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Sample records for spe b-induced apoptosis

  1. Polymyxin B Induces Apoptosis in Kidney Proximal Tubular Cells

    PubMed Central

    Azad, Mohammad A. K.; Finnin, Ben A.; Poudyal, Anima; Davis, Kathryn; Li, Jinhua; Hill, Prue A.; Nation, Roger L.

    2013-01-01

    The nephrotoxicity of polymyxins is a major dose-limiting factor for treatment of infections caused by multidrug-resistant Gram-negative pathogens. The mechanism(s) of polymyxin-induced nephrotoxicity is not clear. This study aimed to investigate polymyxin B-induced apoptosis in kidney proximal tubular cells. Polymyxin B-induced apoptosis in NRK-52E cells was examined by caspase activation, DNA breakage, and translocation of membrane phosphatidylserine using Red-VAD-FMK [Val-Ala-Asp(O-Me) fluoromethyl ketone] staining, a terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) assay, and double staining with annexin V-propidium iodide (PI). The concentration dependence (50% effective concentration [EC50]) and time course for polymyxin B-induced apoptosis were measured in NRK-52E and HK-2 cells by fluorescence-activated cell sorting (FACS) with annexin V and PI. Polymyxin B-induced apoptosis in NRK-52E cells was confirmed by positive labeling from Red-VAD-FMK staining, TUNEL assay, and annexin V-PI double staining. The EC50 (95% confidence interval [CI]) of polymyxin B for the NRK-52E cells was 1.05 (0.91 to 1.22) mM and was 0.35 (0.29 to 0.42) mM for HK-2 cells. At lower concentrations of polymyxin B, minimal apoptosis was observed, followed by a sharp rise in the apoptotic index at higher concentrations in both cell lines. After treatment of NRK-52E cells with 2.0 mM polymyxin B, the percentage of apoptotic cells (mean ± standard deviation [SD]) was 10.9% ± 4.69% at 6 h and reached plateau (>80%) at 24 h, whereas treatment with 0.5 mM polymyxin B for 24 h led to 93.6% ± 5.57% of HK-2 cells in apoptosis. Understanding the mechanism of polymyxin B-induced apoptosis will provide important information for discovering less nephrotoxic polymyxin-like lipopeptides. PMID:23796937

  2. Eriocalyxin B-induced apoptosis in pancreatic adenocarcinoma cells through thiol-containing antioxidant systems and downstream signalling pathways.

    PubMed

    Li, L; Yue, G G L; Pu, J X; Sun, H D; Fung, K P; Leung, P C; Han, Q B; Lau, C B S; Leung, P S

    2014-01-01

    Thiol-containing antioxidant systems play an important role in regulating cellular redox homeostasis. Several anti-cancer agents act by targeting these systems by inducing the production of reactive oxygen species (ROS). Our earlier studies have shown that Eriocalyxin B (EriB), a diterpenoid isolated from Isodon eriocalyx, possesses anti-pancreatic tumour activities in vitro and in vivo. The present study further demonstrated that only thiol-containing antioxidants, N-acetylcysteine (NAC) or dithiothreitol (DTT), inhibited EriB-induced cytotoxicity and apoptosis. EriB suppressed the glutathione and thioredoxin antioxidant systems, thus increasing the intracellular ROS levels and regulating the MAPK, NF?B pathways. Treatment with EriB depleted the intracellular thiol-containing proteins in CAPAN-2 cells. In vivo studies also showed that EriB treatment (2.5 mg/kg) reduced the pancreatic tumour weights significantly in nude mice with increased superoxide levels. Taken together, our results shed important new light on the molecular mechanisms of EriB acting as an apoptogenic agent and its therapeutic potential for pancreatic cancer. PMID:24894173

  3. Eosinophil-specific deletion of I?B? in mice reveals a critical role of NF-?B–induced Bcl-xL for inhibition of apoptosis

    PubMed Central

    Schwartz, Christian; Willebrand, Ralf; Huber, Silke; Rupec, Rudolf A.; Wu, Davina; Locksley, Richard

    2015-01-01

    Eosinophils are associated with type 2 immune responses to allergens and helminths. They release various proinflammatory mediators and toxic proteins on activation and are therefore considered proinflammatory effector cells. Eosinophilia is promoted by the cytokines interleukin (IL)-3, IL-5, and granulocyte macrophage–colony-stimulating factor (GM-CSF) and can result from enhanced de novo production or reduced apoptosis. In this study, we show that only IL-5 induces differentiation of eosinophils from bone marrow precursors, whereas IL-5, GM-CSF, and to a lesser extent IL-3 promote survival of mature eosinophils. The receptors for these cytokines use the common ? chain, which serves as the main signaling unit linked to signal transducer and activator of transcription 5, p38 mitogen-activated protein kinase, and nuclear factor (NF)-?B pathways. Inhibition of NF-?B induced apoptosis of in vitro cultured eosinophils. Selective deletion of I?B? in vivo resulted in enhanced expression of Bcl-xL and reduced apoptosis during helminth infection. Retroviral overexpression of Bcl-xL promoted survival, whereas pharmacologic inhibition of Bcl-xL in murine or human eosinophils induced rapid apoptosis. These results suggest that therapeutic strategies targeting Bcl-xL in eosinophils could improve health conditions in allergic inflammatory diseases. PMID:25862560

  4. Eriocalyxin B induces apoptosis and cell cycle arrest in pancreatic adenocarcinoma cells through caspase- and p53-dependent pathways

    SciTech Connect

    Li, Lin; Institute of Chinese Medicine, The Chinese University of Hong Kong, Hong Kong; State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Hong Kong ; Yue, Grace G.L.; State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Hong Kong ; Lau, Clara B.S.; Institute of Chinese Medicine, The Chinese University of Hong Kong, Hong Kong ; Sun, Handong; Fung, Kwok Pui; Institute of Chinese Medicine, The Chinese University of Hong Kong, Hong Kong; State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Hong Kong ; Leung, Ping Chung; State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Hong Kong ; Han, Quanbin; State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Hong Kong; School of Chinese Medicine, The Hong Kong Baptist University, Hong Kong ; Leung, Po Sing

    2012-07-01

    Pancreatic cancer is difficult to detect early and responds poorly to chemotherapy. A breakthrough in the development of new therapeutic agents is urgently needed. Eriocalyxin B (EriB), isolated from the Isodon eriocalyx plant, is an ent-kaurane diterpenoid with promise as a broad-spectrum anti-cancer agent. The anti-leukemic activity of EriB, including the underlying mechanisms involved, has been particularly well documented. In this study, we demonstrated for the first time EriB's potent cytotoxicity against four pancreatic adenocarcinoma cell lines, namely PANC-1, SW1990, CAPAN-1, and CAPAN-2. The effects were comparable to that of the chemotherapeutic camptothecin (CAM), but with much lower toxicity against normal human liver WRL68 cells. EriB's cytoxicity against CAPAN-2 cells was found to involve caspase-dependent apoptosis and cell cycle arrest at the G2/M phase. Moreover, the p53 pathway was found to be activated by EriB in these cells. Furthermore, in vivo studies showed that EriB inhibited the growth of human pancreatic tumor xenografts in BALB/c nude mice without significant secondary adverse effects. These results suggest that EriB should be considered a candidate for pancreatic cancer treatment. -- Highlights: ? We study Eriocalyxin B (EriB)'s cytotoxic effects on pancreatic cancer cell lines. ? EriB inhibits cell proliferation via mediation of apoptosis and cell cycle arrest. ? The effects are involved in caspase-dependent apoptosis and p53 pathway. ? In vivo study also shows EriB inhibits the growth of human pancreatic tumor. ? EriB can be a good candidate for chemotherapy in pancreatic cancer.

  5. Hemoglobin interaction with GP1b? induces platelet activation and apoptosis: a novel mechanism associated with intravascular hemolysis

    PubMed Central

    Singhal, Rashi; Annarapu, Gowtham K.; Pandey, Ankita; Chawla, Sheetal; Ojha, Amrita; Gupta, Avinash; Cruz, Miguel A.; Seth, Tulika; Guchhait, Prasenjit

    2015-01-01

    Intravascular hemolysis increases the risk of hypercoagulation and thrombosis in hemolytic disorders. Our study shows a novel mechanism by which extracellular hemoglobin directly affects platelet activation. The binding of Hb to glycoprotein1b? activates platelets. Lower concentrations of Hb (0.37–3 ?M) significantly increase the phosphorylation of signaling adapter proteins, such as Lyn, PI3K, AKT, and ERK, and promote platelet aggregation in vitro. Higher concentrations of Hb (3–6 ?M) activate the pro-apoptotic proteins Bak, Bax, cytochrome c, caspase-9 and caspase-3, and increase platelet clot formation. Increased plasma Hb activates platelets and promotes their apoptosis, and plays a crucial role in the pathogenesis of aggregation and development of the procoagulant state in hemolytic disorders. Furthermore, we show that in patients with paroxysmal nocturnal hemoglobinuria, a chronic hemolytic disease characterized by recurrent events of intravascular thrombosis and thromboembolism, it is the elevated plasma Hb or platelet surface bound Hb that positively correlates with platelet activation. PMID:26341739

  6. Hemoglobin interaction with GP1b? induces platelet activation and apoptosis: a novel mechanism associated with intravascular hemolysis.

    PubMed

    Singhal, Rashi; Annarapu, Gowtham K; Pandey, Ankita; Chawla, Sheetal; Ojha, Amrita; Gupta, Avinash; Cruz, Miguel A; Seth, Tulika; Guchhait, Prasenjit

    2015-12-01

    Intravascular hemolysis increases the risk of hypercoagulation and thrombosis in hemolytic disorders. Our study shows a novel mechanism by which extracellular hemoglobin directly affects platelet activation. The binding of Hb to glycoprotein1b? activates platelets. Lower concentrations of Hb (0.37-3 ?M) significantly increase the phosphorylation of signaling adapter proteins, such as Lyn, PI3K, AKT, and ERK, and promote platelet aggregation in vitro. Higher concentrations of Hb (3-6 ?M) activate the pro-apoptotic proteins Bak, Bax, cytochrome c, caspase-9 and caspase-3, and increase platelet clot formation. Increased plasma Hb activates platelets and promotes their apoptosis, and plays a crucial role in the pathogenesis of aggregation and development of the procoagulant state in hemolytic disorders. Furthermore, we show that in patients with paroxysmal nocturnal hemoglobinuria, a chronic hemolytic disease characterized by recurrent events of intravascular thrombosis and thromboembolism, it is the elevated plasma Hb or platelet surface bound Hb that positively correlates with platelet activation. PMID:26341739

  7. Xerophilusin B induces cell cycle arrest and apoptosis in esophageal squamous cell carcinoma cells and does not cause toxicity in nude mice.

    PubMed

    Yao, Ran; Chen, Zhaoli; Zhou, Chengcheng; Luo, Mei; Shi, Xuejiao; Li, Jiagen; Gao, Yibo; Zhou, Fang; Pu, Jianxin; Sun, Handong; He, Jie

    2015-01-23

    Esophageal cancer is the eighth most common cancer in the world and ranks as the sixth leading cause of cancer-related mortality. Esophageal cancer has a poor prognosis partially due to its low sensitivity to chemotherapy agents, and the development of new therapeutic agents is urgently needed. Here, the antitumor activity of a natural ent-kaurane diterpenoid, xerophilusin B (1), which was isolated from Isodon xerophilus, a perennial herb frequently used in Chinese folk medicine for tumor treatment, was investigated. Compound 1 exhibited antiproliferative effects against esophageal squamous cell carcinoma (ESCC) cell lines in a time- and dose-dependent manner with lower toxicity against normal human and murine cell lines. In vivo studies demonstrated that 1 inhibited tumor growth of a human esophageal tumor xenograft in BALB/c nude mice without significant secondary adverse effects, indicating its safety in treating ESCC. Furthermore, 1 induced G2/M cell cycle arrest and promoted apoptosis through mitochondrial cytochrome c-dependent activation of the caspase-9 and caspase-3 cascade pathway in ESCC cell lines. In conclusion, the observations herein reported showed that 1 is a potential chemotherapeutic agent for ESCC and merits further preclinical and clinical investigation for cancer drug development. PMID:25555195

  8. SPE 91413SPE 91413 Anangela Garcia

    E-print Network

    Mohaghegh, Shahab

    INPUT PARAMETERS:INPUT PARAMETERS: #12;SPE Eastern Regional Meeting US Natural Gas Forecasting Model using the state-of-the-art- in intelligent systems US Natural Gas Forecasting Model using the state - Supply of US dry natural gas - Estimated natural gas reserves - US natural gas production - Gross

  9. The chalcone flavokawain B induces G2/M cell-cycle arrest and apoptosis in human oral carcinoma HSC-3 cells through the intracellular ROS generation and downregulation of the Akt/p38 MAPK signaling pathway.

    PubMed

    Hseu, You-Cheng; Lee, Meng-Shiou; Wu, Chi-Rei; Cho, Hsin-Ju; Lin, Kai-Yuan; Lai, Guan-Hua; Wang, Sheng-Yang; Kuo, Yueh-Hsiung; Kumar, K J Senthil; Yang, Hsin-Ling

    2012-03-01

    Chalcones have been described to represent cancer chemopreventive food components that are rich in fruits and vegetables. In this study, we examined the anti-oral cancer effect of flavokawain B (FKB), a naturally occurring chalcone isolated from Alpinia pricei (shell gingers), and revealed its molecular mechanism of action. Treatment of human oral carcinoma (HSC-3) cells with FKB (1.25-10 ?g/mL; 4.4-35.2 ?M) inhibited cell viability and caused G(2)/M arrest through reductions in cyclin A/B1, Cdc2, and Cdc25C levels. Moreover, FKB treatment resulted in the induction of apoptosis, which was associated with DNA fragmentation, mitochondria dysfunction, cytochrome c and AIF release, caspase-3 and caspase-9 activation, and Bcl-2/Bax dysregulation. Furthermore, increased Fas activity and procaspase-8, procaspase-4, and procaspase-12 cleavages were accompanied by death receptor and ER-stress, indicating the involvement of mitochondria, death-receptor, and ER-stress signaling pathways. FKB induces apoptosis through ROS generation as evidenced by the upregulation of oxidative-stress markers HO-1/Nrf2. This mechanism was further confirmed by the finding that the antioxidant N-acetylcysteine (NAC) significantly blocked ROS generation and consequently inhibited FKB-induced apoptosis. Moreover, FKB downregulated the phosphorylation of Akt and p38 MAPK, while their inhibitors LY294002 and SB203580, respectively, induced G(2)/M arrest and apoptosis. The profound reduction in cell number was observed in combination treatment with FKB and Akt/p38 MAPK inhibitors, indicating that the disruption of Akt and p38 MAPK cascades plays a functional role in FKB-induced G(2)/M arrest and apoptosis in HSC-3 cells. PMID:22324429

  10. Human papillomavirus type 16 E6 activates NF-kappaB, induces cIAP-2 expression, and protects against apoptosis in a PDZ binding motif-dependent manner.

    PubMed

    James, Michael A; Lee, John H; Klingelhutz, Aloysius J

    2006-06-01

    Infection with human papillomavirus (HPV) is a critical factor in the pathogenesis of most cervical cancers and some aerodigestive cancers. The HPV E6 oncoprotein from high-risk HPV types contributes to the immortalization and transformation of cells by multiple mechanisms, including degradation of p53, transcriptional activation of human telomerase reverse transcriptase (hTERT), and degradation of several proteins containing PDZ domains. The ability of E6 to bind PDZ domain-containing proteins is independent of p53 degradation or hTERT activation but does correlate with oncogenic potential (R. A. Watson, M. Thomas, L. Banks, and S. Roberts, J. Cell Sci. 116:4925-4934, 2003) and is essential for induction of epithelial hyperplasia in vivo (M. L. Nguyen, M. M. Nguyen, D. Lee, A. E. Griep, and P. F. Lambert, J. Virol. 77:6957-6964, 2003). In this study, we found that HPV type 16 E6 was able to activate NF-kappaB in airway epithelial cells through the induction of nuclear binding activity of p52-containing NF-kappaB complexes in a PDZ binding motif-dependent manner. Transcript accumulation for the NF-kappaB-responsive antiapoptotic gene encoding cIAP-2 and binding of nuclear factors to the proximal NF-kappaB binding site of the cIAP-2 gene promoter are induced by E6 expression. Furthermore, E6 is able to protect cells from TNF-induced apoptosis. All of these E6-dependent phenotypes are dependent on the presence of the PDZ binding motif of E6. Our results imply a role for targeting of PDZ proteins by E6 in NF-kappaB activation and protection from apoptosis in airway epithelial cells. PMID:16699010

  11. PEM/SPE fuel cell

    DOEpatents

    Grot, Stephen Andreas (Henrietta, NY)

    1998-01-01

    A PEM/SPE fuel cell including a membrane-electrode assembly (MEA) having a plurality of oriented filament embedded the face thereof for supporting the MEA and conducting current therefrom to contiguous electrode plates.

  12. PEM/SPE fuel cell

    DOEpatents

    Grot, S.A.

    1998-01-13

    A PEM/SPE fuel cell is described including a membrane-electrode assembly (MEA) having a plurality of oriented filament embedded the face thereof for supporting the MEA and conducting current therefrom to contiguous electrode plates. 4 figs.

  13. Current SPE Hydrodynamic Modeling and Path Forward

    SciTech Connect

    Knight, Earl E.; Rougier, Esteban

    2012-08-14

    Extensive work has been conducted on SPE analysis efforts: Fault effects Non-uniform weathered layer analysis MUNROU: material library incorporation, parallelization, and development of non-locking tets Development of a unique continuum-based-visco-plastic strain-rate-dependent material model With corrected SPE data path is now set for a multipronged approach to fully understand experimental series shot effects.

  14. Fast Track Analysis of Shale Numerical Models A. Kalantari-Dahaghi ,SPE, S. Esmaili, SPE, West Virginia University, S.D. Mohaghegh, SPE, Intelligent Solution

    E-print Network

    Mohaghegh, Shahab

    SPE 162699 Fast Track Analysis of Shale Numerical Models A. Kalantari-Dahaghi ,SPE, S. Esmaili, SPE of SPE copyright. Abstract Latest advances in shale gas reservoir simulation and modeling have made it possible to optimize and enhance the production from organic rich shale gas reservoirs. Reservoir simulator

  15. Biological Response to SPE Exposures

    NASA Technical Reports Server (NTRS)

    Wilson, J. W.; Cucinotta, F. A.; Kim, M.; Shinn, J. L.; Jones, T. D.; Chang, C. K.

    2004-01-01

    It has long been recognized that a single solar particle event (SPE) can produce, over a short period of time, exposures on the order of LD50 for humans under normal physiological conditions. It is further recognized that recovery from injury over the period of exposure would greatly increase the chances of survival (dose rate effects) although such effects were left unquantified. In the present report we use the bioresponse model derived from a broad range of animal and human exposure data for evaluation of troop readiness in tactical nuclear warfare to evaluate the biological risk posed by the solar event of 4 August 1972. The astronaut blood forming organ (BFO) exposure in deep space would have been 2.2 Sv (1.6 Gy) in a space suit, 1.8 Sv (1.3 Gy) in an aluminum pressure vessel, and 0.7 Sv (0.5 Gy) in an equipment room compared to an X-ray mortality threshold of 1.5 Gy (assuming high dose rate). We find BFO dose rate effectiveness factors for this SPE on the order of 3 to 4, greatly reducing the mortality risks for this event. There is an approximate 3 percent chance that an even larger event may occur for which exposures could be 2-4 times higher. Assured survival of the astronaut requires added shelter shielding and a warning system for this event. The required mass of the shelter shield can be greatly reduced by using hydrogenous materials such as polymers, water, food, and other biological materials in its construction. Limitations of the current bioresponse model arise from the exposures taking place in the microgravity environment wherein the immune system is already challenged and the effective mortality threshold may be reduced by a factor of two. Such microgravity effects could greatly affect astronaut risks.

  16. spe433-01 page 1 INTRODUCTION

    E-print Network

    tectonics, rollback, seafloor spreading, subduction. *whamilto@mines.edu #12;2 Hamilton spe433-01 page 2 interactions. Subduction-hinge rollback is the key to viable mechanisms. The Pacific spreads rapidly yet shrinks by rollback, whereas the subduction-free Atlantic widens by slow mid-ocean spreading

  17. Recent advances in SPE (tm) water electrolyzer

    NASA Technical Reports Server (NTRS)

    Mcelroy, James F.

    1993-01-01

    A new cell structure has been introduced into the SPE Water Electrolyzer which has improved overall characteristics significantly. Weight, reliability, and efficiency are the characteristics that are improved the most, with volume having a second order improvement. This paper discusses the capabilities of the new cell structure and the impact it would have in various space applications.

  18. Exact Solutions in a Model of Vertical Gas Migration Dmitriy B. Silin, SPE, Lawrence Berkeley National Laboratory / UC Berkeley; Tad W. Patzek, SPE,

    E-print Network

    Patzek, Tadeusz W.

    Berkeley National Laboratory / UC Berkeley; Tad W. Patzek, SPE, UC Berkeley / Lawrence Berkeley National Laboratory; and Sally M. Benson, SPE, Lawrence Berkeley National Laboratory Copyright 2006, Society

  19. 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

  20. Enniatin B-induced cell death and inflammatory responses in RAW 267.4 murine macrophages

    SciTech Connect

    Gammelsrud, A.; Department of Air Pollution and Noise, Division of Environmental Medicine, Norwegian Institute of Public Health, N-0403 Oslo ; Solhaug, A.; Dendelé, B.; Sandberg, W.J.; Ivanova, L.; Kocbach Bølling, A.; Lagadic-Gossmann, D.; Refsnes, M.; Becher, R.; Eriksen, G.; Holme, J.A.

    2012-05-15

    The mycotoxin enniatin B (EnnB) is predominantly produced by species of the Fusarium genera, and often found in grain. The cytotoxic effect of EnnB has been suggested to be related to its ability to form ionophores in cell membranes. The present study examines the effects of EnnB on cell death, differentiation, proliferation and pro-inflammatory responses in the murine monocyte–macrophage cell line RAW 264.7. Exposure to EnnB for 24 h caused an accumulation of cells in the G0/G1-phase with a corresponding decrease in cyclin D1. This cell cycle-arrest was possibly also linked to the reduced cellular ability to capture and internalize receptors as illustrated by the lipid marker ganglioside GM1. EnnB also increased the number of apoptotic, early apoptotic and necrotic cells, as well as cells with elongated spindle-like morphology. The Neutral Red assay indicated that EnnB induced lysosomal damage; supported by transmission electron microscopy (TEM) showing accumulation of lipids inside the lysosomes forming lamellar structures/myelin bodies. Enhanced levels of activated caspase-1 were observed after EnnB exposure and the caspase-1 specific inhibitor ZYVAD-FMK reduced EnnB-induced apoptosis. Moreover, EnnB increased the release of interleukin-1beta (IL-1?) in cells primed with lipopolysaccharide (LPS), and this response was reduced by both ZYVAD-FMK and the cathepsin B inhibitor CA-074Me. In conclusion, EnnB was found to induce cell cycle arrest, cell death and inflammation. Caspase-1 appeared to be involved in the apoptosis and release of IL-1? and possibly activation of the inflammasome through lysosomal damage and leakage of cathepsin B. -- Highlights: ? The mycotoxin EnnB induced cell cycle arrest, cell death and inflammation. ? The G0/G1-arrest was linked to a reduced ability to internalize receptors. ? EnnB caused lysosomal damage, leakage of cathepsin B and caspase-1 cleavage. ? Caspase-1 was partly involved in both apoptosis and release of IL-1?. ? There was a synergistic action between EnnB and bacterial LPS.

  1. SPE-163690-MS Synthetic, Geomechanical Logs for Marcellus Shale

    E-print Network

    Mohaghegh, Shahab

    . Mohaghegh, SPE, S. Esmaili, SPE, West Virginia University Copyright 2013, Society of Petroleum Engineers have not been reviewed by the Society of Petroleum Engineers and are subject to correction by the author(s). The material does not necessarily reflect any position of the Society of Petroleum Engineers

  2. SPE-139032-PP Field Development Strategies for Bakken Shale Formation

    E-print Network

    Mohaghegh, Shahab

    SPE-139032-PP Field Development Strategies for Bakken Shale Formation S.Zargari, SPE, S s a ckno wle dgm ent of S PE co p yrig ht. Abstract Bakken shale has been subjected to more attention coupled with advancements in horizontal drilling, increased the interest of oil companies for investment

  3. Assay Development for the Discovery of Semaphorin 3B Inducing Agents from Natural Product Sources

    PubMed Central

    Yong, Yeonjoong; Pan, Li; Ren, Yulin; Fatima, Nighat; Ahmed, Safia; Chang, Leng Chee; Zhang, Xiaoli; Kinghorn, A. Douglas; Swanson, Steven M.; Carcache de Blanco, Esperanza J.

    2014-01-01

    Semaphorins are a class of membrane-bound and secreted proteins. They have been found to regulate basic cell functions such as axonal growth cone guidance and recent studies have focused on their effect on tumor progression. Semaphorin 3B (Sema 3B) particularly is a secreted protein that has been known to modulate proliferation and apoptosis, processes that are critical for tumor progression and development. In spite of its importance, there is yet no high-throughput screening assay available to detect or quantify the expression of Sema 3B for natural product anticancer drug discovery purposes. Therefore, the development of a new high-throughput bioassay for the discovery of Sema 3B inducing agents from natural product sources is described herein. A wide variety of pure compounds and extracts from plants and microorganisms has been found suitable for screening using this Sema 3B assay to detect and quantify the effect of Sema 3B inducing agents and thereby identify new selective bioactive Sema 3B lead compounds for anticancer drug discovery and development. Also, this new bioassay procedure is based on a high-throughput platform using an enzyme-linked immunosorbent assay that involves the optimization of sensitivity and selectivity levels as well as accuracy, reproducibility, robustness, and cost effectiveness. PMID:25016954

  4. SPE propulsion electrolyzer for NASA's integrated propulsion test article

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Hamilton Standard has delivered a 3000 PSI SPE Propulsion Electrolyzer Stack and Special Test Fixture to the NASA Lyndon B. Johnson Space Center (JSC) Integrated Propulsion Test Article (IPTA) program in June 1990, per contract NAS9-18030. This prototype unit demonstrates the feasibility of SPE-high pressure water electrolysis for future space applications such as Space Station propulsion and Lunar/Mars energy storage. The SPE-Propulsion Electrolyzer has met or exceeded all IPTA program goals. It continues to function as the primary hydrogen and oxygen source for the IPTA test bed at the NASA/JSC Propulsion and Power Division Thermochemical Test Branch.

  5. OSTEOCYTE APOPTOSIS

    PubMed Central

    Jilka, Robert L.; Noble, Brendon; Weinstein, Robert S.

    2012-01-01

    Apoptotic death of osteocytes was recognized over 15 years ago, but its significance for bone homeostasis has remained elusive. A new paradigm has emerged that invokes osteocyte apoptosis as a critical event in the recruitment of osteoclasts to a specific site in response to skeletal unloading, fatigue damage, estrogen deficiency and perhaps in other states where bone must be removed. This is accomplished by yet to be defined signals emanating from dying osteocytes, which stimulate neighboring viable osteocytes to produce osteoclastogenic cytokines. The osteocyte apoptosis caused by chronic glucocorticoid administration does not increase osteoclasts; however, it does negatively impact maintenance of bone hydration, vascularity, and strength. PMID:23238124

  6. SPE (tm) regenerative hydrogen/oxygen fuel cells for extraterrestrial surface and microgravity applications

    NASA Technical Reports Server (NTRS)

    Mcelroy, J. F.

    1990-01-01

    Viewgraphs on SPE regenerative hydrogen/oxygen fuel cells for extraterrestrial surface and microgravity applications are presented. Topics covered include: hydrogen-oxygen regenerative fuel cell energy storage system; electrochemical cell reactions; SPE cell voltage stability; passive water removal SPE fuel cell; fuel cell performance; SPE water electrolyzers; hydrophobic oxygen phase separator; hydrophilic/electrochemical hydrogen phase separator; and unitized regenerative fuel cell.

  7. RELAP5 posttest calculation of IAEA-SPE-4

    SciTech Connect

    Petelin, S.; Mavko, B.; Parzer, I.; Prosek, A.

    1994-12-31

    The International Atomic Energy Agency`s Fourth Standard Problem Exercise (IAEA-SPE-4) was performed at the PMK-2 facility. The PMK-2 facility is designed to study processes following small- and medium-size breaks in the primary system and natural circulation in VVER-440 plants. The IAEA-SPE-4 experiment represents a cold-leg side small break, similar to the IAEA-SPE-2, with the exception of the high-pressure safety injection being unavailable, and the secondary side bleed and feed initiation. The break valve was located at the dead end of a vertical downcomer, which in fact simulates a break in the reactor vessel itself, and should be unlikely to happen in a real nuclear power plant (NPP). Three different RELAP5 code versions were used for the transient simulation in order to assess the calculations with test results.

  8. SPE in Solar Cycle 24 : Flare and CME characteristic

    NASA Astrophysics Data System (ADS)

    Neflia, Neflia

    SPE is one of the most severe hazards in the space environment. Such events, tend to occur during periods of intense solar activity, and can lead to high radiation doses in short time intervals. The proton enhancements produced by these solar events may last several days and are very hard to predict in advance and they also can cause harm to both satellite and human in space. The most significant sources of proton in the interplanetary medium are both solar flares and interplanetary shocks driven by coronal mass ejections (CMEs). In this study, I try to find the characteristic of Flare and CME that can cause the proton events in interplanetary medium. For my preliminary study, I will search flare characteristic such as class and position as an SPE causes. I also did the research with CME characteristic such as Angular Width (AW) and linier velocity. During solar cycle 24, the solar activity remain very low with several large flare and Halo CME. This low activity also occur on solar proton events in interplanetary medium. From January 2009 to May 2013, there are 25 SPEs with flux range from 12 - 6530 sfu (10 MeV). The solar flare during these events varies from C to X- class flare. From 27 X-class flare that occur during 2009 - May 2013, only 7 flares cause the SPE. Most of active region location are at solar Western Hemisphere (16/25). only 24 from 139 halo CME (AW=360) cause SPE. Although the probability of SPE from all flare and CME during this range of time is small but they have 3 common characteristics, ie, most of the SPE have active region position at Solar Western Hemisphere, the CME have AW=360 and they have a high linier velocity.

  9. Theoretical performance of hydrogen-bromine rechargeable SPE fuel cell

    NASA Technical Reports Server (NTRS)

    Savinell, Robert F.; Fritts, S. D.

    1987-01-01

    A mathematical model was formulated to describe the performance of a hydrogen-bromine fuel cell. Porous electrode theory was applied to the carbon felt flow-by electrode and was coupled to theory describing the solid polymer electrolyte (SPE) system. Parametric studies using the numerical solution to this model were performed to determine the effect of kinetic, mass transfer, and design parameters on the performance of the fuel cell. The results indicate that the cell performance is most sensitive to the transport properties of the SPE membrane. The model was also shown to be a useful tool for scale-up studies.

  10. Pacific cod (Gadus macrocephalus Tilesius, 1810) is an important spe-

    E-print Network

    153 Pacific cod (Gadus macrocephalus Tilesius, 1810) is an important spe- cies in eastern Bering to track large year classes of cod through time. Historically, scales and otoliths have been the two most these structures have experienced limited success in the case of Pacific cod (Kimura and Lyons, 1990). The Pacific

  11. SPE -120174-PP The Future of California's Oil Supply

    E-print Network

    Patzek, Tadeusz W.

    SPE -120174-PP The Future of California's Oil Supply Gregory D. Croft, University of California, Berkeley and Tad W. Patzek, University of Texas, Austin Copyright 2009, Society of Petroleum Engineers have not been reviewed by the Society of Petroleum Engineers and are subject to correction

  12. The sandbar shark, Carcharhinus plumbeus, is a large, coastal spe-

    E-print Network

    387 The sandbar shark, Carcharhinus plumbeus, is a large, coastal spe- cies of the western north (Bigelow and Schroeder, 1948; Springer, 1960). Sandbar sharks are targeted by commercial fisher- ies and account for up to 60% of the large coastal shark landings in U.S. southern waters (NMFS, 1993). Adults

  13. Lack of mitogenic activity of speG- and speG(dys)-positive Streptococcus dysgalactiae subspecies equisimilis isolates from patients with invasive infections.

    PubMed

    Brandt, Claudia M; Schweizer, Klaus G; Holland, Regina; Lütticken, Rudolf; Freyaldenhoven, Bettina S

    2005-12-01

    In recent years, Streptococcus dysgalactiae subspecies equisimilis has been isolated with an increasing frequency as the cause of invasive streptococcal diseases. For 46 S. dysgalactiae subspecies equisimilis isolates from invasive infections and four isolates from superficial infections, the presence of emm/emmL genes and of genes encoding various different streptococcal superantigens was determined by polymerase chain reaction (PCR). Subsequently, PCR products were identified by DNA sequencing, and the expression of mRNA from superantigen genes was assessed by reverse transcriptase-PCR. The mitogenic activity of S. dysgalactiae subspecies equisimilis was assessed by [3H]thymidine incorporation into human lymphocytes and compared with that of Streptococcus agalactiae and Streptococcus pyogenes. All S. dysgalactiae subspecies equisimilis isolates studied harbored an emm/emmL gene. Only in six of the S. dysgalactiae subspecies equisimilis isolates from invasive infections, speG was detected by PCR, two of which were further identified as speGdys by sequencing of the PCR product. None of the S. dysgalactiae subspecies equisimilis isolates harbored any of the genes speA, speB, speC, speF, speH, speI, speJ, speK, speL, speM, smeZ, or ssa of S. pyogenes. In contrast to S. pyogenes, no expression of speG or speGdys mRNA, respectively, was detected in the reverse transcriptase-PCR assay for any of the speG- or speGdys-positive S. dysgalactiae subspecies equisimilis isolates. Moreover, S. dysgalactiae subspecies equisimilis and S. agalactiae revealed no or very low mitogenic activity, while S. pyogenes was a very powerful inducer of proliferative responses. These findings support the hypothesis that the pathogenicity of S. dysgalactiae subspecies equisimilis may be associated in part with the presence of emm/emmL genes, and suggest that the severity of S. dysgalactiae subspecies equisimilis invasive infections is not mediated by superantigen-induced mitogenicity. PMID:16325550

  14. SPE/DOE 27789 Mechanistic Prediction of Foam Displacement in

    E-print Network

    Patzek, Tadeusz W.

    , society of Petroleum Englnee,,, 1".. TM PaPm was PrePa,fl ~or PP?$e"MO" at the SPE/DOE NIn,h Sym@um 0" lm of the SoCiaWof Petroleum Engineers. IF of+ic.m, or members. Pa?ere presented a! % mee!lngs ? wblect in enhanced oil recovery (EOR) techljiqfi"es "imp?iiri"ultimate oil recovery. Foamed gas, though

  15. Glaucocalyxin A and B-induced cell death is related to GSH perturbation in human leukemia HL-60 cells.

    PubMed

    Yang, Wen Hua; Zhang, Zhen; Sima, Yang Hu; Zhang, Jian; Wang, Jian Wen

    2013-10-01

    Glaucocalyxin (Gla) A-C are major ent-kauranoid diterpenoids isolated from Rabdosia japonica var. glaucocalyx, a plant used in Chinese traditional medicine as an antitumor and anti-inflammatory agent. The present investigation was carried out to observe whether cellular reduced glutathione (GSH) plays important roles in Gla -induced cytotoxicity. Among major ent-kauranoid diterpenoids isolated, Gla A and B dose-dependently decreased the growth of HL-60 cells with an IC50 of approximately 6.15 and 5.86 µM at 24 h, respectively. Both Gla A and B could induce apoptosis, G2/M-phase cycle arrest, DNA damage and the accumulation of reactive oxygen species (ROS) in HL-60 cells. Moreover, Gla A, B caused rapid decrease of the intracellular GSH content, while inhibition of cellular GSH synthesis by buthionine sulfoximine (BSO) augmented the induced cytotoxicity and apoptosis in HL-60 cells. On the other hand, the administration of GSH or GSH precursor N-acetyl-cysteine (NAC) could rescue Gla A, B-depleted cellular GSH, and abrogate the induced cytotoxicity, G2/M-phase cycle arrest, DNA damage and ROS accumulation in HL-60 cells. Furthermore, Gla A, B decreased the activity of the GSH-related enzymes including glutathione reductase (GR) and glutathione peroxidase (GPX). These data suggest that the intracellular GSH redox system plays important roles in regulating the Gla A, B-induced cytotoxicity on HL-60 cells. PMID:23796245

  16. Data Release Report for Source Physics Experiments 2 and 3 (SPE-2 and SPE-3) Nevada National Security Site

    SciTech Connect

    Townsend, Margaret; Obi, Curtis

    2015-04-30

    The second Source Physics Experiment shot (SPE-2) was conducted in Nevada on October 25, 2011, at 1900:00.011623 Greenwich Mean Time (GMT). The explosive source was 997 kilograms (kg) trinitrotoluene (TNT) equivalent of sensitized heavy ammonium fuel oil (SHANFO) detonated at a depth of 45.7 meters (m). The third Source Physics Experiment shot (SPE-3) was conducted in Nevada on July 24, 2012, at 1800:00.44835 GMT. The explosive source was 905 kg TNT equivalent of SHANFO detonated at a depth of 45.8 m. Both shots were recorded by an extensive set of instrumentation that includes sensors both at near-field (less than 100 m) and far-field (100 m or greater) distances. The near-field instruments consisted of three-component accelerometers deployed in boreholes at 15, 46, and 55 m depths around the shot and a set of single-component vertical accelerometers on the surface. The far-field network was composed of a variety of seismic and acoustic sensors, including short-period geophones, broadband seismometers, three-component accelerometers, and rotational seismometers at distances of 100 m to 25 kilometers. This report coincides with the release of these data for analysts and organizations that are not participants in this program. This report describes the second and third Source Physics Experiment shots and the various types of near-field and farfield data that are available.This revised document includes reports on baseline shift corrections for the SPE-2 and SPE-3 shots that were missing from the original January 2015 version.

  17. NEAR FIELD MODELING OF SPE1 EXPERIMENT AND PREDICTION OF THE SECOND SOURCE PHYSICS EXPERIMENTS (SPE2)

    SciTech Connect

    Antoun, T; Xu, H; Vorobiev, O; Lomov, I

    2011-10-20

    Motion along joints and fractures in the rock has been proposed as one of the sources of near-source shear wave generation, and demonstrating the validity of this hypothesis is a focal scientific objective of the source physics experimental campaign in the Climax Stock granitic outcrop. A modeling effort has been undertaken by LLNL to complement the experimental campaign, and over the long term provide a validated computation capability for the nuclear explosion monitoring community. The approach involves performing the near-field nonlinear modeling with hydrodynamic codes (e.g., GEODYN, GEODYN-L), and the far-field seismic propagation with an elastic wave propagation code (e.g., WPP). the codes will be coupled together to provide a comprehensive source-to-sensor modeling capability. The technical approach involves pre-test predictions of each of the SPE experiments using their state of the art modeling capabilities, followed by code improvements to alleviate deficiencies identified in the pre-test predictions. This spiral development cycle wherein simulations are used to guide experimental design and the data from the experiment used to improve the models is the most effective approach to enable a transition from the descriptive phenomenological models in current use to the predictive, hybrid physics models needed for a science-based modeling capability for nuclear explosion monitoring. The objective of this report is to describe initial results of non-linear motion predictions of the first two SPE shots in the Climax Stock: a 220-lb shot at a depth of 180 ft (SPE No.1), and a 2570-lb shot at a depth of 150 ft (SPE No.2). The simulations were performed using the LLNL ensemble granite model, a model developed to match velocity and displacement attenuation from HARDHAT, PILE DRIVER, and SHOAL, as well as Russian and French nuclear test data in granitic rocks. This model represents the state of the art modeling capabilities as they existed when the SPE campaign was launched in 2010, and the simulation results presented here will establish a baseline that will be used for gauging progress as planned modeling improvements are implemented during the remainder of the SPE program. The initial simulations were performed under 2D axisymmetric conditions assuming the geologic medium to be a homogeneous half space. However, logging data obtained from the emplacement hole reveal two major faults that intersect the borehole at two different depth intervals (NSTec report, 2011) and four major joint sets. To evaluate the effect of these discrete structures on the wave forms generated they have performed 2D and 3D analysis with a Lagrangian hydrocode, GEODYN-L that shares the same material models with GEODYN but can explicitly take joints and fault into consideration. They discuss results obtained using these two different approaches in this report.

  18. NF?B induces overexpression of bovine FcRn

    PubMed Central

    Cervenak, Judit; Doleschall, Márton; Bender, Balázs; Mayer, Balázs; Schneider, Zita; Doleschall, Zoltán; Zhao, Yaofeng; B?sze, Zsuzsanna; Hammarström, Lennart; Oster, Wolfgang; Kacskovics, Imre

    2013-01-01

    Among the many functions of the neonatal Fc receptor (FcRn) for IgG, it binds to IgG-opsonized antigen complexes and propagates their traffic into lysosomes where antigen processing occurs. We previously reported that transgenic (Tg) mice and rabbits that carry multiple copies and overexpress FcRn have augmented humoral immune responses. Nuclear factor-kappa B (NF?B) is a critical molecule in the signaling cascade in the immune response. NF?B induces human FcRn expression and our previous in silico analysis suggested NF?B binding sites in the promoter region of the bovine (b) FcRn ?-chain gene (FCGRT). Here, we report the identification of three NF?B transcription binding sites in the promoter region of this gene using luciferase reporter gene technology, electromobility shift assay and supershift analysis. Stimulation of primary bovine endothelial cells with the Toll-like receptor-4 ligand lipopolysaccharide (LPS), which mediates its effect via NF?B, resulted in rapid upregulation of the bFcRn expression and a control gene, bovine E-selectin. This rapid bFcRn gene induction was also observed in the spleen of bFcRn Tg mice treated with intraperitoneally injected LPS, analyzed by northern blot analysis. Finally, NF?B-mediated bFcRn upregulation was confirmed at the protein level in macrophages isolated from the bFcRn Tg mice using flow cytometry with a newly developed FcRn specific monoclonal antibody that does not cross-react with the mouse FcRn. We conclude that NF?B regulates bFcRn expression and thus optimizes its functions, e.g., in the professional antigen presenting cells, and contributes to the much augmented humoral immune response in the bFcRn Tg mice. PMID:24492342

  19. Targeting Mitochondria with Avocatin B Induces Selective Leukemia Cell Death.

    PubMed

    Lee, Eric A; Angka, Leonard; Rota, Sarah-Grace; Hanlon, Thomas; Mitchell, Andrew; Hurren, Rose; Wang, Xiao Ming; Gronda, Marcela; Boyaci, Ezel; Bojko, Barbara; Minden, Mark; Sriskanthadevan, Shrivani; Datti, Alessandro; Wrana, Jeffery L; Edginton, Andrea; Pawliszyn, Janusz; Joseph, Jamie W; Quadrilatero, Joe; Schimmer, Aaron D; Spagnuolo, Paul A

    2015-06-15

    Treatment regimens for acute myeloid leukemia (AML) continue to offer weak clinical outcomes. Through a high-throughput cell-based screen, we identified avocatin B, a lipid derived from avocado fruit, as a novel compound with cytotoxic activity in AML. Avocatin B reduced human primary AML cell viability without effect on normal peripheral blood stem cells. Functional stem cell assays demonstrated selectivity toward AML progenitor and stem cells without effects on normal hematopoietic stem cells. Mechanistic investigations indicated that cytotoxicity relied on mitochondrial localization, as cells lacking functional mitochondria or CPT1, the enzyme that facilitates mitochondria lipid transport, were insensitive to avocatin B. Furthermore, avocatin B inhibited fatty acid oxidation and decreased NADPH levels, resulting in ROS-dependent leukemia cell death characterized by the release of mitochondrial proteins, apoptosis-inducing factor, and cytochrome c. This study reveals a novel strategy for selective leukemia cell eradication based on a specific difference in mitochondrial function. PMID:26077472

  20. Data Release Report for Source Physics Experiments 2 and 3 (SPE-2 and SPE-3) Nevada National Security Site

    SciTech Connect

    Townsend, Margaret; Obi, Curtis

    2015-01-26

    The second Source Physics Experiment shot (SPE-2) was conducted in Nevada on October 25, 2011, at 1900:00.011623 Greenwich Mean Time (GMT). The explosive source was 997 kilograms (kg) trinitrotoluene (TNT) equivalent of sensitized heavy ammonium fuel oil (SHANFO) detonated at a depth of 45.7 meters (m). The third Source Physics Experiment shot (SPE-3) was conducted in Nevada on July 24, 2012, at 1800:00.44835 GMT. The explosive source was 905 kg TNT equivalent of SHANFO detonated at a depth of 45.8 m. Both shots were recorded by an extensive set of instrumentation that includes sensors both at near-field (less than 100 m) and far-field (100 m or greater) distances. The near-field instruments consisted of three-component accelerometers deployed in boreholes at 15, 46, and 55 m depths around the shot and a set of single-component vertical accelerometers on the surface. The far-field network was composed of a variety of seismic and acoustic sensors, including short-period geophones, broadband seismometers, three-component accelerometers, and rotational seismometers at distances of 100 m to 25 kilometers. This report coincides with the release of these data for analysts and organizations that are not participants in this program. This report describes the second and third Source Physics Experiment shots and the various types of near-field and far-field data that are available.

  1. Helicobacter pylori and apoptosis.

    PubMed Central

    Moss, S. F.

    1998-01-01

    In an attempt to understand the diverse effects of infection with Helicobacter pylori on epithelial mucosal mass and consequent clinical outcome, the relationship between H. pylori infection and gastric epithelial cellular turnover has been investigated. Our results indicate that H. pylori increases epithelial cell proliferation and apoptosis in vivo, but that infection with bacteria of the cagA genotype leads to relatively more proliferation than apoptosis. This review explores the causes of the induction of apoptosis in gastric epithelial cells by H. pylori and the consequences of alterations in apoptosis to the maintenance of gastric mucosal homeostasis. Images Figure 1 PMID:10378350

  2. SPE 159255-PP Rock Classification from Conventional Well Logs in Hydrocarbon-Bearing

    E-print Network

    Torres-Verdín, Carlos

    SPE 159255-PP Rock Classification from Conventional Well Logs in Hydrocarbon-Bearing Shale Andrew C. The abstract must contain conspicuous acknowledgment of SPE copyright. Abstract This paper introduces a rock typing method for application in hydrocarbon-bearing shale (specifically source rock) reservoirs using

  3. SPE 153843-PP Uncertainty Analysis of a CO2 Sequestration Project Using Surrogate

    E-print Network

    Mohaghegh, Shahab

    the SRM included constructing a reservoir simulation model with a commercial software, history matching. As a result, concerns about the greenhouse gas emission and its impact on global warming and climate change Modeling Technique Shohreh Amini, SPE, West Virginia University, Shahab Mohaghegh, SPE, West Virginia

  4. Solid Polymer Electrolyte (SPE) fuel cell technology, program review, phase 2

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The purpose of the solid polymer electrolyte (SPE) fuel cell program is to advance the SPE fuel cell technology in four target areas. These areas are: (1) reduced fuel cell costs; (2) reduced fuel cell weight; (3) improved fuel cell efficiency; and (4) increased systems compatibility.

  5. Pax3 expression enhances PDGF-B-induced brainstem gliomagenesis and characterizes a subset of brainstem glioma.

    PubMed

    Misuraca, Katherine L; Barton, Kelly L; Chung, Alexander; Diaz, Alexander K; Conway, Simon J; Corcoran, David L; Baker, Suzanne J; Becher, Oren J

    2014-01-01

    High-grade Brainstem Glioma (BSG), also known as Diffuse Intrinsic Pontine Glioma (DIPG), is an incurable pediatric brain cancer. Increasing evidence supports the existence of regional differences in gliomagenesis such that BSG is considered a distinct disease from glioma of the cerebral cortex (CG). In an effort to elucidate unique characteristics of BSG, we conducted expression analysis of mouse PDGF-B-driven BSG and CG initiated in Nestin progenitor cells and identified a short list of expression changes specific to the brainstem gliomagenesis process, including abnormal upregulation of paired box 3 (Pax3). In the neonatal mouse brain, Pax3 expression marks a subset of brainstem progenitor cells, while it is absent from the cerebral cortex, mirroring its regional expression in glioma. Ectopic expression of Pax3 in normal brainstem progenitors in vitro shows that Pax3 inhibits apoptosis. Pax3-induced inhibition of apoptosis is p53-dependent, however, and in the absence of p53, Pax3 promotes proliferation of brainstem progenitors. In vivo, Pax3 enhances PDGF-B-driven gliomagenesis by shortening tumor latency and increasing tumor penetrance and grade, in a region-specific manner, while loss of Pax3 function extends survival of PDGF-B-driven;p53-deficient BSG-bearing mice by 33%. Importantly, Pax3 is regionally expressed in human glioma as well, with high PAX3 mRNA characterizing 40% of human BSG, revealing a subset of tumors that significantly associates with PDGFRA alterations, amplifications of cell cycle regulatory genes, and is exclusive of ACVR1 mutations. Collectively, these data suggest that regional Pax3 expression not only marks a novel subset of BSG but also contributes to PDGF-B-induced brainstem gliomagenesis. PMID:25330836

  6. Method of making MEA for PEM/SPE fuel cell

    DOEpatents

    Hulett, Jay S. (West Henrietta, NY)

    2000-01-01

    A method of making a membrane-electrode-assembly (MEA) for a PEM/SPE fuel cell comprising applying a slurry of electrode-forming material directly onto a membrane-electrolyte film. The slurry comprises a liquid vehicle carrying catalyst particles and a binder for the catalyst particles. The membrane-electrolyte is preswollen by contact with the vehicle before the electrode-forming slurry is applied to the membrane-electrolyte. The swollen membrane-electrolyte is constrained against shrinking in the "x" and "y" directions during drying. Following assembly of the fuel cell, the MEA is rehydrated inside the fuel cell such that it swells in the "z" direction for enhanced electrical contact with contiguous electrically conductive components of the fuel cell.

  7. Calpains, mitochondria, and apoptosis

    PubMed Central

    Smith, Matthew A.; Schnellmann, Rick G.

    2012-01-01

    Mitochondrial activity is critical for efficient function of the cardiovascular system. In response to cardiovascular injury, mitochondrial dysfunction occurs and can lead to apoptosis and necrosis. Calpains are a 15-member family of Ca2+-activated cysteine proteases localized to the cytosol and mitochondria, and several have been shown to regulate apoptosis and necrosis. For example, in endothelial cells, Ca2+ overload causes mitochondrial calpain 1 cleavage of the Na+/Ca2+ exchanger leading to mitochondrial Ca2+ accumulation. Also, activated calpain 1 cleaves Bid, inducing cytochrome c release and apoptosis. In renal cells, calpains 1 and 2 promote apoptosis and necrosis by cleaving cytoskeletal proteins, which increases plasma membrane permeability and cleavage of caspases. Calpain 10 cleaves electron transport chain proteins, causing decreased mitochondrial respiration and excessive activation, or inhibition of calpain 10 activity induces mitochondrial dysfunction and apoptosis. In cardiomyocytes, calpain 1 activates caspase 3 and poly-ADP ribose polymerase during tumour necrosis factor-?-induced apoptosis, and calpain 1 cleaves apoptosis-inducing factor after Ca2+ overload. Many of these observations have been elucidated with calpain inhibitors, but most calpain inhibitors are not specific for calpains or a specific calpain family member, creating more questions. The following review will discuss how calpains affect mitochondrial function and apoptosis within the cardiovascular system. PMID:22581845

  8. SPE-39 Family Proteins Interact with the HOPS Complex and Function in Lysosomal Delivery

    PubMed Central

    Zhu, Guang-dan; Salazar, Gloria; Zlatic, Stephanie A.; Fiza, Babar; Doucette, Michele M.; Heilman, Craig J.; Levey, Allan I.

    2009-01-01

    Yeast and animal homotypic fusion and vacuole protein sorting (HOPS) complexes contain conserved subunits, but HOPS-mediated traffic in animals might require additional proteins. Here, we demonstrate that SPE-39 homologues, which are found only in animals, are present in RAB5-, RAB7-, and RAB11-positive endosomes where they play a conserved role in lysosomal delivery and probably function via their interaction with the core HOPS complex. Although Caenorhabditis elegans spe-39 mutants were initially identified as having abnormal vesicular biogenesis during spermatogenesis, we show that these mutants also have disrupted processing of endocytosed proteins in oocytes and coelomocytes. C. elegans SPE-39 interacts in vitro with both VPS33A and VPS33B, whereas RNA interference of VPS33B causes spe-39–like spermatogenesis defects. The human SPE-39 orthologue C14orf133 also interacts with VPS33 homologues and both coimmunoprecipitates and cosediments with other HOPS subunits. SPE-39 knockdown in cultured human cells altered the morphology of syntaxin 7-, syntaxin 8-, and syntaxin 13-positive endosomes. These effects occurred concomitantly with delayed mannose 6-phosphate receptor-mediated cathepsin D delivery and degradation of internalized epidermal growth factor receptors. Our findings establish that SPE-39 proteins are a previously unrecognized regulator of lysosomal delivery and that C. elegans spermatogenesis is an experimental system useful for identifying conserved regulators of metazoan lysosomal biogenesis. PMID:19109425

  9. The Caenorhabditis elegans spe-39 gene is required for intracellular membrane reorganization during spermatogenesis.

    PubMed Central

    Zhu, Guang-Dan; L'Hernault, Steven W

    2003-01-01

    Caenorhabditis elegans spermatid formation involves asymmetric partitioning of cytoplasm during the second meiotic division. This process is mediated by specialized ER/Golgi-derived fibrous body-membranous organelles (FB-MOs), which have a fibrous body (FB) composed of bundled major sperm protein filaments and a vesicular membranous organelle (MO). spe-39 mutant spermatocytes complete meiosis but do not usually form spermatids. Ultrastructural examination of spe-39 spermatocytes reveals that MOs are absent, while FBs are disorganized and not surrounded by the membrane envelope usually observed in wild type. Instead, spe-39 spermatocytes contain many small vesicles with internal membranes, suggesting they are related to MOs. The spe-39 gene was identified and it encodes a novel hydrophilic protein. Immunofluorescence with a specific SPE-39 antiserum reveals that it is distributed through much of the cytoplasm and not specifically associated with FB-MOs in spermatocytes and spermatids. The spe-39 gene has orthologs in Drosophila melanogaster and humans but no homolog was identified in the yeast genome. This suggests that the specialized membrane biogenesis steps that occur during C. elegans spermatogenesis are part of a conserved process that requires SPE-39 homologs in other metazoan cell types. PMID:14504223

  10. SPE (trademark) Oxygen Generator Assembly (OGA). (Refurbishment of the technology demonstrator LFSPE oxygen generation subsystem)

    NASA Technical Reports Server (NTRS)

    Roy, Robert J.

    1995-01-01

    The SPE Oxygen Generator Assembly (OGA) has been modified to correct operational deficiencies present in the original system, and to effect changes to the system hardware and software such that its operating conditions are consistent with the latest configuration requirements for the International Space Station Alpha (ISSA). The effectiveness of these changes has recently been verified through a comprehensive test program which saw the SPE OGA operate for over 740 hours at various test conditions, including over 690 hours, or approximately 460 cycles, simulating the orbit of the space station. This report documents the changes made to the SPE OGA, presents and discusses the test results from the acceptance test program, and provides recommendations for additional development activities pertinent to evolution of the SPE OGA to a flight configuration. Copies of the test data from the acceptance test program are provided with this report on 3.5 inch diskettes in self-extracting archive files.

  11. Development of an SPE/CE method for analyzing HAAs

    USGS Publications Warehouse

    Zhang, L.; Capel, P.D.; Hozalski, R.M.

    2007-01-01

    The haloacetic acid (HAA) analysis methods approved by the US Environmental Protection Agency involve extraction and derivatization of HAAs (typically to their methyl ester form) and analysis by gas chromatography (GC) with electron capture detection (ECD). Concerns associated with these methods include the time and effort of the derivatization process, use of potentially hazardous chemicals or conditions during methylation, poor recoveries because of low extraction efficiencies for some HAAs or matrix effects from sulfate, and loss of tribromoacetic acid because of decarboxylation. The HAA analysis method introduced here uses solid-phase extraction (SPE) followed by capillary electrophoresis (CE) analysis. The method is accurate, reproducible, sensitive, relatively safe, and easy to perform, and avoids the use of large amounts of solvent for liquid-liquid extraction and the potential hazards and hassles of derivatization. The cost of analyzing HAAs using this method should be lower than the currently approved methods, and utilities with a GC/ECD can perform the analysis in-house.

  12. Pre-shot simulations of far-field ground motion for the Source Physics Experiment (SPE) Explosions at the Climax Stock, Nevada National Security Site: SPE2

    SciTech Connect

    Mellors, R J; Rodgers, A; Walter, W; Ford, S; Xu, H; Matzel, E; Myers, S; Petersson, N A; Sjogreen, B; Hauk, T; Wagoner, J

    2011-10-18

    The Source Physics Experiment (SPE) is planning a 1000 kg (TNT equivalent) shot (SPE2) at the Nevada National Security Site (NNSS) in a granite borehole at a depth (canister centroid) of 45 meters. This shot follows an earlier shot of 100 kg in the same borehole at a depth 60 m. Surrounding the shotpoint is an extensive array of seismic sensors arrayed in 5 radial lines extending out 2 km to the north and east and approximately 10-15 to the south and west. Prior to SPE1, simulations using a finite difference code and a 3D numerical model based on the geologic setting were conducted, which predicted higher amplitudes to the south and east in the alluvium of Yucca Flat along with significant energy on the transverse components caused by scattering within the 3D volume along with some contribution by topographic scattering. Observations from the SPE1 shot largely confirmed these predictions although the ratio of transverse energy relative to the vertical and radial components was in general larger than predicted. A new set of simulations has been conducted for the upcoming SPE2 shot. These include improvements to the velocity model based on SPE1 observations as well as new capabilities added to the simulation code. The most significant is the addition of a new source model within the finite difference code by using the predicted ground velocities from a hydrodynamic code (GEODYN) as driving condition on the boundaries of a cube embedded within WPP which provides a more sophisticated source modeling capability linked directly to source site materials (e.g. granite) and type and size of source. Two sets of SPE2 simulations are conducted, one with a GEODYN source and 3D complex media (no topography node spacing of 5 m) and one with a standard isotropic pre-defined time function (3D complex media with topography, node spacing of 5 m). Results were provided as time series at specific points corresponding to sensor locations for both translational (x,y,z) and rotational components. Estimates of spectral scaling for SPE2 are provided using a modified version of the Mueller-Murphy model. An estimate of expected aftershock probabilities were also provided, based on the methodology of Ford and Walter, [2010].

  13. Characterization of plasma protein binding dissociation with online SPE-HPLC

    PubMed Central

    Li, Ping; Fan, Yiran; Wang, Yunlong; Lu, Yaxin; Yin, Zheng

    2015-01-01

    A novel parameter of relative recovery (Rre) was defined and determined by online SPE-HPLC to characterize plasma protein binding (PPB) kinetics of highly plasma binding drugs. The proportional relationship of Rre with koff of PPB has been established with a new SPE model. A rapid, easy to use method could potentially be used to categorize PK properties of the drug candidates in the decision process of drug discovery and development. PMID:26460813

  14. Characterization of plasma protein binding dissociation with online SPE-HPLC.

    PubMed

    Li, Ping; Fan, Yiran; Wang, Yunlong; Lu, Yaxin; Yin, Zheng

    2015-01-01

    A novel parameter of relative recovery (Rre) was defined and determined by online SPE-HPLC to characterize plasma protein binding (PPB) kinetics of highly plasma binding drugs. The proportional relationship of Rre with koff of PPB has been established with a new SPE model. A rapid, easy to use method could potentially be used to categorize PK properties of the drug candidates in the decision process of drug discovery and development. PMID:26460813

  15. NOVA -Kapteyn Institute ID VST-SPE-OCM-23100-3050

    E-print Network

    Peletier, Reynier

    NOVA - Kapteyn Institute USM ­ OaPd OmegaCAM URD ID VST-SPE-OCM-23100-3050 Issue VERSION 1.1 Date, NOVA programme manager. www.astro.rug.nl/omegacam This document is prepared by the Odoco Document Control System. #12;NOVA - Kapteyn Institute USM ­ OaPd OmegaCAM URD ID VST-SPE-OCM-23100-3050 Issue

  16. Vps33b pathogenic mutations preferentially affect VIPAS39/SPE-39-positive endosomes.

    PubMed

    Tornieri, Karine; Zlatic, Stephanie A; Mullin, Ariana P; Werner, Erica; Harrison, Robert; L'hernault, Steven W; Faundez, Victor

    2013-12-20

    Mutations in Vps33 isoforms cause pigment dilution in mice (Vps33a, buff) and Drosophila (car) and the neurogenic arthrogryposis, renal dysfunction and cholestasis syndrome in humans (ARC1, VPS33B). The later disease is also caused by mutations in VIPAS39, (Vps33b interacting protein, apical-basolateral polarity regulator, SPE-39 homolog; ARC2), a protein that interacts with the HOmotypic fusion and Protein Sorting (HOPS) complex, a tether necessary for endosome-lysosome traffic. These syndromes offer insight into fundamental endosome traffic processes unique to metazoans. However, the molecular and cellular mechanisms underlying these mutant phenotypes remain poorly understood. Here we investigate interactions of wild-type and disease-causing mutations in VIPAS39/SPE-39 and Vps33b by yeast two hybrid, immunoprecipitation and quantitative fluorescent microscopy. We find that although few mutations prevent interaction between VIPAS39/SPE-39 and Vps33b, some mutants fragment VIPAS39/SPE-39-positive endosomes, but all mutants alter the subcellular localization of Vps33b to VIPAS39/SPE-39-positive endosomes. Our data suggest that the ARC syndrome may result through impaired VIPAS39/SPE-39 and Vps33b-dependent endosomal maturation or fusion. PMID:23918659

  17. The Majority of 9,729 Group A Streptococcus Strains Causing Disease Secrete SpeB Cysteine Protease: Pathogenesis Implications.

    PubMed

    Olsen, Randall J; Raghuram, Anjali; Cantu, Concepcion; Hartman, Meredith H; Jimenez, Francisco E; Lee, Susan; Ngo, Ashley; Rice, Kelsey A; Saddington, Deborah; Spillman, Hannaka; Valson, Chandni; Flores, Anthony R; Beres, Stephen B; Long, S Wesley; Nasser, Waleed; Musser, James M

    2015-12-01

    Group A streptococcus (GAS), the causative agent of pharyngitis and necrotizing fasciitis, secretes the potent cysteine protease SpeB. Several lines of evidence suggest that SpeB is an important virulence factor. SpeB is expressed in human infections, protects mice from lethal challenge when used as a vaccine, and contributes significantly to tissue destruction and dissemination in animal models. However, recent descriptions of mutations in genes implicated in SpeB production have led to the idea that GAS may be under selective pressure to decrease secreted SpeB protease activity during infection. Thus, two divergent hypotheses have been proposed. One postulates that SpeB is a key contributor to pathogenesis; the other, that GAS is under selection to decrease SpeB during infection. In order to distinguish between these alternative hypotheses, we performed casein hydrolysis assays to measure the SpeB protease activity secreted by 6,775 GAS strains recovered from infected humans. The results demonstrated that 84.3% of the strains have a wild-type SpeB protease phenotype. The availability of whole-genome sequence data allowed us to determine the relative frequencies of mutations in genes implicated in SpeB production. The most abundantly mutated genes were direct transcription regulators. We also sequenced the genomes of 2,954 GAS isolates recovered from nonhuman primates with experimental necrotizing fasciitis. No mutations that would result in a SpeB-deficient phenotype were identified. Taken together, these data unambiguously demonstrate that the great majority of GAS strains recovered from infected humans secrete wild-type levels of SpeB protease activity. Our data confirm the important role of SpeB in GAS pathogenesis and help end a long-standing controversy. PMID:26416912

  18. Intelligent Upscaling of Static and Dynamic Reservoir Properties V.Gholami, SPE and S.D.Mohaghegh, SPE, West Virginia University

    E-print Network

    Mohaghegh, Shahab

    of SPE copyright. Abstract Rock typing is an essential part of building geological model for an asset. Millions of dollars are invested in logs, core measurements, SCAL studies and geological interpretation do not have crisp boundaries and display overlapping characteristics. During the upscaling process

  19. Predicting Relative-Permeability Curves Directly From Rock Images Dmitriy Silin, SPE, Lawrence Berkeley National Laboratory, and Tad Patzek, SPE, University of Texas, Austin

    E-print Network

    Patzek, Tadeusz W.

    , Lawrence Berkeley National Laboratory, and Tad Patzek, SPE, University of Texas, Austin Copyright 2009 and the rock is water-wet. Maximal inscribed spheres computations characterize the portion of the pore space permeability curves are in good agreement with published data. The input for the proposed procedure can

  20. Closed-Loop Reservoir Management J.D.Jansen, SPE, Shell Intl. E&P (SIEP) and Delft University of Technology (DUT); S.D. Douma, SPE,

    E-print Network

    Van den Hof, Paul

    for presentation at the 2009 SPE Reservoir Simulation Symposium held in The Woodlands, Texas, USA, 2­4 February management', `smart reservoir management' or `closed-loop optimization'. The aim is to maximize reservoir-loop water flooding using real-time production data under uncertain reservoir conditions. The example

  1. Robust Determination of the Pore Space Morphology in Sedimentary Rocks Dmitry B. Silin, SPE, Lawrence Berkeley National Laboratory; Guodong Jin, SPE, UC Berkeley; and

    E-print Network

    Patzek, Tadeusz W.

    SPE 84296 Robust Determination of the Pore Space Morphology in Sedimentary Rocks Dmitry B. Silin the mor- phology (shapes and connectivity) of the pore space of a sedimentary rock. Our approach is based, the proposed algorithm produces a stick-and- ball diagram of the rock pore space. One of distinctive features

  2. Effects of schisandrin B pretreatment on tumor necrosis factor-? induced apoptosis and Hsp70 expression in mouse liver

    PubMed Central

    Ip, Siu-Po; Che, Chun-Tao; Kong, Yun-Cheung; Ko, Kam-Ming

    2001-01-01

    Tumor necrosis factor-? (TNF?) could cause apoptosis in hepatic tissue of d-galactosamine sensitized mice, as evidenced by the increase in the extent of DNA fragmentation. The hepatic apoptosis induced by TNF? was associated with hepatocellular damage as assessed by plasma alanine aminotransferase activity. Schisandrin B (Sch B) pretreatment at daily doses ranging from 0.5 to 2 mmol/kg for 3 days caused a dose-dependent protection against TNF?-induced apoptosis in mice. The hepatoprotection was accompanied by a parallel reduction in the extent of hepatocellular damage. The same Sch B pretreatment regimens increased hepatic Hsp70 level in a dose-dependent manner. The relevance of Sch B–induced increase in Hsp70 expression to the prevention of TNF?-triggered hepatic apoptosis remains to be elucidated. PMID:11525242

  3. Metals and apoptosis: recent developments.

    PubMed

    Rana, Suresh Vir Singh

    2008-01-01

    Apoptosis, also known as programmed cell death is a highly regulated and crucial process found in all multicellular organisms. It is not only implicated in regulatory mechanisms of cells, but has been attributed to a number of diseases, i.e. inflammation, malignancy, autoimmunity and neurodegeneration. A variety of toxins can induce apoptosis. Carcinogenic transition metals, viz. cadmium, chromium and nickel promote apoptosis along with DNA base modifications, strand breaks and rearrangements. Generation of reactive oxygen species, accumulation of Ca(2+), upregulation of caspase-3, down regulation of bcl-2, and deficiency of p-53 lead to arsenic-induced apoptosis. In the case of cadmium, metallothionein expression determines the choice between apoptosis and necrosis. Reactive oxygen species (ROS) and p53 contribute in apoptosis caused by chromium. Immuno suppressive mechanisms contribute in lead-induced apoptosis whereas in the case of mercury, p38 mediated caspase activation regulate apoptosis. Nickel kills the cells by apoptotic pathways. Copper induces apoptosis by p53 dependent and independent pathways. Beryllium stimulates the formation of ROS that play a role in Be-induced macrophage apoptosis. Selenium induces apoptosis by producing superoxide that activates p53. Thus, disorders of apoptosis may play a critical role in some of the most debilitating metal-induced afflictions including hepatotoxicity, renal toxicity, neurotoxicity, autoimmunity and carcinogenesis. An understanding of metal-induced apoptosis will be helpful in the development of preventive molecular strategies. PMID:19013355

  4. Apoptosis Versus Cell Differentiation

    PubMed Central

    Lanneau, David; de Thonel, Aurelie; Maurel, Sebastien; Didelot, Celine

    2007-01-01

    Heat shock proteins HSP27, HSP70 and HSP90 are molecular chaperones whose expression is increased after many different types of stress. They have a protective function helping the cell to cope with lethal conditions. The cytoprotective function of HSPs is largely explained by their anti-apoptotic function. HSPs have been shown to interact with different key apoptotic proteins. As a result, HSPs can block essentially all apoptotic pathways, most of them involving the activation of cystein proteases called caspases. Apoptosis and differentiation are physiological processes that share many common features, for instance, chromatin condensation and the activation of caspases are frequently observed. It is, therefore, not surprising that many recent reports imply HSPs in the differentiation process. This review will comment on the role of HSP90, HSP70 and HSP27 in apoptosis and cell differentiation. HSPs may determine de fate of the cells by orchestrating the decision of apoptosis versus differentiation. PMID:19164900

  5. Spaceflight Associated Apoptosis

    NASA Technical Reports Server (NTRS)

    Ichiki, Albert T.; Gibson, Linda A.; Allebban, Zuhair

    1996-01-01

    Lymphoid tissues have been shown to atrophy in rats flown on Russian spaceflights. Histological examination indicated evidence for cell degradation. Lymphoid tissues from rats flown on Spacelab Life Sciences-2 mission were analyzed for apoptosis by evidence of fragmented lymphocytes, which could be engulfed by macrophages, or DNA strand breaks using the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay. Apoptosis was not detected in the thymus and spleen collected inflight or from the synchronous ground rats but was detected in the thymus, spleen and inguinal lymph node of the flight animals on recovery. These results indicate that the apoptosis observed in the lymphatic tissues of the rats on recovery could have been induced by the gravitational stress of reentry, corroborating the findings from the early space-flight observations.

  6. Accepted by ESO Technical HAWK-I/GRAAL Template Design VLT-SPE-ESO-22000-5949 ii

    E-print Network

    Siebenmorgen, Ralf

    Accepted by ESO Technical Archive #12;HAWK-I/GRAAL Template Design VLT-SPE-ESO-22000-5949 ii Change for signature, RSI #12;HAWK-I/GRAAL Template Design VLT-SPE-ESO-22000-5949 iii Contents 1 Introduction 1 1 . . . . . . . . . . . . . . . . . . . . . . . . . . 31 #12;HAWK-I/GRAAL Template Design VLT-SPE-ESO-22000-5949 iv 4.4.7 HAWKI img tec Filter

  7. Transforming Growth Factor b-Induced Superficial Zone Protein Accumulation in the Surface Zone

    E-print Network

    Athanasiou, Kyriacos

    Transforming Growth Factor b-Induced Superficial Zone Protein Accumulation in the Surface Zone of Articular Cartilage Is Dependent on the Cytoskeleton Sean M. McNary, PhD,1 Kyriacos A. Athanasiou, PhD, PE,1 protein (SZP), a lubricating proteoglycan that reduces the coefficient of friction of articular cartilage

  8. PHARMACOLOGIC PROBING OF AMPHOTERICIN B-INDUCED RENAL DYSFUNCTION IN THE NEONATAL RAT

    EPA Science Inventory

    Pharmacologic Probing of Amphotericin B-Induced Renal Dysfunction in the Neonatal Rat. Gray, J.A., and Kavlock, R.J. (1988). Toxicol. Appl. Pharmacol. 93, 360-368. Acetazolamide, furosemide, chlorothiazide, and amiloride pharmacologic agents that act primarily in the proximal tub...

  9. Arrestins in Apoptosis

    PubMed Central

    Kook, Seunghyi; Gurevich, Vsevolod V.; Gurevich, Eugenia V.

