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Sample records for arsenic induces apoptosis

  1. Immunomodulatory role of Emblica officinalis in arsenic induced oxidative damage and apoptosis in thymocytes of mice

    PubMed Central

    2013-01-01

    Background Arsenic is widely distributed in the environment and has been found to be associated with the various health related problems including skin lesions, cancer, cardiovascular and immunological disorders. The fruit extract of Emblica officinalis (amla) has been shown to have anti-oxidative and immunomodulatory properties. In view of increasing health risk of arsenic, the present study has been carried out to investigate the protective effect of amla against arsenic induced oxidative stress and apoptosis in thymocytes of mice. Methods Mice were exposed to arsenic (sodium arsenite 3 mg/kg body weight p.o.) or amla (500 mg/kg body weight p.o.) or simultaneously with arsenic and amla for 28 days. The antioxidant enzyme assays were carried out using spectrophotometer and generation of ROS, apoptotic parameters, change in cell cycle were carried out using flow cytometer following the standard protocols. Results Arsenic exposure to mice caused a significant increase in the lipid peroxidation, ROS production and decreased cell viability, levels of reduced glutathione, the activity of superoxide dismutase, catalase, cytochrome c oxidase and mitochondrial membrane potential in the thymus as compared to controls. Increased activity of caspase-3 linked with apoptosis assessed by the cell cycle analysis and annexin V/PI binding was also observed in mice exposed to arsenic as compared to controls. Co-treatment with arsenic and amla decreased the levels of lipid peroxidation, ROS production, activity of caspase-3, apoptosis and increased cell viability, levels of antioxidant enzymes, cytochrome c oxidase and mitochondrial membrane potential as compared to mice treated with arsenic alone. Conclusions The results of the present study exhibits that arsenic induced oxidative stress and apoptosis significantly protected by co-treatment with amla that could be due to its strong antioxidant potential. PMID:23889914

  2. Arsenic-induced alteration in intracellular calcium homeostasis induces head kidney macrophage apoptosis involving the activation of calpain-2 and ERK in Clarias batrachus

    SciTech Connect

    Banerjee, Chaitali; Goswami, Ramansu; Datta, Soma; Rajagopal, R.; Mazumder, Shibnath

    2011-10-01

    We had earlier shown that exposure to arsenic (0.50 {mu}M) caused caspase-3 mediated head kidney macrophage (HKM) apoptosis involving the p38-JNK pathway in Clarias batrachus. Here we examined the roles of calcium (Ca{sup 2+}) and extra-cellular signal-regulated protein kinase (ERK), the other member of MAPK-pathway on arsenic-induced HKM apoptosis. Arsenic-induced HKM apoptosis involved increased expression of ERK and calpain-2. Nifedipine, verapamil and EGTA pre-treatment inhibited the activation of calpain-2, ERK and reduced arsenic-induced HKM apoptosis as evidenced from reduced caspase-3 activity, Annexin V-FITC-propidium iodide and Hoechst 33342 staining. Pre-incubation with ERK inhibitor U 0126 inhibited the activation of calpain-2 and interfered with arsenic-induced HKM apoptosis. Additionally, pre-incubation with calpain-2 inhibitor also interfered with the activation of ERK and inhibited arsenic-induced HKM apoptosis. The NADPH oxidase inhibitor apocynin and diphenyleneiodonium chloride also inhibited ERK activation indicating activation of ERK in arsenic-exposed HKM also depends on signals from NADPH oxidase pathway. Our study demonstrates the critical role of Ca{sup 2+} homeostasis on arsenic-induced HKM apoptosis. We suggest that arsenic-induced alteration in intracellular Ca{sup 2+} levels initiates pro-apoptotic ERK and calpain-2; the two pathways influence each other positively and induce caspase-3 mediated HKM apoptosis. Besides, our study also indicates the role of ROS in the activation of ERK pathway in arsenic-induced HKM apoptosis in C. batrachus. - Highlights: > Altered Ca{sup 2+} homeostasis leads to arsenic-induced HKM apoptosis. > Calpain-2 plays a critical role in the process. > ERK is pro-apoptotic in arsenic-induced HKM apoptosis. > Arsenic-induced HKM apoptosis involves cross talk between calpain-2 and ERK.

  3. Arsenic induces apoptosis in mouse liver is mitochondria dependent and is abrogated by N-acetylcysteine

    SciTech Connect

    Santra, Amal . E-mail: asantra2000@yahoo.co.in; Chowdhury, Abhijit; Ghatak, Subhadip; Biswas, Ayan; Dhali, Gopal Krishna

    2007-04-15

    Arsenicosis, caused by arsenic contamination of drinking water supplies, is a major public health problem in India and Bangladesh. Chronic liver disease, often with portal hypertension occurs in chronic arsenicosis, contributes to the morbidity and mortality. The early cellular events that initiate liver cell injury due to arsenicosis have not been studied. Our aim was to identify the possible mechanisms related to arsenic-induced liver injury in mice. Liver injury was induced in mice by arsenic treatment. The liver was used for mitochondrial oxidative stress, mitochondrial permeability transition (MPT). Evidence of apoptosis was sought by TUNEL test, caspase assay and histology. Pretreatment with N-acetyl-L-cysteine (NAC) was done to modulate hepatic GSH level. Arsenic treatment in mice caused liver injury associated with increased oxidative stress in liver mitochondria and alteration of MPT. Altered MPT facilitated cytochrome c release in the cytosol, activation of caspase 9 and caspase 3 activities and apoptotic cell death. Pretreatment of NAC to arsenic-treated mice abrogated all these alteration suggesting a glutathione (GSH)-dependent mechanism. Oxidative stress in mitochondria and inappropriate MPT are important in the pathogenesis of arsenic induced apoptotic liver cell injury. The phenomenon is GSH dependent and supplementation of NAC might have beneficial effects.

  4. Blockage of JNK pathway enhances arsenic trioxide-induced apoptosis in human keratinocytes

    SciTech Connect

    Huang, H.-S.; Liu, Z.-M.; Hong, D.-Y.

    2010-04-15

    Arsenic is well known as a carcinogen predisposing humans to some severe diseases and also as an effective medicine for treating acute promyelocytic leukemia, syphilis, and psoriasis. Multiple active mechanisms, including cell cycle arrest and apoptosis, have been proposed in therapy; however, the opposing effects of arsenic remain controversial. Our previous study found that arsenic trioxide (ATO)-induced activation of p21{sup WAF1/CIP1} (p21) led to A431 cell death through the antagonistic effects of the signaling of ERK1/2 and JNK1. In the current study, the inhibitory effects of JNK1 on ATO-induced p21 expression were explored. Over-expression of JNK1 in A431 cells could inhibit p21 expression, which was associated with HDAC1 and TGIF. Using the GST pull-down assay and fluorescence resonance energy transfer analysis, N-terminal domain (amino acids 1-108) of TGIF, critical to its binding with c-Jun, was found. Using reporter assays, requirement of the C-terminal domain (amino acids 138-272) of TGIF to suppress ATO-induced p21 expression was observed. Thus, the domains of TGIF that carried out its inhibitory effects on p21 were identified. Finally, treatment with JNK inhibitor SP600125 could enhance ATO-induced apoptosis of HaCaT keratinocytes by using flow cytometry.

  5. Role of Signal Regulatory Protein α in Arsenic Trioxide-induced Promyelocytic Leukemia Cell Apoptosis.

    PubMed

    Pan, Chaoyun; Zhu, Dihan; Zhuo, Jianjiang; Li, Limin; Wang, Dong; Zhang, Chen-Yu; Liu, Yuan; Zen, Ke

    2016-01-01

    Signal regulatory protein α (SIRPα) has been shown to operate as a negative regulator in cancer cell survival. The mechanism underneath such function, however, remains poorly defined. In the present study, we demonstrate that overexpression of SIRPα in acute promyelocytic leukemia (APL) cells results in apoptosis possibly via inhibiting the β-catenin signaling pathway and upregulating Foxo3a. Pharmacological activation of β-catenin signal pathway attenuates apoptosis caused by SIRPα. Interestingly, we also find that the pro-apoptotic effect of SIRPα plays an important role in arsenic trioxide (ATO)-induced apoptosis in APL cells. ATO treatment induces the SIRPα protein expression in APL cells and abrogation of SIRPα induction by lentivirus-mediated SIRPα shRNA significantly reduces the ATO-induced apoptosis. Mechanistic study further shows that induction of SIRPα protein in APL cells by ATO is mediated through suppression of c-Myc, resulting in reduction of three SIRPα-targeting microRNAs: miR-17, miR-20a and miR-106a. In summary, our results demonstrate that SIRPα inhibits tumor cell survival and significantly contributes to ATO-induced APL cell apoptosis. PMID:27010069

  6. Role of Signal Regulatory Protein α in Arsenic Trioxide-induced Promyelocytic Leukemia Cell Apoptosis

    PubMed Central

    Pan, Chaoyun; Zhu, Dihan; Zhuo, Jianjiang; Li, Limin; Wang, Dong; Zhang, Chen-Yu; Liu, Yuan; Zen, Ke

    2016-01-01

    Signal regulatory protein α (SIRPα) has been shown to operate as a negative regulator in cancer cell survival. The mechanism underneath such function, however, remains poorly defined. In the present study, we demonstrate that overexpression of SIRPα in acute promyelocytic leukemia (APL) cells results in apoptosis possibly via inhibiting the β-catenin signaling pathway and upregulating Foxo3a. Pharmacological activation of β-catenin signal pathway attenuates apoptosis caused by SIRPα. Interestingly, we also find that the pro-apoptotic effect of SIRPα plays an important role in arsenic trioxide (ATO)-induced apoptosis in APL cells. ATO treatment induces the SIRPα protein expression in APL cells and abrogation of SIRPα induction by lentivirus-mediated SIRPα shRNA significantly reduces the ATO-induced apoptosis. Mechanistic study further shows that induction of SIRPα protein in APL cells by ATO is mediated through suppression of c-Myc, resulting in reduction of three SIRPα-targeting microRNAs: miR-17, miR-20a and miR-106a. In summary, our results demonstrate that SIRPα inhibits tumor cell survival and significantly contributes to ATO-induced APL cell apoptosis. PMID:27010069

  7. Heat shock protein inhibitors, 17-DMAG and KNK437, enhance arsenic trioxide-induced mitotic apoptosis

    SciTech Connect

    Wu Yichen; Yen Wenyen; Lee, T.-C. Yih, L.-H.

    2009-04-15

    Arsenic trioxide (ATO) has recently emerged as a promising therapeutic agent in leukemia because of its ability to induce apoptosis. However, there is no sufficient evidence to support its therapeutic use for other types of cancers. In this study, we investigated if, and how, 17-dimethylaminoethylamino-17-demethoxy-geldanamycin (17-DMAG), an antagonist of heat shock protein 90 (HSP90), and KNK437, a HSP synthesis inhibitor, potentiated the cytotoxic effect of ATO. Our results showed that cotreatment with ATO and either 17-DMAG or KNK437 significantly increased ATO-induced cell death and apoptosis. siRNA-mediated attenuation of the expression of the inducible isoform of HSP70 (HSP70i) or HSP90{alpha}/{beta} also enhanced ATO-induced apoptosis. In addition, cotreatment with ATO and 17-DMAG or KNK437 significantly increased ATO-induced mitotic arrest and ATO-induced BUBR1 phosphorylation and PDS1 accumulation. Cotreatment also significantly increased the percentage of mitotic cells with abnormal mitotic spindles and promoted metaphase arrest as compared to ATO treatment alone. These results indicated that 17-DMAG or KNK437 may enhance ATO cytotoxicity by potentiating mitotic arrest and mitotic apoptosis possibly through increased activation of the spindle checkpoint.

  8. Arsenic induces cell apoptosis in cultured osteoblasts through endoplasmic reticulum stress

    SciTech Connect

    Tang, C.-H.; Chiu, Y.-C.; Huang, C.-F.; Chen, Y.-W.; Chen, P.-C.

    2009-12-01

    Osteoporosis is characterized by low bone mass resulting from an imbalance between bone resorption by osteoclasts and bone formation by osteoblasts. Therefore, decreased bone formation by osteoblasts may lead to the development of osteoporosis, and rate of apoptosis is responsible for the regulation of bone formation. Arsenic (As) exists ubiquitously in our environment and increases the risk of neurotoxicity, liver injury, peripheral vascular disease and cancer. However, the effect of As on apoptosis of osteoblasts is mostly unknown. Here, we found that As induced cell apoptosis in osteoblastic cell lines (including hFOB, MC3T3-E1 and MG-63) and mouse bone marrow stromal cells (M2-10B4). As also induced upregulation of Bax and Bak, downregulation of Bcl-2 and dysfunction of mitochondria in osteoblasts. As also triggered endoplasmic reticulum (ER) stress, as indicated by changes in cytosolic-calcium levels. We found that As increased the expression and activities of glucose-regulated protein 78 (GRP78) and calpain. Transfection of cells with GRP78 or calpain siRNA reduced As-mediated cell apoptosis in osteoblasts. Therefore, our results suggest that As increased cell apoptosis in cultured osteoblasts and increased the risk of osteoporosis.

  9. Endoplasmic reticulum stress contributes to arsenic trioxide-induced intrinsic apoptosis in human umbilical and bone marrow mesenchymal stem cells.

    PubMed

    King, Yih-An; Chiu, Yu-Jen; Chen, Hao-Ping; Kuo, Daih-Huang; Lu, Chi-Cheng; Yang, Jai-Sing

    2016-03-01

    Arsenic trioxide is an old drug and has been used for a long time in traditional Chinese and Western medicines. However, the cancer treatment of arsenic trioxide has heart and vascular toxicity. The cytotoxic effects of arsenic trioxide and its molecular mechanism in human umbilical mesenchymal stem cells (HUMSC) and human bone marrow-derived mesenchymal stem cells (HMSC-bm) were investigated in this study. Our results showed that arsenic trioxide significantly reduced the viability of HUMSC and HMSC-bm in a concentration- and time-dependent manner. Arsenic trioxide is able to induce apoptotic cell death in HUMSC and HMSC-bm, as shown from the results of morphological examination, flow cytometric analyses, DAPI staining and comet assay. The appearance of arsenic trioxide also led to an increase of intracellular free calcium (Ca(2+) ) concentration and the disruption of mitochondrial membrane potential (ΔΨm). The caspase-9 and caspase-3 activities were time-dependently increased in arsenic trioxide-treated HUMSC and HMSC-bm. In addition, the proteomic analysis and DNA microarray were carried out to investigate the expression level changes of genes and proteins affected by arsenic trioxide treatment in HUMSC. Our results suggest that arsenic trioxide induces a prompt induction of ER stress and mitochondria-modulated apoptosis in HUMSC and HMSC-bm. A framework was proposed for the effect of arsenic trioxide cytotoxicity by targeting ER stress. PMID:25258189

  10. Intracellular calcium disturbances induced by arsenic and its methylated derivatives in relation to genomic damage and apoptosis induction.

    PubMed

    Florea, Ana-Maria; Yamoah, Ebenezer N; Dopp, Elke

    2005-06-01

    Arsenic and its methylated derivatives are contaminants of air, water, and food and are known as toxicants and carcinogens. Arsenic compounds are also being used as cancer chemotherapeutic agents. In humans, inorganic arsenic is metabolically methylated to mono-, di-, and trimethylated forms. Recent findings suggest that the methylation reactions represent a toxification rather than a detoxification pathway. In recent years, the correlation between arsenic exposure, cytotoxicity and genotoxicity, mutagenicity, and tumor promotion has been established, as well as the association of arsenic exposure with perturbation of physiologic processes, generation of reactive oxygen species, DNA damage, and apoptosis induction. Trivalent forms of arsenic have been found to induce apoptosis in several cellular systems with involvement of membrane-bound cell death receptors, activation of caspases, release of calcium stores, and changes of the intracellular glutathione level. It is well known that calcium ion deregulation plays a critical role in apoptotic cell death. A calcium increase in the nuclei might lead to toxic effects in the cell. In this review, we highlight the relationship between induced disturbances of calcium homeostasis, genomic damage, and apoptotic cell death caused by arsenic and its organic derivatives. PMID:15929885

  11. Efficacy of crude extract of Emblica officinalis (amla) in arsenic-induced oxidative damage and apoptosis in splenocytes of mice

    PubMed Central

    Singh, Manish Kumar; Yadav, Suraj Singh; Yadav, Rajesh Singh; Singh, Uma Shanker; Shukla, Yogeshwar; Pant, Kamlesh Kumar; Khattri, Sanjay

    2014-01-01

    Introduction: Arsenic, an environmental contaminant naturally occurred in groundwater and has been found to be associated with immune-related health problems in humans. Objective: In view of increasing risk of arsenic exposure due to occupational and non-occupational settings, the present study has been focused to investigate the protective efficacy of amla against arsenic-induced spleenomegaly in mice. Results: Arsenic exposures (3 mg/kg body weight p.o for 30 days) in mice caused an increase production of ROS (76%), lipid peroxidation (84%) and decrease in the levels of superoxide dismutase (53%) and catalase (54%) in spleen as compared to controls. Arsenic exposure to mice also caused a significant increase in caspases-3 activity (2.8 fold) and decreases cell viability (44%), mitochondrial membrane potential (47%) linked with apoptosis assessed by the cell cycle analysis (subG1-28.72%) and annexin V/PI binding in spleen as compared to controls. Simultaneous treatment of arsenic and amla (500 mg/kg body weight p.o for 30 days) in mice decreased the levels of lipid peroxidation (33%), ROS production (24%), activity of caspase-3 (1.4 fold), apoptosis (subG1 12.72%) and increased cell viability (63%), levels superoxide dismutase (80%), catalase (77%) and mitochondrial membrane potential (66%) as compared to mice treated with arsenic alone. Conclusions: Results of the present study indicate that the effect of arsenic is mainly due to the depletion of glutathione in liver associated with enhanced oxidative stress that has been found to be protected following simultaneous treatment of arsenic and amla. PMID:24748729

  12. Arsenic Trioxide Induces Apoptosis in Human Platelets via C-Jun NH2-Terminal Kinase Activation

    PubMed Central

    Wu, Yicun; Dai, Jin; Zhang, Weilin; Yan, Rong; Zhang, Yiwen; Ruan, Changgeng; Dai, Kesheng

    2014-01-01

    Arsenic trioxide (ATO), one of the oldest drugs in both Western and traditional Chinese medicine, has become an effective anticancer drug, especially in the treatment of acute promyelocytic leukemia (APL). However, thrombocytopenia occurred in most of ATO-treated patients with APL or other malignant diseases, and the pathogenesis remains unclear. Here we show that ATO dose-dependently induces depolarization of mitochondrial inner transmembrane potential (ΔΨm), up-regulation of Bax and down-regulation of Bcl-2 and Bcl-XL, caspase-3 activation, and phosphotidylserine (PS) exposure in platelets. ATO did not induce surface expression of P-selectin and PAC-1 binding, whereas, obviously reduced collagen, ADP, and thrombin induced platelet aggregation. ATO dose-dependently induced c-Jun NH2-terminal kinase (JNK) activation, and JNK specific inhibitor dicumarol obviously reduced ATO-induced ΔΨm depolarization in platelets. Clinical therapeutic dosage of ATO was intraperitoneally injected into C57 mice, and the numbers of circulating platelets were significantly reduced after five days of continuous injection. The data demonstrate that ATO induces caspase-dependent apoptosis via JNK activation in platelets. ATO does not incur platelet activation, whereas, it not only impairs platelet function but also reduces circulating platelets in vivo, suggesting the possible pathogenesis of thrombocytopenia in patients treated with ATO. PMID:24466103

  13. Arsenic trioxide induces apoptosis in human platelets via C-Jun NH2-terminal kinase activation.

    PubMed

    Wu, Yicun; Dai, Jin; Zhang, Weilin; Yan, Rong; Zhang, Yiwen; Ruan, Changgeng; Dai, Kesheng

    2014-01-01

    Arsenic trioxide (ATO), one of the oldest drugs in both Western and traditional Chinese medicine, has become an effective anticancer drug, especially in the treatment of acute promyelocytic leukemia (APL). However, thrombocytopenia occurred in most of ATO-treated patients with APL or other malignant diseases, and the pathogenesis remains unclear. Here we show that ATO dose-dependently induces depolarization of mitochondrial inner transmembrane potential (ΔΨm), up-regulation of Bax and down-regulation of Bcl-2 and Bcl-XL, caspase-3 activation, and phosphotidylserine (PS) exposure in platelets. ATO did not induce surface expression of P-selectin and PAC-1 binding, whereas, obviously reduced collagen, ADP, and thrombin induced platelet aggregation. ATO dose-dependently induced c-Jun NH2-terminal kinase (JNK) activation, and JNK specific inhibitor dicumarol obviously reduced ATO-induced ΔΨm depolarization in platelets. Clinical therapeutic dosage of ATO was intraperitoneally injected into C57 mice, and the numbers of circulating platelets were significantly reduced after five days of continuous injection. The data demonstrate that ATO induces caspase-dependent apoptosis via JNK activation in platelets. ATO does not incur platelet activation, whereas, it not only impairs platelet function but also reduces circulating platelets in vivo, suggesting the possible pathogenesis of thrombocytopenia in patients treated with ATO. PMID:24466103

  14. Oxidative stress-mediated intrinsic apoptosis in human promyelocytic leukemia HL-60 cells induced by organic arsenicals

    PubMed Central

    Fan, Xiao-Yang; Chen, Xin-You; Liu, Yu-Jiao; Zhong, Hui-Min; Jiang, Feng-Lei; Liu, Yi

    2016-01-01

    Arsenic trioxide has shown the excellent therapeutic efficiency for acute promyelocytic leukemia. Nowadays, more and more research focuses on the design of the arsenic drugs, especially organic arsenicals, and on the mechanism of the inducing cell death. Here we have synthesized some organic arsenicals with Schiff base structure, which showed a better antitumor activity for three different kinds of cancer cell lines, namely HL-60, SGC 7901 and MCF-7. Compound 2a (2-(((4-(oxoarsanyl)phenyl)imino)methyl)phenol) and 2b (2-methoxy-4-(((4-(oxoarsanyl)phenyl)imino)methyl)phenol) were chosen for further mechanism study due to their best inhibitory activities for HL-60 cells, of which the half inhibitory concentration (IC50) were 0.77 μM and 0.51 μM, respectively. It was illustrated that 2a or 2b primarily induced the elevation of reactive oxygen species, decrease of glutathione level, collapse of mitochondrial membrane potential, release of cytochrome c, activation of Caspase-3 and apoptosis, whereas all of the phenomena can be eliminated by the addition of antioxidants. Therefore, we concluded that compound 2a and 2b can induce the oxidative stress-mediated intrinsic apoptosis in HL-60 cells. Both the simplicity of structure with Schiff base group and the better anticancer efficiency demonstrate that organic arsenicals are worthy of further exploration as a class of potent antitumor drugs. PMID:27432798

  15. Oxidative stress-mediated intrinsic apoptosis in human promyelocytic leukemia HL-60 cells induced by organic arsenicals.

    PubMed

    Fan, Xiao-Yang; Chen, Xin-You; Liu, Yu-Jiao; Zhong, Hui-Min; Jiang, Feng-Lei; Liu, Yi

    2016-01-01

    Arsenic trioxide has shown the excellent therapeutic efficiency for acute promyelocytic leukemia. Nowadays, more and more research focuses on the design of the arsenic drugs, especially organic arsenicals, and on the mechanism of the inducing cell death. Here we have synthesized some organic arsenicals with Schiff base structure, which showed a better antitumor activity for three different kinds of cancer cell lines, namely HL-60, SGC 7901 and MCF-7. Compound 2a (2-(((4-(oxoarsanyl)phenyl)imino)methyl)phenol) and 2b (2-methoxy-4-(((4-(oxoarsanyl)phenyl)imino)methyl)phenol) were chosen for further mechanism study due to their best inhibitory activities for HL-60 cells, of which the half inhibitory concentration (IC50) were 0.77 μM and 0.51 μM, respectively. It was illustrated that 2a or 2b primarily induced the elevation of reactive oxygen species, decrease of glutathione level, collapse of mitochondrial membrane potential, release of cytochrome c, activation of Caspase-3 and apoptosis, whereas all of the phenomena can be eliminated by the addition of antioxidants. Therefore, we concluded that compound 2a and 2b can induce the oxidative stress-mediated intrinsic apoptosis in HL-60 cells. Both the simplicity of structure with Schiff base group and the better anticancer efficiency demonstrate that organic arsenicals are worthy of further exploration as a class of potent antitumor drugs. PMID:27432798

  16. Low concentration of arsenic could induce caspase-3 mediated head kidney macrophage apoptosis with JNK-p38 activation in Clarias batrachus

    SciTech Connect

    Datta, Soma; Mazumder, Shibnath; Ghosh, Debabrata; Dey, Saibal; Bhattacharya, Shelley

    2009-12-15

    We had earlier demonstrated that chronic exposure (30 days) to micro-molar concentration (0.50 muM) of arsenic induced head kidney macrophage (HKM) death in Clarias batrachus. The purpose of the present study is to characterize the nature of HKM death induced by arsenic and elucidate the signal transduction pathways involved in the process. Arsenic-induced HKM death was apoptotic in nature as evident from DNA gel, Annexin V-propidium iodide, Hoechst 33342 staining and TdT-mediated dUTP nick end labeling (TUNEL) assays. Inhibitor studies and immunoblot analyses further demonstrated that arsenic-induced HKM apoptosis involved activation of caspase-3 and cleavage of poly(ADP-ribose) polymerase, a well-characterized caspase-3 substrate. Preincubation with antioxidants N-acetyl-cysteine or dimethyl sulfoxide significantly lowered reactive oxygen species (ROS) levels in arsenic-treated HKM and prevented caspase activation, malondialdehyde formation and HKM apoptosis. Arsenic induced membrane translocation of the NADPH oxidase subunit p47{sup phox}. Preincubation with apocynin and diphenyleneiodonium chloride, both selective inhibitors of NADPH oxidases, prevented p47{sup phox} translocation, ROS production and HKM death. Exposure of HKM to arsenic induced the activation of mitogen-activated protein kinase family (MAPK) proteins including c-Jun NH{sub 2}-terminal protein kinase (JNK) and p38 mitogen-activated protein kinase (p38). Preincubation of HKM with p38 inhibitor SB203580 and JNK inhibitor SP600125 protected the HKM against arsenic-induced apoptosis. We conclude that exposure to micro-molar concentration of arsenic induces ROS generation through the activation of NADPH oxidases, which in turn causes caspase-3 mediated HKM apoptosis. In addition, the study also indicates a role of p38-JNK pathway in arsenic-induced HKM apoptosis in C. batrachus.

  17. Targeting hedgehog signalling by arsenic trioxide reduces cell growth and induces apoptosis in rhabdomyosarcoma.

    PubMed

    Boehme, Karen A; Zaborski, Julian J; Riester, Rosa; Schweiss, Sabrina K; Hopp, Ulrike; Traub, Frank; Kluba, Torsten; Handgretinger, Rupert; Schleicher, Sabine B

    2016-02-01

    Rhabdomyosarcomas (RMS) are soft tissue tumours treated with a combination of surgery and chemotherapy. However, mortality rates remain high in case of recurrences and metastatic disease due to drug resistance and failure to undergo apoptosis. Therefore, innovative approaches targeting specific signalling pathways are urgently needed. We analysed the impact of different hedgehog (Hh) pathway inhibitors on growth and survival of six RMS cell lines using MTS assay, colony formation assay, 3D spheroid cultures, flow cytometry and western blotting. Especially the glioma-associated oncogene family (GLI) inhibitor arsenic trioxide (ATO) effectively reduced viability as well as clonal growth and induced cell death in RMS cell lines of embryonal, alveolar and sclerosing, spindle cell subtype, whereas normal skeletal muscle cells were hardly compromised by ATO. Combination of ATO with itraconazole potentiated the reduction of colony formation and spheroid size. These results show that ATO is a promising substance for treatment of relapsed and refractory RMS by directly targeting GLI transcription factors. The combination with itraconazole or other chemotherapeutic drugs has the opportunity to enforce the treatment efficiency of resistant and recurrent RMS. PMID:26676886

  18. Trivalent methylated arsenical-induced phosphatidylserine exposure and apoptosis in platelets may lead to increased thrombus formation

    SciTech Connect

    Bae, Ok-Nam; Lim, Kyung-Min; Chung, Jin-Ho

    2009-09-01

    Trivalent methylated metabolites of arsenic, monomethylarsonous acid (MMA{sup III}) and dimethylarsinous acid (DMA{sup III}), have been found highly reactive and toxic in various cells and in vivo animal models, suggesting their roles in the arsenic-associated toxicity. However, their effects on cardiovascular system including blood cells, one of the most important targets for arsenic toxicity, remain poorly understood. Here we found that MMA{sup III} and DMA{sup III} could induce procoagulant activity and apoptosis in platelets, which play key roles in the development of various cardiovascular diseases (CVDs) through excessive thrombus formation. In freshly isolated human platelets, treatment of MMA{sup III} resulted in phosphatidylserine (PS) exposure, a hallmark of procoagulant activation, accompanied by distinctive apoptotic features including mitochondrial membrane potential disruption, cytochrome c release, and caspase-3 activation. These procoagulant activation and apoptotic features were found to be mediated by the depletion of protein thiol and intracellular ATP, and flippase inhibition by MMA{sup III}, while the intracellular calcium increase or reactive oxygen species generation was not involved. Importantly, increased platelet procoagulant activity by MMA{sup III} resulted in enhanced blood coagulation and excessive thrombus formation in a rat in vivo venous thrombosis model. DMA{sup III} also induced PS-exposure with apoptotic features mediated by protein thiol depletion, which resulted in enhanced thrombin generation. In summary, we believe that this study provides an important evidence for the role of trivalent methylated arsenic metabolites in arsenic-associated CVDs, giving a novel insight into the role of platelet apoptosis in toxicant-induced cardiovascular toxicity.

  19. [Apoptosis-inducing effect of valproic acid combined with arsenic trioxide on RPMI 8226 cells and its mechanism].

    PubMed

    Wang, Xiao-Ning; Zhang, Mei

    2014-08-01

    This study was aimed to investigate the apoptosis-inducing effect of valproic acid (VPA) combined with arsenic trioxide (ATO) on human multiple myeloma RPMI 8226 cells and its mechanism. The cell proliferation of RPMI 8226 cells was assayed by CCK-8 method. The cell apoptosis were detected by flow cytometry. Semiquantitative RT-PCR and Western blot were applied respectively to detect the mRNA and protein expression level of BCL-2, BAX, caspase-8 and caspase-9 gene. The results showed that both the VPA and ATO inhibited RPMI 8226 cell proliferation. The combination of ATO and VPA has synergistic effect (Q values greater than 1.15). The RPMI 8226 cell apoptosis rate in combined drug group was significantly higher than that in single drug group (P < 0.05). The mRNA and protein expressions of BCL-2 gene in combined drug group decreased, while the mRNA and protein expressions of BAX, caspase-8 and caspase-9 significantly increased, compared with single drug group (P < 0.05) . It is concluded that VPA can enhance the sensitivity of RPMI 8226 cells to ATO-induced apoptosis, which may be associated with decreasing the BCL-2 expression and increasing the BAX, caspase-8 and caspase-9 gene expression. PMID:25130820

  20. Arsenic trioxide induces oxidative stress, DNA damage, and mitochondrial pathway of apoptosis in human leukemia (HL-60) cells

    PubMed Central

    2014-01-01

    Background Acute promyelocytic leukemia (APL) is a subtype of acute myeloid leukemia (AML), which accounts for approximately 10% of all acute myloid leukemia cases. It is a blood cancer that is formed by chromosomal mutation. Each year in the United States, APL affects about 1,500 patients of all age groups and causes approximately 1.2% of cancer deaths. Arsenic trioxide (ATO) has been used successfully for treatment of APL patients, and both induction and consolidated therapy have resulted in complete remission. Recently published studies from our laboratory have demonstrated that ATO pharmacology as an anti-leukemic drug is associated with cytotoxic and genotoxic effects in leukemia cells. Methods In the present study, we further investigated the detailed molecular mechanism of ATO-mediated intrinsic pathway of apoptosis; using HL-60 cells as a test model. Oxidative stress was assessed by spectrophotometric measurements of MDA and GSH levels while genotoxicity was determined by single cell gel electrophoresis (Comet assay). Apoptosis pathway was analyzed by Western blot analysis of Bax, Bcl2 and caspase 3 expression, as well as immunocytochemistry and confocal imaging of Bax and Cyt c translocation and mitochondrial membrane potential depolarization. Results ATO significantly (p < 0.05) induces oxidative stress, DNA damage, and caspase 3 activityin HL-60 cells in a dose-dependent manner. It also activated the intrinsic pathway of apoptosis by significantly modulating (p < 0.05) the expression and translocation of apoptotic molecules and decreasing the mitochondrial membrane potential in leukemia cells. Conclusion Taken together, our research demonstrated that ATO induces mitochondrial pathway of apoptosis in HL-60 cells. This apoptotic signaling is modulated via oxidative stress, DNA damage, and change in mitochondrial membrane potential, translocation and upregulation of apoptotic proteins leading programmed cell death. PMID:24887205

  1. TG-interacting factor transcriptionally induced by AKT/FOXO3A is a negative regulator that antagonizes arsenic trioxide-induced cancer cell apoptosis

    SciTech Connect

    Liu, Zi-Miao; Tseng, Hong-Yu; Cheng, Ya-Ling; Yeh, Bi-Wen; Wu, Wen-Jeng; Huang, Huei-Sheng

    2015-05-15

    Arsenic trioxide (ATO) is a multi-target drug approved by the Food and Drug Administration as the first-line chemotherapeutic agent for the treatment of acute promyelocytic leukemia. In addition, several clinical trials are being conducted with arsenic-based drugs for the treatment of other hematological malignancies and solid tumors. However, ATO's modest clinical efficacy on some cancers, and potential toxic effects on humans have been reported. Determining how best to reduce these adverse effects while increasing its therapeutic efficacy is obviously a critical issue. Previously, we demonstrated that the JNK-induced complex formation of phosphorylated c-Jun and TG-interacting factor (TGIF) antagonizes ERK-induced cyclin-dependent kinase inhibitor CDKN1A (p21{sup WAF1/CIP1}) expression and resultant apoptosis in response to ATO in A431 cells. Surprisingly, at low-concentrations (0.1–0.2 μM), ATO increased cellular proliferation, migration and invasion, involving TGIF expression, however, at high-concentrations (5–20 μM), ATO induced cell apoptosis. Using a promoter analysis, TGIF was transcriptionally regulated by ATO at the FOXO3A binding site (− 1486 to − 1479 bp) via the c-Src/EGFR/AKT pathway. Stable overexpression of TGIF promoted advancing the cell cycle into the S phase, and attenuated 20 μM ATO-induced apoptosis. Furthermore, blockage of the AKT pathway enhanced ATO-induced CDKN1A expression and resultant apoptosis in cancer cells, but overexpression of AKT1 inhibited CDKN1A expression. Therefore, we suggest that TGIF is transcriptionally regulated by the c-Src/EGFR/AKT pathway, which plays a role as a negative regulator in antagonizing ATO-induced CDKN1A expression and resultant apoptosis. Suppression of these antagonistic effects might be a promising therapeutic strategy toward improving clinical efficacy of ATO. - Highlights: • ATO-induced biphasic survival responses of cancer cells depend on low- or high-concentrations. • TGIF mediates

  2. Down-regulation of Mcl-1 through GSK-3β activation contributes to arsenic trioxide-induced apoptosis in acute myeloid leukemia cells

    PubMed Central

    Wang, Rui; Xia, Lijuan; Gabrilove, Janice; Waxman, Samuel; Jing, Yongkui

    2012-01-01

    Arsenic trioxide (ATO) induces disease remission in acute promyelocytic leukemia (APL) patients, but not in non-APL acute myeloid leukemia (AML) patients. ATO at therapeutic concentrations (1-2 μM) induce APL NB4, but not non-APL HL-60, cells to undergo apoptosis through the mitochondrial pathway. The role of antiapoptotic protein Mcl-1 in ATO-induced apoptosis was determined. The levels of Mcl-1 were decreased in NB4, but not in HL-60, cells after ATO treatment through proteasomal degradation. Both GSK3β inhibitor SB216763 and siRNA blocked ATO-induced Mcl-1 reduction as well as attenuated ATO-induced apoptosis in NB4 cells. Silencing Mcl-1 sensitized HL-60 cells to ATO-induced apoptosis. Both ERK and AKT inhibitors decreased Mcl-1 levels and enhanced ATO-induced apoptosis in HL-60 cells. Sorafenib, a Raf inhibitor, activated GSK3β by inhibiting its phosphorylation, decreased Mcl-1 levels, and decreased intracellular glutathione levels in HL-60 cells. Sorafenib plus ATO augmented ROS production and apoptosis induction in HL-60 cells and in primary AML cells. These results indicate that ATO induces Mcl-1 degradation through activation of GSK3β in APL cells and provide a rationale for utilizing ATO in combination with sorafenib for the treatment of non-APL AML patients. PMID:22751450

  3. Realgar (As4S4) nanoparticles and arsenic trioxide (As2O3) induced autophagy and apoptosis in human melanoma cells in vitro.

    PubMed

    Pastorek, M; Gronesova, P; Cholujova, D; Hunakova, L; Bujnakova, Z; Balaz, P; Duraj, J; Lee, T C; Sedlak, J

    2014-01-01

    The aim of the present study was to compare the effect of realgar nanoparticles and arsenic trioxide (ATO) on viability, DNA damage, proliferation, autophagy and apoptosis in the human melanoma cell lines BOWES and A375. The application of various flow cytometric methods for measurements cell viability, DNA cell cycle, mitochondrial potential, lysosomal activity, and intracellular content of glutathione was used. In addition, quantitative PCR, western blotting and multiplex bead array analyses were applied for evaluation of redox stress, autophagic flux, and cell signaling alterations.The results showed that realgar treatment of studied cells caused modulation of cell proliferation, induced a block in G2/M phase of the cell cycle and altered phosphorylation of IκB, Akt, ERK1/2, p38, and JNK kinases, as well as decreased mitochondrial membrane potential. Additionally, it appeared that induction of cell death by both realgar and ATO was dose-dependent, when lower (0.3 µM) dosage increased lysosomal activity and induced autophagy and higher (1.25 µM) concentration resulted in the appearance of apoptosis, while pan-caspase inhibitor attenuated more efficiently realgar- than ATO-induced cell death. Furthermore, low concentrations of ATO and realgar nanoparticles increased the content of intracellular glutathione and elevated γ-H2AX expression confirmed DNA damage preferentially at higher concentrations of both drugs used. Further analysis revealed slight differences in time-dependent phosphorylation pattern due to both realgar and ATO treatments, while significant differences were noticed between cell lines. In conclusion, realgar nanoparticles and ATO treatment induced dose-dependent activation of autophagy and apoptosis in both melanoma cell lines, when autophagy flux was determined at lower drug concentrations and the switch to apoptosis occurred at higher concentrations of both arsenic forms. PMID:25150315

  4. Gene expression profiling analysis reveals arsenic-induced cell cycle arrest and apoptosis in p53-proficient and p53-deficient cells through differential gene pathways

    SciTech Connect

    Yu Xiaozhong Robinson, Joshua F.; Gribble, Elizabeth; Hong, Sung Woo; Sidhu, Jaspreet S.; Faustman, Elaine M.

    2008-12-15

    Arsenic (As) is a well-known environmental toxicant and carcinogen as well as an effective chemotherapeutic agent. The underlying mechanism of this dual capability, however, is not fully understood. Tumor suppressor gene p53, a pivotal cell cycle checkpoint signaling protein, has been hypothesized to play a possible role in mediating As-induced toxicity and therapeutic efficiency. In this study, we found that arsenite (As{sup 3+}) induced apoptosis and cell cycle arrest in a dose-dependent manner in both p53{sup +/+} and p53{sup -/-} mouse embryonic fibroblasts (MEFs). There was, however, a distinction between genotypes in the apoptotic response, with a more prominent induction of caspase-3 in the p53{sup -/-} cells than in the p53{sup +/+} cells. To examine this difference further, a systems-based genomic analysis was conducted comparing the critical molecular mechanisms between the p53 genotypes in response to As{sup 3+}. A significant alteration in the Nrf2-mediated oxidative stress response pathway was found in both genotypes. In p53{sup +/+} MEFs, As{sup 3+} induced p53-dependent gene expression alterations in DNA damage and cell cycle regulation genes. However, in the p53{sup -/-} MEFs, As{sup 3+} induced a significant up-regulation of pro-apoptotic genes (Noxa) and down-regulation of genes in immune modulation. Our findings demonstrate that As-induced cell death occurs through a p53-independent pathway in p53 deficient cells while apoptosis induction occurs through p53-dependent pathway in normal tissue. This difference in the mechanism of apoptotic responses between the genotypes provides important information regarding the apparent dichotomy of arsenic's dual mechanisms, and potentially leads to further advancement of its utility as a chemotherapeutic agent.

  5. Effect of arsenic, cadmium and lead on the induction of apoptosis of normal human mononuclear cells

    PubMed Central

    DE LA FUENTE, H; PORTALES-PÉREZ, D; BARANDA, L; DÍAZ-BARRIGA, F; SAAVEDRA-ALANÍS, V; LAYSECA, E; GONZÁLEZ-AMARO, R

    2002-01-01

    The aim of this work was to investigate the effect of cadmium, lead and arsenic on the apoptosis of human immune cells. Peripheral blood mononuclear cells (MNC) were incubated with increasing concentrations of these metals and then cellular apoptosis was determined by flow cytometry and by DNA electrophoresis. We found that arsenic induced a significant level of apoptosis at 15 μm after 48h of incubation. Cadmium had a similar effect, but at higher concentrations (65 μm). In addition, cadmium exerted a cytotoxic effect on MNC that seemed to be independent of the induction of apoptosis. In contrast, concentrations of lead as high as 500 μm were nontoxic and did not induce a significant degree of apoptosis. Additional experiments showed that arsenic at concentrations as low as 1·0 μm had a significant pro-apoptotic effect when cells were cultured in the presence of this pollutant for more than 72. Non-T cells were more susceptible than T lymphocytes to the effect of arsenic and cadmium. Interestingly, MNC from children chronically exposed to arsenic showed a high basal rate of apoptosis and a diminished in vitro sensibility to this metalloid. Our results indicate that both arsenic and cadmium are able to induce apoptosis of lymphoid cells, and suggest that this phenomenon may contribute to their immunotoxic effect in vivo. PMID:12100024

  6. Arsenic trioxide and all-trans retinoic acid target NPM1 mutant oncoprotein levels and induce apoptosis in NPM1-mutated AML cells.

    PubMed

    Martelli, Maria Paola; Gionfriddo, Ilaria; Mezzasoma, Federica; Milano, Francesca; Pierangeli, Sara; Mulas, Floriana; Pacini, Roberta; Tabarrini, Alessia; Pettirossi, Valentina; Rossi, Roberta; Vetro, Calogero; Brunetti, Lorenzo; Sportoletti, Paolo; Tiacci, Enrico; Di Raimondo, Francesco; Falini, Brunangelo

    2015-05-28

    Nucleophosmin (NPM1) mutations represent an attractive therapeutic target in acute myeloid leukemia (AML) because they are common (∼30% AML), stable, and behave as a founder genetic lesion. Oncoprotein targeting can be a successful strategy to treat AML, as proved in acute promyelocytic leukemia by treatment with all-trans retinoic acid (ATRA) plus arsenic trioxide (ATO), which degrade the promyelocytic leukemia (PML)-retinoic acid receptor fusion protein. Adjunct of ATRA to chemotherapy was reported to be beneficial for NPM1-mutated AML patients. Leukemic cells with NPM1 mutation also showed sensibility to ATO in vitro. Here, we explore the mechanisms underlying these observations and show that ATO/ATRA induce proteasome-dependent degradation of NPM1 leukemic protein and apoptosis in NPM1-mutated AML cell lines and primary patients' cells. We also show that PML intracellular distribution is altered in NPM1-mutated AML cells and reverted by arsenic through oxidative stress induction. Interestingly, similarly to what was described for PML, oxidative stress also mediates ATO-induced degradation of the NPM1 mutant oncoprotein. Strikingly, NPM1 mutant downregulation by ATO/ATRA was shown to potentiate response to the anthracyclin daunorubicin. These findings provide experimental evidence for further exploring ATO/ATRA in preclinical NPM1-mutated AML in vivo models and a rationale for exploiting these compounds in chemotherapeutic regimens in clinics. PMID:25795919

  7. Protective Role of Taurine against Arsenic-Induced Mitochondria-Dependent Hepatic Apoptosis via the Inhibition of PKCδ-JNK Pathway

    PubMed Central

    Das, Joydeep; Ghosh, Jyotirmoy; Manna, Prasenjit; Sil, Parames C.

    2010-01-01

    Background Oxidative stress-mediated hepatotoxic effect of arsenic (As) is mainly due to the depletion of glutathione (GSH) in liver. Taurine, on the other hand, enhances intracellular production of GSH. Little is known about the mechanism of the beneficial role of taurine in As-induced hepatic pathophysiology. Therefore, in the present study we investigated its beneficial role in As-induced hepatic cell death via mitochondria-mediated pathway. Methodology/Principal Findings Rats were exposed to NaAsO2 (2 mg/kg body weight for 6 months) and the hepatic tissue was used for oxidative stress measurements. In addition, the pathophysiologic effect of NaAsO2 (10 µM) on hepatocytes was evaluated by determining cell viability, mitochondrial membrane potential and ROS generation. As caused mitochondrial injury by increased oxidative stress and reciprocal regulation of Bcl-2, Bcl-xL/Bad, Bax, Bim in association with increased level of Apaf-1, activation of caspase 9/3, cleavage of PARP protein and ultimately led to apoptotic cell death. In addition, As markedly increased JNK and p38 phosphorylation with minimal disturbance of ERK. Pre-exposure of hepatocytes to a JNK inhibitor SP600125 prevented As-induced caspase-3 activation, ROS production and loss in cell viability. Pre-exposure of hepatocytes to a p38 inhibitor SB2035, on the other hand, had practically no effect on these events. Besides, As activated PKCδ and pre-treatment of hepatocytes with its inhibitor, rottlerin, suppressed the activation of JNK indicating that PKCδ is involved in As-induced JNK activation and mitochondrial dependent apoptosis. Oral administration of taurine (50 mg/kg body weight for 2 weeks) both pre and post to NaAsO2 exposure or incubation of the hepatocytes with taurine (25 mM) were found to be effective in counteracting As-induced oxidative stress and apoptosis. Conclusions/Significance Results indicate that taurine treatment improved As-induced hepatic damages by inhibiting PKC

  8. Gene expression profiling analysis reveals arsenic-induced cell cycle arrest and apoptosis in p53-proficient and p53-deficient cells through differential gene pathways

    PubMed Central

    Yu, Xiaozhong; Robinson, Joshua F.; Gribble, Elizabeth; Hong, Sung Woo; Sidhu, Jaspreet S; Faustman, Elaine M

    2008-01-01

    Arsenic (As) is a well-known environmental toxicant and carcinogen as well as an effective chemotherapeutic agent. The underlying mechanism of this dual capability, however, is not fully understood. Tumor suppressor gene p53, a pivotal cell cycle checkpoint signaling protein, has been hypothesized to play a possible role in mediating As-induced toxicity and therapeutic efficiency. In this study, we found that arsenite (As3+) induced apoptosis and cell cycle arrest in a dose-dependent manner in both p53+/+ and p53−/− mouse embryonic fibroblasts (MEFs). There was, however, a distinction between genotypes in the apoptotic response, with a more prominent induction of caspase-3 in the p53−/− cells than in the p53+/+ cells. To examine this difference further, a systems-based genomic analysis was conducted comparing the critical molecular mechanisms between the p53 genotypes in response to As3+. A significant alteration in the Nrf2-mediated oxidative stress response pathway were found in both genotypes. In p53+/+ MEFs, As3+ induced p53-dependent gene expression alterations in DNA damage and cell cycle regulation genes. However, in the p53−/− MEFs, As3+ induced a significant up-regulation of pro-apoptotic genes (Noxa) and down-regulation of genes in immune modulation. Our findings demonstrate that As-induced cell death occurs through a p53-independent pathway in p53 deficient cells while apoptosis induction occurs through p53-dependent pathway in normal tissue. This difference in the mechanism of apoptotic responses between the genotypes provides important information regarding the apparent dichotomy of arsenic’s dual mechanisms, and potentially leads to further advancement of its utility as a chemotherapeutic agent. PMID:18929588

  9. Arsenic Trioxide Induces Apoptosis and Incapacitates Proliferation and Invasive Properties of U87MG Glioblastoma Cells through a Possible NF-κB-Mediated Mechanism.

