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Sample records for prevents apoptosis induced

  1. Quercetin-induced apoptosis prevents EBV infection.

    PubMed

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

    2015-05-20

    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.

  2. 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

  3. Crocetin prevents AGEs-induced vascular endothelial cell apoptosis.

    PubMed

    Xiang, Min; Yang, Min; Zhou, Chenghua; Liu, Juan; Li, Wenna; Qian, Zhiyu

    2006-10-01

    Advanced glycation end products (AGEs) are causally correlated with diabetic vascular complications. AGEs triggered oxidative reaction then accelerated endothelial cell apoptosis is a critical event in the process of vascular complications. Crocetin, a carotenoid has been previously shown to have strong antioxidant activates. Therefore, this study was designed to investigate the role of crocetin on the prevention of AGEs-mediated cell apoptosis in bovine aortic endothelial cells (BEC) and the mechanisms involved. Exposure of BEC to 200 microg/ml AGEs for 48 h results in a significant increase in apoptotic rate, compared with control. AGEs-induced DNA fragmentation preferentially occurred in the S phase cells. Crocetin prevented AGEs-induced BEC apoptosis, which correlates with crocetin attenuation of AGEs mediated increase of intracellular reactive oxygen species (ROS) formation and elevation of intracellular Ca2+ concentration ([Ca2+]i) level (P<0.01 versus AGEs group). These results demonstrate that crocetin prevents AGEs-induced BEC apoptosis through ROS inhibition and [Ca2+]i stabilization and suggest that crocetin may exert a beneficial effect in preventing diabetes-associated vascular complications. PMID:16899372

  4. 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.

  5. Geniposide prevents rotenone-induced apoptosis in primary cultured neurons

    PubMed Central

    Li, Lin; Zhao, Juan; Liu, Ke; Li, Guang-lai; Han, Yan-qing; Liu, Yue-ze

    2015-01-01

    Geniposide, a monomer extracted from gardenia and widely used in Chinese medicine, is a novel agonist at the glucagon-like peptide-1 receptor. This receptor is involved in neuroprotection. In the present study, we sought to identify an anti-apoptotic mechanism for the treatment of neurodegenerative diseases. Primary cultured neurons were treated with different concentrations of rotenone for 48 hours. Morphological observation, cell counting kit-8 assay, lactate dehydrogenase detection and western blot assay demonstrated that 0.5 nM rotenone increased lactate dehydrogenase release, decreased the expression of procaspase-3 and Bcl-2, and increased cleaved caspase-3 expression in normal neurons. All these effects were prevented by geniposide. Our results indicate that geniposide diminished rotenone-induced injury in primary neurons by suppressing apoptosis. This may be one of the molecular mechanisms underlying the efficacy of geniposide in the treatment of neurodegenerative diseases. PMID:26692859

  6. Antioxidants in the prevention of UVB-induced keratynocyte apoptosis.

    PubMed

    Salucci, Sara; Burattini, Sabrina; Curzi, Davide; Buontempo, Francesca; Martelli, Alberto Maria; Zappia, Giovanni; Falcieri, Elisabetta; Battistelli, Michela

    2014-12-01

    Skin cells can respond to UVB-induced damage by counteracting it through antioxidant activation and DNA repair mechanisms or, when damage is massive by undergoing programmed cell death. Antioxidant factors, and, in particular, food compounds, have attracted much interest because of their potential use in new protective strategies for degenerative skin disorders. Melatonin, creatine and hydroxytyrosol show a variety of pharmacological and clinical benefits including anti-oxidant and anti-inflammatory activities. Here, the potential protective actions of antioxidant compounds against UVB-induced apoptosis were investigated in human keratinocytes. The cells were pre-treated with antioxidants before UVB exposure and their effect evaluated by means of ultrastructural and molecular analyses. After UVB radiation typical morphological apoptotic features and in situ DNA fragmentation after TUNEL reaction, appeared. A significant numerical decrease of apoptotic patterns could be observed when antioxidants were administrated before cell death induction. Moreover, both the intrinsic and extrinsic apoptotic pathways appeared activated after UVB radiation, and their down-regulation has been shown when antioxidants were added to cells before death induction. In conclusion, these compounds are able to prevent apoptotic cell death in human keratinocytes exposed to UVB, suggesting, for these molecules, an important role in preventing skin damage.

  7. Avenanthramides Prevent Osteoblast and Osteocyte Apoptosis and Induce Osteoclast Apoptosis in Vitro in an Nrf2-Independent Manner

    PubMed Central

    Pellegrini, Gretel G.; Morales, Cynthya C.; Wallace, Taylor C.; Plotkin, Lilian I.; Bellido, Teresita

    2016-01-01

    Oats contain unique bioactive compounds known as avenanthramides (AVAs) with antioxidant properties. AVAs might enhance the endogenous antioxidant cellular response by activation of the transcription factor Nrf2. Accumulation of reactive oxygen species plays a critical role in many chronic and degenerative diseases, including osteoporosis. In this disease, there is an imbalance between bone formation by osteoblasts and bone resorption by osteoclasts, which is accompanied by increased osteoblast/osteocyte apoptosis and decreased osteoclast apoptosis. We investigated the ability of the synthethic AVAs 2c, 2f and 2p, to 1-regulate gene expression in bone cells, 2-affect the viability of osteoblasts, osteocytes and osteoclasts, and the generation of osteoclasts from their precursors, and 3-examine the potential involvement of the transcription factor Nrf2 in these actions. All doses of AVA 2c and 1 and 5 µM dose of 2p up-regulated collagen 1A expression. Lower doses of AVAs up-regulated OPG (osteoprotegerin) in OB-6 osteoblastic cells, whereas 100 μM dose of 2f and all concentrations of 2c down-regulated RANKL gene expression in MLO-Y4 osteocytic cells. AVAs did not affect apoptosis of OB-6 osteoblastic cells or MLO-Y4 osteocytic cells; however, they prevented apoptosis induced by the DNA topoisomerase inhibitor etoposide, the glucocorticoid dexamethasone, and hydrogen peroxide. AVAs prevented apoptosis of both wild type (WT) and Nrf2 Knockout (KO) osteoblasts, demonstrating that AVAs-induced survival does not require Nrf2 expression. Further, KO osteoclast precursors produced more mature osteoclasts than WT; and KO cultures exhibited less apoptotic osteoclasts than WT cultures. Although AVAs did not affect WT osteoclasts, AVA 2p reversed the low apoptosis of KO osteoclasts. These in vitro results demonstrate that AVAs regulate, in part, the function of osteoblasts and osteocytes and prevent osteoblast/osteocyte apoptosis and increase osteoclast apoptosis; further

  8. Avenanthramides Prevent Osteoblast and Osteocyte Apoptosis and Induce Osteoclast Apoptosis in Vitro in an Nrf2-Independent Manner.

    PubMed

    Pellegrini, Gretel G; Morales, Cynthya C; Wallace, Taylor C; Plotkin, Lilian I; Bellido, Teresita

    2016-01-01

    Oats contain unique bioactive compounds known as avenanthramides (AVAs) with antioxidant properties. AVAs might enhance the endogenous antioxidant cellular response by activation of the transcription factor Nrf2. Accumulation of reactive oxygen species plays a critical role in many chronic and degenerative diseases, including osteoporosis. In this disease, there is an imbalance between bone formation by osteoblasts and bone resorption by osteoclasts, which is accompanied by increased osteoblast/osteocyte apoptosis and decreased osteoclast apoptosis. We investigated the ability of the synthethic AVAs 2c, 2f and 2p, to 1-regulate gene expression in bone cells, 2-affect the viability of osteoblasts, osteocytes and osteoclasts, and the generation of osteoclasts from their precursors, and 3-examine the potential involvement of the transcription factor Nrf2 in these actions. All doses of AVA 2c and 1 and 5 µM dose of 2p up-regulated collagen 1A expression. Lower doses of AVAs up-regulated OPG (osteoprotegerin) in OB-6 osteoblastic cells, whereas 100 μM dose of 2f and all concentrations of 2c down-regulated RANKL gene expression in MLO-Y4 osteocytic cells. AVAs did not affect apoptosis of OB-6 osteoblastic cells or MLO-Y4 osteocytic cells; however, they prevented apoptosis induced by the DNA topoisomerase inhibitor etoposide, the glucocorticoid dexamethasone, and hydrogen peroxide. AVAs prevented apoptosis of both wild type (WT) and Nrf2 Knockout (KO) osteoblasts, demonstrating that AVAs-induced survival does not require Nrf2 expression. Further, KO osteoclast precursors produced more mature osteoclasts than WT; and KO cultures exhibited less apoptotic osteoclasts than WT cultures. Although AVAs did not affect WT osteoclasts, AVA 2p reversed the low apoptosis of KO osteoclasts. These in vitro results demonstrate that AVAs regulate, in part, the function of osteoblasts and osteocytes and prevent osteoblast/osteocyte apoptosis and increase osteoclast apoptosis; further

  9. Melatonin prevents apoptosis induced by 6-hydroxydopamine in neuronal cells: implications for Parkinson's disease.

    PubMed

    Mayo, J C; Sainz, R M; Uria, H; Antolin, I; Esteban, M M; Rodriguez, C

    1998-04-01

    It was recently reported that low doses of 6-hydroxydopamine (6-OHDA) induce apoptosis of naive (undifferentiated) and neuronal (differentiated) PC12 cells, and this system has been proposed as an adequate experimental model for the study of Parkinson's disease. The mechanism by which this neurotoxin damages cells is via the production of free radicals. Given that the neurohormone melatonin has been reported 1) to be a highly effective endogenous free radical scavenger, 2) to increase the mRNA levels and the activity of several antioxidant enzymes, and 3) to inhibit apoptosis in other tissues, we have studied the ability of melatonin to prevent the programmed cell death induced by 6-OHDA in PC12 cells. We found that melatonin prevents the apoptosis caused by 6-OHDA in naive and neuronal PC12 cells as estimated by 1) cell viability assays, 2) counting of the number of apoptotic cells, and 3) analysis and quantification of DNA fragmentation. Exploration of the mechanisms used by melatonin to reduce programmed cell death revealed that this chemical mediator prevents the 6-OHDA induced reduction of mRNAs for several antioxidant enzymes. The possibility that melatonin utilized additional mechanisms to prevent apoptosis of these cells is also discussed. Since this endogenous agent has no known side effects and readily crosses the blood-brain-barrier, we consider melatonin to have a high clinical potential in the treatment of Parkinson's disease and possibly other neurodegenerative diseases, although more research on the mechanisms is yet to be done.

  10. Isoniazid prevents Nrf2 translocation by inhibiting ERK1 phosphorylation and induces oxidative stress and apoptosis

    PubMed Central

    Verma, Ajeet Kumar; Yadav, Arti; Dewangan, Jayant; Singh, Sarvendra Vikram; Mishra, Manisha; Singh, Pradhyumna Kumar; Rath, Srikanta Kumar

    2015-01-01

    Isoniazid is used either alone or in combination with other drugs for the treatment of tuberculosis. It is also used for the prevention of tuberculosis. Chronic treatment of Isoniazid may cause severe liver damage leading to acute liver failure. The mechanism through which Isoniazid causes liver damage is investigated. Isoniazid treatment generates reactive oxygen species and induces apoptosis in Hep3B cells. It induces antioxidative and apoptotic genes leading to increase in mRNA expression and protein levels in Hep3B cells. Whole genome expression analysis of Hep3B cells treated with Isoniazid has resulted in differential expression of various genes playing prime role in regulation of apoptotic, antioxidative, DNA damage, cell signaling, cell proliferation and differentiation pathways. Isoniazid increased cytosolic Nrf2 protein level while decreased nuclear Nrf2 protein level. It also decreased ERK1 phosphorylation and treatment of Hep3B cells with ERK inhibitor followed by Isoniazid resulting in increased apoptosis in these cells. Two dimensional gel electrophoresis results have also shown differential expression of various protein species including heat shock proteins, proteins playing important role in oxidative stress, DNA damage, apoptosis, cell proliferation and differentiation. Results suggest that Isoniazid induces apoptosis through oxidative stress and also prevents Nrf2 translocation into the nucleus by reducing ERK1 phosphorylation thus preventing cytoprotective effect. PMID:26202867

  11. Naringin prevents ovariectomy-induced osteoporosis and promotes osteoclasts apoptosis through the mitochondria-mediated apoptosis pathway

    SciTech Connect

    Li, Fengbo; Sun, Xiaolei; Ma, Jianxiong; Ma, Xinlong; Zhao, Bin; Zhang, Yang; Tian, Peng; Li, Yanjun; Han, Zhe

    2014-09-26

    Highlights: • Naringin possesses many pharmacological activities, promotes the proliferation of osteoblast. • Undecalcified histological obtain dynamic parameters of callus formation and remodeling. • Naringin regulate osteoclast apoptosis by mitochondrial pathway. - Abstract: Naringin, the primary active compound of the traditional Chinese medicine Rhizoma drynariae, possesses many pharmacological activities. The present study is an effort to explore the anti-osteoporosis potential of naringin in vivo and in vitro. In vivo, we used ovariectomized rats to clarify the mechanisms by which naringin anti-osteoporosis. In vitro, we used osteoclasts to investigate naringin promotes osteoclasts apoptosis. Naringin was effective at enhancing BMD, trabecular thickness, bone mineralization, and mechanical strength in a dose-dependent manner. The result of RT-PCR analysis revealed that naringin down-regulated the mRNA expression levels of BCL-2 and up-regulated BAX, caspase-3 and cytochrome C. In addition, naringin significantly reduced the bone resorption area in vitro. These findings suggest that naringin promotes the apoptosis of osteoclasts by regulating the activity of the mitochondrial apoptosis pathway and prevents OVX-induced osteoporosis in rats.

  12. Arsenite-induced apoptosis is prevented by antioxidants in zebrafish liver cell line.

    PubMed

    Seok, Seung-Hyeok; Baek, Min-Won; Lee, Hui-Young; Kim, Dong-Jae; Na, Yi-Rang; Noh, Kyoung-Jin; Park, Sung-Hoon; Lee, Hyun-Kyoung; Lee, Byoung-Hee; Ryu, Doug-Young; Park, Jae-Hak

    2007-08-01

    This study evaluated oxidative stress-induced apoptosis as a possible mechanism of arsenite toxicity in zebrafish liver cell line (ZFL cells). The heat shock protein 70 (HSP70), a chaperone protein, appears to provide protection against oxidative stress and apoptosis. Using the MTT assay, we demonstrated that survival of ZFL cells treated with arsenite for 24h decreased in a dose-dependent manner. The possible mechanisms that promote the cytotoxicity of arsenite were addressed. Cell viability assays revealed that arsenite caused a dose-dependent increase in cell death, and pretreatment of the ZFL cells with antioxidants blunted these effects. Antioxidants such as N-acetyl-cysteine (NAC, 5 mM) and dithiothreitol (DTT, 80 microM) significantly prevented ZFL cells from arsenite-induced death. Nuclear staining was performed using 1 microg/ml Hoechst, and cells were analyzed with a fluorescent microscope. Arsenite (30 microM) induced massive apoptosis that was identified by morphology and condensation and fragmentation of the nuclei of the ZFL cells. Pretreatment with NAC or DTT before arsenite insult effectively protected the cells against oxidative stress-induced apoptosis from the arsenite. Using a transfected human hsp 70 promoter-enhanced green fluorescent protein (EGFP) reporter, pHhsp70-EGFP, the induction of HSP70 against oxidative stress-induced apoptosis by arsenite was observed. The induction of HSP70 by arsenite increased in a dose-dependent manner, and pretreatment of transfected ZFL cells with NAC or DTT before arsenite insult reduced EGFP expression. Taken together, our results provide evidence that stimulation of the heat shock response is a sensitive biomarker of arsenic exposure and that arsenite causes oxidative stress-induced apoptosis in ZFL cells. PMID:17416483

  13. Arsenite-induced apoptosis is prevented by antioxidants in zebrafish liver cell line.

    PubMed

    Seok, Seung-Hyeok; Baek, Min-Won; Lee, Hui-Young; Kim, Dong-Jae; Na, Yi-Rang; Noh, Kyoung-Jin; Park, Sung-Hoon; Lee, Hyun-Kyoung; Lee, Byoung-Hee; Ryu, Doug-Young; Park, Jae-Hak

    2007-08-01

    This study evaluated oxidative stress-induced apoptosis as a possible mechanism of arsenite toxicity in zebrafish liver cell line (ZFL cells). The heat shock protein 70 (HSP70), a chaperone protein, appears to provide protection against oxidative stress and apoptosis. Using the MTT assay, we demonstrated that survival of ZFL cells treated with arsenite for 24h decreased in a dose-dependent manner. The possible mechanisms that promote the cytotoxicity of arsenite were addressed. Cell viability assays revealed that arsenite caused a dose-dependent increase in cell death, and pretreatment of the ZFL cells with antioxidants blunted these effects. Antioxidants such as N-acetyl-cysteine (NAC, 5 mM) and dithiothreitol (DTT, 80 microM) significantly prevented ZFL cells from arsenite-induced death. Nuclear staining was performed using 1 microg/ml Hoechst, and cells were analyzed with a fluorescent microscope. Arsenite (30 microM) induced massive apoptosis that was identified by morphology and condensation and fragmentation of the nuclei of the ZFL cells. Pretreatment with NAC or DTT before arsenite insult effectively protected the cells against oxidative stress-induced apoptosis from the arsenite. Using a transfected human hsp 70 promoter-enhanced green fluorescent protein (EGFP) reporter, pHhsp70-EGFP, the induction of HSP70 against oxidative stress-induced apoptosis by arsenite was observed. The induction of HSP70 by arsenite increased in a dose-dependent manner, and pretreatment of transfected ZFL cells with NAC or DTT before arsenite insult reduced EGFP expression. Taken together, our results provide evidence that stimulation of the heat shock response is a sensitive biomarker of arsenic exposure and that arsenite causes oxidative stress-induced apoptosis in ZFL cells.

  14. Vanadate prevents glucocorticoid-induced apoptosis of osteoblasts in vitro and osteocytes in vivo

    PubMed Central

    Conradie, M M; de Wet, H; Kotze, D D R; Burrin, J M; Hough, F S; Hulley, P A

    2007-01-01

    Skeletal mass is maintained by a balance between formation and resorption, cell proliferation and apoptosis. In vitro, glucocorticoids (GCs) decrease extracellular signal-regulated kinases (ERK) activation by mitogens, thus inhibiting osteoblast proliferation. Both ERK activity and proliferation are restored by co-treatment with the protein tyrosine phosphatase inhibitor, vanadate. Since ERK signalling may also be anti-apoptotic, we explored the effects of vanadate on GC-induced apoptosis in vitro and in vivo. Apoptosis in MBA-15.4 pre-osteoblasts increased from 6 h and remained up to eightfold higher through 6 days of 10−6 M dexamethasone (Dex) treatment. Co-incubation with 10−7 M vanadate markedly reduced apoptosis at all time points. Vanadate also prevented GC-induced poly-ADP-ribose polymerase cleavage. We assessed the transcriptional profiles of seven anti-apoptotic proteins (Bcl-2, Bcl-XL, inhibitors of apoptosis protein-1 (IAP-1), IAP-2, X-linked IAP (XIAP), Fas-associated death-domain-like IL-1β-converting enzyme-inhibitory protein (FLIPLong) and FLIPShort) in osteoblasts subjected to various stimuli using real-time quantitative PCR. Although these anti-apoptotic genes responded to different mitogenic conditions, Dex failed to repress their expression, and in fact significantly up-regulated Bcl-XL, IAP-2 and XIAP. Dex may therefore induce apoptosis by up-regulating pro-apoptotic gene expression. We have previously demonstrated that rats treated with GC develop low formation osteoporosis (bone histomorphometry and DEXA) and skeletal fragility (breaking strength) that were largely prevented by co-treatment with vanadate. We report here that vertebrae from rats treated with 3·5 mg/kg per day methylprednisolone for 9 weeks showed increased incidence of terminal deoxynucleotidyl transferase-mediated biotin-dUTP nick end-labelling-positive apoptotic osteocytes, which was reduced by vanadate co-treatment. We conclude that vanadate prevents GC-induced

  15. cAMP prevents TNF-induced apoptosis through inhibiting DISC complex formation in rat hepatocytes

    SciTech Connect

    Bhattacharjee, Rajesh; Xiang, Wenpei; Wang, Yinna; Zhang, Xiaoying

    2012-06-22

    that cAMP exerts its affect at the proximal level of TNF signaling by inhibiting the formation of the DISC complex upon the binding of TNF to TNFR1. In conclusion, our study shows that cAMP prevents TNF + ActD-induced apoptosis in rat hepatocytes by inhibiting DISC complex formation.

  16. Sharpin prevents skin inflammation by inhibiting TNFR1-induced keratinocyte apoptosis

    PubMed Central

    Kumari, Snehlata; Redouane, Younes; Lopez-Mosqueda, Jaime; Shiraishi, Ryoko; Romanowska, Malgorzata; Lutzmayer, Stefan; Kuiper, Jan; Martinez, Conception; Dikic, Ivan; Pasparakis, Manolis; Ikeda, Fumiyo

    2014-01-01

    Linear Ubiquitin chain Assembly Complex (LUBAC) is an E3 ligase complex that generates linear ubiquitin chains and is important for tumour necrosis factor (TNF) signaling activation. Mice lacking Sharpin, a critical subunit of LUBAC, spontaneously develop inflammatory lesions in the skin and other organs. Here we show that TNF receptor 1 (TNFR1)-associated death domain (TRADD)-dependent TNFR1 signaling in epidermal keratinocytes drives skin inflammation in Sharpin-deficient mice. Epidermis-restricted ablation of Fas-associated protein with death domain (FADD) combined with receptor-interacting protein kinase 3 (RIPK3) deficiency fully prevented skin inflammation, while single RIPK3 deficiency only delayed and partly ameliorated lesion development in Sharpin-deficient mice, showing that inflammation is primarily driven by TRADD- and FADD-dependent keratinocyte apoptosis while necroptosis plays a minor role. At the cellular level, Sharpin deficiency sensitized primary murine keratinocytes, human keratinocytes, and mouse embryonic fibroblasts to TNF-induced apoptosis. Depletion of FADD or TRADD in Sharpin-deficient HaCaT cells suppressed TNF-induced apoptosis, indicating the importance of FADD and TRADD in Sharpin-dependent anti-apoptosis signaling in keratinocytes. DOI: http://dx.doi.org/10.7554/eLife.03422.001 PMID:25443631

  17. Nicotine prevents the apoptosis induced by menadione in human lung cancer cells

    SciTech Connect

    Zhang Tao; Lu Heng; Shang Xuan; Tian Yihao; Zheng Congyi; Wang Shiwen; Cheng Hanhua . E-mail: hhcheng@whu.edu.cn; Zhou Rongjia . E-mail: rjzhou@whu.edu.cn

    2006-04-14

    Approximately 50% of long-term cigarette smokers die prematurely from the adverse effects of smoking, including on lung cancer and other illnesses. Nicotine is a main component in tobacco and has been implicated as a potential factor in the pathogenesis of human lung cancer. However, the mechanism of nicotine action in the development of lung cancer remains largely unknown. In the present study, we designed a nicotine-apoptosis system, by pre-treatment of nicotine making lung cancer cell A549 to be in a physiological nicotine environment, and observed that nicotine promoted cell proliferation and prevented the menadione-induced apoptosis, and exerts its role of anti-apoptosis by shift of apoptotic stage induced by menadione from late apoptotic stage to early apoptotic stage, in which NF-{kappa}B was up-regulated. Interference analysis of NF-{kappa}B in A549 cells showed that knock down of NF-{kappa}B resulted in apoptosis promotion and counteracted the protective effect of nicotine. The findings suggest that nicotine has potential effect in lung cancer genesis, especially in patients with undetectable early tumor development and development of specific NF-{kappa}B inhibitors would represent a potentially exciting new pharmacotherapy for tobacco-related lung cancer.

  18. Anethole prevents hydrogen peroxide-induced apoptosis and collagen metabolism alterations in human skin fibroblasts.

    PubMed

    Galicka, Anna; Krętowski, Rafał; Nazaruk, Jolanta; Cechowska-Pasko, Marzanna

    2014-09-01

    The collagen metabolism alterations triggered by reactive oxygen species are involved in the development of various connective tissue diseases and skin aging. This study was designed to examine whether (E)-anethole possesses a protective effect on H2O2-induced alterations in collagen metabolism as well as whether it can prevent apoptosis in human skin fibroblasts. In cells treated with 300 µM H₂O₂, a decrease in collagen biosynthesis of 54% was observed. Pretreatment of cells with 0.5 µM anethole for 1 h completely prevented this alteration. Changes at the protein level positively correlated with alterations of type I collagen mRNA expression. We have shown that H2O2 caused increase in the activity of MMP-2 and MMP-9 as well as that an increase in MMP-2 activity can contribute to the 8% decrease in the amount of collagen secreted into the medium. The most efficient suppression of these changes was observed in the presence of 0.5 µM of anethole. At 10 µM, in addition to suppression, an inhibitory effect of anethole on MMP-9 activity was documented. Additionally, the 60% H₂O₂-induced decrease in cell viability was suppressed by 1 µM of anethole and a 4-fold increase in cell apoptosis was suppressed by 0.5 µM of anethole. Our results suggest that anethole, which is a small lipophilic and non-toxic molecule with the ability to prevent H₂O₂-induced collagen metabolism alterations and apoptosis in human skin fibroblasts, would prove useful in the development of effective agents in pharmacotherapy of oxidative stress-related skin diseases.

  19. Celecoxib prevents curcumin-induced apoptosis in a hematopoietic cancer cell model.

    PubMed

    Sobolewski, Cyril; Muller, Florian; Cerella, Claudia; Dicato, Mario; Diederich, Marc

    2015-10-01

    Molecules targeting pro-inflammatory pathways have demonstrated beneficial effects in cancer treatment. More recently, combination of natural and synthetic anti-inflammatory drugs was suggested as an appealing strategy to inhibit tumor growth. Herein, we show that curcumin, a polyphenol from Curcuma longa and celecoxib induce apoptosis in hematopoietic cancer cell lines (Hel, Jurkat, K562, Raji, and U937). Further investigations on the most sensitive cell line, U937, indicated that these effects were tightly associated with an accumulation of the cells in S and G2/M for curcumin and in G0/G1 phase of cell cycle for celecoxib, respectively. The effect of celecoxib on cell cycle is associated with an induction of p27 and the down-regulation of cyclin D1. However, in the case of combination experiments, the pretreatment of U937 cells with celecoxib at non-apoptogenic concentrations counteracted curcumin-induced apoptosis. We found that this effect correlated with the prevention of the accumulation in S and G2/M phase of cell cycle induced by curcumin. Similar results have been obtained when celecoxib and curcumin were co-administrated at the same time. Overall our data suggest that this natural and synthetic drug combination is detrimental for cell death induction.

  20. Flos Puerariae Extract Prevents Myocardial Apoptosis via Attenuation Oxidative Stress in Streptozotocin-Induced Diabetic Mice

    PubMed Central

    Guo, Shuang; Cheng, Hongke; Wu, Jiliang; Liu, Chao

    2014-01-01

    Background Diabetic cardiomyopathy (DCM) suggests a direct cellular insult to myocardium. Apoptosis is considered as one of the hallmarks of DCM. Oxidative stress plays a key role in the pathogenesis of DCM. In this study, we explored the prevention of myocardial apoptosis by crude extract from Flos Puerariae (FPE) in experimental diabetic mice. Methods Experimental diabetic model was induced by intraperitoneally injection of streptozotocin (STZ, 50 mg/kg/day) for five consecutive days in C57BL/6J mice. FPE (100, 200 mg/kg) was orally administrated once a day for ten weeks. Cardiac structure changes, apoptosis, superoxide production, NADPH oxidase subunits expression (gp91phox, p47phox, and p67phox), and related regulatory factors were assessed in the heart of mice. Results Diabetic mice were characterized by high blood glucose (≥11.1 mmol/L) and reduced body weight. In the end of the experiment, aberrant myofilament structure, as well as TUNEL positive cardiac cells coupled with increased Bax/Bcl-2 ratio and Caspase-3 expression was found in diabetic mice. Moreover, ROS formation, the ratio of NADP+/NADPH and NADPH oxidase subunits expression of gp91phox and p47phox, lipid peroxidation level was significantly increased, while antioxidant enzyme SOD and GSH-Px activity were reduced in the myocardial tissue of diabetic mice. In contrast, treatment with FPE resulted in a normalized glucose and weight profile. FPE administration also preserved myocardial structure and reduced apoptotic cardiac cell death in diabetic mice. The elevated markers of oxidative stress were significantly reversed by FPE supplementation. Further, FPE treatment markedly inhibited the increased Bax/Bcl-2 ratio and Caspase-3 expression, as well as suppressed JNK and P38 MAPK activation in the heart of diabetic mice. Conclusions Our data demonstrate for the first time that FPE may have therapeutic potential for STZ-induced diabetic cardiomyopathy through preventing myocardial apoptosis via

  1. Heat stress prevents lipopolysaccharide-induced apoptosis in pulmonary microvascular endothelial cells by blocking calpain/p38 MAPK signalling

    PubMed Central

    Liu, Zhi-feng; Zheng, Dong; Fan, Guo-chang; Peng, Tianqing; Su, Lei

    2016-01-01

    Pulmonary microvascular endothelial cells (PMECs) injury including apoptosis plays an important role in the pathogenesis of acute lung injury during sepsis. Our recent study has demonstrated that calpain activation contributes to apoptosis in PMECs under septic conditions. This study investigated how calpain activation mediated apoptosis and whether heat stress regulated calpain activation in lipopolysaccharides (LPS)-stimulated PMECs. In cultured mouse primary PMECs, incubation with LPS (1 µg/ml, 24 h) increased active caspase-3 fragments and DNA fragmentation, indicative of apoptosis. These effects of LPS were abrogated by pre-treatment with heat stress (43 °C for 2 h). LPS also induced calpain activation and increased phosphorylation of p38 MAPK. Inhibition of calpain and p38 MAPK prevented apoptosis induced by LPS. Furthermore, inhibition of calpain blocked p38 MAPK phosphorylation in LPS-stimulated PMECs. Notably, heat stress decreased the protein levels of calpain-1/2 and calpain activities, and blocked p38 MAPK phosphorylation in response to LPS. Additionally, forced up-regulation of calpain-1 or calpain-2 sufficiently induced p38 MAPK phosphorylation and apoptosis in PMECs, both of which were inhibited by heat stress. In conclusion, heat stress prevents LPS-induced apoptosis in PMECs. This effect of heat stress is associated with down-regulation of calpain expression and activation, and subsequent blockage of p38 MAPK activation in response to LPS. Thus, blocking calpain/p38 MAPK pathway may be a novel mechanism underlying heat stress-mediated inhibition of apoptosis in LPS-stimulated endothelial cells. PMID:27325431

  2. Chloride channel protein 2 prevents glutamate-induced apoptosis in retinal ganglion cells

    PubMed Central

    Bi, Miao-Miao; Hong, Sen; Ma, Ling-Jun; Zhou, Hong-Yan; Lu, Jia; Zhao, Jing; Zheng, Ya-Juan

    2016-01-01

    Objective(s): The purpose of this study was to investigate the role of chloride channel protein 2 (ClC-2) in glutamate-induced apoptosis in the retinal ganglion cell line (RGC-5). Materials and Methods: RGC-5 cells were treated with 1 mM glutamate for 24 hr. The expression of ClC-2, Bax, and Bcl-2 was detected by western blot analysis. Cell survival and apoptosis were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry assays, respectively. Caspase-3 and -9 activities were determined by a colorimetric assay. The roles of ClC-2 in glutamate-induced apoptosis were examined by using ClC-2 complementary deoxyribonucleic acid (cDNA) and small inference ribonucleic acid (RNA) transfection technology. Results: Overexpression of ClC-2 in RGC-5 cells significantly decreased glutamate-induced apoptosis and increased cell viability, whereas silencing of ClC-2 with short hairpin (sh) RNA produced opposite effects. ClC-2 overexpression increased the expression of Bcl-2, decreased the expression of Bax, and decreased caspase-3 and -9 activation in RGC-5 cells treated with glutamate, but silencing of ClC-2 produced opposite effects. Conclusion: Our data suggest that ClC-2 chloride channels might play a protective role in glutamate-induced apoptosis in retinal ganglion cells via the mitochondria-dependent apoptosis pathway.

  3. Chloride channel protein 2 prevents glutamate-induced apoptosis in retinal ganglion cells

    PubMed Central

    Bi, Miao-Miao; Hong, Sen; Ma, Ling-Jun; Zhou, Hong-Yan; Lu, Jia; Zhao, Jing; Zheng, Ya-Juan

    2016-01-01

    Objective(s): The purpose of this study was to investigate the role of chloride channel protein 2 (ClC-2) in glutamate-induced apoptosis in the retinal ganglion cell line (RGC-5). Materials and Methods: RGC-5 cells were treated with 1 mM glutamate for 24 hr. The expression of ClC-2, Bax, and Bcl-2 was detected by western blot analysis. Cell survival and apoptosis were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry assays, respectively. Caspase-3 and -9 activities were determined by a colorimetric assay. The roles of ClC-2 in glutamate-induced apoptosis were examined by using ClC-2 complementary deoxyribonucleic acid (cDNA) and small inference ribonucleic acid (RNA) transfection technology. Results: Overexpression of ClC-2 in RGC-5 cells significantly decreased glutamate-induced apoptosis and increased cell viability, whereas silencing of ClC-2 with short hairpin (sh) RNA produced opposite effects. ClC-2 overexpression increased the expression of Bcl-2, decreased the expression of Bax, and decreased caspase-3 and -9 activation in RGC-5 cells treated with glutamate, but silencing of ClC-2 produced opposite effects. Conclusion: Our data suggest that ClC-2 chloride channels might play a protective role in glutamate-induced apoptosis in retinal ganglion cells via the mitochondria-dependent apoptosis pathway. PMID:27635193

  4. Folic Acid Protected Neural Cells Against Aluminum-Maltolate-Induced Apoptosis by Preventing miR-19 Downregulation.

    PubMed

    Zhu, Mingming; Li, Bingfei; Ma, Xiao; Huang, Cong; Wu, Rui; Zhu, Weiwei; Li, Xiaoting; Liang, Zhaofeng; Deng, Feifei; Zhu, Jianyun; Xie, Wei; Yang, Xue; Jiang, Ye; Wang, Shijia; Wu, Jieshu; Geng, Shanshan; Xie, Chunfeng; Zhong, Caiyun; Liu, Haiyan

    2016-08-01

    Aluminum (Al)-induced apoptosis is considered as the major cause of its neurotoxicity. Folic acid possesses neuroprotective function by preventing neural cell apoptosis. microRNAs (miRNAs) are important regulators of gene expression participating in cellular processes. As a key component of the miR-17-92 cluster, miR-19 is implicated in regulating apoptotic process, while its role in the neuroprotective effect of folic acid has not been investigated. The present study aimed to investigate the potential involvement and function of miR-19 in the protective action of folic acid against Al-induced neural cell apoptosis. Human SH-SY5Y cells were treated with Al-maltolate (Al-malt) in the presence or absence of folic acid. Results showed that Al-malt-induced apoptosis of SH-SY5Y cells was effectively prevented by folic acid. Al-malt suppressed the expression of miR-19a/19b, along with alterations of miR-19 related apoptotic proteins including PTEN, p-AKT, p53, Bax, Bcl-2, caspase 9 and caspase 3; and these effects were ameliorated by folic acid. miR-19 inhibitor alone induced apoptosis of SH-SY5Y cells. Combination treatment of folic acid and miR-19 inhibitor diminished the neuroprotective effect of folic acid. These findings demonstrated that folic acid protected neuronal cells against Al-malt-induced apoptosis by preventing the downregulation of miR-19 and modulation of miR-19 related downstream PTEN/AKT/p53 pathway.

  5. Hydrogen sulfide prevents Abeta-induced neuronal apoptosis by attenuating mitochondrial translocation of PTEN.

    PubMed

    Cui, Weigang; Zhang, Yinghua; Yang, Chenxi; Sun, Yiyuan; Zhang, Min; Wang, Songtao

    2016-06-14

    Neuronal cell apoptosis is an important pathological change in Alzheimer's disease (AD). Hydrogen sulfide (H(2)S) is known to be a novel gaseous signaling molecule and a cytoprotectant in many diseases including AD. However, the molecular mechanism of the antiapoptosis activity of H(2)S in AD is not yet fully understood. The aim of the present study is to evaluate the inhibitory effects of H(2)S on Abeta (Aβ)-induced apoptosis and the molecular mechanisms underlying primary neuron cells. Our results showed that sodium hydrosulfide (NaHS), a donor of H(2)S, significantly ameliorated Aβ-induced cell apoptosis. NaHS also reversed the Aβ-induced translocation of the phosphatase and tensin homologs deleted on chromosome 10 (PTEN) from the cytosol to the mitochondria. Furthermore, H(2)S increased the level of p-AKT/AKT significantly. Interestingly, the antiapoptosis effects of H(2)S were blocked down by specific PI3K/AKT inhibitor wortmannin. In conclusion, these data indicate that H(2)S inhibits Aβ-induced neuronal apoptosis by attenuating mitochondrial translocation of PTEN and that activation of PI3K/AKT signaling pathway plays a critical role in H(2)S-mediated neuronal protection. Our findings provide a novel route into the molecular mechanisms of neuronal apoptosis in AD.

  6. Comprehensive Suppression of All Apoptosis-Induced Proliferation Pathways as a Proposed Approach to Colorectal Cancer Prevention and Therapy

    PubMed Central

    Bordonaro, Michael; Drago, Eric; Atamna, Wafa; Lazarova, Darina L.

    2014-01-01

    Mutations in the WNT/beta-catenin pathway are present in the majority of all sporadic colorectal cancers (CRCs), and histone deacetylase inhibitors induce apoptosis in CRC cells with such mutations. This apoptosis is counteracted by (1) the signaling heterogeneity of CRC cell populations, and (2) the survival pathways induced by mitogens secreted from apoptotic cells. The phenomena of signaling heterogeneity and apoptosis-induced survival constitute the immediate mechanisms of resistance to histone deacetylase inhibitors, and probably other chemotherapeutic agents. We explored the strategy of augmenting CRC cell death by inhibiting all survival pathways induced by the pro-apoptotic agent LBH589, a histone deacetylase inhibitor: AKT, JAK/STAT, and ERK signaling. The apoptosis-enhancing ability of a cocktail of synthetic inhibitors of proliferation was compared to the effects of the natural product propolis. We utilized colorectal adenoma, drug-sensitive and drug-resistant colorectal carcinoma cells to evaluate the apoptotic potential of the combination treatments. The results suggest that an effective approach to CRC combination therapy is to combine apoptosis-inducing drugs (e.g., histone deacetylase inhibitors, such as LBH589) with agents that suppress all compensatory survival pathways induced during apoptosis (such as the cocktail of inhibitors of apoptosis-associated proliferation). The same paradigm can be applied to a CRC prevention approach, as the apoptotic effect of butyrate, a diet-derived histone deacetylase inhibitor, is augmented by other dietary agents that modulate survival pathways (e.g., propolis and coffee extract). Thus, dietary supplements composed by fermentable fiber, propolis, and coffee extract may effectively counteract neoplastic growth in the colon. PMID:25500581

  7. Glucagon-like peptide-1 prevents methylglyoxal-induced apoptosis of beta cells through improving mitochondrial function and suppressing prolonged AMPK activation

    PubMed Central

    Chang, Tien-Jyun; Tseng, Hsing-Chi; Liu, Meng-Wei; Chang, Yi-Cheng; Hsieh, Meng-Lun; Chuang, Lee-Ming

    2016-01-01

    Accumulation of methylglyoxal (MG) contributes to glucotoxicity and mediates beta cell apoptosis. The molecular mechanism by which GLP-1 protects MG-induced beta cell apoptosis remains unclear. Metformin is a first-line drug for treating type 2 diabetes associated with AMPK activation. However, whether metformin prevents MG-induced beta cell apoptosis is controversial. Here, we explored the signaling pathway involved in the anti-apoptotic effect of GLP-1, and investigated whether metformin had an anti-apoptotic effect on beta cells. MG treatment induced apoptosis of beta cells, impaired mitochondrial function, and prolonged activation of AMP-dependent protein kinase (AMPK). The MG-induced pro-apoptotic effects were abolished by an AMPK inhibitor. Pretreatment of GLP-1 reversed MG-induced apoptosis, and mitochondrial dysfunction, and suppressed prolonged AMPK activation. Pretreatment of GLP-1 reversed AMPK activator 5-aminoimidazole-4-carboxamide riboside (AICAR)-induced apoptosis, and suppressed prolonged AMPK activation. However, metformin neither leads to beta cell apoptosis nor ameliorates MG-induced beta cell apoptosis. In parallel, GLP-1 also prevents MG-induced beta cell apoptosis through PKA and PI3K-dependent pathway. In conclusion, these data indicates GLP-1 but not metformin protects MG-induced beta cell apoptosis through improving mitochondrial function, and alleviating the prolonged AMPK activation. Whether adding GLP-1 to metformin provides better beta cell survival and delays disease progression remains to be validated. PMID:26997114

  8. Glucagon-like peptide-1 prevents methylglyoxal-induced apoptosis of beta cells through improving mitochondrial function and suppressing prolonged AMPK activation.

    PubMed

    Chang, Tien-Jyun; Tseng, Hsing-Chi; Liu, Meng-Wei; Chang, Yi-Cheng; Hsieh, Meng-Lun; Chuang, Lee-Ming

    2016-01-01

    Accumulation of methylglyoxal (MG) contributes to glucotoxicity and mediates beta cell apoptosis. The molecular mechanism by which GLP-1 protects MG-induced beta cell apoptosis remains unclear. Metformin is a first-line drug for treating type 2 diabetes associated with AMPK activation. However, whether metformin prevents MG-induced beta cell apoptosis is controversial. Here, we explored the signaling pathway involved in the anti-apoptotic effect of GLP-1, and investigated whether metformin had an anti-apoptotic effect on beta cells. MG treatment induced apoptosis of beta cells, impaired mitochondrial function, and prolonged activation of AMP-dependent protein kinase (AMPK). The MG-induced pro-apoptotic effects were abolished by an AMPK inhibitor. Pretreatment of GLP-1 reversed MG-induced apoptosis, and mitochondrial dysfunction, and suppressed prolonged AMPK activation. Pretreatment of GLP-1 reversed AMPK activator 5-aminoimidazole-4-carboxamide riboside (AICAR)-induced apoptosis, and suppressed prolonged AMPK activation. However, metformin neither leads to beta cell apoptosis nor ameliorates MG-induced beta cell apoptosis. In parallel, GLP-1 also prevents MG-induced beta cell apoptosis through PKA and PI3K-dependent pathway. In conclusion, these data indicates GLP-1 but not metformin protects MG-induced beta cell apoptosis through improving mitochondrial function, and alleviating the prolonged AMPK activation. Whether adding GLP-1 to metformin provides better beta cell survival and delays disease progression remains to be validated. PMID:26997114

  9. Ursodeoxycholic acid and 4-phenylbutyrate prevent endoplasmic reticulum stress-induced podocyte apoptosis in diabetic nephropathy.

    PubMed

    Cao, Ai-Li; Wang, Li; Chen, Xia; Wang, Yun-Man; Guo, Heng-Jiang; Chu, Shuang; Liu, Cheng; Zhang, Xue-Mei; Peng, Wen

    2016-06-01

    Endoplasmic reticulum (ER) stress, resulting from the accumulation of misfolded and/or unfolded proteins in ER membranes, is involved in the pathogenesis of diabetic nephropathy (DN). The aim of this study was to investigate the role of ER stress inhibitors ursodeoxycholic acid (UDCA) and 4-phenylbutyrate (4-PBA) in the treatment of DN in db/db mice. Findings have revealed that diabetic db/db mice were more hyperglycemic than their non-diabetic controls, and exhibited a marked increase in body weight, water intake, urine volume, fasting plasma glucose, systolic blood pressure, glucose and insulin tolerance. UDCA (40 mg/kg/day) or 4-PBA (100 mg/kg/day) treatment for 12 weeks resulted in an improvement in these biochemical and physical parameters. Moreover, UDCA or 4-PBA intervention markedly decreased urinary albuminuria and attenuated mesangial expansion in diabetic db/db mice, compared with db/db mice treated with vehicle. These beneficial effects of UDCA or 4-PBA on DN were associated with the inhibition of ER stress, as evidenced by the decreased expression of BiP, phospho-IRE1α, phospho-eIF2α, CHOP, ATF-6 and spliced X-box binding protein-1 in vitro and in vivo. UDCA or 4-PBA prevented hyperglycemia-induced or high glucose (HG)-induced apoptosis in podocytes in vivo and in vitro via the inhibition of caspase-3 and caspase-12 activation. Autophagy deficiency was also seen in glomeruli in diabetic mice and HG-incubated podocytes, exhibiting decreased expression of LC3B and Beclin-1, which could be restored by UDCA or 4-PBA treatment. Taken together, our results have revealed an important role of ER stress in the development of DN, and UDCA or 4-PBA treatment may be a potential novel therapeutic approach for the treatment of DN. PMID:26999661

  10. Indigofera oblongifolia Prevents Lead Acetate-Induced Hepatotoxicity, Oxidative Stress, Fibrosis and Apoptosis in Rats

    PubMed Central

    Abdel Moneim, Ahmed E.

    2016-01-01

    The current study was aimed to evaluate the preventive effects of Indigofera oblongifolia leaf extract (IOLE) on lead acetate (PbAc)-induced hepatotoxicity in adult male Wistar rats. PbAc was intraperitoneally injected at a dose of 20 mg/kg body weight for 5 days alone or in combination with the IOLE (100 mg/kg). Liver lead concentration and oxidative stress markers such as lipid peroxidation, hydrogen peroxide, nitric oxide, and glutathione content were investigated in addition to the enzymatic antioxidant activities. PbAc injection caused a significant elevation in the liver function parameters, lead level, lipid peroxidation, hydrogen peroxide, and nitric oxide, with a concomitant decline in the glutathione content compared with the control, accompanied by a significant inhibition of antioxidant enzyme activities. The induction of oxidative stress, lead accumulation, and histological alterations in the liver were successfully minimized by pre-administration of IOLE. In addition, the PbAc group showed increase in the levels of Bax, caspase-3, and matrix metalloproteinase-9 proteins, while the expression of Bcl-2 protein was decreased. Prior administration of IOLE significantly mitigated apoptosis and fibrosis in the liver. Finally, the major components in I. oblongifolia extract were identified as polyphenols, flavonoids, and organic acids using liquid chromatography coupled mass spectroscopy. Thus, the findings of the current study revealed that I. oblongifolia had protective, anti-fibrotic, antioxidant, and anti-apoptotic activities on PbAc-induced hepatotoxicity. The beneficial effects of I. oblongifolia were in part mediated by Nrf2/HO-1 pathway. PMID:27391413

  11. Crocin prevents sesamol-induced oxidative stress and apoptosis in human platelets.

    PubMed

    Thushara, Ram M; Hemshekhar, Mahadevappa; Paul, Manoj; Shanmuga Sundaram, Mahalingam; Shankar, Rohith L; Kemparaju, Kempaiah; Girish, Kesturu S

    2014-10-01

    Recent studies have reported the platelet proapoptotic propensity of plant-derived molecules such as, resveratrol, thymoquinone, andrographolide and gossypol. Meanwhile, there were also reports of phytochemicals such as cinnamtannin B1, which shows antiapoptotic effect towards platelets. Platelets are mainly involved in hemostasis, thrombosis and wound healing. However, altered platelet functions can have serious pathological outcomes that include cardiovascular diseases. Platelets are sensitive to external and internal stimuli including therapeutic and dietary components. The anuclear platelets do undergo apoptosis via mitochondrial pathway. However, exaggerated rate of platelet apoptosis could lead to thrombocytopenia and other bleeding disorders. The present study deals with ameliorative efficacy of crocin on sesamol-induced platelet apoptosis. The antiapoptotic property of crocin and the proapoptotic tendency of sesamol in platelets were previously demonstrated. Therefore, it was interesting to see how these two compounds would interact and wield their effects on human platelets. Crocin effectively inhibited sesamol-induced oxidative stress on platelets, which was evidenced by the measurement of endogenously generated reactive oxygen species, particularly hydrogen peroxide, and changes in thiol levels. Further, crocin abrogated sesamol-induced biochemical events of apoptosis in platelets, which include intracellular calcium mobilization, changes in mitochondrial membrane integrity, cytochrome c release, caspase activity and phosphatidylserine externalization. Even though sesamol has proapoptotic effects on platelets, its anti-platelet activity cannot be neglected. Thus, the study proposes that sesamol could be supplemented with crocin, an approach that could not only abolish the toxic effects of sesamol on platelets, but also enhance the quality of treatment due to their synergistic action. PMID:24705676

  12. Crocin prevents sesamol-induced oxidative stress and apoptosis in human platelets.

    PubMed

    Thushara, Ram M; Hemshekhar, Mahadevappa; Paul, Manoj; Shanmuga Sundaram, Mahalingam; Shankar, Rohith L; Kemparaju, Kempaiah; Girish, Kesturu S

    2014-10-01

    Recent studies have reported the platelet proapoptotic propensity of plant-derived molecules such as, resveratrol, thymoquinone, andrographolide and gossypol. Meanwhile, there were also reports of phytochemicals such as cinnamtannin B1, which shows antiapoptotic effect towards platelets. Platelets are mainly involved in hemostasis, thrombosis and wound healing. However, altered platelet functions can have serious pathological outcomes that include cardiovascular diseases. Platelets are sensitive to external and internal stimuli including therapeutic and dietary components. The anuclear platelets do undergo apoptosis via mitochondrial pathway. However, exaggerated rate of platelet apoptosis could lead to thrombocytopenia and other bleeding disorders. The present study deals with ameliorative efficacy of crocin on sesamol-induced platelet apoptosis. The antiapoptotic property of crocin and the proapoptotic tendency of sesamol in platelets were previously demonstrated. Therefore, it was interesting to see how these two compounds would interact and wield their effects on human platelets. Crocin effectively inhibited sesamol-induced oxidative stress on platelets, which was evidenced by the measurement of endogenously generated reactive oxygen species, particularly hydrogen peroxide, and changes in thiol levels. Further, crocin abrogated sesamol-induced biochemical events of apoptosis in platelets, which include intracellular calcium mobilization, changes in mitochondrial membrane integrity, cytochrome c release, caspase activity and phosphatidylserine externalization. Even though sesamol has proapoptotic effects on platelets, its anti-platelet activity cannot be neglected. Thus, the study proposes that sesamol could be supplemented with crocin, an approach that could not only abolish the toxic effects of sesamol on platelets, but also enhance the quality of treatment due to their synergistic action.

  13. Lipopolysaccharide prevents valproic acid-induced apoptosis via activation of nuclear factor-κB and inhibition of p53 activation.

    PubMed

    Tsolmongyn, Bilegtsaikhan; Koide, Naoki; Odkhuu, Erdenezaya; Haque, Abedul; Naiki, Yoshikazu; Komatsu, Takayuki; Yoshida, Tomoaki; Yokochi, Takashi

    2013-04-01

    The effect of lipopolysaccharide (LPS) on valproic acid (VPA)-induced cell death was examined by using mouse RAW 264.7 macrophage cells. LPS inhibited the activation of caspase 3 and poly (ADP-ribose) polymerase and prevented VPA-induced apoptosis. LPS inhibited VPA-induced p53 activation and pifithrin-α as a p53 inhibitor as well as LPS prevented VPA-induced apoptosis. LPS abolished the increase of Bax/Bcl-2 ratio, which is a critical indicator of p53-mediated mitochondrial damage, in response to VPA. The nuclear factor (NF)-κB inhibitors, Bay 11-7082 and parthenolide, abolished the preventive action of LPS on VPA-induced apoptosis. A series of toll-like receptor ligands, Pam3CSK4, poly I:C, and CpG DNA as well as LPS prevented VPA-induced apoptosis. Taken together, LPS was suggested to prevent VPA-induced apoptosis via activation of anti-apoptotic NF-κB and inhibition of pro-apoptotic p53 activation. The detailed inhibitory mechanism of VPA-induced apoptosis by LPS is discussed.

  14. Lipopolysaccharide prevents valproic acid-induced apoptosis via activation of nuclear factor-κB and inhibition of p53 activation.

    PubMed

    Tsolmongyn, Bilegtsaikhan; Koide, Naoki; Odkhuu, Erdenezaya; Haque, Abedul; Naiki, Yoshikazu; Komatsu, Takayuki; Yoshida, Tomoaki; Yokochi, Takashi

    2013-04-01

    The effect of lipopolysaccharide (LPS) on valproic acid (VPA)-induced cell death was examined by using mouse RAW 264.7 macrophage cells. LPS inhibited the activation of caspase 3 and poly (ADP-ribose) polymerase and prevented VPA-induced apoptosis. LPS inhibited VPA-induced p53 activation and pifithrin-α as a p53 inhibitor as well as LPS prevented VPA-induced apoptosis. LPS abolished the increase of Bax/Bcl-2 ratio, which is a critical indicator of p53-mediated mitochondrial damage, in response to VPA. The nuclear factor (NF)-κB inhibitors, Bay 11-7082 and parthenolide, abolished the preventive action of LPS on VPA-induced apoptosis. A series of toll-like receptor ligands, Pam3CSK4, poly I:C, and CpG DNA as well as LPS prevented VPA-induced apoptosis. Taken together, LPS was suggested to prevent VPA-induced apoptosis via activation of anti-apoptotic NF-κB and inhibition of pro-apoptotic p53 activation. The detailed inhibitory mechanism of VPA-induced apoptosis by LPS is discussed. PMID:23770718

  15. Compound 49b Prevents Diabetes-Induced Apoptosis through Increased IGFBP-3 Levels

    PubMed Central

    Zhang, Qiuhua; Guy, Kimberly; Pagadala, Jayaprakash; Jiang, Youde; Walker, Robert J; Liu, Luhong; Soderland, Carl; Kern, Timothy S; Ferry, Robert; He, Hui; Yates, C. Ryan; Miller, Duane D; Steinle, Jena J

    2012-01-01

    Purpose. To determine whether Compound 49b, a novel PKA-activating drug, can prevent diabetic-like changes in the rat retina through increased insulin-like growth factor binding protein-3 (IGFBP-3) levels. Methods. For the cell culture studies, we used both human retinal endothelial cells (REC) and retinal Müller cells in either 5 mM (normal) or 25 mM (high) glucose. Cells were treated with 50 nM Compound 49b alone of following treatment with protein kinase A (PKA) siRNA or IGFBP-3 siRNA. Western blotting and ELISA analyses were done to verify PKA and IGFBP-3 knockdown, as well as to measure apoptotic markers. For animal studies, we used streptozotocin-treated rats after 2 and 8 months of diabetes. Some rats were treated topically with 1 mM Compound 49b. Analyses were done for retinal thickness, cell numbers in the ganglion cell layer, pericyte ghosts, and numbers of degenerate capillaries, as well as electroretinogram and heart morphology. Results. Compound 49b requires active PKA and IGFBP-3 to prevent apoptosis of REC. Compound 49b significantly reduced the numbers of degenerate capillaries and pericyte ghosts, while preventing the decreased retinal thickness and loss of cells in the ganglion cell layer. Compound 49b maintained a normal electroretinogram, with no changes in blood pressure, intraocular pressure, or heart morphological changes. Conclusions. Topical Compound 49b is able to prevent diabetic-like changes in the rat retina, without producing systemic changes. Compound 49b is able to prevent REC apoptosis through increasing IGFBP-3 levels, which are reduced in response to hyperglycemia. PMID:22467575

  16. Sulforaphane prevents microcystin-LR-induced oxidative damage and apoptosis in BALB/c mice

    SciTech Connect

    Sun Xiaoyun; Mi Lixin; Liu Jin; Song Lirong; Chung Funglung; Gan Nanqin

    2011-08-15

    Microcystins (MCs), the products of blooming algae Microcystis, are waterborne environmental toxins that have been implicated in the development of liver cancer, necrosis, and even fatal intrahepatic bleeding. Alternative protective approaches in addition to complete removal of MCs in drinking water are urgently needed. In our previous work, we found that sulforaphane (SFN) protects against microcystin-LR (MC-LR)-induced cytotoxicity by activating the NF-E2-related factor 2 (Nrf2)-mediated defensive response in human hepatoma (HepG2) and NIH 3T3 cells. The purpose of this study was to investigate and confirm efficacy the SFN-induced multi-mechanistic defense system against MC-induced hepatotoxicity in an animal model. We report that SFN protected against MC-LR-induced liver damage and animal death at a nontoxic and physiologically relevant dose in BALB/c mice. The protection by SFN included activities of anti-cytochrome P450 induction, anti-oxidation, anti-inflammation, and anti-apoptosis. Our results suggest that SFN may protect mice against MC-induced hepatotoxicity. This raises the possibility of a similar protective effect in human populations, particularly in developing countries where freshwaters are polluted by blooming algae. - Graphical abstract: Display Omitted Research Highlights: > SFN protected against MC-LR-induced liver damage and animal death in BALB/c mice. > The dose of SFN is at a nontoxic and physiologically relevant dose. > The protection included activities of anti-oxidation, anti-inflammation, and anti-apoptosis. > SFN may protect mice against MC-induced hepatotoxicity.

  17. Protocatechuic Acid Prevents oxLDL-Induced Apoptosis by Activating JNK/Nrf2 Survival Signals in Macrophages

    PubMed Central

    Varì, Rosaria; Scazzocchio, Beatrice; Santangelo, Carmela; Filesi, Carmelina; Galvano, Fabio; D'Archivio, Massimo; Masella, Roberta; Giovannini, Claudio

    2015-01-01

    Protocatechuic acid (PCA), one of the main metabolites of complex polyphenols, exerts numerous biological activities including antiapoptotic, anti-inflammatory, and antiatherosclerotic effects. Oxidised LDL have atherogenic properties by damaging arterial wall cells and inducing p53-dependent apoptosis in macrophages. This study was aimed at defining the molecular mechanism responsible for the protective effects of PCA against oxidative and proapoptotic damage exerted by oxLDL in J774 A.1 macrophages. We found that the presence of PCA in cells treated with oxLDL completely inhibited the p53-dependent apoptosis induced by oxLDL. PCA decreased oxLDL-induced ROS overproduction and in particular prevented the early increase of ROS. This decrease seemed to be the main signal responsible for maintaining the intracellular redox homeostasis hindering the activation of p53 induced by ROS, p38MAPK, and PKCδ. Consequently the overexpression of the proapoptotic p53-target genes such as p66Shc protein did not occur. Finally, we demonstrated that PCA induced the activation of JNK, which, in turn, determined the increase of nuclear Nrf2, leading to inhibition of the early ROS overproduction. We concluded that the antiapoptotic mechanism of PCA was most likely related to the activation of the JNK-mediated survival signals that strengthen the cellular antioxidant defences rather than to the PCA antioxidant power. PMID:26180584

  18. Astrocytes Prevent Ethanol Induced Apoptosis of Nrf2 Depleted Neurons by Maintaining GSH Homeostasis.

    PubMed

    Narasimhan, Madhusudhanan; Rathinam, Marylatha; Patel, Dhyanesh; Henderson, George; Mahimainathan, Lenin

    2012-07-01

    Glutathione (GSH), a major cellular antioxidant protects cells against oxidative stress injury. Nuclear factor erythroid 2-related factor 2 (NFE2L2/Nrf2) is a redox sensitive master regulator of battery of antioxidant enzymes including those involved in GSH antioxidant machinery. Earlier we reported that ethanol (ETOH) elicits apoptotic death of primary cortical neurons (PCNs) which in partly due to depletion of intracellular GSH levels. Further a recent report from our laboratory illustrated that ETOH exacerbated the dysregulation of GSH and caspase mediated cell death of cortical neurons that are compromised in Nrf2 machinery (Narasimhan et al., 2011). In various experimental models of neurodegeneration, neuronal antioxidant defenses mainly GSH has been shown to be supported by astrocytes. We therefore sought to determine whether astrocytes can render protection to neurons against ETOH toxicity, particularly when the function of Nrf2 is compromised in neurons. The experimental model consisted of co-culturing primary cortical astrocytes (PCA) with Nrf2 downregulated PCNs that were exposed with 4 mg/mL ETOH for 24 h. Monochlorobimane (MCB) staining followed by FACS analysis showed that astrocytes blocked ETOH induced GSH decrement in Nrf2-silenced neurons as opposed to exaggerated GSH depletion in Nrf2 downregulated PCNs alone. Similarly, the heightened activation of caspase 3/7 observed in Nrf2-compromised neurons was attenuated when co-cultured with astrocytes as measured by luminescence based caspase Glo assay. Furthermore, annexin-V-FITC staining followed by FACS analysis revealed that Nrf2 depleted neurons showed resistance to ETOH induced neuronal apoptosis when co-cultured with astrocytes. Thus, the current study identifies ETOH induced dysregulation of GSH and associated apoptotic events observed in Nrf2-depleted neurons can be blocked by astrocytes. Further our results suggest that this neuroprotective effect of astrocyte despite dysfunctional Nrf2 system

  19. Exogenous cardiolipin localizes to mitochondria and prevents TAZ knockdown-induced apoptosis in myeloid progenitor cells.

    PubMed

    Ikon, Nikita; Su, Betty; Hsu, Fong-Fu; Forte, Trudy M; Ryan, Robert O

    2015-08-21

    The concentration and composition of cardiolipin (CL) in mitochondria are altered in age-related heart disease, Barth Syndrome, and other rare genetic disorders, resulting in mitochondrial dysfunction. To explore whether exogenous CL can be delivered to cells, CL was combined with apolipoprotein A-I to generate water-soluble, nanoscale complexes termed nanodisks (ND). Mass spectrometry of HL60 myeloid progenitor cell extracts revealed a 30-fold increase in cellular CL content following incubation with CL-ND. When CL-ND containing a fluorescent CL analogue was employed, confocal microscopy revealed CL localization to mitochondria. The ability of CL-ND to elicit a physiological response was examined in an HL60 cell culture model of Barth Syndrome neutropenia. siRNA knockdown of the phospholipid transacylase, tafazzin (TAZ), induced apoptosis in these cells. When TAZ knockdown cells were incubated with CL-ND, the apoptotic response was attenuated. Thus, CL-ND represent a potential intervention strategy for replenishment of CL in Barth Syndrome, age-related heart disease, and other disorders characterized by depletion of this key mitochondrial phospholipid.

  20. Exogenous cardiolipin localizes to mitochondria and prevents TAZ knockdown-induced apoptosis in myeloid progenitor cells

    PubMed Central

    Ikon, Nikita; Su, Betty; Hsu, Fong-Fu; Forteand, Trudy M.; Ryan, Robert O.

    2015-01-01

    The concentration and composition of cardiolipin (CL) in mitochondria are altered in age-related heart disease, Barth Syndrome, and other rare genetic disorders, resulting in mitochondrial dysfunction. To explore whether exogenous CL can be delivered to cells, CL was combined with apolipoprotein A-I to generate water-soluble, nanoscale complexes termed nanodisks (ND). Mass spectrometry HL60 myeloid progenitor cell extracts revealed a 30-fold increase in cellular CL content following incubation with CL-ND. When CL-ND containing a fluorescent CL analogue was employed, confocal microscopy revealed CL localization to mitochondria. The ability of CL-ND to elicit a physiological response was examined in an HL60 cell culture model of Barth Syndrome neutropenia. siRNA knockdown of the phospholipid transacylase, tafazzin (TAZ), induced apoptosis in these cells. When TAZ knockdown cells were incubated with CL-ND, the apoptotic response was attenuated. Thus, CL-ND represent a potential intervention strategy for replenishment of CL in Barth Syndrome, age-related heart disease, and other disorders characterized by depletion of this key mitochondrial phospholipid. PMID:26164234

  1. Prevention of glucocorticoid induced-apoptosis of osteoblasts and osteocytes by protecting against endoplasmic reticulum (ER) stress in vitro and in vivo in female mice.

    PubMed

    Sato, Amy Y; Tu, Xiaolin; McAndrews, Kevin A; Plotkin, Lilian I; Bellido, Teresita

    2015-04-01

    Endoplasmic reticulum (ER) stress is associated with increased reactive oxygen species (ROS), results from accumulation of misfolded/unfolded proteins, and can trigger apoptosis. ER stress is alleviated by phosphorylation of eukaryotic translation initiation factor 2α (eIF2α), which inhibits protein translation allowing the ER to recover, thus promoting cell viability. We investigated whether osteoblastic cell apoptosis induced by glucocorticoids (GCs) is due to induction of ROS/ER stress and whether inhibition of eIF2α dephosphorylation promotes survival opposing the deleterious effects of GC in vitro and in vivo. Apoptosis of osteocytic MLO-Y4 and osteoblastic OB-6 cells induced by dexamethasone was abolished by ROS inhibitors. Like GC, the ER stress inducing agents brefeldin A and tunicamycin induced osteoblastic cell apoptosis. Salubrinal or guanabenz, specific inhibitors of eIF2α dephosphorylation, blocked apoptosis induced by either GC or ER stress inducers. Moreover, GC markedly decreased mineralization in OB-6 cells or primary osteoblasts; and salubrinal or guanabenz increased mineralization and prevented the inhibitory effect of GC. Furthermore, salubrinal (1 mg/kg/day) abolished osteoblast and osteocyte apoptosis in cancellous and cortical bone and partially prevented the loss of BMD at all sites and the decreased vertebral cancellous bone formation induced by treatment with prednisolone for 28 days (1.4 mg/kg/day). We conclude that part of the pro-apoptotic actions of GC on osteoblastic cells is mediated through ER stress, and that inhibition of eIF2α dephosphorylation protects from GC-induced apoptosis of osteoblasts and osteocytes in vitro and in vivo and from the deleterious effects of GC on the skeleton. PMID:25532480

  2. Mitochondria-dependent apoptosis of con A-activated T lymphocytes induced by asiatic acid for preventing murine fulminant hepatitis.

    PubMed

    Guo, Wenjie; Liu, Wen; Hong, Shaocheng; Liu, Hailiang; Qian, Cheng; Shen, Yan; Wu, Xuefeng; Sun, Yang; Xu, Qiang

    2012-01-01

    Selectively facilitating apoptosis of activated T cells is essential for the clearance of pathogenic injurious cells and subsequent efficient resolution of inflammation. However, few chemicals have been reported to trigger apoptosis of activated T cells for the treatment of hepatitis without affecting quiescent T cells. In the present study, we found that asiatic acid, a natural triterpenoid, selectively triggered apoptosis of concanavalin A (Con A)-activated T cells in a mitochondria-dependent manner indicated by the disruption of the mitochondrial transmembrane potential, release of cytochrome c from mitochondria to cytosol, caspases activation, and cleavage of PARP. In addition, asiatic acid also induced the cleavage of caspase 8 and Bid and augmented Fas expression in Con A-activated T cells. However, following activation of T cells from MRL(lpr/lpr) mice with mutation of Fas demonstrated a similar susceptibility to asiatic acid-induced apoptosis compared with normal T cells, suggesting that Fas-mediated death-receptor apoptotic pathway does not mainly contribute to asiatic acid-induced cell death. Furthermore, asiatic acid significantly alleviated Con A-induced T cell-dependent fulminant hepatitis in mice, as assessed by reduced serum transaminases, pro-inflammatory cytokines, and pathologic parameters. Consistent with the in vitro results, asiatic acid also induced apoptosis of activated CD4(+) T cells in vivo. Taken together, our results demonstrated that the ability of asiatic acid to induce apoptosis of activated T cells and its potential use in the treatment of T-cell-mediated inflammatory diseases.

  3. Ilex latifolia Prevents Amyloid β Protein (25-35)-Induced Memory Impairment by Inhibiting Apoptosis and Tau Phosphorylation in Mice.

    PubMed

    Kim, Joo Youn; Lee, Hong Kyu; Jang, Ji Yeon; Yoo, Jae Kuk; Seong, Yeon Hee

    2015-12-01

    Ilex latifolia Thunb. (Aquifoliaceae), a Chinese bitter tea called "kudingcha," has been widely consumed as a health beverage and found to possess antioxidant, antidiabetic, antihypertensive, anti-inflammatory, and anti-ischemic activities. The aim of the present study was to investigate the neuroprotective effects of an ethanol extract of I. latifolia against amyloid β protein (Aβ)-induced memory impairment in mice and neurotoxicity in cultured rat cortical neurons. Memory impairment in mice was induced by intracerebroventricular injection of 15 nmol Aβ (25-35) and measured by the passive avoidance test and Morris water maze test. Chronic administration of I. latifolia (25-100 mg/kg, p.o.) significantly prevented Aβ (25-35)-induced memory loss. I. latifolia also prevented the decrease of glutathione concentrations, increased lipid peroxidation, expression of phosphorylated tau (p-tau), and changes in apoptosis-associated proteins in the memory-impaired mouse brain. Exposure of cultured cortical neurons to 10 μM Aβ (25-35) for 36 h induced neuronal apoptotic death. The neuronal cell death, elevation of intracellular Ca(2+) concentration, generation of reactive oxygen species, and expression of proapoptotic proteins caused by Aβ (25-35) in the cultured neurons were inhibited by treatment with I. latifolia (1-50 μg/mL). These results suggest that I. latifolia may have a possible therapeutic role in managing cognitive impairment associated with Alzheimer's disease. The underlying mechanism might involve the antiapoptotic effects mediated by antioxidant activity and inhibition of p-tau formation.

  4. Preventive effects of imperatorin on perfluorohexanesulfonate-induced neuronal apoptosis via inhibition of intracellular calcium-mediated ERK pathway.

    PubMed

    Lee, Eunkyung; Choi, So-Young; Yang, Jae-Ho; Lee, Youn Ju

    2016-07-01

    Early life neuronal exposure to environmental toxicants has been suggested to be an important etiology of neurodegenerative disease development. Perfluorohexanesulfonate (PFHxS), one of the major perfluoroalkyl compounds, is widely distributed environmental contaminants. We have reported that PFHxS induces neuronal apoptosis via ERK-mediated pathway. Imperatorin is a furanocoumarin found in various edible plants and has a wide range of pharmacological effects including neuroprotection. In this study, the effects of imperatorin on PFHxS-induced neuronal apoptosis and the underlying mechanisms are examined using cerebellar granule cells (CGC). CGC were isolated from seven-day old rats and were grown in culture for seven days. Caspase-3 activity and TUNEL staining were used to determine neuronal apoptosis. PFHxS-induced apoptosis of CGC was significantly reduced by imperatorin and PD98059, an ERK pathway inhibitor. PFHxS induced a persistent increase in intracellular calcium, which was significantly blocked by imperatorin, NMDA receptor antagonist, MK801 and the L-type voltage-dependent calcium channel blockers, diltiazem and nifedipine. The activation of caspase-3 by PFHxS was also inhibited by MK801, diltiazem and nifedipine. PFHxS-increased ERK activation was inhibited by imperatorin, MK801, diltiazem and nifedipine. Taken together, imperatorin protects CGC against PFHxS-induced apoptosis via inhibition of NMDA receptor/intracellular calcium-mediated ERK pathway. PMID:27382356

  5. Preventive effects of imperatorin on perfluorohexanesulfonate-induced neuronal apoptosis via inhibition of intracellular calcium-mediated ERK pathway

    PubMed Central

    Lee, Eunkyung; Choi, So-Young; Yang, Jae-Ho

    2016-01-01

    Early life neuronal exposure to environmental toxicants has been suggested to be an important etiology of neurodegenerative disease development. Perfluorohexanesulfonate (PFHxS), one of the major perfluoroalkyl compounds, is widely distributed environmental contaminants. We have reported that PFHxS induces neuronal apoptosis via ERK-mediated pathway. Imperatorin is a furanocoumarin found in various edible plants and has a wide range of pharmacological effects including neuroprotection. In this study, the effects of imperatorin on PFHxS-induced neuronal apoptosis and the underlying mechanisms are examined using cerebellar granule cells (CGC). CGC were isolated from seven-day old rats and were grown in culture for seven days. Caspase-3 activity and TUNEL staining were used to determine neuronal apoptosis. PFHxS-induced apoptosis of CGC was significantly reduced by imperatorin and PD98059, an ERK pathway inhibitor. PFHxS induced a persistent increase in intracellular calcium, which was significantly blocked by imperatorin, NMDA receptor antagonist, MK801 and the L-type voltage-dependent calcium channel blockers, diltiazem and nifedipine. The activation of caspase-3 by PFHxS was also inhibited by MK801, diltiazem and nifedipine. PFHxS-increased ERK activation was inhibited by imperatorin, MK801, diltiazem and nifedipine. Taken together, imperatorin protects CGC against PFHxS-induced apoptosis via inhibition of NMDA receptor/intracellular calcium-mediated ERK pathway. PMID:27382356

  6. Heparin Interaction with the Primed Polymorphonuclear Leukocyte CD11b Induces Apoptosis and Prevents Cell Activation

    PubMed Central

    Cohen-Mazor, Meital; Mazor, Rafi; Kristal, Batya; Kistler, Erik B.; Ziv, Inbal; Chezar, Judith; Sela, Shifra

    2015-01-01

    Heparin is known to have anti-inflammatory effects, yet the mechanisms are not completely understood. In this study, we tested the hypothesis that heparin has a direct effect on activated polymorphonuclear leukocytes (PMNLs), changing their activation state, and can explain its anti-inflammatory effect. To test our hypothesis, we designed both in vitro and ex vivo studies to elucidate the mechanism by which heparin modulates PMNL functions and therefore the inflammatory response. We specifically tested the hypothesis that priming of PMNLs renders them more susceptible to heparin. Amplified levels of CD11b and increased rate of superoxide release manifested PMNL priming. Increase in cell priming resulted in a dose-dependent increase in heparin binding to PMNLs followed by augmented apoptosis. Blocking antibodies to CD11b inhibited heparin binding and abolished the apoptotic response. Moreover, heparin caused a significant dose-dependent decrease in the rate of superoxide release from PMNLs, which was blunted by blocking antibodies to CD11b. Altogether, this study shows that the interaction of heparin with the PMNL CD11b results in cell apoptosis and explains heparin's anti-inflammatory effects. PMID:26819958

  7. TNF-alpha-induced apoptosis is prevented by erythropoietin treatment on SH-SY5Y cells

    SciTech Connect

    Pregi, Nicolas Wenker, Shirley; Vittori, Daniela; Leiros, Claudia Perez; Nesse, Alcira

    2009-02-01

    The growth factor erythropoietin (Epo) has shown neuronal protective action in addition to its well known proerythroid activity. Furthermore, Epo has dealt with cellular inflammation by inhibiting the expression of several proinflammatory cytokines, such as IL-1 and TNF-{alpha}. The action of TNF can have both apoptotic and antiapoptotic consequences due to altered balance between different cell signalling pathways. This work has focused on the apoptotic effects of this cytokine and the potential protective action of Epo. The model we used was neuroblastoma SH-SY5Y cells cultured in the presence of 25 ng/ml TNF-{alpha} or pretreated with 25 U/ml Epo for 12 h before the addition of TNF-{alpha}. Apoptosis was evaluated by differential cell count after Hoechst staining, analysis of DNA ladder pattern, and measurement of caspase activity. Despite its ability to induce NF-{kappa}B nuclear translocation, TNF-{alpha} induced cell death, which was found to be associated to upregulation of TNF Receptor 1 expression. On the other hand, cells activated by Epo became resistant to cell death. Prevention of death receptor upregulation and caspase activation may explain this antiapoptotic effect of Epo, which may be also favoured by the induction of a higher expression of protective factors, such as Bcl-2 and NF-{kappa}B, through mechanisms involving Jak/STAT and PI3K signalling pathways.

