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Apoptosis Pathway (apoptosi + pathway)
Kinds of Apoptosis Pathway Selected AbstractsSilencing of APAF-1 in B-CLL results in poor prognosis in the case of concomitant p53 mutationINTERNATIONAL JOURNAL OF CANCER, Issue 9 2006Isrid Sturm Abstract Apoptosis protease-activating factor 1 (APAF-1), a transcriptional target of p53, is a cytosolic adaptor protein that links the mitochondrial apoptosis pathway to the caspase cascade. Here, we aimed to study the impact of APAF-1 expression levels on cell death induced by anticancer drugs or ionizing irradiation (IR) and disease prognosis in B-type chronic lymphocytic leukemia (B-CLL) patients. Samples from 138 patients with B-CLL were investigated for APAF-1 expression and p53 mutations. The results were related to survival data, in vitro cytotoxicity of various cytotoxic drugs and IR and clinico-pathological data. Variable APAF-1 expression was observed in all investigated B-CLL samples. Reduction in APAF-1 expression was observed at both mRNA and protein level indicating transcriptional silencing whereas mutation of p53 or the immunoglobulin heavy chain variable genes (IgHV) had no impact on APAF-1 expression. Surprisingly, APAF-1 loss did not result in resistance to cytotoxic therapies. Likewise, APAF-1 downregulation on its own showed no impact on disease prognosis. Nevertheless, a poor prognosis was observed in patients with loss of APAF-1 expression and additional p53 mutation. Thus, loss of APAF-1 may become relevant when additional core apoptosis signaling components are disrupted. © 2005 Wiley-Liss, Inc. [source] Molecular analysis of the vagal motoneuronal degeneration after right vagotomyJOURNAL OF NEUROSCIENCE RESEARCH, Issue 3 2002Junfeng Ji Abstract The aim of this study was to investigate the vagal motoneuronal degeneration after right vagotomy using in situ hybridization, RT-PCR, and immunohistochemistry methods. The morphology of the vagal motoneurons in dorsal motor nucleus of the vagus nerve (DMV) and nucleus of ambiguus (NA) after right vagotomy was examined by using Nissl staing and TUNEL. The expression of inducible nitric oxide synthase (iNOS), bcl-2, bax, and caspase-3 in DMV and NA of rats after right vagotomy was studied. Additionally, the involvement of the N-methyl-D-aspartate (NMDA) receptor-calcium-neuronal nitric oxide synthase (nNOS) pathway in the vagal motoneuronal degeneration was addressed by double-immunolabeling analysis of nNOS with NMDAR1 and calbindin D28K in right-vagotomized rats. The neurons in right DMV and NA displayed a darkly stained, shrunken morphology at 1 day and 5 days following right vagotomy as shown by Nissl staining. Quantitative analysis revealed that, at 1 day and 5 days following right vagotomy, the number of neurons in right DMV, but not NA, was significantly reduced in comparison with that of control rats. Occasional TUNEL-positive neurons were detected in right DMV of rat at 1 day after right vagotomy. The expression of iNOS protein and mRNA was absent in DMV and NA of control rats. However, the iNOS mRNA expression was induced bilaterally in DMV and NA at 1 day postoperation and continued to be up-regulated until 5 days after vagotomy as shown by in situ hybridization. Immunohistochemistry analysis also showed the increased expression of iNOS in bilateral DMV and NA of vagotomized rats. RT-PCR analysis revealed the enhanced bcl-2 and reduced bax mRNA levels and subsequent up-regulation of both bcl-2 and bax mRNA in right sides of the vagotomized brainstems at 1 day and 5 days postoperation, respectively. In situ hybridization analysis confirmed the up-regulation of bcl-2 and bax mRNA in right DMV and NA of the rats at 5 days following operation. Immunohistochemistry analysis showed up-regulated Bcl-2 immunoreactivity and undetectable changes in Bax immunoreactivity in DMV and NA of rats at 1 day after vagotomy, whereas enhancement of both Bcl-2 and Bax immunoreactivity was observed at 5 days postoperation. In addition, the caspase-3 mRNA level was elevated ipsilaterally