脑脊液S-100B与儿童病毒性脑炎脑脊液蛋白组学关系的研究

目的分析病毒性脑炎(VE)患儿和对照组儿童脑脊液(CSF)蛋白质组的表达差异,筛选VE特异性蛋白,探讨其与VE的关系,为VE的早期诊断提供线索。方法以三氯醋酸/丙酮沉淀法提取VE患儿和对照组儿童CSF总蛋白,固相pH梯度二维聚丙烯酰胺凝胶电泳(2-DE)技术分离蛋白质,应用双向电泳凝胶分析软件(PDQuest 7.3.1)对2-DE凝胶进行量化比较分析,识别差异表达明显的蛋白质点,应用基质辅助激光解吸电离飞行时间质谱(MALDI-TOF-MS)得到肽质量指纹图谱(PMF),在Mascot数据库中进行蛋白质匹配,鉴定部分差异蛋白质。结果VE患儿和对照组CSF蛋白2-DE凝胶图谱上分别平均显示442和401个点,有23个点蛋白质表达存在2倍以上的差异,选取5个表达明显上调的蛋白质点进行质谱鉴定,成功鉴定出钙结合蛋白S100B。结论钙结合蛋白S100B在VE患儿和无中枢神经系统病变的对照组儿童CSF的蛋白表达上存在明显差异,可能是VE密切相关的疾病特异性蛋白,并有可能成为VE诊断的分子标志物。     

应用SELDI—TOFMS技术筛选乳腺癌蛋白标志物

目的：应用表面增强激光解吸电离飞行时间质谱技术（ SELDI-TOF MS）筛选乳腺癌的特异性蛋白标志物,建立诊断模型。方法用表面增强激光解吸电离飞行时间质谱仪及CM10蛋白芯片检测35例乳腺癌患者标本及53例对照组标本（包括35例乳腺良性病变和18例正常人）的血清蛋白指纹图谱,Ciphergen Proteinchip 软件自动采集数据,Ciphergen Biomaker Wizard 软件筛选差异蛋白,Biomarker Pattern软件建立乳腺癌的分类树诊断模型。结果乳腺癌组及对照组血清蛋白质谱图共检测到59个蛋白质峰,其中19个蛋白峰表达差异具有显著性（P＜0．01）。以2个蛋白质峰（质荷比分别为M6636．62,M13889．6）建立的诊断模型,诊断的准确率达到94．3％,灵敏度和特异度分别为80．0％和71．7％。结论 SELDI-TOF MS技术可用于乳腺癌特异性蛋白的筛选,为其快速诊断奠定基础。     

膀胱癌BIU-87细胞羟基喜树碱耐药的蛋白质组学研究

目的研究与膀胱癌BIU-87细胞羟基喜树碱（HCPT）耐药相关的蛋白质。方法应用二维凝胶电泳（two-dimensionalelectrophoresis，2-DE）和基质辅助激光解吸电离一串行飞行时间质谱（matrix-assistedlaserdesorption-ionizationtimeofflighttandemmassspectrometry，MALDI-TOF-TOF）寻找羟基喜树碱耐药的膀胱癌BIU-87细胞与非耐药细胞的差异表达蛋白质。结果通过对2组细胞总蛋白质二维凝胶电脉图谱进行分析，找到差异蛋白质点12个；通过质谱分析，12个蛋白质均得到鉴定。这些蛋白质包括热休克蛋白27、细胞角蛋白8、nm23蛋白等。结论通过蛋白质组学技术，发现了膀胱癌羟基喜树碱耐药细胞和非耐药细胞之间差异表达蛋白质12个，这些差异蛋白质可能参与膀胱癌细胞羟基喜树碱耐药的过程。     

