蟾蜍灵诱导人宫颈癌C33A细胞自噬作用的机理研究

目的:探讨蟾蜍灵诱导人宫颈癌C33A细胞自噬的作用。方法:不同浓度梯度的蟾蜍灵处理人宫颈癌C33A细胞，选用CCK－8法检测蟾蜍灵对人宫颈癌C33A细胞的杀伤作用。透射电镜观察给药后C33A细胞的自噬现象。流式细胞仪检测细胞内活性氧（ROS）水平，蛋白免疫印迹法检测自噬LC3蛋白表达及相关信号通路JNK、p-JNK蛋白表达。结果:蟾蜍灵对人宫颈癌C33A细胞的生长抑制作用呈时间-剂量依赖性。蟾蜍灵给药后可诱导C33A细胞发生自噬，蛋白印迹实验结果表明LC3蛋白表达随药物浓度升高而增加。蟾蜍灵诱导C33A细胞自噬发生与其促ROS水平升高激活了JNK信号通路有关。结论:蟾蜍灵诱导C33A细胞自噬的机制可能与通过ROS/JNK通路促进细胞自噬有关，以此发挥其抗肿瘤的作用。     

银杏内酯B对肌萎缩侧索硬化细胞模型的保护作用及其机制

目的:探讨银杏内酯B(ginkgolide B,GB)对肌萎缩侧索硬化细胞模型c-Jun氨基末端激酶(JNK)信号通路及细胞凋亡的影响。方法:通过含过表达人突变超氧化物歧化酶1(SOD1)~(G93A)基因(hSOD1~(G93A))和过表达人野生SODWT基因(hSOD1WT)与空质粒的慢病毒感染NSC34细胞,经一定浓度的嘌呤霉素筛选,倒置荧光显微镜下观察慢病毒的转染效率和细胞形态的变化,蛋白免疫印迹法(Western blot)检验感染细胞是否过表达SOD1蛋白,建立hSOD1~(G93A)-NSC34细胞系后给予GB,细胞培养分组为正常组、模型组、不同浓度GB组(25,50,75,100 mg·L-1)组,48 h后噻唑蓝(MTT)比色法检测细胞存活率,筛选出最佳药物浓度,后续实验分组为以正常组,模型组,75 mg?L~(-1) GB组,SP600125组,75 mg?L-1GB+SP600125组,流式细胞术检测各组细胞的凋亡率,蛋白免疫印迹法(Western blot)检测磷酸化(p-)JNK,c-Jun,p-c-Jun,半胱氨酸天冬氨酸蛋白酶-3(Caspase-3)蛋白的表达。结果:与正常的NSC34细胞比较,hSOD1~(G93A)NSC34组细胞胞体变圆,突触减少、变短,而hSOD1WT NSC34组细胞和空质粒组细胞形态学未发生明显变化,与正常组比较,hSOD1~(G93A)NSC34组,hSOD1WTNSC3组细胞内SOD1蛋白水平显著升高(P0. 01),肌萎缩侧索硬化(ALS)细胞模型成功建立。与正常组比较,模型组细胞存活率显著降低(P0. 01);与模型组比较,给予不同浓度GB后,细胞存活率均显著升高(P0. 01),药物质量浓度为75 mg?L-1时细胞存活率显著升高(P0. 01)。后续实验,与正常组比较,模型组凋亡率,p-JNK,p-c-Jun,cleaved Caspase-3蛋白表达量显著升高(P0. 01);与模型组比较,75 mg?L-1GB组,SP600125组,75 mg?L-1GB+SP600125组凋亡率,p-JNK,p-c-Jun,cleaved Caspase-3蛋白表达明显降低(P0. 05,P0. 01)。结论:GB对肌萎缩侧索硬化细胞模型具有抑制细胞凋亡的保护作用,这种保护作用可能是通过JNK信号通路实现的。     

Knockdown of Long Noncoding RNA CAT104 Inhibits the Proliferation,Migration, and Invasion of Human Osteosarcoma Cells by Regulating MicroRNA-381

