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Sample records for apoptotic damage role

  1. Protective role of malvidin-3-glucoside on peroxynitrite-induced damage in endothelial cells by counteracting reactive species formation and apoptotic mitochondrial pathway.

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    Paixão, Joana; Dinis, Teresa C P; Almeida, Leonor M

    2012-01-01

    The health-promoted benefits of anthocyanins, including vascular protective effects and antiatherogenic properties, have now been recognized, but the involved molecular mechanisms have not been well elucidated. Following our previous work on cytoprotective mechanisms of some anthocyanins against apoptosis triggered by peroxynitrite in endothelial cells, here we investigated the protective role of malvidin-3-glucoside, a major dietary anthocyanin, on such deleterious process, by exploring the interference on cellular reactive species formation and on apoptotic mitochondrial pathway. Preincubation of cells with 25 μM malvidin-3-glucoside protected efficiently endothelial cells from peroxynitrite-promoted apoptotic death, an effect which may be partially mediated by its ability to decrease the formation of reactive species after cell aggression, as assessed by the dichlorodihydrofluorescein diacetate assay and by carbonyl groups formation. Moreover, malvidin-3-glucoside inhibited mitochondrial apoptotic signaling pathways induced by peroxynitrite, by counteracting mitochondrial membrane depolarization, the activation of caspase-3 and -9, and the increase in the expression of the proapoptotic Bax protein. Altogether, our data expands our knowledge about the molecular mechanisms underlying the vascular protection afforded by malvidin-3-glucoside, and anthocyanins in general, in the context of prevention of endothelial dysfunction and atherosclerosis.

  2. The Opa1-Dependent Mitochondrial Cristae Remodeling Pathway Controls Atrophic, Apoptotic, and Ischemic Tissue Damage

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    Varanita, Tatiana; Soriano, Maria Eugenia; Romanello, Vanina; Zaglia, Tania; Quintana-Cabrera, Rubén; Semenzato, Martina; Menabò, Roberta; Costa, Veronica; Civiletto, Gabriele; Pesce, Paola; Viscomi, Carlo; Zeviani, Massimo; Di Lisa, Fabio; Mongillo, Marco; Sandri, Marco; Scorrano, Luca

    2015-01-01

    Summary Mitochondrial morphological and ultrastructural changes occur during apoptosis and autophagy, but whether they are relevant in vivo for tissue response to damage is unclear. Here we investigate the role of the optic atrophy 1 (OPA1)-dependent cristae remodeling pathway in vivo and provide evidence that it regulates the response of multiple tissues to apoptotic, necrotic, and atrophic stimuli. Genetic inhibition of the cristae remodeling pathway in vivo does not affect development, but protects mice from denervation-induced muscular atrophy, ischemic heart and brain damage, as well as hepatocellular apoptosis. Mechanistically, OPA1-dependent mitochondrial cristae stabilization increases mitochondrial respiratory efficiency and blunts mitochondrial dysfunction, cytochrome c release, and reactive oxygen species production. Our results indicate that the OPA1-dependent cristae remodeling pathway is a fundamental, targetable determinant of tissue damage in vivo. PMID:26039448

  3. Role of apoptotic hepatocytes in HCV dissemination: regulation by acetaldehyde.

    Science.gov (United States)

    Ganesan, Murali; Natarajan, Sathish Kumar; Zhang, Jinjin; Mott, Justin L; Poluektova, Larisa I; McVicker, Benita L; Kharbanda, Kusum K; Tuma, Dean J; Osna, Natalia A

    2016-06-01

    Alcohol consumption exacerbates hepatitis C virus (HCV) pathogenesis and promotes disease progression, although the mechanisms are not quite clear. We have previously observed that acetaldehyde (Ach) continuously produced by the acetaldehyde-generating system (AGS), temporarily enhanced HCV RNA levels, followed by a decrease to normal or lower levels, which corresponded to apoptosis induction. Here, we studied whether Ach-induced apoptosis caused depletion of HCV-infected cells and what role apoptotic bodies (AB) play in HCV-alcohol crosstalk. In liver cells exposed to AGS, we observed the induction of miR-122 and miR-34a. As miR-34a has been associated with apoptotic signaling and miR-122 with HCV replication, these findings may suggest that cells with intensive viral replication undergo apoptosis. Furthermore, when AGS-induced apoptosis was blocked by a pan-caspase inhibitor, the expression of HCV RNA was not changed. AB from HCV-infected cells contained HCV core protein and the assembled HCV particle that infect intact hepatocytes, thereby promoting the spread of infection. In addition, AB are captured by macrophages to switch their cytokine profile to the proinflammatory one. Macrophages exposed to HCV(+) AB expressed more IL-1β, IL-18, IL-6, and IL-10 mRNAs compared with those exposed to HCV(-) AB. The generation of AB from AGS-treated HCV-infected cells even enhanced the induction of aforementioned cytokines. We conclude that HCV and alcohol metabolites trigger the formation of AB containing HCV particles. The consequent spread of HCV to neighboring hepatocytes via infected AB, as well as the induction of liver inflammation by AB-mediated macrophage activation potentially exacerbate the HCV infection course by alcohol and worsen disease progression.

  4. Apoptotic susceptibility to DNA damage of pluripotent stem cells facilitates pharmacologic purging of teratoma risk.

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    Smith, Alyson J; Nelson, Natalie G; Oommen, Saji; Hartjes, Katherine A; Folmes, Clifford D; Terzic, Andre; Nelson, Timothy J

    2012-10-01

    Pluripotent stem cells have been the focus of bioengineering efforts designed to generate regenerative products, yet harnessing therapeutic capacity while minimizing risk of dysregulated growth remains a challenge. The risk of residual undifferentiated stem cells within a differentiated progenitor population requires a targeted approach to eliminate contaminating cells prior to delivery. In this study we aimed to validate a toxicity strategy that could selectively purge pluripotent stem cells in response to DNA damage and avoid risk of uncontrolled cell growth upon transplantation. Compared with somatic cell types, embryonic stem cells and induced pluripotent stem cells displayed hypersensitivity to apoptotic induction by genotoxic agents. Notably, hypersensitivity in pluripotent stem cells was stage-specific and consistently lost upon in vitro differentiation, with the mean half-maximal inhibitory concentration increasing nearly 2 orders of magnitude with tissue specification. Quantitative polymerase chain reaction and Western blotting demonstrated that the innate response was mediated through upregulation of the BH3-only protein Puma in both natural and induced pluripotent stem cells. Pretreatment with genotoxic etoposide purged hypersensitive pluripotent stem cells to yield a progenitor population refractory to teratoma formation upon transplantation. Collectively, this study exploits a hypersensitive apoptotic response to DNA damage within pluripotent stem cells to decrease risk of dysregulated growth and augment the safety profile of transplant-ready, bioengineered progenitor cells.

  5. Chronic hepatitis B serum promotes apoptotic damage in human renal tubular cells

    Institute of Scientific and Technical Information of China (English)

    Cun-Liang Deng; Xin-Wen Song; Hai-Jun Liang; Chen Feng; Yun-Jian Sheng; Ming-Yong Wang

    2006-01-01

    AIM: To investigate the effect of the serum of patients with chronic hepatitis B (CHB) on apoptosis of renal tubular epithelial cells in vitro and to study the role of hepatitis B virus (HBV) and transforming growth factor-β1 (TGF-β1) in the pathogenesis of hepatitis B virus associated glomerulonephritis (HBV-GN).METHODS: The levels of serum TGF-β1 were measured by specific enzyme linked immunosorbent assay (ELISA) and HBV DNA was tested by polymerase chain reaction (PCR) in 44 patients with CHB ,and 20 healthy persons as the control. The normal human kidney proximal tubular cell (HK-2) was cultured together with the sera of healthy persons, CHB patients with HBV-DNA negative(20 cases) and HBV-DNA positive (24 cases) for up to 72 h. Apoptosis and Fas expression of the HK-2 were detected by flow cytometer.RESULTS: The apoptosis rate and Fas expression of HK-2 cells were significantly higher in HBV DNA positive serum group 19.01±5.85% and 17.58±8.35%, HBV DNA negative serum group 8.12±2.80% and 6.96 ± 2.76% than those in control group 4.25±0.65% and 2.33 ± 1.09%, respectively (P < 0.01). The apoptosis rate and Fas expression of HK-2 in HBV DNA positive serum group was significantly higher than those in HBV DNA negative serum (P < 0.01). Apoptosis rate of HK-2 cells in HBV DNA positive serum group was positively correlated with the level of HBV-DNA (r = 0.657). The level of serum TGF-β1 in CHB group was 163.05 ± 91.35 μg/L, significantly higher as compared with 81.40 ± 40.75 μg/L in the control group (P < 0.01).CONCLUSION: The serum of patients with chronic hepatitis B promotes apoptotic damage in human renal tubular cells by triggering a pathway of Fas up-regulation. HBV and TGF-β1 may play important roles in the mechanism of hepatitis B virus associated glomerulonephritis.

  6. A non-apoptotic role for BAX and BAK in eicosanoid metabolism

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    Zhang, Tejia; Walensky, Loren D.; Saghatelian, Alan

    2015-01-01

    BCL-2 proteins are key regulators of programmed cell death. The interplay between pro- and anti-apoptotic BCL-2 members has important roles in many cancers. In addition to their apoptotic function, recent evidence supports key non-apoptotic roles for several BCL-2 proteins. We used an unbiased lipidomics strategy to reveal that the pro-apoptotic proteins BAX, and to a lesser extent BAK, regulate the cellular inflammatory response by mediating COX-2 expression and prostaglandin biosynthesis. COX-2 upregulation in response to the bacterial endotoxin lipopolysaccharide is blunted in the absence of BAX, and Bax−/− mouse embryonic fibroblasts display altered kinetics of NFκB and MAPK signaling following endotoxin treatment. Our approach uncovers a novel, non-apoptotic function for BAX in regulation of the cellular inflammatory response and suggests that inflammation and apoptosis are more tightly connected than previously anticipated. PMID:25815636

  7. In vivo DNA damaging and apoptotic potential of silver nanoparticles in Swiss albino mice

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    Al Gurabi MA

    2015-01-01

    Full Text Available Mohammed A Al Gurabi, Daoud Ali, Saad Alkahtani, Saud Alarifi Department of Zoology, College of Science, King Saud University, Riyadh, Saudi Arabia Abstract: Nanoparticles can potentially cause adverse effects on organs, tissue, cell levels, and protein levels because of their physicochemical properties. Silver nanoparticles (AgNPs are being used on a wide scale in world consumer markets; their potential hazards for humans remain largely unknown. This study aimed to investigate the intraperitoneal toxicity of AgNPs (26 mg per kg of body weight, 52 mg per kg of body weight, and 78 mg per kg of body weight over 72 hours in Swiss albino mice. AgNPs induced a significant increase in serum liver injury markers including alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase. Induction of DNA damage was also studied in mice injected with AgNPs. Apoptosis (detected by using the terminal deoxynucleotidyl transferase deoxyuridine triphosphatase nick end labeling assay method in liver tissue and DNA strand breaks (detected by using the comet assay method in lymphocytes revealed that a concentration of 78 mg of AgNPs per kg body weight can cause significant apoptosis and DNA damage. The DNA damage and apoptosis raise the concern about the safety associated with application of the AgNPs. Significantly more alterations were induced in the hepatocytes of animals exposed to AgNP doses than in the control animals. The induced histological and apoptotic changes may be due to AgNP toxicity. immunohistochemical and ultrastructural of AgNP. Keywords: silver nanoparticles, liver tissue, histology, apoptosis, DNA damage, Swiss albino mice

  8. Relation between serum xenobiotic induced receptor activities and sperm DNA damage and sperm apoptotic markers in European and Inuit populations

    DEFF Research Database (Denmark)

    Long, Manhai; Stronati, Alessanda; Bizzaro, Davide;

    2007-01-01

    -mediated luciferase reporter gene expression. Sperm DNA damage was measured using terminal deoxynucleotidyl transferase-driven dUTP nick labeling assay (TUNEL) and pro- (Fas) and anti-apoptotic (Bcl-xL) markers were determined by immune methods. Different features of xenobiotic-induced receptor activity in serum...

  9. The inflammatory role of phagocyte apoptotic pathways in rheumatic diseases.

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    Cuda, Carla M; Pope, Richard M; Perlman, Harris

    2016-08-23

    Rheumatoid arthritis affects nearly 1% of the world's population and is a debilitating autoimmune condition that can result in joint destruction. During the past decade, inflammatory functions have been described for signalling molecules classically involved in apoptotic and non-apoptotic death pathways, including, but not limited to, Toll-like receptor signalling, inflammasome activation, cytokine production, macrophage polarization and antigen citrullination. In light of these remarkable advances in the understanding of inflammatory mechanisms of the death machinery, this Review provides a snapshot of the available evidence implicating death pathways, especially within the phagocyte populations of the innate immune system, in the perpetuation of rheumatoid arthritis and other rheumatic diseases. Elevated levels of signalling mediators of both extrinsic and intrinsic apoptosis, as well as the autophagy, are observed in the joints of patients with rheumatoid arthritis. Furthermore, risk polymorphisms are present in signalling molecules of the extrinsic apoptotic and autophagy death pathways. Although research into the mechanisms underlying these pathways has made considerable progress, this Review highlights areas where further investigation is particularly needed. This exploration is critical, as new discoveries in this field could lead to the development of novel therapies for rheumatoid arthritis and other rheumatic diseases.

  10. Arctigenin Treatment Protects against Brain Damage through an Anti-Inflammatory and Anti-Apoptotic Mechanism after Needle Insertion

    OpenAIRE

    2016-01-01

    Convection enhanced delivery (CED) infuses drugs directly into brain tissue. Needle insertion is required and results in a stab wound injury (SWI). Subsequent secondary injury involves the release of inflammatory and apoptotic cytokines, which have dramatic consequences on the integrity of damaged tissue, leading to the evolution of a pericontusional-damaged area minutes to days after in the initial injury. The present study investigated the capacity for arctigenin (ARC) to prevent secondary ...

  11. Role and Association of Inflammatory and Apoptotic Caspases in Renal Tubulointerstitial Fibrosis

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    You Ke

    2016-09-01

    Full Text Available Background/Aims: Caspases, an evolutionary conserved family of aspartate-specific cystein proteases, play pivotal roles in apoptotic and inflammatory signaling. Thus far, 14 mammalian caspases are identified and categorized into 3 distinct sub-types: inflammatory caspases, apoptotic initiator and apoptotic executioner. Caspase-1 is an inflammatory caspase, while caspase-7 belongs to apoptotic executioner. The roles and association of these two distinct types of caspases in renal tubulointerstitial fibrosis (TIF have not been well recognized. Methods: Caspase-1 inhibitor Z-YVAD-FMK and caspase-7 siRNA were used in tubular epithelial cell line NRK-52E (TECs to test their effects on transforming growth factor-beta1 (TGF-β1 stimulation. In vivo, Unilateral ureteral obstruction (UUO animal model was employed in wild-type (WT and caspase-1 knock out (KO (caspase-1-/- mice. Results: In current study, we found that caspase-7 was obviously activated in cultured TECs stimulated by TGF-β1 and in UUO model of WT mice. While in UUO model of caspase-1 KO mice, the increased caspase-7 activation was suppressed significantly along with reduced trans-differentiation and minimized extracellular matrix (ECM accumulation, as demonstrated by western blot, Masson trichrome staining and immunohistochemistry. In addition, pharmacological inhibition of caspase-1 dampened caspase-7 activation and TECs' transdifferentiation induced by TGF-β1 exposure, which was consistent with in vivo study. Notably, caspase-7 gene knock down by specific siRNA abrogated TGF-β1 driven TECs' trans-differentiation and reduced ECM accumulation. Conclusions: Our study associated inflammatory and apoptotic caspases in TIF for the first time and we further confirmed that caspase-1 activation is an upstream event of apoptotic caspase-7 induction in TIF triggered by UUO and in TECs mediated by TGF-β1 induced transdifferentiation.

  12. The anti-apoptotic factor Che-1/AATF links transcriptional regulation, cell cycle control, and DNA damage response

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    Fanciulli Maurizio

    2007-07-01

    Full Text Available Abstract Che-1 is a RNA polymerase II binding protein involved in the transcriptional regulation of E2F target genes and in cell proliferation. Recently, it has been shown that Che-1 accumulates in cells responding to genotoxic agents such as Doxorubicin and ionizing radiation. The DNA damage-activated checkpoint kinases ATM and Chk2 interact with and phosphorylate Che-1, enhancing its accumulation and stability, and promoting Che-1-mediated transcription of p53-responsive genes and of p53 itself, as evidenced by microarray analysis. This transcriptional response is suppressed by expression of a Che-1 mutant lacking ATM and Chk2 phosphorylation amino acid residues, or by depletion of Che-1 by RNA silencing. In addition, chromatin immunoprecipitation analysis has shown that Che-1 is released from E2F target genes and recruited to the p21 and p53 promoters after DNA damage. Che-1 contributes to the maintenance of the G2/M checkpoint in response to genotoxic stress. These findings identify a new mechanism by which the checkpoint kinases regulate, via the novel effector Che-1, the p53 pathway. Lastly, increasing evidence suggests that Che-1 may be involved in apoptotic signaling in neural tissues. In cortical neurons, Che-1 exhibits anti-apoptotic activity, protecting cells from neuronal damage induced by amyloid β-peptide. In cerebellar granule neurons, Che-1 interacts with Tau in the cytoplasmic compartment and this interaction is modulated during neuronal apoptosis. Finally, Che-1 directly interacts with the neuronal cell-death inducer "NRAGE" which downregulates endogenous Che-1 by targeting it for proteasome-dependent degradation. These findings identify Che-1 as a novel cytoprotective factor against apoptotic insults and suggest that Che-1 may represent a potential target for therapeutic application.

  13. Usage of whey protein may cause liver damage via inflammatory and apoptotic responses.

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    Gürgen, S G; Yücel, A T; Karakuş, A Ç; Çeçen, D; Özen, G; Koçtürk, S

    2015-07-01

    The purpose of this study was to investigate the long- and short-term inflammatory and apoptotic effects of whey protein on the livers of non-exercising rats. Thirty rats were divided into three groups namely (1) control group, (2) short-term whey (WS) protein diet (252 g/kg for 5 days), and (3) long-term whey (WL) protein diet (252 g/kg for 4 weeks). Interleukin 1β (IL-1β), IL-6, tumor necrosis factor α (TNF-α), and cytokeratin 18 (CK-18-M30) were assessed using enzyme-linked immunosorbent assay and immunohistochemical methods. Apoptosis was evaluated using the terminal transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) method. Hepatotoxicity was evaluated by quantitation of serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Based on the biochemical levels and immunohistochemical results, the highest level of IL-1β was identified in the WL group (p whey protein is used in an uninformed manner and without exercising, adverse effects on the liver may occur by increasing the apoptotic signal in the short term and increasing inflammatory markers and hepatotoxicity in the long term.

  14. Lovastatin prevents cisplatin-induced activation of pro-apoptotic DNA damage response (DDR) of renal tubular epithelial cells.

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    Krüger, Katharina; Ziegler, Verena; Hartmann, Christina; Henninger, Christian; Thomale, Jürgen; Schupp, Nicole; Fritz, Gerhard

    2016-02-01

    The platinating agent cisplatin (CisPt) is commonly used in the therapy of various types of solid tumors. The anticancer efficacy of CisPt largely depends on the formation of bivalent DNA intrastrand crosslinks, which stimulate mechanisms of the DNA damage response (DDR), thereby triggering checkpoint activation, gene expression and cell death. The clinically most relevant adverse effect associated with CisPt treatment is nephrotoxicity that results from damage to renal tubular epithelial cells. Here, we addressed the question whether the HMG-CoA-reductase inhibitor lovastatin affects the DDR of renal cells by employing rat renal proximal tubular epithelial (NRK-52E) cells as in vitro model. The data show that lovastatin has extensive inhibitory effects on CisPt-stimulated DDR of NRK-52E cells as reflected on the levels of phosphorylated ATM, Chk1, Chk2, p53 and Kap1. Mitigation of CisPt-induced DDR by lovastatin was independent of the formation of DNA damage as demonstrated by (i) the analysis of Pt-(GpG) intrastrand crosslink formation by Southwestern blot analyses and (ii) the generation of DNA strand breaks as analyzed on the level of nuclear γH2AX foci and employing the alkaline comet assay. Lovastatin protected NRK-52E cells from the cytotoxicity of high CisPt doses as shown by measuring cell viability, cellular impedance and flow cytometry-based analyses of cell death. Importantly, the statin also reduced the level of kidney DNA damage and apoptosis triggered by CisPt treatment of mice. The data show that the lipid-lowering drug lovastatin extensively counteracts pro-apoptotic signal mechanisms of the DDR of tubular epithelial cells following CisPt injury.

  15. The roles and acting mechanism of Caenorhabditis elegans DNase II genes in apoptotic dna degradation and development.

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    Huey-Jen Lai

    Full Text Available DNase II enzymes are acidic endonucleases that have been implicated in mediating apoptotic DNA degradation, a critical cell death execution event. C. elegans genome contains three DNase II homologues, NUC-1, CRN-6, and CRN-7, but their expression patterns, acting sites, and roles in apoptotic DNA degradation and development are unclear. We have conducted a comprehensive analysis of three C. elegans DNase II genes and found that nuc-1 plays a major role, crn-6 plays an auxiliary role, and crn-7 plays a negligible role in resolving 3' OH DNA breaks generated in apoptotic cells. Promoter swapping experiments suggest that crn-6 but not crn-7 can partially substitute for nuc-1 in mediating apoptotic DNA degradation and both fail to replace nuc-1 in degrading bacterial DNA in intestine. Despite of their restricted and largely non-overlapping expression patterns, both CRN-6 and NUC-1 can mediate apoptotic DNA degradation in many cells, suggesting that they are likely secreted nucleases that are retaken up by other cells to exert DNA degradation functions. Removal or disruption of NUC-1 secretion signal eliminates NUC-1's ability to mediate DNA degradation across its expression border. Furthermore, blocking cell corpse engulfment does not affect apoptotic DNA degradation mediated by nuc-1, suggesting that NUC-1 acts in apoptotic cells rather than in phagocytes to resolve 3' OH DNA breaks. Our study illustrates how multiple DNase II nucleases play differential roles in apoptotic DNA degradation and development and reveals an unexpected mode of DNase II action in mediating DNA degradation.

  16. Simultaneous detection and semiquantification of DNA damage in normal and apoptotic cells: triple-immunofluorescent labeling using DAPI, antibodies, and TUNEL.

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    Agrawal, Anant; Godar, Dianne E

    2012-07-01

    We developed a triple-labeling immunofluorescence technique that simultaneously identifies total DNA (DAPI), DNA damage (antibodies), and dead cells [terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL)-positive cells] and a method that semiquantifies DNA damage in paraffin-embedded tissues. Using this technique in combination with our analysis method, scientists can now simultaneously detect and compare the relative amounts of DNA damage of almost any kind (except single-strand and double-strand breaks), using indirect fluorescent antibody labeling, in both normal and dying cells of different tissues. Simultaneous labeling of DNA damage and dead or TUNEL-positive cells can reduce processing costs and analysis time, and can lead to discoveries concerning how cells die from different DNA damages. We used increasing doses of UV (290 to 400 nm) radiation to create DNA damage in the form of cyclobutane pyrimidine dimers and 6-4 photoproducts that kill some of the cells in 3-dimensional tissue-engineered skin and vaginal samples. We describe a protocol that reliably detects and semiquantifies DNA damage in both normal and apoptotic cells. We show this triple-labeling immunofluorescence technique and analysis method yields linear UV dose response curves for damage to DNA bases that allows semiquantification of cyclobutane pyrimidine dimers and calculation of its repair rate (T=1 and 24 h), whereas TUNEL allows quantification of the number of apoptotic cells. Scientists can now create beautiful fluorescent pictures that simultaneously detect DNA damage in both normal and apoptotic cells to assess and semiquantify the damage to understand better how different insults lead to the cell's demise.

  17. Investigation of DNA damage response and apoptotic gene methylation pattern in sporadic breast tumors using high throughput quantitative DNA methylation analysis technology

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    Prakash Neeraj

    2010-11-01

    Full Text Available Abstract Background- Sporadic breast cancer like many other cancers is proposed to be a manifestation of abnormal genetic and epigenetic changes. For the past decade our laboratory has identified genes involved in DNA damage response (DDR, apoptosis and immunesurvelliance pathways to influence sporadic breast cancer risk in north Indian population. Further to enhance our knowledge at the epigenetic level, we performed DNA methylation study involving 17 gene promoter regions belonging to DNA damage response (DDR and death receptor apoptotic pathway in 162 paired normal and cancerous breast tissues from 81 sporadic breast cancer patients, using a high throughput quantitative DNA methylation analysis technology. Results- The study identified five genes with statistically significant difference between normal and tumor tissues. Hypermethylation of DR5 (P = 0.001, DCR1 (P = 0.00001, DCR2 (P = 0.0000000005 and BRCA2 (P = 0.007 and hypomethylation of DR4 (P = 0.011 in sporadic breast tumor tissues suggested a weak/aberrant activation of the DDR/apoptotic pathway in breast tumorigenesis. Negative correlation was observed between methylation status and transcript expression levels for TRAIL, DR4, CASP8, ATM, CHEK2, BRCA1 and BRCA2 CpG sites. Categorization of the gene methylation with respect to the clinicopathological parameters showed an increase in aberrant methylation pattern in advanced tumors. These uncharacteristic methylation patterns corresponded with decreased death receptor apoptosis (P = 0.047 and DNA damage repair potential (P = 0.004 in advanced tumors. The observation of BRCA2 -26 G/A 5'UTR polymorphism concomitant with the presence of methylation in the promoter region was novel and emerged as a strong candidate for susceptibility to sporadic breast tumors. Conclusion- Our study indicates that methylation of DDR-apoptotic gene promoters in sporadic breast cancer is not a random phenomenon. Progressive epigenetic alterations in advancing

  18. Role Of S-Nitrosylation In The Extrinsic Apoptotic Signalling Pathway In Cancer

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    Stéphanie Plenchette

    2015-08-01

    Full Text Available One of the key features of tumour cells is the acquisition of resistance to apoptosis. Thus, determining therapeutic strategies that circumvent apoptotic resistance and result in tumor regression is a challenge. One strategy to induce apoptosis is to activate death receptor signalling pathways. Members of the Tumor Necrosis Factor TNF-family death receptors ligand (TRAIL, FasL and TNF-α can originate from immune and non-immune cells. Death receptors, engaged by cognate ligands, can initiate multiple signaling pathways, which can generate diverse outcomes, including non-apoptosis-related signal. Knowledge on the molecular mechanisms (that determine death or survival of tumour cells following exposure to the TNF-family death receptors ligands have demonstrated that post-translational modifications of the signaling pathway components play a critical role in determining cell fate. Cell death can be sensed by nitric oxide (NO in a wide variety of tumour cells. S-nitrosylation, the covalent modification of a protein cysteine thiol by an NO moiety, has emerged as an important post-translational regulation for the TNF-family death receptor signaling pathways. It has been demonstrated that death receptor DR4 (TRAIL-R1 becomes S-nitrosylated and promotes apoptosis following a specific NO donor treatment (Tang et al., 2006. Then, our group has shown that S-nitrosylation of Fas, following glyceryl trinitrate (GTN exposure, promotes redistribution of the receptor to lipid rafts, formation of the death-inducing signal complex (DISC, and induction of cell death. Finally, I will discuss our recent efforts to decipher regulatory mechanism of the TNF-α/TNFR1 signalling cell death pathway by S-nitrosylation following GTN treatment.

  19. Role of BK channels in the apoptotic volume decrease in native eel intestinal cells

    DEFF Research Database (Denmark)

    Lionetto, Maria Giulia; Giordano, Maria Elena; Calisi, Antonio

    2010-01-01

    of these channels in the Apoptotic Volume Decrease (AVD) of isolated eel enterocytes, and the possible interaction between BK channels and the progression of apoptosis. The detection of apoptosis was performed by confocal microscopy and annexin V and propidium iodide labelling; cell volume changes were monitored...

  20. Protective role of metallothionein (Ⅰ/Ⅱ) against pathological damage and apoptosis induced by dimethylarsinic acid

    Institute of Scientific and Technical Information of China (English)

    Guang Jia; Yi-Qun Gu; Kung-Tung Chen; You-Yong Lu; Lei Yan; Jian-Ling Wang; Ya-Ping Su; J. C. Gaston Wu

    2004-01-01

    AIM: To better clarify the main target organs of dimethylarsinic acid toxicity and the role of metallothionein (MTs) in modifying dimethylarsinic acid (DMAA) toxicity.METHODS: MT-Ⅰ/Ⅱ null (MT-/-) mice and the corresponding wild-type mice (MT+/+), six in each group, were exposed to DMAA (0-750 mg/kg body weight) by a single oral injection.Twenty four hours later, the lungs, livers and kidneys were collected and undergone pathological analysis, induction of apoptotic cells as determined by TUNEL and MT concentration was detected by radio-immunoassay.RESULTS: Remarkable pathological lesions were observed at the doses ranging from 350 to 750 mg/kg body weight in the lungs, livers and kidneys and MT+/+ mice exhibited a relatively slight destruction when compared with that in dose matched MT-/- mice. The number of apoptotic cells was increased in a dose dependent manner in the lungs and livers in both types of mice. DMAA produced more necrotic cells rather than apoptotic cells at the highest dose of 750 mg/kg,however, no significant increase was observed in the kidney.Hepatic MT level in MT+/+ mice was significantly increased by DMAA in a dose-dependent manner and there was nodetectable amount of hepatic MT in untreated MT-/- mice.CONCLUSION: DMAA treatment can lead to the induction of apoptosis and pathological damage in both types of mice.MT exhibits a protective effect against DMAA toxicity.

  1. The role of pneumolysin in mediating lung damage in a lethal pneumococcal pneumonia murine model

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    Pirofski Liise-Anne

    2007-01-01

    Full Text Available Abstract Background Intranasal inoculation of Streptococcus pneumoniae D39 serotype 2 causes fatal pneumonia in mice. The cytotoxic and inflammatory properties of pneumolysin (PLY have been implicated in the pathogenesis of pneumococcal pneumonia. Methods To examine the role of PLY in this experimental model we performed ELISA assays for PLY quantification. The distribution patterns of PLY and apoptosis were established by immunohistochemical detection of PLY, caspase-9 activity and TUNEL assay on tissue sections from mice lungs at various times, and the results were quantified with image analysis. Inflammatory and apoptotic cells were also quantified on lung tissue sections from antibody treated mice. Results In bronchoalveolar lavages (BAL, total PLY was found at sublytic concentrations which were located in alveolar macrophages and leukocytes. The bronchoalveolar epithelium was PLY-positive, while the vascular endothelium was not PLY reactive. The pattern and extension of cellular apoptosis was similar. Anti-PLY antibody treatment decreased the lung damage and the number of apoptotic and inflammatory cells in lung tissues. Conclusion The data strongly suggest that in vivo lung injury could be due to the pro-apoptotic and pro-inflammatory activity of PLY, rather than its cytotoxic activity. PLY at sublytic concentrations induces lethal inflammation in lung tissues and is involved in host cell apoptosis, whose effects are important to pathogen survival.

  2. Deregulation of apoptotic volume decrease and ionic movements in multidrug-resistant tumor cells: role of chloride channels

    DEFF Research Database (Denmark)

    Poulsen, Kristian Arild; Andersen, E C; Hansen, C F;

    2010-01-01

    Changes in cell volume and ion gradients across the plasma membrane play a pivotal role in the initiation of apoptosis. Here we explore the kinetics of apoptotic volume decrease (AVD) and ion content dynamics in wild-type (WT) and multidrug-resistant (MDR) Ehrlich ascites tumor cells (EATC). In WT......3728 inhibited AVD and completely abolished the differences in AVD, ionic movements, and caspase 3 activation between WT and MDR EATC. Finally, the maximal capacity of volume-regulated anion channel was found to be strongly repressed in MDR EATC. Together, these data suggest that impairment of AVD...

  3. Hydroalcoholic extract of cyperus rotundus ameliorates H2O2-induced human neuronal cell damage via its anti-oxidative and anti-apoptotic machinery.

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    Kumar, K Hemanth; Khanum, Farhath

    2013-01-01

    Hydrogen peroxide (H(2)O(2)), a major reactive oxygen species produced during oxidative stress, has been implicated in the pathophysiology of various neurodegenerative conditions. Cyperus rotundus is a traditional medicinal herb that has recently found applications in food and confectionary industries. In the current study, the neuroprotective effects of Cyperus rotundus rhizome extract (CRE) through its antioxidant and anti-apoptotic machinery to attenuate H(2)O(2)-induced cell damage on human neuroblastoma SH-SY5Y cells have been explored. The results obtained demonstrate that pretreatment of cells with CRE for 2 h before administration of H(2)O(2) for 24 h ameliorates the cytotoxicity induced by H(2)O(2) as evidenced by MTT and LDH assays. CRE exhibited potent antioxidant activity by regulating the enzymes/proteins levels such as SOD, CAT, GPx, GR, HSP-70, Caspase-3, and Bcl-2. The pretreatment restored H(2)O(2)-induced cellular, nuclear, and mitochondrial morphologies as well as increased the expression of Brain derived nerve growth factor (BDNF). The anti-oxidant and anti-apoptotic potentials of the plant extract may account for its high content of phenolics, flavonoids, and other active principles. Taken together, our findings suggest that CRE might be developed as an agent for neurodegeneration prevention or therapy.

  4. Modeling the role of p53 pulses in DNA damage- induced cell death decision

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    Cui Jun

    2009-06-01

    Full Text Available Abstract Background The tumor suppressor p53 plays pivotal roles in tumorigenesis suppression. Although oscillations of p53 have been extensively studied, the mechanism of p53 pulses and their physiological roles in DNA damage response remain unclear. Results To address these questions we presented an integrated model in which Ataxia-Telangiectasia Mutated (ATM activation and p53 oscillation were incorporated with downstream apoptotic events, particularly the interplays between Bcl-2 family proteins. We first reproduced digital oscillation of p53 as the response of normal cells to DNA damage. Subsequent modeling in mutant cells showed that high basal DNA damage is a plausible cause for sustained p53 pulses observed in tumor cells. Further computational analyses indicated that p53-dependent PUMA accumulation and the PUMA-controlled Bax activation switch might play pivotal roles to count p53 pulses and thus decide the cell fate. Conclusion The high levels of basal DNA damage are responsible for generating sustained pulses of p53 in the tumor cells. Meanwhile, the Bax activation switch can count p53 pulses through PUMA accumulation and transfer it into death signal. Our modeling provides a plausible mechanism about how cells generate and orchestrate p53 pulses to tip the balance between survival and death.

  5. In Vivo Effects of Vanadium Pentoxide and Antioxidants (Ascorbic Acid and Alpha-Tocopherol) on Apoptotic, Cytotoxic, and Genotoxic Damage in Peripheral Blood of Mice

    Science.gov (United States)

    García-Rodríguez, María del Carmen; Hernández-Cortés, Lourdes Montserrat; Altamirano-Lozano, Mario Agustín

    2016-01-01

    This study was conducted to investigate the effects of vanadium pentoxide (V2O5), ascorbic acid (AA), and alpha-tocopherol (α-TOH) on apoptotic, cytotoxic, and genotoxic activity. Groups of five Hsd:ICR mice were treated with the following: (a) vehicle, distilled water; (b) vehicle, corn oil; (c) AA, 100 mg/kg intraperitoneally (ip); (d) α-TOH, 20 mg/kg by gavage; (e) V2O5, 40 mg/kg by ip injection; (f) AA + V2O5; and (g) α-TOH + V2O5. Genotoxic damage was evaluated by examining micronucleated polychromatic erythrocytes (MN-PCE) obtained from the caudal vein at 0, 24, 48, and 72 h after treatments. Induction of apoptosis and cell viability were assessed at 48 h after treatment in nucleated cells of peripheral blood. Treatment with AA alone reduced basal MN-PCE, while V2O5 treatment marginally increased MN-PCE at all times after injection. Antioxidants treatments prior to V2O5 administration decreased MN-PCE compared to the V2O5 group, with the most significant effect in the AA + V2O5 group. The apoptotic cells increased with all treatments, suggesting that this process may contribute to the elimination of the cells with V2O5-induced DNA damage (MN-PCE). The necrotic cells only increased in the V2O5 group. Therefore, antioxidants such as AA and α-TOH can be used effectively to protect or reduce the genotoxic effects induced by vanadium compounds like V2O5. PMID:27413422

  6. Human Noxin is an anti-apoptotic protein in response to DNA damage of A549 non-small cell lung carcinoma.

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    Won, Kyoung-Jae; Im, Joo-Young; Yun, Chae-Ok; Chung, Kyung-Sook; Kim, Young Joo; Lee, Jung-Sun; Jung, Young-Jin; Kim, Bo-Kyung; Song, Kyung Bin; Kim, Young-Ho; Chun, Ho-Kyung; Jung, Kyeong Eun; Kim, Moon-Hee; Won, Misun

    2014-06-01

    Human Noxin (hNoxin, C11Orf82), a homolog of mouse noxin, is highly expressed in colorectal and lung cancer tissues. hNoxin contains a DNA-binding C-domain in RPA1, which mediates DNA metabolic processes, such as DNA replication and DNA repair. Expression of hNoxin is associated with S phase in cancer cells and in normal cells. Expression of hNoxin was induced by ultraviolet (UV) irradiation. Knockdown of hNoxin caused growth inhibition of colorectal and lung cancer cells. The comet assay and western blot analysis revealed that hNoxin knockdown induced apoptosis through activation of p38 mitogen-activated protein kinase (MAPK)/p53 in non-small cell lung carcinoma A549 cells. Furthermore, simultaneous hNoxin knockdown and treatment with DNA-damaging agents, such as camptothecin (CPT) and UV irradiation, enhanced apoptosis, whereas Trichostatin A (TSA) did not. However, transient overexpression of hNoxin rescued cells from DNA damage-induced apoptosis but did not block apoptosis in the absence of DNA damage. These results suggest that hNoxin may be associated with inhibition of apoptosis in response to DNA damage. An adenovirus expressing a short hairpin RNA against hNoxin transcripts significantly suppressed the growth of A549 tumor xenografts, indicating that hNoxin knockdown has in vivo anti-tumor efficacy. Thus, hNoxin is a DNA damage-induced anti-apoptotic protein and potential therapeutic target in cancer.

  7. Apoptotic markers and DNA damage are related to late phase of stroke: Involvement of dyslipidemia and inflammation.

    Science.gov (United States)

    Pascotini, Eduardo Tanuri; Flores, Ariane Ethur; Kegler, Aline; Gabbi, Patricia; Bochi, Guilherme Vargas; Algarve, Thais Doeler; Prado, Ana Lucia Cervi; Duarte, Marta M M F; da Cruz, Ivana B M; Moresco, Rafael Noal; Royes, Luiz Fernando Freire; Fighera, Michele Rechia

    2015-11-01

    Oxidative stress and brain inflammation are thought to contribute to the pathophysiology of cerebral injury in acute stroke, leading to apoptosis and cell death. Lipid accumulation may lead to progression of carotid plaques and inflammation, contributing to increased acute stroke risk. However, little is known about these events and markers in the late stroke (>6 months) and if dyslipidemia could contribute to disease's pathophysiology in a later phase. In this case-control study, we recruited patients in the late stroke phase (n=40) and health subjects (control group; n = 40). Dichlorodihydrofluorescein (DCFH), nitrite/nitrate (NOx), Tumor necrosis factor-alpha (TNF-α), Acetylcholinesterase (AChE), Caspase 8 (CASP 8), Caspase 3 (CASP 3) and Picogreen (PG) were measured in periphery blood samples. Furthermore, a correlation among all measured markers (DCFH, NOx, TNF-α, AChE, CASP 8, CASP 3 and PG) was realized. The marker levels were also compared to triglycerides (TG), total (CHO), LDL and HDL cholesterol levels and medications used. Statistical analyses showed that stroke patients presented an increase of DCFH, NOx, TNF-α and AChE levels when compared to control subjects. In addition, we observed that stroke patients had significantly higher CASP 8, CASP 3 and PG levels than control group. A significant correlation between TNF-α with CASP 8 (r = 0.4) and CASP 3 (r = 0.4) levels was observed, but not with oxidative/nitrosative markers. Moreover, we observed that stroke patients with dyslipidemia had significantly higher TNF-α, CASP 8 and CASP 3 levels than stroke without dyslipidemia and control groups. Our findings suggest that oxidative and inflammatory markers may be still increased and lead to caspase activation and DNA damage even after 6 months to cerebral injury. Furthermore, it is plausible to propose that dyslipidemia may contribute to worsen proinflammatory state in a later phase of stroke and an increased risk to new neurovascular events.

  8. Hydroxylation of multi-walled carbon nanotubes: Enhanced biocompatibility through reduction of oxidative stress initiated cell membrane damage, cell cycle arrestment and extrinsic apoptotic pathway.

    Science.gov (United States)

    Liu, Zhenbao; Liu, Yanfei; Peng, Dongming

    2016-10-01

    Modification of CNTs with hydroxyl group promotes their applications in biomedical area. However, the impact of hydroxylation on their biocompatibility is far from being completely understood. In this study, we carried out a comprehensive evaluation of hydroxylated multi-walled carbon nanotubes (MWCNTs-OH) on the human normal liver L02 cell line, and compared it with that of pristine multi-walled carbon nanotubes (p-MWCNTs). Results demonstrated that compared with p-MWCNTs, MWCNTs-OH induced significantly lower oxidative stress as indicated by the level of intracellular antioxidant glutathione (GSH), subsequently lead to less cell membrane damage as demonstrated by lactate dehydrogenase (LDH) leakage assay, and showed slightly decreased arrestment of cell cycle distribution at G0/G1. More interestingly, MWCNTs-OH exhibited significantly lower tendency to activate caspase-8, a key molecule involved in the extrinsic apoptotic pathway. All these in vitro results demonstrated that hydroxylation of MWCNTs enhanced their biocompatibility compare with p-MWCNTs.

  9. Ionizing irradiation induces apoptotic damage of salivary gland acinar cells via NADPH oxidase 1-dependent superoxide generation.

    Science.gov (United States)

    Tateishi, Yoshihisa; Sasabe, Eri; Ueta, Eisaku; Yamamoto, Tetsuya

    2008-02-01

    Reactive oxygen species (ROS) have important roles in various physiological processes. Recently, several novel homologues of the phagocytic NADPH oxidase have been discovered and this protein family is now designated as the Nox family. We investigated the involvement of Nox family proteins in ionizing irradiation-induced ROS generation and impairment in immortalized salivary gland acinar cells (NS-SV-AC), which are radiosensitive, and immortalized ductal cells (NS-SV-DC), which are radioresistant. Nox1-mRNA was upregulated by gamma-ray irradiation in NS-SV-AC, and the ROS level in NS-SV-AC was increased to approximately threefold of the control level after 10Gy irradiation. The increase of ROS level in NS-SV-AC was suppressed by Nox1-siRNA-transfection. In parallel with the suppression of ROS generation and Nox1-mRNA expression by Nox1-siRNA, ionizing irradiation-induced apoptosis was strongly decreased in Nox1-siRNA-transfected NS-SV-AC. There were no large differences in total SOD or catalase activities between NS-SV-AC and NS-SV-DC although the post-irradiation ROS level in NS-SV-AC was higher than that in NS-SV-DC. In conclusion, these results indicate that Nox1 plays a crucial role in irradiation-induced ROS generation and ROS-associated impairment of salivary gland cells and that Nox1 gene may be targeted for preservation of the salivary gland function from radiation-induced impairment.

  10. ROLE OF CASPASE-3 IN ACUTE LIGHT DAMAGE TO RETINA OF RATS

    Institute of Scientific and Technical Information of China (English)

    Xiao Wang; Shi-xing Hu; Wei Li; Shao-chun Lin

    2007-01-01

    Objective To investigate the role of Caspase-3 in retinal damage caused by light exposure in rats.Methods Light injury to retina was induced by persistent exposure to illumination (intensity; 30000±50 lux) of operating microscope for 30 minutes in the right eyes of Sprague-Dawley rats. The pathological changes of retina were observed under optical and electron microscopies at different time points, which were 6 hours, 1,3,7,and 15 days after the light exposure. Apoptosis of retinal cells was analyzed by flow cytometry. The activity of Caspase-3 was evaluated by using the Caspase-3 assay kit. At the same time, the expression of Caspase-3 protease was determined with Western blot analysis.Results The examination results of optical and transmission electron microscopes showed that edema of inner and outer segments of the retina, espectially the chondriosome inside the inner segment, became obvious 6 hours after the light exposure. The change was deteriorated along with the increasing time. The structures of the discoidal valve dissociated in the outer segment simultaneously. Disorderly arranged nuclei, karyopycnosis, and thinning in the outer nuclear layer were observed. The retinal pogment epithelium almost disappeared during the later stage. The staining results of Annexin-V combined with PI demonstrated that the proportion of apoptotic cells increased with time. The proportion between 7th day (82.7%) and 15th day (80.4%), however, showed no significant difference. Caspase-3 became remarkably active with the lapse of time, which increased from 0.02 at 6th hour to the peak of 9.8 at 7th day before it started to descend. The Western blot detected a expression of the active form of Caspase-3 at 7th day and 15th day.Conclusion Apoptosis of photoreceptor cells is markedly involved in the light damage and Caspase-3 protease may play an important role in the apoptotic process of the retina after light exposure in rats.

  11. Cerium Oxide Nanoparticles Induced Toxicity in Human Lung Cells: Role of ROS Mediated DNA Damage and Apoptosis

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    Sandeep Mittal

    2014-01-01

    Full Text Available Cerium oxide nanoparticles (CeO2 NPs have promising industrial and biomedical applications. In spite of their applications, the toxicity of these NPs in biological/physiological environment is a major concern. Present study aimed to understand the molecular mechanism underlying the toxicity of CeO2 NPs on lung adenocarcinoma (A549 cells. After internalization, CeO2 NPs caused significant cytotoxicity and morphological changes in A549 cells. Further, the cell death was found to be apoptotic as shown by loss in mitochondrial membrane potential and increase in annexin-V positive cells and confirmed by immunoblot analysis of BAX, BCl-2, Cyt C, AIF, caspase-3, and caspase-9. A significant increase in oxidative DNA damage was found which was confirmed by phosphorylation of p53 gene and presence of cleaved poly ADP ribose polymerase (PARP. This damage could be attributed to increased production of reactive oxygen species (ROS with concomitant decrease in antioxidant “glutathione (GSH” level. DNA damage and cell death were attenuated by the application of ROS and apoptosis inhibitors N-acetyl-L- cysteine (NAC and Z-DEVD-fmk, respectively. Our study concludes that ROS mediated DNA damage and cell cycle arrest play a major role in CeO2 NPs induced apoptotic cell death in A549 cells. Apart from beneficial applications, these NPs also impart potential harmful effects which should be properly evaluated prior to their use.

  12. Targeting PKC: a novel role for beta-catenin in ER stress and apoptotic signaling.

    Science.gov (United States)

    Raab, Marc S; Breitkreutz, Iris; Tonon, Giovanni; Zhang, Jing; Hayden, Patrick J; Nguyen, Thu; Fruehauf, Johannes H; Lin, Boris K; Chauhan, Dharminder; Hideshima, Teru; Munshi, Nikhil C; Anderson, Kenneth C; Podar, Klaus

    2009-02-12

    Targeting protein kinase C (PKC) isoforms by the small molecule inhibitor enzastaurin has shown promising preclinical activity in a wide range of tumor cells. We further delineated its mechanism of action in multiple myeloma (MM) cells and found a novel role of beta-catenin in regulating growth and survival of tumor cells. Specifically, inhibition of PKC leads to rapid accumulation of beta-catenin by preventing the phosphorylation required for its proteasomal degradation. Microarray analysis and small-interfering RNA (siRNA)-mediated gene silencing in MM cells revealed that accumulated beta-catenin activates early endoplasmic reticulum stress signaling via eIF2alpha, C/EBP-homologous protein (CHOP), and p21, leading to immediate growth inhibition. Furthermore, accumulated beta-catenin contributes to enzastaurin-induced cell death. Sequential knockdown of beta-catenin, c-Jun, and p73, as well as overexpression of beta-catenin or p73 confirmed that accumulated beta-catenin triggers c-Jun-dependent induction of p73, thereby conferring MM cell apoptosis. Our data reveal a novel role of beta-catenin in endoplasmic reticulum (ER) stress-mediated growth inhibition and a new proapoptotic mechanism triggered by beta-catenin on inhibition of PKC isoforms. Moreover, we identify p73 as a potential novel therapeutic target in MM. Based on these and previous data, enzastaurin is currently under clinical investigation in a variety of hematologic malignancies, including MM.

  13. An investigation of the effects of Cinnamomum cassia bark extracts on oxidative DNA damage and possible cytotoxic and apoptotic activities in transformed/untransformed cell lines from Type 1 diabetic patients, in vitro.

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    Ferzan Lermioglu Erciyas

    2015-05-01

    Full Text Available It was shown that patients with Type 1 diabetes mellitus (T1DM had increased level of oxidative DNA damage and decreased efficacy of DNA repair. These changes were implicated in the increased cancer risk in patients with diabetes mellitus. Cinnamon bark extracts have diverse biological activities including antidiabetic and anti-tumor properties. Cinnamomum cassia (C. cassia is a common used cinnamon species present in commercial cinnamon preparations. We aimed to investigate the effects of cinnamon extracts prepared from C. cassia bark on endogenous and hydrogen peroxide (H2O2-induced oxidative DNA damage, as well as cytotoxic and apoptotic activities in this study. Type 1 diabetic (T1DM lymphocytes (GM02765, GM01838 and fibroblasts (GM01837 were obtained from NIGMS Human Genetic Cell Repository of Coriell Institute, New Jersey, USA. Cytotoxicity analysis were performed by using a tetrazolium salt, 4-[3-(4-iodophenyl 2-(4-nitrophenyl 2H-5-tetrazolio] 1,3-benzene disulfonate (WST-1. The effects of extracts on endogenous and H2O2-induced oxidative DNA damage were studied using the single cell gel electrophoresis (SCGE; Comet Assay, a technique allowing DNA damage in a single cell. Apoptotic activities of extracts were investigated by TUNEL and Annexin V/PI assays. using flow cytometry. IC50 and IC20 values of the extracts varied and the effects on endogenous and H2O2-induced DNA damage were different regarding cell lines and extracts. Although their protective effects at some doses against to H2O2-induced oxidative damage, our results suggested DNA damaging and apoptotic potential of cinnamon bark extracts on Type 1 diabetic cell lines, in vitro.

  14. Cytoplasmic and nuclear anti-apoptotic roles of αB-crystallin in retinal pigment epithelial cells.

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    Woo Jin Jeong

    Full Text Available In addition to its well-characterized role in the lens, αB-crystallin performs other functions. Methylglyoxal (MGO can alter the function of the basement membrane of retinal pigment epithelial (RPE cells. Thus, if MGO is not efficiently detoxified, it can induce adverse reactions in RPE cells. In this study, we examined the mechanisms underlying the anti-apoptotic activity of αB-crystallin in the human retinal pigment epithelial cell line ARPE-19 following MGO treatment using various assays, including nuclear staining, flow cytometry, DNA electrophoresis, pulse field gel electrophoresis, western blot analysis, confocal microscopy and co-immunoprecipitation assays. To directly assess the role of phosphorylation of αB-crystallin, we used site-directed mutagenesis to convert relevant serine residues to alanine residues. Using these techniques, we demonstrated that MGO induces apoptosis in ARPE-19 cells. Silencing αB-crystallin sensitized ARPE-19 cells to MGO-induced apoptosis, indicating that αB-crystallin protects ARPE-19 cells from MGO-induced apoptosis. Furthermore, we found that αB-crystallin interacts with the caspase subtypes, caspase-2L, -2S, -3, -4, -7, -8, -9 and -12 in untreated control ARPE-19 cells and that MGO treatment caused the dissociation of these caspase subtypes from αB-crystallin; transfection of S19A, S45A or S59A mutants caused the depletion of αB-crystallin from the nuclei of untreated control RPE cells leading to the release of caspase subtypes. Additionally, transfection of these mutants enhanced MGO-induced apoptosis in ARPE-19 cells, indicating that phosphorylation of nuclear αB-crystallin on serine residues 19, 45 and 59 plays a pivotal role in preventing apoptosis in ARPE-19 cells. Taken together, these results suggest that αB-crystallin prevents caspase activation by physically interacting with caspase subtypes in the cytoplasm and nucleus, thereby protecting RPE cells from MGO-induced apoptosis.

  15. Apoptotic potential role of Agave palmeri and Tulbaghia violacea extracts in cervical cancer cells.

    Science.gov (United States)

    Mthembu, Nonkululeko N; Motadi, Lesetja Raymond

    2014-09-01

    Cervical cancer, a gynaecological malignant disorder, is a common cause of death in females in Sub-Saharan Africa, striking nearly half a million of lives each year worldwide. Currently, more than 50 % of all modern drugs in clinical use are of natural products, many of which have an ability to control cancer cells (Madhuri and Pandey, Curr Sci 96:779-783, 2009; Richter, Traditional medicines and traditional healers in South Africa, 2003). In South Africa, plants used to treat cancer are rare even though majority of our population continue to put their trust in traditional medicine. In this study we aimed to screen Agave palmeri (AG) and Tulbaghia violacea (TV) for potential role in inducing cell death in cervical cancer cell lines HeLa and ME-180, and in normal human fibroblast cell line KMST-6 cell lines. To achieve this, AG and TV crude extracts were utilized to screen for apoptosis induction, inhibition of cell proliferation followed by elucidation of the role of Bax, Bcl-2, p53, Rb, RBBP and Mdm2 genes in cervical cancer. In brief, plant leaves and roots were collected, crushed and methanolic extracts obtained. Different concentrations of the stock extracts were used to treat cancer cells and measure cell death using the [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay and flow cytometry. Western blot was applied to measure gene expression at protein level using RBBP6, p53, Mdm2, Rb, Bax, Bcl-2 and β-actin mouse monoclonal primary antibodies (IgG) and goat anti mouse coupled with horseradish peroxidase secondary antibody from Santa Cruz Biotechnology and real time-PCR was used for mRNA expression level. Plant extracts of AG and TV were time (24 h) and dose (50, 100, 150 μg/ml) dependent in their induction of cell death with an IC50 ~ 150 μg/ml. A further mixed respond by several genes was observed following treatment with the two plant extracts where RBBP6 was seen to be spliced in cancer cells while Bax was induced and Bcl-2 was

  16. Concurrent proinflammatory and apoptotic activity of a Helicobacter pylori protein (HP986 points to its role in chronic persistence.

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    Ayesha Alvi

    Full Text Available Helicobacter pylori induces cytokine mediated changes in gastroduodenal pathophysiology, wherein, the activated macrophages at the sub-mucosal space play a central role in mounting innate immune response against the antigens. The bacterium gains niche through persistent inflammation and local immune-suppression causing peptic ulcer disease or chronic gastritis; the latter being a significant risk factor for the development of gastric adenocarcinoma. What favors persistence of H. pylori in the gastric niches is not clearly understood. We report detailed characterization of a functionally unknown gene (HP986, which was detected in patient isolates associated with peptic ulcer and gastric carcinoma. Expression and purification of recombinant HP986 (rHP986 revealed a novel, ∼29 kDa protein in biologically active form which associates with significant levels of humoral immune responses in diseased individuals (p<0.001. Also, it induced significant levels of TNF-α and Interleukin-8 in cultured human macrophages concurrent to the translocation of nuclear transcription factor-κB (NF-κB. Further, the rHP986 induced apoptosis of cultured macrophages through a Fas mediated pathway. Dissection of the underlying signaling mechanism revealed that rHP986 induces both TNFR1 and Fas expression to lead to apoptosis. We further demonstrated interaction of HP986 with TNFR1 through computational and experimental approaches. Independent proinflammatory and apoptotic responses triggered by rHP986 as shown in this study point to its role, possibly as a survival strategy to gain niche through inflammation and to counter the activated macrophages to avoid clearance.

  17. Immunosuppressive effects of apoptotic cells

    Science.gov (United States)

    Voll, Reinhard E.; Herrmann, Martin; Roth, Edith A.; Stach, Christian; Kalden, Joachim R.; Girkontaite, Irute

    1997-11-01

    Apoptotic cell death is important in the development and homeostasis of multicellular organisms and is a highly controlled means of eliminating dangerous, damaged or unnecessary cells without causing an inflammatory response or tissue damage,. We now show that the presence of apoptotic cells during monocyte activation increases their secretion of the anti-inflammatory and immunoregulatory cytokine interleukin 10 (IL-10) and decreases secretion of the proinflammatory cytokines tumour necrosis factor-α (TNF-α), IL-1 and IL-12. This may inhibit inflammation and contribute to impaired cell-mediated immunity in conditions associated with increased apoptosis, such as viral infections, pregnancy, cancer and exposure to radiation.

  18. Role of oxidative damage in toxicity of particulates

    DEFF Research Database (Denmark)

    Møller, Peter; Jacobsen, Nicklas R; Folkmann, Janne K;

    2010-01-01

    composition play important roles in the oxidative potential of particulates. Studies in animal models indicate that particles from combustion processes (generated by combustion of wood or diesel oil), silicate, titanium dioxide and nanoparticles (C60 fullerenes and carbon nanotubes) produce elevated levels...... of lipid peroxidation products and oxidatively damaged DNA. Biomonitoring studies in humans have shown associations between exposure to air pollution and wood smoke particulates and oxidative damage to DNA, deoxynucleotides and lipids measured in leukocytes, plasma, urine and/or exhaled breath. The results...

  19. Characterization of cyclin E expression in multiple myeloma and its functional role in seliciclib-induced apoptotic cell death.

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    Liat Josefsberg Ben-Yehoshua

    Full Text Available Multiple Myeloma (MM is a lymphatic neoplasm characterized by clonal proliferation of malignant plasma cell that eventually develops resistance to chemotherapy. Drug resistance, differentiation block and increased survival of the MM tumor cells result from high genomic instability. Chromosomal translocations, the most common genomic alterations in MM, lead to dysregulation of cyclin D, a regulatory protein that governs the activation of key cell cycle regulator--cyclin dependent kinase (CDK. Genomic instability was reported to be affected by over expression of another CDK regulator--cyclin E (CCNE. This occurs early in tumorigenesis in various lymphatic malignancies including CLL, NHL and HL. We therefore sought to investigate the role of cyclin E in MM. CCNE1 expression was found to be heterogeneous in various MM cell lines (hMMCLs. Incubation of hMMCLs with seliciclib, a selective CDK-inhibitor, results in apoptosis which is accompanied by down regulation of MCL1 and p27. Ectopic over expression of CCNE1 resulted in reduced sensitivity of the MM tumor cells in comparison to the paternal cell line, whereas CCNE1 silencing with siRNA increased the cell sensitivity to seliciclib. Adhesion to FN of hMMCLs was prevented by seliciclib, eliminating adhesion-mediated drug resistance of MM cells. Combination of seliciclib with flavopiridol effectively reduced CCNE1 and CCND1 protein levels, increased subG1 apoptotic fraction and promoted MM cell death in BMSCs co-culture conditions, therefore over-coming stroma-mediated protection. We suggest that seliciclib may be considered as essential component of modern anti MM drug combination therapy.

  20. Characterization of cyclin E expression in multiple myeloma and its functional role in seliciclib-induced apoptotic cell death.

    Science.gov (United States)

    Josefsberg Ben-Yehoshua, Liat; Beider, Katia; Shimoni, Avichai; Ostrovsky, Olga; Samookh, Michal; Peled, Amnon; Nagler, Arnon

    2012-01-01

    Multiple Myeloma (MM) is a lymphatic neoplasm characterized by clonal proliferation of malignant plasma cell that eventually develops resistance to chemotherapy. Drug resistance, differentiation block and increased survival of the MM tumor cells result from high genomic instability. Chromosomal translocations, the most common genomic alterations in MM, lead to dysregulation of cyclin D, a regulatory protein that governs the activation of key cell cycle regulator--cyclin dependent kinase (CDK). Genomic instability was reported to be affected by over expression of another CDK regulator--cyclin E (CCNE). This occurs early in tumorigenesis in various lymphatic malignancies including CLL, NHL and HL. We therefore sought to investigate the role of cyclin E in MM. CCNE1 expression was found to be heterogeneous in various MM cell lines (hMMCLs). Incubation of hMMCLs with seliciclib, a selective CDK-inhibitor, results in apoptosis which is accompanied by down regulation of MCL1 and p27. Ectopic over expression of CCNE1 resulted in reduced sensitivity of the MM tumor cells in comparison to the paternal cell line, whereas CCNE1 silencing with siRNA increased the cell sensitivity to seliciclib. Adhesion to FN of hMMCLs was prevented by seliciclib, eliminating adhesion-mediated drug resistance of MM cells. Combination of seliciclib with flavopiridol effectively reduced CCNE1 and CCND1 protein levels, increased subG1 apoptotic fraction and promoted MM cell death in BMSCs co-culture conditions, therefore over-coming stroma-mediated protection. We suggest that seliciclib may be considered as essential component of modern anti MM drug combination therapy.

  1. A dual role of Cdk2 in DNA damage response

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    Kaldis Philipp

    2009-05-01

    Full Text Available Abstract Once it was believed that Cdk2 was the master regulator of S phase entry. Gene knockout mouse studies of cell cycle regulators revealed that Cdk2 is dispensable for S phase initiation and progression whereby Cdk1 can compensate for the loss of Cdk2. Nevertheless, recent evidence indicates that Cdk2 is involved in cell cycle independent functions such as DNA damage repair. Whether these properties are unique to Cdk2 or also being compensated by other Cdks in the absence of Cdk2 is under extensive investigation. Here we review the emerging new role of Cdk2 in DNA damage repair and also discuss how the loss of Cdk2 impacts the G1/S phase DNA damage checkpoint.

  2. A dual role of Cdk2 in DNA damage response.

    Science.gov (United States)

    Satyanarayana, Ande; Kaldis, Philipp

    2009-05-18

    Once it was believed that Cdk2 was the master regulator of S phase entry. Gene knockout mouse studies of cell cycle regulators revealed that Cdk2 is dispensable for S phase initiation and progression whereby Cdk1 can compensate for the loss of Cdk2. Nevertheless, recent evidence indicates that Cdk2 is involved in cell cycle independent functions such as DNA damage repair. Whether these properties are unique to Cdk2 or also being compensated by other Cdks in the absence of Cdk2 is under extensive investigation. Here we review the emerging new role of Cdk2 in DNA damage repair and also discuss how the loss of Cdk2 impacts the G1/S phase DNA damage checkpoint.

  3. Temporal activation of anti- and pro-apoptotic factors in human gingival fibroblasts infected with the periodontal pathogen, Porphyromonas gingivalis: potential role of bacterial proteases in host signalling

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    Takehara Tadamichi

    2006-03-01

    Full Text Available Abstract Background Porphyromonas gingivalis is the foremost oral pathogen of adult periodontitis in humans. However, the mechanisms of bacterial invasion and the resultant destruction of the gingival tissue remain largely undefined. Results We report host-P. gingivalis interactions in primary human gingival fibroblast (HGF cells. Quantitative immunostaining revealed the need for a high multiplicity of infection for optimal infection. Early in infection (2–12 h, P. gingivalis activated the proinflammatory transcription factor NF-kappa B, partly via the PI3 kinase/AKT pathway. This was accompanied by the induction of cellular anti-apoptotic genes, including Bfl-1, Boo, Bcl-XL, Bcl2, Mcl-1, Bcl-w and Survivin. Late in infection (24–36 h the anti-apoptotic genes largely shut down and the pro-apoptotic genes, including Nip3, Hrk, Bak, Bik, Bok, Bax, Bad, Bim and Moap-1, were activated. Apoptosis was characterized by nuclear DNA degradation and activation of caspases-3, -6, -7 and -9 via the intrinsic mitochondrial pathway. Use of inhibitors revealed an anti-apoptotic function of NF-kappa B and PI3 kinase in P. gingivalis-infected HGF cells. Use of a triple protease mutant P. gingivalis lacking three major gingipains (rgpA rgpB kgp suggested a role of some or all these proteases in myriad aspects of bacteria-gingival interaction. Conclusion The pathology of the gingival fibroblast in P. gingivalis infection is affected by a temporal shift from cellular survival response to apoptosis, regulated by a number of anti- and pro-apoptotic molecules. The gingipain group of proteases affects bacteria-host interactions and may directly promote apoptosis by intracellular proteolytic activation of caspase-3.

  4. Antigenotoxic and Apoptotic Activity of Green Tea Polyphenol Extracts on Hexavalent Chromium-Induced DNA Damage in Peripheral Blood of CD-1 Mice: Analysis with Differential Acridine Orange/Ethidium Bromide Staining

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    María del Carmen García-Rodríguez

    2013-01-01

    Full Text Available This study was conducted to investigate the modulating effects of green tea polyphenols on genotoxic damage and apoptotic activity induced by hexavalent chromium [Cr (VI] in CD-1 mice. Animals were divided into the following groups: (i injected with vehicle; (ii treated with green tea polyphenols (30 mg/kg via gavage; (iii injected with CrO3 (20 mg/kg intraperitoneally; (iv treated with green tea polyphenols in addition to CrO3. Genotoxic damage was evaluated by examining micronucleated polychromatic erythrocytes (MN-PCEs obtained from peripheral blood at 0, 24, 48, and 72 h after treatment. Induction of apoptosis and cell viability were assessed by differential acridine orange/ethidium bromide (AO/EB staining. Treatment of green tea polyphenols led to no significant changes in the MN-PCEs. However, CrO3 treatment significantly increased MN-PCEs at 24 and 48 h after injection. Green tea polyphenols treatment prior to CrO3 injection led to a decrease in MN-PCEs compared to the group treated with CrO3 only. The average of apoptotic cells was increased at 48 h after treatment compared to control mice, suggesting that apoptosis could contribute to eliminate the DNA damaged cells induced by Cr (VI. Our findings support the proposed protective effects of green tea polyphenols against the genotoxic damage induced by Cr (VI.