  8. A novel polysaccharide from Sargassum integerrimum induces apoptosis in A549 cells and prevents angiogensis in vitro and in vivo

    PubMed Central

    Liu, Ge; Kuang, Shan; Wu, Shimei; Jin, Weihua; Sun, Chaomin

    2016-01-01

    Many polysaccharides isolated from plants have exhibited promising antitumor activities. The aim of this study is to investigate the antitumor activity of the novel polysaccharide named SPS from Sargassum integerrimum, elucidate the underlying anticancer mechanism in a human lung cancer cell line A549, and evaluate its anti-angiogenic activity both in vitro and in vivo. The results show that SPS significantly reduces A549 cells viability in a dose- and time-dependent manner via MTT method. Flow cytometry analysis indicates that SPS could induce cell apoptosis, the loss of mitochondrial membrane potential (MMP), generation of reactive oxygen species (ROS) and G2/M phase cell cycle arrest of A549 cells. Up-regulation of the expressions of P53 and Bax, down-regulation of the expression of Bcl-2, and activation of cleaved caspase-3, caspase-9 and PARP are also detected by western blotting after the treatment of SPS. In addition, SPS inhibits the proliferation, migration and cord formation of human umbilical vein endothelial cells (HUVECs) in vitro, and prevents the vascular development of zebrafish embryos in vivo. Altogether, our data prove the anticancer and anti-angiogenesis properties of SPS, and provide further insights into the potential pharmacological application of SPS as antitumor and anti-angiogenic agent against lung cancer. PMID:27216943

  9. A novel polysaccharide from Sargassum integerrimum induces apoptosis in A549 cells and prevents angiogensis in vitro and in vivo.

    PubMed

    Liu, Ge; Kuang, Shan; Wu, Shimei; Jin, Weihua; Sun, Chaomin

    2016-01-01

    Many polysaccharides isolated from plants have exhibited promising antitumor activities. The aim of this study is to investigate the antitumor activity of the novel polysaccharide named SPS from Sargassum integerrimum, elucidate the underlying anticancer mechanism in a human lung cancer cell line A549, and evaluate its anti-angiogenic activity both in vitro and in vivo. The results show that SPS significantly reduces A549 cells viability in a dose- and time-dependent manner via MTT method. Flow cytometry analysis indicates that SPS could induce cell apoptosis, the loss of mitochondrial membrane potential (MMP), generation of reactive oxygen species (ROS) and G2/M phase cell cycle arrest of A549 cells. Up-regulation of the expressions of P53 and Bax, down-regulation of the expression of Bcl-2, and activation of cleaved caspase-3, caspase-9 and PARP are also detected by western blotting after the treatment of SPS. In addition, SPS inhibits the proliferation, migration and cord formation of human umbilical vein endothelial cells (HUVECs) in vitro, and prevents the vascular development of zebrafish embryos in vivo. Altogether, our data prove the anticancer and anti-angiogenesis properties of SPS, and provide further insights into the potential pharmacological application of SPS as antitumor and anti-angiogenic agent against lung cancer. PMID:27216943

  10. Quercetin Improves Postischemic Recovery of Heart Function in Doxorubicin-Treated Rats and Prevents Doxorubicin-Induced Matrix Metalloproteinase-2 Activation and Apoptosis Induction

    PubMed Central

    Barteková, Monika; Šimončíková, Petra; Fogarassyová, Mária; Ivanová, Monika; Okruhlicová, Ľudmila; Tribulová, Narcisa; Dovinová, Ima; Barančík, Miroslav

    2015-01-01

    Quercetin (QCT) is flavonoid that possesses various biological functions including anti-oxidative and radical-scavenging activities. Moreover, QCT exerts some preventive actions in treatment of cardiovascular diseases. The aim of present study was to explore effects of prolonged administration of QCT on changes induced by repeated application of doxorubicin (DOX) in rat hearts. We focused on the ultrastructure of myocardium, matrix metalloproteinases (MMPs), biometric parameters, and apoptosis induction. Our aim was also to examine effects of QCT on ischemic tolerance in hearts exposed to chronic effects of DOX, and to determine possible mechanisms underlying effects of QCT. Our results showed that QCT prevented several negative chronic effects of DOX: (I) reversed DOX-induced blood pressure increase; (II) mediated improvement of deleterious effects of DOX on ultrastructure of left ventricle; (III) prevented DOX-induced effects on tissue MMP-2 activation; and (iv) reversed effects of DOX on apoptosis induction and superoxide dismutase inhibition. Moreover, we showed that rat hearts exposed to effects of QCT were more resistant to ischemia/reperfusion injury. Effects of QCT on modulation of ischemic tolerance were linked to Akt kinase activation and connexin-43 up-regulation. Taken together, these results demonstrate that prolonged treatment with QCT prevented negative chronic effects of DOX on blood pressure, cellular damage, MMP-2 activation, and apoptosis induction. Moreover, QCT influenced myocardial responses to acute ischemic stress. These facts bring new insights into mechanisms of QCT action on rat hearts exposed to the chronic effects of DOX. PMID:25872140

  11. Isoliquiritigenin isolated from licorice Glycyrrhiza uralensis prevents 6-hydroxydopamine-induced apoptosis in dopaminergic neurons.

    PubMed

    Hwang, Cheol Kyu; Chun, Hong Sung

    2012-01-01

    Licorice (Glycyrrhiza uralensis) is a medicinal herb containing various bioactive components implicated in antioxidative, anti-inflammatory, antiviral, and neuroprotective effects, but the effects of licorice against Parkinson's disease (PD)-related dopaminergic cell death have not been studied. In this study, we investigated the protective effects of isoliquiritigenin (ISL) isolated from Glycyrrhiza uralensis on 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in a dopaminergic cell line, SN4741. ISL (1 µM) significantly attenuated 6-OHDA (50 µM)-induced reactive oxygen species (ROS) and nitric oxide (NO) generation and apoptotic cell death. ISL pretreatment effectively suppressed 6-OHDA-mediated upregulation of Bax, p-c-Jun N-terminal kinase (JNK), p-p38 mitogen-activated protein (MAP) kinase, cytochrome c release, and caspase 3 activation. In addition, ISL significantly attenuated 6-OHDA-induced Bcl-2, brain-derived neurotrophic factor (BDNF), and mitochondrial membrane potential (MMP) reduction. Pharmacological inhibitors of the phosphatidylinositol 3-kinase (PI3K)-Akt/protein kinase B (PKB) pathway reversed ISL-mediated neuroprotection against 6-OHDA toxicity in SN4741 cells. These results provide the first evidence that ISL can protect dopaminergic cells under oxidative stress conditions by regulating the apoptotic process.

  12. Protective effect of RIP and c-FLIP in preventing liver cancer cell apoptosis induced by TRAIL.

    PubMed

    Sun, Jichun; Luo, Hongwu; Nie, Wanpin; Xu, Xundi; Miao, Xiongying; Huang, Feizhou; Wu, Haiyan; Jin, Xiaoxin

    2015-01-01

    TRAIL (TNF-related apoptosis-inducing ligand) is a member of the tumor necrosis factor superfamily that can induce tumor selective death by up-regulating death receptor 4 (DR4) and DR5 expression. The study aimed to explore the role of RIP and c-FLIP genes in TRAIL induced liver cancer cell HepG2 and Hep3B apoptosis and related mechanism. RIP and c-FLIP silenced HepG2 and Hep3B cell model were established through siRNA. Western blot was applied to test c-FLIP, RIP, DR4, DR5, FADD, Caspase-3/8/9, ERK1/2, and DFF45 protein expression. Caspase-8 kit was used to detect Caspase-8 expression. Flow cytometry was performed to measure cell apoptosis rate. Acid phosphatase method was applied to determine cell cycle. TRAIL had no significant effect on Caspase-3/8/9, DR4, DR5, ERK1/2, and DFF45 protein expression, but up-regulated c-FLIP and RIP protein expression and reduced FADD expression level. After treated by the chemotherapy drug mitomycin and adriamycin, c-FLIP and RIP expression decreased significantly, while FADD increased. After knockout c-FLIP and RIP gene, HepG2 and Hep3B cell apoptosis rate induced by TRAIL increased obviously. Meanwhile, cell subG1 percentage increased markedly and exhibited G1 phase growth retardation. In addition, after two kinds of gene knockout, Caspase-8 was activated and produce Caspase-3 P20 and P24, leading DFF45 appeared DNA fragment P17 and P25. c-FLIP and RIP can inhibit Caspase-8 activation and prompting HepG2 and Hep3B resistant to cell apoptosis induced by TRAIL.

  13. Bezafibrate prevents palmitate-induced apoptosis in osteoblastic MC3T3-E1 cells through the NF-κB signaling pathway.

    PubMed

    Zhong, Xing; Xiu, Lingling; Wei, Guohong; Pan, Tianrong; Liu, Yuanyuan; Su, Lei; Li, Yanbing; Xiao, Haipeng

    2011-10-01

    Osteoporosis is a bone condition defined by low bone mass and increase of fracture risk due to imbalance between bone resorption by osteoclasts and bone formation by osteoblasts. Low bone mass is likely to be due to the alteration of the osteoclast and osteoblast lifespan through regulated apoptosis. Saturated fatty acid (SFA) intake is negatively associated with bone mineral density (BMD). Furthermore, SFA induces apoptosis in osteoblastic cell lines. Bezafibrate could increase bone mass in intact male rats principally through increasing periosteal bone formation. At present, it is unknown whether bezafibrate attenuates palmitate-induced apoptosis in MC3T3-E1 cells. In the present study, we found that palmitate stimulated the degradation of IκBα and NF-κB translocation, as well as up-regulation of NF-κB-mediated Fas expression in obsteoblastic MC3T3-E1 cells. Furthermore, the NF-κB inhibitor pyrrolidine dithiocarbamate (PDTC) could restore palmitate-induced caspase-3 decrease and inhibit palmitate-induced cleaved caspase-3 increase. We observed that bezafibrate, a dual ligand for the peroxisome proliferator-activated receptors α (PPARα) and PPARδ, significantly attenuated the palmitate-induced cytotoxicity as determined by the MTT assay and inhibited the palmitate-induced apoptosis as determined by a flow cytometry assay using Annexin V-FITC/PI and assessment of the activity of caspase-3. Pre-treatment of bezafibrate prevented palmitate-induced NF-κB activation. Therefore, these findings indicate that bezafibrate inbibits palmitate-induced apoptosis via the NF-κB signaling pathway. Our results point to bezafibrate as a new strategy to attenuate bone loss associated with high fat diet beyond its lipid-lowering actions. PMID:21687928

  14. δ-Tocopherol prevents methylglyoxal-induced apoptosis by reducing ROS generation and inhibiting apoptotic signaling cascades in human umbilical vein endothelial cells.

    PubMed

    Do, Moon ho; Kim, Su nam; Seo, Seung-Yong; Yeo, Eui-Ju; Kim, Sun Yeou

    2015-05-01

    Methylglyoxal (MGO) is a highly reactive metabolite of glucose, which is known to cause damage and induce apoptosis in endothelial cells. Endothelial cell damage is implicated in the progression of diabetes-associated complications and atherosclerosis. Nuts are high in vitamin E. Consumption of nuts has been recommended for the prevention of cardiovascular disease. However, different nuts contain different forms of vitamin E, which can have different effects on endothelial cells. In this work, we investigated the protective effect of different isoforms of vitamin E on MGO-induced apoptosis in human umbilical vein endothelial cells (HUVECs). Among all forms of vitamin E, δ-tocopherol showed the highest effect on apoptosis of HUVECs. We also compared the anti-apoptotic activity of δ-tocopherol with that of α-tocopherol in MGO-treated HUVECs. Pretreatment with α- or δ-tocopherol significantly inhibited MGO-induced changes in cell morphology, cell death, and production of intracellular reactive oxygen species. δ-Tocopherol prevented MGO-induced apoptosis in HUVECs by increasing Bcl-2 expression and decreasing Bax expression. Interestingly, α-tocopherol also inhibited these factors but to a lesser extent than δ-tocopherol. MGO was found to activate mitogen-activated protein kinases (MAPKs). Compared to pretreatment with α-tocopherol, pretreatment with δ-tocopherol more strongly inhibited the activation of MAPKs, such as JNK and ERK1/2. These findings suggest that δ-tocopherol may be a more effective regulator of MGO-induced apoptosis than α-tocopherol.

  15. Goniothalamin prevents the development of chemically induced and spontaneous colitis in rodents and induces apoptosis in the HT-29 human colon tumor cell line.

    PubMed

    Vendramini-Costa, Débora Barbosa; Alcaide, Antonio; Pelizzaro-Rocha, Karin Juliane; Talero, Elena; Ávila-Román, Javier; Garcia-Mauriño, Sofia; Pilli, Ronaldo Aloise; de Carvalho, João Ernesto; Motilva, Virginia

    2016-06-01

    Colon cancer is the third most incident type of cancer worldwide. One of the most important risk factors for colon cancer development are inflammatory bowel diseases (IBD), thus therapies focusing on IBD treatment have great potential to be used in cancer prevention. Nature has been a source of new therapeutic and preventive agents and the racemic form of the styryl-lactone goniothalamin (GTN) has been shown to be a promising antiproliferative agent, with gastroprotective, antinociceptive and anti-inflammatory effects. As inflammation is a well-known tumor promoter, the major goal of this study was to evaluate the therapeutic and preventive potentials of GTN on chemically induced and spontaneous colitis, as well as the cytotoxic effects of GTN on a human colon tumor cell line (HT-29). GTN treatments inhibited TNBS-induced acute and chronic colitis development in Wistar rats, reducing myeloperoxidase levels and inflammatory cells infiltration in the mucosa. In spontaneous-colitis using IL-10 deficient mice (C57BL/6 background), GTN prevented colitis development through downregulation of TNF-α, upregulation of SIRT-1 and inhibition of proliferation (PCNA index), without signs of toxicity after three months of treatment. In HT-29 cells, treatment with 10μM of GTN induced apoptosis by increasing BAX/BCL2, p-JNK1/JNK1, p-P38/P38 ratios as well as through ROS generation. Caspase 8, 9 and 3 activation also occurred, suggesting caspase-dependent apoptotic pathway, culminating in PARP-1 cleavage. Together with previous data, these results show the importance of GTN as a pro-apoptotic, preventive and therapeutic agent for IBD and highlight its potential as a chemopreventive agent for colon cancer.

  16. The metabolites of glutamine prevent hydroxyl radical-induced apoptosis through inhibiting mitochondria and calcium ion involved pathways in fish erythrocytes.

    PubMed

    Li, Huatao; Jiang, Weidan; Liu, Yang; Jiang, Jun; Zhang, Yongan; Wu, Pei; Zhao, Juan; Duan, Xudong; Zhou, Xiaoqiu; Feng, Lin

    2016-03-01

    The present study explored the apoptosis pathways in hydroxyl radicals ((∙)OH)-induced carp erythrocytes. Carp erythrocytes were treated with the caspase inhibitors in physiological carp saline (PCS) or Ca(2+)-free PCS in the presence of 40μM FeSO4/20μM H2O2. The results showed that the generation of reactive oxygen species (ROS), the release of cytochrome c and DNA fragmentation were caspase-dependent, and Ca(2+) was involved in calpain activation and phosphatidylserine (PS) exposure in (∙)OH-induced carp erythrocytes. Moreover, the results suggested that caspases were involved in PS exposure, and Ca(2+) was involved in DNA fragmentation in (∙)OH-induced fish erythrocytes. These results demonstrated that there might be two apoptosis pathways in fish erythrocytes, one is the caspase and cytochrome c-dependent apoptosis that is similar to that in mammal nucleated cells, the other is the Ca(2+)-involved apoptosis that was similar to that in mammal non-nucleated erythrocytes. So, fish erythrocytes may be used as a model for studying oxidative stress and apoptosis in mammal cells. Furthermore, the present study investigated the effects of glutamine (Gln)'s metabolites [alanine (Ala), citrulline (Cit), proline (Pro) and their combination (Ala10Pro4Cit1)] on the pathways of apoptosis in fish erythrocytes. The results displayed that Ala, Cit, Pro and Ala10Pro4Cit1 effectively suppressed ROS generation, cytochrome c release, activation of caspase-3, caspase-8 and caspase-9 at the physiological concentrations, prevented Ca(2+) influx, calpain activation, PS exposure, DNA fragmentation and the degradation of the cytoskeleton and oxidation of membrane and hemoglobin (Hb) and increased activity of anti-hydroxyl radical (AHR) in (∙)OH-induced carp erythrocytes. Ala10Pro4Cit1 produced a synergistic effect of inhibited oxidative stress and apoptosis in fish erythrocytes. These results demonstrated that Ala, Cit, Pro and their combination can protect mammal erythrocytes

  17. Tetrachloro-p-benzoquinone induces hepatic oxidative damage and inflammatory response, but not apoptosis in mouse: The prevention of curcumin

    SciTech Connect

    Xu, Demei; Hu, Lihua; Su, Chuanyang; Xia, Xiaomin; Zhang, Pu; Fu, Juanli; Wang, Wenchao; Xu, Duo; Du, Hong; Hu, Qiuling; Song, Erqun; Song, Yang

    2014-10-15

    This study investigated the protective effects of curcumin on tetrachloro-p-benzoquinone (TCBQ)-induced hepatotoxicity in mice. TCBQ-treatment causes significant liver injury (the elevation of serum AST and ALT activities, histopathological changes in liver section including centrilobular necrosis and inflammatory cells), oxidative stress (the elevation of TBAR level and the inhibition of SOD and catalase activities) and inflammation (up-regulation of iNOS, COX-2, IL-1β, IL-6, TNF-α and NF-κB). However, these changes were alleviated upon pretreatment with curcumin. Interestingly, TCBQ has no effect on caspase family genes or B-cell lymphoma 2 (Bcl-2)/Bcl-2 associated X (Bax) protein expressions, which implied that TCBQ-induced hepatotoxicity is independent of apoptosis. Moreover, curcumin was shown to induce phase II detoxifying/antioxidant enzymes HO-1 and NQO1 through the activation of nuclear factor erythroid-derived 2-like 2 (Nrf2). In summary, the protective mechanisms of curcumin against TCBQ-induced hepatoxicity may be related to the attenuation of oxidative stress, along with the inhibition of inflammatory response via the activation of Nrf2 signaling. - Highlights: • TCBQ-intoxication significantly increased AST and ALT activities. • TCBQ-intoxication induced oxidative stress in mice liver. • TCBQ-intoxication induced inflammatory response in mice liver. • TCBQ-intoxication induced hepatotoxicity is independent of apoptosis. • Curcumin relieved TCBQ-induced liver damage remarkably.

  18. Neuroglobin upregulation induced by 17β-estradiol sequesters cytocrome c in the mitochondria preventing H2O2-induced apoptosis of neuroblastoma cells

    PubMed Central

    De Marinis, E; Fiocchetti, M; Acconcia, F; Ascenzi, P; Marino, M

    2013-01-01

    The sex steroid hormone 17β-estradiol (E2) upregulates the levels of neuroglobin (NGB), a new neuroprotectant globin, to elicit its neuroprotective effect against H2O2-induced apoptosis. Several mechanisms could be proposed to justify the NGB involvement in E2 prevention of stress-induced apoptotic cell death. Here, we evaluate the ability of E2 to modulate the intracellular NGB localization and the NGB interaction with mitochondrial cytochrome c following the H2O2-induced toxicity. Present results demonstrate that NGB is expressed in the nuclei, mitochondria, and cytosol of human neuroblastoma SK-N-BE cells. E2, but not H2O2 treatment of SK-N-BE cells, reallocates NGB mainly at the mitochondria and contemporarily reduces the number of apoptotic nuclei and the levels of cleaved caspase-3. Remarkably, the E2 treatment strongly increases NGB–cytochrome c association into mitochondria and reduces the levels of cytochrome c into the cytosol of SK-N-BE cells. Although both estrogen receptors (ERα and ERβ) are expressed in the nucleus, mitochondria, and cytosol of SK-N-BE cells, this E2 effect specifically requires the mitochondrial ERβ activity. As a whole, these data demonstrate that the interception of the intrinsic apoptotic pathway into mitochondria (i.e., the prevention of cytochrome c release) is one of the pivotal mechanisms underlying E2-dependent NGB neuroprotection against H2O2 toxicity. PMID:23429294

  19. Targeting Apoptosis Signalling Kinase-1 (ASK-1) Does Not Prevent the Development of Neuropathy in Streptozotocin-Induced Diabetic Mice

    PubMed Central

    Newton, Victoria L.; Ali, Sumia; Duddy, Graham; Whitmarsh, Alan J.; Gardiner, Natalie J.

    2014-01-01

    Apoptosis signal-regulating kinase-1 (ASK1) is a mitogen-activated protein 3 kinase (MAPKKK/MAP3K) which lies upstream of the stress-activated MAPKs, JNK and p38. ASK1 may be activated by a variety of extracellular and intracellular stimuli. MAP kinase activation in the sensory nervous system as a result of diabetes has been shown in numerous preclinical and clinical studies. As a common upstream activator of both p38 and JNK, we hypothesised that activation of ASK1 contributes to nerve dysfunction in diabetic neuropathy. We therefore wanted to characterize the expression of ASK1 in sensory neurons, and determine whether the absence of functional ASK1 would protect against the development of neuropathy in a mouse model of experimental diabetes. ASK1 mRNA and protein is constitutively expressed by multiple populations of sensory neurons of the adult mouse lumbar DRG. Diabetes was induced in male C57BL/6 and transgenic ASK1 kinase-inactive (ASK1n) mice using streptozotocin. Levels of ASK1 do not change in the DRG, spinal cord, or sciatic nerve following induction of diabetes. However, levels of ASK2 mRNA increase in the spinal cord at 4 weeks of diabetes, which could represent a future target for this field. Neither motor nerve conduction velocity deficits, nor thermal or mechanical hypoalgesia were prevented or ameliorated in diabetic ASK1n mice. These results suggest that activation of ASK1 is not responsible for the nerve deficits observed in this mouse model of diabetic neuropathy. PMID:25329046

  20. The Salmonella effector SopB prevents ROS-induced apoptosis of epithelial cells by retarding TRAF6 recruitment to mitochondria.

    PubMed

    Ruan, Haihua; Zhang, Zhen; Tian, Li; Wang, Suying; Hu, Shuangyan; Qiao, Jian-Jun

    2016-09-16

    Microbial pathogens enter host cells by injecting effector proteins of the Type III secretion system (T3SS), which facilitate pathogen translocation across the host cell membrane. These effector proteins exert their effects by modulating a variety of host innate immune responses, thereby facilitating bacterial replication and systemic infection. Salmonella enterica serovar typhimurium (S.typhimurium) is a clinically important pathogen that causes food poisoning and gastroenteritis. The SopB effector protein of S. typhimurium, encoded by Salmonella pathogenicity islands (SPI)-1 T3SS, protects host epithelial cells from infection-induced apoptosis. However, how SopB influences apoptosis induction remains unclear. Here, we investigated the mechanism of SopB action in host cells. We found that SopB inhibits infection-induced apoptosis by attenuating the production of reactive oxygen species (ROS) in mitochondria, the crucial organelles for apoptosis initiation. Further investigation revealed that SopB binds to cytosolic tumor necrosis factor receptor associated factor 6 (TRAF6) and forms a trap preventing the mitochondrial recruitment of TRAF6, an essential event for ROS generation within mitochondria. By studying the response of Traf6(+/+) and Traf6(-/-)mouse embryonic fibroblasts to S. typhimurium infection, we found that TRAF6 promoted apoptosis by increasing ROS accumulation, which led to increased Bax/Bcl-2 ratio, Bax recruitment to mitochondrial membrane, and release of Cyt c into the cytoplasm. These findings show that SopB suppresses host cell apoptosis by binding to TRAF6 and preventing mitochondrial ROS generation. PMID:27473656

  1. Metformin prevents endoplasmic reticulum stress-induced apoptosis through AMPK-PI3K-c-Jun NH2 pathway

    USGS Publications Warehouse

    Jung, T.W.; Lee, M.W.; Lee, Y.-J.; Kim, S.M.

    2012-01-01

    Type 2 diabetes mellitus is thought to be partially associated with endoplasmic reticulum (ER) stress toxicity on pancreatic beta cells and the result of decreased insulin synthesis and secretion. In this study, we showed that a well-known insulin sensitizer, metformin, directly protects against dysfunction and death of ER stress-induced NIT-1 cells (a mouse pancreatic beta cell line) via AMP-activated protein kinase (AMPK) and phosphatidylinositol-3 (PI3) kinase activation. We also showed that exposure of NIT-1 cells to metformin (5mM) increases cellular resistance against ER stress-induced NIT-1 cell dysfunction and death. AMPK and PI3 kinase inhibitors abolished the effect of metformin on cell function and death. Metformin-mediated protective effects on ER stress-induced apoptosis were not a result of an unfolded protein response or the induced inhibitors of apoptotic proteins. In addition, we showed that exposure of ER stressed-induced NIT-1 cells to metformin decreases the phosphorylation of c-Jun NH(2) terminal kinase (JNK). These data suggest that metformin is an important determinant of ER stress-induced apoptosis in NIT-1 cells and may have implications for ER stress-mediated pancreatic beta cell destruction via regulation of the AMPK-PI3 kinase-JNK pathway.

  2. Treadmill exercise prevents aging-induced failure of memory through an increase in neurogenesis and suppression of apoptosis in rat hippocampus.

    PubMed

    Kim, Sung-Eun; Ko, Il-Gyu; Kim, Bo-Kyun; Shin, Mal-Soon; Cho, Sehyung; Kim, Chang-Ju; Kim, Sang-Hun; Baek, Seung-Soo; Lee, Eun-Kyu; Jee, Yong-Seok

    2010-05-01

    Aging leads to functional changes in the hippocampus, and consequently induces cognitive deficits, such as failure of memory. Neurogenesis in the hippocampal dentate gyrus continues throughout life, but steadily declines from early adulthood. Apoptosis occurs under various pathologic and physiologic conditions, and excessive apoptotic cell death can cause a number of functional disorders in humans. Apoptosis in the hippocampus also disturbs cognitive functions. In this study, we examined the effect of treadmill exercise on memory in relation to neurogensis and apoptosis in the hippocampal dentate gyrus of old-aged rats. The present results showed that loss of memory by aging was associated with a decrease in neurogenesis and an increase in apoptosis in the hippocampal dentate gyrus. Treadmill exercise improved short-term and spatial memories by enhancing neurogenesis and suppressing apoptosis in the hippocampal dentate gyrus of old-aged rats. In the present study, we showed that treadmill exercise is a very useful strategy for preventing failure of memory in the elderly.

  3. Preservation of Cellular Glutathione Status and Mitochondrial Membrane Potential by N-Acetylcysteine and Insulin Sensitizers Prevent Carbonyl Stress-Induced Human Brain Endothelial Cell Apoptosis

    PubMed Central

    Okouchi, Masahiro; Okayama, Naotsuka; Aw, Tak Yee

    2011-01-01

    Oxidative stress-induced cerebral endothelial cell dysfunction is associated with cerebral microvascular complication of primary diabetic encephaolopathy, a neurodegenerative disorder of long-standing diabetes, but the injury mechanisms are poorly understood. This study sought to determine the contribution of carbonyl (methylglyoxal, MG) stress to human brain endothelial cell (IHEC) apoptosis, the relationship to cellular redox status and mitochondrial membrane potential, and the protection by thiol antioxidant and insulin sensitizers. MG exposure induced IHEC apoptosis in association with perturbed cellular glutathione (GSH) redox status, decreased mitochondrial membrane potential (Δψm), activation of caspase-9 and -3, and cleavage of polyADP-ribose polymerase. Insulin sensitizers such as biguanides or AMP-activated protein kinase activator, but not glitazones, afforded cytoprotection through preventing Δψm collapse and activation of caspase-9 that was independent of cellular GSH. Similarly, cyclosporine A prevented Δψm collapse, while N-acetylcysteine (NAC) mediated the recovery of cellular GSH redox balance that secondarily preserved Δψm. Collectively, these results provide mechanistic insights into the role of GSH redox status and mitochondrial potential in carbonyl stress-induced apoptosis of brain endothelial cells, with implications for cerebral microvascular complications associated with primary diabetic encephalopathy. The findings that thiol antioxidant and insulin sensitizers afforded cytoprotection suggest potential therapeutic approaches. PMID:19807652

  4. Baicalein, an active component of Scutellaria baicalensis Georgi, prevents lysophosphatidylcholine-induced cardiac injury by reducing reactive oxygen species production, calcium overload and apoptosis via MAPK pathways

    PubMed Central

    2014-01-01

    Background Lysophosphatidylcholine (lysoPC), a metabolite from membrane phospholipids, accumulates in the ischemic myocardium and plays an important role in the development of myocardial dysfunction ventricular arrhythmia. In this study, we investigated if baicalein, a major component of Huang Qui, can protect against lysoPC-induced cytotoxicity in rat H9c2 embryonic cardiomyocytes. Methods Cell viability was detected by the MTT assay; ROS levels were assessed using DCFH-DA; and intracellular free calcium concentrations were assayed by spectrofluorophotometer. Cell apoptosis and necrosis were evaluated by the flow cytometry assay and Hoechst staining. Mitogen-Activated Protein Kinases (MAPKs), which included the ERK, JNK, and p38, and the apoptotic mechanisms including Bcl-2/Bax, caspase-3, caspase-9 and cytochrome c pathways were examined by Western blot analysis. The activation of MAPKs was examined by enzyme-linked immunosorbent assay. Results We found that lysoPC induced death and apoptosis of H9c2 cells in a dose-dependent manner. Baicalein could prevent lysoPC-induced cell death, production of reactive oxygen species (ROS), and increase of intracellular calcium concentration in H9c2 cardiomyoctes. In addition, baicalein also inhibited lysoPC-induced apoptosis, with associated decreased pro-apoptotic Bax protein, increased anti-apoptotic Bcl-2 protein, resulting in an increase in the Bcl-2/Bax ratio. Finally, baicalein attenuated lysoPC-induced the expression of cytochrome c, casapase-3, casapase-9, and the phosphorylations of ERK1/2, JNK, and p38. LysoPC-induced ERK1/2, JNK, and p38 activations were inhibited by baicalein. Conclusions Baicalein protects cardiomyocytes from lysoPC-induced apoptosis by reducing ROS production, inhibition of calcium overload, and deactivations of MAPK signaling pathways. PMID:25012390

  5. Anti-osteopontin monoclonal antibody prevents ovariectomy-induced osteoporosis in mice by promotion of osteoclast apoptosis

    SciTech Connect

    Zhang, Bo; Dai, Jianxin; Wang, Huaqing; Wei, Huafeng; Zhao, Jian; Guo, Yajun; and others

    2014-09-26

    Highlight: • We first report that anti-osteopontin mAb could protect osteoporosis in mice. • Anti-osteopontin mAb could promote the osteoclast apoptosis. • Targeting osteopontin might have therapeutic potentials for osteoporosis. - Abstract: Osteopontin (OPN) is abundant in mineralized tissues and has long been implicated in bone remodeling. However, the therapeutic effect of targeting OPN in bone loss diseases and the underlying molecular mechanism remain largely unknown. Here, we reported that anti-OPN mAb (23C3) could protect against ovariectomy-induced osteoporosis in mice, demonstrated by microcomputed tomography analysis and histopathology evaluation. In vitro assay showed that 23C3 mAb reduced osteoclasts (OCs)-mediated bone resorption through promotion of mature OC apoptosis. Thus, the study has important implications for understanding the role of OPN in OC bone resorption and survival, and OPN antagonists may have therapeutic potential for osteoporosis and other osteopenic diseases.

  6. Glutamine supplementation prevents exercise-induced neutrophil apoptosis and reduces p38 MAPK and JNK phosphorylation and p53 and caspase 3 expression.

    PubMed

    Lagranha, Claudia J; Hirabara, Sandro M; Curi, Rui; Pithon-Curi, Tania C

    2007-01-01

    We have previously shown that a single session of exercise induces DNA fragmentation, mitochondrial membrane depolarization, increases expression of pro-apoptotic genes (bax and bcl-xS) and decreases expression of anti-apoptotic genes (bcl-xL) in rat neutrophils. Glutamine supplementation had a protective effect in the apoptosis induced by a single session of exercise. The mechanism involved in the effect of single session of exercise to induce apoptosis was investigated by measuring expression of p53 and caspase 3 and phosphorylation of p38 mitogen-activated protein kinases (MAPK) and cJun NH(2)-terminal kinase (JNK) in neutrophils from rats supplemented or not with glutamine. Exercise was carried out on a treadmill for 1 h and the rats were killed by decapitation. Neutrophils were obtained by intraperitoneal (i.p.) lavage with PBS, 4 h after injection of oyster glycogen solution. Glutamine supplementation (1g per Kg b.w.) was given by gavage 1 h before the exercise session. Gene expression and protein phosphorylation were then analyzed by reverse transcriptase chain reaction (RT-PCR) and Western blotting, respectively. A single session of exercise increased p38 MAPK and JNK phosphorylation and p53 and caspase 3 expression. Glutamine supplementation partially prevented the increase in p38 MAPK and JNK phosphorylation and p53 expression, and fully abolished the increase in caspase 3 expression. Thus, neutrophil apoptosis induced by a single session of exercise is accompanied by increased p53 and caspase 3 expression and p38 MAPK and JNK phosphorylation. Glutamine supplementation prevents these effects of exercise and reduces apoptosis. PMID:17542038

  7. Glutamine supplementation prevents exercise-induced neutrophil apoptosis and reduces p38 MAPK and JNK phosphorylation and p53 and caspase 3 expression.

    PubMed

    Lagranha, Claudia J; Hirabara, Sandro M; Curi, Rui; Pithon-Curi, Tania C

    2007-01-01

    We have previously shown that a single session of exercise induces DNA fragmentation, mitochondrial membrane depolarization, increases expression of pro-apoptotic genes (bax and bcl-xS) and decreases expression of anti-apoptotic genes (bcl-xL) in rat neutrophils. Glutamine supplementation had a protective effect in the apoptosis induced by a single session of exercise. The mechanism involved in the effect of single session of exercise to induce apoptosis was investigated by measuring expression of p53 and caspase 3 and phosphorylation of p38 mitogen-activated protein kinases (MAPK) and cJun NH(2)-terminal kinase (JNK) in neutrophils from rats supplemented or not with glutamine. Exercise was carried out on a treadmill for 1 h and the rats were killed by decapitation. Neutrophils were obtained by intraperitoneal (i.p.) lavage with PBS, 4 h after injection of oyster glycogen solution. Glutamine supplementation (1g per Kg b.w.) was given by gavage 1 h before the exercise session. Gene expression and protein phosphorylation were then analyzed by reverse transcriptase chain reaction (RT-PCR) and Western blotting, respectively. A single session of exercise increased p38 MAPK and JNK phosphorylation and p53 and caspase 3 expression. Glutamine supplementation partially prevented the increase in p38 MAPK and JNK phosphorylation and p53 expression, and fully abolished the increase in caspase 3 expression. Thus, neutrophil apoptosis induced by a single session of exercise is accompanied by increased p53 and caspase 3 expression and p38 MAPK and JNK phosphorylation. Glutamine supplementation prevents these effects of exercise and reduces apoptosis.

  8. ERK-mediated activation of Fas apoptotic inhibitory molecule 2 (Faim2) prevents apoptosis of 661W cells in a model of detachment-induced photoreceptor cell death.

    PubMed

    Besirli, Cagri G; Zheng, Qiong-Duon; Reed, David M; Zacks, David N

    2012-01-01

    In this study, we examined the role of Fas apoptotic inhibitory molecule 2 (Faim2), an inhibitor of the Fas signaling pathway, and its regulation by stress kinase signaling during Fas-mediated apoptosis of 661W cells, an immortalized photoreceptor-like cell line Treatment of 661W cells with a Fas-activating antibody led to increased levels of Faim2. Both ERK and JNK stress kinase pathways were activated in Fas-treated 661W cells, but only the inhibition of the ERK pathway reduced the levels of Faim2. Blocking the ERK pathway using a pharmacological inhibitor increased the susceptibility of 661W cells to Fas-induced caspase activation and apoptosis. When the levels of Faim2 were reduced in 661W cells by siRNA knockdown, Fas activating antibody treatment resulted in earlier and more robust caspase activation, and increased cell death. These results demonstrate that Faim2 acts as a neuroprotectant during Fas-mediated apoptosis of 661W cells. The expression of Faim2 is triggered, at least in part, by Fas-receptor activation and subsequent ERK signaling. Our findings identify a novel protective pathway that auto-regulates Fas-induced photoreceptor apoptosis in vitro. Modulation of this pathway to increase Faim2 expression may be a potential therapeutic option to prevent photoreceptor death.

  9. ERK-Mediated Activation of Fas Apoptotic Inhibitory Molecule 2 (Faim2) Prevents Apoptosis of 661W Cells in a Model of Detachment-Induced Photoreceptor Cell Death

    PubMed Central

    Besirli, Cagri G.; Zheng, Qiong-Duon; Reed, David M.; Zacks, David N.

    2012-01-01

    In this study, we examined the role of Fas apoptotic inhibitory molecule 2 (Faim2), an inhibitor of the Fas signaling pathway, and its regulation by stress kinase signaling during Fas-mediated apoptosis of 661W cells, an immortalized photoreceptor-like cell line Treatment of 661W cells with a Fas-activating antibody led to increased levels of Faim2. Both ERK and JNK stress kinase pathways were activated in Fas-treated 661W cells, but only the inhibition of the ERK pathway reduced the levels of Faim2. Blocking the ERK pathway using a pharmacological inhibitor increased the susceptibility of 661W cells to Fas-induced caspase activation and apoptosis. When the levels of Faim2 were reduced in 661W cells by siRNA knockdown, Fas activating antibody treatment resulted in earlier and more robust caspase activation, and increased cell death. These results demonstrate that Faim2 acts as a neuroprotectant during Fas-mediated apoptosis of 661W cells. The expression of Faim2 is triggered, at least in part, by Fas-receptor activation and subsequent ERK signaling. Our findings identify a novel protective pathway that auto-regulates Fas-induced photoreceptor apoptosis in vitro. Modulation of this pathway to increase Faim2 expression may be a potential therapeutic option to prevent photoreceptor death. PMID:23029562

  10. Preventing Friction Induced Chondrocyte Apoptosis: A Comparison of Human Synovial Fluid and Hylan G-F 20

    PubMed Central

    Waller, Kimberly A; Zhang, Ling X; Fleming, Braden C; Jay, Gregory D

    2013-01-01

    Objectives Symptomatic osteoarthritis (OA) is a common painful disease with limited treatment options. A rising number of OA patients have been treated with intraarticular injections of hyaluronic acid, including the high molecular weight hylan G-F 20, which is injected following arthrocentesis. This study investigated the effectiveness of hylan G-F 20 to lower coefficient of friction (COF) and prevent chondrocyte apoptosis in vitro. Methods A disc-on-disc bovine cartilage bearing was used to measure the static and kinetic COF when lubricated with hylan G-F 20, human synovial fluid (HSF) and phosphate buffered saline (PBS). Following friction testing, we stained paraffin embedded sections of these cartilage bearings for activated caspase-3, a marker of apoptosis. Results Bearings lubricated with hylan G-F 20 had kinetic COF values that were similar to bearings lubricated with PBS, but significantly higher than those lubricated with HSF. There were no significant differences in static COF values in bearings lubricated with hylan G-F 20 as compared to PBS or HSF. However, bearings lubricated with HSF had a significantly lower static COF values compared to bearings lubricated with PBS. The mean percentage of caspase-3 positive chondrocytes in the superficial and upper intermediate zones of bearings lubricated with hylan G-F 20 were significantly higher when compared to bearings lubricated with HSF or unloaded controls, but significantly lower than those lubricated with PBS. Conclusion These findings indicate that joint lubrication may prevent chondrocyte apoptosis by lowering the COF. Furthermore, removal of synovial fluid prior to hylan G-F 20 injection may be detrimental to cartilage health. PMID:22660808

  11. TGF-β1 prevents simulated ischemia/reperfusion-induced cardiac fibroblast apoptosis by activation of both canonical and non-canonical signaling pathways.

    PubMed

    Vivar, Raúl; Humeres, Claudio; Ayala, Pedro; Olmedo, Ivonne; Catalán, Mabel; García, Lorena; Lavandero, Sergio; Díaz-Araya, Guillermo

    2013-06-01

    Ischemia/reperfusion injury is a major cause of myocardial death. In the heart, cardiac fibroblasts play a critical role in healing post myocardial infarction. TGF-β1 has shown cardioprotective effects in cardiac damage; however, if TGF-β1 can prevent cardiac fibroblast death triggered by ischemia/reperfusion is unknown. Therefore, we test this hypothesis, and whether the canonical and/or non-canonical TGF-β1 signaling pathways are involved in this protective effect. Cultured rat cardiac fibroblasts were subjected to simulated ischemia/reperfusion. Cell viability was analyzed by trypan blue exclusion and propidium iodide by flow cytometry. The processing of procaspases 8, 9 and 3 to their active forms was assessed by Western blot, whereas subG1 population was evaluated by flow cytometry. Levels of total and phosphorylated forms of ERK1/2, Akt and Smad2/3 were determined by Western blot. The role of these signaling pathways on the protective effect of TGF-β1 was studied using specific chemical inhibitors. Simulated ischemia over 8h triggers a significant cardiac fibroblast death, which increased by reperfusion, with apoptosis actively involved. These effects were only prevented by the addition of TGF-β1 during reperfusion. TGF-β1 pretreatment increased the levels of phosphorylated forms of ERK1/2, Akt and Smad2/3. The inhibition of ERK1/2, Akt and Smad3 also blocked the preventive effects of TGF-β1 on cardiac fibroblast apoptosis induced by simulated ischemia/reperfusion. Overall, our data suggest that TGF-β1 prevents cardiac fibroblast apoptosis induced by simulated ischemia-reperfusion through the canonical (Smad3) and non canonical (ERK1/2 and Akt) signaling pathways.

  12. TGF-β1 prevents simulated ischemia/reperfusion-induced cardiac fibroblast apoptosis by activation of both canonical and non-canonical signaling pathways.

    PubMed

    Vivar, Raúl; Humeres, Claudio; Ayala, Pedro; Olmedo, Ivonne; Catalán, Mabel; García, Lorena; Lavandero, Sergio; Díaz-Araya, Guillermo

    2013-06-01

    Ischemia/reperfusion injury is a major cause of myocardial death. In the heart, cardiac fibroblasts play a critical role in healing post myocardial infarction. TGF-β1 has shown cardioprotective effects in cardiac damage; however, if TGF-β1 can prevent cardiac fibroblast death triggered by ischemia/reperfusion is unknown. Therefore, we test this hypothesis, and whether the canonical and/or non-canonical TGF-β1 signaling pathways are involved in this protective effect. Cultured rat cardiac fibroblasts were subjected to simulated ischemia/reperfusion. Cell viability was analyzed by trypan blue exclusion and propidium iodide by flow cytometry. The processing of procaspases 8, 9 and 3 to their active forms was assessed by Western blot, whereas subG1 population was evaluated by flow cytometry. Levels of total and phosphorylated forms of ERK1/2, Akt and Smad2/3 were determined by Western blot. The role of these signaling pathways on the protective effect of TGF-β1 was studied using specific chemical inhibitors. Simulated ischemia over 8h triggers a significant cardiac fibroblast death, which increased by reperfusion, with apoptosis actively involved. These effects were only prevented by the addition of TGF-β1 during reperfusion. TGF-β1 pretreatment increased the levels of phosphorylated forms of ERK1/2, Akt and Smad2/3. The inhibition of ERK1/2, Akt and Smad3 also blocked the preventive effects of TGF-β1 on cardiac fibroblast apoptosis induced by simulated ischemia/reperfusion. Overall, our data suggest that TGF-β1 prevents cardiac fibroblast apoptosis induced by simulated ischemia-reperfusion through the canonical (Smad3) and non canonical (ERK1/2 and Akt) signaling pathways. PMID:23416528

  13. Eugenol precludes cutaneous chemical carcinogenesis in mouse by preventing oxidative stress and inflammation and by inducing apoptosis.

    PubMed

    Kaur, Gurpreet; Athar, Mohammad; Alam, M Sarwar

    2010-03-01

    The present study was designed to investigate the protective efficacy of eugenol against skin cancer and probe into the mechanistic aspects. Skin tumors were initiated by applying 160 nmol DMBA and promoted by twice weekly applications of 8.5 nmol TPA for 28 wk. All mice developed tumors by 13 wk of promotion. However, in mice pretreated with 30 microL eugenol, no tumors were detected until 8 wk (following anti-initiation protocol) and until 14 wk (following antipromotion protocol) of tumor promotion. PCNA and TUNEL immunohistochemistry of tumors revealed eugenol to ameliorate cell proliferation and elevate apoptosis respectively. The effect of eugenol was assessed on specific stages of carcinogenesis. Initiation with DMBA led to a significant upregulation of p53 expression with a concomitant increase in p21(WAF1) levels in epidermal cells indicating induction of damage to the DNA. However, pretreatment with eugenol led to overexpression of these genes, which probably helped stimulate apoptosis of the initiated cells. To ascertain the molecular mechanisms implicated in the antitumor promoting activity of eugenol, its effect was investigated on markers of tumor promotion and inflammation: ODC activity and iNOS and COX-2 expression, and on levels of proinflammatory cytokines (IL-6, TNF-alpha, and PGE(2)). Eugenol markedly inhibited all. Eugenol also inhibited the upstream signaling molecule: NF-kappaB, which regulates the expression of these genes. TPA-induced depletion of cutaneous GSH and antioxidant enzymes armory was also precluded by eugenol. From these results, it could be concluded that eugenol markedly protects against chemically induced skin cancer and acts possibly by virtue of its antiproliferative, anti-inflammatory, and antioxidant activities.

  14. Quercetin-3-O-(2"-galloyl)-α-l-rhamnopyranoside prevents TRAIL-induced apoptosis in human keratinocytes by suppressing the caspase-8- and Bid-pathways and the mitochondrial pathway.

    PubMed

    Kim, Yun Jeong; Jung, Eun Byul; Seo, Seong Jun; Park, Kwan Hee; Lee, Min Won; Lee, Chung Soo

    2013-08-25

    Quercetin and its derivatives have antioxidant and anti-inflammatory effects. Nevertheless, in human keratinocytes, compared to the reports on other toxic insults, researches on the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis that may be involved in skin diseases are rare. Furthermore, the effect of quercetin-3-O-(2"-galloyl)-α-l-rhamnopyranoside (QGR), a new quercetin derivative, on TRAIL-induced apoptosis in keratinocytes has not been studied. In this respect, we investigated the effect of QGR on TRAIL-induced apoptosis in human keratinocytes. TRAIL triggers apoptosis by inducing a decrease in Bid, Bcl-2, Bcl-xL and survivin protein levels, increase in Bax and VDAC1 levels, loss of the mitochondrial transmembrane potential, release of cytochrome c, activation of caspases (-8, -9 and -3), cleavage of PARP-1, and an increase in the tumor suppressor p53 levels. Treatment with QGR prevented TRAIL-induced apoptosis-related protein activation, formation of reactive oxygen species, nuclear damage, and cell death. In contrast, quercetin induces cytotoxicity and had an additive effect on TRAIL-induced apoptosis-related protein activation and cell death. These results suggest that the QGR, unlike quercetin, may reduce TRAIL-induced apoptosis in human keratinocytes by suppressing the activation of the caspase-8- and Bid-pathways and the mitochondria-mediated cell death pathway, which is associated with the formation of reactive oxygen species. These data suggest that QGR could be effective in the prevention of TRAIL-induced apoptosis-mediated skin diseases.

  15. Neferine prevents NF-κB translocation and protects muscle cells from oxidative stress and apoptosis induced by hypoxia.

    PubMed

    Baskaran, Rathinasamy; Poornima, Paramasivan; Huang, Chih Yang; Padma, Viswanadha Vijaya

    2016-07-01

    Neferine (Nef), a bisbenzylisoquinoline alkaloid from lotus seed embryo has a wide range of pharmacological activities. Possible molecular mechanism for the cytoprotective action of Nef during hypoxic stress has not been explored till now. Hence, this is an attempt to elucidate the molecular mechanism involved in the Nef mediated cytoprotection on hypoxia-induced cell injury. Cytoprotective dose of Nef in muscle cells (Human rhabdomyosarcoma cells) exposed to hypoxia was determined by MTT assay. Nef at 500 nM offered better cytoprotection and was used for all the experiments. ROS, intracellular calcium accumulation and mitochondrial membrane (ΔψM) potential were measured using fluorescent probes. Further, we evaluated the effect Nef on hypoxia induced inflammatory and apoptotic responses by FACS and analyzing the expression patterns of NF-κB, COX-2, HIF-1α, caspase-3, caspase-9, Bcl2, and Bax. The results of this study revealed that pretreatment of the cells with Nef significantly decreased the ΔψM and ROS in the cells subjected to hypoxia. Further, Nef inhibited NF-κB there by inhibiting the expression of its downstream regulator COX-2, while it induced the functional HIF-1α expression. The results also indicate that Nef significantly inhibited the ROS dependent mitochondrial mediated apoptosis induced during hypoxia. The cytoprotection elicited by Nef in a model of hypoxia induced cell death involves both anti-inflammatory and anti-apoptotic response. These results suggest that Nef may be used as prophylactic agent against the hypoxic challenge. © 2016 BioFactors, 42(4):407-417, 2016. PMID:27041079

  16. 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.

  17. Research Advances on Pathways of Nickel-Induced Apoptosis.

    PubMed

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

    2016-01-01

    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

  18. 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

  19. Phosphorylated AKT inhibits the apoptosis induced by DRAM-mediated mitophagy in hepatocellular carcinoma by preventing the translocation of DRAM to mitochondria.

    PubMed

    Liu, K; Shi, Y; Guo, X H; Ouyang, Y B; Wang, S S; Liu, D J; Wang, A N; Li, N; Chen, D X

    2014-01-01

    Increasing autophagy is beneficial for curing hepatocellular carcinoma (HCC). Damage-regulated autophagy modulator (DRAM) was recently reported to induce apoptosis by mediating autophagy. However, the effects of DRAM-mediated autophagy on apoptosis in HCC cells remain unclear. In this study, normal hepatocytes (7702) and HCC cell lines (HepG2, Hep3B and Huh7) were starved for 48 h. Starvation induced apoptosis and autophagy in all cell lines. We determined that starvation also induced DRAM expression and DRAM-mediated autophagy in both normal hepatocytes and HCC cells. However, DRAM-mediated autophagy was involved in apoptosis in normal hepatocytes but not in HCC cells, suggesting that DRAM-mediated autophagy fails to induce apoptosis in hepatoma in response to starvation. Immunoblot and immunofluorescence assays demonstrated that DRAM translocated to mitochondria and induced mitophagy, which led to apoptosis in 7702 cells. In HCC cells, starvation also activated the phosphatidylinositol 3-kinase (PI3K)/AKT pathway, which blocks the translocation of DRAM to mitochondria through the binding of p-AKT to DRAM in the cytoplasm. Inactivation of the PI3K/AKT pathway rescued DRAM translocation to mitochondria; subsequently, mitochondrial DRAM induced apoptosis in HCC cells by mediating mitophagy. Our findings open new avenues for the investigation of the mechanisms of DRAM-mediated autophagy and suggest that promoting DRAM-mediated autophagy together with PI3K/AKT inhibition might be more effective for autophagy-based therapy in hepatoma. PMID:24556693

  20. Nuclear glutathione S-transferase pi prevents apoptosis by reducing the oxidative stress-induced formation of exocyclic DNA products.

    PubMed

    Kamada, Kensaku; Goto, Shinji; Okunaga, Tomohiro; Ihara, Yoshito; Tsuji, Kentaro; Kawai, Yoshichika; Uchida, Koji; Osawa, Toshihiko; Matsuo, Takayuki; Nagata, Izumi; Kondo, Takahito

    2004-12-01

    We previously found that nuclear glutathione S-transferase pi (GSTpi) accumulates in cancer cells resistant to anticancer drugs, suggesting that it has a role in the acquisition of resistance to anticancer drugs. In the present study, the effect of oxidative stress on the nuclear translocation of GSTpi and its role in the protection of DNA from damage were investigated. In human colonic cancer HCT8 cells, the hydrogen peroxide (H(2)O(2))-induced increase in nuclear condensation, the population of sub-G(1) peak, and the number of TUNEL-positive cells were observed in cells pretreated with edible mushroom lectin, an inhibitor of the nuclear transport of GSTpi. The DNA damage and the formation of lipid peroxide were dependent on the dose of H(2)O(2) and the incubation time. Immunological analysis showed that H(2)O(2) induced the nuclear accumulation of GSTpi but not of glutathione peroxidase. Formation of the 7-(2-oxo-hepyl)-substituted 1,N(2)-etheno-2'-deoxyguanosine adduct by the reaction of 13-hydroperoxyoctadecadienoic acid (13-HPODE) with 2'-deoxyguanosine was inhibited by GSTpi in the presence of glutathione. The conjugation product of 4-oxo-2-nonenal, a lipid aldehyde of 13-HPODE, with GSH in the presence of GSTpi, was identified by LS/MS. These results suggested that nuclear GSTpi prevents H(2)O(2)-induced DNA damage by scavenging the formation of lipid-peroxide-modified DNA. PMID:15528046

  1. Nuclear glutathione S-transferase pi prevents apoptosis by reducing the oxidative stress-induced formation of exocyclic DNA products.

    PubMed

    Kamada, Kensaku; Goto, Shinji; Okunaga, Tomohiro; Ihara, Yoshito; Tsuji, Kentaro; Kawai, Yoshichika; Uchida, Koji; Osawa, Toshihiko; Matsuo, Takayuki; Nagata, Izumi; Kondo, Takahito

    2004-12-01

    We previously found that nuclear glutathione S-transferase pi (GSTpi) accumulates in cancer cells resistant to anticancer drugs, suggesting that it has a role in the acquisition of resistance to anticancer drugs. In the present study, the effect of oxidative stress on the nuclear translocation of GSTpi and its role in the protection of DNA from damage were investigated. In human colonic cancer HCT8 cells, the hydrogen peroxide (H(2)O(2))-induced increase in nuclear condensation, the population of sub-G(1) peak, and the number of TUNEL-positive cells were observed in cells pretreated with edible mushroom lectin, an inhibitor of the nuclear transport of GSTpi. The DNA damage and the formation of lipid peroxide were dependent on the dose of H(2)O(2) and the incubation time. Immunological analysis showed that H(2)O(2) induced the nuclear accumulation of GSTpi but not of glutathione peroxidase. Formation of the 7-(2-oxo-hepyl)-substituted 1,N(2)-etheno-2'-deoxyguanosine adduct by the reaction of 13-hydroperoxyoctadecadienoic acid (13-HPODE) with 2'-deoxyguanosine was inhibited by GSTpi in the presence of glutathione. The conjugation product of 4-oxo-2-nonenal, a lipid aldehyde of 13-HPODE, with GSH in the presence of GSTpi, was identified by LS/MS. These results suggested that nuclear GSTpi prevents H(2)O(2)-induced DNA damage by scavenging the formation of lipid-peroxide-modified DNA.

  2. Glucose-Dependent Insulinotropic Peptide Prevents Serum Deprivation-Induced Apoptosis in Human Bone Marrow-Derived Mesenchymal Stem Cells and Osteoblastic Cells.

    PubMed

    Berlier, J L; Kharroubi, I; Zhang, J; Dalla Valle, A; Rigutto, S; Mathieu, M; Gangji, V; Rasschaert, J

    2015-12-01

    Human bone marrow-derived mesenchymal stem cells (hBMSC) are able to differentiate into cells of connective tissue lineages, including bone and cartilage. They are therefore considered as a promising tool for the treatment of bone degenerative diseases. One of the major issues in regenerative cell therapy is the biosafety of fetal bovine serum used for cell culture. Therefore, the development of a culture medium devoid of serum but preserving hBMSC viability will be of clinical value. The glucose-dependent insulinotropic peptide (GIP) has an anti-apoptotic action in insulin-producing cells. Interestingly, GIP also exerts beneficial effects on bone turnover by acting on osteoblasts and osteoclasts. We therefore evaluated the ability of GIP to prevent cell death in osteoblastic cells cultured in serum-free conditions. In hBMSC and SaOS-2 cells, activation of the GIP receptor increased intracellular cAMP levels. Serum deprivation induced apoptosis in SaOS-2 and hBMSC that was reduced by 30 and 50 %, respectively, in the presence of GIP. The protective effect of GIP involves activation of the adenylate cyclase pathway and inhibition of caspases 3/7 activation. These findings demonstrate that GIP exerts a protective action against apoptosis in hBMSC and suggest a novel approach to preserve viability of hBMSC cultured in the absence of serum. PMID:26254594

  3. Hydroxyl radical scavenger ameliorates cisplatin-induced nephrotoxicity by preventing oxidative stress, redox state unbalance, impairment of energetic metabolism and apoptosis in rat kidney mitochondria.

    PubMed

    Santos, N A G; Bezerra, C S Catão; Martins, N M; Curti, C; Bianchi, M L P; Santos, A C

    2008-01-01

    Nephrotoxicity is the major dose-limiting factor of cisplatin chemotherapy. Reactive oxygen species generated in mitochondria are thought to be the main cause of cellular damage in such injury. The present study examined, in vivo, the protective potential of the hydroxyl radical scavenger dimethylthiourea (DMTU) against cisplatin-induced effects on renal mitochondrial bioenergetics, redox state and oxidative stress. Adult male Wistar rats (200 to 220 g) were divided into four groups of eight animals each. The control group was treated only with an intraperitoneal (i.p.) injection of saline solution (1 ml/100 g body weight). The second group was given only DMTU (500 mg/kg body weight, i.p, followed by 125 mg/Kg, i.p., twice a day until they were killed). The third group was given a single injection of cisplatin (10 mg/kg body weight, i.p.). The fourth group was given DMTU (500 mg/kg body weight, i.p.), just before the cisplatin injection (10 mg/kg body weight, i.p.), followed by injections of DMTU (125 mg/kg body weight, i.p.) twice a day until they were killed. Animals were killed 72 h after the treatment. Besides not presenting any direct effect on mitochondria, DMTU substantially inhibited cisplatin-induced mitochondrial injury and cellular death by apoptosis, suppressing the occurrence of acute renal failure. All the following cisplatin-induced effects were prevented by DMTU: (1) increased plasmatic levels of creatinine and blood urea nitrogen (BUN); (2) decreased ATP content, calcium uptake and electrochemical potential; (3) oxidation of lipids, including cardiolipin; and oxidation of proteins, including sulfhydryl, and aconitase enzyme, as well as accumulation of carbonyl proteins; (4) depletion of the antioxidant defense (NADPH and GSH) and (5) increased activity of the apoptosis executioner caspase-3. Our findings show the important role played by mitochondria and hydroxyl radicals in cisplatin-induced nephrotoxicity, as well as the effectiveness of DMTU in

  4. Hydroxyl radical scavenger ameliorates cisplatin-induced nephrotoxicity by preventing oxidative stress, redox state unbalance, impairment of energetic metabolism and apoptosis in rat kidney mitochondria.

    PubMed

    Santos, N A G; Bezerra, C S Catão; Martins, N M; Curti, C; Bianchi, M L P; Santos, A C

    2008-01-01

    Nephrotoxicity is the major dose-limiting factor of cisplatin chemotherapy. Reactive oxygen species generated in mitochondria are thought to be the main cause of cellular damage in such injury. The present study examined, in vivo, the protective potential of the hydroxyl radical scavenger dimethylthiourea (DMTU) against cisplatin-induced effects on renal mitochondrial bioenergetics, redox state and oxidative stress. Adult male Wistar rats (200 to 220 g) were divided into four groups of eight animals each. The control group was treated only with an intraperitoneal (i.p.) injection of saline solution (1 ml/100 g body weight). The second group was given only DMTU (500 mg/kg body weight, i.p, followed by 125 mg/Kg, i.p., twice a day until they were killed). The third group was given a single injection of cisplatin (10 mg/kg body weight, i.p.). The fourth group was given DMTU (500 mg/kg body weight, i.p.), just before the cisplatin injection (10 mg/kg body weight, i.p.), followed by injections of DMTU (125 mg/kg body weight, i.p.) twice a day until they were killed. Animals were killed 72 h after the treatment. Besides not presenting any direct effect on mitochondria, DMTU substantially inhibited cisplatin-induced mitochondrial injury and cellular death by apoptosis, suppressing the occurrence of acute renal failure. All the following cisplatin-induced effects were prevented by DMTU: (1) increased plasmatic levels of creatinine and blood urea nitrogen (BUN); (2) decreased ATP content, calcium uptake and electrochemical potential; (3) oxidation of lipids, including cardiolipin; and oxidation of proteins, including sulfhydryl, and aconitase enzyme, as well as accumulation of carbonyl proteins; (4) depletion of the antioxidant defense (NADPH and GSH) and (5) increased activity of the apoptosis executioner caspase-3. Our findings show the important role played by mitochondria and hydroxyl radicals in cisplatin-induced nephrotoxicity, as well as the effectiveness of DMTU in

  5. N-Acetyl Cysteine Depletes Reactive Oxygen Species and Prevents Dental Monomer-Induced Intrinsic Mitochondrial Apoptosis In Vitro in Human Dental Pulp Cells

    PubMed Central

    Li, Jing; Shan, Lequn; Liu, Qian; Liu, Ying; Song, Qian; Yu, Fan; Yu, Haohan; Liu, Huan; Huang, Li; Chen, Jihua

    2016-01-01

    Purpose To investigate the involvement of intrinsic mitochondrial apoptosis in dental monomer-induced cytotoxicity and the influences of N-acetyl cysteine (NAC) on this process. Methods Human dental pulp cells (hDPCs) were exposed to several dental monomers in the absence or presence of NAC, and cell viability, intracellular redox balance, morphology and function of mitochondria and key indicators of intrinsic mitochondrial apoptosis were evaluated using various commercial kits. Results Dental monomers exerted dose-dependent cytotoxic effects on hDPCs. Concomitant to the over-production of reactive oxygen species (ROS) and depletion of glutathione (GSH), differential changes in activities of superoxide dismutase, glutathione peroxidase, and catalase were detected. Apoptosis, as indicated by positive Annexin V/propidium iodide (PI) staining and activation of caspase-3, was observed after dental monomer treatment. Dental monomers impaired the morphology and function of mitochondria, and induced intrinsic mitochondrial apoptosis in hDPCs via up-regulation of p53, Bax and cleaved caspase-3, and down-regulation of Bcl-2. NAC restored cell viability, relieved oxidative stress and blocked the apoptotic effects of dental monomers. Conclusions Dental monomers induced oxidative stress and mitochondrial intrinsic apoptosis in hDPCs. NAC could reduce the oxidative stress and thus protect hDPCs against dental monomer-induced apoptosis. PMID:26808507

  6. Analysis of fumonisin B1-induced apoptosis.

    PubMed Central

    Jones, C; Ciacci-Zanella, J R; Zhang, Y; Henderson, G; Dickman, M

    2001-01-01

    Fumonisins are mycotoxins produced by Fusarium moniliforme, a prevalent fungus that infects corn and other cereal grains. Fumonisin B1(FB1 is the most common mycotoxin produced by F. moniliforme, suggesting it has toxicologic significance. The structure of FB1 resembles sphingoid bases, and it inhibits ceramide synthase. Because sphingoid bases regulate cell growth, differentiation, transformation, and apoptosis, it is not surprising to find that FB1 can alter growth of certain mammalian cells. Previous studies concluded FB1-induced apoptosis, or cell cycle arrest, in African green monkey kidney fibroblasts (CV-1). In this study we have identified genes that inhibit FB1 induced apoptosis in CV-1 cells and two mouse embryo fibroblasts (MEF). A baculovirus gene, inhibitor of apoptosis (CpIAP), protected these cells from apoptosis. CpIAP blocks apoptosis induced by the tumor necrosis factor (TNF) pathway as well as other mechanisms. Further support for the involvement of the TNF signal transduction pathway in FB1 induced apoptosis was the cleavage of caspase 8. Inhibition of caspases by the baculovirus gene (italic)p35 also inhibited FB1-induced apoptosis. The tumor suppressor gene p53 was not required for FB1 induced apoptosis because p53-/- MEF undergo apoptosis following FB1 treatment. Furthermore, Bcl-2 was not an effective inhibitor of FB1-induced apoptosis in CV-1 cells or p53+/+ MEF. In summary, these results provide new information to help understand the mechanism by which FB1 induces apoptosis. PMID:11359701

  7. Post-ischaemic mild hypothermia inhibits apoptosis in the penumbral region by reducing neuronal nitric oxide synthase activity and thereby preventing endothelin-1-induced hydroxyl radical formation.

    PubMed

    Van Hemelrijck, An; Hachimi-Idrissi, Said; Sarre, Sophie; Ebinger, Guy; Michotte, Yvette

    2005-09-01

    Previously, we showed that treatment with resuscitative, post-ischaemic mild hypothermia (34 degrees C for 2 h) reduced apoptosis in the penumbra (cortex), but not in the core (striatum) of an endothelin-1 (Et-1)-induced focal cerebral infarct in the anaesthetized rat. Therefore, the purpose of this study was to investigate by which pathways resuscitative mild hypothermia exerts its neuroprotective effect in this model. The amino acids glutamate, serine, glutamine, alanine, taurine, arginine and the NO-related compound citrulline were sampled from the striatum and cortex of the ischaemic hemisphere using in vivo microdialysis. The in vivo salicylate trapping method was applied for monitoring hydroxyl radical formation via 2,3 dihydroxybenzoic acid (2,3 DHBA) detection. Caspase-3, neuronal nitric oxide synthase (nNOS) immunoreactivity and the volume of ischaemic damage were determined 24 h after the insult. In both the striatum and the cortex, Et-1-induced increases in glutamate, taurine and alanine were refractory to mild hypothermia. However, mild hypothermia significantly attenuated the ischaemia-induced 2,3 DHBA levels and the nNOS immunoreactivity in the cortex, but not in the striatum. These observations were associated with a decreased caspase-3 immunoreactivity. These results suggest that mild hypothermia exerts its neuroprotective effect in the penumbra partially by reducing nNOS activity and thereby preventing oxidative stress. Furthermore, we confirm our previous findings that the neuroprotective effect of resuscitative hypothermia is not mediated by changes in ischaemia-induced amino acid release as they could not be associated with the ischaemia-induced damage in the Et-1 rat model.

  8. Retinoic Acid Induced-Autophagic Flux Inhibits ER-Stress Dependent Apoptosis and Prevents Disruption of Blood-Spinal Cord Barrier after Spinal Cord Injury

    PubMed Central

    Zhou, Yulong; Zhang, Hongyu; Zheng, Binbin; Ye, Libing; Zhu, Sipin; Johnson, Noah R; Wang, Zhouguang; Wei, Xiaojie; Chen, Daqing; Cao, Guodong; Fu, Xiaobing; Li, Xiaokun; Xu, Hua-Zi; Xiao, Jian

    2016-01-01

    Spinal cord injury (SCI) induces the disruption of the blood-spinal cord barrier (BSCB) which leads to infiltration of blood cells, an inflammatory response, and neuronal cell death, resulting spinal cord secondary damage. Retinoic acid (RA) has a neuroprotective effect in both ischemic brain injury and SCI, however the relationship between BSCB disruption and RA in SCI is still unclear. In this study, we demonstrated that autophagy and ER stress are involved in the protective effect of RA on the BSCB. RA attenuated BSCB permeability and decreased the loss of tight junction (TJ) molecules such as P120, β-catenin, Occludin and Claudin5 after injury in vivo as well as in Brain Microvascular Endothelial Cells (BMECs). Moreover, RA administration improved functional recovery in the rat model of SCI. RA inhibited the expression of CHOP and caspase-12 by induction of autophagic flux. However, RA had no significant effect on protein expression of GRP78 and PDI. Furthermore, combining RA with the autophagy inhibitor chloroquine (CQ) partially abolished its protective effect on the BSCB via exacerbated ER stress and subsequent loss of tight junctions. Taken together, the neuroprotective role of RA in recovery from SCI is related to prevention of of BSCB disruption via the activation of autophagic flux and the inhibition of ER stress-induced cell apoptosis. These findings lay the groundwork for future translational studies of RA for CNS diseases, especially those related to BSCB disruption. PMID:26722220

  9. Retinoic Acid Induced-Autophagic Flux Inhibits ER-Stress Dependent Apoptosis and Prevents Disruption of Blood-Spinal Cord Barrier after Spinal Cord Injury.

    PubMed

    Zhou, Yulong; Zhang, Hongyu; Zheng, Binbin; Ye, Libing; Zhu, Sipin; Johnson, Noah R; Wang, Zhouguang; Wei, Xiaojie; Chen, Daqing; Cao, Guodong; Fu, Xiaobing; Li, Xiaokun; Xu, Hua-Zi; Xiao, Jian

    2016-01-01

    Spinal cord injury (SCI) induces the disruption of the blood-spinal cord barrier (BSCB) which leads to infiltration of blood cells, an inflammatory response, and neuronal cell death, resulting spinal cord secondary damage. Retinoic acid (RA) has a neuroprotective effect in both ischemic brain injury and SCI, however the relationship between BSCB disruption and RA in SCI is still unclear. In this study, we demonstrated that autophagy and ER stress are involved in the protective effect of RA on the BSCB. RA attenuated BSCB permeability and decreased the loss of tight junction (TJ) molecules such as P120, β-catenin, Occludin and Claudin5 after injury in vivo as well as in Brain Microvascular Endothelial Cells (BMECs). Moreover, RA administration improved functional recovery in the rat model of SCI. RA inhibited the expression of CHOP and caspase-12 by induction of autophagic flux. However, RA had no significant effect on protein expression of GRP78 and PDI. Furthermore, combining RA with the autophagy inhibitor chloroquine (CQ) partially abolished its protective effect on the BSCB via exacerbated ER stress and subsequent loss of tight junctions. Taken together, the neuroprotective role of RA in recovery from SCI is related to prevention of of BSCB disruption via the activation of autophagic flux and the inhibition of ER stress-induced cell apoptosis. These findings lay the groundwork for future translational studies of RA for CNS diseases, especially those related to BSCB disruption.

  10. 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

  11. Platelets induce apoptosis via membrane-bound FasL.

    PubMed

    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; Langer, Harald F

    2015-09-17

    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(+) FasL(fl/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.

  12. Mechanisms of p53-induced apoptosis.

    PubMed

    Bennett, M R

    1999-10-01

    The p53 tumour suppressor gene functions in both cell cycle arrest and apoptosis. Despite considerable advances in understanding as to how p53 regulates growth arrest, the mechanisms by which p53 regulates apoptosis are only just emerging. In particular, there appears to be a structural and functional separation between the ability of p53 to induce growth arrest and apoptosis. This review examines the interactions between p53-induced growth arrest and apoptosis, and the mechanisms of p53-induced apoptosis, both via induction of p53 transcriptional targets and via nontranscriptional mechanisms.

  13. [6]-Gingerol induces caspase-dependent apoptosis and prevents PMA-induced proliferation in colon cancer cells by inhibiting MAPK/AP-1 signaling.

    PubMed

    Radhakrishnan, E K; Bava, Smitha V; Narayanan, Sai Shyam; Nath, Lekshmi R; Thulasidasan, Arun Kumar T; Soniya, Eppurathu Vasudevan; Anto, Ruby John

    2014-01-01

    We report mechanism-based evidence for the anticancer and chemopreventive efficacy of [6]-gingerol, the major active principle of the medicinal plant, Ginger (Zingiber officinale), in colon cancer cells. The compound was evaluated in two human colon cancer cell lines for its cytotoxic effect and the most sensitive cell line, SW-480, was selected for the mechanistic evaluation of its anticancer and chemopreventive efficacy. The non-toxic nature of [6]-gingerol was confirmed by viability assays on rapidly dividing normal mouse colon cells. [6]-gingerol inhibited cell proliferation and induced apoptosis as evidenced by externalization of phosphatidyl serine in SW-480, while the normal colon cells were unaffected. Sensitivity to [6]-gingerol in SW-480 cells was associated with activation of caspases 8, 9, 3 &7 and cleavage of PARP, which attests induction of apoptotic cell death. Mechanistically, [6]-gingerol down-regulated Phorbol Myristate Acetate (PMA) induced phosphorylation of ERK1/2 and JNK MAP kinases and activation of AP-1 transcription factor, but had only little effects on phosphorylation of p38 MAP kinase and activation of NF-kappa B. Additionally, it complemented the inhibitors of either ERK1/2 or JNK MAP kinase in bringing down the PMA-induced cell proliferation in SW-480 cells. We report the inhibition of ERK1/2/JNK/AP-1 pathway as a possible mechanism behind the anticancer as well as chemopreventive efficacy of [6]-gingerol against colon cancer.

