3,4,5-三羟基苯甲酸通过线粒体途径诱导人肝癌细胞SMMC-7721的凋亡

采用四甲基偶氮唑盐(MTT)观察3,4,5-三羟基苯甲酸(TBA)对人肝癌SMMC-7721细胞的增殖抑制作用; 通过流式细胞仪检测细胞凋亡、细胞内活性氧(ROS)及线粒体膜电位的变化, 用比色法测定Caspase-9和Caspase-3蛋白活性, 探讨TBA 诱导SMMC-7721细胞凋亡的分子机制. 研究结果表明, TBA对SMMC-7721细胞生长具有显著的抑制作用并诱导其凋亡, 诱导SMMC-7721细胞凋亡作用可能通过线粒体信号传导通路实现.     

Opsin3 Downregulation Induces Apoptosis of Human Epidermal Melanocytes via Mitochondrial Pathway

G protein-coupled receptors (GPCRs) are core switches connecting excellular survival or death signals with cellular signaling pathways in a context-dependent manner. Opsin 3 (OPN3) belongs to the GPCR superfamily. However, whether OPN3 can control the survival or death of human melanocytes is not known. Here, we try to investigate the inherent function of OPN3 on the survival of melanocytes. Our results demonstrate that OPN3 knockdown by RNAi-OPN3 in human epidermal melanocytes leads to cell apoptosis. The downregulation of OPN3 markedly reduces intracellular calcium levels and decreases phosphorylation of BAD. Attenuated BAD phosphorylation and elevated BAD protein level alter mitochondria membrane permeability, which trigger activation of BAX and inhibition of BCL-2 and raf-1. Activated BAX results in the release of cytochrome c and the loss of mitochondrial membrane potential. Cytochrome c complexes associate with caspase 9, forming a postmitochondrial apoptosome that activate effector caspases including caspase 3 and caspase 7. The release of apoptotic molecules eventually promotes the occurrence of apoptosis. In conclusion, we hereby are the first to prove that OPN3 is a key signal responsible for cell survival through a calcium-dependent G protein-coupled signaling and mitochondrial pathway.     

光激发纳米TiO2对胃癌SGC-7901细胞的杀伤作用

探讨了光激发纳米TiO2对胃癌SGC-7901细胞的杀伤作用, 考察了在不同纳米TiO2浓度及不同光照时间下纳米TiO2的抑瘤效果, 并探讨了抑瘤机制. 结果表明, 光激发纳米TiO2对胃癌SGC-7901细胞具有明显的抑制作用, 其过程类似一级反应的动力学规律; 当纳米TiO2浓度为300 μg/mL时, 对胃癌SGC-7901细胞表现出较强的杀伤效果, 其主要表现形式有两种, 即细胞坏死和细胞凋亡, 是由光激发条件下, 纳米TiO2表面产生的活性氧组分对肿瘤细胞的有效杀伤所致.     

Apoptosis Mechanism of Human Cholangiocarcinoma Cells Induced by Bile Extract from Crocodile

Animal bile is popularly used as a traditional medicine in China, and bile acids are their major bioactive constituents. In the present study, effects of bile extract from crocodile gallbladder on QBC939 cell growth, cell cycle, and apoptosis were investigated by MTT assay, inverted microscopy, fluorescence microscopy, transmission electron microscopy, scanning electron microscopy, PI single- and FITC/PI double-staining flow cytometry, and western blotting. Our data have revealed that bile extract inhibited cells growth significantly, and the cell cycle was arrested in G1 phase. Bile extract induced QBC939 cell apoptosis, which was associated with collapse of the mitochondrial membrane potential and increase of ROS. In bile extract-treated cells, it was observed that the expression of bcl-2 decreased and cytochrome c released to cytosol, but the expression of bax remained unchanged. The data indicated that mitochondrial pathway might play an important role in bile extract-induced apoptosis in QBC939 cells. These results provide significant insight into the anticarcinogenic action of bile extract on cholangiocarcinoma cells.     

