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Sample records for prevents p53-mediated apoptosis

  1. Zbtb1 Safeguards Genome Integrity and Prevents p53-Mediated Apoptosis in Proliferating Lymphoid Progenitors.

    PubMed

    Cao, Xin; Lu, Ying; Zhang, Xianyu; Kovalovsky, Damian

    2016-08-15

    Expression of the transcription factor Zbtb1 is required for normal lymphoid development. We report in the present study that Zbtb1 maintains genome integrity in immune progenitors, without which cells undergo increased DNA damage and p53-mediated apoptosis during replication and differentiation. Increased DNA damage in Zbtb1-mutant (ScanT) progenitors was due to increased sensitivity to replication stress, which was a consequence of inefficient activation of the S-phase checkpoint response. Increased p53-mediated apoptosis affected not only lymphoid but also myeloid development in competitive bone marrow chimeras, and prevention of apoptosis by transgenic Bcl2 expression and p53 deficiency rescued lymphoid as well as myeloid development from Zbtb1-mutant progenitors. Interestingly, however, protection from apoptosis rescued only the early stages of T cell development, and thymocytes remained arrested at the double-negative 3 developmental stage, indicating a strict requirement of Zbtb1 at later T cell developmental stages. Collectively, these results indicate that Zbtb1 prevents DNA damage in replicating immune progenitors, allowing the generation of B cells, T cells, and myeloid cells. PMID:27402700

  2. Sodium orthovanadate inhibits p53-mediated apoptosis.

    PubMed

    Morita, Akinori; Yamamoto, Shinichi; Wang, Bing; Tanaka, Kaoru; Suzuki, Norio; Aoki, Shin; Ito, Azusa; Nanao, Tomohisa; Ohya, Soichiro; Yoshino, Minako; Zhu, Jin; Enomoto, Atsushi; Matsumoto, Yoshihisa; Funatsu, Osamu; Hosoi, Yoshio; Ikekita, Masahiko

    2010-01-01

    Sodium orthovanadate (vanadate) inhibits the DNA-binding activity of p53, but its precise effects on p53 function have not been examined. Here, we show that vanadate exerts a potent antiapoptotic activity through both transcription-dependent and transcription-independent mechanisms relative to other p53 inhibitors, including pifithrin (PFT) alpha. We compared the effects of vanadate to PFTalpha and PFTmicro, an inhibitor of transcription-independent apoptosis by p53. Vanadate suppressed p53-associated apoptotic events at the mitochondria, including the loss of mitochondrial membrane potential, the conformational change of Bax and Bak, the mitochondrial translocation of p53, and the interaction of p53 with Bcl-2. Similarly, vanadate suppressed the apoptosis-inducing activity of a mitochondrially targeted temperature-sensitive p53 in stable transfectants of SaOS-2 cells. In radioprotection assays, which rely on p53, vanadate completely protected mice from a sublethal dose of 8 Gy and partially from a lethal dose of 12 Gy. Together, our findings indicated that vanadate effectively suppresses p53-mediated apoptosis by both transcription-dependent and transcription-independent pathways, and suggested that both pathways must be inhibited to completely block p53-mediated apoptosis. PMID:20048077

  3. Modulation of p53-mediated transcriptional repression and apoptosis by the adenovirus E1B 19K protein.

    PubMed Central

    Sabbatini, P; Chiou, S K; Rao, L; White, E

    1995-01-01

    BRK cell lines that stably express adenovirus E1A and a murine temperature-sensitive p53 undergo apoptosis when p53 assumes the wild-type conformation. Expression of the E1B 19,000-molecular-weight (19K) protein rescues cells from this p53-mediated apoptosis and diverts cells to a growth-arrested state. As p53 likely functions as a tumor suppressor by regulating transcription, the ability of the E1B 19K protein to regulate p53-mediated transactivation and transcriptional repression was investigated. In promoter-reporter assays the E1B 19K did not block p53-mediated transactivation but did alleviate p53-mediated transcriptional repression. E1B 19K expression permitted efficient transcriptional activation of the p21/WAF-1/cip-1 mRNA by p53, consistent with maintenance of the growth arrest function of p53. The E1B 19K protein is thereby unique among DNA virus-transforming proteins that target p53 for inactivation in that it selectively modulates the transcriptional properties of p53. The E1B 19K protein also rescued cells from apoptosis induced by inhibitors of transcription and protein synthesis. This suggests that cell death may result from the inhibition of expression of survival factors which function to maintain cell viability. p53 may induce apoptosis through generalized transcriptional repression. In turn, the E1B 19K protein may prevent p53-mediated apoptosis by alleviating p53-mediated transcriptional repression. PMID:7823921

  4. 4-Hydroxynonenal induces p53-mediated apoptosis in retinal pigment epithelial cells

    PubMed Central

    Sharma, Abha; Sharma, Rajendra; Chaudhary, Pankaj; Vatsyayan, Rit; Pearce, Virginia; Jeyabal, Prince V.S.; Zimniak, Piotr; Awasthi, Sanjay; Awasthi, Yogesh C.

    2009-01-01

    4-Hydroxynonenal (4-HNE) has been suggested to be involved in stress-induced signaling for apoptosis. In present studies, we have examined the effects of 4-HNE on the intrinsic apoptotic pathway associated with p53 in human retinal pigment epithelial (RPE and ARPE-19) cells. Our results show that 4-HNE causes induction, phosphorylation, and nuclear accumulation of p53 which is accompanied with down regulation of MDM2, activation of the pro-apoptotic p53 target genes viz. p21 and Bax, JNK, caspase3, and onset of apoptosis in treated RPE cells. Reduced expression of p53 by an efficient silencing of the p53 gene resulted in a significant resistance of these cells to 4-HNE-induced cell death. The effects of 4-HNE on the expression and functions of p53 are blocked in GSTA4-4 over expressing cells indicating that 4-HNE-induced, p53-mediated signaling for apoptosis is regulated by GSTs. Our results also show that the induction of p53 in tissues of mGsta4 (-/-) mice correlate with elevated levels of 4-HNE due to its impaired metabolism. Together, these studies suggest that 4-HNE is involved in p53-mediated signaling in in vitro cell cultures as well as in vivo that can be regulated by GSTs. PMID:18930016

  5. Chk2 regulates transcription-independent p53-mediated apoptosis in response to DNA damage

    SciTech Connect

    Chen Chen; Shimizu, Shigeomi; Tsujimoto, Yoshihide; Motoyama, Noboru . E-mail: motoyama@nils.go.jp

    2005-07-29

    The tumor suppressor protein p53 plays a central role in the induction of apoptosis in response to genotoxic stress. The protein kinase Chk2 is an important regulator of p53 function in mammalian cells exposed to ionizing radiation (IR). Cells derived from Chk2-deficient mice are resistant to the induction of apoptosis by IR, and this resistance has been thought to be a result of the defective transcriptional activation of p53 target genes. It was recently shown, however, that p53 itself and histone H1.2 translocate to mitochondria and thereby induces apoptosis in a transcription-independent manner in response to IR. We have now examined whether Chk2 also regulates the transcription-independent induction of apoptosis by p53 and histone H1.2. The reduced ability of IR to induce p53 stabilization in Chk2-deficient thymocytes was associated with a marked impairment of p53 and histone H1 translocation to mitochondria. These results suggest that Chk2 regulates the transcription-independent mechanism of p53-mediated apoptosis by inducing stabilization of p53 in response to IR.

  6. Marijuana smoke condensate induces p53-mediated apoptosis in human lung epithelial cells.

    PubMed

    Kim, Ha Ryong; Jung, Mi Hyun; Lee, Soo Yeun; Oh, Seung Min; Chung, Kyu Hyuck

    2013-01-01

    Since the largely abused worldwide used of marijuana, there have been many ongoing debates regarding the adverse health effects of marijuana smoking. Marijuana smoking was recently proved to cause pulmonary toxicity by inducing genotoxic effects or generating reactive oxygen species. Because p53, a tumor suppressor gene, has an important pathophysiologic role in the regulation of lung epithelial cell DNA damage responses, we hypothesized that p53 may be involved in the oxidative stress-mediated apoptosis induced by marijuana smoking. First, we confirmed that marijuana smoke condensate (MSC) induces oxidative stress in BEAS-2B cells. We observed that reactive oxygen species (ROS) generation was increased by MSC in the DCFH-DA assay. Also, antioxidant enzyme (superoxide dismutase, catalase) activity and their mRNA expressions were up-regulated by MSC. Second, we investigated p53 involvement in the MSC-induced apoptotic pathway in BEAS-2B cells. The results showed that MSC increased caspase-3 activation and DNA fragmentation as markers of apoptosis. In addition, the mRNA levels of apoptosis-related genes (p53 and Bax) were increased by MSC and phospho-p53, along with the increase of Bax protein expression by MSC. Apoptosis and apoptosis-related gene expression were partially blocked by an inhibitor of p53-dependent transcriptional activation (pifithrin-α). The results indicate that p53 plays a role in MSC-induced apoptosis. Taken together, the findings of the present study suggest that MSC partially induces p53-mediated apoptosis through ROS generation in human lung epithelial cells and this may have broader implications for our understanding of pulmonary diseases. PMID:23665932

  7. HIF-1α antagonizes p53-mediated apoptosis by triggering HIPK2 degradation

    PubMed Central

    Nardinocchi, Lavinia; Puca, Rosa; D'Orazi, Gabriella

    2011-01-01

    Many human diseases are characterized by the development of tissue hypoxia. Hypoxia-inducible factor (HIF) is a transcription factor that regulates fundamental cellular processes in response to changes in oxygen concentration, such as angiogenesis, survival, and alterations in metabolism. The levels of HIF-1α subunit are increased in most solid tumors not only by low oxygen but also by growth factors and oncogenes and correlate with patient prognosis and treatment failure. The link between HIF-1α and apoptosis, a major determinant of cancer progression and treatment outcome, is poorly understood. Here we show that HIF-1α protects against drug-induced apoptosis by antagonizing the function of the tumor suppressor p53. HIF-1α upregulation induced proteasomal degradation of homeodomain-interacting protein kinase-2 (HIPK2), the p53 apoptotic activator. Inhibition of HIF-1α by siRNA, HIF-1α-dominant negative or by zinc re-established the HIPK2 levels and the p53-mediated chemosensitivity in tumor cells. Our findings identify a novel circuitry between HIF-1α and p53, and provide a paradigm for HIPK2 dictating cell response to antitumor therapies. PMID:21248371

  8. Structural proteins of Kaposi's sarcoma-associated herpesvirus antagonize p53-mediated apoptosis.

    PubMed

    Chudasama, P; Konrad, A; Jochmann, R; Lausen, B; Holz, P; Naschberger, E; Neipel, F; Britzen-Laurent, N; Stürzl, M

    2015-01-29

    The tumor suppressor p53 is a central regulatory molecule of apoptosis and is commonly mutated in tumors. Kaposi's sarcoma-associated herpesvirus (KSHV)-related malignancies express wild-type p53. Accordingly, KSHV encodes proteins that counteract the cell death-inducing effects of p53. Here, the effects of all KSHV genes on the p53 signaling pathway were systematically analyzed using the reversely transfected cell microarray technology. With this approach we detected eight KSHV-encoded genes with potent p53 inhibiting activity in addition to the previously described inhibitory effects of KSHV genes ORF50, K10 and K10.5. Interestingly, the three most potent newly identified inhibitors were KSHV structural proteins, namely ORF22 (glycoprotein H), ORF25 (major capsid protein) and ORF64 (tegument protein). Validation of these results with a classical transfection approach showed that these proteins inhibited p53 signaling in a dose-dependent manner and that this effect could be reversed by small interfering RNA-mediated knockdown of the respective viral gene. All three genes inhibited p53-mediated apoptosis in response to Nutlin-3 treatment in non-infected and KSHV-infected cells. Addressing putative mechanisms, we could show that these proteins could also inhibit the transactivation of the promoters of apoptotic mediators of p53 such as BAX and PIG3. Altogether, we demonstrate for the first time that structural proteins of KSHV can counteract p53-induced apoptosis. These proteins are expressed in the late lytic phase of the viral life cycle and are incorporated into the KSHV virion. Accordingly, these genes may inhibit cell death in the productive and in the early entrance phase of KSHV infection. PMID:24469037

  9. p53 Mediates Colistin-Induced Autophagy and Apoptosis in PC-12 Cells.

    PubMed

    Zhang, Ling; Xie, Daoyuan; Chen, Xueping; Hughes, Maria L R; Jiang, Guozheng; Lu, Ziyin; Xia, Chunli; Li, Li; Wang, Jinli; Xu, Wei; Sun, Yuan; Li, Rui; Wang, Rui; Qian, Feng; Li, Jian; Li, Jichang

    2016-09-01

    -induced autophagy and apoptosis are associated with the p53-mediated pathway. PMID:27324771

  10. Induction of p53-mediated transcription and apoptosis by exportin-1 (XPO1) inhibition in mantle cell lymphoma.

    PubMed

    Yoshimura, Mariko; Ishizawa, Jo; Ruvolo, Vivian; Dilip, Archana; Quintás-Cardama, Alfonso; McDonnell, Timothy J; Neelapu, Sattva S; Kwak, Larry W; Shacham, Sharon; Kauffman, Michael; Tabe, Yoko; Yokoo, Masako; Kimura, Shinya; Andreeff, Michael; Kojima, Kensuke

    2014-07-01

    The nuclear transporter exportin-1 (XPO1) is highly expressed in mantle cell lymphoma (MCL) cells, and is believed to be associated with the pathogenesis of this disease. XPO1-selective inhibitors of nuclear export (SINE) compounds have been shown to induce apoptosis in MCL cells. Given that p53 is a cargo protein of XPO1, we sought to determine the significance of p53 activation through XPO1 inhibition in SINE-induced apoptosis of MCL cells. We investigated the prognostic impact of XPO1 expression in MCL cells using Oncomine analysis. The significance of p53 mutational/functional status on sensitivity to XPO1 inhibition in cell models and primary MCL samples, and the functional role of p53-mediated apoptosis signaling, were also examined. Increased XPO1 expression was associated with poor prognosis in MCL patients. The XPO1 inhibitor KPT-185 induced apoptosis in MCL cells through p53-dependent and -independent mechanisms, and p53 status was a critical determinant of its apoptosis induction. The KPT-185-induced, p53-mediated apoptosis in the MCL cells occurred in a transcription-dependent manner. Exportin-1 appears to influence patient survival in MCL, and the SINE XPO1 antagonist KPT-185 effectively activates p53-mediated transcription and apoptosis, which would provide a novel strategy for the therapy of MCL. PMID:24766216

  11. Loss of p53-mediated cell-cycle arrest, senescence and apoptosis promotes genomic instability and premature aging

    PubMed Central

    Li, Tongyuan; Liu, Xiangyu; Jiang, Le; Manfredi, James; Zha, Shan; Gu, Wei

    2016-01-01

    Although p53-mediated cell cycle arrest, senescence and apoptosis are well accepted as major tumor suppression mechanisms, the loss of these functions does not directly lead to tumorigenesis, suggesting that the precise roles of these canonical activities of p53 need to be redefined. Here, we report that the cells derived from the mutant mice expressing p533KR, an acetylation-defective mutant that fails to induce cell-cycle arrest, senescence and apoptosis, exhibit high levels of aneuploidy upon DNA damage. Moreover, the embryonic lethality caused by the deficiency of XRCC4, a key DNA double strand break repair factor, can be fully rescued in the p533KR/3KR background. Notably, despite high levels of genomic instability, p533KR/3KRXRCC4−/− mice, unlike p53−/− XRCC4−/− mice, are not succumbed to pro-B-cell lymphomas. Nevertheless, p533KR/3KR XRCC4−/− mice display aging-like phenotypes including testicular atrophy, kyphosis, and premature death. Further analyses demonstrate that SLC7A11 is downregulated and that p53-mediated ferroptosis is significantly induced in spleens and testis of p533KR/3KRXRCC4−/− mice. These results demonstrate that the direct role of p53-mediated cell cycle arrest, senescence and apoptosis is to control genomic stability in vivo. Our study not only validates the importance of ferroptosis in p53-mediated tumor suppression in vivo but also reveals that the combination of genomic instability and activation of ferroptosis may promote aging-associated phenotypes. PMID:26943586

  12. p53 mediates cigarette smoke-induced apoptosis of pulmonary endothelial cells: inhibitory effects of macrophage migration inhibitor factor.

    PubMed

    Damico, Rachel; Simms, Tiffany; Kim, Bo S; Tekeste, Zenar; Amankwan, Henry; Damarla, Mahendra; Hassoun, Paul M

    2011-03-01

    Exposure to cigarette smoke (CS) is the most common cause of emphysema, a debilitating pulmonary disease histopathologically characterized by the irreversible destruction of lung architecture. Mounting evidence links enhanced endothelial apoptosis causally to the development of emphysema. However, the molecular determinants of human endothelial cell apoptosis and survival in response to CS are not fully defined. Such determinants could represent clinically relevant targets for intervention. We show here that CS extract (CSE) triggers the death of human pulmonary macrovascular endothelial cells (HPAECs) through a caspase 9-dependent apoptotic pathway. Exposure to CSE results in the increased expression of p53 in HPAECs. Using the p53 inhibitor, pifithrin-α (PFT-α), and RNA interference (RNAi) directed at p53, we demonstrate that p53 function and expression are required for CSE-mediated apoptosis. The expression of macrophage migration inhibitory factor (MIF), an antiapoptotic cytokine produced by HPAECs, also increases in response to CSE exposure. The addition of recombinant human MIF prevents cell death from exposure to CSE. Further, the suppression of MIF or its receptor/binding partner, Jun activation domain-binding protein 1 (Jab-1), with RNAi enhances the sensitivity of human pulmonary endothelial cells to CSE via a p53-dependent (PFT-α-inhibitable) pathway. Finally, we demonstrate that MIF is a negative regulator of p53 expression in response to CSE, placing MIF upstream of p53 as an antagonist of CSE-induced apoptosis. We conclude that MIF can protect human vascular endothelium from the toxic effects of CSE via the antagonism of p53-mediated apoptosis. PMID:20448056

  13. Benzo(a)pyrene Induced p53 Mediated Male Germ Cell Apoptosis: Synergistic Protective Effects of Curcumin and Resveratrol.

    PubMed

    Banerjee, Bhaswati; Chakraborty, Supriya; Ghosh, Debidas; Raha, Sanghamitra; Sen, Parimal C; Jana, Kuladip

    2016-01-01

    Benzo(a)pyrene (B(a)P) is an environmental toxicant that induces male germ cell apoptosis. Curcumin and resveratrol are phytochemicals with cytoprotective and anti-oxidative properties. At the same time resveratrol is also a natural Aryl hydrocarbon Receptor (AhR) antagonist. Our present study in isolated testicular germ cell population from adult male Wistar rats, highlighted the synergistic protective effect of curcumin and resveratrol against B(a)P induced p53 mediated germ cell apoptosis. Curcumin-resveratrol significantly prevented B(a)P induced decrease in sperm cell count and motility, as well as increased serum testosterone level. Curcumin-resveratrol co-treatment actively protected B(a)P induced testicular germ cell apoptosis. Curcumin-resveratrol co-treatment decreased the expression of pro-apoptotic proteins like cleaved caspase 3, 8 and 9, cleaved PARP, Apaf1, FasL, tBid. Curcumin-resveratrol co-treatment decreased Bax/Bcl2 ratio, mitochondria to cytosolic translocation of cytochrome c and activated the survival protein Akt. Curcumin-resveratrol decreased the expression of p53 dependent apoptotic genes like Fas, FasL, Bax, Bcl2, and Apaf1. B(a)P induced testicular reactive oxygen species (ROS) generation and oxidative stress were significantly ameliorated with curcumin and resveratrol. Curcumin-resveratrol co-treatment prevented B(a)P induced nuclear translocation of AhR and CYP1A1 (Cytochrome P4501A1) expression. The combinatorial treatment significantly inhibited B(a)P induced ERK 1/2, p38 MAPK and JNK 1/2 activation. B(a)P treatment increased the expression of p53 and its phosphorylation (p53 ser 15). Curcumin-resveratrol co-treatment significantly decreased p53 level and its phosphorylation (p53 ser 15). The study concludes that curcumin-resveratrol synergistically modulated MAPKs and p53, prevented oxidative stress, regulated the expression of pro and anti-apoptotic proteins as well as the proteins involved in B(a)P metabolism thus protected germ

  14. Benzo(a)pyrene Induced p53 Mediated Male Germ Cell Apoptosis: Synergistic Protective Effects of Curcumin and Resveratrol

    PubMed Central

    Banerjee, Bhaswati; Chakraborty, Supriya; Ghosh, Debidas; Raha, Sanghamitra; Sen, Parimal C.; Jana, Kuladip

    2016-01-01

    Benzo(a)pyrene (B(a)P) is an environmental toxicant that induces male germ cell apoptosis. Curcumin and resveratrol are phytochemicals with cytoprotective and anti-oxidative properties. At the same time resveratrol is also a natural Aryl hydrocarbon Receptor (AhR) antagonist. Our present study in isolated testicular germ cell population from adult male Wistar rats, highlighted the synergistic protective effect of curcumin and resveratrol against B(a)P induced p53 mediated germ cell apoptosis. Curcumin-resveratrol significantly prevented B(a)P induced decrease in sperm cell count and motility, as well as increased serum testosterone level. Curcumin-resveratrol co-treatment actively protected B(a)P induced testicular germ cell apoptosis. Curcumin-resveratrol co-treatment decreased the expression of pro-apoptotic proteins like cleaved caspase 3, 8 and 9, cleaved PARP, Apaf1, FasL, tBid. Curcumin-resveratrol co-treatment decreased Bax/Bcl2 ratio, mitochondria to cytosolic translocation of cytochrome c and activated the survival protein Akt. Curcumin-resveratrol decreased the expression of p53 dependent apoptotic genes like Fas, FasL, Bax, Bcl2, and Apaf1. B(a)P induced testicular reactive oxygen species (ROS) generation and oxidative stress were significantly ameliorated with curcumin and resveratrol. Curcumin-resveratrol co-treatment prevented B(a)P induced nuclear translocation of AhR and CYP1A1 (Cytochrome P4501A1) expression. The combinatorial treatment significantly inhibited B(a)P induced ERK 1/2, p38 MAPK and JNK 1/2 activation. B(a)P treatment increased the expression of p53 and its phosphorylation (p53 ser 15). Curcumin-resveratrol co-treatment significantly decreased p53 level and its phosphorylation (p53 ser 15). The study concludes that curcumin-resveratrol synergistically modulated MAPKs and p53, prevented oxidative stress, regulated the expression of pro and anti-apoptotic proteins as well as the proteins involved in B(a)P metabolism thus protected germ

  15. ARF and ATM/ATR cooperate in p53-mediated apoptosis upon oncogenic stress

    SciTech Connect

    Pauklin, Siim . E-mail: spauklin@ut.ee; Kristjuhan, Arnold; Maimets, Toivo; Jaks, Viljar

    2005-08-26

    Induction of apoptosis is pivotal for eliminating cells with damaged DNA or deregulated proliferation. We show that tumor suppressor ARF and ATM/ATR kinase pathways cooperate in the induction of apoptosis in response to elevated expression of c-myc, {beta}-catenin or human papilloma virus E7 oncogenes. Overexpression of oncogenes leads to the formation of phosphorylated H2AX foci, induction of Rad51 protein levels and ATM/ATR-dependent phosphorylation of p53. Inhibition of ATM/ATR kinases abolishes both induction of Rad51 and phosphorylation of p53, and remarkably reduces the level of apoptosis induced by co-expression of oncogenes and ARF. However, the induction of apoptosis is downregulated in p53-/- cells and does not depend on activities of ATM/ATR kinases, indicating that efficient induction of apoptosis by oncogene activation depends on coordinated action of ARF and ATM/ATR pathways in the regulation of p53.

  16. Anticancer Activity of γ-Bisabolene in Human Neuroblastoma Cells via Induction of p53-Mediated Mitochondrial Apoptosis.

    PubMed

    Jou, Yu-Jen; Hua, Chun-Hung; Lin, Chen-Sheng; Wang, Ching-Ying; Wan, Lei; Lin, Ying-Ju; Huang, Su-Hua; Lin, Cheng-Wen

    2016-01-01

    γ-Bisabolene has demonstrated antiproliferative activities against several human cancer cell lines. This study first discloses the antiproliferative and apoptosis induction activities of γ-bisabolene to human neuroblastoma TE671 cells. A CC50 value of γ-bisabolene was 8.2 μM to TE671 cells. Cell cycle analysis with PI staining showed γ-bisabolene elevating the sub-G1 fractions in a time-dependent manner. In addition, annexin V-FITC/PI staining showed γ-bisabolene significantly triggering early (annexin-V positive/PI negative) and late (annexin-V positive/PI positive) apoptosis in dose-dependent manners. γ-Bisabolene induced caspase 3/8/9 activation, intracellular ROS increase, and mitochondrial membrane potential decrease in apoptosis of human neuro-blastoma cells. Moreover, γ-bisabolene increased p53 phosphorylation and up-regulated p53-mediated apoptotic genes Bim and PUMA, as well as decreased the mRNA and protein levels of CK2α. Notably, the results indicated the involvement of CK2α-p53 pathways in mitochondria-mediated apoptosis of human neuroblastoma cells treated with γ-bisabolene. This study elucidated the apoptosis induction pathways of γ-bisabolene-treated neuroblastoma cells, in which could be useful for developing anti-neuroblastoma drugs. PMID:27164076

  17. p53 mediated apoptosis in osteosarcoma MG-63 cells by inhibition of FANCD2 gene expression

    PubMed Central

    Xia, Peng; Sun, Yifu; Zheng, Changjun; Hou, Tingting; Kang, Mingyang; Yang, Xiaoyu

    2015-01-01

    Purpose: The aim of this study was to investigate the association between osteosarcoma (OS) and Fanconi anemia (FA) related pathways and the molecular mechanisms. Methods: siRNA for Fanconi anemia complementation group D2 (FANCD2) was constructed and transfected into the osteosarcoma cell line MG-63 cells. Expression of TP53INP1, p53, p21, caspase-9, and caspase-3 mRNA in MG-63 cells were examined by real-time fluorescence quantitative PCR, and the protein levels were also determined by western blot. Results: After silence of the FANCD2 gene in MG-63 cells, cell proliferation was inhibited, cell cycle was arrested and cell apoptosis was induced. The apoptosis was mediated by the p53 signaling pathway. After FANCD2 expression was inhibited, TP53INP1 gene expression was up-regulated, phosphorylation of p53 was promoted and the p21 protein was activated, leading to cell cycle arrested in G1, finally resulted in caspase-dependent cell apoptosis. Conclusions: Inhibition of FANCD2 gene expression can induce apoptosis of osteosarcoma cells, which indicated that FANCD2 played an important role in the development of osteosarcoma and it might be a potential target for treatment of osteosarcoma. PMID:26379910

  18. A novel TRIM family member, Trim69, regulates zebrafish development through p53-mediated apoptosis.

    PubMed

    Han, Ruiqin; Zhao, Qing; Zong, Shudong; Miao, Shiying; Song, Wei; Wang, Linfang

    2016-05-01

    Trim69 contains the hallmark domains of a tripartite motif (TRIM) protein, including a Ring-finger domain, B-box domain, and coiled-coil domain. Trim69 is structurally and evolutionarily conserved in zebrafish, mouse, rat, human, and chimpanzee. The role of this protein is unclear, however, so we investigated its function in zebrafish development. Trim69 is extensively expressed in zebrafish adults and developing embryos-particularly in the testis, brain, ovary, and heart-and its expression decreases in a time- and stage-dependent manner. Loss of trim69 in zebrafish induces apoptosis and activates apoptosis-related processes; indeed, the tp53 pathway was up-regulated in response to the knockdown. Expression of human trim69 rescued the apoptotic phenotype, while overexpression of trim69 does not increase cellular apoptosis. Taken together, our results suggest that trim69 participates in tp53-mediated apoptosis during zebrafish development. Mol. Reprod. Dev. 83: 442-454, 2016. © 2016 Wiley Periodicals, Inc. PMID:27031046

  19. Targeting GRP75 Improves HSP90 Inhibitor Efficacy by Enhancing p53-Mediated Apoptosis in Hepatocellular Carcinoma

    PubMed Central

    Yang, Ling; Liu, Xiaoyu; E, Qiukai; Gao, Peiye; Ye, Xiaofei; Liu, Wen; Zuo, Ji

    2014-01-01

    Heat shock protein 90 (HSP90) inhibitors are potential drugs for cancer therapy. The inhibition of HSP90 on cancer cell growth largely through degrading client proteins, like Akt and p53, therefore, triggering cancer cell apoptosis. Here, we show that the HSP90 inhibitor 17-AAG can induce the expression of GRP75, a member of heat shock protein 70 (HSP70) family, which, in turn, attenuates the anti-growth effect of HSP90 inhibition on cancer cells. Additionally, 17-AAG enhanced binding of GRP75 and p53, resulting in the retention of p53 in the cytoplasm. Blocking GRP75 with its inhibitor MKT-077 potentiated the anti-tumor effects of 17-AAG by disrupting the formation of GRP75-p53 complexes, thereby facilitating translocation of p53 into the nuclei and leading to the induction of apoptosis-related genes. Finally, dual inhibition of HSP90 and GRP75 was found to significantly inhibit tumor growth in a liver cancer xenograft model. In conclusion, the GRP75 inhibitor MKT-077 enhances 17-AAG-induced apoptosis in HCCs and increases p53-mediated inhibition of tumor growth in vivo. Dual targeting of GRP75 and HSP90 may be a useful strategy for the treatment of HCCs. PMID:24465691

  20. Integrated high-throughput analysis identifies Sp1 as a crucial determinant of p53-mediated apoptosis

    PubMed Central

    Li, H; Zhang, Y; Ströse, A; Tedesco, D; Gurova, K; Selivanova, G

    2014-01-01

    The restoration of p53 tumor suppressor function is a promising therapeutic strategy to combat cancer. However, the biological outcomes of p53 activation, ranging from the promotion of growth arrest to the induction of cell death, are hard to predict, which limits the clinical application of p53-based therapies. In the present study, we performed an integrated analysis of genome-wide short hairpin RNA screen and gene expression data and uncovered a previously unrecognized role of Sp1 as a central modulator of the transcriptional response induced by p53 that leads to robust induction of apoptosis. Sp1 is indispensable for the pro-apoptotic transcriptional repression by p53, but not for the induction of pro-apoptotic genes. Furthermore, the p53-dependent pro-apoptotic transcriptional repression required the co-binding of Sp1 to p53 target genes. Our results also highlight that Sp1 shares with p53 a common regulator, MDM2, which targets Sp1 for proteasomal degradation. This uncovers a new mechanism of the tight control of apoptosis in cells. Our study advances the understanding of the molecular basis of p53-mediated apoptosis and implicates Sp1 as one of its key modulators. We found that small molecules reactivating p53 can differentially modulate Sp1, thus providing insights into how to manipulate p53 response in a controlled way. PMID:24971482

  1. Revisiting DNA damage repair, p53-mediated apoptosis and cisplatin sensitivity in germ cell tumors.

    PubMed

    Cavallo, Francesca; Feldman, Darren R; Barchi, Marco

    2013-01-01

    Testicular germ cell tumors (TGCTs), ie, seminomas and nonseminomas, account for 1% to 3% of all neoplasms in men. They are the most common cancer in young white males and are unique in their responsiveness to cisplatin-based chemotherapy. For this reason, TGCTs are considered a model for curative disease. However, up to now, the molecular mechanisms behind this exceptional responsiveness to DNA-damaging agents have remained unclear. A hypersensitive apoptotic response, as well as a reduction in the proficiency to repair cisplatin-induced DNA damage might account for this behavior. In this review, building on recent findings of p53-induced apoptosis and DNA-repair mechanisms in TGCTs, we will discuss the molecular bases that drive tumor sensitivity to cisplatin, emphasizing the new therapeutic approaches proposed to eventually constrain tumor recurrence, and target TGCTs which are unresponsive to standard therapies. PMID:23784838

  2. NSC-87877 inhibits DUSP26 function in neuroblastoma resulting in p53-mediated apoptosis

    PubMed Central

    Shi, Y; Ma, I T; Patel, R H; Shang, X; Chen, Z; Zhao, Y; Cheng, J; Fan, Y; Rojas, Y; Barbieri, E; Chen, Z; Yu, Y; Jin, J; Kim, E S; Shohet, J M; Vasudevan, S A; Yang, J

    2015-01-01

    Dual specificity protein phosphatase 26 (DUSP26) is overexpressed in high-risk neuroblastoma (NB) and contributes to chemoresistance by inhibiting p53 function. In vitro, DUSP26 has also been shown to effectively inhibit p38 MAP kinase. We hypothesize that inhibiting DUSP26 will result in decreased NB cell growth in a p53 and/or p38-mediated manner. NSC-87877 (8-hydroxy-7-[(6-sulfo-2-naphthyl)azo]-5-quinolinesulfonic acid), a novel DUSP26 small molecule inhibitor, shows effective growth inhibition and induction of apoptosis in NB cell lines. NB cell lines treated with small hairpin RNA (shRNA) targeting DUSP26 also exhibit a proliferation defect both in vitro and in vivo. Treatment of NB cell lines with NSC-87877 results in increased p53 phosphorylation (Ser37 and Ser46) and activation, increased activation of downstream p38 effector proteins (heat shock protein 27 (HSP27) and MAP kinase-activated protein kinase 2 (MAPKAPK2)) and poly ADP ribose polymerase/caspase-3 cleavage. The cytotoxicity resulting from DUSP26 inhibition is partially reversed by knocking down p53 expression with shRNA and also by inhibiting p38 activity with SB203580 (4-[4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-1H-imidazol-5-yl]pyridine). In an intrarenal mouse model of NB, NSC-87877 treatment results in decreased tumor growth and increased p53 and p38 activity. Together, these results suggest that DUSP26 inhibition with NSC-87877 is an effective strategy to induce NB cell cytotoxicity in vitro and in vivo through activation of the p53 and p38 mitogen-activated protein kinase (MAPK) tumor-suppressor pathways. PMID:26247726

  3. Aneuploidy generates proteotoxic stress and DNA damage concurrently with p53-mediated post-mitotic apoptosis in SAC-impaired cells.

    PubMed

    Ohashi, Akihiro; Ohori, Momoko; Iwai, Kenichi; Nakayama, Yusuke; Nambu, Tadahiro; Morishita, Daisuke; Kawamoto, Tomohiro; Miyamoto, Maki; Hirayama, Takaharu; Okaniwa, Masanori; Banno, Hiroshi; Ishikawa, Tomoyasu; Kandori, Hitoshi; Iwata, Kentaro

    2015-01-01

    The molecular mechanism responsible that determines cell fate after mitotic slippage is unclear. Here we investigate the post-mitotic effects of different mitotic aberrations--misaligned chromosomes produced by CENP-E inhibition and monopolar spindles resulting from Eg5 inhibition. Eg5 inhibition in cells with an impaired spindle assembly checkpoint (SAC) induces polyploidy through cytokinesis failure without a strong anti-proliferative effect. In contrast, CENP-E inhibition causes p53-mediated post-mitotic apoptosis triggered by chromosome missegregation. Pharmacological studies reveal that aneuploidy caused by the CENP-E inhibitor, Compound-A, in SAC-attenuated cells causes substantial proteotoxic stress and DNA damage. Polyploidy caused by the Eg5 inhibitor does not produce this effect. Furthermore, p53-mediated post-mitotic apoptosis is accompanied by aneuploidy-associated DNA damage response and unfolded protein response activation. Because Compound-A causes p53 accumulation and antitumour activity in an SAC-impaired xenograft model, CENP-E inhibitors could be potential anticancer drugs effective against SAC-impaired tumours. PMID:26144554

  4. Kaempferol induces ATM/p53-mediated death receptor and mitochondrial apoptosis in human umbilical vein endothelial cells.

    PubMed

    Lee, Chiu-Fang; Yang, Jai-Sing; Tsai, Fuu-Jen; Chiang, Ni-Na; Lu, Chi-Cheng; Huang, Yu-Syuan; Chen, Chun; Chen, Fu-An

    2016-05-01

    Kaempferol is a member of the flavonoid compounds found in vegetables and fruits. It is shown to exhibit biological impact and anticancer activity, but no report exists on the angiogenic effect of kaempferol and induction of cell apoptosis in vitro. In this study, we investigated the role of kaempferol on anti-angiogenic property and the apoptotic mechanism of human umbilical vein endothelial cells (HUVECs). Our results demonstrated that kaempferol decreased HUVEC viability in a time- and concentration-dependent manner. Kaempferol also induced morphological changes and sub-G1 phase cell population (apoptotic cells). Kaempferol triggered apoptosis of HUVECs as detecting by DNA fragmentation, comet assay and immunofluorescent staining for activated caspase-3. The caspase signals, including caspase-8, -9 and -3, were time-dependently activated in HUVECs after kaempferol exposure. Furthermore, pre-treatment with a specific inhibitor of caspase-8 (Z-IETD-FMK) significantly reduced the activity of caspase-8, -9 and -3, indicating that extrinsic pathway is a major signaling pathway in kaempferol-treated HUVECs. Importantly, kaempferol promoted reactive oxygen species (ROS) evaluated using flow cytometric assay in HUVECs. We further investigated the upstream extrinsic pathway and showed that kaempferol stimulated death receptor signals [Fas/CD95, death receptor 4 (DR4) and DR5] through increasing the levels of phosphorylated p53 and phosphorylated ATM pathways in HUVECs, which can be individually confirmed by N-acetylcysteine (NAC), ATM specific inhibitor (caffeine) and p53 siRNA. Based on these results, kaempferol-induced HUVEC apoptosis was involved in an ROS-mediated p53/ATM/death receptor signaling. Kaempferol might possess therapeutic effects on cancer treatment in anti-vascular targeting. PMID:26984266

  5. Berberine induces mitochondrial apoptosis of EBV-transformed B cells through p53-mediated regulation of XAF1 and GADD45α.

    PubMed

    Park, Ga Bin; Park, Sang Hyun; Kim, Daejin; Kim, Yeong Seok; Yoon, Sung Ho; Hur, Dae Young

    2016-07-01

    Berberine exhibits antiproliferative or cytotoxic effects against various cancers. ROS and wild-type p53 play a critical role in berberine-induced cytotoxic effects. In this study, we investigated the correlation between XAF1 and functional p53 in EBV-transformed B cells or cancerous B cells after treatment with berberine. Berberine decreased cell viability and induced apoptosis through a mitochondria-dependent pathway in EBV-transformed B cells and cancerous B cells, but not in normal peripheral blood mononuclear cells. Activated p53 and its downstream targets XAF1 and GADD45α interacted with PUMA, Bax, and Bim in mitochondria after treatment with berberine. Blocking phosphorylation of p38/JNK MAPK and treatment with PFT-α, a selective p53 inhibitor, effectively prevented apoptosis and the upregulation of phosphorylated p53, XAF1, and GADD45α. NAC, a ROS scavenger, also suppressed berberine-induced mitochondria disruption and the whole apoptotic process via restoration of p53-related proteins and proapoptotic Bcl-2 family proteins. Taken together, our results suggest that ROS generation might be a predisposing event in berberine-induced mitochondrial apoptosis in EBV-transformed B cells through the upregulation of XAF1 and GADD45α expression by MAPK and functional p53. PMID:27121748

  6. Activation of p53 mediated glycolytic inhibition-oxidative stress-apoptosis pathway in Dalton's lymphoma by a ruthenium (II)-complex containing 4-carboxy N-ethylbenzamide.

    PubMed

    Koiri, Raj Kumar; Trigun, Surendra Kumar; Mishra, Lallan

    2015-03-01

    There is a general agreement that most of the cancer cells switch over to aerobic glycolysis (Warburg effect) and upregulate antioxidant enzymes to prevent oxidative stress induced apoptosis. Thus, there is an evolving view to target these metabolic alterations by novel anticancer agents to restrict tumor progression in vivo. Previously we have reported that when a non toxic dose (10 mg/kg bw i.p.) of a novel anticancer ruthenium(II)-complex containing 4-carboxy N-ethylbenzamide; Ru(II)-CNEB, was administered to the Dalton's lymphoma (DL) bearing mice, it regressed DL growth by inducing apoptosis in the DL cells. It also inactivated M4-LDH (M4-lactate dehydrogenase), an enzyme that drives anaerobic glycolysis in the tumor cells. In the present study we have investigated whether this compound is able to modulate regulation of glycolytic inhibition-apoptosis pathway in the DL cells in vivo. We observed that Ru(II)-CNEB could decline expression of the inducible form of 6-phosphofructo-2-kinase (iPFK2: PFKFB3), the master regulator of glycolysis in the DL cells. The complex also activated superoxide dismutase (the H2O2 producing enzyme) but declined the levels of catalase and glutathione peroxidase (the two H2O2 degrading enzymes) to impose oxidative stress in the DL cells. This was consistent with the enhanced p53 level, decline in Bcl2/Bax ratio and activation of caspase 9 in those DL cells. The findings suggest that Ru(II)-CNEB is able to activate oxidative stress-apoptosis pathway via p53 (a tumor supressor protein) mediated repression of iPFK2, a key glycolytic regulator, in the DL cells in vivo. PMID:25576833

  7. The MEK/ERK Pathway is the Primary Conduit for Borrelia burgdorferi-Induced Inflammation and P53-Mediated Apoptosis in Oligodendrocytes

    PubMed Central

    Parthasarathy, Geetha; Philipp, Mario T.

    2013-01-01

    Lyme neuroborreliosis (LNB) affects both the central and peripheral nervous systems. In a rhesus macaque model of LNB we had previously shown that brains of rhesus macaques inoculated with Borrelia burgdorferi release inflammatory mediators, and undergo oligodendrocyte and neuronal cell death. In vitro analysis of this phenomenon indicated that while B. burgdorferi can induce inflammation and apoptosis of oligodendrocytes per se, microglia are required for neuronal apoptosis. We hypothesized that the inflammatory milieu elicited by the bacterium in microglia or oligodendrocytes contributes to the apoptosis of neurons and glial cells, respectively, and that downstream signaling events in NFkB and/or MAPK pathways play a role in these phenotypes. To test these hypotheses in oligodendrocytes, several pathway inhibitors were used to determine their effect on inflammation and apoptosis, as induced by B. burgdorferi. In a human oligodendrocyte cell line (MO3.13), inhibition of the ERK pathway in the presence of B. burgdorferi markedly reduced inflammation, followed by the JNK, p38 and NFkB pathway inhibition. In addition to eliciting inflammation, B. burgdorferi also increased total p53 protein levels, and suppression of the ERK pathway mitigated this effect. While inhibition of p53 had a minimal effect in reducing inflammation, suppression of the ERK pathway or p53 reduced apoptosis as measured by active caspase-3 activity and the TUNEL assay. A similar result was seen in primary human oligodendrocytes wherein suppression of ERK or p53 reduced apoptosis. It is possible that inflammation and apoptosis in oligodendrocytes are divergent arms of MAPK pathways, particularly the MEK/ERK pathway. PMID:24114360

  8. Quantitative phosphoproteomic analysis reveals γ-bisabolene inducing p53-mediated apoptosis of human oral squamous cell carcinoma via HDAC2 inhibition and ERK1/2 activation.

    PubMed

    Jou, Yu-Jen; Chen, Chao-Jung; Liu, Yu-Ching; Way, Tzong-Der; Lai, Chih-Ho; Hua, Chun-Hung; Wang, Ching-Ying; Huang, Su-Hua; Kao, Jung-Yie; Lin, Cheng-Wen

    2015-10-01

    γ-Bisabolene, one of main components in cardamom, showed potent in vitro and in vivo anti-proliferative activities against human oral squamous cell carcinoma (OSCC). γ-Bisabolene activated caspases-3/9 and decreased mitochondrial memebrane potential, leading to apoptosis of OSCC cell lines (Ca9-22 and SAS), but not normal oral fibroblast cells. Phosphoproteome profiling of OSCC cells treated with γ-bisabolene was identified using TiO2-PDMS plate and LC-MS/MS, then confirmed using Western blotting and real-time RT-PCR assays. Phosphoproteome profiling revealed that γ-bisabolene increased the phosphorylation of ERK1/2, protein phosphatases 1 (PP1), and p53, as well as decreased the phosphorylation of histone deacetylase 2 (HDAC2) in the process of apoptosis induction. Protein-protein interaction network analysis proposed the involvement of PP1-HDAC2-p53 and ERK1/2-p53 pathways in γ-bisabolene-induced apoptosis. Subsequent assays indicated γ-bisabolene eliciting p53 acetylation that enhanced the expression of p53-regulated apoptotic genes. PP1 inhibitor-2 restored the status of HDAC2 phosphorylation, reducing p53 acetylation and PUMA mRNA expression in γ-bisabolene-treated Ca9-22 and SAS cells. Meanwhile, MEK and ERK inhibitors significantly decreased γ-bisabolene-induced PUMA expression in both cancer cell lines. Notably, the results ascertained the involvement of PP1-HDAC2-p53 and ERK1/2-p53 pathways in mitochondria-mediated apoptosis of γ-bisabolene-treated cells. This study demonstrated γ-bisabolene displaying potent anti-proliferative and apoptosis-inducing activities against OSCC in vitro and in vivo, elucidating molecular mechanisms of γ-bisabolene-induced apoptosis. The novel insight could be useful for developing anti-cancer drugs. PMID:26194454

  9. Induction of p53-mediated apoptosis in splenocytes and thymocytes of C57BL/6 mice exposed to perfluorooctane sulfonate (PFOS)

    SciTech Connect

    Dong, Guang-Hui; Wang, Jing; Zhang, Ying-Hua; Liu, Miao-Miao; Wang, Da; Zheng, Li; Jin, Yi-He

    2012-10-15

    Perfluorooctane sulfonate (PFOS) is a persistent environmental contaminant found in human and wildlife tissues. It has been reported that PFOS can cause atrophy of the immune organs and apoptosis of immunocytes in rodents. However, the mechanism behind such cause is still unclear. To understand the model of cell death and its mechanism on lymphoid cells in vivo, we conducted a dose/response experiment in which 4 groups of male adult C57BL/6 mice (12 mice per group) were dosed daily by oral gavage with PFOS at 0, 0.0167, 0.0833, or 0.8333 mg/kg/day, yielding targeted Total Administered Dose (TAD) of 0, 1, 5, or 50 mg PFOS/kg, respectively, over 60 days. The results showed that spleen and thymus weight were significantly reduced in the highest PFOS-dose-group (TAD 50 mg PFOS/kg) compared to the control group, whereas liver weight was significantly increased. We analyzed the cell death via apoptosis with an annexin-V/propidium iodide assay by flow cytometry, and observed that both the percentage of apoptosis and the expression of the pro-apoptotic proteins p53 in splenocytes and thymocytes increased in a dose-related manner after PFOS treatment. We also observed that PFOS induced p53-dependent apoptosis through the cooperation between the Bcl-xl down regulation without changing the Bcl-2 and Bax expression. The down regulation of Bcl-xl was strongly indicating mitochondrial involvement in apoptosis. It is confirmed by the release of cytochrome c and activation of caspase-3. All of these findings establish an important role of p53 and mitochondrial function in PFOS induced toxic environment in the host. -- Highlights: ► PFOS immunotoxicity is caused by induction of apoptosis via the p53 activation. ► PFOS exposure can induce down regulation of Bcl-xl. ► Mitochondria are involved in PFOS-induced apoptosis. ► PFOS exposure can cause the release of cytochrome c and activation of caspase-3.

  10. Triptolide sensitizes AML cells to TRAIL-induced apoptosis via decrease of XIAP and p53-mediated increase of DR5.

    PubMed

    Carter, Bing Z; Mak, Duncan H; Schober, Wendy D; Dietrich, Martin F; Pinilla, Clemencia; Vassilev, Lyubomir T; Reed, John C; Andreeff, Michael

    2008-04-01

    Acute myeloid leukemia (AML) cells are relatively resistant to tumor necrosis factor alpha-related apoptosis-inducing ligand (TRAIL). We previously reported that triptolide, a potent anticancer agent from a Chinese herb, decreases XIAP in leukemic cells. We evaluated the combination of triptolide and TRAIL and found synergistic promotion of apoptosis in AML cells. XIAP-overexpressing U937 cells (U937XIAP) were more resistant to TRAIL than U937neo cells, and inhibition of XIAP with the small-molecule inhibitor 1396-11 enhanced TRAIL-induced apoptosis, implying XIAP as a resistance factor in AML. Furthermore, triptolide increased DR5 levels in OCI-AML3, while the DR5 increase was blunted in p53-knockdown OCI-AML3 and p53-mutated U937 cells, confirming a role for p53 in the regulation of DR5. In support of this finding, disruption of MDM2-p53 binding with subsequent increase in p53 levels by nutlin3a increased DR5 levels and sensitized OCI-AML3 cells to TRAIL. The combination of 1396-11 plus nutlin3a plus TRAIL was more effective than either the 1396-11 and TRAIL or nutlin3a and TRAIL combinations in OCI-AML3 cells, further supporting the role of triptolide as a sensitizer to TRAIL-induced apoptosis in part by independent modulation of XIAP expression and p53 signaling. Thus, the combination of triptolide and TRAIL may provide a novel strategy for treating AML by overcoming critical mechanisms of apoptosis resistance. PMID:18187663

  11. A human papillomavirus type 18 E6/E7 transgene sensitizes mouse lens cells to human wild-type p53-mediated apoptosis.

    PubMed

    Nakamura, T; Williams-Simons, L; Westphal, H

    1997-06-26

    We have studied the concerted action of factors that influence the balance between cell proliferation and cell death in the developing lens of transgenic mice. We show that a human papillomavirus type 18 (HPV18) E6/E7 transgene that predominantly expresses the viral E7 gene product triggers apoptosis in a dose dependent manner, and causes retardation of lens growth or microphakia. E7 is known to inactivate pRB, the product of the retinoblastoma gene, and to enhance the action of p53. Our earlier work had demonstrated that over-expression of p53 itself can cause apoptosis of lens cells, and that a mutant p53 allele can interfere with this process. In the present study, we examined lenses that simultaneously express different constellations of the HPV18 E6/E7, wild-type and mutant human p53, and wild-type human pRB transgenes. We observed that lens cells expressing the HPV18 transgene are more sensitive to wild-type human p53 action than normal lens cells. As a result, there is severe microphakia in lenses that express both the HPV18 and the wild-type p53 transgenes. By contrast, apoptosis was reduced in lenses that co-expressed the HPV18 and either the pRB or the mutant p53 transgene. We conclude that levels of wild-type p53 are critical, and that any excess of p53 or suppression of pRB can cause cell death. Our results encourage attempts to counteract the deleterious action of human papillomaviruses in cervical cancer by a combination of measures that decrease cell proliferation and enhance apoptosis. PMID:9223662

  12. CPUY201112, a novel synthetic small-molecule compound and inhibitor of heat shock protein Hsp90, induces p53-mediated apoptosis in MCF-7 cells

    PubMed Central

    Xu, Xiao-Li; Bao, Qi-chao; Jia, Jian-Min; Liu, Fang; Guo, Xiao-Ke; Zhang, Ming-ye; Wei, Jin-lian; Lu, Meng-chen; Xu, Li-li; Zhang, Xiao-Jin; You, Qi-Dong; Sun, Hao-Peng

    2016-01-01

    Heat-shock protein 90 (Hsp90) is highly expressed in many tumor cells and is associated with the maintenance of malignant phenotypes. Targeting Hsp90 has had therapeutic success in both solid and hematological malignancies, which has inspired more studies to identify new Hsp90 inhibitors with improved clinical efficacy. Using a fragment-based approach and subsequent structural optimization guided by medicinal chemistry principles, we identified the novel compound CPUY201112 as a potent Hsp90 inhibitor. It binds to the ATP-binding pocket of Hsp90 with a kinetic dissociation (Kd) constant of 27 ± 2.3 nM. It also exhibits potent in vitro antiproliferative effects in a range of solid tumor cells. In MCF-7 cells with high Hsp90 expression, CPUY201112 induces the degradation of Hsp90 client proteins including HER-2, Akt, and c-RAF. We prove that treating MCF-7 cells with CPUY201112 results in cell cycle arrest and apoptosis through the wild-type (wt) p53 pathway. CPUY201112 also synergizes with Nutlin-3a to induce cancer cell apoptosis. CPUY201112 significantly inhibited the growth of MCF-7 xenografts in nude mice without apparent body weight loss. These results demonstrate that CPUY201112 is a novel Hsp90 inhibitor with potential use in treating wild-type p53 related cancers. PMID:26743233

  13. FFA-ROS-P53-mediated mitochondrial apoptosis contributes to reduction of osteoblastogenesis and bone mass in type 2 diabetes mellitus

    PubMed Central

    Li, Jun; He, Wang; Liao, Bo; Yang, Jingyue

    2015-01-01

    This study evaluated the association between free fatty acid (FFA), ROS generation, mitochondrial dysfunction and bone mineral density (BMD) in type 2 diabetic patients and investigated the molecular mechanism. db/db and high fat (HF)-fed mice were treated by Etomoxir, an inhibitor of CPT1, MitoQ, and PFT-α, an inhibitor of P53. Bone metabolic factors were assessed and BMSCs were isolated and induced to osteogenic differentiation. FFA, lipid peroxidation and mtDNA copy number were correlated with BMD in T2DM patients. Etomoxir, MitoQ and PFT-α significantly inhibited the decrease of BMD and bone breaking strength in db/db and HF-fed mice and suppressed the reduction of BMSCs-differentiated osteoblasts. Etomoxir and MitoQ, but not PFT-α, inhibited the increase of mitochondrial ROS generation in db/db and HF-fed mice and osteoblasts. In addition, Etomoxir, MitoQ and PFT-α significantly inhibited mitochondrial dysfunction in osteoblasts. Moreover, mitochondrial apoptosis was activated in osteoblasts derived from db/db and HF-fed mice, which was inhibited by Etomoxir, MitoQ and PFT-α. Furthermore, mitochondrial accumulation of P53 recruited Bax and initiated molecular events of apoptotic events. These results demonstrated that fatty acid oxidation resulted in ROS generation, activating P53/Bax-mediated mitochondrial apoptosis, leading to reduction of osteogenic differentiation and bone loss in T2DM. PMID:26226833

  14. Profiling Dose-Dependent Activation of p53-Mediated Signaling Pathways by Chemicals with Distinct Mechanisms of DNA Damage

    PubMed Central

    Clewell, Rebecca A.; Sun, Bin; Adeleye, Yeyejide; Carmichael, Paul; Efremenko, Alina; McMullen, Patrick D.; Pendse, Salil; Trask, O. J.; White, Andy; Andersen, Melvin E.

    2014-01-01

    As part of a larger effort to provide proof-of-concept in vitro-only risk assessments, we have developed a suite of high-throughput assays for key readouts in the p53 DNA damage response toxicity pathway: double-strand break DNA damage (p-H2AX), permanent chromosomal damage (micronuclei), p53 activation, p53 transcriptional activity, and cell fate (cell cycle arrest, apoptosis, micronuclei). Dose-response studies were performed with these protein and cell fate assays, together with whole genome transcriptomics, for three prototype chemicals: etoposide, quercetin, and methyl methanesulfonate. Data were collected in a human cell line expressing wild-type p53 (HT1080) and results were confirmed in a second p53 competent cell line (HCT 116). At chemical concentrations causing similar increases in p53 protein expression, p53-mediated protein expression and cellular processes showed substantial chemical-specific differences. These chemical-specific differences in the p53 transcriptional response appear to be determined by augmentation of the p53 response by co-regulators. More importantly, dose-response data for each of the chemicals indicate that the p53 transcriptional response does not prevent micronuclei induction at low concentrations. In fact, the no observed effect levels and benchmark doses for micronuclei induction were less than or equal to those for p53-mediated gene transcription regardless of the test chemical, indicating that p53's post-translational responses may be more important than transcriptional activation in the response to low dose DNA damage. This effort demonstrates the process of defining key assays required for a pathway-based, in vitro-only risk assessment, using the p53-mediated DNA damage response pathway as a prototype. PMID:25078064

  15. Anti-lung cancer potential of pure esteric-glycoside condurangogenin A against nonsmall-cell lung cancer cells in vitro via p21/p53 mediated cell cycle modulation and DNA damage-induced apoptosis

    PubMed Central

    Sikdar, Sourav; Mukherjee, Avinaba; Khuda-Bukhsh, Anisur Rahman

    2015-01-01

    Background: Marsdenia condurango (condurango) is a tropical woody vine native to South America. Our earlier study was limited to evaluation of anti-cancer potentials of crude condurango extract and its glycoside-rich components in vitro on lung cancer. Objective: This study aims at evaluating the effect of the single isolated active ingredient condurangogenin A (ConA; C32H42O7) on A549, H522 and H460-nonsmall-cell lung cancer cells. Materials and Methods: ConA was isolated by column chromatography and analyzed by mass spectroscopy, Fourier transform infrared spectroscopy and proton-nuclear magnetic resonance. diphenyltetrazolium bromide assays were conducted on three cell-types using 6%-alcohol as control. Critical studies on cellular morphology, cell-cycle regulation, reactive oxygen species, mitochondrial membrane potential, and DNA-damage were made, and expressions of related signaling markers studied. Results: As IC50 doses of ConA proved to be too high and toxic to both A549 and H522 cells, all experimental studies were carried out on H460 cells with the IC50 dose (32 μg/ml − 24 h). Cellular morphology revealed typical apoptotic features after ConA treatment. At early treatment hours (2 h-12 h), maximum cells were arrested at G0/G1 phase that could be correlated with reduced level of cyclin D1-CDK with p21 up-regulation. At 18 h − 24 h, sub G0/G1 cell population was increased gradually, as revealed from cytochrome-c release and caspase-3 activation, further confirming the apoptosis-inducing ability of ConA at later phases. Gradual increase of TUNEL-positive cells with significant modulation of mitochondria-dependent apoptotic markers at longer time-points would establish apoptosis-induction property of ConA, indicating its potential as a strong candidate for anti-cancer drug formulation. Conclusion: Further studies are warranted against other types of cancer cells and animal models before its possible human use. PMID:26109778

  16. RNF43 interacts with NEDL1 and regulates p53-mediated transcription

    SciTech Connect

    Shinada, Keisuke; Tsukiyama, Tadasuke; Sho, Takuya; Okumura, Fumihiko; Asaka, Masahiro; Hatakeyama, Shigetsugu

    2011-01-07

    Research highlights: {yields} RNF43 binds to NEDD-4-like ubiquitin-protein ligase-1 (NEDL1). {yields} RNF43 interacts with p53 and suppresses transcriptional activity of p53. {yields} RNF43 attenuates apoptosis induced by ultraviolet irradiation. {yields} RNF43 is likely associated with p53-mediated apoptosis in collaboration with NEDL1 in colorectal carcinogenesis. -- Abstract: The ubiquitin-proteasomal system plays a crucial role in oncogenesis in colorectal tissues. Recent studies have shown that stability of {beta}-catenin, which functions as an oncogene for colorectal cancer, is regulated by ubiquitin-mediated degradation. It has been reported that a putative E3 ubiquitin ligase, RNF43, is highly expressed in human colorectal carcinoma and that RNF43 promotes cell growth. However, the involvement of RNF43 in carcinogenesis has not been fully elucidated. In this study, we found by using yeast two-hybrid screening that RNF43 binds to NEDD-4-like ubiquitin-protein ligase-1 (NEDL1), which enhances pro-apoptotic activity by p53. In addition, we found that RNF43 also interacts with p53 and that RNF43 suppresses transcriptional activity of p53 in H1299 cells and attenuates apoptosis induced by ultraviolet irradiation. These findings suggest that RNF43 is associated with p53-mediated apoptosis in collaboration with NEDL1 in colorectal carcinogenesis.

  17. p53-Mediated Cellular Response to DNA Damage in Cells with Replicative Hepatitis B Virus

    NASA Astrophysics Data System (ADS)

    Puisieux, Alain; Ji, Jingwei; Guillot, Celine; Legros, Yann; Soussi, Thierry; Isselbacher, Kurt; Ozturk, Mehmet

    1995-02-01

    Wild-type p53 acts as a tumor suppressor gene by protecting cells from deleterious effects of genotoxic agents through the induction of a G_1/S arrest or apoptosis as a response to DNA damage. Transforming proteins of several oncogenic DNA viruses inactivate tumor suppressor activity of p53 by blocking this cellular response. To test whether hepatitis B virus displays a similar effect, we studied the p53-mediated cellular response to DNA damage in 2215 hepatoma cells with replicative hepatitis B virus. We demonstrate that hepatitis B virus replication does not interfere with known cellular functions of p53 protein.

  18. Development of a mechanistically-based genetically engineered PC12 cell system to detect p53-mediated cytotoxicity.

    PubMed

    van Vliet, Erwin; Eskes, Chantra; Stingele, Silvia; Gartlon, Joanne; Price, Anna; Farina, Massimo; Ponti, Jessica; Hartung, Thomas; Sabbioni, Enrico; Coecke, Sandra

    2007-06-01

    The human wild type p53 gene, key for apoptosis, was introduced into the pheochromocytoma (PC12) cell line, to create a mechanistically-based in vitro test model for the detection of p53-mediated toxicity. Expression of the wt p53 gene was regulated by a system, which allowed or blocked expression p53 by absence or presence of tetracycline in the culture media. Western blot analyses confirmed an inducible and tetracycline-dependent expression of the wt p53 protein. Functionality of the p53 protein was verified by camptothecin treatment, known to induce p53-dependent apoptosis. Results showed that p53-expressing cells were significantly more sensitive to camptothecin induced cytotoxicity compared to non-expressing cells, and presented a significantly higher incidence of apoptosis. A screening study on 31 metal compounds, showed that the classified human carcinogens (NaAsO2, CdSO4 .8H2O, Na2CrO4 .4H2O, MnCl2, (NH4)2PtCl6) significantly increased cytotoxicity in p53-expressing cells compared to non-expressing cells, suggesting that their cytotoxicity was p53-mediated. Finally, acute and subchronic treatment with methyl mercury showed no significant differences in cytotoxicity and the percentage of apoptosis or necrosis between p53-expressing and non-expressing differentiated cells, suggesting that methyl mercury cytotoxicity was p53-independent. PMID:17258428

  19. Simian virus 40 T antigen can regulate p53-mediated transcription independent of binding p53.

    PubMed Central

    Rushton, J J; Jiang, D; Srinivasan, A; Pipas, J M; Robbins, P D

    1997-01-01

    A simian virus 40 (SV40) T-antigen mutant containing only the N-terminal 136 amino acids, able to bind to Rb and p300 but not p53, partially inhibited p53-mediated transcription without affecting the ability of p53 to bind DNA. These results suggest that SV40 T antigen can regulate p53-mediated transcription either directly through protein-protein association or indirectly through interaction with factors which may function to confer p53-mediated transcription. PMID:9188637

  20. ASPP2 involvement in p53-mediated HIV-1 envelope glycoprotein gp120 neurotoxicity in mice cerebrocortical neurons.

    PubMed

    Liu, Zhiying; Zang, Yunjin; Qiao, Luxin; Liu, Kai; Ouyang, Yabo; Zhang, Yulin; Chen, Dexi

    2016-01-01

    The mechanisms behind HIV-1-associated neurocognitive disorders are still unclear. Apoptosis-stimulating protein 2 of p53 (ASPP2) is a damage-inducible p53-binding protein that stimulates p53-mediated apoptosis and transactivates proapoptotic and cell cycle regulatory genes. It has been reported that ASPP2 has a specific regulatory function in the death of retinal ganglion cells and the development of Alzheimer's disease. In this study, we used p53 and ASPP2 knockout mice and primary cerebrocortical neuron culture to analyze the role of the interaction between ASPP2 with p53 in HIV-1 envelope glycoprotein gp120-induced neurotoxicity. The results showed that 10 ng/mL gp120 protein might stimulate p53 overexpression and translocation to the nucleus, and 30 ng/mL gp120 protein could stimulate both p53 and ASPP2 translocation to the nucleus, but only with p53 overexpression. The primary cultured neurons of p53(-/-)ASPP2(+/-) mice had a higher survival rate than p53(-/-) mice under gp120 protein stress. The interaction of ASPP2 with p53 induced by a high dose of gp120 stimulated Bax transcription and contributed to caspase-3 cleavage, and ASPP2-siRNA attenuated gp120 induced neuron death through inhibition of Bax expression. These results suggest that ASPP2 plays an important role in p53-mediated neuronal apoptosis under gp120 stress. PMID:27625111

  1. S-Nitrosylation of parkin as a novel regulator of p53-mediated neuronal cell death in sporadic Parkinson’s disease

    PubMed Central

    2013-01-01

    Background Mutations in the gene encoding parkin, a neuroprotective protein with dual functions as an E3 ubiquitin ligase and transcriptional repressor of p53, are linked to familial forms of Parkinson’s disease (PD). We hypothesized that oxidative posttranslational modification of parkin by environmental toxins may contribute to sporadic PD. Results We first demonstrated that S-nitrosylation of parkin decreased its activity as a repressor of p53 gene expression, leading to upregulation of p53. Chromatin immunoprecipitation as well as gel-shift assays showed that parkin bound to the p53 promoter, and this binding was inhibited by S-nitrosylation of parkin. Additionally, nitrosative stress induced apoptosis in cells expressing parkin, and this death was, at least in part, dependent upon p53. In primary mesencephalic cultures, pesticide-induced apoptosis was prevented by inhibition of nitric oxide synthase (NOS). In a mouse model of pesticide-induced PD, both S-nitrosylated (SNO-)parkin and p53 protein levels were increased, while administration of a NOS inhibitor mitigated neuronal death in these mice. Moreover, the levels of SNO-parkin and p53 were simultaneously elevated in postmortem human PD brain compared to controls. Conclusions Taken together, our data indicate that S-nitrosylation of parkin, leading to p53-mediated neuronal cell death, contributes to the pathophysiology of sporadic PD. PMID:23985028

  2. Titanium dioxide nanoparticles trigger p53-mediated damage response in peripheral blood lymphocytes.

    PubMed

    Kang, Su Jin; Kim, Byeong Mo; Lee, Young Joon; Chung, Hai Won

    2008-06-01

    Titanium dioxide nanoparticles (nano-TiO2) are widely used as a photocatalyst in air and water remediation. These nanoparticles are known to induce toxicity; however, their cytotoxic mechanism is not fully understood. In this study, we investigated the underlying mechanism of nano-TiO2-induced cytotoxicity in peripheral blood lymphocytes. We examined the genotoxic effects of nano-TiO2 in lymphocytes using alkaline single-cell gel electrophoresis (Comet) and cytokinesis-block micronucleus (CBMN) assays. Lymphocytes treated with nano-TiO2 showed significantly increased micronucleus formation and DNA breakage. Western-blot analysis to identify proteins involved in the p53-mediated response to DNA damage revealed the accumulation of p53 and activation of DNA damage checkpoint kinases in nano-TiO2-treated lymphocytes. However, p21 and bax, downstream targets of p53, were not affected, indicating that nano-TiO2 does not stimulate transactivational activity of p53. The generation of reactive oxygen species (ROS) in nano-TiO2-treated cells was also observed, andN-acetylcysteine (NAC) supplementation inhibited the level of nano-TiO2-induced DNA damage. Given that ROS-induced DNA damage leads to p53 activation in the DNA damage response, our results suggest that nano-TiO2 induces ROS generation in lymphocytes, thereby activating p53-mediated DNA damage checkpoint signals. PMID:18418868

  3. Mammary gland-specific ablation of focal adhesion kinase reduces the incidence of p53-mediated mammary tumour formation

    PubMed Central

    van Miltenburg, M H A M; van Nimwegen, M J; Tijdens, I; Lalai, R; Kuiper, R; Klarenbeek, S; Schouten, P C; de Vries, A; Jonkers, J; van de Water, B

    2014-01-01

    kinase deletion reduced proliferative capacity of p53 null and p53R270H mammary epithelial cells but did not lead to increased apoptosis in vivo. Our data identify FAK as an important regulator in mammary epithelial cell proliferation in p53-mediated and p53R270H-induced mammary tumour development. PMID:24809783

  4. P53-mediated rapid induction of apoptosis conveys resistance to viral infection in Drosophila melanogaster

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Arthropod-borne pathogens account for millions of deaths each year. Understanding the genetic mechanisms controlling vector susceptibility to pathogens has profound implications for developing novel strategies for controlling insect transmitted infectious diseases. The fact that many viruses carry...