    PubMed

    Ghaffari, Seyed H; Yousefi, Meysam; Dizaji, Majid Zaki; Momeny, Majid; Bashash, Davood; Zekri, Ali; Alimoghaddam, Kamran; Ghavamzadeh, Ardeshir

    2016-01-01

    Identification of novel therapeutics in glioblastoma remains crucial due to the devastating and infiltrative capacity of this malignancy. The current study was aimed to appraise effect of arsenic trioxide (ATO) in U87MG cells. The results demonstrated that ATO induced apoptosis and impeded proliferation of U87MG cells in a dosedependent manner and also inhibited classical NF-κB signaling pathway. ATO further upregulated expression of Bax as an important proapoptotic target of NF-κB and also inhibited mRNA expression of survivin, c-Myc and hTERT and suppressed telomerase activity. Moreover, ATO significantly increased adhesion of U87MG cells and also diminished transcription of NF-κB down-stream targets involved in cell migration and invasion, including cathepsin B, uPA, MMP-2, MMP-9 and MMP-14 and suppressed proteolytic activity of cathepsin B, MMP-2 and MMP-9, demonstrating a possible mechanism of ATO effect on a well-known signaling in glioblastoma dissemination. Taken together, here we suggest that ATO inhibits survival and invasion of U87MG cells possibly through NF-κB-mediated inhibition of survivin and telomerase activity and NF-κB-dependent suppression of cathepsin B, MMP-2 and MMP-9. PMID:27039805

  10. MECHANISMS OF ARSENICAL INDUCED MALFORMATIONS

    EPA Science Inventory

    Our research uses the whole embryo culture system to expose mouse embryos to arsenic at the neurulation stage of development (This stage of development is most susceptible to arsenical-induced defects). This includes studies to assess the distribution of cells in the cell cycle a...

  11. Curcumin reduces the expression of survivin, leading to enhancement of arsenic trioxide-induced apoptosis in myelodysplastic syndrome and leukemia stem-like cells.

    PubMed

    Zeng, Yingjian; Weng, Guangyang; Fan, Jiaxin; Li, Zhangqiu; Wu, Jianwei; Li, Yuanming; Zheng, Rong; Xia, Pingfang; Guo, Kunyuan

    2016-09-01

    Low response, treatment-related complications and relapse due to the low sensitivity of myelodysplastic syndrome (MDS) and leukemia stem cells (LSCs) or pre‑LSCs to arsenic trioxide (ATO), represent the main problems following treatment with ATO alone in patients with MDS. To solve these problems, a chemosensitization agent can be applied to increase the susceptibility of these cells to ATO. Curcumin (CUR), which possesses a wide range of anticancer activities, is a commonly used chemosensitization agent for various types of tumors, including hematopoietic malignancies. In the present study, we investigated the cytotoxic effects and potential mechanisms in MDS-SKM-1 and leukemia stem-like KG1a cells treated with CUR and ATO alone or in combination. CUR and ATO exhibited growth inhibition detected by MTT assays and apoptosis analyzed by Annexin V/PI analyses in both SKM-1 and KG1a cells. Apoptosis of SKM-1 and KG1a cells determined by Annexin V/PI was significantly enhanced in the combination groups compared with the groups treated with either agent alone. Further evaluation was performed by western blotting for two hallmark markers of apoptosis, caspase-3 and cleaved-PARP. Co-treatment of the cells with CUR and ATO resulted in significant synergistic effects. In SKM-1 and KG1a cells, 31 and 13 proteins analyzed by protein array assays were modulated, respectively. Notably, survivin protein expression levels were downregulated in both cell lines treated with CUR alone and in combination with ATO, particularly in the latter case. Susceptibility to apoptosis was significantly increased in SKM-1 and KG1a cells treated with siRNA-survivin and ATO. These results suggested that CUR increased the sensitivity of SKM-1 and KG1a cells to ATO by downregulating the expression of survivin. PMID:27430728

  12. Curcumin reduces the expression of survivin, leading to enhancement of arsenic trioxide-induced apoptosis in myelodysplastic syndrome and leukemia stem-like cells

    PubMed Central

    Zeng, Yingjian; Weng, Guangyang; Fan, Jiaxin; Li, Zhangqiu; Wu, Jianwei; Li, Yuanming; Zheng, Rong; Xia, Pingfang; Guo, Kunyuan

    2016-01-01

    Low response, treatment-related complications and relapse due to the low sensitivity of myelodysplastic syndrome (MDS) and leukemia stem cells (LSCs) or pre-LSCs to arsenic trioxide (ATO), represent the main problems following treatment with ATO alone in patients with MDS. To solve these problems, a chemosensitization agent can be applied to increase the susceptibility of these cells to ATO. Curcumin (CUR), which possesses a wide range of anticancer activities, is a commonly used chemosensitization agent for various types of tumors, including hematopoietic malignancies. In the present study, we investigated the cytotoxic effects and potential mechanisms in MDS-SKM-1 and leukemia stem-like KG1a cells treated with CUR and ATO alone or in combination. CUR and ATO exhibited growth inhibition detected by MTT assays and apoptosis analyzed by Annexin V/PI analyses in both SKM-1 and KG1a cells. Apoptosis of SKM-1 and KG1a cells determined by Annexin V/PI was significantly enhanced in the combination groups compared with the groups treated with either agent alone. Further evaluation was performed by western blotting for two hallmark markers of apoptosis, caspase-3 and cleaved-PARP. Co-treatment of the cells with CUR and ATO resulted in significant synergistic effects. In SKM-1 and KG1a cells, 31 and 13 proteins analyzed by protein array assays were modulated, respectively. Notably, survivin protein expression levels were downregulated in both cell lines treated with CUR alone and in combination with ATO, particularly in the latter case. Susceptibility to apoptosis was significantly increased in SKM-1 and KG1a cells treated with siRNA-survivin and ATO. These results suggested that CUR increased the sensitivity of SKM-1 and KG1a cells to ATO by downregulating the expression of survivin. PMID:27430728

  13. Arsenic trioxide mediates HAPI microglia inflammatory response and subsequent neuron apoptosis through p38/JNK MAPK/STAT3 pathway.

    PubMed

    Mao, Jiamin; Yang, Jianbing; Zhang, Yan; Li, Ting; Wang, Cheng; Xu, Lingfei; Hu, Qiaoyun; Wang, Xiaoke; Jiang, Shengyang; Nie, Xiaoke; Chen, Gang

    2016-07-15

    Arsenic is a widely distributed toxic metalloid all over the world. Inorganic arsenic species are supposed to affect astrocytic functions and to cause neuron apoptosis in CNS. Microglias are the key cell type involved in innate immune responses in CNS, and microglia activation has been linked to inflammation and neurotoxicity. In this study, using ELISA, we showed that Arsenic trioxide up-regulated the expression and secretion of IL-1β in a dose-dependent manner and a time-dependent manner in cultured HAPI microglia cells. The secretion of IL-1β caused the apoptosis of SH-SY5Y. These pro-inflammatory responses were inhibited by the STAT3 blocker, AG490 and P38/JNK MAPK blockers SB202190, SP600125. Further, Arsenic trioxide exposure could induce phosphorylation and activation of STAT3, and the translocation of STAT3 from the cytosol to the nucleus in this HAPI microglia cell line. Thus, the STAT3 signaling pathway can be activated after Arsenic trioxide treatment. However, P38/JNK MAPK blockers SB202190, SP600125 also obviously attenuated STAT3 activation and transnuclear transport induced by Arsenic trioxide. In concert with these results, we highlighted that the secretion of IL-1β and STAT3 activation induced by Arsenic trioxide can be mediated by elevation of P38/JNK MAPK in HAPI microglia cells and then induced the toxicity of neurons. PMID:27174766

  14. Arsenic trioxide (As(2)O(3)) induces apoptosis and necrosis mediated cell death through mitochondrial membrane potential damage and elevated production of reactive oxygen species in PLHC-1 fish cell line.

    PubMed

    Selvaraj, Vellaisamy; Armistead, Mindy Yeager; Cohenford, Menashi; Murray, Elizabeth

    2013-01-01

    Several environmental pollutants, including metals can induce toxicological effect on aquatic animal species. Most studies to understand the toxicity of arsenic compounds were performed in mammalian cells; however, the study of the arsenic toxicity to the aquatic animals' species, including fish, is limited. So the objective of this study was first to investigate the effects of As(2)O(3) induced toxicity particularly on apoptosis and necrosis mediated cell death in fish cell PLHC-1 as compared to the mechanism of toxicity from known mammalian cell lines, secondly to relate in vitro effects in fish to those demonstrated by in vivo systems. To conduct this study, PLHC-1 cells were exposed to various concentrations of As(2)O(3) (0-100 μM) for 10, 20 and 40 h. The results indicate that As(2)O(3) exposure promoted apoptotic and necrotic mediated cell death in a concentration and time dependent manner. Cell death (apoptotic and necrotic) induced by As(2)O(3) was further confirmed by changes in various phases of cell cycle, DNA fragmentation (necro- comet and apo-comet) in the comet assay, alteration in mitochondrial membrane potential and formation of increased reactive oxygen species (ROS). Apoptotic mediated cell death was confirmed further by observing the increased caspase-3 activity and elevated expression of p53, cytochrome c and Bax proteins levels in the same experimental conditions. PLHC-1 cells were shown to be a good model for evaluating biochemical/cytotoxic effects following exposure to various reference chemicals and environmental contaminants. In vitro data obtained from this study provides a comprehensive approach for the elucidating the actual molecular mechanism for As(2)O(3) induced toxicity particularly apoptosis and necrosis mediated cell death in PLHC-1 cell line. PMID:23121984

  15. Reactive oxygen species-dependent HSP90 protein cleavage participates in arsenical As{sup +3}- and MMA{sup +3}-induced apoptosis through inhibition of telomerase activity via JNK activation

    SciTech Connect

    Shen, S.-C.; Yang, L.-Y.; Lin, H.-Y.; Wu, C.-Y.; Su, T.-H.; Chen, Y.-C.

    2008-06-01

    The effects of six arsenic compounds including As{sup +3}, MMA{sup +3}, DMA{sup +3}, As{sup +5}, MMA{sup +5}, and DMA{sup +5} on the viability of NIH3T3 cells were examined. As{sup +3} and MMA{sup +3}, but not the others, exhibited significant cytotoxic effects in NIH3T3 cells through apoptosis induction. The apoptotic events such as DNA fragmentation and chromosome condensation induced by As{sup +3} and MMA{sup +3} were prevented by the addition of NAC and CAT, and induction of HO-1 gene expression in accordance with cleavage of the HSP90 protein, and suppression of telomerase activity were observed in NIH3T3 cells under As{sup +3} and MMA{sup +3} treatments. An increase in the intracellular peroxide level was examined in As{sup +3}- and MMA{sup +3}-treated NIH3T3 cells, and As{sup +3}- and MMA{sup +3}-induced apoptotic events were blocked by NAC, CAT, and DPI addition. HSP90 inhibitors, GA and RD, significantly attenuated the telomerase activity in NIH3T3 cells with an enhancement of As{sup +3}- and MMA{sup +3}-induced cytotoxicity. Suppression of JNKs significantly inhibited As{sup +3}- and MMA{sup +3}-induced apoptosis by blocking HSP90 protein cleavage and telomerase reduction in NIH3T3 cells. Furthermore, Hb, SnPP, and dexferosamine showed no effect against As{sup +3}- and MMA{sup +3}-induced apoptosis, and overexpression of HO-1 protein or inhibition of HO-1 protein expression did not affect the apoptosis induced by As{sup +3} or MMA{sup +3}. These data provide the first evidence to indicate that apoptosis induced by As{sup +3} and MMA{sup +3} is mediated by an ROS-dependent degradation of HSP90 protein and reduction of telomerase via JNK activation, and HO-1 induction might not be involved.

  16. Role of mitochondria, ROS, and DNA damage in arsenic induced carcinogenesis.

    PubMed

    Lee, Chih-Hung; Yu, Hsin-Su

    2016-01-01

    The International Agency for Research on Cancer (IARC) declared arsenic a class I carcinogen. Arsenic exposure induces several forms of human cancers, including cancers of skin, lung, liver, and urinary bladder. The majority of the arsenic-induced cancers occur in skin. Among these, the most common is Bowen's disease, characterized by epidermal hyperplasia, full layer epidermal dysplasia, leading to intraepidermal carcinoma as well as apoptosis, and moderate dermal infiltrates, which require the participation of mitochondria. The exact mechanism underlying arsenic induced carcinogenesis remains unclear, although increased reactive oxidative stresses, leading to chromosome abnormalities and uncontrolled growth, and aberrant immune regulations might be involved. Here, we highlight how increased mitochondrial biogenesis and oxidative stress lead to mitochondrial DNA damage and mutation in arsenic induced cancers. We also provide therapeutic rationale for targeting mitochondria in the treatment of arsenic induced cancers. PMID:27100709

  17. 2-Deoxy-D-glucose cooperates with arsenic trioxide to induce apoptosis in leukemia cells: involvement of IGF-1R-regulated Akt/mTOR, MEK/ERK and LKB-1/AMPK signaling pathways.

    PubMed

    Estañ, María Cristina; Calviño, Eva; de Blas, Elena; Boyano-Adánez, María del Carmen; Mena, Maria Luz; Gómez-Gómez, Milagros; Rial, Eduardo; Aller, Patricio

    2012-12-15

    While the anti-tumor efficacy of 2-deoxy-D-glucose (2-DG) is normally low in monotherapy, it may represent a valuable radio- and chemo-sensitizing agent. We here demonstrate that 2-10 mM 2-DG cooperates with arsenic trioxide (ATO) and other antitumor drugs to induce apoptosis in human myeloid leukemia cell lines. Using ATO and HL60 as drug and cell models, respectively, we observed that 2-DG/ATO combination activates the mitochondrial apoptotic pathway, as indicated by Bid-, and Bax-regulated cytochrome c and Omi/HtrA2 release, XIAP down-regulation, and caspase-9/-3 pathway activation. 2-DG neither causes oxidative stress nor increases ATO uptake, but causes inner mitochondria membrane permeabilization as well as moderate ATP depletion, which nevertheless do not satisfactorily explain the pro-apoptotic response. Surprisingly 2-DG causes cell line-specific decrease in LKB-1/AMPK phosphorylation/activation, and also causes Akt/mTOR/p70S6K and MEK/ERK activation, which is prevented by co-treatment with ATO. The use of kinase-specific pharmacologic inhibitors and/or siRNAs reveals that apoptosis is facilitated by AMPK inactivation and restrained by Akt and ERK activation, and that Akt and ERK activation mediates AMPK inhibition. Finally, 2-DG stimulates IGF-1R phosphorylation/activation, and co-treatment with IGF-1R inhibitor prevents 2-DG effects on Akt, ERK and AMPK, and facilitates 2-DG-provoked apoptosis. In summary 2-DG elicits IGF-1R-mediated AMPK inactivation and Akt and ERK activation, which facilitates or restrain apoptosis, respectively. 2-DG-provoked AMPK inactivation increases the apoptotic efficacy of ATO, while in turn ATO-provoked Akt and ERK inactivation may increase the efficacy of 2-DG as anti-tumor drug. PMID:23041229

  18. Unraveling the mechanism of neuroprotection of curcumin in arsenic induced cholinergic dysfunctions in rats

    SciTech Connect

    Srivastava, Pranay; Yadav, Rajesh S.; Chandravanshi, Lalit P.; Shukla, Rajendra K.; Dhuriya, Yogesh K.; Chauhan, Lalit K.S.; Dwivedi, Hari N.; Pant, Aditiya B.; Khanna, Vinay K.

    2014-09-15

    Earlier, we found that arsenic induced cholinergic deficits in rat brain could be protected by curcumin. In continuation to this, the present study is focused to unravel the molecular mechanisms associated with the protective efficacy of curcumin in arsenic induced cholinergic deficits. Exposure to arsenic (20 mg/kg body weight, p.o) for 28 days in rats resulted to decrease the expression of CHRM2 receptor gene associated with mitochondrial dysfunctions as evident by decrease in the mitochondrial membrane potential, activity of mitochondrial complexes and enhanced apoptosis both in the frontal cortex and hippocampus in comparison to controls. The ultrastructural images of arsenic exposed rats, assessed by transmission electron microscope, exhibited loss of myelin sheath and distorted cristae in the mitochondria both in the frontal cortex and hippocampus as compared to controls. Simultaneous treatment with arsenic (20 mg/kg body weight, p.o) and curcumin (100 mg/kg body weight, p.o) for 28 days in rats was found to protect arsenic induced changes in the mitochondrial membrane potential and activity of mitochondrial complexes both in frontal cortex and hippocampus. Alterations in the expression of pro- and anti-apoptotic proteins and ultrastructural damage in the frontal cortex and hippocampus following arsenic exposure were also protected in rats simultaneously treated with arsenic and curcumin. The data of the present study reveal that curcumin could protect arsenic induced cholinergic deficits by modulating the expression of pro- and anti-apoptotic proteins in the brain. More interestingly, arsenic induced functional and ultrastructural changes in the brain mitochondria were also protected by curcumin. - Highlights: • Neuroprotective mechanism of curcumin in arsenic induced cholinergic deficits studied • Curcumin protected arsenic induced enhanced expression of stress markers in rat brain • Arsenic compromised mitochondrial electron transport chain protected

  19. Arsenic moiety in gallium arsenide is responsible for neuronal apoptosis and behavioral alterations in rats

    SciTech Connect

    Flora, Swaran J.S. Bhatt, Kapil; Mehta, Ashish

    2009-10-15

    Gallium arsenide (GaAs), an intermetallic semiconductor finds widespread applications in high frequency microwave and millimeter wave, and ultra fast supercomputers. Extensive use of GaAs has led to increased exposure to humans working in semiconductor industry. GaAs has the ability to dissociate into its constitutive moieties at physiological pH and might be responsible for the oxidative stress. The present study was aimed at evaluating, the principle moiety (Ga or As) in GaAs to cause neurological dysfunction based on its ability to cause apoptosis, in vivo and in vitro and if this neuronal dysfunction translated to neurobehavioral changes in chronically exposed rats. Result indicated that arsenic moiety in GaAs was mainly responsible for causing oxidative stress via increased reactive oxygen species (ROS) and nitric oxide (NO) generation, both in vitro and in vivo. Increased ROS further caused apoptosis via mitochondrial driven pathway. Effects of oxidative stress were also confirmed based on alterations in antioxidant enzymes, GPx, GST and SOD in rat brain. We noted that ROS induced oxidative stress caused changes in the brain neurotransmitter levels, Acetylcholinesterase and nitric oxide synthase, leading to loss of memory and learning in rats. The study demonstrates for the first time that the slow release of arsenic moiety from GaAs is mainly responsible for oxidative stress induced apoptosis in neuronal cells causing behavioral changes.

  20. Epoxyeicosatrienoic acids attenuate reactive oxygen species level, mitochondrial dysfunction, caspase activation, and apoptosis in carcinoma cells treated with arsenic trioxide.

    PubMed

    Liu, Liu; Chen, Chen; Gong, Wei; Li, Yuanjing; Edin, Matthew L; Zeldin, Darryl C; Wang, Dao Wen

    2011-11-01

    Epoxyeicosatrienoic acids (EETs) and the cytochrome P450 epoxygenase CYP2J2 promote tumorogenesis in vivo and in vitro via direct stimulation of tumor cell growth and inhibition of tumor cell apoptosis. Herein, we describe a novel mechanism of inhibition of tumor cell apoptosis by EETs. In Tca-8113 cancer cells, the antileukemia drug arsenic trioxide (ATO) led to the generation of reactive oxygen species (ROS), impaired mitochondrial function, and induced apoptosis. 11,12-EET pretreatment increased expression of the antioxidant enzymes superoxide dismutase and catalase and inhibited ATO-induced apoptosis. 11,12-EET also prevented the ATO-induced activation of p38 mitogen-activated protein kinase, c-Jun NH(2)-terminal kinase, caspase-3, and caspase-9. Therefore, 11,12-EET-pretreatment attenuated the ROS generation, loss of mitochondrial function, and caspase activation observed after ATO treatment. Moreover, the CYP2J2-specific inhibitor compound 26 enhanced arsenic cytotoxicity to a clinically relevant concentration of ATO (1-2 μM). Both the thiol-containing antioxidant, N-acetyl-cysteine, and 11,12-EET reversed the synergistic effect of the two agents. Taken together, these data indicate that 11,12-EET inhibits apoptosis induced by ATO through a mechanism that involves induction of antioxidant proteins and attenuation of ROS-mediated mitochondrial dysfunction. PMID:21846841

  1. Calmodulin antagonists induce platelet apoptosis.

    PubMed

    Wang, Zhicheng; Li, Suping; Shi, Quanwei; Yan, Rong; Liu, Guanglei; Dai, Kesheng

    2010-04-01

    Calmodulin (CaM) antagonists induce apoptosis in various tumor models and inhibit tumor cell invasion and metastasis, thus some of which have been extensively used as anti-cancer agents. In platelets, CaM has been found to bind directly to the cytoplasmic domains of several platelet receptors. Incubation of platelets with CaM antagonists impairs the receptors-related platelet functions. However, it is still unknown whether CaM antagonists induce platelet apoptosis. Here we show that CaM antagonists N-(6-aminohexyl)-5-chloro-1-naphthalene sulfonamide (W7), tamoxifen (TMX), and trifluoperazine (TFP) induce apoptotic events in human platelets, including depolarization of mitochondrial inner transmembrane potential, caspase-3 activation, and phosphatidylserine exposure. CaM antagonists did not incur platelet activation as detected by P-selectin surface expression and PAC-1 binding. However, ADP-, botrocetin-, and alpha-thrombin-induced platelet aggregation, platelet adhesion and spreading on von Willebrand factor surface were significantly reduced in platelets pre-treated with CaM antagonists. Furthermore, cytosolic Ca(2+) levels were obviously elevated by both W7 and TMX, and membrane-permeable Ca(2+) chelator BAPTA-AM significantly reduced apoptotic events in platelets induced by W7. Therefore, these findings indicate that CaM antagonists induce platelet apoptosis. The elevation of the cytosolic Ca(2+) levels may be involved in the regulation of CaM antagonists-induced platelet apoptosis. PMID:20172594

  2. IDENTIFICATION OF INTERSPECIES CONCORDANCE OF MECHANISMS OF ARSENIC-INDUCED BLADDER CANCER

    EPA Science Inventory

    Exposure to arsenic causes cancer by inducing a variety of responses that affect the expression of genes associated with numerous biological pathways leading to altered cell growth and proliferation, signaling, apoptosis and oxidative stress response. Affymetrix GeneChip® arrays ...

  3. Role of reactive oxygen species in arsenic-induced transformation of human lung bronchial epithelial (BEAS-2B) cells

    SciTech Connect

    Zhang, Zhuo; Pratheeshkumar, Poyil; Budhraja, Amit; Son, Young-Ok; Kim, Donghern; Shi, Xianglin

    2015-01-09

    Highlights: • Short term exposure of cells to arsenic causes ROS generation. • Chronical exposure of cells to arsenic causes malignant cell transformation. • Inhibition of ROS generation reduces cell transformation by arsenic. • Arsenic-transformed cells exhibit reduced capacity of generating ROS. • Arsenic-transformed cells exhibit increased levels of antioxidants. - Abstract: Arsenic is an environmental carcinogen, its mechanisms of carcinogenesis remain to be investigated. Reactive oxygen species (ROS) are considered to be important. A previous study (Carpenter et al., 2011) has measured ROS level in human lung bronchial epithelial (BEAS-2B) cells and arsenic-transformed BEAS-2B cells and found that ROS levels were higher in transformed cells than that in parent normal cells. Based on these observations, the authors concluded that cell transformation induced by arsenic is mediated by increased cellular levels of ROS. This conclusion is problematic because this study only measured the basal ROS levels in transformed and parent cells and did not investigate the role of ROS in the process of arsenic-induced cell transformation. The levels of ROS in arsenic-transformed cells represent the result and not the cause of cell transformation. Thus question concerning whether ROS are important in arsenic-induced cell transformation remains to be answered. In the present study, we used expressions of catalase (antioxidant against H{sub 2}O{sub 2}) and superoxide dismutase 2 (SOD2, antioxidant against O{sub 2}{sup ·−}) to decrease ROS level and investigated their role in the process of arsenic-induced cell transformation. Our results show that inhibition of ROS by antioxidant enzymes decreased arsenic-induced cell transformation, demonstrating that ROS are important in this process. We have also shown that in arsenic-transformed cells, ROS generation was lower and levels of antioxidants are higher than those in parent cells, in a disagreement with the previous

  4. Arsenic Trioxide-Induced Mandibular Osteomyelitis.

    PubMed

    Lu, Pei-Chen; Wu, Ju-Hui; Chen, Chun-Ming; Du, Je-Kang

    2015-09-01

    Previously, arsenic was a popular devitalizing agent used to necrotize inflamed dental pulp to lower the pulp sensitivity owing to the unavailability of appropriate anesthesia. However, leakage from the apical foramen, lateral or accessory canals, or cracks in the tooth is common. This can be dangerous because of the reportedly high toxic effects of arsenic in both hard and soft tissues, leading to gingival and osseous necrosis and, consequently, osteomyelitis. Therefore, arsenic can prove fatal for both bones and teeth and is no longer used. We encountered a case involving a 50-year-old man who had developed mandibular osteomyelitis with lower lip paresthesia caused by arsenic trioxide used during endodontic treatment. The patient was treated with appropriate antibiotics, adjunctive hyperbaric oxygen therapy, and adequate surgical debridement. Hyperbaric oxygen therapy can induce neovascularization in necrosed tissues and improve bone and soft tissue healing. At a 4-year follow-up visit, bone healing was observed, with restoration of periodontal health, although the paresthesia had persisted. We describe this case, present a review of the relevant published data, and discuss the possible causes, diagnosis, treatment, and follow-up protocol of mandibular osteomyelitis caused by arsenic trioxide. PMID:25896568

  5. Arsenic-induced Aurora-A activation contributes to chromosome instability and tumorigenesis

    NASA Astrophysics Data System (ADS)

    Wu, Chin-Han; Tseng, Ya-Shih; Yang, Chao-Chun; Kao, Yu-Ting; Sheu, Hamm-Ming; Liu, Hsiao-Sheng

    2013-11-01

    Arsenic may cause serious environmental pollution and is a serious industrial problem. Depending on the dosage, arsenic may trigger the cells undergoing either proliferation or apoptosis-related cell death. Because of lack of the proper animal model to study arsenic induced tumorigenesis, the accurate risk level of arsenic exposure has not been determined. Arsenic shows genotoxic effect on human beings who uptake water contaminated by arsenic. Chromosome aberration is frequently detected in arsenic exposure-related diseases and is associated with increased oxidative stress and decreased DNA repairing activity, but the underlying mechanism remains elusive. Aurora-A is a mitotic kinase, over-expression of Aurora-A leads to centrosome amplification, chromosomal instability and cell transformation. We revealed that Aurora-A is over-expressed in the skin and bladder cancer patients from blackfoot-disease endemic areas. Our cell line studies reveal that arsenic exposure between 0.5 μM and 1 μM for 2-7 days are able to induce Aurora-A expression and activation based on promoter activity, RNA and protein analysis. Aurora-A overexpression further increases the frequency of unsymmetrical chromosome segregation through centrosome amplification followed by cell population accumulated at S phase in immortalized keratinocyte (HaCaT) and uroepithelial cells (E7). Furthermore, Aurora-A over-expression was sustained for 1-4 weeks by chronic treatment of immortalized bladder and skin cells with NaAsO2. Aurora-A promoter methylation and gene amplification was not detected in the long-term arsenic treated E7 cells. Furthermore, the expression level of E2F1 transcription factor (E2F1) is increased in the presence of arsenic, and arsenic-related Aurora-A over-expression is transcriptionally regulated by E2F1. We further demonstrated that overexpression of Aurora-A and mutant Ha-ras or Aurora-A and mutant p53 may act additively to trigger arsenic-related bladder and skin cancer

  6. (-)-Epigallocatechin-3-gallate (EGCG) attenuates arsenic-induced cardiotoxicity in rats.

    PubMed

    Sun, Tao-Li; Liu, Zhi; Qi, Zheng-Jun; Huang, Yong-Pan; Gao, Xiao-Qin; Zhang, Yan-Yan

    2016-07-01

    Chronic arsenic exposure in drinking water is associated with the abnormalities of cardiac tissue. Excessive generation of ROS induced by arsenic has a central role in arsenic-induced cardiotoxicity. (-)-Epigallocatechin-3-gallate (EGCG), the most abundant polyphenol in green tea, possesses a potent antioxidant capacity and exhibits extensive pharmacological activities. This study was aim to evaluate the effect of EGCG on arsenic-induced cardiotoxicity in vivo and in vitro. Treatment with NaAsO2 seriously affected the morphology and ultrastructure of myocardium, and induced cardiac injuries, oxidative stress, intracellular calcium accumulation and apoptosis in rats. In consistent with in vivo study, the injuries, oxidative stress and apoptosis were also observed in NaAsO2-treated H9c2 cells. All of these effects induced by NaAsO2 were attenuated by EGCG. These results suggest EGCG could attenuate NaAsO2-induced cardiotoxicity, and the mechanism may involve its potent antioxidant capacity. PMID:27170490

  7. Arsenic-induced genotoxicity in Nile tilapia (Orechromis niloticus); the role of Spirulina platensis extract.

    PubMed

    Sayed, Alaa El-Din H; Elbaghdady, Heba Allah M; Zahran, Eman

    2015-12-01

    Arsenic (As) is one of the most relevant environmental global single substance toxicants that have long been regarded as a carcinogenic and genotoxic potential. In this respect, we evaluated the cytogenetic effect of arsenic exposure in Nile tilapia (Oreochromis niloticus), in terms of erythrocyte alteration, apoptosis, and induction of micronuclei. Spirulina platensis (SP) is a filamentous cyanobacterium microalgae with potent dietary phytoantioxidant, anti-inflammatory, and anti-cancerous properties supplementation. The protective role of Spirulina as supplementary feeds was studied in Nile tilapia (O. niloticus) against arsenic-induced cytogenotoxicity. Four groups were assigned as control group (no SP or As), As group (exposed to water-born As in the form of NaAsO2 at 7 ppm), SP1 (SP at 7.5% + As at the same level of exposure), and SP2 (SP at 10% + As at the same level of exposure). As-treated group had a significant increase in all cytogenetic analyses including erythrocyte alteration, apoptosis, and induction of micronuclei after 2 weeks with continuous increase in response after 3 weeks. The combined treatment of Spirulina at two different concentrations of 7.5 and 10% had significantly declined the induction of erythrocyte alteration, apoptosis, and micronuclei formation induced by arsenic intoxication. PMID:26573688

  8. Resveratrol protects against arsenic trioxide-induced nephrotoxicity by facilitating arsenic metabolism and decreasing oxidative stress.

    PubMed

    Yu, Meiling; Xue, Jiangdong; Li, Yijing; Zhang, Weiqian; Ma, Dexing; Liu, Lian; Zhang, Zhigang

    2013-06-01

    Arsenic trioxide (As(2)O(3)) is an environmental toxicant and a potent antineoplastic agent. Exposure to arsenic causes renal cancer. Resveratrol is a well-known polyphenolic compound that is reported to reduce As(2)O(3)-induced cardiotoxicity. The present study aimed to investigate the effect of resveratrol on As(2)O(3)-induced nephrotoxicity and arsenic metabolism. Chinese Dragon-Li cats were injected with 1 mg/kg As(2)O(3) on alternate days; resveratrol (3 mg/kg) was administered via the forearm vein 1 h before the As(2)O(3) treatment. On the sixth day, the cats were killed to determine the histological renal damage, renal function, the accumulation of arsenic, and antioxidant activities in the kidney. Urine samples were taken for arsenic speciation. In the resveratrol + As(2)O(3)-treated group, activities of glutathione peroxidase, catalase, and superoxide dismutase, the ratio of reduced glutathione to oxidized glutathione, the total arsenic concentrations, and the percentage of methylated arsenic in urine were significantly increased. The concentrations of renal malondialdehyde, reactive oxygen species, 8-hydroxydeoxyguanosine, serum creatinine, blood urea nitrogen, and renal arsenic accumulation were significantly decreased and reduced renal morphologic injury was observed compared with the As(2)O(3)-treated group. These results demonstrate that resveratrol could significantly scavenge reactive oxygen species, inhibit As(2)O(3)-induced oxidative damage, and significantly attenuate the accumulation of arsenic in renal tissues by facilitating As(2)O(3) metabolism. These data suggest that use of resveratrol as postremission therapy for acute promyelocytic leukemia as well as adjunctive therapy in patients with exposure to arsenic may decrease arsenic nephrotoxicity. PMID:23471352

  9. Molecular features in arsenic-induced lung tumors

    PubMed Central

    2013-01-01

    Arsenic is a well-known human carcinogen, which potentially affects ~160 million people worldwide via exposure to unsafe levels in drinking water. Lungs are one of the main target organs for arsenic-related carcinogenesis. These tumors exhibit particular features, such as squamous cell-type specificity and high incidence among never smokers. Arsenic-induced malignant transformation is mainly related to the biotransformation process intended for the metabolic clearing of the carcinogen, which results in specific genetic and epigenetic alterations that ultimately affect key pathways in lung carcinogenesis. Based on this, lung tumors induced by arsenic exposure could be considered an additional subtype of lung cancer, especially in the case of never-smokers, where arsenic is a known etiological agent. In this article, we review the current knowledge on the various mechanisms of arsenic carcinogenicity and the specific roles of this metalloid in signaling pathways leading to lung cancer. PMID:23510327

  10. Further evidence against a direct genotoxic mode of action for arsenic-induced cancer

    SciTech Connect

    Klein, Catherine B.; Leszczynska, Joanna; Hickey, Christina; Rossman, Toby G.

    2007-08-01

    Arsenic in drinking water, a mixture of arsenite and arsenate, is associated with increased skin and other cancers in Asia and Latin America, but not the United States. Arsenite alone in drinking water does not cause skin cancers in experimental animals; therefore, it is not a complete carcinogen in skin. We recently showed that low concentrations of arsenite enhanced the tumorigenicity of solar UV irradiation in hairless mice, suggesting arsenic cocarcinogenesis with sunlight in skin cancer and perhaps with different carcinogenic partners for lung and bladder tumors. Cocarcinogenic mechanisms could include blocking DNA repair, stimulating angiogenesis, altering DNA methylation patterns, dysregulating cell cycle control, induction of aneuploidy and blocking apoptosis. Arsenicals are documented clastogens but not strong mutagens, with weak mutagenic activity reported at highly toxic concentrations of inorganic arsenic. Previously, we showed that arsenite, but not monomethylarsonous acid (MMA[III]), induced delayed mutagenesis in HOS cells. Here, we report new data on the mutagenicity of the trivalent methylated arsenic metabolites MMA(III) and dimethylarsinous acid [DMA(III)] at the gpt locus in Chinese hamster G12 cells. Both methylated arsenicals seemed mutagenic with apparent sublinear dose responses. However, significant mutagenesis occurred only at highly toxic concentrations of MMA(III). Most mutants induced by MMA(III) and DMA(III) exhibited transgene deletions. Some non-deletion mutants exhibited altered DNA methylation. A critical discussion of cell survival leads us to conclude that clastogenesis occurs primarily at highly cytotoxic arsenic concentrations, casting further doubt as to whether a genotoxic mode of action (MOA) for arsenicals is supportable.

  11. Gut microbiome perturbations induced by bacterial infection affect arsenic biotransformation.

    PubMed

    Lu, Kun; Cable, Peter Hans; Abo, Ryan Phillip; Ru, Hongyu; Graffam, Michelle E; Schlieper, Katherine Ann; Parry, Nicola M A; Levine, Stuart; Bodnar, Wanda M; Wishnok, John S; Styblo, Miroslav; Swenberg, James A; Fox, James G; Tannenbaum, Steven R

    2013-12-16

    Exposure to arsenic affects large human populations worldwide and has been associated with a long list of human diseases, including skin, bladder, lung, and liver cancers, diabetes, and cardiovascular disorders. In addition, there are large individual differences in susceptibility to arsenic-induced diseases, which are frequently associated with different patterns of arsenic metabolism. Several underlying mechanisms, such as genetic polymorphisms and epigenetics, have been proposed, as these factors closely impact the individuals' capacity to metabolize arsenic. In this context, the role of the gut microbiome in directly metabolizing arsenic and triggering systemic responses in diverse organs raises the possibility that perturbations of the gut microbial communities affect the spectrum of metabolized arsenic species and subsequent toxicological effects. In this study, we used an animal model with an altered gut microbiome induced by bacterial infection, 16S rRNA gene sequencing, and inductively coupled plasma mass spectrometry-based arsenic speciation to examine the effect of gut microbiome perturbations on the biotransformation of arsenic. Metagenomics sequencing revealed that bacterial infection significantly perturbed the gut microbiome composition in C57BL/6 mice, which in turn resulted in altered spectra of arsenic metabolites in urine, with inorganic arsenic species and methylated and thiolated arsenic being perturbed. These data clearly illustrated that gut microbiome phenotypes significantly affected arsenic metabolic reactions, including reduction, methylation, and thiolation. These findings improve our understanding of how infectious diseases and environmental exposure interact and may also provide novel insight regarding the gut microbiome composition as a new risk factor of individual susceptibility to environmental chemicals. PMID:24134150

  12. Environmental Arsenic Exposure and Microbiota in Induced Sputum

    PubMed Central

    White, Allison G.; Watts, George S.; Lu, Zhenqiang; Meza-Montenegro, Maria M.; Lutz, Eric A.; Harber, Philip; Burgess, Jefferey L.

    2014-01-01

    Arsenic exposure from drinking water is associated with adverse respiratory outcomes, but it is unknown whether arsenic affects pulmonary microbiota. This exploratory study assessed the effect of exposure to arsenic in drinking water on bacterial diversity in the respiratory tract of non-smokers. Induced sputum was collected from 10 subjects with moderate mean household water arsenic concentration (21.1 ± 6.4 ppb) and 10 subjects with low household water arsenic (2.4 ± 0.8 ppb). To assess microbiota in sputum, the V6 hypervariable region amplicons of bacterial 16s rRNA genes were sequenced using the Ion Torrent Personal Genome Machine. Microbial community differences between arsenic exposure groups were evaluated using QIIME and Metastats. A total of 3,920,441 sequence reads, ranging from 37,935 to 508,787 per sample for 316 chips after QIIME quality filtering, were taxonomically classified into 142 individual genera and five phyla. Firmicutes (22%), Proteobacteria (17%) and Bacteriodetes (12%) were the main phyla in all samples, with Neisseriaceae (15%), Prevotellaceae (12%) and Veillonellacea (7%) being most common at the genus level. Some genera, including Gemella, Lactobacillales, Streptococcus, Neisseria and Pasteurellaceae were elevated in the moderate arsenic exposure group, while Rothia, Prevotella, Prevotellaceae Fusobacterium and Neisseriaceae were decreased, although none of these differences was statistically significant. Future studies with more participants and a greater range of arsenic exposure are needed to further elucidate the effects of drinking water arsenic consumption on respiratory microbiota. PMID:24566055

  13. Arsenic

    MedlinePlus

    Arsenic is a natural element found in soil and minerals. Arsenic compounds are used to preserve wood, as pesticides, and in some industries. Arsenic can get into air, water, and the ground from wind- ...

  14. Arsenic

    MedlinePlus

    ... and minerals. Arsenic compounds are used to preserve wood, as pesticides, and in some industries. Arsenic can ... Breathing sawdust or burning smoke from arsenic-treated wood Living in an area with high levels of ...

  15. Apoptosis inducers in chronic lymphocytic leukemia

    PubMed Central

    Billard, Christian

    2014-01-01

    Chronic lymphocytic leukemia (CLL) is characterized by a typical defect in apoptosis and is still an incurable disease. Numerous apoptosis inducers have been described. These synthetic compounds and natural products (mainly derived from plants) display antileukemic properties in vitro and in vivo and some have even been tested in the clinic in CLL. They act through several different mechanisms. Most of them involve proteins of the Bcl-2 family, which are the key regulators in triggering the mitochondrial pathway of caspase-dependent apoptosis. Thus, the Mcl-1/Noxa axis appeared as a target. Here I overview natural and synthetic apoptosis inducers and their mechanisms of action in CLL cells. Opportunities for developing novel, apoptosis-based therapeutics are presented. PMID:24525395

  16. INDUCTION OF CELL PROLIFERATION AND APOPTOSIS IN HL60 AND HACAT CELLS BY ARSENIC, ARSENATE, AND ARSENIC-CONTAMINATED DRINKING WATER

    EPA Science Inventory

    Induction of cell proliferation and apoptosis in HL-60 and HaCaT cells by arsenite, arsenate and arsenic-contaminated drinking water. T-C. Zhang, M. Schmitt, J. L. Mumford National Research Council, Washington DC and U.S. Environmental Protection Agency, NHEERL, Research Triangle...

  17. Arsenic transformation predisposes human skin keratinocytes to UV-induced DNA damage yet enhances their survival apparently by diminishing oxidant response

    SciTech Connect

    Sun Yang; Kojima, Chikara; Chignell, Colin; Mason, Ronald; Waalkes, Michael P.

    2011-09-15

    Inorganic arsenic and UV, both human skin carcinogens, may act together as skin co-carcinogens. We find human skin keratinocytes (HaCaT cells) are malignantly transformed by low-level arsenite (100 nM, 30 weeks; termed As-TM cells) and with transformation concurrently undergo full adaptation to arsenic toxicity involving reduced apoptosis and oxidative stress response to high arsenite concentrations. Oxidative DNA damage (ODD) is a possible mechanism in arsenic carcinogenesis and a hallmark of UV-induced skin cancer. In the current work, inorganic arsenite exposure (100 nM) did not induce ODD during the 30 weeks required for malignant transformation. Although acute UV-treatment (UVA, 25 J/cm{sup 2}) increased ODD in passage-matched control cells, once transformed by arsenic to As-TM cells, acute UV actually further increased ODD (> 50%). Despite enhanced ODD, As-TM cells were resistant to UV-induced apoptosis. The response of apoptotic factors and oxidative stress genes was strongly mitigated in As-TM cells after UV exposure including increased Bcl2/Bax ratio and reduced Caspase-3, Nrf2, and Keap1 expression. Several Nrf2-related genes (HO-1, GCLs, SOD) showed diminished responses in As-TM cells after UV exposure consistent with reduced oxidant stress response. UV-exposed As-TM cells showed increased expression of cyclin D1 (proliferation gene) and decreased p16 (tumor suppressor). UV exposure enhanced the malignant phenotype of As-TM cells. Thus, the co-carcinogenicity between UV and arsenic in skin cancer might involve adaptation to chronic arsenic exposure generally mitigating the oxidative stress response, allowing apoptotic by-pass after UV and enhanced cell survival even in the face of increased UV-induced oxidative stress and increased ODD. - Highlights: > Arsenic transformation adapted to UV-induced apoptosis. > Arsenic transformation diminished oxidant response. > Arsenic transformation enhanced UV-induced DNA damage.

  18. Specific histone modification responds to arsenic-induced oxidative stress.

    PubMed

    Ma, Lu; Li, Jun; Zhan, Zhengbao; Chen, Liping; Li, Daochuan; Bai, Qing; Gao, Chen; Li, Jie; Zeng, Xiaowen; He, Zhini; Wang, Shan; Xiao, Yongmei; Chen, Wen; Zhang, Aihua

    2016-07-01

    To explore whether specific histone modifications are associated with arsenic-induced oxidative damage, we recruited 138 arsenic-exposed and arsenicosis subjects from Jiaole Village, Xinren County of Guizhou province, China where the residents were exposed to arsenic from indoor coal burning. 77 villagers from Shang Batian Village that were not exposed to high arsenic coal served as the control group. The concentrations of urine and hair arsenic in the arsenic-exposure group were 2.4-fold and 2.1-fold (all P<0.001) higher, respectively, than those of the control group. Global histone modifications in human peripheral lymphocytes (PBLCs) were examined by ELISA. The results showed that altered global levels of H3K18ac, H3K9me2, and H3K36me3 correlated with both urinary and hair-arsenic levels of the subjects. Notably, H3K36me3 and H3K18ac modifications were associated with urinary 8-OHdG (H3K36me3: β=0.16; P=0.042, H3K18ac: β=-0.24; P=0.001). We also found that the modifications of H3K18ac and H3K36me3 were enriched in the promoters of oxidative stress response (OSR) genes in human embryonic kidney (HEK) cells and HaCaT cells, providing evidence that H3K18ac and H3K36me3 modifications mediate transcriptional regulation of OSR genes in response to NaAsO2 treatment. Particularly, we found that reduced H3K18ac modification correlated with suppressed expression of OSR genes in HEK cells with long term arsenic treatment and in PBLCs of all the subjects. Taken together, we reveal a critical role for specific histone modification in response to arsenic-induced oxidative damage. PMID:27068294

  19. BIBR 1532 increases arsenic trioxide-mediated apoptosis in acute promyelocytic leukemia cells: therapeutic potential for APL.

    PubMed

    Bashash, Davood; Ghaffari, Seyed H; Zaker, Farhad; Kazerani, Maryam; Hezave, Kebria; Hassani, Saeed; Rostami, Masomeh; Alimoghaddam, Kamran; Ghavamzadeh, Ardeshir

    2013-09-01

    The current treatment of acute promyelocytic leukemia with arsenic trioxide (ATO) has increased long-lasting complete remissions; however, a proportion of patients continues to die eventually as a result of disease recurrence. In an effort to enhance the effectiveness of the APL treatment, we designed experiments to evaluate the effects of ATO in combination with the lead compound of non-nucleoside inhibitor of telomerase, BIBR 1532. After combined treatments with BIBR 1532 and ATO, decreased cell viability index with a concomitant increase in apoptotic cell death was observed in NB4 leukemic cells. Apoptosis induced by the combined treatments was accompanied by elevated Bax/Bcl-2 molecular ratio and enhanced caspase 3 activation. Our study has also demonstrated that the combined treatment suppressed NB4 cell proliferative capacity and inhibited telomerase activity probably via transcriptional suppression of c-Myc and hTERT. In conclusion, this study may supply insight into the application of this new combination therapy to APL cells intrinsically less sensitive to routine therapies and suggested a novel combination therapy for patients with more aggressive disease; those who may not respond favorably to the arsenic mono-therapy. PMID:23293885

  20. Lysosomal destabilization in p53-induced apoptosis

    PubMed Central

    Yuan, Xi-Ming; Li, Wei; Dalen, Helge; Lotem, Joseph; Kama, Rachel; Sachs, Leo; Brunk, Ulf T.

