Oncotic necrosis and caspase-dependent apoptosis during galactosamine-induced liver injury in rats

The mode of cell death during galactosamine (Gal)-induced liver injury was originally thought to be oncotic necrosis but recently it was suggested to be apoptosis. Thus, the objective was to assess whether apoptosis and oncosis are sequential or independent events in the pathophysiology. In addition, the role of caspases in Gal-induced apoptotic signaling was investigated. A dose of 500 mg/kg Gal caused a time-dependent increase in plasma alanine transaminase (ALT) levels (24 h: 430 +/- 122 U/L) in female Sprague-Dawley rats. This was accompanied by processing of procaspase-3 and significant increases in hepatic and plasma caspase-3 activities. Using morphology and TUNEL staining, apoptotic and oncotic cells were quantitated. The number of apoptotic hepatocytes increased from 0.14% in controls to 5.4 +/- 1.0% 24 h after Gal treatment. In addition, the number of cells with oncotic morphology increased from 0 to 6.9% of total hepatocytes. Treatment with the pan-caspase inhibitor IDN-7314 (10 mg/kg) or pretreatment with uridine (1 g/kg), reduced all parameters of apoptosis to baseline. However, IDN-7314 administration did not affect plasma ALT activities and the number of oncotic cells at 6 h and only modestly reduced these parameters at 24 h. Uridine, on the other hand, prevented the increase of plasma ALT levels and reduced the number of apoptotic and oncotic cells by >80%. In conclusion, galactosamine-induced hepatocellular apoptosis in rats is caspase dependent. Although some of the apoptotic cells may undergo secondary necrosis, a significant number of hepatocytes die through oncotic necrosis as an independent mechanism of cell death.     

Lovastatin-induced cardiac toxicity involves both oncotic and apoptotic cell death with the apoptotic component blunted by both caspase-2 and caspase-3 inhibitors

The objective of this study was to evaluate the cardiac toxicity of the HMG-CoA reductase inhibitors by testing the hypothesis that lovastatin induces apoptotic and/or oncotic cell death in the myocyte element of the heart and further that cell death is mediated through interruption of the mevalonate pathway and that apoptosis is induced through activation of caspase-2 and caspase-3. Cardiomyocytes were cultured from embryonic chick heart. Lovastatin-induced apoptosis in these cells was demonstrated by three independent techniques, namely (1) FACS analysis of low DNA content by propidium iodide (PI); (2) microscopic assessment for cellular changes of apoptosis; and (3) FACS analysis of cells stained with PI and fluorescein diacetate. Lovastatin produced a concentration-dependent increase in apoptotic cell death and 100 microM lovastatin showed over a 4-fold increase in apoptosis compared to control. Lovastatin also induced oncotic cell death, as there was a 2.5-fold increase in the amount of oncotic cell death compared to control. Lovastatin-induced apoptosis operated, in part, through the mevalonate pathway. The caspase-2 inhibitor z-VDVAD-fmk and the caspase-3 inhibitor Ac-DEVD-CHO reduced the extent of lovastatin-induced cardiac apoptosis. In contrast, lovastatin-induced oncosis was not only insensitive to these caspase-2 or -3 inhibitors but occurred through a mevalonate-independent mechanism of action. In summary, lovastatin-induced cardiotoxicity is complex and represents the sum of two distinct modes of cell death operating in part through the mevalonate pathway with the apoptotic component subject to modification by inhibitors of the initiator caspase, caspase-2, as well as the effector caspase, caspase-3.     