松果菊苷对过氧化氢损伤的PC12细胞的保护作用及机制研究

目的研究松果菊苷(echinacoside,ECH)对过氧化氢(H2O2)诱导的PC12细胞损伤的保护作用及机制。方法用终浓度为0.4 mmol.L-1的H2O2损伤PC12细胞,测定细胞存活率和Na+,K+-ATP酶的活性;用激光共聚焦法(LSCM)检测线粒体膜电位(MMP);用RT-PCR法检测Bcl-2和p53 mRNA表达量的变化。结果10 mg.L-1松果菊苷可以提高H2O2损伤的PC12细胞存活率和Na+,K+-ATP酶的活力、升高线粒体膜电位、降低p53 mRNA水平但增高Bcl-2 mRNA水平(P<0.05或P<0.01)。结论松果菊苷可保护H2O2诱导的PC12细胞损伤,升高MMP、下调p53mRNA和上调Bcl-2 mRNA可能是其作用机制。     

甲基苯丙胺对体外培养SH-SY5Y细胞线粒体膜电位、超微结构及Mfn1、Fis1蛋白表达的影响

目的评估甲基苯丙胺(METH)对体外培养的SHSY5Y细胞线粒体膜电位(MMP)、线粒体超微结构及Mfn1、Fis1蛋白表达的影响。方法 SH-SY5Y细胞中加入METH(0. 0、1. 0、1. 5、2. 0 mmol·L~(-1)),培养3、6、12、24 h; JC~(-1)法检测SH-SY5Y细胞MMP;透射电镜观察SH-SY5Y细胞线粒体超微结构; Western blot检测Mfn1、Fis1蛋白表达。结果METH作用SH-SY5Y细胞3、6、12、24 h,与对照组比较,METH组细胞MMP红绿荧光比值明显降低(P <0. 05),Mfn1蛋白表达降低(P <0. 05),Fis1蛋白表达升高(P <0. 05); METH作用SH-SY5Y细胞24 h时,透射电镜观察见未处理组细胞线粒体呈椭圆形棒状双层膜结构,线粒体嵴正常、清晰,METH组细胞线粒体椭圆形棒状结构被分裂成小球状结构,并发现线粒体自噬小体及自噬溶酶体。结论METH可引起SH-SY5Y细胞MMP下降、线粒体超微结构改变及Mfn1、Fis1蛋白表达水平改变,其改变可能参与METH致神经细胞损伤的发病机制。     

Ⅰ期非小细胞肺癌相关血清差异表达蛋白的研究

目的:寻找Ⅰ期非小细胞肺癌(NSCLC)与健康人血清的差异表达蛋白.方法:收集天津市胸科医院经手术、病理证实的6例Ⅰ期NSCLC患者血清,等量混合后设为肺癌组;同期15例健康体检血清,等量混合后设为健康对照组.利用双向凝胶电泳(2-DE)和基质辅助激光解吸/电离飞行时间质谱(MALDI-TOF-MS)分离、筛选和鉴定2组间的差异表达蛋白.结果:成功获得了2组的双向凝胶电泳图谱,PDquest软件分析显示,2组间差异大于2倍的蛋白质点共有128个,质谱鉴定后确定了10种蛋白质,其中7种表达量上调,分别为α1-酸性糖蛋白、C1酯酶抑制物、血管紧张素原、转铁蛋白、转甲状腺素蛋白、间-α-胰蛋白酶抑制剂重链H2及无花果酶-3;3种表达量下调,分别为纤连蛋白、补体C4-A及补体C3.结论:应用2-DE及MALDI-TOF-MS在Ⅰ期NSCLC血清中鉴定出4种与肿瘤关系密切的差异表达蛋白,可作为开发NSCLC早期诊断标志物的候选蛋白.     

顺铂处理肝癌细胞SMMC-7721的蛋白质组学分析

目的:用蛋白质组技术分析顺铂(cisplatin,DDP)作用于肝癌SMMC-7721细胞后细胞内蛋白质组的变化.方法:采用四氮唑蓝还原反应法(MTT)测定细胞生长抑制率.顺铂(10 mg·L-1)作用肝癌SMMC-7721细胞24 h,分别收集顺铂处理组与对照组细胞,提取细胞内总蛋白并采用双向电泳(2-DE)分离,Image Master 2D Platinum软件分析顺铂处理前后差异表达蛋白质,切取明显差异点,基质辅助激光解吸飞行时间质谱(MALDI-TOF-MS)鉴定差异蛋白.结果:顺铂可抑制肝癌SMMC-7721细胞的生长,其抑制作用具有剂量及时间依赖性.质谱鉴定出4个已知序列的差异蛋白点.结论:顺铂处理后肝癌SMMC-7721细胞内差异表达的蛋白可能与顺铂的抗肿瘤作用机制有关.     