    2015-01-01

    Programmed cell death (apoptosis) is a coordinated set of events eventually leading to the massive activation of specialized proteases (caspases) that cleave numerous substrates, orchestrating fairly uniform biochemical changes than culminate in cellular suicide. Apoptosis can be triggered by a variety of stimuli, from external signals or growth factor withdrawal to intracellular conditions, such as DNA damage or ER stress. Arrestins regulate many signaling cascades involved in life-or-death decisions in the cell, so it is hardly surprising that numerous reports document the effects of ubiquitous nonvisual arrestins on apoptosis under various conditions. Although these findings hardly constitute a coherent picture, with the same arrestin subtypes, sometimes via the same signaling pathways, reported to promote or inhibit cell death, this might reflect real differences in pro- and antiapoptotic signaling in different cells under a variety of conditions. Recent finding suggests that one of the nonvisual subtypes, arrestin-2, is specifically cleaved by caspases. Generated fragment actively participates in the core mechanism of apoptosis: it assists another product of caspase activity, tBID, in releasing cytochrome C from mitochondria. This is the point of no return in committing vertebrate cells to death, and the aspartate where caspases cleave arrestin-2 is evolutionary conserved in vertebrate, but not in invertebrate arrestins. In contrast to wild-type arrestin-2, its caspase-resistant mutant does not facilitate cell death. PMID:24292837

  10. Senescence Apoptosis methyltransferase

    E-print Network

    Utrecht, Universiteit

    Oncogenic stress ARF MDM2 p53 Senescence Apoptosis DNA methyltransferase inhibitors to reactivate testing (for example, DNA methyltransferase inhibitors). possibly of other tumour-suppressor genes, might). p53 gene therapy DNA damage, other stresses of tumour shrinkage: a rapid, non-apoptotic clearance

  11. Cleavage of Antigen-Bound Immunoglobulin G by SpeB Contributes to Streptococcal Persistence in Opsonizing Blood

    PubMed Central

    Eriksson, Anna; Norgren, Mari

    2003-01-01

    Group A streptococci (GAS) express a superantigen, SpeB, having cysteine protease activity. SpeB exhibits several properties that might contribute to virulence, the most recently discovered being the ability to cleave immunoglobulin G (IgG) in a manner similar to that of papain. In the present study, we confirmed this latter finding and found that the irreversible inhibition of SpeB protease activity completely abolishes IgG cleavage. SpeB cleavage of IgG was not species restricted since SpeB cleaved both human, rabbit, and mouse IgG. In order to investigate the nature of the SpeB cleavage of IgG, antibodies were immobilized prior to exposure to SpeB, either by unspecific binding of the Fc to GAS surface proteins or by antigen-specific binding. Analysis of the IgG molecules by SDS-PAGE showed that SpeB could cleave antigen-bound antibodies, while the IgG bound to IgG-binding proteins was protected from cleavage. In a phagocytosis assay using whole blood, the M49 GAS strain NZ131 showed a significantly higher survival than its isogenic speB mutant. Furthermore, the addition of extracellular supernatant derived from an overnight culture of native NZ131 increased the survival of its isogenic speB derivative. This indicates that SpeB's ability to cleave off the Fc part of antigen-bound IgG contributes to GAS escape from opsonophagocytosis while not interfering with the formation of a host-like coat by unspecific IgG binding. PMID:12496168

  12. Glufosinate ammonium clean-up procedure from water samples using SPE

    NASA Astrophysics Data System (ADS)

    Tayeb M., A.; Ismail B., S.; Mardiana-Jansar, K.; Ta, Goh Choo; Agustar, Hani Kartini

    2015-09-01

    For the determination of glufosinate ammonium residue in soil and water samples, different solid phase extraction (SPE) sorbent efficiency was studied. Four different SPE sorbents i.e.: CROMABOND PS-H+, CROMABOND PS-OH-, ISOLUTE ENV+, Water Sep-Pak and OASIS HLB were used. Sample clean-up performance was evaluated using high performance liquid chromatography (Agilent 1220 infinity LC) with fluorescence detector. Detection of FMO-derivatives was done at ? ex = 260 nm and ? em= 310 nm. OASIS HLB column was the most suitable for the clean-up in view of the overall feasibility of the analysis.

  13. Theoretical performance of hydrogen-bromine rechargeable SPE fuel cell. [Solid Polymer Electrolyte

    NASA Technical Reports Server (NTRS)

    Savinell, R. F.; Fritts, S. D.

    1988-01-01

    A mathematical model was formulated to describe the performance of a hydrogen-bromine fuel cell. Porous electrode theory was applied to the carbon felt flow-by electrode and was coupled to theory describing the solid polymer electrolyte (SPE) system. Parametric studies using the numerical solution to this model were performed to determine the effect of kinetic, mass transfer, and design parameters on the performance of the fuel cell. The results indicate that the cell performance is most sensitive to the transport properties of the SPE membrane. The model was also shown to be a useful tool for scale-up studies.

  14. Evading apoptosis in cancer

    PubMed Central

    Fernald, Kaleigh

    2013-01-01

    Carcinogenesis is a mechanistically complex and variable process with a plethora of underlying genetic causes. Cancer development consists of a multitude of steps that occur progressively starting with initial driver mutation(s), to tumorigenesis, and ultimately metastasis. During these transitions, cancer cells accumulate a series of genetic alterations that confer upon the cells an unwarranted survival and proliferative advantage. During the course of development, however, cancer cells also encounter a physiologically ubiquitous cellular program that aims to eliminate damaged or abnormal cells: Apoptosis. Thus, it is essential that cancer cells acquire instruments to circumvent programmed cell death. Here we discuss emerging evidence indicating how cancer cells adopt various strategies to override apoptosis including amplifying the anti-apoptotic machinery, downregulating the pro-apoptotic program, or both. PMID:23958396

  15. cDNA cloning, functional expression and antifungal activities of a dimeric plant defensin SPE10 from Pachyrrhizus erosus seeds.

    PubMed

    Song, Xiaomin; Wang, Jing; Wu, Fang; Li, Xu; Teng, Maikun; Gong, Weimin

    2005-01-01

    SPE10 is an antifungal protein isolated from the seeds of Pachyrrhizus erosus. cDNA encoding a 47 amino acid peptide was cloned by RT-PCR and the gene sequence proved SPE10 to be a new member of plant defensin family. The synthetic cDNA with codons preferred in yeast was cloned into the pPIC9 plasmid directly in-frame with the secretion signal alpha-mating factor, and highly expressed in methylotrophic Pichia pastoris. Activity assays showed the recombinant SPE10 inhibited specifically the growth of several pathogenic fungi as native SPE10. Circular dichroism and fluorescence spectroscopy analysis indicated that the native and recombinant protein should have same folding, though there are eight cystein residues in the sequence. Several evidence suggested SPE10 should be the first dimeric plant defensin reported so far. PMID:15821865

  16. NGFI-B targets mitochondria and induces cardiomyocyte apoptosis in restraint-stressed rats by mediating energy metabolism disorder

    PubMed Central

    Wang, XinXing; Liu, XiaoHua; Kong, RuiRui; Zhan, Rui; Wang, XiaoMing; Leng, Xue; Gong, JingBo; Duan, Meng; Wang, LiQun; Wu, Lei

    2009-01-01

    NGFI-B/Nur77/TR3, originally identified as an immediate-early gene rapidly induced by serum and growth factors, is a member of the steroid hormone nuclear receptor superfamily with no identified endogenous ligand. NGFI-B induces apoptosis in a number of cell lineages exposed to proapoptotic stimuli by directly targeting the mitochondria, inducing cytochrome c release. The present study was designed to determine the role of NGFI-B in cardiomyocytes of restraint-stressed rats. The NGFI-B content was increased in mitochondria and reduced in plasma as apoptosis increased. Analysis showed that NGFI-B induces cardiomyocyte apoptosis in restraint-stressed rats by mediating mitochondrial energy metabolism disorder. Several novel mitochondrial proteins, which correlate with NGFI-B, were reported in cardiomyocyte apoptosis of restraint-stressed rats. Five proteins associated with NGFI-B participate directly in mitochondrial energy metabolism. Studies of mitochondrial respiratory efficiency and ATP synthase activity strongly support the findings. These results provide significant information for comprehensively understanding the cellular mechanism of cardiovascular diseases. PMID:19412742

  17. The Immunoglobulin-like Gene spe-45 Acts during Fertilization in Caenorhabditis elegans like the Mouse Izumo1 Gene.

    PubMed

    Nishimura, Hitoshi; Tajima, Tatsuya; Comstra, Heather Skye; Gleason, Elizabeth J; L'Hernault, Steven W

    2015-12-21

    The Caenorhabditis elegans spe-9 class genes, which show specific or predominant expression in the male germline, are indispensable for fertilization [1, 2]. However, due to the rapid evolution of genes involved in reproduction, we do not currently know if there are spe-9 class genes in mammals that play similar roles during fertilization to those found in C. elegans. In mice, the Izumo1 gene encodes a sperm-specific transmembrane (TM) protein with a single immunoglobulin (Ig)-like domain that is absolutely required for gamete fusion [3, 4]. In this study, we hypothesized that C. elegans has a new member of the spe-9 class genes coding for an IZUMO1-like protein. We screened C. elegans microarray data [5, 6] to identify male germline-enriched genes that encode membrane proteins with Ig-like domains. A deletion (tm3715) in one such gene (F28D1.8) caused hermaphrodites to show a male germline-dependent self-sterility, so we have named it spe-45. Mutant spe-45 worms seemed to normally undergo spermatogenesis (spermatid production by meiosis) and spermiogenesis (spermatid activation into actively motile spermatozoa). spe-45 mutant spermatozoa, however, could not complete gamete fusion, which is a characteristic of all spe-9 class mutants [1, 2]. Moreover, spe-45 self-sterile worms were rescued by a transgene expressing chimeric SPE-45 protein in which its Ig-like domain was replaced by the Ig-like domain from mouse IZUMO1. Hence, C. elegans SPE-45 and mouse IZUMO1 appear to have retained a common function(s) that is required during fertilization. PMID:26671669

  18. The Marine Mammal Protection Act (MMPA) prohibits the take of all marine mammal spe-

    E-print Network

    The Marine Mammal Protection Act (MMPA) prohibits the take of all marine mammal spe- cies in U, or kill any marine mammal." HarassmentHarassment is defined in the MMPA as "any act of pursuit, torment, or annoyance which has the potential to injure a marine mammal or marine mammal stock in the wild; or has

  19. SPE-167897-MS Pattern Recognition and Data-Driven Analytics for Fast and Accurate

    E-print Network

    Mohaghegh, Shahab

    , Society of Petroleum Engineers This paper was prepared for presentation at the SPE Intelligent Energy by the author(s). Contents of the paper have not been reviewed by the Society of Petroleum Engineers of the Society of Petroleum Engineers, its officers, or members. Electronic reproduction, distribution

  20. Estuaries are highly productive habi-tats that support a diversity of spe-

    E-print Network

    186 Estuaries are highly productive habi- tats that support a diversity of spe- cies, but have coastline. Fjord estuaries differ from other estuar- ies by possessing a deep inner basin that is separated from continental shelf waters by a shallow sill near the mouth of the estuary. Although some

  1. Surface Signature Characterization at SPE through Ground-Proximal Methods: Methodology Change and Technical Justification

    SciTech Connect

    Schultz-Fellenz, Emily S.

    2015-09-09

    A portion of LANL’s FY15 SPE objectives includes initial ground-based or ground-proximal investigations at the SPE Phase 2 site. The area of interest is the U2ez location in Yucca Flat. This collection serves as a baseline for discrimination of surface features and acquisition of topographic signatures prior to any development or pre-shot activities associated with SPE Phase 2. Our team originally intended to perform our field investigations using previously vetted ground-based (GB) LIDAR methodologies. However, the extended proposed time frame of the GB LIDAR data collection, and associated data processing time and delivery date, were unacceptable. After technical consultation and careful literature research, LANL identified an alternative methodology to achieve our technical objectives and fully support critical model parameterization. Very-low-altitude unmanned aerial systems (UAS) photogrammetry appeared to satisfy our objectives in lieu of GB LIDAR. The SPE Phase 2 baseline collection was used as a test of this UAS photogrammetric methodology.

  2. There were 3 changes to the Spe-cies of Concern list in Fiscal Year

    E-print Network

    skate and night shark were removed from the pro- gram based on findings that they no longer met program criteria. Bask- ing sharks in the North Pacific Ocean were added based on con- cerns on their status sawfish were proposed for Endangered Spe- cies Act listing, and bumphead parrotfish and Hawaiian reef

  3. Galangin (3,5,7-Trihydroxyflavone) Shields Human Keratinocytes from Ultraviolet B-Induced Oxidative Stress

    PubMed Central

    Madduma Hewage, Susara Ruwan Kumara; Piao, Mei Jing; Kim, Ki Cheon; Cha, Ji Won; Han, Xia; Choi, Yung Hyun; Chae, Sungwook; Hyun, Jin Won

    2015-01-01

    Most skin damage caused by ultraviolet B (UVB) radiation is owing to the generation of reactive oxygen species. Phytochemicals can act as antioxidants against UVB-induced oxidative stress. This study investigated the protective effects of the flavone galangin against UVB-induced oxidative damage in human keratinocytes. Galangin efficiently scavenged free radicals and reduced UVB-induced damage to cellular macromolecules, such as DNA, lipids, and proteins. Furthermore, galangin rescued cells undergoing apoptosis induced by UVB radiation via recovering mitochondrial polarization and down-regulating apoptotic proteins. These results showed that galangin protects human keratinocytes against UVB radiation-induced cellular damage and apoptosis via its antioxidant effects. PMID:25767685

  4. Hindlimb Suspension and SPE-Like Radiation Impairs Clearance of Bacterial Infections

    PubMed Central

    Li, Minghong; Holmes, Veronica; Zhou, Yu; Ni, Houping; Sanzari, Jenine K.; Kennedy, Ann R.; Weissman, Drew

    2014-01-01

    A major risk of extended space travel is the combined effects of weightlessness and radiation exposure on the immune system. In this study, we used the hindlimb suspension model of microgravity that includes the other space stressors, situational and confinement stress and alterations in food intake, and solar particle event (SPE)-like radiation to measure the combined effects on the ability to control bacterial infections. A massive increase in morbidity and decrease in the ability to control bacterial growth was observed using 2 different types of bacteria delivered by systemic and pulmonary routes in 3 different strains of mice. These data suggest that an astronaut exposed to a strong SPE during extended space travel is at increased risk for the development of infections that could potentially be severe and interfere with mission success and astronaut health. PMID:24454913

  5. Copyright 2002, Society of Petroleum Engineers Inc. This paper was prepared for presentation at the SPE Annual Technical Conference and

    E-print Network

    Torres-Verdín, Carlos

    Copyright 2002, Society of Petroleum Engineers Inc. This paper was prepared for presentation at the SPE Annual Technical Conference and Exhibition held in San Antonio, Texas, 29 September­2 October 2002

  6. The Crystal Structure of Escherichia coli Spermidine Synthase SpeE Reveals a Unique Substrate-binding Pocket

    SciTech Connect

    Zhou, X.; Chua, T; Tkaczuk, K; Bujnicki, J; Sivaraman, J

    2010-01-01

    Polyamines are essential in all branches of life. Biosynthesis of spermidine, one of the most ubiquitous polyamines, is catalyzed by spermidine synthase (SpeE). Although the function of this enzyme from Escherichia coli has been thoroughly characterized, its structural details remain unknown. Here, we report the crystal structure of E. coli SpeE and study its interaction with the ligands by isothermal titration calorimetry and computational modelling. SpeE consists of two domains - a small N-terminal {beta}-strand domain, and a C-terminal catalytic domain that adopts a canonical methyltransferase (MTase) Rossmann fold. The protein forms a dimer in the crystal and in solution. Structural comparison of E. coli SpeE to its homologs reveals that it has a large and unique substrate-binding cleft that may account for its lower amine substrate specificity.

  7. Cholesterol oxidase from Bordetella species promotes irreversible cell apoptosis in lung adenocarcinoma by cholesterol oxidation

    PubMed Central

    Liu, J; Xian, G; Li, M; Zhang, Y; Yang, M; Yu, Y; Lv, H; Xuan, S; Lin, Y; Gao, L

    2014-01-01

    Cholesterol oxidase (COD), an enzyme catalyzing the oxidation of cholesterol, has been applied to track the distribution of membrane cholesterol. Little investigations about the effect of COD on tumor cells have been performed. In the present study, we provided evidence that COD from Bordetella species (COD-B), induced apoptosis of lung cancer cells in vitro and in vivo. COD-B treatment inhibited Akt and ERK1/2 phosphorylation in dose- and time-dependent manner, which was not reversed and was even aggravated by cholesterol addition. Further investigation indicated that COD-B treatment promoted the generation of reactive oxygen species (ROS) and that cholesterol addition further elevated ROS levels. Moreover, COD-B treatment resulted in JNK and p38 phosphorylation, downregulation of Bcl-2, upregulation of Bax, activated caspase-3 and cytochrome C release, which likely responded to freshly produced hydrogen peroxide that accompanied cholesterol oxidation. Catalase pretreatment could only partially prevent COD-B-induced events, suggesting that catalase inhibited H2O2-induced signal transduction but had little effect on signal pathways involved in cholesterol depletion. Our results demonstrated that COD-B led to irreversible cell apoptosis by decreasing cholesterol content and increasing ROS level. In addition, COD-B may be a promising candidate for a novel anti-tumor therapy. PMID:25118932

  8. Overview of passive Chemcatcher sampling with SPE pretreatment suitable for the analysis of NPEOs and NPs.

    PubMed

    Ahkola, Heidi; Herve, Sirpa; Knuutinen, Juha

    2013-03-01

    The European Union Water Framework Directive (WFD; 2000/60/EC) is an important piece of environmental legislation that protects rivers, lakes, coastal waters and groundwaters (EC 2000). The implementation of the WFD requires the establishment and use of novel and low-cost monitoring programmes, and several methods, e.g. passive sampling, have been developed to make the sampling process more representative compared to spot sampling. This review considers passive sampling methods focusing mainly on a passive sampler named Chemcatcher®, which has been used for monitoring several harmful compounds in aquatic environments. Also, the sample treatment and analysis of nonylphenol ethoxylates (NPEOs) and nonylphenol (NPs) from water using solid phase extraction (SPE) is briefly summarized. The procedure of Chemcatcher passive sampling is quite similar to that of the SPE extraction since it concentrates the studied compounds from water as well. After sampling, the accumulated substances are extracted from the receiving phase of the sampler. The concentrations of NPEOs and NPs are currently monitored by taking conventional spot samples; SPE can be successfully used as a pretreatment procedure. Chemcatcher® passive sampling technique is a simple and useful monitoring tool and can be applied to new chemicals, such as NPEOs and NPs in aquatic environments. PMID:22983602

  9. Comparison of Radiation Transport Codes, HZETRN, HETC and FLUKA, Using the 1956 Webber SPE Spectrum

    NASA Technical Reports Server (NTRS)

    Heinbockel, John H.; Slaba, Tony C.; Blattnig, Steve R.; Tripathi, Ram K.; Townsend, Lawrence W.; Handler, Thomas; Gabriel, Tony A.; Pinsky, Lawrence S.; Reddell, Brandon; Clowdsley, Martha S.; Singleterry, Robert C.; Norbury, John W.; Badavi, Francis F.; Aghara, Sukesh K.

    2009-01-01

    Protection of astronauts and instrumentation from galactic cosmic rays (GCR) and solar particle events (SPE) in the harsh environment of space is of prime importance in the design of personal shielding, spacec raft, and mission planning. Early entry of radiation constraints into the design process enables optimal shielding strategies, but demands efficient and accurate tools that can be used by design engineers in every phase of an evolving space project. The radiation transport code , HZETRN, is an efficient tool for analyzing the shielding effectiveness of materials exposed to space radiation. In this paper, HZETRN is compared to the Monte Carlo codes HETC-HEDS and FLUKA, for a shield/target configuration comprised of a 20 g/sq cm Aluminum slab in front of a 30 g/cm^2 slab of water exposed to the February 1956 SPE, as mode led by the Webber spectrum. Neutron and proton fluence spectra, as well as dose and dose equivalent values, are compared at various depths in the water target. This study shows that there are many regions where HZETRN agrees with both HETC-HEDS and FLUKA for this shield/target configuration and the SPE environment. However, there are also regions where there are appreciable differences between the three computer c odes.

  10. Substrate-Induced Allosteric Change in the Quaternary Structure of the Spermidine N-Acetyltransferase SpeG.

    PubMed

    Filippova, Ekaterina V; Weigand, Steven; Osipiuk, Jerzy; Kiryukhina, Olga; Joachimiak, Andrzej; Anderson, Wayne F

    2015-11-01

    The spermidine N-acetyltransferase SpeG is a dodecameric enzyme that catalyzes the transfer of an acetyl group from acetyl coenzyme A to polyamines such as spermidine and spermine. SpeG has an allosteric polyamine-binding site and acetylating polyamines regulate their intracellular concentrations. The structures of SpeG from Vibrio cholerae in complexes with polyamines and cofactor have been characterized earlier. Here, we present the dodecameric structure of SpeG from V. cholerae in a ligand-free form in three different conformational states: open, intermediate and closed. All structures were crystallized in C2 space group symmetry and contain six monomers in the asymmetric unit cell. Two hexamers related by crystallographic 2-fold symmetry form the SpeG dodecamer. The open and intermediate states have a unique open dodecameric ring. This SpeG dodecamer is asymmetric except for the one 2-fold axis and is unlike any known dodecameric structure. Using a fluorescence thermal shift assay, size-exclusion chromatography with multi-angle light scattering, small-angle X-ray scattering analysis, negative-stain electron microscopy and structural analysis, we demonstrate that this unique open dodecameric state exists in solution. Our combined results indicate that polyamines trigger conformational changes and induce the symmetric closed dodecameric state of the protein when they bind to their allosteric sites. PMID:26410587

  11. Apoptosis induced by parasitic diseases

    PubMed Central

    2010-01-01

    Fatalities caused by parasitic infections often occur as a result of tissue injury that results from a form of host-cell death known as apoptosis. However, instead of being pathogenic, parasite-induced apoptosis may facilitate host survival. Consequently, it is of utmost importance to decipher and understand the process and the role of apoptosis induced or controlled by parasites in humans. Despite this, few studies provide definitive knowledge of parasite-induced host-cell apoptosis. Here, the focus is on a consideration of host-cell apoptosis as either a pathogenic feature or as a factor enabling parasite survival and development. Cell death by apoptotic-like mechanisms could be described as a ride to death with a return ticket, as initiation of the pathway may be reversed, with the potential that it could be manipulated for therapeutic purposes. The management of host-cell apoptosis could thus be an adjunctive factor for parasitic disease treatment. Evidence that the apoptotic process could be reversed by anti-apoptotic drugs has recently been obtained, leading to the possibility of host-cell rescue after injury. An important issue will be to predict the beneficial or deleterious effects of controlling human cell death by apoptotic-like mechanisms during parasitic diseases. PMID:21083888

  12. Rhodamine B induces long nucleoplasmic bridges and other nuclear anomalies in Allium cepa root tip cells.

    PubMed

    Tan, Dehong; Bai, Bing; Jiang, Donghua; Shi, Lin; Cheng, Shunchang; Tao, Dongbing; Ji, Shujuan

    2014-03-01

    The cytogenetic toxicity of rhodamine B on root tip cells of Allium cepa was investigated. A. cepa were cultured in water (negative control), 10 ppm methyl methanesulfonate (positive control), and three concentrations of rhodamine B (200, 100, and 50 ppm) for 7 days. Rhodamine B inhibited mitotic activity; increased nuclear anomalies, including micronuclei, nuclear buds, and bridged nuclei; and induced oxidative stress in A. cepa root tissues. Furthermore, a substantial amount of long nucleoplasmic bridges were entangled together, and some nuclei were simultaneously linked to several other nuclei and to nuclear buds with nucleoplasmic bridges in rhodamine B-treated cells. In conclusion, rhodamine B induced cytogenetic effects in A. cepa root tip cells, which suggests that the A. cepa root is an ideal model system for detecting cellular interactions. PMID:24234815

  13. Unc93b Induces Apoptotic Cell Death and Is Cleaved by Host and Enteroviral Proteases

    PubMed Central

    Harris, Katharine G.; Coyne, Carolyn B.

    2015-01-01

    Unc93b is an endoplasmic reticulum (ER)-resident transmembrane protein that serves to bind and traffic toll-like receptors (TLRs) from the ER to their appropriate subcellular locations for ligand sensing. Because of its role in TLR trafficking, Unc93b is necessary for an effective innate immune response to coxsackievirus B3 (CVB), a positive-sense single stranded RNA virus belonging to the enterovirus family. Here, we show that Unc93b is cleaved by a CVB-encoded cysteine protease (3Cpro) during viral replication. Further, we define a role for Unc93b in the induction of apoptotic cell death and show that expression of wild-type Unc93b, but not a mutant incapable of binding TLRs or exiting the ER (H412R), induces apoptosis. Furthermore, we show that cellular caspases activated during apoptosis directly cleave Unc93b. Interestingly, we show that the 3Cpro- and caspase-mediated cleavage of Unc93b both occur within ten amino acids in the distal N-terminus of Unc93b. Mechanistically, neither caspase-mediated nor 3Cpro-mediated cleavage of Unc93b altered its trafficking function, inhibited its role in facilitating TLR3 or TLR8 signaling, or altered its apoptosis-inducing effects. Taken together, our studies show that Unc93b is targeted by both viral- and host cell-specific proteases and identify a function of Unc93b in the induction of apoptotic cell death. PMID:26509685

  14. A novel polyamine allosteric site of SpeG from Vibrio cholerae is revealed by Its dodecameric structure

    DOE PAGESBeta

    Filippova, Ekaterina V.; Kuhn, Misty L.; Osipiuk, Jerzy; Kiryukhina, Olga; Joachimiak, Andrzej; Ballicora, Miguel A.; Anderson, Wayne F.

    2015-03-01

    Spermidine N-acetyltransferase, encoded by the gene speG, catalyzes the initial step in the degradation of polyamines and is a critical enzyme for determining the polyamine concentrations in bacteria. In Escherichia coli, studies have shown that SpeG is the enzyme responsible for acetylating spermidine under stress conditions and for preventing spermidine toxicity. Not all bacteria contain speG, and many bacterial pathogens have developed strategies to either acquire or silence it for pathogenesis. Here, we present thorough kinetic analyses combined with structural characterization of the VCA0947 SpeG enzyme from the important human pathogen Vibrio cholerae. Our studies revealed the unexpected presence ofmore »a previously unknown allosteric site and an unusual dodecameric structure for a member of the Gcn5-related N-acetyltransferase superfamily. We show that SpeG forms dodecamers in solution and in crystals and describe its three-dimensional structure in several ligand-free and liganded structures. Importantly, these structural data define the first view of a polyamine bound in an allosteric site of an N-acetyltransferase. Kinetic characterization of SpeG from V. cholerae showed that it acetylates spermidine and spermine. The behavior of this enzyme is complex and exhibits sigmoidal curves and substrate inhibition. We performed a detailed non-linear regression kinetic analysis to simultaneously fit families of substrate saturation curves to uncover a simple kinetic mechanism that explains the apparent complexity of this enzyme. Our results provide a fundamental understanding of the bacterial SpeG enzyme, which will be key toward understanding the regulation of polyamine levels in bacteria during pathogenesis.« less

  15. Large-N Over the Source Physics Experiment (SPE) Phase I and Phase II Test Beds

    NASA Astrophysics Data System (ADS)

    Snelson, C. M.; Carmichael, J. D.; Mellors, R. J.; Abbott, R. E.

    2014-12-01

    One of the current challenges in the field of monitoring and verification is source discrimination of low-yield nuclear explosions from background seismicity, both natural and anthropogenic. Work is underway at the Nevada National Security Site to conduct a series of chemical explosion experiments using a multi-institutional, multi-disciplinary approach. The goal of this series of experiments, called the Source Physics Experiments (SPE), is to refine the understanding of the effect of earth structures on source phenomenology and energy partitioning in the source region, the transition of seismic energy from the near field to the far field, and the development of S waves observed in the far field. To fully explore these problems, the SPE series includes tests in both hard and soft rock geologic environments. The project comprises a number of activities, which range from characterizing the shallow subsurface to acquiring new explosion data from both the near field (<100 m) and the far field (>100 m). SPE includes a series of planned explosions (with different yields and depths of burials), which are conducted in the same hole and monitored by a diverse set of sensors recording characteristics of the explosions, ground-shock, seismo-acoustic energy propagation. This presentation focuses on imaging the full 3D wavefield over hard rock and soft rock test beds using a large number of seismic sensors. This overview presents statistical analyses of optimal sensor layout required to estimate wavefield discriminants and the planned deployment for the upcoming experiments. This work was conducted under Contract No. DE-AC52-06NA25946 with the U.S. Department of Energy. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  16. Moment Tensor Descriptions for Simulated Explosions of the Source Physics Experiment (SPE)

    NASA Astrophysics Data System (ADS)

    Yang, X.; Rougier, E.; Knight, E. E.; Patton, H. J.

    2014-12-01

    In this research we seek to understand damage mechanisms governing the behavior of geo-materials in the explosion source region, and the role they play in seismic-wave generation. Numerical modeling tools can be used to describe these mechanisms through the development and implementation of appropriate material models. Researchers at Los Alamos National Laboratory (LANL) have been working on a novel continuum-based-viscoplastic strain-rate-dependent fracture material model, AZ_Frac, in an effort to improve the description of these damage sources. AZ_Frac has the ability to describe continuum fracture processes, and at the same time, to handle pre-existing anisotropic material characteristics. The introduction of fractures within the material generates further anisotropic behavior that is also accounted for within the model. The material model has been calibrated to a granitic medium and has been applied in a number of modeling efforts under the SPE project. In our modeling, we use a 2D, axisymmetric layered earth model of the SPE site consisting of a weathered layer on top of a half-space. We couple the hydrodynamic simulation code with a seismic simulation code and propagate the signals to distances of up to 2 km. The signals are inverted for time-dependent moment tensors using a modified inversion scheme that accounts for multiple sources at different depths. The inversion scheme is evaluated for its resolving power to determine a centroid depth and a moment tensor description of the damage source. The capabilities of the inversion method to retrieve such information from waveforms recorded on three SPE tests conducted to date are also being assessed.

  17. Geologic Assessment of the Damage Zone from the Second Test at Source Physics Experiment-Nevada (SPE-N)

    SciTech Connect

    Townsend, M. J.; Huckins-Gang, H. E.; Prothro, L. B.; Reed, D. N.

    2012-12-01

    The National Center for Nuclear Security, established by the U.S. Department of Energy, National Nuclear Security Administration (NNSA), is conducting a series of explosive tests at the Nevada National Security Site that are designed to increase the understanding of certain basic physical phenomena associated with underground explosions. These tests will aid in developing technologies that might be used to detect underground nuclear explosions in support of verification activities for the Comprehensive Nuclear-Test-Ban Treaty. The initial project is a series of explosive tests, known collectively as the Source Physics Experiment-Nevada (SPE-N), being conducted in granitic rocks. The SPE-N test series is designed to study the generation and propagation of seismic waves. The results will help advance the seismic monitoring capability of the United States by improving the predictive capability of physics-based modeling of explosive phenomena. The first SPE N (SPE-N-1) test was conducted in May 2011, using 100 kg of explosives at the depth of 54.9 m in the U 15n source hole. SPE-N-2 was conducted in October 2011, using 1,000 kg of explosives at the depth of 45.7 m in the same source hole. The SPE-N-3 test was conducted in the same source hole in July 2012, using the same amount and type of explosive as for SPE-N-2, and at the same depth as SPE-N-2, within the damage zone created by the SPE-N-2 explosion to investigate damage effects on seismic wave propagation. Following the SPE-N-2 shot and prior to the SPE-N-3 shot, the core hole U-15n#10 was drilled at an angle from the surface to intercept the SPE-N-2 shot point location to obtain information necessary to characterize the damage zone. The objective was to determine the position of the damage zone near the shot point, at least on the northeast, where the core hole penetrated it, and obtain information on the properties of the damaged medium. Geologic characterization of the post-SPE-N-2 core hole included geophysical logging, a directional survey, and geologic description of the core to document visual evidence of damage. Selected core samples were provided to Sandia National Laboratories (SNL) for measurement of physical and mechanical properties. A video was also run in the source hole after it was cleaned out. A significant natural fault zone was encountered in the angle core hole between 5.7 and 7.5 m from the shot point. However, several of the fractures observed in the core hole are interpreted as having been caused by the explosion. The fractures are characterized by a “fresh,” mechanically broken look, with uncoated and very irregular surfaces. They tend to terminate against natural fractures and have orientations that differ from the previously defined natural fracture sets; they are common starting at about 5.4 m from the shot point. Within about 3.3 m of the shot point to the end of the recovered core at 1.6 m from the shot point, some of the core samples are softer and lighter in color, but do not appear to be weathered. It is thought this could be indicative of the presence of distributed microfracturing.

  18. Spontaneous apoptosis in human thymocytes.

    PubMed Central

    Tiso, M.; Gangemi, R.; Bargellesi Severi, A.; Pizzolitto, S.; Fabbi, M.; Risso, A.

    1995-01-01

    Apoptosis seems to be involved in different stages of immune cell development. In particular, experimental evidence suggests that it is a major form of cell death in the thymus. The present analysis of human thymocytes reveals that a fraction of these cells, cultured in vitro, undergoes spontaneous apoptosis. This observation is based both on molecular (DNA fragmentation) and morphological (electron microscopic) investigations of the cells. The apoptotic thymocytes are CD3- or CD3lo, CD4lo, and CD8lo and do not express Bcl-2 protein. Furthermore, thymocytes die by apoptosis when exposed to pharmacological stimuli, such as tumor necrosis factor-alpha, dexamethasone, ATP, or Ca++ ionophore. Thus the apoptotic machinery in thymocytes can be triggered by an imbalance in growth factors in the in vitro culture media and can be modulated by various biochemical signals. The process of spontaneous apoptosis is independent of mRNA or protein synthesis, as actinomycin D and cycloheximide fail to inhibit this phenomenon. Furthermore, apoptosis seems to require active oxidative phosphorylation, as it is prevented by incubation of the cells with inhibitors of the respiratory chain. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 6 Figure 7 Figure 8 PMID:7639336

  19. cDNA cloning, expression, and mutagenesis of a PR-10 protein SPE-16 from the seeds of Pachyrrhizus erosus.

    PubMed

    Wu, Fang; Yan, Ming; Li, Yikun; Chang, Shaojie; Song, Xiaomin; Zhou, Zhaocai; Gong, Weimin

    2003-12-19

    SPE-16 is a new 16kDa protein that has been purified from the seeds of Pachyrrhizus erosus. It's N-terminal amino acid sequence shows significant sequence homology to pathogenesis-related class 10 proteins. cDNA encoding 150 amino acids was cloned by RT-PCR and the gene sequence proved SPE-16 to be a new member of PR-10 family. The cDNA was cloned into pET15b plasmid and expressed in Escherichia coli. The bacterially expressed SPE-16 also demonstrated ribonuclease-like activity in vitro. Site-directed mutation of three conserved amino acids E95A, E147A, Y150A, and a P-loop truncated form were constructed and their different effects on ribonuclease activities were observed. SPE-16 is also able to bind the fluorescent probe 8-anilino-1-naphthalenesulfonate (ANS) in the native state. The ANS anion is a much-utilized "hydrophobic probe" for proteins. This binding activity indicated another biological function of SPE-16. PMID:14680830

  20. Bovine lactoferricin causes apoptosis in Jurkat T-leukemia cells by sequential permeabilization of the cell membrane and targeting of mitochondria

    SciTech Connect

    Mader, Jamie S.; Richardson, Angela; Salsman, Jayme; Top, Deniz; Antueno, Roberto de; Duncan, Roy; Hoskin, David W. . E-mail: d.w.hoskin@dal.ca

    2007-07-15

    Bovine lactoferricin (LfcinB) is a cationic antimicrobial peptide that kills Jurkat T-leukemia cells by the mitochondrial pathway of apoptosis. However, the process by which LfcinB triggers mitochondria-dependent apoptosis is not well understood. Here, we show that LfcinB-induced apoptosis in Jurkat T-leukemia cells was preceded by LfcinB binding to, and progressive permeabilization of the cell membrane. Colloidal gold electron microscopy revealed that LfcinB entered the cytoplasm of Jurkat T-leukemia cells prior to the onset of mitochondrial depolarization. LfcinB was not internalized by endocytosis because endocytosis inhibitors did not prevent LfcinB-induced cytotoxicity. Furthermore, intracellular delivery of LfcinB via fusogenic liposomes caused the death of Jurkat T-leukemia cells, as well as normal human fibroblasts. Collectively, these findings suggest that LfcinB caused damage to the cell membrane that allowed LfcinB to enter the cytoplasm of Jurkat T-leukemia cells and mediate cytotoxicity. In addition, confocal microscopy showed that intracellular LfcinB co-localized with mitochondria in Jurkat T-leukemia cells, while flow cytometry and colloidal gold electron microscopy showed that LfcinB rapidly associated with purified mitochondria. Furthermore, purified mitochondria treated with LfcinB rapidly lost transmembrane potential and released cytochrome c. We conclude that LfcinB-induced apoptosis in Jurkat T-leukemia cells resulted from cell membrane damage and the subsequent disruption of mitochondrial membranes by internalized LfcinB.

  1. Apoptosis in health and disease.

    PubMed

    Singh, N; Anand, S

    1995-04-01

    Two distinct forms of cell death are known, necrosis which results from physical or chemical insult and apoptosis or programmed cell death results from programming within the cell for self destruction in response to internal and external stimuli. Apoptosis is a genetically governed process of cell death occurring in development and maintenance of multicellular organisms. It occurs to get rid of individual cells that become unwanted for various reasons or that present a threat to the organism. It is accompanied by distinct morphological changes. DNA fragmentation in most cases, and appears to be caused by the activities of specific genes. Its defective regulation may play a part in the aetiology of cancer, AIDS, autoimmune and degenerative diseases. Apoptosis offers potential for prevention and therapeutic modulation of these disorders. PMID:7649613

  2. The mechanism of PDT-induced apoptosis

    NASA Astrophysics Data System (ADS)

    Cai, Xiongwei; Liu, Timon C.; Ding, Xin-Min; Gu, Ying; Liu, Fan-Guang; Liu, Song-Hao

    2003-12-01

    Photodynamic therapy (PDT) can induce apoptosis in many cancer cells in vitro and in tumors in vivo. Cells become more oxidation with PDT, and maintain differentiation and proliferation, go apoptosis and necrosis with the increase of reactive oxygen species (ROS) concentration. ROS can induce apoptosis through mitochondria by inhibiting respiration chain or oxidative phosphorylation or damaging mitochondrial membrane. ROS can initiate apoptosis through endoplamic reticulum(ER) by opening Ca2+ channel or starting unfold protein response (UPR). ROS can also induce apoptosis through Golgi by producing ganglioside GD3 by use of ceramide, which induces apoptosis by activating caspase-3, JNK and p38 MAPK. It can also induce apoptosis by activating Bip (mitochondria-dependant) or preocaspase-12 (mitochondria- independent) or inhibiting protein synthesizing. There are so complicated cross-talking among different signal pathways or organnells that we think PDT-induced apoptosis is mediated by multiplex pathways and excessive levels in a refined network.

  3. Recent improvements in SPE3D: a VR-based surgery planning environment

    NASA Astrophysics Data System (ADS)

    Witkowski, Marcin; Sitnik, Robert; Verdonschot, Nico

    2014-02-01

    SPE3D is a surgery planning environment developed within TLEMsafe project [1] (funded by the European Commission FP7). It enables the operator to plan a surgical procedure on the customized musculoskeletal (MS) model of the patient's lower limbs, send the modified model to the biomechanical analysis module, and export the scenario's parameters to the surgical navigation system. The personalized patient-specific three-dimensional (3-D) MS model is registered with 3-D MRI dataset of lower limbs and the two modalities may be visualized simultaneously. Apart from main planes, any arbitrary MRI cross-section can be rendered on the 3-D MS model in real time. The interface provides tools for: bone cutting, manipulating and removal, repositioning muscle insertion points, modifying muscle force, removing muscles and placing implants stored in the implant library. SPE3D supports stereoscopic viewing as well as natural inspection/manipulation with use of haptic devices. Alternatively, it may be controlled with use of a standard computer keyboard, mouse and 2D display or a touch screen (e.g. in an operating room). The interface may be utilized in two main fields. Experienced surgeons may use it to simulate their operative plans and prepare input data for a surgical navigation system while student or novice surgeons can use it for training.

  4. IRTF/SPeX Observations of the Unusual Kepler Light Curve System KIC8462852

    NASA Astrophysics Data System (ADS)

    Lisse, C. M.; Sitko, M. L.; Marengo, M.

    2015-12-01

    We have utilized the NASA/IRTF 3 m SpeX instrument's high-resolution spectral mode to observe and characterize the near-infrared flux emanating from the unusual Kepler light curve system KIC 8462852. By comparing the resulting 0.8-4.2 ?m spectrum to a mesh of model photospheric spectra, the 6 emission line analyses of the Rayner et al. catalog, and the 25 system collections of debris disks we have observed to date using SpeX under the Near InfraRed Debris disk Survey, we have been able to additionally characterize the system. Within the errors of our measurements, this star looks like a normal solar abundance main-sequence F1V to F3V dwarf star without any obvious traces of significant circumstellar dust or gas. Using Connelley & Greene's emission measures, we also see no evidence of significant ongoing accretion onto the star nor any stellar outflow away from it. Our results are inconsistent with large amounts of static close-in obscuring material or the unusual behavior of a YSO system, but are consistent with the favored episodic giant comet models of a Gyr old stellar system favored by Boyajian et al. We speculate that KIC 8462852, like the ˜1.4 Gyr old F2V system ? Corvi, is undergoing a late heavy bombardment, but is only in its very early stages.

  5. Design and test status for life support applications of SPE oxygen generation systems. [Solid Polymer Electrolyte

    NASA Technical Reports Server (NTRS)

    Titterington, W. A.; Erickson, A. C.

    1975-01-01

    An advanced six-man rated oxygen generation system has been fabricated and tested as part of a NASA/JSC technology development program for a long lived, manned spacecraft life support system. Details of the design and tests results are presented. The system is based on the Solid Polymer Electrolyte (SPE) water electrolysis technology and its nominal operating conditions are 2760 kN/sq m (400 psia) and 355 K (180 F) with an electrolysis module current density capability up to 350 mA/sq cm (326 ASF). The system is centered on a 13-cell SPE water electrolysis module having a single cell active area of 214 sq cm (33 sq in) and it incorporates instrumentation and controls for single pushbutton automatic startup/shutdown, component fault detection and isolation, and self-contained sensors and controls for automatic safe emergency shutdown. The system has been tested in both the orbital cyclic and continuous mode of operation. Various parametric tests have been completed to define the system capability for potential application in spacecraft environmental systems.

  6. Resolution of bronchial hyperresponsiveness and pulmonary inflammation is associated with IL-3 and tissue leukocyte apoptosis.

    PubMed

    Lloyd, C M; Gonzalo, J A; Nguyen, T; Delaney, T; Tian, J; Oettgen, H; Coyle, A J; Gutierrez-Ramos, J C

    2001-02-01

    We have used two models of murine pulmonary inflammation to investigate the signals responsible for the resolution of bronchial hyperresponsiveness (BHR). Both protocols involved two sensitizations with OVA followed by serial aerosolized challenge with OVA. We determined that administration of the second sensitization by aerosol (model A) was associated with a transient response, whereas administration by the i.p. route (model B) induced a sustained response, in the form of BHR and eosinophilia. This difference in kinetics was due solely to the route of the second Ag administration and was not associated with Ag dose or adjuvant. Differences in kinetics of lung eosinophilia/BHR were shown to be independent of IgE levels and IL-4 or IL-5. However, IL-3 levels in model A closely correlated with the rate of leukocyte clearance by apoptosis and were observed concomitant with a decline in BHR. Blockage of IL-3 in model B increased leukocyte apoptosis but reduced tissue eosinophilia and BHR. The use of mouse models in which a single different administration of allergen is associated with a failure/success to resolve inflammation and BHR by 72 h postchallenge indicates a link between IL-3 production, leukocyte apoptosis, and BHR responses. PMID:11160253

  7. Brevenal inhibits pacific ciguatoxin-1B-induced neurosecretion from bovine chromaffin cells.

    PubMed

    Mattei, César; Wen, Peter J; Nguyen-Huu, Truong D; Alvarez, Martha; Benoit, Evelyne; Bourdelais, Andrea J; Lewis, Richard J; Baden, Daniel G; Molgó, Jordi; Meunier, Frédéric A

    2008-01-01

    Ciguatoxins and brevetoxins are neurotoxic cyclic polyether compounds produced by dinoflagellates, which are responsible for ciguatera and neurotoxic shellfish poisoning (NSP) respectively. Recently, brevenal, a natural compound was found to specifically inhibit brevetoxin action and to have a beneficial effect in NSP. Considering that brevetoxin and ciguatoxin specifically activate voltage-sensitive Na+ channels through the same binding site, brevenal has therefore a good potential for the treatment of ciguatera. Pacific ciguatoxin-1B (P-CTX-1B) activates voltage-sensitive Na+ channels and promotes an increase in neurotransmitter release believed to underpin the symptoms associated with ciguatera. However, the mechanism through which slow Na+ influx promotes neurosecretion is not fully understood. In the present study, we used chromaffin cells as a model to reconstitute the sequence of events culminating in ciguatoxin-evoked neurosecretion. We show that P-CTX-1B induces a tetrodotoxin-sensitive rise in intracellular Na+, closely followed by an increase in cytosolic Ca2+ responsible for promoting SNARE-dependent catecholamine secretion. Our results reveal that brevenal and beta-naphtoyl-brevetoxin prevent P-CTX-1B secretagogue activity without affecting nicotine or barium-induced catecholamine secretion. Brevenal is therefore a potent inhibitor of ciguatoxin-induced neurotoxic effect and a potential treatment for ciguatera. PMID:18941627

  8. Identification of an epithelial cell receptor responsible for Clostridium difficile TcdB-induced cytotoxicity

    PubMed Central

    LaFrance, Michelle E.; Farrow, Melissa A.; Chandrasekaran, Ramyavardhanee; Sheng, Jinsong; Rubin, Donald H.; Lacy, D. Borden

    2015-01-01

    Clostridium difficile is the leading cause of hospital-acquired diarrhea in the United States. The two main virulence factors of C. difficile are the large toxins, TcdA and TcdB, which enter colonic epithelial cells and cause fluid secretion, inflammation, and cell death. Using a gene-trap insertional mutagenesis screen, we identified poliovirus receptor-like 3 (PVRL3) as a cellular factor necessary for TcdB-mediated cytotoxicity. Disruption of PVRL3 expression by gene-trap mutagenesis, shRNA, or CRISPR/Cas9 mutagenesis resulted in resistance of cells to TcdB. Complementation of the gene-trap or CRISPR mutants with PVRL3 resulted in restoration of TcdB-mediated cell death. Purified PVRL3 ectodomain bound to TcdB by pull-down. Pretreatment of cells with a monoclonal antibody against PVRL3 or prebinding TcdB to PVRL3 ectodomain also inhibited cytotoxicity in cell culture. The receptor is highly expressed on the surface epithelium of the human colon and was observed to colocalize with TcdB in both an explant model and in tissue from a patient with pseudomembranous colitis. These data suggest PVRL3 is a physiologically relevant binding partner that can serve as a target for the prevention of TcdB-induced cytotoxicity in C. difficile infection. PMID:26038560

  9. APOPTOSIS IN WHOLE MOUSE OVARIES

    EPA Science Inventory

    Apoptosis in Whole Mouse Ovaries
    Robert M. Zucker Susan C. Jeffay and Sally D. Perreault
    Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, 27711.

  10. This paper was prepared for presentation at the SPE/DOE Thirteenth Symposium on Improved Oil Recovery held in Tulsa, Oklahoma, 1317 April 2002.

    E-print Network

    Patzek, Tadeusz W.

    This paper was prepared for presentation at the SPE/DOE Thirteenth Symposium on Improved Oil Recovery held in Tulsa, Oklahoma, 13­17 April 2002. This paper was selected for presentation by an SPE(s). Contents of the paper, as presented, have not been reviewed by the Society of Petroleum Engineers

  11. This paper was prepared for presentation at the SPE Annual Technical Conference and Exhibition held in New Orleans, 30 September 3 October 2001.

    E-print Network

    Patzek, Tadeusz W.

    This paper was prepared for presentation at the SPE Annual Technical Conference and Exhibition held in New Orleans, 30 September ­ 3 October 2001. This paper was selected for presentation by an SPE Program of the paper, as presented, have not been reviewed by the Society of Petroleum Engineers and are subject

  12. New Model to Predict Formation Damage due to Sulfur Deposition in Sour M.A. Mahmoud and A.A. Al-Majed, KFUPM, all SPE

    E-print Network

    Al-Majed, Abdulaziz Abdullah

    SPE 149535 New Model to Predict Formation Damage due to Sulfur Deposition in Sour Gas Wells M of SPE copyright. Abstract Elemental sulfur (S8) is often present in considerable amounts in sour gas in the reservoir, the reduction in reservoir pressure below a critical value will cause the elemental sulfur

  13. UV-B–Induced DNA Damage and Repair in the Mouse Lens

    PubMed Central

    Mesa, Rosana; Bassnett, Steven

    2013-01-01

    Purpose. Epidemiologic studies have linked UV-B exposure to development of cortical cataracts, but the underlying molecular mechanism(s) is unresolved. Here, we used a mouse model to examine the nature and distribution of DNA photolesions produced by ocular UV-B irradiation. Methods. Anesthetized mice, eye globes, or isolated lenses were exposed to UV-B. Antibodies specific for 6-4 photoproducts (6-4 PPs) or cyclobutane pyrimidine dimers (CPDs) were used to visualize DNA adducts. Results. Illumination of intact globes with UV-B–induced 6-4 PP and CPD formation in cells of the cornea, anterior iris, and central lens epithelium. Photolesions were not detected in retina or lens cells situated in the shadow of the iris. Photolesions in lens epithelial cells were produced with radiant exposures significantly below the minimal erythemal dose. Lens epithelial cells rapidly repaired 6-4 PPs, but CPD levels did not markedly diminish, even over extended postirradiation recovery periods in vitro or in vivo. The repair of 6-4 PPs did not depend on the proliferative activity of the epithelial cells, since the repair rate in the mitotically-active germinative zone (GZ) was indistinguishable from that of quiescent cells in the central epithelium. Conclusions. Even relatively modest exposures to UV-B produced 6-4 PP and CPD photolesions in lens epithelial cells. Cyclobutane pyrimidine dimer lesions were particularly prevalent and were repaired slowly if at all. Studies on sun-exposed skin have established a causal connection between photolesions and so-called UV-signature mutations. If similar mechanisms apply in the lens, it suggests that somatic mutations in lens epithelial cells may contribute to the development of cortical cataracts. PMID:24022010

  14. Isorhamnetin Protects Human Keratinocytes against Ultraviolet B-Induced Cell Damage

    PubMed Central

    Han, Xia; Piao, Mei Jing; Kim, Ki Cheon; Madduma Hewage, Susara Ruwan Kumara; Yoo, Eun Sook; Koh, Young Sang; Kang, Hee Kyoung; Shin, Jennifer H; Park, Yeunsoo; Yoo, Suk Jae; Chae, Sungwook; Hyun, Jin Won

    2015-01-01

    Isorhamnetin (3-methylquercetin) is a flavonoid derived from the fruits of certain medicinal plants. This study investigated the photoprotective properties of isorhamnetin against cell damage and apoptosis resulting from excessive ultraviolet (UV) B exposure in human HaCaT keratinocytes. Isorhamnetin eliminated UVB-induced intracellular reactive oxygen species (ROS) and attenuated the oxidative modification of DNA, lipids, and proteins in response to UVB radiation. Moreover, isorhamnetin repressed UVB-facilitated programmed cell death in the keratinocytes, as evidenced by a reduction in apoptotic body formation, and nuclear fragmentation. Additionally, isorhamnetin suppressed the ability of UVB light to trigger mitochondrial dysfunction. Taken together, these results indicate that isorhamnetin has the potential to protect human keratinocytes against UVB-induced cell damage and death. PMID:26157553

  15. Isorhamnetin Protects Human Keratinocytes against Ultraviolet B-Induced Cell Damage.

    PubMed

    Han, Xia; Piao, Mei Jing; Kim, Ki Cheon; Madduma Hewage, Susara Ruwan Kumara; Yoo, Eun Sook; Koh, Young Sang; Kang, Hee Kyoung; Shin, Jennifer H; Park, Yeunsoo; Yoo, Suk Jae; Chae, Sungwook; Hyun, Jin Won

    2015-07-01

    Isorhamnetin (3-methylquercetin) is a flavonoid derived from the fruits of certain medicinal plants. This study investigated the photoprotective properties of isorhamnetin against cell damage and apoptosis resulting from excessive ultraviolet (UV) B exposure in human HaCaT keratinocytes. Isorhamnetin eliminated UVB-induced intracellular reactive oxygen species (ROS) and attenuated the oxidative modification of DNA, lipids, and proteins in response to UVB radiation. Moreover, isorhamnetin repressed UVB-facilitated programmed cell death in the keratinocytes, as evidenced by a reduction in apoptotic body formation, and nuclear fragmentation. Additionally, isorhamnetin suppressed the ability of UVB light to trigger mitochondrial dysfunction. Taken together, these results indicate that isorhamnetin has the potential to protect human keratinocytes against UVB-induced cell damage and death. PMID:26157553

  16. Excess NF-?B induces ectopic odontogenesis in embryonic incisor epithelium.

    PubMed

    Blackburn, J; Kawasaki, K; Porntaveetus, T; Kawasaki, M; Otsuka-Tanaka, Y; Miake, Y; Ota, M S; Watanabe, M; Hishinuma, M; Nomoto, T; Oommen, S; Ghafoor, S; Harada, F; Nozawa-Inoue, K; Maeda, T; Peterková, R; Lesot, H; Inoue, J; Akiyama, T; Schmidt-Ullrich, R; Liu, B; Hu, Y; Page, A; Ramírez, Á; Sharpe, P T; Ohazama, A

    2015-01-01

    Nuclear factor kappa B (NF-?B) signaling plays critical roles in many physiological and pathological processes, including regulating organogenesis. Down-regulation of NF-?B signaling during development results in hypohidrotic ectodermal dysplasia. The roles of NF-?B signaling in tooth development, however, are not fully understood. We examined mice overexpressing IKK?, an essential component of the NF-?B pathway, under keratin 5 promoter (K5-Ikk?). K5-Ikk? mice showed supernumerary incisors whose formation was accompanied by up-regulation of canonical Wnt signaling. Apoptosis that is normally observed in wild-type incisor epithelium was reduced in K5-Ikk? mice. The supernumerary incisors in K5-Ikk? mice were found to phenocopy extra incisors in mice with mutations of Wnt inhibitor, Wise. Excess NF-?B activity thus induces an ectopic odontogenesis program that is usually suppressed under physiological conditions. PMID:25376721

  17. Suppressive effects of ascorbate derivatives on ultraviolet-B-induced injury in HaCaT human keratinocytes.

    PubMed

    Yasuda, Shin; Tada, Mikiro; Yamada, Koji; Takahata, Kyoya

    2004-01-01

    The aging of skin, including sunburning, is caused by ultraviolet (UV) irradiation. Here, we examined the inhibitory effect of ascorbic acid (AsA) and its derivatives AsA 2-phosphate (AA-2P) and AsA 2-glucoside (AA-2G) on UV-B- induced cytotoxicity in HaCaT keratinocytes. Results show that cell viability significantly decreased when exposed to UV-B at 0.1-0.4 J/cm2 in a dose-dependent manner. In this study, AsA could not inhibit cytotoxicity, but AA-2P and AA-2G was able to cancel the harmful effect of UV-B when treated at high levels of 0.5-5 mM. These results indicate that the masking of the C-2 OH group may be an effective modification for AsA to inhibit UV-B-induced cytotoxicity in human keratinocytes. PMID:15311965

  18. SPE 173235-MS revised (expanded for submission to SPEJ) Identifiability of Location and Magnitude of Flow Barriers in Slightly

    E-print Network

    Van den Hof, Paul

    SPE 173235-MS revised (expanded for submission to SPEJ) Identifiability of Location and Magnitude the identifiability, from noisy production data, of the location and the magnitude of a low-permeable barrier-analytical results show that it is possible to identify the location and the magnitude of the permeability

  19. Copyright 2006, Society of Petroleum Engineers This paper was prepared for presentation at the 2006 SPE Annual Technical Conference and

    E-print Network

    Torres-Verdín, Carlos

    SPE Annual Technical Conference and Exhibition held in San Antonio, Texas, U.S.A., 24­27 September of pressure and concentration. Simulations described in this paper consider the process of oil-base mud-filtrate invasion into reservoirs containing mixtures of connate water and oil. Subsequently, we simulate formation

  20. Copyright 2004, Society of Petroleum Engineers Inc. This paper was prepared for presentation at the SPE Annual Technical Conference and

    E-print Network

    Torres-Verdín, Carlos

    of the process of mud-filtrate invasion yield 2D cross-sections of water saturation, salt concentration affected by both the relative proportion of lithology and the invasion of mud filtrate. Water saturation at the SPE Annual Technical Conference and Exhibition held in Houston, Texas, U.S.A., 26­29 September 2004

  1. Copyright 2007, Society of Petroleum Engineers This paper was prepared for presentation at the 2007 SPE Annual Technical Conference and

    E-print Network

    Torres-Verdín, Carlos

    of where and by whom the paper was presented. Write Librarian, SPE, P.O. Box 833836, Richardson, Texas 75083-3836 U.S.A., fax 01-972-952-9435. Abstract We quantify the influence of oil-base mud-filtrate consists of adding water and surfactant to a multi-component OBM invading a formation saturated

  2. Near-Infrared Spectral Monitoring of Triton with IRTF/SpeX II: Spatial Distribution and Evolution of Ices

    E-print Network

    Young, Leslie A.

    Near-Infrared Spectral Monitoring of Triton with IRTF/SpeX II: Spatial Distribution and Evolution and evolution of Triton's ices Manuscript pages: 51 Figures: 11 Tables: 5 #12;­ 2 ­ ABSTRACT This report arises from an ongoing program to monitor Neptune's largest moon Triton spectroscopically in the 0.8 to 2.4 µm

  3. Determination of gadolinium in river water by SPE preconcentration and ICP-MS.

    PubMed

    Hennebrüder, Kristina; Wennrich, Rainer; Mattusch, Jürgen; Stärk, Hans-Joachim; Engewald, Werner

    2004-05-28

    An analytical scheme was developed for the determination of Gd-diethylenetriaminepentaacetate (Gd-DTPA), Gd and the other rare earth elements (REE) in river water by inductively coupled plasma (quadrupole) mass spectrometry (ICP-Q-MS). The preconcentration step was essential, since the limits of detection of this multielemental analytical technique are higher than the trace concentrations of the interesting elements in river water. Solid phase extraction (SPE) with different commercially available complexing agents (Chelex 100, Toyopearl and ethylhexylphosphates) was employed for the preconcentration of REE. The investigations revealed that complex stability (varying in dependence of the pH value) has a strong influence on the degree of the enrichment of Gd-DTPA. Based on acidified water samples (pH<3) a procedure using ethylhexylphosphates was proposed for the preconcentration of Gd and REE from surface water samples. For this purpose C(18)-cartridges loaded with ethylhexylphosphates were used, resulting in an enrichment factor of 40. PMID:18969433

  4. An Overview of the Source Physics Experiment at the Nevada National Security Site (SPE-N)

    SciTech Connect

    Snelson, C. M., Chipman, V. D., White, R. L., Emmitt, R. F., Townsend, M. J., Barker, D., Lee, P.

    2012-07-11

    Understanding the changes in seismic energy as it travels from the near field to the far field is the ultimate goal in monitoring for explosive events of interest. This requires a clear understanding of explosion phenomenology as it relates to seismic, infrasound, and acoustic signals. Although there has been much progress in modeling these phenomena, this has been primarily based in the empirical realm. As a result, the logical next step in advancing the seismic monitoring capability of the United States is to conduct field tests that can expand the predictive capability of the physics-based modeling currently under development. The Source Physics Experiment at the Nevada National Security Site (SPE-N) is the first step in this endeavor to link the empirically based with the physics-based modeling. This is a collaborative project between National Security Technologies (NSTec), Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Sandia National Laboratories (SNL), the Defense Threat Reduction Agency (DTRA), and the Air Force Technical Applications Center (AFTAC). The test series require both the simple and complex cases to fully characterize the problem, which is to understand the transition of seismic energy from the near field to the far field; to understand the development of S-waves in explosives sources; and how anisotropy controls seismic energy transmission and partitioning. The current series is being conducted in a granite body called the Climax Stock. This location was chosen for several reasons, including the fairly homogenous granite; the location of previous nuclear tests in the same rock body; and generally the geology has been well characterized. The simple geology series is planned for 7 shots using conventional explosives in the same shot hole surrounded by Continuous Reflectometry for Radius vs. Time Experiment (CORRTEX), Time of Arrival (TOA), Velocity of Detonation (VOD), down-hole accelerometers, surface accelerometers, infrasound, and a suite of seismic sensors of various frequency bands from the near field to the far field. This allows for the use of a single test bed in the simple geology case instead of multiple tests beds to obtain the same results. The shots are planned at various depths to obtain a Green’s function, scaled-depth of burial data, nominal depth of burial data and damage zone data. SPE1-N was conducted in May 2011 as a 220 lb (100 kg) TNT equivalent calibration shot at a depth of 180 ft (55 m). SPE2-N was conducted in October 2011 as a 2200 lb (1000 kg) TNT equivalent calibration shot at a depth of 150 ft (46 m). SPE3-N was conducted in July 2012 as a 2200 lb (1000 kg) TNT equivalent calibration shot at a depth of 150 ft (46 m) in the damaged zone. Over 400 data channels were recorded for each of these shots and data recovery was about 95% with high signal to noise ratio. Once the simple geology site data has been utilized, a new test bed will be developed in a complex geology site to test these physics based models. Ultimately, the results from this project will provide the next advances in the science of monitoring to enable a physics-based predicative capability.

  5. The Source Physics Experiments (SPE) at the Nevada National Security Site (NNSS): An Overview

    NASA Astrophysics Data System (ADS)

    Snelson, C. M.; Chipman, V.; White, R. L.; Emmitt, R.; Townsend, M.; Barker, D.; Lee, P.

    2012-12-01

    Understanding the changes in seismic energy as it travels from the near field to the far field is the ultimate goal in monitoring for explosive events of interest. This requires a clear understanding of explosion phenomenology as it relates to seismic, infrasound, and acoustic signals. Although there has been much progress in modeling these phenomena, this has been primarily based in the empirical realm. As a result, the logical next step in advancing the seismic monitoring capability of the United States is to conduct field tests that can expand the predictive capability of the physics-based modeling currently under development. The Source Physics Experiment at the Nevada National Security Site (SPE) is the first step in this endeavor to link the empirically based with the physics-based modeling. This is a collaborative project between National Security Technologies (NSTec), Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Sandia National Laboratories (SNL), the Defense Threat Reduction Agency (DTRA), and the Air Force Technical Applications Center (AFTAC). The test series require both the simple and complex cases to fully characterize the problem, which is to understand the transition of seismic energy from the near field to the far field; to understand the development of S-waves in explosives sources; and how anisotropy controls seismic energy transmission and partitioning. The current series is being conducted in a granite body called the Climax Stock. This location was chosen for several reasons, including the fairly homogenous granite; the location of previous nuclear tests in the same rock body; and generally the geology has been well characterized. The simple geology series is planned for 7 shots using conventional explosives in the same shot hole surrounded by Continuous Reflectometry for Radius vs. Time Experiment (CORRTEX), Time of Arrival (TOA), Velocity of Detonation (VOD), down-hole accelerometers, surface accelerometers, infrasound, and a suite of seismic sensors of various frequency bands from the near field to the far field. This allows for the use of a single test bed in the simple geology case instead of multiple tests beds to obtain the same results. The shots are planned at various depths to obtain a Green's function, scaled-depth of burial data, nominal depth of burial data and damage zone data. SPE1 was conducted in May 2011 as a 220 lb (100 kg) TNT equivalent calibration shot at a depth of 180 ft (55 m). SPE2 was conducted in October 2011 as a 2200 lb (1000 kg) TNT equivalent calibration shot at a depth of 150 ft (46 m). SPE3 was conducted in July 2012 as a 2200 lb (1000 kg) TNT equivalent calibration shot at a depth of 150 ft (46 m) in the damaged zone. Over 400 data channels were recorded for each of these shots and data recovery was about 95% with high signal to noise ratio. Once the simple geology site data has been utilized, a new test bed will be developed in a complex geology site to test these physics based models. Ultimately, the results from this project will provide the next advances in the science of monitoring to enable a physics-based predicative capability. This work was done by National Security Technologies, LLC, under Contract No. DE-AC52-06NA25946 with the U.S. Department of Energy. DOE/NV/25946--1584

  6. Application of Nanofiber-packed SPE for Determination of Urinary 1-Hydroxypyrene Level Using HPLC

    PubMed Central

    Ifegwu, Okechukwu Clinton; Anyakora, Chimezie; Chigome, Samuel; Torto, Nelson

    2014-01-01

    It is always desirable to achieve maximum sample clean-up, extraction, and pre-concentration with the minimum possible organic solvent. The miniaturization of sample preparation devices was successfully demonstrated by packing 10 mg of 11 electrospun polymer nanofibers into pipette tip micro column and mini disc cartridges for efficient pre-concentration of 1-hydroxypyrene in urine samples. 1-hydroxypyrene is an extensively studied biomarker of the largest class of chemical carcinogens. Excretory 1-hydroxypyrene was monitored with HPLC/fluorescence detector. Important parameters influencing the percentage recovery such as fiber diameter, fiber packing amount, eluent, fiber packing format, eluent volume, surface area, porosity, and breakthrough parameters were thoroughly studied and optimized. Under optimized condition, there was a near perfect linearity of response in the range of 1–1000 ?g/L with a coefficient of determination (r2) between 0.9992 and 0.9999 and precision (% RSD) ?7.64% (n = 6) for all the analysis (10, 25, and 50 ?g/L). The Limit of detection (LOD) was between 0.022 and 0.15 ?g/L. When compared to the batch studies, both disc packed nanofiber sorbents and pipette tip packed sorbents exhibited evident dominance based on their efficiencies. The experimental results showed comparable absolute recoveries for the mini disc packed fibers (84% for Nylon 6) and micro columns (80% for Nylon 6), although the disc displayed slightly higher recoveries possibly due to the exposure of the analyte to a larger reacting surface. The results also showed highly comparative extraction efficiencies between the nanofibers and conventional C-18 SPE sorbent. Nevertheless, miniaturized SPE devices simplified sample preparation, reducing back pressure, time of the analysis with acceptable reliability, selectivity, detection levels, and environmental friendliness, hence promoting green chemistry. PMID:24812483

  7. Characteristics of four SPE groups with different origins and acceleration processes

    NASA Astrophysics Data System (ADS)

    Kim, R.-S.; Cho, K.-S.; Lee, J.; Bong, S.-C.; Joshi, A. D.; Park, Y.-D.

    2015-09-01

    Solar proton events (SPEs) can be categorized into four groups based on their associations with flare or CME inferred from onset timings as well as acceleration patterns using multienergy observations. In this study, we have investigated whether there are any typical characteristics of associated events and acceleration sites in each group using 42 SPEs from 1997 to 2012. We find the following: (i) if the proton acceleration starts from a lower energy, a SPE has a higher chance to be a strong event (> 5000 particle flux per unit (pfu)) even if its associated flare and/or CME are not so strong. The only difference between the SPEs associated with flare and CME is the location of the acceleration site. (ii) For the former (Group A), the sites are very low (˜ 1 Rs) and close to the western limb, while the latter (Group C) have relatively higher (mean = 6.05 Rs) and wider acceleration sites. (iii) When the proton acceleration starts from the higher energy (Group B), a SPE tends to be a relatively weak event (< 1000 pfu), although its associated CME is relatively stronger than previous groups. (iv) The SPEs categorized by the simultaneous acceleration in whole energy range within 10 min (Group D) tend to show the weakest proton flux (mean = 327 pfu) in spite of strong associated eruptions. Based on those results, we suggest that the different characteristics of SPEs are mainly due to the different conditions of magnetic connectivity and particle density, which are changed with longitude and height as well as their origin.

  8. Pin1 in Neuronal Apoptosis

    PubMed Central

    Becker, Esther B.E.; Bonni, Azad

    2009-01-01

    While the role of the prolyl isomerase Pin1 in dividing cells has long been recognized, Pin1’s function in postmitotic neurons is poorly understood. We have identified a novel mechanism by which Pin1 mediates activation of the mitochondrial cell death machinery specifically in neurons. This perspective presents a sophisticated signaling pathway that triggers neuronal apoptosis upon JNK-mediated phosphorylation of the BH3-only protein BIMEL at serine 65. Pin1 is enriched at the mitochondria in neurons together with BIMEL and components of a neuron-specific JNK signaling complex and functions as a molecular switch that couples the phosphorylation of BIMEL by JNK to apoptosis specifically in neurons. We discuss how these findings relate to our understanding of the development of the nervous system and the pathogenesis of neurologic disorders. PMID:17568190

  9. The Development and Optimization of Techniques for Monitoring Water Quality on-Board Spacecraft Using Colorimetric Solid-Phase Extraction (C-SPE)

    SciTech Connect

    April Hill

    2007-12-01

    The main focus of this dissertation is the design, development, and ground and microgravity validation of methods for monitoring drinking water quality on-board NASA spacecraft using clorimetric-solid phase extraction (C-SPE). The Introduction will overview the need for in-flight water quality analysis and will detail some of the challenges associated with operations in the absence of gravity. The ability of C-SPE methods to meet these challenges will then be discussed, followed by a literature review on existing applications of C-SPE and similar techniques. Finally, a brief discussion of diffuse reflectance spectroscopy theory, which provides a means for analyte identification and quantification in C-SPE analyses, is presented. Following the Introduction, four research chapters are presented as separate manuscripts. Chapter 1 reports the results from microgravity testing of existing C-SPE methods and procedures aboard NASA's C-9 microgravity simulator. Chapter 2 discusses the development of a C-SPE method for determining the total concentration of biocidal silver (i.e., in both dissolved and colloidal forms) in water samples. Chapter 3 presents the first application of the C-SPE technique to the determination of an organic analyte (i.e., formaldehyde). Chapter 4, which is a departure from the main focus of the thesis, details the results of an investigation into the effect of substrate rotation on the kinetics involved in the antigen and labeling steps in sandwich immunoassays. These research chapters are followed by general conclusions and a prospectus section.

  10. Human papillomavirus oncoproteins and apoptosis (Review)

    PubMed Central

    JIANG, PEIYUE; YUE, YING

    2014-01-01

    The aim of this study was to review the literature and identify the association between human papillomavirus (HPV) oncoproteins and apoptosis. HPV-associated apoptosis may be primarily blocked by a number of oncoproteins, including E5, E6 and E7. E5 protein protects cells from tumor necrosis factor-associated apoptosis; the oncoprotein E6 predominantly inhibits apoptosis through the p53 pathway; and oncoprotein E7 is involved in apoptosis activation and inhibition. In addition, HPV oncoproteins are involved in activating or repressing the transcription of E6/E7. In conclusion, HPV oncoproteins, including E5, E6 and E7 protein, may interfere with apoptosis via certain regulatory principles. PMID:24348754

  11. Taxol induces caspase-10-dependent apoptosis.

    PubMed

    Park, Soo-Jung; Wu, Ching-Haung; Gordon, John D; Zhong, Xiaoling; Emami, Armaghan; Safa, Ahmad R

    2004-12-01

    Taxol (paclitaxel) is known to inhibit cell growth and trigger significant apoptosis in various cancer cells. Although taxol induces apoptosis of cancer cells, its exact mechanism of action is not yet known. In this study we investigated death receptors, FAS-associated death domain protein (FADD), the activation of caspases-10 and -8 as well as the downstream caspases, and reactive oxygen species (ROS) in taxol-induced apoptosis in the CCRF-HSB-2 human lymphoblastic leukemia cell line. Pretreating the cells with neutralizing antibodies to Fas, tumor necrosis factor (TNF)-alpha receptor 1, or TNF-related apoptosis-inducing ligand receptors (DR4 and DR5) did not affect taxol-induced apoptosis, but transfection of the cells with a dominant negative FADD plasmid resulted in inhibition of taxol-induced apoptosis, revealing that taxol induces apoptosis independently of these death receptors but dependently on FADD. Furthermore, the drug induced activation of caspases-10, -8, -6, and -3, cleaved Bcl-2, Bid, poly(ADP-ribose) polymerase, and lamin B, and down-regulated cellular levels of FLICE-like inhibitory protein (FLIP) and X-chromosome-linked inhibitor of apoptosis protein (XIAP). However, despite the release of cytochrome c from the mitochondria in taxol-treated cells, caspase-9 was not activated. Inhibitors of caspases-8, -6, or -3 partially inhibited taxol-induced apoptosis, whereas the caspase-10 inhibitor totally abrogated this process. Taxol-induced apoptosis was also associated with decreased mitochondrial membrane potential (Deltapsim) and a significant increase in ROS generation. However, increased ROS production was not directly involved in taxol-triggered apoptosis. Therefore, these results demonstrate for the first time that taxol induces FADD-dependent apoptosis primarily through activation of caspase-10 but independently of death receptors. PMID:15452117

  12. Apoptosis and Molecular Targeting Therapy in Cancer

    PubMed Central

    Hassan, Mohamed; Watari, Hidemichi; AbuAlmaaty, Ali; Ohba, Yusuke; Sakuragi, Noriaki

    2014-01-01

    Apoptosis is the programmed cell death which maintains the healthy survival/death balance in metazoan cells. Defect in apoptosis can cause cancer or autoimmunity, while enhanced apoptosis may cause degenerative diseases. The apoptotic signals contribute into safeguarding the genomic integrity while defective apoptosis may promote carcinogenesis. The apoptotic signals are complicated and they are regulated at several levels. The signals of carcinogenesis modulate the central control points of the apoptotic pathways, including inhibitor of apoptosis (IAP) proteins and FLICE-inhibitory protein (c-FLIP). The tumor cells may use some of several molecular mechanisms to suppress apoptosis and acquire resistance to apoptotic agents, for example, by the expression of antiapoptotic proteins such as Bcl-2 or by the downregulation or mutation of proapoptotic proteins such as BAX. In this review, we provide the main regulatory molecules that govern the main basic mechanisms, extrinsic and intrinsic, of apoptosis in normal cells. We discuss how carcinogenesis could be developed via defective apoptotic pathways or their convergence. We listed some molecules which could be targeted to stimulate apoptosis in different cancers. Together, we briefly discuss the development of some promising cancer treatment strategies which target apoptotic inhibitors including Bcl-2 family proteins, IAPs, and c-FLIP for apoptosis induction. PMID:25013758

  13. [Estrogens determination of livestock dung based on UE-SPE-HPLC/FLD].