    2002-01-01

    The tumor suppressor wild-type p53 can induce apoptosis. M1-t-p53 myeloid leukemic cells have a temperature-sensitive p53 protein that changes its conformation to wild-type p53 after transfer from 37°C to 32°C. We have now found that these cells showed an early lysosomal rupture after transfer to 32°C. Mitochondrial damage, including decreased membrane potential and release of cytochrome c, and the appearance of apoptotic cells occurred later. Lysosomal rupture, mitochondrial damage, and apoptosis were all inhibited by the cytokine IL-6. Some other compounds can also inhibit apoptosis induced by p53. The protease inhibitor N-tosyl-l-phenylalanine chloromethyl ketone inhibited the decrease in mitochondrial membrane potential and cytochrome c release, the Ca2+-ATPase inhibitor thapsigargin inhibited only cytochrome c release, and the antioxidant butylated hydroxyanisole inhibited only the decrease in mitochondrial membrane potential. In contrast to IL-6, these other compounds that inhibited some of the later occurring mitochondrial damage did not inhibit the earlier p53-induced lysosomal damage. The results indicate that apoptosis is induced by p53 through a lysosomal-mitochondrial pathway that is initiated by lysosomal destabilization, and that this pathway can be dissected by using different apoptosis inhibitors. These findings on the induction of p53-induced lysosomal destabilization can also help to formulate new therapies for diseases with apoptotic disorders. PMID:11959917

  1. Training-induced apoptosis in skeletal muscle.

    PubMed

    Boffi, F M; Cittar, J; Balskus, G; Muriel, M; Desmaras, E

    2002-09-01

    Apoptosis or programmed cell death is a genetically controlled response of cells to commit suicide and is associated with DNA fragmentation or laddering. The common inducers of apoptosis include Ca2+i and oxygen free radicals/oxidative stress, which are also implicated in the pathogenesis of exercise-induced myopathies. To examine training-induced apoptosis, Thoroughbred horses were subjected to 3 months training programme on a treadmill. At the end of the training programme venous blood samples were taken for a creatine kinase (CK) assay. In addition, muscle biopsy samples were obtained for a membrane lipid peroxidation measurement by malondialdehyde (MDA) assay and for apoptosis detection. Apoptosis was studied by visualising the apoptotic myocytes on the paraffin sections by the modified TUNEL method. DNA laddering was evaluated by subjecting the DNA obtained from the biopsies to 1.5% agarose gel electrophoresis. There was a significant increase (P<0.05) of protein-bound MDA, and a nonsignificant trend (P = 0.14) for the control group to have higher levels of CK compared to the trained group. Under light microscopy, percentage of the TUNEL positive cells was higher (P<0.001) in the training group. This result was corroborated with the findings of DNA fragmentation by gel electrophoresis, which showed higher ladders of DNA band at the same group. In conclusion, these results clearly demonstrate that there is training-induced apoptosis in skeletal muscle. It is probable that apoptosis allows the work/recovery/rebound/supercompensation cycle, when unaccustomed muscle cells activate programmed cell death and are replaced by new and stronger cells, which is the mechanism for training-induced increases in fitness. PMID:12405700

  2. Arsenite induces apoptosis in human mesenchymal stem cells by altering Bcl-2 family proteins and by activating intrinsic pathway

    SciTech Connect

    Yadav, Santosh; Shi Yongli; Wang Feng; Wang He

    2010-05-01

    Purpose: Environmental exposure to arsenic is an important public health issue. The effects of arsenic on different tissues and organs have been intensively studied. However, the effects of arsenic on bone marrow mesenchymal stem cells (MSCs) have not been reported. This study is designed to investigate the cell death process caused by arsenite and its related underlying mechanisms on MSCs. The rationale is that absorbed arsenic in the blood circulation can reach to the bone marrow and may affect the cell survival of MSCs. Methods: MSCs of passage 1 were purchased from Tulane University, grown till 70% confluency level and plated according to the experimental requirements followed by treatment with arsenite at various concentrations and time points. Arsenite (iAs{sup III}) induced cytotoxic effects were confirmed by cell viability and cell cycle analysis. For the presence of canonic apoptosis markers; DNA damage, exposure of intramembrane phosphotidylserine, protein and m-RNA expression levels were analyzed. Results: iAs{sup III} induced growth inhibition, G2-M arrest and apoptotic cell death in MSCs, the apoptosis induced by iAs{sup III} in the cultured MSCs was, via altering Bcl-2 family proteins and by involving intrinsic pathway. Conclusion: iAs{sup III} can induce apoptosis in bone marrow-derived MSCs via Bcl-2 family proteins, regulating intrinsic apoptotic pathway. Due to the multipotency of MSC, acting as progenitor cells for a variety of connective tissues including bone, adipose, cartilage and muscle, these effects of arsenic may be important in assessing the health risk of the arsenic compounds and understanding the mechanisms of arsenic-induced harmful effects.

  3. Sodium nitroprusside induces apoptosis of rabbit chondrocytes

    NASA Astrophysics Data System (ADS)

    Liang, Qian; Wang, Xiao-Ping; Chen, Tong-Sheng

    2013-02-01

    Osteoarthritis (OA) is characterized by a slowly progressing degradation of the matrix and destruction of articular cartilage. Apoptosis of chondrocyte is accounted for the mechanism of OA. Nitric oxide (NO), as a stimulus, has been shown to induce chondrocyte apoptosis by activating the matrix metalloproteinases (MMPs), increasing the expression of cyclooxygenase 2 (COX-2) and the level of prostaglandin E2 (PGE2), inhibiting the proteoglycan synthesis and type II collagen expression. In this study, sodium nitroprusside (SNP) was administered to be the NO donor to explore the mechanism of NO-induced apoptosis of rabbit chondrocytes obtained from six weeks old New Zealand rabbits. CCK-8 assay revealed the inhibitory effect of SNP on cell viability. We used flow cytometry (FCM) to assess the form of cell death by Annexin-V/propidium iodide (PI) double staining, and evaluate the change of mitochondrial membrane potential (ΔΨm). We found that the SNP induced chondrocyte apoptosis in a dose- and time-dependent manner and an observable reduction of ΔΨm. In conclusion, our findings indicate that SNP induces apoptosis of rabbit chondrocytes via a mitochondria-mediated pathway.

  4. Umbelliprenin Induces Apoptosis in CLL Cell Lines

    PubMed Central

    Ziai, Seyed Ali; Gholami, Omid; Iranshahi, Mehrdad; Zamani, Amir Hassan; Jeddi-Tehrani, Mahmood

    2012-01-01

    Chronic lymphocytic leukemia (CLL) remains an incurable disease that requires innovative new approaches to improve therapeutic outcome. Many Ferula species, including F. asa-foetida, synthesize terpenyloxy coumarins. One of these coumarins is umbelliprenin, which has been implicated with induction of apoptosis in some cancer cell lines. In this study induction of apoptosis by umbelliprenin on Jurkat T-CLL and Raji B-CLL cell lines was studied. In this regard, cells were incubated with various concentrations of umbelliprenin in-vitro for different times and assayed for apoptosis with annexin V–FITC/PI double staining flowcytometry method. Results showed that umbelliprenin induced apoptosis in leukemic cells in a dose- and time-dependent manner and that CLL cells were more susceptible to umbelliprenin induced cell death than normal peripheral blood mononuclear cell (PBMCs). Moreover, we study the induction of apoptosis in Jurkat cells by umbelliprenin in the presence of interleukin 4 (IL-4) as an agent that causes resistance to apoptosis in CLL cells, was also student. We showed that IL-4 can not reduce apoptotic effect of umbelliprenin. The preferential toxicity of umbelliprenin for CLL cells, supports the hypothesis that oral administration of umbelliprenin in the form of foods or folk medicines containing this coumarin, might enhance protection against the development of CLL in man with little side effects. In conclusion, umbelliprenin may be an effective therapeutic agent in the treatment of CLL, and thus clinical studies with umbelliprenin may be appropriate. PMID:24250490

  5. Methylated arsenic metabolites bind to PML protein but do not induce cellular differentiation and PML-RARα protein degradation.

    PubMed

    Wang, Qian Qian; Zhou, Xin Yi; Zhang, Yan Fang; Bu, Na; Zhou, Jin; Cao, Feng Lin; Naranmandura, Hua

    2015-09-22

    Arsenic trioxide (As2O3) is one of the most effective therapeutic agents used for patients with acute promyelocytic leukemia (APL). The probable explanation for As2O3-induced cell differentiation is the direct targeting of PML-RARα oncoprotein by As2O3, which results in initiation of PML-RARα degradation. However, after injection, As2O3 is rapidly methylated in body to different intermediate metabolites such as trivalent monomethylarsonous acid (MMA(III)) and dimethylarsinous acid (DMA(III)), therefore, it remains unknown that which arsenic specie is actually responsible for the therapeutic effects against APL. Here we have shown the role of As2O3 (as iAs(III)) and its intermediate metabolites (i.e., MMA(III)/DMA(III)) in NB4 cells. Inorganic iAs(III) predominantly showed induction of cell differentiation, while MMA(III) and DMA(III) specifically showed to induce mitochondria and endoplasmic reticulum-mediated apoptosis, respectively. On the other hand, in contrast to iAs(III), MMA(III) showed stronger binding affinity for ring domain of PML recombinant protein, however, could not induce PML protein SUMOylation and ubiquitin/proteasome degradation. In summary, our results suggest that the binding of arsenicals to the ring domain of PML proteins is not associated with the degradation of PML-RARα fusion protein. Moreover, methylated arsenicals can efficiently lead to cellular apoptosis, however, they are incapable of inducing NB4 cell differentiation. PMID:26213848

  6. Methylated arsenic metabolites bind to PML protein but do not induce cellular differentiation and PML-RARα protein degradation

    PubMed Central

    Zhang, Yan Fang; Bu, Na; Zhou, Jin; Cao, Feng Lin; Naranmandura, Hua

    2015-01-01

    Arsenic trioxide (As2O3) is one of the most effective therapeutic agents used for patients with acute promyelocytic leukemia (APL). The probable explanation for As2O3-induced cell differentiation is the direct targeting of PML-RARα oncoprotein by As2O3, which results in initiation of PML-RARa degradation. However, after injection, As2O3 is rapidly methylated in body to different intermediate metabolites such as trivalent monomethylarsonous acid (MMAIII) and dimethylarsinous acid (DMAIII), therefore, it remains unknown that which arsenic specie is actually responsible for the therapeutic effects against APL. Here we have shown the role of As2O3 (as iAsIII) and its intermediate metabolites (i.e., MMAIII/DMAIII) in NB4 cells. Inorganic iAsIII predominantly showed induction of cell differentiation, while MMAIII and DMAIII specifically showed to induce mitochondria and endoplasmic reticulum-mediated apoptosis, respectively. On the other hand, in contrast to iAsIII, MMAIII showed stronger binding affinity for ring domain of PML recombinant protein, however, could not induce PML protein SUMOylation and ubiquitin/proteasome degradation. In summary, our results suggest that the binding of arsenicals to the ring domain of PML proteins is not associated with the degradation of PML-RARa fusion protein. Moreover, methylated arsenicals can efficiently lead to cellular apoptosis, however, they are incapable of inducing NB4 cell differentiation. PMID:26213848

  7. IDENTIFICATION OF INTERSPECIES CONCORDANCE OF MECHANISMS OF ARSENIC INDUCED BLADDER CANCER BY GENE EXPRESSION.

    EPA Science Inventory

    Arsenic is a human carcinogen that induces urinary bladder cancer. Several mechanisms have been proposed for arsenic-induced cancer. Although inorganic arsenic (iAs) does not induce tumors in adult rodents, dimethylarsinic acid (DMA), a major metabolite of iAs, is a rat bladder c...

  8. Taurine prevents arsenic-induced cardiac oxidative stress and apoptotic damage: Role of NF-{kappa}B, p38 and JNK MAPK pathway

    SciTech Connect

    Ghosh, Jyotirmoy; Das, Joydeep; Manna, Prasenjit

    2009-10-01

    Cardiac dysfunction is a major cause of morbidity and mortality worldwide due to its complex pathogenesis. However, little is known about the mechanism of arsenic-induced cardiac abnormalities and the use of antioxidants as the possible protective agents in this pathophysiology. Conditionally essential amino acid, taurine, accounts for 25% to 50% of the amino acid pool in myocardium and possesses antioxidant properties. The present study has, therefore, been carried out to investigate the underlying mechanism of the beneficial role of taurine in arsenic-induced cardiac oxidative damage and cell death. Arsenic reduced cardiomyocyte viability, increased reactive oxygen species (ROS) production and intracellular calcium overload, and induced apoptotic cell death by mitochondrial dependent caspase-3 activation and poly-ADP ribose polymerase (PARP) cleavage. These changes due to arsenic exposure were found to be associated with increased IKK and NF-{kappa}B (p65) phosphorylation. Pre-exposure of myocytes to an IKK inhibitor (PS-1145) prevented As-induced caspase-3 and PARP cleavage. Arsenic also markedly increased the activity of p38 and JNK MAPKs, but not ERK to that extent. Pre-treatment with SP600125 (JNK inhibitor) and SB203580 (p38 MAPK inhibitor) attenuated NF-{kappa}B and IKK phosphorylation indicating that p38 and JNK MAPKs are mainly involved in arsenic-induced NF-{kappa}B activation. Taurine treatment suppressed these apoptotic actions, suggesting that its protective role in arsenic-induced cardiomyocyte apoptosis is mediated by attenuation of p38 and JNK MAPK signaling pathways. Similarly, arsenic intoxication altered a number of biomarkers related to cardiac oxidative stress and other apoptotic indices in vivo and taurine supplementation could reduce it. Results suggest that taurine prevented arsenic-induced myocardial pathophysiology, attenuated NF-{kappa}B activation via IKK, p38 and JNK MAPK signaling pathways and could possibly provide a protection

  9. ANTIOXIDANTS AMELIORATION OF ARSENICAL-INDUCED EFFECTS IN VIVO

    EPA Science Inventory

    Antioxidant amelioration of arsenical-induced effects in vivo. ES Hunter and EH Rogers. Reproductive Toxicology Division, NHEERL, US EPA, RTP, NC.

    Antioxidants have been reported to ameliorate the effects of many developmental toxicants. We tested the hypothesis that oxi...

  10. Lithium protects ethanol-induced neuronal apoptosis

    SciTech Connect

    Zhong Jin . E-mail: jizhong@iupui.edu; Yang Xianlin; Yao Weiguo; Lee Weihua

    2006-12-01

    Lithium is widely used for the treatment of bipolar disorder. Recent studies have demonstrated its neuroprotective effect. Ethanol is a potent neurotoxin that is particularly harmful to the developing nervous system. In this study, we evaluated lithium's neuroprotection against ethanol-induced apoptosis. Transient exposure of infant mice to ethanol caused apoptotic cell death in brain, which was prevented significantly by administering a low dose of lithium 15 min later. In cultured cerebellar granule neurons, ethanol-induced apoptosis and activation of caspase-3/9, both of which were prevented by lithium. However, lithium's protection is not mediated by its commonly known inhibition of glycogen synthase3{beta}, because neither ethanol nor lithium has significant effects on the phosphorylation of Akt (ser473) or GSK3{beta} (ser9). In addition, the selective GSK-3{beta} inhibitor SB-415286 was unable to prevent ethanol-induced apoptosis. These data suggest lithium may be used as a potential preventive measure for ethanol-induced neurological deficits.

  11. Arsenic exposure induces the Warburg effect in cultured human cells

    SciTech Connect

    Zhao, Fei; Severson, Paul; Pacheco, Samantha; Futscher, Bernard W.; Klimecki, Walter T.

    2013-08-15

    Understanding how arsenic exacts its diverse, global disease burden is hampered by a limited understanding of the particular biological pathways that are disrupted by arsenic and underlie pathogenesis. A reductionist view would predict that a small number of basic pathways are generally perturbed by arsenic, and manifest as diverse diseases. Following an initial observation that arsenite-exposed cells in culture acidify their media more rapidly than control cells, the report here shows that low level exposure to arsenite (75 ppb) is sufficient to induce aerobic glycolysis (the Warburg effect) as a generalized phenomenon in cultured human primary cells and cell lines. Expanded studies in one such cell line, the non-malignant pulmonary epithelial line, BEAS-2B, established that the arsenite-induced Warburg effect was associated with increased accumulation of intracellular and extracellular lactate, an increased rate of extracellular acidification, and inhibition by the non-metabolized glucose analog, 2-deoxy-D-glucose. Associated with the induction of aerobic glycolysis was a pathway-wide induction of glycolysis gene expression, as well as protein accumulation of an established glycolysis master-regulator, hypoxia-inducible factor 1A. Arsenite-induced alteration of energy production in human cells represents the type of fundamental perturbation that could extend to many tissue targets and diseases. - Highlights: • Chronic arsenite exposure induces aerobic glycolysis, dubbed the “Warburg effect”. • Arsenite-induced Warburg effect is a general phenomenon in cultured human cells. • HIF-1A may mediate arsenite induced Warburg effect.

  12. Role and mechanism of miR-222 in arsenic-transformed cells for inducing tumor growth

    PubMed Central

    Wang, Min; Li, Dongmei; Liu, Xue; Wang, Lin; Jiang, Chengfei; Shi, Zhumei; Qin, Lianju; Liu, Jiayin; Yang, Hushan; Liu, Ling-Zhi; He, Jun; Zhen, Linlin; Jiang, Bing-Hua

    2016-01-01

    High levels of arsenic in drinking water, soil, and air are associated with the higher incidences of several kinds of cancers worldwide, but the mechanism is yet to be fully discovered. Recently, a number of evidences show that dysregulation of microRNAs (miRNAs) induces carcinogenesis. In this study, we found miR-222 was upregulated in arsenic-transformed human lung epithelial BEAS-2B cells (As-T cells). Anti-miR-222 inhibitor treatment decreased cell proliferation, migration, tube formation, and induced apoptosis. In addition, anti-miR-222 inhibitor expression decreased tumor growth in vivo. We also found that inhibition of miR-222 induced the expression of its direct targets ARID1A and phosphatase and tensin homolog deleted on chromosome 10 (PTEN), and activated apoptosis of As-T cells in part through ARID1A downregulation. These results indicate that miR-222 plays an important role in arsenic-induced tumor growth. PMID:26909602

  13. Farnesol-induced apoptosis in Candida albicans.

    PubMed

    Shirtliff, Mark E; Krom, Bastiaan P; Meijering, Roelien A M; Peters, Brian M; Zhu, Jingsong; Scheper, Mark A; Harris, Megan L; Jabra-Rizk, Mary Ann

    2009-06-01

    Farnesol, a precursor in the isoprenoid/sterol pathway, was recently identified as a quorum-sensing molecule produced by the fungal pathogen Candida albicans. Farnesol is involved in the inhibition of germination and biofilm formation by C. albicans and can be cytotoxic at certain concentrations. In addition, we have shown that farnesol can trigger apoptosis in mammalian cells via the classical apoptotic pathways. In order to elucidate the mechanism behind farnesol cytotoxicity in C. albicans, the response to farnesol was investigated, using proteomic analysis. Global protein expression profiles demonstrated significant changes in protein expression resulting from farnesol exposure. Among the downregulated proteins were those involved in metabolism, glycolysis, protein synthesis, and mitochondrial electron transport and the respiratory chain, whereas proteins involved in folding, protection against environmental and oxidative stress, actin cytoskeleton reorganization, and apoptosis were upregulated. Cellular changes that accompany apoptosis (regulated cell death) were further analyzed using fluorescent microscopy and gene expression analysis. The results indicated reactive oxygen species accumulation, mitochondrial degradation, and positive terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) in the farnesol-exposed cells concurrent with increased expression of antioxidant-encoding and drug response genes. More importantly, the results demonstrated farnesol-induced upregulation of the caspase gene MCA1 and the intracellular presence of activated caspases. In conclusion, this study demonstrated that farnesol promotes apoptosis in C. albicans through caspase activation, implying an important physiological role for farnesol in the fungal cell life cycle with important implications for adaptation and survival. PMID:19364863

  14. EFFECTS OF DIETARY FOLATE ON ARSENIC-INDUCED GENE EXPRESSION IN MICE

    EPA Science Inventory

    Effects of Dietary Folate on Arsenic-induced Gene Expression in Mice

    Arsenic, a drinking water contaminant, is a known carcinogen. Human exposure to inorganic arsenic has been linked to tumors of skin, bladder, lung, and to a lesser extent, kidney and liver. Dietary fola...

  15. Cytogenetic insights into DNA damage and repair of lesions induced by a monomethylated trivalent arsenical

    EPA Science Inventory

    Arsenic is a human carcinogen, and only recently have animal models been developed that are useful in investigating its carcinogenic mode ofaction (MOA). However, how arsenic induces cancer is still an open question. In a previous paper, we proposed a model detailing how arsenic ...

  16. Arsenic

    MedlinePlus

    ... mainly found in its less toxic organic form. Industrial processes Arsenic is used industrially as an alloying ... are also required to reduce occupational exposure from industrial processes. Education and community engagement are key factors ...

  17. Enhancement of Arsenic Trioxide-Mediated Changes in Human Induced Pluripotent Stem Cells (IPS)

    PubMed Central

    Graham, Barbara; Stevens, Jacqueline; Wells, Phatia; Sims, Jennifer; Rogers, Christian; Leggett, Sophia S.; Ekunwe, Stephen; Ndebele, Kenneth

    2014-01-01

    Induced pluripotent stem cells (IPS) are an artificially derived type of pluripotent stem cell, showing many of the same characteristics as natural pluripotent stem cells. IPS are a hopeful therapeutic model; however there is a critical need to determine their response to environmental toxins. Effects of arsenic on cells have been studied extensively; however, its effect on IPS is yet to be elucidated. Arsenic trioxide (ATO) has been shown to inhibit cell proliferation, induce apoptosis and genotoxicity in many cells. Based on ATOs action in other cells, we hypothesize that it will induce alterations in morphology, inhibit cell viability and induce a genotoxic effect on IPS. Cells were treated for 24 hours with ATO (0–9 µg/mL). Cell morphology, viability and DNA damage were documented. Results indicated sufficient changes in morphology of cell colonies mainly in cell ability to maintain grouping and ability to remain adherent. Cell viability decreased in a dose dependent manner. There were significant increases in tail length and moment as well as destruction of intact DNA as concentration increased. Exposure to ATO resulted in a reproducible dose dependent sequence of events marked by changes in morphology, decrease of cell viability, and induction of genotoxicity in IPS. PMID:25054231

  18. In Vivo and In Vitro Arsenic Exposition Induces Oxidative Stress in Anterior Pituitary Gland.

    PubMed

    Ronchetti, Sonia A; Bianchi, María S; Duvilanski, Beatriz H; Cabilla, Jimena P

    2016-07-01

    Inorganic arsenic (iAs) is at the top of toxic metalloids. Inorganic arsenic-contaminated water consumption is one of the greatest environmental health threats worldwide. Human iAs exposure has been associated with cancers of several organs, neurological disorders, and reproductive problems. Nevertheless, there are no reports describing how iAs affects the anterior pituitary gland. The aim of this study was to investigate the mechanisms involved in iAs-mediated anterior pituitary toxicity both in vivo and in vitro. We showed that iAs administration (from 5 to 100 ppm) to male rats through drinking water increased messenger RNA expression of several oxidative stress-responsive genes in the anterior pituitary gland. Serum prolactin levels diminished, whereas luteinizing hormone (LH) levels were only affected at the higher dose tested. In anterior pituitary cells in culture, 25 µmol/L iAs significantly decreased prolactin release in a time-dependent fashion, whereas LH levels remained unaltered. Cell viability was significantly reduced mainly by apoptosis evidenced by morphological and phosphatidylserine externalization studies. This process is characterized by early depolarization of mitochondrial membrane potential and increased levels of reactive oxygen species. Expression of some key oxidative stress-responsive genes, such as heme oxygenase-1 and metallothionein-1, was also stimulated by iAs exposure. The antioxidant N-acetyl cysteine prevented iAs-induced effects on the expression of oxidative stress markers, prolactin release, and apoptosis. In summary, the present work demonstrates for the first time that iAs reduces prolactin release both in vivo and in vitro and induces apoptosis in anterior pituitary cells, possibly resulting from imbalanced cellular redox status. PMID:27151894

  19. Artesunate induces AIF-dependent apoptosis in A549 cells

    NASA Astrophysics Data System (ADS)

    Zhou, Chen-juan; Chen, Tong-Sheng

    2012-03-01

    Artesunate (ART), a semi-synthetic derivative of the sesquiterpene artemisinin extracted from the Chinese herb Artemisia annua, exerts a broad spectrum of clinical activity against human cancers. It has been shown that ART induces cancer cells death through apoptosis pathway. This study investigated whether ART treatment induced reactive oxygen species (ROS)-dependent cell death in the apoptosis fashion in human lung adenocarconoma A549 cell line and the proapoptotic protein apoptosis inducing factor (AIF) is involved in ART-induced apoptosis. Cells treated with ART exhibited typical apoptotic morphology as chromatin condensation, margination and shrunken nucleus. ART treatment also induced a loss of mitochondrial membrane potential and AIF release from mitochondria. Silencing AIF can remarkable attenuated ART-induced apoptosis. Collectively, ART induces apoptosis by caspase-independent intrinsic pathway in A549 cells.

  20. Mitotic arrest-associated apoptosis induced by sodium arsenite in A375 melanoma cells is BUBR1-dependent

    SciTech Connect

    McNeely, Samuel C.; Taylor, B. Frazier; States, J. Christopher

    2008-08-15

    A375 human malignant melanoma cells undergo mitotic arrest-associated apoptosis when treated with pharmacological concentrations of sodium arsenite, a chemotherapeutic for acute promyelocytic leukemia. Our previous studies indicated that decreased arsenite sensitivity correlated with reduced mitotic spindle checkpoint function and reduced expression of the checkpoint protein BUBR1. In the current study, arsenite induced securin and cyclin B stabilization, BUBR1 phosphorylation, and spindle checkpoint activation. Arsenite also increased activating cyclin dependent kinase 1 (CDK1) Thr{sup 161} phosphorylation but decreased inhibitory Tyr15 phosphorylation. Mitotic arrest resulted in apoptosis as indicated by colocalization of mitotic phospho-Histone H3 with active caspase 3. Apoptosis was associated with BCL-2 Ser70 phosphorylation. Inhibition of CDK1 with roscovitine in arsenite-treated mitotic cells inhibited spindle checkpoint maintenance as inferred from reduced BUBR1 phosphorylation, reduced cyclin B expression, and diminution of mitotic index. Roscovitine also reduced BCL-2 Ser70 phosphorylation and protected against apoptosis, suggesting mitotic arrest caused by hyperactivation of CDK1 directly or indirectly leads to BCL-2 phosphorylation and apoptosis. In addition, suppression of BUBR1 with siRNA prevented arsenite-induced mitotic arrest and apoptosis. These findings provide insight into the mechanism of arsenic's chemotherapeutic action and indicate a functional spindle checkpoint may be required for arsenic-sensitivity.

  1. Arsenic responsive microRNAs in vivo and their potential involvement in arsenic-induced oxidative stress

    SciTech Connect

    Ren, Xuefeng; Gaile, Daniel P.; Gong, Zhihong; Qiu, Wenting; Ge, Yichen; Zhang, Chuanwu; Huang, Chenping; Yan, Hongtao; Olson, James R.; Kavanagh, Terrance J.; Wu, Hongmei

    2015-03-15

    Arsenic exposure is postulated to modify microRNA (miRNA) expression, leading to changes of gene expression and toxicities, but studies relating the responses of miRNAs to arsenic exposure are lacking, especially with respect to in vivo studies. We utilized high-throughput sequencing technology and generated miRNA expression profiles of liver tissues from Sprague Dawley (SD) rats exposed to various concentrations of sodium arsenite (0, 0.1, 1, 10 and 100 mg/L) for 60 days. Unsupervised hierarchical clustering analysis of the miRNA expression profiles clustered the SD rats into different groups based on the arsenic exposure status, indicating a highly significant association between arsenic exposure and cluster membership (p-value of 0.0012). Multiple miRNA expressions were altered by arsenic in an exposure concentration-dependent manner. Among the identified arsenic-responsive miRNAs, several are predicted to target Nfe2l2-regulated antioxidant genes, including glutamate–cysteine ligase (GCL) catalytic subunit (GCLC) and modifier subunit (GCLM) which are involved in glutathione (GSH) synthesis. Exposure to low concentrations of arsenic increased mRNA expression for Gclc and Gclm, while high concentrations significantly reduced their expression, which were correlated to changes in hepatic GCL activity and GSH level. Moreover, our data suggested that other mechanisms, e.g., miRNAs, rather than Nfe2l2-signaling pathway, could be involved in the regulation of mRNA expression of Gclc and Gclm post-arsenic exposure in vivo. Together, our findings show that arsenic exposure disrupts the genome-wide expression of miRNAs in vivo, which could lead to the biological consequence, such as an altered balance of antioxidant defense and oxidative stress. - Highlights: • Chronic arsenic exposure induces changes of hepatic miRNA expression profiles. • Hepatic GCL activity and GSH level in rats are altered following arsenic exposure. • Arsenic induced GCL expression change is

  2. Arsenic-induced plant growth of arsenic-hyperaccumulator Pteris vittata: Impact of arsenic and phosphate rock.

    PubMed

    Han, Yong-He; Yang, Guang-Mei; Fu, Jing-Wei; Guan, Dong-Xing; Chen, Yanshan; Ma, Lena Q

    2016-04-01

    Phosphate rock (PR) has been shown to promote plant growth and arsenic (As) uptake by As-hyperaccumulator Pteris vittata (PV). However, little is known about its behaviors in agricultural soils. In this study, impact of 50 mg kg(-1) As and/or 1.5% PR amendment on plant As accumulation and growth was investigated by growing PV for 90 d in three agricultural soils. While As amendment significantly increased plant As uptake and substantially promoted PV growth, the opposite was observed with PR amendment. Arsenic amendment increased plant frond As from 16.9-265 to 961-6017 mg kg(-1),whereas PR amendment lowered frond As to 10.2-216 mg kg(-1). The As-induced plant growth stimulation was 69-71%. While PR amendment increased plant Ca and P uptake, As amendment showed opposite results. The PV biomass was highly correlated with plant As at r = 0.82, but with weak correlations with plant Ca or P at r < 0.30. This study confirmed that 1) As significantly promoted PV growth, probably independent of Ca or P uptake, 2) PR amendment didn't enhance plant growth or As uptake by PV in agricultural soils with adequate available P, and 3) PV effluxed arsenite (AsIII) growing in agricultural soils. PMID:26874625

  3. HIV-1 protease-induced apoptosis

    PubMed Central

    2014-01-01

    Background Apoptosis is one of the presumptive causes of CD4+ T cell depletion during HIV infection and progression to AIDS. However, the precise role of HIV-1 in this process remains unexplained. HIV-1 protease (PR) has been suggested as a possible factor, but a direct link between HIV-1 PR enzymatic activity and apoptosis has not been established. Results Here, we show that expression of active HIV-1 PR induces death in HeLa and HEK-293 cells via the mitochondrial apoptotic pathway. This conclusion is based on in vivo observations of the direct localization of HIV-1 PR in mitochondria, a key player in triggering apoptosis. Moreover, we observed an HIV-1 PR concentration-dependent decrease in mitochondrial membrane potential and the role of HIV-1 PR in activation of caspase 9, PARP cleavage and DNA fragmentation. In addition, in vitro data demonstrated that HIV-1 PR mediates cleavage of mitochondrial proteins Tom22, VDAC and ANT, leading to release of AIF and Hsp60 proteins. By using yeast two-hybrid screening, we also identified a new HIV-1 PR interaction partner, breast carcinoma-associated protein 3 (BCA3). We found that BCA3 accelerates p53 transcriptional activity on the bax promoter, thus elevating the cellular level of pro-apoptotic Bax protein. Conclusion In summary, our results describe the involvement of HIV-1 PR in apoptosis, which is caused either by a direct effect of HIV-1 PR on mitochondrial membrane integrity or by its interaction with cellular protein BCA3. PMID:24886575

  4. Rabies virus matrix protein induces apoptosis by targeting mitochondria.

    PubMed

    Zan, Jie; Liu, Juan; Zhou, Jian-Wei; Wang, Hai-Long; Mo, Kai-Kun; Yan, Yan; Xu, Yun-Bin; Liao, Min; Su, Shuo; Hu, Rong-Liang; Zhou, Ji-Yong

    2016-09-10

    Apoptosis, as an innate antiviral defense, not only functions to limit viral replication by eliminating infected cells, but also contribute to viral dissemination, particularly at the late stages of infection. A highly neurotropic CVS strain of rabies virus induces apoptosis both in vitro and in vivo. However, the detailed mechanism of CVS-mediated neuronal apoptosis is not entirely clear. Here, we show that CVS induces apoptosis through mitochondrial pathway by dissipating mitochondrial membrane potential, release of cytochrome c and AIF. CVS blocks Bax activation at the early stages of infection; while M protein partially targets mitochondria and induces mitochondrial apoptosis at the late stages of infection. The α-helix structure spanning 67-79 amino acids of M protein is essential for mitochondrial targeting and induction of apoptosis. These results suggest that CVS functions on mitochondria to regulate apoptosis at different stages of infection, so as to for viral replication and dissemination. PMID:27426727

  5. Possible mechanisms for arsenic-induced proliferative diseases

    SciTech Connect

    Wetterhahn, K.E.; Dudek, E.J.; Shumilla, J.A.

    1996-12-31

    Possible mechanisms for cardiovascular diseases and cancers which have been observed on chronic exposure to arsenic have been investigated. We tested the hypothesis that nonlethal levels of arsenic are mitogenic, cause oxidative stress, increase nuclear translocation of trans-acting factors, and increase expression of genes involved in proliferation. Cultured porcine vascular (from aorta) endothelial cells were used as a model cell system to study the effects of arsenic on the target cells for cardiovascular diseases. Treatment of postconfluent cell cultures with nonovertly toxic concentrations of arsenite increased DNA synthesis, similar to the mitogenic response observed with hydrogen peroxide. Within 1 hour of adding noncytotoxic concentrations of arsenite, cellular levels of oxidants increased relative to control levels, indicating that arsenite promotes cellular oxidations. Arsenite treatment increased nuclear translocation of NF-{kappa}B, an oxidative stress-responsive transcription factor, in a manner similar to that observed with hydrogen peroxide. Pretreatment of intact cells with the antioxidants N-acetylcysteine and dimethylfumarate prevented the arsenite-induced increases in cellular oxidant formation and NF-KB translocation. Arsenite had little or no effect on binding of NF-KB to its DNA recognition sequence in vitro, indicating that it is unlikely that arsenite directly affects NF-KB. The steady-state mRNA levels of intracellular adhesion molecule and urokinase-like plasminogen activator, genes associated with the active endothelial phenotype in arteriosclerosis and cancer metastasis, were increased by nontoxic concentrations of arsenite. These data suggest that arsenite promotes proliferative diseases like heart disease and cancer by activating oxidant-sensitive endothelial cell signaling and gene expression. It is possible that antioxidant therapy would be useful in preventing arsenic-induced cardiovascular disease and cancer.

  6. Arsenic-induced bladder cancer in an animal model

    SciTech Connect

    Cohen, Samuel M. Ohnishi, Takamasa Arnold, Lora L. Le, X. Chris

    2007-08-01

    Dimethylarsinic acid (DMA{sup V}) is carcinogenic to the rat urinary bladder, but not in mice. The carcinogenic mode of action involves cytotoxicity followed by regenerative cell proliferation. Dietary DMA{sup V} does not produce urinary solids or significant alterations in urinary composition. The cytotoxicity is due to formation of a reactive metabolite, likely dimethylarsinous acid (DMA{sup III}), concentrated and excreted in the urine. Urinary concentrations of DMA{sup III} are dose-dependent, and the urinary concentrations are at cytotoxic levels based on in vitro studies. The no observed effect level (NOEL) in these rat dietary studies for detectable levels of DMA{sup III}, cytotoxicity, and proliferation is 2 ppm, with marginal changes at 10 ppm. The tumorigenic dose is 100 ppm. Recent investigations have demonstrated that arsenicals administered to the rat result in binding to a specific cysteine in the hemoglobin alpha chain as DMA{sup III}, regardless of the arsenical being administered. Monomethylarsonic acid (MMA{sup V}) is not carcinogenic in rats or mice. In short term experiments ({<=} 10 weeks), sodium arsenate in the drinking water induces significant cytotoxicity and regenerative proliferation. There is little evidence that the cytotoxicity produced following administration of arsenicals is caused by oxidative damage, as antioxidants show little inhibitory activity of the cytotoxicity of the various arsenicals either in vitro or in vivo. In summary, the mode of action for DMA{sup V}-induced bladder carcinogenesis in the rat involves generation of a reactive metabolite (DMA{sup III}) leading to cytotoxicity and regenerative proliferation, is a non-linear process, and likely involves a threshold. Extrapolation to human risk needs to take this into account along with the significant differences in toxicokinetics and toxicodynamics that occur between different species.

  7. Research Advances on Pathways of Nickel-Induced Apoptosis

    PubMed Central

    Guo, Hongrui; Chen, Lian; Cui, Hengmin; Peng, Xi; Fang, Jing; Zuo, Zhicai; Deng, Junliang; Wang, Xun; Wu, Bangyuan

    2015-01-01

    High concentrations of nickel (Ni) are harmful to humans and animals. Ni targets a number of organs and produces multiple toxic effects. Apoptosis is important in Ni-induced toxicity of the kidneys, liver, nerves, and immune system. Apoptotic pathways mediated by reactive oxygen species (ROS), mitochondria, endoplasmic reticulum (ER), Fas, and c-Myc participate in Ni-induced cell apoptosis. However, the exact mechanism of apoptosis caused by Ni is still unclear. Understanding the mechanism of Ni-induced apoptosis may help in designing measures to prevent Ni toxicity. PMID:26703593

  8. Oleuropein ameliorates arsenic induced oxidative stress in mice.

    PubMed

    Ogun, Metin; Ozcan, Ayla; Karaman, Musa; Merhan, Oguz; Ozen, Hasan; Kukurt, Abdulsamed; Karapehlivan, Mahmut

    2016-07-01

    The objective of this study is to investigate the potential preventive effect of oleuropein in an experimental arsenic toxicity in mice. For this purpose, mice were exposed to 5mg/kg/day sodium arsenite (NaAsO2) in drinking water and treated with 30mg/kg/day oleuropein for 15 days. At the end of the experiment, animals were sacrificed and selected organs were processed for biochemical and histopahtological investigations. Blood, liver, kidney and brain malondialdehyde (MDA) and nitric oxide (NO) levels were determined by colorimetric methods. Protein carbonyl content is measured by a commercial kit. Liver morphology and immunoreactivity for inducible NOS (iNOS) and endothelial NOS (eNOS) was evaluated microscopically. Level of NO was determined to decrease in blood and tissues whereas MDA increased in arsenic given mice. Tissue protein carbonyl content also increased in this group. Immunoreactivity for iNOS and eNOS was noted to increase with arsenic treatment. Oleuropein treatment had significant effects in normalizing the MDA and NO levels as well as protein carbonyl content. Immunohistochemical staining also showed reduction of the expression of iNOS and eNOS in liver. The results indicate that oleuropein ameliorates oxidative tissue damage by scavenging free radicals. PMID:27259345

  9. Quercetin-induced apoptosis prevents EBV infection

    PubMed Central

    Lee, Minjung; Son, Myoungki; Ryu, Eunhyun; Shin, Yu Su; Kim, Jong Gwang; Kang, Byung Woog; Sung, Gi-Ho; Cho, Hyosun; Kang, Hyojeung

    2015-01-01

    Epstein-Barr virus (EBV) is a human gamma-1 herpesvirus that establishes a lifelong latency in over 90% of the world's population. During latency, virus exists predominantly as a chromatin-associated, multicopy episome in the nuclei of a variety of tumor cells derived from B cells, T cells, natural killer (NK) cells, and epithelial cells. Licorice is the root of Glycyrrhiza uralensis or G. glabra that has traditionally cultivated in eastern part of Asia. Licorice was reported to have anti-viral, anti-inflammatory, anti-atopic, hepatoprotective, anti-neurodegenerative, anti-tumor, anti-diabetic effects and so forth. Quercetin and isoliquiritigenin are produced from licorice and highly similar in molecular structure. They have diverse bioactive effects such as antiviral activity, anti-asthmatic activity, anti-cancer activity, anti-inflammation activity, monoamine-oxidase inhibitor, and etc. To determine anti-EBV and anti-EBVaGC (Epstein-Barr virus associated gastric carcinoma) effects of licorice, we investigated antitumor and antiviral effects of quercetin and isoliquiritigenin against EBVaGC. Although both quercetin and isoliquiritigenin are cytotoxic to SNU719 cells, quercetin induced more apoptosis in SNU719 cells than isoliquiritigenin, more completely eliminated DNMT1 and DNMT3A expressions than isoliquiritigenin, and more strongly affects the cell cycle progression of SNU719 than isoliquiritigenin. Both quercetin and isoliquiritigenin induce signal transductions to stimulate apoptosis, and induce EBV gene transcription. Quercetin enhances frequency of F promoter use, whereas isoliquiritigenin enhances frequency of Q promoter use. Quercetin reduces EBV latency, whereas isoliquiritigenin increases the latency. Quercetin increases more the EBV progeny production, and inhibits more EBV infection than isoliquiritigenin. These results indicate that quercetin could be a promising candidate for antiviral and antitumor agents against EBV and human gastric carcinoma

  10. Sodium arsenite induces apoptosis and Epstein-Barr virus reactivation in lymphoblastoid cells.

    PubMed

    Zebboudj, Abderezak; Maroui, Mohamed Ali; Dutrieux, Jacques; Touil-Boukoffa, Chafia; Bourouba, Mehdi; Chelbi-Alix, Mounira K; Nisole, Sébastien

    2014-12-01

    Epstein-Barr virus (EBV) is associated with several malignancies, including carcinomas, such as nasopharyngeal carcinoma, and lymphomas, such as Burkitt's lymphoma and Hodgkin's lymphoma. The Latent Membrane Protein 1 (LMP1) is the major oncogene protein of EBV as its expression is responsible for the induction of cell transformation, immortalization and proliferation. Arsenic trioxide was shown to induce a cytotoxic effect on nasopharyngeal cancer cells associated with LMP1 down-regulation. However, the effect of arsenic on EBV-associated lymphoproliferative malignancies has been less studied. We investigated the effect of two different arsenical compounds, arsenic trioxide (As2O3) and sodium arsenite (NaAsO2) on the induction of cell death in P3HR1 cells, an Epstein-Barr virus-positive Burkitt lymphoma derived cell line. Both compounds inhibited cell growth and induced cell death. By flow-cytometry and Western blot analysis, we provide evidence that NaAsO2 induced caspase-dependent apoptosis whereas As2O3 triggered autophagic cell death. Furthermore, we show that NaAsO2 treatment led to a dramatic decrease of the expression level of LMP1 and the cellular protein PML. Importantly, this down-regulation was associated with a reactivation of EBV lytic cycle through the induction of immediate-early proteins Zta and Rta. These results are in agreement with a model in which LMP1 maintains EBV in a latent state by stabilizing PML expression. Altogether, our results suggest that NaAsO2 would represent a better therapeutic candidate than As2O3 in EBV-induced B lymphoma for its capacity to promote viral reactivation. PMID:25241256

  11. Arsenic Exposure Induces Unscheduled Mitotic S Phase Entry Coupled with Cell Death in Mouse Cortical Astrocytes

    PubMed Central

    Htike, Nang T. T.; Maekawa, Fumihiko; Soutome, Haruka; Sano, Kazuhiro; Maejima, Sho; Aung, Kyaw H.; Tokuda, Masaaki; Tsukahara, Shinji

    2016-01-01

    There is serious concern about arsenic in the natural environment, which exhibits neurotoxicity and increases the risk of neurodevelopmental disorders. Adverse effects of arsenic have been demonstrated in neurons, but it is not fully understood how arsenic affects other cell types in the brain. In the current study, we examined whether sodium arsenite (NaAsO2) affects the cell cycle, viability, and apoptosis of in vitro-cultured astrocytes isolated from the cerebral cortex of mice. Cultured astrocytes from transgenic mice expressing fluorescent ubiquitination-based cell cycle indicator (Fucci) were subjected to live imaging analysis to assess the effects of NaAsO2 (0, 1, 2, and 4 μM) on the cell cycle and number of cells. Fucci was designed to express monomeric Kusabira Orange2 (mKO2) fused with the ubiquitylation domain of hCdt1, a marker of G1 phase, and monomeric Azami Green (mAG) fused with the ubiquitylation domain of hGem, a marker of S, G2, and M phases. NaAsO2 concentration-dependently decreased the peak levels of the mAG/mKO2 emission ratio when the ratio had reached a peak in astrocytes without NaAsO2 exposure, which was due to attenuating the increase in the mAG-expressing cell number. In contrast, the mAG/mKO2 emission ratio and number of mAG-expressing cells were concentration-dependently increased by NaAsO2 before their peak levels, indicating unscheduled S phase entry. We further examined the fate of cells forced to enter S phase by NaAsO2. We found that most of these cells died up to the end of live imaging. In addition, quantification of the copy number of the glial fibrillary acidic protein gene expressed specifically in astrocytes revealed a concentration-dependent decrease caused by NaAsO2. However, NaAsO2 did not increase the amount of nucleosomes generated from DNA fragmentation and failed to alter the gene expression of molecules relevant to unscheduled S phase entry-coupled apoptosis (p21, p53, E2F1, E2F4, and Gm36566). These findings

  12. Participation of cyclin A in Myc-induced apoptosis.

    PubMed Central

    Hoang, A T; Cohen, K J; Barrett, J F; Bergstrom, D A; Dang, C V

    1994-01-01

    The involvement of c-Myc in cellular proliferation or apoptosis has been linked to differential cyclin gene expression. We observed that in both proliferating cells and cells undergoing apoptosis, cyclin A (but not B, C, D1, and E) mRNA level was elevated in unsynchronized Myc-overexpressing cells when compared with parental Rat1a fibroblasts. We further demonstrated that Zn(2+)-inducible cyclin A expression was sufficient to cause apoptosis. When Myc-induced apoptosis was blocked by coexpression of Bcl-2, the levels of cyclin C, D1, and E mRNAs were also elevated. Thus, while apoptosis induced by c-Myc is associated with an elevated cyclin A mRNA level, protection from apoptosis by coexpressed Bcl-2 is associated with a complementary increase in cyclin C, D1, and E mRNAs. Images PMID:8041712

  13. Platelets induce apoptosis via membrane-bound FasL

    PubMed Central

    Schleicher, Rebecca I.; Reichenbach, Frank; Kraft, Peter; Kumar, Anil; Lescan, Mario; Todt, Franziska; Göbel, Kerstin; Hilgendorf, Ingo; Geisler, Tobias; Bauer, Axel; Olbrich, Marcus; Schaller, Martin; Wesselborg, Sebastian; O’Reilly, Lorraine; Meuth, Sven G.; Schulze-Osthoff, Klaus; Gawaz, Meinrad; Li, Xuri; Kleinschnitz, Christoph; Edlich, Frank

    2015-01-01

    After tissue injury, both wound sealing and apoptosis contribute to restoration of tissue integrity and functionality. Although the role of platelets (PLTs) for wound closure and induction of regenerative processes is well established, the knowledge about their contribution to apoptosis is incomplete. Here, we show that PLTs present the death receptor Fas ligand (FasL) on their surface after activation. Activated PLTs as well as the isolated membrane fraction of activated PLTs but not of resting PLTs induced apoptosis in a dose-dependent manner in primary murine neuronal cells, human neuroblastoma cells, and mouse embryonic fibroblasts. Membrane protein from PLTs lacking membrane-bound FasL (FasL△m/△m) failed to induce apoptosis. Bax/Bak-mediated mitochondrial apoptosis signaling in target cells was not required for PLT-induced cell death, but increased the apoptotic response to PLT-induced Fas signaling. In vivo, PLT depletion significantly reduced apoptosis in a stroke model and an inflammation-independent model of N-methyl-d-aspartic acid-induced retinal apoptosis. Furthermore, experiments using PLT-specific PF4Cre+ FasLfl/fl mice demonstrated a role of PLT-derived FasL for tissue apoptosis. Because apoptosis secondary to injury prevents inflammation, our findings describe a novel mechanism on how PLTs contribute to tissue homeostasis. PMID:26232171