奇果菌素促进宫颈癌HeLa细胞凋亡的蛋白质组研究

目的寻找与奇果菌素促进宫颈癌HeLa细胞凋亡相关的蛋白质。方法随机将宫颈癌HeLa细胞分成两组,一组为对照组,另一组以奇果菌素(剂量为半数抑制率)处理24 h。提取蛋白质做双向电泳(2-dimensional electrophoresis,2-DE),基质辅助激光解吸/离子化飞行时间质谱仪(matrix-assisted laser desorption/ionization time-of-flight mass spectros-copy,MALDI-TOF-MS)鉴定2组细胞间有明显差异表达的蛋白质。结果奇果菌素作用于HeLa细胞的蛋白质组,质谱鉴定出6种蛋白质表达差异有显著性,分别是:塌陷反应介导蛋白1(CRMP-1)、转胶蛋白2(Transgelin-2)、磷酸化应激诱导蛋白1(StIP1)、腺苷酸环化酶(ATPase)、磷酸甘油酸变位酶1(PGM-1)和原肌球蛋白4(TPM-4);其中StIP1表达下调,其他蛋白均上调。结论奇果菌素能够通过诱导宫颈癌HeLa细胞发生凋亡而发挥抑制HeLa细胞生长作用,奇果菌素可能通过上调或下调上述蛋白质的表达参与促进宫颈癌HeLa细胞的凋亡。     

瓜子金皂苷丙对MPP~+诱导PC12细胞凋亡的抑制作用

目的观察瓜子金皂苷丙对MPP+诱导的PC12细胞凋亡的影响,并且探讨其作用机制。方法采用MTT法检测细胞存活率,碘化丙啶染色流式细胞术(FCM)检测PC12细胞凋亡,Western blotting检测Bax和Bcl-2蛋白的表达,罗丹明123染色FCM检测细胞线粒体膜电位(ΔΨm),荧光酶标仪检测细胞内活性氧(R0S)的含量。结果不同浓度MPP+作用PC12细胞24 h后,细胞存活率显著下降(P<0.01),细胞凋亡明显,凋亡相关蛋白Bcl-2/Bax比之下降,线粒体膜电位降低,细胞内ROS显著增加。与MPP+处理组相比,瓜子金皂苷丙10μmol·L-1组,细胞存活率显著升高(P<0.01);细胞凋亡率下降(P<0.01);Bcl-2/Bax比率增加(P<0.01),线粒体膜电位上升(P<0.01),ROS含量减少。结论瓜子金皂苷丙可以抑制MPP+诱导的PC12细胞凋亡,其作用机理可能与上调Bcl-2和下调Bax蛋白的表达,维持线粒体正常膜电位,稳定线粒体功能,清除R0S有关。     

瓜子金皂苷己对MPP~+诱导PC12细胞凋亡的保护作用

目的观察瓜子金皂苷己(polygalasaponin F,PS-F)对1-甲基-4-苯基-吡啶离子(1-methyl-4-phenylpyridinium,MPP+)诱导的PC12细胞损伤的影响,并且探讨其作用机制。方法 MTT法检测细胞存活率,Annexin V/PI染色流式细胞术检测PC12细胞凋亡,JC-1染色倒置显微镜检测细胞线粒体膜电位(mitochondrial membrane potential,MMP),Western blot检测Caspase-3蛋白的水平。结果 500μmol.L-1MPP+作用PC12细胞48 h,能明显抑制细胞生长(P<0.01),诱导细胞发生凋亡,同时降低MMP,增加活性Caspase-3的蛋白水平。同时给予不同浓度PS-F处理,PC12细胞存活率增加(P<0.01);凋亡细胞量减少;MMP增高;活性Caspase-3蛋白水平降低(P<0.01)。结论 PS-F能抑制MPP+诱导的PC12细胞的凋亡,其作用机制可能与维持线粒体正常膜电位,稳定线粒体功能,降低活性Caspase-3蛋白水平有关。     