  5. Role of metallothionein-III following central nervous system damage

    DEFF Research Database (Denmark)

    Carrasco, Javier; Penkowa, Milena; Giralt, Mercedes

    2003-01-01

    We evaluated the physiological relevance of metallothionein-III (MT-III) in the central nervous system following damage caused by a focal cryolesion onto the cortex by studying Mt3-null mice. In normal mice, dramatic astrogliosis and microgliosis and T-cell infiltration were observed in the area...... the inflammatory response elicited in the central nervous system by a cryoinjury, nor does it serve an important antioxidant role, but it may influence neuronal regeneration during the recovery process....

  6. The role of macrophages in the removal of apoptotic B-cells in the sheep ileal Peyer's patch.

    Science.gov (United States)

    Bhogal, Hardeep S; Kennedy, Laurie J; Babic, Kelly; Reynolds, John D

    2004-06-01

    In the process of generating the cells that populate the sheep's B-cell pool, the ileal Peyer's patch (PP) produces an immense number of B-cells and then destroys most of them by apoptosis. Rapid clearance of these apoptotic cells is essential for tissue homeostasis and for preventing pathology. Macrophages comprise a small percentage of cells in the follicles. They resemble macrophages found in other tissues and can be identified by the expression of MHC Class II and CD14. In this study, enriched macrophages co-cultured with apoptotic ileal PP cells showed increased DNA content as they ingested apoptotic cells. The higher the proportion of apoptotic cells in culture the greater the increase in DNA content of the macrophages. This occurred when B-cell apoptosis was initiated by a period in culture or in response to treating the animals with steroids. Thus, macrophages resident in the ileal PP follicle mediate the phagocytosis and removal of discarded B-cells.

  7. Roles of RNA-Binding Proteins in DNA Damage Response

    Directory of Open Access Journals (Sweden)

    Mihoko Kai

    2016-02-01

    Full Text Available Living cells experience DNA damage as a result of replication errors and oxidative metabolism, exposure to environmental agents (e.g., ultraviolet light, ionizing radiation (IR, and radiation therapies and chemotherapies for cancer treatments. Accumulation of DNA damage can lead to multiple diseases such as neurodegenerative disorders, cancers, immune deficiencies, infertility, and also aging. Cells have evolved elaborate mechanisms to deal with DNA damage. Networks of DNA damage response (DDR pathways are coordinated to detect and repair DNA damage, regulate cell cycle and transcription, and determine the cell fate. Upstream factors of DNA damage checkpoints and repair, “sensor” proteins, detect DNA damage and send the signals to downstream factors in order to maintain genomic integrity. Unexpectedly, we have discovered that an RNA-processing factor is involved in DNA repair processes. We have identified a gene that contributes to glioblastoma multiforme (GBM’s treatment resistance and recurrence. This gene, RBM14, is known to function in transcription and RNA splicing. RBM14 is also required for maintaining the stem-like state of GBM spheres, and it controls the DNA-PK-dependent non-homologous end-joining (NHEJ pathway by interacting with KU80. RBM14 is a RNA-binding protein (RBP with low complexity domains, called intrinsically disordered proteins (IDPs, and it also physically interacts with PARP1. Furthermore, RBM14 is recruited to DNA double-strand breaks (DSBs in a poly(ADP-ribose (PAR-dependent manner (unpublished data. DNA-dependent PARP1 (poly-(ADP ribose polymerase 1 makes key contributions in the DNA damage response (DDR network. RBM14 therefore plays an important role in a PARP-dependent DSB repair process. Most recently, it was shown that the other RBPs with intrinsically disordered domains are recruited to DNA damage sites in a PAR-dependent manner, and that these RBPs form liquid compartments (also known as

  8. The Anti-Apoptotic Role of Berberine in Preimplantation Embryo In Vitro Development through Regulation of miRNA-21.

    Science.gov (United States)

    Zhang, Chao; Shi, Ya-Ran; Liu, Xiao-Ran; Cao, Yong-Chun; Zhen, Di; Jia, Zi-Ye; Jiang, Jin-Qi; Tian, Jian-Hui; Gao, Jian-Ming

    2015-01-01

    Traditional Chinese medicinal herbs containing berberine have been historically used to prevent miscarriage. Here, we investigated whether the anti-apoptotic effects of berberine on pre-implantation embryonic development are regulated by miRNA-21. Mouse pronuclear embryos were cultured in medium with or without berberine, and some were then microinjected with a miRNA-21 inhibitor. The in vitro developmental rates of 2- and 4-cell embryos and blastocysts, blastocyst cell numbers, apoptotic rates, and apoptotic cell numbers were measured in each group. Furthermore, we examined the transcription levels of miRNA-21 and its target genes (caspase-3, PTEN, and Bcl-2) and their translation levels. Comparisons were made with in vivo-developed and untreated embryos. We found that berberine significantly increased the developmental rates and cell numbers of mouse blastocysts and decreased apoptotic cell rates in vitro. Berberine also significantly increased miRNA-21 and Bcl-2 transcription levels and significantly decreased caspase-3 and PTEN transcription levels. In embryos treated with a miRNA-21 inhibitor, the results followed the opposite trend; PTEN and caspase-3 transcription levels increased significantly, while the transcription level of Bcl-2 decreased significantly. Additionally, berberine treatment significantly increased the Bcl-2 protein level and significantly decreased the caspase-3 and PTEN protein levels in blastocysts, but there were no significant differences observed in the levels of these proteins in 2- and 4-cell embryos. This study revealed that miRNA-21 is important for pre-implantation embryonic development, especially blastocyst development in vitro. Berberine elevates miRNA-21 expression, decreases PTEN and caspase-3 levels, increases Bcl-2 levels, and exerts anti-apoptotic and pro-growth effects.

  9. Secretomes of apoptotic mononuclear cells ameliorate neurological damage in rats with focal ischemia [v2; ref status: indexed, http://f1000r.es/4kv

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    Patrick Altmann

    2014-10-01

    Full Text Available The pursuit of targeting multiple pathways in the ischemic cascade of cerebral stroke is a promising treatment option. We examined the regenerative potential of conditioned medium derived from rat and human apoptotic mononuclear cells (MNC, rMNCapo sec and hMNCapo sec, in experimental stroke. We performed middle cerebral artery occlusion on Wistar rats and administered apoptotic MNC-secretomes intraperitoneally in two experimental settings. Ischemic lesion volumes were determined 48 hours after cerebral ischemia. Neurological evaluations were performed after 6, 24 and 48 hours. Immunoblots were conducted to analyze neuroprotective signal-transduction in human primary glia cells and neurons. Neuronal sprouting assays were performed and neurotrophic factors in both hMNCapo sec and rat plasma were quantified using ELISA. Administration of rat as well as human apoptotic MNC-secretomes significantly reduced ischemic lesion volumes by 36% and 37%, respectively. Neurological examinations revealed improvement after stroke in both treatment groups. Co-incubation of human astrocytes, Schwann cells and neurons with hMNCapo sec resulted in activation of several signaling cascades associated with the regulation of cytoprotective gene products and enhanced neuronal sprouting in vitro. Analysis of neurotrophic factors in hMNCapo sec and rat plasma revealed high levels of brain derived neurotrophic factor (BDNF. Our data indicate that apoptotic MNC-secretomes elicit neuroprotective effects on rats that have undergone ischemic stroke.

  10. Role of mitochondrial damage during cardiac apoptosis in septic rats

    Institute of Scientific and Technical Information of China (English)

    LI Li; HU Bang-chuan; CHEN Chang-qin; GONG Shi-jin; YU Yi-hua; DAI Hai-wen; YAN Jing

    2013-01-01

    Background Myocardial apoptosis is involved in the pathogenesis of sepsis-related myocardial depression.However,the underlying mechanism remains unknown.This study investigated the role of mitochondrial damage and mitochondria-induced oxidative stress during cardiac apoptosis in septic rats.Methods Seventy-two Sprague-Dawley rats were randomly divided into a control group and septic group receiving lipopolysaccharide injection.Heart tissue was removed and changes in cardiac morphology were observed by light microscopy and scanning electron microscopy.In situ apoptosis was examined using terminal transferase-mediated dUTP nick end-labeling assay and nuclear factor-kappa B activation in myocardium by Western blotting to estimate myocardial apoptosis.Appearance of mitochondrial cristae and activation of cytochrome C oxidase were used to evaluate mitochondrial damage.Oxidative stress was assessed by mitochondrial lipid and protein oxidation,and antioxidant defense was assessed by mitochondrial superoxide dismutase and glutathione peroxidase activity.Results Sepsis-induced inflammatory cell infiltration,myocardium degeneration and dropsy were time-dependent.Expanded capillaries were observed in the hearts of infected rats 24 hours post-challenge.Compared with sham-treated rats,the percentage of cell apoptosis increased in a time-dependent manner in hearts from septic rats at 6 hours,12 hours and 24 hours post-injection (P < 0.05).The expression of nuclear factor-kappa B p65 decreased gradually in the cytosol and increased in the nucleus during sepsis,indicating that septic challenge provoked the progressive activation of nuclear factor-kappa B.Mitochondrial cristae and activation of cytochrome C oxidase increased in a time-dependent manner.Both superoxide dismutase and glutathione peroxidase activities decreased,while mitochondrial lipid and protein oxidation increased between 6 and 24 hours after lipopolysaccharide challenge.Conclusions Septic challenge induced

  11. Phosphine-induced oxidative damage in rats: role of glutathione.

    Science.gov (United States)

    Hsu, Ching-Hung; Chi, Bei-Ching; Liu, Ming-Yie; Li, Jih-Heng; Chen, Chiou-Jong; Chen, Ruey-Yu

    2002-09-30

    Phosphine (PH(3)), generated from aluminium, magnesium and zinc phosphide, is a widely used pesticide. PH(3) induces oxidative stress in insects, mammalian cells, animals, and humans. The involvement of glutathione (GSH) in PH(3)-induced oxidative toxicity is controversial. GSH levels in various tested tissues were reduced in aluminium phosphide-poisoned rats and humans, while the levels remained unchanged in insects and mammalian cells. This study examines the effectiveness of endogenous GSH as a protective agent against PH(3)-induced oxidative damage in rats. The association of PH(3)-induced nephrotoxicity and cardiotoxicity with free radical production was also tested. Male Wistar rats, administered intraperitoneally (I.P.) with PH(3) at 4 mg/kg, were evaluated 30 min after treatment for PH(3) toxicity to organs. PH(3) significantly decreased GSH, GSH peroxidase and catalase, while significantly increased lipid peroxidation (as malondialdehyde and 4-hydroxyalkenals), DNA oxidation (as 8-hydroxydeoxyguaonsoine) and superoxide dismutase (SOD) levels in kidney and heart. These changes were significantly alleviated by melatonin (10 mg/kg I.P., 30 min before PH(3)), with the exception of SOD activity in heart tissue. The study also found that buthionine sulfoximine (1 g/kg I.P., 24 h before PH(3)) significantly enhanced the effect of PH(3) on GSH loss and lipid peroxidation elevation in lung. These findings indicate that (1) endogenous GSH plays a crucial role as a protective factor in modulating PH(3)-induced oxidative damage, and (2) PH(3) could injure kidney and heart (as noted earlier with brain, liver and lung) via oxidative stress and the antioxidant melatonin effectively prevents the damage.

  12. Role of the mitochondria in immune-mediated apoptotic death of the human pancreatic β cell line βLox5.

    Directory of Open Access Journals (Sweden)

    Yaíma L Lightfoot

    Full Text Available Mitochondria are indispensable in the life and death of many types of eukaryotic cells. In pancreatic beta cells, mitochondria play an essential role in the secretion of insulin, a hormone that regulates blood glucose levels. Unregulated blood glucose is a hallmark symptom of diabetes. The onset of Type 1 diabetes is preceded by autoimmune-mediated destruction of beta cells. However, the exact role of mitochondria has not been assessed in beta cell death. In this study, we examine the role of mitochondria in both Fas- and proinflammatory cytokine-mediated destruction of the human beta cell line, βLox5. IFNγ primed βLox5 cells for apoptosis by elevating cell surface Fas. Consequently, βLox5 cells were killed by caspase-dependent apoptosis by agonistic activation of Fas, but only after priming with IFNγ. This beta cell line undergoes both apoptotic and necrotic cell death after incubation with the combination of the proinflammatory cytokines IFNγ and TNFα. Additionally, both caspase-dependent and -independent mechanisms that require proper mitochondrial function are involved. Mitochondrial contributions to βLox5 cell death were analyzed using mitochondrial DNA (mtDNA depleted βLox5 cells, or βLox5 ρ(0 cells. βLox5 ρ(0 cells are not sensitive to IFNγ and TNFα killing, indicating a direct role for the mitochondria in cytokine-induced cell death of the parental cell line. However, βLox5 ρ(0 cells are susceptible to Fas killing, implicating caspase-dependent extrinsic apoptotic death is the mechanism by which these human beta cells die after Fas ligation. These data support the hypothesis that immune mediators kill βLox5 cells by both mitochondrial-dependent intrinsic and caspase-dependent extrinsic pathways.

  13. Late activation of apoptotic pathways plays a negligible role in mediating the cytotoxic effects of discodermolide and epothilone B in non-small cell lung cancer cells.

    Science.gov (United States)

    Bröker, Linda E; Huisman, Cynthia; Ferreira, Carlos G; Rodriguez, José A; Kruyt, Frank A E; Giaccone, Giuseppe

    2002-07-15

    Discodermolide and epothilone B are promising novel chemotherapeutic agentsthat induce cell death through potent stabilization of microtubules. In this study, we investigated the cellular and molecular events underlying the cytotoxicity of these drugs in non-small cell lung carcinoma (NSCLC) cell lines, focusing on apoptotic characteristics. IC80 concentrations of either drug effectively disrupted the microtubule cytoskeleton of H460 cells and induced cell cycle disturbances with early accumulation in the G2-M phase and development of a hypodiploid cell population in both H460 and SW1573 cells. These events were followed by abnormal chromosome segregation during mitosis and subsequent appearance of multinucleated cells. At later time points, the cells displayed several apoptotic features, such as nuclear condensation and fragmentation as well as Annexin V staining, cleavage of poly(ADP-ribose) polymerase and the activation of caspases. To examine the contribution of apoptotic pathways to the cytotoxic effects of these agents, the involvement of the mitochondria and death receptor routes was studied. At 48 h after treatment, both agents disrupted mitochondria of H460 cells, as indicated by cytochrome c release. Nonetheless, H460 cells stably overexpressing antiapoptotic Bcl-2 or Bcl-xL did not show any protective effect from cell death induced by either drug. Possible death receptor dependency was investigated in H460 cells stably overexpressing dominant-negative FADD, which failed to reduce the cytotoxic effects of discodermolide and epothilone B. To study the role of caspases more directly, the effect of stable overexpression of the caspase-8 inhibitor cytokine response modifier A was studied in H460 cells. Furthermore, the effect of the pancaspase inhibitor z-Val-Ala-Asp-fluoromethyl ketone was investigated in a panel of lung carcinoma cell lines. Interestingly, caspase inhibition did not rescue cells from discodermolide or epothilone B-induced cell death. In

  14. The role of antigen specificity in the binding of murine monoclonal anti-DNA antibodies to microparticles from apoptotic cells.

    Science.gov (United States)

    Ullal, Anirudh J; Marion, Tony N; Pisetsky, David S

    2014-10-01

    Antibodies to DNA (anti-DNA) are the serological hallmark of systemic lupus erythematosus and markers of underlying immune system disturbances. These antibodies bind to both single-stranded and double-stranded DNA, mediating pathogenesis by forming immune complexes. As shown recently, DNA in blood exists in both free and particulate forms, with DNA representing an important component of microparticles. Microparticles are membrane-bound vesicles containing nuclear molecules, released by membrane blebbing during cell death and activation. A panel of monoclonal NZB/NZW F1 anti-DNA antibodies was tested for binding to microparticles generated from apoptotic THP-1 and Jurkat cells. These studies showed that only certain anti-DNA antibodies in the panel, specific for double-stranded DNA, bound to microparticles. Binding to particles was reduced by soluble DNA or DNase treatment. Together, these results indicate that particle binding is a feature of only certain anti-DNA antibodies, reflecting immunochemical properties of the antibodies and the nature of the exposed DNA antigens.

  15. Reactive oxygen species are related to ionic fluxes and volume decrease in apoptotic cerebellar granule neurons: role of NOX enzymes.

    Science.gov (United States)

    Hernández-Enríquez, Berenice; Guemez-Gamboa, Alicia; Morán, Julio

    2011-05-01

    Reactive oxygen species (ROS) are produced early during apoptosis of cerebellar granule neurons induced by low potassium (K5) and staurosporine (Sts). In addition, K5 and Sts activate NADPH oxidases (NOX). Recently, we described that K5 and Sts induce apoptotic volume decrease (AVD) at a time when ROS generation and NOX activity occur. In the present study, we evaluated the relationship between ROS generation and ionic fluxes during AVD. Here, we showed that K5- and Sts-induced AVD was inhibited by antioxidants and that direct ROS production induced AVD. Moreover, NOX inhibitors eliminated AVD induced by both K5 and Sts. Sts, but not K5, failed to induce AVD in cerebellar granule neurons from NOX2 knockout mice. These findings suggest that K5- and Sts-induced AVD is largely mediated by ROS produced by NOX. On the other hand, we also found that the blockage of ionic fluxes involved in AVD inhibited both ROS generation and NOX activity. These findings suggest that ROS generation and NOX activity are involved in ionic fluxes activation, which in turn could maintain ROS generation by activating NOX, leading to a self-amplifying cycle.

  16. Critical roles of cellular glutathione homeostasis and jnk activation in andrographolide-mediated apoptotic cell death in human hepatoma cells.

    Science.gov (United States)

    Ji, Lili; Shen, Kaikai; Jiang, Ping; Morahan, Grant; Wang, Zhengtao

    2011-08-01

    Andrographolide (ANDRO), isolated from the traditional herbal medicine Andrographis paniculata, is reported to have the potential therapeutic effects for hepatocellular carcinoma (HCC) in our previous reports. Here, we investigated the mechanism of ANDRO-mediated apoptotic cell death, focusing on the involvement of cellular reduced glutathione (GSH) homeostasis and c-Jun NH(2) -Terminal kinase (JNK). Buthionine sulfoximine (BSO), an inhibitor of cellular GSH biosynthesis, significantly augmented ANDRO-induced cytotoxicity in hepatoma Hep3B and HepG2 cells. BSO depleted cellular GSH, and augmented ANDRO-induced apoptosis, inhibition of colony formation and JNK activation in Hep3B cells. All these effects could be reversed by GSH monoethyl ester (GSH.EE), whose deacetylation replenishes cellular GSH. BSO also augmented ANDRO-induced activation of apoptosis signal-regulating kinase 1 (ASK1), mitogen-activated protein kinase kinase-4 (MKK4) and c-Jun, which are all up-stream or down-stream signals of JNK. Further results showed that JNK inhibitor SP600125 and 420116 both reversed ANDRO-induced cytotoxicity, and SP600125 also decreased ANDRO-increased intracellular GSH and GCL activity. Finally, we showed that in nude mice bearing xenografted Hep3B tumors, BSO improved the inhibition of tumor growth by ANDRO. Taken together, our results suggest that there is a crosstalk between JNK activation and cellular GSH homeostasis, and ANDRO targets this to induce cytotoxicity in hepatoma cells.

  17. Roles of chlorophyllin in cell proliferation and the expression of apoptotic and cell cycle genes in HB4a non-tumor breast cells.

    Science.gov (United States)

    D Epiro, Gláucia Fernanda Rocha; Semprebon, Simone Cristine; Niwa, Andressa Megumi; Marcarini, Juliana Cristina; Mantovani, Mário Sérgio

    2016-06-01

    Chlorophyllin (Chl) has attracted interest in the scientific community due to its chemopreventive and antimutagenic properties. However, the molecular mechanisms of action of Chl remain unclear. This study assesses the effects on cell proliferation and the expression of genes involved in apoptosis, and the cell cycle in HB4a cells treated with Chl. Chl was cytotoxic and induced apoptosis to HB4a cells at 400 μg/mL. Analysis of gene expression showed that there was a decrease in the mRNA level of BIRC5 and CCNA2 genes involved in apoptosis and cell cycle progression, respectively. The proapoptotic gene BAX and the antiapoptotic genes BCL-2 and BCL-XL were upregulated. The cytotoxicity of Chl has been attributed to increases in the expression of BAX and decreases in the expression of genes involved in the cell cycle, but increases in the expression of anti-apoptotic genes suggests a mechanism for protection from cell death induced by Chl. This study provides important information about mechanisms that protect against or trigger damaging processes in non-tumor cells.

  18. Spink2 modulates apoptotic susceptibility and is a candidate gene in the Rgcs1 QTL that affects retinal ganglion cell death after optic nerve damage.

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    Joel A Dietz

    Full Text Available The Rgcs1 quantitative trait locus, on mouse chromosome 5, influences susceptibility of retinal ganglion cells to acute damage of the optic nerve. Normally resistant mice (DBA/2J congenic for the susceptible allele from BALB/cByJ mice exhibit susceptibility to ganglion cells, not only in acute optic nerve crush, but also to chronic inherited glaucoma that is characteristic of the DBA/2J strain as they age. SNP mapping of this QTL has narrowed the region of interest to 1 Mb. In this region, a single gene (Spink2 is the most likely candidate for this effect. Spink2 is expressed in retinal ganglion cells and is increased after optic nerve damage. This gene is also polymorphic between resistant and susceptible strains, containing a single conserved amino acid change (threonine to serine and a 220 bp deletion in intron 1 that may quantitatively alter endogenous expression levels between strains. Overexpression of the different variants of Spink2 in D407 tissue culture cells also increases their susceptibility to the apoptosis-inducing agent staurosporine in a manner consistent with the differential susceptibility between the DBA/2J and BALB/cByJ strains.

  19. Biological evaluation of a cytotoxic 2-substituted benzimidazole copper(II) complex: DNA damage, antiproliferation and apoptotic induction activity in human cervical cancer cells.

    Science.gov (United States)

    Qiao, Xin; Ma, Zhong-Ying; Shao, Jia; Bao, Wei-Guo; Xu, Jing-Yuan; Qiang, Zhao-Yan; Lou, Jian-Shi

    2014-02-01

    Exploring novel chemotherapeutic agents is a great challenge in cancer medicine. To that end, 2-substituted benzimidazole copper(II) complex, [Cu(BMA)Cl2]·(CH3OH) (1) [BMA = N,N'-bis(benzimidazol-2-yl-methyl)amine], was synthesized and its cytotoxicity was characterized. The interaction between complex 1 and calf thymus DNA was detected by spectroscopy methods. The binding constant (K b = 1.24 × 10(4 )M(-1)) and the apparent binding constant (K app = 6.67 × 10(6 )M(-1)) of 1 indicated its moderate DNA affinity. Complex 1 induced single strand breaks of pUC19 plasmid DNA in the presence of H2O2 through an oxidative pathway. Cytotoxicity studies proved that complex 1 could inhibit the proliferation of human cervical carcinoma cell line HeLa in both time- and dose-dependent manners. The results of nuclei staining by Hoechst 33342 and alkaline single-cell gel electrophoresis proved that complex 1 caused cellular DNA damage in HeLa cells. Furthermore, treatment of HeLa cells with 1 resulted in S-phase arrest, loss of mitochondrial potential, and up-regulation of caspase-3 and -9 in HeLa cells, suggesting that complex 1 was capable of inducing apoptosis in cancer cells through the intrinsic mitochondrial pathway.

  20. Pro-apoptotic role of NF-κB pathway inhibition in lipopolysaccharide-stimulated polymorphonuclear neutrophils

    Institute of Scientific and Technical Information of China (English)

    刘艳梅; 张君岚; 赵占胜; 凌亦凌

    2003-01-01

    Objective To investigate the role of nuclear factor kappa B (NF-κB) pathway inhibition in lipopolysaccharide (LPS)-stimulated apoptosis of polymorphonuclear neutrophils (PMNs).Methods Rats with acute lung injury induced by LPS intratracheal instillation and cultured human venous PMNs were studied. Pyrrolidine dithiocarbamate (PDTC) and gliotoxin were used as NF-κB inhibitors. Additionally, to explore the role of extracellularly regulated protein kinase as an upstream signal in NF-κB pathway on regulating LPS-stimulated PMN apoptosis, PD098059, the specific inhibitor of extracellularly regulated protein kinase, was also applied. The lung injury was determined by protein content and PMN numbers in bronchoalveolar lavage fluid. PMN apoptosis was measured by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP) end labeling and DNA fragmentation. IκBα degradation was analyzed by Western blot. NF-κB DNA binding activity was detected by an electrophoretic mobility shift assay.Results (1) The increase of protein content and PMN numbers in bronchoalveolar lavage fluid induced by LPS (100 μg per rat) intratracheal instillation were alleviated by PDTC (50, 100, or 200 mg/kg, I.p.) in a dose-dependent manner. (2) PMNs apoptosis in vivo or in vitro was delayed by LPS, and accelerated by PDTC, gliotoxin or PD098059 pretreatment. (3) IκBα degradation and increased NF-κB DNA binding activity mediated by LPS were inhibited by PDTC, gliotoxin or PD098059 pretreatment.Conclusion Inhibition of either NF-κB itself or the upstream signals in NF-κB pathway such as extracellularly regulated protein kinases has therapeutic effect on LPS-induced acute lung injury, in which the dysregulation of PMN apoptosis plays an important role.

  1. An evidence on G2/M arrest, DNA damage and caspase mediated apoptotic effect of biosynthesized gold nanoparticles on human cervical carcinoma cells (HeLa)

    Energy Technology Data Exchange (ETDEWEB)

    Jeyaraj, M. [Department of Biotechnology and Genetic Engineering, School of Biotechnology, Bharathidasan University, Tiruchirappalli 620024, Tamil Nadu (India); Arun, R. [Department of Biomedical Sciences, Bharathidasan University, Tiruchirappalli 620024 (India); Sathishkumar, G. [Department of Biotechnology and Genetic Engineering, School of Biotechnology, Bharathidasan University, Tiruchirappalli 620024, Tamil Nadu (India); MubarakAli, D. [Central Inter-Disciplinary Research Facility, Mahatma Gandhi Medical College and Research Institute Campus, Pondicherry 607402 (India); Rajesh, M.; Sivanandhan, G.; Kapildev, G.; Manickavasagam, M. [Department of Biotechnology and Genetic Engineering, School of Biotechnology, Bharathidasan University, Tiruchirappalli 620024, Tamil Nadu (India); Thajuddin, N. [Department of Microbiology, Bharathidasan University, Tiruchirappalli 620024 (India); Ganapathi, A., E-mail: aganapathi2007@gmail.com [Department of Biotechnology and Genetic Engineering, School of Biotechnology, Bharathidasan University, Tiruchirappalli 620024, Tamil Nadu (India)

    2014-04-01

    Highlights: • Gold nanoparticles (AuNPs) have been synthesized using Podophyllum hexandrum L. • AuNPs induces the oxidative stress to cell death in human cervical carcinoma cells. • It activates the caspase-cascade to cellular death. • It is actively blocks G2/M phase of cell cycle. - Abstract: Current prospect of nanobiotechnology involves in the greener synthesis of nanostructured materials particularly noble metal nanoparticles for various biomedical applications. In this study, biologically (Podophyllum hexandrum L.) synthesized crystalline gold nanoparticles (AuNPs) with the size range between 5 and 35 nm were screened for its anticancereous potential against human cervical carcinoma cells (HeLa). Stoichiometric proportion of the reaction mixture and conditions were optimized to attain stable nanoparticles with narrow size range. Different high throughput techniques like transmission electron microscope (TEM), X-ray diffraction (XRD) and UV–vis spectroscopy were adopted for the physio-chemical characterization of AuNPs. Additionally, Fourier transform infrared spectroscopy (FTIR) study revealed that the water soluble fractions present in the plant extract solely influences the reduction of AuNPs. Sublimely, synthesized AuNPs exhibits an effective in vitro anticancer activity against HeLa cells via induction of cell cycle arrest and DNA damage. Furthermore, it was evidenced that AuNPs treated cells are undergone apoptosis through the activation of caspase cascade which subsequently leads to mitochondrial dysfunction. Thereby, this study proves that biogenic colloidal AuNPs can be developed as a promising drug candidature for human cervical cancer therapy.

  2. Potential role of punicalagin against oxidative stress induced testicular damage

    Directory of Open Access Journals (Sweden)

    Faiza Rao

    2016-01-01

    Full Text Available Punicalagin is isolated from pomegranate and widely used for the treatment of different diseases in Chinese traditional medicine. This study aimed to evaluate the effect of Punicalagin (purity ≥98% on oxidative stress induced testicular damage and its effect on fertility. We detected the antioxidant potential of punicalagin in lipopolysaccharide (LPS induced oxidative stress damage in testes, also tried to uncover the boosting fertility effect of Punicalagin (PU against oxidative stress-induced infertility. Results demonstrated that 9 mg kg−1 for 7 days treatment significantly decreases LPS induced oxidative damage in testes and nitric oxide production. The administration of oxidative stress resulted in a significant reduction in testes antioxidants GSH, T-SOD, and CAT raised LPO, but treatment with punicalagin for 7 days increased antioxidant defense GSH, T-SOD, and CAT by the end of the experiment and reduced LPO level as well. PU also significantly activates Nrf2, which is involved in regulation of antioxidant defense systems. Hence, the present research categorically elucidates the protective effect of punicalagin against LPS induced oxidative stress induced perturbation in the process of spermatogenesis and significantly increased sperm health and number. Moreover, fertility success significantly decreased in LPS-injected mice compared to controls. Mice injected with LPS had fertility indices of 12.5%, while others treated with a combination of PU + LPS exhibited 75% indices. By promoting fertility and eliminating oxidative stress and inflammation, PU may be a useful nutrient for the treatment of infertility.

  3. Critical role of p53 upregulated modulator of apoptosis in benzyl isothiocyanate-induced apoptotic cell death.

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    Marie Lue Antony

    Full Text Available Benzyl isothiocyanate (BITC, a constituent of edible cruciferous vegetables, decreases viability of cancer cells by causing apoptosis but the mechanism of cell death is not fully understood. The present study was undertaken to determine the role of Bcl-2 family proteins in BITC-induced apoptosis using MDA-MB-231 (breast, MCF-7 (breast, and HCT-116 (colon human cancer cells. The B-cell lymphoma 2 interacting mediator of cell death (Bim protein was dispensable for proapoptotic response to BITC in MCF-7 and MDA-MB-231 cells as judged by RNA interference studies. Instead, the BITC-treated MCF-7 and MDA-MB-231 cells exhibited upregulation of p53 upregulated modulator of apoptosis (PUMA protein. The BITC-mediated induction of PUMA was relatively more pronounced in MCF-7 cells due to the presence of wild-type p53 compared with MDA-MB-231 with mutant p53. The BITC-induced apoptosis was partially but significantly attenuated by RNA interference of PUMA in MCF-7 cells. The PUMA knockout variant of HCT-116 cells exhibited significant resistance towards BITC-induced apoptosis compared with wild-type HCT-116 cells. Attenuation of BITC-induced apoptosis in PUMA knockout HCT-116 cells was accompanied by enhanced G2/M phase cell cycle arrest due to induction of p21 and down regulation of cyclin-dependent kinase 1 protein. The BITC treatment caused a decrease in protein levels of Bcl-xL (MCF-7 and MDA-MB-231 cells and Bcl-2 (MCF-7 cells. Ectopic expression of Bcl-xL in MCF-7 and MDA-MB-231 cells and that of Bcl-2 in MCF-7 cells conferred protection against proapoptotic response to BITC. Interestingly, the BITC-treated MDA-MB-231 cells exhibited induction of Bcl-2 protein expression, and RNA interference of Bcl-2 in this cell line resulted in augmentation of BITC-induced apoptosis. The BITC-mediated inhibition of MDA-MB-231 xenograft growth in vivo was associated with the induction of PUMA protein in the tumor. In conclusion, the results of the present study

  4. Roles of histone ubiquitylation in DNA damage signaling

    Institute of Scientific and Technical Information of China (English)

    Sui-Sui DONG; Michael S. Y. HUEN

    2011-01-01

    Histone ubiquitylation has emerged as an important chromatin modification associated with DNA damage signaling and repair pathways.These histone marks,laid down by E3 ubiquitin ligases that include RNF8 and RNF168,decorate chromatin domains surrounding DNA double-strand breaks (DSBs).Recent work implicated ubiquitylated histones in orchestrating cell cycle checkpoints,DNA repair and gene transcription.Here we summarize recent advances that contribute to our current knowledge of the highly dynamic nature of DSB-associated histone ubiquitylation,and discuss major challenges ahead in understanding the versatility of ubiquitin conjugation in maintaining genome stability.

  5. Role of New Biomarkers: Functional and Structural Damage

    Directory of Open Access Journals (Sweden)

    Evdoxia Tsigou

    2013-01-01

    Full Text Available Traditional diagnosis of acute kidney injury (AKI depends on detection of oliguria and rise of serum creatinine level, which is an unreliable and delayed marker of kidney damage. Delayed diagnosis of AKI in the critically ill patient is related to increased morbidity and mortality, prolonged length of stay, and cost escalation. The discovery of a reliable biomarker for early diagnosis of AKI would be very helpful in facilitating early intervention, evaluating the effectiveness of therapy, and eventually reducing cost and improving outcome. Innovative technologies such as genomics and proteomics have contributed to the discovery of new biomarkers, such as neutrophil gelatinase-associated lipocalin (NGAL, cystatin C (Cys C, kidney injury molecule-1 (KIM-1, interleukin-18 (IL-18, and liver-type fatty acid binding protein (L-FABP. The current status of the most promising of these novel AKI biomarkers, including NGAL, Cys C, KIM-1, L-FABP, and IL-18, is reviewed.

  6. Role of Oxidative Damage in Radiation-Induced Bone Loss

    Science.gov (United States)

    Schreurs, Ann-Sofie; Alwood, Joshua S.; Limoli, Charles L.; Globus, Ruth K.

    2014-01-01

    During prolonged spaceflight, astronauts are exposed to both microgravity and space radiation, and are at risk for increased skeletal fragility due to bone loss. Evidence from rodent experiments demonstrates that both microgravity and ionizing radiation can cause bone loss due to increased bone-resorbing osteoclasts and decreased bone-forming osteoblasts, although the underlying molecular mechanisms for these changes are not fully understood. We hypothesized that excess reactive oxidative species (ROS), produced by conditions that simulate spaceflight, alter the tight balance between osteoclast and osteoblast activities, leading to accelerated skeletal remodeling and culminating in bone loss. To test this, we used the MCAT mouse model; these transgenic mice over-express the human catalase gene targeted to mitochondria, the major organelle contributing free radicals. Catalase is an anti-oxidant that converts reactive species, hydrogen peroxide into water and oxygen. This animal model was selected as it displays extended lifespan, reduced cardiovascular disease and reduced central nervous system radio-sensitivity, consistent with elevated anti-oxidant activity conferred by the transgene. We reasoned that mice overexpressing catalase in mitochondria of osteoblast and osteoclast lineage cells would be protected from the bone loss caused by simulated spaceflight. Over-expression of human catalase localized to mitochondria caused various skeletal phenotypic changes compared to WT mice; this includes greater bone length, decreased cortical bone area and moment of inertia, and indications of altered microarchitecture. These findings indicate mitochondrial ROS are important for normal bone-remodeling and skeletal integrity. Catalase over-expression did not fully protect skeletal tissue from structural decrements caused by simulated spaceflight; however there was significant protection in terms of cellular oxidative damage (MDA levels) to the skeletal tissue. Furthermore, we

  7. A putative role of Drep1 in apoptotic DNA fragmentation system in fly is mediated by direct interaction with Drep2 and Drep4.

    Science.gov (United States)

    Park, Ok Kyung; Park, Hyun Ho

    2013-04-01

    DNA fragmentation is common phenomenon for apoptotic cell death. DNA fragmentation factor, called DFF40 (CAD: mouse homologue), is a main nuclease for apoptotic DNA fragmentation. Nuclease activity of DFF40 is normally inhibited by DFF45 by tight interaction via CIDE domain without apoptotic stimuli. Once effector caspase is activated during apoptosis signaling, it cleave DFF45, allowing DFF40 to enter the nucleus and cleave chromosomal DNA. Unlike mammalian system, apoptotic DNA fragmentation in the fly might be controlled by four DFF-related proteins, known as Drep1, Drep2, Drep3 and Drep4. Although the function of Drep1 and Drep4 is well known as DFF45 and DFF40 homologues, respectively, the function of Drep2 and Drep3 is still unclear. DFF-related proteins contain a conserved CIDE domain of ~90 amino acid residues that is involved in protein-protein interaction. Here, we showed that Drep1 directly bind to Drep2 as well as Drep4 via CIDE domain. In addition, we found that the interaction of Drep2 and Drep4 to Drep1 was not competitive indicating that Drep2 and Drep4 bind different place of Drep1. All together, we suggest that Drep1 might be involved in apoptotic DNA fragmentation of fly system by direct interaction with Drep2 as well as Drep4.

  8. Teriflunomide (Leflunomide Promotes Cytostatic, Antioxidant, and Apoptotic Effects in Transformed Prostate Epithelial Cells: Evidence Supporting a Role for Teriflunomide in Prostate Cancer Chemoprevention

    Directory of Open Access Journals (Sweden)

    Numsen Hail, Jr

    2010-06-01

    Full Text Available Teriflunomide (TFN is an inhibitor of de novo pyrimidine synthesis and the active metabolite of leflunomide. Leflunomide is prescribed to patients worldwide as an immunomodulatory and anti-inflammatory disease-modifying prodrug. Leflunomide inhibited the growth of human prostate cancer xenographs in mice, and leflunomide or TFN promoted cytostasis and/or apoptosis in cultured cells. These findings suggest that TFN could be useful in prostate cancer chemoprevention. We investigated the possible mechanistic aspects of this tenet by characterizing the effects of TFN using premalignant PWR-1E and malignant DU-145 human prostate epithelial cells. TFN promoted a dose- and time-dependent cytostasis or apoptosis induction in these cells. The cytostatic effects of TFN, which were reversible but not by the presence of excess uridine in the culture medium, included diminished cellular uridine levels, an inhibition in oxygen consumption, a suppression of reactive oxygen species (ROS generation, S-phase cell cycle arrest, and a conspicuous reduction in the size and number of the nucleoli in the nuclei of these cells. Conversely, TFN's apoptogenic effects were characteristic of catastrophic mitochondrial disruption (i.e., a dissipation of mitochondrial inner transmembrane potential, enhanced ROS production, mitochondrial cytochrome c release, and cytoplasmic vacuolization and followed by DNA fragmentation. The respiration-deficient derivatives of the DU-145 cells, which are also uridine auxotrophs, were markedly resistant to the cytostatic and apoptotic effects of TFN, implicating de novo pyrimidine synthesis and mitochondrial bioenergetics as the primary targets for TFN in the respiration competent cells. These mechanistic findings advocate a role for TFN and mitochondrial bioenergetics in prostate cancer chemoprevention.

  9. Chromium-induced membrane damage: protective role of ascorbic acid

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Importance of chromium as environmental toxicant is largely due to impact on the body to produce cellular toxicity. The impact of chromium and their supplementation with ascorbic acid was studied on plasma membrane of liver and kidney in male Wistar rats (80 - 100gbody weight). It has been observed that the intoxication with chromium ( i. p. ) at the dose of 0.8 mg/100g body weight per day for a period of 28 days causes significant increase in the level of cholesterol and decrease in the level of phospbolipid of both liver and kidney. The alkaline pbosphatase, total ATPase and Na + -K + -ATPase activities were significantly decreased in both liver and kidney after chromium treatment,except total ATPase activity of kidney. It is suggested that chromium exposure at the present dose and duration induce for the alterations of structure and function of both liver and kidney plasma membrane. Ascorbic acid ( i.p. at the dose of 0.5 mg,/100g body weight per day for period of 28 days) supplementation can reduce these structural changes in the plasma membrane of liver and kidney. But the functional changes can not be completely replenished by the ascorbic acid supplementation in response to chromium exposure. So it is also suggested that ascorbic acid (nutritional antioxidant) is useful free radical scavenger to restrain the chromium-induced membrane damage.

  10. Hepcidin Plays a Key Role in 6-OHDA Induced Iron Overload and Apoptotic Cell Death in a Cell Culture Model of Parkinson’s Disease

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    Qi Xu

    2016-01-01

    Full Text Available Background. Elevated brain iron levels have been implicated in the pathogenesis of Parkinson’s disease (PD. However, the precise mechanism underlying abnormal iron accumulation in PD is not clear. Hepcidin, a hormone primarily produced by hepatocytes, acts as a key regulator in both systemic and cellular iron homeostasis. Objective. We investigated the role of hepcidin in 6-hydroxydopamine (6-OHDA induced apoptosis in a cell culture model of PD. Methods. We downregulated hepcidin using siRNA interference in N27 dopaminergic neuronal cells and made a comparison with control siRNA transfected cells to investigate the role of hepcidin in 6-OHDA induced neurodegeneration. Results. Hepcidin knockdown (32.3%, P<0.0001 upregulated ferroportin 1 expression and significantly (P<0.05 decreased intracellular iron by 25%. Hepcidin knockdown also reduced 6-OHDA induced caspase-3 activity by 42% (P<0.05 and DNA fragmentation by 29% (P=0.086 and increased cell viability by 22% (P<0.05. In addition, hepcidin knockdown significantly attenuated 6-OHDA induced protein carbonyls by 52% (P<0.05 and intracellular iron by 28% (P<0.01, indicating the role of hepcidin in oxidative stress. Conclusions. Our results demonstrate that hepcidin knockdown protected N27 cells from 6-OHDA induced apoptosis and that hepcidin plays a major role in reducing cellular iron burden and oxidative damage by possibly regulating cellular iron export mediated by ferroportin 1.

  11. Role of Nicotinamide in DNA Damage, Mutagenesis, and DNA Repair

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    Devita Surjana

    2010-01-01

    Full Text Available Nicotinamide is a water-soluble amide form of niacin (nicotinic acid or vitamin B3. Both niacin and nicotinamide are widely available in plant and animal foods, and niacin can also be endogenously synthesized in the liver from dietary tryptophan. Nicotinamide is also commercially available in vitamin supplements and in a range of cosmetic, hair, and skin preparations. Nicotinamide is the primary precursor of nicotinamide adenine dinucleotide (NAD+, an essential coenzyme in ATP production and the sole substrate of the nuclear enzyme poly-ADP-ribose polymerase-1 (PARP-1. Numerous in vitro and in vivo studies have clearly shown that PARP-1 and NAD+ status influence cellular responses to genotoxicity which can lead to mutagenesis and cancer formation. This paper will examine the role of nicotinamide in the protection from carcinogenesis, DNA repair, and maintenance of genomic stability.

  12. Role of internal anal sphincter damage in the causation of idiopathic faecal incontinence: a prospective study.

    Science.gov (United States)

    Petros, Peter; Anderson, Jim

    2005-02-01

    This prospective study aimed to examine the relationship between internal anal sphincter (IAS) damage and 'idiopathic' faecal incontinence (FI) in 50 consecutive patients, using endoanal ultrasound examination. The external anal sphincter (EAS) was intact on direct and ultrasonic assessment in all patients. IAS damage was defined as complete rupture or attenuation, less than 2 mm thickness in some part of the sphincter. Complete rupture was found in one patient and damage in a further 17 (total 36%). All three nulliparous patients had normal IAS and EAS. IAS damage was only minimally associated with 'idiopathic' FI, suggesting IAS per se is unlikely to be a direct cause of FI in the 'idiopathic' group of FI patients. Its role might be analogous to the periurethral striated horse-shoe shape muscle in the urethra, which is thought to act as a mucosal sealant.

  13. Effect of administration of apoptotic blebs on disease development in lupus mice.

    NARCIS (Netherlands)

    Fransen, J.H.; Berden, J.H.M.; Koeter, C.M.; Adema, G.J.; Vlag, J. van der; Hilbrands, L.B.

    2012-01-01

    INTRODUCTION: Systemic lupus erythematosus (SLE) is an autoimmune disease characterised by the formation of autoantibodies against nuclear components. Disturbed apoptosis and reduced clearance of apoptotic material have been assigned a role in the pathogenesis of SLE. During apoptosis, apoptotic ble

  14. Is there a role for leukotrienes as mediators of ethanol-induced gastric mucosal damage

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, J.L.; Beck, P.L.; Morris, G.P. (Queen' s Univ., Kingston, Ontario (Canada))

    1988-01-01

    The role of leukotriene (LT) C{sub 4} as a mediator of ethanol-induced gastric mucosal damage was investigated. Rats were pretreated with a number of compounds, including inhibitors of leukotriene biosynthesis and agents that have previously been shown to reduce ethanol-induced damage prior to oral administration of absolute ethanol. Ethanol administration resulted in a fourfold increase in LTC{sub 4} synthesis. LTC{sub 4} synthesis could be reduced significantly by pretreatment with L651,392 or dexamethosone without altering the susceptibility of the gastric mucosa to ethanol-induced damage. Furthermore, changes in LBT{sub 4} synthesis paralleled the changes in LTC{sub 4} synthesis observed after ethanol administration. The effects of ethanol on gastric eicosanoid synthesis were further examined using an ex vivo gastric chamber preparation that allowed for application of ethanol to only one side of the stomach. These studies confirm that ethanol can stimulate gastric leukotriene synthesis independent of the production of hemorrhagic damage. Inhibition of LTC{sub 4} synthesis does not confer protection to the mucosa, suggesting that LTC{sub 4} does not play an important role in the etiology of ethanol-induced gastric damage.

  15. Stretch-activated channels in stretch-induced muscle damage: role in muscular dystrophy.

    Science.gov (United States)

    Yeung, Ella W; Allen, David G

    2004-08-01

    1. Stretch-induced muscle injury results in the damage that causes reduced force and increased membrane permeability. This muscle damage is caused, in part, by ionic entry through stretch-activated channels and blocking these channels with Gd3+ or streptomycin reduces the force deficit associated with damage. 2. Dystrophin-deficient muscles are more susceptible to stretch-induced muscle injury and the recovery from injury can be incomplete. We have found that Na+ entry associated with stretch-induced injury is enhanced in dystrophin-deficient muscles and that blockers of stretch-activated channels are capable of preventing ionic entry and reducing muscle damage. 3. A model is presented that proposes links between stretch-induced injury, opening of stretch-activated channels, increased levels of intracellular ions and various forms of muscle damage. Although changes in Na+ accompany stretch-induced muscle injury, we believe that changes in Ca2+ probably have a more central role in the damage process.

  16. H2AX Phosphorylation: Its Role in DNA Damage Response and Cancer Therapy

    Directory of Open Access Journals (Sweden)

    Monika Podhorecka

    2010-01-01

    Full Text Available Double-strand breaks (DSBs are the most deleterious DNA lesions, which, if left unrepaired, may have severe consequences for cell survival, as they lead to chromosome aberrations, genomic instability, or cell death. Various physical, chemical, and biological factors are involved in DSB induction. Cells respond to DNA damage by activating the so-called DNA damage response (DDR, a complex molecular mechanism developed to detect and repair DNA damage. The formation of DSBs triggers activation of many factors, including phosphorylation of the histone variant H2AX, producing γH2AX. Phosphorylation of H2AX plays a key role in DDR and is required for the assembly of DNA repair proteins at the sites containing damaged chromatin as well as for activation of checkpoints proteins which arrest the cell cycle progression. In general, analysis of γH2AX expression can be used to detect the genotoxic effect of different toxic substances. When applied to clinical samples from cancer patients, evaluation of γH2AX levels may allow not only to monitor the efficiency of anticancer treatment but also to predict of tumor cell sensitivity to DNA damaging anticancer agents and toxicity of anticancer treatment toward normal cells.

  17. A novel role of the chromokinesin Kif4A in DNA damage response.

    Science.gov (United States)

    Wu, Guikai; Zhou, Longen; Khidr, Lily; Guo, Xuning Emily; Kim, Wankee; Lee, Young Mi; Krasieva, Tatiana; Chen, Phang-Lang

    2008-07-01

    Chromokinesins are microtubule-motor molecules that possess chromatin binding activity and are important for mitotic and meiotic regulation. The chromokinesin-member Kif4A is unique in that it localizes to nucleus during interphase of the cell cycle. Kif4 deletion by gene targeting in mouse embryonic cells was known to associate with DNA damage response. However, its precise role in DNA damage or repair pathway is not clear. Here we report that Kif4A associates with BRCA2 in a biochemical identification and that the interaction is mediated by the Kif4A C-terminal cargo-binding domain and BRCA2 C-terminal conserved region. Upon nucleus-specific laser micro-irradiation, Kif4A was rapidly recruited to sites of DNA damage. Significantly, the depletion of Kif4A from cells by shRNA impaired the ionizing-radiation induced foci (IRIF) formation of Rad51, both quantitatively and qualitatively. In contrast, the IRIF of gamma-H2AX or NBS1 was largely intact. Moreover, Kif4A knockdown rendered cells hypersensitive to ionizing radiation in a colonogenic survival assay. We further demonstrated that Kif4A deficiency led to significantly decreased homologous recombination in an I-SceI endonuclease induced in vivo recombination assay. Together, our results suggest a novel role for a chromokinesin family member in the DNA damage response by modulating the BRCA2/Rad51 pathway.

  18. Caspase-9 mediates the apoptotic death of megakaryocytes and platelets, but is dispensable for their generation and function.

    Science.gov (United States)

    White, Michael J; Schoenwaelder, Simone M; Josefsson, Emma C; Jarman, Kate E; Henley, Katya J; James, Chloé; Debrincat, Marlyse A; Jackson, Shaun P; Huang, David C S; Kile, Benjamin T

    2012-05-03

    Apoptotic caspases, including caspase-9, are thought to facilitate platelet shedding by megakaryocytes. They are known to be activated during platelet apoptosis, and have also been implicated in platelet hemostatic responses. However, the precise requirement for, and the regulation of, apoptotic caspases have never been defined in either megakaryocytes or platelets. To establish the role of caspases in platelet production and function, we generated mice lacking caspase-9 in their hematopoietic system. We demonstrate that both megakaryocytes and platelets possess a functional apoptotic caspase cascade downstream of Bcl-2 family-mediated mitochondrial damage. Caspase-9 is the initiator caspase, and its loss blocks effector caspase activation. Surprisingly, steady-state thrombopoiesis is unperturbed in the absence of caspase-9, indicating that the apoptotic caspase cascade is not required for platelet production. In platelets, loss of caspase-9 confers resistance to the BH3 mimetic ABT-737, blocking phosphatidylserine (PS) exposure and delaying ABT-737-induced thrombocytopenia in vivo. Despite this, steady-state platelet lifespan is normal. Casp9(-/-) platelets are fully capable of physiologic hemostatic responses and functional regulation of adhesive integrins in response to agonist. These studies demonstrate that the apoptotic caspase cascade is required for the efficient death of megakaryocytes and platelets, but is dispensable for their generation and function.

  19. Apoptotic death sensor: an organelle's alter ego?

    Science.gov (United States)

    Bratton, S B; Cohen, G M

    2001-06-01

    Caspases are intracellular cysteine proteases that are primarily responsible for the stereotypic morphological and biochemical changes that are associated with apoptosis. Caspases are often activated by the apoptotic protease-activating factor 1 (APAF-1) apoptosome, a complex that is formed following mitochondrial release of cytochrome c in response to many death-inducing stimuli. Both pro- and anti-apoptotic BCL-2 family members regulate apoptosis, primarily by their effects on mitochondria, whereas many inhibitor of apoptosis proteins (IAPs) regulate apoptosis by directly inhibiting distinct caspases. Exposure of cells to chemicals and radiation, as well as loss of trophic stimuli, perturb cellular homeostasis and, depending on the type of cellular stress, particular or multiple organelles appear to 'sense' the damage and signal the cell to undergo apoptosis by stimulating the formation of unique and/or common caspase-activating complexes.

  20. Interconnections between apoptotic, autophagic and necrotic pathways: implications for cancer therapy development.

    Science.gov (United States)

    Jain, Mayur V; Paczulla, Anna M; Klonisch, Thomas; Dimgba, Florence N; Rao, Sahana B; Roberg, Karin; Schweizer, Frank; Lengerke, Claudia; Davoodpour, Padideh; Palicharla, Vivek R; Maddika, Subbareddy; Łos, Marek

    2013-01-01

    The rapid accumulation of knowledge on apoptosis regulation in the 1990s was followed by the development of several experimental anticancer- and anti-ischaemia (stroke or myocardial infarction) drugs. Activation of apoptotic pathways or the removal of cellular apoptotic inhibitors has been suggested to aid cancer therapy and the inhibition of apoptosis was thought to limit ischaemia-induced damage. However, initial clinical studies on apoptosis-modulating drugs led to unexpected results in different clinical conditions and this may have been due to co-effects on non-apoptotic interconnected cell death mechanisms and the 'yin-yang' role of autophagy in survival versus cell death. In this review, we extend the analysis of cell death beyond apoptosis. Upon introduction of molecular pathways governing autophagy and necrosis (also called necroptosis or programmed necrosis), we focus on the interconnected character of cell death signals and on the shared cell death processes involving mitochondria (e.g. mitophagy and mitoptosis) and molecular signals playing prominent roles in multiple pathways (e.g. Bcl2-family members and p53). We also briefly highlight stress-induced cell senescence that plays a role not only in organismal ageing but also offers the development of novel anticancer strategies. Finally, we briefly illustrate the interconnected character of cell death forms in clinical settings while discussing irradiation-induced mitotic catastrophe. The signalling pathways are discussed in their relation to cancer biology and treatment approaches.

  1. Macrophage recognition of ICAM-3 on apoptotic leukocytes.

    Science.gov (United States)

    Moffatt, O D; Devitt, A; Bell, E D; Simmons, D L; Gregory, C D

    1999-06-01

    Cells undergoing apoptosis are cleared rapidly by phagocytes, thus preventing tissue damage caused by loss of plasma membrane integrity. In this study, we show that the surface of leukocytes is altered during apoptosis such that the first Ig-like domain of ICAM-3 (CD50) can participate in the recognition and phagocytosis of the apoptotic cells by macrophages. Macrophage recognition of apoptotic cell-associated ICAM-3 was demonstrated both on leukocytes and, following transfection of exogenous ICAM-3, on nonleukocytes. The change in ICAM-3 was a consistent consequence of apoptosis triggered by various stimuli, suggesting that it occurs as part of a final common pathway of apoptosis. Alteration of ICAM-3 on apoptotic cells permitting recognition by macrophages resulted in a switch in ICAM-3-binding preference from the prototypic ICAM-3 counterreceptor, LFA-1, to an alternative macrophage receptor. Using mAbs to block macrophage/apoptotic cell interactions, we were unable to obtain evidence that either the alternative ICAM-3 counterreceptor alpha d beta 2 or the apoptotic cell receptor alpha v beta 3 was involved in the recognition of ICAM-3. By contrast, mAb blockade of macrophage CD14 inhibited ICAM-3-dependent recognition of apoptotic cells. These results show that ICAM-3 can function as a phagocytic marker of apoptotic leukocytes on which it acquires altered macrophage receptor-binding activity.

  2. A novel, non-apoptotic role for Scythe/BAT3: a functional switch between the pro- and anti-proliferative roles of p21 during the cell cycle.

    Directory of Open Access Journals (Sweden)

    Sheila T Yong

    Full Text Available BACKGROUND: Scythe/BAT3 is a member of the BAG protein family whose role in apoptosis has been extensively studied. However, since the developmental defects observed in Bat3-null mouse embryos cannot be explained solely by defects in apoptosis, we investigated whether BAT3 is also involved in cell-cycle progression. METHODS/PRINCIPAL FINDINGS: Using a stable-inducible Bat3-knockdown cellular system, we demonstrated that reduced BAT3 protein level causes a delay in both G1/S transition and G2/M progression. Concurrent with these changes in cell-cycle progression, we observed a reduction in the turnover and phosphorylation of the CDK inhibitor p21, which is best known as an inhibitor of DNA replication; however, phosphorylated p21 has also been shown to promote G2/M progression. Our findings indicate that in Bat3-knockdown cells, p21 continues to be synthesized during cell-cycle phases that do not normally require p21, resulting in p21 protein accumulation and a subsequent delay in cell-cycle progression. Finally, we showed that BAT3 co-localizes with p21 during the cell cycle and is required for the translocation of p21 from the cytoplasm to the nucleus during the G1/S transition and G2/M progression. CONCLUSION: Our study reveals a novel, non-apoptotic role for BAT3 in cell-cycle regulation. By maintaining a low p21 protein level during the G1/S transition, BAT3 counteracts the inhibitory effect of p21 on DNA replication and thus enables the cells to progress from G1 to S phase. Conversely, during G2/M progression, BAT3 facilitates p21 phosphorylation by cyclin A/Cdk2, an event required for G2/M progression. BAT3 modulates these pro- and anti-proliferative roles of p21 at least in part by regulating cyclin A abundance, as well as p21 translocation between the cytoplasm and the nucleus to ensure that it functions in the appropriate intracellular compartment during each phase of the cell cycle.

  3. Protective Role of Nuclear Factor E2-Related Factor 2 against Acute Oxidative Stress-Induced Pancreatic β-Cell Damage

    Directory of Open Access Journals (Sweden)

    Jingqi Fu

    2015-01-01

    Full Text Available Oxidative stress is implicated in the pathogenesis of pancreatic β-cell dysfunction that occurs in both type 1 and type 2 diabetes. Nuclear factor E2-related factor 2 (NRF2 is a master regulator in the cellular adaptive response to oxidative stress. The present study found that MIN6 β-cells with stable knockdown of Nrf2 (Nrf2-KD and islets isolated from Nrf2-knockout mice expressed substantially reduced levels of antioxidant enzymes in response to a variety of stressors. In scramble MIN6 cells or wild-type islets, acute exposure to oxidative stressors, including hydrogen peroxide (H2O2 and S-nitroso-N-acetylpenicillamine, resulted in cell damage as determined by decrease in cell viability, reduced ATP content, morphology changes of islets, and/or alterations of apoptotic biomarkers in a concentration- and/or time-dependent manner. In contrast, silencing of Nrf2 sensitized MIN6 cells or islets to the damage. In addition, pretreatment of MIN6 β-cells with NRF2 activators, including CDDO-Im, dimethyl fumarate (DMF, and tert-butylhydroquinone (tBHQ, protected the cells from high levels of H2O2-induced cell damage. Given that reactive oxygen species (ROS are involved in regulating glucose-stimulated insulin secretion (GSIS and persistent activation of NRF2 blunts glucose-triggered ROS signaling and GSIS, the present study highlights the distinct roles that NRF2 may play in pancreatic β-cell dysfunction that occurs in different stages of diabetes.

  4. Does exercise-induced muscle damage play a role in skeletal muscle hypertrophy?

    Science.gov (United States)

    Schoenfeld, Brad J

    2012-05-01

    Exercise-induced muscle damage (EIMD) occurs primarily from the performance of unaccustomed exercise, and its severity is modulated by the type, intensity, and duration of training. Although concentric and isometric actions contribute to EIMD, the greatest damage to muscle tissue is seen with eccentric exercise, where muscles are forcibly lengthened. Damage can be specific to just a few macromolecules of tissue or result in large tears in the sarcolemma, basal lamina, and supportive connective tissue, and inducing injury to contractile elements and the cytoskeleton. Although EIMD can have detrimental short-term effects on markers of performance and pain, it has been hypothesized that the associated skeletal muscle inflammation and increased protein turnover are necessary for long-term hypertrophic adaptations. A theoretical basis for this belief has been proposed, whereby the structural changes associated with EIMD influence gene expression, resulting in a strengthening of the tissue and thus protection of the muscle against further injury. Other researchers, however, have questioned this hypothesis, noting that hypertrophy can occur in the relative absence of muscle damage. Therefore, the purpose of this article will be twofold: (a) to extensively review the literature and attempt to determine what, if any, role EIMD plays in promoting skeletal muscle hypertrophy and (b) to make applicable recommendations for resistance training program design.

  5. Apoptosis and DNA damage in human spermatozoa

    Institute of Scientific and Technical Information of China (English)

    R John Aitken; Adam J Koppers

    2011-01-01

    DNA damage is frequently encountered in spermatozoa of subfertile males and is correlated with a range of adverse clinical outcomes including impaired fertilization, disrupted preimplantation embryonic development, increased rates of miscarriage and an enhanced risk of disease in the progeny. The etiology of DNA fragmentation in human spermatozoa is closely correlated with the appearance of oxidative base adducts and evidence of impaired spermiogenesis. We hypothesize that oxidative stress impedes spermiogenesis,resulting in the generation of spermatozoa with poorly remodelled chromatin. These defective cells have a tendency to default to an apoptotic pathway associated with motility loss, caspase activation, phosphatidylserine exteriorization and the activation of free radical generation by the mitochondria. The latter induces lipid peroxidation and oxidative DNA damage, which then leads to DNA fragmentation and cell death. The physical architecture of spermatozoa prevents any nucleases activated as a result of this apoptotic process from gaining access to the nuclear DNA and inducing its fragmentation. It is for this reason that a majority of the DNA damage encountered in human spermatozoa seems to be oxidative. Given the important role that oxidative stress seems to have in the etiology of DNA damage, there should be an important role for antioxidants in the treatment of this condition. If oxidative DNA damage in spermatozoa is providing a sensitive readout of systemic oxidative stress, the implications of these findings could stretch beyond our immediate goal of trying to minimize DNA damage in spermatozoa as a prelude to assisted conception therapy.

  6. Membrane phospholipids, lipoxidative damage and molecular integrity: a causal role in aging and longevity.

    Science.gov (United States)

    Pamplona, Reinald

    2008-10-01

    Nonenzymatic molecular modifications induced by reactive carbonyl species (RCS) generated by peroxidation of membrane phospholipids acyl chains play a causal role in the aging process. Most of the biological effects of RCS, mainly alpha,beta-unsaturated aldehydes, di-aldehydes, and keto-aldehydes, are due to their capacity to react with cellular constituents, forming advanced lipoxidation end-products (ALEs). Compared to reactive oxygen and nitrogen species, lipid-derived RCS are stable and can diffuse within or even escape from the cell and attack targets far from the site of formation. Therefore, these soluble reactive intermediates, precursors of ALEs, are not only cytotoxic per se, but they also behave as mediators and propagators of oxidative stress and cellular and tissue damage. The consequent loss-of-function and structural integrity of modified biomolecules can have a wide range of downstream functional consequences and may be the cause of subsequent cellular dysfunctions and tissue damage. The causal role of ALEs in aging and longevity is inferred from the findings that follow: a) its accumulation with aging in several tissues and species; b) physiological interventions (dietary restriction) that increase longevity, decrease ALEs content; c) the longer the longevity of a species, the lower is the lipoxidation-derived molecular damage; and finally d) exacerbated levels of ALEs are associated with pathological states.

  7. A pathogenic role of complement in arterial hypertension and hypertensive end organ damage.

    Science.gov (United States)

    Wenzel, Ulrich O; Bode, Marlies; Köhl, Jörg; Ehmke, Heimo

    2017-03-01

    The self-amplifying cascade of messenger and effector molecules of the complement system serves as a powerful danger-sensing system that protects the host from a hostile microbial environment, while maintaining proper tissue and organ function through effective clearance of altered or dying cells. As an important effector arm of innate immunity, it also plays important roles in the regulation of adaptive immunity. Innate and adaptive immune responses have been identified as crucial players in the pathogenesis of arterial hypertension and hypertensive end organ damage. In line with this view, complement activation may drive the pathology of hypertension and hypertensive injury through its impact on innate and adaptive immune responses. It is well known that complement activation can cause tissue inflammation and injury and complement-inhibitory drugs are effective treatments for several inflammatory diseases. In addition to these proinflammatory properties, complement cleavage fragments of C3 and C5 can exert anti-inflammatory effects that dampen the inflammatory response to injury. Recent experimental data strongly support a role for complement in arterial hypertension. The remarkably similar clinical and histopathological features of malignant nephrosclerosis and atypical hemolytic uremic syndrome, which is driven by complement activation, suggest a role for complement also in the development of malignant nephrosclerosis. Herein, we will review canonical and noncanonical pathways of complement activation as the framework to understand the multiple roles of complement in arterial hypertension and hypertensive end organ damage.

  8. Vascular endothelial growth factor enhances macrophage clearance of apoptotic cells

    Science.gov (United States)

    Dalal, Samay; Horstmann, Sarah A.; Richens, Tiffany R.; Tanaka, Takeshi; Doe, Jenna M.; Boe, Darren M.; Voelkel, Norbert F.; Taraseviciene-Stewart, Laimute; Janssen, William J.; Lee, Chun G.; Elias, Jack A.; Bratton, Donna; Tuder, Rubin M.; Henson, Peter M.; Vandivier, R. William

    2012-01-01

    Efficient clearance of apoptotic cells from the lung by alveolar macrophages is important for the maintenance of tissue structure and function. Lung tissue from humans with emphysema contains increased numbers of apoptotic cells and decreased levels of vascular endothelial growth factor (VEGF). Mice treated with VEGF receptor inhibitors have increased numbers of apoptotic cells and develop emphysema. We hypothesized that VEGF regulates apoptotic cell clearance by alveolar macrophages (AM) via its interaction with VEGF receptor 1 (VEGF R1). Our data show that the uptake of apoptotic cells by murine AMs and human monocyte-derived macrophages is inhibited by depletion of VEGF and that VEGF activates Rac1. Antibody blockade or pharmacological inhibition of VEGF R1 activity also decreased apoptotic cell uptake ex vivo. Conversely, overexpression of VEGF significantly enhanced apoptotic cell uptake by AMs in vivo. These results indicate that VEGF serves a positive regulatory role via its interaction with VEGF R1 to activate Rac1 and enhance AM apoptotic cell clearance. PMID:22307908

  9. New insights into the apoptotic process in mollusks: characterization of caspase genes in Mytilus galloprovincialis.

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    Alejandro Romero

    Full Text Available Apoptosis is an essential biological process in the development and maintenance of immune system homeostasis. Caspase proteins constitute the core of the apoptotic machinery and can be categorized as either initiators or effectors of apoptosis. Although the genes encoding caspase proteins have been described in vertebrates and in almost all invertebrate phyla, there are few reports describing the initiator and executioner caspases or the modulation of their expression by different stimuli in different apoptotic pathways in bivalves. In the present work, we characterized two initiator and four executioner caspases in the mussel Mytilus galloprovincialis. Both initiators and executioners showed structural features that make them different from other caspase proteins already described. Evaluation of the genes' tissue expression patterns revealed extremely high expression levels within the gland and gills, where the apoptotic process is highly active due to the clearance of damaged cells. Hemocytes also showed high expression values, probably due to of the role of apoptosis in the defense against pathogens. To understand the mechanisms of caspase gene regulation, hemocytes were treated with UV-light, environmental pollutants and pathogen-associated molecular patterns (PAMPs and apoptosis was evaluated by microscopy, flow cytometry and qPCR techniques. Our results suggest that the apoptotic process could be tightly regulated in bivalve mollusks by overexpression/suppression of caspase genes; additionally, there is evidence of caspase-specific responses to pathogens and pollutants. The apoptotic process in mollusks has a similar complexity to that of vertebrates, but presents unique features that may be related to recurrent exposure to environmental changes, pollutants and pathogens imposed by their sedentary nature.

