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This study aimed to investigate the neurotoxicity induced by trichloroacetic acid (TCA) and the possible protective mechanisms of boron (B). Mouse BV2 cells were treated with TCA (0, 0.39, 0.78, 1.56, 3.12, 6.25, or 12.5 mmol/L) and B (0, 7.8, 15.6, 31.25, 62.5, 125, 500, or 1,000 mmol/L) for 3 h and 24 h, respectively. Then, reactive oxygen species, and supernatant proinflammatory cytokine and protein levels were analyzed after 24 h of combined exposure. Beyond the dose-dependent decrease in the cellular viability, it clearly increased after B supplementation ( P < 0.05). Moreover, B decreased oxidative damage, and significantly down-regulated IL-6 levels and up-regulated TNF-β production ( P < 0.05). B also decreased apoptosis via the p53 pathway. The present findings indicated that TCA may induce oxidative damage, whereas B mitigates these adverse effects by decreasing cell apoptosis.
Subject(s)
Animals , Mice , Apoptosis , Boron/toxicity , Oxidative Stress , Reactive Oxygen Species/metabolism , Trichloroacetic Acid/toxicity , Tumor Suppressor Protein p53/metabolismABSTRACT
Objective:To investigate all-trans retinoic acid(ATRA)-induced apoptosis signaling pathway in ARPE-19 cells in vitro. Methods:The APRE-19 cell was treated with different concentrations of ATRA for 24 hours and 48 hours.Cell counting kit-8 (CCK-8) was used to detect the cell viability in order to determine the experimental concentration range.Flow cytometry and Western blot method were performed to evaluate the apoptosis and caspase related protein levels in ARPE-19 cells treated with 0, 2.5, 5, 10, 15 and 20 μmol/L of ATRA for 24 hours.Flow cytometry was used to detect the reactive oxygen species (ROS) and multicaspase levels and quantitative real-time PCR was carried out to determine the mRNA relative expression levels of caspase related proteins in ARPE-19 cells treated with 0, 2.5, 5, 10 and 20 μmol/L of ATRA, and 0 μmol/L ATRA group was used as the blank control group.Results:CCK-8 test showed that the half maximal inhibitory concentration of ARPE-19 cells treated with different concentrations of ATRA for 24 hours and 48 hours were 13.88 μmol/L and 11.99 μmol/L, respectively.The cell survival rates of ARPE-19 cells treated with different concentrations of ATRA for 24 hours and 48 hours were significantly different ( F=176.60, 350.30; both at P<0.01). When cultured for 24 hours, the cell survival rates of ARPE-19 cells in the 2 μmol/L and 6 μmol/L of ATRA groups were higher than that of the blank control group (both at P<0.05), and the cell survival rates of ARPE-19 cells in the 12, 14, 16, 18 and 20 μmol/L of ATRA groups were lower than that of the blank control group (all at P<0.05). Flow cytometry showed that there were significant differences in the apoptosis, ROS and multicaspase level among ARPE-19 cell groups treated with different concentrations of ATRA ( F=86.39, 116.84, 101.40; all at P<0.01). The apoptosis rates of APRE-19 cells in the 2.5 μmol/L and 5 μmol/L of ATRA groups were significantly decreased than that of the blank control group, and the apoptosis rate of APRE-19 cells in the 10, 15 and 20 μmol/L of ATRA groups were significantly increaseded than that of the blank control group (all at P<0.01). The relative expression levels of multicaspase and ROS were significantly higher in the 2.5, 5, 10 and 20 μmol/L of ATRA groups than that of the blank control group (all at P<0.01). Western blot assay showed that the relative expression level of caspase 9 was increased in the 2.5, 5, 10, 15 and 20 μmol/L of ATRA groups than that of the blank control group (all at P<0.05). Compared with the blank control group, the relative expression levels of caspase 12 were increased in the 2.5 μmol/L of ATRA group and reduced gradually in the 5, 10, 15 and 20 μmol/L of ATRA groups, among which there were significant differences between the blank control group and 2.5, 15, and 20 μmol/L of ATRA groups (all at P<0.05). The relative expression level of caspase 3 was significantly increased in the 5, 10 and 20 μmol/L of ATRA groups than that of the blank control group (all at P<0.05). The relative expression level of cleaved caspase 3 was significantly increased in the 2.5, 5, 10, 15 and 20 μmol/L of ATRA groups than that of the blank control group (all at P<0.01). Quantitative real-time PCR assay showed that the relative expression levels of caspase 9 and caspase 12 mRNA were significantly higher in the 2.5, 5, 10 and 20 μmol/L of ATRA groups than that of the blank control group (all at P<0.01). The relative expression levels of caspase 3 mRNA were significantly higher in the 5 μmol/L and 10 μmol/L of ATRA groups than that of the blank control group (both at P<0.01). When the concentration of ATRA was lower than 10 μmol/L, the relative expression levels of caspase 9 and caspase 12 mRNA were elevated in a concentration-dependent manner.When the concentration of ATRA reached 20 μmol/L, the relative expression levels of caspase 9 and caspase 12 mRNA were markedly decreased, but it was still higher than that of the blank control group. Conclusions:ATRA induces apoptosis in ARPE-19 cells in vitro through activating the reactive oxygen species and endogenous caspase-dependent apoptotic pathway.