  14. Luteolin Prevents H2O2-Induced Apoptosis in H9C2 Cells through Modulating Akt-P53/Mdm2 Signaling Pathway.

    PubMed

    Chang, Hong; Li, Chun; Huo, Kuiyuan; Wang, Qiyan; Lu, Linghui; Zhang, Qian; Wang, Yong; Wang, Wei

    2016-01-01

    Introduction. Luteolin, a falconoid compound in many Chinese herbs and formula, plays important roles in cardiovascular diseases. The underlying mechanism of luteolin remains to be further elaborated. Methods. A model of hydrogen peroxide- (H2O2-) induced H9C2 cells apoptosis was established. Cell viabilities were examined with an MTT assay. 2',7'-Dichlorofluorescin diacetate (DCFH-DA) and flow cytometry were used to detect ROS level and apoptosis rate, respectively. The expressions of signaling proteins related to apoptosis were analyzed by western blot and mRNA levels were detected by real-time polymerase chain reaction (PCR). Quercetin was applied as positive drug. Results. Incubation with various concentrations of H2O2 (0, 50, 100, and 200 μM) for 1 h caused dose-dependent loss of cell viability and 100 μM H2O2 reduced the cell viability to approximately 50%. Treatments with luteolin and quercetin protected cells from H2O2-induced cytotoxicity and reduced cellular ROS level and apoptosis rate. Moreover, luteolin could downregulate the expressions of Bax, caspase-8, cleaved-caspase-3, and p53 in apoptotic signaling pathway. Further study showed that the expressions of Akt, Bcl-2, and Mdm2 were upregulated by luteolin. Conclusion. Luteolin protects H9C2 cells from H2O2-induced apoptosis. The protective and antiapoptotic effects of luteolin could be mediated by regulating the Akt-P53/Mdm2 apoptotic pathway. PMID:27525270

  15. Ginsenoside Rg1 prevents SK-N-SH neuroblastoma cell apoptosis induced by supernatant from Aβ1-40-stimulated THP-1 monocytes.

    PubMed

    Li, Wei; Chu, Yanqi; Zhang, Lan; Yin, Linlin; Li, Lin

    2012-08-01

    Excessive accumulation of amyloid-β (Aβ) has been proposed as a pivotal event in Alzheimer's disease (AD) pathogenesis. Possible mechanisms underlying Aβ-induced neurotoxicity include inflammation and apoptosis. Here, the protective effect of ginsenoside Rg1 (GRg1) on neuronal damage was examined in an in vitro inflammatory neurodegeneration model. Supernatant from Aβ(1-40)-stimulated THP-1 monocytes was added to SK-N-SH neuroblastoma cell culture medium. Incubation of SK-N-SH cells with cell-free supernatant from Aβ(1-40) (125nM)-treated THP-1 monocytes for 24 h significantly increased lactate dehydrogenase (LDH) release, cell apoptosis, Bax and caspase-3 expression in SK-N-SH cells. However, pretreating THP-1 monocytes with GRg1 (50, 100 or 150 μM) for 30 min markedly reduced IL-1β, IL-8 and TNF-α levels in Aβ(1-40)-stimulated supernatant. LDH release, cell apoptosis, Bax and caspase-3 expression in SK-N-SH cells were significantly decreased when cultured with cell-free supernatant from Aβ(1-40)-stimulated THP-1 monocytes that were pretreated with GRg1. The results suggest that Aβ(1-40)-induced neuronal injury and apoptosis may be mediated by inflammatory monocyte reactions, and GRg1 exerts a protective effect against Aβ(1-40)-induced neuronal injury and apoptosis, likely through its anti-inflammatory mechanism.

  16. Resveratrol Induces Apoptosis-Like Death and Prevents In Vitro and In Vivo Virulence of Entamoeba histolytica

    PubMed Central

    Pais-Morales, Jonnatan; Betanzos, Abigail; García-Rivera, Guillermina; Chávez-Munguía, Bibiana; Shibayama, Mineko; Orozco, Esther

    2016-01-01

    Entamoeba histolytica causes amoebiasis, an infection that kills 100,000 individuals each year. Metronidazole and its derivatives are currently used against this protozoan, but these drugs present adverse effects on human health. Here, we investigated the effect of resveratrol (a natural compound) on E. histolytica trophozoites viability, as well as its influence on the parasite virulence. Trophozoites growth was arrested by 72 μM resveratrol and the IC50 was determined as 220 μM at 48 h. Cells appeared smaller, rounded and in clusters, with debris-containing vacuoles and with abnormally condensed chromatin. Resveratrol triggered reactive oxygen species production. It caused lipid peroxidation and produced phosphatidylserine externalization and DNA fragmentation this latter evidenced by TUNEL assays. It also provoked an increase of intracellular Ca2+ concentration, activated calpain and decreased superoxide dismutase activity, indicating that an apoptosis-like event occurred; however, autophagy was not detected. Cytopathic activity, phagocytosis, encystment and in vivo virulence were diminished dramatically by pre-incubation of trophozoites with resveratrol, evidencing that resveratrol attenuated the trophozoite virulence in vitro. Interestingly, after the inoculation of virulent trophozoites, animals treated with the drug did not develop or developed very small abscesses. Our findings propose that resveratrol could be an alternative to contend amoebiasis. PMID:26731663

  17. Resveratrol Induces Apoptosis-Like Death and Prevents In Vitro and In Vivo Virulence of Entamoeba histolytica.

    PubMed

    Pais-Morales, Jonnatan; Betanzos, Abigail; García-Rivera, Guillermina; Chávez-Munguía, Bibiana; Shibayama, Mineko; Orozco, Esther

    2016-01-01

    Entamoeba histolytica causes amoebiasis, an infection that kills 100,000 individuals each year. Metronidazole and its derivatives are currently used against this protozoan, but these drugs present adverse effects on human health. Here, we investigated the effect of resveratrol (a natural compound) on E. histolytica trophozoites viability, as well as its influence on the parasite virulence. Trophozoites growth was arrested by 72 μM resveratrol and the IC50 was determined as 220 μM at 48 h. Cells appeared smaller, rounded and in clusters, with debris-containing vacuoles and with abnormally condensed chromatin. Resveratrol triggered reactive oxygen species production. It caused lipid peroxidation and produced phosphatidylserine externalization and DNA fragmentation this latter evidenced by TUNEL assays. It also provoked an increase of intracellular Ca2+ concentration, activated calpain and decreased superoxide dismutase activity, indicating that an apoptosis-like event occurred; however, autophagy was not detected. Cytopathic activity, phagocytosis, encystment and in vivo virulence were diminished dramatically by pre-incubation of trophozoites with resveratrol, evidencing that resveratrol attenuated the trophozoite virulence in vitro. Interestingly, after the inoculation of virulent trophozoites, animals treated with the drug did not develop or developed very small abscesses. Our findings propose that resveratrol could be an alternative to contend amoebiasis.

  18. Vitamin D fails to prevent serum starvation- or staurosporine-induced apoptosis in human and rat osteosarcoma-derived cell lines

    SciTech Connect

    Witasp, Erika; Gustafsson, Ann-Catrin; Cotgreave, Ian; Lind, Monica . E-mail: monica.lind@imm.ki.se; Fadeel, Bengt . E-mail: bengt.fadeel@imm.ki.se

    2005-05-13

    Previous studies have suggested that 1,25(OH){sub 2}D{sub 3}, the active form of vitamin D{sub 3}, may increase the survival of bone-forming osteoblasts through an inhibition of apoptosis. On the other hand, vitamin D{sub 3} has also been shown to trigger apoptosis in human cancer cells, including osteosarcoma-derived cell lines. In the present study, we show that 1,25(OH){sub 2}D{sub 3} induces a time- and dose-dependent loss of cell viability in the rat osteosarcoma cell line, UMR-106, and the human osteosarcoma cell line, TE-85. We were unable, however, to detect nuclear condensation, phosphatidylserine externalization, or other typical signs of apoptosis in this model. Moreover, 1,25(OH){sub 2}D{sub 3} failed to protect against apoptosis induced by serum starvation or incubation with the protein kinase inhibitor, staurosporine. These in vitro findings are thus at variance with several previous reports in the literature and suggest that induction of or protection against apoptosis of bone-derived cells may not be a primary function of vitamin D{sub 3}.

  19. Lichen metabolites prevent UV light and nitric oxide-mediated plasmid DNA damage and induce apoptosis in human melanoma cells.

    PubMed

    Russo, A; Piovano, M; Lombardo, L; Garbarino, J; Cardile, V

    2008-09-26

    In humans both UV-A and UV-B can cause gene mutations and suppress immunity, which leads to skin cancer, including melanoma. Inhibition of reactive oxygen species (ROS) and reactive nitrogen species (RNS) appears particularly promising as ROS and RNS production by both UV-A and UV-B contributes to inflammation, immunosuppression, gene mutation and carcinogenesis. We evaluated the effect of two lichen compounds, sphaerophorin (depside) and pannarin (depsidone) on pBR322 DNA cleavage induced by hydroxyl radicals (()OH), and by nitric oxide (NO), and their superoxide anion (O(2)(-)) scavenging capacity. In addition, we investigated the growth inhibitory activity of these compounds against human melanoma cells (M14 cell line). Sphaerophorin and pannarin showed a protective effect on plasmid DNA and exhibited a superoxide dismutase like effect. The data obtained in cell culture show that these lichen metabolites inhibit the growth of melanoma cells, inducing an apoptotic cell death, demonstrated by the fragmentation of genomic DNA (COMET and TUNEL Assays) and by a significant increase of caspase-3 activity, and correlated, at least in part, to the increase of ROS generation, These results confirm the promising biological properties of sphaerophorin and pannarin and encourage further investigations on their molecular mechanisms.

  20. Activation of TOLLIP by porin prevents TLR2-associated IFN-γ and TNF-α-induced apoptosis of intestinal epithelial cells.

    PubMed

    Mukherjee, Subhadeep; Biswas, Tapas

    2014-12-01

    Interferon (IFN)-γ and tumor necrosis factor (TNF)-α cause chronic inflammation of the intestine leading to progression of inflammatory bowel disease (IBD), which is manifested through rapid apoptosis of the intestinal epithelial cells (iECs). Here, we show inhibition of IFN-γ and TNF-α-induced apoptosis of INT-407 cells by porin, a microbe-associated molecular pattern (MAMP) with affinity for toll-like receptor (TLR)2 and commonly present in Gram-negative bacteria. Proinflammatory cytokines induce apoptosis by activation of caspase 8 that triggers caspase 9 through Bax finally leading to activation of caspase 3, the executioner caspase. Interestingly, while IFN-γ and TNF-α promotes Bax expression, in contrast porin up-regulates anti-apoptotic Bcl-xL resulting in iEC survivability. We show elevated expression of TLR2 is a key requisite for IFN-γ and TNF-α mediated caspase 8 up-regulation that contributes to apoptosis of iECs. Down-regulation of TLR2 expression is central for checking apoptosis which is achieved by elevated level of toll-interacting protein (TOLLIP) in presence of porin. Attempts to limit IBD is in progress with anti-IFN-γ and anti-TNF-α Abs or use of IL-10. Although probiotic bacterial proteins have shown to successfully reduce IFN-γ and TNF-α mediated apoptosis, the exact mechanism of their action has remained elusive. This study identifies the underlying sequential events of transient TLR2 stimulation followed by its blocking in response to the bacterial outer membrane protein, which advocates intervention at TLR-juncture is crucial for controlling IBD.

  1. Thymol and carvacrol prevent cisplatin-induced nephrotoxicity by abrogation of oxidative stress, inflammation, and apoptosis in rats.

    PubMed

    El-Sayed, E M; Abd-Allah, A R; Mansour, A M; El-Arabey, A A

    2015-04-01

    The aim of the present study is to assess the possible protective effects of thymol and carvacrol against cisplatin (CP)-induced nephrotoxicity. A single dose of CP {6 mg/kg, intraperitoneally (i.p.)} injected to male rats revealed significant increases in serum urea, creatinine, and tumor necrosis factor alpha levels. It also increased kidney contents of malondialdehyde and caspase-3 activity with significant reduction in serum albumin, kidney content of reduced glutathione as well as catalase, and superoxide dismutase activity as compared to that of the control group. In contrast, administration of thymol {20 mg/kg, orally (p.o.)} and/or carvacrol (15 mg/kg, p.o.) for 14 days before CP injection and for 7 days after CP administration restored the kidney function and examined oxidative stress parameters. In conclusion, thymol was more effective nephroprotective than carvacrol. Moreover, a combination of thymol and carvacrol had a synergistic nephroprotective effect that might be attributed to antioxidant, anti-inflammatory, and antiapoptotic activities. PMID:25487789

  2. Luteolin Prevents H2O2-Induced Apoptosis in H9C2 Cells through Modulating Akt-P53/Mdm2 Signaling Pathway

    PubMed Central

    Li, Chun; Wang, Qiyan; Lu, Linghui; Zhang, Qian

    2016-01-01

    Introduction. Luteolin, a falconoid compound in many Chinese herbs and formula, plays important roles in cardiovascular diseases. The underlying mechanism of luteolin remains to be further elaborated. Methods. A model of hydrogen peroxide- (H2O2-) induced H9C2 cells apoptosis was established. Cell viabilities were examined with an MTT assay. 2′,7′-Dichlorofluorescin diacetate (DCFH-DA) and flow cytometry were used to detect ROS level and apoptosis rate, respectively. The expressions of signaling proteins related to apoptosis were analyzed by western blot and mRNA levels were detected by real-time polymerase chain reaction (PCR). Quercetin was applied as positive drug. Results. Incubation with various concentrations of H2O2 (0, 50, 100, and 200 μM) for 1 h caused dose-dependent loss of cell viability and 100 μM H2O2 reduced the cell viability to approximately 50%. Treatments with luteolin and quercetin protected cells from H2O2-induced cytotoxicity and reduced cellular ROS level and apoptosis rate. Moreover, luteolin could downregulate the expressions of Bax, caspase-8, cleaved-caspase-3, and p53 in apoptotic signaling pathway. Further study showed that the expressions of Akt, Bcl-2, and Mdm2 were upregulated by luteolin. Conclusion. Luteolin protects H9C2 cells from H2O2-induced apoptosis. The protective and antiapoptotic effects of luteolin could be mediated by regulating the Akt-P53/Mdm2 apoptotic pathway. PMID:27525270

  3. iRAGE as a novel carboxymethylated peptide that prevents advanced glycation end product-induced apoptosis and endoplasmic reticulum stress in vascular smooth muscle cells.

    PubMed

    Maltais, Jean-Sébastien; Simard, Elie; Froehlich, Ulrike; Denault, Jean-Bernard; Gendron, Louis; Grandbois, Michel

    2016-02-01

    Advanced glycation end-products (AGE) and the receptor for AGE (RAGE) have been linked to numerous diabetic vascular complications. RAGE activation promotes a self-sustaining state of chronic inflammation and has been shown to induce apoptosis in various cell types. Although previous studies in vascular smooth muscle cells (VSMC) showed that RAGE activation increases vascular calcification and interferes with their contractile phenotype, little is known on the potential of RAGE to induce apoptosis in VSMC. Using a combination of apoptotic assays, we showed that RAGE stimulation with its ligand CML-HSA promotes apoptosis of VSMC. The formation of stress granules and the increase in the level of the associated protein HuR point toward RAGE-dependent endoplasmic reticulum (ER) stress, which is proposed as a key contributor of RAGE-induced apoptosis in VSMC as it has been shown to promote cell death via numerous mechanisms, including up-regulation of caspase-9. Chronic NF-κB activation and modulation of Bcl-2 homologs are also suspected to contribute to RAGE-dependent apoptosis in VSMC. With the goal of reducing RAGE signaling and its detrimental impact on VSMC, we designed a RAGE antagonist (iRAGE) derived from the primary amino acid sequence of HSA. The resulting CML peptide was selected for the high glycation frequency of the primary sequence in the native protein in vivo. Pretreatment with iRAGE blocked 69.6% of the increase in NF-κB signaling caused by RAGE activation with CML-HSA after 48h. Preincubation with iRAGE was successful in reducing RAGE-induced apoptosis, as seen through enhanced cell survival by SPR and reduced PARP cleavage. Activation of executioner caspases was 63.5% lower in cells treated with iRAGE before stimulation with CML-HSA. To our knowledge, iRAGE is the first antagonist shown to block AGE-RAGE interaction and we propose the molecule as an initial candidate for drug discovery.

  4. Intracoronary Levosimendan during Ischemia Prevents Myocardial Apoptosis

    PubMed Central

    Malmberg, Markus; Vähäsilta, Tommi; Saraste, Antti; Koskenvuo, Juha W.; Pärkkä, Jussi P.; Leino, Kari; Laitio, Timo; Stark, Christoffer; Heikkilä, Aira; Saukko, Pekka; Savunen, Timo

    2012-01-01

    Background: Levosimendan is a calcium sensitizer that has been shown to prevent myocardial contractile depression in patients post cardiac surgery. This drug exhibits an anti-apoptotic property; however, the underlying mechanism remains elusive. In this report, we characterized the myocardial protective of levosimendan in preventing cardiomyocyte apoptosis and post-operative stunning in an experimental ischemia–reperfusion model. Methods: Three groups of pigs (n = 8 per group) were subjected to 40 min of global, cardioplegic ischemia followed by 240 min of reperfusion. Levosimendan (65 μg/kg body weight) was given to pigs by intravenous infusion (L-IV) before ischemia or intracoronary administration during ischemia (L-IC). The Control group did not receive any levosimendan. Echocardiography was used to monitor cardiac function in all groups. Apoptosis levels were assessed from the left ventricle using the terminal transferase mediated dUTP nick end labeling (TUNEL) assay and immunocytochemical detection of Caspase-3. Results: Pigs after ischemia–reperfusion had a much higher TUNEL%, suggesting that our treatment protocol was effective. Levels of apoptosis were significantly increased in Control pigs that did not receive any levosimendan (0.062 ± 0.044%) relative to those received levosimendan either before (0.02 ± 0.017%, p = 0.03) or during (0.02 ± 0.017%, p = 0.03) the ischemia phase. Longitudinal left ventricular contraction in pigs that received levosimendan before ischemia (0.75 ± 0.12 mm) was significantly higher than those received levosimendan during ischemia (0.53 ± 0.11 mm, p = 0.003) or Control pigs (0.54 ± 0.11 mm, p = 0.01). Conclusion: Our results suggested that pigs received levosimendan displayed a markedly improved cell survival post I–R. The effect on cardiac contractility was only significant in our perfusion heart model when levosimendan was delivered intravenously before

  5. 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.

  6. 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.

  7. Prevention of Trauma and Hemorrhagic Shock-Mediated Liver Apoptosis by Activation of Stat3α

    PubMed Central

    Moran, Ana; Akcan Arikan, Ayse; Mastrangelo, Mary-Ann A.; Wu, Yong; Yu, Bi; Poli, Valeria; Tweardy, David J.

    2008-01-01

    Trauma is a major cause of mortality in the United States. Death among those surviving the initial insult is caused by multiple organ failure (MOF) with the liver among the organs most frequently affected. We previously demonstrated in rodents that trauma complicated by hemorrhagic shock (trauma/HS) results in liver injury that can be prevented by IL-6 administration at the start of resuscitation; however, the contribution of the severity of HS to the extent of liver injury, whether or not resuscitation is required and the mechanism for the IL-6 protective effect have not been reported. In the experiments reported here, we demonstrated that the extent of liver apoptosis induced by trauma/HS depends on the duration of hypotension and requires resuscitation. We established that IL-6 administration at the start of resuscitation is capable of completely reversing liver apoptosis and is associated with increased Stat3 activation. Microarray analysis of the livers showed that the main effect of IL-6 was to normalize the trauma/HS-induced apoptosis transcriptome. Pharmacological inhibition of Stat3 activity within the liver blocked the ability of IL-6 to prevent liver apoptosis and to normalize the trauma/HS- induced liver apoptosis transcriptome. Genetic deletion of a Stat3β, a naturally occurring, dominant-negative isoform of the Stat3, attenuated trauma/HS-induced liver apoptosis, confirming a role for Stat3, especially Stat3α, in preventing trauma/HS-mediated liver apoptosis. Thus, trauma/HS-induced liver apoptosis depends on the duration of hypotension and requires resuscitation. IL-6 administration at the start of resuscitation reverses HS-induced liver apoptosis, through activation of Stat3α, which normalizes the trauma/HS-induced liver apoptosis transcriptome. PMID:18997875

  8. Spirafolide from bay leaf (Laurus nobilis) prevents dopamine-induced apoptosis by decreasing reactive oxygen species production in human neuroblastoma SH-SY5Y cells.

    PubMed

    Ham, Ahrom; Kim, Bora; Koo, Uk; Nam, Kung-Woo; Lee, Sung-Jin; Kim, Kyeong Ho; Shin, Jongheon; Mar, Woongchon

    2010-12-01

    Reactive oxygen species (ROS) are important mediators in many neurodegenerative diseases including Alzheimer's disease and Parkinson's disease. This study tested the neuroprotective effects of spirafolide, a compound purified from the leaves of Laurus nobilis L. (Lauraceae), against dopamine (DA)-induced apoptosis in human neuroblastoma SH-SY5Y cells. Following a 24-h exposure of cells to DA (final conc., 0.6 mM), we observed a marked increase in apoptosis, increased generation of ROS and decreased cell viability. Pretreatment of the cells for 24 h with spirafolide (0.4, 2, and 10 μM) before exposure to DA notably increased cell survival (p < 0.01) and lowered intracellular ROS levels (p < 0.01). These results indicate that spirafolide has neuroprotective effects against DA toxicity. These effects may contribute to the treatment of neurodegenerative diseases.

  9. Gonadotropin-releasing hormone agonist selectively augments thymopoiesis and prevents cell apoptosis in LPS induced thymic atrophy model independent of gonadal steroids.

    PubMed

    Ullewar, Meenal P; Umathe, Sudhir N

    2014-11-01

    Lipopolysaccharide (LPS) causes acute thymic atrophy, a phenomenon that has been linked to immune dysfunction and poor survival during sepsis. The systemic response to LPS involves a rise in glucocorticoids and proinflammatory cytokines which contribute greatly to thymic involution and apoptosis. Gonadotropin-releasing hormone (GnRH) analog exerts thymopoietic regulatory effects and possesses immunostimulant properties. We determined whether leuprolide, a GnRH analog can be useful in LPS induced thymic involution and apoptosis. Mice injected with 100 μg of LPS intraperitoneally led to involution of thymus, to decrease of CD4(+)8(+) thymocyte subset, and to fragmentation of thymic DNA. Leuprolide (100 μg/mouse, s.c.) pretreatment significantly attenuated LPS induced thymic atrophy, and also reduced LPS induced systemic rise in corticosterone levels. The observed effect of leuprolide remained unaffected in castrated and ovariectomized mice. Collectively, leuprolide has protective action independent of gonadal steroids, which was mediated by blunting of the systemic corticosteroid response in LPS induced thymic atrophy model.

  10. Synergistic anti-tumor actions of luteolin and silibinin prevented cell migration and invasion and induced apoptosis in glioblastoma SNB19 cells and glioblastoma stem cells.

    PubMed

    Chakrabarti, Mrinmay; Ray, Swapan K

    2015-12-10

    Glioblastoma is the most lethal brain tumor. Failure of conventional chemotherapies prompted the search for natural compounds for treatment of glioblastoma. Plant-derived flavonoids could be alternative medicine for inhibiting not only glioblastoma cells but also glioblastoma stem cells (GSC). Two plant-derived flavonoids are luteolin (LUT) and silibinin (SIL). We investigated anti-tumor mechanisms of LUT and SIL in different human glioblastoma cells and GSC and found significant synergistic inhibition of human glioblastoma LN18 and SNB19 cells and GSC following treatment with combination of 20µM LUT and 50µM SIL. Combination of 20µM LUT and 50µM SIL was more effective than a conventional chemotherapeutic agent (BCNU or TMZ). We continued our studies with SNB19 cells and GSC and found dramatic inhibition of cell migration from spheroids and also cell invasion through matrigel following treatment with combination of LUT and SIL. This combination was highly effective to block angiogenesis and survival pathways leading to induction of apoptosis. Inhibition of PKCα, XIAP, and iNOS ultimately caused induction of extrinsic and intrinsic pathways of apoptosis. Collectively, synergistic efficacy of LUT and SIL could be a promising therapy to inhibit cell migration and invasion and induce apoptosis in different glioblastoma cells including GSC.

  11. A novel form of constitutively active farnesylated Akt1 prevents mammary epithelial cells from anoikis and suppresses chemotherapy-induced apoptosis.

    PubMed

    Schmidt, M; Hövelmann, S; Beckers, T L

    2002-10-01

    Protein kinase B/Akt has been described as a central mediator of anti-apoptotic signals transduced by the PI3 kinase. Although the role of Akt in the suppression of apoptosis is well elucidated, a potential function of Akt in tumorigenesis and chemoresistance is less intensively documented. In this study, we describe the construction of a novel form of constitutively active Akt1, which relies on the deletion of its pleckstrin homology domain and the insertion of a C-terminal farnesylation sequence. Stable cell lines were generated with MCF10A mammary epithelial cells and A549 human NSCLC cells expressing constitutively active Akt1. Enigneered MCF10A cells were rendered resistant towards apoptosis resulting from loss of cellular substrate attachment (anoikis). We investigated the chemosensitivity of A549 cells expressing farnesylated Akt vs control cells. A profoundly decreased sensitivity towards Mitoxantrone and cisplatin was observed in cells expressing farnesylated Akt. No significant difference in sensitivity however was observed upon treatment with cell cycle specific chemotherapeutic agents like paclitaxel. Our data suggest, that Akt is a central mediator in the suppression of anoikis and modulation of chemotherapy-induced apoptosis. Therefore it represents a promising target for small molecule inhibitors to shift the apoptotic threshold in cancer cells after treatment with standard chemotherapy.

  12. 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

  13. 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

  14. 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.

  15. 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

  16. Hydrogen sulfide prevents OGD/R-induced apoptosis by suppressing the phosphorylation of p38 and secretion of IL-6 in PC12 cells.

    PubMed

    Li, Chong; Liu, Yue; Tang, Peng; Liu, Peng; Hou, Chen; Zhang, Xin; Chen, Li; Zhang, Lina; Gu, Chaochao

    2016-03-01

    Hydrogen sulfide (H2S), a well-known endogenous mediator, has been shown to exert protective effects against neuronal damage caused by brain ischemia, but the mechanism of its action remains unclear. We have reported the neuroprotective properties of H2S against oxygen-glucose deprivation/reoxygenation (OGD/R)-induced injury by inhibiting the phosphorylation of p38. The present study evaluates the effect of H2S on OGD/R-induced cell injury or apoptosis and the mechanisms for its action in PC12 cells. Pretreatment of PC12 cells with exogenous sodium hydrosulfide (NaHS) (a H2S donor, 100 or 300 µM) for 12 h before exposure to OGD/R markedly attenuated p38 phosphorylation. Activation of p38 MAPK by transfection of activated p38α, but not p38β, reversed the protective effect of NaHS, as measured by enzyme-linked immunosorbent assay analysis. Importantly, SB203580 (a p38 MAPK inhibitor) also reversed the protective effects of p38α-activated p38 MAPK. Interleukin-6 secretion after OGD/R decreased significantly with NaHS compared with without NaHS. Taken together, we show that the p38 pathway contributes toward OGD/R-induced cell death and p38α plays a key role in OGD/R-induced interleukin-6 secretion.

  17. [Protein kinase C activation induces platelet apoptosis].

    PubMed

    Zhao, Li-Li; Chen, Meng-Xing; Zhang, Ming-Yi; Dai, Ke-Sheng

    2013-10-01

    Platelet apoptosis elucidated by either physical or chemical compound or platelet storage occurs wildly, which might play important roles in controlling the numbers and functions of circulated platelets, or in the development of some platelet-related diseases. However, up to now, a little is known about the regulatory mechanisms of platelet apoptosis. Protein kinase C (PKC) is highly expressed in platelets and plays central roles in regulating platelet functions. Although there is evidence indicating that PKC is involved in the regulation of apoptosis of nucleated cells, it is still unclear whether PKC plays a role in platelet apoptosis. The aim of this study was to investigate the role of PKC in platelet apoptosis. The effects of PKC on mitochondrial membrane potential (ΔΨm), phosphatidylserine (PS) exposure, and caspase-3 activation of platelets were analyzed by flow cytometry and Western blot. The results showed that the ΔΨm depolarization in platelets was induced by PKC activator in time-dependent manner, and the caspase-3 activation in platelets was induced by PKC in concentration-dependent manner. However, the platelets incubated with PKC inhibitor did not results in ΔΨm depolarization and PS exposure. It is concluded that the PKC activation induces platelet apoptosis through influencing the mitochondrial functions and activating caspase 3. The finds suggest a novel mechanism for PKC in regulating platelet numbers and functions, which has important pathophysiological implications for thrombosis and hemostasis.

  18. 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

  19. 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

  20. 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.

  1. Umbelliprenin Induces Apoptosis in CLL Cell Lines.

    PubMed

    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.

  2. 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

  3. Drosophila grim induces apoptosis in mammalian cells.

    PubMed Central

    Clavería, C; Albar, J P; Serrano, A; Buesa, J M; Barbero, J L; Martínez-A, C; Torres, M

    1998-01-01

    Genetic studies have shown that grim is a central genetic switch of programmed cell death in Drosophila; however, homologous genes have not been described in other species, nor has its mechanism of action been defined. We show here that grim expression induces apoptosis in mouse fibroblasts. Cell death induced by grim in mammalian cells involves membrane blebbing, cytoplasmic loss and nuclear DNA fragmentation. Grim-induced apoptosis is blocked by both natural and synthetic caspase inhibitors. We found that grim itself shows caspase-dependent proteolytic processing of its C-terminus in vitro. Grim-induced death is antagonized by bcl-2 in a dose-dependent manner, and neither Fas signalling nor p53 are required for grim pro-apoptotic activity. Grim protein localizes both in the cytosol and in the mitochondria of mouse fibroblasts, the latter location becoming predominant as apoptosis progresses. These results show that Drosophila grim induces death in mammalian cells by specifically acting on mitochondrial apoptotic pathways executed by endogenous caspases. These findings advance our knowledge of the mechanism by which grim induces apoptosis and show the conservation through evolution of this crucial programmed cell death pathway. PMID:9857177

  4. (+)-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

  5. Molecular mechanisms of asbestos-induced lung epithelial cell apoptosis.

    PubMed

    Liu, Gang; Beri, Rohinee; Mueller, Amanda; Kamp, David W

    2010-11-01

    Asbestos causes pulmonary fibrosis (asbestosis) and malignancies (bronchogenic lung cancer and mesothelioma) by mechanisms that are not fully elucidated. Accumulating evidence show that alveolar epithelial cell (AEC) apoptosis is a crucial initiating and perpetuating event in the development of pulmonary fibrosis following exposure to a wide variety of noxious stimuli, including asbestos. We review the important molecular mechanisms underlying asbestos-induced AEC apoptosis. Specifically, we focus on the role of asbestos in augmenting AEC apoptosis by the mitochondria- and p53-regulated death pathways that result from the production of iron-derived reactive oxygen species (ROS) and DNA damage. We summarize emerging evidence implicating the endoplasmic reticulum (ER) stress response in AEC apoptosis in patients with idiopathic pulmonary fibrosis (IPF), a disease with similarities to asbestosis. Finally, we discuss a recent finding that a mitochondrial oxidative DNA repair enzyme (8-oxoguanine DNA glycosylase; Ogg1) acts as a mitochondrial aconitase chaperone protein to prevent oxidant (asbestos and H(2)O(2))-induced AEC mitochondrial dysfunction and intrinsic apoptosis. The coupling of mitochondrial Ogg1 to mitochondrial aconitase is a novel mechanism linking metabolism to mitochondrial DNA that may be important in the pathophysiologic events resulting in oxidant-induced toxicity as seen in tumors, aging, and respiratory disorders (e.g. asbestosis, IPF). Collectively, these studies are illuminating the molecular basis of AEC apoptosis following asbestos exposure that may prove useful for developing novel therapeutic strategies. Importantly, the asbestos paradigm is elucidating pathophysiologic insights into other more common pulmonary diseases, such as IPF and lung cancer, for which better therapy is required. PMID:20380827

  6. Acetaminophen prevents oxidative burst and delays apoptosis in human neutrophils.

    PubMed

    Freitas, Marisa; Costa, Vera M; Ribeiro, Daniela; Couto, Diana; Porto, Graça; Carvalho, Félix; Fernandes, Eduarda

    2013-05-23

    Acetaminophen is a frequently prescribed over-the-counter drug to reduce fever and pain in the event of inflammatory process. As neutrophils are relevant cells in inflammatory processes, the putative interaction of acetaminophen with these cells, if present, would be of paramount importance. The present study was undertaken to evaluate the effect of acetaminophen in human neutrophils' oxidative burst and lifespan in vitro. The obtained results demonstrate that acetaminophen efficiently modulates neutrophils' oxidative burst in phorbol myristate acetate-activated neutrophils, in a concentration-dependent manner, at in vivo relevant concentrations. It was clearly demonstrated that acetaminophen is a strong scavenger of HOCl and H2O2, which probably contributed to the effect observed in neutrophils. Acetaminophen also induced the depletion of glutathione in stimulated neutrophils, suggesting its transformation into a reactive intermediate. Obtained results further revealed that acetaminophen affects programmed cell death of human neutrophils, resulting in a delay of previously stimulated neutrophils-mediated apoptosis. Overall, our data suggested that acetaminophen has considerable potential to be included in anti-inflammatory therapeutic strategies, by preventing biological damage induced by an excessive production of reactive species generated in activated neutrophils and by extending the lifespan of neutrophils, favoring the elimination of pathogens, thus contributing to tissue healing and resolution of inflammation. PMID:23518321

  7. A New Fungal Diterpene Induces VDAC1-dependent Apoptosis in Bax/Bak-deficient Cells.

    PubMed

    Huang, Li; Han, Junjie; Ben-Hail, Danya; He, Luwei; Li, Baowei; Chen, Ziheng; Wang, Yueying; Yang, Yanlei; Liu, Lei; Zhu, Yushan; Shoshan-Barmatz, Varda; Liu, Hongwei; Chen, Quan

    2015-09-25

    The pro-apoptotic Bax and Bak proteins are considered central to apoptosis, yet apoptosis occurs in their absence. Here, we asked whether the mitochondrial protein VDAC1 mediates apoptosis independently of Bax/Bak. Upon screening a fungal secondary metabolite library for compounds inducing apoptosis in Bax/Bak-deficient mouse embryonic fibroblasts, we identified cyathin-R, a new cyathane diterpenoid compound able to activate apoptosis in the absence of Bax/Bak via promotion of the VDAC1 oligomerization that mediates cytochrome c release. Diphenylamine-2-carboxilic acid, an inhibitor of VDAC1 conductance and oligomerization, inhibited cyathin-R-induced VDAC1 oligomerization and apoptosis. Similarly, Bcl-2 overexpression conferred resistance to cyathin-R-induced apoptosis and VDAC1 oligomerization. Silencing of VDAC1 expression prevented cyathin-R-induced apoptosis. Finally, cyathin-R effectively attenuated tumor growth and induced apoptosis in Bax/Bak-deficient cells implanted into a xenograft mouse model. Hence, this study identified a new compound promoting VDAC1-dependent apoptosis as a potential therapeutic option for cancerous cells lacking or presenting inactivated Bax/Bak.

  8. A New Fungal Diterpene Induces VDAC1-dependent Apoptosis in Bax/Bak-deficient Cells*

    PubMed Central

    Huang, Li; Han, Junjie; Ben-Hail, Danya; He, Luwei; Li, Baowei; Chen, Ziheng; Wang, Yueying; Yang, Yanlei; Liu, Lei; Zhu, Yushan; Shoshan-Barmatz, Varda; Liu, Hongwei; Chen, Quan

    2015-01-01

    The pro-apoptotic Bax and Bak proteins are considered central to apoptosis, yet apoptosis occurs in their absence. Here, we asked whether the mitochondrial protein VDAC1 mediates apoptosis independently of Bax/Bak. Upon screening a fungal secondary metabolite library for compounds inducing apoptosis in Bax/Bak-deficient mouse embryonic fibroblasts, we identified cyathin-R, a new cyathane diterpenoid compound able to activate apoptosis in the absence of Bax/Bak via promotion of the VDAC1 oligomerization that mediates cytochrome c release. Diphenylamine-2-carboxilic acid, an inhibitor of VDAC1 conductance and oligomerization, inhibited cyathin-R-induced VDAC1 oligomerization and apoptosis. Similarly, Bcl-2 overexpression conferred resistance to cyathin-R-induced apoptosis and VDAC1 oligomerization. Silencing of VDAC1 expression prevented cyathin-R-induced apoptosis. Finally, cyathin-R effectively attenuated tumor growth and induced apoptosis in Bax/Bak-deficient cells implanted into a xenograft mouse model. Hence, this study identified a new compound promoting VDAC1-dependent apoptosis as a potential therapeutic option for cancerous cells lacking or presenting inactivated Bax/Bak. PMID:26253170

  9. Activation of the IFN-inducible enzyme RNase L causes apoptosis of animal cells.

    PubMed

    Díaz-Guerra, M; Rivas, C; Esteban, M

    1997-09-29

    The interferon (IFN)-induced enzyme RNase L produced by a recombinant vaccinia virus (VV) causes death of mammalian cells with morphological and biochemical characteristics of apoptosis. Coexpression of 2-5A-synthetase enhances apoptosis induced by RNase L Activation of endogenous RNase L by infection with a VV ts mutant (ts22) or with wild-type virus in the presence of the antipoxvirus drug isatin-beta-thiosemicarbazone, a treatment known to significantly increase the amount of double-stranded RNA late during infection, also causes pronounced apoptosis of infected cells. The effects observed with recombinant virus-derived RNase L or with the endogenous enzyme are specific, since apoptosis also occurs in cells derived from mice lacking the IFN-induced protein kinase (PKR). The apoptosis antagonist Bcl-2 prevents induction of cell death by RNase L activation. Apoptosis of mammalian cells by RNase L activation could be a mechanism mediating anticellular actions of IFN.

  10. Chronic Treatment with a Water-Soluble Extract from the Culture Medium of Ganoderma lucidum Mycelia Prevents Apoptosis and Necroptosis in Hypoxia/Ischemia-Induced Injury of Type 2 Diabetic Mouse Brain.

    PubMed

    Xuan, Meiyan; Okazaki, Mari; Iwata, Naohiro; Asano, Satoshi; Kamiuchi, Shinya; Matsuzaki, Hirokazu; Sakamoto, Takeshi; Miyano, Yoshiyuki; Iizuka, Hiroshi; Hibino, Yasuhide

    2015-01-01

    Type 2 diabetes mellitus has been known to increase systemic oxidative stress by chronic hyperglycemia and visceral obesity and aggravate cerebral ischemic injury. On the basis of our previous study regarding a water-soluble extract from the culture medium of Ganoderma lucidum mycelia (designed as MAK), which exerts antioxidative and neuroprotective effects, the present study was conducted to evaluate the preventive effects of MAK on apoptosis and necroptosis (a programmed necrosis) induced by hypoxia/ischemia (H/I) in type 2 diabetic KKAy mice. H/I was induced by a combination of unilateral common carotid artery ligation with hypoxia (8% O2 for 20 min) and subsequent reoxygenation. Pretreatment with MAK (1 g/kg, p.o.) for a week significantly reduced H/I-induced neurological deficits and brain infarction volume assessed at 24 h of reoxygenation. Histochemical analysis showed that MAK significantly suppressed superoxide production, neuronal cell death, and vacuolation in the ischemic penumbra, which was accompanied by a decrease in the numbers of TUNEL- or cleaved caspase-3-positive cells. Furthermore, MAK decreased the expression of receptor-interacting protein kinase 3 mRNA and protein, a key molecule for necroptosis. These results suggest that MAK confers resistance to apoptotic and necroptotic cell death and relieves H/I-induced cerebral ischemic injury in type 2 diabetic mice.

  11. Safrole oxide inhibits angiogenesis by inducing apoptosis.

    PubMed

    Zhao, Jing; Miao, Junying; Zhao, Baoxiang; Zhang, Shangli; Yin, Deling

    2005-06-01

    Our previous studies indicate that 3, 4-(methylenedioxy)-1-(2', 3'-epoxypropyl)-benzene (safrole oxide), a newly synthesized compound, induces apoptosis in vascular endothelial cells (VECs) and A549 lung cancer cells. To our knowledge, the inhibition of angiogenesis by safrole oxide has not been reported yet. We report here that cultured rat aorta treated with safrole oxide exhibited a significant microvessel reduction as determined by counting the number of microvessels in a phase contrast microscope. There were more microvessels formed in the presence of A549 lung cancer cells in rat aorta model, while a dramatic inhibition of angiogenesis was obtained by adding 220-450 micromol l(-1) of safrole oxide to the growth medium (P<.01). The culture of rat aorta treated with safrole oxide produced only some abortive endothelial cells but not microvessels. Furthermore, safrole oxide induced antiangiogenic effect in the chorioallantoic membranes (CAM) as a dose dependent manner. Eggs treated with 2-11 micromol 100 microl(-1) per egg of the safrole oxide for 48 h exhibited a significant reduction in blood vessel area of the CAM, a process likely mediated by apoptosis as demonstrated by DNA fragmentation. Our results suggest that safrole oxide has antiangiogenic activity and this effect might occur by induction of cellular apoptosis.

  12. Zinc Induces Apoptosis of Human Melanoma Cells, Increasing Reactive Oxygen Species, p53 and FAS Ligand.

    PubMed

    Provinciali, Mauro; Pierpaoli, Elisa; Bartozzi, Beatrice; Bernardini, Giovanni

    2015-10-01

    The aim of this study was to examine the in vitro effect of zinc on the apoptosis of human melanoma cells, by studying the zinc-dependent modulation of intracellular levels of reactive oxygen species (ROS) and of p53 and FAS ligand proteins. We showed that zinc concentrations ranging from 33.7 μM to 75 μM Zn(2+) induced apoptosis in the human melanoma cell line WM 266-4. This apoptosis was associated with an increased production of intracellular ROS, and of p53 and FAS ligand protein. Treatment of tumor cells with the antioxidant N-acetylcysteine was able to prevent Zn(2+)-induced apoptosis, as well as the increase of p53 and FAS ligand protein induced by zinc. Zinc induces apoptosis in melanoma cells by increasing ROS and this effect may be mediated by the ROS-dependent induction of p53 and FAS/FAS ligand.

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

    PubMed Central

    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

  14. 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

  15. Toll-like Receptor 9 Can be Activated by Endogenous Mitochondrial DNA to Induce Podocyte Apoptosis

    PubMed Central

    Bao, Wenduona; Xia, Hong; Liang, Yaojun; Ye, Yuting; Lu, Yuqiu; Xu, Xiaodong; Duan, Aiping; He, Jing; Chen, Zhaohong; Wu, Yan; Wang, Xia; Zheng, Chunxia; Liu, Zhihong; Shi, Shaolin

    2016-01-01

    Toll-like receptor 9 (TLR9) senses bacterial DNA characteristic of unmethylated CpG motifs to induce innate immune response. TLR9 is de novo expressed in podocytes of some patients with glomerular diseases, but its role in podocyte injury remains undetermined. Since TLR9 activates p38 MAPK and NFkB that are known to mediate podocyte apoptosis, we hypothesized that TLR9 induces podocyte apoptosis in glomerular diseases. We treated immortalized podocytes with puromycin aminonucleosides (PAN) and observed podocyte apoptosis, accompanied by TLR9 upregulation. Prevention of TLR9 upregulation by siRNA significantly attenuated NFκB p65 or p38 activity and apoptosis, demonstrating that TLR9 mediates podocyte apoptosis. We next showed that endogenous mitochondrial DNA (mtDNA), whose CpG motifs are also unmethylated, is the ligand for TLR9, because PAN induced mtDNA accumulation in endolysosomes where TLR9 is localized, overexpression of endolysosomal DNase 2 attenuated PAN-induced p38 or p65 activity and podocyte apoptosis, and DNase 2 silencing was sufficient to activate p38 or p65 and induce apoptosis. In PAN-treated rats, TLR9 was upregulated in the podocytes, accompanied by increase of apoptosis markers. Thus, de novo expressed TLR9 may utilize endogenous mtDNA as the ligand to facilitate podocyte apoptosis, a novel mechanism underlying podocyte injury in glomerular diseases. PMID:26934958

  16. Sphingosine-induced apoptosis is dependent on lysosomal proteases.

    PubMed Central

    Kågedal, K; Zhao, M; Svensson, I; Brunk, U T

    2001-01-01

    We propose a new mechanism for sphingosine-induced apoptosis, involving relocation of lysosomal hydrolases to the cytosol. Owing to its lysosomotropic properties, sphingosine, which is also a detergent, especially when protonated, accumulates by proton trapping within the acidic vacuolar apparatus, where most of its action as a detergent would be exerted. When sphingosine was added in low-to-moderate concentrations to Jurkat and J774 cells, partial lysosomal rupture occurred dose-dependently, starting within a few minutes. This phenomenon preceded caspase activation, as well as changes of mitochondrial membrane potential. High sphingosine doses rapidly caused extensive lysosomal rupture and ensuing necrosis, without antecedent apoptosis or caspase activation. The sphingosine effect was prevented by pre-treatment with another, non-toxic, lysosomotropic base, ammonium chloride, at 10 mM. The lysosomal protease inhibitors, pepstatin A and epoxysuccinyl-L-leucylamido-3-methyl-butane ethyl ester ('E-64d'), inhibited markedly sphingosine-induced caspase activity to almost the same degree as the general caspase inhibitor benzyloxycarbonyl-Val-Ala-DL-Asp-fluoromethylketone ('Z-VAD-FMK'), although they did not by themselves inhibit caspases. We conclude that cathepsin D and one or more cysteine proteases, such as cathepsins B or L, are important mediators of sphingosine-induced apoptosis, working upstream of the caspase cascade and mitochondrial membrane-potential changes. PMID:11583579

  17. Akt inhibition improves irinotecan treatment and prevents cell emergence by switching the senescence response to apoptosis

    PubMed Central

    Vétillard, Alexandra; Jonchère, Barbara; Moreau, Marie; Toutain, Bertrand; Henry, Cécile; Fontanel, Simon; Bernard, Anne-Charlotte; Campone, Mario; Guette, Catherine; Coqueret, Olivier

    2015-01-01

    Activated in response to chemotherapy, senescence is a tumor suppressive mechanism that induces a permanent loss of proliferation. However, in response to treatment, it is not really known how cells can escape senescence and how irreversible or incomplete this pathway is. We have recently described that cells that escape senescence are more transformed than non-treated parental cells, they resist anoikis and rely on Mcl-1. In this study, we further characterize this emergence in response to irinotecan, a first line treatment used in colorectal cancer. Our results indicate that Akt was activated as a feedback pathway during the early step of senescence. The inhibition of the kinase prevented cell emergence and improved treatment efficacy, both in vitro and in vivo. This improvement was correlated with senescence inhibition, p21waf1 downregulation and a concomitant activation of apoptosis due to Noxa upregulation and Mcl-1 inactivation. The inactivation of Noxa prevented apoptosis and increased the number of emergent cells. Using either RNA interference or p21waf1-deficient cells, we further confirmed that an intact p53-p21-senescence pathway favored cell emergence and that its downregulation improved treatment efficacy through apoptosis induction. Therefore, although senescence is an efficient suppressive mechanism, it also generates more aggressive cells as a consequence of apoptosis inhibition. We therefore propose that senescence-inducing therapies should be used sequentially with drugs favoring cell death such as Akt inhibitors. This should reduce cell emergence and tumor relapse through a combined induction of senescence and apoptosis. PMID:26485768

  18. 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.

  19. Sodium butyrate induces apoptosis in human colonic tumour cell lines in a p53-independent pathway: implications for the possible role of dietary fibre in the prevention of large-bowel cancer.

    PubMed

    Hague, A; Manning, A M; Hanlon, K A; Huschtscha, L I; Hart, D; Paraskeva, C

    1993-09-30

    The purpose of this study was to determine whether cultured colonic adenoma and carcinoma cells undergo apoptosis (programmed cell death) in vitro and whether specific growth and dietary factors, thought to be involved in the control of growth and differentiation of human colonic cells, could induce cell death through apoptosis. In cell lines originating from 6 colorectal adenomas and 7 carcinomas, spontaneous apoptosis was observed. Sodium butyrate, a naturally occurring fatty acid, is present in the human large bowel in millimolar amounts as a result of bacterial fermentation of dietary fibre. Sodium butyrate, at physiological concentrations, induced apoptosis in 2 adenoma cell lines, RG/C2 and AA/Cl, and in the carcinoma cell line PC/JW/FI. In contrast, transforming growth factor beta 1, which is thought to have an important role in the control of growth in colonic epithelium, did not induce apoptosis. Neither RG/C2 nor PC/JW/FI contain wild-type p53, therefore this tumour-suppressor gene is not required to mediate signals for the induction of apoptosis in colonic tumour cells. Our studies report the induction of apoptosis in colonic tumour cells by the naturally occurring fatty acid sodium butyrate. Since sodium butyrate is produced by bacterial fermentation of dietary fibre, the observation that this fatty acid can induce apoptosis could, in part, explain why a high-fibre diet appears to be protective against colon cancer. Escape from the induction of programmed cell death may be an important event in colorectal carcinogenesis.

  20. Protective effect of trifluoperazine on hydrogen peroxide-induced apoptosis in PC12 cells.

    PubMed

    Liu, Shichang; Han, Yangguang; Zhang, Tao; Yang, Zhuo

    2011-02-01

    This study investigated effects of trifluoperazine (TFP) against the cytotoxicity induced by H₂O₂ in PC12 cells and the mechanisms thereof. Different concentrations of H₂O₂ (100-500 μM) induced a significant decrease in cell viability accompanied by increased oxidative stress and cell apoptosis. Pretreatment with TFP inhibited H₂O₂-induced cell viability loss. The flow cytometric assay showed that TFP can inhibit intracellular reactive oxygen species (ROS) generation and reduce the cell apoptosis. The electrophysiological recordings indicated that when treated with H₂O₂, the calcium current was significantly increased. Pretreatment with TFP increased mitochondrial membrane potential (MMP) in cells of oxidative injury. These results suggested that TFP can reduce apoptosis by inhibiting ROS generation and preventing loss of MMP in cells. Meanwhile, the protective effect of TFP on the cell apoptosis may be related to the calcium overload. TFP may inhibit the calcium overload process to achieve the protection against apoptosis.

  1. Podocyte apoptosis is prevented by blocking the Toll-like receptor pathway

    PubMed Central

    Saurus, P; Kuusela, S; Lehtonen, E; Hyvönen, M E; Ristola, M; Fogarty, C L; Tienari, J; Lassenius, M I; Forsblom, C; Lehto, M; Saleem, M A; Groop, P-H; Holthöfer, H; Lehtonen, S

    2015-01-01

    High serum lipopolysaccharide (LPS) activity in normoalbuminuric patients with type 1 diabetes (T1D) predicts the progression of diabetic nephropathy (DN), but the mechanisms behind this remain unclear. We observed that treatment of cultured human podocytes with sera from normoalbuminuric T1D patients with high LPS activity downregulated 3-phosphoinositide-dependent kinase-1 (PDK1), an activator of the Akt cell survival pathway, and induced apoptosis. Knockdown of PDK1 in cultured human podocytes inhibited antiapoptotic Akt pathway, stimulated proapoptotic p38 MAPK pathway, and increased apoptosis demonstrating an antiapoptotic role for PDK1 in podocytes. Interestingly, PDK1 was downregulated in the glomeruli of diabetic rats and patients with type 2 diabetes before the onset of proteinuria, further suggesting that reduced expression of PDK1 associates with podocyte injury and development of DN. Treatment of podocytes in vitro and mice in vivo with LPS reduced PDK1 expression and induced apoptosis, which were prevented by inhibiting the Toll-like receptor (TLR) signaling pathway with the immunomodulatory agent GIT27. Our data show that LPS downregulates the cell survival factor PDK1 and induces podocyte apoptosis, and that blocking the TLR pathway with GIT27 may provide a non-nephrotoxic means to prevent the progression of DN. PMID:25950482

  2. 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

  3. Apoptosis by dietary agents for prevention and treatment of prostate cancer

    PubMed Central

    Khan, Naghma; Adhami, Vaqar Mustafa; Mukhtar, Hasan

    2010-01-01

    Accumulating data clearly indicate that induction of apoptosis is an important event for chemoprevention of cancer by naturally occurring dietary agents. In mammalian cells, apoptosis has been divided into two major pathways: the extrinsic pathway, activated by pro-apoptotic receptor signals at the cellular surface; and the intrinsic pathway, which involves the disruption of mitochondrial membrane integrity. This process is strictly controlled in response to integrity of pro-death signaling and plays critical roles in development, maintenance of homeostasis, and host defense in multicellular organisms. For chemoprevention studies, prostate cancer (PCa) represents an ideal disease due to its long latency, its high incidence, tumor marker availability, and identifiable preneoplastic lesions and risk groups. In this article, we highlight the studies of various apoptosis-inducing dietary compounds for prevention of PCa in vitro in cell culture, in preclinical studies in animals, and in human clinical trials. PMID:19926708

  4. Aspartame-induced apoptosis in PC12 cells.

    PubMed

    Horio, Yukari; Sun, Yongkun; Liu, Chuang; Saito, Takeshi; Kurasaki, Masaaki

    2014-01-01

    Aspartame is an artificial sweetner added to many low-calorie foods. The safety of aspartame remains controversial even though there are many studies on its risks. In this study, to understand the physiological effects of trace amounts of artificial sweetners on cells, the effects of aspartame on apoptosis were investigated using a PC12 cell system. In addition, the mechanism of apoptosis induced by aspartame in PC12 cells and effects on apoptotic factors such as cytochrome c, apoptosis-inducing factor, and caspase family proteins were studied by Western blotting and RT-PCR. Aspartame-induced apoptosis in PC12 cells in a dose-dependent manner. In addition, aspartame exposure increased the expressions of caspases 8 and 9, and cytochrome c. These results indicate that aspartame induces apoptosis mainly via mitochondrial pathway involved in apoptosis due to oxigen toxicity.

  5. Tom70 Mediates Sendai Virus-Induced Apoptosis on Mitochondria

    PubMed Central

    Wei, Bo; Cui, Ye; Huang, Yuefeng; Liu, Heng; Li, Lin; Li, Mi; Ruan, Kang-Cheng

    2015-01-01

    ABSTRACT Virus infection triggers immediate innate immune responses. Apoptosis represents another effective means to restrict virus invasion, besides robust expression of host cytokines and chemokines. IRF3 was recently demonstrated to be indispensable for Sendai virus (SeV)-induced apoptosis, but the underlying mechanism is not fully understood. Here we report that a dynamic protein complex, Tom70/Hsp90/IRF3/Bax, mediates SeV-induced apoptosis. The cytosolic proapoptotic protein Bax interacts specifically with IRF3 upon virus infection. The mitochondrial outer membrane protein Tom70 recruits IRF3 to mitochondria via Hsp90. Consequently, the relocation of Bax onto mitochondria induces the leakage of cytochrome c into the cytosol and initiates the corresponding apoptosis. Interestingly, IKK-i is essential for this apoptosis, whereas TBK1 is dispensable. Collectively, our study characterizes a novel protein complex that is important for SeV-induced apoptosis. IMPORTANCE Apoptosis is an effective means of sacrificing virus-infected cells and restraining the spread of virus. In this study, we demonstrate that IRF3 associates with Bax upon virus infection. Tom70 recruits this protein complex to the mitochondrial outer membrane through Hsp90, which thus induces the release of cytochrome c into the cytosol, initiating virus-induced apoptosis. Interestingly, IKK-i plays an essential role in this activation. This study uncovers a novel mechanism of SeV-induced apoptosis. PMID:25609812

  6. De novo-synthesized ceramide is involved in cannabinoid-induced apoptosis.

    PubMed Central

    Gómez del Pulgar, Teresa; Velasco, Guillermo; Sánchez, Cristina; Haro, Amador; Guzmán, Manuel

    2002-01-01

    Delta(9)-Tetrahydrocannabinol (THC) and other cannabinoids have been shown to induce apoptosis of glioma cells via ceramide generation. In the present study, we investigated the metabolic origin of the ceramide responsible for this cannabinoid-induced apoptosis by using two subclones of C6 glioma cells: C6.9, which is sensitive to THC-induced apoptosis; and C6.4, which is resistant to THC-induced apoptosis. Pharmacological inhibition of ceramide synthesis de novo, but not of neutral and acid sphingomyelinases, prevented THC-induced apoptosis in C6.9 cells. The activity of serine palmitoyltransferase (SPT), which catalyses the rate-limiting step of ceramide synthesis de novo, was remarkably enhanced by THC in C6.9 cells, but not in C6.4 cells. However, no major changes in SPT mRNA and protein levels were evident. Changes in SPT activity paralleled changes in ceramide levels. Pharmacological inhibition of ceramide synthesis de novo also prevented the stimulation of extracellular-signal-regulated kinase and the inhibition of protein kinase B triggered by cannabinoids. These findings show that de novo-synthesized ceramide is involved in cannabinoid-induced apoptosis of glioma cells. PMID:11903061

  7. Luteolin inhibits lysophosphatidylcholine-induced apoptosis in endothelial cells by a calcium/mitocondrion/caspases-dependent pathway.

    PubMed

    Song, Junna; Liu, Kang; Yi, Jiali; Zhu, Deqiu; Liu, Gaolin; Liu, Baolin

    2010-03-01

    Luteolin, a naturally occurring polyphenol flavonoid, has demonstrated some beneficial modulation toward the endothelium. This study aims to investigate the effects of luteolin on lysophosphatidylcholine (LPC)-induced apoptosis, a key event in the pathogenesis of atherosclerosis, in endothelial cells. Luteolin reduced not only LPC-induced cell death but also lactate dehydrogenase (LDH) leakage. Luteolin inhibition of LPC-induced apoptosis in endothelial cells demonstrated its protection against the cytotoxicity of LPC. LPC-induced apoptosis is characterized by a calcium-dependent mitochondrial pathway, involving calcium influx, activation of calpains, cytochrome C release and caspases activation. Luteolin reduced calcium influx. It also inhibited calpains activation and prevented the release of cytochrome C from mitochondrion. The inhibition of cytochrome C release by luteolin blocked the activation of caspase-3 and thus prevented subsequent endothelial cell apoptosis. These results suggested that luteolin inhibits LPC-induced apoptosis in endothelial cells through the blockage of the calcium-dependent mitochondrial pathway. PMID:19830654

  8. PKD prevents H{sub 2}O{sub 2}-induced apoptosis via NF-{kappa}B and p38 MAPK in RIE-1 cells

    SciTech Connect

    Song Jun; Li Jing; Qiao Jingbo; Jain, Sunil; Mark Evers, B.; Chung, Dai H.

    2009-01-16

    Previously, we demonstrated that protein kinase D (PKD) plays a protective role during H{sub 2}O{sub 2}-induced intestinal cell death. Here, we sought to determine whether this effect is mediated by nuclear factor-{kappa}B (NF-{kappa}B) and mitogen-activated protein kinases (MAPKs). Treatment with H{sub 2}O{sub 2} activated NF-{kappa}B in RIE-1 cells; H{sub 2}O{sub 2} also induced the translocation of NF-{kappa}B p65 as well as phosphorylation of I{kappa}B-{alpha}. PKD1 siRNA inhibited H{sub 2}O{sub 2}-induced activation, translocation of NF-{kappa}B, and phosphorylation of I{kappa}B-{alpha}. We also found that overexpression of wild type PKD1 attenuated H{sub 2}O{sub 2}-induced phosphorylation of p38 MAPK and its upstream activator, MAPK kinase (MKK) 3/6, whereas the phosphorylation was increased by PKD1 siRNA or kinase-dead PKD1. Phosphorylation of neither extracellular signal-regulated kinases (ERK) 1/2 nor c-Jun N-terminal kinases (JNK) was altered by PKD1 plasmids or siRNA. Our findings suggest that PKD protects intestinal cells through up-regulation of NF-{kappa}B and down-regulation of p38 MAPK.

  9. 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

  10. Mannosylated lipoarabinomannan antagonizes Mycobacterium tuberculosis-induced macrophage apoptosis by altering Ca+2-dependent cell signaling.

    PubMed

    Rojas, M; García, L F; Nigou, J; Puzo, G; Olivier, M

    2000-07-01

    Mycobacterium tuberculosis-induced macrophage apoptosis can be inhibited by mannosylated lipoarabinomannan (ManLAM), although it induces tumor necrosis factor (TNF)-alpha and NO production, which participate in apoptosis induction. ManLAM also modulates Ca(+2)-dependent intracellular events, and Ca(+2) participates in apoptosis in different systems. Ca(+2) was assessed for involvement in M. tuberculosis-induced macrophage apoptosis and for modulation by ManLAM. The role of Ca(+2) was supported by the blockade of apoptosis by cAMP inhibitors and the Ca(+2) chelator, BAPTA/AM. These agents also inhibited caspase-1 activation and cAMP-responsive element-binding protein translocation without affecting TNF-alpha production. Infection of macrophages with M. tuberculosis induced an influx of Ca(+2) that was prevented by ManLAM. Similarly, M. tuberculosis infection-altered mitochondrial permeability transition was prevented by ManLAM and BAPTA/AM. Finally, ManLAM and BAPTA/AM reversed the effects of M. tuberculosis on p53 and Bcl-2 expression. ManLAM counteracts the alterations of calcium-dependent intracellular events that occur during M. tuberculosis-induced macrophage apoptosis.

  11. Carbamate Pesticide-Induced Apoptosis in Human T Lymphocytes

    PubMed Central

    Li, Qing; Kobayashi, Maiko; Kawada, Tomoyuki

    2015-01-01

    We previously found that carbamate pesticides induced significant apoptosis in human natural killer cells. To investigate whether carbamate pesticides also induce apoptosis in human T lymphocytes, in the present study Jurkat human T cells were treated in vitro with thiram, maneb, carbaryl or ziram. Apoptosis was determined by FITC-Annexin-V/PI staining. To explore the mechanism of apoptosis, intracellular levels of active caspase 3 and mitochondrial cytochrome-c release were determined by flow cytometry. We found that thiram, ziram, maneb and carbaryl also induced apoptosis in a time- and dose-dependent manner in the human T cells. However, the strength of the apoptosis-inducing effect differed among the pesticides, with the: thiram > ziram > maneb > carbaryl. Moreover, thiram significantly increased the intracellular level of active caspase 3 and caspase inhibitors significantly inhibited apoptosis. Thiram also significantly caused mitochondrial cytochrome-c release. These findings indicate that carbamate pesticides can induce apoptosis in human T cells, and the apoptosis is mediated by the activation of caspases and the release of mitochondrial cytochrome-c. PMID:25837344

  12. Apoptosis and autophagy induction as mechanism of cancer prevention by naturally occurring dietary agents

    PubMed Central

    Mukhtar, Eiman; Adhami, Vaqar Mustafa; Khan, Naghma; Mukhtar, Hasan

    2013-01-01

    Nontoxic naturally occurring compounds, especially those from dietary sources, are receiving increasing consideration for prevention and treatment of diseases including cancer. There is a growing need for innovative anticancer therapies and therefore search for natural compounds with novel biological activities or antineoplastic potential is currently an important area in drug discovery. Support for this interest also comes from increasing concern over the efficacy and safety of many conventional therapies, especially those that run over a long course of time. Laboratory studies in different in vitro and in vivo systems have shown that many natural compounds possess the capacity to regulate response to oxidative stress and DNA damage, suppress angiogenesis, inhibit cell proliferation and induce autophagy and apoptosis. This review discusses the induction of apoptosis and autophagy as a mechanism of cancer prevention by some of the most studied naturally occurring dietary compounds. PMID:23140293

  13. TNF-alpha/cycloheximide-induced apoptosis in intestinal epithelial cells requires Rac1-regulated reactive oxygen species.

    PubMed

    Jin, Shi; Ray, Ramesh M; Johnson, Leonard R

    2008-04-01

    Previously we have shown that both Rac1 and c-Jun NH(2)-terminal kinase (JNK1/2) are key proapoptotic molecules in tumor necrosis factor (TNF)-alpha/cycloheximide (CHX)-induced apoptosis in intestinal epithelial cells, whereas the role of reactive oxygen species (ROS) in apoptosis is unclear. The present studies tested the hypothesis that Rac1-mediated ROS production is involved in TNF-alpha-induced apoptosis. In this study, we showed that TNF-alpha/CHX-induced ROS production and hydrogen peroxide (H(2)O(2))-induced oxidative stress increased apoptosis. Inhibition of Rac1 by a specific inhibitor NSC23766 prevented TNF-alpha-induced ROS production. The antioxidant, N-acetylcysteine (NAC), or rotenone (Rot), the mitochondrial electron transport chain inhibitor, attenuated mitochondrial ROS production and apoptosis. Rot also prevented JNK1/2 activation during apoptosis. Inhibition of Rac1 by expression of dominant negative Rac1 decreased TNF-alpha-induced mitochondrial ROS production. Moreover, TNF-alpha-induced cytosolic ROS production was inhibited by Rac1 inhibition, diphenyleneiodonium (DPI, an inhibitor of NADPH oxidase), and NAC. In addition, DPI inhibited TNF-alpha-induced apoptosis as judged by morphological changes, DNA fragmentation, and JNK1/2 activation. Mitochondrial membrane potential change is Rac1 or cytosolic ROS dependent. Lastly, all ROS inhibitors inhibited caspase-3 activity. Thus these results indicate that TNF-alpha-induced apoptosis requires Rac1-dependent ROS production in intestinal epithelial cells.

  14. Apoptosis Induced by Metal Complexes and Interaction with Dexamethasone

    PubMed Central

    Kim, Jung Sun; Barros, José Carlos Almeida

    2002-01-01

    Apoptosis induced by rhodium II amidate, rhodium II propionate, cisplatin and interactions with dexamethaxone were studied on some human leukemia cell lines Raji, Jurkat and U937. Apoptosis was studied by flow cytometry, agarose gel electrophoresis and morphological analysis. Rhodium II propionate induced apoptosis in all the three cell lines, Rhodium II amidate, in the lymphoid cell lines Jurkat and Raji, and cisplatin, only in the Jurkat, a T lymphoid cell line. It has also been observed that the addition of dexamethasone enhances the apoptosis index only in U937, a monocytic line with a glucocorticoid receptor bearing. PMID:18476001

  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.

  16. TRX-E-002-1 Induces c-Jun-Dependent Apoptosis in Ovarian Cancer Stem Cells and Prevents Recurrence In Vivo.

    PubMed

    Alvero, Ayesha B; Heaton, Andrew; Lima, Eydis; Pitruzzello, Mary; Sumi, Natalia; Yang-Hartwich, Yang; Cardenas, Carlos; Steinmacher, Sahra; Silasi, Dan-Arin; Brown, David; Mor, Gil

    2016-06-01

    Chemoresistance is a major hurdle in the management of patients with epithelial ovarian cancer and is responsible for its high mortality. Studies have shown that chemoresistance is due to the presence of a subgroup of cancer cells with stemness properties and a high capacity for tumor repair. We have developed a library of super-benzopyran analogues to generate potent compounds that can induce cell death in chemoresistant cancer stem cells. TRX-E-002-1 is identified as the most potent analogue and can induce cell death in all chemoresistant CD44(+)/MyD88(+) ovarian cancer stem cells tested (IC50 = 50 nmol/L). TRX-E-002-1 is also potent against spheroid cultures formed from cancer stem cells, chemosensitive CD44(-)/MyD88(-) ovarian cancer cells, and heterogeneous cultures of ovarian cancer cells. Cell death was associated with the phosphorylation and increased levels of c-Jun and induction of caspases. In vivo, TRX-E-002-1 given as daily intraperitoneal monotherapy at 100 mg/kg significantly decreased intraperitoneal tumor burden compared with vehicle control. When given in combination with cisplatin, animals receiving the combination of cisplatin and TRX-E-002-1 showed decreased tumor burden compared with each monotherapy. Finally, TRX-E-002-1 given as maintenance treatment after paclitaxel significantly delayed disease recurrence. Our results suggest that TRX-E-002-1 may fill the current need for better therapeutic options in the control and management of recurrent ovarian cancer and may help improve patient survival. Mol Cancer Ther; 15(6); 1279-90. ©2016 AACR. PMID:27196760

  17. 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

  18. C-Peptide Prevents Hippocampal Apoptosis in Type 1 Diabetes

    PubMed Central

    Li, Zhen-guo; Zhang, Weixian

    2002-01-01

    To explore mechanisms underlying central nervous system (CNS) complications in diabetes, we examined hippocampal neuronal apoptosis and loss, and the effect of C-peptide replacement in type 1 diabetic BB/W rats. Apoptosis was demonstrated after 8 months of diabetes, by DNA fragmentation, increased number of apoptotic cells, and an elevated ratio of Bax/Bcl-xL, accompanied by reduced neuronal density in the hippocampus. No apoptotic activity was detected and neuronal density was unchanged in 2-month diabetic hippocampus, whereas insulin-like growth factor (IGF) activities were impaired. In type 1 diabetic BB/W rats replaced with C-peptide, no TdT-mediated dUTP nick-end labeling (TUNEL)- positive cells were shown and DNA laddering was not evident in hippocampus at either 2 or 8 months. C-peptide administration prevented the preceding perturbation of IGF expression and reduced the elevated ratio of Bax/Bcl-xL. Our data suggest that type 1 diabetes causes a duration-dependent programmed cell death of the hippocampus, which is partially prevented by C-peptide. PMID:12546277

  19. Anacardic acid induces apoptosis-like cell death in the rice blast fungus Magnaporthe oryzae.

    PubMed

    Muzaffar, Suhail; Bose, Chinchu; Banerji, Ashok; Nair, Bipin G; Chattoo, Bharat B

    2016-01-01

    Anacardic acid (6-pentadecylsalicylic acid), extracted from cashew nut shell liquid, is a natural phenolic lipid well known for its strong antibacterial, antioxidant, and anticancer activities. Its effect has been well studied in bacterial and mammalian systems but remains largely unexplored in fungi. The present study identifies antifungal, cytotoxic, and antioxidant activities of anacardic acid in the rice blast fungus Magnaporthe oryzae. It was found that anacardic acid causes inhibition of conidial germination and mycelial growth in this ascomycetous fungus. Phosphatidylserine externalization, chromatin condensation, DNA degradation, and loss of mitochondrial membrane potential suggest that growth inhibition of fungus is mainly caused by apoptosis-like cell death. Broad-spectrum caspase inhibitor Z-VAD-FMK treatment indicated that anacardic acid induces caspase-independent apoptosis in M. oryzae. Expression of a predicted ortholog of apoptosis-inducing factor (AIF) was upregulated during the process of apoptosis, suggesting the possibility of mitochondria dependent apoptosis via activation of apoptosis-inducing factor. Anacardic acid treatment leads to decrease in reactive oxygen species rather than increase in reactive oxygen species (ROS) accumulation normally observed during apoptosis, confirming the antioxidant properties of anacardic acid as suggested by earlier reports. Our study also shows that anacardic acid renders the fungus highly sensitive to DNA damaging agents like ethyl methanesulfonate (EMS). Treatment of rice leaves with anacardic acid prevents M. oryzae from infecting the plant without affecting the leaf, suggesting that anacardic acid can be an effective antifungal agent. PMID:26381667

  20. Overexpressed TP73 induces apoptosis in medulloblastoma

    PubMed Central

    Castellino, Robert C; De Bortoli, Massimiliano; Lin, Linda L; Skapura, Darlene G; Rajan, Jessen A; Adesina, Adekunle M; Perlaky, Laszlo; Irwin, Meredith S; Kim, John YH

    2007-01-01

    Background Medulloblastoma is the most common malignant brain tumor of childhood. Children who relapse usually die of their disease, which reflects resistance to radiation and/or chemotherapy. Improvements in outcome require a better understanding of the molecular basis of medulloblastoma growth and treatment response. TP73 is a member of the TP53 tumor suppressor gene family that has been found to be overexpressed in a variety of tumors and mediates apoptotic responses to genotoxic stress. In this study, we assessed expression of TP73 RNA species in patient tumor specimens and in medulloblastoma cell lines, and manipulated expression of full-length TAp73 and amino-terminal truncated ΔNp73 to assess their effects on growth. Methods We analyzed medulloblastoma samples from thirty-four pediatric patients and the established medulloblastoma cell lines, Daoy and D283MED, for expression of TP73 RNA including the full-length transcript and the 5'-terminal variants that encode the ΔNp73 isoform, as well as TP53 RNA using quantitative real time-RTPCR. Protein expression of TAp73 and ΔNp73 was quantitated with immunoblotting methods. Clinical outcome was analyzed based on TP73 RNA and p53 protein expression. To determine effects of overexpression or knock-down of TAp73 and ΔNp73 on cell cycle and apoptosis, we analyzed transiently transfected medulloblastoma cell lines with flow cytometric and TUNEL methods. Results Patient medulloblastoma samples and cell lines expressed full-length and 5'-terminal variant TP73 RNA species in 100-fold excess compared to non-neoplastic brain controls. Western immunoblot analysis confirmed their elevated levels of TAp73 and amino-terminal truncated ΔNp73 proteins. Kaplan-Meier analysis revealed trends toward favorable overall and progression-free survival of patients whose tumors display TAp73 RNA overexpression. Overexpression of TAp73 or ΔNp73 induced apoptosis under basal growth conditions in vitro and sensitized them to cell death

  1. Glucocorticoid-induced apoptosis of healthy and malignant lymphocytes

    PubMed Central

    Smith, Lindsay K.; Cidlowski, John A.

    2016-01-01

    Glucocorticoids exert a wide range of physiological effects, including the induction of apoptosis in lymphocytes. The progression of glucocorticoid-induced apoptosis is a multi-component process requiring contributions from both genomic and cytoplasmic signaling events. There is significant evidence indicating that the transactivation activity of the glucocorticoid receptor is required for the initiation of glucocorticoid-induced apoptosis. However, the rapid cytoplasmic effects of glucocorticoids may also contribute to the glucocorticoid-induced apoptosis-signaling pathway. Endogenous glucocorticoids shape the T-cell repertoire through both the induction of apoptosis by neglect during thymocyte maturation and the antagonism of T-cell receptor (TCR)-induced apoptosis during positive selection. Owing to their ability to induce apoptosis in lymphocytes, synthetic glucocorticoids are widely used in the treatment of haematological malignancies. Glucocorticoid chemotherapy is limited, however, by the emergence of glucocorticoid resistance. The development of novel therapies designed to overcome glucocorticoid resistance will dramatically improve the efficacy of glucocorticoid therapy in the treatment of haematological malignancies. PMID:20541659

  2. Involvement of seven in absentia homolog-1 in ethanol-induced apoptosis in neural crest cells

    PubMed Central

    Sun, Haijing; Chen, Xiaopan; Yuan, Fuqiang; Liu, Jie; Zhao, Yingming; Chen, Shao-yu

    2014-01-01

    Ethanol-induced apoptosis in selected cell populations is a major component of pathogenesis underlying ethanol-induced teratogenesis. However, there is a fundamental gap in understanding how ethanol leads to apoptosis in embryos. In this study, we investigate the role of seven in absentia homolog-1 (Siah1) protein, an E3 ubiquitin ligase, in ethanol-induced apoptosis. Using an in vitro model of neural crest cell (NCC), JoMa1.3 cells, we found that exposure to 100 mM ethanol resulted in a significant increase in Siah1 mRNA expression in NCCs, an ethanol-sensitive cell population implicated in Fetal Alcohol Spectrum Disorders (FASD). Treatment with 100 mM ethanol for 24 hours also significantly increased the protein expression of Siah1 in JoMa1.3 cells. The nuclear translocation and accumulation of Siah1 was evidenced in the cells exposed to ethanol. In addition, we have found that the inhibition of Siah1 function with siRNA prevents ethanol-induced increase in Siah1 protein expression and nuclear translocation in NCCs. Down-regulation of Siah1 by siRNA also greatly diminished ethanol-induced cell death and caspase-3 activation, indicating that inhibition of Siah1 can attenuate ethanol-induced apoptosis. These results strongly suggest that Siah1 plays an important role in ethanol-induced apoptosis in NCCs. PMID:25193017

  3. 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.