    PubMed

    Fu, Yin-Jie; Ling, Wan-Ting; Dong, Chang-Xun; Liu, Juan; Gao, Yan-Zheng; Pan, Yu-Lan

    2013-11-01

    A method for detecting the estrogens estriol, 17beta-estradiol, ethinyl estradiol, and bisphenol A in livestock dung was established by the combination of ultrasonic extraction (UE), solid phase extraction (SPE) purification, and high performance liquid chromatography (HPLC) with fluorescence detector (FLD). The dung samples were extracted with ethyl acetate ultrasonication for 30 min, and purified with C18 solid phase extraction column and related solvents. The test four estrogens in the dung samples were isolated with Inertsil ODS-SP-C18 reversed-phase columns (150 mm x 4.6 mm, 5 microm), and the isolated estrogens were detected with HPLC/FLD. The mobile phase of HPLC for the detection was methanol/acetonitrile/water (volume ratio of 20:30:50), with a flow rate of 0.8 mL x min(-1). The excitation and emission wavelengths of FLD were 280 and 310 nm, respectively, the HPLC column temperature was 40 degrees C, and the injection volume was 20 microL. Good linearity (correlation coefficient greater than 0.9995) was observed by the HPLC/FLD detection when the test four estrogens concentrations were in the range of 1.00-1000.00 microg x L(-1). The detection limit of estriol, bisphenol A, 17beta-estradiol, and ethinyl estradiol was 3.35, 5.01, 2.13, and 1.12 microg x kg(-1), respectively. When the added estrogens concentrations of pig, cow, and chicken dung samples were 0.05, 0.40, and, 1.00 microg x kg(-1), the average recovery of the four estrogens was 75.1%-91.1%, 78.4%-117.0%, and 78.6%-97.8%, respectively, with the relatively standard deviations (RSD, n = 6) all less than 6%. By adopting the established SPE-HPLC/FLD method to detect the estrogens in real pig, cow, and chicken dung samples from parts of the large-scale livestock raising farms in Nanjing of East China, the detection reproducibility was high, and the detection limit was low, being available and effective for the detection of the estrogens in livestock dung. PMID:24564161

  14. miR-125b induces cellular senescence in malignant melanoma

    PubMed Central

    2014-01-01

    Background Micro RNAs (miRs) have emerged as key regulators during oncogenesis. They have been found to regulate cell proliferation, differentiation, and apoptosis. Mir-125b has been identified as an oncomir in various forms of tumours, but we have previously proposed that miR-125b is a suppressor of lymph node metastasis in cutaneous malignant melanoma. Our goal was therefore to further examine this theory. Methods We used in-situ-hybridization to visualise miR-125b expression in primary tumours and in lymph node metastasis. Then using a miRVector plasmid containing a miR-125b-1 insert we transfected melanoma cell line Mel-Juso and then investigated the effect of the presence of a stable overexpression of miR-125b on growth by western blotting, flow cytometry and ?-galactosidase staining. The tumourogenicity of the transfected cells was tested using a murine model and the tumours were further examined with in-situ-hybridization. Results In primary human tumours and in lymph node metastases increased expression of miR-125b was found in single, large tumour cells with abundant cytoplasm. A stable overexpression of miR-125b in human melanoma cell line Mel-Juso resulted in a G0/G1 cell cycle block and emergence of large cells expressing senescence markers: senescence-associated beta-galactosidase, p21, p27 and p53. Mel-Juso cells overexpressing miR-125b were tumourigenic in mice, but the tumours exhibited higher level of cell senescence and decreased expression of proliferation markers, cyclin D1 and Ki67 than the control tumours. Conclusions Our results confirm the theory that miR-125b functions as a tumour supressor in cutaneous malignant melanoma by regulating cellular senescence, which is one of the central mechanisms protecting against the development and progression of malignant melanoma. PMID:24762088

  15. Epigenetic silencing BCL6B induced colorectal cancer proliferation and metastasis by inhibiting P53 signaling

    PubMed Central

    Hu, Sui; Cao, Baoping; Zhang, Meiying; Linghu, Enqiang; Zhan, Qimin; Brock, Malcolm V; Herman, James G; Mao, Gaoping; Guo, Mingzhou

    2015-01-01

    BCL6B, a homologue of BCL6, has been reported to be frequently methylated in human gastric cancer. The epigenetic change and the function of BCL6B remains to be elucidated in colorectal cancer. 7 colorectal cancer cell lines (RKO, HT-29, DLD1, LOVO, HCT116, SW480, SW620) and 102 cases of primary colorectal cancer samples were used in this study. Semi-quantitative RT-PCR, methylation specific PCR (MSP), Flow cytometry and western blot were employed. Loss of BCL6B expression was found in HT29, RKO LOVO, SW480, SW620 and DLD1 cells, and reduced expression was found in HCT116 cell line. Complete methylation was found in HT29, RKO, LOVO, SW480, SW620 and DLD1 cells, partial methylation was detected in HCT116 cells. Restoration of BCL6B expression was induced by 5-Aza treatment in these colorectal cancer cells. BCL6B was methylated in 79.4% (81/102) of primary human colorectal cancer and reduced expression was associated with promoter region hypermethylation (p < 0.05). Methylation of BCL6B is associated with late stage (p < 0.05) and lymph node metastasis (p < 0.05). Re-expression of BCL6B inhibited cell proliferation, invasion and migration in RKO and HT29 cells. BCL6B activated P53 signaling and induced apoptosis, Re-expression of BCL6B sensitized RKO and HT29 cells to 5-fluorouracil. In conclusion, BCL6B was frequently methylated in human colorectal cancer and its expression was regulated by promoter region methylation. Methylation of BCL6B is a prognostic and chemo-sensitive marker in colorectal cancer. BCL6B suppresses colorectal cancer growth by activating P53 signaling. PMID:25973304

  16. Osteocyte Apoptosis Is Mechanically Regulated and Induces Angiogenesis In Vitro

    E-print Network

    You, Lidan

    Osteocyte Apoptosis Is Mechanically Regulated and Induces Angiogenesis In Vitro Wing-Yee Cheung,1: Osteocyte apoptosis, associated with reduced interstitial fluid flow, precedes osteoclast precursor. Totestthe associationbetweenfluidflow andosteocyte apoptosis,osteocyte-like MLO-Y4 cellsweresubjectedto

  17. CORRTEX Diagnostic Deployment for the SPE-III experiment, 24 July 2012: Fielding Report and Preliminary Data Analysis

    SciTech Connect

    Sandoval, Thomas D.; Schultz-Fellenz, Emily S.

    2012-08-29

    The Continuous Reflectometry for Radius vs Time Experiments (CORRTEX) diagnostic system was deployed for the third explosives test in the Source Physics Experiment (SPE) sequence to monitor and verify several conditions of the experiment including the detonation velocity of the explosive package and functioning of explosive initiators. Six distance-marked coaxial cables were installed on the SPE-III explosives canister, and key locations documented through along-cable length measurements and photography. CORRTEX uses electrical-pulse time-domain reflectometry to continuously record the two-way transit time (TWTT) of the cables. As the shock front of the detonation advances, the coaxial cable is shorted or destroyed, and the resulting TWTT also decreases. Interpretation of these changes as a function of TWTT can be converted to positional measurements using known parameters of the cables.

  18. Data Release Report for Source Physics Experiment 1 (SPE-1), Nevada National Security Site

    SciTech Connect

    Townsend, Margaret; Mercadente, Jennifer

    2014-04-28

    The first Source Physics Experiment shot (SPE-1) was conducted in May 2011. The explosive source was a ~100-kilogram TNT-equivalent chemical set at a depth of 60 meters. It was recorded by an extensive set of instrumentation that includes sensors both at near-field (less than 100 meters) and far-field (more than 100 meters) distances. The near-field instruments consisted of three-component accelerometers deployed in boreholes around the shot and a set of singlecomponent vertical accelerometers on the surface. The far-field network comprised a variety of seismic and acoustic sensors, including short-period geophones, broadband seismometers, three-component accelerometers, and rotational seismometers at distances of 100 meters to 25 kilometers. This report coincides with the release of these data for analysts and organizations that are not participants in this program. This report describes the first Source Physics Experiment and the various types of near-field and far-field data that are available.

  19. Characterisation of antimicrobial extracts from dandelion root (Taraxacum officinale) using LC-SPE-NMR.

    PubMed

    Kenny, O; Brunton, N P; Walsh, D; Hewage, C M; McLoughlin, P; Smyth, T J

    2015-04-01

    Plant extracts have traditionally been used as sources of natural antimicrobial compounds, although in many cases, the compounds responsible for their antimicrobial efficacy have not been identified. In this study, crude and dialysed extracts from dandelion root (Taraxacum officinale) were evaluated for their antimicrobial properties against Gram positive and Gram negative bacterial strains. The methanol hydrophobic crude extract (DRE3) demonstrated the strongest inhibition of microbial growth against Staphylococcus aureus, methicillin-resistant S. aureus and Bacillus cereus strains. Normal phase (NP) fractionation of DRE3 resulted in two fractions (NPF4 and NPF5) with enhanced antimicrobial activity. Further NP fractionation of NPF4 resulted in two fractions (NPF403 and NPF406) with increased antimicrobial activity. Further isolation and characterisation of compounds in NPF406 using liquid chromatography solid phase extraction nuclear magnetic resonance LC-SPE-NMR resulted in the identification of 9-hydroxyoctadecatrienoic acid and 9-hydroxyoctadecadienoic acid, while the phenolic compounds vanillin, coniferaldehyde and p-methoxyphenylglyoxylic acid were also identified respectively. The molecular mass of these compounds was confirmed by LC mass spectroscopy (MS)/MS. In summary, the antimicrobial efficacy of dandelion root extracts demonstrated in this study support the use of dandelion root as a source of natural antimicrobial compounds. PMID:25644491

  20. Screening organic micropollutants in surface waters by SPE extraction and ecotoxicological testing.

    PubMed

    Galassi, Silvana; Guzzella, Licia; Croce, Valeria

    2004-03-01

    Complex mixtures of toxic substances occurring in surface waters are difficult to characterise by chemical analyses because each compound occurs at a very low concentration and requires a specific analytical method to be identified. Ecotoxicological tests on water extracts can be used as a screening tool to evaluate quickly and simply the overall quality of a water body with regard to micropollutant contamination. In this work, a pre-concentration procedure based on solid-phase extraction (SPE), suitable for both biological testing and analytical determination, is proposed. The extraction procedure is an improved version of a methodology used to evaluate the toxicity of organic micropollutants occurring in surface waters. It offers the advantage of using disposable commercial cartridges, which are easier to manage than the columns prepared with macromolecular resins. Water extracts from two representative Italian rivers, characterised by a different gradient of potential contamination and prepared according to the new concentration techniques, are used. The acute toxicity of the water extracts is tested on Daphnia magna and the bioluminescence inhibition in Vibrio fischeri. Criteria based on the concentration factor (CF) are proposed for assessing the hazard to aquatic life due to the exposure to toxic substances in surface waters. The aim of hazard ranking is to focus analytical efforts towards those samples that show the highest toxic potential. PMID:14675841

  1. The determination of alkylphenols in aqueous samples from the Forth Estuary by SPE-HPLC-fluorescence.

    PubMed

    Smith, E; Ridgway, I; Coffey, M

    2001-12-01

    Nonylphenol and octylphenol have been identified as endocrine disrupters with the ability to cause reproductive deformities in a number of organisms. A normal phase high-performance liquid chromatography (HPLC) method with fluorescence detection was developed with a mobile phase of cyclohexane/methyl-tertiary-butyl ether (MTBE) (70 + 30). The extraction of the alkylphenols from the water samples was evaluated using solid-phase extraction (SPE) with a C2 packing sorbent. The complete method was validated and the limit of detection calculated to be 0.15 ppb (microg l(-1)). The method was novel for the analysis of specific alkylphenols in an aqueous matrix. A survey of the Forth Estuary in May 2000 resulted in no detectable amounts of nonyl- or octylphenol, whilst a survey during August of the same year produced concentrations ranging from 0.17-1.90 ppb for nonylphenol and 0.17-1.28 ppb for octylphenol. These results are compared with other river and estuarine studies with concentrations considered in terms of toxicity to aquatic organisms. The concentrations determined in the Forth Estuary are consistent with a contaminated though not grossly polluted estuarine system. PMID:11785635

  2. Composition and evolution of Triton's icy surface between 2002-2014 from SpeX/IRTF

    NASA Astrophysics Data System (ADS)

    Holler, Bryan J.; Young, Leslie A.; Grundy, William M.; Olkin, Cathy B.

    2015-11-01

    We observed Triton in the near-infrared (0.7-2.5 ?m) over 63 nights using the SpeX instrument at NASA's Infrared Telescope Facility (IRTF) between 2002 and 2014. Triton’s spectrum has absorption features due to N2, CO, CH4, CO2, and H2O in this wavelength range. We calculated the equivalent width (or fractional band depth for H2O) of select absorption bands in each of the 63 night-averaged spectra. Longitudinal distributions for the volatile ices (N2, CO, CH4) show large rotational amplitude, while the non-volatile ices (CO2, H2O) show little amplitude over one Triton rotation. Absorption from N2 and CH4 increased over the period of the observations, whereas absorption from the non-volatile ices remained constant. The sub-solar latitude on Triton is currently at -42 degrees south, so some areas of Triton are visible for a full rotation. Combined with our findings, this suggests that the southern latitudes are dominated by non-volatile ices, with larger concentrations of volatile ices found in the observable region north of the equator. Changing viewing geometry over the period of the observations explains the increase in volatile absorption: As the sub-solar point moves northwards, more of the volatile-rich northern regions are coming directly into view. Geological evidence from Voyager 2 pointed to a southern hemisphere dominated by volatile ices; significant changes have occurred over the intervening quarter century.

  3. Apoptosis in immune-mediated diseases

    PubMed Central

    Sankari, S. Leena; Babu, N. Aravindha; Rajesh, E.; Kasthuri, M.

    2015-01-01

    Apoptosis plays a significant role in both the physiological and pathological process. A dysfunctional apoptotic system can lead to either excessive removal or prolonged survival of cells. Therefore, dysregulation is involved in the pathogenesis of a variety of immunological diseases. The present review aims to provide an overview regarding role of apoptosis in immune-mediated disease. PMID:26015710

  4. Apoptosis in mammalian oocytes: a review.

    PubMed

    Tiwari, Meenakshi; Prasad, Shilpa; Tripathi, Anima; Pandey, Ashutosh N; Ali, Irfan; Singh, Arvind K; Shrivastav, Tulsidas G; Chaube, Shail K

    2015-08-01

    Apoptosis causes elimination of more than 99% of germ cells from cohort of ovary through follicular atresia. Less than 1% of germ cells, which are culminated in oocytes further undergo apoptosis during last phases of oogenesis and depletes ovarian reserve in most of the mammalian species including human. There are several players that induce apoptosis directly or indirectly in oocytes at various stages of meiotic cell cycle. Premature removal of encircling granulosa cells from immature oocytes, reduced levels of adenosine 3',5'-cyclic monophosphate and guanosine 3',5'-cyclic monophosphate, increased levels of calcium (Ca(2+)) and oxidants, sustained reduced level of maturation promoting factor, depletion of survival factors, nutrients and cell cycle proteins, reduced meiotic competency, increased levels of proapoptotic as well as apoptotic factors lead to oocyte apoptosis. The BH3-only proteins also act as key regulators of apoptosis in oocyte within the ovary. Both intrinsic (mitochondria-mediated) as well as extrinsic (cell surface death receptor-mediated) pathways are involved in oocyte apoptosis. BID, a BH3-only protein act as a bridge between both apoptotic pathways and its cleavage activates cell death machinery of both the pathways inside the follicular microenvironment. Oocyte apoptosis leads to the depletion of ovarian reserve that directly affects reproductive outcome of various mammals including human. In this review article, we highlight some of the important players and describe the pathways involved during oocyte apoptosis in mammals. PMID:25958165

  5. Proteases in Fas-mediated apoptosis.

    PubMed

    Zhivotovsky, B; Burgess, D H; Schlegel, J; Pörn, M I; Vanags, D; Orrenius, S

    1997-01-01

    Involvement of a unique family of cysteine proteases in the multistep apoptotic process has been documented. Cloning of several mammalian genes identifies some components of this cellular response. However, it is currently unclear which protease plays a role as a signal and/or effector of apoptosis. We summarize contributions to the data concerning proteases in Fas-mediated apoptosis. PMID:9015753

  6. THE ROLE OF APOPTOSIS IN NEUROTOXICOLOGY.

    EPA Science Inventory

    The role of apoptosis in neurodegeneration in developing animals and in adults has become increasingly apparent in the past ten years. Normal apoptosis occurs in the CNS from the embryonic stage through senescence, with different cells in each region of the nervous system having ...

  7. Colorimetric-Solid Phase Extraction Technology for Water Quality Monitoring: Evaluation of C-SPE and Debubbling Methods in Microgravity

    NASA Technical Reports Server (NTRS)

    Hazen-Bosveld, April; Lipert, Robert J.; Nordling, John; Shih, Chien-Ju; Siperko, Lorraine; Porter, Marc D.; Gazda, Daniel B.; Rutz, Jeff A.; Straub, John E.; Schultz, John R.; McCoy, J. Torin

    2007-01-01

    Colorimetric-solid phase extraction (C-SPE) is being developed as a method for in-flight monitoring of spacecraft water quality. C-SPE is based on measuring the change in the diffuse reflectance spectrum of indicator disks following exposure to a water sample. Previous microgravity testing has shown that air bubbles suspended in water samples can cause uncertainty in the volume of liquid passed through the disks, leading to errors in the determination of water quality parameter concentrations. We report here the results of a recent series of C-9 microgravity experiments designed to evaluate manual manipulation as a means to collect bubble-free water samples of specified volumes from water sample bags containing up to 47% air. The effectiveness of manual manipulation was verified by comparing the results from C-SPE analyses of silver(I) and iodine performed in-flight using samples collected and debubbled in microgravity to those performed on-ground using bubble-free samples. The ground and flight results showed excellent agreement, demonstrating that manual manipulation is an effective means for collecting bubble-free water samples in microgravity.

  8. Forward Genetics Identifies a Requirement for the Izumo-like Immunoglobulin Superfamily spe-45 Gene in Caenorhabditis elegans Fertilization.

    PubMed

    Singaravelu, Gunasekaran; Rahimi, Sina; Krauchunas, Amber; Rizvi, Anam; Dharia, Sunny; Shakes, Diane; Smith, Harold; Golden, Andy; Singson, Andrew

    2015-12-21

    Fertilization is a conserved process in all sexually reproducing organisms whereby sperm bind and fuse with oocytes. Despite the importance of sperm-oocyte interactions in fertilization, the molecular underpinnings of this process are still not well understood. The only cognate ligand-receptor pair identified in the context of fertilization is sperm-surface Izumo and egg-surface Juno in the mouse [1]. Here we describe a genetic screening strategy to isolate fertilization mutants in Caenorhabditis elegans in order to generate a more complete inventory of molecules required for gamete interactions. From this screening strategy, we identified, cloned, and characterized spe-45, a gene that encodes an Izumo-like immunoglobulin superfamily protein. Mammalian Izumo is required for male fertility and has the same basic mutant phenotype as spe-45. Worms lacking spe-45 function produce morphologically normal and motile sperm that cannot fuse with oocytes despite direct contact in the reproductive tract. The power of this screen to identify proteins with ancient sperm functions suggests that characterization of additional mutants from our screen may reveal other deeply conserved components in fertility pathways and complement studies in other organisms. PMID:26671668

  9. Analysis of drugs of abuse by online SPE-LC high resolution mass spectrometry: communal assessment of consumption.

    PubMed

    Heuett, Nubia V; Ramirez, Cesar E; Fernandez, Adolfo; Gardinali, Piero R

    2015-04-01

    An online SPE-LC-HRMS method was developed to monitor the consumption of 18 drugs of abuse (DOAs) including amphetamines, opioids, cocainics, cannabinoids, lysergics, and their corresponding metabolites in a well characterized college campus setting via wastewater analysis. Filtered and diluted (10×) sewage water samples (5 mL inj.) were automatically pre-concentrated and analyzed in 15 min using a Thermo EQuan MAX online SPE system equipped with a HyperSep™ Retain PEP (20×2.1 mm×12 ?m) SPE column and a Hypersil Gold™ aQ (150×2.1 mm×3 ?m) analytical column. A Q Exactive™ Hybrid Quadrupole-Orbitrap HRMS was used in full scan mode (R=140,000) for positive identification, and quantitation of target compounds. Method detection limits for all analytes ranged between 0.6 and 1.7 ng/L in sewage. A total of 14 DOAs were detected from two different locations (dorms and main college campus) within a one-year period. Most frequently detected drugs throughout the entire study were amphetamine (>96%) and THC's metabolite 11-nor-9-carboxy-?-9-THC (>100%) with maximum concentrations of 5956 and 2413 ng/L respectively. Daily doses per 1000 people were determined in order to assess consumption of THC, amphetamine, heroin and cocaine, in both dorms and main campus. PMID:25553546

  10. Solid-phase extraction and purification of membrane proteins using a UV-modified PMMA microfluidic bioaffinity ?SPE device.

    PubMed

    Battle, Katrina N; Jackson, Joshua M; Witek, Ma?gorzata A; Hupert, Mateusz L; Hunsucker, Sally A; Armistead, Paul M; Soper, Steven A

    2014-03-21

    We present a novel microfluidic solid-phase extraction (?SPE) device for the affinity enrichment of biotinylated membrane proteins from whole cell lysates. The device offers features that address challenges currently associated with the extraction and purification of membrane proteins from whole cell lysates, including the ability to release the enriched membrane protein fraction from the extraction surface so that they are available for downstream processing. The extraction bed was fabricated in PMMA using hot embossing and was comprised of 3600 micropillars. Activation of the PMMA micropillars by UV/O3 treatment permitted generation of surface-confined carboxylic acid groups and the covalent attachment of NeutrAvidin onto the ?SPE device surfaces, which was used to affinity select biotinylated MCF-7 membrane proteins directly from whole cell lysates. The inclusion of a disulfide linker within the biotin moiety permitted release of the isolated membrane proteins via DTT incubation. Very low levels (?20 fmol) of membrane proteins could be isolated and recovered with ?89% efficiency with a bed capacity of 1.7 pmol. Western blotting indicated no traces of cytosolic proteins in the membrane protein fraction as compared to significant contamination using a commercial detergent-based method. We highlight future avenues for enhanced extraction efficiency and increased dynamic range of the ?SPE device using computational simulations of different micropillar geometries to guide future device designs. PMID:24487280

  11. Critical role of ARID3B in the expression of pro-apoptotic p53-target genes and apoptosis.

    PubMed

    Pratama, Endrawan; Tian, Xiaohui; Lestari, Widya; Iseki, Sachiko; Ichwan, Solachuddin J A; Ikeda, Masa-Aki

    2015-12-01

    ARID3A and ARID3B are transcriptional targets of p53. Recently, it has been reported that ARID3A plays a critical role in the transcriptional activation of pro-arrest p21 in response to DNA damage. However, the role of ARID3B in the p53 regulatory pathway remains poorly understood. Here we show that ARID3A and ARID3B specifically bind to putative ARID3-binding sites in p53 target genes in vitro and in vivo. ARID3B and, to a lesser extent, ARID3A silencing blocked transcriptional activation of pro-apoptotic p53 target genes, such as PUMA, PIG3, and p53. Furthermore, ectopic ARID3B, to a lesser extent, ARID3A expression activated the pro-apoptotic gene expression, and only ARID3B induced apoptosis. Finally, ARID3B but not ARID3A silencing blocked apoptosis induction following DNA damage. These results indicated that, although ARID3B and ARID3A share overlapping functions, ARID3B play a key role in the expression of pro-apoptotic p53-target genes and apoptosis. PMID:26519881

  12. Apoptosis inducers in chronic lymphocytic leukemia

    PubMed Central

    Billard, Christian

    2014-01-01

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

  13. Effects of different light conditions on repair of UV-B-induced damage in carpospores of Chondrus ocellatus Holm

    NASA Astrophysics Data System (ADS)

    Ju, Qing; Xiao, Hui; Wang, You; Tang, Xuexi

    2015-05-01

    We evaluated the effects of ultraviolet-B (UV-B) radiation and different light conditions on the repair of UV-B-induced damage in carpospores of Chondrus ocellatus Holm (Rhodophyta) in laboratory experiments. Carpospores were treated daily with different doses of UV-B radiation for 48 days, when vertical branches had formed in all treatments; after each daily treatment, the carpospores were subjected to photosynthetically active radiation (PAR), darkness, red light, or blue light during a 2-h repair stage. Carpospore diameters were measured every 4 days. We measured the growth and cellular contents of cyclobutane pyrimidine dimers (CPDs), chlorophyll a, phycoerythrin, and UV-B-absorbing mycosporine-like amino acids (MAAs) in carpospores on Day 48. Low doses of UV-B radiation (36 and 72 J/m2) accelerated the growth of C. ocellatus. However, as the amount of UV-B radiation increased, the growth rate decreased and morphological changes occurred. UV-B radiation significant damaged DNA and photosynthetic pigments and induced three kind of MAAs, palythine, asterina-330, and shinorine. PAR conditions were best for repairing UV-B-induced damage. Darkness promoted the activity of the DNA darkrepair mechanism. Red light enhanced phycoerythrin synthesis but inhibited light repair of DNA. Although blue light, increased the activity of DNA photolyase, greatly improving remediation efficiency, the growth and development of C. ocellatus carpospores were slower than in other light treatments.

  14. Photo-protective effect of americanin B against ultraviolet B-induced damage in cultured human keratinocytes.

    PubMed

    Zheng, Jian; Piao, Mei Jing; Kim, Ki Cheon; Yao, Cheng Wen; Cha, Ji Won; Shin, Jennifer H; Yoo, Suk Jae; Hyun, Jin Won

    2014-11-01

    Excessive ultraviolet (UV) radiation, a constituent of sunlight, can induce multiple types of skin damage. We recently demonstrated that americanin B, a lignin compound, protected cells against hydrogen peroxide (H2O2)-induced damage by exerting antioxidant effects and inhibiting apoptosis. In this study, we investigated the ability of americanin B to protect against cell injury induced by UVB (280-320nm), the most harmful UV wavelengths, in human HaCaT keratinocytes. Americanin B absorbed UVB, eliminated UVB-induced intracellular reactive oxygen species (ROS), and decreased the extent of UVB-induced oxidative modification of lipids, proteins, and DNA. In addition, americanin B inhibited UVB-induced apoptosis, as indicated by reductions in apoptotic body formation and DNA fragmentation. Furthermore, americanin B reversed the depolarization of the mitochondrial membrane induced by UVB exposure. These protective activities were associated with down-regulation of apoptosis-promoting proteins, Bax, caspase-9, and caspase-3 and up-regulation of an apoptosis inhibitor, Bcl-2. These results suggest that americanin B can protect human keratinocytes against UVB-induced cell damage. PMID:25461549

  15. Geologic Assessment of the Damage Zone from the Second Test at Source Physics Experiment-Nevada (SPE-N)

    SciTech Connect

    ,

    2012-09-18

    The National Center for Nuclear Security (NCNS), established by the U.S. Department of Energy, National Nuclear Security Administration, is conducting a series of explosive tests at the Nevada National Security Site (NNSS; formerly the Nevada Test Site) that are designed to increase the understanding of certain basic physical phenomena associated with underground explosions. These tests will aid in developing technologies that might be used to detect underground nuclear explosions in support of verification activities for the Comprehensive Nuclear-Test-Ban Treaty (CTBT). The initial NCNS project is a series of explosive tests, known collectively as the Source Physics Experiment at the NNSS (SPE-N), being conducted in granitic rocks at the Climax stock in northern Yucca Flat. The SPE-N test series is designed to study the generation and propagation of seismic waves. The data will be used to improve the predictive capability of calculational models for detecting and characterizing underground explosions. The first SPE-N test (SPE-N-1) was a “calibration” shot conducted in May 2011, using 100 kilograms (kg) of explosives at the depth of 54.9 meters (m) (180 feet [ft]) in the U-15n source hole. SPE-N-2 was conducted in October 2011, using 1,000 kg of explosives at the depth of 45.7 m (150 ft) in the same source hole. Following the SPE-N-2 test, the core hole U-15n#10 was drilled at an angle from the surface to intercept the SPE-N-2 shot point location to obtain information necessary to characterize the damage zone. The desire was to determine the position of the damage zone near the shot point, at least on the northeast side, where the core hole penetrated it. The three-dimensional shape and symmetry of the damage zone are unknown at this time. Rather than spherical in shape, the dimensions of the damage zone could be influenced by the natural fracture sets in the vicinity. Geologic characterization of the borehole included geophysical logging, a directional survey, and geologic description of the core to document visual evidence of damage. Selected core samples were provided to Sandia National Laboratories (SNL) for laboratory tests (to be reported by SNL). A significant natural fault zone was encountered in the U-15n#10 angle core hole between the drilled depths of 149 and 155 ft (straight-line distance or range station [RS] from the shot point of 7.5 to 5.7 m). However, several of the fractures observed in the U-15n#10 hole are interpreted as having been caused by the explosion. These fractures are characterized by a “fresh,” mechanically broken look, with uncoated and very irregular surfaces. They tend to terminate against natural fractures and have orientations that differ from the previously defined natural fracture sets. The most distant fracture from the shot point that could be interpreted as having been caused by the explosion was seen at approximately RS 10.0 m. No other possibly explosion-induced fractures are apparent above the fault, but are common starting at RS 5.4 m, which is below the fault. It is unknown how the fault zone might have affected the propagation of seismic waves or how the materials in the fault zone (altered granite, breccia, gouge) were affected by the explosion. From RS 3.3 m to the end of the recovered core at RS 1.6 m, some of the core samples are softer and lighter in color, but do not appear to be weathered. It is thought this could be indicative of the presence of distributed microfracturing.

  16. Hyperthermia induces apoptosis in thymocytes

    SciTech Connect

    Sellins, K.S.; Cohen, J.J. )

    1991-04-01

    Mild hyperthermia (43{degree}C for 1 h) induces extensive double-stranded DNA fragmentation and, at a later time, cell death in murine thymocytes. The cleavage of DNA into oligonucleosome-sized fragments resembles that observed in examples of apoptosis including radiation-induced death of thymocytes. Following hyperthermia, incubation at 37{degree}C is necessary to detect DNA fragmentation, although protein and RNA synthesis do not seem to be required. Two protein synthesis inhibitors, cycloheximide and emetine, and two RNA synthesis inhibitors, actinomycin D and 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole, do not inhibit DNA fragmentation or cell death in heated thymocytes at concentrations which significantly block these effects in irradiated thymocytes. We have used this difference in sensitivity to show that the DNA fragmentation induced in thymocytes which are irradiated and then heated seems to be caused only by the heating and not by the irradiation.

  17. Proneurotrophins, Seizures, and Neuronal Apoptosis

    PubMed Central

    Friedman, Wilma J.

    2010-01-01

    Neurons respond to numerous factors in their environment that influence their survival and function during development and in the mature brain. Among these factors, the neurotrophins have been shown to support neuronal survival and function, acting primarily through the Trk family of receptor tyrosine kinases. However, recent studies have established that the uncleaved neurotrophin precursors, the proneurotrophins, can be secreted and induce apoptosis via the p75 neurotrophin receptor, suggesting that the balance of secreted mature and proneurotrophins has a critical impact on neuronal survival or death. Epileptic seizures elicit increases in both proneurotrophin secretion and p75NTR expression, shifting the balance of these factors toward signaling cell death. This review will discuss the evidence that this ligand-receptor system plays an important role in neuronal loss following seizures. PMID:20360602

  18. Optimization of a pre-MEKC separation SPE procedure for steroid molecules in human urine samples.

    PubMed

    Ol?dzka, Ilona; Kowalski, Piotr; Dziomba, Szymon; Szmudanowski, Piotr; B?czek, Tomasz

    2013-01-01

    Many steroid hormones can be considered as potential biomarkers and their determination in body fluids can create opportunities for the rapid diagnosis of many diseases and disorders of the human body. Most existing methods for the determination of steroids are usually time- and labor-consuming and quite costly. Therefore, the aim of analytical laboratories is to develop a new, relatively low-cost and rapid implementation methodology for their determination in biological samples. Due to the fact that there is little literature data on concentrations of steroid hormones in urine samples, we have made attempts at the electrophoretic determination of these compounds. For this purpose, an extraction procedure for the optimized separation and simultaneous determination of seven steroid hormones in urine samples has been investigated. The isolation of analytes from biological samples was performed by liquid-liquid extraction (LLE) with dichloromethane and compared to solid phase extraction (SPE) with C18 and hydrophilic-lipophilic balance (HLB) columns. To separate all the analytes a micellar electrokinetic capillary chromatography (MECK) technique was employed. For full separation of all the analytes a running buffer (pH 9.2), composed of 10 mM sodium tetraborate decahydrate (borax), 50 mM sodium dodecyl sulfate (SDS), and 10% methanol was selected. The methodology developed in this work for the determination of steroid hormones meets all the requirements of analytical methods. The applicability of the method has been confirmed for the analysis of urine samples collected from volunteers--both men and women (students, amateur bodybuilders, using and not applying steroid doping). The data obtained during this work can be successfully used for further research on the determination of steroid hormones in urine samples. PMID:24232737

  19. The SpeX Prism Library Analysis Toolkit: Design Considerations and First Results

    NASA Astrophysics Data System (ADS)

    Burgasser, Adam J.; Aganze, Christian; Escala, Ivana; Lopez, Mike; Choban, Caleb; Jin, Yuhui; Iyer, Aishwarya; Tallis, Melisa; Suarez, Adrian; Sahi, Maitrayee

    2016-01-01

    Various observational and theoretical spectral libraries now exist for galaxies, stars, planets and other objects, which have proven useful for classification, interpretation, simulation and model development. Effective use of these libraries relies on analysis tools, which are often left to users to develop. In this poster, we describe a program to develop a combined spectral data repository and Python-based analysis toolkit for low-resolution spectra of very low mass dwarfs (late M, L and T dwarfs), which enables visualization, spectral index analysis, classification, atmosphere model comparison, and binary modeling for nearly 2000 library spectra and user-submitted data. The SpeX Prism Library Analysis Toolkit (SPLAT) is being constructed as a collaborative, student-centered, learning-through-research model with high school, undergraduate and graduate students and regional science teachers, who populate the database and build the analysis tools through quarterly challenge exercises and summer research projects. In this poster, I describe the design considerations of the toolkit, its current status and development plan, and report the first published results led by undergraduate students. The combined data and analysis tools are ideal for characterizing cool stellar and exoplanetary atmospheres (including direct exoplanetary spectra observations by Gemini/GPI, VLT/SPHERE, and JWST), and the toolkit design can be readily adapted for other spectral datasets as well.This material is based upon work supported by the National Aeronautics and Space Administration under Grant No. NNX15AI75G. SPLAT code can be found at https://github.com/aburgasser/splat.

  20. Destruxin B Isolated from Entomopathogenic Fungus Metarhizium anisopliae Induces Apoptosis via a Bcl-2 Family-Dependent Mitochondrial Pathway in Human Nonsmall Cell Lung Cancer Cells

    PubMed Central

    Wu, Chun-Chi; Chen, Tzu-Hsiu; Liu, Bing-Lan; Wu, Li-Chen; Chen, Yung-Ching; Tzeng, Yew-Min; Hsu, Shih-Lan

    2013-01-01

    Destruxin B, isolated from entomopathogenic fungus Metarhizium anisopliae, is one of the cyclodepsipeptides with insecticidal and anticancer activities. In this study, destruxin B was extracted and purified by ion-exchange chromatography, silica gel chromatography, and semipreparative high-performance liquid chromatography. The potential anticancer effects and molecular mechanisms of destruxin B in human nonsmall cell lung cancer cell lines were characterized. Our results showed that destruxin B induced apoptotic cell death in A549 cells. This event was accompanied by the activation of caspase-2, -3, and -9. Moreover, destruxin B increased the expression level of proapoptotic molecule, PUMA, while decreased antiapoptotic molecule Mcl-1. Additionally, the translocation of Bax from cytosol to mitochondrial membrane was observed upon destruxin B treatment. Knockdown of Bax by shRNA effectively attenuated destruxin-B-triggered apoptosis in A549 cells. Interestingly, similar toxic effects and underlying mechanisms including caspase activation, upregulation of PUMA, and downregulation of Mcl-1 were also observed in a p53-null lung cancer H1299 cell line upon destruxin B treatment. Taken together, our findings suggest that destruxin-B-induced apoptosis in human nonsmall cell lung cancer cells is via a Bcl-2 family-dependent mitochondrial pathway. PMID:24204395

  1. A novel polyamine allosteric site of SpeG from Vibrio cholerae is revealed by Its dodecameric structure

    SciTech Connect

    Filippova, Ekaterina V.; Kuhn, Misty L.; Osipiuk, Jerzy; Kiryukhina, Olga; Joachimiak, Andrzej; Ballicora, Miguel A.; Anderson, Wayne F.

    2015-03-01

    Spermidine N-acetyltransferase, encoded by the gene speG, catalyzes the initial step in the degradation of polyamines and is a critical enzyme for determining the polyamine concentrations in bacteria. In Escherichia coli, studies have shown that SpeG is the enzyme responsible for acetylating spermidine under stress conditions and for preventing spermidine toxicity. Not all bacteria contain speG, and many bacterial pathogens have developed strategies to either acquire or silence it for pathogenesis. Here, we present thorough kinetic analyses combined with structural characterization of the VCA0947 SpeG enzyme from the important human pathogen Vibrio cholerae. Our studies revealed the unexpected presence of a previously unknown allosteric site and an unusual dodecameric structure for a member of the Gcn5-related N-acetyltransferase superfamily. We show that SpeG forms dodecamers in solution and in crystals and describe its three-dimensional structure in several ligand-free and liganded structures. Importantly, these structural data define the first view of a polyamine bound in an allosteric site of an N-acetyltransferase. Kinetic characterization of SpeG from V. cholerae showed that it acetylates spermidine and spermine. The behavior of this enzyme is complex and exhibits sigmoidal curves and substrate inhibition. We performed a detailed non-linear regression kinetic analysis to simultaneously fit families of substrate saturation curves to uncover a simple kinetic mechanism that explains the apparent complexity of this enzyme. Our results provide a fundamental understanding of the bacterial SpeG enzyme, which will be key toward understanding the regulation of polyamine levels in bacteria during pathogenesis.

  2. Apoptosis: a guide for the perplexed.

    PubMed

    Sloviter, Robert S

    2002-01-01

    The term 'apoptosis' describes an active process of cellular deconstruction originally contrasted morphologically with necrosis. The mistaken equivalence of the terms apoptosis and 'programmed cell death' has caused confusion and implied that apoptosis is an identifiable therapeutic target rather than a name of a type of cell death. The roots of confusion are suggested to lie not in superficial disagreements about the morphology and biochemistry of cell death, but in the lamentable disconnection of modern science from its philosophical foundations (i.e. Socratic definition, nominalism versus realism, and William of Ockham's advocacy of Aristotelian metaphysics over Plato's Theory of Forms). Renewed awareness of these issues might be the key to understanding that apoptosis is a created concept, not a real entity, and that the use of terms that defy definition has become an obstacle to clear thinking about preventable cell death. PMID:11804647

  3. Simple SPE-HPLC determination of some common drugs and herbicides of environmental concern by pulsed amperometry.

    PubMed

    Rivoira, L; De Carlo, R M; Cavalli, S; Bruzzoniti, M C

    2015-01-01

    In this work the electrochemical behavior of substances of environmental concern [bentazone, atrazine, carbamazepine, phenytoin and its metabolite 5-(4-hydroxyphenyl)-5-phenylhydantoin, HPPH] on a glassy carbon working electrode (Ag/AgCl reference electrode) was studied with the aim to develop a HPLC method coupled with amperometric detection. Constant potential (DC), pulsed amperometric detection modes were studied. For the pulsed mode, several waveforms were set and investigated. Detection conditions were optimized as a function of eluent pH. In order to reduce the limits of detection and to analyze natural water samples, a SPE protocol was optimized to be coupled to the developed procedure. For this aim, five sorbents of different physico-chemical characteristics were tested optimizing a recovery procedure for each of the cartridge evaluated. At the optimized SPE conditions, recoveries were included in the range (R=90.2-100.5% for all the analytes, with excellent reproducibility (<%, n=3). The method detection limits obtained by pulsed amperometry after the SPE protocol (preconcentration factor 100) were 113 ng L(-1) (0.47 nmol L(-1)), 67 ng L(-1) (0.25 nmol L(-1)), 234 ng L(-1) (1.1 nmol L(-1)), for bentazone, HPPH and carbamazepine, respectively. Robustness of the method was assessed for each analyte at a concentration level corresponding to about three times the limit of detection, through the evaluation of intra-day (n=13) and inter-day tests (4 days, n=52). Finally the method was successfully applied for the analysis of a river sample (Po River, Turin, Italy). PMID:25281094

  4. DOE/NV/25946--1586 Geologic Assessment of the Damage Zone from the Second Test at Source Physics Experiment-Nevada (SPE-N)

    NASA Astrophysics Data System (ADS)

    Townsend, M.; Huckins-Gang, H.; Prothro, L.; Reed, D.

    2012-12-01

    The National Center for Nuclear Security, established by the U.S. Department of Energy, National Nuclear Security Administration, is conducting a series of explosive tests at the Nevada National Security Site that are designed to increase the understanding of certain basic physical phenomena associated with underground explosions. These tests will aid in developing technologies that might be used to detect underground nuclear explosions in support of verification activities for the Comprehensive Nuclear-Test-Ban Treaty. The initial project is a series of explosive tests, known collectively as the Source Physics Experiment-Nevada (SPE-N), being conducted in granitic rocks. The SPE N test series is designed to study the generation and propagation of seismic waves. The results will help advance the seismic monitoring capability of the United States by improving the predictive capability of physics-based modeling of explosive phenomena. The first SPE N (SPE N1) test was conducted in May 2011, using 0.1 ton of explosives at the depth of 54.9 m in the U 15n source hole. SPE N2 was conducted in October 2011, using 1.0 ton of explosives at the depth of 45.7 m in the same source hole. The SPE N3 test was conducted in the same source hole in July 2012, using the same amount and type of explosive as for SPE N2, and at the same depth as SPE N2, within the damage zone created by the SPE N2 explosion to investigate damage effects on seismic wave propagation. Following the SPE N2 shot and prior to the SPE N3 shot, the core hole U-15n#10 was drilled at an angle from the surface to intercept the SPE N2 shot point location to obtain information necessary to characterize the damage zone. The desire was to determine the position of the damage zone near the shot point, at least on the northeast, where the core hole penetrated it, and obtain information on the properties of the damaged medium. Geologic characterization of the post-SPE N2 core hole included geophysical logging, a directional survey, and geologic description of the core to document visual evidence of damage. Selected core samples were provided to Sandia National Laboratories for measurement of physical and mechanical properties. A video was also run in the source hole after it was cleaned out. A significant natural fault zone was encountered in the angle core hole between 5.7 and 7.5 m from the shot point. However, several of the fractures observed in the core hole are interpreted as having been caused by the explosion. The fractures are characterized by a "fresh," mechanically broken look, with uncoated and very irregular surfaces. They tend to terminate against natural fractures and have orientations that differ from the previously defined natural fracture sets; they are common starting at about 5.4 m from the shot point. Within about 3.3 m of the shot point to the end of the recovered core at 1.6 m from the shot point, some of the core samples are softer and lighter in color, but do not appear to be weathered. It is thought this could be indicative of the presence of distributed microfracturing. This work was done by National Security Technologies, LLC, under Contract No. DE-AC52-06NA25946 with the U.S. Department of Energy.

  5. DPI induces mitochondrial superoxide-mediated apoptosis.

    PubMed

    Li, Nianyu; Ragheb, Kathy; Lawler, Gretchen; Sturgis, Jennie; Rajwa, Bartek; Melendez, J Andres; Robinson, J Paul

    2003-02-15

    The iodonium compounds diphenyleneiodonium (DPI) and diphenyliodonium (IDP) are well-known phagocyte NAD(P)H oxidase inhibitors. However, it has been shown that at high concentrations they can inhibit the mitochondrial respiratory chain as well. Since inhibition of the mitochondrial respiratory chain has been shown to induce superoxide production and apoptosis, we investigated the effect of iodonium compounds on mitochondria-derived superoxide and apoptosis. Mitochondrial superoxide production was measured on both cultured cells and isolated rat-heart submitochondrial particles. Mitochondria function was examined by monitoring mitochondrial membrane potential. Apoptotic pathways were studied by measuring cytochrome c release and caspase 3 activation. Apoptosis was characterized by detecting DNA fragmentation on agarose gel and measuring propidium iodide- (PI-) stained subdiploid cells using flow cytometry. Our results showed that DPI could induce mitochondrial superoxide production. The same concentration of DPI induced apoptosis by decreasing mitochondrial membrane potential and releasing cytochrome c. Addition of antioxidants or overexpression of MnSOD significantly reduced DPI-induced mitochondrial damage, cytochrome c release, caspase activation, and apoptosis. These observations suggest that DPI can induce apoptosis via induction of mitochondrial superoxide. DPI-induced mitochondrial superoxide production may prove to be a useful model to study the signaling pathways of mitochondrial superoxide. PMID:12566072

  6. Study of apoptosis in human liver cancers

    PubMed Central

    Shan, Chang-Min; Li, Juan

    2002-01-01

    AIM: To investigate the action of apoptosis in occurrence of liver cacinomas in vivo and the biological effect of Solanum lyratum Thumb on BEL-7404 cell line inducing apoptosis in vitro. METHODS: The apoptosis in the liver carcinoma was detected with terminal deoxynucl neotidyl transferase mediated dUTP nick end labelling (TUNEL); the cancer cells cultured in DMED medium were treated with extract of Solanum lyratum Thumb and observed under microscope, and their DNA was assayed by gel electrophoresis. RESULTS: In vivo apoptotic cells in the cancer adjacent tissues inceased; in vitro treatment of liver cancers with extract of Solanum lyratum Thumb could induce the cells to manifest a typical apoptotic morphology. Their DNA was fractured and a characteristic ladder pattern could be found using electrophoresis. CONCLUSION: In vivo the apoptosis of carcinomas was lower; maybe the cells divided quickly and then the cancers occurred. In the cancer adjacent tissues, the apoptosis pricked up, and in vitro Solanum lyratum Thumb could induce the apoptosis of BEL-7404 cells. PMID:11925601

  7. Development of colorimetric solid Phase Extraction (C-SPE) for in-flight Monitoring of spacecraft Water Supplies

    SciTech Connect

    Daniel Bryan Gazda

    2004-12-19

    Although having recently been extremely successful gathering data on the surface of Mars, robotic missions are not an effective substitute for the insight and knowledge about our solar system that can be gained though first-hand exploration. Earlier this year, President Bush presented a ''new course'' for the U.S. space program that shifts NASA's focus to the development of new manned space vehicles to the return of humans to the moon. Re-establishing the human presence on the moon will eventually lead to humans permanently living and working in space and also serve as a possible launch point for missions into deeper space. There are several obstacles to the realization of these goals, most notably the lack of life support and environmental regeneration and monitoring hardware capable of functioning on long duration spaceflight. In the case of the latter, past experience on the International Space Station (ISS), Mir, and the Space Shuttle has strongly underscored the need to develop broad spectrum in-flight chemical sensors that: (1) meet current environmental monitoring requirements on ISS as well as projected requirements for future missions, and (2) enable the in-situ acquisition and analysis of analytical data in order to further define on-orbit monitoring requirements. Additionally, systems must be designed to account for factors unique to on-orbit deployment such as crew time availability, payload restrictions, material consumption, and effective operation in microgravity. This dissertation focuses on the development, ground testing, and microgravity flight demonstration of Colorimetric Solid Phase Extraction (C-SPE) as a candidate technology to meet the near- and long-term water quality monitoring needs of NASA. The introduction will elaborate further on the operational and design requirements for on-orbit water quality monitoring systems by discussing some of the characteristics of an ''ideal'' system. A description of C-SPE and how the individual components of the platform are combined to satisfy many of these requirements is then presented, along with a literature review on the applications of C-SPE and similar sorption-spectrophotometric techniques. Finally, a brief overview of diffuse reflection spectroscopy and the Kubelka-Munk function, which are used to quantify analytes via C-SPE, is presented.

  8. Broad-Spectrum Antibiotic or G-CSF as Potential Countermeasures for Impaired Control of Bacterial Infection Associated with an SPE Exposure during Spaceflight

    PubMed Central

    Li, Minghong; Holmes, Veronica; Ni, Houping; Sanzari, Jenine K.; Romero-Weaver, Ana L.; Lin, Liyong; Carabe-Fernandez, Alejandro; Diffenderfer, Eric S.; Kennedy, Ann R.; Weissman, Drew

    2015-01-01

    A major risk for astronauts during prolonged space flight is infection as a result of the combined effects of microgravity, situational and confinement stress, alterations in food intake, altered circadian rhythm, and radiation that can significantly impair the immune system and the body’s defense systems. We previously reported a massive increase in morbidity with a decrease in the ability to control a bacterial challenge when mice were maintained under hindlimb suspension (HS) conditions and exposed to solar particle event (SPE)-like radiation. HS and SPE-like radiation treatment alone resulted in a borderline significant increase in morbidity. Therefore, development and testing of countermeasures that can be used during extended space missions in the setting of exposure to SPE radiation becomes a serious need. In the present study, we investigated the efficacy of enrofloxacin (an orally bioavailable antibiotic) and Granulocyte colony stimulating factor (G-CSF) (Neulasta) on enhancing resistance to Pseudomonas aeruginosa infection in mice subjected to HS and SPE-like radiation. The results revealed that treatment with enrofloxacin or G-CSF enhanced bacterial clearance and significantly decreased morbidity and mortality in challenged mice exposed to suspension and radiation. These results establish that antibiotics, such as enrofloxacin, and G-CSF could be effective countermeasures to decrease the risk of bacterial infections after exposure to SPE radiation during extended space flight, thereby reducing both the risk to the crew and the danger of mission failure. PMID:25793272

  9. Chondrocyte Apoptosis in the Pathogenesis of Osteoarthritis.

    PubMed

    Hwang, Hyun Sook; Kim, Hyun Ah

    2015-01-01

    Apoptosis is a highly-regulated, active process of cell death involved in development, homeostasis and aging. Dysregulation of apoptosis leads to pathological states, such as cancer, developmental anomalies and degenerative diseases. Osteoarthritis (OA), the most common chronic joint disease in the elderly population, is characterized by progressive destruction of articular cartilage, resulting in significant disability. Because articular cartilage depends solely on its resident cells, the chondrocytes, for the maintenance of extracellular matrix, the compromising of chondrocyte function and survival would lead to the failure of the articular cartilage. The role of subchondral bone in the maintenance of proper cartilage matrix has been suggested as well, and it has been proposed that both articular cartilage and subchondral bone interact with each other in the maintenance of articular integrity and physiology. Some investigators include both articular cartilage and subchondral bone as targets for repairing joint degeneration. In late-stage OA, the cartilage becomes hypocellular, often accompanied by lacunar emptying, which has been considered as evidence that chondrocyte death is a central feature in OA progression. Apoptosis clearly occurs in osteoarthritic cartilage; however, the relative contribution of chondrocyte apoptosis in the pathogenesis of OA is difficult to evaluate, and contradictory reports exist on the rate of apoptotic chondrocytes in osteoarthritic cartilage. It is not clear whether chondrocyte apoptosis is the inducer of cartilage degeneration or a byproduct of cartilage destruction. Chondrocyte death and matrix loss may form a vicious cycle, with the progression of one aggravating the other, and the literature reveals that there is a definite correlation between the degree of cartilage damage and chondrocyte apoptosis. Because current treatments for OA act only on symptoms and do not prevent or cure OA, chondrocyte apoptosis would be a valid target to modulate cartilage degeneration. PMID:26528972

  10. Chondrocyte Apoptosis in the Pathogenesis of Osteoarthritis

    PubMed Central

    Hwang, Hyun Sook; Kim, Hyun Ah

    2015-01-01

    Apoptosis is a highly-regulated, active process of cell death involved in development, homeostasis and aging. Dysregulation of apoptosis leads to pathological states, such as cancer, developmental anomalies and degenerative diseases. Osteoarthritis (OA), the most common chronic joint disease in the elderly population, is characterized by progressive destruction of articular cartilage, resulting in significant disability. Because articular cartilage depends solely on its resident cells, the chondrocytes, for the maintenance of extracellular matrix, the compromising of chondrocyte function and survival would lead to the failure of the articular cartilage. The role of subchondral bone in the maintenance of proper cartilage matrix has been suggested as well, and it has been proposed that both articular cartilage and subchondral bone interact with each other in the maintenance of articular integrity and physiology. Some investigators include both articular cartilage and subchondral bone as targets for repairing joint degeneration. In late-stage OA, the cartilage becomes hypocellular, often accompanied by lacunar emptying, which has been considered as evidence that chondrocyte death is a central feature in OA progression. Apoptosis clearly occurs in osteoarthritic cartilage; however, the relative contribution of chondrocyte apoptosis in the pathogenesis of OA is difficult to evaluate, and contradictory reports exist on the rate of apoptotic chondrocytes in osteoarthritic cartilage. It is not clear whether chondrocyte apoptosis is the inducer of cartilage degeneration or a byproduct of cartilage destruction. Chondrocyte death and matrix loss may form a vicious cycle, with the progression of one aggravating the other, and the literature reveals that there is a definite correlation between the degree of cartilage damage and chondrocyte apoptosis. Because current treatments for OA act only on symptoms and do not prevent or cure OA, chondrocyte apoptosis would be a valid target to modulate cartilage degeneration. PMID:26528972

  11. An automated SPE/LC/MS/MS method for the analysis of cocaine and metabolites in whole blood.

    PubMed

    Jagerdeo, Eshwar; Montgomery, Madeline A; Lebeau, Marc A; Sibum, Martin

    2008-10-15

    As laboratories are called upon to develop novel, fast, and sensitive methods, here we present a completely automated method for the analysis of cocaine and its metabolites (benzoylecgonine, ecgonine methyl ester, ecgonine and cocaethylene) from whole blood. This method utilizes an online solid-phase extraction (SPE) with high performance liquid chromatographic separation and tandem mass spectrometric detection. Pretreatment of samples involve only protein precipitation and ultracentrifugation. An efficient online solid-phase extraction (SPE) procedure was developed using Hysphere MM anion sorbent. A gradient chromatography method with a Gemini C6-Phenyl (50mmx3.00mm i.d., 5microm) column was used for the complete separation of all components. Analysis was by positive ion mode electrospray ionization tandem mass spectrometry, using multiple reaction monitoring (MRM) to enhance the selectivity and sensitivity of the method. For the analysis, two MRM transitions are monitored for each analyte and one transition is monitored for each internal standard. With a 30-microL sample injection, linearity was analyte dependent but generally fell between 8 and 500ng/mL. The limits of detection (LODs) for the method ranged from 3 to 16ng/mL and the limits of quantitation (LOQs) ranged from 8 to 47ng/mL. The bias and precision were determined using a simple analysis of variance (ANOVA: single factor). The results demonstrate bias as <7%, and %precision as <9% for all components at each QC level. PMID:18829399

  12. Development and validation of an on-line multidimensional SPE-LC-MS/MS method for the quantitation of Tetrandrine in blood samples.

    PubMed

    Caglar, Sena; Morello, Rosa; Boos, Karl-Siegfried

    2015-04-15

    On-line solid-phase extraction (SPE) is becoming an increasingly widespread technique in the clean-up of complex matrices such as body fluids, prior to chromatographic analysis. The use of small SPE columns instead of disposable SPE cartridges allows multiple injections and complete automation. In addition, it decreases the cost of consumables and improves the quality of the overall analysis. Coupling of SPE with HPLC combines sample preparation and separation in one system. In this paper a validated on-line multidimensional (MD) SPE-LC-MS/MS method is described for the determination of Tetrandrine (model drug) in human blood samples. The developed method showed the applicability of direct injection of plasma samples to an on-line MD-SPE-LC-MS/MS system to determine small molecules i.e. drugs. The experimental design is unique. Quantification was through tandem mass spectrometry with positive electrospray ionization (ESI) and multiple reactions monitoring (MRM). The limit of detection was calculated as 31.98 ng/mL. The linear range of the method was between 40.0 and 800.0 ng/mL. Pharmacokinetic parameters are usually determined by analysis of drug concentrations in plasma rather than whole blood. Parameters determined using plasma data may be misleading if concentrations of drug differ between plasma and red blood cells. We successfully applied the developed method for the determination of the distribution coefficient of the model drug Tetrandrine between human red blood cells and blood plasma proteins. The determination of distribution coefficient study results demonstrated that the developed method can provide direct and accurate measurement of RBC partitioning in a model drug and could be applied for screening of other compounds for potential high RBC partition, predicting potential drug toxicity and investigating mechanisms associated with RBC partitions. PMID:25746132

  13. 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 (??m). We found that the SNP induced chondrocyte apoptosis in a dose- and time-dependent manner and an observable reduction of ??m. In conclusion, our findings indicate that SNP induces apoptosis of rabbit chondrocytes via a mitochondria-mediated pathway.

  14. Polymyxin B-Induced Release of Low-Molecular-Weight, Heat-Labile Enterotoxin from Escherichia coli

    PubMed Central

    Evans, Doyle J.; Evans, Dolores G.; Gorbach, Sherwood L.

    1974-01-01

    Polymyxin B-induced release of enterotoxin from Escherichia coli strain H-10407 was demonstrated. Incubation of E. coli cells derived from 6-h cultures with polymyxin caused the rapid release of enterotoxin with a molecular weight of approximately 20,000, as estimated by the gel filtration technique. The rapidity of the release of enterotoxin indicates that it probably resides in the periplasmic space of the cell. The low-molecular-weight enterotoxin possessed vascular permeability factor and diarrheagenic activities, both of which were found to be heat-labile. The permeability factor activity of this enterotoxin was neutralized by antisera prepared against crude E. coli enterotoxin, Vibrio cholerae enterotoxin (choleragen), and V. cholerae toxoid (choleragenoid), respectively. Supernatant fluids of 6-h E. coli cultures did not contain this molecular form of enterotoxin but did contain very high-molecular-weight, heat-labile enterotoxin. Incubation of cells derived from older (18 h) cultures with polymyxin caused the release of both low- (20,000) and high-molecular-weight forms of enterotoxin. We concluded that either the 20,000-dalton form of heat-labile enterotoxin is not released by E. coli under in vitro growth conditions or that enterotoxin released in this form is rapidly destroyed or inactivated. PMID:16558081

  15. NF-?B-induced microRNA-31 promotes epidermal hyperplasia by repressing protein phosphatase 6 in psoriasis

    PubMed Central

    Yan, Sha; Xu, Zhenyao; Lou, Fangzhou; Zhang, Lingyun; Ke, Fang; Bai, Jing; Liu, Zhaoyuan; Liu, Jinlin; Wang, Hong; Zhu, Huiyuan; Sun, Yang; Cai, Wei; Gao, Yuanyuan; Su, Bing; Li, Qun; Yang, Xiao; Yu, Jianxiu; Lai, Yuping; Yu, Xue-Zhong; Zheng, Yan; Shen, Nan; Chin, Y. Eugene; Wang, Honglin

    2015-01-01

    NF-?B is constitutively activated in psoriatic epidermis. However, how activated NF-?B promotes keratinocyte hyperproliferation in psoriasis is largely unknown. Here we report that the NF-?B activation triggered by inflammatory cytokines induces the transcription of microRNA (miRNA) miR-31, one of the most dynamic miRNAs identified in the skin of psoriatic patients and mouse models. The genetic deficiency of miR-31 in keratinocytes inhibits their hyperproliferation, decreases acanthosis and reduces the disease severity in psoriasis mouse models. Furthermore, protein phosphatase 6 (ppp6c), a negative regulator that restricts the G1 to S phase progression, is diminished in human psoriatic epidermis and is directly targeted by miR-31. The inhibition of ppp6c is functionally important for miR-31-mediated biological effects. Moreover, NF-?B activation inhibits ppp6c expression directly through the induction of miR-31, and enhances keratinocyte proliferation. Thus, our data identify NF-?B-induced miR-31 and its target, ppp6c, as critical factors for the hyperproliferation of epidermis in psoriasis. PMID:26138368

  16. Lipid Metabolism, Apoptosis and Cancer Therapy

    PubMed Central

    Huang, Chunfa; Freter, Carl

    2015-01-01

    Lipid metabolism is regulated by multiple signaling pathways, and generates a variety of bioactive lipid molecules. These bioactive lipid molecules known as signaling molecules, such as fatty acid, eicosanoids, diacylglycerol, phosphatidic acid, lysophophatidic acid, ceramide, sphingosine, sphingosine-1-phosphate, phosphatidylinositol-3 phosphate, and cholesterol, are involved in the activation or regulation of different signaling pathways. Lipid metabolism participates in the regulation of many cellular processes such as cell growth, proliferation, differentiation, survival, apoptosis, inflammation, motility, membrane homeostasis, chemotherapy response, and drug resistance. Bioactive lipid molecules promote apoptosis via the intrinsic pathway by modulating mitochondrial membrane permeability and activating different enzymes including caspases. In this review, we discuss recent data in the fields of lipid metabolism, lipid-mediated apoptosis, and cancer therapy. In conclusion, understanding the underlying molecular mechanism of lipid metabolism and the function of different lipid molecules could provide the basis for cancer cell death rationale, discover novel and potential targets, and develop new anticancer drugs for cancer therapy. PMID:25561239

  17. Apoptosis: role in myeloid cell development

    PubMed Central

    Sarvothaman, Shilpa; Undi, Ram Babu; Pasupuleti, Satya Ratan; Gutti, Usha

    2015-01-01

    Hematopoiesis is the process that generates blood cells in an organism from the pluripotent stem cells. Hematopoietic stem cells are characterized by their ability to undergo self-renewal and differentiation. The self-renewing ability ensures that these pluripotent cells are not depleted from the bone marrow niche. A proper balance between cell death and cell survival is necessary to maintain a homeostatic condition, hence, apoptosis, or programmed cell death, is an essential step in hematopoiesis. Recent studies, however, have introduced a new aspect to this process, citing the significance of the apoptosis mediator, caspase, in cell development and differentiation. Extensive research has been carried out to study the possible role of caspases and other apoptosis related factors in the developmental processes. This review focuses on the various apoptotic factors involved in the development and differentiation of myeloid lineage cells: erythrocytes, megakaryocytes, and macrophages. PMID:26157776

  18. Apoptosis and Necrosis in the Liver

    PubMed Central

    Guicciardi, Maria Eugenia; Malhi, Harmeet; Mott, Justin L.; Gores, Gregory J.

    2013-01-01

    Because of its unique function and anatomical location, the liver is exposed to a multitude of toxins and xenobiotics, including medications and alcohol, as well as to infection by hepatotropic viruses, and therefore, is highly susceptible to tissue injury. Cell death in the liver occurs mainly by apoptosis or necrosis, with apoptosis also being the physiologic route to eliminate damaged or infected cells and to maintain tissue homeostasis. Liver cells, especially hepatocytes and cholangiocytes, are particularly susceptible to death receptor-mediated apoptosis, given the ubiquitous expression of the death receptors in the organ. In a quite unique way, death receptor-induced apoptosis in these cells is mediated by both mitochondrial and lysosomal permeabilization. Signaling between the endoplasmic reticulum and the mitochondria promotes hepatocyte apoptosis in response to excessive free fatty acid generation during the metabolic syndrome. These cell death pathways are partially regulated by microRNAs. Necrosis in the liver is generally associated with acute injury (i.e., ischemia/reperfusion injury) and has been long considered an unregulated process. Recently, a new form of “programmed” necrosis (named necroptosis) has been described: the role of necroptosis in the liver has yet to be explored. However, the minimal expression of a key player in this process in the liver suggests this form of cell death may be uncommon in liver diseases. Because apoptosis is a key feature of so many diseases of the liver, therapeutic modulation of liver cell death holds promise. An updated overview of these concepts is given in this article. PMID:23720337

  19. [Contribution of ethanol in apoptosis induction].

    PubMed

    Ok?ota, Magdalena; Niemcunowicz-Janica, Anna; Za?uski, Janusz; Ptaszy?ska-Sarosiek, Iwona

    2009-01-01

    Ethanol is the most common and widespread protoplasmatic poison. The destruction of cells and tissues occurs in both addicted and nonaddicted individuals, who use alcohol occasionally or temporarily. Apoptosis constitutes a very crucial factor in the pathogenesis of acute alcohol poisoning and chronic addiction. Ethanol and its metabolites induce suicidal cell death in crucial internal organs. However, despite extensive research on the role of alcohol and its metabolites in programmed cell death induction, the problem continues to be widely discussed and has no unambiguous explanation. The aim of this study is to present a review of up-to-date literature addressing the inducing influence of alcohol in apoptosis. PMID:20441086

  20. Effect of SPE-like Proton or Photon Radiation on the Kinetics of Mouse Peripheral Blood Cells and Radiation Biological Effectiveness Determinations

    PubMed Central

    Romero-Weaver, A.L.; Wan, X.S.; Diffenderfer, E.S.; Lin, L.

    2013-01-01

    Abstract Exploration missions outside low-Earth orbit are being planned; therefore, it is critical to understand the risk astronauts would be exposed to in the space environment, especially during extravehicular activities (EVAs). Reductions in white blood cell (WBC) numbers can occur as a result of exposure to solar particle event (SPE) radiation. The aim of the present study was to determine the duration of the effects on blood cell numbers from exposure to a single whole-body dose of SPE-like proton radiation or photon radiation as well as to determine the radiation biological effectiveness (RBE) values at those times when radiation exposure causes blood cell numbers to experience the most critical effects when using mice as a model. Our results indicate that both types of radiation cause significant reductions in the numbers of all blood cell types at different times post-irradiation. The RBE values were not significantly different from 1.0. These results indicate that the risk estimations for astronauts from exposure of mice to SPE-like proton radiation are comparable to those previously made for doses of standard reference radiations, suggesting that countermeasures should be developed for the decreases in blood cell counts observed following the exposure of mice to SPE radiation. Key Words: Proton radiation—Gamma radiation—Blood cell counts—Solar particle event. Astrobiology 13, 570–577. PMID:23980767

  1. Ultrahigh and High Resolution Structures and Mutational Analysis of Monomeric Streptococcus pyogenes SpeB Reveal a Functional Role for the Glycine-rich C-terminal Loop

    SciTech Connect

    González-Páez, Gonzalo E.; Wolan, Dennis W.

    2012-09-05

    Cysteine protease SpeB is secreted from Streptococcus pyogenes and has been studied as a potential virulence factor since its identification almost 70 years ago. Here, we report the crystal structures of apo mature SpeB to 1.06 {angstrom} resolution as well as complexes with the general cysteine protease inhibitor trans-epoxysuccinyl-L-leucylamido(4-guanidino)butane and a novel substrate mimetic peptide inhibitor. These structures uncover conformational changes associated with maturation of SpeB from the inactive zymogen to its active form and identify the residues required for substrate binding. With the use of a newly developed fluorogenic tripeptide substrate to measure SpeB activity, we determined IC{sub 50} values for trans-epoxysuccinyl-L-leucylamido(4-guanidino)butane and our new peptide inhibitor and the effects of mutations within the C-terminal active site loop. The structures and mutational analysis suggest that the conformational movements of the glycine-rich C-terminal loop are important for the recognition and recruitment of biological substrates and release of hydrolyzed products.

  2. Copyright 2006, Society of Petroleum Engineers This paper was prepared for presentation at the 2006 SPE Eastern Regional Meeting held in

    E-print Network

    Mohaghegh, Shahab

    . The software developed in parallel with this selection methodology includes an easy to use interface job and hence identified by the methodology presented in this paper. The software application for presentation by an SPE Program Committee following review of information contained in an abstract submitted

  3. Copyright 1998, Society of Petroleum Engineers Inc. This paper was prepared for presentation at the 1998 SPE Eastern Regional Meeting held in

    E-print Network

    Mohaghegh, Shahab

    stimulation combination of the candidate wells. A software tool based on this methodology has been developed for presentation by an SPE Program Committee following review of information contained in an abstract submitted The methodology developed in this study uses several artificial neural networks and genetic algorithm routines

  4. Copyright 2007, Society of Petroleum Engineers This paper was prepared for presentation at the SPE Europec/EAGE Annual Conference and

    E-print Network

    Copyright 2007, Society of Petroleum Engineers This paper was prepared for presentation at the SPE by the Society of Petroleum Engineers and are subject to correction by the author(s). The material, as presented, does not necessarily reflect any position of the Society of Petroleum Engineers, its officers

  5. CO2-Brine Surface Dissolution and Injection: CO2 Storage Enhancement Paul Emeka Eke, SPE, Mark Naylor, Stuart Haszeldine and Andrew Curtis, Scottish Centre for Carbon Storage,

    E-print Network

    & Exhibition held in Aberdeen, UK, 8­11 September 2009. This paper was selected for presentation by an SPE are population increase, per capita GDP (also known as ``affluence level''), the energy intensity of the economy make-up of the economy (i.e., how much energy-intensive industry is present), climate effects (i

  6. This paper was prepared for presentation at the 2005 SPE Technical Symposium of Saudi Arabia Section held in Dhahran, Saudi Arabia, 14-16 May 2005.

    E-print Network

    Al-Majed, Abdulaziz Abdullah

    This paper was prepared for presentation at the 2005 SPE Technical Symposium of Saudi Arabia Section held in Dhahran, Saudi Arabia, 14-16 May 2005. This paper was selected for presentation by the author(s). Contents of the paper, as presented, have not been reviewed by the Society of Petroleum

  7. Copyright 2000, Society of Petroleum Engineers Inc. This paper was prepared for presentation at the 2000 SPE/DOE Improved Oil Recovery

    E-print Network

    Patzek, Tadeusz W.

    Copyright 2000, Society of Petroleum Engineers Inc. This paper was prepared for presentation at the 2000 SPE/DOE Improved Oil Recovery Symposium held in Tulsa, Oklahoma, 3­5 April 2000. This paper by the Society of Petroleum Engineers and are subject to correction by the author(s). The material, as presented

  8. Physics-based Reconstruction of Sedimentary Rocks Guodong Jin, UC Berkeley; Tad W. Patzek, SPE, UC Berkeley / Lawrence Berkeley National Laboratory; and Dmitry B. Silin,

    E-print Network

    Patzek, Tadeusz W.

    SPE 83587 Physics-based Reconstruction of Sedimentary Rocks Guodong Jin, UC Berkeley; Tad W. Patzek that reconstructs nu- merically the geometrical structure and mechanical prop- erties of natural sedimentary rocks and compaction, and the diagenetic rock transformations; and (2) it reproduces the mechani- cal rock properties

  9. Development of an ultra fast online-solid phase extraction (SPE) liquid chromatography electrospray tandem mass spectrometry (LC-ESI-MS/MS)

    E-print Network

    Hammock, Bruce D.

    Development of an ultra fast online-solid phase extraction (SPE) liquid chromatography electrospray tandem mass spectrometry (LC-ESI-MS/MS) based approach for the determination of drugs in pharmacokinetic number of samples for pharmacokinetic (PK) studies are essential in drug development. Analysis of drug

  10. spe425-01 page 1 Stein, S., 2007, Approaches to continental intraplate earthquake issues, in Stein, S., and Mazzotti, S., ed., Continental Intraplate Earthquakes: Science, Hazard, and

    E-print Network

    Stein, Seth

    spe425-01 page 1 1 Stein, S., 2007, Approaches to continental intraplate earthquake issues, in Stein, S., and Mazzotti, S., ed., Continental Intraplate Earthquakes: Science, Hazard, and Policy Issues. The Geological Society of America Special Paper 425 2007 Approaches to continental intraplate earthquake issues

  11. Development and Application of a Novel SPE-Method for Bioassay-Guided Fractionation of Marine Extracts

    PubMed Central

    Cutignano, Adele; Nuzzo, Genoveffa; Ianora, Adrianna; Luongo, Elvira; Romano, Giovanna; Gallo, Carmela; Sansone, Clementina; Aprea, Susanna; Mancini, Francesca; D’Oro, Ugo; Fontana, Angelo

    2015-01-01

    The biological diversity of marine habitats is a unique source of chemical compounds with potential use as pharmaceuticals, cosmetics and dietary supplements. However, biological screening and chemical analysis of marine extracts pose specific technical constraints and require adequate sample preparation. Here we report an improved method on Solid Phase Extraction (SPE) to fractionate organic extracts containing high concentration of salt that hampers the recovery of secondary metabolites. The procedure uses a water suspension to load the extracts on a poly(styrene-divynylbenzene)-based support and a stepwise organic solvent elution to effectively desalt and fractionate the organic components. The novel protocol has been tested on MeOH-soluble material from three model organisms (Reniera sarai, Dendrilla membranosa and Amphidinium carterae) and was validated on a small panel of 47 marine samples, including sponges and protists, within discovery programs for identification of immuno-stimulatory and anti-infective natural products. PMID:26378547

  12. Development and Application of a Novel SPE-Method for Bioassay-Guided Fractionation of Marine Extracts.

    PubMed

    Cutignano, Adele; Nuzzo, Genoveffa; Ianora, Adrianna; Luongo, Elvira; Romano, Giovanna; Gallo, Carmela; Sansone, Clementina; Aprea, Susanna; Mancini, Francesca; D'Oro, Ugo; Fontana, Angelo

    2015-09-01

    The biological diversity of marine habitats is a unique source of chemical compounds with potential use as pharmaceuticals, cosmetics and dietary supplements. However, biological screening and chemical analysis of marine extracts pose specific technical constraints and require adequate sample preparation. Here we report an improved method on Solid Phase Extraction (SPE) to fractionate organic extracts containing high concentration of salt that hampers the recovery of secondary metabolites. The procedure uses a water suspension to load the extracts on a poly(styrene-divynylbenzene)-based support and a stepwise organic solvent elution to effectively desalt and fractionate the organic components. The novel protocol has been tested on MeOH-soluble material from three model organisms (Reniera sarai, Dendrilla membranosa and Amphidinium carterae) and was validated on a small panel of 47 marine samples, including sponges and protists, within discovery programs for identification of immuno-stimulatory and anti-infective natural products. PMID:26378547

  13. Seismic source functions from free-field ground motions recorded on SPE: Implications for source models of small, shallow explosions

    NASA Astrophysics Data System (ADS)

    Rougier, Esteban; Patton, Howard J.