  14. PRMT6 mediates CSE induced inflammation and apoptosis.

    PubMed

    Kang, Naixing; Chen, Ping; Chen, Yan; Zeng, Huihui; He, Xue; Zhu, Yingqun

    2015-01-01

    Cigarette smoke extract (CSE) induces apoptosis and inflammation, but the mechanism is unknown. Arginine methyltransferase (PRMT6) catalyzes the asymmetric di-methylation of histone H3 arginine 2 (H3R2me2a) to control global level transcription. We hypothesized that PRMT6 mediates CSE induced apoptosis and inflammation through H3R2me2a. The apoptosis after CSE treatment in human umbilical vein endothelial cells (HUVECs) was fully measured with real-time reverse transcription PCR, western blotting and Annexin-V staining. Meanwhile, the inflammation in HUVECs after CSE exposure was detected with real-time reverse transcription PCR, western blotting and ELISA. CSE treatment promoted apoptosis and inflammation in HUVECs, coinciding with the decreased protein abundance of PRMT6. Meanwhile, HUVECs transfected with PRMT6 expressing plasmid inhibited the CSE-induced apoptosis and inflammation. Also, the inhibition of PRMT6 promoted the apoptosis and inflammation in HUVECs induced by CSE. Notably, H3R2me2a was associated with the modulation of PRMT6 in CSE induced apoptosis and inflammation in HUVECs. In conclusion, PRMT6 mediates CSE induced apoptosis and inflammation through H3R2me2a in HUVECs. PMID:25481537

  15. Role of PUMA in methamphetamine-induced neuronal apoptosis.

    PubMed

    Chen, Chuanxiang; Qincao, Litao; Xu, Jingtao; Du, Sihao; Huang, Enping; Liu, Chao; Lin, Zhoumeng; Xie, Wei-Bing; Wang, Huijun

    2016-01-01

    Exposure to methamphetamine (METH), a widely used illicit drug, has been shown to cause neuron apoptosis. p53 upregulated modulator of apoptosis (PUMA) is a key mediator in neuronal apoptosis. This study aimed to examine the effects of PUMA in METH-induced neuronal apoptosis. We determined PUMA protein expression in PC12 cells and SH-SY5Y cells after METH exposure using western blot. We also observed the effect of METH on neuronal apoptosis after silencing PUMA expression with siRNA using TUNEL staining and flow cytometry. Additionally, to investigate possible mechanisms of METH-induced PUMA-mediated neuronal apoptosis, we measured the protein expression of apoptotic markers, including cleaved caspase-3, cleaved PARP, Bax, B-cell leukemia/lymphoma-2 (Bcl-2) and cytochrome c (cyto c), after METH treatment with or without PUMA knockdown. Results showed that METH exposure induced cell apoptosis, increased PUMA protein levels, activated caspase-3 and PARP, elevated Bax and reduced Bcl-2 expression, as well as increased the release of cyto c from mitochondria to the cytoplasm in both PC12 and SH-SY5Y cells. All these effects were attenuated or reversed after silencing PUMA. A schematic depicting the role of PUMA in METH-induced mitochondrial apoptotic pathway was proposed. Our results suggest that PUMA plays an important role in METH-triggered apoptosis and it may be a potential target for ameliorating neuronal injury and apoptosis caused by METH. PMID:26524635

  16. Marine Drugs Regulating Apoptosis Induced by Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand (TRAIL)

    PubMed Central

    Elmallah, Mohammed I. Y.; Micheau, Olivier

    2015-01-01

    Marine biomass diversity is a tremendous source of potential anticancer compounds. Several natural marine products have been described to restore tumor cell sensitivity to TNF-related apoptosis inducing ligand (TRAIL)-induced cell death. TRAIL is involved during tumor immune surveillance. Its selectivity for cancer cells has attracted much attention in oncology. This review aims at discussing the main mechanisms by which TRAIL signaling is regulated and presenting how marine bioactive compounds have been found, so far, to overcome TRAIL resistance in tumor cells. PMID:26580630

  17. Retinoids induce Nur77-dependent apoptosis in mouse thymocytes.

    PubMed

    Kiss, Beáta; Tóth, Katalin; Sarang, Zsolt; Garabuczi, Éva; Szondy, Zsuzsa

    2015-03-01

    Nur77 is a transcription factor, which plays a determinant role in mediating T cell receptor-induced cell death of thymocytes. In addition to regulation of transcription, Nur77 contributes to apoptosis induction by targeting mitochondria, where it can convert Bcl-2, an anti-apoptotic protein into a proapoptotic molecule. Previous studies have demonstrated that retinoids are actively produced in the mouse thymus and can induce a transcription-dependent apoptosis in mouse thymocytes. Here we show that retinoic acids induce the expression of Nur77, and retinoid-induced apoptosis is completely dependent on Nur77, as retinoids were unable to induce apoptosis in Nur77 null thymocytes. In wild-type thymocytes retinoids induced enhanced expression of the apoptosis-related genes FasL, TRAIL, NDG-1, Gpr65 and Bid, all of them in a Nur77-dependent manner. The combined action of these proteins led to Caspase 8-dependent Bid cleavage in the mitochondria. In addition, we could demonstrate the Nur77-dependent induction of STAT1 leading to enhanced Bim expression, and the mitochondrial translocation of Nur77 leading to the exposure of the Bcl-2/BH3 domain. The retinoid-induced apoptosis was dependent on both Caspase 8 and STAT1. Our data together indicate that retinoids induce a Nur77-dependent cell death program in thymocytes activating the mitochondrial pathway of apoptosis. PMID:25576519

  18. Dietary Yucca schidigera supplementation reduces arsenic-induced oxidative stress in Swiss albino mice.

    PubMed

    Ince, Sinan; Kucukkurt, Ismail; Turkmen, Ruhi; Demirel, Hasan Huseyin; Sever, Emine

    2013-11-01

    The aim of this study was to clarify the effects of dietary supplementation with Yucca schidigera (Ys) on lipid peroxidation (LPO), antioxidant activity, some biochemical parameters and histopathological changes in arsenic-exposed mice. Forty Swiss albino male mice were divided into five equal groups. Group I (control group) was given normal diet and tap water for 28 days. Group II (arsenic group) was given normal diet and 100 mg/L arsenic along with drinking water for 28 days. Groups III-V were given three different doses of Ys (50, 100 and 200 mg/kg) in supplemented diet and arsenic (100 mg/L) along with drinking water throughout the entire period of 28 days. The arsenic significantly increased serum biochemical parameters and malondialdehyde levels in blood and tissue. However, arsenic significantly decreased tissue glutathione concentration, erythrocyte superoxide dismutase and catalase activities. In contrast, dietary supplementation of Ys, in a dose-dependent manner, resulted in reversal of arsenic-induced oxidative stress, LPO and activities of antioxidant enzymes. Moreover, Ys also exhibited protective action against the arsenic-induced focal gliosis and hyperemi in brain, necrosis and degeneration in liver, degeneration and dilatation in Bowman's capsule of kidney and hyaline degeneration in heart tissue of mice. Consequently, our results demonstrate that Ys especially high-dose supplementation in diet decreases arsenic-induced oxidative stress and enhances the antioxidant defence mechanism and regenerate of tissues in Swiss albino mice. PMID:22609855

  19. Exercise Prevents Memory Impairment Induced by Arsenic Exposure in Mice: Implication of Hippocampal BDNF and CREB

    PubMed Central

    Yu, Zi-Jiang; Yu, Yan; Xiao, Chao-Lun; Kang, Chao-Sheng; Ge, Guo; Linghu, Yan; Zhu, Jun-De; Li, Yu-Mei; Li, Qiang-Ming; Luo, Shi-Peng; Yang, Dang; Li, Lin; Zhang, Wen-Yan; Tian, Guang

    2015-01-01

    High concentrations of arsenic, which can be occasionally found in drinking water, have been recognized as a global health problem. Exposure to arsenic can disrupt spatial memory; however, the underlying mechanism remains unclear. In the present study, we tested whether exercise could interfere with the effect of arsenic exposure on the long-term memory (LTM) of object recognition in mice. Arsenic (0, 1, 3, and 10 mg/ kg, i.g.) was administered daily for 12 weeks. We found that arsenic at dosages of 1, 3, and 10 mg/kg decreased body weight and increased the arsenic content in the brain. The object recognition LTM (tested 24 h after training) was disrupted by 3 mg/ kg and 10 mg/ kg, but not 1 mg/ kg arsenic exposure. Swimming exercise also prevented LTM impairment induced by 3 mg/ kg, but not with 10 mg/ kg, of arsenic exposure. The expression of brain-derived neurotrophic factor (BDNF) and phosphorylated cAMP-response element binding protein (pCREB) in the CA1 and dentate gyrus areas (DG) of the dorsal hippocampus were decreased by 3 mg/ kg and 10 mg/ kg, but not by 1 mg/ kg, of arsenic exposure. The decrease in BDNF and pCREB in the CA1 and DG induced by 3 mg/ kg, but not 10 mg/ kg, of arsenic exposure were prevented by swimming exercise. Arsenic exposure did not affect the total CREB expression in the CA1 or DG. Taken together, these results indicated that swimming exercise prevented the impairment of object recognition LTM induced by arsenic exposure, which may be mediated by BDNF and CREB in the dorsal hippocampus. PMID:26368803

  20. Mitochondrion-mediated apoptosis induced by photofrin-PDT

    NASA Astrophysics Data System (ADS)

    Wu, Yunxia; Xing, Da

    2007-05-01

    Apoptosis is an important cellular event that plays a key role in pathogeny and therapy of many diseases. The mechanisms of the initiation and regulation of PDT-induced apoptosis are complex. Some PDT-associated apoptosis pathways involved plasma membrane death receptors, mitochondria, lysosomes and endoplasmic reticulum (ER). In order to determine the apoptosis pathway induced by Photofrin-PDT, we used fluorescence resonance energy transfer (FRET) technique and probe SCAT3 to monitor the dynamics of caspase-3 activation after PDT treatment and also measured caspase-8 activity. With laser scanning confocal microscopy, we found that Photofrin were localized primarily in mitochondria, the primary targets of Photofrin-PDT. Formation of mitochondrial reactive oxygen species (ROS) was detected within minutes after PDT treatment. This was followed by mitochondrial membrane potential (ΔΨm), cytochrome c release, caspase-9 activity, caspase-3 activity and apoptosis. After PDT treatment, caspase-3 was activated rapidly while caspase-8 remained inactivated. Our results indicated that PDT-induced apoptosis was initiated from mitochondria pathway and independent of caspase-8 activation. The activation of caspase-3 by PDT started 20 minutes after treatment and completed in about 15 minutes. PDT-induced apoptosis is directly initiated from mitochondria pathway and not involved in the death receptors-dependent pathway. Our results demonstrated that FRET could be an effective tool to determine PDT-induced apoptosis and other cell death mechanism.

  1. Trauma patients’ elevated Tumor Necrosis Related Apoptosis Inducing Ligand (TRAIL) contributes to increased T cell apoptosis

    PubMed Central

    Bandyopadhyay, Gautam; Bankey, Paul E.; Miller-Graziano, Carol L.

    2012-01-01

    Immunosuppression resulting from excessive post-trauma apoptosis of hyperactivated Tcells is controversial. TRAIL mediated Tcell apoptosis decreases highly activated Tcells’ responses. Caspase-10, a particular TRAIL target, was increased in trauma patients’ Tcells with concomitantly elevated plasma TRAIL levels. These patients’ Tcells developed anergy, implicating increased TRAIL-mediated Tcell apoptosis in post-trauma Tcell anergy. Control Tcells cultured with patients’ sera containing high TRAIL levels increased their Caspase-10 activity and apoptosis. Stimulated primary Tcells are TRAIL apoptosis resistant. Increased plasma Thrombospondin-1 and Tcell expression of CD47, a Thrombospondin-1 receptor, preceded patients’ Tcell anergy. CD47 triggering of Tcells increased their sensitivity to TRAIL-induced apoptosis. Augmentation of Tcell TRAIL-induced apoptosis was secondary to CD47 triggered activation of the Src homology-containing phosphatase-1(SHP-1) and was partially blocked by a SHP-1 inhibitor. We suggest that combined post-trauma CD47 triggering, SHP-1 mediated NFκB suppression, and elevated TRAIL levels increase patients’ CD47 expressing Tcell apoptosis, thus contributing to subsequent Tcell anergy. PMID:22926077

  2. UXT plays dual opposing roles on SARM-induced apoptosis.

    PubMed

    Sethurathinam, Shalini; Singh, Laishram Pradeepkumar; Panneerselvam, Porkodi; Byrne, Bernadette; Ding, Jeak Ling

    2013-10-11

    Apoptosis is a vital defense mechanism for the clearance of infected cells. Ubiquitously expressed transcript (UXT), which exists in two isoforms (V1 and V2), interact with both apoptotic and cellular proteins. By yeast two-hybrid analysis, we found that UXT interacts with SARM (sterile α and HEAT armadillo motif-containing protein). Since SARM is a TLR adaptor which induces intrinsic apoptosis following immune activation, we were prompted to query whether UXT and SARM might co-regulate apoptosis. We found that the UXT isoforms elicit dual opposing regulatory effects on SARM-induced apoptosis; while UXT V1, co-expressed with SARM, caused a reduction in caspase 8 activity, UXT V2 strongly increased caspase 8 activity and enhanced SARM-induced apoptosis by activating the extrinsic pathway and depolarizing the mitochondria. PMID:24021647

  3. TRPV1 receptors mediate particulate matter-induced apoptosis.

    PubMed

    Agopyan, N; Head, J; Yu, S; Simon, S A

    2004-03-01

    Exposure to airborne particulate matter (PM) is a world-wide health problem mainly because it produces adverse cardiovascular and respiratory effects that frequently result in morbidity. Despite many years of epidemiological and basic research, the mechanisms underlying PM toxicity remain largely unknown. To understand some of these mechanisms, we measured PM-induced apoptosis and necrosis in normal human airway epithelial cells and sensory neurons from both wild-type mice and mice lacking TRPV1 receptors using Alexa Fluor 488-conjugated annexin V and propidium iodide labeling, respectively. Exposure of environmental PMs containing residual oil fly ash and ash from Mount St. Helens was found to induce apoptosis, but not necrosis, as a consequence of sustained calcium influx through TRPV1 receptors. Apoptosis was completely prevented by inhibiting TRPV1 receptors with capsazepine or by removing extracellular calcium or in sensory neurons from TRPV1(-/-) mice. Binding of either one of the PMs to the cell membrane induced a capsazepine-sensitive increase in cAMP. PM-induced apoptosis was augmented upon the inhibition of PKA. PKA inhibition on its own also induced apoptosis, thereby suggesting that this pathway may be endogenously protective against apoptosis. In summary, it was found that inhibiting TRPV1 receptors prevents PM-induced apoptosis, thereby providing a potential mechanism to reduce their toxicity. PMID:14633515

  4. ORGANIC AND INORGANIC ARSENICALS SENSITIZE HUMAN BRONCHIAL EPITHELIAL CELLS TO HYDROGEN PEROXIDE-INDUCED DNA DAMAGE

    EPA Science Inventory

    The lungs are a target organ for arsenic carcinogenesis, however, its mechanism of action remains unclear. Furthermore, it has been suggested that inorganic arsenic (iAs) can potentiate DNA damage induced by other agents. Once inside the human body iAs generally undergoes two ...

  5. Atherosclerosis induced by arsenic in drinking water in rats through altering lipid metabolism

    SciTech Connect

    Cheng, Tain-Junn; Chuu, Jiunn-Jye; Chang, Chia-Yu; Tsai, Wan-Chen; Chen, Kuan-Jung; Guo, How-Ran

    2011-10-15

    Arsenic in drinking water is a global environmental health problem, and the exposure may increase cardiovascular and cerebrovascular diseases mortalities, most likely through causing atherosclerosis. However, the mechanism of atherosclerosis formation after arsenic exposure is still unclear. To study the mechanism of atherosclerosis formation after arsenic exposure and explore the role of high cholesterol diet (HCD) in this process, we fed spontaneous hypertensive rats and Wistar Kyoto rats with basal diet or HCD and provided with them drinking water containing arsenic at different ages and orders for 20 consecutive weeks. We measured high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), total cholesterol, triglycerides, heat shock protein 70 (HSP 70), and high sensitive C-reactive protein (hs-CRP) at predetermined intervals and determined expressions of cholesteryl ester transfer protein-1 (CETP-1) and liver X receptor {beta} (LXR{beta}) in the liver. Atherosclerosis was determined by examining the aorta with hematoxylin and eosin stain. After 20 weeks, we found arsenic, alone or combined with HCD, may promote atherosclerosis formation with transient increases in HSP 70 and hs-CRP. Early combination exposure decreased the HDL-C/LDL-C ratio without changing the levels of total cholesterol and triglyceride until 30 weeks old. Both CETP-1 and LXR{beta} activities were suppressed, most significantly in early combination exposure. In conclusion, arsenic exposure may induce atherosclerosis through modifying reverse cholesterol transport in cholesterol metabolism and suppressing LXR{beta} and CEPT-1 expressions. For decreasing atherosclerosis related mortality associated with arsenic, preventing exposure from environmental sources in early life is an important element. - Highlights: > Arsenic causes cardiovascular and cerebrovascular diseases through atherosclerosis. > Arsenic may promote atherosclerosis with transient increase in HSP

  6. Characterization of radiation-induced Apoptosis in rodent cell lines

    SciTech Connect

    Guo, Min; Chen, Changhu; Ling, C.C.

    1997-03-01

    For REC:myc(ch1), Rat1 and Rat1:myc{sub b} cells, we determined the events in the development of radiation-induced apoptosis to be in the following order: cell division followed by chromatin condensation, membrane blebbing, loss of adhesion and the uptake of vital dye. Experimental data which were obtained using {sup 4}He ions of well defined energies and which compared the dependence of apoptosis and clonogenic survival on {sup 4}He range strongly suggested that in our cells both apoptosis and loss of clonogenic survival resulted from radiation damage to the cell nucleus. Corroboratory evidence was that BrdU incorporation sensitized these cells to radiation-induced apoptosis. Comparing the dose response for apoptosis and the clonogenic survival curves for Rat1 and Rat1:myc{sub b} cells, we concluded that radiation-induced cell inactivation as assayed by clonogenic survival, and that a modified linear-quadratic model, proposed previously, modeled such a contribution effectively. In the same context, the selective increase in radiation-induced apoptosis. Comparing the dose response for apoptosis and the clonogenic survival curves for Rat1 and Rat1:myc{sub b} cells, we concluded that radiation-induced apoptosis contributed to the overall radiation-induced cell inactivation as assayed by clonogenic survival, and that a modified linear-quadratic model, proposed previously, modeled such a contribution effectively. In the same context, the selective increase in radiation-induced apoptosis during late S and G{sub 2} phases reduced the relative radioresistance observed for clonogenic survival during late S and G{sub 2} phases. 30 refs., 8 figs.

  7. Metallothionein blocks oxidative DNA damage induced by acute inorganic arsenic exposure

    SciTech Connect

    Qu, Wei Waalkes, Michael P.

    2015-02-01

    We studied how protein metallothionein (MT) impacts arsenic-induced oxidative DNA damage (ODD) using cells that poorly express MT (MT-I/II double knockout embryonic cells; called MT-null cells) and wild-type (WT) MT competent cells. Arsenic (as NaAsO{sub 2}) was less cytolethal over 24 h in WT cells (LC{sub 50} = 11.0 ± 1.3 μM; mean ± SEM) than in MT-null cells (LC{sub 50} = 5.6 ± 1.2 μM). ODD was measured by the immuno-spin trapping method. Arsenic (1 or 5 μM; 24 h) induced much less ODD in WT cells (121% and 141% of control, respectively) than in MT-null cells (202% and 260%). In WT cells arsenic caused concentration-dependent increases in MT expression (transcript and protein), and in the metal-responsive transcription factor-1 (MTF-1), which is required to induce the MT gene. In contrast, basal MT levels were not detectable in MT-null cells and unaltered by arsenic exposure. Transfection of MT-I gene into the MT-null cells markedly reduced arsenic-induced ODD levels. The transport genes, Abcc1 and Abcc2 were increased by arsenic in WT cells but either showed no or very limited increases in MT-null cells. Arsenic caused increases in oxidant stress defense genes HO-1 and GSTα2 in both WT and MT-null cells, but to much higher levels in WT cells. WT cells appear more adept at activating metal transport systems and oxidant response genes, although the role of MT in these responses is unclear. Overall, MT protects against arsenic-induced ODD in MT competent cells by potential sequestration of scavenging oxidant radicals and/or arsenic. - Highlights: • Metallothionein blocks arsenic toxicity. • Metallothionein reduces arsenic-induced DNA damage. • Metallothionein may bind arsenic or radicals produced by arsenic.

  8. Modulation of Radiation-Induced Apoptosis by Thiolamines

    NASA Technical Reports Server (NTRS)

    Warters, R. L.; Roberts, J. C.; Wilmore, B. H.; Kelley, L. L.

    1997-01-01

    Exposure to the thiolamine radioprotector N-(2-mercaptoethyl)-1,3-propanediamine (WR-1065) induced apoptosis in the mouse TB8-3 hybridoma after 60-minute (LD(sub50) = 4.5mM) or during a 20-hour (LD(sub50) = 0.15 mM) exposure. In contrast, a 20-hour exposure to 17 mM L-cysteine or 10 mM cysteamine was required to induce 50 percent apoptosis within 20 hours. Apoptosis was not induced by either a 60-minute or 20-hour exposure to 10 mM of the thiazolidime prodrugs ribose-cysteine (RibCys) or ribose-cysteamine (RibCyst). Thiolamine-induced apoptosis appeared to be a p53-independent process since it was induced by WR-1065 exposure in human HL60 cells. Exposure to WR-1065 (4mM for 15 minutes) or cysteine (10mM for 60 minutes) before and during irradiation protected cells against the induction of both DNA double-strand breaks and apoptosis, while exposure to RibCys (10 mM for 3 hours) did not. Treatment with either WR-1065, cysteine, RibCys or RibCyst for 60 minutes beginning 60 minutes after irradiation did not affect the level of radiation-induced apoptosis. In contrast, treatment with either cysteine, cysteamine or RibCys for 20 hours beginning 60 minutes after irradiation enhanced radiation-induced apoptosis. Similar experiments could not be conducted with WR-1065 because of its extreme toxicity. Our results indicate that thiolamine enhancement of radiation-induced apoptosis is not involved in their previously reported capacity to reduce radiation-induced mutations.

  9. Actinobacillus actinomycetemcomitans induces apoptosis in human monocytic THP-1 cells.

    PubMed

    Kato, Satsuki; Sugimura, Norihiko; Nakashima, Keisuke; Nishihara, Tatsuji; Kowashi, Yusuke

    2005-03-01

    It has previously been reported that the murine macrophage cell line J774.1 and the human oral epithelial cell line KB undergo apoptosis as a result of Actinobacillus actinomycetemcomitans infection. Recent studies have demonstrated that apoptosis regulation is modulated by multiple phosphorylation of several different protein kinases, including the major subtypes of the mitogen-activated protein kinase (MAPK) family. The MAPK family promotes cell survival and/or proliferation in response to growth factor stimulation, or apoptosis in response to various stress stimuli. The primary objective of the present investigation was to clarify whether human immune cells undergo apoptosis following A. actinomycetemcomitans infection and, if so, to establish the involvement of the MAPK family. Human monocytic THP-1 cells were infected with A. actinomycetemcomitans in microtubes. Lactate dehydrogenase release into the culture supernatant and DNA fragmentation in the cells were monitored. DNA fragmentation was also identified by agarose gel electrophoresis. Cell death following A. actinomycetemcomitans infection occurred by apoptosis, shown by an increase in the proportion of fragmented DNA and the typical ladder pattern of DNA fragmentation indicative of apoptosis. Furthermore, p38 MAPK activity and tumour necrosis factor alpha (TNF-alpha) levels increased following A. actinomycetemcomitans infection. In contrast, cell death and TNF-alpha levels in infected cells decreased upon addition of a p38 inhibitor or an anti-TNF-alpha antibody. However, exogenous TNF-alpha could not induce apoptosis in uninfected THP-1 cells. Interestingly, p38 MAPK activity diminished in the presence of anti-TNF-alpha antibody. These findings indicated that A. actinomycetemcomitans infection induces apoptosis in THP-1 cells and that p38 MAPK activity is directly involved in apoptosis. TNF-alpha may play an indirect role in apoptosis via enhanced p38 MAPK activity. A. actinomycetemcomitans-induced

  10. Preventive effects of bicarbonate on cerivastatin-induced apoptosis.

    PubMed

    Kobayashi, Masaki; Kaido, Fumie; Kagawa, Toshiki; Itagaki, Shirou; Hirano, Takeshi; Iseki, Ken

    2007-08-16

    Although HMG-CoA reductase inhibitors such as statins are the most widely used cholesterol-lowering agents, there is a risk of myopathy or rhabdmyolysis occurring in patients taking these drugs. It has been reported that a number of lipophilic statins cause apoptosis in various cells, but it is still not clear whether intracellular acidification is involved in statin-induced apoptosis. There have been few studies aimed at identifying compounds that suppress statin-induced myotoxicity. In the present study, we examined the relationship between cerivastatin-induced apoptosis and intracellular acidification and the effect of bicarbonate on cerivastatin-induced apoptosis using an RD cell line as a model of in vitro skeletal muscle. Cerivastatin reduced the number of viable cells and caused dramatic morphological changes and DNA fragmentation in a concentration-dependent manner. Moreover, cerivastatin-induced apoptosis was associated with intracellular acidification and caspase-9 and -3/7 activation. On the other hand, bicarbonate suppressed cerivastatin-induced pH alteration, caspase activation, morphological change and reduction of cell viability. Accordingly, bicarbonate suppressed statin-induced apoptosis. The strategy to combine statins with bicarbonate can lead to reduction in the chance of the severe adverse events including myopathy or rhabdmyolysis. PMID:17553641

  11. Oxidative Stress and Replication-Independent DNA Breakage Induced by Arsenic in Saccharomyces cerevisiae

    PubMed Central

    Litwin, Ireneusz; Bocer, Tomasz; Dziadkowiec, Dorota; Wysocki, Robert

    2013-01-01

    Arsenic is a well-established human carcinogen of poorly understood mechanism of genotoxicity. It is generally accepted that arsenic acts indirectly by generating oxidative DNA damage that can be converted to replication-dependent DNA double-strand breaks (DSBs), as well as by interfering with DNA repair pathways and DNA methylation. Here we show that in budding yeast arsenic also causes replication and transcription-independent DSBs in all phases of the cell cycle, suggesting a direct genotoxic mode of arsenic action. This is accompanied by DNA damage checkpoint activation resulting in cell cycle delays in S and G2/M phases in wild type cells. In G1 phase, arsenic activates DNA damage response only in the absence of the Yku70–Yku80 complex which normally binds to DNA ends and inhibits resection of DSBs. This strongly indicates that DSBs are produced by arsenic in G1 but DNA ends are protected by Yku70–Yku80 and thus invisible for the checkpoint response. Arsenic-induced DSBs are processed by homologous recombination (HR), as shown by Rfa1 and Rad52 nuclear foci formation and requirement of HR proteins for cell survival during arsenic exposure. We show further that arsenic greatly sensitizes yeast to phleomycin as simultaneous treatment results in profound accumulation of DSBs. Importantly, we observed a similar response in fission yeast Schizosaccharomyces pombe, suggesting that the mechanisms of As(III) genotoxicity may be conserved in other organisms. PMID:23935510

  12. Phellinus linteus sensitises apoptosis induced by doxorubicin in prostate cancer

    PubMed Central

    Collins, L; Zhu, T; Guo, J; Xiao, Z J; Chen, C-Y

    2006-01-01

    It has been demonstrated that the Phellinus linteus (PL) mushroom, which mainly consists of polysaccharides, possesses antitumour activity. The mechanisms of PL against malignant growth remain unknown. The anticancer drug doxorubicin (Dox) has been shown to induce apoptosis via initiating a caspase cascade. In this investigation, we tested the effect of PL on Dox-induced apoptosis in prostate cancer LNCaP cells. We showed that PL or Dox, at relatively low doses, does not induce apoptosis in the cells. However, combination treatment with low doses of PL and Dox results in a synergistic effect on the induction of apoptosis. In this apoptotic process, caspases 8, 3 and BID are cleaved, and the addition of caspase inhibitor z-VADfmk completely blocks apoptosis. In addition, JNK is activated in response to PL or the combination treatment in LNCaP cells. The suppression of JNK partially inhibits the induction of apoptosis elicited by the co-treatment. These findings indicate that PL has a synergistic effect with Dox to activate caspases in prostate cancer LNCaP cells. Our study also suggests that PL has therapeutic potential to augment the magnitude of apoptosis induced by antiprostate cancer drugs. PMID:16868541

  13. Atorvastatin ameliorates arsenic-induced hypertension and enhancement of vascular redox signaling in rats

    SciTech Connect

    Sarath, Thengumpallil Sasindran; Waghe, Prashantkumar; Gupta, Priyanka; Choudhury, Soumen; Kannan, Kandasamy; Pillai, Ayyappan Harikrishna; Harikumar, Sankaran Kutty; Mishra, Santosh Kumar; Sarkar, Souvendra Nath

    2014-11-01

    Chronic arsenic exposure has been linked to elevated blood pressure and cardiovascular diseases, while statins reduce the incidence of cardiovascular disease predominantly by their low density lipoprotein-lowering effect. Besides, statins have other beneficial effects, including antioxidant and anti-inflammatory activities. We evaluated whether atorvastatin, a widely used statin, can ameliorate arsenic-induced increase in blood pressure and alteration in lipid profile and also whether the amelioration could relate to altered NO and ROS signaling. Rats were exposed to sodium arsenite (100 ppm) through drinking water for 90 consecutive days. Atorvastatin (10 mg/kg bw, orally) was administered once daily during the last 30 days of arsenic exposure. On the 91st day, blood was collected for lipid profile. Western blot of iNOS and eNOS protein, NO and 3-nitrotyrosine production, Nox-4 and p22Phox mRNA expression, Nox activity, ROS generation, lipid peroxidation and antioxidants were evaluated in thoracic aorta. Arsenic increased systolic, diastolic and mean arterial blood pressure, while it decreased HDL-C and increased LDL-C, total cholesterol and triglycerides in serum. Arsenic down-regulated eNOS and up-regulated iNOS protein expression and increased basal NO and 3-nitrotyrosine level. Arsenic increased aortic Nox-4 and p22Phox mRNA expression, Nox activity, ROS generation and lipid peroxidation. Further, arsenic decreased the activities of superoxide dismutase, catalase, and glutathione peroxidase and depleted aortic GSH content. Atorvastatin regularized blood pressure, improved lipid profile and attenuated arsenic-mediated redox alterations. The results demonstrate that atorvastatin has the potential to ameliorate arsenic-induced hypertension by improving lipid profile, aortic NO signaling and restoring vascular redox homeostasis. - Highlights: • Arsenic increased systolic, diastolic and mean arterial blood pressure and caused dyslipidemia. • Arsenic increased

  14. The Interplays between Autophagy and Apoptosis Induced by Enterovirus 71

    PubMed Central

    Wang, Bei; Wang, Tao; Wang, Ji; Huang, He; Wang, Jianwei; Jin, Qi; Zhao, Zhendong

    2013-01-01

    Background Enterovirus 71 (EV71) is the causative agent of human diseases with distinct severity, from mild hand, foot and mouth disease to severe neurological syndromes, such as encephalitis and meningitis. The lack of understanding of viral pathogenesis as well as lack of efficient vaccine and drugs against this virus impedes the control of EV71 infection. EV71 virus induces autophagy and apoptosis; however, the relationship between EV71-induced autophagy and apoptosis as well as the influence of autophagy and apoptosis on virus virulence remains unclear. Methodology/Principal Findings In this study, it was observed that the Anhui strain of EV71 induced autophagy and apoptosis in human rhabdomyosarcoma (RD-A) cells. Additionally, by either applying chemical inhibitors or knocking down single essential autophagic or apoptotic genes, inhibition of EV71 induced autophagy inhibited the apoptosis both at the autophagosome formation stage and autophagy execution stage. However, inhibition of autophagy at the stage of autophagosome and lysosome fusion promoted apoptosis. In reverse, the inhibition of EV71-induced apoptosis contributed to the conversion of microtubule-associated protein 1 light chain 3-I (LC3-I) to LC3-II and degradation of sequestosome 1 (SQSTM1/P62). Furthermore, the inhibition of autophagy in the autophagsome formation stage or apoptosis decreased the release of EV71 viral particles. Conclusions/Significance In conclusion, the results of this study not only revealed novel aspect of the interplay between autophagy and apoptosis in EV71 infection, but also provided a new insight to control EV71 infection. PMID:23437282

  15. ATP depletion inhibits glucocorticoid-induced thymocyte apoptosis.

    PubMed Central

    Stefanelli, C; Bonavita, F; Stanic', I; Farruggia, G; Falcieri, E; Robuffo, I; Pignatti, C; Muscari, C; Rossoni, C; Guarnieri, C; Caldarera, C M

    1997-01-01

    In quiescent thymocytes, mitochondrial de-energization was not correlated to apoptotic death. In fact, thymocytes treated with oligomycin, a highly specific inhibitor of ATP synthase, alone or with atractyloside to block ATP translocation from the cytoplasm, were alive, even if their mitochondria were depolarized, as revealed by flow cytometry after Rhodamine 123 staining. Furthermore, oligomycin was a powerful inhibitor of apoptosis induced in rat thymocytes by dexamethasone and, to a lesser extent, by the calcium ionophore A23187 and etoposide, but was without effect when apoptosis was induced by staurosporine, and increased cell death in mitogen-treated thymocytes. The inhibition of apoptosis was confirmed by morphological criteria, inhibition of inter-nucleosomal DNA fragmentation and inhibition of the loss of membrane integrity. The anti-apoptotic effect of oligomycin in cells treated with A23187 or etoposide was correlated to the inhibition of protein synthesis, while inhibition of apoptosis induced by dexamethasone, already evident at an oligomycin concentration of 10 ng/ml, was instead strictly correlated to the effect exerted on the cellular ATP level. Thymocyte apoptosis triggered by dexamethasone was blocked or delayed by inhibitors of respiratory-chain uncouplers, inhibitors of ATP synthase and antioxidants: a lasting protection from dexamethasone-induced apoptosis was always correlated to a drastic and rapid reduction in ATP level (31-35% of control), while a delay in the death process was characterized by a moderate decrease in ATP (73-82% of control). Oligomycin inhibited the specific binding of radioactive corticosteroid to thymocyte nuclei, confirming the inhibitory effect of ATP depletion on glucocorticoid binding and suggesting that ATP depletion is a common mediator of the anti-apoptotic action of different effectors in glucocorticoid-induced apoptosis. In conclusion, the reported data indicate that ATP may act as a cellular modulator of some

  16. ATP depletion inhibits glucocorticoid-induced thymocyte apoptosis.

    PubMed

    Stefanelli, C; Bonavita, F; Stanic', I; Farruggia, G; Falcieri, E; Robuffo, I; Pignatti, C; Muscari, C; Rossoni, C; Guarnieri, C; Caldarera, C M

    1997-03-15

    In quiescent thymocytes, mitochondrial de-energization was not correlated to apoptotic death. In fact, thymocytes treated with oligomycin, a highly specific inhibitor of ATP synthase, alone or with atractyloside to block ATP translocation from the cytoplasm, were alive, even if their mitochondria were depolarized, as revealed by flow cytometry after Rhodamine 123 staining. Furthermore, oligomycin was a powerful inhibitor of apoptosis induced in rat thymocytes by dexamethasone and, to a lesser extent, by the calcium ionophore A23187 and etoposide, but was without effect when apoptosis was induced by staurosporine, and increased cell death in mitogen-treated thymocytes. The inhibition of apoptosis was confirmed by morphological criteria, inhibition of inter-nucleosomal DNA fragmentation and inhibition of the loss of membrane integrity. The anti-apoptotic effect of oligomycin in cells treated with A23187 or etoposide was correlated to the inhibition of protein synthesis, while inhibition of apoptosis induced by dexamethasone, already evident at an oligomycin concentration of 10 ng/ml, was instead strictly correlated to the effect exerted on the cellular ATP level. Thymocyte apoptosis triggered by dexamethasone was blocked or delayed by inhibitors of respiratory-chain uncouplers, inhibitors of ATP synthase and antioxidants: a lasting protection from dexamethasone-induced apoptosis was always correlated to a drastic and rapid reduction in ATP level (31-35% of control), while a delay in the death process was characterized by a moderate decrease in ATP (73-82% of control). Oligomycin inhibited the specific binding of radioactive corticosteroid to thymocyte nuclei, confirming the inhibitory effect of ATP depletion on glucocorticoid binding and suggesting that ATP depletion is a common mediator of the anti-apoptotic action of different effectors in glucocorticoid-induced apoptosis. In conclusion, the reported data indicate that ATP may act as a cellular modulator of some

  17. Apoptosis in vascular cells induced by cold atmospheric plasma treatment

    NASA Astrophysics Data System (ADS)

    Sladek, Raymond; Stoffels, Eva

    2006-10-01

    Apoptosis is a natural mechanism of cellular self-destruction. It can be triggered by moderate, yet irreversible damage. Apoptosis plays a major role in tissue renewal. Artificial apoptosis induction will become a novel therapy that meets all requirements for tissue-saving surgery. Diseased tissues can disappear without inflammation and scarring. This is particularly important in treatment of blockages in body tracts (e.g. cardiovascular diseases). Artificial induction of apoptosis can be achieved by means of cold plasma treatment. In this work an atmospheric micro-plasma operated in helium/air has been used to induce apoptosis in vascular cells. Parametric studies of apoptosis induction have been conducted; the efficiency is almost 100%. The apoptotic factors are ROS/RNS (reactive oxygen and nitrogen species). Their densities in the plasma have been measured by mass spectrometry. For apoptosis induction, RNS seem to be more important than ROS, because of their relative abundance. Moreover, addition of a ROS scavenger (ascorbic acid) to the cell culture medium does not reduce the occurrence of apoptosis. Cold plasma is a very efficient tool for fundamental studies of apoptosis, and later, for controlled tissue removal in vivo.

  18. Apoptosis signal-regulating kinase 1 mediates denbinobin-induced apoptosis in human lung adenocarcinoma cells

    PubMed Central

    Kuo, Chen-Tzu; Chen, Bing-Chang; Yu, Chung-Chi; Weng, Chih-Ming; Hsu, Ming-Jen; Chen, Chien-Chih; Chen, Mei-Chieh; Teng, Che-Ming; Pan, Shiow-Lin; Bien, Mauo-Ying; Shih, Chung-Hung; Lin, Chien-Huang

    2009-01-01

    In the present study, we explore the role of apoptosis signal-regulating kinase 1 (ASK1) in denbinobin-induced apoptosis in human lung adenocarcinoma (A549) cells. Denbinobin-induced cell apoptosis was attenuated by an ASK1 dominant-negative mutant (ASK1DN), two antioxidants (N-acetyl-L-cysteine (NAC) and glutathione (GSH)), a c-Jun N-terminal kinase (JNK) inhibitor (SP600125), and an activator protein-1 (AP-1) inhibitor (curcumin). Treatment of A549 cells with denbinobin caused increases in ASK1 activity and reactive oxygen species (ROS) production, and these effects were inhibited by NAC and GSH. Stimulation of A549 cells with denbinobin caused JNK activation; this effect was markedly inhibited by NAC, GSH, and ASK1DN. Denbinobin induced c-Jun phosphorylation, the formation of an AP-1-specific DNA-protein complex, and Bim expression. Bim knockdown using a bim short interfering RNA strategy also reduced denbinobin-induced A549 cell apoptosis. The denbinobin-mediated increases in c-Jun phosphorylation and Bim expression were inhibited by NAC, GSH, SP600125, ASK1DN, JNK1DN, and JNK2DN. These results suggest that denbinobin might activate ASK1 through ROS production to cause JNK/AP-1 activation, which in turn induces Bim expression, and ultimately results in A549 cell apoptosis. PMID:19405983

  19. Integrated proteomics and metabolomics analysis of rat testis: Mechanism of arsenic-induced male reproductive toxicity

    PubMed Central

    Huang, Qingyu; Luo, Lianzhong; Alamdar, Ambreen; Zhang, Jie; Liu, Liangpo; Tian, Meiping; Eqani, Syed Ali Musstjab Akber Shah; Shen, Heqing

    2016-01-01

    Arsenic is a widespread metalloid in environment, whose exposure has been associated with a broad spectrum of toxic effects. However, a global view of arsenic-induced male reproductive toxicity is still lack, and the underlying mechanisms remain largely unclear. Our results revealed that arsenic exposure decreased testosterone level and reduced sperm quality in rats. By conducting an integrated proteomics and metabolomics analysis, the present study aims to investigate the global influence of arsenic exposure on the proteome and metabolome in rat testis. The abundance of 70 proteins (36 up-regulated and 34 down-regulated) and 13 metabolites (8 increased and 5 decreased) were found to be significantly altered by arsenic treatment. Among these, 19 proteins and 2 metabolites were specifically related to male reproductive system development and function, including spermatogenesis, sperm function and fertilization, fertility, internal genitalia development, and mating behavior. It is further proposed that arsenic mainly impaired spermatogenesis and fertilization via aberrant modulation of these male reproduction-related proteins and metabolites, which may be mediated by the ERK/AKT/NF-κB-dependent signaling pathway. Overall, these findings will aid our understanding of the mechanisms responsible for arsenic-induced male reproductive toxicity, and from such studies useful biomarkers indicative of arsenic exposure could be discovered. PMID:27585557

  20. Reduced LINE-1 methylation is associated with arsenic-induced genotoxic stress in children.

    PubMed

    Bandyopadhyay, Apurba K; Paul, Somnath; Adak, Shanta; Giri, Ashok K

    2016-08-01

    Early life exposure to arsenic has profound effect towards development of arsenic induced toxic outcomes. Some districts in the state of West Bengal, India are highly affected by arsenic, mainly through ground water. In children, not much of the toxic outcomes like dermatological lesions are observed but it is thought that the exposure leads to transient alteration in their biological processes that leads to various deleterious health effects later on. We evaluated the global methylation status by analyzing the LINE-1 methylation profile in children from arsenic exposed region between the age group 5-15 years along with the cytogenetic stress induced by arsenic as measured by lymphocyte micronucleus (MN) frequency. A total of 52 arsenic exposed and 32 unexposed children were analyzed. Whole blood DNA was used to measure the LINE-1 methylation by qRT-MSP. We found a significant association of MN-frequency in exposed individuals with highly depleted LINE-1 methylation compared to the exposed individuals with near baseline (which was comparable to unexposed control) methylation index as well as with those with the hypermethylated LINE-1 promoters. From our results, we interpret that LINE-1 methylation index may serve as a potent global epigenetic mark to detect the degree of arsenic genotoxicity at a very early age. We propose that this may be utilized to determine the extent of toxic influence exerted by arsenic, from a very early age. PMID:27465741

  1. Integrated proteomics and metabolomics analysis of rat testis: Mechanism of arsenic-induced male reproductive toxicity.

    PubMed

    Huang, Qingyu; Luo, Lianzhong; Alamdar, Ambreen; Zhang, Jie; Liu, Liangpo; Tian, Meiping; Eqani, Syed Ali Musstjab Akber Shah; Shen, Heqing

    2016-01-01

    Arsenic is a widespread metalloid in environment, whose exposure has been associated with a broad spectrum of toxic effects. However, a global view of arsenic-induced male reproductive toxicity is still lack, and the underlying mechanisms remain largely unclear. Our results revealed that arsenic exposure decreased testosterone level and reduced sperm quality in rats. By conducting an integrated proteomics and metabolomics analysis, the present study aims to investigate the global influence of arsenic exposure on the proteome and metabolome in rat testis. The abundance of 70 proteins (36 up-regulated and 34 down-regulated) and 13 metabolites (8 increased and 5 decreased) were found to be significantly altered by arsenic treatment. Among these, 19 proteins and 2 metabolites were specifically related to male reproductive system development and function, including spermatogenesis, sperm function and fertilization, fertility, internal genitalia development, and mating behavior. It is further proposed that arsenic mainly impaired spermatogenesis and fertilization via aberrant modulation of these male reproduction-related proteins and metabolites, which may be mediated by the ERK/AKT/NF-κB-dependent signaling pathway. Overall, these findings will aid our understanding of the mechanisms responsible for arsenic-induced male reproductive toxicity, and from such studies useful biomarkers indicative of arsenic exposure could be discovered. PMID:27585557

  2. Glucocorticoid Induced Leucine Zipper inhibits apoptosis of cardiomyocytes by doxorubicin

    SciTech Connect

    Aguilar, David; Strom, Joshua; Chen, Qin M.

    2014-04-01

    Doxorubicin (Dox) is an indispensable chemotherapeutic agent for the treatment of various forms of neoplasia such as lung, breast, ovarian, and bladder cancers. Cardiotoxicity is a major concern for patients receiving Dox therapy. Previous work from our laboratory indicated that glucocorticoids (GCs) alleviate Dox-induced apoptosis in cardiomyocytes. Here we have found Glucocorticoid-Induced Leucine Zipper (GILZ) to be a mediator of GC-induced cytoprotection. GILZ was found to be induced in cardiomyocytes by GC treatment. Knocking down of GILZ using siRNA resulted in cancelation of GC-induced cytoprotection against apoptosis by Dox treatment. Overexpressing GILZ by transfection was able to protect cells from apoptosis induced by Dox as measured by caspase activation, Annexin V binding and morphologic changes. Western blot analyses indicate that GILZ overexpression prevented cytochrome c release from mitochondria and cleavage of caspase-3. When bcl-2 family proteins were examined, we found that GILZ overexpression causes induction of the pro-survival protein Bcl-xL. Since siRNA against Bcl-xL reverses GC induced cytoprotection, Bcl-xL induction represents an important event in GILZ-induced cytoprotection. Our data suggest that GILZ functions as a cytoprotective gene in cardiomyocytes. - Highlights: • Corticosteroids act as a cytoprotective agent in cardiomyocytes • Corticosteroids induce GILZ expression in cardiomyocytes • Elevated GILZ results in resistance against apoptosis induced by doxorubicin • GILZ induces Bcl-xL protein without inducing Bcl-xL mRNA.