  4. Mcl-1 downregulation sensitizes glioma to bortezomib-induced apoptosis.

    PubMed

    Zhang, Yang; Zhu, Xiaobo; Hou, Kun; Zhao, Jinchuan; Han, Zhiguo; Zhang, Xiaona

    2015-05-01

    Glioma is the most aggressive form of primary brain tumor, with dismal patient outcome and no effective therapeutic approaches available. Targeting the ubiquitin-proteasome pathway has recently emerged as a potent rational anticancer strategy. Bortezomib, a specific proteasome inhibitor, has been approved for the treatment of relapsed or refractory multiple myeloma and other hematological malignancies as a single agent or as part of a combination therapy. However, bortezomib alone or in combination showed only minimal effects in the treatment of solid tumors. Myeloid cell leukemia-1 (Mcl-1) is an anti-apoptotic protein which protects tumor cells against spontaneous and chemotherapy-induced apoptosis. In multiple myeloma, specific downregulation of Mcl-1 induces apoptosis. Furthermore, previous studies demonstrated that proteasome inhibitors induce Mcl-1 accumulation that, in turn, slows down their pro-apoptotic effects, and the cell survival in multiple myeloma is highly dependent on Mcl-1. In the present study, we investigated the role of Mcl-1 downregulation in bortezomib-induced apoptosis in gliomas. We observed that bortezomib triggers caspase-3 and PARP activation, upregulates cytochrome c expression and induces apoptosis. Furthermore, we demonstrated that effective targeting of Mcl-1 in glioma cells by gene silencing technology augments the glioma cell sensitivity to bortezomib-induced apoptosis. In conclusion, the present study demonstrates that Mcl-1 plays a critical role in bortezomib-induced apoptosis. Mcl-1 inhibitor in combination with bortezomib present a promising novel strategy to trigger cell death pathways in the treatment of gliomas.

  5. Mushroom lectin protects arsenic induced apoptosis in hepatocytes of rodents.

    PubMed

    Rana, Tanmoy; Bera, Asit Kumar; Das, Subhashree; Bhattacharya, Debasis; Pan, Diganta; Bandyopadhyay, Subhasish; De, Sumanta; Das, Subrata Kumar

    2011-04-01

    Acute and chronic arsenic exposure result in toxicity both in human and animal beings and cause many hepatic and renal manifestations. The present study stated that mushroom lectin prevents arsenic-induced apoptosis. Apoptosis was measured by morphological alterations, cell proliferation index (CPI), phagocytic activity (nitro blue tetrazolium index; NBT), nitric oxide (NO) production, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, DNA fragmentation and caspase-3 activity. Arsenic exposure at 5 μM in the form of sodium arsenite resulted in significant elevation of deformed cells, NO production, TUNEL stained nuclei of hepatocytes, DNA fragmentation and caspase-3 activity. But the CPI and NBT index were significantly declined in arsenic-treated hepatocytes. The beneficial effect of mushroom lectin at 10 μg/mL, 20 μg/mL and 50 μg/mL) showed increased CPI and phagocytic activity. Mushroom lectin at those concentrations reduced deformed cells, NO production, DNA fragmentation and caspase-3 activity of hepatocytes. But significant better protection was observed in 50 μg/mL mushroom lectin-treated hepatocytes. This finding may be of therapeutic benefit in people suffering from chronic arsenic exposure.

  6. PDT-induced apoptosis in arterial smooth muscles cells

    NASA Astrophysics Data System (ADS)

    Nyamekye, Isaac; Renick, R.; Gilbert, C.; McEwan, Jean R.; Evan, G.; Bishop, Christopher C. R.; Bown, Stephen G.

    1995-03-01

    PDT kills smooth muscle cells (SMC) in vivo and thus prevents intimal hyperplasia after angioplasty. It causes little inflammation and structural integrity of the artery is not compromised. We have studied the process of the SMC death in vitro. Cultured rat SMC (cell line sv40 ATCC) were sensitized with aluminum disulphonated phthalocyanine (AlS2Pc), and then irradiated with 675 nm laser light (2.5 J/cm2). Controls were studied using only sensitizer or laser for treatment. The cells were incubated and the dying process observed with a time lapse video and microscope system. PDT caused a characteristic pattern of death. Cells lost contact with neighbors, shrank, and showed hyperactivity and membrane ruffling. The cells imploded into active and condensed membrane bound vesicles which were terminally reduced to residual bodies. These are the morphological changes of apoptosis. The control cells which were given AlS2Pc alone or laser alone showed no death. PDT induced cultured arterial SMC death by apoptosis rather than necrosis. An apoptotic mechanism of cell death in vivo would explain the relative lack of inflammation and local tissue destruction in the face of massive death.

  7. HIV-1 viral protein r induces ERK and caspase-8 dependent apoptosis in renal tubular epithelial cells

    PubMed Central

    Snyder, Alexandra; Alsauskas, Zygimantas C.; Leventhal, Jeremy S.; Rosenstiel, Paul E.; Gong, Pengfei; Chan, Justin JK; Barley, Kevin; He, John C.; Klotman, Mary E.; Ross, Michael J.; Klotman, Paul E.

    2010-01-01

    Objective HIV-associated nephropathy is the most common cause of end stage renal disease in persons with HIV/AIDS and is characterized by focal glomerulosclerosis and dysregulated renal tubular epithelial cell (RTEC) proliferation and apoptosis. HIV-1 viral protein r (Vpr) has been implicated in HIV-induced RTEC apoptosis but the mechanisms of Vpr-induced RTEC apoptosis are unknown. The aim of this study was therefore to determine the mechanisms of Vpr-induced apoptosis in RTEC. Methods Apoptosis and caspase activation were analyzed in human RTEC cells (HK2) after transduction with Vpr-expressing and control lentiviral vectors. Bax and BID were inhibited with lentiviral shRNA, and ERK activation was blocked with the MEK1,2 inhibitor, U0126. Results Vpr induced apoptosis as indicated by caspase 3/7 activation, PARP-1 cleavage and mitochondrial injury. Vpr activated both caspases-8 and 9. Inhibition of Bax reduced Vpr-induced apoptosis, as reported in other cell types. Additionally, Vpr induced cleavage of BID to tBID and suppression of BID expression prevented Vpr-induced apoptosis. Since sustained ERK activation can activate caspase-8 in some cell types, we studied the role of ERK in Vpr-induced caspase-8 activation. Vpr induced sustained ERK activation in HK2 cells and incubation with U0126 reduced Vpr-induced caspase-8 activation, BID cleavage and apoptosis. We detected phosphorylated ERK in RTEC in HIVAN biopsy specimens by immunohistochemistry. Conclusions These studies delineate a novel pathway of Vpr-induced apoptosis in RTEC, which is mediated by sustained ERK activation, resulting in caspase 8-mediated cleavage of BID to tBID, thereby facilitating Bax-mediated mitochondrial injury and apoptosis. PMID:20404718

  8. The inhibition of cutaneous T cell apoptosis may prevent resolution of inflammation in atopic eczema

    PubMed Central

    Orteu, C H; Rustin, M H A; O'toole, E; Sabin, C; Salmon, M; Poulter, L W; Akbar, A N

    2000-01-01

    Atopic eczema (AE) is characterized by the persistence of infiltrating T lymphocytes in the dermis. To test the hypothesis that dysregulation of normal T cell apoptosis may contribute to the pathogenesis and chronicity of AE we compared patients with a normal resolving immune response (Mantoux reaction (MR)) induced in healthy volunteers by cutaneous PPD injection. Significantly less T cell apoptosis was observed in lesional skin of AE patients compared with either the peak or the resolution phase of the MR (P < 0·0001). The low incidence of T cell apoptosis in AE was associated with significantly increased levels of Bcl-2 relative to Bax (P < 0·0001) and significantly decreased CD95-L expression (P < 0·002) compared with the resolving MR. The cytokines IL-15 and interferon-beta (IFN-β), which prevent activated T cell apoptosis, were expressed maximally on day 7 and day 14 of the MR, respectively. In contrast, AE patients expressed high levels of both IL-15 and IFN-β in cutaneous lesions at the same time. This suggests that the co-expression of two anti-apoptotic cytokines, which are not found together during resolving cutaneous responses, may contribute to excessive T cell survival which leads to the persistence of inflammation in patients with AE. PMID:11091268

  9. THE ROLE OF GSH EFFLUX IN STAUROSPORINE-INDUCED APOPTOSIS IN COLONIC EPITHELIAL CELLS

    PubMed Central

    Circu, Magdalena L.; Stringer, Sarah; Rhoads, Carol Ann; Moyer, Mary Pat; Aw, Tak Yee

    2008-01-01

    Staurosporine (STP) was shown to induce cell apoptosis through formation of reactive oxygen species, but a role for cellular redox has not been defined. In this study, we report that STP (2μM) caused apoptosis (24±3% at 24h) of human colon adenocarcinoma epithelial cell line HT29 that was preceded by significant GSH and GSSG efflux (6h), but independent of changes in cellular GSH/GSSG redox status. The blockade of GSH efflux by γ-glutamyl glutamate (γ-GG) or ophthalmic acid was associated with apoptosis attenuation; however, γ-GG administration after peak GSH efflux (8h) did not confer cytoprotection. Moreover, lowering cellular GSH through inhibition of its synthesis prevented extracellular GSH accumulation and cell apoptosis, thus validating a link between cellular GSH export and the trigger of cell apoptosis. Inhibition of γ-glutamyl transferase (GGT1 EC 2.3.2.2)-catalyzed extracellular GSH degradation with acivicin significantly blocked GSH efflux, suggesting that GSH breakdown is a driving force for GSH export. Interestingly, acivicin treatment enhanced extracellular GSSG accumulation, consistent with GSH oxidation. STP-induced HT29 cell apoptosis was associated with caspase-3 activation independent of caspase-8 or caspase-9 activity; accordingly, inhibitors of the latter caspases were without effect on STP-induced apoptosis. STP similarly induced GSH efflux and apoptosis in a nonmalignant human NCM460 colonic cell line in association with caspase-3 activation. Collectively, our results demonstrate that STP induction of apoptosis in malignant and non-malignant colonic cells is temporally linked to the export of cellular GSH and the activation of caspase-3 without caspase-8 or -9 involvement. PMID:18840413

  10. N-acetyl-L-cysteine inhibits bleomycin induced apoptosis in malignant testicular germ cell tumors.

    PubMed

    Kucuksayan, Ertan; Cort, Aysegul; Timur, Mujgan; Ozdemir, Evrim; Yucel, Suleyman Gultekin; Ozben, Tomris

    2013-07-01

    Antioxidants may prevent apoptosis of cancer cells via inhibiting reactive oxygen species (ROS). However, to date no study has been carried out to elucidate the effects of strong antioxidant N-acetylcysteine (NAC) on Bleomycin induced apoptosis in human testicular cancer (NTERA-2, NT2) cells. For this reason, we studied the effects of Bleomycin and NAC alone and in combination on apoptotic signaling pathways in NT2 cell line. We determined the cytotoxic effect of bleomycin on NT2 cells and measured apoptosis markers such as Caspase-3, -8, -9 activities and Bcl-2, Bax, Cyt-c, Annexin V-FTIC and PI levels in NT2 cells incubated with different agents for 24 h. Early apoptosis was determined using FACS assay. We found half of the lethal dose (LD50) of Bleomycin on NT2 cell viability as 400, 100, and 20 µg/ml after incubations for 24, 48, and 72 h, respectively. Incubation with bleomycin (LD50 ) and H2O2 for 24 h increased Caspase-3, -8, -9 activities, Cyt-c and Bax levels and decreased Bcl-2 levels. The concurrent incubation of NT2 cells with bleomycin/H2O2 and NAC (5 mM) for 24 h abolished bleomycin/H2O2-dependent increases in Caspase-3, -8, -9 activities, Bax and Cyt-c levels and bleomycin/H2O2-dependent decrease in Bcl-2 level. Our results indicate that bleomycin/H2O2 induce apoptosis in NT2 cells by activating mitochondrial pathway of apoptosis, while NAC diminishes bleomycin/H2O2 induced apoptosis. We conclude that NAC has antagonistic effects on Bleomycin-induced apoptosis in NT2 cells and causes resistance to apoptosis which is not a desired effect in eliminating cancer cells. PMID:23386420

  11. Radiation-induced apoptosis in the eye structures: a review

    NASA Astrophysics Data System (ADS)

    Belkacémi, Yazid; Huchet, Aymeri; Baudouin, Christophe; Lartigau, Éric

    2005-02-01

    Apoptosis plays a crucial role in tissue homeostasis and in the removal of damaged cells from tissues. Both increased and insufficient cell death can lead to human diseases. Apoptotic process is under the control of physiological metabolism as well as a panel of genes. After exposure to radiation, membrane damages induce the membrane pathway signal transduction for cell apoptosis. The importance of the radiation-induced apoptosis in the different ocular tissues and its relationship to the radiation parameters are reviewed in this article. This topic of ocular research has not been addressed in detail in the literature.

  12. Potential autophagy enhancers protect against fipronil-induced apoptosis in SH-SY5Y cells.

    PubMed

    Park, Jae Hyeon; Lee, Jeong Eun; Lee, Soo-Jin; Park, Soo Jin; Park, Kyung Hun; Jeong, Mihye; Koh, Hyun Chul

    2013-10-23

    Oxidative stress created by environmental toxicants activates several signaling pathways. Autophagy is one of the first lines of defense against oxidative stress damage. The autophagy pathway can be induced and up-regulated in response to intracellular reactive oxygen species (ROS). Recently, we reported that fipronil (FPN)-induced mitochondria-dependent apoptosis is mediated through ROS in human neuroblastoma SH-SY5Y cells. In this study, we explored the role of autophagy to prevent FPN neurotoxicity. We investigated the modulation of FPN-induced apoptosis according to autophagy regulation. FPN activated caspase-9 and caspase-3, and induced nuclear fragmentation and condensation, all of which indicate that FPN-induced cell death was due to apoptosis. In addition, we observed FPN-induced autophagic cell death by monitoring the expression of LC3-II and Beclin-1. Exposure to FPN in SH-SY5Y cells led to the production of ROS. Treatment with N-acetyl-cysteine (NAC) effectively blocked both apoptosis and autophagy. Interestingly, pretreatment with rapamycin, an autophagy inducer, significantly enhanced the viability of FPN-exposed cells; the enhancement of cell viability was partially due to alleviation of FPN-induced apoptosis via a decrease in levels of cleaved caspase-3. However, pretreatment with 3-methyladenine (3MA) a specific inhibitor for autophagy, remarkably strengthened FPN toxicity and further induced activation of caspase-3 in these cells. Our studies suggest that FPN-induced cytotoxicity is modified by autophagy regulation and that rapamycin is neuroprotective against FPN-induced apoptosis through enhancing autophagy.

  13. 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

  14. Enoxacin directly inhibits osteoclastogenesis without inducing apoptosis.

    PubMed

    Toro, Edgardo J; Zuo, Jian; Ostrov, David A; Catalfamo, Dana; Bradaschia-Correa, Vivian; Arana-Chavez, Victor; Caridad, Aliana R; Neubert, John K; Wronski, Thomas J; Wallet, Shannon M; Holliday, L Shannon

    2012-05-18

    Enoxacin has been identified as a small molecule inhibitor of binding between the B2-subunit of vacuolar H+-ATPase (V-ATPase) and microfilaments. It inhibits bone resorption by calcitriol-stimulated mouse marrow cultures. We hypothesized that enoxacin acts directly and specifically on osteoclasts by disrupting the interaction between plasma membrane-directed V-ATPases, which contain the osteoclast-selective a3-subunit of V-ATPase, and microfilaments. Consistent with this hypothesis, enoxacin dose-dependently reduced the number of multinuclear cells expressing tartrate-resistant acid phosphatase (TRAP) activity produced by RANK-L-stimulated osteoclast precursors. Enoxacin (50 μM) did not induce apoptosis as measured by TUNEL and caspase-3 assays. V-ATPases containing the a3-subunit, but not the "housekeeping" a1-subunit, were isolated bound to actin. Treatment with enoxacin reduced the association of V-ATPase subunits with the detergent-insoluble cytoskeleton. Quantitative PCR revealed that enoxacin triggered significant reductions in several osteoclast-selective mRNAs, but levels of various osteoclast proteins were not reduced, as determined by quantitative immunoblots, even when their mRNA levels were reduced. Immunoblots demonstrated that proteolytic processing of TRAP5b and the cytoskeletal protein L-plastin was altered in cells treated with 50 μM enoxacin. Flow cytometry revealed that enoxacin treatment favored the expression of high levels of DC-STAMP on the surface of osteoclasts. Our data show that enoxacin directly inhibits osteoclast formation without affecting cell viability by a novel mechanism that involves changes in posttranslational processing and trafficking of several proteins with known roles in osteoclast function. We propose that these effects are downstream to blocking the binding interaction between a3-containing V-ATPases and microfilaments.

  15. Curcumin Induces Apoptosis of Upper Aerodigestive Tract Cancer Cells by Targeting Multiple Pathways

    PubMed Central

    Amin, A. R. M. Ruhul; Haque, Abedul; Rahman, Mohammad Aminur; Chen, Zhuo Georgia; Khuri, Fadlo Raja; Shin, Dong Moon

    2015-01-01

    Curcumin, a natural compound isolated from the Indian spice "Haldi" or "curry powder", has been used for centuries as a traditional remedy for many ailments. Recently, the potential use of curcumin in cancer prevention and therapy urges studies to uncover the molecular mechanisms associated with its anti-tumor effects. In the current manuscript, we investigated the mechanism of curcumin-induced apoptosis in upper aerodigestive tract cancer cell lines and showed that curcumin-induced apoptosis is mediated by the modulation of multiple pathways such as induction of p73, and inhibition of p-AKT and Bcl-2. Treatment of cells with curcumin induced both p53 and the related protein p73 in head and neck and lung cancer cell lines. Inactivation of p73 by dominant negative p73 significantly protected cells from curcumin-induced apoptosis, whereas ablation of p53 by shRNA had no effect. Curcumin treatment also strongly inhibited p-AKT and Bcl-2 and overexpression of constitutively active AKT or Bcl-2 significantly inhibited curcumin-induced apoptosis. Taken together, our findings suggest that curcumin-induced apoptosis is mediated via activating tumor suppressor p73 and inhibiting p-AKT and Bcl-2. PMID:25910231

  16. Chloride channels involve in hydrogen peroxide-induced apoptosis of PC12 cells.

    PubMed

    Zuo, Wanhong; Zhu, Linyan; Bai, Zhiquan; Zhang, Haifeng; Mao, Jianwen; Chen, Lixin; Wang, Liwei

    2009-10-01

    Chloride channel activity is one of the critical factors responsible for cell apoptotic volume decrease (AVD). However, the roles of chloride channels in apoptosis have not been fully understood. In the current study, we assessed the role of chloride channels in hydrogen peroxide (H(2)O(2))-induced apoptosis of pheochromocytoma cells (PC12). Extracellular application of H(2)O(2) activated a chloride current and induced cell volume decrease in a few minutes. Incubation of cells with H(2)O(2) elevated significantly the membrane permeability to the DNA dye Hoechst 33258 in 1h and induced apoptosis of most PC12 cells tested in 24h. The chloride channel blocker NPPB (5-nitro-2-(3-phenylpropylamino)-benzoate) prevented appearance of H(2)O(2)-induced high membrane permeability and cell shrinkage, suppressed H(2)O(2)-activated chloride currents and protected PC12 cells from apoptosis induced by H(2)O(2). The results suggest that chloride channels may contribute to H(2)O(2)-induced apoptosis by ways of elevation of membrane permeability and AVD in PC12 cells.

  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. Cadmium-induced apoptosis is mediated by the translocation of AIF to the nucleus in rat testes.

    PubMed

    Kim, Jisun; Soh, Jaemog

    2009-07-10

    Cadmium (Cd) is a highly toxic metal that affects a variety of cellular events, such as cell proliferation, differentiation and survival. Cd generates reactive oxygen species (ROS) that induce apoptosis. We previously demonstrated that Cd induces apoptosis in testicular germ cells and that apoptosis was prevented by the administration of ascorbic acid (AA), an ROS scavenger. However, little is known about the signaling pathways underlying Cd-induced apoptosis in rat testes. Here, we report that Cd-induced apoptosis in rat testes was associated with the translocation of apoptosis inducing factor (AIF) from mitochondria to the nucleus, and that this was prevented by treatment with AA. Cd-induced cleavage of poly ADP-ribose polymerase-1 (PARP-1), and this was also inhibited by treatment with AA. Taken together, these results suggest that Cd-induced ROS was responsible for the upregulation of PARP-1, the translocation of AIF to the nucleus, and apoptosis of testicular cells in rat testes. PMID:19433269

  20. 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

  1. Curcumin Induces Apoptosis in Pre-B Acute Lymphoblastic Leukemia Cell Lines Via PARP-1 Cleavage.

    PubMed

    Mishra, Deepshikha; Singh, Sunita; Narayan, Gopeshwar

    2016-01-01

    Curcumin, a polyphenolic compound isolated from the rhizomes of an herbaceous perennial plant, Curcuma longa, is known to possess anticancerous activity. However, the mechanism of apoptosis induction in cancers differs. In this study, we have (1) investigated the anticancerous activity of curcumin on REH and RS4;11 leukemia cells and (2) studied the chemo-sensitizing potential of curcumin for doxorubicin, a drug presently used for leukemia treatment. It was found that curcumin induced a dose dependent decrease in cell viability because of apoptosis induction as visualized by annexin V-FITC/ PI staining. Curcumin-induced apoptosis of leukemia cells was mediated by PARP-1 cleavage. An increased level of caspase-3, apoptosis inducing factor (AIF), cleaved PARP-1 and decreased level of Bcl2 was observed in leukemia cells after 24h of curcumin treatment. In addition, curcumin at doses lower than the IC50 value significantly enhanced doxorubicin induced cell death. Therefore, we conclude that curcumin induces apoptosis in leukemia cells via PARP-1 mediated caspase-3 dependent pathway and further may act as a potential chemo-sensitizing agent for doxorubicin. Our study highlights the chemo-preventive and chemo-sensitizing role of curcumin. PMID:27644631

  2. Cold-inducible RNA-binding protein inhibits neuron apoptosis through the suppression of mitochondrial apoptosis.

    PubMed

    Zhang, Hai-Tao; Xue, Jing-Hui; Zhang, Zhi-Wen; Kong, Hai-Bo; Liu, Ai-Jun; Li, Shou-Chun; Xu, Dong-Gang

    2015-10-01

    Cold-inducible RNA-binding protein (CIRP) is induced by mild hypothermia in several mammals, but the precise mechanism by which CIRP mediates hypothermia-induced neuroprotection remains unknown. We aimed to investigate the molecular mechanisms by which CIRP protects the nervous system during mild hypothermia. Rat cortical neurons were isolated and cultured in vitro under mild hypothermia (32°C). Apoptosis was measured by annexin V and propidium iodide staining, visualized by flow cytometry. Neuron ultrastructure was visualized by transmission electron microscopy. CIRP overexpression and knockdown were achieved via infection with pL/IRES/GFP-CIRP and pL/shRNA/F-CIRP-A lentivirus. RT(2) Profiler PCR Array Pathway Analysis and western blotting were used to evaluate the effects of CIRP overexpresion/knockdown on the neurons׳ transcriptome. Neuron late apoptosis was significantly reduced at day 7 of culture by 12h hypothermia, but neuron ultrastructure remained relatively intact. RT(2) Profiler PCR Array Pathway Analysis of 84 apoptosis pathway-associated factors revealed that mild hypothermia and CIRP overexpression induce similar gene expression profiles, specifically alterations of genes implicated in the mitochondrial apoptosis pathway. Mild hypothermia-treated neurons up-regulated 12 and down-regulated 38 apoptosis pathway-associated genes. CIRP-overexpressing neurons up-regulated 15 and down-regulated 46 genes. CIRP-knocked-down hypothermia-treated cells up-regulated 9 and down-regulated 40 genes. Similar results were obtained at the protein level. In conclusion, CIRP may inhibit neuron apoptosis through the suppression of the mitochondria apoptosis pathway during mild hypothermia.

  3. Dihydroartemisinin attenuates lipopolysaccharide-induced osteoclastogenesis and bone loss via the mitochondria-dependent apoptosis pathway

    PubMed Central

    Dou, C; Ding, N; Xing, J; Zhao, C; Kang, F; Hou, T; Quan, H; Chen, Y; Dai, Q; Luo, F; Xu, J; Dong, S

    2016-01-01

    Dihydroartemisinin (DHA) is a widely used antimalarial drug isolated from the plant Artemisia annua. Recent studies suggested that DHA has antitumor effects utilizing its reactive oxygen species (ROS) yielding mechanism. Here, we reported that DHA is inhibitory on lipopolysaccharide (LPS)-induced osteoclast (OC) differentiation, fusion and bone-resorption activity in vitro. Intracellular ROS detection revealed that DHA could remarkably increase ROS accumulation during LPS-induced osteoclastogenesis. Moreover, cell apoptosis was also increased by DHA treatment. We found that DHA-activated caspase-3 increased Bax/Bcl-2 ratio during LPS-induced osteoclastogenesis. Meanwhile, the translocation of apoptotic inducing factor (AIF) and the release of cytochrome c from the mitochondria into the cytosol were observed, indicating that ROS-mediated mitochondrial dysfunction is crucial in DHA-induced apoptosis during LPS-induced osteoclastogenesis. In vivo study showed that DHA treatment decreased OC number, prevents bone loss, rescues bone microarchitecture and restores bone strength in LPS-induced bone-loss mouse model. Together, our findings indicate that DHA is protective against LPS-induced bone loss through apoptosis induction of osteoclasts via ROS accumulation and the mitochondria-dependent apoptosis pathway. Therefore, DHA may be considered as a new therapeutic candidate for treating inflammatory bone loss. PMID:27031959

  4. Dihydroartemisinin attenuates lipopolysaccharide-induced osteoclastogenesis and bone loss via the mitochondria-dependent apoptosis pathway.

    PubMed

    Dou, C; Ding, N; Xing, J; Zhao, C; Kang, F; Hou, T; Quan, H; Chen, Y; Dai, Q; Luo, F; Xu, J; Dong, S

    2016-01-01

    Dihydroartemisinin (DHA) is a widely used antimalarial drug isolated from the plant Artemisia annua. Recent studies suggested that DHA has antitumor effects utilizing its reactive oxygen species (ROS) yielding mechanism. Here, we reported that DHA is inhibitory on lipopolysaccharide (LPS)-induced osteoclast (OC) differentiation, fusion and bone-resorption activity in vitro. Intracellular ROS detection revealed that DHA could remarkably increase ROS accumulation during LPS-induced osteoclastogenesis. Moreover, cell apoptosis was also increased by DHA treatment. We found that DHA-activated caspase-3 increased Bax/Bcl-2 ratio during LPS-induced osteoclastogenesis. Meanwhile, the translocation of apoptotic inducing factor (AIF) and the release of cytochrome c from the mitochondria into the cytosol were observed, indicating that ROS-mediated mitochondrial dysfunction is crucial in DHA-induced apoptosis during LPS-induced osteoclastogenesis. In vivo study showed that DHA treatment decreased OC number, prevents bone loss, rescues bone microarchitecture and restores bone strength in LPS-induced bone-loss mouse model. Together, our findings indicate that DHA is protective against LPS-induced bone loss through apoptosis induction of osteoclasts via ROS accumulation and the mitochondria-dependent apoptosis pathway. Therefore, DHA may be considered as a new therapeutic candidate for treating inflammatory bone loss. PMID:27031959

  5. RGD-FasL Induces Apoptosis in Hepatocellular Carcinoma

    PubMed Central

    Liu, Zhongchen; Wang, Juan; Yin, Ping; Qiu, Jinhua; Liu, Ruizhen; Li, Wenzhu; Fan, Xin; Cheng, Xiaofeng; Chen, Caixia; Zhang, Jiakai; Zhuang, Guohong

    2009-01-01

    Despite impressive results obtained in animal models, the clinical use of Fas ligand (FasL) as an anticancer drug is limited by severe toxicity. Systemic toxicity of death ligands may be prevented by using genes encoding membrane-bound death ligands and by targeted transgene expression through either targeted transduction or targeted transcription. Selective induction of tumor cell death is a promising anticancer strategy. A fusion protein is created by fusing the extracellular domain of Fas ligand (FasL) to the peptide arginine-glycine-aspartic acid (RGD) that selectively targets avβ3-integrins on tumor endothelial cells. The purpose of this study is to evaluate the effects of RGD-FasL on tumor growth and survival in a murine hepatocellular carcinoma (HCC) tumor model. Treatment with RGD-FasL displaying an obvious suppressive effect on the HCC tumor model as compared to that with FasL (p < 0.05) and resulted in a more additive effect on tumor growth delay in this model. RGD-FasL treatment significantly enhanced mouse survival and caused no toxic effect, such as weight loss, organ failure, or other treatment-related toxicities. Apoptosis was detected by flow cytometric analysis and TUNEL assays; those results also showed that RGD-FasL is a more potent inducer of cell apoptosis for H22 and H9101 cell lines than FasL (p < 0.05). In conclusion, RGD-FasL appears to be a low-toxicity selective inducer of tumor cell death, which merits further investigation in preclinical and clinical studies. Furthermore, this approach offers a versatile technology for complexing target ligands with therapeutic recombinant proteins. To distinguish the anti-tumor effects of FasL in vivo, tumor and liver tissues were harvested to examine for evidence of necrotic cells, tumor cells, or apoptotic cells by Hematoxylin and eosin (H&E) staining. PMID:19728930

  6. Does atorvastatin induce aortic smooth muscle cell apoptosis in vivo?

    PubMed

    Doyon, Marielle; Hale, Taben Mary; Huot-Marchand, Julie-Emilie; Wu, Rong; de Champlain, Jacques; DeBlois, Denis

    2011-01-01

    It has been reported that HMG-CoA reductase inhibitors such as atorvastatin induce vascular smooth muscle cell (SMC) apoptosis in vitro. However, this effect remains to be demonstrated in vivo. The present studies were designed to test the ability of atorvastatin to induce SMC apoptosis in vivo, using the spontaneously hypertensive rat (SHR) as a well-known reference model of SMC apoptosis induction in vivo by cardiovascular drugs including the calcium channel blocker amlodipine. Atorvastatin was administered to SHR for 3 or 6 weeks either alone or together with amlodipine, a drug combination clinically available to patients. Primary endpoints included aortic medial hypertrophy and aortic SMC hyperplasia, internucleosomal DNA fragmentation and expression of the apoptosis regulatory proteins Bax and Bcl-2. The SHR aorta showed no evidence of SMC apoptosis induction by atorvastatin, even at the high dose of 50 mg kg(-1) day(-1), although the statin significantly reduced oxidative stress after 3 weeks and blood pressure after 6 weeks of administration. Amlodipine-induced regression of aortic hypertophy and aortic SMC hyperplasia were dose- and time-dependent, but there was no interaction between atorvastatin and amlodipine in modulating the primary endpoints. These results do not support the notion that atorvastatin induces SMC apoptosis in the aortic media in vivo.

  7. Interdependence of Bad and Puma during ionizing-radiation-induced apoptosis.

    PubMed

    Toruno, Cristhian; Carbonneau, Seth; Stewart, Rodney A; Jette, Cicely

    2014-01-01

    Ionizing radiation (IR)-induced DNA double-strand breaks trigger an extensive cellular signaling response that involves the coordination of hundreds of proteins to regulate DNA repair, cell cycle arrest and apoptotic pathways. The cellular outcome often depends on the level of DNA damage as well as the particular cell type. Proliferating zebrafish embryonic neurons are highly sensitive to IR-induced apoptosis, and both p53 and its transcriptional target puma are essential mediators of the response. The BH3-only protein Puma has previously been reported to activate mitochondrial apoptosis through direct interaction with the pro-apoptotic Bcl-2 family proteins Bax and Bak, thus constituting the role of an "activator" BH3-only protein. This distinguishes it from BH3-only proteins like Bad that are thought to indirectly promote apoptosis through binding to anti-apoptotic Bcl-2 family members, thereby preventing the sequestration of activator BH3-only proteins and allowing them to directly interact with and activate Bax and Bak. We have shown previously that overexpression of the BH3-only protein Bad in zebrafish embryos supports normal embryonic development but greatly sensitizes developing neurons to IR-induced apoptosis. While Bad has previously been shown to play only a minor role in promoting IR-induced apoptosis of T cells in mice, we demonstrate that Bad is essential for robust IR-induced apoptosis in zebrafish embryonic neural tissue. Moreover, we found that both p53 and Puma are required for Bad-mediated radiosensitization in vivo. Our findings show the existence of a hierarchical interdependence between Bad and Puma whereby Bad functions as an essential sensitizer and Puma as an essential activator of IR-induced mitochondrial apoptosis specifically in embryonic neural tissue.

  8. Reg2 protects mouse insulinoma cells from streptozotocin-induced mitochondrial disruption and apoptosis.

    PubMed

    Liu, Lu; Liu, Jun-Li; Srikant, Coimbatore B

    2010-10-01

    We reported previously that pancreas-specific ablation of IGF-I in mice induced an increased expression of regenerating family proteins Reg2 and Reg3β in the pancreas and protected them from streptozotocin (Stz)-induced β-cell damage. We, therefore, assessed the effect of ectopically introduced Reg2 on Stz-induced apoptosis in MIN6 mouse insulinoma cells and report here that Reg2 protects MIN6 cells from Stz-induced apoptosis by attenuating its ability to disrupt mitochondrial membrane integrity, activate caspase-3 and promote poly-ADP ribose polymerase cleavage, and induce apoptosis. These changes correlated with suppression of c-jun N-terminal kinase (JNK) phosphorylation by Stz. Reg2 inhibited Stz-induced proapoptotic events as well as the inactivation of JNK. Inclusion of chemical inhibitor of JNK to Reg2 expressing cells rendered them sensitive to Stz. These data demonstrate that Reg2 protects insulin-producing cells against Stz-induced apoptosis by interfering with its cytotoxic signaling upstream of the intrinsic proapoptotic events by preventing its ability to inactivate JNK.

  9. Involvement of reactive oxygen species in 2-methoxyestradiol-induced apoptosis in human neuroblastoma cells.

    PubMed

    Zhang, Qi; Ma, Yan; Cheng, Yue-Fang; Li, Wen-Jie; Zhang, Zhenzhong; Chen, Shao-Yu

    2011-12-27

    Neuroblastoma is the most common extra-cranial solid tumor in children. Despite advances in the treatment of childhood cancer, outcomes for children with advanced-stage neuroblastoma remain poor. Here we reported that 2-methoxyestradiol (2-ME) inhibited the proliferation and induced apoptosis in human neuroblastoma SK-N-SH and SH-SY5Y cells. 2-ME treatment also resulted in the generation of ROS and the loss of mitochondrial membrane potential in SK-N-SH and SH-SY5Y, indicating that 2-ME-induced apoptosis is mediated by ROS. This is supported by the results that have shown that co-treatment with antioxidants, VC, L-GSH and MitoQ(10), decreased 2-ME-induced generation of ROS and the loss of the mitochondrial membrane potential, increased the Bcl-2/Bax ratio, decreased 2-ME-induced activation of caspase-9 and caspase-3 and the up-regulation of apoptosis-inducing factor (AIF), and prevented 2-ME-induced apoptosis in SK-N-SH and SH-SY5Y cells. These results suggested that oxidative stress plays an important role in 2-ME-induced apoptotic death of human neuroblastoma cells.

  10. Simvastatin induces apoptosis by a Rho-dependent mechanism in cultured cardiac fibroblasts and myofibroblasts

    SciTech Connect

    Copaja, Miguel; Venegas, Daniel; Aranguiz, Pablo; Canales, Jimena; Vivar, Raul; Catalan, Mabel; Olmedo, Ivonne; Rodriguez, Andrea E.; Chiong, Mario; Leyton, Lisette; Lavandero, Sergio; Diaz-Araya, Guillermo

    2011-08-15

    Several clinical trials have shown the beneficial effects of statins in the prevention of coronary heart disease. Additionally, statins promote apoptosis in vascular smooth muscle cells, in renal tubular epithelial cells and also in a variety of cell lines; yet, the effects of statins on cardiac fibroblast and myofibroblast, primarily responsible for cardiac tissue healing are almost unknown. Here, we investigated the effects of simvastatin on cardiac fibroblast and myofibroblast viability and studied the molecular cell death mechanism triggered by simvastatin in both cell types. Methods: Rat neonatal cardiac fibroblasts and myofibroblasts were treated with simvastatin (0.1-10 {mu}M) up to 72 h. Cell viability and apoptosis were evaluated by trypan blue exclusion method and by flow cytometry, respectively. Caspase-3 activation and Rho protein levels and activity were also determined by Western blot and pull-down assay, respectively. Results: Simvastatin induces caspase-dependent apoptosis of cardiac fibroblasts and myofibroblasts in a concentration- and time-dependent manner, with greater effects on fibroblasts than myofibroblasts. These effects were prevented by mevalonate, farnesylpyrophosphate and geranylgeranylpyrophosphate, but not squalene. These last results suggest that apoptosis was dependent on small GTPases of the Rho family rather than Ras. Conclusion: Simvastatin triggered apoptosis of cardiac fibroblasts and myofibroblasts by a mechanism independent of cholesterol synthesis, but dependent of isoprenilation of Rho protein. Additionally, cardiac fibroblasts were more susceptible to simvastatin-induced apoptosis than cardiac myofibroblasts. Thus simvastatin could avoid adverse cardiac remodeling leading to a less fibrotic repair of the damaged tissues. - Research Highlights: > Simvastatin decreases CF and CMF viability independent of cholesterol synthesis. > Simvastatin induces CF and CMF apoptosis in a caspase-dependent manner being CMF more resistant

  11. Bisphenol A induces spermatocyte apoptosis in rare minnow Gobiocypris rarus.

    PubMed

    Zhang, Yingying; Cheng, Mengqian; Wu, Lang; Zhang, Guo; Wang, Zaizhao

    2016-10-01

    Bisphenol A (BPA) is an endocrine disruptor, and could induce germ cells apoptosis in the testis of mammals. But whether it could affect fish in the same mechanism has not' been studied till now. In the present study, to investigate the influence of BPA on testis germ cells in fish, adult male rare minnow Gobiocypris rarus were exposed to 225μgL(-1) (0.99μM) BPA for 1, 3 and 9 weeks. Through TdT-mediated dUTP nick end labeling (TUNEL) and transmission electron microscope (TEM) analysis, we found that the amount of apoptotic spermatocytes significantly increased in a time dependent manner following BPA exposure. Western Blot results showed that the ratio of Bcl2/Bax, the important apoptosis regulators in intrinsic mitochondrial apoptotic pathway, was significantly decreased. qPCR showed that mRNA expression of several genes in mitochondrial apoptotic pathway including bcl2, bax, casp9, cytc and mcl1b were significantly changed following BPA exposure. In addition, mRNA expression of meiosis regulation genes (kpna7 and wee2), and genes involved in both apoptosis and meiosis (birc5, ccna1, and gsa1a) were also affected by BPA. Taken together, the present study demonstrated that BPA could induce spermatocytes apoptosis in rare minnow testis, and the apoptosis was probably under regulation of intrinsic mitochondrial apoptotic pathway. Moreover, the spermatocyte apoptosis was likely initiated by BPA induced meiosis arrest. PMID:27561114

  12. Sonodynamic therapy induces the interplay between apoptosis and autophagy in K562 cells through ROS.

    PubMed

    Su, Xiaomin; Wang, Pan; Yang, Shuang; Zhang, Kun; Liu, Quanhong; Wang, Xiaobing

    2015-03-01

    Sonodynamic therapy (SDT) is a relatively new approach in the treatment of various cancers including leukemia cells. The aim of this study is to investigate the occurrence of apoptosis and autophagy after treated by protoporphyrin IX (PpIX)-mediated SDT (PpIX-SDT) on human leukemia K562 cells as well as the relationship between them. Firstly, mitochondrial-dependent apoptosis was observed through morphological observation and biochemical analysis. Meanwhile, SDT was shown to induce autophagy in K562 cells, which caused an increase in EGFP-LC3 puncta cells, a conversion of LC3 II/I, formation of acidic vesicular organelles (AVOs) and co-localization between LC3 and LAMP2 (a lysosome marker). Besides, pretreatment with autophagy inhibitor 3-MA or bafilomycin A1 was shown to provide protection against autophagy and to enhance SDT-induced apoptosis and necrosis, while the apoptosis suppressor z-VAD-fmk failed to affect formation of autophagic vacuoles or partially prevented SDT-induced cytotoxicity, which suggested that SDT-induced autophagy functioned as a survival mechanism. Additionally, this study reported apparent apoptosis and autophagy with dependence on intracellular reactive oxygen species (ROS) production. Preliminary data showed that ROS scavenger N-acetylcysteine (NAC) effectively blocked the SDT induced accumulation of ROS, reversed sono-damage, cell apoptosis and autophagy. Taken together, these data indicate that autophagy may be cytoprotective in our experimental system, and the ROS caused by PpIX-SDT treatment may play an important role in initiating apoptosis and autophagy. PMID:25578562

  13. Mast Cell Stabilization Improves Survival by Preventing Apoptosis in Sepsis

    PubMed Central

    Ramos, Laura; Peña, Geber; Cai, Bolin; Deitch, E. A.; Ulloa, Luis

    2011-01-01

    Inhibiting single cytokines produced modest effects in clinical trials, in part because the cytokines werenot specific for sepsis, and sepsis may require cellular strategies. Previous studies reported that mast cells (MCs) fight infections in early sepsis. In this study, we report that MC stabilizers restrain serum TNF levels and improve survival in wild-type but not in MC-deficient mice. Yet, MC depletion in knockout mice attenuates serum TNF but does not improve survival in sepsis. Serum HMGB1 was the only factor correlating with survival. MC stabilizers inhibit systemic HMGB1 levels and rescue mice from established peritonitis. MC stabilizers fail to inhibit HMGB1 secretion from macrophages, but they prevent apoptosis and caspase-3 activation in sepsis. These results suggest that MC stabilization provides therapeutic benefits in sepsis by inhibiting extracellular release of HMGB1 from apoptotic cells. Our study provides the first evidence that MCs have major immunological implications regulating cell death in sepsis and represent a pharmacological target for infectious disorders in a clinically realistic time frame. PMID:20519642

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

    PubMed

    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

    2016-03-01

    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.

  15. 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

  16. Effects of cerebrolysin administration on oxidative stress-induced apoptosis in lymphocytes from CADASIL patients.

    PubMed

    Formichi, Patrizia; Radi, Elena; Battisti, Carla; Di Maio, Giuseppe; Dotti, Maria Teresa; Muresanu, Dafin; Federico, Antonio

    2013-04-01

    Cerebrolysin (Cere) is a peptidergic nootropic drug with neurotrophic properties which has been used to treat dementia and sequelae of stroke. Use of Cere prevents nuclear structural changes typical of apoptosis and significantly reduces the number of apoptotic cells after several apoptotic stimuli. Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) is a hereditary disease caused by mutations of the Notch3 gene encoding the Notch3 protein. Notch3 is involved in the regulation of apoptosis, modulating Fas-Ligand (Fas-L)- induced apoptosis. The aim of this study was to evaluate the in vitro protective effects of Cere against oxidative stress-induced apoptosis in cells from CADASIL patients. We used peripheral blood lymphocytes (PBLs) from 15 CADASIL patients (age range 34-70 years); 2-deoxy-D-ribose (dRib), a highly reducing sugar, was used as paradigm pro-apoptotic stimulus. Apoptosis was analyzed by flow cytometry and fluorescence microscopy. Administration of Cere to PBLs from CADASIL patients cultured under standard conditions had no effect on the percentage of apoptotic cells. Administration of Cere to PBLs cultured with dRib caused a significant decrease in apoptosis after 48 h of culture in only 5 patients, whereas in the other 10 patients, Cere treatment was not associated with any significant difference in the percentage of apoptosis. This result showed a protective effect of Cere against oxidative stress-induced apoptosis only in 30 % of the CADASIL patients, suggesting that the Notch3 gene probably does not influence the anti-apoptotic properties of Cere in vitro.

  17. Low-power laser irradiation inhibits amyloid beta-induced cell apoptosis

    NASA Astrophysics Data System (ADS)

    Zhang, Heng; Wu, Shengnan

    2011-03-01

    The deposition and accumulation of amyloid-β-peptide (Aβ) in the brain are considered a pathological hallmark of Alzheimer's disease(AD). Apoptosis is a contributing pathophysiological mechanism of AD. Low-power laser irradiation (LPLI), a non-damage physical therapy, which has been used clinically for decades of years, is shown to promote cell proliferation and prevent apoptosis. Recently, low-power laser irradiation (LPLI) has been applied to moderate AD. In this study, Rat pheochromocytoma (PC12) cells were treated with amyloid beta 25-35 (Aβ25-35) for induction of apoptosis before LPLI treatment. We measured cell viability with CCK-8 according to the manufacture's protocol, the cell viability assays show that low fluence of LPLI (2 J/cm2 ) could inhibit the cells apoptosis. Then using statistical analysis of proportion of apoptotic cells by flow cytometry based on Annexin V-FITC/PI, the assays also reveal that low fluence of LPLI (2 J/cm2 ) could inhibit the Aβ-induced cell apoptosis. Taken together, we demonstrated that low fluence of LPLI (2 J/cm2 ) could inhibit the Aβ-induced cell apoptosis, these results directly point to a therapeutic strategy for the treatment of AD through LPLI.

  18. H2O2 intensifies CN(-)-induced apoptosis in pea leaves.

    PubMed

    Samuilov, V D; Kiselevsky, D B; Sinitsyn, S V; Shestak, A A; Lagunova, E M; Nesov, A V

    2006-04-01

    H2O2 intensifies CN(-)-induced apoptosis in stoma guard cells and to lesser degree in basic epidermal cells in peels of the lower epidermis isolated from pea leaves. The maximum effect of H2O2 on guard cells was observed at 10(-4) M. By switching on non-cyclic electron transfer in chloroplasts menadione and methyl viologen intensified H2O2 generation in the light, but prevented the CN--induced apoptosis in guard cells. The light stimulation of CN- effect on guard cell apoptosis cannot be caused by disturbance of the ribulose-1,5-bisphosphate carboxylase function and associated OH* generation in chloroplasts with participation of free transition metals in the Fenton or Haber-Weiss type reactions as well as with participation of the FeS clusters of the electron acceptor side of Photosystem I. Menadione and methyl viologen did not suppress the CN(-)-induced apoptosis in epidermal cells that, unlike guard cells, contain mitochondria only, but not chloroplasts. Quinacrine and diphenylene iodonium, inhibitors of NAD(P)H oxidase of cell plasma membrane, had no effect on the respiration and photosynthetic O2 evolution by leaf slices, but prevented the CN(-)-induced guard cell death. The data suggest that NAD(P)H oxidase of guard cell plasma membrane is a source of reactive oxygen species (ROS) needed for execution of CN(-)-induced programmed cell death. Chloroplasts and mitochondria were inefficient as ROS sources in the programmed death of guard cells. When ROS generation is insufficient, exogenous H2O2 exhibits a stimulating effect on programmed cell death. H2O2 decreased the inhibitory effects of DCMU and DNP-INT on the CN(-)-induced apoptosis of guard cells. Quinacrine, DCMU, and DNP-INT had no effect on CN(-)-induced death of epidermal cells.

  19. Caspase-9 mediates Puma activation in UCN-01-induced apoptosis.

    PubMed

    Nie, C; Luo, Y; Zhao, X; Luo, N; Tong, A; Liu, X; Yuan, Z; Wang, C; Wei, Y

    2014-10-30

    The protein kinase inhibitor 7-hydroxystaurosporine (UCN-01) is one of the most potent and frequently used proapoptotic stimuli. The BH3-only molecule of Bcl-2 family proteins has been reported to contribute to UCN-01-induced apoptosis. Here we have found that UCN-01 triggers Puma-induced mitochondrial apoptosis pathway. Our data confirmed that Akt-FoxO3a pathway mediated Puma activation. Importantly, we elucidate the detailed mechanisms of Puma-induced apoptosis. Our data have also demonstrated that caspase-9 is a decisive molecule of Puma induction after UCN-01 treatment. Caspase-9 mediates apoptosis through two kinds of feedback loops. On the one hand, caspase-9 enhances Puma activation by cleaving Bcl-2 and Bcl-xL independent of caspase-3. On the other hand, caspase-9 directly activated caspase-3 in the presence of caspase-3. Caspase-3 could cleave XIAP in an another positive feedback loop to further sensitize cancer cells to UCN-01-induced apoptosis. Therefore, caspase-9 mediates Puma activation to determine the threshold for overcoming chemoresistance in cancer cells.

  20. Autophagy regulates colistin-induced apoptosis in PC-12 cells.

    PubMed

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

    2015-04-01

    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.

  1. Infection of human fallopian tube epithelial cells with Neisseria gonorrhoeae protects cells from tumor necrosis factor alpha-induced apoptosis.

    PubMed

    Morales, Priscilla; Reyes, Paz; Vargas, Macarena; Rios, Miguel; Imarai, Mónica; Cardenas, Hugo; Croxatto, Horacio; Orihuela, Pedro; Vargas, Renato; Fuhrer, Juan; Heckels, John E; Christodoulides, Myron; Velasquez, Luis

    2006-06-01

    Following infection with Neisseria gonorrhoeae, bacteria may ascend into the Fallopian tubes (FT) and induce salpingitis, a major cause of infertility. In the FT, interactions between mucosal epithelial cells and gonococci are pivotal events in the pathogen's infection cycle and the inflammatory response. In the current study, primary FT epithelial cells were infected in vitro with different multiplicities of infection (MOI) of Pil+ Opa+ gonococci. Bacteria showed a dose-dependent association with cells and induced the secretion of tumor necrosis factor alpha (TNF-alpha). A significant finding was that gonococcal infection (MOI = 1) induced apoptosis in approximately 30% of cells, whereas increasing numbers of bacteria (MOI = 10 to 100) did not induce apoptosis. Apoptosis was observed in only 11% of cells with associated bacteria, whereas >84% of cells with no adherent bacteria were apoptotic. TNF-alpha was a key contributor to apoptosis, since (i) culture supernatants from cells infected with gonococci (MOI = 1) induced apoptosis in naïve cultures, suggesting that a soluble factor was responsible; (ii) gonococcal infection-induced apoptosis was inhibited with anti-TNF-alpha antibodies; and (iii) the addition of exogenous TNF-alpha induced apoptosis, which was inhibited by the presence of increasing numbers of bacteria (MOI = 10 to 100). These data suggest that TNF-alpha-mediated apoptosis of FT epithelial cells is likely a primary host defense mechanism to prevent pathogen colonization. However, epithelial cell-associated gonococci have evolved a mechanism to protect the cells from undergoing TNF-alpha-mediated apoptosis, and this modulation of the host innate response may contribute to establishment of infection. Understanding the antiapoptotic mechanisms used by Neisseria gonorrhoeae will inform the pathogenesis of salpingitis and could suggest new intervention strategies for prevention and treatment of the disease. PMID:16714596

  2. Infection of Human Fallopian Tube Epithelial Cells with Neisseria gonorrhoeae Protects Cells from Tumor Necrosis Factor Alpha-Induced Apoptosis

    PubMed Central

    Morales, Priscilla; Reyes, Paz; Vargas, Macarena; Rios, Miguel; Imarai, Mónica; Cardenas, Hugo; Croxatto, Horacio; Orihuela, Pedro; Vargas, Renato; Fuhrer, Juan; Heckels, John E.; Christodoulides, Myron; Velasquez, Luis

    2006-01-01

    Following infection with Neisseria gonorrhoeae, bacteria may ascend into the Fallopian tubes (FT) and induce salpingitis, a major cause of infertility. In the FT, interactions between mucosal epithelial cells and gonococci are pivotal events in the pathogen's infection cycle and the inflammatory response. In the current study, primary FT epithelial cells were infected in vitro with different multiplicities of infection (MOI) of Pil+ Opa+ gonococci. Bacteria showed a dose-dependent association with cells and induced the secretion of tumor necrosis factor alpha (TNF-α). A significant finding was that gonococcal infection (MOI = 1) induced apoptosis in approximately 30% of cells, whereas increasing numbers of bacteria (MOI = 10 to 100) did not induce apoptosis. Apoptosis was observed in only 11% of cells with associated bacteria, whereas >84% of cells with no adherent bacteria were apoptotic. TNF-α was a key contributor to apoptosis, since (i) culture supernatants from cells infected with gonococci (MOI = 1) induced apoptosis in naïve cultures, suggesting that a soluble factor was responsible; (ii) gonococcal infection-induced apoptosis was inhibited with anti-TNF-α antibodies; and (iii) the addition of exogenous TNF-α induced apoptosis, which was inhibited by the presence of increasing numbers of bacteria (MOI = 10 to 100). These data suggest that TNF-α-mediated apoptosis of FT epithelial cells is likely a primary host defense mechanism to prevent pathogen colonization. However, epithelial cell-associated gonococci have evolved a mechanism to protect the cells from undergoing TNF-α-mediated apoptosis, and this modulation of the host innate response may contribute to establishment of infection. Understanding the antiapoptotic mechanisms used by Neisseria gonorrhoeae will inform the pathogenesis of salpingitis and could suggest new intervention strategies for prevention and treatment of the disease. PMID:16714596

  3. 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.

  4. atRA-induced apoptosis of mouse embryonic palate mesenchymal cells involves activation of MAPK pathway

    SciTech Connect

    Yu Zengli . E-mail: yuzengli@263.net; Xing Ying . E-mail: xingy@zzu.edu.cn

    2006-08-15

    Our previous studies have shown that atRA treatment resulted in cell-cycle block and growth inhibition in mouse embryonic palatal mesenchymal (MEPM). In the current study, gestation day (GD) 13 MEPM cells were used to test the hypothesis that the growth inhibition by atRA is due to apoptosis. The effects of atRA on apoptosis were assessed by performing MTT assay, Cell Death Detection ELISA and flow cytometry, respectively. Data analysis confirmed that atRA treatment induced apoptosis-like cell death, as shown by decreased cell viability and increased fragmented DNA and sub-G1 fraction. atRA-induced apoptosis was associated with upregulation of bcl-2, translocation of bax protein to the mitochondria from the cytosol, activation of caspase-3 and cytochrome c release into cytosol. atRA-induced apoptosis was abrogated by z-DEVD-fmk, a caspase-3 specific inhibitor, and z-VAD-fmk, a general caspase inhibitor, suggesting that the atRA-induced cell death of MEPM cells occurs through the cytochrome c- and caspase-3-dependent pathways. In addition, atRA treatment caused a strong and sustained activation of c-Jun N-terminal kinase (JNK) and p38 kinase (p38), as well as an early but transient activation of extracellular signal-regulated kinase (ERK). Importantly, atRA-induced DNA fragmentation and capase-3 activation were prevented by pretreatment with the JNK inhibitor (SP600125) and the p38 MAPK inhibitor (SB202190), but not by pretreatment with MEK inhibitor (U0126). From these results, we suggest that mitogen-activated protein kinase-dependent pathways is involved in the atRA-induced apoptosis of MEPM cells.

  5. Cigarette smoking induces heat shock protein 70 kDa expression and apoptosis in rat brain: Modulation by bacoside A.

    PubMed

    Anbarasi, K; Kathirvel, G; Vani, G; Jayaraman, G; Shyamala Devi, C S

    2006-01-01

    Cigarette smoking is associated with the development of several diseases and antioxidants play a major role in the prevention of smoking-related diseases. Apoptosis is suggested as a possible contributing factor in the pathogenesis of smoking-induced toxicity. Therefore the present study was designed to investigate the influence of chronic cigarette smoke exposure on apoptosis and the modulatory effect of bacoside A (triterpenoid saponin isolated from the plant Bacopa monniera) on smoking-induced apoptosis in rat brain. Adult male albino rats of Wistar strain were exposed to cigarette smoke and simultaneously administered with bacoside A (10 mg/kg b.w./day, orally) for a period of 12 weeks. Expression of brain hsp70 was analyzed by Western blotting. Apoptosis was identified by DNA fragmentation, terminal deoxynucleotidyl transferase-mediated deoxy uridine triphosphate nick end labeling (TUNEL) staining and transmission electron microscopy. The results showed that exposure to cigarette smoke induced hsp70 expression and apoptosis as characterized by DNA laddering, increased TUNEL-positive cells and ultrastructural apoptotic features in the brain. Administration of bacoside A prevented expression of hsp70 and neuronal apoptosis during cigarette smoking. We speculate that apoptosis may be responsible for the smoking-induced brain damage and bacoside A can protect the brain from the toxic effects of cigarette smoking.

  6. The novel NF-κB inhibitor IMD-0354 induces apoptosis in chronic lymphocytic leukemia.

    PubMed

    Kanduri, M; Tobin, G; Aleskog, A; Nilsson, K; Rosenquist, R

    2011-03-01

    Nuclear factor-κB (NF-κB) is an important regulator of cell survival and has been shown to be constitutively active in chronic lymphocytic leukemia (CLL) cells. Recently, a novel NF-κB inhibitor, IMD-0354 (N-(3, 5-bis-trifluoromethyl-phenyl)-5-chloro-2-hydroxy-benzamide), was shown to specifically inhibit the phosphorylation of IκBα by IkB kinases, thus preventing NF-κB release. In this study, we investigated if IMD-0354 can inhibit NF-κB activation and induce apoptosis in CLL cells in vitro. The rate of increase in apoptosis, drug sensitivity and DNA-binding activity of NF-κB were studied using Annexin V stainings, the fluorometric microculture cytotoxicity assay and electrophoretic mobility shift assay, respectively. Finally, the impact of IMD-0354 treatment on the expression of a set of apoptosis-related genes was investigated. The results clearly show that IMD-0354 induced apoptosis (mean 26%, range 8-48%) in CLL cells, independent of immunoglobulin heavy variable (IGHV) gene mutational status, and showed a dose-dependent cytotoxic effect. IMD-0354 treatment also significantly lowered the DNA-binding activity of NF-κB in CLL cells. In addition, we identified differences in expression levels of pro- and antiapoptotic genes following IMD-0354 treatment. In summary, our novel findings show that IMD-0354 can induce apoptosis in CLL cells, and thus merits further investigation as an anticancer agent in vivo. PMID:22829125

  7. Protein Phosphatase 2A Mediates Oxidative Stress Induced Apoptosis in Osteoblasts.

    PubMed

    Huang, Chong-xin; Lv, Bo; Wang, Yue

    2015-01-01

    Osteoporosis is one of the most common bone diseases, which is characterized by a systemic impairment of bone mass and fragility fractures. Age-related oxidative stress is highly associated with impaired osteoblastic dysfunctions and subsequent osteoporosis. In osteoblasts (bone formation cells), reactive oxygen species (ROS) are continuously generated and further cause lipid peroxidation, protein damage, and DNA lesions, leading to osteoblastic dysfunctions, dysdifferentiations, and apoptosis. Although much progress has been made, the mechanism responsible for oxidative stress induced cellular alternations and osteoblastic toxicity is still not fully elucidated. Here, we demonstrate that protein phosphatase 2A (PP2A), a major protein phosphatase in mammalian cells, mediates oxidative stress induced apoptosis in osteoblasts. Our results showed that lipid peroxidation products (4-HNE) may induce dramatic oxidative stress, inflammatory reactions, and apoptosis in osteoblasts. These oxidative stress responses may ectopically activate PP2A phosphatase activity, which may be mediated by inactivation of AKT/mTOR pathway. Moreover, inhibition of PP2A activity by okadaic acid might partly prevent osteoblastic apoptosis under oxidative conditions. These findings may reveal a novel mechanism to clarify the role of oxidative stress for osteoblastic apoptosis and provide new possibilities for the treatment of related bone diseases, such as osteoporosis. PMID:26538836

  8. The effects of onion (Allium cepa) extract on doxorubicin-induced apoptosis in aortic endothelial cells.

    PubMed

    Alpsoy, Seref; Uygur, Ramazan; Aktas, Cevat; Topcu, Birol; Kanter, Mehmet; Erboga, Mustafa; Karakaya, Osman; Gedikbasi, Asuman

    2013-05-01

    The aim of this study was to investigate the effects of onion (Allium cepa) extracts (ACE) on doxorubicin (DOX)-induced apoptosis in aortic endothelial cells. The rats in the ACE-pretreated group were given a daily dose of 1 ml ACE for 14 days. To induce aortic endothelial cell apoptosis, DOX (30 mg kg(-1) body weight) was injected intraperitoneally by a single dose and the rats were sacrificed after 48 h. To date, no such studies have been performed on antiapoptotic potential of ACE on DOX-induced apoptosis in aortic endothelial cells. Our data indicate a significant reduction in the activity of in situ identification of apoptosis using terminal dUTP nick end-labeling in aortic endothelial cells of the DOX-treated group with ACE therapy. DOX-treated with ACE groups showed a significant decrease in malondialdehyde levels and increased levels of glutathione in comparison with the DOX-treated group. Data from our study show that prevention of endothelial cell apoptosis by ACE may contribute to the restoration of aortic endothelial dysfunction that is associated with DOX treatment.

  9. Anticancer effect of xanthohumol induces growth inhibition and apoptosis of human liver cancer through NF-κB/p53-apoptosis signaling pathway.

    PubMed

    Zhao, Xiangqian; Jiang, Kai; Liang, Bin; Huang, Xiaoqiang

    2016-02-01

    Xanthohumol may prevent and cure diabetes and atherosis, have oxidation resistance and antiviral function as well as anticancer effect preventing cancer cell metastasis. We investigate whether the anticancer effect of xanthohumol induces growth inhibition and apoptosis of human liver cancer through NF-κB/p53-apoptosis signaling pathway. Human liver cancer HepG2 cell were treated with 10, 20, 30 and 40 µM xanthohumol for 48 h. The present study showed that the anticancer effect of xanthohumol was effective in inhibiting proliferation and inducing apoptosis of human liver cancer HepG2 cells. Furthermore, the caspase-3 activity of human liver cancer HepG2 cells was increased by xanthohumol. In addition, 48-h treatment with xanthohumol suppressed NF-κB expression and promoted p53, cleaved PARP, AIF and cytochrome c expression and downregulated XIAP and Bcl-2/Bax expression in human liver cancer HepG2 cells. Therefore, the anticancer effect of xanthohumol induces growth inhibition and apoptosis of human liver cancer through the NF-κB/p53-apoptosis signaling pathway. PMID:26718026

  10. Anticancer effect of xanthohumol induces growth inhibition and apoptosis of human liver cancer through NF-κB/p53-apoptosis signaling pathway

    PubMed Central

    ZHAO, XIANGQIAN; JIANG, KAI; LIANG, BIN; HUANG, XIAOQIANG

    2016-01-01

    Xanthohumol may prevent and cure diabetes and atherosis, have oxidation resistance and antiviral function as well as anticancer effect preventing cancer cell metastasis. We investigate whether the anticancer effect of xanthohumol induces growth inhibition and apoptosis of human liver cancer through NF-κB/p53-apoptosis signaling pathway. Human liver cancer HepG2 cell were treated with 10, 20, 30 and 40 µM xanthohumol for 48 h. The present study showed that the anticancer effect of xanthohumol was effective in inhibiting proliferation and inducing apoptosis of human liver cancer HepG2 cells. Furthermore, the caspase-3 activity of human liver cancer HepG2 cells was increased by xanthohumol. In addition, 48-h treatment with xanthohumol suppressed NF-κB expression and promoted p53, cleaved PARP, AIF and cytochrome c expression and downregulated XIAP and Bcl-2/Bax expression in human liver cancer HepG2 cells. Therefore, the anticancer effect of xanthohumol induces growth inhibition and apoptosis of human liver cancer through the NF-κB/p53-apoptosis signaling pathway. PMID:26718026

  11. Sirt1 protects against oxidative stress-induced renal tubular cell apoptosis by the bidirectional regulation of catalase expression

    SciTech Connect

    Hasegawa, Kazuhiro; Wakino, Shu Yoshioka, Kyoko; Tatematsu, Satoru; Hara, Yoshikazu; Minakuchi, Hitoshi; Washida, Naoki; Tokuyama, Hirobumi; Hayashi, Koichi; Itoh, Hiroshi

    2008-07-18

    NAD{sup +}-dependent protein deacetylase Sirt1 regulates cellular apoptosis. We examined the role of Sirt1 in renal tubular cell apoptosis by using HK-2 cells, proximal tubular cell lines with or without reactive oxygen species (ROS), H{sub 2}O{sub 2}. Without any ROS, Sirt1 inhibitors enhanced apoptosis and the expression of ROS scavenger, catalase, and Sirt1 overexpression downregulated catalase. When apoptosis was induced with H{sub 2}O{sub 2}, Sirt1 was upregulated with the concomitant increase in catalase expression. Sirt1 overexpression rescued H{sub 2}O{sub 2}-induced apoptosis through the upregulation of catalase. H{sub 2}O{sub 2} induced the nuclear accumulation of forkhead transcription factor, FoxO3a and the gene silencing of FoxO3a enhanced H{sub 2}O{sub 2}-induced apoptosis. In conclusion, endogenous Sirt1 maintains cell survival by regulating catalase expression and by preventing the depletion of ROS required for cell survival. In contrast, excess ROS upregulates Sirt1, which activates FoxO3a and catalase leading to rescuing apoptosis. Thus, Sirt1 constitutes a determinant of renal tubular cell apoptosis by regulating cellular ROS levels.

  12. 3,4,5-Tricaffeoylquinic Acid Attenuates TRAIL-induced Apoptosis in Human Keratinocytes by Suppressing Apoptosis-related Protein Activation.

    PubMed

    Lee, Da Hee; Nam, Yoon Jeong; Lee, Min Sung; Sohn, Dong Suep; Shin, Yong Kyoo; Lee, Chung Soo

    2015-10-01

    Caffeoyl derivatives exhibit antiinflammatory and antioxidant effects. However, the effect of 3,4,5-tricaffeoylquinic acid on the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis in keratinocytes that may be involved in skin diseases has not been studied. In this respect, we investigated the effect of 3,4,5-tricaffeoylquinic acid on TRAIL-induced apoptosis in human keratinocytes. 3,4,5-Tricaffeoylquinic acid and oxidant scavengers attenuated the decrease in the cytosolic levels of Bid, Bcl-2, and survivin proteins; the increase in the levels of cytosolic Bax, p53, and phosphorylated p53; the increase in the levels of phosphorylated p38; the increase in the mitochondrial levels of the voltage-dependent anion channel; loss of the mitochondrial transmembrane potential; the release of cytochrome c; activation of caspases (8, 9, and 3); cleavage of poly [ADP-ribose] polymerase-1; production of reactive oxygen species; the depletion of glutathione (GSH); nuclear damage; and cell death in keratinocytes treated with TRAIL. These results suggest that 3,4,5-tricaffeoylquinic acid may reduce TRAIL-induced apoptosis in human keratinocytes by suppressing the activation of the caspase-8 and Bid pathways and the mitochondria-mediated cell death pathway. The effect appears to be associated with the inhibitory effect on the production of reactive oxygen species and depletion of GSH. 3,4,5-Tricaffeoylquinic acid appears to be effective in the prevention of TRAIL-induced apoptosis-mediated skin diseases.

  13. 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

  14. Influenza virus induces apoptosis via BAD-mediated mitochondrial dysregulation.

    PubMed

    Tran, Anh T; Cortens, John P; Du, Qiujiang; Wilkins, John A; Coombs, Kevin M

    2013-01-01

    Influenza virus infection results in host cell death and major tissue damage. Specific components of the apoptotic pathway, a signaling cascade that ultimately leads to cell death, are implicated in promoting influenza virus replication. BAD is a cell death regulator that constitutes a critical control point in the intrinsic apoptosis pathway, which occurs through the dysregulation of mitochondrial outer membrane permeabilization and the subsequent activation of downstream apoptogenic factors. Here we report a novel proviral role for the proapoptotic protein BAD in influenza virus replication. We show that influenza virus-induced cytopathology and cell death are considerably inhibited in BAD knockdown cells and that both virus replication and viral protein production are dramatically reduced, which suggests that virus-induced apoptosis is BAD dependent. Our data showed that influenza viruses induced phosphorylation of BAD at residues S112 and S136 in a temporal manner. Viral infection also induced BAD cleavage, late in the viral life cycle, to a truncated form that is reportedly a more potent inducer of apoptosis. We further demonstrate that knockdown of BAD resulted in reduced cytochrome c release and suppression of the intrinsic apoptotic pathway during influenza virus replication, as seen by an inhibition of caspases-3, caspase-7, and procyclic acidic repetitive protein (PARP) cleavage. Our data indicate that influenza viruses carefully modulate the activation of the apoptotic pathway that is dependent on the regulatory function of BAD and that failure of apoptosis activation resulted in unproductive viral replication.

  15. Hesperidin Attenuates Ultraviolet B-Induced Apoptosis by Mitigating Oxidative Stress in Human Keratinocytes

    PubMed Central

    Hewage, Susara Ruwan Kumara Madduma; Piao, Mei Jing; Kang, Kyoung Ah; Ryu, Yea Seong; Han, Xia; Oh, Min Chang; Jung, Uhee; Kim, In Gyu; Hyun, Jin Won

    2016-01-01

    Human skin cells undergo pathophysiological processes via generation of reactive oxygen species (ROS) upon excessive exposure to ultraviolet B (UVB) radiation. This study investigated the ability of hesperidin (C28H34O15) to prevent apoptosis due to oxidative stress generated through UVB-induced ROS. Hesperidin significantly scavenged ROS generated by UVB radiation, attenuated the oxidation of cellular macromolecules, established mitochondrial membrane polarization, and prevented the release of cytochrome c into the cytosol. Hesperidin downregulated expression of caspase-9, caspase-3, and Bcl-2-associated X protein, and upregulated expression of B-cell lymphoma 2. Hesperidin absorbed wavelengths of light within the UVB range. In summary, hesperidin shielded human keratinocytes from UVB radiation-induced damage and apoptosis via its antioxidant and UVB absorption properties. PMID:26797112

  16. 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

  17. Autophagy regulates chlorpyrifos-induced apoptosis in SH-SY5Y cells

    SciTech Connect

    Park, Jae Hyeon; Lee, Jeong Eun; Shin, In Chul; Koh, Hyun Chul

    2013-04-01

    Recent studies have shown that up-regulation of autophagy may be a tractable therapeutic intervention for clearing disease-causing proteins, including α-synuclein, ubiquitin, and other misfolded or aggregated proteins in pesticide-induced neurodegeneration. In a previous study, we reported that chlorpyrifos (CPF)-induced mitochondria-dependent apoptosis is mediated through reactive oxygen species in SH-SY5Y cells. In this study, we explored a novel pharmacotherapeutic approach to prevent CPF neurotoxicity involving the regulation of autophagy. We investigated the modulation of CPF-induced apoptosis according to autophagy regulation. We found that CPF induced apoptosis in SH-SY5Y cells, as demonstrated by the activation of caspase-3 and nuclear condensation. In addition, we observed that cells treated with CPF underwent autophagic cell death by monitoring the expression of LC3-II and p62. Pretreatment with the autophagy inducer rapamycin significantly enhanced the cell viability of CPF-exposed cells, and the enhancement of cell viability was partially due to alleviation of CPF-induced apoptosis via a decrease in levels of cleaved caspase-3. Specifically, rapamycin pretreatment decreased Bax and increased Bcl-2 expression in mitochondria. In addition, rapamycin significantly decreased cytochrome c release in from mitochondria into the cytosol. However, pretreatment of cells with the autophagy inhibitor, 3-methyladenine (3MA), remarkably increased CPF toxicity in these cells; this with correlated with increased expression of Bax and decreased expression of Bcl-2 in mitochondria. Our results suggest that CPF-induced cytotoxicity is modified by autophagy regulation and that rapamycin protects against CPF-induced apoptosis by enhancing autophagy. Pharmacologic induction of autophagy by rapamycin may be a useful treatment strategy in neurodegenerative disorders. - Highlights: ► Chlorpyrifos (CPF) is cytotoxic to SH-SY5Y cells ► CPF-induced cytotoxicity is mediated by

  18. IGFBP-3 mediates p53-induced apoptosis during serum starvation.

    PubMed

    Grimberg, Adda; Liu, Bingrong; Bannerman, Peter; El-Deiry, Wafik S; Cohen, Pinchas

    2002-08-01

    Insulin-like growth factor binding protein (IGFBP)-3, a p53-response gene, can induce apoptosis in an IGF-independent manner. Here we demonstrate that IGFBP-3 mediates p53-induced apoptosis during serum starvation using two foil neoplastic cell models: one which introduces p53 activity and one which eliminates it. We created a doxycycline-inducible p53 model from the p53-negative PC-3 prostate cancer cell line. Doxycycline treatment increased both p53 and IGFBP-3 levels. It also augmented apoptosis, but not during insulin-like growth factor-I co-treatment. In a second model, lung carcinoma H460 cells expressing fully functional p53 were stably transfected with E6, which targets p53 for degradation. H460-E6 cells contained less p53 and IGFBP-3 than control neo-transfected cells, and proteasome blockade restored both. In serum deprivation, H460-E6 cells had enhanced growth and less apoptosis than did H460-neo cells. Reductions in H460-neo apoptosis, comparable in magnitude to H460-E6, were achieved by adding anti-IGFBP-3-antibody or IGFBP-3 antisense oligomers, but not non-specific immunoglobulin or IGFBP-3 sense oligomers. In summary, turning p53 in two foil neoplastic cell models induced IGFBP-3 expression and increased apoptosis during serum starvation, an effect inhibited by insulin-like growth factor-I treatment and specific IGFBP-3 blockade. This is the first demonstration of inhibition of p53 action by antagonizing IGFBP-3.

