目的自噬是细胞在不良环境中自我吞噬的生物学现象,在恶性肿瘤发病机制中具有重要作用,缺氧是诱导细胞自噬的重要因素。本研究探讨不同氧环境中卵巢癌HO-8910细胞let-7a的表达变化及对缺氧细胞自噬、增殖的影响。方法实验分常氧组、缺...目的自噬是细胞在不良环境中自我吞噬的生物学现象,在恶性肿瘤发病机制中具有重要作用,缺氧是诱导细胞自噬的重要因素。本研究探讨不同氧环境中卵巢癌HO-8910细胞let-7a的表达变化及对缺氧细胞自噬、增殖的影响。方法实验分常氧组、缺氧组、缺氧+miR-NC-mimics组和缺氧+let-7a-mimics组4组,各组细胞经处理48h后:吖啶橙染色观察细胞自噬发生情况;MTT法分析细胞增殖变化,流式细胞术检测细胞周期分布;Real time PCR分析let-7a、Beclin-1和LC3-Ⅱ的表达变化,蛋白质印迹试验分析Beclin-1和LC3-Ⅱ蛋白表达变化。结果 HO-8910细胞经缺氧处理后自噬率显著增高至(34.46±5.13)%,F=49.932,P=0.002;在缺氧基础上转染miR-NC-mimics后,自噬率变化不大,F=0.110,P=0.756;而转染let-7a-mimics后,细胞自噬率显著降低至(4.56±2.04)%,F=68.186,P<0.001。缺氧使G0/G1期细胞数量明显增至(70.43±3.19)%,F=23.216,P=0.008;同时转染miR-NC-mimics后,其数量变化差异无统计学意义,F=0.467,P=0.532;而在缺氧条件下转染let-7a-mimics,其数量则增至(82.37±3.45)%,F=67.423,P=0.001;并伴随细胞增殖抑制率显著上升,F=24.602,P=0.007。缺氧条件下以及缺氧同时转染miR-NC-mimics后,let-7a表达下调,而Beclin-1、LC3-Ⅱ表达上调;而在缺氧基础上转染let-7a-mimics后,let-7a表达明显增强,F=295.623,P<0.001;Beclin-1蛋白表达下调,F=33.285,P=0.002;LC3-Ⅱ也明显下调,F=41.969,P=0.001。结论卵巢癌HO-8910细胞在缺氧状态时,let-7a表达下调,细胞启动适度自噬保护机制,介导细胞逃避缺氧环境使细胞继续快速生长,当上调let-7a表达后,缺氧所致的适度自噬保护作用被消减,细胞增殖明显受抑。展开更多
AIM: To investigate the protective effect of isoflurane on energy balance in isolated hepatocytes during in vitro anoxia/reoxygenation, and to compare isoflurane with halothane. METHODS: Hepatocytes freshly isolated f...AIM: To investigate the protective effect of isoflurane on energy balance in isolated hepatocytes during in vitro anoxia/reoxygenation, and to compare isoflurane with halothane. METHODS: Hepatocytes freshly isolated from fed rats were suspended in Krebs-Henseleit buffer, and incubated in sealed flasks under O2/CO2 or N2/CO2 (95%/5%, V/V) for 30 or 60 min, followed by 5 or 10 min of reoxygenation, with an added volatile anesthetic or not. ATP, ADP, and adenosine monophosphate in hepatocytes were determined by high performance liquid chromatography, and energy charge was calculated. RESULTS: During 30 min of anoxia, the energy charge and total adenine nudeotide steadily increased with the isoflurane dose from 0 to 2 minimum alveolar anesthetic concentration (MAC), then decreased from 2 to 3 MAC. In short incubations (30-35 min) at 1 MAC isoflurane, energy charge modestly decreased during anoxia, which was partially prevented by isoflurane and completely reversed by reoxygenation, and total adenine nudeotide did not decrease. In long incubations (60-70 min), both energy charge and total adenine nudeotide greatly decreased during anoxia, with partial and no reversal by reoxygenation, respectively. Isoflurane partly prevented decreases in both energy charge and total adenine nudeotide during anoxia and reoxygenation. In addition, 1 MAC isoflurane obviously increased ATP/ADP, which could not be changed by 1 MAC halothane. CONCLUSION: Isoflurane partially protects isolated hepatocytes against decreases in both energy charge and total adenine nudeotide during short (reversible) or long (irreversible) anoxia.展开更多