曲古抑菌素A对细胞PANC-1株凋亡和肿瘤转移相关基因表达的影响

目的探讨曲古抑菌素A(TSA)诱导胰腺癌细胞PANC-1细胞凋亡机制。方法 TSA 0.1～0.6μmol.L-1培养PANC-1细胞0～48 h,MTT法检测细胞存活率并计算IC50。TSA 0.4μmol.L-1PANC-1培养0～48 h,Hoechst 33258染色观察细胞核形态变化。TSA 0.4μmol.L-1PANC-1培养0～12 h,检测胱天蛋白酶3活性。TSA 0.4μmol.L-1与PANC-1培养24 h,实时定量PCR检测c-myc,p53,Bcl-2,Bax,存活素,基质金属蛋白酶1(MMP1)和基质金属蛋白酶1组织抑制剂(TIMP-1)和Notch-1基因的表达。TSA 0.4和0.6μmol.L-1与PANC-1培养24 h,细胞免疫化学方法检测Notch-1蛋白的胞内活性形式NICD表达。结果TSA可以明显抑制PANC-1细胞增殖,12,24和48 h的IC50值分别为0.42,0.32和0.19μmol.L-1,具有量效(r=0.640,P=0.01)和时效(r=0.768,P=0.002)关系。Hoechst 33258染色结果表明,TSA 0.4μmol.L-1增加PANC-1细胞核的蓝色荧光并出现凋亡特征。TSA 0.4μmol.L-1作用4,8和12 h后,胱天蛋白酶3的活性分别为正常对照组的1.62±0.12,2.68±0.17和(3.92±0.23)倍。PCR结果显示,TSA 0.4μmol.L-1作用24 h后,p53,c-myc和存活素mRNA表达下降,分别为对照组的(18.3±5.1)%,(24.2±0.9)%和(15.8±1.0)%,Bcl-2和Notch-1 mRNA未见明显变化,而Bax,MMP1和TIMP-1 mRNA升高(P<0.05),Bcl-2/Bax比值降低到正常对照组的(13.0±2.8)%。Notch-1活性分子NICD明显升高(P<0.05)。结论TSA可通过线粒体途径诱导胰腺癌PANC-1细胞凋亡,而且使Notch-1激活,促进转移相关基因表达。     

Study of the mechanism underlying the role of PINK1/Parkin in the formic acid-induced autophagy of PC12 cells

This study aimed to explore PINK1/Parkin's role in methanol metabolite formic acid-induced autophagy in PC12 cells and provide a theoretical basis for elucidating methanol-induced neurotoxicity. After treatment with different formic acid concentrations, we observed the morphology and mitochondria of PC12 cells. We used an ultra-micro enzyme kit to detect the mitochondrial Na⁺-K⁺-ATPase and Ca²⁺-Mg²⁺-ATPase activities; a JC-1 kit to detect changes in the mitochondrial membrane potential (MMP); MDC staining to detect the autophagy levels; and western blotting to measure the expression levels of the mitochondrial marker protein COX IV and the autophagy-related proteins Beclin1, P62 and LC3II/LC3I, and the mitochondrial and cytoplasmic levels of PINK1, Parkin and P-Parkin. Compared with the control group, the mitochondrial diameters, the mitochondrial Na⁺-K⁺-ATP and Ca²⁺-Mg²⁺-ATPase activities, the MMP, and the COX IV expression levels decreased significantly (P < 0.05). The fluorescence signal intensity (indicating autophagy); relative Beclin1 and LC3II/LC3I protein expression levels; and relative mitochondrial PINK1, Parkin and P-Parkin levels increased significantly, and the relative P62 protein expression levels and relative cytoplasmic PINK1, Parkin and P-Parkin levels decreased significantly (P < 0.05) compared with the control group. Thus, formic acid alters mitochondrial morphology, causes mitochondrial dysfunction, affects the PINK/Parkin pathway and, thus, activates the process of mitochondrial autophagy.     