Induction of Apoptosis by Ethanolic Extract of <em>Corchorus olitorius </em>Leaf in Human Hepatocellular Carcinoma (HepG2) Cells via a Mitochondria-Dependent Pathway

Corchorus olitorius L., is a culinary and medicinal herb, widely used as a vegetable in several countries in Asia. Many studies have shown that C. olitorius contains several antioxidants and exhibits anti-inflammatory and anti-proliferative activities in various in vitro and in vivo settings. Recently, C. olitorius has been approved for its antitumor activity; however, the underlying molecular mechanisms remain unclear. The goal of this study was to investigate the effects of ethanol extract of C. olitorius (ECO) on the growth of human hepatocellular carcinoma (HepG2) cells and gain some insights into the underlying mechanisms of its action. We found that HepG2 cells, treated with ECO for 24 h at a concentration higher than 12.5 μg/mL, displayed a strong reduction in cell viability, whereas normal FL83B hepatocytes were not affected. DNA fragmentation and nuclear condensation were evidenced by the increased subG1 population of ECO-treated HepG2 cells. ECO triggered the activation of procaspases-3 and -9 and caused the cleavage of downstream substrate, poly ADP-ribose polymerase (PARP), followed by down-regulation of the inhibitor of caspase-activated DNase (ICAD) signaling. Moreover, the increased release of cytochrome c from mitochondria with decreased membrane potential demonstrated the apoptosis induced through the caspases cascade. Our findings indicated that ECO might be effective against hepatocellular carcinoma through induction of apoptosis via mitochondria-dependent pathway.     

Synthesis of Isomeric Dimers of Deoxycholic Acid Derivatives Linked by 1,2,3-Triazole

Steroidal propargylic ester 6 and the propiolic ester 7 were prepared in a few steps from the deoxycholic acid. The Huisgen cycloaddition reaction of alkynes 6 and 7 as dipolarophiles with a 1,3-dipolar compound, the azide 5, afforded the dimeric compounds 8 and 9, respectively, in good yield. The dimers of deoxycholic acid derivatives linked by 1,4-disubstituted 1,2,3-triazole were characterized by spectroscopic methods.     

脱氧胆酸类分子钳对氨基酸甲酯的手性识别

紫外光谱法;脱氧胆酸类分子钳对氨基酸甲酯的手性识别     

Apoptosis Induced by Aqueous Extracts of Crocodile Bile in Human Heptacarcinoma SMMC-7721

In the present study, effects of aqueous extracts from Crocodylus siamensis bile (AE-CB) on SMMC-7721 cell growth, cell cycle, and apoptosis were investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay, inverted microscopy, fluorescence microscopy, propidium iodide (PI) single- and fluorescein isothiocyanate (FITC)/PI double-staining flow cytometry, and western blotting. Our data have revealed that AE-CB significantly inhibited the growth of SMMC-7721 cell and arrested cell cycle at G0/G1 phase. SMMC-7721 cells showed typical apoptotic morphological changes after treated with AE-CB for 48 h. Cell death assay indicated that SMMC-7721 cells underwent apoptosis in a dose-dependent manner induced by AE-CB. In addition, AE-CB treatment could downregulate the protein level of Bcl-2 and upregulate the Bax, leading to the increase in the ratio of Bax to Bcl-2 in SMMC-7721 cells. Meanwhile, it was observed that the expression of Survivin and c-Myc decreased, but the expression of P53 increased. All these events were associated with increase of reactive oxygen species. The data indicated that mitochondrial pathway might play an important role in bile extract-induced apoptosis in SMMC-7721 cells. These results provide significant insight into the anticarcinogenic action of bile extract on SMMC-7721 cells.     

Novel Bradykinin Receptor Inhibitors Inhibit Proliferation and Promote the Apoptosis of Hepatocellular Carcinoma Cells by Inhibiting the ERK Pathway

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide. Studies have shown that bradykinin (BK) is highly expressed in liver cancer. We designed the novel BK receptor inhibitors J051-71 and J051-105, which reduced the viability of liver cancer cells and inhibited the formation of cancer cell colonies. J051-71 and J051-105 reduced cell proliferation and induced apoptosis in HepG2 and BEL-7402 cells, which may be due to the inhibition of the extracellular regulated protein kinase (ERK) signaling pathway. In addition, these BK receptor inhibitors reversed the cell proliferation induced by BK in HepG2 and BEL-7402 cells by downregulating B1 receptor expression. Inhibiting B1 receptor expression decreased the protein levels of p-ERK and reduced the malignant progression of HCC, providing a potential target for HCC therapy.     