  10. Relationship between apoptotic markers in semen from fertile men and demographic, hormonal and seminal characteristics

    Institute of Scientific and Technical Information of China (English)

    Ina O Specht; Marcello Spanò; Karin S Hougaard; Gian C Manicardi; Davide Bizzaro; Gunnar Toft; Aleksander Giwercman; Jens-Peter E Bonde

    2012-01-01

    Apoptosis in the testis has two putative roles during normal spermatogenesis; limitation of the germ ceil population to numbers that can be supported by the Sertoli cells,and,possibly,selective depletion of meiotic and postmeiotic abnormal germ cells.We investigated the demographic and biological correlates of the pro-apoptotic marker Fas and the anti-apoptotic marker Bcl-xL in sperm cells of fertile men.Six hundred and four men from Greenland,Poland and Ukraine were consecutively enrolled during their pregnant wife's antenatal visits.Semen analysis was performed as recommended by the World Health Organization.Immunofluorescence coupled to flow cytometry was utilized for detection of apoptotic markers in the sperm cell.DNA damage was assessed by flow cytometry using both the sperm chromatin structure assay (SCSA) and the terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay.The percentage of Fas-positive sperm cells was higher in men with high total sperm count (P<O.01),more motile sperms (P=O.04) and fewer sperm head defects (P=O.05).These associations were consistent within and across study regions.Furthermore,testosterone,follicle-stimulating hormone (FSH) and sexual hormone-binding globulin (SHBG) were significantly negatively correlated with Fas within and across regions as well.The data indicated no association between the anti-apoptotic Bcl-xL marker and semen or personal characteristics.The finding of Fas-positive sperm cells associated with better semen quality in a cohort of spouses of pregnant women seems different from previous data obtained in infertile men and warrants further investigation to clarifv the biological significance of sperm apoptotic markers.

  11. The Yin-Yang of DNA Damage Response: Roles in Tumorigenesis and Cellular Senescence

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    Sang Soo Kim

    2013-01-01

    Full Text Available Senescent cells are relatively stable, lacking proliferation capacity yet retaining metabolic activity. In contrast, cancer cells are rather invasive and devastating, with uncontrolled proliferative capacity and resistance to cell death signals. Although tumorigenesis and cellular senescence are seemingly opposite pathological events, they are actually driven by a unified mechanism: DNA damage. Integrity of the DNA damage response (DDR network can impose a tumorigenesis barrier by navigating abnormal cells to cellular senescence. Compromise of DDR, possibly due to the inactivation of DDR components, may prevent cellular senescence but at the expense of tumor formation. Here we provide an overview of the fundamental role of DDR in tumorigenesis and cellular senescence, under the light of the Yin-Yang concept of Chinese philosophy. Emphasis is placed on discussing DDR outcome in the light of in vivo models. This information is critical as it can help make better decisions for clinical treatments of cancer patients.

  12. Senataxin plays an essential role with DNA damage response proteins in meiotic recombination and gene silencing.

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    Olivier J Becherel

    2013-04-01

    Full Text Available Senataxin, mutated in the human genetic disorder ataxia with oculomotor apraxia type 2 (AOA2, plays an important role in maintaining genome integrity by coordination of transcription, DNA replication, and the DNA damage response. We demonstrate that senataxin is essential for spermatogenesis and that it functions at two stages in meiosis during crossing-over in homologous recombination and in meiotic sex chromosome inactivation (MSCI. Disruption of the Setx gene caused persistence of DNA double-strand breaks, a defect in disassembly of Rad51 filaments, accumulation of DNA:RNA hybrids (R-loops, and ultimately a failure of crossing-over. Senataxin localised to the XY body in a Brca1-dependent manner, and in its absence there was incomplete localisation of DNA damage response proteins to the XY chromosomes and ATR was retained on the axial elements of these chromosomes, failing to diffuse out into chromatin. Furthermore persistence of RNA polymerase II activity, altered ubH2A distribution, and abnormal XY-linked gene expression in Setx⁻/⁻ revealed an essential role for senataxin in MSCI. These data support key roles for senataxin in coordinating meiotic crossing-over with transcription and in gene silencing to protect the integrity of the genome.

  13. Senataxin plays an essential role with DNA damage response proteins in meiotic recombination and gene silencing.

    Science.gov (United States)

    Becherel, Olivier J; Yeo, Abrey J; Stellati, Alissa; Heng, Evelyn Y H; Luff, John; Suraweera, Amila M; Woods, Rick; Fleming, Jean; Carrie, Dianne; McKinney, Kristine; Xu, Xiaoling; Deng, Chuxia; Lavin, Martin F

    2013-04-01

    Senataxin, mutated in the human genetic disorder ataxia with oculomotor apraxia type 2 (AOA2), plays an important role in maintaining genome integrity by coordination of transcription, DNA replication, and the DNA damage response. We demonstrate that senataxin is essential for spermatogenesis and that it functions at two stages in meiosis during crossing-over in homologous recombination and in meiotic sex chromosome inactivation (MSCI). Disruption of the Setx gene caused persistence of DNA double-strand breaks, a defect in disassembly of Rad51 filaments, accumulation of DNA:RNA hybrids (R-loops), and ultimately a failure of crossing-over. Senataxin localised to the XY body in a Brca1-dependent manner, and in its absence there was incomplete localisation of DNA damage response proteins to the XY chromosomes and ATR was retained on the axial elements of these chromosomes, failing to diffuse out into chromatin. Furthermore persistence of RNA polymerase II activity, altered ubH2A distribution, and abnormal XY-linked gene expression in Setx⁻/⁻ revealed an essential role for senataxin in MSCI. These data support key roles for senataxin in coordinating meiotic crossing-over with transcription and in gene silencing to protect the integrity of the genome.

  14. Ca2+在鼻咽癌细胞凋亡性容积减小中的作用%Roles of Ca2+ in Apoptotic Volume Decrease in Nasopharyngeal Carcinoma Cells

    Institute of Scientific and Technical Information of China (English)

    向静瑶; 胡代军; 孙利华; 杨林杰; 左婉红; 朱林燕; 陈丽新; 王立伟

    2011-01-01

    Objective To study the role of calcium signaling pathway in apoptotic volume decrease (AVD) in nasopharyngeal carcinoma cells. Methods The apoptotic inducer Cisplatin was used to induce apoptotic volume decrease in poorly differentiated nasopharyngeal carcinoma cells (CNE-2Z cells). The software Q500MC was employed for acquisition of time-lapse images of living cells. Cell volume changes were obtained by analysis of the image analysis software Scion Image. Results Extracellular application of Cisplatin induced a decrease of cell volume. The Cisplatin-induced changes in cell volume were significant 10 min after exposed to bath solution containing Cisplatin. Depletion of calcium from the bath solution or extracellular applications of calcium channel blocker nifedipine delayed the initiation of AVD induced by Cisplatin, but not the appearance of AVD. There was no significant difference in AVD 50 min after applications of Cisplatin between control and cells treated with nifedipine or Ca2+ -free bath solution. Conclusion The inflow of Ca2+ across the cell membrane may play an important role in activation of AVD at the early stage of apoptosis.%目的 探讨钙信号途径在凋亡性细胞容积减小中的作用.方法 用凋亡诱导剂顺铂诱导低分化鼻咽癌CNE-2Z细胞发生凋亡性细胞容积减小(AVD),采用Q500MC软件控制定时拍摄固定视野活细胞图像,Scion Image图像分析软件检测细胞容积变化.结果 细胞外灌流顺铂后细胞体积减小,10min后细胞体积减小差异有统计学意义.去除灌流液中的Ca2+或用钙通道阻断剂Nifedipine阻断钙通道后,延缓顺铂诱导的细胞容积减小的发生,但不能防止细胞缩小过程的出现,50 min后,Nifedipine组和无Ca2+灌流液组与顺铂对照组AVD水平均无差异.结论 细胞外Ca2+内流可能在触发细胞凋亡早期细胞容积减小中起重要作用.

  15. Role of Material Processing on the Dynamic Strength & Damage Behavior of S200F Beryllium

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    Adams, Chris; Anderson, William; Blumenthal, William; Gray, George

    2011-06-01

    We have performed a number of plate impact experiments on both vacuum hot-pressed (VHP) and roll-textured S200F Be to gain insight into the role of initial material processing on the strength and damage behavior of this technologically important material. These experiments extend and supplement results reported earlier. Variations in Hugoniot elastic limit (HEL), HEL decay with shock run distance, spall strength, and deformation response observed in VISAR traces will be discussed with respect to the relative roles of twinning and dislocation mediated slip in the overall material mechanical response. We will also discuss the influence of strain rate on spall behavior and compare our plate impact results with those of explosively driven (Taylor-wave) loading experiments presented by L. H. Hull in Session Y2-6 of the 2009 APS-SCCM Conference. C. D. Adams, et. al., ``Shock Compression of Condensed Matter - 2009, AIP Conference Proceedings 1195, 1, 509-512, (2009).

  16. Critical role of NADPH oxidase in neuronal oxidative damage and microglia activation following traumatic brain injury.

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    Quan-Guang Zhang

    Full Text Available BACKGROUND: Oxidative stress is known to play an important role in the pathology of traumatic brain injury. Mitochondria are thought to be the major source of the damaging reactive oxygen species (ROS following TBI. However, recent work has revealed that the membrane, via the enzyme NADPH oxidase can also generate the superoxide radical (O(2(-, and thereby potentially contribute to the oxidative stress following TBI. The current study thus addressed the potential role of NADPH oxidase in TBI. METHODOLOGY/PRINCIPAL FINDINGS: The results revealed that NADPH oxidase activity in the cerebral cortex and hippocampal CA1 region increases rapidly following controlled cortical impact in male mice, with an early peak at 1 h, followed by a secondary peak from 24-96 h after TBI. In situ localization using oxidized hydroethidine and the neuronal marker, NeuN, revealed that the O(2(- induction occurred in neurons at 1 h after TBI. Pre- or post-treatment with the NADPH oxidase inhibitor, apocynin markedly inhibited microglial activation and oxidative stress damage. Apocynin also attenuated TBI-induction of the Alzheimer's disease proteins β-amyloid and amyloid precursor protein. Finally, both pre- and post-treatment of apocynin was also shown to induce significant neuroprotection against TBI. In addition, a NOX2-specific inhibitor, gp91ds-tat was also shown to exert neuroprotection against TBI. CONCLUSIONS/SIGNIFICANCE: As a whole, the study demonstrates that NADPH oxidase activity and superoxide production exhibit a biphasic elevation in the hippocampus and cortex following TBI, which contributes significantly to the pathology of TBI via mediation of oxidative stress damage, microglial activation, and AD protein induction in the brain following TBI.

  17. Neuroprotective role of hydralazine in rat spinal cord injury-attenuation of acrolein-mediated damage.

    Science.gov (United States)

    Park, Jonghyuck; Zheng, Lingxing; Marquis, Andrew; Walls, Michael; Duerstock, Brad; Pond, Amber; Vega-Alvarez, Sasha; Wang, He; Ouyang, Zheng; Shi, Riyi

    2014-04-01

    Acrolein, an α,β-unsaturated aldehyde and a reactive product of lipid peroxidation, has been suggested as a key factor in neural post-traumatic secondary injury in spinal cord injury (SCI), mainly based on in vitro and ex vivo evidence. Here, we demonstrate an increase of acrolein up to 300%; the elevation lasted at least 2 weeks in a rat SCI model. More importantly, hydralazine, a known acrolein scavenger can provide neuroprotection when applied systemically. Besides effectively reducing acrolein, hydralazine treatment also resulted in significant amelioration of tissue damage, motor deficits, and neuropathic pain. This effect was further supported by demonstrating the ability of hydralazine to reach spinal cord tissue at a therapeutic level following intraperitoneal application. This suggests that hydralazine is an effective neuroprotective agent not only in vitro, but in a live animal model of SCI as well. Finally, the role of acrolein in SCI was further validated by the fact that acrolein injection into the spinal cord caused significant SCI-like tissue damage and motor deficits. Taken together, available evidence strongly suggests a critical causal role of acrolein in the pathogenesis of spinal cord trauma. Since acrolein has been linked to a variety of illness and conditions, we believe that acrolein-scavenging measures have the potential to be expanded significantly ensuring a broad impact on human health.

  18. Role of gap junction and connexin-43 in hypoxic-ischemic brain damage

    Institute of Scientific and Technical Information of China (English)

    Jieying Lin; Niyang Lin

    2006-01-01

    OBJECTEVE:Gap junctin (GJ)is the structural basis for direct intercellular communication of nerve cells . Connexin(Cx) is the protein subunit for constructling GJ channel. Among them, Cx43is closely related with nervous system. Both Cx43 and nervous system play an important role in the pathophysiological development of hypoxic-ischemic injury. We are in attempt to investigate GJ,Cx43 and their correlations with hypoxic-ischemic brain damage by research.DATA SOURCES:Using the terms "brain gap junction"in English and "gap junction"in Chinese, we searched the Medline database and Chinese BioMedical Literature Database as well as China Hospital Knowledge Database to identify the articles published from 1996 to 2006 about GJ and brain hypoxic-ischemic injury.STUDY SELECTION:The articles were selected firstly and abstracts of 250 articles were read thuugh.Articles in which the experimental design met randomized controlled principle were included,and study articles and case reports with repetitve contents were excluded.DATA EXTRACTION:Among 53 included correlative articles, 23 were excluded for repetitive contents and the other 30 were analyzed.DATA SYNTHESIS:GJ,widely esistling in nervous system,plays a key role in maintainling normal differentiation and development as well as physiological function brain tissue.GJ channel is a hydrophilic,low-selectivity and lowohmic channel, which can provide direct channel for intercellular substance transmission and information communication. It plays an important role in the differentiation and development of nerve cells and regulation of physiological function,The funtions of GJ channel are regulated by many factors,which invilved intracellular Ph value, Ca2+concentration, ATP concentration, phosphorylation of Cx, transchannel pressure,some neurohormonal factors,regulatory factors of protein and so on. Cx43 is the main component of GJ channel in the brain tissues. Its expression in the brain tissue of mammal is the strongest

  19. Catalytic and non-catalytic roles for the mono-ADP-ribosyltransferase Arr in the mycobacterial DNA damage response.

    Science.gov (United States)

    Stallings, Christina L; Chu, Linda; Li, Lucy X; Glickman, Michael S

    2011-01-01

    Recent evidence indicates that the mycobacterial response to DNA double strand breaks (DSBs) differs substantially from previously characterized bacteria. These differences include the use of three DSB repair pathways (HR, NHEJ, SSA), and the CarD pathway, which integrates DNA damage with transcription. Here we identify a role for the mono-ADP-ribosyltransferase Arr in the mycobacterial DNA damage response. Arr is transcriptionally induced following DNA damage and cellular stress. Although Arr is not required for induction of a core set of DNA repair genes, Arr is necessary for suppression of a set of ribosomal protein genes and rRNA during DNA damage, placing Arr in a similar pathway as CarD. Surprisingly, the catalytic activity of Arr is not required for this function, as catalytically inactive Arr was still able to suppress ribosomal protein and rRNA expression during DNA damage. In contrast, Arr substrate binding and catalytic activities were required for regulation of a small subset of other DNA damage responsive genes, indicating that Arr has both catalytic and noncatalytic roles in the DNA damage response. Our findings establish an endogenous cellular function for a mono-ADP-ribosyltransferase apart from its role in mediating Rifampin resistance.

  20. Catalytic and non-catalytic roles for the mono-ADP-ribosyltransferase Arr in the mycobacterial DNA damage response.

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    Christina L Stallings

    Full Text Available Recent evidence indicates that the mycobacterial response to DNA double strand breaks (DSBs differs substantially from previously characterized bacteria. These differences include the use of three DSB repair pathways (HR, NHEJ, SSA, and the CarD pathway, which integrates DNA damage with transcription. Here we identify a role for the mono-ADP-ribosyltransferase Arr in the mycobacterial DNA damage response. Arr is transcriptionally induced following DNA damage and cellular stress. Although Arr is not required for induction of a core set of DNA repair genes, Arr is necessary for suppression of a set of ribosomal protein genes and rRNA during DNA damage, placing Arr in a similar pathway as CarD. Surprisingly, the catalytic activity of Arr is not required for this function, as catalytically inactive Arr was still able to suppress ribosomal protein and rRNA expression during DNA damage. In contrast, Arr substrate binding and catalytic activities were required for regulation of a small subset of other DNA damage responsive genes, indicating that Arr has both catalytic and noncatalytic roles in the DNA damage response. Our findings establish an endogenous cellular function for a mono-ADP-ribosyltransferase apart from its role in mediating Rifampin resistance.

  1. Resveratrol ameliorates renal damage, increases expression of heme oxygenase-1, and has anti-complement, anti-oxidative, and anti-apoptotic effects in a murine model of membranous nephropathy.

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    Chia-Chao Wu

    Full Text Available Idiopathic membranous nephropathy (MN is an autoimmune-mediated glomerulonephritis and a common cause of nephrotic syndrome in adults. There are limited available treatments for MN. We assessed the efficacy of resveratrol (RSV therapy for treatment of MN in a murine model of this disease.Murine MN was experimentally induced by daily subcutaneous administration of cationic bovine serum albumin, with phosphate-buffered saline used in control mice. MN mice were untreated or given RSV. Disease severity and pathogenesis was assessed by determination of metabolic and histopathology profiles, lymphocyte subsets, immunoglobulin production, oxidative stress, apoptosis, and production of heme oxygenase-1 (HO1.MN mice given RSV had significantly reduced proteinuria and a marked amelioration of glomerular lesions. RSV also significantly attenuated immunofluorescent staining of C3, although there were no changes of serum immunoglobulin levels or immunocomplex deposition in the kidneys. RSV treatment of MN mice also reduced the production of reactive oxygen species (ROS, reduced cell apoptosis, and upregulated heme oxygenase 1 (HO1. Inhibition of HO1 with tin protoporphyrin IX partially reversed the renoprotective effects of RSV. The HO1 induced by RSV maybe via Nrf2 signaling.Our results show that RSV increased the expression of HO1 and ameliorated the effects of membranous nephropathy in a mouse model due to its anti-complement, anti-oxidative, and anti-apoptotic effects. RSV appears to have potential as a treatment for MN.

  2. Role of IL-1alpha and IL-1beta in ischemic brain damage.

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    Boutin, H; LeFeuvre, R A; Horai, R; Asano, M; Iwakura, Y; Rothwell, N J

    2001-08-01

    The cytokine interleukin-1 (IL-1) has been strongly implicated in the pathogenesis of ischemic brain damage. Evidence to date suggests that the major form of IL-1 contributing to ischemic injury is IL-1beta rather than IL-1alpha, but this has not been tested directly. The objective of the present study was to compare the effects of transient cerebral ischemia [30 min middle cerebral artery occlusion (MCAO)] on neuronal injury in wild-type (WT) mice and in IL-1alpha, IL-1beta, or both IL-1alpha and IL-1beta knock-out (KO) mice. Mice lacking both forms of IL-1 exhibited dramatically reduced ischemic infarct volumes compared with wild type (total volume, 70%; cortex, 87% reduction). Ischemic damage compared with WT mice was not significantly altered in mice lacking either IL-1alpha or IL-1beta alone. IL-1beta mRNA, but not IL-1alpha or the IL-1 type 1 receptor, was strongly induced by MCAO in WT and IL-1alpha KO mice. Administration (intracerebroventricularly) of recombinant IL-1 receptor antagonist significantly reduced infarct volume in WT (-32%) and IL-1alpha KO (-48%) mice, but had no effect on injury in IL-1beta or IL-1alpha/beta KO mice. These data confirm that IL-1 plays a major role in ischemic brain injury. They also show that chronic deletion of IL-1alpha or IL-1beta fails to influence brain damage, probably because of compensatory changes in the IL-1 system in IL-1alpha KO mice and changes in IL-1-independent mediators of neuronal death in IL-1beta KO mice.

  3. Differential roles of ATM- and Chk2-mediated phosphorylations of Hdmx in response to DNA damage.

    Science.gov (United States)

    Pereg, Yaron; Lam, Suzanne; Teunisse, Amina; Biton, Sharon; Meulmeester, Erik; Mittelman, Leonid; Buscemi, Giacomo; Okamoto, Koji; Taya, Yoichi; Shiloh, Yosef; Jochemsen, Aart G

    2006-09-01

    The p53 tumor suppressor plays a major role in maintaining genomic stability. Its activation and stabilization in response to double strand breaks (DSBs) in DNA are regulated primarily by the ATM protein kinase. ATM mediates several posttranslational modifications on p53 itself, as well as phosphorylation of p53's essential inhibitors, Hdm2 and Hdmx. Recently we showed that ATM- and Hdm2-dependent ubiquitination and subsequent degradation of Hdmx following DSB induction are mediated by phosphorylation of Hdmx on S403, S367, and S342, with S403 being targeted directly by ATM. Here we show that S367 phosphorylation is mediated by the Chk2 protein kinase, a downstream kinase of ATM. This phosphorylation, which is important for subsequent Hdmx ubiquitination and degradation, creates a binding site for 14-3-3 proteins which controls nuclear accumulation of Hdmx following DSBs. Phosphorylation of S342 also contributed to optimal 14-3-3 interaction and nuclear accumulation of Hdmx, but phosphorylation of S403 did not. Our data indicate that binding of a 14-3-3 dimer and subsequent nuclear accumulation are essential steps toward degradation of p53's inhibitor, Hdmx, in response to DNA damage. These results demonstrate a sophisticated control by ATM of a target protein, Hdmx, which itself is one of several ATM targets in the ATM-p53 axis of the DNA damage response.

  4. The role of glutamate and the immune system in organophosphate-induced CNS damage.

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    Eisenkraft, Arik; Falk, Avshalom; Finkelstein, Arseny

    2013-08-01

    Organophosphate (OP) poisoning is associated with long-lasting neurological damage, which is attributed mainly to the excessive levels of glutamate caused by the intoxication. Glutamate toxicity, however, is not specific to OP poisoning, and is linked to propagation of damage in both acute and chronic neurodegenerative conditions in the central nervous system (CNS). In addition to acute excitotoxic effects of glutamate, there is now a growing amount of evidence of its intricate immunomodulatory effects in the brain, involving both the innate and the adaptive immune systems. Moreover, it was demonstrated that immunomodulatory treatments, aimed at regulating the interaction between the resident immune cells of the brain (microglia) and the peripheral immune system, can support buffering of excessive levels of glutamate and restoration of the homeostasis. In this review, we will discuss the role of glutamate as an excitotoxic agent in the acute phase of OP poisoning, and the possible functions it may have as both a neuroprotectant and an immunomodulator in the sub-acute and chronic phases of OP poisoning. In addition, we will describe the novel immune-based neuroprotective strategies aimed at counteracting the long-term neurodegenerative effects of glutamate in the CNS.

  5. Hydroxytyrosol inhibits hydrogen peroxide-induced apoptotic signaling via labile iron chelation

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    Natalia Kitsati

    2016-12-01

    Full Text Available Although it is known that Mediterranean diet plays an important role in maintaining human health, the underlying molecular mechanisms remain largely unknown. The aim of this investigation was to elucidate the potential role of ortho-dihydroxy group containing natural compounds in H2O2-induced DNA damage and apoptosis. For this purpose, the main phenolic alcohols of olive oil, namely hydroxytyrosol and tyrosol, were examined for their ability to protect cultured cells under conditions of oxidative stress. A strong correlation was observed between the ability of hydroxytyrosol to mitigate intracellular labile iron level and the protection offered against H2O2-induced DNA damage and apoptosis. On the other hand, tyrosol, which lacks the ortho-dihydroxy group, was ineffective. Moreover, hydroxytyrosol (but not tyrosol, was able to diminish the late sustained phase of H2O2-induced JNK and p38 phosphorylation. The derangement of intracellular iron homeostasis, following exposure of cells to H2O2, played pivotal role both in the induction of DNA damage and the initiation of apoptotic signaling. The presented results suggest that the protective effects exerted by ortho-dihydroxy group containing dietary compounds against oxidative stress-induced cell damage are linked to their ability to influence changes in the intracellular labile iron homeostasis.

  6. Protective role of hydrogen sulfide against noise-induced cochlear damage: a chronic intracochlear infusion model.

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    Xu Li

    Full Text Available BACKGROUND: A reduction in cochlear blood flow plays an essential role in noise-induced hearing loss (NIHL. The timely regulation of cochlear perfusion determines the progression and prognosis of NIHL. Hydrogen sulfide (H(2S has attracted increasing interest as a vasodilator in cardiovascular systems. This study identified the role of H(2S in cochlear blood flow regulation and noise protection. METHODOLOGY/PRINCIPAL FINDINGS: The gene and protein expression of the H(2S synthetase cystathionine-γ-lyase (CSE in the rat cochlea was examined using immunofluorescence and real-time PCR. Cochlear CSE mRNA levels varied according to the duration of noise exposure. A chronic intracochlear infusion model was built and artificial perilymph (AP, NaHS or DL-propargylglycine (PPG were locally administered. Local sodium hydrosulfide (NaHS significantly increased cochlear perfusion post-noise exposure. Cochlear morphological damage and hearing loss were alleviated in the NaHS group as measured by conventional auditory brainstem response (ABR, cochlear scanning electron microscope (SEM and outer hair cell (OHC count. The highest percentage of OHC loss occurred in the PPG group. CONCLUSIONS/SIGNIFICANCE: Our results suggest that H(2S plays an important role in the regulation of cochlear blood flow and the protection against noise. Further studies may identify a new preventive and therapeutic perspective on NIHL and other blood supply-related inner ear diseases.

  7. HIC1 (hypermethylated in cancer 1) SUMOylation is dispensable for DNA repair but is essential for the apoptotic DNA damage response (DDR) to irreparable DNA double-strand breaks (DSBs).

    Science.gov (United States)

    Paget, Sonia; Dubuissez, Marion; Dehennaut, Vanessa; Nassour, Joe; Harmon, Brennan T; Spruyt, Nathalie; Loison, Ingrid; Abbadie, Corinne; Rood, Brian R; Leprince, Dominique

    2017-01-10

    The tumor suppressor gene HIC1 (Hypermethylated In Cancer 1) encodes a transcriptional repressor mediating the p53-dependent apoptotic response to irreparable DNA double-strand breaks (DSBs) through direct transcriptional repression of SIRT1. HIC1 is also essential for DSB repair as silencing of endogenous HIC1 in BJ-hTERT fibroblasts significantly delays DNA repair in functional Comet assays. HIC1 SUMOylation favours its interaction with MTA1, a component of NuRD complexes. In contrast with irreparable DSBs induced by 16-hours of etoposide treatment, we show that repairable DSBs induced by 1 h etoposide treatment do not increase HIC1 SUMOylation or its interaction with MTA1. Furthermore, HIC1 SUMOylation is dispensable for DNA repair since the non-SUMOylatable E316A mutant is as efficient as wt HIC1 in Comet assays. Upon induction of irreparable DSBs, the ATM-mediated increase of HIC1 SUMOylation is independent of its effector kinase Chk2. Moreover, irreparable DSBs strongly increase both the interaction of HIC1 with MTA1 and MTA3 and their binding to the SIRT1 promoter. To characterize the molecular mechanisms sustained by this increased repression potential, we established global expression profiles of BJ-hTERT fibroblasts transfected with HIC1-siRNA or control siRNA and treated or not with etoposide. We identified 475 genes potentially repressed by HIC1 with cell death and cell cycle as the main cellular functions identified by pathway analysis. Among them, CXCL12, EPHA4, TGFβR3 and TRIB2, also known as MTA1 target-genes, were validated by qRT-PCR analyses. Thus, our data demonstrate that HIC1 SUMOylation is important for the transcriptional response to non-repairable DSBs but dispensable for DNA repair.

  8. When genome integrity and cell cycle decisions collide: roles of polo kinases in cellular adaptation to DNA damage.

    Science.gov (United States)

    Serrano, Diego; D'Amours, Damien

    2014-09-01

    The drive to proliferate and the need to maintain genome integrity are two of the most powerful forces acting on biological systems. When these forces enter in conflict, such as in the case of cells experiencing DNA damage, feedback mechanisms are activated to ensure that cellular proliferation is stopped and no further damage is introduced while cells repair their chromosomal lesions. In this circumstance, the DNA damage response dominates over the biological drive to proliferate, and may even result in programmed cell death if the damage cannot be repaired efficiently. Interestingly, the drive to proliferate can under specific conditions overcome the DNA damage response and lead to a reactivation of the proliferative program in checkpoint-arrested cells. This phenomenon is known as adaptation to DNA damage and is observed in all eukaryotic species where the process has been studied, including normal and cancer cells in humans. Polo-like kinases (PLKs) are critical regulators of the adaptation response to DNA damage and they play key roles at the interface of cell cycle and checkpoint-related decisions in cells. Here, we review recent progress in defining the specific roles of PLKs in the adaptation process and how this conserved family of eukaryotic kinases can integrate the fundamental need to preserve genomic integrity with effective cellular proliferation.

  9. The critical role of myeloperoxidase in Streptococcus pneumoniae clearance and tissue damage during mouse acute otitis media.

    Science.gov (United States)

    Xiang, Yun; Jin, Chunfang; Wang, Wei; Wang, Zimeng; Huang, Yifei; Fan, Fangmei; Ma, Yurong; Zhang, Xuemei; Xu, Wenchun; Yin, Yibing; He, Yujuan

    2017-04-01

    We have recently reported that neutrophils play a pivotal role in innate defense against Streptococcus pneumoniae ( Spn) during mouse acute otitis media (AOM). However, the underlying mechanism remains unclear. By constructing models of pneumococcal AOM in C57BL/6 mice and using a specific inhibitor in vivo, we investigated the role of myeloperoxidase (MPO), one of the most important protein components of neutrophils. Experiment results showed a significant increase in MPO production of the recruited neutrophils in Spn-infected mice. Neutrophils killed Spn in a MPO-dependent manner. MPO facilitated the generation of reactive oxygen species (ROS), and consequently promoted Spn clearance at an early stage and exacerbated tissue damage. Moreover, MPO induced neutrophil apoptosis and necrosis, which, in turn, worsened tissue damage. In summary, our study demonstrates that neutrophil MPO plays a paradoxical role in bacterial clearance and tissue damage in pneumococcal AOM.

  10. The Role of Altered Nucleotide Excision Repair and UVB-Induced DNA Damage in Melanomagenesis

    Directory of Open Access Journals (Sweden)

    Timothy Budden

    2013-01-01

    Full Text Available UVB radiation is the most mutagenic component of the UV spectrum that reaches the earth’s surface and causes the development of DNA damage in the form of cyclobutane pyrimidine dimers and 6-4 photoproducts. UV radiation usually results in cellular death, but if left unchecked, it can affect DNA integrity, cell and tissue homeostasis and cause mutations in oncogenes and tumour-suppressor genes. These mutations, if unrepaired, can lead to abnormal cell growth, increasing the risk of cancer development. Epidemiological data strongly associates UV exposure as a major factor in melanoma development, but the exact biological mechanisms involved in this process are yet to be fully elucidated. The nucleotide excision repair (NER pathway is responsible for the repair of UV-induced lesions. Patients with the genetic disorder Xeroderma Pigmentosum have a mutation in one of eight NER genes associated with the XP complementation groups XP-A to XP-G and XP variant (XP-V. XP is characterized by diminished repair capacity, as well as a 1000-fold increase in the incidence of skin cancers, including melanoma. This has suggested a significant role for NER in melanoma development as a result of UVB exposure. This review discusses the current research surrounding UVB radiation and NER capacity and how further investigation of NER could elucidate the role of NER in avoiding UV-induced cellular death resulting in melanomagenesis.

  11. Phospho-Bcl-x(L)(Ser62) plays a key role at DNA damage-induced G(2) checkpoint.

    Science.gov (United States)

    Wang, Jianfang; Beauchemin, Myriam; Bertrand, Richard

    2012-06-01

    Accumulating evidence suggests that Bcl-xL, an anti-apoptotic member of the Bcl-2 family, also functions in cell cycle progression and cell cycle checkpoints. Analysis of a series of phosphorylation site mutants reveals that cells expressing Bcl-xL(Ser62Ala) mutant are less stable at the G 2 checkpoint and enter mitosis more rapidly than cells expressing wild-type Bcl-xL or Bcl-xL phosphorylation site mutants, including Thr41Ala, Ser43Ala, Thr47Ala, Ser56Ala and Thr115Ala. Analysis of the dynamic phosphorylation and location of phospho-Bcl-xL(Ser62) in unperturbed, synchronized cells and during DNA damage-induced G 2 arrest discloses that a pool of phospho-Bcl-xL(Ser62) accumulates into nucleolar structures in etoposide-exposed cells during G 2 arrest. In a series of in vitro kinase assays, pharmacological inhibitors and specific siRNAs experiments, we found that Polo kinase 1 and MAPK9/JNK2 are major protein kinases involved in Bcl-xL(Ser62) phosphorylation and accumulation into nucleolar structures during the G 2 checkpoint. In nucleoli, phospho-Bcl-xL(Ser62) binds to and co-localizes with Cdk1(cdc2), the key cyclin-dependent kinase required for entry into mitosis. These data indicate that during G 2 checkpoint, phospho-Bcl-xL(Ser62) stabilizes G 2 arrest by timely trapping of Cdk1(cdc2) in nucleolar structures to slow mitotic entry. It also highlights that DNA damage affects the dynamic composition of the nucleolus, which now emerges as a piece of the DNA damage response.

  12. Leucocytes, cytokines and satellite cells: what role do they play in muscle damage and regeneration following eccentric exercise?

    Science.gov (United States)

    Paulsen, Gøran; Mikkelsen, Ulla Ramer; Raastad, Truls; Peake, Jonathan M

    2012-01-01

    Exercise-induced muscle damage is an important topic in exercise physiology. However several aspects of our understanding of how muscles respond to highly stressful exercise remain unclear In the first section of this review we address the evidence that exercise can cause muscle damage and inflammation in otherwise healthy human skeletal muscles. We approach this concept by comparing changes in muscle function (i.e., the force-generating capacity) with the degree of leucocyte accumulation in muscle following exercise. In the second section, we explore the cytokine response to 'muscle-damaging exercise', primarily eccentric exercise. We review the evidence for the notion that the degree of muscle damage is related to the magnitude of the cytokine response. In the third and final section, we look at the satellite cell response to a single bout of eccentric exercise, as well as the role of the cyclooxygenase enzymes (COX1 and 2). In summary, we propose that muscle damage as evaluated by changes in muscle function is related to leucocyte accumulation in the exercised muscles. 'Extreme' exercise protocols, encompassing unaccustomed maximal eccentric exercise across a large range of motion, generally inflict severe muscle damage, inflammation and prolonged recovery (> 1 week). By contrast, exercise resembling regular athletic training (resistance exercise and downhill running) typically causes mild muscle damage (myofibrillar disruptions) and full recovery normally occurs within a few days. Large variation in individual responses to a given exercise should, however be expected. The link between cytokine and satellite cell responses and exercise-induced muscle damage is not so clear The systemic cytokine response may be linked more closely to the metabolic demands of exercise rather than muscle damage. With the exception of IL-6, the sources of systemic cytokines following exercise remain unclear The satellite cell response to severe muscle damage is related to

  13. Apoptotic pathways as a therapeutic target for colorectal cancer treatment

    Institute of Scientific and Technical Information of China (English)

    Aman M Abraha; Ezra B Ketema

    2016-01-01

    Colorectal cancer is the second leading cause of death from cancer among adults. The disease begins as a benign adenomatous polyp, which develops into an advanced adenoma with high-grade dysplasia and then progresses to an invasive cancer. Appropriate apoptotic signaling is fundamentally important to preserve a healthy balance between cell death and cell survival and in maintaining genome integrity. Evasion of apoptotic pathway has been established as a prominent hallmark of several cancers. During colorectal cancer development, the balance between the rates of cell growth and apoptosis that maintains intestinal epithelial cell homeostasis gets progressively disturbed. Evidences are increasingly available to support the hypothesis that failure of apoptosis may be an important factor in the evolution of colorectal cancer and its poor response to chemotherapy and radiation. The other reason for targeting apoptotic pathway in the treatment of cancer is based on the observation that this process is deregulated in cancer cells but not in normal cells. As a result, colorectal cancer therapies designed to stimulate apoptosis in target cells would play a critical role in controlling its development and progression. A better understanding of the apoptotic signaling pathways, and the mechanisms by which cancer cells evade apoptotic death might lead to effective therapeutic strategies to inhibit cancer cell proliferation with minimal toxicity and high responses to chemotherapy. In this review, we analyzed the current understanding and future promises of apoptotic pathways as a therapeutic target in colorectal cancer treatment.

  14. Cytosolic pro-apoptotic SPIKE induces mitochondrial apoptosis in cancer.

    Science.gov (United States)

    Nikolic, Ivana; Kastratovic, Tatjana; Zelen, Ivanka; Zivanovic, Aleksandar; Arsenijevic, Slobodan; Mitrovic, Marina

    2010-04-30

    Proteins of the BCL-2 family are important regulators of apoptosis. The BCL-2 family includes three main subgroups: the anti-apoptotic group, such as BCL-2, BCL-XL, BCL-W, and MCL-1; multi-domain pro-apoptotic BAX, BAK; and pro-apoptotic "BH3-only" BIK, PUMA, NOXA, BID, BAD, and SPIKE. SPIKE, a rare pro-apoptotic protein, is highly conserved throughout the evolution, including Caenorhabditis elegans, whose expression is downregulated in certain tumors, including kidney, lung, and breast. In the literature, SPIKE was proposed to interact with BAP31 and prevent BCL-XL from binding to BAP31. Here, we utilized the Position Weight Matrix method to identify SPIKE to be a BH3-only pro-apoptotic protein mainly localized in the cytosol of all cancer cell lines tested. Overexpression of SPIKE weakly induced apoptosis in comparison to the known BH3-only pro-apoptotic protein BIK. SPIKE promoted mitochondrial cytochrome c release, the activation of caspase 3, and the caspase cleavage of caspase's downstream substrates BAP31 and p130CAS. Although the informatics analysis of SPIKE implicates this protein as a member of the BH3-only BCL-2 subfamily, its role in apoptosis remains to be elucidated.

  15. Allograft tolerance induced by donor apoptotic lymphocytes requires phagocytosis in the recipient

    Science.gov (United States)

    Sun, E.; Gao, Y.; Chen, J.; Roberts, A. I.; Wang, X.; Chen, Z.; Shi, Y.

    2004-01-01

    Cell death through apoptosis plays a critical role in regulating cellular homeostasis. Whether the disposal of apoptotic cells through phagocytosis can actively induce immune tolerance in vivo, however, remains controversial. Here, we report in a rat model that without using immunosuppressants, transfusion of apoptotic splenocytes from the donor strain prior to transplant dramatically prolonged survival of heart allografts. Histological analysis verified that rejection signs were significantly ameliorated. Splenocytes from rats transfused with donor apoptotic cells showed a dramatically decreased response to donor lymphocyte stimulation. Most importantly, blockade of phagocytosis in vivo, either with gadolinium chloride to disrupt phagocyte function or with annexin V to block binding of exposed phosphotidylserine to its receptor on phagocytes, abolished the beneficial effect of transfused apoptotic cells on heart allograft survival. Our results demonstrate that donor apoptotic cells promote specific allograft acceptance and that phagocytosis of apoptotic cells in vivo plays a crucial role in maintaining immune tolerance.

  16. Oxidative damages in tubular epithelial cells in IgA nephropathy: role of crosstalk between angiotensin II and aldosterone

    Directory of Open Access Journals (Sweden)

    Lim Ai-Ing

    2011-10-01

    Full Text Available Abstract Background Inhibition of the renin-angiotensin-aldosterone system (RAAS slows down the progression of chronic renal diseases (CKD including IgA nephropathy (IgAN. Herein, we studied the pathogenetic roles of aldosterone (Aldo in IgAN. Methods Human mesangial cells (HMC was activated with polymeric IgA (pIgA from IgAN patients and the effects on the expression of RAAS components and TGF-β synthesis examined. To study the roles of RAAS in the glomerulotubular communication, proximal tubular epithelial cells (PTEC was cultured with conditioned medium from pIgA-activated HMC with eplerenone or PD123319, the associated apoptotic event was measured by the generation of nicotinamide adenine dinucleotide phosphate (NADPH oxidase and reactive oxygen species (ROS. Results Polymeric IgA up-regulated the Aldo synthesis and aldosterone synthase expression by HMC. The release of TGF-β by HMC was up-regulated synergistically by AngII and Aldo and this was inhibited by incubation of HMC with losartan plus eplerenone. Cultured PTEC express the mineralocorticoid receptor, but not synthesizing aldosterone. Apoptosis, demonstrated by cleaved PARP expression and caspase 3 activity, was induced in PTEC activated by conditioned medium prepared from HMC cultured with pIgA from IgAN patients. This apoptotic event was associated with increased generation of NADPH oxidase and ROS. Pre-incubation of PTEC with PD123319 and eplerenone achieved complete inhibition of PTEC apoptosis. Conclusions Our data suggest that AngII and Aldo, released by pIgA activated HMC, served as mediators for inducing apoptosis of PTEC in glomerulo-tubular communications. Crosstalk between AngII and Aldo could participate in determining the tubular pathology of IgAN.

  17. Teratogen-induced apoptotic cell death: does the apoptotic machinery act as a protector of embryos exposed to teratogens?

    Science.gov (United States)

    Torchinsky, Arkady; Fein, Amos; Toder, Vladimir

    2005-12-01

    Considerable evidence has been collected demonstrating that many teratogens induce apoptotic cell death in embryonic structures that turn out to be malformed in fetuses and newborns. Apoptosis is a genetically regulated process that is realized by the activation of death and pro-survival signaling cascades, and the interplay between these cascades determines whether the cell exposed to apoptotic stimuli dies or survives. Therefore, there is intense interest in understanding how the apoptotic machinery functions in embryos exposed to teratogens. However, the interpretation of the results obtained remains problematic. The main problem is that excessive embryonic cell death, regardless of its nature, if uncompensated for, ultimately leads to maldevelopment or embryonic death. Therefore, we can easily interpret results when the intensity of teratogen-induced cell death and the severity or incidence of teratogen-induced anomalies directly correlate with each other. However, when teratogen-induced cell death is not followed by the formation of anomalies, a usual explanation is that teratogen-induced apoptotic cell death contributes to the renewal of teratogen-targeted cell populations by promoting the removal of injured cells. It is clear that such an explanation leaves vague the role of the anti-apoptotic signaling mechanism (and, hence, the apoptotic machinery as a whole) with respect to protecting the embryo against teratogenic stress. In this review, we summarize the data from studies addressing the function of the apoptotic machinery in embryos exposed to teratogens, and then we discuss approaches to interpreting the results of these studies. We hypothesize that activation of a proapoptotic signaling in teratogen-targeted cell populations is a necessary condition for an anti-apoptotic signaling that counteracts the process of maldevelopment to be activated. If such a scenario is true, we need to modify our approaches to choosing molecular targets for studies

  18. Role of airway lactoperoxidase in scavenging of hydrogen peroxide damage in asthma

    Directory of Open Access Journals (Sweden)

    Al Obaidi Amina Hamed

    2007-01-01

    Full Text Available Hydrogen peroxide (H 2 O 2 that is mainly generated by neutrophils and eosinophils in asthma is known to be damaging to the airway and to contribute to airway inflammation. The purpose of the present study was to determine the contribution and the role of lactoperoxidase in scavenging airway hydrogen peroxide, in order to propose a therapeutic approach for asthma. The study was an open clinical trial. Twenty-five nonsmoking asthmatic patients were included in the study. Of them, 16 patients (64% were male and 9 (36% were female, with age ranging from 29 to 48 years (45.13 ± 4.6. Of the 25 patients included in the study, only 16 patients completed the study; and they were eligible for analyses. Exhaled breath condensate was collected from all patients at the time of entering the study; and 2, 4 and 8 weeks later. All patients received dapson as a lactoperoxidase inhibitor at a dose of 50 mg daily for 8 weeks. The study was conducted during the period from January 2006 to end of October 2006. H 2 O 2 concentration was determined by an enzymatic assay. Determination of exhaled breath condensate for hydrogen peroxide concentration after 8 weeks of dapson usage indicated an increase (1.05 ± 0.36 µM; 95% CI, 0.89-1.21 as compared to that at baseline ( P < 0.0001, 2 weeks ( P < 0.001 and 4 weeks ( P > 0.05. The increase in hydrogen peroxide concentration in exhaled breath condensate after inhibition of lactoperoxidase by dapson advocates a potential role for lactoperoxidase in scavenging of hydrogen peroxide in asthmatic airway.

  19. Damaged DNA binding protein 2 plays a role in breast cancer cell growth.

    Directory of Open Access Journals (Sweden)

    Zilal Kattan

    Full Text Available The Damaged DNA binding protein 2 (DDB2, is involved in nucleotide excision repair as well as in other biological processes in normal cells, including transcription and cell cycle regulation. Loss of DDB2 function may be related to tumor susceptibility. However, hypothesis of this study was that DDB2 could play a role in breast cancer cell growth, resulting in its well known interaction with the proliferative marker E2F1 in breast neoplasia. DDB2 gene was overexpressed in estrogen receptor (ER-positive (MCF-7 and T47D, but not in ER-negative breast cancer (MDA-MB231 and SKBR3 or normal mammary epithelial cell lines. In addition, DDB2 expression was significantly (3.0-fold higher in ER-positive than in ER-negative tumor samples (P = 0.0208 from 16 patients with breast carcinoma. Knockdown of DDB2 by small interfering RNA in MCF-7 cells caused a decrease in cancer cell growth and colony formation. Inversely, introduction of the DDB2 gene into MDA-MB231 cells stimulated growth and colony formation. Cell cycle distribution and 5 Bromodeoxyuridine incorporation by flow cytometry analysis showed that the growth-inhibiting effect of DDB2 knockdown was the consequence of a delayed G1/S transition and a slowed progression through the S phase of MCF-7 cells. These results were supported by a strong decrease in the expression of S phase markers (Proliferating Cell Nuclear Antigen, cyclin E and dihydrofolate reductase. These findings demonstrate for the first time that DDB2 can play a role as oncogene and may become a promising candidate as a predictive marker in breast cancer.

  20. Systems-wide analysis of ubiquitylation dynamics reveals a key role for PAF15 ubiquitylation in DNA-damage bypass

    DEFF Research Database (Denmark)

    Povlsen, Lou K; Beli, Petra; Wagner, Sebastian A;

    2012-01-01

    components of DNA-damage signalling, as well as on proteins not previously implicated in this process. Our results uncover a critical role for PCNA-associated factor PAF15 (p15(PAF)/KIAA0101) ubiquitylation during DNA replication. During unperturbed S phase, chromatin-associated PAF15 is modified by double...

  1. Protective natural autoantibodies to apoptotic cells: evidence of convergent selection of recurrent innate-like clones.

    Science.gov (United States)

    Silverman, Gregg J

    2015-12-01

    During murine immune development, recurrent B cell clones arise in a predictable fashion. Among these B cells, an archetypical clonotypic set that recognizes phosphorylcholine (PC) antigens and produces anti-PC IgM, first implicated for roles in microbial protection, was later found to become expanded in hyperlipidemic mice and in response to an increased in vivo burden of apoptotic cells. These IgM natural antibodies can enhance clearance of damaged cells and induce intracellular blockade of inflammatory signaling cascades. In clinical populations, raised levels of anti-PC IgM correlate with protection from atherosclerosis and may also downmodulate the severity of autoimmune disease. Human anti-PC-producing clones without hypermutation have been isolated that can similarly discriminate apoptotic from healthy cells. An independent report on unrelated adults has described anti-PC-producing B cells with IgM genes that have conserved CDR3 motifs, similar to stereotypic clonal sets of B cell chronic lymphocytic leukemia. Taken together, emerging evidence suggests that, despite the capacity to form an effectively limitless range of Ig receptors, the human immune system may often recurrently generate lymphocytes expressing structurally convergent B cell receptors with protective and homeostatic roles.

  2. Proteomic investigations reveal a role for RNA processing factor THRAP3 in the DNA damage response

    DEFF Research Database (Denmark)

    Beli, Petra; Lukashchuk, Natalia; Wagner, Sebastian A

    2012-01-01

    The regulatory networks of the DNA damage response (DDR) encompass many proteins and posttranslational modifications. Here, we use mass spectrometry-based proteomics to analyze the systems-wide response to DNA damage by parallel quantification of the DDR-regulated phosphoproteome, acetylome, and ...

  3. Role of Rad54, Rad54b and Snm1 in DNA damage repair

    NARCIS (Netherlands)

    J. Wesoly (Joanna)

    2003-01-01

    textabstractThe aim of this thesis is to investigate the function of a number of genes involved in mammalian DNA damage repair, in particular in repair of DNA double-strand breaks (DSBs). Among a large number of different damages that can be introduced to DNA, DSBs are especially toxic. If left unre

  4. Phosphorylation of Puma modulates its apoptotic function by regulating protein stability

    OpenAIRE

    M. Fricker; O'Prey, J; Tolkovsky, A. M.; Ryan, K.M.

    2010-01-01

    Puma is a potent BH3-only protein that antagonises anti-apoptotic Bcl-2 proteins, promotes Bax/Bak activation and has an essential role in multiple apoptotic models. Puma expression is normally kept very low, but can be induced by several transcription factors including p53, p73, E2F1 and FOXO3a, whereby it can induce an apoptotic response. As Puma can to bind and inactivate all anti-apoptotic members of the Bcl-2 family, its activity must be tightly controlled. We report here, for the first ...

  5. Apoptotic markers in protozoan parasites

    Directory of Open Access Journals (Sweden)

    Fasel Nicolas

    2010-11-01

    Full Text Available Abstract The execution of the apoptotic death program in metazoans is characterized by a sequence of morphological and biochemical changes that include cell shrinkage, presentation of phosphatidylserine at the cell surface, mitochondrial alterations, chromatin condensation, nuclear fragmentation, membrane blebbing and the formation of apoptotic bodies. Methodologies for measuring apoptosis are based on these markers. Except for membrane blebbing and formation of apoptotic bodies, all other events have been observed in most protozoan parasites undergoing cell death. However, while techniques exist to detect these markers, they are often optimised for metazoan cells and therefore may not pick up subtle differences between the events occurring in unicellular organisms and multi-cellular organisms. In this review we discuss the markers most frequently used to analyze cell death in protozoan parasites, paying special attention to changes in cell morphology, mitochondrial activity, chromatin structure and plasma membrane structure/permeability. Regarding classical regulators/executors of apoptosis, we have reviewed the present knowledge of caspase-like and nuclease activities.

  6. Apoptotic markers in protozoan parasites.

    Science.gov (United States)

    Jiménez-Ruiz, Antonio; Alzate, Juan Fernando; Macleod, Ewan Thomas; Lüder, Carsten Günter Kurt; Fasel, Nicolas; Hurd, Hilary

    2010-11-09

    The execution of the apoptotic death program in metazoans is characterized by a sequence of morphological and biochemical changes that include cell shrinkage, presentation of phosphatidylserine at the cell surface, mitochondrial alterations, chromatin condensation, nuclear fragmentation, membrane blebbing and the formation of apoptotic bodies. Methodologies for measuring apoptosis are based on these markers. Except for membrane blebbing and formation of apoptotic bodies, all other events have been observed in most protozoan parasites undergoing cell death. However, while techniques exist to detect these markers, they are often optimised for metazoan cells and therefore may not pick up subtle differences between the events occurring in unicellular organisms and multi-cellular organisms.In this review we discuss the markers most frequently used to analyze cell death in protozoan parasites, paying special attention to changes in cell morphology, mitochondrial activity, chromatin structure and plasma membrane structure/permeability. Regarding classical regulators/executors of apoptosis, we have reviewed the present knowledge of caspase-like and nuclease activities.

  7. Apoptotic Capacity and Risk of Squamous Cell Carcinoma of the Head and Neck

    Science.gov (United States)

    Liu, Zhensheng; Liu, Hongliang; Han, Peng; Gao, Fengqin; Dahlstrom, Kristina R.; Li, Guojun; Owzar, Kouros; Zevallos, Jose P.; Sturgis, Erich M.; Wei, Qingyi

    2017-01-01

    Background Tobacco smoke and alcohol drinking are the major risk factors for squamous cell carcinoma of the head and neck (SCCHN). Smoking and drinking cause DNA damage leading to apoptosis, and insufficient apoptotic capacity may favor development of cancer because of the dysfunction of removing damaged cells. In the present study, we investigated the association between camptothecin (CPT)-induced apoptotic capacity and risk of SCCHN in a North American population. Methods In a case-control study of 708 SCCHN patients and 685 matched cancer-free controls, we measured apoptotic capacity in cultured peripheral blood lymphocytes (PBLs) in response to in vitro exposure to CPT by using the flow cytometry-based method. Results We found that the mean level of apoptotic capacity in the cases (45.9±23.3%) was significantly lower than that in the controls (49.0±23.1%) (P = 0.002). When we used the median level of apoptotic capacity in the controls as the cutoff value for calculating adjusted odds ratios (ORs), subjects with a reduced apoptotic capacity had an increased risk (adjusted OR = 1.42, 95% confidence interval [CI] = 1.13–1.78, P = 0.002), especially for those who were age ≥57 (1.73, 1.25–2.38, 0.0009), men (1.76, 1.36–2.27, < 0.0001) and ever drinkers (1.67, 1.27–2.21, 0.0003), and these variables significantly interacted with apoptotic capacity (Pinteraction = 0.015, 0.005 and 0.009, respectively). A further fitted prediction model suggested that the inclusion of apoptotic capacity significantly improved in the prediction of SCCHN risk. Conclusion Individuals with a reduced CPT-induced apoptotic capacity may be at an increased risk of developing SCCHN, and apoptotic capacity may be a biomarker for susceptibility to SCCHN. PMID:28033527

  8. The role of intracellular zinc in chromium(VI)-induced oxidative stress, DNA damage and apoptosis.

    Science.gov (United States)

    Rudolf, Emil; Cervinka, Miroslav

    2006-09-25

    Several studies have demonstrated that zinc is required for the optimal functioning of the skin. Changes in intracellular zinc concentrations have been associated with both improved protection of skin cells against various noxious factors as well as with increased susceptibility to external stress. Still, little is known about the role of intracellular zinc in hexavalent chromium (Cr(VI))-induced skin injury. To address this question, the effects of zinc deficiency or supplementation on Cr(VI)-induced cytotoxicity, oxidative stress, DNA injury and cell death were investigated in human diploid dermal fibroblasts during 48 h. Zinc levels in fibroblasts were manipulated by pretreatment of cells with 100 microM ZnSO4 and 4 or 25 microM zinc chelator TPEN. Cr(VI) (50, 10 and 1 microM) was found to produce time- and dose-dependent cytotoxicity resulting in oxidative stress, suppression of antioxidant systems and activation of p53-dependent apoptosis which is reported for the first time in this model in relation to environmental Cr(VI). Increased intracellular zinc partially attenuated Cr(VI)-induced cytotoxicity, oxidative stress and apoptosis by enhancing cellular antioxidant systems while inhibiting Cr(VI)-dependent apoptosis by preventing the activation of caspase-3. Decreased intracellular zinc enhanced cytotoxic effects of all the tested Cr(VI) concentrations, leading to rapid loss of cell membrane integrity and nuclear dispersion--hallmarks of necrosis. These new findings suggest that Cr(VI) as a model environmental toxin may damage in deeper regions residing skin fibroblasts whose susceptibility to such toxin depends among others on their intracellular Zn levels. Further investigation of the impact of Zn status on skin cells as well as any other cell populations exposed to Cr(VI) or other heavy metals is warranted.

  9. Cardioprotective role of tadalafil against cisplatin-induced cardiovascular damage in rats.

    Science.gov (United States)

    Saleh, Rasha M; Awadin, Walaa F; El-Shafei, Reham A; Elseady, Yousef Y; Wehaish, Faheim E; Elshal, Mohamed F

    2015-10-15

    The present study investigated the possible cardioprotective effect of tadalafil (Tad) on cisplatin (CDDP)-induced cardiac and vascular damages in rats. A total number of seventy two healthy male albino rats initially weighting between 200 and 220 g were used and randomly divided into four groups,18 rats in each. The control group received no treatment; CDDP group received a single dose of CDDP (4 mg/kg) intraperitoneal (i.p.) per week for 4 weeks the duration of the experiment; Tad group received 0.4 mg/kg BW Tad i.p. daily and Tad +CDDP group received 0.4 mg/kg BW Tad i.p. +4 mg/kg BW CDDP i.p. The results showed that Tad was able to decrease blood pressure, heart rate, levels of serum cardiac troponin (cTn-I), malondialdehyde (MDA) and increased levels of reduced glutathione (GSH) and nitric oxide (NO) in the heart homogenate sample from CDDP treated rats. Semi-quantitative analysis showed that Tad was able to decrease the histopathological scores of cardiac muscular hyalinzation and fibrosis in three sacrifices in CDDP treated rats. CDDP treated rats showed significantly increased thickening in wall of aorta with an irregular luminal layer of endothelial cell linings in three sacrifices when it was compared to other groups. Moreover, immunohistochemical labeling of α- smooth muscle actin (α-SMA) in aorta revealed significant lower scores in Tad +CDDP group when they were compared to CDDP group. In conclusion, Tad alone did not induce any harmful effects on blood pressure, selective antioxidant, peroxidation markers or cardiac histology, in addition, Tad has a cardio-protective role against CDDP.

  10. The role of hnRPUL1 involved in DNA damage response is related to PARP1.

    Directory of Open Access Journals (Sweden)

    Zehui Hong

    Full Text Available Heterogeneous nuclear ribonucleoprotein U-like 1 (hnRPUL1 -also known as adenovirus early region 1B-associated proteins 5 (E1B-AP5 - plays a role in RNA metabolism. Recently, hnRPUL1 has also been shown to be involved in DNA damage response, but the function of hnRPUL1 in response to DNA damage remains unclear. Here, we have demonstrated that hnRPUL1 is associated with PARP1 and recruited to DNA double-strand breaks (DSBs sites in a PARP1-mediated poly (ADP-ribosyl ation dependent manner. In turn, hnRPUL1 knockdown enhances the recruitment of PARP1 to DSBs sites. Specifically, we showed that hnRPUL1 is also implicated in the transcriptional regulation of PARP1 gene. Thus, we propose hnRPUL1 as a new component related to PARP1 in DNA damage response and repair.

  11. A p53-independent role for the MDM2 antagonist Nutlin-3 in DNA damage response initiation

    Directory of Open Access Journals (Sweden)

    Kumar Sonia

    2011-02-01

    Full Text Available Abstract Background The mammalian DNA-damage response (DDR has evolved to protect genome stability and maximize cell survival following DNA-damage. One of the key regulators of the DDR is p53, itself tightly regulated by MDM2. Following double-strand DNA breaks (DSBs, mediators including ATM are recruited to the site of DNA-damage. Subsequent phosphorylation of p53 by ATM and ATM-induced CHK2 results in p53 stabilization, ultimately intensifying transcription of p53-responsive genes involved in DNA repair, cell-cycle checkpoint control and apoptosis. Methods In the current study, we investigated the stabilization and activation of p53 and associated DDR proteins in response to treatment of human colorectal cancer cells (HCT116p53+/+ with the MDM2 antagonist, Nutlin-3. Results Using immunoblotting, Nutlin-3 was observed to stabilize p53, and activate p53 target proteins. Unexpectedly, Nutlin-3 also mediated phosphorylation of p53 at key DNA-damage-specific serine residues (Ser15, 20 and 37. Furthermore, Nutlin-3 induced activation of CHK2 and ATM - proteins required for DNA-damage-dependent phosphorylation and activation of p53, and the phosphorylation of BRCA1 and H2AX - proteins known to be activated specifically in response to DNA damage. Indeed, using immunofluorescent labeling, Nutlin-3 was seen to induce formation of γH2AX foci, an early hallmark of the DDR. Moreover, Nutlin-3 induced phosphorylation of key DDR proteins, initiated cell cycle arrest and led to formation of γH2AX foci in cells lacking p53, whilst γH2AX foci were also noted in MDM2-deficient cells. Conclusion To our knowledge, this is the first solid evidence showing a secondary role for Nutlin-3 as a DDR triggering agent, independent of p53 status, and unrelated to its role as an MDM2 antagonist.

  12. Role of mucus in the repair of gastric epithelial damage in the rat. Inhibition of epithelial recovery by mucolytic agents.

    Science.gov (United States)

    Wallace, J L; Whittle, B J

    1986-09-01

    A role for mucus in providing a microenvironment over sites of gastric damage, which is conducive to reepithelialization, has been proposed. We tested this hypothesis by examining the effects of disruption of such mucus on the recovery of epithelial integrity after damage induced by 50% ethanol. Exposure of an ex vivo chambered gastric mucosa to topically applied 50% ethanol resulted in copious release of mucus, cellular debris, and plasma, which formed a continuous cap over the mucosal surface. Ethanol-induced gastric damage was accompanied by extensive surface epithelial cell damage and a marked decrease in transmucosal potential difference. During the 30 min after ethanol was removed from the chamber, the epithelium became reestablished and the potential difference gradually recovered to 94% of the level before ethanol treatment. However, if the mucolytic agents N-acetylcysteine (5%) or pepsin (0.5%) were added to the bathing solutions, the "mucoid cap" disintegrated and the recovery of potential difference was significantly retarded (recovering to only 51% and 52% of levels before ethanol treatment). Histologic evaluation confirmed that mucosae treated with either agent had significantly less (p less than 0.005) intact epithelium at the end of the experiment. Removal of the mucoid cap with forceps caused a similar inhibition of the repair of the epithelium and the recovery of potential difference. Both mechanical and chemical (N-acetylcysteine) disruption of the mucoid cap resulted in a significant increase in the mucosal leakage of albumin and hemoglobin, supporting previous histologic evidence that the mucoid cap traps blood components over the damaged mucosa. These studies support the hypothesis that mucus released in response to topical application of an irritant plays an important role in the repair of epithelial damage through the process of restitution.

  13. Role of oxidative stress in impaired insulin signaling associated with exercise-induced muscle damage.

    Science.gov (United States)

    Aoi, Wataru; Naito, Yuji; Yoshikawa, Toshikazu

    2013-12-01

    Skeletal muscle is a major tissue that utilizes blood glucose. A single bout of exercise improves glucose uptake in skeletal muscle through insulin-dependent and insulin-independent signal transduction mechanisms. However, glucose utilization is decreased in muscle damage induced by acute, unaccustomed, or eccentric exercise. The decrease in glucose utilization is caused by decreased insulin-stimulated glucose uptake in damaged muscles with inhibition of the membrane translocation of glucose transporter 4 through phosphatidyl 3-kinase/Akt signaling. In addition to inflammatory cytokines, reactive oxygen species including 4-hydroxy-2-nonenal and peroxynitrate can induce degradation or inactivation of signaling proteins through posttranslational modification, thereby resulting in a disturbance in insulin signal transduction. In contrast, treatment with factors that attenuate oxidative stress in damaged muscle suppresses the impairment of insulin sensitivity. Muscle-damaging exercise may thus lead to decreased endurance capacity and muscle fatigue in exercise, and it may decrease the efficiency of exercise therapy for metabolic improvement.

  14. The Role of Mms22p in DNA Damage Response in Candida albicans.

    Science.gov (United States)

    Yan, Lan; Xiong, Juan; Lu, Hui; Lv, Quan-zhen; Ma, Qian-yao; Côte, Pierre; Whiteway, Malcolm; Jiang, Yuan-ying

    2015-12-01

    To ensure correct DNA replication, eukaryotes have signaling pathways that respond to replication-associated DNA damage and trigger repair. In both Saccharomyces cerevisiae and Schizosaccharomyces pombe, a complex of proteins, including the cullin protein Rtt101p and two adapter proteins Mms22p and Mms1p, is important for proper response to replication stress. We have investigated this system in Candida albicans. In this pathogen, Mms22p is important for recovery from DNA replication damage induced by agents including methylmethane sulfonate, camptothecin, and ionizing radiation. Although no clear ortholog of Mms1p has been identified in C. albicans, loss of either Mms22p or Rtt101p generates similar damage sensitivity, consistent with a common function. In S. cerevisiae, the Mrc1p-Csm3p-Tof1p complex stabilizes stalled replication forks and activates a replication checkpoint and interacts with Mms22p. A similar complex in S. pombe, consisting of the Tof1p and Csm3p orthologs Swi1p and Swi3p, along with the fission yeast Mrc1p, genetically also interacts with Mms22p. Intriguingly in C. albicans only Mrc1p and Csm3p appear involved in damage repair, and Mms22p is required for responding to DNA damage agents in MRC1 or CSM3 conditional mutants. In C. albicans, although the loss of RAD57 greatly impairs response in the pathogen to many DNA-damaging agents, lethality due to camptothecin damage requires concomitant loss of Rad57p and Mms22p, suggesting that Mms22p is only essential for homologous recombination induced by camptothecin. These results establish that although C. albicans uses conserved cellular modules to respond to DNA damage and replication blocks, the specific details of these modules differ significantly from the S. cerevisiae model.