  3. Arsenic-induced cell proliferation is associated with enhanced ROS generation, Erk signaling and CyclinA expression.

    PubMed

    Chowdhury, Rajdeep; Chatterjee, Raghunath; Giri, Ashok K; Mandal, Chitra; Chaudhuri, Keya

    2010-10-01

    Arsenic is a well-established human carcinogen; however molecular mechanisms to arsenic-induced carcinogenesis are complex and elusive. The present study identifies a potential biomarker of arsenic exposure, and redefines arsenic-induced signaling in stimulation of cell proliferation. The effect of arsenic exposure on gene expression was evaluated in PBMC of arsenic-exposed individuals selected from a severely affected district of West Bengal, India. A novel, un-documented biomarker of arsenic exposure, CyclinA was identified by microarray analysis from the study. Non-transformed cell lines HaCat and Int407 when exposed to clinically achievable arsenic concentration showed significant increase of CyclinA substantiating the clinical data. An associated increase in S phase population of cells in cell cycle, indicative of enhanced proliferation was also noticed. On further investigation of the pathway to arsenic-induced proliferation, we observed that arsenic resulted: ROS generation; activated Erk signaling; stimulated AP-1 activity, including immediate early genes, c-Jun and c-Fos. N-Acetyl-l-cysteine, a ROS quencher, blocked the arsenic-induced effects. Our study underlines a previously undefined mechanism by which arsenic imparts its toxicity and results in uncontrolled cell proliferation. PMID:20654705

  4. Recovering drug-induced apoptosis subnetwork from Connectivity Map data.

    PubMed

    Yu, Jiyang; Putcha, Preeti; Silva, Jose M

    2015-01-01

    The Connectivity Map (CMAP) project profiled human cancer cell lines exposed to a library of anticancer compounds with the goal of connecting cancer with underlying genes and potential treatments. Since the therapeutic goal of most anticancer drugs is to induce tumor-selective apoptosis, it is critical to understand the specific cell death pathways triggered by drugs. This can help to better understand the mechanism of how cancer cells respond to chemical stimulations and improve the treatment of human tumors. In this study, using CMAP microarray data from breast cancer cell line MCF7, we applied a Gaussian Bayesian network modeling approach and identified apoptosis as a major drug-induced cellular-pathway. We then focused on 13 apoptotic genes that showed significant differential expression across all drug-perturbed samples to reconstruct the apoptosis network. In our predicted subnetwork, 9 out of 15 high-confidence interactions were validated in the literature, and our inferred network captured two major cell death pathways by identifying BCL2L11 and PMAIP1 as key interacting players for the intrinsic apoptosis pathway and TAXBP1 and TNFAIP3 for the extrinsic apoptosis pathway. Our inferred apoptosis network also suggested the role of BCL2L11 and TNFAIP3 as "gateway" genes in the drug-induced intrinsic and extrinsic apoptosis pathways. PMID:25883971

  5. Molecular mechanisms of nutlin-induced apoptosis in multiple myeloma

    PubMed Central

    Saha, Manujendra N; Jiang, Hua

    2010-01-01

    Multiple myeloma (MM) is an incurable plasma cell malignancy in which p53 is rarely mutated. Thus, activation of the p53 pathway by a small molecule inhibitor of the p53-MDM2 interaction, nutlin, in MM cells retaining wild type p53 is an attractive therapeutic strategy. Recently we reported that nutlin plus velcade (a proteasome inhibitor) displayed a synergistic response in MM. However, the mechanism of the p53-mediated apoptosis in MM has not been fully understood. Our data show that nutlin-induced apoptosis correlated with reduction in cell viability, upregulation of p53, p21 and MDM2 protein levels with a simultaneous increase in pro-apoptotic targets PUMA, Bax and Bak and downregulation of anti-apoptotic targets Bcl2 and survivin and activation of caspase in MM cells harboring wild type p53. Nutlin-induced apoptosis was inhibited when activation of caspase was blocked by the caspase inhibitor. Nutlin caused mitochondrial translocation of p53 where it binds with Bcl2, leading to cytochrome C release. Moreover, blocking the transcriptional arm of p53 by the p53-specific transcriptional inhibitor, pifithrin-α, not only inhibited nutlin-induced upregulation of p53-transcriptional targets but also augmented apoptosis in MM cells, suggesting an association of transcription-independent pathway of apoptosis. However, inhibitor of mitochondrial translocation of p53, PFT-µ, did not prevent nutlin-induced apoptosis, suggesting that the p53 transcription-dependent pathway was also operational in nutlin-induced apoptosis in MM. Our study provides the evidence that nutlin-induced apoptosis in MM cells is mediated by transcription-dependent and -independent pathways and supports further clinical evaluation of nutlin as a novel therapeutic agent in MM. PMID:20595817

  6. Ketamine-induced apoptosis in cultured rat cortical neurons

    SciTech Connect

    Takadera, Tsuneo . E-mail: t-takadera@hokuriku-u.ac.jp; Ishida, Akira; Ohyashiki, Takao

    2006-01-15

    Recent data suggest that anesthetic drugs cause neurodegeneration during development. Ketamine is frequently used in infants and toddlers for elective surgeries. The purpose of this study is to determine whether glycogen synthase kinase-3 (GSK-3) is involved in ketamine-induced apoptosis. Ketamine increased apoptotic cell death with morphological changes which were characterized by cell shrinkage, nuclear condensation or fragmentation. In addition, insulin growth factor-1 completely blocked the ketamine-induced apoptotic cell death. Ketamine decreased Akt phosphorylation. GSK-3 is known as a downstream target of Akt. The selective inhibitors of GSK-3 prevented the ketamine-induced apoptosis. Moreover, caspase-3 activation was accompanied by the ketamine-induced cell death and inhibited by the GSK-3 inhibitors. These results suggest that activation of GSK-3 is involved in ketamine-induced apoptosis in rat cortical neurons.

  7. High fat diet aggravates arsenic induced oxidative stress in rat heart and liver.

    PubMed

    Dutta, Mousumi; Ghosh, Debosree; Ghosh, Arnab Kumar; Bose, Gargi; Chattopadhyay, Aindrila; Rudra, Smita; Dey, Monalisa; Bandyopadhyay, Arkita; Pattari, Sanjib K; Mallick, Sanjaya; Bandyopadhyay, Debasish

    2014-04-01

    Arsenic is a well known global groundwater contaminant. Exposure of human body to arsenic causes various hazardous effects via oxidative stress. Nutrition is an important susceptible factor which can affect arsenic toxicity by several plausible mechanisms. Development of modern civilization led to alteration in the lifestyle as well as food habits of the people both in urban and rural areas which led to increased use of junk food containing high level of fat. The present study was aimed at investigating the effect of high fat diet on heart and liver tissues of rats when they were co-treated with arsenic. This study was established by elucidating heart weight to body weight ratio as well as analysis of the various functional markers, oxidative stress biomarkers and also the activity of the antioxidant enzymes. Histological analysis confirmed the biochemical investigations. From this study it can be concluded that high fat diet increased arsenic induced oxidative stress. PMID:24508525

  8. Arsenic-induced toxicity and the protective role of ascorbic acid in mouse testis

    SciTech Connect

    Chang, Soo Im; Jin, Bohwan; Youn, Pilju; Park, Changbo; Park, Jung-Duck; Ryu, Doug-Young . E-mail: dyryu@snu.ac.kr

    2007-01-15

    Oxidative stress has been suggested to be a major cause of male reproductive failure. Here, we investigated whether arsenic, which impairs male reproductive functions in rodent models, acts by inducing oxidative stress. Male 8-week-old ICR mice were given drinking water containing 20 or 40 mg/l sodium arsenite with or without 0.75 or 1.5 g/l of the antioxidant ascorbic acid for 5 weeks. The arsenic-treated mice showed decreased epididymidal sperm counts and testicular weights compared to untreated mice. These effects were reversed in mice that were co-treated with ascorbic acid. Similarly, arsenic treatment lowered the activities of testicular 3{beta}-hydroxysteroid dehydrogenase (HSD) and 17{beta}-HSD, which play important roles in steroidogenesis, and this was reversed by co-treatment with ascorbic acid. The testicles of arsenic-treated mice had decreased glutathione (GSH) levels (which correlate inversely with the degree of cellular oxidative stress) and elevated levels of protein carbonyl (a marker of oxidative damage to tissue proteins). Ascorbic acid co-treatment reversed both of these effects. Thus, ascorbic acid blocks both the adverse effects of arsenic on male reproductive functions and the arsenic-induced testicular oxidative changes. These observations support the notion that arsenic impairs male reproductive function by inducing oxidative stress.

  9. Apoptosis induced by dioscin in Hela cells.

    PubMed

    Cai, Jing; Liu, Mingjie; Wang, Zhao; Ju, Yong

    2002-02-01

    Dioscin, a saponin extracted from the root of Polygonatum Zanlanscianense Pamp, markedly inhibited proliferation of Hela cells. The results indicated that Hela cells underwent apoptosis in dose- and time-dependent manners when treated with Dioscin. Caspase-3, -8 and -9 activities were also detected. The low enzymatic activity of caspase-8 and high activity of caspase-9 showed that the mitochondrial pathway was activated in apoptosis. The reduced expression of the survival protein Bcl-2 also confirmed this result. These studies may be significant in finding a new drug to treat human cervical cancer. PMID:11853164

  10. Subhepatotoxic exposure to arsenic enhances lipopolysaccharide-induced liver injury in mice

    PubMed Central

    Arteel, Gavin E.; Guo, Luping; Schlierf, Thomas; Beier, Juliane I; Kaiser, J. Phillip; Chen, Theresa S; Liu, Marsha; Conklin, Daniel P.; Miller, Heather L.; von Montfort, Claudia; States, J. Christopher

    2008-01-01

    Exposure to arsenic via drinking water is a serious health concern in the US. Whereas studies have identified arsenic alone as an independent risk factor for liver disease, concentrations of arsenic required to damage this organ are generally higher than found in the US water supply. The purpose of the current study was to test the hypothesis that arsenic (at subhepatotoxic doses) may also sensitize the liver to a second hepatotoxin. To test this hypothesis, the effect of chronic exposure to arsenic on liver damage caused by acute lipopolysaccharide (LPS) was determined in mice. Male C57Bl/6J mice (4-6 weeks) were exposed to arsenic (49 ppm as sodium arsenite in drinking water). After 7 months of exposure, animals were injected with LPS (10 mg/kg i.p.) and sacrificed 24 h later. Arsenic alone caused no overt hepatotoxicity, as determined by plasma enzymes and histology. In contrast, arsenic exposure dramatically enhanced liver damage caused by LPS, increasing the number and size of necroinflammatory foci. This effect of arsenic was coupled with increases in indices of oxidative stress (4-HNE adducts, depletion of GSH and methionine pools). The number of apoptotic (TUNEL) hepatocytes was similar in the LPS and arsenic/LPS groups. In contrast, arsenic pre-exposure blunted the increase in proliferating (PCNA) hepatocytes caused by LPS; this change in the balance between cell death and proliferation was coupled with a robust loss of liver weight in the arsenic/LPS compared to the LPS alone group. The impairment of proliferation after LPS caused by arsenic was also coupled with alterations in the expression of key mediators of cell cycle progression (p27, p21, CDK6 and Cyclin D1). Taken together, these results suggest that arsenic, at doses that are not overtly hepatotoxic per se, significantly enhances LPS-induced liver injury. These results further suggest that arsenic levels in the drinking water may be a risk modifier for the development of chronic liver diseases

  11. Enhanced protective activity of nano formulated andrographolide against arsenic induced liver damage.

    PubMed

    Das, Sujata; Pradhan, Goutam Kumar; Das, Subhadip; Nath, Debjani; Das Saha, Krishna

    2015-12-01

    Chronic exposure to arsenic over a period of time induces toxicity, primarily in liver but gradually in all systems of the body. Andrographolide (AG), a major diterpene lactone of Andrographis paniculata, shows a wide array of physiological functions including hepatoprotection. Therapeutic applications of AG are however seriously constrained because of its insolubility, poor bioavailability, and short plasma half-life. Nanoparticulation of AG is a possible solution to these problems. In the present study we investigated the effectiveness of polylactide co-glycolide (PLGA) nanocapsulated andrographolide (NA) against arsenic induced liver damage in mice. NA of average diameter 65.8 nm and encapsulation efficiency of 64% were prepared. Sodium arsenite at a dose of 40 mg/L supplied via drinking water in mice significantly raised the serum level of liver function markers such as AST, ALT, and ALP, and caused arsenic deposition in liver and ROS generation, though it did not show any lethality up to 30 days of exposure. However, even liver toxicity was not observed when mice were given AG and NA orally at doses up to 100 mg/kg bwt and 20 mg/kg bwt respectively on alternate days for one month. Treatment of non-toxic doses of AG or NA on alternate days along with arsenic significantly decreased the arsenic induced elevation of the serum level of ALT, AST and ALP, and arsenic deposition in liver. AG and NA increased the level of hepatic antioxidant enzymes such as superoxide dismutase (SOD), and catalase (CAT), and the level of reduced glutathione (GSH). Also, the ROS level was lowered in mice exposed to arsenic but treated with AG or NA. Protective efficiency of NA is about five times more than that of AG. Administration of NA to arsenic-treated mice caused signs of improvement in liver tissue architecture. In conclusion, the results of this study suggest that NA could be beneficial against arsenic-induced liver toxicity. PMID:26485141

  12. Systematic identification of arsenic-binding proteins reveals that hexokinase-2 is inhibited by arsenic

    PubMed Central

    Zhang, Hai-nan; Yang, Lina; Ling, Jian-ya; Czajkowsky, Daniel M.; Wang, Jing-Fang; Zhang, Xiao-Wei; Zhou, Yi-Ming; Ge, Feng; Yang, Ming-kun; Xiong, Qian; Guo, Shu-Juan; Le, Huang-Ying; Wu, Song-Fang; Yan, Wei; Liu, Bingya; Zhu, Heng; Chen, Zhu; Tao, Sheng-ce

    2015-01-01

    Arsenic is highly effective for treating acute promyelocytic leukemia (APL) and has shown significant promise against many other tumors. However, although its mechanistic effects in APL are established, its broader anticancer mode of action is not understood. In this study, using a human proteome microarray, we identified 360 proteins that specifically bind arsenic. Among the most highly enriched proteins in this set are those in the glycolysis pathway, including the rate-limiting enzyme in glycolysis, hexokinase-1. Detailed biochemical and metabolomics analyses of the highly homologous hexokinase-2 (HK2), which is overexpressed in many cancers, revealed significant inhibition by arsenic. Furthermore, overexpression of HK2 rescued cells from arsenic-induced apoptosis. Our results thus strongly implicate glycolysis, and HK2 in particular, as a key target of arsenic. Moreover, the arsenic-binding proteins identified in this work are expected to serve as a valuable resource for the development of synergistic antitumor therapeutic strategies. PMID:26598702

  13. Arsenic toxicity induced endothelial dysfunction and dementia: Pharmacological interdiction by histone deacetylase and inducible nitric oxide synthase inhibitors

    SciTech Connect

    Sharma, Bhupesh Sharma, P.M.

    2013-11-15

    Arsenic toxicity has been reported to damage all the major organs including the brain and vasculature. Dementia including Alzheimer's disease (AD) and vascular dementia (VaD) are posing greater risk to the world population as it is now increasing at a faster rate. We have investigated the role of sodium butyrate, a selective histone deacetylase (HDAC) inhibitor and aminoguanidine, a selective inducible nitric oxide synthase (iNOS) inhibitor in pharmacological interdiction of arsenic toxicity induced vascular endothelial dysfunction and dementia in rats. Arsenic toxicity was done by administering arsenic drinking water to rats. Morris water-maze (MWM) test was used for assessment of learning and memory. Endothelial function was assessed using student physiograph. Oxidative stress (aortic superoxide anion, serum and brain thiobarbituric acid reactive species, brain glutathione) and nitric oxide levels (serum nitrite/nitrate) were also measured. Arsenic treated rats have shown impairment of endothelial function, learning and memory, reduction in serum nitrite/nitrate and brain GSH levels along with increase in serum and brain TBARS. Sodium butyrate as well as aminoguanidine significantly convalesce arsenic induced impairment of learning, memory, endothelial function, and alterations in various biochemical parameters. It may be concluded that arsenic induces endothelial dysfunction and dementia, whereas, sodium butyrate, a HDAC inhibitor as well as aminoguanidine, a selective iNOS inhibitor may be considered as potential agents for the management of arsenic induced endothelial dysfunction and dementia. - Highlights: • As has induced endothelial dysfunction (Edf) and vascular dementia (VaD). • As has increased oxidative stress, AChE activity and decreased serum NO. • Inhibitors of HDAC and iNOS have attenuated As induced Edf and VaD. • Both the inhibitors have attenuated As induced biochemical changes. • Inhibitor of HDAC and iNOS has shown good potential in

  14. Antioxidants induce apoptosis of rat ovarian theca-interstitial cells.

    PubMed

    Rzepczynska, Izabela J; Foyouzi, Nastaran; Piotrowski, Piotr C; Celik-Ozenci, Ciler; Cress, Amanda; Duleba, Antoni J

    2011-01-01

    Regulation of growth of ovarian theca-interstitial tissues is essential for normal ovarian development and function. Reactive oxygen species are involved in modulation of signal transduction pathways, including regulation of tissue growth and apoptosis. Previously, we have demonstrated that antioxidants inhibit proliferation of theca-interstitial cells. This report evaluates the effects of antioxidants on apoptosis of rat theca-interstitial cells. The cells were cultured in chemically defined media without or with vitamin E succinate and ebselen. Apoptosis was evaluated by cytochemical assessment of nuclear morphology, activity of executioner caspases 3 and 7, and determination of staining with annexin V in combination with propidium iodide. Both tested antioxidants induced significant morphological changes consistent with apoptosis, including chromatin condensation, nuclear shrinkage, and pyknosis. Antioxidants also induced other hallmarks of apoptosis including increased activity of caspases 3/7 as well as increased staining with annexin V. The present findings demonstrate that antioxidants with distinctly different mechanisms of action induce a series of events consistent with the process of apoptosis in ovarian mesenchyme. These observations may be of translational-clinical relevance, providing mechanistic support for the use of antioxidants in the treatment of PCOS, a condition associated with excessive growth and activity of theca-interstitial cells. PMID:20844276

  15. X-ray-induced cell death: Apoptosis and necrosis

    SciTech Connect

    Nakano, Hisako; Shinohara, Kunio

    1994-10-01

    X-ray-induced cell death in MOLT-4N1, a subclone of MOLT-4 cells, and M10 cells was studied with respect to their modes of cell death, apoptosis and necrosis. MOLT-4N1 cells showed radiosensitivity similar to that of M10 cells, a radiosensitive mutant of L5178Y, as determined by the colony formation assay. Analysis of cell size demonstrated that MOLT-4N1 cells increased in size at an early stage after irradiation and then decreased to a size smaller than that of control cells, whereas the size of irradiated M10 cells increased continuously. Apoptosis detected by morphological changes and DNA ladder formation (the cleavage of DNA into oligonucleosomal fragments) occurred in X-irradiated MOLT-4N1 cells but not in M10 cells. Pulsed-field gel electrophoresis showed that the ladder formation involved an intermediate-sized DNA (about 20 kbp). Most of the DNA was detected at the origin in both methods of electrophoresis in the case of M10 cells, though a trace amount of ladder formation was observed. Heat treatment of M10 cells induced apoptosis within 30 min after treatment, in contrast to MOLT-4N1 cells. The results suggest that apoptosis and necrosis are induced by X rays in a manner which is dependent on the cell line irrespective of the capability of the cells to develop apoptosis. DNA fragmentation was the earliest change observed in the development of apoptosis. 27 refs., 8 figs., 1 tab.

  16. Cilostazol suppresses angiotensin II-induced apoptosis in endothelial cells

    PubMed Central

    SHI, MIAO-QIAN; SU, FEI-FEI; XU, XUAN; LIU, XIONG-TAO; WANG, HONG-TAO; ZHANG, WEI; LI, XUE; LIAN, CHENG; ZHENG, QIANG-SUN; FENG, ZHI-CHUN

    2016-01-01

    Patients with essential hypertension undergo endothelial dysfunction, particularly in the conduit arteries. Cilostazol, a type III phosphodiesterase inhibitor, serves a role in the inhibition of platelet aggregation and it is widely used in the treatment of peripheral vascular diseases. Previous studies have suggested that cilostazol suppresses endothelial dysfunction; however, it remains unknown whether cilostazol protects the endothelial function in essential hypertension. The aim of the present study was to investigate whether, and how, cilostazol suppresses angiotensin II (angII)-induced endothelial dysfunction. Human umbilical vein endothelial cells (HUVECs) and Sprague Dawley rats were exposed to angII and treated with cilostazol. Endothelial cell apoptosis and function, nitric oxide and superoxide production, phosphorylation (p) of Akt, and caspase-3 protein expression levels were investigated. AngII exposure resulted in the apoptosis of endothelial cells in vitro and in vivo. In vitro, cilostazol significantly suppressed the angII-induced apoptosis of HUVECs; however, this effect was reduced in the presence of LY294002, a phosphoinositide 3 kinase (PI3K) inhibitor. Furthermore, cilostazol suppressed the angII-induced p-Akt downregulation and cleaved caspase-3 upregulation. These effects were also alleviated by LY294002. In vivo, cilostazol suppressed the angII-induced endothelial cell apoptosis and dysfunction. Cilostazol was also demonstrated to partially reduced the angII-induced increase in superoxide production. The results of the present study suggested that cilostazol suppresses endothelial apoptosis and dysfunction by modulating the PI3K/Akt pathway. PMID:26862035

  17. Csk regulates angiotensin II-induced podocyte apoptosis.

    PubMed

    Zhang, Lu; Ren, Zhilong; Yang, Qian; Ding, Guohua

    2016-07-01

    Increasing data have shown that angiotensin II (Ang II) perpetuates podocyte injury and promotes progression to end-stage kidney disease. The mechanism underlying Ang II-induced podocyte apoptosis has not been established. C-terminal Src kinase (Csk) is a cytoplasmic kinase that interacts with scaffolding proteins involved in cell growth, adhesion, and polarization, and the role of Csk in regulating cellular apoptosis has gradually attracted attention. This study evaluates the role of Csk in Ang II-induced podocyte apoptosis. In vivo, Wistar rats were randomly subjected to a normal saline or Ang II infusion. In vitro, we exposed differentiated mouse podocytes to Ang II. Ang II increased Csk expression and induced podocyte apoptosis, stimulated Csk translocation and binding to Caveolin-1, and stimulated decreased Fyn pY416, increased Fyn pY529, and nephrin dephosphorylation. Csk knockdown prevented Ang II-induced podocyte apoptosis, reduced Fyn kinase inactivation, and increased the interaction between nephrin and the activated form of Fyn, accompanied by a reduced interaction between Csk and Caveolin-1. These findings indicate that Ang II induces podocyte injury via a Csk-dependent pathway. PMID:27225249

  18. Role of Metabolism in Arsenic-Induced Toxicity: Identification and Quantification of Arsenic Metabolites in Tissues and Excreta

    EPA Science Inventory

    Arsenic is a known toxicant and carcinogen. Methylation of inorganic arsenic was once thought to be a detoxification mechanism because of the rapid excretion and relatively lower toxicity of the pentavalent organic arsenical metabolites. Advances in analytical chemistry have al...

  19. Chronic Arsenic Exposure-Induced Oxidative Stress is Mediated by Decreased Mitochondrial Biogenesis in Rat Liver.

    PubMed

    Prakash, Chandra; Kumar, Vijay

    2016-09-01

    The present study was executed to study the effect of chronic arsenic exposure on generation of mitochondrial oxidative stress and biogenesis in rat liver. Chronic sodium arsenite treatment (25 ppm for 12 weeks) decreased mitochondrial complexes activity in rat liver. There was a decrease in mitochondrial superoxide dismutase (MnSOD) activity in arsenic-treated rats that might be responsible for increased protein and lipid oxidation as observed in our study. The messenger RNA (mRNA) expression of mitochondrial and nuclear-encoded subunits of complexes I (ND1 and ND2) and IV (COX I and COX IV) was downregulated in arsenic-treated rats only. The protein and mRNA expression of MnSOD was reduced suggesting increased mitochondrial oxidative damage after arsenic treatment. There was activation of Bax and caspase-3 followed by release of cytochrome c from mitochondria suggesting induction of apoptotic pathway under oxidative stress. The entire phenomenon was associated with decrease in mitochondrial biogenesis as evident by decreased protein and mRNA expression of nuclear respiratory factor 1 (NRF-1), nuclear respiratory factor 2 (NRF-2), peroxisome proliferator activator receptor gamma-coactivator 1α (PGC-1α), and mitochondrial transcription factor A (Tfam) in arsenic-treated rat liver. The results of the present study indicate that arsenic-induced mitochondrial oxidative stress is associated with decreased mitochondrial biogenesis in rat liver that may present one of the mechanisms for arsenic-induced hepatotoxicity. PMID:26767369

  20. Neem oil limonoids induces p53-independent apoptosis and autophagy.

    PubMed

    Srivastava, Pragya; Yadav, Neelu; Lella, Ravi; Schneider, Andrea; Jones, Anthony; Marlowe, Timothy; Lovett, Gabrielle; O'Loughlin, Kieran; Minderman, Hans; Gogada, Raghu; Chandra, Dhyan

    2012-11-01

    Azadirachta indica, commonly known as neem, has a wide range of medicinal properties. Neem extracts and its purified products have been examined for induction of apoptosis in multiple cancer cell types; however, its underlying mechanisms remain undefined. We show that neem oil (i.e., neem), which contains majority of neem limonoids including azadirachtin, induced apoptotic and autophagic cell death. Gene silencing demonstrated that caspase cascade was initiated by the activation of caspase-9, whereas caspase-8 was also activated late during neem-induced apoptosis. Pretreatment of cancer cells with pan caspase inhibitor, z-VAD inhibited activities of both initiator caspases (e.g., caspase-8 and -9) and executioner caspase-3. Neem induced the release of cytochrome c and apoptosis-inducing factor (AIF) from mitochondria, suggesting the involvement of both caspase-dependent and AIF-mediated apoptosis. p21 deficiency caused an increase in caspase activities at lower doses of neem, whereas p53 deficiency did not modulate neem-induced caspase activation. Additionally, neem treatment resulted in the accumulation of LC3-II in cancer cells, suggesting the involvement of autophagy in neem-induced cancer cell death. Low doses of autophagy inhibitors (i.e., 3-methyladenine and LY294002) did not prevent accumulation of neem-induced LC3-II in cancer cells. Silencing of ATG5 or Beclin-1 further enhanced neem-induced cell death. Phosphoinositide 3-kinase (PI3K) or autophagy inhibitors increased neem-induced caspase-3 activation and inhibition of caspases enhanced neem-induced autophagy. Together, for the first time, we demonstrate that neem induces caspase-dependent and AIF-mediated apoptosis, and autophagy in cancer cells. PMID:22915764

  1. Arsenic trioxide promotes mitochondrial DNA mutation and cell apoptosis in primary APL cells and NB4 cell line.

    PubMed

    Meng, Ran; Zhou, Jin; Sui, Meng; Li, ZhiYong; Feng, GuoSheng; Yang, BaoFeng

    2010-01-01

    This study aimed to investigate the effects of arsenic trioxide (As(2)O(3)) on the mitochondrial DNA (mtDNA) of acute promyelocytic leukemia (APL) cells. The NB4 cell line was treated with 2.0 micromol/L As(2)O(3) in vitro, and the primary APL cells were treated with 2.0 micromol/L As(2)O(3) in vitro and 0.16 mg kg(-1) d(-1) As(2)O(3) in vivo. The mitochondrial DNA of all the cells above was amplified by PCR, directly sequenced and analyzed by Sequence Navigatore and Factura software. The apoptosis rates were assayed by flow cytometry. Mitochondrial DNA mutation in the D-loop region was found in NB4 and APL cells before As(2)O(3) use, but the mutation spots were remarkably increased after As(2)O(3) treatment, which was positively correlated to the rates of cellular apoptosis, the correlation coefficient: r (NB4-As2O3)=0.973818, and r (APL-As2O3)=0.934703. The mutation types include transition, transversion, codon insertion or deletion, and the mutation spots in all samples were not constant and regular. It is revealed that As(2)O(3) aggravates mtDNA mutation in the D-loop region of acute promyelocytic leukemia cells both in vitro and in vivo. Mitochondrial DNA might be one of the targets of As(2)O(3) in APL treatment. PMID:20596959

  2. Denbinobin induces apoptosis by apoptosis-inducing factor releasing and DNA damage in human colorectal cancer HCT-116 cells.

    PubMed

    Chen, Tzu-Hsuan; Pan, Shiow-Lin; Guh, Jih-Hwa; Chen, Chien-Chih; Huang, Yao-Ting; Pai, Hui-Chen; Teng, Che-Ming

    2008-11-01

    Denbinobin is a phenanthraquinone derivative present in the stems of Ephemerantha lonchophylla. We showed that denbinobin induces apoptosis in human colorectal cancer cells (HCT-116) in a concentration-dependent manner. The addition of a pan-caspase inhibitor (zVAD-fmk) did not suppress the denbinobin-induced apoptotic effect, and denbinobin-induced apoptosis was not accompanied by processing of procaspase-3, -6, -7, -9, and -8. However, denbinobin triggered the translocation of the apoptosis-inducing factor (AIF) from the mitochondria into the nucleus. Small interfering RNA targeting of AIF effectively protected HCT-116 cells against denbinobin-induced apoptosis. Denbinobin treatment also caused DNA damage, activation of the p53 tumor suppressor gene, and upregulation of numerous downstream effectors (p21WAF1/CIP1, Bax, PUMA, and NOXA). A HCT-116 xenograft model demonstrated the in vivo efficacy and low toxicity of denbinobin. Taken together, our findings suggest that denbinobin induces apoptosis of human colorectal cancer HCT-116 cells via DNA damage and an AIF-mediated pathway. These results indicate that denbinobin has potential as a novel anticancer agent. PMID:18607570

  3. Calpain Inhibitor PD150606 Attenuates Glutamate Induced Spiral Ganglion Neuron Apoptosis through Apoptosis Inducing Factor Pathway In Vitro

    PubMed Central

    Song, Yong-Li; Chen, Xiao-Dong; Mi, Wen-Juan; Wang, Jian; Lin, Ying; Chen, Fu-Quan; Qiu, Jian-Hua

    2015-01-01

    Objective This research aimed to investigate whether glutamate induced spiral ganglion neurons (SGNs) apoptosis through apoptosis inducing factor (AIF) pathway. And verify whether PD150606, a calpain inhibitor could prevent apoptosis by inhibiting cleaving and releasing AIF in mitochondrion. Methods SGNs of postnatal days 0-3 were harvested and cultured in dishes. 20 mM Glu, the caspase inhibitor Z-VAD-FMK and calpain inhibitor PD150606 were added into cultured dishes separately. We used optical microscope and immunofluoresence staining to observe cell morphology and AIF distribution, RT-PCR and Westernblot to analyse AIF and calpain expression in SGNs. TUNEL assay was used to test cell apoptosis. Results Cell morphology and nuclear translocation of AIF were altered in SGNs by 20 mM Glu treated in vitro. The axon of SGN shortened, more apoptosis SGN were observed and the expression of AIF and calpain were up-regulated in Glu-treated group than the normal one (P<0.05). The same experiments were conducted in 20 mM+PD150606 treated group and 20 mM+Z-VAD-FMK group. Obviously AIF were located from cytoplasm to the nuclear and the expressions of AIF and calpain were down-regulated by PD150606 (P<0.05). Positive cells in TUNEL staining decreased after PD150606 treating. However, Z-VAD-FMK had no influence on AIF, calpain expression or cell apoptosis. Conclusion The AIF-related apoptosis pathway is involved in the process of Glu-induced SGN injury. Furthermore, the inhibition of calpain can prevent AIF from releasing the nuclear or inducing SGN apoptosis. PMID:25874633

  4. Therapeutic efficacy of silymarin and naringenin in reducing arsenic-induced hepatic damage in young rats.

    PubMed

    Jain, Anshu; Yadav, Abhishek; Bozhkov, A I; Padalko, V I; Flora, S J S

    2011-05-01

    We investigated the effects of silymarin and naringenin in counteracting arsenic-induced hepatic oxidative stress post exposure. Male wistar rats were chronically exposed to sodium arsenite for eight months followed by oral treatment with silymarin and naringenin (50 mg/kg each) for 15 consecutive days to evaluate hepatic damage and antioxidant potential. Our results demonstrate a significant decrease in hepatic GSH levels, SOD and catalase activities and an increase in GST and TBARS levels after arsenic administration. Silymarin or naringenin administration increased GSH levels and was beneficial in the recovery of altered SOD and catalase activity besides significantly reducing blood and tissue arsenic concentration. Our results point to the antioxidant potential of these flavonoids, which might be of benefit in the clinical recovery of subject exposed to arsenic. These flavonoids can be incorporated into the diet or co-supplemented during chelation treatment, and thus may afford a protective effect against arsenite-induced cytotoxicity. PMID:20719385

  5. Rabies virus infects mouse and human lymphocytes and induces apoptosis.

    PubMed Central

    Thoulouze, M I; Lafage, M; Montano-Hirose, J A; Lafon, M

    1997-01-01

    Attenuated and highly neurovirulent rabies virus strains have distinct cellular tropisms. Highly neurovirulent strains such as the challenge virus standard (CVS) are highly neurotropic, whereas the attenuated strain ERA also infects nonneuronal cells. We report that both rabies virus strains infect activated murine lymphocytes and the human lymphoblastoid Jurkat T-cell line in vitro. The lymphocytes are more permissive to the attenuated ERA rabies virus strain than to the CVS strain in both cases. We also report that in contrast to that of the CVS strain, ERA viral replication induces apoptosis of infected Jurkat T cells, and cell death is concomitant with viral glycoprotein expression, suggesting that this protein has a role in the induction of apoptosis. Our data indicate that (i) rabies virus infects lymphocytes, (ii) lymphocyte infection with the attenuated rabies virus strain causes apoptosis, and (iii) apoptosis does not hinder rabies virus production. In contrast to CVS, ERA rabies virus and other attenuated rabies virus vaccines stimulate a strong immune response and are efficient live vaccines. The paradoxical finding that a rabies virus triggers a strong immune response despite the fact that it infects lymphocytes and induces apoptosis is discussed in terms of the function of apoptosis in the immune response. PMID:9311815

  6. The retinoblastoma protein induces apoptosis directly at the mitochondria

    PubMed Central

    Hilgendorf, Keren I.; Leshchiner, Elizaveta S.; Nedelcu, Simona; Maynard, Mindy A.; Calo, Eliezer; Ianari, Alessandra; Walensky, Loren D.; Lees, Jacqueline A.

    2013-01-01

    The retinoblastoma protein gene RB-1 is mutated in one-third of human tumors. Its protein product, pRB (retinoblastoma protein), functions as a transcriptional coregulator in many fundamental cellular processes. Here, we report a nonnuclear role for pRB in apoptosis induction via pRB's direct participation in mitochondrial apoptosis. We uncovered this activity by finding that pRB potentiated TNFα-induced apoptosis even when translation was blocked. This proapoptotic function was highly BAX-dependent, suggesting a role in mitochondrial apoptosis, and accordingly, a fraction of endogenous pRB constitutively associated with mitochondria. Remarkably, we found that recombinant pRB was sufficient to trigger the BAX-dependent permeabilization of mitochondria or liposomes in vitro. Moreover, pRB interacted with BAX in vivo and could directly bind and conformationally activate BAX in vitro. Finally, by targeting pRB specifically to mitochondria, we generated a mutant that lacked pRB's classic nuclear roles. This mito-tagged pRB retained the ability to promote apoptosis in response to TNFα and also additional apoptotic stimuli. Most importantly, induced expression of mito-tagged pRB in Rb−/−;p53−/− tumors was sufficient to block further tumor development. Together, these data establish a nontranscriptional role for pRB in direct activation of BAX and mitochondrial apoptosis in response to diverse stimuli, which is profoundly tumor-suppressive. PMID:23618872

  7. 6-Gingerol induces autophagy to protect HUVECs survival from apoptosis.

    PubMed

    Wang, Shaopeng; Sun, Xiance; Jiang, Liping; Liu, Xiaofang; Chen, Min; Yao, Xiaofeng; Sun, Qinghua; Yang, Guang

    2016-08-25

    6-Gingerol, the major pharmacologically-active component of ginger, has the potential to prevent heart disease. However, the mechanisms are not well understood. In this study, the protective effect of 6-gingerol against hydrogen peroxide-induced apoptosis in human umbilical vein endothelial cells (HUVECs) was investigated. Apoptosis was detected by Hoechst 33342 and Flow cytometry analysis. To further elucidate the crosstalk between apoptosis and autophagy, we tested the expression of autophagy related proteins, LC3B, Bcl-2, Beclin1, AKT, p-AKT, mechanistic target of rapamycin (mTOR), and p-mTOR. Furthermore, mitochondrial membrane potential and the intracellular generation of reactive oxygen species (ROS) were also investigated. Our data revealed that 6-gingerol significantly reduced apoptosis by inducing autophagy. It has been demonstrated that 6-gingerol suppressed the phosphatidylinositol 3-kinase (PI3K)/AKT/mTOR signaling pathway, increased the expression of Beclin1 to promote autophagy, and increased Bcl-2 expression to inhibit apoptosis. In addition, the damage of mitochondrial was protected, and ROS level was decreased by 6-gingerol. These firmly indicate 6-gingerol has a strong protective ability against the apoptosis caused by oxidative stress in HUVECs, and the mechanism may relate to the induction of autophagy. Our data suggest 6-gingerol may be beneficial in the prevention of atherosclerosis. PMID:27451028

  8. Autophagy Regulates Colistin-Induced Apoptosis in PC-12 Cells

    PubMed Central

    Zhang, Ling; Zhao, Yonghao; Ding, Wenjian; Jiang, Guozheng; Lu, Ziyin; Li, Li; Wang, Jinli

    2015-01-01

    Colistin is a cyclic cationic polypeptide antibiotic with activity against multidrug-resistant Gram-negative bacteria. Our recent study demonstrated that colistin induces apoptosis in primary chick cortex neurons and PC-12 cells. Although apoptosis and autophagy have different impacts on cell fate, there is a complex interaction between them. Autophagy plays an important role as a homeostasis regulator by removing excessive or unnecessary proteins and damaged organelles. The aim of the present study was to investigate the modulation of autophagy and apoptosis regulation in PC-12 cells in response to colistin treatment. PC-12 cells were exposed to colistin (125 to 250 μg/ml), and autophagy was detected by visualization of monodansylcadaverine (MDC)-labeled vacuoles, LC3 (microtubule-associated protein 1 light chain 3) immunofluorescence microscopic examination, and Western blotting. Apoptosis was measured by flow cytometry, Hoechst 33258 staining, and Western blotting. Autophagosomes were observed after treatment with colistin for 12 h, and the levels of LC3-II gene expression were determined; observation and protein levels both indicated that colistin induced a high level of autophagy. Colistin treatment also led to apoptosis in PC-12 cells, and the level of caspase-3 expression increased over the 24-h period. Pretreatment of cells with 3-methyladenine (3-MA) increased colistin toxicity in PC-12 cells remarkably. However, rapamycin treatment significantly increased the expression levels of LC3-II and beclin 1 and decreased the rate of apoptosis of PC-12 cells. Our results demonstrate that colistin induced autophagy and apoptosis in PC-12 cells and that the latter was affected by the regulation of autophagy. It is very likely that autophagy plays a protective role in the reduction of colistin-induced cytotoxicity in neurons. PMID:25645826

  9. Hydrogen peroxide induces apoptosis via a mitochondrial pathway in chondrocytes

    NASA Astrophysics Data System (ADS)

    Zhuang, Cai-ping; Liang, Qian; Wang, Xiao-ping; Chen, Tong-sheng

    2012-03-01

    The degenerative joint disease such as osteoarthritis (OA) is closely associated with the death of chondrocytes in apoptosis fashion. Hydrogen peroxide (H2O2), higher expression following acute damage in OA patients, has been shown to be up-regulated during apoptosis in a bulk of experimental models. This study was aimed to explore the mechanism of H2O2-induced rabbit chondrocytes apoptosis. Articular cartilage was biopsied from the joints of 6 weeks old New Zealand rabbits. Cell Counting Kit (CCK-8) assay was used to assess the inhibitory effect of H2O2 on cell viability. H2O2 treatment induced a remarkable reduction of cell viability. We used flow cytometry to assess the form of cell death with Annexin-V/PI double staining, and found that H2O2 treatment induced apoptosis in a dose-and time-dependent manner. Exposure of chondrocytes to 1.5 mM of H2O2 for 2 h induced a burst apoptosis that can be alleviated by N-acetyl cysteine (NAC) pretreatment, an anti-oxidant amino-acid derivative. Loss of mitochondria membrane potential (▵Ψm) was evaluated using confocal microscopy imaging and flow cytometry (FCM). H2O2 treatment induced a marked reduction of ▵Ψm, and the abrupt disappearance of ▵Ψm occurred within 5 minutes. These results indicate that H2O2 induces a rapid apoptosis via a mitochondrial pathway in rabbit chondrocytes.

  10. Heavy Metals and Metalloids as Autophagy Inducing Agents: Focus on Cadmium and Arsenic

    PubMed Central

    Chiarelli, Roberto; Roccheri, Maria Carmela

    2012-01-01

    In recent years, research on the autophagic process has greatly increased, invading the fields of biology and medicine. Several markers of the autophagic process have been discovered and various strategies have been reported studying this molecular process in different biological systems in both physiological and stress conditions. Furthermore, mechanisms of metalloid- or heavy metal-induced toxicity continue to be of interest given the ubiquitous nature and distribution of these contaminants in the environment where they often play the role of pollutants of numerous organisms. The aim of this review is a critical analysis and correlation of knowledge of autophagic mechanisms studied under stress for the most common arsenic (As) and cadmium (Cd) compounds. In this review we report data obtained in different experimental models for each compound, highlighting similarities and/or differences in the activation of autophagic processes. A more detailed discussion will concern the activation of autophagy in Cd-exposed sea urchin embryo since it is a suitable model system that is very sensitive to environmental stress, and Cd is one of the most studied heavy metal inductors of stress and modulator of different factors such as: protein kinase and phosphatase, caspases, mitochondria, heat shock proteins, metallothioneins, transcription factors, reactive oxygen species, apoptosis and autophagy. PMID:24710492

  11. Morphine Attenuated the Cytotoxicity Induced by Arsenic Trioxide in H9c2 Cardiomyocytes.

    PubMed

    Amini-Khoei, Hossein; Hosseini, Mir-Jamal; Momeny, Majid; Rahimi-Balaei, Maryam; Amiri, Shayan; Haj-Mirzaian, Arya; Khedri, Mostafa; Jahanabadi, Samane; Mohammadi-Asl, Ali; Mehr, Shahram Ejtemaie; Dehpour, Ahmad Reza

    2016-09-01

    Arsenic trioxide (ATO) is an efficient drug for the treatment of the patients with acute promyelocytic leukemia (APL). Inhibition of proliferation as well as apoptosis, attenuation of migration, and induction of differentiation in tumor cells are the main mechanisms through which ATO acts against APL. Despite advantages of ATO in treatment of some malignancies, certain harmful side effects, such as cardiotoxicity, have been reported. It has been well documented that morphine has antioxidant, anti-apoptotic, and cytoprotective properties and is able to attenuate cytotoxicity. Therefore, in this study, we aimed to investigate the protective effects of morphine against ATO toxicity in H9c2 myocytes using multi-parametric assay including thiazolyl blue tetrazolium bromide (MTT) assay, reactive oxygen species (ROS) generation, caspase 3 activity, nuclear factor kappa B (NF-κB) phosphorylation assay, and expression of apoptotic markers. Our results showed that morphine (1 μM) attenuated cytotoxicity induced by ATO in H9c2 cells. Results of this study suggest that morphine may have protective properties in management of cardiac toxicity in patients who receive ATO as an anti-cancer treatment. PMID:26815588

  12. Iron dysregulation combined with aging prevents sepsis-induced apoptosis

    PubMed Central

    Javadi, Pardis; Buchman, Timothy G.; Stromberg, Paul E.; Turnbull, Isaiah R.; Vyas, Dinesh; Hotchkiss, Richard S.; Karl, Irene E.; Coopersmith, Craig M.

    2005-01-01

    Background Sepsis, iron loading and aging cause independent increases in gut epithelial and splenic apoptosis. It is unknown how their combination will affect apoptosis and systemic cytokine levels. Methods Hfe−/− mice (a murine homolog of hemochromatosis) abnormally accumulate iron in their tissues. Aged (24–26 months) or mature (16–18 months) Hfe−/− mice and wild type (WT) littermates were subjected to cecal ligation and puncture (CLP) or sham laparotomy. Intestine, spleen, and blood were harvested 24 hours later and assessed for apoptosis and cytokine levels. Results Gut epithelial and splenic apoptosis were low in both aged septic and sham Hfe−/− mice, regardless of the amount of iron in their diet. Mature septic WT mice had increased apoptosis compared to age-matched sham WT mice. Mature septic Hfe−/− mice had similar levels of intestinal cell death to age-matched septic WT mice but higher levels of splenic apoptosis. Apoptosis was significantly lower in septic aged Hfe−/− mice than septic mature Hfe−/− animals. Interleukin-6 was elevated in septic aged Hfe−/− mice compared to sham mice. Conclusions Although sepsis, chronic iron dysregulation, and aging each increase gut and splenic apoptosis, their combination yields cell death levels similar to sham animals despite the fact that aged Hfe−/− mice are able to mount an inflammatory response following CLP and mature Hfe−/− mice have elevated sepsis-induced apoptosis. Combining sepsis with two risk factors that ordinarily increase cell death and increase mortality in CLP yields an apoptotic response that could not have been predicted based upon each element in isolation. PMID:15921699

  13. MiADMSA reverses impaired mitochondrial energy metabolism and neuronal apoptotic cell death after arsenic exposure in rats

    SciTech Connect

    Dwivedi, Nidhi; Mehta, Ashish; Yadav, Abhishek; Binukumar, B.K.; Gill, Kiran Dip; Flora, Swaran J.S.