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Hepatocellular carcinoma (HCC) is a malignant tumor with high morbidity and mortality globally. It accounts for the majority of primary liver cancer cases. Amyloid precursor protein (APP), a cell membrane protein, plays a vital role in the pathogenesis of Alzheimer’s disease, and has been found to be implicated in tumor growth and metastasis. Therefore, to understand the relationship between APP and 5-fluorouracil (5-FU) resistance in liver cancer, Cell Counting Kit-8, apoptosis and cell cycle assays, western blotting, and reverse transcription-quantitative polymerase chain reaction (qPCR) analysis were performed. The results demonstrated that APP expression in Bel7402-5-FU cells was significantly up-regulated, as compared with that in Bel7402 cells. Through successful construction of APP-silenced (siAPP) and overexpressed (OE) Bel7402 cell lines, data revealed that the Bel7402-APP751-OE cell line was insensitive, while the Bel7402-siAPP cell line was sensitive to 5-FU in comparison to the matched control group. Furthermore, APP overexpression decreased, while APP silencing increased 5-FU-induced apoptosis in Bel7402 cells. Mechanistically, APP overexpression and silencing can regulate the mitochondrial apoptotic pathway and the expression of apoptotic suppressor genes (B-cell lymphoma-2 (Bcl-2) and B-cell lymphoma-extra large (Bcl-xl)). Taken together, these results preliminarily revealed that APP overexpression contributes to the resistance of liver cancer cells to 5-FU, providing a new perspective for drug resistance.
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Resveratrol (3,5,4'-trihydroxystilbene, RSV) has been widely used in mammalian cells, but whether it can be used during freezing boar semen is still unknown. The effects of RSV treatment during boar semen freezing on its anti-freezing ability, apoptosis, and possible apoptotic pathways were observed in this study. Sperm motility, mitochondrial membrane potential (ΔΨm), adenosine triphosphate (ATP) content, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling (TUNEL)-positive apoptotic state, and messenger RNA (mRNA) expression levels of apoptotic genes involved in different apoptotic pathways after freezing with or without RSV treatment were tested. The results showed that: (1) Compared with fresh sperm, the motility, normal acrosome rate, and plasma membrane integrity rate of frozen boar sperm decreased significantly (P0.05), but it did significantly improve the normal acrosome rate (57.65% vs. 47.00%, P<0.05) and plasma membrane integrity rate (46.67% vs. 38.85%, P<0.05). (2) After freezing, most boar sperm showed low mitochondrial ΔΨm. RSV treatment could increase the rate of high mitochondrial ΔΨm of boar sperm. (3) RSV treatment significantly decreased reactive oxygen species (ROS) levels (58.65% vs. 88.41%, P<0.05) and increased the ATP content (0.49 μmol/L vs. 0.25 μmol/L, P<0.05) of boar sperm during freezing. (4) The apoptotic rate of the freezing group (80.41%) with TUNEL detection increased significantly compared to the fresh group (9.70%, P<0.05), and RSV treatment greatly decreased the apoptotic rate (68.32%, P<0.05). (5) Real-time polymerase chain reaction (RT-PCR) showed that not only the genes from the death receptor-mediated apoptotic pathway (tumor necrosis factor-α (TNF-α), Fas ligand (FasL), and Caspase-8), but also the genes from the mitochondria-mediated apoptotic pathway (manganese superoxide dismutase (MnSOD), B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), and Caspase-9) were both significantly changed after freezing. RSV treatment during freezing greatly changed their expression levels. Although RSV treatment during boar semen freezing did not significantly increase motility after thawing, it still played an efficient antioxidant role, which could enhance the mitochondrial function and decrease the apoptotic level induced by both the death receptor- and mitochondria-mediated apoptotic pathways.