    2015-05-01

    Reduced displacement potentials (RDPs) for chemical explosions of the Source Physics Experiments (SPE) in granite at the Nevada Nuclear Security Site are estimated from free-field ground motion recordings. Far-field P wave source functions are proportional to the time derivative of RDPs. Frequency domain comparisons between measured source functions and model predictions show that high-frequency amplitudes roll off as ?- 2, but models fail to predict the observed seismic moment, corner frequency, and spectral overshoot. All three features are fit satisfactorily for the SPE-2 test after cavity radius Rc is reduced by 12%, elastic radius is reduced by 58%, and peak-to-static pressure ratio on the elastic radius is increased by 100%, all with respect to the Mueller-Murphy model modified with the Denny-Johnson Rc scaling law. A large discrepancy is found between the cavity volume inferred from RDPs and the volume estimated from laser scans of the emplacement hole. The measurements imply a scaled Rc of ~5 m/kt1/3, more than a factor of 2 smaller than nuclear explosions. Less than 25% of the seismic moment can be attributed to cavity formation. A breakdown of the incompressibility assumption due to shear dilatancy of the source medium around the cavity is the likely explanation. New formulas are developed for volume changes due to medium bulking (or compaction). A 0.04% decrease of average density inside the elastic radius accounts for the missing volumetric moment. Assuming incompressibility, established Rc scaling laws predicted the moment reasonable well, but it was only fortuitous because dilation of the source medium compensated for the small cavity volume.

  14. NIK promotes tissue destruction independently of the alternative NF-?B pathway through TNFR1/RIP1-induced apoptosis.

    PubMed

    Boutaffala, L; Bertrand, M J M; Remouchamps, C; Seleznik, G; Reisinger, F; Janas, M; Bénézech, C; Fernandes, M T; Marchetti, S; Mair, F; Ganeff, C; Hupalowska, A; Ricci, J-E; Becher, B; Piette, J; Knolle, P; Caamano, J; Vandenabeele, P; Heikenwalder, M; Dejardin, E

    2015-12-01

    NF-?B-inducing kinase (NIK) is well-known for its role in promoting p100/NF-?B2 processing into p52, a process defined as the alternative, or non-canonical, NF-?B pathway. Here we reveal an unexpected new role of NIK in TNFR1-mediated RIP1-dependent apoptosis, a consequence of TNFR1 activation observed in c-IAP1/2-depleted conditions. We show that NIK stabilization, obtained by activation of the non-death TNFRs Fn14 or LT?R, is required for TNF?-mediated apoptosis. These apoptotic stimuli trigger the depletion of c-IAP1/2, the phosphorylation of RIP1 and the RIP1 kinase-dependent assembly of the RIP1/FADD/caspase-8 complex. In the absence of NIK, the phosphorylation of RIP1 and the formation of RIP1/FADD/caspase-8 complex are compromised while c-IAP1/2 depletion is unaffected. In vitro kinase assays revealed that recombinant RIP1 is a bona fide substrate of NIK. In vivo, we demonstrated the requirement of NIK pro-death function, but not the processing of its substrate p100 into p52, in a mouse model of TNFR1/LT?R-induced thymus involution. In addition, we also highlight a role for NIK in hepatocyte apoptosis in a mouse model of virus-induced TNFR1/RIP1-dependent liver damage. We conclude that NIK not only contributes to lymphoid organogenesis, inflammation and cell survival but also to TNFR1/RIP1-dependent cell death independently of the alternative NF-?B pathway. PMID:26045047

  15. Apoptosis. The role of the endonuclease.

    PubMed Central

    Arends, M. J.; Morris, R. G.; Wyllie, A. H.

    1990-01-01

    Cell death by apoptosis mediates several important physiologic and pathologic processes and appears to be intrinsically programmed. Its characteristic features are distinctive morphologic changes of nucleus and cytoplasm, along with cleavage of chromatin at regularly spaced sites. Here we study DNA organization and nuclear structure in apoptotic thymocytes to define the cleavage event and, by implication, the role of the responsible endonuclease. We show that in apoptosis, double-stranded cleavage of DNA generates two classes of chromatin fragments: 70% of DNA exists as long, H1-rich oligonucleosomes bound to the nucleus, and 30% comprises short oligonucleosomes and mononucleosomes, which are depleted in H1, enriched in HMG1 and 2, and not attached to the nucleus. This minority class probably derives from chromatin in a transcriptionally active configuration, which would allow better access to enzymes in the nucleoplasm, producing more complete digestion. The characteristic nucleolar morphology in apoptosis can also be explained in terms of cleavage of the transcriptionally active ribosomal genes, with conservation of the nucleolin-rich fibrillar center. The chromatin cleavage, nucleolar morphologic changes, and chromatin condensation were closely mimicked by micrococcal nuclease digestion of normal thymocyte nuclei in the presence of protease inhibitors. Thus, in apoptosis, selective activation of an endogenous endonuclease appears to be responsible not only for widespread chromatin cleavage but also for the major nuclear morphologic changes. Images Figure 2 Figure 4 Figure 5 Figure 6 Figure 7 Figure 6 Figure 8 Figure 9 Figure 10 PMID:2156431

  16. Oligodendroglial degeneration in distemper: apoptosis or necrosis?

    PubMed

    Schobesberger, M; Zurbriggen, A; Summerfield, A; Vandevelde, M; Griot, C

    1999-03-01

    Canine distemper virus (CDV) causes a multifocal demyelinating disease in dogs. It was previously shown that the initial demyelinating lesions are directly virus induced since a correlation between the occurrence of demyelination and CDV replication in white matter cells was observed. During the course of infection oligodendrocytes undergo distinct morphological alterations, partly due to a restricted CDV infection of these cells, and eventually disappear from the lesions. This phenomenon has been described in vivo as well as in vitro. However, the reason for the morphological alterations and the following oligodendroglial depletion remained unclear. Since virus infection can induce cell death, it was investigated whether apoptosis or necrosis plays a role in the pathogenesis of demyelination in canine distemper. In brain tissue sections from dogs with acute distemper apoptotic cells were not detected within the demyelinating lesions using morphological and biochemical cell death criteria. In chronic distemper, apoptotic cells - presumably inflammatory cells - were seen within the perivascular cuffs. These in vivo findings were correlated to the in vitro situation using CDV-infected primary dog brain cell cultures as well as Vero cells. Infection with culture-adapted CDV lead to massive necrosis but not to apoptosis. After infection with virulent CDV neither apoptosis nor necrosis was a predominant feature in either culture system. These findings suggest that virus-induced demyelination in canine distemper is not the direct consequence of apoptosis or necrosis. It is speculated that another mechanism must be responsible for the observed morphological alterations of oligodendrocytes, ultimately leading to demyelination. PMID:10090676

  17. A novel method for detection of apoptosis

    SciTech Connect

    Zagariya, Alexander M.

    2012-04-15

    There are two different Angiotensin II (ANG II) peptides in nature: Human type (ANG II) and Bovine type (ANG II*). These eight amino acid peptides differ only at position 5 where Valine is replaced by Isoleucine in the Bovine type. They are present in all species studied so far. These amino acids are different by only one atom of carbon. This difference is so small, that it will allow any of ANG II, Bovine or Human antibodies to interact with all species and create a universal method for apoptosis detection. ANG II concentrations are found at substantially higher levels in apoptotic, compared to non-apoptotic, tissues. ANG II accumulation can lead to DNA damage, mutations, carcinogenesis and cell death. We demonstrate that Bovine antiserum can be used for universal detection of apoptosis. In 2010, the worldwide market for apoptosis detection reached the $20 billion mark and significantly increases each year. Most commercially available methods are related to Annexin V and TUNNEL. Our new method based on ANG II is more widely known to physicians and scientists compared to previously used methods. Our approach offers a novel alternative for assessing apoptosis activity with enhanced sensitivity, at a lower cost and ease of use.

  18. RESEARCH ARTICLE Iridovirus CARD Protein Inhibits Apoptosis

    E-print Network

    Gray, Matthew

    inhibited in cells expressing GIV-CARD. HeLa cells irradiated with UV or treated with anti-Fas antibody-expression of re- combinant GIV-CARD protein in HeLa cells inhibited apoptosis induced by mitochondrial and death receptor signaling. Finally, we report that expression of GIV-CARD in HeLa cells significantly reduced

  19. The modulation of apoptosis by oncogenic viruses

    PubMed Central

    2013-01-01

    Transforming viruses can change a normal cell into a cancer cell during their normal life cycle. Persistent infections with these viruses have been recognized to cause some types of cancer. These viruses have been implicated in the modulation of various biological processes, such as proliferation, differentiation and apoptosis. The study of infections caused by oncogenic viruses had helped in our understanding of several mechanisms that regulate cell growth, as well as the molecular alterations leading to cancer. Therefore, transforming viruses provide models of study that have enabled the advances in cancer research. Viruses with transforming abilities, include different members of the Human Papillomavirus (HPV) family, Hepatitis C virus (HCV), Human T-cell Leukemia virus (HTLV-1), Epstein Barr virus (EBV) and Kaposi’s Sarcoma Herpesvirus (KSHV). Apoptosis, or programmed cell death, is a tightly regulated process that plays an important role in development and homeostasis. Additionally, it functions as an antiviral defense mechanism. The deregulation of apoptosis has been implicated in the etiology of diverse diseases, including cancer. Oncogenic viruses employ different mechanisms to inhibit the apoptotic process, allowing the propagation of infected and damaged cells. During this process, some viral proteins are able to evade the immune system, while others can directly interact with the caspases involved in apoptotic signaling. In some instances, viral proteins can also promote apoptosis, which may be necessary for an accurate regulation of the initial stages of infection. PMID:23741982

  20. The apoptosis database , A Godzik1

    E-print Network

    Bourne, Philip E.

    ; relational data- base; bioinformatics; homology; protein families; protein do- mains; domain classificationReview The apoptosis database KS Doctor1 , JC Reed1 , A Godzik1 and PE Bourne*,1,2 1 The Burnham: PE Bourne, Tel: 858-534-8301; Fax: 858-822-0873, E-mail: bourne@sdsc.edu Received 10.9.02; revised 3

  1. Measuring apoptosis in mammals in vivo.

    PubMed

    Newbold, Andrea; Martin, Ben P; Cullinane, Carleen; Bots, Michael

    2014-11-01

    Apoptosis is a mode of cell death that is essential in multicellular organisms for the removal of superfluous, damaged, or potentially dangerous cells during development, infection, or normal tissue homeostasis. To prevent inflammation, cells undergoing apoptosis produce "find-me" signals that trigger the recruitment of phagocytes, which clear the apoptotic cells on recognition of "eat-me" signals. Despite the loss of billions of cells per day by apoptosis in the human body, the number of apoptotic cells found in healthy tissue is surprisingly low and reflects the efficiency of this process. However, in certain conditions (e.g., in cancer cells responding to chemotherapy), the number of apoptotic cells is too high to be efficiently cleared by phagocytes, and apoptotic cells can be observed. In these situations, the detection of apoptosis may be helpful in monitoring disease progression as well as in predicting the responses of tumors to anticancer therapies. Here we introduce various methods for monitoring apoptotic cells in vivo using a murine model of B-cell lymphoma and a solid tumor xenograft. PMID:25368316

  2. Role of apoptosis in ventricular remodeling.

    PubMed

    Chandrashekhar, Y

    2005-03-01

    Cell loss is a common feature in the failing heart, and this contributes to the relentless progression seen in patients with heart failure. Apoptosis is one of the most common causes of cell loss in animals and humans with heart failure. There is increasing evidence that apoptosis, even while occurring in a low-grade manner, can mediate heart failure. Moreover, inhibiting apoptosis successfully prevents or attenuates heart failure in several animal models. More importantly, apoptosis is one of the few mechanisms that can be easily modulated using pharmacologic or gene therapy approaches. Animal data, obtained in the past few years, have proven the feasibility and success of this approach toward altering the natural history of heart failure. Human studies are pending, but a number of issues such as the type of inhibitor and its optimum timing/dose will need to be resolved before this becomes a reality. Nevertheless, these data will accrue over time, and anti-apoptotic therapy is likely to emerge as an important form of heart failure therapy. PMID:16036047

  3. UV-B-Induced CPD Photolyase Gene Expression is Regulated by UVR8-Dependent and -Independent Pathways in Arabidopsis.

    PubMed

    Li, Nan; Teranishi, Mika; Yamaguchi, Hiroko; Matsushita, Tomonao; Watahiki, Masaaki K; Tsuge, Tomohiko; Li, Shao-Shan; Hidema, Jun

    2015-10-01

    Plants have evolved various mechanisms that protect against the harmful effects of UV-B radiation (280-315 nm) on growth and development. Cyclobutane pyrimidine dimer (CPD) photolyase, the repair enzyme for UV-B-induced CPDs, is essential for protecting cells from UV-B radiation. Expression of the CPD photolyase gene (PHR) is controlled by light with various wavelengths including UV-B, but the mechanisms of this regulation remain poorly understood. In this study, we investigated the regulation of PHR expression by light with various wavelengths, in particular low-fluence UV-B radiation (280 nm, 0.2 µmol m(-2) s(-1)), in Arabidopsis thaliana seedlings grown under light-dark cycles for 7 d and then adapted to the dark for 3 d. Low-fluence UV-B radiation induced CPDs but not reactive oxygen species. AtPHR expression was effectively induced by UV-B, UV-A (375 nm) and blue light. Expression induced by UV-A and blue light was predominantly regulated by the cryptochrome-dependent pathway, whereas phytochromes A and B played a minor but noticeable role. Expression induced by UV-B was predominantly regulated by the UVR8-dependent pathway. AtPHR expression was also mediated by a UVR8-independent pathway, which is correlated with CPD accumulation induced by UV-B radiation. These results indicate that Arabidopsis has evolved diverse mechanisms to regulate CPD photolyase expression by multiple photoreceptor signaling pathways, including UVR8-dependent and -independent pathways, as protection against harmful effects of UV-B radiation. PMID:26272552

  4. Deleterious effect of serum proteins on the amphotericin B-induced potentiation of cisplatin in human colon cancer cells.

    PubMed Central

    Assem, M.; Bonvalot, S.; Beltramo, J. L.; Garrido, C.; Dimanche-Boitrel, M. T.; Genne, P.; Rebibou, J. M.; Caillot, D.; Chauffert, B.

    1994-01-01

    Inherent resistance of colon cancer cells to cis-diamminedichloroplatinum(II) (CDDP) is partly attributed to reduced drug penetration through plasma membrane. Amphotericin B (AmB), a polyene antifungal antibiotic, has been shown to increase CDDP penetration and cytotoxicity on several non-digestive cancer cell lines. We demonstrated here that AmB dramatically increases the penetration of CDDP, and to a lesser extent that of carboplatin (Carbo-P) and oxaloplatin (L-OHP), in the primary resistant HT 29 human colon cancer cells when drug incubation is performed in serum-free medium. The cytotoxicity of CDDP but not that of Carbo-P and L-OHP was increased by AmB. However, AmB-induced potentiation of CDDP penetration and toxicity was almost completely abolished when cell incubation was performed in presence of human serum. We investigated whether the dilution of human serum by a high osmotic power gelatine solution (Lomol) could restore the positive effect of AmB on CDDP accumulation in HT 29 cells. Incubation of cells with CDDP and AmB in pure Lomol resulted in a 6-fold increase in platinum cellular content. However, addition of serum (25%) in Lomol solution reduced to only 2-fold the increase in platinum cellular content provoked by AmB. These disappointing results show that AmB is probably uninteresting as a modulator of CDDP resistance in clinical practice. The use of haemodilution to restore the positive AmB effect on platinum cellular accumulation cannot be warranted. PMID:7917908

  5. Deleterious effect of serum proteins on the amphotericin B-induced potentiation of cisplatin in human colon cancer cells.

    PubMed

    Assem, M; Bonvalot, S; Beltramo, J L; Garrido, C; Dimanche-Boitrel, M T; Genne, P; Rebibou, J M; Caillot, D; Chauffert, B

    1994-10-01

    Inherent resistance of colon cancer cells to cis-diamminedichloroplatinum(II) (CDDP) is partly attributed to reduced drug penetration through plasma membrane. Amphotericin B (AmB), a polyene antifungal antibiotic, has been shown to increase CDDP penetration and cytotoxicity on several non-digestive cancer cell lines. We demonstrated here that AmB dramatically increases the penetration of CDDP, and to a lesser extent that of carboplatin (Carbo-P) and oxaloplatin (L-OHP), in the primary resistant HT 29 human colon cancer cells when drug incubation is performed in serum-free medium. The cytotoxicity of CDDP but not that of Carbo-P and L-OHP was increased by AmB. However, AmB-induced potentiation of CDDP penetration and toxicity was almost completely abolished when cell incubation was performed in presence of human serum. We investigated whether the dilution of human serum by a high osmotic power gelatine solution (Lomol) could restore the positive effect of AmB on CDDP accumulation in HT 29 cells. Incubation of cells with CDDP and AmB in pure Lomol resulted in a 6-fold increase in platinum cellular content. However, addition of serum (25%) in Lomol solution reduced to only 2-fold the increase in platinum cellular content provoked by AmB. These disappointing results show that AmB is probably uninteresting as a modulator of CDDP resistance in clinical practice. The use of haemodilution to restore the positive AmB effect on platinum cellular accumulation cannot be warranted. PMID:7917908

  6. Eckol inhibits ultraviolet B-induced cell damage in human keratinocytes via a decrease in oxidative stress.

    PubMed

    Piao, Mei Jing; Lee, Nam Ho; Chae, Sungwook; Hyun, Jin Won

    2012-01-01

    In previous reports, the antioxidant effects of eckol were shown to protect cells against hydrogen peroxide- and gamma ray-induced oxidative stress. In this study, the role of eckol in protecting human skin keratinocytes (HaCaT) against UVB-induced oxidative cell damage was investigated. Also, triphlorethol-A, one of the chemical components in Ecklonia cava, and quercetin a well known antioxidant, were compared with eckol in terms of antioxidant activity based on chemical structure. Eckol decreased UVB-induced intracellular reactive oxygen species (ROS), decreased injury to cellular components resulting from UVB-induced oxidative stress, and restored cell viability. In addition, eckol reduced UVB-induced apoptosis by inhibiting the disruption of mitochondrial membranes. These results suggest that eckol protects human keratinocytes against UVB-induced oxidative stress by scavenging ROS, thereby lessening injury to cellular components. PMID:22687478

  7. Beta-irradiation used for systemic radioimmunotherapy induces apoptosis and activates apoptosis pathways in leukaemia cells.

    PubMed

    Friesen, Claudia; Lubatschofski, Annelie; Kotzerke, Jörg; Buchmann, Inga; Reske, Sven N; Debatin, Klaus-Michael

    2003-09-01

    Beta-irradiation used for systemic radioimmunotherapy (RIT) is a promising treatment approach for high-risk leukaemia and lymphoma. In bone marrow-selective radioimmunotherapy, beta-irradiation is applied using iodine-131, yttrium-90 or rhenium-188 labelled radioimmunoconjugates. However, the mechanisms by which beta-irradiation induces cell death are not understood at the molecular level. Here, we report that beta-irradiation induced apoptosis and activated apoptosis pathways in leukaemia cells depending on doses, time points and dose rates. After beta-irradiation, upregulation of CD95 ligand and CD95 receptor was detected and activation of caspases resulting in apoptosis was found. These effects were completely blocked by the broad-range caspase inhibitor zVAD-fmk. In addition, irradiation-mediated mitochondrial damage resulted in perturbation of mitochondrial membrane potential, caspase-9 activation and cytochrome c release. Bax, a death-promoting protein, was upregulated and Bcl-x(L), a death-inhibiting protein, was downregulated. We also found higher apoptosis rates and earlier activation of apoptosis pathways after gamma-irradiation in comparison to beta-irradiation at the same dose rate. Furthermore, irradiation-resistant cells were cross-resistant to CD95 and CD95-resistant cells were cross-resistant to irradiation, indicating that CD95 and irradiation used, at least in part, identical effector pathways. These findings demonstrate that beta-irradiation induces apoptosis and activates apoptosis pathways in leukaemia cells using both mitochondrial and death receptor pathways. Understanding the timing, sequence and molecular pathways of beta-irradiation-mediated apoptosis may allow rational adjustment of chemo- and radiotherapeutic strategies. PMID:12830326

  8. Pre-Shot Simulations of Far-Field Ground Motions for the Source Physics Experiment (SPE) Explosions at the Climax Stock, Nevada National Security Site

    SciTech Connect

    Rodgers, A J; Wagoner, J; Petersson, N A; Sjogreen, B

    2010-11-07

    The Source Physics Experiment (SPE) will involve a series of explosions in various geologic and emplacement conditions to validate numerical simulation methods to predict behavior of seismic wave excitation and propagation for nuclear test monitoring. The first SPE's currently underway involve explosions in the Climax Stock (granitic geology) at the Nevada National Security Site (NNSS). Detailed geologic data and published material properties for the major lithologic units of the NNSS and surrounding region were used to build three-dimensional models for seismic wave propagation simulations. The geologic structure near the SPE shot point is quite varied including granitic, carbonate, tuff and alluvium lithologies. We performed preliminary ground motion simulations for a near-source domain covering 8 km x 8 km at the surface centered on the shot point to investigate various source and propagation effects using WPP, LLNL's anelastic seismic wave finite difference code. Simulations indicate that variations in wave propagation properties of the sub-surface will generate strongly path-dependent response once the energy has left the relatively small granitic geology of the near-surface Climax Stock near the SPE shot point. Rough topography to the north and west of SPE shot point causes additional complexity in the signals including energy on the transverse components. Waves propagate much faster through the granitic and carbonate formations and slower through the tuff and alluvium. Synthetic seismograms for a pure explosion source in a 3D geologic structure show large amplitudes on transverse component. For paths to the south sampling the granite, tuff and alluvium lithologies transverse component amplitudes are as high as 50% of that on the vertical and radial components.

  9. Liquid Metering Centrifuge Sticks (LMCS): A Centrifugal Approach to Metering Known Sample Volumes for Colorimetric Solid Phase Extraction (C-SPE)

    NASA Technical Reports Server (NTRS)

    Gazda, Daniel B.; Schultz, John R.; Clarke, Mark S.

    2007-01-01

    Phase separation is one of the most significant obstacles encountered during the development of analytical methods for water quality monitoring in spacecraft environments. Removing air bubbles from water samples prior to analysis is a routine task on earth; however, in the absence of gravity, this routine task becomes extremely difficult. This paper details the development and initial ground testing of liquid metering centrifuge sticks (LMCS), devices designed to collect and meter a known volume of bubble-free water in microgravity. The LMCS uses centrifugal force to eliminate entrapped air and reproducibly meter liquid sample volumes for analysis with Colorimetric Solid Phase Extraction (C-SPE). C-SPE is a sorption-spectrophotometric platform that is being developed as a potential spacecraft water quality monitoring system. C-SPE utilizes solid phase extraction membranes impregnated with analyte-specific colorimetric reagents to concentrate and complex target analytes in spacecraft water samples. The mass of analyte extracted from the water sample is determined using diffuse reflectance (DR) data collected from the membrane surface and an analyte-specific calibration curve. The analyte concentration can then be calculated from the mass of extracted analyte and the volume of the sample analyzed. Previous flight experiments conducted in microgravity conditions aboard the NASA KC-135 aircraft demonstrated that the inability to collect and meter a known volume of water using a syringe was a limiting factor in the accuracy of C-SPE measurements. Herein, results obtained from ground based C-SPE experiments using ionic silver as a test analyte and either the LMCS or syringes for sample metering are compared to evaluate the performance of the LMCS. These results indicate very good agreement between the two sample metering methods and clearly illustrate the potential of utilizing centrifugal forces to achieve phase separation and metering of water samples in microgravity.

  10. Erythrocyte ion channels in regulation of apoptosis.

    PubMed

    Lang, Florian; Birka, Christina; Myssina, Svetlana; Lang, Karl S; Lang, Philipp A; Tanneur, Valerie; Duranton, Christophe; Wieder, Thomas; Huber, Stephan M

    2004-01-01

    Erythrocytes lack mitochondria and nuclei, key organelles in the regulation of apoptosis. Until recently, erythrocytes were thus not considered subject to this type of cell death. However, exposure of erythrocytes to the Ca2+ ionophore ionomycin was shown to induce cell shrinkage, cell membrane blebbing and breakdown of phosphatidylserine asymmetry with subsequent phosphatidylserine exposure at the cell surface, all typical features of apoptosis. Further studies revealed the participation of ion channels in the regulation of erythrocyte "apoptosis." Osmotic shock, oxidative stress and energy depletion all activate a Ca2(+)-permeable non-selective cation channel in the erythrocyte cell membrane. The subsequent increase of Ca2+ concentration stimulates a scramblase leading to breakdown of cell membrane phosphatidylserine asymmetry and activates Ca2+ sensitive K+ (Gardos) channels leading to KCl loss and (further) cell shrinkage. Phosphatidylserine exposure and cell shrinkage are blunted in the nominal absence of extracellular Ca2+, in the presence of the cation channel inhibitors amiloride or ethylisopropylamiloride, at increased extracellular K+ or in the presence of the Gardos channel inhibitors clotrimazole or charybdotoxin. Thus, increase of cytosolic Ca2+ and cellular loss of K+ participate in the triggering of erythrocyte scramblase. Nevertheless, phosphatidylserine exposure is not completely abrogated in the nominal absence of Ca2+, pointing to additional Ca2(+)-independent pathways. One of those is activation of sphingomyelinase with subsequent formation of ceramide which in turn leads to stimulation of erythrocyte scramblase. The exposure of phosphatidylserine at the extracellular face of the cell membrane stimulates phagocytes to engulf the apoptotic erythrocytes. Thus, sustained activation of the cation channels eventually leads to clearance of affected erythrocytes from peripheral blood. Erythropoietin inhibits the non-selective cation channel and thus interferes with erythrocyte "apoptosis." Susceptibility to scramblase activation is enhanced in thalassemia, sickle cell disease and glucose-6-phosphate dehydrogenase deficiency. Infection with Plasmodium falciparum leads to activation of the cation channel eventually triggering erythrocyte "apoptosis." PMID:18727242

  11. The cytotoxic cell protease granzyme B initiates apoptosis in a cell-free system by proteolytic processing and activation of the ICE/CED-3 family protease, CPP32, via a novel two-step mechanism.

    PubMed Central

    Martin, S J; Amarante-Mendes, G P; Shi, L; Chuang, T H; Casiano, C A; O'Brien, G A; Fitzgerald, P; Tan, E M; Bokoch, G M; Greenberg, A H; Green, D R

    1996-01-01

    The major mechanism of cytotoxic lymphocyte killing involves the directed release of granules containing perforin and a number of proteases onto the target cell membrane. One of these proteases, granzyme B, has an unusual substrate site preference for Asp residues, a property that it shares with members of the emerging interleukin-1beta-converting enzyme (ICE)/CED-3 family of proteases. Here we show that granzyme B is sufficient to reproduce rapidly all of the key features of apoptosis, including the degradation of several protein substrates, when introduced into Jurkat cell-free extracts. Granzyme B-induced apoptosis was neutralized by a tetrapeptide inhibitor of the ICE/CED-3 family protease, CPP32, whereas a similar inhibitor of ICE had no effect. Granzyme B was found to convert CPP32, but not ICE, to its active form by cleaving between the large and small subunits of the CPP32 proenzyme, resulting in removal of the prodomain via an autocatalytic step. The cowpox virus protein CrmA, a known inhibitor of ICE family proteases as well as granzyme B, inhibited granzyme B-mediated CPP32 processing and apoptosis. These data demonstrate that CPP32 activation is a key event during apoptosis initiated by granzyme B. Images PMID:8665848

  12. Biomarkers of Chondrocyte Apoptosis and Autophagy in Osteoarthritis

    PubMed Central

    Musumeci, Giuseppe; Castrogiovanni, Paola; Trovato, Francesca Maria; Weinberg, Annelie Martina; Al-Wasiyah, Mohammad K.; Alqahtani, Mohammed H.; Mobasheri, Ali

    2015-01-01

    Cell death with morphological and molecular features of apoptosis has been detected in osteoarthritic (OA) cartilage, which suggests a key role for chondrocyte death/survival in the pathogenesis of OA. Identification of biomarkers of chondrocyte apoptosis may facilitate the development of novel therapies that may eliminate the cause or, at least, slow down the degenerative processes in OA. The aim of this review was to explore the molecular markers and signals that induce chondrocyte apoptosis in OA. A literature search was conducted in PubMed, Scopus, Web of Science and Google Scholar using the keywords chondrocyte death, apoptosis, osteoarthritis, autophagy and biomarker. Several molecules considered to be markers of chondrocyte apoptosis will be discussed in this brief review. Molecular markers and signalling pathways associated with chondroycte apoptosis may turn out to be therapeutic targets in OA and approaches aimed at neutralizing apoptosis-inducing molecules may at least delay the progression of cartilage degeneration in OA. PMID:26334269

  13. Role of Urine Neutrophil Gelatinase-Associated Lipocalin in the Early Diagnosis of Amphotericin B-Induced Acute Kidney Injury.

    PubMed

    Rocha, Paulo Novis; Macedo, Michael Nascimento; Kobayashi, Carla Dinamérica; Moreno, Lis; Guimarães, Luiz Henrique Santos; Machado, Paulo Roberto Lima; Badaró, Roberto; Carvalho, Edgar M; Glesby, Marshall Jay

    2015-11-01

    Determination of the neutrophil gelatinase-associated lipocalin (NGAL) level can be used to detect acute kidney injury (AKI) earlier than determination of the serum creatinine (SCr) level in settings such as cardiac surgery, contrast nephropathy, and intensive care units. We hypothesized that urine NGAL (UrNGAL) would be an early biomarker of drug nephrotoxicity. To test this, we studied hemodynamically stable patients treated with amphotericin B (AmB). We measured the SCr and UrNGAL levels at the baseline and daily after initiation of AmB up to day 14 or development of AKI by the use of the SCr criterion. AKI was defined according to a Kidney Disease: Improving Global Outcomes (KDIGO) criterion (an increase in the SCr level by ?0.3 mg/dl within 48 h or an SCr level ?1.5 times the baseline level within 7 days). We studied 24 patients with a mean age of 48.4 ± 16.4 years. Most patients were male, and the patients received AmB (12 received AmB deoxycholate and 12 received liposomal AmB) for the treatment of leishmaniasis (91.7%). Overall, 17/24 patients fulfilled a KDIGO criterion for AKI. Peak UrNGAL levels were higher in patients with AKI than in patients without AKI and in recipients of AmB deoxycholate than in recipients of liposomal AmB. The diagnostic performance of the UrNGAL level on day 5 for the detection of AKI was moderate, with the area under the curve (AUC) being 0.68 (95% confidence interval [CI], 0.41 to 0.95). In the subgroup receiving AmB deoxycholate, however, the AUC rose to 0.89 (95% CI, 0.67 to 1.00). In a patient-level analysis, we found that AKI could be detected 3.2 days earlier by the use of the UrNGAL criterion than by the use of the SCr criterion (times to AKI by the UrNGAL and SCr criteria, 3.7 ± 2.5 versus 6.9 ± 3.3 days, respectively; P = 0.001). Future studies should evaluate if a treatment strategy oriented toward evaluation of UrNGAL levels will improve outcomes. These findings for AmB-induced AKI in leishmaniasis patients could serve as a basis for the investigation of urine biomarkers in the early detection of drug nephrotoxicity in other clinical settings. PMID:26303800

  14. Real-Time Data Management, IP Telemetry, Data Integration, and Data Center Operations for the Source Physics Experiment (SPE), Nevada National Security Site

    NASA Astrophysics Data System (ADS)

    Plank, G.; Slater, D.; Torrisi, J.; Presser, R.; Williams, M.; Smith, K. D.

    2012-12-01

    The Nevada Seismological Laboratory (NSL) manages time-series data and high-throughput IP telemetry for the National Center for Nuclear Security (NCNS) Source Physics Experiment (SPE), underway on the Nevada National Security Site (NNSS). During active-source experiments, SPE's heterogeneous systems record over 350 channels of a variety of data types including seismic, infrasound, acoustic, and electro-magnetic. During the interim periods, broadband and short period instruments record approximately 200 channels of continuous, high-sample-rate seismic data. Frequent changes in sensor and station configurations create a challenging meta-data environment. Meta-data account for complete operational histories, including sensor types, serial numbers, gains, sample rates, orientations, instrument responses, data-logger types etc. To date, these catalogue 217 stations, over 40 different sensor types, and over 1000 unique recording configurations (epochs). Facilities for processing, backup, and distribution of time-series data currently span four Linux servers, 60Tb of disk capacity, and two data centers. Bandwidth, physical security, and redundant power and cooling systems for acquisition, processing, and backup servers are provided by NSL's Reno data center. The Nevada System of Higher Education (NSHE) System Computer Services (SCS) in Las Vegas provides similar facilities for the distribution server. NSL staff handle setup, maintenance, and security of all data management systems. SPE PIs have remote access to meta-data, raw data, and CSS3.0 compilations, via SSL-based transfers such as rsync or secure-copy, as well as shell access for data browsing and limited processing. Meta-data are continuously updated and posted on the Las Vegas distribution server as station histories are better understood and errors are corrected. Raw time series and refined CSS3.0 data compilations with standardized formats are transferred to the Las Vegas data server as available. For better data availability and station monitoring, SPE is beginning to leverage NSL's wide-area digital IP network with nine SPE stations and six Rock Valley area stations that stream continuous recordings in real time to the NSL Reno data center. These stations, in addition to eight regional legacy stations supported by National Security Technologies (NSTec), are integrated with NSL's regional monitoring network and constrain a high-quality local earthquake catalog for NNSS. The telemetered stations provide critical capabilities for SPE, and infrastructure for earthquake response on NNSS as well as southern Nevada and the Las Vegas area.

  15. The Source Physics Experiments (SPE): A Physics-Based Approach to Discriminate Low-Yield Nuclear Events (Invited)

    NASA Astrophysics Data System (ADS)

    Snelson, C. M.; Chipman, V.; White, R. L.; Emmitt, R.; Townsend, M.

    2013-12-01

    Discriminating low-yield nuclear explosions is one of the current challenges in the field of monitoring and verification. Work is currently underway in Nevada to address this challenge by conducting a series of experiments using a physics-based approach. This has been accomplished by using a multifaceted, multi-disciplinary approach that includes a range of activities, from characterizing the shallow subsurface to acquiring new explosion data both in the near field (< 100 m from the source) to the far field (> 100 m to 10 s km from the source). The Source Physics Experiment (SPE) is a collaborative project between National Security Technologies, LLC, Lawrence Livermore National Laboratory, Los Alamos National Laboratory, Sandia National Laboratories, the Defense Threat Reduction Agency, and the Air Force Technical Applications Center. The goal of the SPE is to understand the transition of seismic energy from the near field to the far field; to understand the development of S-waves in explosives sources; and to understand how anisotropy controls seismic energy transmission and partitioning. To fully explore these problems, the SPE test series includes tests in both simple and complex geology cases. The current series is being conducted in a highly fractured granite body. This location was chosen, in part, because it was the location of previous nuclear tests in the same rock body and because generally the geology has been well characterized. In addition to historic data, high-resolution seismic reflection, cross-hole tomography, core samples, LIDAR, hyperspectral, and fracture mapping data have been acquired to further characterize and detect changes after each of the shot across the test bed. The complex geology series includes 7 planned shots using conventional explosives in the same shot hole surrounded by Continuous Reflectometry for Radius vs. Time Experiment (CORRTEX), Time of Arrival, Velocity of Detonation, down-hole accelerometers, surface accelerometers, infrasound, and a suite of seismic sensors of various frequency bands from the near field to the far field. This allows for the use of a single test bed in the granite instead of multiple test beds to obtain the same results. The shots are planned at various depths to obtain a Green's function, scaled depth-of-burial data, nominal depth-of-burial data and damage-zone data. Three shots have been executed to date and the fourth is planned for August 2013 as a 220 lb (100 kg) TNT equivalent shot at a depth of 315 ft (96 m). Over 400 data channels have been recorded on the first series of shots with high fidelity. Once the complex geology site data have been exploited, a new test bed will be developed in a simpler geology to test these physics-based models. Ultimately, the results from this project will provide the next advances in the science of monitoring to enable a physics-based predicative capability. This work was done by National Security Technologies, LLC, under Contract No. DE-AC52-06NA25946 with the U.S. Department of Energy. DOE/NV/25946--1835.

  16. Increased leucocyte apoptosis in transfused ?-thalassaemia patients

    PubMed Central

    Walter, Patrick B.; Porter, John; Evans, Patricia; Kwiatkowski, Janet L.; Neufeld, Ellis J.; Coates, Thomas; Giardina, Patricia J.; Grady, Robert W.; Vichinsky, Elliott; Olivieri, Nancy; Trachtenberg, Felicia; Alberti, Daniele; Fung, Ellen; Ames, Bruce; Higa, Annie; Harmatz, Paul

    2015-01-01

    Summary This exploratory study assessed apoptosis in peripheral blood leucocytes (PBL) from ?-thalassaemia patients receiving chronic transfusions and chelation therapy (deferasirox or deferoxamine) at baseline, 1, 6, and 12 months. At baseline, thalassaemic PBLs presented 50% greater levels of Bax (BAX), 75% higher caspase-3/7, 48% higher caspase-8 and 88% higher caspase-9 activities and 428% more nucleosomal DNA fragmentation than control subjects. Only neutrophils correlated significantly with apoptotic markers. Previously, we showed that over the treatment year, hepatic iron declined; we now show that the ratio of Bax/Bcl-2 (BCL2), (?27.3%/year), and caspase-9 activity (?13.3%/year) declined in both treatment groups, suggesting that chelation decreases body iron and indicators of PBL apoptosis. PMID:23216540

  17. Prostate Apoptosis Response 4 (Par-4), a Novel Substrate of Caspase-3 during Apoptosis Activation

    PubMed Central

    Chaudhry, Parvesh; Singh, Mohan; Parent, Sophie

    2012-01-01

    Prostate apoptosis response 4 (Par-4) is a ubiquitously expressed proapoptotic tumor suppressor protein. Here, we show for the first time, that Par-4 is a novel substrate of caspase-3 during apoptosis. We found that Par-4 is cleaved during cisplatin-induced apoptosis in human normal and cancer cell lines. Par-4 cleavage generates a C-terminal fragment of ?25 kDa, and the cleavage of Par-4 is completely inhibited by a caspase-3 inhibitor, suggesting that caspase-3 is directly involved in the cleavage of Par-4. Caspase-3-deficient MCF-7 cells do not show Par-4 cleavage in response to cisplatin treatment, and restoration of caspase-3 in MCF-7 cells produces a decrease in Par-4 levels, with the appearance of a cleaved fragment. Additionally, knockdown of Par-4 reduces caspase-3 activation and apoptosis induction. Site-directed mutagenesis reveals that Par-4 cleavage by caspase-3 occurs at an unconventional site, EEPD131?G. Interestingly, overexpression of wild-type Par-4 but not the Par-4 D131A mutant sensitizes cells to cisplatin-induced apoptosis. Upon caspase-3 cleavage, the cleaved fragment of Par-4 accumulates in the nucleus and displays increased apoptotic activity. Overexpression of the cleaved fragment of Par-4 inhibits I?B? phosphorylation and blocks NF-?B nuclear translocation. We have identified a novel specific caspase-3 cleavage site in Par-4, and the cleaved fragment of Par-4 retains proapoptotic activity. PMID:22184067

  18. Autophagy and apoptosis dysfunction in neurodegenerative disorders.

    PubMed

    Ghavami, Saeid; Shojaei, Shahla; Yeganeh, Behzad; Ande, Sudharsana R; Jangamreddy, Jaganmohan R; Mehrpour, Maryam; Christoffersson, Jonas; Chaabane, Wiem; Moghadam, Adel Rezaei; Kashani, Hessam H; Hashemi, Mohammad; Owji, Ali A; ?os, Marek J

    2014-01-01

    Autophagy and apoptosis are basic physiologic processes contributing to the maintenance of cellular homeostasis. Autophagy encompasses pathways that target long-lived cytosolic proteins and damaged organelles. It involves a sequential set of events including double membrane formation, elongation, vesicle maturation and finally delivery of the targeted materials to the lysosome. Apoptotic cell death is best described through its morphology. It is characterized by cell rounding, membrane blebbing, cytoskeletal collapse, cytoplasmic condensation, and fragmentation, nuclear pyknosis, chromatin condensation/fragmentation, and formation of membrane-enveloped apoptotic bodies, that are rapidly phagocytosed by macrophages or neighboring cells. Neurodegenerative disorders are becoming increasingly prevalent, especially in the Western societies, with larger percentage of members living to an older age. They have to be seen not only as a health problem, but since they are care-intensive, they also carry a significant economic burden. Deregulation of autophagy plays a pivotal role in the etiology and/or progress of many of these diseases. Herein, we briefly review the latest findings that indicate the involvement of autophagy in neurodegenerative diseases. We provide a brief introduction to autophagy and apoptosis pathways focusing on the role of mitochondria and lysosomes. We then briefly highlight pathophysiology of common neurodegenerative disorders like Alzheimer's diseases, Parkinson's disease, Huntington's disease and Amyotrophic lateral sclerosis. Then, we describe functions of autophagy and apoptosis in brain homeostasis, especially in the context of the aforementioned disorders. Finally, we discuss different ways that autophagy and apoptosis modulation may be employed for therapeutic intervention during the maintenance of neurodegenerative disorders. PMID:24211851

  19. Alcohol and Apoptosis: Friends or Foes?

    PubMed

    Rodriguez, Ana; Chawla, Karan; Umoh, Nsini A; Cousins, Valerie M; Ketegou, Assama; Reddy, Madhumati G; AlRubaiee, Mustafa; Haddad, Georges E; Burke, Mark W

    2015-01-01

    Alcohol abuse causes 79,000 deaths stemming from severe organ damage in the United States every year. Clinical manifestations of long-term alcohol abuse on the cardiac muscle include defective contractility with the development of dilated cardiomyopathy and low-output heart failure; which has poor prognosis with less than 25% survival for more than three years. In contrast, low alcohol consumption has been associated with reduced risk of cardiovascular disease, however the mechanism of this phenomenon remains elusive. The aim of this study was to determine the significance of apoptosis as a mediating factor in cardiac function following chronic high alcohol versus low alcohol exposure. Adult rats were provided 5 mM (low alcohol), 100 mM (high alcohol) or pair-fed non-alcohol controls for 4-5 months. The hearts were dissected, sectioned and stained with cresyl violet or immunohistochemically for caspase-3, a putative marker for apoptosis. Cardiomyocytes were isolated to determine the effects of alcohol exposure on cell contraction and relaxation. High alcohol animals displayed a marked thinning of the left ventricular wall combined with elevated caspase-3 activity and decreased contractility. In contrast, low alcohol was associated with increased contractility and decreased apoptosis suggesting an overall protective mechanism induced by low levels of alcohol exposure. PMID:26610584

  20. Alcohol and Apoptosis: Friends or Foes?

    PubMed Central

    Rodriguez, Ana; Chawla, Karan; Umoh, Nsini A.; Cousins, Valerie M.; Ketegou, Assama; Reddy, Madhumati G.; AlRubaiee, Mustafa; Haddad, Georges E.; Burke, Mark W.

    2015-01-01

    Alcohol abuse causes 79,000 deaths stemming from severe organ damage in the United States every year. Clinical manifestations of long-term alcohol abuse on the cardiac muscle include defective contractility with the development of dilated cardiomyopathy and low-output heart failure; which has poor prognosis with less than 25% survival for more than three years. In contrast, low alcohol consumption has been associated with reduced risk of cardiovascular disease, however the mechanism of this phenomenon remains elusive. The aim of this study was to determine the significance of apoptosis as a mediating factor in cardiac function following chronic high alcohol versus low alcohol exposure. Adult rats were provided 5 mM (low alcohol), 100 mM (high alcohol) or pair-fed non-alcohol controls for 4–5 months. The hearts were dissected, sectioned and stained with cresyl violet or immunohistochemically for caspase-3, a putative marker for apoptosis. Cardiomyocytes were isolated to determine the effects of alcohol exposure on cell contraction and relaxation. High alcohol animals displayed a marked thinning of the left ventricular wall combined with elevated caspase-3 activity and decreased contractility. In contrast, low alcohol was associated with increased contractility and decreased apoptosis suggesting an overall protective mechanism induced by low levels of alcohol exposure. PMID:26610584

  1. Helicobacter pylori lipopolysaccharide hinders polymorphonuclear leucocyte apoptosis.

    PubMed

    Hofman, V; Ricci, V; Mograbi, B; Brest, P; Luciano, F; Boquet, P; Rossi, B; Auberger, P; Hofman, P

    2001-03-01

    A prominent histologic feature of Helicobacter pylori infection is a dense infiltration of polymorphonuclear leukocytes (PMNL) in gastric mucosa. H. pylori lipopolysaccharide (LPS) has been recognized as a primary virulence factor evoking acute mucosal inflammatory reaction. Previous works have shown that H. pylori LPS immunologic activities are lower than those of enterobacterial LPS. However, the effect of H. pylori LPS on spontaneous PMNL apoptosis, and mechanisms by which this H. pylori LPS may promote PMNL survival remain to be established. In this study, we investigated, by both morphologic and biochemical approaches, the action of H. pylori LPS on PMNL apoptosis in vitro, using broth culture filtrates (BCF) of H. pylori strains with different genotypes. We found that BCF from H. pylori caused a significant delay in spontaneous PMNL apoptosis and this delay was independent of the VacA, cag pathogenicity island and urease status. We demonstrated that LPS in BCF is responsible for this effect because it was abrogated by the LPS antagonist B287 (a synthetic analog of Rhodobactersphaeroides lipid A). Moreover, BCF from H. pylori induced P42/44MAP kinase activation in PMNL. Similar results were obtained with BCF of an Escherichia coli strain. Taken together these data suggest that longer survival of PMNL induced by H. pylori LPS may increase gastric epithelium injury in H. pylori-associated diseases. PMID:11310830

  2. Targeting the apoptosis pathway in prostate cancer.

    PubMed

    Zielinski, Robert R; Eigl, Bernhard J; Chi, Kim N

    2013-01-01

    Important inroads have been made in the understanding and treatment of metastatic prostate cancer in recent years. However, the need for agents targeting novel pathways remains ever present. One such area with promise is through apoptosis or programmed cell death. Many perturbations within the apoptotic process have been associated with treatment resistance and progression in castration-resistant prostate cancer; thus, therapeutic potential exists with agents that can restore an effective apoptotic response to cellular stressors. This article focuses on agents in clinical development targeting apoptosis through the intrinsic and extrinsic pathways. We review the current status of agents that intervene at the Bcl2 checkpoints, humanized antibodies to death receptors, agents that target the inhibitors of apoptosis proteins, mimetics of small mitochondria-derived activator of caspases, and antisense therapies targeting cytoprotective chaperones. Although single-agent activity has been demonstrated with some of these agents, the clinical development path forward will see them coupled with standard hormonal therapy and chemotherapy. OGX-011 (custirsen), which inhibits expression of the cytoprotective chaperone protein clusterin, is the most mature of these agents and is being tested in combination with chemotherapy in phase III clinical trials for castration-resistant prostate cancer, and results are eagerly awaited. PMID:23337761

  3. Application of HPLC-DAD after SPE/QuEChERS with ZrO2-based sorbent in d-SPE clean-up step for pesticide analysis in edible oils.

    PubMed

    Tuzimski, Tomasz; Rejczak, Tomasz

    2016-01-01

    In this study, the solid-phase extraction/quick, easy, cheap, effective, rugged and safe (SPE/QuEChERS) technique was adapted to develop a simple sample treatment for multi-residue pesticide analysis of edible oils. The proposed method is based on liquid-liquid partitioning with acetonitrile followed by dispersive solid phase extraction using zirconia-coated silica particles for extract purification. To evaluate the described method, 21 pesticides belonging to different chemical classes were analysed using high performance liquid chromatography with diode-array detection (HPLC-DAD). For validation purposes, recovery studies were performed at 75 ng g(-1), 125 ng g(-1), 250 ng g(-1), 500 ng g(-1) and 1000 ng g(-1) levels. Recoveries were over the range of 50-130% for most of the analytes, with relative standard deviations less than 15% being observed. HPLC-DAD provided suitable linearity, precision and accuracy. The validated method was successfully applied to the analysis of edible oil samples selected from the market. PMID:26212943

  4. Use of diffusion-ordered NMR spectroscopy and HPLC-UV-SPE-NMR to identify undeclared synthetic drugs in medicines illegally sold as phytotherapies.

    PubMed

    Silva, Lorena M A; Filho, Elenilson G A; Thomasi, Sérgio S; Silva, Bianca F; Ferreira, Antonio G; Venâncio, Tiago

    2013-09-01

    The informal (and/or illegal) e-commerce of pharmaceutical formulations causes problems that governmental health agencies find hard to control, one of which concerns formulas sold as natural products. The purpose of this work was to explore the advantages and limitations of DOSY and HPLC-UV-SPE-NMR. These techniques were used to identify the components of a formula illegally marketed in Brazil as an herbal medicine possessing anti-inflammatory and analgesic properties. DOSY was able to detect the major components present at higher concentrations. Complete characterization was achieved using HPLC-UV-SPE-NMR, and 1D and 2D NMR analyses enabled the identification of known synthetic drugs. These were ranitidine and a mixture of orphenadrine citrate, piroxicam, and dexamethasone, which are co-formulated in a remedy called Rheumazim that is used to relieve severe pain, but it is prohibited in Brazil because of a lack of sufficient pharmacokinetic and pharmacodynamic information. PMID:23818305

  5. A rapid SPE-based analytical method for UPLC/MS/MS determination of aminoglycoside antibiotic residues in bovine milk, muscle, and kidney.

    PubMed

    Young, Michael S; van Tran, Kim; Goh, Evelyn; Shia, Jeremy C

    2014-01-01

    An SPE-based cleanup protocol was developed for ultra-performance LC (UPLC)/MS/MS determination of residues of the common aminoglycoside antibiotics streptomycin, dihydrostreptomycin, neomycin, and gentamicin in bovine milk, kidney, and muscle. Recoveries for all compounds except neomycin ranged from 80 to 104% for all matrixes studied; recoveries for neomycin ranged from 71 to 84%. Intraday and interday precision data were under 15% for all sample matrixes. Compared with other recently reported cleanup methods, less sample is required, the use of potentially dangerous reagents is minimized, and fewer manipulations are required by the analyst. A high throughput 96-well plate format was used for SPE cleanup and UPLC/MS analysis. PMID:25632452

  6. 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.

  7. CD45 regulates apoptosis in peripheral T lymphocytes.

    PubMed

    Liu, Zhe; Dawes, Ritu; Petrova, Svetla; Beverley, Peter C L; Tchilian, Elma Z

    2006-06-01

    Programmed cell death (apoptosis) is a key mechanism for regulating lymphocyte numbers. Murine lymph node lymphocytes cultured in vitro without added stimuli show significant levels of apoptosis over 24 h, detectable by staining with Annexin V. CD4 and CD8 T lymphocytes from transgenic (Tg) mice expressing single CD45RABC or CD45RO isoforms show increased apoptosis and the extent of apoptosis is inversely correlated with the level of CD45 expression. CD45 Tg cells exhibit phosphatidyl serine translocation and DNA oligonucleosome formation, and can be partially rescued from apoptosis by culture in caspase inhibitors or common gamma-chain-binding cytokines. We conclude that CD45 is an important regulator of spontaneous apoptosis in T lymphocytes and this mechanism may contribute to the disease associations reported for individuals expressing CD45 variant alleles. PMID:16621865

  8. Self-consumption: the interplay of autophagy and apoptosis

    PubMed Central

    Mariño, Guillermo; Niso-Santano, Mireia; Baehrecke, Eric H.; Kroemer, Guido

    2014-01-01

    Autophagy and apoptosis control the turnover of organelles and proteins within cells, and of cells within organisms, respectively, and many stress pathways sequentially elicit autophagy, and apoptosis within the same cell. Generally autophagy blocks the induction of apoptosis, and apoptosis-associated caspase activation shuts off the autophagic process. However, in special cases, autophagy or autophagy-relevant proteins may help to induce apoptosis or necrosis, and autophagy has been shown to degrade the cytoplasm excessively, leading to ‘autophagic cell death’. The dialogue between autophagy and cell death pathways influences the normal clearance of dying cells, as well as immune recognition of dead cell antigens. Therefore, the disruption of the relationship between autophagy and apoptosis has important pathophysiological consequences. PMID:24401948

  9. Ionic-liquid-functionalized magnetic particles as an adsorbent for the magnetic SPE of sulfonylurea herbicides in environmental water samples.

    PubMed

    He, Zeying; Liu, Donghui; Zhou, Zhiqiang; Wang, Peng

    2013-10-01

    In this paper, a new ionic-liquid-functionalized magnetic material was prepared based on the immobilization of an ionic liquid on silica magnetic particles that could be successfully used as an adsorbent for the magnetic SPE of five sulfonylurea herbicides (bensulfuron-methyl, prosulfuron, pyrazosulfuron-ethyl, chlorimuron-ethyl and triflusulfuron-methyl) from environmental water samples. The main parameters affecting the extraction efficiency such as desorption conditions, sample pH, extraction time and so on, were optimized using the Taguchi method. Good linearities were obtained with correlation coefficients ranging from 0.9992 to 0.9999 in the concentration range of 0.1-50 ?g L(-1) and the LODs were 0.053-0.091 ?g L(-1). Under the optimum conditions, the enrichment factors of the method were 1155-1380 and the recoveries ranged from 77.8 to 104.4%. The proposed method was reliable and could be applied to the residue analysis of sulfonylurea herbicides in environmental water samples (tap, reservoir and river). PMID:23894051

  10. A ?-SPE procedure for the determination of cannabinoids and their metabolites in urine by LC-MS/MS.

    PubMed

    Montesano, Camilla; Sergi, Manuel; Odoardi, Sara; Simeoni, Maria Chiara; Compagnone, Dario; Curini, Roberta

    2014-03-01

    In this paper the development and validation of a method for the analysis of THC-COOH, THC, THC-OH, CBD and CBN in their total form in urine by LC-MS/MS is presented. Tandem hydrolysis, i.e. enzymatic and basic, has been found optimal for the simultaneous analysis of the selected analytes in urine: basic hydrolysis is more effective for the cleavage of THC-COOH glucuronide while enzymatic hydrolysis allows the cleavage of the conjugated cannabinoids possessing ether bonds (THC, THC-OH, CBD). The whole procedure requires a 2h enzymatic hydrolysis using only 90?L of urine by ?-SPE extraction technique with C18 tips. Clear advantages in terms of time and of enzyme reduction are obtained and the cost of the analysis can be dramatically reduced. Satisfactory recovery values and matrix effect are obtained, and the chromatographic run, performed with a fused-core column, allowed the complete analyte separation in only 3min (total run 5.8min) with a common HPLC system. Furthermore the whole procedure has been validated according to SWGTOX guidelines: LOQs are between 6 and 10ppb, quite lower than the requested cut-off for urine testing; intermediate reproducibility of the selected analytes is below 10% and accuracy is between 85% and 113%, except for CBD, included only for semi-quantitative determination. PMID:24469020

  11. Schisandrin B inhibits cell growth and induces cellular apoptosis and autophagy in mouse hepatocytes and macrophages: implications for its hepatotoxicity

    PubMed Central

    Zhang, Yi; Zhou, Zhi-Wei; Jin, Hua; Hu, Chengbin; He, Zhi-Xu; Yu, Zhi-Ling; Ko, Kam-Ming; Yang, Tianxin; Zhang, Xueji; Pan, Si-Yuan; Zhou, Shu-Feng

    2015-01-01

    A number of drugs and herbal compounds have been documented to cause hepatoxicity. Schisandrin B (Sch B) is an active dibenzocyclooctadiene isolated from Schisandrae fructus, with a wide array of pharmacological activities. However, the potential hepatotoxicity of Sch B is a major safety concern, and the underlying mechanism for Sch B-induced liver toxic effects is not fully elucidated. In the present study, we aimed to investigate the liver toxic effects and the molecular mechanisms of Sch B in mouse liver and macrophage cells. The results have shown that Sch B exhibits potent grow inhibitory, proapoptotic, and proautophagic effects in AML-12 and RAW 264.7 cells. Sch B markedly arrested cells in G1 phase in both cell lines, accompanied by the down-regulation of cyclin dependent kinase 2 (CDK2) and cyclin D1 and up-regulation of p27 Kip1 and checkpoint kinase 1. Furthermore, Sch B markedly increased the apoptosis of AML-12 and RAW 264.7 cells with a decrease in the expression of B-cell lymphoma-extra-large and (Bcl-xl) B-cell lymphoma 2 (Bcl-2), but an increase in the expression of B-cell lymphoma 2-associated X protein (Bax). Sch B promoted the cleavage of caspase 3 and poly-adenosine diphosphate-ribose polymerase (PARP) in both cell lines. Additionally, Sch B significantly induced autophagy of AML-12 and RAW 264.7 cells. Sch B inhibited the activation of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway, as indicated by their altered phosphorylation, contributing to the proautophagic effect of Sch B. Taken together, our findings show that the inducing effects of Sch B on cell cycle arrest, apoptosis, and autophagy may contribute to its liver toxic effects, which might provide a clue for the investigation of the molecular toxic targets and underlying mechanisms for Sch B-induced hepatotoxicity in herbal consumers. More studies are warranted to fully delineate the underlying mechanisms, efficacy, and safety of Sch B for clinical use. PMID:25926716

  12. Endoplasmic reticulum stress mediates nitric oxide-induced chondrocyte apoptosis

    PubMed Central

    TAKADA, KOJI; HIROSE, JUN; YAMABE, SOICHIRO; UEHARA, YUSHUKE; MIZUTA, HIROSHI

    2013-01-01

    Nitric oxide (NO) is one of the most important mediators of chondrocyte apoptosis, which is a notable feature of cartilage degeneration. While apoptosis of chondrocytes is induced by p53, NO can also induce endoplasmic reticulum (ER) stress, which may be involved in the process of NO-induced chondrocyte apoptosis. The aims of this study were to determine whether NO-induced ER stress (ERS) leads to apoptosis of chondrocytes and to investigate the temporal relationship between the expression of C/EBP-homologous protein (CHOP), an ERS-associated apoptotic molecule, and the expression of p53 during apoptosis in NO-stimulated chondrocytes. Rat chondrocytes were stimulated by sodium nitroprusside (SNP), a NO donor. Real-time polymerase chain reaction (PCR) was performed to analyze the mRNA expression of CHOP, glucose-regulated protein (GRP78) and p53. Apoptosis of chondrocytes was quantified using an enzyme-linked immunosorbent assay (ELISA). SNP-treated chondrocytes showed an increase in CHOP and GRP78 mRNA expression and underwent apoptosis. Sodium 4-phenylbutyrate (PBA), an ERS inhibitor, reduced CHOP and GRP78, as well as SNP-stimulated apoptosis of chondrocytes, without affecting the SNP-dependent generation of NO. In addition, the blockade of CHOP following siRNA transfection reduced SNP-induced apoptosis of chondrocytes. The CHOP expression increased after apoptosis was detected in the SNP-treated chondrocytes, whereas the p53 expression increased prior to apoptosis. These data demonstrated that NO-induced ERS leads chondrocytes to apoptosis, although this effect appears to be limited to persistent impairment of NO stimulation. These findings may provide insight into the pathology of cartilage degeneration. PMID:24648941

  13. Chemopreventive Effects of Sarcotriol on Ultraviolet B-induced Skin Tumor Development in SKH-1 Hairless Mice

    PubMed Central

    Kundoor, Vipra; Zhang, Xiaoying; Bommareddy, Ajay; Khalifa, Sherief; Fahmy, Hesham; Dwivedi, Chandradhar

    2007-01-01

    Sarcotriol (ST) has been shown to be chemopreventive on 7,12-dimethyl-benz(a)anthracene (DMBA) initiated and 12-O-tetradecanoylphorbol-13-acetate (TPA)-promoted skin tumor development in CD-1 mice in recent studies from our laboratory. The objective of this study was to determine the chemopreventive effects of ST on ultraviolet B (UVB)-induced skin tumor development in female SKH-1 hairless mice, an experimental model relevant to human skin cancer development, and its possible mechanisms of action. Female SKH-1 mice were divided into two groups: Control and ST treated. Control was topically treated with 100 ?L acetone and ST treated group administered with 30 ?g ST in 100 ?L acetone one hour before UVB exposure. For UVB-induced tumorigenesis, carcinogenesis was initiated and promoted by UVB (180 mJ/cm2). Group weights and tumor counts were taken once every week. After 30 weeks, mice were sacrificed and dorsal skin samples were collected. The proteins from the skin sample were further used for SDS-PAGE and Western blotting using specific antibodies against caspase-3, caspase-8, caspase-9 and p53. Tumor multiplicity was found 19.6, 5.2 in the control and ST treated groups respectively. Caspase-3, -8, -9 and p53 were significantly (P < 0.05) upregulated in ST treated group compared to Control group. Together, this study for the first time identifies the chemopreventive effects of ST in UVB-induced carcinogenesis possibly by inducing apoptosis and upregulating p53. PMID:18463728

  14. Application of Colorimetric Solid Phase Extraction (C-SPE) to Monitoring Nickel(II) and Lead(II) in Spacecraft Water Supplies

    NASA Technical Reports Server (NTRS)

    Diaz, Neil C.; Gazda, Daniel B.; Fritz, James S.; Porter, Marc D.; Rutz, Jeff; Mudgett, Paul; Schultz, John

    2004-01-01

    Archived water samples collected on the International Space Station (ISS) and returned to Earth for analysis have, in a few instances, contained trace levels of heavy metals. Building on our previous advances using Colorimetric Solid Phase Extraction (C-SPE) as a biocide monitoring technique, we are devising methods for the low level monitoring of nickel(II), lead(II) and other heavy metals. C-SPE is a sorption-spectrophotometric platform based on the extraction of analytes onto a membrane impregnated with a colorimetric reagent that are then quantified on the surface of the membrane using a diffuse reflectance spectrophotometer. Along these lines, we have determined nickel(II) via complexation with dimethylglyoxime (DMG) and begun to examine the analysis of lead(II) by its reaction with 2,5- dimercapto-1,3,4-thiadiazole (DMTD) and 4-(2- pyridylazo)-resorcinol (PAR). These developments are also extending a new variant of C-SPE in which immobilized reagents are being incorporated into this methodology in order to optimize sample reaction conditions and to introduce the colorimetric reagent. This paper describes the status of our development of these two new methods.

  15. Magnetic Ligand Fishing as a Targeting Tool for HPLC-HRMS-SPE-NMR: ?-Glucosidase Inhibitory Ligands and Alkylresorcinol Glycosides from Eugenia catharinae.

    PubMed

    Wubshet, Sileshi G; Brighente, Inês M C; Moaddel, Ruin; Staerk, Dan

    2015-11-25

    A bioanalytical platform combining magnetic ligand fishing for ?-glucosidase inhibition profiling and HPLC-HRMS-SPE-NMR for structural identification of ?-glucosidase inhibitory ligands, both directly from crude plant extracts, is presented. Magnetic beads with N-terminus-coupled ?-glucosidase were synthesized and characterized for their inherent catalytic activity. Ligand fishing with the immobilized enzyme was optimized using an artificial test mixture consisting of caffeine, ferulic acid, and luteolin before proof-of-concept with the crude extract of Eugenia catharinae. The combination of ligand fishing and HPLC-HRMS-SPE-NMR identified myricetin 3-O-?-l-rhamnopyranoside, myricetin, quercetin, and kaempferol as ?-glucosidase inhibitory ligands in E. catharinae. Furthermore, HPLC-HRMS-SPE-NMR analysis led to identification of six new alkylresorcinol glycosides, i.e., 5-(2-oxopentyl)resorcinol 4-O-?-d-glucopyranoside, 5-propylresorcinol 4-O-?-d-glucopyranoside, 5-pentylresorcinol 4-O-[?-d-apiofuranosyl-(1?6)]-?-d-glucopyranoside, 5-pentylresorcinol 4-O-?-d-glucopyranoside, 4-hydroxy-3-O-methyl-5-pentylresorcinol 1-O-?-d-glucopyranoside, and 3-O-methyl-5-pentylresorcinol 1-O-[?-d-glucopyranosyl-(1?6)]-?-d-glucopyranoside. PMID:26496505

  16. The mitochondrial pathway of anesthetic isoflurane-induced apoptosis.

    PubMed

    Zhang, Yiying; Dong, Yuanlin; Wu, Xu; Lu, Yan; Xu, Zhipeng; Knapp, Andrew; Yue, Yun; Xu, Tiejun; Xie, Zhongcong

    2010-02-01

    The common inhalation anesthetic isoflurane has been shown to induce apoptosis, which then leads to accumulation of beta-amyloid protein, the hallmark feature of Alzheimer disease neuropathogenesis. The underlying molecular mechanism of the isoflurane-induced apoptosis is largely unknown. We, therefore, set out to assess whether isoflurane can induce apoptosis by regulating Bcl-2 family proteins, enhancing reactive oxygen species (ROS) accumulation, and activating the mitochondrial pathway of apoptosis. We performed these studies in cultured cells, primary neurons, and mice. Here we show for the first time that treatment with 2% isoflurane for 6 h can increase pro-apoptotic factor Bax levels, decrease anti-apoptotic factor Bcl-2 levels, increase ROS accumulation, facilitate cytochrome c release from the mitochondria to the cytosol, induce activation of caspase-9 and caspase-3, and finally cause apoptosis as compared with the control condition. We have further found that isoflurane can increase the mRNA levels of Bax and reduce the mRNA levels of Bcl-2. The isoflurane-induced ROS accumulation can be attenuated by the intracellular calcium chelator BAPTA. Finally, the anesthetic desflurane does not induce activation of mitochondrial pathway of apoptosis. These results suggest that isoflurane may induce apoptosis through Bcl-2 family proteins- and ROS-associated mitochondrial pathway of apoptosis. These findings, which have identified at least partially the molecular mechanism by which isoflurane induces apoptosis, will promote more studies aimed at studying the potential neurotoxic effects of anesthetics. PMID:20007710

  17. The Mitochondrial Pathway of Anesthetic Isoflurane-induced Apoptosis*

    PubMed Central

    Zhang, Yiying; Dong, Yuanlin; Wu, Xu; Lu, Yan; Xu, Zhipeng; Knapp, Andrew; Yue, Yun; Xu, Tiejun; Xie, Zhongcong

    2010-01-01

    The common inhalation anesthetic isoflurane has been shown to induce apoptosis, which then leads to accumulation of ?-amyloid protein, the hallmark feature of Alzheimer disease neuropathogenesis. The underlying molecular mechanism of the isoflurane-induced apoptosis is largely unknown. We, therefore, set out to assess whether isoflurane can induce apoptosis by regulating Bcl-2 family proteins, enhancing reactive oxygen species (ROS) accumulation, and activating the mitochondrial pathway of apoptosis. We performed these studies in cultured cells, primary neurons, and mice. Here we show for the first time that treatment with 2% isoflurane for 6 h can increase pro-apoptotic factor Bax levels, decrease anti-apoptotic factor Bcl-2 levels, increase ROS accumulation, facilitate cytochrome c release from the mitochondria to the cytosol, induce activation of caspase-9 and caspase-3, and finally cause apoptosis as compared with the control condition. We have further found that isoflurane can increase the mRNA levels of Bax and reduce the mRNA levels of Bcl-2. The isoflurane-induced ROS accumulation can be attenuated by the intracellular calcium chelator BAPTA. Finally, the anesthetic desflurane does not induce activation of mitochondrial pathway of apoptosis. These results suggest that isoflurane may induce apoptosis through Bcl-2 family proteins- and ROS-associated mitochondrial pathway of apoptosis. These findings, which have identified at least partially the molecular mechanism by which isoflurane induces apoptosis, will promote more studies aimed at studying the potential neurotoxic effects of anesthetics. PMID:20007710

  18. 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

  19. 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.

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

    PubMed

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

    2016-01-01

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

  1. D1 protein turnover is involved in protection of Photosystem II against UV-B induced damage in the cyanobacterium Arthrospira (Spirulina) platensis.