Apoptosis of T-47D Cells Induced by Cinobufacini via a Caspase-3-dependent Manner

To investigate the mechanism of the anti-tumor activity of cinobufacini on the breast cancer cell line T-47D,the inhibitory effect of cinobufacini on the proliferation of T-47D was detected via MTT assay and the morphological changes of T-47D and HBL-100 cells caused by cinobufacini were observed with an inverted microscope.Cell apoptosis and cell cycle stages were detected by flow cytometry analysis.The effects of cinobufacini on the expression of active-form and pro-form of caspase-3 were assessed by Western blot analysis.Cinobufacini dramatically inhibited T-47D proliferation in a dose-and time-dependent manner.We found that more than 20％ of T-47D cells were killed after treatment with 20 mg/mL cinobufacini for 24 h in vitro.After 6 d of treatment with 20 mg/mL cinobufacini,the cell survival rate decreased by more than 40％.Flow cytometric analysis demonstrated that cinobufacini induced significant apoptosis and changes of the cell cycle distribution of T-47D cells.We used breast cell line HBL-100 as the control,the above experiments except cell cycle analysis showed that cinobufacini more obviously induced the apoptosis of T-47D cells than that of HBL-100 cells.Western blot analysis confirmed the protein expression of active caspase-3 increased with increasing the dose of cinobufacini.These results indicate that cinobufacini induces the apoptosis of T-47D cells via the up-regulation of caspase-3.     

单手性臂型脱氧胆酸分子裂缝对中性小分子的识别性能研究

利用紫外分光光度滴定法测定了新型分子裂缝1～6对于苯胺、对甲氧基苯胺、对硝基苯胺等中性小分子的识别性能.结果表明所有的主体均对考察的客体具有识别作用,形成1:1型的超分子配合物.识别作用的主要推动力为多重氢键、π-πstacking等的协同作用.讨论了主客体间尺寸/形状、几何互补等因素对形成超分子配合物的影响.并利用1H NMR、计算机模拟作辅助手段对实验结果和现象进行了解释.     

Laminarin Induces Apoptosis of Human Colon Cancer LOVO Cells through a Mitochondrial Pathway

Many scientific studies have shown that laminarin has anti-tumor effects, but the anti-tumor mechanism was unclear. The purpose of this study was to investigate the effect of laminarin on the induction of apoptosis in human colon cancer LOVO cells and the molecular mechanism involved. LOVO cells were treated with different concentrations of laminarin at different times. Morphology observations were performed to determine the effects of laminarin on apoptosis of LOVO cells. Flow cytometry (FCM) was used to detect the level of intracellular reactive oxygen species (ROS) and pH. Laser scanning confocal microscope (LSCM) was used to analyze intracellular calcium ion concentration, mitochondrion permeability transition pore (MPTP) and mitochondrial membrane potential (MMP). Western blotd were performed to analyze the expressions of Cyt-C, Caspase-9 and -3. The results showed the apoptosis morphology, which showed cell protuberance, concentrated cytoplasm and apoptotic bodies, was obvious after 72 h treatment. Laminarin treatment for 24 h increased the intracellular level of ROS and Ca²⁺; decreased pH value; activated intracellular MPTP and decreased MMP in dose-dependent manners. It also induced the release of Cyt-C and the activation of Caspase-9 and -3. In conclusion, laminarin induces LOVO cell apoptosis through a mitochondrial pathway, suggesting that it could be a potent agent for cancer prevention and treatment.     