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Resveratrol (3,5,4'-trihydroxystilbene, RSV) has been widely used in mammalian cells, but whether it can be used during freezing boar semen is still unknown. The effects of RSV treatment during boar semen freezing on its anti-freezing ability, apoptosis, and possible apoptotic pathways were observed in this study. Sperm motility, mitochondrial membrane potential (ΔΨ), adenosine triphosphate (ATP) content, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling (TUNEL)-positive apoptotic state, and messenger RNA (mRNA) expression levels of apoptotic genes involved in different apoptotic pathways after freezing with or without RSV treatment were tested. The results showed that: (1) Compared with fresh sperm, the motility, normal acrosome rate, and plasma membrane integrity rate of frozen boar sperm decreased significantly (P0.05), but it did significantly improve the normal acrosome rate (57.65% vs. 47.00%, P<0.05) and plasma membrane integrity rate (46.67% vs. 38.85%, P<0.05). (2) After freezing, most boar sperm showed low mitochondrial ΔΨ. RSV treatment could increase the rate of high mitochondrial ΔΨ of boar sperm. (3) RSV treatment significantly decreased reactive oxygen species (ROS) levels (58.65% vs. 88.41%, P<0.05) and increased the ATP content (0.49 μmol/L vs. 0.25 μmol/L, P<0.05) of boar sperm during freezing. (4) The apoptotic rate of the freezing group (80.41%) with TUNEL detection increased significantly compared to the fresh group (9.70%, P<0.05), and RSV treatment greatly decreased the apoptotic rate (68.32%, P<0.05). (5) Real-time polymerase chain reaction (RT-PCR) showed that not only the genes from the death receptor-mediated apoptotic pathway (tumor necrosis factor-α (TNF-α), Fas ligand (FasL), and Caspase-8), but also the genes from the mitochondria-mediated apoptotic pathway (manganese superoxide dismutase (MnSOD), B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), and Caspase-9) were both significantly changed after freezing. RSV treatment during freezing greatly changed their expression levels. Although RSV treatment during boar semen freezing did not significantly increase motility after thawing, it still played an efficient antioxidant role, which could enhance the mitochondrial function and decrease the apoptotic level induced by both the death receptor- and mitochondria-mediated apoptotic pathways.
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The tubers of three orchidaceous plants, includingPleione bulbocodioides (Franch.) Rolfe, have been used as 'Shan-Ci-Gu' in traditional Chinese medicine for the treatment of bacterial infections and cancers for thousands of years. In this study, the effects of an acetoacetate (EtOAc) extract of P. bulbocodioides on the cell viability and apoptosis of THP-1 (human acute monocytic leukemia cell line) cells and its interaction with possible apoptotic pathways were investigated. THP-1 cells were treated with the EtOAc extract of P. bulbocodioides at different concentrations. The results showed that THP-1 cell viability was significantly inhibited by the EtOAc extract ofP. bulbocodioides with an IC50 of 51.37±2.68 µ g/ mL at 24 h. The examination of cytotoxic effects on healthy cells showed that the EtOAc extract of P. bulbocodioidesdid not show any effect on healthy Vero cells. Selectivity indexes were greater than 15.57, suggesting that the EtOAc extract of P. bulbocodioides had selective toxicity against THP-1 cells. The results of annexin V-FITC/PI and DAPI staining showed that the EtOAc extract of P. bulbocodioides induced cell apoptosis in a dose-dependent manner. The apoptotic rate was increased in the treatment groups compared with that in the control group (P<0.05). The distribution of cells in the G2 phase of the cell cycle increased along with typical cell apoptosis-induced morphological changes. The levels of the pro-apoptotic proteins Bax, cleaved PARP and cleaved caspase-3 increased with increasing concentration of acetoacetate extract of P. bulbocodioides, while the anti-apoptosis protein Bcl-2 was downregulated. Cyt c and AIF, which are characteristic proteins of the mitochondria-regulated intrinsic apoptosis pathway, also increased in the cytosol with increasing concentrations of the EtOAc extract of P. bulbocodioides. These results showed that the EtOAc extract of P. bulbocodioidessignificantly inhibits cell viability and induces cell apoptosis in the human leukemia cell line THP-1 through a mitochondria-regulated intrinsic apoptotic pathway