    PubMed

    Wu, Hongyan; Abasova, Leyla; Cheregi, Otilia; Deák, Zsuzsanna; Gao, Kunshan; Vass, Imre

    2011-01-01

    By using two strains of Arthrospira (Spirulina)platensis, an economically important filamentous cyanobacterium, we compared the impairment of PSII activity and loss of D1 protein content under UV-B radiation. Our study showed that UV-B radiation induced a gradual loss of the oxygen-evolving activity to about 56% after 180 min UV-B irradiation both in strains 439 and D-0083, which have been kept under indoor and an outdoor culturing conditions, respectively for a prolonged period of time. The loss of oxygen evolution was accelerated in both strains in the presence of lincomycin, an inhibitor of protein synthesis, and the amount of D1 protein showed a decrease comparable to that of oxygen evolution during the UV-B exposure. However, the UV-B induced loss of oxygen-evolving activity and D1 protein amount was largely prevented when A. platensis cells were exposed to UV-B irradiance supplemented with visible light. Comparison of the two strains also showed a smaller extent of D1 protein synthesis dependent PSII repair in the indoor strain. Our results show that turnover of the D1 protein is an important defense mechanism to counteract the UV-B induced damage of PSII in A. platensis, and also that visible light plays an important role in maintaining the function of PSII under simultaneous exposure to UV-B and visible light. PMID:21300555

  2. An optimized and validated SPE-LC-MS/MS method for the determination of caffeine and paraxanthine in hair.

    PubMed

    De Kesel, Pieter M M; Lambert, Willy E; Stove, Christophe P

    2015-11-01

    Caffeine is the probe drug of choice to assess the phenotype of the drug metabolizing enzyme CYP1A2. Typically, molar concentration ratios of paraxanthine, caffeine's major metabolite, to its precursor are determined in plasma following administration of a caffeine test dose. The aim of this study was to develop and validate an LC-MS/MS method for the determination of caffeine and paraxanthine in hair. The different steps of a hair extraction procedure were thoroughly optimized. Following a three-step decontamination procedure, caffeine and paraxanthine were extracted from 20mg of ground hair using a solution of protease type VIII in Tris buffer (pH 7.5). Resulting hair extracts were cleaned up on Strata-X™ SPE cartridges. All samples were analyzed on a Waters Acquity UPLC® system coupled to an AB SCIEX API 4000™ triple quadrupole mass spectrometer. The final method was fully validated based on international guidelines. Linear calibration lines for caffeine and paraxanthine ranged from 20 to 500pg/mg. Precision (%RSD) and accuracy (%bias) were below 12% and 7%, respectively. The isotopically labeled internal standards compensated for the ion suppression observed for both compounds. Relative matrix effects were below 15%RSD. The recovery of the sample preparation procedure was high (>85%) and reproducible. Caffeine and paraxanthine were stable in hair for at least 644 days. The effect of the hair decontamination procedure was evaluated as well. Finally, the applicability of the developed procedure was demonstrated by determining caffeine and paraxanthine concentrations in hair samples of ten healthy volunteers. The optimized and validated method for determination of caffeine and paraxanthine in hair proved to be reliable and may serve to evaluate the potential of hair analysis for CYP1A2 phenotyping. PMID:26452792

  3. Aloin induces apoptosis in Jurkat cells.

    PubMed

    Buenz, Eric J

    2008-03-01

    Aloe is widely used as a dietary supplement. However, there are continuing concerns over the toxicity and the purity of aloe-based products. The primary class of compounds responsible for aloe-induced toxicity are anthraquinones. One of these, aloe-emodin, has been extensively investigated for apoptosis inducing effects. Conversely, the precursor to aloe-emodin, aloin, has been subjected to only minimal investigation of any cytotoxic effects. Jurkat T cells, an established model for the study of compound toxicity, were used to evaluate the effect of aloin on cell viability. Cells were analyzed using flow cytometry and microscopy for cell size and granularity, cell membrane integrity, mitochondrial membrane potential, and cell cycle profile. Treatment with aloin resulted in a reduction in cell size, compromised membrane integrity, and loss of mitochondrial membrane potential in a dose-dependent manner. Additionally, treatment with aloin resulted in alteration of the cell cycle, specifically a block at G2/M phase. Importantly, the loss of cell membrane integrity was preceded by a loss of mitochondrial membrane potential, suggesting a mitochondrial-dependent pathway for aloin-induced apoptosis. These observations provide insight into the potential mechanisms of aloin-induced toxicity and thus, perhaps, aloe preparation-induced toxicity. Furthermore, because of the concern over the safety of aloe-based supplements, this work suggests that aloe supplements not containing aloin may be safer than aloe supplements containing aloin, and that aloin should be considered in addition to concentrations of aloe-emodin. PMID:18068945

  4. Rosiglitazone induces cardiotoxicity by accelerated apoptosis.

    PubMed

    Mishra, Pratibha; Singh, Sarvendra Vikram; Verma, Ajeet Kumar; Srivastava, Pallavi; Sultana, Sarwat; Rath, Srikanta Kumar

    2014-06-01

    Present investigation explores the cardiotoxicity of rosiglitazone (ROSI) using rat heart cardiomyocytes and db/db mice. In H9c2 cells, ROSI at 50 and 60 ?M induced an increase in the percentage of apoptotic cells and superoxide generation, along with an increase in the expression of various subunits of NADPH oxidase and nitric oxide synthases, confirmed that ROSI-induced apoptosis in H9c2 cells is by ROS generation. The increase in the expression of the antioxidants like superoxide dismutase (SOD), catalase, glutathione reductase (GR), glutathione-S-transferase (GST), and glutathione peroxidase (GPx) further confirmed this notion. Heme oxygenase-1, having an important role in cell protection against oxidative stress, was found to be increased along with induction of nuclear translocation of NF-E2-related factor and increased protein kinase C ? expression. Moreover, in db/db mice, oral administration of ROSI (10 mg/kg) for 10 days induced an increase in serum creatinine kinase-MB, tissue antioxidants like SOD, catalase, GR, GST, GPx expression, cardiac troponin T, and inducible nitric oxide synthase protein expression strongly support the in vitro findings. Furthermore, global gene expression studies also showed the perturbation of oxidative phosphorylation, fat cell differentiation, and electron transport chain following ROSI treatment in vivo. These results suggested that ROSI-induced cardiac damage is due to accelerated apoptosis both in vitro and in vivo. PMID:24249632

  5. Caspase pathways, neuronal apoptosis, and CNS injury.

    PubMed

    Eldadah, B A; Faden, A I

    2000-10-01

    Caspases are a family of mammalian proteases related to the ced-3 gene of Caenorhabditis elegans. They mediate many of the morphological and biochemical features of apoptosis, including structural dismantling of cell bodies and nuclei, fragmentation of genomic DNA, destruction of regulatory proteins, and propagation of other pro-apoptotic molecules. Based on their substrate specificities and DNA sequence homologies, the 14 currently identified caspases may be divided into three groups: apoptotic initiators, apoptotic executioners, and inflammatory mediators. Caspases are activated through two principal pathways, known as the "extrinsic pathway," which is initiated by cell surface death receptor ligation, and the intrinsic pathway, which arises from mitochondria. Endogenous inhibitors, such as the inhibitors of apoptosis (IAP) family, modulate caspase activity at various points within these pathways. Upon activation, caspases appear to play an important role in sequelae of traumatic brain injury, spinal cord injury, and cerebral ischemia. In addition, they may also play a role in mediating cell death in chronic neurodegenerative conditions such as Alzheimer's disease, Huntington's disease, and amyotrophic lateral sclerosis. This article reviews the current literature on the role of caspases in acute and chronic CNS injury, and provides evidence for the potential therapeutic use of caspase inhibitors in the setting of these conditions. PMID:11063050

  6. Glutathione and modulation of cell apoptosis

    PubMed Central

    Circu, Magdalena L.; Aw, Tak Yee

    2012-01-01

    Apoptosis is a highly organized form of cell death that is important for tissue homeostasis, organ development and senescence. To date, the extrinsic (death receptor mediated) and intrinsic (mitochondria derived) apoptotic pathways have been characterized in mammalian cells. Reduced glutathione, GSH, is the most prevalent cellular thiol that plays an essential role in preserving a reduced intracellular environment. GSH protection of cellular macromolecules like DNA, proteins and lipids against oxidizing, environmental and cytotoxic agents, underscores its central anti-apoptotic function. Reactive oxygen and nitrogen species (ROS/RNS) can oxidize cellular GSH or induce its extracellular export leading to the loss of intracellular redox homeostasis and activation of the apoptotic signaling cascade. Recent evidence uncovered a novel role for GSH involvement in apoptotic signaling pathways wherein post-translational S-glutathiolation of protein redox active cysteines is implicated in the potentiation of apoptosis. In the present review we focus on the key aspects of GSH redox mechanisms associated with apoptotic signaling that includes: (a) changes in cellular GSH redox homeostasis through GSH oxidation or GSH transport in relation to the initiation or propagation of the apoptotic cascade, and (b) evidence for S-glutathiolation in protein modulation and apoptotic initiation. PMID:22732297

  7. Ecdysone signaling at metamorphosis triggers apoptosis of Drosophila abdominal muscles

    E-print Network

    Higgins, Darren

    Ecdysone signaling at metamorphosis triggers apoptosis of Drosophila abdominal muscles Jonathan KeywordsQ3 : Metamorphosis Muscle Drosophila Histolysis Apoptosis Autophagy Ecdysone Ftz-f1 a b s t r a c t One of the most dramatic examples of programmed cell death occurs during Drosophila metamorphosis

  8. Targeting adipocyte apoptosis: a novel strategy for obesity therapy.

    PubMed

    Zhang, Yu; Huang, Cheng

    2012-01-01

    Obesity is an increasing world problem that may cause several metabolic complications including insulin resistance, hyperlipidemia, hypertension, and atherosclerosis. Development of therapeutic drugs for obesity has been proven difficult. Current strategies for weight reduction are inhibition of food intake through the central nervous system or blocking the absorption of lipids in the gut. These therapies have many side effects, so new treatments are urgently needed. Fat loss could also be achieved through a decrease in the size and number of adipocytes through apoptosis. Apoptosis is a normal phenomenon of cell death for the purpose of maintaining homeostasis. Induction of apoptosis is a reasonable way to remove adipocytes in obese patients. It is reported that several adipokines and natural products play roles in induction of adipocyte apoptosis. Here we review the recent progress of the roles and mechanisms of adipocyte apoptosis induced by leptin, tumor necrosis factor-? (TNF-?), and natural compounds. PMID:22172945

  9. Lymphocytes apoptosis in patients with acute exacerbation of asthma.

    PubMed Central

    Hamzaoui, A; Hamzaoui, K; Salah, H; Chabbou, A

    1999-01-01

    Asthma is characterized by airway inflammation, which can be now assessed by the analysis of induced sputum. Ten patients with asthma were investigated during acute exacerbation for the quantification of apoptosis, for Bcl-2 and Fas expression, in induced sputum lymphocytes. They were compared to 12 patients with chronic obstructive pulmonary disease (COPD), and 10 healthy controls. Spontaneous apoptosis was determined by staining nuclei with propidium iodide, and analyzed with a FACScan. Bcl-2 was measured by Western blotting, and results were obtained by densitometric scanning, done by the gel proanalyser. The investigation of Fas was performed using the streptavidin-biotin preroxidase-complex method. Patients with asthma and patients with COPD exhibited a significant increase of cellularity, percentage of neutrophils, eosinophils and lymphocytes when compared to healthy controls. Apoptosis in induced sputum mononuclear cells was found decreased in patients with asthma compared to COPD patients and healthy controls. The quantification of apoptosis was measured after exposure to anti-cytokine antibodies. Anti-TNF-alpha antibody blocked the apoptosis in both patients groups and healthy controls, suggesting that TNF-alpha acted as an inducer of apoptosis. Anti-IL-10 blocked apoptosis completely exclusively in patients with asthma. Bcl-2 expression was found to be increased in induced sputum mononuclear cells from patients with asthma, compared to healthy controls and patients with COPD. Expression of Fas could be detected in patients with asthma, at a lower level than COPD patients and healthy controls. Distinct mechanisms of apoptosis were found in patients with asthma and patients with COPD, characterized by different levels of Bcl-2 and Fas expression. Induction of apoptosis should be a beneficial process in allergic inflammation traduced in induced sputum mononuclear cells. The apoptosis process is assumed by two different mechanisms in asthma and COPD. Our findings indicated that in asthmatic patients, activated lymphocytes accumulate in the bronchi; because of their prolonged survival that maintains inflammation. PMID:10704078

  10. microRNA-29b prevents liver fibrosis by attenuating hepatic stellate cell activation and inducing apoptosis through targeting PI3K/AKT pathway

    PubMed Central

    Wang, Jia; Chu, Eagle S.H.; Chen, Hai-Yong; Man, Kwan; Go, Minnie Y.Y.; Huang, Xiao Ru; Lan, Hui Yao; Sung, Joseph J.Y.; Yu, Jun

    2015-01-01

    microRNA-29b (miR-29b) is known to be associated with TGF-?-mediated fibrosis, but the mechanistic action of miR-29b in liver fibrosis remains unclear and is warranted for investigation. We found that miR-29b was significantly downregulated in human and mice fibrotic liver tissues and in primary activated HSCs. miR-29b downregulation was directly mediated by Smad3 through binding to the promoter of miR-29b in hepatic stellate cell (HSC) line LX1, whilst miR-29b could in turn suppress Smad3 expression. miR-29b transduction in the liver of mice prevented CCl4 induced-fibrogenesis, concomitant with decreased expression of ?-SMA, collagen I and TIMP-1. Ectopic expression of miR-29b in activated HSCs (LX-1, HSC-T6) inhibited cell viability and colony formation, and caused cell cycle arrest in G1 phase by downregulating cyclin D1 and p21cip1. Further, miR-29b induced apoptosis in HSCs mediated by caspase-9 and PARP. miR-29b inhibited its downstream effectors of PIK3R1 and AKT3 through direct targeting their 3?UTR regions. Moreover, knockdown of PIK3R1 or AKT3 suppressed ?-SMA and collagen I and induced apoptosis in both HSCs and in mice. In conclusion, miR-29b prevents liver fibrogenesis by inhibiting HSC activation and inducing HSC apoptosis through inhibiting PI3K/AKT pathway. These results provide novel mechanistic insights for the anti-fibrotic effect of miR-29b. PMID:25356754

  11. Orally Administered Fructose Increases the Numbers of Peripheral Lymphocytes Reduced by Exposure of Mice to Gamma or SPE-like Proton Radiation.

    PubMed

    Romero-Weaver, A L; Ni, J; Lin, L; Kennedy, A R

    2014-07-01

    Exposure of the whole body or a major portion of the body to ionizing radiation can result in Acute Radiation Sickness (ARS), which can cause symptoms that range from mild to severe, and include death. One of the syndromes that can occur during ARS is the hematopoietic syndrome, which is characterized by a reduction in bone marrow cells as well as the number of circulating blood cells. Doses capable of causing this syndrome can result from conventional radiation therapy and accidental exposure to ionizing radiation. It is of concern that this syndrome could also occur during space exploration class missions in which astronauts could be exposed to significant doses of solar particle event (SPE) radiation. Of particular concern is the reduction of lymphocytes and granulocytes, which are major components of the immune system. A significant reduction in their numbers can compromise the immune system, causing a higher risk for the development of infections which could jeopardize the success of the mission. Although there are no specific countermeasures utilized for the ARS resulting from exposure to space radiation(s), granulocyte colony-stimulating factor (G-CSF) has been proposed as a countermeasure for the low number of neutrophils caused by SPE radiation, but so far no countermeasure exists for a reduced number of circulating lymphocytes. The present study demonstrates that orally administered fructose significantly increases the number of peripheral lymphocytes reduced by exposure of mice to 2 Gy of gamma- or SPE-like proton radiation, making it a potential countermeasure for this biological end-point. PMID:25360417

  12. Comprehensive non-targeted analysis of contaminated groundwater of a former ammunition destruction site using 1H-NMR and HPLC-SPE-NMR/TOF-MS.

    PubMed

    Godejohann, Markus; Heintz, Lea; Daolio, Cristina; Berset, Jean-Daniel; Muff, Daniel

    2009-09-15

    The aim of the present study was to explore the capabilities of the combination of 1H NMR (proton nuclear magnetic resonance) mixture analysis and HPLC-SPE-NMR/TOF-MS (high-performance liquid chromatography coupled to solid-phase extraction and nuclear magnetic resonance and time-of-flight mass spectrometry) for the characterization of xenobiotic contaminants in groundwater samples. As an example, solid-phase extracts of two groundwater samples taken from a former ammunition destruction site in Switzerland were investigated. 1H NMR spectra of postcolumn SPE enriched compounds, together with accurate mass measurements, allowed the structural elucidation of unknowns. This untargeted approach allowed us to identify expected residues of explosives such as 2,4,6-trinitrotoluene (2,4,6-TNT), Hexogen (RDX) and Octogen (HMX), degradation products of TNT (1,3,5-trinitrobenzene (1,3,5-TNB), 2-amino-4,6-dinitrotoluene (2-A-4,6-DNT), 3,5-dinitrophenol (3,5-DNP), 3,5-dinitroaniline (3,5-DNA), 2,6-dinitroanthranite, and 2-Hydroxy-4,6-dinitrobenzonitrile), benzoic acid, Bisphenol A (a known endocrine disruptor compound), and some toxicologically relevant additives for propelling charges: Centralite I (1,3-diethyl-1,3-diphenylurea), DPU (N,N-diphenylurethane), N,N-diphenylcarbamate (Acardite II), and N-methyl-N-phenylurethane. To our knowledge, this is the first report of the presence of these additives in environmental samples. Extraction recoveries for Centralite I and DPU have been determined. Contaminants identified by our techniques were quantified based on HPLC-UV (HPLC-ultraviolet detection) and 1H NMR mixture analysis. The concentrations of the contaminants ranged between 0.1 and 48 microg/L assuming 100% recovery for the SPE step. PMID:19806741

  13. Orally Administered Fructose Increases the Numbers of Peripheral Lymphocytes Reduced by Exposure of Mice to Gamma or SPE-like Proton Radiation

    PubMed Central

    Romero-Weaver, A.L.; Ni, J.; Lin, L.; Kennedy, A.R.

    2014-01-01

    Exposure of the whole body or a major portion of the body to ionizing radiation can result in Acute Radiation Sickness (ARS), which can cause symptoms that range from mild to severe, and include death. One of the syndromes that can occur during ARS is the hematopoietic syndrome, which is characterized by a reduction in bone marrow cells as well as the number of circulating blood cells. Doses capable of causing this syndrome can result from conventional radiation therapy and accidental exposure to ionizing radiation. It is of concern that this syndrome could also occur during space exploration class missions in which astronauts could be exposed to significant doses of solar particle event (SPE) radiation. Of particular concern is the reduction of lymphocytes and granulocytes, which are major components of the immune system. A significant reduction in their numbers can compromise the immune system, causing a higher risk for the development of infections which could jeopardize the success of the mission. Although there are no specific countermeasures utilized for the ARS resulting from exposure to space radiation(s), granulocyte colony-stimulating factor (G-CSF) has been proposed as a countermeasure for the low number of neutrophils caused by SPE radiation, but so far no countermeasure exists for a reduced number of circulating lymphocytes. The present study demonstrates that orally administered fructose significantly increases the number of peripheral lymphocytes reduced by exposure of mice to 2 Gy of gamma- or SPE-like proton radiation, making it a potential countermeasure for this biological end-point. PMID:25360417

  14. Apoptosis and the systolic dysfunction in congestive heart failure. Story of apoptosis interruptus and zombie myocytes.

    PubMed

    Narula, J; Arbustini, E; Chandrashekhar, Y; Schwaiger, M

    2001-02-01

    Although previously it was believed that apoptosis could not occur in the terminally differentiated tissue, such as adult heart muscle cells, recent studies in endomyocardial biopsies from patients with dilated cardiomyopathy and in explanted hearts from patients with end-stage heart failure undergoing cardiac transplantation have demonstrated histologic evidence of apoptosis. Whereas neurohormonal activation during heart failure leads to compensatory hemodynamic alterations, coupled with ventricular dilatation, it induces transcription factors and myocyte hypertrophy. Persistent growth stimulation in terminally differentiated cells may lead paradoxically to apoptotic cell death. The apoptosis in cardiomyopathic hearts is associated with cytochrome c release from mitochondria to cytoplasm and activation of proteolytic caspase-8 and -3. Although the caspases are duly processed, the fragmentation of the nuclear proteins (including DNA) is completed less frequently, and only a variable degree of fragmentation of cytoplasmic proteins (including contractile proteins) is observed. It is hypothesized that release of cytochrome c from mitochondria should interfere with energy production and lead to functional impairment and variable loss of contractile proteins in a living heart muscle cell should contribute to systolic dysfunction. Because a nuclear blueprint is retained, however, the dysfunctional cell may continue to exist and in favorable conditions, such as with LVAD support, the apoptotic process may subside. Potential feasibility of reversal of heart failure should renew efforts to develop more targeted pharmaceutical intervention within the apoptotic cascade and allow newer paradigm for the management of heart failure. PMID:11787805

  15. 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. PMID:26059439

  16. Apoptosis in thymus of teleost fish.

    PubMed

    Romano, Nicla; Ceccarelli, Giuseppina; Caprera, Cecilia; Caccia, Elisabetta; Baldassini, Maria Rosaria; Marino, Giovanna

    2013-08-01

    The presence and distribution of apoptotic cells during thymus development and in adult were studied by in situ end-labelling of fragmented DNA in three temperate species carp (Cyprinus carpio), sea bass (Dicentrarchus labrax) and dusky grouper (Epinephelus marginatus) and in the adult thymus of three Antarctic species belonging to the genus Trematomus spp. During thymus development some few isolated apoptotic cell (AC) firstly appeared in the central-external part of the organ (carp: 5 days ph; sea bass: 35 days ph grouper: 43 days ph). Initially the cells were isolated and then increased in number and aggregated in small groups in the outer-cortical region of the thymus larvae. The high density of apoptotic cells was observed in the junction between cortex and medulla from its appearance (border between cortex and medulla, BCM). ACs decreased in number in juveniles and adult as well as the ACs average diameter. In late juveniles and in adulthood, the apoptosis were restricted to the cortex. In Antarctic species the thymus is highly adapted to low temperature (high vascularisation to effort the circulation of glycoproteins enriched plasma and strongly compact parenchyma). The apoptosis process was more extended (4-7 fold) as compare with the thymus of temperate species, even if the distribution of ACs was similar in all examined species. Data suggested a common process of T lymphocyte negative-selection in BCM of thymus during the ontogeny. The selection process seems to be still active in adult polar fish, but restricted mainly in the cortex zone. PMID:23639932

  17. RTF+SpeX Near-IR Images and Spectra of the Moon Pre-impact and at Impact of SMART-1

    NASA Technical Reports Server (NTRS)

    Wooden, Diane H.; Ennico, Kimberly A.; Colaprete, Anthony; Lucey, Paul G.; Tokunaga, Alan T.; Rayner, John T.; Meech, Karen J.; Foing, B.; Ehrenfreund, P.

    2006-01-01

    We present SpeX 0.8-2.5 micron spectra and Br-gamma or J H or K-band images of the Moon on 2006 July 10 UT, 2006 Sep 1 UT, and 2006 Sep 3 UT. The first two dates are data taken in preparation (near Full Moon and 1 st quarter Moon) for observing the impact of ESA's SMART-1 Lunar satellite on 2006 Sep 3 UT. We hope to be presenting images (about 1 arc minute by 1 arc minute), and low resolution (Prism mode) spectra of the SMART-1 impact to be taken with the 60 arc second long slit.

  18. Fully automated trace level determination of parent and alkylated PAHs in environmental waters by online SPE-LC-APPI-MS/MS.

    PubMed

    Ramirez, Cesar E; Wang, Chengtao; Gardinali, Piero R

    2014-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous compounds that enter the environment from natural and anthropogenic sources, often used as markers to determine the extent, fate, and potential effects on natural resources after a crude oil accidental release. Gas chromatography-mass spectrometry (GC-MS) after liquid-liquid extraction (LLE+GC-MS) has been extensively used to isolate and quantify both parent and alkylated PAHs. However, it requires labor-intensive extraction and cleanup steps and generates large amounts of toxic solvent waste. Therefore, there is a clear need for greener, faster techniques with enough reproducibility and sensitivity to quantify many PAHs in large numbers of water samples in a short period of time. This study combines online solid-phase extraction followed by liquid chromatography (LC) separation with dopant-assisted atmospheric pressure photoionization (APPI) and tandem MS detection, to provide a one-step protocol that detects PAHs at low nanograms per liter with almost no sample preparation and with a significantly lower consumption of toxic halogenated solvents. Water samples were amended with methanol, fortified with isotopically labeled PAHs, and loaded onto an online SPE column, using a large-volume sample loop with an auxiliary LC pump for sample preconcentration and salt removal. The loaded SPE column was connected to an UPLC pump and analytes were backflushed to a Thermo Hypersil Green PAH analytical column where a 20-min gradient separation was performed at a variable flow rate. Detection was performed by a triple-quadrupole MS equipped with a gas-phase dopant delivery system, using 1.50 mL of chlorobenzene dopant per run. In contrast, LLE+GC-MS typically use 150 mL of organic solvents per sample, and methylene chloride is preferred because of its low boiling point. However, this solvent has a higher environmental persistence than chlorobenzene and is considered a carcinogen. The automated system is capable of performing injection, online SPE, inorganic species removal, LC separation, and MS/MS detection in 28 min. Selective reaction monitoring was used to detect 28 parent PAHs and 15 families of alkylated PAHs. The methodology is comparable to traditional GC-MS and was tested with surface seawater, rainwater runoff, and a wastewater treatment plant effluent. Positive detections above reporting limits are described. The virtual absence of sample preparation could be particularly advantageous for real-time monitoring of discharge events that introduce PAHs into environmental compartments, such as accidental releases of petroleum derivates and other human-related events. This work covers optimization of APPI detection and SPE extraction efficiency, a comparison with LLE+GC-MS in terms of sensitivity and chromatographic resolution, and examples of environmental applications. PMID:24217946

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

    PubMed

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

    2015-03-01

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

  20. TRPV1 receptors mediate particulate matter-induced apoptosis.

    PubMed

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

    2004-03-01

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

  1. Identification of apoptosis-related PLZF target genes

    SciTech Connect

    Bernardo, Maria Victoria; Yelo, Estefania; Gimeno, Lourdes; Campillo, Jose Antonio; Parrado, Antonio . E-mail: antonio.parrado@carm.es

    2007-07-27

    The PLZF gene encodes a BTB/POZ-zinc finger-type transcription factor, involved in physiological development, proliferation, differentiation, and apoptosis. In this paper, we investigate proliferation, survival, and gene expression regulation in stable clones from the human haematopoietic K562, DG75, and Jurkat cell lines with inducible expression of PLZF. In Jurkat cells, but not in K562 and DG75 cells, PLZF induced growth suppression and apoptosis in a cell density-dependent manner. Deletion of the BTB/POZ domain of PLZF abrogated growth suppression and apoptosis. PLZF was expressed with a nuclear speckled pattern distinctively in the full-length PLZF-expressing Jurkat clones, suggesting that the nuclear speckled localization is required for PLZF-induced apoptosis. By microarray analysis, we identified that the apoptosis-inducer TP53INP1, ID1, and ID3 genes were upregulated, and the apoptosis-inhibitor TERT gene was downregulated. The identification of apoptosis-related PLZF target genes may have biological and clinical relevance in cancer typified by altered PLZF expression.

  2. TRB3 mediates renal tubular cell apoptosis associated with proteinuria.

    PubMed

    Wang, Weiwei; Cheng, Jing; Sun, Aili; Lv, Shasha; Liu, Haiying; Liu, Xiangchun; Guan, Guangju; Liu, Gang

    2015-05-01

    Proteinuria may contribute to progressive renal damage by inducing tubulointerstitial inflammation, fibrosis and tubular cell apoptosis, but the underlying mechanisms remain largely unknown. TRB3 is a kinase-like molecule that can modify cellular survival and interfere with signal transduction pathways. We seek to determine the role of TRB3 in renal tubular cell apoptosis associated with proteinuria. Herein, we reported that in a rat tubular cell line, high concentration of albumin augmented TRB3 expression and induced apoptosis, while TRB3 silencing with special small interference RNA significantly attenuated apoptosis. In addition, we found that albumin-induced apoptosis was related to inhibition of Akt phosphorylation, which was, however, partially reversed by TRB3 silencing, indicating that TRB3 worked through Akt pathway in this apoptotic signaling cascade. In vivo, we observed increased TRB3 expression in kidneys of streptozotocin-induced diabetic nephropathy model and albumin-overload nephropathy model, both of which showed overt proteinuria. Notably, proteinuria induced apoptosis in renal tubules, which was less severe after genetically inhibition of TRB3. Taken together, these results suggest that TRB3 mediates renal tubular cell apoptosis induced by protein overload, broadening our understanding of the pathogenesis of progressive proteinuric kidney diseases. PMID:24925634

  3. Probing of cancer cell apoptosis by SERS and LSCM

    NASA Astrophysics Data System (ADS)

    Kang, Jian; Gu, Huaimin

    2009-07-01

    Surface enhanced Raman spectroscopy (SERS) can provide information of internal structures and chemical components from different kinds of samples. Laser scanning confocal microscopy (LSCM) can show morphologic information of samples by high-resolution optical images with different focal planes. In this paper, the dynamic variation of cancer cells (HELA cells) in the apoptosis was first studied by combining SERS and LSCM. After gold nanoparticles (GNPS) uptake, HELA cells were divided into two groups, and were respectively studied at six different time points of cell apoptosis period by SERS and LSCM. The LSCM images of HELA cells obtained at different time points were analyzed, and the morphology varieties of HELA cells apoptosis were obtained. It suggests that HELA cells apoptosis gradually in the apoptosis period until they died. In addition, Raman spectra of HELA cells measured at different time points were also compared. It shows that some Raman signal peaks shift, and FWHM of Raman peaks change too. The variation of internal structures and chemical constituents were analyzed according to the shifts and FWHM of the Raman peaks. The internal dynamic information and morphologic varieties from HELA cells apoptosis gained by combining SERS and LSCM will make us to understand cancer cell apoptosis throughly.

  4. Apoptosis of cholangiocytes modulated by thioredoxin of carcinogenic liver fluke.

    PubMed

    Matchimakul, Pitchaya; Rinaldi, Gabriel; Suttiprapa, Sutas; Mann, Victoria H; Popratiloff, Anastas; Laha, Thewarach; Pimenta, Rafael N; Cochran, Christina J; Kaewkes, Sasithorn; Sripa, Banchob; Brindley, Paul J

    2015-08-01

    Chronic infection with the food-borne liver fluke, Opisthorchis viverrini, frequently induces cancer of the bile ducts, cholangiocarcinoma. Opisthorchiasis is endemic in Thailand, Lao PDR, Cambodia and Vietnam, where eating undercooked freshwater fish carrying the juvenile stage of this pathogen leads to human infection. Because inhibition of apoptosis facilitates carcinogenesis, this study investigated modulation by thioredoxin from O. viverrini of apoptosis of bile duct epithelial cells, cholangiocytes. Cells of a cholangiocyte line were incubated with the parasite enzyme after which they were exposed hydrogen peroxide. Oxidative stress-induced apoptosis was monitored using flow cytometry, growth in real time and imaging of living cells using laser confocal microscopy. Immunolocalization revealed liver fluke thioredoxin within cholangiocytes. Cells exposed to thioredoxin downregulated apoptotic genes in the mitogen activated protein kinases pathway and upregulated anti-apoptosis-related genes including apoptosis signaling kinase 1, caspase 9, caspase 8, caspase 3, survivin and others. Western blots of immunoprecipitates of cell lysates revealed binding of thioredoxin to apoptosis signaling kinase 1. Together the findings indicated that thioredoxin from O. viverrini inhibited oxidative stress-induced apoptosis of bile duct epithelial cells, which supports a role for this liver fluke oxidoreductase in opisthorchiasis-induced cholangiocarcinogenesis. PMID:26007234

  5. An inflammatory micro-environment promotes human adipocyte apoptosis.

    PubMed

    Keuper, Michaela; Blüher, Matthias; Schön, Michael R; Möller, Peter; Dzyakanchuk, Anna; Amrein, Kurt; Debatin, Klaus-Michael; Wabitsch, Martin; Fischer-Posovszky, Pamela

    2011-06-01

    Obesity-associated macrophage infiltration into adipose tissue is responsible for both local and systemic inflammation. Recent findings suggest fat cell apoptosis as an initiator of macrophage recruitment. Here, we investigated the effects of an inflammatory micro-environment on fat cells using human THP-1 macrophages and SGBS adipocytes. Macrophage-secreted factors induced insulin resistance, inhibited insulin-stimulated Akt phosphorylation, and induced apoptosis of adipocytes. The apoptosis-inducing effect was even more pronounced in direct co-cultures of adipocytes and macrophages. Our data suggest a link between insulin resistance and apoptosis sensitivity. Accordingly, pharmacological and genetic inhibition of insulin signaling at the level of Akt2 sensitized adipocytes to apoptosis induction by macrophage-secreted factors. In conclusion, we describe here a novel interaction of macrophages and fat cells, i.e. induction of apoptosis. Our data suggest a feed-forward cycle in which macrophages further drive the inflammatory process by inducing insulin resistance and concomitant apoptosis of adipocytes. PMID:21501656

  6. Ultraviolet-B-Induced Stomatal Closure in Arabidopsis Is Regulated by the UV RESISTANCE LOCUS8 Photoreceptor in a Nitric Oxide-Dependent Mechanism1[C][W

    PubMed Central

    Tossi, Vanesa; Lamattina, Lorenzo; Jenkins, Gareth I.; Cassia, Raúl O.

    2014-01-01

    UV RESISTANCE LOCUS8 (UVR8) signaling involves CONSTITUTIVELY PHOTOMORPHOGENIC1, the ELONGATED HYPOCOTYL5 (HY5) transcription factor, and the closely related HY5 HOMOLOG. Some UV-B responses mediated by UVR8 are also regulated by nitric oxide (NO), a bioactive molecule that orchestrates a wide range of processes in plants. In this study, we investigated the participation of the UVR8 pathway and its interaction with NO in UV-B-induced stomatal movements in Arabidopsis (Arabidopsis thaliana). Stomata in abaxial epidermal strips of Arabidopsis ecotype Landsberg erecta closed in response to increasing UV-B fluence rates, with maximal closure after 3-h exposure to 5.46 ?mol m–2 s–1 UV-B. Both hydrogen peroxide (H2O2) and NO increased in response to UV-B, and stomatal closure was maintained by NO up to 24 h after the beginning of exposure. Stomata of plants expressing bacterial NO dioxygenase, which prevents NO accumulation, did not close in response to UV-B, although H2O2 still increased. When the uvr8-1 null mutant was exposed to UV-B, stomata remained open, irrespective of the fluence rate. Neither NO nor H2O2 increased in stomata of the uvr8-1 mutant. However, the NO donor S-nitrosoglutathione induced closure of uvr8-1 stomata to the same extent as in the wild type. Experiments with mutants in UVR8 signaling components implicated CONSTITUTIVELY PHOTOMORPHOGENIC1, HY5, and HY5 HOMOLOG in UV-B-induced stomatal closure. This research provides evidence that the UVR8 pathway regulates stomatal closure by a mechanism involving both H2O2 and NO generation in response to UV-B exposure. PMID:24586043

  7. Stochastic modeling of p53-regulated apoptosis upon radiation damage

    E-print Network

    Bhatt, Divesh; Bahar, Ivet

    2011-01-01

    We develop and study the evolution of a model of radiation induced apoptosis in cells using stochastic simulations, and identified key protein targets for effective mitigation of radiation damage. We identified several key proteins associated with cellular apoptosis using an extensive literature survey. In particular, we focus on the p53 transcription dependent and p53 transcription independent pathways for mitochondrial apoptosis. Our model reproduces known p53 oscillations following radiation damage. The key, experimentally testable hypotheses that we generate are - inhibition of PUMA is an effective strategy for mitigation of radiation damage if the treatment is administered immediately, at later stages following radiation damage, inhibition of tBid is more effective.

  8. Simultaneous determination of isoflavones and resveratrols for adulteration detection of soybean and peanut oils by mixed-mode SPE LC-MS/MS.

    PubMed

    Zhao, Xin; Ma, Fei; Li, Peiwu; Li, Guangming; Zhang, Liangxiao; Zhang, Qi; Zhang, Wen; Wang, Xiupin

    2015-06-01

    To ensure authenticity of vegetable oils, isoflavones (genistein, genistin, daidzein and daidzin) and resveratrols (cis-resveratrol and trans-resveratrol) were selected as the putative markers for adulteration of soybean and peanut oils. Firstly, mixed mode solid-phase extraction coupled with liquid chromatography tandem mass spectrometry (mixed-mode SPE LC-MS/MS) method was developed to analyze isoflavones and resveratrols in vegetable oils. The concentration of marker compounds in vegetable oils were 0.08-1.47mgkg(-1) for daidzein, ND-78.9?gkg(-1) for daidzin, 0.40-5.89mgkg(-1) for genistein, 1.2-114.9?gkg(-1) for genistin, 3.1-85.0?gkg(-1) for trans-resveratrol and 1.9-51.0?gkg(-1) for cis-resveratrol, which are compatible with the raw materials for oil press. Additionally, the applicability of this method has been successfully tested in thirteen vegetable oils from the market. Mixed-mode SPE LC-MS/MS method can simultaneously detect isoflavones and resveratrols in vegetable oils and assess adulteration and quality of soybean and peanut oils. PMID:25624257

  9. Rapid determination of memantine in human plasma by using nanoring carboxyl-functionalized paramagnetic molecularly imprinted polymer d-?-SPE and UFLC-MS/MS.

    PubMed

    Qiu, Hai-Wen; Xia, Lei; Gong, Li-Min; Ruan, Lie-Min; Zhao, Yong-Gang

    2015-06-01

    A novel, simple, and sensitive method based on the use of dispersive micro-solid-phase extraction (d-?-SPE) procedure combined with ultra-fast liquid chromatography-tandem quadrupole mass spectrometry (UFLC-MS/MS) for the determination of memantine (ME) was developed and validated over the linearity range 0.05-10.0?µg/L with 100??L of human plasma using memantine-D6 (ME-D6) as the internal standard. The novel nanoring carboxyl-functionalized paramagnetic molecularly imprinted polymer (NR-CF-Mag-MIP) was synthesized by ultrasound-assisted suspension polymerization, using ME as a template molecule, methacrylic acid as a functional monomer, and divinylbenzene as a cross-linking agent. The NR-CF-Mag-MIP was used as the d-?-SPE sorbent to extract ME from human plasma samples. The obtained results demonstrated the higher extraction capacity of NR-CF-Mag-MIP with recoveries between 97.6 and 101%. The limits of quantification (LOQs) for ME was 0.015?µg/L. Validation results on linearity, specificity, accuracy, precision, and stability, as well as on application to the analysis of samples taken up to 480?h after oral administration of 20?mg (two 10?mg capsules) of ME in healthy volunteers demonstrated the applicability to bioequivalence studies. PMID:25209851

  10. Detection of Apoptosis in Cell-Free Systems

    PubMed Central

    Chandra, Dhyan; Tang, Dean G.

    2015-01-01

    Apoptosis is a fundamental process required for proper embryonic development. Various methods have been described to detect apoptosis both in vitro as well as in vivo. Activation of caspases represents the key event in the apoptotic process. To dissect the molecular events leading to caspase activation, we have been using cell-free systems that recapitulate the mitochondrial death pathway. In the cell-free apoptosis assays, we either detect caspase activation in stimulated cells by utilizing subcellular fractions or reconstitute various components in cytosol (or mitochondria) to study molecular mechanisms of caspase activation. In either case, we utilize Western blot and/or substrate cleavage to monitor caspase activation. Using in vitro reconstitution approach of caspase activation, we have discovered various factors that regulate caspase activity. Therefore, cell-free system not only is an invaluable tool to study apoptosis signaling but also provides molecular insight on caspase activation patterns and inhibitor specificities. PMID:19609749

  11. CONFOCAL LASER SCANNING MICROSCOPY OF APOPTOSIS IN WHOLE MOUSE OVARIES

    EPA Science Inventory

    Confocal Laser Scanning Microscopy of Apoptosis in Whole Mouse Ovaries. Robert M. Zucker Susan C. Jeffay and Sally D. Perreault Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle...

  12. Mitochondrial apoptosis: killing cancer using the enemy within

    PubMed Central

    Lopez, J; Tait, S W G

    2015-01-01

    Apoptotic cell death inhibits oncogenesis at multiple stages, ranging from transformation to metastasis. Consequently, in order for cancer to develop and progress, apoptosis must be inhibited. Cell death also plays major roles in cancer treatment, serving as the main effector function of many anti-cancer therapies. In this review, we discuss the role of apoptosis in the development and treatment of cancer. Specifically, we focus upon the mitochondrial pathway of apoptosis—the most commonly deregulated form of cell death in cancer. In this process, mitochondrial outer membrane permeabilisation or MOMP represents the defining event that irrevocably commits a cell to die. We provide an overview of how this pathway is regulated by BCL-2 family proteins and describe ways in which cancer cells can block it. Finally, we discuss exciting new approaches aimed at specifically inducing mitochondrial apoptosis in cancer cells, outlining their potential pitfalls, while highlighting their considerable therapeutic promise. PMID:25742467

  13. Role of the nucleus in apoptosis: signaling and execution.

    PubMed

    Prokhorova, Evgeniia A; Zamaraev, Alexey V; Kopeina, Gelina S; Zhivotovsky, Boris; Lavrik, Inna N

    2015-12-01

    Since their establishment in the early 1970s, the nuclear changes upon apoptosis induction, such as the condensation of chromatin, disassembly of nuclear scaffold proteins and degradation of DNA, were, and still are, considered as the essential steps and hallmarks of apoptosis. These are the characteristics of the execution phase of apoptotic cell death. In addition, accumulating data clearly show that some nuclear events can lead to the induction of apoptosis. In particular, if DNA lesions resulting from deregulation during the cell cycle or DNA damage induced by chemotherapeutic drugs or viral infection cannot be efficiently eliminated, apoptotic mechanisms, which enable cellular transformation to be avoided, are activated in the nucleus. The functional heterogeneity of the nuclear organization allows the tight regulation of these signaling events that involve the movement of various nuclear proteins to other intracellular compartments (and vice versa) to initiate and govern apoptosis. Here, we discuss how these events are coordinated to execute apoptotic cell death. PMID:26346492

  14. Cracking the code of neuronal apoptosis and survival

    PubMed Central

    Cavallaro, S

    2015-01-01

    Neuronal apoptosis and survival are tightly controlled processes that regulate cell fate during the development of the central nervous system and its homeostasis throughout adulthood. A new study in primary cultures of cerebellar granule neurons identified common transcriptional cascades during rescue from apoptosis by insulin-like growth factor-1 (Igf1) and pituitary adenylyl cyclase-activating polypeptide (Pacap), thus suggesting the existence of a high degree of conservation of cell survival pathways. PMID:26539910

  15. Drug-Induced Reactivation of Apoptosis Abrogates HIV-1 Infection

    PubMed Central

    Hanauske-Abel, Hartmut M.; Saxena, Deepti; Palumbo, Paul E.; Hanauske, Axel-Rainer; Luchessi, Augusto D.; Cambiaghi, Tavane D.; Hoque, Mainul; Spino, Michael; Gandolfi, Darlene D'Alliessi; Heller, Debra S.; Singh, Sukhwinder; Park, Myung Hee; Cracchiolo, Bernadette M.; Tricta, Fernando; Connelly, John; Popowicz, Anthony M.; Cone, Richard A.; Holland, Bart; Pe’ery, Tsafi; Mathews, Michael B.

    2013-01-01

    HIV-1 blocks apoptosis, programmed cell death, an innate defense of cells against viral invasion. However, apoptosis can be selectively reactivated in HIV-infected cells by chemical agents that interfere with HIV-1 gene expression. We studied two globally used medicines, the topical antifungal ciclopirox and the iron chelator deferiprone, for their effect on apoptosis in HIV-infected H9 cells and in peripheral blood mononuclear cells infected with clinical HIV-1 isolates. Both medicines activated apoptosis preferentially in HIV-infected cells, suggesting that the drugs mediate escape from the viral suppression of defensive apoptosis. In infected H9 cells, ciclopirox and deferiprone enhanced mitochondrial membrane depolarization, initiating the intrinsic pathway of apoptosis to execution, as evidenced by caspase-3 activation, poly(ADP-ribose) polymerase proteolysis, DNA degradation, and apoptotic cell morphology. In isolate-infected peripheral blood mononuclear cells, ciclopirox collapsed HIV-1 production to the limit of viral protein and RNA detection. Despite prolonged monotherapy, ciclopirox did not elicit breakthrough. No viral re-emergence was observed even 12 weeks after drug cessation, suggesting elimination of the proviral reservoir. Tests in mice predictive for cytotoxicity to human epithelia did not detect tissue damage or activation of apoptosis at a ciclopirox concentration that exceeded by orders of magnitude the concentration causing death of infected cells. We infer that ciclopirox and deferiprone act via therapeutic reclamation of apoptotic proficiency (TRAP) in HIV-infected cells and trigger their preferential elimination. Perturbations in viral protein expression suggest that the antiretroviral activity of both drugs stems from their ability to inhibit hydroxylation of cellular proteins essential for apoptosis and for viral infection, exemplified by eIF5A. Our findings identify ciclopirox and deferiprone as prototypes of selectively cytocidal antivirals that eliminate viral infection by destroying infected cells. A drug-based drug discovery program, based on these compounds, is warranted to determine the potential of such agents in clinical trials of HIV-infected patients. PMID:24086341

  16. Atovaquone derivatives as potent cytotoxic and apoptosis inducing agents.

    PubMed

    Zhou, Jing; Duan, Lei; Chen, Huaming; Ren, Xiaomei; Zhang, Zhang; Zhou, Fengtao; Liu, Jinsong; Pei, Duanqing; Ding, Ke

    2009-09-01

    2-Piperazinyl naphthoquinones (2) and 2-piperidinyl naphthoquinones (3) were designed and synthesized as new cytotoxic and apoptosis inducing agents by utilizing the anti-parasite drug atovaquone as lead compound. Several compounds displayed significantly improved cytotoxic activities against a panel of cancer cell lines than that of atovaquone. These compounds also induced apoptosis through activating pro-apoptotic caspases 9 and 3. PMID:19632833

  17. 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.

  18. Accelerated Apoptosis of Neutrophils in Familial Mediterranean Fever

    PubMed Central

    Manukyan, Gayane; Aminov, Rustam; Hakobyan, Gagik; Davtyan, Tigran

    2015-01-01

    The causative mutations for familial Mediterranean fever (FMF) are located in the MEFV gene, which encodes pyrin. Pyrin modulates the susceptibility to apoptosis via its PYD domain, but how the mutated versions of pyrin affect apoptotic processes are poorly understood. Spontaneous and induced rates of systemic neutrophil apoptosis as well as the levels of proteins involved in apoptosis were investigated ex vivo in patients with FMF using flow cytometry and RT-qPCR. The freshly collected neutrophils from the patients in FMF remission displayed a significantly larger number of cells spontaneously entering apoptosis compared to control (6.27?±?2.14 vs. 1.69?±?0.18%). This elevated ratio was retained after 24?h incubation of neutrophils in the growth medium (32.4?±?7.41 vs. 7.65?±?1.32%). Correspondingly, the mRNA level for caspase-3 was also significantly increased under these conditions. In response to the inducing agents, the neutrophils from FMF patients also displayed significantly elevated apoptotic rates compared to control. The elevated rates, however, can be largely explained by the higher basal ratio of apoptotic cells in the former group. Monitoring of several proteins involved in apoptosis has not revealed any conventional mechanisms contributing to the enhanced apoptotic rate of neutrophils in FMF. Although the exact molecular mechanisms of accelerated neutrophil apoptosis in FMF remain unknown, it may provide a protection against excessive inflammation and tissue damage due to a massive infiltration of neutrophils in the acute period of the disease. PMID:26042122

  19. Inhibition of apoptosis prevents West Nile virus induced cell death

    PubMed Central

    Kleinschmidt, Malte C; Michaelis, Martin; Ogbomo, Henry; Doerr, Hans-Wilhelm; Cinatl, Jindrich

    2007-01-01

    Background West Nile virus (WNV) infection can cause severe meningitis and encephalitis in humans. Apoptosis was recently shown to contribute to the pathogenesis of WNV encephalitis. Here, we used WNV-infected glioma cells to study WNV-replication and WNV-induced apoptosis in human brain-derived cells. Results T98G cells are highly permissive for lytic WNV-infection as demonstrated by the production of infectious virus titre and the development of a characteristic cytopathic effect. WNV replication decreased cell viability and induced apoptosis as indicated by the activation of the effector caspase-3, the initiator caspases-8 and -9, poly(ADP-ribose)polymerase (PARP) cleavage and the release of cytochrome c from the mitochondria. Truncation of BID indicated cross-talk between the extrinsic and intrinsic apoptotic pathways. Inhibition of the caspases-8 or -9 inhibited PARP cleavage, demonstrating that both caspases are involved in WNV-induced apoptosis. Pan-caspase inhibition prevented WNV-induced apoptosis without affecting virus replication. Conclusion We found that WNV infection induces cell death in the brain-derived tumour cell line T98G by apoptosis under involvement of constituents of the extrinsic as well as the intrinsic apoptotic pathways. Our results illuminate the molecular mechanism of WNV-induced neural cell death. PMID:17535425

  20. Androgens selectively protect against apoptosis in hippocampal neurones

    PubMed Central

    Nguyen, Thuy-Vi V.; Jayaraman, Anusha; Quaglino, Allison; Pike, Christian J.

    2010-01-01

    Androgens can protect neurones from injury, but androgen neuroprotection is not well characterised in terms of either specificity or mechanism. Here, we compared the ability of androgens to protect neurones against a panel of insults, empirically determined to induce cell death by apoptotic or non-apoptotic mechanisms. Three criteria defining, but not inclusive of apoptosis are: protection by caspase inhibition, protection by protein synthesis inhibition, and presence of pyknotic nuclei. According to these criteria, ?-amyloid, staurosporine, and Apoptosis Activator II induced cell death involving apoptosis, while hydrogen peroxide (H2O2), iron, calcium ionophore, and 3-nitropropionic acid induced cell death featuring non-apoptotic characteristics. Pretreatment of hippocampal neurones with testosterone or dihydrotestosterone attenuated cell death induced by ?-amyloid, staurosporine, and Apoptosis Activator II, but none of the other insults. The anti-oxidant Trolox did not reduce cell death induced by ?-amyloid, staurosporine, and Apoptosis Activator II, but did protect against H2O2 and iron. Similarly, a supra-physiological concentration of oestrogen reduced cell death induced by H2O2 and iron, an effect not observed with androgens. We also show that activation of oestrogen pathways was not necessary for androgen neuroprotection. These data suggest that androgens directly activate a neuroprotective mechanism specific to inhibition of cell death involving apoptosis. Determining the specificity of androgen neuroprotection may enable the development of androgen compounds for the treatment of neurodegenerative disorders. PMID:20561156

  1. Pathways Involved in Interleukin-1?–Mediated Murine Cardiomyocyte Apoptosis

    PubMed Central

    Shen, Yi; Qin, Jie

    2015-01-01

    Accumulating evidence suggests that interleukin-1 (IL-1) signaling plays an essential role in the pathogenesis of heart failure by inducing cardiomyocyte apoptosis, but the mechanisms of this process are poorly defined. We further explored these molecular pathways. We isolated cardiomyocytes from neonatal mice and then cultured and stimulated them with murine IL-1? in vitro. Cell apoptotic ratios were measured by means of flow cytometry. Expression of effector molecules was analyzed by means of enzyme-linked immunosorbent assay, Western blotting, and real-time quantitative polymerase chain reaction. The results showed that IL-1? induced murine cardiomyocyte apoptosis through a release of cytochrome c into cytoplasm and through caspase 3 activation. Simultaneously, IL-1? signaling promoted expression of endonuclease G and high-temperature requirement protein A2 messenger RNA. Survivin and X-linked inhibitors of apoptosis protein (IAP), members of the IAP family, were inhibited on the messenger RNA level during IL-1?–mediated cardiomyocyte apoptosis. We found that IL-1? signaling during cardiomyocyte apoptosis in vitro induced the activation of caspase-dependent and caspase-independent pathways, and inhibited IAPs. Understanding the molecular mechanisms involved in IL-1?–mediated cardiomyocyte apoptosis might assist in the design of therapeutic approaches to protect cardiomyocyte function and prevent heart failure. PMID:25873819

  2. Spaceflight alters microtubules and increases apoptosis in human lymphocytes (Jurkat)

    NASA Technical Reports Server (NTRS)

    Lewis, M. L.; Reynolds, J. L.; Cubano, L. A.; Hatton, J. P.; Lawless, B. D.; Piepmeier, E. H.

    1998-01-01

    Alteration in cytoskeletal organization appears to underlie mechanisms of gravity sensitivity in space-flown cells. Human T lymphoblastoid cells (Jurkat) were flown on the Space Shuttle to test the hypothesis that growth responsiveness is associated with microtubule anomalies and mediated by apoptosis. Cell growth was stimulated in microgravity by increasing serum concentration. After 4 and 48 h, cells filtered from medium were fixed with formalin. Post-flight, confocal microscopy revealed diffuse, shortened microtubules extending from poorly defined microtubule organizing centers (MTOCs). In comparable ground controls, discrete microtubule filaments radiated from organized MTOCs and branched toward the cell membrane. At 4 h, 30% of flown, compared to 17% of ground, cells showed DNA condensation characteristic of apoptosis. Time-dependent increase of the apoptosis-associated Fas/ APO-1 protein in static flown, but not the in-flight 1 g centrifuged or ground controls, confirmed microgravity-associated apoptosis. By 48 h, ground cultures had increased by 40%. Flown populations did not increase, though some cells were cycling and actively metabolizing glucose. We conclude that cytoskeletal alteration, growth retardation, and metabolic changes in space-flown lymphocytes are concomitant with increased apoptosis and time-dependent elevation of Fas/APO-1 protein. We suggest that reduced growth response in lymphocytes during spaceflight is linked to apoptosis.

  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 (??m) was evaluated using confocal microscopy imaging and flow cytometry (FCM). H2O2 treatment induced a marked reduction of ??m, and the abrupt disappearance of ??m occurred within 5 minutes. These results indicate that H2O2 induces a rapid apoptosis via a mitochondrial pathway in rabbit chondrocytes.

  4. Inhibition of mouse hepatocyte apoptosis via anti-Fas ribozyme

    PubMed Central

    Zhang, Min; He, Wei; Liu, Fang; Zou, Ping; Xiao, Juan; Zhong, Zhao-Dong; Hu, Zhong-Bo

    2004-01-01

    AIM: To investigate the effects of anti-Fas ribozyme on Fas expression and apoptosis in primary cultured mouse hepatocytes. METHODS: Mouse hepatocytes were isolated by using collagenase irrigation. A hammerhead ribozyme targeting the Fas mRNA was constructed, and transfected into mouse hepatocytes via Effectene. Then Fas expression in mouse hepatocytes was detected by RT-PCR and western blotting. After being treated with anti-Fas antibody (JO2), hepatocytes viability was measured with MTT assay. Caspase-3 proteolytic activity was detected, and cell apoptosis was measured according to Annexin V-FITC apoptosis detection kit. RESULTS: Fas expressed in primary mouse hepatocytes. Fas expression in hepatocytes transfected with anti-Fas ribozyme was decreased remarkably and correlated with the resistance to Fas-mediated apoptosis as determined by flow cytometry and caspase-3 proteolytic activity. CONCLUSION: Anti-Fas ribozyme can remarkably decrease the Fas expression in mouse hepatocytes, thus inhibit Fas-mediated apoptosis in hepatocytes. It is suggested that anti-Fas ribozyme could significantly increase the resistance of transplanted hepatocytes to apoptosis and improve the survival of transplanted hepatocytes. PMID:15300908

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

    PubMed

    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

  6. 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

  7. 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

  8. Thiol-mediated redox regulation of apoptosis. Possible roles of cellular thiols other than glutathione in T cell apoptosis.

    PubMed

    Sato, N; Iwata, S; Nakamura, K; Hori, T; Mori, K; Yodoi, J

    1995-04-01

    Thiol redox status modulates various aspects of cellular function. We demonstrate that oxidation of cellular sulfhydryl (SH) groups induces apoptosis. In Jurkat T cells and human PBL blasts, the fraction of apoptotic nuclei increased after treatment with an SH-specific oxidant, diamide. Analysis of DNA fragmentation and nuclear morphology also indicated that SH oxidation could induce apoptosis. In the apoptosis induced by SH oxidation, the decrease of cellular glutathione was transient and the increase of glutathione disulfide was observed only after apoptotic changes had occurred. Depletion of cellular glutathione with buthionine sulfoximine failed to induce apoptosis, despite a marked decrease of cellular glutathione, which was greater than that observed in apoptosis induced by diamide. Thus, the changes of cellular glutathione or glutathione disulfide may not be the major cause of apoptosis induced by diamide. Intracellular adult T cell leukemia-derived factor/human thioredoxin, another thiol-related antioxidant protein, was oxidized by incubation with diamide. These results suggest that thiol redox status is one of the key factors of the apoptotic pathway in which thiols other than glutathione may play even more critical roles. PMID:7897207

  9. Increased expression of cytokines, soluble cytokine receptors, soluble apoptosis ligand and apoptosis in dengue.

    PubMed

    Arias, Julia; Valero, Nereida; Mosquera, Jesús; Montiel, Milagros; Reyes, Eduardo; Larreal, Yraima; Alvarez-Mon, Melchor

    2014-03-01

    Several studies have been performed to determine biomarkers that define the risk factors to developing severe forms of dengue. In this study, the levels of TNF-?, IL-6, IL-1, IL-17, soluble interleukin-1 receptor like 1 protein (sST2), soluble TNF-related apoptosis-inducing ligand (sTRAIL), IL-12 and soluble receptors for TNF (sTNF-RI and sTNF-RII) were determined by ELISA in dengue patients and monocyte/macrophage cultures. Dengue was classified as dengue without warning symptoms (DNWS), with warning symptoms (DWWS) and severe dengue (SD). High values of IL-6, sTNFRI, sTNFRII and sST2 were observed in DWWS and/or SD and IL-12 and sTRAIL in DNWS. TNF-? and IL-17 were increased not associated to the disease severity. High production of TNF-?, IL-1?, IL-12, IL-17, sST2 and sTRAIL and apoptosis expression were observed in dengue monocyte/macrophage cultures. This study shows that beneficial or deleterious biomarkers can be present in dengue regardless the disease severity and that monocytes may be in part the source of studied molecules. PMID:24606681

  10. Natural Killer Cells Induce Eosinophil Activation and Apoptosis

    PubMed Central

    Awad, Ali; Yassine, Hanane; Barrier, Mathieu; Vorng, Han; Marquillies, Philippe; Tsicopoulos, Anne; Duez, Catherine

    2014-01-01

    Eosinophils are potent inflammatory cells with numerous immune functions, including antigen presentation and exacerbation of inflammatory responses through their capacity to release a range of largely preformed cytokines and lipid mediators. Thus, timely regulation of eosinophil activation and apoptosis is crucial to develop beneficial immune response and to avoid tissue damage and induce resolution of inflammation. Natural Killer (NK) cells have been reported to influence innate and adaptive immune responses by multiple mechanisms including cytotoxicity against other immune cells. In this study, we analyzed the effect of the interaction between NK cells and eosinophils. Co-culture experiments revealed that human NK cells could trigger autologous eosinophil activation, as shown by up-regulation of CD69 and down-regulation of CD62L, as well as degranulation, evidenced by increased CD63 surface expression, secretion of eosinophil cationic protein (ECP) and eosinophil derived neurotoxin (EDN). Moreover, NK cells significantly and dose dependently increased eosinophil apoptosis as shown by annexin V and propidium iodide (PI) staining. Direct contact was necessary for eosinophil degranulation and apoptosis. Increased expression of phosphorylated extracellular signal-regulated kinase (ERK) in cocultured eosinophils and inhibition of eosinophil CD63 expression by pharmacologic inhibitors suggest that MAPK and PI3K pathways are involved in NK cell-induced eosinophil degranulation. Finally, we showed that NK cells increased reactive oxygen species (ROS) expression by eosinophils in co-culture and that mitochondrial inhibitors (rotenone and antimycin) partially diminished NK cell-induced eosinophil apoptosis, suggesting the implication of mitochondrial ROS in NK cell-induced eosinophil apoptosis. Pan-caspase inhibitor (ZVAD-FMK) only slightly decreased eosinophil apoptosis in coculture. Altogether, our results suggest that NK cells regulate eosinophil functions by inducing their activation and their apoptosis. PMID:24727794

  11. A novel factor, Tmem176b, induced by activin-like kinase 2 signal promotes the differentiation of myoblasts into osteoblasts.

    PubMed

    Yano, M; Kawao, N; Tamura, Y; Okada, K; Kaji, H

    2014-01-01

    Previous studies have suggested some interactions between muscle tissues and bone metabolism. The constitutively activating mutation (R206H) of the BMP type I receptor, activin-like-kinase 2 (ALK2), causes fibrodysplasia ossificans progressiva (FOP), which is characterized by extensive ossifications within muscle tissues. In the present study, we revealed that Tmem176b mRNA levels were upregulated by stable transfection of ALK2 (R206H) in mouse myoblastic C2C12 cells. Transient Tmem176b overexpression elevated levels of osteoblast differentiation markers, such as Osterix and alkaline phosphatase, as well as mineralization in C2C12 cells. In addition, Tmem176b overexpression elevated the levels of these markers in mouse osteoblastic MC3T3-E1 cells. On the other hand, Tmem176b overexpression suppressed the levels of myogenic markers, such as MyoD and myogenin in C2C12 cells, although it did not affect the levels of chondrogenic markers, such as type II and X collagens. In conclusion, the present study is the first to demonstrate that Tmem176b induces the differentiation of myoblasts into an osteoblast lineage. PMID:24085390

  12. Mst1 inhibition rescues ?1-adrenergic cardiomyopathy by reducing myocyte necrosis and non-myocyte apoptosis rather than myocyte apoptosis.

    PubMed

    Lee, Grace J; Yan, Lin; Vatner, Dorothy E; Vatner, Stephen F

    2015-03-01

    It is generally held that inhibition of mammalian sterile 20-like kinase 1 (Mst1) protects the heart through reducing myocyte apoptosis. We determined whether inhibition with a dominant-negative Mst1 (DN-Mst1) would protect against the cardiomyopathy induced by chronic ?1-adrenergic receptor (?1-AR) stimulation by preventing myocyte apoptosis. DN-Mst1 mice were mated with ?1-AR transgenic (Tg) mice and followed for 20 months. ?1-AR Tg mice developed cardiomyopathy as they aged, as reflected by premature mortality and depressed cardiac function, which were rescued in ?1-AR × DN-Mst1 bigenic mice. Surprisingly, myocyte apoptosis did not significantly decrease with Mst1 inhibition. Instead, Mst1 inhibition predominantly reduced non-myocyte apoptosis, e.g., fibroblasts, macrophages, neutrophils and endothelial cells. Fibrosis in the hearts with cardiomyopathy increased fivefold and this increase was nearly abolished in the bigenic mice with Mst1 inhibition. Regression analysis showed no correlation between myocyte apoptosis and cardiac function or myocyte number, whereas the latter two correlated significantly, p < 0.05, with fibrosis, which generally results from necrosis. To examine the role of myocyte necrosis, chronic ?-AR stimulation with isoproterenol was induced for 24 h and myocyte necrosis was assessed by 1% Evans blue dye. Compared to WT, DN-Mst1 mice showed significant inhibition, p < 0.05, of myocyte necrosis. We confirmed this result in Mst1-knockout mice, which also showed significant protection, p < 0.05, against myocyte necrosis compared to WT. These data indicate that Mst1 inhibition rescued cardiac fibrosis and myocardial dysfunction in ?1-AR cardiomyopathy. However, this did not occur through Mst1 inhibition of myocyte apoptosis but rather by inhibition of cardiomyocyte necrosis and non-myocyte apoptosis, features of Mst1 not considered previously. PMID:25600225

  13. 1 S.R. REEVES, D.G. HILL, R.L. TINER, P.A. BASTIAN, M.W. CONWAY & S. MOHAGHEGH SPE 55627 Copyright 1999, Society of Petroleum Engineers Inc.

    E-print Network

    Mohaghegh, Shahab

    1999, Society of Petroleum Engineers Inc. This paper was prepared for presentation at the 1999 SPE by the author(s). Contents of the paper, as presented, have not been reviewed by the Society of Petroleum reflect any position of the Society of Petroleum Engineers, its officers, or members. Papers presented

  14. spe424-01 23 pages Thomas, E., 2007, Cenozoic mass extinctions in the deep sea: What perturbs the largest habitat on Earth?, in Monechi, S., Coccioni, R., and Rampino, M.R., eds.,

    E-print Network

    Thomas, Ellen

    spe424-01 23 pages 1 Thomas, E., 2007, Cenozoic mass extinctions in the deep sea: What perturbs reserved. The Geological Society of America Special Paper 424 2007 Cenozoic mass extinctions in the deep.e., rapid global warming. Cenozoic deep-sea benthic faunas show gradual faunal turnover during periods

  15. spe433-02 page 27 Ernst, W.G., Hacker, B.R., and Liou, J.G., 2007, Petrotectonics of ultrahigh-pressure crustal and upper-mantle rocks--Implications for Phanerozoic collisional

    E-print Network

    Hacker, Bradley R.

    spe433-02 page 27 27 Ernst, W.G., Hacker, B.R., and Liou, J.G., 2007, Petrotectonics of ultrahigh of Geological and Environmental Sciences, Stanford University, Stanford, California 94305-2115, USA B.R. Hacker

  16. Determination of analytes in medical herbs extracts by SPE coupled with two-dimensional planar chromatography in combination with diode array scanning densitometry and HPLC-diode array detector.

    PubMed

    Tuzimski, Tomasz

    2011-01-01

    The purpose of this study is to demonstrate an application of 2-D high-performance planar chromatography-diode array detector (DAD) and HPLC-DAD after solid-phase extraction (SPE) for identification and quantitative analysis of pesticides (isoproturon, aziprotryne, hexazinone, flufenoxuron, methabenzthiazuron, procymidone, and ?-cypermethrin) in Melissa officinalis L. (Labiatae) samples. The procedure described for the determination of compounds is inexpensive and can be applied to routine analysis of analytes in medical herbs' samples after preliminary cleanup and concentration by SPE. Average recoveries on C18 SPE cartridges of pesticides eluted with 5 mL tetrahydrofuran by the proposed HPLC-DAD method, before and after 2-D-high-performance planar chromatography separation of analytes from M. officinalis L. samples spiked with pesticide at a concentration level of 10 ?g/g in plant material are presented. Method validation parameters for the quantification of pesticides by the proposed HPLC-DAD after SPE method are also presented. PMID:21171173

  17. SPE Combined with HPLC-APCI-MS Analysis of Pesticides in Water: Method Performance and Application in a Reconnaissance Survey of Residues in Drinking Water in Greater Cairo (Egypt)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The portability, ease of use, and potential to enhance analyte stability makes solid-phase extraction (SPE) an attractive technique for extracting water samples collected for pesticide residue analysis prior to their shipment to analytical laboratories. The technique is especially valuable when samp...

  18. High-Throughput Quantitation of Busulfan in Plasma Using Ultrafast Solid-Phase Extraction Tandem Mass Spectrometry (SPE-MS/MS).

    PubMed

    Langman, Loralie J; Danso, Darlington; Robert, Enger; Jannetto, Paul J

    2016-01-01

    Busulfan is a commonly used antineoplastic agent to condition/ablate bone marrow cells before hematopoietic stem cell transplant. While intravenous (IV) formulations of busulfan are now available and have lower incidences of toxicity and treatment related mortality compared to oral dosing, it still displays large pharmacokinetic variability. As a result, studies have shown that therapeutic drug monitoring is clinically useful to minimize graft failure, disease reoccurrence, and toxicities like veno-occlusive disease and neurologic toxicity. Current methods for assaying busulfan include the use of GC/MS, HPLC, and LC-MS/MS. The clinical need for faster turnaround times and increased testing volumes has required laboratories to develop faster methods of analysis for higher throughput of samples. Therefore, we present a method for the quantification of busulfan in plasma using an ultrafast SPE-MS/MS which has much faster sample cycle times (<20 s per sample) and comparable analytical results to GC/MS. PMID:26660177

  19. Quantitation of Chloramphenicol and Nitrofuran Metabolites in Aquaculture Products Using Microwave-Assisted Derivatization, Automated SPE, and LC-MS/MS.

    PubMed

    Veach, Brian T; Baker, Chris A; Kibbey, John H; Fong, Andrew; Broadaway, Bryanna J; Drake, Connie P

    2015-01-01

    This paper describes a rapid and robust method utilizing microwave-assisted derivatization, automated SPE, and LC-MS/MS for the quantitation and confirmation of chloramphenicol (CAP) and nitrofuran metabolites in various aquaculture matrixes. The use of equipment presented in this work allowed extractions to be completed on average within 6 h, with quantitation accuracy ranging from 89 to 107% and RSD?8.3%. The demonstrated detection limits for all the nitrofuran metabolites of interest in three different matrixes were ?0.06 ng/g, with a quantitation limit of ?0.2 ng/g. Additionally, the method exhibited a CAP detection limit for all matrixes?0.01 ng/g and an LOQ of ?0.03 ng/g. PMID:26025616

  20. Bile acids: regulation of apoptosis by ursodeoxycholic acid

    PubMed Central

    Amaral, Joana D.; Viana, Ricardo J. S.; Ramalho, Rita M.; Steer, Clifford J.; Rodrigues, Cecília M. P.

    2009-01-01

    Bile acids are a group of molecular species of acidic steroids with peculiar physical-chemical and biological characteristics. At high concentrations they become toxic to mammalian cells, and their presence is pertinent in the pathogenesis of several liver diseases and colon cancer. Bile acid cytoxicity has been related to membrane damage, but also to nondetergent effects, such as oxidative stress and apoptosis. Strikingly, hydrophilic ursodeoxycholic acid (UDCA), and its taurine-conjugated form (TUDCA), show profound cytoprotective properties. Indeed, these molecules have been described as potent inhibitors of classic pathways of apoptosis, although their precise mode of action remains to be clarified. UDCA, originally used for cholesterol gallstone dissolution, is currently considered the first choice therapy for several forms of cholestatic syndromes. However, the beneficial effects of both UDCA and TUDCA have been tested in other experimental pathological conditions with deregulated levels of apoptosis, including neurological disorders, such as Alzheimer's, Parkinson's, and Huntington's diseases. Here, we review the role of bile acids in modulating the apoptosis process, emphasizing the anti-apoptotic effects of UDCA and TUDCA, as well as their potential use as novel and alternate therapeutic agents for the treatment of apoptosis-related diseases. PMID:19417220

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

    PubMed Central

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

    2014-01-01

    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. PMID:25356864

  2. Light scattering application for quantitative estimation of apoptosis

    NASA Astrophysics Data System (ADS)

    Bilyy, Rostyslav O.; Stoika, Rostyslav S.; Getman, Vasyl B.; Bilyi, Olexander I.

    2004-05-01

    Estimation of cell proliferation and apoptosis are in focus of instrumental methods used in modern biomedical sciences. Present study concerns monitoring of functional state of cells, specifically the development of their programmed death or apoptosis. The available methods for such purpose are either very expensive, or require time-consuming operations. Their specificity and sensitivity are frequently not sufficient for making conclusions which could be used in diagnostics or treatment monitoring. We propose a novel method for apoptosis measurement based on quantitative determination of cellular functional state taking into account their physical characteristics. This method uses the patented device -- laser microparticle analyser PRM-6 -- for analyzing light scattering by the microparticles, including cells. The method gives an opportunity for quick, quantitative, simple (without complicated preliminary cell processing) and relatively cheap measurement of apoptosis in cellular population. The elaborated method was used for studying apoptosis expression in murine leukemia cells of L1210 line and human lymphoblastic leukemia cells of K562 line. The results obtained by the proposed method permitted measuring cell number in tested sample, detecting and quantitative characterization of functional state of cells, particularly measuring the ratio of the apoptotic cells in suspension.

  3. ?–blockade, apoptosis, and prostate shrinkage: how are they related?

    PubMed Central

    Ch?osta, Piotr; Kaplan, Steven

    2013-01-01

    Purpose The ?1–adrenoreceptor antagonists, such as terazosin and doxazosin, induce prostate programmed cell death (apoptosis) within prostate epithelial and stromal cells in vitro. This treatment should cause prostate volume decrease, However, this has never been observed in clinical conditions. The aim of this paper is to review the disconnect between these two processes. Methods PubMed and DOAJ were searched for papers related to prostate, apoptosis, and stem cell death. The following key words were used: prostate, benign prostate hyperplasia, programmed cell death, apoptosis, cell death, ?1–adrenoreceptor antagonist, ?–blockade, prostate epithelium, prostate stroma, stem cells, progenitors, and in vitro models. Results We have shown how discoveries related to stem cells can influence our understanding of ?–blockade treatment for BPH patients. Prostate epithelial and mesenchymal compartments have stem (progenitors) and differentiating cells. These compartments are described in relation to experimental in vitro and in vivo settings. Conclusions Apoptosis is observed within prostate tissue, but this effect has no clinical significance and cannot lead to prostate shrinkage. In part, this is due to stem cells that are responsible for prostate tissue regeneration and are resistant to apoptosis triggered by ?1–receptor antagonists. PMID:24579025

  4. Serine racemase: a key player in apoptosis and necrosis

    PubMed Central

    Canu, Nadia; Ciotti, Maria Teresa; Pollegioni, Loredano

    2014-01-01

    A fine balance between cell survival and cell death is required to sculpt the nervous system during development. However, an excess of cell death can occur following trauma, exposure to neurotoxins or alcohol, and some developmental and neurodegenerative diseases, such as Alzheimer's disease (AD). N-Methyl-D-aspartate receptors (NMDARs) support synaptic plasticity and survival of many neuronal populations whereas inappropriate activation may promote various forms of cell death, apoptosis, and necrosis representing the two extremes of a continuum of cell death processes both “in vitro” and “in vivo.” Hence, by identifying the switches controlling pro-survival vs. apoptosis and apoptosis vs. pro-excitotoxic outcome of NMDAR stimulation, NMDAR modulators could be developed that selectively block the cell death enhancing pro-survival signaling or synaptic plasticity mediated by NMDAR. Among these modulators, a role is emerging for the enzyme serine racemase (SR) that synthesizes D-serine, a key co-agonist with glutamate at NMDAR. This review summarizes the experimental evidence from “in vitro” neuronal cultures—with special emphasis on cerebellar granule neurons (CGNs)—and “in vivo” models of neurodegeneration, where the dual role of the SR/D-serine pathway as a master regulator of apoptosis and the apoptosis-necrosis shift will be discussed. PMID:24795622

  5. Inhibition of dendritic cell apoptosis by Leishmania mexicana amastigotes.

    PubMed

    Gutiérrez-Kobeh, Laila; de Oyarzabal, Eleané; Argueta, Jesús; Wilkins, Arturo; Salaiza, Norma; Fernández, Edith; López, Oliver; Aguirre, Magdalena; Becker, Ingeborg

    2013-04-01

    Macrophages (M?) and dendritic cells are the major target cell populations of the obligate intracellular parasite Leishmania. Inhibition of host cell apoptosis is a strategy employed by multiple pathogens to ensure their survival in the infected cell. Leishmania promastigotes have been shown to protect M?, neutrophils, and dendritic cells from both natural and induced apoptosis. Nevertheless, the effect of the infection with Leishmania amastigotes in the apoptosis of these cell populations has not been established, which results are very important since amastigotes persist in cells for many days and are responsible for sustaining infection in the host. As shown in this study, apoptosis of monocyte-derived dendritic cells (moDC) induced by treatment with camptothecin was downregulated by infection with L. mexicana amastigotes from 42.48 to 36.92% as detected by Annexin-V binding to phosphatidylserine. Also, the infection of moDC with L. mexicana amastigotes diminished the fragmentation of DNA as detected by terminal deoxynucleotidyl transferase-mediated fluorescein-dUTP nick end labeling assay, and changes in cell morphology were analyzed by electron microscopy. The observed antiapoptotic effect was found to be associated with an 80% reduction in the presence of active caspase-3 in infected moDC. The capacity of L. mexicana amastigotes to delay apoptosis induction in the infected moDC may have implications for Leishmania pathogenesis by favoring the invasion of its host and the persistence of the parasite in the infected cells. PMID:23420408

  6. 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) ? radiation can initiate this pathway, independent of DNA damage, via the cell membrane. Whether short-ranged, high-LET ? 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 ? particles emitted by the ²²?Ac-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 ?-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 ? particles using a planar ²?¹Am 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 ?-particle traversals per cell. These data indicate that ? particles can activate the sphingomyelin pathway to induce apoptosis. PMID:21631289

  7. HSP70 inhibits Bax translocation during Photofrin-PDT apoptosis

    NASA Astrophysics Data System (ADS)

    Zhou, Feifan; Chen, Wei R.; Song, Sheng

    2009-02-01

    Apoptosis is an important cellular event that plays a key role in therapy of many diseases. The mechanisms of the initiation and regulation of photodynamic therapy (PDT) -induced apoptosis is complex. Some PDT-associated apoptosis pathways involved plasma membrane death receptors, mitochondria, lysosomes and endoplasmic reticulum (ER). Our previous study found that Photofrin were localized primarily in mitochondria, the primary targets of Photofrin-PDT. The key role of Bax in the mitochondrion-mediated apoptosis has been demonstrated in many systems. In order to determine the role of Bax in the mitochondrion-mediated apoptosis induced by Photofrin-PDT, we used the CFP/GFP-Bax plasmid to monitor the dynamics of Bax activation and translocation after PDT treatment. With laser scanning confocal microscopy, we found that PDT induced Bax translocation from the cytosol to mitochondria; however, with cells over-expressing YFP-HSP70 plasmids, Bax translocation was not detected. Thus, for Photofrin-PDT, Bax activation and translocation were inhibited by HSP70, not influence the cell death.

  8. Interaction between glutathione and Apoptosis in Systemic Lupus Erythematosus

    PubMed Central

    Shah, Dilip; Sah, Sangita; Nath, Swapan K.

    2013-01-01

    Systemic lupus erythematosus (SLE) is characterized by imbalance redox state and increased apoptosis. The activation, proliferation and cell death of lymphocytes are dependent on intracellular levels of glutathione and controlled production of reactive oxygen species (ROS). Changes in the intracellular redox environment of cells, through oxygen-derived free radical production known as oxidative stress, have been reported to be critical for cellular immune dysfunction, activation of apoptotic enzymes and apoptosis. The shift in the cellular GSH-to-GSSG redox balance in favor of the oxidized species, GSSG, constitutes an important signal that can decide the fate of the abnormal apoptosis in the disease. The current review will focus on four main areas: (1) general description of oxidative stress markers in SLE, (2) alteration of redox state and complication of disease (3) role of redox mechanisms in the initiation and execution phases of apoptosis, and (4) intracellular glutathione and its checkpoints with lymphocyte apoptosis represent novel targets for pharmacological intervention in SLE. PMID:23279845

  9. Modeling the TNF?-Induced Apoptosis Pathway in Hepatocytes

    PubMed Central

    Lutz, Anna; Trefzger, Judith; Sawodny, Oliver; Ederer, Michael; Merfort, Irmgard

    2011-01-01

    The proinflammatory cytokine TNF? fails to provoke cell death in isolated hepatocytes but has been implicated in hepatocyte apoptosis during liver diseases associated with chronic inflammation. Recently, we showed that TNF? is able to sensitize primary murine hepatocytes cultured on collagen to Fas ligand-induced apoptosis and presented a mathematical model of the sensitizing effect. Here, we analyze how TNF? induces apoptosis in combination with the transcriptional inhibitor actinomycin D (ActD). Accumulation of reactive oxygen species (ROS) in response to TNFR activation turns out to be critical for sustained activation of JNK which then triggers mitochondrial pathway-dependent apoptosis. In addition, the amount of JNK is strongly upregulated in a ROS-dependent way. In contrast to TNF? plus cycloheximide no cFLIP degradation is observed suggesting a different apoptosis pathway in which the Itch-mediated cFLIP degradation and predominantly caspase-8 activation is not involved. Time-resolved data of the respective pro- and antiapoptotic factors are obtained and subjected to mathematical modeling. On the basis of these data we developed a mathematical model which reproduces the complex interplay regulating the phosphorylation status of JNK and generation of ROS. This model was fully integrated with our model of TNF?/Fas ligand sensitizing as well as with a published NF-?B-model. The resulting comprehensive model delivers insight in the dynamical interplay between the TNF? and FasL pathways, NF-?B and ROS and gives an example for successful model integration. PMID:21533085

  10. Outcompeting GC for the detection of legacy chlorinated pesticides: online-SPE UPLC APCI/MSMS detection of endosulfans at part per trillion levels.