  5. Dephosphorylation of DBC1 by Protein Phosphatase 4 Is Important for p53-Mediated Cellular Functions

    PubMed Central

    Lee, Jihye; Adelmant, Guillaume; Marto, Jarrod A.; Lee, Dong-Hyun

    2015-01-01

    Deleted in breast cancer-1 (DBC1) contributes to the regulation of cell survival and apoptosis. Recent studies demonstrated that DBC is phosphorylated at Thr454 by ATM/ATR kinases in response to DNA damage, which is a critical event for p53 activation and apoptosis. However, how DBC1 phosphorylation is regulated has not been studied. Here we show that protein phosphatase 4 (PP4) dephosphorylates DBC1, regulating its role in DNA damage response. PP4R2, a regulatory subunit of PP4, mediates the interaction between DBC1 and PP4C, a catalytic subunit. PP4C efficiently dephosphorylates pThr454 on DBC1 in vitro, and the depletion of PP4C/PP4R2 in cells alters the kinetics of DBC1 phosphorylation and p53 activation, and increases apoptosis in response to DNA damage, which are compatible with the expression of the phosphomimetic DBC-1 mutant (T454E). These suggest that the PP4-mediated dephosphorylation of DBC1 is necessary for efficient damage responses in cells. PMID:26194823

  6. Dephosphorylation of DBC1 by Protein Phosphatase 4 Is Important for p53-Mediated Cellular Functions.

    PubMed

    Lee, Jihye; Adelmant, Guillaume; Marto, Jarrod A; Lee, Dong-Hyun

    2015-08-01

    Deleted in breast cancer-1 (DBC1) contributes to the regulation of cell survival and apoptosis. Recent studies demonstrated that DBC is phosphorylated at Thr454 by ATM/ATR kinases in response to DNA damage, which is a critical event for p53 activation and apoptosis. However, how DBC1 phosphorylation is regulated has not been studied. Here we show that protein phosphatase 4 (PP4) dephosphorylates DBC1, regulating its role in DNA damage response. PP4R2, a regulatory subunit of PP4, mediates the interaction between DBC1 and PP4C, a catalytic subunit. PP4C efficiently dephosphorylates pThr454 on DBC1 in vitro, and the depletion of PP4C/PP4R2 in cells alters the kinetics of DBC1 phosphorylation and p53 activation, and increases apoptosis in response to DNA damage, which are compatible with the expression of the phosphomimetic DBC-1 mutant (T454E). These suggest that the PP4-mediated dephosphorylation of DBC1 is necessary for efficient damage responses in cells. PMID:26194823

  7. The p53-mediated cytotoxicity of photodynamic therapy of cancer: Recent advances

    SciTech Connect

    Zawacka-Pankau, Joanna Krachulec, Justyna Grulkowski, Ireneusz Bielawski, Krzysztof P. Selivanova, Galina

    2008-11-01

    Photodynamic therapy (PDT) is a promising modality for the treatment of both pre-malignant and malignant lesions. The mechanism of action converges mainly on the generation of reactive oxygen species which damage cancer cells directly as well as indirectly acting on tumor vasculature. The exact mechanism of PDT action is not fully understood, which is a formidable barrier to its successful clinical application. Elucidation of the mechanisms of cancer cell elimination by PDT might help in establishing highly specific, non-genotoxic anti-cancer treatment of tomorrow. One of the candidate PDT targets is the well-known tumor suppressor p53 protein recognized as the guardian of the genome. Together with its family members, p73 and p63 proteins, p53 is involved in apoptosis induction upon stress stimuli. The wild-type and mutant p53-targeting chemotherapeutics are currently extensively investigated as a promising strategy for highly specific anti-cancer therapy. In photodynamic therapy porphyrinogenic sensitizers are the most widely used compounds due to their potent biophysical and biochemical properties. Recent data suggest that the p53 tumor suppressor protein might play a significant role in porphyrin-PDT-mediated cell death by direct interaction with the drug which leads to its accumulation and induction of p53-dependent cell death both in the dark and upon irradiation. In this review we describe the available evidence on the role of p53 in PDT.

  8. Loss of Atrx sensitizes cells to DNA damaging agents through p53-mediated death pathways.

    PubMed

    Conte, Damiano; Huh, Michael; Goodall, Emma; Delorme, Marilyne; Parks, Robin J; Picketts, David J

    2012-01-01

    Prevalent cell death in forebrain- and Sertoli cell-specific Atrx knockout mice suggest that Atrx is important for cell survival. However, conditional ablation in other tissues is not associated with increased death indicating that diverse cell types respond differently to the loss of this chromatin remodeling protein. Here, primary macrophages isolated from Atrx(f/f) mice were infected with adenovirus expressing Cre recombinase or β-galactosidase, and assayed for cell survival under different experimental conditions. Macrophages survive without Atrx but undergo rapid apoptosis upon lipopolysaccharide (LPS) activation suggesting that chromatin reorganization in response to external stimuli is compromised. Using this system we next tested the effect of different apoptotic stimuli on cell survival. We observed that survival of Atrx-null cells were similar to wild type cells in response to serum withdrawal, anti-Fas antibody, C2 ceramide or dexamethasone treatment but were more sensitive to 5-fluorouracil (5-FU). Cell survival could be rescued by re-introducing Atrx or by removal of p53 demonstrating the cell autonomous nature of the effect and its p53-dependence. Finally, we demonstrate that multiple primary cell types (myoblasts, embryonic fibroblasts and neurospheres) were sensitive to 5-FU, cisplatin, and UV light treatment. Together, our results suggest that cells lacking Atrx are more sensitive to DNA damaging agents and that this may result in enhanced death during development when cells are at their proliferative peak. Moreover, it identifies potential treatment options for cancers associated with ATRX mutations, including glioblastoma and pancreatic neuroendocrine tumors. PMID:23284920

  9. Highly specific in vivo gene delivery for p53-mediated apoptosis and genetic photodynamic therapies of tumour

    PubMed Central

    Tseng, S.-Ja; Liao, Zi-Xian; Kao, Shih-Han; Zeng, Yi-Fang; Huang, Kuo-Yen; Li, Hsin-Jung; Yang, Chung-Lin; Deng, Yu-Fan; Huang, Chi-Feng; Yang, Shuenn-Chen; Yang, Pan-Chyr; Kempson, Ivan M.

    2015-01-01

    Anticancer therapies are often compromised by nonspecific effects and challenged by tumour environments’ inherent physicochemical and biological characteristics. Often, therapeutic effect can be increased by addressing multiple parameters simultaneously. Here we report on exploiting extravasation due to inherent vascular leakiness for the delivery of a pH-sensitive polymer carrier. Tumours’ acidic microenvironment instigates a charge reversal that promotes cellular internalization where endosomes destabilize and gene delivery is achieved. We assess our carrier with an aggressive non-small cell lung carcinoma (NSCLC) in vivo model and achieve >30% transfection efficiency via systemic delivery. Rejuvenation of the p53 apoptotic pathway as well as expression of KillerRed protein for sensitization in photodynamic therapy (PDT) is accomplished. A single administration greatly suppresses tumour growth and extends median animal survival from 28 days in control subjects to 68 days. The carrier has capacity for multiple payloads for greater therapeutic response where inter-individual variability can compromise efficacy. PMID:25739372

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

    PubMed

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

    2013-04-01

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

  11. SETD2 is required for DNA double-strand break repair and activation of the p53-mediated checkpoint

    PubMed Central

    Carvalho, Sílvia; Vítor, Alexandra C; Sridhara, Sreerama C; Martins, Filipa B; Raposo, Ana C; Desterro, Joana MP; Ferreira, João; de Almeida, Sérgio F

    2014-01-01

    Histone modifications establish the chromatin states that coordinate the DNA damage response. In this study, we show that SETD2, the enzyme that trimethylates histone H3 lysine 36 (H3K36me3), is required for ATM activation upon DNA double-strand breaks (DSBs). Moreover, we find that SETD2 is necessary for homologous recombination repair of DSBs by promoting the formation of RAD51 presynaptic filaments. In agreement, SETD2-mutant clear cell renal cell carcinoma (ccRCC) cells displayed impaired DNA damage signaling. However, despite the persistence of DNA lesions, SETD2-deficient cells failed to activate p53, a master guardian of the genome rarely mutated in ccRCC and showed decreased cell survival after DNA damage. We propose that this novel SETD2-dependent role provides a chromatin bookmarking instrument that facilitates signaling and repair of DSBs. In ccRCC, loss of SETD2 may afford an alternative mechanism for the inactivation of the p53-mediated checkpoint without the need for additional genetic mutations in TP53. DOI: http://dx.doi.org/10.7554/eLife.02482.001 PMID:24843002

  12. Ets-2 and p53 mediate cAMP-induced MMP-2 expression, activity and trophoblast invasion

    PubMed Central

    2009-01-01

    Background We have previously shown that Matrix metalloproteinase (MMP) -2 is a key-enzyme in early trophoblast invasion and that Protein Kinase A (PKA) increases MMP-2 expression and trophoblast invasion. The aim of this study was to examine MMP -2 regulation by PKA in invasive trophoblasts: JAR choriocarcinoma cell-line and 6-8 w first trimester trophoblasts. Methods The effect of Forskolin (PKA) on MMP-2 expression was assessed by Northern Blot and RT-PCR. Possible transcription factors binding to consensus MMP-2 promoter sequences in response to Forskolin, were detected by EMSA binding assay and their expression assessed by western blot analysis. Antisense transfection of relevant transcription factors was performed and the inhibitory effect assessed on MMP-2 expression (RT-PCR), secretion (zymography) and trophoblast invasiveness (transwell migration assay). Results We found that Forskolin increased MMP-2 mRNA in JAR cells within 24 hours, and induced binding to p53, Ets, C/EBP and AP-2. Transcription factors Ets-2, phospho- p53, C/EBP epsilon, C/EBP lambda and AP-2 alpha bound to their respective binding sequences in response to Forskolin and the expressions of these transcription factors were all elevated in Forskolin- treated cells. Inhibition of Ets-2 and p53 reduced MMP-2 expression, secretion and invasiveness of Forskolin treated cells. Conclusion MMP-2 is regulated by PKA through several binding sites and transcription factors including Ets-2, p53, C/EBP, C/EBP lambda and AP-2 alpha. Ets-2 and p53 mediate cAMP- induced trophoblast invasiveness, through regulation of MMP-2. PMID:19939245

  13. CHIP stabilizes amyloid precursor protein via proteasomal degradation and p53-mediated trans-repression of β-secretase.

    PubMed

    Singh, Amir Kumar; Pati, Uttam

    2015-08-01

    In patient with Alzheimer's disease (AD), deposition of amyloid-beta Aβ, a proteolytic cleavage of amyloid precursor protein (APP) by β-secretase/BACE1, forms senile plaque in the brain. BACE1 activation is caused due to oxidative stresses and dysfunction of ubiquitin-proteasome system (UPS), which is linked to p53 inactivation. As partial suppression of BACE1 attenuates Aβ generation and AD-related pathology, it might be an ideal target for AD treatment. We have shown that both in neurons and in HEK-APP cells, BACE1 is a new substrate of E3-ligase CHIP and an inverse relation exists between CHIP and BACE1 level. CHIP inhibits ectopic BACE1 level by promoting its ubiquitination and proteasomal degradation, thus reducing APP processing; it stabilizes APP in neurons, thus reducing Aβ. CHIP(U) (box) domain physically interacts with BACE1; however, both U-box and TPR domain are essential for ubiquitination and degradation of BACE1. Further, BACE1 is a downstream target of p53 and overexpression of p53 decreases BACE1 level. In HEK-APP cells, CHIP is shown to negatively regulate BACE1 promoter through stabilization of p53's DNA-binding conformation and its binding upon 5' UTR element (+127 to +150). We have thus discovered that CHIP regulates p53-mediated trans-repression of BACE1 at both transcriptional and post-translational level. We propose that a CHIP-BACE1-p53 feedback loop might control APP stabilization, which could further be utilized for new therapeutic intervention in AD. PMID:25773675

  14. CHIP stabilizes amyloid precursor protein via proteasomal degradation and p53-mediated trans-repression of β-secretase

    PubMed Central

    Singh, Amir Kumar; Pati, Uttam

    2015-01-01

    In patient with Alzheimer’s disease (AD), deposition of amyloid-beta Aβ, a proteolytic cleavage of amyloid precursor protein (APP) by β-secretase/BACE1, forms senile plaque in the brain. BACE1 activation is caused due to oxidative stresses and dysfunction of ubiquitin–proteasome system (UPS), which is linked to p53 inactivation. As partial suppression of BACE1 attenuates Aβ generation and AD-related pathology, it might be an ideal target for AD treatment. We have shown that both in neurons and in HEK-APP cells, BACE1 is a new substrate of E3-ligase CHIP and an inverse relation exists between CHIP and BACE1 level. CHIP inhibits ectopic BACE1 level by promoting its ubiquitination and proteasomal degradation, thus reducing APP processing; it stabilizes APP in neurons, thus reducing Aβ. CHIPUbox domain physically interacts with BACE1; however, both U-box and TPR domain are essential for ubiquitination and degradation of BACE1. Further, BACE1 is a downstream target of p53 and overexpression of p53 decreases BACE1 level. In HEK-APP cells, CHIP is shown to negatively regulate BACE1 promoter through stabilization of p53’s DNA-binding conformation and its binding upon 5′ UTR element (+127 to +150). We have thus discovered that CHIP regulates p53-mediated trans-repression of BACE1 at both transcriptional and post-translational level. We propose that a CHIP–BACE1–p53 feedback loop might control APP stabilization, which could further be utilized for new therapeutic intervention in AD. PMID:25773675

  15. p53-Mediated Biliary Defects Caused by Knockdown of cirh1a, the Zebrafish Homolog of the Gene Responsible for North American Indian Childhood Cirrhosis

    PubMed Central

    Wilkins, Benjamin J.; Lorent, Kristin; Matthews, Randolph P.; Pack, Michael

    2013-01-01

    North American Indian Childhood Cirrhosis (NAIC) is a rare, autosomal recessive, progressive cholestatic disease of infancy affecting the Cree-Ojibway first Nations of Quebec. All NAIC patients are homozygous for a missense mutation (R565W) in CIRH1A, the human homolog of the yeast nucleolar protein Utp4. Utp4 is part of the t-Utp subcomplex of the small subunit (SSU) processome, a ribonucleoprotein complex required for ribosomal RNA processing and small subunit assembly. NAIC has thus been proposed to be a primary ribosomal disorder (ribosomopathy); however, investigation of the pathophysiologic mechanism of this disease has been hindered by lack of an animal model. Here, using a morpholino oligonucleotide (MO)-based loss-of-function strategy, we have generated a model of NAIC in the zebrafish, Danio rerio. Zebrafish Cirhin shows substantial homology to the human homolog, and cirh1a mRNA is expressed in developing hepatocytes and biliary epithelial cells. Injection of two independent MOs directed against cirh1a at the one-cell stage causes defects in canalicular and biliary morphology in 5 dpf larvae. In addition, 5 dpf Cirhin-deficient larvae have dose-dependent defects in hepatobiliary function, as assayed by the metabolism of an ingested fluorescent lipid reporter. Previous yeast and in vitro studies have shown that defects in ribosome biogenesis cause stabilization and nuclear accumulation of p53, which in turn causes p53-mediated cell cycle arrest and/or apoptosis. Thus, the nucleolus appears to function as a cellular stress sensor in some cell types. In accordance with this hypothesis, transcriptional targets of p53 are upregulated in Cirhin-deficient zebrafish embryos, and defects in biliary function seen in Cirhin-deficient larvae are completely abrogated by mutation of tp53. Our data provide the first in vivo evidence of a role for Cirhin in biliary development, and support the hypothesis that congenital defects affecting ribosome biogenesis can activate

  16. The novel tryptamine derivative JNJ-26854165 induces wild-type p53- and E2F1-mediated apoptosis in acute myeloid and lymphoid leukemias

    PubMed Central

    Kojima, Kensuke; Burks, Jared K.; Arts, Janine; Andreeff, Michael

    2010-01-01

    Development of small-molecule activators of p53 is currently focused on malignancies containing a wild-type p53 genotype, which is present in most leukemias. JNJ-26854165 is one of such p53-activating agents, but its mechanism of action remains to be elucidated. Here, we report the effects of JNJ-26854165 in acute leukemias. JNJ-26854165 treatment induced p53-mediated apoptosis in acute leukemia cells with wild-type p53, in which p53 rapidly drives transcription-independent apoptosis followed by activation of a transcription-dependent pathway. JNJ-26854165 accelerated the proteasome-mediated degradation of p21, and antagonized the transcriptional induction of p21 by p53. Interestingly, JNJ-26854165 induced S-phase delay and upregulated E2F1 expression in p53 mutant cells, resulting in apoptosis preferentially of S-phase cells. E2F1 knockdown blocked apoptosis induced by JNJ-26854165 in p53 mutant cells. Apoptotic activity of JNJ-26854165 against primary acute leukemia cells was maintained in leukemia/stroma cocultures, unlike doxorubicin, which has reduced cytrotoxicity in coculture systems. JNJ-26854165 synergizes with AraC or doxorubicin to induce p53-mediated apoptosis. Our data suggest that JNJ-26854165 may provide a novel therapeutic approach for the treatment of acute leukemias. The presence of p53-independent apoptotic activity in addition to p53-mediated apoptosis induction, if operational in vivo, may prevent the selection of p53 mutant subclones during therapy. PMID:20736344

  17. Escape from p53-mediated tumor surveillance in neuroblastoma: switching off the p14(ARF)-MDM2-p53 axis.

    PubMed

    Van Maerken, T; Vandesompele, J; Rihani, A; De Paepe, A; Speleman, F

    2009-12-01

    A primary failsafe program against unrestrained proliferation and oncogenesis is provided by the p53 tumor suppressor protein, inactivation of which is considered as a hallmark of cancer. Intriguingly, mutations of the TP53 gene are rarely encountered in neuroblastoma tumors, suggesting that alternative p53-inactivating lesions account for escape from p53 control in this childhood malignancy. Several recent studies have shed light on the mechanisms by which neuroblastoma cells circumvent the p53-driven antitumor barrier. We review here these mechanisms for evasion of p53-mediated growth control and conclude that deregulation of the p14(ARF)-MDM2-p53 axis seems to be the principal mode of p53 inactivation in neuroblastoma, opening new perspectives for targeted therapeutic intervention. PMID:19779493

  18. Wild-type and mutant p53 mediate cisplatin resistance through interaction and inhibition of active caspase-9.

    PubMed

    Chee, Jacqueline L Y; Saidin, Suzan; Lane, David P; Leong, Sai Mun; Noll, Jacqueline E; Neilsen, Paul M; Phua, Yi Ting; Gabra, Hani; Lim, Tit Meng

    2013-01-15

    The p53 gene has been implicated in many cancers due to its frequent mutations as well as mutations in other genes whose proteins directly affect p53's functions. In addition, high expression of p53 [wild-type (WT) or mutant] has been found in the cytoplasm of many tumor cells, and studies have associated these observations with more aggressive tumors and poor prognosis. Cytoplasmic mis-localization of p53 subsequently reduced its transcriptional activity and this loss-of-function (LOF) was used to explain the lack of response to chemotherapeutic agents. However, this hypothesis seemed inadequate in explaining the apparent selection for tumor cells with high levels of p53 protein, a phenomenon that suggests a gain-of-function (GOF) of these mis-localized p53 proteins. In this study, we explored whether the direct involvement of p53 in the apoptotic response is via regulation of the caspase pathway in the cytoplasm. We demonstrate that p53, when present at high levels in the cytoplasm, has an inhibitory effect on caspase-9. Concurrently, knockdown of endogenous p53 caused an increase in the activity of caspase-9. p53 was found to interact with the p35 fragment of caspase-9, and this interaction inhibits the caspase-9 activity. In a p53-null background, the high-level expression of both exogenous WT and mutant p53 increased the resistance of these cells to cisplatin, and the data showed a correlation between high p53 expression and caspase-9 inhibition. These results suggest the inhibition of caspase-9 as a potential mechanism in evading apoptosis in tumors with high-level p53 expression that is cytoplasmically localized. PMID:23255126

  19. Wild-type and mutant p53 mediate cisplatin resistance through interaction and inhibition of active caspase-9

    PubMed Central

    Chee, Jacqueline L.Y.; Saidin, Suzan; Lane, David P.; Leong, Sai Mun; Noll, Jacqueline E.; Neilsen, Paul M.; Phua, Yi Ting; Gabra, Hani; Lim, Tit Meng

    2013-01-01

    The p53 gene has been implicated in many cancers due to its frequent mutations as well as mutations in other genes whose proteins directly affect p53’s functions. In addition, high expression of p53 [wild-type (WT) or mutant] has been found in the cytoplasm of many tumor cells, and studies have associated these observations with more aggressive tumors and poor prognosis. Cytoplasmic mis-localization of p53 subsequently reduced its transcriptional activity and this loss-of-function (LOF) was used to explain the lack of response to chemotherapeutic agents. However, this hypothesis seemed inadequate in explaining the apparent selection for tumor cells with high levels of p53 protein, a phenomenon that suggests a gain-of-function (GOF) of these mis-localized p53 proteins. In this study, we explored whether the direct involvement of p53 in the apoptotic response is via regulation of the caspase pathway in the cytoplasm. We demonstrate that p53, when present at high levels in the cytoplasm, has an inhibitory effect on caspase-9. Concurrently, knockdown of endogenous p53 caused an increase in the activity of caspase-9. p53 was found to interact with the p35 fragment of caspase-9, and this interaction inhibits the caspase-9 activity. In a p53-null background, the high-level expression of both exogenous WT and mutant p53 increased the resistance of these cells to cisplatin, and the data showed a correlation between high p53 expression and caspase-9 inhibition. These results suggest the inhibition of caspase-9 as a potential mechanism in evading apoptosis in tumors with high-level p53 expression that is cytoplasmically localized. PMID:23255126

  20. A sustained deficiency of mitochondrial respiratory complex III induces an apoptotic cell death through the p53-mediated inhibition of pro-survival activities of the activating transcription factor 4

    PubMed Central

    Evstafieva, A G; Garaeva, A A; Khutornenko, A A; Klepikova, A V; Logacheva, M D; Penin, A A; Novakovsky, G E; Kovaleva, I E; Chumakov, P M

    2014-01-01

    Generation of energy in mitochondria is subjected to physiological regulation at many levels, and its malfunction may result in mitochondrial diseases. Mitochondrial dysfunction is associated with different environmental influences or certain genetic conditions, and can be artificially induced by inhibitors acting at different steps of the mitochondrial electron transport chain (ETC). We found that a short-term (5 h) inhibition of ETC complex III with myxothiazol results in the phosphorylation of translation initiation factor eIF2α and upregulation of mRNA for the activating transcription factor 4 (ATF4) and several ATF4-regulated genes. The changes are characteristic for the adaptive integrated stress response (ISR), which is known to be triggered by unfolded proteins, nutrient and metabolic deficiency, and mitochondrial dysfunctions. However, after a prolonged incubation with myxothiazol (13–17 h), levels of ATF4 mRNA and ATF4-regulated transcripts were found substantially suppressed. The suppression was dependent on the p53 response, which is triggered by the impairment of the complex III-dependent de novo biosynthesis of pyrimidines by mitochondrial dihydroorotate dehydrogenase. The initial adaptive induction of ATF4/ISR acted to promote viability of cells by attenuating apoptosis. In contrast, the induction of p53 upon a sustained inhibition of ETC complex III produced a pro-apoptotic effect, which was additionally stimulated by the p53-mediated abrogation of the pro-survival activities of the ISR. Interestingly, a sustained inhibition of ETC complex I by piericidine did not induce the p53 response and stably maintained the pro-survival activation of ATF4/ISR. We conclude that a downregulation of mitochondrial ETC generally induces adaptive pro-survival responses, which are specifically abrogated by the suicidal p53 response triggered by the genetic risks of the pyrimidine nucleotide deficiency. PMID:25375376

  1. Mimulone-Induced Autophagy through p53-Mediated AMPK/mTOR Pathway Increases Caspase-Mediated Apoptotic Cell Death in A549 Human Lung Cancer Cells

    PubMed Central

    Lee, Ji-Won; Park, Mi-Hyun; Moon, Hyung-In; Park, Shin-Ji; Baik, Ji-Sue; Kim, Cheorl-Ho; Lee, Young-Choon

    2014-01-01

    Anticancer properties and mechanisms of mimulone (MML), C-geranylflavonoid isolated from the Paulownia tomentosa fruits, were firstly elucidated in this study. MML prevented cell proliferation in a dose- and time-dependent way and triggered apoptosis through the extrinsic pathway in A549 human lung adenocarcinoma cells. Furthermore, MML-treated cells displayed autophagic features, such as the formation of autophagic vacuoles, a primary morphological feature of autophagy, and the accumulation of microtubule-associated protein 1 light chain 3 (LC3) puncta, another typical maker of autophagy, as determined by FITC-conjugated immunostaining and monodansylcadaverine (MDC) staining, respectively. The expression levels of LC3-I and LC3-II, specific markers of autophagy, were also augmented by MML treatment. Autophagy inhibition by 3-methyladenine (3-MA), pharmacological autophagy inhibitor, and shRNA knockdown of Beclin-1 reduced apoptotic cell death induced by MML. Autophagic flux was not significantly affected by MML treatment and lysosomal inhibitor, chloroquine (CQ) suppressed MML-induced autophagy and apoptosis. MML-induced autophagy was promoted by decreases in p53 and p-mTOR levels and increase of p-AMPK. Moreover, inhibition of p53 transactivation by pifithrin-α (PFT-α) and knockdown of p53 enhanced induction of autophagy and finally promoted apoptotic cell death. Overall, the results demonstrate that autophagy contributes to the cytotoxicity of MML in cancer cells harboring wild-type p53. This study strongly suggests that MML is a potential candidate for an anticancer agent targeting both autophagy and apoptotic cell death in human lung cancer. Moreover, co-treatment of MML and p53 inhibitor would be more effective in human lung cancer therapy. PMID:25490748

  2. Mimulone-induced autophagy through p53-mediated AMPK/mTOR pathway increases caspase-mediated apoptotic cell death in A549 human lung cancer cells.

    PubMed

    An, Hyun-Kyu; Kim, Kyoung-Sook; Lee, Ji-Won; Park, Mi-Hyun; Moon, Hyung-In; Park, Shin-Ji; Baik, Ji-Sue; Kim, Cheorl-Ho; Lee, Young-Choon

    2014-01-01

    Anticancer properties and mechanisms of mimulone (MML), C-geranylflavonoid isolated from the Paulownia tomentosa fruits, were firstly elucidated in this study. MML prevented cell proliferation in a dose- and time-dependent way and triggered apoptosis through the extrinsic pathway in A549 human lung adenocarcinoma cells. Furthermore, MML-treated cells displayed autophagic features, such as the formation of autophagic vacuoles, a primary morphological feature of autophagy, and the accumulation of microtubule-associated protein 1 light chain 3 (LC3) puncta, another typical maker of autophagy, as determined by FITC-conjugated immunostaining and monodansylcadaverine (MDC) staining, respectively. The expression levels of LC3-I and LC3-II, specific markers of autophagy, were also augmented by MML treatment. Autophagy inhibition by 3-methyladenine (3-MA), pharmacological autophagy inhibitor, and shRNA knockdown of Beclin-1 reduced apoptotic cell death induced by MML. Autophagic flux was not significantly affected by MML treatment and lysosomal inhibitor, chloroquine (CQ) suppressed MML-induced autophagy and apoptosis. MML-induced autophagy was promoted by decreases in p53 and p-mTOR levels and increase of p-AMPK. Moreover, inhibition of p53 transactivation by pifithrin-α (PFT-α) and knockdown of p53 enhanced induction of autophagy and finally promoted apoptotic cell death. Overall, the results demonstrate that autophagy contributes to the cytotoxicity of MML in cancer cells harboring wild-type p53. This study strongly suggests that MML is a potential candidate for an anticancer agent targeting both autophagy and apoptotic cell death in human lung cancer. Moreover, co-treatment of MML and p53 inhibitor would be more effective in human lung cancer therapy. PMID:25490748

  3. AS-2, a novel inhibitor of p53-dependent apoptosis, prevents apoptotic mitochondrial dysfunction in a transcription-independent manner and protects mice from a lethal dose of ionizing radiation.

    PubMed

    Morita, Akinori; Ariyasu, Shinya; Wang, Bing; Asanuma, Tetsuo; Onoda, Takayoshi; Sawa, Akiko; Tanaka, Kaoru; Takahashi, Ippei; Togami, Shotaro; Nenoi, Mitsuru; Inaba, Toshiya; Aoki, Shin

    2014-08-01

    In a previous study, we reported that some tetradentate zinc(II) chelators inhibit p53 through the denaturation of its zinc-requiring structure but a chelator, Bispicen, a potent inhibitor of in vitro apoptosis, failed to show any efficient radioprotective effect against irradiated mice because the toxicity of the chelator to mice. The unsuitability of using tetradentate chelators as radioprotectors prompted us to undertake a more extensive search for p53-inhibiting agents that are weaker zinc(II) chelators and therefore less toxic. Here, we show that an 8-hydroxyquinoline (8HQ) derivative, AS-2, suppresses p53-dependent apoptosis through a transcription-independent mechanism. A mechanistic study using cells with different p53 characteristics revealed that the suppressive effect of AS-2 on apoptosis is specifically mediated through p53. In addition, AS-2 was less effective in preventing p53-mediated transcription-dependent events than pifithrin-μ (PFTμ), an inhibitor of transcription-independent apoptosis by p53. Fluorescence visualization of the extranuclear distribution of AS-2 also supports that it is ineffective on the transcription-dependent pathway. Further investigations revealed that AS-2 suppressed mitochondrial apoptotic events, such as the mitochondrial release of intermembrane proteins and the loss of mitochondrial membrane potential, although AS-2 resulted in an increase in the mitochondrial translocation of p53 as opposed to the decrease of cytosolic p53, and did not affect the apoptotic interaction of p53 with Bcl-2. AS-2 also protected mice that had been exposed to a lethal dose of ionizing radiation. Our findings indicate that some types of bidentate 8HQ chelators could serve as radioprotectors with no substantial toxicity in vivo. PMID:25026551

  4. p53-mediated transcriptional regulation and activation of the actin cytoskeleton regulatory RhoC to LIMK2 signaling pathway promotes cell survival

    PubMed Central

    Croft, Daniel R; Crighton, Diane; Samuel, Michael S; Lourenco, Filipe C; Munro, June; Wood, Jenifer; Bensaad, Karim; Vousden, Karen H; Sansom, Owen J; Ryan, Kevin M; Olson, Michael F

    2011-01-01

    The central arbiter of cell fate in response to DNA damage is p53, which regulates the expression of genes involved in cell cycle arrest, survival and apoptosis. Although many responses initiated by DNA damage have been characterized, the role of actin cytoskeleton regulators is largely unknown. We now show that RhoC and LIM kinase 2 (LIMK2) are direct p53 target genes induced by genotoxic agents. Although RhoC and LIMK2 have well-established roles in actin cytoskeleton regulation, our results indicate that activation of LIMK2 also has a pro-survival function following DNA damage. LIMK inhibition by siRNA-mediated knockdown or selective pharmacological blockade sensitized cells to radio- or chemotherapy, such that treatments that were sub-lethal when administered singly resulted in cell death when combined with LIMK inhibition. Our findings suggest that combining LIMK inhibitors with genotoxic therapies could be more efficacious than single-agent administration, and highlight a novel connection between actin cytoskeleton regulators and DNA damage-induced cell survival mechanisms. PMID:21079653

  5. 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

  6. p38 MAPK-induced MDM2 degradation confers paclitaxel resistance through p53-mediated regulation of EGFR in human lung cancer cells

    PubMed Central

    Park, Shin-Hyung; Seong, Myeong-A; Lee, Ho-Young

    2016-01-01

    Paclitaxel (PTX) is a chemotherapeutic agent that is used to treat a variety of cancers, including non-small cell lung cancer (NSCLC). However, the emergence of drug resistance limits the utility of PTX. This study determined the signaling pathway that contributes to PTX resistance. We first established PTX resistant cell lines (H460/R and 226B/R) using a dose-escalating maintenance of PTX. We found that p38 MAPK and epidermal growth factor receptor (EGFR) were constitutively activated in these cell lines. The inhibition of p38 MAPK activity by SB203580 treatment or the transfection of dominant-negative p38 MAPK sensitized both cell lines to PTX treatment. Erlotinib, an EGFR inhibitor, also increased PTX-induced apoptosis in PTX resistant cells, which suggests a role for p38 MAPK and EGFR in the development of PTX resistance. We demonstrated that p38 MAPK enhanced EGFR expression via the induction of the rapid degradation of mouse double-minute 2 homolog (MDM2) and the consequent stabilization of p53, a transcription factor of EGFR. These results suggest for the first time that the p38 MAPK/p53/EGFR axis is crucial for the facilitation of PTX resistance in NSCLCs. We also propose a mechanism for the role of the tumor-suppressor p53 in drug resistance. These results provide a foundation for the future development of potential therapeutic strategies to regulate the p38 MAPK/p53/EGFR pathway for the treatment of lung cancer patients with PTX resistance. PMID:26799187

  7. AS-2, a novel inhibitor of p53-dependent apoptosis, prevents apoptotic mitochondrial dysfunction in a transcription-independent manner and protects mice from a lethal dose of ionizing radiation

    SciTech Connect

    Morita, Akinori; Ariyasu, Shinya; Wang, Bing; Asanuma, Tetsuo; Onoda, Takayoshi; Sawa, Akiko; Tanaka, Kaoru; Takahashi, Ippei; Togami, Shotaro; Nenoi, Mitsuru; Inaba, Toshiya; Aoki, Shin

    2014-08-08

    Highlights: • A bidentate HQ derivative, AS-2, suppresses p53-dependent apoptosis by DNA damage. • AS-2 does not significantly affect nuclear p53 response. • UV-excited blue emission of AS-2 clearly showed its extranuclear localization. • AS-2 prevents mitochondrial dysfunction despite the increase of mitochondrial p53. • AS-2 protects mice from a radiation dose that causes lethal hematopoietic syndrome. - Abstract: In a previous study, we reported that some tetradentate zinc(II) chelators inhibit p53 through the denaturation of its zinc-requiring structure but a chelator, Bispicen, a potent inhibitor of in vitro apoptosis, failed to show any efficient radioprotective effect against irradiated mice because the toxicity of the chelator to mice. The unsuitability of using tetradentate chelators as radioprotectors prompted us to undertake a more extensive search for p53-inhibiting agents that are weaker zinc(II) chelators and therefore less toxic. Here, we show that an 8-hydroxyquinoline (8HQ) derivative, AS-2, suppresses p53-dependent apoptosis through a transcription-independent mechanism. A mechanistic study using cells with different p53 characteristics revealed that the suppressive effect of AS-2 on apoptosis is specifically mediated through p53. In addition, AS-2 was less effective in preventing p53-mediated transcription-dependent events than pifithrin-μ (PFTμ), an inhibitor of transcription-independent apoptosis by p53. Fluorescence visualization of the extranuclear distribution of AS-2 also supports that it is ineffective on the transcription-dependent pathway. Further investigations revealed that AS-2 suppressed mitochondrial apoptotic events, such as the mitochondrial release of intermembrane proteins and the loss of mitochondrial membrane potential, although AS-2 resulted in an increase in the mitochondrial translocation of p53 as opposed to the decrease of cytosolic p53, and did not affect the apoptotic interaction of p53 with Bcl-2. AS-2 also

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

    SciTech Connect

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

    2007-05-25

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

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

    PubMed Central

    Saha, Manujendra N; Jiang, Hua

    2010-01-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2013-05-23

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

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

    PubMed Central

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

    2005-01-01

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

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

    PubMed

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

    2007-08-16

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

  16. 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.

  17. Preventing retinal apoptosis--is there a common therapeutic theme?

    PubMed

    Doonan, Francesca; Groeger, Gillian; Cotter, Thomas G

    2012-07-01

    There is an urgent need for therapies for retinal diseases; retinitis pigmentosa sufferers have no treatment options available and those targeted at other retinopathies have shown limited effectiveness. The process of programmed cell death or apoptosis although complex, remains a possible target for the treatment of retinal diseases. Having identified apoptosis in the vertebrate retina in populations of immature neurons as an essential part of development it was proposed that re-activation of these developmental cell death pathways might provide insight into the death mechanisms operating in retinal diseases. However, the discovery that numerous factors initiate and mediate the apoptotic cascade in mature photoreceptors has resulted in a relatively untargeted approach to examining and arresting apoptosis in the retina. In the last 5 years, mouse models have been treated with a diverse range of drugs or factors including anti-oxidants, growth factors, steroid hormones, calcium/calpain inhibitors and tetracycline antibiotics. Therefore to draw a unifying theme from these broad research areas is challenging. However, this review focusses on two targets which are currently under investigation, reactive oxygen species and mammalian target of rapamycin, drawing together the common themes of these research areas. PMID:22366479

  18. Molecular mechanisms of nutlin-induced apoptosis in multiple myeloma: evidence for p53-transcription-dependent and -independent pathways.

    PubMed

    Saha, Manujendra N; Jiang, Hua; Chang, Hong

    2010-09-15

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

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

    SciTech Connect

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

    2014-08-15

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

  20. Neuronal gelsolin prevents apoptosis by enhancing actin depolymerization.

    PubMed

    Harms, Christoph; Bösel, Julian; Lautenschlager, Marion; Harms, Ulrike; Braun, Johann S; Hörtnagl, Heide; Dirnagl, Ulrich; Kwiatkowski, David J; Fink, Klaus; Endres, Matthias

    2004-01-01

    Gelsolin (gsn), an actin-severing protein, protects neurons from excitotoxic cell death via inactivation of membranous Ca(2+) channels. Its role during apoptotic cell death, however, has remained unclear. Using several models of neuronal cell death, we demonstrate that endogenous gelsolin has anti-apoptotic properties that correlate to its dynamic actions on the cytoskeleton. We show that neurons lacking gelsolin (gsn(-/-)) have enhanced apoptosis following exposure to staurosporine, thapsigargin, or the cholinergic toxin ethylcholine aziridinium (AF64A). AF64A-induced loss of mitochondrial membrane potential and activation of caspase-3 was specifically enhanced in gsn(-/-) neurons and could be reversed by pharmacological inhibition of mitochondrial permeability transition. Moreover, increased caspase-3 activation and cell death in AF64A-treated gsn(-/-) neurons were completely reversed by pharmacological depolymerization of actin filaments and further enhanced by their stabilization. In conclusion, actin remodeling by endogenous gelsolin or analogues protects neurons from apoptosis mediated by mitochondria and caspase-3. PMID:14962741

  1. Myc Prevents Apoptosis and Enhances Endoreduplication Induced by Paclitaxel

    PubMed Central

    Gatti, Giuliana; Maresca, Giovanna; Natoli, Manuela; Florenzano, Fulvio; Nicolin, Angelo; Felsani, Armando; D'Agnano, Igea

    2009-01-01

    Background The role of the MYC oncogene in the apoptotic pathways is not fully understood. MYC has been reported to protect cells from apoptosis activation but also to sensitize cells to apoptotic stimuli. We have previously demonstrated that the down-regulation of Myc protein activates apoptosis in melanoma cells and increases the susceptibility of cells to various antitumoral treatments. Beyond the well-known role in the G1→S transition, MYC is also involved in the G2-M cell cycle phases regulation. Methodology/Principal Findings In this study we have investigated how MYC could influence cell survival signalling during G2 and M phases. We used the microtubules damaging agent paclitaxel (PTX), to arrest the cells in the M phase, in a p53 mutated melanoma cell line with modulated Myc level and activity. An overexpression of Myc protein is able to increase endoreduplication favoring the survival of cells exposed to antimitotic poisoning. The PTX-induced endoreduplication is associated in Myc overexpressing cells with a reduced expression of MAD2, essential component of the molecular core of the spindle assembly checkpoint (SAC), indicating an impairment of this checkpoint. In addition, for the first time we have localized Myc protein at the spindle poles (centrosomes) during pro-metaphase in different cell lines. Conclusions The presence of Myc at the poles during the prometaphase could be necessary for the Myc-mediated attenuation of the SAC and the subsequent induction of endoreduplication. In addition, our data strongly suggest that the use of taxane in antitumor therapeutic strategies should be rationally based on the molecular profile of the individual tumor by specifically analyzing Myc expression levels. PMID:19421315

  2. Astragaloside IV prevents high glucose-induced podocyte apoptosis via downregulation of TRPC6.

    PubMed

    Yao, Xing-Mei; Liu, Yu-Jun; Wang, Yun-Man; Wang, Hao; Zhu, Bing-Bing; Liang, Yong-Ping; Yao, Wei-Guo; Yu, Hui; Wang, Nian-Song; Zhang, Xue-Mei; Peng, Wen

    2016-06-01

    Diabetic nephropathy (DN) is one of the most important causes of end‑stage renal disease. Astragaloside IV (AS-IV) is a saponin isolated from Astragalus membranaceus, which possesses various pharmacological activities. AS‑IV prevents podocyte apoptosis and ameliorates renal injury in DN; however, few studies have focused on its effects on ion channels. The transient receptor potential channel 6 (TRPC6) is an important Ca2+‑permeable ion channel in podocytes, which is involved in high glucose (HG)-induced podocyte apoptosis. The aim of the present study was to investigate whether AS‑IV prevented HG‑induced podocyte apoptosis via TRPC6. Cultured podocytes were pre‑treated with 10, 20 or 40 µM AS‑IV for 1 h prior to HG exposure for 24 h. Apoptosis, cell viability, expression of TRPC6, nuclear factor of activated T cells (NFAT2) and B‑cell lymphoma 2‑associated X protein (Bax), as well as the intracellular Ca2+ concentration were subsequently analyzed. The results indicated that HG induced podocyte apoptosis and upregulation of TRPC6, and increased intracellular Ca2+. Furthermore, enhanced NFAT2 and Bax expression was detected. Conversely, AS‑IV protected HG‑induced podocyte apoptosis, downregulated TRPC6 expression and suppressed intracellular Ca2+ in HG-stimulated podocytes. AS‑IV also suppressed NFAT2 and Bax expression. These results suggest that AS‑IV may prevent HG-induced podocyte apoptosis via downregulation of TRPC6, which is possibly mediated via the calcineurin/NFAT signaling pathway. PMID:27109610

  3. Novel Apoptosis Suppressor Apsup from the Baculovirus Lymantria dispar Multiple Nucleopolyhedrovirus Precludes Apoptosis by Preventing Proteolytic Processing of Initiator Caspase Dronc

    PubMed Central

    Yamada, Hayato; Kitaguchi, Koji; Hamajima, Rina; Kobayashi, Michihiro

    2013-01-01

    We previously identified a novel baculovirus-encoded apoptosis suppressor, Apsup, from the baculovirus Lymantria dispar multiple nucleopolyhedrovirus (LdMNPV). Apsup inhibits the apoptosis of L. dispar Ld652Y cells triggered by infection with p35-defective Autographa californica MNPV (vAcΔp35) and exposure to actinomycin D or UV light. Here, we examined the functional role of Apsup in apoptosis regulation in insect cells. Apsup prevented apoptosis and the proteolytic processing of L. dispar initiator caspase Dronc (Ld-Dronc) in Ld652Y cells triggered by overexpression of Ld-Dronc, LdMNPV inhibitor-of-apoptosis 3 (IAP3), or Hyphantria cunea MNPV IAP1. In vAcΔp35-infected apoptotic Ld652Y cells, Apsup restricted apoptosis induction and prevented processing of endogenous Ld-Dronc. Conversely, upon RNA interference (RNAi)-mediated silencing of apsup, LdMNPV-infected Ld652Y cells, which typically support high-titer virus replication, underwent apoptosis, accompanied by the processing of endogenous Ld-Dronc. Furthermore, endogenous Ld-Dronc coimmunoprecipitated with transiently expressed Apsup, indicating that Apsup physically interacts with Ld-Dronc. Apsup prevented the apoptosis of Sf9 cells triggered by vAcΔp35 infection but did not inhibit apoptosis or activation of caspase-3-like protease in vAcΔp35-infected Drosophila melanogaster S2 cells. Apsup also inhibited the proteolytic processing of L. dispar effector caspase Ld-caspase-1 in the transient expression assay but did not physically interact with Ld-caspase-1. These results demonstrate that Apsup inhibits apoptosis in Ld652Y cells by preventing the proteolytic processing of Ld-Dronc. Together with our previous findings showing that Apsup prevents the processing of both overexpressed Ld-Dronc and Bombyx mori Dronc, these results also demonstrate that Apsup functions as an effective apoptotic suppressor in various lepidopteran, but not dipteran, insect cells. PMID:24067961

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed Central

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

    2010-01-01

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

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

    PubMed

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

    2010-03-01

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

  8. IL-15 Prevents Apoptosis, Reverses Innate and Adaptive Immune Dysfunction, and Improves Survival in Sepsis

    PubMed Central

    Inoue, Shigeaki; Unsinger, Jacqueline; Davis, Christopher G.; Muenzer, Jared T.; Ferguson, Thomas A.; Chang, Katherine; Osborne, Dale F.; Clark, Andrew T.; Coopersmith, Craig M.; McDunn, Jonathan E.; Hotchkiss, Richard S.

    2010-01-01

    L-15 is a pluripotent antiapoptotic cytokine that signals to cells of both the innate and adaptive immune system and is regarded as a highly promising immunomodulatory agent in cancer therapy. Sepsis is a lethal condition in which apoptosis-induced depletion of immune cells and subsequent immunosuppression are thought to contribute to morbidity and mortality. This study tested the ability of IL-15 to block apoptosis, prevent immunosuppression, and improve survival in sepsis. Mice were made septic using cecal ligation and puncture or Pseudomonas aeruginosa pneumonia. The experiments comprised a 2×2 full factorial design with surgical sepsis versus sham and IL-15 versus vehicle. In addition to survival studies, splenic cellularity, canonical markers of activation and proliferation, intracellular pro- and antiapoptotic Bcl-2 family protein expression, and markers of immune cell apoptosis were evaluated by flow cytometry. Cytokine production was examined both in plasma of treated mice and splenocytes that were stimulated ex vivo. IL-15 blocked sepsis-induced apoptosis of NK cells, dendritic cells, and CD8 T cells. IL-15 also decreased sepsis-induced gut epithelial apoptosis. IL-15 therapy increased the abundance of antiapoptotic Bcl-2 while decreasing proapoptotic Bim and PUMA. IL-15 increased both circulating IFN-γ, as well as the percentage of NK cells that produced IFN-γ. Finally, IL-15 increased survival in both cecal ligation and puncture and P. aeruginosa pneumonia. In conclusion, IL-15 prevents two immunopathologic hallmarks of sepsis, namely, apoptosis and immunosuppression, and improves survival in two different models of sepsis. IL-15 represents a potentially novel therapy of this highly lethal disorder. PMID:20026737

  9. IL-15 prevents apoptosis, reverses innate and adaptive immune dysfunction, and improves survival in sepsis.

    PubMed

    Inoue, Shigeaki; Unsinger, Jacqueline; Davis, Christopher G; Muenzer, Jared T; Ferguson, Thomas A; Chang, Katherine; Osborne, Dale F; Clark, Andrew T; Coopersmith, Craig M; McDunn, Jonathan E; Hotchkiss, Richard S

    2010-02-01

    IL-15 is a pluripotent antiapoptotic cytokine that signals to cells of both the innate and adaptive immune system and is regarded as a highly promising immunomodulatory agent in cancer therapy. Sepsis is a lethal condition in which apoptosis-induced depletion of immune cells and subsequent immunosuppression are thought to contribute to morbidity and mortality. This study tested the ability of IL-15 to block apoptosis, prevent immunosuppression, and improve survival in sepsis. Mice were made septic using cecal ligation and puncture or Pseudomonas aeruginosa pneumonia. The experiments comprised a 2 x 2 full factorial design with surgical sepsis versus sham and IL-15 versus vehicle. In addition to survival studies, splenic cellularity, canonical markers of activation and proliferation, intracellular pro- and antiapoptotic Bcl-2 family protein expression, and markers of immune cell apoptosis were evaluated by flow cytometry. Cytokine production was examined both in plasma of treated mice and splenocytes that were stimulated ex vivo. IL-15 blocked sepsis-induced apoptosis of NK cells, dendritic cells, and CD8 T cells. IL-15 also decreased sepsis-induced gut epithelial apoptosis. IL-15 therapy increased the abundance of antiapoptotic Bcl-2 while decreasing proapoptotic Bim and PUMA. IL-15 increased both circulating IFN-gamma, as well as the percentage of NK cells that produced IFN-gamma. Finally, IL-15 increased survival in both cecal ligation and puncture and P. aeruginosa pneumonia. In conclusion, IL-15 prevents two immunopathologic hallmarks of sepsis, namely, apoptosis and immunosuppression, and improves survival in two different models of sepsis. IL-15 represents a potentially novel therapy of this highly lethal disorder. PMID:20026737

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

    PubMed Central

    Bhattacharjee, Rajesh; Xiang, Wenpei; Wang, Yinna; Zhang, Xiaoying; Billiar, Timothy R.

    2013-01-01

    Tumor necrosis factor α (TNF) is a pleiotropic proinflammatory cytokine that plays a role in immunity and the control of cell proliferation, cell differentiation, and apoptosis. The pleiotropic nature of TNF is due to the formation of different signaling complexes upon the binding of TNF to its receptor, TNF receptor type 1 (TNFR1). TNF induces apoptosis in various mammalian cells when the cells are co-treated with a transcription inhibitor like actinomycin D (ActD). When TNFR1 is activated, it recruits an adaptor protein, TNF receptor-associated protein with death domain (TRADD), through its cytoplasmic death effector domain (DED). TRADD, in turn, recruits other signaling proteins, including TNF receptor-associated protein 2 (TRAF2) and receptor-associated protein kinase (RIPK) 1, to form a complex. Subsequently, this complex combines with FADD and procaspase-8, converts into a death-inducing signaling complex (DISC) to induce apoptosis. Cyclic AMP (cAMP) is a second messenger that regulates various cellular processes such as cell proliferation, gene expression, and apoptosis. cAMP analogues are reported to act as anti-apoptotic agents in various cell types, including hepatocytes. We found that a cAMP analogue, dibutyryl cAMP (db-cAMP), inhibits TNF + ActD-induced apoptosis in rat hepatocytes. The protein kinase A (PKA) inhibitor KT-5720 reverses this inhibitory effect of cAMP on apoptosis. Cytoprotection by cAMP involves down-regulation of various apoptotic signal regulators like TRADD and FADD and inhibition of caspase-8 and caspase-3 cleavage. We also found that cAMP exerts its affect at the proximal level of TNF signaling by inhibiting the formation of the DISC complex upon the binding of TNF to TNFR1. In conclusion, our study shows that cAMP prevents TNF + ActD-induced apoptosis in rat hepatocytes by inhibiting DISC complex formation. PMID:22634003

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed Central

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

    2007-01-01

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

  13. Long story short: p53 mediates innate immunity.

    PubMed

    Miciak, Jessica; Bunz, Fred

    2016-04-01

    The story of p53 and how we came to understand it is punctuated by fundamental insights into the essence of cancer. In the decades since its discovery, p53 has been shown to be centrally involved in most, if not all, of the cellular processes that maintain tissue homeostasis. Extensive functional analyses of p53 and its tumor-associated mutants have illuminated many of the common defects shared by most cancer cells. As the central character in a tale that continues to unfold, p53 has become increasingly familiar and yet remains surprisingly inscrutable. New relationships periodically come to light, and surprising, novel activities continue to emerge, thereby revealing new dimensions and aspects of its function. What lies at the very core of this complex protagonist? What is its prime motivation? As every avid reader knows, the elements of character are profoundly shaped by adversity--originating from within and without. And so it is with p53. This review will briefly recap the coordinated responses of p53 to viral infection, and outline a hypothetical model that would explain how an abundance of seemingly unrelated phenotypic attributes may in the end reflect a singular function. All stories eventually draw to a conclusion. This epic tale may eventually leave us with the realization that p53, most simply described, is a protein that evolved to mediate immune surveillance. PMID:26951863

  14. Skeletal muscle secreted factors prevent glucocorticoid-induced osteocyte apoptosis through activation of β-catenin.

    PubMed

    Jähn, K; Lara-Castillo, N; Brotto, L; Mo, C L; Johnson, M L; Brotto, M; Bonewald, L F

    2012-01-01

    It is a widely held belief that the sole effect of muscle on bone is through mechanical loading. However, as the two tissues are intimately associated, we hypothesized that muscle myokines may have positive effects on bone. We found that factors produced by muscle will protect osteocytes from undergoing cell death induced by dexamethasone (dex), a glucocorticoid known to induce osteocyte apoptosis thereby compromising their capacity to regulate bone remodeling. Both the trypan blue exclusion assay for cell death and nuclear fragmentation assay for apoptosis were used. MLO-Y4 osteocytes, primary osteocytes, and MC3T3 osteoblastic cells were protected against dex-induced apoptosis by C2C12 myotube conditioned media (MT-CM) or by CM from ex vivo electrically stimulated, intact extensor digitorum longus (EDL) or soleus muscle derived from 4 month-old mice. C2C12 MT-CM, but not undifferentiated myoblast CM prevented dex-induced cell apoptosis and was potent down to 0.1 % CM. The CM from EDL muscle electrically stimulated tetanically at 80 Hz was more potent (10 fold) in prevention of dex-induced osteocyte death than CM from soleus muscle stimulated at the same frequency or CM from EDL stimulated at 1 Hz. This suggests that electrical stimulation increases production of factors that preserve osteocyte viability and that type II fibers are greater producers than type I fibers. The muscle factor(s) appears to protect osteocytes from cell death through activation of the Wnt/β-catenin pathway, as MT-CM induces β-catenin nuclear translocation and β-catenin siRNA abrogated the positive effects of MT-CM on dex-induced apoptosis. We conclude that muscle cells naturally secrete factor(s) that preserve osteocyte viability. PMID:22972510

  15. Vascular Endothelial Growth Factor Prevents Apoptosis and Preserves Contractile Function in Hypertrophied Infant Heart

    PubMed Central

    Friehs, Ingeborg; Barillas, Rodrigo; Vasilyev, Nikolay V.; Roy, Nathalie; McGowan, Francis X.; del Nido, Pedro J.

    2012-01-01

    Background Cardiac hypertrophy is an adaptive response to increased workload that, if unrelieved, leads to heart failure. It has been reported that cardiomyocyte apoptosis contributes to failure, and that vascular endothelial growth factor (VEGF) treatment of hypertrophied myocardium increases capillary density and improves myocardial perfusion. In this study we hypothesized that VEGF treatment reduces cardiomyocyte apoptosis and thereby preserves myocardial contractile function. Methods and Results Newborn rabbits underwent aortic banding. At 4 and 6 weeks of age, hypertrophied animals were treated with intrapericardial administration of recombinant VEGF protein. Three groups of animals were investigated: age-matched controls (C), untreated hypertrophied (H), and VEGF-treated hypertrophied hearts (T). Cardiomyocyte apoptosis was determined by TUNEL staining and PARP cleavage (immunoblotting of nuclear extracts) and cardiac function by transthoracic echocardiography. Death attributable to severe heart failure occurred in 14 of 43 untreated and 2 of 29 VEGF-treated animals (P<0.01). TUNEL-positive cardiomyocyte nuclei (n/1000 nuclei) were significantly increased in untreated hearts at 5 weeks (H: 10±1.8 versus T: 3±0.7) and at 7 weeks (H: 13±3.6 versus T: 5±1.5; P<0.05). Increased apoptosis in untreated hypertrophy was also confirmed by the presence of PARP cleavage (H: 74±7 versus T: 41±4 arbitrary densitometry units; P<0.05). VEGF treatment preserved left ventricular mass, prevented dilation (T: 1.01±0.06 versus H: 0.77±0.07; P<0.05), and preserved contractility indices compared with untreated hearts. Conclusions Lack of adaptive capillary growth impairs myocardial perfusion and substrate delivery in hypertrophying myocardium. VEGF treatment reduces myocardial apoptosis and prolongs survival in a model of severe progressive left ventricular hypertrophy. Promoting capillary growth with VEGF reduces apoptosis, preserves myocardial contractile function, and

  16. Prevention of lymphocyte apoptosis in septic mice with cancer increases mortality

    PubMed Central

    Fox, Amy C.; Breed, Elise R; Liang, Zhe; Clark, Andrew T.; Zee-Cheng, Brendan R.; Chang, Katherine C.; Dominguez, Jessica A.; Jung, Enjae; Dunne, W. Michael; Burd, Eileen M.; Farris, Alton B.; Linehan, David C.; Coopersmith, Craig M.

    2011-01-01

    Lymphocyte apoptosis is thought to play a major role in the pathophysiology of sepsis. However, there is a disconnect between animal models of sepsis and patients with the disease, since the former use subjects that were healthy prior to the onset of infection while most patients have underlying comorbidities. The purpose of this study was to determine whether lymphocyte apoptosis prevention is effective in preventing mortality in septic mice with pre-existing cancer. Mice with lymphocyte Bcl-2 overexpression (Bcl-2-Ig) and wild type (WT) mice were injected with a transplantable pancreatic adenocarcinoma cell line. Three weeks later after development of palpable tumors, all animals received an intratracheal injection of Pseudomonas aeruginosa. Despite having decreased sepsis-induced T and B lymphocyte apoptosis, Bcl-2-Ig mice had markedly increased mortality compared to WT mice following Pseudomonas aeruginosa pneumonia (85% vs. 44% seven-day mortality, p=0.004). The worsened survival in Bcl-2-Ig mice was associated with increases in Th1 cytokines TNF-α and IFN-γ in bronchoalveolar lavage fluid and decreased production of the Th2 cytokine IL-10 in stimulated splenocytes. There were no differences in tumor size or pulmonary pathology between Bcl-2-Ig and WT mice. To verify the mortality difference was not specific to Bcl-2 overexpression, similar experiments were performed in Bim-/- mice. Septic Bim-/- mice with cancer also had increased mortality compared to septic WT mice with cancer. These data demonstrate that despite overwhelming evidence that prevention of lymphocyte apoptosis is beneficial in septic hosts without comorbidities, the same strategy worsens survival in mice with cancer that are given pneumonia. PMID:21734077

  17. Prevention of lymphocyte apoptosis in septic mice with cancer increases mortality.

    PubMed

    Fox, Amy C; Breed, Elise R; Liang, Zhe; Clark, Andrew T; Zee-Cheng, Brendan R; Chang, Katherine C; Dominguez, Jessica A; Jung, Enjae; Dunne, W Michael; Burd, Eileen M; Farris, Alton B; Linehan, David C; Coopersmith, Craig M

    2011-08-15

    Lymphocyte apoptosis is thought to have a major role in the pathophysiology of sepsis. However, there is a disconnect between animal models of sepsis and patients with the disease, because the former use subjects that were healthy prior to the onset of infection while most patients have underlying comorbidities. The purpose of this study was to determine whether lymphocyte apoptosis prevention is effective in preventing mortality in septic mice with preexisting cancer. Mice with lymphocyte Bcl-2 overexpression (Bcl-2-Ig) and wild type (WT) mice were injected with a transplantable pancreatic adenocarcinoma cell line. Three weeks later, after development of palpable tumors, all animals received an intratracheal injection of Pseudomonas aeruginosa. Despite having decreased sepsis-induced T and B lymphocyte apoptosis, Bcl-2-Ig mice had markedly increased mortality compared with WT mice following P. aeruginosa pneumonia (85 versus 44% 7-d mortality; p = 0.004). The worsened survival in Bcl-2-Ig mice was associated with increases in Th1 cytokines TNF-α and IFN-γ in bronchoalveolar lavage fluid and decreased production of the Th2 cytokine IL-10 in stimulated splenocytes. There were no differences in tumor size or pulmonary pathology between Bcl-2-Ig and WT mice. To verify that the mortality difference was not specific to Bcl-2 overexpression, similar experiments were performed in Bim(-/-) mice. Septic Bim(-/-) mice with cancer also had increased mortality compared with septic WT mice with cancer. These data demonstrate that, despite overwhelming evidence that prevention of lymphocyte apoptosis is beneficial in septic hosts without comorbidities, the same strategy worsens survival in mice with cancer that are given pneumonia. PMID:21734077

  18. Tamoxifen prevents apoptosis and follicle loss from cyclophosphamide in cultured rat ovaries.

    PubMed

    Piasecka-Srader, Joanna; Blanco, Fernando F; Delman, Devora H; Dixon, Dan A; Geiser, James L; Ciereszko, Renata E; Petroff, Brian K

    2015-05-01

    Recent studies documented that the selective estrogen receptor modulator tamoxifen prevents follicle loss and promotes fertility following in vivo exposure of rodents to irradiation or ovotoxic cancer drugs, cyclophosphamide and doxorubicin. In an effort to characterize the ovarian-sparing mechanisms of tamoxifen in preantral follicle classes, cultured neonatal rat ovaries (Day 4, Sprague Dawley) were treated for 1-7 days with active metabolites of cyclophosphamide (i.e., 4-hydroxycyclophosphamide; CTX) (0, 1, and 10 μM) and tamoxifen (i.e., 4-hydroxytamoxifen; TAM) (0 and 10 μM) in vitro, and both apoptosis and follicle numbers were measured. CTX caused marked follicular apoptosis and follicular loss. TAM treatment decreased follicular loss and apoptosis from CTX in vitro. TAM alone had no effect on these parameters. IGF-1 and IGF-1 receptor were assessed in ovarian tissue showing no impact of TAM or CTX on these endpoints. Targeted mRNA analysis during follicular rescue by TAM revealed decreased expression of multiple genes related to inflammation, including mediators of lipoxygenase and prostaglandin production and signaling (Alox5, Pla2g1b, Ptgfr), cytokine binding (Il1r1, Il2rg ), apoptosis (Tnfrsf1a), second messenger signaling (Mapk1, Mapk14, Plcg1), as well as tissue remodeling and vasodilation (Bdkrb2, Klk15). The results suggest that TAM protects the ovary from CTX-mediated toxicity through direct ovarian actions that oppose follicular loss. PMID:25833159

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

    SciTech Connect

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

    2006-04-14

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

  20. PD150606 protects against ischemia/reperfusion injury by preventing μ-calpain-induced mitochondrial apoptosis.

    PubMed

    Luo, Tao; Yue, Rongchuan; Hu, Houxiang; Zhou, Zhou; Yiu, Kai Hang; Zhang, Shuang; Xu, Lei; Li, Ke; Yu, Zhengping

    2015-11-15

    Calpain plays an important role in myocardial ischemia/reperfusion (I/R) injury. PD150606, a nonpeptide, cell-permeable and noncompetitive calpain inhibitor, has been shown to have protective properties in ischemic disease. The aims of the present study were to investigate whether PD150606 could alleviate myocardial I/R injury and to examine the possible mechanisms involved. The I/R model was established in vivo in C57BL/6 mice and in vitro using neonatal mouse cardiomyocytes, respectively. To evaluate the protective effects of PD150606 on I/R injury, we measured the myocardial infarct area, apoptosis, and expression of cleaved caspase-3. We also investigated the underlying mechanisms by examining mitochondrial function as reflected by the ATP concentration, translocation of cytochrome c, dynamics of mPTP opening, and membrane potential (ΔΨm), coupled with calpain activity. Pretreatment with PD150606 significantly reduced the infarct area and apoptosis caused by I/R. PD150606 pretreatment also reduced mitochondrial dysfunction by inhibiting calpain activation. Moreover, we found that μ-calpain is the main contributor to I/R-induced calpain activation. Knockdown of μ-calpain with siRNA significantly reversed calpain activation, mitochondrial dysfunction, and cardiomyocyte apoptosis caused by I/R in vitro. Our results suggest that PD150606 may protect against I/R injury via preventing μ-calpain-induced mitochondrial apoptosis. PMID:26091952

  1. Phycocyanin prevents methylglyoxal-induced mitochondrial-dependent apoptosis in INS-1 cells by Nrf2.

    PubMed

    Gao, Yingnv; Liu, Chen; Wan, Guoqing; Wang, Xinshuo; Cheng, Xiaodong; Ou, Yu

    2016-02-01

    Methylglyoxal (MG) is a reactive dicarbonyl compound, whose abnormal accumulation in diabetic patients exerts deleterious effects on cells and tissues. The β-cell is the main target cell of Type 2 diabetes, and its insulin secretion injury and cell apoptosis can be due to mitochondrial dysfunction. Previous studies have demonstrated MG induced β-cell apoptosis. However, little is known about the effect of MG on β-cell mitochondrial dysfunction. Phycocyanin (PC) has been demonstrated to possess various biological activities including the effects on diabetic models in vivo. The aim of this study was to determine the protective effect of PC against methylglyoxal (MG)-induced dysfunction in pancreatic β-cell INS-1 and also the mechanism. We demonstrated that MG induced mitochondrial dysfunction by the decline in ATP levels, and the increase of the level of intracellular reactive oxygen species (ROS). Furthermore, MG released cytochrome c and apoptosis-inducing factor (AIF) from the mitochondrion, induced changes in the expression of Bcl-2 family members, activated caspases and increased PARP cleavage. Interestingly, PC activated nuclear erythroid-related factor 2 (Nrf2), and Nrf2 activation as well as antioxidant enzymes HO-1 and glyoxalase 1 (Glo-1) were confirmed to be involved in the mechanisms underlying the protection of PC by RNA interference. Altogether, these results demonstrated that PC prevented mitochondrial-dependent apoptosis in MG-induced INS-1 cells and the effect was associated with Nrf2 activation. PMID:26805012

  2. Tamoxifen Prevents Apoptosis and Follicle Loss from Cyclophosphamide in Cultured Rat Ovaries1

    PubMed Central

    Piasecka-Srader, Joanna; Blanco, Fernando F.; Delman, Devora H.; Dixon, Dan A.; Geiser, James L.; Ciereszko, Renata E.; Petroff, Brian K.