Os tubérculos de três plantas orquidáceas, incluindo Pleione bulbocodioides (Franch.) Rolfe, têm sido usados como "Shan-Ci-Gu" na medicina tradicional chinesa para o tratamento de infecções bacterianas e cânceres por milhares de anos. Neste estudo, os efeitos de um extrato de acetoacetato (EtOAc) de P. bulbocodioides na viabilidade celular e apoptose de células THP-1 (linhagem celular de leucemia monocítica aguda humana) e sua interação com possíveis vias apoptóticas foram investigados. As células THP-1 foram tratadas com o extrato EtOAc de P. bulbocodioides em diferentes concentrações. Os resultados mostraram que a viabilidade das células THP-1 foi significativamente inibida pelo extrato EtOAc de P. bulbocodioides com IC50 de 51,37 ± 2,68 µ g/mL às 24 h. O exame dos efeitos citotóxicos em células saudáveis mostrou que oextrato de EtOAc de P. bulbocodioides não mostrou nenhum efeito sobre células Vero saudáveis. Os índices de seletividade foram maiores que 15,57, sugerindo que o extrato de EtOAc de P. bulbocodioides teve toxicidade seletiva contra as células THP-1. Os resultados da coloração da anexina V-FITC/PI e DAPI mostraram que o extrato de EtOAc de P. bulbocodioides induziu a apoptose celular de maneira dose-dependente. A taxa de apoptose foi aumentada nos grupos de tratamento em comparação com o grupo controle (P <0,05). A distribuição de células na fase G2 do ciclo celular aumentou juntamente com alterações morfológicas típicas induzidas pela apoptose celular. Os níveis das proteínas pró-apoptóticas Bax, PARP clivada e caspase-3 clivada aumentaram com o aumento da concentração do extrato acetoacetato de P. bulbocodioides, enquanto a proteína anti-apoptose Bcl-2 foi regulada negativamente. Cyt c e AIF, que são proteínas características da via de apoptose intrínseca regulada por mitocôndrias, também aumentaram no citosol com concentrações crescentes do extrato de EtOAc de P. bulbocodioides. Estes resultados mostraram que o extrato de EtOAc de P. bulbocodioides inibe significativamente a viabilidade celular e induz a apoptose na linha celular de leucemia humana THP-1 através de uma via apoptótica intrínseca regulada por mitocôndrias.
Subject(s)
Leukemia , Cell Survival , Apoptosis , Orchidaceae , Mitochondria , Plant Tubers , THP-1 Cells , Medicine, Chinese Traditional , AcetoacetatesABSTRACT
Objective: Reactive oxygen species (ROS) are involved in a variety of biological phenomena and serve both deleterious and beneficial roles. ROS quantification and assessment of reaction networks are desirable but difficult because of their short half-life and high reactivity. Here, we describe a pro-oxidative model in a single human lung carcinoma SPC-A-1 cell that was created by application of extracellular H2O2 stimuli. Methods: Modified microfluidics and imaging techniques were used to determine O2•− levels and construct an O2•− reaction network. To elucidate the consequences of increased O2•− input, the mitochondria were given a central role in the oxidative stress mode, by manipulating mitochondria-interrelated cytosolic Ca2+ levels, mitochondrial Ca2+ uptake, auto-amplification of intra-cellular ROS and the intrinsic apoptotic pathway. Results and conclusions: Results from a modified microchip demonstrated that 1 mmol/L H2O2 induced a rapid increase in cellular O2•− levels (>27 vs. >406 amol in 20 min), leading to increased cellular oxidizing power (evaluated by ROS levels) and decreased reducing power (evaluated by glutathione (GSH) levels). In addition, we examined the dynamics of cytosolic Ca2+ and mitochondrial Ca2+ by confocal laser scanning microscopy and confirmed that Ca2+ stores in the endoplasmic reticulum were the primary source of H2O2-induced cytosolic Ca2+ bursts. It is clear that mitochondria have pivotal roles in determining how exogenous oxidative stress affects cell fate. The stress response involves the transfer of Ca2+ signals between organelles, ROS auto-amplification, mitochondrial dysfunction, and a caspase-dependent apoptotic pathway.