in DMV and NA at 1 day and 5 days following right vagotomy. Double-immunofluorescence analysis showed complete colocalization of nNOS with NMDAR1 and with calbindin in ipsilateral DMV and NA at 10 days following right vagotomy. This study suggests that the signal pathway for NMDAR1-calcium-nNOS and the up-regulation of iNOS in DMV and NA may be involved in the vagal motor neurodgeneration after right vagotomy. Furthermore, our results imply that the apoptosis pathway mediated by Bcl-2, Bax, and caspase-3 may be activated in vagal motoneurons after right vagotomy. © 2002 Wiley-Liss, Inc. [source] The role of the intrinsic apoptosis pathway in platelet life and deathJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 2009B. T. KILE Summary., In recent years, it has become increasingly apparent that the production of platelets and their subsequent life span in the circulation are regulated, at least in part, by apoptotic mechanisms. There is also evidence implicating the apoptotic machinery in the regulation of platelet functional responses. This review examines the role of the intrinsic apoptosis pathway, regulated by the Bcl-2 family of proteins, in platelet biology. [source] Characteristics of dengue virus-infected peripheral blood mononuclear cell death that correlates with the severity of illnessMICROBIOLOGY AND IMMUNOLOGY, Issue 8 2009Yanin Jaiyen ABSTRACT The pathogenic mechanism of the severe form of dengue is complicated. Recent reports indicate that apoptotic death of various tissues or organs may be associated with vascular leakage, and ultimately leads to the death of DENV-infected patients. In the present study, we provide additional evidence supporting the detrimental role of apoptosis in DENV infection. A comparison of the rate of apoptosis in PBMCs isolated from patients suffering DF, a mild form of the disease, and the rate in patients with DHF, a life-threatening disease, revealed that PBMCs from DHF patients underwent apoptosis at a significantly higher rate than those suffering from DF alone. This suggests that the severity of natural DENV infection correlates with PBMC apoptosis. In addition, this cell death was induced not only by DENV itself, but also by the apoptotic activities of pro-inflammatory cytokines, such as TNF-,, and IL-1,, that were upregulated in DHF patients. The death of these mononuclear cells that function in an innate immune system may explain the higher viral load in DHF patients than in DF patients. Interestingly, a gene expression profile pattern elucidated that apoptosis occurring during natural DENV infection involved mainly the extrinsic apoptosis pathway, which is mediated via both caspase-dependent and caspase-independent mechanisms. In conclusion, our data highlight the adverse effect of apoptosis induced by DENV and by pro-inflammatory cytokines during natural DENV infection. [source] 1,1-bis(3,-indolyl)-1-(p -methoxyphenyl)methane activates Nur77-independent proapoptotic responses in colon cancer cellsMOLECULAR CARCINOGENESIS, Issue 4 2008Sung Dae Cho Abstract 1,1-Bis(3,-indolyl)-1-(p -methoxyphenyl)methane (DIM-C-pPhOCH3) is a methylene-substituted diindolylmethane (C-DIM) analog that activates the orphan receptor nerve growth factor-induced-B, (NGFI-B,, Nur77). RNA interference studies with small inhibitory RNA for Nur77 demonstrate that DIM-C-pPhOCH3 induces Nur77-dependent and -independent apoptosis, and this study has focused on delineating the Nur77-independent proapoptotic pathways induced by the C-DIM analog. DIM-C-pPhOCH3 induced caspase-dependent apoptosis in RKO colon cancer cells through decreased mitochondrial membrane potential which is accompanied by increased mitochondrial bax/bcl-2 ratios and release of cytochrome c into the cytosol. DIM-C-pPhOCH3 also induced phosphatidylinositol-3-kinase-dependent activation of early growth response gene-1 which, in turn, induced expression of the proapoptotic nonsteroidal anti-inflammatory drug-activated gene-1 (NAG1) in RKO and SW480 colon cancer cells. Moreover, DIM-C-pPhOCH3 also induced NAG-1 expression in colon tumors