    2015-01-01

    Recent studies documented that the selective estrogen receptor modulator tamoxifen prevents follicle loss and promotes fertility following in vivo exposure of rodents to irradiation or ovotoxic cancer drugs, cyclophosphamide and doxorubicin. In an effort to characterize the ovarian-sparing mechanisms of tamoxifen in preantral follicle classes, cultured neonatal rat ovaries (Day 4, Sprague Dawley) were treated for 1–7 days with active metabolites of cyclophosphamide (i.e., 4-hydroxycyclophosphamide; CTX) (0, 1, and 10 μM) and tamoxifen (i.e., 4-hydroxytamoxifen; TAM) (0 and 10 μM) in vitro, and both apoptosis and follicle numbers were measured. CTX caused marked follicular apoptosis and follicular loss. TAM treatment decreased follicular loss and apoptosis from CTX in vitro. TAM alone had no effect on these parameters. IGF-1 and IGF-1 receptor were assessed in ovarian tissue showing no impact of TAM or CTX on these endpoints. Targeted mRNA analysis during follicular rescue by TAM revealed decreased expression of multiple genes related to inflammation, including mediators of lipoxygenase and prostaglandin production and signaling (Alox5, Pla2g1b, Ptgfr), cytokine binding (Il1r1, Il2rg ), apoptosis (Tnfrsf1a), second messenger signaling (Mapk1, Mapk14, Plcg1), as well as tissue remodeling and vasodilation (Bdkrb2, Klk15). The results suggest that TAM protects the ovary from CTX-mediated toxicity through direct ovarian actions that oppose follicular loss. PMID:25833159

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

    SciTech Connect

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

    2012-06-22

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

  4. Cutaneous HPV23 E6 prevents p53 phosphorylation through interaction with HIPK2.

    PubMed

    Muschik, Dorothea; Braspenning-Wesch, Ilona; Stockfleth, Eggert; Rösl, Frank; Hofmann, Thomas G; Nindl, Ingo

    2011-01-01

    Ultraviolet irradiation (UV) is the major risk factor for the development of skin cancer. Moreover, increasing evidence suggests cutaneotropic human papillomaviruses (HPV) from the beta genus to play a causal role as a co-factor in the development of cutaneous squamous cell carcinoma. Homeodomain-interacting protein kinase 2 (HIPK2) operates as a potential suppressor in skin tumorigenesis and is stabilized by UV-damage. HIPK2 is an important regulator of apoptosis, which forms a complex with the tumor suppressor p53, mediating p53 phosphorylation at Ser 46 and thus promoting pro-apoptotic gene expression. In our study, we demonstrate that cutaneous HPV23 E6 protein directly targets HIPK2 function. Accordingly, HPV23 E6 interacts with HIPK2 both in vitro and in vivo. Furthermore, upon massive UVB-damage HPV23 E6 co-localizes with endogenous HIPK2 at nuclear bodies. Functionally, we demonstrate that HPV23 E6 inhibits HIPK2-mediated p53 Ser 46 phosphorylation through enforcing dissociation of the HIPK2/p53 complex. In addition, HPV23 E6 co-accumulates with endogenous HIPK2 upon UV damage suggesting a mechanism by which HPV23 E6 keeps HIPK2 in check after UV damage. Thus, cutaneous HPV23 E6 prevents HIPK2-mediated p53 Ser 46 phosphorylation, which may favour survival of UV-damaged keratinocytes and skin carcinogenesis by apoptosis evasion. PMID:22110707

  5. Role of lubricin and boundary lubrication in the prevention of chondrocyte apoptosis.

    PubMed

    Waller, Kimberly A; Zhang, Ling X; Elsaid, Khaled A; Fleming, Braden C; Warman, Matthew L; Jay, Gregory D

    2013-04-01

    Osteoarthritis is a complex disease involving the mechanical breakdown of articular cartilage in the presence of altered joint mechanics and chondrocyte death, but the connection between these factors is not well established. Lubricin, a mucinous glycoprotein encoded by the PRG4 gene, provides boundary lubrication in articular joints. Joint friction is elevated and accompanied by accelerated cartilage damage in humans and mice that have genetic deficiency of lubricin. Here, we investigated the relationship between coefficient of friction and chondrocyte death using ex vivo and in vitro measurements of friction and apoptosis. We observed increases in whole-joint friction and cellular apoptosis in lubricin knockout mice compared with wild-type mice. When we used an in vitro bovine explant cartilage-on-cartilage bearing system, we observed a direct correlation between coefficient of friction and chondrocyte apoptosis in the superficial layers of cartilage. In the bovine explant system, the addition of lubricin as a test lubricant significantly lowered the static coefficient of friction and number of apoptotic chondrocytes. These results demonstrate a direct connection between lubricin, boundary lubrication, and cell survival and suggest that supplementation of synovial fluid with lubricin may be an effective treatment to prevent cartilage deterioration in patients with genetic or acquired deficiency of lubricin. PMID:23530215

  6. Subclinical concentrations of sevoflurane reduce oxidative stress but do not prevent hippocampal apoptosis

    PubMed Central

    ZHOU, ZHI-BIN; YANG, XIAO-YU; TANG, YING; ZHOU, XUE; ZHOU, LI-HUA; FENG, XIA

    2016-01-01

    Sevoflurane is generally considered a pro-apoptotic agent in the neonatal brain. However, recent studies have suggested that low levels of sevoflurane anesthesia may be neuroprotective and have a memory enhancing effect. The present study aimed to investigate whether sevoflurane exerts a neuroprotective effect at subclinical concentrations, with regard to oxidative state. In the current study, postnatal day 7 (P7) Sprague-Dawley rats were continuously exposed to 0.3, 1.3, or 2.3% sevoflurane for 6 h. ELISA was used to quantify the levels of superoxide dismutase, glutathione peroxidase (GSH-px) and malondialdehyde (MDA) in the plasma and the hippocampus. Terminal deoxynucleotidyl-transferase dUTP nick-end labeling staining was used to observe hippocampal neuronal apoptosis. Altered object exploration tests for recognition memory were employed to investigate long-term behavioral effects at postnatal day 28. The results demonstrated that a single 6 h exposure to a subclinical concentration (1.3%) of sevoflurane at P7 reduces MDA and GPH-px production in rats. Sevoflurane induced hippocampal apoptosis in a dose-dependent manner and altered recognition memory testing indicated no differences among the groups. Although early exposure to a subclinical concentration of sevoflurane reduced oxidative stress, it did not prevent the process of sevoflurane-induced hippocampal apoptosis. These changes did not affect subsequent recognition memory in juvenile rats. PMID:27222114

  7. Subclinical concentrations of sevoflurane reduce oxidative stress but do not prevent hippocampal apoptosis.

    PubMed

    Zhou, Zhi-Bin; Yang, Xiao-Yu; Tang, Ying; Zhou, Xue; Zhou, Li-Hua; Feng, Xia

    2016-07-01

    Sevoflurane is generally considered a pro-apoptotic agent in the neonatal brain. However, recent studies have suggested that low levels of sevoflurane anesthesia may be neuroprotective and have a memory enhancing effect. The present study aimed to investigate whether sevoflurane exerts a neuroprotective effect at subclinical concentrations, with regard to oxidative state. In the current study, postnatal day 7 (P7) Sprague‑Dawley rats were continuously exposed to 0.3, 1.3, or 2.3% sevoflurane for 6 h. ELISA was used to quantify the levels of superoxide dismutase, glutathione peroxidase (GSH‑px) and malondialdehyde (MDA) in the plasma and the hippocampus. Terminal deoxynucleotidyl-transferase dUTP nick-end labeling staining was used to observe hippocampal neuronal apoptosis. Altered object exploration tests for recognition memory were employed to investigate long‑term behavioral effects at postnatal day 28. The results demonstrated that a single 6 h exposure to a subclinical concentration (1.3%) of sevoflurane at P7 reduces MDA and GPH‑px production in rats. Sevoflurane induced hippocampal apoptosis in a dose‑dependent manner and altered recognition memory testing indicated no differences among the groups. Although early exposure to a subclinical concentration of sevoflurane reduced oxidative stress, it did not prevent the process of sevoflurane-induced hippocampal apoptosis. These changes did not affect subsequent recognition memory in juvenile rats. PMID:27222114

  8. Proteasome inhibitors prevent cytochrome c release during apoptosis but not in excitotoxic death of cerebellar granule neurons.

    PubMed

    Bobba, Antonella; Canu, Nadia; Atlante, Anna; Petragallo, Vito; Calissano, Pietro; Marra, Ersilia

    2002-03-27

    In order to find out whether and how proteasomes participate in the processes leading cerebellar granule cells to death either in necrosis, due to glutamate neurotoxicity, or in apoptosis, due to K(+) shift, we measured the three proteasome activities by using specific fluorescent probes and investigated the effect of several proteasome inhibitors, including MG132, on the cytochrome c release taking place in the early phase of both apoptosis and necrosis. We show that differently from apoptosis, the early phase of necrosis does not require proteasome activation. Inhibition of proteasome activity can prevent cytochrome c release in cerebellar granule cells undergoing apoptosis, thus improving cell survival, but not necrosis. These findings show that proteasomes play an important role in the early phase of apoptosis but not that of necrosis, and that these two types of cell death differ from each other in their mechanism of cytochrome c release. PMID:11943185

  9. Modulatory Effects of Polyphenols on Apoptosis Induction: Relevance for Cancer Prevention

    PubMed Central

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

    2008-01-01

    Polyphenols, occurring in fruit and vegetables, wine, tea, extra virgin olive oil, chocolate and other cocoa products, have been demonstrated to have clear antioxidant properties in vitro, and many of their biological actions have been attributed to their intrinsic reducing capabilities. However, it has become clear that, in complex biological systems, polyphenols exhibit several additional properties which are yet poorly understood. Apoptosis is a genetically controlled and evolutionarily conserved form of cell death of critical importance for the normal embryonic development and for the maintenance of tissue homeostasis in the adult organism. The malfunction of the death machinery may play a primary role in various pathological processes, since too little or too much apoptosis can lead to proliferative or degenerative diseases, respectively. Cancer cells are characterized by a deregulated proliferation, and/or an inability to undergo programmed cell death. A large body of evidence indicates that polyphenols can exert chemopreventive effects towards different organ specific cancers, affecting the overall process of carcinogenesis by several mechanisms: inhibition of DNA synthesis, modulation of ROS production, regulation of cell cycle arrest, modulation of survival/proliferation pathways. In addition, polyphenols can directly influence different points of the apoptotic process, and/or the expression of regulatory proteins. Although the bulk of data has been obtained in in vitro systems, a number of clinical studies suggesting a preventive and therapeutic effectiveness of polyphenols in vivo is available. However, a deeper knowledge of the underlying mechanisms responsible for the modulation of apoptosis by polyphenols, and their real effectiveness, is necessary in order to propose them as potential chemopreventive and chemotherapeutic candidates for cancer treatment. PMID:19325744

  10. Modulatory effects of polyphenols on apoptosis induction: relevance for cancer prevention.

    PubMed

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

    2008-03-01

    Polyphenols, occurring in fruit and vegetables, wine, tea, extra virgin olive oil, chocolate and other cocoa products, have been demonstrated to have clear antioxidant properties in vitro, and many of their biological actions have been attributed to their intrinsic reducing capabilities. However, it has become clear that, in complex biological systems, polyphenols exhibit several additional properties which are yet poorly understood. Apoptosis is a genetically controlled and evolutionarily conserved form of cell death of critical importance for the normal embryonic development and for the maintenance of tissue homeostasis in the adult organism. The malfunction of the death machinery may play a primary role in various pathological processes, since too little or too much apoptosis can lead to proliferative or degenerative diseases, respectively. Cancer cells are characterized by a deregulated proliferation, and/or an inability to undergo programmed cell death. A large body of evidence indicates that polyphenols can exert chemopreventive effects towards different organ specific cancers, affecting the overall process of carcinogenesis by several mechanisms: inhibition of DNA synthesis, modulation of ROS production, regulation of cell cycle arrest, modulation of survival/proliferation pathways. In addition, polyphenols can directly influence different points of the apoptotic process, and/or the expression of regulatory proteins. Although the bulk of data has been obtained in in vitro systems, a number of clinical studies suggesting a preventive and therapeutic effectiveness of polyphenols in vivo is available. However, a deeper knowledge of the underlying mechanisms responsible for the modulation of apoptosis by polyphenols, and their real effectiveness, is necessary in order to propose them as potential chemopreventive and chemotherapeutic candidates for cancer treatment. PMID:19325744

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

    PubMed

    Liu, Zhi-Feng; Zheng, Dong; Fan, Guo-Chang; Peng, Tianqing; Su, Lei

    2016-08-01

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

  12. Hydroxycamptothecin induces apoptosis of fibroblasts and prevents intraarticular scar adhesion in rabbits by activating the IRE-1 signal pathway.

    PubMed

    Li, Xiaolei; Sun, Yu; Chen, Hui; Zhu, Gengyao; Liang, Yuan; Wang, Qiang; Wang, Jingcheng; Yan, Lianqi

    2016-06-15

    Hydroxycamptothecin (HCPT) has been proven to prevent intraarticular scar adhesion, but the mechanism is still unclear. ER stress is known to participate in many diseases, and the IRE-1 signal pathway has been reported in fibrotic diseases. The aim of this study was to illustrate the mechanism of HCPT-induced apoptosis in fibroblasts and the prevention of intraarticular scar adhesion. The effects of HCPT on fibroblasts were determined by CCK-8 assay, Hoechst staining and Western blot. The effect of HCPT on intraarticular scar adhesion was detected by macroscopic evaluation, hydroxyproline content, histological evaluation, fibroblast counting and immunohistochemical analysis. HCPT induced apoptosis of fibroblasts, according to CCK-8 assays, Hoechst staining and Western blot analysis. As the concentration of HCPT increased, the expressions of glucose-regulated protein 78 (GRP78), inositol-requiring kinase1 (IRE-1), C/EBP homologous protein (CHOP) and Bax were all increased, but the expression of Bcl-2 was decreased. Knockdown of IRE-1 alleviated the HCPT-induced apoptosis in our fibroblast model. HCPT could prevent intraarticular scar adhesion, according to the results of macroscopic evaluation, hydroxyproline content, histological evaluation and fibroblast counting in a rabbit model. Immunohistochemical analysis showed that IRE-1 expression increased as the concentration increased. The present study showed that the IRE-1 signal pathway might be involved in HCPT-induced apoptosis of fibroblast and might play a role in preventing intraarticular scar adhesion. PMID:27068147

  13. Silencing of the polyamine catabolic key enzyme SSAT prevents CDK inhibitor-induced apoptosis in Caco-2 colon cancer cells.

    PubMed

    Çoker, A; Arısan, E D; Palavan-Ünsal, N

    2012-04-01

    Roscovitine and purvalanol are purine derivative cyclin-dependent kinase (CDK) inhibitors that induce apoptosis in various types of cancer cells. However, their impact on the apoptotic cell death mechanism requires further elucidation. Natural polyamines putrescine, spermidine and spermine play essential roles in the regulation of cell growth and proliferation. Increased levels of polyamines in cells are considered to be involved in cancer progression. Intracellular polyamine levels are under the control of several catabolic enzymes, such as spermidine/spermine-N-acetyl transferase (SSAT), acetylpolyamine oxidase (APAO) and spermine oxidase (SMO), which could be altered by several therapeutic drugs. However, the possible role of polyamines in drug-induced apoptosis has yet to be clarified. In the present study, our aim was to determine the modulation of the polyamine catabolic pathway related to CDK inhibitor-induced apoptosis in Caco-2 cells. We found that roscovitine and purvalanol (each 20 µM) induced apoptosis by activating caspase-9 and -3, and inhibiting the mitochondrial membrane potential in Caco-2 cells. CDK inhibitors decreased the intracellular putrescine and spermine levels without affecting spermidine levels. Although both roscovitine and purvalanol induced SSAT expression, they did not exert a significant effect on the APAO expression profile. SSAT transient silencing prevented roscovitine-induced apoptosis compared to parental cells. Thus, we concluded that roscovitine and purvalanol significantly induce apoptosis in Caco-2 cells by modulating the polyamine catabolism, and that SSAT could be an important target in evaluating the potential role of polyamines in apoptotic cell death. PMID:22294330

  14. Leishmania donovani Exploits Myeloid Cell Leukemia 1 (MCL-1) Protein to Prevent Mitochondria-dependent Host Cell Apoptosis.

    PubMed

    Giri, Jayeeta; Srivastav, Supriya; Basu, Moumita; Palit, Shreyasi; Gupta, Purnima; Ukil, Anindita

    2016-02-12

    Apoptosis is one of the mechanisms used by host cells to remove unwanted intracellular organisms, and often found to be subverted by pathogens through use of host anti-apoptotic proteins. In the present study, with the help of in vitro and in vivo approaches, we documented that the macrophage anti-apoptotic protein myeloid cell leukemia 1 (MCL-1) is exploited by the intra-macrophage parasite Leishmania donovani to protect their "home" from actinomycin D-induced mitochondria-dependent apoptosis. Among all the anti-apoptotic BCL-2 family members, infection preferentially up-regulated expression of MCL-1 at both the mRNA and protein levels and compared with infected control, MCL-1-silenced infected macrophages documented enhanced caspase activity and increased apoptosis when subjected to actinomycin D treatment. Phosphorylation kinetics and ChIP assay demonstrated that infection-induced MCL-1 expression was regulated by transcription factor CREB (cAMP-response element-binding protein) and silencing of CREB resulted in reduced expression of MCL-1 and increased apoptosis. During infection, MCL-1 was found to be localized in mitochondria and this was significantly reduced in Tom70-silenced macrophages, suggesting the active role of TOM70 in MCL-1 transport. In the mitochondria, MCL-1 interacts with the major pro-apoptotic protein BAK and prevents BAK-BAK homo-oligomer formation thereby preventing cytochrome c release-mediated mitochondrial dysfunction. Silencing of MCL-1 in the spleen of infected mice showed decreased parasite burden and increased induction of splenocyte apoptosis. Collectively our results showed that L. donovani exploited the macrophage anti-apoptotic protein MCL-1 to prevent BAK-mediated mitochondria-dependent apoptosis thereby protecting its niche, which is essential for disease progression. PMID:26670606

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

    PubMed

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

    2016-08-01

    Aluminum (Al)-induced apoptosis is considered as the major cause of its neurotoxicity. Folic acid possesses neuroprotective function by preventing neural cell apoptosis. microRNAs (miRNAs) are important regulators of gene expression participating in cellular processes. As a key component of the miR-17-92 cluster, miR-19 is implicated in regulating apoptotic process, while its role in the neuroprotective effect of folic acid has not been investigated. The present study aimed to investigate the potential involvement and function of miR-19 in the protective action of folic acid against Al-induced neural cell apoptosis. Human SH-SY5Y cells were treated with Al-maltolate (Al-malt) in the presence or absence of folic acid. Results showed that Al-malt-induced apoptosis of SH-SY5Y cells was effectively prevented by folic acid. Al-malt suppressed the expression of miR-19a/19b, along with alterations of miR-19 related apoptotic proteins including PTEN, p-AKT, p53, Bax, Bcl-2, caspase 9 and caspase 3; and these effects were ameliorated by folic acid. miR-19 inhibitor alone induced apoptosis of SH-SY5Y cells. Combination treatment of folic acid and miR-19 inhibitor diminished the neuroprotective effect of folic acid. These findings demonstrated that folic acid protected neuronal cells against Al-malt-induced apoptosis by preventing the downregulation of miR-19 and modulation of miR-19 related downstream PTEN/AKT/p53 pathway. PMID:27113042

  16. cAMP signaling prevents podocyte apoptosis via activation of protein kinase A and mitochondrial fusion.

    PubMed

    Li, Xiaoying; Tao, Hua; Xie, Kewei; Ni, Zhaohui; Yan, Yucheng; Wei, Kai; Chuang, Peter Y; He, John Cijiang; Gu, Leyi

    2014-01-01

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

  17. Staurosporine-induced apoptosis in astrocytes is prevented by A1 adenosine receptor activation.

    PubMed

    D'Alimonte, Iolanda; Ballerini, Patrizia; Nargi, Eleonora; Buccella, Silvana; Giuliani, Patricia; Di Iorio, Patrizia; Caciagli, Francesco; Ciccarelli, Renata

    2007-05-11

    Astrocyte apoptosis occurs in acute and chronic pathological processes at the central nervous system and the prevention of astrocyte death may represent an efficacious intervention in protecting neurons against degeneration. Our research shows that rat astrocyte exposure to 100 nM staurosporine for 3h caused apoptotic death accompanied by caspase-3, p38 mitogen-ed protein kinase (MAPK) and glycogen synthase kinase-3beta (GSK3beta) activation. N(6)-chlorocyclopentyladenosine (CCPA, 2.5-75 nM), a selective agonist of A(1) adenosine receptors, added to the cultures 1h prior to staurosporine, induced a dose-dependent anti-apoptotic effect, which was inhibited by the A(1) receptor antagonist, 8-cyclopentyl-1,3-dipropylxanthine. CCPA also caused a dose- and time-dependent phosphorylation/activation of Akt, a downstream effector of cell survival promoting phosphatidylinositol 3-kinase (PI3K) pathway, which in turn led to inhibition of staurosporine-induced GSK3beta and p38 MAPK activity. Accordingly, the anti-apoptotic effect of CCPA was abolished by culture pre-treatment with LY294002, a selective PI3K inhibitor, pointing out the prevailing role played by PI3K pathway in the protective effect exerted by A(1) receptor activation. Since an abnormal p38 and GSK3beta activity is implicated in acute (stroke) and chronic (Alzheimer's disease) neurodegenerative diseases, the results of the present study provide a hint to better understand adenosine relevance in these disorders. PMID:17400382

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

    PubMed Central

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

    2014-01-01

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

  19. Survivin is expressed in degenerated nucleus pulposus cells and is involved in proliferation and the prevention of apoptosis in vitro

    PubMed Central

    LIN, YAZHOU; YUE, BIN; XIANG, HONGFEI; LIU, YONG; MA, XUEXIAO; CHEN, BOHUA

    2016-01-01

    Survivin is a unique inhibitor of apoptosis, which is frequently present within degenerated human nucleus pulposus (NP) cells. Survivin has been extensively investigated using proliferation and apoptosis assays in tumor cells; however, studies conducted on survivin in degenerative NP cells remain limited to date. The aim of the present study was to investigate survivin expression and its effects on the proliferation and apoptosis of degenerated NP cells in vitro. The expression levels of survivin in the NP cells of patients (>45 years) with lumbar disc degenerative disease and the NP cells of patients (<25 years) with lumbar vertebra fracture were assessed by reverse transcription-quantitative polymerase chain reaction. The effects on in vitro proliferation and apoptosis were investigated through transfection with a specific small interfering (si)RNA. The results of the present study demonstrated that survivin was expressed in the degenerated NP cells, but was undetectable in normal NP cells at the mRNA level. Survivin suppression following transfection with a specific survivin-siRNA reduced the proliferation rate of NP cells and enhanced sensitization to pro-apoptotic stimuli. Therefore, survivin was shown to be expressed and exhibit an important role in the proliferation and prevention of apoptosis of degenerated NP cells. Studies on survivin in NP cells may aid in increasing the understanding of the complex processes underlying NP cell degeneration, and could provide fundamental information for gene therapy to inhibit this degeneration in vitro. PMID:26648308

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

    PubMed

    Jang, Hee-Seong; Padanilam, Babu J

    2015-09-15

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

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

    PubMed Central

    Abdel Moneim, Ahmed E.

    2016-01-01

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

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

    PubMed

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

    2016-06-01

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

  3. Curcumin prevents the non-alcoholic fatty hepatitis via mitochondria protection and apoptosis reduction

    PubMed Central

    Wang, Long; lv, Yisong; Yao, Huixiang; Yin, Li; Shang, Jianhui

    2015-01-01

    Background: Non-alcoholic fatty hepatitis (NASH) is highly prevalent, mitochondria damage is the main pathophysiological characteristic of NASH. However, treatment for mitochondria damage is rarely reported. Methods: NASH model was established in rats, the protective effects of curcumin were evaluated by histological observation; structure and function assessments of mitochondria; and apoptotic genes expression. Results: NASH rats treated with curcumin displayed relatively slight liver damage when compared with NASH livers. The average mitochondrial length and width of NASH (12.0 ± 3.2 and 5.1 ± 1.1 micrometers) were significantly longer than that of normal (6.2 ± 2.1 and 2.1 ± 1.5 micrometers) and NASH treated with curcumin (7.4 ± 1.2 and 3.2 ± 1.5 micrometers) rats. The average malondialdehyde (MDA) and 4-hydroxy nonyl alcohol (HNE) levels in liver homogenates of NASH rats (4.23 ± 0.22 and 19.23 ± 2.3 nmol/Ml) were significantly higher than these in normal (1.32 ± 0.12 and 3.52 ± 0.43 nmol/mL) and NASH treated with curcumin (1.74 ± 0.11 and 4.66 ± 0.99 nmol/mL) rats. The expression levels of CytC, Casp3 and Casp8 of the NASH livers were significantly higher than normal and NASH treated with curcumin rats livers. Conclusion: Our data demonstrated that curcumin prevents the NASH by mitochondria protection and apoptosis reduction and provided a possible novel treatment for NASH. PMID:26617882

  4. Neuronal apoptosis in rats is accompanied by rapid impairment of cellular respiration and is prevented by scavengers of reactive oxygen species.

    PubMed

    Atlante, A; Gagliardi, S; Marra, E; Calissano, P

    1998-04-10

    Apoptosis of cerebellar granule cells induced by potassium withdrawal is accompanied by a very rapid decrease in both cell and mitochondrial respiration supported by glucose and succinate, respectively. The respiratory control ratio, which is an index of oxidative phosphorylation and therefore reflects the ability of mitochondria to produce ATP, is reduced by 50% within the first 2 h after the beginning of apoptosis, insulin-like growth factor I (IGF-I), actinomicin D or cycloheximide, previously reported to inhibit apoptosis, fully prevent the impairment of cellular respiration while scavengers of reactive oxygen species partially inhibit apoptosis and restore cellular respiration. PMID:9605472

  5. Protein Isoaspartate Methyltransferase Prevents Apoptosis Induced by Oxidative Stress in Endothelial Cells: Role of Bcl-Xl Deamidation and Methylation

    PubMed Central

    Cimmino, Amelia; Capasso, Rosanna; Muller, Fabbri; Sambri, Irene; Masella, Lucia; Raimo, Marianna; De Bonis, Maria Luigia; D'Angelo, Stefania; Zappia, Vincenzo; Galletti, Patrizia; Ingrosso, Diego

    2008-01-01

    Background Natural proteins undergo in vivo spontaneous post-biosynthetic deamidation of specific asparagine residues with isoaspartyl formation. Deamidated-isomerized molecules are both structurally and functionally altered. The enzyme isoaspartyl protein carboxyl-O-methyltransferase (PCMT; EC 2.1.1.77) has peculiar substrate specificity towards these deamidated proteins. It catalyzes methyl esterification of the free α-carboxyl group at the isoaspartyl site, thus initiating the repair of these abnormal proteins through the conversion of the isopeptide bond into a normal α-peptide bond. Deamidation occurs slowly during cellular and molecular aging, being accelerated by physical-chemical stresses brought to the living cells. Previous evidence supports a role of protein deamidation in the acquisition of susceptibility to apoptosis. Aim of this work was to shed a light on the role of PCMT in apoptosis clarifying the relevant mechanism(s). Methodology/Principal Findings Endothelial cells transiently transfected with various constructs of PCMT, i.e. overexpressing wild type PCMT or negative dominants, were used to investigate the role of protein methylation during apoptosis induced by oxidative stress (H2O2; 0.1–0.5 mM range). Results show that A) Cells overexpressing “wild type” human PCMT were resistant to apoptosis, whereas overexpression of antisense PCMT induces high sensitivity to apoptosis even at low H2O2 concentrations. B) PCMT protective effect is specifically due to its methyltransferase activity rather than to any other non-enzymatic interactions. In fact negative dominants, overexpressing PCMT mutants devoid of catalytic activity do not prevent apoptosis. C) Cells transfected with antisense PCMT, or overexpressing a PCMT mutant, accumulate isoaspartyl-containing damaged proteins upon H2O2 treatment. Proteomics allowed the identification of proteins, which are both PCMT substrates and apoptosis effectors, whose deamidation occurs under oxidative

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

    PubMed Central

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

    2016-01-01

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

  7. Prevention of apoptosis averts glomerular tubular disconnection and podocyte loss in proteinuric kidney disease.

    PubMed

    Burlaka, Ievgeniia; Nilsson, Linnéa M; Scott, Lena; Holtbäck, Ulla; Eklöf, Ann-Christine; Fogo, Agnes B; Brismar, Hjalmar; Aperia, Anita

    2016-07-01

    There is a great need for treatment that arrests progression of chronic kidney disease. Increased albumin in urine leads to apoptosis and fibrosis of podocytes and tubular cells and is a major cause of functional deterioration. There have been many attempts to target fibrosis, but because of the lack of appropriate agents, few have targeted apoptosis. Our group has described an ouabain-activated Na,K-ATPase/IP3R signalosome, which protects from apoptosis. Here we show that albumin uptake in primary rat renal epithelial cells is accompanied by a time- and dose-dependent mitochondrial accumulation of the apoptotic factor Bax, down-regulation of the antiapoptotic factor Bcl-xL and mitochondrial membrane depolarization. Ouabain opposes these effects and protects from apoptosis in albumin-exposed proximal tubule cells and podocytes. The efficacy of ouabain as an antiapoptotic and kidney-protective therapeutic tool was then tested in rats with passive Heymann nephritis, a model of proteinuric chronic kidney disease. Chronic ouabain treatment preserved renal function, protected from renal cortical apoptosis, up-regulated Bax, down-regulated Bcl-xL, and rescued from glomerular tubular disconnection and podocyte loss. Thus we have identified a novel clinically feasible therapeutic tool, which has the potential to protect from apoptosis and rescue from loss of functional tissue in chronic proteinuric kidney disease. PMID:27217195

  8. Apoptosis-promoted tumorigenesis: gamma-irradiation-induced thymic lymphomagenesis requires Puma-driven leukocyte death.

    PubMed

    Michalak, Ewa M; Vandenberg, Cassandra J; Delbridge, Alex R D; Wu, Li; Scott, Clare L; Adams, Jerry M; Strasser, Andreas

    2010-08-01

    Although tumor development requires impaired apoptosis, we describe a novel paradigm of apoptosis-dependent tumorigenesis. Because DNA damage triggers apoptosis through p53-mediated induction of BH3-only proteins Puma and Noxa, we explored their roles in gamma-radiation-induced thymic lymphomagenesis. Surprisingly, whereas Noxa loss accelerated it, Puma loss ablated tumorigenesis. Tumor suppression by Puma deficiency reflected its protection of leukocytes from gamma-irradiation-induced death, because their glucocorticoid-mediated decimation in Puma-deficient mice activated cycling of stem/progenitor cells and restored thymic lymphomagenesis. Our demonstration that cycles of cell attrition and repopulation by stem/progenitor cells can drive tumorigenesis has parallels in human cancers, such as therapy-induced malignancies. PMID:20679396

  9. Bcl6a function is required during optic cup formation to prevent p53-dependent apoptosis and colobomata

    PubMed Central

    Lee, Jiwoon; Lee, Bum-Kyu; Gross, Jeffrey M.

    2013-01-01

    Mutations in BCOR (Bcl6 corepressor) are found in patients with oculo-facio-cardio-dental (OFCD) syndrome, a congenital disorder affecting visual system development, and loss-of-function studies in zebrafish and Xenopus demonstrate a role for Bcor during normal optic cup development in preventing colobomata. The mechanism whereby BCOR functions during eye development to prevent colobomata is not known, but in other contexts it serves as a transcriptional corepressor that potentiates transcriptional repression by B cell leukemia/lymphoma 6 (BCL6). Here, we have explored the function of the zebrafish ortholog of Bcl6, Bcl6a, during eye development, and our results demonstrate that Bcl6a, like Bcor, is required to prevent colobomata during optic cup formation. Our data demonstrate that Bcl6a acts downstream of Vax1 and Vax2, known regulators of ventral optic cup formation and choroid fissure closure, and that bcl6a is a direct target of Vax2. Together, this regulatory network functions to repress p53 expression and thereby suppress apoptosis in the developing optic cup. Furthermore, our data demonstrate that Bcl6a functions cooperatively with Bcor, Rnf2 and Hdac1 in a common gene regulatory network that acts to repress p53 and prevent colobomata. Together, these data support a model in which p53-dependent apoptosis needs to be tightly regulated for normal optic cup formation and that Bcl6a, Bcor, Rnf2 and Hdac1 activities mediate this regulation. PMID:23669349

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

    PubMed Central

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

    2013-01-01

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

  11. Inhibition of polyamine oxidase prevented cyclin-dependent kinase inhibitor-induced apoptosis in HCT 116 colon carcinoma cells.

    PubMed

    Gürkan, Ajda Coker; Arisan, Elif Damla; Obakan, Pinar; Palavan-Ünsal, Narçin

    2013-12-01

    Roscovitine and purvalanol are novel cyclin-dependent kinase (CDK) inhibitors that prevent cell proliferation and induce apoptotic cell death in various cancer cell lines. Although a number of studies have demonstrated the potential apoptotic role of roscovitine, there is limited data about the therapeutic efficiency of purvalanol on cancer cells. The natural polyamines (PAs) putrescine, spermidine, and spermine have essential roles in the regulation of cell differentiation, growth, and proliferation, and increased levels of these compounds have been associated with cancer progression. Recently, depletion of intracellular PA levels because of modulation of PA catabolic enzymes was shown to be an indicator of the efficacy of chemotherapeutic agents. In this study, our aim was to investigate the potential role of PA catabolic enzymes in CDK inhibitor-induced apoptosis in HCT 116 colon carcinoma cells. Exposure of cells to roscovitine or purvalanol decreased cell viability in a dose- and time-dependent manner. The selected concentrations of roscovitine and purvalanol inhibited cell viability by 50 % compared with control cells and induced apoptosis by activating the mitochondria-mediated pathway in a caspase-dependent manner. However, the apoptotic effect of purvalanol was stronger than that of roscovitine in HCT 116 cells. In addition, we found that CDK inhibitors decreased PA levels and significantly upregulated expression of key PA catabolic enzymes such as polyamine oxidase (PAO) and spermine oxidase (SMO). MDL-72,527, a specific inhibitor of PAO and SMO, decreased apoptotic potential of CDK inhibitors on HCT 116 cells. Moreover, transient silencing of PAO was also reduced prevented CDK inhibitor-induced apoptosis in HCT 116 cells. We conclude that the PA catabolic pathway, especially PAO, is a critical target for understanding the molecular mechanism of CDK inhibitor-induced apoptosis. PMID:23892915

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

    PubMed

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

    2016-06-14

    Neuronal cell apoptosis is an important pathological change in Alzheimer's disease (AD). Hydrogen sulfide (H(2)S) is known to be a novel gaseous signaling molecule and a cytoprotectant in many diseases including AD. However, the molecular mechanism of the antiapoptosis activity of H(2)S in AD is not yet fully understood. The aim of the present study is to evaluate the inhibitory effects of H(2)S on Abeta (Aβ)-induced apoptosis and the molecular mechanisms underlying primary neuron cells. Our results showed that sodium hydrosulfide (NaHS), a donor of H(2)S, significantly ameliorated Aβ-induced cell apoptosis. NaHS also reversed the Aβ-induced translocation of the phosphatase and tensin homologs deleted on chromosome 10 (PTEN) from the cytosol to the mitochondria. Furthermore, H(2)S increased the level of p-AKT/AKT significantly. Interestingly, the antiapoptosis effects of H(2)S were blocked down by specific PI3K/AKT inhibitor wortmannin. In conclusion, these data indicate that H(2)S inhibits Aβ-induced neuronal apoptosis by attenuating mitochondrial translocation of PTEN and that activation of PI3K/AKT signaling pathway plays a critical role in H(2)S-mediated neuronal protection. Our findings provide a novel route into the molecular mechanisms of neuronal apoptosis in AD. PMID:27026591

  13. Prevention of oxidative stress-induced apoptosis of C2C12 myoblasts by a Cichorium intybus root extract.

    PubMed

    Lee, Yong-Hyeon; Kim, Dae-Hyun; Kim, Yoon Suk; Kim, Tack-Joong

    2013-01-01

    Cell injury associated with reactive oxygen species (ROS) has been reported in various muscular disorders. We found that a Cichorium intybus (Cii) extract reduced H(2)O(2)-induced viability loss in C2C12 myoblasts, inhibited oxidative stress-induced apoptosis and increased intracellular heat shock protein 70 (Hsp 70) expression. Cii also inhibited the level of intracellular ceramide. These results indicate that Cii may prevent skeletal muscle atrophy by inducing the expression of Hsp 70 and inhibiting the level of ceramide. PMID:23391909

  14. Nrf2 Protein Up-regulates Antiapoptotic Protein Bcl-2 and Prevents Cellular Apoptosis*

    PubMed Central

    Niture, Suryakant K.; Jaiswal, Anil K.

    2012-01-01

    Nuclear transcription factor Nrf2 regulates the expression and coordinated induction of a battery of genes encoding cytoprotective and drug transporter proteins in response to chemical and radiation stress. This leads to reduced apoptosis, enhanced cell survival, and increased drug resistance. In this study, we investigated the role of Nrf2 in up-regulation of antiapoptotic protein Bcl-2 and its contribution to stress-induced apoptosis and cell survival. Exposure of mouse hepatoma (Hepa-1) and human hepatoblastoma (HepG2) cells to antioxidant tert-butylhydroquinone led to induction of Bcl-2. Mutagenesis and transfection assays identified an antioxidant response element between nucleotides −3148 and −3140 on the reverse strand of the Bcl-2 gene promoter that was essential for activation of Bcl-2 gene expression. Band/supershift and ChIP assays demonstrated binding of Nrf2 to Bcl-2 antioxidant response element. Alterations in Nrf2 led to altered Bcl-2 induction and cellular apoptosis. Moreover, dysfunctional/mutant inhibitor of Nrf2 (INrf2) in human lung cancer cells failed to degrade Nrf2, resulting in an increased Bcl-2 level and decreased etoposide- and UV/γ radiation-mediated DNA fragmentation. In addition, siRNA-mediated down-regulation of Nrf2 also led to decreased apoptosis and increased cell survival. Furthermore, the specific knockdown of Bcl-2 in Nrf2-activated tumor cells led to increased etoposide-induced apoptosis and decreased cell survival and growth/proliferation. These data provide the first evidence of Nrf2 in control of Bcl-2 expression and apoptotic cell death with implications in antioxidant protection, survival of cancer cells, and drug resistance. PMID:22275372

  15. Selenoprotein S Is Highly Expressed in the Blood Vessels and Prevents Vascular Smooth Muscle Cells From Apoptosis.

    PubMed

    Ye, Yali; Fu, Fen; Li, Xiaoming; Yang, Jie; Liu, Hongmei

    2016-01-01

    Atherosclerosis and related cardiovascular diseases (CVD) represent one of the greatest threats to human health worldwide. The protection of vascular smooth muscle cells (VSMCs) from apoptosis in the plaque has become an important therapeutic target for atherosclerotic plaque stabilization. A significant association of selenoprotein S (SelS) gene polymorphism with atherosclerotic CVD has been reported in epidemiologic studies, but the underlying mechanism remains unknown. In this paper, SelS expression in the thoracic aorta and its role in the protection of VSMCs from apoptosis have been studied. Western blot analysis showed that SelS was highly expressed in rat thoracic aorta. SelS gene silence by small interference RNA (siRNA) rendered VSMCs more sensitive to hydrogen peroxide- or tunicamycin- induced injury and apoptosis, as determined by MTT assay, Hoechst staining, and annexin V/propidium iodide staining. SelS silence aggravated hydrogen peroxide-induced oxidative stress and phosphorylation of p38 MAPK and c-Jun N-terminal kinase (JNK) in VSMCs. Furthermore, SelS silence enhanced endoplasmic reticulum (ER) stress induced by hydrogen peroxide or tunicamycin, as showed by the increased protein levels of ER chaperone 78 kDa glucose-regulated protein (GRP78), ER stress transducer phosphorylated protein kinase RNA like ER kinase (PERK), and the proapoptotic transcription factor C/EBP homologous protein (CHOP). In conclusion, the present study suggested that SelS highly expressed in the blood vessel might protect VSMCs from apoptosis by inhibiting oxidative stress and ER stress. Our finding provided mechanistic insights for the potential preventive role of SelS in atherosclerotic CVD. PMID:26058460

  16. INHIBITION OF CDK9 PREVENTS MECHANICAL INJURY-INDUCED INFLAMMATION, APOPTOSIS AND MATRIX DEGRADATION IN CARTILAGE EXPLANTS

    PubMed Central

    Hu, Z.; Yik, J.H.N.; Cissell, D.D.; Michelier, P.V.; Athanasiou, K.A.; Haudenschild, D.R.

    2016-01-01

    Joint injury often leads to post-traumatic osteoarthritis (PTOA). Acute injury responses to trauma induce production of pro-inflammatory cytokines and catabolic enzymes, which promote chondrocyte apoptosis and degrade cartilage to potentiate PTOA development. Recent studies show that the rate-limiting step for transcriptional activation of injury response genes is controlled by cyclin-dependent kinase 9 (CDK9), and thus it is an attractive target for limiting the injury response. Here, we determined the effects of CDK9 inhibition in suppressing the injury response in mechanically-injured cartilage explants. Bovine cartilage explants were injured by a single compressive load of 30 % strain at 100 %/s, and then treated with the CDK9 inhibitor Flavopiridol. To assess acute injury responses, we measured the mRNA expression of pro-inflammatory cytokines, catabolic enzymes, and apoptotic genes by RT-PCR, and chondrocyte viability and apoptosis by TUNEL staining. For long-term outcome, cartilage matrix degradation was assessed by soluble glycosaminoglycan release, and by determining the mechanical properties with instantaneous and relaxation moduli. Our data showed CDK9 inhibitor markedly reduced injury-induced inflammatory cytokine and catabolic gene expression. CDK9 inhibitor also attenuated chondrocyte apoptosis and reduced cartilage matrix degradation. Lastly, the mechanical properties of the injured explants were preserved by CDK9 inhibitor. Our results provide a temporal profile connecting the chain of events from mechanical impact, acute injury responses, to the subsequent induction of chondrocyte apoptosis and cartilage matrix deterioration. Thus, CDK9 is a potential disease-modifying agent for injury response after knee trauma to prevent or delay PTOA development. PMID:26859911

  17. The New Biology of Estrogen-induced Apoptosis Applied to Treat and Prevent Breast Cancer

    PubMed Central

    Jordan, V Craig

    2014-01-01

    The successful use of high dose synthetic estrogens to treat post-menopausal metastatic breast cancer, is the first effective “chemical therapy” proven in clinical trial to treat any cancer. This review documents the clinical use of estrogen for breast cancer treatment or estrogen replacement therapy (ERT) for postmenopausal hysterectomized women which can either result in breast cancer cell growth or breast cancer regression. This has remained a paradox since the 1950s until the discovery of the new biology of estrogen induced apoptosis at the end of the 20th century. The key to triggering apoptosis with estrogen is the selection of breast cancer cell populations that are resistant to long term estrogen deprivation. However, through trial and error estrogen independent growth occurs. At the cellular level, estrogen induced apoptosis is dependent upon the presence of the estrogen receptor (ER) which can be blocked by non-steroidal or steroidal anti-estrogens. The shape of an estrogenic ligand programs the conformation of the ER complex which in turn can modulate estrogen induced apoptosis: class I planar estrogens (eg: estradiol) trigger apoptosis after 24 hours whereas class II angular estrogens (eg: bisphenol triphenylethylene) delay the process until after 72 hours. This contrasts with paclitaxel that causes G2 blockade with immediate apoptosis. The process is complete within 24 hours. Estrogen induced apoptosis is modulated by glucocorticoids and cSrc inhibitors but the target mechanism for estrogen action is genomic and not through a non-genomic pathway. The process is step wise through the creation of endoplasmic reticulum stress and, inflammatory responses that then initiate an unfolded protein response. This in turn initiates apoptosis through the intrinsic pathway (mitochondrial) with subsequent recruitment of the extrinsic pathway (death receptor) to complete the process. The symmetry of the clinical and laboratory studies now permits the creation of

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

    PubMed Central

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

    2013-01-01

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

  19. Nicorandil Prevents Right Ventricular Remodeling by Inhibiting Apoptosis and Lowering Pressure Overload in Rats with Pulmonary Arterial Hypertension

    PubMed Central

    Yu, Yan-Zhe; Wang, Hui; Bi, Li-Qing; Xie, Wei-Ping; Wang, Hong

    2012-01-01

    Background Most of the deaths among patients with severe pulmonary arterial hypertension (PAH) are caused by progressive right ventricular (RV) pathological remodeling, dysfunction, and failure. Nicorandil can inhibit the development of PAH by reducing pulmonary artery pressure and RV hypertrophy. However, whether nicorandil can inhibit apoptosis in RV cardiomyocytes and prevent RV remodeling has been unclear. Methodology/Principal Findings RV remodeling was induced in rats by intraperitoneal injection of monocrotaline (MCT). RV systolic pressure (RVSP) was measured at the end of each week after MCT injection. Blood samples were drawn for brain natriuretic peptide (BNP) ELISA analysis. The hearts were excised for histopathological, ultrastructural, immunohistochemical, and Western blotting analyses. The MCT-injected rats exhibited greater mortality and less weight gain and showed significantly increased RVSP and RV hypertrophy during the second week. These worsened during the third week. MCT injection for three weeks caused pathological RV remodeling, characterized by hypertrophy, fibrosis, dysfunction, and RV mitochondrial impairment, as indicated by increased levels of apoptosis. Nicorandil improved survival, weight gain, and RV function, ameliorated RV pressure overload, and prevented maladaptive RV remodeling in PAH rats. Nicorandil also reduced the number of apoptotic cardiomyocytes, with a concomitant increase in Bcl-2/Bax ratio. 5-hydroxydecanoate (5-HD) reversed these beneficial effects of nicorandil in MCT-injected rats. Conclusions/Significance Nicorandil inhibits PAH-induced RV remodeling in rats not only by reducing RV pressure overload but also by inhibiting apoptosis in cardiomyocytes through the activation of mitochondrial ATP-sensitive K+ (mitoKATP) channels. The use of a mitoKATP channel opener such as nicorandil for PAH-associated RV remodeling and dysfunction may represent a new therapeutic strategy for the amelioration of RV remodeling during

  20. Azelnidipine prevents cardiac dysfunction in streptozotocin-diabetic rats by reducing intracellular calcium accumulation, oxidative stress and apoptosis

    PubMed Central

    2011-01-01

    Background Numerous evidences suggest that diabetic heart is characterized by compromised ventricular contraction and prolonged relaxation attributable to multiple causative factors including calcium accumulation, oxidative stress and apoptosis. Therapeutic interventions to prevent calcium accumulation and oxidative stress could be therefore helpful in improving the cardiac function under diabetic condition. Methods This study was designed to examine the effect of long-acting calcium channel blocker (CCB), Azelnidipine (AZL) on contractile dysfunction, intracellular calcium (Ca2+) cycling proteins, stress-activated signaling molecules and apoptosis on cardiomyocytes in diabetes. Adult male Wistar rats were made diabetic by a single intraperitoneal (IP) injection of streptozotocin (STZ). Contractile functions were traced from live diabetic rats to isolated individual cardiomyocytes including peak shortening (PS), time-to-PS (TPS), time-to-relengthening (TR90), maximal velocity of shortening/relengthening (± dL/dt) and intracellular Ca2+ fluorescence. Results Diabetic heart showed significantly depressed PS, ± dL/dt, prolonged TPS, TR90 and intracellular Ca2+ clearing and showed an elevated resting intracellular Ca2+. AZL itself exhibited little effect on myocyte mechanics but it significantly alleviated STZ-induced myocyte contractile dysfunction. Diabetes increased the levels of superoxide, enhanced expression of the cardiac damage markers like troponin I, p67phox NADPH oxidase subunit, restored the levels of the mitochondrial superoxide dismutase (Mn-SOD), calcium regulatory proteins RyR2 and SERCA2a, and suppressed the levels of the anti-apoptotic Bcl-2 protein. All of these STZ-induced alterations were reconciled by AZL treatment. Conclusion Collectively, the data suggest beneficial effect of AZL in diabetic cardiomyopathy via altering intracellular Ca2+ handling proteins and preventing apoptosis by its antioxidant property. PMID:22054019

  1. Sodium fluoride induces apoptosis in mouse embryonic stem cells through ROS-dependent and caspase- and JNK-mediated pathways

    SciTech Connect

    Nguyen Ngoc, Tam Dan; Son, Young-Ok; Lim, Shin-Saeng; Shi, Xianglin; Kim, Jong-Ghee; Heo, Jung Sun; Choe, Youngji; Jeon, Young-Mi; Lee, Jeong-Chae

    2012-03-15

    Sodium fluoride (NaF) is used as a source of fluoride ions in diverse applications. Fluoride salt is an effective prophylactic for dental caries and is an essential element required for bone health. However, fluoride is known to cause cytotoxicity in a concentration-dependent manner. Further, no information is available on the effects of NaF on mouse embryonic stem cells (mESCs). We investigated the mode of cell death induced by NaF and the mechanisms involved. NaF treatment greater than 1 mM reduced viability and DNA synthesis in mESCs and induced cell cycle arrest in the G{sub 2}/M phase. The addition of NaF induced cell death mainly by apoptosis rather than necrosis. Catalase (CAT) treatment significantly inhibited the NaF-mediated cell death and also suppressed the NaF-mediated increase in phospho-c-Jun N-terminal kinase (p-JNK) levels. Pre-treatment with SP600125 or z-VAD-fmk significantly attenuated the NaF-mediated reduction in cell viability. In contrast, intracellular free calcium chelator, but not of sodium or calcium ion channel blockers, facilitated NaF-induced toxicity in the cells. A JNK specific inhibitor (SP600125) prevented the NaF-induced increase in growth arrest and the DNA damage-inducible protein 45α. Further, NaF-mediated loss of mitochondrial membrane potential was apparently inhibited by pifithrin-α or CAT inhibitor. These findings suggest that NaF affects viability of mESCs in a concentration-dependent manner, where more than 1 mM NaF causes apoptosis through hydroxyl radical-dependent and caspase- and JNK-mediated pathways. -- Highlights: ► The mode of NaF-induced cell death and the mechanisms involved were examined. ► NaF induced mainly apoptotic death of mouse embryonic stem cells (mESCs). ► NaF induced mitochondrial-mediated and caspase-dependent apoptosis. ► JNK- and p53-mediated pathways are involved in NaF-mediated apoptosis in the cells. ► ROS are the up-stream effector in NaF-mediated activation of JNK and p53 in mESCs.

  2. Long-term caloric restriction in mice may prevent age-related learning impairment via suppression of apoptosis.

    PubMed

    Ma, Lina; Wang, Rong; Dong, Wen; Li, Yun; Xu, Baolei; Zhang, Jingshuang; Zhao, Zhiwei

    2016-12-15

    Caloric restriction (CR) is the most reliable intervention to extend lifespan and prevent age-related disorders in various species from yeast to rodents. However, the underlying mechanisms have not yet been clearly defined. Therefore, we aimed to identify the underlying mechanisms of long-term CR on age-related learning impairment in C57/BL mice. Thirty six-week-old male C57/BL mice were randomly divided into three groups: normal control group (NC group, n=10), high energy group (HE group, n=10), and CR group (n=10). After 10 months, the Morris water maze test was performed to monitor learning abilities. Western blotting, immunohistochemistry and real-time polymerase chain reaction were used to monitor changes in protein and mRNA levels associated with apoptosis-related proteins in the hippocampus. The average escape latency was lower in the CR group compared with the NC group, and the average time taken to first cross the platform in the CR group was significantly shorter than the HE group. Both Bcl-2 protein and mRNA expression levels in the CR group were significantly higher than those of the NC group and HE group. The expression of Bax, Caspase-3 and PARP protein in the CR group was significantly lower than the NC group. Our findings demonstrate that long-term CR may prevent age-related learning impairments via suppressing apoptosis in mice. PMID:27452805

  3. Prevention of neonatal oxygen-induced brain damage by reduction of intrinsic apoptosis

    PubMed Central

    Sifringer, M; Bendix, I; Börner, C; Endesfelder, S; von Haefen, C; Kalb, A; Holifanjaniaina, S; Prager, S; Schlager, G W; Keller, M; Jacotot, E; Felderhoff-Mueser, U

    2012-01-01

    Within the last decade, it became clear that oxygen contributes to the pathogenesis of neonatal brain damage, leading to neurocognitive impairment of prematurely born infants in later life. Recently, we have identified a critical role for receptor-mediated neuronal apoptosis in the immature rodent brain. However, the contribution of the intrinsic apoptotic pathway accompanied by activation of caspase-2 under hyperoxic conditions in the neonatal brain still remains elusive. Inhibition of caspases appears a promising strategy for neuroprotection. In order to assess the influence of specific caspases on the developing brain, we applied a recently developed pentapeptide-based group II caspase inhibitor (5-(2,6-difluoro-phenoxy)-3(R,S)-(2(S)-(2(S)-(3-methoxycarbonyl-2(S)-(3-methyl-2(S)-((quinoline-2-carbonyl)-amino)-butyrylamino)propionylamino)3-methylbutyrylamino)propionylamino)-4-oxo-pentanoic acid methyl ester; TRP601). Here, we report that elevated oxygen (hyperoxia) triggers a marked increase in active caspase-2 expression, resulting in an initiation of the intrinsic apoptotic pathway with upregulation of key proteins, namely, cytochrome c, apoptosis protease-activating factor-1, and the caspase-independent protein apoptosis-inducing factor, whereas BH3-interacting domain death agonist and the anti-apoptotic protein B-cell lymphoma-2 are downregulated. These results coincide with an upregulation of caspase-3 activity and marked neurodegeneration. However, single treatment with TRP601 at the beginning of hyperoxia reversed the detrimental effects in this model. Hyperoxia-mediated neurodegeneration is supported by intrinsic apoptosis, suggesting that the development of highly selective caspase inhibitors will represent a potential useful therapeutic strategy in prematurely born infants. PMID:22237207

  4. Cordyceps sinensis prevents apoptosis in mouse liver with D-galactosamine/lipopolysaccharide-induced fulminant hepatic failure.

    PubMed

    Cheng, Yu-Jung; Cheng, Shiu-Min; Teng, Yi-Hsien; Shyu, Woei-Cherng; Chen, Hsiu-Ling; Lee, Shin-Da

    2014-01-01

    Cordyceps sinensis (C. sinensis) has long been considered to be an herbal medicine and has been used in the treatment of various inflammatory diseases. The present study examined the cytoprotective properties of C. sinensis on D(+)-galactosamine (GalN)/lipopolysaccharide (LPS)-induced fulminant hepatic failure. Mice were randomly assigned into control, GalN/LPS, CS 20 mg and CS 40 mg groups (C. sinensis, oral gavage, five days/week, four weeks). After receiving saline or C. sinensis, mice were intraperitoneally given GalN (800 mg/kg)/LPS (10 μg/kg). The effects of C. sinensis on TNF-α, IL-10, AST, NO, SOD, and apoptoticrelated proteins after the onset of endotoxin intoxication were determined. Data demonstrated that GalN/LPS increased hepatocyte degeneration, circulating AST, TNF-α, IL-10, and hepatic apoptosis and caspase activity. C. sinensis pre-treatment reduced AST, TNF-α, and NO and increased IL-10 and SOD in GalN/LPS induced fulminant hepatic failure. C. sinensis attenuated the apoptosis of hepatocytes, as evidenced by the TUNEL and capase-3, 6 activity analyses. In summary, C. sinensis alleviates GalN/LPS-induced liver injury by modulating the cytokine response and inhibiting apoptosis. PMID:24707872

  5. p14(ARF) Prevents Proliferation of Aneuploid Cells by Inducing p53-Dependent Apoptosis.

    PubMed

    Veneziano, Lorena; Barra, Viviana; Lentini, Laura; Spatafora, Sergio; Di Leonardo, Aldo

    2016-02-01

    Weakening the Spindle Assembly Checkpoint by reduced expression of its components induces chromosome instability and aneuploidy that are hallmarks of cancer cells. The tumor suppressor p14(ARF) is overexpressed in response to oncogenic stimuli to stabilize p53 halting cell progression. Previously, we found that lack or reduced expression of p14(ARF) is involved in the maintenance of aneuploid cells in primary human cells, suggesting that it could be part of a pathway controlling their proliferation. To investigate this aspect further, p14(ARF) was ectopically expressed in HCT116 cells after depletion of the Spindle Assembly Checkpoint MAD2 protein that was used as a trigger for aneuploidy. p14(ARF) Re-expression reduced the number of aneuploid cells in MAD2 post-transcriptionally silenced cells. Also aberrant mitoses, frequently displayed in MAD2-depleted cells, were decreased when p14(ARF) was expressed at the same time. In addition, p14(ARF) ectopic expression in MAD2-depleted cells induced apoptosis associated with increased p53 protein levels. Conversely, p14(ARF) ectopic expression did not induce apoptosis in HCT116 p53KO cells. Collectively, our results suggest that the tumor suppressor p14(ARF) may have an important role in counteracting proliferation of aneuploid cells by activating p53-dependent apoptosis. PMID:25752701

  6. Pharmacologically blocking p53-dependent apoptosis protects intestinal stem cells and mice from radiation.

    PubMed

    Wang, Xinwei; Wei, Liang; Cramer, Julie M; Leibowitz, Brian J; Judge, Colleen; Epperly, Michael; Greenberger, Joel; Wang, Fengchao; Li, Linheng; Stelzner, Matthias G; Dunn, James C Y; Martin, Martin G; Lagasse, Eric; Zhang, Lin; Yu, Jian

    2015-01-01

    Exposure to high levels of ionizing radiation (IR) leads to debilitating and dose-limiting gastrointestinal (GI) toxicity. Using three-dimensional mouse crypt culture, we demonstrated that p53 target PUMA mediates radiation-induced apoptosis via a cell-intrinsic mechanism, and identified the GSK-3 inhibitor CHIR99021 as a potent radioprotector. CHIR99021 treatment improved Lgr5+ cell survival and crypt regeneration after radiation in culture and mice. CHIR99021 treatment specifically blocked apoptosis and PUMA induction and K120 acetylation of p53 mediated by acetyl-transferase Tip60, while it had no effect on p53 stabilization, phosphorylation or p21 induction. CHIR99021 also protected human intestinal cultures from radiation by PUMA but not p21 suppression. These results demonstrate that p53 posttranslational modifications play a key role in the pathological and apoptotic response of the intestinal stem cells to radiation and can be targeted pharmacologically. PMID:25858503

  7. Pharmacologically blocking p53-dependent apoptosis protects intestinal stem cells and mice from radiation

    PubMed Central

    Wang, Xinwei; Wei, Liang; Cramer, Julie M.; Leibowitz, Brian J.; Judge, Colleen; Epperly, Michael; Greenberger, Joel; Wang, Fengchao; Li, Linheng; Stelzner, Matthias G.; Dunn, James C. Y.; Martin, Martin G.; Lagasse, Eric; Zhang, Lin; Yu, Jian

    2015-01-01

    Exposure to high levels of ionizing radiation (IR) leads to debilitating and dose-limiting gastrointestinal (GI) toxicity. Using three-dimensional mouse crypt culture, we demonstrated that p53 target PUMA mediates radiation-induced apoptosis via a cell-intrinsic mechanism, and identified the GSK-3 inhibitor CHIR99021 as a potent radioprotector. CHIR99021 treatment improved Lgr5+ cell survival and crypt regeneration after radiation in culture and mice. CHIR99021 treatment specifically blocked apoptosis and PUMA induction and K120 acetylation of p53 mediated by acetyl-transferase Tip60, while it had no effect on p53 stabilization, phosphorylation or p21 induction. CHIR99021 also protected human intestinal cultures from radiation by PUMA but not p21 suppression. These results demonstrate that p53 posttranslational modifications play a key role in the pathological and apoptotic response of the intestinal stem cells to radiation and can be targeted pharmacologically. PMID:25858503

  8. Salinomycin sensitizes antimitotic drugs-treated cancer cells by increasing apoptosis via the prevention of G2 arrest

    SciTech Connect

    Kim, Ju-Hwa; Yoo, Hye-In; Kang, Han Sung; Ro, Jungsil; Yoon, Sungpil

    2012-02-03

    Highlights: Black-Right-Pointing-Pointer Sal sensitizes antimitotic drugs-treated cancer cells. Black-Right-Pointing-Pointer Sal sensitizes them by prevention of G2 arrest and reduced cyclin D1 levels. Black-Right-Pointing-Pointer Sal also sensitizes them by increasing DNA damage and reducing p21 level. Black-Right-Pointing-Pointer A low concentration of Sal effectively sensitized the cancer cells to antimitotic drugs. -- Abstract: Here, we investigated whether Sal could sensitize cancer cells to antimitotic drugs. We demonstrated that Sal sensitized paclitaxcel (PAC)-, docetaxcel (DOC)-, vinblastin (VIN)-, or colchicine (COL)-treated cancer cell lines, suggesting that Sal has the ability to sensitize the cells to any form of microtubule-targeting drugs. Sensitization to the antimitotic drugs could be achieved with very low concentrations of Sal, suggesting that there is a possibility to minimize Sal toxicity associated with human cancer patient treatments. Sensitization by Sal increased apoptosis, which was observed by C-PARP production. Sal sensitized the cancer cells to antimitotic drugs by preventing G2 arrest, suggesting that Sal contributes to the induction of mitotic catastrophe. Sal generally reduced cyclin D1 levels in PAC-, DOC-, and VIN-treated cells. In addition, Sal treatment increased pH2AX levels and reduced p21 levels in antimitotic drugs-treated cells. These observations suggest that the mechanisms underlying Sal sensitization to DNA-damaging compounds, radiation, and microtubule-targeting drugs are similar. Our data demonstrated that Sal sensitizes cancer cells to antimitotic drugs by increasing apoptosis through the prevention of G2 arrest via conserved Sal-sensitization mechanisms. These results may contribute to the development of Sal-based chemotherapy for cancer patients treated with antimitotic drugs.

  9. Mutation of the Myxoma virus SERP2 P1-site to prevent proteinase inhibition causes apoptosis in cultured RK-13 cells and attenuates disease in rabbits, but mutation to alter specificity causes apoptosis without reducing virulence.

    PubMed

    MacNeill, Amy L; Turner, Peter C; Moyer, Richard W

    Myxoma virus (MYX) prevents apoptosis in RK-13 cells and forms thick dermal lesions with 100% mortality in rabbits. MYX encodes the virulence factor SERP2, a serine proteinase inhibitor (serpin). SERP2 was mutated to evaluate SERP2 function during MYX infection. MYXDeltaSERP2::lacZ (deleted for SERP2) did not inhibit apoptosis in RK-13 cells; infected rabbits had thin dermal lesions and <10% mortality. MYX-SERP2-D294A, a P1-site aspartate to alanine mutant, inactivated the serpin; infection was indistinguishable from MYXDeltaSERP2::lacZ. SERP2-D294E prevented inhibition of caspase-8, caspase-10 and granzyme-B; and MYX-SERP2-D294E failed to block apoptosis in RK-13 cells, but was fully virulent in rabbits. MYXDeltaSERP2::crmA expressed crmA instead of SERP2 and inhibited apoptosis in cell culture, but caused thin lesions and only 70% mortality in rabbits, hence crmA cannot fully substitute for SERP2. Control of apoptosis in culture does not correlate with virulence in rabbits. Virulence may instead depend on inhibition of proinflammatory proteinases by SERP2. PMID:16959285

  10. Rasagiline prevents cyclosporine A-sensitive superoxide flashes induced by PK11195, the initial signal of mitochondrial membrane permeabilization and apoptosis.

    PubMed

    Wu, Yuqiu; Shamoto-Nagai, Masayo; Maruyama, Wakako; Osawa, Toshihiko; Naoi, Makoto

    2016-05-01

    Rasagiline, a neuroprotective inhibitor of type B monoamine oxidase, prevented PK111195-induced apoptosis in SH-SY5Y cells through inhibition of mitochondrial apoptosis signaling (J Neural Transm 120:1539-1551, 2013, J Neural Transm 122:1399-1407, 2015). This paper presents that PK11195 induced superoxide flashes, the transit production burst, mediated by cyclosporine A-sensitive membrane permeability transition. Rasagiline prevented superoxide flashes, calcium efflux, and cell death by PK11195. Regulation of the initial pore formation at the inner mitochondrial membrane was confirmed as the decisive mechanism of neuroprotection by rasagiline. PMID:26931622

  11. Fluoxetine enhances cell proliferation and prevents apoptosis in dentate gyrus of maternally separated rats.

    PubMed

    Lee, H J; Kim, J W; Yim, S V; Kim, M J; Kim, S A; Kim, Y J; Kim, C J; Chung, J H

    2001-11-01

    The mother-infant relationship is an instinctive phenomenon, and loss of maternal care in early life influences neonatal development, behavior and physiologic responses.(1,2) Furthermore, the early loss may affect the vulnerability of the infant to neuropsychiatric disorders, such as childhood anxiety disorders, personality disorders and depression, over its lifespan.(3,4) Fluoxetine is prescribed worldwide for depression and is often used in the treatment of childhood mental problems related to maternal separation or loss of maternal care.(5,6) In the present study, fluoxetine was administrated to rats with maternal separation to determine its effects on neuronal development, in particular with respect to cell proliferation and apoptosis in the dentate gyrus of the hippocampus. Rat pups were separated from their mothers and socially isolated on postnatal day 14 and were treated with fluoxetine (5 mg kg(-1)) and 5-bromo-2'-deoxyuridine (BrdU) (50 mg kg(-1)) for 7 days, after which immunohistochemistry and a terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining were carried out. In the pups with maternal separation treated with fluoxetine, the number of BrdU-positive cells was significantly increased and that of TUNEL-positive cells was significantly decreased in the dentate gyrus compared to pups with maternal separation that did not receive fluoxetine treatment. These findings indicate that fluoxetine affects new cell proliferation and apoptosis, and we propose that fluoxetine may be useful in the treatment of maternal separation-related diseases. PMID:11673802

  12. Monoamine oxidase inhibition prevents mitochondrial dysfunction and apoptosis in myoblasts from patients with collagen VI myopathies

    PubMed Central

    Sorato, E.; Menazza, S.; Zulian, A.; Sabatelli, P.; Gualandi, F.; Merlini, L.; Bonaldo, P.; Canton, M.; Bernardi, P.; Di Lisa, F.