  15. Sex chromosome inactivation in germ cells: emerging roles of DNA damage response pathways

    OpenAIRE

    Ichijima, Yosuke; Sin, Ho-Su; Satoshi H Namekawa

    2012-01-01

    Sex chromosome inactivation in male germ cells is a paradigm of epigenetic programming during sexual reproduction. Recent progress has revealed the underlying mechanisms of sex chromosome inactivation in male meiosis. The trigger of chromosome-wide silencing is activation of the DNA damage response (DDR) pathway, which is centered on the mediator of DNA damage checkpoint 1 (MDC1), a binding partner of phosphorylated histone H2AX (γH2AX). This DDR pathway shares features with the somatic DDR p...

  16. IFI16, an amplifier of DNA-damage response: Role in cellular senescence and aging-associated inflammatory diseases.

    Science.gov (United States)

    Choubey, Divaker; Panchanathan, Ravichandran

    2016-07-01

    DNA-damage induces a DNA-damage response (DDR) in mammalian cells. The response, depending upon the cell-type and the extent of DNA-damage, ultimately results in cell death or cellular senescence. DDR-induced signaling in cells activates the ATM-p53 and ATM-IKKα/β-interferon (IFN)-β signaling pathways, thus leading to an induction of the p53 and IFN-inducible IFI16 gene. Further, upon DNA-damage, DNA accumulates in the cytoplasm, thereby inducing the IFI16 protein and STING-dependent IFN-β production and activation of the IFI16 inflammasome, resulting in the production of proinflammatory cytokines (e.g., IL-1β and IL-18). Increased expression of IFI16 protein in a variety of cell-types promotes cellular senescence. However, reduced expression of IFI16 in cells promotes cell proliferation. Because expression of the IFI16 gene is induced by activation of DNA-damage response in cells and increased levels of IFI16 protein in cells potentiate the p53-mediated transcriptional activation of genes and p53 and pRb-mediated cell cycle arrest, we discuss how an improved understanding of the role of IFI16 protein in cellular senescence and associated inflammatory secretory phenotype is likely to identify the molecular mechanisms that contribute to the development of aging-associated human inflammatory diseases and a failure to cancer therapy.

  17. Essential and distinct roles of the F-box and helicase domains of Fbh1 in DNA damage repair

    Directory of Open Access Journals (Sweden)

    Shinagawa Hideo

    2008-03-01

    Full Text Available Abstract Background DNA double-strand breaks (DSBs are induced by exogenous insults such as ionizing radiation and chemical exposure, and they can also arise as a consequence of stalled or collapsed DNA replication forks. Failure to repair DSBs can lead to genomic instability or cell death and cancer in higher eukaryotes. The Schizosaccharomyces pombe fbh1 gene encodes an F-box DNA helicase previously described to play a role in the Rhp51 (an orthologue of S. cerevisiae RAD51-dependent recombinational repair of DSBs. Fbh1 fused to GFP localizes to discrete nuclear foci following DNA damage. Results To determine the functional roles of the highly conserved F-box and helicase domains, we have characterized fbh1 mutants carrying specific mutations in these domains. We show that the F-box mutation fbh1-fb disturbs the nuclear localization of Fbh1, conferring an fbh1 null-like phenotype. Moreover, nuclear foci do not form in fbh1-fb cells with DNA damage even if Fbh1-fb is targeted to the nucleus by fusion to a nuclear localization signal sequence. In contrast, the helicase mutation fbh1-hl causes the accumulation of Fbh1 foci irrespective of the presence of DNA damage and confers damage sensitivity greater than that conferred by the null allele. Additional mutation of the F-box alleviates the hypermorphic phenotype of the fbh1-hl mutant. Conclusion These results suggest that the F-box and DNA helicase domains play indispensable but distinct roles in Fbh1 function. Assembly of the SCFFbh1 complex is required for both the nuclear localization and DNA damage-induced focus formation of Fbh1 and is therefore prerequisite for the Fbh1 recombination function.

  18. The role of passive muscle stiffness in symptoms of exercise-induced muscle damage.

    Science.gov (United States)

    McHugh, M P; Connolly, D A; Eston, R G; Kremenic, I J; Nicholas, S J; Gleim, G W

    1999-01-01

    We examined whether passive stiffness of an eccentrically exercising muscle group affects the subsequent symptoms of muscle damage. Passive hamstring muscle stiffness was measured during an instrumented straight-leg-raise stretch in 20 subjects (11 men and 9 women) who were subsequently classified as "stiff" (N = 7), "normal" (N = 6), or "compliant" (N = 7). Passive stiffness was 78% higher in the stiff subjects (36.2 +/- 3.3 N.m.rad(-1)) compared with the compliant subjects (20.3 +/- 1.8 N.m.rad(-1)). Subjects then performed six sets of 10 isokinetic (2.6 rad.s(-1)) submaximal (60% maximal voluntary contraction) eccentric actions of the hamstring muscle group. Symptoms of muscle damage were documented by changes in isometric hamstring muscle strength, pain, muscle tenderness, and creatine kinase activity on the following 3 days. Strength loss, pain, muscle tenderness, and creatine kinase activity were significantly greater in the stiff compared with the compliant subjects on the days after eccentric exercise. Greater symptoms of muscle damage in subjects with stiffer hamstring muscles are consistent with the sarcomere strain theory of muscle damage. The present study provides experimental evidence of an association between flexibility and muscle injury. Muscle stiffness and its clinical correlate, static flexibility, are risk factors for more severe symptoms of muscle damage after eccentric exercise.

  19. Apoptotic phosphorylation of histone H3 on Ser-10 by protein kinase Cδ.

    Directory of Open Access Journals (Sweden)

    Choon-Ho Park

    Full Text Available Phosphorylation of histone H3 on Ser-10 is regarded as an epigenetic mitotic marker and is tightly correlated with chromosome condensation during both mitosis and meiosis. However, it was also reported that histone H3 Ser-10 phosphorylation occurs when cells are exposed to various death stimuli, suggesting a potential role in the regulation of apoptosis. Here we report that histone H3 Ser-10 phosphorylation is mediated by the pro-apoptotic kinase protein kinase C (PKC δ during apoptosis. We observed that PKCδ robustly phosphorylates histone H3 on Ser-10 both in vitro and in vivo. Ectopic expression of catalytically active PKCδ efficiently induces condensed chromatin structure in the nucleus. We also discovered that activation of PKCδ is required for histone H3 Ser-10 phosphorylation after treatment with DNA damaging agents during apoptosis. Collectively, these findings suggest that PKCδ is the kinase responsible for histone H3 Ser-10 phosphoryation during apoptosis and thus contributes to chromatin condensation together with other apoptosis-related histone modifications. As a result, histone H3 Ser-10 phosphorylation can be designated a new 'apoptotic histone code' mediated by PKCδ.

  20. Hederagenin Supplementation Alleviates the Pro-Inflammatory and Apoptotic Response to Alcohol in Rats

    Directory of Open Access Journals (Sweden)

    Gyeong-Ji Kim

    2017-01-01

    Full Text Available In this study, we determined the effects of hederagenin isolated from Akebia quinata fruit on alcohol-induced hepatotoxicity in rats. Specifically, we investigated the hepatoprotective, anti-inflammatory, and anti-apoptotic effects of hederagenin, as well as the role of AKT and mitogen-activated protein kinase (MAPK signaling pathways in ethanol-induced liver injury. Experimental animals were randomly divided into three groups: normal (sham, 25% ethanol, and 25% ethanol + hederagenin (50 mg/kg/day. Each group was orally administered the respective treatments once per day for 21 days. Acetaldehyde dehydrogenase-2 mRNA expression was higher and alcohol dehydrogenase mRNA expression was lower in the ethanol + hederagenin group than those in the ethanol group. Pro-inflammatory cytokines, including TNF-α, IL-6, and cyclooxygenase-2, significantly increased in the ethanol group, but these increases were attenuated by hederagenin. Moreover, Western blot analysis showed increased expression of the apoptosis-associated protein, Bcl-2, and decreased expression of Bax and p53 after treatment with hederagenin. Hederagenin treatment attenuated ethanol-induced increases in activated p38 MAPK and increased the levels of phosphorylated AKT and ERK. Hederagenin alleviated ethanol-induced liver damage through anti-inflammatory and anti-apoptotic activities. These results suggest that hederagenin is a potential candidate for preventing alcoholic liver injury.

  1. Abnormalities in Alternative Splicing of Apoptotic Genes and Cardiovascular Diseases

    Directory of Open Access Journals (Sweden)

    Zodwa Dlamini

    2015-11-01

    Full Text Available Apoptosis is required for normal heart development in the embryo, but has also been shown to be an important factor in the occurrence of heart disease. Alternative splicing of apoptotic genes is currently emerging as a diagnostic and therapeutic target for heart disease. This review addresses the involvement of abnormalities in alternative splicing of apoptotic genes in cardiac disorders including cardiomyopathy, myocardial ischemia and heart failure. Many pro-apoptotic members of the Bcl-2 family have alternatively spliced isoforms that lack important active domains. These isoforms can play a negative regulatory role by binding to and inhibiting the pro-apoptotic forms. Alternative splicing is observed to be increased in various cardiovascular diseases with the level of alternate transcripts increasing elevated in diseased hearts compared to healthy subjects. In many cases these isoforms appear to be the underlying cause of the disease, while in others they may be induced in response to cardiovascular pathologies. Regardless of this, the detection of alternate splicing events in the heart can serve as useful diagnostic or prognostic tools, while those splicing events that seem to play a causative role in cardiovascular disease make attractive future drug targets.

  2. The role of intracellular redox imbalance in nanomaterial induced cellular damage and genotoxicity

    DEFF Research Database (Denmark)

    Kermanizadeh, Ali; Chauché, Caroline; Brown, David M;

    2015-01-01

    as one of the main contributors to nanomaterial (NM) induced adverse effects. One of the most important and widely investigated of these effects is genotoxicity. In general, systems that defend an organism against oxidative damage to DNA are very complex and include prevention of reactive oxygen species...

  3. Inference in Right Hemisphere Damaged Individuals' Comprehension: The Role of Sustained Attention

    Science.gov (United States)

    Saldert, Charlotta; Ahlsen, Elisabeth

    2007-01-01

    The ability to make inferences for the purposes of comprehension is considered an important factor in pragmatic ability. In this experimental group study with stroke patients, the ability to make inferences and its associations with sustained attention and verbal working memory were explored. A group of 14 left-hemisphere-damaged individuals had…

  4. Mechanisms of cytolysin-induced cell damage -- a role for auto- and paracrine signalling

    DEFF Research Database (Denmark)

    Skals, Marianne Gerberg; Prætorius, Helle

    2013-01-01

    Cytolysins inflict cell damage by forming pores in the plasma membrane. The Na(+) conductivity of these pores results in an ion influx that exceeds the capacity of the Na(+) /K(+) -pump to extrude Na(+) . This net load of intracellular osmolytes results in swelling and eventual lysis of the attac...

  5. Role of c-Abl in the DNA damage stress response

    Institute of Scientific and Technical Information of China (English)

    Yosef SHAUL; Merav BEN-YEHOYADA

    2005-01-01

    c-Abl has been implicated in many cellular processes including differentiation, division, adhesion, death, and stress response. c-Abl is a latent tyrosine kinase that becomes activated in response to numerous extra- and intra-cellular stimuli. Here we briefly review the current knowledge about c-Abl involvement in the DNA-damage stress response and its implication on cell physiology.

  6. Collaborative damage mapping for emergency response : the role of Cognitive Systems Engineering

    NARCIS (Netherlands)

    Kerle, N.; Hoffman, R.R.

    2013-01-01

    Remote sensing is increasingly used to assess disaster damage, traditionally by professional image analysts. A recent alternative is crowdsourcing by volunteers experienced in remote sensing, using internet-based mapping portals. We identify a range of problems in current approaches, including how v

  7. Effect of methamphetamine on the microglial damage: role of potassium channel Kv1.3.

    Directory of Open Access Journals (Sweden)

    Jun Wang

    Full Text Available Methamphetamine (Meth abusing represents a major public health problem worldwide. Meth has long been known to induce neurotoxicity. However, the mechanism is still remained poorly understood. Growing evidences indicated that the voltage-gated potassium channels (Kv were participated in neuronal damage and microglia function. With the whole cell patch clamp, we found that Meth significantly increased the outward K⁺ currents, therefore, we explored whether Kv1.3, one of the major K⁺ channels expressed in microglia, was involved in Meth-induced microglia damage. Our study showed that Meth significantly increased the cell viability in a dose dependent manner, while the Kv blocker, tetraethylamine (TEA, 4-Aminopyridine (4-AP and Kv1.3 specific antagonist margatoxin (MgTx, prevented against the damage mediated by Meth. Interestingly, treatment of cells with Meth resulted in increasing expression of Kv1.3 rather than Kv1.5, at both mRNA and protein level, which is partially blocked by MgTx. Furthermore, Meth also stimulated a significant increased expression of IL-6 and TNF-α at protein level, which was significantly inhibited by MgTx. Taken together, these results demonstrated that Kv1.3 was involved in Meth-mediated microglial damage, providing the potential target for the development of therapeutic strategies for Meth abuse.

  8. The role of DNA damage and repair in decitabine-mediated apoptosis in multiple myeloma.

    Science.gov (United States)

    Maes, Ken; De Smedt, Eva; Lemaire, Miguel; De Raeve, Hendrik; Menu, Eline; Van Valckenborgh, Els; McClue, Steve; Vanderkerken, Karin; De Bruyne, Elke

    2014-05-30

    DNA methyltransferase inhibitors (DNMTi) and histone deacetylase inhibitors (HDACi) are under investigation for the treatment of cancer, including the plasma cell malignancy multiple myeloma (MM). Evidence exists that DNA damage and repair contribute to the cytotoxicity mediated by the DNMTi decitabine. Here, we investigated the DNA damage response (DDR) induced by decitabine in MM using 4 human MM cell lines and the murine 5T33MM model. In addition, we explored how the HDACi JNJ-26481585 affects this DDR. Decitabine induced DNA damage (gamma-H2AX foci formation), followed by a G0/G1- or G2/M-phase arrest and caspase-mediated apoptosis. JNJ-26481585 enhanced the anti-MM effect of decitabine both in vitro and in vivo. As JNJ-26481585 did not enhance decitabine-mediated gamma-H2AX foci formation, we investigated the DNA repair response towards decitabine and/or JNJ-26481585. Decitabine augmented RAD51 foci formation (marker for homologous recombination (HR)) and/or 53BP1 foci formation (marker for non-homologous end joining (NHEJ)). Interestingly, JNJ-26481585 negatively affected basal or decitabine-induced RAD51 foci formation. Finally, B02 (RAD51 inhibitor) enhanced decitabine-mediated apoptosis. Together, we report that decitabine-induced DNA damage stimulates HR and/or NHEJ. JNJ-26481585 negatively affects RAD51 foci formation, thereby providing an additional explanation for the combinatory effect between decitabine and JNJ-26481585.

  9. Methotrexate-induced nitrosative stress may play a critical role in small intestinal damage in the rat

    Energy Technology Data Exchange (ETDEWEB)

    Kolli, Viswa Kalyan; Abraham, Premila [Christian Medical College, Department of Biochemistry, Vellore, Tamil Nadu (India); Rabi, Suganthy [Christian Medical College, Department of Anatomy, Vellore, Tamil Nadu (India)

    2008-10-15

    Methotrexate (MTX), a structural analogue of folic acid, is widely used as a chemotherapeutic agent for leukemia and other malignancies. One of the major toxic effects of MTX is intestinal injury and enterocolitis.The mechanism of gastrointestinal toxicity of methotrexate has not been investigated completely. Therefore cancer chemotherapy has to be accompanied by symptomatic therapy such as antibiotics and anti-diarrheal drugs. It is important to investigate the mechanism by which methotrexate induces intestinal damage in order to perform cancer chemotherapy effectively by preventing the side effects. This study aimed at investigating whether nitrosative stress plays a role in methotrexate induced small intestinal damage using a rat model. Adult male rats were administered methotrexate at the dose of 7 mg/kg body weight intraperitoneally for 3 consecutive days and sacrificed 12 or 24 h after the final dose of methotrexate. Vehicle treated rats served as control. The intestinal tissue was used for light microscopic studies and markers of nitrosative stress including tissue nitrite level and nitrotyrosine. Myeloperoxidase (MPO) activity, a marker of neutrophil infiltration was also measured in intestinal homogenates. The villi were damaged at 12 h and the damage progressed and became severe at 24 h after the final dose of MTX. Biochemically, tissue nitrate was elevated fivefold at 12 h and fourfold at 24 h after the final dose of MTX as compared with control. Nitrotyrosine, measured immunohistochemically was detected in all the parts of the small intestine. Duodenum stained the most for nitrotyrosine, followed by ileum and then jejunum. The staining for nitrotyrosine was more intense at 24 h as compared with 12 h after the final dose of methotrexate. There was marked neutrophil infiltration as evidenced by increase in MPO activity in the small intestines. In conclusion, the results of the present study reveal that nitrosative stress may play a critical role in

  10. The role of Candida albicans homologous recombination factors Rad54 and Rdh54 in DNA damage sensitivity

    Directory of Open Access Journals (Sweden)

    White Theodore C

    2011-09-01

    Full Text Available Abstract Background The fungal pathogen Candida albicans is frequently seen in immune suppressed patients, and resistance to one of the most widely used antifungals, fluconazole (FLC, can evolve rapidly. In recent years it has become clear that plasticity of the Candida albicans genome contributes to drug resistance through loss of heterozygosity (LOH at resistance genes and gross chromosomal rearrangements that amplify gene copy number of resistance associated genes. This study addresses the role of the homologous recombination factors Rad54 and Rdh54 in cell growth, DNA damage and FLC resistance in Candida albicans. Results The data presented here support a role for homologous recombination in cell growth and DNA damage sensitivity, as Candida albicans rad54Δ/rad54Δ mutants were hypersensitive to MMS and menadione, and had an aberrant cell and nuclear morphology. The Candida albicans rad54Δ/rad54Δ mutant was defective in invasion of Spider agar, presumably due to the altered cellular morphology. In contrast, mutation of the related gene RDH54 did not contribute significantly to DNA damage resistance and cell growth, and deletion of either Candida albicans RAD54 or Candida albicans RDH54 did not alter FLC susceptibility. Conclusions Together, these results support a role for homologous recombination in genome stability under nondamaging conditions. The nuclear morphology defects in the rad54Δ/rad54Δ mutants show that Rad54 performs an essential role during mitotic growth and that in its absence, cells arrest in G2. The viability of the single mutant rad54Δ/rad54Δ and the inability to construct the double mutant rad54Δ/rad54Δ rdh54Δ/rdh54Δ suggests that Rdh54 can partially compensate for Rad54 during mitotic growth.

  11. Oxidative stress and nerve damage: Role in chemotherapy induced peripheral neuropathy

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    Aparna Areti

    2014-01-01

    Full Text Available Peripheral neuropathy is a severe dose limiting toxicity associated with cancer chemotherapy. Ever since it was identified, the clear pathological mechanisms underlying chemotherapy induced peripheral neuropathy (CIPN remain sparse and considerable involvement of oxidative stress and neuroinflammation has been realized recently. Despite the empirical use of antioxidants in the therapy of CIPN, the oxidative stress mediated neuronal damage in peripheral neuropathy is still debatable. The current review focuses on nerve damage due to oxidative stress and mitochondrial dysfunction as key pathogenic mechanisms involved in CIPN. Oxidative stress as a central mediator of apoptosis, neuroinflammation, metabolic disturbances and bioenergetic failure in neurons has been highlighted in this review along with a summary of research on dietary antioxidants and other nutraceuticals which have undergone prospective controlled clinical trials in patients undergoing chemotherapy.

  12. Sex chromosome inactivation in germ cells: emerging roles of DNA damage response pathways.

    Science.gov (United States)

    Ichijima, Yosuke; Sin, Ho-Su; Namekawa, Satoshi H

    2012-08-01

    Sex chromosome inactivation in male germ cells is a paradigm of epigenetic programming during sexual reproduction. Recent progress has revealed the underlying mechanisms of sex chromosome inactivation in male meiosis. The trigger of chromosome-wide silencing is activation of the DNA damage response (DDR) pathway, which is centered on the mediator of DNA damage checkpoint 1 (MDC1), a binding partner of phosphorylated histone H2AX (γH2AX). This DDR pathway shares features with the somatic DDR pathway recognizing DNA replication stress in the S phase. Additionally, it is likely to be distinct from the DDR pathway that recognizes meiosis-specific double-strand breaks. This review article extensively discusses the underlying mechanism of sex chromosome inactivation.

  13. Local governments' roles of the compensation for damage by the Tokai JCO criticality accident

    Energy Technology Data Exchange (ETDEWEB)

    Tanabe, Tomoyuki [Central Research Inst. of Electric Power Industry, Tokyo (Japan). Socio-Economic Research Center

    2003-03-01

    The Tokai JCO criticality accident on September 30, 1999 was the first case to which The Law on Compensation for Nuclear Damage was applied. Although the Law on Compensation for Nuclear Damage formulates the outline of the institutional framework for nuclear third party liability together with operator's insurance scheme, details of actual compensation procedure are not specified. By this reason, the compensation procedure in the Tokai accident had been executed without a concrete legal specification and a precedent. In spite of this situation, the compensation procedure with the accident led to an unexpectedly successful result. We observe the several reasons why the compensation procedure was implemented successfully despite the lack of concrete legal specification and a precedent. One of the reasons is that the local governments, Tokai Village and Ibaraki Prefecture, immediately took the leadership in implementing a temporary regime of compensation procedure without wasting time for waiting national government's directives. Upon practicing this compensation procedure, the local governments implemented the following steps. (1) Initial estimation of the amount and scope of damage. (2) Providing the criteria and heads of damage subject to compensation. (3) Unitary compensation procedure at the local levels. (4) Distribution of emergency payments for the victims. (5) Facilitating compensatory negotiation between the victims and JCO as arbitrator. However, some concerns are also pointed out about the fact that the local government directed the whole procedure without sufficient adjustment with the national government for compensation policy. Among all, in the compensation led by the local governments, it was difficult to guarantee fairness of compensation because victims who are influential on the local government such as industrial associations would have unfairly strong negotiation power in the compensatory negotiation, while the operator being

  14. Oxidative damage in muscular dystrophy correlates with the severity of the pathology: role of glutathione metabolism.

    Science.gov (United States)

    Renjini, R; Gayathri, N; Nalini, A; Srinivas Bharath, M M

    2012-04-01

    Muscular dystrophies (MDs) such as Duchenne muscular dystrophy (DMD), sarcoglycanopathy (Sgpy) and dysferlinopathy (Dysfy) are recessive genetic neuromuscular diseases that display muscle degeneration. Although these MDs have comparable endpoints of muscle pathology, the onset, severity and the course of these diseases are diverse. Different mechanisms downstream of genetic mutations might underlie the disparity in these pathologies. We surmised that oxidative damage and altered antioxidant function might contribute to these differences. The oxidant and antioxidant markers in the muscle biopsies from patients with DMD (n = 15), Sgpy (n = 15) and Dysfy (n = 15) were compared to controls (n = 10). Protein oxidation and lipid peroxidation was evident in all MDs and correlated with the severity of pathology, with DMD, the most severe dystrophic condition showing maximum damage, followed by Sgpy and Dysfy. Oxidative damage in DMD and Sgpy was attributed to the depletion of glutathione (GSH) and lowered antioxidant activities while loss of GSH peroxidase and GSH-S-transferase activities was observed in Dysfy. Lower GSH level in DMD was due to lowered activity of gamma-glutamyl cysteine ligase, the rate limiting enzyme in GSH synthesis. Similar analysis in cardiotoxin (CTX) mouse model of MD showed that the dystrophic muscle pathology correlated with GSH depletion and lipid peroxidation. Depletion of GSH prior to CTX exposure in C2C12 myoblasts exacerbated oxidative damage and myotoxicity. We deduce that the pro and anti-oxidant mechanisms could be correlated to the severity of MD and might influence the dystrophic pathology to a different extent in various MDs. On a therapeutic note, this could help in evolving novel therapies that offer myoprotection in MD.

  15. MutS homologue hMSH5: role in cisplatin-induced DNA damage response

    OpenAIRE

    Tompkins Joshua D; Wu Xiling; Her Chengtao

    2012-01-01

    Abstract Background Cisplatin (cis-diamminedichloroplatinum (II), CDDP) and its analogues constitute an important class of anticancer drugs in the treatment of various malignancies; however, its effectiveness is frequently affected by mutations in genes involved in the repair and signaling of cisplatin-induced DNA damage. These observations necessitate a need for a better understanding of the molecular events governing cellular sensitivity to cisplatin. Results Here, we show that hMSH5 mediat...

  16. How to avoid reputation damage in financial restatement? The role of investor relations management

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In order to examine the effects of avoiding reputation damage by investor relations management under certain corporate governance structures and mechanisms, samples of 1120 listed companies are used to research the influence on financial restatements by corporate governance. Then the moderating effects of investor relations management on financial restatements are analyzed. The result is that the more dispersed the equity, the higher the probability of financial restatements will be (This includes the gover...

  17. Role of swi7H4 mutant allele of DNA polymerase α in the DNA damage checkpoint response.

    Science.gov (United States)

    Khan, Saman; Ahmed, Shakil

    2015-01-01

    Besides being a mediator of initiation of DNA replication, DNA polymerase α plays a key role in chromosome maintenance. Swi7H4, a novel temperature sensitive mutant of DNA polymerase α was shown to be defective in transcriptional silencing at the mating type centromere and telomere loci. It is also required for the establishment of chromatin state that can recruit the components of the heterochromatin machinery at these regions. Recently the role of DNA polymerase α in the S-phase alkylation damage response in S. pombe has also been studied. Here we investigate whether defects generated by swi7H4, a mutant allele of DNA polymerase α can activate a checkpoint response. We show that swi7H4 exhibit conditional synthetic lethality with chk1 null mutant and the double mutant of swi7H4 with chk1 deletion aggravate the chromosome segregation defects. More importantly swi7H4 mutant cells delay the mitotic progression at non permissive temperature that is mediated by checkpoint protein kinase Chk1. In addition we show that, in the swi7H4 mutant background, cells accumulate DNA damage at non permissive temperature activating the checkpoint kinase protein Chk1. Further, we observed synthetic lethality between swi7H4 and a number of genes involved in DNA repair pathway at semi permissive temperature. We summarize that defects in swi7H4 mutant results in DNA damage that delay mitosis in a Chk1 dependent manner that also require the damage repair pathway for proper recovery.

  18. Role of swi7H4 mutant allele of DNA polymerase α in the DNA damage checkpoint response.

    Directory of Open Access Journals (Sweden)

    Saman Khan

    Full Text Available Besides being a mediator of initiation of DNA replication, DNA polymerase α plays a key role in chromosome maintenance. Swi7H4, a novel temperature sensitive mutant of DNA polymerase α was shown to be defective in transcriptional silencing at the mating type centromere and telomere loci. It is also required for the establishment of chromatin state that can recruit the components of the heterochromatin machinery at these regions. Recently the role of DNA polymerase α in the S-phase alkylation damage response in S. pombe has also been studied. Here we investigate whether defects generated by swi7H4, a mutant allele of DNA polymerase α can activate a checkpoint response. We show that swi7H4 exhibit conditional synthetic lethality with chk1 null mutant and the double mutant of swi7H4 with chk1 deletion aggravate the chromosome segregation defects. More importantly swi7H4 mutant cells delay the mitotic progression at non permissive temperature that is mediated by checkpoint protein kinase Chk1. In addition we show that, in the swi7H4 mutant background, cells accumulate DNA damage at non permissive temperature activating the checkpoint kinase protein Chk1. Further, we observed synthetic lethality between swi7H4 and a number of genes involved in DNA repair pathway at semi permissive temperature. We summarize that defects in swi7H4 mutant results in DNA damage that delay mitosis in a Chk1 dependent manner that also require the damage repair pathway for proper recovery.

  19. Apoptotic engulfment pathway and schizophrenia.

    Directory of Open Access Journals (Sweden)

    Xiangning Chen

    Full Text Available BACKGROUND: Apoptosis has been speculated to be involved in schizophrenia. In a previously study, we reported the association of the MEGF10 gene with the disease. In this study, we followed the apoptotic engulfment pathway involving the MEGF10, GULP1, ABCA1 and ABCA7 genes and tested their association with the disease. METHODOLOGY/PRINCIPAL FINDINGS: Ten, eleven and five SNPs were genotyped in the GULP1, ABCA1 and ABCA7 genes respectively for the ISHDSF and ICCSS samples. In all 3 genes, we observed nominally significant associations. Rs2004888 at GULP1 was significant in both ISHDSF and ICCSS samples (p = 0.0083 and 0.0437 respectively. We sought replication in independent samples for this marker and found highly significant association (p = 0.0003 in 3 Caucasian replication samples. But it was not significant in the 2 Chinese replication samples. In addition, we found a significant 2-marker (rs2242436 * rs3858075 interaction between the ABCA1 and ABCA7 genes in the ISHDSF sample (p = 0.0022 and a 3-marker interaction (rs246896 * rs4522565 * rs3858075 amongst the MEGF10, GULP1 and ABCA1 genes in the ICCSS sample (p = 0.0120. Rs3858075 in the ABCA1 gene was involved in both 2- and 3-marker interactions in the two samples. CONCLUSIONS/SIGNIFICANCE: From these data, we concluded that the GULP1 gene and the apoptotic engulfment pathway are involved in schizophrenia in subjects of European ancestry and multiple genes in the pathway may interactively increase the risks to the disease.

  20. Apoptotic engulfment pathway and schizophrenia.

    LENUS (Irish Health Repository)

    Chen, Xiangning

    2009-01-01

    BACKGROUND: Apoptosis has been speculated to be involved in schizophrenia. In a previously study, we reported the association of the MEGF10 gene with the disease. In this study, we followed the apoptotic engulfment pathway involving the MEGF10, GULP1, ABCA1 and ABCA7 genes and tested their association with the disease. METHODOLOGY\\/PRINCIPAL FINDINGS: Ten, eleven and five SNPs were genotyped in the GULP1, ABCA1 and ABCA7 genes respectively for the ISHDSF and ICCSS samples. In all 3 genes, we observed nominally significant associations. Rs2004888 at GULP1 was significant in both ISHDSF and ICCSS samples (p = 0.0083 and 0.0437 respectively). We sought replication in independent samples for this marker and found highly significant association (p = 0.0003) in 3 Caucasian replication samples. But it was not significant in the 2 Chinese replication samples. In addition, we found a significant 2-marker (rs2242436 * rs3858075) interaction between the ABCA1 and ABCA7 genes in the ISHDSF sample (p = 0.0022) and a 3-marker interaction (rs246896 * rs4522565 * rs3858075) amongst the MEGF10, GULP1 and ABCA1 genes in the ICCSS sample (p = 0.0120). Rs3858075 in the ABCA1 gene was involved in both 2- and 3-marker interactions in the two samples. CONCLUSIONS\\/SIGNIFICANCE: From these data, we concluded that the GULP1 gene and the apoptotic engulfment pathway are involved in schizophrenia in subjects of European ancestry and multiple genes in the pathway may interactively increase the risks to the disease.

  1. The role of poly(ADP-ribose) in the DNA damage signaling network.

    Science.gov (United States)

    Malanga, Maria; Althaus, Felix R

    2005-06-01

    DNA damage signaling is crucial for the maintenance of genome integrity. In higher eukaryotes a NAD+-dependent signal transduction mechanism has evolved to protect cells against the genome destabilizing effects of DNA strand breaks. The mechanism involves 2 nuclear enzymes that sense DNA strand breaks, poly(ADP-ribose) polymerase-1 and -2 (PARP-1 and PARP-2). When activated by DNA breaks, these PARPs use NAD+ to catalyze their automodification with negatively charged, long and branched ADP-ribose polymers. Through recruitment of specific proteins at the site of damage and regulation of their activities, these polymers may either directly participate in the repair process or coordinate repair through chromatin unfolding, cell cycle progression, and cell survival-cell death pathways. A number of proteins, including histones, DNA topoisomerases, DNA methyltransferase-1 as well as DNA damage repair and checkpoint proteins (p23, p21, DNA-PK, NF-kB, XRCC1, and others) can be targeted in this manner; the interaction involves a specific poly(ADP-ribose)-binding sequence motif of 20-26 amino acids in the target domains.

  2. An experimental study on photothermal damage to tissue: the role of irradiance and wavelength

    Science.gov (United States)

    Yildiz, F.; Gulsoy, M.; Cilesiz, I.

    2016-09-01

    Laser exposure time and irradiance are crucial parameters governing the process of thermal damage. The goal of our in vitro study was to study and determine optimal parameters for the onset of coagulation and carbonization at three different wavelengths (980, 1070 and 1940 nm). We also compared photothermal effects at these three wavelengths by varying laser exposure time and irradiance. Fresh bovine liver specimens were used for experimentation. The onset of thermal damage at different irradiances and for different exposure time was studied macroscopically and histologically. Photothermal damage or lesion volume generally decreased with irradiance and increasing exposure time. We observed an exponential and linear relationship between irradiance and exposure time for specific thermal endpoints. These specific endpoints were the onset of (i) coagulation, and (ii) carbonization. The time interval or difference between these specific endpoints termed as Δt (t carbonization  -  t coagulation) (s) was also determined. This relation between irradiance and exposure time will make possible the pre-estimation of thermal tissue lesion volume before operation, and photothermal therapy may thus be performed with minimum side effects on liver tissue.

  3. Protective role for type 4 metabotropic glutamate receptors against ischemic brain damage.

    Science.gov (United States)

    Moyanova, Slavianka G; Mastroiacovo, Federica; Kortenska, Lidia V; Mitreva, Rumiana G; Fardone, Erminia; Santolini, Ines; Sobrado, Mónica; Battaglia, Giuseppe; Bruno, Valeria; Nicoletti, Ferdinando; Ngomba, Richard T

    2011-04-01

    We examined the influence of type 4 metabotropic glutamate (mGlu4) receptors on ischemic brain damage using the permanent middle cerebral artery occlusion (MCAO) model in mice and the endothelin-1 (Et-1) model of transient focal ischemia in rats. Mice lacking mGlu4 receptors showed a 25% to 30% increase in infarct volume after MCAO as compared with wild-type littermates. In normal mice, systemic injection of the selective mGlu4 receptor enhancer, N-phenyl-7-(hydroxyimino)cyclopropa[b]chromen-1a-caboxamide (PHCCC; 10  mg/kg, subcutaneous, administered once 30  minutes before MCAO), reduced the extent of ischemic brain damage by 35% to 45%. The drug was inactive in mGlu4 receptor knockout mice. In the Et-1 model, PHCCC administered only once 20  minutes after ischemia reduced the infarct volume to a larger extent in the caudate/putamen than in the cerebral cortex. Ischemic rats treated with PHCCC showed a faster recovery of neuronal function, as shown by electrocorticographic recording and by a battery of specific tests, which assess sensorimotor deficits. These data indicate that activation of mGlu4 receptors limit the development of brain damage after permanent or transient focal ischemia. These findings are promising because selective mGlu4 receptor enhancers are under clinical development for the treatment of Parkinson's disease and other central nervous system disorders.

  4. Direct interaction of the molecular scaffolds POSH and JIP is required for apoptotic activation of JNKs.

    Science.gov (United States)

    Kukekov, Nickolay V; Xu, Zhiheng; Greene, Lloyd A

    2006-06-02

    A sequential pathway (the JNK pathway) that includes activation of Rac1/Cdc42, mixed lineage kinases, MAP kinase kinases 4 and 7, and JNKs plays a required role in many paradigms of apoptotic cell death. However, the means by which this pathway is assembled and directed toward apoptotic death has been unclear. Here, we report that propagation of the apoptotic JNK pathway requires the cooperative interaction of two molecular scaffolds, POSH and JIPs. POSH (plenty of SH3s) is a multidomain GTP-Rac1-interacting protein that binds and promotes activation of mixed lineage kinases. JIPs are reported to bind MAP kinase kinases 4/7 and JNKs. We find that POSH and JIPs directly associate with one another to form a multiprotein complex, PJAC (POSH-JIP apoptotic complex), that includes all of the known kinase components of the pathway. Our observations indicate that this complex is required for JNK activation and cell death in response to apoptotic stimuli.

  5. Phototherapy-treated apoptotic tumor cells induce pro-inflammatory cytokines production in macrophage

    Science.gov (United States)

    Lu, Cuixia; Wei, Yanchun; Xing, Da

    2014-09-01

    Our previous studies have demonstrated that as a mitochondria-targeting cancer phototherapy, high fluence low-power laser irradiation (HF-LPLI) induces mitochondrial superoxide anion burst, resulting in oxidative damage to tumor cells. In this study, we further explored the immunological effects of HF-LPLI-induced apoptotic tumor cells. When macrophages were co-incubated with apoptotic cells induced by HF-LPLI, we observed the increased levels of TNF-α secretion and NO production in macrophages. Further experiments showed that NF-κB was activated in macrophages after co-incubation with HF-LPLI-induced apoptotic cells, and inhibition of NF-κB activity by pyrrolidinedithiocarbamic acid (PDTC) reduced the elevated levels of TNF-α secretion and NO production. These data indicate that HF-LPLI-induced apoptotic tumor cells induce the secretion of pro-inflammatory cytokines in macrophages, which may be helpful for better understanding the biological effects of cancer phototherapy.

  6. DDX3 regulates DNA damage-induced apoptosis and p53 stabilization.

    Science.gov (United States)

    Sun, Mianen; Zhou, Tong; Jonasch, Eric; Jope, Richard S

    2013-06-01

    The DEAD box protein family member DDX3 was previously identified as an inhibitor of death receptor-mediated extrinsic apoptotic signaling. However, there had been no studies of the role of DDX3 in regulating the other major type of apoptosis, intrinsic apoptotic signaling, which was examined here. Intrinsic apoptosis was induced in MCF-7 cells by treatment with staurosporine, a general kinase inhibitor, thapsigargin, which induces endoplasmic reticulum (ER) stress, and camptothecin, which causes DNA damage. Each of these treatments caused time-dependent activation of caspase-7, the predominant executioner caspase in these cells. Depletion of DDX3 using shRNA did not alter apoptotic responses to staurosporine or thapsigargin. However, caspase-7 activation induced by camptothecin was regulated by DDX3 in a manner dependent on the functional status of p53. Depletion of DDX3 abrogated camptothecin-induced caspase-7 activation in MCF-7 cells expressing functional wild-type p53, but oppositely potentiated camptothecin-mediated caspase activation in cells expressing mutant or non-functional p53, which was accompanied by increased activation of the extrinsic apoptotic signaling initiator caspase-8. In MCF-7 cells, depletion of DDX3 reduced by more than 50% camptothecin-induced p53 accumulation, and this effect was blocked by inhibition of the proteasome with MG132, indicating that DDX3 regulates p53 not at expression level but rather its stabilization after DNA damage. Co-immunoprecipitation experiments demonstrated that DDX3 associates with p53, and overexpression of DDX3 was sufficient to double the accumulation of p53 in the nucleus after DNA damage. Thus, DDX3 associates with p53, increases p53 accumulation, and positively regulates camptothecin-induced apoptotic signaling in cells expressing functional wild-type p53, whereas in cells expressing mutant or non-functional p53 DDX3 inhibits activation of the extrinsic apoptotic pathway to reduce caspase activation. These

  7. Role of candesartan against cerebral ischemia and oxidative damage in normotensive rats

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Objective Angiotensin Ⅱ(Ang Ⅱ)contributes to modulating blood pressure by stimulation of Ang Ⅱ AT1 receptors.We devised a rat transient middle cerebral artery occlusion(MCAO)model to assess whether oxidative damage is decreased after pretreatment with Angiotensin Ⅱ AT1 receptor blocker(ARB).Methods After 2 weeks pretreatment with ARB 0.5 and 1mg/kg,the male Wister rats were subjected to 2h middle cerebral artery occlusion(MCAO).At 24h,the lumen diameter of middle cerebral artery,the plasma level of 8-hydrox...

  8. Potential role of Saudi red propolis in alleviating lung damage induced by methicillin resistant Staphylococcus aureus virulence in rats.

    Science.gov (United States)

    Saddiq, Amna Ali; Mohamed, Azza Mostafa

    2016-07-01

    The aim of this study was to explore the protective impact of aqueous extract of Saudi red propolis against rat lung damage induced by the pathogenic bacteria namely methicillin resistant Staphylococcus aureus (MRSA) ATCC 6538 strain. Infected rats were received a single intraperitoneal (i.p.) injection of bacterial suspension at a dose of 1 X 10(6) CFU / 100g body weight. Results showed that oral administration of an aqueous extract of propolis (50mg/100g body weight) daily for two weeks to infected rats simultaneously with bacterial infection, effectively ameliorated the alteration of oxidative stress biomarker, malondialdehyde (MDA), as well as the antioxidant markers, glutathione peroxidase (GPx) and superoxide dismutase (SOD), in lungs of infected rats compared with infected untreated ones. Also, the used propolis extract successfully modulated the alterations in proinflammatory mediators, tumor necrosis factor-α (TNF- α) and vascular endothelial growth factor (VEGF) in serum. In addition, the propolis extract successfully modulated the oxidative DNA damage and the apoptosis biomarker, caspase 3, in lungs of S aureus infected rats compared with infected untreated animals. The biochemical results were supported by histo-pathological observation of lung tissues. In conclusion, the beneficial prophylactic role of the aqueous extract of Saudi red propolis against lung damage induced by methicillin resistant S aureus may be related to the antioxidant, anti-inflammatory, immunomodulatory and antiapoptosis of its active constituents.

  9. Assessment of the Protective Role of Prenatal Zinc versus Insulin Supplementation on Fetal Cardiac Damage Induced by Maternal Diabetes in Rat Using Caspase-3 and KI67 Immunohistochemical Stains

    Directory of Open Access Journals (Sweden)

    Ahmed S. Shams

    2016-01-01

    Full Text Available Maternal diabetes mellitus (DM affects early organogenesis. Metabolic disorders of DM are associated with a depleted zinc status. This study evaluated the effect of maternal DM on cardiac development of rat fetuses and protective roles of prenatal zinc versus insulin supplementation. Pregnant rats were divided into 4 groups ((I control, (II STZ-induced DM, (III STZ-induced DM treated with Zn, and (IV STZ induced DM treated with insulin, all sacrificed on GD 20. Fetal heart weight of diabetic rats showed significant decrease compared to controls (P<0.05. H&E stained section of controls had normal appearance of the myocardium, compared to diabetics that showed myocardial disarray with characteristic degenerative changes. Sections of zinc treated group showed restored architecture of normal myofibrils with minimal degenerative changes, while those of insulin treated group show partial restoration of the normal architecture of cardiomyocytes with focal improvement of cardiac tissue. Caspase-3 immunostained slides showed positive cytoplasmic immunoreactivity in diabetic group. But KI67 immunostained slides revealed negative nuclear immunoreaction in diabetics. We observed that gestational diabetes was associated with increased risk of fetal myocardial damage that might be caused by increased apoptotic level. Treating diabetic pregnant subjects with zinc and insulin was associated with improvement in myocardial integrity.

  10. The role of chemokines in hypertension and consequent target organ damage.

    Science.gov (United States)

    Rudemiller, Nathan P; Crowley, Steven D

    2017-03-06

    Immune cells infiltrate the kidney, vasculature, and central nervous system during hypertension, consequently amplifying tissue damage and/or blood pressure elevation. Mononuclear cell motility depends partly on chemokines, which are small cytokines that guide cells through an increasing concentration gradient via ligation of their receptors. Tissue expression of several chemokines is elevated in clinical and experimental hypertension. Likewise, immune cells have enhanced chemokine receptor expression during hypertension, driving immune cell infiltration and inappropriate inflammation in cardiovascular control centers. T lymphocytes and monocytes/macrophages are pivotal mediators of hypertensive inflammation, and these cells migrate in response to several chemokines. As powerful drivers of diapedesis, the chemokines CCL2 and CCL5 have long been implicated in hypertension, but experimental data highlight divergent, context-specific effects of these chemokines on blood pressure and tissue injury. Several other chemokines, particularly those of the CXC family, contribute to blood pressure elevation and target organ damage. Given the significant interplay and chemotactic redundancy among chemokines during disease, future work must not only describe the actions of individual chemokines in hypertension, but also characterize how manipulating a single chemokine modulates the expression and/or function of other chemokines and their cognate receptors. This information will facilitate the design of precise chemotactic immunotherapies to limit cardiovascular and renal morbidity in hypertensive patients.

  11. Role of dietary antioxidants to protect against DNA damage in adult dogs.

    Science.gov (United States)

    Heaton, Paul R; Reed, Catrina F; Mann, Sarah J; Ransley, Raymond; Stevenson, Joy; Charlton, Chris J; Smith, Brigitte H E; Harper, E Jean; Rawlings, John M

    2002-06-01

    We studied the effects of feeding an antioxidant blend of vitamins, minerals and carotenoids to a mixed adult dog population (n = 40, mean 4.4 +/- 1.85 y) for a 16-wk period. Compared to the control group of dogs (n = 20), the antioxidant (AOX)-supplemented group of dogs (n = 20) demonstrated significant increases in plasma levels of vitamin E and taurine by 4 wk of supplementation (P total antioxidant activity (as measured by ferric-reducing antioxidant power assay) by 8 wk of supplementation (P neutralizing antibody levels at 2, 4 and 6 wk postvaccination (P < 0.05) and a tendency toward establishing a vaccine-specific antibody response quicker than did the control group of dogs. These findings in dogs suggest that antioxidant supplementation can achieve sustained increases in circulating levels of antioxidants that exert a protective effect by a decrease in DNA damage, leading to improved immunological performance. These findings also have implications in a wider context where free-radical damage has been associated with a variety of degenerative disorders and the aging process in general.

  12. Protective role of NecroX-5 against neomycin-induced hair cell damage in zebrafish.

    Science.gov (United States)

    Song, Jae-Jun; Chang, Jiwon; Choi, Jungim; Im, Gi Jung; Chae, Sung Won; Lee, Seung Hoon; Kwon, Soon-Young; Jung, Hak Hyun; Chung, Ah-Young; Park, Hae-Chul; Choi, June

    2014-02-01

    NecroX-5, one of the derivatives of NecroX series compounds, is a mitochondrial reactive oxygen species and reactive nitrogen species scavenger that inhibits cell death against various kinds of oxidative stresses. The objective of the present study was to evaluate the effects of NecroX-5 on neomycin-induced ototoxicity in transgenic zebrafish (Brn3C: EGFP). Five days post-fertilization, zebrafish larvae were exposed to 125 μM neomycin and one of the following NecroX-5 concentrations for 1 h: 10, 25, 50, and 75 μM. Hair cells within the neuromasts of the supraorbital (SO1 and SO2), otic (O1), and occipital (OC1) lateral lines were analyzed using fluorescence microscopy (n = 10). The terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay and 2-[4-(dimethylamino) styryl]-N-ethylpyridiniumiodide (DASPEI) assay were performed for evaluation of apoptosis and mitochondrial damage. Ultrastructural changes were evaluated using scanning electron microscopy. NecroX-5 decreased neomycin-induced hair cell loss in the neuromasts (NecroX-5 50 μM: 13.4 ± 2.0 cells, 125 μM neomycin only: 8.1 ± 1.2 cells; n = 10, P neomycin and 50 μM NecroX-5. NecroX-5 decreased apoptosis and mitochondrial damage. In conclusion, NecroX-5 attenuated neomycin-induced hair cell loss in zebrafish.

  13. Role of contraction-induced injury in the mechanisms of muscle damage in muscular dystrophy.

    Science.gov (United States)

    Lynch, Gordon S

    2004-08-01

    1. Duchenne muscular dystrophy (DMD) is a severe disease of skeletal muscle, characterized by an X-linked recessive inheritance and a lack of dystrophin in muscle fibres. It is associated with progressive and severe wasting and weakness of nearly all muscles and premature death by cardiorespiratory failure. 2. Studies investigating the susceptibility of dystrophic skeletal muscles to contraction-mediated damage, especially after lengthening actions where activated muscles are stretched forcibly, have concluded that dystrophin may confer protection to muscle fibres by providing a mechanical link between the contractile apparatus and the plasma membrane. In the absence of dystrophin, there is disruption to normal force transmission and greater stress placed upon myofibrillar and membrane proteins, leading to muscle damage. 3. Contraction protocols (involving activation and stretch of isolated muscles or muscle fibres) have been developed to assess the relative susceptibility of dystrophic (and otherwise healthy) muscles to contraction-induced injury. These protocols have been used successfully to determine the relative efficacy of different (gene, cell or pharmacological) interventions designed to ameliorate or cure the dystrophic pathology. More research is needed to develop specific 'contraction assays' that will assist in the evaluation of the clinical significance of different therapeutic strategies for muscular dystrophy.

  14. Airway Responsiveness: Role of Inflammation, Epithelium Damage and Smooth Muscle Tension

    Directory of Open Access Journals (Sweden)

    K. I. Gourgoulianis

    1999-01-01

    Full Text Available The purpose of this study was the effect of epithelium damage on mechanical responses of airway smooth muscles under different resting tension. We performed acetylcholine (ACh (10-5M-induced contraction on tracheal strips from 30 rabbits in five groups (0.5, 1, 1.5, 2 and 2.5 g before and after epithelium removal. At low resting tension (0.5-1.5g, the epithelium removal decreased the ACh-induced contractions. At 2g resting tension, the epithelium removal increased the ACh-induced contractions of airways with intact epithelium about 20%. At 2.5 g resting tension, the elevation of contraction is about 25% (p<0.01. Consequently, after epithelium loss, the resting tension determines the airway smooth muscles responsiveness. In asthma, mediators such as ACh act on already contracted inflammatory airways, which results in additional increase of contraction. In contrast, low resting tension, a condition that simulates normal tidal breathing, protects from bronchoconstriction even when the epithelium is damaged.

  15. Mystery of DNA repair: the role of the MRN complex and ATM kinase in DNA damage repair.

    Science.gov (United States)

    Czornak, Kamila; Chughtai, Sanaullah; Chrzanowska, Krystyna H

    2008-01-01

    Genomes are subject to a number of exogenous or endogenous DNA-damaging agents that cause DNA double-strand breaks (DSBs). These critical DNA lesions can result in cell death or a wide variety of genetic alterations, including deletions, translocations, loss of heterozygosity, chromosome loss, or chromosome fusions, which enhance genome instability and can trigger carcinogenesis. The cells have developed an efficient mechanism to cope with DNA damages by evolving the DNA repair machinery. There are 2 major DSB repair mechanisms: nonhomologous end joining (NHEJ) and homologous recombination (HR). One element of the repair machinery is the MRN complex, consisting of MRE11, RAD50 and NBN (previously described as NBS1), which is involved in DNA replication, DNA repair, and signaling to the cell cycle checkpoints. A number of kinases, like ATM (ataxia-telangiectasia mutated), ATR (ataxia-telangiectasia and Rad-3-related), and DNA PKcs (DNA protein kinase catalytic subunit), phosphorylate various protein targets in order to repair the damage. If the damage cannot be repaired, they direct the cell to apoptosis. The MRN complex as well as repair kinases are also involved in telomere maintenance and genome stability. The dysfunction of particular elements involved in the repair mechanisms leads to genome instability disorders, like ataxia telangiectasia (A-T), A-T-like disorder (ATLD) and Nijmegen breakage syndrome (NBS). The mutated genes responsible for these disorders code for proteins that play key roles in the process of DNA repair. Here we present a detailed review of current knowledge on the MRN complex, kinases engaged in DNA repair, and genome instability disorders.

  16. Interaction of DNA-lesions induced by sodium fluoride and radiation and its influence in apoptotic induction in cancer cell lines

    Directory of Open Access Journals (Sweden)

    Santosh Podder

    2015-01-01

    Full Text Available Fluoride is an essential trace element but also an environmental contaminant with major sources of exposure being drinking water, food and pesticides. Previous studies showed that sodium fluoride (NaF at 5 mM or more is required to induce apoptosis and chromosome aberrations and proposed that DNA damage and apoptosis play an important role in toxicity of excessive fluoride. The aim of this study is directed to understand the nature of DNA-lesions induced by NaF by allowing its interaction with radiation induced DNA-lesions. NaF 5 mM was used after observing inability to induce DNA damages and apoptosis by single exposure with 50 μM or 1 mM NaF. Co-exposure to NaF and radiation significantly increased the frequency of aberrant metaphases and exchange aberrations in human lymphocytes and arrested the cells in G1 stage instead of apoptotic death. Flow cytometric analysis, DNA fragmentation and PARP-cleavage analysis clearly indicated that 5 mM NaF together with radiation (1 Gy induced apoptosis in both U87 and K562 cells due to down regulation of expression of anti-apoptotic proteins, like Bcl2 in U87 and inhibitors of apoptotic proteins like survivin and cIAP in K562 cells. This study herein suggested that single exposure with extremely low concentration of NaF unable to induce DNA lesions whereas higher concentration induced DNA lesions interact with the radiation-induced DNA lesions. Both are probably repaired rapidly thus showed increased interactive effect. Coexposure to NaF and radiation induces more apoptosis in cancer cell lines which could be due to increased exchange aberrations through lesions interaction and downregulating anti-apoptotic genes.

  17. Air pollution and brain damage.

    Science.gov (United States)

    Calderón-Garcidueñas, Lilian; Azzarelli, Biagio; Acuna, Hilda; Garcia, Raquel; Gambling, Todd M; Osnaya, Norma; Monroy, Sylvia; DEL Tizapantzi, Maria Rosario; Carson, Johnny L; Villarreal-Calderon, Anna; Rewcastle, Barry

    2002-01-01

    Exposure to complex mixtures of air pollutants produces inflammation in the upper and lower respiratory tract. Because the nasal cavity is a common portal of entry, respiratory and olfactory epithelia are vulnerable targets for toxicological damage. This study has evaluated, by light and electron microscopy and immunohistochemical expression of nuclear factor-kappa beta (NF-kappaB) and inducible nitric oxide synthase (iNOS), the olfactory and respiratory nasal mucosae, olfactory bulb, and cortical and subcortical structures from 32 healthy mongrel canine residents in Southwest Metropolitan Mexico City (SWMMC), a highly polluted urban region. Findings were compared to those in 8 dogs from Tlaxcala, a less polluted, control city. In SWMMC dogs, expression of nuclear neuronal NF-kappaB and iNOS in cortical endothelial cells occurred at ages 2 and 4 weeks; subsequent damage included alterations of the blood-brain barrier (BBB), degenerating cortical neurons, apoptotic glial white matter cells, deposition of apolipoprotein E (apoE)-positive lipid droplets in smooth muscle cells and pericytes, nonneuritic plaques, and neurofibrillary tangles. Persistent pulmonary inflammation and deteriorating olfactory and respiratory barriers may play a role in the neuropathology observed in the brains of these highly exposed canines. Neurodegenerative disorders such as Alzheimer's may begin early in life with air pollutants playing a crucial role.

  18. Role of peroxisome proliferator-activated receptor a activation in acute myocardial damage induced by isoproterenol in rats

    Institute of Scientific and Technical Information of China (English)

    YUAN Jie; WU Jian; HANG Zhi-gang; ZHONG Xue-kuan; ZHOU Ling-wang; YU Bo

    2008-01-01

    Background Peroxisome proliferator-activated receptor(PPAR)a is one of the subtypes of PPARs.It regulates metabolism of lipid and lipoprotein,as well as glucose homeostasis.In addition,PPARa influences cellular proliferation, inflammation,differentiation and apoptosis,which plays a vital role in cardiovascular diseases.The purpose of this study was to investigate the role and mechanisms of PPARa activation in relation to acute myocardial damage induced by isoproterenol in rats.Methods Thirty male Wister rats were randomly divided into controI group,isoproterenol (Iso)injured group and fenofibrate(FF)treatment group.Acute myocardiaI damage caused by isoproterenol intraperitoneaI injection induced ischemia was established.We determined the levels of creatine kinase(CK)and lactic dehvdroqenase(LDH)in serum as welI as the concentrations of free fatty acids(FFA)in serum and myocardium.The mRNA expressions of PPARa, muscular type carnitine palmitransferase(M-CPT-1)and medium chain lipid acetyl coenzyme A dehydrogenase(MCAD) were analyzed by reverse transcription-polymerase chain reaction(RT-PCR).Results Compared with the control group.the Ievels of serum CK and LDH were significantly increased after FF and ISO treatments.Moreover.the concentrations of FFA in both serum and myocardium were obviously increased in the ISO group and FF group,while the mRNA expressions of PPARa,M-CPT-I and MCAD declined,respectively(P≤0.01).When compared with the lSO group.significant decreases in serum CK and LDH were obsewed in the FF group.The concentrations of FFA both in serum and myocardiaI tissue were markedly decreased in the FF group.while the expressions of PPARo.M-CPT-I and MCAD mRNA were increased(vs Iso,P≤O.01).Conclusions The utilization of FFA was reduced in isoproterenol induced acute myocardial damage.PPARa activation by its activator fenofibrate may play a key role in energy metabolism in acute myocardial damage induced by isoproterenol in rats.

  19. UV-B-induced Oxidative Damage and Protective Role of Exopolysaccharides in Desert Cyanobacterium Microcoleus vaginatus

    Institute of Scientific and Technical Information of China (English)

    Lan-Zhou Chen; Gao-Hong Wang; Song Hong; An Liu; Cheng Li; Yong-Ding Liu

    2009-01-01

    UV-B-induced oxidative damage and the protective effect of exopolysaccharides (EPS) in Microcoleus vaginatus, a cyanobacterium isolated from desert crust, were investigated. After being irradiated with UV-B radiation, photosynthetic activity (Fv/Fm), cellular total carbohydrates, EPS and sucrose production of irradiated cells decreased, while reducing sugars, reactive oxygen species (ROS) generation, malondialdehyde (MDA) production and DNA strand breaks increased significantly. However, when pretreated with 100 mg/L exogenous EPS, EPS production in the culture medium of UV-B stressed cells decreased significantly; Fv/Fm, cellular total carbohydrates, reducing sugars and sucrose synthase (SS) activity of irradiated cells increased significantly, while ROS generation, MDA production and DNA strand breaks of irradiated cells decreased significantly. The results suggested that EPS exhibited a significant protective effect on DNA strand breaks and lipid peroxidation by effectively eliminating ROS induced by UV-B radiation in M. vaginatus.

  20. The role of curing stresses in subsequent response, damage and failure of textile polymer composites

    Science.gov (United States)

    Heinrich, Christian; Aldridge, Michael; Wineman, Alan S.; Kieffer, John; Waas, Anthony M.; Shahwan, Khaled W.

    2013-05-01

    An integrated computational framework for textile polymer composites is introduced. A novel polymer curing model is used in connection with modeling the polymer curing process during manufacturing of textile composites. The model is based on the notion of polymer networks that are continuously formed in a body of changing shape due to changes in temperature, chemistry and external loads. Nonlinear material behavior is incorporated through nonlocal continuum damage mechanics that preserves mesh objectivity in calculations that go beyond maximum loads. The integrated model is applied to the curing of plain weave textile composites made from carbon fiber tows and Epon™862 resin. The mechanical and chemical properties are measured during curing using concurrent Brillouin and Raman light scattering. It is shown that significant stresses can develop during cure. The effect of these stresses on the manufactured part performance, when subsequent service loads are applied, is evaluated and a reduction in ultimate load, in agreement with experimental observations, is observed.

  1. Reappraisal generation after acquired brain damage: The role of laterality and cognitive control

    Science.gov (United States)

    Salas, Christian E.; Gross, James J.; Turnbull, Oliver H.

    2014-01-01

    In the past decade, there has been growing interest in the neuroanatomical and neuropsychological bases of reappraisal. Findings suggest that reappraisal activates a set of areas in the left hemisphere (LH), which are commonly associated with language abilities and verbally mediated cognitive control. The main goal of this study was to investigate whether individuals with focal damage to the LH (n = 8) were more markedly impaired on a reappraisal generation task than individuals with right hemisphere lesions (RH, n = 8), and healthy controls (HC, n = 14). The reappraisal generation task consisted of a set of ten pictures from the IAPS, depicting negative events of different sorts. Participants were asked to quickly generate as many positive reinterpretations as possible for each picture. Two scores were derived from this task, namely difficulty and productivity. A second goal of this study was to explore which cognitive control processes were associated with performance on the reappraisal task. For this purpose, participants were assessed on several measures of cognitive control. Findings indicated that reappraisal difficulty – defined as the time taken to generate a first reappraisal – did not differ between LH and RH groups. However, differences were found between patients with brain injury (LH + RH) and HC, suggesting that brain damage in either hemisphere influences reappraisal difficulty. No differences in reappraisal productivity were found across groups, suggesting that neurological groups and HC are equally productive when time constraints are not considered. Finally, only two cognitive control processes inhibition and verbal fluency- were inversely associated with reappraisal difficulty. Implications for the neuroanatomical and neuropsychological bases of reappraisal generation are discussed, and implications for neuro-rehabilitation are considered. PMID:24711799

  2. Role of Protein Kinase C (PKC in Podocytes and Development of Glomerular Damage in Diabetic Nephropathy

    Directory of Open Access Journals (Sweden)

    Beina eTeng

    2014-11-01

    Full Text Available The early glomerular changes in diabetes include a podocyte phenotype with loss of slit diaphragm proteins, changes in the actin cytoskeleton and foot process architecture. This review focusses on the role of the Protein Kinase C family in podocytes and points out the differential roles of classical, novel and atypical PKCs in podocytes. Some PKC-isoforms are indispensable for proper glomerular development and slit diaphragm maintenance whereas others might be harmful when activated in the diabetic milieu. Therefore some might be interesting treatment targets in the early phase of diabetes.

  3. Role of endothelium in radiation-induced normal tissue damages; Role de l'endothelium dans les dommages radio-induits aux tissus sains

    Energy Technology Data Exchange (ETDEWEB)

    Milliat, F

    2007-05-15

    More than half of cancers are treated with radiation therapy alone or in combination with surgery and/or chemotherapy. The goal of radiation therapy is to deliver enough ionising radiation to destroy cancer cells without exceeding the level that the surrounding healthy cells can tolerate. Unfortunately, radiation-induced normal tissue injury is still a dose limiting factor in the treatment of cancer with radiotherapy. The knowledge of normal tissue radiobiology is needed to determine molecular mechanisms involved in normal tissue pathogenic pathways in order to identify therapeutic targets and develop strategies to prevent and /or reduce side effects of radiation therapy. The endothelium is known to play a critical role in radiation-induced injury. Our work shows that endothelial cells promote vascular smooth muscle cell proliferation, migration and fibro-genic phenotype after irradiation. Moreover, we demonstrate for the first time the importance of PAI-1 in radiation-induced normal tissue damage suggesting that PAI-1 may represent a molecular target to limit injury following radiotherapy. We describe a new role for the TGF-b/Smad pathway in the pathogenesis of radiation-induced damages. TGF-b/Smad pathway is involved in the fibro-genic phenotype of VSMC induced by irradiated EC as well as in the radiation-induced PAI-1 expression in endothelial cells. (author)

  4. Apoptotic cell signaling in cancer progression and therapy.

    Science.gov (United States)

    Plati, Jessica; Bucur, Octavian; Khosravi-Far, Roya

    2011-04-01

    Apoptosis is a tightly regulated cell suicide program that plays an essential role in the development and maintenance of tissue homeostasis by eliminating unnecessary or harmful cells. Impairment of this native defense mechanism promotes aberrant cellular proliferation and the accumulation of genetic defects, ultimately resulting in tumorigenesis, and frequently confers drug resistance to cancer cells. The regulation of apoptosis at several levels is essential to maintain the delicate balance between cellular survival and death signaling that is required to prevent disease. Complex networks of signaling pathways act to promote or inhibit apoptosis in response to various cues. Apoptosis can be triggered by signals from within the cell, such as genotoxic stress, or by extrinsic signals, such as the binding of ligands to cell surface death receptors. Various upstream signaling pathways can modulate apoptosis by converging on, and thereby altering the activity of, common central control points within the apoptotic signaling pathways, which involve the BCL-2 family proteins, inhibitor of apoptosis (IAP) proteins, and FLICE-inhibitory protein (c-FLIP). This review highlights the role of these fundamental regulators of apoptosis in the context of both normal apoptotic signaling mechanisms and dysregulated apoptotic pathways that can render cancer cells resistant to cell death. In addition, therapeutic strategies aimed at modulating the activity of BCL-2 family proteins, IAPs, and c-FLIP for the targeted induction of apoptosis are briefly discussed.