    PubMed

    Quinete, Natalia; Wang, Jian; Fernandez, Adolfo; Castro, Joffre; Gardinali, Piero R

    2013-07-01

    Endosulfan, the last remaining organochlorine pesticide, has been the subject of a number of international regulations and restriction/banning action plans worldwide. Occurrence of endosulfan residues in South Florida environments has been widely described in the literature for more than two decades. This work describes a selective, sensitive, and fast online solid-phase extraction (SPE) method coupled with liquid chromatography separation and tandem mass spectrometry (LC-MS/MS) for the determination of endosulfan isomers and endosulfan sulfate in water samples at low part per trillion levels with very little sample preparation. A negative atmospheric pressure chemical ionization source was carefully optimized to produce reproducible spectra of the target compounds with no adduct ion formation. Selected reaction monitoring transitions were monitored and quantitation was performed against a per-deuterated internal standard ?-endosulfan (d4). The automated online SPE clean-up was performed using only 20 mL of untreated water sample prior to LC-MS/MS analysis. The method was capable of separating and quantifying endosulfan within a 24-min run using acetonitrile and water as mobile phases and presenting statistically calculated method detection limits of 3, 10, and 7 ng/L for endosulfan sulfate, ?-endosulfan, and ?-endosulfan, respectively. In addition, a QuEChERS method was successfully developed and applied for endosulfan determination in sediments/soils, floating and submerged algal mats, and small fish. Minimal matrix effects were observed in all matrices analyzed and recoveries for all analytes ranged from 50-144 %. The developed methodology was applied to monitor the occurrence and to assess the potential transport of endosulfan in the Loveland Slough watershed, an area adjacent to Everglades National Park showing long-term contamination with endosulfans. PMID:23386002

  11. Monitoring cell growth, viability, and apoptosis.

    PubMed

    Butler, Michael; Spearman, Maureen; Braasch, Katrin

    2014-01-01

    The accurate determination of cell growth and viability is pivotal to monitoring a bioprocess. Direct methods to determine the cell growth and/or viability in a bioprocess include microscopic counting, electronic particle counting, image analysis, in situ biomass monitoring, and dieletrophoretic cytometry. These methods work most simply when a fixed volume sample can be taken from a suspension culture. Manual microscopic counting is laborious but affords the advantage of allowing cell viability to be determined if a suitable dye is included. Electronic particle counting is a rapid total cell count method for replicate samples, but some data distortion may occur if the sample has significant cell debris or cell aggregates. Image analysis based on the use of digital camera images acquired through a microscope has advanced rapidly with the availability of several commercially available software packages replacing manual microscopic counting and viability determination. Biomass probes detect cells by their dielectric properties or their internal concentration of NADH and can be used as a continuous monitor of the progress of a culture. While the monitoring of cell growth and viability is an integral part of a bioprocess, the monitoring of apoptosis induction is also becoming more and more important in bioprocess control to increase volumetric productivity by extending bioprocess duration. Different fluorescent assays allow for the detection of apoptotic characteristics in a cell sample.Indirect methods of cell determination involve the chemical analysis of a culture component or a measure of metabolic activity. These methods are most useful when it is difficult to obtain intact cell samples. However, the relationship between these parameters and the cell number may not be linear through the phases of a cell culture. The determination of nucleic acid (DNA) or total protein can be used as an estimate of biomass, while the depletion of glucose from the media can be used as an estimate of cellular activity. The state of cellular viability may be measured by the release of an enzyme such as lactate dehydrogenase or more directly from the intracellular adenylate energy charge from cell lysates. Alternatively, radioactive techniques may be used for an accurate determination of cellular protein synthesis. PMID:24297416

  12. 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.

  13. Molecular Imaging of Apoptosis: From Micro to Macro

    PubMed Central

    Zeng, Wenbin; Wang, Xiaobo; Xu, Pengfei; Liu, Gang; Eden, Henry S.; Chen, Xiaoyuan

    2015-01-01

    Apoptosis, or programmed cell death, is involved in numerous human conditions including neurodegenerative diseases, ischemic damage, autoimmune disorders and many types of cancer, and is often confused with other types of cell death. Therefore strategies that enable visualized detection of apoptosis would be of enormous benefit in the clinic for diagnosis, patient management, and development of new therapies. In recent years, improved understanding of the apoptotic machinery and progress in imaging modalities have provided opportunities for researchers to formulate microscopic and macroscopic imaging strategies based on well-defined molecular markers and/or physiological features. Correspondingly, a large collection of apoptosis imaging probes and approaches have been documented in preclinical and clinical studies. In this review, we mainly discuss microscopic imaging assays and macroscopic imaging probes, ranging in complexity from simple attachments of reporter moieties to proteins that interact with apoptotic biomarkers, to rationally designed probes that target biochemical changes. Their clinical translation will also be our focus. PMID:25825597

  14. The influence of infectious factors on dendritic cell apoptosis

    PubMed Central

    Kubicka-Sierszen, Agata

    2015-01-01

    Pathogens can have a negative influence on dendritic cells (DCs), causing their apoptosis, which prevents active presentation of foreign antigens. It results in a state of immunosuppression which makes the body susceptible to secondary infections. Infected immature DCs have lower expression of co-stimulatory and adhesion molecules, reduced ability to secrete cytokines and an inhibited maturation process and are incapable of effective antigen presentation and activation of T-lymphocytes. In some cases, the ability of DCs to undergo rapid apoptosis is important for the body defense, which is probably because of DCs’ ability to cross-present and cooperate with other cells. Apoptotic bodies released from the infected DCs are phagocytosed by other DCs, which then stimulate the effector cells and present antigens more efficiently than infected cells. The aim of this article is to review how the DCs respond to viral and bacterial factors and which biochemical mechanisms are responsible for their apoptosis. PMID:26528349

  15. Lipopolysaccharide-induced apoptosis in swine lymphocytes in vivo.

    PubMed Central

    Norimatsu, M; Ono, T; Aoki, A; Ohishi, K; Takahashi, T; Watanabe, G; Taya, K; Sasamoto, S; Tamura, Y

    1995-01-01

    The in vivo effects of bacterial lipopolysaccharide (LPS) on the immune systems of piglets were investigated. Intravenous injection of 0.5 mg of LPS per kilogram of body weight induced apoptosis, which was characterized by nuclear chromatin condensation and fragmentation and a ladder formation of nucleosomal DNA in lymphocytes both in the cortex of the thymus and in the germinal centers and paracortical areas of mesenteric lymph nodes at 24 h postinjection. The levels of endotoxin, tumor necrosis factor alpha, and cortisol in serum increased, generally according to the dose of LPS. These findings suggest that LPS can induce in vivo apoptosis of lymphocytes in piglets and support the notion that cytokine and endocrine responses may play an important role in LPS-induced apoptosis in the immune system. PMID:7868236

  16. ATM promotes apoptosis and suppresses tumorigenesis in response to Myc

    NASA Astrophysics Data System (ADS)

    Pusapati, Raju V.; Rounbehler, Robert J.; Hong, Sungki; Powers, John T.; Yan, Mingshan; Kiguchi, Kaoru; McArthur, Mark J.; Wong, Paul K.; Johnson, David G.

    2006-01-01

    Overexpression of the c-myc oncogene contributes to the development of a significant number of human cancers. In response to deregulated Myc activity, the p53 tumor suppressor is activated to promote apoptosis and inhibit tumor formation. Here we demonstrate that p53 induction in response to Myc overexpression requires the ataxia-telangiectasia mutated (ATM) kinase, a major regulator of the cellular response to DNA double-strand breaks. In a transgenic mouse model overexpressing Myc in squamous epithelial tissues, inactivation of Atm suppresses apoptosis and accelerates tumorigenesis. Deregulated Myc expression induces DNA damage in primary transgenic keratinocytes and the formation of H2AX and phospho-SMC1 foci in transgenic tissue. These findings suggest that Myc overexpression causes DNA damage in vivo and that the ATM-dependent response to this damage is critical for p53 activation, apoptosis, and the suppression of tumor development. p53 | DNA damage

  17. Phenylephrine protects autotransplanted rabbit submandibular gland from apoptosis

    SciTech Connect

    Xiang Bin; Zhang Yan; Li Yuming; Gao Yan; Gan Yehua; Wu Liling Yu Guangyan

    2008-12-05

    Submandibular gland (SMG) autotransplantation is an effective treatment for severe keratoconjunctivitis sicca. Our previous studies have shown that phenylephrine attenuates structural injury and promotes cell proliferation in autotransplanted rabbit SMG. However, the mechanism by which phenylephrine reduces the injury has not been fully evaluated. In this study, we investigate the ability of phenylephrine to inhibit apoptosis in autotransplanted rabbit SMG. We observed that apoptosis occurred in the early phase of SMG transplantation and that phenylephrine treatment protected transplanted SMG from apoptosis. Furthermore, we found that phenylephrine could significantly upregulate the expression of Bcl-2, downregulate the expression of Bax, and inhibit the activation of both caspase-3 and p38 mitogen-activated protein kinase in autotransplanted SMG. Therefore, the cytoprotective effects of phenylephrine on autotransplanted SMG may be a novel clinical strategy for autotransplanted SMG protection during the early postoperative stage of transplantation.

  18. Bcl-2-regulated apoptosis: mechanism and therapeutic potential.

    PubMed

    Adams, Jerry M; Cory, Suzanne

    2007-10-01

    Apoptosis is essential for tissue homeostasis, particularly in the hematopoietic compartment, where its impairment can elicit neoplastic or autoimmune diseases. Whether stressed cells live or die is largely determined by interplay between opposing members of the Bcl-2 protein family. Bcl-2 and its closest homologs promote cell survival, but two other factions promote apoptosis. The BH3-only proteins sense and relay stress signals, but commitment to apoptosis requires Bax or Bak. The BH3-only proteins appear to activate Bax and Bak indirectly, by engaging and neutralizing their pro-survival relatives, which otherwise constrain Bax and Bak from permeabilizing mitochondria. The Bcl-2 family may also regulate autophagy and mitochondrial fission/fusion. Its pro-survival members are attractive therapeutic targets in cancer and perhaps autoimmunity and viral infections. PMID:17629468

  19. Cell metabolism: an essential link between cell growth and apoptosis

    PubMed Central

    Mason, Emily F.; Rathmell, Jeffrey C.

    2010-01-01

    Growth factor-stimulated or cancerous cells require sufficient nutrients to meet the metabolic demands of cell growth and division. If nutrients are insufficient, metabolic checkpoints are triggered that lead to cell cycle arrest and the activation of the intrinsic apoptotic cascade through a process dependent on the Bcl-2 family of proteins. Given the connections between metabolism and apoptosis, the notion of targeting metabolism to induce cell death in cancer cells has recently garnered much attention. However, the signaling pathways by which metabolic stresses induce apoptosis have not as of yet been fully elucidated. Thus, the best approach to this promising therapeutic avenue remains unclear. This review will discuss the intricate links between metabolism, growth, and intrinsic apoptosis and will consider ways in which manipulation of metabolism might be exploited to promote apoptotic cell death in cancer cells. PMID:20816705

  20. Hrk/DP5 contributes to the apoptosis of select neuronal populations but is dispensable for haematopoietic cell apoptosis.

    PubMed

    Coultas, Leigh; Terzano, Susanna; Thomas, Tim; Voss, Anne; Reid, Kate; Stanley, Edouard G; Scott, Clare L; Bouillet, Philippe; Bartlett, Perry; Ham, Jonathan; Adams, Jerry M; Strasser, Andreas

    2007-06-15

    The pro-apoptotic BH3-only members of the Bcl2 family, crucial initiators of cell death, are activated by a diverse array of developmental cues or experimentally applied stress stimuli. We have investigated, through gene targeting in mice, the biological roles for the BH3-only family member HRK (also known as DP5) in apoptosis regulation. Hrk gene expression was found to be restricted to cells and tissues of the central and peripheral nervous systems. Sensory neurons from mice lacking Hrk were less sensitive to apoptosis induced by nerve growth factor (NGF) withdrawal, consistent with the induction of Hrk following NGF deprivation. By contrast, cerebellar granule neurons that upregulate Hrk upon transfer to low-K+ medium underwent apoptosis normally under these conditions in the absence of Hrk. Furthermore, loss of Hrk was not sufficient to rescue the neuronal degeneration in lurcher mutant mice. Despite previous reports, no evidence was found for Hrk expression or induction in growth-factor-dependent haematopoietic cell lines following withdrawal of their requisite cytokine, and haematopoietic progenitors lacking HRK died normally in response to cytokine deprivation. These results demonstrate that HRK contributes to apoptosis signalling elicited by trophic factor withdrawal in certain neuronal populations but is dispensable for apoptosis of haematopoietic cells. PMID:17535852

  1. Augmenter of liver regeneration (ALR) protects human hepatocytes against apoptosis

    SciTech Connect

    Ilowski, Maren; Kleespies, Axel; Toni, Enrico N. de; Donabauer, Barbara; Jauch, Karl-Walter; Hengstler, Jan G.; Thasler, Wolfgang E.

    2011-01-07

    Research highlights: {yields} ALR decreases cytochrome c release from mitochondria. {yields} ALR protects hepatocytes against apoptosis induction by ethanol, TRAIL, anti-Apo, TGF-{beta} and actinomycin D. {yields} ALR exerts a liver-specific anti-apoptotic effect. {yields} A possible medical usage of ALR regarding protection of liver cells during apoptosis inducing therapies. -- Abstract: Augmenter of liver regeneration (ALR) is known to support liver regeneration and to stimulate proliferation of hepatocytes. However, it is not known if ALR exerts anti-apoptotic effects in human hepatocytes and whether this protective effect is cell type specific. This is relevant, because compounds that protect the liver against apoptosis without undesired effects, such as protection of metastatic tumour cells, would be appreciated in several clinical settings. Primary human hepatocytes (phH) and organotypic cancer cell lines were exposed to different concentrations of apoptosis inducers (ethanol, TRAIL, anti-Apo, TGF-{beta}, actinomycin D) and cultured with or without recombinant human ALR (rhALR). Apoptosis was evaluated by the release of cytochrome c from mitochondria and by FACS with propidium iodide (PI) staining. ALR significantly decreased apoptosis induced by ethanol, TRAIL, anti-Apo, TGF-{beta} and actinomycin D. Further, the anti-apoptotic effect of ALR was observed in primary human hepatocytes and in HepG2 cells but not in bronchial (BC1), colonic (SW480), gastric (GC1) and pancreatic (L3.6PL) cell lines. Therefore, the hepatotrophic growth factor ALR acts in a liver specific manner with regards to both its mitogenic and its anti-apoptotic effect. Unlike the growth factors HGF and EGF, rhALR acts in a liver specific manner. Therefore, ALR is a promising candidate for further evaluation as a possible hepatoprotective factor in clinical settings.

  2. Dividing roles of prion protein in staurosporine-mediated apoptosis.

    PubMed

    Zhang, Ying; Qin, Kefeng; Wang, Jianwei; Hung, Tao; Zhao, Richard Y

    2006-10-20

    Prion protein (PrPC) is a normal cellular glycoprotein that is expressed in almost all tissues including the central nervous system. Much attention has been focused on this protein because conversion of the normal PrPC to the diseased form (PrPSc) plays an essential role in transmissible spongiform encephalopathies such as mad cow disease and Creutzfeldt-Jakob disease. In spite of the extensive effort, the normal physiological function of PrPC remains elusive. Emerging evidence suggests that PrPC plays a protective role against cellular stresses including apoptosis induced by various pro-apoptotic agents such as Bax and staurosporine (STS), however, other reports showed overexpression of PrPC enhances STS-mediated apoptosis. In this study, we took a different approach by depleting endogenous PrPC using specific interfering RNA technique and compared the depleting and overproducing effects of PrPC on STS-induced apoptosis in neuro-2a (N2a) cells. We demonstrate here that down-regulation of PrPC sensitizes N2a cells to STS-induced cytotoxicity and apoptosis. The enhanced apoptosis induced by STS was shown by increased DNA fragmentation, immunoreactivity of Bax, and caspase-3 cleavage. We also showed that overproduction of PrPC had little or no effect on STS-mediated DNA fragmentation in N2a cells but it augments STS-mediated apoptosis in HEK293 cells, suggesting a cell line-specific effect. In addition, the inhibitory effect of PrPC on STS-mediated cellular stress appears to be modulated in part through induction of cell cycle G2 accumulation. Together, our data suggest that physiological level of endogenous PrPC plays a protective role against STS-mediated cellular stress. Loss of this protection could render cells more prone to cellular insults such as STS. PMID:16950206

  3. Proteins containing oxidized amino acids induce apoptosis in human monocytes.

    PubMed

    Dunlop, Rachael A; Brunk, Ulf T; Rodgers, Kenneth J

    2011-04-01

    Cellular deposits of oxidized and aggregated proteins are hallmarks of a variety of age-related disorders, but whether such proteins contribute to pathology is not well understood. We previously reported that oxidized proteins form lipofuscin/ceroid-like bodies with a lysosomal-type distribution and up-regulate the transcription and translation of proteolytic lysosomal enzymes in cultured J774 mouse macrophages. Given the recently identified role of lysosomes in the induction of apoptosis, we have extended our studies to explore a role for oxidized proteins in apoptosis. Oxidized proteins were biosynthetically generated in situ by substituting oxidized analogues for parent amino acids. Apoptosis was measured with Annexin-V/PI (propidium iodide), TUNEL (terminal deoxynucleotidyltransferase-mediated dUTP nick-end labelling), MMP (mitochondrial membrane permeabilization), caspase activation and cytochrome c release, and related to lysosomal membrane permeabilization. Synthesized proteins containing the tyrosine oxidation product L-DOPA (L-3,4-dihydroxyphenylalanine) were more potent inducers of apoptosis than proteins containing the phenylalanine oxidation product o-tyrosine. Apoptosis was dependent upon incorporation of oxidized residues, as indicated by complete abrogation in cultures incubated with the non-incorporation control D-DOPA (D-3,4-dihydroxyphenylalanine) or when incorporation was competed out by parent amino acids. The findings of the present study suggest that certain oxidized proteins could play an active role in the progression of age-related disorders by contributing to LMP (lysosomal membrane permeabilization)-initiated apoptosis and may have important implications for the long-term use of L-DOPA as a therapeutic agent in Parkinson's disease. PMID:21210766

  4. Thyroid hormone and anti-apoptosis in tumor cells

    PubMed Central

    Lin, Hung-Yun; Glinsky, Gennadi V.; Mousa, Shaker A.; Davis, Paul J.

    2015-01-01

    The principal secretory product of the thyroid gland, L-thyroxine (T4), is anti-apoptotic at physiological concentrations in a number of cancer cell lines. Among the mechanisms of anti-apoptosis activated by the hormone are interference with the Ser-15 phosphorylation (activation) of p53 and with TNF?/Fas-induced apoptosis. The hormone also decreases cellular abundance and activation of proteolytic caspases and of BAX and causes increased expression of X-linked inhibitor of apoptosis (XIAP). The anti-apoptotic effects of thyroid hormone largely are initiated at a cell surface thyroid hormone receptor on the extracellular domain of integrin ?v?3 that is amply expressed and activated in cancer cells. Tetraiodothyroacetic acid (tetrac) is a T4 derivative that, in a model of resveratrol-induced p53-dependent apoptosis in glioma cells, blocks the anti-apoptotic action of thyroid hormone, permitting specific serine phosphorylation of p53 and apoptosis to proceed. In a nanoparticulate formulation limiting its action to ?v?3, tetrac modulates integrin-dependent effects on gene expression in human cancer cell lines that include increased expression of a panel of pro-apoptotic genes and decreased transcription of defensive anti-apoptotic XIAP and MCL1 genes. By a variety of mechanisms, thyroid hormone (T4) is an endogenous anti-apoptotic factor that may oppose chemotherapy-induced apoptosis in ?v?3-expressing cancer cells. It is possible to decrease this anti-apoptotic activity pharmacologically by reducing circulating levels of T4 or by blocking effects of T4 that are initiated at ?v?3. PMID:26041883

  5. Cholecystokinin octapeptide antagonizes apoptosis in human retinal pigment epithelial cells

    PubMed Central

    Liu, Yuan; Zhang, Yueling; Gu, Zhaohui; Hao, Lina; Du, Juan; Yang, Qian; Li, Suping; Wang, Liying; Gong, Shilei

    2014-01-01

    Although cholecystokinin octapeptide-8 is important for neurological function, its neuroprotective properties remain unclear. We speculated that cholecystokinin octapeptide-8 can protect human retinal pigment epithelial cells against oxidative injury. In this study, retinal pigment epithelial cells were treated with peroxynitrite to induce oxidative stress. Peroxynitrite triggered apoptosis in these cells, and increased the expression of Fas-associated death domain, Bax, caspa-se-8 and Bcl-2. These changes were suppressed by treatment with cholecystokinin octapeptide-8. These results suggest that cholecystokinin octapeptide-8 can protect human retinal pigment epithelial cells against apoptosis induced by peroxynitrite. PMID:25221599

  6. The Role of Apoptosis Associated Markers in Pathogenesis of Pulmonary Tuberculosis

    ClinicalTrials.gov

    2012-08-28

    To Compare the Serum Apoptosis-associated Markers Between Patients With Active TB and Patients With LTBI; To Evaluate the Efficiency of Apoptosis-associated Markers to Differentiate Potential of Active TB From LTBI

  7. Pseudomonas syringae Effector AvrPphB Suppresses AvrB-Induced Activation of RPM1 but Not AvrRpm1-Induced Activation.

    PubMed

    Russell, Andrew R; Ashfield, Tom; Innes, Roger W

    2015-06-01

    The Pseudomonas syringae effector AvrB triggers a hypersensitive resistance response in Arabidopsis and soybean plants expressing the disease resistance (R) proteins RPM1 and Rpg1b, respectively. In Arabidopsis, AvrB induces RPM1-interacting protein kinase (RIPK) to phosphorylate a disease regulator known as RIN4, which subsequently activates RPM1-mediated defenses. Here, we show that AvrPphB can suppress activation of RPM1 by AvrB and this suppression is correlated with the cleavage of RIPK by AvrPphB. Significantly, AvrPphB does not suppress activation of RPM1 by AvrRpm1, suggesting that RIPK is not required for AvrRpm1-induced modification of RIN4. This observation indicates that AvrB and AvrRpm1 recognition is mediated by different mechanisms in Arabidopsis, despite their recognition being determined by a single R protein. Moreover, AvrB recognition but not AvrRpm1 recognition is suppressed by AvrPphB in soybean, suggesting that AvrB recognition requires a similar molecular mechanism in soybean and Arabidopsis. In support of this, we found that phosphodeficient mutations in the soybean GmRIN4a and GmRIN4b proteins are sufficient to block Rpg1b-mediated hypersensitive response in transient assays in Nicotiana glutinosa. Taken together, our results indicate that AvrB and AvrPphB target a conserved defense signaling pathway in Arabidopsis and soybean that includes RIPK and RIN4. PMID:25625821

  8. Arylquins target vimentin to trigger Par-4 secretion for tumor cell apoptosis.

    PubMed

    Burikhanov, Ravshan; Sviripa, Vitaliy M; Hebbar, Nikhil; Zhang, Wen; Layton, W John; Hamza, Adel; Zhan, Chang-Guo; Watt, David S; Liu, Chunming; Rangnekar, Vivek M

    2014-11-01

    The tumor suppressor protein prostate apoptosis response-4 (Par-4), which is secreted by normal cells, selectively induces apoptosis in cancer cells. We identified a 3-arylquinoline derivative, designated Arylquin 1, as a potent Par-4 secretagogue in cell cultures and mice. Mechanistically, Arylquin 1 binds vimentin, displaces Par-4 from vimentin for secretion and triggers the efficient paracrine apoptosis of diverse cancer cells. Thus, targeting vimentin with Par-4 secretagogues efficiently induces paracrine apoptosis of tumor cells. PMID:25218743

  9. 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...

  10. Life and death partners: apoptosis, autophagy and the cross-talk between them

    E-print Network

    Kimchi, Adi

    Review Life and death partners: apoptosis, autophagy and the cross-talk between them A Eisenberg is a complex well-controlled process. Apoptosis, the first genetically programmed death process identified, has pathway, suppressing apoptosis, and in others, it can lead to death itself, either in collaboration

  11. Cloning and characterization of an inhibitor of apoptosis protein (IAP) from Bombyx mori

    E-print Network

    Hammock, Bruce D.

    Elsevier Science B.V. All rights reserved. Keywords: Apoptosis; Insect; Inhibitor of apoptosis protein is evolutionarily conserved across animal species [2]. Apoptosis plays an important role in the development / $ ^ see front matter ß 2001 Elsevier Science B.V. All rights reserved. PII: S 0 1 6 7 - 4 8 8 9 ( 0 0 ) 0

  12. [Development of anti-cancer drugs mediated by apoptosis and autophagy].

    PubMed

    Shimizu, Shigeomi

    2015-08-01

    Apoptosis and autophagy usually function to eliminate damaged cells and damaged proteins, respectively. Dysfunction of these events induces oncogenesis and cancer development. Therefore, small compounds that activate apoptosis and autophagy are good candidates for anti-cancer chemotherapeutics to combat cancers. This review focuses on recent advances in apoptosis/autophagy and their relationship with tumorigenesis. PMID:26281682

  13. Abstract. Doxycycline (Dc) has been demonstrated to inhibit cell growth and induce apoptosis in tumor cells,

    E-print Network

    Tian, Weidong

    that apoptosis can be in- duced in HeLa cells. Western blot data demonstrated that cytochrome c (Cyt c), Smac mediate caspase-dependent apoptosis induced by doxycycline in HeLa cells J. Wua, b, T. Liua, b, J. Xiea, bAbstract. Doxycycline (Dc) has been demonstrated to inhibit cell growth and induce apoptosis

  14. Identifying mechanisms for bistability in an apoptosis network M Chaves, T Eissing & F Allgower

    E-print Network

    Chaves, Madalena

    pathways interact with the apoptosis network, in particular the well known Nuclear Fac- tor B (NFB) pathwayIdentifying mechanisms for bistability in an apoptosis network M Chaves, T Eissing & F Allg Stuttgart, Germany Abstract The apoptosis network is a fundamental module in cellular signaling. Typically

  15. Fenofibrate, a PPAR? agonist, protect proximal tubular cells from albumin-bound fatty acids induced apoptosis via the activation of NF-kB

    PubMed Central

    Zuo, Nan; Zheng, Xiaoyu; Liu, Hanzhe; Ma, Xiaoli

    2015-01-01

    Albumin-bound fatty acids is the main cause of renal damage, PPAR? is responsible in the metabolism of fatty acids. Previous study found that PPAR? played a protective role in fatty acids overload associated tubular injury. The aim of the present study is to investigate whether fenofibrate, a PPAR? ligands, could contribute to the renoprotective action in fatty acids overload proximal tubule epithelial cells. We observed in HK-2 cells that fenofibrate significantly inhibited fatty acids bound albumin (FA-BSA) induced up-regulation of MCP-1 and IL-8. Treatment with fenofibrate attenuated renal oxidative stress induced by FA-BSA as evidenced by decreased MDA level, increased SOD activity and catalase, GPx-1 expression. FA-BSA induced apoptosis of HK-2 cells were also obviously prevented by fenofibrate. Furthermore, fenofibrate significantly increased the expression of PPAR? mRNA and protein in FA-BSA treated cells. Finally, the activation of NF-kB induced by FA-BSA was markedly suppressed by fenofibrate. Taken together, our study describes a renoprotective role of fenofibrate in fatty acids associated tubular toxicity, and the transcriptional activation of PPAR? and suppression of NF-kB were at least partially involved. PMID:26617775

  16. Bacopa monnieri Extract (CDRI-08) Modulates the NMDA Receptor Subunits and nNOS-Apoptosis Axis in Cerebellum of Hepatic Encephalopathy Rats.

    PubMed

    Mondal, Papia; Trigun, Surendra Kumar

    2015-01-01

    Hepatic encephalopathy (HE), characterized by impaired cerebellar functions during chronic liver failure (CLF), involves N-methyl-D-aspartate receptor (NMDAR) overactivation in the brain cells. Bacopa monnieri (BM) extract is a known neuroprotectant. The present paper evaluates whether BM extract is able to modulate the two NMDAR subunits (NR2A and NR2B) and its downstream mediators in cerebellum of rats with chronic liver failure (CLF), induced by administration of 50?mg/kg bw thioacetamide (TAA) i.p. for 14 days, and in the TAA group rats orally treated with 200?mg/kg bw BM extract from days 8 to 14. NR2A is known to impart neuroprotection and that of NR2B induces neuronal death during NMDAR activation. Neuronal nitric oxide synthase- (nNOS-) apoptosis pathway is known to mediate NMDAR led excitotoxicity. The level of NR2A was found to be significantly reduced with a concomitant increase of NR2B in cerebellum of the CLF rats. This was consistent with significantly enhanced nNOS expression, nitric oxide level, and reduced Bcl2/Bax ratio. Moreover, treatment with BM extract reversed the NR2A/NR2B ratio and also normalized the levels of nNOS-apoptotic factors in cerebellum of those rats. The findings suggest modulation of NR2A and NR2B expression by BM extract to prevent neurochemical alterations associated with HE. PMID:26413124

  17. Bacopa monnieri Extract (CDRI-08) Modulates the NMDA Receptor Subunits and nNOS-Apoptosis Axis in Cerebellum of Hepatic Encephalopathy Rats

    PubMed Central

    Mondal, Papia; Trigun, Surendra Kumar

    2015-01-01

    Hepatic encephalopathy (HE), characterized by impaired cerebellar functions during chronic liver failure (CLF), involves N-methyl-D-aspartate receptor (NMDAR) overactivation in the brain cells. Bacopa monnieri (BM) extract is a known neuroprotectant. The present paper evaluates whether BM extract is able to modulate the two NMDAR subunits (NR2A and NR2B) and its downstream mediators in cerebellum of rats with chronic liver failure (CLF), induced by administration of 50?mg/kg bw thioacetamide (TAA) i.p. for 14 days, and in the TAA group rats orally treated with 200?mg/kg bw BM extract from days 8 to 14. NR2A is known to impart neuroprotection and that of NR2B induces neuronal death during NMDAR activation. Neuronal nitric oxide synthase- (nNOS-) apoptosis pathway is known to mediate NMDAR led excitotoxicity. The level of NR2A was found to be significantly reduced with a concomitant increase of NR2B in cerebellum of the CLF rats. This was consistent with significantly enhanced nNOS expression, nitric oxide level, and reduced Bcl2/Bax ratio. Moreover, treatment with BM extract reversed the NR2A/NR2B ratio and also normalized the levels of nNOS-apoptotic factors in cerebellum of those rats. The findings suggest modulation of NR2A and NR2B expression by BM extract to prevent neurochemical alterations associated with HE. PMID:26413124

  18. Killing Me Softly—Future Challenges in Apoptosis Research

    PubMed Central

    Westhoff, Mike-Andrew; Brühl, Oliver; Nonnenmacher, Lisa; Karpel-Massler, Georg; Debatin, Klaus-Michael

    2014-01-01

    The induction of apoptosis, a highly regulated and clearly defined mode of cell dying, is a vital tenet of modern cancer therapy. In this review we focus on three aspects of apoptosis research which we believe are the most crucial and most exciting areas currently investigated and that will need to be better understood in order to enhance the efficacy of therapeutic measures. First, we discuss which target to select for cancer therapy and argue that not the cancer cell as such, but its interaction with the microenvironment is a more promising and genetically stable site of attack. Second, the complexity of combination therapy is elucidated using the PI3-K-mediated signaling network as a specific example. Here we show that the current clinical approach to sensitize malignancies to apoptosis by maximal, prolonged inhibition of so-called survival pathways can actually be counter productive. Third, we propose that under certain conditions which will need to be clearly defined in future, chronification of a tumor might be preferable to the attempt at a cure. Finally, we discuss further problems with utilizing apoptosis induction in cancer therapy and propose a novel potential therapeutic approach that combines the previously discussed features. PMID:24595238

  19. alpha-Amanitin induced apoptosis in primary cultured dog hepatocytes.

    PubMed

    Magdalan, Jan; Ostrowska, Alina; Piotrowska, Aleksandra; Izykowska, Ilona; Nowak, Marcin; Gomu?kiewicz, Agnieszka; Podhorska-Oko?ów, Marzena; Szelag, Adam; Dziegiel, Piotr

    2010-01-01

    Amatoxin poisoning is caused by mushroom species belonging to the genera Amanita, Galerina and Lepiota with the majority of lethal mushroom exposures attributable to Amanita phalloides. High mortality rate in intoxications with these mushrooms is principally a result of the acute liver failure following significant hepatocyte damage due to hepatocellular uptake of amatoxins. A wide variety of amatoxins have been isolated; however, alpha-amanitin (alpha-AMA) appears to be the primary toxin. Studies in vitro and in vivo suggest that alpha-AMA does not only cause hepatocyte necrosis, but also may lead to apoptotic cell death. The objective of this study was to evaluate the complex hepatocyte apoptosis in alpha-AMA cytotoxicity. All experiments were performed on primary cultured canine hepatocytes. The cells were incubated for 12 h with alpha-AMA at a final concentration of 1, 5, 10 and 20 microM. Viability test (MTT assay), apoptosis evaluation (TUNEL reaction, detection of DNA laddering and electron microscopy) were performed at 6 and 12 h of exposure to alpha-AMA. There was a clear correlation between hepatocyte viability, concentration of alpha-AMA and time of exposure to this toxin. The decline in cultured dog hepatocyte viability during the exposure to alpha-AMA is most likely preceded by enhanced cellular apoptosis. Our results demonstrate that apoptosis might contribute to pathogenesis of the severe liver injury in the course of amanitin intoxication, particularly during the early phase of poisoning. PMID:20529816

  20. Comparison of Types of Cell Death: Apoptosis and Necrosis.

    ERIC Educational Resources Information Center

    Manning, Francis; Zuzel, Katherine

    2003-01-01

    Cell death is an essential factor in many biological processes including development. Discusses two types of cell death: (1) necrosis (induced by sodium azide); and (2) apoptosis (induced by sodium chromate). Illustrates key features that differ between these two types of cells death including loss of membrane integrity and internucleosomal DNA…

  1. Differential patterns of apoptosis in response to aging in Drosophila

    E-print Network

    Seroude, Laurent

    this hypothesis in a genetic model organism, this work examines the pattern of apoptosis in the adult fly during Genetics, Baylor College of Medicine, Houston, TX 77030 Edited by Jack E. Dixon, University of California-related functional declines of multicellular organisms. To pave the way for the use of Drosophila to rigorously test

  2. Salmonella typhimurium Invasion Induces Apoptosis in Infected Macrophages

    NASA Astrophysics Data System (ADS)

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

    1996-09-01

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

  3. 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.

  4. Apoptosis in Batch Cultures of Chinese Hamster Ovary Cells

    E-print Network

    Sinskey, Anthony J.

    Apoptosis in Batch Cultures of Chinese Hamster Ovary Cells J. Goswami,1 A. J. Sinskey,2 H. Steller of the main problems in the culture of Chinese Hamster Ovary (CHO) cells continues to be the inability. Keywords: cell culture; Chinese Hamster Ovary; apopto- sis; caspase; bcl-2 INTRODUCTION Chinese Hamster

  5. ClC-3 chloride channel in hippocampal neuronal apoptosis

    PubMed Central

    Xu, Lijuan; Zhang, Shuling; Fan, Hongling; Zhong, Zhichao; Li, Xi; Jin, Xiaoxiao; Chang, Quanzhong

    2013-01-01

    Over-production of nitric oxide is pathogenic for neuronal apoptosis around the ischemic area fol-lowing ischemic brain injury. In this study, an apoptotic model in rat hippocampal neurons was tablished by 0.5 mmol/L 3-morpholinosyndnomine (SIN-1), a nitric oxide donor. The models were then cultured with 0.1 mmol/L of 4,4’-diisothiocyanostilbene-2,2’-disulfonic acid (DIDS; the chloride channel blocker) for 18 hours. Neuronal survival was detected using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and apoptosis was assayed by Hoechst 33342-labeled neuronal DNA fluorescence staining. Western blot analysis and immunoche-nescence staining were applied to determine the changes of activated caspase-3 and CIC-3 channel proteins. Real-time PCR was used to detect the mRNA expression of CIC-3. The results showed that SIN-1 reduced the neuronal survival rate, induced neuronal apoptosis, and promoted ClC-3 chloride channel protein and mRNA expression in the apoptotic neurons. DIDS reversed the effect of SIN-1. Our findings indicate that the increased activities of the ClC-3 chloride channel may be involved in hippocampal neuronal apoptosis induced by nitric oxide. PMID:25206625

  6. Estrogen receptor prevents p53-dependent apoptosis in breast cancer

    E-print Network

    Liu, Xiaole Shirley

    Estrogen receptor prevents p53-dependent apoptosis in breast cancer Shannon T. Baileya,b,c,1) More than two-thirds of breast cancers express the estrogen receptor (ER) and depend on estrogen in the treatment of ER+ breast cancers of all stages. In contrast to ER- breast cancers, which frequently harbor

  7. Punicalagin promotes autophagy to protect primary human syncytiotrophoblasts from apoptosis.

    PubMed

    Wang, Ying; Chen, Baosheng; Longtine, Mark S; Nelson, D Michael

    2016-02-01

    Punicalagin is a prominent polyphenol in pomegranate juice that protects cultured syncytiotrophoblasts from stress-induced apoptosis. Here, we test the hypothesis that punicalagin has this effect by inhibiting the mTOR kinase pathway to enhance autophagic turnover and limit apoptosis in cultured primary human syncytiotrophoblasts. In syncytiotrophoblasts, starvation, rapamycin, or punicalagin all decreased the expression of phosphorylated ribosomal protein S6, a downstream target of the mTOR kinase, and of the autophagy markers, LC3-II and p62. In contrast, in the presence of bafilomycin, an inhibitor of late stages of autophagy and degradation in the autophagolysosome, syncytiotrophoblasts exposed to starvation, rapamycin, or punicalagin all showed increased levels of LC3-II and p62. The number of LC3-II punctae also increased in punicalagin-treated syncytiotrophoblasts exposed to chloroquine, another inhibitor of autophagic degradation, and punicalagin increased the number of lysosomes. The apoptosis-reducing effect of punicalagin was attenuated by inhibition of autophagy using bafilomycin or knockdown of the autophagy related gene, ATG16L1. Collectively, these data support the hypothesis that punicalagin modulates the crosstalk between autophagy and apoptosis to promote survival in cultured syncytiotrophoblasts. PMID:26659860

  8. Prohibitin promotes apoptosis of promyelocytic leukemia induced by arsenic sulfide.

    PubMed

    He, Pengcheng; Liu, Yanfeng; Qi, Jun; Zhu, Huachao; Wang, Yuan; Zhao, Jing; Cheng, Xiaoyan; Wang, Chen; Zhang, Mei

    2015-12-01

    Arsenic sulfide (As4S4), an oral form of arsenic agent, has been shown to have similar efficacy and safety to intravenous arsenic trioxide in the treatment of acute promyelocytic leukemia (APL). The aim of the present study was to identify proteins modulated by As4S4 and to determine their involvement in the apoptotic pathway. We used comparative proteomic analysis to screen and identify the proteins that were differentially expressed with As4S4 treatment. Prohibitin (PHB) was selected for its diverse role and its increased expression in the cells treated with As4S4. To examine whether PHB play a functional role, two clones of PHB-knockdown and PHB-overexpression were generated by transfection of NB4-R1 with vectors containing PHB gene sequences. In comparison with parental NB4-R1 cells, PHB overexpression showed an increase in baseline apoptosis and an enhanced response in As4S4-induced apoptosis. PML-RAR? fusion protein was found to be reduced with PHB-overexpression, and following As4S4 treatment, a greater reduction of promyelocytic leukemia-retinoic acid receptor-? (PML-RAR?) fusion protein was seen in PHB-overexpression than that in parental cells. Consistently, PHB knockdown presented with a significant reduction in As4S4-induced apoptosis and a lesser degree of PML-RAR? degradation. The results indicate the antitumor activity of PHB in promoting apoptosis of APL cells. PMID:26498315

  9. Herbal Medicine as Inducers of Apoptosis in Cancer Treatment

    PubMed Central

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

    2014-01-01

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

  10. c-Myc functionally cooperates with Bax to induce apoptosis.

    PubMed

    Juin, Philippe; Hunt, Abigail; Littlewood, Trevor; Griffiths, Beatrice; Swigart, Lamorna Brown; Korsmeyer, Stanley; Evan, Gerard

    2002-09-01

    c-Myc promotes apoptosis by destabilizing mitochondrial integrity, leading to the release of proapoptotic effectors including holocytochrome c. Candidate mediators of c-Myc in this process are the proapoptotic members of the Bcl-2 family. We show here that fibroblasts lacking Bak remain susceptible to c-Myc-induced apoptosis whereas bax-deficient fibroblasts are resistant. However, despite this requirement for Bax, c-Myc activation exerts no detectable effects on Bax expression, localization, or conformation. Moreover, susceptibility to c-Myc-induced apoptosis can be restored in bax-deficient cells by ectopic expression of Bax or by microinjection of a peptide comprising a minimal BH3 domain. Microinjection of BH3 peptide also restores sensitivity to c-Myc-induced apoptosis in p53-deficient primary fibroblasts that are otherwise resistant. By contrast, there is no synergy between BH3 peptide and c-Myc in fibroblasts deficient in both Bax and Bak. We conclude that c-Myc triggers a proapoptotic mitochondrial destabilizing activity that cooperates with proapoptotic members of the Bcl-2 family. PMID:12167710

  11. Senescence and apoptosis: dueling or complementary cell fates?

    PubMed Central

    Childs, Bennett G; Baker, Darren J; Kirkland, James L; Campisi, Judith; van Deursen, Jan M

    2014-01-01

    In response to a variety of stresses, mammalian cells undergo a persistent proliferative arrest known as cellular senescence. Many senescence-inducing stressors are potentially oncogenic, strengthening the notion that senescence evolved alongside apoptosis to suppress tumorigenesis. In contrast to apoptosis, senescent cells are stably viable and have the potential to influence neighboring cells through secreted soluble factors, which are collectively known as the senescence-associated secretory phenotype (SASP). However, the SASP has been associated with structural and functional tissue and organ deterioration and may even have tumor-promoting effects, raising the interesting evolutionary question of why apoptosis failed to outcompete senescence as a superior cell fate option. Here, we discuss the advantages that the senescence program may have over apoptosis as a tumor protective mechanism, as well as non-neoplastic functions that may have contributed to its evolution. We also review emerging evidence for the idea that senescent cells are present transiently early in life and are largely beneficial for development, regeneration and homeostasis, and only in advanced age do senescent cells accumulate to an organism’s detriment. PMID:25312810

  12. New reagents for phosphatidylserine recognition and detection of apoptosis

    E-print Network

    Smith, Bradley D.

    bilayer surrounding animal cells is made up of four principle phospholipid components, phosphatidyl for detecting apoptosis. Ó 2005 Elsevier Ltd. All rights reserved. Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5040 1. Introduction The phospholipid bilayer surrounding animal cells is a dynamic environment made up

  13. Iron starvation induces apoptosis in Rhizopus oryzae in vitro.

    PubMed

    Shirazi, Fazal; Kontoyiannis, Dimitrios P; Ibrahim, Ashraf S

    2015-01-01

    Mortality associated with mucormycosis remains high despite current antifungals. Iron-starvation strategies have been shown to have promising activity against Mucorales. We hypothesized that iron starvation enhances apoptosis in Rhizopus oryzae. Apoptosis was characterized in R. oryzae transformed with RNAi plasmid targeting FTR1 expression (iron permease mutant) or empty plasmid grown in iron rich (0.125% FeCl3) and iron depleted media (YNB+1mM ferrozine and 1 mM ascorbic acid). Increased apoptosis was observed with dihydrorhodamine-123 and rhodamine-123 staining in the iron starved mutant FTR1 when compared to empty plasmid, followed by increased extracellular ATP levels. In addition, DNA fragmentation and metacaspase activity were prominent in FTR1. In contrast, Rhizopus strains grown in iron-rich medium displayed minimal apoptosis. Our results demonstrate a metacaspase dependent apoptotic process in iron deprived condition and further support the role of iron starvation strategies as an adjunct treatment for mucormycosis, a mechanism by which iron starvation affects R. oryzae. PMID:25830548

  14. Apoptosis activation in human carious dentin. An immunohistochemical study.

    PubMed

    Loreto, C; Psaila, A; Musumeci, G; Castorina, S; Leonardi, R

    2015-01-01

    The exact mechanisms and enzymes involved in caries progression are largely unclear. Apoptosis plays a key role in dentin remodelling related to damage repair; however, it is unclear whether apoptosis in decayed teeth is activated through the extrinsic or the intrinsic pathway. This ex vivo immunohistochemical study explored the localization of TRAIL, DR5, Bcl-2 and Bax, the main proteins involved in apoptosis, in teeth with advanced caries. To evaluate TRAIL, DR5, Bcl-2 and Bax immunoexpressions twelve permanent carious premolars were embedded in paraffin and processed for immunohistochemistry. The results showed that TRAIL and DR5 were overexpressed in dentin and in pulp vessels and mononuclear cells; strong Bax immunostaining was detected in dilated dentinal tubules close to the lesion, and Bcl-2 staining was weak in some dentin areas under the cavity or altogether absent. These findings suggest that both apoptosis pathways are activated in dental caries. Further studies are required to gain insights into its biomolecular mechanisms. PMID:26428882

  15. Apoptosis Activation in Human Carious Dentin. An Immunohistochemical Study

    PubMed Central

    Loreto, C.; Psaila, A.; Musumeci, G.; Castorina, S.; Leonardi, R.

    2015-01-01

    The exact mechanisms and enzymes involved in caries progression are largely unclear. Apoptosis plays a key role in dentin remodelling related to damage repair; however, it is unclear whether apoptosis in decayed teeth is activated through the extrinsic or the intrinsic pathway. This ex vivo immunohistochemical study explored the localization of TRAIL, DR5, Bcl-2 and Bax, the main proteins involved in apoptosis, in teeth with advanced caries. To evaluate TRAIL, DR5, Bcl-2 and Bax immunoexpressions twelve permanent carious premolars were embedded in paraffin and processed for immunohistochemistry. The results showed that TRAIL and DR5 were overexpressed in dentin and in pulp vessels and mononuclear cells; strong Bax immunostaining was detected in dilated dentinal tubules close to the lesion, and Bcl-2 staining was weak in some dentin areas under the cavity or altogether absent. These findings suggest that both apoptosis pathways are activated in dental caries. Further studies are required to gain insights into its biomolecular mechanisms. PMID:26428882

  16. Nosema Tolerant Honeybees (Apis mellifera) Escape Parasitic Manipulation of Apoptosis

    PubMed Central

    Kurze, Christoph; Le Conte, Yves; Dussaubat, Claudia; Erler, Silvio; Kryger, Per; Lewkowski, Oleg; Müller, Thomas; Widder, Miriam; Moritz, Robin F. A.

    2015-01-01

    Apoptosis is not only pivotal for development, but also for pathogen defence in multicellular organisms. Although numerous intracellular pathogens are known to interfere with the host’s apoptotic machinery to overcome this defence, its importance for host-parasite coevolution has been neglected. We conducted three inoculation experiments to investigate in the apoptotic respond during infection with the intracellular gut pathogen Nosema ceranae, which is considered as potential global threat to the honeybee (Apis mellifera) and other bee pollinators, in sensitive and tolerant honeybees. To explore apoptotic processes in the gut epithelium, we visualised apoptotic cells using TUNEL assays and measured the relative expression levels of subset of candidate genes involved in the apoptotic machinery using qPCR. Our results suggest that N. ceranae reduces apoptosis in sensitive honeybees by enhancing inhibitor of apoptosis protein-(iap)-2 gene transcription. Interestingly, this seems not be the case in Nosema tolerant honeybees. We propose that these tolerant honeybees are able to escape the manipulation of apoptosis by N. ceranae, which may have evolved a mechanism to regulate an anti-apoptotic gene as key adaptation for improved host invasion. PMID:26445372

  17. The mitochondrial ARTS protein promotes apoptosis through targeting XIAP

    E-print Network

    Steller, Hermann

    . In Drosophila, the IAP antagonists Reaper, Hid and Grim are essential for the induction of virtually all dominantly suppress cell killing by Reaper, Hid and Grim, indicating that peanut acts downstream). In cells that are doomed to die, inhibition of apoptosis has to be overcome. In Drosophila, Reaper, Hid

  18. ZINC-DEPENDENT POTASSIUM CHANNEL MODULATION MEDIATES NEURONAL APOPTOSIS

    E-print Network

    Sibille, Etienne

    ZINC-DEPENDENT POTASSIUM CHANNEL MODULATION MEDIATES NEURONAL APOPTOSIS By Patrick Timothy Redman B of Biological Department of Neurobiology Sciences Major Advisor Outside Examiner #12;iii ZINC of Pittsburgh, 2008 Advisor: Elias Aizenman, Ph.D. The liberation of zinc from intracellular stores during

  19. Endogenous interleukin 18 regulates testicular germ cell apoptosis during endotoxemia.

    PubMed

    Inoue, Taketo; Aoyama-Ishikawa, Michiko; Kamoshida, Shingo; Nishino, Satoshi; Sasano, Maki; Oka, Nobuki; Yamashita, Hayato; Kai, Motoki; Nakao, Atsunori; Kotani, Joji; Usami, Makoto

    2015-08-01

    Orchitis (testicular swelling) often occurs during systemic inflammatory conditions, such as sepsis. Interleukin 18 (IL18) is a proinflammatory cytokine and is an apoptotic mediator during endotoxemia, but the role of IL18 in response to inflammation in the testes was unclear. WT and IL18 knockout (KO) mice were injected lipopolysaccharide (LPS) to induce endotoxemia and examined 12 and 48? h after LPS administration to model the acute and recovery phases of endotoxemia. Caspase activation was assessed using immunohistochemistry. Protein and mRNA expression were examined by western blot and quantitative real-time RT-PCR respectively. During the acute phase of endotoxemia, apoptosis (as indicated by caspase-3 cleavage) was increased in WT mice but not in IL18 KO mice. The death receptor-mediated and mitochondrial-mediated apoptotic pathways were both activated in the WT mice but not in the KO mice. During the recovery phase of endotoxemia, apoptosis was observed in the IL18 KO mice but not in the WT mice. Activation of the death-receptor mediated apoptotic pathway could be seen in the IL18 KO mice but not the WT mice. These results suggested that endogenous IL18 induces germ cell apoptosis via death receptor mediated- and mitochondrial-mediated pathways during the acute phase of endotoxemia and suppresses germ cell apoptosis via death-receptor mediated pathways during recovery from endotoxemia. Taken together, IL18 could be a new therapeutic target to prevent orchitis during endotoxemia. PMID:25934945

  20. Vibrio fischeri Lipopolysaccharide Induces Developmental Apoptosis, but Not Complete

    E-print Network

    McFall-Ngai, Margaret

    in the induction of animal cell apoptosis in other systems. Purified V. fischeri LPS, as well as the LPS of V interactions between and among the animal cells that share a common genome. However, postembryonic). Not surprisingly, animal­ bacterial cell interactions have been found to rely princi- pally on these same processes

  1. 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

  2. Broad targeting of resistance to apoptosis in cancer.

    PubMed

    Mohammad, Ramzi M; Muqbil, Irfana; Lowe, Leroy; Yedjou, Clement; Hsu, Hsue-Yin; Lin, Liang-Tzung; Siegelin, Markus David; Fimognari, Carmela; Kumar, Nagi B; Dou, Q Ping; Yang, Huanjie; Samadi, Abbas K; Russo, Gian Luigi; Spagnuolo, Carmela; Ray, Swapan K; Chakrabarti, Mrinmay; Morre, James D; Coley, Helen M; Honoki, Kanya; Fujii, Hiromasa; Georgakilas, Alexandros G; Amedei, Amedeo; Niccolai, Elena; Amin, Amr; Ashraf, S Salman; Helferich, William G; Yang, Xujuan; Boosani, Chandra S; Guha, Gunjan; Bhakta, Dipita; Ciriolo, Maria Rosa; Aquilano, Katia; Chen, Sophie; Mohammed, Sulma I; Keith, W Nicol; Bilsland, Alan; Halicka, Dorota; Nowsheen, Somaira; Azmi, Asfar S

    2015-12-01

    Apoptosis or programmed cell death is natural way of removing aged cells from the body. Most of the anti-cancer therapies trigger apoptosis induction and related cell death networks to eliminate malignant cells. However, in cancer, de-regulated apoptotic signaling, particularly the activation of an anti-apoptotic systems, allows cancer cells to escape this program leading to uncontrolled proliferation resulting in tumor survival, therapeutic resistance and recurrence of cancer. This resistance is a complicated phenomenon that emanates from the interactions of various molecules and signaling pathways. In this comprehensive review we discuss the various factors contributing to apoptosis resistance in cancers. The key resistance targets that are discussed include (1) Bcl-2 and Mcl-1 proteins; (2) autophagy processes; (3) necrosis and necroptosis; (4) heat shock protein signaling; (5) the proteasome pathway; (6) epigenetic mechanisms; and (7) aberrant nuclear export signaling. The shortcomings of current therapeutic modalities are highlighted and a broad spectrum strategy using approaches including (a) gossypol; (b) epigallocatechin-3-gallate; (c) UMI-77 (d) triptolide and (e) selinexor that can be used to overcome cell death resistance is presented. This review provides a roadmap for the design of successful anti-cancer strategies that overcome resistance to apoptosis for better therapeutic outcome in patients with cancer. PMID:25936818

  3. Signaling pathway for apoptosis: a racetrack for life or death.

    PubMed

    Wang, E; Marcotte, R; Petroulakis, E

    1999-01-01

    Apoptosis, or programmed cell death, is a gene-directed mechanism activated as a suicidal event to get rid of excess, damaged, or infected cells. The recent astounding pace of research in this area has expanded our horizon of understanding that this mechanism is regulated largely by pro- and anti-apoptosis factors acting for or against the final death event. The driving force behind these factors, either pro-apoptosis or pro-survival, is largely determined by signal transduction pathways, starting with the initiation of a death signal at the plasma membrane, and following through a complex cytoplasmic network before reaching the end point of cell demise. Enmeshed in this intricate cytoplasmic network are many checkpoints, where complexes of pro- and anti-apoptosis factors function to facilitate or deter the death signals. The culmination of the balancing act between these two camps of factors at these signal transduction checkpoints may then result in the final decision to die or to live. Thus, the eventual death of a cell may require successful passage through all the checkpoints, a mechanism Nature has provided as a safeguard to prevent erroneous triggering of death. With the advent of a new biotechnology revolution at the dawn of the new millenium, we look forward to an exciting era when we can gain fuller understanding of the operation of all these checkpoints. Ultimately, this gain will pave the way to control the apoptosis event at the checkpoints, and to support the organism's functionality as long as possible. J. Cell. Biochem. Suppls. 32/33:95-102, 1999. PMID:10629108

  4. ING1 induces apoptosis through direct effects at the mitochondria

    PubMed Central

    Bose, P; Thakur, S; Thalappilly, S; Ahn, B Y; Satpathy, S; Feng, X; Suzuki, K; Kim, S W; Riabowol, K

    2013-01-01

    The ING family of tumor suppressors acts as readers and writers of the histone epigenetic code, affecting DNA repair, chromatin remodeling, cellular senescence, cell cycle regulation and apoptosis. The best characterized member of the ING family, ING1, interacts with the proliferating cell nuclear antigen (PCNA) in a UV-inducible manner. ING1 also interacts with members of the 14-3-3 family leading to its cytoplasmic relocalization. Overexpression of ING1 enhances expression of the Bax gene and was reported to alter mitochondrial membrane potential in a p53-dependent manner. Here we show that ING1 translocates to the mitochondria of primary fibroblasts and established epithelial cell lines in response to apoptosis inducing stimuli, independent of the cellular p53 status. The ability of ING1 to induce apoptosis in various breast cancer cell lines correlates well with its degree of translocation to the mitochondria after UV treatment. Endogenous ING1 protein specifically interacts with the pro-apoptotic BCL2 family member BAX, and colocalizes with BAX in a UV-inducible manner. Ectopic expression of a mitochondria-targeted ING1 construct is more proficient in inducing apoptosis than the wild type ING1 protein. Bioinformatic analysis of the yeast interactome indicates that yeast ING proteins interact with 64 mitochondrial proteins. Also, sequence analysis of ING1 reveals the presence of a BH3-like domain. These data suggest a model in which stress-induced cytoplasmic relocalization of ING1 by 14-3-3 induces ING1-BAX interaction to promote mitochondrial membrane permeability and represent a paradigm shift in our understanding of ING1 function in the cytoplasm and its contribution to apoptosis.

  5. Chandipura virus perturbs cholesterol homeostasis leading to neuronal apoptosis.

    PubMed

    Ghosh, Sourish; Mukherjee, Sriparna; Basu, Anirban

    2015-10-01

    Chandipura virus (CHPV; genus Vesiculovirus, family Rhabdoviridae) induces neuronal death through the Fas-mediated extrinsic apoptosis pathway. What propels this apoptosis remains unclear, although oxysterols have been reported to be key players in neurodegeneration. In our study of CHPV-infected brain samples, we observed over-expression of genes such as apolipoprotein E, Cyp46a1, Srebf-1 and Nsdhl. This backs up the hypothesis that CHPV replication demands cholesterol that is supplied by apolipoprotein E through low density lipid receptors, lipid metabolism being pivotal for viral replication. We were able to illustrate this with over-expression of low density lipid receptors in CHPV-infected neurons. An upsurge of cholesterol concentration has been observed in neurons, triggering the expression of Cyp46a1 enzyme and culminating into the conversion of cholesterol to 24(S)-hydroxycholesterol. Increased 24(S)-hydroxycholesterol concentration is toxic to neurons, propelling neuronal apoptosis through the Fas-mediated extrinsic apoptosis pathway. For the first time, perturbation of cholesterol homeostasis in brain is shown to be utilized by the viruses for both maturation and the release of its matured virions outside the cells for continuous neuropathogenesis. Chandipura virus (CHPV) increases cholesterol import through low density lipid (LDL) receptor in neurons. Cholesterol in neurons are utilized to form the CHPV envelope. Excessive accumulation of cholesterol gets converted to 24(S)-hydroxycholesterol (24(S)-OHC) by cholesterol 24-hydroxylase enzyme (encoded by Cyp46a1 gene) that induces neuronal death through apoptosis. Therapeutics aimed against cholesterol homeostasis perturbation may be an effective anti-viral strategy. PMID:26118540

  6. Iridovirus CARD Protein Inhibits Apoptosis through Intrinsic and Extrinsic Pathways

    PubMed Central

    Chen, Chien-Wen; Wu, Ming-Shan; Huang, Yi-Jen; Lin, Pei-Wen; Shih, Chueh-Ju; Lin, Fu-Pang; Chang, Chi-Yao

    2015-01-01

    Grouper iridovirus (GIV) belongs to the genus Ranavirus of the family Iridoviridae; the genomes of such viruses contain an anti-apoptotic caspase recruitment domain (CARD) gene. The GIV-CARD gene encodes a protein of 91 amino acids with a molecular mass of 10,505 Daltons, and shows high similarity to other viral CARD genes and human ICEBERG. In this study, we used Northern blot to demonstrate that GIV-CARD transcription begins at 4 h post-infection; furthermore, we report that its transcription is completely inhibited by cycloheximide but not by aphidicolin, indicating that GIV-CARD is an early gene. GIV-CARD-EGFP and GIV-CARD-FLAG recombinant proteins were observed to translocate from the cytoplasm into the nucleus, but no obvious nuclear localization sequence was observed within GIV-CARD. RNA interference-mediated knockdown of GIV-CARD in GK cells infected with GIV inhibited expression of GIV-CARD and five other viral genes during the early stages of infection, and also reduced GIV infection ability. Immunostaining was performed to show that apoptosis was effectively inhibited in cells expressing GIV-CARD. HeLa cells irradiated with UV or treated with anti-Fas antibody will undergo apoptosis through the intrinsic and extrinsic pathways, respectively. However, over-expression of recombinant GIV-CARD protein in HeLa cells inhibited apoptosis induced by mitochondrial and death receptor signaling. Finally, we report that expression of GIV-CARD in HeLa cells significantly reduced the activities of caspase-8 and -9 following apoptosis triggered by anti-Fas antibody. Taken together, these results demonstrate that GIV-CARD inhibits apoptosis through both intrinsic and extrinsic pathways. PMID:26047333

  7. 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) ? 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 ?-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 ?-particle traversals per cell. These data indicate that a particles can activate the sphingomyelin pathway to induce apoptosis. PMID:21631289

  8. Silencing CDK4 radiosensitizes breast cancer cells by promoting apoptosis

    PubMed Central

    2013-01-01

    Background The discovery of molecular markers associated with various breast cancer subtypes has greatly improved the treatment and outcome of breast cancer patients. Unfortunately, breast cancer cells acquire resistance to various therapies. Mounting evidence suggests that resistance is rooted in the deregulation of the G1 phase regulatory machinery. Methods To address whether deregulation of the G1 phase regulatory machinery contributes to radiotherapy resistance, the MCF10A immortalized human mammary epithelial cell line, ER-PR-Her2+ and ER-PR-Her2- breast cancer cell lines were irradiated. Colony formation assays measured radioresistance, while immunocytochemistry, Western blots, and flow cytometry measured the cell cycle, DNA replication, mitosis, apoptosis, and DNA breaks. Results Molecular markers common to all cell lines were overexpressed, including cyclin A1 and cyclin D1, which impinge on CDK2 and CDK4 activities, respectively. We addressed their potential role in radioresistance by generating cell lines stably expressing small hairpin RNAs (shRNA) against CDK2 and CDK4. None of the cell lines knocked down for CDK2 displayed radiosensitization. In contrast, all cell lines knocked down for CDK4 were significantly radiosensitized, and a CDK4/CDK6 inhibitor sensitized MDA-MB-468 to radiation induced apoptosis. Our data showed that silencing CDK4 significantly increases radiation induced cell apoptosis in cell lines without significantly altering cell cycle progression, or DNA repair after irradiation. Our results indicate lower levels of phospho-Bad at ser136 upon CDK4 silencing and ionizing radiation, which has been shown to signal apoptosis. Conclusion Based on our data we conclude that knockdown of CDK4 activity sensitizes breast cancer cells to radiation by activating apoptosis pathways. PMID:23886499

  9. 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

  10. Suppression of ICE and Apoptosis in Mammary Epithelial Cells by Extracellular Matrix

    SciTech Connect

    Boudreau, Nancy; Sympson, C. J.; Werb, Zena; Bissell, Mina J.

    1994-12-01

    Apoptosis (programmed cell death) plays a major role in development and tissue regeneration. Basement membrane extracellular matrix (ECM), but not fibronectin or collagen, was shown to suppress apoptosis of mammary epithelial cells in tissue culture and in vivo. Apoptosis was induced by antibodies to beta 1 integrins or by overexpression of stromelysin-1, which degrades ECM. Expression of interleukin-1 beta converting enzyme (ICE) correlated with the loss of ECM, and inhibitors of ICE activity prevented apoptosis. These results suggest that ECM regulates apoptosis in mammary epithelial cells through an integrin-dependent negative regulation of ICE expression.

  11. Efficacy of an AC sinusoidal electric field for apoptosis induction in lung carcinoma cells (A549)

    NASA Astrophysics Data System (ADS)

    Park, Hyoun-Hyang; Lee, Seung S.; Hoon Lee, Dae

    2012-08-01

    An AC sinusoidal electric field was applied to lung carcinoma cells for the induction of apoptosis. The occurrence of apoptosis was determined by analysis of Annexin V/PI and DNA fragmentation. Additional evidence of apoptosis was confirmed by caspase-3 cleavage and disruption of mitochondrial membrane potential. These results demonstrated that the expression of apoptosis can be controlled by varying the magnitude and the duration of the field, and that the application of an AC electric field can stimulate the apoptosis via mitochondria-mediated pathway.

  12. Apoptosis-Inducing Galactolipids from a Cultured Marine Diatom, Phaeodactylum tricornutum

    PubMed Central

    Andrianasolo, Eric H.; Haramaty, Liti; Vardi, Assaf; White, Eileen; Lutz, Richard; Falkowski, Paul

    2010-01-01

    Two monogalactosyl diacylglycerols, 1 and 2, were isolated from the marine diatom Phaeodactylum tricornutum, using the patented ApopScreen cell-based screen for apoptosis-inducing, potential anticancer compounds. The molecular structures of the galactolipids were determined using a combination of NMR, mass spectrometry, and chemical degradation. The bioactivities were confirmed using a specific apoptosis induction assay based on genetically engineered mammalian cell lines with differential, defined capacities for apoptosis. The galactolipids induce apoptosis in micromolar concentrations. This is the first report of apoptosis induction by galactolipids. PMID:18570469

  13. An on-line SPE-HPLC method for effective sample preconcentration and determination of fenoxycarb and cis, trans-permethrin in surface waters.

    PubMed

    Šatínský, Dalibor; Naibrtová, Linda; Fernández-Ramos, Carolina; Solich, Petr

    2015-09-01

    A new on-line SPE-HPLC method using fused-core columns for on-line solid phase extraction and large volume sample injection for increasing the sensitivity of detection was developed for the determination of insecticides fenoxycarb and cis-, trans-permethrin in surface waters. The separation was carried out on fused-core column Phenyl-Hexyl (100×4.6 mm), particle size 2.7 µm with mobile phase acetonitrile:water in gradient mode at flow rate 1.0 mL min(-1), column temperature 45°C. Large volume sample injection (1500 µL) to the extraction dimension using short precolumn Ascentis Express RP C-18 (5×4.6 mm); fused-core particle size 2.7 µm allowed effective sample preconcentration and efficient ballast sample matrix removal. The washing mobile phase consisting of a mixture of acetonitrile:water; 30:70, (v/v) was pumped at flow rate of 0.5 mL min(-1) through the extraction precolumn to the waste. Time of the valve switch for transferring the preconcentrated sample zone from the extraction to the separation column was set at 3rd min. Elution of preconcentrated insecticides from the extraction precolumn and separation on the analytical column was performed in gradient mode. Linear gradient elution started from 40% of acetonitrile at time of valve switch from SPE column (3rd min) to 95% of acetonitrile at 7th min. Synthetic dye sudan I was chosen as an internal standard. UV detection at wavelength 225 nm was used and the method reached the limits of detection (LOD) at ng mL(-1) levels for both insecticides. The method showing on-line sample pretreatment and preconcentration with highly sensitive determination of insecticides was applied for monitoring of fenoxycarb and both permethrin isomers in different surface water samples in Czech Republic. The time of whole analysis including on-line extraction, interferences removal, chromatography separation and system equilibration was less than 8 min. PMID:26003701

  14. 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.

  15. Pivotal role of apoptosis signal-regulating kinase 1 in monoclonal free light chain-mediated apoptosis.

    PubMed

    Ying, Wei-Zhong; Wang, Pei-Xuan; Sanders, Paul W

    2012-01-01

    Renal failure, a major complication associated with multiple myeloma, is usually related to deposition of monoclonal immunoglobulin free light chains (FLCs) and directly contributes to morbidity and mortality in this disease. The present study focused on the cytotoxic effects of monoclonal FLCs. Human proximal tubular epithelial cells (HK-2) were examined after incubation with two human monoclonal FLCs (termed ?2 and ?3). Incubation of HK-2 cells for 24 and 48 hours with either FLCs at 1 mg/mL promoted activation of caspase-9 and caspase-3 and increased the rate of apoptosis. Because prior studies demonstrated that FLCs generated intracellular oxidative stress, our studies focused on the redox-sensitive mitogen-activated protein kinase kinase kinase known as apoptosis signal-regulating kinase 1 (ASK1). A time-dependent increase in phosphorylation of ASK1 at T845, indicating activation of this enzyme, was observed. Small interfering RNA designed to reduce ASK1 expression in HK-2 cells successfully decreased ASK1, which was confirmed by Western blot analysis. Incubation of ASK1-depleted HK-2 cells with the two FLCs prevented the increase in apoptosis while pretreating HK-2 cell with nontargeting small interfering RNA did not prevent FLCs-mediated apoptosis. The combined data demonstrate that monoclonal FLCs activated the intrinsic apoptotic pathway in renal epithelial cells by activation of ASK1. PMID:22079929

  16. Wavelength-dependent backscattering measurements for quantitative monitoring of apoptosis, Part 1: early and late spectral changes are indicative of the presence of apoptosis in cell cultures

    NASA Astrophysics Data System (ADS)

    Mulvey, Christine S.; Zhang, Kexiong; Liu, Wei-Han Bobby; Waxman, David J.; Bigio, Irving J.

    2011-11-01

    Apoptosis, a form of programmed cell death with unique morphological and biochemical features, is dysregulated in cancer and is activated by many cancer chemotherapeutic drugs. Noninvasive assays for apoptosis in cell cultures can aid in screening of new anticancer agents. We have previously demonstrated that elastic scattering spectroscopy can monitor apoptosis in cell cultures. In this report we present data on monitoring the detailed time-course of scattering changes in a Chinese hamster ovary (CHO) and PC-3 prostate cancer cells treated with staurosporine to induce apoptosis. Changes in the backscattering spectrum are detectable within 10 min, and continue to progress up to 48 h after staurosporine treatment, with the magnitude and kinetics of scattering changes dependent on inducer concentration. Similar responses were observed in CHO cells treated with several other apoptosis-inducing protocols. Early and late scattering changes were observed under conditions shown to induce apoptosis via caspase activity assay and were absent under conditions where apoptosis was not induced. Finally, blocking caspase activity and downstream apoptotic morphology changes prevented late scattering changes. These observations demonstrate that early and late changes in wavelength-dependent backscattering correlate with the presence of apoptosis in cell cultures and that the late changes are specific to apoptosis.

  17. MicroRNA-208a Dysregulates Apoptosis Genes Expression and Promotes Cardiomyocyte Apoptosis during Ischemia and Its Silencing Improves Cardiac Function after Myocardial Infarction

    PubMed Central

    Tony, Hasahya; Meng, Kai; Wu, Bangwei; Yu, Aijia; Zeng, Qiutang; Yu, Kunwu; Zhong, Yucheng

    2015-01-01

    Aims. miR-208a is associated with adverse outcomes in several cardiac pathologies known to have increased apoptosis, including myocardial infarction (MI). We investigated if miR-208a has proapoptotic effects on ischemic cardiomyocytes and if its silencing has therapeutic benefits in MI. Methods and Results. The effect of miR-208a on apoptosis during ischemia was studied in cultured neonatal mice myocytes transfected with agomir or antagomir. Differential gene expression was assessed using microarrays. MI was induced in male C57BL/6 mice randomly assigned to antagomir (n = 6) or control group (n = 7), while sham group (n = 7) had sham operation done. Antagomir group received miR208a antagomir, while control and sham group mice received vehicle only. At 7 and 28 days, echocardiography was done and thereafter hearts were harvested for analysis of apoptosis by TUNEL method, fibrosis using Masson's trichrome, and hypertrophy using hematoxylin and eosin. miR-208a altered apoptosis genes expression and increased apoptosis in ischemic cardiomyocytes. Therapeutic inhibition of miR-208a decreased cardiac fibrosis, hypertrophy, and apoptosis and significantly improved cardiac function 28 days after MI. Conclusion. miR-208a alters apoptosis genes expression and promotes apoptosis in ischemic cardiomyocytes, and its silencing attenuates apoptosis, fibrosis, and hypertrophy after MI, with significant improvement in cardiac function. PMID:26688617

  18. Different mechanisms of saturated versus polyunsaturated FFA-induced apoptosis in human endothelial cells.

    PubMed

    Artwohl, Michaela; Lindenmair, Andrea; Sexl, Veronika; Maier, Christina; Rainer, Georg; Freudenthaler, Angelika; Huttary, Nicole; Wolzt, Michael; Nowotny, Peter; Luger, Anton; Baumgartner-Parzer, Sabina M

    2008-12-01

    Apoptosis and underlying mechanisms were evaluated in human umbilical vein endothelial cells (HUVECs), in target tissues of late diabetic vascular complications [human aortic endothelial cells (HAECs) and human retinal endothelial cells (HRECs)], and in endothelial progenitor cells (EPCs) exposed to FFAs, which are elevated in obesity and diabetes. Saturated stearic acid concentration dependently induced apoptosis that could be mediated via reduced membrane fluidity, because both apoptosis and membrane rigidity are counteracted by eicosapentaenoic acid. PUFAs triggered apoptosis at a concentration of 300 micromol/l in HUVECs, HAECs, and EPCs, but not HRECs, and, in contrast to stearic acid, involved caspase-8 activation. PUFA-induced apoptosis, but not stearic acid-induced apoptosis, strictly correlated (P < 0.01) with protein expression of E2F-1 (r = 0.878) and c-myc (r = 0.966). Lack of c-myc expression and activity owing to quiescence or transfection with dominant negative In373-Myc, respectively, renders HUVECs resistant to PUFA-induced apoptosis. Because c-myc is abundant in growing cells only, apoptosis triggered by PUFAs, but not by saturated stearic acid, obviously depends on the growth/proliferation status of the cells. Finally, this study shows that FFA-induced apoptosis depends on the vascular origin and growth/proliferation status of endothelial cells, and that saturated stearic acid-induced apoptosis and PUFA-induced apoptosis are mediated via different mechanisms. PMID:18682607

  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. 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.