    2014-01-01

    Although mitochondrial dysfunction and oxidative stress have been proposed to play a crucial role in several types of muscular dystrophy (MD), whether a causal link between these two alterations exists remains an open question. We have documented that mitochondrial dysfunction through opening of the permeability transition pore plays a key role in myoblasts from patients as well as in mouse models of MD, and that oxidative stress caused by monoamine oxidases (MAO) is involved in myofiber damage. In the present study we have tested whether MAO-dependent oxidative stress is a causal determinant of mitochondrial dysfunction and apoptosis in myoblasts from patients affected by collagen VI myopathies. We find that upon incubation with hydrogen peroxide or the MAO substrate tyramine myoblasts from patients upregulate MAO-B expression and display a significant rise in reactive oxygen species (ROS) levels, with concomitant mitochondrial depolarization. MAO inhibition by pargyline significantly reduced both ROS accumulation and mitochondrial dysfunction, and normalized the increased incidence of apoptosis in myoblasts from patients. Thus, MAO-dependent oxidative stress is causally related to mitochondrial dysfunction and cell death in myoblasts from patients affected by collagen VI myopathies, and inhibition of MAO should be explored as a potential treatment for these diseases. PMID:25017965

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

    PubMed Central

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

    2015-01-01

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

  14. Molecular pathways: gene-environment interactions regulating dietary fiber induction of proliferation and apoptosis via butyrate for cancer prevention.

    PubMed

    Bultman, Scott J

    2014-02-15

    Gene-environment interactions are so numerous and biologically complicated that it can be challenging to understand their role in cancer. However, dietary fiber and colorectal cancer prevention may represent a tractable model system. Fiber is fermented by colonic bacteria into short-chain fatty acids such as butyrate. One molecular pathway that has emerged involves butyrate having differential effects depending on its concentration and the metabolic state of the cell. Low-moderate concentrations, which are present near the base of colonic crypts, are readily metabolized in the mitochondria to stimulate cell proliferation via energetics. Higher concentrations, which are present near the lumen, exceed the metabolic capacity of the colonocyte. Unmetabolized butyrate enters the nucleus and functions as a histone deacetylase (HDAC) inhibitor that epigenetically regulates gene expression to inhibit cell proliferation and induce apoptosis as the colonocytes exfoliate into the lumen. Butyrate may therefore play a role in normal homeostasis by promoting turnover of the colonic epithelium. Because cancerous colonocytes undergo the Warburg effect, their preferred energy source is glucose instead of butyrate. Consequently, even moderate concentrations of butyrate accumulate in cancerous colonocytes and function as HDAC inhibitors to inhibit cell proliferation and induce apoptosis. These findings implicate a bacterial metabolite with metaboloepigenetic properties in tumor suppression. PMID:24270685

  15. Fenugreek (Trigonella foenum graecum) seed extract prevents ethanol-induced toxicity and apoptosis in Chang liver cells.

    PubMed

    Kaviarasan, Subramanian; Ramamurty, Nalini; Gunasekaran, Palani; Varalakshmi, Elango; Anuradha, Carani Venkatraman

    2006-01-01

    The protective effect of a polyphenolic extract of fenugreek seeds (FPEt) against ethanol (EtOH)-induced toxicity was investigated in human Chang liver cells. Cells were incubated with either 30 mM EtOH alone or together in the presence of seed extract for 24 h. Assays were performed in treated cells to evaluate the ability of seeds to prevent the toxic effects of EtOH. EtOH treatment suppressed the growth of Chang liver cells and induced cytotoxicity, oxygen radical formation and mitochondrial dysfunction. Reduced glutathione (GSH) concentration was decreased significantly (P < 0.05) while oxidized glutathione (GSSG) concentration was significantly elevated in EtOH-treated cells as compared with normal cells. Incubation of FPEt along with EtOH significantly increased cell viability in a dose-dependent manner, caused a reduction in lactate dehydrogenase leakage and normalized GSH/GSSG ratio. The extract dose-dependently reduced thiobarbituric acid reactive substances formation. Apoptosis was observed in EtOH-treated cells while FPEt reduced apoptosis by decreasing the accumulation of sub-G1 phase cells. The cytoprotective effects of FPEt were comparable with those of a positive control silymarin, a known hepatoprotective agent. The findings suggest that the polyphenolic compounds of fenugreek seeds can be considered cytoprotective during EtOH-induced liver damage. PMID:16574673

  16. Resveratrol prevents rapamycin-induced upregulation of autophagy and selectively induces apoptosis in TSC2-deficient cells

    PubMed Central

    Alayev, Anya; Sun, Yang; Snyder, Rose B; Berger, Sara Malka; Yu, Jane J; Holz, Marina K

    2014-01-01

    The mammalian/mechanistic target of rapamycin complex 1 (mTORC1) signaling pathway is hyperactivated in a variety of cancers and disorders, including lymphangioleiomyomatosis (LAM) and tuberous sclerosis complex (TSC), which are characterized by mutations in tumor suppressors TSC1 or TSC2. The concern with the use of mTORC1 inhibitors, such as rapamycin or its analogs (rapalogs), is that they cause upregulation of autophagy and suppress the negative feedback loop to Akt, which promotes cell survival, causing the therapy to be only partially effective, and relapse occurs upon cessation of treatment. In this study, we investigate the use of rapamycin in combination with resveratrol, a naturally occurring polyphenol, in TSC2-deficient cells. We tested whether such combination would prevent rapamycin-induced upregulation of autophagy and shift the cell fate toward apoptosis. We found that this combination treatment blocked rapamycin-induced upregulation of autophagy and restored inhibition of Akt. Interestingly, the combination of rapamycin and resveratrol selectively promoted apoptosis of TSC2-deficient cells. Thus, the addition of resveratrol to rapamycin treatment may be a promising option for selective and targeted therapy for diseases with TSC loss and mTORC1 hyperactivation. PMID:24304514

  17. Fibronectin prevents endotoxin shock after partial hepatectomy in rats via inhibition of nuclear factor-kappaB and apoptosis.

    PubMed

    Kwon, A-Hon; Qiu, Zeyu; Tsuji, Katsushige; Miyaso, Takeshi; Okumura, Tadayoshi

    2007-07-01

    Fibronectins (Fns) are involved in a number of biologic processes, such as cellular adhesion, motility, differentiation, apoptosis, hemostasis, wound healing, and ischemic injury. We investigated the possible mechanism underlying the protective action of plasma Fn (pFn) on endotoxin shock following partial hepatectomy in rats. Lipopolysaccharide (LPS) was administered intravenously to male Sprague-Dawley rats within 48 hrs of 70% hepatectomy. Prior to LPS administration, pFn or human serum albumin was given intravenously. The survival rate of the pFn-treated group was improved markedly compared with that of the controls. The levels of inflammatory cytokines and nitric oxide (NO) in serum were significantly lower in the pFn-treated group than in the control group. Expression of inducible nitric oxide synthase (iNOS) in hepatocytes also was reduced following pFn treatment. The degree of apoptosis and necrosis in the remnant liver was significantly lower in the pFn-treated rats than the controls. Furthermore, pFn pretreatment greatly inhibited the activation of nuclear factor-kappaB (NF-kappaB), caspase 3 and 8 activities, and cytochrome c release, and caused a decrease in mitochondrial Bcl-x(L). Plasma Fn prevents endotoxin-induced liver injury at least in part through inhibition of NF-kappaB activation, which causes the reduction of iNOS expression and NO production by hepatocytes, and through the downregulation of inflammatory cytokines and promotion of Bcl-x(L) expression. PMID:17609505

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-01-01

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

  20. Depletion of cellular poly (A) binding protein prevents protein synthesis and leads to apoptosis in HeLa cells

    SciTech Connect

    Thangima Zannat, Mst.; Bhattacharjee, Rumpa B.; Bag, Jnanankur

    2011-05-13

    Highlights: {yields} Depletion of cellular PABP level arrests mRNA translation in HeLa cells. {yields} PABP knock down leads to apoptotic cell death. {yields} PABP depletion does not affect transcription. {yields} PABP depletion does not lead to nuclear accumulation of mRNA. -- Abstract: The cytoplasmic poly (A) binding protein (PABP) is important in mRNA translation and stability. In yeast, depletion of PABP leads to translation arrest. Similarly, the PABP gene in Drosophila is important for proper development. It is however uncertain, whether mammalian PABP is essential for mRNA translation. Here we showed the effect of PABP depletion on mRNA metabolism in HeLa cells by using a small interfering RNA. Our results suggest that depletion of PABP prevents protein synthesis and consequently leads to cell death through apoptosis. Interestingly, no detectable effect of PABP depletion on transcription, transport and stability of mRNA was observed.

  1. Cellular inhibitor of apoptosis proteins prevent clearance of hepatitis B virus

    PubMed Central

    Ebert, Gregor; Preston, Simon; Allison, Cody; Cooney, James; Toe, Jesse G.; Stutz, Michael D.; Ojaimi, Samar; Scott, Hamish W.; Baschuk, Nikola; Nachbur, Ueli; Torresi, Joseph; Chin, Ruth; Colledge, Danielle; Li, Xin; Warner, Nadia; Revill, Peter; Bowden, Scott; Silke, John; Begley, C. Glenn; Pellegrini, Marc

    2015-01-01

    Hepatitis B virus (HBV) infection can result in a spectrum of outcomes from immune-mediated control to disease progression, cirrhosis, and liver cancer. The host molecular pathways that influence and contribute to these outcomes need to be defined. Using an immunocompetent mouse model of chronic HBV infection, we identified some of the host cellular and molecular factors that impact on infection outcomes. Here, we show that cellular inhibitor of apoptosis proteins (cIAPs) attenuate TNF signaling during hepatitis B infection, and they restrict the death of infected hepatocytes, thus allowing viral persistence. Animals with a liver-specific cIAP1 and total cIAP2 deficiency efficiently control HBV infection compared with WT mice. This phenotype was partly recapitulated in mice that were deficient in cIAP2 alone. These results indicate that antagonizing the function of cIAPs may promote the clearance of HBV infection. PMID:25902529

  2. Cellular inhibitor of apoptosis proteins prevent clearance of hepatitis B virus.

    PubMed

    Ebert, Gregor; Preston, Simon; Allison, Cody; Cooney, James; Toe, Jesse G; Stutz, Michael D; Ojaimi, Samar; Scott, Hamish W; Baschuk, Nikola; Nachbur, Ueli; Torresi, Joseph; Chin, Ruth; Colledge, Danielle; Li, Xin; Warner, Nadia; Revill, Peter; Bowden, Scott; Silke, John; Begley, C Glenn; Pellegrini, Marc

    2015-05-01

    Hepatitis B virus (HBV) infection can result in a spectrum of outcomes from immune-mediated control to disease progression, cirrhosis, and liver cancer. The host molecular pathways that influence and contribute to these outcomes need to be defined. Using an immunocompetent mouse model of chronic HBV infection, we identified some of the host cellular and molecular factors that impact on infection outcomes. Here, we show that cellular inhibitor of apoptosis proteins (cIAPs) attenuate TNF signaling during hepatitis B infection, and they restrict the death of infected hepatocytes, thus allowing viral persistence. Animals with a liver-specific cIAP1 and total cIAP2 deficiency efficiently control HBV infection compared with WT mice. This phenotype was partly recapitulated in mice that were deficient in cIAP2 alone. These results indicate that antagonizing the function of cIAPs may promote the clearance of HBV infection. PMID:25902529

  3. The Mood-Stabilizer Lithium Prevents Hippocampal Apoptosis and Improves Spatial Memory in Experimental Meningitis

    PubMed Central

    Liechti, Fabian D.; Stüdle, Nicolas; Theurillat, Regula; Grandgirard, Denis; Thormann, Wolfgang; Leib, Stephen L.

    2014-01-01

    Pneumococcal meningitis is associated with high morbidity and mortality rates. Brain damage caused by this disease is characterized by apoptosis in the hippocampal dentate gyrus, a morphological correlate of learning deficits in experimental paradigms. The mood stabilizer lithium has previously been found to attenuate brain damage in ischemic and inflammatory diseases of the brain. An infant rat model of pneumococcal meningitis was used to investigate the neuroprotective and neuroregenerative potential of lithium. To assess an effect on the acute disease, LiCl was administered starting five days prior to intracisternal infection with live Streptococcus pneumoniae. Clinical parameters were recorded, cerebrospinal fluid (CSF) was sampled, and the animals were sacrificed 42 hours after infection to harvest the brain and serum. Cryosections of the brains were stained for Nissl substance to quantify brain injury. Hippocampal gene expression of Bcl-2, Bax, p53, and BDNF was analyzed. Lithium concentrations were measured in serum and CSF. The effect of chronic lithium treatment on spatial memory function and cell survival in the dentate gyrus was evaluated in a Morris water maze and by quantification of BrdU incorporation after LiCl treatment during 3 weeks following infection. In the hippocampus, LiCl significantly reduced apoptosis and gene expression of Bax and p53 while it increased expression of Bcl-2. IL-10, MCP-1, and TNF were significantly increased in animals treated with LiCl compared to NaCl. Chronic LiCl treatment improved spatial memory in infected animals. The mood stabilizer lithium may thus be a therapeutic alternative to attenuate neurofunctional deficits as a result of pneumococcal meningitis. PMID:25409333

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

    SciTech Connect

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

    2011-08-15

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

  5. The transcription-independent mitochondrial p53 program is a major contributor to nutlin-induced apoptosis in tumor cells

    PubMed Central

    Vaseva, Angelina V.; Marchenko, Natalia D.; Moll, Ute M.

    2010-01-01

    Strategies to induce p53 activation in tumors that retain wild-type p53 are promising for cancer therapy. Nutlin is a potent and selective pharmacological MDM2 inhibitor that competitively binds to its p53-binding pocket, thereby leading to non-genotoxic p53 stabilization and activation of growth arrest and apoptosis pathways. Nutlin-induced apoptosis is thought to occur via p53’s transcriptional program. Here we report that the transcription-independent mitochondrial p53 program plays an important role in Nutlin-induced p53-mediated tumor cell death. Aside from nuclear stabilization, Nutlin causes cytoplasmic p53 accumulation and translocation to mitochondria. Monoubiquitinated p53, originating from a distinct cytoplasmic pool, is the preferred p53 species that translocates to mitochondria in response to stress. Nutlin does not interfere with MDM2’s ability to monoubiquitinate p53, due to the fact that MDM2-p53 complexes are only partially disrupted and that Nutlin-stabilized MDM2 retains its E3 ubiquitin ligase activity. Nutlin-induced mitochondrial p53 translocation is rapid and associated with cytochrome C release that precedes induction of p53 target genes. Specific inhibition of mitochondrial p53 translocation by Pifithrin μ reduces the apoptotic Nutlin response by 2.5-fold, underlining the significance of p53’s mitochondrial program in Nutlin-induced apoptosis. Surprisingly, blocking the transcriptional arm of p53, either via α-Amanitin or the p53-specific transcriptional inhibitor Pifithrin α, not only fails to inhibit, but greatly potentiates Nutlin-induced apoptosis. In sum, the direct mitochondrial program is a major mechanism in Nutlin-induced p53-mediated apoptosis. Moreover, at least in some tumors the transcriptional p53 activities in net balance not only are dispensable for the apoptotic Nutlin response, but appear to actively block its therapeutic effect. PMID:19411846

  6. The transcription-independent mitochondrial p53 program is a major contributor to nutlin-induced apoptosis in tumor cells.

    PubMed

    Vaseva, Angelina V; Marchenko, Natalia D; Moll, Ute M

    2009-06-01

    Strategies to induce p53 activation in tumors that retain wild-type p53 are promising for cancer therapy. Nutlin is a potent and selective pharmacological MDM2 inhibitor that competitively binds to its p53-binding pocket, thereby leading to non-genotoxic p53 stabilization and activation of growth arrest and apoptosis pathways. Nutlin-induced apoptosis is thought to occur via p53's transcriptional program. Here we report that the transcription-independent mitochondrial p53 program plays an important role in Nutlin-induced p53-mediated tumor cell death. Aside from nuclear stabilization, Nutlin causes cytoplasmic p53 accumulation and translocation to mitochondria. Monoubiquitinated p53, originating from a distinct cytoplasmic pool, is the preferred p53 species that translocates to mitochondria in response to stress. Nutlin does not interfere with MDM2's ability to monoubiquitinate p53, due to the fact that MDM2-p53 complexes are only partially disrupted and that Nutlin-stabilized MDM2 retains its E3 ubiquitin ligase activity. Nutlin-induced mitochondrial p53 translocation is rapid and associated with cytochrome C release that precedes induction of p53 target genes. Specific inhibition of mitochondrial p53 translocation by Pifithrin mu reduces the apoptotic Nutlin response by 2.5-fold, underlining the significance of p53's mitochondrial program in Nutlin-induced apoptosis. Surprisingly, blocking the transcriptional arm of p53, either via alpha-Amanitin or the p53-specific transcriptional inhibitor Pifithrin alpha, not only fails to inhibit, but greatly potentiates Nutlin-induced apoptosis. In sum, the direct mitochondrial program is a major mechanism in Nutlin-induced p53-mediated apoptosis. Moreover, at least in some tumors the transcriptional p53 activities in net balance not only are dispensable for the apoptotic Nutlin response, but appear to actively block its therapeutic effect. PMID:19411846

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

    PubMed

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

    2015-08-21

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

  8. Lithium Treatment Prevents Apoptosis in Neonatal Rat Hippocampus Resulting from Sevoflurane Exposure.

    PubMed

    Zhou, Xue; da Li, Wen-; Yuan, Bao-Long; Niu, Li-Jun; Yang, Xiao-Yu; Zhou, Zhi-Bin; Chen, Xiao-Hui; Feng, Xia

    2016-08-01

    We aimed to observe the therapeutic effects of lithium on inhalational anesthetic sevoflurane-induced apoptosis in immature brain hippocampus. From postnatal day 5 (P5) to P28, male Sprague-Dawley pups were intraperitoneally injected with lithium chloride or 0.9 % sodium chloride. On P7 after the injection, pups were exposed to 2.3 % sevoflurane or air for 6 h. Brain tissues were harvested 12 h and 3 weeks after exposure. Cleaved caspase-3, nNOS protein, GSK-3β,p-GSK-3β were assessed by Western blot, and histopathological changes were assessed using Nissl stain and TUNEL stain. From P28, we used the eight-arm radial maze test and step-through test to evaluate the influence of sevoflurane exposure on the learning and memory of juvenile rats. The results showed that neonatal sevoflurane exposure induced caspase-3 activation and histopathological changes in hippocampus can be attenuated by lithium chloride. Sevoflurane increased GSK-3β activity while pretreatment of lithium decreased GSK-3β activity. Moreover, sevoflurane showed possibly slight but temporal influence on the spatial learning and the memory of juvenile rats, and chronic use of lithium chloride might have the therapeutic effect. Our current study suggests that lithium attenuates sevoflurane induced neonatal hippocampual damage by GSK-3β pathway and might improve learning and memory deficits in rats after neonatal exposure. PMID:27068032

  9. Chk1 and p21 Cooperate to Prevent Apoptosis during DNA Replication Fork StressD⃞

    PubMed Central

    Rodriguez, Rene; Meuth, Mark

    2006-01-01

    Cells respond to DNA replication stress by triggering cell cycle checkpoints, repair, or death. To understand the role of the DNA damage response pathways in determining whether cells survive replication stress or become committed to death, we examined the effect of loss of these pathways on cellular response to agents that slow or arrest DNA synthesis. We show that replication inhibitors such as excess thymidine, hydroxyurea, and camptothecin are normally poor inducers of apoptosis. However, these agents become potent inducers of death in S-phase cells upon small interfering RNA-mediated depletion of the checkpoint kinase Chk1. This death response is independent of p53 and Chk2. p21-deficient cells, on the other hand, produce a more robust apoptotic response upon Chk1 depletion. p21 is normally induced only late after thymidine treatment. In Chk1-depleted cells p21 induction occurs earlier and does not require p53. Thus, Chk1 plays a primary role in the protection of cells from death induced by replication fork stress, whereas p21 mediates through its role in regulating entry into S phase. These findings are of potential importance to cancer therapy because we demonstrate that the efficacy of clinically relevant agents can be enhanced by manipulation of these signaling pathways. PMID:16280359

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

    PubMed

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

    2015-04-01

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

  11. Prevention of Glucocorticoid Induced-Apoptosis of Osteoblasts and Osteocytes by Protecting against Endoplasmic Reticulum (ER) Stress in vitro and in vivo in Female Mice

    PubMed Central

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

    2014-01-01

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

  12. GVS-111 prevents oxidative damage and apoptosis in normal and Down's syndrome human cortical neurons.

    PubMed

    Pelsman, Alejandra; Hoyo-Vadillo, Carlos; Gudasheva, Tatiana A; Seredenin, Sergei B; Ostrovskaya, Rita U; Busciglio, Jorge

    2003-05-01

    The neuroprotective activity of a novel N-acylprolyl-containing dipeptide analog of the nootropic 2-oxo-1-pyrrolidine acetamide (Piracetam) designated as GVS-111 (DVD-111/Noopept) was tested in two in vitro models of neuronal degeneration mediated by oxidative stress: normal human cortical neurons treated with H(2)O(2), and Down's syndrome (DS) cortical neurons. Incubation of normal cortical neurons with 50 microM H(2)O(2) for 1h resulted in morphological and structural changes consistent with neuronal apoptosis and in the degeneration of more than 60% of the neurons present in the culture. GVS-111 significantly increased neuronal survival after H(2)O(2)-treatment displaying a dose-dependent neuroprotective activity from 10nM to 100 microM, and an IC(50) value of 1.21+/-0.07 microM. GVS-111 inhibited the accumulation of intracellular free radicals and lipid peroxidation damage in neurons treated with H(2)O(2) or FeSO(4), suggesting an antioxidant mechanism of action. GVS-111 exhibited significantly higher neuroprotection compared to the standard cognition enhancer Piracetam, or to the antioxidants Vitamin E, propyl gallate and N-tert-butyl-2-sulpho-phenylnitrone (s-PBN). In DS cortical cultures, chronic treatment with GVS-111 significantly reduced the appearance of degenerative changes and enhanced neuronal survival. The results suggest that the neuroprotective effect of GVS-111 against oxidative damage and its potential nootropic activity may present a valuable therapeutic combination for the treatment of mental retardation and chronic neurodegenerative disorders. PMID:12711349

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

    PubMed

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

    2016-09-16

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

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

    SciTech Connect

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

    2009-02-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

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

    PubMed

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

    2015-12-01

    Ilex latifolia Thunb. (Aquifoliaceae), a Chinese bitter tea called "kudingcha," has been widely consumed as a health beverage and found to possess antioxidant, antidiabetic, antihypertensive, anti-inflammatory, and anti-ischemic activities. The aim of the present study was to investigate the neuroprotective effects of an ethanol extract of I. latifolia against amyloid β protein (Aβ)-induced memory impairment in mice and neurotoxicity in cultured rat cortical neurons. Memory impairment in mice was induced by intracerebroventricular injection of 15 nmol Aβ (25-35) and measured by the passive avoidance test and Morris water maze test. Chronic administration of I. latifolia (25-100 mg/kg, p.o.) significantly prevented Aβ (25-35)-induced memory loss. I. latifolia also prevented the decrease of glutathione concentrations, increased lipid peroxidation, expression of phosphorylated tau (p-tau), and changes in apoptosis-associated proteins in the memory-impaired mouse brain. Exposure of cultured cortical neurons to 10 μM Aβ (25-35) for 36 h induced neuronal apoptotic death. The neuronal cell death, elevation of intracellular Ca(2+) concentration, generation of reactive oxygen species, and expression of proapoptotic proteins caused by Aβ (25-35) in the cultured neurons were inhibited by treatment with I. latifolia (1-50 μg/mL). These results suggest that I. latifolia may have a possible therapeutic role in managing cognitive impairment associated with Alzheimer's disease. The underlying mechanism might involve the antiapoptotic effects mediated by antioxidant activity and inhibition of p-tau formation. PMID:26291170

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

    PubMed Central

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

    2015-01-01

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

  19. Brain-derived Neurotrophic Factor Prevents Phencyclidine-induced Apoptosis in Developing Brain by Parallel Activation of both the ERK and PI-3K/Akt Pathways

    PubMed Central

    Xia, Yan; Wang, Cheng Z.; Liu, Jie; Anastasio, Noelle C.; Johnson, Kenneth M.

    2009-01-01

    Summary Phencyclidine is an N-methyl D-aspartate receptor (NMDAR) blocker that has been reported to induce neuronal apoptosis during development and schizophrenia-like behaviors in rats later in life. Brain derived neurotrophic factor (BDNF) has been shown to prevent neuronal death caused by NMDAR blockade, but the precise mechanism is unknown. This study examined the role of the phosphatidylinositol-3 kinase (PI3K)/Akt and extracellular signal-regulated kinase (ERK) pathways in BDNF protection of PCP-induced apoptosis in corticostriatal organotypic cultures. It was observed that BDNF inhibited PCP-induced apoptosis in a concentration dependent fashion. BDNF effectively prevented PCP-induced inhibition of the ERK and PI-3K/Akt pathways and suppressed GSK-3β activation. Blockade of either PI-3K/Akt or ERK activation abolished BDNF protection. Western blot analysis revealed that the PI-3K inhibitor LY294002 prevented the stimulating effect of BDNF on the PI-3K/Akt pathway, but had no effect on the ERK pathway. Similarly, the ERK inhibitor PD98059 prevented the stimulating effect of BDNF on the ERK pathway, but not the PI-3K/Akt pathway. Co-application of LY294002 and PD98059 had no additional effect on BDNF-evoked activation of Akt or ERK. However, concurrent exposure to PD98059 and LY294002 caused much greater inhibition of BDNF-evoked phosphorylation of GSK-3β at serine 9 than did LY294002 alone. Finally, either BDNF or GSK-3β inhibition prevented PCP-induced suppression of cyclic-AMP response element binding protein (CREB) phosphorylation. These data demonstrate that the protective effect of BDNF against PCP-induced apoptosis is mediated by parallel activation of the PI-3K/Akt and ERK pathways, most likely involves inhibition of GSK-3β and activation of CREB. PMID:19887077

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

    PubMed

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

    2016-03-01

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

  1. Rapamycin ameliorates cadmium-induced activation of MAPK pathway and neuronal apoptosis by preventing mitochondrial ROS inactivation of PP2A.

    PubMed

    Xu, Chong; Wang, Xiaoxue; Zhu, Yu; Dong, Xiaoqing; Liu, Chunxiao; Zhang, Hai; Liu, Lei; Huang, Shile; Chen, Long

    2016-06-01

    Cadmium (Cd) is a highly toxic metal that affects the central nervous system. Recently we have demonstrated that inhibition of mTOR by rapamycin rescues neuronal cells from Cd-poisoning. Here we show that rapamycin inhibited Cd-induced mitochondrial ROS-dependent neuronal apoptosis. Intriguingly, rapamycin remarkably blocked phosphorylation of JNK, Erk1/2 and p38 in neuronal cells induced by Cd, which was strengthened by co-treatment with Mito-TEMPO. Inhibition of JNK and Erk1/2 by SP600125 and U0126, respectively, potentiated rapamycin's prevention from Cd-induced apoptosis. Consistently, over-expression of dominant negative c-Jun or MKK1 also potently improved the inhibitory effect of rapamycin on Cd neurotoxicity. Furthermore, pretreatment with SP600125 or U0126, or expression of dominant negative c-Jun or MKK1 enhanced the inhibitory effects of rapamycin or Mito-TEMPO on Cd-induced ROS. Further investigation found that co-treatment with Mito-TEMPO/rapamycin more effectively rescued cells by preventing Cd inactivation of PP2A than treatment with rapamycin or Mito-TEMPO alone. Over-expression of wild-type PP2A reinforced rapamycin or Mito-TEMPO suppression of activated JNK and Erk1/2 pathways, as well as ROS production and apoptosis in neuronal cells in response to Cd. The findings indicate that rapamycin ameliorates Cd-evoked neuronal apoptosis by preventing mitochondrial ROS inactivation of PP2A, thereby suppressing activation of JNK and Erk1/2 pathways. Our results underline that rapamycin may have a potential in preventing Cd-induced oxidative stress and neurodegenerative diseases. PMID:26805420

  2. A novel peptide, colivelin, prevents alcohol-induced apoptosis in fetal brain of C57BL/6 mice: signaling pathway investigations

    PubMed Central

    Sari, Youssef; Chiba, Tomohiro; Yamada, Marina; Rebec, George V.; Aiso, Sadakazu

    2009-01-01

    Fetal alcohol exposure is known to induce cell death through apoptosis. We found that colivelin (CLN), a novel peptide with the sequence SALLRSIPAPAGASRLLLLTGEIDLP, prevents this apoptosis. Our initial experiment revealed that CLN enhanced the viability of primary cortical neurons exposed to alcohol. We then used a mouse model of fetal alcohol exposure to identify the intracellular mechanisms underlying these neuroprotective effects. On embryonic day 7 (E7), weight-matched pregnant females were assigned to the following groups: (1) ethanol liquid diet (ALC) 25% (4.49%, v/v) ethanol derived calories; (2) pair-fed control; (3) normal chow; (4) ALC combined with administration (i.p.) of CLN (20 μg/20 g body weight); and (5) pair-fed combined with administration (i.p.) of CLN (20 μg/20 g body weight). On E13, fetal brains were collected and assayed for TUNEL staining, caspase-3 colorimetric assay, ELISA, and MSD electrochemiluminescence. CLN blocked the alcohol-induced decline in brain weight and prevented alcohol-induced: apoptosis, activation of caspase-3 and increases of cytosolic cytochrome c, and decreases of mitochondrial cytochrome c. Analysis of proteins in the upstream signaling pathway revealed that CLN down-regulated the phosphorylation of the c-Jun N-terminal kinase. Moreover, CLN prevented alcohol-induced reduction in phosphorylation of BAD protein. Thus, CLN appears to act directly on upstream signaling proteins to prevent alcohol-induced apoptosis. Further assessment of these proteins and their signaling mechanisms is likely to enhance development of neuroprotective therapies. PMID:19782727

  3. Saponin-rich fraction from Clematis chinensis Osbeck roots protects rabbit chondrocytes against nitric oxide-induced apoptosis via preventing mitochondria impairment and caspase-3 activation.

    PubMed

    Wu, Wenjun; Gao, Xinghua; Xu, Xianxiang; Luo, Yubin; Liu, Mei; Xia, Yufeng; Dai, Yue

    2013-03-01

    Our previous study reported that the saponin-rich fraction from Clematis chinensis Osbeck roots (SFC) could effectively alleviate experimental osteoarthritis induced by monosodium iodoacetate in rats through protecting articular cartilage and inhibiting local inflammation. The present study was performed to investigate the preventive effects of SFC on articular chondrocyte, and explore the underlying mechanisms. Primary rabbit chondrocytes were cultured and exposed to sodium nitroprusside (SNP), a NO donor. After treatment with different concentrations of SFC (30, 100, 300, 1,000 μg/ml) for 24 h, nucleic morphology, apoptotic rate, mitochondrial function and caspase-3 activity of chondrocytes were examined. The results showed that SNP induced remarkable apoptosis of rabbit chondrocytes evidenced by Hoechst 33258 staining and flow cytometry analysis, and SFC prevented the apoptosis in a concentration-dependent manner. Further studies indicated that SFC could prevent the depolarization of mitochondrial membrane potential (∆ψm) in SNP-treated chondrocytes and suppress the activation of caspase-3. It can be concluded that the protection of SFC on articular chondrocytes is associated with the anti-apoptosis effects via inhibiting the mitochondrion impairment and caspase-3 activation. PMID:22821055

  4. Haploinsufficiency for Core Exon Junction Complex Components Disrupts Embryonic Neurogenesis and Causes p53-Mediated Microcephaly.

    PubMed

    Mao, Hanqian; McMahon, John J; Tsai, Yi-Hsuan; Wang, Zefeng; Silver, Debra L

    2016-09-01

    The exon junction complex (EJC) is an RNA binding complex comprised of the core components Magoh, Rbm8a, and Eif4a3. Human mutations in EJC components cause neurodevelopmental pathologies. Further, mice heterozygous for either Magoh or Rbm8a exhibit aberrant neurogenesis and microcephaly. Yet despite the requirement of these genes for neurodevelopment, the pathogenic mechanisms linking EJC dysfunction to microcephaly remain poorly understood. Here we employ mouse genetics, transcriptomic and proteomic analyses to demonstrate that haploinsufficiency for each of the 3 core EJC components causes microcephaly via converging regulation of p53 signaling. Using a new conditional allele, we first show that Eif4a3 haploinsufficiency phenocopies aberrant neurogenesis and microcephaly of Magoh and Rbm8a mutant mice. Transcriptomic and proteomic analyses of embryonic brains at the onset of neurogenesis identifies common pathways altered in each of the 3 EJC mutants, including ribosome, proteasome, and p53 signaling components. We further demonstrate all 3 mutants exhibit defective splicing of RNA regulatory proteins, implying an EJC dependent RNA regulatory network that fine-tunes gene expression. Finally, we show that genetic ablation of one downstream pathway, p53, significantly rescues microcephaly of all 3 EJC mutants. This implicates p53 activation as a major node of neurodevelopmental pathogenesis following EJC impairment. Altogether our study reveals new mechanisms to help explain how EJC mutations influence neurogenesis and underlie neurodevelopmental disease. PMID:27618312

  5. CaMKII inhibition in type II pneumocytes protects from bleomycin-induced pulmonary fibrosis by preventing Ca2+-dependent apoptosis.

    PubMed

    Winters, Christopher J; Koval, Olha; Murthy, Shubha; Allamargot, Chantal; Sebag, Sara C; Paschke, John D; Jaffer, Omar A; Carter, A Brent; Grumbach, Isabella M

    2016-01-01

    The calcium and calmodulin-dependent kinase II (CaMKII) translates increases in intracellular Ca(2+) into downstream signaling events. Its function in pulmonary pathologies remains largely unknown. CaMKII is a well-known mediator of apoptosis and regulator of endoplasmic reticulum (ER) Ca(2+). ER stress and apoptosis of type II pneumocytes lead to aberrant tissue repair and progressive collagen deposition in pulmonary fibrosis. Thus we hypothesized that CaMKII inhibition alleviates fibrosis in response to bleomycin by attenuating apoptosis and ER stress of type II pneumocytes. We first established that CaMKII was strongly expressed in the distal respiratory epithelium, in particular in surfactant protein-C-positive type II pneumocytes, and activated after bleomycin instillation. We generated a novel transgenic model of inducible expression of the CaMKII inhibitor peptide AC3-I limited to type II pneumocytes (Tg SPC-AC3-I). Tg SPC-AC3-I mice were protected from development of pulmonary fibrosis after bleomycin exposure compared with wild-type mice. CaMKII inhibition also provided protection from apoptosis in type II pneumocytes in vitro and in vivo. Moreover, intracellular Ca(2+) levels and ER stress were increased by bleomycin and significantly blunted with CaMKII inhibition in vitro. These data demonstrate that CaMKII inhibition prevents type II pneumocyte apoptosis and development of pulmonary fibrosis in response to bleomycin. CaMKII inhibition may therefore be a promising approach to prevent or ameliorate the progression of pulmonary fibrosis. PMID:26545899

  6. Brca1 is required for embryonic development of the mouse cerebral cortex to normal size by preventing apoptosis of early neural progenitors.

    PubMed

    Pulvers, Jeremy N; Huttner, Wieland B

    2009-06-01

    The extent of apoptosis of neural progenitors is known to influence the size of the cerebral cortex. Mouse embryos lacking Brca1, the ortholog of the human breast cancer susceptibility gene BRCA1, show apoptosis in the neural tube, but the consequences of this for brain development have not been studied. Here we investigated the role of Brca1 during mouse embryonic cortical development by deleting floxed Brca1 using Emx1-Cre, which leads to conditional gene ablation specifically in the dorsal telencephalon after embryonic day (E) 9.5. The postnatal Brca1-ablated cerebral cortex was substantially reduced in size with regard to both cortical thickness and surface area. Remarkably, although the thickness of the cortical layers (except for the upper-most layer) was decreased, cortical layering as such was essentially unperturbed. High levels of apoptosis were found at E11.5 and E13.5, but dropped to near-control levels by E16.5. The apoptosis at the early stage of neurogenesis occurred in both BrdU pulse-labeled neural progenitors and the neurons derived therefrom. No changes were observed in the mitotic index of apical (neuroepithelial, radial glial) progenitors and basal (intermediate) progenitors, indicating that Brca1 ablation did not affect cell cycle progression. Brca1 ablation did, however, result in the nuclear translocation of p53 in neural progenitors, suggesting that their apoptosis involved activation of the p53 pathway. Our results show that Brca1 is required for the cerebral cortex to develop to normal size by preventing the apoptosis of early cortical progenitors and their immediate progeny. PMID:19403657

  7. Inhibitor of apoptosis-stimulating protein of p53 (iASPP) prevents senescence and is required for epithelial stratification

    PubMed Central

    Notari, Mario; Hu, Ying; Koch, Sofia; Lu, Min; Ratnayaka, Indrika; Zhong, Shan; Baer, Caroline; Pagotto, Anna; Goldin, Robert; Salter, Victoria; Candi, Eleonora; Melino, Gerry; Lu, Xin

    2011-01-01

    Inhibitor of apoptosis-stimulating protein of p53 (iASPP) is the most ancient member of the ASPP family of proteins and an evolutionarily conserved inhibitor of p53. iASPP is also a binding partner and negative regulator of p65RelA. Because p65RelA and the p53 family members often have opposite effects in controlling cell fate, it is important to understand the cellular context in which iASPP can regulate their activities. To address this question and to study the biological importance of iASPP in vivo, we generated a transgenic mouse in which iASPP expression is controlled by the Cre/loxP recombination system. We observed that iASPP is able to prevent premature cellular senescence in mouse embryonic fibroblasts. iASPP loss resulted in increased differentiation of primary keratinocytes both in vitro and in vivo. In stratified epithelia, nuclear iASPP often colocalized with p63 in the nuclei of basal keratinocytes. Consistent with this, iASPP bound p63 and inhibited the transcriptional activity of both TAp63α and ΔNp63α in vitro and influenced the expression level of p63-regulated genes such as loricrin and involucrin in vivo. In contrast, under the same conditions, p65RelA was frequently expressed as a cytoplasmic protein in the suprabasal layers of stratified epithelia and rarely colocalized with nuclear iASPP. Thus, iASPP is likely to control epithelial stratification by regulating p63's transcriptional activity, rather than p65RelA's. This study identifies iASPP as an inhibitor of senescence and a key player in controlling epithelial stratification. PMID:21930934

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

    PubMed Central

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

    2014-01-01

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

  9. Radiation-Induced Salivary Gland Dysfunction Results From p53-Dependent Apoptosis

    SciTech Connect

    Avila, Jennifer L.; Grundmann, Oliver; Burd, Randy; Limesand, Kirsten H.

    2009-02-01

    Purpose: Radiotherapy for head-and-neck cancer causes adverse secondary side effects in the salivary glands and results in diminished quality of life for the patient. A previous in vivo study in parotid salivary glands demonstrated that targeted head-and-neck irradiation resulted in marked increases in phosphorylated p53 (serine{sup 18}) and apoptosis, which was suppressed in transgenic mice expressing a constitutively active mutant of Akt1 (myr-Akt1). Methods and Materials: Transgenic and knockout mouse models were exposed to irradiation, and p53-mediated transcription, apoptosis, and salivary gland dysfunction were analyzed. Results: The proapoptotic p53 target genes PUMA and Bax were induced in parotid salivary glands of mice at early time points after therapeutic radiation. This dose-dependent induction requires expression of p53 because no radiation-induced expression of PUMA and Bax was observed in p53-/- mice. Radiation also induced apoptosis in the parotid gland in a dose-dependent manner, which was p53 dependent. Furthermore, expression of p53 was required for the acute and chronic loss of salivary function after irradiation. In contrast, apoptosis was not induced in p53-/- mice, and their salivary function was preserved after radiation exposure. Conclusions: Apoptosis in the salivary glands after therapeutic head-and-neck irradiation is mediated by p53 and corresponds to salivary gland dysfunction in vivo.

  10. EAF2 mediates germinal centre B-cell apoptosis to suppress excessive immune responses and prevent autoimmunity.

    PubMed

    Li, Yingqian; Takahashi, Yoshimasa; Fujii, Shin-ichiro; Zhou, Yang; Hong, Rongjian; Suzuki, Akari; Tsubata, Takeshi; Hase, Koji; Wang, Ji-Yang

    2016-01-01

    Regulated apoptosis of germinal centre (GC) B cells is critical for normal humoral immune responses. ELL-associated factor 2 (EAF2) regulates transcription elongation and has been shown to be an androgen-responsive potential tumour suppressor in prostate by inducing apoptosis. Here we show that EAF2 is selectively upregulated in GC B cells among various immune cell types and promotes apoptosis of GC B cells both in vitro and in vivo. EAF2 deficiency results in enlarged GCs and elevated antibody production during a T-dependent immune response. After immunization with type II collagen, mice lacking EAF2 produce high levels of collagen-specific autoantibodies and rapidly develop severe arthritis. Moreover, the mutant mice spontaneously produce anti-dsDNA, rheumatoid factor and anti-nuclear antibodies as they age. These results demonstrate that EAF2-mediated apoptosis in GC B cells limits excessive humoral immune responses and is important for maintaining self-tolerance. PMID:26935903

  11. Upregulation of lymphocyte apoptosis as a strategy for preventing and treating autoimmune disorders: a role for whole-food vegan diets, fish oil and dopamine agonists.

    PubMed

    McCarty, M F

    2001-08-01

    Induced apoptosis of autoreactive T-lymphocyte precursors in the thymus is crucial for the prevention of autoimmune disorders. IGF-I and prolactin, which are lymphocyte growth factors, may have the potential to suppress apoptosis in thymocytes and thus encourage autoimmunity; conversely, dietary fish oil rich in omega-3 fats appears to upregulate apoptosis in lymphocytes. Since whole-food vegan diets may downregulate systemic IGF-I activity, it is proposed that such a diet, in conjunction with fish oil supplementation and treatment with dopamine agonists capable of suppressing prolactin secretion, may have utility for treating and preventing autoimmune disorders. This prediction is consistent with the extreme rarity of autoimmune disorders among sub-Saharan black Africans as long as they followed their traditional quasi-vegan lifestyles, and with recent ecologic studies correlating risks for IDDM and for multiple sclerosis mortality with animal product and/or saturated fat consumption. Moreover, there is evidence that vegan or quasi-vegan diets are useful in the management of rheumatoid arthritis, multiple sclerosis, and possibly SLE. The dopamine agonist bromocryptine exerts anti-inflammatory effects in rodent models of autoimmunity, and there is preliminary evidence that this drug may be clinically useful in several human autoimmune diseases; better tolerated D2-specific agonists such as cabergoline may prove to be more practical for use in therapy. The moderate clinical utility of supplemental fish oil in rheumatoid arthritis and certain other autoimmune disorders is documented. It is not unlikely that extra-thymic anti-inflammatory effects contribute importantly to the clinical utility of vegan diets, bromocryptine, and fish oil in autoimmunity. The favorable impact of low latitude or high altitude on autoimmune risk may be mediated by superior vitamin D status, which is associated with decreased secretion of parathyroid hormone; there are theoretical grounds

  12. All-trans retinoic acid stimulates gene expression of the cardioprotective natriuretic peptide system and prevents fibrosis and apoptosis in cardiomyocytes of obese ob/ob mice.

    PubMed

    Manolescu, Daniel-Constantin; Jankowski, Marek; Danalache, Bogdan A; Wang, Donghao; Broderick, Tom L; Chiasson, Jean-Louis; Gutkowska, Jolanta

    2014-10-01

    In hypertensive rodents, retinoic acid (RA) prevents adverse cardiac remodelling and improves myocardial infarction outcome, but its role in obesity-related changes of cardiac tissue are unclear. We hypothesized that all-trans RA (ATRA) treatment will improve the cardioprotective oxytocin-natriuretic peptides (OT-NP) system, preventing apoptosis and collagen accumulation in hearts of ob/ob mice, a mouse model of obesity and insulin resistance. Female 9-week-old B6.V-Lep/J ob/ob mice (n = 16) were divided into 2 groups: 1 group (n = 8) treated with 100 μg of ATRA dissolved in 100 μL of corn oil (vehicle) delivered daily (∼2 μg·g body weight(-1)·day(-1)) by stomach intubation for 16 days, and 1 group (n = 8) that received the vehicle alone. A group of nonobese littermate mice (n = 9) served as controls. Ob/ob mice exhibited obesity, hyperglycaemia, and downregulation of the cardiac OT-NP system, including the mRNA for the transcription factor GATA4, OT receptor and brain NP, and the protein expression for endothelial nitric oxide synthase. Hearts from ob/ob mice also demonstrated increased apoptosis and collagen accumulation. ATRA treatment induced weight loss and decreased adipocytes diameter in the visceral fat, thus reducing visceral obesity, which is associated with a high risk for cardiovascular disease. RA treatment was associated with a reduction in hyperglycemia and a normalization of the OT-NP system's expression in the hearts of ob/ob mice. Furthermore, ATRA treatment prevented apoptosis and collagen accumulation in hearts of ob/ob mice. The present study indicates that ATRA treatment was effective in restoring the cardioprotective OT-NP system and in preventing abnormal cardiac remodelling in the ob/ob mice. PMID:25017112

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

    PubMed

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

    2013-06-01

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

  14. Myricitrin attenuates endothelial cell apoptosis to prevent atherosclerosis: An insight into PI3K/Akt activation and STAT3 signaling pathways.

    PubMed

    Qin, Meng; Luo, Yun; Meng, Xiang-bao; Wang, Min; Wang, Hong-wei; Song, Shi-yu; Ye, Jing-xue; Pan, Rui-le; Yao, Fan; Wu, Ping; Sun, Gui-bo; Sun, Xiao-bo

    2015-07-01

    Blood vessel endothelial dysfunction induced by oxidized low-density lipoprotein (ox-LDL) has been implicated in the pathogenesis of atherosclerosis and vasculopathy. The ox-LDL-elicited reactive oxygen species (ROS) release has been assumed to serve a critical function in endothelial damage. Myricitrin (from Myrica cerifera) is a natural antioxidant that has strong anti-oxidative, anti-inflammatory, and anti-nociceptive activities. However, the protective effect of myricitrin on ROS-induced endothelial cell injury and its related molecular mechanisms have never been investigated. This study demonstrates that myricitrin can inhibit ox-LDL-induced endothelial apoptosis and prevent plaque formation at an early stage in an atherosclerotic mouse model. The administration of myricitrin in vivo decreases the thickness of the vascular wall in the aortic arch of ApoE-/- mice. In vitro study shows that ox-LDL-induced human umbilical vein endothelial cell apoptosis can be reduced upon receiving myricitrin pre-treatment. Treatment with myricitrin significantly attenuated ox-LDL-induced endothelial cell apoptosis by inhibiting LOX-1 expression and by increasing the activation of the STAT3 and PI3K/Akt/eNOS signaling pathways. At the same time, our result demonstrates that myricitrin treatment optimizes the balance of pro/anti-apoptosis proteins, including Bax, Bad, XIAP, cIAP-2, and survivin. Our study suggests that myricitrin treatment can effectively protect cells from ox-LDL-induced endothelial cell apoptosis, which results in reduced atherosclerotic plaque formation. This result indicates that myricitrin can be used as a drug candidate for the treatment of cardiovascular diseases. PMID:25849952

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

    PubMed

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

    2011-10-01

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

  16. Novel function of CRTH2 in preventing apoptosis of human Th2 cells through activation of the phosphatidylinositol 3-kinase pathway.

    PubMed

    Xue, Luzheng; Barrow, Anna; Pettipher, Roy

    2009-06-15

    It is now well established that interaction of PGD(2) with chemoattractant receptor- homologous molecule expressed on Th2 cells (CRTH2) promotes chemotaxis and proinflammatory cytokine production by Th2 lymphocytes. In this study we show a novel function of CRTH2 in mediating an inhibitory effect of PGD(2) on the apoptosis of human Th2 cells induced by cytokine deprivation. This effect was mimicked by the selective CRTH2 agonist 13,14-dihydro-15-keto-PGD(2), inhibited by the CRTH2 antagonists ramatroban and TM30089, and not observed in CRTH2-negative T cells. D prostanoid receptor 1 (DP(1)) or the thromboxane-like prostanoid (TP) receptor did not play a role in mediating the effects of PGD(2) on the apoptosis of Th2 cells because neither the DP(1) antagonist BW868C nor the TP antagonist SQ29548 had any effect on the antiapoptotic effect of PGD(2). Apoptosis of Th2 cells induced by Fas ligation was not suppressed by treatment with PGD(2), illustrating that activation of CRTH2 only inhibits apoptosis induced by cytokine deprivation. Treatment with PGD(2) induced phosphorylation of Akt and BAD, prevented release of cytochrome c from mitochondria, and suppressed cleavage of caspase-3 and poly(ADP-ribose) polymerase in Th2 cells deprived of IL-2. The PI3K inhibitor LY294002 blocked the effect of PGD(2) both on the signaling events and on the apoptotic death of Th2 cells. These data suggest that in addition to promoting the recruitment and activation of Th2 cells, PGD(2) may also impede the resolution of allergic inflammation through inhibiting apoptosis of Th2 cells. PMID:19494281

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

    PubMed

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

    2007-01-01

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

  18. Inhibition of NOS-NO System Prevents Autoimmune Orchitis Development in Rats: Relevance of NO Released by Testicular Macrophages in Germ Cell Apoptosis and Testosterone Secretion

    PubMed Central

    Jarazo Dietrich, Sabrina; Fass, Mónica Irina; Jacobo, Patricia Verónica; Sobarzo, Cristian Marcelo Alejandro; Lustig, Livia; Theas, María Susana

    2015-01-01

    Background Although the testis is considered an immunoprivileged organ it can orchestrate immune responses against pathological insults such as infection and trauma. Experimental autoimmune orchitis (EAO) is a model of chronic inflammation whose main histopathological features it shares with human orchitis. In EAO an increased number of macrophages infiltrate the interstitium concomitantly with progressive germ cell degeneration and impaired steroidogenesis. Up-regulation of nitric oxide (NO)-NO synthase (NOS) system occurs, macrophages being the main producers of NO. Objective The aim of our study was to evaluate the role of NO-NOS system in orchitis development and determine the involvement of NO released by testicular macrophages on germ cell apoptosis and testosterone secretion. Method and Results EAO was induced in rats by immunization with testicular homogenate and adjuvants (E group) and a group of untreated normal rats (N) was also studied. Blockage of NOS by i.p. injection of E rats with a competitive inhibitor of NOS, L-NAME (8mg/kg), significantly reduced the incidence and severity of orchitis and lowered testicular nitrite content. L-NAME reduced germ cell apoptosis and restored intratesticular testosterone levels, without variations in serum LH. Co-culture of N testicular fragments with testicular macrophages obtained from EAO rats significantly increased germ cell apoptosis and testosterone secretion, whereas addition of L-NAME lowered both effects and reduced nitrite content. Incubation of testicular fragments from N rats with a NO donor DETA-NOnoate (DETA-NO) induced germ cell apoptosis through external and internal apoptotic pathways, an effect prevented by N-acetyl-L-cysteine (NAC). DETA-NO inhibited testosterone released from Leydig cells, whereas NAC (from 2.5 to 15 mM) did not prevent this effect. Conclusions We demonstrated that NO-NOS system is involved in the impairment of testicular function in orchitis. NO secreted mainly by testicular

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

    PubMed Central

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

    2016-01-01

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

  20. Taxifolin prevents diabetic cardiomyopathy in vivo and in vitro by inhibition of oxidative stress and cell apoptosis.

    PubMed

    Sun, Xiao; Chen, Rong-chang; Yang, Zhi-hong; Sun, Gui-bo; Wang, Min; Ma, Xiao-jun; Yang, Li-juan; Sun, Xiao-bo

    2014-01-01

    Diabetic cardiomyopathy has been increasingly recognized as an important cause of heart failure in diabetic patients. Excessive oxidative stress has been suggested to play a critical role in the development of diabetic cardiomyopathy. The objective of this study was to investigate the potential protective effects and mechanisms of taxifolin on cardiac function of streptozotocin-induced diabetic mice and on hyperglycemia-induced apoptosis of H9c2 cardiac myoblasts. In vivo study revealed that taxifolin improved diastolic dysfunction, ameliorated myocardium structure abnormality, inhibited myocyte apoptosis and enhanced endogenous antioxidant enzymes activities. Interestingly, taxifolin reduced angiotensin II level in myocardium, inhibited NADPH oxidase activity, and increased JAK/STAT3 activation. In vitro investigation demonstrated that taxifolin inhibited 33 mM glucoseinduced H9c2 cells apoptosis by decreasing intracellular ROS level. It also inhibited caspase-3 and caspase-9 activation, restored mitochondrial membrane potential, and regulated the expression of proteins related to the intrinsic pathway of apoptosis, thus inhibiting the release of cytochrome c from mitochondria into the cytoplasm. In conclusion, taxifolin exerted cardioprotective effects against diabetic cardiomyopathy by inhibiting oxidative stress and cardiac myocyte apoptosis and might be a potential agent in the treatment of diabetic cardiomyopathy. PMID:24269735

  1. MicroRNA-26a prevents endothelial cell apoptosis by directly targeting TRPC6 in the setting of atherosclerosis

    PubMed Central

    Zhang, Yong; Qin, Wei; Zhang, Longyin; Wu, Xianxian; Du, Ning; Hu, Yingying; Li, Xiaoguang; Shen, Nannan; Xiao, Dan; Zhang, Haiying; Li, Zhange; Zhang, Yue; Yang, Huan; Gao, Feng; Du, Zhimin; Xu, Chaoqian; Yang, Baofeng

    2015-01-01

    Atherosclerosis, a chronic inflammatory disease, is the major cause of life-threatening complications such as myocardial infarction and stroke. Endothelial apoptosis plays a vital role in the initiation and progression of atherosclerotic lesions. Although a subset of microRNAs (miRs) have been identified as critical regulators of atherosclerosis, studies on their participation in endothelial apoptosis in atherosclerosis have been limited. In our study, we found that miR-26a expression was substantially reduced in the aortic intima of ApoE−/− mice fed with a high-fat diet (HFD). Treatment of human aortic endothelial cells (HAECs) with oxidized low-density lipoprotein (ox-LDL) suppressed miR-26a expression. Forced expression of miR-26a inhibited endothelial apoptosis as evidenced by MTT assay and TUNEL staining results. Further analysis identified TRPC6 as a target of miR-26a, and TRPC6 overexpression abolished the anti-apoptotic effect of miR-26a. Moreover, the cytosolic calcium and the mitochondrial apoptotic pathway were found to mediate the beneficial effects of miR-26a on endothelial apoptosis. Taken together, our study reveals a novel role of miR-26a in endothelial apoptosis and indicates a therapeutic potential of miR-26a for atherosclerosis associated with apoptotic cell death. PMID:25801675

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

    PubMed

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

    2016-07-01

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

  3. MicroRNA-26a prevents endothelial cell apoptosis by directly targeting TRPC6 in the setting of atherosclerosis

    NASA Astrophysics Data System (ADS)

    Zhang, Yong; Qin, Wei; Zhang, Longyin; Wu, Xianxian; Du, Ning; Hu, Yingying; Li, Xiaoguang; Shen, Nannan; Xiao, Dan; Zhang, Haiying; Li, Zhange; Zhang, Yue; Yang, Huan; Gao, Feng; Du, Zhimin; Xu, Chaoqian; Yang, Baofeng

    2015-03-01

    Atherosclerosis, a chronic inflammatory disease, is the major cause of life-threatening complications such as myocardial infarction and stroke. Endothelial apoptosis plays a vital role in the initiation and progression of atherosclerotic lesions. Although a subset of microRNAs (miRs) have been identified as critical regulators of atherosclerosis, studies on their participation in endothelial apoptosis in atherosclerosis have been limited. In our study, we found that miR-26a expression was substantially reduced in the aortic intima of ApoE-/- mice fed with a high-fat diet (HFD). Treatment of human aortic endothelial cells (HAECs) with oxidized low-density lipoprotein (ox-LDL) suppressed miR-26a expression. Forced expression of miR-26a inhibited endothelial apoptosis as evidenced by MTT assay and TUNEL staining results. Further analysis identified TRPC6 as a target of miR-26a, and TRPC6 overexpression abolished the anti-apoptotic effect of miR-26a. Moreover, the cytosolic calcium and the mitochondrial apoptotic pathway were found to mediate the beneficial effects of miR-26a on endothelial apoptosis. Taken together, our study reveals a novel role of miR-26a in endothelial apoptosis and indicates a therapeutic potential of miR-26a for atherosclerosis associated with apoptotic cell death.

  4. Molecular Regulation of DNA Damage-Induced Apoptosis in Neurons of Cerebral Cortex

    PubMed Central

    Liu, Zhiping; Pipino, Jacqueline; Chestnut, Barry; Landek, Melissa A.

    2009-01-01

    Cerebral cortical neuron degeneration occurs in brain disorders manifesting throughout life, but the mechanisms are understood poorly. We used cultured embryonic mouse cortical neurons and an in vivo mouse model to study mechanisms of DNA damaged-induced apoptosis in immature and differentiated neurons. p53 drives apoptosis of immature and differentiated cortical neurons through its rapid and prominent activation stimulated by DNA strand breaks induced by topoisomerase-I and -II inhibition. Blocking p53-DNA transactivation with α-pifithrin protects immature neurons; blocking p53-mitochondrial functions with μ-pifithrin protects differentiated neurons. Mitochondrial death proteins are upregulated in apoptotic immature and differentiated neurons and have nonredundant proapoptotic functions; Bak is more dominant than Bax in differentiated neurons. p53 phosphorylation is mediated by ataxia telangiectasia mutated (ATM) kinase. ATM inactivation is antiapoptotic, particularly in differentiated neurons, whereas inhibition of c-Abl protects immature neurons but not differentiated neurons. Cell death protein expression patterns in mouse forebrain are mostly similar to cultured neurons. DNA damage induces prominent p53 activation and apoptosis in cerebral cortex in vivo. Thus, DNA strand breaks in cortical neurons induce rapid p53-mediated apoptosis through actions of upstream ATM and c-Abl kinases and downstream mitochondrial death proteins. This molecular network operates through variations depending on neuron maturity. PMID:18820287

  5. Glycyrrhizic acid pretreatment prevents sepsis-induced acute kidney injury via suppressing inflammation, apoptosis and oxidative stress.

    PubMed

    Zhao, Hongyu; Liu, Zhenning; Shen, Haitao; Jin, Shuai; Zhang, Shun

    2016-06-15

    Glycyrrhizic acid (GA), an active ingredient in licorice, has multiple pharmacological activities. The aim of our study was to investigate the molecular mechanism involved in the protective effects of GA in lipopolysaccharide (LPS) stimulated rat mesangial cells (HBZY-1) and septic rats. Sepsis model was established by injection of 5mg/kg LPS in rats or incubation with 1μg/ml LPS for 24h in HBZY-1 cells. A variety of molecular biological experiments were carried out to assess the effects of GA on inflammation, apoptosis, and oxidative stress. First we found that GA alleviated sepsis-induced kidney injury in vivo. Furthermore, GA suppressed inflammatory response in vivo and in vitro. Additionally, GA inhibited cell apoptosis and the changes in expressions of apoptosis related proteins induced by LPS. Moreover, GA markedly inhibited oxidative stress induced by LPS via activation of ERK signaling pathway. Finally GA could inhibit the activation of NF-κ B induced by LPS. Our present study indicates that GA has a protective effect against sepsis-induced inflammatory response, apoptosis, and oxidative stress damage, which provides a molecular basis for a new medical treatment of septic acute kidney injury. PMID:27063444

  6. Reduced ultraviolet-induced DNA damage and apoptosis in human skin with topical application of a photolyase-containing DNA repair enzyme cream: clues to skin cancer prevention.

    PubMed

    Berardesca, Enzo; Bertona, Marco; Altabas, Karmela; Altabas, Velimir; Emanuele, Enzo

    2012-02-01

    The exposure of human skin to ultraviolet radiation (UVR) results in the formation of DNA photolesions that give rise to photoaging, mutations, cell death and the onset of carcinogenic events. Photolyase (EC 4.1.99.3) is a DNA repair enzyme that reverses damage caused by exposure to UVR. We sought to investigate whether addition of photolyase enhances the protection provided by a traditional sunscreen (SS), by reducing the in vivo formation of cyclobutane-type pyrimidine dimers (CPDs) and UVR-induced apoptosis in human skin. Ten volunteers (Fitzpatrick skin type II) were exposed to solar-simulated (ss) UVR at a three times minimal erythema dose for 4 consecutive days. Thirty minutes prior to each exposure, the test materials [vehicle, SS (sun protection factor 50) alone, and SS plus photolyase from Anacystis nidulans] were applied topically to three different sites. One additional site was left untreated and one received ssUVR only. Biopsy specimens were taken 72 h after the last irradiation. The amount of CPDs and the extent of apoptosis were measured by ELISA. Photolyase plus SS was superior to SS alone in reducing both the formation of CPDs and apoptotic cell death (both P<0.001). In conclusion, the addition of photolyase to a traditional SS contributes significantly to the prevention of UVR-induced DNA damage and apoptosis when applied topically to human skin. PMID:22086236

  7. Dihydroartemisinin prevents liver fibrosis in bile duct ligated rats by inducing hepatic stellate cell apoptosis through modulating the PI3K/Akt pathway.

    PubMed

    Chen, Qin; Chen, Lianyun; Wu, Xiafei; Zhang, Feng; Jin, Huanhuan; Lu, Chunfeng; Shao, Jiangjuan; Kong, Desong; Wu, Li; Zheng, Shizhong

    2016-03-01

    As a frequent event following chronic insult, liver fibrosis triggers wound healing reactions, with extracellular matrix components accumulated in the liver. During liver fibrogenesis, activation of hepatic stellate cells (HSCs) is the pivotal event. Fibrosis regression can feasibly be treated through pharmacological induction of HSC apoptosis. Herein we showed that dihydroartemisinin (DHA) improved liver histological architecture, decreased hepatic enzyme levels, and inhibited HSCs activation in the fibrotic rat liver. DHA also induced apoptosis of HSCs in such liver, as demonstrated by reduced distribution of α-SMA-positive cells and the presence of high number of cleaved-caspase-3-positive cells in vivo, as well as by down-regulation of Bcl-2 and up-regulation of Bax. In addition, in vitro experiments showed that DHA significantly inhibited HSC proliferation and led to dramatic morphological alterations in HSCs. we found that DHA disrupted mitochondrial functions and led to activation of caspase cascades in HSCs. Mechanistic investigations revealed that DHA induced HSC apoptosis through disrupting the phosphoinositide 3-kinase (PI3K)/Akt pathway and that PI3K specific inhibitor LY294002 mimicked the pro-apoptotic effect of DHA. DHA is a promising candidate for the prevention and treatment of liver fibrosis. PMID:26865509

  8. Addition of Exogenous NAD+ Prevents Mefloquine-Induced Neuroaxonal and Hair Cell Degeneration through Reduction of Caspase-3-Mediated Apoptosis in Cochlear Organotypic Cultures

    PubMed Central

    Ding, Dalian; Qi, Weidong; Yu, Dongzhen; Jiang, Haiyan; Han, Chul; Kim, Mi-Jung; Katsuno, Kana; Hsieh, Yun Hua; Miyakawa, Takuya; Salvi, Richard; Tanokura, Masaru; Someya, Shinichi

    2013-01-01

    Background Mefloquine is widely used for the treatment of malaria. However, this drug is known to induce neurological side effects including depression, anxiety, balance disorder, and sensorineural hearing loss. Yet, there is currently no treatment for these side effects. Principal Findings In this study, we show that the coenzyme NAD+, known to play a critical role in maintaining the appropriate cellular redox environment, protects cochlear axons and sensory hair cells from mefloquine-induced degeneration in cultured rat cochleae. Mefloquine alone destroyed hair cells and nerve fiber axons in rat cochlear organotypics cultures in a dose-dependent manner, while treatment with NAD+ protected axons and hair cells from mefloquine-induced degeneration. Furthermore, cochlear organs treated with mefloquine showed increased oxidative stress marker levels, including superoxide and protein carbonyl, and increased apoptosis marker levels, including TUNEL-positive nuclei and caspases-3. Treatment with NAD+ reduced the levels of these oxidative stress and apoptosis markers. Conclusions/Significance Taken together, our findings suggest that that mefloquine disrupts the cellular redox environment and induces oxidative stress in cochlear hair cells and nerve fibers leading to caspases-3-mediated apoptosis of these structures. Exogenous NAD+ suppresses mefloquine-induced oxidative stress and prevents the degeneration of cochlear axons and sensory hair cells caused by mefloquine treatment. PMID:24223197

  9. Protection from palmitate-induced mitochondrial DNA damage prevents from mitochondrial oxidative stress, mitochondrial dysfunction, apoptosis, and impaired insulin signaling in rat L6 skeletal muscle cells.

    PubMed

    Yuzefovych, Larysa V; Solodushko, Viktoriya A; Wilson, Glenn L; Rachek, Lyudmila I

    2012-01-01

    Saturated free fatty acids have been implicated in the increase of oxidative stress, mitochondrial dysfunction, apoptosis, and insulin resistance seen in type 2 diabetes. The purpose of this study was to determine whether palmitate-induced mitochondrial DNA (mtDNA) damage contributed to increased oxidative stress, mitochondrial dysfunction, apoptosis, impaired insulin signaling, and reduced glucose uptake in skeletal muscle cells. Adenoviral vectors were used to deliver the DNA repair enzyme human 8-oxoguanine DNA glycosylase/(apurinic/apyrimidinic) lyase (hOGG1) to mitochondria in L6 myotubes. After palmitate exposure, we evaluated mtDNA damage, mitochondrial function, production of mitochondrial reactive oxygen species, apoptosis, insulin signaling pathways, and glucose uptake. Protection of mtDNA from palmitate-induced damage by overexpression of hOGG1 targeted to mitochondria significantly diminished palmitate-induced mitochondrial superoxide production, restored the decline in ATP levels, reduced activation of c-Jun N-terminal kinase (JNK) kinase, prevented cells from entering apoptosis, increased insulin-stimulated phosphorylation of serine-threonine kinase (Akt) (Ser473) and tyrosine phosphorylation of insulin receptor substrate-1, and thereby enhanced glucose transporter 4 translocation to plasma membrane, and restored insulin signaling. Addition of a specific inhibitor of JNK mimicked the effect of mitochondrial overexpression of hOGG1 and partially restored insulin sensitivity, thus confirming the involvement of mtDNA damage and subsequent increase of oxidative stress and JNK activation in insulin signaling in L6 myotubes. Our results are the first to report that mtDNA damage is the proximal cause in palmitate-induced mitochondrial dysfunction and impaired insulin signaling and provide strong evidence that targeting DNA repair enzymes into mitochondria in skeletal muscles could be a potential therapeutic treatment for insulin resistance. PMID:22128025

  10. Hypoxia-induced p53 modulates both apoptosis and radiosensitivity via AKT

    PubMed Central

    Leszczynska, Katarzyna B.; Foskolou, Iosifina P.; Abraham, Aswin G.; Anbalagan, Selvakumar; Tellier, Céline; Haider, Syed; Span, Paul N.; O’Neill, Eric E.; Buffa, Francesca M.; Hammond, Ester M.