  19. Role of Ca2+ signaling in initiation of stretch-induced apoptosis in neonatal heart cells.

    PubMed

    Liao, Xu Dong; Tang, Ai Hui; Chen, Quan; Jin, Hai Jing; Wu, Cai Hong; Chen, Lan-Ying; Wang, Shi Qiang

    2003-10-17

    Abnormal mechanical load, as seen in hypertension, is found to induce heart cell apoptosis, yet the signaling link between cell stretch and apoptotic pathways is not known. Using an in vitro stretch model mimicking diastolic pressure stress, here we show that Ca(2+) signaling participates essentially in the early stage of stretch-induced apoptosis. In neonatal rat cardiomyocytes, the moderate 20% stretch resulted in tonic elevation of intracellular free Ca(2+) ([Ca(2+)](i)). Buffering [Ca(2+)](i) by EGTA-AM, suppressing ryanodine-sensitive Ca(2+) release, and blocking L-type Ca(2+) channels all prevented the stretch-induced apoptosis as assessed by phosphatidylserine exposure and nuclear fragmentation. Notably, Ca(2+) suppression also prevented known stretch-activated apoptotic events, including caspase-3/-9 activation, mitochondrial membrane potential corruption, and reactive oxygen species production, suggesting that Ca(2+) signaling is the upstream of these events. Since [Ca(2+)](i) did not change without activating mechanosensitive Ca(2+) entry, we conclude that stretch-induced Ca(2+) entry, via the Ca(2+)-induced Ca(2+) release mechanism, plays an important role in initiating apoptotic signaling during mechanical stress.

  20. 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

  1. The mechanism of epipodophyllotoxin-induced thymocyte apoptosis: possible role of a novel Ca(2+)-independent protein kinase.

    PubMed

    Ye, X; Georgoff, I; Fleisher, S; Coffman, F D; Cohen, S; Fresa, K L

    1993-10-15

    The epipodophyllotoxins, etoposide (VP-16) and teniposide (VM-26), inhibit topoisomerase II activity by stabilization of the cleavable complex between the enzyme and DNA and formation of protein-bound double-stranded DNA breaks. While it is thought that these agents are cytotoxic by preventing cells from completing the S phase or undergoing mitosis, recent evidence suggests that these agents are also potent inducers of programmed cell death or apoptosis in both normal and malignant cells. We have examined the intracellular pathway leading to epipodophyllotoxin-induced apoptosis in normal mouse thymocytes. Epipodophyllotoxin-induced apoptosis may proceed via a mechanism that is independent of inhibition of topoisomerase activity per se because novobiocin and coumermycin, which inhibit the ATPase subunit of topoisomerase II, were relatively inefficient inducers of apoptosis in these cells, under conditions where strong apoptosis by the epipodophyllotoxins and dexamethasone could be observed. In addition, camptothecin, which inhibits topoisomerase I by stabilization of the cleavable complex between that enzyme and DNA, was also a poor inducer of apoptosis in these cells. Our data suggest that epipodophyllotoxin-induced mouse thymocyte apoptosis, like that induced by dexamethasone, proceeds via a mechanism that involves protein kinase C (PKC) or a similar enzyme. Apoptosis induced by VM-26 or by dexamethasone was inhibited by 1-(5-isoquinolinylsulfonyl)-2- methylpiperazine dihydrochloride (H7), an inhibitor of both PKC and cAMP-dependent protein kinases, but was relatively unaffected by N-(2-guanidinoethyl)-5-isoquinolinesulfonamide (HA1004), a more specific inhibitor of cAMP-dependent protein kinases. A more specific inhibitor of PKC, sangivamycin, also inhibited both VM-26-induced and dexamethasone-induced apoptosis. Both VM-26- and dexamethasone-induced apoptosis were unaffected by EGTA, a calcium (Ca2+) chelator, under conditions that inhibited apoptosis induced by

  2. Acitretin induces apoptosis through CD95 signalling pathway in human cutaneous squamous cell carcinoma cell line SCL-1

    PubMed Central

    Lin, Xiu-Ying; He, Chun-Di; Xiao, Ting; Jin, Xin; Chen, Jiang; Wang, Ya-Kun; Liu, Mei; Wang, Kai-Bo; Jiang, Yi; Wei, Hua-Chen; Chen, Hong-Duo

    2009-01-01

    Skin cancers are by far the most common human malignancies. Retinoids have shown promising preventive and therapeutic effects against a variety of human malignancies. The aim of this study was to investigate the apoptosis-inducing effect of acitretin on human skin squamous cell carcinoma (SCC) SCL-1 cells. We found that acitretin preferentially inhibited the growth of SCL-1 cells in a dose- and time-dependent manner, but not of non-malignant keratinocyte HaCaT cells. This inhibition appeared to be due to induction of apoptosis as revealed by enzyme-linked immunosorbent assay. AnnexinV/propidium iodide assay and morphological observation confirmed the pro-apoptotic effect of acitretin on SCL-1 cells. We further demonstrated that apoptosis was induced within 1–2 days and involved activation of caspases-8, -9, -3 and poly (ADP-ribose) polymerase (PARP). Caspase-8 inhibitor effectively suppressed acitretin-induced apoptosis whereas caspase-9 inhibitor did not. Acitretin increased the levels of CD95 (Fas), CD95-ligand and Fas-associated death domain. Neutralizing ZB4 anti-Fas antibody significantly inhibited the apoptosis in SCL-1 cells induced by acitretin. These results suggest that acitretin is able to induce apoptosis in skin cancer cells possibly via death receptor CD95 apoptosis pathway without affecting the viability of normal keratinocyte. PMID:18624760

  3. Simultaneous deletion of Bax and Bak is required to prevent apoptosis and interstitial fibrosis in obstructive nephropathy

    PubMed Central

    Jang, Hee-Seong

    2015-01-01

    Proximal tubular injury and apoptosis are key mediators of the development of kidney fibrosis, a hallmark of chronic kidney disease. However, the molecular mechanism by which tubular apoptotic cell death leads to kidney fibrosis is poorly understood. In the present study, we tested the roles of Bcl-2-associated X (Bax) and Bcl-2 antagonist/killer (Bak), two crucial proteins involved in intrinsic apoptotic cell death, in the progression of kidney fibrosis. Mice with proximal tubule-specific Bax deletion, systemic deletion of Bak, and dual deletion of Bax and Bak were subjected to unilateral ureteral obstruction (UUO). Dual deficiency of Bax and Bak inhibited tubular apoptosis and atrophy. Consistent with decreased tubular injury, dual ablation of Bax and Bak suppressed UUO-induced inflammation and kidney fibrosis with decreased tubular cell cycle arrest, expression of fibrogenic and inflammatory cytokines, and oxidative stress in the kidney. Bax or Bak deficiency was insufficient to prevent apoptosis and all other aforementioned malevolent effects, suggesting compensatory mediation by each other in the respective signaling pathways. These data suggest that dual ablation of Bax and Bak in the kidney is required to prevent UUO-induced tubular apoptosis and the consequent kidney inflammation and fibrosis. PMID:26180237

  4. Glutamate-mediated protection of crayfish glial cells from PDT-induced apoptosis

    NASA Astrophysics Data System (ADS)

    Rudkovskii, M. V.; Romanenko, N. P.; Berezhnaya, E. V.; Kovaleva, V. D.; Uzdensky, A. B.

    2010-10-01

    Photodynamic treatment that causes intense oxidative stress and kills cells is currently used in neurooncology. However, along with tumor it damages surrounding healthy neurons and glial cells. In order to study the possible role of glutamate-related signaling pathways in photodynamic injury of neurons and glia, we investigated photodynamic effect of alumophthalocyanine Photosens on isolated crayfish stretch receptor that consists of a single neuron surrounded by glial cells. The laser diode (670 nm, 0.4 W/cm2) was used for dye photoexcitation. Application of glutamate increased photodynamically induced necrosis of neurons and glial cells but significantly decreased glial apoptosis. The natural neuroglial mediator N-acetylaspartylglutamate, which releases glutamate after cleavage in the extracellular space by glutamate carboxypeptidase II, also inhibited photoinduced apoptosis. Inhibition of glutamate carboxypeptidase II, oppositely, enhanced apoptosis of glial cells. These data confirm the anti-apoptotic activity of glutamate. Application of NMDA or inhibition of NMDA receptors by MK801 did not influence photodynamic death of neurons and glial cells that indicated nonparticipation of NMDA receptors in these processes. Inhibition of metabotropic glutamate receptors by AP-3 decreased PDT-induced apoptosis. One can suggest that crayfish neurons naturally secrete NAAG, which being cleaved by GCOP produces glutamate. Glutamate prevents photoinduced apoptosis of glial cells possibly through metabotropic but not ionotropic glutamate receptors.

  5. Glutamate-mediated protection of crayfish glial cells from PDT-induced apoptosis

    NASA Astrophysics Data System (ADS)

    Rudkovskii, M. V.; Romanenko, N. P.; Berezhnaya, E. V.; Kovaleva, V. D.; Uzdensky, A. B.

    2011-03-01

    Photodynamic treatment that causes intense oxidative stress and kills cells is currently used in neurooncology. However, along with tumor it damages surrounding healthy neurons and glial cells. In order to study the possible role of glutamate-related signaling pathways in photodynamic injury of neurons and glia, we investigated photodynamic effect of alumophthalocyanine Photosens on isolated crayfish stretch receptor that consists of a single neuron surrounded by glial cells. The laser diode (670 nm, 0.4 W/cm2) was used for dye photoexcitation. Application of glutamate increased photodynamically induced necrosis of neurons and glial cells but significantly decreased glial apoptosis. The natural neuroglial mediator N-acetylaspartylglutamate, which releases glutamate after cleavage in the extracellular space by glutamate carboxypeptidase II, also inhibited photoinduced apoptosis. Inhibition of glutamate carboxypeptidase II, oppositely, enhanced apoptosis of glial cells. These data confirm the anti-apoptotic activity of glutamate. Application of NMDA or inhibition of NMDA receptors by MK801 did not influence photodynamic death of neurons and glial cells that indicated nonparticipation of NMDA receptors in these processes. Inhibition of metabotropic glutamate receptors by AP-3 decreased PDT-induced apoptosis. One can suggest that crayfish neurons naturally secrete NAAG, which being cleaved by GCOP produces glutamate. Glutamate prevents photoinduced apoptosis of glial cells possibly through metabotropic but not ionotropic glutamate receptors.

  6. TRAIL-expressing T cells induce apoptosis of vascular smooth muscle cells in the atherosclerotic plaque

    PubMed Central

    Sato, Kayoko; Niessner, Alexander; Kopecky, Stephen L.; Frye, Robert L.; Goronzy, Jörg J.; Weyand, Cornelia M.

    2006-01-01

    Acute coronary syndromes (ACS) are precipitated by a rupture of the atherosclerotic plaque, often at the site of T cell and macrophage infiltration. Here, we show that plaque-infiltrating CD4 T cells effectively kill vascular smooth muscle cells (VSMC). VSMCs sensitive to T cell–mediated killing express the death receptor DR5 (TNF-related apoptosis-inducing ligand [TRAIL] receptor 2), and anti-TRAIL and anti-DR5 antibodies block T cell–mediated apoptosis. CD4 T cells that express TRAIL upon stimulation are expanded in patients with ACS and more effectively induce VSMC apoptosis. Adoptive transfer of plaque-derived CD4 T cells into immunodeficient mice that are engrafted with human atherosclerotic plaque results in apoptosis of VSMCs, which was prevented by coadministration of anti-TRAIL antibody. These data identify that the death pathway is triggered by TRAIL-producing CD4 T cells as a direct mechanism of VSMC apoptosis, a process which may lead to plaque destabilization. PMID:16418392

  7. Melissa Officinalis L. Extracts Protect Human Retinal Pigment Epithelial Cells against Oxidative Stress-Induced Apoptosis

    PubMed Central

    Jeung, In Cheul; Jee, Donghyun; Rho, Chang-Rae; Kang, Seungbum

    2016-01-01

    Background: We evaluated the protective effect of ALS-L1023, an extract of Melissa officinalis L. (Labiatae; lemon balm) against oxidative stress-induced apoptosis in human retinal pigment epithelial cells (ARPE-19 cells). Methods: ARPE-19 cells were incubated with ALS-L1023 for 24 h and then treated with hydrogen peroxide (H2O2). Oxidative stress-induced apoptosis and intracellular generation of reactive oxygen species (ROS) were assessed by flow cytometry. Caspase-3/7 activation and cleaved poly ADP-ribose polymerase (PARP) were measured to investigate the protective role of ALS-L1023 against apoptosis. The protective effect of ALS-L1023 against oxidative stress through activation of the phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) was evaluated by Western blot analysis. Results: ALS-L1023 clearly reduced H2O2-induced cell apoptosis and intracellular production of ROS. H2O2-induced oxidative stress increased caspase-3/7 activity and apoptotic PARP cleavage, which were significantly inhibited by ALS-L1023. Activation of the PI3K/Akt pathway was associated with the protective effect of ALS-L1023 on ARPE-19 cells. Conclusions: ALS-L1023 protected human RPE cells against oxidative damage. This suggests that ALS-L1023 has therapeutic potential for the prevention of dry age-related macular degeneration. PMID:26941573

  8. Sapodilla Plum (Achras sapota) Induces Apoptosis in Cancer Cell Lines and Inhibits Tumor Progression in Mice

    PubMed Central

    Srivastava, Mrinal; Hegde, Mahesh; Chiruvella, Kishore K.; Koroth, Jinsha; Bhattacharya, Souvari; Choudhary, Bibha; Raghavan, Sathees C.

    2014-01-01

    Intake of fruits rich in antioxidants in daily diet is suggested to be cancer preventive. Sapota is a tropical fruit grown and consumed extensively in several countries including India and Mexico. Here we show that methanolic extracts of Sapota fruit (MESF) induces cytotoxicity in a dose-dependent manner in cancer cell lines. Cell cycle analysis suggested activation of apoptosis, without arresting cell cycle progression. Annexin V-propidium iodide double-staining demonstrated that Sapota fruit extracts potentiate apoptosis rather than necrosis in cancer cells. Loss of mitochondrial membrane potential, upregulation of proapoptotic proteins, activation of MCL-1, PARP-1, and Caspase 9 suggest that MESF treatment leads to activation of mitochondrial pathway of apoptosis. More importantly, we show that MESF treatment leads to significant inhibition of tumor growth and a 3-fold increase in the life span of tumor bearing animals compared to untreated tumor mice. PMID:25142835

  9. Quercetin induces HepG2 cell apoptosis by inhibiting fatty acid biosynthesis

    PubMed Central

    ZHAO, PENG; MAO, JUN-MIN; ZHANG, SHU-YUN; ZHOU, ZE-QUAN; TAN, YANG; ZHANG, YU

    2014-01-01

    Quercetin can inhibit the growth of cancer cells with the ability to act as a ‘chemopreventer’. Its cancer-preventive effect has been attributed to various mechanisms, including the induction of cell-cycle arrest and/or apoptosis, as well as its antioxidant functions. Quercetin can also reduce adipogenesis. Previous studies have shown that quercetin has potent inhibitory effects on animal fatty acid synthase (FASN). In the present study, activity of quercetin was evaluated in human liver cancer HepG2 cells. Intracellular FASN activity was calculated by measuring the absorption of NADPH via a spectrophotometer. MTT assay was used to test the cell viability, immunoblot analysis was performed to detect FASN expression levels and the apoptotic effect was detected by Hoechst 33258 staining. In the present study, it was found that quercetin could induce apoptosis in human liver cancer HepG2 cells with overexpression of FASN. This apoptosis was accompanied by the reduction of intracellular FASN activity and could be rescued by 25 or 50 μM exogenous palmitic acids, the final product of FASN-catalyzed synthesis. These results suggested that the apoptosis induced by quercetin was via the inhibition of FASN. These findings suggested that quercetin may be useful for preventing human liver cancer. PMID:25009654

  10. Propolis augments apoptosis induced by butyrate via targeting cell survival pathways.

    PubMed

    Drago, Eric; Bordonaro, Michael; Lee, Seon; Atamna, Wafa; Lazarova, Darina L

    2013-01-01

    Diet is one of the major lifestyle factors affecting incidence of colorectal cancer (CC), and despite accumulating evidence that numerous diet-derived compounds modulate CC incidence, definitive dietary recommendations are not available. We propose a strategy that could facilitate the design of dietary supplements with CC-preventive properties. Thus, nutrient combinations that are a source of apoptosis-inducers and inhibitors of compensatory cell proliferation pathways (e.g., AKT signaling) may produce high levels of programmed death in CC cells. Here we report the combined effect of butyrate, an apoptosis inducer that is produced through fermentation of fiber in the colon, and propolis, a honeybee product, on CC cells. We established that propolis increases the apoptosis of CC cells exposed to butyrate through suppression of cell survival pathways such as the AKT signaling. The programmed death of CC cells by combined exposure to butyrate and propolis is further augmented by inhibition of the JNK signaling pathway. Analyses on the contribution of the downstream targets of JNK signaling, c-JUN and JAK/STAT, to the apoptosis of butyrate/propolis-treated CC cells ascertained that JAK/STAT signaling has an anti-apoptotic role; whereas, the role of cJUN might be dependent upon regulatory cell factors. Thus, our studies ascertained that propolis augments apoptosis of butyrate-sensitive CC cells and re-sensitizes butyrate-resistant CC cells to apoptosis by suppressing AKT signaling and downregulating the JAK/STAT pathway. Future in vivo studies should evaluate the CC-preventive potential of a dietary supplement that produces high levels of colonic butyrate, propolis, and diet-derived JAK/STAT inhibitors.

  11. Z-ajoene induces apoptosis of HL-60 cells: involvement of Bcl-2 cleavage.

    PubMed

    Li, Min; Min, Ji-Mei; Cui, Jing-Rong; Zhang, Li-He; Wang, Kui; Valette, Annie; Davrinche, Christian; Wright, Michel; Leung-Tack, Jeanne

    2002-01-01

    Garlic organosulfur components exhibit antitumor activity, but the molecular mechanisms underlying these effects have not been well characterized. We showed that Z-ajoene, a sulfur-rich compound purified from garlic, induced time- and dose-dependent apoptosis in HL-60 cells. This process implied the activation of caspase-3 and the cleavage of the antiapoptotic protein Bcl-2. The caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp-[OMe]-fluoromethylketone inhibited Bcl-2 cleavage and apoptosis induced by Z-ajoene. This effect was partially prevented by treatment of HL-60 cells with the antioxidant N-acetylcysteine. Hence, the transmission of apoptotic signal induced by Z-ajoene involved a reactive oxygen species-dependent pathway leading to caspase-dependent Bcl-2 cleavage.

  12. Resveratrol attenuates methylglyoxal-induced mitochondrial dysfunction and apoptosis by Sestrin2 induction

    SciTech Connect

    Seo, Kyuhwa; Seo, Suho; Han, Jae Yun; Ki, Sung Hwan; Shin, Sang Mi

    2014-10-15

    Methylglyoxal is found in high levels in the blood and other tissues of diabetic patients and exerts deleterious effects on cells and tissues. Previously, we reported that resveratrol, a polyphenol in grapes, induced the expression of Sestrin2 (SESN2), a novel antioxidant protein, and inhibited hepatic lipogenesis. This study investigated whether resveratrol protects cells from the methylglyoxal-induced toxicity via SESN2 induction. Methylglyoxal significantly induced cell death in HepG2 cells. However, cells pretreated with resveratrol were rescued from methylglyoxal-induced apoptosis. Resveratrol attenuated glutathione (GSH) depletion and ROS production promoted by methylglyoxal. Moreover, mitochondrial damage was observed by methylglyoxal treatment, but resveratrol restored mitochondrial function, as evidenced by the observed lack of mitochondrial permeability transition and increased ADP/ATP ratio. Resveratrol treatment inhibited SESN2 depletion elicited by methylglyoxal. SESN2 overexpression repressed methylglyoxal-induced mitochondrial dysfunction and apoptosis. Likewise, rotenone-induced cytotoxicity was not observed in SESN2 overexpressed cells. Furthermore, siRNA knockdown of SESN2 reduced the ability of resveratrol to prevent methylglyoxal-induced mitochondrial permeability transition. In addition, when mice were exposed to methylglyoxal after infection of Ad-SESN2, the plasma levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and GSH depletion by methylglyoxal in liver was reduced in Ad-SESN2 infected mice. Our results demonstrated that resveratrol is capable of protecting cells from methylglyoxal-induced mitochondrial dysfunction and oxidative stress via SESN2 induction. - Highlights: • Resveratrol decreased methylglyoxal-induced apoptosis. • Resveratrol attenuated GSH depletion and ROS production promoted by methylglyoxal. • Resveratrol restored the mitochondrial function by Sestrin2 induction. • Induction of Sestrin2

  13. 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

  14. Emodin ameliorates cisplatin-induced apoptosis of rat renal tubular cells in vitro by activating autophagy

    PubMed Central

    Liu, Hong; Gu, Liu-bao; Tu, Yue; Hu, Hao; Huang, Yan-ru; Sun, Wei

    2016-01-01

    Aim: A previous report shows that emodin extracted from the Chinese herbs rhubarb and giant knotweed rhizome can ameliorate the anticancer drug cisplatin-induced injury of HEK293 cells. In this study, we investigated whether and how emodin could protect renal tubular epithelial cells against cisplatin-induced nephrotoxicity in vitro. Methods: The viability and apoptosis of normal rat renal tubular epithelial cells (NRK-52E) were detected using formazan assay and flow cytometry analysis, respectively. The expression levels of cleaved caspase-3, autophagy maker LC3 I/II, and AMPK/mTOR signaling pathway-related proteins were measured with Western blot analysis. The changes of morphology and RFP-LC3 fluorescence were observed under microscopy. Results: Cisplatin (10-50 μmol/L) dose-dependently induced cell damage and apoptosis in NRK-52E cells, whereas emodin (10 and 100 μmol/L) significantly ameliorated cisplatin-induced cell damage, apoptosis and caspase-3 cleavage. Emodin dose-dependently increased LC3-II levels and induced RFP-LC3-containing punctate structures in NRK-52E cells. Furthermore, the protective effects of emodin were abolished by bafilomycin A1 (10 nmol/L), and mimicked by rapamycin (100 nmol/L). Moreover, emodin increased the phosphorylation of AMPK and suppressed the phosphorylation of mTOR. The AMPK inhibitor compound C (10 μmol/L) not only abolished emodin-induced autophagy activation, but also emodin-induced anti-apoptotic effects. Conclusion: Emodin ameliorates cisplatin-induced apoptosis of rat renal tubular cells in vitro through modulating the AMPK/mTOR signaling pathways and activating autophagy. Emodin may have therapeutic potential for the prevention of cisplatin-induced nephrotoxicity. PMID:26775661

  15. Evidence for Agrobacterium-induced apoptosis in maize cells.

    PubMed

    Hansen, G

    2000-06-01

    Agrobacterium spp. can genetically transform most dicotyledonous plant cells whereas many monocot species are recalcitrant to Agrobacterium-mediated transformation. One major obstacle is that co-cultivation of Agrobacterium spp. with plant tissues often results in cell death. Report here is that, in maize tissues, this process resembles apoptosis, with characteristic DNA cleavage into oligonucleosomal fragments and morphological changes. Two anti-apoptotic genes from baculovirus, p35 and iap, had the ability to prevent the onset of apoptosis triggered by Agrobacterium spp. in maize tissues. p35 is reported to act as a direct inhibitor of a certain class of proteases (caspase) whereas i.a.p. may act upstream to prevent their activation. This evidence raises the possibility that caspase-like proteases may also be involved in the apoptotic pathway in plant cells.

  16. Panax quinquefolium saponin attenuates cardiomyocyte apoptosis induced by thapsigargin through inhibition of endoplasmic reticulum stress

    PubMed Central

    Liu, Mi; Xue, Mei; Wang, Xiao-Reng; Tao, Tian-Qi; Xu, Fei-Fei; Liu, Xiu-Hua; Shi, Da-Zhuo

    2015-01-01

    Background Endoplasmic reticulum (ER) stress-related apoptosis is involved in the pathophysiology of many cardiovascular diseases, and Panax quinquefolium saponin (PQS) is able to inhibit excessive ER stress-related apoptosis of cardiomyocytes following hypoxia/reoxygenation and myocardial infarction. However, the pathway by which PQS inhibits the ER stress-related apoptosis is not well understood. To further investigate the protective effect of PQS against ER stress-related apoptosis, primary cultured cardiomyocytes were stimulated with thapsigargin (TG), which is widely used to model cellular ER stress, and it could induce apoptotic cell death in sufficient concentration. Methods Primary cultured cardiomyocytes from neonatal rats were exposed to TG (1 µmol/L) treatment for 24 h, following PQS pre-treatment (160 µg/mL) for 24 h or pre-treatment with small interfering RNA directed against protein kinase-like endoplasmic reticulum kinase (Si-PERK) for 6 h. The viability and apoptosis rate of cardiomyocytes were detected by cell counting kit-8 and flow cytometry respectively. ER stress-related protein expression, such as glucose-regulated protein 78 (GRP78), calreticulin, PERK, eukaryotic translation initiation factor 2α (eIF2α), activating transcription factor 4 (ATF4), and C/EBP homologous protein (CHOP) were assayed by western blotting. Results Both PQS pre-treatment and PERK knockdown remarkably inhibited the cardiomyocyte apoptosis induced by TG, increased cell viability, decreased phosphorylation of both PERK and eIF2α, and decreased protein levels of both ATF4 and CHOP. There was no statistically significant difference between PQS pre-treatment and PERK knockdown in the cardioprotective effect. Conclusions Our data indicate that the PERK-eIF2α-ATF4-CHOP pathway of ER stress is involved in the apoptosis induced by TG, and PQS might prevent TG-induced cardiomyocyte apoptosis through a mechanism involving the suppression of this pathway. These findings

  17. 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.

  18. Molecular Mechanisms involved in Farnesol-Induced Apoptosis

    PubMed Central

    Joo, Joung Hyuck; Jetten, Anton M.

    2009-01-01

    The isoprenoid alcohol farnesol is an effective inducer of cell cycle arrest and apoptosis in a variety of carcinoma cell types. In addition, farnesol has been reported to inhibit tumorigenesis in several animal models suggesting that it functions as a chemopreventative and anti-tumor agent in vivo. A number of different biochemical and cellular processes have been implicated in the growth-inhibitory and apoptosis-inducing effects of farnesol. These include regulation of 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase and CTP:phosphocholine cytidylyltransferase α (CCTα), the rate limiting enzymes in the mevalonate pathway and phosphatidylcholine biosynthesis, respectively, and the generation of reactive oxygen species. In some cell types the action of farnesol is mediated through nuclear receptors, including activation of farnesoid X receptor (FXR) and peroxisome proliferator-activated receptors (PPARs). Recent studies have revealed that induction of endoplasmic reticulum (ER) stress and the subsequent activation of the unfolded protein response (UPR) play a critical role in the induction of apoptosis by farnesol in lung carcinoma cells. This induction was found to be dependent on the activation of the MEK1/2-ERK1/2 pathway. In addition, farnesol induces activation of the NF-κB signaling pathway and a number of NF-κB target genes. Optimal activation of NF-κB was reported to depend on the phosphorylation of p65/RelA by the MEK1/2-MSK1 signaling pathway. In a number of cells farnesol-induced apoptosis was found to be linked to activation of the apoptosome. This review provides an overview of the biochemical and cellular processes regulated by farnesol in relationship to its growth-inhibitory, apoptosis-promoting, and anti-tumor effects. PMID:19520495

  19. cAMP Signaling Prevents Podocyte Apoptosis via Activation of Protein Kinase A and Mitochondrial Fusion

    PubMed Central

    Xie, Kewei; Ni, Zhaohui; Yan, Yucheng; Wei, Kai; Chuang, Peter Y.; He, John Cijiang; Gu, Leyi

    2014-01-01

    Our previous in vitro studies suggested that cyclic AMP (cAMP) signaling prevents adriamycin (ADR) and puromycin aminonucleoside (PAN)-induced apoptosis in podocytes. As cAMP is an important second messenger and plays a key role in cell proliferation, differentiation and cytoskeleton formation via protein kinase A (PKA) or exchange protein directly activated by cAMP (Epac) pathways, we sought to determine the role of PKA or Epac signaling in cAMP-mediated protection of podocytes. In the ADR nephrosis model, we found that forskolin, a selective activator of adenylate cyclase, attenuated albuminuria and improved the expression of podocyte marker WT-1. When podocytes were treated with pCPT-cAMP (a selective cAMP/PKA activator), PKA activation was increased in a time-dependent manner and prevented PAN-induced podocyte loss and caspase 3 activation, as well as a reduction in mitochondrial membrane potential. We found that PAN and ADR resulted in a decrease in Mfn1 expression and mitochondrial fission in podocytes. pCPT-cAMP restored Mfn1 expression in puromycin or ADR-treated podocytes and induced Drp1 phosphorylation, as well as mitochondrial fusion. Treating podocytes with arachidonic acid resulted in mitochondrial fission, podocyte loss and cleaved caspase 3 production. Arachidonic acid abolished the protective effects of pCPT-cAMP on PAN-treated podocytes. Mdivi, a mitochondrial division inhibitor, prevented PAN-induced cleaved caspase 3 production in podocytes. We conclude that activation of cAMP alleviated murine podocyte caused by ADR. PKA signaling resulted in mitochondrial fusion in podocytes, which at least partially mediated the effects of cAMP. PMID:24642777

  20. 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.

  1. Protective effects of BMP-7 against tumor necrosis factor α-induced oligodendrocyte apoptosis.

    PubMed

    Wang, Xin; Xu, Jun-Mei; Wang, Ya-Ping; Yang, Lin; Li, Zhi-Jian

    2016-10-01

    Bone morphogenic protein-7 (BMP7) is a multifunctional cytokine with demonstrated neurogenic potential. Oligodendrocytes (OLs) death after spinal cord injury (SCI) contributes to demyelination of spared axons, even leading to a permanent neurological deficit. Therefore, therapeutic approaches to prevent OLs death after SCI should be considered. Since the effects of BMP7 on OLs after injury are largely unknown, we demonstrated the effects of BMP7 on TNF-α-induced OLs apoptosis in vitro. The effects of BMP7 on TNF-α-induced OLs apoptosis were verified by flow cytometry, spectrophotometry and western blotting on primary cultures from spinal cord of postnatal day 1 (P1) to P2 rats. As shown by flow cytometry, apoptosis rate was 25.6% for the control group, 59.0% for the TNF-α group, and 33.5% for the BMP7+TNF-α group; spectrophotometry showed caspase-3 and caspase-8 activity were significantly increased in the TNF-α group than in the control group, and BMP7 could reverse the increase. The involvement of cIAP1 in the protection of BMP7 was determined by western blotting and silencing cIAP1. In summary, our results demonstrated that BMP7 could potently inhibite TNF-α-induced OLs apoptosis and identified the cIAP1 expression level, the activity of caspase-3 and caspase-8 as important mediators of OLs survival after cellular stress and cytokine challenge. PMID:27224662

  2. Interleukin-13 interferes with activation-induced t-cell apoptosis by repressing p53 expression

    PubMed Central

    Yang, Li; Xu, Ling-Zhi; Liu, Zhi-Qiang; Yang, Gui; Geng, Xiao-Rui; Mo, Li-Hua; Liu, Zhi-Gang; Zheng, Peng-Yuan; Yang, Ping-Chang

    2016-01-01

    The etiology and the underlying mechanism of CD4+ T-cell polarization are unclear. This study sought to investigate the mechanism by which interleukin (IL)-13 prevents the activation-induced apoptosis of CD4+ T cells. Here we report that CD4+ T cells expressed IL-13 receptor α2 in the intestine of sensitized mice. IL-13 suppressed both the activation-induced apoptosis of CD4+ T cells and the expression of p53 and FasL. Exposure to recombinant IL-13 inhibited activation-induced cell death (AICD) along with the expression of p53, caspase 3, and tumor necrosis factor-α in CD4+ T cells. Administration of an anti-IL-13 antibody enhanced the effect of specific immunotherapy on allergic inflammation in the mouse intestine, enforced the expression of p53 in intestinal CD4+ T cells, and enhanced the frequency of CD4+ T-cell apoptosis upon challenge with specific antigens. In summary, blocking IL-13 enhances the therapeutic effect of antigen-specific immunotherapy by regulating apoptosis and thereby enforcing AICD in CD4+ T cells. PMID:26189367

  3. 2-Methoxyestradiol induced Bax phosphorylation and apoptosis in human retinoblastoma cells via p38 MAPK activation.

    PubMed

    Min, Hongbo; Ghatnekar, Gautam S; Ghatnekar, Angela V; You, Xiaohong; Bu, Min; Guo, Xinyi; Bu, Shizhong; Shen, Bo; Huang, Qin

    2012-07-01

    Retinoblastoma (Rb) is a common childhood intraocular cancer that affects approximately 300 children each year in the United States alone. 2-Methoxyestradiol (2ME), an endogenous metabolite of 17-β-estradiol that dose not bind to nuclear estrogen receptor, exhibits potent apoptotic activity against rapidly growing tumor cells. Here, we report that 2ME induction of apoptosis was demonstrated by early fragmented DNA after 48 h of incubation with 10 µM 2ME in Rb cell lines. Subsequently, a decrease of proliferation was observed in a time- and dose-dependent manner. Further analysis of the mechanism indicates that p38 kinase plays a critical role in 2ME-induced apoptosis in Y79 cells, even though ERK was also activated by 2ME under the same conditions. Activation of p38 kinase also mediates 2ME induced Bax phosphorylated at Thr(167) after a 6 h treatment of 2ME, which in turn prevents formation of the Bcl-2-Bax heterodimer. Both p38 specific inhibitor, SB 203580, or p38 knockdown by specific siRNA, blocked 2ME induction of Bax phosphorylation. Furthermore, only transiently transfected mutant BaxT167A, but not Bax S163A, inhibited 2ME-induced apoptosis. In summary, our data suggest that 2ME induces apoptosis in human Rb cells by causing phosphorylation of p38 Mitogen-activated protein kinase (MAPK), which appears to be correlated with phosphorlation of Bax. This understanding of 2ME's ability may help develop it as a promising therapeutic candidate by inducing apoptosis in a Rb. PMID:21769948

  4. [Mechanisms of gross saponins of Tribulus terrestris via activating PKCepsilon against myocardial apoptosis induced by oxidative stress].

    PubMed

    Wang, Si-Si; Ji, Ying-Shi; Li, Hong; Yang, Shi-Jie

    2009-02-01

    This study is to observe the effect of gross saponins of Tribulus terrestris (GSTT) on protein kinase Cepsilon (PKCepsilon) and apoptosis-associated protein in the apoptosis of cultured cardiocyte apoptosis induced by hydrogen peroxide (H2O2), and to explore the mechanisms of GSTT against myocardial apoptosis. Primary cardiocytes were isolated and cultured. Myocardial apoptosis was induced by H2O2 and analyzed with flow cytometry. Protein content of phospho-PKCepsilon, Bcl-2, and Bax were detected with Western blotting analysis. Cleaved caspase-3 protein content was determined with immunocytochemical technique. After the pretreatment of 100 mg x L(-1) GSTT, compared with H2O2 group, GSTT could not only decrease the apoptotic percentage in cardiocytes damaged by H2O2 (P < 0.01), but also reduce protein contents of Bax and cleaved caspase-3 (P < 0.01), and increase protein content of phospho-PKCepsilon and Bcl-2 significantly (P < 0.01). PKC inhibitor chelerythrine (Che) could prevent partly the effect of GSTT against myocardial apoptosis (P < 0.05 and P < 0.01). Mechanisms of GSTT against myocardial apoptosis might be associated with inhibition of mitochondrial apoptosis pathway after PKCepsilon activation.

  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. Crocin protects the liver and kidney from patulin-induced apoptosis in vivo.

    PubMed

    Boussabbeh, Manel; Ben Salem, Intidhar; Belguesmi, Faicel; Neffati, Fadwa; Najjar, Mohamed Fadhel; Abid-Essefi, Salwa; Bacha, Hassen

    2016-05-01

    Patulin (PAT) is a mycotoxin mainly produced by Aspergillus, Penicillium, and Bissochlamys. Given the high risk associated with this mycotoxin, its potential effects have been investigated by many studies. It is known to be teratogenic, mutagenic, and genotoxic, and it has been shown to induce damages in several organs in experimental animals. Our aim was to investigate the preventive effect against PAT-induced apoptosis in vivo using natural carotenoid, Crocin (CRO). Mice were divided into six groups: a control group, a "PAT alone" group, a "CRO alone" group, and a "PAT plus CRO" groups (pre-treatment conditions). Our results showed that CRO restored the normal levels of biochemical parameters in the liver and kidney. The analysis of the protein expression in these organs revealed that PAT-induced toxicity promotes the induction of apoptosis via the increase in P53, Bax, and cytochrome C and the decrease in Bcl2 expressions. We also found that PAT triggered caspase 3 activation and DNA fragmentation. However, pre-treatment with CRO demonstrated a reduction in the induction of apoptosis via the regulation of all tested biomarkers demonstrating that CRO is effective in the protection against PAT hazards. This could be relevant, particularly with the emergent demand for natural products which may counteract the detrimental toxic effects and therefore prevents multiple human diseases.

  7. Oxidant-induced apoptosis is mediated by oxidation of the actin-regulatory protein cofilin

    PubMed Central

    Klamt, Fábio; Zdanov, Stéphanie; Levine, Rodney L.; Pariser, Ashley; Zhang, Yaqin; Zhang, Baolin; Yu, Li-Rong; Veenstra, Timothy D.; Shacter, Emily

    2012-01-01

    Physiological oxidants that are generated by activated phagocytes comprise the main source of oxidative stress during inflammation1,2. Oxidants such as taurine chloramine (TnCl) and hydrogen peroxide (H2O2) can damage proteins and induce apoptosis, but the role of specific protein oxidation in this process has not been defined. We found that the actin-binding protein cofilin is a key target of oxidation. When oxidation of this single regulatory protein is prevented, oxidant-induced apoptosis is inhibited. Oxidation of cofilin causes it to lose its affinity for actin and to translocate to the mitochondria, where it induces swelling and cytochrome c release by mediating opening of the permeability transition pore (PTP). This occurs independently of Bax activation and requires both oxidation of cofilin Cys residues and dephosphorylation at Ser 3. Knockdown of endogenous cofilin using targeted siRNA inhibits oxidant-induced apoptosis, which is restored by re-expression of wild-type cofilin but not by cofilin containing Cys to Ala mutations. Exposure of cofilin to TnCl results in intramolecular disulphide bonding and oxidation of Met residues to Met sulphoxide, but only Cys oxidation causes cofilin to induce mitochondrial damage. PMID:19734890

  8. Peroxynitrite-induced thymocyte apoptosis: the role of caspases and poly (ADP-ribose) synthetase (PARS) activation.

    PubMed Central

    Virág, L; Scott, G S; Cuzzocrea, S; Marmer, D; Salzman, A L; Szabó, C

    1998-01-01

    The mechanisms by which immature thymocyte apoptosis is induced during negative selection are poorly defined. Reports demonstrated that cross-linking of T-cell receptor leads to stromal cell activation, expression of inducible nitric oxide synthase (iNOS) and, subsequently, to thymocyte apoptosis. Therefore we examined, whether NO directly or indirectly, through peroxynitrite formation, causes thymocyte apoptosis. Immuno-histochemical detection of nitrotyrosine revealed in vivo peroxynitrite formation in the thymi of naive mice. Nitrotyrosine, the footprint of peroxynitrite, was predominantly found in the corticomedullary junction and the medulla of naive mice. In the thymi of mice deficient in the inducible isoform of nitric oxide synthase, considerably less nitrotyrosine was found. Exposure of thymocytes in vitro to low concentrations (10 microM) of peroxynitrite led to apoptosis, whereas higher concentrations (50 microM) resulted in intense cell death with the characteristics of necrosis. We also investigated the effect of poly (ADP-ribose) synthetase (PARS) inhibition on thymocyte apoptosis. Using the PARS inhibitor 3-aminobenzamide (3-AB), or thymocytes from PARS-deficient animals, we established that PARS determines the fate of thymocyte death. Suppression of cellular ATP levels, and the cellular necrosis in response to peroxynitrite were prevented by PARS inhibition. Therefore, in the absence of PARS, cells are diverted towards the pathway of apoptotic cell death. Similar results were obtained with H2O2 treatment, while apoptosis induced by non-oxidative stimuli such as dexamethasone or anti-FAS antibody was unaffected by PARS inhibition. In conclusion, we propose that peroxynitrite-induced apoptosis may play a role in the process of thymocyte negative selection. Furthermore, we propose that the physiological role of PARS cleavage by apopain during apoptosis may serve as an energy-conserving step, enabling the cell to complete the process of apoptosis

  9. Diarachidonoylphosphoethanolamine induces apoptosis of malignant pleural mesothelioma cells through a Trx/ASK1/p38 MAPK pathway.

    PubMed

    Tsuchiya, Ayako; Kaku, Yoshiko; Nakano, Takashi; Nishizaki, Tomoyuki

    2015-11-01

    1,2-Diarachidonoyl-sn-glycero-3-phosphoethanolamine (DAPE) induces both necrosis/necroptosis and apoptosis of NCI-H28 malignant pleural mesothelioma (MPM) cells. The present study was conducted to understand the mechanism for DAPE-induced apoptosis of NCI-H28 cells. DAPE induced caspase-independent apoptosis of NCI-H28 malignant pleural mesothelioma (MPM) cells, and the effect of DAPE was prevented by antioxidants or an inhibitor of NADPH oxidase (NOX). DAPE generated reactive oxygen species (ROS) and inhibited activity of thioredoxin (Trx) reductase (TrxR). DAPE decreased an association of apoptosis signal-regulating kinase 1 (ASK1) with thioredoxin (Trx), thereby releasing ASK1. DAPE activated p38 mitogen-activated protein kinase (MAPK), which was inhibited by an antioxidant or knocking-down ASK1. In addition, DAPE-induced NCI-H28 cell death was also prevented by knocking-down ASK1. Taken together, the results of the present study indicate that DAPE stimulates NOX-mediated ROS production and suppresses TrxR activity, resulting in the decrease of reduced Trx and the dissociation of ASK1 from a complex with Trx, allowing sequential activation of ASK1 and p38 MAPK, to induce apoptosis of NCI-H28 MPM cells.

  10. Nicotine induces Nme2-mediated apoptosis in mouse testes.

    PubMed

    Gu, Yunqi; Xu, Wangjie; Nie, Dongsheng; Zhang, Dong; Dai, Jingbo; Zhao, Xianglong; Zhang, Meixing; Wang, Zhaoxia; Chen, Zhong; Qiao, Zhongdong

    2016-04-15

    In mouse testes, germ cell apoptosis can be caused by cigarette smoke and lead to declining quality of semen, but the exact molecular mechanisms remain unclear. To evaluate the effects of nicotine exposure on apoptosis during spermatogenesis, we first constructed a nicotine-treated mouse model and detected germ cell apoptosis activity in the testes using the TUNEL method. Then we analyzed the variation of telomere length and telomerase activity by real-time PCR and TRAP-real-time PCR, respectively. Further, we investigated a highly expressed gene, Nme2, in mouse testes after nicotine treatment from our previous results, which has close correlation with the apoptosis activity predicted by bioinformatics. We performed NME2 overexpression in Hela cells to confirm whether telomere length and telomerase activity were regulated by the Nme2 gene. Finally, we examined methylation of CpG islands in the Nme2 promoter with the Bisulfite Sequencing (BSP) method. The results showed that apoptosis had increased significantly, and then telomerase activity became weak. Further, telomere length was shortened in the germ cells among the nicotine-treated group. In Hela cells, both overexpression of the Nme2 gene and nicotine exposure can suppress the activity of telomerase activity and shorten telomere length. BSP results revealed that the Nme2 promoter appeared with low methylation in mouse testes after nicotine treatment. We assume that nicotine-induced apoptosis may be caused by telomerase activity decline, which is inhibited by the up expression of Nme2 because of its hypomethylation in mouse germ cells.

  11. Neuroglobin protects cardiomyocytes against apoptosis and cardiac hypertrophy induced by isoproterenol in rats.

    PubMed

    Liu, Zhen-Fang; Zhang, Xiao; Qiao, Yan-Xiang; Xu, Wan-Qun; Ma, Cheng-Tai; Gu, Hua-Li; Zhou, Xiu-Mei; Shi, Lei; Cui, Chang-Xing; Xia, Di; Chen, Yu-Guo

    2015-01-01

    Neuroglobin (Ngb) is well known as a physiological role in oxygen homeostasis of neurons and perhaps a protective role against hypoxia and oxidative stress. In this study, we found that Ngb is expressed in rat heart tissues and it is related to isoproterenol induced cardiac hypertrophy. Moreover, overexpression or knock-down of Ngb influences the expression of hypertrophic markers ANP and BNP and the ratio of hypertrophic cells in rat H9c2 myoblasts when isoproterenol treatment. The Annexin V-FITC/PI Staining, Western blot and qPCR analysis showed that the involvement in p53-mediated apoptosis of cardiomyocytes of Ngb is might be the mechanism. This protein could prevent the cells against ROS and POS-induced apoptosis not only in nervous systems but also in cardiomyocytes. From the results, it is concluded that Ngb is a promising protectant in the cardiac hypertrophy, it may be a candidate target to cardiac hypertrophy for clinic treatment. PMID:26131111

  12. TIA1 oxidation inhibits stress granule assembly and sensitizes cells to stress-induced apoptosis

    PubMed Central

    Arimoto-Matsuzaki, Kyoko; Saito, Haruo; Takekawa, Mutsuhiro

    2016-01-01

    Cytoplasmic stress granules (SGs) are multimolecular aggregates of stalled translation pre-initiation complexes that prevent the accumulation of misfolded proteins, and that are formed in response to certain types of stress including ER stress. SG formation contributes to cell survival not only by suppressing translation but also by sequestering some apoptosis regulatory factors. Because cells can be exposed to various stresses simultaneously in vivo, the regulation of SG assembly under multiple stress conditions is important but unknown. Here we report that reactive oxygen species (ROS) such as H2O2 oxidize the SG-nucleating protein TIA1, thereby inhibiting SG assembly. Thus, when cells are confronted with a SG-inducing stress such as ER stress caused by protein misfolding, together with ROS-induced oxidative stress, they cannot form SGs, resulting in the promotion of apoptosis. We demonstrate that the suppression of SG formation by oxidative stress may underlie the neuronal cell death seen in neurodegenerative diseases. PMID:26738979

  13. Apoptosis-inducing effects of Melissa officinalis L. essential oil in glioblastoma multiforme cells.

    PubMed

    Queiroz, Rafaela Muniz de; Takiya, Christina Maeda; Guimarães, Lívia Paes Tavares Pacheco; Rocha, Gleice da Graça; Alviano, Daniela Sales; Blank, Arie Fitzgerald; Alviano, Celuta Sales; Gattass, Cerli Rocha

    2014-07-01

    Current therapies for glioblastoma multiforme (GBM) are not effective. This study investigated the activity of the M. officinalis essential oil (EO) and its major component (citral) in GBM cell lines. Both EO and citral decreased the viability and induced apoptosis of GBM cells as demonstrated by DNA fragmentation and caspase-3 activation. Antioxidant prevented citral-induced death, indicating its dependence on the production of reactive oxygen species. Citral downmodulated the activity and inhibited the expression of multidrug resistance associated protein 1 (MRP1). These results show that EO, through its major component, citral, may be of potential interest for the treatment of GBM.

  14. 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

  15. The matricellular protein CCN1 regulates TNF-α induced vascular endothelial cell apoptosis.

    PubMed

    Zhang, Jin; Wu, Gongxiong; Dai, Haibin

    2016-01-01

    Due to the epidemic obesity and associated diabetes, the incidence of atherosclerosis is increasing worldwide. Atherosclerosis is a chronic inflammatory disease characterized by the hardening and narrowing of arteries with plaques that consist of inflammatory cells, dead endothelial cells, lipids, and often hyper proliferated vascular smooth muscle cells. During the development of atherosclerosis, vascular endothelial cell (EC) apoptosis induced by the adipokine tumor necrosis factor alpha (TNF-α), is an early event in the plaque formation. However, TNF-α alone is not sufficient to induce apoptosis of endothelial cells. Recent studies suggested that the matricellular protein CCN family member 1 (CCN1) involves in endothelial cell dysfunction besides its well-known angiogenic function during tissue repair by promoting vascular smooth muscle cells proliferation and migration. Herein, we explored the possibility and mechanism of CCN1 in TNF-α induced endothelial cells apoptosis. Both mRNA and protein levels of CCN1 are found up-regulated in endothelial cells after TNF-α treatment. In addition, overexpression of CCN1 promoted endothelial cell apoptosis in the presence of TNF-α. Furthermore, CCN1 directly up-regulated the expression of TNF-α-target genes, and this up-regulation required the activation of P53 and NF-κB both in vivo and in vitro. Taken together, CNN1 regulates TNF-α induced endothelial cells apoptosis that may underlie poor response to TNF-α therapy and hence may be a better therapeutic target for preventing vascular dysfunction in obesity.

  16. 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

  17. 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.

  18. 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

  19. Pharmacologic preconditioning with berberine attenuating ischemia-induced apoptosis and promoting autophagy in neuron.

    PubMed

    Zhang, Qichun; Bian, Huimin; Guo, Liwei; Zhu, Huaxu

    2016-01-01

    Pharmacologic preconditioning is an intriguing and emerging approach adopted to prevent injury of ischemia/reperfusion. Neuroprotection is the cardinal effect of these pleiotropic actions of berberine. Here we investigated that whether berberine could acts as a preconditioning stimuli contributing to attenuate hypoxia-induced neurons death as well. Male Sprague-Dawley rats of middle cerebral artery occlusion (MCAO) and rat primary cortical neurons undergoing oxygen and glucose deprivation (OGD) were preconditioned with berberine (40 mg/kg, for 24 h in vivo, and 10(-6) mol/L, for 2 h in vitro, respectively). The neurological deficits and cerebral water contents of MCAO rats were evaluated. The autophagy and apoptosis were further determined in primary neurons in vitro. Berberine preconditioning (BP) was then shown to ameliorate the neurological deficits, decrease cerebral water content and promote neurogenesis of MCAO rats. Decreased LDH release from OGD-treated neurons was observed via BP, which was blocked by LY294002 (20 µmol/L), GSK690693 (10 µmol/L), or YC-1 (25 µmol/L). Furthermore, BP stimulated autophagy and inhibited apoptosis via modulated the autophagy-associated proteins LC 3, Beclin-1 and p62, and apoptosis-modulating proteins caspase 3, caspase 8, caspase 9, PARP and BCL-2/Bax. In conclusion, berberine acts as a stimulus of preconditioning that exhibits neuroprotection via promoting autophagy and decreasing anoxia-induced apoptosis. PMID:27158406

  20. Laminarin induces apoptosis of human colon cancer LOVO cells through a mitochondrial pathway.

    PubMed

    Ji, Yu Bin; Ji, Chen Feng; Zhang, He

    2012-08-20

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

  1. Fermented wheat aleurone inhibits growth and induces apoptosis in human HT29 colon adenocarcinoma cells.

    PubMed

    Borowicki, Anke; Stein, Katrin; Scharlau, Daniel; Scheu, Kerstin; Brenner-Weiss, Gerald; Obst, Ursula; Hollmann, Jürgen; Lindhauer, Meinolf; Wachter, Norbert; Glei, Michael

    2010-02-01

    Fermentation of dietary fibre by the gut microflora may enhance levels of SCFA, which are potentially chemoprotective against colon cancer. Functional food containing wheat aleurone may prevent cancer by influencing cell cycle and cell death. We investigated effects of fermented wheat aleurone on growth and apoptosis of HT29 cells. Wheat aleurone, flour and bran were digested and fermented in vitro. The resulting fermentation supernatants (fs) were analysed for their major metabolites (SCFA, bile acids and ammonia). HT29 cells were treated for 24-72 h with the fs or synthetic mixtures mimicking the fs in SCFA, butyrate or deoxycholic acid (DCA) contents, and the influence on cell growth was determined. Fs aleurone was used to investigate the modulation of apoptosis and cell cycle. The fermented wheat samples contained two- to threefold higher amounts of SCFA than the faeces control (blank), but reduced levels of bile acids and increased concentrations of ammonia. Fs aleurone and flour equally reduced cell growth of HT29 more effectively than the corresponding blank and the SCFA mixtures. The EC(50) (48 h) ranged from 10 % (flour) to 19 % (blank). Markedly after 48 h, fs aleurone (10 %) significantly induced apoptosis and inhibited cell proliferation by arresting the cell cycle in the G0/G1 phase. In conclusion, fermentation of wheat aleurone results in a reduced level of tumour-promoting DCA, but higher levels of potentially chemopreventive SCFA. Fermented wheat aleurone is able to induce apoptosis and to block cell cycle - two essential markers of secondary chemoprevention.

  2. Pharmacologic preconditioning with berberine attenuating ischemia-induced apoptosis and promoting autophagy in neuron

    PubMed Central

    Zhang, Qichun; Bian, Huimin; Guo, Liwei; Zhu, Huaxu

    2016-01-01

    Pharmacologic preconditioning is an intriguing and emerging approach adopted to prevent injury of ischemia/reperfusion. Neuroprotection is the cardinal effect of these pleiotropic actions of berberine. Here we investigated that whether berberine could acts as a preconditioning stimuli contributing to attenuate hypoxia-induced neurons death as well. Male Sprague-Dawley rats of middle cerebral artery occlusion (MCAO) and rat primary cortical neurons undergoing oxygen and glucose deprivation (OGD) were preconditioned with berberine (40 mg/kg, for 24 h in vivo, and 10-6 mol/L, for 2 h in vitro, respectively). The neurological deficits and cerebral water contents of MCAO rats were evaluated. The autophagy and apoptosis were further determined in primary neurons in vitro. Berberine preconditioning (BP) was then shown to ameliorate the neurological deficits, decrease cerebral water content and promote neurogenesis of MCAO rats. Decreased LDH release from OGD-treated neurons was observed via BP, which was blocked by LY294002 (20 µmol/L), GSK690693 (10 µmol/L), or YC-1 (25 µmol/L). Furthermore, BP stimulated autophagy and inhibited apoptosis via modulated the autophagy-associated proteins LC 3, Beclin-1 and p62, and apoptosis-modulating proteins caspase 3, caspase 8, caspase 9, PARP and BCL-2/Bax. In conclusion, berberine acts as a stimulus of preconditioning that exhibits neuroprotection via promoting autophagy and decreasing anoxia-induced apoptosis. PMID:27158406

  3. Autophagy mediated CoCrMo particle-induced peri-implant osteolysis by promoting osteoblast apoptosis.

    PubMed

    Wang, Zhenheng; Liu, Naicheng; Liu, Kang; Zhou, Gang; Gan, Jingjing; Wang, Zhenzhen; Shi, Tongguo; He, Wei; Wang, Lintao; Guo, Ting; Bao, Nirong; Wang, Rui; Huang, Zhen; Chen, Jiangning; Dong, Lei; Zhao, Jianning; Zhang, Junfeng

    2015-01-01

    Wear particle-induced osteolysis is the leading cause of aseptic loosening, which is the most common reason for THA (total hip arthroplasty) failure and revision surgery. Although existing studies suggest that osteoblast apoptosis induced by wear debris is involved in aseptic loosening, the underlying mechanism linking wear particles to osteoblast apoptosis remains almost totally unknown. In the present study, we investigated the effect of autophagy on osteoblast apoptosis induced by CoCrMo metal particles (CoPs) in vitro and in a calvarial resorption animal model. Our study demonstrated that CoPs stimulated autophagy in osteoblasts and PIO (particle-induced osteolysis) animal models. Both autophagy inhibitor 3-MA (3-methyladenine) and siRNA of Atg5 could dramatically reduce CoPs-induced apoptosis in osteoblasts. Further, inhibition of autophagy with 3-MA ameliorated the severity of osteolysis in PIO animal models. Moreover, 3-MA also prevented osteoblast apoptosis in an antiautophagic way when tested in PIO model. Collectively, these results suggest that autophagy plays a key role in CoPs-induced osteolysis and that targeting autophagy-related pathways may represent a potential therapeutic approach for treating particle-induced peri-implant osteolysis.

  4. Autophagy mediated CoCrMo particle-induced peri-implant osteolysis by promoting osteoblast apoptosis

    PubMed Central

    Wang, Zhenheng; Liu, Naicheng; Liu, Kang; Zhou, Gang; Gan, Jingjing; Wang, Zhenzhen; Shi, Tongguo; He, Wei; Wang, Lintao; Guo, Ting; Bao, Nirong; Wang, Rui; Huang, Zhen; Chen, Jiangning; Dong, Lei; Zhao, Jianning; Zhang, Junfeng

    2015-01-01

    Wear particle-induced osteolysis is the leading cause of aseptic loosening, which is the most common reason for THA (total hip arthroplasty) failure and revision surgery. Although existing studies suggest that osteoblast apoptosis induced by wear debris is involved in aseptic loosening, the underlying mechanism linking wear particles to osteoblast apoptosis remains almost totally unknown. In the present study, we investigated the effect of autophagy on osteoblast apoptosis induced by CoCrMo metal particles (CoPs) in vitro and in a calvarial resorption animal model. Our study demonstrated that CoPs stimulated autophagy in osteoblasts and PIO (particle-induced osteolysis) animal models. Both autophagy inhibitor 3-MA (3-methyladenine) and siRNA of Atg5 could dramatically reduce CoPs-induced apoptosis in osteoblasts. Further, inhibition of autophagy with 3-MA ameliorated the severity of osteolysis in PIO animal models. Moreover, 3-MA also prevented osteoblast apoptosis in an antiautophagic way when tested in PIO model. Collectively, these results suggest that autophagy plays a key role in CoPs-induced osteolysis and that targeting autophagy-related pathways may represent a potential therapeutic approach for treating particle-induced peri-implant osteolysis. PMID:26566231

  5. Nickel (II)-induced cytotoxicity and apoptosis in human proximal tubule cells through a ROS- and mitochondria-mediated pathway

    SciTech Connect

    Wang, Yi-Fen; Shyu, Huey-Wen; Chang, Yi-Chuang; Tseng, Wei-Chang; Huang, Yeou-Lih; Lin, Kuan-Hua; Chou, Miao-Chen; Liu, Heng-Ling; Chen, Chang-Yu

    2012-03-01

    Nickel compounds are known to be toxic and carcinogenic in kidney and lung. In this present study, we investigated the roles of reactive oxygen species (ROS) and mitochondria in nickel (II) acetate-induced cytotoxicity and apoptosis in the HK-2 human renal cell line. The results showed that the cytotoxic effects of nickel (II) involved significant cell death and DNA damage. Nickel (II) increased the generation of ROS and induced a noticeable reduction of mitochondrial membrane potential (MMP). Analysis of the sub-G1 phase showed a significant increase in apoptosis in HK-2 cells after nickel (II) treatment. Pretreatment with N-acetylcysteine (NAC) not only inhibited nickel (II)-induced cell death and DNA damage, but also significantly prevented nickel (II)-induced loss of MMP and apoptosis. Cell apoptosis triggered by nickel (II) was characterized by the reduced protein expression of Bcl-2 and Bcl-xL and the induced the protein expression of Bad, Bcl-Xs, Bax, cytochrome c and caspases 9, 3 and 6. The regulation of the expression of Bcl-2-family proteins, the release of cytochrome c and the activation of caspases 9, 3 and 6 were inhibited in the presence of NAC. These results suggest that nickel (II) induces cytotoxicity and apoptosis in HK-2 cells via ROS generation and that the mitochondria-mediated apoptotic signaling pathway may be involved in the positive regulation of nickel (II)-induced renal cytotoxicity.

  6. Acetaminophen Induces Apoptosis in Rat Cortical Neurons

    PubMed Central

    Posadas, Inmaculada; Santos, Pablo; Blanco, Almudena; Muñoz-Fernández, Maríangeles; Ceña, Valentín

    2010-01-01

    Background Acetaminophen (AAP) is widely prescribed for treatment of mild pain and fever in western countries. It is generally considered a safe drug and the most frequently reported adverse effect associated with acetaminophen is hepatotoxicity, which generally occurs after acute overdose. During AAP overdose, encephalopathy might develop and contribute to morbidity and mortality. Our hypothesis is that AAP causes direct neuronal toxicity contributing to the general AAP toxicity syndrome. Methodology/Principal Findings We report that AAP causes direct toxicity on rat cortical neurons both in vitro and in vivo as measured by LDH release. We have found that AAP causes concentration-dependent neuronal death in vitro at concentrations (1 and 2 mM) that are reached in human plasma during AAP overdose, and that are also reached in the cerebrospinal fluid of rats for 3 hours following i.p injection of AAP doses (250 and 500 mg/Kg) that are below those required to induce acute hepatic failure in rats. AAP also increases both neuronal cytochrome P450 isoform CYP2E1 enzymatic activity and protein levels as determined by Western blot, leading to neuronal death through mitochondrial–mediated mechanisms that involve cytochrome c release and caspase 3 activation. In addition, in vivo experiments show that i.p. AAP (250 and 500 mg/Kg) injection induces neuronal death in the rat cortex as measured by TUNEL, validating the in vitro data. Conclusions/Significance The data presented here establish, for the first time, a direct neurotoxic action by AAP both in vivo and in vitro in rats at doses below those required to produce hepatotoxicity and suggest that this neurotoxicity might be involved in the general toxic syndrome observed during patient APP overdose and, possibly, also when AAP doses in the upper dosing schedule are used, especially if other risk factors (moderate drinking, fasting, nutritional impairment) are present. PMID:21170329

  7. Prodigiosin-induced apoptosis in human colon cancer cells.

    PubMed

    Montaner, B; Pérez-Tomás, R

    2001-03-16

    Prodigiosin is a red pigment produced by various bacteria including Serratia marcescens. Colorectal cancer is one of the most frequent malignancies and one of the most frequent causes of cancer death in the Western world. Its treatment is far from satisfactory and the challenge to oncologists is to find novel chemical entities with less toxicity and greater effectiveness than those used in current chemotherapy. Here we characterize the apoptotic action of prodigiosin in colon cancer cells. DLD-1 and SW-620 human colon adenocarcinoma cells, NRK and Swiss-3T3 nonmalignant cells were assayed by the MTT assay, fragmentation pattern of DNA, Hoechst 33342 staining and study of PARP cleavage by Western blot, in order to characterize the prodigiosin-induced apoptosis. Prodigiosin was purified and its structure was confirmed. Metastatic SW-620 cells were more sensitive to prodigiosin (IC50: 275 nM) than DLD-1. We did not observe a significant decrease in the viability of NRK cells. We confirmed that prodigiosin induces apoptosis in both cancer cell lines by the characteristic DNA laddering pattern and condensed nuclei or apoptotic bodies identified by fluorescence microscopy. These results indicate that prodigiosin induces apoptosis in colon cancer cells.

  8. 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...

  9. 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.

  10. Zoledronic acid induces apoptosis and autophagy in cervical cancer cells.

    PubMed

    Wang, I-Te; Chou, Shou-Chu; Lin, Ying-Chin

    2014-12-01

    Cervical cancer is one of the most common gynecological cancers in association with high mortality and morbidity. The present study was aimed to investigate the in vitro effects of zoledronic acid (ZA) on viability and induction of apoptosis and autophagy as well as inflammatory effects in three human cervical cancer cell lines (HeLa, SiHa, and CaSki). Cell viability was measured by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay. Induction of apoptosis was determined by quantitation of expression level of B cell lymphoma 2 (Bcl-2) and Bax messenger RNA (mRNA) and identification of the proteolytic cleavage of poly (ADP)-ribose polymerase (PARP) and caspase-3. Autophagic effects were examined by quantitation of mRNA expression of autophagy protein 5 (ATG5) and beclin1 and identifying accumulation of microtubule-associated protein 1 light chain 3 (LC3)-II. Inflammatory effect was determined by measuring expression and production of IL-6 and cyclooxygenase-2 (Cox-2). The results showed ZA significantly inhibited cell viability of cervical cancer cells. ZA-induced cell death displayed features characteristic to both apoptosis and autophagy and was associated with different changes in the levels of Bcl-2 and Bax in the various cervical cancer lines. Expression of metastatic cytokines, IL-6 and Cox-2, was upregulated in the presence of ZA at low concentration. Our data revealed that ZA inhibits cervical cancer cells through the synergistic effect of apoptosis induction and autophagy activation.

  11. Toll-Like Receptor 9 Is Required for Opioid-Induced Microglia Apoptosis

    PubMed Central

    Miao, Junying; Jiang, Yulin; Zhang, Yi; Xiao, Zuoxiang; Hanley, Gregory; Li, Yi; Zhang, Xiumei; LeSage, Gene; Peng, Ying; Yin, Deling

    2011-01-01

    Opioids have been widely applied in clinics as one of the most potent pain relievers for centuries, but their abuse has deleterious physiological effects beyond addiction. However, the underlying mechanism by which microglia in response to opioids remains largely unknown. Here we show that morphine induces the expression of Toll-like receptor 9 (TLR9), a key mediator of innate immunity and inflammation. Interestingly, TLR9 deficiency significantly inhibited morphine-induced apoptosis in microglia. Similar results were obtained when endogenous TLR9 expression was suppressed by the TLR9 inhibitor CpGODN. Inhibition of p38 MAPK by its specific inhibitor SB203580 attenuated morphine-induced microglia apoptosis in wild type microglia. Morphine caused a dramatic decrease in Bcl-2 level but increase in Bax level in wild type microglia, but not in TLR9 deficient microglia. In addition, morphine treatment failed to induce an increased levels of phosphorylated p38 MAPK and MAP kinase kinase 3/6 (MKK3/6), the upstream MAPK kinase of p38 MAPK, in either TLR9 deficient or µ-opioid receptor (µOR) deficient primary microglia, suggesting an involvement of MAPK and µOR in morphine-mediated TLR9 signaling. Moreover, morphine-induced TLR9 expression and microglia apoptosis appears to require μOR. Collectively, these results reveal that opioids prime microglia to undergo apoptosis through TLR9 and µOR as well. Taken together, our data suggest that inhibition of TLR9 and/or blockage of µOR is capable of preventing opioid-induced brain damage. PMID:21559519

  12. Resveratrol attenuates methylglyoxal-induced mitochondrial dysfunction and apoptosis by Sestrin2 induction.

    PubMed

    Seo, Kyuhwa; Seo, Suho; Han, Jae Yun; Ki, Sung Hwan; Shin, Sang Mi

    2014-10-15

    Methylglyoxal is found in high levels in the blood and other tissues of diabetic patients and exerts deleterious effects on cells and tissues. Previously, we reported that resveratrol, a polyphenol in grapes, induced the expression of Sestrin2 (SESN2), a novel antioxidant protein, and inhibited hepatic lipogenesis. This study investigated whether resveratrol protects cells from the methylglyoxal-induced toxicity via SESN2 induction. Methylglyoxal significantly induced cell death in HepG2 cells. However, cells pretreated with resveratrol were rescued from methylglyoxal-induced apoptosis. Resveratrol attenuated glutathione (GSH) depletion and ROS production promoted by methylglyoxal. Moreover, mitochondrial damage was observed by methylglyoxal treatment, but resveratrol restored mitochondrial function, as evidenced by the observed lack of mitochondrial permeability transition and increased ADP/ATP ratio. Resveratrol treatment inhibited SESN2 depletion elicited by methylglyoxal. SESN2 overexpression repressed methylglyoxal-induced mitochondrial dysfunction and apoptosis. Likewise, rotenone-induced cytotoxicity was not observed in SESN2 overexpressed cells. Furthermore, siRNA knockdown of SESN2 reduced the ability of resveratrol to prevent methylglyoxal-induced mitochondrial permeability transition. In addition, when mice were exposed to methylglyoxal after infection of Ad-SESN2, the plasma levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and GSH depletion by methylglyoxal in liver was reduced in Ad-SESN2 infected mice. Our results demonstrated that resveratrol is capable of protecting cells from methylglyoxal-induced mitochondrial dysfunction and oxidative stress via SESN2 induction. PMID:25151220

  13. Enhancement of radiation-induced apoptosis by Podophyllum hexandrum.

    PubMed

    Prem Kumar, I; Rana, S V S; Samanta, N; Goel, H C

    2003-09-01

    The aqueous extract of Podophyllum hexandrum (RP-1), which has been recently reported to manifest radioprotective and anti-tumour properties, has been investigated for its mode of action. RP-1, under in-vitro conditions dose-dependently chelated metal ions, inhibited radiation or metal ion-induced hydroxyl radicals and lipid peroxidation and scavenged superoxide anions. Intraperitoneal administration of RP-1 to mice pre-irradiation (10 Gy) induced more DNA fragmentation and lipid peroxidation in thymocytes maximally at 4 and 8 h, respectively, in comparison with RP-1 treatment or irradiation. Flow-cytometric quantification of sub-diploid peak, oligonucleosomal cleavage assay (ladder) and depletion of total thiols also corroborated the ability of RP-1 to enhance radiation-induced apoptosis. RP-1 in presence of 100 microM CuSO(4) induced strand breaks in plasmid DNA and addition of metal chelators (EDTA and deferoxamine) inhibited the strand scission. Treatment with a major constituent of RP-1, podophyllin, did not cause strand breaks, but isolated constituents of RP-1, quercetin or podophyllotoxin, induced strand breaks. Depending on its concentration in the milieu, RP-1 acted as a pro- or antioxidant modifying the radiation-induced apoptosis and therefore could be exploited for cancer management.

  14. Magnesium induces neuronal apoptosis by suppressing excitability

    PubMed Central

    Dribben, W H; Eisenman, L N; Mennerick, S

    2010-01-01

    In clinical obstetrics, magnesium sulfate (MgSO4) use is widespread, but effects on brain development are unknown. Many agents that depress neuronal excitability increase developmental neuroapoptosis. In this study, we used dissociated cultures of rodent hippocampus to examine the effects of Mg++ on excitability and survival. Mg++-induced caspase-3-associated cell loss at clinically relevant concentrations. Whole-cell patch-clamp techniques measured Mg++ effects on action potential threshold, action potential peak amplitude, spike number and changes in resting membrane potential. Mg++ depolarized action potential threshold, presumably from surface charge screening effects on voltage-gated sodium channels. Mg++ also decreased the number of action potentials in response to fixed current injection without affecting action potential peak amplitude. Surprisingly, Mg++ also depolarized neuronal resting potential in a concentration-dependent manner with a +5.2 mV shift at 10 mM. Voltage ramps suggested that Mg++ blocked a potassium conductance contributing to the resting potential. In spite of this depolarizing effect of Mg++, the net inhibitory effect of Mg++ nearly completely silenced neuronal network activity measured with multielectrode array recordings. We conclude that although Mg++ has complex effects on cellular excitability, the overall inhibitory influence of Mg++ decreases neuronal survival. Taken together with recent in vivo evidence, our results suggest that caution may be warranted in the use of Mg++ in clinical obstetrics and neonatology. PMID:21364668

  15. Role of autophagy in cadmium-induced apoptosis of primary rat osteoblasts

    PubMed Central

    Liu, Wei; Dai, Nannan; Wang, Yi; Xu, Chao; Zhao, Hongyan; Xia, Pengpeng; Gu, Jianhong; Liu, Xuezhong; Bian, Jianchun; Yuan, Yan; Zhu, Jiaqiao; Liu, Zongping

    2016-01-01

    Cadmium (Cd) is a common environmental pollutant that can damage many organs and the fetus. We previously reported that Cd induced apoptosis in primary rat osteoblasts (OBs). OB apoptosis induced by Cd will eventually lead to osteoporosis. In this study, a novel pharmacotherapeutic approach was investigated involving the regulation of autophagy to prevent Cd osteoporosis. The results showed that Cd treatment induced apoptosis in OBs, as demonstrated by the ratio of Bax/Bcl-2, activation of poly (ADP-ribose) polymerase (PARP) and nuclear condensation. In addition, cells treated with Cd were observed to undergo autophagic cell death by monitoring the induction of the beclin 1, autophagy gene 5 (Atg5) and the expression of microtubule-associated protein 1 light chain 3 (LC3). The results indicated that promotion of apoptotic cell death by Cd is accompanied by induction of autophagy in OBs. Interestingly, Cd-mediated apoptotic cell death was suppressed by pretreatment with the autophagy activator rapamycin (RAP) and potentiated by the autophagy inhibitor chloroquine (CQ) or small interfering RNA against beclin 1. These findings suggest that the autophagic response plays a protective role that impedes eventual cell death. Activation of autophagy could therefore be an adjunctive strategy for treatment of Cd-induced osteoporosis. PMID:26852917

  16. Auranofin induces apoptosis and necrosis in HeLa cells via oxidative stress and glutathione depletion.

    PubMed

    You, Bo Ra; Shin, Hye Rim; Han, Bo Ram; Kim, Suhn Hee; Park, Woo Hyun

    2015-02-01

    Auranofin (Au), an inhibitor of thioredoxin reductase, is a known anti‑cancer drug. In the present study, the anti‑growth effect of Au on HeLa cervical cancer cells was examined in association with levels of reactive oxygen species (ROS) and glutathione (GSH). Au inhibited the growth of HeLa cells with an IC50 of ~2 µM at 24 h. This agent induced apoptosis and necrosis, accompanied by the cleavage of poly (ADP‑ribose) polymerase and loss of mitochondrial membrane potential. The pan‑caspase inhibitor, benzyloxycarbonyl‑Val‑Ala‑Asp‑fluoromethylketone, prevented apoptotic cell death and each of the assessed caspase inhibitors inhibited necrotic cell death induced by Au. With respect to the levels of ROS and GSH, Au increased intracellular O2•- in the HeLa cells and induced GSH depletion. The pan‑caspase inhibitor reduced the levels of O2•- and GSH depletion in Au‑treated HeLa cells. The antioxidant, N‑acetyl cysteine, not only attenuated apoptosis and necrosis in the Au‑treated HeLa cells, but also decreased the levels of O2•- and GSH depletion in the cells. By contrast, L‑buthionine sulfoximine, a GSH synthesis inhibitor, intensified cell death O2•- and GSH depletion in the Au‑treated HeLa cells. In conclusion, Au induced apoptosis and necrosis in HeLa cells via the induction of oxidative stress and the depletion of GSH.

  17. Berberine-induced apoptosis in human prostate cancer cells is initiated by reactive oxygen species generation

    SciTech Connect

    Meeran, Syed M.; Katiyar, Suchitra; Katiyar, Santosh K.