in athymic nude mice bearing RKO cells as xenografts. DIM-C-pPhOCH3 also activated the extrinsic apoptosis pathway through increased phosphorylation of c- jun N-terminal kinase which, in turn, activated C/EBP homologous transcription factor (CHOP) and death receptor 5 (DR5). Thus, the effectiveness of DIM-C-pPhOCH3 as a tumor growth inhibitor is through activation of Nur77-dependent and -independent pathways. © 2007 Wiley-Liss, Inc. [source] Relevance of caspase activity during apoptosis in pubertal rat spermatogenesisMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 5 2008Veronica A. Codelia Abstract Caspases are a family of cysteine-proteases, activated upon several different stimuli, which execute apoptosis in many cell death models. Previous work of our group has shown rats have the highest rate of apoptosis during the first wave of spermatogenesis (between 20 and 25 days after birth), as evaluated by TUNEL and caspase activity. However, the hierarchical order of caspase activation and the relevance of each caspase during germ cell apoptosis are not clear. Thus, the goal of this work is to take a pharmacological approach to dissect the apoptosis pathway of caspase activation. Results showed that intratesticular injection of a caspase-8 inhibitor (z-IETD-fmk), or a pan-caspase inhibitor (z-VAD- fmk), significantly decreased the cleavage of p115 and PARP, two endogenous substrates of caspases, in 22-day-old rats. Additionally, these inhibitors promoted a significant reduction in the number of apoptotic germ cells. On the other hand, intratesticular injection of two different inhibitors of the intrinsic pathway (z-LEHD-fmk and minocycline) did not have any effect upon caspase substrates cleavage (p115 and PARP) or the number of apoptotic germ cells. Therefore, we conclude that the extrinsic pathway of apoptosis plays an important role in physiological germ cell apoptosis during the first round of spermatogenesis in the rat. Mol. Reprod. Dev. 75: 881,889, 2008. © 2007 Wiley-Liss, Inc. [source] Molecular targeted therapies for diffuse large B-cell lymphoma based on apoptosis profiles,THE JOURNAL OF PATHOLOGY, Issue 5 2010Saskia AGM Cillessen Abstract Diffuse large B-cell lymphoma (DLBCL) is the most common type of adult non-Hodgkin lymphoma and is treated with chemotherapy in combination with rituximab. Despite this aggressive therapy, the disease is fatal in 30,40% of patients. Inhibition of the apoptosis signalling pathways is strongly related to response to chemotherapy and eventual clinical outcome. In order to survive, lymphoma cells depend on disruption of the apoptosis pathway by mutations in apoptosis inducing genes or by continuous expression of anti-apoptotic proteins. The development of molecules targeting these apoptosis inhibitors provides a very promising opportunity to specifically target tumour cells without toxicity to non-malignant cells in DLBCL patients. Sensitivity for most of these antagonists can be predicted based on biological markers, suggesting the possibility of pre-defining patients who will most likely benefit from these targeted therapies. Experimental therapies aimed at restoring the upstream apoptosis pathway or targeting apoptosis inhibitors are currently being tested in clinical trials and are expected to be effective particularly in chemotherapy-refractory DLBCL, providing hope for patients who are refractory to current therapies. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [source] Apoptosis regulators Fau and Bcl-G are down-regulated in prostate cancerTHE PROSTATE, Issue 14 2010Mark R. Pickard Abstract BACKGROUND The molecular control of cell death through apoptosis is compromised in prostate cancer cells, resulting in inappropriate cell survival and resistance to cytotoxic therapy. Reduced expression of the functionally connected apoptosis-regulators and candidate tumor suppressors Fau and Bcl-G has recently been implicated in oncogenesis in other tissues. The present study examines the hypothesis that reduced expression of these genes may be involved in prostate cancer. METHODS