Osteosarcoma is the most common primary malignant bone tumor in children and adolescents. This study aimed to explore the effects of long noncoding RNA CAT104 and microRNA-381 (miR-381) on osteosarcoma cell proliferation, migration, invasion, and apoptosis, as well as the underlying potential mechanism. We found that CAT104 was highly expressed in osteosarcoma MG63 and OS-732 cells. Knockdown of CAT104 significantly inhibited OS-732 cell proliferation, migration, and invasion, but promoted cell apoptosis. CAT104 regulated the expression of miR-381, and miR-381 participated in the effects of CAT104 on OS-732 cells. Zinc finger E-box-binding homeobox 1 (ZEB1) was a direct target gene of miR-381, which was involved in the regulatory roles of miR-381 in OS-732 cell proliferation, migration, invasion, and apoptosis, as well as c-Jun N-terminal kinase (JNK) and Wnt/ -catenin pathways. In conclusion, our research verified that suppression of CAT104 exerted significant inhibitory effects on osteosarcoma cell proliferation, migration, and invasion by regulating the expression of miR-381 and downstream ZEB1, as well as JNK and Wnt/ -catenin pathways.     

Loss of GRB2 associated binding protein 1 in arteriosclerosis obliterans promotes host autophagy

Background:Arteriosclerosis obliterans (ASO) is a major cause of adult limb loss worldwide. Autophagy of vascular endothelial cell (VEC) contributes to the ASO progression. However, the molecular mechanism that controls VEC autophagy remains unclear. In this study, we aimed to explore the role of the GRB2 associated binding protein 1 (GAB1) in regulating VEC autophagy.Methods:In vivo and in vitro studies were applied to determine the loss of adapt protein GAB1 in association with ASO progression. Histological GAB1 expression was measured in sclerotic vascular intima and normal vascular intima. Gain- and loss-of-function of GAB1 were applied in VEC to determine the effect and potential downstream signaling of GAB1.Results:The autophagy repressor p62 was significantly downregulated in ASO intima as compared to that in healthy donor (0.80 vs. 0.20, t = 6.43, P < 0.05). The expression level of GAB1 mRNA (1.00 vs. 0.24, t = 7.41, P < 0.05) and protein (0.72 vs. 0.21, t = 5.97, P < 0.05) was significantly decreased in ASO group as compared with the control group. Loss of GAB1 led to a remarkable decrease in LC3II (1.19 vs. 0.68, t = 5.99, P < 0.05), whereas overexpression of GAB1 significantly led to a decrease in LC3II level (0.41 vs. 0.93, t = 7.12, P < 0.05). Phosphorylation levels of JNK and p38 were significantly associated with gain- and loss-of-function of GAB1 protein.Conclusion:Loss of GAB1 promotes VEC autophagy which is associated with ASO. GAB1 and its downstream signaling might be potential therapeutic targets for ASO treatment.     

Mechanistic perspective of protective effects of nilotinib against cisplatin-induced testicular injury in rats: Role of JNK/caspase-3 signaling inhibition

Cisplatin is an effective anticancer used widely in treatment of solid and germ cell tumors, however, the immense toxicity on healthy tissues discourages cisplatin use in prolonged treatment protocols. Testicular toxicity is amongst its undesired adverse effects. Nilotinib is a second generation multityrosine kinase inhibitor which is used as an anticancer agent with anti-inflammatory and antioxidant activities. In the present study, a single dose of cisplatin (7 mg/kg, I.P) to rats induced a significant testicular injury. Daily administration of nilotinib (20 mg/kg, orally) 24 h post cisplatin injection for 10 days ameliorated testicular damage. Nilotinib significantly increased serum testosterone and sperm concentration outside frame of oligospermia with simultaneous full recovery of sperm viability. Nevertheless, biomarkers of apoptosis such as JNKs and Caspase -3, were significantly reduced. Moreover, improved antioxidant status of the testes was inferred by significant elevation of GSR, SOD and TAC alongside with reduction in lipid peroxidation biomarkers; MDA and 4-HNE. Flow Cytometry analysis of the cell cycle confirmed a significant increase in the percentage of testicular cells present in G2/M phase and a significant decrease in the percentage of apoptotic testicular cells after nilotinib administration. Histopathologically, nilotinib preserved testicular architecture showing significant numbers of sperm and spermatids within lumens of seminiferous tubule. Furthermore, nilotinib enhanced testicular expression of Ki67 significantly, providing evidence of testicular regeneration. In conclusion, nilotinib refinement of cisplatin induced testicular toxicity is attributed to enhancing antioxidant capabilities, decreasing apoptotic signals and restoring regenerative capacity of testes suggesting nilotinib to be used in conjunction with cisplatin in treatment protocols to avoid cisplatin induced long term testicular toxicity.     