    2008-05-15

    Phytochemicals show promise as potential chemopreventive or chemotherapeutic agents against various cancers. Here we report the chemotherapeutic effects of berberine, a phytochemical, on human prostate cancer cells. The treatment of human prostate cancer cells (PC-3) with berberine induced dose-dependent apoptosis but this effect of berberine was not seen in non-neoplastic human prostate epithelial cells (PWR-1E). Berberine-induced apoptosis was associated with the disruption of the mitochondrial membrane potential, release of apoptogenic molecules (cytochrome c and Smac/DIABLO) from mitochondria and cleavage of caspase-9,-3 and PARP proteins. This effect of berberine on prostate cancer cells was initiated by the generation of reactive oxygen species (ROS) irrespective of their androgen responsiveness, and the generation of ROS was through the increased induction of xanthine oxidase. Treatment of cells with allopurinol, an inhibitor of xanthine oxidase, inhibited berberine-induced oxidative stress in cancer cells. Berberine-induced apoptosis was blocked in the presence of antioxidant, N-acetylcysteine, through the prevention of disruption of mitochondrial membrane potential and subsequently release of cytochrome c and Smac/DIABLO. In conclusion, the present study reveals that the berberine-mediated cell death of human prostate cancer cells is regulated by reactive oxygen species, and therefore suggests that berberine may be considered for further studies as a promising therapeutic candidate for prostate cancer.

  18. Copper compound induces autophagy and apoptosis of glioma cells by reactive oxygen species and jnk activation

    PubMed Central

    2012-01-01

    Background Glioblastoma multiforme (GBM) is the most aggressive of the primary brain tumors, with a grim prognosis despite intensive treatment. In the past decades, progress in research has not significantly increased overall survival rate. Methods The in vitro antineoplastic effect and mechanism of action of Casiopeina III-ia (Cas III-ia), a copper compound, on rat malignant glioma C6 cells was investigated. Results Cas III-ia significantly inhibited cell proliferation, inducing autophagy and apoptosis, which correlated with the formation of autophagic vacuoles, overexpression of LC3, Beclin 1, Atg 7, Bax and Bid proteins. A decrease was detected in the mitochondrial membrane potential and in the activity of caspase 3 and 8, together with the generation of intracellular reactive oxygen species (ROS) and increased activity of c-jun NH2-terminal kinase (JNK). The presence of 3-methyladenine (as selective autophagy inhibitor) increased the antineoplastic effect of Cas III-ia, while Z-VAD-FMK only showed partial protection from the antineoplastic effect induced by Cas III-ia, and ROS antioxidants (N-acetylcysteine) decreased apoptosis, autophagy and JNK activity. Moreover, the JNK –specific inhibitor SP600125 prevented Cas III-ia-induced cell death. Conclusions Our data suggest that Cas III-ia induces cell death by autophagy and apoptosis, in part due to the activation of ROS –dependent JNK signaling. These findings support further studies of Cas III-ia as candidate for treatment of human malignant glioma. PMID:22540380

  19. Role of autophagy in cadmium-induced apoptosis of primary rat osteoblasts.

    PubMed

    Liu, Wei; Dai, Nannan; Wang, Yi; Xu, Chao; Zhao, Hongyan; Xia, Pengpeng; Gu, Jianhong; Liu, Xuezhong; Bian, Jianchun; Yuan, Yan; Zhu, Jiaqiao; Liu, Zongping

    2016-01-01

    Cadmium (Cd) is a common environmental pollutant that can damage many organs and the fetus. We previously reported that Cd induced apoptosis in primary rat osteoblasts (OBs). OB apoptosis induced by Cd will eventually lead to osteoporosis. In this study, a novel pharmacotherapeutic approach was investigated involving the regulation of autophagy to prevent Cd osteoporosis. The results showed that Cd treatment induced apoptosis in OBs, as demonstrated by the ratio of Bax/Bcl-2, activation of poly (ADP-ribose) polymerase (PARP) and nuclear condensation. In addition, cells treated with Cd were observed to undergo autophagic cell death by monitoring the induction of the beclin 1, autophagy gene 5 (Atg5) and the expression of microtubule-associated protein 1 light chain 3 (LC3). The results indicated that promotion of apoptotic cell death by Cd is accompanied by induction of autophagy in OBs. Interestingly, Cd-mediated apoptotic cell death was suppressed by pretreatment with the autophagy activator rapamycin (RAP) and potentiated by the autophagy inhibitor chloroquine (CQ) or small interfering RNA against beclin 1. These findings suggest that the autophagic response plays a protective role that impedes eventual cell death. Activation of autophagy could therefore be an adjunctive strategy for treatment of Cd-induced osteoporosis. PMID:26852917

  20. Baicalin prevents Candida albicans infections via increasing its apoptosis rate

    SciTech Connect

    Yang, Shulong; Fu, Yingyuan Wu, Xiuzhen; Zhou, Zhixing; Xu, Jing; Zeng, Xiaoping; Kuang, Nanzhen; Zeng, Yurong

    2014-08-15

    Highlights: • Baicalin increases the ratio of the G0/G1 stages and C. albicans apoptosis. • Baicalin decreases the proliferation index of C. albicans. • Baicalin inhibits the biosynthesis of DNA, RNA and protein in C. albicans. • Baicalin depresses Succinate Dehydrogenase and Ca{sup 2+}–Mg{sup 2+} ATPase in C. albicans. • Baicalin increases the endocytic free Ca{sup 2+} concentration in C. albicans. - Abstract: Background: These experiments were employed to explore the mechanisms underlying baicalin action on Candida albicans. Methodology and principal findings: We detected the baicalin inhibition effects on three isotope-labeled precursors of {sup 3}H-UdR, {sup 3}H-TdR and {sup 3}H-leucine incorporation into C. albicans using the isotope incorporation technology. The activities of Succinate Dehydrogenase (SDH), cytochrome oxidase (CCO) and Ca{sup 2+}–Mg{sup 2+} ATPase, cytosolic Ca{sup 2+} concentration, the cell cycle and apoptosis, as well as the ultrastructure of C.albicans were also tested. We found that baicalin inhibited {sup 3}H-UdR, {sup 3}H-TdR and {sup 3}H-leucine incorporation into C.albicans (P < 0.005). The activities of the SDH and Ca{sup 2+}–Mg{sup 2+} ATPase of C.albicans in baicalin groups were lower than those in control group (P < 0.05). Ca{sup 2+} concentrations of C. albicans in baicalin groups were much higher than those in control group (P < 0.05). The ratio of C.albicans at the G0/G1 stage increased in baicalin groups in dose dependent manner (P < 0.01). There were a significant differences in the apoptosis rate of C.albicans between baicalin and control groups (P < 0.01). After 12–48 h incubation with baicalin (1 mg/ml), C. albicans shown to be markedly damaged under transmission electron micrographs. Innovation and significance: Baicalin can increase the apoptosis rate of C. albicans. These effects of Baicalin may involved in its inhibiting the activities of the SDH and Ca{sup 2+}–Mg{sup 2+} ATPase, increasing

  1. Lowering blood ammonia prevents hepatocyte injury and apoptosis

    PubMed Central

    Gao, Guanmin; Yu, Zujiang; Yan, Jingya; Li, Jingjing; Shen, Shen; Jia, Bin; Guan, Kelei; Gao, Xiaojuan; Kan, Quancheng

    2015-01-01

    To study hepatocyte injure through establishing the rat model of acute hepatic failure (ALF). ALF rat model was established by administration with D-galactosamine and LPS, and then giving lowering blood ammonia (LBA) treatment. Besides, the intervention groups were injected with ornithine and aspartate. The control groups were injected saline. Blood ammonia, ALT, AST, TNF-α and IL-6 in blood samples were test at 12 hrs and 24 hrs after treatment with LBA. Hepatocyte apoptosis were tested by TUNEL and DNA Ladder. Expression of P53 and SPP1 were detected by RT-PCR. Results: showed that blood ammonia in hepatic failure group and intervention group compared with blank control group was significantly increased at 12 h, 24 h; intervention group compared with hepatic failure group was significantly reduced (P<0.05). Serum ALT, AST in 24 h group were higher than 12 h. 12 h intervention group was decreased compared with hepatic failure group, but there was no significant statistically difference (P>0.05). 24 h intervention group compared with hepatic failure group was significantly reduced (P<0.05). Except the control group, DNA ladder and the TUNEL results showed hepatocyte apoptosis rate increased in 24 h compared with 12 h. Intervention group compared with hepatic failure group was significantly reducing (P<0.05). IL-6, TNF-α, p53 expression levels were increased with time (24 h>12 h). The hepatic failure and intervention group compared with blank control group was significantly increased; Intervention group compared with hepatic failure group was significantly reducing (P<0.05). SPP1 gene was high expression in ALF rat model. SPP1 level in hepatic failure and intervention group compared with control group was significantly increased, and intervention group compared with hepatic failure group was significantly reducing (P<0.05). In conclusion, hepatocyte apoptosis is an important pathological change in ALF rat mode, and lowing ammonia can reduce liver injury and

  2. Curcumin induces apoptosis by inhibiting sarco/endoplasmic reticulum Ca2+ ATPase activity in ovarian cancer cells.

    PubMed

    Seo, Jeong-Ah; Kim, Boyun; Dhanasekaran, Danny N; Tsang, Benjamin K; Song, Yong Sang

    2016-02-01

    Aberrant increase in the expression levels of sarco/endoplasmic reticulum calcium ATPase (SERCA), which regulates Ca(2+) homeostasis, has been observed in ovarian cancers. In this study, we demonstrated that curcumin increases cytosolic Ca(2+) concentration through inhibition of SERCA activity, causing apoptosis in ovarian cancer cells but not in normal cells, including peripheral blood mononuclear cells (PBMCs) and ovarian surface epithelial cells (OSE). Curcumin induced apoptosis in ovarian cancer cells in a concentration- and time-dependent manner. Cytosolic Ca(2+) flux was evident after the curcumin treatment (15 µM). Treatment with Ca(2+) chelator reduced curcumin-induced apoptosis, confirming the possible involvement of increased cytosolic Ca(2+) concentration in this response. Basal mRNA and protein levels of SERCA2 were significantly higher in ovarian cancer cells than in OSE. SERCA activity was suppressed by curcumin, with no effect on protein expression. Forced expression of the SERCA2b gene in ovarian cancer cells prevented curcumin-induced cytosolic Ca(2+) elevation and subsequent apoptosis, supporting an important role of SERCA in curcumin-induced apoptosis of ovarian cancer cells. Taken together, inhibition of SERCA activity by curcumin disrupts the Ca(2+) homeostasis and thereby promotes apoptosis in ovarian cancer cells.

  3. Curcumin induces apoptosis by inhibiting sarco/endoplasmic reticulum Ca2+ ATPase activity in ovarian cancer cells.

    PubMed

    Seo, Jeong-Ah; Kim, Boyun; Dhanasekaran, Danny N; Tsang, Benjamin K; Song, Yong Sang

    2016-02-01

    Aberrant increase in the expression levels of sarco/endoplasmic reticulum calcium ATPase (SERCA), which regulates Ca(2+) homeostasis, has been observed in ovarian cancers. In this study, we demonstrated that curcumin increases cytosolic Ca(2+) concentration through inhibition of SERCA activity, causing apoptosis in ovarian cancer cells but not in normal cells, including peripheral blood mononuclear cells (PBMCs) and ovarian surface epithelial cells (OSE). Curcumin induced apoptosis in ovarian cancer cells in a concentration- and time-dependent manner. Cytosolic Ca(2+) flux was evident after the curcumin treatment (15 µM). Treatment with Ca(2+) chelator reduced curcumin-induced apoptosis, confirming the possible involvement of increased cytosolic Ca(2+) concentration in this response. Basal mRNA and protein levels of SERCA2 were significantly higher in ovarian cancer cells than in OSE. SERCA activity was suppressed by curcumin, with no effect on protein expression. Forced expression of the SERCA2b gene in ovarian cancer cells prevented curcumin-induced cytosolic Ca(2+) elevation and subsequent apoptosis, supporting an important role of SERCA in curcumin-induced apoptosis of ovarian cancer cells. Taken together, inhibition of SERCA activity by curcumin disrupts the Ca(2+) homeostasis and thereby promotes apoptosis in ovarian cancer cells. PMID:26607901

  4. MK591, a second generation leukotriene biosynthesis inhibitor, prevents invasion and induces apoptosis in the bone-invading C4-2B human prostate cancer cells: implications for the treatment of castration-resistant, bone-metastatic prostate cancer.

    PubMed

    Sarveswaran, Sivalokanathan; Ghosh, Ritisha; Morisetty, Shravan; Ghosh, Jagadananda

    2015-01-01

    Castration-resistant prostate cancer (CRPC) is a major clinical challenge for which no cure is currently available primarily because of the lack of proper understanding about appropriate molecular target(s). Previously we observed that inhibition of 5-lipoxygenase (5-Lox) activity induces apoptosis in some types of prostate cancer cells, suggesting an important role of 5-Lox in the viability of prostate cancer cells. However, nothing is known about the role of 5-Lox in the survival of castration-resistant, metastatic prostate cancer cells. Thus, we tested the effects of MK591, a second-generation, specific inhibitor of 5-Lox activity, on the viability and metastatic characteristics of CRPC cells. We observed that MK591 effectively kills the bone-invading C4-2B human prostate cancer cells (which bear characteristics of CRPC), but does not affect normal, non-cancer fibroblasts (which do not express 5-Lox) in the same experimental conditions. We also observed that MK591 dramatically inhibits the in vitro invasion and soft-agar colony formation of C4-2B cells. Interestingly, we found that treatment with MK591 dramatically down-regulates the expression of c-Myc and its targets at sub-lethal doses. In light of frequent over-activation of c-Myc in a spectrum of aggressive cancers (including CRPC), and the challenges associated with inhibition of c-Myc (because of its non-enzymatic nature), our novel findings of selective killing, and blockade of invasive and soft-agar colony-forming abilities of the castration-resistant, bone-metastatic C4-2B prostate cancer cells by MK591, open up a new avenue to attack CRPC cells for better management of advanced prostate cancer while sparing normal, non-cancer body cells.

  5. 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

  6. 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

  7. N-acetylcysteine protects against cadmium-induced germ cell apoptosis by inhibiting endoplasmic reticulum stress in testes.

    PubMed

    Ji, Yan-Li; Wang, Hua; Zhang, Cheng; Zhang, Ying; Zhao, Mei; Chen, Yuan-Hua; Xu, De-Xiang

    2013-03-01

    Cadmium (Cd) is a reproductive toxicant that induces germ cell apoptosis in the testes. Previous studies have demonstrated that endoplasmic reticulum (ER) stress is involved in Cd-induced germ cell apoptosis. The aim of the present study was to investigate the effects of N-acetylcysteine (NAC), an antioxidant, on Cd-induced ER stress and germ cell apoptosis in the testes. Male CD-1 mice were intraperitoneally injected with CdCl2 (2.0 mg kg(-1)). As expected, acute Cd exposure induced germ cell apoptosis in the testes, as determined by terminal dUTP nick-end labelling (TUNEL). However, the administration of NAC alleviated Cd-induced germ cell apoptosis in the testes. Further analysis showed that NAC attenuated the Cd-induced upregulation of testicular glucose-regulated protein 78 (GRP78), an important ER molecular chaperone. Moreover, NAC inhibited the Cd-induced phosphorylation of testicular eukaryotic translation initiation factor 2α (eIF2α), a downstream target of the double-stranded RNA-activated kinase-like ER kinase (PERK) pathway. In addition, NAC blocked the Cd-induced activation of testicular X binding protein (XBP)-1, indicating that NAC attenuates the Cd-induced ER stress and the unfolded protein response (UPR). Interestingly, NAC almost completely prevented the Cd-induced elevation of C/EBP homologous protein (CHOP) and phosphorylation of c-Jun N-terminal kinase (JNK), two components of the ER stress-mediated apoptotic pathway. In conclusion, NAC protects against Cd-induced germ cell apoptosis by inhibiting endoplasmic reticulum stress in the testes. PMID:23353715

  8. 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.

  9. Neuropeptide Y protects kidney against cisplatin-induced nephrotoxicity by regulating p53-dependent apoptosis pathway

    PubMed Central

    Kim, Namoh; Min, Woo-Kie; Park, Min Hee; Lee, Jong Kil; Jin, Hee Kyung; Bae, Jae-sung

    2016-01-01

    Cisplatin is a platinum-based chemotherapeutic drug for treating various types of cancers. However, the use of cisplatin is limited by its negative effect on normal tissues, particularly nephrotoxicity. Various mechanisms such as DNA adduct formation, mitochondrial dysfunction, oxidative stress, and apoptosis are involved in the adverse effect induced by cisplatin treatment. Several studies have suggested that neuropeptide Y (NPY) is involved in neuroprotection as well as restoration of bone marrow dysfunction from chemotherapy induced nerve injury. However, the role of NPY in chemotherapy-induced nephrotoxicity has not been studied. Here, we show that NPY rescues renal dysfunction by reducing the expression of pro-apoptotic proteins in cisplatin induced nephrotoxicity through Y1 receptor, suggesting that NPY can protect kidney against cisplatin nephrotoxicity as a possible useful agent to prevent and treat cisplatin-induced nephrotoxicity. [BMB Reports 2016; 49(5): 288-292] PMID:26728272

  10. Amplification activation loop between caspase-8 and -9 dominates artemisinin-induced apoptosis of ASTC-a-1 cells.

    PubMed

    Xiao, Fenglian; Gao, Weijie; Wang, Xiaoping; Chen, Tongsheng

    2012-06-01

    Although caspases have been demonstrated to be involved in artemisinin (ARTE)-induced apoptosis, their exact functions are not well understood. The aim of this report is to explore the roles of caspase-8, -9 and -3 during ARTE-induced apoptosis in human lung adenocarcinoma (ASTC-a-1) cells. ARTE treatment induces a rapid generation of reactive oxygen species (ROS), and ROS-dependent apoptosis as well as the activation of caspase-8, -9 and -3 via time- and dose-dependent fashion. Of upmost importance, inhibition of caspase-8 or -9, but not caspase-3, almost completely blocks the ARTE-induced not only activation of the caspase-8, -9 and -3 but also apoptosis. In addition, the apoptotic process triggered by ARTE does not involve the Bid cleavage, tBid translocation, significant loss of mitochondrial membrane potential and cytochrome c release from mitochondria. Moreover, silencing Bax/Bak does not prevent the ATRE-induced cell death as well as the activation of caspase-8, -9 and -3. Collectively, our data firstly demonstrate that ARTE triggers a ROS-mediated positive feedback amplification activation loop between caspase-8 and -9 independent of mitochondria, which dominantly mediated the ARTE-induced apoptosis via a caspase-3-independent apoptotic pathway in ASTC-a-1 cells. Our findings imply a potential to develop new derivatives from artemisinin to effectively initiate the amplification activation loop of caspases. PMID:22434375

  11. Amplification activation loop between caspase-8 and -9 dominates artemisinin-induced apoptosis of ASTC-a-1 cells.

    PubMed

    Xiao, Fenglian; Gao, Weijie; Wang, Xiaoping; Chen, Tongsheng

    2012-06-01

    Although caspases have been demonstrated to be involved in artemisinin (ARTE)-induced apoptosis, their exact functions are not well understood. The aim of this report is to explore the roles of caspase-8, -9 and -3 during ARTE-induced apoptosis in human lung adenocarcinoma (ASTC-a-1) cells. ARTE treatment induces a rapid generation of reactive oxygen species (ROS), and ROS-dependent apoptosis as well as the activation of caspase-8, -9 and -3 via time- and dose-dependent fashion. Of upmost importance, inhibition of caspase-8 or -9, but not caspase-3, almost completely blocks the ARTE-induced not only activation of the caspase-8, -9 and -3 but also apoptosis. In addition, the apoptotic process triggered by ARTE does not involve the Bid cleavage, tBid translocation, significant loss of mitochondrial membrane potential and cytochrome c release from mitochondria. Moreover, silencing Bax/Bak does not prevent the ATRE-induced cell death as well as the activation of caspase-8, -9 and -3. Collectively, our data firstly demonstrate that ARTE triggers a ROS-mediated positive feedback amplification activation loop between caspase-8 and -9 independent of mitochondria, which dominantly mediated the ARTE-induced apoptosis via a caspase-3-independent apoptotic pathway in ASTC-a-1 cells. Our findings imply a potential to develop new derivatives from artemisinin to effectively initiate the amplification activation loop of caspases.

  12. 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

  13. Vinegar Treatment Prevents the Development of Murine Experimental Colitis via Inhibition of Inflammation and Apoptosis.

    PubMed

    Shen, Fengge; Feng, Jiaxuan; Wang, Xinhui; Qi, Zhimin; Shi, Xiaochen; An, Yanan; Zhang, Qiaoli; Wang, Chao; Liu, Mingyuan; Liu, Bo; Yu, Lu

    2016-02-10

    This study investigated the preventive effects of vinegar and acetic acid (the active component of vinegar) on ulcerative colitis (UC) in mice. Vinegar (5% v/v) or acetic acid (0.3% w/v) treatment significantly reduced the disease activity index and histopathological scores, attenuated body weight loss, and shortened the colon length in a murine experimental colitis model induced by dextran sulfate sodium (DSS). Further mechanistic analysis showed that vinegar inhibited inflammation through suppressing Th1 and Th17 responses, the NLRP3 inflammasome, and MAPK signaling activation. Vinegar also inhibited endoplasmic reticulum (ER) stress-mediated apoptosis in the colitis mouse model. Surprisingly, pretreatment with vinegar for 28 days before DSS induction increased levels of the commensal lactic acid-producing or acetic acid-producing bacteria, including Lactobacillus, Bifidobacteria, and Enterococcus faecalis, whereas decreased Escherichia coli levels were found in the feces of mice. These results suggest that vinegar supplementation might provide a new dietary strategy for the prevention of UC.

  14. Galiellalactone induces cell cycle arrest and apoptosis through the ATM/ATR pathway in prostate cancer cells.

    PubMed

    García, Víctor; Lara-Chica, Maribel; Cantarero, Irene; Sterner, Olov; Calzado, Marco A; Muñoz, Eduardo

    2016-01-26

    Galiellalactone (GL) is a fungal metabolite that presents antitumor activities on prostate cancer in vitro and in vivo. In this study we show that GL induced cell cycle arrest in G2/M phase, caspase-dependent apoptosis and also affected the microtubule organization and migration ability in DU145 cells. GL did not induce double strand DNA break but activated the ATR and ATM-mediated DNA damage response (DDR) inducing CHK1, H2AX phosphorylation (fH2AX) and CDC25C downregulation. Inhibition of the ATM/ATR activation with caffeine reverted GL-induced G2/M cell cycle arrest, apoptosis and DNA damage measured by fH2AX. In contrast, UCN-01, a CHK1 inhibitor, prevented GL-induced cell cycle arrest but enhanced apoptosis in DU145 cells. Furthermore, we found that GL did not increase the levels of intracellular ROS, but the antioxidant N-acetylcysteine (NAC) completely prevented the effects of GL on fH2AX, G2/M cell cycle arrest and apoptosis. In contrast to NAC, other antioxidants such as ambroxol and EGCG did not interfere with the activity of GL on cell cycle. GL significantly suppressed DU145 xenograft growth in vivo and induced the expression of fH2AX in the tumors. These findings identify for the first time that GL activates DDR in prostate cancer.

  15. Galiellalactone induces cell cycle arrest and apoptosis through the ATM/ATR pathway in prostate cancer cells

    PubMed Central

    García, Víctor; Lara-Chica, Maribel; Cantarero, Irene; Sterner, Olov; Calzado, Marco A.; Muñoz, Eduardo

    2016-01-01

    Galiellalactone (GL) is a fungal metabolite that presents antitumor activities on prostate cancer in vitro and in vivo. In this study we show that GL induced cell cycle arrest in G2/M phase, caspase-dependent apoptosis and also affected the microtubule organization and migration ability in DU145 cells. GL did not induce double strand DNA break but activated the ATR and ATM-mediated DNA damage response (DDR) inducing CHK1, H2AX phosphorylation (fH2AX) and CDC25C downregulation. Inhibition of the ATM/ATR activation with caffeine reverted GL-induced G2/M cell cycle arrest, apoptosis and DNA damage measured by fH2AX. In contrast, UCN-01, a CHK1 inhibitor, prevented GL-induced cell cycle arrest but enhanced apoptosis in DU145 cells. Furthermore, we found that GL did not increase the levels of intracellular ROS, but the antioxidant N-acetylcysteine (NAC) completely prevented the effects of GL on fH2AX, G2/M cell cycle arrest and apoptosis. In contrast to NAC, other antioxidants such as ambroxol and EGCG did not interfere with the activity of GL on cell cycle. GL significantly suppressed DU145 xenograft growth in vivo and induced the expression of fH2AX in the tumors. These findings identify for the first time that GL activates DDR in prostate cancer. PMID:26683224

  16. 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

  17. 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.

  18. 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

  19. 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.

  20. Curcumin alleviates glucocorticoid-induced osteoporosis by protecting osteoblasts from apoptosis in vivo and in vitro.

    PubMed

    Chen, Zhiguang; Xue, Jinqi; Shen, Tao; Ba, Gen; Yu, Dongdong; Fu, Qin

    2016-02-01

    Curcumin, an active component of the rhizomes of Curcumin longa L., possesses broad anti-inflammation and anti-cancer properties. Curcumin was previously reported to be capable of protecting ovariectomized rats against osteoporosis. However, the effect of curcumin on glucocorticoid-induced osteoporosis (GIO) is not yet clear. The present study investigated the effects of curcumin on dexamethasone (Dex)-induced osteoporosis in vivo and Dex-induced osteoblast apoptosis in vivo and in vitro. The GIO rat model was induced by subcutaneous injection of Dex for 60 days and verified to be successful as evidenced by the significantly decreased bone mineral density (BMD) determined using dual X-ray absorptiometry. Subsequently, curcumin administration (100 mg/kg) for 60 days obviously increased BMD and bone-alkaline phosphatase, decreased carboxy-terminal collagen cross links, enhanced bone mechanical strength, and improved trabecular microstructure, thereby alleviating Dex-induced osteoporosis. Mechanically, curcumin remarkably reversed Dex-induced femoral osteoblast apoptosis in vivo. In cultured primary osteoblasts, pretreatment with curcumin concentration-dependently decreased the number of Dex-induced apoptotic osteoblasts by down-regulating the ratio of Bax/Bcl-2 as well as the levels of cleaved caspase-3 and cleaved poly ADP-ribose polymerase (PARP). Moreover, curcumin pretreatment activated extracellular signal regulated kinase (ERK) signalling in Dex-induced osteoblasts by up-regulating the expression level of p-ERK1/2. Taken together, our study demonstrated that curcumin could ameliorate GIO by protecting osteoblasts from apoptosis, which was possibly related to the activation of the ERK pathway. The results suggest that curcumin may be a promising drug for prevention and treatment of GIO.

  1. Opioids induce while nicotine suppresses apoptosis in human lung cancer cells.

    PubMed

    Maneckjee, R; Minna, J D

    1994-10-01

    Previously, we have shown that opioids acting via specific receptors inhibit the growth of human lung cancer cells while nicotine, acting through nicotinic acetylcholine receptors, reverses this inhibition. Therefore, we studied the role of apoptosis in these processes. Treatment of human lung cancer cells with 0.1-1 microM morphine or methadone resulted in morphological changes and cleavage of DNA into nucleosome-sized fragments characteristic of apoptosis. Quantitation of DNA fragmentation showed that a dose-dependent increase occurred within 2 h of opioid treatment and was blocked by the antagonist naloxone. The apoptotic effect of opioids was suppressed by nicotine, while the nicotinic acetylcholine receptor antagonists, hexamethonium and decamethonium, reversed this suppression. In contrast, sphingosine, a protein kinase C inhibitor, caused significant DNA fragmentation which was not suppressed by nicotine. Unexpectedly, the combination of hexamethonium and opioids or hexamethonium and nicotine stimulated apoptosis. We found that nicotine, like phorbol 12-myristate 13-acetate, increased total protein kinase C (PKC) activity, while morphine and sphingosine decreased PKC activity, and nicotine reversed morphine inhibition of PKC activity. In contrast, methadone unexpectedly increased PKC activity. These results indicate that engagement of opioid receptors in human lung cancer cells induces apoptosis, while engagement of nicotine receptors suppresses apoptosis, which in some cases appear to be working through a PKC pathway. They also suggest complexities in the system where blockade of C6 or C10 nicotinic receptors can lead to facilitation of apoptosis. These findings suggest new strategies for treatment and prevention of cancer using opioids or nicotine receptors antagonists and are consistent with the idea that nicotine functions as a tumor promoter. PMID:7848904

  2. Myosin translocation in retinal pericytes during free-radical induced apoptosis.

    PubMed

    Shojaee, N; Patton, W F; Hechtman, H B; Shepro, D

    1999-10-01

    Vascular pathologies induced by ischemia/reperfusion involve the production of reactive oxygen species (ROS) that in part cause tissue injury. The production of ROS that occurs upon reperfusion activates specific second messenger pathways. In diabetic retinopathy there is a characteristic loss of the microvascular pericyte. Pericytes are more sensitive than endothelial cells to low concentrations of ROS, such as hydrogen peroxide (H(2)O(2)) when tested in vitro. Whether the pericyte loss is due to toxic cell death triggered by the noxious H(2)O(2) or apoptosis, due to activation of specific second messenger pathways, is unknown. During apoptosis, a cell's nucleus and cytoplasm condense, the cell becomes fragmented, and ultimately forms apoptotic bodies. It is generally assumed that apoptosis depends on nuclear signaling, but cytoplasmic morphological processes are not well described. We find that exposing cultured retinal pericytes to 100 microM H(2)O(2) for 30 min leads to myosin heavy chain translocation from the cytosol to the cytoskeleton and a significant decrease in cell surface area. Pericyte death follows within 60-120 min. Exposing cells to 150 mJ/cm(2) ultraviolet radiation, an alternate free radical generating system, also causes pericyte myosin translocation and apoptosis. Proteolytic cleavage of actin is not observed in pericyte apoptosis. 3-aminobenzamide, a pharmacological inhibitor of the cleavage and activation of the DNA-repairing enzyme poly (ADP-ribose) polymerase (PARP) inhibits pericyte apoptosis, and prevents myosin translocation. Deferoxamine, an iron chelator known to interfere with free radical generation, also inhibits pericyte myosin translocation, contractility, and cell death. Myosin translocation to the cytoskeleton may be an early step in assembly of a competent contractile apparatus, which is involved in apoptotic cell condensation. These results suggest that pericyte loss associated with increased free radical production in

  3. Protective Role of Raf-1 in Salmonella-Induced Macrophage Apoptosis

    PubMed Central

    Jesenberger, Veronika; Procyk, Katarzyna J.; Rüth, Jochen; Schreiber, Martin; Theussl, Hans-Christian; Wagner, Erwin F.; Baccarini, Manuela

    2001-01-01

    Invasive Salmonella induces macrophage apoptosis via the activation of caspase-1 by the bacterial protein SipB. Here we show that infection of macrophages with Salmonella causes the activation and degradation of Raf-1, an important intermediate in macrophage proliferation and activation. Raf-1 degradation is SipB- and caspase-1–dependent, and is prevented by proteasome inhibitors. To study the functional significance of Raf-1 in this process, the c-raf-1 gene was inactivated by Cre-loxP–mediated recombination in vivo. Macrophages lacking c-raf-1 are hypersensitive towards pathogen-induced apoptosis. Surprisingly, activation of the antiapoptotic mitogen-activated protein kinase kinase (MEK)/extracellular signal–regulated kinase (ERK) and nuclear factor κB pathways is normal in Raf-1–deficient macrophages, and mitochondrial fragility is not increased. Instead, pathogen-mediated activation of caspase-1 is enhanced selectively, implying that Raf-1 antagonizes stimulus-induced caspase-1 activation and apoptosis. PMID:11157055

  4. Alpha fetoprotein antagonizes apoptosis induced by paclitaxel in hepatoma cells in vitro.

    PubMed

    Zhu, Mingyue; Li, Wei; Lu, Yan; Dong, Xu; Chen, Yi; Lin, Bo; Xie, Xieju; Guo, Junli; Li, Mengsen

    2016-01-01

    Hepatocellular carcinoma (HCC) cell resistance to the effects of paclitaxel has not been adequately addressed. In this study, we found that paclitaxel significantly inhibited the viability of HLE, Bel 7402 and L-02 cells in a dose- and time-dependent manner. HLE cells and L-02 cells resisted the cytotoxicity of paclitaxel when transfected with pcDNA3.1-afp vectors. However, Bel 7402 cell sensitivity to paclitaxel was increased when transfected with alpha fetoprotein (AFP)-siRNA. Bel 7402 cell resistance to paclitaxel was associated with the expression of the "stemness" markers CD44 and CD133. Paclitaxel significantly inhibited growth and promoted apoptosis in HLE cells and L-02 cells by inducing fragmentation of caspase-3 and inhibiting the expression of Ras and Survivin, but pcDNA3.1-afp vectors prevented these effects. However, paclitaxel could not significantly promote the cleavage of caspase-3 or suppress the expression of Ras and Survivin in Bel 7402 cells. Silenced expression of AFP may be synergistic with paclitaxel to restrain proliferation and induce apoptosis, enhance cleavage of caspase-3, and suppress the expression of Ras and Survivin. Taken together, AFP may be an important molecule acting against paclitaxel-inhibited proliferation and induced apoptosis in HCC cells via repressing the activity of caspase-3 and stimulating the expression of Ras and Survivin. Targeted inhibition of AFP expression after treatment with paclitaxel is an available strategy for the therapy of patients with HCC. PMID:27255186

  5. Alpha fetoprotein antagonizes apoptosis induced by paclitaxel in hepatoma cells in vitro

    PubMed Central

    Zhu, Mingyue; Li, Wei; Lu, Yan; Dong, Xu; Chen, Yi; Lin, Bo; Xie, Xieju; Guo, Junli; Li, Mengsen

    2016-01-01

    Hepatocellular carcinoma (HCC) cell resistance to the effects of paclitaxel has not been adequately addressed. In this study, we found that paclitaxel significantly inhibited the viability of HLE, Bel 7402 and L-02 cells in a dose- and time-dependent manner. HLE cells and L-02 cells resisted the cytotoxicity of paclitaxel when transfected with pcDNA3.1-afp vectors. However, Bel 7402 cell sensitivity to paclitaxel was increased when transfected with alpha fetoprotein (AFP)-siRNA. Bel 7402 cell resistance to paclitaxel was associated with the expression of the “stemness” markers CD44 and CD133. Paclitaxel significantly inhibited growth and promoted apoptosis in HLE cells and L-02 cells by inducing fragmentation of caspase-3 and inhibiting the expression of Ras and Survivin, but pcDNA3.1-afp vectors prevented these effects. However, paclitaxel could not significantly promote the cleavage of caspase-3 or suppress the expression of Ras and Survivin in Bel 7402 cells. Silenced expression of AFP may be synergistic with paclitaxel to restrain proliferation and induce apoptosis, enhance cleavage of caspase-3, and suppress the expression of Ras and Survivin. Taken together, AFP may be an important molecule acting against paclitaxel-inhibited proliferation and induced apoptosis in HCC cells via repressing the activity of caspase-3 and stimulating the expression of Ras and Survivin. Targeted inhibition of AFP expression after treatment with paclitaxel is an available strategy for the therapy of patients with HCC. PMID:27255186

  6. Sodium Ascorbate induces apoptosis in neuroblastoma cell lines by interfering with iron uptake

    PubMed Central

    Carosio, Roberta; Zuccari, Guendalina; Orienti, Isabella; Mangraviti, Salvatore; Montaldo, Paolo G

    2007-01-01

    Background Neuroblastoma (NB) is an extra-cranial solid tumour of childhood. In spite of the good clinical response to first-line therapy, complete eradication of NB cells is rarely achieved. Thus, new therapeutic strategies are needed to eradicate surviving NB cells and prevent relapse. Sodium ascorbate has been recently reported to induce apoptosis of B16 melanoma cells through down-regulation of the transferrin receptor, CD71. Since NB and melanoma share the same embryologic neuroectodermal origin, we used different human NB cell lines to assess whether the same findings occurred. Results We could observe dose- and time-dependent induction of apoptosis in all NB cell lines. Sodium ascorbate decreased the expression of CD71 and caused cell death within 24 h. An increase in the global and specific caspase activity took place, as well as an early loss of the mitochondrial transmembrane potential. Moreover, intracellular iron was significantly decreased after exposure to sodium ascorbate. Apoptotic markers were reverted when the cells were pretreated with the iron donor ferric ammonium citrate (FAC), further confirming that iron depletion is responsible for the ascorbate-induced cell death in NB cells. Conclusion Sodium ascorbate is highly toxic to neuroblastoma cell lines and the specific mechanism of vitamin C-induced apoptosis is due to a perturbation of intracellular iron levels ensuing TfR-downregulation. PMID:17760959

  7. Lycopene supplementation prevents reactive oxygen species mediated apoptosis in Sertoli cells of adult albino rats exposed to polychlorinated biphenyls

    PubMed Central

    Krishnamoorthy, Gunasekaran; Selvakumar, Kandaswamy; Venkataraman, Prabhu; Elumalai, Perumal

    2013-01-01

    Sertoli cell proliferation is attenuated before attaining puberty and the number is fixed in adult testes. Sertoli cells determine both testis size and daily sperm production by providing physical and metabolic support to spermatogenic cells. Polychlorinated biphenyls (PCBs) exposure disrupts functions of Sertoli cells causing infertility with decreased sperm count. On the other hand, lycopene is improving sperm count and motility by reducing oxidative stress in humans and animals. Hence we hypothesized that PCBs-induced infertility might be due to Sertoli cell apoptosis mediated by oxidative stress and lycopene might prevent PCBs-induced apoptosis by acting against oxidative stress. To test this hypothesis, animals were treated with vehicle control, lycopene, PCBs and PCBs + lycopene for 30 days. After the experimental period, the testes and cauda epididymidis were removed for isolation of Sertoli cells and sperm, respectively. We observed increased levels of oxidative stress markers (H2O2 and LPO) levels, increased expression of apoptotic molecules (caspase-8, Bad, Bid, Bax, cytochrome C and caspase-3), decreased anti-apoptotic (Bcl2) molecule and elevated apoptotic marker activity (caspase-3) in Sertoli cells of PCBs-exposed animals. These results were associated with decreased sperm count and motility in PCBs exposed animals. On the other hand, lycopene prevented the elevation of Sertoli cellular apoptotic parameters and prevented the reduction of sperm parameters (count and motility). The data confirmed that lycopene as an antioxidant scavenged reactive oxygen substances, prevented apoptosis, maintained normal function in Sertoli cells and helped to provide physical and metabolic support for sperm production, thereby treating infertility in men. PMID:24179434

  8. Endothelial Cell Apoptosis Induces TGF-β Signaling-Dependent Host Endothelial-Mesenchymal Transition to Promote Transplant Arteriosclerosis.

    PubMed

    Li, J; Xiong, J; Yang, B; Zhou, Q; Wu, Y; Luo, H; Zhou, H; Liu, N; Li, Y; Song, Z; Zheng, Q

    2015-12-01

    Endothelial cells (ECs) apoptosis is an initial event in transplant arteriosclerosis (TA), resulting in allograft function loss. To elucidate the precise mechanisms of ECs apoptosis leading to neointimal smooth muscle cells (SMCs) accumulation during TA. We induced apoptosis in cultured ECs by overexpressing p53 through lentivirus-mediated transfection. ECs apoptosis induced the production of transforming growth factor (TGF)-β1 in both apoptotic and neighboring viable cells, leading to increased TGF-β1 in the culture media. Conditioned media from Ltv-p53-transfected ECs further promoted transition of cultured ECs to SM-like cells by activating TGF-β/Smad3, PI3K/Akt/mTOR, and MAPK/ERK signaling in a TGF-β-dependent manner. In transgenic rat aorta transplantation models, inhibition of ECs apoptosis in Bcl-xL(+/+) knock-in rat aortic allografts significantly reduced TGF-β1 production both in allograft endothelia and in blood plasma, which in turn decreased accumulation of SM22α+ cells from transgenic recipient ECs originally marked with EGFP knock-in in neointima and alleviated TA. Systemic treatment with SIS3, AP23573, or PD98059 also prevented recipient ECs-originated SM-like cells accumulation and intima hyperplasia in aortic allografts. These data suggest that allograft EC apoptosis induced recipient endothelial-mesenchymal (smooth muscle) transition via TGF-β signaling, resulting in recipient EC-derived SMC accumulation as a major mechanism of vascular remodeling during TA.

  9. A new pharmacological role for donepezil: attenuation of morphine-induced tolerance and apoptosis in rat central nervous system

    PubMed Central

    2014-01-01

    Background Tolerance to the analgesic effect of opioids is a pharmacological phenomenon that occurs after their prolonged administration. It has been shown that morphine-induced tolerance is associated with apoptosis in the central nervous system and neuroprotective agents which prevented apoptosis signaling could attenuate tolerance to the analgesic effects. On the other hand donepezil, an acetylcholinesterase inhibitor, has been reported to have neuroprotective effects. Therefore in this study, the effect of systemic administration of donepezil on morphine-induced tolerance and apoptosis in the rat cerebral cortex and lumbar spinal cord was evaluated. Various groups of rats received morphine (ip) and different doses of donepezil (0, 0.5, 1, 1.5 mg/kg/day). Nociception was assessed using tail flick apparatus. Tail flick latency was recorded when the rat shook its tail. For apoptosis assay other groups of rats received the above treatment and apoptosis was evaluated by in situ terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) method. Results The results showed that administration of donepezil (0.5, 1, 1.5 mg/kg, ip) delayed the morphine tolerance for 9, 12 and 17 days, respectively. Furthermore pretreatment injection of donepezil attenuated the number of apoptotic cells in the cerebral cortex and lumbar spinal cord compared to the control group. Conclusion In conclusion, we found that systemic administration of donepezil attenuated morphine-induced tolerance and apoptosis in the rat cerebral cortex and lumbar spinal cord. PMID:24455992

  10. Upregulation of Acetylcholinesterase Mediated by p53 Contributes to Cisplatin-Induced Apoptosis in Human Breast Cancer Cell

    PubMed Central

    Ye, Xiaolei; Zhang, Changsong; Chen, Yichen; Zhou, Tianbao

    2015-01-01

    Background: The expression of acetylcholinesterase (AChE) could be induced during apoptosis in various cell types. And reduced AChE expression either by siRNA could prevent apoptosis. However, the detailed mechanisms underlying the AChE regulation are largely unknown in human breast cancer cell. Material and methods: MCF-7 cells were cultured and treated by cisplatin in the absence or presence of p53 siRNA. Results: In this study, the regulation of AChE expression during apoptosis induced by cisplatin, a current used anticancer drug, was investigated in human breast cancer cell line MCF-7. Exposure of MCF-7 cells to cisplatin resulted in apoptosis in a time- and concentration-dependent manner. Meanwhile, the upregulated AChE and p53 were also observed during apoptosis. Silencing interfering RNA directed against p53 blocked the expression of AChE. Conclusion: Taken together, these results suggested that AChE expression could be upregulated by the activation of p53 during apoptosis induced by cisplatin in MCF-7 cells. PMID:25553088

  11. Targeting SLUG sensitizes leukemia cells to ADR-induced apoptosis

    PubMed Central

    Wei, Chang-Rong; Liu, Jun; Yu, Xiao-Jun

    2015-01-01

    Background and Aims: Slug is an E-cadherin repressor and a suppressor of PUMA (p53 upregulated modulator of apoptosis) and it has recently been demonstrated that Slug plays an important role in controlling apoptosis. In this study, we examined whether Slug’s ability to silence expression suppresses the growth of leukemia HL-60 cells and/or sensitizes leukemia HL-60 cells to adriamycin (ADR) through induction of apoptosis. Methods: SLUG siRNA was transfected into the HL-60 and HL-60ADR cell lines (an adriamycin resistant cell line). The stably SLUG siRNA transfected HL-60 and HL-60ADR cells was transiently transfected with PUMA siRNA. The mRNA and protein expression of SLUG and PUMA were determined by Quantitative real-time RT-PCR and Western blot assay. The effects of SLUG siRNA alone or combined with ADR or PUMA siRNA on growth and apoptosis in HL-60 and HL-60ADR cells was detected by MTT, ELISA and terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) assay. Results: The results showed that SLUG was less expressed in the HL-60 cells, and high expressed in the HL-60ADR cells. Obvious down-regulation of SLUG mRNA and protein levels and up-regulation of PUMA mRNA and protein levels after SLUG siRNA transfection was showed in the HL-60ADR cells. Treatment with ADR induced SLUG mRNA and protein in the HL-60 cells. Significant positive correlation was observed between basal SLUG mRNA and protein and ADR sensitivity. SLUG gene silencing by SLUG siRNA transfection inhibited growth and induced apoptosis, and increased ADR killing of the HL-60 and HL-60ADR cell lines. After the SLUG siRNA transfected HL-60 and HL-60ADR cells was transiently transfected with PUMA siRNA, did not increase ADR killing of the HL-60 and HL-60ADR cell lines. Conclusion: SLUG level positively correlated with sensitivity to ADR. SLUG siRNA could effectively reduce SLUG expression and induce PUMA expression and restore the drug sensitivity of resistant leukemic cells to

  12. α-Tomatine inhibits growth and induces apoptosis in HL-60 human myeloid leukemia cells.

    PubMed

    Huang, Huarong; Chen, Shaohua; Van Doren, Jeremiah; Li, Dongli; Farichon, Chelsea; He, Yan; Zhang, Qiuyan; Zhang, Kun; Conney, Allan H; Goodin, Susan; Du, Zhiyun; Zheng, Xi

    2015-06-01

    α‑Tomatine is a glycoalkaloid that occurs naturally in tomatoes (Lycopersicon esculentum). In the present study, the effects of α‑tomatine on human myeloid leukemia HL‑60 cells were investigated. Treatment of HL‑60 cells with α‑tomatine resulted in growth inhibition and apoptosis in a concentration‑dependent manner. Tomatidine, the aglycone of tomatine had little effect on the growth and apoptosis of HL‑60 cells. Growth inhibition and apoptosis induced by α‑tomatine in HL‑60 cells was partially abrogated by addition of cholesterol indicating that interactions between α‑tomatine and cell membrane‑associated cholesterol may be important in mediating the effect of α‑tomatine. Activation of nuclear factor‑κB by the phorbol ester, 12‑O‑tetradecanoylphorbol‑13‑acetate failed to prevent apoptosis in HL‑60 cells treated with α‑tomatine. In animal experiments, it was found that treatment of mice with α‑tomatine inhibited the growth of HL‑60 xenografts in vivo. Results from the present study indicated that α‑tomatine may have useful anti‑leukemia activities. PMID:25625536

  13. α-tomatine inhibits growth and induces apoptosis in HL-60 human myeloid leukemia cells

    PubMed Central

    HUANG, HUARONG; CHEN, SHAOHUA; VAN DOREN, JEREMIAH; LI, DONGLI; FARICHON, CHELSEA; HE, YAN; ZHANG, QIUYAN; ZHANG, KUN; CONNEY, ALLAN H; GOODIN, SUSAN; DU, ZHIYUN; ZHENG, XI

    2015-01-01

    α-tomatine is a glycoalkaloid that occurs naturally in tomatoes (Lycopersicon esculentum). In the present study, the effects of α-tomatine on human myeloid leukemia HL-60 cells were investigated. Treatment of HL-60 cells with α-tomatine resulted in growth inhibition and apoptosis in a concentration-dependent manner. Tomatidine, the aglycone of tomatine had little effect on the growth and apoptosis of HL-60 cells. Growth inhibition and apoptosis induced by α-tomatine in HL-60 cells was partially abrogated by addition of cholesterol indicating that interactions between α-tomatine and cell membrane-associated cholesterol may be important in mediating the effect of α-tomatine. Activation of nuclear factor-κB by the phorbol ester, 12-O-tetradecanoylphorbol-13-acetate failed to prevent apoptosis in HL-60 cells treated with α-tomatine. In animal experiments, it was found that treatment of mice with α-tomatine inhibited the growth of HL-60 xenografts in vivo. Results from the present study indicated that α-tomatine may have useful anti-leukemia activities. PMID:25625536

  14. Galangin inhibits cell invasion by suppressing the epithelial-mesenchymal transition and inducing apoptosis in renal cell carcinoma

    PubMed Central

    CAO, JINGYI; WANG, HAINAN; CHEN, FEIFEI; FANG, JIANZHENG; XU, AIMING; XI, WEI; ZHANG, SHENGLI; WU, GANG; WANG, ZENGJUN

    2016-01-01

    Galangin, a flavonoid extracted from the root of the Alpinia officinarum Hence, has been shown to have anticancer properties against several types of cancer cells. However, the influence of galangin on human renal cancer cells remains to be elucidated. In the present study, proliferation of 786-0 and Caki-1 cells was suppressed following exposure to various doses of galangin. Cell invasion and wound healing assays were used to observe the effect of galangin on invasion and migration. The results demonstrated that Galangin inhibited cell invasion by suppressing the epithelial mesenchymal transition (EMT), with an increase in the expression of E-cadherin and decreased expression levels of N-cadherin and vimentin. The apoptosis induced by galangin was analyzed by flow cytometry. The results revealed that galangin induced apoptosis in a dose-dependent manner. The accumulation of reactive oxygen species (ROS) is an important contributing factor for the apoptosis of various types of cancer cell. The dichlorofluorescein-diacetate method was used to determine the level of ROS. Galangin induced the accumulation of intracellular ROS and malondialdehyde, and decreased the activities of total antioxidant and superoxide dismutase in renal cell carcinoma cells. Galangin exerted an antiproliferative effect and inhibited renal cell carcinoma invasion by suppressing the EMT. This treatment also induced apoptosis, accompanied by the production of ROS. Therefore, the present data suggested that galangin may have beneficial effects by preventing renal cell carcinoma growth, inhibiting cell invasion via the EMT and inducing cell apoptosis. PMID:27035542

  15. Nuclear factor kappaB inhibitors induce adhesion-dependent colon cancer apoptosis: implications for metastasis.

    PubMed

    Scaife, Courtney L; Kuang, Jinqiu; Wills, Jason C; Trowbridge, D Brad; Gray, Phil; Manning, Bernadette M; Eichwald, Ernst J; Daynes, Raymond A; Kuwada, Scott K

    2002-12-01

    The transcription factor nuclear factor kappaB (NFkappaB) is constitutively active in many types of cancercells and regulates the expression of several antiapoptotic genes. Previous studies demonstrated a role for the inhibition of NFkappaB in cancer therapyusing a transgenic approach in mice. We found that NFkappaB was transiently activated much greater than background constitutive levels during colon cancer cell readhesion, which rendered the readhering colon cancer cells exquisitely susceptible to apoptosis in the presence of soluble NFkappaB inhibitors. These compounds greatly reduced colon cancer cell implantation in an in vivo seeding model of metastasis. The ability of soluble NFkappaB inhibitors to significantly induce apoptosis of readherent colon cancer cells makes them prospective candidates for preventing colon cancer metastasis.

  16. Steroid hormone 20-hydroxyecdysone promotes higher calcium mobilization to induce apoptosis.

    PubMed

    Wang, Di; Pei, Xu-Yang; Zhao, Wen-Li; Zhao, Xiao-Fan

    2016-07-01

    Calcium ions are essential secondary messengers that regulate diverse cellular processes including gene transcription, cell proliferation, and apoptosis. The steroid hormone 20-hydroxyecdysone (20E) promotes programmed cell death during insect metamorphosis, whereas juvenile hormone (JH) counteracts 20E activity to prevent metamorphosis. Both 20E and JH can induce cellular calcium increase; however, the mechanisms and physiological consequences resulting from calcium increase caused by the two counteracting hormones are unclear. Here, using Helicoverpa armigera epidermal cell line, we show that 20E via a G-protein-coupled receptor induced a major calcium rise in the cells, whereas JH via receptor tyrosine kinase induced a minor calcium increase. The calcium release-activated calcium modulator 1 (Orai1) and transient receptor potential (TRP) channels were necessary for 20E-induced rapid calcium influx. A higher calcium level was maintained in a long time and more genes including Orai1 and TRP channels showed elevated expression after the treatment of 20E than did after JH treatment. Caspase3/7 activation, cell death and pro-apoptotic gene expression were elicited by 20E induction, but not by JH. JH could repress 20E-induced calcium influx, caspase3/7 activation and gene expression. Higher calcium levels induced apoptosis. These results suggest that 20E and JH via different pathways regulate calcium mobilization and homeostasis at different levels, thus inform different gene expression and cellular responses. PMID:27209368

  17. Interferon-α and cyclooxygenase-2 inhibitor cooperatively mediates TRAIL-induced apoptosis in hepatocellular carcinoma

    SciTech Connect

    Zuo, Chaohui; Qiu, Xiaoxin; Liu, Nianli; Yang, Darong; Xia, Man; Liu, Jingshi; Wang, Xiaohong; and others

    2015-05-01

    Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality worldwide. Interferon-alpha (IFN-α) has recently been recognized to harbor therapeutic potential in the prevention and treatment of HCC, but it remains controversial as to whether IFN-α exerts direct cytotoxicity against HCC. Cyclooxygenase-2 (COX-2) is overexpressed in HCC and is considered to play a role in hepatocarcinogenesis. Therefore, we aimed to elucidate the combined effect of a COX-2 inhibitor, celecoxib, and IFN-α on in vitro growth suppression of HCC using the hepatoma cell line HLCZ01 and the in vivo nude mouse xenotransplantation model using HLCZ01 cells. Treatment with celecoxib and IFN-α synergistically inhibited cell proliferation in a dose- and time-dependent manner. Apoptosis was identified by 4',6-diamidino-2-phenylindole dihydrochloride and fluorescent staining. IFN-α upregulated the expression of TRAIL, while celecoxib increased the expression of TRAIL receptors. The combined regimen with celecoxib and IFN-α reduced the growth of xenotransplanted HCCs in nude mice. The regulation of IFN-α- and COX-2 inhibitor-induced cell death is impaired in a subset of TRAIL-resistant cells. The molecular mechanisms of HCC cells resistant to TRAIL-induced apoptosis were explored using molecular biological and immunological methods. Interferon-α and the COX-2 inhibitor celecoxib synergistically increased TRAIL-induced apoptosis in hepatocellular carcinoma. These data suggest that IFN-α and celecoxib may offer a novel role with important implications in designing new therapeutics for TRAIL-resistant tumors. - Highlights: ●The cytotoxic effect of TRAIL on a developed HCC HLCZ01 cells infected with HBV. ●IFN-α and celecoxib induced apoptosis in HLCZ01 cells infected with HBV. ●The combined regime reduced the growth of xenotransplanted HCCs in nude mice model.

  18. Pomegranate extract induces apoptosis in human prostate cancer cells by modulation of the IGF-IGFBP axis

    PubMed Central

    Koyama, Satomi; Cobb, Laura J; Mehta, Hemal H; Seeram, Navindra P.; Heber, David; Pantuck, Allan J.; Cohen, Pinchas

    2009-01-01

    The IGF axis is critical for the regulation of apoptosis in many human cancer cell lines. Recently, potent anti-tumorigenic effects of pomegranate juice and extracts have been reported. Consequently, pomegranate has potential not only as a treatment but also as a preventative measure against certain types of cancer, including prostate. In this study, we investigated the relationship between pomegranate-induced apoptosis in human prostate cancer cells and the IGF/IGFBP system. Treatment of LAPC4 prostate cancer cells with 10 μg/ml POMx, a highly potent pomegranate extract prepared from skin and arils minus seeds and standardized to ellagitannin content (37% punicalagins by HPLC), resulted in inhibition of cell proliferation and induction of apoptosis. Interestingly, co-treatment with POMx and IGFBP-3 revealed synergistic stimulation of apoptosis and additive inhibition of cell growth. Western blot analysis revealed that treatment with POMx or POMx/IGFBP-3 combination resulted in increased JNK phosphorylation, and decreased Akt and mTOR activation, consistent with a growth inhibitory, pro-apoptotic function. We also investigated the relationship between IGF-1 and pomegranate-induced apoptosis in 22RV1 prostate cancer cells. Co-treatment with 100 ng/ml IGF-1 completely blocked apoptosis induction by POMx. In contrast, IGF-I failed to inhibit POMx-induced apoptosis in R- cells, suggesting the importance of IGF-IR. POMx-treatment decreased Igf1 mRNA expression in a dose-dependent manner indicating that its actions also involve tumor-specific suppression of IGF-1. These studies revealed novel interactions between the IGF system and pomegranate-induced apoptosis. PMID:19853487

  19. 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

  20. Increased Oxidative Stress Induces Apoptosis in Human Cystic Fibrosis Cells

    PubMed Central

    Rottner, Mathilde; Tual-Chalot, Simon; Mostefai, H. Ahmed; Andriantsitohaina, Ramaroson; Freyssinet, Jean-Marie; Martínez, María Carmen

    2011-01-01

    Oxidative stress results in deleterious cell function in pathologies associated with inflammation. Here, we investigated the generation of superoxide anion as well as the anti-oxidant defense systems related to the isoforms of superoxide dismutases (SOD) in cystic fibrosis (CF) cells. Pro-apoptotic agents induced apoptosis in CF but not in control cells that was reduced by treatment with SOD mimetic. These effects were associated with increased superoxide anion production, sensitive to the inhibition of IκB-α phosphorylation, in pancreatic but not tracheal CF cells, and reduced upon inhibition of either mitochondrial complex I or NADPH oxidase. CF cells exhibited reduced expression, but not activity, of both Mn-SOD and Cu/Zn-SOD when compared to control cells. Although, expression of EC-SOD was similar in normal and CF cells, its activity was reduced in CF cells. We provide evidence that high levels of oxidative stress are associated with increased apoptosis in CFTR-mutated cells, the sources being different depending on the cell type. These observations underscore a reduced anti-oxidant defense mechanism, at least in part, via diminished EC-SOD activity and regulation of Cu/Zn-SOD and Mn-SOD expressions. These data point to new therapeutic possibilities in targeting anti-oxidant pathways to reduce oxidative stress and apoptosis in CF cells. PMID:21931865

  1. IFN-{gamma} sensitizes MIN6N8 insulinoma cells to TNF-{alpha}-induced apoptosis by inhibiting NF-{kappa}B-mediated XIAP upregulation

    SciTech Connect

    Kim, Hun Sik; Kim, Sunshin; Lee, Myung-Shik . E-mail: mslee@smc.samsung.co.kr

    2005-10-28

    Although X-linked inhibitor of apoptosis protein (XIAP) is an important intracellular suppressor of apoptosis in a variety of cell types, its role in cytokine-induced pancreatic {beta}-cell apoptosis remains unclear. Here, we found that: (i) XIAP level was inversely correlated with tumor necrosis factor (TNF)-{alpha}-induced apoptosis in MIN6N8 insulinoma cells; (ii) adenoviral XIAP overexpression abrogated the TNF-{alpha}-induced apoptosis through inhibition of caspase activity; (iii) downregulation of XIAP by antisense oligonucleotide or Smac peptide sensitized MIN6N8 cells to TNF-{alpha}-induced apoptosis; (iv) XIAP expression was induced by TNF-{alpha} through a nuclear factor-{kappa}B (NF-{kappa}B)-dependent pathway, and interferon (IFN)-{gamma} prevented such an induction in a manner independent of NF-{kappa}B, which presents a potential mechanism underlying cytotoxic IFN-{gamma}/TNF-{alpha} synergism. Taken together, our results suggest that XIAP is an important modulator of TNF-{alpha}-induced apoptosis of MIN6N8 cells, and XIAP regulation in pancreatic {beta}-cells might play an important role in pancreatic {beta}-cell apoptosis and in the pathogenesis of type 1 diabetes.

  2. 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

  3. 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

  4. The Na+/H+ Exchanger Controls Deoxycholic Acid-Induced Apoptosis by a H+-Activated, Na+-Dependent Ionic Shift in Esophageal Cells

    PubMed Central

    Goldman, Aaron; Chen, HwuDauRw; Khan, Mohammad R.; Roesly, Heather; Hill, Kimberly A.; Shahidullah, Mohammad; Mandal, Amritlal; Delamere, Nicholas A.; Dvorak, Katerina

    2011-01-01

    Apoptosis resistance is a hallmark of cancer cells. Typically, bile acids induce apoptosis. However during gastrointestinal (GI) tumorigenesis the cancer cells develop resistance to bile acid-induced cell death. To understand how bile acids induce apoptosis resistance we first need to identify the molecular pathways that initiate apoptosis in response to bile acid exposure. In this study we examined the mechanism of deoxycholic acid (DCA)-induced apoptosis, specifically the role of Na+/H+ exchanger (NHE) and Na+ influx in esophageal cells. In vitro studies revealed that the exposure of esophageal cells (JH-EsoAd1, CP-A) to DCA (0.2 mM -0.5 mM) caused lysosomal membrane perturbation and transient cytoplasmic acidification. Fluorescence microscopy in conjunction with atomic absorption spectrophotometry demonstrated that this effect on lysosomes correlated with influx of Na+, subsequent loss of intracellular K+, an increase of Ca2+ and apoptosis. However, ethylisopropyl-amiloride (EIPA), a selective inhibitor of NHE, prevented Na+, K+ and Ca2+ changes and caspase 3/7 activation induced by DCA. Ouabain and amphotericin B, two drugs that increase intracellular Na+ levels, induced similar changes as DCA (ion imbalance, caspase3/7 activation). On the contrary, DCA-induced cell death was inhibited by medium with low a Na+ concentrations. In the same experiments, we exposed rat ileum ex-vivo to DCA with or without EIPA. Severe tissue damage and caspase-3 activation was observed after DCA treatment, but EIPA almost fully prevented this response. In summary, NHE-mediated Na+ influx is a critical step leading to DCA-induced apoptosis. Cells tolerate acidification but evade DCA-induced apoptosis if NHE is inhibited. Our data suggests that suppression of NHE by endogenous or exogenous inhibitors may lead to apoptosis resistance during GI tumorigenesis. PMID:21887327

  5. Cyanidin-3-glucoside isolated from mulberry fruit protects pancreatic β-cells against oxidative stress-induced apoptosis.

    PubMed

    Lee, Jong Seok; Kim, Young Rae; Song, In Gyu; Ha, Suk-Jin; Kim, Young Eon; Baek, Nam-In; Hong, Eock Kee

    2015-02-01

    The extract obtained from berries contains high amounts of anthocyanins, and this extract is used as a phytotherapeutic agent for different types of diseases. In this study, we examined the cytoprotective effects of cyanidin-3-glucoside (C3G) isolated from mulberry fruit against pancreatic β-cell apoptosis caused by hydrogen peroxide (H2O2)-induced oxidative stress. The MIN6 pancreatic β-cells were used to investigate the cytoprotective effects of C3G on the oxidative stress-induced apoptosis of cells. Cell viability was examined by MTT assay and lipid peroxidation was assayed by thiobarbituric acid (TBA) reaction. Immunofluorescence staining, flow cytometry and western blot analysis were also used to determine apoptosis and the expression of proteins associated with apoptosis. Our results revealed that H2O2 increased the rate of apoptosis by stimulating various pro-apoptotic processes, such as the generation of intracellular reactive oxygen species (ROS), lipid peroxidation, DNA fragmentation and caspase-3 activation. However, C3G reduced the H2O2-induced cell death in the MIN6N pancreatic β-cells. In addition, we confirmed that H2O2 activated mitogen-activated protein kinases (MAPKs), such as extracellular signal-regulated kinase (ERK), c-Jun NH2-terminal kinase (JNK) and p38 MAPK. C3G inhibited the phosphorylation of ERK and p38 without inducing the phosphorylation of JNK. Furthermore, C3G regulated the intrinsic apoptotic pathway-associated proteins, such as proteins belonging to the Bcl-2 family, cytochrome c and caspase-3. Taken together, our results suggest that C3G isolated from mulberry fruit has potential for use as a phytotherapeutic agent for the prevention of diabetes by preventing oxidative stress-induced β-cell apoptosis.

  6. Hsp90 inhibitor 17-allylamino-17-demethoxygeldanamycin prevents synovial sarcoma proliferation via apoptosis in in vitro models.

    PubMed

    Terry, Jefferson; Lubieniecka, Joanna M; Kwan, Wanda; Liu, Suzanne; Nielsen, Torsten O

    2005-08-01

    Synovial sarcoma is a soft tissue malignancy with a poor prognosis; many patients will die from this disease within 10 years of diagnosis, despite treatment. Gene expression profiling and immunohistochemistry studies have identified oncogenes that are highly expressed in synovial sarcoma. Included in this group are receptor tyrosine kinases such as epidermal growth factor receptor, insulin-like growth factor receptor 1, fibroblast growth factor receptor 3, KIT, and HER2. Inhibitors of these growth-promoting receptors are likely to inhibit proliferation of synovial sarcoma; however, the effect of receptor tyrosine kinase inhibitors on synovial sarcoma is largely unknown. We assessed the ability of the following receptor tyrosine kinase inhibitors to halt proliferation and induce apoptosis in synovial sarcoma monolayer and three dimensional spheroid in vitro models: gefitinib (Iressa), NVP-AEW541, imatinib mesylate (Gleevec), SU5402, PRO-001, trastuzumab (Herceptin), and 17-allylamino-17-demethoxygeldanamycin (17-AAG). Gefitinib, NVP-AEW541, and imatinib inhibited proliferation only at relatively high concentrations, which are not clinically applicable. 17-AAG, which destabilizes multiple receptor tyrosine kinases and other oncoproteins through heat shock protein 90 inhibition, prevented proliferation and induced apoptosis in synovial sarcoma monolayer models at concentrations achievable in human serum. 17-AAG treatment was also associated with receptor tyrosine kinase degradation and induction of apoptosis in synovial sarcoma spheroid models. 17-AAG was more effective than doxorubicin, particularly in the spheroid models. Here we provide in vitro evidence that 17-AAG, a clinically applicable drug with known pharmacology and limited toxicity, inhibits synovial sarcoma proliferation by inducing apoptosis, and thus has potential as a systemic therapy for this disease.

  7. Chlorogenic acid and coffee prevent hypoxia-induced retinal degeneration.

    PubMed

    Jang, Holim; Ahn, Hong Ryul; Jo, Hyoung; Kim, Kyung-A; Lee, Eun Ha; Lee, Ki Won; Jung, Sang Hoon; Lee, Chang Y

    2014-01-01

    This study explored whether chlorogenic acid (CGA) and coffee have protective effects against retinal degeneration. Under hypoxic conditions, the viability of transformed retinal ganglion (RGC-5) cells was significantly reduced by treatment with the nitric oxide (NO) donor S-nitroso-N-acetylpenicillamine (SNAP). However, pretreatment with CGA attenuated cell death in a concentration-dependent manner. In addition, CGA prevented the up-regulation of apoptotic proteins such as Bad and cleaved caspase-3. Similar beneficial effects of both CGA and coffee extracts were observed in mice that had undergone an optic nerve crush (ONC) procedure. CGA and coffee extract reduced cell death by preventing the down-regulation of Thy-1. Our in vitro and in vivo studies demonstrated that coffee and its major component, CGA, significantly reduce apoptosis of retinal cells induced by hypoxia and NO, and that coffee consumption may help in preventing retinal degeneration. PMID:24295042

  8. Role of mitochondrial hOGG1 and aconitase in oxidant-induced lung epithelial cell apoptosis.

    PubMed

    Panduri, V; Liu, G; Surapureddi, S; Kondapalli, J; Soberanes, S; de Souza-Pinto, N C; Bohr, V A; Budinger, G R S; Schumacker, P T; Weitzman, S A; Kamp, D W

    2009-09-15

    8-Oxoguanine DNA glycosylase (Ogg1) repairs 8-oxo-7,8-dihydroxyguanine (8-oxoG), one of the most abundant DNA adducts caused by oxidative stress. In the mitochondria, Ogg1 is thought to prevent activation of the intrinsic apoptotic pathway in response to oxidative stress by augmenting DNA repair. However, the predominance of the beta-Ogg1 isoform, which lacks 8-oxoG DNA glycosylase activity, suggests that mitochondrial Ogg1 functions in a role independent of DNA repair. We report here that overexpression of mitochondria-targeted human alpha-hOgg1 (mt-hOgg1) in human lung adenocarcinoma cells with some alveolar epithelial cell characteristics (A549 cells) prevents oxidant-induced mitochondrial dysfunction and apoptosis by preserving mitochondrial aconitase. Importantly, mitochondrial alpha-hOgg1 mutants lacking 8-oxoG DNA repair activity were as effective as wild-type mt-hOgg1 in preventing oxidant-induced caspase-9 activation, reductions in mitochondrial aconitase, and apoptosis, suggesting that the protective effects of mt-hOgg1 occur independent of DNA repair. Notably, wild-type and mutant mt-hOgg1 coprecipitate with mitochondrial aconitase. Furthermore, overexpression of mitochondrial aconitase abolishes oxidant-induced apoptosis whereas hOgg1 silencing using shRNA reduces mitochondrial aconitase and augments apoptosis. These findings suggest a novel mechanism that mt-hOgg1 acts as a mitochondrial aconitase chaperone protein to prevent oxidant-mediated mitochondrial dysfunction and apoptosis that might be important in the molecular events underlying oxidant-induced toxicity. PMID:19524665

  9. Apoptosis induced by Oropouche virus infection in HeLa cells is dependent on virus protein expression.

    PubMed

    Acrani, Gustavo Olszanski; Gomes, Rogério; Proença-Módena, José Luiz; da Silva, Andrei Furlan; Carminati, Patricia Oliveira; Silva, Maria Lucia; Santos, Rodrigo Ivo Marques; Arruda, Eurico

    2010-04-01

    Oropouche (OROV) is a single-stranded RNA arbovirus of the family Bunyaviridae, genus Orthobunyavirus, which has caused over half a million cases of febrile illness in Brazil in the past 30 years. OROV fever has been registered almost exclusively in the Amazon region, but global warming, deforestation and redistribution of vectors and animal reservoirs increases the risk of Oropouche virus emergence in other areas. OROV causes a cytolytical infection in cultured cells with characteristic cytopathic effect 48h post-infection. We have studied the mechanisms of apoptosis induced by OROV in HeLa cells and found that OROV causes DNA fragmentation detectable by gel electrophoresis and by flow cytometric analysis of the Sub-G1 population at 36h post-infection. Mitochondrial release of cytochrome C and activation of caspases 9 and 3 were also detected by western blot analysis. Lack of apoptosis induced by UV-inactivated OROV reveals that virus-receptor binding is not sufficient to induce cell death. Results obtained in cells treated with chloroquine and cycloheximide indicated that viral uncoating and replication are required for apoptosis induction by OROV. Furthermore, treatment of the cells with pan-caspase inhibitor prevented OROV-induced apoptosis without affecting virus progeny production. The results show that OROV infection in vitro causes apoptosis by an intracellular pathway involving mitochondria, and activated by a mechanism dependent on viral replication and protein synthesis.

  10. Targeted inhibition of p38MAPK-enhanced autophagy in SW620 cells resistant to photodynamic therapy-induced apoptosis.

    PubMed

    Xue, Qin; Wang, Pan; Wang, Xiaobing; Zhang, Kun; Liu, Quanhong

    2015-09-01

    Photodynamic therapy (PDT) is a promising and noninvasive treatment that can induce apoptosis, autophagy, or both depending on the cell phenotype. In this work, chlorin e6 (Ce6) was used to photosensitize human colorectal cancer SW620 cells. In cells, apparent autophagy and apoptosis with dependence on intracellular reactive oxygen species (ROS) generation were detected. p38MAPK activation followed by ROS generation might be a core component in Ce6 mediate PDT (Ce6-PDT)-induced autophagy and apoptosis signaling pathway. By using p38MAPK siRNA, the results showed a marked enhancement on cell apoptosis in Ce6-PDT with increased annexin (+) apoptotic cells, nuclear condensation, caspase-3, and PARP cleavage. Besides, impairment of p38MAPK also promoted the autophagic response to photodamage as indicated by conversion of LC3 and monodansyl cadaverine (MDC) labeling patterns. It appears that Ce6-PDT induced ROS production involving activation of p38MAPK, probably to prevent SW620 cells from photodamage. Moreover, autophagy inhibitor 3-methyladenine/bafilomycin A1 greatly aggravated Ce6-PDT-induced apoptosis in SW620 cells with knockdown of p38MAPK. Taken together, this study suggests that autophagy could represent a promising field in cancer treatment and p38MAPK may be a potential therapeutic target to enhance the efficacy on clinical evaluation for the treatment of colorectal cancer. PMID:26254783

  11. Myricitrin Attenuates High Glucose-Induced Apoptosis through Activating Akt-Nrf2 Signaling in H9c2 Cardiomyocytes.

    PubMed

    Zhang, Bin; Chen, Yaping; Shen, Qiang; Liu, Guiyan; Ye, Jingxue; Sun, Guibo; Sun, Xiaobo

    2016-01-01

    Hyperglycemia, as well as diabetes mellitus, has been shown to trigger cardiac cell apoptosis. We have previously demonstrated that myricitrin prevents endothelial cell apoptosis. However, whether myricitrin can attenuate H9c2 cell apoptosis remains unknown. In this study, we established an experiment model in H9c2 cells exposed to high glucose. We tested the hypothesis that myricitrin may inhibit high glucose (HG)-induced cardiac cell apoptosis as determined by TUNEL staining. Furthermore, myricitrin promoted antioxidative enzyme production, suppressed high glucose-induced reactive oxygen species (ROS) production and decreased mitochondrial membrane potential (MMP) in H9c2 cells. This agent significantly inhibited apoptotic protein expression, activated Akt and facilitated the transcription of NF-E2-related factor 2 (Nrf2)-mediated protein (heme oxygenase-1 (HO-1) and quinone oxidoreductase 1 (NQO-1) expression as determined by Western blotting. Significantly, an Akt inhibitor (LY294002) or HO-1 inhibitor (ZnPP) not only inhibited myricitrin-induced HO-1/NQO-1 upregulation but also alleviated its anti-apoptotic effects. In summary, these observations demonstrate that myricitrin activates Nrf2-mediated anti-oxidant signaling and attenuates H9c2 cell apoptosis induced by high glucose via activation of Akt signaling. PMID:27399653

  12. Ethyl Pyruvate Prevents Methyglyoxal-Induced Retinal Vascular Injury in Rats

    PubMed Central

    Kim, Junghyun; Lee, Yun Mi; Kim, Chan-Sik; Sohn, Eunjin; Jo, Kyuhyung; Shin, So Dam; Kim, Jin Sook

    2013-01-01

    Pyruvate is an endogenous antioxidant substance. The aim of this study was to investigate the protective effects of ethyl pyruvate (EP) on retinal vascular injury in diabetic retinopathy. To investigate the protective effect of EP on vascular cell apoptosis and blood-retinal barrier (BRB) breakage, we have used intravitreally methylglyoxal-(MGO-) injected rat eyes. Apoptosis of the retinal vascular cell that was stimulated by the intravitreal injection of MGO was evidently attenuated by the EP treatment. EP exerts inhibitory effect on MGO-induced vascular cell apoptosis by blocking oxidative injury. In addition, EP treatment prevented MGO-induced BRB breakage and the degradation of occludin, an important tight junction protein. These observations suggest that EP acts through an antioxidant mechanism to protect against oxidative stress-induced apoptosis in retinal vessels. PMID:23671872

  13. Solena amplexicaulis induces cell cycle arrest, apoptosis and inhibits angiogenesis in hepatocarcinoma cells and HUVECs.

