NSOND组,表明该组成功阻断基因VEGFR3和NRP2的表达。各组细胞的增殖和凋亡情况差异有统计学意义(P<0.05),并呈剂量和时间依赖性。在相同条件下,单独转染VEGFR3-ASODN组对胃癌细胞增殖的抑制及促凋亡作用优于单独转染NRP2-ASODN组,而联合转染组对细胞增殖的抑制及促凋亡作用最明显。结论阻断VEGFR3基因的表达对细胞增殖凋亡的影响大于阻断NRP2基因,联合阻断两个基因的表达,对细胞增殖和凋亡的影响明显大于单独阻断组。     

Increased cardiomyocyte apoptosis following ischemia and reperfusion in diet-induced hypercholesterolemia: relation to Bcl-2 and Bax proteins and caspase-3 activity

It has been reported that apoptosis is a significant contributor to myocardial cell death as a result of reperfusion injury. However, whether the extent of cardiomyocyte apoptosis following ischemia and reperfusion varies in different pathophysiological backgrounds is still uncertain. In this study, we examined whether hypercholesterolemia increases the extent of myocardial reperfusion injury by aggravating cardiomyocyte apoptosis and the effects of hypercholesterolemia on the expression of Bcl-2 and Bax proteins and the activation of caspase-3. Twenty-eight male New Zealand white rabbits were fed standard chow (control, n=14) or chow supplemented with 1% cholesterol (hypercholesterolemic, n=14) for 8 wk. Anesthetized rabbits were then subjected to 30 min of left circumflex artery occlusion followed by 4 h of reperfusion. Apoptosis was identified as “DNA ladders” by gel electrophoresis and confirmed histologically using the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay. The infarct size (% of risk region) was significantly greater in hypercholesterolemic rabbits than in controls (39±6 vs. 23±2%, P=0.02). Very few TUNEL-positive cardiomyocytes could be identified in the nonischemic regions in both groups, consistent with an absence of DNA laddering. In contrast, TUNEL-positive cardiomyocytes were significantly displayed in the ischemic, nonnecrotic myocardium, and DNA ladder occurred in all animals. The percentage of TUNEL-positive cardiomyocytes in the ischemic nonnecrotic myocardium was significantly higher in hypercholesterolemic rabbits compared with controls (40±5 vs. 17±1%, P<0.001). Western blot analysis showed that, in the nonischemic myocardium, hypercholesterolemic rabbits exhibited an approximately 50% increase in the expression of Bcl-2 (P<0.05), but not Bax, than control rabbit. However, compared with controls, hypercholesterolemic rabbits exhibited a more pronounced decrease in the expression of Bcl-2 (42±4 vs. 26±2%, P<0.01) and a similar extent of increase in the expression of Bax in the ischemic myocardium. Furthermore, hypercholesterolemic rabbits were associated with a markedly increased activation of caspase-3 within the ischemic myocardium compared to control rabbits. This study demonstrates that although hypercholesterolemia is associated with an increased myocardial Bcl-2/Bax ratio at baseline, it still significantly exacerbates cardiac reperfusion injury, not only by increasing the infarct size but also by increasing the extent of cardiomyocyte apoptosis.     

RNA干扰her-2基因对骨肉瘤细胞血管内皮生长因子-A和白细胞介素-8表达的影响

目的探讨her-2基因沉默对人骨肉瘤细胞株saos-2中血管内皮生长因子-A(Vascular endothelial growth factor-A,VEGF-A)和白细胞介素-8(Interleukin-8,IL-8)表达的影响。方法构建her-2 shRNA重组表达质粒,转染至骨肉瘤细胞株saos-2,同时设空白对照组和shNC阴性对照组;RT-PCR检测her-2、VEGF-A和IL-8基因mRNA的转录水平;Western blot检测her-2蛋白表达的变化;ELISA法检测细胞培养液中VEGF-A和IL-8的分泌水平。结果构建的her-2 shRNA表达载体能抑制her-2基因的表达,对her-2基因mRNA的转录和蛋白表达的抑制率分别为63.05%和62.59%;转染重组质粒her-2 shRNA后VEGF-A和IL-8基因mRNA的转录水平及蛋白分泌水平均显著降低(P<0.01)。结论 her-2基因沉默后,VEGF-A和IL-8基因mRNA的转录水平和蛋白表达水平明显降低,her-2基因参与了骨肉瘤细胞VEGF-A和IL-8基因的表达调控,提示her-2基因可作为研究骨肉瘤血管生成分子机理的新靶点。     