    2011-11-15

    Arsenicosis, due to contaminated drinking water, is a serious health hazard in terms of morbidity and mortality. Arsenic induced free radicals generated are known to cause cellular apoptosis through mitochondrial driven pathway. In the present study, we investigated the effect of arsenic interactions with various complexes of the electron transport chain and attempted to evaluate if there was any complex preference of arsenic that could trigger apoptosis. We also evaluated if chelation with monoisoamyl dimercaptosuccinic acid (MiADMSA) could reverse these detrimental effects. Our results indicate that arsenic exposure induced free radical generation in rat neuronal cells, which diminished mitochondrial potential and enzyme activities of all the complexes of the electron transport chain. Moreover, these complexes showed differential responses towards arsenic. These early events along with diminished ATP levels could be co-related with the later events of cytosolic migration of cytochrome c, altered bax/bcl{sub 2} ratio, and increased caspase 3 activity. Although MiADMSA could reverse most of these arsenic-induced altered variables to various extents, DNA damage remained unaffected. Our study for the first time demonstrates the differential effect of arsenic on the complexes leading to deficits in bioenergetics leading to apoptosis in rat brain. However, more in depth studies are warranted for better understanding of arsenic interactions with the mitochondria. -- Research highlights: Black-Right-Pointing-Pointer Arsenic impairs mitochondrial energy metabolism leading to neuronal apoptosis. Black-Right-Pointing-Pointer Arsenic differentially affects mitochondrial complexes, I - III and IV being more sensitive than complex II. Black-Right-Pointing-Pointer Arsenic-induced apoptosis initiates through ROS generation or impaired [Ca{sup 2+}]i homeostasis. Black-Right-Pointing-Pointer MiADMSA reverses arsenic toxicity via intracellular arsenic- chelation, antioxidant

  14. An increase of granulosa cell apoptosis mediates aqueous neem (Azadirachta indica) leaf extract-induced oocyte apoptosis in rat

    PubMed Central

    Tripathi, Anima; Shrivastav, Tulsidas G; Chaube, Shail K

    2013-01-01

    Objective: Neem plant (Azadirachta indica) has been extensively used in Ayurvedic system of medicine for female fertility regulation for a long time, but its mechanism of action remains poorly understood. Hence, the present study was aimed to determine whether an increase of granulosa cell apoptosis is associated with aqueous neem leaf extract (NLE)-induced oocyte apoptosis. Materials and Methods: Sexually immature female rats of 20 days old were fed NLE (50 mg/day) for 10 days and then subjected to superovulation induction protocol. The morphological changes in cumulus oocyte complexes (COCs), rate of oocyte apoptosis, hydrogen peroxide (H2O2), total nitrite, and cytochrome c concentrations, inducible nitric oxide synthase (iNOS), cytochrome c, p53, Bcl2 and Bax expressions, deoxyribonucleic acid (DNA) fragmentation, and estradiol 17β level in granulosa cells collected from preovulatory COCs were analyzed. Results: Aqueous NLE increased H2O2 concentration and decreased catalase activity, increased iNOS expression and total nitrite concentration, increased p53, Bax, and p53 expressions but decreased Bcl2 expression, increased cytochrome c concentration and induced DNA fragmentation in granulosa cells. An increased granulosa cell apoptosis resulted in reduced estradiol 17β concentration and induced apoptosis in ovulated oocytes. Conclusion: We conclude that aqueous NLE-induced granulosa cell apoptosis through the mitochondria-mediated pathway, reduced estradiol 17β concentration and induced apoptosis in ovulated oocytes. Thus, granulosa cell apoptosis mediates NLE-induced oocyte apoptosis during female fertility regulation in rat. PMID:23776837

  15. Cystamine induces AIF-mediated apoptosis through glutathione depletion.

    PubMed

    Cho, Sung-Yup; Lee, Jin-Haeng; Ju, Mi-kyeong; Jeong, Eui Man; Kim, Hyo-Jun; Lim, Jisun; Lee, Seungun; Cho, Nam-Hyuk; Park, Hyun Ho; Choi, Kihang; Jeon, Ju-Hong; Kim, In-Gyu

    2015-03-01

    Cystamine and its reduced form cysteamine showed protective effects in various models of neurodegenerative disease, including Huntington's disease and Parkinson's disease. Other lines of evidence demonstrated the cytotoxic effect of cysteamine on duodenal mucosa leading to ulcer development. However, the mechanism for cystamine cytotoxicity remains poorly understood. Here, we report a new pathway in which cystamine induces apoptosis by targeting apoptosis-inducing factor (AIF). By screening of various cell lines, we observed that cystamine and cysteamine induce cell death in a cell type-specific manner. Comparison between cystamine-sensitive and cystamine-resistant cell lines revealed that cystamine cytotoxicity is not associated with unfolded protein response, reactive oxygen species generation and transglutaminase or caspase activity; rather, it is associated with the ability of cystamine to trigger AIF nuclear translocation. In cystamine-sensitive cells, cystamine suppresses the levels of intracellular glutathione by inhibiting γ-glutamylcysteine synthetase expression that triggers AIF translocation. Conversely, glutathione supplementation completely prevents cystamine-induced AIF translocation and apoptosis. In rats, cysteamine administration induces glutathione depletion and AIF translocation leading to apoptosis of duodenal epithelium. These results indicate that AIF translocation through glutathione depletion is the molecular mechanism of cystamine toxicity, and provide important implications for cystamine in the neurodegenerative disease therapeutics as well as in the regulation of AIF-mediated cell death. PMID:25549939

  16. (+)-Catechin protects dermal fibroblasts against oxidative stress-induced apoptosis

    PubMed Central

    2014-01-01

    Background Oxidative stress has been suggested as a mechanism underlying skin aging, as it triggers apoptosis in various cell types, including fibroblasts, which play important roles in the preservation of healthy, youthful skin. Catechins, which are antioxidants contained in green tea, exert various actions such as anti-inflammatory, anti-bacterial, and anti-cancer actions. In this study, we investigated the effect of (+)-catechin on apoptosis induced by oxidative stress in fibroblasts. Methods Fibroblasts (NIH3T3) under oxidative stress induced by hydrogen peroxide (0.1 mM) were treated with either vehicle or (+)-catechin (0–100 μM). The effect of (+)-catechin on cell viability, apoptosis, phosphorylation of c-Jun terminal kinases (JNK) and p38, and activation of caspase-3 in fibroblasts under oxidative stress were evaluated. Results Hydrogen peroxide induced apoptotic cell death in fibroblasts, accompanied by induction of phosphorylation of JNK and p38 and activation of caspase-3. Pretreatment of the fibroblasts with (+)-catechin inhibited hydrogen peroxide-induced apoptosis and reduced phosphorylation of JNK and p38 and activation of caspase-3. Conclusion (+)-Catechin protects against oxidative stress-induced cell death in fibroblasts, possibly by inhibiting phosphorylation of p38 and JNK. These results suggest that (+)-catechin has potential as a therapeutic agent for the prevention of skin aging. PMID:24712558

  17. Lysophosphatidic acid induces necrosis and apoptosis in hippocampal neurons.

    PubMed

    Holtsberg, F W; Steiner, M R; Keller, J N; Mark, R J; Mattson, M P; Steiner, S M

    1998-01-01

    A diverse body of evidence indicates a role for the lipid biomediator lysophosphatidic acid (LPA) in the CNS. This study identifies and characterizes the induction of neuronal death by LPA. Treatment of cultured hippocampal neurons from embryonic rat brains with 50 microM LPA resulted in neuronal necrosis, as determined morphologically and by the release of lactate dehydrogenase. A concentration of LPA as low as 10 microM led to the release of lactate dehydrogenase. In contrast, treatment of neurons with 0.1 or 1.0 microM LPA resulted in apoptosis, as determined by chromatin condensation. In addition, neuronal death induced by 1 microM LPA was characterized as apoptotic on the basis of terminal dUTP nick end-labeling (TUNEL) staining, externalization of phosphatidylserine, and protection against chromatin condensation, TUNEL staining, and phosphatidylserine externalization by treatment with N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl ketone, a broad-spectrum inhibitor of caspases, i.e., members of the interleukin-1beta converting enzyme family. Studies with antagonists of ionotropic glutamate receptors did not indicate a significant role for these receptors in apoptosis induced by 1 microM LPA. LPA (1 microM) also induced a decrease in mitochondrial membrane potential. Moreover, pretreatment of neurons with cyclosporin A protected against the LPA-induced decrease in mitochondrial membrane potential and neuronal apoptosis. Thus, LPA, at pathophysiological levels, can induce neuronal apoptosis and could thereby participate in neurodegenerative disorders. PMID:9422348

  18. Hydrogen peroxide-induced apoptosis in human gingival fibroblasts.

    PubMed

    Gutiérrez-Venegas, Gloria; Guadarrama-Solís, Adriana; Muñoz-Seca, Carmen; Arreguín-Cano, Juan Antonio

    2015-01-01

    In the process of bleaching vital, discolored teeth, low concentrations of hydrogen peroxide (H2O2) are effective alternatives to heat-activated 30% H2O2. However, interest has been expressed in the assessment of pathological effects of long-term exposure to bleaching agents such as irritation and ulceration of the gingival or other soft tissues. The aim of the present study was to determine the effect of hydrogen peroxide on apoptosis in human gingival fibroblasts (HGF). Cytochrome c, Bcl-2, Bax, Bid and caspase-3 protein expression were detected by Western blotting. HGF cell apoptosis induced by H2O2 was both dose and time dependent. The addition of H2O2 resulted in the release of cytochrome c to the cytosol, and an increase of Caspase-3 cleavage. Data suggest that oxidative stress-induced apoptosis in HGF is intrinsic pathway involved the release of apoptotic signal from mitochondria. PMID:26884825

  19. Hydrogen peroxide-induced apoptosis in human gingival fibroblasts

    PubMed Central

    Gutiérrez-Venegas, Gloria; Guadarrama-Solís, Adriana; Muñoz-Seca, Carmen; Arreguín-Cano, Juan Antonio

    2015-01-01

    In the process of bleaching vital, discolored teeth, low concentrations of hydrogen peroxide (H2O2) are effective alternatives to heat-activated 30% H2O2. However, interest has been expressed in the assessment of pathological effects of long-term exposure to bleaching agents such as irritation and ulceration of the gingival or other soft tissues. The aim of the present study was to determine the effect of hydrogen peroxide on apoptosis in human gingival fibroblasts (HGF). Cytochrome c, Bcl-2, Bax, Bid and caspase-3 protein expression were detected by Western blotting. HGF cell apoptosis induced by H2O2 was both dose and time dependent. The addition of H2O2 resulted in the release of cytochrome c to the cytosol, and an increase of Caspase-3 cleavage. Data suggest that oxidative stress-induced apoptosis in HGF is intrinsic pathway involved the release of apoptotic signal from mitochondria. PMID:26884825

  20. Protective effects of Moringa oleifera Lam. leaves against arsenic-induced toxicity in mice

    PubMed Central

    Sheikh, Afzal; Yeasmin, Fouzia; Agarwal, Smita; Rahman, Mashiur; Islam, Khairul; Hossain, Ekhtear; Hossain, Shakhawoat; Karim, Md Rezaul; Nikkon, Farjana; Saud, Zahangir Alam; Hossain, Khaled

    2014-01-01

    Objective To evaluate the protective role of leaves of Moringa oleifera (M. oleifera) Lam. against arsenic-induced toxicity in mice. Methods Swiss albino male mice were divided into four groups. The first group was used as non-treated control group while, the second, third, and fourth groups were treated with M. oleifera leaves (50 mg/kg body weight per day), sodium arsenite (10 mg/kg body weight per day) and sodium arsenite plus M. oleifera leaves, respectively. Serum indices related to cardiac, liver and renal functions were analyzed to evaluate the protective effect of Moringa leaves on arsenic-induced effects in mice. Results It revealed that food supplementation of M. oleifera leaves abrogated the arsenic-induced elevation of triglyceride, glucose, urea and the activities of alkaline phospatase, aspartate aminotransferase and alanine aminotransferase in serum. M. oleifera leaves also prevented the arsenic-induced perturbation of serum butyryl cholinesterase activity, total cholesterol and high density lipoprotein cholesterol. Conclusions The results indicate that the leaves of M. oleifera may be useful in reducing the effects of arsenic-induced toxicity. PMID:25183111

  1. Glutathione peroxidase-1 protects from CD95-induced apoptosis.

    PubMed

    Gouaze, Valerie; Andrieu-Abadie, Nathalie; Cuvillier, Olivier; Malagarie-Cazenave, Sophie; Frisach, Marie-Francoise; Mirault, Marc-Edouard; Levade, Thierry

    2002-11-01

    Through the induction of apoptosis, CD95 plays a crucial role in the immune response and the elimination of cancer cells. Ligation of CD95 receptor activates a complex signaling network that appears to implicate the generation of reactive oxygen species (ROS). This study investigated the place of ROS production in CD95-mediated apoptosis and the role of the antioxidant enzyme glutathione peroxidase-1 (GPx1). Anti-CD95 antibodies triggered an early generation of ROS in human breast cancer T47D cells that was blocked by overexpression of GPx1 and inhibition of initiator caspase activation. Enforced expression of GPx1 also resulted in inhibition of CD95-induced effector caspase activation, DNA fragmentation, and apoptotic cell death. Resistance to CD95-mediated apoptosis was not due to an increased expression of anti-apoptotic molecules and could be reversed by glutathione-depleting agents. In addition, whereas the anti-apoptotic protein Bcl-xL prevented CD95-induced apoptosis in MCF-7 cells, it did not inhibit the early ROS production. Moreover, Bcl-xL but not GPx1 overexpression could suppress the staurosporine-induced late generation of ROS and subsequent cell death. Altogether, these findings suggest that GPx1 functions upstream of the mitochondrial events to inhibit the early ROS production and apoptosis induced by CD95 ligation. Finally, transgenic mice overexpressing GPx1 were partially protected from the lethal effect of anti-CD95, underlying the importance of peroxide formation (and GPx1) in CD95-triggered apoptosis. PMID:12221075

  2. Ameliorative Effect of Tephrosia Purpurea in Arsenic-induced Nephrotoxicity in Rats

    PubMed Central

    Gora, Ravuri Halley; Kerketta, Priscilla; Baxla, Sushma Lalita; Toppo, Reetu; Prasad, Raju; Patra, Pabitra Hriday; Roy, Birendra Kumar

    2014-01-01

    Objectives: The present investigation was conducted to evaluate the nephroprotective activity of Tephrosia purpurea (TPE) against arsenic-induced toxicity. Materials and Methods: Twenty four number of wistar rats were equally divided into three groups. Sodium arsenite (10 mg/kg) was orally given to group I for 28 days, additionally group II was orally treated with TPE (500 mg/kg), while the control group was kept untreated with neither arsenic nor TPE. Serum biomarker levels, oxidative stress indices and arsenic concentration in kidney were estimated. Histopathology of kidney was also conducted. Results: Group II animals show significantly reduced blood urea nitrogen and plasma creatinine, and increased serum albumin level compared to group I. The higher lipid peroxidation with exhausted superoxide dismutase activity and reduced glutathione level were noticed in group I compared to group II. There was no significant difference in arsenic accumulation in kidneys between the two arsenic treated groups, but the histopathology of kidney of group II rats revealed reduced necrosis and intact tubular architecture as compared to group I. Conclusions: Tephrosia Purpurea extract has a significant role in protecting the animals from arsenic-induced nephrotoxicity. PMID:24748739

  3. Taurine induces the apoptosis of breast cancer cells by regulating apoptosis-related proteins of mitochondria.

    PubMed

    Zhang, Xiali; Lu, Hongfei; Wang, Yibing; Liu, Chunju; Zhu, Weifeng; Zheng, Shuangyan; Wan, Fusheng

    2015-01-01

    Taurine (Tau), the most abundant free amino acid in humans has numerous potential health benefits through its antioxidant and anti-inflammatory properties. However, limited studies have assessed its effect on tumors and the antitumor mechanism remains unknown. The present study investigated the cellular and molecular changes induced by Tau, leading to the induction of apoptosis in human breast cancer cell lines MCF-7 and MDA-MB-231. MCF-7 is p53 proficient (p53+/+) and MDA-MB-231 is a p53 null mutant (p53-/-). Cell proliferation and viability were assessed by MTT. Flow cytometry and hoechst33342 fluorescent staining were employed to detect apoptosis. Spectrophotometry was used to detect caspase-3 activity. Reverse transcription-polymerase chain reaction and western blot analysis were used to detect the levels of mRNA and proteins of p53-upregulated modulator of apoptosis (PUMA), Bax and Bcl-2. Finally, the affect of Tau on the growth of MDA-MB-231-cell-nude mice xenografts was examined. In the study, Tau inhibited growth and induced apoptosis of the two cell lines in a concentration- and time-dependent manner. Notably, the inhibitory effect of Tau on p53-/- cancer cells was clearly significant compared to the p53+/+ cancer cells. Further studies showed that Tau promoted apoptosis in human breast cancer cells and inhibited the growth of tumor in nude mice by inducing the expression of PUMA, which further up- and downregulated the expression of Bax and Bcl-2 protein, giving rise to increased activation of caspase-3. Collectively, these results indicate that Tau is a potent candidate for the chemotherapy of breast cancer through increasing the PUMA expression independent of p53 status. PMID:25395275

  4. MG132, a proteasome inhibitor, induces apoptosis in tumor cells.

    PubMed

    Guo, Na; Peng, Zhilan

    2013-03-01

    The balance between cell proliferation and apoptosis is critical for normal development and for the maintenance of homeostasis in adult organisms. Disruption of this balance has been implicated in a large number of disease processes, ranging from autoimmunity and neurodegenerative disorders to cancer. The ubiquitin-proteasome pathway, responsible for mediating the majority of intracellular proteolysis, plays a crucial role in the regulation of many normal cellular processes, including the cell cycle, differentiation and apoptosis. Apoptosis in cancer cells is closely connected with the activity of ubiquitin-proteasome pathway. The peptide-aldehyde proteasome inhibitor MG132 (carbobenzoxyl-L-leucyl-L-leucyl-L-leucine) induces the apoptosis of cells by a different intermediary pathway. Although the pathway of induction of apoptosis is different, it plays a crucial role in anti-tumor treatment. There are many cancer-related molecules in which the protein levels present in cells are regulated by a proteasomal pathway; for example, tumor inhibitors (P53, E2A, c-Myc, c-Jun, c-Fos), transcription factors (transcription factor nuclear factor-kappa B, IκBα, HIFI, YYI, ICER), cell cycle proteins (cyclin A and B, P27, P21, IAP1/3), MG132 induces cell apoptosis through formation of reactive oxygen species or the upregulation and downregulation of these factors, which is ultimately dependent upon the activation of the caspase family of cysteine proteases. In this article we review the mechanism of the induction of apoptosis in order to provide information required for research. PMID:22897979

  5. Arsenic induces structural and compositional colonic microbiome change and promotes host nitrogen and amino acid metabolism.

    PubMed

    Dheer, Rishu; Patterson, Jena; Dudash, Mark; Stachler, Elyse N; Bibby, Kyle J; Stolz, Donna B; Shiva, Sruti; Wang, Zeneng; Hazen, Stanley L; Barchowsky, Aaron; Stolz, John F

    2015-12-15

    Chronic exposure to arsenic in drinking water causes cancer and non-cancer diseases. However, mechanisms for chronic arsenic-induced pathogenesis, especially in response to lower exposure levels, are unclear. In addition, the importance of health impacts from xeniobiotic-promoted microbiome changes is just being realized and effects of arsenic on the microbiome with relation to disease promotion are unknown. To investigate impact of arsenic exposure on both microbiome and host metabolism, the stucture and composition of colonic microbiota, their metabolic phenotype, and host tissue and plasma metabolite levels were compared in mice exposed for 2, 5, or 10weeks to 0, 10 (low) or 250 (high) ppb arsenite (As(III)). Genotyping of colonic bacteria revealed time and arsenic concentration dependent shifts in community composition, particularly the Bacteroidetes and Firmicutes, relative to those seen in the time-matched controls. Arsenic-induced erosion of bacterial biofilms adjacent to the mucosal lining and changes in the diversity and abundance of morphologically distinct species indicated changes in microbial community structure. Bacterical spores increased in abundance and intracellular inclusions decreased with high dose arsenic. Interestingly, expression of arsenate reductase (arsA) and the As(III) exporter arsB, remained unchanged, while the dissimilatory nitrite reductase (nrfA) gene expression increased. In keeping with the change in nitrogen metabolism, colonic and liver nitrite and nitrate levels and ratios changed with time. In addition, there was a concomitant increase in pathogenic arginine metabolites in the mouse circulation. These data suggest that arsenic exposure impacts the microbiome and microbiome/host nitrogen metabolism to support disease enhancing pathogenic phenotypes. PMID:26529668

  6. Salmonella typhimurium Invasion Induces Apoptosis in Infected Macrophages

    NASA Astrophysics Data System (ADS)

    Monack, Denise M.; Raupach, Barbel; Hromockyj, Alexander E.; Falkow, Stanley

    1996-09-01

    Invasive Salmonella typhimurium induces dramatic cytoskeletal changes on the membrane surface of mammalian epithelial cells and RAW264.7 macrophages as part of its entry mechanism. Noninvasive S. typhimurium strains are unable to induce this membrane ruffling. Invasive S. typhimurium strains invade RAW264.7 macrophages in 2 h with 7- to 10-fold higher levels than noninvasive strains. Invasive S. typhimurium and Salmonella typhi, independent of their ability to replicate intracellularly, are cytotoxic to RAW264.7 macrophages and, to a greater degree, to murine bone marrow-derived macrophages. Here, we show that the macrophage cytotoxicity mediated by invasive Salmonella is apoptosis, as shown by nuclear morphology, cytoplasmic vacuolization, and host cell DNA fragmentation. S. typhimurium that enter cells causing ruffles but are mutant for subsequent intracellular replication also initiate host cell apoptosis. Mutant S. typhimurium that are incapable of inducing host cell membrane ruffling fail to induce apoptosis. The activation state of the macrophage plays a significant role in the response of macrophages to Salmonella invasion, perhaps indicating that the signal or receptor for initiating programmed cell death is upregulated in activated macrophages. The ability of Salmonella to promote apoptosis may be important for the initiation of infection, bacterial survival, and escape of the host immune response.

  7. Sustained adenosine exposure causes lung endothelial apoptosis: a possible contributor to cigarette smoke-induced endothelial apoptosis and lung injury

    PubMed Central

    Sakhatskyy, Pavlo; Newton, Julie; Shamirian, Paul; Hsiao, Vivian; Curren, Sean; Gabino Miranda, Gustavo Andres; Pedroza, Mesias; Blackburn, Michael R.; Rounds, Sharon

    2013-01-01

    Pulmonary endothelial cell (EC) apoptosis has been implicated in the pathogenesis of emphysema. Cigarette smoke (CS) causes lung EC apoptosis and emphysema. In this study, we show that CS exposure increased lung tissue adenosine levels in mice, an effect associated with increased lung EC apoptosis and the development of emphysema. Adenosine has a protective effect against apoptosis via adenosine receptor-mediated signaling. However, sustained elevated adenosine increases alveolar cell apoptosis in adenosine deaminase-deficient mice. We established an in vitro model of sustained adenosine exposure by incubating lung EC with adenosine in the presence of an adenosine deaminase inhibitor, deoxycoformicin. We demonstrated that sustained adenosine exposure caused lung EC apoptosis via nucleoside transporter-facilitated intracellular adenosine uptake, subsequent activation of p38 and JNK in mitochondria, and ultimately mitochondrial defects and activation of the mitochondria-mediated intrinsic pathway of apoptosis. Our results suggest that sustained elevated adenosine may contribute to CS-induced lung EC apoptosis and emphysema. Our data also reconcile the paradoxical effects of adenosine on apoptosis, demonstrating that prolonged exposure causes apoptosis via nucleoside transporter-mediated intracellular adenosine signaling, whereas acute exposure protects against apoptosis via activation of adenosine receptors. Inhibition of adenosine uptake may become a new therapeutic target in treatment of CS-induced lung diseases. PMID:23316066

  8. Chemotherapeutic-Induced Apoptosis – A Phenotype for Pharmacogenomics Studies

    PubMed Central

    Wen, Yujia; Gorsic, Lidija K.; Wheeler, Heather E.; Ziliak, Dana M.; Huang, R. Stephanie; Dolan, M. Eileen

    2011-01-01

    Lymphoblastoid cell lines have been used as a model system to identify genetic determinants of chemotherapeutic-induced cytotoxicity, a phenotype thought to represent cellular sensitivity to drug. However, cytotoxicity is a broad measurement encompassing cell cycle inhibition as well as cell death (apoptotic and non-apoptotic). We evaluated caspase 3/7 mediated cellular apoptosis with six chemotherapeutic agents: 5′-deoxy-fluorouridine, pemetrexed, cytarabine, paclitaxel, carboplatin and cisplatin. Using monozygotic twin pair and sibling pair lymphoblastoid cell lines, we identified conditions for measurement of caspase activity. Although treatment with 5′-deoxy-fluorouridine and pemetrexed for up to 24 h did not result in significant apoptosis or inter-individual variation in caspase dependent cell death; paclitaxel, cisplatin, carboplain and cytarabine treatment for 24 h resulted in 9.4, 9.1, 7.0 and 6.0 fold increases in apoptosis relative to control, respectively. There was a weak correlation between caspase activity and cytotoxicity (r2=0.03 to 0.29) demonstrating that cytotoxicity and apoptosis are two distinct phenotypes that may produce independent genetic associations. Estimated heritability (h2) for apoptosis was 0.57 and 0.29 for cytarabine (5 μM and 40 μM respectively), 0.22 for paclitaxel (12.5 nM), and 0.34 for cisplatin (5 μM). The HapMap CEU panel of lymphoblastoid cell lines (n = 77) were evaluated for sensitivity to cisplatin followed by genome wide association studies with over 2 million SNPs at p < 0.001. We identified a significant enrichment of cisplatin-induced apoptosis SNPs within the significant cisplatin induced cytotoxicity SNPs and an enrichment of expression quantitative trait loci. PMID:21642893

  9. 2,3,5,6-Tetramethylpyrazine (TMP) down-regulated arsenic-induced heme oxygenase-1 and ARS2 expression by inhibiting Nrf2, NF-κB, AP-1 and MAPK pathways in human proximal tubular cells.

    PubMed

    Gong, Xuezhong; Ivanov, Vladimir N; Hei, Tom K

    2016-09-01

    Our recent study demonstrated that sodium arsenite at a clinically relevant dose induced nephrotoxicity in human renal proximal tubular epithelial cell line HK-2, which could be inhibited by natural product 2,3,5,6-tetramethylpyrazine (TMP) with antioxidant activity. The present study demonstrated that arsenic exposure resulted in protein and enzymatic induction of heme oxygenase-1 (HO-1) in dose- and time-dependent manners in HK-2 cells. Blocking HO-1 enzymatic activity by zinc protoporphyrin (ZnPP) augmented arsenic-induced apoptosis, ROS production and mitochondrial dysfunction, suggesting a critical role for HO-1 as a renal protectant in this procession. On the other hand, TMP, upstream of HO-1, inhibited arsenic-induced ROS production and ROS-dependent HO-1 expression. TMP also prevented mitochondria dysfunction and suppressed activation of the intrinsic apoptotic pathway in HK-2 cells. Our results revealed that the regulation of arsenic-induced HO-1 expression was performed through multiple ROS-dependent signal pathways and the corresponding transcription factors, including p38 MAPK and JNK (but not ERK), AP-1, Nrf2 and NF-κB. TMP inhibited arsenic-induced activations of JNK, p38 MAPK, ERK, AP-1 and Nrf2 and block HO-1 protein expression. The present study, furthermore, demonstrated arsenic-induced expression of arsenic response protein 2 (ARS2) that was regulated by p38 MAPK, ERK and NF-κB. To our knowledge, this is the first report showing that ARS2 involved in arsenic-induced nephrotoxicity, while TMP pretreatment prevented such an up-regulation of ARS2 in HK-2 cells. Given ARS2 and HO-1 sharing the similar regulation mechanism, we speculated that ARS2 might also mediate cell survival in this procession. In summary, our study highlighted a role of HO-1 in the protection against arsenic-induced cytotoxicity downstream from the primary targets of TMP and further indicated that TMP may be used as a potential therapeutic agent in the treatment of arsenic-induced

  10. Capsaicin induces apoptosis in PC12 cells through ER stress.

    PubMed

    Krizanova, Olga; Steliarova, Iveta; Csaderova, Lucia; Pastorek, Michal; Hudecova, Sona

    2014-02-01

    Capsaicin, the pungent agent in chili peppers, has been shown to act as a tumor-suppressor in cancer. In our previous study, capsaicin was shown to induce apoptosis in the rat pheochromocytoma cell line (PC12 cells). Thus, the aim of the present study was to determine the potential mechanism by which capsaicin induces apoptosis. We treated PC12 cells with 50, 100 and 500 µM capsaicin and measured the reticular calcium content and expression of the reticular calcium transport systems. These results were correlated with endoplasmic reticulum (ER) stress markers CHOP, ATF4 and X-box binding protein 1 (XBP1), as well as with apoptosis induction. We observed that capsaicin decreased reticular calcium in a concentration-dependent manner. Simultaneously, expression levels of the sarco/endoplasmic reticulum pump and ryanodin receptor of type 2 were modified. These changes were accompanied by increased ER stress, as documented by increased stress markers. Thus, from these results we propose that in PC12 cells capsaicin induces apoptosis through increased ER stress. PMID:24337105

  11. Lipopolysaccharide-Induced Apoptosis of Astrocytes: Therapeutic Intervention by Minocycline.

    PubMed

    Sharma, Arpita; Patro, Nisha; Patro, Ishan K

    2016-05-01

    Astrocytes are most abundant glial cell type in the brain and play a main defensive role in central nervous system against glutamate-induced toxicity by virtue of numerous transporters residing in their membranes and an astrocyte-specific enzyme glutamine synthetase (GS). In view of that, a dysregulation in the astrocytic activity following an insult may result in glutamate-mediated toxicity accompanied with astrocyte and microglial activation. The present study suggests that the lipopolysaccharide (LPS)-induced inflammation results in significant astrocytic apoptosis compared to other cell types in hippocampus and minocycline could not efficiently restrict the glutamate-mediated toxicity and apoptosis of astrocytes. Upon LPS exposure 76 % astrocytes undergo degeneration followed by 44 % oligodendrocytes, 26 % neurons and 10 % microglia. The pronounced astrocytic apoptosis resulted from the LPS-induced glutamate excitotoxicity leading to their hyperactivation as evident from their hypertrophied morphology, glutamate transporter 1 upregulation and downregulation of GS. Therapeutic minocycline treatment to LPS-infused rats efficiently restricted the inflammatory response and degeneration of other cell types but could not significantly combat with the apoptosis of astrocytes. Our study demonstrates a novel finding on cellular degeneration in the hippocampus revealing more of astrocytic death and suggests a more careful consideration on the protective efficacy of minocycline. PMID:26188416

  12. Phytoconstituents as apoptosis inducing agents: strategy to combat cancer.

    PubMed

    Kumar, Manish; Kaur, Varinder; Kumar, Subodh; Kaur, Satwinderjeet

    2016-08-01

    Advancement in the field of cancer molecular biology has aided researchers to develop various new chemopreventive agents which can target cancer cells exclusively. Cancer chemopreventive agents have proficiency to inhibit, reverse and delay process of carcinogenesis during its early and later course. Chemopreventive agents can act as antioxidative, antimutagenic/antigenotoxic, anti-inflammatory agents or via aiming various molecular targets in a cell to induce cell death. Apoptosis is a kind of cell death which shows various cellular morphological alterations such as cell shrinkage, blebbing of membrane, chromatin condensation, DNA fragmentation, formation of apoptotic bodies etc. Nowadays, apoptosis is being one of the new approaches for the identification and development of novel anticancer therapies. For centuries, plants are known to play part in daily routine from providing food to management of human health. In the last two decades, diverse phytochemicals and various botanical formulations have been characterized as agents that possess potential to execute cancer cells via inducing apoptosis. Data obtained from the research carried out globally pointed out that natural products are the potential candidates which have capability to combat cancer. In the present review, we surveyed literature on natural products which throws light on the mechanism through which these phytochemicals induce apoptosis in cancer cells. PMID:26239338

  13. Determinants of PDT-induced apoptosis

    NASA Astrophysics Data System (ADS)

    Kessel, David; Luo, Yu; Kim, Hyeong-Reh C.

    2000-03-01

    Photodynamic therapy can initiate cell death by apoptosis or necrosis. Using agents with known patterns of sub-cellular localization, we examined the correlation between sites of photodamage and the mode of cell death, using murine leukemia cells in vitro. Mitochondrial or mitochondrial/lysosomal photodamage caused the rapid release of cytochrome c. This effect was not temperature sensitive, and could be demonstrated immediately after irradiation of photosensitized cells at 10 degrees C. Subsequent warming to 37 degrees C led to a rapid apoptotic response, consistent with the known ability of cytochrome c to trigger the activation of caspase-3. In contrast, lysosomal or lysosomal/membrane photodamage resulted in the release of cathepsins and other proteolytic enzymes. A subsequent incubation at 37 degrees C resulted in mitochondrial degradation, leading to loss of cytochrome c within 30 min. The apoptotic response was both delayed and incomplete, with many dead cells not exhibiting an apoptotic morphology. The latter outcome was traced to photodamage to procaspase-3, an effect not observed with sensitizers that caused mainly mitochondrial photodamage. Studies in a cell-free system demonstrated that agents with lysosomal and/or membrane targets could bring about photoinactivation of caspase-3. These result are consistent with the proposal that photodynamic therapy can both activate and inactivate components of the apoptotic process.

  14. Dysregulation of DNA methylation induced by past arsenic treatment causes persistent genomic instability in mammalian cells.

    PubMed

    Mauro, Maurizio; Caradonna, Fabio; Klein, Catherine B

    2016-03-01

    The mechanisms by which arsenic-induced genomic instability is initiated and maintained are poorly understood. To investigate potential epigenetic mechanisms, in this study we evaluated global DNA methylation levels in V79 cells and human HaCaT keratinocytes at several time points during expanded growth of cell cultures following removal of arsenite exposures. We have found altered genomic methylation patterns that persisted up to 40 cell generations in HaCaT cells after the treatments were withdrawn. Moreover, mRNA expression levels were evaluated by RT-PCR for DNMT1, DNMT3A, DNMT3B, HMLH1, and HMSH2 genes, demonstrating that the down regulation of DNMT3A and DNMT3B genes, but not DNMT1, occurred in an arsenic dose-dependent manner, and persisted for many cell generations following removal of the arsenite, offering a plausible mechanism of persistently genotoxic arsenic action. Analyses of promoter methylation status of the DNA mismatch repair genes HMLH1 and HMSH2 show that HMSH2, but not HMLH1, was epigenetically regulated by promoter hypermethylation changes following arsenic treatment. The results reported here demonstrate that arsenic exposure promptly induces genome-wide global DNA hypomethylation, and some specific gene promoter methylation changes, that persist for many cell generations following withdrawal of arsenite, supporting the hypothesis that the cells undergo epigenetic reprogramming at both the gene and genome level that is durable over many cell generations in the absence of further arsenic treatment. These DNA methylation changes, in concert with other known epigenome alterations, are likely contributing to long-lasting arsenic-induced genomic instability that manifests in several ways, including aberrant chromosomal effects. PMID:26581878

  15. Dysregulation of DNA Methylation Induced by Past Arsenic Treatment Causes Persistent Genomic Instability in Mammalian Cells

    PubMed Central

    Mauro, Maurizio; Caradonna, Fabio; Klein, Catherine B.

    2016-01-01

    The mechanisms by which arsenic-induced genomic instability is initiated and maintained are poorly understood. To investigate potential epigenetic mechanisms, in this study we evaluated global DNA methylation levels in V79 cells and human HaCaT keratinocytes at several time points during expanded growth of cell cultures following removal of arsenite exposures. We have found altered genomic methylation patterns that persisted up to 40 cell generations in HaCaT cells after the treatments were withdrawn. Moreover, mRNA expression levels were evaluated by RT-PCR for DNMT1, DNMT3A, DNMT3B, HMLH1, and HMSH2 genes, demonstrating that the down regulation of DNMT3A and DNMT3B genes, but not DNMT1, occurred in an arsenic dose-dependent manner, and persisted for many cell generations following removal of the arsenite, offering a plausible mechanism of persistently genotoxic arsenic action. Analyses of promoter methylation status of the DNA mismatch repair genes HMLH1 and HMSH2 show that HMSH2, but not HMLH1, was epigenetically regulated by promoter hypermethylation changes following arsenic treatment. The results reported here demonstrate that arsenic exposure promptly induces genome-wide global DNA hypomethylation, and some specific gene promoter methylation changes, that persist for many cell generations following withdrawal of arsenite, supporting the hypothesis that the cells undergo epigenetic reprogramming at both the gene and genome level that is durable over many cell generations in the absence of further arsenic treatment. These DNA methylation changes, in concert with other known epigenome alterations, are likely contributing to long-lasting arsenic-induced genomic instability that manifests in several ways, including aberrant chromosomal effects. PMID:26581878

  16. Plasma-activated medium induced apoptosis on tumor cells

    NASA Astrophysics Data System (ADS)

    Hori, Masaru; Tanaka, Hiromasa; Mizuno, Masaaki; Nakamura, Kae; Kajiyama, Hiroaki; Takeda, Keigo; Ishikawa, Kenji; Kano, Hiroyuki; Kikkawa, Fumitaka

    2013-09-01

    The non-equilibrium atmospheric pressure plasma (NEAPP) has attracted attention in cancer therapy. In this study, the fresh medium was treated with our developed NEAPP, ultra-high electron density (approximately 2 × 1016 cm-3). The medium called the plasma-activated medium (PAM) killed not normal cells but tumor cells through induction of apoptosis. Cell proliferation assays showed that the tumor cells were selectively killed by the PAM. Those cells induced apoptosis using an apoptotic molecular marker, cleaved Caspase3/7. The molecular mechanisms of PAM-mediated apoptosis in the tumor cells were also found that the PAM downregulated the expression of AKT kinase, a marker molecule in a survival signal transduction pathway. These results suggest that PAM may be a promising tool for tumor therapy by downregulating the survival signals in cancers.

  17. p73-induced apoptosis: A question of compartments and cooperation

    SciTech Connect

    Dobbelstein, Matthias; Strano, Sabrina; Roth, Judith; Blandino, Giovanni . E-mail: blandino@ifo.it

    2005-06-10

    The transcriptionally active forms of p73 are capable of inducing apoptosis, and the isoforms termed TAp73 are important players when E2F and its oncogenic activators induce programmed cell death. However, the conditions under that TAp73 can kill a cell remain to be clarified. Recently, it has been found that p73 proteins are not merely floating in the nucleoplasm but rather can associate with specific compartments in the cell. Examples of intranuclear compartments associated with p73 proteins include the PML oncogenic domains and the nuclear matrix. In addition, p73 is found in the cytoplasm. It remains to be seen whether p73 might also associate with mitochondria, in analogy with p53. The relocalization of p73 is expected to be mediated by specific binding partners, mostly other proteins. Here, we discuss the possibility that the compartmentalization of p73, and the cooperation with the corresponding binding partners, might decide about its apoptosis-inducing activity.

  18. Molecular Mechanisms of Particle Ration Induced Apoptosis in Lymphocyte

    NASA Astrophysics Data System (ADS)

    Shi, Yufang

    Space radiation, composed of high-energy charged nuclei (HZE particles) and protons, has been previously shown to severely impact immune homeostasis in mice. To determine the molecular mechanisms that mediate acute lymphocyte depletion following exposure to HZE particle radiation mice were exposed to particle radiation beams at Brookhaven National Laboratory. We found that mice given whole body 5 6Fe particle irradiation (1GeV /n) had dose-dependent losses in total lymphocyte numbers in the spleen and thymus (using 200, 100 and 50 cGy), with thymocytes being more sensitive than splenocytes. All phenotypic subsets were reduced in number. In general, T cells and B cells were equally sensitive, while CD8+ T cells were more senstive than CD4+ T cells. In the thymus, immature CD4+CD8+ double-positive thymocytes were exquisitely sensitive to radiation-induced losses, single-positive CD4 or CD8 cells were less sensitive, and the least mature double negative cells were resistant. Irradiation of mice deficient in genes encoding essential apoptosis-inducing proteins revealed that the mechanism of lymphocyte depletion is independent of Fas ligand and TRAIL (TNF-ralated apoptosis-inducing ligand), in contrast to γ-radiation-induced lymphocyte losses which require the Fas-FasL pathway. Using inhibitors in vitro, lymphocyte apoptosis induced by HZE particle radiation was found to be caspase dependent, and not involve nitric oxide or oxygen free radicals.

  19. High soil and groundwater arsenic levels induce high body arsenic loads, health risk and potential anemia for inhabitants of northeastern Iran.

    PubMed

    Taheri, Masumeh; Mehrzad, Jalil; Mahmudy Gharaie, Mohamad Hosein; Afshari, Reza; Dadsetan, Ahmad; Hami, Shakiba

    2016-04-01

    Arsenic bioavailability in rock, soil and water resources is notoriously hazardous. Geogenic arsenic enters the body and adversely affects many biochemical processes in animals and humans, posing risk to public health. Chelpu is located in NE Iran, where realgar, orpiment and pyrite mineralization is the source of arsenic in the macroenvironment. Using cluster random sampling strategy eight rocks, 23 soils, 12 drinking water resources, 36 human urine and hair samples and 15 adult sheep urine and wool samples in several large-scale herds in the area were randomly taken for quantification of arsenic in rock/soil/water, wool/hair/urine. Arsenic levels in rock/soil/water and wool/hair/urine were measured using inductively coupled plasma spectroscopy and atomic absorption spectrophotometry, respectively. While arsenic levels in rocks, soils and water resources hazardously ranged 9.40-25,873.3 mg kg(-1), 7.10-1448.80 mg kg(-1) and 12-606 μg L(-1), respectively, arsenic concentrations in humans' hair and urine and sheep's wool and urine varied from 0.37-1.37 μg g(-1) and 9-271.4 μg L(-1) and 0.3-3.11 μg g(-1) and 29.1-1015 μg L(-1), respectively. Local sheep and human were widely sick and slightly anemic. Hematological examination of the inhabitants revealed that geogenic arsenic could harm blood cells, potentially resulting in many other hematoimmunological disorders including cancer. The findings warn widespread exposure of animals and human in this agroecologically and geopolitically important region (i.e., its proximity with Afghanistan, Pakistan and Turkmenistan) and give a clue on how arsenic could induce infectious and non-infectious diseases in highly exposed human/animals. PMID:26100324

  20. Effect of Centella asiatica on arsenic induced oxidative stress and metal distribution in rats.

    PubMed

    Gupta, Richa; Flora, S J S

    2006-01-01

    Concomitant oral supplementation of Centella asiatica (100, 200 or 300 mg kg(-1), orally once daily) during arsenic exposure (20 ppm in drinking water for 4 weeks) was investigated in rats for its protective value. The animals exposed to arsenic (III) showed a significant inhibition of delta-aminolevulinic acid dehydratase (ALAD) activity, a marginal decrease in glutathione (GSH) and an increase in zinc protoporphyrin (ZPP) level in blood. Hepatic and renal glutathione (GSH) decreased, while oxidized glutathione (GSSG) and thiobarbituric acid reactive substance (TBARS) levels increased significantly in the liver, kidney and brain. The activities of brain superoxide dismutase (SOD) and catalase decreased marginally on arsenic exposure. Concomitant administration of Centella asiatica showed a significant protective action on inhibited blood ALAD activity and restored the blood GSH level, whereas most of the other blood biochemical parameters remained unchanged on Centella asiatica supplementation. Interestingly, most of the hepatic biochemical variables indicative of oxidative stress showed protection. There was, however, a significant protection observed in the altered kidney GSSG level and hepatic and brain TBARS. Only a marginal beneficial effect of Centella asiatica on blood and liver arsenic concentration was noted, particularly at the highest dose studies (300 mg kg(-1)). No effect of Centella asiatica on most of the altered renal biochemical parameters was noted. The results thus lead to the conclusion that simultaneous supplementation of Centella asiatica significantly protects against arsenic-induced oxidative stress but does not influence the arsenic concentration in these organs. It can thus be suggested that co-administration of Centella asiatica protects animals from arsenic-induced oxidative stress but exhibits no chelating property. Further studies are recommended for determining the effect of co-administration of Centella asiatica during chelation

  1. GENE METHYLATION CHANGES IN TUMOR SUPPRESSOR GENES INDUCED BY ARSENIC

    EPA Science Inventory

    The choice of a dose-response model used for extrapolation can be influenced by knowledge of mechanism of action. We have already showed that arsenic affects methylation of the human p53 gene promoter. Evidence that genes other than the p53 tumor suppressor gene are affected woul...

  2. FOLATE DEFICIENCY ENHANCES ARSENIC-INDUCED GENOTOXICITY IN MICE

    EPA Science Inventory

    Folate deficiency increases background levels of DNA damage and can enhance the mutagenicity of chemical agents. Duplicate experiments were performed to investigate the effect of dietary folate deficiency on arsenic induction of micronuclei (MN) in peripheral blood cells. Male C5...

