AIM: To study the antitumor effect of matrine in human hepatoma G2 (HepG2) cells and its molecular mechanism involved in antineoplastic activities. METHODS: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide...AIM: To study the antitumor effect of matrine in human hepatoma G2 (HepG2) cells and its molecular mechanism involved in antineoplastic activities. METHODS: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to detect viability of HepG2 cells. The effect of matrine on cell cycle was detected by flow cytometry. Annexin-V-FITC/PI double staining assay was used to detect cellular apoptosis. Cellular morphological changes were observed under an inverted phase contrast microscope. Transmission electron microscopy was performed to further examine ultrastructural structure of the cells treatedwith matrine. Monodansylcadaverine (MDC) staining was used to detect autophagy. Whether autophagy is blocked by 3-methyladenine (3-MA), an autophagy inhibitor, was evaluated. Expression levels of Bax and Beclin 1 in HepG2 cells were measured by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR).RESULTS: Matrine signif icantly inhibited the proliferation of HepG2 cells in a dose- and time-dependent manner, and induced G1-phase cell cycle arrest and apoptosis of HepG2 cells in a dose-dependent manner. The total apoptosis rate was 0.14% for HepG2 cells not treated with matrine. In contrast, the apoptosis rate was 28.91%, 34.36% and 38.80%, respectively, for HepG2 cells treated with matrine at the concentration of 0.5, 1.0 and 2.0 mg/mL. The remarkable morphological changes were observed under an inverted phase contrast microscope. Abundant cytoplasmic vacuoles with varying sizes were observed in HepG2 cells treated with matrine. Furthermore, vacuolization in cytoplasm progressively became larger and denser when the concentration of matrine was increased. Electron microscopy demonstrated formation of abundant autophagic vacuoles in HepG2 cells after matrine treatment. When the specif ic autophagic inhibitor, 3-MA, was applied, the number of autophagic vacuoles greatly decreased. MDC staining showed that the fluorescent density was higher and the number of MDC-labeled particles展开更多
Electroacupuncture is known as an effective adjuvant therapy in ischemic cerebrovascular disease. However, its underlying mechanisms remain unclear. Studies suggest that autophagy, which is essential for cell survival...Electroacupuncture is known as an effective adjuvant therapy in ischemic cerebrovascular disease. However, its underlying mechanisms remain unclear. Studies suggest that autophagy, which is essential for cell survival and cell death, is involved in cerebral ischemia reperfusion injury and might be modulate by electroacupuncture therapy in key ways. This paper aims to provide novel insights into a therapeutic target of electroacupuncture against cerebral ischemia/reperfusion injury from the perspective of autophagy. Here we review recent studies on electroacupuncture regulation of autophagy-related markers such as UNC-51-like kinase-1 complex, Beclin1, microtubule-associated protein-1 light chain 3, p62, and autophagosomes for treating cerebral ischemia/reperfusion injury. The results of these studies show that electroacupuncture may affect the initiation of autophagy, vesicle nucleation, expansion and maturation of autophagosomes, as well as fusion and degradation of autophagolysosomes. Moreover, studies indicate that electroacupuncture probably modulates autophagy by activating the mammalian target of the rapamycin signaling pathway.This review thus indicates that autophagy is a therapeutic target of electroacupuncture treatment against ischemic cerebrovascular diseases.展开更多
Recent advances in the understanding of the molecular processes contributing to autophagy have provided insight into the relationship between autophagy and apoptosis.In contrast to the concept of“autophagic cell dea...Recent advances in the understanding of the molecular processes contributing to autophagy have provided insight into the relationship between autophagy and apoptosis.In contrast to the concept of“autophagic cell death,”accumulating evidence suggests that autophagy serves a largely cytoprotective role in physiologically relevant conditions.The cytoprotective function of autophagy is mediated in many circumstances by negative modulation of apoptosis.Apoptotic signaling,in turn,serves to inhibit autophagy.While the mechanisms mediating the complex counter-regulation of apoptosis and autophagy are not yet fully understood,important points of crosstalk include the interactions between Beclin-1 and Bcl-2/Bcl-xL and between FADD and Atg5,caspase-and calpain-mediated cleavage of autophagy-related proteins,and autophagic degradation of caspases.Continued investigation of these and other means of crosstalk between apoptosis and autophagy is necessary to elucidate the mechanisms controlling the balance between survival and death both under normal conditions and in diseases including cancer.展开更多
基金Supported by National Natural Science Foundation of China, No. 30870364Science and Technology Support Program of Gansu Province, China, No. 0708NKCA129