Knockdown of akt sensitizes osteosarcoma cells to apoptosis induced by Cisplatin treatment

Akt plays an important role in the inhibition of apoptosis induced by chemotherapy and other stimuli. We therefore investigated if knockdown of Akt2 promoted drug-induced apoptosis in cultured osteosarcoma cells in vitro. SAOS-2 cells were transfected with Akt2 siRNA. The sensitivity of the transformed cell line to the chemotherapeutic drug cisplatin was assessed. Reduced expression of Akt2 did not directly inhibit the growth rate of the transfected cells; however, it significantly increased their sensitivity to cisplatin. Knockdown of Akt2, together with cisplatin treatment, promoted the expression of p53 up-regulated modulator of apoptosis (PUMA). It is possible that the augmentation of cisplatin cytotoxicity may be mediated by PUMA activation. The results of this study suggest that knockdown of Akt2 expression may have therapeutic applications in enhancing the efficacy of chemotherapy in patients with osteosarcoma.     

牦牛肝脏蛋白对人肝癌HepG2细胞增殖及凋亡的影响

目的检测牦牛肝蛋白BGP对人肝癌HepG2细胞增殖及凋亡的影响,并探讨其体外抗癌活性。方法用不同浓度的BGP分别作用于人肝癌HepG2细胞,作为实验组,同时设未处理细胞对照组和空白对照组,采用MTT法检测BGP(25、50和100 mg/L)作用HepG2细胞12、24、36和48 h对细胞增殖活性的影响,并于倒置显微镜下观察细胞形态变化;采用流式细胞仪检测BGP(25、50、75、100 mg/L)作用HepG2细胞24 h,对细胞周期及凋亡的影响。结果不同浓度的BGP均可抑制HepG2细胞增殖,与未处理细胞对照组相比,差异均有统计学意义(P<0.05),其中100 mg/L BGP作用48 h,对HepG2细胞抑制率最高(94.99%)。各浓度BGP实验组HepG2细胞形态发生明显改变,细胞间隙加大,细胞间连接不牢固,胞内颗粒增多,呈现生长受阻状态,甚至有细胞脱落,细胞数目减少,其中100 mg/L BGP作用48 h,凋亡细胞明显增多。不同浓度BGP作用HepG2细胞24 h后,均可不同程度抑制HepG2细胞生长并诱导细胞凋亡;与未处理细胞对照组相比,S期细胞比例明显升高(除25 mg/L BGP实验组),G0/G1期和G2/M期细胞比例明显下降,差异均有统计学意义(P<0.05)。结论牦牛肝蛋白BGP可抑制HepG2细胞增殖,并促进凋亡,具有明显的体外抗肝癌活性。     

A novel bis-aziridinylnaphthoquinone with anti-solid tumor activity in which induced apoptosis is associated with altered expression of Bcl-2 protein

Aziridine-containing compounds have been of interest as anticancer agents since the late 1970s. The design, synthesis, and study of aziridinylnaphthoquinone analogues to obtain compounds with enhanced activity/toxicity profiles are an ongoing research effort in our group. A series of bis-aziridinylnaphthoquinone derivatives has been prepared, and the cytotoxic activities of these synthetic bis-aziridinylnaphthoquinone derivatives has been investigated. The synthetic derivatives displayed significant cytotoxicity against human carcinoma cell lines and weak cytotoxic activities against skin fibroblasts (SF). The bis-aziridinylnaphthoquinone 1 c was the most effective of the tested analogues at reducing the viability of Hep2 cells, with an LD(50) value of 5.23 microM, and also exhibited weak cytotoxic activity against SF cells, with an LD(50) value of 54.12 microM. The DNA alkylation and DNA interstrand cross-linking abilities of 1 c were also investigated. Bis-aziridinylnaphthoquinone 1 c was an effective agent for alkylation of DNA after chemical reduction in vitro, and its bifunctional alkylating moieties were able to cross-link DNA. We also report here our efforts to determine direct antitumor effects of 1 c on Hep2 cells. Growth arrest in Hep2 cells was preceded by early induction of G(2)-M cell cycle arrest at 0.75 microM of 1 c after culture for 24 h, and was then followed by apoptosis after 60 h. This was associated with decreased expression of antiapoptotic bcl2 protein (by 78 %) upon culture with 3.0 microM of 1 c after 60 h. Our results suggest that 1 c is a novel antitumor aziridinylnaphthoquinone with therapeutic potential against solid tumors.     