  3. Herbal Medicine as Inducers of Apoptosis in Cancer Treatment

    PubMed Central

    Safarzadeh, Elham; Sandoghchian Shotorbani, Siamak; Baradaran, Behzad

    2014-01-01

    Cancer is uncontrolled growth of abnormal cells in the body. Nowadays, cancer is considered as a human tragedy and one of the most prevalent diseases in the wide, and its mortality resulting from cancer is being increased. It seems necessary to identify new strategies to prevent and treat such a deadly disease. Control survival and death of cancerous cell are important strategies in the management and therapy of cancer. Anticancer agents should kill the cancerous cell with the minimal side effect on normal cells that is possible through the induction of apoptosis. Apoptosis is known as programmed cell death in both normal and damaged tissues. This process includes some morphologically changes in cells such as rapid condensation and budding of the cell, formation of membrane-enclosed apoptotic bodies with well-preserved organelles. Induction of apoptosis is one of the most important markers of cytotoxic antitumor agents. Some natural compounds including plants induce apoptotic pathways that are blocked in cancer cells through various mechanisms in cancer cells. Multiple surveys reported that people with cancer commonly use herbs or herbal products. Vinca Alkaloids, Texans, podo phyllotoxin, Camptothecins have been clinically used as Plant derived anticancer agents. The present review summarizes the literature published so far regarding herbal medicine used as inducers of apoptosis in cancer. PMID:25364657

  4. Herbal medicine as inducers of apoptosis in cancer treatment.

    PubMed

    Safarzadeh, Elham; Sandoghchian Shotorbani, Siamak; Baradaran, Behzad

    2014-10-01

    Cancer is uncontrolled growth of abnormal cells in the body. Nowadays, cancer is considered as a human tragedy and one of the most prevalent diseases in the wide, and its mortality resulting from cancer is being increased. It seems necessary to identify new strategies to prevent and treat such a deadly disease. Control survival and death of cancerous cell are important strategies in the management and therapy of cancer. Anticancer agents should kill the cancerous cell with the minimal side effect on normal cells that is possible through the induction of apoptosis. Apoptosis is known as programmed cell death in both normal and damaged tissues. This process includes some morphologically changes in cells such as rapid condensation and budding of the cell, formation of membrane-enclosed apoptotic bodies with well-preserved organelles. Induction of apoptosis is one of the most important markers of cytotoxic antitumor agents. Some natural compounds including plants induce apoptotic pathways that are blocked in cancer cells through various mechanisms in cancer cells. Multiple surveys reported that people with cancer commonly use herbs or herbal products. Vinca Alkaloids, Texans, podo phyllotoxin, Camptothecins have been clinically used as Plant derived anticancer agents. The present review summarizes the literature published so far regarding herbal medicine used as inducers of apoptosis in cancer. PMID:25364657

  5. Infrasound sensitizes human glioblastoma cells to cisplatin-induced apoptosis.

    PubMed

    Rachlin, Kenneth; Moore, Dan H; Yount, Garret

    2013-11-01

    The development of nontoxic agents that can selectively enhance the cytotoxicity of chemotherapy is an important aim in oncology. This study evaluates the ability of infrasound exposure to sensitize glioblastoma cells to cisplatin-induced apoptosis. The infrasound was delivered using a device designed to replicate the unique infrasound emissions measured during external Qigong treatments. Human glioblastoma cell lines harboring wild-type p53 (U87) or mutant p53 (U251, SF210, and SF188) were treated in culture with cisplatin, infrasound emissions, or the combination of the 2 agents. Induction of apoptosis was quantified after 24 hours by flow cytometry following annexin V/propidium iodide staining. Infrasound emissions alone, delivered at moderate levels (~10 mPa) with dynamic frequency content (7-13 Hz), did not induce apoptosis, yet combining infrasound with cisplatin augmented the induction of apoptosis by cisplatin in all the 4 cell lines (P < .05). Increased cellular uptake of the fluorophore calcein associated with infrasound exposure was quantified by fluorescence microscopy as well as flow cytometry, demonstrating increased cell membrane permeability. The 4 cell lines differed in the degree to which infrasound exposure increased calcein uptake, and these differences were predictive of the extent to which infrasound enhanced cisplatin-induced apoptosis. When exposed to specific frequencies, membrane permeabilization also appeared to be differentially responsive for each cell line, suggesting the potential for selective targeting of tissue types using isolated infrasonic frequencies. Additionally, the pressure amplitudes used in this study were several orders of magnitude less than those used in similar studies involving ultrasound and shock waves. The results of this study provide support for using infrasound to enhance the chemotherapeutic effects of cisplatin in a clinical setting. PMID:23165942

  6. Minerval induces apoptosis in Jurkat and other cancer cells

    PubMed Central

    Llado, Victoria; Gutierrez, Antonio; Martínez, Jordi; Casas, Jesús; Terés, Silvia; Higuera, Mónica; Galmés, Antonio; Saus, Carles; Besalduch, Joan; Busquets, Xavier; Escribá, Pablo V

    2010-01-01

    Abstract Minerval is an oleic acid synthetic analogue that impairs lung cancer (A549) cell proliferation upon modulation of the plasma membrane lipid structure and subsequent regulation of protein kinase C localization and activity. However, this mechanism does not fully explain the regression of tumours induced by this drug in animal models of cancer. Here we show that Minerval also induced apoptosis in Jurkat T-lymphoblastic leukaemia and other cancer cells. Minerval inhibited proliferation of Jurkat cells, concomitant with a decrease of cyclin D3 and cdk2 (cyclin-dependent kinase2). In addition, the changes that induced on Jurkat cell membrane organization caused clustering (capping) of the death receptor Fas (CD95), caspase-8 activation and initiation of the extrinsic apoptosis pathway, which finally resulted in programmed cell death. The present results suggest that the intrinsic pathway (associated with caspase-9 function) was activated downstream by caspase-8. In a xenograft model of human leukaemia, Minerval also inhibited tumour progression and induced tumour cell death. Studies carried out in a wide variety of cancer cell types demonstrated that apoptosis was the main molecular mechanism triggered by Minerval. This is the first report on the pro-apoptotic activity of Minerval, and in part explains the effectiveness of this non-toxic anticancer drug and its wide spectrum against different types of cancer. PMID:19413889

  7. AIM2 inflammasome mediates Arsenic-induced secretion of IL-1 β and IL-18.

    PubMed

    Zhang, Mingfang; Qi, Yuanlin; Li, Hui; Cui, Jiajun; Dai, Lu; Frank, Jacqueline A; Chen, Jian; Xu, Wenhua; Chen, Gang

    2016-06-01

    Chronic sterile inflammation has been implicated in the pathogenesis of many cancers, including skin cancer. Chronic arsenic exposure is closely associated with the development of skin cancer. However, there is a lack of understanding how arsenic induces chronic inflammation in the skin. Interleukin-1 family cytokines play a central role in regulating immune and inflammatory response. IL-1α, IL-1β and IL-18 are three pro-inflammatory cytokines in IL-1 family. Their secretion, especially the secretion of IL-1β and IL-18, is regulated by inflammasomes which are multi-protein complexes containing sensor proteins, adaptor protein and caspase-1. The data from current study show sub-chronic arsenic exposure activates AIM2 inflammasome which in turn activates caspase-1 and enhances the secretion of IL-1β and IL-18 in HaCaT cells and the skin of BALB/c mice. In addition, arsenic-promoted activation of AIM2 inflammasome and increase of IL-1β/IL-18 production are inhibited by PKR inhibitor in HaCaT cells or in the skin of PKR mutant mice, indicating a potential role of PKR in arsenic-induced sterile inflammation. PMID:27471628

  8. AIM2 inflammasome mediates Arsenic-induced secretion of IL-1 β and IL-18

    PubMed Central

    Zhang, Mingfang; Qi, Yuanlin; Li, Hui; Cui, Jiajun; Dai, Lu; Frank, Jacqueline A.; Chen, Jian; Xu, Wenhua; Chen, Gang

    2016-01-01

    ABSTRACT Chronic sterile inflammation has been implicated in the pathogenesis of many cancers, including skin cancer. Chronic arsenic exposure is closely associated with the development of skin cancer. However, there is a lack of understanding how arsenic induces chronic inflammation in the skin. Interleukin-1 family cytokines play a central role in regulating immune and inflammatory response. IL-1α, IL-1β and IL-18 are three pro-inflammatory cytokines in IL-1 family. Their secretion, especially the secretion of IL-1β and IL-18, is regulated by inflammasomes which are multi-protein complexes containing sensor proteins, adaptor protein and caspase-1. The data from current study show sub-chronic arsenic exposure activates AIM2 inflammasome which in turn activates caspase-1 and enhances the secretion of IL-1β and IL-18 in HaCaT cells and the skin of BALB/c mice. In addition, arsenic-promoted activation of AIM2 inflammasome and increase of IL-1β/IL-18 production are inhibited by PKR inhibitor in HaCaT cells or in the skin of PKR mutant mice, indicating a potential role of PKR in arsenic-induced sterile inflammation. PMID:27471628

  9. Arsenic-induced SUMO-dependent recruitment of RNF4 into PML nuclear bodies.

    PubMed

    Geoffroy, Marie-Claude; Jaffray, Ellis G; Walker, Katherine J; Hay, Ronald T

    2010-12-01

    In acute promyelocytic leukemia (APL), the promyelocytic leukemia (PML) protein is fused to the retinoic acid receptor alpha (RAR). Arsenic is an effective treatment for this disease as it induces SUMO-dependent ubiquitin-mediated proteasomal degradation of the PML-RAR fusion protein. Here we analyze the nuclear trafficking dynamics of PML and its SUMO-dependent ubiquitin E3 ligase, RNF4 in response to arsenic. After administration of arsenic, PML immediately transits into nuclear bodies where it undergoes SUMO modification. This initial recruitment of PML into nuclear bodies is not dependent on RNF4, but RNF4 quickly follows PML into the nuclear bodies where it is responsible for ubiquitylation of SUMO-modified PML and its degradation by the proteasome. While arsenic restricts the mobility of PML, FRAP analysis indicates that RNF4 continues to rapidly shuttle into PML nuclear bodies in a SUMO-dependent manner. Under these conditions FRET studies indicate that RNF4 interacts with SUMO in PML bodies but not directly with PML. These studies indicate that arsenic induces the rapid reorganization of the cell nucleus by SUMO modification of nuclear body-associated PML and uptake of the ubiquitin E3 ligase RNF4 leading to the ubiquitin-mediated degradation of PML. PMID:20943951

  10. Arsenic-induced cutaneous hyperplastic lesions are associated with the dysregulation of Yap, a Hippo signaling-related protein

    SciTech Connect

    Li, Changzhao; Srivastava, Ritesh K.; Elmets, Craig A.; Afaq, Farrukh; Athar, Mohammad

    2013-09-06

    Highlights: •Arsenic activates canonical Hippo signaling pathway and up-regulates αCatenin in the skin. •Arsenic activates transcriptional activity of Yap by its nuclear translocation. •Yap is involved in the disruption of tight/adherens junctions in arsenic-exposed animals. -- Abstract: Arsenic exposure in humans causes a number of toxic manifestations in the skin including cutaneous neoplasm. However, the mechanism of these alterations remains elusive. Here, we provide novel observations that arsenic induced Hippo signaling pathway in the murine skin. This pathway plays crucial roles in determining organ size during the embryonic development and if aberrantly activated in adults, contributes to the pathogenesis of epithelial neoplasm. Arsenic treatment enhanced phosphorylation-dependent activation of LATS1 kinase and other Hippo signaling regulatory proteins Sav1 and MOB1. Phospho-LATS kinase is known to catalyze the inactivation of a transcriptional co-activator, Yap. However, in arsenic-treated epidermis, we did not observed its inactivation. Thus, as expected, unphosphorylated-Yap was translocated to the nucleus in arsenic-treated epidermis. Yap by binding to the transcription factors TEADs induces transcription of its target genes. Consistently, an up-regulation of Yap-dependent target genes Cyr61, Gli2, Ankrd1 and Ctgf was observed in the skin of arsenic-treated mice. Phosphorylated Yap is important in regulating tight and adherens junctions through its binding to αCatenin. We found disruption of these junctions in the arsenic-treated mouse skin despite an increase in αCatenin. These data provide evidence that arsenic-induced canonical Hippo signaling pathway and Yap-mediated disruption of tight and adherens junctions are independently regulated. These effects together may contribute to the carcinogenic effects of arsenic in the skin.

  11. Reactive oxygen species mediate arsenic induced cell transformation and tumorigenesis through Wnt/{beta}-catenin pathway in human colorectal adenocarcinoma DLD1 cells

    SciTech Connect

    Zhang Zhuo; Wang Xin; Cheng Senping; Sun Lijuan; Son, Young-Ok; Yao Hua; Li Wenqi; Budhraja, Amit; Li Li; Shelton, Brent J.; Tucker, Thomas; Arnold, Susanne M.; Shi Xianglin

    2011-10-15

    Long term exposure to arsenic can increase incidence of human cancers, such as skin, lung, and colon rectum. The mechanism of arsenic induced carcinogenesis is still unclear. It is generally believed that reactive oxygen species (ROS) may play an important role in this process. In the present study, we investigate the possible linkage between ROS, {beta}-catenin and arsenic induced transformation and tumorigenesis in human colorectal adenocarcinoma cell line, DLD1 cells. Our results show that arsenic was able to activate p47{sup phox} and p67{sup phox}, two key proteins for activation of NADPH oxidase. Arsenic was also able to generate ROS in DLD1 cells. Arsenic increased {beta}-catenin expression level and its promoter activity. ROS played a major role in arsenic-induced {beta}-catenin activation. Treatment of DLD1 cells by arsenic enhanced both transformation and tumorigenesis of these cells. The tumor volumes of arsenic treated group were much larger than those without arsenic treatment. Addition of either superoxide dismutase (SOD) or catalase reduced arsenic induced cell transformation and tumor formation. The results indicate that ROS are involved in arsenic induced cell transformation and tumor formation possible through Wnt/{beta}-catenin pathway in human colorectal adenocarcinoma cell line DLD1 cells. - Highlights: > Arsenic activates NADPH oxidase and increases reactive oxygen species generation in DLD1 cells. > Arsenic increases {beta}-catenin expression. > Inhibition of ROS induced by arsenic reduce {beta}-catenin expression. > Arsenic increases cell transformation in DLD1 cells and tumorigenesis in nude mice. > Blockage of ROS decrease cell transformation and tumorigenesis induced by arsenic.

  12. Selenite suppression of cadmium-induced testicular apoptosis.

    PubMed

    Jones, M M; Xu, C; Ladd, P A

    1997-01-15

    The characteristic apoptotic ladder-like patterns of rat testicular DNA on agarose gel electrophoresis which results from treatment with CdCl2 are suppressed by the administration of Na2SeO3. The examination of testicular tissue using an ELISA programmed cell death detection procedure confirmed this selenite suppression of cadmium-induced apoptosis. The administration of the Na2SeO3 at either 0.5, 1, 2 h prior to or 0.5, 1, 2 h after the administration of the CdCl2 appear to be almost equally effective at suppressing the apoptotic response. These results are in accord with previous studies on the Na2SeO3 suppression of cadmium induced necrotic changes in tissues and suggest that Na2SeO3 interferes with both necrosis and apoptosis. PMID:9020518

  13. Pulse mode of laser photodynamic treatment induced cell apoptosis.

    PubMed

    Klimenko, Vladimir V; Knyazev, Nickolay A; Moiseenko, Fedor V; Rusanov, Anatoliy A; Bogdanov, Alexey A; Dubina, Michael V

    2016-03-01

    One of the factors limiting photodynamic therapy (PDT) is hypoxia in tumor cells during photodynamic action. PDT with pulse mode irradiation and appropriate irradiation parameters could be more effective in the singlet oxygen generation and tissue re-oxygenation than continuous wave (CW) mode. We theoretically demonstrate differences between the cumulative singlet oxygen concentration in PDT using pulse mode and CW mode of laser irradiation. In vitro experimental results show that photodynamic treatment with pulse mode irradiation has similar cytotoxicity to CW mode and induces mainly cell apoptosis, whereas CW mode induces necrotic cell death. We assume that the cumulative singlet oxygen concentration and the temporal distribution of singlet oxygen are important in photodynamic cytotoxicity and apoptosis initiation. We expect our research may improve irradiation protocols and photodynamic therapy efficiency. PMID:26790610

  14. Alpha particles induce apoptosis through the sphingomyelin pathway.

    PubMed

    Seideman, Jonathan H; Stancevic, Branka; Rotolo, Jimmy A; McDevitt, Michael R; Howell, Roger W; Kolesnick, Richard N; Scheinberg, David A

    2011-10-01

    The sphingomyelin pathway involves the enzymatic cleavage of sphingomyelin to produce ceramide, a second messenger that serves as a key mediator in the rapid apoptotic response to various cell stressors. Low-linear energy transfer (LET) γ radiation can initiate this pathway, independent of DNA damage, via the cell membrane. Whether short-ranged, high-LET α particles, which are of interest as potent environmental carcinogens, radiotherapies and potential components of dirty bombs, can act through this mechanism to signal apoptosis is unknown. Here we show that irradiation of Jurkat cells with α particles emitted by the ²²⁵Ac-DOTA-anti-CD3 IgG antibody construct results in dose-dependent apoptosis. This apoptosis was significantly reduced by pretreating cells with cholesterol-depleting nystatin, a reagent known to inhibit ceramide signaling by interfering with membrane raft coalescence and ceramide-rich platform generation. The effects of nystatin on α-particle-induced apoptosis were related to disruption of the ceramide pathway and not to microdosimetry alterations, because similar results were obtained after external irradiation of the cells with a broad beam of collimated α particles using a planar ²⁴¹Am source. External irradiation allowed for more precise control of the dosimetry and geometry of the irradiation, independent of antibody binding or cell internalization kinetics. Mechanistically consistent with these findings, Jurkat cells rapidly increased membrane concentrations of ceramide after external irradiation with an average of five α-particle traversals per cell. These data indicate that α particles can activate the sphingomyelin pathway to induce apoptosis. PMID:21631289

  15. Alpha Particles Induce Apoptosis through the Sphingomyelin Pathway

    PubMed Central

    Seideman, Jonathan H.; Stancevic, Branka; Rotolo, Jimmy A.; McDevitt, Michael R.; Howell, Roger W.; Kolesnick, Richard N.; Scheinberg, David A.

    2011-01-01

    The sphingomyelin pathway involves the enzymatic cleavage of sphingomyelin to produce ceramide, a second messenger that serves as a key mediator in the rapid apoptotic response to various cell stressors. Low-linear energy transfer (LET) γ radiation can initiate this pathway, independent of DNA damage, via the cell membrane. Whether short-ranged, high-LET a particles, which are of interest as potent environmental carcinogens, radiotherapies and potential components of dirty bombs, can act through this mechanism to signal apoptosis is unknown. Here we show that irradiation of Jurkat cells with a particles emitted by the 225Ac-DOTA-anti-CD3 IgG antibody construct results in dose-dependent apoptosis. This apoptosis was significantly reduced by pretreating cells with cholesterol-depleting nystatin, a reagent known to inhibit ceramide signaling by interfering with membrane raft coalescence and ceramide-rich platform generation. The effects of nystatin on α-particle-induced apoptosis were related to disruption of the ceramide pathway and not to microdosimetry alterations, because similar results were obtained after external irradiation of the cells with a broad beam of collimated a particles using a planar 241Am source. External irradiation allowed for more precise control of the dosimetry and geometry of the irradiation, independent of antibody binding or cell internalization kinetics. Mechanistically consistent with these findings, Jurkat cells rapidly increased membrane concentrations of ceramide after external irradiation with an average of five α-particle traversals per cell. These data indicate that a particles can activate the sphingomyelin pathway to induce apoptosis. PMID:21631289

  16. Involvement of epigenetics and EMT related miRNA in arsenic induced neoplastic transformation and their potential clinical use

    PubMed Central

    Michailidi, Christina; Hayashi, Masamichi; Datta, Sayantan; Sen, Tanusree; Zenner, Kaitlyn; Oladeru, Oluwadamilola; Brait, Mariana; Izumchenko, Evgeny; Baras, Alexander; VandenBussche, Christopher; Argos, Maria; Bivalacqua, Trinity J; Ahsan, Habibul; Hahn, Noah M.; Netto, George J.; Sidransky, David; Hoque, Mohammad O.

    2015-01-01

    Exposure to toxicants leads to cumulative molecular changes that overtime increase a subject’s risk of developing urothelial carcinoma (UC). To assess the impact of arsenic exposure at a time progressive manner, we developed and characterized a cell culture model and tested a panel of miRNAs in urine samples from arsenic exposed subjects, UC patients and controls. To prepare an in vitro model, we chronically exposed an immortalized normal human bladder cell line (HUC1) to arsenic. Growth of the HUC1 cells was increased in a time dependent manner after arsenic treatment and cellular morphology was changed. In soft agar assay, colonies were observed only in arsenic treated cells and the number of colonies gradually increased with longer periods of treatment. Similarly, invaded cells in invasion assay were observed only in arsenic treated cells. Withdrawal of arsenic treatment for 2.5 months did not reverse the tumorigenic properties of arsenic treated cells. Western blot analysis demonstrated decreased PTEN and increased AKT and mTOR in arsenic treated HUC1 cells. Levels of miR-200a, miR-200b, and miR-200c were down-regulated in arsenic exposed HUC1 cells by quantitative RT-PCR. Furthermore, in human urine, miR-200c and miR-205 were inversely associated with arsenic exposure (P=0.005 and 0.009, respectively). Expression of miR-205 discriminated cancer cases from controls with high sensitivity and specificity (AUC=0.845). Our study suggests that exposure to arsenic rapidly induces a multifaceted dedifferentiation program and miR-205 has potential to be used as a marker of arsenic exposure as well as a maker of early UC detection. PMID:25586904

  17. Effects of microbially induced transformations and shift in bacterial community on arsenic mobility in arsenic-rich deep aquifer sediments.

    PubMed

    Das, Suvendu; Liu, Chia-Chuan; Jean, Jiin-Shuh; Lee, Chuan-Chun; Yang, Huai-Jen

    2016-06-01

    Elevated concentration of arsenic (As) prevailed in deep aquifers of Chianan Plain, Taiwan. Arsenic release in relation to microbially induced transformations and shift in bacterial communities in deep aquifer sediments of Budai, southwestern Taiwan were investigated using microcosm experiments and substrate amendments over 90 days of anaerobic incubation. The results revealed that As reduction was independent of Fe reduction and a modest rate of sedimentary As release into aqueous phase occurred at the expense of the native organic carbon. Addition of lactate resulted in a parallel increase in As(III) (3.7-fold), Fe(II) (6.2-fold) and Mn (3.5 fold) in aqueous phase compared to un-amended slurries and the enrichment of sequences related to mostly Bacillus, Flavisolibacter, and Geobacter spp, suggesting the important role of these bacteria in As enrichment through reductive dissolution of As-bearing Fe and Mn minerals. The increase in phosphate-extractable As in solid phase with concomitant rise in As in aqueous phase over the course of incubation further attested to the importance of reductive dissolution in promoting As release. Furthermore, the increase in arrA gene abundance with addition of labile carbon suggests that dissimilatory As reduction also may contribute to As enrichment in the water of the deep aquifer of Budai. PMID:26897570

  18. EFFECT OF ARSENICALS ON ULTRAVIOLET-RADIATION-INDUCED GROWTH ARREST AND RELATED SIGNALING EVENTS IN HUMAN KERATINOCYTES

    EPA Science Inventory

    The molecular mechanisms mediating arsenic-induced carcinogenesis are not well understood. The role of confounding factors such as ultraviolet radiation (UV), add another level of complexity to the study of arsenic carcinogenesis and the cancer risk assessment to humans. We hypot...

  19. Quantifying arsenic-induced morphological changes in spinach leaves: implications for remote sensing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Arsenic (As) is a widely spread soil contaminant which can be accumulated into plant parts. The ability to detect As in contaminated plants is an important tool to minimize As induced health risks. Remote sensing of plant metal toxicity has been the subject of numerous studies. The spectral proper...

  20. DIETARY FOLATE DEFICIENCY ENHANCES ARSENIC-INDUCED MICRONUCLEUS FORMATION IN MICE

    EPA Science Inventory


    Dietary folate deficiency enhances arsenic-induced micronucleus formation in mice.

    Folate deficiency increases background levels ofDNA damage and can enhance the mutagenicity of chemical agents. Duplicate experiments were performed to investigate the effect of dietary...

  1. CHEMOSENSITIZATION BY A NON-APOPTOGENIC HEAT SHOCK PROTEIN 70-BINDING APOPTOSIS INDUCING FACTOR MUTANT

    EPA Science Inventory

    Chemosensitization by a non-apoptogenic heat shock protein 70-binding apoptosis inducing factor mutant

    Abstract
    HSP70 inhibits apoptosis by neutralizing the caspase activator Apaf-1 and by interacting with apoptosis inducing factor (AIF), a mitochondrial flavoprotein wh...

  2. Oxidative Stress Mediates Radiation Lung Injury by Inducing Apoptosis

    SciTech Connect

    Zhang Yu; Zhang Xiuwu; Rabbani, Zahid N.; Jackson, Isabel L.; Vujaskovic, Zeljko

    2012-06-01

    Purpose: Apoptosis in irradiated normal lung tissue has been observed several weeks after radiation. However, the signaling pathway propagating cell death after radiation remains unknown. Methods and Materials: C57BL/6J mice were irradiated with 15 Gy to the whole thorax. Pro-apoptotic signaling was evaluated 6 weeks after radiation with or without administration of AEOL10150, a potent catalytic scavenger of reactive oxygen and nitrogen species. Results: Apoptosis was observed primarily in type I and type II pneumocytes and endothelium. Apoptosis correlated with increased PTEN expression, inhibition of downstream PI3K/AKT signaling, and increased p53 and Bax protein levels. Transforming growth factor-{beta}1, Nox4, and oxidative stress were also increased 6 weeks after radiation. Therapeutic administration of AEOL10150 suppressed pro-apoptotic signaling and dramatically reduced the number of apoptotic cells. Conclusion: Increased PTEN signaling after radiation results in apoptosis of lung parenchymal cells. We hypothesize that upregulation of PTEN is influenced by Nox4-derived oxidative stress. To our knowledge, this is the first study to highlight the role of PTEN in radiation-induced pulmonary toxicity.

  3. The risk of arsenic induced skin lesions in Bangladeshi men and women is affected by arsenic metabolism and the age at first exposure

    SciTech Connect

    Lindberg, Anna-Lena; Rahman, Mahfuzar; Persson, Lars-Ake; Vahter, Marie

    2008-07-01

    It is known that a high fraction of methylarsonate (MA) in urine is a risk modifying factor for several arsenic induced health effects, including skin lesions, and that men are more susceptible for developing skin lesions than women. Thus, we aimed at elucidating the interaction between gender and arsenic metabolism for the risk of developing skin lesions. This study is part of a population-based case-referent study concerning the risk for skin lesions in relation to arsenic exposure via drinking water carried out in Matlab, a rural area 53km south-east of Dhaka, Bangladesh. We randomly selected 526 from 1579 referents and all 504 cases for analysis of arsenic metabolites in urine using HPLC coupled to inductively coupled plasma mass spectrometry (HPLC-HG-ICPMS). The present study confirm previous studies, with the risk for skin lesions being almost three times higher in the highest tertile of %MA (adjusted OR 2.8, 95% CI: 1.9-4.2, p < 0.001) compared to the lowest tertile. The present study is the first to show that the well documented higher risk for men to develop arsenic-related skin lesions compared to women is mainly explained by the less efficient methylation of arsenic, as defined by a higher fraction of MA and lower fraction of DMA in the urine, among men. Our previously documented lower risk for skin lesions in individuals exposed since infancy, or before, was found to be independent of the observed arsenic methylation efficiency. Thus, it can be speculated that this is due to a programming effect of arsenic in utero.

  4. Atorvastatin acts synergistically with N-acetyl cysteine to provide therapeutic advantage against Fas-activated erythrocyte apoptosis during chronic arsenic exposure in rats

    SciTech Connect

    Biswas, Debabrata; Sen, Gargi; Sarkar, Avik; Biswas, Tuli

    2011-01-01

    Arsenic is an environmental toxicant that reduces the lifespan of circulating erythrocytes during chronic exposure. Our previous studies had indicated involvement of hypercholesterolemia and reactive oxygen species (ROS) in arsenic-induced apoptotic death of erythrocytes. In this study, we have shown an effective recovery from arsenic-induced death signaling in erythrocytes in response to treatment with atorvastatin (ATV) and N-acetyl cysteine (NAC) in rats. Our results emphasized on the importance of cholesterol in the promotion of ROS-mediated Fas signaling in red cells. Arsenic-induced activation of caspase 3 was associated with phosphatidylserine exposure on the cell surface and microvesiculation of erythrocyte membrane. Administration of NAC in combination with ATV, proved to be more effective than either of the drugs alone towards the rectification of arsenic-mediated disorganization of membrane structural integrity, and this could be linked with decreased ROS accumulation through reduced glutathione (GSH) repletion along with cholesterol depletion. Moreover, activation of caspase 3 was capable of promoting aggregation of band 3 with subsequent binding of autologous IgG and opsonization by C3b that led to phagocytosis of the exposed cells by the macrophages. NAC-ATV treatment successfully amended these events and restored lifespan of erythrocytes from the exposed animals almost to the control level. This work helped us to identify intracellular membrane cholesterol enrichment and GSH depletion as the key regulatory points in arsenic-mediated erythrocyte destruction and suggested a therapeutic strategy against Fas-activated cell death related to enhanced cholesterol and accumulation of ROS.

  5. Arsenic induces sustained impairment of skeletal muscle and muscle progenitor cell ultrastructure and bioenergetics.

    PubMed

    Ambrosio, Fabrisia; Brown, Elke; Stolz, Donna; Ferrari, Ricardo; Goodpaster, Bret; Deasy, Bridget; Distefano, Giovanna; Roperti, Alexandra; Cheikhi, Amin; Garciafigueroa, Yesica; Barchowsky, Aaron

    2014-09-01

    Over 4 million individuals in the United States, and over 140 million individuals worldwide, are exposed daily to arsenic-contaminated drinking water. Human exposures can range from below the current limit of 10 μg/L to over 1mg/L, with 100 μg/L promoting disease in a large portion of those exposed. Although increased attention has recently been paid to myopathy following arsenic exposure, the pathogenic mechanisms underlying clinical symptoms remain poorly understood. This study tested the hypothesis that arsenic induces lasting muscle mitochondrial dysfunction and impairs metabolism. Compared to nonexposed controls, mice exposed to drinking water containing 100 μg/L arsenite for 5 weeks demonstrated impaired muscle function, mitochondrial myopathy, and altered oxygen consumption that were concomitant with increased mitochondrial fusion gene transcription. There were no differences in the levels of inorganic arsenic or its monomethyl and dimethyl metabolites between controls and exposed muscles, confirming that arsenic does not accumulate in muscle. Nevertheless, muscle progenitor cells isolated from exposed mice recapitulated the aberrant myofiber phenotype and were more resistant to oxidative stress, generated more reactive oxygen species, and displayed autophagic mitochondrial morphology, compared to cells isolated from nonexposed mice. These pathological changes from a possible maladaptive oxidative stress response provide insight into declines in muscle functioning caused by exposure to this common environmental contaminant. PMID:24960579

  6. Role of berberine against arsenic induced oxidative damage in isolated rat liver mitochondria.

    PubMed

    Khodayar, Mohammad Javad; Javadipour, Mansoureh; Keshtzar, Elham; Rezaei, Mohsen

    2016-03-01

    The aim of the present study was to assess the protective role of berberine against toxicity induced by arsenic in mitochondria from liver of rat. The level of reactive oxygen species and mitochondrial membrane potential changes were evaluated spectrofluorometrically. 20, 40 and 100 μM arsenic concentration increased ROS level approximately by 13.5, 21.3 and 29 %. However, when pretreated mitochondria with berberine (10, 25, 50 μM) were exposed to arsenic (20, 40 and 100 μM), ROS production diminished. Also, for all arsenic concentration mitochondrial membrane damage was detected to be 2.5, 4.8 and 7.26 % respectively. Pretreatment with berberine even at highest concentration (50μM) was not able to retain membrane potential as compared to control. These results showed that mitochondria were significantly affected when exposed to arsenic, forcedly directed toward excess ROS production and mitochondrial membrane disruption. Pretreatment with berberine, reduced ROS generation but did not restore mitochondrial membrane integrity. PMID:27097449

  7. Dracorhodin perchlorate induces the apoptosis of glioma cells.

    PubMed

    Chen, Xin; Luo, Junjie; Meng, Linghu; Pan, Taifeng; Zhao, Binjie; Tang, Zhen-Gang; Dai, Yongjian

    2016-04-01

    Dracorhodin perchlorate (Dp), a synthetic analogue of the antimicrobial anthocyanin red pigment, has recently been shown to induce apoptotic cell death in various types of cancer cells. Yet, the inhibitory effect of Dp on human glioma cells remains uninvestigated. Therefore, in the present study, 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry were used to detect cell viability and cell cycle progression in glioma U87MG and T98G cells, respectively. Annexin V-FITC/propidium iodide double staining and JC-1 staining were separately applied to determine cellular apoptosis and mitochondrial membrane potential damage in the cells. The expression levels of associated proteins involved in cell cycle progression and apoptosis were measured by western blotting. The activities of caspase‑9/-3 were determined by Caspase-Glo-9/3 assay. The results indicated that Dp treatment significantly inhibited cell proliferation in a dose- and time-dependent manner, and blocked cell cycle progression at the G1/S phase in the U87MG and T98G cells via the upregulation of p53 and p21 protein expression, and simultaneous downregulation of Cdc25A, Cdc2 and P-Cdc2 protein expression. Additionally, Dp treatment led to the loss of cellular mitochondrial membrane potential, and the release of cytochrome c, and strongly induced the occurence of apoptosis. Increased expression levels of Bim and Bax protein and the downregulated expression of Bcl-2 protein were observed. Caspase-9/-3 were activated and their activities were elevated after Dp treatment. These findings indicate that Dp inhibits cell proliferation, induces cell cycle arrest and apoptosis in glioma cells, and is a possible candidate for glioma treatment. PMID:26846469

  8. Inhibitor of Apoptosis Proteins Physically Interact with and Block Apoptosis Induced by Drosophila Proteins HID and GRIM

    PubMed Central

    Vucic, Domagoj; Kaiser, William J.; Miller, Lois K.

    1998-01-01

    Reaper (RPR), HID, and GRIM activate apoptosis in cells programmed to die during Drosophila development. We have previously shown that transient overexpression of RPR in the lepidopteran SF-21 cell line induces apoptosis and that members of the inhibitor of apoptosis (IAP) family of antiapoptotic proteins can inhibit RPR-induced apoptosis and physically interact with RPR through their BIR motifs (D. Vucic, W. J. Kaiser, A. J. Harvey, and L. K. Miller, Proc. Natl. Acad. Sci. USA 94:10183–10188, 1997). In this study, we found that transient overexpression of HID and GRIM also induced apoptosis in the SF-21 cell line. Baculovirus and Drosophila IAPs blocked HID- and GRIM-induced apoptosis and also physically interacted with them through the BIR motifs of the IAPs. The region of sequence similarity shared by RPR, HID, and GRIM, the N-terminal 14 amino acids of each protein, was required for the induction of apoptosis by HID and its binding to IAPs. When stably overexpressed by fusion to an unrelated, nonapoptotic polypeptide, the N-terminal 37 amino acids of HID and GRIM were sufficient to induce apoptosis and confer IAP binding activity. However, GRIM was more complex than HID since the C-terminal 124 amino acids of GRIM retained apoptosis-inducing and IAP binding activity, suggesting the presence of two independent apoptotic motifs within GRIM. Coexpression of IAPs with HID stabilized HID levels and resulted in the accumulation of HID in punctate perinuclear locations which coincided with IAP localization. The physical interaction of IAPs with RPR, HID, and GRIM provides a common molecular mechanism for IAP inhibition of these Drosophila proapoptotic proteins. PMID:9584170

  9. Select forms of tumor cell apoptosis induce dendritic cell maturation.

    PubMed

    Demaria, Sandra; Santori, Fabio R; Ng, Bruce; Liebes, Leonard; Formenti, Silvia C; Vukmanovic, Stanislav

    2005-03-01

    Dendritic cells (DC) play a crucial role in initiating immune responses to tumors. DC can efficiently present antigens from apoptotic tumor cells, but apoptotic cells are thought to lack the inflammatory signals required to induce DC maturation. Here, we show that apoptosis of 67NR mouse carcinoma cells via the Fas (CD95) pathway or induced by the anticancer drug bortezomib (PS-341) but not by ultraviolet irradiation is associated with the production of maturation signals for DC. These data have important implications for the effects of chemotherapy on antitumor immunity in solid and hematologic malignancies. PMID:15569694

  10. Inhibition of TLR8 mediated signaling promotes BCG induced apoptosis in THP-1 cells.

    PubMed

    Tang, Jun; Zhan, Lingjun; Qin, Chuan

    2016-04-01

    Apoptosis was considered as one of the important host defense mechanisms against mycobacteria infection. In macrophage, the main target cell of Mycobacterium tuberculosis, apoptosis after infection could help kill the bacillus inside and process the antigens for further presentation and proper immune response. Here, we identified a role of TLR8 during the apoptosis induced by Bacillus Calmette Guérin (BCG) infection in THP-1 cells. Knockdown TLR8 further increased the apoptosis induced by BCG infection, and this enhanced apoptosis was caspase-dependent. During this process, Erk1/2, JNK and NFκB pathways were negatively affected and contributed to the enhanced apoptosis. PMID:26657720

  11. Raman spectrum reveals the cell cycle arrest of Triptolide-induced leukemic T-lymphocytes apoptosis

    NASA Astrophysics Data System (ADS)

    Zhang, Daosen; Feng, Yanyan; Zhang, Qinnan; Su, Xin; Lu, Xiaoxu; Liu, Shengde; Zhong, Liyun

    2015-04-01

    Triptolide (TPL), a traditional Chinese medicine extract, possesses anti-inflammatory and anti-tumor properties. Though some research results have implicated that Triptolide (TPL) can be utilized in the treatment of leukemia, it remains controversial about the mechanism of TPL-induced leukemic T-lymphocytes apoptosis. In this study, combining Raman spectroscopic data, principal component analysis (PCA) and atomic force microscopy (AFM) imaging, both the biochemical changes and morphological changes during TPL-induced cell apoptosis were presented. In contrast, the corresponding data during Daunorubicin (DNR)-induced cell apoptosis was also exhibited. The obtained results showed that Raman spectral changes during TPL-induced cell apoptosis were greatly different from DNR-induced cell apoptosis in the early stage of apoptosis but revealed the high similarity in the late stage of apoptosis. Moreover, above Raman spectral changes were respectively consistent with the morphological changes of different stages during TPL-induced apoptosis or DNR-induced apoptosis, including membrane shrinkage and blebbing, chromatin condensation and the formation of apoptotic bodies. Importantly, it was found that Raman spectral changes with TPL-induced apoptosis or DNR-induced apoptosis were respectively related with the cell cycle G1 phase arrest or G1 and S phase arrest.

  12. Chronic inorganic arsenic exposure in vitro induces a cancer cell phenotype in human peripheral lung epithelial cells

    SciTech Connect

    Person, Rachel J.; Olive Ngalame, Ntube N.; Makia, Ngome L.; Bell, Matthew W.; Waalkes, Michael P.; Tokar, Erik J.

    2015-07-01

    Inorganic arsenic is a human lung carcinogen. We studied the ability of chronic inorganic arsenic (2 μM; as sodium arsenite) exposure to induce a cancer phenotype in the immortalized, non-tumorigenic human lung peripheral epithelial cell line, HPL-1D. After 38 weeks of continuous arsenic exposure, secreted matrix metalloproteinase-2 (MMP2) activity increased to over 200% of control, levels linked to arsenic-induced cancer phenotypes in other cell lines. The invasive capacity of these chronic arsenic-treated lung epithelial (CATLE) cells increased to 320% of control and colony formation increased to 280% of control. CATLE cells showed enhanced proliferation in serum-free media indicative of autonomous growth. Compared to control cells, CATLE cells showed reduced protein expression of the tumor suppressor gene PTEN (decreased to 26% of control) and the putative tumor suppressor gene SLC38A3 (14% of control). Morphological evidence of epithelial-to-mesenchymal transition (EMT) occurred in CATLE cells together with appropriate changes in expression of the EMT markers vimentin (VIM; increased to 300% of control) and e-cadherin (CDH1; decreased to 16% of control). EMT is common in carcinogenic transformation of epithelial cells. CATLE cells showed increased KRAS (291%), ERK1/2 (274%), phosphorylated ERK (p-ERK; 152%), and phosphorylated AKT1 (p-AKT1; 170%) protein expression. Increased transcript expression of metallothioneins, MT1A and MT2A and the stress response genes HMOX1 (690%) and HIF1A (247%) occurred in CATLE cells possibly in adaptation to chronic arsenic exposure. Thus, arsenic induced multiple cancer cell characteristics in human peripheral lung epithelial cells. This model may be useful to assess mechanisms of arsenic-induced lung cancer. - Highlights: • Chronic arsenic exposure transforms a human peripheral lung epithelia cell line. • Cells acquire characteristics in common with human lung adenocarcinoma cells. • These transformed cells provide a

  13. Erythropoietin protects cardiac myocytes against anthracycline-induced apoptosis

    SciTech Connect

    Fu Ping; Arcasoy, Murat O. . E-mail: arcas001@mc.duke.edu

    2007-03-09

    The cardiotoxic adverse effects of anthracycline antibiotics limit their therapeutic utility as essential components of chemotherapy regimens for hematologic and solid malignancies. Here we show that the hematopoietic cytokine erythropoietin attenuates doxorubicin-induced apoptosis of primary neonatal rat ventricular cardiomyocytes in a dose-dependent manner. Erythropoietin treatment induced rapid, time-dependent phosphorylation of MAP kinases (MAPK) Erk1/2 and the phosphatidylinositol 3-kinase substrate Akt. Treatment of cardiomyocytes with inhibitors of phosphatidylinositol 3-kinase (LY294002) or Akt (Akti-1/2) abolished the protective effect of erythropoietin, whereas treatment with MAPK kinase (MEK1) inhibitor U0126 did not. Erythropoietin also induced the phosphorylation of GSK-3{beta}, a downstream target of PI3K-Akt. Because phosphorylation is known to inactivate GSK-3{beta}, we investigated whether GSK-3{beta} inhibition is cardioprotective. We found that GSK-3{beta} inhibitors SB216763 or lithium chloride blocked doxorubicin-induced cardiomyocyte apoptosis in a manner similar to erythropoietin, suggesting that GSK-3{beta} inhibition is involved in erythropoietin-mediated cardioprotection. Erythropoietin may serve as a novel cardioprotective agent against anthracycline-induced cardiotoxicity.

  14. Tamoxifen Induces Apoptosis of Leishmania major Promastigotes in Vitro

    PubMed Central

    Doroodgar, Masoud; Delavari, Mahdi; Doroodgar, Moein; Abbasi, Ali; Taherian, Ali Akbar; Doroodgar, Abbas

    2016-01-01

    Tamoxifen is an antagonist of the estrogen receptor and currently used for the treatment of breast cancer. The current treatment of cutaneous leishmaniasis with pentavalent antimony compounds is not satisfactory. Therefore, in this study, due to its antileishmanial activity, effects of tamoxifen on the growth of promastigotes and amastigotes of Leishmania major Iranian strain were evaluated in vitro. Promastigotes and amastigotes were treated with different concentrations (1, 5, 10, 20, and 50 μg/ml) and time periods (24, 48, and 72 hr) of tamoxifen. After tamoxifen treatment, MTT assay (3-[4,5-dimethylthiazol-2-yl]-2,5 biphenyl tetrazolium bromide assay) was used to determine the percentage of live parasites and Graph Pad Prism software to calculate IC50. Flow cytometry was applied to investigate the induction of tamoxifen-induced apoptosis in promastigotes. The half maximal inhibitory concentration (IC50) of tamoxifen on promastigotes was 2.6 μg/ml after 24 hr treatment. Flow cytometry analysis showed that tamoxifen induced early and late apoptosis in Leishmania promastigotes. While after 48 hr in control group the apoptosis was 2.0%, the 50 µg/L concentration of tamoxifen increased it to 59.7%. Based on the in vitro antileishmanial effect, tamoxifen might be used for leishmaniasis treatment; however, further researches on in vivo effects of tamoxifen in animal models are needed. PMID:26951973

  15. Therapeutic effects of Moringa oleifera on arsenic-induced toxicity in rats.

    PubMed

    Gupta, Richa; Kannan, Gurusamy M; Sharma, Mamta; S Flora, Swaran J

    2005-11-01

    the seed powder of M. oleifera has significant role in protecting animals from arsenic-induced oxidative stress and in the depletion of arsenic concentration. Further studies thus can be recommended for determining the effect of co-administrating seed powder of M. oleifera during chelation therapy with a thiol chelator. PMID:21783626

  16. Apoptosis induced by granzyme B-glycosaminoglycan complexes: implications for granule-mediated apoptosis in vivo.

    PubMed

    Galvin, J P; Spaeny-Dekking, L H; Wang, B; Seth, P; Hack, C E; Froelich, C J

    1999-05-01

    Lymphocyte granule-mediated apoptosis occurs by perforin-mediated intracellular delivery of granule-associated serine proteases (granzymes). A granule-associated proteoglycan, namely serglycin, that contains chondroitin 4-sulfate (CS) glycosaminoglycans is present in the granules of cytotoxic cells. Serglycin acts as scaffold for packaging the positively charged granzymes and probably chaperones the proteases secreted extracellularly. To learn how the interaction of granzyme B (GrB) with serglycin might influence the apoptotic potential of this proteases, we have evaluated a model system where desalted CS is combined with isolated human granzyme. CS-GrB complexes were very stable, remaining undissociated in salt concentrations upwards to 500 mM (pH 7.4). On the basis of a capture enzyme immunoassay that accurately detects GrB, equivalent amounts of active free and CS-GrB, delivered by perforin or adenovirus, efficiently induced apoptosis in Jurkat cells and produced a similar time-dependent increase in caspase-3-like activity. CS-GrB processed isolated caspases-3 and -7 less efficiently than free granzyme. However, when added to cytosolic extracts, rates of processing were nearly equivalent for the two forms, suggesting cationic GrB may nonspecifically bind cytosolic proteins, leading to reduce proteolytic activity. Finally, GrB was found to be exocytosed from lymphocyte-activated killer cells as a neutral, high macromolecular weight complex, which possessed apoptotic activity. Collectively, the results indicate that neutral, high m.w. GrB has the capacity to induce cell death and will be useful to study the mechanism of cytotoxic cell-mediated apoptosis in vitro. PMID:10228010

  17. Roscovitine ameliorates endotoxin-induced uveitis through neutrophil apoptosis.

    PubMed

    Jiang, Zhao-Xin; Qiu, Suo; Lou, Bing-Sheng; Yang, Yao; Wang, Wen-Cong; Lin, Xiao-Feng

    2016-08-01

    Neutrophils have been recognized as critical response cells during the pathogenesis of endotoxin‑induced uveitis (EIU). Apoptosis of neutrophils induced by roscovitine has previously been demonstrated to ameliorate inflammation in several in vivo models. The present study aimed to assess whether roscovitine ameliorates EIU. EIU was induced in female C57BL/6 mice by a single intravitreal injection of lipopolysaccharide (LPS; 250 ng). The mice were divided into three groups as follows: LPS alone, LPS plus vehicle, LPS plus roscovitine (50 mg/kg). The mice were euthanized 12, 24, 48 and 72 h after LPS‑induced uveitis. Accumulation of inflammatory cells in the vitreous body was confirmed by immunohistochemistry, and quantified following hematoxylin and eosin staining. Terminal deoxynucleotidyl transferase dUTP nick‑end labeling was performed to detect of apoptotic cells. The mRNA levels of inflammatory cytokines were analyzed by reverse transcription‑quantitative polymerase chain reaction and the changes in protein levels were analyzed by western blotting. Inflammatory cells accumulated in the vitreous near the optic nerve head and the quantity peaked at 24 h after LPS injection. Immunohistochemistry revealed that the majority of the inflammatory cells were neutrophils. The number of infiltrating cells was similar in the LPS and LPS plus vehicle groups, while there were significantly less in the roscovitine group at 24 h. Apoptosis of neutrophils was observed between 12 and 48 h after roscovitine injection, while no apoptosis was observed in the other groups. The mRNA expression levels of GMCSF, CINC‑1 and ICAM‑1 peaked at 12 h after LPS injection, and decreased to normal levels at 72 h. This trend in mRNA expression was similar in the LPS and LPS plus vehicle groups; however, the expression levels decreased more quickly in the roscovitine group at 24 and 48 h. Following roscovitine administration, upregulated cleaved caspase 3 expression levels

  18. Roscovitine ameliorates endotoxin-induced uveitis through neutrophil apoptosis

    PubMed Central

    Jiang, Zhao-Xin; Qiu, Suo; Lou, Bing-Sheng; Yang, Yao; Wang, Wen-Cong; Lin, Xiao-Feng

    2016-01-01

    Neutrophils have been recognized as critical response cells during the pathogenesis of endotoxin-induced uveitis (EIU). Apoptosis of neutrophils induced by roscovitine has previously been demonstrated to ameliorate inflammation in several in vivo models. The present study aimed to assess whether roscovitine ameliorates EIU. EIU was induced in female C57BL/6 mice by a single intravitreal injection of lipopolysaccharide (LPS; 250 ng). The mice were divided into three groups as follows: LPS alone, LPS plus vehicle, LPS plus roscovitine (50 mg/kg). The mice were euthanized 12, 24, 48 and 72 h after LPS-induced uveitis. Accumulation of inflammatory cells in the vitreous body was confirmed by immunohistochemistry, and quantified following hematoxylin and eosin staining. Terminal deoxynucleotidyl transferase dUTP nick-end labeling was performed to detect of apoptotic cells. The mRNA levels of inflammatory cytokines were analyzed by reverse transcription-quantitative polymerase chain reaction and the changes in protein levels were analyzed by western blotting. Inflammatory cells accumulated in the vitreous near the optic nerve head and the quantity peaked at 24 h after LPS injection. Immunohistochemistry revealed that the majority of the inflammatory cells were neutrophils. The number of infiltrating cells was similar in the LPS and LPS plus vehicle groups, while there were significantly less in the roscovitine group at 24 h. Apoptosis of neutrophils was observed between 12 and 48 h after roscovitine injection, while no apoptosis was observed in the other groups. The mRNA expression levels of GMCSF, CINC-1 and ICAM-1 peaked at 12 h after LPS injection, and decreased to normal levels at 72 h. This trend in mRNA expression was similar in the LPS and LPS plus vehicle groups; however, the expression levels decreased more quickly in the roscovitine group at 24 and 48 h. Following roscovitine administration, upregulated cleaved caspase 3 expression levels and downregulated Mcl-1

  19. Apoptosis-induced mitochondrial dysfunction causes cytoplasmic lipid droplet formation.

    PubMed

    Boren, J; Brindle, K M

    2012-09-01

    A characteristic of apoptosis is the rapid accumulation of cytoplasmic lipid droplets, which are composed largely of neutral lipids. The proton signals from these lipids have been used for the non-invasive detection of cell death using magnetic resonance spectroscopy. We show here that despite an apoptosis-induced decrease in the levels and activities of enzymes involved in lipogenesis, which occurs downstream of p53 activation and inhibition of the mTOR signaling pathway, the increase in lipid accumulation is due to increased de novo lipid synthesis. This results from inhibition of mitochondrial fatty acid β-oxidation, which coupled with an increase in acyl-CoA synthetase activity, diverts fatty acids away from oxidation and into lipid synthesis. The inhibition of fatty acid oxidation can be explained by a rapid rise in mitochondrial membrane potential and an attendant increase in the levels of reactive oxygen species. PMID:22460322

  20. Ceramide-Induced Apoptosis in Renal Tubular Cells: A Role of Mitochondria and Sphingosine-1-Phoshate

    PubMed Central

    Ueda, Norishi

    2015-01-01

    Ceramide is synthesized upon stimuli, and induces apoptosis in renal tubular cells (RTCs). Sphingosine-1 phosphate (S1P) functions as a survival factor. Thus, the balance of ceramide/S1P determines ceramide-induced apoptosis. Mitochondria play a key role for ceramide-induced apoptosis by altered mitochondrial outer membrane permeability (MOMP). Ceramide enhances oligomerization of pro-apoptotic Bcl-2 family proteins, ceramide channel, and reduces anti-apoptotic Bcl-2 proteins in the MOM. This process alters MOMP, resulting in generation of reactive oxygen species (ROS), cytochrome C release into the cytosol, caspase activation, and apoptosis. Ceramide regulates apoptosis through mitogen-activated protein kinases (MAPKs)-dependent and -independent pathways. Conversely, MAPKs alter ceramide generation by regulating the enzymes involving ceramide metabolism, affecting ceramide-induced apoptosis. Crosstalk between Bcl-2 family proteins, ROS, and many signaling pathways regulates ceramide-induced apoptosis. Growth factors rescue ceramide-induced apoptosis by regulating the enzymes involving ceramide metabolism, S1P, and signaling pathways including MAPKs. This article reviews evidence supporting a role of ceramide for apoptosis and discusses a role of mitochondria, including MOMP, Bcl-2 family proteins, ROS, and signaling pathways, and crosstalk between these factors in the regulation of ceramide-induced apoptosis of RTCs. A balancing role between ceramide and S1P and the strategy for preventing ceramide-induced apoptosis by growth factors are also discussed. PMID:25751724

  1. Arsenic-induced intensity oscillations in reflection high-energy electron diffraction measurements. [during MBE of GaAs and InAs

    NASA Technical Reports Server (NTRS)

    Lewis, B. F.; Fernandez, R.; Grunthaner, F. J.; Madhukar, A.