柠檬酸镧诱导肿瘤细胞凋亡的研究

采用噻唑蓝(MTT)法检测稀土化合物柠檬酸镧在1×10-3～5 mmol·L-1浓度范围内对体外培养的人乳腺癌细胞株MCF-7、前列腺癌细胞株PC-3、肝癌细胞株HepG2和宫颈癌细胞株HeLa生长的影响.结果表明,柠檬酸镧对各种癌细胞生长的影响存在浓度依赖性,在实验浓度范围内,低浓度无明显作用特征,高浓度抑制癌细胞生长;不同肿瘤细胞对稀土的响应不同,HeLa细胞相对敏感,其IC50值为(0.16±0.08)mmol·L-1,而MCF-7细胞为(0.18±0.02)mmol·L-1,PC-3细胞为(1.55±0.45)mmol·L-1,HepG2细胞为(2.71±0.11)mmol·L-1.进一步以0.15 mmol·L-1的柠檬酸镧作用于HeLa细胞,采用Hoechst 33258荧光染色、PI单染流式细胞仪检测、Annexin V-FITC/PI双染色法观察镧对HeLa细胞的毒性作用.结果表明,柠檬酸镧作用24 h后,HeLB细胞出现明显的凋亡特征,PI染色流式细胞仪检测可见凋亡峰,细胞周期分析表明sub-G1期细胞硅著增加,G0/G1期细胞显著减少(P<0.05),Annexin V-FITC/PI双染检测细胞凋亡率为(61.65±4.60)%(P<0.05).上述结果表明柠檬酸镧能诱导癌细胞发生凋亡.以HeLa细胞最灵敏而对HepG2并不敏感,其次序为HeLa>McF-7>Pc-3>HepG2.     

High Levels of Glucose Induces a Dose-Dependent Apoptosis in Human Periodontal Ligament Fibroblasts by Activating Caspase-3 Signaling Pathway

Periodontitis is one of the main complications of diabetes mellitus and many researches have been done on the relationship between periodontitis and diabetes mellitus, but too much are still unclear, especially the mechanisms by which high glucose induces damage of periodontal ligament fibroblasts. So in this study, we investigated the effects of different concentration of high glucose on apoptosis in human periodontal ligament fibroblasts and the possible mechanisms involved. Human periodontal ligament fibroblasts were cultured and subjected to glucose of different concentration (5.5, 15, 25, and 35 mM) for 24 h. Apoptosis was studied by flow cytometry, caspase assays, fluorescent real-time PCR and Western blot. We also determined Fas/FasL expression was by Western blot. The application of different concentration of high glucose induced a concentration-dependent increase of apoptosis and the activity of caspase-3 in cultured human periodontal ligament fibroblasts. Furthermore, inhibitor of caspase-3 could prevent the high-glucose-induced apoptosis in human periodontal ligament fibroblasts. Protein levels of Fas and FasL remained unchanged. These data indicate that high glucose induces a concentration- and caspase-3-dependent increase of apoptosis in cultured human periodontal ligament fibroblasts in vitro. Activation of caspase-3 caused by high glucose is independent of Fas/FasL signaling pathways system. These results suggest a novel mechanism for the regulation of human periodontal ligament fibroblasts apoptosis by high glucose.     

稀土对人正常肝细胞株7701和人宫颈癌Hela细胞生长的影响及其诱导细胞凋亡的作用

采用MTT法考察了16种稀土元素在9×10-8~2×10-4mol.L-1浓度范围内对体外培养的人正常肝细胞株7701细胞和宫颈癌Hela细胞的生长的影响。结果表明,稀土对细胞生长的影响存在浓度依赖性;低浓度促进细胞增殖,高浓度抑制细胞生长;不同稀土离子对细胞作用强弱不同,稀土间存在轻重分组效应;不同细胞对稀土的响应不同,表现出稀土对正常细胞和癌细胞作用的某种选择性。Hoechst 33258标记细胞DNA,用激光共聚焦显微镜和流式细胞仪对稀土处理的肝细胞株7701进行形态学观察和DNA含量分析。结果表明,较高浓度的稀土作用后的肝细胞株7701出现了明显的凋亡特征,稀土表现出的细胞毒性作用,其本质是诱导细胞发生凋亡。     

Protective Effect of Ferulic Acid against Hydrogen Peroxide Induced Apoptosis in PC12 Cells