  5. Apoptotic cell signaling in cancer progression and therapy†

    Science.gov (United States)

    Plati, Jessica; Bucur, Octavian; Khosravi-Far, Roya

    2011-01-01

    Apoptosis is a tightly regulated cell suicide program that plays an essential role in the development and maintenance of tissue homeostasis by eliminating unnecessary or harmful cells. Impairment of this native defense mechanism promotes aberrant cellular proliferation and the accumulation of genetic defects, ultimately resulting in tumorigenesis, and frequently confers drug resistance to cancer cells. The regulation of apoptosis at several levels is essential to maintain the delicate balance between cellular survival and death signaling that is required to prevent disease. Complex networks of signaling pathways act to promote or inhibit apoptosis in response to various cues. Apoptosis can be triggered by signals from within the cell, such as genotoxic stress, or by extrinsic signals, such as the binding of ligands to cell surface death receptors. Various upstream signaling pathways can modulate apoptosis by converging on, and thereby altering the activity of, common central control points within the apoptotic signaling pathways, which involve the BCL-2 family proteins, inhibitor of apoptosis (IAP) proteins, and FLICE-inhibitory protein (c-FLIP). This review highlights the role of these fundamental regulators of apoptosis in the context of both normal apoptotic signaling mechanisms and dysregulated apoptotic pathways that can render cancer cells resistant to cell death. In addition, therapeutic strategies aimed at modulating the activity of BCL-2 family proteins, IAPs, and c-FLIP for the targeted induction of apoptosis are briefly discussed. PMID:21340093

  6. Intercellular transfer of apoptotic signals via electrofusion

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jin Suk; Lee, Wilson; McCulloch, Christopher A., E-mail: christopher.mcculloch@utoronto.ca

    2012-05-01

    We determined whether cells that are induced to undergo anoikis by matrix detachment can initiate apoptosis in healthy cells following electroporation-induced fusion. Separate populations of MDCK cells undergoing anoikis and stained with FITC-annexin or viable MDCK cells that were labeled with spectrally discrete fluorescent beads were electroporated. Cells were analyzed by flow cytometry for enumeration of viable cells with beads, apoptotic cells or fused cells. Electroporation promoted a 49-fold increase of the percentage of viable cells that had fused with apoptotic cells. Apoptotic cell-viable cell fusions were 8-fold more likely to not attach to cell culture plastic and 2.3-fold less likely to proliferate after 24 hr incubation than viable cell fusion controls. These data demonstrate that apoptotic signals can be transferred between cells by electrofusion, possibly suggesting a novel investigative approach for optimizing targeted cell deletion in cancer treatment.

  7. Repeated low-dose 17β-estradiol treatment prevents activation of apoptotic signaling both in the synaptosomal and cellular fraction in rat prefrontal cortex following cerebral ischemia.

    Science.gov (United States)

    Stanojlović, Miloš; Zlatković, Jelena; Guševac, Ivana; Grković, Ivana; Mitrović, Nataša; Zarić, Marina; Horvat, Anica; Drakulić, Dunja

    2015-01-01

    Disturbance in blood circulation is associated with numerous pathological conditions characterized by cognitive decline and neurodegeneration. Activation of pro-apoptotic signaling previously detected in the synaptosomal fraction may underlie neurodegeneration in the prefrontal cortex of rats submitted to permanent bilateral common carotid arteries occlusion (two-vessel occlusion, 2VO). 17β-Estradiol (E) exerts potent neuroprotective effects in the brain affecting, among other, ischemia-induced pathological changes. As most significant changes in rats submitted to 2VO were observed on 7th day following the insult, of interest was to examine whether 7 day treatment with low dose of E (33.3 µg/kg/day) prevents formerly reported neurodegeneration and may represent additional therapy during the early post-ischemic period. Role of E treatment on apoptotic pathway was monitored on Bcl-2 family members, cytochrome c, caspase 3 and PARP protein level in the synaptosomal (P2) fraction of the prefrontal cortex. Furthermore, changes of these proteins were examined in the cytosolic, mitochondrial and nuclear fraction, with the emphasis on potential involvement of extracellular signal-regulated kinases (ERK) and protein kinase B (Akt) activation and their role in nuclear translocation of transcriptional nuclear factor kappa B (NF-kB) associated with alteration of Bax and Bcl-2 gene expression. The extent of cellular damage was determined using DNA fragmentation and Fluoro-Jade B staining. The absence of activation of apoptotic cascade both in the P2 and cell accompanied with decreased DNA fragmentation and number of degenerating neurons clearly indicates that E treatment ensures the efficient protection against ischemic insult. Moreover, E-mediated modulation of pro-apoptotic signaling in the cortical cellular fractions involves cooperative activation of ERK and Akt, which may be implicated in the observed prevention of neurodegenerative changes.

  8. Measuring glutamate receptor activation-induced apoptotic cell death in ischemic rat retina using the TUNEL assay

    OpenAIRE

    Ju, Won-Kyu; Kim, Keun-Young(School of Physics and Chemistry, Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea)

    2011-01-01

    Glutamate receptor activation-mediated excitotoxicity has been hypothesized to cause cell death in both acute and chronic neurodegenerative diseases including glaucoma. Although the precise mechanisms of ischemia-induced neuronal death are unknown, glutamate excitotoxicty-induced apoptotic cell death is considered to be an important component of postischemic damage in the retina. The blockade of apoptotic cell death induced by glutamate receptor activation provides strong evidence that glutam...

  9. The interplay between DNA damage response and RNA processing: the unexpected role of splicing factors as gatekeepers of genome stability

    Directory of Open Access Journals (Sweden)

    Chiara eNaro

    2015-04-01

    Full Text Available Genome integrity is constantly threatened by endogenous and exogenous factors. However its preservation is ensured by a network of pathways that prevent and/or repair the lesion, which constitute the DNA damage response (DDR. Expression of the key proteins involved in the DDR is controlled by numerous post-transcriptional mechanisms, among which pre-mRNA splicing stands out. Intriguingly, several splicing factors have been recently shown to play direct functions in DNA damage prevention and repair, which go beyond their expected splicing activity. At the same time, evidence is emerging that DNA repair proteins (DRPs can actively sustain the DDR by acting as post-transcriptional regulator of gene expression, in addition to their well-known role in the mechanisms of signaling and repair of the lesion. Herein, we will review these non-canonical functions of both splicing factors and DRPs, which suggest the existence of a tight interplay between splicing regulation and canonical DNA safeguard mechanisms ensuring genome stability.

  10. Detrimental role of the EP1 prostanoid receptor in blood-brain barrier damage following experimental ischemic stroke.

    Science.gov (United States)

    Frankowski, Jan C; DeMars, Kelly M; Ahmad, Abdullah S; Hawkins, Kimberly E; Yang, Changjun; Leclerc, Jenna L; Doré, Sylvain; Candelario-Jalil, Eduardo

    2015-12-09

    Cyclooxygenase-2 (COX-2) is activated in response to ischemia and significantly contributes to the neuroinflammatory process. Accumulation of COX-2-derived prostaglandin E2 (PGE2) parallels the substantial increase in stroke-mediated blood-brain barrier (BBB) breakdown. Disruption of the BBB is a serious consequence of ischemic stroke, and is mainly mediated by matrix metalloproteinases (MMPs). This study aimed to investigate the role of PGE2 EP1 receptor in neurovascular injury in stroke. We hypothesized that pharmacological blockade or genetic deletion of EP1 protects against BBB damage and hemorrhagic transformation by decreasing the levels and activity of MMP-3 and MMP-9. We found that post-ischemic treatment with the EP1 antagonist, SC-51089, or EP1 genetic deletion results in a significant reduction in BBB disruption and reduced hemorrhagic transformation in an experimental model of transient focal cerebral ischemia. These neurovascular protective effects of EP1 inactivation are associated with a significant reduction in MMP-9/-3, less peripheral neutrophil infiltration, and a preservation of tight junction proteins (ZO-1 and occludin) composing the BBB. Our study identifies the EP1 signaling pathway as an important link between neuroinflammation and MMP-mediated BBB breakdown in ischemic stroke. Targeting the EP1 receptor could represent a novel approach to diminish the devastating consequences of stroke-induced neurovascular damage.

  11. Lactoferrin Directly Scavenges Hydroxyl Radicals and Undergoes Oxidative Self-Degradation: A Possible Role in Protection against Oxidative DNA Damage

    Directory of Open Access Journals (Sweden)

    Yuki Ogasawara

    2014-01-01

    Full Text Available In this study, we examined the protective effect of lactoferrin against DNA damage induced by various hydroxyl radical generation systems. Lactoferrin (LF was examined with regard to its potential role as a scavenger against radical oxygen species using bovine milk LF. Native LF, iron-saturated LF (holo-LF, and apolactoferrin (apo-LF effectively suppressed strand breaks in plasmid DNA due to hydroxyl radicals produced by the Fenton reaction. In addition, both native LF and holo-LF clearly protected calf thymus DNA from fragmentation due to ultraviolet irradiation in the presence of H2O2. We also demonstrated a protective effect of all three LF molecules against 8-hydroxydeoxyguanosine (8-OHdG formation in calf thymus DNA following ultraviolet (UV irradiation with H2O2. Our results clearly indicate that native LF has reactive oxygen species-scavenging ability, independent of its nature as a masking component for transient metals. We also demonstrated that the protective effect of LF against oxidative DNA damage is due to degradation of LF itself, which is more susceptible to degradation than other bovine milk proteins.

  12. Role of advanced glycation end products (AGEs) and receptor for AGEs (RAGE) in vascular damage in diabetes.

    Science.gov (United States)

    Yamagishi, Sho-ichi

    2011-04-01

    A non-enzymatic reaction between ketones or aldehydes and the amino groups of proteins, lipids and nucleic acids contributes to the aging of macromolecules and to the development and progression of various age-related disorders such as vascular complications of diabetes, Alzheimer's disease, cancer growth and metastasis, insulin resistance and degenerative bone disease. Under hyperglycemic and/or oxidative stress conditions, this process begins with the conversion of reversible Schiff base adducts, and then to more stable, covalently-bound Amadori rearrangement products. Over a course of days to weeks, these early glycation products undergo further reactions and rearrangements to become irreversibly crossed-linked, fluorescent protein derivatives termed advanced glycation end products (AGEs). There is a growing body of evidence that AGE and their receptor RAGE (receptor for AGEs) interaction elicits oxidative stress, inflammatory reactions and thrombosis, thereby being involved in vascular aging and damage. These observations suggest that the AGE-RAGE system is a novel therapeutic target for preventing diabetic vascular complications. In this paper, we review the pathophysiological role of the AGE-RAGE-oxidative stress system and its therapeutic intervention in vascular damage in diabetes. We also discuss here the potential utility of the restriction of food-derived AGEs in diabetic vascular complications.

  13. ARK, the Apaf-1 related killer in Drosophila, requires diverse domains for its apoptotic activity.

    Science.gov (United States)

    Srivastava, M; Scherr, H; Lackey, M; Xu, D; Chen, Z; Lu, J; Bergmann, A

    2007-01-01

    In mammals and Drosophila, apoptotic caspases are under positive control of the CED-4-like proteins Apaf-1 and ARK, respectively. In an EMS-mutagenesis screen, we isolated 33 ark mutants as recessive suppressors of hid-induced apoptosis. The ark mutants are loss-of-function alleles characterized by reduced developmental apoptosis. Using the phenotypic series of these alleles, we identified helical domain I in the nucleotide oligomerization domain as critical for ARK's apoptotic activity. Interestingly, the WD40 region may also have an unanticipated positive requirement for the apoptotic activity of ARK. Considering structural information, we discuss the roles of these domains for assembly and activity of the ARK apoptosome, and propose that the WD40 region is anti-apoptotic in the absence of apoptotic signals, and pro-apoptotic in the presence of such signals. Furthermore, a defined null allele reveals that ark is required for most, but not all apoptosis suggesting the existence of an ARK-independent apoptotic pathway.

  14. The role of nitric oxide and oxidative stress in intestinal damage induced by selenium deficiency in chickens.

    Science.gov (United States)

    Yu, Jiao; Yao, Haidong; Gao, Xuejiao; Zhang, Ziwei; Wang, Jiu-Feng; Xu, Shi-Wen

    2015-02-01

    Nitric oxide (NO) is an essential messenger molecule and is associated with inflammation and oxidative stress. Although NO has important biological functions in mammals, its role in the mechanism that occurs after intestinal injuries in chickens remains unknown. The objective of the present study was to investigate the real role of NO and oxidative stress in the intestinal injuries of chickens induced by selenium (Se) deficiency. A total 150 chickens were randomly divided into the following two groups: a low-Se group (L group, fed a Se-deficient diet containing 0.020 mg/kg Se) and a control group (C group, fed a commercial diet containing 0.2 mg/kg Se). The activities and mRNA levels of glutathione peroxidase (GSH-Px), the production of glutathione (GSH) and NO, and the protein and mRNA levels of inducible nitric oxide synthase (iNOS) were examined in the intestinal tissues (duodenum, jejunum, and rectum) at 15, 25, 35, 45, and 55 days. Methane dicarboxylic aldehyde (MDA) levels were also detected by assay kits. Then, the morphologies of the tissues were observed under the microscope after hematoxylin and eosin staining (H&E staining). The results showed that Se deficiency induced higher inflammatory damage and MDA levels (P chickens and that low levels of GSH-Px and high contents of NO may exert a major role in the injury of the intestinal tract induced by Se deficiency.

  15. Mutism and auditory agnosia due to bilateral insular damage--role of the insula in human communication.

    Science.gov (United States)

    Habib, M; Daquin, G; Milandre, L; Royere, M L; Rey, M; Lanteri, A; Salamon, G; Khalil, R

    1995-03-01

    We report a case of transient mutism and persistent auditory agnosia due to two successive ischemic infarcts mainly involving the insular cortex on both hemispheres. During the 'mutic' period, which lasted about 1 month, the patient did not respond to any auditory stimuli and made no effort to communicate. On follow-up examinations, language competences had re-appeared almost intact, but a massive auditory agnosia for non-verbal sounds was observed. From close inspection of lesion site, as determined with brain resonance imaging, and from a study of auditory evoked potentials, it is concluded that bilateral insular damage was crucial to both expressive and receptive components of the syndrome. The role of the insula in verbal and non-verbal communication is discussed in the light of anatomical descriptions of the pattern of connectivity of the insular cortex.

  16. A Damage-Independent Role for 53BP1 that Impacts Break Order and Igh Architecture during Class Switch Recombination

    Directory of Open Access Journals (Sweden)

    Pedro P. Rocha

    2016-06-01

    Full Text Available During class switch recombination (CSR, B cells replace the Igh Cμ or δ exons with another downstream constant region exon (CH, altering the antibody isotype. CSR occurs through the introduction of AID-mediated double-strand breaks (DSBs in switch regions and subsequent ligation of broken ends. Here, we developed an assay to investigate the dynamics of DSB formation in individual cells. We demonstrate that the upstream switch region Sμ is first targeted during recombination and that the mechanism underlying this control relies on 53BP1. Surprisingly, regulation of break order occurs through residual binding of 53BP1 to chromatin before the introduction of damage and independent of its established role in DNA repair. Using chromosome conformation capture, we show that 53BP1 mediates changes in chromatin architecture that affect break order. Finally, our results explain how changes in Igh architecture in the absence of 53BP1 could promote inversional rearrangements that compromise CSR.

  17. Norepinephrine-induced apoptotic and hypertrophic responses in H9c2 cardiac myoblasts are characterized by different repertoire of reactive oxygen species generation

    Directory of Open Access Journals (Sweden)

    Anita Thakur

    2015-08-01

    Full Text Available Despite recent advances, the role of ROS in mediating hypertrophic and apoptotic responses in cardiac myocytes elicited by norepinephrine (NE is rather poorly understood. We demonstrate through our experiments that H9c2 cardiac myoblasts treated with 2 µM NE (hypertrophic dose generate DCFH-DA positive ROS only for 2 h; while those treated with 100 µM NE (apoptotic dose sustains generation for 48 h, followed by apoptosis. Though the levels of DCFH fluorescence were comparable at early time points in the two treatment sets, its quenching by DPI, catalase and MnTmPyP suggested the existence of a different repertoire of ROS. Both doses of NE also induced moderate levels of H2O2 but with different kinetics. Sustained but intermittent generation of highly reactive species detectable by HPF was seen in both treatment sets but no peroxynitrite was generated in either conditions. Sustained generation of hydroxyl radicals with no appreciable differences were noticed in both treatment sets. Nevertheless, despite similar profile of ROS generation between the two conditions, extensive DNA damage as evident from the increase in 8-OH-dG content, formation of γ-H2AX and PARP cleavage was seen only in cells treated with the higher dose of NE. We therefore conclude that hypertrophic and apoptotic doses of NE generate distinct but comparable repertoire of ROS/RNS leading to two very distinct downstream responses.

  18. Roles of CYP2e1 in 1,2-dichloroethane-induced liver damage in mice.

    Science.gov (United States)

    Sun, Qi; Wang, Gaoyang; Gao, Lanyue; Shi, Lei; Qi, Ying; Lv, Xiuqiang; Jin, Yaping

    2016-11-01

    The aim of this study was to explore the roles of cytochrome P450 2E1 (CYP2E1) in 1,2-dichloroethane (1,2-DCE)-induced liver damage. Two parts were included in this study: first, effect of 1,2-DCE on microsomal expression of CYP2E1, and second, potential of an inhibitor of CYP2E1 to reduce 1,2-DCE-induced liver damage. In part one, mice were exposed to 0, 0.225, 0.45, or 0.9 g/m(3) 1,2-DCE for 10 days, 3.5 h per day through static inhalation. In part two, mice were divided into blank control, solvent control, inhibitor control, 1,2-DCE-poisoned group, and low or high intervention group. In part one, compared to the control, serum alanine aminotransferase (ALT) activities and hepatic malondialdehyde (MDA) levels in 0.9 g/m(3) 1,2-DCE group, and microsomal CYP2E1 protein expression and activity in both 0.45 and 0.9 g/m(3) 1,2-DCE groups increased significantly; conversely, hepatic nonprotein sulfhydryl (NPSH) levels in both 0.45 and 0.9 g/m(3) 1,2-DCE groups and hepatic SOD activities in 0.9 g/m(3) 1,2-DCE group decreased significantly. In part two, microsomal CYP2E1 protein expression and activity decreased significantly in both low and high intervention groups compared to 1,2-DCE-poisoned group. Along with the changes of CYP2E1, hepatic MDA levels and serum ALT activities decreased; conversely, hepatic NPSH levels and SOD activities increased significantly in high intervention group. Taken together, our results suggested that 1,2-DCE could enhance CYP2E1 protein expression and enzymatic activity, which could cause oxidative damage in liver, serving as an important mechanism underlying 1,2-DCE-induced liver damage. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1430-1438, 2016.

  19. The role of EGFR/ERK/ELK-1 MAP kinase pathway in the underlying damage to diabetic rat skin

    Directory of Open Access Journals (Sweden)

    Xinhong Ge

    2013-01-01

    Full Text Available Background: Diabetes mellitus (DM is a highly prevalent disease. Atrophy and spontaneous ulcers are the most common cutaneous manifestation of diabetic dermopathy (DD. Before spontaneous ulcers, we believe there is an underlying damage stage although the mechanism is unknown. Aims: To explore the expression of extracellular signal-regulated kinase1/2 (ERK1/2, its correlated upstream protein epidermal growth factor receptor (EGFR and its downstream transcription factor E twenty-six (ETS-like 1(ELK-1in the damage of the diabetic rat skin, and to explore the role of ERK1/2 on the recessive damage to diabetic rat skin. Materials and Methods: Eighty Sprague-Dawley (SD rats weighing 260-300 g were randomly divided into control and streptozotocin (STZ-induced diabetes groups. After 0.5, 2, 4, and 8 weeks, the shaved skin specimens from the back of rats in both groups were collected to observe the histological characteristics of the skin, to measure the thickness of the epidermis and the dermis, and to observe the ultrastructure. Immunohistochemistry (IHC and Western blot techniques were used to detect the expression and activation of ERK1/2, EGFR, ELK-1 in the skin of the rats. Results: There are ultrastructural changes in the DM skin. With the continuance of the diabetes course, the thicknesses of the epidermis and dermis decreased, and the expression of phospho-ERK1/2 (P-ERK1/2, EGFR, and ELK-1 was decreased gradually in the back skin of the diabetes rats. It was significantly lower in 4 and 8 week DM than that of the normal control ( P < 0.05. The expression of P-EGFR and P-ERK1/2 in the back skin of the diabetes rats was positively correlated ( r = 0.572 P < 0.05, and the positive correlation was also obtained between P-ERK1/2 and P-ELK-1 ( r = 0.715, P < 0.05. Conclusion: The phenomenon of recessive damage exists in the skin of diabetes rats, which probably may relate to the weakness of the signal transduction: P-EGFR → ERK1/2 → ELK-1.

  20. Putrescine Plays a Positive Role in Salt-Tolerance Mechanisms by Reducing Oxidative Damage in Roots of Vegetable Soybean

    Institute of Scientific and Technical Information of China (English)

    ZHANG Gu-wen; XU Sheng-chun; HU Qi-zan; MAO Wei-hua; GONG Ya-ming

    2014-01-01

    Polyamines play important roles in plant tolerance to environmental stress. With the aim of investigating the possible involvement of putrescine (Put) in salt-tolerance mechanisms in vegetable soybean roots, exogenous Put (10 mmol L-1) and its biosynthetic inhibitor D-arginine (D-Arg) (0.5 mmol L-1) were added to nutrient solution when vegetable soybean (Glycine max L.cv. Huning 95-1) seedlings were exposed to 100 mmol L-1 sodium chloride (NaCl). The results showed that Put ameliorated but D-Arg aggravated the detrimental effects of NaCl on plant growth and biomass production. Under NaCl stress, levels of free, soluble conjugated and insoluble bound types of Put in roots of vegetable soybean were reduced, whereas those of free, soluble conjugated, and insoluble bound types of spermidine (Spd) and spermine (Spm) were increased. Exogenous Put eliminated the decrease in Put but promoted the increase of Spd and Spm. However, these changes could be reversed by D-Arg. Under NaCl stress, activities of arginine decarboxylase (ADC), S-adenosylmethionine decarboxylase (SAMDC), diamine oxidase (DAO), and polyamine oxidase (PAO) were induced, with exogenous Put promoting and D-Arg reversing these changes. Furthermore, NaCl stress decreased activities of antioxidant enzymes. Exogenous Put alleviated but D-Arg exaggerated these effects of NaCl stress, resulting in the same changes in membrane damage and reactive oxygen species (ROS) production. These results indicated that Put plays a positive role in vegetable soybean roots by activating antioxidant enzymes and thereby attenuating oxidative damage.

  1. Interaction of apoptotic cells with macrophages upregulates COX-2/PGE2 and HGF expression via a positive feedback loop.

    Science.gov (United States)

    Byun, Ji Yeon; Youn, Young-So; Lee, Ye-Ji; Choi, Youn-Hee; Woo, So-Yeon; Kang, Jihee Lee

    2014-01-01

    Recognition of apoptotic cells by macrophages is crucial for resolution of inflammation, immune tolerance, and tissue repair. Cyclooxygenase-2 (COX-2)/prostaglandin E2 (PGE2) and hepatocyte growth factor (HGF) play important roles in the tissue repair process. We investigated the characteristics of macrophage COX-2 and PGE2 expression mediated by apoptotic cells and then determined how macrophages exposed to apoptotic cells in vitro and in vivo orchestrate the interaction between COX-2/PGE2 and HGF signaling pathways. Exposure of RAW 264.7 cells and primary peritoneal macrophages to apoptotic cells resulted in induction of COX-2 and PGE2. The COX-2 inhibitor NS-398 suppressed apoptotic cell-induced PGE2 production. Both NS-398 and COX-2-siRNA, as well as the PGE2 receptor EP2 antagonist, blocked HGF expression in response to apoptotic cells. In addition, the HGF receptor antagonist suppressed increases in COX-2 and PGE2 induction. The in vivo relevance of the interaction between the COX-2/PGE2 and HGF pathways through a positive feedback loop was shown in cultured alveolar macrophages following in vivo exposure of bleomycin-stimulated lungs to apoptotic cells. Our results demonstrate that upregulation of the COX-2/PGE2 and HGF in macrophages following exposure to apoptotic cells represents a mechanism for mediating the anti-inflammatory and antifibrotic consequences of apoptotic cell recognition.

  2. Interaction of Apoptotic Cells with Macrophages Upregulates COX-2/PGE2 and HGF Expression via a Positive Feedback Loop

    Directory of Open Access Journals (Sweden)

    Ji Yeon Byun

    2014-01-01

    Full Text Available Recognition of apoptotic cells by macrophages is crucial for resolution of inflammation, immune tolerance, and tissue repair. Cyclooxygenase-2 (COX-2/prostaglandin E2 (PGE2 and hepatocyte growth factor (HGF play important roles in the tissue repair process. We investigated the characteristics of macrophage COX-2 and PGE2 expression mediated by apoptotic cells and then determined how macrophages exposed to apoptotic cells in vitro and in vivo orchestrate the interaction between COX-2/PGE2 and HGF signaling pathways. Exposure of RAW 264.7 cells and primary peritoneal macrophages to apoptotic cells resulted in induction of COX-2 and PGE2. The COX-2 inhibitor NS-398 suppressed apoptotic cell-induced PGE2 production. Both NS-398 and COX-2-siRNA, as well as the PGE2 receptor EP2 antagonist, blocked HGF expression in response to apoptotic cells. In addition, the HGF receptor antagonist suppressed increases in COX-2 and PGE2 induction. The in vivo relevance of the interaction between the COX-2/PGE2 and HGF pathways through a positive feedback loop was shown in cultured alveolar macrophages following in vivo exposure of bleomycin-stimulated lungs to apoptotic cells. Our results demonstrate that upregulation of the COX-2/PGE2 and HGF in macrophages following exposure to apoptotic cells represents a mechanism for mediating the anti-inflammatory and antifibrotic consequences of apoptotic cell recognition.

  3. New Insights on the Role of Vitamin D in the Progression of Renal Damage

    Directory of Open Access Journals (Sweden)

    Silvia Lucisano

    2013-12-01

    Full Text Available Several studies indicate a relationship between hypovitaminosis D, survival, vascular calcification and inflammation. In addition to its central role in the regulation of bone mineral metabolism, vitamin D also contributes to other systems, including the immune, cardiovascular and endocrine systems. Vitamin D analogs reduces proteinuria, in particular through suppression of the renin-angiotensin-aldosterone system (RAAS and exerts anti-inflammatory and immunomodulatory effects. In particular vitamin D deficiency contribute to an inappropriately activated RAAS, as a mechanism for progression of chronic kidney disease (CKD and/or cardiovascular disease. Human and sperimental models of CKD showed that vitamin D may interact with B and T lymphocytes and influence the phenotype and function of the antigen presenting cells and dendritic cells, promoting properties that favor the induction of tolerogenic T regulators rather than T effectory. Interstitial fibrosis may be prevented through vitamin D supplementation. Renal myofibroblast, an activated fibroblast with expression of a molecular hallmark α-smooth muscle actin (α-SMA, is generally considered the principal matrix-producing effector cells that are responsible for the excess production of extracellular matrix (ECM components in the fibrotic tissues. It turns out that calcitriol effectively blocks myofibroblast activation from interstitial fibroblasts, as evidenced by suppression of TGF-β1-mediated α-SMA expression.

  4. Role of histidine/histamine in carnosine-induced neuroprotection during ischemic brain damage.

    Science.gov (United States)

    Bae, Ok-Nam; Majid, Arshad

    2013-08-21

    Urgent need exists for new therapeutic options in ischemic stroke. We recently demonstrated that carnosine, an endogenous dipeptide consisting of alanine and histidine, is robustly neuroprotective in ischemic brain injury and has a wide clinically relevant therapeutic time window. The precise mechanistic pathways that mediate this neuroprotective effect are not known. Following in vivo administration, carnosine is hydrolyzed into histidine, a precursor of histamine. It has been hypothesized that carnosine may exert its neuroprotective activities through the histidine/histamine pathway. Herein, we investigated whether the neuroprotective effect of carnosine is mediated by the histidine/histamine pathway using in vitro primary astrocytes and cortical neurons, and an in vivo rat model of ischemic stroke. In primary astrocytes, carnosine significantly reduced ischemic cell death after oxygen-glucose deprivation, and this effect was abolished by histamine receptor type I antagonist. However, histidine or histamine did not exhibit a protective effect on ischemic astrocytic cell death. In primary neuronal cultures, carnosine was found to be neuroprotective but histamine receptor antagonists had no effect on the extent of neuroprotection. The in vivo effect of histidine and carnosine was compared using a rat model of ischemic stroke; only carnosine exhibited neuroprotection. Taken together, our data demonstrate that although the protective effects of carnosine may be partially mediated by activity at the histamine type 1 receptor on astrocytes, the histidine/histamine pathway does not appear to play a critical role in carnosine induced neuroprotection.

  5. Targeting apoptotic pathways in myocardial infarction: attenuated by phytochemicals.

    Science.gov (United States)

    Haidarali, Shaikh; Patil, Chandragouda R; Ojha, Shreesh; Mohanraj, Rajesh; Arya, Dharamvir S; Goyal, Sameer N

    2014-01-01

    Myocardial infarction (MI) is an insidious disease, gently spreading in developed and developing countries. MI is the consequence of hypoxia in myocardial tissue, which may lead to apoptosis, narcosis and followed by cardiac cell death. Activation of apoptotic pathways during MI is frequently reported in clinical, preclinical and post-mortem studies. Several mediators of apoptosis signalling cascades culminate into MI leading to cardiomyocytes death. Such involvements of ischemia-induced apoptosis in MI are widely accepted. Apoptosis is a natural phenomenon for regulating the homeostasis in cellular organelles. Unlike the necrosis, it is a synchronized energy dependent process which is carried out by shrinkage of the cell. This contraction of cells leads to squeezing of nuclei and nuclear chromatin into brusquely demarcated masses. However, such programmed cell death in several tissues, including the myocardium becomes pathogenic under certain conditions. Moreover, reactive oxygen species (ROS) generated oxidative stress also plays a key role in production of apoptosis and several associated signalling alterations which ultimately lead to MI. Recently, certain natural products, especially from the plant kingdom have been evaluated for their anti-apoptotic potential. There is an uprise in the investigations delineating the exact mechanisms through which natural phytochemicals target apoptosis associated MI. This review explores novel signalling pathways and target sites for anti-apoptotic phytochemicals having potential to check the cellular apoptosis consequent to MI. A new vista may explore the prospective treatment of MI by using apoptosis-modulating natural products.

  6. DNA binding and apoptotic induction ability of harmalol in HepG2: Biophysical and biochemical approaches.

    Science.gov (United States)

    Sarkar, Sarita; Bhattacharjee, Paromita; Bhadra, Kakali

    2016-10-25

    Harmalol administration caused remarkable reduction in proliferation of HepG2 cells with GI50 of 14.2 μM, without showing much cytotoxicity in embryonic liver cell line, WRL-68. Data from circular dichroism (CD) and differential scanning calorimetric (DSC) analysis of harmalol-CT DNA complex shows conformational changes with prominent CD perturbation and stabilization of CT DNA by 8 °C. Binding constant and stoichiometry was calculated using the above biophysical techniques. The Scatchard plot constructed from CD data showed cooperative binding, from which the cooperative binding affinity (K'ω) of 4.65 ± 0.7 × 10(5) M(-1), and n value of 4.16 were deduced. The binding parameter obtained from DSC melting data was in good agreement with the above CD data. Furthermore, dose dependent apoptotic induction ability of harmalol was studied in HepG2 cells using different biochemical assays. Generation of ROS, DNA damage, changes in cellular external and ultramorphology, alteration of membrane, formation of comet tail, decreased mitochondrial membrane potential and a significant increase in Sub Go/G1 population made the cancer cell, HepG2, prone to apoptosis. Up regulation of p53 and caspase 3 further indicated the apoptotic role of harmalol.

  7. Macrophage-expressed IFN-β contributes to apoptotic alveolar epithelial cell injury in severe influenza virus pneumonia.

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    Katrin Högner

    2013-02-01

    Full Text Available Influenza viruses (IV cause pneumonia in humans with progression to lung failure and fatal outcome. Dysregulated release of cytokines including type I interferons (IFNs has been attributed a crucial role in immune-mediated pulmonary injury during severe IV infection. Using ex vivo and in vivo IV infection models, we demonstrate that alveolar macrophage (AM-expressed IFN-β significantly contributes to IV-induced alveolar epithelial cell (AEC injury by autocrine induction of the pro-apoptotic factor TNF-related apoptosis-inducing ligand (TRAIL. Of note, TRAIL was highly upregulated in and released from AM of patients with pandemic H1N1 IV-induced acute lung injury. Elucidating the cell-specific underlying signalling pathways revealed that IV infection induced IFN-β release in AM in a protein kinase R- (PKR- and NF-κB-dependent way. Bone marrow chimeric mice lacking these signalling mediators in resident and lung-recruited AM and mice subjected to alveolar neutralization of IFN-β and TRAIL displayed reduced alveolar epithelial cell apoptosis and attenuated lung injury during severe IV pneumonia. Together, we demonstrate that macrophage-released type I IFNs, apart from their well-known anti-viral properties, contribute to IV-induced AEC damage and lung injury by autocrine induction of the pro-apoptotic factor TRAIL. Our data suggest that therapeutic targeting of the macrophage IFN-β-TRAIL axis might represent a promising strategy to attenuate IV-induced acute lung injury.

  8. Role of zinc as an antioxidant and anti-inflammatory to relieve cadmium oxidative stress induced testicular damage in rats

    Institute of Scientific and Technical Information of China (English)

    Samir Abd El-Monem Bashandy; Enayat Abdel Aziz Omara; Hossam Ebaid; Mohamed Mahmoud Amin; Mahmoud Sanad Soliman

    2016-01-01

    Objective: To investigate the role of zinc in reducing the deleterious effects of cadmium on male gonads. Methods: Rats were injected subcutaneously with CdCl2 and ZnCl2 at dose level of 2.2 mg/kg (1/40 of LD50 of cadmium per day). Results: The rats treated with cadmium exhibited a significant increase in levels of testicular malondialdehyde, tumor necrosis factor-alpha, nitrogen oxide and inducible nitrogen oxide synthase immunostaining reaction, as well as an elevation of blood hydroperoxide and follicle stimulating hormone. In addition, a significant decrease in testicular ascorbic acid, zinc, reduced glutathione, catalase, superoxide dismutase, sex organ weight, plasma testosterone and luteinizing hormone were observed in the cadmium group. Sperm motility and count were decreased with cadmium treatment, while sperm abnormalities elevated significantly. Zinc treatment was found to mitigate the toxic effects of cadmium on oxidative stress, spermatogenesis, sex hormones, and inflammatory markers. Rats injected with cadmium showed intense histopathological changes. Zinc manifested protective role and markedly reduced tissues damage induced by cadmium. Conclusions: The protective effect of zinc can be attributed to its antioxidant and anti-inflammatory properties.

  9. Role of Inositol Phosphosphingolipid Phospholipase C1, the Yeast Homolog of Neutral Sphingomyelinases in DNA Damage Response and Diseases

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    Kaushlendra Tripathi

    2015-01-01

    Full Text Available Sphingolipids play a very crucial role in many diseases and are well-known as signaling mediators in many pathways. Sphingolipids are produced during the de novo process in the ER (endoplasmic reticulum from the nonsphingolipid precursor and comprise both structural and bioactive lipids. Ceramide is the central core of the sphingolipid pathway, and its production has been observed following various treatments that can induce several different cellular effects including growth arrest, DNA damage, apoptosis, differentiation, and senescence. Ceramides are generally produced through the sphingomyelin hydrolysis and catalyzed by the enzyme sphingomyelinase (SMase in mammals. Presently, there are many known SMases and they are categorized into three groups acid SMases (aSMases, alkaline SMases (alk-SMASES, and neutral SMases (nSMases. The yeast homolog of mammalians neutral SMases is inositol phosphosphingolipid phospholipase C. Yeasts generally have inositol phosphosphingolipids instead of sphingomyelin, which may act as a homolog of mammalian sphingomyelin. In this review, we shall explain the structure and function of inositol phosphosphingolipid phospholipase C1, its localization inside the cells, mechanisms, and its roles in various cell responses during replication stresses and diseases. This review will also give a new basis for our understanding for the mechanisms and nature of the inositol phosphosphingolipid phospholipase C1/nSMase.

  10. Ultrastructural observation of human neutrophils during apoptotic cell death triggered by Entamoeba histolytica.

    Science.gov (United States)

    Sim, Seobo; Kim, Kyeong Ah; Yong, Tai-Soon; Park, Soon-Jung; Im, Kyung-il; Shin, Myeong Heon

    2004-12-01

    Neutrophils are important effector cells against protozoan extracellular parasite Entamoeba histolytica, which causes amoebic colitis and liver abscess in human beings. Apoptotic cell death of neutrophils is an important event in the resolution of inflammation and parasite's survival in vivo. This study was undertaken to investigate the ultrastructural aspects of apoptotic cells during neutrophil death triggered by Entamoeba histolytica. Isolated human neutrophils from the peripheral blood were incubated with or without live trophozoites of E. histolytica and examined by transmission electron microscopy (TEM). Neutrophils incubated with E. histolytica were observed to show apoptotic characteristics, such as compaction of the nuclear chromatin and swelling of the nuclear envelop. In contrast, neutrophils incubated in the absence of the amoeba had many protrusions of irregular cell surfaces and heterogenous nuclear chromatin. Therefore, it is suggested that Entamoeba-induced neutrophil apoptosis contribute to prevent unwanted tissue inflammation and damage in the amoeba-invaded lesions in vivo.

  11. How does ethanol induce apoptotic cell death of SK-N-SH neuroblastoma cells?*

    Institute of Scientific and Technical Information of China (English)

    Yong Moon; Yongil Kwon; Shun Yu

    2013-01-01

    A body of evidence suggests that ethanol can lead to damage of neuronal cel s. However, the me-chanism underlying the ethanol-induced damage of neuronal cel s remains unclear. The role of mi-togen-activated protein kinases in ethanol-induced damage was investigated in SK-N-SH neurob-lastoma cel s. 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide cel viability assay, DNA fragmentation detection, and flow cytometric analysis showed that ethanol induced apoptotic cel death and cel cycle arrest, characterized by increased caspase-3 activity, DNA fragmentation, nuclear disruption, and G 1 arrest of cel cycle of the SK-N-SH neuroblastoma cel s. In addition, western blot analysis indicated that ethanol induced a lasting increase in c-Jun N-terminal protein kinase activity and a transient increase in p38 kinase activity of the neuroblastoma cel s. c-Jun N-terminal protein kinase or p38 kinase inhibitors significantly reduced the ethanol-induced cel death. Ethanol also increased p53 phosphorylation, fol owed by an increase in p21 tumor sup-pressor protein and a decrease in phospho-Rb (retinoblastoma) protein, leading to alterations in the expressions and activity of cyclin dependent protein kinases. Our results suggest that ethanol me-diates apoptosis of SK-N-SH neuroblastoma cel s by activating p53-related cel cycle arrest possibly through activation of the c-Jun N-terminal protein kinase-related cel death pathway.

  12. Taurine protects HK-2 cells from oxidized LDL-induced cytotoxicity via the ROS-mediated mitochondrial and p53-related apoptotic pathways

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Chun-Yu [Graduate Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Shen, Chao-Yu [School of Medical Imaging and Radiological Sciences, Chung Shan Medical University, Taichung, Taiwan (China); Department of Medical Imaging, Chung Shan Medical University Hospital, Taichung, Taiwan (China); School of Medicine, Chung Shan Medical University, Taichung, Taiwan (China); Kang, Chao-Kai [Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan, (China); Sher, Yuh-Pyng [Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan (China); Center for Molecular Medicine, China Medical University Hospital, Taichung 404, Taiwan (China); Sheu, Wayne H.-H. [Graduate Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Division of Endocrinology and Metabolism, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan (China); School of Medicine, National Yang Ming University, Taipei, Taiwan (China); School of Medicine, National Defense Medical Center, Taipei, Taiwan (China); Chang, Chia-Che, E-mail: chia_che@dragon.nchu.edu.tw [Graduate Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Agricultural Biotechnology Center, National Chung Hsing University, Taichung, Taiwan (China); Lee, Tsung-Han, E-mail: thlee@email.nchu.edu.tw [Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan, (China); Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan (China); Agricultural Biotechnology Center, National Chung Hsing University, Taichung, Taiwan (China); Department of Biological Science and Technology, China Medical University, Taichung, Taiwan (China)

    2014-09-15

    Oxidized LDL (oxLDL) induces a pro-oxidative environment and promotes apoptosis, causing the progression of renal diseases in humans. Taurine is a semi-essential amino acid in mammals and has been shown to be a potent endogenous antioxidant. The kidney plays a pivotal role in maintaining the balance of taurine. However, the mechanisms underlying the protective effects of taurine against oxLDL-induced injury in renal epithelial cells have not been clarified. In the present study, we investigated the anti-apoptotic effects of taurine on human proximal tubular epithelial (HK-2) cells exposed to oxLDL and explored the related mechanisms. We observed that oxLDL increased the contents of ROS and of malondialdehyde (MDA), which is a lipid peroxidation by-product that acts as an indicator of the cellular oxidation status. In addition, oxLDL induced cell death and apoptosis in HK-2 cells. Pretreatment with taurine at 100 μM significantly attenuated the oxLDL-induced cytotoxicity. We determined that oxLDL triggered the phosphorylation of ERK and, in turn, the activation of p53 and other apoptosis-related events, including calcium accumulation, destabilization of the mitochondrial permeability and disruption of the balance between pro-apoptotic Bax and anti-apoptotic Bcl-2 proteins. The malfunctions induced by oxLDL were effectively blocked by taurine. Thus, our results suggested that taurine exhibits potential therapeutic activity by preventing oxLDL-induced nephrotoxicity. The inhibition of oxLDL-induced epithelial apoptosis by taurine was at least partially due to its anti-oxidant activity and its ability to modulate the ERK and p53 apoptotic pathways. - Highlights: • Oxidized LDL induced cytotoxicity and apoptosis in HK-2 cells. • Pretreatment with taurine attenuated oxLDL-induced nephrotoxicity. • Taurine protected against renal damages through inhibition of ROS generation. • Taurine prevented apoptosis through modulation of the p53 phosphorylation.

  13. Role of the prostaglandin E2 receptor agonists in TGF-β1-induced mesangial cell damage

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    Xi, Pei-pei; Xu, Yu-yin; Chen, Xiao-lan; Fan, Ya-ping; Wu, Jian-hua

    2016-01-01

    PGE2 exerts its biological effect through binding to various EP receptors that result inactivation of various signal transduction pathways. It also plays an important role in mice glomerular mesangial cells (MCs) damage induced by transforming growth factor-β1 (TGF-β1); however, the molecular mechanisms remain unknown. In the present study, we tested the efficacy of four selective agonists of PGE2 receptor, EP1A (17-phenyl trinor prostaglandin E2 ethyl amid), EP2A (butaprost), EP3A (sulprostone) and EP4A (cay10580), on mice MCs. Compared with the cAMP produced by TGF-β1, additional pretreatment of EP3A decreased the cAMP level. MCs treated with EP1A and EP3A augmented PGE2, cyclooxygenase-2 (COX-2), membrane-bound PGE synthase 1 (mPGES1), laminin (LN), connective tissue growth factor (CTGF) and cyclin D1 expression stimulated by TGFβ1. EP1A and EP3A increased the number of cells in S+G2/M phase and reduced cells in G0/G1 phase. EP1 and EP3 agonists also strengthened TGFβ1-induced mitogen-activated protein kinase (p38MAPK) and extracellular-signal-regulated kinase 1/2 (ERK1/2) phosphorylation. Whereas MCs treated with EP2A and EP4A weakened PGE2, COX-2, mPGES1, LN, CTGF and cyclin D1 expression stimulated by TGFβ1. EP2A and EP4A decreased the number of cells in S+G2/M phase and increased cells in G0/G1 phase. EP2 and EP4 agonists weakened TGFβ1-induced p38MAPK and ERK1/2 phosphorylation. These findings suggest that PGE2 has an important role in the progression of kidney disease via the EP1/EP3 receptor, whereas EP2 and EP4 receptors are equally important in preserving the progression of chronic kidney failure. Thus, agonists of EP2 and EP4 receptors may provide a basis for treating kidney damage induced by TGF-β1. PMID:27512093

  14. Excessive activation of ionotropic glutamate receptors induces apoptotic hair-cell death independent of afferent and efferent innervation

    Science.gov (United States)

    Sheets, Lavinia

    2017-01-01

    Accumulation of excess glutamate plays a central role in eliciting the pathological events that follow intensely loud noise exposures and ischemia-reperfusion injury. Glutamate excitotoxicity has been characterized in cochlear nerve terminals, but much less is known about whether excess glutamate signaling also contributes to pathological changes in sensory hair cells. I therefore examined whether glutamate excitotoxicity damages hair cells in zebrafish larvae exposed to drugs that mimic excitotoxic trauma. Exposure to ionotropic glutamate receptor (iGluR) agonists, kainic acid (KA) or N-methyl-D-aspartate (NMDA), contributed to significant, progressive hair cell loss in zebrafish lateral-line organs. To examine whether hair-cell loss was a secondary effect of excitotoxic damage to innervating neurons, I exposed neurog1a morphants—fish whose hair-cell organs are devoid of afferent and efferent innervation—to KA or NMDA. Significant, dose-dependent hair-cell loss occurred in neurog1a morphants exposed to either agonist, and the loss was comparable to wild-type siblings. A survey of iGluR gene expression revealed AMPA-, Kainate-, and NMDA-type subunits are expressed in zebrafish hair cells. Finally, hair cells exposed to KA or NMDA appear to undergo apoptotic cell death. Cumulatively, these data reveal that excess glutamate signaling through iGluRs induces hair-cell death independent of damage to postsynaptic terminals. PMID:28112265

  15. Interaction of late apoptotic and necrotic cells with vitronectin.

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    Ondrej Stepanek

    Full Text Available BACKGROUND: Vitronectin is an abundant plasma glycoprotein identified also as a part of extracellular matrix. Vitronectin is substantially enriched at sites of injured, fibrosing, inflamed, and tumor tissues where it is believed to be involved in wound healing and tissue remodeling. Little is known about the mechanism of vitronectin localization into the damaged tissues. METHODOLOGY/PRINCIPAL FINDINGS: 2E12 antibody has been described to bind a subset of late apoptotic cells. Using immunoisolation followed by mass spectrometry, we identified the antigen recognized by 2E12 antibody as vitronectin. Based on flow cytometry, we described that vitronectin binds to the late apoptotic and necrotic cells in cell cultures in vitro as well as in murine thymus and spleen in vivo. Confocal microscopy revealed that vitronectin binds to an intracellular cytoplasmic structure after the membrane rupture. CONCLUSIONS/SIGNIFICANCE: We propose that vitronectin could serve as a marker of membrane disruption in necrosis and apoptosis for flow cytometry analysis. Moreover, we suggest that vitronectin binding to dead cells may represent one of the mechanisms of vitronectin incorporation into the injured tissues.

  16. Modafinil abrogates methamphetamine-induced neuroinflammation and apoptotic effects in the mouse striatum.

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    Mariana Raineri

    Full Text Available Methamphetamine is a drug of abuse that can cause neurotoxic damage in humans and animals. Modafinil, a wake-promoting compound approved for the treatment of sleeping disorders, is being prescribed off label for the treatment of methamphetamine dependence. The aim of the present study was to investigate if modafinil could counteract methamphetamine-induced neuroinflammatory processes, which occur in conjunction with degeneration of dopaminergic terminals in the mouse striatum. We evaluated the effect of a toxic methamphetamine binge in female C57BL/6 mice (4 × 5 mg/kg, i.p., 2 h apart and modafinil co-administration (2 × 90 mg/kg, i.p., 1 h before the first and fourth methamphetamine injections on glial cells (microglia and astroglia. We also evaluated the striatal expression of the pro-apoptotic BAX and anti-apoptotic Bcl-2 proteins, which are known to mediate methamphetamine-induced apoptotic effects. Modafinil by itself did not cause reactive gliosis and counteracted methamphetamine-induced microglial and astroglial activation. Modafinil also counteracted the decrease in tyrosine hydroxylase and dopamine transporter levels and prevented methamphetamine-induced increases in the pro-apoptotic BAX and decreases in the anti-apoptotic Bcl-2 protein expression. Our results indicate that modafinil can interfere with methamphetamine actions and provide protection against dopamine toxicity, cell death, and neuroinflammation in the mouse striatum.

  17. Protective Role of Ficus carica Stem Extract against Hepatic Oxidative Damage Induced by Methanol in Male Wistar Rats

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    Mongi Saoudi

    2012-01-01

    Full Text Available The present study was aimed to investigate the antioxidant activity of Ficus carica stem extract (FE in methanol-induced hepatotoxicity in male Wistar rats. The rats were divided into two batches: 16 control rats (C drinking tap water and 16 treated rats drinking Ficus carica stem extract for six weeks. Then, each group was divided into two subgroups, and one of them was intraperitoneally injected (i.p. daily methanol at a dose of 2.37 g/kg body weight i.p. for 30 days, for four weeks. The results showed that FE was found to contain large amounts of polyphenols and carotenoids. The treatment with methanol exhibited a significant increase of serum hepatic biochemical parameters (ALT, AST, ALP, and LDH and hepatic lipid peroxidation. Hepatic antioxidant enzymes, namely, SOD, CAT, and GSH-Px, were significantly decreased in methanol-treated animals. FE treatment prior to methanol intoxication has significant role in protecting animals from methanol-induced hepatic oxidative damage.

  18. Role of damage control surgery in the treatment of Hinchey III and IV sigmoid diverticulitis: a tailored strategy.

    Science.gov (United States)

    Cirocchi, Roberto; Arezzo, Alberto; Vettoretto, Nereo; Cavaliere, Davide; Farinella, Eriberto; Renzi, Claudio; Cannata, Gaspare; Desiderio, Jacopo; Farinacci, Federico; Barberini, Francesco; Trastulli, Stefano; Parisi, Amilcare; Fingerhut, Abe

    2014-11-01

    Many of the treatment strategies for sigmoid diverticulitis are actually focusing on nonoperative and minimally invasive approaches. The aim of this systematic review was to evaluate the actual role of damage control surgery (DCS) in the treatment of generalized peritonitis caused by perforated sigmoid diverticulitis.A literature search was performed in PubMed and Google Scholar for articles published from 1960 to July 2013. Comparative and noncomparative studies that included patients who underwent DCS for complicated diverticulitis were considered.Acute Physiology and Chronic Health Evaluation score, duration of open abdomen, intensive care unit length of stay, reoperation, bowel resection performed at first operation, fecal diversion, method, and timing of closure of abdominal wall were the main outcomes of interest.According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses algorithm for the literature search and review, 10 studies were included in this systematic review. DCS was exclusively performed in diverticulitis patients with septic shock or requiring vasopressors intraoperatively. Two surgical different approaches were highlighted: limited resection of the diseased colonic segment with or without stoma or reconstruction in situ, and laparoscopic washing and drainage without colonic resection.Despite the heterogeneity of patient groups, clinical settings, and interventions included in this review, DCS appears to be a promising strategy for the treatment of Hinchey III and IV diverticulitis, complicated by septic shock. A tailored approach to each patient seems to be appropriate.

  19. Histopathological And Biological Studies On The Role Of Soybean And Broad Bean AgainstRadiation Induce Damage In Rat Kidney

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    Hanaa Fathy Waer, **Abdel El ­ Rahman Mohamed Attia

    2002-09-01

    Full Text Available Most of the physiological and histological activities in the animal body are disturbed after exposure to ionizing radiation. These disturbances are either due to direct harmful effect of radiation on the biological systems or to the indirect effect of free radicals formed in the body after irradiation. There is growing evidence that the type of food plays an important role in the prevention of chronic diseases. The biological disturbance due to ionizing radiation makes search for ways of protecting living organisms essential for controlling the radiation hazards. Much of the world population relies on legumes, as a stable food. Legumes can affectively protect cells and tissues against damage. Our present study was conducted to investigate the hazardous effects of single dose !"#$%#&f the possible protective effect of feeding beans (broad beans and soybeans against radiation exposure. Histopathological, and biological changes of kidney function in irradiated, and bean fed animals were carried out. Animals were weighted and daily food intake was determined. The result obtained revealed that soybean is an extremely rich source of protein and fat as compared to faba bean. Radiations cause a reduction in food intake and weight gain. It causes great changes in the kidney glomeruli and collecting tubules. The recovery of the cells depend on the type of feeding so, feeding soybean gives a significant radiation protection and decreases the extent of changes induced by radiation

  20. Protective role of caffeic acid on lambda cyhalothrin-induced changes in sperm characteristics and testicular oxidative damage in rats.

    Science.gov (United States)

    Abdallah, Fatma Ben; Fetoui, Hamadi; Zribi, Nassira; Fakhfakh, Feiza; Keskes, Leila

    2012-08-01

    The synthetic pyrethroids are expected to cause deleterious effects on most of the organs and especially on the male reproductive system. The current study was performed to assess the adverse effect of lambda cyhalothrin (LC) on reproductive organs and fertility in male rats and to evaluate the protective role of caffeic acid phenethyl ester (CAPE) in alleviating the detrimental effect of LC on male fertility. A total of 48 male rats were divided into 4 groups (12 rats each): control group received distilled water ad libitum and 1 ml of vehicle solution given intraperitoneally (i.p.); CAPE-treated group received a single i.p. dose of CAPE (10 μmol kg⁻¹ day⁻¹); LC-treated group received 668 ppm of LC through drinking water; and CAPE + LC-treated group received an i.p. injection of CAPE (10 μmol kg⁻¹ day⁻¹) 12 h before the LC administration. The experiment was conducted for 10 consecutive weeks. LC caused a significant increase in testicular malondialdehyde, catalase, superoxide dismutase, glutathione-S-transferase activities, and sperm abnormalities and a significant reduction in testicular glutathione concentration, sperm count, sperm motility, and a live sperm percentage. Conversely, treatment with CAPE improved the reduction in the sperm characteristics, LC-induced oxidative damage of testes and the testicular histopathological alterations. Results indicate that LC exerts significant harmful effects on the male reproductive system and that CAPE reduced the deleterious effects of LC on male fertility.

  1. Chronic NMDA administration to rats increases brain pro-apoptotic factors while decreasing anti-Apoptotic factors and causes cell death

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    Rapoport Stanley I

    2009-09-01

    Full Text Available Abstract Background Chronic N-Methyl-d-aspartate (NMDA administration to rats is reported to increase arachidonic acid signaling and upregulate neuroinflammatory markers in rat brain. These changes may damage brain cells. In this study, we determined if chronic NMDA administration (25 mg/kg i.p., 21 days to rats would alter expression of pro- and anti-apoptotic factors in frontal cortex, compared with vehicle control. Results Using real time RT-PCR and Western blotting, chronic NMDA administration was shown to decrease mRNA and protein levels of anti-apoptotic markers Bcl-2 and BDNF, and of their transcription factor phospho-CREB in the cortex. Expression of pro-apoptotic Bax, Bad, and 14-3-3ζ was increased, as well as Fluoro-Jade B (FJB staining, a marker of neuronal loss. Conclusion This alteration in the balance between pro- and anti-apoptotic factors by chronic NMDA receptor activation in this animal model may contribute to neuronal loss, and further suggests that the model can be used to examine multiple processes involved in excitotoxicity.

  2. Apoptotic activity in Libyan breast cancer

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    Boder Jamela

    2012-06-01

    Full Text Available Abstract Background We evaluated the relationship of the apoptotic activity index (AI and the standardized mitotic-apoptotic ratio (SMI/AI with clinicopathological features and prognosis in Libyan female breast cancer (BC patients. We then compared our results with corresponding results in Finnish and Nigerian female BC patients. Methods Histological samples of breast carcinoma from 130 patients were retrospectively studied: an estimation of the apoptotic activity per square millimeter (expressed as apoptotic activity index (AI, and standardized mitotic-apoptotic ratio (SMI/AI was made, and the results compared with the clinicopathological features and the patient’s survival. Results There was a statistically significant correlation between the AI and most of the clinicopathological features; the strongest association was observed for clinical stage lymph node (LN status (P = 0.005. There were also correlations between AI and histological grade (P = 0.035, large tumor size (P = 0.011 and the clinical stage (P = 0.009. There were, however, prominent AI differences between Libyan, Nigerian and Finnish populations. The mean values of AI and SMI/AI in Libyan BC patients were 12.8 apoptotic figures per square millimeter and 2.8, respectively. The Libyan AI is slightly higher than in Nigeria, but much higher than in Finland. The differences between countries are seen throughout the samples as well as being present in certain subgroups. The survival analysis indicated that short survival time was associated with high apoptotic indices values and so can identify aggressive tumors and provide significant prognostic support. The cutoff (4 and 18 apoptosis/mm2 of AI might be applied as a quantitative criterion for Libyan BC to separate the patients into good, moderate and bad prognosis groups. Conclusions The results indicated that the differences in AI among the three countries may be due to the known variation in the distribution of

  3. Protective role of melatonin in domoic acid-induced neuronal damage in the hippocampus of adult rats.

    Science.gov (United States)

    Ananth, C; Gopalakrishnakone, P; Kaur, C

    2003-01-01

    Domoic acid (DA), a kainite-receptor agonist and potent inducer of neurotoxicity, has been administered intravenously in adult rats in the present study (0.75 mg/kg body weight) to demonstrate neuronal degeneration followed by glial activation and their involvement with inducible nitric oxide synthase (iNOS) in the hippocampus. An equal volume of normal saline was administered in control rats. The pineal hormone melatonin, which protects the neurons efficiently against excitotoxicity mediated by sensitive glutamate receptor, was administered intraperitoneally (10 mg/kg body weight), 20 min before, immediately after, and 1 h and 2 h after the DA administration, to demonstrate its role in therapeutic strategy. Histopathological analysis (Nissl staining) demonstrated extensive neuronal damage in the pyramidal neurons of CA1, CA3 subfields and hilus of the dentate gyrus (DG) in the hippocampus at 5 days after DA administration. Sparsely distributed glial fibrillary acidic protein (GFAP)-immunoreactive astrocytes were observed in the hippocampus at 4-24 h after DA administration and in the control rats. Astrogliosis was evidenced by increased GFAP immunoreactivity in the areas of severe neuronal degeneration at 5 days after DA administration. Along with this, microglial cells exhibited an intense immunoreaction with OX-42, indicating upregulation of complement type 3 receptors (CR3). Ultrastructural study revealed swollen or shrunken degenerating neurons in the CA1, CA3 subfields and hilus of the DG and hypertrophied astrocytes showing accumulation of intermediate filament bundles in the cytoplasm were observed after administration of DA. Although no significant change could be observed in the mRNA level of iNOS expression between the DA-treated rats and controls at 4-24 h and at 5-day time intervals, double immunofluorescense revealed co-expression of induced iNOS with GFAP immunoreactive astrocytes, but not in the microglial cells, and iNOS expression in the neurons

  4. Cut1/separase-dependent roles of multiple phosphorylation of fission yeast cohesion subunit Rad21 in post-replicative damage repair and mitosis.

    Science.gov (United States)

    Adachi, Yoh; Kokubu, Aya; Ebe, Masahiro; Nagao, Koji; Yanagida, Mitsuhiro

    2008-03-15

    Cohesin is a multiprotein complex essential for sister-chromatid cohesion. It plays a pivotal role in proper chromosome segregation and DNA damage repair. The mitotic behavior of cohesin is controlled through its phosphorylation, which possibly induces the dissociation of cohesin from chromosomes and enhances its susceptibility to separase. Here, we report using mass spectrometry and anti-phospho antibodies that the central domain of Rad21, the separase-target subunit of Schizosaccharomyces pombe cohesin, is regulated by various kinase-induced phosphorylation at nine residues, indicating the multiple roles for S. pombe cohesin. In vegetative and non-dividing G(0) cells, Rad21 is phosphorylated by unknown S/TP-consensus kinases, in mitotic and non-mitotic cells by polo/Plo1 and CDK, and in DNA-damaged cells by Rad3/ATR. While mitotic phosphorylation is implicated in the dissociation of Rad21 and its cleavage by separase in anaphase, the Rad3/ATR-dependent damage-induced phosphorylation occurs intensively at the time of repair completion, and only in post-replicative cells. This damage-induced Rad21 phosphorylation is involved in the recovery process of cells from checkpoint arrest, and needed for the removal of cohesin by separase after the completion of damage repair. These complex phospho-regulations of Rad21 indicate the functional significance of cohesin in cell adaptation to a variety of cellular conditions.

  5. Mutation of the mouse Rad17 gene leads to embryonic lethality and reveals a role in DNA damage-dependent recombination.

    Science.gov (United States)

    Budzowska, Magda; Jaspers, Iris; Essers, Jeroen; de Waard, Harm; van Drunen, Ellen; Hanada, Katsuhiro; Beverloo, Berna; Hendriks, Rudolf W; de Klein, Annelies; Kanaar, Roland; Hoeijmakers, Jan H; Maas, Alex

    2004-09-01

    Genetic defects in DNA repair mechanisms and cell cycle checkpoint (CCC) genes result in increased genomic instability and cancer predisposition. Discovery of mammalian homologs of yeast CCC genes suggests conservation of checkpoint mechanisms between yeast and mammals. However, the role of many CCC genes in higher eukaryotes remains elusive. Here, we report that targeted deletion of an N-terminal part of mRad17, the mouse homolog of the Schizosaccharomyces pombe Rad17 checkpoint clamp-loader component, resulted in embryonic lethality during early/mid-gestation. In contrast to mouse embryos, embryonic stem (ES) cells, isolated from mRad17(5'Delta/5'Delta) embryos, produced truncated mRad17 and were viable. These cells displayed hypersensitivity to various DNA-damaging agents. Surprisingly, mRad17(5'Delta/5'Delta) ES cells were able to arrest cell cycle progression upon induction of DNA damage. However, they displayed impaired homologous recombination as evidenced by a strongly reduced gene targeting efficiency. In addition to a possible role in DNA damage-induced CCC, based on sequence homology, our results indicate that mRad17 has a function in DNA damage-dependent recombination that may be responsible for the sensitivity to DNA-damaging agents.

  6. Translocator protein (TSPO) role in aging and Alzheimer's disease.

    Science.gov (United States)

    Repalli, Jayanthi

    2014-01-01

    Cellular damage and deregulated apoptotic cell death lead to functional impairment, and a main consequence of these events is aging. Cellular damage is initiated by different stress/risk factors such as oxidative stress, inflammation, and heavy metals. These stress/risk factors affect the cellular homeostasis by altering methylation status of several aging and Alzheimer's disease associated genes; these effects can be manifested immediately after exposure to stress and at later stages of life. However, when cellular damage exceeds certain threshold levels apoptosis is initiated. This review discusses the stress factors involved in cellular damage and the role and potential of TSPO-mediated cell death in aging as well as in Alzheimer's disease, which is also characterized by extensive cell death. Mitochondrial-mediated apoptotic death through the release of cytochrome c is regulated by TSPO, and increased expression of this protein is observed in both elderly people and in patients with Alzheimer's disease. TSPO forms and mediates opening of the mitochondrial membrane pore, mPTP and oxidizes cardiolipin, and these events lead to the leakage of apoptotic death mediators, such as cytochrome c, resulting in cell death. However, TSPO has many proposed functions and can also increase steroid synthesis, which leads to inhibition of inflammation and inhibition of the release of apoptotic factors, thereby decreasing cell damage and promoting cell survival. Thus, TSPO mediates apoptosis and decreases the cell damage, which in turn dictates the process of aging as well as the functionality of organs such as the brain. TSPO modulation with ligands in the Alzheimer's disease mouse model showed improvement in behavioral symptoms, and studies in Drosophila species showed increased cell survival and prolonged lifespan in flies after TSPO inhibition. These data suggest that since effects/signs of stress can manifest at any time, prevention through change in lifestyle and TSPO

  7. Neuronal apoptotic signaling pathways probed and intervened by synthetically and modularly modified (SMM) chemokines.

    Science.gov (United States)

    Choi, Won-Tak; Kaul, Marcus; Kumar, Santosh; Wang, Jun; Kumar, I M Krishna; Dong, Chang-Zhi; An, Jing; Lipton, Stuart A; Huang, Ziwei

    2007-03-09

    As the main coreceptors for human immunodeficiency virus type 1 (HIV-1) entry, CXCR4 and CCR5 play important roles in HIV-associated dementia (HAD). HIV-1 glycoprotein gp120 contributes to HAD by causing neuronal damage and death, either directly by triggering apoptotic pathways or indirectly by stimulating glial cells to release neurotoxins. Here, to understand the mechanism of CXCR4 or CCR5 signaling in neuronal apoptosis associated with HAD, we have applied synthetically and modularly modified (SMM)-chemokine analogs derived from natural stromal cell-derived factor-1alpha or viral macrophage inflammatory protein-II as chemical probes of the mechanism(s) whereby these SMM-chemokines prevent or promote neuronal apoptosis. We show that inherently neurotoxic natural ligands of CXCR4, such as stromal cell-derived factor-1alpha or viral macrophage inflammatory protein-II, can be modified to protect neurons from apoptosis induced by CXCR4-preferring gp120(IIIB), and that the inhibition of CCR5 by antagonist SMM-chemokines, unlike neuroprotective CCR5 natural ligands, leads to neurotoxicity by activating a p38 mitogen-activated protein kinase (MAPK)-dependent pathway. Furthermore, we discover distinct signaling pathways activated by different chemokine ligands that are either natural agonists or synthetic antagonists, thus demonstrating a chemical biology strategy of using chemically engineered inhibitors of chemokine receptors to study the signaling mechanism of neuronal apoptosis and survival.

  8. Heat stress induces apoptotic-like cell death in two Pleurotus species.

    Science.gov (United States)

    Song, Chi; Chen, Qiang; Wu, Xiangli; Zhang, Jinxia; Huang, Chenyang

    2014-11-01

    High temperature is an important environmental factor that affects the growth and development of most edible fungi, however, the mechanism(s) for resistance to high temperature remains elusive. Nitric oxide is known to be able to effectively alleviate oxidative damage and plays an important role in the regulation of trehalose accumulation during heat stress in mycelia of Pleurotus eryngii var. tuoliensis. In this paper, we investigated whether heat stress can activate apoptosis-like cell death in mycelia of Pleurotus. Two Pleurotus species were used to detect morphological features characteristic of apoptosis including nuclear condensation, reactive oxygen species accumulation, and DNA fragmentation when exposed to heat stress (42 °C). The results showed that these classical apoptosis markers were apparent in Pleurotus strains after heat treatment. The heat-induced apoptosis-like cell death in Pleurotus was further probed using oligomycin and N-acetylcysteine, both of which were shown to block processes leading to apoptosis. This is the first report that apoptosis-like cell death occurs in Pleurotus species as a result of abiotic stress, and that this process can be inhibited with chemicals that block mitochondrial-induced apoptotic pathways and/or with ROS-scavenging compounds.