文摘AIM: To study the antitumor effect of matrine in human hepatoma G2 (HepG2) cells and its molecular mechanism involved in antineoplastic activities. METHODS: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to detect viability of HepG2 cells. The effect of matrine on cell cycle was detected by flow cytometry. Annexin-V-FITC/PI double staining assay was used to detect cellular apoptosis. Cellular morphological changes were observed under an inverted phase contrast microscope. Transmission electron microscopy was performed to further examine ultrastructural structure of the cells treatedwith matrine. Monodansylcadaverine (MDC) staining was used to detect autophagy. Whether autophagy is blocked by 3-methyladenine (3-MA), an autophagy inhibitor, was evaluated. Expression levels of Bax and Beclin 1 in HepG2 cells were measured by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR).RESULTS: Matrine signif icantly inhibited the proliferation of HepG2 cells in a dose- and time-dependent manner, and induced G1-phase cell cycle arrest and apoptosis of HepG2 cells in a dose-dependent manner. The total apoptosis rate was 0.14% for HepG2 cells not treated with matrine. In contrast, the apoptosis rate was 28.91%, 34.36% and 38.80%, respectively, for HepG2 cells treated with matrine at the concentration of 0.5, 1.0 and 2.0 mg/mL. The remarkable morphological changes were observed under an inverted phase contrast microscope. Abundant cytoplasmic vacuoles with varying sizes were observed in HepG2 cells treated with matrine. Furthermore, vacuolization in cytoplasm progressively became larger and denser when the concentration of matrine was increased. Electron microscopy demonstrated formation of abundant autophagic vacuoles in HepG2 cells after matrine treatment. When the specif ic autophagic inhibitor, 3-MA, was applied, the number of autophagic vacuoles greatly decreased. MDC staining showed that the fluorescent density was higher and the number of MDC-labeled particles
文摘Electroacupuncture is known as an effective adjuvant therapy in ischemic cerebrovascular disease. However, its underlying mechanisms remain unclear. Studies suggest that autophagy, which is essential for cell survival and cell death, is involved in cerebral ischemia reperfusion injury and might be modulate by electroacupuncture therapy in key ways. This paper aims to provide novel insights into a therapeutic target of electroacupuncture against cerebral ischemia/reperfusion injury from the perspective of autophagy. Here we review recent studies on electroacupuncture regulation of autophagy-related markers such as UNC-51-like kinase-1 complex, Beclin1, microtubule-associated protein-1 light chain 3, p62, and autophagosomes for treating cerebral ischemia/reperfusion injury. The results of these studies show that electroacupuncture may affect the initiation of autophagy, vesicle nucleation, expansion and maturation of autophagosomes, as well as fusion and degradation of autophagolysosomes. Moreover, studies indicate that electroacupuncture probably modulates autophagy by activating the mammalian target of the rapamycin signaling pathway.This review thus indicates that autophagy is a therapeutic target of electroacupuncture treatment against ischemic cerebrovascular diseases.
文摘Recent advances in the understanding of the molecular processes contributing to autophagy have provided insight into the relationship between autophagy and apoptosis.In contrast to the concept of“autophagic cell death,”accumulating evidence suggests that autophagy serves a largely cytoprotective role in physiologically relevant conditions.The cytoprotective function of autophagy is mediated in many circumstances by negative modulation of apoptosis.Apoptotic signaling,in turn,serves to inhibit autophagy.While the mechanisms mediating the complex counter-regulation of apoptosis and autophagy are not yet fully understood,important points of crosstalk include the interactions between Beclin-1 and Bcl-2/Bcl-xL and between FADD and Atg5,caspase-and calpain-mediated cleavage of autophagy-related proteins,and autophagic degradation of caspases.Continued investigation of these and other means of crosstalk between apoptosis and autophagy is necessary to elucidate the mechanisms controlling the balance between survival and death both under normal conditions and in diseases including cancer.
文摘目的探讨加味丹参饮预处理是否通过调节Beclin-1和Atg5表达调控自噬抗缺血再灌注损伤大鼠心肌。方法将60只健康SD大鼠随机分为空白对照(control group,C)组、假手术(sham,S)组、缺血再灌注损伤(ischemia reperfusion injury,IRI)组、IRI+加味丹参饮(Jiawei Danshen Yin,JDY)组、IRI+JDY+自噬抑制剂(inhibitor,I)组,每组12只。通过结扎-放松大鼠左冠状动脉前降支制备心肌IRI模型。通过氯化三苯基四氮唑(TTC)染色观察心肌梗死面积率;在透射电镜下观察自噬泡;采用实时荧光定量逆转录-聚合酶链反应(reverse transcription-polymerase chain reaction,RT-PCR)方法检测心肌Beclin-1和Atg5 m RNA表达;采用蛋白质印迹(western blot)法检测心肌Beclin-1蛋白表达变化。结果 IRI+JDY组心肌梗死面积率显著低于IRI组及IRI+JDY+I组(P<0.01)。电镜结果显示,IRI+JDY组适度调节大鼠缺血再灌注损伤心肌细胞的自噬,改善心肌细胞结构。IRI组大鼠心肌细胞中Beclin-1和Atg5 m RNA表达水平及Beclin-1蛋白表达较SG组显著升高(P<0.01);IRI+JDY组、IRI+JDY+I组大鼠心肌细胞中Beclin-1和Atg5 m RNA表达水平及Beclin-1蛋白表达较IRI组显著降低(P<0.01);IRI+JDY组大鼠心肌细胞中Beclin-1和Atg5 m RNA表达水平及Beclin-1蛋白表达较IRI+JDY+I组显著升高(P<0.01)。结论加味丹参饮通过调节缺血再灌注损伤大鼠心肌细胞自噬相关基因Beclin-1和Atg5表达适度,调控缺血再灌注心肌细胞发生适度自噬,从而发挥细胞保护作用。