    PubMed

    Ren, Jie; Xu, Yuan Yuan; Jiang, He Fei; Yang, Meng; Huang, Qian Hui; Yang, Jie; Hu, Kun; Wei, Kun

    2014-01-01

    Solena amplexicaulis (Lam.) Gandhi (SA) has been used as a traditional medicine for the treatment of dysentery, multiple abscess, gastralgia, urethritis, and eczema in the minority area of China. This study was aimed to examine the cell proliferation inhibitory activity of the SA extract (SACE) and its mechanism of action in human hepatoma cell line (HepG2) and evaluate its anti-angiogenesis activity in human umbilical vein endothelial cell line (HUVEC). SACE could inhibit the growth of HepG2 cells in a dose- and time-dependent manner. FCM analysis showed that SACE could induce G2/M phase arrest, cell apoptosis, the mitochondrial membrane potential loss (ΔΨm) and increase the production of intracellular ROS of HepG2 cells. After treatment with SACE, topical morphological changes of apoptotic body formation, obvious increase of apoptosis-related protein expressions, such as Bax, cytochrome c, caspase-3, PARP-1, and decrease of Bcl-2, procaspase-9 protein expressions were observed at the same time. Moreover, SACE caused the significant inhibition of endothelial cell migration and tube formation in HUVEC cells. The results suggested that SACE could act as an angiogenesis inhibitor and induce cell apoptosis via a caspase-dependent mitochondrial pathway. Therefore, SACE could be a potent candidate for the prevention and treatment of liver cancer. PMID:25547924

  14. Cytoplasmic localization of p21 protects trophoblast giant cells from DNA damage induced apoptosis.

    PubMed

    de Renty, Christelle; DePamphilis, Melvin L; Ullah, Zakir

    2014-01-01

    Proliferating trophoblast stem cells (TSCs) can differentiate into nonproliferating but viable trophoblast giant cells (TGCs) that are resistant to DNA damage induced apoptosis. Differentiation is associated with selective up-regulation of the Cip/Kip cyclin-dependent kinase inhibitors p57 and p21; expression of p27 remains constant. Previous studies showed that p57 localizes to the nucleus in TGCs where it is essential for endoreplication. Here we show that p27 also remains localized to the nucleus during TSC differentiation where it complements the role of p57. Unexpectedly, p21 localized to the cytoplasm where it was maintained throughout both the G- and S-phases of endocycles, and where it prevented DNA damage induced apoptosis. This unusual status for a Cip/Kip protein was dependent on site-specific phosphorylation of p21 by the Akt1 kinase that is also up-regulated in TGCs. Although cytoplasmic p21 is widespread among cancer cells, among normal cells it has been observed only in monocytes. The fact that it also occurs in TGCs reveals that p57 and p21 serve nonredundant functions, and suggests that the role of p21 in suppressing apoptosis is restricted to terminally differentiated cells.

  15. Transduction of the TAT-FLIP fusion protein results in transient resistance to Fas-induced apoptosis in vivo.

    PubMed

    Krautwald, Stefan; Ziegler, Ekkehard; Tiede, Karen; Pust, Rainer; Kunzendorf, Ulrich

    2004-10-15

    Although tightly regulated programmed cell death (apoptosis) possesses great importance for tissue homeostasis, several pathologic processes are associated with organ failure due to adversely activated cell apoptosis. Transient increase in apoptosis has been shown to cause organ damage during fulminant hepatitis B, autoimmune diseases, ischemia-reperfusion injury, sepsis, or allograft rejection. A defined and temporary inhibition of cell apoptosis may therefore be of high clinical relevance. Activation of death receptors results in caspase-8 recruitment to the death-inducing signaling complex, which initiates the apoptotic process through cleavage of caspase-8 and downstream substrates. This initial step may be inhibited by the caspase-8 inhibitor FLIP (FLICE inhibitory protein). To specifically inhibit the initiation of death receptor-mediated apoptosis we constructed a fusion protein containing FLIP fused N-terminally to the human immunodeficiency virus TAT domain. This TAT domain allows the fusion protein to cross the cell membrane and thus makes the FLIP domain able to interfere with the death-inducing signaling complex inside of the cell. We observed that incubation of lymphocytic Jurkat or BJAB cells with TAT-FLIPS proteins significantly inhibits Fas-induced activation of procaspase-8 and downstream caspases, preventing cells from undergoing apoptosis. Systemic application of TAT-FLIPS prolongs survival and reduces multi-organ failure due to Fas-receptor-mediated lethal apoptosis in mice. Therefore, application of cellular FLIPS in the form of a TAT fusion protein may open a promising, easily applicable new tool for providing protection against transient, pathologically increased apoptosis in various diseases. PMID:15304499

  16. Radiation-Induced Autophagy Contributes to Cell Death and Induces Apoptosis Partly in Malignant Glioma Cells

    PubMed Central

    Jo, Guk Heui; Bögler, Oliver; Chwae, Yong-Joon; Yoo, Heon; Lee, Seung Hoon; Park, Jong Bae; Kim, Youn-Jae; Kim, Jong Heon; Gwak, Ho-Shin

    2015-01-01

    Purpose Radiation-induced autophagy has been shown to play two different roles, in malignant glioma (MG) cells, cytocidal or cytoprotective. However, neither the role of radiation-induced autophagy for cell death nor the existence of autophagy-induced apoptosis, a well-known cell-death pathway after irradiation, has been verified yet. Materials and Methods We observed both temporal and dose-dependent response patterns of autophagy and apoptosis to radiation in MG cell lines. Additionally, we investigated the role of autophagy in apoptosis through knockdown of autophagy-related proteins. Results Autophagic activity measured by staining of acidic vesicle organelles and Western blotting of LC-3 protein increased in proportion to radiation dose from day 1 to 5 after irradiation. Apoptosis measured by annexin-V staining and Western blotting of cleaved poly(ADP-ribose) polymerase demonstrated relatively late appearance 3 days after irradiation that increased for up to 7 days. Blocking of pan-caspase (Z-VAD-FMK) did not affect apoptosis after irradiation, but silencing of Atg5 effectively reduced radiation-induced autophagy, which decreased apoptosis significantly. Inhibition of autophagy in Atg5 knockdown cells was shown to be beneficial for cell survival. Stable transfection of GFP-LC3 cells was observed after irradiation. Annexin-V was localized in cells bearing GFP-LC3 punctuated spots, indicating autophagy in immunofluorescence. Some of these punctuated GFP-LC3 bearing cells formed conglomerated spots and died in final phase. Conclusion These findings suggest that autophagy appears earlier than apoptosis after irradiation and that a portion of the apoptotic population that appears later is autophagy-dependent. Thus, autophagy is a pathway to cell death after irradiation of MG cells. PMID:25410762

  17. Nicotinamide prevents ultraviolet radiation-induced cellular energy loss.

    PubMed

    Park, Joohong; Halliday, Gary M; Surjana, Devita; Damian, Diona L

    2010-01-01

    UV radiation is carcinogenic by causing mutations in the skin and also by suppressing cutaneous antitumor immunity. We previously found nicotinamide (vitamin B3) to be highly effective at reducing UV-induced immunosuppression in human volunteers, with microarray studies on in vivo irradiated human skin suggesting that nicotinamide normalizes subsets of apoptosis, immune function and energy metabolism-related genes that are downregulated by UV exposure. Using human adult low calcium temperature keratinocytes, we further investigated nicotinamide's effects on cellular energy metabolism. We found that nicotinamide prevented UV-induced cellular ATP loss and protected against UV-induced glycolytic blockade. To determine whether nicotinamide alters the effects of UV-induced oxidative stress posttranslationally, we also measured UV-induced reactive oxygen species (ROS). Nicotinamide had no effect on ROS formation, and at the low UV doses used in these studies, equivalent to ambient daily sun exposure, there was no evidence of apoptosis. Hence, nicotinamide appears to exert its UV protective effects on the skin via its role in cellular energy pathways.

  18. 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

  19. Single-Cell-Precision Microplasma-Induced Cancer Cell Apoptosis

    PubMed Central

    Lu, Xinpei; He, Guangyuan; Ostrikov, Kostya

    2014-01-01

    The issue of single-cell control has recently attracted enormous interest. However, in spite of the presently achievable intracellular-level physiological probing through bio-photonics, nano-probe-based, and some other techniques, the issue of inducing selective, single-cell-precision apoptosis, without affecting neighbouring cells remains essentially open. Here we resolve this issue and report on the effective single-cell-precision cancer cell treatment using the reactive chemistry of the localized corona-type plasma discharge around a needle-like electrode with the spot size ∼1 µm. When the electrode is positioned with the micrometer precision against a selected cell, a focused and highly-localized micro-plasma discharge induces apoptosis in the selected individual HepG2 and HeLa cancer cells only, without affecting any surrounding cells, even in small cell clusters. This is confirmed by the real-time monitoring of the morphological and structural changes at the cellular and cell nucleus levels after the plasma exposure. PMID:24971517

  20. Autophagy and gap junctional intercellular communication inhibition are involved in cadmium-induced apoptosis in rat liver cells

    SciTech Connect

    Zou, Hui; Zhuo, Liling; Han, Tao; Hu, Di; Yang, Xiaokang; Wang, Yi; Yuan, Yan; Gu, Jianhong; Bian, Jianchun; Liu, Xuezhong; Liu, Zongping

    2015-04-17

    Cadmium (Cd) is known to induce hepatotoxicity, yet the underlying mechanism of how this occurs is not fully understood. In this study, Cd-induced apoptosis was demonstrated in rat liver cells (BRL 3A) with apoptotic nuclear morphological changes and a decrease in cell index (CI) in a time- and concentration-dependent manner. The role of gap junctional intercellular communication (GJIC) and autophagy in Cd-induced apoptosis was investigated. Cd significantly induced GJIC inhibition as well as downregulation of connexin 43 (Cx43). The prototypical gap junction blocker carbenoxolone disodium (CBX) exacerbated the Cd-induced decrease in CI. Cd treatment was also found to cause autophagy, with an increase in mRNA expression of autophagy-related genes Atg-5, Atg-7, Beclin-1, and microtubule-associated protein light chain 3 (LC3) conversion from cytosolic LC3-I to membrane-bound LC3-II. The autophagic inducer rapamycin (RAP) prevented the Cd-induced CI decrease, while the autophagic inhibitor chloroquine (CQ) caused a further reduction in CI. In addition, CBX promoted Cd-induced autophagy, as well as changes in expression of Atg-5, Atg-7, Beclin-1 and LC3. CQ was found to block the Cd-induced decrease in Cx43 and GJIC inhibition, whereas RAP had opposite effect. These results demonstrate that autophagy plays a protective role during Cd-induced apoptosis in BRL 3A cells during 6 h of experiment, while autophagy exacerbates Cd-induced GJIC inhibition which has a negative effect on cellular fate. - Highlights: • GJIC and autophagy is crucial for biological processes. • Cd exposure causes GJIC inhibition and autophagy increase in BRL 3A cells. • Autophagy protects Cd induced BRL 3A cells apoptosis at an early stage. • Autophagy exacerbates Cd-induced GJIC inhibition. • GJIC plays an important role in autophagy induced cell death or survival.

  1. 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

  2. Deregulation of Mitochondria-Shaping Proteins Opa-1 and Drp-1 in Manganese-Induced Apoptosis

    PubMed Central

    Alaimo, Agustina; Gorojod, Roxana M.; Beauquis, Juan; Muñoz, Manuel J.; Saravia, Flavia; Kotler, Mónica L.

    2014-01-01

    Mitochondria are dynamic organelles that undergo fusion and fission processes. These events are regulated by mitochondria-shaping proteins. Changes in the expression and/or localization of these proteins lead to a mitochondrial dynamics impairment and may promote apoptosis. Increasing evidence correlates the mitochondrial dynamics disruption with the occurrence of neurodegenerative diseases. Therefore, we focused on this topic in Manganese (Mn)-induced Parkinsonism, a disorder associated with Mn accumulation preferentially in the basal ganglia where mitochondria from astrocytes represent an early target. Using MitoTracker Red staining we observed increased mitochondrial network fission in Mn-exposed rat astrocytoma C6 cells. Moreover, Mn induced a marked decrease in fusion protein Opa-1 levels as well as a dramatic increase in the expression of fission protein Drp-1. Additionally, Mn provoked a significant release of high MW Opa-1 isoforms from the mitochondria to the cytosol as well as an increased Drp-1 translocation to the mitochondria. Both Mdivi-1, a pharmacological Drp-1 inhibitor, and rat Drp-1 siRNA reduced the number of apoptotic nuclei, preserved the mitochondrial network integrity and prevented cell death. CsA, an MPTP opening inhibitor, prevented mitochondrial Δψm disruption, Opa-1 processing and Drp-1 translocation to the mitochondria therefore protecting Mn-exposed cells from mitochondrial disruption and apoptosis. The histological analysis and Hoechst 33258 staining of brain sections of Mn-injected rats in the striatum showed a decrease in cellular mass paralleled with an increase in the occurrence of apoptotic nuclei. Opa-1 and Drp-1 expression levels were also changed by Mn-treatment. Our results demonstrate for the first time that abnormal mitochondrial dynamics is implicated in both in vitro and in vivo Mn toxicity. In addition we show that the imbalance in fusion/fission equilibrium might be involved in Mn-induced apoptosis. This knowledge may

  3. Pathway-Specific Effect of Caffeine on Protection against UV Irradiation–Induced Apoptosis in Corneal Epithelial Cells

    PubMed Central

    Wang, Ling; Lu, Luo

    2007-01-01

    Purpose To define the role of molecular interaction between the UV-induced JNK (c-Jun N-terminal kinase) cascade and corneal epithelial cell apoptosis and protection against apoptosis by caffeine. Methods Rabbit and human corneal epithelial cells were cultured in DMEM/F12 medium containing 10% FBS and 5 μg/mL insulin at 37°C in 5% CO2. DNA fragmentation and ethidium bromide/acridine orange (EB/AO) nuclear staining were performed to detect cell death. Western blot, immunoprecipitation, and kinase assays were used to measure UV-induced mitogen-activated protein (MAP) kinase activity. Results UV irradiation–induced apoptosis through apoptosis signal-regulating kinase 1 (ASK1) and MAKK4 (SEK1) upstream from JNK was caffeine sensitive. Caffeine (1,3,7-trimethylxanthine), an agent that is one of the most popular additions to food consumed in the world and a potential enhancer of chemotherapy, effectively protected corneal epithelial cells against apoptosis by its specific effect on the JNK cascade. Theophylline (1,3-dimethylxanthine) exhibited an effect similar to that of caffeine on prevention of UV irradiation–induced apoptosis. However, alterations of either intracellular cAMP or Ca2+ levels did not alter the effect of caffeine on the JNK signaling pathway. In addition, the blockade of PI3K-like kinases by wortmannin had no impact on the protective effect of caffeine against UV irradiation–induced apoptosis, suggesting that the protective effect of caffeine acts through a specific mechanism involving UV irradiation–induced activation of ASK1 and SEK1. In contrast, caffeine had no effects on melphalan-, hyperosmotic stress–, or IL-1 β-induced activation of the JNK signaling pathway in these cells. Conclusions UV irradiation stress–induced activation of the ASK1-SEK1-JNK signaling pathway leading to apoptosis is a caffeine-sensitive process, and caffeine, as a multifunctional agent in cells, can specifically interact with the pathway to protect against

  4. Protection against TNF-induced liver parenchymal cell apoptosis during endotoxemia by a novel caspase inhibitor in mice.

    PubMed

    Jaeschke, H; Farhood, A; Cai, S X; Tseng, B Y; Bajt, M L

    2000-11-15

    Excessive apoptotic cell death is implicated in a growing number of acute and chronic disease states. Caspases are critical for the intracellular signaling pathway leading to apoptosis. The aim of this investigation was to evaluate the efficacy and the mechanism of action of the novel caspase inhibitor CV1013 in a well-characterized model of TNF-induced apoptosis. Administration of 700 mg/kg galactosamine/100 microg/kg endotoxin (Gal/ET) induced hepatocellular apoptosis in C3Heb/FeJ mice as indicated by increased caspase-3 activity (706% above controls) and enhanced DNA fragmentation (3400% above controls) at 6 h. In addition, apoptosis was aggravated by the neutrophil-induced injury at 7 h (ALT activities: 4220 +/- 960 U/L and 48 +/- 4% necrosis). All animals died 8-12 h after Gal/ET treatment from shock and liver failure. A dose of 10 or 1 mg/kg of CV1013 administered three times (3, 4.5, and 5.5 h after Gal/ET) effectively prevented caspase-3 activation and parenchymal cell apoptosis at 6 h as well as the subsequent neutrophil-induced aggravation of the injury at 7 h after Gal/ET treatment. Animals treated with 10 mg/kg CV1013 survived for 24 h without liver injury. CV1013 reduced the processing of caspase-3 and caspase-8. This suggests that CV1013 may have inhibited the small amount of active caspase-8 generated at the receptor level. Because of the multiple amplification loops used to activate the entire caspase cascade, blocking the initial intracellular signal by CV1013 was highly effective in preventing apoptotic cell death. CV1013 has therapeutic potential for disease states with excessive apoptosis.

  5. Inducible resistance to Fas-mediated apoptosis in B cells.

    PubMed

    Rothstein, T L

    2000-12-01

    Apoptosis produced in B cells through Fas (APO-1, CD95) triggering is regulated by signals derived from other surface receptors: CD40 engagement produces upregulation of Fas expression and marked susceptibility to Fas-induced cell death, whereas antigen receptor engagement, or IL-4R engagement, inhibits Fas killing and in so doing induces a state of Fas-resistance, even in otherwise sensitive, CD40-stimulated targets. Surface immunoglobulin and IL-4R utilize at least partially distinct pathways to produce Fas-resistance that differentially depend on PKC and STAT6, respectively. Further, surface immunoglobulin signaling for inducible Fas-resistance bypasses Btk, requires NF-kappaB, and entails new macromolecular synthesis. Terminal effectors of B cell Fas-resistance include the known anti-apoptotic gene products, Bcl-xL and FLIP, and a novel anti-apoptotic gene that encodes FAIM (Fas Apoptosis Inhibitory Molecule). faim was identified by differential display and exists in two alternatively spliced forms; faim-S is broadly expressed, but faim-L expression is tissue-specific. The FAIM sequence is highly evolu- tionarily conserved, suggesting an important role for this molecule throughout phylogeny. Inducible resistance to Fas killing is hypothesized to protect foreign antigen-specific B cells during potentially hazardous interactions with FasL-bearing T cells, whereas autoreactive B cells fail to become Fas-resistant and are deleted via Fas-dependent cytotoxicity. Inadvertent or aberrant acquisition of Fas-resistance may permit autoreactive B cells to escape Fas deletion, and malignant lymphocytes to impede anti-tumor immunity.

  6. Effect of glutathione depletion on apoptosis induced by thiram in Chinese hamster fibroblasts.

    PubMed

    Grosicka, E; Sadurska, B; Szumiło, M; Grzela, T; Łazarczyk, P; Niderla-Bielińska, J; Rahden-Staroń, I

    2005-12-01

    Fungicide thiram, which is also known as an inducer of allergic contact dermatitis (ACD), was used as a model compound of thiuram chemicals, and its cellular effects were investigated in cultured Chinese hamster V79 cells. The level of intracellular reduced glutathione (GSH), protein sulfhydryl (PSH) groups, protein carbonyls (PC), membrane lipid peroxidation reflected by enhanced thiobarbituric acid reactive substrates (TBARS) production, as well as apoptotic effect were determined. The apoptosis induction was determined by assessing DNA fragmentation by TUNEL, annexin V binding, and caspases activation assays, using fluorescent microscope or flow cytometry, respectively. The concentrations of thiram required to induce cellular GSH depletion (by 40-50%), protein, and membrane lipid peroxidation (2-fold, and 1.7-fold, respectively), as well as to induce apoptosis in V79 Chinese hamster fibroblasts without causing necrosis through cytotoxic effects were between 50-100 microM. To investigate the role of decreased GSH content in the toxicity of thiram, GSH level was modified prior to exposure. Pretreatment of V79 cells with N-acetyl-L-cysteine (NAC), a GSH biosynthesis precursor, prevented GSH decrease, PC and TBARS production, as well as caspases activation induced by thiram exposure. On the other hand, thiram effects were enhanced by the previous depletion of cellular GSH by L-buthionine-(S,R)-sulfoximine (BSO).

  7. Dihydroartemisinin induces apoptosis in colorectal cancer cells through the mitochondria-dependent pathway.

    PubMed

    Lu, Min; Sun, Luhaoran; Zhou, Jin; Yang, Jing

    2014-06-01

    Dihydroartemisinin (DHA), a semisynthetic derivative of artemisinin isolated from the traditional Chinese herb Artemisia annua, has been shown to exhibit antitumor activity in various cancer cells, including colorectal cancer. However, the detailed mechanisms underlying its antitumor activity in colorectal cancer remain to be elucidated. In the present study, we investigated DHA-induced apoptosis in human colorectal cancer HCT-116 cells in vitro. The results showed that DHA treatment significantly reduced cell viability in a concentration- and time-dependent manner. Furthermore, DHA induced G1 cell cycle arrest, apoptotic cell death, and accumulation of reactive oxygen species (ROS). We also found that DHA decreased the mitochondrial membrane potential; activated the caspase-3, caspase-8, and caspase-9; and increased the ratio of Bax/Bcl-2. Meanwhile, the translocation of apoptotic inducing factor (AIF) and the release of cytochrome c from the mitochondria were observed. Strikingly, the free radical scavenger N-acetylcysteine or the caspase-3 inhibitor Ac-DEVD-CHO significantly prevented DHA-induced apoptotic cell death. Taken together, we concluded that DHA-triggered apoptosis in HCT-116 cells occurs through the ROS-mediated mitochondria-dependent pathway. Our data suggest that DHA has great potential to be developed as a novel therapeutic agent for the treatment of human colorectal cancer. PMID:24519064

  8. BID-induced structural changes in BAK promote apoptosis

    PubMed Central

    Moldoveanu, Tudor; Grace, Christy R.; Llambi, Fabien; Nourse, Amanda; Fitzgerald, Patrick; Gehring, Kalle; Kriwacki, Richard W.; Green, Douglas R.

    2013-01-01

    The BCL-2 family protein BAK is responsible for mitochondrial outer membrane permeabilization (MOMP), which leads to apoptosis. The BCL-2 homology (BH) 3-only protein BID activates BAK to perform this function. We report the NMR solution structure of the human BID BH3–BAK complex, which identified the activation site at the canonical BH3-binding groove of BAK. Mutating the BAK BH1 in the groove prevented activation and MOMP but not the binding of BID. BAK BH3 mutations allowed BID binding and activation but blunted function by blocking BAK oligomerization. BAK activation follows a “hit-and-run” mechanism whereby BID dissociates from the trigger site allowing BAK oligomerization at an overlapping interface. In contrast, the BH3-only proteins NOXA and BAD are predicted to clash with the trigger site, and are not activators of BAK. These findings provide insights into the early stages of BAK activation. PMID:23604079

  9. Maduramicin Inhibits Proliferation and Induces Apoptosis in Myoblast Cells

    PubMed Central

    Chen, Xin; Gu, Ying; Singh, Karnika; Shang, Chaowei; Barzegar, Mansoureh; Jiang, Shanxiang; Huang, Shile

    2014-01-01

    Maduramicin, a polyether ionophore antibiotic derived from the bacterium Actinomadura yumaensis, is currently used as a feed additive against coccidiosis in poultry worldwide. It has been clinically observed that maduramicin can cause skeletal muscle and heart cell damage, resulting in skeletal muscle degeneration, heart failure, and even death in animals and humans, if improperly used. However, the mechanism of its toxic action in myoblasts is not well understood. Using mouse myoblasts (C2C12) and human rhabdomyosarcoma (RD and Rh30) cells as an experimental model for myoblasts, here we found that maduramicin inhibited cell proliferation and induced cell death in a concentration-dependent manner. Further studies revealed that maduramicin induced accumulation of the cells at G0/G1 phase of the cell cycle, and induced apoptosis in the cells. Concurrently, maduramicin downregulated protein expression of cyclin D1, cyclin-dependent kinases (CDK4 and CDK6), and CDC25A, and upregulated expression of the CDK inhibitors (p21Cip1 and p27Kip1), resulting in decreased phosphorylation of Rb. Maduramicin also induced expression of BAK, BAD, DR4, TRADD and TRAIL, leading to activation of caspases 8, 9 and 3 as well as cleavage of poly ADP ribose polymerase (PARP). Taken together, our results suggest that maduramicin executes its toxicity in myoblasts at least by inhibiting cell proliferation and inducing apoptotic cell death. PMID:25531367

  10. Dill (Anethum graveolens L.) seed essential oil induces Candida albicans apoptosis in a metacaspase-dependent manner.

    PubMed

    Chen, Yuxin; Zeng, Hong; Tian, Jun; Ban, Xiaoquan; Ma, Bingxin; Wang, Youwei

    2014-04-01

    Dill (Anethum graveolens L.) has been used in traditional Uighur medicine for its various pharmacological activities. Previous studies have suggested that dill seed essential oil (DSEO) has anti-Candida potential and the mechanism of its action also has been studied. Our study examined whether DSEO induces apoptosis in the human pathogen Candida albicans ATCC 64550. Our results indicate that C. albicans ATCC 64550 cells treated with DSEO show some typical apoptosis characters, such as decrease in adenosine triphosphatase (ATPase) activity, chromatin condensation, nuclear fragmentation, and phosphatidylserine (PS) exposure. The DSEO promoted cytochrome c (cyt c) release and metacaspase activation, which resulted in C. albicans ATCC 64550 apoptosis. L-cysteine prevented the DSEO-induced nuclear fragmentation, PS externalization, and metacaspase activation, thus indicating that the reactive oxygen species (ROS) is an important mediator of DSEO-induced apoptosis. To our knowledge, this study is the first to report the induction of apoptosis of this pathogen with concomitant metacaspase activation by DSEO. PMID:24742834

  11. β-Arrestin2 encourages inflammation-induced epithelial apoptosis through ER stress/PUMA in colitis.

    PubMed

    Zeng, L X; Tao, J; Liu, H L; Tan, S W; Yang, Y D; Peng, X J; Liu, Z H; Jiang, J; Wu, B

    2015-05-01

    β-Arrestins (β-arrs) are regulators and mediators of G protein-coupled receptor signaling, and accumulating evidence suggests that they are functionally involved in inflammation and autoimmune diseases. However, the effect of β-arrs is unclear in inflammatory bowel disease (IBD), and the role of β-arr2 is unknown in ulcerative colitis (UC) and Crohn's disease (CD). The aim of this study is to investigate whether β-arr2 encourages inflammation-induced epithelial apoptosis through endoplasmic reticulum (ER) stress/p53-upregulated modulator of apoptosis (PUMA) in colitis. In the present study, the results showed that β-arr2 was increased in specimens from patients with UC or CD. Furthermore, a β-arr2 deficiency significantly repressed intestinal inflammation, ameliorated colitis, and alleviated mucosal apoptosis in mice. In addition, the targeted deletion of β-arr2 depressed ER stress, inhibited PUMA, and downregulated PUMA-mediated mitochondrial apoptotic signaling in colitis. β-Arr2, an important modulator of G protein-coupled receptor function, binds eIF2α to activate ER stress signaling. Furthermore, the knockdown of PUMA dramatically prevented β-arr2-induced apoptosis via alleviating ER stress in vitro. The results suggest that β-arr2 encourages inflammation-induced epithelial apoptosis through ER stress/PUMA in colitis and that β-arr2 is a potential therapeutic target for colitis.

  12. Sulforaphane induces apoptosis in adipocytes via Akt/p70s6k1/Bad inhibition and ERK activation.

    PubMed

    Yao, Anjun; Shen, Yingzhuo; Wang, Anshi; Chen, Shiyong; Zhang, Huiqin; Chen, Fen; Chen, Zhongming; Wei, Hua; Zou, Zuquan; Shan, Yujuan; Zhang, Xiaohong

    2015-10-01

    Sulforaphane (SFN), an isothiocyanate isolated from cruciferous vegetables, possesses anti-oxidant and anti-cancer bioactivities. Moreover, SFN exerts its pro-apoptotic effects in some cancer lines. However, the effects and mechanisms of SFN on the regulation of apoptosis of adipocytes are still unknown. In this study, we found that SFN induced significant apoptosis in 3T3-L1 adipocytes and markedly decreased the cellular lipid content. Western blot demonstrated that SFN-induced apoptosis was mediated via the mitochondrial apoptosis pathway based on increased cleavage of poly-ADP-ribose-polymerase (PARP), release of cytochrome c into the cytoplasm, and activation of caspase-3, as well as decreased Bcl-2/Bax ratio. In addition, SFN markedly decreased phosphorylation of Akt and downstream proteins, p70s6k1 and Bad, and increased phosphorylation of ERK. Therefore, our findings clarified that SFN could induce 3T3-L1 adipocyte apoptosis via down-regulation of the Akt/p70s6k1/Bad pathway and up-regulation of the ERK pathway, suggesting SFN may be a promising agent for the treatment or prevention of obesity.

  13. HIV-1 Vpr-Induced Apoptosis Is Cell Cycle Dependent and Requires Bax but Not ANT

    PubMed Central

    Andersen, Joshua L; DeHart, Jason L; Zimmerman, Erik S; Ardon, Orly; Kim, Baek; Jacquot, Guillaume; Benichou, Serge; Planelles, Vicente

    2006-01-01

    The HIV-1 accessory protein viral protein R (Vpr) causes G2 arrest and apoptosis in infected cells. We previously identified the DNA damage–signaling protein ATR as the cellular factor that mediates Vpr-induced G2 arrest and apoptosis. Here, we examine the mechanism of induction of apoptosis by Vpr and how it relates to induction of G2 arrest. We find that entry into G2 is a requirement for Vpr to induce apoptosis. We investigated the role of the mitochondrial permeability transition pore by knockdown of its essential component, the adenine nucleotide translocator. We found that Vpr-induced apoptosis was unaffected by knockdown of ANT. Instead, apoptosis is triggered through a different mitochondrial pore protein, Bax. In support of the idea that checkpoint activation and apoptosis induction are functionally linked, we show that Bax activation by Vpr was ablated when ATR or GADD45α was knocked down. Certain mutants of Vpr, such as R77Q and I74A, identified in long-term nonprogressors, have been proposed to inefficiently induce apoptosis while activating the G2 checkpoint in a normal manner. We tested the in vitro phenotypes of these mutants and found that their abilities to induce apoptosis and G2 arrest are indistinguishable from those of HIV-1NL4–3 vpr, providing additional support to the idea that G2 arrest and apoptosis induction are mechanistically linked. PMID:17140287

  14. Prevention of chemotherapy-induced ovarian damage.

    PubMed

    Roness, Hadassa; Kashi, Oren; Meirow, Dror

    2016-01-01

    Recent advances in our understanding of the mechanisms underlying the impact of cytotoxic drugs on the ovary have opened up new directions for the protection of the ovary from chemotherapy-induced damage. These advances have spurred the investigation of pharmacological agents to prevent ovarian damage at the time of treatment. Prevention of ovarian damage and follicle loss would provide significant advantages over existing fertility preservation techniques. This manuscript reviews new methods for the prevention of chemotherapy-induced ovarian damage, including agents that act on the PI3K/PTEN/Akt follicle activation pathway, apoptotic pathways, the vascular system, and other potential methods of reducing chemotherapy-induced ovotoxicity.

  15. [Advances in Parvovirus Non-structural Protein NS1 Induced Apoptosis].

    PubMed

    Tu, Mengyu; Liu, Fei; Chen, Shun; Wang, Mingshu; Cheng, Anchun

    2015-11-01

    Until now, more than seventeen parvovirus have been reported which can infect mammals and poultries. The infected cells appeared different properties of apoptosis and death, present a typical cytopathic effect. NS1 is a major nonstructural protein of parvovirus, with a conservative structure and function, which plays an important role in the viral life cycle. In addition to the influence on viral replication, the NS1 also participates in apoptosis induced by viruses. Parvovirus induced apoptosis which is mainly mediated by mitochondrial pathway, this review summarized the latest research progresses of parvovirus induced apoptosis.

  16. Dolichyl phosphate, a potent inducer of apoptosis in rat glioma C6 cells.

    PubMed

    Yasugi, E; Yokoyama, Y; Seyama, Y; Kano, K; Hayashi, Y; Oshima, M

    1995-11-22

    Exposure of rat glioma C6 cells to dolichyl phosphate resulted in cell shrinkage followed by nuclear fragmentation and internucleosomal cleavage of genomic DNA, yielding ladder patterns of oligonucleosomal fragments, all characteristics of apoptosis. This phenomenon occurred in a dose and time dependent manner. Dolichol and prenol failed to induce apoptosis. The inhibitors of N-glycosylation, tunicamycin and swainsonine had no apparent effect on dolichyl phosphate-induced apoptosis. Apoptotic changes were also observed in HL-60 cells, SIRC cells and HeLa cells. Thus, dolichyl phosphate functions as a potential apoptosis inducer as well as an essential carrier lipid in the biosynthesis of N-linked glycoprotein.

  17. CSE1L/CAS, a microtubule-associated protein, inhibits taxol (paclitaxel)-induced apoptosis but enhances cancer cell apoptosis induced by various chemotherapeutic drugs.

    PubMed

    Liao, Ching-Fong; Luo, Shue-Fen; Shen, Tzu-Yun; Lin, Chin-Huang; Chien, Jung-Tsun; Du, Shin-Yi; Jiang, Ming-Chung

    2008-03-31

    CSE1L/CAS, a microtubule-associated, cellular apoptosis susceptibility protein, is highly expressed in various cancers. Microtubules are the target of paclitaxel-induced apoptosis. We studied the effects of increased or reduced CAS expression on cancer cell apoptosis induced by chemotherapeutic drugs including paclitaxel. Our results showed that CAS overexpression enhanced apoptosis induced by doxorubicin, 5-fluorouracil, cisplatin, and tamoxifen, but inhibited paclitaxel-induced apoptosis of cancer cells. Reductions in CAS produced opposite results. CAS overexpression enhanced p53 accumulation induced by doxorubicin, 5-fluorouracil, cisplatin, tamoxifen, and etoposide. CAS was associated with alpha-tubulin and beta-tubulin and enhanced the association between alpha-tubulin and beta-tubulin. Paclitaxel can induce G2/M phase cell cycle arrest and microtubule aster formation during apoptosis induction, but CAS overexpression reduced paclitaxel-induced G2/M phase cell cycle arrest and microtubule aster formation. Our results indicate that CAS may play an important role in regulating the cytotoxicities of chemotherapeutic drugs used in cancer chemotherapy against cancer cells.

  18. A Mechanism of Male Germ Cell Apoptosis Induced by Bisphenol-A and Nonylphenol Involving ADAM17 and p38 MAPK Activation

    PubMed Central

    Moreno, Ricardo D.

    2014-01-01

    Germ cell apoptosis regulation is pivotal in order to maintain proper daily sperm production. Several reports have shown that endocrine disruptors such as Bisphenol-A (BPA) and Nonylphenol (NP) induce germ cell apoptosis along with a decrease in sperm production. Given their ubiquitous distribution in plastic products used by humans it is important to clarify their mechanism of action. TACE/ADAM17 is a widely distributed extracellular metalloprotease and participates in the physiological apoptosis of germ cells during spermatogenesis. The aims of this work were: 1) to determine whether BPA and NP induce ADAM17 activation; and 2) to study whether ADAM17 and/or ADAM10 are involved in germ cell apoptosis induced by BPA and NP in the pubertal rat testis. A single dose of BPA or NP (50 mg/kg) induces germ cell apoptosis in 21-day-old male rats, which was prevented by a pharmacological inhibitor of ADAM17, but not by an inhibitor of ADAM10. In vitro, we showed that BPA and NP, at similar concentrations to those found in human samples, induce the shedding of exogenous and endogenous (TNF-α) ADAM17 substrates in primary rat Sertoli cell cultures and TM4 cell line. In addition, pharmacological inhibitors of metalloproteases and genetic silencing of ADAM17 prevent the shedding induced in vitro by BPA and NP. Finally, we showed that in vivo BPA and NP induced early activation (phosphorylation) of p38 MAPK and translocation of ADAM17 to the cell surface. Interestingly, the inhibition of p38 MAPK prevents germ cell apoptosis and translocation of ADAM17 to the cell surface. These results show for the first time that xenoestrogens can induce activation of ADAM17 at concentrations similar to those found in human samples, suggesting a mechanism by which they could imbalance para/juxtacrine cell-to-cell-communication and induce germ cell apoptosis. PMID:25474107

  19. FAT10: a Novel Mediator of Vpr-Induced Apoptosis in Human Immunodeficiency Virus-Associated Nephropathy▿

    PubMed Central

    Snyder, Alexandra; Alsauskas, Zygimantas; Gong, Pengfei; Rosenstiel, Paul E.; Klotman, Mary E.; Klotman, Paul E.; Ross, Michael J.

    2009-01-01

    Human immunodeficiency virus (HIV)-associated nephropathy is a significant cause of morbidity and mortality in HIV-infected persons. Vpr-induced cell cycle dysregulation and apoptosis of renal tubular epithelial cells are important components of the pathogenesis of HIV-associated nephropathy (HIVAN). FAT10 is a ubiquitin-like protein that is upregulated in renal tubular epithelial cells in HIVAN. In these studies, we report that Vpr induces increased expression of FAT10 in tubular cells and that inhibition of FAT10 expression prevents Vpr-induced apoptosis in human and murine tubular cells. Moreover, we found that Vpr interacts with FAT10 and that these proteins colocalize at mitochondria. These studies establish FAT10 as a novel mediator of Vpr-induced cell death. PMID:19726511

  20. β-Arrestin1 inhibits chemotherapy-induced intestinal stem cell apoptosis and mucositis

    PubMed Central

    Zhan, Y; Xu, C; Liu, Z; Yang, Y; Tan, S; Yang, Y; Jiang, J; Liu, H; Chen, J; Wu, B

    2016-01-01

    The mechanism of chemotherapy-induced gastrointestinal (GI) syndrome (CIGIS) is still controversial, and it is unclear whether chemotherapy induces intestinal stem cell (ISC) apoptosis. β-Arrestins are regulators and mediators of G protein-coupled receptor signaling in cell apoptosis, division and growth. In this study, we aimed to investigate whether chemotherapy induces ISC apoptosis to contribute to mucositis in CIGIS and whether β-arrestin1 (β-arr1) is involved in this apoptosis. Different chemotherapeutic agents were used to generate a CIGIS model. Lgr5-EGFP-IRES-creERT2+/− knock-in mice were used as a CIGIS model to investigate ISC apoptosis. β-arr1 knockout mice were used to determine whether β-arr1 is involved in the apoptosis in CIGIS. Intestinal histology was performed, the ISC apoptosis was analyzed and the mucosal barrier was examined. The effects of β-arr1 in apoptosis were investigated in the samples from humans and mice as well as in cell lines. Here, we demonstrate that chemotherapy induced intestinal mucositis by promoting crypt cell apoptosis, especially in Lgr5+ stem cells and Paneth cells but not in goblet cells, epithelial cells or vascular endothelial cells. Furthermore, β-arr1 deficiency exacerbated the Lgr5+ stem cell apoptosis, but not Paneth cell apoptosis, in CIGIS. In addition, the data showed that β-arr1 reduced the chemotherapy-induced Lgr5+ stem cell apoptosis by inhibiting endoplasmic reticulum stress-mediated mitochondrial apoptotic signaling. Our study indicates that β-arr1 inhibits chemotherapy-induced ISC apoptosis to alleviate intestinal mucositis in CIGIS. PMID:27195676

  1. Endonucleases induced TRAIL-insensitive apoptosis in ovarian carcinoma cells

    SciTech Connect

    Geel, Tessa M.; Meiss, Gregor; Gun, Bernardina T. van der; Kroesen, Bart Jan; Leij, Lou F. de; Zaremba, Mindaugas; Silanskas, Arunas; Kokkinidis, Michael; Ruiters, Marcel H.; McLaughlin, Pamela M.; Rots, Marianne G.

    2009-09-10

    TRAIL induced apoptosis of tumor cells is currently entering phase II clinical settings, despite the fact that not all tumor types are sensitive to TRAIL. TRAIL resistance in ovarian carcinomas can be caused by a blockade upstream of the caspase 3 signaling cascade. We explored the ability of restriction endonucleases to directly digest DNA in vivo, thereby circumventing the caspase cascade. For this purpose, we delivered enzymatically active endonucleases via the cationic amphiphilic lipid SAINT-18{sup Registered-Sign }:DOPE to both TRAIL-sensitive and insensitive ovarian carcinoma cells (OVCAR and SKOV-3, respectively). Functional nuclear localization after delivery of various endonucleases (BfiI, PvuII and NucA) was indicated by confocal microscopy and genomic cleavage analysis. For PvuII, analysis of mitochondrial damage demonstrated extensive apoptosis both in SKOV-3 and OVCAR. This study clearly demonstrates that cellular delivery of restriction endonucleases holds promise to serve as a novel therapeutic tool for the treatment of resistant ovarian carcinomas.

  2. Cigarette smoke extract immobilizes human spermatozoa and induces sperm apoptosis.

    PubMed

    Calogero, Aldo; Polosa, Riccardo; Perdichizzi, Anna; Guarino, Francesca; La Vignera, Sandro; Scarfia, Alessia; Fratantonio, Enza; Condorelli, Rosita; Bonanno, Oriana; Barone, Nunziata; Burrello, Nunziatina; D'Agata, Rosario; Vicari, Enzo

    2009-10-01

    Cigarette smoking by the male partner adversely affects assisted reproductive techniques, suggesting that it may damage sperm chromatin/DNA and consequently embryo development. The effects of graded concentrations of research cigarettes smoke extract (CSE) on motility, mitochondrial membrane potential (MMP), chromatin integrity and apoptosis were evaluated in spermatozoa obtained from 13 healthy, non-smoking men with normal sperm parameters, by flow cytometry. CSE suppressed sperm motility in a concentration- and time-dependent manner and increased the number of spermatozoa with low MMP, the main source of energy for sperm motility. In addition, CSE had a detrimental effect on sperm chromatin condensation and apoptosis. Indeed, it increased the number of spermatozoa with phosphatidylserine externalization, an early apoptotic sign, and fragmented DNA, a late apoptotic sign, in a concentration- and time-dependent manner. These effects of CSE were of similar or even greater magnitude to those obtained following incubation with tumour necrosis factor-alpha, a cytokine known for its negative impact on sperm function, used as positive control. Since transmission of smoking-induced sperm DNA alterations has been found in pre-implantation embryos, and this may predispose offspring to a greater risk of malformations, cancer and genetic diseases, men seeking to father a child are recommended to give up smoking.

  3. Humid heat exposure induced oxidative stress and apoptosis in cardiomyocytes through the angiotensin II signaling pathway.

    PubMed

    Wang, Xiaowu; Yuan, Binbin; Dong, Wenpeng; Yang, Bo; Yang, Yongchao; Lin, Xi; Gong, Gu

    2015-05-01

    Exposure to humid heat stress leads to the initiation of serious physiological dysfunction that may result in heat-related diseases, including heat stroke, heat cramp, heat exhaustion, and even death. Increasing evidences have shown that the humid heat stress-induced dysfunction of the cardiovascular system was accompanied with severe cardiomyocyte injury; however, the precise mechanism of heat stress-induced injury of cardiomyocyte remains unknown. In the present study, we hypothesized that humid heat stress promoted oxidative stress through the activation of angiotensin II (Ang II) in cardiomyocytes. To test our hypothesis, we established mouse models of humid heat stress. Using the animal models, we found that Ang II levels in serum were significantly up-regulated and that the Ang II receptor AT1 was increased in cardiomyocytes. The antioxidant ability in plasma and heart tissues which was detected by the ferric reducing/antioxidant power assay was also decreased with the increased ROS production under humid heat stress, as was the expression of antioxidant genes (SOD2, HO-1, GPx). Furthermore, we demonstrated that the Ang II receptor antagonist, valsartan, effectively relieved oxidative stress, blocked Ang II signaling pathway and suppressed cardiomyocyte apoptosis induced by humid heat stress. In addition, overexpression of antioxidant genes reversed cardiomyocyte apoptosis induced by Ang II. Overall, these results implied that humid heat stress increased oxidative stress and caused apoptosis of cardiomyocytes through the Ang II signaling pathway. Thus, targeting the Ang II signaling pathway may provide a promising approach for the prevention and treatment of cardiovascular diseases caused by humid heat stress.

  4. Protective effects of cynaroside against H₂O₂-induced apoptosis in H9c2 cardiomyoblasts.

    PubMed

    Sun, Xiao; Sun, Gui-Bo; Wang, Min; Xiao, Jing; Sun, Xiao-Bo

    2011-08-01

    Flavonoids with potent anti-oxidative effects are the major effective components in traditional herbal medicine used in treating cardiovascular diseases. Cynaroside is a flavonoid compound that exhibits anti-oxidative capabilities. However, little is known about its effect on oxidative injury to cardiac myocytes and the underlying mechanisms. This study was designed to investigate the protective effects of cynaroside against H(2) O(2) -induced apoptosis in H9c2 cardiomyoblasts. H9c2 cells were pretreated with cynaroside for 4 h before exposure to 150 µM H(2) O(2) for 6  h. H(2) O(2) treatment caused severe injury to the H9c2 cells, which was accompanied by apoptosis, as revealed by analysis of cell nuclear morphology, through Annexin V FITC/PI staining and caspase proteases activation. Cynaroside pretreatment significantly reduced the apoptotic rate by enhancing the endogenous anti-oxidative activity of superoxide dismutase, glutathione peroxidase, and catalase, thereby inhibiting intracellular reactive oxygen species (ROS) generation. Moreover, cynaroside moderated H(2) O(2) -induced disruption of mitochondrial membrane potential, increased the expression of anti-apoptotic protein Bcl-2 while decreased the expression of pro-apoptotic protein Bax, and thereby inhibited the release of apoptogenic factors (cytochrome c and smac/Diablo) from mitochondria in H9c2 cells. Our data also demonstrated that cynaroside pretreatment showed an inhibitory effect on the H(2) O(2) -induced increase in c-Jun N-terminal kinase (JNK) and P53 protein expression. These results suggest that cynaroside prevents H(2) O(2) -induced apoptosis in H9c2 cell by reducing the endogenous production of ROS, maintaining mitochondrial function, and modulating the JNK and P53 pathways.

  5. Protective effects of cynaroside against H₂O₂-induced apoptosis in H9c2 cardiomyoblasts.

    PubMed

    Sun, Xiao; Sun, Gui-Bo; Wang, Min; Xiao, Jing; Sun, Xiao-Bo

    2011-08-01

    Flavonoids with potent anti-oxidative effects are the major effective components in traditional herbal medicine used in treating cardiovascular diseases. Cynaroside is a flavonoid compound that exhibits anti-oxidative capabilities. However, little is known about its effect on oxidative injury to cardiac myocytes and the underlying mechanisms. This study was designed to investigate the protective effects of cynaroside against H(2) O(2) -induced apoptosis in H9c2 cardiomyoblasts. H9c2 cells were pretreated with cynaroside for 4 h before exposure to 150 µM H(2) O(2) for 6  h. H(2) O(2) treatment caused severe injury to the H9c2 cells, which was accompanied by apoptosis, as revealed by analysis of cell nuclear morphology, through Annexin V FITC/PI staining and caspase proteases activation. Cynaroside pretreatment significantly reduced the apoptotic rate by enhancing the endogenous anti-oxidative activity of superoxide dismutase, glutathione peroxidase, and catalase, thereby inhibiting intracellular reactive oxygen species (ROS) generation. Moreover, cynaroside moderated H(2) O(2) -induced disruption of mitochondrial membrane potential, increased the expression of anti-apoptotic protein Bcl-2 while decreased the expression of pro-apoptotic protein Bax, and thereby inhibited the release of apoptogenic factors (cytochrome c and smac/Diablo) from mitochondria in H9c2 cells. Our data also demonstrated that cynaroside pretreatment showed an inhibitory effect on the H(2) O(2) -induced increase in c-Jun N-terminal kinase (JNK) and P53 protein expression. These results suggest that cynaroside prevents H(2) O(2) -induced apoptosis in H9c2 cell by reducing the endogenous production of ROS, maintaining mitochondrial function, and modulating the JNK and P53 pathways. PMID:21445859

  6. AG4, a compound isolated from Radix Ardisiae Gigantifoliae, induces apoptosis in human nasopharyngeal cancer CNE cells through intrinsic and extrinsic apoptosis pathways.

    PubMed

    Dong, Xian-Zhe; Xie, Ting-Ting; Zhou, Xiao-Jiang; Mu, Li-Hua; Zheng, Xiao-Li; Guo, Dai-Hong; Liu, Ping; Ge, Xiao-Yue

    2015-03-01

    3β-O-{α-L-Pyran rhamnose-(1→3)-[β-D-xylopyranose-(1→2)]-β-D-glucopyranose-(1→4)-[β-D-lucopyranose-(1→2)]-α-L-pyran arabinose}-cyclamiretin A (AG4) is a saponin component obtained from the Giantleaf Ardisia Rhizome (Rhizoma Ardisiae Gigantifoliae). The present study aimed to investigate the antitumor potential of AG4 and its possible mechanisms in human nasopharyngeal carcinoma cells (CNE). We exposed tumor cells to AG4 to investigate which cell line was the most sensitive to AG4. Cell viability was assessed using the MTT reduction assay, and the effects of AG4 on apoptosis, reactive oxygen species (ROS) content, mitochondrial membrane potential (MMP), and cell cycle were detected using a flow cytometer; the glutathione, superoxide dismutase and malondialdehyde activities were measured using colorimetric methods. The relative expressions of Bax, Bad, Bid, Bcl-2, and Fas mRNA were calculated using the (Equation is included in full-text article.)comparative method by real-time PCR studies and protein was detected by western blotting. AG4 markedly inhibited the growth of CNE cells by decreasing cell proliferation, inducing apoptosis, and blocking the cell cycle in the S phase. The release of caspase-3, caspase-8, and caspase-9 was stimulated by AG4 in CNE, and the decreased proliferation induced by AG4 was blocked by the inhibitor of pan caspase (Z-VAD-FMK). Moreover, the MMP was decreased in AG4-treated cells, and AG4-induced cell apoptosis was accompanied by a rapid and lasting increase in ROS, which was abolished by N-acetyl-L-cysteine (NAC); glutathione, superoxide dismutase, and malondialdehyde were regulated by AG4. AG4 inhibited Bcl-2 mRNA and protein expression and stimulated Bax, Bad, Bid, Fas mRNA, and protein expression in CNE cultures, suggesting an effect at the transcriptional and protein level. In addition, both the FasL inhibitor (AF-016) and the Bcl-2 family inhibitor (GX15-070) could prevent the cell apoptosis induced by AG4. The

  7. Methyl Sartortuoate Inhibits Colon Cancer Cell Growth by Inducing Apoptosis and G2/M-Phase Arrest.

    PubMed

    Lan, Qiusheng; Li, Shoufeng; Lai, Wei; Xu, Heyang; Zhang, Yang; Zeng, Yujie; Lan, Wenjian; Chu, Zhonghua

    2015-08-17

    The potential anti-neoplastic activity of terpenoids is of continued interest. In this study, we investigate whether methyl sartortuoate, a terpenoid isolated from soft coral, induced cell cycle arrest and apoptosis in a human colon cancer cell line. Culture studies found that methyl sartortuoate inhibited colon cancer cell (LoVo and RKO) growth and caused apoptotic death in a concentration- and time-dependent manner, by activation of caspase-8, caspase-9, caspase-3, p53 and Bax, and inactivation of B-cell lymphoma 2 (Bcl-2) apoptosis regulating proteins. Methyl sartortuoate treatment led to reduced expression of cdc2 and up-regulated p21 and p53, suggesting that Methyl sartortuoate induced G2-M arrest through modulation of p53/p21/cdc2 pathways. Methyl sartortuoate also up-regulated phospho-JNK and phospho-p38 expression levels. This resulted in cell cycle arrest at the G2-M phase and apoptosis in LoVo and RKO cells. Treatment with the JNK inhibitor SP600125 and the p38 MAPK inhibitor SB203580 prevented methyl sartortuoate-induced apoptosis in LoVo cells. Moreover, methyl sartortuoate also prevented neoplasm growth in NOD-SCID nude mice inoculated with LoVo cells. Taken together, these findings suggest that methyl sartortuoate is capable of leading to activation of caspase-8, -9, -3, increasing p53 and Bax/Bcl-2 ratio apoptosis through MAPK-dependent apoptosis and results in G2-M phase arrest in LoVo and RKO cells. Thus, methyl sartortuoate may be a promising anticancer candidate.

  8. Matrine induces the apoptosis of lung cancer cells through downregulation of inhibitor of apoptosis proteins and the Akt signaling pathway.

    PubMed

    Niu, Huiyan; Zhang, Yifei; Wu, Baogang; Zhang, Yi; Jiang, Hongfang; He, Ping

    2014-09-01

    Lung cancer is the leading cause of cancer‑related mortality in humans. The prognosis for advanced lung cancer patients is extremely poor. Current standard care is rather ineffective for prolonging patient life while preserving satisfactory quality of life due to adverse side-effects. Matrine extracted from the traditional Chinese herbal plant Sophora flavescens was shown to induce cancer cell death in vitro. The aim of this study was to investigate the effect of matrine on the proliferation and apoptosis of lung cancer cells and the molecular basis of matrine-induced apoptosis. The results showed that matrine inhibited cell proliferation and induced apoptosis in lung cancer A549 and 95D cells in a dose- and time-dependent manner. The apoptotic effects of matrine on lung cancer cells appeared to act via the phosphatidylinositol 3-kinase/Akt/mammalian target of rapamycin (PI3K-Akt-mTOR) signaling pathway and downregulation of the expression of the inhibitor of apoptosis protein (IAP) family proteins. Matrine exerts its cancer-killing effect via promoting apoptosis in lung cancer cells and may be a useful adjuvant therapeutic scheme for treating advanced lung cancer patients.

  9. Embelin prevents LMP1-induced TRAIL resistance via inhibition of XIAP in nasopharyngeal carcinoma cells

    PubMed Central

    YANG, SHU; LI, SHI-SHENG; YANG, XIN-MING; YIN, DAN-HUI; WANG, LIN

    2016-01-01

    The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) selectively induces apoptosis in the majority of tumor cells, whilst sparing normal cells. However, the potential use of TRAIL in the treatment of cancer is limited by the inevitable emergence of drug resistance. The present study reports the upregulation of latent membrane protein 1 (LMP1)-induced TRAIL resistance via the enhanced expression of X-linked inhibitor of apoptosis protein (XIAP) in nasopharyngeal carcinoma (NPC) cells. LMP1-positive NPC cells were indicated to be more sensitive to TRAIL compared with LMP1-negative NPC cells in three NPC cell lines. CNE-1 is a LMP1-negative NPC cell line that was transfected with pGL6-LMP1; following which, sensitivity to TRAIL decreased. LMP1-induced TRAIL resistance was associated with the decreased cleavage of caspase-8,-3 and −9, BH3 interacting domain death agonist (Bid) and mitochondrial depolarization, without any effects on the expression of the death receptors, B-cell lymphoma (Bcl)-2 and Bcl-extra long. Knockdown of XIAP with small interfering RNA increased caspase-3 and −9 and Bid cleavage, and prevented LMP1-induced TRAIL resistance. Furthermore, embelin, the inhibitor of XIAP, prevented LMP1-induced TRAIL resistance in the Epstein-Barr virus (EBV)-positive CNE-1-LMP1 and C666-1 NPC cell lines. However, embelin did not enhance TRAIL-induced apoptosis in NP-69, which was used as a benign nasopharyngeal epithelial cell line. These data show that LMP1 inhibits TRAIL-mediated apoptosis by upregulation of XIAP. Embelin may be used in an efficacious and safe manner to prevent LMP1-induced TRAIL resistance. The present study may have implications for the development and validation of novel strategies to prevent TRAIL resistance in EBV-positive NPC. PMID:27313761

  10. Molecular and Cellular Analysis of Human Immunodeficiency Virus-Induced Apoptosis in Lymphoblastoid T-Cell-Line-Expressing Wild-Type and Mutated CD4 Receptors

    PubMed Central

    Moutouh, Laure; Estaquier, Jérôme; Richman, Douglas D.; Corbeil, Jacques

    1998-01-01

    We have previously shown that the presence of the CD4 cytoplasmic tail is critical for human immunodeficiency virus (HIV)-induced apoptosis (J. Corbeil, M. Tremblay, and D. D. Richman, J. Exp. Med. 183:39–48, 1996). We have pursued our investigation of the role of the CD4 transduction pathway in HIV-induced apoptosis. To do this, wild-type and mutant forms of the CD4 cytoplasmic tail were stably expressed in the lymphoblastoid T-cell line A2.01. Apoptosis was prevented when CD4 truncated at residue 402 was expressed; however, cells expressing mutated receptors that do not associate with p56lck (mutated at the dicysteine motif and truncated at residue 418) but which conserved proximal domains of the cytoplasmic tail underwent apoptosis like wild-type CD4. The differences between wild-type and mutated receptors in the induction of apoptosis were not related to levels of p56lck or NF-κB activation. Initial signaling through the CD4 receptor played a major role in the sensitization of HIV-infected T cells to undergo apoptosis. Incubation of HIV-infected cells with monoclonal antibody (MAb) 13B8-2, which binds to CD4 in a region critical for dimerization of the receptor, prevented apoptosis without inhibiting HIV replication. Moreover, the apoptotic process was not related to Fas-Fas ligand interaction; however, an antagonistic anti-Fas MAb (ZB-4) enhanced apoptosis in HIV-infected cells without inducing apoptosis in uninfected cells. These observations demonstrate that CD4 signaling mediates HIV-induced apoptosis by a mechanism independent of Fas-Fas ligand interaction, does not require p56lck signaling, and may involve a critical region for CD4 dimerization. PMID:9733846

  11. Endoplasmic reticulum stress sensitizes pancreatic beta cells to interleukin-1β-induced apoptosis via Bim/A1 imbalance.

    PubMed

    Miani, M; Barthson, J; Colli, M L; Brozzi, F; Cnop, M; Eizirik, D L

    2013-01-01

    We have recently shown that the crosstalk between mild endoplasmic reticulum (ER) stress and low concentrations of the pro-inflammatory cytokine interleukin (IL)-1β exacerbates beta cell inflammatory responses via the IRE1α/XBP1 pathway. We presently investigated whether mild ER stress also sensitizes beta cells to cytokine-induced apoptosis. Cyclopiazonic acid (CPA)-induced ER stress enhanced the IL-1β apoptosis in INS-1E and primary rat beta cells. This was not prevented by XBP1 knockdown (KD), indicating the dissociation between the pathways leading to inflammation and cell death. Analysis of the role of pro- and anti-apoptotic proteins in cytokine-induced apoptosis indicated a central role for the pro-apoptotic BH3 (Bcl-2 homology 3)-only protein Bim (Bcl-2-interacting mediator of cell death), which was counteracted by four anti-apoptotic Bcl-2 (B-cell lymphoma-2) proteins, namely Bcl-2, Bcl-XL, Mcl-1 and A1. CPA+IL-1β-induced beta cell apoptosis was accompanied by increased expression of Bim, particularly the most pro-apoptotic variant, small isoform of Bim (BimS), and decreased expression of A1. Bim silencing protected against CPA+IL-1β-induced apoptosis, whereas A1 KD aggravated cell death. Bim inhibition protected against cell death caused by A1 silencing under all conditions studied. In conclusion, mild ER stress predisposes beta cells to the pro-apoptotic effects of IL-1β by disrupting the balance between pro- and anti-apoptotic Bcl-2 proteins. These findings link ER stress to exacerbated apoptosis during islet inflammation and provide potential mechanistic targets for beta cell protection, namely downregulation of Bim and upregulation of A1. PMID:23828564

  12. Antiinflammatory Effects of CD95 Ligand (FasL)-induced Apoptosis

    PubMed Central

    Gao, Yakun; Herndon, John M.; Zhang, Hui; Griffith, Thomas S.; Ferguson, Thomas A.

    1998-01-01

    Apoptosis is critical to homeostasis of multicellular organisms. In immune privileged sites such as the eye, CD95 ligand (FasL)-induced apoptosis controls dangerous inflammatory reactions that can cause blindness. Recently, we demonstrated that apoptotic cell death of inflammatory cells was a prerequisite for the induction of immune deviation after antigen presentation in the eye. In this report, we examine the mechanism by which this takes place. Our results show that Fas- mediated apoptosis of lymphoid cells leads to rapid production of interleukin (IL)-10 in these cells. The apoptotic cells containing IL-10 are responsible for the activation of immune deviation through interaction with antigen-presenting cells (APC). In support of this, we found that apoptotic cells from IL-10+/+ animals fed to APC in vitro promote Th2 cell differentiation, whereas apoptotic IL-10−/− cells, as well as nonapoptotic cells, favor Th1 induction. Thus, apoptotic cell death and tolerance are linked through the production of an antiinflammatory cytokine to prevent dangerous and unwanted immune responses that might compromise organ integrity. PMID:9730890

  13. Proteinase-activated receptor-1 mediates allogeneic CD8(+) T cell-induced apoptosis of vascular endothelial cells.

    PubMed

    Quan, Li; Jian, Zhang; Ping, Zou; Weiming, Li

    2009-12-01

    Vascular endothelial-cells injury plays a pivotal role in the pathogenesis of graft-versus-host disease (GVHD) and transplant-associated endothelial injury syndrome. Vascular endothelial cells are an exposed target tissue for immune-mediated injury during GVHD. Early endothelial injury syndromes share common features with acute GVHD. Chronic GVHD leads to a rarefaction of microvessels caused by the infiltration of alloreactive cytotoxic T lymphocytes. In this context, allogeneic reactive cytotoxic T cell may contribute to apoptosis of vascular endothelial cells. The involvement of proteinase-activated receptor (PAR-1) in regulation of apoptosis has been recently recognized in many cell types. We hypothesized that apoptosis of vascular endothelial cells induced by allogeneic cytotoxic T cell are mediated via the PAR-1. Allogeneic CD8(+) T cell, PAR-1 agonist peptide (SFLLRN) induced apoptosis of human umbilical vein endothelial cells (HUVECs) and human dermal microvascular endothelial cells (HDMECs) as assessed by AnnexinV-FITC labeling. To ascertain the mechanism of endothelial apoptosis, we determined that allogeneic CD8(+) T cell, SFLLRN enhanced cleavage of caspase-3 and led to p38MAPK activation as assessed by Western blot. The effects of allogeneic CD8(+) T cell and SFLLRN on apoptosis of vascular endothelial cells were largely prevented by a cleavage-blocking anti-human PAR-1-antibody (ATAP2) and a specific inhibitor of p38MAPK. In concert, these observations provide strong evidence that allogeneic CD8(+) T cell induces apoptosis of human vascular endothelial cells through PAR-1-dependent modulation of intrinsic apoptotic pathway via alterations of p38MAPK and caspase-3. PMID:19082770

  14. Inhibition of phosphate-induced apoptosis in resting zone chondrocytes by thrombin peptide 508.

    PubMed

    Zhong, Ming; Carney, Darrell H; Ryaby, James T; Schwartz, Zvi; Boyan, Barbara D

    2009-01-01

    Growth plate chondrocytes are susceptible to apoptosis. Terminally differentiated chondrocytes are deleted via apoptosis, which primes the growth plate to vascular invasion and subsequent bone formation. Whether less differentiated resting zone chondrocytes are subject to the same mechanism that governs the apoptotic pathway of more differentiated growth zone chondrocytes is not known. In our current study, we demonstrated that inorganic phosphate, a key inducer of growth plate chondrocyte apoptosis, also causes apoptosis in resting zone chondrocytes, via a pathway similar to the one in growth zone chondrocytes. Our results demonstrated that the conditions that cause growth plate chondrocyte apoptosis lie in the external environment, instead of the differences in differentiation state.

  15. Apoptosis induced by weisiensin B isolated from Rabdosia weisiensis C.Y. Wu in K562.

    PubMed

    Liu, Guo-An; Chang, Jin-Chun; Feng, Xiao-Lu; Ding, Lan

    2015-04-01

    The ent-kaurane diterpenoid weisinensis B shows significant cytotoxicity to human chronic myeloid leukemia K562 cells. It inhibits cell growth at low concentration and kills cells at high concentration. The compound induced cell apoptosis and necrosis mainly associated with G2/M phase cell cycle arrest and the ROS generation is the early event in weisiensin B induced cell apoptosis. PMID:26012257

  16. Skin-stage schistosomula of Schistosoma mansoni produce an apoptosis-inducing factor that can cause apoptosis of T cells.

    PubMed

    Chen, Lin; Rao, Kakuturu V N; He, Yi-Xun; Ramaswamy, Kalyanasundaram

    2002-09-13

    Skin-stage schistosomula of Schistosoma mansoni were found to secrete molecules that are pro-apoptotic for skin T lymphocytes as measured by annexin V staining, caspase-3 activity, caspase-8 activities, and DNA fragmentation. Caspase-8 activities in lymphocytes peaked approximately 8 h and caspase-3 activity peaked approximately 16 h after exposure to the parasite secretions. Subset analysis showed that mainly CD4(+) and CD8(+) cells (but not B cells) were susceptible to the parasite-induced pro-apoptotic effect. In situ staining confirmed the presence of apoptotic T cells around challenge parasites in the skin of naive or immunized animals. Analysis of T cells to identify the potential molecular pathway of the parasite-induced apoptosis showed increases in the expression of Fas, FasL, and the Fas-associated death domain. Blocking of FasL with a fusion protein reversed the parasite-induced apoptosis, suggesting a role for the Fas/FasL-mediated pathway in the parasite-induced T cell apoptosis. Subsequent analyses of the secretions of skin-stage schistosomula identified the pro-apoptotic activity as being associated with a protein of approximately 23 kDa. This protein was termed S. mansoni-derived apoptosis-inducing factor.

  17. Ultrastructural lesions induced by neptunium-237: apoptosis or necrosis?

    PubMed

    Pusset, D; Fromm, M; Poncy, J L; Kantelip, B; Galle, P; Chambaudet, A; Baud, M; Boulahdour, H

    2002-07-01

    In this study, we are concerned with the 237 isotope of neptunium (237Np), which is a by-product of uranium in nuclear reactors. To study ultrastructural lesions induced by this element, a group of rats were injected with a solution of 237Np-nitrate once a day for 14 weeks. Lesions observed in liver and kidney are described using electron microscopy. Ultrastructural alterations of cellular membranes and intracellular organelles demonstrated the existence of neptunium toxicity. This toxicity was characterized by various lesions, such as cytoplasmic clarification, disappearance of mitochondrial cristae, swollen mitochondria, abnormal condensation of nuclear chromatin, and nuclear fragmentations. This study demonstrated the probable induction of apoptosis by neptunium both in liver and kidneys.

  18. Artemisinin reduces cell proliferation and induces apoptosis in neuroblastoma.

    PubMed

    Zhu, Shunqin; Liu, Wanhong; Ke, Xiaoxue; Li, Jifu; Hu, Renjian; Cui, Hongjuan; Song, Guanbin

    2014-09-01

    Artemisinin, a natural product from the Chinese medicinal plant, Artemisia annua L., is commonly used in the treatment of malaria, and has recently been reported to have potent anticancer activity in various types of human tumors. Yet, the effect of artemisinin on neuroblastoma is still unclear. In the present study, we aimed to investigate the effects of artemisinin on neuroblastoma cells. We observed that artemisinin significantly inhibited cell growth and proliferation, and caused cell cycle arrest in the G1 phase in neuroblastoma cell lines. Annexin V-FITC/PI staining assay revealed that artemisinin markedly induced apoptosis. Soft agar assays revealed that artemisinin suppressed the ability of clonogenic formation of neuroblastoma cells and a xenograft study in NOD/SCID mice showed that artemisinin inhibited tumor growth and development in vivo. Therefore, our results suggest that the Chinese medicine artemisinin could serve as a novel potential therapeutic agent in the treatment of neuroblastoma. PMID:25017372

  19. Artemisinin reduces cell proliferation and induces apoptosis in neuroblastoma.

    PubMed

    Zhu, Shunqin; Liu, Wanhong; Ke, Xiaoxue; Li, Jifu; Hu, Renjian; Cui, Hongjuan; Song, Guanbin

    2014-09-01

    Artemisinin, a natural product from the Chinese medicinal plant, Artemisia annua L., is commonly used in the treatment of malaria, and has recently been reported to have potent anticancer activity in various types of human tumors. Yet, the effect of artemisinin on neuroblastoma is still unclear. In the present study, we aimed to investigate the effects of artemisinin on neuroblastoma cells. We observed that artemisinin significantly inhibited cell growth and proliferation, and caused cell cycle arrest in the G1 phase in neuroblastoma cell lines. Annexin V-FITC/PI staining assay revealed that artemisinin markedly induced apoptosis. Soft agar assays revealed that artemisinin suppressed the ability of clonogenic formation of neuroblastoma cells and a xenograft study in NOD/SCID mice showed that artemisinin inhibited tumor growth and development in vivo. Therefore, our results suggest that the Chinese medicine artemisinin could serve as a novel potential therapeutic agent in the treatment of neuroblastoma.

  20. Osteoprotegerin (OPG) protects ovarian cancer cells from TRAIL-induced apoptosis but does not contribute to malignant ascites-mediated attenuation of TRAIL-induced apoptosis

    PubMed Central

    2012-01-01

    Background Resistance to apoptosis is a major problem in ovarian cancer and correlates with poor prognosis. Osteoprotegerin (OPG) is a secreted factor in malignant ascites and acts as a decoy receptor for receptor activator of NF-κB ligand (RANKL) and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). TRAIL promotes apoptosis in ovarian cancer cells. Ovarian cancer ascites attenuate TRAIL-induced apoptosis raising the possibility that OPG contained in ascites may abrogate the anti-tumor activity of TRAIL. Methods Determination of OPG levels in ascites was measured by ELISA. Effect of OPG on TRAIL-induced cell death was determined by XTT and colony forming assays in ovarian cancer cell lines and primary tumor cells. Apoptosis was assessed by ELISA. Results We found that recombinant OPG and malignant ascites attenuates TRAIL-induced cell death and apoptosis in a dose-dependent manner in ovarian cancer cell lines and primary ovarian tumor cells. OPG is present at high levels in the ascites of patients with ovarian cancer. We found a positive correlation between the levels of OPG in ascites and the ability of the ascites to attenuate TRAIL-induced cell death. The anti-apoptotic effect of ascites was not reversed by co-incubation with an OPG blocking antibody. Conclusions OPG and malignant ascites protect ovarian cancer cells from TRAIL-induced apoptosis. Although malignant ascites contain high levels of OPG, OPG is not a critical component that contributes to ascites-mediated attenuation of TRAIL-induced apoptosis. PMID:23153223

  1. Morin, a flavonoid from moraceae, induces apoptosis by induction of BAD protein in human leukemic cells.

    PubMed

    Park, Cheol; Lee, Won Sup; Go, Se-Il; Nagappan, Arulkumar; Han, Min Ho; Hong, Su Hyun; Kim, Gon Sup; Kim, Gi Young; Kwon, Taeg Kyu; Ryu, Chung Ho; Shin, Sung Chul; Choi, Yung Hyun

    2014-12-30

    Evidence suggests that phytochemicals can safely modulate cancer cell biology and induce apoptosis. Here, we investigated the anti-cancer activity of morin, a flavone originally isolated from members of the Moraceae family in human leukemic cells, focusing on apoptosis. An anti-cancer effect of morin was screened with several human leukemic cell lines. U937 cells were most sensitive to morin, where it induced caspase-dependent apoptosis in a dose-dependent manner. It also induced loss of MMP (ΔΨm) along with cytochrome c release, down-regulated Bcl-2 protein, and up-regulated BAX proteins. The apoptotic activity of morin was significantly attenuated by Bcl-2 augmentation. In conclusion, morin induced caspase-dependent apoptosis through an intrinsic pathway by upregulating BAD proteins. In addition, Bcl-2 protein expression is also important in morin-induced apoptosis of U937 cells. This study provides evidence that morin might have anticancer properties in human leukemic cells.

  2. PUMA mediates ER stress-induced apoptosis in portal hypertensive gastropathy.

    PubMed

    Tan, S; Wei, X; Song, M; Tao, J; Yang, Y; Khatoon, S; Liu, H; Jiang, J; Wu, B

    2014-03-13

    Mucosal apoptosis has been demonstrated to be an essential pathological feature in portal hypertensive gastropathy (PHG). p53-upregulated modulator of apoptosis (PUMA) was identified as a BH3-only Bcl-2 family protein that has an essential role in apoptosis induced by a variety of stimuli, including endoplasmic reticulum (ER) stress. However, whether PUMA is involved in mucosal apoptosis in PHG remains unclear, and whether PUMA induces PHG by mediating ER stress remains unknown. The aim of the study is to investigate whether PUMA is involved in PHG by mediating ER stress apoptotic signaling. To identify whether PUMA is involved in PHG by mediating ER stress, gastric mucosal injury and apoptosis were studied in both PHG patients and PHG animal models using PUMA knockout (PUMA-KO) and PUMA wild-type (PUMA-WT) mice. The induction of PUMA expression and ER stress signaling were investigated, and the mechanisms of PUMA-mediated apoptosis were analyzed. GES-1 and SGC7901 cell lines were used to further identify whether PUMA-mediated apoptosis was induced by ER stress in vitro. Epithelial apoptosis and PUMA were markedly induced in the gastric mucosa of PHG patients and mouse PHG models. ER stress had a potent role in the induction of PUMA and apoptosis in PHG models, and the apoptosis was obviously attenuated in PUMA-KO mice. Although the targeted deletion of PUMA did not affect ER stress, mitochondrial apoptotic signaling was downregulated in mice. Meanwhile, PUMA knockdown significantly ameliorated ER stress-induced mitochondria-dependent apoptosis in vitro. These results indicate that PUMA mediates ER stress-induced mucosal epithelial apoptosis through the mitochondrial apoptotic pathway in PHG, and that PUMA is a potentially therapeutic target for PHG.