  9. Functional expression and characterization of Echinococcus granulosus thioredoxin peroxidase suggests a role in protection against oxidative damage.

    Science.gov (United States)

    Li, Jun; Zhang, Wen-Bao; Loukas, Alex; Lin, Ren-Yong; Ito, Akira; Zhang, Li-Hua; Jones, Malcolm; McManus, Donald P

    2004-02-01

    A full-length cDNA sequence coding for Echinococcus granulosus thioredoxin peroxidase (EgTPx) was isolated from a sheep strain protoscolex cDNA library by immunoscreening using a pool of sera from mice infected with oncospheres. EgTPx expressed as a fusion protein with glutathione S-transferase (GST) exhibited significant thiol-dependent peroxidase activity that protected plasmid DNA from damage by metal-catalyzed oxidation (MCO) in vitro. Furthermore, the suggested antioxidant role for EgTPx was reinforced in an in vivo assay, whereby its expression in BL21 bacterial cells markedly increased the tolerance and survival of the cells to high concentrations of H2O2 compared with controls. Immunolocalization studies revealed that EgTPx was specifically expressed in all tissues of the protoscolex and brood capsules. Higher intensity of labelling was detected in many, but not all, calcareous corpuscle cells in protoscoleces. The purified recombinant EgTPx protein was used to screen sera from heavily infected mice and patients with confirmed hydatid infection. Only a portion of the sera reacted positively with the EgTPx-GST fusion protein in Western blots, suggesting that EgTPx may form antibody-antigen complexes or that responses to the EgTPx antigen may be immunologically regulated. Recombinant EgTPx may prove useful for the screening of specific inhibitors that could serve as new drugs for treatment of hydatid disease. Moreover, given that TPx from different parasitic phyla were phylogenetically distant from host TPx molecules, the development of antiparasite TPx inhibitors that do not react with host TPx might be feasible.

  10. Selenium-dependent glutathione peroxidases——A highlight of the role of phospholipid hydroperoxide glutathione peroxidase in protection against oxidative damage

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Since the discovery that selenium is an integral component of the active site of the mammalian glu-tathione peroxidase, four members of the glutathione peroxidase family have been characterised: classical cellular glu-tathione peroxidase, gastrointestinal glutathione peroxidase; plasma glutathione peroxidase and phospholipid hydroperox-ide glutathione peroxidase (PHGPx). They are products of different genes and have different specificities on hydrogenperoxide and lipid hydroperoxides, the latter are generated by free radicals and can damage cell membranes and disruptcellular functions. Interestingly, PHGPx is not only active on phospholipid hydroperoxide, but also active on thyminehydroperoxide (a model compound for DNA damage) and protein hydroperoxides. This review highlights the role ofPHGPx in protection against peroxidative damage of lipids, protein and DNA.

  11. Role of apoptosis in the рathogenesis of glaucomatous optic nerve damage during primary open-angle glaucoma

    Directory of Open Access Journals (Sweden)

    M. A. Frolov

    2014-07-01

    Full Text Available This work is devoted to the study of the molecular mechanisms of programmed cell death or apoptosis in primary open-angleglaucoma. As one of the main factors in the pathogenesis of this disease appears the loss of retinal ganglion cells. Their death occursby apoptosis — programmed suicide mechanism. We consider two major apoptotic pathways, which are described in the literature —Fas-mediated and Bcl-2-dependent or mitochondrial. The existence of these paths and their regulators in many organs and tissues isdescribed, including the retina and optic nerve. Based on the analysis of domestic and foreign literature is presented modern view ofthe stages of this process in glaucoma. A thorough understanding of the mechanisms of apoptosis and their regulation may contribute to the development of new pharmacological methods of prevention and treatment of eye diseases

  12. Role of apoptosis in the рathogenesis of glaucomatous optic nerve damage during primary open-angle glaucoma

    Directory of Open Access Journals (Sweden)

    M. A. Frolov

    2013-01-01

    Full Text Available This work is devoted to the study of the molecular mechanisms of programmed cell death or apoptosis in primary open-angleglaucoma. As one of the main factors in the pathogenesis of this disease appears the loss of retinal ganglion cells. Their death occursby apoptosis — programmed suicide mechanism. We consider two major apoptotic pathways, which are described in the literature —Fas-mediated and Bcl-2-dependent or mitochondrial. The existence of these paths and their regulators in many organs and tissues isdescribed, including the retina and optic nerve. Based on the analysis of domestic and foreign literature is presented modern view ofthe stages of this process in glaucoma. A thorough understanding of the mechanisms of apoptosis and their regulation may contribute to the development of new pharmacological methods of prevention and treatment of eye diseases

  13. In vitro Study on Role of Hsp70 Expression in DNA Damage of Human Embryonic Lung Cells Exposed to Benzo[a]pyrene

    Institute of Scientific and Technical Information of China (English)

    YA-JUAN GAO; CHENG-FENG XIAO; SHENG CHEN; RUI-BO WANG; HAN-ZHEN HE; ROBERT M TANGUAY; TANG-CHUN WU

    2004-01-01

    Objective Benzo[a]pyrene (B[a]P), a ubiquitous environmental pollutant, is a potent procarcinogen and mutagen that can elicit tumors, leading to malignancy. Heat shock proteins (Hsp) have been shown to protect cells against damages caused by various stresses including exposure to numerous chemicals. Whether Hsps, or more specifically Hsp70, are involved in repair of B[a]P-induced DNA damage is currently unknown. Methods We assessed the potential role of the inducible form of Hsp70 in B[a]P-induced DNA damage of human embryonic lung (HEL) cells using immunoblot and the comet assay (i.e., the single cell gel electrophoresis assay). Results Exposure to B[a]P induced a dose-dependent decrease in the level of Hsp70, but a dose-dependent increase in DNA damage both in untreated (control) HEL cells and in cells preconditioned by a heat treatment. Heat preconditioning prior to B[a]P exposure potentiated the effect of B[a]P at a low dose (10 (mol/L), but appeared to be protective at higher doses. There was a negative correlation between Hsp70 level and DNA damage in the non-preheated as well as in the preconditioned cells. Conclusion These data suggest that exposure of HEL cells to B[a]P may induce a dose-dependent reduction in the levels of the inducible Hsp70. The detailed mechanisms for the reduction of Hsp70 levels by B[a]P and the role of Hsp70 in DNA damage under different concentrations of B[a]P remains to be determined.

  14. Stabilization Of Apoptotic Cells: Generation Of Zombie Cells

    Directory of Open Access Journals (Sweden)

    José A. Sánchez Alcázar

    2015-08-01

    Stabilization of apoptotic cells can be used for reliable detection and quantification of apoptosis in cultured cells and may allow a safer administration of apoptotic cells in clinical applications. Furthermore, it opens new avenues in the functional reconstruction of apoptotic cells for longer preservation.

  15. Use of the Comet assay to investigate the role of superoxide in glutathione-induced DNA damage.

    Science.gov (United States)

    Thomas, S; Lowe, J E; Hadjivassiliou, V; Knowles, R G; Green, I C; Green, M H

    1998-02-04

    Although glutathione is an important scavenging molecule within the cell, it can also act as a pro-oxidant and at biological concentrations (1 mM) can induce DNA damage. We have used a sensitive cell-free Comet assay for DNA strand breakage to investigate this damage and to try to determine the active species involved. We show a substantial protection against glutathione-mediated DNA damage by superoxide dismutase (200 U/ml) and complete protection by combined superoxide dismutase and catalase. Damage is also prevented by EDTA but only at 100 mM and is not prevented by the chelating agent diethylenetriamine-pentaacetic acid (100 microM). Although superoxide is known to potentiate DNA damage by other reactive species, none of these indirect mechanisms seem to account for our results and it is possible that superoxide may damage DNA directly. Under the same experimental conditions, S-nitrosoglutathione requires ultraviolet A photolysis to cause DNA strand breakage and superoxide dismutase increases the level of this damage. When intact human lymphocytes are incubated with glutathione (1 mM) in phosphate buffer, DNA damage is also observed, but in this case it is completely preventable by catalase, with no protective effect of superoxide dismutase. Since cellular scavenging systems are not completely protective against reactive species formed from autooxidation of extracellular glutathione and since glutathione and oxygen are ubiquitously present within cells, our results imply that cells may have a mechanism of preventing autooxidation, rather than simply relying on scavenging the reactive species formula.

  16. Regulation of apoptotic signal transduction pathways by the heat shock proteins

    Institute of Scientific and Technical Information of China (English)

    LI; Zhengyu; ZHAO; Xia; WEI; Yuquan

    2004-01-01

    The study about apoptotic signal transductions has become a project to reveal the molecular mechanisms of apoptosis. Heat shock proteins (hsps), which play an important role in cell growth and apoptosis, have attracted great attentions. A lot of researches have showed there is a hsps superfamily including hsp90, hsp70, hsp60 and hsp27, etc., which regulates the biological behaviors of cells, particularly apoptotic signal transduction in Fas pathway, JNK/SAPK pathway and caspases pathway at different levels, partly by the function of molecular chaperone.

  17. Homocysteine and its thiolactone may promote apoptotic events in blood platelets in vitro.

    Science.gov (United States)

    Olas, Beata; Malinowska, Joanna; Rywaniak, Joanna

    2010-01-01

    The actions of homocysteine and its major metabolite, cyclic thioester, homocysteine thiolactone on endothelial cells, blood platelets, plasmatic fibrinogen and plasminogen--the important major components of haemostasis, regulating the flowing properties of blood--are complex and sometimes controversial. Homocysteine (Hcys) can promote apoptosis in endothelial cells, but the role of Hcys and its thiolactone in the apoptotic process in blood platelets is unknown. In order to study the appearance of apoptosis in platelets after treatment with the reduced form of Hcys or its thiolactone different markers were chosen: annexin V binding (phosphatidylserine exposure), platelet microparticle formation, mitochondrial membrane depolarization and αIIbβ3 expression in vitro. Apoptotic events and platelet activation were measured by a flow cytometer. In gel-filtered platelets treated with different concentrations of the reduced form of Hcys (25, 50 and 100 µM, 10 min) a significant increase of phosphatidylserine exposure (about 37% at the highest concentration, p < 0.001) and platelet microparticle formation were observed. Homocysteine caused also a dose-dependent depolarization of mitochondrial potential. The same apoptotic markers appeared in HTL-treated platelets (0.2 and 1 µM). Moreover, resveratrol (25 µM), a well known antioxidant, distinctly reduced the level of apoptotic markers. The obtained results indicate that Hcys and its thiolactone may promote in vitro apoptotic events in human gel-filtered platelets.

  18. Inhibitory effects of apoptotic cell ingestion upon endotoxin-driven myeloid dendritic cell maturation.

    Science.gov (United States)

    Stuart, Lynda M; Lucas, Mark; Simpson, Cathy; Lamb, Jonathan; Savill, John; Lacy-Hulbert, Adam

    2002-02-15

    Dendritic cells (DCs) are the sentinels of the immune system, able to interact with both naive and memory T cells. The recent observation that DCs can ingest cells dying by apoptosis has raised the possibility that DCs may, in fact, present self-derived Ags, initiating both autoimmunity and tumor-specific responses, especially if associated with appropriate danger signals. Although the process of ingestion of apoptotic cells has not been shown to induce DC maturation, the exact fate of these phagocytosing DCs remains unclear. In this paper we demonstrate that DCs that ingest apoptotic cells are able to produce TNF-alpha but have a diminished ability to produce IL-12 in response to external stimuli, a property that corresponds to a failure to up-regulate CD86. By single-cell analysis we demonstrate that these inhibitory effects are restricted to those DCs that have engulfed apoptotic cells, with bystander DCs remaining unaffected. These changes were independent of the production of anti-inflammatory cytokines TGF-beta1 and IL-10 and corresponded with a diminished capacity to stimulate naive T cells. Thus, the ingestion of apoptotic cells is not an immunologically null event but is capable of modulating DC maturation. These results have important implications for our understanding of the role of clearance of dying cells by DCs not only in the normal resolution of inflammation but also in control of subsequent immune responses to apoptotic cell-derived Ags.

  19. Apico-basal forces exerted by apoptotic cells drive epithelium folding.

    Science.gov (United States)

    Monier, Bruno; Gettings, Melanie; Gay, Guillaume; Mangeat, Thomas; Schott, Sonia; Guarner, Ana; Suzanne, Magali

    2015-02-12

    Epithelium folding is a basic morphogenetic event that is essential in transforming simple two-dimensional epithelial sheets into three-dimensional structures in both vertebrates and invertebrates. Folding has been shown to rely on apical constriction. The resulting cell-shape changes depend either on adherens junction basal shift or on a redistribution of myosin II, which could be driven by mechanical signals. Yet the initial cellular mechanisms that trigger and coordinate cell remodelling remain largely unknown. Here we unravel the active role of apoptotic cells in initiating morphogenesis, thus revealing a novel mechanism of epithelium folding. We show that, in a live developing tissue, apoptotic cells exert a transient pulling force upon the apical surface of the epithelium through a highly dynamic apico-basal myosin II cable. The apoptotic cells then induce a non-autonomous increase in tissue tension together with cortical myosin II apical stabilization in the surrounding tissue, eventually resulting in epithelium folding. Together our results, supported by a theoretical biophysical three-dimensional model, identify an apoptotic myosin-II-dependent signal as the initial signal leading to cell reorganization and tissue folding. This work further reveals that, far from being passively eliminated as generally assumed (for example, during digit individualization), apoptotic cells actively influence their surroundings and trigger tissue remodelling through regulation of tissue tension.

  20. Leptin suppresses non-apoptotic cell death in ischemic rat cardiomyocytes by reduction of iPLA{sub 2} activity

    Energy Technology Data Exchange (ETDEWEB)

    Takatani-Nakase, Tomoka, E-mail: nakase@mukogawa-u.ac.jp; Takahashi, Koichi, E-mail: koichi@mukogawa-u.ac.jp

    2015-07-17

    Caspase-independent, non-apoptotic cell death is an important therapeutic target in myocardial ischemia. Leptin, an adipose-derived hormone, is known to exhibit cytoprotective effects on the ischemic heart, but the mechanisms are poorly understood. In this research, we found that pretreatment of leptin strongly suppressed ischemic-augmented nuclear shrinkage and non-apoptotic cell death on cardiomyocytes. Leptin was also shown to significantly inhibit the activity of iPLA{sub 2}, which is considered to play crucial roles in non-apoptotic cell death, resulting in effective prevention of ischemia-induced myocyte death. These findings provide the first evidence of a protective mechanism of leptin against ischemia-induced non-apoptotic cardiomyocyte death. - Highlights: • Myocardial ischemia-model induces in caspase-independent, non-apoptotic cell death. • Leptin strongly inhibits ischemic-augmented non-apoptotic cell death. • Leptin reduces iPLA{sub 2} activity, leading to avoidance of non-apoptotic cell death.

  1. The two different isoforms of the RSC chromatin remodeling complex play distinct roles in DNA damage responses.

    Science.gov (United States)

    Chambers, Anna L; Brownlee, Peter M; Durley, Samuel C; Beacham, Tracey; Kent, Nicholas A; Downs, Jessica A

    2012-01-01

    The RSC chromatin remodeling complex has been implicated in contributing to DNA double-strand break (DSB) repair in a number of studies. Both survival and levels of H2A phosphorylation in response to damage are reduced in the absence of RSC. Importantly, there is evidence for two isoforms of this complex, defined by the presence of either Rsc1 or Rsc2. Here, we investigated whether the two isoforms of RSC provide distinct contributions to DNA damage responses. First, we established that the two isoforms of RSC differ in the presence of Rsc1 or Rsc2 but otherwise have the same subunit composition. We found that both rsc1 and rsc2 mutant strains have intact DNA damage-induced checkpoint activity and transcriptional induction. In addition, both strains show reduced non-homologous end joining activity and have a similar spectrum of DSB repair junctions, suggesting perhaps that the two complexes provide the same functions. However, the hypersensitivity of a rsc1 strain cannot be complemented with an extra copy of RSC2, and likewise, the hypersensitivity of the rsc2 strain remains unchanged when an additional copy of RSC1 is present, indicating that the two proteins are unable to functionally compensate for one another in DNA damage responses. Rsc1, but not Rsc2, is required for nucleosome sliding flanking a DNA DSB. Interestingly, while swapping the domains from Rsc1 into the Rsc2 protein does not compromise hypersensitivity to DNA damage suggesting they are functionally interchangeable, the BAH domain from Rsc1 confers upon Rsc2 the ability to remodel chromatin at a DNA break. These data demonstrate that, despite the similarity between Rsc1 and Rsc2, the two different isoforms of RSC provide distinct functions in DNA damage responses, and that at least part of the functional specificity is dictated by the BAH domains.

  2. Non-apoptotic programmed cell death with paraptotic-like features in bleomycin-treated plant cells is suppressed by inhibition of ATM/ATR pathways or NtE2F overexpression.

    Science.gov (United States)

    Smetana, Ondřej; Široký, Jiří; Houlné, Guy; Opatrný, Zdeněk; Chabouté, Marie-Edith

    2012-04-01

    In plants, different forms of programmed cell death (PCD) have been identified, but they only partially correspond to those described for animals, which is most probably due to structural differences between animal and plant cells. Here, the results show that in tobacco BY-2 cells, bleomycin (BLM), an inducer of double-strand breaks (DSBs), triggers a novel type of non-apoptotic PCD with paraptotic-like features. Analysis of numerous PCD markers revealed an extensive vacuolization, vacuolar rupture, and chromatin condensation, but no apoptotic DNA fragmentation, fragmentation of the nuclei, or sensitivity to caspase inhibitors. BLM-induced PCD was cell cycle regulated, occurring predominantly upon G(2)/M cell cycle checkpoint activation. In addition, this paraptotic-like PCD was at least partially inhibited by caffeine, a known inhibitor of DNA damage sensor kinases ATM and ATR. Interestingly, overexpression of one NtE2F transcriptional factor, whose homologues play a dual role in animal apoptosis and DNA repair, reduced PCD induction and modulated G(2)/M checkpoint activation in BY-2 cells. These observations provide a solid ground for further investigations into the paraptotic-like PCD in plants, which might represent an ancestral non-apoptotic form of PCD conserved among animals, protists, and plants.

  3. The AtRAD21.1 and AtRAD21.3 Arabidopsis cohesins play a synergistic role in somatic DNA double strand break damage repair

    OpenAIRE

    2014-01-01

    Background The RAD21 cohesin plays, besides its well-recognised role in chromatid cohesion, a role in DNA double strand break (dsb) repair. In Arabidopsis there are three RAD21 paralog genes (AtRAD21.1, AtRAD21.2 and AtRAD21.3), yet only AtRAD21.1 has been shown to be required for DNA dsb damage repair. Further investigation of the role of cohesins in DNA dsb repair was carried out and is here reported. Results We show for the first time that not only AtRAD21.1 but also AtRAD21.3 play a role ...

  4. On the Role of Urban and Vegetative Land Cover in the Identification of Tornado Damage Using Dual-Resolution Multispectral Satellite Imagery

    Science.gov (United States)

    Kingfield, D.; de Beurs, K.

    2014-12-01

    It has been demonstrated through various case studies that multispectral satellite imagery can be utilized in the identification of damage caused by a tornado through the change detection process. This process involves the difference in returned surface reflectance between two images and is often summarized through a variety of ratio-based vegetation indices (VIs). Land cover type plays a large contributing role in the change detection process as the reflectance properties of vegetation can vary based on several factors (e.g. species, greenness, density). Consequently, this provides the possibility for a variable magnitude of loss, making certain land cover regimes less reliable in the damage identification process. Furthermore, the tradeoff between sensor resolution and orbital return period may also play a role in the ability to detect catastrophic loss. Moderate resolution imagery (e.g. Moderate Resolution Imaging Spectroradiometer (MODIS)) provides relatively coarse surface detail with a higher update rate which could hinder the identification of small regions that underwent a dynamic change. Alternatively, imagery with higher spatial resolution (e.g. Landsat) have a longer temporal return period between successive images which could result in natural recovery underestimating the absolute magnitude of damage incurred. This study evaluates the role of land cover type and sensor resolution on four high-end (EF3+) tornado events occurring in four different land cover groups (agriculture, forest, grassland, urban) in the spring season. The closest successive clear images from both Landsat 5 and MODIS are quality controlled for each case. Transacts of surface reflectance across a homogenous land cover type both inside and outside the damage swath are extracted. These metrics are synthesized through the calculation of six different VIs to rank the calculated change metrics by land cover type, sensor resolution and VI.

  5. The Protective Role of Hyaluronic Acid in Cr(VI-Induced Oxidative Damage in Corneal Epithelial Cells

    Directory of Open Access Journals (Sweden)

    Wei Wu

    2017-01-01

    Full Text Available Cr(VI exposure could produce kinds of intermediates and reactive oxygen species, both of which were related to DNA damage. Hyaluronan (HA has impressive biological functions and was reported to protect corneal epithelial cells against oxidative damage induced by ultraviolet B, benzalkonium chloride, and sodium lauryl sulfate. So the aim of our study was to investigate HA protection on human corneal epithelial (HCE cells against Cr(VI-induced toxic effects. The HCE cell lines were exposed to different concentrations of K2Cr2O7 (1.875, 3.75, 7.5, 15.0, and 30 μM or a combination of K2Cr2O7 and 0.2% HA and incubated with different times (15 min, 30 min, and 60 min. Our data showed that Cr(VI exposure could cause decreased cell viability, increased DNA damage, and ROS generation to the HCE cell lines. But incubation of HA increased HCE cell survival rates and decreased DNA damage and ROS generation induced by Cr(VI in a dose- and time-dependent manner. We report for the first time that HA can protect HCE cells against the toxicity of Cr(VI, indicating that it will be a promising therapeutic agent to corneal injuries caused by Cr(VI.

  6. Lung damage in mice after inhalation of nanofilm spray products: the role of perfluorination and free hydroxyl groups

    DEFF Research Database (Denmark)

    Nørgaard, Asger W; Larsen, Søren T.; Hammer, Maria;

    2010-01-01

    Exposures to two commercial nanofilm spray products (NFPs), a floor sealant (NFP 1) and a coating product for tiles (NFP 2), were investigated for airway irritation, airway inflammation, and lung damage in a mouse inhalation model. The particle exposure was characterized by particle number, parti...... groups in the silanes/alkylsiloxanes was also critical for the toxicity....

  7. ANTIMUTAGENICITY OF CINNAMALDEHYDE AND VANILLIN IN HUMAN CELLS: GLOBAL GENE EXPRESSION AND POSSIBLE ROLE OF DNA DAMAGE AND REPAIR

    Science.gov (United States)

    This study investigated the possibility that chemicals identified as antimutagens may, in fact, operate through a mechanism involving DNA damage. We addressed this question by using two chemicals to which a large proportion of the population are exposed: vanillin and cinnemaldehy...

  8. The C. elegans gene pme-5: molecular cloning and role in the DNA-damage response of a tankyrase orthologue.

    Science.gov (United States)

    Gravel, Catherine; Stergiou, Lilli; Gagnon, Steve N; Desnoyers, Serge

    2004-02-03

    Tankyrases are recently identified proteins characterized by ankyrin repeats and a poly(ADP-ribose) polymerase (PARP) signature motif. In vertebrates, tankyrases mediate protein-protein interactions via the ankyrin domain. Many partners have been identified that could function in telomere maintenance, signal transduction in vesicular transport, and cell death. To further our knowledge of tankyrases and to study their function in development, we sought and found a tankyrase-related gene in Caenorhabditis elegans that we named pme-5 (poly(ADP-ribose) metabolism enzyme-5). The protein encoded includes a large ankyrin domain and a catalytic PARP domain containing the well-conserved PARP signature sequence and the regulatory region. Unlike other tankyrases, PME-5 lacks a sterile-alpha module (SAM), but has a coiled coil domain which may mediate oligomerization. We also found that pme-5 mRNA is alternatively spliced at the fifth exon, producing a long (PME-5L) and a short (PME-5S) transcript. Both isoforms are constitutively expressed during the life cycle of C. elegans. We also show DNA damage increases expression of pme-5, a response that requires the DNA damage checkpoint gene hus-1. Moreover, DNA damage-induced germ cell apoptosis was slightly increased in pme-5(RNAi) hermaphrodites. Altogether, these data indicate that pme-5 is part of a DNA damage response pathway which leads to apoptosis in C. elegans.

  9. ROLE OF LIPID-PEROXIDATION AND DNA DAMAGE IN PARAQUAT TOXICITY AND THE INTERACTION OF PARAQUAT WITH IONIZING-RADIATION

    NARCIS (Netherlands)

    PETER, B; WARTENA, M; KAMPINGA, HH; KONINGS, AWT

    1992-01-01

    Since the introduction of paraquat (PQ) as a herbicide in 1963, there have been many speculations concerning the critical lesion in PQ toxicity. Damage to membrane lipids might be an initial event leading to PQ-induced cell killing. The ability of PQ to induce lipid peroxidation was tested in liver

  10. A divergent role of the SIRT1-TopBP1 axis in regulating metabolic checkpoint and DNA damage checkpoint.

    Science.gov (United States)

    Liu, Tongzheng; Lin, Yi-Hui; Leng, Wenchuan; Jung, Sung Yun; Zhang, Haoxing; Deng, Min; Evans, Debra; Li, Yunhui; Luo, Kuntian; Qin, Bo; Qin, Jun; Yuan, Jian; Lou, Zhenkun

    2014-12-04

    DNA replication is executed only when cells have sufficient metabolic resources and undamaged DNA. Nutrient limitation and DNA damage cause a metabolic checkpoint and DNA damage checkpoint, respectively. Although SIRT1 activity is regulated by metabolic stress and DNA damage, its function in these stress-mediated checkpoints remains elusive. Here we report that the SIRT1-TopBP1 axis functions as a switch for both checkpoints. With glucose deprivation, SIRT1 is activated and deacetylates TopBP1, resulting in TopBP1-Treslin disassociation and DNA replication inhibition. Conversely, SIRT1 activity is inhibited under genotoxic stress, resulting in increased TopBP1 acetylation that is important for the TopBP1-Rad9 interaction and activation of the ATR-Chk1 pathway. Mechanistically, we showed that acetylation of TopBP1 changes the conformation of TopBP1, thereby facilitating its interaction with distinct partners in DNA replication and checkpoint activation. Taken together, our studies identify the SIRT1-TopBP1 axis as a key signaling mode in the regulation of the metabolic checkpoint and the DNA damage checkpoint.

  11. Metallothionein treatment reduces proinflammatory cytokines IL-6 and TNF-alpha and apoptotic cell death during experimental autoimmune encephalomyelitis (EAE)

    DEFF Research Database (Denmark)

    Penkowa, M; Hidalgo, J

    2001-01-01

    , which is characterized by significant inflammation and neuroglial damage. We have recently shown that the exogenous administration of the antioxidant protein zinc-metallothionein-II (Zn-MT-II) significantly decreased the clinical symptoms, mortality, and leukocyte infiltration of the CNS during EAE...... apoptotic cell death of neurons and oligodendrocytes during EAE, as judged by using TUNEL and immunoreactivity for cytochrome c and caspases 1 and 3. In contrast, the number of apoptotic lymphocytes and macrophages was less affected by Zn-MT-II treatment. The Zn-MT-II-induced decrease in proinflammatory...

  12. Apoptotic cells activate AMP-activated protein kinase (AMPK) and inhibit epithelial cell growth without change in intracellular energy stores.

    Science.gov (United States)

    Patel, Vimal A; Massenburg, Donald; Vujicic, Snezana; Feng, Lanfei; Tang, Meiyi; Litbarg, Natalia; Antoni, Angelika; Rauch, Joyce; Lieberthal, Wilfred; Levine, Jerrold S

    2015-09-11

    Apoptosis plays an indispensable role in the maintenance and development of tissues. We have shown that receptor-mediated recognition of apoptotic target cells by viable kidney proximal tubular epithelial cells (PTECs) inhibits the proliferation and survival of PTECs. Here, we examined the effect of apoptotic targets on PTEC cell growth (cell size during G1 phase of the cell cycle). Using a cell culture model, we show that apoptotic cells potently activate AMP-activated protein kinase (AMPK), a highly sensitive sensor of intracellular energy stores. AMPK activation leads to decreased activity of its downstream target, ribosomal protein p70 S6 kinase (p70S6K), and concomitant inhibition of cell growth. Importantly, these events occur without detectable change in intracellular levels of AMP, ADP, or ATP. Inhibition of AMPK, either pharmacologically by compound C or molecularly by shRNA, diminishes the effects of apoptotic targets and largely restores p70S6K activity and cell size to normal levels. Apoptotic targets also inhibit Akt, a second signaling pathway regulating cell growth. Expression of a constitutively active Akt construct partially relieved cell growth inhibition but was less effective than inhibition of AMPK. Inhibition of cell growth by apoptotic targets is dependent on physical interaction between apoptotic targets and PTECs but independent of phagocytosis. We conclude that receptor-mediated recognition of apoptotic targets mimics the effects of intracellular energy depletion, activating AMPK and inhibiting cell growth. By acting as sentinels of environmental change, apoptotic death may enable nearby viable cells, especially nonmigratory epithelial cells, to monitor and adapt to local stresses.

  13. CX3CL1(+ Microparticles Mediate the Chemoattraction of Alveolar Macrophages toward Apoptotic Acute Promyelocytic Leukemic Cells

    Directory of Open Access Journals (Sweden)

    Wen-Hui Tsai

    2014-02-01

    Full Text Available Background/Aims: During the resolution phase of inflammation, release of “find-me” signals by apoptotic cells is crucial in the chemoattraction of macrophages toward apoptotic cells for subsequent phagocytosis, in which microparticles derived from apoptotic cells (apo-MPs are involved. A recent study reports that CX3CL1 is released from apoptotic cells to stimulate macrophages chemotaxis. In this study, we investigated the role of CX3CL1 in the apo-MPs in the cell-cell interaction between alveolar macrophage NR8383 cells and apoptotic all-trans retinoic acid-treated NB4 (ATRA-NB4 cells. Methods/Results: Apoptotic ATRA-NB4 cells and their conditioning medium (CM enhanced the chemoattraction of NR8383 cells as well as their phagocytosis activity in engulfing apoptotic ATRA-NB4 cells. The levels of CX3CL1(+ apo-MPs and CX3CL1 were rapidly elevated in the CM of ATRA-NB4 cell culture after induction of apoptosis. Both exogenous CX3CL1 and apo-MPs enhanced the transmigration of NR8383 cells toward apoptotic ATRA-NB4 cells. This pro-transmigratory activity was able to be partially inhibited either by blocking the CX3CR1 (CX3CL1 receptor of NR8383 cells with its specific antibody or by blocking the surface CX3CL1 of apo-MPs with its specific antibody before incubating these apo-MPs with NR8383 cells. Conclusion: CX3CL1(+ apo-MPs released by apoptotic cells mediate the chemotactic transmigration of alveolar macrophages.

  14. DNA damage responses: mechanisms and roles in human disease: 2007 G.H.A. Clowes Memorial Award Lecture.

    Science.gov (United States)

    Kastan, Michael B

    2008-04-01

    Significant progress has been made in recent years in elucidating the molecular controls of cellular responses to DNA damage in mammalian cells. Much of our understanding of the mechanisms involved in cellular DNA damage response pathways has come from studies of human cancer susceptibility syndromes that are altered in DNA damage responses. Ataxia-telangiectasia mutated (ATM), the gene mutated in the disorder ataxia-telangiectasia, codes for a protein kinase that is a central mediator of responses to DNA double-strand breaks (DSB) in cells. Once activated, ATM phosphorylates numerous substrates in the cell that modulate the response of the cell to the DNA damage. We recently developed a novel system to create DNA DSBs at defined endogenous sites in the human genome and used this system to detect protein recruitment and loss at and around these breaks by chromatin immunoprecipitation. Results from this system showed the functional importance of ATM kinase activity and phosphorylation in the response to DSBs and supported a model in which ordered chromatin structure changes that occur after DNA breakage and that depend on functional NBS1 and ATM facilitate DNA DSB repair. Insights about these pathways provide us with opportunities to develop new approaches to benefit patients. Examples and opportunities for developing inhibitors that act as sensitizers to chemotherapy or radiation therapy or activators that could improve responses to cellular stresses, such as oxidative damage, are discussed. Relevant to the latter, we have shown benefits of an ATM activator in disease settings ranging from metabolic syndrome to cancer prevention.

  15. Regulation of signal transducer and activator of transcription 3 and apoptotic pathways by betaine attenuates isoproterenol-induced acute myocardial injury in rats.

    Science.gov (United States)

    Zheng, P; Liu, J; Mai, S; Yuan, Y; Wang, Y; Dai, G

    2015-05-01

    The present study was designed to investigate the cardioprotective effects of betaine on acute myocardial ischemia induced experimentally in rats focusing on regulation of signal transducer and activator of transcription 3 (STAT3) and apoptotic pathways as the potential mechanism underlying the drug effect. Male Sprague Dawley rats were treated with betaine (100, 200, and 400 mg/kg) orally for 40 days. Acute myocardial ischemic injury was induced in rats by subcutaneous injection of isoproterenol (85 mg/kg), for two consecutive days. Serum cardiac marker enzyme, histopathological variables and expression of protein levels were analyzed. Oral administration of betaine (200 and 400 mg/kg) significantly reduced the level of cardiac marker enzyme in the serum and prevented left ventricular remodeling. Western blot analysis showed that isoproterenol-induced phosphorylation of STAT3 was maintained or further enhanced by betaine treatment in myocardium. Furthermore, betaine (200 and 400 mg/kg) treatment increased the ventricular expression of Bcl-2 and reduced the level of Bax, therefore causing a significant increase in the ratio of Bcl-2/Bax. The protective role of betaine on myocardial damage was further confirmed by histopathological examination. In summary, our results showed that betaine pretreatment attenuated isoproterenol-induced acute myocardial ischemia via the regulation of STAT3 and apoptotic pathways.

  16. Non-apoptotic function of apoptotic proteins in the development of Malpighian tubules of Drosophila melanogaster

    Indian Academy of Sciences (India)

    Madhu G Tapadia; Naveen K Gautam

    2011-08-01

    Drosophila metamorphosis is characterized by the histolysis of larval structures by programmed cell death, which paves the way for the establishment of adult-specific structures under the influence of the steroid hormone ecdysone. Malpighian tubules function as an excretory system and are one of the larval structures that are not destroyed during metamorphosis and are carried over to adulthood. The pupal Malpighian tubules evade destruction in spite of expressing apoptotic proteins, Reaper, Hid, Grim, Dronc and Drice. Here we show that in the Malpighian tubules expression of apoptotic proteins commences right from embryonic development and continues throughout the larval stages. Overexpression of these proteins in the Malpighian tubules causes larval lethality resulting in malformed tubules. The number and regular organization of principal and stellate cells of Malpighian tubules is disturbed, in turn disrupting the physiological functioning of the tubules as well. Strikingly, the localization of -tubulin, F-actin and Disclarge (Dlg) is also disrupted. These results suggest that the apoptotic proteins could be having non-apoptotic function in the development of Malpighian tubules.

  17. Hearing loss and cochlear damage in experimental pneumococcal meningitis, with special reference to the role of neutrophil granulytes

    DEFF Research Database (Denmark)

    Brandt, CT; Caye-Thomsen, P; Lund, SP;

    2006-01-01

    Hearing loss is a well-known sequelae from meningitis, affecting up to 25% of survivors. However, the principal components of the infectious and inflammatory reaction responsible for the sensorineural hearing loss remain to be identified. The present study aimed to investigate the impact...... of an augmented neutrophil response on the development of hearing loss and cochlear damage in a model of experimental pneumococcal meningitis in rats. Hearing loss and cochlear damage were assessed by distortion product oto-acoustic emissions (DPOAE), auditory brainstem response (ABR) and histopathology in rats...... infection. Pretreatment with G-CSF increased hearing loss 24 h after infection and on day 8 compared to untreated rats (Mann-Whitney, P = 0.012 and P = 0.013 respectively). The increased sensorineural hearing loss at day 8 was associated with significantly decreased spiral ganglion cell counts (P = 0...

  18. Diminution of Oxidative Damage to Human Erythrocytes and Lymphocytes by Creatine: Possible Role of Creatine in Blood.

    Directory of Open Access Journals (Sweden)

    Neha Qasim

    Full Text Available Creatine (Cr is naturally produced in the body and stored in muscles where it is involved in energy generation. It is widely used, especially by athletes, as a staple supplement for improving physical performance. Recent reports have shown that Cr displays antioxidant activity which could explain its beneficial cellular effects. We have evaluated the ability of Cr to protect human erythrocytes and lymphocytes against oxidative damage. Erythrocytes were challenged with model oxidants, 2, 2'-azobis(2-amidinopropane dihydrochloride (AAPH and hydrogen peroxide (H2O2 in the presence and absence of Cr. Incubation of erythrocytes with oxidant alone increased hemolysis, methemoglobin levels, lipid peroxidation and protein carbonyl content. This was accompanied by decrease in glutathione levels. Antioxidant enzymes and antioxidant power of the cell were compromised while the activity of membrane bound enzyme was lowered. This suggests induction of oxidative stress in erythrocytes by AAPH and H2O2. However, Cr protected the erythrocytes by ameliorating the AAPH and H2O2 induced changes in these parameters. This protective effect was confirmed by electron microscopic analysis which showed that oxidant-induced cell damage was attenuated by Cr. No cellular alterations were induced by Cr alone even at 20 mM, the highest concentration used. Creatinine, a by-product of Cr metabolism, was also shown to exert protective effects, although it was slightly less effective than Cr. Human lymphocytes were similarly treated with H2O2 in absence and presence of different concentrations of Cr. Lymphocytes incubated with oxidant alone had alterations in various biochemical and antioxidant parameters including decrease in cell viability and induction of DNA damage. The presence of Cr attenuated all these H2O2-induced changes in lymphocytes. Thus, Cr can function as a blood antioxidant, protecting cells from oxidative damage, genotoxicity and can potentially increase their

  19. Role of inter-hemispheric transfer in generating visual evoked potentials in V1-damaged brain hemispheres.

    Science.gov (United States)

    Kavcic, Voyko; Triplett, Regina L; Das, Anasuya; Martin, Tim; Huxlin, Krystel R

    2015-02-01

    Partial cortical blindness is a visual deficit caused by unilateral damage to the primary visual cortex, a condition previously considered beyond hopes of rehabilitation. However, recent data demonstrate that patients may recover both simple and global motion discrimination following intensive training in their blind field. The present experiments characterized motion-induced neural activity of cortically blind (CB) subjects prior to the onset of visual rehabilitation. This was done to provide information about visual processing capabilities available to mediate training-induced visual improvements. Visual Evoked Potentials (VEPs) were recorded from two experimental groups consisting of 9 CB subjects and 9 age-matched, visually-intact controls. VEPs were collected following lateralized stimulus presentation to each of the 4 visual field quadrants. VEP waveforms were examined for both stimulus-onset (SO) and motion-onset (MO) related components in postero-lateral electrodes. While stimulus presentation to intact regions of the visual field elicited normal SO-P1, SO-N1, SO-P2 and MO-N2 amplitudes and latencies in contralateral brain regions of CB subjects, these components were not observed contralateral to stimulus presentation in blind quadrants of the visual field. In damaged brain hemispheres, SO-VEPs were only recorded following stimulus presentation to intact visual field quadrants, via inter-hemispheric transfer. MO-VEPs were only recorded from damaged left brain hemispheres, possibly reflecting a native left/right asymmetry in inter-hemispheric connections. The present findings suggest that damaged brain hemispheres contain areas capable of responding to visual stimulation. However, in the absence of training or rehabilitation, these areas only generate detectable VEPs in response to stimulation of the intact hemifield of vision.

  20. Cocaine Causes Apoptotic Death in Rat Mesencephalon and Striatum Primary Cultures.

    Science.gov (United States)

    Lepsch, Lucilia B; Planeta, Cleopatra S; Scavone, Critoforo

    2015-01-01

    To study cocaine's toxic effects in vitro, we have used primary mesencephalic and striatal cultures from rat embryonic brain. Treatment with cocaine causes a dramatic increase in DNA fragmentation in both primary cultures. The toxicity induced by cocaine was paralleled with a concomitant decrease in the microtubule associated protein 2 (MAP2) and/or neuronal nucleus protein (NeuN) staining. We also observed in both cultures that the cell death caused by cocaine was induced by an apoptotic mechanism, confirmed by TUNEL assay. Therefore, the present paper shows that cocaine causes apoptotic cell death and inhibition of the neurite prolongation in striatal and mesencephalic cell culture. These data suggest that if similar neuronal damage could be produced in the developing human brain, it could account for the qualitative or quantitative defects in neuronal pathways that cause a major handicap in brain function following prenatal exposure to cocaine.

  1. Cocaine Causes Apoptotic Death in Rat Mesencephalon and Striatum Primary Cultures

    Directory of Open Access Journals (Sweden)

    Lucilia B. Lepsch

    2015-01-01

    Full Text Available To study cocaine’s toxic effects in vitro, we have used primary mesencephalic and striatal cultures from rat embryonic brain. Treatment with cocaine causes a dramatic increase in DNA fragmentation in both primary cultures. The toxicity induced by cocaine was paralleled with a concomitant decrease in the microtubule associated protein 2 (MAP2 and/or neuronal nucleus protein (NeuN staining. We also observed in both cultures that the cell death caused by cocaine was induced by an apoptotic mechanism, confirmed by TUNEL assay. Therefore, the present paper shows that cocaine causes apoptotic cell death and inhibition of the neurite prolongation in striatal and mesencephalic cell culture. These data suggest that if similar neuronal damage could be produced in the developing human brain, it could account for the qualitative or quantitative defects in neuronal pathways that cause a major handicap in brain function following prenatal exposure to cocaine.

  2. Nucleo-cytoplasmic communication in apoptotic response to genotoxic and inflammatory stress

    Institute of Scientific and Technical Information of China (English)

    Jean Y. J. WANG

    2005-01-01

    Genotoxic agents or inflammatory cytokines activate cellular stress responses and trigger programmed cell death.We have identified a signal transduction module, including three nuclear proteins that participate in the regulation of cell death induced by chemotherapeutic agents and tumor necrosis factor (TNF). In this nuclear signaling module, retinoblastoma protein (Rb) functions as an inhibitor of apoptotic signal transduction. Inactivation of Rb by phosphorylation or caspase-dependent cleavage/degradation is required for cell death to occur. Rb inhibits the Abl tyrosine kinase. Thus,Rb inactivation is a pre-requisite for Abl activation by DNA damage or TNF. Activation of nuclear Abl and its downstream effector p73 induces mitochondriadependent cell death. The involvement of these nuclear signal transducers in TNF induced apoptosis, which does not require new gene expression, indicates that nuclear events other than transcription can contribute to extrinsic apoptotic signal transduction.

  3. Protective role of diallyl tetrasulfide on cadmium-induced testicular damage in adult rats: a biochemical and histological study.

    Science.gov (United States)

    Ponnusamy, Murugavel; Pari, Leelavinothan

    2011-06-01

    Cadmium (Cd)-induced oxidative damage is the most serious problem that leads to reproductive system failure in both human and animals. Our previous studies indicate that diallyl tetrasulfide (DTS) from garlic has the cytoprotective and antioxidant activity against Cd-induced toxicity in vivo and in vitro. The present investigation was carried out to find the influence of DTS on peroxidative damage induced by Cd in rat testes. The Cd-exposed rat testis showed a significant (p glutathione peroxidase) and glutathione metabolizing (glutathione-S-transferase, glutathione reductase and glucose-6-phosphate dehydrogenase) enzymes as well as reduced levels of non-enzymic (reduced glutathione, ascorbate and total sulphydryl groups) antioxidants. In contrast, treatment with DTS (40 mg/kg body weight orally) significantly (p Testicular protection by DTS is further substantiated by remarkable reduction of Cd-induced pathological changes. Our study has revealed that DTS renders protection against Cd-induced testicular injury by reducing Cd-mediated oxidative damage.

  4. BAD-mediated apoptotic pathway is associated with human cancer development.

    Science.gov (United States)

    Stickles, Xiaomang B; Marchion, Douglas C; Bicaku, Elona; Al Sawah, Entidhar; Abbasi, Forough; Xiong, Yin; Bou Zgheib, Nadim; Boac, Bernadette M; Orr, Brian C; Judson, Patricia L; Berry, Amy; Hakam, Ardeshir; Wenham, Robert M; Apte, Sachin M; Berglund, Anders E; Lancaster, Johnathan M

    2015-04-01

    The malignant transformation of normal cells is caused in part by aberrant gene expression disrupting the regulation of cell proliferation, apoptosis, senescence and DNA repair. Evidence suggests that the Bcl-2 antagonist of cell death (BAD)-mediated apoptotic pathway influences cancer chemoresistance. In the present study, we explored the role of the BAD-mediated apoptotic pathway in the development and progression of cancer. Using principal component analysis to derive a numeric score representing pathway expression, we evaluated clinico-genomic datasets (n=427) from corresponding normal, pre-invasive and invasive cancers of different types, such as ovarian, endometrial, breast and colon cancers in order to determine the associations between the BAD-mediated apoptotic pathway and cancer development. Immunofluorescence was used to compare the expression levels of phosphorylated BAD [pBAD (serine-112, -136 and -155)] in immortalized normal and invasive ovarian, colon and breast cancer cells. The expression of the BAD-mediated apoptotic pathway phosphatase, PP2C, was evaluated by RT-qPCR in the normal and ovarian cancer tissue samples. The growth-promoting effects of pBAD protein levels in the immortalized normal and cancer cells were assessed using siRNA depletion experiments with MTS assays. The expression of the BAD-mediated apoptotic pathway was associated with the development and/or progression of ovarian (n=106, pcancers, as well as with ovarian endometriosis (n=20, pcancer cells compared to the immortalized normal cells, whereas PP2C gene expression was lower in the cancer compared to the ovarian tumor tissue samples (n=76, pcancer cells. The BAD-mediated apoptotic pathway is thus associated with the development of human cancers likely influenced by the protein levels of pBAD.

  5. Boolean model of Yeast Apoptosis as a tool to study yeast and human apoptotic regulations

    Directory of Open Access Journals (Sweden)

    Laleh eKazemzadeh

    2012-12-01

    Full Text Available Programmed cell death (PCD is an essential cellular mechanism that is evolutionary conserved, mediated through various pathways and acts by integrating different stimuli. Many diseases such as neurodegenerative diseases and cancers are found to be caused by, or associated with, regulations in the cell death pathways. Yeast Saccharomyces cerevisiae, is a unicellular eukaryotic organism that shares with human cells components and pathways of the PCD and is therefore used as a model organism. Boolean modelling is becoming promising approach to capture qualitative behaviour and describe essential properties of such complex networks. Here we present large literature-based and to our knowledge first Boolean model that combines pathways leading to apoptosis (a type of PCD in yeast. Analysis of the yeast model confirmed experimental findings of anti-apoptotic role of Bir1p and pro-apoptotic role of Stm1p and revealed activation of the stress protein kinase Hog proposing the maximal level of activation upon heat stress. In addition we extended the yeast model and created an in silico humanized yeast in which human pro- and anti-apoptotic regulators Bcl-2 family and Valosin-contain protein (VCP are included in the model. We showed that accumulation of Bax in in silico humanized yeast shows apoptotic markers and that VCP is essential target of Akt Signaling. The presented Boolean model provides comprehensive description of yeast apoptosis network behaviour. Extended model of humanized yeast gives new insights of how complex human disease like neurodegenration can initially be tested.

  6. Regulation of MAP kinase-dependent apoptotic pathway: implication of reactive oxygen and nitrogen species.

    Science.gov (United States)

    Sumbayev, Vadim V; Yasinska, Inna M

    2005-04-15

    Mitogen-activated protein (MAP) kinase signaling cascades are multi-functional signaling networks that influence cell growth, differentiation, apoptosis, and cellular responses to stress. Apoptosis signal-regulating kinase 1 (ASK1) is a MAP kinase kinase kinase that triggers apoptogenic kinase cascade leading to the phosphorylation/activation of c-Jun N-terminal kinases and p38-MAP kinase, which are responsible for inducing apoptotic cell death. This pathway plays a pivotal role in transduction of signals from different apoptotic stimuli. In the present review, we summarized the recent evidence concerning MAP kinase-dependent apoptotic pathway and its regulation in the mammalian cells and organism in vivo. We have shown that the key messengers of regulation of this pathway are the reactive oxygen and nitrogen species. The role of protein oxidation and S-nitrosation in induction of apoptotic cell death via ASK1 is discussed. Also we have outlined other recently discovered signal transduction processes involved in the regulation of ASK1 activity and downstream pathway.

  7. Modulation of Apoptotic Signaling by the Hepatitis B Virus X Protein

    Directory of Open Access Journals (Sweden)

    Michael J. Bouchard

    2012-11-01

    Full Text Available Worldwide, an estimated 350 million people are chronically infected with the Hepatitis B Virus (HBV; chronic infection with HBV is associated with the development of severe liver diseases including hepatitis and cirrhosis. Individuals who are chronically infected with HBV also have a significantly higher risk of developing hepatocellular carcinoma (HCC than uninfected individuals. The HBV X protein (HBx is a key regulatory HBV protein that is important for HBV replication, and likely plays a cofactor role in the development of HCC in chronically HBV-infected individuals. Although some of the functions of HBx that may contribute to the development of HCC have been characterized, many HBx activities, and their putative roles during the development of HBV-associated HCC, remain incompletely understood. HBx is a multifunctional protein that localizes to the cytoplasm, nucleus, and mitochondria of HBV‑infected hepatocytes. HBx regulates numerous cellular signal transduction pathways and transcription factors as well as cell cycle progression and apoptosis. In this review, we will summarize reports in which the impact of HBx expression on cellular apoptotic pathways has been analyzed. Although various effects of HBx on apoptotic pathways have been observed in different model systems, studies of HBx activities in biologically relevant hepatocyte systems have begun to clarify apoptotic effects of HBx and suggest mechanisms that could link HBx modulation of apoptotic pathways to the development of HBV-associated HCC.

  8. Boolean Model of Yeast Apoptosis as a Tool to Study Yeast and Human Apoptotic Regulations

    Science.gov (United States)

    Kazemzadeh, Laleh; Cvijovic, Marija; Petranovic, Dina

    2012-01-01

    Programmed cell death (PCD) is an essential cellular mechanism that is evolutionary conserved, mediated through various pathways and acts by integrating different stimuli. Many diseases such as neurodegenerative diseases and cancers are found to be caused by, or associated with, regulations in the cell death pathways. Yeast Saccharomyces cerevisiae, is a unicellular eukaryotic organism that shares with human cells components and pathways of the PCD and is therefore used as a model organism. Boolean modeling is becoming promising approach to capture qualitative behavior and describe essential properties of such complex networks. Here we present large literature-based and to our knowledge first Boolean model that combines pathways leading to apoptosis (a type of PCD) in yeast. Analysis of the yeast model confirmed experimental findings of anti-apoptotic role of Bir1p and pro-apoptotic role of Stm1p and revealed activation of the stress protein kinase Hog proposing the maximal level of activation upon heat stress. In addition we extended the yeast model and created an in silico humanized yeast in which human pro- and anti-apoptotic regulators Bcl-2 family and Valosin-contain protein (VCP) are included in the model. We showed that accumulation of Bax in silico humanized yeast shows apoptotic markers and that VCP is essential target of Akt Signaling. The presented Boolean model provides comprehensive description of yeast apoptosis network behavior. Extended model of humanized yeast gives new insights of how complex human disease like neurodegeneration can initially be tested. PMID:23233838

  9. Apoptotic cell clearance: basic biology and therapeutic potential.

    Science.gov (United States)

    Poon, Ivan K H; Lucas, Christopher D; Rossi, Adriano G; Ravichandran, Kodi S

    2014-03-01

    The prompt removal of apoptotic cells by phagocytes is important for maintaining tissue homeostasis. The molecular and cellular events that underpin apoptotic cell recognition and uptake, and the subsequent biological responses, are increasingly better defined. The detection and disposal of apoptotic cells generally promote an anti-inflammatory response at the tissue level, as well as immunological tolerance. Consequently, defects in apoptotic cell clearance have been linked with various inflammatory diseases and autoimmunity. Conversely, under certain conditions, such as the killing of tumour cells by specific cell-death inducers, the recognition of apoptotic tumour cells can promote an immunogenic response and antitumour immunity. Here, we review the current understanding of the complex process of apoptotic cell clearance in physiology and pathology, and discuss how this knowledge could be harnessed for new therapeutic strategies.

  10. Evaluation of anti-apoptotic activity of different dietary antioxidants in renal cell carcinoma against hydrogen peroxide

    Institute of Scientific and Technical Information of China (English)

    Garg Neeraj K; Mangal Sharad; Sahu Tejram; Mehta Abhinav; Vyas Suresh P; Tyagi Rajeev K

    2011-01-01

    Objective: To evaluate the anti-apoptotic and radical scavenging activities of dietary phenolics, namely ascorbic acid, -tocopherol acetate, citric acid, salicylic acid, and estimate H2O2-induced apoptosis in renal cell carcinoma cells. Methods: The intracellular antioxidant potency of antioxidants was investigated. H2O2-induced apoptosis in RCC-26 was assayed with the following parameters: cell viability (% apoptosis), nucleosomal damage and DNA fragmentation, bcl-2 levels and flow cytometery analysis (ROS production evaluation). Results: The anticancer properties of antioxidants such as ascorbic acid, - tocopherol acetate, citric acid, salicylic acid with perdurable responses were investigated. It was observed that these antioxidants had protective effect (anti-apoptotic activity) against hydrogen peroxide (H2O2) in renal cell carcinoma (RCC-26) cell line. Conclusions: This study reveals and proves the anticancer properties. However, in cancer cell lines anti-apoptotic activity can indirectly reflect the cancer promoter activity through radicals scavenging, and significantly protect nucleus and bcl-2.

  11. Effect of ethanol on pro-apoptotic mechanisms in polarized hepatic cells

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Chronic ethanol consumption is associated with serious and potentially fatal alcohol-related liver injuries such as hepatomegaly, alcoholic hepatitis and cirrhosis. Moreover,it has been documented that the clinical progression of alcohol-induced liver damage may be associated with an increase in hepatocellular death that involves apoptotic mechanisms. Although much information has been learned about the clinical manifestations associated with alcohol-related diseases, the search continues for a better understanding of the molecular and/or cellular mechanisms by which ethanol exerts its deleterious effects such as the induction of pro-apoptotic mechanisms and related cell damaging events. As part of the effort to enhance our understanding of those particular cellular pathways and mechanisms associated with ethanol toxicity, researchers over the years have utilized a variety of model systems. Recently, work has come forth demonstrating the utility of a hybrid cell line (WIF-B) as a cell culture model system for the study of alcohol-associated alterations in hepatocellular mechanisms. Success with such emerging model systems could aid in the development of potential therapeutic treatments for the prevention of alcoholinduced apoptotic cell death that may ultimately serve as a significant target in delaying the onset and/or progression of clinical symptoms of alcohol-mediated liver disease. This review article summarizes the current understanding of ethanol-mediated modifications in cell survival and thus the promotion of pro-apoptotic events with emphasis on analyses made in various experimental model systems, particularly the more recently characterized WIF-B cell system.

  12. Genotoxic and apoptotic effects of Goeckerman therapy for psoriasis

    Energy Technology Data Exchange (ETDEWEB)

    Borska, L.; Andrys, C.; Krejsek, J.; Hamakova, K.; Kremlacek, J.; Palicka, V.; Ranna, D.; Fiala, Z. [Charles University Prague, Prague (Czech Republic). Faculty of Medicine

    2010-03-15

    Goeckerman therapy (GT) for psoriasis is based on cutaneous application of crude coal tar (polycyclic aromatic hydrocarbons (PAH)) and exposure to ultraviolet radiation (UVR). PAH and UVR are mutagenic, carcinogenic and immunotoxic agents that promote apoptosis. We evaluated dermal absorption of PAH as well as the genotoxic and apoptotic effects of GT in 20 patients with psoriasis, by determining numbers of chromosomal abnormalities in peripheral lymphocytes, and levels of 1-hydroxypyrene (1-OHP), p53 protein and soluble FasL (sFasL) in urine and/or blood, before and after GT. Psoriasis Area and Severity Index (PASI) score was used to evaluate clinical efficacy of GT. Compared with pre-treatment levels, there was a significant increase in urine 1-OHP, indicating a high degree of dermal absorption of PAH (P <0.01). We also found a significant increase in the number of chromosomal abnormalities in peripheral blood lymphocytes (P <0.001), suggesting that GT is genotoxic; significantly increased p53 protein in plasma (P <0.05), an indicator of cell response to DNA damage; and significantly increased sFasL in serum (P <0.01), an indicator of apoptosis. The PASI score was significantly decreased after GT (P <0.001), confirming clinical benefit of this treatment. Our results demonstrate high dermal absorption of PAH during GT and provide evidence that GT promotes genotoxicity and apoptosis.

  13. Cytoprotective roles of GSH, SOD and solcoseryl against ischemic damage and reperfusion injury to warm ischemic lung. Study of Canine warm ischemic lung.

    OpenAIRE

    Taniguchi, Hideki; Kawahara, Katsunobu; Nakasone, Tomonori; Ikari, Hideki; Honjoh, Seiji; Hisano, Hiroshi; Takahashi, Takao; Kusano, Hiroyuki; Ayabe, Hiroyoshi; Tomita, Masao

    1990-01-01

    This study was performed to clarify the roles of reduced glutathion (GSH), superoxide dismutase (SOD), and solcosaryl in ischemic damage and reperfusion injury to the warm ischemic lungs of experimental animals. Fifty-one warm ischemic canine lungs were made by hilar stripping and clamping of the left PA, PV and bronchus for 2-3 hours. In the Non-perfusion group, GSH (50mg/ kg, I. V.: Group II) and solcoseryl (50mg/kg, I. V.: Group III) were administered. In the perfusion group, Euro-Collins ...

  14. Role of hazelnut consumption on DNA damage and lipid-related markers in children with primary dyslipidemia

    Directory of Open Access Journals (Sweden)

    Cristian Del Bo'

    2015-06-01

    Sixty children (11.5 ± 2.5 years have participated in an 8-week controlled, parallel, dietary intervention study with hazelnuts (0.43 g/kg body weight per day. Subjects received dietary guidelines and were randomized in 3 groups: 1- hazelnuts with skin; 2- hazelnut without skin; 3- control (without hazelnuts. Before and after intervention, blood samples were collected and used to evaluate the levels of formamidopyrimidine-DNA glycosylase (FPG-sensitive sites and H2O2-induced DNA damage in peripheral blood mononuclear cells (by comet assay, serum lipid profile (by automatic analyzer and erythrocyte membrane phospholipids composition (by gas chromatography analysis. Preliminary results in a subgroup (5 subjects receiving hazelnut with skin and 5 controls show a reduction in the FPG-sensitive sites (from 13.8 ± 3.16% to 7.88 ± 2.98% and H2O2-induced DNA damage (from 44.4 ± 3.1% to 35.7 ± 7.6% following 8-week hazelnut consumption, while no effect seems to occur in the control group. Hazelnut decreases serum LDL-C level (-11.2%; p= 0.01 and seems to affect erythrocyte membrane phospholipids composition compared to baseline, while no difference in triglycerides, total and HDL-C levels has been documented in the subgroup analyzed. These preliminary results show a tendency towards a decrease in the levels of FPG-sensitive sites, H2O2-induced DNA damage and serum LDL-C after an 8-week hazelnut intervention. Data elaboration on the complete group of subjects will help understanding the effect of hazelnut consumption on lipid profile and markers of oxidative stress in children affected by primary dyslipidemia.

  15. Gene deletion of glutathione S-transferase theta: correlation with induced genetic damage and potential role in endogenous mutagenesis.

    Science.gov (United States)

    Wiencke, J K; Pemble, S; Ketterer, B; Kelsey, K T

    1995-01-01

    Genetic traits that confer increased susceptibility to DNA and chromosomal damage from reactive epoxide and peroxides could be important individual risk factors in the development of human cancers. To provide an index of individual sensitivity to expoxides, we previously studied sister chromatid exchange (SCE) induction in peripheral blood lymphocytes and identified a trait involving sensitivity to chromosomal damage by monoepoxybutene and diepoxybutane (DEB), both potential carcinogenic metabolites of 1,3-butadiene. Individuals sensitive to DEB induction of SCEs also had an increased number of background or "spontaneous" SCEs. The present investigation was conducted to test whether a newly described deletion polymorphism in the glutathione S-transferase class theta (GSTT1) was significantly associated with the previously described inherited chromosomal sensitivity to DEB. The background and DEB-induced SCE frequencies in peripheral blood lymphocytes from 78 healthy volunteers were determined with the use of fluorescence plus Giemsa staining. The presence or absence of the homozygous deletion of the GSTT1 gene was determined for each participant using PCR methods. In the present study, we report a close correlation of the DEB sensitivity trait with the novel polymorphism in GSTT1. The GSTT1 polymorphism was also highly associated with the background frequencies of SCE. These studies raise the possibility that DBE is a substrate for GST-theta. Individuals who carry a homozygous deletion of the GSTT1 gene may be at increased risk for genotoxic damage from environmental or occupational 1,3-butadiene exposures. The association of the GSTT1 deletion polymorphism with increases in background SCEs indicates that substrates for this isozyme are encountered commonly in the environment or are endogenous in nature.(ABSTRACT TRUNCATED AT 250 WORDS)

  16. Modulating effect of SIRT1 activation induced by resveratrol on Foxo1-associated apoptotic signalling in senescent heart.

    Science.gov (United States)

    Sin, Thomas K; Yu, Angus P; Yung, Benjamin Y; Yip, Shea Ping; Chan, Lawrence W; Wong, Cesar S; Ying, Michael; Rudd, John A; Siu, Parco M

    2014-06-15

    Elevations of cardiomyocyte apoptosis and fibrotic deposition are major characteristics of the ageing heart. Resveratrol, a polyphenol in grapes and red wine, is known to improve insulin resistance and increase mitochondrial biogenesis through the SIRT1-PGC-1α signalling axis. Recent studies attempted to relate SIRT1 activation by resveratrol to the regulation of apoptosis in various disease models of cardiac muscle. In the present study, we tested the hypothesis that long-term (8-month) treatment of resveratrol would activate SIRT1 and improve the cardiac function of senescent mice through suppression of Foxo1-associated pro-apoptotic signalling. Our echocardiographic measurements indicated that the cardiac systolic function measured as fractional shortening and ejection fraction was significantly reduced in aged mice when compared with the young mice. These reductions, however, were not observed in resveratrol-treated hearts. Ageing significantly reduced the deacetylase activity, but not the protein abundance of SIRT1 in the heart. This reduction was accompanied by increased acetylation of the Foxo1 transcription factor and transactivation of its target, pro-apoptotic Bim. Subsequent analyses indicated that pro-apoptotic signalling measured as p53, Bax and apoptotic DNA fragmentation was up-regulated in the heart of aged mice. In contrast, resveratrol restored SIRT1 activity and suppressed elevations of Foxo1 acetylation, Bim and pro-apoptotic signalling in the aged heart. In parallel, resveratrol also attenuated the ageing-induced elevations of fibrotic collagen deposition and markers of oxidative damage including 4HNE and nitrotyrosine. In conclusion, these novel data demonstrate that resveratrol mitigates pro-apoptotic signalling in senescent heart through a deacetylation mechanism of SIRT1 that represses the Foxo1-Bim-associated pro-apoptotic signalling axis.

  17. Anti-apoptotic signaling as a cytoprotective mechanism in mammalian hibernation

    Directory of Open Access Journals (Sweden)

    Andrew N. Rouble

    2013-02-01

    Full Text Available In the context of normal cell turnover, apoptosis is a natural phenomenon involved in making essential life and death decisions. Apoptotic pathways balance signals which promote cell death (pro-apoptotic pathways or counteract these signals (anti-apoptotic pathways. We proposed that changes in anti-apoptotic proteins would occur during mammalian hibernation to aid cell preservation during prolonged torpor under cellular conditions that are highly injurious to most mammals (e.g. low body temperatures, ischemia. Immunoblotting was used to analyze the expression of proteins associated with pro-survival in six tissues of thirteen-lined ground squirrels, Ictidomys tridecemlineatus. The brain showed a concerted response to torpor with significant increases in the levels of all anti-apoptotic targets analyzed (Bcl-2, Bcl-xL, BI-1, Mcl-1, cIAP1/2, xIAP as well as enhanced phosphorylation of Bcl-2 at S70 and T56. Heart responded similarly with most anti-apoptotic proteins elevated significantly during torpor except for Bcl-xL and xIAP that decreased and Mcl-1 that was unaltered. In liver, BI-1 increased whereas cIAP1/2 decreased. In kidney, there was an increase in BI-1, cIAP and xIAP but decreases in Bcl-xL and p-Bcl-2(T56 content. In brown adipose tissue, protein levels of BI-1, cIAP1/2, and xIAP decreased significantly during torpor (compared with euthermia whereas Bcl-2, Bcl-xL, Mcl-1 were unaltered; however, Bcl-2 showed enhanced phosphorylation at Thr56 but not at Ser70. In skeletal muscle, only xIAP levels changed significantly during torpor (an increase. The data show that anti-apoptotic pathways have organ-specific responses in hibernators with a prominent potential role in heart and brain where coordinated enhancement of anti-apoptotic proteins occurred in response to torpor.