    2015-01-01

    Restoration of hypoxia-induced apoptosis in tumors harboring p53 mutations has been proposed as a potential therapeutic strategy; however, the transcriptional targets that mediate hypoxia-induced p53-dependent apoptosis remain elusive. Here, we demonstrated that hypoxia-induced p53-dependent apoptosis is reliant on the DNA-binding and transactivation domains of p53 but not on the acetylation sites K120 and K164, which, in contrast, are essential for DNA damage–induced, p53-dependent apoptosis. Evaluation of hypoxia-induced transcripts in multiple cell lines identified a group of genes that are hypoxia-inducible proapoptotic targets of p53, including inositol polyphosphate-5-phosphatase (INPP5D), pleckstrin domain–containing A3 (PHLDA3), sulfatase 2 (SULF2), B cell translocation gene 2 (BTG2), cytoplasmic FMR1-interacting protein 2 (CYFIP2), and KN motif and ankyrin repeat domains 3 (KANK3). These targets were also regulated by p53 in human cancers, including breast, brain, colorectal, kidney, bladder, and melanoma cancers. Downregulation of these hypoxia-inducible targets associated with poor prognosis, suggesting that hypoxia-induced apoptosis contributes to p53-mediated tumor suppression and treatment response. Induction of p53 targets, PHLDA3, and a specific INPP5D transcript mediated apoptosis in response to hypoxia through AKT inhibition. Moreover, pharmacological inhibition of AKT led to apoptosis in the hypoxic regions of p53-deficient tumors and consequently increased radiosensitivity. Together, these results identify mediators of hypoxia-induced p53-dependent apoptosis and suggest AKT inhibition may improve radiotherapy response in p53-deficient tumors. PMID:25961455

  11. Maternal antioxidants prevent beta cell apoptosis and promote formation of dual hormone-expressing endocrine cells in male offspring following fetal and neonatal nicotine exposure

    PubMed Central

    BRUIN, Jennifer E; WOYNILLOWICZ, Amanda K; HETTINGA, Bart P; TARNOPOLSKY, Mark A; MORRISON, Katherine M; GERSTEIN, Hertzel C; HOLLOWAY, Alison C

    2013-01-01

    Aim Fetal and neonatal nicotine exposure causes beta cell oxidative stress and apoptosis in neonates, leading to adult-onset dysglycemia. The goal of this study was to determine whether an antioxidant intervention could prevent nicotine-induced beta cell loss. Methods Nulliparous female Wistar rats received daily subcutaneous injections of either saline or nicotine bitartrate (1.0 mg/kg/d) for 2 weeks prior to mating until weaning. Nicotine-exposed dams received either normal chow or diet containing antioxidants (1000 IU/kg vitamin E, 0.25% w/w coenzyme Q10 and 0.1% w/w alpha-lipoic acid) during mating, pregnancy and lactation; saline-exposed dams received normal chow. Pancreas tissue was collected from male offspring at 3 weeks of age to measure beta cell fraction, apoptosis, proliferation and the presence of cells co-expressing insulin and glucagon. Results The birth weight of the offspring born to nicotine-exposed dams receiving dietary antioxidants was significantly reduced. Most interestingly, the antioxidant intervention to nicotine-exposed dams prevented the beta cell loss and apoptosis observed in nicotine exposed male offspring whose mothers did not receive antioxidants. Male pups born to nicotine-treated mothers receiving antioxidants also had a trend towards increased beta cell proliferation and a significant increase in islets containing insulin/glucagon bi-hormonal cells relative to the other two treatment groups. Conclusion This study demonstrates that exposure to maternal antioxidants protects beta cells from the damaging effects of nicotine thus preserving beta cell mass. PMID:22385833

  12. 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-β-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 α-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 α-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

  13. Fermented soybeans, Chungkookjang, prevent hippocampal cell death and β-cell apoptosis by decreasing pro-inflammatory cytokines in gerbils with transient artery occlusion.

    PubMed

    Park, Sunmin; Kim, Da Sol; Kang, Sunna; Moon, Bo Reum

    2016-02-01

    Since Chungkookjang, a short-term fermented soybean, is known to improve glucose metabolism and antioxidant activity, it may prevent the neurological symptoms and glucose disturbance induced by artery occlusion. We investigated the protective effects and mechanisms of traditional (TFC) and standardized Chungkookjang fermented with Bacillus licheniformis (BLFC) against ischemia/reperfusion damage in the hippocampal CA1 region and against hyperglycemia after transient cerebral ischemia in gerbils. Gerbils were subjected to either an occlusion of the bilateral common carotid arteries for 8 min to render them ischemic or a sham operation. Ischemic gerbils were fed either a 40% fat diet containing 10% of either cooked soybean (CSB), TFC, or BLFC for 28 days. Neuronal cell death and cytokine expression in the hippocampus, neurological deficit, serum cytokine levels, and glucose metabolism were measured. TFC and BLFC contained more isoflavonoid aglycones than CSB. Artery occlusion increased the expressions of IL-1β and TNF-α as well as cell death in the hippocampal CA1 region and induced severe neurological symptoms. CSB, TFC, and BLFC prevented the neuronal cell death and the symptoms such as dropped eyelid, bristling hair, reduced muscle tone and flexor reflex, and abnormal posture and walking patterns, and suppressed cytokine expressions. CSB was less effective than TFC and BLFC. Artery occlusion induced glucose intolerance due to decreased insulin secretion and β-cell mass. TFC and BLFC prevented the impairment of glucose metabolism by artery occlusion. Especially TFC and BLFC increased β-cell proliferation and suppressed the β-cell apoptosis by suppressing TNF-α and IL-1β which in turn decreased cleaved caspase-3 that caused apoptosis. In conclusion, TFC and BLFC may prevent and alleviate neuronal cell death in the hippocampal CA1 region and neurological symptoms and poststroke hyperglycemia in gerbils with artery occlusion. This might be associated with

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

    SciTech Connect

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

    2014-09-26

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

  15. MDM2-regulated degradation of HIPK2 prevents p53Ser46 phosphorylation and DNA damage-induced apoptosis.

    PubMed

    Rinaldo, Cinzia; Prodosmo, Andrea; Mancini, Francesca; Iacovelli, Stefano; Sacchi, Ada; Moretti, Fabiola; Soddu, Silvia

    2007-03-01

    In response to DNA damage, p53 induces either cell-cycle arrest or apoptosis by differential transcription of several target genes and through transcription-independent apoptotic functions. p53 phosphorylation at Ser46 by HIPK2 is one determinant of the outcome because it takes place only upon severe, nonrepairable DNA damage that irreversibly drives cells to apoptosis. Here, we show that p53 represses its proapoptotic activator HIPK2 via MDM2-mediated degradation, whereas a degradation-resistant HIPK2 mutant has increased apoptotic activity. Upon cytostatic, nonsevere DNA damage, inhibition of HIPK2 degradation is sufficient to induce p53Ser46 phosphorylation and apoptosis, converting growth-arresting stimuli to apoptotic ones. These findings establish HIPK2 as an MDM2 target and support a model in which, upon nonsevere DNA damage, p53 represses its own phosphorylation at Ser46 due to HIPK2 degradation, supporting the notion that the cell-cycle-arresting functions of p53 include active inhibition of the apoptotic ones. PMID:17349959

  16. Pyruvate kinase M2 prevents apoptosis via modulating Bim stability and associates with poor outcome in hepatocellular carcinoma

    PubMed Central

    Li, Min; Zhang, Chao; Liu, Li-Li; Fu, Jia; Jin, Jie-Tian; Luo, Rong-Zhen; Zhang, Chris Zhiyi; Yun, Jing-Ping

    2015-01-01

    Pyruvate kinase M2 (PKM2) contributes to the Warburg effect, a hallmark of cancer. We showed that PKM2 levels were correlated with overall survival (hazard ration = 1.675, 95% confidence interval: 1.389–2.019, P < 0.001) and disease-free survival (hazard ration = 1.573, 95% confidence interval: 1.214–2.038, P < 0.001) in a cohort of 490 patients with HCC. The correlations were further validated in an independent cohort of 148 HCC patients. Multivariate analyses revealed that PKM2 was an independent indicator of poor outcome in HCC. The knockdown of PKM2 in HCC cells inhibited cell proliferation and induced apoptosis in vitro and in vivo. Bim siRNA markedly abolished the PKM2-depletion-induced apoptosis. PKM2 depletion decreased the degradation of Bim. In clinical samples, PKM2 expression was reversely correlated with Bim expression. Combination of PKM2 and Bim levels had the best prognostic significance. We suggest that PKM2 serves as a promising biomarker for poor prognosis of patients with HCC and its knockdown induces HCC apoptosis by stabilizing Bim. PMID:25788265

  17. Disruption of Smad5 gene induces mitochondria-dependent apoptosis in cardiomyocytes

    SciTech Connect

    Sun Yanxun; Zhou Jiang; Liao Xudong; Lue Yaxin; Deng Chuxia; Huang Peitang; Chen Quan; Yang Xiao . E-mail: yangx@nic.bmi.ac.cn

    2005-05-15

    Our previous studies have shown that SMAD5, an important intracellular mediator of transforming growth factor {beta} (TGF-{beta}) family, is required for normal development of the cardiovascular system in vivo. In the current study, we reported that the lack of the Smad5 gene resulted in apoptosis of cardiac myocytes in vivo. To further investigate the mechanism of the Smad5 gene in cardiomyocyte apoptosis, the embryonic stem (ES) cell differentiation system was employed. We found that the myotubes that differentiated from the homozygous Smad5 {sup ex6/ex6} mutant ES cells underwent collapse and degeneration during the late stages of in vitro differentiation, mimicking the in vivo observation. By electron microscopy, abnormal swollen mitochondria were observed in cardiomyocytes both from Smad5-deficient embryos and from ES-differentiated cells. There was also a significant reduction in mitochondrial membrane potential ({delta}{psi} {sub m}) and a leakage of cytochrome c from mitochondria into the cytosol of myocytes differentiated from Smad5 mutant ES cells. The expression of p53 and p21 was found to be elevated in the differentiated Smad5 mutant myocytes, and this was accompanied by an up-regulation in caspase 3 expression. These results suggest that the Smad5-mediated TGF-{beta} signals may protect cardiomyocytes from apoptosis by maintaining the integrity of the mitochondria, probably through suppression of p53 mediated pathways.

  18. Host Immune Defense Peptide LL-37 Activates Caspase-Independent Apoptosis and Suppresses Colon Cancer

    PubMed Central

    Ren, Shun X.; Cheng, Alfred S.L.; To, Ka F.; Tong, Joanna H.M.; Li, May S.; Shen, Jin; Wong, Clover C.M.; Zhang, Lin; Chan, Ruby L.Y.; Wang, Xiao J.; Ng, Simon S.M.; Chiu, Lawrence C.M.; Marquez, Victor E.; Gallo, Richard L.; Chan, Francis K.L.; Yu, Jun; Sung, Joseph J.Y.; Wu, William K.K.; Cho, Chi H.

    2014-01-01

    Cathelicidins are a family of bacteriocidal polypeptides secreted by macrophages and polymorphonuclear leukocytes (PMN). LL-37, the only human cathelicidin, has been implicated in tumorigenesis, but there has been limited investigation of its expression and function in cancer. Here, we report that LL-37 activates a p53-mediated, caspase-independent apoptotic cascade that contributes to suppression of colon cancer. LL-37 was expressed strongly in normal colon mucosa but downregulated in colon cancer tissues, where in both settings its expression correlated with terminal deoxynucleotidyl transferase–mediated dUTP nick end labeling-positive apoptotic cells. Exposure of colon cancer cells to LL-37 induced phosphatidylserine externalization and DNA fragmentation in a manner independent of caspase activation. Apoptogenic function was mediated by nuclear translocation of the proapoptotic factors, apoptosis-inducing factor (AIF) and endonuclease G (EndoG), through p53-dependent upregulation of Bax and Bak and downregulation of Bcl-2 via a pertussis toxin–sensitive G-protein–coupled receptor (GPCR) pathway. Correspondingly, colonic mucosa of cathelicidin-deficient mice exhibited reduced expression of p53, Bax, and Bak and increased expression of Bcl-2 together with a lower basal level of apoptosis. Cathelicidin-deficient mice exhibited an increased susceptibility to azoxymethane-induced colon tumorigenesis, establishing pathophysiologic relevance in colon cancer. Collectively, our findings show that LL-37 activates a GPCR-p53-Bax/Bak/Bcl-2 signaling cascade that triggers AIF/EndoG–mediated apoptosis in colon cancer cells. PMID:23100468

  19. Selective cellular uptake and induction of apoptosis of cancer-targeted selenium nanoparticles.

    PubMed

    Huang, Yanyu; He, Lizhen; Liu, Wen; Fan, Cundong; Zheng, Wenjie; Wong, Yum-Shing; Chen, Tianfeng

    2013-09-01

    Selenium nanoparticles (SeNPs) have garnered a great deal of attention as potential cancer therapeutic payloads. However, the in vivo targeting drug delivery has been challenging. Herein, we describe the synthesis of tansferrin (Tf)-conjugated SeNPs and its use as a cancer-targeted drug delivery system to achieve enhanced cellular uptake and anticancer efficacy. Tf as targeting ligand significantly enhances the cellular uptake of doxorubicin (DOX)-loaded SeNPs through clathrin-mediated and caveolae/lipid raft-mediated endocytosis in cancer cells overexpressing transferrin receptor, and increases their selectivity between cancer and normal cells. DOX-loaded and Tf-conjugated SeNPs (Tf-SeNPs) exhibits unprecedented enhanced cytotoxicity toward cancer cells through induction of apoptosis with the involvement of intrinsic and extrinsic pathways. Internalized Tf-SeNPs triggers intracellular ROS overproduction, thus activates p53 and MAPKs pathways to promote cell apoptosis. In the nude mice xenograft experiment, Tf-SeNPs significantly inhibits the tumor growth via induction of p53-mediated apoptosis. This cancer-targeted design of SeNPs opens a new path for synergistic treating of cancer with higher efficacy and decreased side effects. PMID:23800743

  20. Soy phytochemicals prevent orthotopic growth and metastasis of bladder cancer in mice by alterations of cancer cell proliferation and apoptosis and tumor angiogenesis.

    PubMed

    Singh, Ajita V; Franke, Adrian A; Blackburn, George L; Zhou, Jin-Rong

    2006-02-01

    A role of dietary bioactive components in bladder cancer prevention is biologically plausible because most substances or metabolites are excreted through the urinary tract and are consequently in direct contact with the mucosa of the bladder. We first determined antigrowth activity of genistein against poorly differentiated 253J B-V human bladder cancer cells in vitro. Genistein inhibited the cell growth in a time- and dose-dependent manner via G(2)-M arrest, down-regulation of nuclear factor kappaB (NF-kappaB), and induction of apoptosis. We also evaluated both genistin, which is a natural form of genistein, and the isoflavone-rich soy phytochemical concentrate (SPC) on the growth and metastasis of 253J B-V tumors in an orthotopic tumor model. Mice treated with genistin and SPC had reduced final tumor weights by 56% (P < 0.05) and 52% (P < 0.05), respectively, associated with induction of tumor cell apoptosis and inhibition of tumor angiogenesis in vivo. In addition, SPC treatment, but not genistin treatment, significantly inhibited lung metastases by 95% (P < 0.01) associated with significant down-regulation of NF-kappaB expression in tumor tissues and reduction of circulating insulin-like growth factor-I levels, suggesting that SPC may contain other bioactive ingredients that have antimetastatic activity. The results from our studies suggest that further clinical investigation should be warranted to apply soy phytochemicals, such as SPC, as a potent prevention regimen for bladder cancer progression. This orthotopic human bladder tumor model also provides a clinically relevant experimental tool for assessing potential preventive activity of other dietary components against bladder tumor growth and metastasis. PMID:16452247

  1. Inhibition of Osteocyte Apoptosis Prevents the Increase in Osteocytic Receptor Activator of Nuclear Factor κB Ligand (RANKL) but Does Not Stop Bone Resorption or the Loss of Bone Induced by Unloading*

    PubMed Central

    Plotkin, Lilian I.; Gortazar, Arancha R.; Davis, Hannah M.; Condon, Keith W.; Gabilondo, Hugo; Maycas, Marta; Allen, Matthew R.; Bellido, Teresita

    2015-01-01

    Apoptosis of osteocytes and osteoblasts precedes bone resorption and bone loss with reduced mechanical stimulation, and receptor activator of NF-κB ligand (RANKL) expression is increased with unloading in mice. Because osteocytes are major RANKL producers, we hypothesized that apoptotic osteocytes signal to neighboring osteocytes to increase RANKL expression, which, in turn, increases osteoclastogenesis and bone resorption. The traditional bisphosphonate (BP) alendronate (Aln) or IG9402, a BP analog that does not inhibit resorption, prevented the increase in osteocyte apoptosis and osteocytic RANKL expression. The BPs also inhibited osteoblast apoptosis but did not prevent the increase in osteoblastic RANKL. Unloaded mice exhibited high serum levels of the bone resorption marker C-telopeptide fragments of type I collagen (CTX), elevated osteoclastogenesis, and increased osteoclasts in bone. Aln, but not IG9402, prevented all of these effects. In addition, Aln prevented the reduction in spinal and femoral bone mineral density, spinal bone volume/tissue volume, trabecular thickness, mechanical strength, and material strength induced by unloading. Although IG9402 did not prevent the loss of bone mass, it partially prevented the loss of strength, suggesting a contribution of osteocyte viability to strength independent of bone mass. These results demonstrate that osteocyte apoptosis leads to increased osteocytic RANKL. However, blockade of these events is not sufficient to restrain osteoclast formation, inhibit resorption, or stop bone loss induced by skeletal unloading. PMID:26085098

  2. Interleukin-10 prevents epithelial cell apoptosis by regulating IFNγ and TNFα expression in rhesus macaque colon explants

    PubMed Central

    Pan, Diganta; Das, Arpita; Lala, Wendy; Kenway-Lynch, Carys S.; Liu, David X.; Veazey, Ronald S.; Pahar, Bapi

    2013-01-01

    Interleukin-10 (IL-10) is an important immunomodulatory cytokine that plays an obligate role in regulating inflammatory responses. Here we demonstrated the role of IL-10 in regulating crypts length and breadth as well as maintaining the survival of epithelial cells using rhesus colon explant cultures. Anti-IL-10 antibody treatment of colon explant cultures induced increased production of inflammatory cytokines/molecules like IFNγ, TNFα, CD107a and perforin as well as increased epithelial cell apoptosis compared to media controls tested. Our results suggest that IL-10 plays a crucial role in maintaining mucosal homeostasis by regulating mucosal IFNγ and TNFα cytokine production. PMID:23867612

  3. Interleukin-10 prevents epithelial cell apoptosis by regulating IFNγ and TNFα expression in rhesus macaque colon explants.

    PubMed

    Pan, Diganta; Das, Arpita; Lala, Wendy; Kenway-Lynch, Carys S; Liu, David X; Veazey, Ronald S; Pahar, Bapi

    2013-10-01

    Interleukin-10 (IL-10) is an important immunomodulatory cytokine that plays an obligate role in regulating inflammatory responses. Here we demonstrated the role of IL-10 in regulating crypts length and breadth as well as maintaining the survival of epithelial cells using rhesus colon explant cultures. Anti-IL-10 antibody treatment of colon explant cultures induced increased production of inflammatory cytokines/molecules like IFNγ, TNFα, CD107a and perforin as well as increased epithelial cell apoptosis compared to media controls tested. Our results suggest that IL-10 plays a crucial role in maintaining mucosal homeostasis by regulating mucosal IFNγ and TNFα cytokine production. PMID:23867612

  4. Cardiac progenitor cell-derived exosomes prevent cardiomyocytes apoptosis through exosomal miR-21 by targeting PDCD4.

    PubMed

    Xiao, J; Pan, Y; Li, X H; Yang, X Y; Feng, Y L; Tan, H H; Jiang, L; Feng, J; Yu, X Y

    2016-01-01

    Cardiac progenitor cells derived from adult heart have emerged as one of the most promising stem cell types for cardiac protection and repair. Exosomes are known to mediate cell-cell communication by transporting cell-derived proteins and nucleic acids, including various microRNAs (miRNAs). Here we investigated the cardiac progenitor cell (CPC)-derived exosomal miRNAs on protecting myocardium under oxidative stress. Sca1(+)CPCs-derived exosomes were purified from conditional medium, and identified by nanoparticle trafficking analysis (NTA), transmission electron microscopy and western blotting using CD63, CD9 and Alix as markers. Exosomes production was measured by NTA, the result showed that oxidative stress-induced CPCs secrete more exosomes compared with normal condition. Although six apoptosis-related miRNAs could be detected in two different treatment-derived exosomes, only miR-21 was significantly upregulated in oxidative stress-induced exosomes compared with normal exosomes. The same oxidative stress could cause low miR-21 and high cleaved caspase-3 expression in H9C2 cardiac cells. But the cleaved caspase-3 was significantly decreased when miR-21 was overexpressed by transfecting miR-21 mimic. Furthermore, miR-21 mimic or inhibitor transfection and luciferase activity assay confirmed that programmed cell death 4 (PDCD4) was a target gene of miR-21, and miR-21/PDCD4 axis has an important role in anti-apoptotic effect of H9C2 cell. Western blotting and Annexin V/PI results demonstrated that exosomes pre-treated H9C2 exhibited increased miR-21 whereas decreased PDCD4, and had more resistant potential to the apoptosis induced by the oxidative stress, compared with non-treated cells. These findings revealed that CPC-derived exosomal miR-21 had an inhibiting role in the apoptosis pathway through downregulating PDCD4. Restored miR-21/PDCD4 pathway using CPC-derived exosomes could protect myocardial cells against oxidative stress-related apoptosis. Therefore

  5. Hyperbaric oxygen treatment prevents nitric oxide-induced apoptosis in articular cartilage injury via enhancement of the expression of heat shock protein 70.

    PubMed

    Ueng, Steve W N; Yuan, Li-Jen; Lin, Song-Shu; Niu, Chi-Chien; Chan, Yi-Sheng; Wang, I-Chun; Yang, Chuen-Yung; Chen, Wen-Jer

    2013-03-01

    Heat shock proteins (HSPs), inflammatory cytokines, nitric oxide (NO), and localized hypoxia-induced apoptosis are thought to be correlated to the degree of cartilage injury. We investigated the effect of hyperbaric oxygen (HBO) on (1) interleukin-1β (IL-1β)-induced NO production and apoptosis of rabbit chondrocytes and (2) healing of articular cartilage defects. For the in vitro study, RT-PCR and Western blotting were performed to detect mRNA and protein expressions of HSP70, inducible NO synthase (iNOS), and caspase 3 in IL-1β-treated chondrocytes. To clarify that the HSP70 was necessary for anti-iNOS and anti-apoptotic activity by HBO, we treated the cells with an HSP70 inhibitor, KNK437. For the in vivo study, cartilage defects were created in rabbits. The HBO group was exposed to 100% oxygen at 2.5 ATA for 1.5 h a day for 10 weeks. The control group was exposed to normal air. After sacrifice, specimen sections were sent for examination using a scoring system. Immunohistochemical analyses were performed to detect the expressions of iNOS, HSP70, and caspase 3. Our results suggested that HBO upregulated the mRNA and protein expressions of HSP70 and suppressed those of iNOS and caspase 3 in chondrocytes. KNK437 inhibited the HBO-induced downregulation of iNOS and casapase 3 activities. The histological scores showed that HBO markedly enhanced cartilage repair. Immunohistostaining showed that HBO enhanced HSP70 expression and suppressed iNOS and caspase 3 expressions in chondrocytes. Accordingly, HBO treatment prevents NO-induced apoptosis in articular cartilage injury via enhancement of the expression of heat shock protein 70. PMID:22991091

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

    USGS Publications Warehouse

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

    2012-01-01

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

  7. Unconventional apoptosis of polymorphonuclear neutrophils (PMN): staurosporine delays exposure of phosphatidylserine and prevents phagocytosis by MΦ-2 macrophages of PMN.

    PubMed

    Franz, S; Muñoz, L E; Heyder, P; Herrmann, M; Schiller, M

    2015-01-01

    Apoptosis of polymorphonuclear neutrophils (PMN) and subsequent 'silent' removal represents an important check-point for the resolution of inflammation. Failure in PMN clearance resulting in secondary necrosis-driven tissue damage has been implicated in conditions of chronic inflammation and autoimmunity. Apoptotic PMN undergo profound biophysical changes that warrant their efficient recognition and uptake by phagocytes before fading to secondary necrosis. In this study, we demonstrate that staurosporine (STS), a non-selective but potent inhibitor of cyclin-dependent kinase and protein kinase C, exerts a drastic impact on PMN apoptosis. PMN treated with STS underwent an unconventional form of cell death characterized by a delayed exposure of aminophospholipids, including phosphatidylserine (PS) and phosphatidylethanolamine and an increased exposure of neo-glycans. STS caused an impaired cellular fragmentation and accelerated DNA fragmentation. Phagocytosis of STS-treated PMN lacking PS on their surfaces was decreased significantly, which highlights the importance of PS for the clearance of apoptotic PMN. Specific opsonization with immune complexes completely restored phagocytosis of STS-treated PMN, demonstrating the efficiency of back-up clearance pathways in the absence of PS exposure. PMID:24995908

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

    SciTech Connect

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

    2014-10-15

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

  9. Unconventional apoptosis of polymorphonuclear neutrophils (PMN): staurosporine delays exposure of phosphatidylserine and prevents phagocytosis by MΦ-2 macrophages of PMN

    PubMed Central

    Franz, S; Muñoz, L E; Heyder, P; Herrmann, M; Schiller, M

    2015-01-01

    Apoptosis of polymorphonuclear neutrophils (PMN) and subsequent ‘silent’ removal represents an important check-point for the resolution of inflammation. Failure in PMN clearance resulting in secondary necrosis-driven tissue damage has been implicated in conditions of chronic inflammation and autoimmunity. Apoptotic PMN undergo profound biophysical changes that warrant their efficient recognition and uptake by phagocytes before fading to secondary necrosis. In this study, we demonstrate that staurosporine (STS), a non-selective but potent inhibitor of cyclin-dependent kinase and protein kinase C, exerts a drastic impact on PMN apoptosis. PMN treated with STS underwent an unconventional form of cell death characterized by a delayed exposure of aminophospholipids, including phosphatidylserine (PS) and phosphatidylethanolamine and an increased exposure of neo-glycans. STS caused an impaired cellular fragmentation and accelerated DNA fragmentation. Phagocytosis of STS-treated PMN lacking PS on their surfaces was decreased significantly, which highlights the importance of PS for the clearance of apoptotic PMN. Specific opsonization with immune complexes completely restored phagocytosis of STS-treated PMN, demonstrating the efficiency of back-up clearance pathways in the absence of PS exposure. PMID:24995908

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

    PubMed

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

    2015-12-01

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

  11. Prevention of Anti-microbial Peptide LL-37-Induced Apoptosis and ATP Release in the Urinary Bladder by a Modified Glycosaminoglycan

    PubMed Central

    Lee, Won Yong; Savage, Justin R.; Zhang, Jianxing; Jia, Wanjian; Oottamasathien, Siam; Prestwich, Glenn D.

    2013-01-01

    Interstitial cystitis (IC), often referred to in combination with painful bladder syndrome, is a chronic inflammatory disease of the bladder. Current therapies primarily focus on replenishing urothelial glycosaminoglycan (GAG) layer using GAG analogs and managing pain with supportive therapies. However, the elusive etiology of IC and the lack of animal models to study the disease have been major hurdles developing more effective therapeutics. Previously, we showed an increased urinary concentration of antimicrobial peptide LL-37 in spina bifida patients and used LL-37 to develop a mouse model of cystitis that mimics important clinical findings of IC. Here we investigate (1) the molecular mechanism of LL-37 induced cystitis in cultured human urothelial cells and in mice, (2) the protective effects of GM-0111, a modified GAG, within the context of this mechanism, (3) the physiological and molecular markers that correlate with the severity of the inflammation, and (4) the protective effects of several GAGs using these biomarkers in our LL-37 induced cystitis model. We find that LL-37 quickly induces release of ATP and apoptosis in the urothelium. These changes can be inhibited by a chemically-modified GAG, GM-0111. Furthermore, we also find that GAG analogs provide varying degrees of protection against LL-37 challenge in mice. These findings suggest that GM-0111 and possibly GAG molecules prevent the development of cystitis by blocking the apoptosis and the concurrent release of ATP from the urothelium. PMID:24204996

  12. Cocoa-rich diet prevents azoxymethane-induced colonic preneoplastic lesions in rats by restraining oxidative stress and cell proliferation and inducing apoptosis.

    PubMed

    Rodríguez-Ramiro, Ildefonso; Ramos, Sonia; López-Oliva, Elvira; Agis-Torres, Angel; Gómez-Juaristi, Miren; Mateos, Raquel; Bravo, Laura; Goya, Luis; Martín, María Ángeles

    2011-12-01

    Cocoa is a rich source of bioactive compounds with potential chemopreventive ability but up to date its effectiveness in animal models of colon carcinogenesis has not been addressed. Herein, we investigated the in vivo effect of a cocoa-rich diet in the prevention of azoxymethane (AOM)-induced colon cancer and the mechanisms involved. Our results showed that cocoa feeding significantly reduced AOM-induced colonic aberrant crypt foci formation and crypt multiplicity. Oxidative imbalance in colon tissues seems to be prevented by cocoa as indicated by reduced oxidation markers levels and increased enzymatic and non-enzymatic endogenous defences. Cocoa-rich diet also exhibited antiproliferative effects by decreasing the levels of extracellular regulated kinases, protein kinase B and cyclin D1 together with pro-apoptotic effects evidenced by reduced Bcl-x(L) levels and increased Bax levels and caspase-3 activity. Our findings provide the first in vivo evidence that a cocoa-rich diet may inhibit the early stage of colon carcinogenesis probably by preventing oxidative stress and cell proliferation and by inducing apoptosis. PMID:21953728

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

    PubMed

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

    2010-03-01

    The present study was designed to investigate the protective efficacy of eugenol against skin cancer and probe into the mechanistic aspects. Skin tumors were initiated by applying 160 nmol DMBA and promoted by twice weekly applications of 8.5 nmol TPA for 28 wk. All mice developed tumors by 13 wk of promotion. However, in mice pretreated with 30 microL eugenol, no tumors were detected until 8 wk (following anti-initiation protocol) and until 14 wk (following antipromotion protocol) of tumor promotion. PCNA and TUNEL immunohistochemistry of tumors revealed eugenol to ameliorate cell proliferation and elevate apoptosis respectively. The effect of eugenol was assessed on specific stages of carcinogenesis. Initiation with DMBA led to a significant upregulation of p53 expression with a concomitant increase in p21(WAF1) levels in epidermal cells indicating induction of damage to the DNA. However, pretreatment with eugenol led to overexpression of these genes, which probably helped stimulate apoptosis of the initiated cells. To ascertain the molecular mechanisms implicated in the antitumor promoting activity of eugenol, its effect was investigated on markers of tumor promotion and inflammation: ODC activity and iNOS and COX-2 expression, and on levels of proinflammatory cytokines (IL-6, TNF-alpha, and PGE(2)). Eugenol markedly inhibited all. Eugenol also inhibited the upstream signaling molecule: NF-kappaB, which regulates the expression of these genes. TPA-induced depletion of cutaneous GSH and antioxidant enzymes armory was also precluded by eugenol. From these results, it could be concluded that eugenol markedly protects against chemically induced skin cancer and acts possibly by virtue of its antiproliferative, anti-inflammatory, and antioxidant activities. PMID:20043298

  14. Polyphenols of Cassia tora leaves prevents lenticular apoptosis and modulates cataract pathology in Sprague-Dawley rat pups.

    PubMed

    Sreelakshmi, V; Abraham, Annie

    2016-07-01

    Cataract is a leading cause of visual impairment worldwide with multifactorial etiology and is a significant global health problem with increasing prevalence with age. Currently, no pharmacological measures are discovered to prevent and treat cataract and a significant number of epidemiological studies have suggested the potential role of antioxidants in the prevention of cataract by scavenging free radicals and preventing lens protein derangement and lenticular cell damage. The main goal of the present study is to evaluate Cassia tora leaves; an edible leafy vegetable employed in Ayurvedic and Chinese system of medicine for eye rejuvenation in preventing selenite-induced cataract in rat pups and to identify the active components that produce the effect. ECT pre-treatment effectively restored both enzymatic and metabolic antioxidant levels, membrane integrity and reduced metal accumulation and thus down-regulate epithelial cell death. Gene expression studies also confirmed these findings. ESI-MS analysis of ECT revealed the presence of chrysophanol, emodin, kaemferol, quercetin, stigmasterol and isoquercetin. The study suggests the possible role of C. tora in alleviating cataract pathology and presence of many anthraquinones and flavonoids. As it is an edible plant, the incorporation of these leaves in daily vegetables might prevent or delay the onset and maturation of cataract. PMID:27261615

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

  17. Acetylation of the p53 DNA binding domain regulates apoptosis induction.

    PubMed Central

    Sykes, Stephen M.; Mellert, Hestia S.; Holbert, Marc A.; Li, Keqin; Marmorstein, Ronen; Lane, William S.; McMahon, Steven B.

    2007-01-01

    SUMMARY The ability of p53 to induce apoptosis plays an important role in tumor suppression. Here we describe a previously unknown post-translational modification of the DNA-binding domain of p53. This modification, acetylation of lysine 120, occurs rapidly after DNA damage and is catalyzed by the MYST family acetyltransferases hMOF and TIP60. Mutation of lysine 120 to arginine, as occurs in human cancer, debilitates K120 acetylation and diminishes p53-mediated apoptosis without affecting cell-cycle arrest. The K120R mutation selectively blocks the transcription of pro-apoptotic target genes such as BAX and PUMA while the non-apoptotic targets p21 and hMDM2 remain unaffected. Consistent with this, depletion of hMOF and/or TIP60 inhibits the ability of p53 to activate BAX and PUMA transcription. Furthermore, the acetyl-lysine 120 form of p53 specifically accumulates at pro-apoptotic target genes. These data suggest that K120 acetylation may help distinguish the cell cycle arrest and apoptotic functions of p53. PMID:17189187

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

    PubMed Central

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

    2013-01-01

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

  19. Prevention

    MedlinePlus

    ... our e-newsletter! Aging & Health A to Z Prevention Basic Facts & Information Some factors that affect your ... control of the things that you can change. Preventive Recommendations for Adults Aged 65 and Older The ...

  20. GH-Releasing Hormone Promotes Survival and Prevents TNF-α-Induced Apoptosis and Atrophy in C2C12 Myotubes.

    PubMed

    Gallo, Davide; Gesmundo, Iacopo; Trovato, Letizia; Pera, Giulia; Gargantini, Eleonora; Minetto, Marco Alessandro; Ghigo, Ezio; Granata, Riccarda

    2015-09-01

    Skeletal muscle atrophy is a consequence of different chronic diseases, including cancer, heart failure, and diabetes, and also occurs in aging and genetic myopathies. It results from an imbalance between anabolic and catabolic processes, and inflammatory cytokines, such as TNF-α, have been found elevated in muscle atrophy and implicated in its pathogenesis. GHRH, in addition to stimulating GH secretion from the pituitary, exerts survival and antiapoptotic effects in different cell types. Moreover, we and others have recently shown that GHRH displays antiapoptotic effects in isolated cardiac myocytes and protects the isolated heart from ischemia/reperfusion injury and myocardial infarction in vivo. On these bases, we investigated the effects of GHRH on survival and apoptosis of TNF-α-treated C2C12 myotubes along with the underlying mechanisms. GHRH increased myotube survival and prevented TNF-α-induced apoptosis through GHRH receptor-mediated mechanisms. These effects involved activation of phosphoinositide 3-kinase/Akt pathway and inactivation of glycogen synthase kinase-3β, whereas mammalian target of rapamycin was unaffected. GHRH also increased the expression of myosin heavy chain and the myogenic transcription factor myogenin, which were both reduced by the cytokine. Furthermore, GHRH inhibited TNF-α-induced expression of nuclear factor-κB, calpain, and muscle ring finger1, which are all involved in muscle protein degradation. In summary, these results indicate that GHRH exerts survival and antiapoptotic effects in skeletal muscle cells through the activation of anabolic pathways and the inhibition of proteolytic routes. Overall, our findings suggest a novel therapeutic role for GHRH in the treatment of muscle atrophy-associated diseases. PMID:26110916

  1. Phosphorylation of Tip60 by GSK-3 determines the induction of PUMA and apoptosis by p53

    PubMed Central

    Charvet, Céline; Wissler, Manuela; Brauns-Schubert, Prisca; Wang, Shang-Jui; Tang, Yi; Sigloch, Florian C.; Mellert, Hestia; Brandenburg, Martin; Lindner, Silke E.; Breit, Bernhard; Green, Douglas R.; McMahon, Steven B.; Borner, Christoph; Gu, Wei; Maurer, Ulrich

    2011-01-01

    Summary Activation of p53 by DNA damage results in either cell cycle arrest, allowing DNA repair and cell survival, or induction of apoptosis. As these opposite outcomes are both mediated by p53 stabilization, additional mechanisms to determine this decision must exist. Here we show that glycogen synthase kinase-3 (GSK-3) is required for the p53-mediated induction of the pro-apoptotic BH3 only-protein PUMA, an essential mediator of p53-induced apoptosis. Inhibition of GSK-3 protected from cell death induced by DNA damage and promoted increased long-term cell survival. We demonstrate that GSK-3 phosphorylates serine 86 of the p53-acetyltransferase Tip60. A Tip60S86A mutant was less active to induce p53 K120 acetylation, Histone 4 acetylation and expression of PUMA. Our data suggest that GSK-3 mediated Tip60S86-phosphorylation provides a link between PI3K signaling and the choice for or against apoptosis induction by p53. PMID:21658600

  2. ACTIVITY-DEPENDENT NEUROPROTECTIVE PROTEIN–DERIVED PEPTIDE, NAP, PREVENTING ALCOHOL-INDUCED APOPTOSIS IN FETAL BRAIN OF C57BL/6 MOUSE

    PubMed Central

    SARI, Y.

    2012-01-01

    Possible prevention of the effects of prenatal alcohol exposure has been investigated using peptides that were previously shown to be involved in neuroprotection both in vitro and in vivo. I focused in this study on investigating the neuro-protective effects of one of these peptides with regard to the determination of the downstream signaling pathways involved in neuroprotection. This peptide with the sequence NAPVSIPQ, known as NAP, a fragment of activity-dependent neuroprotective protein, demonstrated a potent protective effect against oxidative stress associated with alcohol exposure. On embryonic day 7 (E7), weight-matched C57BL/6 pregnant females were assigned the following groups: (1) Ethanol liquid diet group (ALC) 25% (4.49%, v/v) ethano-derived calories, (2) Pair-fed (PF) control group (3) Chow control group, (4) treatment groups with alcohol alongside i.p. injections of d-NAP (ALC/d-NAP, 20 or 30 μg/20 g body weight), (5) PF/d-NAP control group. On E13, fetal brains were collected and assayed for TdT-mediated dUTP nick end labeling (TUNEL) staining, caspase-3 colorimetric assay and ELISA for cytochrome c detection. My results show that NAP significantly prevented alcohol-induced weight reduction of the fetal brain. Apoptosis was determined by TUNEL staining; NAP administration significantly prevented alcohol-induced increases in TUNEL-positive cells in primordium cingulate cortex and basal ganglia eminence. The investigation of downstream signaling pathways involving NAP neuroprotection revealed that this peptide significantly prevented alcohol-induced increase in the concentrations of caspase-3 in E13 fetal brains. Moreover, ELISA for cytochrome c shows that NAP significantly prevented both alcohol-induced increases in the level of cytosolic cytochrome c and alcohol-induced decreases in the level of mitochondrial cytochrome c. These data provide an understanding of NAP intracellular target, and the downstream mechanisms of action that will pave a path

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2004-12-01

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

  5. p53-dependent apoptosis contributes to di-(2-ethylhexyl) phthalate-induced hepatotoxicity.

    PubMed

    Ha, Mei; Wei, Li; Guan, Xie; Li, Lianbing; Liu, Changjiang

    2016-01-01

    Di-(2-ethylhexyl) phthalate (DEHP) is used extensively in many personal care and consumer products, resulting in widespread non-occupational human exposure through multiple routes and media. DEHP has various deleterious effects including hepatotoxicity. p53 protein is a central sensor in cell apoptosis. In order to clarify the roles of p53 in DEHP-induced hepatotoxicity, Sprague-Dawley (SD) rats were dosed daily with DEHP by gavage for 30 days; BRL cells (rat liver cell line) were treated with DEHP for 24 h after pretreatment with NAC or small interfering RNA (siRNA). Results indicated that after exposure to DEHP, hepatic histological changes such as hepatocyte edema, vacuolation and hepatic sinusoidal dilation, and increased apoptosis index were observed. In the liver, DEHP induced oxidative stress and DNA damage, which activated p53 in vivo and in vitro. Pretreatment with NAC significantly reduced ROS level and p53 expression in BRL cells. The suppressed Mdm2 also contributed to p53 accumulation. Activated p53 mediated hepatocyte apoptosis via the intrinsic mitochondrial pathway, inhibiting anti-apoptotic Bcl-2 and Bcl-xL and inducing pro-apoptotic Bax, cytochrome c and caspases. In p53-silenced BRL cells, hepatocyte apoptosis mediated by p53 was attenuated. PCNA protein level was upregulated after p53 gene silencing. However, the Fas/FasL apoptotic pathway did not exhibit activated signs in DEHP-caused hepatotoxicity. Taken together, DEHP-caused oxidative stress and Mdm2 downregulation contribute to p53 activation. The p53-dependent apoptotic pathway plays critical and indispensable roles in DEHP-induced hepatotoxicity, while the Fas/FasL pathway does not involve in this molecular event. PMID:26549752

  6. Prevention

    MedlinePlus

    ... Prevention Treatment 2003 U.S. Outbreak African Rodent Importation Ban For Clinicians Clinical Recognition Specimen Collection Treatment Smallpox ... Examining Animals with Suspected Monkeypox African Rodent Importation Ban Resources Related Links Poxvirus Molluscum Contagiosum Orf Virus ( ...

  7. Wild-type p53-mediated down-modulation of interleukin 15 and interleukin 15 receptors in human rhabdomyosarcoma cells.

    PubMed Central

    De Giovanni, C.; Nanni, P.; Sacchi, A.; Soddu, S.; Manni, I.; D'Orazi, G.; Bulfone-Paus, S.; Pohl, T.; Landuzzi, L.; Nicoletti, G.; Frabetti, F.; Rossi, I.; Lollini, P. L.

    1998-01-01

    We recently reported that rhabdomyosarcoma cell lines express and secrete interleukin 15 (IL-15), a tightly regulated cytokine with IL-2-like activity. To test whether the p53-impaired function that is frequently found in this tumour type could play a role in the IL-15 production, wild-type p53 gene was transduced in the human rhabdomyosarcoma cell line RD (which harbours a mutated p53 gene), and its effect on proliferation and expression of IL-15 was studied. Arrest of proliferation was induced by wild-type p53; increased proportions of G1-arrested cells and of apoptotic cells were observed. A marked down-modulation of IL-15 expression, at both the mRNA and protein level, was found in p53-transduced cells. Because a direct effect of IL-15 on normal muscle cells has been reported, the presence of IL-15 membrane receptors was studied by cytofluorometric analysis. Rhabdomyosarcoma cells showed IL-15 membrane receptors, which are down-modulated by wild-type p53 transfected gene. In conclusion, wild-type p53 transduction in human rhabdomyosarcoma cells induces the down-modulation of both IL-15 production and IL-15 receptor expression. Images Figure 3 PMID:9862562

  8. Novel small molecule induces p53-dependent apoptosis in human colon cancer cells

    SciTech Connect

    Park, Sang Eun; Min, Yong Ki; Ha, Jae Du; Kim, Bum Tae; Lee, Woo Ghil . E-mail: bigguy@krict.re.kr

    2007-07-06

    Using high-throughput screening with small-molecule libraries, we identified a compound, KCG165 [(2-(3-(2-(pyrrolidin-1-yl)ethoxy)-1,10b-dihydro-[1,2,4]triazolo[1,5-c] quinazolin-5(6H)-one)], which strongly activated p53-mediated transcriptional activity. KCG165-induced phosphorylations of p53 at Ser{sup 6}, Ser{sup 15}, and Ser{sup 20}, which are all key residues involved in the activation and stabilization of p53. Consistent with these findings, KCG165 increased level of p53 protein and led to the accumulation of transcriptionally active p53 in the nucleus with the increased occupancy of p53 in the endogenous promoter region of its downstream target gene, p21{sup WAF1/CIP}. Notably, KCG165-induced p53-dependent apoptosis in cancer cells. Furthermore, we suggested topoisomerase II as the molecular target of KCG165. Together, these results indicate that KCG165 may have potential applications as an antitumor agent.

  9. Damnacanthal is a potent inducer of apoptosis with anticancer activity by stimulating p53 and p21 genes in MCF-7 breast cancer cells.

    PubMed

    Aziz, Muhammad Yusran Abdul; Omar, Abdul Rahman; Subramani, Tamilselvan; Yeap, Swee Keong; Ho, Wan Yong; Ismail, Nor Hadiani; Ahmad, Syahida; Alitheen, Noorjahan Banu

    2014-05-01

    Damnacanthal, an anthraquinone compound, is isolated from the roots of Morinda citrifolia L. (noni), which has been used for traditional therapy in several chronic diseases, including cancer. Although noni has long been consumed in Asian and Polynesian countries, the molecular mechanisms by which it exerts several benefits are starting to emerge. In the present study, the effect of damnacanthal on MCF-7 cell growth regulation was investigated. Treatment of MCF-7 cells with damnacanthal for 72 h indicated an antiproliferative activity. The MTT method confirmed that damnacanthal inhibited the growth of MCF-7 cells at the concentration of 8.2 μg/ml for 72 h. In addition, the drug was found to induce cell cycle arrest at the G1 checkpoint in MCF-7 cells by cell cycle analysis. Damnacanthal induced apoptosis, determined by Annexin V-fluorescein isothiocyanate/propidium iodide (PI) dual-labeling, acridine-orange/PI dyeing and caspase-7 expression. Furthermore, damnacanthal-mediated apoptosis involves the sustained activation of p21, leading to the transcription of p53 and the Bax gene. Overall, the present study provided significant evidence demonstrating that p53-mediated damnacanthal induced apoptosis through the activation of p21 and caspase-7. PMID:24765160

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

    PubMed

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

    2014-01-01

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

  11. Induction of apoptosis in colon cancer cells by a novel topoisomerase I inhibitor TopIn

    SciTech Connect

    Bae, Soo Kyung; Gwak, Jungsug; Song, Im-Sook; Park, Hyung-Soon; Oh, Sangtaek

    2011-05-27

    Highlights: {yields} TopIn activates p53-dependent transcription in colon cancer cells. {yields} TopIn induces apoptosis in colon cancer cells. {yields} TopIn selectively inhibits topoisomerase I activity. {yields} TopIn does not affect the activity of BCRP and MDR-1. -- Abstract: The tumor suppressor p53 plays an important role in cellular emergency mechanisms through regulating the genes involved in cell cycle arrest and apoptosis. To identify small molecules that can activate p53-responsive transcription, we performed chemical screening using genetically engineered HCT116 reporter cells. We found that TopIn (7-phenyl-6H-[1,2,5]oxadiazolo[3,4-e]indole 3-oxide) efficiently activated p53-mediated transcriptional activity and induced phosphorylation of p53 at Ser15, thereby stabilizing the p53 protein. Furthermore, TopIn upregulated the expression of p21{sup WAF1/CIP1}, a downstream target of p53, and suppressed cellular proliferation in various colon cancer cells. Additionally, TopIn induced DNA fragmentation, caspase-3/7 activation and poly ADP ribose polymerase cleavage, typical biochemical markers of apoptosis, in p53 wild-type and mutated colon cancer cells. Finally, we found that TopIn inhibited topoisomerase I activity, but not topoisomerase II, in vitro and induced the formation of the topoisomerase I-DNA complex in HCT116 colon cancer cells. Unlike camptothecin (CPT) and its derivative SN38, TopIn did not affect the activity of the ATP-binding cassette transporter breast cancer resistance protein (BCRP) or multidrug-resistant protein-1 (MDR-1). These results suggest that TopIn may present a promising new topoisomerase I-targeting anti-tumor therapeutics.

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

    PubMed Central

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

    2016-01-01

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

  13. Silencing of the Baculovirus Op-iap3 Gene by RNA Interference Reveals that It Is Required for Prevention of Apoptosis during Orgyia pseudotsugata M Nucleopolyhedrovirus Infection of Ld652Y Cells†

    PubMed Central

    Means, John C.; Muro, Israel; Clem, Rollie J.

    2003-01-01

    The Op-iap3 gene from the baculovirus Orgyia pseudotsugata M nucleopolyhedrovirus (OpMNPV) inhibits apoptosis induced by a mutant of Autographa californica MNPV (AcMNPV) that lacks the antiapoptotic gene p35, as well as apoptosis induced by a wide range of other stimuli in both mammalian and insect cells. However, the role of Op-iap3 during OpMNPV infection has not been previously examined. To determine the function of the Op-IAP3 protein during OpMNPV infection, we used RNA interference (RNAi) to silence Op-iap3 expression during OpMNPV infection of Ld652Y cells. Infected cells treated with Op-iap3 double-stranded RNA (dsRNA) did not accumulate detectable Op-iap3 mRNA, confirming that the Op-iap3 gene was effectively silenced. Op-IAP3 protein was found to be a component of the budded virion; however, in OpMNPV-infected cells treated with Op-iap3 dsRNA, the Op-IAP3 protein that was introduced by the inoculum virus decreased to almost undetectable levels by 12 h after dsRNA addition. Apoptosis was observed in infected cells treated with Op-iap3 dsRNA beginning at 12 h, and by 48 h, almost all of the cells had undergone apoptosis. These results show for the first time that Op-IAP3 is necessary to prevent apoptosis during OpMNPV infection. In addition, our results demonstrate that the RNAi technique can be an effective tool for studying baculovirus gene function. PMID:12663755

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

    SciTech Connect

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

    2005-05-13

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

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

    PubMed

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

    2016-01-01

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

  16. P53 is required for Doxorubicin-induced apoptosis via the TGF-beta signaling pathway in osteosarcoma-derived cells.

    PubMed

    Sun, Yifu; Xia, Peng; Zhang, Haipeng; Liu, Biao; Shi, Ying

    2016-01-01

    Osteosarcoma is the most common type of aggressive bone cancer. Current treatment strategies include surgical resection, radiation, and chemotherapy. Doxorubicin has been widely used as a chemotherapeutic drug to treat osteosarcoma. However, drug resistance has become a challenge to its use. In this study, p53-wild type U2OS and p53-null MG-63 osteosarcoma-derived cells were used to investigate the mechanism of doxorubicin-induced cytotoxicity. In cell viability assays, doxorubicin effectively induced apoptosis in U2OS cells via the p53 signaling pathway, evidenced by elevated PUMA and p21 protein levels and activated caspase 3 cleavage. In contrast, p53-null MG-63 cells were resistant to doxorubicin-induced apoptosis, while exogenous expression of p53 increased drug sensitivity in those cells. The role of TGF-β/Smad3 signaling was investigated by using TGF-β reporter luciferase assays. Doxorubicin was able to induce TGF-β signal transduction without increasing TGF-β production in the presence of p53. Knockdown of Smad3 expression by small hairpin RNA (shRNA) showed that Smad3 was required for p53-mediated TGF-β signaling in response to doxorubicin treatment in U2OS and MG-63 cells. Taken together, these data demonstrate that p53 and TGF-β/Smad3 signaling pathways are both essential for doxorubicin-induced cytotoxicity in osteosarcoma cells. PMID:27073729

  17. Suppressing cyclooxygenase-2 prevents nonalcoholic and inhibits apoptosis of hepatocytes that are involved in the Akt/p53 signal pathway.

    PubMed

    Wu, Jialing; Chen, Chong; Hu, Xi; Cai, Xianbin; Guan, Yinghong; Hu, Hui; Wang, Qinjia; Chen, Xiaofeng; Cai, Bozhi; Jing, Xubin

    2016-01-22

    Cyclooxygenase-2 (COX-2) can exert pro-inflammatory effects in nonalcoholic steatohepatitis (NASH). The aim of this study was to determine if the inhibition of COX-2 attenuates hepatocyte apoptosis in steatohepatitis and to examine the underlying molecular mechanism. Male wild type C57BL6/J mice and COX-2 knock out (COX-2-/-) mice were fed a methionine choline deficient (MCD) diet for 3 weeks. The wild type mice were also treated with celecoxib or a combination of celecoxib and a Akt specific inhibitor, miltefosine (MTF). After that, liver histology, serum alanine aminotransferase (ALT) levels, hepatic triglyceride (TG) levels, hepatocyte apoptosis, phosphorylated Akt (Ser473, pAkt) and p53 protein levels in mice livers were assessed. Celecoxib attenuated the severity of liver steatohepatitis and reduced the number of apoptotic cells, accompanied by increasing the activity of Akt and decreasing expression of p53. On the contrary, MTF can abrogate the effects of celecoxib on anti-apoptosis and anti-steatohepatitis. Moreover, the effects on the COX-2-/- mice that were fed the MCD diet were similar to that for celecoxib. The findings suggested that suppressing COX-2 can improve steatohepatitis by inhibiting hepatocyte apoptosis in mice via regulating the Akt/p53 pathway. Celecoxib treatment may be a favorable treatment option for NASH. PMID:26723251

  18. Epoxyeicosatrienoic acids prevent cisplatin-induced renal apoptosis through a p38 mitogen-activated protein kinase-regulated mitochondrial pathway.

    PubMed

    Liu, Yingmei; Lu, Xiaodan; Nguyen, Sinh; Olson, Jean L; Webb, Heather K; Kroetz, Deanna L

    2013-12-01

    Soluble epoxide hydrolase (sEH) catalyzes the conversion of epoxyeicosatrienoic acids into less active eicosanoids, and inhibitors of sEH have anti-inflammatory and antiapoptotic properties. Based on previous observations that sEH inhibition attenuates cisplatin-induced nephrotoxicity by modulating nuclear factor-κB signaling, we hypothesized that this strategy would also attenuate cisplatin-induced renal apoptosis. Inhibition of sEH with AR9273 [1-adamantan-1-yl-3-(1-methylsulfonyl-piperidin-4-yl-urea)] reduced cisplatin-induced apoptosis through mechanisms involving mitochondrial apoptotic pathways and by reducing reactive oxygen species. Renal mitochondrial Bax induction following cisplatin treatment was significantly decreased by treatment of mice with AR9273 and these antiapoptotic effects involved p38 mitogen-activated protein kinase signaling. Similar mechanisms contributed to reduced apoptosis in Ephx2(-/-) mice treated with cisplatin. Moreover, in pig kidney proximal tubule cells, cisplatin-induced mitochondrial trafficking of Bax and cytochrome c, caspase-3 activation, and oxidative stress are significantly attenuated in the presence of epoxyeicosatrienoic acids (EETs). Collectively, these in vivo and in vitro studies demonstrate a role for EETs in limiting cisplatin-induced renal apoptosis. Inhibition of sEH represents a novel therapeutic strategy for protection against cisplatin-induced renal damage. PMID:24092818

  19. Epoxyeicosatrienoic Acids Prevent Cisplatin-Induced Renal Apoptosis through a p38 Mitogen-Activated Protein Kinase–Regulated Mitochondrial Pathway

    PubMed Central

    Liu, Yingmei; Lu, Xiaodan; Nguyen, Sinh; Olson, Jean L.; Webb, Heather K.

    2013-01-01

    Soluble epoxide hydrolase (sEH) catalyzes the conversion of epoxyeicosatrienoic acids into less active eicosanoids, and inhibitors of sEH have anti-inflammatory and antiapoptotic properties. Based on previous observations that sEH inhibition attenuates cisplatin-induced nephrotoxicity by modulating nuclear factor-κB signaling, we hypothesized that this strategy would also attenuate cisplatin-induced renal apoptosis. Inhibition of sEH with AR9273 [1-adamantan-1-yl-3-(1-methylsulfonyl-piperidin-4-yl-urea)] reduced cisplatin-induced apoptosis through mechanisms involving mitochondrial apoptotic pathways and by reducing reactive oxygen species. Renal mitochondrial Bax induction following cisplatin treatment was significantly decreased by treatment of mice with AR9273 and these antiapoptotic effects involved p38 mitogen-activated protein kinase signaling. Similar mechanisms contributed to reduced apoptosis in Ephx2−/− mice treated with cisplatin. Moreover, in pig kidney proximal tubule cells, cisplatin-induced mitochondrial trafficking of Bax and cytochrome c, caspase-3 activation, and oxidative stress are significantly attenuated in the presence of epoxyeicosatrienoic acids (EETs). Collectively, these in vivo and in vitro studies demonstrate a role for EETs in limiting cisplatin-induced renal apoptosis. Inhibition of sEH represents a novel therapeutic strategy for protection against cisplatin-induced renal damage. PMID:24092818

  20. Berberine prevents nitric oxide-induced rat chondrocyte apoptosis and cartilage degeneration in a rat osteoarthritis model via AMPK and p38 MAPK signaling.

    PubMed

    Zhou, Yan; Liu, Shi-Qing; Yu, Ling; He, Bin; Wu, Shi-Hao; Zhao, Qi; Xia, Shao-Qiang; Mei, Hong-Jun

    2015-09-01

    Chondrocyte apoptosis is an important mechanism involved in osteoarthritis (OA). Berberine (BBR), a plant alkaloid derived from Chinese medicine, is characterized by multiple pharmacological effects, such as anti-inflammatory and anti-apoptotic activities. This study aimed to evaluate the chondroprotective effect and underlying mechanisms of BBR on sodium nitroprusside (SNP)-stimulated chondrocyte apoptosis and surgically-induced rat OA model. The in vitro results revealed that BBR suppressed SNP-stimulated chondrocyte apoptosis as well as cytoskeletal remodeling, down-regulated expressions of inducible nitric oxide synthase (iNOS) and caspase-3, and up-regulated Bcl-2/Bax ratio and Type II collagen (Col II) at protein levels, which were accompanied by increased adenosine monophosphate-activated protein kinase (AMPK) phosphorylation and decreased phosphorylation of p38 mitogen-activated protein kinase (MAPK). Furthermore, the anti-apoptotic effect of BBR was blocked by AMPK inhibitor Compound C (CC) and adenosine-9-β-D-arabino-furanoside (Ara A), and enhanced by p38 MAPK inhibitor SB203580. In vivo experiment suggested that BBR ameliorated cartilage degeneration and exhibited an anti-apoptotic effect on articular cartilage in a rat OA model, as demonstrated by histological analyses, TUNEL assay and immunohistochemical analyses of caspase-3, Bcl-2 and Bax expressions. These findings suggest that BBR suppresses SNP-stimulated chondrocyte apoptosis and ameliorates cartilage degeneration via activating AMPK signaling and suppressing p38 MAPK activity. PMID:26184498

  1. Leishmania donovani prevents oxidative burst-mediated apoptosis of host macrophages through selective induction of suppressors of cytokine signaling (SOCS) proteins.

    PubMed

    Srivastav, Supriya; Basu Ball, Writoban; Gupta, Purnima; Giri, Jayeeta; Ukil, Anindita; Das, Pijush K

    2014-01-10

    One of the mechanisms for establishment of infection employed by intra-macrophage pathogen-like Leishmania is inhibition of oxidative burst-mediated macrophage apoptosis to protect their niche for survival and replication. We tried to elucidate the underlying mechanism for this by using H2O2 for induction of apoptosis. Leishmania donovani-infected macrophages were much more resistant to H2O2-mediated apoptosis compared with control. Although infected cells were capable of comparable reactive oxygen species production, there was less activation of the downstream cascade consisting of caspase-3 and -7 and cleaved poly(ADP)-ribose polymerase. Suppressors of cytokine signaling (SOCS) 1 and 3 proteins and reactive oxygen species scavenging enzyme thioredoxin, known to be involved in stabilization of protein-tyrosine phosphatases, were found to be induced during infection. Induction of SOCS proteins may be mediated by Egr1, and silencing of Socs1 and -3 either alone or in combination resulted in reduced thioredoxin levels, enhanced activation of caspases, and increased apoptosis of infected macrophages. The induction of protein-tyrosine phosphatases, thioredoxin, SOCS, and Egr1 in L. donovani-infected macrophages was found to be unaffected by H2O2 treatment. SOCS knocked down cells also displayed decreased parasite survival thus marking reduction in disease progression. Taken together, these results suggest that L. donovani may exploit SOCS for subverting macrophage apoptotic machinery toward establishing its replicative niche inside the host. PMID:24275663

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

    PubMed Central

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

    2016-01-01

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

  3. C1, a highly potent novel curcumin derivative, binds to tubulin, disrupts microtubule network and induces apoptosis

    PubMed Central

    Srivastava, Shalini; Mishra, Satyendra; Surolia, Avadhesha; Panda, Dulal

    2016-01-01

    We have synthesized a curcumin derivative, 4-{5-(4-hydroxy-3-methoxy-phenyl)-2-[3-(4-hydroxy-3-methoxy-phenyl)-acryloyl]-3-oxo-penta-1,4-dienyl}-piperidine-1-carboxylic acid tert-butyl ester (C1) that displays much stronger antiproliferative activity against various types of cancer cells including multidrug resistance cells than curcumin. C1 depolymerized both interphase and mitotic microtubules in MCF-7 cells and also inhibited the reassembly of microtubules in these cells. C1 inhibited the polymerization of purified tubulin, disrupted the lattice structure of microtubules and suppressed their GTPase activity in vitro. The compound bound to tubulin with a dissociation constant of 2.8±1 μM and perturbed the secondary structures of tubulin. Further, C1 treatment reduced the expression of Bcl2, increased the expression of Bax and down regulated the level of a key regulator of p53, murine double minute 2 (Mdm2) (S166), in MCF-7 cells. C1 appeared to induce p53 mediated apoptosis in MCF-7 cells. Interestingly, C1 showed more stability in aqueous buffer than curcumin. The results together showed that C1 perturbed microtubule network and inhibited cancer cells proliferation more efficiently than curcumin. The strong antiproliferative activity and improved stability of C1 indicated that the compound may have a potential as an anticancer agent. PMID:26980197

  4. Chrysin abrogates early hepatocarcinogenesis and induces apoptosis in N-nitrosodiethylamine-induced preneoplastic nodules in rats

    SciTech Connect

    Khan, Mahaboob S.; Devaraj, Halagowder; Devaraj, Niranjali

    2011-02-15

    Flavonoids possess strong anti-oxidant and cancer chemopreventive activities. Chrysin (5,7-dihydroxyflavone) occurs naturally in many plants, honey, and propolis. In vitro, chrysin acts as a general anti-oxidant, causes cell cycle arrest and promotes cell death. However, the mechanism by which chrysin inhibits cancer cell growth and the subcellular pathways activated remains poorly understood. Effect of dietary supplementation with chrysin on proliferation and apoptosis during diethylnitrosamine (DEN)-induced early hepatocarcinogenesis was investigated in male Wistar rats. To induce hepatocarcinogenesis, rats were given DEN injections (i.p., 200 mg/kg) three times at a 15 day interval. An oral dose of chrysin (250 mg/kg bodyweight) was given three times weekly for 3 weeks, commencing 1 week after the last dose of DEN. Changes in the mRNA expression of COX-2, NFkB p65, p53, Bcl-xL and {beta}-arrestin-2 were assessed by quantitative real-time PCR. Changes in the protein levels were measured by western blotting. Chrysin administration significantly (P < 0.001) reduced the number and size of nodules formed. Also, a significant (P < 0.01) reduction in serum activities of AST, ALT, ALP, LDH and {gamma}GT was noticed. Expression of COX-2 and NFkB p65 was significantly reduced whereas that of p53, Bax and caspase 3 increased at the mRNA and protein levels. Likewise, a decrease in levels of {beta}-arrestin and the anti-apoptotic marker Bcl-xL was also noted. These findings suggest that chrysin exerts global hepato-protective effect and its chemopreventive activity is associated with p53-mediated apoptosis during early hepatocarcinogenesis.

  5. Nuclear translocation of annexin 1 following oxygen-glucose deprivation-reperfusion induces apoptosis by regulating Bid expression via p53 binding.