Fau and Bcl-G mRNA levels were determined by real time RT-PCR in two independent prostate tissue collections. In experiments in vitro, Fau and Bcl-G levels in prostate cancer cell lines were reduced using RNA interference and the effects on sensitivity to UVC irradiation were determined. RESULTS Fau and Bcl-G mRNA levels were both lower in prostate cancer tissue than in normal prostate and Benign Prostate Hyperplasia. Active down-regulation of Fau and Bcl-G expression in vitro resulted in decreased sensitivity to UVC-induced cytotoxicity. Simultaneous down-regulation of Fau and Bcl-G produced a decrease in sensitivity which was similar to either gene alone. CONCLUSIONS Fau and Bcl-G mRNA levels are both decreased in prostate cancer. In prostate cancer cell lines in vitro such down-regulation results in reduced sensitivity to UVC-induced cytotoxicity, consistent with the putative roles of these genes as candidate prostate tumor suppressors. The absence of an additive effect when Fau and Bcl-G were down-regulated simultaneously is consistent with the two genes acting in the same apoptosis pathway, for example, with the pro-apoptotic effects of Fau being mediated through modulation of Bcl-G. Prostate 70: 1513,1523, 2010. © 2010 Wiley-Liss, Inc. [source] Immunohistochemical analysis of phospho-BAD protein and mutational analysis of BAD gene in gastric carcinomas,APMIS, Issue 8 2007EUN GOO JEONG Mounting evidence indicates that deregulation of apoptosis contributes to the development of human cancers. BAD, a proapoptotic Bcl-2 family protein, regulates the intrinsic apoptosis pathway. The aim of this study was to explore whether alterations of phospho-BAD (p-BAD) protein that antagonizes apoptosis function of BAD and mutation of BAD gene are characteristics of human gastric cancers. We analyzed expression of p-BAD in 60 gastric adenocarcinomas by immunohistochemistry. Also, we analyzed BAD gene for detection of somatic mutations by single-strand conformation polymorphism (SSCP) assay. p-BAD expression was detected well in normal gastric mucosal epithelial cells, whereas it was detected in only 51% (31 of the 60) of the cancers. There was no somatic mutation of BAD gene in the 60 gastric cancer samples. The decreased expression of p-BAD in malignant gastric epithelial cells compared to normal mucosal epithelial cells suggested that loss of p-BAD expression may play a role in gastric tumorigenesis. The data also suggest that BAD mutation may not be a direct target of inactivation in gastric tumorigenesis. [source] The effect of Bcl-2, YAMA, and XIAP over-expression on apoptosis and adenovirus production in HEK293 cell lineBIOTECHNOLOGY & BIOENGINEERING, Issue 4 2009Kalbinder Singh Sandhu Abstract Many viruses induce cell death and lysis as part of their replication and dissemination strategy, and in many cases features of apoptosis are observed. Attempts have been made to further increase productivity by prolonging cell survival via the over-expression of anti-apoptotic genes. Here, we extend the study to investigate the association between virus replication and apoptosis, pertinent to large-scale vector production for gene therapy. Infection of an HEK293 cell line with a replication defective type-5-adenovirus expressing a GFP reporter (Ad5GFP) resulted in rapid decline in viability associated with increased virus titer. The over-expression of bcl-2 resulted in improved cell resistance to apoptosis and prolonged culture duration, but reduced virus specific and total productivity. In contrast, the over-expression of pro-caspase-3 (Yama/CPP32/apopain) resulted in reduced cell survival but increased virus productivity. The treatment of infected cells with caspase inhibitors support the preposition that caspase-3 dependent apoptosis, and to a lesser degree caspase-9 dependent apoptosis, represent important steps in virus production, thus implicating the intrinsic apoptosis pathway in the production of adenovirus from HEK293 cells. The suppression of apoptosis by the over-expression of XIAP (inhibitors of caspase family cell death proteases) further shows that caspase-mediated activation plays an important role in virus infection and maturation. Biotechnol. Bioeng. 