Quercetin 3-O-methyl ether protects FL83B cells from copper induced oxidative stress through the PI3K/Akt and MAPK/Erk pathway

Quercetin is a bioflavonoid that exhibits several biological functions in vitro and in vivo. Quercetin 3-O-methyl ether (Q3) is a natural product reported to have pharmaceutical activities, including antioxidative and anticancer activities. However, little is known about the mechanism by which it protects cells from oxidative stress. This study was designed to investigate the mechanisms by which Q3 protects against Cu^2 +-induced cytotoxicity. Exposure to Cu^2 + resulted in the death of mouse liver FL83B cells, characterized by apparent apoptotic features, including DNA fragmentation and increased nuclear condensation. Q3 markedly suppressed Cu^2 +-induced apoptosis and mitochondrial dysfunction, characterized by reduced mitochondrial membrane potential, caspase-3 activation, and PARP cleavage, in Cu^2 +-exposed cells. The involvement of PI3K, Akt, Erk, FOXO3A, and Mn-superoxide dismutase (MnSOD) was shown to be critical to the survival of Q3-treated FL83B cells. The liver of both larval and adult zebrafish showed severe damage after exposure to Cu^2 + at a concentration of 5 μM. Hepatic damage induced by Cu^2 + was reduced by cotreatment with Q3. Survival of Cu^2 +-exposed larval zebrafish was significantly increased by cotreatment with 15 μM Q3. Our results indicated that Cu^2 +-induced apoptosis in FL83B cells occurred via the generation of ROS, upregulation and phosphorylation of Erk, overexpression of 14-3-3, inactivation of Akt, and the downregulation of FOXO3A and MnSOD. Hence, these results also demonstrated that Q3 plays a protective role against oxidative damage in zebrafish liver and remarked the potential of Q3 to be used as an antioxidant for hepatocytes.     

Mechanisms of thiosulfinates from Allium tuberosum L.-induced apoptosis in HT-29 human colon cancer cells

This study was performed to elucidate the apoptotic pathways by thiosulfinates, major biologically active components of Allium tuberosum L., in HT-29 human colon cancer cells. Thiosulfinates significantly induced cell death in dose- and time-dependent manners in HT-29 cells, which is associated with apoptosis. Thiosulfinates activated the initiator caspase-8, and -9, and the effector caspase-3. In the present study, thiosulfinates were found to stimulate Bid cleavage, indicating that the apoptotic action of caspase-8-mediated Bid cleavage leads to the activation of caspase-9. Thiosulfinates down-regulated the expression of the anti-apoptotic protein Bcl-2, and up-regulated the expression of the pro-apoptotic protein Bax. We also found that thiosulfinates increased the expression of AIF, a caspase-independent mitochondrial apoptosis factor, and induced DNA fragmentation and chromatin condensation in HT-29 cells. These results indicate that thiosulfinates from A. tuberosum L. inhibited cell proliferation and activated both the caspase-dependent and caspase-independent apoptotic pathways in HT-29 cells.     