    PubMed

    Li, Xing; Zhao, Yin; Xia, Qian; Zheng, Lu; Liu, Lu; Zhao, Baoming; Shi, Jing

    2016-01-01

    Previous data have suggested that the nuclear translocation of annexin 1 (ANXA1) is involved in neuronal apoptosis after ischemic stroke. As the mechanism and function of ANXA1 nuclear migration remain unclear, it is important to clarify how ANXA1 performs its role as an apoptosis 'regulator' in the nucleus. Here we report that importazole (IPZ), an importin β (Impβ)-specific inhibitor, decreased ANXA1 nuclear accumulation and reduced the rate of neuronal death induced by nuclear ANXA1 migration after oxygen-glucose deprivation-reoxygenation (OGD/R). Notably, ANXA1 interacted with the Bid (BH3-interacting-domain death agonist) promoter directly; however; this interaction could be partially blocked by the p53 inhibitor pifithrin-α (PFT-α). Accordingly, ANXA1 was shown to interact with p53 in the nucleus and this interaction was enhanced following OGD/R. A luciferase reporter assay revealed that ANXA1 was involved in the regulation of p53-mediated transcriptional activation after OGD/R. Consistent with this finding, the nuclear translocation of ANXA1 after OGD/R upregulated the expression of Bid, which was impeded by IPZ, ANXA1 shRNA, or PFT-α. Finally, cell-survival testing demonstrated that silencing ANXA1 could improve the rate of cell survival and decrease the expression of both cleaved caspase-3 and cleaved poly(ADP-ribose) polymerase. These data suggested that Impβ-dependent nuclear ANXA1 migration participates in the OGD/R-dependent induction of neuronal apoptosis. ANXA1 interacts with p53 and promotes p53 transcriptional activity, which in turn regulates Bid expression. Silencing ANXA1 decreases the expression of Bid and suppresses caspase-3 pathway activation, thus improving cell survival after OGD/R. This study provides a novel mechanism whereby ANXA1 regulates apoptosis, suggesting the potential for a previously unidentified treatment strategy in minimizing apoptosis after OGD/R. PMID:27584794

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

    PubMed

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

    2016-02-01

    Advanced glycation end-products (AGE) and the receptor for AGE (RAGE) have been linked to numerous diabetic vascular complications. RAGE activation promotes a self-sustaining state of chronic inflammation and has been shown to induce apoptosis in various cell types. Although previous studies in vascular smooth muscle cells (VSMC) showed that RAGE activation increases vascular calcification and interferes with their contractile phenotype, little is known on the potential of RAGE to induce apoptosis in VSMC. Using a combination of apoptotic assays, we showed that RAGE stimulation with its ligand CML-HSA promotes apoptosis of VSMC. The formation of stress granules and the increase in the level of the associated protein HuR point toward RAGE-dependent endoplasmic reticulum (ER) stress, which is proposed as a key contributor of RAGE-induced apoptosis in VSMC as it has been shown to promote cell death via numerous mechanisms, including up-regulation of caspase-9. Chronic NF-κB activation and modulation of Bcl-2 homologs are also suspected to contribute to RAGE-dependent apoptosis in VSMC. With the goal of reducing RAGE signaling and its detrimental impact on VSMC, we designed a RAGE antagonist (iRAGE) derived from the primary amino acid sequence of HSA. The resulting CML peptide was selected for the high glycation frequency of the primary sequence in the native protein in vivo. Pretreatment with iRAGE blocked 69.6% of the increase in NF-κB signaling caused by RAGE activation with CML-HSA after 48h. Preincubation with iRAGE was successful in reducing RAGE-induced apoptosis, as seen through enhanced cell survival by SPR and reduced PARP cleavage. Activation of executioner caspases was 63.5% lower in cells treated with iRAGE before stimulation with CML-HSA. To our knowledge, iRAGE is the first antagonist shown to block AGE-RAGE interaction and we propose the molecule as an initial candidate for drug discovery. PMID:26707030

  7. 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

  8. Mortalin, Apoptosis, and Neurodegeneration

    PubMed Central

    Londono, Carolina; Osorio, Cristina; Gama, Vivian; Alzate, Oscar

    2012-01-01

    Mortalin is a highly conserved heat-shock chaperone usually found in multiple subcellular locations. It has several binding partners and has been implicated in various functions ranging from stress response, control of cell proliferation, and inhibition/prevention of apoptosis. The activity of this protein involves different structural and functional mechanisms, and minor alterations in its expression level may lead to serious biological consequences, including neurodegeneration. In this article we review the most current data associated with mortalin’s binding partners and how these protein-protein interactions may be implicated in apoptosis and neurodegeneration. A complete understanding of the molecular pathways in which mortalin is involved is important for the development of therapeutic strategies for cancer and neurodegenerative diseases. PMID:24970131

  9. Minocycline prevents morphine-induced apoptosis in rat cerebral cortex and lumbar spinal cord: a possible mechanism for attenuating morphine tolerance.

    PubMed

    Hassanzadeh, Kambiz; Habibi-asl, Bohlool; Farajnia, Safar; Roshangar, Leila

    2011-05-01

    Tolerance to the chronic administration of opioids such as morphine reduces the utility of these drugs in pain management. Despite significant investigation, the precise cellular mechanisms underlying opioid tolerance and dependence remain elusive. It has been indicated that tolerance to the analgesic effect of morphine is associated with apoptosis in the central nervous system. The aim of this study was to examine the effects of the intracerebroventricular (icv) administration of minocycline (a second-generation tetracycline) on morphine-induced apoptosis in the cerebral cortex and lumbar spinal cord of rats after morphine-induced tolerance. Different groups of rats received either morphine (ip) and distilled water (icv) or morphine and different doses of minocycline (icv) or minocycline alone once per day. The terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) method was used to analyze apoptosis. The anti-apoptotic factors, Bcl-2 and HSP 70 and the pro-apoptotic element caspase-3 were evaluated by immunoblotting. The results indicated that minocycline attenuated the number of apoptotic cells in both the cerebral cortex and lumbar spinal cord. Immunoblotting findings showed that the amounts of anti-apoptotic agents (Bcl-2 and HSP 70) were greater in the treatment groups than in the controls in both regions. Although minocycline did not change the level of caspase-3 at the doses used with morphine but the minocycline treated rats showed a significantly lower increase in caspase-3 activity than did in the control. In conclusion, minocycline decreased the number of TUNEL-positive cells and increased the amount of anti-apoptotic factors (Bcl-2 and HSP 70), but did not change the caspase-3 content. PMID:20711699

  10. IP3 receptor antagonist, 2-APB, attenuates cisplatin induced Ca2+-influx in HeLa-S3 cells and prevents activation of calpain and induction of apoptosis

    PubMed Central

    Splettstoesser, F; Florea, A-M; Büsselberg, D

    2007-01-01

    Background and purpose: Cisplatin drives specific types of tumour cells to apoptosis. In this study we investigate the involvement of intracellular calcium ([Ca2+]i) in triggering apoptosis in two different cell lines. As cisplatin is used for the treatment of several forms of cancer we choose HeLa-S3 and U2-OS as two examples of tumour cell lines. Experimental approach: Cisplatin (1nM–10μM) was applied to HeLa-S3 and U2-OS cells and [Ca2+]i measured with fluo-4, using laser scanning microscopy. Inositol-1,4,5-trisphosphate (IP3) receptors were visualized with immunostaining. Membrane conductances were measured with patch-clamp techniques. Levels of calpain and caspases were assessed by western blots and apoptotic cells were stained with Hoechst 33342 and counted. Key results: Cisplatin increases [Ca2+]i concentration-dependently in HeLa-S3 but not in U2-OS cells. This elevation of [Ca2+]i depended on extracellular Ca2+ but was reduced by the IP3 receptor blocker, 2-APB. This effect was not due to a Ca2+ release triggered by Ca2+ entry. Immunostaining showed IP3-receptors (type1-3) at the cellular membrane of HeLa-S3 cells, but not in U2-OS cells. Electrophysiological experiments showed an increased membrane conductance with cisplatin only when Ca2+ was present extracellularly. Increase of [Ca2+]i was related to the activation of calpain but not caspase-8 and triggered apoptosis in HeLa-S3 but not in U2-OS cells. Conclusions and implications: Our observations on the activation of IP3-receptors, calcium entry and apoptotic rate by cisplatin in specific carcinogenic cells might open new possibilities in the treatment of some forms of cancer. PMID:17592515

  11. Death-Defining Immune Responses After Apoptosis

    PubMed Central

    Campisi, L.; Cummings, R. J.; Blander, J. Magarian

    2014-01-01

    Apoptosis is a programmed form of cell death whereby characteristic internal cellular dismantling is accompanied by the preservation of plasma membrane integrity. Maintaining this order during apoptosis prevents the release of cellular contents and ensures a noninflammatory death. Here, we consider examples of apoptosis in different contexts and discuss how the same form of cell death could have different immunological consequences. Multiple parameters such as cell death as a result of microbial infection, the nature of the inflammatory microenvironment, the type of responding phagocytic cells and the genetic background of the host organism all differentially influence the immunological consequences of apoptosis. PMID:24903539

  12. 10-Hydroxycamptothecin induces apoptosis in human neuroblastoma SMS-KCNR cells through p53, cytochrome c and caspase 3 pathways.

    PubMed

    Yuan, Z F; Tang, Y M; Xu, X J; Li, S S; Zhang, J Y

    2016-01-01

    Neuroblastoma (NB), the most common extracranial solid tumor in childhood, remains one of the most challenging types of cancer to treat. Therefore, the search for novel effective drugs for its treatment is essential. The present study used 10-hydroxycamptothecin (HCPT), which is a naturally occurring alkaloid anticancer agent extracted from the Chinese tree, Camptotheca acuminata, and has a strong anticancer activity in vitro and in vivo. HCPT is able to induce apoptosis in cells of various tumor types. However, few studies have been conducted on its efficacy in NB, and its apoptosis-inducing mechanism has not been elucidated. In the present study, the in vitro effects of HCPT on apoptosis in the human NB cell line, SMS-KCNR, and its underlying molecular mechanisms were investigated. Cell proliferation was measured by an MTT assay and apoptosis was measured using DAPI staining and flow cytometric analysis. In addition, western blot analysis was used to evaluate the apoptosis-associated signaling pathways. HCPT was observed to markedly inhibit cell proliferation and induce apoptosis in SMS-KCNR cells at a relatively low concentration (2.5-20 nM). DAPI staining revealed typical apoptotic feature, namely apoptotic body formation. The flow cytometric analysis revealed that the number of apoptotic cells increased from 20.89% (for 2.5 nM) to 97.66% (for 20 nM) following HCPT treatment for 48 h. Western blot analysis revealed that p53, cytoplasmic cytochrome c, cleaved caspase-3 and poly ADP-ribose polymerase (PARP) proteins were significantly upregulated, while the mitochondrial cytochrome c and pro-caspase-3 proteins were downregulated. However, the B-cell lymphoma 2 and Bcl-2-associated X proteins were unaffected. The results indicated that HCPT may inhibit proliferation and induce apoptosis in the SMS-KCNR cells. The possible mechanism of apoptosis induction is the p53-mediated mitochondrial apoptotic signaling pathway, which promotes cytochrome c release and

  13. Combined treatment with vitamin C and sulindac synergistically induces p53- and ROS-dependent apoptosis in human colon cancer cells.

    PubMed

    Gong, Eun-Yeung; Shin, Yu Jin; Hwang, Ih-Yeon; Kim, Jeong Hee; Kim, Seung-Mi; Moon, Jai-Hee; Shin, Jae-Sik; Lee, Dae-Hee; Hur, Dae Young; Jin, Dong-Hoon; Hong, Seung-Woo; Lee, Won Keun; Lee, Wang-Jae

    2016-09-01

    Sulindac has anti-neoplastic properties against colorectal cancers; however, its use as a chemopreventive agent has been limited due to toxicity and efficacy concerns. Combinatorial treatment of colorectal cancers has been attempted to maximize anti-cancer efficacy with minimal side effects by administrating NSAIDs in combination with other inhibitory compounds or drugs such as l-ascorbic acid (vitamin C), which is known to exhibit cytotoxicity towards various cancer cells at high concentrations. In this study, we evaluated a combinatorial strategy utilizing sulindac and vitamin C. The death of HCT116 cells upon combination therapy occurred via a p53-mediated mechanism. The combination therapeutic resistance developed in isogenic p53 null HCT116 cells and siRNA-mediated p53 knockdown HCT116 cells, but the exogenous expression of p53 in p53 null isogenic cells resulted in the induction of cell death. In addition, we investigated an increased level of intracellular ROS (reactive oxygen species), which was preceded by p53 activation. The expression level of PUMA (p53-upregulated modulator of apoptosis), but not Bim, was significantly increased in HCT116 cells in response to the combination treatment. Taken together, our results demonstrate that combination therapy with sulindac and vitamin C could be a novel anti-cancer therapeutic strategy for p53 wild type colon cancers. PMID:27339904

  14. The nucleoprotein of influenza A virus induces p53 signaling and apoptosis via attenuation of host ubiquitin ligase RNF43

    PubMed Central

    Nailwal, H; Sharma, S; Mayank, A K; Lal, S K

    2015-01-01

    The interplay between influenza virus and host factors to support the viral life cycle is well documented. Influenza A virus (IAV) proteins interact with an array of cellular proteins and hijack host pathways which are at the helm of cellular responses to facilitate virus invasion. The multifaceted nature of the ubiquitination pathway for protein regulation makes it a vulnerable target of many viruses including IAV. To this end we conducted a yeast two-hybrid screen to search for cellular ubiquitin ligases important for influenza virus replication. We identified host protein, RING finger protein 43 (RNF43), a RING-type E3 ubiquitin ligase, as a novel interactor of nucleoprotein (NP) of IAV and an essential partner to induce NP-driven p53-mediated apoptosis in IAV-infected cells. In this study, we demonstrate that IAV leads to attenuation of RNF43 transcripts and hence its respective protein levels in the cellular milieu whereas in RNF43 depleted cells, viral replication was escalated several folds. Moreover, RNF43 polyubiquitinates p53 which further leads to its destabilization resulting in a decrease in induction of the p53 apoptotic pathway, a hitherto unknown process targeted by NP for p53 stabilization and accumulation. Collectively, these results conclude that NP targets RNF43 to modulate p53 ubiquitination levels and hence causes p53 stabilization which is conducive to an enhanced apoptosis level in the host cells. In conclusion, our study unravels a novel strategy adopted by IAV for utilizing the much conserved ubiquitin proteasomal pathway. PMID:25996295

  15. Mouse keratinocytes express c98, a novel gene homologous to bcl-2, that is stimulated by insulin-like growth factor 1 and prevents dexamethasone-induced apoptosis.

    PubMed

    Su, Hung-Yi; Cheng, Winston T K; Chen, Shih-Chu; Lin, Chen-Tse; Lien, Yi-Yang; Liu, Hung-Jen; Gilmour, R Stewart

    2004-01-20

    Many studies have been undertaken to investigate the mechanisms of skin differentiation. In particular, growth factors and hormones are believed to play important roles in skin proliferation, differentiation and survival. Insulin-like growth factor-1 (IGF-1) has been identified as a survival factor in many tissues including the skin, but the molecular mechanism of IGF-1 in epidermal differentiation is not completely understood. Neonatal mouse skin is useful for studying changes in gene expression, as the mitotic activity of skin cells changes shortly after birth. Using RNA differential display (DD), a 357-nt message that is specifically expressed in the epidermal keratinocytes of IGF-1-injected newborn mice but not in controls, has been identified. Confirmation of expression of this gene by ribonuclease protection assay (RPA) showed that its mRNA expression in the epidermal keratinocytes is induced by IGF-1. Using RNA ligase-mediated rapid amplification of 5' cDNA ends (RLM-5'-RACE), we have successfully isolated a 3473-bp full-length gene, c98, that has 97% sequence homology to a bcl-2-like gene, bcl-w. The latter has been identified as a proto-oncogene in several murine myeloid cell lines. Amino acid sequence analysis of the c98 showed that it has 97% sequence identity to the bcl-w protein and possesses bcl-2 homology domains (BH) 1, 2 and 3. Immunoblotting data revealed similar increases of c98 protein expression to its mRNA expression in the keratinocytes of IGF-1-injected animals. Weak expression of other bcl-2 family member proteins, bax, bcl-2 and bcl-xL, were also found in the immunoblots. Additionally, IGF-1 was found to be able to protect epidermal keratinocytes from dexamethasone (DEX)-induced apoptosis, based on the findings that after the cells were treated with DEX, DNA laddering was present in the control mice but not in those injected with IGF-1. Further, using a photometric enzyme-linked immunoassay to quantitate keratinocyte death, we found that

  16. NF-κB inhibition significantly upregulates the norepinephrine transporter system, causes apoptosis in pheochromocytoma cell lines and prevents metastasis in an animal model.

    PubMed

    Pacak, Karel; Sirova, Marta; Giubellino, Alessio; Lencesova, Lubomira; Csaderova, Lucia; Laukova, Marcela; Hudecova, Sona; Krizanova, Olga

    2012-11-15

    Pheochromocytomas (PHEOs) and paragangliomas (PGLs) are specific types of neuroendocrine tumors that originate in the adrenal medulla or sympathetic/parasympathetic paraganglia, respectively. Although these tumors are intensively studied, a very effective treatment for metastatic PHEO or PGL has not yet been established. Preclinical evaluations of novel therapies for these tumors are very much required. Therefore, in this study we tested the effect of triptolide (TTL), a potent nuclear factor-kappaB (NF-κB) inhibitor, on the cell membrane norepinephrine transporter (NET) system, considered to be the gatekeeper for the radiotherapeutic agent 131I-metaiodobenzylguanidine (131I-MIBG). We measured changes in the mRNA and protein levels of NET and correlated them with proapoptotic factors and metastasis inhibition. The study was performed on three different stable PHEO cell lines. We found that blocking NF-κB with TTL or capsaicin increased both NET mRNA and protein levels. Involvement of NF-κB in the upregulation of NET was verified by mRNA silencing of this site and also by using NF-κB antipeptide. Moreover, in vivo treatment with TTL significantly reduced metastatic burden in an animal model of metastatic PHEO. The present study for the first time shows how NF-κB inhibitors could be successfully used in the treatment of metastatic PHEO/PGL by a significant upregulation of NET to increase the efficacy of 131I-MIBG and by the induction of apoptosis. PMID:22407736

  17. Mu-opioid receptor activation prevents apoptosis following serum withdrawal in differentiated SH-SY5Y cells and cortical neurons via phosphatidylinositol 3-kinase.

    PubMed

    Iglesias, M; Segura, M F; Comella, J X; Olmos, G

    2003-03-01

    Opioid peptides and alkaloids exert their effects via G protein-coupled receptors (GPCRs). It has been shown that, in addition to trophic factors, some GPCRs are able to activate the phosphatidylinositol 3-kinase/Akt (PI 3-K/Akt) signal transduction pathway, thus leading to cell survival. The aim of this study was to test whether activation of mu-opioid receptors has protective effects on serum withdrawal-induced cell death and to study the possible implication of PI 3-K in this process. In SH-SY5Y neuroblastoma cells fully differentiated by exposure to retinoic acid for five days, the enkephalin derivative selective mu-agonist DAMGO (0.1-2 microM) and the alkaloid morphine (0.1-10 microM) promoted cell survival after serum deprivation (MTT and trypan blue exclusion assays), without inducing cell proliferation. These effects were fully reversed by naloxone, by the selective mu-antagonist beta-funaltrexamine (beta-FNA) and also by the specific PI 3-K inhibitor LY294002. The two agonists stimulated Akt phosphorylation and the effect was also abolished by beta-FNA and by LY294002. In mouse primary cortical neurons, DAMGO reduced the percentage of apoptosis after 6, 12, 24 and 48 h of serum withdrawal; as determined by Hoechst staining. This effect was blocked by beta-FNA, by pre-treatment with pertussis toxin and by LY294002. DAMGO also stimulated Akt phosphorylation via PI 3-K in this primary neuronal culture. Together, these results indicate that stimulation of the mu-opioid receptor promotes neuronal survival in a G(i/o)-linked, PI 3-K-dependent signaling cascade and suggest that Akt may be a key downstream kinase involved in this anti-apoptotic effect. PMID:12646285

  18. Disruption of the ECM33 gene in Candida albicans prevents biofilm formation, engineered human oral mucosa tissue damage and gingival cell necrosis/apoptosis.

    PubMed

    Rouabhia, Mahmoud; Semlali, Abdelhabib; Chandra, Jyotsna; Mukherjee, Pranab; Chmielewski, Witold; Ghannoum, Mahmoud A

    2012-01-01

    In this study we demonstrated that ΔCaecm33 double mutant showed reduced biofilm formation and causes less damage to gingival mucosa tissues. This was confirmed by the reduced level of necrotic cells and Bax/Bcl2 gene expression as apoptotic markers. In contrast, parental and Caecm33 mutant strains decreased basement membrane protein production (laminin 5 and type IV collagen). We thus propose that ECM33 gene/protein represents a novel target for the prevention and treatment of infections caused by Candida. PMID:22665950

  19. 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

  20. E3 ubiquitin ligase TRIM32 negatively regulates tumor suppressor p53 to promote tumorigenesis.

    PubMed

    Liu, Ju; Zhang, C; Wang, X L; Ly, P; Belyi, V; Xu-Monette, Z Y; Young, K H; Hu, W; Feng, Z

    2014-11-01

    Tumor suppressor p53 has a key role in maintaining genomic stability and preventing tumorigenesis through its regulation of cellular stress responses, including apoptosis, cell cycle arrest and senescence. To ensure its proper levels and functions in cells, p53 is tightly regulated mainly through post-translational modifications, such as ubiquitination. Here, we identified E3 ubiquitin ligase TRIM32 as a novel p53 target gene and negative regulator to regulate p53-mediated stress responses. In response to stress, such as DNA damage, p53 binds to the p53 responsive element in the promoter of the TRIM32 gene and transcriptionally induces the expression of TRIM32 in cells. In turn, TRIM32 interacts with p53 and promotes p53 degradation through ubiquitination. Thus, TRIM32 negatively regulates p53-mediated apoptosis, cell cycle arrest and senescence in response to stress. TRIM32 is frequently overexpressed in different types of human tumors. TRIM32 overexpression promotes cell oncogenic transformation and tumorigenesis in mice in a largely p53-dependent manner. Taken together, our results demonstrated that as a novel p53 target and a novel negative regulator for p53, TRIM32 has an important role in regulation of p53 and p53-mediated cellular stress responses. Furthermore, our results also revealed that impairing p53 function is a novel mechanism for TRIM32 in tumorigenesis. PMID:25146927

  1. Polyploid cells rewire DNA damage response networks to overcome replication stress-induced barriers for tumour progression

    PubMed Central

    Zheng, Li; Dai, Huifang; Zhou, Mian; Li, Xiaojin; Liu, Changwei; Guo, Zhigang; Wu, Xiwei; Wu, Jun; Wang, Charles; Zhong, John; Huang, Qin; Garcia-Aguilar, Julio; Pfeifer, Gerd P.; Shen, Binghui

    2012-01-01

    Mutations in genes involved in DNA replication such as FEN1, can cause single-stranded DNA breaks (SSBs) and subsequent collapse of DNA replication forks leading to DNA replication stresses. Persistent replication stresses normally induce p53-mediated senescence or apoptosis to prevent tumor progression. It is unclear how some mutant cells can overcome persistent replication stresses and bypass the p53-mediated pathways to develop malignancy. Here we show that formation of polyploidy, which is often observed in human cancers, leads to overexpression of BRCA1, p19arf and other DNA repair genes in FEN1 mutant cells. This overexpression triggers SSB repair and non-homologous end joining pathways to increase DNA repair activity, but at the cost of frequent chromosomal translocations. Meanwhile, DNA methylation silences p53 target genes, to bypass the p53-mediated senescence and apoptosis. These molecular changes rewire DNA damage response and repair gene networks in polyploid tumor cells, enabling them to escape replication stress-induced senescence barriers. PMID:22569363

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

    PubMed

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

    2015-01-01

    Type 2 diabetes mellitus has been known to increase systemic oxidative stress by chronic hyperglycemia and visceral obesity and aggravate cerebral ischemic injury. On the basis of our previous study regarding a water-soluble extract from the culture medium of Ganoderma lucidum mycelia (designed as MAK), which exerts antioxidative and neuroprotective effects, the present study was conducted to evaluate the preventive effects of MAK on apoptosis and necroptosis (a programmed necrosis) induced by hypoxia/ischemia (H/I) in type 2 diabetic KKAy mice. H/I was induced by a combination of unilateral common carotid artery ligation with hypoxia (8% O2 for 20 min) and subsequent reoxygenation. Pretreatment with MAK (1 g/kg, p.o.) for a week significantly reduced H/I-induced neurological deficits and brain infarction volume assessed at 24 h of reoxygenation. Histochemical analysis showed that MAK significantly suppressed superoxide production, neuronal cell death, and vacuolation in the ischemic penumbra, which was accompanied by a decrease in the numbers of TUNEL- or cleaved caspase-3-positive cells. Furthermore, MAK decreased the expression of receptor-interacting protein kinase 3 mRNA and protein, a key molecule for necroptosis. These results suggest that MAK confers resistance to apoptotic and necroptotic cell death and relieves H/I-induced cerebral ischemic injury in type 2 diabetic mice. PMID:25945116

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

    PubMed Central

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

    2015-01-01

    Type 2 diabetes mellitus has been known to increase systemic oxidative stress by chronic hyperglycemia and visceral obesity and aggravate cerebral ischemic injury. On the basis of our previous study regarding a water-soluble extract from the culture medium of Ganoderma lucidum mycelia (designed as MAK), which exerts antioxidative and neuroprotective effects, the present study was conducted to evaluate the preventive effects of MAK on apoptosis and necroptosis (a programmed necrosis) induced by hypoxia/ischemia (H/I) in type 2 diabetic KKAy mice. H/I was induced by a combination of unilateral common carotid artery ligation with hypoxia (8% O2 for 20 min) and subsequent reoxygenation. Pretreatment with MAK (1 g/kg, p.o.) for a week significantly reduced H/I-induced neurological deficits and brain infarction volume assessed at 24 h of reoxygenation. Histochemical analysis showed that MAK significantly suppressed superoxide production, neuronal cell death, and vacuolation in the ischemic penumbra, which was accompanied by a decrease in the numbers of TUNEL- or cleaved caspase-3-positive cells. Furthermore, MAK decreased the expression of receptor-interacting protein kinase 3 mRNA and protein, a key molecule for necroptosis. These results suggest that MAK confers resistance to apoptotic and necroptotic cell death and relieves H/I-induced cerebral ischemic injury in type 2 diabetic mice. PMID:25945116

  4. HDM4 is overexpressed in mantle cell lymphoma and its inhibition induces p21 expression and apoptosis.

    PubMed

    Liang, Mei; Han, Xin; Vadhan-Raj, Saroj; Nguyen, Martin; Zhang, Yu H; Fernandez, Michael; Drakos, Elias; Konoplev, Sergej N; Yin, C Cameron; Miranda, Roberto N; McDonnell, Timothy J; Medeiros, L Jeffrey; Bueso-Ramos, Carlos E

    2010-03-01

    In mouse models and cell lines, murine double minute 2 (MDM2) and MDM4 have been shown to synergistically promote proteasome-mediated degradation of p21 and p53. MDM4 also inhibits p53-mediated transcriptional activation of p21. p53 expression results in increased p21 expression, a negative cell-cycle regulatory protein and an inhibitor of cyclin D1. As mantle cell lymphoma is characterized by cyclin D1 overexpression, we assessed for human homolog of MDM4 (HDM4) expression and its effect on p21 in mantle cell lymphoma. Using immunohistochemical methods, in reactive lymph nodes (n=19) germinal center cells strongly expressed HDM4 in the nucleus and the cytoplasm, but mantle zone B-cells were only dimly positive. In mantle cell lymphoma tumors, aberrant HDM4 nuclear expression was observed in 18 of 19 (95%) cases. In contrast, HDM4 in other B-cell non-Hodgkin lymphoma types retained its normal pattern of expression. To further characterize the differential upregulation of HDM4 in mantle cell lymphoma, HDM4 was assessed by quantitative real-time polymerase chain reaction in four mantle cell lymphoma cell lines (Granta 519, Z-138, SP-53, and Mino) and six mantle cell lymphoma tumors. Both the splicing variant HDM4-S, containing only the p53-binding domain, and full length HDM4 were increased compared with normal CD19+ B-cells (P<0.05). Using small interfering RNA to inhibit HDM4 in the SP53 and Mino cell lines showed increased p21 and active caspase-3, the latter indicating increased apoptosis. Our results show that HDM4 is overexpressed in mantle cell lymphoma and, at least in part, exerts its effect by suppressing p21 expression, thereby enhancing cell-cycle progression. Inhibition of HDM4 may serve as a potential approach in the design of therapy for patients with mantle cell lymphoma. PMID:20062013

  5. DNA damage, redox changes, and associated stress-inducible signaling events underlying the apoptosis and cytotoxicity in murine alveolar macrophage cell line MH-S by methanol-extracted Stachybotrys chartarum toxins

    SciTech Connect

    Wang Huiyan; Yadav, Jagjit S. . E-mail: Jagjit.Yadav@uc.edu

    2006-08-01

    Spore-extracted toxins of the indoor mold Stachybotrys chartarum (SC) caused cytotoxicity (release of lactate dehydrogenase), inhibition of cell proliferation, and cell death in murine alveolar macrophage cell line MH-S in a dose- and time-dependent manner. Apoptotic cell death, confirmed based on morphological changes, DNA ladder formation, and caspase 3/7 activation, was detectable as early as at 3 h during treatment with a toxin concentration of 1 spore equivalent/macrophage and was preceded by DNA damage beginning at 15 min, as evidenced by DNA comet formation in single cell gel electrophoresis assay. The apoptotic dose of SC toxins did not induce detectable nitric oxide and pro-inflammatory cytokines (IL-1{beta}, IL-6, and TNF-{alpha}) but showed exacerbated cytotoxicity in presence of a non-apoptotic dose of the known pro-inflammatory agent LPS (10 ng/ml). Intracellular reduced glutathione (GSH) level showed a significant decrease beginning at 9 h of the toxin treatment whereas oxidized glutathione (GSSG) showed a corresponding significant increase, indicating a delayed onset of oxidative stress in the apoptosis process. The toxin-treated macrophages accumulated p53, an indicator of DNA damage response, and showed activation of the stress-inducible MAP kinases, JNK, and p38, in a time-dependent manner. Chemical blocking of either p38 or p53 inhibited in part the SC toxin-induced apoptosis whereas blocking of JNK did not show any such effect. This study constitutes the first report on induction of DNA damage and associated p53 activation by SC toxins, and demonstrates the involvement of p38- and p53-mediated signaling events in SC toxin-induced apoptosis of alveolar macrophages.

  6. The Src and c-Kit kinase inhibitor dasatinib enhances p53-mediated targeting of human acute myeloid leukemia stem cells by chemotherapeutic agents

    PubMed Central

    Dos Santos, Cedric; McDonald, Tinisha; Ho, Yin Wei; Liu, Hongjun; Lin, Allen; Forman, Stephen J.; Kuo, Ya-Huei

    2013-01-01

    The SRC family kinases (SFKs) and the receptor tyrosine kinase c-Kit are activated in human acute myeloid leukemia (AML) cells. We show here that the SFKs LYN, HCK, or FGR are overexpressed and activated in AML progenitor cells. Treatment with the SFK and c-KIT inhibitor dasatinib selectively inhibits human AML stem/progenitor cell growth in vitro. Importantly, dasatinib markedly increases the elimination of AML stem cells capable of engrafting immunodeficient mice by chemotherapeutic agents. In vivo dasatinib treatment enhances chemotherapy-induced targeting of primary murine AML stem cells capable of regenerating leukemia in secondary recipients. Our studies suggest that enhanced targeting of AML cells by the combination of dasatinib with daunorubicin may be related to inhibition of AKT-mediated human mouse double minute 2 homolog phosphorylation, resulting in enhanced p53 activity in AML cells. Combined treatment using dasatinib and chemotherapy provides a novel approach to increasing p53 activity and enhancing targeting of AML stem cells. PMID:23896410

  7. HPV E6/p53 mediated down-regulation of miR-34a inhibits Warburg effect through targeting LDHA in cervical cancer

    PubMed Central

    Zhang, Rong; Su, Jing; Xue, Song-Lin; Yang, Hui; Ju, Li-Li; Ji, Ying; Wu, Kai-Hua; Zhang, Yan-Wei; Zhang, Ye-Xin; Hu, Jian-Fang; Yu, Min-Min

    2016-01-01

    MicroRNAs (miRNA) play crucial roles in regulating cell proliferation, differentiation and developmental timing. Aberrantly expressed miRNAs have recently emerged as key regulators of metabolism. However, little is known about its role in tumor metabolism of cervical cancer. In this study, we determined the oncogenic effects of miRNAs on Warburg effect, a metabolic phenotype that allows cancer cells to utilize glucose even under aerobic conditions. A gain-of-function study was performed in 12 down-regulated miRNAs that frequently reported in cervical cancer. We found that miR-34a plays a suppressive role in Warburg effect as evidenced by decreased lactate production and glucose consumption. Knockdown of oncoprotein E6 expression of human papillomavirus in SiHa and HeLa cells by siRNAs lead to an increased protein level of p53, decreased level of miR-34a, as well as reduced Warburg effect. Subsequently, lactate dehydrogenase A (LDHA), which catalyzes the last key step in glycolysis, was identified as a direct target of miR-34a. Silencing of LDHA or introduction of miR-34a significantly attenuated colony formation ability and invasive capacity of SiHa and HeLa cells, and these effects were fully compromised by reintroduction of LDHA. In conclusion, our findings demonstrated that deregulated miR-34a/LDHA axis induced by HPV E6/p53 signaling facilitates tumor growth and invasion through regulating Warburg effect in cervical cancer, and provided new insights into the mechanism by which miR-34a contributes to the development and progression of cervical cancer.

  8. Microarray and ChIP-seq data analysis revealed changes in p53-mediated transcriptional regulation in Nutlin-3-treated U2OS cells

    PubMed Central

    ZHAO, SONG; NIU, FENG; XU, CHANG-YAN; YE, LONG; BI, GUI-BIN; CHEN, LIN; GONG, PING; TIAN, GANG; NIE, TIAN-HONG

    2015-01-01

    Integrative analysis of chromatin immunoprecipitation-sequencing (ChIP-seq) data and microarray data was performed to illustrate the effect of Nutlin-3 on promoter selectivity and transcriptional regulation by the tumor suppressor p53 in U2OS human osteosarcoma cells. Raw data (accession number, GSE46642) were downloaded from Gene Expression Omnibus. Differential analyses were performed using package limma of R software. Gene ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were performed for the differentially expressed genes (DEGs) using the Database for Annotation, Visualization and Integration Discovery. Integrative analysis of ChIP-seq data and microarray data were confirmed with ChIP-Array. A total of 565 DEGs were identified, including 373 upregulated genes and 192 downregulated genes. Genes involved in the p53 signaling pathway, cell cycle, DNA replication, cytokine-cytokine receptor interaction and melanoma were markedly over-represented in the DEGs. A total of 39 DEGs were directly regulated by p53 and two were the transcription factors (TFs), E2F2 and HOXA1. E2F2 regulated 25 DEGs, while HOXA1 regulated one DEG. The cell cycle, p53 signaling pathway, melanoma and pathways involved in cancer were enriched in the direct and indirect target genes. Changes in the p53-binding pattern induced by Nutlin-3 were described in the present study, which may advance the understanding of the regulatory network of p53 in osteosarcoma and aid in the development of novel therapies. PMID:26080812

  9. Loss of p53-regulatory protein IFI16 induces NBS1 leading to activation of p53-mediated checkpoint by phosphorylation of p53 SER37.

    PubMed

    Tawara, Hideyuki; Fujiuchi, Nobuko; Sironi, Juan; Martin, Sarah; Aglipay, Jason; Ouchi, Mutsuko; Taga, Makoto; Chen, Phang-Lang; Ouchi, Toru

    2008-01-01

    Our previous results that IFI16 is involved in p53 transcription activity under conditions of ionizing radiation (IR), and that the protein is frequently lost in human breast cancer cell lines and breast adenocarcinoma tissues suggesting that IFI16 plays a crucial role in controlling cell growth. Here, we show that loss of IFI16 by RNA interference in cell culture causes elevated phosphorylation of p53 Ser37 and accumulated NBS1 (nibrin) and p21WAF1, leading to growth retardation. Consistent with these observations, doxycyclin-induced NBS1 caused accumulation of p21WAF1 and increased phosphorylation of p53 Ser37, leading to cell cycle arrest in G1 phase. Wortmannin treatment was found to decrease p53 Ser37 phosphorylation in NBS-induced cells. These results suggest that loss of IFI16 activates p53 checkpoint through NBS1-DNA-PKcs pathway. PMID:17981542

  10. Disruption of the p53-mediated G{sub 1}/S cell cycle checkpoint results in elevated rates of spontaneous genetic recombination in human fibroblasts

    SciTech Connect

    Strasfeld, L.; Brainerd, E.; Meyn, M.S.

    1994-09-01

    A key feature of the cancer-prone inherited disease ataxia-telangiectasia (A-T) is genetic instability. We recently demonstrated that one aspect of genetic instability in A-T is a marked elevation in the spontaneous rates of intrachromosomal mitotic recombination. We have proposed a model for A-T that attributes these high recombination rates to a lack of DNA damage-sensitive cell cycle checkpoints. One prediction of this model is that disrupting p53 function in normal cells should increase their spontaneous rates of recombination by interfering with their p53-dependent G{sub 1}/S cell cycle checkpoint. To test this prediction, we transfected control and A-T fibroblast lines that each harbor a single integrated copy of lacZ-based recombination vector (pLrec) with derivatives of a eukaryotic expression vector (pRep5) that contain either a dominant-negative p53 mutant (143{sup val{yields}ala}) or a human papilloma virus E6 gene (HPV18 E6). Expression of either of these genes results in loss of p53 function and abolition of the G{sub 1}/S cell cycle checkpoint. Four independent p53{sup 143ala} transformants of the control line showed 25-80 fold elevations in spontaneous recombination rates when compared to their parent cell line. Elevations in spontaneous recombination rates were also detected following transfection with the HPV18 E6 gene. In contrast, four independent p53{sup 143ala} transformants of the A-T cell line showed no significant changes in their already high spontaneous recombination rates. We are now extending these observations to additional normal human fibroblast lines and carrying out molecular analyses of the products of these recombinational events. Our results support our hypothesis that the lack of a p53-dependent G{sub 1}/S cell cycle checkpoint contributes to the hyperrecombination seen in A-T.

  11. RNA-Binding Protein FXR1 Regulates p21 and TERC RNA to Bypass p53-Mediated Cellular Senescence in OSCC.

    PubMed

    Majumder, Mrinmoyee; House, Reniqua; Palanisamy, Nallasivam; Qie, Shuo; Day, Terrence A; Neskey, David; Diehl, J Alan; Palanisamy, Viswanathan

    2016-09-01

    RNA-binding proteins (RBP) regulate numerous aspects of co- and post-transcriptional gene expression in cancer cells. Here, we demonstrate that RBP, fragile X-related protein 1 (FXR1), plays an essential role in cellular senescence by utilizing mRNA turnover pathway. We report that overexpressed FXR1 in head and neck squamous cell carcinoma targets (G-quadruplex (G4) RNA structure within) both mRNA encoding p21 (Cyclin-Dependent Kinase Inhibitor 1A (CDKN1A, Cip1) and the non-coding RNA Telomerase RNA Component (TERC), and regulates their turnover to avoid senescence. Silencing of FXR1 in cancer cells triggers the activation of Cyclin-Dependent Kinase Inhibitors, p53, increases DNA damage, and ultimately, cellular senescence. Overexpressed FXR1 binds and destabilizes p21 mRNA, subsequently reduces p21 protein expression in oral cancer cells. In addition, FXR1 also binds and stabilizes TERC RNA and suppresses the cellular senescence possibly through telomerase activity. Finally, we report that FXR1-regulated senescence is irreversible and FXR1-depleted cells fail to form colonies to re-enter cellular proliferation. Collectively, FXR1 displays a novel mechanism of controlling the expression of p21 through p53-dependent manner to bypass cellular senescence in oral cancer cells. PMID:27606879

  12. Sphingosine in apoptosis signaling.

    PubMed

    Cuvillier, Olivier

    2002-12-30

    The sphingolipid metabolites ceramide, sphingosine, and sphingosine 1-phosphate contribute to controlling cell proliferation and apoptosis. Ceramide and its catabolite sphingosine act as negative regulators of cell proliferation and promote apoptosis. Conversely, sphingosine 1-phosphate, formed by phosphorylation of sphingosine by a sphingosine kinase, has been involved in stimulating cell growth and inhibiting apoptosis. As the phosphorylation of sphingosine diminishes apoptosis, while dephosphorylation of sphingosine 1-phosphate potentiates it, the role of sphingosine as a messenger of apoptosis is of importance. Herein, the effects of sphingosine on diverse signaling pathways implicated in the apoptotic process are reviewed. PMID:12531549

  13. Research Advances on Pathways of Nickel-Induced Apoptosis

    PubMed Central

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

    2015-01-01

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

  14. Regulation of p53-dependent apoptosis, transcriptional repression, and cell transformation by phosphorylation of the 55-kilodalton E1B protein of human adenovirus type 5.

    PubMed Central

    Teodoro, J G; Branton, P E

    1997-01-01

    The adenovirus type 5 55-kDa E1B protein (E1B-55kDa) cooperates with E1A gene products to induce cell transformation. E1A proteins stimulate DNA synthesis and cell proliferation; however, they also cause rapid cell death by p53-dependent and p53-independent apoptosis. It is believed that the role of the E1B-55kDa protein in transformation is to protect against p53-dependent apoptosis by binding to and inactivating p53. It has been shown previously that the 55-kDa polypeptide abrogates p53-mediated transactivation and that mutants defective in p53 binding are unable to cooperate with E1A in transformation. We have previously mapped phosphorylation sites near the carboxy terminus of the E1B-55kDa protein at Ser-490 and Ser-491, which lie within casein kinase II consensus sequences. Conversion of these sites to alanine residues greatly reduced transforming activity, and although the mutant 55-kDa protein was found to interact with p53 at normal levels, it was somewhat defective for suppression of p53 transactivation activity. We now report that a nearby residue, Thr-495, also appears to be phosphorylated. We demonstrate directly that the wild-type 55-kDa protein is able to block E1A-induced p53-dependent apoptosis, whereas cells infected by mutant pm490/1/5A, which contains alanine residues at all three phosphorylation sites, exhibited extensive DNA fragmentation and classic apoptotic cell death. The E1B-55kDa product has been shown to exhibit intrinsic transcriptional repression activity when localized to promoters, such as by fusion with the GAL4 DNA-binding domain, even in the absence of p53. Such repression activity was totally absent with mutant pm490/1/5A. These data suggested that inhibition of p53-dependent apoptosis may depend on the transcriptional repression function of the 55-kDa protein, which appears to be regulated be phosphorylation at the carboxy terminus. PMID:9094635

  15. 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-α-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

  16. Downregulation of Reactive Oxygen Species in Apoptosis

    PubMed Central

    Jeong, Chul-Ho; Joo, Sang Hoon

    2016-01-01

    Generation of reactive oxygen species (ROS) by diverse anti-cancer drugs or phytochemicals has been closely related with the induction of apoptosis in cancers. Also, the downregulation of ROS by these chemicals has been found to block initiation of carcinogenesis. Therefore, modulation of ROS by phytochemicals emerges as a crucial mechanism to regulate apoptosis in cancer prevention or therapy. This review summarizes the current understanding of the selected chemical compounds and related cellular components that modulate ROS during apoptotic process. Metformin, quercetin, curcumin, vitamin C, and other compounds have been shown to downregulate ROS in the cellular apoptotic process, and some of them even induce apoptosis in cancer cells. The cellular components mediating the downregulation of ROS include nuclear factor erythroid 2-related factor 2 antioxidant signaling pathway, thioredoxin, catalase, glutathione, heme oxygenase-1, and uncoupling proteins. The present review provides information on the relationship between these compounds and the cellular components in modulating ROS in apoptotic cancer cells. PMID:27051644

  17. 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

  18. Lithium protects ethanol-induced neuronal apoptosis

    SciTech Connect

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

    2006-12-01

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

  19. 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

  20. 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

  1. NMR exposure sensitizes tumor cells to apoptosis.

    PubMed

    Ghibelli, L; Cerella, C; Cordisco, S; Clavarino, G; Marazzi, S; De Nicola, M; Nuccitelli, S; D'Alessio, M; Magrini, A; Bergamaschi, A; Guerrisi, V; Porfiri, L M

    2006-03-01

    NMR technology has dramatically contributed to the revolution of image diagnostic. NMR apparatuses use combinations of microwaves over a homogeneous strong (1 Tesla) static magnetic field. We had previously shown that low intensity (0.3-66 mT) static magnetic fields deeply affect apoptosis in a Ca2+ dependent fashion (Fanelli et al., 1999 FASEBJ., 13;95-102). The rationale of the present study is to examine whether exposure to the static magnetic fields of NMR can affect apoptosis induced on reporter tumor cells of haematopoietic origin. The impressive result was the strong increase (1.8-2.5 fold) of damage-induced apoptosis by NMR. This potentiation is due to cytosolic Ca2+ overload consequent to NMR-promoted Ca2+ influx, since it is prevented by intracellular (BAPTA-AM) and extracellular (EGTA) Ca2+ chelation or by inhibition of plasma membrane L-type Ca2+ channels. Three-days follow up of treated cultures shows that NMR decrease long term cell survival, thus increasing the efficiency of cytocidal treatments. Importantly, mononuclear white blood cells are not sensitised to apoptosis by NMR, showing that NMR may increase the differential cytotoxicity of antitumor drugs on tumor vs normal cells. This strong, differential potentiating effect of NMR on tumor cell apoptosis may have important implications, being in fact a possible adjuvant for antitumor therapies. PMID:16528477

  2. Prevention of growth of human lung carcinoma cells and induction of apoptosis by a novel phenoxazinone, 2-amino-4,4alpha-dihydro-4alpha,7-dimethyl-3H-phenoxazine-3-one.

    PubMed

    Abe, A; Yamane, M; Tomoda, A

    2001-04-01

    Anti-tumor effects of a novel phenoxazinone, 2-amino-4,4-dihydro-4alpha,7-dimethyl-3H-phenoxazine-3-one (Phx), which was synthesized by the reaction of 2-amino-5-methylphenol with bovine hemoglobin, were studied in terms of suppression of the proliferation of human lung carcinoma cells and apoptosis induction. When Phx was added to cultures of the human lung carcinoma cell lines A549 (adenocarcinoma) and H226 (squamous carcinoma), it caused the growth inhibition and the death of these cells. Phx also fragmented the DNA of these cells to oligonucleosomal-sized fragments, which is characteristic of the apoptosis, dependent on the dose and exposure time. The cellular death caused by the administration of Phx was partially reversed by the addition of Z-VAD-fmk, a caspase family inhibitor. Present results suggest that Phx demonstrates anti-cancer activity against human lung carcinoma cell lines A549 and H226, by inhibiting growth and inducing apoptosis. PMID:11335795

  3. Morphologic criteria and detection of apoptosis.

    PubMed

    Saraste, A

    1999-05-01

    . The specificity of the results can be substantiated by combining other methods with TUNEL, such as assessment of the pattern of DNA fragmentation or evaluation of the morphological features. Even though there is high variation in the results obtained in consecutive studies under the same circumstances, increasing evidence shows that TUNEL-positive cardiomyocytes and internucleosomal DNA fragmentation are associated with various cardiac diseases, including acute myocardial infarction and heart failure [reviewed in 5, 9]. Some morphological features of apoptosis have been observed in TUNEL-positive cardiomyocytes using light microscopy (Figure 1) or confocal microscopy [20]. Electron microscopic evidence of apoptosis has been found in the degenerating conduction system [7], in experimental heart failure [23], and in human hibernating myocardium [3]. In acutely ischemic myocardium the interpretation of the findings remains controversial, since only non-apoptotic cell morphology has been found in electron microscopy [8, 19]. One explanation might be abortion of the apoptotic program due to the lack of ATP before the morphologic features are fully evident [14]. Another explanation is the possibility that non-apoptotic cell death and apoptosis share common mechanisms in the early phases of the processes [14, 19]. The exact mechanisms of ischemic cell death remain to be clarified and the classification between apoptosis and non-apoptosis cell death to be specified. Recently, caspase activation has emerged as the central molecular event leading to apoptosis, preceding DNA degradation and the development of apoptotic morphology [22, 25]. New methods have been developed to demonstrate caspase activation [1, 13]. Inhibition of caspase may be an efficient way to prevent apoptotic cardiomyocyte death as well as to define and specifically probe the significance of apoptotic cell death in cardiac diseases. PMID:10412642

  4. 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.

  5. Transient elevations of cytosolic free calcium retard subsequent apoptosis in neutrophils in vitro.

    PubMed Central

    Whyte, M K; Hardwick, S J; Meagher, L C; Savill, J S; Haslett, C

    1993-01-01

    Elevation of cytosolic calcium ([Ca2+]i) has been reported to induce apoptosis in a number of cell types. However, in the neutrophil, which undergoes apoptosis constitutively during aging in vitro, activation by inflammatory mediators elevates [Ca2+]i and prolongs lifespan via inhibition of apoptosis. To examine this paradox, we investigated the effects of modulation of [Ca2+]i upon apoptosis of neutrophils in vitro. Calcium ionophores (A23187, ionomycin) retarded apoptosis in neutrophil populations after 20 h (P < 0.001). Conversely, intracellular Ca(2+)-chelation, using bis-(o-aminophenoxy)-N,N,N'N'-tetraacetic acid (BAPTA) acetoxymethyl ester (AM) promoted apoptosis (P < 0.02). W-7 (an inhibitor of calmodulin) also promoted apoptosis (P < 0.05). Measurements of [Ca2+]i, using fura-2, showed (a) increased apoptosis in neutrophil populations was not associated with elevated [Ca2+]i, (b) neutrophils cultured with ionophore at concentrations inhibiting apoptosis exhibited transient (< 1 h) elevations of [Ca2+]i, to levels previously reported with receptor-mediated stimuli, and (c) BAPTA was able to prevent the elevation of [Ca2+]i and the inhibition of apoptosis produced by ionophore. Modulation of apoptosis occurred without alterations in intracellular pH. Thus, in the neutrophil, unlike lymphoid cells, elevation of [Ca2+]i exerts an inhibitory effect upon apoptosis. Furthermore, these data suggest that transient elevation of [Ca2+]i elicits signaling events leading to prolonged inhibition of apoptosis. Images PMID:8392090

  6. 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

  7. Inhibition of the Inflammasome NLRP3 by Arglabin Attenuates Inflammation, Protects Pancreatic β-Cells from Apoptosis, and Prevents Type 2 Diabetes Mellitus Development in ApoE2Ki Mice on a Chronic High-Fat Diet.

    PubMed

    Abderrazak, Amna; El Hadri, Khadija; Bosc, Elodie; Blondeau, Bertrand; Slimane, Mohamed-Naceur; Büchele, Berthold; Simmet, Thomas; Couchie, Dominique; Rouis, Mustapha

    2016-06-01

    Intraperitoneal injection of arglabin (2.5 ng/g of body weight, twice daily, 13 weeks) into female human apolipoprotein E2 gene knock-in (ApoE2Ki) mice fed a high-fat Western-type diet (HFD) reduced plasma levels of glucose and insulin by ∼20.0% ± 3.5% and by 50.0% ± 2.0%, respectively, in comparison with vehicle-treated mice. Immunohistochemical analysis revealed the absence of active caspase-3 in islet sections from ApoE2Ki mice fed a HFD and treated with arglabin. In addition, arglabin reduced interleukin-1β (IL-1β) production in a concentration-dependent manner in Langerhans islets isolated from ApoE2Ki mice treated with lipopolysaccharide (LPS) and with cholesterol crystals. This inhibitory effect is specific for the inflammasome NOD-like receptor family, pyrin domain-containing 3 (NLRP3) because IL-1β production was abolished in Langerhans islets isolated from Nlrp3(-/-) mice. In the insulin-secreting INS-1 cells, arglabin inhibited, in a concentration-dependent manner, the maturation of pro-IL-1β into biologically active IL-1β probably through the inhibition of the maturation of procaspase-1 into active capsase-1. Moreover, arglabin reduced the susceptibility of INS-1 cells to apoptosis by increasing Bcl-2 levels. Similarly, autophagy activation by rapamycin decreased apoptosis susceptibility while autophagy inhibition by 3-methyladenin treatment promoted apoptosis. Arglabin further increased the expression of the autophagic markers Bcl2-interacting protein (Beclin-1) and microtubule-associated protein 1 light chain 3 II (LC3-II) in a concentration-dependent manner. Thus, arglabin reduces NLRP3-dependent inflammation as well as apoptosis in pancreatic β-cells in vivo and in the INS-1 cell line in vitro, whereas it increases autophagy in cultured INS-1 cells, indicating survival-promoting properties of the compound in these cells. Hence, arglabin may represent a new promising compound to treat inflammation and type 2 diabetes mellitus development

  8. Apoptosis in Anthracycline Cardiomyopathy

    PubMed Central

    Shi, Jianjian; Abdelwahid, Eltyeb; Wei, Lei

    2011-01-01

    Apoptosis is a tightly regulated physiologic process of programmed cell death that occurs in both normal and pathologic tissues. Numerous in vitro or in vivo studies have indicated that cardiomyocyte death through apoptosis and necrosis is a primary contributor to the progression of anthracycline-induced cardiomyopathy. There are now several pieces of evidence to suggest that activation of intrinsic and extrinsic apoptotic pathways contribute to anthracycline-induced apoptosis in the heart. Novel strategies were developed to address a wide variety of cardiotoxic mechanisms and apoptotic pathways by which anthracycline influences cardiac structure and function. Anthracycline-induced apoptosis provides a very valid representation of cardiotoxicity in the heart, an argument which has implications for the most appropriate animal models of damaged heart plus diverse pharmacological effects. In this review we describe various aspects of the current understanding of apoptotic cell death triggered by anthracycline. Differences in the sensitivity to anthracycline-induced apoptosis between young and adult hearts are also discussed. PMID:22212952

  9. 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.

  10. Ferroptosis: A missing puzzle piece in the p53 blueprint?

    PubMed Central

    Wang, Shang-Jui; Ou, Yang; Jiang, Le; Gu, Wei

    2016-01-01

    ABSTRACT Recent evidence indicates that canonical functions of p53 (i.e., apoptosis and growth arrest) are dispensable for p53-mediated tumor suppression. We have uncovered a novel function of p53 that contributes to tumor suppression through regulation of cystine metabolism, reactive oxygen species responses, and ferroptosis. The p53-mediated ferroptotic response via SLC7A11 denotes an extra layer of defense against tumorigenesis in conjunction with other p53 functions. PMID:27314071

  11. Ferroptosis: A missing puzzle piece in the p53 blueprint?

    PubMed

    Wang, Shang-Jui; Ou, Yang; Jiang, Le; Gu, Wei

    2016-05-01

    Recent evidence indicates that canonical functions of p53 (i.e., apoptosis and growth arrest) are dispensable for p53-mediated tumor suppression. We have uncovered a novel function of p53 that contributes to tumor suppression through regulation of cystine metabolism, reactive oxygen species responses, and ferroptosis. The p53-mediated ferroptotic response via SLC7A11 denotes an extra layer of defense against tumorigenesis in conjunction with other p53 functions. PMID:27314071

  12. [Sphingolipid and apoptosis].

    PubMed

    Wang, Jing; Hu, Xiao-Song; Shi, Jie-Ping

    2003-07-01

    Over the last decade, considerable progress has been made in the study of sphingolipids with the development of biological techniques. Sphingolipids play important roles in diverse physiological process, including cytoskeleton migration, angiogenesis, embryonic development and signal transduction. Except for this, the lastest evidence has suggested that sphingolipids and their metabolite (ceramide, sphingosine, sphingosine 1-phosphate) can induce apoptosis in a wide variety of tumor cell lines such as LoVo HT29, Bel7402, A549, CNE2 cells. This paper is attempted to review the recent advances of investigation into the relationship between sphingolipids and apoptosis. PMID:14628466

  13. [Apoptosis during embryo development].

    PubMed

    Jezek, Davor; Kozina, Viviana

    2009-10-01

    The development of human embryo includes two essential processes, i.e., rapid mitotic activity of cells and gradual differentiation of tissues and organs. The latter process is very often characterized by extensive migration of cells from their site of origin to the site of definitive location, inductive action of the neighboring germ layers and programmed cell death (apoptosis). This paper describes examples of proliferative and apoptotic processes during the development of human embryo. The development of trilaminar germ disk, skin, gonads, central and peripheral nerve system as well as limbs provides instructive examples of how apoptosis regulates the development and differentiation of cells. PMID:19999545

  14. The p90 ribosomal S6 kinase (RSK) inhibitor BI-D1870 prevents gamma irradiation-induced apoptosis and mediates senescence via RSK- and p53-independent accumulation of p21WAF1/CIP1

    PubMed Central

    Neise, D; Sohn, D; Stefanski, A; Goto, H; Inagaki, M; Wesselborg, S; Budach, W; Stühler, K; Jänicke, R U

    2013-01-01

    The p90 ribosomal S6 kinase (RSK) family is a group of highly conserved Ser/Thr kinases that promote cell proliferation, growth, motility and survival. As they are almost exclusively activated downstream of extracellular signal-regulated kinases 1 and 2 (ERK1/2), therapeutic intervention by RSK inhibition is less likely to produce such severe side effects as those observed following inhibition of the upstream master regulators Raf, MEK and ERK1/2. Here, we report that BI-D1870, a potent small molecule inhibitor of RSKs, induces apoptosis, although preferentially, in a p21-deficient background. On the other hand, BI-D1870 also induces a strong transcription- and p53-independent accumulation of p21 protein and protects cells from gamma irradiation (γIR)-induced apoptosis, driving them into senescence even in the absence of γIR. Although we identified p21 in in vitro kinase assays as a novel RSK substrate that specifically becomes phosphorylated by RSK1-3 at Ser116 and Ser146, RNA-interference, overexpression and co-immunoprecipitation studies as well as the use of SL0101, another specific RSK inhibitor, revealed that BI-D1870 mediates p21 accumulation via a yet unknown pathway that, besides its off-site targets polo-like kinase-1 and AuroraB, also does also not involve RSKs. Thus, this novel off-target effect of BI-D1870 should be taken into serious consideration in future studies investigating the role of RSKs in cellular signaling and tumorigenesis. PMID:24136223

  15. Apoptosis in colorectal cancer.

    PubMed

    Stoian, M; State, N; Stoica, V; Radulian, G

    2014-06-15

    Apoptosis is an inborn process that has been preserved during evolution; it allows the cells to systematically inactivate, destroy and dispose of their own components thus leading to their death. This programme can be activated by both intra and extracellular mechanisms. The intracellular components involve a genetically defined development programme while the extracellular aspects regard endogenous proteins, cytokines and hormones as well as xenobiotics, radiations, oxidative stress and hypoxia. The ability of a cell to enter apoptosis as a response to a "death" signal depends on its proliferative status, the position in the cell cycle and also on the controlled expression of those genes that have the capacity of promoting and inhibiting cell death. The fine regulation of these parameters needs to be maintained in order to ensure the physiological environment required for the induction of apoptosis. Any malfunction in any of the steps of controlled cellular death can lead to dysfunctions and, as a consequence, to different pathological conditions. The importance of apoptosis lies in its active nature and in the potential of controlling biological systems. PMID:25408720

  16. 6-Gingerol induces autophagy to protect HUVECs survival from apoptosis.

    PubMed

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

    2016-08-25

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

  17. Role of Siglec-7 in Apoptosis in Human Platelets

    PubMed Central

    Nguyen, Kim Anh; Hamzeh-Cognasse, Hind; Palle, Sabine; Anselme-Bertrand, Isabelle; Arthaud, Charles-Antoine; Chavarin, Patricia; Pozzetto, Bruno; Garraud, Olivier; Cognasse, Fabrice

    2014-01-01

    Background Platelets participate in tissue repair and innate immune responses. Sialic acid-binding immunoglobulin-like lectins (Siglecs) are well-characterized I-type lectins, which control apoptosis. Methodology/Principal Findings We characterized the expression of Siglec-7 in human platelets isolated from healthy volunteers using flow cytometry and confocal microscopy. Siglec-7 is primarily expressed on α granular membranes and colocalized with CD62P. Siglec-7 expression was increased upon platelet activation and correlated closely with CD62P expression. Cross-linking Siglec-7 with its ligand, ganglioside, resulted in platelet apoptosis without any significant effects on activation, aggregation, cell morphology by electron microscopy analysis or secretion. We show that ganglioside triggered four key pathways leading to apoptosis in human platelets: (i) mitochondrial inner transmembrane potential (ΔΨm) depolarization; (ii) elevated expression of pro-apoptotic Bax and Bak proteins with reduced expression of anti-apoptotic Bcl-2 protein; (iii) phosphatidylserine exposure and (iv), microparticle formation. Inhibition of NAPDH oxidase, PI3K, or PKC rescued platelets from apoptosis induced by Siglec-7 recruitment, suggesting that the platelet receptors P2Y1 and GPIIbIIIa are essential for ganglioside-induced platelet apoptosis. Conclusions/Significance The present work characterizes the role of Siglec-7 and platelet receptors in regulating apoptosis and death. Because some platelet pathology involves apoptosis (idiopathic thrombocytopenic purpura and possibly storage lesions), Siglec-7 might be a molecular target for therapeutic intervention/prevention. PMID:25230315

  18. Oncogene-dependent apoptosis is mediated by caspase-9

    PubMed Central

    Fearnhead, Howard O.; Rodriguez, Joe; Govek, Eve-Ellen; Guo, Wenjun; Kobayashi, Ryuji; Hannon, Greg; Lazebnik, Yuri A.

    1998-01-01

    Understanding how oncogenic transformation sensitizes cells to apoptosis may provide a strategy to kill tumor cells selectively. We previously developed a cell-free system that recapitulates oncogene dependent apoptosis as reflected by activation of caspases, the core of the apoptotic machinery. Here, we show that this activation requires a previously identified apoptosis-promoting complex consisting of caspase-9, APAF-1, and cytochrome c. As predicted by the in vitro system, preventing caspase-9 activation blocked drug-induced apoptosis in cells sensitized by E1A, an adenoviral oncogene. Oncogenes, such as E1A, appear to facilitate caspase-9 activation by several mechanisms, including the control of cytochrome c release from the mitochondria. PMID:9811857

  19. [Ice/ced-3 family gene and apoptosis].

    PubMed

    Miura, M

    1996-07-01

    Apoptosis is a process by which cells carry out their own execution by activating an orderly set of genetic and biochemical program. A genetic pathway of apoptosis has been identified in the nematode Caenorhabditis elegans. The ced-3 gene is required for all programmed cell death in C. elegans. Mammalian homolog of ced-3 has been identified as Ice family which is newly identified cysteine protease. Overexpression of Ice/ced-3 family gene can induce apoptosis in a variety of mammalian cells, and inhibitors of Ice/ced-3 family effectively prevent apoptosis induced by a variety of stimulus. Several housekeeping genes have been shown to be targets of Ice/ced-3 family gene, indicating that activation of Ice/ced-3 can induce irreversible fatal changes of cells. PMID:8741679

  20. Future perspectives and potential implications of cardiac myocyte apoptosis.

    PubMed

    Haunstetter, A; Izumo, S

    2000-02-01

    Recent advances in the understanding of the molecular mechanisms of apoptosis has gained increasing interest in the cardiovascular research community. Apoptotic myocyte loss has been detected in different cardiac disease states such as ischemic heart disease and congestive heart failure. In addition, some evidence for the molecular mechanisms in cardiac myocyte apoptosis has been evolving, although at present the implications thereof for clinical cardiac disease are not known in most of the cases. Based on these new insights, it is the intention of this article to highlight some topics in apoptosis research that might be of particular interest to define the future role and potentials of new therapeutic approaches aimed at preventing myocyte apoptosis. PMID:10728403

  1. PECAM-1, apoptosis and CD34+ precursors.

    PubMed

    Zocchi, Maria R; Poggi, A

    2004-11-01

    Apoptosis is a physiological process that controls tissue homeostasis, in combination with survival signals delivered by distinct receptors that bind hormones, growth factors or extracellular matrix components. The extrinsic pathway of apoptosis is due to the triggering of death receptors and the activation of the caspase cascade; the intrinsic pathway is due to withdrawal of growth factors and mainly related to mitochondrial metabolism. The choice between survival or apoptosis, which is the result of such different integrated environmental signals, is crucial for the maintainance of bone marrow reservoir of hematopoietic precursors (HPC). CD34+ HPC can receive multiple survival signals during homing and maturation, due to different interactions with adhesion molecules expressed on endothelial and bone marrow stromal cells, proteins of the extracellular matrix and chemokines or growth factors. Among them, the signal delivered via platelet endothelial cell adhesion molecule-1 (PECAM-1) seems to contribute to the resistance of this cell population to starvation, and it is related to the maintainance of mitochondrial metabolism. Indeed, this molecule, originally described as an adhesion receptor belonging to the immunoglobulin superfamily, capable of homophilic and heterophilic interactions, turned out to be a signalling molecule, containing an immunoreceptor tyrosine-based inhibitory motifs (ITIM) within its cytoplasmic domain. In particular, it has been shown that PECAM-1 binds to different kinases and phosphatases, including the phosphatidylinositide-3-kinase that phosphorylates Akt, which, in turn can upregulate transcription and function of antiapoptotic proteins, such as Bcl-2 and Bcl-x or A1, responsible for the rescue from mitochondrial apoptosis. The possible role of PECAM-1 engagement in the prevention of starvation-induced apoptosis of HPC precursors and in the maintainance of their survival is discussed. PMID:15512808

  2. Preventing stroke

    MedlinePlus

    Stroke - prevention; CVA - prevention; cerebral vascular accident - prevention; TIA - prevention, transient ischemic attack - prevention ... Clinical Cardiology; Council on Functional Genomics and ... Council on Hypertension. Guidelines for the primary prevention ...

  3. 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

  4. 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

  5. Apoptosis of circulating lymphocytes during pediatric cardiac surgery

    NASA Astrophysics Data System (ADS)

    Bocsi, J.; Pipek, M.; Hambsch, J.; Schneider, P.; Tárnok, A.