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Long non-coding RNA antisense non-coding RNA in the INK4 locus (ANRIL) has been reported to promote tumorigenesis via regulating microRNA (miR)-99a in gastric cancer cells. However, the role of each component involved in it is still not well understood. This study aimed to verify the role of ANRIL in gastric cancer as well as the underlying mechanisms. ANRIL levels in clinical gastric cancer tissues and cell lines were tested by qPCR. Effects of ANRIL silence on cell viability, migration and invasion, apoptosis, and miR-99a expression in MKN-45 and SGC-7901 cells were measured using CCK-8, Transwell assay, flow cytometry, and qPCR assays, respectively. Then, effects of miR-99a inhibition on ANRIL-silenced cells were evaluated. B-lymphoma Mo-MLV insertion region 1 (BMI1) expression, after abnormal expression of ANRIL and miR-99a, was determined. Finally, expression of key proteins in the apoptotic, Notch, and mTOR pathways was assessed. ANRIL level was elevated in gastric cancer tissues and cell lines. Knockdown of ANRIL suppressed cell viability, migration, and invasion, and increased apoptosis through up-regulating miR-99a. Furthermore, ANRIL silence down-regulated BMI1 via up-regulating miR-99a. BMI1 silence down-regulated Bcl-2 and key kinases in the Notch and mTOR pathways and up-regulated p16 and cleaved caspases. We verified the tumor suppressive effects of ANRIL knockdown in gastric cancer cells via crosstalk with miR-99a. Together, we provided a novel regulatory mechanism for ANRIL in gastric cancer, in which ANRIL silence down-regulated BMI1 via miR-99a, along with activation of the apoptotic pathway and inhibition of the Notch and mTOR pathways.
Subject(s)
Humans , Stomach Neoplasms/metabolism , Down-Regulation , MicroRNAs/metabolism , TOR Serine-Threonine Kinases/metabolism , RNA, Long Noncoding/genetics , Carcinogenesis/genetics , Stomach Neoplasms/pathology , Transfection , Gene Expression Regulation, Neoplastic , Up-Regulation , Apoptosis/genetics , Cell Line, Tumor , Neoplasm InvasivenessABSTRACT
Objective Little is known about the effect of RNAi on mitochondrial apoptotic pathways. This study aims to explore the effects of the Survivin shRNA-APC double-gene on colon cancer mitochondrial apoptosis pathway-related factors survivin,cytochrome C (Cytc),second mitochondria-derived activator of caspases (Smac),and cysteine aspartic acid specific protease 9 (Caspase-9) as well as on the apoptosis of colon cancer transplanted tumor (CCTT) cells. Methods Thirty nude mice were randomly divided into five groups of equal number,Survivin shRNA-APC double-gene,survivin shRNA,APC,empty vector and blank transfection. The CCTT model was established in the nude mice by subcutaneous injection of the colon cancer cell strains stably transfected with the Survivin shRNA-APC double-gene,survivin shRNA,APC,an empty vector and HT-29,respectively,into the mid-posterior part of the left armpit of the nude mice. The rate of tumor growth inhibition was calculated by measuring the volume and weight of the CCTTs in the nude mice. The mRNA and protein expressions of survivin,Cytc,Smac and Caspase-9 in the tumor tissue were detected by real time PCR and immunohistochemistry,respectively,and the apoptosis rate of the CCTT cells was detected by TUNEL. Results The model of CCTT was successfully established in the nude mice. Com-pared with the empty vector and blank transfection groups,the mice in the double-gene,survivin shRNA and APC groups showed sig-nificantly decreased average volume and weight of the tumor tissue (P<0.05) but increased inhibition rate of its volume and weight (P<0.05). In comparison with the survivin shRNA and APC groups,the double-gene group exhibited remarkably decreased average volume and weight of the tumor tissue (P<0.05) but increased inhibition rate of its volume and weight (P<0.05). The mRNA and pro-tein expressions of survivin were significantly lower while those of Cytc,Smac and Caspase-9 markedly higher in the double-gene,sur-vivin shRNA and APC groups than in the empty vector and blank transfection groups (P<0.05),the former even lower (P<0.05) and the latter even higher in the double-gene than in the survivin shRNA and APC groups (P<0.05). The apoptosis rate of the CCTT cells was significantly increased in the double-gene ([56.78±3.04]%),survivin shRNA ([33.61±2.02]%) and APC groups ([30.16± 1.72]%) as compared with the empty vector ([10.05±0.42]%) and blank transfection groups ([9.87±0.30])% (P<0.05),even higher in the double-gene group than in the survivin shRNA and APC groups (P<0.05). Conclusion The Survivin shRNA-APC double-gene may induce apoptosis of colon cancer transplanted tumor cells by down-regulating the expression of the apoptosis inhibitor survivin,upregulating the expressions of Cytc,Smac and Caspase-9,and suppressing the growth of the colon transplanted tumor,with more significant abilities than a single gene in regulating apoptosis-related factors,inducing cell apoptosis and inhibiting the growth of the transplanted tumor.