白藜芦醇通过上调小鼠胚胎干细胞过氧化物酶体增殖激活受体γ共激活子1α表达促进其分化为心肌细胞

目的观察白藜芦醇对小鼠胚胎干细胞(ESC)分化为心肌细胞的调节作用,并探讨其机制。方法 采用悬滴悬浮培养法培养ESC。白藜芦醇0.44,4.4和44μmo.lL-1处理ESC 96 h。光学显微镜下记录每组自发心肌搏动数;透射电镜观察细胞内线粒体结构;实时PCR方法测定α-肌球蛋白重链(α-MHC)、过氧化物酶体增殖物激活受体γ(PPARγ)、PPARγ共激活子1α(PGC-1α),核呼吸因子-1(NRF-1)、线粒体转录因子A(mtTFA)和线粒体呼吸链复合体Ⅳ(COXⅣ)的基因表达;Western蛋白印迹法检测PPARγ,α辅肌动蛋白和PGC-1α蛋白表达。结果 与正常对照组相比,白藜芦醇0.44和4.4μmo.l L-1可增加ESC细胞分化为自发搏动的心肌细胞数,并明显上调分化的ESC心肌特异性基因α-MHC表达,约分别为正常对照组的5.6和3.7倍;上调心肌细胞特定标识蛋白α辅肌动蛋白的表达,约为正常对照组的1.7和2.1倍;提示白藜芦醇可以促进ESC分化为心肌细胞。白藜芦醇干预各组均可上调PPARγ基因和蛋白表达,同时白藜芦醇0.44和4.4μmo.lL-1可以明显上调线粒体生物合成相关因子基因表达;白藜芦醇4.4μmo.lL-1处理组线粒体数目增多,提示线粒体生物合成可能是ESC分化为心肌细胞的重要机制。结论 白藜芦醇可以通过激动PPARγ受体并上调由PGC-1α介导的线粒体生物合成,从而促进ESC分化为心肌细胞。     

小檗碱通过破坏线粒体功能选择性诱导淋巴瘤细胞的凋亡

目的研究小檗碱(BBR)对T淋巴瘤细胞凋亡的影响及机制。方法正常T淋巴细胞、T淋巴瘤细胞、Jurkat细胞用BBR 0,10,20和40μmol·L^-1处理24 h,多柔比星(Dox)40μmol·L^-1为阳性对照;Jurkat p0细胞用BBR 0和40μmol·L^-1处理24 h。流式细胞术检测细胞凋亡率,Seahorse XF24细胞代谢分析仪和H2DCFDA活性氧探针检测细胞氧消耗率(OCR)和活性氧(ROS)水平。CellTiter-Glo发光法细胞活力检测试剂盒检测细胞ATP水平,试剂盒测线粒体呼吸链复合物Ⅰ,Ⅱ,Ⅳ和Ⅴ的活性。Western印迹法检测细胞内胱天蛋白酶3、Bcl-2、Bax、NF-κB抑制蛋白激酶α/β(IKKα/β)、磷酸化IKKα/β(p-IKKα/β)、NF-κB抑制因子α(IκBα)、p-IκBα和P65蛋白表达水平。结果BBR 40 mmol·L^-1明显增加T淋巴瘤细胞和Jurkat细胞凋亡率(P<0.01),胱天蛋白酶3和Bax蛋白表达水平显著上调(P<0.01),Bcl-2表达显著下调(P<0.01),但对正常T淋巴细胞的凋亡并无影响;BBR 40 mmol·L^-1明显降低Jurkat细胞的OCR及线粒体呼吸链复合物Ⅰ活性(P<0.01),增加ROS水平(P<0.01),降低ATP水平(P<0.01),但不影响线粒体缺陷型淋巴瘤Jurkat p0细胞呼吸链和凋亡;BBR 40μmol·L-1明显下调Jurkat细胞中NF-κB通路相关蛋白p-IKKα/β/IKKα/β、p-IκBα/IκBβ和核内P65表达(P<0.01)。结论BBR通过破坏线粒体功能选择性诱导淋巴瘤T细胞的凋亡,可能与抑制NF-κB通路有关。     