重度眼球穿孔伤视网膜光感受细胞损伤的实验研究

目的 观察兔重度眼球穿孔伤视网膜光感受细胞胀亡(oncosis)情况和核糖核酸(RNA)的表达,以及两者在重度眼球损伤中的作用.方法 健康新西兰白兔制作重度眼球穿孔伤模型,用甲基绿-派罗宁-马休黄(MG-P-MY)染色法和超高倍镜分别观察细胞胀亡情况及进行细胞RNA检测.结果 对照组和1 h组未见胀亡细胞,3 h组出现胀亡细胞,6 h组胀亡细胞数达高峰,12 h组有所下降.3 h组在内核层及神经节细胞层有少量RNA阳性表达,6 h内核层阳性表达增多,12 h阳性表达明显,24 h可见大量RNA阳性细胞.结论 眼球枪弹穿孔伤后,胀亡是视网膜细胞死亡的另一种主要方式.在视网膜细胞死亡过程中,胀亡和凋亡是其主要死亡方式.     

胃癌组织中水通道蛋白1、微血管密度与细胞胀亡的关系及临床意义

目的：探讨胃癌组织中水通道蛋白1（AQP1）、微血管密度（MVD）与细胞胀亡的关系及临床意义。方法采用免疫组化法、蛋白印迹法检测55例胃癌、22例胃正常组织中AQP1的表达,Ⅷ因子相关抗原多克隆抗体标记血管内皮细胞法计数MVD,透射电镜观测细胞胀亡情况。随访并分析AQP1与胃癌患者预后的关系。结果胃癌组织中存在细胞胀亡;Ⅲ＋Ⅳ临床分期胃癌组织中的胀亡指数（OI）高于Ⅰ＋Ⅱ临床分期（P＜0.01）;淋巴结转移组OI明显高于无淋巴结转移组（P＜0.05）。AQP1表达强度与MVD呈显著正相关（P＜0.05）。在胃癌组织标本中,AQP1阳性表达率为58.2％,明显高于正常胃组织（P＜0.01）。胃癌伴淋巴结转移组AQP1表达水平明显高于无淋巴结转移组（P＜0.05）。多因素生存分析显示AQP1表达、有无淋巴结转移是预后的独立危险因素（P＜0.05）。结论细胞胀亡和AQP1表达与胃癌的血管生成、生物学行为密切相关;AQP1可以作为判断胃癌预后的临床指标。     

细胞胀亡的分子机制研究进展

Oncosis is another form of cell death, which is different from apoptosis. The review will discuss the recent advances of oncosis on pathological morphology, nuclear biochemical changes and molecular mechanisms.     

Persistent oxygen-glucose deprivation induces astrocytic death through two different pathways and calpain-mediated proteolysis of cytoskeletal proteins during astrocytic oncosis

Astrocytes are thought to play a role in the maintenance of homeostasis and the provision of metabolic substrates for neurons as well as the coupling of cerebral blood flow to neuronal activity. Accordingly, astrocytic death due to various types of injury can critically influence neuronal survival. The exact pathway of cell death after brain ischemia is under debate. In the present study, we used astrocytes from rat primary culture treated with persistent oxygen-glucose-deprivation (OGD) as a model of ischemia to examine the pathway of cell death and the relevant mechanisms. We observed changes in the cellular morphology, the energy metabolism of astrocytes, and the percentage of apoptosis or oncosis of the astrocytes induced by OGD. Electron microscopy revealed the co-existence of ultrastructural features in both apoptosis and oncosis in individual cells. The cellular ATP content was gradually decreased and the percentages of apoptotic and oncotic cells were increased during OGD. After 4 h of OGD, ATP depletion to less than 35% of the control was observed, and oncosis became the primary pathway for astrocytic death. Increased plasma membrane permeability due to oncosis was associated with increased calpain-mediated degradation of several cytoskeletal proteins, including paxillin, vinculin, vimentin and GFAP. Pre-treatment with the calpain inhibitor 3-(4-iodophenyl)-2-mercapto-(Z)-2-propenoic acid (PD150606) could delay the OGD-induced astrocytic oncosis. These results suggest that there is a narrow range of ATP that determines astrocytic oncotic death induced by persistent OGD and that calpain-mediated hydrolysis of the cytoskeletal-associated proteins may contribute to astrocytes oncosis.     