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AIM:To investigate the effects of survivin inhibitor YM155 {4,9-dihydro-1-(2-methoxyethyl)-2-methyl-4,9-dioxo-3-(2-pyrazinylmethyl)-4,9-dihydro-1H-naphtho[2,3-d]imidazolium bromide} on the apoptosis, mito-chondrial membrane potential (Δψm) and cytochrome C (Cyt C) of retinoblastoma Y79 cells, and to analyze the mitochon-drial mechanisms of apoptosis .METHODS:Y79 cells were cultured in vitro and treated with YM155 at concentrations of 0, 0.5, 1, 2, 4 and 8 nmol/L.The cells in control group were treated without YM 155.The proliferation of Y79 cells were measured by CCK-8 assay and bromodeoxyuridine ( BrdU) labeling assay .Y79 cells were randomly divided into 4 groups:control group ( with equal volume of RPMI-1640 nutrient medium ) , positive control group ( 10 nmol/L topotecan ) , low-dose (1 nmol/L) YM155 group and high-dose (2 nmol/L) YM155 group.The effects of YM155 on the apoptosis, the changes of Δψm , the mitochondrial distribution and the protein level of Cyt C in the Y 79 cells were evaluated by flow cytom-etry with Annexin V-FITC/PI staining, JC-1 staining, immunofluorescence analysis and Western blot , respectively.RE-SULTS:Compared with control group , YM155 significantly inhibited the proliferation of Y 79 cells and induced apoptosis (P<0.05).YM155 significantly reduced Δψm of the Y79 cells, promoted Cyt C which released from mitochondria to the cytosol and reduced the protein level of Cyt C in the mitochondria (P<0.05).CONCLUSION:YM155 inhibits Y79 cell proliferation and induces apoptosis , and the possible mechanisms may be involved in the mitochondrium-mediated apoptotic pathway .
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<p><b>OBJECTIVE</b>To examine the role of Cd-induced reactive oxygen species (ROS) generation in the apoptosis of neuronal cells.</p><p><b>METHODS</b>Neuronal cells (primary rat cerebral cortical neurons and PC12 cells) were incubated with or without Cd post-pretreatment with rapamycin (Rap) or N-acetyl-L-cysteine (NAC). Cell viability was determined by MTT assay, apoptosis was examined using flow cytometry and fluorescence microscopy, and the activation of phosphoinositide 3'-kinase/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) and mitochondrial apoptotic pathways were measured by western blotting or immunofluorescence assays.</p><p><b>RESULTS</b>Cd-induced activation of Akt/mTOR signaling, including Akt, mTOR, p70 S6 kinase (p70 S6K), and eukaryotic initiation factor 4E binding protein 1 (4E-BP1). Rap, an mTOR inhibitor and NAC, a ROS scavenger, blocked Cd-induced activation of Akt/mTOR signaling and apoptosis of neuronal cells. Furthermore, NAC blocked the decrease of B-cell lymphoma 2/Bcl-2 associated X protein (Bcl-2/Bax) ratio, release of cytochrome c, cleavage of caspase-3 and poly(ADP-ribose) polymerase (PARP), and nuclear translocation of apoptosis-inducing factor (AIF) and endonuclease G (Endo G).</p><p><b>CONCLUSION</b>Cd-induced ROS generation activates Akt/mTOR and mitochondrial pathways, leading to apoptosis of neuronal cells. Our findings suggest that mTOR inhibitors or antioxidants have potential for preventing Cd-induced neurodegenerative diseases.</p>
Subject(s)
Animals , Rats , Apoptosis , Cadmium , Toxicity , Caspases , Metabolism , Mitochondria , Neurons , PC12 Cells , Proto-Oncogene Proteins c-akt , Metabolism , Rats, Sprague-Dawley , Reactive Oxygen Species , Metabolism , Signal Transduction , TOR Serine-Threonine Kinases , MetabolismABSTRACT