  1. Cell cycle and apoptosis regulatory protein-1: a novel regulator of apoptosis in the colonic mucosa during aging.

    PubMed

    Majumdar, Adhip P N; Du, Jianhua; Yu, Yingjie; Xu, Hu; Levi, Edi; Patel, Bhaumik B; Rishi, Arun K

    2007-12-01

    Although the regulatory mechanisms for the age-related rise in proliferation and reduction in apoptosis in the colonic mucosa are yet to be fully delineated, we have demonstrated that these events are associated with increased expression and activation of epithelial growth factor receptor (EGFR)/ErbB-1 and some of its receptor family members (EGFRs), indicating their involvement in these processes. However, the downstream signaling events of EGFR and/or its family members regulating age-related changes in mucosal proliferation and apoptosis remain to be delineated. Cell cycle and apoptosis regulatory protein-1 (CARP-1), a novel growth signaling regulator that we isolated, participates in EGFR-dependent signaling. In the current investigation, we examined the involvement of CARP-1 in colonic mucosal growth-related processes during aging. We report that the age-related reduction in apoptosis in the colonic mucosa is associated with increased expression and tyrosine phosphorylation of not only EGFR but also ErbB-2 and ErbB-3. In contrast, protein and mRNA levels of CARP-1 as well as tyrosine phosphorylation of CARP-1 are decreased. Additionally, we have observed that administration of wortmannin, an inhibitor of phosphatidylinositol 3-kinase activity that accelerates apoptosis in the colonic mucosa of aged rats, causes a marked increase in expression and tyrosine phosphorylation of CARP-1. The age-related decline in CARP-1 expression could partly be attributed to increased methylation of the CARP-1 promoter. Taken together, our data suggest that not only EGFR but also its other members are involved in regulating colonic mucosal growth during aging and that CARP-1 may play a crucial role in transducing EGFRs signals. PMID:17932228

  2. Cytotoxic Activity and Apoptosis Induction of Hypericum scabrum L.

    PubMed Central

    Hamzeloo-Moghadam, Maryam; Khalaj, Amir; Malekmohammadi, Maryam

    2015-01-01

    Background: One of the acquired biological hallmarks of tumor multistep development is the resistance of cancer cells to apoptosis; therefore, induction of apoptosis is an important therapeutic approach. Hypericum species are spread throughout the world and have been investigated for their biological properties. Objectives: Our previous studies had demonstrated cytotoxicity of Hypericum scabrum L. methanol extract against some tumor cell lines, suggesting the species for further studies. The objectives of the present study were to determine the most cytotoxic fraction of Hypericum scabrum L. and to assess the apoptosis induction ability of the most effective fraction as well as its methanol extract. The laboratory evidence has been presented to support the potency of Iranian Traditional Medicine (ITM) medicinal plants as a source of different biological activity surveys and drug discoveries. Materials and Methods: The present research is a descriptive study. The sampling strategy was based on ITM data of cancer phytotherapy. Hypericum scabrum was collected from Alborz province, Iran (2012) and the herbarium specimen was taxonomically identified. The petroleum ether, dichloromethane, and methanol fractions have been evaluated for cytotoxicity against M-CF7, A-549, HT-29, and HepG-2 cell lines through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide or MTT assay. The apoptosis induction ability has been assessed by activated caspase-3 inspection and Annexin V FITC/PI (propidium iodide) assays. Results: Di-chloromethane fraction demonstrated IC50 values of 25.72 ?g/mL and 24.73 ?g/mL against HT-29 and HepG-2 cell lines, respectively and IC50 values of petroleum ether fraction were 22.6 ?g/mL and 18.31 ?g/mL against HT-29 and HepG-2, respectively. The methanol fraction did not show cytotoxic activity. Both the methanol extract and the petroleum ether fraction of Hypericum scabrum L. revealed apoptosis induction ability. Conclusions: Considering the strong historical background about the therapeutic potential of the genus Hypericum and the considerable cytotoxic and apoptosis induction ability of Hypericum scabrum, this species is suggested for future biological studies. PMID:26568855

  3. Roles of c-FLIP in Apoptosis, Necroptosis, and Autophagy

    PubMed Central

    Safa, Ahmad R

    2014-01-01

    Cellular FLICE (FADD-like IL-1?-converting enzyme)-inhibitory protein (c-FLIP) is a major antiapoptotic protein and an important cytokine and chemotherapy resistance factor that suppresses cytokine- and chemotherapy-induced apoptosis. c-FLIP is expressed as long (c-FLIPL), short (c-FLIPS), and c-FLIPR splice variants in human cells. c-FLIP binds to FADD and/or caspase-8 or -10 and TRAIL receptor 5 (DR5). This interaction in turn prevents Death-Inducing Signaling Complex (DISC) formation and subsequent activation of the caspase cascade. c-FLIPL and c-FLIPS are also known to have multifunctional roles in various signaling pathways, as well as activating and/or upregulating several cytoprotective and pro-survival signaling proteins including Akt, ERK, and NF-?B. In addition to its role in apoptosis, c-FLIP is involved in programmed necroptosis (necrosis) and autophagy. Necroptosis is regulated by the Ripoptosome, which is a signaling intracellular cell death platform complex. The Ripoptosome contains receptor-interacting protein-1/Receptor-Interacting Protein-3 (RIP1), caspase-8, caspase-10, FADD, and c-FLIP isoforms involved in switching apoptotic and necroptotic cell death. c-FLIP regulates the Ripoptosome; in addition to its role in apoptosis, it is therefore also involved in necrosis. c-FLIPL attenuates autophagy by direct acting on the autophagy machinery by competing with Atg3 binding to LC3, thereby decreasing LC3 processing and inhibiting autophagosome formation. Upregulation of c-FLIP has been found in various tumor types, and its silencing has been shown to restore apoptosis triggered by cytokines and various chemotherapeutic agents. Hence, c-FLIP is an important target for cancer therapy. This review focuses on (1) the anti-apoptotic role of c-FLIP splice variants in preventing apoptosis and inducing cytokine and chemotherapy drug resistance, as well as its roles in necrosis and autophagy, and (2) modulation of c-FLIP expression as a means to enhance apoptosis and modulate necrosis and autophagy in cancer cells. PMID:25379355

  4. Determination of parent and substituted polycyclic aromatic hydrocarbons in high-fat salmon using a modified QuEChERS extraction, dispersive SPE and GC-MS

    PubMed Central

    Forsberg, Norman D.; Wilson, Glenn R.; Anderson, Kim A.

    2011-01-01

    A fast and easy modified QuEChERS (quick, easy, cheap, rugged and safe) extraction method has been developed and validated for determination of 33 parent and substituted polycyclic aromatic hydrocarbons (PAHs) in high-fat smoked salmon that greatly enhances analyte recovery compared to traditional QuEChERS procedures. Sample processing includes extraction of PAHs into a solution of ethyl acetate, acetone and iso-octane followed by cleanup with dispersive SPE and analysis by GC-MS in SIM mode. Method performance was assessed in spike recovery experiments (500 ng/g wet weight) in three commercially available smoked salmon with 3 – 11% fat. Recoveries of some 2, 3 and 5-ring PAHs were improved 50 – 200% over traditional methods, while average recovery across all PAHs was improved 67%. Method precision was good with replicate extractions typically yielding relative standard deviations < 10% and detection limits were in the low ng/g range. With this method, a single analyst could extract and cleanup ? 60 samples for PAH analysis in an 8 hour work day. PMID:21732651

  5. Distributions of H2O and CO2 ices on Ariel, Umbriel, Titania, and Oberon from IRTF/SpeX observations

    E-print Network

    W. M. Grundy; L. A. Young; J. R. Spencer; R. E. Johnson; E. F. Young; M. W. Buie

    2007-04-12

    We present 0.8 to 2.4 micron spectral observations of uranian satellites, obtained at IRTF/SpeX on 17 nights during 2001-2005. The spectra reveal for the first time the presence of CO2 ice on the surfaces of Umbriel and Titania, by means of 3 narrow absorption bands near 2 microns. Several additional, weaker CO2 ice absorptions have also been detected. No CO2 absorption is seen in Oberon spectra, and the strengths of the CO2 ice bands decline with planetocentric distance from Ariel through Titania. We use the CO2 absorptions to map the longitudinal distribution of CO2 ice on Ariel, Umbriel, and Titania, showing that it is most abundant on their trailing hemispheres. We also examine H2O ice absorptions in the spectra, finding deeper H2O bands on the leading hemispheres of Ariel, Umbriel, and Titania, but the opposite pattern on Oberon. Potential mechanisms to produce the observed longitudinal and planetocentric distributions of the two ices are considered.

  6. Rapid and selective quantification of L-theanine in ready-to-drink teas from Chinese market using SPE and UPLC-UV.

    PubMed

    Chen, Guoqiang; Wang, Yun; Song, Weiqi; Zhao, Bo; Dou, Yuling

    2012-11-15

    An ultra performance liquid chromatography (UPLC) method combined with solid phase extraction (SPE) sample pre-treatment was developed and validated for the rapid quantification of L-theanine in ready-to-drink (RTD) teas. UPLC analysis of twenty-seven RTD teas from the Chinese market revealed that the L-theanine levels in various types of RTD teas were significantly different. RTD green teas were found to contain highest mean L-theanine level (37.85±20.54 mg/L), followed by jasmine teas (36.60±12.08 mg/L), Tieguanying teas (18.54±3.46 mg/L) black teas (16.89±6.56), Pu-erh teas (11.31±0.90 mg/L) and oolong teas (3.85±2.27 mg/L). The ratio of total polyphenols content to L-theanine content could be used as a featured parameter for differentiating RTD teas. L-theanine in RTD teas could be a reliable quality parameter that is complementary to total polyphenols. PMID:22868106

  7. Development of multiclass methods for drug residues in eggs: silica SPE cleanup and LC-MS/MS analysis of ionophore and macrolide residues.

    PubMed

    Heller, David N; Nochetto, Cristina B

    2004-11-17

    A method was developed that is suitable for screening eggs for a variety of nonpolar residues in a single procedure. Residues are extracted by silica solid-phase extraction (SPE). Analysis is conducted via reverse-phase gradient liquid chromatography, electrospray ionization, and tandem ion trap mass spectrometry. For screening purposes (based on a single precursor-product ion transition) the method can detect ionophore (lasalocid, monensin, salinomycin, narasin) and macrolide (erythromycin, tylosin) residues in egg at approximately 1 ng/mL (ppb) and above and novobiocin residues at approximately 3 ppb and above. Conditions are described for confirmatory analysis based on multiple ions in the product ion spectrum. The extraction efficiency for ionophores was estimated at 60-85%, depending on drug. Recovery of macrolides and novobiocin was not as good (estimated at 40-55% after a hexane wash of the final extract was included), but the method consistently screened and confirmed these residues at concentrations below the target of 10 ppb. The method was applied to eggs from hens dosed with each drug individually. Lasalocid was found to have the highest probability of detection in eggs based on its high ionization efficiency and higher rate of deposition relative to the other drugs. The method is part of a larger scheme to provide surveillance methods for a wide variety of drug residues in eggs. PMID:15537285

  8. A new SPE/GC-fid method for the determination of cholesterol oxidation products. Application to subcutaneous fat from Iberian dry-cured ham.

    PubMed

    Narváez-Rivas, Mónica; Pham, Alessandra J; Schilling, M Wes; León-Camacho, Manuel

    2014-05-01

    A new method for the isolation and analysis of cholesterol oxidation products (COPs) using solid phase extraction (SPE) and silica columns was developed using gas chromatography-flame ion detection (GC-FID). The method comprises of saponification and liquid-liquid extraction of the unsaponifiable fraction prior to the isolation and derivatization of the COPs to trimethylsilyl ethers. The COPs used in this study are cholestane-5?-6?-epoxide, cholestane-3?-5?-6?-triol, 25-hydroxycholesterol and 5-cholesten-3?-ol-7-one. In order to identify the COPs fraction a GC-ion-trap-mass spectrometry experiment were conducted using authentic standards to verify the presence of the COPs. The method was effective at rapidly separating the COPs (25 min run). Calibration curves were linear with the LODs and LOQs bellow 0.03 and 0.07 mgkg(-1) for all cases, respectively. This methodology gave a total recovery for every compound that was used in the study. Betulin was used as an internal standard to monitor the recovery. The method was validated with a standard mixture of COPs. The method has been applied to characterize the COP fraction of subcutaneous fat from Iberian dry-cured ham. Cholestane-5?-6?-epoxide, cholestane-3?-5?-6?-triol, 25-hydroxycholesterol and 5-cholesten-3?-ol-7-one have been identified for the first time in these samples. PMID:24720962

  9. Determination of perfluorinated sulfonate and perfluorinated acids in tissues of free-living European beaver (castor fiber L.) by d-SPE/ micro-UHPLC-MS/MS.

    PubMed

    Surma, Magdalena; Gi?ejewski, Zygmunt; Zieli?ski, Henryk

    2015-10-01

    Perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA) are the main representatives of an rising class of persistent organic pollutants (POPs), perfluorochemicals (PFCs). In this study, determination of selected PFCs concentration in liver, brain, tail, adipose and peritoneum tissues of free-living European beaver (Castor fiber L.) was addressed. Tissue samples, collected from beavers living in Masurian Lakeland (NE Poland), were analyzed by dispersive Solid Phase Extraction (d-SPE) with micro-UHPLC-MS/MS system. In a group of ten selected pefrluorinated compounds only two perfluorinated acids (PFOA and PFNA) and one perfluorinated sulfonate (PFOS) were quantified. PFOA was detected in all analysed tissue samples in both female and male beavers in a range from 0.55 to 0.98ngg(-1) ww whereas PFOS was identified in all analyzed female beaver tissues and only in liver, subcutaneous adipose and peritoneum tissues of male beavers at the concentration level from 0.86 to 5.08ngg(-1) ww. PFNA was only identified in female beaver tissues (liver, subcutaneous adipose and peritoneum) in a range from 1.50 to 6.61ngg(-1) ww. This study demonstrated the bioaccumulation of PFCs in tissue samples collected from beavers living in area known as green lungs of Poland. The results provided in this study indicate for the increasing risk of PFCs occurrence in the environment and the level of PFCs in tissue of free-living European beavers may serve as bioindicator of environmental pollution by these compounds. PMID:26143169

  10. Analysis of anti-inflammatory, analgesic, stimulant and antidepressant drugs in purified water from wastewater treatment plants using SPE-LC tandem mass spectrometry.

    PubMed

    Afonso-Olivares, Cristina; Sosa-Ferrera, Zoraida; Santana-Rodríguez, José J

    2012-01-01

    This work presents an effective sample preparation method for the evaluation of seven pharmaceutical compounds belonging to different therapeutic classes in purified water from wastewater treatment plants (WWTPs). The target compounds include caffeine (stimulant), nicotine (stimulant), atenolol (beta blocker), metamizole (anti-inflammatory and analgesic), fluoxetine (antidepressant), paraxanthine (stimulant) and clofibric acid (lipid regulator). Solid-phase extraction (SPE) and liquid chromatography-mass spectrometry (LC-MS) were selected as extraction and detection techniques, respectively. A detailed study of the experimental conditions of extraction was performed. Under optimal conditions, recoveries obtained were in the range of 21% to 100%, and the relative standard deviations were below 12%. The detection and quantification limits of the method were in the range 2.2-97.4 and 21.1-324.7 ng L(-1), respectively. The developed method was successfully applied to evaluate the presence of these pharmaceutical compounds in wastewaters samples from wastewater treatment plants located on the Gran Canaria Island (Spain). Most of the compounds were detected at concentrations up to 12.31 ?g L(-1) in the WWTP influents that were studied. PMID:22423996

  11. Preconcentration of organochlorine pesticides in aqueous samples by dispersive liquid-liquid microextraction based on solidification of floating organic drop after SPE with multiwalled carbon nanotubes.

    PubMed

    Mirzaei, Mohammad; Rakh, Mojgan

    2014-01-01

    SPE joined with dispersive liquid-liquid microextraction based on solidification of floating organic drop (DLLME-SFO) as a novel technique combined with GC with electron-capture detection has been developed as a preconcentration technique for the determination of organochlorine pesticides (OCPs) in water samples. Aqueous samples were loaded onto multiwalled carbon nanotubes as sorbent. After the elution of the desired compounds from the sorbent by using acetone, the DLLME-SFO technique was performed on the obtained solution. Variables affecting the performance of both steps such as sample solution flow rate, breakthrough volume, type and volume of the elution, type and volume of extraction solvent and salt addition were studied and optimized. The new method provided an ultra enrichment factor (8280-28221) for nine OCPs. The calibration curves were linear in the range of 0.5-1000 ng/L, and the LODs ranged from 0.1-0.39 ng/L. The RSD, for 0.01 ?g/L of OCPs, was in the range of 1.39-13.50% (n = 7). The recoveries of method in water samples were 70-113%. PMID:24288158

  12. High-resolution bioactivity profiling combined with HPLC-HRMS-SPE-NMR: ?-Glucosidase inhibitors and acetylated ellagic acid rhamnosides from Myrcia palustris DC. (Myrtaceae).

    PubMed

    Wubshet, Sileshi G; Moresco, Henrique H; Tahtah, Yousof; Brighente, Inês M C; Staerk, Dan

    2015-08-01

    Type 2 diabetes (T2D) is an endocrine metabolic disease with a worldwide prevalence of more than 8%, and an expected increase close to 50% in the next 15-20years. T2D is associated with severe and life-threatening complications like retinopathy, neuropathy, nephropathy, and cardiovascular diseases, and therefore improved drug leads or functional foods containing ?-glucosidase inhibitors are needed for management of blood glucose. In this study, leaves of Myrcia palustris were investigated by high-resolution ?-glucosidase inhibition profiling combined with HPLC-HRMS-SPE-NMR. This led to identification of casuarinin, myricetin 3-O-?-d-(6?-galloyl)galactopyranoside, kaempferol 3-O-?-d-galactopyranoside, myricetin, and quercetin as ?-glucosidase inhibitors. In addition, four acetylated ellagic acid rhamnosides, i.e., 4-O-(2?,4?-O-diacetyl-?-l-rhamnopyranosyl)ellagic acid, 4-O-(2?,3?-O-diacetyl-?-l-rhamnopyranosyl)ellagic acid, 4-O-(3?,4?-O-diacetyl-?-l-rhamnopyranosyl)ellagic acid, and 4-O-(2?,3?,4?-O-triacetyl-?-l-rhamnopyranosyl)ellagic acid were identified. PMID:25935545

  13. SpeX spectroscopy of unresolved very low mass binaries. II. Identification of 14 candidate binaries with late-M/early-L and T dwarf components

    SciTech Connect

    Bardalez Gagliuffi, Daniella C.; Burgasser, Adam J.; Nicholls, Christine P.; Gelino, Christopher R.; Looper, Dagny L.; Schmidt, Sarah J.; Cruz, Kelle; West, Andrew A.; Gizis, John E.; Metchev, Stanimir

    2014-10-20

    Multiplicity is a key statistic for understanding the formation of very low mass (VLM) stars and brown dwarfs. Currently, the separation distribution of VLM binaries remains poorly constrained at small separations (?1 AU), leading to uncertainty in the overall binary fraction. We approach this problem by searching for late-M/early-L plus T dwarf spectral binaries whose combined light spectra exhibit distinct peculiarities, allowing for separation-independent identification. We define a set of spectral indices designed to identify these systems, and we use a spectral template fitting method to confirm and characterize spectral binary candidates from a library of 815 spectra from the SpeX Prism Spectral Libraries. We present 11 new binary candidates, confirm 3 previously reported candidates, and rule out 2 previously identified candidates, all with primary and secondary spectral types in the range M7-L7 and T1-T8, respectively. We find that subdwarfs and blue L dwarfs are the primary contaminants in our sample and propose a method for segregating these sources. If confirmed by follow-up observations, these systems may add to the growing list of tight separation binaries, whose orbital properties may yield further insight into brown dwarf formation scenarios.

  14. SpeX SPECTROSCOPY OF UNRESOLVED VERY LOW MASS BINARIES. I. IDENTIFICATION OF 17 CANDIDATE BINARIES STRADDLING THE L DWARF/T DWARF TRANSITION

    SciTech Connect

    Burgasser, Adam J.; Cruz, Kelle L.; Cushing, Michael; Looper, Dagny L.; Gelino, Christopher R.; Kirkpatrick, J. Davy; Faherty, Jacqueline K.; Reid, I. Neill

    2010-02-20

    We report the identification of 17 candidate brown dwarf binaries whose components straddle the L dwarf/T dwarf transition. These sources were culled from a large near-infrared spectral sample of L and T dwarfs observed with the Infrared Telescope Facility SpeX spectrograph. Candidates were selected on the basis of spectral ratios which segregate known (resolved) L dwarf/T dwarf pairs from presumably single sources. Composite templates, constructed by combining 13,581 pairs of absolute flux-calibrated spectra, are shown to provide statistically superior fits to the spectra of our 17 candidates as compared to single templates. Ten of these candidates appear to have secondary components that are significantly brighter than their primaries over the 1.0-1.3 {mu}m band, indicative of rapid condensate depletion at the L dwarf/T dwarf transition. Our results support prior indications of enhanced multiplicity amongst early-type T dwarfs; 53% +- 7% of the T0-T4 dwarfs in our spectral sample are found to be either resolved or unresolved (candidate) pairs, although this is consistent with an intrinsic (volume complete) brown dwarf binary fraction of only 15%. If verified, this sample of spectral binaries more than doubles the number of known L dwarf/T dwarf transition pairs, enabling a broader exploration of this poorly understood phase of brown dwarf atmospheric evolution.

  15. High-resolution hyaluronidase inhibition profiling combined with HPLC-HRMS-SPE-NMR for identification of anti-necrosis constituents in Chinese plants used to treat snakebite.

    PubMed

    Liu, Yueqiu; Staerk, Dan; Nielsen, Mia N; Nyberg, Nils; Jäger, Anna K

    2015-11-01

    Inhibition of the necrotizing hyaluronidase, phospholipase A2 and protease enzymes in four snake venoms by crude water and ethanol extracts of 88 plant species used against snakebites in traditional Chinese medicine was measured. High-resolution hyaluronidase inhibition profiles were constructed for the 22 plants showing highest hyaluronidase inhibition, and the results were used to guide subsequent structural analysis towards specific hyaluronidase inhibitors. Structural analysis was performed by high-performance liquid chromatography, high-resolution mass spectrometry, solid-phase extraction and nuclear magnetic resonance spectroscopy, i.e., HPLC-HRMS-SPE-NMR. This allowed identification of four non-tannin inhibitors, i.e., lansiumamide B (6) from Clausena excavata Burm.f., myricetin 3-O-?-d-glucopyranoside (7) from Androsace umbellata (Lour.) Merr., and vitexin (8) and 4',7-dihydroxy-5-methoxyflavone-8-C-?-d-glucopyranoside (9) from Oxalis corniculata L. Absolute configuration of 2,3-dihydroxy-N-methyl-3-phenyl-N-[(Z)-styryl]propanamide (1) was determined using the Mosher method, which revealed two enantiomers, i.e., (2S,3R)-2,3-dihydroxy-N-methyl-3-phenyl-N-[(Z)-styryl]propanamide and (2R,3S)-2,3-dihydroxy-N-methyl-3-phenyl-N-[(Z)-styryl]propanamide with a ratio of 7:3. PMID:26386983

  16. Resveratrol enhances ultraviolet B-induced cell death through nuclear factor-{kappa}B pathway in human epidermoid carcinoma A431 cells

    SciTech Connect

    Roy, Preeti; Kalra, Neetu; Nigam, Nidhi; George, Jasmine; Ray, Ratan Singh; Hans, Rajendra K.; Prasad, Sahdeo; Shukla, Yogeshwer

    2009-06-26

    Resveratrol has been reported to suppress cancer progression in several in vivo and in vitro models, whereas ultraviolet B (UVB), a major risk for skin cancer, is known to induce cell death in cancerous cells. Here, we investigated whether resveratrol can sensitize A431 human epidermoid carcinoma cells to UVB-induced cell death. We examined the combined effect of UVB (30 mJ/cm{sup 2}) and resveratrol (60 {mu}M) on A431 cells. Exposure of A431 carcinoma cells to UVB radiation or resveratrol can inhibit cell proliferation and induce apoptosis. However, the combination of resveratrol and UVB exposure was associated with increased proliferation inhibition of A431 cells compared with either agent alone. Furthermore, results showed that resveratrol and UVB treatment of A431 cells disrupted the nuclear factor-kappaB (NF-{kappa}B) pathway by blocking phosphorylation of serine 536 and inactivating NF-{kappa}B and subsequent degradation of I{kappa}B{alpha}, which regulates the expression of survivin. Resveratrol and UVB treatment also decreased the phosphorylation of tyrosine 701 of the important transcription factor signal transducer activator of transcription (STAT1), which in turn inhibited translocation of phospho-STAT1 to the nucleus. Moreover, resveratrol/UVB also inhibited the metastatic protein LIMK1, which reduced the motility of A431 cells. In conclusion, our study demonstrates that the combination of resveratrol and UVB act synergistically against skin cancer cells. Thus, resveratrol is a potential chemotherapeutic agent against skin carcinogenesis.

  17. Efficacy of PLGA-loaded apigenin nanoparticles in Benzo[a]pyrene and ultraviolet-B induced skin cancer of mice: mitochondria mediated apoptotic signalling cascades.

    PubMed

    Das, Sreemanti; Das, Jayeeta; Samadder, Asmita; Paul, Avijit; Khuda-Bukhsh, Anisur Rahman

    2013-12-01

    Skin cancer is increasing at an alarming rate and becoming resistant to conventional chemotherapy necessitating improved drug delivery system. We loaded apigenin (Ap), a dietary flavonoid having anti-cancer property, with poly (lactic-co-glycolide) (PLGA) nanoparticles (NAp) to explore if nano-encapsulation could enhance anti-carcinogenic effect against ultra-violet B (UVB) and Benzo(a)pyrene (BaP) induced skin tumor and mitochondrial dysfunction in mice. Particle size, morphology and zeta potential of NAp were determined using dynamic light scattering and atomic force microscopy. Tumor incidence and multiplicity in UVB-BaP induced mice with/without NAp treatment were ascertained and their histolopathological sections and chromosomal aberrations were studied. ROS accumulation and mitochondrial functioning through relevant markers like mitochondrial transmembrane potential were analyzed. Mitochondrial volume changes/swelling, cytochrome c (cyt c) release, mRNA and protein expressions of Apaf-1, bax, bcl-2, cyt c, cleaved caspase-9 and 3 were studied. Results showed that NAp produced better effects than Ap, due to their smaller size, and faster mobility. NAp reduced tissue damage and frequency of chromosomal aberrations, increased ROS accumulation to mediate mitochondrial-apoptosis through modulation of several apoptotic markers and mitochondrial matrix swelling. NAp showed ameliorative potentials in combating skin cancer and therefore has greater prospect of use in therapeutic management of skin cancer. PMID:24120900

  18. Coupling HPLC-SPE-NMR with a microplate-based high-resolution antioxidant assay for efficient analysis of antioxidants in food--validation and proof-of-concept study with caper buds.

    PubMed

    Wiese, Stefanie; Wubshet, Sileshi G; Nielsen, John; Staerk, Dan

    2013-12-15

    This work describes the coupling of a microplate-based antioxidant assay with a hyphenated system consisting of high-performance liquid chromatography-solid-phase extraction-nuclear magnetic resonance spectroscopy, i.e., HPLC-SPE-NMR/high-resolution antioxidant assay, for the analysis of complex food extracts. The applicability of the microplate-based antioxidant assay for high-resolution screening of common food phenolics as well as parameters related to their trapping efficiency, elution behavior, and recovery on/from SPE cartridges are described. It was found that the microplate-based high-resolution antioxidant assay is an attractive and easy implementable alternative to direct on-line screening methods. Furthermore, it was shown that Resin SH and Resin GP SPE material are superior to RP C18HD for trapping of phenolic compounds. Proof-of-concept study was performed with caper bud extract, revealing the most important antioxidants to be quercetin, kaempferol, rutin, kaempferol-3-O-?-rutinoside and N(1),N(5),N(10)-triphenylpropenoyl spermidine amides. Targeted isolation of the latter, and comprehensive NMR experiments showed them to be N(1),N(10)-di-(E)-caffeoyl-N(5)-p-(E)-coumaroyl spermidine, N(1)-(E)-caffeoyl-N(5),N(10)-di-p-(E)-coumaroyl spermidine, N(10)-(E)-caffeoyl-N(1),N(5)-di-p-(E)-coumaroyl spermidine, and N(1),N(5),N(10)-tri-p-(E)-coumaroyl spermidine amides. PMID:23993578

  19. Apoptosis Process in Mouse Leydig Cells during Postnatal Development

    NASA Astrophysics Data System (ADS)

    Salles Faria, Maria José; Simões, Zilá Paulino; Luz; Orive Lunardi, Laurelucia; Hartfelder, Klaus

    2003-02-01

    The development of Leydig cells in mammals has been widely described as a biphasic pattern with two temporally mature Leydig cell populations, fetal stage followed by the adult generation beginning at puberty. In the present study, mouse Leydig cells were examined for apoptosis during postnatal testis development using electron microscopy and in situ DNA fragmentation by terminal deoxynucleotidyl transferase staining (TdT). Both the morphological study and the DNA fragmentation analysis showed that cellular death by apoptosis did not occur in Leydig cells during the neonatal, prepubertal, puberty, and adult periods. From these results, we suggest that the remaining fetal Leydig cells in the neonatal testis are associated with the involution or degeneration processes. In contrast, in the prepubertal and puberty stages, fragmentation of apoptotic DNA was detected in germ cells present in some seminiferous tubules.

  20. Facile and quantitative electrochemical detection of yeast cell apoptosis

    NASA Astrophysics Data System (ADS)

    Yue, Qiulin; Xiong, Shiquan; Cai, Dongqing; Wu, Zhengyan; Zhang, Xin

    2014-03-01

    An electrochemical method based on square wave anodic stripping voltammetry (SWASV) was developed to detect the apoptosis of yeast cells conveniently and quantitatively through the high affinity between Cu2+ and phosphatidylserine (PS) translocated from the inner to the outer plasma membrane of the apoptotic cells. The combination of negatively charged PS and Cu2+ could decrease the electrochemical response of Cu2+ on the electrode. The results showed that the apoptotic rates of cells could be detected quantitatively through the variations of peak currents of Cu2+ by SWASV, and agreed well with those obtained through traditional flow cytometry detection. This work thus may provide a novel, simple, immediate and accurate detection method for cell apoptosis.

  1. The Haemopoietic Stem Cell: Between Apoptosis and Self Renewal

    PubMed Central

    Alenzi, Faris Q.; Alenazi, Badi Q.; Ahmad, Shamweel Y.; Salem, Mohamed L.; Al-Jabri, Ali A.; Wyse, Richard K.H.

    2009-01-01

    Self renewal and apoptosis of haemopoietic stem cells (HSC) represent major factors that determine the size of the haemopoietic cell mass. Changes in self renewal above or below the steady state value of 0.5 will result in either bone marrow expansion or aplasia, respectively. Despite the growing body of research that describes the potential role of HSC, there is still very little information on the mechanisms that govern HSC self renewal and apoptosis. Considerable insight into the role of HSC in many diseases has been gained in recent years. In light of their crucial importance, this article reviews recent developments in the understanding of the molecular, biological, and physiological characteristics of haemopoietic stem cells. PMID:19325941

  2. Nanoparticles of barium induce apoptosis in human phagocytes

    PubMed Central

    Mores, Luana; França, Eduardo Luzia; Silva, Núbia Andrade; Suchara, Eliane Aparecida; Honorio-França, Adenilda Cristina

    2015-01-01

    Purpose Nutrients and immunological factors of breast milk are essential for newborn growth and the development of their immune system, but this secretion can contain organic and inorganic toxins such as barium. Colostrum contamination with barium is an important issue to investigate because this naturally occurring element is also associated with human activity and industrial pollution. The study evaluated the administration of barium nanoparticles to colostrum, assessing the viability and functional activity of colostral mononuclear phagocytes. Methods Colostrum was collected from 24 clinically healthy women (aged 18–35 years). Cell viability, superoxide release, intracellular Ca2+ release, and phagocyte apoptosis were analyzed in the samples. Results Treatment with barium lowered mononuclear phagocyte viability, increased superoxide release, and reduced intracellular calcium release. In addition, barium increased cell death by apoptosis. Conclusion These data suggest that nanoparticles of barium in colostrum are toxic to cells, showing the importance of avoiding exposure to this element. PMID:26451108

  3. Apoptosis like cell death in Raillietina echinobothrida induced by resveratrol.

    PubMed

    Giri, Bikash Ranjan; Roy, Bishnupada

    2015-08-01

    Northeast India is geographically nestled as one of the biodiversity hotspots, rich in traditionally used medicinal plants. Resveratrol, a naturally occurring phytoalexin found in berries, peanuts, grapes, red wine and also in numerous anthelmintic plants, has attracted wide interest because of its diverse pharmacological characteristics. Recently, anthelmintic potential of the compound is established. The present study was carried out to understand the possible mechanism of action of resveratrol on poultry tapeworm Raillietina echinobothrida. Resveratrol showed excellent cestocidal activity in a dose dependent manner as revealed through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assay. The progressive ultrastructural alterations followed by complete disruption of nuclear membrane, chromosomal condensation and in situ DNA fragmentation confirm the occurrence of apoptosis like cell death. Increased pro-apoptotic caspase activity and significant decreases in mitochondrial membrane potential in R. echinobothrida exposed to resveratrol confirm the involvement of mitochondria in the process of apoptosis. PMID:26267101

  4. 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.

  5. Cerulenin-mediated apoptosis is involved in adenine metabolic pathway

    SciTech Connect

    Chung, Kyung-Sook; Sun, Nam-Kyu; Lee, Seung-Hee; Lee, Hyun-Jee; Choi, Shin-Jung; Kim, Sun-Kyung; Song, Ju-Hyun; Jang, Young-Joo; Song, Kyung-Bin; Yoo, Hyang-Sook; Simon, Julian . E-mail: jsimon@fhcrc.org; Won, Misun . E-mail: misun@kribb.re.kr

    2006-10-27

    Cerulenin, a fatty acid synthase (FAS) inhibitor, induces apoptosis of variety of tumor cells. To elucidate mode of action by cerulenin, we employed the proteomics approach using Schizosaccharomyces pombe. The differential protein expression profile of S. pombe revealed that cerulenin modulated the expressions of proteins involved in stresses and metabolism, including both ade10 and adk1 proteins. The nutrient supplementation assay demonstrated that cerulenin affected enzymatic steps transferring a phosphoribosyl group. This result suggests that cerulenin accumulates AMP and p-ribosyl-s-amino-imidazole carboxamide (AICAR) and reduces other necessary nucleotides, which induces feedback inhibition of enzymes and the transcriptional regulation of related genes in de novo and salvage adenine metabolic pathway. Furthermore, the deregulation of adenine nucleotide synthesis may interfere ribonucleotide reductase and cause defects in cell cycle progression and chromosome segregation. In conclusion, cerulenin induces apoptosis through deregulation of adenine nucleotide biosynthesis resulting in nuclear division defects in S. pombe.

  6. Analysis of CDK Inhibitor Action on Mitochondria-Mediated Apoptosis.

    PubMed

    Gortat, Anna

    2016-01-01

    The role of cyclin-dependent kinase inhibitors (CDKIs) is to negatively regulate cyclin-dependent kinases as a mechanism of control of cell proliferation. As such, CDKIs are being used to induce apoptosis in cancer cells to prevent their excessive reproduction. This chapter describes procedures to study apoptosis induction upon treatment with any CDKI through the evaluation of morphological and functional mitochondrial alterations, in particular, how to measure the mitochondrial membrane potential (??m) using TMRE dye, determine the content of intracellular ATP, observe mitochondrial network morphology using HeLa cells stably expressing fluorescent reporter DsRed targeting mitochondrial matrix, observe ultrastructure of the organelle using transmission electron microscopy, and, finally, assure that mitochondrial outer membrane permeabilization takes place by assessing the subcellular localization of cyt C in HeLa cells stably expressing fluorescent cyt C-GFP. PMID:26231711

  7. Paraptosis triggers mitochondrial pathway-mediated apoptosis in Alzheimer's disease

    PubMed Central

    JIA, DONG-PEI; WANG, SONG; ZHANG, BAO-CHAO; FANG, FANG

    2015-01-01

    In previous years, increasing evidence has indicated that paraptosis and mitochondrial-mediated apoptosis may be associated with Alzheimer's disease (AD). However, the association between paraptosis and mitochondrial-mediated apoptosis, and the pathological processes underlying AD, remain elusive. In the present study, the ?-amyloid precursor protein gene, and the gene mutations PS1M146L and L286V, were transfected to an SH-SY5Y cell line to establish an AD cell model. Subsequently, an MTT assay was used to examine the cell viability of the AD cell model, while a TUNEL assay was employed to observe the number of positively stained apoptotic cells. Cytoplasmic vacuolization was examined using light microscopy and images were photographed. Furthermore, western blot analysis was utilized to detect the expression of golden biomarkers of the mitochondrial pathway, including Bcl-2 and Bax. The paraptosis inhibitor, cycloheximide, was selected to treat the AD model cells in order to observe the association between paraptosis and mitochondrial-mediated apoptosis. The results indicated that the decrease in the cell viability of the AD cells was initiated at 24 h, as compared with the normal cells (P<0.05). TUNEL-positive stained cells were observed at 48 h, which was later compared with the cell death initiation. In addition, examination of cytoplasmic vacuolization using microscopy indicated that there were a small number of paraptosis cells present at 24 h. The expression levels of Bcl-2 was significantly decreased, while Bax was significantly increased at 48 h. Furthermore, cycloheximide treatment was demonstrated to significantly increase Bcl-2 expression, while decreasing Bax expression (P>0.05). In conclusion, the occurrence of paraptosis was demonstrated in the early pathological stages of AD, which may subsequently damage the mitochondria and trigger mitochondrial pathway-mediated apoptosis. Thus, paraptosis may trigger programmed cell death directly, or indirectly through the regulation of Bcl-2 and Bax protein expression. PMID:26622397

  8. MicroRNAs in apoptosis, autophagy and necroptosis

    PubMed Central

    2015-01-01

    MicroRNAs (miRNAs) are endogenous 22 nt non-coding RNAs that target mRNAs for cleavage or translational repression. Numerous miRNAs regulate programmed cell death including apoptosis, autophagy and necroptosis. We summarize how miRNAs regulate apoptotic, autophagic and necroptotic pathways and cancer progression. We also discuss how miRNAs link different types of cell death. PMID:25893379

  9. Ursolic acid mediates photosensitization by initiating mitochondrial-dependent apoptosis

    NASA Astrophysics Data System (ADS)

    Lee, Yuan-Hao; Wang, Exing; Kumar, Neeru; Glickman, Randolph D.

    2013-02-01

    The signaling pathways PI3K/Akt and MAPK play key roles in transcription, translation and carcinogenesis, and may be activated by light exposure. These pathways may be modulated or inhibited by naturally-occurring compounds, such as the triterpenoid, ursolic acid (UA). Previously, the transcription factors p53 and NF-kB, which transactivate mitochondrial apoptosis-related genes, were shown to be differentially modulated by UA. Our current work indicates that UA causes these effects via the mTOR and insulin-mediated pathways. UA-modulated apoptosis, following exposure to UV radiation, is observed to correspond to differential levels of oxidative stress in retinal pigment epithelial (RPE) and skin melanoma (SM) cells. Flow cytometry analysis, DHE (dihydroethidium) staining and membrane permeability assay showed that UA pretreatment potentiated cell cycle arrest and radiation-induced apoptosis selectively on SM cells while DNA photo-oxidative damage (i.e. strand breakage) was reduced, presumably by some antioxidant activity of UA in RPE cells. The UA-mediated NF-?B activation in SM cells was reduced by rapamycin pretreatment, which indicates that these agents exert inter-antagonistic effects in the PI3K/Akt/mTOR pathway. In contrast, the antagonistic effect of UA on the PI3K/Akt pathway was reversed by insulin leading to greater NF-?B and p53 activation in RPE cells. MitoTracker, a mitochondrial functional assay, indicated that mitochondria in RPE cells experienced reduced oxidative stress while those in SM cells exhibited increased oxidative stress upon UA pretreatment. When rapamycin administration was followed by UA, mitochondrial oxidative stress was increased in RPE cells but decreased in SM cells. These results indicate that UA modulates p53 and NF-?B, initiating a mitogenic response to radiation that triggers mitochondria-dependent apoptosis.

  10. 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.

  11. The novel proteasome inhibitor carfilzomib activates and enhances extrinsic apoptosis involving stabilization of death receptor 5

    PubMed Central

    Han, Bo; Yao, Weilong; Oh, You-Take; Tong, Jing-Shan; Li, Shaohua; Deng, Jiusheng; Yue, Ping; Khuri, Fadlo R.; Sun, Shi-Yong

    2015-01-01

    Carfilzomib (CFZ) is a second generation proteasome inhibitor approved for the treatment of patients with multiple myeloma. It induces apoptosis in human cancer cells; but the underlying mechanisms remain undefined. In the present study, we show that CFZ decreases the survival of several human cancer cell lines and induces apoptosis. Induction of apoptosis by CFZ occurs, at least in part, due to activation of the extrinsic apoptotic pathway, since FADD deficiency protected cancer cells from undergoing apoptosis. CFZ increased total and cell surface levels of DR5 in different cancer cell lines; accordingly it enhanced TRAIL-induced apoptosis. DR5 deficiency protected cancer cells from induction of apoptosis by CFZ either alone or in combination with TRAIL. These data together convincingly demonstrate that DR5 upregulation is a critical mechanism accounting for CFZ-induced apoptosis and enhancement of TRAIL-induced apoptosis. CFZ inhibited the degradation of DR5, suggesting that DR5 stabilization contributes to CFZ-induced DR5 upregulation. In summary, the present study highlights the important role of DR5 upregulation in CFZ-induced apoptosis and enhancement of TRAIL-induced apoptosis in human cancer cells. PMID:26009898

  12. Calcium-sensing receptor induces rat neonatal ventricular cardiomyocyte apoptosis

    SciTech Connect

    Sun Yihua; Liu Meina; Li Hong; Shi Sa; Zhao Yajun; Wang Rui; Xu Changqing . E-mail: syh200415@yahoo.com.cn

    2006-12-01

    The calcium-sensing receptor (CaSR) exists in many tissues, and its expression has been identified in rat cardiac tissue. However, Physiological importance and pathophysiological involvement of CaSR in homeostatic regulation of cardiac function are unclear. To investigate the relation of CaSR and apoptosis in cardiomyocytes, we examined the role of the CaSR activator gadolinium chloride (GdCl{sub 3}) in rat neonatal ventricular cardiomyocytes. Expression of the CaSR protein was observed by Western blot. The apoptotic ratio of rat neonatal ventricular cardiomyocytes was measured with flow cytometry and immunofluorescence techniques. A laser scan confocal microscope was used to detect the intracellular concentration of calcium ([Ca{sup 2+}]{sub i}) in rat neonatal ventricular cardiomyocytes using the acetoxymethyl ester of fluo-3 (fluo-3/(AM)) as a fluorescent dye. The results showed that GdCl{sub 3} increased the phosphorylation of extracellular signal-regulated protein kinase (ERK), c-Jun NH{sub 2}-terminal protein kinases (JNK), and p38. GdCl{sub 3} also activated caspase 9 and increased apoptosis in myocyte by increasing [Ca{sup 2+}]{sub i}. In conclusion, these results suggest that CaSR promotes cardiomyocyte apoptosis in rat neonatal ventricular cardiomyocytes through activation of mitogen-activated protein kinases and caspase 9 signaling pathways.

  13. Genes associated with sodium fluoride-induced human osteoblast apoptosis

    PubMed Central

    Zhang, Ya-Lou; Luo, Qin; Deng, Qiang; Li, Tian; Li, Yan; Zhang, Zhi-Lu; Zhong, Jin-Jie

    2015-01-01

    This study aims to explore the potential pathways and molecular characteristics of fluorine-induced osteoblast apoptosis. In vitro fluorine-induced model was established with an osteogenesis sarcoma cell line Saos-2. Then flow cytometry was used to determine the mitochondrial membrane potential at 24 h after the intervention. 84 apoptosis-related genes in the cells were determined using the functional polymerase chain reaction (PCR) chip and part of the differentially expressed genes was verified with immune blotting. When the stimulated concentration of sodium fluoride were 20 mg/L, 40 mg/L and 80 mg/L, the mitochondrial membrane potential of the osteoblast cells were 27.0%, 28.8% and 38.6%, respectively, significantly higher than that in the blank control group (P<0.05). The PCR chip detection found 13 up-regulating genes and 15 down-regulating genes, among which the expression of Bim, Caspase 9, Caspase 14, B-cell lymphoma-2 (BCL2) and BAX increased with the doses of sodium fluoride, while the expression of Caspase 3 down-regulated in 5 mg/L sodium fluoride but up-regulated at the concentration of sodium fluoride more than 10 mg/L. Caspase 7 expression showed no obvious difference between the different concentration groups. However, Caspase 10 decreased with the increasing doses of sodium fluoride. Fluoride-induced osteoblast apoptosis may be through the mitochondrial pathway (including endoplasmic reticulum stress pathway) and death receptor pathway. PMID:26550240

  14. Apoptosis of postovulatory cumulus granulosa cells of the rat.

    PubMed

    Szo?tys, M; Tabarowski, Z; Pawlik, A

    2000-12-01

    The process of apoptosis in the postovulatory cumulus granulosa cells was investigated in pregnant rats. Mature female Wistar rats, exhibiting a regular 4-day oestrous cycle, were placed with males on the day of pro-oestrus. The following day, on which spermatozoa were found in vaginal smears, was designated day 1 of pregnancy. The animals were killed just before ovulation (24.00 hours), on days 1 (5.00, 11.00, and 18.00 hours), and 2 ( 11.00 hours) of pregnancy. Excised ovaries and oviducts were submitted to a routine histological procedure and paraplast sections were subjected to detection of apoptotic cells using the TUNEL method. The cumulus granulosa cells of preovulatory follicles (24.00 hours) were negative for apoptotic staining. However, 5 h later a positive staining was observed in the oviduct ampulla and included the cumulus granulosa cells lying in the peripheral parts of postovulatory cumuli oophori, and the oviductal epithelial cells of this region. On the evening of day 1 almost all cumulus granulosa cells showed strong immunostaining while on day 2 at 11.00 hours only immunonegative clusters of remnants of cumulus granulosa cells were present in the distended ampulla region, while naked, two or more cell embryos were present in the further parts of oviduct. These results indicate that in the rat apoptosis of cumulus granulosa cells starts shortly after ovulation in the peripheral region. Epithelial ampullary cells surrounding ovulated cumuli show a massive apoptosis. PMID:11131018

  15. Overexpression of PAX5 induces apoptosis in multiple myeloma cells.

    PubMed

    Proulx, Maryse; Cayer, Marie-Pierre; Drouin, Mathieu; Laroche, André; Jung, Daniel

    2010-10-01

    PAX5 is an essential transcription factor for the commitment of lymphoid progenitors to the B-lymphocyte lineage. PAX5 suppression results in retrodifferentiation of B lymphocytes to an uncommitted progenitor cell stage, whereas PAX5 suppression in mature B lymphocytes leads to further development into plasma cells. Here, we have analyzed the fate of plasma cell lines following PAX5 reexpression. Human B cell lines were infected with Ad5/F35 adenoviruses encoding either EYFP or PAX5. Expression analysis of specific plasma cell transcription factors (IRF4, Blimp-1 and XBP-1) suggests that PAX5 reexpression does not induce retrodifferentiation of plasma cells into B lymphocytes. Interestingly, the viability of RPMI-8226 and U266 multiple myeloma cell lines markedly declined at 4-7 days post-transduction, whereas other plasma cell lines maintained their viability. Apoptosis analysis through Annexin V measurement also revealed a higher level of apoptosis in PAX5-expressing myeloma cell lines. Finally, Western blot analysis of pro- and anti-apoptotic proteins revealed that the anti-apoptotic protein MCL-1 was down-modulated in PAX5-transduced multiple myeloma cell lines. In conclusion, our results show that the expression of PAX5 in plasma cell lines induces apoptosis exclusively in multiple myelomas. This might represent a potential therapeutic avenue in the treatment of multiple myeloma. PMID:20882442

  16. Intracellular GTP level determines cell's fate toward differentiation and apoptosis

    SciTech Connect

    Meshkini, Azadeh; Yazdanparast, Razieh Nouri, Kazem

    2011-06-15

    Since the adequate supply of guanine nucleotides is vital for cellular activities, limitation of their syntheses would certainly result in modulation of cellular fate toward differentiation and apoptosis. The aim of this study was to set a correlation between the intracellular level of GTP and the induction of relevant signaling pathways involved in the cell's fate toward life or death. In that regard, we measured the GTP level among human leukemia K562 cells exposed to mycophenolic acid (MPA) or 3-hydrogenkwadaphnin (3-HK) as two potent inosine monophosphate dehydrogenase inhibitors. Our results supported the maturation of the cells when the intracellular GTP level was reduced by almost 30-40%. Under these conditions, 3-HK and/or MPA caused up-regulation of PKC{alpha} and PI3K/AKT pathways. Furthermore, co-treatment of cells with hypoxanthine plus 3-HK or MPA, which caused a reduction of about 60% in the intracellular GTP levels, led to apoptosis and activation of mitochondrial pathways through inverse regulation of Bcl-2/Bax expression and activation of caspase-3. Moreover, our results demonstrated that attenuation of GTP by almost 60% augmented the intracellular ROS and nuclear localization of p21 and subsequently led to cell death. These results suggest that two different threshold levels of GTP are needed for induction of differentiation and/or ROS-associated apoptosis. - Graphical abstract: Display Omitted

  17. Positive feedback of protein kinase C proteolytic activation during apoptosis.

    PubMed Central

    Leverrier, Sabrina; Vallentin, Alice; Joubert, Dominique

    2002-01-01

    In contrast with protein kinase Calpha (PKCalpha) and PKCepsilon, which are better known for promoting cell survival, PKCdelta is known for its pro-apoptotic function, which is exerted mainly through a caspase-3-dependent proteolytic activation pathway. In the present study, we used the rat GH3B6 pituitary adenoma cell line to show that PKCalpha and PKCepsilon are activated and relocalized together with PKCdelta when apoptosis is induced by a genotoxic stress. Proteolytic activation is a crucial step used by the three isoforms since: (1) the catalytic domains of the PKCalpha, PKCepsilon or PKCdelta isoforms (CDalpha, CDepsilon and CDdelta respectively) accumulated, and this accumulation was dependent on the activity of both calpain and caspase; and (2) transient expression of CDalpha, CDepsilon or CDdelta sufficed to induce apoptosis. However, following this initial step of proteolytic activation, the pathways diverge; cytochrome c release and caspase-3 activation are induced by CDepsilon and CDdelta, but not by CDalpha. Another interesting finding of the present study is the proteolysis of PKCdelta induced by CDepsilon expression that revealed the existence of a cross-talk between PKC isoforms during apoptosis. Hence the PKC family may participate in the apoptotic process of pituitary adenoma cells at two levels: downstream of caspase and calpain, and via retro-activation of caspase-3, resulting in the amplification of its own proteolytic activation. PMID:12238950

  18. Early induction of calpains in rotenone-mediated neuronal apoptosis.

    PubMed

    Chen, Minghui Jessica; Yap, Yann Wan; Choy, Meng Shyan; Koh, Chor Hui Vivien; Seet, Sze Jee; Duan, Wei; Whiteman, Matthew; Cheung, Nam Sang

    Rotenone is an inhibitor of mitochondrial complex I that produces a model of Parkinson's disease (PD), where neurons undergo apoptosis by caspase-dependent and/or caspase-independent pathways. Inhibition of calpains has recently been shown to attenuate neuronal apoptosis. This study aims to establish for the first time, the time-point of calpain activation with respect to the caspase activation and the possibility of cell cycle re-entry in rotenone-mediated cell death. Immunoblot results revealed calpain activation occurred at 5, 10h prior to caspase-3 activation (at 15 h), suggesting calpain activation was an earlier cellular event compared to caspase activation in the rotenone-mediated apoptosis. In addition, an upregulation of phospho-p53 was observed at 21 h. However, no expression or upregulation of cell cycle regulatory proteins including cdc25a, cyclin-D1 and cyclin-D3 were observed, strongly suggesting that cell cycle re-entry did not occur. These findings provide new insights into the differential patterns of calpain and caspase activation that result from rotenone poisoning and which may be relevant to the therapeutic management of PD. PMID:16412576

  19. PARP1-Driven Apoptosis in Chronic Lymphocytic Leukemia

    PubMed Central

    Diamantopoulos, Panagiotis T.; Sofotasiou, Maria; Papadopoulou, Vasiliki; Polonyfi, Katerina; Iliakis, Theodoros; Viniou, Nora-Athina

    2014-01-01

    Chronic lymphocytic leukemia (CLL) is considered a malignancy resulting from defects in apoptosis. For this reason, targeting apoptotic pathways in CLL may be valuable for its management. Poly [ADP-ribose] polymerase 1 (PARP1) is the main member of a family of nuclear enzymes that act as DNA damage sensors. Through binding on DNA damaged structures, PARP1 recruits repair enzymes and serves as a survival factor, but if the damage is severe enough, its action may lead the cell to apoptosis through caspase activation, or necrosis. We measured the PARP1 mRNA and protein pretreatment levels in 26 patients with CLL and the corresponding posttreatment levels in 15 patients after 3 cycles of immunochemotherapy, as well as in 15 healthy blood donors. No difference was found between the pre- and posttreatment levels of PARP1, but we found a statistically significant relative increase of the 89?kDa fragment of PARP1 that is cleaved by caspases in the posttreatment samples, indicating PARP1-related apoptosis in CLL patients after treatment. Our findings constitute an important step in the field, especially in the era of PARP1 inhibitors, and may serve as a base for future clinical trials with these agents in CLL. PMID:25161998

  20. Cathepsin S silencing induces apoptosis of human hepatocellular carcinoma cells

    PubMed Central

    Wang, Xuedi; Xiong, Li; Yu, Guotang; Li, Dongdong; Peng, Tao; Luo, Daqing; Xu, Jing

    2015-01-01

    This study was to investigate the potential molecular mechanisms underlying the Cathepsin S (CTSS) silencing induced apoptosis of Hepatocellular Carcinoma (HCC) cells with lentivirus-mediated RNA interference. Real-time quantitative PCR and western blot assay were performed to detect the mRNA and protein expression of CTSS, respectively, in 13 HCC cell lines with different metastatic potentials. Results showed MHCC97-H cells had the highest CTSS expression. Therefore, MHCC97-H cells were used in following experiments. Then, lentivirus-mediated RNAi was employed to silence CTSS expression (shCTSS). Annexin V/FITC staining showed NF-?B was activated in shCTSS cells treated with conditioned medium from shCTSS-PAR2 cells. This implies a probable positive correlation between PAR2 and CTSS. In addition, results demonstrated CTSS induced apoptosis of HCC cells and increased their chemosensitivity via regulating NF-?B and activating cleaved caspase-3. Our results indicate that CTSS silencing by lentivirus mediated RNAi can significantly induce apoptosis and chemosensitivity of MHCC97-H cells. This provides an attractive anti-cancer strategy and a novel strategy for the treatment of human HCC. PMID:25755832

  1. Reactive Oxygen Species, Apoptosis, Antimicrobial Peptides and Human Inflammatory Diseases

    PubMed Central

    Oyinloye, Babatunji Emmanuel; Adenowo, Abiola Fatimah; Kappo, Abidemi Paul

    2015-01-01

    Excessive free radical generation, especially reactive oxygen species (ROS) leading to oxidative stress in the biological system, has been implicated in the pathogenesis and pathological conditions associated with diverse human inflammatory diseases (HIDs). Although inflammation which is considered advantageous is a defensive mechanism in response to xenobiotics and foreign pathogen; as a result of cellular damage arising from oxidative stress, if uncontrolled, it may degenerate to chronic inflammation when the ROS levels exceed the antioxidant capacity. Therefore, in the normal resolution of inflammatory reactions, apoptosis is acknowledged to play a crucial role, while on the other hand, dysregulation in the induction of apoptosis by enhanced ROS production could also result in excessive apoptosis identified in the pathogenesis of HIDs. Apparently, a careful balance must be maintained in this complex environment. Antimicrobial peptides (AMPs) have been proposed in this review as an excellent candidate capable of playing prominent roles in maintaining this balance. Consequently, in novel drug design for the treatment and management of HIDs, AMPs are promising candidates owing to their size and multidimensional properties as well as their wide spectrum of activities and indications of reduced rate of resistance. PMID:25850012

  2. Oxidized mitochondrial DNA activates the NLRP3 inflammasome during apoptosis.

    PubMed

    Shimada, Kenichi; Crother, Timothy R; Karlin, Justin; Dagvadorj, Jargalsaikhan; Chiba, Norika; Chen, Shuang; Ramanujan, V Krishnan; Wolf, Andrea J; Vergnes, Laurent; Ojcius, David M; Rentsendorj, Altan; Vargas, Mario; Guerrero, Candace; Wang, Yinsheng; Fitzgerald, Katherine A; Underhill, David M; Town, Terrence; Arditi, Moshe

    2012-03-23

    We report that in the presence of signal 1 (NF-?B), the NLRP3 inflammasome was activated by mitochondrial apoptotic signaling that licensed production of interleukin-1? (IL-1?). NLRP3 secondary signal activators such as ATP induced mitochondrial dysfunction and apoptosis, resulting in release of oxidized mitochondrial DNA (mtDNA) into the cytosol, where it bound to and activated the NLRP3 inflammasome. The antiapoptotic protein Bcl-2 inversely regulated mitochondrial dysfunction and NLRP3 inflammasome activation. Mitochondrial DNA directly induced NLRP3 inflammasome activation, because macrophages lacking mtDNA had severely attenuated IL-1? production, yet still underwent apoptosis. Both binding of oxidized mtDNA to the NLRP3 inflammasome and IL-1? secretion could be competitively inhibited by the oxidized nucleoside 8-OH-dG. Thus, our data reveal that oxidized mtDNA released during programmed cell death causes activation of the NLRP3 inflammasome. These results provide a missing link between apoptosis and inflammasome activation, via binding of cytosolic oxidized mtDNA to the NLRP3 inflammasome. PMID:22342844

  3. The mechanism of UVB irradiation induced-apoptosis in cataract.

    PubMed

    Ji, Yinghong; Cai, Lei; Zheng, Tianyu; Ye, Hongfei; Rong, Xianfang; Rao, Jun; Lu, Yi

    2015-03-01

    Cataract is the most common eye disease that causes blindness in patients. Ultraviolet B (UVB) irradiation is considered an important factor leading to cataract by inducing apoptosis in human lens epithelial cells (HLECs), but the mechanism is currently unclear. In this study, we investigated HLECs under different intensities of UVB irradiation and different exposure time. The annexin V-FITC/propidium iodide staining results showed that UVB irradiation could efficiently lead to HLECs apoptosis in time- and dose-dependent manner. The expression of pro-apoptotic Bax gene was promoted by UVB irradiation, while anti-apoptotic Bcl-2 gene expression was inhibited at both transcript and protein levels. Notably, the ratio of Bax/Bcl-2 displayed a high and positive correlation to the proportion of apoptotic HLECs. Mitochondrial dysfunction was also observed with rapid loss of potential (?? m), as well as changes of the levels of reactive oxygen species, malondialdehyde, total antioxidative capabilities, and superoxide dismutase. In caspase pathway, the level of caspase-3 protein increased after UVB irradiation. All these discovered changes may play important roles in UVB-induced HLECs apoptosis, and would be helpful in understanding the mechanism of UVB-induced cataract and providing potential prevention and treatment strategies. PMID:25445170

  4. GSK-3 Mouse Models to Study Neuronal Apoptosis and Neurodegeneration

    PubMed Central

    Gómez-Sintes, Raquel; Hernández, Félix; Lucas, José J.; Avila, Jesús

    2011-01-01

    Increased GSK-3 activity is believed to contribute to the etiology of chronic disorders like Alzheimer’s disease (AD), schizophrenia, diabetes, and some types of cancer, thus supporting therapeutic potential of GSK-3 inhibitors. Numerous mouse models with modified GSK-3 have been generated in order to study the physiology of GSK-3, its implication in diverse pathologies and the potential effect of GSK-3 inhibitors. In this review we have focused on the relevance of these mouse models for the study of the role of GSK-3 in apoptosis. GSK-3 is involved in two apoptotic pathways, intrinsic and extrinsic pathways, and plays opposite roles depending on the apoptotic signaling process that is activated. It promotes cell death when acting through intrinsic pathway and plays an anti-apoptotic role if the extrinsic pathway is occurring. It is important to dissect this duality since, among the diseases in which GSK-3 is involved, excessive cell death is crucial in some illnesses like neurodegenerative diseases, while a deficient apoptosis is occurring in others such as cancer or autoimmune diseases. The clinical application of a classical GSK-3 inhibitor, lithium, is limited by its toxic consequences, including motor side effects. Recently, the mechanism leading to activation of apoptosis following chronic lithium administration has been described. Understanding this mechanism could help to minimize side effects and to improve application of GSK-3 inhibitors to the treatment of AD and to extend the application to other diseases. PMID:22110426

  5. Infection by Mycobacterium tuberculosis promotes human alveolar macrophage apoptosis.

    PubMed Central

    Keane, J; Balcewicz-Sablinska, M K; Remold, H G; Chupp, G L; Meek, B B; Fenton, M J; Kornfeld, H

    1997-01-01

    The effect of Mycobacterium tuberculosis infection on the viability of healthy (control) human alveolar macrophages was evaluated by staining with ethidium homodimer and calcein to discriminate live from dead cells. Infection with M. tuberculosis H37Ra or H37Rv increased macrophage mortality at 6 days from the control level of 3.8% +/- 0.7% to 28.7% +/- 6.9% or 12.6% +/- 3.1%, respectively (P < 0.001 for comparisons of all conditions). A role for tumor necrosis factor alpha (TNF-alpha) in the M. tuberculosis-induced cytolysis of alveolar macrophages was demonstrated by increased cytotoxicity following the addition of exogenous TNF-alpha to the cultures and by enhancement of macrophage survival when M. tuberculosis-infected alveolar macrophages were treated with pentoxifylline or anti-TNF-alpha antibody. The cytolytic mechanism was determined to be apoptosis by the demonstration of a characteristic internucleosomal ladder of genomic DNA by agarose gel electrophoresis, by finding nuclear fragmentation and condensation by electron microscopy, and by in situ terminal transferase-mediated nick end labeling of fragmented DNA in alveolar macrophages infected with M. tuberculosis in vitro. The latter technique was employed to reveal extensive apoptosis within caseating granulomas from lung tissue samples from clinical tuberculosis cases. The induction of apoptosis in alveolar macrophages by M. tuberculosis may play a role in the macrophage-pathogen interaction of tuberculosis in vivo. PMID:8975927

  6. Hepatocyte apoptosis in dairy cattle during the transition period

    PubMed Central

    Tharwat, Mohamed; Takamizawa, Aya; Hosaka, Yoshinao Z.; Endoh, Daiji; Oikawa, Shin

    2012-01-01

    The objective of this study was to investigate hepatocyte apoptosis in dairy cows during the transition period. Four clinically healthy, pregnant dairy cattle were used. The cows had no clinical diseases throughout this study. Blood samples were collected and livers were biopsied from the cows at 3 different times: 3 weeks before expected partition (wk ?3); during parturition (wk 0), and 3 weeks (wk +3) after parturition. The damage to deoxyribonucleic acid (DNA) caused by hepatocytes was evaluated by comet assay. The apoptotic features of hepatocytes were examined by immunohistochemistry and electron microscopic analyses. The hepatic triglyceride content markedly increased at wk 0 and wk +3 compared with the values at wk ?3. The results of the comet assay showed increases in the mean tail moment values of hepatic cells after parturition in all cows, which suggested increased DNA damage. Histopathologically, the hepatocytes began to contain lipid droplets at wk 0 and were severely opacified at wk +3. Caspase-3-positive and single-stranded DNA-(ssDNA)-positive cells were first detected in the liver after parturition. Condensation of nuclear chromatin, a typical sign of apoptosis, was confirmed by transmission electron microscopy after parturition. These results suggest that apoptosis is induced in hepatocytes of dairy cows around parturition and may result from lipotoxicity in hepatocytes. PMID:23543948

  7. Effect of lipopolysaccharide on the hemocyte apoptosis of Eriocheir sinensis *

    PubMed Central

    Xu, Hai-sheng; Lyu, Sun-jian; Xu, Jie-hao; Lu, Bin-jie; Zhao, Jing; Li, Song; Li, Yi-qun; Chen, Yu-yin

    2015-01-01

    In the present study, we investigated the possible toxicity mechanism of lipopolysaccharide (LPS) extracted from Gram-negative bacteria in Eriocheir sinensis hemocytes. Apoptotic hemocytes and reactive oxygen species (ROS) production induced by the LPS were monitored by the combination of flow cytometry and microscope observation. It was shown that LPS induced serious damage on the DNA and morphological changes in hemocytes, including cell shrinkage, fracture of nucleus membrane, margination, condensation and fragmentation of chromatin, and formation of apoptotic bodies indicating obvious hemocyte apoptosis. As compared with the control group, the apoptotic cell ratio increased to 30.61% and 39.01% after 1-h exposure and 57.72% and 75.01% after 2-h exposure to 1 and 10 ?g/ml LPS, respectively (P<0.05). Significant outburst of ROS production was observed in LPS-treated hemocytes with approximately 176.6% of relative dichlorofluorescein mean fluorescence at 1-h exposure, followed by a drastic decline (P<0.05). These results indicated that LPS would induce oxidative stress on hemocytes from E. sinensis and cause ROS burst, DNA damage, and subsequently apoptosis. The process of ROS-mediated apoptosis might be one of the potential toxicity mechanisms of LPS on crustacean hemocytes. PMID:26642180

  8. Reactive oxygen species, apoptosis, antimicrobial peptides and human inflammatory diseases.

    PubMed

    Oyinloye, Babatunji Emmanuel; Adenowo, Abiola Fatimah; Kappo, Abidemi Paul

    2015-01-01

    Excessive free radical generation, especially reactive oxygen species (ROS) leading to oxidative stress in the biological system, has been implicated in the pathogenesis and pathological conditions associated with diverse human inflammatory diseases (HIDs). Although inflammation which is considered advantageous is a defensive mechanism in response to xenobiotics and foreign pathogen; as a result of cellular damage arising from oxidative stress, if uncontrolled, it may degenerate to chronic inflammation when the ROS levels exceed the antioxidant capacity. Therefore, in the normal resolution of inflammatory reactions, apoptosis is acknowledged to play a crucial role, while on the other hand, dysregulation in the induction of apoptosis by enhanced ROS production could also result in excessive apoptosis identified in the pathogenesis of HIDs. Apparently, a careful balance must be maintained in this complex environment. Antimicrobial peptides (AMPs) have been proposed in this review as an excellent candidate capable of playing prominent roles in maintaining this balance. Consequently, in novel drug design for the treatment and management of HIDs, AMPs are promising candidates owing to their size and multidimensional properties as well as their wide spectrum of activities and indications of reduced rate of resistance. PMID:25850012

  9. TGF? Signaling Promotes Juvenile Granulosa Cell Tumorigenesis by Suppressing Apoptosis

    PubMed Central

    Mansouri-Attia, Nadéra; Tripurani, Swamy K.; Gokul, Nisha; Piard, Hermann; Anderson, Matthew L.; Eldin, Karen

    2014-01-01

    Molecular changes that give rise to granulosa cell tumors of the ovary are not well understood. Previously, we showed that deletion in granulosa cells of the bone morphogenetic protein receptor-signaling transcription factors, Smad1 and Smad5, causes development of metastatic granulosa cell tumors that phenocopy the juvenile form of granulosa cell tumors (JGCTs) in humans. The TGF?-SMAD2/3 pathway is active in JGCTs, but its role is unknown. We tested the in vivo contribution of TGF?-SMAD signaling to JGCT development by genetically deleting the common Smad4 from Smad1/5 double knockout mice. Smad1/5/4 triple knockout mice were sterile and had significantly increased survival and delayed tumor development compared to those for the Smad1/5 double knockout mice. The few tumors that did develop were smaller, showed no evidence of metastasis, and had increased apoptosis. In the human JGCT cell line COV434, TGF?1 increased viability by inhibiting apoptosis through a TGF? type I receptor–dependent repression of caspase activity and inhibition of poly(ADP-ribose) polymerase cleavage. These data support a tumor-promoting function of TGF? in JGCTs through its ability to repress apoptosis. PMID:25243859

  10. Lipopolysaccharide induced apoptosis of rat pancreatic acinar cells.

    PubMed Central

    Laine, V J; Nyman, K M; Peuravuori, H J; Henriksen, K; Parvinen, M; Nevalainen, T J

    1996-01-01

    BACKGROUND--Bacterial lipopolysaccharide (LPS) has been proposed to participate in the pathogenesis of pancreatic inflammatory disease. AIMS--This study investigated the role of endotoxaemia in the pathogenesis of pancreatic acinar cell injury. METHODS--Sixty eight male Spraque-Dawley rats were used in the study. Escherichia coli LPS (5 mg/kg) was injected into the peritoneal cavity of the rats. The concentration of pancreatic phospholipase A2 (PLA2) in plasma was measured and pancreatic tissue examined by histology, in situ detection of free DNA 3'-ends, and electrophoretic DNA analysis. RESULTS--The concentration of pancreatic PLA2 increased in plasma and the catalytic activity of PLA2 increased in pancreatic tissue after an LPS injection. Apoptosis in pancreatic acinar cells and fragmentation of DNA typical of apoptosis in pancreatic tissue was seen 24 hours after an LPS injection. Pancreatic acinar atrophy was seen 72 hours after the LPS injection. CONCLUSIONS--These data show that LPS causes release of pancreatic PLA2 into blood plasma, activation of PLA2 in pancreatic tissue, and apoptosis of acinar cells. Images Figure 3 Figure 4 Figure 5 PMID:8707123

  11. p53 upregulated modulator of apoptosis sensitizes drug-resistant U251 glioblastoma stem cells to temozolomide through enhanced apoptosis.

    PubMed

    Miao, Wang; Liu, Xiaodong; Wang, Hongqin; Fan, Yimin; Lian, Shizhong; Yang, Xin; Wang, Xinxing; Guo, Geng; Li, Qichao; Wang, Sifei

    2015-06-01

    Malignant glioma is a highly aggressive brain tumor with a poor prognosis. Chemotherapy has been observed to prolong overall survival rate and temozolomide (TMZ), a promising chemotherapeutic agent for treating glioblastoma (GBM), possesses the most effective clinical activity at present, although drug resistance limits its clinical outcome. Growing evidence supports the concept that initial and recurrent GBM may derive from glioblastoma stem cells, which may be responsible for drug resistance. However, the molecular mechanisms underlying this resistance remain to be elucidated. In the present study, a TMZ?resistant GBM cell line, U251R, was developed and subsequently divided into two subpopulations according to the CD133 immunophenotype. No significant difference was identified in the expression of O6?methylguanine?DNA?methyltransferase (MGMT) between CD133+ U251R cells and CD133? U251R cells, whereas the CD133+ cell population was more resistant to TMZ?induced growth inhibition and cell death. TMZ achieves its cytotoxic effect by inducing DNA lesions and p53 upregulated modulator of apoptosis (PUMA) is an essential mediator of DNA damage?induced apoptosis independently of p53 status. Therefore, whether PUMA effectively enhances growth suppression and induces apoptosis when combined with TMZ was investigated. Consequently, it was found that adenoviruses expressing wild?type?PUMA not only lead to the apoptosis of CD133+ U251R cells alone, but also significantly increase their sensitivity toward TMZ by elevating the Bcl?2?associated X protein/B?cell lymphoma?2 ratio without alterations in MGMT expression. Therefore, PUMA may be a suitable target for intervention to improve the therapeutic ef?cacy of TMZ. PMID:25625235

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

    PubMed Central

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

    2015-01-01

    AIM: To evaluate the efficacy of ursodeoxycholic acid (UDCA) as a chemotherapeutic agent for the treatment of hepatocellular carcinoma (HCC). METHODS: BALB/c nude mice were randomized into four groups 24 h before subcutaneous injection of hepatocarcinoma BEL7402 cells suspended in phosphate buffered saline (PBS) into the right flank. The control group (n = 10) was fed a standard diet while treatment groups (n = 10 each) were fed a standard daily diet supplemented with different concentrations of UDCA (30, 50 and 70 mg/kg per day) for 21 d. Tumor growth was measured once each week, and tumor volume (V) was calculated with the following equation: V = (L × W2) × 0.52, where L is the length and W is the width of the xenograft. After 21 d, mice were killed under ether anesthesia, and tumors were excised and weighed. Apoptosis was evaluated through detection of DNA fragmentation with gel electrophoresis and the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay. Western blot analysis was performed to determine the expression of apoptosis-related proteins BAX, BCL2, APAF1, cleaved caspase-9, and cleaved caspase-3. RESULTS: UDCA suppressed tumor growth relative to controls. The mean tumor volumes were the following: control, 1090 ± 89 mm3; 30 mg/kg per day, 612 ± 46 mm3; 50 mg/kg per day, 563 ± 38 mm3; and 70 mg/kg per day, 221 ± 26 mm3. Decreased tumor volumes reached statistical significance relative to control xenografts (30 mg/kg per day, P < 0.05; 50 mg/kg per day, P < 0.05; 70 mg/kg per day, P < 0.01). Increasing concentrations of UDCA led to increased DNA fragmentation observed on gel electrophoresis and in the TUNEL assay (control, 1.6% ± 0.3%; 30 mg/kg per day, 2.9% ± 0.5%; 50 mg/kg per day, 3.15% ± 0.7%, and 70 mg/kg per day, 4.86% ± 0.9%). Western blot analysis revealed increased expression of BAX, APAF1, cleaved-caspase-9 and cleaved-caspase-3 proteins, which induce apoptosis, but decreased expression of BCL2 protein, which is an inhibitor of apoptosis, following administration of UDCA. CONCLUSION: UDCA suppresses growth of BEL7402 hepatocellular carcinoma cells in vivo, in part through apoptosis induction, and is thus a candidate for therapeutic treatment of HCC. PMID:26420963

  13. 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, apoptosis: (i) requires entry and endocytosis of virions or virion proteins, (ii) is inhibited under conditions permitting early viral expression, and (iii) requires the JNK signaling pathway. This is the first report of JNK signal requirement during apoptosis induction by an insect virus.