    2006-02-01

    There is a constant need for clinical diagnostic systems that enable to predict disease course for preventative medicine. Apoptosis, programmed cell death, is the end point of the cell's response to different induction and leads to changes in the cell morphology that can be rapidly detected by optical systems. We tested whether apoptosis of T-cells in the peripheral blood is useful as predictor and compared different preparation and analytical techniques. Surgical trauma is associated with elevated apoptosis of circulating leukocytes. Increased apoptosis leads to partial removal of immune competent cells and could therefore in part be responsible for reduced immune defence. Cardiovascular surgery with but not without cardiopulmonary bypass (CPB) induces transient immunosuppression. Its effect on T-cell apoptosis has not been shown yet. Flow-cytometric data of blood samples from 107 children (age 3-16 yr.) who underwent cardiac surgery with (78) or without (29) CPB were analysed. Apoptotic T-lymphocytes were detected based on light scatter and surface antigen (CD45/CD3) expression (ClinExpImmunol2000;120:454). Results were compared to staining with CD3 antibodies alone and in the absence of antibodies. T-cell apoptosis rate was comparable when detected with CD45/CD3 or CD3 alone, however not in the absence of CD3. Patients with but not without CPB surgery had elevated lymphocyte apoptosis. T-cell apoptosis increased from 0.47% (baseline) to 0.97% (1 day postoperatively). In CPB patients with complication 1.10% significantly higher (ANOVA p=0.01) comparing to CPB patients without complications. Quantitation of circulating apoptotic cells based on light scatter seems an interesting new parameter for diagnosis. Increased apoptosis of circulating lymphocytes and neutrophils further contributes to the immune suppressive response to surgery with CPB. (Support: MP, Deutsche Herzstiftung, Frankfurt, Germany)

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

    PubMed

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

    2015-01-01

    Castration-resistant prostate cancer (CRPC) is a major clinical challenge for which no cure is currently available primarily because of the lack of proper understanding about appropriate molecular target(s). Previously we observed that inhibition of 5-lipoxygenase (5-Lox) activity induces apoptosis in some types of prostate cancer cells, suggesting an important role of 5-Lox in the viability of prostate cancer cells. However, nothing is known about the role of 5-Lox in the survival of castration-resistant, metastatic prostate cancer cells. Thus, we tested the effects of MK591, a second-generation, specific inhibitor of 5-Lox activity, on the viability and metastatic characteristics of CRPC cells. We observed that MK591 effectively kills the bone-invading C4-2B human prostate cancer cells (which bear characteristics of CRPC), but does not affect normal, non-cancer fibroblasts (which do not express 5-Lox) in the same experimental conditions. We also observed that MK591 dramatically inhibits the in vitro invasion and soft-agar colony formation of C4-2B cells. Interestingly, we found that treatment with MK591 dramatically down-regulates the expression of c-Myc and its targets at sub-lethal doses. In light of frequent over-activation of c-Myc in a spectrum of aggressive cancers (including CRPC), and the challenges associated with inhibition of c-Myc (because of its non-enzymatic nature), our novel findings of selective killing, and blockade of invasive and soft-agar colony-forming abilities of the castration-resistant, bone-metastatic C4-2B prostate cancer cells by MK591, open up a new avenue to attack CRPC cells for better management of advanced prostate cancer while sparing normal, non-cancer body cells. PMID:25875826

  7. Genome surveillance in pluripotent stem cells: Low apoptosis threshold and efficient antioxidant defense

    PubMed Central

    Dannenmann, Benjamin; Lehle, Simon; Essmann, Frank; Schulze-Osthoff, Klaus

    2016-01-01

    ABSTRACT Pluripotent stem cells must be endowed with efficient genome surveillance. Here we describe the multiple mechanisms that ensure their genome integrity, including high susceptibility to apoptosis and efficient prevention of DNA lesions. In induced pluripotent stem cells, apoptosis hypersensitivity is mediated by increased expression of proapoptotic BCL-2 protein, whereas DNA damage is prevented by the upregulation of several antioxidant enzymes. Antioxidants might be therefore employed for safer stem cell therapies. PMID:27308586

  8. Role of Calpain in Apoptosis

    PubMed Central

    Momeni, Hamid Reza

    2011-01-01

    Apoptosis, a form of programmed cell death that occurs under physiological as well as pathological conditions, is characterized by morphological and biochemical features. While the importance of caspases in apoptosis is established, several noncaspase proteases (Ca2+-dependent proteases) such as calpain may play a role in the execution of apoptosis. The calpain family consists of two major isoforms, calpain I and calpain II which require µM and mM Ca2+ concentrations to initiate their activity. An increase in intracellular Ca2+ level is thought to trigger a cascade of biochemical processes including calpain activation. Once activated, calpains degrade membrane, cytoplasmic and nuclear substrates, leading to the breakdown of cellular architecture and finally apoptosis. The activation of calpain has been implicated in neuronal apoptosis following spinal cord injuries and neurodegenerative diseases. This review focuses on calpain with an emphasis on its key role in the proteolysis of cellular protein substrates following apoptosis. PMID:23507938

  9. Pathophysiological Significance of Hepatic Apoptosis

    PubMed Central

    Wang, Kewei; Lin, Bingliang

    2013-01-01

    Apoptosis is a classical pathological feature in liver diseases caused by various etiological factors such as drugs, viruses, alcohol, and cholestasis. Hepatic apoptosis and its deleterious effects exacerbate liver function as well as involvement in fibrosis/cirrhosis and carcinogenesis. An imbalance between apoptotic and antiapoptotic capabilities is a prominent characteristic of liver injury. The regulation of apoptosis and antiapoptosis can be a pivotal step in the treatment of liver diseases. PMID:27335822

  10. Characterization of FKGK18 as inhibitor of group VIA Ca2+-independent phospholipase A2 (iPLA2β): candidate drug for preventing beta-cell apoptosis and diabetes.

    PubMed

    Ali, Tomader; Kokotos, George; Magrioti, Victoria; Bone, Robert N; Mobley, James A; Hancock, William; Ramanadham, Sasanka

    2013-01-01

    Ongoing studies suggest an important role for iPLA2β in a multitude of biological processes and it has been implicated in neurodegenerative, skeletal and vascular smooth muscle disorders, bone formation, and cardiac arrhythmias. Thus, identifying an iPLA2βinhibitor that can be reliably and safely used in vivo is warranted. Currently, the mechanism-based inhibitor bromoenol lactone (BEL) is the most widely used to discern the role of iPLA2β in biological processes. While BEL is recognized as a more potent inhibitor of iPLA2 than of cPLA2 or sPLA2, leading to its designation as a "specific" inhibitor of iPLA2, it has been shown to also inhibit non-PLA2 enzymes. A potential complication of its use is that while the S and R enantiomers of BEL exhibit preference for cytosol-associated iPLA2β and membrane-associated iPLA2γ, respectively, the selectivity is only 10-fold for both. In addition, BEL is unstable in solution, promotes irreversible inhibition, and may be cytotoxic, making BEL not amenable for in vivo use. Recently, a fluoroketone (FK)-based compound (FKGK18) was described as a potent inhibitor of iPLA2β. Here we characterized its inhibitory profile in beta-cells and find that FKGK18: (a) inhibits iPLA2β with a greater potency (100-fold) than iPLA2γ, (b) inhibition of iPLA2β is reversible, (c) is an ineffective inhibitor of α-chymotrypsin, and (d) inhibits previously described outcomes of iPLA2β activation including (i) glucose-stimulated insulin secretion, (ii) arachidonic acid hydrolysis; as reflected by PGE2 release from human islets, (iii) ER stress-induced neutral sphingomyelinase 2 expression, and (iv) ER stress-induced beta-cell apoptosis. These findings suggest that FKGK18 is similar to BEL in its ability to inhibit iPLA2β. Because, in contrast to BEL, it is reversible and not a non-specific inhibitor of proteases, it is suggested that FKGK18 is more ideal for ex vivo and in vivo assessments of iPLA2β role in biological functions. PMID

  11. 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

  12. JNK Signaling in Apoptosis

    PubMed Central

    Dhanasekaran, Danny N.; Reddy, E. Premkumar

    2011-01-01

    Jun N-terminal kinases or JNKs play a critical role in death receptor-initiated extrinsic as well as mitochondrial intrinsic apoptotic pathways. JNKs activate apoptotic signaling by the upregulation pro-apoptotic genes via the transactivation of specific transcription factors or by directly modulating the activities of mitochondrial pro- and anti-apoptotic proteins through distinct phosphorylation events. This review analyzes our present understanding of the role of JNK in apoptotic signaling and the various mechanisms by which JNK promotes apoptosis PMID:18931691

  13. 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.

  14. Biomarkers of apoptosis

    PubMed Central

    Ward, T H; Cummings, J; Dean, E; Greystoke, A; Hou, J M; Backen, A; Ranson, M; Dive, C

    2008-01-01

    Within the era of molecularly targeted anticancer agents, it has become increasingly important to provide proof of mechanism as early on as possible in the drug development cycle, especially in the clinic. Selective activation of apoptosis is often cited as one of the major goals of cancer chemotherapy. Thus, the present minireview focuses on a discussion of the pros and cons of a variety of methodological approaches to detect different components of the apoptotic cascade as potential biomarkers of programmed cell death. The bulk of the discussion centres on serological assays utilising the technique of ELISA, since here there is an obvious advantage of sampling multiple time points. Potential biomarkers of apoptosis including circulating tumour cells, cytokeratins and DNA nucleosomes are discussed at length. However, accepting that a single biomarker may not have the power to predict proof of concept and patient outcome, it is clear that in the future more emphasis will be placed on technologies that can analyse panels of biomarkers in small volumes of samples. To this end the increased throughput afforded by multiplex ELISA technologies is discussed. PMID:19238626

  15. Apaf1 inhibition promotes cell recovery from apoptosis.

    PubMed

    Gortat, Anna; Sancho, Mónica; Mondragón, Laura; Messeguer, Àngel; Pérez-Payá, Enrique; Orzáez, Mar

    2015-11-01

    The protein apoptotic protease activating factor 1 (Apaf1) is the central component of the apoptosome, a multiprotein complex that activates procaspase-9 after cytochrome c release from the mitochondria in the intrinsic pathway of apoptosis. We have developed a vital method that allows fluorescence-activated cell sorting of cells at different stages of the apoptotic pathway and demonstrated that upon pharmacological inhibition of Apaf1, cells recover from doxorubicin- or hypoxia-induced early apoptosis to normal healthy cell. Inhibiting Apaf1 not only prevents procaspase-9 activation but delays massive mitochondrial damage allowing cell recovery. PMID:26361785

  16. Apoptosis and the Airway Epithelium

    PubMed Central

    White, Steven R.

    2011-01-01

    The airway epithelium functions as a barrier and front line of host defense in the lung. Apoptosis or programmed cell death can be elicited in the epithelium as a response to viral infection, exposure to allergen or to environmental toxins, or to drugs. While apoptosis can be induced via activation of death receptors on the cell surface or by disruption of mitochondrial polarity, epithelial cells compared to inflammatory cells are more resistant to apoptotic stimuli. This paper focuses on the response of airway epithelium to apoptosis in the normal state, apoptosis as a potential regulator of the number and types of epithelial cells in the airway, and the contribution of epithelial cell apoptosis in important airways diseases. PMID:22203854

  17. RIPK1 maintains epithelial homeostasis by inhibiting apoptosis and necroptosis.

    PubMed

    Dannappel, Marius; Vlantis, Katerina; Kumari, Snehlata; Polykratis, Apostolos; Kim, Chun; Wachsmuth, Laurens; Eftychi, Christina; Lin, Juan; Corona, Teresa; Hermance, Nicole; Zelic, Matija; Kirsch, Petra; Basic, Marijana; Bleich, Andre; Kelliher, Michelle; Pasparakis, Manolis

    2014-09-01

    Necroptosis has emerged as an important pathway of programmed cell death in embryonic development, tissue homeostasis, immunity and inflammation. RIPK1 is implicated in inflammatory and cell death signalling and its kinase activity is believed to drive RIPK3-mediated necroptosis. Here we show that kinase-independent scaffolding RIPK1 functions regulate homeostasis and prevent inflammation in barrier tissues by inhibiting epithelial cell apoptosis and necroptosis. Intestinal epithelial cell (IEC)-specific RIPK1 knockout caused IEC apoptosis, villus atrophy, loss of goblet and Paneth cells and premature death in mice. This pathology developed independently of the microbiota and of MyD88 signalling but was partly rescued by TNFR1 (also known as TNFRSF1A) deficiency. Epithelial FADD ablation inhibited IEC apoptosis and prevented the premature death of mice with IEC-specific RIPK1 knockout. However, mice lacking both RIPK1 and FADD in IECs displayed RIPK3-dependent IEC necroptosis, Paneth cell loss and focal erosive inflammatory lesions in the colon. Moreover, a RIPK1 kinase inactive knock-in delayed but did not prevent inflammation caused by FADD deficiency in IECs or keratinocytes, showing that RIPK3-dependent necroptosis of FADD-deficient epithelial cells only partly requires RIPK1 kinase activity. Epidermis-specific RIPK1 knockout triggered keratinocyte apoptosis and necroptosis and caused severe skin inflammation that was prevented by RIPK3 but not FADD deficiency. These findings revealed that RIPK1 inhibits RIPK3-mediated necroptosis in keratinocytes in vivo and identified necroptosis as a more potent trigger of inflammation compared with apoptosis. Therefore, RIPK1 is a master regulator of epithelial cell survival, homeostasis and inflammation in the intestine and the skin. PMID:25132550

  18. 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.

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

    PubMed Central

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

    2016-01-01

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

  20. Zinc protects against ultraviolet A1-induced DNA damage and apoptosis in cultured human fibroblasts.

    PubMed

    Leccia, M T; Richard, M J; Favier, A; Béani, J C

    1999-09-01

    Ultraviolet A1 (UVA1) radiation generates reactive oxygen species and the oxidative stress is known as a mediator of DNA damage and of apoptosis. We exposed cultured human cutaneous fibroblasts to UVA1 radiation (wavelengths in the 340-450-nm range with emission peak at 365 nm) and, using the alkaline unwinding method, we showed an immediate significant increase of DNA strand breaks in exposed cells. Apoptosis was determined by detecting cytoplasmic nucleosomes (enzyme-linked immunosorbent assay method) at different time points in fibroblasts exposed to different irradiation doses. In our conditions, UVA1 radiation induced an early (8 h) and a delayed (18 h) apoptosis. Delayed apoptosis increased in a UVA dose-dependent manner. Zinc is an important metal for DNA protection and has been shown to have inhibitory effects on apoptosis. The addition of zinc (6.5 mg/L) as zinc chloride to the culture medium significantly decreased immediate DNA strand breaks in human skin fibroblasts. Moreover, zinc chloride significantly decreased UVA1-induced early and delayed apoptosis. Thus, these data show for the first time in normal cutaneous cultured cells that UVA1 radiation induces apoptosis. This apoptosis is biphasic and appears higher 18 h after the stress. Zinc supplementation can prevent both immediate DNA strand breakage and early and delayed apoptosis, suggesting that this metal could be of interest for skin cell protection against UVA1 irradiation. PMID:10468155

  1. [Apoptosis and its biomedical significance].

    PubMed

    Ortega-Camarillo, C; Díaz-Flores, M; Avalos-Rodríguez, A; Vergara-Onofre, M; Rosales-Torres, A M

    2001-01-01

    Cell death can occur through apoptotic or necrotic death pathways. Membrane disruption leads to inflammation, a typical feature of necrosis. Apoptosis constitutes a genetically controlled physiologic process of cell removal. It is characterized by cell shrinkage, chromatin condensation, and DNA cleavage. Apoptotic cells are rapidly recognized and engulfed by phagocytes thus inhibiting an inflammatory response following necrosis. Apoptosis has been proposed as a basic event to protect tissue homeostasis. This paper analyzes the genetic, biochemical, and morphologic characteristics related to apoptosis, as well as its relationship to certain illnesses. PMID:11766462

  2. Csk regulates angiotensin II-induced podocyte apoptosis.

    PubMed

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

    2016-07-01

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

  3. Induction of apoptosis by the transcription factor c-Jun.

    PubMed Central

    Bossy-Wetzel, E; Bakiri, L; Yaniv, M

    1997-01-01

    c-Jun, a signal-transducing transcription factor of the AP-1 family, normally implicated in cell cycle progression, differentiation and cell transformation, recently has also been linked to apoptosis. To explore further the functional roles of c-Jun, a conditional allele was generated by fusion of c-Jun with the hormone-binding domain of the human estrogen receptor (ER). Here we demonstrate that increased c-Jun activity is sufficient to trigger apoptotic cell death in NIH 3T3 fibroblasts. c-Jun-induced apoptosis is evident at high serum levels, but is enhanced further in factor-deprived fibroblasts. Furthermore, apoptosis by c-Jun is not accompanied by an increase in DNA synthesis. Constitutive overexpression of the apoptosis inhibitor protein Bcl-2 delays the c-Jun-mediated cell death. The regions of c-Jun necessary for apoptosis induction include the amino-terminal transactivation and the carboxy-terminal leucine zipper domain, suggesting that c-Jun may activate cell death by acting as a transcriptional regulator. We further show that alpha-fodrin, a substrate of the interleukin 1beta-converting enzyme (ICE) and CED-3 family of cysteine proteases, becomes proteolytically cleaved in cells undergoing cell death by increased c-Jun activity. Moreover, cell-permeable irreversible peptide inhibitors of the ICE/CED-3 family of cysteine proteases prevented the cell death. PMID:9130714

  4. Mitochondria and apoptosis: emerging concepts

    PubMed Central

    Li, Mark Xiang

    2015-01-01

    As mitochondria are the powerhouses of the cell, their damage during the cell suicide process of apoptosis is essentially responsible for cellular demise in most cells. A key family of proteins, the B-cell lymphoma-2 (BCL-2) family, determines the integrity of mitochondria in the face of apoptotic insult. A comprehensive understanding of the molecular details of how apoptosis is initiated and how it culminates is essential if apoptosis is to fulfil its undoubted potential as a therapeutic target to treat diseases ranging from cancer to neurodegenerative conditions. Recent advances have provided significant insight into the control of this fundamental process while prompting a re-evaluation of what was considered dogma in the field. Emerging evidence also points to a potential overarching control network that governs not only apoptosis but other fundamental mitochondrial processes, including mitochondrial fission/fusion and quality control. PMID:26097715

  5. Beyond Apoptosis in Lupus

    PubMed Central

    Colonna, Lucrezia; Lood, Christian; Elkon, Keith B.

    2014-01-01

    Purpose of review Systemic lupus erythematosus (SLE) is characterized by autoantibodies directed against nuclear autoantigens normally concealed from immune recognition in healthy individuals. Here we summarize recently identified mechanisms of abnormal cell death leading to exposure and aberrant processing of nucleoprotein self antigens, and discuss their role in the SLE pathogenesis. Recent findings During the past few years, the unveiling of several new forms of cell death has expanded our understanding beyond the simple view of “apoptotic” versus “necrotic” cell death. SLE patients show abnormalities in cell death at several levels, including increased rates of apoptosis, necrosis, and autophagy, as well as reduced clearance of dying cells. These abnormalities lead to an increased autoantigen burden and also antigen modifications, such as nucleic acid oxidation that increase the inflammatory properties of self antigens. Recent investigations have highlighted the role of opsonins in determining the immunogenic versus tolerogenic characteristics of self antigens. Summary Dysregulation of different forms of programmed cell death contributes to increased exposure, availability, and immunogenic characteristic of intracellular self antigens, which all participate in development of lupus autoimmunity. As our understanding of abnormalities of cell death in SLE advances, potential therapeutic opportunities await human implementation. PMID:25036095

  6. Cytoskeleton and apoptosis.

    PubMed

    Ndozangue-Touriguine, Olivia; Hamelin, Jocelyne; Bréard, Jacqueline

    2008-07-01

    Apoptosis is a genetically programmed and physiological mode of cell death that leads to the removal of unwanted or abnormal cells. Cysteine-proteases called caspases are responsible for the apoptotic execution phase which is characterized by specific biochemical events as well as morphological changes. These changes, which lead to the orderly dismantling of the apoptotic cell, include cell contraction, dynamic membrane blebbing, chromatin condensation, nuclear disintegration, cell fragmentation followed by phagocytosis of the dying cell. They involve major modifications of the cytoskeleton which are largely mediated by cleavage of several of its components by caspases. For example, dynamic membrane blebbing is due to the increased contractility of the acto-myosin system following myosin light chain (MLC) phosphorylation. MLC phosphorylation is a consequence of the cleavage of a Rho GTPase effector, the kinase ROCK I, by caspase-3. This cleavage induces a constitutive kinase activity by removal of an inhibitory domain. Chromatin condensation is facilitated by the processing of lamins by caspases. Collapse of the cytokeratin network is mediated by cleavage of keratin 18. On another hand, the actin cytoskeleton rearrangement needed in the phagocyte for engulfment of the dying cell is due to the activation of the small GTPase Rac, a GTPase of the Rho family that induces actin polymerisation and formation of lamellipodia. In addition to mediating the morphological modifications of the apoptotic cell, several proteins of the cytoskeleton such as actin and keratins are also involved in the regulation of apoptotic signaling. PMID:18462707

  7. [Mechanisms of signaling associated with reactive nitrogen and oxygen in apoptosis].

    PubMed

    Piłat, Justyna; Ługowski, Mateusz; Saczko, Jolanta; Choromańska, Anna; Chwiłkowska, Agnieszka; Banaś, Teresa; Kulbacka, Julita

    2016-05-26

    The knowledge of apoptotic mechanisms is essential in many biologic aspects related to both normal and neoplastic cells. Cell death by apoptosis is a very desirable way to eliminate unwanted cells: prevents release of the cellular content, which, in contrast to necrosis, provides no activation of inflammatory reactions. Apoptosis is a multistep process in where an extremely important role is played by caspases. Functions of caspases and their modifications are fundamental to understanding the signaling pathways responsible for regulation of apoptosis. These enzymes belong to a family of cysteine proteases that have the potential to destroy the enzymatic and structural proteins, and in the final stages of apoptosis, to lead to the disintegration of the cell. Apoptosis can be modulated by certain signaling pathway. PMID:27234855

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

    PubMed

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

    2015-10-01

    The aim of this study was to examine the in vitro effect of zinc on the apoptosis of human melanoma cells, by studying the zinc-dependent modulation of intracellular levels of reactive oxygen species (ROS) and of p53 and FAS ligand proteins. We showed that zinc concentrations ranging from 33.7 μM to 75 μM Zn(2+) induced apoptosis in the human melanoma cell line WM 266-4. This apoptosis was associated with an increased production of intracellular ROS, and of p53 and FAS ligand protein. Treatment of tumor cells with the antioxidant N-acetylcysteine was able to prevent Zn(2+)-induced apoptosis, as well as the increase of p53 and FAS ligand protein induced by zinc. Zinc induces apoptosis in melanoma cells by increasing ROS and this effect may be mediated by the ROS-dependent induction of p53 and FAS/FAS ligand. PMID:26408691

  9. Cancer-selective apoptosis by tumor suppressor par-4.

    PubMed

    Hebbar, Nikhil; Shrestha-Bhattarai, Tripti; Rangnekar, Vivek M

    2014-01-01

    Tumor suppressor genes play an important role in preventing neoplastic transformation and maintaining normal tissue homeostasis. Par-4 is one such tumor suppressor which is unique in its ability to selectively induce apoptosis in cancer cells while leaving the normal cells unaffected. The cancer cell specific activity of Par-4 is elicited through intracellular as well as extracellular mechanisms. Intracellularly Par-4 acts through the inhibition of pro-survival pathways and activation of Fas mediated apoptosis whereas extracellular (secreted Par-4) acts by binding to cell surface GRP78 leading to activation of the extrinsic apoptotic pathway. Many studies have highlighted the importance of Par-4 not only in preventing cancer development/recurrence but also as a promising anticancer therapeutic agent. PMID:25001535

  10. Herpes simplex virus 2 modulates apoptosis and stimulates NF-{kappa}B nuclear translocation during infection in human epithelial HEp-2 cells

    SciTech Connect

    Yedowitz, Jamie C.; Blaho, John A. . E-mail: john.blaho@mssm.edu

    2005-11-25

    Virus-mediated apoptosis is well documented in various systems, including herpes simplex virus 1 (HSV-1). HSV-2 is closely related to HSV-1 but its apoptotic potential during infection has not been extensively scrutinized. We report that (i) HEp-2 cells infected with HSV-2(G) triggered apoptosis, assessed by apoptotic cellular morphologies, oligosomal DNA laddering, chromatin condensation, and death factor processing when a translational inhibitor (CHX) was added at 3 hpi. Thus, HSV-2 induced apoptosis but was unable to prevent the process from killing cells. (ii) Results from a time course of CHX addition experiment indicated that infected cell protein produced between 3 and 5 hpi, termed the apoptosis prevention window, are required for blocking virus-induced apoptosis. This corresponds to the same prevention time frame as reported for HSV-1. (iii) Importantly, CHX addition prior to 3 hpi led to less apoptosis than that at 3 hpi. This suggests that proteins produced immediately upon infection are needed for efficient apoptosis induction by HSV-2. This finding is different from that observed previously with HSV-1. (iv) Infected cell factors produced during the HSV-2(G) prevention window inhibited apoptosis induced by external TNF{alpha} plus cycloheximide treatment. (v) NF-{kappa}B translocated to nuclei and its presence in nuclei correlated with apoptosis prevention during HSV-2(G) infection. (vi) Finally, clinical HSV-2 isolates induced and prevented apoptosis in HEp-2 cells in a manner similar to that of laboratory strains. Thus, while laboratory and clinical HSV-2 strains are capable of modulating apoptosis in human HEp-2 cells, the mechanism of HSV-2 induction of apoptosis differs from that of HSV-1.

  11. The relevance of the vitamin D endocrine system (VDES) for tumorigenesis, prevention, and treatment of non-melanoma skin cancer (NMSC)

    PubMed Central

    Reichrath, Jörg; Reichrath, Sandra

    2013-01-01

    Solar UV (UV)-B-radiation exerts both beneficial and adverse effects on human health. On the one hand, it is the most important environmental risk factor for the development of non-melanoma skin cancer [NMSC; most importantly basal (BCC) and squamous (SCC) cell carcinomas], that represent the most common malignancies in Caucasian populations. On the other hand, the human body’s requirements of vitamin D are mainly achieved by UV-B-induced cutaneous photosynthesis. This dilemma represents a serious problem in many populations, for an association of vitamin D-deficiency and multiple independent diseases including various types of cancer has been convincingly demonstrated. In line with these findings, epidemiologic and laboratory investigations now indicate that vitamin D and its metabolites have a risk reducing effect for NMSC. Potential mechanisms of action include inhibition of the hedgehog signaling pathway (BCC) and modulation of p53-mediated DNA damage response (SCC). As a consequence of these new findings it can be concluded that UV-B-radiation exerts both beneficial and adverse effects on risk and prognosis of NMSC. It can be assumed that many independent factors, including frequency and dose of UV-B exposure, skin area exposed, and individual factors (such as skin type and genetic determinants of the skin`s vitamin D status and of signaling pathways that are involved in the tumorigenesis of NMSC) determine whether UV-B exposure promotes or inhibits tumorigenesis of NMSC. Moreover, these findings may help to explain many of the differential effects of UV-B radiation on risk of NMSC, including variation in the dose-dependent risk for development of SCC in situ (actinic keratosis, AK), invasive SCC, and BCC. In this review, we analyze the relevance of the vitamin D endocrine system (VDES) for tumorigenesis, prevention, and treatment of NMSC and give an overview of present concepts and future perspectives. PMID:24494041

  12. Morphological and molecular characterization of adult cardiomyocyte apoptosis during hypoxia and reoxygenation.

    PubMed

    Kang, P M; Haunstetter, A; Aoki, H; Usheva, A; Izumo, S

    2000-07-21

    Apoptosis has been implicated in ischemic heart disease, but its mechanism in cardiomyocytes has not been elucidated. In this study, we investigate the effects of hypoxia and reoxygenation in adult cardiomyocytes and the molecular mechanism involved in cardiomyocyte apoptosis. Morphologically, reoxygenation induced rounding up of the cells, appearance of membrane blebs that were filled with marginated mitochondria, and ultrastructural findings characteristic of apoptosis. Reoxygenation (18 hours of reoxygenation after 6 hours of hypoxia) and prolonged hypoxia (24 hours of hypoxia) resulted in a 59% and 51% decrease in cellular viability, respectively. During reoxygenation, cell death occurred predominantly via apoptosis associated with appearance of cytosolic cytochrome c and activation of caspase-3 and -9. However, nonapoptotic cell death predominated during prolonged hypoxia. Both caspase inhibition and Bcl-2 overexpression during reoxygenation significantly improved cellular viability through inhibition of apoptosis but had minimal effect on hypoxia-induced cell death. Bcl-2 overexpression blocked reoxygenation-induced cytochrome c release and activation of caspase -3 and -9, but caspase inhibition alone did not block cytochrome c release. These results suggest that apoptosis predominates in cardiomyocytes after reoxygenation through a mitochondrion-dependent apoptotic pathway, and Bcl-2 prevents reoxygenation-induced apoptosis by inhibiting cytochrome c release from the mitochondria and prevents activation of caspase-3 and -9. PMID:10903995

  13. Cyclin-dependent kinase 2 protects podocytes from apoptosis

    PubMed Central

    Saurus, Pauliina; Kuusela, Sara; Dumont, Vincent; Lehtonen, Eero; Fogarty, Christopher L.; Lassenius, Mariann I.; Forsblom, Carol; Lehto, Markku; Saleem, Moin A.; Groop, Per-Henrik; Lehtonen, Sanna

    2016-01-01

    Loss of podocytes is an early feature of diabetic nephropathy (DN) and predicts its progression. We found that treatment of podocytes with sera from normoalbuminuric type 1 diabetes patients with high lipopolysaccharide (LPS) activity, known to predict progression of DN, downregulated CDK2 (cyclin-dependent kinase 2). LPS-treatment of mice also reduced CDK2 expression. LPS-induced downregulation of CDK2 was prevented in vitro and in vivo by inhibiting the Toll-like receptor (TLR) pathway using immunomodulatory agent GIT27. We also observed that CDK2 is downregulated in the glomeruli of obese Zucker rats before the onset of proteinuria. Knockdown of CDK2, or inhibiting its activity with roscovitine in podocytes increased apoptosis. CDK2 knockdown also reduced expression of PDK1, an activator of the cell survival kinase Akt, and reduced Akt phosphorylation. This suggests that CDK2 regulates the activity of the cell survival pathway via PDK1. Furthermore, PDK1 knockdown reduced the expression of CDK2 suggesting a regulatory loop between CDK2 and PDK1. Collectively, our data show that CDK2 protects podocytes from apoptosis and that reduced expression of CDK2 associates with the development of DN. Preventing downregulation of CDK2 by blocking the TLR pathway with GIT27 may provide a means to prevent podocyte apoptosis and progression of DN. PMID:26876672

  14. Flavones induce neutrophil apoptosis by down-regulation of Mcl-1 via a proteasomal-dependent pathway

    PubMed Central

    Lucas, Christopher D.; Allen, Keith C.; Dorward, David A.; Hoodless, Laura J.; Melrose, Lauren A.; Marwick, John A.; Tucker, Carl S.; Haslett, Christopher; Duffin, Rodger; Rossi, Adriano G.

    2013-01-01

    Neutrophil apoptosis and subsequent nonphlogistic clearance by surrounding phagocytes are key to the successful resolution of neutrophilic inflammation, with dysregulated apoptosis reported in multiple human inflammatory diseases. Enhancing neutrophil apoptosis has proresolution and anti-inflammatory effects in preclinical models of inflammation. Here we investigate the ability of the flavones apigenin, luteolin, and wogonin to induce neutrophil apoptosis in vitro and resolve neutrophilic inflammation in vivo. Human neutrophil apoptosis was assessed morphologically and by flow cytometry following incubation with apigenin, luteolin, and wogonin. All three flavones induced time- and concentration-dependent neutrophil apoptosis (apigenin, EC50=12.2 μM; luteolin, EC50=14.6 μM; and wogonin, EC50=28.9 μM). Induction of apoptosis was caspase dependent, as it was blocked by the broad-spectrum caspase inhibitor Q-VD-OPh and was associated with both caspase-3 and caspase-9 activation. Flavone-induced apoptosis was preceded by down-regulation of the prosurvival protein Mcl-1, with proteasomal inhibition preventing flavone-induced Mcl-1 down-regulation and apoptosis. The flavones abrogated the survival effects of mediators that prolong neutrophil life span, including lipoteichoic acid, peptidoglycan, dexamethasone, and granulocyte-macrophage colony stimulating factor, by driving apoptosis. Furthermore, wogonin enhanced resolution of established neutrophilic inflammation in a zebrafish model of sterile tissue injury. Wogonin-induced resolution was dependent on apoptosis in vivo as it was blocked by caspase inhibition. Our data show that the flavones induce neutrophil apoptosis and have potential as neutrophil apoptosis-inducing anti-inflammatory, proresolution agents.—Lucas, C. D., Allen, K. C., Dorward, D. A., Hoodless, L. J., Melrose, L. A., Marwick, J. A., Tucker, C. S., Haslett, C., Duffin, R., Rossi, A. G. Flavones induce neutrophil apoptosis by down-regulation of Mcl

  15. Statins induce apoptosis in rat and human myotube cultures by inhibiting protein geranylgeranylation but not ubiquinone.

    PubMed

    Johnson, Timothy E; Zhang, Xiaohua; Bleicher, Kimberly B; Dysart, Gary; Loughlin, Amy F; Schaefer, William H; Umbenhauer, Diane R

    2004-11-01

    Statins are widely used to treat lipid disorders. These drugs are safe and well tolerated; however, in <1% of patients, myopathy and/or rhabdomyolysis can develop. To better understand the mechanism of statin-induced myopathy, we examined the ability of structurally distinct statins to induce apoptosis in an optimized rat myotube model. Compound A (a lactone) and Cerivastatin (an open acid) induced apoptosis, as measured by TUNEL and active caspase 3 staining, in a concentration- and time-dependent manner. In contrast, an epimer of Compound A (Compound B) exhibited a much weaker apoptotic response. Statin-induced apoptosis was completely prevented by mevalonate or geranylgeraniol, but not by farnesol. Zaragozic acid A, a squalene synthase inhibitor, caused no apoptosis on its own and had no effect on Compound-A-induced myotoxicity, suggesting the apoptosis was not a result of cholesterol synthesis inhibition. The geranylgeranyl transferase inhibitors GGTI-2133 and GGTI-2147 caused apoptosis in myotubes; the farnesyl transferase inhibitor FTI-277 exhibited a much weaker effect. In addition, the prenylation of rap1a, a geranylgeranylated protein, was inhibited by Compound A in myotubes at concentrations that induced apoptosis. A similar statin-induced apoptosis profile was seen in human myotube cultures but primary rat hepatocytes were about 200-fold more resistant to statin-induced apoptosis. Although the statin-induced hepatotoxicity could be attenuated with mevalonate, no effect was found with either geranylgeraniol or farnesol. In studies assessing ubiquinone levels after statin treatment in rat and human myotubes, there was no correlation between ubiquinone levels and apoptosis. Taken together, these observations suggest that statins cause apoptosis in myotube cultures in part by inhibiting the geranylgeranylation of proteins, but not by suppressing ubiquinone concentration. Furthermore, the data from primary hepatocytes suggests a cell-type differential

  16. Selenium Compounds, Apoptosis and Other Types of Cell Death: An Overview for Cancer Therapy

    PubMed Central

    Sanmartín, Carmen; Plano, Daniel; Sharma, Arun K.; Palop, Juan Antonio

    2012-01-01

    Selenium (Se) is an essential trace element involved in different physiological functions of the human body and plays a role in cancer prevention and treatment. Induction of apoptosis is considered an important cellular event that can account for the cancer preventive effects of Se. The mechanisms of Se-induced apoptosis are associated with the chemical forms of Se and their metabolism as well as the type of cancer studied. So, some selenocompounds, such as SeO2 involve the activation of caspase-3 while sodium selenite induces apoptosis in the absence of the activation of caspases. Modulation of mitochondrial functions has been reported to play a key role in the regulation of apoptosis and also to be one of the targets of Se compounds. Other mechanisms for apoptosis induction are the modulation of glutathione and reactive oxygen species levels, which may function as intracellular messengers to regulate signaling pathways, or the regulation of kinase, among others. Emerging evidence indicates the overlaps between the apoptosis and other types of cell death such as autophagy. In this review we report different processes of cell death induced by Se compounds in cancer treatment and prevention. PMID:22949823

  17. Calcium/calmodulin-dependent protein kinase II links ER stress with Fas and mitochondrial apoptosis pathways

    PubMed Central

    Timmins, Jenelle M.; Ozcan, Lale; Seimon, Tracie A.; Li, Gang; Malagelada, Cristina; Backs, Johannes; Backs, Thea; Bassel-Duby, Rhonda; Olson, Eric N.; Anderson, Mark E.; Tabas, Ira

    2009-01-01

    ER stress–induced apoptosis is implicated in various pathological conditions, but the mechanisms linking ER stress–mediated signaling to downstream apoptotic pathways remain unclear. Using human and mouse cell culture and in vivo mouse models of ER stress–induced apoptosis, we have shown that cytosolic calcium resulting from ER stress induces expression of the Fas death receptor through a pathway involving calcium/calmodulin-dependent protein kinase IIγ (CaMKIIγ) and JNK. Remarkably, CaMKIIγ was also responsible for processes involved in mitochondrial-dependent apoptosis, including release of mitochondrial cytochrome c and loss of mitochondrial membrane potential. CaMKII-dependent apoptosis was also observed in a number of cultured human and mouse cells relevant to ER stress–induced pathology, including cultured macrophages, endothelial cells, and neuronal cells subjected to proapoptotic ER stress. Moreover, WT mice subjected to systemic ER stress showed evidence of macrophage mitochondrial dysfunction and apoptosis, renal epithelial cell apoptosis, and renal dysfunction, and these effects were markedly reduced in CaMKIIγ-deficient mice. These data support an integrated model in which CaMKII serves as a unifying link between ER stress and the Fas and mitochondrial apoptotic pathways. Our study also revealed what we believe to be a novel proapoptotic function for CaMKII, namely, promotion of mitochondrial calcium uptake. These findings raise the possibility that CaMKII inhibitors could be useful in preventing apoptosis in pathological settings involving ER stress–induced apoptosis. PMID:19741297

  18. Effects of short-chain acyl-CoA dehydrogenase on cardiomyocyte apoptosis.

    PubMed

    Zeng, Zhenhua; Huang, Qiuju; Shu, Zhaohui; Liu, Peiqing; Chen, Shaorui; Pan, Xuediao; Zang, Linquan; Zhou, Sigui

    2016-07-01

    Short-chain acyl-CoA dehydrogenase (SCAD), a key enzyme of fatty acid β-oxidation, plays an important role in cardiac hypertrophy. However, its effect on the cardiomyocyte apoptosis remains unknown. We aimed to determine the role of SCAD in tert-butyl hydroperoxide (tBHP)-induced cardiomyocyte apoptosis. The mRNA and protein expression of SCAD were significantly down-regulated in the cardiomyocyte apoptosis model. Inhibition of SCAD with siRNA-1186 significantly decreased SCAD expression, enzyme activity and ATP content, but obviously increased the content of free fatty acids. Meanwhile, SCAD siRNA treatment triggered the same apoptosis as cardiomyocytes treated with tBHP, such as the increase in cell apoptotic rate, the activation of caspase3 and the decrease in the Bcl-2/Bax ratio, which showed that SCAD may play an important role in primary cardiomyocyte apoptosis. The changes of phosphonate AMP-activated protein kinase α (p-AMPKα) and Peroxisome proliferator-activated receptor α (PPARα) in cardiomyocyte apoptosis were consistent with that of SCAD. Furthermore, PPARα activator fenofibrate and AMPKα activator AICAR treatment significantly increased the expression of SCAD and inhibited cardiomyocyte apoptosis. In conclusion, for the first time our findings directly demonstrated that SCAD may be as a new target to prevent cardiomyocyte apoptosis through the AMPK/PPARα/SCAD signal pathways. PMID:26989860

  19. Immune complex stimulation of neutrophil apoptosis: investigating the involvement of oxidative and nonoxidative pathways.

    PubMed

    Ottonello, L; Frumento, G; Arduino, N; Dapino, P; Tortolina, G; Dallegri, F

    2001-01-15

    Neutrophils are involved in the pathogenesis of various inflammatory diseases. One of the mechanisms by which neutrophilic inflammation is generated is immune complex (IC) deposition in tissue. As the clearance of apoptotic neutrophils from inflamed sites is considered a crucial determinant for the resolution of inflammation, we investigated the effects of IC-induced neutrophil activation on apoptosis and the mechanisms regulating neutrophil survival. Our results show that IC stimulated apoptosis efficiently. The percentage of apoptotic neutrophils was reduced by the anti-FcgammaRII mAb IV.3, but not by anti-FcgammaRIII mAb 3G8. The spontaneous apoptosis was completely inhibited by the antioxidant compound catalase, which in turn prevented only partially the apoptosis in presence of IC. The oxidative metabolism triggered by IC was inhibited only blocking both FcgammaRII and FcgammaRIII. Neutrophils from patients with chronic granulomatous disease, congenitally incapable of producing oxidants, showed low level of spontaneous apoptosis, but underwent a nearly 3-fold increment in the apoptosis rate when incubated with IC. In conclusion, neutrophil apoptosis appears to be a process governed by multiple pathways, some of which are strictly ROS-dependent, others acting in a nonoxidative manner. In particular, the herein shown FcgammaRII-dependent, ROS-independent, signal-inducing neutrophil apoptosis may uncover new pharmacological targets for the promotion of cell removal from sites of inflammation, thereby favoring the resolution of the inflammatory process. PMID:11163533

  20. 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

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

    PubMed

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

    2002-11-01

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

  2. Apoptosis deregulation in myeloproliferative neoplasms

    PubMed Central

    Tognon, Raquel; Nunes, Natália de Souza; de Castro, Fabíola Attié

    2013-01-01

    ABSTRACT Philadelphia-chromosome negative chronic myeloproliferative neoplasms are clonal hematologic diseases characterized by hematopoietic progenitor independence from or hypersensitivity to cytokines. The cellular and molecular mechanisms involved in the pathophysiology of myeloproliferative neoplasms have not yet been fully clarified. Pathophysiologic findings relevant for myeloproliferative neoplasms are associated with genetic alterations, such as, somatic mutation in the gene that codifies JAK-2 (JAK V617F). Deregulation of the process of programmed cellular death, called apoptosis, seems to participate in the pathogenesis of these disorders. It is known that expression deregulation of pro- and anti-apoptotic genes promotes cell resistance to apoptosis, culminating with the accumulation of myeloid cells and establishing neoplasms. This review will focus on the alterations in apoptosis regulation in myeloproliferative neoplasms, and the importance of a better understanding of this mechanism for the development of new therapies for these diseases. PMID:24488400

  3. Molecular mechanisms of hepatic apoptosis

    PubMed Central

    Wang, K

    2014-01-01

    Apoptosis is a prominent feature of liver diseases. Causative factors such as alcohol, viruses, toxic bile acids, fatty acids, drugs, and immune response, can induce apoptotic cell death via membrane receptors and intracellular stress. Apoptotic signaling network, including membrane death receptor-mediated cascade, reactive oxygen species (ROS) generation, endoplasmic reticulum (ER) stress, lysosomal permeabilization, and mitochondrial dysfunction, is intermixed each other, but one mechanism may dominate at a particular stage. Mechanisms of hepatic apoptosis are complicated by multiple signaling pathways. The progression of liver disease is affected by the balance between apoptotic and antiapoptotic capabilities. Therapeutic options of liver injury are impacted by the clear understanding toward mechanisms of hepatic apoptosis. PMID:24434519

  4. Monitoring apoptosis in real time.

    PubMed

    Green, Allan M; Steinmetz, Neil D

    2002-01-01

    Many therapeutically active anticancer treatments exert their effect by the induction of apoptosis and necrosis. Serial biopsies in breast cancer patients have suggested that response to therapy correlates with early posttreatment increases in tumor apoptotic index. Radiolabeled technetium Tc 99m-recombinant human (rh) annexin V provides a noninvasive technique for imaging treatment-induced cell death. Annexin V is a naturally occurring human protein that binds avidly to membrane-associated phosphatidylserine (PS). PS is normally found only on the inner leaflet of the cell membrane double layer, but it is actively transported to the outer layer as an early event in apoptosis and becomes available for annexin binding. Annexin also gains access to PS as a result of the membrane fragmentation associated with necrosis. In vitro studies of apoptosis using fluorescein annexin have shown good correlation with assessments of apoptosis documented by nuclear DNA degradation and caspase activation. In vivo localization of intravenously administered Tc 99m-annexin V has been demonstrated in numerous preclinical models of apoptosis, including anti-Fas-mediated hepatic apoptosis, rejection of allogeneic heterotopic cardiac allografts, cyclophosphamide treatment of murine lymphoma, cyclophosphamide-induced apoptosis in bone marrow, and leukocyte apoptosis associated with abscess formation. Scintigraphic studies in humans using Tc 99m-rh annexin V have demonstrated the feasibility of imaging cell death in acute myocardial infarction, in tumors with a high apoptotic index, and in response to anti-tumor chemotherapy of non-small cell lung cancer, small-cell lung cancer, breast cancer, lymphoma, and sarcoma. Increased localization of Tc 99m-rh annexin V within 1 to 3 days of chemotherapy has been noted in some, but not all, subjects with these tumors. To date, most subjects showing increased Tc 99m-rh annexin V uptake after the first course of chemotherapy have shown objective

  5. Nitric oxide-mediated apoptosis of neutrophils through caspase-8 and caspase-3-dependent mechanism.

    PubMed

    Dubey, Megha; Nagarkoti, Sheela; Awasthi, Deepika; Singh, Abhishek K; Chandra, Tulika; Kumaravelu, J; Barthwal, Manoj K; Dikshit, Madhu

    2016-01-01

    Neutrophils play an indispensable role in killing of invading pathogens by enhancing reactive oxygen species (ROS) and NO generation, and subsequently undergoing apoptosis. Unlike ROS/NOX2, role of NO/NOS still remains undefined in the apoptosis of neutrophils (PMNs) and the present study attempts to decipher the importance of NO/NOS in the neutrophil apoptosis. Prolonged treatment of human PMNs or mice bone marrow derived neutrophils (BMDN) with NO led to enhanced ROS generation, caspase-8/caspase-3 cleavage, reduced mitochondrial membrane potential and finally cellular apoptosis. NO-induced ROS generation led to caspase-8 deglutathionylation and activation, which subsequently activated mitochondrial death pathway via BID (Bcl-2 family protein) cleavage. NO-mediated augmentation of caspase-8 and BID cleavage was significantly prevented in BMDN from neutrophil cytosolic factor-1 (NCF-1) knockout (KO) mice, implying the involvement of NOX2 in NO-induced apoptosis of PMNs. Furthermore, ROS, NO generation and inducible nitric oxide synthase (iNOS) expression were enhanced in a time-dependent manner in human PMNs and mice BMDN undergoing spontaneous apoptosis. Pharmacological and genetic ablation of iNOS in human PMNs and mice BMDN significantly reduced the levels of apoptosis. Impaired apoptosis of BMDN from iNOS KO mice was due to reduced caspase-8 activity which subsequently prevented caspase-3 and -9 activation. Altogether, our results suggest a crucial role of NO/iNOS in neutrophil apoptosis via enhanced ROS generation and caspase-8 mediated activation of mitochondrial death pathway. PMID:27584786

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

    SciTech Connect

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

    2014-04-01

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

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

    PubMed

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

    2015-03-01

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

  8. 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

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

    PubMed Central

    2014-01-01

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

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

    PubMed

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

    2014-10-01

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

  11. The roles of Bcl-xL in modulating apoptosis during development of Xenopus laevis

    PubMed Central

    Johnston, Jillian; Chan, Robert; Calderon-Segura, Maria; McFarlane, Sarah; Browder, Leon W

    2005-01-01

    Background Apoptosis is a common and essential aspect of development. It is particularly prevalent in the central nervous system and during remodelling processes such as formation of the digits and in amphibian metamorphosis. Apoptosis, which is dependent upon a balance between pro- and anti-apoptotic factors, also enables the embryo to rid itself of cells damaged by gamma irradiation. In this study, the roles of the anti-apoptotic factor Bcl-xL in protecting cells from apoptosis were examined in Xenopus laevis embryos using transgenesis to overexpress the XR11 gene, which encodes Bcl-xL. The effects on developmental, thyroid hormone-induced and γ-radiation-induced apoptosis in embryos were examined in these transgenic animals. Results Apoptosis was abrogated in XR11 transgenic embryos. However, the transgene did not prevent the apoptotic response of tadpoles to thyroid hormone during metamorphosis. Post-metamorphic XR11 frogs were reared to sexual maturity, thus allowing us to produce second-generation embryos and enabling us to distinguish between the maternal and zygotic contributions of Bcl-xL to the γ-radiation apoptotic response. Wild-type embryos irradiated before the mid-blastula transition (MBT) underwent normal cell division until reaching the MBT, after which they underwent massive, catastrophic apoptosis. Over-expression of Bcl-xL derived from XR11 females, but not males, provided partial protection from apoptosis. Maternal expression of XR11 was also sufficient to abrogate apoptosis triggered by post-MBT γ-radiation. Tolerance to post-MBT γ-radiation from zygotically-derived XR11 was acquired gradually after the MBT in spite of abundant XR11 protein synthesis. Conclusion Our data suggest that Bcl-xL is an effective counterbalance to proapoptotic factors during embryonic development but has no apparent effect on the thyroid hormone-induced apoptosis that occurs during metamorphosis. Furthermore, post-MBT apoptosis triggered by irradiation before the

  12. Dietary flavonoids as cancer prevention agents.

    PubMed

    Yao, Hua; Xu, Weizheng; Shi, Xianglin; Zhang, Zhuo

    2011-01-01

    Dietary agents identified from fruits and vegetables contribute to keeping balanced cell proliferation and preventing cell carcinogenesis. Dietary flavonoids, combined with other components such as various vitamins, play an important role in cancer prevention. Flavonoids act on reactive oxygen species, cell signal transduction pathways related to cellular proliferation, apoptosis, and angiogenesis. Many studies demonstrate that flavonoids are responsible for chemoprevention, although mechanisms of action remain to be investigated. Overall, exciting data show that dietary flavonoids could be considered as a useful cancer preventive approach. This review summarizes recent advancements on potential cancer preventive effects and mechanic insight of dietary flavonoids. PMID:21424974

  13. Proteasome inhibitors prevent cell death and prolong survival of mice challenged by Shiga toxin

    PubMed Central

    Hattori, Takayuki; Watanabe-Takahashi, Miho; Ohoka, Nobumichi; Hamabata, Takashi; Furukawa, Koichi; Nishikawa, Kiyotaka; Naito, Mikihiko

    2015-01-01

    Shiga toxin (Stx) causes fatal systemic complications. Stx induces apoptosis, but the mechanism of which is unclear. We report that Stx induced rapid reduction of short-lived anti-apoptotic proteins followed by activation of caspase 9 and the progression of apoptosis. Proteasome inhibitors prevented the reduction of anti-apoptotic proteins, and inhibited caspase activation and apoptosis, suggesting that the reduction of anti-apoptotic proteins is a prerequisite for Stx-induced apoptosis. A clinically approved proteasome inhibitor, bortezomib, prolonged the survival of mice challenged by Stx. These results imply that proteasome inhibition may be a novel approach to prevent the fatal effects of Stx. PMID:26273560

  14. Pancreatic carcinogenesis: apoptosis and angiogenesis.

    PubMed

    Onizuka, Shinya; Kawakami, Shunsuke; Taniguchi, Ken; Fujioka, Hikaru; Miyashita, Kosei

    2004-04-01

    Apoptosis and angiogenesis are critical biologic processes that are altered during carcinogenesis. Both apoptosis and angiogenesis may play an important role in pancreatic carcinogenesis. Despite numerous advances in the diagnosis and treatment of pancreatic cancer, its prognosis remains dismal and a new therapeutic approach is much needed. Recent research has revealed that apoptosis and angiogenesis are closely interrelated. Several reports show that a tumor suppresser gene that is expressed in pancreatic carcinoma and related to malignant potential can induce apoptosis and also inhibit angiogenesis. At present, it is generally accepted that tumor growth in cancers, including pancreatic cancer, depends on angiogenesis. We have identified 2 new angiogenesis inhibitors from a conditioned medium of human pancreatic carcinoma cell line (BxPC-3): antiangiogenic antithrombin III (aaAT-III) and vitamin D binding protein-macrophage activating factor (DBP-maf). These molecules were able to regress tumors in severe combined immunodeficiency disease (SCID) mice, demonstrating potent inhibition of endothelial cell proliferation. Moreover, the angiogenesis inhibitors induced tumor dormancy in the animal model. These results suggest that antiangiogenic therapy using angiogenesis inhibitors may become a new strategy for treatment of pancreatic cancer in the near future. PMID:15084979

  15. Fluorescence Lifetime Imaging of Apoptosis

    PubMed Central

    Xiao, Annie; Gibbons, Anne E.; Luker, Kathryn E.; Luker, Gary D.

    2015-01-01

    Genetically-encoded fluorescence resonance energy transfer (FRET) reporters are powerful tools to analyze cell signaling and function at single cell resolution in standard two-dimensional cell cultures, but these reporters rarely have been applied to three-dimensional environments. FRET interactions between donor and acceptor molecules typically are determined by changes in relative fluorescence intensities, but wavelength-dependent differences in absorption of light complicate this analysis method in three-dimensional settings. Here we report fluorescence lifetime imaging microscopy (FLIM) with phasor analysis, a method that displays fluorescence lifetimes on a pixel-wise basis in real time, to quantify apoptosis in breast cancer cells stably expressing a genetically encoded FRET reporter. This microscopic imaging technology allowed us to identify treatment-induced apoptosis in single breast cancer cells in environments ranging from two-dimensional cell culture, spheroids with cancer and bone marrow stromal cells, and living mice with orthotopic human breast cancer xenografts. Using this imaging strategy, we showed that combined metabolic therapy targeting glycolysis and glutamine pathways significantly reduced overall breast cancer metabolism and induced apoptosis. We also determined that distinct subpopulations of bone marrow stromal cells control resistance of breast cancer cells to chemotherapy, suggesting heterogeneity of treatment responses of malignant cells in different bone marrow niches. Overall, this study establishes FLIM with phasor analysis as an imaging tool for apoptosis in cell-based assays and living mice, enabling real-time, cellular-level assessment of treatment efficacy and heterogeneity. PMID:26771007

  16. 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.

  17. Calmodulin antagonists induce platelet apoptosis.

    PubMed

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

    2010-04-01

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

  18. Modulation of apoptosis by mitochondrial uncouplers: apoptosis-delaying features despite intrinsic cytotoxicity.

    PubMed

    Stoetzer, Oliver J; Pogrebniak, Alexei; Pelka-Fleischer, Renate; Hasmann, Max; Hiddemann, Wolfgang; Nuessler, Volkmar

    2002-02-01

    Disruption of mitochondrial electron transport and opening of the so-called mitochondrial permeability transition pores (PTPs) are early events in apoptotic cell death and may be caused by the uncoupler of mitochondrial oxidation and phosphorylation, carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP). We investigated the cellular toxicity of FCCP in HL60 and CCRF-CEM cells alone or in combination with the known apoptosis inducers such as inhibitor of serine/threonine protein kinases staurosporine (Sts) and protein kinase C inhibitor chelerythrine. FCCP induced apoptotic cell death in both cell lines in a dose-dependent manner, and we were able to demonstrate an appearance of caspase-3-dependent PARP cleavage fragments with Western blot and the appearance of large (15-50 kb) DNA fragments using pulsed-field gel electrophoresis. After 2 hr of incubation with Che or Sts more than half of the cells had died by apoptosis. We observed a statistically significant delay in Sts- and Che-induced apoptotic cell death in CCRF-CEM cells when the cells were preincubated with FCCP but not with zVAD-FMK: about 50% more cells survived after pre-treatment with FCCP, as compared to 1 hr treatment with Che alone (P<0.05), and 25% more cells were alive after 6 hr of treatment, as compared to 6 hr exposure to Sts alone (P<0.05). The protective effect of FCCP was, however, transient and lasted only 6 hr. Treatment with aurintricarboxylic acid completely prevented Che- and Sts-induced apoptotic cell death in CCRF-CEM and HL60 cells. Incubation with Che resulted in a drop in the intracellular ATP content, predominantly distinctive in HL60, and in NAD(+) content in CCRF-CEM cells. Both ATP and NAD(+) drop were prevented with ATA, but not with FCCP or zVAD. Our data suggest that treatment with uncouplers of oxidative phosphorylation can induce apoptotic cell death in haematopoietic cell lines. However, when used in combination with serine/threonine protein kinase inhibitors FCCP can

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

    PubMed Central

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

    2002-01-01

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

  20. Fructose Protects Murine Hepatocytes from Tumor Necrosis Factor-induced Apoptosis by Modulating JNK Signaling*

    PubMed Central

    Speicher, Tobias; Köhler, Ulrike A.; Choukèr, Alexander; Werner, Sabine; Weiland, Timo; Wendel, Albrecht

    2012-01-01

    Fructose-induced hepatic ATP depletion prevents TNF-induced apoptosis, whereas it contrarily enhances CD95-induced hepatocyte apoptosis in vitro and in vivo. By contrast, transformed liver cells are not protected against TNF due to metabolic alterations, allowing selective tumor targeting. We analyzed the molecular mechanisms by which fructose modulates cytokine-induced apoptosis. A release of adenosine after fructose-induced ATP depletion, followed by a cAMP response, was demonstrated. Likewise, cAMP and adenosine mimicked per se the modulation by fructose of CD95- and TNF-induced apoptosis. The effects of fructose on cytokine-induced apoptosis were sensitive to inhibition of protein kinase A. Fructose prevented the pro-apoptotic, sustained phase of TNF-induced JNK signaling and thereby blocked bid-mediated activation of the intrinsic mitochondrial apoptosis pathway in a PKA-dependent manner. We explain the dichotomal effects of fructose on CD95- and TNF-induced cell death by the selective requirement of JNK signaling for the latter. These findings provide a mechanistic rationale for the protection of hepatocytes from TNF-induced cell death by pharmacological doses of fructose. PMID:22086922

  1. Protection against apoptosis in chicken bursa and thymus cells by phorbol ester in vitro

    SciTech Connect

    Asakawa, J.; Thorbecke, G.J. )

    1991-03-15

    Programmed suicide or apoptosis, due to activation of endogenous nucleases, occurs in immature CD4{sup {minus}}85{sup {minus}} mammalian thymus cells. Like the thymus, the bursa of Fabricius is a site of massive lymphopoiesis accompanied by cell death in vivo. In the present study the authors have, therefore, examined whether chicken bursa and thymus cells exhibit apoptosis. Bursa and thymus cells from SC chickens, 4-10 weeks of age, were incubated for 8-24 hrs with various reagents. Genomic DNA was isolated, electrophoresed in 3% Nusieve agarose gels, and examined for patterns of DNA fragmentation. A laddering of DNA in multiples of 200 base pairs, indicative of apoptosis, was observed with both bursa and thymus cells. These patterns of DNA fragmentation from bursa cells could be prevented by adding phorbol myristic acetate during culture and, more effectively, by PMA plus ionomycin, but not by ionomycin alone or by anti-{mu}. PMA did not affect the patterns of DNA fragmentation seen with spleen cells. Addition of the protein kinase C inhibitor staurosporin inhibited the preventive effect of PMA on apoptosis. PMA also greatly promoted the survival of bursa cells in culture, as assayed by percentage cell death and by {sup 3}H-thymidine incorporation. It is concluded that bursa and thymus cells from the chicken exhibit apoptosis. The data further suggest that protein kinase C activation protects apoptosis in cultured bursa cells.

  2. TAT-BH4 and TAT-Bcl-xL peptides protect against sepsis-induced lymphocyte apoptosis in vivo.

    PubMed

    Hotchkiss, Richard S; McConnell, Kevin W; Bullok, Kristin; Davis, Christopher G; Chang, Katherine C; Schwulst, Steven J; Dunne, Jeffrey C; Dietz, Gunnar P H; Bähr, Mathias; McDunn, Jonathan E; Karl, Irene E; Wagner, Tracey H; Cobb, J Perren; Coopersmith, Craig M; Piwnica-Worms, David

    2006-05-01

    Apoptosis is a key pathogenic mechanism in sepsis that induces extensive death of lymphocytes and dendritic cells, thereby contributing to the immunosuppression that characterizes the septic disorder. Numerous animal studies indicate that prevention of apoptosis in sepsis improves survival and may represent a potential therapy for this highly lethal disorder. Recently, novel cell-penetrating peptide constructs such as HIV-1 TAT basic domain and related peptides have been developed to deliver bioactive cargoes and peptides into cells. In the present study, we investigated the effects of sepsis-induced apoptosis in Bcl-x(L) transgenic mice and in wild-type mice treated with an antiapoptotic TAT-Bcl-x(L) fusion protein and TAT-BH4 peptide. Lymphocytes from Bcl-x(L) transgenic mice were resistant to sepsis-induced apoptosis, and these mice had a approximately 3-fold improvement in survival. TAT-Bcl-x(L) and TAT-BH4 prevented Escherichia coli-induced human lymphocyte apoptosis ex vivo and markedly decreased lymphocyte apoptosis in an in vivo mouse model of sepsis. In conclusion, TAT-conjugated antiapoptotic Bcl-2-like peptides may offer a novel therapy to prevent apoptosis in sepsis and improve survival. PMID:16622015

  3. Preventing Suicide

    MedlinePlus

    ... The top three methods used in suicides include firearms (49.9%), suffocation (26.7%), and poisoning (15. ... Content source: National Center for Injury Prevention and Control, Division of Violence Prevention Page maintained by: Office ...

  4. Drowning Prevention

    MedlinePlus

    ... Listen Español Text Size Email Print Share Drowning Prevention: Information for Parents Page Content Article Body Drowning ... in very cold water for lengthy periods. Drowning Prevention: Know the Warning Signs These signs may signal ...

  5. Angiotensin II induces apoptosis in intestinal epithelial cells through the AT2 receptor, GATA-6 and the Bax pathway

    SciTech Connect

    Sun, Lihua; Wang, Wensheng; Xiao, Weidong; Liang, Hongyin; Yang, Yang; Yang, Hua

    2012-08-10

    Highlights: Black-Right-Pointing-Pointer Ang II-induced apoptosis in intestinal epithelial cell through AT2 receptor. Black-Right-Pointing-Pointer The apoptosis process involves in the Bax/Bcl-2 intrinsic pathway. Black-Right-Pointing-Pointer GATA-6 short hairpin RNA reduced Bax expression, but not Bcl-2. Black-Right-Pointing-Pointer GATA-6 may play a critical role in apoptosis in response to the Ang II challenge. -- Abstract: Angiotensin II (Ang II) has been shown to play an important role in cell apoptosis. However, the mechanisms of Ang-II-induced apoptosis in intestinal epithelial cells are not fully understood. GATA-6 is a zinc finger transcription factor expressed in the colorectal epithelium, which directs cell proliferation, differentiation and apoptosis. In the present study we investigated the underlying mechanism of which GATA-6 affects Ang-II induced apoptosis in intestinal epithelial cells. The in vitro intestinal epithelial cell apoptosis model was established by co-culturing Caco-2 cells with Ang II. Pretreatment with Angiotensin type 2 (AT2) receptor antagonist, PD123319, significantly reduced the expression of Bax and prevented the Caco-2 cells apoptosis induced by Ang II. In addition, Ang II up-regulated the expression of GATA-6. Interestingly, GATA-6 short hairpin RNA prevented Ang II-induced intestinal epithelial cells apoptosis and reduced the expression of Bax, but not Bcl-2. Taken together, the present study suggests that Angiotensin II promotes apoptosis in intestinal epithelial cells through GATA-6 and the Bax pathway in an AT2 receptor-dependent manner.

  6. Prostaglandin E2 inhibits apoptosis in human neutrophilic polymorphonuclear leukocytes: role of intracellular cyclic AMP levels.

    PubMed

    Ottonello, L; Gonella, R; Dapino, P; Sacchetti, C; Dallegri, F

    1998-08-01

    Human neutrophilic polymorphonuclear leukocytes (neutrophils) are terminally differentiated cells that die by undergoing apoptosis. At present, the intracellular pathways governing this process are only partially known. In particular, although the adenylate cyclase-dependent generation of cyclic AMP (cAMP) has been implicated in the triggering of apoptosis in lymphoid cells, the role of the intracellular cAMP pathway in neutrophil apoptosis remains controversial. In the present study, we found that two cAMP-elevating agents, prostaglandin E2 (PGE2) and the phosphodiesterase type IV inhibitor RO 20-1724, inhibit neutrophil apoptosis without inducing cell necrosis. When administered in combination, PGE2 and RO 20-1724 displayed additive effects. Moreover, neutrophil apoptosis was inhibited by a membrane-permeable analog of cAMP, dibutyryl-cAMP, in a dose-dependent manner. Finally, treatment of neutrophils with the protein kinase A inhibitor H-89 prevented PGE2- and RO 20-1724-induced inhibition of cell apoptosis. In conclusion, taking into account that PGE2 and other cAMP-elevating agents are well known downregulators of neutrophil functions, our results suggest that conditions favoring a state of functional rest, such as intracellular cAMP elevation, prolong the life span of neutrophils by delaying apoptosis. PMID:9694511

  7. p51/p63 Inhibits ultraviolet B-induced apoptosis via Akt activation.