Effect of methylmercuric chloride on gangliosides of mouse neuroblastoma cells in culture

The effect of methylmercuric chloride (CH3HgCl) on the levels of gangliosides in mouse neuroblastoma cells (NBP2) in culture was studied. The treatment of NB cells with low concentrations (0.1 microM and 0.2 microM) of CH3HgCl, which did not affect the growth rate or morphology, caused an increase in the level of the GM3 ganglioside without changing the level of other gangliosides. The treatment of NB cells with higher concentrations (0.5 microM and 1 microM) of CH3HgCl, which inhibited the growth of NB cells, caused a decrease in the level of GM3 and an increase in the level of GM2. These results show that alterations in the levels of specific gangliosides can be observed in cells which do not exhibit any detectable change in growth rate or morphology. This change may be associated with subtle changes in brain functions, including behavioral and psychological changes, after exposure to low concentrations of organic mercury.     

白介素-17对骨髓瘤细胞增殖和凋亡的影响

目的探讨白介素-17(interleukin-17,IL-17)对骨髓瘤细胞株RPMI8226增殖和凋亡的影响及骨髓瘤细胞株IL-17R的表达。方法体外培养RPMI8226细胞,取对数生长期的细胞,分别加入浓度为25、50、100、200、500 ng/ml的rh IL-17(另设不加rh IL-17的对照组),共同培养72 h后,采用MTT法检测IL-17对RPMI8226细胞增殖的影响;TUNEL法检测IL-17对RPMI8226细胞凋亡的影响。将BALB/c雌性小鼠随机分为试验组和对照组,分别经腹部皮下注射含100 ng/ml IL-17和不含IL-17的RPMI8226细胞(5×106个),观察肿瘤生长情况。应用流式细胞术检测RPMI8226细胞IL-17R的表达。结果不同浓度的IL-17与对照组相比,均可促进RPMI8226细胞的增殖(P﹤0.05),抑制细胞凋亡(P﹤0.05)。经IL-17处理的RPMI8226细胞荷瘤小鼠与对照组相比,成瘤时间缩短(P﹤0.05),肿瘤体积增大(P﹤0.05)。RPMI8226细胞显著表达IL-17R。结论 IL-17在体内外均可促进RPMI8226细胞增殖,抑制其凋亡;RPMI8226细胞显著表达IL-17R。     

Effect of the polymer matrices on the immobilisation of microbial cells by radiation polymerisation

Streptomyces phaeochromogenes cells were immobilised by radiation polymerisation, at low temperature, using various acrylate and diacrylate monomers. The form and enzymatic activity of the immobilised cell composites were affected by the molecular structure of the monomers. The activities of the composites from acylate and diacrylate monomers increased with increased numbers of methylene or ethylene glycol units in the monomers. The water content of the immobilised cell composites was also affected by the molecular structure of the monomers. The pH and heat stabilities of the immobilised cell composites were increased when the polymer matrix had a porous sponge structure.     

TiO2薄膜玻璃钢化后光照超亲水性的研究

采用无机钛盐硫酸氧钛为原料,在玻璃基片上获得TiO2超亲水性涂层后,在680℃对玻璃基片进行了钢化处理.实验表明,该TiO2涂层在钢化后仍具有均匀的表面结构、高的可见光透过率和良好的光照超亲水效果,从而在玻璃建材行业具有广泛的实际应用前景.