大剂量γ射线照射后PC12细胞死亡方式的研究

目的 研究受大剂量γ射线作用后,大鼠肾上腺嗜铬细胞瘤细胞（PC12）的死亡方式,寻找神经细胞辐射损伤的体外模型.方法 PC12细胞分为0、8、16和32 Gy组,经60 Co γ射线照射后,PI单染流式细胞术法观察细胞增殖周期改变,Annexin-V-FITC及PI双染法检测细胞凋亡的发生,光镜和电镜技术观察照射后细胞分化与存活的形态学变化.结果 大剂量γ射线照射后,随照射剂量的加大,发生死亡的细胞数有所增加,但发生凋亡的PC12细胞数目很少,可以忽略不计;细胞主要是在肿胀的基础上发生死亡的.电镜显示,细胞器明显肿胀扩张,粗面内质网高度扩张,线粒体肿胀、空化,核染色质浓缩成块状,散在于核膜下及核仁周围,核膜间隙增宽,与胀亡性坏死的特征相类似.结论 大剂量γ射线照射后,PC12细胞主要是在肿胀的基础上发生死亡的.该细胞模型适于被用来研究辐射致神经细胞坏死相关病理生理过程及其内在机制等问题.     

莪术油注射液致人卵巢癌SKOV3细胞胀亡形态变化研究

目的研究莪术油注射液对人卵巢癌SKOV3细胞形态学改变的影响。方法以不同的药物浓度作用人卵巢癌SKOV3细胞株后,采用光学显微镜和透射电镜观察卵巢癌SKOV3细胞形态学变化。结果光镜下可见莪术油低浓度组部分细胞体积开始变大,细胞胞浆空泡化,胞浆内出现致密颗粒,细胞核开始变形。细胞胞浆出现大面积的空泡,细胞核变形明显,细胞质出现颗粒脱落,出现细胞质空泡,核内染色质分散。高浓度组细胞肿胀,胞浆减少,核浆比例增加,细胞质大量颗粒脱落,细胞质空泡明显,有胞膜崩解、细胞核溶解;电镜下可见卵巢癌SKOV3细胞胀亡,且呈浓度依赖性。结论莪术油注射液诱导SKOV3细胞胀亡是其抑制肿瘤细胞生长的机制之一。     

结直肠癌细胞胀亡与肿瘤组织微血管密度的关系

目的探讨结直肠癌组织中细胞胀亡及其与微血管密度(microvesseldensity,MVD)的关系和临床意义。方法利用透射电镜和免疫组化技术对64例结直肠癌组织中细胞胀亡与MVD进行检测。结果结直肠癌组织中存在细胞胀亡;结直肠癌组织中胀亡指数(oncosisindex,OI)随分化程度降低而降低(F=85902,P<0005);淋巴结转移组OI明显低于无淋巴结转移组(t=20630,P<005);MVD在淋巴结转移组高表达,无淋巴结转移组低表达(t=32733,P<0005)。MVD高表达组的OI低于低表达组(t=24108,P<001)。结论细胞胀亡和MVD表达与结直肠癌的生物学行为密切相关。     

胃腺癌TSP-1的表达与细胞胀亡的关系及意义

目的：探讨胃腺癌组织中凝血酶敏感蛋白-1（TSP-1）的表达与细胞胀亡的关系及意义。方法：利用免疫组织化学方法检测57例胄腺癌组织中TSP-1的表达，利用透射电镜技术观察其中肿瘤细胞的胀亡情况，分析两者的相关性。结果：TSP-1的阳性表达率与肿瘤的淋巴结转移密切相关（P〈0．01）。TSP-1表达阳性的肿瘤细胞较多发生胀亡，胃腺癌组织中TSP-1的表达与胀亡细胞的发生呈正相关（r=0．679，P〈0．01）。胀亡指数（OI）与肿瘤的分化程度、淋巴结转移密切相关（P〈0．01，P〈0．05）。结论：TSP-1表达和细胞胀亡与胃腺癌生物学行为密切相关。