2009; 104: 752,765 © 2009 Wiley Periodicals, Inc. [source] Rapamycin inhibits lung metastasis of B16 melanoma cells through down-regulating alphav integrin expression and up-regulating apoptosis signalingCANCER SCIENCE, Issue 2 2010Zhuoshun Yang Currently available data indicate the potential application of rapamycin and its analogues in the clinic as anticancer therapeutic agents through inhibiting tumor cell growth and tumor angiogenesis. However, whether rapamycin can directly suppress tumor metastasis remains unclear. In the present study, we demonstrated that rapamycin treatment results in reduced formation of metastatic nodules in the lung by B16 cells. This is due to two mechanisms. First, the expression of ,v integrin is down-regulated by rapamycin treatment, and subsequently, the phosphorylation of focal adhesion kinase (FAK) is reduced. Second, rapamycin promotes apoptosis by up-regulating the proapoptotic molecules Bid and Bax and down-regulating Bcl-xL. Blocking the apoptosis pathway by pan-caspase inhibitor zVAD partially reversed the suppression of rapamycin in B16 metastasis. Interestingly, rapamycin up-regulates Bax and Bid in B16 cells via the S6K1 pathway and down-regulates the expression of ,v integrin via other pathway(s). In addition, our data showed that autophagy was not involved in the mechanisms of rapamycin-mediated metastasis suppression. Our findings demonstrate a potential anti-metastatic effect of rapamycin via down-regulating ,v integrin expression and up-regulating apoptosis signaling, suggesting that rapamycin might be worthy of clinical evaluation as an antimetastatic agent. (Cancer Sci 2009) [source] Probing the ,-Helical Structural Stability of Stapled p53 Peptides: Molecular Dynamics Simulations and AnalysisCHEMICAL BIOLOGY & DRUG DESIGN, Issue 4 2010Zuojun Guo Reactivation of the p53 cell apoptosis pathway through inhibition of the p53-hDM2 interaction is a viable approach to suppress tumor growth in many human cancers and stabilization of the helical structure of synthetic p53 analogs via a hydrocarbon cross-link (staple) has been found to lead to increased potency and inhibition of protein,protein binding (J. Am. Chem. Soc. 129: 5298). However, details of the structure and dynamic stability of the stapled peptides are not well understood. Here, we use extensive all-atom molecular dynamics simulations to study a series of stapled ,-helical peptides over a range of temperatures in solution. The peptides are found to exhibit substantial variations in predicted ,-helical propensities that are in good agreement with the experimental observations. In addition, we find significant variation in local structural flexibility of the peptides with the position of the linker, which appears to be more closely related to the observed differences in activity than the absolute ,-helical stability. These simulations provide new insights into the design of ,-helical stapled peptides and the development of potent inhibitors of ,-helical protein,protein interfaces. [source] Association of polymorphisms in CASP10 and CASP8 with FEV1/FVC and bronchial hyperresponsiveness in ethnically diverse asthmaticsCLINICAL & EXPERIMENTAL ALLERGY, Issue 11 2008Alicia K. Smith Summary Background Several chromosomal regions have been identified using family-based linkage analysis to contain genes contributing to the development of asthma and allergic disorders. One of these regions, chromosome 2q32-q33, contains a gene cluster containing CFLAR, CASP10 and CASP8. These genes regulate the extrinsic apoptosis pathway utilized by several types of immune and structural cells that have been implicated in the pathogenesis of asthma. Objective To assess the role of genetic variation in CFLAR, CASP10 and CASP8 in asthma and related phenotypes in individuals of diverse ethnic backgrounds. Methods We tested 26 single nucleotide polymorphisms (SNPs) in the CFLAR, CASP10 and CASP8 gene cluster for