去甲斑蝥素降低人胃癌细胞程序性细胞死亡因子4的表达

目的 研究去甲斑蝥素(NCTD)降低程序性细胞死亡因子4(PDCD4)表达的机制。方法MTT法测定NCTD 5~640 μmol·L^-1与人胃癌BGC-823细胞作用24,48和72 h细胞存活率;Western蛋白质印迹法测定NCTD 0, 6, 30和60 μmol·L^-1作用BGC-823细胞24 h PDCD4蛋白表达水平;NCTD 60 μmol·L^-1作用20 h后加入MG132 10 μmol·L^-1作用4 h对PDCD4蛋白表达的影响;逆转录PCR法测定NCTD 60 μmol·L^-1作用BGC-823细胞24 h后PDCD4 mRNA表达的变化;实时荧光定量PCR(qRT-PCR)测定NCTD 60 μmol·L^-1作用BGC-823细胞6, 12和24 h后microRNA-21(miR-21)的表达。Western蛋白质印迹法测定细胞转染miR-21抑制剂对PDCD4蛋白表达的影响。结果 NCTD作用后BGC-823细胞存活率明显下降,NCTD作用BGC-823细胞24, 48和72 h IC₅₀分别为74.5, 35.0和10.3 μmol·L^-1。NCTD 6, 30和60 μmol·L^-1作用于BGC-823细胞24 h,PDCD4蛋白分别降低9%, 47%和62%。NCTD对PDCD4 mRNA表达无影响。与NCTD处理组相比,MG132和NCTD共处理对PDCD4蛋白表达无明显影响。NCTD 60 μmol·L^-1作用BGC-823细胞12和24 h后,细胞中miR-21的表达显著升高(P<0.01)。细胞转染miR-21抑制剂后,可抑制NCTD降低PDCD4蛋白表达的作用。结论 NCTD通过调控miR-21降低PDCD4蛋白的表达。     

The Fusarium mycotoxins enniatins and beauvericin cause mitochondrial dysfunction by affecting the mitochondrial volume regulation,oxidative phosphorylation and ion homeostasis

The mechanisms of cell toxicity of mycotoxins of the enniatin family produced by Fusarium sp. enniatin B, a mixture of enniatin homologues (3% A, 20% A₁, 19% B, 54% B1) and beauvericin, were investigated. In isolated rat liver mitochondria, exposure to submicromolar concentrations of the enniatin mycotoxins depleted the mitochondrial transmembrane potential, uncoupled oxidative phosphorylation, induced mitochondrial swelling and decreased calcium retention capacity of the mitochondria. The mitochondrial effects were strongly connected with the potassium (K⁺) ionophoric activity of the enniatins. The observed enniatins induced K⁺ uptake by mitochondria. This shows that the enniatins acted as ionophores highly selective for potassium ions. The effects were observed in potassium containing media whereas less or no effect remained to be observed when K⁺ was partially or totally replaced by isomolar concentrations of Na⁺. The rank order of enniatin induced mitochondrial impairment was beauvericin > enniatin mixture > enniatin B. Exposure to the enniatins depleted the mitochondrial membrane potential also in intact human neural (Paju), murine insulinoma (Min-6) cells as well as boar spermatozoa. Exposure to enniatin B in media with physiological (4 mM) or low (<1 mM) but not in high (60 mM) external concentration of K⁺ induced hyperpolarization of the spermatozoal plasma membrane indicating enniatin that catalysed efflux of the cytosolic K⁺ ions. These results indicate that the cellular toxicity targets of the enniatin mycotoxins are the mitochondrion and the homeostasis of potassium ions.     

Mitochondrial apoptosis contributes to the anti-cancer effect of Smilax glabra Roxb

Smilax glabra Roxb. (SGR), a member of the Smilacaceae family and a rhizome of the Liliaceae plant, has shown anti-inflammation and detoxification properties, and a few studies reported its anti-cancer effect. In this study, we showed that SGR inhibited growth of human breast cancer cell line MCF7, colon carcinoma cell line HT-29, and gastric cancer cell line BGC-823 in a dose-dependent manner. Furthermore, SGR could inhibit tumor growth of HT-29 in Balb/c nude mice and murine hepatoma H22 cells in ICR mice. SGR elicited apoptotic cell death, as confirmed by DNA ladder formation, changes in nuclear morphology, and the increased FITC-Annexin-V/PI staining. Permeabilization of mitochondrial membrane (MMP), production of reactive oxygen species (ROS), elevation of intracellular [Ca²⁺], relocation of cytochrome c, and the activation of caspase-3 were found to be associated with the initiation of apoptosis by SGR treatment. Using microarray analysis, we found the changes in expression profiles of genes related to apoptosis, proliferation and cell cycle control in the cells treated with SGR. Our results demonstrated the mitochondrial regulation of apoptosis by which SGR exerts the anti-cancer effect.