  18. Defense mechanisms against radiation induced teratogenic damage in mice

    Energy Technology Data Exchange (ETDEWEB)

    Kato, F.; Ootsuyama, A.; Nomoto, S.; Norimura, T. [Univ. of Occupational and Environmental Health, Kitakyushu, (Japan)

    2002-07-01

    Experimental studies with mice have established that fetuses at midgestational stage are highly susceptible to malformation at high, but not low, doses of radiation. When DNA damage is produced by a small amount of radiation, it is efficiently eliminated by DNA repair. However, DNA repair is not perfect. There must be defense mechanisms other than DNA repair. In order to elucidate the essential role of p53 gene in apoptotic tissue repair, we compared the incidence of radiation-induced malformations and deaths (deaths after day 10) in wild-type p53 (+/+) mice and null p53 (-/-) mice. For p53 (+/+) mice, an X-ray dose of 2 Gy given at a high dose-rate (450 mGy/min) to fetuses at 9.5 days of gestation was highly lethal and considerably teratogenic whereas it was only slightly lethal but highly teratogenic for p53 (-/-) fetuses. This reciprocal relationship of radiosensitivity to malformations and deaths supports the notion that fetal tissues have a p53 -dependent idguardianln of the tissue that aborts cells bearing radiation-induced teratogenic DNA damage. When an equal dose of 2 Gy given at a 400-fold lower dose-rate (1.2 mGy/min), this dose became not teratogenic for p53 (+/+) fetuses exhibiting p53 -dependent apoptosis, whereas this dose remained teratogenic for p53 (-/-) fetuses unable to carry out apoptosis. Furthermore, when the dose was divided into two equal dose fractions (1+1 Gy) at high dose rate, separated by 24 hours, the incidences of malformations were equal with control level for p53 (+/+), but higher for p53 (-/-) mice. Hence, complete elimination of teratogenic damage from irradiated tissues requires a concerted cooperation of two mechanisms; proficient DNA repair and p53-dependent apoptotic tissue repair.

  19. DNA damage in hemodialysis patients with chronic kidney disease; a test of the role of diabetes mellitus; a comet assay investigation.

    Science.gov (United States)

    Mamur, Sevcan; Unal, Fatma; Altok, Kadriye; Deger, Serpil Muge; Yuzbasioglu, Deniz

    2016-04-01

    The incidence of chronic kidney disease (CKD) is increasing rapidly. Diabetes mellitus (DM) is the most important cause of CKD. We studied the possible role of DM in CKD patients with respect to DNA damage, as assessed by the comet assay in 60 CKD patients (with or without DM) undergoing hemodialysis and in 26 controls. Effects of other factors, such as age, sex, hypertension, duration of hemodialysis, body mass index (BMI), and levels of hemoglobin (HB), intact parathormone (iPTH), and ferritin (FER), were also examined. Primary DNA damage measured by the comet assay was significantly higher in CKD patients than in controls. Among CKD patients, the following correlations were observed. (1) There was no difference in comet tail length or tail intensity between diabetic and non-diabetic individuals. (2) Age, sex, hemoglobin, hypertension, duration of hemodialysis, and ferritin levels affected neither tail length nor intensity. (3) BMI values above 25kg/m(2) and iPTH levels above 300pg/ml were associated with significantly greater comet tail length. Our results indicate that primary DNA damage is increased in CKD patients undergoing hemodialysis, compared to controls; however, DM had no additional effect.

  20. Role of the Renin-Angiotensin-Aldosterone System beyond Blood Pressure Regulation: Molecular and Cellular Mechanisms Involved in End-Organ Damage during Arterial Hypertension.

    Science.gov (United States)

    Muñoz-Durango, Natalia; Fuentes, Cristóbal A; Castillo, Andrés E; González-Gómez, Luis Martín; Vecchiola, Andrea; Fardella, Carlos E; Kalergis, Alexis M

    2016-06-23

    Arterial hypertension is a common condition worldwide and an important predictor of several complicated diseases. Arterial hypertension can be triggered by many factors, including physiological, genetic, and lifestyle causes. Specifically, molecules of the renin-angiotensin-aldosterone system not only play important roles in the control of blood pressure, but they are also associated with the genesis of arterial hypertension, thus constituting a need for pharmacological interventions. Chronic high pressure generates mechanical damage along the vascular system, heart, and kidneys, which are the principal organs affected in this condition. In addition to mechanical stress, hypertension-induced oxidative stress, chronic inflammation, and the activation of reparative mechanisms lead to end-organ damage, mainly due to fibrosis. Clinical trials have demonstrated that renin-angiotensin-aldosterone system intervention in hypertensive patients lowers morbidity/mortality and inflammatory marker levels as compared to placebo patients, evidencing that this system controls more than blood pressure. This review emphasizes the detrimental effects that a renin-angiotensin-aldosterone system (RAAS) imbalance has on health considerations above and beyond high blood pressure, such as fibrotic end-organ damage.

  1. Surface Characterizations of Fretting Fatigue Damage in Aluminum Alloy 7075-T6 Clamped Joints: The Beneficial Role of Ni–P Coatings

    Directory of Open Access Journals (Sweden)

    Reza H. Oskouei

    2016-02-01

    Full Text Available This paper aims to characterize the surface damage as a consequence of fretting fatigue in aluminum alloy 7075-T6 plates in double-lap bolted joints through XRD, surface profilometry, and SEM analyses. The main focus was on the surface roughness and chemical phase composition of the damaged zone along with the identification of fretting fatigue crack initiations over the surface of the material. The surface roughness of the fretted zone was found to increase when the joint was clamped with a higher tightening torque and tested under the same cyclic loading. Additionally, MgZn2 (η/ή precipitates and ZnO phase were found to form onto the surface of uncoated aluminum plate in the fretted and worn zones. The formation of the ZnO phase was understood to be a result of frictional heat induced between the surface of contacting uncoated Al 7075-T6 plates during cyclic loading and exposure to the air. The beneficial role of electroless nickel-phosphorous (Ni–P coatings in minimizing the fretting damage and thus improving the fretting fatigue life of the aluminum plates was also studied. The results showed that the surface roughness decreased by approximately 40% after applying Ni–P coatings to the Al 7075-T6 plates.

  2. Expression patterns suggest that despite considerable functional redundancy, galectin-4 and -6 play distinct roles in normal and damaged mouse digestive tract.

    Science.gov (United States)

    Houzelstein, Denis; Reyes-Gomez, Edouard; Maurer, Marie; Netter, Pierre; Higuet, Dominique

    2013-05-01

    The galectin-4 protein is mostly expressed in the digestive tract and is associated with lipid raft stabilization, protein apical trafficking, wound healing, and inflammation. While most mammalian species, including humans, have a single Lgals4 gene, some mice have two paralogues: Lgals4 and Lgals6. So far, their significant similarities have hindered the analysis of their respective expression and function. We took advantage of two antibodies that discriminate between the galectin-4 and galectin-6 proteins to document their patterns of expression in the normal and the dextran sodium sulfate (DSS)-damaged digestive tract in the mouse. In the normal digestive tract, their pattern of expression from tongue to colon is quite similar, which suggests functional redundancy. However, the presence of galectin-4, but not galectin-6, in the lamina propria of the DSS-damaged colon, its association with luminal colonic bacteria, and differences in subcellular localization of these proteins suggest that they also have distinct roles in the normal and the damaged mouse digestive tract. Our results provide a rare example of ancestral and derived functions evolving after tandem gene duplication.

  3. Cytotoxic, genotoxic and apoptotic effects of naringenin-oxime relative to naringenin on normal and cancer cell lines

    Institute of Scientific and Technical Information of China (English)

    Abdurrahim Kocyigit; Ismail Koyuncu; Murat Dikilitas; Fatemeh Bahadori; Baki Turkkan

    2016-01-01

    Objective: To assess and compare the cytotoxic, genotoxic, apoptotic and reactive oxygen species (ROS) generating effects of naringenin (NG) and its new derived compound naringenin-oxime (NG-Ox) on MCF-7, HT-29, PC-12 cancer and L-929 normal cell lines. Methods: The cells were incubated with different doses of NG-Ox and NG (50–1 000 mmol/L) for 24 h. The cell viability was assessed based on ATP cell viability assay. Intracellular accumulation of ROS was determined using the fluorescent probes 2070-dichlorodihydrofluorescin diacetate. Genotoxic effects were evaluated by alkaline single cell gel electrophoresis assay (comet assay) and, the apoptotic effect was evaluated by acridine orange staining at below the IC50 levels. Results: Both NG-Ox and NG exhibited cytotoxic, genotoxic and apoptotic effects and resulted in increased ROS values in a dose-dependent manner. The effects were more pronounced on cancer cell lines. The cytotoxic, genotoxic and apoptotic effects of NG-Ox were higher than that of NG in all cell lines. Significant correlations were observed be-tween cell viability, DNA damage, apoptosis and ROS, in all cell lines exposed to either NG-Ox or NG. Conclusions: This study showed that both NG-Ox and NG possess cytotoxic, genotoxic and apoptotic activities through the production of ROS on cells, NG-Ox being the more effective one. Therefore, derived compound of NG might be used as antiproliferative agents for the treatment of cancer.

  4. The regulation of apoptotic cell death

    Directory of Open Access Journals (Sweden)

    G.P. Amarante-Mendes

    1999-09-01

    Full Text Available Apoptosis is a fundamental biological phenomenon in which the death of a cell is genetically and biochemically regulated. Different molecules are involved in the regulation of the apoptotic process. Death receptors, coupled to distinct members of the caspases as well as other adapter molecules, are involved in the initiation of the stress signals (The Indictment. Members of the Bcl-2 family control at the mitochondrial level the decision between life and death (The Judgement. The effector caspases are responsible for all morphological and biochemical changes related to apoptosis including the "eat-me" signals perceived by phagocytes and neighboring cells (The Execution. Finally, apoptosis would have little biological significance without the recognition and removal of the dying cells (The Burial.

  5. The regulation of apoptotic cell death

    Directory of Open Access Journals (Sweden)

    Amarante-Mendes G.P.

    1999-01-01

    Full Text Available Apoptosis is a fundamental biological phenomenon in which the death of a cell is genetically and biochemically regulated. Different molecules are involved in the regulation of the apoptotic process. Death receptors, coupled to distinct members of the caspases as well as other adapter molecules, are involved in the initiation of the stress signals (The Indictment. Members of the Bcl-2 family control at the mitochondrial level the decision between life and death (The Judgement. The effector caspases are responsible for all morphological and biochemical changes related to apoptosis including the "eat-me" signals perceived by phagocytes and neighboring cells (The Execution. Finally, apoptosis would have little biological significance without the recognition and removal of the dying cells (The Burial.

  6. Aspirin protected against endothelial damage induced by LDL:role of endogenous NO synthase inhibitors in rats

    Institute of Scientific and Technical Information of China (English)

    Sheng DENG; Pan-yue DENG; Jun-lin JIANG; Feng YE; Jing YU; Tian-lun YANG; Han-wu DENG; Yuan-jian LI

    2004-01-01

    AIM: To study the protective effect of aspirin on damages of the endothelium induced by low-density lipoprotein (LDL), and whether the protective effect of aspirin is related to reduction of nitric oxide synthase inhibitor level.METHODS: Vascular endothelial injury was induced by a single injection of native LDL (4 mg/kg) in rats. Vasodilator responses to acetylcholine (Ach) in the isolated aortic rings were determined, and serum concentrations of asymmetric dimethylarginine (ADMA), malondialdehyde (MDA), tumour necrosis factor-α(TNF-α), and the activity of dimethylaminohydrolase (DDAH) were measured. RESULTS: A single injection of LDL (4 mg/kg)significantly decreased vasodilator responses to Ach, increased the serum level of ADMA, MDA, and TNF-α, and decreased DDAH activity. Aspirin (30 or 100 mg/kg) markedly reduced the inhibition of vasodilator responses to Ach by LDL, and the protective effect of aspirin at the lower dose was greater compared with high-dose aspirin group. Aspirin inhibited the increased level of MDA and TNF-α induced by LDL. Aspirin at the dose of 30 mg/kg,but not at higher dose (100 mg/kg), significantly reduced the concentration of ADMA and increased the activity of DDAH. CONCLUSION: Aspirin at the lower dose (30 mg/kg) protects the endothelium against damages elicited by LDL in vivo, and the protective effect of aspirin on endothelium is related to reduction of ADMA concentration by increasing DDAH activity.

  7. Innate recognition of apoptotic cells: novel apoptotic cell-associated molecular patterns revealed by crossreactivity of anti-LPS antibodies.

    Science.gov (United States)

    Tennant, I; Pound, J D; Marr, L A; Willems, J J L P; Petrova, S; Ford, C A; Paterson, M; Devitt, A; Gregory, C D

    2013-05-01

    Cells dying by apoptosis are normally cleared by phagocytes through mechanisms that can suppress inflammation and immunity. Molecules of the innate immune system, the pattern recognition receptors (PRRs), are able to interact not only with conserved structures on microbes (pathogen-associated molecular patterns, PAMPs) but also with ligands displayed by apoptotic cells. We reasoned that PRRs might therefore interact with structures on apoptotic cells - apoptotic cell-associated molecular patterns (ACAMPs) - that are analogous to PAMPs. Here we show that certain monoclonal antibodies raised against the prototypic PAMP, lipopolysaccharide (LPS), can crossreact with apoptotic cells. We demonstrate that one such antibody interacts with a constitutively expressed intracellular protein, laminin-binding protein, which translocates to the cell surface during apoptosis and can interact with cells expressing the prototypic PRR, mCD14 as well as with CD14-negative cells. Anti-LPS cross reactive epitopes on apoptotic cells colocalised with annexin V- and C1q-binding sites on vesicular regions of apoptotic cell surfaces and were released associated with apoptotic cell-derived microvesicles (MVs). These results confirm that apoptotic cells and microbes can interact with the immune system through common elements and suggest that anti-PAMP antibodies could be used strategically to characterise novel ACAMPs associated not only with apoptotic cells but also with derived MVs.

  8. Medical Recapitulate%Role of Nrf-2 Gene in the Pathogenesis of Brain Damage Following Acute Carbon Monoxide Poison-ing

    Institute of Scientific and Technical Information of China (English)

    郑然(综述); 李琴; 邹勇(审校)

    2016-01-01

    Acute brain damage and delayed encephalopathy are two main clinical manifestations of brain damage after carbon monoxide(CO) exposure,and seriously affect the life quality and prognosis of patients with CO poisoning.Hyperbaric oxygen is considered as the main therapy for brain damage after acute CO poi-soning.However,there are many controversies on its clinical application .The pathogenesis of brain damage after acute CO poisoning is poorly elucidated.The activation of nuclear factor erythrocyte two related factors-2 ( Nrf-2) may benefit the therapy for inflammatory and apoptosis mechanism triggered by CO poisoning .Thus, research on the role of Nrf-2 gene in the pathogenesis of brain damage following acute CO poisoning can pro-vide new ideas for the targeted therapy for the acute brain damage and delayed encephalopathy following CO poisoning.%一氧化碳中毒后的急性脑损伤和迟发型脑病严重影响患者的预后及生存质量。高压氧作为临床治疗一氧化碳中毒性脑损伤的主要方法争议颇多,而一氧化碳中毒性脑损伤的发病机制目前也尚未明确。核因子红细胞2相关因子2(Nrf-2)的激活可能对一氧化碳中毒引发的炎症、凋亡等发挥较好的治疗作用。因此,研究Nrf-2在一氧化碳中毒性脑损伤发病机制中的作用可为一氧化碳中毒后急性脑损伤和迟发型脑病的靶向治疗提供新思路。

  9. Damage Distributions

    DEFF Research Database (Denmark)

    Lützen, Marie

    2001-01-01

    the damage location, the damage sizes and the main particulars of the struck vessel. From the numerical simulation and the analyse of the damage statistics it is found that the current formulation from the IMO SLF 43/3/2 can be used as basis for determination of the p-, r-, and v-factors. Expressions...... and methods of calculation have been discussed. The damage distributions for the different vessels have been compared and analyses regarding relations between damage parameters and main particulars have been performed. The damage statistics collected in work package 1 have been analysed for relations between...... for the distribution of the non-dimensional damage location, the non-dimensional damage length and the non-dimensional penetrations have been derived. These distributions have been used as basis for a proposal for the p- and r-factors. Two proposals for the v-factor have been performed using the damage statistics...

  10. Pro-oxidative action of polyphenols as action mechanism for their pro-apoptotic activity.

    Science.gov (United States)

    Lecci, Raffaella Marina; Logrieco, Antonio; Leone, Antonella

    2014-01-01

    Polyphenols, secondary metabolites widely present in plant kingdom, are known for their positive effects on human health, such as treatments of degenerative disease and cancer. Many dietary polyphenols show anti-inflammatory, immunomodulatory and antioxidant properties and they are proposed as chemopreventive agents for many skin disorders and cancer. Exposure to solar UV radiation is widely considered to cause skin cancer and a consistent carcinogenic dose derived from UVA causes several skin disorders as a consequence of free radicals generation and DNA damages. In this study, verbascoside, isoverbascoside and tyrosol were investigated for their effects on HEKa (Human Epidermal Keratinocytes adult) cell cultures challenged from UVA-rays. Non-toxic doses of each polyphenol were assayed on HEKa before, during and after the exposure to a damaging dose of UVA. Treatment with polyphenols before and after the UVA-irradiation exerted a pro-oxidant effect, while the simultaneous treatment caused a weak decrease of ROS production. The increasing of ROS levels was associated with a proapoptotic effect on HEKa, detected by AnnexinV/Propidiun Iodide, mainly evident in surviving cells treated with the polyphenols after the UVA-irradiation. The pro-apoptotic effect was confirmed by the immunodetection of significant changes in the Bax and Bcl-xL protein levels, leading to apoptotic events. The hypothesis that these polyphenols could trigger the apoptosis pathway mainly in UVA-damaged cells, via ROS increase, is here proposed as action mechanism behind their protective effect.

  11. DJ-1 plays an important role in caffeic acid-mediated protection of the gastrointestinal mucosa against ketoprofen-induced oxidative damage.

    Science.gov (United States)

    Cheng, Yu-Ting; Ho, Cheng-Ying; Jhang, Jhih-Jia; Lu, Chi-Cheng; Yen, Gow-Chin

    2014-10-01

    Ketoprofen is widely used to alleviate pain and inflammation in clinical medicine; however, this drug may cause oxidative stress and lead to gastrointestinal (GI) ulcers. We previously reported that nuclear factor erythroid 2-related factor 2 (Nrf2) plays a crucial role in protecting cells against reactive oxygen species, and it facilitates the prevention of ketoprofen-induced GI mucosal ulcers. Recent reports suggested that Nrf2 becomes unstable in the absence of DJ-1/PARK7, attenuating the activity of Nrf2-regulated downstream antioxidant enzymes. Thus, increasing Nrf2 translocation by DJ-1 may represent a novel means for GI protection. In vitro, caffeic acid increases the nuclear/cytosolic Nrf2 ratio and the mRNA expression of the downstream antioxidant enzymes, ϒ-glutamyl cysteine synthetase, glutathione peroxidase, glutathione reductase, and heme oxygenase-1, by activating the JNK/p38 pathway in Int-407 cells. Moreover, knockdown of DJ-1 also reversed caffeic acid-induced nuclear Nrf2 protein expression in a JNK/p38-dependent manner. Our results also indicated that treatment of Sprague-Dawley rats with caffeic acid prior to the administration of ketoprofen inhibited oxidative damage and reversed the inhibitory effects of ketoprofen on the antioxidant system and DJ-1 protein expression in the GI mucosa. Our observations suggest that DJ-1 plays an important role in caffeic acid-mediated protection against ketoprofen-induced oxidative damage in the GI mucosa.

  12. Role of chemokines and their receptors in viral persistence and liver damage during chronic hepatitis C virus infection

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Chemokines produced in the liver during hepatitis C virus (HCV) infection induce migration of activated T cells from the periphery to infected parenchyma. The milieu of chemokines secreted by infected hepatocytes is predominantly associated with the T-helper cell/Tc1 T cell (Th1/Tc1) response. These chemokines consist of CCL3 (macrophage inflammatory protein-1α; MIP-1α), CCL4 (MIP-1β), CCL5 (regulated on activation normal T cell expressed and secreted; RANTES), CXCL10 (interferon-γ-inducible protein-10; IP-10),CXCL11 (interferon-inducible T-cell α chemoattractant; I-TAC), and CXCL9 (monokine induced by interferon γ; Mig) and they recruit T cells expressing either CCR5 or CXCR3 chemokine receptors. Intrahepatic and peripheral blood levels of these chemokines are increased during chronic hepatitis C. The interaction between chemokines and their receptors is essential in recruiting HCV-specific T cells to control the infection. When the adaptive immune response fails in this task, non-specific T cells without the capacity to control the infection are also recruited to the liver, and these are ultimately responsible for the persistent hepatic damage. The modulation of chemokine receptor expression and chemokine secretion could be a viral escape mechanism to avoid specific T cell migration to the liver during the early phase of infection, and to maintain liver viability during the chronic phase, by impairing non-specific T cell migration. Some chemokines and their receptors correlate with liver damage, and CXCL10 (IP-10) and CXCR3 levels have shown a clinical utility as predictors of treatment response outcome. The regulation of chemokines and their receptors could be a future potential therapeutic target to decrease liver inflammation and to increase specific T cell migration to the infected liver.

  13. The role of the cancer stem cell marker CD271 in DNA damage response and drug resistance of melanoma cells

    Science.gov (United States)

    Redmer, T; Walz, I; Klinger, B; Khouja, S; Welte, Y; Schäfer, R; Regenbrecht, C

    2017-01-01

    Several lines of evidence have suggested that stemness and acquired resistance to targeted inhibitors or chemotherapeutics are mechanistically linked. Here we observed high cell surface and total levels of nerve growth factor receptor/CD271, a marker of melanoma-initiating cells, in sub-populations of chemoresistant cell lines. CD271 expression was increased in drug-sensitive cells but not resistant cells in response to DNA-damaging chemotherapeutics etoposide, fotemustine and cisplatin. Comparative analysis of melanoma cells engineered to stably express CD271 or a targeting short hairpin RNA by expression profiling provided numerous genes regulated in a CD271-dependent manner. In-depth analysis of CD271-responsive genes uncovered the association of CD271 with regulation of DNA repair components. In addition, gene set enrichment analysis revealed enrichment of CD271-responsive genes in drug-resistant cells, among them DNA repair components. Moreover, our comparative screen identified the fibroblast growth factor 13 (FGF13) as a target of CD271, highly expressed in chemoresistant cells. Further we show that levels of CD271 determine drug response. Knock-down of CD271 in fotemustine-resistant cells decreased expression of FGF13 and at least partly restored sensitivity to fotemustine. Together, we demonstrate that expression of CD271 is responsible for genes associated with DNA repair and drug response. Further, we identified 110 CD271-responsive genes predominantly expressed in melanoma metastases, among them were NEK2, TOP2A and RAD51AP1 as potential drivers of melanoma metastasis. In addition, we provide mechanistic insight in the regulation of CD271 in response to drugs. We found that CD271 is potentially regulated by p53 and in turn is needed for a proper p53-dependent response to DNA-damaging drugs. In summary, we provide for the first time insight in a CD271-associated signaling network connecting CD271 with DNA repair, drug response and metastasis. PMID

  14. Proinflammatory cytokines activate the intrinsic apoptotic pathway in beta-cells

    DEFF Research Database (Denmark)

    Grunnet, Lars G; Aikin, Reid; Tonnesen, Morten F;

    2009-01-01

    of the intrinsic apoptotic pathway and the role of the two proapoptotic Bcl-2 proteins, Bad and Bax, were examined in beta-cells. RESEARCH DESIGN AND METHODS: Human and rat islets and INS-1 cells were exposed to a combination of proinflammatory cytokines (interleukin-1beta, interferon-gamma, and/or tumor necrosis......OBJECTIVE: Proinflammatory cytokines are cytotoxic to beta-cells and have been implicated in the pathogenesis of type 1 diabetes and islet graft failure. The importance of the intrinsic mitochondrial apoptotic pathway in cytokine-induced beta-cell death is unclear. Here, cytokine activation...... to investigate the role of Bad and Bax activation, respectively. RESULTS: We found that proinflammatory cytokines induced calcineurin-dependent dephosphorylation of Bad Ser136, mitochondrial stress, cytochrome c release, activation of caspase-9 and -3, and DNA fragmentation. Inhibition of Bad Ser136...

  15. p53 dependent apoptotic cell death induces embryonic malformation in Carassius auratus under chronic hypoxia.

    Directory of Open Access Journals (Sweden)

    Paramita Banerjee Sawant

    Full Text Available Hypoxia is a global phenomenon affecting recruitment as well as the embryonic development of aquatic fauna. The present study depicts hypoxia induced disruption of the intrinsic pathway of programmed cell death (PCD, leading to embryonic malformation in the goldfish, Carrasius auratus. Constant hypoxia induced the early expression of pro-apoptotic/tumor suppressor p53 and concomitant expression of the cell death molecule, caspase-3, leading to high level of DNA damage and cell death in hypoxic embryos, as compared to normoxic ones. As a result, the former showed delayed 4 and 64 celled stages and a delay in appearance of epiboly stage. Expression of p53 efficiently switched off expression of the anti-apoptotic Bcl-2 during the initial 12 hours post fertilization (hpf and caused embryonic cell death. However, after 12 hours, simultaneous downregulation of p53 and Caspase-3 and exponential increase of Bcl-2, caused uncontrolled cell proliferation and prevented essential programmed cell death (PCD, ultimately resulting in significant (p<0.05 embryonic malformation up to 144 hpf. Evidences suggest that uncontrolled cell proliferation after 12 hpf may have been due to downregulation of p53 abundance, which in turn has an influence on upregulation of anti-apoptotic Bcl-2. Therefore, we have been able to show for the first time and propose that hypoxia induced downregulation of p53 beyond 12 hpf, disrupts PCD and leads to failure in normal differentiation, causing malformation in gold fish embryos.

  16. p53 Dependent Apoptotic Cell Death Induces Embryonic Malformation in Carassius auratus under Chronic Hypoxia

    Science.gov (United States)

    Dasgupta, Subrata; Sawant, Bhawesh T.; Chadha, Narinder K.; Pal, Asim K.

    2014-01-01

    Hypoxia is a global phenomenon affecting recruitment as well as the embryonic development of aquatic fauna. The present study depicts hypoxia induced disruption of the intrinsic pathway of programmed cell death (PCD), leading to embryonic malformation in the goldfish, Carrasius auratus. Constant hypoxia induced the early expression of pro-apoptotic/tumor suppressor p53 and concomitant expression of the cell death molecule, caspase-3, leading to high level of DNA damage and cell death in hypoxic embryos, as compared to normoxic ones. As a result, the former showed delayed 4 and 64 celled stages and a delay in appearance of epiboly stage. Expression of p53 efficiently switched off expression of the anti-apoptotic Bcl-2 during the initial 12 hours post fertilization (hpf) and caused embryonic cell death. However, after 12 hours, simultaneous downregulation of p53 and Caspase-3 and exponential increase of Bcl-2, caused uncontrolled cell proliferation and prevented essential programmed cell death (PCD), ultimately resulting in significant (p<0.05) embryonic malformation up to 144 hpf. Evidences suggest that uncontrolled cell proliferation after 12 hpf may have been due to downregulation of p53 abundance, which in turn has an influence on upregulation of anti-apoptotic Bcl-2. Therefore, we have been able to show for the first time and propose that hypoxia induced downregulation of p53 beyond 12 hpf, disrupts PCD and leads to failure in normal differentiation, causing malformation in gold fish embryos. PMID:25068954

  17. Investigations on the C1q-calreticulin-phosphatidylserine interactions yield new insights into apoptotic cell recognition.

    Science.gov (United States)

    Païdassi, Helena; Tacnet-Delorme, Pascale; Verneret, Mélanie; Gaboriaud, Christine; Houen, Gunnar; Duus, Karen; Ling, Wai Li; Arlaud, Gérard J; Frachet, Philippe

    2011-04-29

    Both C1q and calreticulin (CRT) are involved in the recognition of apoptotic cells. CRT was initially characterized as a receptor for the C1q collagen-like fragment (CLF), whereas C1q was shown to bind apoptotic cells through its globular region (GR). Using purified CRT and recombinant CRT domains, we now provide unambiguous experimental evidence that, in addition to its CLF, the C1q GR also binds CRT and that both types of interactions are mediated by the CRT globular domain. Surface plasmon resonance analyses revealed that the C1q CLF and GR domains each bind individually to immobilized CRT and its globular domain with K(D) values of (2.6-8.3) × 10(-7) M. Further evidence that CRT binds to the C1q GR was obtained by electron microscopy. The role of CRT in the recognition of apoptotic HeLa cells by C1q was analyzed. The C1q GR partially colocalized with CRT on the surface of early apoptotic cells, and siRNA (small interfering RNA)-induced CRT deficiency resulted in increased apoptotic cell binding to C1q. The interaction between CRT and phosphatidylserine (PS), a known C1q ligand on apoptotic cells, was also investigated. The polar head of PS was shown to bind to CRT with a 10-fold higher affinity (K(D)=1.5 × 10(-5) M) than that determined for C1q, and, accordingly, the C1q GR-PS interaction was impaired in the presence of CRT. Together, these observations indicate that CRT, C1q, and PS are all closely involved in the uptake of apoptotic cells and strongly suggest a combinatorial role of these three molecules in the recognition step.

  18. Novel Approach for Evaluation of Bacteroides fragilis Protective Role against Bartonella henselae Liver Damage in Immunocompromised Murine Model

    Science.gov (United States)

    Pagliuca, Chiara; Cicatiello, Annunziata G.; Colicchio, Roberta; Greco, Adelaide; Cerciello, Raimondo; Auletta, Luigi; Albanese, Sandra; Scaglione, Elena; Pagliarulo, Caterina; Pastore, Gabiria; Mansueto, Gelsomina; Brunetti, Arturo; Avallone, Bice; Salvatore, Paola

    2016-01-01

    Bartonella henselae is a gram-negative facultative intracellular bacterium and is the causative agent of cat-scratch disease. Our previous data have established that Bacteroides fragilis colonization is able to prevent B. henselae damages through the polysaccharide A (PSA) in an experimental murine model. In order to determine whether the PSA is essential for the protection against pathogenic effects of B. henselae in immunocompromised hosts, SCID mice were co-infected with B. fragilis wild type or its mutant B. fragilis ΔPSA and the effects of infection on murine tissues have been observed by High-Frequency Ultrasound (HFUS), histopathological examination, and Transmission Electron Microscopy (TEM). For the first time, echostructure, hepatic lobes length, vascular alterations, and indirect signs of hepatic dysfunctions, routinely used as signs of disease in humans, have been analyzed in an immunocompromised murine model. Our findings showed echostructural alterations in all infected mice compared with the Phosphate Buffer Solution (PBS) control group; further, those infected with B. henselae and co-infected with B. henselae/B. fragilis ΔPSA presented the major echostructural alterations. Half of the mice infected with B. henselae and all those co-infected with B. henselae/B. fragilis ΔPSA have showed an altered hepatic echogenicity compared with the renal cortex. The echogenicity score of co-infected mice with B. henselae/B. fragilis ΔPSA differed significantly compared with the PBS control group (p < 0.05). Moreover the inflammation score of the histopathological evaluation was fairly concordant with ultrasound findings. Ultrastructural analysis performed by TEM revealed no significant alterations in liver samples of SCID mice infected with B. fragilis wild type while those infected with B. fragilis ΔPSA showed the presence of collagen around the main vessels compared with the PBS control group. The liver samples of mice infected with B. henselae showed

  19. The Putative Role of the Non-Gastric H+/K+-ATPase ATP12A (ATP1AL1 as Anti-Apoptotic Ion Transporter: Effect of the H+/K+ ATPase Inhibitor SCH28080 on Butyrate-Stimulated Myelomonocytic HL-60 Cells

    Directory of Open Access Journals (Sweden)

    Martin Jakab

    2014-10-01

    Full Text Available Background/Aims: The ATP12A gene codes for a non-gastric H+/K+ ATPase, which is expressed in a wide variety of tissues. The aim of this study was to test for the molecular and functional expression of the non-gastric H+/K+ ATPase ATP12A/ATP1AL1 in unstimulated and butyrate-stimulated (1 and 10 mM human myelomonocytic HL-60 cells, to unravel its potential role as putative apoptosis-counteracting ion transporter as well as to test for the effect of the H+/K+ ATPase inhibitor SCH28080 in apoptosis. Methods: Real-time reverse-transcription PCR (qRT-PCR was used for amplification and cloning of ATP12A transcripts and to assess transcriptional regulation. BCECF microfluorimetry was used to assess changes of intracellular pH (pHi after acute intracellular acid load (NH4Cl prepulsing. Mean cell volumes (MCV and MCV-recovery after osmotic cell shrinkage (Regulatory Volume Increase, RVI were assessed by Coulter counting. Flow-cytometry was used to measure MCV (Coulter principle, to assess apoptosis (phosphatidylserine exposure to the outer leaflet of the cell membrane, caspase activity, 7AAD staining and differentiation (CD86 expression. Results: We found by RT-PCR, intracellular pH measurements, MCV measurements and flow cytometry that ATP12A is expressed in human myelomonocytic HL-60 cells. Treatment of HL-60 cells with 1 mM butyrate leads to monocyte-directed differentiation whereas higher concentrations (10 mM induce apoptosis as assessed by flow-cytometric determination of CD86 expression, caspase activity, phosphatidylserine exposure on the outer leaflet of the cell membrane and MCV measurements. Transcriptional up-regulation of ATP12A and CD86 is evident in 1 mM butyrate-treated HL-60 cells. The H+/K+ ATPase inhibitor SCH28080 (100 µM diminishes K+-dependent pHi recovery after intracellular acid load and blocks RVI after osmotic cell shrinkage. After seeding, HL-60 cells increase their MCV within the first 24 h in culture, and subsequently

  20. The protective role of DJ-1 in ultraviolet-induced damage of human skin: DJ-1 levels in the stratum corneum as an indicator of antioxidative defense.

    Science.gov (United States)

    Ishiwatari, Shioji; Takahashi, Minako; Yasuda, Chie; Nakagawa, Maho; Saito, Yoshiro; Noguchi, Noriko; Matsukuma, Shoko

    2015-12-01

    DJ-1 is a multifunctional protein associated with Parkinson's disease and plays a significant role in protecting nerve cells from oxidative stress. DJ-1 is expressed in the skin, although its function there is unknown. In this study, we investigated DJ-1 function in keratinocytes. DJ-1 was induced by H2O2 exposure and UV irradiation in keratinocytes. DJ-1 knockdown with small interfering RNA (siRNA) increased reactive oxygen species (ROS) and lactate dehydrogenase (LDH) release after UVB irradiation, suggesting that DJ-1 reduces ROS and might protect skin cells from UV damage in vitro. To investigate the in vivo role of DJ-1 in the skin, we determined DJ-1 levels in human stratum corneum samples obtained by the tape-stripping method. DJ-1 levels in the stratum corneum (scDJ-1) correlated with total antioxidant capacity. We also examined the effect of scDJ-1 on changes in skin after UVB irradiation. DJ-1 was elevated in SC from the upper arm 1 to 2 weeks after UVB irradiation. One day after UVB irradiation, L* (brightness) and a* (redness) values, indicators of skin color, were altered regardless of scDJ-1 expression. However, these values recovered more quickly in subjects with high scDJ-1 expression than in those with low scDJ-1 expression. These data suggest that DJ-1 in skin plays a significant role in protection against UV radiation and oxidative stress, and that DJ-1 levels in the SC might be an indicator of antioxidative defense against UV-induced damage.

  1. New Insights in the Pathogenesis of Multiple Sclerosis—Role of Acrolein in Neuronal and Myelin Damage

    Directory of Open Access Journals (Sweden)

    Riyi Shi

    2013-10-01

    Full Text Available Multiple sclerosis (MS is an autoimmune disease of the central nervous system (CNS characterized by an inappropriate inflammatory reaction resulting in widespread myelin injury along white matter tracts. Neurological impairment as a result of the disease can be attributed to immune-mediated injury to myelin, axons and mitochondria, but the molecular mechanisms underlying the neuropathy remain incompletely understood. Incomplete mechanistic knowledge hinders the development of therapies capable of alleviating symptoms and slowing disease progression in the long-term. Recently, oxidative stress has been implicated as a key component of neural tissue damage prompting investigation of reactive oxygen species (ROS scavengers as a potential therapeutic option. Despite the establishment of oxidative stress as a crucial process in MS development and progression, ROS scavengers have had limited success in animal studies which has prompted pursuit of an alternative target capable of curtailing oxidative stress. Acrolein, a toxic β-unsaturated aldehyde capable of initiating and perpetuating oxidative stress, has been suggested as a viable point of intervention to guide the development of new treatments. Sequestering acrolein using an FDA-approved compound, hydralazine, offers neuroprotection resulting in dampened symptom severity and slowed disease progression in experimental autoimmune encephalomyelitis (EAE mice. These results provide promise for therapeutic development, indicating the possible utility of neutralizing acrolein to preserve and improve neurological function in MS patients.

  2. Protective role of Diospyros lotus on cisplatin-induced changes in sperm characteristics, testicular damage and oxidative stress in rats.

    Science.gov (United States)

    Saral, S; Ozcelik, E; Cetin, A; Saral, O; Basak, N; Aydın, M; Ciftci, O

    2016-04-01

    The aim of this study was to investigate the protective effect of Diospyros lotus (DL) on cisplatin (CP)-induced testicular damage in male rats. Twenty-eight male rats were randomly divided into four groups: group 1 - control, given isotonic saline solution; group 2 - CP 7 mg kg(-1) given intraperitoneally as single dose; group 3 - DL 1000 mg kg(-1) per day given orally for 10 days; group 4 - CP and DL given together at the same doses. CP caused a significant increase in thiobarbituric acid-reactive substances (TBARS) level and a significant decrease in superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and glutathione (GSH) levels in rats testis tissues compared to the control group. CP caused a significant increase in lipid peroxidation in testis tissues compared to the control group, whereas DL led to a significant increase in SOD and GSH levels. However, there were no statistically significant changes in GPx and CAT levels. In addition, serum testosterone levels, sperm concentration and sperm motility were significantly decreased, but abnormal sperm rate and histological changes were increased with CP. However, these effects of CP on sperm parameters, histological changes and the tissue weights were eliminated by DL treatment. In conclusion, our study showed that the reproductive toxicity caused by CP may be prevented by DL treatment.

  3. Laser ablation and optical surface damage

    Science.gov (United States)

    Chase, L. L.; Hamza, A. V.; Lee, H. W. H.

    Laser ablation usually accompanies optical surface damage to bare surfaces and coatings. Investigations of optical damage mechanisms by observation of ablation processes at laser fluences very close to the optical damage threshold are described. Several promising surface characterization methods for investigating damage mechanisms are also described. The possible role of laser ablation in initiating or promoting optical surface damage is discussed.

  4. Laser ablation mechanisms and optical surface damage

    Science.gov (United States)

    Chase, L. L.; Hamza, A. V.; Lee, H. W. H.

    1991-05-01

    Laser ablation usually accompanies optical surface damage to bare surfaces and coatings. Investigations of optical damage mechanisms by observation of ablation processes at laser fluences very close to the optical damage threshold are described. Several promising surface characterization methods for investigating damage mechanisms are also described. The possible role of laser ablation in initiating or promoting optical surface damage is discussed.

  5. Protein C inhibitor (PCI binds to phosphatidylserine exposing cells with implications in the phagocytosis of apoptotic cells and activated platelets.

    Directory of Open Access Journals (Sweden)

    Daniela Rieger

    Full Text Available Protein C Inhibitor (PCI is a secreted serine protease inhibitor, belonging to the family of serpins. In addition to activated protein C PCI inactivates several other proteases of the coagulation and fibrinolytic systems, suggesting a regulatory role in hemostasis. Glycosaminoglycans and certain negatively charged phospholipids, like phosphatidylserine, bind to PCI and modulate its activity. Phosphatidylerine (PS is exposed on the surface of apoptotic cells and known as a phagocytosis marker. We hypothesized that PCI might bind to PS exposed on apoptotic cells and thereby influence their removal by phagocytosis. Using Jurkat T-lymphocytes and U937 myeloid cells, we show here that PCI binds to apoptotic cells to a similar extent at the same sites as Annexin V, but in a different manner as compared to live cells (defined spots on ∼10-30% of cells. PCI dose dependently decreased phagocytosis of apoptotic Jurkat cells by U937 macrophages. Moreover, the phagocytosis of PS exposing, activated platelets by human blood derived monocytes declined in the presence of PCI. In U937 cells the expression of PCI as well as the surface binding of PCI increased with time of phorbol ester treatment/macrophage differentiation. The results of this study suggest a role of PCI not only for the function and/or maturation of macrophages, but also as a negative regulator of apoptotic cell and activated platelets removal.

  6. Protein C inhibitor (PCI) binds to phosphatidylserine exposing cells with implications in the phagocytosis of apoptotic cells and activated platelets.

    Science.gov (United States)

    Rieger, Daniela; Assinger, Alice; Einfinger, Katrin; Sokolikova, Barbora; Geiger, Margarethe

    2014-01-01

    Protein C Inhibitor (PCI) is a secreted serine protease inhibitor, belonging to the family of serpins. In addition to activated protein C PCI inactivates several other proteases of the coagulation and fibrinolytic systems, suggesting a regulatory role in hemostasis. Glycosaminoglycans and certain negatively charged phospholipids, like phosphatidylserine, bind to PCI and modulate its activity. Phosphatidylerine (PS) is exposed on the surface of apoptotic cells and known as a phagocytosis marker. We hypothesized that PCI might bind to PS exposed on apoptotic cells and thereby influence their removal by phagocytosis. Using Jurkat T-lymphocytes and U937 myeloid cells, we show here that PCI binds to apoptotic cells to a similar extent at the same sites as Annexin V, but in a different manner as compared to live cells (defined spots on ∼10-30% of cells). PCI dose dependently decreased phagocytosis of apoptotic Jurkat cells by U937 macrophages. Moreover, the phagocytosis of PS exposing, activated platelets by human blood derived monocytes declined in the presence of PCI. In U937 cells the expression of PCI as well as the surface binding of PCI increased with time of phorbol ester treatment/macrophage differentiation. The results of this study suggest a role of PCI not only for the function and/or maturation of macrophages, but also as a negative regulator of apoptotic cell and activated platelets removal.

  7. A UV-sensitive syndrome patient with a specific CSA mutation reveals separable roles for CSA in response to UV and oxidative DNA damage.

    Science.gov (United States)

    Nardo, Tiziana; Oneda, Roberta; Spivak, Graciela; Vaz, Bruno; Mortier, Laurent; Thomas, Pierre; Orioli, Donata; Laugel, Vincent; Stary, Anne; Hanawalt, Philip C; Sarasin, Alain; Stefanini, Miria

    2009-04-14

    UV-sensitive syndrome (UV(S)S) is a recently-identified autosomal recessive disorder characterized by mild cutaneous symptoms and defective transcription-coupled repair (TC-NER), the subpathway of nucleotide excision repair (NER) that rapidly removes damage that can block progression of the transcription machinery in actively-transcribed regions of DNA. Cockayne syndrome (CS) is another genetic disorder with sun sensitivity and defective TC-NER, caused by mutations in the CSA or CSB genes. The clinical hallmarks of CS include neurological/developmental abnormalities and premature aging. UV(S)S is genetically heterogeneous, in that it appears in individuals with mutations in CSB or in a still-unidentified gene. We report the identification of a UV(S)S patient (UV(S)S1VI) with a novel mutation in the CSA gene (p.trp361cys) that confers hypersensitivity to UV light, but not to inducers of oxidative damage that are notably cytotoxic in cells from CS patients. The defect in UV(S)S1VI cells is corrected by expression of the WT CSA gene. Expression of the p.trp361cys-mutated CSA cDNA increases the resistance of cells from a CS-A patient to oxidative stress, but does not correct their UV hypersensitivity. These findings imply that some mutations in the CSA gene may interfere with the TC-NER-dependent removal of UV-induced damage without affecting its role in the oxidative stress response. The differential sensitivity toward oxidative stress might explain the difference between the range and severity of symptoms in CS and the mild manifestations in UV(s)S patients that are limited to skin photosensitivity without precocious aging or neurodegeneration.

  8. DNA damage and autophagy

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Rocha, Humberto; Garcia-Garcia, Aracely [Redox Biology Center and School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE 68583 (United States); Panayiotidis, Mihalis I. [School of Community Health Sciences, University of Nevada, Reno, NV 89557 (United States); Franco, Rodrigo, E-mail: rfrancocruz2@unl.edu [Redox Biology Center and School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE 68583 (United States)

    2011-06-03

    Both exogenous and endogenous agents are a threat to DNA integrity. Exogenous environmental agents such as ultraviolet (UV) and ionizing radiation, genotoxic chemicals and endogenous byproducts of metabolism including reactive oxygen species can cause alterations in DNA structure (DNA damage). Unrepaired DNA damage has been linked to a variety of human disorders including cancer and neurodegenerative disease. Thus, efficient mechanisms to detect DNA lesions, signal their presence and promote their repair have been evolved in cells. If DNA is effectively repaired, DNA damage response is inactivated and normal cell functioning resumes. In contrast, when DNA lesions cannot be removed, chronic DNA damage triggers specific cell responses such as cell death and senescence. Recently, DNA damage has been shown to induce autophagy, a cellular catabolic process that maintains a balance between synthesis, degradation, and recycling of cellular components. But the exact mechanisms by which DNA damage triggers autophagy are unclear. More importantly, the role of autophagy in the DNA damage response and cellular fate is unknown. In this review we analyze evidence that supports a role for autophagy as an integral part of the DNA damage response.

  9. Roles of hydrogen sulfide and nitric oxide in the alleviation of cadmium-induced oxidative damage in alfalfa seedling roots.

    Science.gov (United States)

    Li, Le; Wang, Yanqin; Shen, Wenbiao

    2012-06-01

    Despite hydrogen sulfide (H(2)S) and nitric oxide (NO) are important endogenous signals or bioregulators involved in many vital aspects of plant growth and responses against abiotic stresses, little information was known about their interaction. In the present study, we evaluated the effects of H(2)S and NO on alfalfa (Medicago sativa L.) plants exposed to cadmium (Cd) stress. Pretreatment with an H(2)S donor sodium hydrosulfide (NaHS) and well-known NO donor sodium nitroprusside (SNP) decreased the Cd toxicity. This conclusion was supported by the decreases of lipid peroxidation as well as the amelioration of seedling growth inhibition and Cd accumulation, in comparison with the Cd-stressed alone plants. Total activities and corresponding transcripts of antioxidant enzymes, including superoxide dismutase, peroxidase and ascorbate peroxidase were modulated differentially, thus leading to the alleviation of oxidative damage. Effects of H(2)S above were reversed by 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide potassium salt (cPTIO), the specific scavenger of NO. By using laser confocal scanning microscope combined with Greiss reagent method, further results showed that NO production increased significantly after the NaHS pretreatment regardless of whether Cd was applied or not, all of which were obviously inhibited by cPTIO. These decreases of NO production were consistent with the exaggerated syndromes associated with Cd toxicity. Together, above results suggested that NO was involved in the NaHS-induced alleviation of Cd toxicity in alfalfa seedlings, and also indicated that there exists a cross-talk between H(2)S and NO responsible for the increased abiotic stress tolerance.

  10. X-ray diffraction study of microstructural changes during fatigue damage initiation in pipe steels: Role of the initial dislocation structure

    Energy Technology Data Exchange (ETDEWEB)

    Pinheiro, B., E-mail: bianca@lts.coppe.ufrj.br [Laboratory of Mechanics of Lille (LML), UMR CNRS 8107, University Lille 1, Boulevard Paul Langevin, Cité Scientifique, 59655 Villeneuve d' Ascq (France); Lesage, J. [Laboratory of Mechanics of Lille (LML), UMR CNRS 8107, University Lille 1, Boulevard Paul Langevin, Cité Scientifique, 59655 Villeneuve d' Ascq (France); Pasqualino, I. [Subsea Technology Laboratory (LTS), Ocean Engineering Department, COPPE/Federal University of Rio de Janeiro, PO Box 68508, Cidade Universitária, CEP 21945-970, Rio de Janeiro/RJ (Brazil); Bemporad, E. [University of Rome “ROMA TRE”, Mechanical and Industrial Eng. Dept., Via Vasca Navale 79, 00146 Rome (Italy); Benseddiq, N. [Laboratory of Mechanics of Lille (LML), UMR CNRS 8107, University Lille 1, Boulevard Paul Langevin, Cité Scientifique, 59655 Villeneuve d' Ascq (France)

    2013-09-15

    The present work is the second part of an ongoing study of microstructural changes during fatigue damage initiation in pipe steels [B. Pinheiro et al., Mat. Sci. Eng., A 532 (2012) 158–166]. Microdeformations and residual stresses (macrostresses) are evaluated by X-ray diffraction during alternating bending fatigue tests on samples taken from an API 5L X60 grade steel pipe. Microdeformations are evaluated from the full width at half maximum (FWHM) of the diffraction peak and residual stresses are estimated from the peak shift. Here, to understand the role of the initial dislocation structure, annealed samples are considered. As previously found for as-machined samples, the evolution of microdeformations shows three regular successive stages, but now with an increase during the first stage. The amplitude of each stage is accentuated with increasing stress amplitude, while its duration is reduced. Residual stresses show a similar trend, with stages of the same durations than those observed for FWHM, respectively. Additionally, changes in density and distribution of dislocations are observed by transmission electron microscopy combined with the technique of focused ion beam. The results are very encouraging for the development of a future indicator of fatigue damage initiation for pipe steels based on microstructural changes measured by X-ray diffraction.

  11. An Emerging Role of Glucagon-Like Peptide-1 in Preventing Advanced-Glycation-End-Product-Mediated Damages in Diabetes

    Directory of Open Access Journals (Sweden)

    Alessandra Puddu

    2013-01-01

    Full Text Available Glucagon-like peptide-1 (GLP-1 is a gut hormone produced in the intestinal epithelial endocrine L cells by differential processing of the proglucagon gene. Released in response to the nutrient ingestion, GLP-1 plays an important role in maintaining glucose homeostasis. GLP-1 has been shown to regulate blood glucose levels by stimulating glucose-dependent insulin secretion and inhibiting glucagon secretion, gastric emptying, and food intake. These antidiabetic activities highlight GLP-1 as a potential therapeutic molecule in the clinical management of type 2 diabetes, (a disease characterized by progressive decline of beta-cell function and mass, increased insulin resistance, and final hyperglycemia. Since chronic hyperglycemia contributed to the acceleration of the formation of Advanced Glycation End-Products (AGEs, a heterogeneous group of compounds derived from the nonenzymatic reaction of reducing sugars with free amino groups of proteins implicated in vascular diabetic complications, the administration of GLP-1 might directly counteract diabetes pathophysiological processes (such as pancreatic β-cell dysfunction. This paper outlines evidence on the protective role of GLP-1 in preventing the deleterious effects mediated by AGEs in type 2 diabetes.

  12. The role of endotoxin in the pathogenesis of gastric mucosal damage in cirrhotic rats with portal hypertensive gastropathy

    Institute of Scientific and Technical Information of China (English)

    ChengLan; XiaoningSun; LiweiDong; BailiHuang; SuYuan; KeliWu

    2011-01-01

    Objective:To study the role and the mechanism of endotoxin in the pathogenesis of gastric mucosa during portal vein hypertension gastrography (PHG) in the rats with cirrhosis. Methods:Rat model for PHG was established by injection of tetrachloride. The animals were injected with endotoxin i.p. at 3 mg/kg and endotoxin antagonist BPI21 i.v. at 2.0 mg/kg. The plasma level of endotoxin as well as the gastric mucosal level of tumor necrosis factor alpha (TNF-α) was measured with azobenzene and ELISA respectively. Furthermore, the pathological changes of the gastric mucosa were studied with HE stainning. Results:In rats with PHG, increased endotoxin and TNF-αas well as the gastric pathological lesion were observed. Injection of endotoxin remarkably increased plasma level of endotoxin as well as the gastric mucosal level of tumor necrosis TNF-αand induced more serious gastric lesion. Animals injected with endotoxin antagonist BPI21 showed improved gastric mucosal lesion, accompanied by the declining TNF-αlevel. Conclusions:Our results suggestes that endotoxin may play a pathogenetic role in PHG by inducing the expression of TNF-α.

  13. Characterization of recombinase DMC1B and its functional role as Rad51 in DNA damage repair in Giardia duodenalis trophozoites.

    Science.gov (United States)

    Torres-Huerta, Ana Laura; Martínez-Miguel, Rosa María; Bazán-Tejeda, María Luisa; Bermúdez-Cruz, Rosa María

    2016-08-01

    Homologous recombination (HR) is a highly conserved pathway for the repair of chromosomes that harbor DNA double-stranded breaks (DSBs). The recombinase RAD51 plays a key role by catalyzing the pairing of homologous DNA molecules and the exchange of information between them. Two putative DMC1 homologs (DMC1A and DMC1B) have been identified in Giardia duodenalis. In terms of sequences, GdDMC1A and GdDMC1B bear all of the characteristic recombinase domains: DNA binding domains (helix-turn-helix motif, loops 1 and 2), an ATPcap and Walker A and B motifs associated with ATP binding and hydrolysis. Because GdDMC1B is expressed at the trophozoite stage and GdDMC1A is expressed in the cyst stage, we cloned the giardial dmc1B gene and expressed and purified its protein to determine its activities, including DNA binding, ATP hydrolysis, and DNA strand exchange. Our results revealed that it possessed these activities, and they were modulated by divalent metal ions in different manners. GdDMC1B expression at the protein and transcript levels, as well as its subcellular localization in trophozoites upon DNA damage, was assessed. We found a significant increase in GdDMC1B transcript and protein levels after ionizing radiation treatment. Additionally, GdDMC1B protein was mostly located in the nucleus of trophozoites after DNA damage. These results indicate that GdDMC1B is the recombinase responsible for DSBs repair in the trophozoite; therefore, a functional Rad51 role is proposed for GdDMC1B.

  14. Cobra venom cytotoxins; apoptotic or necrotic agents?

    Science.gov (United States)

    Ebrahim, Karim; Shirazi, Farshad H; Mirakabadi, Abbas Zare; Vatanpour, Hossein

    2015-12-15

    Organs homeostasis is controlled by a dynamic balance between cell proliferation and apoptosis. Failure to induction of apoptosis has been implicated in tumor development. Cytotoxin-I (CTX-I) and cytotoxin-II (CTX-II) are two physiologically active polypeptides found in Caspian cobra venom. Anticancer activity and mechanism of cell death induced by these toxins have been studied. The toxins were purified by different chromatographic steps and their cytotoxicity and pattern of cell death were determined by MTT, LDH release, acridine orange/ethidium bromide (AO/EtBr) double staining, flow cytometric analysis, caspase-3 activity and neutral red assays. The IC50 of CTX-II in MCF-7, HepG2, DU-145 and HL-60 was 4.1 ± 1.3, 21.2 ± 4.4, 9.4 ± 1.8 μg/mL and 16.3 ± 1.9 respectively while the IC50 of this toxin in normal MDCK cell line was 54.5 ± 3.9 μg/mL. LDH release suddenly increase after a specific toxins concentrations in all cell lines. AO/EtBr double staining, flow cytometric analysis and caspase-3 activity assay confirm dose and time-dependent induction of apoptosis by both toxins. CTX-I and CTX-II treated cells lost their lysosomal membrane integrity and couldn't uptake neutral red day. CTX-I and CTX-II showed significant anticancer activity with minimum effects on normal cells and better IC50 compared to current anticancer drug; cisplatin. They induce their apoptotic effect via lysosomal pathways and release of cathepsins to cytosol. These effects were seen in limited rage of toxins concentrations and pattern of cell death rapidly changes to necrosis by increase in toxin's concentration. In conclusion, significant apoptogenic effects of these toxins candidate them as a possible anticancer agent.

  15. Withania somnifera alleviates parkinsonian phenotypes by inhibiting apoptotic pathways in dopaminergic neurons.

    Science.gov (United States)

    Prakash, Jay; Chouhan, Shikha; Yadav, Satyndra Kumar; Westfall, Susan; Rai, Sachchida Nand; Singh, Surya Pratap

    2014-12-01

    Maneb (MB) and paraquat (PQ) are environmental toxins that have been experimentally used to induce selective damage of dopaminergic neurons leading to the development of Parkinson's disease (PD). Although the mechanism of this selective neuronal toxicity in not fully understood, oxidative stress has been linked to the pathogenesis of PD. The present study investigates the mechanisms of neuroprotection elicited by Withania somnifera (Ws), a herb traditionally recognized by the Indian system of medicine, Ayurveda. An ethanolic root extract of Ws was co-treated with the MB-PQ induced mouse model of PD and was shown to significantly rescue canonical indicators of PD including compromised locomotor activity, reduced dopamine in the substantia nigra and various aspects of oxidative damage. In particular, Ws reduced the expression of iNOS, a measure of oxidative stress. Ws also significantly improved the MB + PQ mediated induction of a pro-apoptotic state by reducing Bax and inducing Bcl-2 protein expression, respectively. Finally, Ws reduced expression of the pro-inflammatory marker of astrocyte activation, GFAP. Altogether, the present study suggests that Ws treatment provides nigrostriatal dopaminergic neuroprotection against MB-PQ induced Parkinsonism by the modulation of oxidative stress and apoptotic machinery possibly accounting for the behavioural effects.

  16. Role of heat shock protein in regulation of JNK and apoptosis%HSP70调节应激活化蛋白激酶JNK活性与细胞凋亡

    Institute of Scientific and Technical Information of China (English)

    谭红梅; 吴伟康

    2001-01-01

    Cell protection from stresses by heat shock protein (HSP) was previously attributed to its ability to prevent aggregation and to accelerate refolding of damaged proteins. It plays an important role in cell survival after extremely harsh protein damaging treatment leading to necrotic cell death. On the other hand, protein repair function of HSP cannot explain how it protects cell from stresses which do not cause direct protein damage. These stresses kill cell through activation of apoptotic program. Recently it has been found that HSP can meditate suppression of a stress-activated protein kinase, JNK, an early component of stress-induced apoptotic signaling pathway.These observations can provide a basis for HSP's function of anti-apoptosis.

  17. Genes of the mitochondrial apoptotic pathway in Mytilus galloprovincialis.

    Directory of Open Access Journals (Sweden)

    Noelia Estévez-Calvar

    Full Text Available Bivalves play vital roles in marine, brackish, freshwater and terrestrial habitats. In recent years, these ecosystems have become affected through anthropogenic activities. The ecological success of marine bivalves is based on the ability to modify their physiological functions in response to environmental changes. One of the most important mechanisms involved in adaptive responses to environmental and biological stresses is apoptosis, which has been scarcely studied in mollusks, although the final consequence of this process, DNA fragmentation, has been frequently used for pollution monitoring. Environmental stressors induce apoptosis in molluscan cells via an intrinsic pathway. Many of the proteins involved in vertebrate apoptosis have been recognized in model invertebrates; however, this process might not be universally conserved. Mytilus galloprovincialis is presented here as a new model to study the linkage between molecular mechanisms that mediate apoptosis and marine bivalve ecological adaptations. Therefore, it is strictly necessary to identify the key elements involved in bivalve apoptosis. In the present study, six mitochondrial apoptotic-related genes were characterized, and their gene expression profiles following UV irradiation were evaluated. This is the first step for the development of potential biomarkers to assess the biological responses of marine organisms to stress. The results confirmed that apoptosis and, more specifically, the expression of the genes involved in this process can be used to assess the biological responses of marine organisms to stress.

  18. An overview of caspase: Apoptotic protein for silicosis

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    Tumane Rajani

    2010-01-01

    Full Text Available Silicosis is a chronic lung disease characterized by granulomatous and fibrotic lesions, which occurs due to accumulation of respirable silica mineral particles. Apoptosis is an important phenomenon of cell death in silicosis. The relationship between silica dust and its exposure is well established. But, the complex chain of cellular responses, which leads to caspase activation in silicosis, has not been fully discovered. Caspase activation plays a central role in the execution of apoptosis. Silica-induced apoptosis of the alveolar macrophages could potentially favor a proinflammatory state, occurring in the lungs of silicotic patients, resulting in the activation of caspase prior to induction of the intrinsic and extrinsic apoptosis pathways. Recent studies indicated that apoptosis may involve in pulmonary disorders. This review summarizes the current knowledge about the underling mechanism of biochemical pathways in caspase activation that have been ignored so far in silicosis. In addition, caspase could be a key apoptotic protein that can be used as an effective biomarker for the study of occupational diseases. It may provide an important link in understanding the molecular mechanisms of silica-induced lung pathogenesis.

  19. Relationship between apoptotic markers in semen from fertile men and demographic, hormonal and seminal characteristics

    DEFF Research Database (Denmark)

    O Specht, Ina; Spanò, Marcello; S Hougaard, Karin

    2012-01-01

    and biological correlates of the pro-apoptotic marker Fas and the anti-apoptotic marker Bcl-xL in sperm cells of fertile men. Six hundred and four men from Greenland, Poland and Ukraine were consecutively enrolled during their pregnant wife's antenatal visits. Semen analysis was performed as recommended...... (TUNEL) assay. The percentage of Fas-positive sperm cells was higher in men with high total sperm count (P......Apoptosis in the testis has two putative roles during normal spermatogenesis; limitation of the germ cell population to numbers that can be supported by the Sertoli cells, and, possibly, selective depletion of meiotic and postmeiotic abnormal germ cells. We investigated the demographic...

  20. Pro-apoptotic NOXA is implicated in atmospheric-pressure plasma-induced melanoma cell death

    Science.gov (United States)

    Ishaq, M.; Bazaka, K.; Ostrikov, K.

    2015-11-01

    Atmospheric-pressure plasma (APP) has been successfully used to treat several types of cancers in vivo and in vitro, with the effect being primarily attributed to the generation of reactive oxygen species (ROS). However, the mechanisms by which APP induces apoptosis in cancer cells require further elucidation. In this study, the effects of APP on the expression of 500 genes in melanoma Mel007 cancer cells were examined. Pro-apoptotic phorbol-12-myristate-13-acetate-induced protein (PMAIP1), also known as NOXA, was highly expressed as a result of APP treatment in a dose-dependent manner. Blocking of ROS using scavenger NAC or silencing of NOXA gene by RNA interference inhibited the APP-induced NOXA genes upregulation and impaired caspases 3/7 mediated apoptosis, confirming the important role plasma-generated ROS species and pro-apoptotic NOXA play in APP-induced cancer cell death.

  1. Role of collagens and perlecan in microvascular stability: exploring the mechanism of capillary vessel damage by snake venom metalloproteinases.

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    Teresa Escalante

    Full Text Available Hemorrhage is a clinically important manifestation of viperid snakebite envenomings, and is induced by snake venom metalloproteinases (SVMPs. Hemorrhagic and non-hemorrhagic SVMPs hydrolyze some basement membrane (BM and associated extracellular matrix (ECM proteins. Nevertheless, only hemorrhagic SVMPs are able to disrupt microvessels; the mechanisms behind this functional difference remain largely unknown. We compared the proteolytic activity of the hemorrhagic P-I SVMP BaP1, from the venom of Bothrops asper, and the non-hemorrhagic P-I SVMP leucurolysin-a (leuc-a, from the venom of Bothrops leucurus, on several substrates in vitro and in vivo, focusing on BM proteins. When incubated with Matrigel, a soluble extract of BM, both enzymes hydrolyzed laminin, nidogen and perlecan, albeit BaP1 did it at a faster rate. Type IV collagen was readily digested by BaP1 while leuc-a only induced a slight hydrolysis. Degradation of BM proteins in vivo was studied in mouse gastrocnemius muscle. Western blot analysis of muscle tissue homogenates showed a similar degradation of laminin chains by both enzymes, whereas nidogen was cleaved to a higher extent by BaP1, and perlecan and type IV collagen were readily digested by BaP1 but not by leuc-a. Immunohistochemistry of muscle tissue samples showed a decrease in the immunostaining of type IV collagen after injection of BaP1, but not by leuc-a. Proteomic analysis by LC/MS/MS of exudates collected from injected muscle revealed higher amounts of perlecan, and types VI and XV collagens, in exudates from BaP1-injected tissue. The differences in the hemorrhagic activity of these SVMPs could be explained by their variable ability to degrade key BM and associated ECM substrates in vivo, particularly perlecan and several non-fibrillar collagens, which play a mechanical stabilizing role in microvessel structure. These results underscore the key role played by these ECM components in the mechanical stability of

  2. In vitro study of immunosuppressive effect of apoptotic cells

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wen-jin; ZHENG Shu-sen

    2005-01-01

    Recent studies revealed that apoptotic cells are actively involved in immunosuppression and anti-inflammation. After being phagocytosed by macrophages, apoptotic cells can actively regulate cytokines secretion from lipopolysaccharide (LPS)-stimulated macrophages, in which the secretion of immunosuppressive cytokines such as interleukin-10 (IL-10) is increased while the pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNFα), interleukin-1beta (IL-1β) and leukin-8 (IL-8) are suppressed. In this paper, we first present evidence that phagocytosed apoptotic cells regulate cytokine secretion of LPS-stimulated macrophages, but also inhibit the activation of T lymphocytes stimulated by ConA. These data suggest that apoptotic cells can alter the biological behavior of macrophages which gain immunosuppressive property.

  3. Oncogenic Properties of Apoptotic Tumor Cells in Aggressive B Cell Lymphoma

    Science.gov (United States)

    Ford, Catriona A.; Petrova, Sofia; Pound, John D.; Voss, Jorine J.L.P.; Melville, Lynsey; Paterson, Margaret; Farnworth, Sarah L.; Gallimore, Awen M.; Cuff, Simone; Wheadon, Helen; Dobbin, Edwina; Ogden, Carol Anne; Dumitriu, Ingrid E.; Dunbar, Donald R.; Murray, Paul G.; Ruckerl, Dominik; Allen, Judith E.; Hume, David A.; van Rooijen, Nico; Goodlad, John R.; Freeman, Tom C.; Gregory, Christopher D.

