土槿皮乙酸B不通过Fas途径诱导人乳腺癌MCF-7细胞凋亡和M期周期阻滞

目的初探土槿皮乙酸B(PAB)诱导人乳腺癌MCF-7细胞凋亡和周期阻滞。方法MTT法测定PAB对MCF-7细胞的生长抑制情况;相差显微镜观察细胞形态变化;荧光显微镜观察经Hoechst33258染色的DNA变化;流式细胞仪检测用PI染色后MCF-7细胞的周期分布;免疫印迹实验检测相关蛋白的表达。结果PAB时间剂量依赖性的抑制MCF-7细胞生长。4μmol.L-1PAB在24h使DNA皱缩,在36和48h使DNA皱缩的细胞死亡。4μmol.L-1PAB时间依赖性的促进PARP〔poly-(ADP-ribose)polymerase〕的剪切。在36hPAB剂量依赖性的增加cdc2和核内cyclinB1的表达。Fas拮抗性抗体UB2不影响PAB诱导的凋亡,但Fas激动性抗体CH11促进PAB诱导的凋亡。并且UB2不影响PAB诱导的细胞周期阻滞,Fas激动性抗体CH11不影响G1和S期,但促进凋亡特征性的亚二倍体峰生成。结论4μmol.L-1的PAB通过凋亡方式可明显地抑制MCF-7细胞生长,并促进M期阻滞。Fas途径不参与PAB诱导的凋亡和周期阻滞。     

Serum carnitine and disabling fatigue in multiple sclerosis

Abstract The serum concentrations of total, free and acylcarnitine were compared in 25 patients with multiple sclerosis (MS) and among age- and sex-matched normal controls by the new enzymatic cycling method in order to clarify whether the fatigue in MS might be due to possible carnitine-related fatty acid metabolic abnormalities in the mitochondria of skeletal muscles. Patients with MS were divided into those with and those without excessive fatigue. Levels of total and free carnitine were not significantly different between MS patients and normal controls. Levels of acylcarnitine, whose decrease in chronic fatigue syndrome has been reported, were also similar between MS patients and normal controls. There was no difference in these carnitine levels between MS patients with and without excessive fatigue. We argue that acylcarnitine deficiency and fatty acid metabolic dysfunction in mitochondria are not relevant to the excessive fatigue in patients with MS, and further explanatory investigations are to be sought.     

A Case of Zollinger-Ellison Syndrome whose Pancreatic Tumor Produced Multiple Hormones and a Review of 48 Cases Reported in the Japanese Literature

A 46-year-old man developed a peptic ulcer disease and a diagnosisof Zollinger-Ellison Syndrome was strongly suspected followinggastric acid studies. Plasma gastrin level was found to be elevated.The operation revealed a pancreatic tumor localized at the pancreastail. The resected tumor tissue was proved to contain largeamounts of immunoreactive gastrin. In addition, calcitonin,VIP and insulin were found to be present either as a resultof immunofluorescence studies or the respective radioimmunoassays.Therefore, this was a case of a multiple hormone producing tumorof pancreas islet cell origin, and the symptoms due to gastrinhypersecretion were the main clinical features. In addition,48 cases of Zollinger-Ellison Syndrome reported in Japaneseliteratures were reviewed.     

水飞蓟宾对异丙肾上腺素引起的大鼠乳鼠心肌细胞损伤的保护作用及其机制

水飞蓟宾(silibinin)为从菊科植物水飞蓟(Silybum marianum)的种子和果实中提取得到的黄酮类单体成分。本研究观察水飞蓟宾对β-肾上腺素受体激动剂异丙肾上腺素对培养乳鼠心肌细胞损伤的影响，并对其机制进行研究。采用MTT法测定细胞存活率，酶联法测定细胞丙二醛(maleic dialdehyde，MDA)和细胞培养液中乳酸脱氢酶(lactate dehydrogenase，LDH)的含量以及超氧化物歧化酶(superoxide dismutase，SOD)的活性，流式细胞仪测定线粒体膜电位(ΔΨ)，以及Western blotting检测与线粒体相关蛋白的表达。与模型组相比，水飞蓟宾使细胞受损伤的程度降低，并且增加SOD的活性，抑制了细胞膜电位的降低，并且改善Bcl-2家族蛋白中Bax/Bcl-2的表达比率，上调Bax上游去乙酰化酶SIRT1蛋白的表达。水飞蓟宾通过上调线粒体上游Bax/Bcl-2的表达比率与SIRT1蛋白的表达，改善了线粒体的功能，从而对由异丙肾上腺素引起的培养乳鼠心肌细胞损伤有明显的保护作用。     

oridonin部分通过TNFα信号转导途径诱导小鼠成纤维L929细胞凋亡

目的比较冬凌草甲素(oridonin)和TNFα诱导小鼠成纤维L929细胞凋亡的分子机制。方法MTT法、Hoechst33258荧光染色、DNA片断化分析和Western blot分析法。结果Oridonin和TNFα均能诱导L929细胞发生凋亡,其半数有效抑制浓度IC50分别为(24·8±1·2)μmol·L-1和(20·9±1·9)μg·L-1。Oridonin和TNFα均能引起L929细胞凋亡形态学变化,TNFα处理过的细胞在琼脂糖凝胶电泳上可见典型的凋亡DNA梯状条带,但是oridonin处理的细胞却不能,称之为非典型凋亡;caspase-3,-8抑制剂和caspase家族抑制剂能明显得促进25μmol·L-1oridonin和20μg·L-1TNFα诱导的L929细胞凋亡,caspase-9抑制剂只能促进oridonin诱导的L929细胞凋亡;ERK的抑制剂PD98059能明显的抑制oridonin和TNFα诱导的L929细胞凋亡,但是p38的抑制剂SB203580只能抑制TNFα诱导的L929细胞凋亡;在L929细胞中oridonin能促进内源性pro-TNFα的表达和其上游蛋白IκB的磷酸化。结论Oridonin通过激活转录因子NF-κB而促进内源性pro-TNFα的表达,并且部分通过细胞因子TNFα信号转到途径诱导L929细胞凋亡。     

薯蓣苷元诱导人黑素瘤细胞A375-S2凋亡依赖半胱天冬酶和MAPK途径

目的　研究薯蓣苷元诱导人黑素瘤细胞A375 S2凋亡的机制。方法　MTT法测定细胞生长抑制率及半胱天冬酶和有丝分裂原活化的蛋白激酶(MAPK)抑制剂对薯蓣苷元诱导细胞凋亡的影响。电镜观察细胞形态变化。流式细胞仪检测细胞凋亡及周期分布。用半胱天冬酶活力检测试剂盒测定半胱天冬酶活力。结果　薯蓣苷元抑制A375 S2细胞的生长呈时间 剂量依赖性。经薯蓣苷元处理后的A375 S2细胞表现出典型的凋亡特征 :细胞表面微绒毛消失、胞质空泡化、染色质浓集、边聚。流式细胞仪检测表明薯蓣苷元导致DNA片段化和细胞周期阻滞在G0 /G1期。半胱天冬酶家族抑制剂 (z VAD fmk )和p38MAPK抑制剂 (SB2 0 35 80 )可部分抑制薯蓣苷元诱导的A375 S2细胞凋亡。结论薯蓣苷元可诱导A375 S2细胞凋亡。其诱导凋亡作用与半胱天冬酶及MAPK的活化相关。