文摘目的自噬是细胞在不良环境中自我吞噬的生物学现象,在恶性肿瘤发病机制中具有重要作用,缺氧是诱导细胞自噬的重要因素。本研究探讨不同氧环境中卵巢癌HO-8910细胞let-7a的表达变化及对缺氧细胞自噬、增殖的影响。方法实验分常氧组、缺氧组、缺氧+miR-NC-mimics组和缺氧+let-7a-mimics组4组,各组细胞经处理48h后:吖啶橙染色观察细胞自噬发生情况;MTT法分析细胞增殖变化,流式细胞术检测细胞周期分布;Real time PCR分析let-7a、Beclin-1和LC3-Ⅱ的表达变化,蛋白质印迹试验分析Beclin-1和LC3-Ⅱ蛋白表达变化。结果 HO-8910细胞经缺氧处理后自噬率显著增高至(34.46±5.13)%,F=49.932,P=0.002;在缺氧基础上转染miR-NC-mimics后,自噬率变化不大,F=0.110,P=0.756;而转染let-7a-mimics后,细胞自噬率显著降低至(4.56±2.04)%,F=68.186,P<0.001。缺氧使G0/G1期细胞数量明显增至(70.43±3.19)%,F=23.216,P=0.008;同时转染miR-NC-mimics后,其数量变化差异无统计学意义,F=0.467,P=0.532;而在缺氧条件下转染let-7a-mimics,其数量则增至(82.37±3.45)%,F=67.423,P=0.001;并伴随细胞增殖抑制率显著上升,F=24.602,P=0.007。缺氧条件下以及缺氧同时转染miR-NC-mimics后,let-7a表达下调,而Beclin-1、LC3-Ⅱ表达上调;而在缺氧基础上转染let-7a-mimics后,let-7a表达明显增强,F=295.623,P<0.001;Beclin-1蛋白表达下调,F=33.285,P=0.002;LC3-Ⅱ也明显下调,F=41.969,P=0.001。结论卵巢癌HO-8910细胞在缺氧状态时,let-7a表达下调,细胞启动适度自噬保护机制,介导细胞逃避缺氧环境使细胞继续快速生长,当上调let-7a表达后,缺氧所致的适度自噬保护作用被消减,细胞增殖明显受抑。
基金Supported by the National Natural Science Foundation of China, No. 39900140
文摘AIM: To investigate the protective effect of isoflurane on energy balance in isolated hepatocytes during in vitro anoxia/reoxygenation, and to compare isoflurane with halothane. METHODS: Hepatocytes freshly isolated from fed rats were suspended in Krebs-Henseleit buffer, and incubated in sealed flasks under O2/CO2 or N2/CO2 (95%/5%, V/V) for 30 or 60 min, followed by 5 or 10 min of reoxygenation, with an added volatile anesthetic or not. ATP, ADP, and adenosine monophosphate in hepatocytes were determined by high performance liquid chromatography, and energy charge was calculated. RESULTS: During 30 min of anoxia, the energy charge and total adenine nudeotide steadily increased with the isoflurane dose from 0 to 2 minimum alveolar anesthetic concentration (MAC), then decreased from 2 to 3 MAC. In short incubations (30-35 min) at 1 MAC isoflurane, energy charge modestly decreased during anoxia, which was partially prevented by isoflurane and completely reversed by reoxygenation, and total adenine nudeotide did not decrease. In long incubations (60-70 min), both energy charge and total adenine nudeotide greatly decreased during anoxia, with partial and no reversal by reoxygenation, respectively. Isoflurane partly prevented decreases in both energy charge and total adenine nudeotide during anoxia and reoxygenation. In addition, 1 MAC isoflurane obviously increased ATP/ADP, which could not be changed by 1 MAC halothane. CONCLUSION: Isoflurane partially protects isolated hepatocytes against decreases in both energy charge and total adenine nudeotide during short (reversible) or long (irreversible) anoxia.