Objective To investigate the expression of AIF, CYT C, PAF-1, caspase-3, and XIAP in Sprague-Dawley rats with spontaneous mammary neoplasms.Methods One-hundred and thirty 3-4-week old SPF Spargue-Dawley rats (♀∶♂=1∶1) were fed in a specific pathogen free (SPF) breeding barrier for 60 weeks.The occurrence of spontane-ous breast tumors was recorded and histopathology was performed to identify the types of tumors.The rats were divided into 3 groups:rats with normal breast tissue ( group I) , with benign tumors ( group II) and with malignant tumors ( group III) . The expression of AIF, CYT C, APAF-1, caspase-3 and XIAP proteins and mRNAs were detected by immunhistochemistry ( IHC) and RT-PCR assay.Results Among these 130 SD rats, 14 rats were observed having spontaneous mammary neo-plasms with the incidence rate of 10.77%(14/130).In these neoplasm cases, 7 cases were mammary fibroadenomas, 7 cases of breast carcinoma, both with an incidence rate of 5.38%.Immunohistochemistry showed that, compared with the group I, the positive expressions of AIF, APAF-1, caspase-3 were decreased significantly (P<0.01), and the CYT C and XIAP expressions were significantly increased in the group II.The positive expression of all genes except XIAP was de-creased in the group III(P<0.01).Compared with the group II, APAF-1 and XIAP were significantly higher in the group III (P<0.01), and the positive expression of AIF, Cyt C, and caspases-3 were significantly decreased (P<0.01).In the results of RT-PCR assay, except APAF-1 which showed significant correlation with the results of immunohistochemistry ( P<0.05 ) , all the others showed an extremely significant correlation with immunohistochemical results ( P <0.01 ) . Conclusions Mammary tumors are most common spontaneous neoplasms in SD rats.Abnormal expression of mitochondrial apoptotic pathway-related factors AIF, CytC, APAF-1, caspase-3, and XIAP are correlated with the carcinogenesis and de-velopment of breast tumors.
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Background:Clinical and epidemiological studies revealed that estrogen replacement therapy was associated with a significant reduction in risk of colorectal cancer in postmenopausal women.In our previous studies,estrogen increased the expression of mismatch repair (MMR)gene MLH1 in colonic cancer cells,and re-expression of MLH1 in MLH-deficient colonic cancer cells significantly increased the estrogen-induced apoptosis.Aims:To investigate the signaling pathway implicated in the MLH1-mediated apoptosis in colonic cancer cells induced by estrogen and the roles of p53 and its related genes in this apoptotic pathway.Methods:Plasmid containing wild type human MLH1 (hMLH1)full length cDNA was transfected into MLH1-deficient human colonic cancer cell line HCT116.By using HCT116 cells transfected with empty plasmid as controls,the apoptotic DNA ladder was determined by electrophoresis and the expressions of p53 and other apoptosis-related proteins were assessed by Western blotting under the condition with or without estrogen stimulation. Results:17β-estradiol (E2 )at the concentration of 10 -8 mol/L induced significant apoptosis in HCT116 cells transfected with hMLH1.In HCT116 cells transfected with hMLH1 and stimulated with E2 (group D),the protein expressions of caspase-3,caspase-9,p53,Bax and cytoplasmic cytochrome C increased significantly when compared with HCT116 cells stimulated with E2 only (group B);expressions of the abovementioned proteins were also higher in group D than in group C (transfected with hMLH1 only).Conclusions:MMR gene MLH1 is involved in estrogen-induced apoptosis of human colonic cancer cell line HCT116 by activating p53 signaling and mitochondrial apoptotic pathway.