    1986-01-01

    A technique of arsenic-induced RHEED intensity oscillations has been used to accurately measure arsenic incorporation rates as a function of substrate temperature during the homoepitaxial growths of both GaAs and InAs by molecular beam epitaxy (MBE). Measurements were made at growth temperatures from 350 to 650 C and at arsenic fluxes of 0.1 to 10.0 monolayer/s. The method measures only the arsenic actually incorporated into the growing film and does not include the arsenic lost in splitting the arsenic tetramers or lost by evaporation from the sample.

  2. Cimetidine induces apoptosis of human salivary gland tumor cells.

    PubMed

    Fukuda, Masakatsu; Tanaka, Shin; Suzuki, Seiji; Kusama, Kaoru; Kaneko, Tadayoshi; Sakashita, Hideaki

    2007-03-01

    It has been reported that cimetidine, a histamine type-2 receptor (H2R) antagonist, inhibits the growth of glandular tumors such as colorectal cancer. However, its effects against salivary gland tumors are still unknown. We demonstrated previously that human salivary gland tumor (HSG) cells spontaneously express the neural cell adhesion molecule (NCAM) and also that HSG cell proliferation could be controlled via a homophilic (NCAM-NCAM) binding mechanism and that NCAM may be associated with perineural invasion by malignant salivary gland tumors. In the present study, we investigated the effects of cimetidine via the expression of NCAM on tumor growth and perineural/neural invasion in salivary gland tumor cells. Expression of both NCAM mRNA and protein was found to decrease in a dose-dependent manner upon treatment with cimetidine for 24 h. The MTT assay and confocal laser microscopy clearly showed that HSG cells underwent apoptosis after treatment with cimetidine. Activation of caspases 3, 7, 8 and 9 was observed in HSG cells after cimetidine treatment, thus confirming that the apoptosis was induced by the activated caspases. Apaf-1 activity was also detected in HSG cells in a dose-dependent manner after treatment with cimetidine. We also found that the cimetidine-mediated down-regulation of NCAM expression in HSG cells did not occur via blocking of the histamine receptor, even though H2R expression was observed on HSG cells, as two other H2R antagonists, famotidine and ranitidine, did not show similar effects. We demonstrated for the first time that cimetidine can induce significant apoptosis of salivary gland tumor cells, which express NCAM, at least in part by down-regulation of NCAM expression on the cells. These findings suggest that the growth, development and perineural/neural invasion of salivary gland tumor cells can be blocked by cimetidine administration through down-regulation of NCAM expression, as well as induction of apoptosis. PMID:17273750

  3. AIRE-induced apoptosis is associated with nuclear translocation of stress sensor protein GAPDH

    SciTech Connect

    Liiv, Ingrid; Haljasorg, Uku; Kisand, Kai; Maslovskaja, Julia; Laan, Martti; Peterson, Paert

    2012-06-22

    Highlights: Black-Right-Pointing-Pointer AIRE induces apoptosis in epithelial cells. Black-Right-Pointing-Pointer CARD domain of AIRE is sufficient for apoptosis induction. Black-Right-Pointing-Pointer AIRE induced apoptosis involves GAPDH translocation to the nuclei. Black-Right-Pointing-Pointer Deprenyl inhibits AIRE induced apoptosis. -- Abstract: AIRE (Autoimmune Regulator) has a central role in the transcriptional regulation of self-antigens in medullary thymic epithelial cells, which is necessary for negative selection of autoreactive T cells. Recent data have shown that AIRE can also induce apoptosis, which may be linked to cross-presentation of these self-antigens. Here we studied AIRE-induced apoptosis using AIRE over-expression in a thymic epithelial cell line as well as doxycycline-inducible HEK293 cells. We show that the HSR/CARD domain in AIRE together with a nuclear localization signal is sufficient to induce apoptosis. In the nuclei of AIRE-positive cells, we also found an increased accumulation of a glycolytic enzyme, glyceraldehyde-3-phosphate (GAPDH) reflecting cellular stress and apoptosis. Additionally, AIRE-induced apoptosis was inhibited with an anti-apoptotic agent deprenyl that blocks GAPDH nitrosylation and nuclear translocation. We propose that the AIRE-induced apoptosis pathway is associated with GAPDH nuclear translocation and induction of NO-induced cellular stress in AIRE-expressing cells.

  4. Well Water Arsenic Exposure, Arsenic Induced Skin-Lesions and Self-Reported Morbidity in Inner Mongolia

    PubMed Central

    Xia, Yajuan; Wade, Timothy J.; Wu, Kegong; Li, Yanhong; Ning, Zhixiong; Le, X Chris; He, Xingzhou; Chen, Binfei; Feng, Yong; Mumford, Judy L.

    2009-01-01

    Residents of the Bayingnormen region of Inner Mongolia have been exposed to arsenic-contaminated well water for over 20 years, but relatively few studies have investigated health effects in this region. We surveyed one village to document exposure to arsenic and assess the prevalence of arsenic-associated skin lesions and self-reported morbidity. Five-percent (632) of the 12,334 residents surveyed had skin lesions characteristics of arsenic exposure. Skin lesions were strongly associated with well water arsenic and there was an elevated prevalence among residents with water arsenic exposures as low as 5 μg/L-10 μg/L. The presence of skin lesions was also associated with self-reported cardiovascular disease. PMID:19440430

  5. Oxidative DNA damage of peripheral blood polymorphonuclear leukocytes, selectively induced by chronic arsenic exposure, is associated with extent of arsenic-related skin lesions

    SciTech Connect

    Pei, Qiuling; Ma, Ning; Zhang, Jing; Xu, Wenchao; Li, Yong; Ma, Zhifeng; Li, Yunyun; Tian, Fengjie; Zhang, Wenping; Mu, Jinjun; Li, Yuanfei; Wang, Dongxing; Liu, Haifang; Yang, Mimi; Ma, Caifeng; Yun, Fen

    2013-01-01

    There is increasing evidence that oxidative stress is an important risk factor for arsenic-related diseases. Peripheral blood leukocytes constitute an important defense against microorganisms or pathogens, while the research on the impact of chronic arsenic exposure on peripheral blood leukocytes is much more limited, especially at low level arsenic exposure. The purpose of the present study was to explore whether chronic arsenic exposure affects oxidative stress of peripheral blood leukocytes and possible linkages between oxidative stress and arsenic-induced skin lesions. 75 male inhabitants recruited from an As-endemic region of China were investigated in the present study. The classification of arsenicosis was based on the degree of skin lesions. Arsenic levels were measured in drinking water and urine by Atomic Fluorescence Spectroscopy. Urinary 8-hydroxy-2′-deoxyguanosine (8-OHdG) was tested by Enzyme-Linked Immunosorbent Assay. 8-OHdG of peripheral blood leukocytes was evaluated using immunocytochemical staining. 8-OHdG-positive reactions were only present in polymorphonuclear leukocytes (PMNs), but not in monocytes (MNs). The 8-OHdG staining of PMN cytoplasm was observed in all investigated populations, while the 8-OHdG staining of PMN nuclei was frequently found along with the elevated amounts of cell debris in individuals with skin lesion. Urinary arsenic levels were increased in the severe skin lesion group compared with the normal group. No relationship was observed between drinking water arsenic or urine 8-OHdG and the degree of skin lesions. These findings indicated that the target and persistent oxidative stress in peripheral blood PMNs may be employed as a sensitive biomarker directly to assess adverse health effects caused by chronic exposure to lower levels of arsenic. -- Highlights: ► Male inhabitants were investigated from an As-endemic region of China. ► 8-OHdG-positive reactions were only present in polymorphonuclear leukocytes (PMNs).

  6. Tetranectin gene deletion induces Parkinson's disease by enhancing neuronal apoptosis.

    PubMed

    Chen, Zhifeng; Wang, Ersong; Hu, Rong; Sun, Yu; Zhang, Lei; Jiang, Jue; Zhang, Ying; Jiang, Hong

    Parkinson's disease (PD) is a chronic neurodegenerative disorder characterized by the progressive degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNpc). We previously identified tetranectin (TET) as a potential biomarker for PD whose expression is downregulated in the cerebrospinal fluid of PD patients. In the present study, we investigate the role of TET in neurodegeneration in vitro and in vivo. Our results showed that siRNA knockdown of TET decreased cell viability and the number of tyrosine hydroxylase (TH) positive cells, whereas it increased caspase-3 activity and the Bax/Bcl-2 ratio in cultured primary dopaminergic neurons. Overexpression of TET protected dopaminergic neurons against neuronal apoptosis in 1-methyl-4-phenylpyridinium cell culture model in vitro. In TET knockdown mouse model of PD, TET gene deletion decreased the number of TH positive cells in the SNpc, induced apoptosis via the p53/Bax pathway, and significantly impaired the motor behavior of transgenic mice. The findings suggest that TET plays a neuroprotective role via reducing neuron apoptosis and could be a valuable biomarker or potential therapeutic target for the treatment of patients with PD. PMID:26597345

  7. Diethanolamine alters neurogenesis and induces apoptosis in fetal mouse hippocampus

    PubMed Central

    Craciunescu, Corneliu N.; Wu, Renan; Zeisel, Steven H.

    2006-01-01

    Diethanolamine (DEA) is present in many consumer products such as shampoo. Dermal administration of DEA diminishes hepatic stores of the essential nutrient choline, and we previously reported that dietary choline deficiency during pregnancy reduces neurogenesis and increases apoptosis in the hippocampus of fetal rats and mice. Therefore, DEA could also alter brain development. Timed-pregnant C57BL/6 mice were dosed dermally from gestation day 7 through 17 with DEA at 0, 20, 80, 160, 320, and 640 mg/kg body/day. At doses of DEA > 80 mg/kg body/day, we observed decreased litter size. In fetuses (embryonic day 17) collected from dams treated dermally with 80 mg/kg body/day DEA, we observed decreased neural progenitor cell mitosis at the ventricular surface of the ventricular zone of the hippocampus [to 56±14% (SE) histone 3 (H3) phosphorylation as compared to controls; P < 0.01]. We also observed increased apoptosis in fetal hippocampus (to 170±10% of control measured using TUNEL and to 178±7% of control measured using activated caspase 3; P < 0.01). Thus, maternal exposure to DEA reduces the number of neural progenitor cells in hippocampus by two mechanisms, and this could permanently alter memory function in offspring of mothers exposed to this common ingredient of shampoos and soaps.—Craciunescu, C. N., Wu, R., Zeisel, S. H. Diethanolamine alters neurogenesis and induces apoptosis in fetal mouse hippocampus. PMID:16873886

  8. Dihydrolipoic acid induces cytotoxicity in mouse blastocysts through apoptosis processes.

    PubMed

    Houng, Wei-Li; Lin, Cheng-An J; Shen, Ji-Lin; Yeh, Hung-I; Wang, Hsueh-Hsiao; Chang, Walter H; Chan, Wen-Hsiung

    2012-01-01

    α-Lipoic acid (LA) is a thiol with antioxidant properties that protects against oxidative stress-induced apoptosis. LA is absorbed from the diet, taken up by cells and tissues, and subsequently reduced to dihydrolipoic acid (DHLA). In view of the recent application of DHLA as a hydrophilic nanomaterial preparation, determination of its biosafety profile is essential. In the current study, we examined the cytotoxic effects of DHLA on mouse embryos at the blastocyst stage, subsequent embryonic attachment and outgrowth in vitro, in vivo implantation by embryo transfer, and early embryonic development in an animal model. Blastocysts treated with 50 μM DHLA exhibited significantly increased apoptosis and a corresponding decrease in total cell number. Notably, the implantation success rates of blastocysts pretreated with DHLA were lower than that of their control counterparts. Moreover, in vitro treatment with 50 μM DHLA was associated with increased resorption of post-implantation embryos and decreased fetal weight. Data obtained using an in vivo mouse model further disclosed that consumption of drinking water containing 100 μM DHLA led to decreased early embryo development, specifically, inhibition of development to the blastocyst stage. However, it appears that concentrations of DHLA lower than 50 μM do not exert a hazardous effect on embryonic development. Our results collectively indicate that in vitro and in vivo exposure to concentrations of DHLA higher than 50 μM DHLA induces apoptosis and retards early pre- and post-implantation development, and support the potential of DHLA to induce embryonic cytotoxicity. PMID:22489194

  9. Vanadate induces apoptosis in epidermal JB6 P+ cells via hydrogen peroxide-mediated reactions.

    PubMed

    Ye, J; Ding, M; Leonard, S S; Robinson, V A; Millecchia, L; Zhang, X; Castranova, V; Vallyathan, V; Shi, X

    1999-12-01

    Apoptosis is a physiological mechanism for the control of DNA integrity in mammalian cells. Vanadium induces both DNA damage and apoptosis. It is suggested that vanadium-induced apoptosis serves to eliminate DNA-damaged cells. This study is designed to clarify a role of reactive oxygen species in the mechanism of apoptosis induced by vanadium. We established apoptosis model with murine epidermal JB6 P+ cells in the response to vanadium stimulation. Apoptosis was detected by a cell death ELISA assay and morphological analysis. The result shows that apoptosis induced by vanadate is dose-dependent, reaching its saturation level at a concentration of 100 microM vanadate. Vanadyl (IV) can also induce apoptosis albeit with lesser potency. A role of reactive oxygen species was analyzed by multiple reagents including specific scavengers of different reactive oxygen species. The result shows that vanadate-induced apoptosis is enhanced by NADPH, superoxide dismutase and sodium formate, but was inhibited by catalase and deferoxamine. Cells exposed to vanadium consume more molecular oxygen and at the same time, produce more H2O2 as measured by the change in fluorescence of scopoletin in the presence of horseradish peroxidase. This change in oxygen consumption and H2O2 production is enhanced by NADPH. Taken together, these results show that vanadate induces apoptosis in epidermal cells and H2O2 induced by vanadate plays a major role in this process. PMID:10705990

  10. Fangchinoline inhibits breast adenocarcinoma proliferation by inducing apoptosis.

    PubMed

    Xing, Zhi-Bo; Yao, Lei; Zhang, Guo-Qiang; Zhang, Xian-Yu; Zhang, You-Xue; Pang, Da

    2011-01-01

    Radix Stephaniae tetrandrae, which contains tetrandrine (Tet) and fangchinoline, is traditionally used as an analgesic, antirheumatic, and antihypertensive drug in China. In this study, we investigated its effect on breast cancer cell proliferation and its potential mechanism of action in vitro. Treatment of cells with fangchinoline significantly inhibited MDA-MB-231 cell proliferation in a concentration- and time-dependent manner. To define the mechanism underlying the antiproliferative effects of fangchinoline, we studied its effects on critical molecular events known to regulate the apoptotic machinery. Specifically, we addressed the potential of fangchinoline to induce apoptosis of breast cancer cells. Fangchinoline induced internucleosomal DNA fragmentation, chromatin condensation, activation of caspases-3, -8, and -9, and cleavage of poly(ADP ribose) polymerase, as well as enhanced mitochondrial cytochrome c release. Furthermore, fangchinoline increased the expression of the proapoptotic protein B cell lymphoma-2 associated X (Bax) and decreased the expression of the antiapoptotic protein B cell lymphoma-2 (Bcl-2). In addition, the proliferation-inhibitory effect of fangchinoline was associated with decreased levels of phosphorylated Akt. Our results indicate that fangchinoline can inhibit breast cancer cell proliferation by inducing apoptosis via the mitochondrial apoptotic pathway and decreasing phosphorylated Akt. Thus fangchinoline may be a novel agent that can potentially be developed clinically to target human malignancies. PMID:22130369

  11. Cupressus lusitanica (Cupressaceae) leaf extract induces apoptosis in cancer cells.

    PubMed

    Lopéz, L; Villavicencio, M A; Albores, A; Martínez, M; de la Garza, J; Meléndez-Zajgla, J; Maldonado, V

    2002-05-01

    A crude ethanolic extract of Cupressus lusitanica Mill. leaves demonstrate cytotoxicity in a panel of cancer cell lines. Cell death was due to apoptosis, as assessed by morphologic features (chromatin condensation and apoptotic bodies formation) and specific DNA fragmentation detected by in situ end-labeling of DNA breaks (TUNEL). The apoptotic cell death was induced timely in a dose-dependent manner. Despite the absence of changes in the expression levels of antiapoptotic protein Bcl-2, proapoptotic Bax protein variants omega and delta were increased. These results warrant further research of possible antitumor compounds in this plant. PMID:12007700

  12. Atorvastatin restores arsenic-induced vascular dysfunction in rats: Modulation of nitric oxide signaling and inflammatory mediators

    SciTech Connect

    Kesavan, Manickam; Sarath, Thengumpallil Sasindran; Kannan, Kandasamy; Suresh, Subramaniyam; Gupta, Priyanka; Vijayakaran, Karunakaran; Sankar, Palanisamy; Kurade, Nitin Pandurang; Mishra, Santosh Kumar; Sarkar, Souvendra Nath

    2014-10-01

    We evaluated whether atorvastatin, an extensively prescribed statin for reducing the risks of cardiovascular diseases, can reduce the risk of arsenic-induced vascular dysfunction and inflammation in rats and whether the modulation could be linked to improvement in vascular NO signaling. Rats were exposed to sodium arsenite (100 ppm) through drinking water for 90 consecutive days. Atorvastatin (10 mg/kg bw, orally) was administered once daily during the last 30 days of arsenic exposure. On the 91{sup st} day, blood was collected for measuring serum C-reactive protein. Thoracic aorta was isolated for assessing reactivity to phenylephrine, sodium nitroprusside and acetylcholine; evaluating eNOS and iNOS mRNA expression and measuring NO production, while abdominal aorta was used for ELISA of cytokines, chemokine and vascular cell adhesion molecules. Histopathology was done in aortic arches. Arsenic did not alter phenylephrine-elicited contraction. Atorvastatin inhibited E{sub max} of phenylephrine, but it augmented the contractile response in aortic rings from arsenic-exposed animals. Sodium nitroprusside-induced relaxation was not altered with any treatment. However, arsenic reduced acetylcholine-induced relaxation and affected aortic eNOS at the levels of mRNA expression, protein concentration, phosphorylation and NO production. Further, it increased aortic iNOS mRNA expression, iNOS-derived NO synthesis, production of pro-inflammatory mediators (IL-1β, IL-6, MCP-1, VCAM, sICAM) and serum C-reactive protein and aortic vasculopathic lesions. Atorvastatin attenuated these arsenic-mediated functional, biochemical and structural alterations. Results show that atorvastatin has the potential to ameliorate arsenic-induced vascular dysfunction and inflammation by restoring endothelial function with improvement in NO signaling and attenuating production of pro-inflammatory mediators and cell adhesion molecules. - Highlights: • We evaluated if atorvastatin reduce arsenic-induced

  13. Well water arsenic exposure, arsenic induced skin-lesions and self-reported morbidity in Inner Mongolia

    EPA Science Inventory

    Arsenic exposure from contaminated well water is a cause of skin and bladder cancer and linked to numerous other adverse health effects. Residents of the Bayingnormen region of Inner Mongolia, China, have been exposed to arsenic-contaminated well water for over 20 years but few s...

  14. Nitroxoline induces apoptosis and slows glioma growth in vivo

    PubMed Central

    Lazovic, Jelena; Guo, Lea; Nakashima, Jonathan; Mirsadraei, Leili; Yong, William; Kim, Hyun J.; Ellingson, Benjamin; Wu, Hong; Pope, Whitney B.

    2015-01-01

    Background Nitroxoline is an FDA-approved antibiotic with potential antitumor activity. Here we evaluated whether nitroxoline has antiproliferative properties on glioma cell growth in vitro and in vivo using glioma cell lines and a genetically engineered PTEN/KRAS mouse glioma model. Methods The effect of nitroxoline treatment on U87 and/or U251 glioma cell proliferation, cell-cycle arrest, invasion, and ability to induce an apoptotic cascade was determined in vitro. Magnetic resonance imaging was used to measure glioma volumes in genetically engineered PTEN/KRAS mice prior to and after nitroxoline therapy. Induction of apoptosis by nitroxoline was evaluated at the end of treatment using terminal deoxyribonucleotidyl transferase (TDT)-mediated dUTP-digoxigenin nick end labeling (TUNEL). Results Nitroxoline inhibited the proliferation and invasion of glioblastoma cells in a time- and dose-dependent manner in vitro. Growth inhibition was associated with cell-cycle arrest in G1/G0 phase and induction of apoptosis via caspase 3 and cleaved poly(ADP-ribose) polymerase. In vivo, nitroxoline-treated mice had no increase in tumor volume after 14 days of treatment, whereas tumor volumes doubled in control mice. Histological examination revealed 15%–20% TUNEL-positive cells in nitroxoline-treated mice, compared with ∼5% in the control group. Conclusion Nitroxoline induces apoptosis and inhibits glioma growth in vivo and in vitro. As an already FDA-approved treatment for urinary tract infections with a known safety profile, nitroxoline could move quickly into clinical trials pending confirmatory studies. PMID:25074541

  15. Hyperthermia restores apoptosis induced by death receptors through aggregation-induced c-FLIP cytosolic depletion.

    PubMed

    Morlé, A; Garrido, C; Micheau, O

    2015-01-01

    TRAIL is involved in immune tumor surveillance and is considered a promising anti-cancer agent owing to its limited side effects on healthy cells. However, some cancer cells display resistance, or become resistant to TRAIL-induced cell death. Hyperthermia can enhance sensitivity to TRAIL-induced cell death in various resistant cancer cell lines, including lung, breast, colon or prostate carcinomas. Mild heat shock treatment has been proposed to restore Fas ligand or TRAIL-induced apoptosis through c-FLIP degradation or the mitochondrial pathway. We demonstrate here that neither the mitochondria nor c-FLIP degradation are required for TRAIL-induced cell death restoration during hyperthermia. Our data provide evidence that insolubilization of c-FLIP, alone, is sufficient to enhance apoptosis induced by death receptors. Hyperthermia induced c-FLIP depletion from the cytosolic fraction, without apparent degradation, thereby preventing c-FLIP recruitment to the TRAIL DISC and allowing efficient caspase-8 cleavage and apoptosis. Hyperthermia-induced c-FLIP depletion was independent of c-FLIP DED2 FL chain assembly motif or ubiquitination-mediated c-FLIP degradation, as assessed using c-FLIP point mutants on lysine 167 and 195 or threonine 166, a phosphorylation site known to regulate ubiquitination of c-FLIP. Rather, c-FLIP depletion was associated with aggregation, because addition of glycerol not only prevented the loss of c-FLIP from the cytosol but also enabled c-FLIP recruitment within the TRAIL DISC, thus inhibiting TRAIL-induced apoptosis during hyperthermia. Altogether our results demonstrate that c-FLIP is a thermosensitive protein whose targeting by hyperthermia allows restoration of apoptosis induced by TNF ligands, including TRAIL. Our findings suggest that combining TRAIL agonists with whole-body or localized hyperthermia may be an interesting approach in cancer therapy. PMID:25675293

  16. Subchronic Arsenic Exposure Induces Anxiety-Like Behaviors in Normal Mice and Enhances Depression-Like Behaviors in the Chemically Induced Mouse Model of Depression.

    PubMed

    Chang, Chia-Yu; Guo, How-Ran; Tsai, Wan-Chen; Yang, Kai-Lin; Lin, Li-Chuan; Cheng, Tain-Junn; Chuu, Jiunn-Jye

    2015-01-01

    Accumulating evidence implicates that subchronic arsenic exposure causes cerebral neurodegeneration leading to behavioral disturbances relevant to psychiatric disorders. However, there is still little information regarding the influence of subchronic exposure to arsenic-contaminated drinking water on mood disorders and its underlying mechanisms in the cerebral prefrontal cortex. The aim of this study is to assess the effects of subchronic arsenic exposure (10 mg/LAs2O3 in drinking water) on the anxiety- and depression-like behaviors in normal mice and in the chemically induced mouse model of depression by reserpine pretreatment. Our findings demonstrated that 4 weeks of arsenic exposure enhance anxiety-like behaviors on elevated plus maze (EPM) and open field test (OFT) in normal mice, and 8 weeks of arsenic exposure augment depression-like behaviors on tail suspension test (TST) and forced swimming test (FST) in the reserpine pretreated mice. In summary, in this present study, we demonstrated that subchronic arsenic exposure induces only the anxiety-like behaviors in normal mice and enhances the depression-like behaviors in the reserpine induced mouse model of depression, in which the cerebral prefrontal cortex BDNF-TrkB signaling pathway is involved. We also found that eight weeks of subchronic arsenic exposure are needed to enhance the depression-like behaviors in the mouse model of depression. These findings imply that arsenic could be an enhancer of depressive symptoms for those patients who already had the attribute of depression. PMID:26114099

  17. Subchronic Arsenic Exposure Induces Anxiety-Like Behaviors in Normal Mice and Enhances Depression-Like Behaviors in the Chemically Induced Mouse Model of Depression

    PubMed Central

    Chang, Chia-Yu; Guo, How-Ran; Tsai, Wan-Chen; Yang, Kai-Lin; Lin, Li-Chuan

    2015-01-01

    Accumulating evidence implicates that subchronic arsenic exposure causes cerebral neurodegeneration leading to behavioral disturbances relevant to psychiatric disorders. However, there is still little information regarding the influence of subchronic exposure to arsenic-contaminated drinking water on mood disorders and its underlying mechanisms in the cerebral prefrontal cortex. The aim of this study is to assess the effects of subchronic arsenic exposure (10 mg/LAs2O3 in drinking water) on the anxiety- and depression-like behaviors in normal mice and in the chemically induced mouse model of depression by reserpine pretreatment. Our findings demonstrated that 4 weeks of arsenic exposure enhance anxiety-like behaviors on elevated plus maze (EPM) and open field test (OFT) in normal mice, and 8 weeks of arsenic exposure augment depression-like behaviors on tail suspension test (TST) and forced swimming test (FST) in the reserpine pretreated mice. In summary, in this present study, we demonstrated that subchronic arsenic exposure induces only the anxiety-like behaviors in normal mice and enhances the depression-like behaviors in the reserpine induced mouse model of depression, in which the cerebral prefrontal cortex BDNF-TrkB signaling pathway is involved. We also found that eight weeks of subchronic arsenic exposure are needed to enhance the depression-like behaviors in the mouse model of depression. These findings imply that arsenic could be an enhancer of depressive symptoms for those patients who already had the attribute of depression. PMID:26114099

  18. Aloe-emodin-induced apoptosis in human gastric carcinoma cells.

    PubMed

    Chen, Sheng-Hsuan; Lin, Kai-Yuan; Chang, Chun-Chao; Fang, Chia-Lang; Lin, Chih-Ping

    2007-11-01

    The purpose of this study was to investigate the anticancer effect of aloe-emodin, an anthraquinone compound present in the leaves of Aloe vera, on two distinct human gastric carcinoma cell lines, AGS and NCI-N87. We demonstrate that aloe-emodin induced cell death in a dose- and time-dependent manner. Noteworthy is that the AGS cells were generally more sensitive than the NCI-N87 cells. Aloe-emodin caused the release of apoptosis-inducing factor and cytochrome c from mitochondria, followed by the activation of caspase-3, leading to nuclear shrinkage and apoptosis. In addition, exposure to aloe-emodin suppressed the casein kinase II activity in a time-dependent manner and was accompanied by a reduced phosphorylation of Bid, a downstream substrate of casein kinase II and a pro-apoptotic molecule. These preclinical studies suggest that aloe-emodin represents a suitable and novel chemotherapeutic drug candidate for the treatment of human gastric carcinoma. PMID:17637488

  19. Involvement of FAN in TNF-induced apoptosis.

    PubMed

    Ségui, B; Cuvillier, O; Adam-Klages, S; Garcia, V; Malagarie-Cazenave, S; Lévêque, S; Caspar-Bauguil, S; Coudert, J; Salvayre, R; Krönke, M; Levade, T

    2001-07-01

    TNF-alpha is a pleiotropic cytokine activating several signaling pathways initiated at distinct intracellular domains of the TNF receptors. Although the C-terminal region is believed to be responsible for apoptosis induction, the functions of more membrane-proximal domains, including the domain that couples to neutral sphingomyelinase activation, are not yet fully elucidated. The roles of this region and of the associated adapter protein FAN (factor associated with neutral SMase activation) in the cytotoxic response to TNF have been investigated. We have now shown that stable expression in human fibroblasts of a dominant negative form of FAN abrogates TNF-induced ceramide generation from sphingomyelin hydrolysis and reduces caspase processing, thus markedly inhibiting TNF-triggered apoptosis. However, the cytotoxic responses to daunorubicin and exogenous ceramide remain unaltered, as do the TNF-induced p42/p44 MAPK activation and CD54 expression. Fibroblasts from FAN-knockout mice also proved to be resistant to TNF toxicity. These findings highlight the previously unrecognized role of the adapter protein FAN in signaling cell death induction by TNF. PMID:11435466

  20. Antiplatelet drugs induce apoptosis in cultured cancer cells.

    PubMed

    Chen, W H; Yin, H L; Chang, Y Y; Lan, M Y; Hsu, H Y; Liu, J S

    1997-10-01

    In order to understand if antiplatelet drugs possess direct antineoplastic property, we tested the apoptotic effect of 5 popularly marketed antiplatelet drugs in Taiwan in 6 cultured cancer cell lines (Hep 3B hepatocarcinoma, U87-MG malignant glioma, PC-3 prostate adenocarcinoma, HeLa cervical adenocarcinoma, HL-60 preleukemia and K-562 chronic myelogenous leukemia). While acetylsalicylate and flunarizine exerted no effect on these cancer cells, pentoxifyline (PTX), dipyridamole (DYA) and ticlopidine hydrochloride (T. HCl) displayed a time and dose-dependent apoptotic effect on them except for HL-60 and K-562 cells. PTX induced apoptosis in U87-MG, Hep 3B and HeLa cells, DYA in HeLa cells, while T. HCl in U87-MG, Hep 3B, PC-3 and HeLa cells. Adriamycin also provoked apoptotic effect in all 6 cell lines but neither PTX, DYA nor T. HCl acted synergy with adriamycin to HeLa cells, implicating that they may share a similar pathway for inducing apoptosis. Therefore, our results show that the antiplatelet drugs do possess antineoplastic property in vitro. A co-administration of antiplatelet drugs is noteworthy for an alternative adjunctive therapy in cancer patients. PMID:9385774

  1. Lead Induces Apoptosis and Histone Hyperacetylation in Rat Cardiovascular Tissues

    PubMed Central

    Xu, Li-Hui; Mu, Fang-Fang; Zhao, Jian-Hong; He, Qiang; Cao, Cui-Li; Yang, Hui; Liu, Qi; Liu, Xue-Hui; Sun, Su-Ju

    2015-01-01

    Acute and chronic lead (Pb) exposure might cause hypertension and cardiovascular diseases. The purpose of this study was to evaluate the effects of early acute exposure to Pb on the cellular morphology, apoptosis, and proliferation in rats and to elucidate the early mechanisms involved in the development of Pb-induced hypertension. Very young Sprague-Dawley rats were allowed to drink 1% Pb acetate for 12 and 40 days. Western blot analysis indicated that the expression of proliferating cell nuclear antigen (PCNA) decreased in the tissues of the abdominal and thoracic aortas and increased in the cardiac tissue after 12 and 40 days of Pb exposure, respectively. Bax was upregulated and Bcl-2 was downregulated in vascular and cardiac tissues after 40 days of Pb exposure. In addition, an increase in caspase-3 activity was observed after 40 days of exposure to Pb. In terms of morphology, we found that the internal elastic lamina (IEL) of aorta lost the original curve and the diameter of cardiac cell was enlarged after 40 days. Furthermore, the exposure led to a marked increase in acetylated histone H3 levels in the aortas and cardiac tissue after 12 and 40 days, than that in the control group. These findings indicate that Pb might increase the level of histone acetylation and induce apoptosis in vascular and cardiac tissues. However, the mechanism involved need to be further investigated. PMID:26075388

  2. Vanadium induced ultrastructural changes and apoptosis in male germ cells.

    PubMed

    Aragón, M A; Ayala, M E; Fortoul, T I; Bizarro, P; Altamirano-Lozano, M

    2005-01-01

    Vanadium is a transition metal that is emitted to the atmosphere during combustion of fossil fuels. In the environment, vanadium occurs in the (V) oxidized form, but in the body it is found exclusively in the (IV) oxidized form. Vanadium tetraoxide is an inorganic chemical species in the (IV) oxidized form that has been shown to induce toxic effects in vitro and in vivo. The reproductive toxicity of vanadium in males was studied through monitoring germ cell apoptosis during spermatogenesis. We analyzed ultrastructural damage, and testosterone and progesterone concentrations following vanadium tetraoxide administered to male mice for 60 days. Spermatogenesis stages I-III and X-XII frequently showed apoptotic germ cells in control and treated animals; vanadium tetraoxide treatment induced an increase in the number of germ cell apoptosis in stages I-III and XII at 9.4 and 18.8 mg/kg, respectively. Although spermatogenesis is regulated by testosterone, in our study this hormone level was not modified by vanadium administration; thus, germ cell death was not related with testosterone concentration. At the ultrastructural level, we observed inclusion structures that varied as to location and content in the Sertoli and germ cells. PMID:15808796

  3. Aggregated Myocilin Induces Russell Bodies and Causes Apoptosis

    PubMed Central

    Yam, Gary Hin-Fai; Gaplovska-Kysela, Katarina; Zuber, Christian; Roth, Jürgen

    2007-01-01

    Primary open-angle glaucoma with elevated intraocular pressure is a leading cause of blindness worldwide. Mutations of myocilin are known to play a critical role in the manifestation of the disease. Misfolded mutant myocilin forms secretion-incompetent intracellular aggregates. The block of myocilin secretion was proposed to alter the extracellular matrix environment of the trabecular meshwork, with subsequent impediment of aqueous humor outflow leading to elevated intraocular pressure. However, the molecular pathogenesis of myocilin-caused glaucoma is poorly defined. In this study, we show that heteromeric complexes composed of wild-type and mutant myocilin were retained in the rough endoplasmic reticulum, aggregating to form inclusion bodies typical of Russell bodies. The presence of myocilin aggregates induced the unfolded protein response proteins BiP and phosphorylated endoplasmic reticulum-localized eukaryotic initiation factor-2α kinase (PERK) with the subsequent activation of caspases 12 and 3 and expression of C/EBP homologous protein (CHOP)/GADD153, leading to apoptosis. Our findings identify endoplasmic reticulum stress-induced apoptosis as a pathway to explain the reduction of trabecular meshwork cells in patients with myocilin-caused glaucoma. As a consequence, the phagocytotic capacity of the remaining trabecular meshwork cell population would be insufficient for effective cleaning of aqueous humor, constituting a major pathogenetic factor for the development of increased intraocular pressure in primary open-angle glaucoma. PMID:17200186

  4. Specific antibodies induce apoptosis in Trypanosoma cruzi epimastigotes.

    PubMed

    Fernández-Presas, Ana María; Tato, Patricia; Becker, Ingeborg; Solano, Sandra; Copitin, Natalia; Kopitin, Natalia; Berzunza, Miriam; Willms, Kaethe; Hernández, Joselin; Molinari, José Luis

    2010-05-01

    The susceptibility of Trypanosoma cruzi epimastigotes to lysis by normal or immune sera in a complement-dependent reaction has been reported. Mouse immune sera depleted complement-induced damage in epimastigotes characterized by morphological changes and death. The purpose of this work was to study the mechanism of death in epimastigotes exposed to decomplemented mouse immune serum. Epimastigotes were maintained in RPMI medium. Immune sera were prepared in mice by immunization with whole crude epimastigote extracts. Viable epimastigotes were incubated with decomplemented normal or immune sera at 37 degrees C. By electron microscopy, agglutinated parasites showed characteristic patterns of membrane fusion between two or more parasites; this fusion also produced interdigitation of the subpellicular microtubules. Apoptosis was determined by flow cytometry using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and annexin V assays. Nuclear features were examined by 4'-,6-diamidino-2'-phenylindole diHCI cytochemistry that demonstrated apoptotic nuclear condensation. Caspase activity was also measured. TUNEL results showed that parasites incubated with decomplemented immune sera took up 26% of specific fluorescence as compared to 1.3% in parasites incubated with decomplemented normal sera. The Annexin-V-Fluos staining kit revealed that epimastigotes incubated with decomplemented immune sera exposed phosphatidylserine on the external leaflet of the plasma membrane. The incubation of parasites with immune sera showed caspase 3 activity. We conclude that specific antibodies are able to induce agglutination and apoptosis in epimastigotes, although the pathway is not elucidated. PMID:20237802

  5. Ursodeoxycholic acid induces apoptosis in hepatocellular carcinoma xenografts in mice

    PubMed Central

    Liu, Hui; Xu, Hong-Wei; Zhang, Yu-Zhen; Huang, Ya; Han, Guo-Qing; Liang, Tie-Jun; Wei, Li-Li; Qin, Cheng-Yong; Qin, Cheng-Kun

    2015-01-01

    AIM: To evaluate the efficacy of ursodeoxycholic acid (UDCA) as a chemotherapeutic agent for the treatment of hepatocellular carcinoma (HCC). METHODS: BALB/c nude mice were randomized into four groups 24 h before subcutaneous injection of hepatocarcinoma BEL7402 cells suspended in phosphate buffered saline (PBS) into the right flank. The control group (n = 10) was fed a standard diet while treatment groups (n = 10 each) were fed a standard daily diet supplemented with different concentrations of UDCA (30, 50 and 70 mg/kg per day) for 21 d. Tumor growth was measured once each week, and tumor volume (V) was calculated with the following equation: V = (L × W2) × 0.52, where L is the length and W is the width of the xenograft. After 21 d, mice were killed under ether anesthesia, and tumors were excised and weighed. Apoptosis was evaluated through detection of DNA fragmentation with gel electrophoresis and the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay. Western blot analysis was performed to determine the expression of apoptosis-related proteins BAX, BCL2, APAF1, cleaved caspase-9, and cleaved caspase-3. RESULTS: UDCA suppressed tumor growth relative to controls. The mean tumor volumes were the following: control, 1090 ± 89 mm3; 30 mg/kg per day, 612 ± 46 mm3; 50 mg/kg per day, 563 ± 38 mm3; and 70 mg/kg per day, 221 ± 26 mm3. Decreased tumor volumes reached statistical significance relative to control xenografts (30 mg/kg per day, P < 0.05; 50 mg/kg per day, P < 0.05; 70 mg/kg per day, P < 0.01). Increasing concentrations of UDCA led to increased DNA fragmentation observed on gel electrophoresis and in the TUNEL assay (control, 1.6% ± 0.3%; 30 mg/kg per day, 2.9% ± 0.5%; 50 mg/kg per day, 3.15% ± 0.7%, and 70 mg/kg per day, 4.86% ± 0.9%). Western blot analysis revealed increased expression of BAX, APAF1, cleaved-caspase-9 and cleaved-caspase-3 proteins, which induce apoptosis, but decreased expression of BCL2

  6. Metformin prevents methylglyoxal-induced apoptosis of mouse Schwann cells

    SciTech Connect

    Ota, Kimiko; Nakamura, Jiro; Li, Weiguo; Kozakae, Mika; Watarai, Atsuko; Nakamura, Nobuhisa; Yasuda, Yutaka; Nakashima, Eirtaro; Naruse, Keiko; Watabe, Kazuhiko; Kato, Koichi; Oiso, Yutaka; Hamada, Yoji . E-mail: yhama@med.nagoya-u.ac.jp

    2007-05-25

    Methylglyoxal (MG) is involved in the pathogenesis of diabetic complications via the formation of advanced glycation end products (AGEs) and reactive oxygen species (ROS). To clarify whether the antidiabetic drug metformin prevents Schwann cell damage induced by MG, we cultured mouse Schwann cells in the presence of MG and metformin. Cell apoptosis was evaluated using Hoechst 33342 nuclear staining, caspase-3 activity, and c-Jun-N-terminal kinase (JNK) phosphorylation. Intracellular ROS formation was determined by flow cytometry, and AMP-activated kinase (AMPK) phosphorylation was also examined. MG treatment resulted in blunted cell proliferation, an increase in the number of apoptotic cells, and the activation of caspase-3 and JNK along with enhanced intracellular ROS formation. All of these changes were significantly inhibited by metformin. No significant activation of AMPK by MG or metformin was observed. Taken together, metformin likely prevents MG-induced apoptotic signals in mouse Schwann cells by inhibiting the formation of AGEs and ROS.

  7. Targeting Glutamine Induces Apoptosis: A Cancer Therapy Approach

    PubMed Central

    Chen, Lian; Cui, Hengmin

    2015-01-01

    Glutamine metabolism has been proved to be dysregulated in many cancer cells, and is essential for proliferation of most cancer cells, which makes glutamine an appealing target for cancer therapy. In order to be well used by cells, glutamine must be transported to cells by specific transporters and converted to glutamate by glutaminase. There are currently several drugs that target glutaminase under development or clinical trials. Also, glutamine metabolism restriction has been proved to be effective in inhibiting tumor growth both in vivo and vitro through inducing apoptosis, growth arrest and/or autophagy. Here, we review recent researches about glutamine metabolism in cancer, and cell death induced by targeting glutamine, and their potential roles in cancer therapy. PMID:26402672

  8. Multiple risk factors associated with arsenic-induced skin cancer: effects of chronic liver disease and malnutritional status.

    PubMed Central

    Hsueh, Y. M.; Cheng, G. S.; Wu, M. M.; Yu, H. S.; Kuo, T. L.; Chen, C. J.

    1995-01-01

    In order to evaluate the prevalence and multiple risk factors of arsenic-induced skin cancer among residents in Taiwanese villages in which chronic arseniasis is hyperendemic, a total of 1571 subjects aged 30 or more years were recruited between September 1988 and March 1989. All of them were interviewed personally by a public health nurse using a structured questionnaire, and 1081 interviewed study subjects, including 468 men and 613 women, participated in physical examination, giving a participation rate of 68.8%. The overall prevalence of skin cancer was as high as 6.1%, showing an increase with age in both men and women. There was a significant dose-response relation between skin cancer prevalence and chronic arsenic exposure as indexed by duration of residence in the endemic area, duration of consumption of high-arsenic artesian well water, average arsenic exposure in parts per million (p.p.m.) and cumulative arsenic exposure in p.p.m.-years. Chronic carriers of hepatitis B surface antigen with liver dysfunction had an increased prevalence of skin cancer. Undernourishment, indexed by a high consumption of dried sweet potato as a staple food, was also significantly associated with an increased prevalence of arsenic-induced skin cancer. All these risk factors remained statistically significant in the multiple logistic regression analysis. Consistent with animal experiments, the findings imply that liver function and nutritional status may affect the metabolism of inorganic arsenic and the development of subsequent skin cancers. PMID:7819025

  9. Reactive oxygen species contribute to arsenic-induced EZH2 phosphorylation in human bronchial epithelial cells and lung cancer cells

    SciTech Connect

    Li, Lingzhi; Qiu, Ping; Chen, Bailing; Lu, Yongju; Wu, Kai; Thakur, Chitra; Chang, Qingshan; Sun, Jiaying; Chen, Fei

    2014-05-01

    Our previous studies suggested that arsenic is able to induce serine 21 phosphorylation of the EZH2 protein through activation of JNK, STAT3, and Akt signaling pathways in the bronchial epithelial cell line, BEAS-2B. In the present report, we further demonstrated that reactive oxygen species (ROS) were involved in the arsenic-induced protein kinase activation that leads to EZH2 phosphorylation. Several lines of evidence supported this notion. First, the pretreatment of the cells with N-acetyl-L-cysteine (NAC), a potent antioxidant, abolishes arsenic-induced EZH2 phosphorylation along with the inhibition of JNK, STAT3, and Akt. Second, H{sub 2}O{sub 2}, the most important form of ROS in the cells in response to extracellular stress signals, can induce phosphorylation of the EZH2 protein and the activation of JNK, STAT3, and Akt. By ectopic expression of the myc-tagged EZH2, we additionally identified direct interaction and phosphorylation of the EZH2 protein by Akt in response to arsenic and H{sub 2}O{sub 2}. Furthermore, both arsenic and H{sub 2}O{sub 2} were able to induce the translocation of ectopically expressed or endogenous EZH2 from nucleus to cytoplasm. In summary, the data presented in this report indicate that oxidative stress due to ROS generation plays an important role in the arsenic-induced EZH2 phosphorylation. - Highlights:: • Arsenic (As{sup 3+}) induces EZH phosphorylation. • JNK, STAT3, and Akt contribute to EZH2 phosphorylation. • Oxidative stress is involved in As{sup 3+}-induced EZH2 phosphorylation. • As{sup 3+} induces direct interaction of Akt and EZH2. • Phosphorylated EZH2 localized in cytoplasm.

  10. Oligofructose protects against arsenic-induced liver injury in a model of environment/obesity interaction

    SciTech Connect

    Massey, Veronica L.; Stocke, Kendall S.; Schmidt, Robin H.; Tan, Min; Ajami, Nadim; Neal, Rachel E.; Petrosino, Joseph F.; Barve, Shirish; Arteel, Gavin E.

    2015-05-01

    Arsenic (As) tops the ATSDR list of hazardous environmental chemicals and is known to cause liver injury. Although the concentrations of As found in the US water supply are generally too low to directly damage the liver, subhepatotoxic doses of As sensitize the liver to experimental NAFLD. It is now suspected that GI microbiome dysbiosis plays an important role in development of NALFD. Importantly, arsenic has also been shown to alter the microbiome. The purpose of the current study was to test the hypothesis that the prebiotic oligofructose (OFC) protects against enhanced liver injury caused by As in experimental NAFLD. Male C57Bl6/J mice were fed low fat diet (LFD), high fat diet (HFD), or HFD containing oligofructose (OFC) during concomitant exposure to either tap water or As-containing water (4.9 ppm as sodium arsenite) for 10 weeks. HFD significantly increased body mass and caused fatty liver injury, as characterized by an increased liver weight-to-body weight ratio, histologic changes and transaminases. As observed previously, As enhanced HFD-induced liver damage, which was characterized by enhanced inflammation. OFC supplementation protected against the enhanced liver damage caused by As in the presence of HFD. Interestingly, arsenic, HFD and OFC all caused unique changes to the gut flora. These data support previous findings that low concentrations of As enhance liver damage caused by high fat diet. Furthermore, these results indicate that these effects of arsenic may be mediated, at least in part, by GI tract dysbiosis and that prebiotic supplementation may confer significant protective effects. - Highlights: • Arsenic (As) enhances liver damage caused by a high-fat (HFD) diet in mice. • Oligofructose protects against As-enhanced liver damage caused by HFD. • As causes dysbiosis in the GI tract and exacerbates the dysbiosis caused by HFD. • OFC prevents the dysbiosis caused by HFD and As, increasing commensal bacteria.