    PubMed

    Ogawa, E; Okuyama, R; Ikawa, S; Nagoshi, H; Egawa, T; Kurihara, A; Yabuki, M; Tagami, H; Obinata, M; Aiba, S

    2008-01-31

    The epidermis must be protected against excess apoptotic cell death in response to ultraviolet-B (UV-B) irradiation. p53 is known to be critical for this protection. Although the p53 family member DeltaNp51B/DeltaNp63alpha (an N terminal-deleted form of p51/p63) is abundantly expressed in keratinocytes, its contribution to UV-B-dependent apoptosis is largely unknown. We found that, after a transient increase, DeltaNp51B is downregulated in UV-B-irradiated keratinocytes undergoing apoptosis, whereas p53 is upregulated with delayed kinetics. Furthermore, the reduction of DeltaNp51B by small interfering RNAs augmented UV-B-dependent apoptosis in keratinocytes, indicating that DeltaNp51B blocks keratinocyte apoptosis. Although the exogenous expression of DeltaNp51B in keratinocytes did not further block the UV-B-dependent apoptosis, to our surprise the expression of TAp51B (an isoform with a full NH(2)-terminal transactivation domain that is structurally and functionally similar to p53) decreased apoptosis significantly. The blockade of keratinocyte apoptosis by the p51 was dependent on the phosphorylation of Akt, resulting in the activation of a survival pathway. Thus, in addition to its indispensable roles in epithelial development, p51 acts in adult cells to protect the epidermis against UV-B irradiation by preventing excess depletion of keratinocytes. PMID:17653081

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

    PubMed

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

    2016-01-01

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

  9. Caspase-2 is an initiator caspase responsible for pore-forming toxin-mediated apoptosis.

    PubMed

    Imre, Gergely; Heering, Jan; Takeda, Armelle-Natsuo; Husmann, Matthias; Thiede, Bernd; zu Heringdorf, Dagmar Meyer; Green, Douglas R; van der Goot, F Gisou; Sinha, Bhanu; Dötsch, Volker; Rajalingam, Krishnaraj

    2012-05-30

    Bacterial pathogens modulate host cell apoptosis to establish a successful infection. Pore-forming toxins (PFTs) secreted by pathogenic bacteria are major virulence factors and have been shown to induce various forms of cell death in infected cells. Here we demonstrate that the highly conserved caspase-2 is required for PFT-mediated apoptosis. Despite being the second mammalian caspase to be identified, the role of caspase-2 during apoptosis remains enigmatic. We show that caspase-2 functions as an initiator caspase during Staphylococcus aureus α-toxin- and Aeromonas aerolysin-mediated apoptosis in epithelial cells. Downregulation of caspase-2 leads to a strong inhibition of PFT-mediated apoptosis. Activation of caspase-2 is PIDDosome-independent, and endogenous caspase-2 is recruited to a high-molecular-weight complex in α-toxin-treated cells. Interestingly, prevention of PFT-induced potassium efflux inhibits the formation of caspase-2 complex, leading to its inactivation, thus resisting apoptosis. These results revealed a thus far unknown, obligatory role for caspase-2 as an initiator caspase during PFT-mediated apoptosis. PMID:22531785

  10. Chlorpromazine Protects Against Apoptosis Induced by Exogenous Stimuli in the Developing Rat Brain

    PubMed Central

    Li, Yujun; Zhang, Qingmeng; Chen, Yang; Fu, Yingmei; Fang, Wenjuan; Wang, Jindong; Zhong, Zhaohua; Ling, Hong; Zhang, Liming; Zhang, Fengmin

    2011-01-01

    Background Chlorpromazine (CPZ), a commonly used antipsychotic drug, was found to play a neuroprotective role in various models of toxicity. However, whether CPZ has the potential to affect brain apoptosis in vivo is still unknown. The purpose of this study was to investigate the potential effect of CPZ on the apoptosis induced by exogenous stimuli. Methodology The ethanol treated infant rat was utilized as a valid apoptotic model, which is commonly used and could trigger robust apoptosis in brain tissue. Prior to the induction of apoptosis by subcutaneous injection of ethanol, 7-day-old rats were treated with CPZ at several doses (5 mg/kg, 10 mg/kg and 20 mg/kg) by intraperitoneal injection. Apoptotic cells in the brain were measured using TUNEL analysis, and the levels of cleaved caspase-3, cytochrome c, the pro-apoptotic factor Bax and the anti-apoptotic factor Bcl-2 were assessed by immunostaining or western blot. Findings Compared to the group injected with ethanol only, the brains of the CPZ-pretreated rats had fewer apoptotic cells, lower expression of cleaved caspase-3, cytochrome c and Bax, and higher expression of Bcl-2. These results demonstrate that CPZ could prevent apoptosis in the brain by regulating the mitochondrial pathway. Conclusions CPZ exerts an inhibitory effect on apoptosis induced by ethanol in the rat brain, intimating that it may offer a means of protecting nerve cells from apoptosis induced by exogenous stimuli. PMID:21779358

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

    PubMed

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

    2016-02-01

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

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

    PubMed Central

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

    2016-01-01

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

  13. Pharmacological induction of cell surface GRP78 contributes to apoptosis in triple negative breast cancer cells.

    PubMed

    Raiter, Annat; Yerushalmi, Rinat; Hardy, Britta

    2014-11-30

    Breast cancer tumor with triple-negative receptors (estrogen, progesterone and Her 2, receptors) is the most aggressive and deadly subtype, with high rates of disease recurrence and poor survival. Here, we show that induction in cell surface GRP78 by doxorubicin and tunicamycin was associated with CHOP/GADD153 upregulation and increase in apoptosis in triple negative breast cancer tumor cells. GRP78 is a major regulator of the stress induced unfolded protein response pathway and CHOP/GADD153 is a pro-apoptotic transcription factor associated exclusively with stress induced apoptosis. The blocking of cell surface GRP78 by anti-GRP78 antibody prevented apoptosis, suggesting that induction of cell surface GRP78 by doxorubicin and tunicamycin is required for apoptosis. A better understanding of stress induction of apoptotic signaling in triple negative breast cancer cells may help to define new therapeutic strategies. PMID:25360516

  14. Bim mediates mitochondria-regulated particulate matter-induced apoptosis in alveolar epithelial cells

    PubMed Central

    Zhang, J.; Ghio, A.J.; Chang, W.; Kamdar, O.; Rosen, G.D.; Upadhyay, D.

    2007-01-01

    We studied the role of Bim, a pro-apoptotic BCL-2 family member in Airborne particulate matter (PM 2.5 μm)-induced apoptosis in alveolar epithelial cells (AEC). PM induced AEC apoptosis by causing significant reduction of mitochondrial membrane potential and increase in caspase-9, caspase-3 and PARP-1 activation. PM upregulated pro-apoptotic protein Bim and enhanced translocation of Bim to the mitochondria. ShRNABim blocked PM-induced apoptosis by preventing activation of the mitochondrial death pathway suggesting a role of Bim in the regulation of mitochondrial pathway in AEC. Accordingly, we provide the evidence that Bim mediates PM-induced apoptosis via mitochondrial pathway. PMID:17716672

  15. Phloroglucinol induces apoptosis via apoptotic signaling pathways in HT-29 colon cancer cells

    PubMed Central

    KANG, MI-HYE; KIM, IN-HYE; NAM, TAEK-JEO NG

    2014-01-01

    Phloroglucinol is a polyphenolic compound that is used to treat and prevent several human diseases, as it exerts beneficial biological activities, including anti-oxidant, anti-inflammatory and anticancer properties. The aim of the present study was to investigate the effects of phloroglucinol on apoptotic signaling pathways in HT-29 colon cancer cells. The results indicated that phloroglucinol suppressed cell viability and induced apoptosis in HT-29 cells in a concentration-dependent manner. Phloroglucinol treatment of HT-29 cells resulted in characteristic apoptosis-related changes: altered Bcl-2 family proteins, cytochrome c release, and activation of caspase-3 and caspase-8. This study also showed that proteins involved in apoptosis were stimulated by treatment with phloroglucinol. These findings demonstrated that phloroglucinol exerts anticancer activity in HT-29 colon cancer cells through induction of apoptosis. PMID:25070748

  16. Deficiency in glutamine but not glucose induces MYC-dependent apoptosis in human cells

    PubMed Central

    Yuneva, Mariia; Zamboni, Nicola; Oefner, Peter; Sachidanandam, Ravi; Lazebnik, Yuri

    2007-01-01

    The idea that conversion of glucose to ATP is an attractive target for cancer therapy has been supported in part by the observation that glucose deprivation induces apoptosis in rodent cells transduced with the proto-oncogene MYC, but not in the parental line. Here, we found that depletion of glucose killed normal human cells irrespective of induced MYC activity and by a mechanism different from apoptosis. However, depletion of glutamine, another major nutrient consumed by cancer cells, induced apoptosis depending on MYC activity. This apoptosis was preceded by depletion of the Krebs cycle intermediates, was prevented by two Krebs cycle substrates, but was unrelated to ATP synthesis or several other reported consequences of glutamine starvation. Our results suggest that the fate of normal human cells should be considered in evaluating nutrient deprivation as a strategy for cancer therapy, and that understanding how glutamine metabolism is linked to cell viability might provide new approaches for treatment of cancer. PMID:17606868

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

    PubMed

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

    2012-11-01

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

  18. Relationship between Eimeria tenella development and host cell apoptosis in chickens.

    PubMed

    Zhang, Yan; Zheng, Ming-xue; Xu, Zhi-yong; Xu, Huan-cheng; Cui, Xiao-zhen; Yang, Sha-sha; Zhao, Wen-long; Li, Shan; Lv, Qiang-hua; Bai, Rui

    2015-12-01

    Coccidiosis causes considerable economic losses in the poultry industry. At present, the pathology of coccidiosis is preventable with anticoccidials and vaccination, although at considerable cost to the international poultry industry. The purpose of the present study was to elucidate the relationship between Eimeria tenella development and host cell apoptosis in chickens, which provides a theoretical basis for further study of the injury mechanism of E. tenella and the prevention and treatment of coccidiosis. Cecal epithelial cells from chick embryo were used as host cells in vitro. In addition, flow cytometry, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP) nick-end labeling, and histopathological assays were used to detect the dynamic changes in E. tenella infection rates, DNA injury rates, and apoptosis rates in groups treated with and without the caspase-9 inhibitor Z-LEHD-FMK. Following E. tenella infection, we demonstrated that untreated cells had less apoptosis at 4 h and, inversely, more apoptosis at 24 to 120 h compared with control cells. Furthermore, after the application of Z-LEHD-FMK, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assays, and translation of phosphatidyl serines to the host cell plasma membrane surface, the treated group chick embryo cecal epithelial cells exhibited decreased apoptosis and DNA injuries (P<0.01) at 24 to 120 h. However, light microscopy showed that E. tenella infection rates of treated cells were higher (P<0.01) than untreated cells during the whole experimental period. Together, these observations suggest that E. tenella can protect host cells from apoptosis at early stages of development but can promote apoptosis during the middle to late stages. In addition, the inhibition of host cell apoptosis can be beneficial to the intracellular growth and development of E. tenella. PMID:26467006

  19. [PHARMACOLOGICAL CORRECTION OF APOPTOSIS LEVEL OF CORTICAL NEURONS IN AGED HER2/NEU TRANSGENIC MICE].

    PubMed

    Bazhanova, E D; Kozlova, Yu O; Anisimov, V N; Sukhanov, D S; Teply, D L

    2016-01-01

    Neurodegenerative changes and neuronal death are the basis for development of the nervous system aging. We investigated the mechanism of apoptosis of the sensorimotor cortex neurons of transgenic mice HER2/neu during aging, changes in the cortex function and the participation of exogenous neurometabolites (cytoflavin, piracetam) in regulation of neuronal death and locomotor and psycho-emotional status of mice. The level of apoptosis and expression of apoptosis markers (TUNEL, immunohistochemistry, Western blotting) in HER2/neu transgenic mice as compared to wild type mice (FBV line) were determined. In aging FBV mice the basal activity was shown to decrease and anxiety to increase correlating with the high level of neuronal apoptosis. We identified behavioral characteristics of transgenic HER2/neu mice and found that their low basal activity does not change with aging. Previously we have shown that in this strain of mice the apoptosis level is low, without any age-related changes, due to the suppression, first of all, of the p53-dependent pathway by HER2 (tyrosine kinase receptor) overexpression. Cytoflavin and piracetam were revealed to possess a marked neuroprotective effect, preserving and restoring functions of the nervous system (improving locomotion and psychological status) in both strains of mice. The effect of neurometabolites studied on neuronal apoptosis is ambiguous. In case of its low level it is a moderate stumulation of apoptosis via the external p53-dependent pathways with activation of caspase-3 in transgenic HER2/neu mice with high carcinogenesis level that can possibly prevent tumor development. On the contrary, in old wild-type animals we observed a significant decrease of age-dependent apoptosis level (by stimulating expression of the anti-apoptotic protein Mcl-1), which prevents neurodegeneration. PMID:27220241

  20. Pathologies Associated with the p53 Response

    PubMed Central

    Gudkov, Andrei V.; Komarova, Elena A.

    2010-01-01

    Although p53 is a major cancer preventive factor, under certain extreme stress conditions it may induce severe pathologies. Analyses of animal models indicate that p53 is largely responsible for the toxicity of ionizing radiation or DNA damaging drugs contributing to hematopoietic component of acute radiation syndrome and largely determining severe adverse effects of cancer treatment. p53-mediated damage is strictly tissue specific and occurs in tissues prone to p53-dependent apoptosis (e.g., hematopoietic system and hair follicles); on the contrary, p53 can serve as a survival factor in tissues that respond to p53 activation by cell cycle arrest (e.g., endothelium of small intestine). There are multiple experimental indications that p53 contributes to pathogenicity of acute ischemic diseases. Temporary reversible suppression of p53 by small molecules can be an effective and safe approach to reduce severity of p53-associated pathologies. PMID:20595398

  1. 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

  2. Inhibitors of apoptosis catch ubiquitin.

    PubMed

    Rajalingam, Krishnaraj; Dikic, Ivan

    2009-01-01

    IAP (inhibitor of apoptosis) proteins are a class of anti-apoptotic regulators characterized by the presence of BIR (baculoviral IAP repeat) domains. Some of the IAPs also possess a RING (really interesting new gene) domain with E3 ubiquitin ligase activity. In this issue of the Biochemical Journal, Blankenship et al. unveil the presence of an UBA (ubiquitin-associated domain) in several IAPs. UBAs in c-IAPs (cellular IAPs) bind to monoubiquitin and ubiquitin chains and are implicated in degradation of c-IAPs by promoting their interaction with proteasomes as well as in regulation of TNF-alpha (tumour necrosis factor-alpha)-induced apoptosis. These novel observations establish IAPs as ubiquitin-interacting proteins and opens up new lines of investigation. PMID:19061481

  3. Apoptosis in irradiated murine tumors.

    PubMed

    Stephens, L C; Ang, K K; Schultheiss, T E; Milas, L; Meyn, R E

    1991-09-01

    Early radiation responses of transplantable murine ovarian (OCaI) and hepatocellular (HCaI) carcinomas were examined at 6, 24, 48, 96, and 144 h after single photon doses of 25, 35, or 45 Gy. Previous studies using tumor growth delay and tumor radiocurability assays had shown OCaI tumors to be relatively radiosensitive and HCaI tumors to be radioresistant. At 6 h, approximately 20% of nuclei in OCaI tumors showed aberrations characteristic of cell death by apoptosis. This contrasted to an incidence of 3% in HCaI tumors. Mitotic activity was eliminated in OCaI tumors but was only transiently suppressed in HCaI tumors. At 24-96 h, OCaI tumors continued to display apoptosis and progressive necrosis, whereas HCaI tumors responded by exhibiting marked pleomorphism. Factors other than mitotic activity may influence tumor radiosensitivity, and one of these may be susceptibility to induction of apoptosis (programmed cell death), because this was a prominent early radiation response by the radiosensitive OCaI tumors. PMID:1886987

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

    PubMed

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

    2013-07-01

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

  5. Pneumolysin Activates Macrophage Lysosomal Membrane Permeabilization and Executes Apoptosis by Distinct Mechanisms without Membrane Pore Formation

    PubMed Central

    Bewley, Martin A.; Naughton, Michael; Preston, Julie; Mitchell, Andrea; Holmes, Ashleigh; Marriott, Helen M.; Read, Robert C.; Mitchell, Timothy J.; Whyte, Moira K. B.

    2014-01-01

    ABSTRACT Intracellular killing of Streptococcus pneumoniae is complemented by induction of macrophage apoptosis. Here, we show that the toxin pneumolysin (PLY) contributes both to lysosomal/phagolysosomal membrane permeabilization (LMP), an upstream event programing susceptibility to apoptosis, and to apoptosis execution via a mitochondrial pathway, through distinct mechanisms. PLY is necessary but not sufficient for the maximal induction of LMP and apoptosis. PLY’s ability to induce both LMP and apoptosis is independent of its ability to form cytolytic pores and requires only the first three domains of PLY. LMP involves TLR (Toll-like receptor) but not NLRP3/ASC (nucleotide-binding oligomerization domain [Nod]-like receptor family, pyrin domain-containing protein 3/apoptosis-associated speck-like protein containing a caspase recruitment domain) signaling and is part of a PLY-dependent but phagocytosis-independent host response that includes the production of cytokines, including interleukin-1 beta (IL-1β). LMP involves progressive and selective permeability to 40-kDa but not to 250-kDa fluorescein isothiocyanate (FITC)-labeled dextran, as PLY accumulates in the cytoplasm. In contrast, the PLY-dependent execution of apoptosis requires phagocytosis and is part of a host response to intracellular bacteria that also includes NO generation. In cells challenged with PLY-deficient bacteria, reconstitution of LMP using the lysomotrophic detergent LeuLeuOMe favored cell necrosis whereas PLY reconstituted apoptosis. The results suggest that PLY contributes to macrophage activation and cytokine production but also engages LMP. Following bacterial phagocytosis, PLY triggers apoptosis and prevents macrophage necrosis as a component of a broad-based antimicrobial strategy. This illustrates how a key virulence factor can become the focus of a multilayered and coordinated innate response by macrophages, optimizing pathogen clearance and limiting inflammation. PMID:25293758

  6. The protective effect of GM-CSF on serum-induced neutrophil apoptosis in juvenile systemic lupus erythematosus patients.

    PubMed

    Chiewchengchol, Direkrit; Midgley, Angela; Sodsai, Pimpayao; Deekajorndech, Tawatchai; Hirankarn, Nattiya; Beresford, Michael W; Edwards, Steven W

    2015-01-01

    Juvenile systemic lupus erythematosus (JSLE) is one of the most common autoimmune diseases in children and can affect multiple organs and systems. The etiology remains unclear, and current management only suppresses rather than eliminates the disease. The pathogenesis is triggered by autoantigens that induce autoantibody production. Apoptotic neutrophils may be one source of autoantigens in JSLE, and increased numbers of apoptotic neutrophils in JSLE have been reported. This study aimed to determine if factor(s) in JSLE serum induce neutrophil apoptosis, to identify the most potent cytokine in delaying neutrophil apoptosis, and to investigate whether this cytokine can reverse the pro-apoptotic effects of JSLE serum. Blood neutrophils and sera were collected from JSLE patients, healthy children and adult controls. Neutrophils from healthy adult controls were incubated with 10 % serum from either JSLE patients or pediatric controls. Neutrophils from healthy adult controls were also incubated with 10 % JSLE serum with or without granulocyte-macrophage colony-stimulating factor (GM-CSF) supplementation. Neutrophil apoptosis was measured by flow cytometry (annexin-V/propidium iodide staining). Caspase-3, caspase-7 and caspase-8 protein expression was detected using Western blotting. Neutrophils incubated with JSLE sera had significantly increased apoptosis at 6 h compared to those incubated with control sera. Cleaved (active) forms of caspase-3, caspase-7 and caspase-8 were identified in neutrophils incubated with JSLE sera (that showed high rates of apoptosis) compared to control sera. GM-CSF had the most protective effect on neutrophil apoptosis, significantly preventing neutrophil apoptosis and caspase activation induced by JSLE serum. JSLE serum significantly induced neutrophil apoptosis in healthy adult neutrophils, activating the extrinsic pathway of apoptosis. The observation that GM-CSF prevents activation of apoptosis in response to JSLE serum should prompt

  7. Preventing Rejection

    MedlinePlus

    ... Drug Assistance Lifestyle Changes Back to Work or School Physical Changes Relationship Changes Pregnancy Precautions Fertility Labor & Delivery Breastfeeding Risks Cancer Types Risk Factors Prevention & Early Detection ...

  8. Leukocyte Elastase Induces Lung Epithelial Apoptosis via a PAR-1–, NF-κB–, and p53-Dependent Pathway

    PubMed Central

    Suzuki, Tomoko; Yamashita, Cory; Zemans, Rachel L.; Briones, Natalie; Van Linden, Annemie; Downey, Gregory P.

    2009-01-01

    Leukocyte elastase induces apoptosis of lung epithelial cells via alterations in mitochondrial permeability, but the signaling pathways regulating this response remain uncertain. Here we investigated the involvement of proteinase-activated receptor-1 (PAR-1), the transcription factor NF-κB, and the protooncogene p53 in this pathway. Elastase-induced apoptosis of lung epithelial cells correlated temporally with activation of NF-κB, phosphorylation, and nuclear translocation of p53, increased p53 up-regulated modulator of apoptosis (PUMA) expression, and mitochondrial translocation of Bax resulting in enhanced permeability. Elastase-induced apoptosis was also prevented by pharmacologic inhibitors of NF-κB and p53 and by short interfering RNA knockdown of PAR-1, p53, or PUMA. These inhibitors prevented elastase-induced PUMA expression, mitochondrial translocation of Bax, increased mitochondrial permeability, and attenuated apoptosis. NF-κB inhibitors also reduced p53 phosphorylation. We conclude that elastase-induced apoptosis of lung epithelial cells is mediated by a PAR-1–triggered pathway involving activation of NF-κB and p53, and a PUMA- and Bax-dependent increase in mitochondrial permeability leading to activation of distal caspases. Further, p53 contributes to elastase-induced apoptosis by both transcriptional and post-transcriptional mechanisms. PMID:19307610

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

    PubMed

    Kim, Jisun; Soh, Jaemog

    2009-07-10

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

  10. Social apoptosis in honey bee superorganisms.

    PubMed

    Page, Paul; Lin, Zheguang; Buawangpong, Ninat; Zheng, Huoqing; Hu, Fuliang; Neumann, Peter; Chantawannakul, Panuwan; Dietemann, Vincent

    2016-01-01

    Eusocial insect colonies form superorganisms, in which nestmates cooperate and use social immunity to combat parasites. However, social immunity may fail in case of emerging diseases. This is the case for the ectoparasitic mite Varroa destructor, which switched hosts from the Eastern honeybee, Apis cerana, to the Western honey bee, Apis mellifera, and currently is the greatest threat to A. mellifera apiculture globally. Here, we show that immature workers of the mite's original host, A. cerana, are more susceptible to V. destructor infestations than those of its new host, thereby enabling more efficient social immunity and contributing to colony survival. This counterintuitive result shows that susceptible individuals can foster superorganism survival, offering empirical support to theoretical arguments about the adaptive value of worker suicide in social insects. Altruistic suicide of immature bees constitutes a social analogue of apoptosis, as it prevents the spread of infections by sacrificing parts of the whole organism, and unveils a novel form of transgenerational social immunity in honey bees. Taking into account the key role of susceptible immature bees in social immunity will improve breeding efforts to mitigate the unsustainably high colony losses of Western honey bees due to V. destructor infestations worldwide. PMID:27264643

  11. Social apoptosis in honey bee superorganisms

    PubMed Central

    Page, Paul; Lin, Zheguang; Buawangpong, Ninat; Zheng, Huoqing; Hu, Fuliang; Neumann, Peter; Chantawannakul, Panuwan; Dietemann, Vincent

    2016-01-01

    Eusocial insect colonies form superorganisms, in which nestmates cooperate and use social immunity to combat parasites. However, social immunity may fail in case of emerging diseases. This is the case for the ectoparasitic mite Varroa destructor, which switched hosts from the Eastern honeybee, Apis cerana, to the Western honey bee, Apis mellifera, and currently is the greatest threat to A. mellifera apiculture globally. Here, we show that immature workers of the mite’s original host, A. cerana, are more susceptible to V. destructor infestations than those of its new host, thereby enabling more efficient social immunity and contributing to colony survival. This counterintuitive result shows that susceptible individuals can foster superorganism survival, offering empirical support to theoretical arguments about the adaptive value of worker suicide in social insects. Altruistic suicide of immature bees constitutes a social analogue of apoptosis, as it prevents the spread of infections by sacrificing parts of the whole organism, and unveils a novel form of transgenerational social immunity in honey bees. Taking into account the key role of susceptible immature bees in social immunity will improve breeding efforts to mitigate the unsustainably high colony losses of Western honey bees due to V. destructor infestations worldwide. PMID:27264643

  12. Preventative Maintenance.

    ERIC Educational Resources Information Center

    Migliorino, James

    Boards of education must be convinced that spending money up front for preventive maintenance will, in the long run, save districts' tax dollars. A good program of preventive maintenance can minimize disruption of service; reduce repair costs, energy consumption, and overtime; improve labor productivity and system equipment reliability; handle…

  13. Preventing Falls

    MedlinePlus

    ... from osteoporosis. Lower-body strength exercises and balance exercises can help you prevent falls and avoid the disability that may result from falling. Here are some fall prevention tips from Go4Life : l Have your eyes and hearing tested often. Always wear your glasses when you ...

  14. Mitophagy in TGEV infection counteracts oxidative stress and apoptosis.

    PubMed

    Zhu, Liqi; Mou, Chunxiao; Yang, Xing; Lin, Jian; Yang, Qian

    2016-05-10

    The intestinal epithelial cells contain a large number of mitochondria for persisting absorption and barrier function. Selective autophagy of mitochondria (mitophagy) plays an important role in the quality control of mitochondria and maintenance of cell homeostasis. Transmissible gastroenteritis virus (TGEV) is a porcine enteropathogenic coronavirus which induces malabsorption and lethal watery diarrhea in suckling piglets. The role of mitophagy in the pathological changes caused by TGEV infection is unclear. Here, we report that TGEV induces mitophagy to suppress oxidative stress and apoptosis induced by viral infection in porcine epithelial cells (IPEC-J2). We observe that TGEV infection induce mitochondrial injury, abnormal morphology, complete mitophagy, and without obvious apoptosis after TGEV infection. Meanwhile, TGEV also induces DJ-1 and some antioxidant genes upregulation to suppress oxidative stress induced by viral infection. Furthermore, silencing DJ-1 inhibit mitophagy and increase apoptosis after TGEV infection. In addition, we demonstrate for the first time that viral nucleocapsid protein (N) is located in mitochondria and mitophagosome during virus infection or be expressed alone. Those results provide a novel perspective for further improvement of prevention and treatment in TGEV infection. These results suggest that TGEV infection induce mitophagy to promote cell survival and possibly viral infection. PMID:27027356

  15. Apoptosis prediction via inhibition of AKT signaling pathway by neogrifolin

    PubMed Central

    Chen, Yang; Peng, Guo-Fang; Han, Xiang-Zhen; Wang, Wei; Zhang, Guo-Qiang; Li, Xiao

    2015-01-01

    Neogrifolin, a natural biologically active substance isolated from the edible bodies of the mushroom Albatrellus confluens, has been shown to possess several pharmacological properties. No studies were investigated against osteosarcoma cancer. Hence, in this study, we investigated the apoptosis-inducing effects and the mechanisms of neogrifolin on human osteosarcoma cells. Our results demonstrated that neogrifolin induced concentration- and time-dependent suppression of proliferation. Further, induction of apoptosis in U2OS and MG63 osteosarcoma cell lines were also observed. Neogrifolin induced the release of cytochrome c accompanied by activation of caspase-9, caspase-3 and cleavage of poly (ADP-ribose) polymerase (PARP). In addition, z-VAD-fmk, a universal inhibitor of caspases, prevented caspase-3 activation and PARP cleavage and inhibited neogrifolin-induced cell growth inhibition. Furthermore, neogrifolin treatment resulted in a reduction of phosphorylated AKT level, FOXO transcription factor, and glycogen synthase kinase 3 (GSK3). Knockdown of GSK3 with siRNA inhibited the apoptotic effects of neogrifolin. On the other hand, neogrifolin treatment also down-regulated the expression of the inhibitor of apoptosis protein (IAP) in both osteosarcoma cells. Collectively, our results suggested that neogrifolin is a potential candidate for osteosarcoma. PMID:25973001

  16. Calphostin-C induction of vascular smooth muscle cell apoptosis proceeds through phospholipase D and microtubule inhibition.

    PubMed

    Zheng, Xi-Long; Gui, Yu; Du, Guangwei; Frohman, Michael A; Peng, Dao-Quan

    2004-02-20

    Calphostin-C, a protein kinase C inhibitor, induces apoptosis of cultured vascular smooth muscle cells. However, the mechanisms are not completely defined. Because apoptosis of vascular smooth muscle cells is critical in several proliferating vascular diseases such as atherosclerosis and restenosis after angioplasty, we decided to investigate the mechanisms underlying the calphostin-C-induced apoptotic pathway. We show here that apoptosis is inhibited by the addition of exogenous phosphatidic acid, a metabolite of phospholipase D (PLD), and that calphostin-C inhibits completely the activities of both isoforms of PLD, PLD1 and PLD2. Overexpression of either PLD1 or PLD2 prevented the vascular smooth muscle cell apoptosis induced by serum withdrawal but not the calphostin-C-elicited apoptosis. These data suggest that PLDs have anti-apoptotic effects and that complete inhibition of PLD activity by calphostin-C induces smooth muscle cell apoptosis. We also report that calphostin-C induced microtubule disruption and that the addition of exogenous phosphatidic acid inhibits calphostin-C effects on microtubules, suggesting a role for PLD in stabilizing the microtubule network. Overexpressing PLD2 in Chinese hamster ovary cells phenocopies this result, providing strong support for the hypothesis. Finally, taxol, a microtubule stabilizer, not only inhibited the calphostin-C-induced microtubule disruption but also inhibited apoptosis. We therefore conclude that calphostin-C induces apoptosis of cultured vascular smooth muscle cells through inhibiting PLD activity and subsequent microtubule polymerization. PMID:14660552

  17. The regulation mechanism of apoptosis by visfatin in the mesenteric lymph nodes of LPS-treated rats.

    PubMed

    Xiao, Ke; Zhou, Ying; Yuan, Huai-Rui; Cui, Lu; Rehman, Zia Ur; Ansari, Abdur Rahman; Yang, Zhi; Peng, Ke-Mei; Song, Hui

    2016-09-01

    Visfatin is an adipocytokine displaying multiple functional properties, which plays a role in the regulation of cell apoptosis and inflammation by an as yet unidentified mechanism. The aim of the present study was to determine if visfatin is involved in apoptosis pathway induced by LPS in rat Mesenteric lymph nodes (MLNs). Experimental rats were divided into four groups and MLNs samples were collected from each group. The morphological changes of the MLNs were examined by histological imaging. CD68 and ENPP1 were detected with immunohistochemistry and Western Blot. Apoptosis was evaluated with TUNEL and Flow Cytometry, the mRNA levels of the apoptosis-related genes were detected by qRT-PCR, and the protein levels of the apoptotic-related factors were detected by western blot. The main results showed that visfatin could significantly increase the macrophages in MLNs and prevent cell apoptosis from LPS-induced mesenteric lymph nodes, activate apoptotic signaling pathways and regulate the mRNA levels of the apoptosis-related genes. Visfatin had a pro-apoptotic effect on normal MLNs, whereas it exerted an anti-apoptotic effect during LPS-induced cell apoptosis in rat MLNs. In short, visfatin plays a dual role in the apoptosis in rat MLNs, which is mediated by both the mitochondrial apoptotic pathway and the death-receptor apoptotic pathway. PMID:26857566

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

    SciTech Connect

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

    2008-07-18

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

  19. Suppression of Apoptosis by Basement Membrane Requires three-dimensional Tissue Organization and Withdrawal from the Cell Cycle

    SciTech Connect

    Boudreau, N.; Werb, Z.; Bissell, M.J.

    1995-12-28

    The basement membrane (BM) extracellular matrix induces differentiation and suppresses apoptosis in mammary epithelial cells, whereas cells lacking BM lose their differentiated phenotype and undergo apoptosis. Addition of purified BM components, which are known to induce {beta}-casein expression, did not prevent apoptosis, indicating that a more complex BM was necessary. A comparison of culture conditions where apoptosis would or would not occur allowed us to relate inhibition of apoptosis to a complete withdrawal from the cell cycle, which was observed only when cells acquired a three-dimensional alveolar structure in response to BM. In the absence of this morphology, both the G1 cyclin kinase inhibitor p21/WAF-I and positive proliferative signals including c-myc and cyclin Dl were expressed and the retinoblastoma protein (Rb) continued to be hyperphosphorylated. When we overexpressed either c-myc in quiescent cells or p21 when cells were still cycling, apoptosis was induced. In the absence of three-dimensional alveolar structures, mammary epithelial cells secrete a number of factors including transforming growth factor a and tenascin, which when added exogenously to quiescent cells induced expression of c-myc and interleukin-{beta}1-converting enzyme (ICE) mRNA and led to apoptosis. These experiments demonstrate that a correct tissue architecture is crucial for long-range homeostasis, suppression of apoptosis, and maintenance of differentiated phenotype.

  20. Optogenetic apoptosis: light-triggered cell death.

    PubMed

    Hughes, Robert M; Freeman, David J; Lamb, Kelsey N; Pollet, Rebecca M; Smith, Weston J; Lawrence, David S

    2015-10-01

    An optogenetic Bax has been designed that facilitates light-induced apoptosis. We demonstrate that mitochondrial recruitment of a genetically encoded light-responsive Bax results in the release of mitochondrial proteins, downstream caspase-3 cleavage, changes in cellular morphology, and ultimately cell death. Mutagenesis of a key phosphorylatable residue or modification of the C-terminus mitigates background (dark) levels of apoptosis that result from Bax overexpression. The mechanism of optogenetic Bax-mediated apoptosis was explored using a series of small molecules known to interfere with various steps in programmed cell death. Optogenetic Bax appears to form a mitochondrial apoptosis-induced channel analogous to that of endogenous Bax. PMID:26418181

  1. 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

  2. Sphingosine-1-Phosphate Protects Intestinal Epithelial Cells from Apoptosis Through the Akt Signaling Pathway

    PubMed Central

    Greenspon, Jose; Li, Ruiyun; Xiao, Lan; Rao, Jaladanki N.; Marasa, Bernard S.; Strauch, Eric D.; Wang, Jian-Ying; Turner, Douglas J.

    2009-01-01

    Objective The regulation of apoptosis of intestinal mucosal cells is important in maintenance of normal intestinal physiology. Summary Sphingosine-1-phosphate (S1P) has been shown to play a critical role in cellular protection to otherwise lethal stimuli in several nonintestinal tissues. Methods The current study determines whether S1P protected normal intestinal epithelial cells (IECs) from apoptosis and whether Akt activation was the central pathway for this effect. Results S1P demonstrated significantly reduced levels of apoptosis induced by tumor necrosis factor-alpha (TNF-α)/cycloheximide (CHX). S1P induced increased levels of phosphorylated Akt and increased Akt activity, but did not affect total amounts of Akt. This activation of Akt was associated with decreased levels of both caspase-3 protein levels and of caspase-3 activity. Inactivation of Akt by treatment with the PI3K chemical inhibitor LY294002 or by overexpression of the dominant negative mutant of Akt (DNMAkt) prevented the protective effect of S1P on apoptosis. Additionally, silencing of the S1P-1 receptor by specific siRNA demonstrated a lesser decrease in apoptosis to S1P exposure. Conclusion These results indicate that S1P protects intestinal epithelial cells from apoptosis via an Akt-dependent pathway. PMID:18654850

  3. Therapeutic Modulation of Apoptosis: Targeting the BCL-2 Family at the Interface of the Mitochondrial Membrane

    PubMed Central

    Nemec, Kathleen N.

    2008-01-01

    A vast portion of human disease results when the process of apoptosis is defective. Disorders resulting from inappropriate cell death range from autoimmune and neurodegenerative conditions to heart disease. Conversely, prevention of apoptosis is the hallmark of cancer and confounds the efficacy of cancer therapeutics. In the search for optimal targets that would enable the control of apoptosis, members of the BCL-2 family of anti- and pro-apoptotic factors have figured prominently. Development of BCL-2 antisense approaches, small molecules, and BH3 peptidomimetics has met with both success and failure. Success-because BCL-2 proteins play essential roles in apoptosis. Failure-because single targets for drug development have limited scope. By examining the activity of the BCL-2 proteins in relation to the mitochondrial landscape and drawing attention to the significant mitochondrial membrane alterations that ensue during apoptosis, we demonstrate the need for a broader based multi-disciplinary approach for the design of novel apoptosis-modulating compounds in the treatment of human disease. PMID:18972587

  4. Nonsteroidal antiinflammatory drugs cause apoptosis and induce cyclooxygenases in chicken embryo fibroblasts.

    PubMed Central

    Lu, X; Xie, W; Reed, D; Bradshaw, W S; Simmons, D L

    1995-01-01

    Programmed cell death (apoptosis) is an intrinsic part of organismal development and aging. Here we report that many nonsteroidal antiinflammatory drugs (NSAIDs) cause apoptosis when applied to v-src-transformed chicken embryo fibroblasts (CEFs). Cell death was characterized by morphological changes, the induction of tissue transglutaminase, and autodigestion of DNA. Dexamethasone, a repressor of cyclooxygenase (COX) 2, neither induced apoptosis nor altered the NSAID effect. Prostaglandin E2, the primary eicosanoid made by CEFs, also failed to inhibit apoptosis. Expression of the protooncogene bcl-2 is very low in CEFs and is not altered by NSAID treatment. In contrast, p20, a protein that may protect against apoptosis when fibroblasts enter G0 phase, was strongly repressed. The NSAID concentrations used here transiently inhibit COXs. Nevertheless, COX-1 and COX-2 mRNAs and COX-2 protein were induced. In some cell types, then, chronic NSAID treatment may lead to increased, rather than decreased, COX activity and, thus, exacerbate prostaglandin-mediated inflammatory effects. The COX-2 transcript is a partially spliced and nonfunctional form previously described. Thus, these findings suggest that COXs and their products play key roles in preventing apoptosis in CEFs and perhaps other cell types. Images Fig. 1 Fig. 2 Fig. 3 Fig. 5 Fig. 6 Fig. 7 Fig. 8 PMID:7644521

  5. Anesthetic isoflurane attenuates activated microglial cytokine-induced VSC4.1 motoneuronal apoptosis

    PubMed Central

    Yang, Shuangmei; Liu, Jun; Zhang, Xiaoran; Tian, Jianmin; Zuo, Zhichao; Liu, Jingjing; Yue, Xiuqin

    2016-01-01

    Isoflurane (ISO) exhibits neuroprotective effects against inflammation and apoptosis. However, the role of ISO in motoneuronal apoptosis induced by activated microglia remains poorly studied. We investigated the protective effects of ISO on the apoptosis of ventral spinal cord 4.1 (VSC4.1) motoneurons induced by lipopolysaccharide (LPS)-activated BV-2 microglia. Results indicated that ISO inhibited NF-κB activation and pro-inflammatory cytokine release in LPS-treated BV-2 microglia. Conditioned medium (CM) from activated BV-2 cells treated by ISO directly prevented VSC4.1 motoneurons from LPS-CM-induced neuronal apoptosis, as determined by the following: reductions in caspase-8, caspase-9, and caspase-3 activities; downregulation of pro-apoptotic procaspase-8, cleaved (cl)-caspase-8, procaspase-9, cl-caspase-9, caspase-3, cl-caspase-3, Bid, Bax, and cytochrome c expression; and upregulation of anti-apoptotic Bcl-2 expression in LPS-CM-cultured VSC4.1 motoneurons. Findings demonstrated that ISO inhibits BV-2 microglia activation and alleviates VSC4.1 motoneuronal apoptosis induced by microglial activation. These effects suggest that ISO can be used as an alternative agent for reducing neuronal apoptosis. PMID:27186270

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

    NASA Astrophysics Data System (ADS)

    Zhang, Heng; Wu, Shengnan

    2011-03-01

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

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

    SciTech Connect

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

    2011-08-15

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

  8. Vitamin B6 reduces hippocampal apoptosis in experimental pneumococcal meningitis

    PubMed Central

    2013-01-01

    Background Bacterial meningitis caused by Streptococcus pneumoniae leads to death in up to 30% of patients and leaves up to half of the survivors with neurological sequelae. The inflammatory host reaction initiates the induction of the kynurenine pathway and contributes to hippocampal apoptosis, a form of brain damage that is associated with learning and memory deficits in experimental paradigms. Vitamin B6 is an enzymatic cofactor in the kynurenine pathway and may thus limit the accumulation of neurotoxic metabolites and preserve the cellular energy status. The aim of this study in a pneumococcal meningitis model was to investigate the effect of vitamin B6 on hippocampal apoptosis by histomorphology, by transcriptomics and by measurement of cellular nicotine amide adenine dinucleotide content. Methods and results Eleven day old Wistar rats were infected with 1x106 cfu/ml of S. pneumoniae and randomized for treatment with vitamin B6 or saline as controls. Vitamin B6 led to a significant (p > 0.02) reduction of hippocampal apoptosis. According to functional annotation based clustering, vitamin B6 led to down-regulation of genes involved in processes of inflammatory response, while genes encoding for processes related to circadian rhythm, neuronal signaling and apoptotic cell death were mostly up-regulated. Conclusions Our results provide evidence that attenuation of apoptosis by vitamin B6 is multi-factorial including down-modulation of inflammation, up-regulation of the neuroprotective brain-derived neurotrophic factor and prevention of the exhaustion of cellular energy stores. The neuroprotective effect identifies vitamin B6 as a potential target for the development of strategies to attenuate brain injury in bacterial meningitis. PMID:23977941

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

    PubMed

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

    2013-04-01

    Cerebrolysin (Cere) is a peptidergic nootropic drug with neurotrophic properties which has been used to treat dementia and sequelae of stroke. Use of Cere prevents nuclear structural changes typical of apoptosis and significantly reduces the number of apoptotic cells after several apoptotic stimuli. Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) is a hereditary disease caused by mutations of the Notch3 gene encoding the Notch3 protein. Notch3 is involved in the regulation of apoptosis, modulating Fas-Ligand (Fas-L)- induced apoptosis. The aim of this study was to evaluate the in vitro protective effects of Cere against oxidative stress-induced apoptosis in cells from CADASIL patients. We used peripheral blood lymphocytes (PBLs) from 15 CADASIL patients (age range 34-70 years); 2-deoxy-D-ribose (dRib), a highly reducing sugar, was used as paradigm pro-apoptotic stimulus. Apoptosis was analyzed by flow cytometry and fluorescence microscopy. Administration of Cere to PBLs from CADASIL patients cultured under standard conditions had no effect on the percentage of apoptotic cells. Administration of Cere to PBLs cultured with dRib caused a significant decrease in apoptosis after 48 h of culture in only 5 patients, whereas in the other 10 patients, Cere treatment was not associated with any significant difference in the percentage of apoptosis. This result showed a protective effect of Cere against oxidative stress-induced apoptosis only in 30 % of the CADASIL patients, suggesting that the Notch3 gene probably does not influence the anti-apoptotic properties of Cere in vitro. PMID:22878905

  10. Nucleostemin Knockdown Sensitizes Hepatocellular Carcinoma Cells to Ultraviolet and Serum Starvation-Induced Apoptosis.

    PubMed

    Yuan, Fuwen; Cheng, Qian; Li, Guodong; Tong, Tanjun

    2015-01-01

    Nucleostemin (NS) is a GTP-binding protein that is predominantly expressed in embryonic and adult stem cells but not in terminally differentiated cells. NS plays an essential role in maintaining the continuous proliferation of stem cells and some types of cancer cells. However, the role of NS in hepatocellular carcinoma (HCC) remains unclear. Therefore, this study aimed to clarify the role of NS in HCC. First, we demonstrated high expression of NS in most HCC cell lines and liver cancer tissues. NS knockdown induced a severe decline in cell viability of MHCC97H cells as detected by MTT and cell proliferation assays. Next, we used ultraviolet (UV) and serum starvation-induced apoptosis models to investigate whether NS suppression or up-regulation affects HCC cell apoptosis. After UV treatment or serum starvation, apoptosis was strongly enhanced in MHCC97H and Bel7402 cells transfected with small interfering RNA against NS, whereas NS overexpression inhibited UV- and serum-induced apoptosis of HCC cells. Furthermore, after UV irradiation, inhibition of NS increased the expression of pro-apoptosis protein caspase 3 and decreased the expression of anti-apoptosis protein Bcl-2. A caspase 3 inhibitor could obviously prevent NS knockdown-induced apoptosis. In conclusion, our study demonstrated overexpression of NS in most HCC tissues compared with their matched surrounding tissues, and silencing NS promoted UV- and serum starvation-induced apoptosis of MHCC97H and Bel7402 cells. Therefore, the NS gene might be a potential therapeutic target of HCC. PMID:26517370

  11. Tocilizumab inhibits neuronal cell apoptosis and activates STAT3 in cerebral infarction rat model

    PubMed Central

    Wang, Shaojun; Zhou, Jun; Kang, Weijie; Dong, Zhaoni; Wang, Hezuo

    2016-01-01

    Cerebral infarction is a severe hypoxic ischemic necrosis with accelerated neuronal cell apoptosis in the brain. As a monoclonal antibody against interleukin 6, tocilizumab (TCZ) is widely used in immune diseases, whose function in cerebral infarction has not been studied. This study aims to reveal the role of TCZ in regulating neuronal cell apoptosis in cerebral infarction. The cerebral infarction rat model was constructed by middle cerebral artery occlusion and treated with TCZ. Cell apoptosis in hippocampus and cortex of the brain was examined with TUNEL method. Rat neuronal cells cultured in oxygen-glucose deprivation (OGD) conditions and treated with TCZ were used to compare cell viability and apoptosis. Apoptosis-related factors including B-cell lymphoma extra large (Bcl-xL) and Caspase 3, as well as the phosphorylated signal transducer and activator of transcription 3 (p-STAT3) in brain cortex were analyzed from the protein level. Results indicated that TCZ treatment could significantly prevent the promoted cell apoptosis caused by cerebral infarction or OGD (P < 0.05 or P < 0.01). In brain cortex of the rat model, TCZ up-regulated Bcl-xL and down-regulated Caspase 3, consistent with the inhibited cell apoptosis. It also promoted tyrosine 705 phosphorylation of STAT3, which might be the potential regulatory mechanism of TCZ in neuronal cells. This study provided evidence for the protective role of TCZ against neuronal cell apoptosis in cerebral infarction. Based on these fundamental data, TCZ is a promising option for treating cerebral infarction, but further investigations on related mechanisms are still necessary. PMID:26773188

  12. Cdc42 deficiency induces podocyte apoptosis by inhibiting the Nwasp/stress fibers/YAP pathway

    PubMed Central

    Huang, Z; Zhang, L; Chen, Y; Zhang, H; Zhang, Q; Li, R; Ma, J; Li, Z; Yu, C; Lai, Y; Lin, T; Zhao, X; Zhang, B; Ye, Z; Liu, S; Wang, W; Liang, X; Liao, R; Shi, W

    2016-01-01

    Podocyte apoptosis is a major mechanism that leads to proteinuria in many chronic kidney diseases. However, the concert mechanisms that cause podocyte apoptosis in these kidney diseases are not fully understood. The Rho family of small GTPases has been shown to be required in maintaining podocyte structure and function. Recent studies have indicated that podocyte-specific deletion of Cdc42 in vivo, but not of RhoA or Rac1, leads to congenital nephrotic syndrome and glomerulosclerosis. However, the underlying cellular events in podocyte controlled by Cdc42 remain unclear. Here, we assessed the cellular mechanisms by which Cdc42 regulates podocyte apoptosis. We found that the expression of Cdc42 and its activity were significantly decreased in high glucose-, lipopolysaccharide- or adriamycin-injured podocytes. Reduced Cdc42 expression in vitro and in vivo by small interfering RNA and selective Cdc42 inhibitor ML-141, respectively, caused podocyte apoptosis and proteinuria. Our results further demonstrated that insufficient Cdc42 or Nwasp, its downstream effector, could decrease the mRNA and protein expression of YAP, which had been regarded as an anti-apoptosis protein in podocyte. Moreover, our data indicated that the loss of stress fibers caused by Cdc42/Nwasp deficiency also decreased Yes-associated protein (YAP) mRNA and protein expression, and induced podocyte apoptosis. Podocyte apoptosis induced by Cdc42/Nwasp/stress fiber deficiency was significantly inhibited by overexpressing-active YAP. Thus, the Cdc42/Nwasp/stress fibers/YAP signal pathway may potentially play an important role in regulating podocyte apoptosis. Maintaining necessary Cdc42 would be one potent way to prevent proteinuria kidney diseases. PMID:26986510

  13. Nucleostemin Knockdown Sensitizes Hepatocellular Carcinoma Cells to Ultraviolet and Serum Starvation-Induced Apoptosis

    PubMed Central

    Li, Guodong; Tong, Tanjun

    2015-01-01

    Nucleostemin (NS) is a GTP-binding protein that is predominantly expressed in embryonic and adult stem cells but not in terminally differentiated cells. NS plays an essential role in maintaining the continuous proliferation of stem cells and some types of cancer cells. However, the role of NS in hepatocellular carcinoma (HCC) remains unclear. Therefore, this study aimed to clarify the role of NS in HCC. First, we demonstrated high expression of NS in most HCC cell lines and liver cancer tissues. NS knockdown induced a severe decline in cell viability of MHCC97H cells as detected by MTT and cell proliferation assays. Next, we used ultraviolet (UV) and serum starvation-induced apoptosis models to investigate whether NS suppression or up-regulation affects HCC cell apoptosis. After UV treatment or serum starvation, apoptosis was strongly enhanced in MHCC97H and Bel7402 cells transfected with small interfering RNA against NS, whereas NS overexpression inhibited UV- and serum-induced apoptosis of HCC cells. Furthermore, after UV irradiation, inhibition of NS increased the expression of pro-apoptosis protein caspase 3 and decreased the expression of anti-apoptosis protein Bcl-2. A caspase 3 inhibitor could obviously prevent NS knockdown-induced apoptosis. In conclusion, our study demonstrated overexpression of NS in most HCC tissues compared with their matched surrounding tissues, and silencing NS promoted UV- and serum starvation-induced apoptosis of MHCC97H and Bel7402 cells. Therefore, the NS gene might be a potential therapeutic target of HCC. PMID:26517370

  14. Preventing falls

    MedlinePlus

    ... worsened. Improving your vision will help reduce falls. Images ... for preventing falls in older people living in the community. Cochrane Database of Systematic Reviews 2009, Issue 2. Art. No.: ...

  15. Preventing Influenza

    MedlinePlus

    ... spread in respiratory droplets distributed by coughing and sneezing, they readily spread from person to person. Additionally, ... and nose with a tissue when coughing or sneezing, you may help prevent those around you from ...

  16. Dengue Prevention

    MedlinePlus

    ... Compartir This photograph shows a mother applying mosquito repellent to her child's skin in order to prevent ... the lights are on. To protect yourself, use repellent on your skin while indoors or out. When ...

  17. Unveiling a common mechanism of apoptosis in β-cells and neurons in Friedreich's ataxia.

    PubMed

    Igoillo-Esteve, Mariana; Gurgul-Convey, Ewa; Hu, Amélie; Romagueira Bichara Dos Santos, Laila; Abdulkarim, Baroj; Chintawar, Satyan; Marselli, Lorella; Marchetti, Piero; Jonas, Jean-Christophe; Eizirik, Décio L; Pandolfo, Massimo; Cnop, Miriam

    2015-04-15

    Friedreich's ataxia (FRDA) is a neurodegenerative disorder associated with cardiomyopathy and diabetes. Effective therapies for FRDA are an urgent unmet need; there are currently no options to prevent or treat this orphan disease. FRDA is caused by reduced expression of the mitochondrial protein frataxin. We have previously demonstrated that pancreatic β-cell dysfunction and death cause diabetes in FRDA. This is secondary to mitochondrial dysfunction and apoptosis but the underlying molecular mechanisms are not known. Here we show that β-cell demise in frataxin deficiency is the consequence of oxidative stress-mediated activation of the intrinsic pathway of apoptosis. The pro-apoptotic Bcl-2 family members Bad, DP5 and Bim are the key mediators of frataxin deficiency-induced β-cell death. Importantly, the intrinsic pathway of apoptosis is also activated in FRDA patients' induced pluripotent stem cell-derived neurons. Interestingly, cAMP induction normalizes mitochondrial oxidative status and fully prevents activation of the intrinsic pathway of apoptosis in frataxin-deficient β-cells and neurons. This preclinical study suggests that incretin analogs hold potential to prevent/delay both diabetes and neurodegeneration in FRDA. PMID:25552656

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

    PubMed

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

    2006-06-01

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

  19. Therapeutic approaches to the modulation of apoptosis.

    PubMed

    Murphy, Finbarr J; Seery, Liam T; Hayes, Ian

    2003-01-01

    The appreciation of the role of apoptosis in the vast majority of diseases affecting humans has revolutionized the discovery and development of drugs targeting inflammation and oncology. Novel therapeutic approaches to modulate disease by regulating apoptosis are currently being tested in preclinical and clinical settings. Enthusiasm for some of these therapies is reflected in the fact that they have received U.S. Food and Drug Administration approval in record time. Approaches include the traditional use of small molecules to target specific players in the apoptosis cascade. They also include radical new approaches such as using antisense molecules to inhibit production of the Bcl-2 protein or antibodies that ligate either death receptors, such as TRAIL (tumour necrosis factor-related apoptosis-inducing ligand), or the MHC (HLA-DR), resulting in the initiation of apoptosis of target cells. Antibodies targeting cell-specific antigens are being used in conjunction with radioactive isotopes to deliver a more specific chemotherapy, particularly in the case of B-cell lymphomas. Other therapies target mitochondria, a key organelle in the apoptosis cascade. This diverse range of therapies includes photodynamic therapy, retinoic acid and arsenic trioxide, all of which induce apoptosis by generating reactive oxygen species. As our understanding of apoptosis increases, further opportunities will arise for tailor-made therapies that will result in improved clinical outcome without the devastating side effects of current interventions. PMID:14585079

  20. 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

  1. CHCHD2 connects mitochondrial metabolism to apoptosis

    PubMed Central

    Liu, Yong; Zhang, Yanping

    2015-01-01

    As the powerhouse of cells and gatekeeper for apoptosis, mitochondria control life and death. CHCHD2, a mitochondrial protein previously known to regulate metabolism, has recently been identified as an apoptosis inhibitor. New data suggest a model in which CHCHD2 performs a prosurvival function by acting as both a reactive oxygen species scavenger and BCL-XL activator. PMID:27308501

  2. 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 ...

  3. Analysis of apoptosis in Caenorhabditis elegans.

    PubMed

    Lant, Benjamin; Derry, W Brent

    2014-05-01

    The nematode worm Caenorhabditis elegans has provided researchers with a wealth of information on the molecular mechanisms controlling programmed cell death (apoptosis). Its genetic tractability, optical clarity, and relatively short lifespan are key advantages for rapid assessment of apoptosis in vivo. The use of forward and reverse genetics methodology, coupled with in vivo imaging, has provided deep insights into how a multicellular organism orchestrates the self-destruction of specific cells during development and in response to exogenous stresses. Strains of C. elegans carrying mutations in the core elements of the apoptotic pathway, or in tissue-specific regulators of apoptosis, can be used for genetic analyses to reveal conserved mechanisms by which apoptosis is regulated in the somatic and reproductive (germline) tissue. Here we present an introduction to the study of apoptosis in C. elegans, including current techniques for visualization, analysis, and screening. PMID:24786497

  4. Induction of apoptosis by Shiga toxins

    PubMed Central

    Tesh, Vernon L

    2010-01-01

    Shiga toxins comprise a family of structurally and functionally related protein toxins expressed by Shigella dysenteriae serotype 1 and multiple serotypes of Escherichia coli. While the capacity of Shiga toxins to inhibit protein synthesis by catalytic inactivation of eukaryotic ribosomes has been well described, it is also apparent that Shiga toxins trigger apoptosis in many cell types. This review presents evidence that Shiga toxins induce apoptosis of epithelial, endothelial, leukocytic, lymphoid and neuronal cells. Apoptotic signaling pathways activated by the toxins are reviewed with an emphasis on signaling mechanisms that are shared among different cell types. Data suggesting that Shiga toxins induce apoptosis through the endoplasmic reticulum stress response and clinical evidence demonstrating apoptosis in humans infected with Shiga toxin-producing bacteria are briefly discussed. The potential for use of Shiga toxins to induce apoptosis in cancer cells is briefly reviewed. PMID:20210553

  5. 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

  6. Lymphocyte apoptosis in murine Pneumocystis pneumonia

    PubMed Central

    Shi, Xin; LeCapitaine, Nicole J; Rudner, Xiaowen L; Ruan, Sanbao; Shellito, Judd E

    2009-01-01

    Background Apoptosis of lymphocytes is important in the termination of an immune response to infection but has also been shown to have detrimental effects in animal models of systemic infection and sepsis. We sought to characterize lymphocyte apoptosis in an animal model of pneumonia due to Pneumocystis murina, an infection localized to the lungs. Methods Control mice and mice depleted of CD4+ lymphocytes were inoculated with Pneumocystis. Apoptosis of lung and spleen lymphocytes was assayed by flow cytometry and PCR assay of apoptotic proteins. Results In control mice, apoptosis of lung lymphocytes was maximal just after the infection was cleared from lung tissue and then declined. However, in CD4-depleted mice, apoptosis was also upregulated in recruited lymphocytes in spite of progressive infection. In splenic lymphocytes, apoptosis was observed early at 1 week after inoculation and then declined. Apoptosis of lung lymphocytes in control mice was associated with a decrease in mRNA for Bcl-2 and an increase in mRNA for Bim. In CD4-depleted mice, lavaged CD8+ cells did change intracellular Bcl-2 but showed increased mRNA for Bim. Conclusion Apoptosis of both pulmonary and extrapulmonary lymphocytes is part of the normal host response to Pneumocystis but is also triggered in CD4-deficient animals with progressive infection. In normal mice apoptosis of pulmonary lymphocytes may serve to terminate the immune response in lung tissue. Apoptosis of lung lymphocytes takes place via both the intrinsic and extrinsic apoptotic pathways and is associated with changes in both pro- and anti-apoptotic proteins. PMID:19558669

  7. Artesunate induces apoptosis via a ROS-independent and Bax-mediated intrinsic pathway in HepG2 cells.

    PubMed

    Qin, Guiqi; Wu, Liping; Liu, Hongyu; Pang, Yilin; Zhao, Chubiao; Wu, Shengnan; Wang, Xiaoping; Chen, Tongsheng

    2015-08-15

    This study aims to explore the detail molecular mechanism by which artesunate (ARS), an artemisinin derivative, induces apoptosis in HepG2 cells. ARS induced a loss of mitochondrial transmemberane potential (ΔΨm), phosphatidylserine (PS) externalization, as well as activations of Bax/Bak and caspases indicative of apoptosis induction. Silencing Bax but not Bak significantly inhibited ARS-induced apoptosis, demonstrating the key role of the Bax-mediated intrinsic pathway. Although ARS increased intracellular reactive oxygen species (ROS), ARS-induced apoptosis was neither prevented by pretreatment with ROS scavengers nor potentiated by pretreatment with l-buthionine-sulfoximine (BSO) that enhanced the ARS-induced intracellular ROS generation, demonstrating that ROS was not involved in ARS-induced apoptosis. In addition, ARS did not induce Bid translocation to mitochondria, and the cytotoxicity of ARS was not prevented by silencing Bim, Puma or Mcl-1, but was significantly enhanced by HA14-1 pretreatment, demonstrating that Bcl-2/-xl instead of Bid and Bim as well as Puma may be the upstream factor to regulate the Bax-mediated intrinsic pathway. Collectively, our data demonstrate that ARS induces ROS-independent apoptosis via the Bax-mediated intrinsic pathway in HepG2 cells. PMID:26163896

  8. Sapodilla plum (Achras sapota) induces apoptosis in cancer cell lines and inhibits tumor progression in mice.

    PubMed

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

    2014-01-01

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

  9. Hyperbaric oxygen therapy reduces apoptosis after spinal cord injury in rats

    PubMed Central

    Long, Ying; Liang, Fang; Gao, Chunjin; Li, Zhuo; Yang, Jing

    2014-01-01

    Hyperbaric oxygen therapy (HBOT) protects brain tissue from inflammatory injury by suppressing mitochondrial apoptotic pathways. However, its neuroprotective mechanism via anti-apoptosis in spinal cord injury (SCI) is still unclear. In our study, Male Sprague-Dawley rats were randomly divided into three groups: sham-operated (SH), SCI model, and SCI + HBOT. Rats in each group were randomly divided into four sub-groups in a time-dependent manner (1 day, 3 days, 7 days and 14 days after surgery). Expression of adaptor molecule apoptosis-associated speck-like protein (ASC) and caspase-3 was evaluated at the indicated time after injury. Our data showed that HBOT downregulated expression of ASC in SCI rats at the mRNA and protein levels. HBOT mitigated caspase-3 release in injured spinal cord tissue. We conclude that HBOT prevents inflammation apoptosis after SCI, likely through suppression of ASC and caspase-3. PMID:25550916

  10. Src kinase phosphorylates Caspase-8 on Tyr380: a novel mechanism of apoptosis suppression.

    PubMed

    Cursi, Silvia; Rufini, Alessandra; Stagni, Venturina; Condò, Ivano; Matafora, Vittoria; Bachi, Angela; Bonifazi, Antonio Paniccià; Coppola, Luigi; Superti-Furga, Giulio; Testi, Roberto; Barilà, Daniela

    2006-05-01

    We identified Caspase-8 as a new substrate for Src kinase. Phosphorylation occurs on Tyr380, situated in the linker region between the large and the small subunits of human Procaspase-8, and results in downregulation of Caspase-8 proapoptotic function. Src activation triggers Caspase-8 phosphorylation on Tyr380 and impairs Fas-induced apoptosis. Accordingly, Src failed to protect Caspase-8-defective human cells in which a Caspase-8-Y380F mutant is expressed from Fas-induced cell death. Remarkably, Src activation upon EGF-receptor stimulation triggers endogenous Caspase-8 phosphorylation and prevents Fas-induced apoptosis. Tyr380 is phosphorylated also in human colon cancers where Src is aberrantly activated. These data provide the first evidence for a direct role of tyrosine phosphorylation in the control of caspases and reveal a new mechanism through which tyrosine kinases inhibit apoptosis and participate in tumor progression. PMID:16619028

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

    PubMed Central

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

    2014-01-01

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

  12. Honey and Apoptosis in Human Gastric Mucosa

    PubMed Central

    Ghaffari, Aida; Somi, Mohammad H; Safaiyan, Abdolrasoul; Modaresi, Jabiz; Ostadrahimi, Alireza

    2012-01-01

    Background: Gastric cancer is the fourth most common malignancy in the world. Honey is a complex mixture of special biological active constituents. Honey possesses antioxidant and antitumor properties. Nutritional studies have indicated that consumption of honey modulates the risk of developing gastric cancer. On the other hand, apoptosis has been reported to play a decisive role in precancerous changes. Our chief study was conducted to assess the relationship between consumption of honey and apoptosis in human gastric mucosa. Method: This cross-sectional study was conducted on 98 subjects over 18 years old, referred to two hospitals in Tabriz, Iran. Subjects were undergone an upper gastrointestinal endoscopy, 62 subjects were finally enrolled. Honey consumption was assessed by a Food Frequency Questionnaire (FFQ) and apoptosis was detected by TUNEL technique. We tested polynomial curve to find the best fit between honey consumption and apoptosis. Results: A positive relation between honey consumption and apoptosis was found (P=0.024). Our results indicated that the final and the best fit curve was: apoptosis = 1.714+1.648(honey amount) - 0.533(honey amount)2 +1.833×10-5(honey amount)7. Conclusion: Honey consumption had positive effects on gastric cancer by inducing apoptosis in gastric mucosa. PMID:24688918

  13. Pre–B cell colony–enhancing factor inhibits neutrophil apoptosis in experimental inflammation and clinical sepsis

    PubMed Central

    Jia, Song Hui; Li, Yue; Parodo, Jean; Kapus, Andras; Fan, Lingzhi; Rotstein, Ori D.; Marshall, John C.

    2004-01-01

    Pre–B cell colony-enhancing factor (PBEF) is a highly conserved 52-kDa protein, originally identified as a growth factor for early stage B cells. We show here that PBEF is also upregulated in neutrophils by IL-1β and functions as a novel inhibitor of apoptosis in response to a variety of inflammatory stimuli. Induction of PBEF occurs 5–10 hours after LPS exposure. Prevention of PBEF translation with an antisense oligonucleotide completely abrogates the inhibitory effects of LPS, IL-1, GM-CSF, IL-8, and TNF-α on neutrophil apoptosis. Immunoreactive PBEF is detectable in culture supernatants from LPS-stimulated neutrophils, and a recombinant PBEF fusion protein inhibits neutrophil apoptosis. PBEF is also expressed in neutrophils from critically ill patients with sepsis in whom rates of apoptosis are profoundly delayed. Expression occurs at higher levels than those seen in experimental inflammation, and a PBEF antisense oligonucleotide significantly restores the normal kinetics of apoptosis in septic polymorphonuclear neutrophils. Inhibition of apoptosis by PBEF is associated with reduced activity of caspases-8 and -3, but not caspase-9. These data identify PBEF as a novel inflammatory cytokine that plays a requisite role in the delayed neutrophil apoptosis of clinical and experimental sepsis. PMID:15124023

  14. Responses of insect cells to baculovirus infection: protein synthesis shutdown and apoptosis.

    PubMed Central

    Du, X; Thiem, S M

    1997-01-01

    Protein synthesis is globally shut down at late times postinfection in the baculovirus Autographa californica M nuclear polyhedrosis virus (AcMNPV)-infected gypsy moth cell line Ld652Y. A single gene, hrf-1, from another baculovirus, Lymantria dispar M nucleopolyhedrovirus, is able to preclude protein synthesis shutdown and ensure production of AcMNPV progeny in Ld652Y cells (S. M. Thiem, X. Du, M. E. Quentin, and M. M. Berner, J. Virol. 70:2221-2229, 1996; X. Du and S. M. Thiem, Virology 227:420-430, 1997). AcMNPV contains a potent antiapoptotic gene, p35, and protein synthesis arrest was reported in apoptotic insect cells induced by infection with AcMNPV lacking p35. In exploring the function of host range factor 1 (HRF-1) and the possible connection between protein synthesis shutdown and apoptosis, a series of recombinant AcMNPVs with different complements of p35 and hrf-1 were employed in apoptosis and protein synthesis assays. We found that the apoptotic suppressor AcMNPV P35 was translated prior to protein synthesis shutdown and functioned to prevent apoptosis. HRF-1 prevented protein synthesis shutdown even when the cells were undergoing apoptosis, but HRF-1 could not functionally substitute for P35. The DNA synthesis inhibitor aphidicolin could block both apoptosis and protein synthesis shutdown in Ld652Y cells infected with p35 mutant AcMNPVs but not the protein synthesis shutdown in wild-type AcMNPV-infected Ld652Y cells. These data suggest that protein synthesis shutdown and apoptosis are separate responses of Ld652Y cells to AcMNPV infection and that P35 is involved in inducing a protein synthesis shutdown response in the absence of late viral gene expression in Ld652Y cells. A model was developed for these responses of Ld652Y cells to AcMNPV infection. PMID:9311875

  15. The Dpp/TGFβ-Dependent Corepressor Schnurri Protects Epithelial Cells from JNK-Induced Apoptosis in Drosophila Embryos

    PubMed Central

    Beira, Jorge V.; Springhorn, Alexander; Gunther, Stefan; Hufnagel, Lars; Pyrowolakis, Giorgos; Vincent, Jean-Paul

    2014-01-01

    Summary Jun N-terminal kinase (JNK) often mediates apoptosis in response to cellular stress. However, during normal development, JNK signaling controls a variety of live cell behaviors, such as during dorsal closure in Drosophila embryos. During this process, the latent proapoptotic activity of JNK becomes apparent following Dpp signaling suppression, which leads to JNK-dependent transcriptional activation of the proapoptotic gene reaper. Dpp signaling also protects cells from JNK-dependent apoptosis caused by epithelial disruption. We find that repression of reaper transcription by Dpp is mediated by Schnurri. Moreover, reporter gene analysis shows that a transcriptional regulatory module comprising AP-1 and Schnurri binding sites located upstream of reaper integrate the activities of JNK and Dpp. This arrangement allows JNK to control a migratory behavior without triggering apoptosis. Dpp plays a dual role during dorsal closure. It cooperates with JNK in stimulating cell migration and also prevents JNK from inducing apoptosis. PMID:25307481

  16. Poison Prevention

    MedlinePlus

    ... Word Shop AAP Find a Pediatrician Safety & Prevention ... Content Article Body Post the Poison Help number 1-800-222-1222 on the emergency list next to every phone in your home and in your cell phone. A toddler or preschooler who vomits may ...

  17. Preventing Tragedy.

    ERIC Educational Resources Information Center

    One Feather, Sandra

    2003-01-01

    The Navajo supervisor in the Office of Environmental Health in New Mexico identifies diseases and their risk factors, administers an injury prevention program, and ensures compliance with various health-related codes. She assists in the planning and direction of environmental health programs and public health education for local Navajo…

  18. Bullying Prevention

    ERIC Educational Res