Ferulic Acid (FA) is a highly abundant phenolic phytochemical which is present in plant tissues. FA has biological effects on physiological and pathological processes due to its anti-apoptotic and anti-oxidative properties, however, the detailed mechanism(s) of function is poorly understood. We have identified FA as a molecule that inhibits apoptosis induced by hydrogen peroxide (H₂O₂) or actinomycin D (ActD) in rat pheochromocytoma, PC12 cell. We also found that FA reduces H₂O₂-induced reactive oxygen species (ROS) production in PC12 cell, thereby acting as an anti-oxidant. Then, we analyzed FA-mediated signaling responses in rat pheochromocytoma, PC12 cells using antibody arrays for phosphokinase and apoptosis related proteins. This FA signaling pathway in PC12 cells includes inactivation of pro-apoptotic proteins, SMAC/Diablo and Bad. In addition, FA attenuates the cell injury by H₂O₂ through the inhibition of phosphorylation of the extracellular signal-regulated kinase (ERK). Importantly, we find that FA restores expression levels of brain-derived neurotrophic factor (BDNF), a key neuroprotective effector, in H₂O₂-treated PC12 cells. As a possible mechanism, FA increases BDNF by regulating microRNA-10b expression following H₂O₂ stimulation. Taken together, FA has broad biological effects as a neuroprotective modulator to regulate the expression of phosphokinases, apoptosis-related proteins and microRNAs against oxidative stress in PC12 cells.     

Djulis (Chenopodium formosanum) and Its Bioactive Compounds Protect Human Lung Epithelial A549 Cells from Oxidative Injury Induced by Particulate Matter via Nrf2 Signaling Pathway

The protective effects of water extracts of djulis (Chenopodium formosanum) (WECF) and their bioactive compounds on particulate matter (PM)-induced oxidative injury in A549 cells via the nuclear factor-erythroid 2-related factor 2 (Nrf2) signaling were investigated. WECF at 50–300 µg/mL protected A549 cells from PM-induced cytotoxicity. The cytoprotection of WECF was associated with decreases in reactive oxygen species (ROS) generation, thiobarbituric acid reactive substances (TBARS) formation, and increases in superoxide dismutase (SOD) activity and glutathione (GSH) contents. WECF increased Nrf2 and heme oxygenase-1 (HO-1) expression in A549 cells exposed to PM. SP600125 (a JNK inhibitor) and U0126 (an ERK inhibitor) attenuated the WECF-induced Nrf2 and HO-1 expression. According to the HPLC-MS/MS analysis, rutin (2219.7 µg/g) and quercetin derivatives (2648.2 µg/g) were the most abundant bioactive compounds present in WECF. Rutin and quercetin ameliorated PM-induced oxidative stress in the cells. Collectively, the bioactive compounds present in WECF can protect A549 cells from PM-induced oxidative injury by upregulating Nrf2 and HO-1 via activation of the ERK and JUN signaling pathways.     

Protective Effects of L-Theanine on IPEC-J2 Cells Growth Inhibition Induced by Dextran Sulfate Sodium via p53 Signaling Pathway

L-theanine is a nonprotein amino acid found in tea leaves and has been widely used as a safe food additive in beverages or foods because of its varied bioactivities. The aim of this study was to reveal the in vitro gastrointestinal protective effects of L-theanine in DSS-induced intestinal porcine enterocyte (IPEC-J2) cell models using molecular and metabolic methods. Results showed that 2.5% dextran sulfate sodium (DSS) treatment inhibited the cell proliferation of IPEC-J2 and blocked the normal operation of the cell cycle, while L-theanine pretreatment significantly preserved these trends to exert protective effects. L-theanine pre-treatment also up-regulated the EGF, CDC2, FGF2, Rb genes and down-regulated p53, p21 proliferation-related mRNA expression in DSS-treated cells, in accompany with p53 signaling pathway inhibition. Meanwhile, metabolomics analysis revealed that L-theanine and DSS treated IPEC-J2 cells have different metabolomic profiles, with significant changes in the key metabolites involved in pyrimidine metabolism and amino acid metabolism, which play an important role in nucleotide metabolism. In summary, L-theanine has a beneficial protection in DSS-induced IPEC-J2 cells via promoting proliferation and regulating metabolism disorders.