  14. Crystal structure of caspase recruiting domain (CARD) of apoptosis repressor with CARD (ARC) and its implication in inhibition of apoptosis

    PubMed Central

    Jang, Tae-ho; Kim, Seong Hyun; Jeong, Jae-Hee; Kim, Sunghwan; Kim, Yeun Gil; Park, Hyun Ho

    2015-01-01

    Apoptosis repressor with caspase recruiting domain (ARC) is a multifunctional inhibitor of apoptosis that is unusually over-expressed or activated in various cancers and in the state of the pulmonary hypertension. Therefore, ARC might be an optimal target for therapeutic intervention. Human ARC is composed of two distinct domains, N-terminal caspase recruiting domain (CARD) and C-terminal P/E (proline and glutamic acid) rich domain. ARC inhibits the extrinsic apoptosis pathway by interfering with DISC formation. ARC CARD directly interacts with the death domains (DDs) of Fas and FADD, as well as with the death effector domains (DEDs) of procaspase-8. Here, we report the first crystal structure of the CARD domain of ARC at a resolution of 2.4 Å. Our structure was a dimer with novel homo-dimerization interfaces that might be critical to its inhibitory function. Interestingly, ARC did not exhibit a typical death domain fold. The sixth helix (H6), which was detected at the typical death domain fold, was not detected in the structure of ARC, indicating that H6 may be dispensable for the function of the death domain superfamily. PMID:26038885

  15. Characterization of an inhibitor of apoptosis protein in Crassostrea gigas clarifies its role in apoptosis and immune defense.

    PubMed

    Qu, Tao; Zhang, Linlin; Wang, Wei; Huang, Baoyu; Li, Yingxiang; Zhu, Qihui; Li, Li; Zhang, Guofan

    2015-07-01

    The inhibitor of apoptosis (IAP) proteins maintain a balance between cell proliferation and cell death by inhibiting caspase activity and facilitating immune responses. In this study, phylogenetic analysis revealed lineage-specific expansion and tandem duplication of IAPs in the Pacific oyster Crassostrea gigas. We then investigated a representative oyster-specific XIAP-like gene (CgIAP2) to understand how it regulates initiator caspase. Cloning of full-length CgIAP2 from oyster cDNA uncovered a deduced protein containing two BIR domains and a RING domain. Homolog comparison demonstrated that CgIAP2 clustered into the invertebrate branch. We found that CgIAP2 was likely involved in apoptosis inhibition and immune defense, based on high mRNA expression in the gills and labial palps, as well as increased mRNA expression after bacterial challenge. A yeast two-hybrid assay revealed that the BIR2 domain was necessary and sufficient to mediate interaction between CgIAP2 and Cgcaspase-2, providing direct evidence that CgIAP2 participates in apoptosis inhibition. PMID:25720977

  16. Mathematical modeling identified c-FLIP as an apoptotic switch in death receptor induced apoptosis.

    PubMed

    Han, Lihui; Zhao, Yishu; Jia, Xiaoqing

    2008-10-01

    Apoptosis is an essential process to get rid of injured or unwanted cells. In this study, we proposed a mathematical modeling for death receptor mediated apoptosis to investigate the role of c-FLIP in controlling the balance between apoptosis and survival. In order to get insight into how NF-kappa B mediated pro-survival pathway affects the outcome of our modeling, we implemented reduced models without taking such regulation into consideration. Our simulation revealed that c-FLIP could act as a pivotal death or life switch and this switch-like behavior is bistable, irreversible, and robust. We introduce a new term, probability apoptosis, to delineate the likelihood in occurrence of apoptosis events. This simulation system is plausible and may offer several valuable clinical indications for the abnormal apoptosis related disease, such as cancer. PMID:18726189

  17. Galectin-3 leads to attenuation of apoptosis through Bax heterodimerization in human thyroid carcinoma cells

    PubMed Central

    Harazono, Yosuke; Kho, Dhong Hyo; Balan, Vitaly; Nakajima, Kosei; Zhang, Tianpeng; Hogan, Victor; Raz, Avraham

    2014-01-01

    Cancer cells survive escaping normal apoptosis and the blocks in apoptosis that keep cancer cells alive are promising candidates for targeted therapy. Galectin-3 (Gal-3) is, a member of the lectin family, which is involved in cell growth, adhesion, proliferation and apoptosis. It remains elusive to understand the role of Gal-3 on apoptosis in thyroid carcinoma cells. Here, we report that Gal-3 heterodimerizes Bax, mediated by the carbohydrate recognition domain (CRD) of Gal-3, leading to anti-apoptotic characteristic. Gal-3/Bax interaction was suppressed by an antagonist of Gal-3, in which in turn cells became sensitive to apoptosis. The data presented here highlight that Gal-3 is involved in the anti-apoptosis of thyroid carcinoma cells. Thus, it suggests that targeting Gal-3 may lead to an improved therapeutic modality for thyroid cancer. PMID:25393982

  18. Identifying Novel Candidate Genes Related to Apoptosis from a Protein-Protein Interaction Network

    PubMed Central

    Wang, Baoman; Yuan, Fei; Kong, Xiangyin; Hu, Lan-Dian; Cai, Yu-Dong

    2015-01-01

    Apoptosis is the process of programmed cell death (PCD) that occurs in multicellular organisms. This process of normal cell death is required to maintain the balance of homeostasis. In addition, some diseases, such as obesity, cancer, and neurodegenerative diseases, can be cured through apoptosis, which produces few side effects. An effective comprehension of the mechanisms underlying apoptosis will be helpful to prevent and treat some diseases. The identification of genes related to apoptosis is essential to uncover its underlying mechanisms. In this study, a computational method was proposed to identify novel candidate genes related to apoptosis. First, protein-protein interaction information was used to construct a weighted graph. Second, a shortest path algorithm was applied to the graph to search for new candidate genes. Finally, the obtained genes were filtered by a permutation test. As a result, 26 genes were obtained, and we discuss their likelihood of being novel apoptosis-related genes by collecting evidence from published literature. PMID:26543496

  19. Resistance to apoptosis should not be taken as a hallmark of cancer

    PubMed Central

    Wang, Rui-An; Li, Zeng-Shan; Yan, Qing-Guo; Bian, Xiu-Wu; Ding, Yan-Qing; Du, Xiang; Sun, Bao-Cun; Sun, Yun-Tian; Zhang, Xiang-Hong

    2014-01-01

    In the research community, resistance to apoptosis is often considered a hallmark of cancer. However, pathologists who diagnose cancer via microscope often see the opposite. Indeed, increased apoptosis and mitosis are usually observed simultaneously in cancerous lesions. Studies have shown that increased apoptosis is associated with cancer aggressiveness and poor clinical outcome. Furthermore, overexpression of Bcl-2, an antiapoptotic protein, is linked with better survival of cancer patients. Conversely, Bax, CD95, Caspase-3, and other apoptosis-inducing proteins have been found to promote carcinogenesis. This notion of the role of apoptosis in cancer is not new; cancer cells were found to be short-lived 88 years ago. Given these observations, resistance to apoptosis should not be considered a hallmark of cancer. PMID:24417874

  20. Apoptosis in pressure overload-induced heart hypertrophy in the rat.

    PubMed Central

    Teiger, E; Than, V D; Richard, L; Wisnewsky, C; Tea, B S; Gaboury, L; Tremblay, J; Schwartz, K; Hamet, P

    1996-01-01

    Pressure overload induces cardiac growth in the rat, which implies the hypertrophy of cardiac muscle cells and proliferation of nonmuscle cells. The cardiac cell loss observed in parallel has generally been attributed to necrosis. Using an in situ assay, we demonstrated a phase of apoptosis or programmed cell death during the first 7 d after pressure overload with a peak at day 4 while cardiac growth continued for over 30 d. The increase in apoptosis was confirmed by quantification of 180-1500-bp DNA oligonucleosomes with agarose gel electrophoresis and in situ labeling via 3'-terminal deoxynucleotidyl transferase assay. While some apoptosis was observed in the basal state in nonmuscle cells, pressure overload induced apoptosis mainly in cardiomyocytes. These data suggest that cardiac hypertrophy is initiated by a wave of apoptosis of cardiomyocytes. Thus, apoptosis may be involved in the pathogenesis of heart remodeling. PMID:8675703

  1. Validation and uncertainties evaluation of an isotope dilution-SPE-LC-MS/MS for the quantification of drug residues in surface waters.

    PubMed

    Brieudes, V; Lardy-Fontan, S; Lalere, B; Vaslin-Reimann, S; Budzinski, H

    2016-01-01

    The present work describes the development and validation of a reference method conducted at the French National Institute of Metrology (LNE) for the quantitative determination of psychoactive compounds in the dissolved fraction of surface waters. More specifically an isotope dilution-SPE-LC-MS/MS based method has been implemented for the characterization of a broad range of analytes belonging to different classes of psychotropic drugs such as benzodiazepines, antidepressants, stimulants, opiates and opioids, anticonvulsants, anti-dementia drugs, analgesics as well as the anti-inflammatory drug diclofenac in the low ngL(-1) range of concentration. Full validation of the method was performed following procedures described by the French standard NF T90-210. Limits of quantification between 0.14 and 3.54ngL(-1) were obtained. Method recoveries from 71 to 123% were observed with standard deviation below 10% in intermediate precision conditions. Accuracy was determined for every compound: measurement errors were between -4 and +1% and standard deviations in intermediate precision conditions were included within a 1-9% interval. Finally, measurement uncertainties were evaluated following the Guide to the expression of uncertainty in measurement (GUM). Expanded uncertainties (k=2) ranged from 2% for carbamazepine, EDDP (2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine) and venlafaxine to 17% for diazepam. The validated method was implemented to Seine river surface waters demonstrating its fitness for purpose. All compounds were detected and 22 out of 25 analytes were quantified. More specifically, measured concentration ranged from 0.39ngL(-1) for MDMA (3,4-methylene-dioxy-N-methylamphetamine) to 182ngL(-1) for gabapentine. PMID:26695245

  2. Apoptosis Modulation as a Promising Target for Treatment of Systemic Sclerosis

    PubMed Central

    Chabaud, Stéphane; Moulin, Véronique J.

    2011-01-01

    Diffuse systemic sclerosis (SSc) is a fatal autoimmune disease characterized by an excessive ECM deposition inducing a loss of function of skin and internal organs. Apoptosis is a key mechanism involved in all the stages of the disease: vascular damage, immune dysfunction, and fibrosis. The purpose of this paper is to gather new findings in apoptosis related to SSc, to highlight relations between apoptosis and fibrosis, and to identify new therapeutic targets. PMID:21912551

  3. Arylquins Target Vimentin to Trigger Par-4 Secretion for Tumor Cell Apoptosis

    PubMed Central

    Hebbar, Nikhil; Zhang, Wen; Layton, W. John; Hamza, Adel; Zhan, Chang-Guo; Watt, David S.; Liu, Chunming; Rangnekar, Vivek M.

    2014-01-01

    The tumor suppressor protein Par-4, which is secreted by normal cells, selectively induces apoptosis in cancer cells. We identified a 3-arylquinoline derivative, designated Arylquin 1, as a potent Par-4 secretagogue in cell cultures and mice. Mechanistically, Arylquin 1 binds to vimentin, displaces Par-4 from vimentin for secretion and triggers the efficient paracrine apoptosis of diverse cancer cells. Thus, targeting vimentin with Par-4 secretagogues efficiently induces paracrine apoptosis of tumor cells. PMID:25218743

  4. Up-regulation of CYLD enhances Listeria monocytogenes induced apoptosis in THP-1 cells.

    PubMed

    Xu, Changzhi; Yang, Ling; Yuan, Yuan; Du, Fei; Wang, Shumin; Wang, Xiangfang; Zhu, Lin; Zhang, Buchang; Weaver, David

    2016-01-01

    Listeria monocytogenes (Lm), a facultative anaerobic gram-positive bacterium, causes listeriosis. Immune cell apoptosis is considered to be one pathogenic factor for listeriosis. As a deubiquitinase, CYLD is an important regulator both in innate immune response and apoptosis by negatively modulating NF-?B pathway. However the role of CYLD in Lm induced apoptosis remains unclear. Here we found that CYLD is significantly up-regulated in macrophages upon its infection. There is a moderate decrease in Lm proliferation and apoptotic cells in siRNA-induced CYLD knockdown THP-1 cells. Thereby CYLD may be involved in cell apoptosis mediated by Lm infection and its proliferation. PMID:26545866

  5. RETINOID-INDUCED APOPTOSIS AND PROLIFERATION OF HEPATOCYTES ARE MEDIATED BY DISTINCT NUCLEAR RECEPTORS

    E-print Network

    Bu, Pengli

    2009-04-07

    Retinoids, derivatives of vitamin A, are important signaling molecules regulating cellular homeostasis including differentiation, apoptosis, and proliferation. In this dissertation, we examined the versatile effects of ...

  6. Impact of apoptosis on the on-line measured dielectric properties of CHO cells.

    PubMed

    Zalai, Dénes; Tobak, Teodóra; Putics, Ákos

    2015-12-01

    Apoptosis is a common type of cell death in biopharmaceutical cell culture processes which causes decrease in viable cell density and product yield. The progression of apoptosis has been reported to influence the dielectric properties of mammalian cells; however, the on-line detection of these effects has been rarely described. This study provides a comprehensive analysis of the on-line detectability of dielectric changes upon apoptosis induction in an industrial fed-batch process of CHO cells expressing a recombinant monoclonal antibody. Using capacitance signals, measured at 25 frequencies, the impact of apoptosis on the dielectric spectra was investigated in eight bioreactor cultivations in which various process conditions were combined with two different apoptosis induction strategies (camptothecin treatment and glucose starvation). To differentiate the apoptosis-related information from the cell concentration-associated variance in the multivariate capacitance datasets, principal component analysis (PCA) was used. A second principal component, explaining an explicit proportion (>20 %) of the variance, was identified to be related to dielectric changes induced by apoptosis. Furthermore, the analysis of caspase-3 and -7 activation and DNA fragmentation showed that the detected dielectric change occurred in the early phase of apoptosis. The presented results verify that apoptosis has a considerable impact on the dielectric features of CHO cells and it can be monitored on-line with the introduced tool-set combining capacitance measurement with multivariate data analysis. PMID:26440966

  7. Genetically Encoded Fluorescent Probe for Imaging Apoptosis in Vivo with Spontaneous GFP Complementation.

    PubMed

    Nasu, Yusuke; Asaoka, Yoichi; Namae, Misako; Nishina, Hiroshi; Yoshimura, Hideaki; Ozawa, Takeaki

    2016-01-01

    Apoptosis plays a pivotal role in development and tissue homeostasis in multicellular organisms. Dysfunction of apoptosis is involved in many fatal diseases such as cancer. Visualization of apoptosis in living animals is necessary to understand the mechanism of apoptosis-related diseases. Here, we describe a genetically encoded fluorescent probe for imaging apoptosis in living multicellular organisms, based on spontaneous complementation of two fragments of a green fluorescent protein (GFP) variant (GFP OPT). The probe is designed for detection of mitochondria-mediated apoptosis during which a mitochondrial protein of Smac is released into cytosol. The Smac is connected with a carboxy-terminal fragment of GFP OPT (GFP11), whereas the remainder of GFP OPT (GFP1-10) is located in the cytosol. Under an apoptotic condition, the Smac is released from mitochondria into cytosol, allowing complementation of the GFP-OPT fragments and the emission of fluorescence. Live-cell imaging demonstrates that the probe enables detection of apoptosis in living cells with a high signal-to-background ratio. We applied the probe to living zebrafish, in which apoptotic cells were visualized with fluorescence. The technique provides a useful tool for the study of apoptosis in living animals, facilitating elucidation of the mechanisms of apoptosis-related diseases. PMID:26597767

  8. Control of apoptosis by the BCL-2 protein family: implications for physiology and therapy.

    PubMed

    Czabotar, Peter E; Lessene, Guillaume; Strasser, Andreas; Adams, Jerry M

    2014-01-01

    The BCL-2 protein family determines the commitment of cells to apoptosis, an ancient cell suicide programme that is essential for development, tissue homeostasis and immunity. Too little apoptosis can promote cancer and autoimmune diseases; too much apoptosis can augment ischaemic conditions and drive neurodegeneration. We discuss the biochemical, structural and genetic studies that have clarified how the interplay between members of the BCL-2 family on mitochondria sets the apoptotic threshold. These mechanistic insights into the functions of the BCL-2 family are illuminating the physiological control of apoptosis, the pathological consequences of its dysregulation and the promising search for novel cancer therapies that target the BCL-2 family. PMID:24355989

  9. Nonsteroidal anti-inflammatory drugs induce apoptosis in cutaneous T-cell lymphoma cells and enhance their sensitivity for TNF-related apoptosis-inducing ligand.

    PubMed

    Braun, Frank K; Al-Yacoub, Nadya; Plötz, Michael; Möbs, Markus; Sterry, Wolfram; Eberle, Jürgen

    2012-02-01

    Cutaneous T-cell lymphomas (CTCL) form a heterogeneous group of non-Hodgkin's lymphomas of the skin. In previous studies, we had characterized CTCL cells as resistant to the death ligand tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), which correlated to pronounced expression of the caspase-8/-10 inhibitor c-FLIP. For identification of proapoptotic strategies in CTCL cells and for overcoming their death ligand resistance, we investigated the effects of nonsteroidal anti-inflammatory drugs (NSAIDs) such as acetylsalicylic acid, sodium salicylate, and diclofenac (DF). These drugs strongly enhanced apoptosis, as well as decreased CTCL cell proliferation and vitality, and DF furthermore sensitized for TRAIL-induced apoptosis. Full activation of the caspase cascade (caspase-3, -8, -9) and decreased mitochondrial membrane potential were characteristic for NSAID treatment, whereas cytochrome c release was seen only for DF. Downregulation of Mcl-1 and enhanced surface expression of TRAIL were seen in response to NSAIDs. Most characteristic for apoptosis induction was the downregulation of c-FLIP. In agreement with the critical role of c-FLIP for apoptosis deficiency of CTCL cells, its overexpression decreased NSAID-mediated apoptosis and its downregulation by small hairpin RNA-enhanced apoptosis. The study provides a rationale for the use of NSAIDs as a new therapeutic option for CTCL patients. Supporting this concept, ex vivo lymphoma cells of CTCL patients also revealed significant sensitivity for NSAID treatment. PMID:22011910

  10. Nitric oxide involvement in pancreatic beta cell apoptosis by glibenclamide.

    PubMed

    Ansar, Malek Moien; Ansari, Mohammad

    2006-02-01

    Glibenclamide as a second-generation compound of sulfonylurea has widely been used in the treatment of type 2 diabetes patients. It has been shown that it induces apoptosis in beta cells, which is partially mediated by Ca(2+) influx. Here, we investigated the role of nitric oxide (NO) and nitric oxide synthase (NOS) isoforms on glibenclamide-induced apoptosis in rat insulinoma cells. Our results showed that glibenclamide induces NO generation (measured as nitrite) that is accompanied with decrease of cell viability in a defined concentration of glibenclamide. The effects of glibenclamide on cell viability were partially inhibited after treatment with N(G)-nitro-L-arginine methyl ester (L-NAME), inhibitor more selective for constitutive nitric oxide synthase, and in the presence of D600--a blocker of voltage-gated L-type Ca(2+) channels inhibited Ca(2+) influx into beta cells, whereas aminoguanidine (AG), a preferential inhibitor of inducible NOS, was significantly less effective. Analysis of DNA fragmentation by electrophoresis and staining with Hoechest 33342 and propidium iodide showed that L-NAME, but not AG, prevented DNA fragmentation and decreased the number of cells with condensed and fragmented nuclei. It revealed that the effects of glibenclamide on apoptosis were partially inhibited by treatment with L-NAME. In conclusion, we have shown that NO production in glibenclamide treated cells may be involved in the induction of apoptotic cell death in pure beta cell line and it may be due to Ca(2+) dependent activation of constitutive NOS isoforms. PMID:16256381

  11. The function of Drosophila p53 isoforms in apoptosis.

    PubMed

    Zhang, B; Rotelli, M; Dixon, M; Calvi, B R

    2015-12-01

    The p53 protein is a major mediator of the cellular response to genotoxic stress and is a crucial suppressor of tumor formation. In a variety of organisms, p53 and its paralogs, p63 and p73, each encode multiple protein isoforms through alternative splicing, promoters, and translation start sites. The function of these isoforms in development and disease are still being defined. Here, we evaluate the apoptotic potential of multiple isoforms of the single p53 gene in the genetic model Drosophila melanogaster. Most previous studies have focused on the p53A isoform, but it has been recently shown that a larger p53B isoform can induce apoptosis when overexpressed. It has remained unclear, however, whether one or both isoforms are required for the apoptotic response to genotoxic stress. We show that p53B is a much more potent inducer of apoptosis than p53A when overexpressed. Overexpression of two newly identified short isoforms perturbed development and inhibited the apoptotic response to ionizing radiation. Analysis of physiological protein expression indicated that p53A is the most abundant isoform, and that both p53A and p53B can form a complex and co-localize to sub-nuclear compartments. In contrast to the overexpression results, new isoform-specific loss-of-function mutants indicated that it is the shorter p53A isoform, not full-length p53B, that is the primary mediator of pro-apoptotic gene transcription and apoptosis after ionizing radiation. Together, our data show that it is the shorter p53A isoform that mediates the apoptotic response to DNA damage, and further suggest that p53B and shorter isoforms have specialized functions. PMID:25882045

  12. Effect of quercetin on apoptosis of PANC-1 cells

    PubMed Central

    Lee, Joo Hyun; Lee, Han-Beom; Jung, Gum O; Oh, Jung Taek; Park, Dong Eun

    2013-01-01

    Purpose To investigate the chemotherapeutic effect of quercetin against cancer cells, signaling pathway of apoptosis was explored in human pancreatic cells. Methods Various anticancer drugs including adriamycin, cisplatin, 5-fluorouracil (5-FU) and gemcitabine were used. Cell viability was measured by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphe-nyltetra zolium bromide assay. Apoptosis was determined by 4'-6-diamidino-2-phenylindole nuclei staining and flow cytometry in PANC-1 cells treated with 50 µg/mL quercetin for 24 hours. Expression of endoplas mic reticulum (ER) stress mediators including, Grp78/Bip, p-PERK, PERK, ATF4, ATF6 and GADD153/CHOP proteins were measured by Western blot analysis. Mitochondrial membrane potential was measured by fluorescence staining with JC-1, rhodamine 123. Quercetin induced the apoptosis of PANC-1, which was characterized as nucleic acid and genomic DNA fragmentation, chromatin condensation, and sub-G0/G1 fraction of cell cycle increase. But not adriamycin, cisplatin, gemcitabine, and 5-FU. PANC-1 cells were markedly sensitive to quercetin. Results Treatment with quercetin resulted in the increased accumulation of intracellular Ca2+ ion. Treatment with quercetin also increased the expression of Grp78/Bip and GADD153/CHOP protein and induced mitochondrial dysfunction. Quercetin exerted cytotoxicity against human pancreatic cancer cells via ER stress-mediated apoptotic signaling including reactive oxygen species production and mitochondrial dysfunction. Conclusion These data suggest that quercetin may be an important modulator of chemosensitivity of cancer cells against anticancer chemotherapeutic agents. PMID:24368982

  13. Apoptosis in Candida biofilms exposed to amphotericin B.

    PubMed

    Al-Dhaheri, Rawya S; Douglas, L Julia

    2010-02-01

    Candida biofilms are resistant to a range of antifungal agents in current clinical use. The basis of this drug resistance is not clear, but in some cases it could be due to the presence of a small number of drug-tolerant or persister cells. In this study, specific staining methods were used to investigate the existence of persisters and apoptosis in Candida biofilms subjected to different concentrations of amphotericin B. Fluorescein diacetate staining revealed the presence of persisters in biofilms of one of two strains of Candida albicans tested, and in biofilms of Candida krusei and Candida parapsilosis. Caspase activity, indicative of apoptosis, was detected with SR-FLICA and (aspartyl)(2)-rhodamine 110 fluorochrome-based staining reagents in all of these biofilms. The general inhibitor of mammalian caspases, Z-VAD-FMK, when used at a low concentration (2.5 microM), increased the viability of drug-treated biofilms up to 11.5-fold (P <0.001 %). Seven specific caspase inhibitors had different effects on C. albicans biofilm viability, but inhibitors of caspases-1, -9, -5, -3 and -2 all significantly increased cell survival (40-fold, 8-fold, 3.5-fold, 1.9-fold and 1.7-fold, respectively). However, histone deacetylase (HDA) inhibitors enhanced the activity of amphotericin B for biofilms of all three Candida species. Sodium butyrate and sodium valproate, for example, when added concurrently with amphotericin B, completely eliminated biofilm populations of C. albicans. Overall, our results demonstrate an apoptotic process in amphotericin-treated biofilms of three Candida species. They also indicate that HDA inhibitors can enhance the action of the drug and in some cases even eradicate persister subpopulations, suggesting that histone acetylation might activate apoptosis in these cells. PMID:19892857

  14. Melatonin and endoplasmic reticulum stress: relation to autophagy and apoptosis.

    PubMed

    Fernández, Anna; Ordóñez, Raquel; Reiter, Russel J; González-Gallego, Javier; Mauriz, José L

    2015-10-01

    Endoplasmic reticulum (ER) is a dynamic organelle that participates in a number of cellular functions by controlling lipid metabolism, calcium stores, and proteostasis. Under stressful situations, the ER environment is compromised, and protein maturation is impaired; this causes misfolded proteins to accumulate and a characteristic stress response named unfolded protein response (UPR). UPR protects cells from stress and contributes to cellular homeostasis re-establishment; however, during prolonged ER stress, UPR activation promotes cell death. ER stressors can modulate autophagy which in turn, depending of the situation, induces cell survival or death. Interactions of different autophagy- and apoptosis-related proteins and also common signaling pathways have been found, suggesting an interplay between these cellular processes, although their dynamic features are still unknown. A number of pathologies including metabolic, neurodegenerative and cardiovascular diseases, cancer, inflammation, and viral infections are associated with ER stress, leading to a growing interest in targeting components of the UPR as a therapeutic strategy. Melatonin has a variety of antioxidant, anti-inflammatory, and antitumor effects. As such, it modulates apoptosis and autophagy in cancer cells, neurodegeneration and the development of liver diseases as well as other pathologies. Here, we review the effects of melatonin on the main ER stress mechanisms, focusing on its ability to regulate the autophagic and apoptotic processes. As the number of studies that have analyzed ER stress modulation by this indole remains limited, further research is necessary for a better understanding of the crosstalk between ER stress, autophagy, and apoptosis and to clearly delineate the mechanisms by which melatonin modulates these responses. PMID:26201382

  15. Deguelin promotes apoptosis and inhibits angiogenesis of gastric cancer.

    PubMed

    Lee, Hyunseung; Lee, Ju-Hee; Jung, Kyung Hee; Hong, Soon-Sun

    2010-10-01

    Gastric cancer is often diagnosed in locally advanced or metastatic stages, which preludes a poor prognosis. As only 10% of patients with advanced gastric cancer treated with chemotherapy survive 2 years, new approaches for preventing and controlling the disease are required. We therefore, assessed in gastric cancer cells the chemotherapeutic potential and mechanism of deguelin, a rotenoid of the flavonoid family isolated from several plant species. The effect of deguelin on the proliferation and apoptosis in the gastric cancer cells were assessed by MTT and flow cytometry. The growth of gastric cancer cells (SNU-484, AGS and MKN-28) was inhibited by deguelin in a dose-dependent manner. G2/M phase arrest was induced by deguelin in gastric cancer cells. deguelin (1 microM) induced chromatin condensation and DNA fragmentation. Also the exposure to 1 microM deguelin resulted in the increase in early-apoptotic cells (Annexin V-positive/Propidium iodide-negative) after 24 h, compared to the cells in the control medium (31 versus 12%). Deguelin-induced apoptosis involved the caspase-9 and caspase-3 pathways in gastric cancer cells. Akt phosphorylation, hypoxia-inducible factor-1alpha accumulation, and vascular endothelial growth factor expression in gastric cancer cells was inhibited by deguelin. Taken together, deguelin showed anticancer activity in gastric cancer cells, which is correlated with the inhibition of angiogenesis and induction of apoptosis. Deguelin may be a potential agent in inhibiting the progression of gastric cancer by virtue of its activity on these crucial cell characteristics. PMID:20811676

  16. 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-? 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-?, 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 apoptosis. Blood TNF-?, IL-6 and SPP1 may be more sensitive injure indicators. PMID:26550144

  17. Characterization of chronic HCV infection-induced apoptosis

    PubMed Central

    2011-01-01

    Background To understand the complex and largely not well-understood apoptotic pathway and immune system evasion mechanisms in hepatitis C virus (HCV)-associated hepatocellular carcinoma (HCC) and HCV associated chronic hepatitis (CH), we studied the expression patterns of a number of pro-apoptotic and anti-apoptotic genes (Fas, FasL, Bcl-2, Bcl-xL and Bak) in HepG2 cell line harboring HCV- genotype-4 replication. For confirmation, we also assessed the expression levels of the same group of genes in clinical samples obtained from 35 HCC and 34 CH patients. Methods Viral replication was assessed in the tissue culture medium by RT-PCR, quantitative Real-Time PCR (qRT-PCR); detection of HCV core protein by western blot and inhibition of HCV replication with siRNA. The expression level of Fas, FasL, Bcl-2, Bcl-xL and Bak was assessed by immunohistochemistry and RT-PCR whereas caspases 3, 8 and 9 were assessed by colorimetric assay kits up to 135 days post infection. Results There was a consistent increase in apoptotic activity for the first 4 weeks post-CV infection followed by a consistent decrease up to the end of the experiment. The concordance between the changes in the expression levels of Fas, FasL, Bcl-2, Bcl-xL and Bak in vitro and in situ was statistically significant (p < 0.05). Fas was highly expressed at early stages of infection in cell lines and in normal control liver tissues followed by a dramatic reduction post-HCV infection and an increase in the expression level of FasL post HCV infection. The effect of HCV infection on other apoptotic proteins started very early post-infection, suggesting that hepatitis C modulating apoptosis by modulating intracellular pro-apoptotic signals. Conclusions Chronic HCV infection differently modulates the apoptotic machinery during the course of infection, where the virus induces apoptosis early in the course of infection, and as the disease progresses apoptosis is modulated. This study could open a new opportunity for understanding the various signaling of apoptosis and in the developing a targeted therapy to inhibit viral persistence and HCC development. PMID:21781333

  18. Apoptosis and Self-Destruct: A Contribution to Autonomic Agents?

    NASA Technical Reports Server (NTRS)

    Sterritt, Roy; Hinchey, Mike

    2004-01-01

    Autonomic Computing (AC), a self-managing systems initiative based on the biological metaphor of the autonomic nervous system, is increasingly gaining momentum as the way forward in designing reliable systems. Agent technologies have been identified as a key enabler for engineering autonomicity in systems, both in terms of retrofitting autonomicity into legacy systems and designing new systems. The AC initiative provides an opportunity to consider other biological systems and principles in seeking new design strategies. This paper reports on one such investigation; utilizing the apoptosis metaphor of biological systems to provide a dynamic health indicator signal between autonomic agents.

  19. Modeled microgravity inhibits apoptosis in peripheral blood lymphocytes

    NASA Technical Reports Server (NTRS)

    Risin, D.; Pellis, N. R.; McIntire, L. V. (Principal Investigator)

    2001-01-01

    Microgravity interferes with numerous lymphocyte functions (expression of cell surface molecules, locomotion, polyclonal and antigen-specific activation, and the protein kinase C activity in signal transduction). The latter suggests that gravity may also affect programmed cell death (PCD) in lymphocyte populations. To test this hypothesis, we investigated spontaneous, activation- and radiation-induced PCD in peripheral blood mononuclear cells exposed to modeled microgravity (MMG) using a rotating cell culture system. The results showed significant inhibition of radiation- and activation-induced apoptosis in MMG and provide insights into the potential mechanisms of this phenomenon.

  20. Glycolaldehyde induces apoptosis in a human breast cancer cell line.

    PubMed

    Al-Maghrebi, May A; Al-Mulla, Fahd; Benov, Ludmil T

    2003-09-01

    Activated phagocytes employ myeloperoxidase to generate glycolaldehyde, 2-hydroxypropanal, and acrolein. Because alpha-hydroxy and alpha,beta-unsaturated aldehydes are highly reactive, phagocyte-mediated formation of these products may play a role in killing bacteria and tumor cells. Using breast cancer cells, we demonstrate that glycolaldehyde inactivates glucose-6-phosphate dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, and Cu,Zn superoxide dismutase, suppresses cell growth, and induces apoptosis. These results suggest that glycolaldehyde might be an important mediator of neutrophil anti-tumor activity. PMID:12921788

  1. Modeled Microgravity Inhibits Apoptosis in Peripheral Blood Lymphocytes

    NASA Technical Reports Server (NTRS)

    Risin, Diana; Pellis, Neal R.

    2000-01-01

    Microgravity interferes with numerous lymphocyte functions (expression of cell surface molecules, locomotion, polyclonal and antigen-specific activation, and the protein kinase C activity in signal transduction). The latter suggests that gravity may also affect programmed cell death (PCD) in lymphocyte populations. To test this hypothesis, we investigated spontaneous, activation- and radiation-induced PCD in peripheral blood mononuclear cells (PBMC) exposed to modeled microgravity using a rotating cell culture system. The results showed significant inhibition of radiation- and activation-induced apoptosis in modeled microgravity and provide insights into the potential mechanisms of this phenomenon.

  2. MicroRNA-137 Negatively Regulates H2O2-Induced Cardiomyocyte Apoptosis Through CDC42

    PubMed Central

    Wang, Junnan; Xu, Rihao; Wu, Junduo; Li, Zhibo

    2015-01-01

    Background Oxidative stress, inducing cardiomyocyte apoptosis or myocardial ischemia, is the major denominator of many cardiac diseases. In this study, we intended to explore the regulatory function of microRNA-137 (miR-137) in oxidative stress-induced cardiomyocyte apoptosis. Material/Methods Cardiomyocytes were extracted from newborn C57BL/6 mice and cultured in vitro. Apoptosis was induced by H2O2, and evaluated by TUNEL assay. The effect of cardiomyocyte apoptosis on gene expression of miR-137 was evaluated by qRT-PCR. Lentivirus was used to stably down-regulate miR-137, and the subsequent effects of miR-137 down-regulation on cardiomyocyte apoptosis, its targeted gene CDC42, and caspase pathway were evaluated by TUNEL assay, dual-luciferase reporter assay, and Western blot assay, respectively. Finally, CDC42 was down-regulated by siRNA and its effect on miR-137-mediated cardiomyocyte apoptosis protection was examined. Results H2O2 induced significant apoptosis and up-regulated miR-137 in cardiomyocytes, whereas lentivirus-mediated miR-137 down-regulation protected against apoptosis. CDC42 was the direct target gene of miR-137 and proteins of CDC42, caspase-3, and caspase-9 were all regulated by miR-137 down-regulation in cardiomyocyte apoptosis. SiRNA-mediated CDC42 down-regulation reversed the protection of miR-137 down-regulation against cardiomyocyte apoptosis. Conclusions Our work demonstrated miR-137 and CDC42 are critical regulators in cardiomyocyte apoptosis. It may help to identify the molecular targets to prevent myocardial injury in human patients. PMID:26566162

  3. The Mitochondria-Mediate Apoptosis of Lepidopteran Cells Induced by Azadirachtin

    PubMed Central

    Huang, Jingfei; Lv, Chaojun; Hu, Meiying; Zhong, Guohua

    2013-01-01

    Mitochondria have been shown to play an important role in apoptosis using mammalian cell lines. However, this seems not to be the case in Drosophila, an insect model organism; thus more in-depth studies of insect cell apoptosis are necessary. In the present study, mitochondrial involvement during azadirachtin- and camptothecin-induced apoptosis in Spodoptera frugiperda Sf9 cells (isolated from Spodoptera frugiperda pupal ovarian tissue) was investigated. The results showed that both azadirachtin and camptothecin could induce apoptosis in Sf9 cells. Reactive oxygen species (ROS) generation, activation of mitochondrial permeability transition pores (MPTPs) and loss of mitochondrial membrane potential (MMP) were observed very early during apoptosis and were followed subsequently by the release of cytochrome-c from the mitochondria. Furthermore, the results also revealed that the opening of MPTPs and the loss of MMP induced by azadirachtin could be significantly inhibited by the permeability transition pore (PTP) inhibitor cyclosporin A (CsA), which was used to identify the key role of mitochondria in the apoptosis of Sf9 cells. However, in camptothecin-treated Sf9 cells, CsA could not suppress the opening of MPTPs and the loss of MMP when apoptosis was induced. The data from caspase-3 and caspase-9 activity assays and detection of apoptosis by morphological observation and flow cytometry also uncovered the different effect of CsA on the two botanical apoptosis inducers. Although different mechanisms of apoptosis induction exist, our study revealed that mitochondria play a crucial role in insect cell line apoptosis. PMID:23516491

  4. Acetyl-11-keto-beta-boswellic acid potentiates apoptosis, inhibits invasion, and abolishes osteoclastogenesis by suppressing NF-kappa B and NF-kappa B-regulated gene expression.

    PubMed

    Takada, Yasunari; Ichikawa, Haruyo; Badmaev, Vladimir; Aggarwal, Bharat B

    2006-03-01

    Acetyl-11-keto-beta-boswellic acid (AKBA), a component of an Ayurvedic therapeutic plant Boswellia serrata, is a pentacyclic terpenoid active against a large number of inflammatory diseases, including cancer, arthritis, chronic colitis, ulcerative colitis, Crohn's disease, and bronchial asthma, but the mechanism is poorly understood. We found that AKBA potentiated the apoptosis induced by TNF and chemotherapeutic agents, suppressed TNF-induced invasion, and inhibited receptor activator of NF-kappaB ligand-induced osteoclastogenesis, all of which are known to require NF-kappaB activation. These observations corresponded with the down-regulation of the expression of NF-kappaB-regulated antiapoptotic, proliferative, and angiogenic gene products. As examined by DNA binding, AKBA suppressed both inducible and constitutive NF-kappaB activation in tumor cells. It also abrogated NF-kappaB activation induced by TNF, IL-1beta, okadaic acid, doxorubicin, LPS, H2O2, PMA, and cigarette smoke. AKBA did not directly affect the binding of NF-kappaB to the DNA but inhibited sequentially the TNF-induced activation of IkappaBalpha kinase (IKK), IkappaBalpha phosphorylation, IkappaBalpha ubiquitination, IkappaBalpha degradation, p65 phosphorylation, and p65 nuclear translocation. AKBA also did not directly modulate IKK activity but suppressed the activation of IKK through inhibition of Akt. Furthermore, AKBA inhibited the NF-kappaB-dependent reporter gene expression activated by TNFR type 1, TNFR-associated death domain protein, TNFR-associated factor 2, NF-kappaB-inducing kinase, and IKK, but not that activated by the p65 subunit of NF-kappaB. Overall, our results indicated that AKBA enhances apoptosis induced by cytokines and chemotherapeutic agents, inhibits invasion, and suppresses osteoclastogenesis through inhibition of NF-kappaB-regulated gene expression. PMID:16493072

  5. Peroxiredoxin 1 suppresses apoptosis via regulation of the apoptosis signal-regulating kinase 1 signaling pathway in human oral leukoplakia

    PubMed Central

    ZHANG, MIN; NIU, WENWEN; ZHANG, JIANFEI; GE, LIHUA; YANG, JING; SUN, ZHENG; TANG, XIAOFEI

    2015-01-01

    Peroxiredoxin 1 (Prx1) has a significant role in several malignant types of tumor. However, the role of Prx1 in oral leukoplakia (OLK) has remained to be elucidated. OLK is a common precancerous lesion of the oral mucosa that has a very high malignant transformation rate. The aim of the present study was to investigate the roles of Prx1, and its association with apoptosis signal-regulating kinase 1 (ASK1) and p38 in OLK. A total of 20 OLK samples and 10 normal oral mucosa samples were obtained from patients at the Beijing Stomatological Hospital (Beijing, China). The messenger RNA (mRNA) and protein expression levels of Prx1, ASK1 and p38 were determined by polymerase chain reaction and western blot analysis, respectively. Flow cytometry was used to detect cell apoptosis. The interaction between Prx1 and ASK1 was examined in H2O2-treated DOK cells by glutathione-S-transferase pull-down assays and by co-immunoprecipitation in vitro. Compared with those of the normal oral mucosa, the mRNA levels of Prx1, ASK1 and p38 were elevated in OLK tissues (P<0.05). The protein expression levels of Prx1, phosphorylated-ASK1 (p-ASK1) and p-p38 were also significantly enhanced in OLK tissues compared with those of the normal mucosa (P<0.05). In Prx1-knockdown DOK cells, ASK1 and p38 were activated, leading to enhanced levels of apoptosis in response to H2O2. No clear interaction between Prx1 and ASK1 was detected in H2O2-treated DOK cells. Prx1 was suggested to be involved in OLK pathogenesis by providing resistance against extracellular damages from oxidative stress via inhibition of the ASK1-induced apoptotic signaling pathway. Targeting Prx1 may provide a novel therapeutic strategy for the treatment of patients with OLK.

  6. Evidence that tumor necrosis factor-related apoptosis inducing ligand (TRAIL) inhibits angiogenesis by inducing vascular endothelial cell apoptosis

    SciTech Connect

    Chen, Pei-Lin; Easton, Alexander S.

    2010-01-01

    Tumor necrosis factor (TNF) and its related ligands TNF-related apoptosis inducing ligand (TRAIL) and Fas ligand (FasL) play roles in the regulation of vascular responses, but their effect on the formation of new blood vessels (angiogenesis) is unclear. Therefore, we have examined the effects of these ligands on angiogenesis modeled with primary cultures of human umbilical vein endothelial cells (HUVEC). To examine angiogenesis in the context of the central nervous system, we have also modeled cerebral angiogenesis with the human brain endothelial cell line hCMEC/D3. Parameters studied were bromodeoxyuridine (BrdU) incorporation and cell number (MTT) assay (to assess endothelial proliferation), scratch assay (migration) and networks on Matrigel (tube formation). In our hands, neither TRAIL nor FasL (1, 10, and 100 ng/ml) had an effect on parameters of angiogenesis in the HUVEC model. In hCMEC/D3 cells by contrast, TRAIL inhibited all parameters (10-100 ng/ml, 24 h). This was due to apoptosis, since its action was blocked by the pan-caspase inhibitor zVADfmk (5 x 10{sup -5} mol/l) and TRAIL increased caspase-3 activity 1 h after application. However FasL (100 ng/ml) increased BrdU uptake without other effects. We conclude that TRAIL has different effects on in vitro angiogenesis depending on which model is used, but that FasL is generally ineffective when applied in vitro. The data suggest that TRAIL primarily influences angiogenesis by the induction of vascular endothelial apoptosis, leading to vessel regression.

  7. FAQ IRB questions (includes SPE

    Cancer.gov

    September 12, 2008 Prepared and distributed by the Pharmaceutical Management Branch, CTEP, NCI. Please do not re-distribute or post without permission. Information in this FAQ is subject to change without notice; check periodically for updates.

  8. Nuclear events of apoptosis in vitro in cell-free mitotic extracts: a model system for analysis of the active phase of apoptosis

    PubMed Central

    1993-01-01

    We have developed a cell-free system that induces the morphological transformations characteristic of apoptosis in isolated nuclei. The system uses extracts prepared from mitotic chicken hepatoma cells following a sequential S phase/M phase synchronization. When nuclei are added to these extracts, the chromatin becomes highly condensed into spherical domains that ultimately extrude through the nuclear envelope, forming apoptotic bodies. The process is highly synchronous, and the structural changes are completed within 60 min. Coincident with these morphological changes, the nuclear DNA is cleaved into a nucleosomal ladder. Both processes are inhibited by Zn2+, an inhibitor of apoptosis in intact cells. Nuclear lamina disassembly accompanies these structural changes in added nuclei, and we show that lamina disassembly is a characteristic feature of apoptosis in intact cells of mouse, human and chicken. This system may provide a powerful means of dissecting the biochemical mechanisms underlying the final stages of apoptosis. PMID:8408207

  9. Stressed to death: implication of lymphocyte apoptosis for psychoneuroimmunology

    NASA Technical Reports Server (NTRS)

    Shi, Yufang; Devadas, Satish; Greeneltch, Kristy M.; Yin, Deling; Allan Mufson, R.; Zhou, Jian-nian

    2003-01-01

    Psychological and physical stressors best exemplify the intercommunication of the immune and the nervous systems. It has been shown that stress significantly impacts leukocyte cellularity and immune responses and alters susceptibility to various diseases. While acute stress has been shown to enhance immune responses, chronic stress often leads to immunosuppression. Among many criteria examined upon exposure to chronic stress, the reduction in lymphocyte mitogenic response and lymphocyte cellularity are commonly assessed. We have reported that chronic restraint stress could induce lymphocyte reduction, an effect dependent on endogenous opioids. Interestingly, the effect of endogenous opioids was found to be exerted through increasing the expression of a cell death receptor, Fas, and an increased sensitivity of lymphocytes to apoptosis. Stress-induced lymphocyte reduction was not affected by adrenalectomy. In this review, based on available literature and our recent data, we will discuss the role of the hypothalamic-pituitary-adrenal axis and endogenous opioids and examine the mechanisms by which chronic stress modulates lymphocyte apoptosis.

  10. 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

  11. 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.

  12. TIPIN depletion leads to apoptosis in breast cancer cells.

    PubMed

    Baldeyron, Céline; Brisson, Amélie; Tesson, Bruno; Némati, Fariba; Koundrioukoff, Stéphane; Saliba, Elie; De Koning, Leanne; Martel, Elise; Ye, Mengliang; Rigaill, Guillem; Meseure, Didier; Nicolas, André; Gentien, David; Decaudin, Didier; Debatisse, Michelle; Depil, Stéphane; Cruzalegui, Francisco; Pierré, Alain; Roman-Roman, Sergio; Tucker, Gordon C; Dubois, Thierry

    2015-10-01

    Triple-negative breast cancer (TNBC) is the breast cancer subgroup with the most aggressive clinical behavior. Alternatives to conventional chemotherapy are required to improve the survival of TNBC patients. Gene-expression analyses for different breast cancer subtypes revealed significant overexpression of the Timeless-interacting protein (TIPIN), which is involved in the stability of DNA replication forks, in the highly proliferative associated TNBC samples. Immunohistochemistry analysis showed higher expression of TIPIN in the most proliferative and aggressive breast cancer subtypes including TNBC, and no TIPIN expression in healthy breast tissues. The depletion of TIPIN by RNA interference impairs the proliferation of both human breast cancer and non-tumorigenic cell lines. However, this effect may be specifically associated with apoptosis in breast cancer cells. TIPIN silencing results in higher levels of single-stranded DNA (ssDNA), indicative of replicative stress (RS), in TNBC compared to non-tumorigenic cells. Upon TIPIN depletion, the speed of DNA replication fork was significantly decreased in all BC cells. However, TIPIN-depleted TNBC cells are unable to fire additional replication origins in response to RS and therefore undergo apoptosis. TIPIN knockdown in TNBC cells decreases tumorigenicity in vitro and delays tumor growth in vivo. Our findings suggest that TIPIN is important for the maintenance of DNA replication and represents a potential treatment target for the worst prognosis associated breast cancers, such as TNBC. PMID:26004086

  13. Regulation of the Intrinsic Apoptosis Pathway by Reactive Oxygen Species

    PubMed Central

    Wu, Chu-Chiao

    2013-01-01

    Abstract Significance: The intrinsic apoptosis pathway is conserved from worms to humans and plays a critical role in the normal development and homeostatic control of adult tissues. As a result, numerous diseases from cancer to neurodegeneration are associated with either too little or too much apoptosis. Recent Advances: B cell lymphoma-2 (BCL-2) family members regulate cell death, primarily via their effects on mitochondria. In stressed cells, proapoptotic BCL-2 family members promote mitochondrial outer membrane permeabilization (MOMP) and cytochrome c (cyt c) release into the cytoplasm, where it stimulates formation of the “apoptosome.” This large, multimeric complex is composed of the adapter protein, apoptotic protease-activating factor-1, and the cysteine protease, caspase-9. Recent studies suggest that proteins involved in the processes leading up to (and including) formation of the apoptosome are subject to various forms of post-translational modification, including proteolysis, phosphorylation, and in some cases, direct oxidative modification. Critical Issues: Despite intense investigation of the intrinsic pathway, significant questions remain regarding how cyt c is released from mitochondria, how the apoptosome is formed and regulated, and how caspase-9 is activated within the complex. Future Directions: Further studies on the biochemistry of MOMP and apoptosome formation are needed to understand the mechanisms that underpin these critical processes, and novel animal models will be necessary in the future to ascertain the importance of the many posttranslational modifications reported for BCL-2 family members and components of the apoptosome. Antioxid. Redox Signal. 19, 546–558. PMID:22978471

  14. 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.; Synvolux therapeutics, Groningen ; 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.

  15. Specific antibodies induce apoptosis in Trypanosoma cruzi epimastigotes.

    PubMed

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

    2010-05-01

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

  16. Host cell apoptosis impairs Cryptosporidium parvum development in vitro.

    PubMed

    Widmer, G; Corey, E A; Stein, B; Griffiths, J K; Tzipori, S

    2000-10-01

    The absence of a self-sustaining in vitro propagation method for Cryptosporidium parvum is a major obstacle for research on this parasite. Conventional cell monolayers are unsuitable for long-term parasite propagation because the level of infection decreases over time and few oocysts, if any, are produced. The interaction between parasite and host cell was studied to identify factors limiting parasite development in vitro. Loss of substrate adherence and death of parasitized host cells was observed in 2 epithelial cell lines. Nuclear morphology, DNA laddering, annexin V binding, and terminal deoxytransferase-mediated dUTP nick end labeling indicated that host cell death occurred by apoptosis. At 6 hr postinfection, only a minority of infected cells remained in the monolayer, and few survived the initial phase of parasite development without losing adherence. Treatment of infected monolayers with caspase inhibitors drastically reduced cell detachment but failed to increase the number of parasites in monolayers. In contrast, cell cultures grown on laminin-coated plates showed a higher proportion of infected cells. These observations indicate that cell detachment and apoptosis in C. parvum-infected cell culture negatively affect parasite survival in vitro. PMID:11128511

  17. Apoptosis related protein 3 is a lysosomal membrane protein.

    PubMed

    Ding, XiaoDong; Chen, YuanWen; Han, LianShu; Qiu, WenJuan; Gu, XueFan; Zhang, HuiWen

    2015-05-15

    Apoptosis Related Protein 3 (APR3) is an important protein which is involved in retinoic acid-induced apoptosis, osteoblast differentiation and cervical squamous cell carcinoma progression. Although it was predicted to be a trans-membrane protein, its cellular localization is not clear. In this study, we analyzed APR3 with bioinformatic tools and found that APR3 contains a potential signal peptide, a transmembrane region and 3 N-glycosylation sites, all of which are characteristics of lysosomal proteins. Western blot with isolated lysosomes demonstrated that APR3 was mainly present in lysosomes, specially in the lysosomal membrane fraction, but not in endoplasmic reticulum. Concomitantly, double immunofluorescence confirmed that APR3 co-localized with lysosomal membrane protein, LAMP1, as well as lysosomal specific marker, Lyso-Tracker Red. Moreover, we showed that APR3 was highly expressed in the lung, liver, spleen, kidney and adipose tissue, but expressed at the low level in the heart, pancreas, stomach and intestine. Interestingly, APR3 expression was elevated in multiple hepatocellular carcinoma cell lines comparing to normal liver cells. Collectively, our results proved that APR3 is a novel lysosomal membrane protein and shed light on its possible functions. PMID:25839652

  18. Apoptosis during embryonic tissue remodeling is accompanied by cell senescence

    PubMed Central

    Lorda-Diez, Carlos I.; Garcia-Riart, Beatriz; Montero, Juan A.; Rodriguez-León, Joaquín; Garcia-Porrero, Juan A; Hurle, Juan M.

    2015-01-01

    This study re-examined the dying process in the interdigital tissue during the formation of free digits in the developing limbs. We demonstrated that the interdigital dying process was associated with cell senescence, as deduced by induction of ?-gal activity, mitotic arrest, and transcriptional up-regulation of p21 together with many components of the senescence-associated secretory phenotype. We also found overlapping domains of expression of members of the Btg/Tob gene family of antiproliferative factors in the regressing interdigits. Notably, Btg2 was up-regulated during interdigit remodeling in species with free digits but not in the webbed foot of the duck. We also demonstrate that oxidative stress promoted the expression of Btg2, and that FGF2 and IGF1 which are survival signals for embryonic limb mesenchyme inhibited Btg2 expression. Btg2 overexpression in vivo and in vitro induced all the observed changes during interdigit regression, including oxidative stress, arrest of cell cycle progression, transcriptional regulation of senescence markers, and caspase-mediated apoptosis. Consistent with the central role of p21 on cell senescence, the transcriptional effects induced by overexpression of Btg2 are attenuated by silencing p21. Our findings indicate that cell senescence and apoptosis are complementary processes in the regression of embryonic tissues and share common regulatory signals. PMID:26568417

  19. Resveratrol Induces Glioma Cell Apoptosis through Activation of Tristetraprolin.

    PubMed

    Ryu, Jinhyun; Yoon, Nal Ae; Seong, Hyemin; Jeong, Joo Yeon; Kang, Seokmin; Park, Nammi; Choi, Jungil; Lee, Dong Hoon; Roh, Gu Seob; Kim, Hyun Joon; Cho, Gyeong Jae; Choi, Wan Sung; Park, Jae-Yong; Park, Jeong Woo; Kang, Sang Soo

    2015-11-30

    Tristetraprolin (TTP) is an AU-rich elements (AREs)-binding protein, which regulates the decay of AREs-containing mRNAs such as proto-oncogenes, anti-apoptotic genes and immune regulatory genes. Despite the low expression of TTP in various human cancers, the mechanism involving suppressed expression of TTP is not fully understood. Here, we demonstrate that Resveratrol (3,5,4'-trihydroxystilbene, Res), a naturally occurring compound, induces glioma cell apoptosis through activation of tristetraprolin (TTP). Res increased TTP expression in U87MG human glioma cells. Res-induced TTP destabilized the urokinase plasminogen activator and urokinase plasminogen activator receptor mRNAs by binding to the ARE regions containing the 3' untranslated regions of their mRNAs. Furthermore, TTP induced by Res suppressed cell growth and induced apoptosis in the human glioma cells. Because of its regulation of TTP expression, these findings suggest that the bioactive dietary compound Res can be used as a novel anti-cancer agent for the treatment of human malignant gliomas. PMID:26537190

  20. Programming Apoptosis and Autophagy with Novel Approaches for Diabetes Mellitus

    PubMed Central

    Maiese, Kenneth

    2015-01-01

    According to the World Health Organization, diabetes mellitus (DM) in the year 2030 will be ranked the seventh leading cause of death in the world. DM impacts all systems of the body with oxidant stress controlling cell fate through endoplasmic reticulum stress, mitochondrial dysfunction, alterations in uncoupling proteins, and the induction of apoptosis and autophagy. Multiple treatment approaches are being entertained for DM with Wnt1 inducible signaling pathway protein 1 (WISP1), mechanistic target of rapamycin (mTOR), and silent mating type information regulation 2 homolog) 1 (S. cerevisiae) (SIRT1) generating significant interest as target pathways that can address maintenance of glucose homeostasis as well as prevention of cellular pathology by controlling insulin resistance, stem cell proliferation, and the programmed cell death pathways of apoptosis and autophagy. WISP1, mTOR, and SIRT1 can rely upon similar pathways such as AMP activated protein kinase as well as govern cellular metabolism through cytokines such as EPO and oral hypoglycemics such as metformin. Yet, these pathways require precise biological control to exclude potentially detrimental clinical outcomes. Further elucidation of the ability to translate the roles of WISP1, mTOR, and SIRT1 into effective clinical avenues offers compelling prospects for new therapies against DM that can benefit hundreds of millions of individuals throughout the globe. PMID:25742566

  1. 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

  2. Structural studies of Bcl-2-family regulators of apoptosis

    SciTech Connect

    Stevens, P.W. |; Cai, X.; Schiffer, M.

    1996-06-01

    The Bcl-2 family of proteins includes about a dozen different proteins which share two small regions of amino acid homology but otherwise exhibit rather modest sequence similarities. The members of this family function as molecular regulators of apoptosis, some as accelerators of cell death and others as inhibitors of apoptosis. The authors analyzed the predicted secondary structures of Bcl-2-family proteins and found that a series of four amphipathic helices, three short {beta}-strands, and a carboxyl-terminal transmembrane helix were conserved throughout the family. Since the Bcl-2-family proteins do not have homology with any proteins of known three-dimensional structure, it seems likely that the tertiary structure assumed by these conserved Bcl-2-family structural elements will represent a completely new protein fold. The authors have prepared recombinant versions of particular proteins of the Bcl-2-family so that the can analyze their molecular structures experimentally. In addition, since some of the Bcl-2-family members homodimerize, they are using small-zone size-exclusion chromatography to analyze the homodimerization of individual, purified Bcl-2-family proteins in order to determine the association and rate constants for these dimerization reactions using computer-simulation methods previously developed in the group. Since certain of these proteins also interest with each other to form heterodimers, the authors also hope to extend the analyses to similarly analyze the heterodimerization of pairs of purified Bcl-2-family proteins.

  3. Resveratrol Induces Glioma Cell Apoptosis through Activation of Tristetraprolin

    PubMed Central

    Ryu, Jinhyun; Yoon, Nal Ae; Seong, Hyemin; Jeong, Joo Yeon; Kang, Seokmin; Park, Nammi; Choi, Jungil; Lee, Dong Hoon; Roh, Gu Seob; Kim, Hyun Joon; Cho, Gyeong Jae; Choi, Wan Sung; Park, Jae-Yong; Park, Jeong Woo; Kang, Sang Soo

    2015-01-01

    Tristetraprolin (TTP) is an AU-rich elements (AREs)-binding protein, which regulates the decay of AREs-containing mRNAs such as proto-oncogenes, anti-apoptotic genes and immune regulatory genes. Despite the low expression of TTP in various human cancers, the mechanism involving suppressed expression of TTP is not fully understood. Here, we demonstrate that Resveratrol (3,5,4?-trihydroxystilbene, Res), a naturally occurring compound, induces glioma cell apoptosis through activation of tristetraprolin (TTP). Res increased TTP expression in U87MG human glioma cells. Res-induced TTP destabilized the urokinase plasminogen activator and urokinase plasminogen activator receptor mRNAs by binding to the ARE regions containing the 3? untranslated regions of their mRNAs. Furthermore, TTP induced by Res suppressed cell growth and induced apoptosis in the human glioma cells. Because of its regulation of TTP expression, these findings suggest that the bioactive dietary compound Res can be used as a novel anti-cancer agent for the treatment of human malignant gliomas. PMID:26537190

  4. 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 ?M 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 ?g/mL, 20 ?g/mL and 50 ?g/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 ?g/mL mushroom lectin-treated hepatocytes. This finding may be of therapeutic benefit in people suffering from chronic arsenic exposure. PMID:20507870

  5. Apoptosis of non-parasitised red blood cells in Plasmodium yoelii malaria

    PubMed Central

    Totino, Paulo Renato Rivas; Pinna, Raquel Alves; De-Oliveira, Ana Cecilia Amado Xavier; Banic, Dalma Maria; Daniel-Ribeiro, Cláudio Tadeu; Ferreira-da-Cruz, Maria de Fátima

    2013-01-01

    Recently, while studying erythrocytic apoptosis during Plasmodium yoelii infection, we observed an increase in the levels of non-parasitised red blood cell (nRBC) apoptosis, which could be related to malarial anaemia. Therefore, in the present study, we attempted to investigate whether nRBC apoptosis is associated with the peripheral RBC count, parasite load or immune response. To this end, BALB/c mice were infected with P. yoelii 17XL and nRBC apoptosis, number of peripheral RBCs, parasitaemia and plasmatic levels of cytokines, nitric oxide and anti-RBC antibodies were evaluated at the early and late stages of anaemia. The apoptosis of nRBCs increased at the late stage and was associated with parasitaemia, but not with the intensity of the immune response. The increased percentage of nRBC apoptosis that was observed when anaemia was accentuated was not related to a reduction in peripheral RBCs. We conclude that nRBC apoptosis in P. yoelii malaria appears to be induced in response to a high parasite load. Further studies on malaria models in which acute anaemia develops during low parasitaemia are needed to identify the potential pathogenic role of nRBC apoptosis. PMID:24037189

  6. Inhibition of p53-induced apoptosis without affecting expression of p53-regulated genes

    E-print Network

    Domany, Eytan

    Inhibition of p53-induced apoptosis without affecting expression of p53-regulated genes Joseph apoptosis without gen- erally inhibiting gene expression regulated by p53 can facilitate tumor development Contributed by Leo Sachs, March 24, 2003 Using DNA microarray and clustering of expressed genes we have

  7. The Meaning of Death: Evolution and Ecology of Apoptosis in Protozoan Parasites

    E-print Network

    Gardner, Andy

    Review The Meaning of Death: Evolution and Ecology of Apoptosis in Protozoan Parasites Sarah E, United Kingdom Abstract: The discovery that an apoptosis-like, pro- grammed cell death (PCD) occurs their proliferation, not death. The prevailing, and untest- ed, opinion in the literature is that parasites employ

  8. CELLULAR METABOLISM AND APOPTOSIS DEXAMETHASONE, A PROMISING NEW CANDIDATE TO INTERVENE ON THE METABOLIC LEVEL

    E-print Network

    viability was quantified by MTT-assay. Apoptosis was assessed by quantification of nuclei showing chromatin. Biochemical assays: Apoptosis was induced by exposing cells to anti-Fas antibody (0.25µg/ml) for 6 hrs. Cell. Standard enzymatic assays were used for caspase-3 determination. Results : A) Analysis of 1 H-NMR spectra

  9. Calcineurin mediates acetylcholinesterase expression during calcium ionophore A23187-induced HeLa cell apoptosis

    E-print Network

    Tian, Weidong

    and promoter activity, in HeLa cells during apoptosis triggered by the calcium ionophore A23187 [9]. HoweverCalcineurin mediates acetylcholinesterase expression during calcium ionophore A23187-induced HeLa cell apoptosis Hui Zhu a , Wei Gao a , Hua Jiang a , Jun Wu a , Yu-fang Shi b , Xue-Jun Zhang a

  10. Regulation of Colonocyte Apoptosis by Bcl-2: Influence of Chemotherapeutic Dietary Agents 

    E-print Network

    Turk, Harmony

    2011-08-04

    . Apoptosis was measured using an enzyme-linked immunosorbent assay (ELISA), and western immunoblot was used to quantify bcl-2 levels. Apoptosis was significantly different (P<0.05) in DHA and butyrate treated cells depending on whether or not cultures were...

  11. AKT is translocated to the mitochondria during etoposide-induced apoptosis of HeLa cells.

    PubMed

    Park, Byoungduck; Je, Young-Tae; Chun, Kwang-Hoon

    2015-11-01

    Akt, or protein kinase B, is a key serine-threonine kinase, which exerts anti-apoptotic effects and promotes cell proliferation in response to various stimuli. Recently, however, it was demonstrated that Akt exhibits a proapoptotic role in certain contexts. During etoposide?induced apoptosis of HeLa cells, Akt enhances the interaction of second mitochondria?derived activator of caspases/direct IAP binding protein with low pI (Smac/DIABLO) and X?linked inhibitor of apoptosis protein by phosphorylating Smac at serine 67, and thus promotes apoptosis. However, the detailed mechanisms underlying Akt regulation in etoposide?mediated apoptosis remain to be determined. The present study investigated whether etoposide triggers the translocation of Akt into the mitochondria. It was found that Akt activity was increased and sustained during apoptosis triggered by etoposide in HeLa cells. During apoptosis, Akt was translocated from the cytoplasm into the mitochondria in a phosphoinositide 3?kinase-dependent manner at the early and late stages of apoptosis. Concomitantly, the depletion of Akt in the nuclear fraction was observed after etoposide treatment from analysis of confocal microscopy. The results suggest that etoposide?stimulated Akt is translocated into the mitochondria, thereby possibly enhancing its interaction with Smac and promoting apoptosis in HeLa cells. These results indicate that Akt may be a promising candidate for a pro-apoptotic approach in cancer treatment. PMID:26458825

  12. Involvement of Apoptosis in Host-Parasite Interactions in the Zebra Mussel

    PubMed Central

    Minguez, Laëtitia; Brulé, Nelly; Sohm, Bénédicte; Devin, Simon; Giambérini, Laure

    2013-01-01

    The question of whether cell death by apoptosis plays a biological function during infection is key to understanding host-parasite interactions. We investigated the involvement of apoptosis in several host-parasite systems, using zebra mussels Dreissena polymorpha as test organisms and their micro- and macroparasites. As a stress response associated with parasitism, heat shock proteins (Hsp) can be induced. In this protein family, Hsp70 are known to be apoptosis inhibitors. Mussels were diagnosed for their respective infections by standard histological methods; apoptosis was detected using the TUNEL methods on paraffin sections and Hsp70 by immunohistochemistry on cryosections. Circulating hemocytes were the main cells observed in apoptosis whereas infected tissues displayed no or few apoptotic cells. Parasitism by intracellular bacteria Rickettsiales-like and the trematode Bucephalus polymorphus were associated with the inhibition of apoptosis whereas ciliates Ophryoglena spp. or the trematode Phyllodistomum folium did not involve significant differences in apoptosis. Even if some parasites were able to modulate apoptosis in zebra mussels, we did not see evidence of any involvement of Hsp70 on this mechanism. PMID:23785455

  13. Possible mechanisms for the regulation of neutrophil apoptosis during allergic inflammation.

    PubMed

    Moiseeva, E G; Pasechnik, A V; Drozdova, G A; Frolov, V A

    2007-03-01

    The neutrophil-mediated inflammatory response is regulated via activation of the apoptosis program, which decreases the degree of tissue alteration. In rabbits with allergic inflammation a significant negative correlation was revealed between the intensity of neutrophil apoptosis and blood interferon-gamma concentration. PMID:18225748

  14. Induction of apoptosis by (-)-gossypol-enriched cottonseed oil in human breast cancer cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Induction of apoptosis is one of the mechanisms of chemotherapeutic agents against breast cancer. In addition, recent studies have shown that diets containing polyphenolic components possess anticancer activities either in vitro or in vivo by inhibiting cell proliferation and inducing apoptosis. T...

  15. Apoptosis: A Four-Week Laboratory Investigation for Advanced Molecular and Cellular Biology Students

    ERIC Educational Resources Information Center

    DiBartolomeis, Susan M.; Mone, James P.

    2003-01-01

    Over the past decade, apoptosis has emerged as an important field of study central to ongoing research in many diverse fields, from developmental biology to cancer research. Apoptosis proceeds by a highly coordinated series of events that includes enzyme activation, DNA fragmentation, and alterations in plasma membrane permeability. The detection…

  16. Tanshinone IIA blocks dexamethasone-induced apoptosis in osteoblasts through inhibiting Nox4-derived ROS production

    PubMed Central

    Li, Jia; He, Chongru; Tong, Wenwen; Zou, Yuming; Li, Dahe; Zhang, Chen; Xu, Weidong

    2015-01-01

    Apoptosis of osteoblasts caused by glucocorticoids has been identified as an important contributor to the development of osteoporosis. Tanshinone IIA (Tan), an active ingredient extracted from the rhizome of the Salvia miltiorrhiza Bunge (Danshen), has been reported to cast positive effects on osteoporosis. However, the precise mechanisms accounting this action remain elusive. In this study, by using osteoblastic MC3T3-E1 cells as a model, we confirmed the protective effects of Tan against dexamethasone (Dex)-induced cell apoptosis and further clarified its molecular mechanism of action. Our results showed that treatment with Dex caused cell injury, increased cytosol cytochrome c level and Nox expression, induced apoptosis in caspase-9-dependent manner, and enhanced reactive oxygen species (ROS) production. Tan attenuated these deleterious consequence triggered by Dex. Moreover, Dex-induced ROS production and cell injury were inhibited by antioxidant, NADPH oxidases inhibitors, Nox4 inhibitor, and Nox4 small interfering RNA (siRNA). Overexpression of Nox4 almost abolished the inhibitory effect of Tan on Dex-induced cell injury and apoptosis. The results also demonstrated significant involvement of Nox4 in the Dex-induced apoptosis. Nox4-derived ROS led to apoptosis through activation of intrinsic mitochondrial pathway. Additionally, we evidenced that Tan reversed Dex-induced apoptosis via inactivation of Nox4. The present findings suggest that inhibition of Nox4 may be a novel therapeutic approach of Tan to prevent against glucocorticoids-induced osteoblasts apoptosis and osteoporosis. PMID:26722597

  17. Metabolic memory in diabetes – from in vitro oddity to in vivo problem: Role of Apoptosis

    PubMed Central

    Kowluru, Renu A.; Chan, Pooi-See

    2011-01-01

    Retinal capillary cells undergo apoptosis before pathology characteristic of retinopathy can be observed, and the appearance of apoptotic capillary cell can predict the development of pathology. The purpose of this study is to investigate the effect of reversal of hyperglycemia on retinal capillary cell apoptosis, and identify the apoptosis encoding genes. Streptozotocin-diabetic rats were maintained either in poor glycemic control (PC, glycated hemoglobin, GHb >11%) or in good glycemic control (GC, GHb <6%) for 12 months, or allowed to be in PC for 6 months followed by GC for 6 additional months (PC–GC). Capillary cell apoptosis was determined in the trypsin-digested retinal microvasculature by TUNEL staining, and the genes encoding apoptosis were identified by Oligo GEArray rat apoptosis microarray that profiles 113 genes. Six months of good glycemic control that followed 6 months of poor control failed to attenuate the number of TUNEL-positive capillary cells in the retinal microvasculature. Twenty-three retinal genes, mainly from TNF ligand and receptor, caspase, Bcl-2 and death domain subfamilies that were upregulated by least a two-fold in PC rats remain upregulated after reversal of hyperglycemia. Thus, the continued activation of apoptosis plays a major role in the resistance of retinopathy to halt after re-institution of good glycemic control, and the regulation apoptosis machinery could help retard the progression of diabetic retinopathy. PMID:19463916

  18. Induction of apoptosis in HL-60 cells treated with medicinal herbs.

    PubMed

    Nishida, S; Kikuichi, S; Yoshioka, S; Tsubaki, M; Fujii, Y; Matsuda, H; Kubo, M; Irimajiri, K

    2003-01-01

    In order to develop a new apoptosis inducer, we screened 22 crude drugs for their apoptosis-inducing activity. It was found that Glycyrrhiza uralensis, Cynomorium songaricum, Eucommia ulmoides, Phellodendron amurense, Cinnamomum cassia and Paeonia lactiflora induced the death of HL-60 cells. To investigate the mechanism of apoptosis induced by these six crude drugs, the mitochondrial transmembrane potential and the activity of caspase-3 were measured. Reduced mitochondrial transmembrane potentials within 12 hours after the administration of Glycyrrhiza uralensis, Cynomorium songaricum, Phellodendron amurense and Paeonia lactiflora, and within 24 hours after the administration of Eucommia ulmoides and Cinnamomum cassia were observed. All of the six apoptosis-inducing crude drugs increased caspase-3 activity within 12-36 hours after administration. After further examining the apoptosis-inducing activity of berberine, palmatine, panelofuroline and glycyrrhizin, which were the ingredients obtained from Phellodendron amurense, Glycyrrhiza uralensis and Paeonia lactiflora, it was found that only berberine could induce apoptosis. From these results, it was concluded that the apoptosis induced by the six crude drugs (Glycyrrhiza uralensis, Cynomorium songaricum, Eucommia ulmoides, Phellodendron amurense, Cinnamomum cassia and Paeonia lactiflora) occurred via the mitochondrial route and that the apoptosis-conducting mechanism acted through a cascade involving caspase-3. PMID:14587878

  19. Non-genetic origins of cell-to-cell variability in TRAIL-induced apoptosis

    E-print Network

    examined apoptosis in HeLa cells and in non-transformed MCF10A mammary epithelial cells in the presenceLETTERS Non-genetic origins of cell-to-cell variability in TRAIL-induced apoptosis Sabrina L, noise in gene expression gives rise to cell-to- cell variability in protein concentrations1

  20. Mitochondrial complex I inhibitor rotenone induces apoptosis through enhancing mitochondrial reactive oxygen species production.

    PubMed

    Li, Nianyu; Ragheb, Kathy; Lawler, Gretchen; Sturgis, Jennie; Rajwa, Bartek; Melendez, J Andres; Robinson, J Paul

    2003-03-01

    Inhibition of mitochondrial respiratory chain complex I by rotenone had been found to induce cell death in a variety of cells. However, the mechanism is still elusive. Because reactive oxygen species (ROS) play an important role in apoptosis and inhibition of mitochondrial respiratory chain complex I by rotenone was thought to be able to elevate mitochondrial ROS production, we investigated the relationship between rotenone-induced apoptosis and mitochondrial reactive oxygen species. Rotenone was able to induce mitochondrial complex I substrate-supported mitochondrial ROS production both in isolated mitochondria from HL-60 cells as well as in cultured cells. Rotenone-induced apoptosis was confirmed by DNA fragmentation, cytochrome c release, and caspase 3 activity. A quantitative correlation between rotenone-induced apoptosis and rotenone-induced mitochondrial ROS production was identified. Rotenone-induced apoptosis was inhibited by treatment with antioxidants (glutathione, N-acetylcysteine, and vitamin C). The role of rotenone-induced mitochondrial ROS in apoptosis was also confirmed by the finding that HT1080 cells overexpressing magnesium superoxide dismutase were more resistant to rotenone-induced apoptosis than control cells. These results suggest that rotenone is able to induce apoptosis via enhancing the amount of mitochondrial reactive oxygen species production. PMID:12496265