  3. Modulation of iridovirus-induced apoptosis by endocytosis, early expression, JNK, and apical caspase

    SciTech Connect

    Chitnis, Nilesh S.; D'Costa, Susan M.; Paul, Eric R.; Bilimoria, Shaen L.

    2008-01-20

    Chilo iridescent virus (CIV) is the type species for the family Iridoviridae, which are large, isometric, cytoplasmic dsDNA viruses. We examined the mechanism of apoptosis induction by CIV. High CIV doses (CIV{sub XS}; 400 {mu}g/ml), UV-irradiated virus (CIV{sub UV}; 10 {mu}g/ml) and CVPE (CIV protein extract; 10 {mu}g/ml) induced apoptosis in 60% of treated Choristoneura fumiferana (IPRI-CF-124T) cells. Normal doses of infectious CIV (10 {mu}g/ml) induced apoptosis in only 10% of C. fumiferana (CF) cells. Apoptosis was inhibited by Z-IETD-FMK, an apical caspase inhibitor, indicating that CIV-induced apoptosis requires caspase activity. The putative caspase in CF cells was designated Cf-caspase-i. CIV{sub UV} or CVPE enhanced Cf-caspase-i activity by 80% at 24 h relative to mock-treated cells. Since the MAP kinase pathway induces or inhibits apoptosis depending on the context, we used JNK inhibitor SP600125 and demonstrated drastic suppression of CVPE-induced apoptosis. Thus, the JNK signaling pathway is significant for apoptosis in this system. Virus interaction with the cell surface was not sufficient for apoptosis since CIV{sub UV} particles bound to polysterene beads failed to induce apoptosis. Endocytosis inhibitors (bafilomycin or ammonium chloride) negated apoptosis induction by CIV{sub UV}, CIV{sub XS} or CVPE indicating that entry through this mode is required. Given the weak apoptotic response to infectious CIV, we postulated that viral gene expression inhibited apoptosis. CIV infection of cells pretreated with cycloheximide induced apoptosis in 69% of the cells compared to 10% in normal infections. Furthermore, blocking viral DNA replication with aphidicolin or phosphonoacetic acid suppressed apoptosis and Cf-caspase-i activity, indicating that early viral expression is necessary for inhibition of apoptosis, and de novo synthesis of viral proteins is not required for induction. We show for the first time that, in a member of the family Iridoviridae

  4. Regulation of isocyanate-induced apoptosis, oxidative stress, and inflammation in cultured human neutrophils: isocyanate-induced neutrophils apoptosis.

    PubMed

    Mishra, P K; Khan, S; Bhargava, A; Panwar, H; Banerjee, S; Jain, S K; Maudar, K K

    2010-06-01

    Implications of environmental toxins on the regulation of neutrophil function are being significantly appraised. Such effects can be varied and markedly different depending on the type and extent of chemical exposure, which results in direct damage to the immune system. Isocyanates with functional group (-NCO), are considered as highly reactive molecules with diverse industrial applications. However, patho-physiological implications resulting from their occupational and accidental exposures have not been well delineated. The present study was carried out to assess the immunotoxic response of isocyanates and their mode of action at a molecular level on cultured human neutrophils isolated from healthy human volunteers. Studies were conducted to evaluate both dose- and time-dependent (n = 3) response using N-succinimidyl N-methylcarbamate, a chemical entity that mimics the effects of methyl isocyanate in vitro. Measure of apoptosis through annexin-V-FITC/PI assay, active caspase-3, apoptotic DNA ladder assay and mitochondrial depolarization; induction of oxidative stress by CM-H(2)DCFDA and formation of 8'-hydroxy-2'-deoxyguanosine; and levels of antioxidant defense system enzyme glutathione reductase, multiplex cytometric bead array analysis to quantify the secreted cytokine levels (interleukin-8, interleukin-1beta, interleukin-6, interleukin-10, interferon-gamma, tumor necrosis factor, and interleukin-12p70) parameters were evaluated. Our results demonstrate that isocyanates induce neutrophil apoptosis via activation of mitochondrial-mediated pathway along with reactive oxygen species production; depletion in antioxidant defense states; and elevated pro-inflammatory cytokine response.

  5. Specific protein dephosphorylation in apoptosis induced by ionizing radiation and heat shock in human lymphoid tumor lines

    SciTech Connect

    Baxter, G.D.; Lavin, M.F. )

    1992-03-15

    Apoptosis or programmed cell death is observed in a variety of organisms and tissues and is characterized by distinct morphologic changes to the cell. Although early indicators of this process have been described, their functional relevance remains unknown. The authors have used two-dimensional gel electrophoresis to look for characteristic and consistent changes in the phosphorylation state of proteins during apoptosis, induced by different agents, in the B cell lymphoma line, BM13674, and the T cell leukemia line, CEM-C7. They report that apoptosis induced by either heat treatment or by ionizing radiation exposure is accompanied by dephosphorylation of a limited number of specific proteins. The pattern of dephosphorylation was similar after both treatments in BM13674 cells. In CEM-C7 cells, dephosphorylation was also observed after heat and irradiation. One of these proteins corresponded to one dephosphorylated in BM13674 cells. Okadaic acid, an inhibitor of phosphatases 1, 2A, and, to a lesser extent, 2B, prevented apoptosis in all cases and inhibited dephosphorylation of this common protein as well as some of the others. It seems likely that activation of a phosphatase(s) or loss of activity of a kinase is of central importance in apoptosis in these systems. 41 refs., 6 figs.

  6. Residual powders from Shochu distillation remnants induce apoptosis in human hepatoma cells via the caspase-independent pathway.

    PubMed

    Ohgidani, Masahiro; Komizu, Yuji; Goto, Koichi; Ueoka, Ryuichi

    2012-07-01

    Shochu distillation remnants (SDR) are by-products in the manufacturing process of the Japanese liquor Shochu and include various useful organic compounds derived from the fermentation of grains. We have obtained valuable powder (PSDR) from freeze-dried SDR by the treatment with ethanol. In this study, we examined the anticancer effects of barley-, rice-, and sweet potato-PSDR against HepG2 and HuH-7 cells of human hepatocellular carcinoma (HCC) in vitro. All PSDR inhibited the growth of both these HCC cells through the induction of apoptosis. Especially, barley-PSDR was the most effective for the growth inhibition and apoptosis induction of HCC cells of all PSDR. We next examined the apoptotic mechanisms induced by barley-PSDR. Decrease in mitochondrial membrane potential and release of cytochrome c from mitochondria were observed in HCC cells after the treatment with barley-PSDR. Furthermore, barley-PSDR induced the nuclear translocation of apoptosis-inducing factor (AIF) from mitochondria, while it did not significantly affect the activities of caspase-3, -8, and -9. The results suggested that barley-PSDR induced apoptosis against HCC cells via the caspase-independent mitochondrial pathway. The findings in this study suggest that PSDR has the possibility of therapeutic and/or preventive agents of HCC.

  7. Arbutin, an intracellular hydroxyl radical scavenger, protects radiation-induced apoptosis in human lymphoma U937 cells.

    PubMed

    Wu, Li-Hua; Li, Peng; Zhao, Qing-Li; Piao, Jin-Lan; Jiao, Yu-Fei; Kadowaki, Makoto; Kondo, Takashi

    2014-11-01

    Ionizing radiation (IR) can generate reactive oxygen species (ROS). Excessive ROS have the potential to damage cellular macromolecules including DNA, proteins, and lipids and eventually lead to cell death. In this study, we evaluated the potential of arbutin, a drug chosen from a series of traditional herbal medicine by measuring intracellular hydroxyl radical scavenging ability in X-irradiated U937 cells. Arbutin (hydroquinone-β-D-glucopyranoside), a naturally occurring glucoside of hydroquinone, has been traditionally used to treat pigmentary disorders. However, there are no reports describing the effect of arbutin on IR-induced apoptosis. We confirmed that arbutin can protect cells from apoptosis induced by X-irradiation. The combination of arbutin and X-irradiation could reduce intracellular hydroxyl radical production and prevent mitochondrial membrane potential loss. It also could down-regulate the expression of phospho-JNK, phospho-p38 in whole cell lysate and activate Bax in mitochondria. Arbutin also inhibits cytochrome C release from mitochondria to cytosol. To verify the role of JNK in X-irradiation-induced apoptosis, the cells were pretreated with a JNK inhibitor, and found that JNK inhibitor could reduce apoptosis induced by X-irradiation. Taken together, our data indicate that arbutin plays an anti-apoptotic role via decreasing intracellular hydroxyl radical production, inhibition of Bax-mitochondria pathway and activation of the JNK/p38 MAPK pathway.

  8. GDC-0152 induces apoptosis through down-regulation of IAPs in human leukemia cells and inhibition of PI3K/Akt signaling pathway.

    PubMed

    Hu, Rong; Li, Jia; Liu, Zhuogang; Miao, Miao; Yao, Kun

    2015-02-01

    The inhibitor of apoptosis proteins (IAPs) is closely related to leukemia apoptosis. The present study was undertaken to determine the molecular mechanisms by which GDC-0152, an IAP inhibitor, induces apoptosis in human leukemia cells (K562 and HL60 cells). GDC-0152 inhibited the proliferation of K562 and HL60 cells in a dose- and time-dependent manner, which was largely attributed to intrinsic apoptosis. GDC-0152 down-regulated the IAPs including X-linked inhibitor of apoptosis protein (XIAP), cellular inhibitor of apoptosis protein-1 (cIAP1), and cellular inhibitor of apoptosis protein-2 (cIAP2) expression and induced the activation of caspase-9 and caspase-3. GDC-0152-induced cell proliferation inhibition in K562 cells was prevented by pan-caspase inhibitor. GDC-0152 also inhibited PI3K and Akt expression in K562 and HL60 cells. Taken together, these findings suggest that GDC-0152 results in human leukemia apoptosis through caspase-dependent mechanisms involving down-regulation of IAPs and inhibition of PI3K/Akt signaling.

  9. By reducing hexokinase 2, resveratrol induces apoptosis in HCC cells addicted to aerobic glycolysis and inhibits tumor growth in mice

    PubMed Central

    Xia, Yujing; He, Lei; Chen, Kan; Li, Jingjing; Li, Sainan; Liu, Tong; Zheng, Yuanyuan; Wang, Jianrong; Lu, Wenxia; Zhou, Yuqing; Yin, Qin; Abudumijiti, Huerxidan; Chen, Rongxia; Zhang, Rong; Zhou, Li; Zhou, Zheng; Zhu, Rong; Yang, Jing; Wang, Chengfen; Zhang, Huawei; Zhou, Yingqun; Xu, Ling; Guo, Chuanyong

    2015-01-01

    Cancer cells exhibit an altered metabolic phenotype known as the aerobic glycolysis. The expression of HK2 changes the metabolic phenotype of cells to support cancerous growth. In the present study, we investigated the inhibitory effect of resveratrol on HK2 expression and hepatocellular carcinoma (HCC) cell glycolysis. Aerobic glycolysis was observed in four HCC cell lines compared to the normal hepatic cells. Resveratrol sensitized aerobic glycolytic HCC cells to apoptosis, and this effect was attenuated by glycolytic inhibitors. The induction of mitochondrial apoptosis was associated with the decrease of HK2 expression by resveratrol in HCC cells. In addition, resveratrol enhanced sorafenib induced cell growth inhibition in aerobic glycolytic HCC cells. Combination treatment with both reagents inhibited the growth and promoted apoptosis of HCC-bearing mice. The reduction of HK2 by resveratrol provides a new dimension to clinical HCC therapies aimed at preventing disease progression. PMID:25938543

  10. The role of intracellular zinc in chromium(VI)-induced oxidative stress, DNA damage and apoptosis.

    PubMed

    Rudolf, Emil; Cervinka, Miroslav

    2006-09-25

    Several studies have demonstrated that zinc is required for the optimal functioning of the skin. Changes in intracellular zinc concentrations have been associated with both improved protection of skin cells against various noxious factors as well as with increased susceptibility to external stress. Still, little is known about the role of intracellular zinc in hexavalent chromium (Cr(VI))-induced skin injury. To address this question, the effects of zinc deficiency or supplementation on Cr(VI)-induced cytotoxicity, oxidative stress, DNA injury and cell death were investigated in human diploid dermal fibroblasts during 48 h. Zinc levels in fibroblasts were manipulated by pretreatment of cells with 100 microM ZnSO4 and 4 or 25 microM zinc chelator TPEN. Cr(VI) (50, 10 and 1 microM) was found to produce time- and dose-dependent cytotoxicity resulting in oxidative stress, suppression of antioxidant systems and activation of p53-dependent apoptosis which is reported for the first time in this model in relation to environmental Cr(VI). Increased intracellular zinc partially attenuated Cr(VI)-induced cytotoxicity, oxidative stress and apoptosis by enhancing cellular antioxidant systems while inhibiting Cr(VI)-dependent apoptosis by preventing the activation of caspase-3. Decreased intracellular zinc enhanced cytotoxic effects of all the tested Cr(VI) concentrations, leading to rapid loss of cell membrane integrity and nuclear dispersion--hallmarks of necrosis. These new findings suggest that Cr(VI) as a model environmental toxin may damage in deeper regions residing skin fibroblasts whose susceptibility to such toxin depends among others on their intracellular Zn levels. Further investigation of the impact of Zn status on skin cells as well as any other cell populations exposed to Cr(VI) or other heavy metals is warranted.

  11. Apoptosis of Corneal Epithelial Cells Caused by Ultraviolet B-induced Loss of K(+) is Inhibited by Ba(2.).

    PubMed

    Glupker, Courtney D; Boersma, Peter M; Schotanus, Mark P; Haarsma, Loren D; Ubels, John L

    2016-07-01

    UVB exposure at ambient outdoor levels triggers rapid K(+) loss and apoptosis in human corneal limbal epithelial (HCLE) cells cultured in medium containing 5.5 mM K(+), but considerably less apoptosis occurs when the medium contains the high K(+) concentration that is present in tears (25 mM). Since Ba(2+) blocks several K(+) channels, we tested whether Ba(2+)-sensitive K(+) channels are responsible for some or all of the UVB-activated K(+) loss and subsequent activation of the caspase cascade and apoptosis. Corneal epithelial cells in culture were exposed to UVB at 80 or 150 mJ/cm(2). Patch-clamp recording was used to measure UVB-induced K(+) currents. Caspase-activity and TUNEL assays were performed on HCLE cells exposed to UVB followed by incubation in the presence or absence of Ba(2+). K(+) currents were activated in HCLE cells following UVB-exposure. These currents were reversibly blocked by 5 mM Ba(2+). When HCLE cells were incubated with 5 mM Ba(2+) after exposure to UVB, activation of caspases-9, -8, and -3 and DNA fragmentation were significantly decreased. The data confirm that UVB-induced K(+) current activation and loss of intracellular K(+) leads to activation of the caspase cascade and apoptosis. Extracellular Ba(2+) inhibits UVB-induced apoptosis by preventing loss of intracellular K(+) when K(+) channels are activated. Ba(2+) therefore has effects similar to elevated extracellular K(+) in protecting HCLE cells from UVB-induced apoptosis. This supports our overall hypothesis that elevated K(+) in tears contributes to protection of the corneal epithelium from adverse effects of ambient outdoor UVB.

  12. Amyloid beta-peptide induces cell monolayer albumin permeability, impairs glucose transport, and induces apoptosis in vascular endothelial cells.

    PubMed

    Blanc, E M; Toborek, M; Mark, R J; Hennig, B; Mattson, M P

    1997-05-01

    Amyloid beta-peptide (A beta) is deposited as insoluble fibrils in the brain parenchyma and cerebral blood vessels in Alzheimer's disease (AD). In addition to neuronal degeneration, cerebral vascular alterations indicative of damage to vascular endothelial cells and disruption of the blood-brain barrier occur in AD. Here we report that A beta25-35 can impair regulatory functions of endothelial cells (ECs) from porcine pulmonary artery and induce their death. Subtoxic exposures to A beta25-35 induced albumin transfer across EC monolayers and impaired glucose transport into ECs. Cell death induced by A beta25-35 was of an apoptotic form, characterized by DNA condensation and fragmentation, and prevented by inhibitors of macromolecular synthesis and endonucleases. The effects of A beta25-35 were specific because A beta1-40 also induced apoptosis in ECs with the apoptotic cells localized to the microenvironment of A beta1-40 aggregates and because astrocytes did not undergo similar changes after exposure to A beta25-35. Damage and death of ECs induced by A beta25-35 were attenuated by antioxidants, a calcium channel blocker, and a chelator of intracellular calcium, indicating the involvement of free radicals and dysregulation of calcium homeostasis. The data show that A beta induces increased permeability of EC monolayers to macromolecules, impairs glucose transport, and induces apoptosis. If similar mechanisms are operative in vivo, then A beta and other amyloidogenic peptides may be directly involved in vascular EC damage documented in AD and other disorders that involve vascular amyloid accumulation. PMID:9109512

  13. The cytotoxic macrolide FD-891 induces caspase-8-dependent mitochondrial release of cytochrome c and subsequent apoptosis in human leukemia Jurkat cells.

    PubMed

    Inaba, Susumu; Eguchi, Tadashi; Motegi, Atsushi; Mizoue, Kazutoshi; Usui, Takeo; Nagai, Kazuo; Kataoka, Takao

    2009-09-01

    The 16-membered macrolide FD-891 exerts cytotoxicity toward several cancer cell lines. In this study, we showed that FD-891 induces apoptosis in various human cancer cell lines. Human leukemia Jurkat cells were highly sensitive to FD-891, exhibiting caspase activation and mitochondrial release of cytochrome c into the cytosol at early time points after exposure to FD-891. By contrast, Jurkat cells deficient in caspase-8 were resistant to FD-891-induced apoptosis and manifested little induction of cytochrome c release as well as caspase-9 processing. Consistent with these results, the overexpression of the Bcl-2 family member Bcl-x(L) or the caspase-8 modulator c-FLIP(L) markedly prevented FD-891-induced apoptosis. These results clearly demonstrate that FD-891 triggers caspase-8-dependent mitochondrial release of cytochrome c and subsequent apoptosis in Jurkat cells.

  14. Apoptosis and telomeres shortening related to HIV-1 induced oxidative stress in an astrocytoma cell line

    PubMed Central

    Pollicita, Michela; Muscoli, Carolina; Sgura, Antonella; Biasin, Alberto; Granato, Teresa; Masuelli, Laura; Mollace, Vincenzo; Tanzarella, Caterina; Del Duca, Claudio; Rodinò, Paola; Perno, Carlo Federico; Aquaro, Stefano

    2009-01-01

    Background Oxidative stress plays a key role in the neuropathogenesis of Human Immunodeficiency Virus-1 (HIV-1) infection causing apoptosis of astroglia cells and neurons. Recent data have shown that oxidative stress is also responsible for the acceleration of human fibroblast telomere shortening in vitro. In the present study we analyzed the potential relations occurring between free radicals formation and telomere length during HIV-1 mediated astroglial death. Results To this end, U373 human astrocytoma cells have been directly exposed to X4-using HIV-1IIIB strain, for 1, 3 or 5 days and treated (where requested) with N-acetylcysteine (NAC), a cysteine donor involved in the synthesis of glutathione (GSH, a cellular antioxidant) and apoptosis has been evaluated by FACS analysis. Quantitative-FISH (Q-FISH) has been employed for studying the telomere length while intracellular reduced/oxidized glutathione (GSH/GSSG) ratio has been determined by High-Performance Liquid Chromatography (HPLC). Incubation of U373 with HIV-1IIIB led to significant induction of cellular apoptosis that was reduced in the presence of 1 mM NAC. Moreover, NAC improved the GSH/GSSG, a sensitive indicator of oxidative stress, that significantly decreased after HIV-1IIIB exposure in U373. Analysis of telomere length in HIV-1 exposed U373 showed a statistically significant telomere shortening, that was completely reverted in NAC-treated U373. Conclusion Our results support the role of HIV-1-mediated oxidative stress in astrocytic death and the importance of antioxidant compounds in preventing these cellular damages. Moreover, these data indicate that the telomere structure, target for oxidative damage, could be the key sensor of cell apoptosis induced by oxidative stress after HIV infection. PMID:19463156

  15. Accumulation of tissue factor in endothelial cells induces cell apoptosis, mediated through p38 and p53 activation.

    PubMed

    ElKeeb, A M; Collier, M E W; Maraveyas, A; Ettelaie, C

    2015-08-01

    We previously reported that high levels of tissue factor (TF) can induce cellular apoptosis in endothelial cells. In this study, TF-mediated mechanisms of induction of apoptosis were explored. Endothelial cells were transfected to express wild-type TF. Additionally, cells were transfected to express Asp253-substituted, or Ala253-substitued TF to enhance or prevent TF release, respectively. Alternatively, cells were pre-incubated with TF-rich and TF-poor microvesicles. Cell proliferation, apoptosis and the expression of cyclin D1, p53, bax and p21 were measured following activation of cells with PAR2-agonist peptide. Greatest levels of cell proliferation and cyclin D1 expression were observed in cells expressing wild-type or Asp253-substituted TF. In contrast, increased cellular apoptosis was observed in cells expressing Ala253-substituted TF, or cells pre-incubated with TF-rich microvesicles. The level of p53 protein, p53-phosphorylation at ser33, p53 nuclear localisation and transcriptional activity, but not p53 mRNA, were increased in cells expressing wild-type and Ala253-substituted TF, or in cells pre-incubated with TF-rich microvesicles. However, the expression of bax and p21 mRNA, and Bax protein were only increased in cells pre-incubated with TF-rich microvesicle and in cells expressing Ala253-substituted TF. Inhibition of the transcriptional activity of p53 using pifithrin-α suppressed the expression of Bax. Finally, siRNA-mediated suppression of p38α, or inhibition using SB202190 significantly reduced the p53 protein levels, p53 nuclear localisation and transcriptional activity, suppressed Bax expression and prevented cellular apoptosis. In conclusion, accumulation of TF within endothelial cells, or sequestered from the surrounding can induce cellular apoptosis through mechanisms mediated by p38, and involves the stabilisation of p53. PMID:25903973

  16. Tamoxifen prevents apoptosis and follicle loss from cyclophosphamide in cultured rat ovaries.

    PubMed

    Piasecka-Srader, Joanna; Blanco, Fernando F; Delman, Devora H; Dixon, Dan A; Geiser, James L; Ciereszko, Renata E; Petroff, Brian K

    2015-05-01

    Recent studies documented that the selective estrogen receptor modulator tamoxifen prevents follicle loss and promotes fertility following in vivo exposure of rodents to irradiation or ovotoxic cancer drugs, cyclophosphamide and doxorubicin. In an effort to characterize the ovarian-sparing mechanisms of tamoxifen in preantral follicle classes, cultured neonatal rat ovaries (Day 4, Sprague Dawley) were treated for 1-7 days with active metabolites of cyclophosphamide (i.e., 4-hydroxycyclophosphamide; CTX) (0, 1, and 10 μM) and tamoxifen (i.e., 4-hydroxytamoxifen; TAM) (0 and 10 μM) in vitro, and both apoptosis and follicle numbers were measured. CTX caused marked follicular apoptosis and follicular loss. TAM treatment decreased follicular loss and apoptosis from CTX in vitro. TAM alone had no effect on these parameters. IGF-1 and IGF-1 receptor were assessed in ovarian tissue showing no impact of TAM or CTX on these endpoints. Targeted mRNA analysis during follicular rescue by TAM revealed decreased expression of multiple genes related to inflammation, including mediators of lipoxygenase and prostaglandin production and signaling (Alox5, Pla2g1b, Ptgfr), cytokine binding (Il1r1, Il2rg ), apoptosis (Tnfrsf1a), second messenger signaling (Mapk1, Mapk14, Plcg1), as well as tissue remodeling and vasodilation (Bdkrb2, Klk15). The results suggest that TAM protects the ovary from CTX-mediated toxicity through direct ovarian actions that oppose follicular loss. PMID:25833159

  17. HMGB1 mediates hyperglycaemia-induced cardiomyocyte apoptosis via ERK/Ets-1 signalling pathway.

    PubMed

    Wang, Wen-Ke; Lu, Qing-Hua; Zhang, Jia-Ning; Wang, Ben; Liu, Xiang-Juan; An, Feng-Shuang; Qin, Wei-Dong; Chen, Xue-Ying; Dong, Wen-Qian; Zhang, Cheng; Zhang, Yun; Zhang, Ming-Xiang

    2014-11-01

    Apoptosis is a key event involved in diabetic cardiomyopathy. The expression of high mobility group box 1 protein (HMGB1) is up-regulated in diabetic mice. However, the molecular mechanism of high glucose (HG)-induced cardiomyocyte apoptosis remains obscure. We aimed to determine the role of HMGB1 in HG-induced apoptosis of cardiomyocytes. Treating neonatal primary cardiomyocytes with HG increased cell apoptosis, which was accompanied by elevated levels of HMGB1. Inhibition of HMGB1 by short-hairpin RNA significantly decreased HG-induced cell apoptosis by reducing caspase-3 activation and ratio of Bcl2-associated X protein to B-cell lymphoma/leukemia-2 (bax/bcl-2). Furthermore, HG activated E26 transformation-specific sequence-1 (Ets-1), and HMGB1 inhibition attenuated HG-induced activation of Ets-1 via extracellular signal-regulated kinase 1/2 (ERK1/2) signalling. In addition, inhibition of Ets-1 significantly decreased HG-induced cardiomyocyte apoptosis. Similar results were observed in streptozotocin-treated diabetic mice. Inhibition of HMGB1 by short-hairpin RNA markedly decreased myocardial cell apoptosis and activation of ERK and Ets-1 in diabetic mice. In conclusion, inhibition of HMGB1 may protect against hyperglycaemia-induced cardiomyocyte apoptosis by down-regulating ERK-dependent activation of Ets-1.

  18. Licochalcone A induces autophagy through PI3K/Akt/mTOR inactivation and autophagy suppression enhances Licochalcone A-induced apoptosis of human cervical cancer cells.

    PubMed

    Tsai, Jen-Pi; Lee, Chien-Hsing; Ying, Tsung-Ho; Lin, Chu-Liang; Lin, Chia-Liang; Hsueh, Jung-Tsung; Hsieh, Yi-Hsien

    2015-10-01

    The use of dietary bioactive compounds in chemoprevention can potentially reverse, suppress, or even prevent cancer progression. However, the effects of licochalcone A (LicA) on apoptosis and autophagy in cervical cancer cells have not yet been clearly elucidated. In this study, LicA treatment was found to significantly induce the apoptotic and autophagic capacities of cervical cancer cells in vitro and in vivo. MTT assay results showed dose- and time-dependent cytotoxicity in four cervical cancer cell lines treated with LicA. We found that LicA induced mitochondria-dependent apoptosis in SiHa cells, with decreasing Bcl-2 expression. LicA also induced autophagy effects were examined by identifying accumulation of Atg5, Atg7, Atg12 and microtubule-associated protein 1 light chain 3 (LC3)-II. Treatment with autophagy-specific inhibitors (3-methyladenine and bafilomycin A1) enhanced LicA-induced apoptosis. In addition, we suggested the inhibition of phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of mTOR pathway by LicA. Furthermore, the inhibition of PI3K/Akt by LY294002/si-Akt or of mTOR by rapamycin augmented LicA-induced apoptosis and autophagy. Finally, the in vivo mice bearing a SiHa xenograft, LicA dosed at 10 or 20 mg/kg significantly inhibited tumor growth. Our findings demonstrate the chemotherapeutic potential of LicA for treatment of human cervical cancer.

  19. Curcumin-induced recovery from hepatic injury involves induction of apoptosis of activated hepatic stellate cells.

    PubMed

    Priya, S; Sudhakaran, P R

    2008-10-01

    Hepatic stellate cells (HSCs) undergo activation and transdifferentiation to myofibroblast like cells in liver injury, leading to liver fibrosis. During recovery from injury, activated HSCs may either revert back to quiescent state or undergo apoptosis or both. In the present study, we have examined whether recovery from hepatic injury involves apoptosis of activated HSCs and tested whether curcumin (the yellow pigment from Curcuma longa Linn.) promotes recovery from hepatic injury by inducing apoptosis of these cells. Hepatic injury was induced by CCl4 and apoptosis was studied in HSCs isolated from liver by MTT assay, DNA fragmentation, and DAPI and annexin staining. Hepatic recovery was assessed by measuring hepatic marker activities, such as serum GOT, GPT and protein. Hepatic recovery occurred within 4 weeks after inducing injury in untreated control, whereas curcumin treatment caused hepatic recovery within 2 weeks, as evidenced by the reduction of hepatic marker activities to near normal levels. HSCs isolated from liver of animals treated with curcumin showed maximum apoptotic marker activities in 2nd week, whereas in HSCs from untreated control recovering from injury, maximum apoptosis was observed in 4th week. Induction of apoptosis in vivo during hepatic recovery was also suggested by increase in caspase-3 activity. Treatment of isolated HSCs in culture with curcumin caused apoptosis during later stages confirming that curcumin induced apoptosis of activated HSCs and not in unactivated quiescent HSCs. These results suggested that hepatoprotective effect of curcumin causing recovery from injury involved apoptosis of activated HSCs. PMID:19069843

  20. induces PUMA activation: a new mechanism for Aβ-mediated neuronal apoptosis.

    PubMed

    Feng, Jie; Meng, Chengbo; Xing, Da

    2015-02-01

    p53 upregulated modulator of apoptosis (PUMA) is a promising tumor therapy target because it elicits apoptosis and profound sensitivity to radiation and chemotherapy. However, inhibition of PUMA may be beneficial for curbing excessive apoptosis associated with neurodegenerative disorders. Alzheimer's disease (AD) is a representative neurodegenerative disease in which amyloid-β (Aβ) deposition causes neurotoxicity. The regulation of PUMA during Aβ-induced neuronal apoptosis remains poorly understood. Here, we reported that PUMA expression was significantly increased in the hippocampus of transgenic mice models of AD and hippocampal neurons in response to Aβ. PUMA knockdown protected the neurons against Aβ-induced apoptosis. Furthermore, besides p53, PUMA transactivation was also regulated by forkhead box O3a through p53-independent manner following Aβ treatment. Notably, PUMA contributed to neuronal apoptosis through competitive binding of apoptosis repressor with caspase recruitment domain to activate caspase-8 that cleaved Bid into tBid to accelerate Bax mitochondrial translocation, revealing a novel pathway of Bax activation by PUMA to mediate Aβ-induced neuronal apoptosis. Together, we demonstrated that PUMA activation involved in Aβ-induced apoptosis, representing a drug target to antagonize AD progression.

  1. The effect of tianeptine in the prevention of radiation-induced neurocognitive impairment.

    PubMed

    Akyurek, Serap; Senturk, Vesile; Oncu, Bedriye; Ozyigit, Gokhan; Yilmaz, Sercan; Gokce, Saban Cakir

    2008-12-01

    Radiation-induced neurocognitive impairment is an undesirable radiation-induced toxicity and a common health problem in patients with primary or metastatic brain tumor. It greatly impairs quality of life for long-term brain tumor survivors. Hippocampus is the most important brain structure for neurocognitive functions. It has been shown that radiation affects the hippocampal neurogenesis due to either induce the apoptosis or reduce the precursor cell proliferation in the hippocampus. Radiation-induced microglial inflammatory response is also negative regulator of neurogenesis. Tianeptine is a clinically effective antidepressant that induces neurogenesis. It has also been shown that tianeptine is able to reduce apoptosis and cytoprotective against the effects of proinflammatory cytokines in the hippocampus. Given the putative role of impaired hippocampal neurogenesis in radiation-induced neurocognitive impairment we think that tianeptine can be effective for preventing radiation-induced neurocognitive impairment by increasing hippocampal neurogenesis.

  2. Cystine dimethyl ester induces apoptosis through regulation of PKC-δ and PKC-ε in prostate cancer cells.

    PubMed

    Gurbuz, Nilgun; Park, Margaret A; Dent, Paul; Abdel Mageed, Asim B; Sikka, Suresh C; Baykal, Asli

    2015-01-01

    Protein kinase C-δ (PKC-δ) and PKC-ε are reported to be effective in cancer prevention via S-thiolation-mediated mechanisms. This may be through stimulation of the pro-apoptotic, tumor-suppressive isozyme PKC-δ and/or inactivation of the growth stimulatory, oncogenic isozyme PKC-ε. We investigated oxidative regulatory responses of PKC-δ and PKC-ε to cystine dimethyl ester (CDME), a metabolic precursor of cystine, which, by inducing release of cellular cystine stimulates apoptosis in different prostate cancer cells, PC3 and LNCaP, compared to normal RWPE1 cells. Treatment of CDME in doses of 0.5mM and 5mM significantly induces apoptosis due to regulation of concentration-dependent PKC-δ stimulation and PKC-ε reduction in these prostate cancer cells. This apoptotic regulation was confirmed by immunoblot analyses and specific PKC enzyme assays in immunoprecipitated samples. Additionally, inhibition of PKC-δ by small interfering RNA (siRNA) proved that CDME-induced cell death was dependent on PKC-δ activity in prostate cancer cells. These data demonstrated that CDME induces apoptosis by cysteinylation of both PKC-δ and PKC-ε in tumorigenic prostate epithelial cells compared to control nontumorigenic cells. Cellular cystine may play a critical role in treatment and/or prevention of prostate cancer by regulating PKC activity.

  3. Resveratrol protects against 2-bromopropane-induced apoptosis and disruption of embryonic development in blastocysts.

    PubMed

    Chan, Wen-Hsiung

    2011-01-01

    2-Bromopropane (2-BP) is used as an alternative to ozone-depleting cleaning solvents. Previously, we reported that 2-BP has cytotoxic effects on mouse blastocysts and is associated with defects in subsequent development. In the present work, we show that 2-BP induces apoptosis in the inner cell mass of mouse blastocysts, and inhibits cell proliferation. Both effects are suppressed by resveratrol, a grape-derived phytoalexin with known antioxidant and anti-inflammatory properties. 2-BP-treated blastocysts displayed lower levels of implantation (compared to controls) when plated on culture dishes in vitro, and a reduced ability to proceed to later stages of embryonic development. Pretreatment with resveratrol prevented 2-BP-induced disruption of embryonic development, both in vitro and in vivo. Further investigation of these processes revealed that 2-BP directly promotes ROS generation, loss of mitochondrial membrane potential (MMP), and activation of caspase-3, whereas resveratrol effectively blocks 2-BP-induced ROS production and the accompanying apoptotic biochemical changes. Our results collectively imply that 2-BP triggers the mitochondrion-dependent apoptotic pathway via ROS generation, and the antioxidant activity of resveratrol prevents 2-BP-induced toxicity. PMID:21954340

  4. Resveratrol Protects against 2-Bromopropane-Induced Apoptosis and Disruption of Embryonic Development in Blastocysts

    PubMed Central

    Chan, Wen-Hsiung

    2011-01-01

    2-Bromopropane (2-BP) is used as an alternative to ozone-depleting cleaning solvents. Previously, we reported that 2-BP has cytotoxic effects on mouse blastocysts and is associated with defects in subsequent development. In the present work, we show that 2-BP induces apoptosis in the inner cell mass of mouse blastocysts, and inhibits cell proliferation. Both effects are suppressed by resveratrol, a grape-derived phytoalexin with known antioxidant and anti-inflammatory properties. 2-BP-treated blastocysts displayed lower levels of implantation (compared to controls) when plated on culture dishes in vitro, and a reduced ability to proceed to later stages of embryonic development. Pretreatment with resveratrol prevented 2-BP-induced disruption of embryonic development, both in vitro and in vivo. Further investigation of these processes revealed that 2-BP directly promotes ROS generation, loss of mitochondrial membrane potential (MMP), and activation of caspase-3, whereas resveratrol effectively blocks 2-BP-induced ROS production and the accompanying apoptotic biochemical changes. Our results collectively imply that 2-BP triggers the mitochondrion-dependent apoptotic pathway via ROS generation, and the antioxidant activity of resveratrol prevents 2-BP-induced toxicity. PMID:21954340

  5. Tauroursodeoxycholic acid dampens oncogenic apoptosis induced by endoplasmic reticulum stress during hepatocarcinogen exposure

    PubMed Central

    Vandewynckel, Yves-Paul; Laukens, Debby; Devisscher, Lindsey; Paridaens, Annelies; Bogaerts, Eliene; Verhelst, Xavier; Van den Bussche, Anja; Raevens, Sarah; Van Steenkiste, Christophe; Van Troys, Marleen; Ampe, Christophe; Descamps, Benedicte; Vanhove, Chris; Govaere, Olivier; Geerts, Anja; Van Vlierberghe, Hans

    2015-01-01

    Hepatocellular carcinoma (HCC) is characterized by the accumulation of unfolded proteins in the endoplasmic reticulum (ER), which activates the unfolded protein response (UPR). However, the role of ER stress in tumor initiation and progression is controversial. To determine the impact of ER stress, we applied tauroursodeoxycholic acid (TUDCA), a bile acid with chaperone properties. The effects of TUDCA were assessed using a diethylnitrosamine-induced mouse HCC model in preventive and therapeutic settings. Cell metabolic activity, proliferation and invasion were investigated in vitro. Tumor progression was assessed in the HepG2 xenograft model. Administration of TUDCA in the preventive setting reduced carcinogen-induced elevation of alanine and aspartate aminotransferase levels, apoptosis of hepatocytes and tumor burden. TUDCA also reduced eukaryotic initiation factor 2α (eIf2α) phosphorylation, C/EBP homologous protein expression and caspase-12 processing. Thus, TUDCA suppresses carcinogen-induced pro-apoptotic UPR. TUDCA alleviated hepatic inflammation by increasing NF-κB inhibitor IκBα. Furthermore, TUDCA altered the invasive phenotype and enhanced metabolic activity but not proliferation in HCC cells. TUDCA administration after tumor development did not alter orthotopic tumor or xenograft growth. Taken together, TUDCA attenuates hepatocarcinogenesis by suppressing carcinogen-induced ER stress-mediated cell death and inflammation without stimulating tumor progression. Therefore, this chemical chaperone could represent a novel chemopreventive agent. PMID:26293671

  6. Molecular pathways: gene-environment interactions regulating dietary fiber induction of proliferation and apoptosis via butyrate for cancer prevention.

    PubMed

    Bultman, Scott J

    2014-02-15

    Gene-environment interactions are so numerous and biologically complicated that it can be challenging to understand their role in cancer. However, dietary fiber and colorectal cancer prevention may represent a tractable model system. Fiber is fermented by colonic bacteria into short-chain fatty acids such as butyrate. One molecular pathway that has emerged involves butyrate having differential effects depending on its concentration and the metabolic state of the cell. Low-moderate concentrations, which are present near the base of colonic crypts, are readily metabolized in the mitochondria to stimulate cell proliferation via energetics. Higher concentrations, which are present near the lumen, exceed the metabolic capacity of the colonocyte. Unmetabolized butyrate enters the nucleus and functions as a histone deacetylase (HDAC) inhibitor that epigenetically regulates gene expression to inhibit cell proliferation and induce apoptosis as the colonocytes exfoliate into the lumen. Butyrate may therefore play a role in normal homeostasis by promoting turnover of the colonic epithelium. Because cancerous colonocytes undergo the Warburg effect, their preferred energy source is glucose instead of butyrate. Consequently, even moderate concentrations of butyrate accumulate in cancerous colonocytes and function as HDAC inhibitors to inhibit cell proliferation and induce apoptosis. These findings implicate a bacterial metabolite with metaboloepigenetic properties in tumor suppression.

  7. Fibronectin prevents endotoxin shock after partial hepatectomy in rats via inhibition of nuclear factor-kappaB and apoptosis.

    PubMed

    Kwon, A-Hon; Qiu, Zeyu; Tsuji, Katsushige; Miyaso, Takeshi; Okumura, Tadayoshi

    2007-07-01

    Fibronectins (Fns) are involved in a number of biologic processes, such as cellular adhesion, motility, differentiation, apoptosis, hemostasis, wound healing, and ischemic injury. We investigated the possible mechanism underlying the protective action of plasma Fn (pFn) on endotoxin shock following partial hepatectomy in rats. Lipopolysaccharide (LPS) was administered intravenously to male Sprague-Dawley rats within 48 hrs of 70% hepatectomy. Prior to LPS administration, pFn or human serum albumin was given intravenously. The survival rate of the pFn-treated group was improved markedly compared with that of the controls. The levels of inflammatory cytokines and nitric oxide (NO) in serum were significantly lower in the pFn-treated group than in the control group. Expression of inducible nitric oxide synthase (iNOS) in hepatocytes also was reduced following pFn treatment. The degree of apoptosis and necrosis in the remnant liver was significantly lower in the pFn-treated rats than the controls. Furthermore, pFn pretreatment greatly inhibited the activation of nuclear factor-kappaB (NF-kappaB), caspase 3 and 8 activities, and cytochrome c release, and caused a decrease in mitochondrial Bcl-x(L). Plasma Fn prevents endotoxin-induced liver injury at least in part through inhibition of NF-kappaB activation, which causes the reduction of iNOS expression and NO production by hepatocytes, and through the downregulation of inflammatory cytokines and promotion of Bcl-x(L) expression. PMID:17609505

  8. Lipopolysaccharide Induces Human Pulmonary Micro-Vascular Endothelial Apoptosis via the YAP Signaling Pathway

    PubMed Central

    Yi, Lei; Huang, Xiaoqin; Guo, Feng; Zhou, Zengding; Chang, Mengling; Tang, Jiajun; Huan, Jingning

    2016-01-01

    Gram-negative bacterial lipopolysaccharide (LPS) induces a pathologic increase in lung vascular leakage under septic conditions. LPS-induced human pulmonary micro-vascular endothelial cell (HPMEC) apoptosis launches and aggravates micro-vascular hyper-permeability and acute lung injury (ALI). Previous studies show that the activation of intrinsic apoptotic pathway is vital for LPS-induced EC apoptosis. Yes-associated protein (YAP) has been reported to positively regulate intrinsic apoptotic pathway in tumor cells apoptosis. However, the potential role of YAP protein in LPS-induced HPMEC apoptosis has not been determined. In this study, we found that LPS-induced activation and nuclear accumulation of YAP accelerated HPMECs apoptosis. LPS-induced YAP translocation from cytoplasm to nucleus by the increased phosphorylation on Y357 resulted in the interaction between YAP and transcription factor P73. Furthermore, inhibition of YAP by small interfering RNA (siRNA) not only suppressed the LPS-induced HPMEC apoptosis but also regulated P73-mediated up-regulation of BAX and down-regulation of BCL-2. Taken together, our results demonstrated that activation of the YAP/P73/(BAX and BCL-2)/caspase-3 signaling pathway played a critical role in LPS-induced HPMEC apoptosis. Inhibition of the YAP might be a potential therapeutic strategy for lung injury under sepsis. PMID:27807512

  9. Silymarin protects epidermal keratinocytes from ultraviolet radiation-induced apoptosis and DNA damage by nucleotide excision repair mechanism.

    PubMed

    Katiyar, Santosh K; Mantena, Sudheer K; Meeran, Syed M

    2011-01-01

    Solar ultraviolet (UV) radiation is a well recognized epidemiologic risk factor for melanoma and non-melanoma skin cancers. This observation has been linked to the accumulation of UVB radiation-induced DNA lesions in cells, and that finally lead to the development of skin cancers. Earlier, we have shown that topical treatment of skin with silymarin, a plant flavanoid from milk thistle (Silybum marianum), inhibits photocarcinogenesis in mice; however it is less understood whether chemopreventive effect of silymarin is mediated through the repair of DNA lesions in skin cells and that protect the cells from apoptosis. Here, we show that treatment of normal human epidermal keratinocytes (NHEK) with silymarin blocks UVB-induced apoptosis of NHEK in vitro. Silymarin reduces the amount of UVB radiation-induced DNA damage as demonstrated by reduced amounts of cyclobutane pyrimidine dimers (CPDs) and as measured by comet assay, and that ultimately may lead to reduced apoptosis of NHEK. The reduction of UV radiation-induced DNA damage by silymarin appears to be related with induction of nucleotide excision repair (NER) genes, because UV radiation-induced apoptosis was not blocked by silymarin in NER-deficient human fibroblasts. Cytostaining and dot-blot analysis revealed that silymarin repaired UV-induced CPDs in NER-proficient fibroblasts from a healthy individual but did not repair UV-induced CPD-positive cells in NER-deficient fibroblasts from patients suffering from xeroderma pigmentosum complementation-A disease. Similarly, immunohistochemical analysis revealed that silymarin did not reduce the number of UVB-induced sunburn/apoptotic cells in the skin of NER-deficient mice, but reduced the number of sunburn cells in their wild-type counterparts. Together, these results suggest that silymarin exert the capacity to reduce UV radiation-induced DNA damage and, thus, prevent the harmful effects of UV radiation on the genomic stability of epidermal cells.

  10. The BET bromodomain inhibitor, JQ1, facilitates c-FLIP degradation and enhances TRAIL-induced apoptosis independent of BRD4 and c-Myc inhibition.

    PubMed

    Yao, Weilong; Yue, Ping; Khuri, Fadlo R; Sun, Shi-Yong

    2015-10-27

    Inhibition of BET bromodomains (BRDs) has emerged as a promising cancer therapeutic strategy. Accordingly, inhibitors of BRDs such as JQ1 have been actively developed and some have reached clinical testing. However, the mechanisms by which this group of inhibitors exerts their anticancer activity, including induction of apoptosis, have not been fully elucidated. This report reveals a previously uncovered activity of JQ1 in inducing c-FLIP degradation and enhancing TRAIL-induced apoptosis. JQ1 potently decreased c-FLIP (both long and short forms) levels in multiple cancer cell lines without apparently increasing the expression of DR5 and DR4. Consequently, JQ1, when combined with TRAIL, synergistically induced apoptosis; this enhanced apoptosis-inducing activity could be abolished by enforced expression of ectopic FLIPL or FLIPS. Hence it appears that JQ1 decreases c-FLIP levels, resulting in enhancement of TRAIL-induced apoptosis. Inhibition of proteasome with MG132 prevented JQ1-induced c-FLIP reduction. Moreover, JQ1 decreased c-FLIP stability. Therefore, JQ1 apparently decreases c-FLIP levels through facilitating its proteasomal degradation. Genetic inhibition of either BRD4 or c-Myc by knocking down their expression failed to mimic JQ1 in decreasing c-FLIP and enhancing TRAIL-induced apoptosis, suggesting that JQ1 induces c-FLIP degradation and enhances TRAIL-induced apoptosis independent of BRD4 or c-Myc inhibition. In summary, our findings in this study highlights a novel biological function of JQ1 in modulating apoptosis and warrant further study of the potential treatment of cancer with the JQ1 and TRAIL combination. PMID:26415225

  11. Chemical chaperone TUDCA prevents apoptosis and improves survival during polymicrobial sepsis in mice

    PubMed Central

    Doerflinger, Marcel; Glab, Jason; Nedeva, Christina; Jose, Irvin; Lin, Ann; O’Reilly, Lorraine; Allison, Cody; Pellegrini, Marc; Hotchkiss, Richard S.; Puthalakath, Hamsa

    2016-01-01

    Sepsis-induced lymphopenia is a major cause of morbidities in intensive care units and in populations with chronic conditions such as renal failure, diabetes, HIV and alcohol abuse. Currently, other than supportive care and antibiotics, there are no treatments for this condition. We developed an in vitro assay to understand the role of the ER-stress-mediated apoptosis process in lymphocyte death during polymicrobial sepsis, which was reproducible in in vivo mouse models. Modulating ER stress using chemical chaperones significantly reduced the induction of the pro-apoptotic protein Bim both in vitro and in mice. Furthermore, in a ‘two-hit’ pneumonia model in mice, we have been able to demonstrate that administration of the chemical chaperone TUDCA helped to maintain lymphocyte homeostasis by significantly reducing lymphocyte apoptosis and this correlated with four-fold improvement in survival. Our results demonstrate a novel therapeutic opportunity for treating sepsis-induced lymphopenia in humans. PMID:27694827

  12. Calpain and Reactive Oxygen Species Targets Bax for Mitochondrial Permeabilisation and Caspase Activation in Zerumbone Induced Apoptosis

    PubMed Central

    Sobhan, Praveen K.; Seervi, Mahendra; Deb, Lokesh; Varghese, Saneesh; Soman, Anjana; Joseph, Jeena; Mathew, Krupa Ann; Raghu, Godi; Thomas, George; E, Sreekumar; S, Manjula; R, Santosh Kumar T.

    2013-01-01

    Fluorescent protein based signaling probes are emerging as valuable tools to study cell signaling because of their ability to provide spatio- temporal information in non invasive live cell mode. Previously, multiple fluorescent protein probes were employed to characterize key events of apoptosis in diverse experimental systems. We have employed a live cell image based approach to visualize the key events of apoptosis signaling induced by zerumbone, the active principle from ginger Zingiber zerumbet, in cancer cells that enabled us to analyze prominent apoptotic changes in a hierarchical manner with temporal resolution. Our studies substantiate that mitochondrial permeabilisation and cytochrome c dependent caspase activation dominate in zerumbone induced cell death. Bax activation, the essential and early event of cell death, is independently activated by reactive oxygen species as well as calpains. Zerumbone failed to induce apoptosis or mitochondrial permeabilisation in Bax knockout cells and over-expression of Bax enhanced cell death induced by zerumbone confirming the essential role of Bax for mitochondrial permeabilsation. Simultaneous inhibition of reactive oxygen species and calpain is required for preventing Bax activation and cell death. However, apoptosis induced by zerumbone was prevented in Bcl 2 and Bcl-XL over-expressing cells, whereas more protection was afforded by Bcl 2 specifically targeted to endoplasmic reticulum. Even though zerumbone treatment down-regulated survival proteins such as XIAP, Survivin and Akt, it failed to affect the pro-apoptotic proteins such as PUMA and BIM. Multiple normal diploid cell lines were employed to address cytotoxic activity of zerumbone and, in general, mammary epithelial cells, endothelial progenitor cells and smooth muscle cells were relatively resistant to zerumbone induced cell death with lesser ROS accumulation than cancer cells. PMID:23593137

  13. Lipopolysaccharide Stimulates Butyric Acid-Induced Apoptosis in Human Peripheral Blood Mononuclear Cells

    PubMed Central

    Kurita-Ochiai, Tomoko; Fukushima, Kazuo; Ochiai, Kuniyasu

    1999-01-01

    We previously reported that butyric acid, an extracellular metabolite from periodontopathic bacteria, induced apoptosis in murine thymocytes, splenic T cells, and human Jurkat T cells. In this study, we examined the ability of butyric acid to induce apoptosis in peripheral blood mononuclear cells (PBMC) and the effect of bacterial lipopolysaccharide (LPS) on this apoptosis. Butyric acid significantly inhibited the anti-CD3 monoclonal antibody- and concanavalin A-induced proliferative responses in a dose-dependent fashion. This inhibition of PBMC growth by butyric acid depended on apoptosis in vitro. It was characterized by internucleosomal DNA digestion and revealed by gel electrophoresis followed by a colorimetric DNA fragmentation assay to occur in a concentration-dependent fashion. Butyric acid-induced PBMC apoptosis was accompanied by caspase-3 protease activity but not by caspase-1 protease activity. LPS potentiated butyric acid-induced PBMC apoptosis in a dose-dependent manner. Flow-cytometric analysis revealed that LPS increased the proportion of sub-G1 cells and the number of late-stage apoptotic cells induced by butyric acid. Annexin V binding experiments with fractionated subpopulations of PBMC in flow cytometory revealed that LPS accelerated the butyric acid-induced CD3+-T-cell apoptosis followed by similar levels of both CD4+- and CD8+-T-cell apoptosis. The addition of LPS to PBMC cultures did not cause DNA fragmentation, suggesting that LPS was unable to induce PBMC apoptosis directly. These data suggest that LPS, in combination with butyric acid, potentiates CD3+ PBMC T-cell apoptosis and plays a role in the apoptotic depletion of CD4+ and CD8+ cells. PMID:9864191

  14. Advanced oxidation protein products induce apoptosis in podocytes through induction of endoplasmic reticulum stress.

    PubMed

    Rong, Guang; Tang, Xun; Guo, Tingting; Duan, Na; Wang, Yue; Yang, Lei; Zhang, Jun; Liang, Xiujie

    2015-09-01

    Although podocyte apoptosis has been shown to be induced by the accumulation of advanced oxidation protein products (AOPPs), the mechanisms through which AOPPs trigger apoptosis in these cells remain unclear. In this study, we investigated the role of endoplasmic reticulum (ER) stress in AOPP-induced podocyte apoptosis. AOPP treatment induced overexpression of glucose-regulated protein 78 and CCAAT/enhancer-binding protein-homologous protein (CHOP) in podocytes, indicating that AOPPs induced ER stress. Notably, AOPP-induced increase in the rate of podocyte apoptosis was partly reversed by salubrinal, an ER stress inhibitor, whereas the AOPP effect was reproduced by an inducer of ER stress, thapsigargin, suggesting that AOPPs triggered podocyte apoptosis by inducing ER stress. Furthermore, AOPP-induced reactive oxygen species (ROS) generation, ER stress, and podocyte apoptosis were significantly inhibited by an nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitor, a ROS scavenger, or receptor of advanced glycation end products (RAGE) small interfering RNA (siRNA). Moreover, silencing of the three ER stress sensors, protein kinase-like ER kinase (PERK), activating transcription factor 6 (ATF6), and inositol requiring 1 (IRE1), respectively, significantly lowered the apoptotic rate of the cells compared with that of the scramble siRNA-transfected cells. Lastly, our data suggested that CHOP- and caspase-12-dependent pathways were involved in ER stress-mediated podocyte apoptosis and that Bcl-2 suppression was involved in CHOP-mediated apoptosis. Collectively, our results indicate for the first time that AOPPs trigger podocyte apoptosis through induction of ER stress, which might be regulated by NADPH oxidase-dependent ROS through RAGE, and that this apoptosis is mediated by three unfolded protein response pathways, the PERK, ATF6, and IRE1 pathways, and the mediators, CHOP and caspase-12. PMID:26197866

  15. The coffee diterpene kahweol sensitizes TRAIL-induced apoptosis in renal carcinoma Caki cells through down-regulation of Bcl-2 and c-FLIP.

    PubMed

    Um, Hee Jung; Oh, Jung Hwa; Kim, Yoon-Nyun; Choi, Yung Hyun; Kim, Sang Hyun; Park, Jong-Wook; Kwon, Taeg Kyu

    2010-06-01

    Kahweol, a coffee-specific diterpene, found in the beans of Coffea arabica, has potent anti-carcinogenic, anti-tumor, and anti-inflammatory properties. TRAIL is a potential anti-cancer compound that induces apoptosis in a wide variety of cancer cells, but not in most normal human cell types. In the present study, we show that kahweol sensitizes human renal cancer cells, but not normal human mesangial cells, to TRAIL-mediated apoptosis. Moreover, treatment with a combination of kahweol and TRAIL induces significant apoptosis in various cancer cell types, thus presenting an attractive novel strategy for cancer treatment. Our experiments show that treatment with a combination of kahweol and TRAIL-induced apoptosis, and stimulated of DEVDase activity, DNA fragmentation, and cleavage of PARP, which was prevented by pretreatment with z-VAD, indicative of cell death via a caspase-dependent pathway. Kahweol-induced down-regulation of Bcl-2 and ectopic expression of Bcl-2 led to attenuation of kahweol plus TRAIL-mediated apoptosis, indicative of Bcl-2 involvement in the apoptotic process. In addition, the c-FLIP and caspase signal pathways seem to play a crucial role in apoptosis triggered by the combination of kahweol and TRAIL in Caki cells. Our results collectively demonstrate that down-regulation of Bcl-2 and c-FLIP contributes to the sensitizing effect of kahweol on TRAIL-mediated apoptosis in cancer cells. PMID:20403343

  16. Butylbenzyl phthalate induces spermatogenic cell apoptosis in prepubertal rats.

    PubMed

    Alam, Mohammad Shah; Kurohmaru, Masamichi

    2016-02-01

    Butylbenzyl phthalate (BBP), a suspected endocrine disruptor, adversely affects male reproductive function. In this study, morphological alterations of prepubertal rat testes caused by single administration of BBP, were examined by light microscopy. Three-week-old male rats were given a single dose of 500 mg/kg BBP by oral gavage and sacrificed at 3, 12, and 24 h after administration. Histopathological examination revealed progressive detachment and sloughing of spermatogenic cells into the lumen, and a significant increase in the number of TUNEL-positive (apoptotic) spermatogenic cells in the treated groups, compared to the control. Semithin sections confirmed the apoptotic cells by their prominent basophilia, condensed chromatin, and shrunken cytoplasm, hallmarks of apoptotic cell death. Immunohistochemistry identified disruption of Sertoli cell vimentin and actin filaments in the treated groups. To elucidate the recovery effects of BBP, rats were treated in the same way and were sacrificed at D1-12h after administration. The apoptotic index returned to normal at D9. While, the testes revealed lower weight gain until D12. These results show for the first time that BBP induces collapse of vimentin filaments in Sertoli cells which may lead to disruption of Sertoli-spermatogenic cell physical interaction and induces spermatogenic cell apoptosis. PMID:26747412

  17. Osteoinductivity of engineered cartilaginous templates devitalized by inducible apoptosis.

    PubMed

    Bourgine, Paul E; Scotti, Celeste; Pigeot, Sebastien; Tchang, Laurent A; Todorov, Atanas; Martin, Ivan

    2014-12-01

    The role of cell-free extracellular matrix (ECM) in triggering tissue and organ regeneration has gained increased recognition, yet current approaches are predominantly based on the use of ECM from fully developed native tissues at nonhomologous sites. We describe a strategy to generate customized ECM, designed to activate endogenous regenerative programs by recapitulating tissue-specific developmental processes. The paradigm was exemplified in the context of the skeletal system by testing the osteoinductive capacity of engineered and devitalized hypertrophic cartilage, which is the primordial template for the development of most bones. ECM was engineered by inducing chondrogenesis of human mesenchymal stromal cells and devitalized by the implementation of a death-inducible genetic device, leading to cell apoptosis on activation and matrix protein preservation. The resulting hypertrophic cartilage ECM, tested in a stringent ectopic implantation model, efficiently remodeled to form de novo bone tissue of host origin, including mature vasculature and a hematopoietic compartment. Importantly, cartilage ECM could not generate frank bone tissue if devitalized by standard "freeze & thaw" (F&T) cycles, associated with a significant loss of glycosaminoglycans, mineral content, and ECM-bound cytokines critically involved in inflammatory, vascularization, and remodeling processes. These results support the utility of engineered ECM-based devices as off-the-shelf regenerative niches capable of recruiting and instructing resident cells toward the formation of a specific tissue.

  18. Omega-3 free fatty acids inhibit tamoxifen-induced cell apoptosis.

    PubMed

    Wu, Shufan; Guo, Yang; Wu, Yikuan; Zhu, Shenglong; He, Zhao; Chen, Yong Q

    2015-04-01

    Fish oil, which contains omega-3 fatty acids mainly in the form of triglycerides, has benefits for reducing breast cancer risk, similar to tamoxifen action. However, it remains to be elucidated whether the combination of omega-3 free fatty acid (ω-3FFA) with tamoxifen leads to improved treatment in breast cancer. In this study, we observed that ω-3FFA induces MCF-7 cell apoptosis to suppress cell growth. The treatment of breast cancer cells with ω-3FFA attenuated tamoxifen-induced cell apoptosis. ω-3FFA and tamoxifen significantly increased Erk1/2 and Akt phosphorylation levels in a dose and time dependent manner. Compared to ω-3FFA alone, the combination of tamoxifen with ω-3FFA significantly increased Erk1/2 and Akt phosphorylation levels. Because Erk1/2 and Akt activation has been linked to tamoxifen-related anti-estrogen resistance in breast cancer patients, these results indicate that ω-3FFA may interfere with the effects of tamoxifen in the prevention of breast cancer risk.

  19. Eliminating Legionella by inhibiting BCL-XL to induce macrophage apoptosis.

    PubMed

    Speir, Mary; Lawlor, Kate E; Glaser, Stefan P; Abraham, Gilu; Chow, Seong; Vogrin, Adam; Schulze, Keith E; Schuelein, Ralf; O'Reilly, Lorraine A; Mason, Kylie; Hartland, Elizabeth L; Lithgow, Trevor; Strasser, Andreas; Lessene, Guillaume; Huang, David C S; Vince, James E; Naderer, Thomas

    2016-01-01

    Human pathogenic Legionella replicate in alveolar macrophages and cause a potentially lethal form of pneumonia known as Legionnaires' disease(1). Here, we have identified a host-directed therapeutic approach to eliminate intracellular Legionella infections. We demonstrate that the genetic deletion, or pharmacological inhibition, of the host cell pro-survival protein BCL-XL induces intrinsic apoptosis of macrophages infected with virulent Legionella strains, thereby abrogating Legionella replication. BCL-XL is essential for the survival of Legionella-infected macrophages due to bacterial inhibition of host-cell protein synthesis, resulting in reduced levels of the short-lived, related BCL-2 pro-survival family member, MCL-1. Consequently, a single dose of a BCL-XL-targeted BH3-mimetic therapy, or myeloid cell-restricted deletion of BCL-XL, limits Legionella replication and prevents lethal lung infections in mice. These results indicate that repurposing BH3-mimetic compounds, originally developed to induce cancer cell apoptosis, may have efficacy in treating Legionnaires' and other diseases caused by intracellular microbes. PMID:27572165

  20. Sedum mexicanum Britt. Induces Apoptosis of Primary Rat Activated Hepatic Stellate Cells

    PubMed Central

    Lee, Shou-Lun; Chin, Ting-Yu; Lai, Ching-Long; Wang, Wen-Han

    2015-01-01

    Background. Liver fibrosis is a significant liver disease in Asian countries. Sedum mexicanum Britt. (SM) has been claimed to have antihepatitis efficacy. In traditional folk medicine, a solution of boiling water-extracted SM (SME) is consumed to prevent and treat hepatitis. However, its efficacy has not yet been verified. The purpose of this study was to investigate the in vitro effect of SME on hepatoprotection. Methods. Hepatic stellate cells (HSCs) and hepatocytes (HCs) were isolated from the livers of the rats by enzymatic digestion and density gradient centrifugation. Results. Treating the HCs and aHSCs with SME caused a dose-dependent decrease in the viability of aHSCs but not that of HCs. In addition, treatment with SME resulted in apoptosis of aHSCs, as determined by DAPI analysis and flow cytometry. SME also increased the amount of cleaved caspase-3, cleaved caspase-9, and cleaved poly ADP-ribose polymerase (PARP) in aHSCs. Furthermore, SME treatment induced a dose-dependent reduction in Bcl-2 expression and increased the expression of Bax in aHSCs. Conclusions. SME did not cause cytotoxicity in HCs, but it induced apoptosis in aHSCs through the mitochondria-dependent caspase-3 pathway. Therefore, SME may possess therapeutic potential for liver fibrosis. PMID:26078767

  1. Stimulatory effect of oral administration of tea, coffee or caffeine on UVB-induced apoptosis in the epidermis of SKH-1 mice

    SciTech Connect

    Conney, Allan H. Zhou, Sherry; Lee Maojung; Xie Jianguo; Yang, Chung S.; Lou Yourong; Lu Yaoping

    2007-11-01

    Oral administration of green tea or a caffeine solution, but not decaffeinated green tea, inhibits UVB-induced complete carcinogenesis in SKH-1 mice. Oral administration of green tea, coffee or a caffeine solution for 2 weeks enhanced UVB-induced increases in apoptosis in the epidermis, but these treatments had no effect in non-UVB treated normal epidermis. Our results suggest that administration of green tea, coffee and caffeine may inhibit UVB-induced carcinogenesis - at least in part - by enhancing UVB-induced apoptosis. Plasma levels of caffeine observed after its oral administration at cancer-preventive dose levels were within the range observed in moderate coffee drinkers. Topical applications of caffeine to mice previously treated with UVB for 20 weeks (high risk mice without tumors) inhibited the formation of tumors and stimulated apoptosis in the tumors but not in areas of the epidermis away from tumors. The selective effects of caffeine administration to stimulate UVB-induced apoptosis or apoptosis in tumors but not in normal epidermis or in areas of the epidermis away from tumors is of considerable interest, but the reasons for the selective effects of caffeine on apoptosis in DNA damaged tissues are unknown. Further studies are needed to determine mechanisms of these effects of caffeine and to determine the effects of caffeine administration on sunlight-induced actinic keratoses and squamous cell carcinomas in humans.

  2. Stimulatory effect of oral administration of tea, coffee or caffeine on UVB-induced apoptosis in the epidermis of SKH-1 mice.

    PubMed

    Conney, Allan H; Zhou, Sherry; Lee, Mao-Jung; Xie, Jian Guo; Yang, Chung S; Lou, You Rong; Lu, YaoPing

    2007-11-01

    Oral administration of green tea or a caffeine solution, but not decaffeinated green tea, inhibits UVB-induced complete carcinogenesis in SKH-1 mice. Oral administration of green tea, coffee or a caffeine solution for 2 weeks enhanced UVB-induced increases in apoptosis in the epidermis, but these treatments had no effect in non-UVB treated normal epidermis. Our results suggest that administration of green tea, coffee and caffeine may inhibit UVB-induced carcinogenesis--at least in part--by enhancing UVB-induced apoptosis. Plasma levels of caffeine observed after its oral administration at cancer-preventive dose levels were within the range observed in moderate coffee drinkers. Topical applications of caffeine to mice previously treated with UVB for 20 weeks (high risk mice without tumors) inhibited the formation of tumors and stimulated apoptosis in the tumors but not in areas of the epidermis away from tumors. The selective effects of caffeine administration to stimulate UVB-induced apoptosis or apoptosis in tumors but not in normal epidermis or in areas of the epidermis away from tumors is of considerable interest, but the reasons for the selective effects of caffeine on apoptosis in DNA damaged tissues are unknown. Further studies are needed to determine mechanisms of these effects of caffeine and to determine the effects of caffeine administration on sunlight-induced actinic keratoses and squamous cell carcinomas in humans.

  3. Par-4/NF-κB Mediates the Apoptosis of Islet β Cells Induced by Glucolipotoxicity.

    PubMed

    QiNan, Wu; XiaGuang, Gan; XiaoTian, Lei; WuQuan, Deng; Ling, Zhang; Bing, Chen

    2016-01-01

    Apoptosis of islet β cells is a primary pathogenic feature of type 2 diabetes, and ER stress and mitochondrial dysfunction play important roles in this process. Previous research has shown that prostate apoptosis response-4 (Par-4)/NF-κB induces cancer cell apoptosis through endoplasmic reticulum (ER) stress and mitochondrial dysfunction. However, the mechanism by which Par-4/NF-κB induces islet β cell apoptosis remains unknown. We used a high glucose/palmitate intervention to mimic type 2 diabetes in vitro. We demonstrated that the high glucose/palmitate intervention induced the expression and secretion of Par-4. It also causes increased expression and activation of NF-κB, which induced NIT-1 cell apoptosis and dysfunction. Overexpression of Par-4 potentiates these effects, whereas downregulation of Par-4 attenuates them. Inhibition of NF-κB inhibited the Par-4-induced apoptosis. Furthermore, these effects occurred through the ER stress cell membrane and mitochondrial pathway of apoptosis. Our findings reveal a novel role for Par-4/NF-κB in islet β cell apoptosis and type 2 diabetes. PMID:27340675

  4. Troxerutin inhibits 2,2',4,4'-tetrabromodiphenyl ether (BDE-47)-induced hepatocyte apoptosis by restoring proteasome function.

    PubMed

    Zhang, Zi-Feng; Shan, Qun; Zhuang, Juan; Zhang, Yan-Qiu; Wang, Xin; Fan, Shao-Hua; Lu, Jun; Wu, Dong-Mei; Hu, Bin; Zheng, Yuan-Lin

    2015-03-18

    Proteasome dysfunction has been associated with the pathogeneses of a variety of diseases and with the neurotoxicities of environmental chemicals; however, whether proteasome dysfunction plays a role in the cellular toxicity of polybrominated diphenyl ethers (PBDEs) has not been investigated to date. Emerging evidence suggests that antioxidants exhibit evident beneficial effects on the cellular toxicity associated with PBDEs. In the present study, we investigated whether troxerutin attenuates BDE-47-induced hepatocyte apoptosis by restoring proteasome function and explored the mechanisms underlying this effect. Our results revealed that proteasome dysfunction was involved in the BDE-47-induced hepatocyte apoptosis in the mouse liver. Furthermore, our results revealed that troxerutin effectively inhibited hepatocyte apoptosis by restoring oxidative stress-mediated proteasome dysfunction in BDE-47-treated mice. Consequently, troxerutin markedly suppressed endoplasmic reticulum (ER) stress in the livers of the BDE-47-treated mice. The inhibitory effects of troxerutin on ER stress and apoptotic pathways were markedly blunted by treatment with epoxomicin (a selective inhibitor of proteasome). Ultimately, troxerutin dramatically blocked TRAF2-ASK1-JNK signaling and CHOP-mediated apoptosis signaling in the BDE-47-treated mouse livers. This study provides novel mechanistic insights into the toxicity of BDE-47 and indicates that troxerutin might be a candidate for the prevention of and therapy for BDE-47-induced hepatotoxicity. PMID:25639565

  5. Attenuated SAG expression exacerbates 4-hydroxy-2-nonenal-induced apoptosis and hypertrophy of H9c2 cardiomyocytes.

    PubMed

    Park, J H; Lee, J H; Park, J-W

    2015-01-01

    Oxidative stress, associated with the accumulation of reactive oxygen species (ROS), results in numerous and detrimental effects on the myocardium such as the induction of apoptotic cell death, hypertrophy, fibrosis, dysfunction, and dilatation. The product of sensitive to apoptosis gene (SAG) is a RING finger protein that has been shown to have a protective effect against apoptosis induced by oxidative stress in various cell types. The major reactive aldehydic product of lipid peroxidation, 4-hydroxy-2-nonenal (HNE), is believed to be largely responsible for cytopathological effects observed during oxidative stress. In the present study, we showed that the transfection of H9c2 clonal myoblastic cells with small interfering RNA (siRNA) specific for SAG markedly attenuated SAG expression and exacerbates HNE-induced apoptosis and hypertrophy. The knockdown of SAG expression resulted in the modulation of cellular redox status, mitochondrial function, and cellular oxidative damage. Taken together, our results showed that the suppression of SAG expression by siRNA enhanced HNE-induced apoptosis and hypertrophy of cultured cardiomyocytes via the disruption of the cellular redox balance. Given the importance of the SAG protein in the regulation of the redox status of cardiomyocytes, we conclude that this protein may be a potential new target in the development of therapeutic agents for the prevention of cardiovascular diseases. PMID:25850934

  6. Macroautophagy-generated increase of lysosomal amyloid β-protein mediates oxidant-induced apoptosis of cultured neuroblastoma cells

    PubMed Central

    Terman, Alexei; Hallbeck, Martin; Dehvari, Nodi; Cowburn, Richard F.; Benedikz, Eirikur; Kågedal, Katarina; Cedazo-Minguez, Angel; Marcusson, Jan

    2011-01-01

    Increasing evidence suggests the toxicity of intracellular amyloid β-protein (Aβ) to neurons, as well as the involvement of oxidative stress in Alzheimer disease (AD). Here we show that normobaric hyperoxia (exposure of cells to 40% oxygen for five days), and consequent activation of macroautophagy and accumulation of Aβ within lysosomes, induced apoptosis in differentiated SH-SY5Y neuroblastoma cells. Cells under hyperoxia showed: (1) increased numbers of autophagic vacuoles that contained amyloid precursor protein (APP) as well as Aβ monomers and oligomers, (2) increased reactive oxygen species production, and (3) enhanced apoptosis. Oxidant-induced apoptosis positively correlated with cellular Aβ production, being the highest in cells that were stably transfected with APP Swedish KM670/671NL double mutation. Inhibition of γ-secretase, prior and/or in parallel to hyperoxia, suggested that the increase of lysosomal Aβ resulted mainly from its autophagic uptake, but also from APP processing within autophagic vacuoles. The oxidative stress-mediated effects were prevented by macroautophagy inhibition using 3-methyladenine or ATG5 downregulation. Our results suggest that upregulation of macroautophagy and resulting lysosomal Aβ accumulation are essential for oxidant-induced apoptosis in cultured neuroblastoma cells and provide additional support for the interactive role of oxidative stress and the lysosomal system in AD-related neurodegeneration. PMID:22108004

  7. Troxerutin inhibits 2,2',4,4'-tetrabromodiphenyl ether (BDE-47)-induced hepatocyte apoptosis by restoring proteasome function.

    PubMed

    Zhang, Zi-Feng; Shan, Qun; Zhuang, Juan; Zhang, Yan-Qiu; Wang, Xin; Fan, Shao-Hua; Lu, Jun; Wu, Dong-Mei; Hu, Bin; Zheng, Yuan-Lin

    2015-03-18

    Proteasome dysfunction has been associated with the pathogeneses of a variety of diseases and with the neurotoxicities of environmental chemicals; however, whether proteasome dysfunction plays a role in the cellular toxicity of polybrominated diphenyl ethers (PBDEs) has not been investigated to date. Emerging evidence suggests that antioxidants exhibit evident beneficial effects on the cellular toxicity associated with PBDEs. In the present study, we investigated whether troxerutin attenuates BDE-47-induced hepatocyte apoptosis by restoring proteasome function and explored the mechanisms underlying this effect. Our results revealed that proteasome dysfunction was involved in the BDE-47-induced hepatocyte apoptosis in the mouse liver. Furthermore, our results revealed that troxerutin effectively inhibited hepatocyte apoptosis by restoring oxidative stress-mediated proteasome dysfunction in BDE-47-treated mice. Consequently, troxerutin markedly suppressed endoplasmic reticulum (ER) stress in the livers of the BDE-47-treated mice. The inhibitory effects of troxerutin on ER stress and apoptotic pathways were markedly blunted by treatment with epoxomicin (a selective inhibitor of proteasome). Ultimately, troxerutin dramatically blocked TRAF2-ASK1-JNK signaling and CHOP-mediated apoptosis signaling in the BDE-47-treated mouse livers. This study provides novel mechanistic insights into the toxicity of BDE-47 and indicates that troxerutin might be a candidate for the prevention of and therapy for BDE-47-induced hepatotoxicity.

  8. Hypoxia promotes apoptosis of neuronal cells through hypoxia-inducible factor-1α-microRNA-204-B-cell lymphoma-2 pathway

    PubMed Central

    Wang, Xiuwen; Li, Ji; Wu, Dongjin; Bu, Xiangpeng

    2015-01-01

    Neuronal cells are highly sensitive to hypoxia and may be subjected to