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Objective To determine mitochondria-associated signaling pathway on cell apoptosis in Leptospira interrogans infected murine mononuclear-macrophages. Methods A cell apoptotic model of L. interrogan serogroup Icterohaemorrhagiae strain Lai inducing apoptosis of murine mononuclear-macrophage line (J774A. 1) was established. Pathological changes of mitochondria in the infected cells were observed under transmission electron microscope. Mitochondrial potential and reactive oxygen species(ROS) levels in the infected cells were detected using JC-1 staining method and DCFH-DA fluorescent probe, respectively,and caspase-8/-9 activities in the infected cells were measured using commercial kits. and the apoptosis block effects of caspase inhibitors were determined by flow cytometry. Apoptosis in the infected cells and ap-optosis-blocking effect by caspase inhibitors were detected by flow cytometry. Western blot assay was adopted to examine the levels of cytochrome C (CytC) , AIF, EndoG and Smae in the mitochondria and cytoplasm.The transposition of either AIF or EndoG from the cytoplasm into cell nucleus was determined by immunoflu-orescence staining test. Results L. interrogans strain Lai could induce J774A. 1 cell apoptoais. In the in-fected cells, visible mitochondrial injury, declined mitochondrial membrane potential and elevated ROS level were presented. The activity of caspase-8 but not of caspase-9 was significantly increased. The caspase in-hihitors could not completely block the cell apoptosis. Both the AIF and EndoG was released from the mito-chondria and subsequently transferred from the cytoplasm into the nucleus in the infected cells. However,elevation of CytC level and Smac release in cytoplasm of the infected cells could not be found. Conclusion L.interrogans can induce apoptosis in the infected mononuclear-macrophage via AIF and EndoG belonging to caspase-independent pathway.
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PURPOSE: Ataxia telangiectasia mutated(ATM) is involved in DNA damage responses at different cell cycle checkpoints, and signalling pathways associated with regulation of apoptosis in response to ionizing radiation(IR). However, the signaling pathway that underlies IR-induced apoptosis in ATM cells has remained unknown. The purpose of this study was, therefore, to investigate the apoptotic pathway that underlies IR-induced apoptosis in a CT-26 cells expressing dominant negative ATM (DN-ATM). METHODS: We generated a replication-deficient recombinant adenovirus encoding the DN-ATM(Ad/DN-ATM) or control adenovirus encoding no transgene(Ad/GFP) and infected adenovirus to CT-26 cells. After infection, we examined apoptosis and apoptotic pathway by [3H]-thymidine assay, DNA fragmentation, and Western immunoblot analysis. RESULTS: DN-ATM gene served as the creation of AT phenotype in a CT-26 cells as revealed by decreased cell proliferations following IR. In addition, IR-induced apoptosis was regulated through the reduced levels of the anti-apoptotic protein Bcl-2, the increased levels of the apoptotic protein Bax, and the activation of caspase-9, caspase-3, and PARP. CONCLUSION: These results indicate that the pathway of IR-induced apoptosis in CT-26 cells expressing DN-ATM is mediated by mitochondrial signaling pathway involving the activation of caspase 9, caspase 3, and PARP.
Subject(s)
Adenoviridae , Apoptosis , Ataxia Telangiectasia , Blotting, Western , Caspase 3 , Caspase 9 , Cell Cycle Checkpoints , Colon , Colonic Neoplasms , DNA Damage , DNA Fragmentation , Phenotype , Radiation, IonizingABSTRACT
AIM: To observe the effect of puerarin on myocardial injury according to the time of occurrence of myocardial injury in the development of type 2 diabetic mice.METHODS: The serum levels of glucose(GLU),triglyceride(TG),total cholesterin(TC),low density lipoprotein-cholesterol(LDL-C) and high density lipoprotein-cholesterol(HDL-C) in 17-week,20-week,24-week,28-week KKAy mice were detected by automatic biochemical methods.The apoptotic percentage of cardiomyocytes was examined by flow cytometry.The expressions of bax and bcl-2 mRNA in cardiomyocytes were detected by RT-PCR.Caspase-3 expression in cardiomyocytes was determined by immunohistochemical staining.RESULTS: Compared to normal control mice,not only GLU level increased,but also the levels of TG,TC,LDL-C,HDL-C in 20-week,24-week and 28-week KKAy mice increased apparently(P