PRKAA1 Promotes Proliferation and Inhibits Apoptosis of Gastric Cancer Cells Through Activating JNK1 and Akt Pathways

PRKAA1 (protein kinase AMP-activated catalytic subunit 1) is a catalytic subunit of AMP-activated protein kinase (AMPK), which plays a key role in regulating cellular energy metabolism through phosphorylation, and genetic variations in the PRKAA1 have been found to be associated with gastric cancer risk. However, the effect and underlying molecular mechanism of PRKAA1 on gastric cancer tumorigenesis, especially the proliferation and apoptosis, are not fully understood. Our data showed that PRKAA1 is highly expressed in BGC- 823 and MKN45 cells and is expressed low in SGC-7901 and MGC-803 cells in comparison with the other gastric cancer cells. PRKAA1 downregulation by shRNA or treatment of AMPK inhibitor compound C significantly inhibited proliferation as well as promoted cell cycle arrest and apoptosis of BGC-823 and MKN45 cells. Moreover, the expression of PCNA and Bcl-2 and the activity of JNK1 and Akt signaling were also reduced in BGC-823 and MKN45 cells after PRKAA1 downregulation. In vivo experiments demonstrated that tumor growth in nude mice was significantly inhibited after PRKAA1 silencing. Importantly, inactivation of JNK1 or Akt signaling pathway significantly inhibited PRKAA1 overexpression-induced increased cell proliferation and decreased cell apoptosis in MGC-803 cells. In conclusion, our findings suggest that PRKAA1 increases proliferation and restrains apoptosis of gastric cancer cells through activating JNK1 and Akt pathways.     

Mutations in the transcription factor FOXO1 mimic positive selection signals to promote germinal center B cell expansion and lymphomagenesis

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黄芪多糖通过抑制NF-κB和JNK信号通路减轻LPS诱导的小鼠心肌细胞凋亡

目的研究黄芪多糖(Astragalus polysaccharide,APS)对脂多糖(lipopolysaccharide,LPS)诱导的小鼠心肌细胞凋亡的影响,并探讨其作用机制。方法体外实验采用H9c2细胞预先给予APS,30 min后加入LPS(1 mg·L^-1)共孵育24 h,建立心肌细胞凋亡模型。体内实验采用SPF级昆明小鼠预防性给予APS 14 d后,腹腔注射LPS(10 mg·kg^-1)建立心肌细胞凋亡模型。8 h后采用超声心动测定小鼠心脏射血分数(EF)、左心室缩短分数(FS)等;TUNEL测心肌细胞凋亡;ELISA检测血清中IL^-1β、TNF-α含量;Western blot检测组织和体外心肌细胞中JNK、NF-κB信号通路及Bcl-2家族、caspase-3相关蛋白表达。结果 LPS能明显抑制小鼠的左心室收缩功能;促使心肌细胞凋亡;增加血清中IL^-1β、TNF-α,心肌细胞中JNK、p-JNK、Bax、caspase-3,胞核中NF-κB蛋白浓度;降低Bcl-2和胞质中NF-κB、IκB-α蛋白浓度。APS能明显保护LPS诱导的小鼠心肌收缩功能,减少心肌细胞凋亡;减少血清中IL^-1β、TNF-α,心肌组织细胞中p-JNK、Bax、caspase-3和胞核NF-κB蛋白含量;相对增加Bcl-2和胞质中NF-κB、IκB-α蛋白含量。而JNK蛋白表达无明显变化。结论 APS通过抑制NF-κB和JNK信号通路,减轻LPS诱导的小鼠心肌细胞凋亡。