association with asthma and related phenotypes in African-American, non-Hispanic whites, and Hispanic case,control populations (cases, N=517, controls, N=644). Results Five CASP10 SNPS were associated with forced expiratory volume in 1 s (FEV1)/forced expiration volume capacity (FVC) in the African-American subjects with asthma (P=0.0009,0.047). Nine SNPs, seven in CASP10 and two in CASP8, were also associated with the degree of bronchial hyperresponsiveness (BHR) (as determined by PC20) in race-specific analysis, predominately in the Non-Hispanic white cases. Two SNPs, rs6750157 in CASP10 and rs1045485 in CASP8 were modestly associated with asthma in the African-American (P=0.025) and Hispanic (P=0.033) populations, respectively. Conclusion These data suggest a role for CASP10 as a potential modifier of the asthma phenotype, specifically with measures of airway obstruction and BHR. [source] Hypoxia-inducible factor-1, in non small cell lung cancer: Relation to growth factor, protease and apoptosis pathwaysINTERNATIONAL JOURNAL OF CANCER, Issue 1 2004Daniel E.B. Swinson Abstract Hypoxia-inducible factor (HIF)-1, is the regulatory subunit of HIF-1 that is stabilized under hypoxic conditions. Under different circumstances, HIF-1, may promote both tumorigenesis and apoptosis. There is conflicting data on the importance of HIF-1, as a prognostic factor. This study evaluated HIF-1, expression in 172 consecutive patients with stage I,IIIA non small cell lung cancer (NSCLC) using standard immunohistochemical techniques. The extent of HIF-1, nuclear immunostaining was determined using light microscopy and the results were analyzed using the median (5%) as a low cut-point and 60% as a high positive cut-point. Using the low cut-point, positive associations were found with epidermal growth factor receptor (EGFR; p = 0.01), matrix metalloproteinase (MMP)-9 (p = 0.003), membranous (p < 0.001) and perinuclear (p = 0.004) carbonic anhydrase (CA) IX, p53 (p = 0.008), T-stage (p = 0.042), tumor necrosis (TN; p < 0.001) and squamous histology (p < 0.001). No significant association was found with Bcl-2 or either N- or overall TMN stage or prognosis. When the high positive cut-point was used, HIF-1, was associated with a poor prognosis (p = 0.034). In conclusion, the associations with EGFR, MMP-9, p53 and CA IX suggest that these factors may either regulate or be regulated by HIF-1,. The association with TN and squamous-type histology, which is relatively more necrotic than other NSCLC types, reflects the role of hypoxia in the regulation of HIF-1,. The prognostic data may reflect a change in the behavior of HIF-1, in increasingly hypoxic environments. © 2004 Wiley-Liss, Inc. [source] Exploring the priming mechanism of liver regeneration: proteins and protein complexesPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 8 2009Xinyu Deng Abstract The liver has the ability to restore its functional capacity following injury or resection and the priming of liver regeneration is a complex process that has not been completely elucidated. In the current research, to further reveal the priming mechanism of liver regeneration, hepatocyte total protein and hepatocyte cytosol of the rats at 4,h after 2/3 partial hepatectomy (PHx) were studied, respectively, by 2-DE and 2-D blue native gel electrophoresis. Seventeen unique differential proteins were identified in hepatocyte total protein samples. Nine differential protein complexes containing 41 protein components were identified in hepatocyte cytosol samples. For the first time, at the priming stage of liver regeneration, the variations of serine protease inhibitor 2c, sulfite oxidase and valosin-containing protein (VCP) were presented and validated by Western blotting, and the VCP complex was further validated by antibody super-shift experiments. The current results suggested that at 4,h after PHx, VCP complex was down-regulated in hepatocyte cytosol, apoptosis pathways were inhibited, nuclear factor-,B and interleukin 6 pathways worked together and triggered the liver regeneration. [source] | |||||||||||||