    2015-01-01

    Summary Background Cells undergoing apoptosis are known to modulate their tissue microenvironments. By acting on phagocytes, notably macrophages, apoptotic cells inhibit immunological and inflammatory responses and promote trophic signaling pathways. Paradoxically, because of their potential to cause death of tumor cells and thereby militate against malignant disease progression, both apoptosis and tumor-associated macrophages (TAMs) are often associated with poor prognosis in cancer. We hypothesized that, in progression of malignant disease, constitutive loss of a fraction of the tumor cell population through apoptosis could yield tumor-promoting effects. Results Here, we demonstrate that apoptotic tumor cells promote coordinated tumor growth, angiogenesis, and accumulation of TAMs in aggressive B cell lymphomas. Through unbiased “in situ transcriptomics” analysis—gene expression profiling of laser-captured TAMs to establish their activation signature in situ—we show that these cells are activated to signal via multiple tumor-promoting reparatory, trophic, angiogenic, tissue remodeling, and anti-inflammatory pathways. Our results also suggest that apoptotic lymphoma cells help drive this signature. Furthermore, we demonstrate that, upon induction of apoptosis, lymphoma cells not only activate expression of the tumor-promoting matrix metalloproteinases MMP2 and MMP12 in macrophages but also express and process these MMPs directly. Finally, using a model of malignant melanoma, we show that the oncogenic potential of apoptotic tumor cells extends beyond lymphoma. Conclusions In addition to its profound tumor-suppressive role, apoptosis can potentiate cancer progression. These results have important implications for understanding the fundamental biology of cell death, its roles in malignant disease, and the broader consequences of apoptosis-inducing anti-cancer therapy. PMID:25702581

  4. Nutri-epigenetics ameliorates blood-brain barrier damage and neurodegeneration in hyperhomocysteinemia: role of folic acid.

    Science.gov (United States)

    Kalani, Anuradha; Kamat, Pradip K; Givvimani, Srikanth; Brown, Kasey; Metreveli, Naira; Tyagi, Suresh C; Tyagi, Neetu

    2014-02-01

    Epigenetic mechanisms underlying nutrition (nutrition epigenetics) are important in understanding human health. Nutritional supplements, for example folic acid, a cofactor in one-carbon metabolism, regulate epigenetic alterations and may play an important role in the maintenance of neuronal integrity. Folic acid also ameliorates hyperhomocysteinemia, which is a consequence of elevated levels of homocysteine. Hyperhomocysteinemia induces oxidative stress that may epigenetically mediate cerebrovascular remodeling and leads to neurodegeneration; however, the mechanisms behind such alterations remain unclear. Therefore, the present study was designed to observe the protective effects of folic acid against hyperhomocysteinemia-induced epigenetic and molecular alterations leading to neurotoxic cascades. To test this hypothesis, we employed 8-weeks-old male wild-type (WT) cystathionine-beta-synthase heterozygote knockout methionine-fed (CBS+/− + Met), WT, and CBS+/− + Met mice supplemented with folic acid (FA) [WT + FA and CBS+/− + Met + FA, respectively, 0.0057-μg g−1 day−1 dose in drinking water/4 weeks]. Hyperhomocysteinemia in CBS+/− + Met mouse brain was accompanied by a decrease in methylenetetrahydrofolate reductase and an increase in S-adenosylhomocysteine hydrolase expression, symptoms of oxidative stress, upregulation of DNA methyltransferases, rise in matrix metalloproteinases, a drop in the tissue inhibitors of metalloproteinases, decreased expression of tight junction proteins, increased permeability of the blood-brain barrier, neurodegeneration, and synaptotoxicity. Supplementation of folic acid to CBS+/− + Met mouse brain led to a decrease in the homocysteine level and rescued pathogenic and epigenetic alterations, showing its protective efficacy against homocysteine-induced neurotoxicity.

  5. Induction of C-Mip by IL-17 Plays an Important Role in Adriamycin-Induced Podocyte Damage

    Directory of Open Access Journals (Sweden)

    Yanbo Liu

    2015-07-01

    Full Text Available Background/Aims: Although the disturbance of T lymphocyte and glomerular podocyte exerts a crucial function in the pathogenesis of proteinuria, the potential link is still unclear. Methods: The balance of Treg and Th17 cells, and the expression of IL-17/IL-17R and c-mip were investigated in adrimycin-induced nephropathy (AN mice. The effect and mechanism of IL-17 on podocyte were explored in cultured podocytes. Results: The proportion of Th17 cells in peripheral blood mononuclear cells, the amount of IL-17 in serum and kidney cortical homogenates, and the expression of IL-17R and c-mip in glomerular podocyte were increased obviously in AN mice. In cultured podocytes, recombinant IL-17 led to an induction of apoptosis and cytoskeletal disorganization, an overproduction of c-mip while down-regulation of phosphor-nephrin, and an increased binding of c-mip to NF-κB/RelA. Silence of c-mip prevented podocyte apoptosis and reduction of phosphor-nephrin by prompting nuclear translocation of NF-κB/RelA in IL-17 treated cells. Persistent activation of NF-κB up-regulated pro-survival protein Bcl-2 and decreased podocyte apoptosis, but had no effect on phosphor-nephrin level. Conclusion: These findings demonstrated that induction of IL-17 released by Th17 cells plays a key role in podocytopathy most likely through down-regulation of phosphor-nephrin and Bcl-2 level via overproduction of c-mip.

  6. Protective role of free and quercetin-loaded nanoemulsion against damage induced by intracerebral haemorrhage in rats

    Science.gov (United States)

    Galho, A. R.; Cordeiro, M. F.; Ribeiro, S. A.; Marques, M. S.; Antunes, M. F. D.; Luz, D. C.; Hädrich, G.; Muccillo-Baisch, A. L.; Barros, D. M.; Lima, J. V.; Dora, C. L.; Horn, A. P.

    2016-04-01

    Intracerebral haemorrhage (ICH) is a worldwide public health problem. Experimental studies have shown that oxidative stress plays an important role in the pathogenesis of ICH and could represent a target for its treatment. However, the blood-brain barrier is an obstacle to be overcome, as it hampers the administration of compounds to the central nervous system. In this study, we compared the effects of a quercetin-loaded nanoemulsion (QU-N) with the free form of the drug (QU-SP) in a collagenase-induced ICH rat model. Quercetin (QU) is a polyphenol that has an antioxidant effect in vitro, but due to its high lipophilicity, it has low bioavailability in vivo. In this study, animals submitted or not to ICH were treated with a single intraperitoneal QU dose (free or nanoemulsion) of 30 mg kg-1. Motor assessment was evaluated by the open field, foot fault and beam walking behavioural tests. 72 h after surgery the haematoma size was evaluated and biochemical measurements were performed. Animals treated with QU-N had a significant improvement in the beam walking and open field tests. Also, QU-N was able to reduce the size of the haematoma, preserving the activity of glutathione S-transferase (GST), increasing GSH content, and the total antioxidant capacity. QU-SP recovered locomotor activity and increased the GSH content and the total antioxidant capacity. Thus, it can be observed that QU presented antioxidant activity in both formulations, but the incorporation into nanoemulsions increased its antioxidant effect, which was reflected in the improvement of the motor skills and in the haematoma size decrement. These results suggest that the nanoemulsion containing QU developed in this study could be promising for future studies on treatments for ICH.

  7. Human CD14 mediates recognition and phagocytosis of apoptotic cells.

    Science.gov (United States)

    Devitt, A; Moffatt, O D; Raykundalia, C; Capra, J D; Simmons, D L; Gregory, C D

    1998-04-02

    Cells undergoing programmed cell death (apoptosis) are cleared rapidly in vivo by phagocytes without inducing inflammation. Here we show that the glycosylphosphatidylinositol-linked plasma-membrane glycoprotein CD14 on the surface of human macrophages is important for the recognition and clearance of apoptotic cells. CD14 can also act as a receptor that binds bacterial lipopolysaccharide (LPS), triggering inflammatory responses. Overstimulation of CD14 by LPS can cause the often fatal toxic-shock syndrome. Here we show that apoptotic cells interact with CD14, triggering phagocytosis of the apoptotic cells. This interaction depends on a region of CD14 that is identical to, or at least closely associated with, a region known to bind LPS. However, apoptotic cells, unlike LPS, do not provoke the release of pro-inflammatory cytokines from macrophages. These results indicate that clearance of apoptotic cells is mediated by a receptor whose interactions with 'non-self' components (LPS) and 'self' components (apoptotic cells) produce distinct macrophage responses.

  8. The familial Parkinson's disease gene DJ-1 (PARK7) is expressed in red cells and plays a role in protection against oxidative damage.

    Science.gov (United States)

    Xu, Xiuling; Martin, Florent; Friedman, Jeffrey S

    2010-10-15

    The antioxidant enzyme manganese superoxide dismutase (SOD2) serves as the primary defense against mitochondrial superoxide. Impaired SOD2 activity in murine hematopoietic cells affects erythroid development, resulting in anemia characterized by intra-mitochondrial iron deposition, reticulocytosis and shortened red cell life span. Gene expression profiling of normal and SOD2 deficient erythroblasts identified the Parkinson's disease locus DJ-1 (Park7) as a differentially expressed transcript. To investigate the role of DJ-1 in hematopoietic cell development and protection against oxidative stress caused by Sod2 loss, we evaluated red cell parameters, reticulocyte count, red cell turnover and reactive oxygen species production in DJ-1 knockout animals and chimeric animals lacking both SOD2 and DJ-1 in hematopoietic cells generated by fetal liver transplantation. We also investigated DJ-1 protein expression in primary murine erythroid and erythroleukemia cells (MEL). Loss of DJ-1 exacerbates the phenotype of SOD2 deficiency, increasing reticulocyte count and decreasing red cell survival. Using MEL cells, we show that DJ-1 is up-regulated at the protein level during erythroid differentiation. These results indicate that DJ-1 plays a physiologic role in protection of erythroid cells from oxidant damage, a function unmasked in the context of oxidative stress.

  9. SATB1 Mediates Long-Range Chromatin Interactions: A Dual Regulator of Anti-Apoptotic BCL2 and Pro-Apoptotic NOXA Genes.

    Science.gov (United States)

    Yang, Yin; Wang, Zongdan; Sun, Luan; Shao, Lipei; Yang, Nan; Yu, Dawei; Zhang, Xin; Han, Xiao; Sun, Yujie

    2015-01-01

    Aberrant expression of special AT-rich binding protein 1 (SATB1), a global genomic organizer, has been associated with various cancers, which raises the question of how higher-order chromatin structure contributes to carcinogenesis. Disruption of apoptosis is one of the hallmarks of cancer. We previously demonstrated that SATB1 mediated specific long-range chromosomal interactions between the mbr enhancer located within 3'-UTR of the BCL2 gene and the promoter to regulate BCL2 expression during early apoptosis. In the present study, we used chromosome conformation capture (3C) assays and molecular analyses to further investigate the function of the SATB1-mediated higher-order chromatin structure in co-regulation of the anti-apoptotic BCL2 gene and the pro-apoptotic NOXA gene located 3.4Mb downstream on Chromosome 18. We demonstrated that the mbr enhancer spatially juxtaposed the promoters of BCL2 and NOXA genes through SATB1-mediated chromatin-loop in Jurkat cells. Decreased SATB1 levels switched the mbr-BCL2 loop to mbr-NOXA loop, and thus changed expression of these two genes. The SATB1-mediated dynamic switch of the chromatin loop structures was essential for the cooperative expression of the BCL2 and NOXA genes in apoptosis. Notably, the role of SATB1 was specific, since inhibition of SATB1 degradation by caspase-6 inhibitor or caspase-6-resistant SATB1 mutant reversed expression of BCL-2 and NOXA in response to apoptotic stimulation. This study reveals the critical role of SATB1-organized higher-order chromatin structure in regulating the dynamic equilibrium of apoptosis-controlling genes with antagonistic functions and suggests that aberrant SATB1 expression might contribute to cancer development by disrupting the co-regulated genes in apoptosis pathways.

  10. Roles of MgO release from polyethylene glycol 6000-based solid dispersions on microenvironmental pH, enhanced dissolution and reduced gastrointestinal damage of telmisartan.

    Science.gov (United States)

    Tran, Phuong Ha-Lien; Tran, Thao Truong-Dinh; Lee, Seung Aeon; Nho, Vo Hong; Chi, Sang-Cheol; Lee, Beom-Jin

    2011-05-01

    The roles of magnesium oxide (MgO) release from solid dispersions (SDs) in simulated gastric fluid (SGF), simulated intestinal fluid (SIF) and water were investigated to elucidate the enhanced dissolution and reduced intestinal damages of telmisartan as a model drug. The polyethylene glycol 6000 (PEG 6000) was used to prepare the SDs. Three SDs were prepared: SD1 (PEG, MgO, TEL), SD2 (PEG 6000, TEL), SD3 (MgO, TEL). The physical mixture (PM) consisting of SD2 and MgO was also prepared. A binary SD without MgO (SD2) was also prepared for comparison in microenvironmental pH (pH(M)) modulation. The faster MgO released, the less control of pH(M) and the less enhanced dissolution of TEL were in consequences. SD3 increased dissolution in SIF and water (about 67%). Interestingly, ternary SD1 showed almost complete dissolution in all three media but dissolution of PM was the lowest due to the fast release of MgO and poor modulation of pH(M). MgO did not change the drug crystallinity but did have a strong molecular interaction with the drug. Additionally, the SD3-bearing tablet quickly increased pH(M) but then gradually decreased due to faster release of MgO while the SD1-bearing tablet gradually increased pH(M) at all fractional dimensions of the tablet by the MgO slowly released. The pH(M) of PM-bearing tablets was not varied as a function of time. Thus, the MgO-bearing SD1 also minimized gastrointestinal tissue damage caused by the model drug.

  11. Low expression of pro-apoptotic Bcl-2 family proteins sets the apoptotic threshold in Waldenström macroglobulinemia.

    Science.gov (United States)

    Gaudette, B T; Dwivedi, B; Chitta, K S; Poulain, S; Powell, D; Vertino, P; Leleu, X; Lonial, S; Chanan-Khan, A A; Kowalski, J; Boise, L H

    2016-01-28

    Waldenström macroglobulinemia (WM) is a proliferative disorder of IgM-secreting, lymphoplasmacytoid cells that inhabit the lymph nodes and bone marrow. The disease carries a high prevalence of activating mutations in MyD88 (91%) and CXCR4 (28%). Because signaling through these pathways leads to Bcl-xL induction, we examined Bcl-2 family expression in WM patients and cell lines. Unlike other B-lymphocyte-derived malignancies, which become dependent on expression of anti-apoptotic proteins to counter expression of pro-apoptotic proteins, WM samples expressed both pro- and anti-apoptotic Bcl-2 proteins at low levels similar to their normal B-cell and plasma cell counterparts. Three WM cell lines expressed pro-apoptotic Bcl-2 family members Bim or Bax and Bak at low levels, which determined their sensitivity to inducers of intrinsic apoptosis. In two cell lines, miR-155 upregulation, which is common in WM, was responsible for the inhibition of FOXO3a and Bim expression. Both antagonizing miR-155 to induce Bim and proteasome inhibition increased the sensitivity to ABT-737 in these lines indicating a lowering of the apoptotic threshold. In this manner, treatments that increase pro-apoptotic protein expression increase the efficacy of agents treated in combination in addition to direct killing.

  12. Impaired phagocytosis of apoptotic cells causes accumulation of bone marrow-derived macrophages in aged mice

    Science.gov (United States)

    Kim, Ok-Hee; Kim, Hyojung; Kang, Jinku; Yang, Dongki; Kang, Yu-Hoi; Lee, Dae Ho; Cheon, Gi Jeong; Park, Sang Chul; Oh, Byung-Chul

    2017-01-01

    Accumulation of tissue macrophages is a significant characteristic of disease-associated chronic inflammation, and facilitates the progression of disease pathology. However, the functional roles of these bone marrow-derived macrophages (BMDMs) in aging are unclear. Here, we identified age-dependent macrophage accumulation in the bone marrow, showing that aging significantly increases the number of M1 macrophages and impairs polarization of BMDMs. We found that age-related dysregulation of BMDMs is associated with abnormal overexpression of the anti-inflammatory interleukin-10. BMDM dysregulation in aging impairs the expression levels of pro-inflammatory cytokines and genes involved in B-cell maturation and activation. Phagocytosis of apoptotic Jurkat cells by BMDMs was reduced because of low expression of phagocytic receptor CD14, indicating that increased apoptotic cells may result from defective phagocytosis of apoptotic cells in the BM of aged mice. Therefore, CD14 may represent a promising target for preventing BMDM dysregulation, and macrophage accumulation may provide diagnostic and therapeutic clues. PMID:27866511

  13. BAG1: the guardian of anti-apoptotic proteins in acute myeloid leukemia.

    Science.gov (United States)

    Aveic, Sanja; Pigazzi, Martina; Basso, Giuseppe

    2011-01-01

    BCL2 associated Athano-Gene 1 (BAG1) is a multifunctional protein that has been described to be involved in different cell processes linked to cell survival. It has been reported as deregulated in diverse cancer types. Here, BAG1 protein was found highly expressed in children with acute myeloid leukemia at diagnosis, and in a cohort of leukemic cell lines. A silencing approach was used for determining BAG1's role in AML, finding that its down-regulation decreased expression of BCL2, BCL-XL, MCL1, and phospho-ERK1/2, all proteins able to sustain leukemia, without affecting the pro-apoptotic protein BAX. BAG1 down-regulation was also found to increase expression of BAG3, whose similar activity was able to compensate the loss of function of BAG1. BAG1/BAG3 co-silencing caused an enhanced cell predisposition to death in cell lines and also in primary AML cultures, affecting the same proteins. Cell death was CASPASE-3 dependent, was accompanied by PARP cleavage and documented by an increased release of pro-apoptotic molecules Smac/DIABLO and Cytochrome c. BAG1 was found to directly maintain BCL2 and to protect MCL1 from proteasomal degradation by controlling USP9X expression, which appeared to be its novel target. Finally, BAG1 was found able to affect leukemia cell fate by influencing the expression of anti-apoptotic proteins crucial for AML maintenance.

  14. BAG1: the guardian of anti-apoptotic proteins in acute myeloid leukemia.

    Directory of Open Access Journals (Sweden)

    Sanja Aveic

    Full Text Available BCL2 associated Athano-Gene 1 (BAG1 is a multifunctional protein that has been described to be involved in different cell processes linked to cell survival. It has been reported as deregulated in diverse cancer types. Here, BAG1 protein was found highly expressed in children with acute myeloid leukemia at diagnosis, and in a cohort of leukemic cell lines. A silencing approach was used for determining BAG1's role in AML, finding that its down-regulation decreased expression of BCL2, BCL-XL, MCL1, and phospho-ERK1/2, all proteins able to sustain leukemia, without affecting the pro-apoptotic protein BAX. BAG1 down-regulation was also found to increase expression of BAG3, whose similar activity was able to compensate the loss of function of BAG1. BAG1/BAG3 co-silencing caused an enhanced cell predisposition to death in cell lines and also in primary AML cultures, affecting the same proteins. Cell death was CASPASE-3 dependent, was accompanied by PARP cleavage and documented by an increased release of pro-apoptotic molecules Smac/DIABLO and Cytochrome c. BAG1 was found to directly maintain BCL2 and to protect MCL1 from proteasomal degradation by controlling USP9X expression, which appeared to be its novel target. Finally, BAG1 was found able to affect leukemia cell fate by influencing the expression of anti-apoptotic proteins crucial for AML maintenance.

  15. Dysregulation of Apoptotic Signaling in Cancer: Molecular Mechanisms and Therapeutic Opportunities

    Science.gov (United States)

    Plati, Jessica; Bucur, Octavian; Khosravi-Far, Roya

    2010-01-01

    Apoptosis is a tightly regulated cell suicide program that plays an essential role in the maintenance of tissue homeostasis by eliminating unnecessary or harmful cells. Defects in this native defense mechanism promote malignant transformation and frequently confer chemoresistance to transformed cells. Indeed, the evasion of apoptosis has been recognized as a hallmark of cancer. Given that multiple mechanisms function at many levels to orchestrate the regulation of apoptosis, a multitude of opportunities for apoptotic dysregulation are present within the intricate signaling network of cell. Several of the molecular mechanisms by which cancer cells are protected from apoptosis have been elucidated. These advances have facilitated the development of novel apoptosis-inducing agents that have demonstrated single-agent activity against various types of cancers cells and/or sensitized resistant cancer cells to conventional cytotoxic therapies. Herein, we will highlight several of the central modes of apoptotic dysregulation found in cancer. We will also discuss several therapeutic strategies that aim to reestablish the apoptotic response, and thereby eradicate cancer cells, including those that demonstrate resistance to traditional therapies. PMID:18459149

  16. SIGN-R1 and complement factors are involved in the systemic clearance of radiation-induced apoptotic cells in whole-body irradiated mice

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jin-Yeon; Loh, SoHee; Cho, Eun-hee [Department of Biomedical Science & Technology, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul, 143-701 (Korea, Republic of); Choi, Hyeong-Jwa [Division of Radiation Effect, Korea Institute of Radiological and Medical Sciences, 215-4, 75 Nowon gil Nowon-Gu, Seoul, 139-706 (Korea, Republic of); Na, Tae-Young [College of Pharmacy, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-741 (Korea, Republic of); Nemeno, Judee Grace E.; Lee, Jeong Ik [Regenerative Medicine Laboratory, Department of Veterinary Medicine, College of Veterinary Medicine, Konkuk University, Seoul, 143-701 (Korea, Republic of); Yoon, Taek Joon [Department of Food and Nutrition, Yuhan College, Bucheon, Gyeonggi-do, 422-749 (Korea, Republic of); Choi, In-Soo [Department of Infectious Diseases, College of Veterinary Medicine, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul, 143-701 (Korea, Republic of); Lee, Minyoung [Division of Radiation Effect, Korea Institute of Radiological and Medical Sciences, 215-4, 75 Nowon gil Nowon-Gu, Seoul, 139-706 (Korea, Republic of); Lee, Jae-Seon [Department of Biomedical Sciences, College of Medicine, Inha University, Incheon, 400-712 (Korea, Republic of); Kang, Young-Sun, E-mail: kangys1967@naver.com [Department of Biomedical Science & Technology, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul, 143-701 (Korea, Republic of); Department of Veterinary Pharmacology and Toxicology, College of Veterinary Medicine, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul, 143-701 (Korea, Republic of)

    2015-08-07

    Although SIGN-R1-mediated complement activation pathway has been shown to enhance the systemic clearance of apoptotic cells, the role of SIGN-R1 in the clearance of radiation-induced apoptotic cells has not been characterized and was investigated in this study. Our data indicated that whole-body γ-irradiation of mice increased caspase-3{sup +} apoptotic lymphocyte numbers in secondary lymphoid organs. Following γ-irradiation, SIGN-R1 and complements (C4 and C3) were simultaneously increased only in the mice spleen tissue among the assessed tissues. In particular, C3 was exclusively activated in the spleen. The delayed clearance of apoptotic cells was markedly prevalent in the spleen and liver of SIGN-R1 KO mice, followed by a significant increase of CD11b{sup +} cells. These results indicate that SIGN-R1 and complement factors play an important role in the systemic clearance of radiation-induced apoptotic innate immune cells to maintain tissue homeostasis after γ-irradiation. - Highlights: • Splenic SIGN-R1{sup +} macrophages are activated after γ-irradiation. • C3 and C4 levels increased and C3 was activated in the spleen after γ-irradiation. • SIGN-R1 mediated the systemic clearance of radiation-induced apoptotic cells in spleen and liver.

  17. GESTATIONAL DIABETES MELLITUS ALTERS APOPTOTIC AND INFLAMMATORY GENE EXPRESSION OF TROPHOBASTS FROM HUMAN TERM PLACENTA

    Science.gov (United States)

    MAGEE, Thomas R.; ROSS, Michael G.; WEDEKIND, Lauren; DESAI, Mina; KJOS, Siri; BELKACEMI, Louiza

    2014-01-01

    AIM Increased placental growth secondary to reduced apoptosis may contribute to the development of macrosomia in GDM pregnancies. We hypothesize that reduced apoptosis in GDM placentas is caused by dysregulation of apoptosis related genes from death receptors or mitochondrial pathway or both to enhance placental growth in GDM pregnancies. METHODS Newborn and placental weights from women with no pregnancy complications (controls; N=5), or with GDM (N=5) were recorded. Placental villi from both groups were either fixed for TUNEL assay, or snap frozen for gene expression analysis by apoptosis PCR microarrays and qPCR. RESULTS Maternal, placental and newborn weights were significantly higher in the GDM group vs. Controls. Apoptotic index of placentas from the GDM group was markedly lower than the Controls. At a significant threshold of 1.5, seven genes (BCL10, BIRC6, BIRC7, CASP5, CASP8P2, CFLAR, and FAS) were down regulated, and 13 genes (BCL2, BCL2L1, BCL2L11, CASP4, DAPK1, IκBκE, MCL1, NFκBIZ, NOD1, PEA15, TNF, TNFRSF25, and XIAP) were unregulated in the GDM placentas. qPCR confirmed the consistency of the PCR microarray. Using Western blotting we found significantly decreased placental pro-apoptotic FAS receptor and FAS ligand (FASL), and increased mitochondrial anti-apoptotic BCL2 post GDM insult. Notably, caspase-3, which plays a central role in the execution-phase of apoptosis, and its substrate poly (ADP-ribose) polymerase (PARP) were significantly down regulated in GDM placentas, as compared to non-diabetic Control placentas. CONCLUSION . Women with gestational diabetes (GDM) are at increased risk for having macrosomic newborns, and larger placentas with reduced apoptosis. Decreased apoptosis subsequent to alterations in apoptotic and inflammatory genes may promote elevated weight in the GDM placentas. PMID:24768206

  18. H pylori receptor MHC class Ⅱ contributes to the dynamic gastric epithelial apoptotic response

    Institute of Scientific and Technical Information of China (English)

    David A Bland; Giovanni Suarez; Ellen J Beswick; Johanna C Sierra; Victor E Reyes

    2006-01-01

    AIM: To investigate the role of MHC class Ⅱ in the modulation of gastric epithelial cell apoptosis induced by H pylori infection.METHODS: After stimulating a human gastric epithelial cell line with bacteria or agonist antibodies specific for MHC class Ⅱ and CD95, the quantitation of apoptotic and anti-apoptotic events, including caspase activation,BCL-2 activation, and FADD recruitment, was performed with a fluorometric assay, a cytometric bead array, and confocal microscopy, respectively.RESULTS: Pretreatment of N87 cells with the anti-MHC class Ⅱ IgM antibody RFD1 resulted in a reduction in global caspase activation at 24 h of H pylori infection.When caspase 3 activation was specifically measured,crosslinking of MHC class Ⅱ resulted in a marked reduced caspase activation, while simple ligation of MHC class Ⅱ did not. Crosslinking of MHC class Ⅱ also resulted in an increased activation of the anti-apoptosis molecule BCL-2 compared to simple ligation. Confocal microscope analysis demonstrated that the pretreatment of gastric epithelial cells with a crosslinking anti-MHC class Ⅱ IgM blocked the recruitment of FADD to the cell surface.CONCLUSION: The results presented here demonstrate that the ability of MHC class Ⅱ to modulate gastric epithelial apoptosis is at least partially dependent on its crosslinking. Furthermore, while previous research has demonstrated that MHC class Ⅱ signaling can be proapoptotic during extended ligation, we have shown that the crosslinking of this molecule has anti-apoptotic effects during the earlier time points of H pylori infection.This effect is possibly mediated by the ability of MHC class Ⅱ to modulate the activation of the pro-apoptotic receptor Fas by blocking the recruitment of the accessory molecule FADD, and this delay in apoptosis induction could allow for prolonged cytokine secretion by H pyloriinfected gastric epithelial cells.

  19. Resveratrol engages selective apoptotic signals in gastric adenocarcinoma cells

    Institute of Scientific and Technical Information of China (English)

    William L Riles; Jason Erickson; Sanjay Nayyar; Mary Jo Atten; Bashar M Attar; Oksana Holian

    2006-01-01

    AIM: To investigate the intracellular apoptotic signals engaged by resveratrol in three gastric adenocarcinoma cancer cell lines, two of which (AGS and SNU-1) express p53 and one (KATO-Ⅲ) with deleted p53.METHODS: Nuclear fragmentation was used to quantitate apoptotic cells; caspase activity was determined by photometric detection of cleaved substrates; formation of oxidized cytochrome C was used to measure cytochrome C activity, and Western blot analysis was used to determine protein expression.RESULTS: Gastric cancer cells, irrespective of their p53 status, responded to resveratrol with fragmentation of DNA and cleavage of nuclear lamins A and B and PARP, Resveratrol, however, has no effect on mitochondria-associated apoptotic proteins Bcl-2, Bclxl, Bax, Bid or Smac/Diablo, and did not promote subcellular redistribution of cytochrome C, indicating that resveratrol-induced apoptosis of gastric carcinoma cells does not require breakdown of mitochondrial membrane integrity. Resveratrol up-regulated p53 protein in SNU-1 and AGS cells but there was a difference in response of intracellular apoptotic signals between these cell lines.SNU-1 cells responded to resveratrol treatment with down-regulation of survivin, whereas in AGS and KATO-Ⅲ cells resveratrol stimulated caspase 3 and cytochrome C oxidase activities.CONCLUSION: These findings indicate that even within a specific cancer the intracellular apoptotic signals engaged by resveratrol are cell type dependent and suggest that such differences may be related to differentiation or lack of differentiation of these cells.

  20. Epigallocatechin-gallate (EGCG) regulates autophagy in human retinal pigment epithelial cells: A potential role for reducing UVB light-induced retinal damage

    Energy Technology Data Exchange (ETDEWEB)

    Li, Chao-Peng; Yao, Jin; Tao, Zhi-Fu; Li, Xiu-Miao; Jiang, Qin, E-mail: jqin710@vip.sina.com; Yan, Biao, E-mail: yanbiao1982@hotmail.com

    2013-09-06

    Highlights: •UVB irradiation induces RPE autophagy. •EGCG treatment represses UVB-mediated autophagy. •EGCG regulates UVB-mediated autophagy through mTOR signaling pathway. •EGCG sensitizes RPE cells to UVB-induced damage in an autophagy-dependent manner. -- Abstract: Autophagy is an intracellular catabolic process involved in protein and organelle degradation via the lysosomal pathway that has been linked in the pathogenesis of age-related macular degeneration (AMD). UVB irradiation-mediated degeneration of the macular retinal pigment epithelial (RPE) cells is an important hallmark of AMD, which is along with the change in RPE autophagy. Thus, pharmacological manipulation of RPE autophagy may offer an alternative therapeutic target in AMD. Here, we found that epigallocatechin-3-gallate (EGCG), a polyphenolic compound from green tea, plays a regulatory role in UVB irradiation-induced autophagy in RPE cells. UVB irradiation results in a marked increase in the amount of LC3-II protein in a dose-dependent manner. EGCG administration leads to a significant reduction in the formation of LC3-II and autophagosomes. mTOR signaling activation is required for EGCG-induced LC3-II formation, as evidenced by the fact that EGCG-induced LC3-II formation is significantly impaired by rapamycin administration. Moreover, EGCG significantly alleviates the toxic effects of UVB irradiation on RPE cells in an autophagy-dependent manner. Collectively, our study reveals a novel role of EGCG in RPE autophagy. EGCG may be exploited as a potential therapeutic reagent for the treatment of pathological conditions associated with abnormal autophagy.

  1. Endoplasmic Reticulum Stress Induces the Early Appearance of Pro-apoptotic and Anti-apoptotic Proteins in Neurons of Five Familial Alzheimer's Disease Mice

    Institute of Scientific and Technical Information of China (English)

    Hui Shen; Xiao-Dong Pan; Jing Zhang; Yu-Qi Zeng; Meng Zhou; Lu-Meng Yang; Bing Ye

    2016-01-01

    Background:Amyloid β (Aβ) deposits and the endoplasmic reticulum stress (ERS) are both well established in the development and progression ofAlzheimer's disease (AD).However,the mechanism and role of Aβ-induced ERS in AD-associated pathological progression remain to be elucidated.Methods:The five familial AD (5 ×FAD) mice and wild-type (WT) mice aged 2,7,and 12 months were used in the present study.Morris water maze test was used to evaluate their cognitive performance.Immunofluorescence and Western blot analyses were used to examine the dynamic changes of pro-apoptotic (CCAAT/enhancer-binding protein homologous protein [CHOP] and cleaved caspase-12) and anti-apoptotic factors (chaperone glucose-regulated protein [GRP] 78 and endoplasmic reticulum-associated protein degradation-associated ubiquitin ligase synovial apoptosis inhibitor 1 [SYVN1]) in the ERS-associated unfolded protein response (UPR) pathway.Results:Compared with age-matched WT mice,5 ×FAD mice showed higher cleaved caspase-3,lower neuron-positive staining at the age of 12 months,but earlier cognitive deficit at the age of 7 months (all P < 0.05).Interestingly,for 2-month-old 5×FAD mice,the related proteins involved in the ERS-associated UPR pathway,including CHOP,cleaved caspase-12,GRP 78,and SYVN1,were significantly increased when compared with those in age-matched WT mice (all P < 0.05).Moreover,ERS occurred mainly in neurons,not in astrocytes.Conclusions:These findings suggest that compared with those of age-matched WT mice,ERS-associated pro-apoptotic and anti-apoptoticproteins are upregulated in 2-month-old 5×FAD mice,consistent with intracellular Aβ aggregation in neurons.

  2. DnaK dependence of mutant ethanol oxidoreductases evolved for aerobic function and protective role of the chaperone against protein oxidative damage in Escherichia coli

    Science.gov (United States)

    Echave, Pedro; Esparza-Cerón, M. Angel; Cabiscol, Elisa; Tamarit, Jordi; Ros, Joaquim; Membrillo-Hernández, Jorge; Lin, E. C. C.

    2002-01-01

    The adhE gene of Escherichia coli encodes a multifunctional ethanol oxidoreductase (AdhE) that catalyzes successive reductions of acetyl-CoA to acetaldehyde and then to ethanol reversibly at the expense of NADH. Mutant JE52, serially selected for acquired and improved ability to grow aerobically on ethanol, synthesized an AdhEA267T/E568K with two amino acid substitutions that sequentially conferred improved catalytic properties and stability. Here we show that the aerobic growth ability on ethanol depends also on protection of the mutant AdhE against metal-catalyzed oxidation by the chaperone DnaK (a member of the Hsp70 family). No DnaK protection of the enzyme is evident during anaerobic growth on glucose. Synthesis of DnaK also protected E. coli from H2O2 killing under conditions when functional AdhE is not required. Our results therefore suggest that, in addition to the known role of protecting cells against heat stress, DnaK also protects numerous kinds of proteins from oxidative damage. PMID:11917132

  3. Poly(ADP-ribosylation acts in the DNA demethylation of mouse primordial germ cells also with DNA damage-independent roles.

    Directory of Open Access Journals (Sweden)

    Fabio Ciccarone

    Full Text Available Poly(ADP-ribosylation regulates chromatin structure and transcription driving epigenetic events. In particular, Parp1 is able to directly influence DNA methylation patterns controlling transcription and activity of Dnmt1. Here, we show that ADP-ribose polymer levels and Parp1 expression are noticeably high in mouse primordial germ cells (PGCs when the bulk of DNA demethylation occurs during germline epigenetic reprogramming in the embryo. Notably, Parp1 activity is stimulated in PGCs even before its participation in the DNA damage response associated with active DNA demethylation. We demonstrate that PARP inhibition impairs both genome-wide and locus-specific DNA methylation erasure in PGCs. Moreover, we evidence that impairment of PARP activity causes a significant reduction of expression of the gene coding for Tet1 hydroxylases involved in active DNA demethylation. Taken together these results demonstrate new and adjuvant roles of poly(ADP-ribosylation during germline DNA demethylation and suggest its possible more general involvement in genome reprogramming.

  4. Role of genetic polymorphisms of CYP1A1, CYP3A5, CYP2C9, CYP2D6, and PON1 in the modulation of DNA damage in workers occupationally exposed to organophosphate pesticides

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Satyender [Division of Biochemistry and Biotechnology, National Centre for Disease Control 22, Sham Nath Marg, Delhi-110054 (India); Kumar, Vivek [Environmental Biochemistry and Molecular Biology laboratory, Department of Biochemistry, University College of Medical Sciences and GTB Hospital, University of Delhi, Dilshad Garden, Delhi-110095 (India); Vashisht, Kapil; Singh, Priyanka [Division of Biochemistry and Biotechnology, National Centre for Disease Control 22, Sham Nath Marg, Delhi-110054 (India); Banerjee, Basu Dev, E-mail: banerjeebd@hotmail.com [Environmental Biochemistry and Molecular Biology laboratory, Department of Biochemistry, University College of Medical Sciences and GTB Hospital, University of Delhi, Dilshad Garden, Delhi-110095 (India); Rautela, Rajender Singh; Grover, Shyam Sunder; Rawat, Devendra Singh; Pasha, Syed Tazeen [Division of Biochemistry and Biotechnology, National Centre for Disease Control 22, Sham Nath Marg, Delhi-110054 (India); Jain, Sudhir Kumar [Centre for Epidemiology and Parasitic Diseases, National Centre for Disease Control 22, Sham Nath Marg, Delhi-110054 (India); Rai, Arvind [Division of Biochemistry and Biotechnology, National Centre for Disease Control 22, Sham Nath Marg, Delhi-110054 (India)

    2011-11-15

    Organophosphate pesticides (OPs) are primarily metabolized by several xenobiotic metabolizing enzymes (XMEs). Very few studies have explored genetic polymorphisms of XMEs and their association with DNA damage in pesticide-exposed workers. The present study was designed to determine the role of genetic polymorphisms of CYP1A1, CYP3A5, CYP2C9, CYP2D6, and PON1 in the modulation of DNA damage in workers occupationally exposed to OPs. We examined 284 subjects including 150 workers occupationally exposed to OPs and 134 normal healthy controls. The DNA damage was evaluated using the alkaline comet assay and genotyping was done using PCR-RFLP. The results revealed that the PONase activity toward paraoxonase and AChE activity was found significantly lowered in workers as compared to control subjects (p < 0.001). Workers showed significantly higher DNA damage compared to control subjects (14.37 {+-} 2.15 vs. 6.24 {+-} 1.37 tail% DNA, p < 0.001). Further, the workers with CYP2D6*3 PM and PON1 (QQ and MM) genotypes were found to have significantly higher DNA damage when compared to other genotypes (p < 0.05). In addition, significant increase in DNA damage was also observed in workers with concomitant presence of certain CYP2D6 and PON1 (Q192R and L55M) genotypes which need further extensive studies. In conclusion, the results indicate that the PON1 and CYP2D6 genotypes can modulate DNA damage elicited by some OPs possibly through gene-environment interactions. -- Highlights: Black-Right-Pointing-Pointer Role of CYP1A1, CYP3A5, CYP2C, CYP2D6 and PON1 genotypes on DNA damage. Black-Right-Pointing-Pointer Workers exposed to some OPs demonstrated increased DNA damage. Black-Right-Pointing-Pointer CYP2D6 *3 PM and PON1 (Q192R and L55M) genotypes are associated with DNA damage. Black-Right-Pointing-Pointer Concomitant presence of certain CYP2D6 and PON1 genotypes can increase DNA damage.

  5. PARP-1 modulates amyloid beta peptide-induced neuronal damage.

    Directory of Open Access Journals (Sweden)

    Sara Martire

    Full Text Available Amyloid beta peptide (Aβ causes neurodegeneration by several mechanisms including oxidative stress, which is known to induce DNA damage with the consequent activation of poly (ADP-ribose polymerase (PARP-1. To elucidate the role of PARP-1 in the neurodegenerative process, SH-SY5Y neuroblastoma cells were treated with Aβ25-35 fragment in the presence or absence of MC2050, a new PARP-1 inhibitor. Aβ25-35 induces an enhancement of PARP activity which is prevented by cell pre-treatment with MC2050. These data were confirmed by measuring PARP-1 activity in CHO cells transfected with amylod precursor protein and in vivo in brains specimens of TgCRND8 transgenic mice overproducing the amyloid peptide. Following Aβ25-35 exposure a significant increase in intracellular ROS was observed. These data were supported by the finding that Aβ25-35 induces DNA damage which in turn activates PARP-1. Challenge with Aβ25-35 is also able to activate NF-kB via PARP-1, as demonstrated by NF-kB impairment upon MC2050 treatment. Moreover, Aβ25-35 via PARP-1 induces a significant increase in the p53 protein level and a parallel decrease in the anti-apoptotic Bcl-2 protein. These overall data support the hypothesis of PARP-1 involvment in cellular responses induced by Aβ and hence a possible rationale for the implication of PARP-1 in neurodegeneration is discussed.

  6. An anti-apoptotic peptide improves survival in lethal total body irradiation.

    Science.gov (United States)

    McDunn, Jonathan E; Muenzer, Jared T; Dunne, Benjamin; Zhou, Anthony; Yuan, Kevin; Hoekzema, Andrew; Hilliard, Carolyn; Chang, Katherine C; Davis, Christopher G; McDonough, Jacquelyn; Hunt, Clayton; Grigsby, Perry; Piwnica-Worms, David; Hotchkiss, Richard S

    2009-05-15

    Cell penetrating peptides (CPPs) have been used to deliver the anti-apoptotic Bcl-xL-derived BH4 peptide to prevent injury-induced apoptosis both in vitro and in vivo. Here we demonstrate that the nuclear localization sequence (NLS) from the SV40 large T antigen has favorable properties for BH4 domain delivery to lymphocytes compared to sequences based on the HIV-1 TAT sequence. While both TAT-BH4 and NLS-BH4 protected primary human mononuclear cells from radiation-induced apoptotic cell death, TAT-BH4 caused persistent membrane damage and even cell death at the highest concentrations tested (5-10 microM) and correlated with in vivo toxicity as intravenous administration of TAT-BH4 caused rapid death. The NLS-BH4 peptide has significantly attenuated toxicity compared to TAT-BH4 and we established a dosing regimen of NLS-BH4 that conferred a significant survival advantage in a post-exposure treatment model of LD90 total body irradiation.

  7. Inhibition of mitochondria responsible for the anti-apoptotic effects of melatonin during ischemia-reperfusion

    Institute of Scientific and Technical Information of China (English)

    HAN Yi-xiang; ZHANG Sheng-hui; WANG Xi-ming; WU Jian-bo

    2006-01-01

    Objective: To investigate a possible mechanism responsible for anti-apoptotic effects of melatonin and provide theoretical evidences for clinical therapy. Methods: Ischemia-reperfusion mediated neuronal cell injury model was constructed in cerebellar granule neurons (CGNs) by deprivation of glucose, serum and oxygen in media. After ischemia, melatonin was added to the test groups to reach differential concentration during reperfusion. DNA fragmentation, mitochondrial transmembrane potential,mitochondrial cytochrome c release and caspase-3 activity were observed after subjecting cerebellar granule neurons to oxygen-glucose deprivation (OGD). Results: The results showed that OGD induced typical cell apoptosis change, DNA ladder and apoptosis-related alterations in mitochondrial functions including depression of mitochondrial transmembrane potential (its maximal protection ratio was 73.26%) and release of cytochrome c (its maximal inhibition ratio was 42.52%) and the subsequent activation of caspase-3 (its maximal protection ratio was 59.32%) in cytoplasm. Melatonin reduced DNA damage and inhibited release of mitochondrial cytochrome c and activation of caspase-3. Melatonin can strongly prevent the OGD-induced loss of the mitochondria membrane potential. Conclusion: Our findings suggested that the direct inhibition of mitochondrial pathway might essentially contribute to its anti-apoptotic effects in neuronal ischemia-reperfusion.

  8. Assessment of cytotoxic and apoptotic effects of benzaldehyde using different assays.

    Science.gov (United States)

    Ulker, Z; Alpsoy, L; Mihmanli, A

    2013-08-01

    Benzaldehyde (BA) occurs naturally in a number of plants, including cherry, fig and peach fruit and carnation flowers at therapeutic doses. In addition, it is used in cosmetics, personal care products and food as a preservative. In this study, we aimed to determine the cytotoxic and apoptotic effects of different concentrations of BA on cultured human lymphocytes using lactate dehydrogenase assay, cell proliferation (water-soluble tetrazolium salts-1) assay and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) test (apoptotic test) as a group of cytotoxicity tests at 6th and 24th h on human lymphocyte cell culture. The cytotoxicity increased when cells were treated with 10, 25 and 50 μg/mL concentrations of BA (p < 0.05). Moreover, treatment of the cells with the same concentrations significantly decreased the cell number at the 6th and 24th hours (p < 0.05). TUNEL assay results also show that the concentration of BA at 10, 25 and 50 μg/mL caused DNA damage significantly (p < 0.05). According to our results, the toxic and genotoxic effects of BA have to be further evaluated before using in cosmetic and food products.

  9. c-Myc dependent expression of pro-apoptotic Bim renders HER2-overexpressing breast cancer cells dependent on anti-apoptotic Mcl-1

    Directory of Open Access Journals (Sweden)

    Jézéquel Pascal

    2011-09-01

    Full Text Available Abstract Background Anti-apoptotic signals induced downstream of HER2 are known to contribute to the resistance to current treatments of breast cancer cells that overexpress this member of the EGFR family. Whether or not some of these signals are also involved in tumor maintenance by counteracting constitutive death signals is much less understood. To address this, we investigated what role anti- and pro-apoptotic Bcl-2 family members, key regulators of cancer cell survival, might play in the viability of HER2 overexpressing breast cancer cells. Methods We used cell lines as an in vitro model of HER2-overexpressing cells in order to evaluate how anti-apoptotic Bcl-2, Bcl-xL and Mcl-1, and pro-apoptotic Puma and Bim impact on their survival, and to investigate how the constitutive expression of these proteins is regulated. Expression of the proteins of interest was confirmed using lysates from HER2-overexpressing tumors and through analysis of publicly available RNA expression data. Results We show that the depletion of Mcl-1 is sufficient to induce apoptosis in HER2-overexpressing breast cancer cells. This Mcl-1 dependence is due to Bim expression and it directly results from oncogenic signaling, as depletion of the oncoprotein c-Myc, which occupies regions of the Bim promoter as evaluated in ChIP assays, decreases Bim levels and mitigates Mcl-1 dependence. Consistently, a reduction of c-Myc expression by inhibition of mTORC1 activity abrogates occupancy of the Bim promoter by c-Myc, decreases Bim expression and promotes tolerance to Mcl-1 depletion. Western blot analysis confirms that naïve HER2-overexpressing tumors constitutively express detectable levels of Mcl-1 and Bim, while expression data hint on enrichment for Mcl-1 transcripts in these tumors. Conclusions This work establishes that, in HER2-overexpressing tumors, it is necessary, and maybe sufficient, to therapeutically impact on the Mcl-1/Bim balance for efficient induction of

  10. Upregulation of Phagocytic Clearance of Apoptotic Cells by Autoimmune Regulator

    Institute of Scientific and Technical Information of China (English)

    石亮; 胡丽华; 李一荣

    2010-01-01

    To investigate the effect of autoimmune regulator(AIRE) on phagocytic clearance of apoptotic cells,a recombinant expression vector containing full-length human AIRE cDNA was transfected into 16HBE cells.After incubation with transfected 16HBE cells,engulfment of apoptotic HL-60 cells induced by camptothecin was detected by myeloperoxidase(MPO) staining.The change in the expression of Rac 1 in transfected 16HBE cells was determined by RT-PCR and Western blotting.The results showed that the phagocytosis perce...

  11. Modulating effect of lupeol on the expression pattern of apoptotic markers in 7, 12-dimethylbenz(a)anthracene induced oral carcinogenesis.

    Science.gov (United States)

    Manoharan, S; Palanimuthu, D; Baskaran, N; Silvan, S

    2012-01-01

    Apoptosis, also known as cell suicide or programmed cell death, removes unwanted and genetically damaged cells from the body. Evasion of apoptosis is one of the major characteristic features of rapidly proliferating tumor cells. Chemopreventive agents inhibit or suppress tumor formation through apoptotic induction in target tissues. The aim of the present study was to investigate the pro-apoptotic potential of lupeol during 7,12-dimethylbenz(a) anthracene (DMBA) induced hamster buccal pouch carcinogenesis. Topical application of 0.5% DMBA three times a week for 14 weeks in the buccal pouches of golden Syrian hamsters resulted in oral squamous cell carcinoma. The expression pattern of apoptotic markers was analyzed using immunohistochemistry (p53, Bcl-2, Bax) and ELISA reader (caspase 3 and 9). In the present study, 100% tumor formation with defects in apoptotic markerexpression pattern was noticed in hamsters treated with DMBA alone. Oral administration of lupeol at a dose of 50 mg/kg bw completely prevented the formation oral tumors as well as decreased the expression p53 and Bcl-2, while increasing the expression of Bax and the activities of caspase 3 and 9. The present study thus indicated that lupeol might inhibit DMBA-induced oral tumor formation through its pro-apoptotic potential in golden Syrian hamsters.

  12. Pro-apoptotic Gene PUMA and Tumor Therapy%促凋亡基因puma与肿瘤治疗

    Institute of Scientific and Technical Information of China (English)

    王明立

    2012-01-01

    p53上调凋亡调控因子(puma)是Bcl-2蛋白家族的促凋亡成员之一,是p53的下游靶基因,发挥作用却与p53的状态无关,可通过p53依赖和非依赖途径诱导细胞凋亡.puma在多种肿瘤组织中低表达,与肿瘤的发生密切相关.puma与放疗、化疗有协同作用,上调puma可以增强肿瘤细胞对放化疗的敏感性,而puma缺失则可降低放化疗对正常细胞的损伤.随着研究的深入,puma有望成为肿瘤治疗的新靶点.%p53 upregulated modulator of apoptosis( PUMA )is a pro-apoptotic protein member of the Bcl-2 family. PUMA is the down-stream target gene of p53, playing the role regardless of the state of p53. PUMA induces apoptosis via both p53-dependent and p53-independent mechanisms. PUMA has low expression in a variety of tumor tissues and is closely related with tumor occurrence. PUMA has a syner-gistic effect with radiotherapy and chemotherapy. Upregulation of PUMA expression could enhance the sensitivity of tumor cells to radiotherapy and chemotherapy, while the deletion of PUMA could reduce the damage of radiotherapy and chemotherapy to normal cells. PUMA is expected to be a new target of cancer therapy along with the further studies.

  13. Histone demethylase Jmjd3 regulates osteoblast apoptosis through targeting anti-apoptotic protein Bcl-2 and pro-apoptotic protein Bim.

    Science.gov (United States)

    Yang, Di; Okamura, Hirohiko; Teramachi, Jumpei; Haneji, Tatsuji

    2016-04-01

    Posttranslational modifications including histone methylation regulate gene transcription through directly affecting the structure of chromatin. Trimethylation of histone H3K27 (H3K27me3) contributes to gene silencing and the histone demethylase Jumonji domain-containing 3 (Jmjd3) specifically removes the methylation of H3K27me3, followed by the activation of gene expression. In the present study, we explored the roles of Jmjd3 in regulating osteoblast apoptosis. Knockdown of Jmjd3 promoted osteoblast apoptosis induced by serum deprivation with decreased mitochondrial membrane potential and increased levels of caspase-3 activation, PARP cleavage, and DNA fragmentation. B cell lymphoma-2 (Bcl-2), an anti-apoptotic protein, was down-regulated by knockdown of Jmjd3 through retaining H3K27me3 on its promoter region. Knockdown of Jmjd3 increased the pro-apoptotic activity of Bim through inhibiting ERK-dependent phosphorylation of Bim. Protein kinase D1 (PKD1), which stimulates ERK phosphorylation, decreased in the Jmjd3-knockdown cells and introduction of PKD1 relieved osteoblast apoptosis in the Jmjd3-knockdown cells through increasing ERK-regulated Bim phosphorylation. These results suggest that Jmjd3 regulates osteoblast apoptosis through targeting Bcl-2 expression and Bim phosphorylation.

  14. In vivo DNA damaging and apoptotic potential of silver nanoparticles in Swiss albino mice

    OpenAIRE

    Al Gurabi MA; Ali D; Alkahtani S; Alarifi S

    2015-01-01

    Mohammed A Al Gurabi, Daoud Ali, Saad Alkahtani, Saud Alarifi Department of Zoology, College of Science, King Saud University, Riyadh, Saudi Arabia Abstract: Nanoparticles can potentially cause adverse effects on organs, tissue, cell levels, and protein levels because of their physicochemical properties. Silver nanoparticles (AgNPs) are being used on a wide scale in world consumer markets; their potential hazards for humans remain largely unknown. This study aimed to investigate the int...

  15. Radiation damage

    CERN Document Server

    Heijne, Erik H M; CERN. Geneva

    1998-01-01

    a) Radiation damage in organic materials. This series of lectures will give an overview of radiation effects on materials and components frequently used in accelerator engineering and experiments. Basic degradation phenomena will be presented for organic materials with comprehensive damage threshold doses for commonly used rubbers, thermoplastics, thermosets and composite materials. Some indications will be given for glass, scintillators and optical fibres. b) Radiation effects in semiconductor materials and devices. The major part of the time will be devoted to treat radiation effects in semiconductor sensors and the associated electronics, in particular displacement damage, interface and single event phenomena. Evaluation methods and practical aspects will be shown. Strategies will be developed for the survival of the materials under the expected environmental conditions of the LHC machine and detectors. I will describe profound revolution in our understanding of black holes and their relation to quantum me...

  16. Histopathological and apoptotic changes on marine mussels Mytilus galloprovincialis (Lamark, 1819) following exposure to environmental pollutants.

    Science.gov (United States)

    Yavaşoğlu, Altuğ; Özkan, Dilara; Güner, Adem; Katalay, Selma; Oltulu, Fatih; Yavaşoğlu, N Ülkü Karabay

    2016-08-15

    Marine bivalve mussels, especially Mytilus species are an earlywarning system used for determining of damage caused by the various aquatic pollutions. In the present study, Mytilus galloprovincialis L. (black mussel) have been utilised as a biomonitoring organism to reveal environmental pollution in the Aliaga, Foca and Urla where located along the Izmir Coast of Turkey. Mussels were collected at these areas and gill and hepatopancreas (digestive gland) tissues were excised. mRNA expressions of initiator (caspase-2 and -8) and executioner (caspase -3/7-1, -3/7-2, -3/7-3 and -3/7-4) caspases of mussels tissues in areas exposed to pollution agent have been observed. TUNEL immunoreactivity in paralel to histopathological changes in both Aliaga and Foca areas were compared with Urla. This study is the first report to reveal the pollution with apoptotic expression on mussels in the coast of Turkey.

  17. Apoptotic resistance to ionizing radiation in pediatric B-precursor acute lymphoblastic leukemia frequently involves increased NF-kappaB survival pathway signaling.

    Science.gov (United States)

    Weston, Victoria J; Austen, Belinda; Wei, Wenbin; Marston, Eliot; Alvi, Azra; Lawson, Sarah; Darbyshire, Philip J; Griffiths, Mike; Hill, Frank; Mann, Jill R; Moss, Paul A H; Taylor, A Malcolm R; Stankovic, Tatjana

    2004-09-01

    To investigate possible causes of the variable response to treatment in pediatric B-precursor acute lymphoblastic leukemia (ALL) and to establish potential novel therapeutic targets, we used ionizing radiation (IR) exposure as a model of DNA damage formation to identify tumors with resistance to p53-dependent apoptosis. Twenty-one of 40 ALL tumors responded normally to IR, exhibiting accumulation of p53 and p21 proteins and cleavage of caspases 3, 7, and 9 and of PARP1. Nineteen tumors exhibited apoptotic resistance and lacked PARP1 and caspase cleavage; although 15 of these tumors had normal accumulation of p53 and p21 proteins, examples exhibited abnormal expression of TRAF5, TRAF6, and cIAP1 after IR, suggesting increased NF-kappaB prosurvival signaling as the mechanism of apoptotic resistance. The presence of a hyperactive PARP1 mutation in one tumor was consistent with such increased NF-kappaB activity. PARP1 inhibition restored p53-dependent apoptosis after IR in these leukemias by reducing NF-kappaB DNA binding and transcriptional activity. In the remaining 4 ALL tumors, apoptotic resistance was associated with a TP53 mutation or with defective activation of p53. We conclude that increased NF-kappaB prosurvival signaling is a frequent mechanism by which B-precursor ALL tumors develop apoptotic resistance to IR and that PARP1 inhibition may improve the DNA damage response of these leukemias.

  18. Role of complement receptor 1 (CR1; CD35) on epithelial cells: A model for understanding complement-mediated damage in the kidney.

    Science.gov (United States)

    Java, Anuja; Liszewski, M Kathryn; Hourcade, Dennis E; Zhang, Fan; Atkinson, John P

    2015-10-01

    The regulators of complement activation gene cluster encodes a group of proteins that have evolved to control the amplification of complement at the critical step of C3 activation. Complement receptor 1 (CR1) is the most versatile of these inhibitors with both receptor and regulatory functions. While expressed on most peripheral blood cells, the only epithelial site of expression in the kidney is by the podocyte. Its expression by this cell population has aroused considerable speculation as to its biologic function in view of many complement-mediated renal diseases. The goal of this investigation was to assess the role of CR1 on epithelial cells. To this end, we utilized a Chinese hamster ovary cell model system. Among our findings, CR1 reduced C3b deposition by ∼ 80% during classical pathway activation; however, it was an even more potent regulator (>95% reduction in C3b deposition) of the alternative pathway. This inhibition was primarily mediated by decay accelerating activity. The deposited C4b and C3b were progressively cleaved with a t½ of ∼ 30 min to C4d and C3d, respectively, by CR1-dependent cofactor activity. CR1 functioned intrinsically (i.e, worked only on the cell on which it was expressed). Moreover, CR1 efficiently and stably bound but didn't internalize C4b/C3b opsonized immune complexes. Our studies underscore the potential importance of CR1 on an epithelial cell population as both an intrinsic complement regulator and an immune adherence receptor. These results provide a framework for understanding how loss of CR1 expression on podocytes may contribute to complement-mediated damage in the kidney.

  19. The apoptotic effect and the plausible mechanism of microwave radiation on rat myocardial cells.

    Science.gov (United States)

    Zhu, Wenhe; Cui, Yan; Feng, Xianmin; Li, Yan; Zhang, Wei; Xu, Junjie; Wang, Huiyan; Lv, Shijie

    2016-08-01

    Microwaves may exert adverse biological effects on the cardiovascular system at the integrated system and cellular levels. However, the mechanism underlying such effects remains poorly understood. Here, we report a previously uncharacterized mechanism through which microwaves damage myocardial cells. Rats were treated with 2450 MHz microwave radiation at 50, 100, 150, or 200 mW/cm(2) for 6 min. Microwave treatment significantly enhanced the levels of various enzymes in serum. In addition, it increased the malondialdehyde content while decreasing the levels of antioxidative stress enzymes, activities of enzyme complexes I-IV, and ATP in myocardial tissues. Notably, irradiated myocardial cells exhibited structural damage and underwent apoptosis. Furthermore, Western blot analysis revealed significant changes in expression levels of proteins involved in oxidative stress regulation and apoptotic signaling pathways, indicating that microwave irradiation could induce myocardial cell apoptosis by interfering with oxidative stress and cardiac energy metabolism. Our findings provide useful insights into the mechanism of microwave-induced damage to the cardiovascular system.

  20. New Insights into p53 Signaling and Cancer Cell Response to DNA Damage: Implications for Cancer Therapy

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    Razmik Mirzayans

    2012-01-01

    Full Text Available Activation of the p53 signaling pathway by DNA-damaging agents was originally proposed to result either in cell cycle checkpoint activation to promote survival or in apoptotic cell death. This model provided the impetus for numerous studies focusing on the development of p53-based cancer therapies. According to recent evidence, however, most p53 wild-type human cell types respond to ionizing radiation by undergoing stress-induced premature senescence (SIPS and not apoptosis. SIPS is a sustained growth-arrested state in which cells remain viable and secrete factors that may promote cancer growth and progression. The p21WAF1 (hereafter p21 protein has emerged as a key player in the p53 pathway. In addition to its well-studied role in cell cycle checkpoints, p21 regulates p53 and its upstream kinase (ATM, controls gene expression, suppresses apoptosis, and induces SIPS. Herein, we review these and related findings with human solid tumor-derived cell lines, report new data demonstrating dynamic behaviors of p53 and p21 in the DNA damage response, and examine the gain-of-function properties of cancer-associated p53 mutations. We point out obstacles in cancer-therapeutic strategies that are aimed at reactivating the wild-type p53 function and highlight some alternative approaches that target the apoptotic threshold in cancer cells with differing p53 status.

  1. Apoptotic Cell Death Induced by Resveratrol Is Partially Mediated by the Autophagy Pathway in Human Ovarian Cancer Cells.

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    Fangfang Lang

    Full Text Available Resveratrol (trans-3,4,5'-trihydroxystilbene is an active compound in food, such as red grapes, peanuts, and berries. Resveratrol exhibits an anticancer effect on various human cancer cells. However, the mechanism of resveratrol-induced anti-cancer effect at the molecular level remains to be elucidated. In this study, the mechanism underlying the anti-cancer effect of resveratrol in human ovarian cancer cells (OVCAR-3 and Caov-3 was investigated using various molecular biology techniques, such as flow cytometry, western blotting, and RNA interference, with a major focus on the potential role of autophagy in resveratrol-induced apoptotic cell death. We demonstrated that resveratrol induced reactive oxygen species (ROS generation, which triggers autophagy and subsequent apoptotic cell death. Resveratrol induced ATG5 expression and promoted LC3 cleavage. The apoptotic cell death induced by resveratrol was attenuated by both pharmacological and genetic inhibition of autophagy. The autophagy inhibitor chloroquine, which functions at the late stage of autophagy, significantly reduced resveratrol-induced cell death and caspase 3 activity in human ovarian cancer cells. We also demonstrated that targeting ATG5 by siRNA also suppressed resveratrol-induced apoptotic cell death. Thus, we concluded that a common pathway between autophagy and apoptosis exists in resveratrol-induced cell death in OVCAR-3 human ovarian cancer cells.

  2. Macrophage peroxisome proliferator-activated receptor γ deficiency delays skin wound healing through impairing apoptotic cell clearance in mice.

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    Chen, H; Shi, R; Luo, B; Yang, X; Qiu, L; Xiong, J; Jiang, M; Liu, Y; Zhang, Z; Wu, Y

    2015-01-15

    Skin wound macrophages are key regulators of skin repair and their dysfunction causes chronic, non-healing skin wounds. Peroxisome proliferator-activated receptor gamma (PPARγ) regulates pleiotropic functions of macrophages, but its contribution in skin wound healing is poorly defined. We observed that macrophage PPARγ expression was upregulated during skin wound healing. Furthermore, macrophage PPARγ deficiency (PPARγ-knock out (KO)) mice exhibited impaired skin wound healing with reduced collagen deposition, angiogenesis and granulation formation. The tumor necrosis factor alpha (TNF-α) expression in wounds of PPARγ-KO mice was significantly increased and local restoration of TNF-α reversed the healing deficit in PPARγ-KO mice. Wound macrophages produced higher levels of TNF-α in PPARγ-KO mice compared with control. In vitro, the higher production of TNF-α by PPARγ-KO macrophages was associated with impaired apoptotic cell clearance. Correspondingly, increased apoptotic cell accumulation was found in skin wound of PPARγ-KO mice. Mechanically, peritoneal and skin wound macrophages expressed lower levels of various phagocytosis-related molecules. In addition, PPARγ agonist accelerated wound healing and reduced local TNF-α expression and wound apoptotic cells accumulation in wild type but not PPARγ-KO mice. Therefore, PPARγ has a pivotal role in controlling wound macrophage clearance of apoptotic cells to ensure efficient skin wound healing, suggesting a potential new therapeutic target for skin wound healing.

  3. Regulation of cell death receptor S-nitrosylation and apoptotic signaling by Sorafenib in hepatoblastoma cells.

    Science.gov (United States)

    Rodríguez-Hernández, A; Navarro-Villarán, E; González, R; Pereira, S; Soriano-De Castro, L B; Sarrias-Giménez, A; Barrera-Pulido, L; Álamo-Martínez, J M; Serrablo-Requejo, A; Blanco-Fernández, G; Nogales-Muñoz, A; Gila-Bohórquez, A; Pacheco, D; Torres-Nieto, M A; Serrano-Díaz-Canedo, J; Suárez-Artacho, G; Bernal-Bellido, C; Marín-Gómez, L M; Barcena, J A; Gómez-Bravo, M A; Padilla, C A; Padillo, F J; Muntané, J

    2015-12-01

    Nitric oxide (NO) plays a relevant role during cell death regulation in tumor cells. The overexpression of nitric oxide synthase type III (NOS-3) induces oxidative and nitrosative stress, p53 and cell death receptor expression and apoptosis in hepatoblastoma cells. S-nitrosylation of cell death receptor modulates apoptosis. Sorafenib is the unique recommended molecular-targeted drug for the treatment of patients with advanced hepatocellular carcinoma. The present study was addressed to elucidate the potential role of NO during Sorafenib-induced cell death in HepG2 cells. We determined the intra- and extracellular NO concentration, cell death receptor expression and their S-nitrosylation modifications, and apoptotic signaling in Sorafenib-treated HepG2 cells. The effect of NO donors on above parameters has also been determined. Sorafenib induced apoptosis in HepG2 cells. However, low concentration of the drug (10nM) increased cell death receptor expression, as well as caspase-8 and -9 activation, but without activation of downstream apoptotic markers. In contrast, Sorafenib (10 µM) reduced upstream apoptotic parameters but increased caspase-3 activation and DNA fragmentation in HepG2 cells. The shift of cell death signaling pathway was associated with a reduction of S-nitrosylation of cell death receptors in Sorafenib-treated cells. The administration of NO donors increased S-nitrosylation of cell death receptors and overall induction of cell death markers in control and Sorafenib-treated cells. In conclusion, Sorafenib induced alteration of cell death receptor S-nitrosylation status which may have a relevant repercussion on cell death signaling in hepatoblastoma cells.

  4. Cell Volume Regulation and Apoptotic Volume Decrease in Rat Distal Colon Superficial Enterocytes

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    Stefania Antico

    2013-12-01

    Full Text Available Background: The colon epithelium is physiologically exposed to osmotic stress, and the activation of cell volume regulation mechanisms is essential in colonocyte physiology. Moreover, colon is characterized by a high apoptotic rate of mature cells balancing the high division rate of stem cells. Aim: The aim of the present work was to investigate the main cell volume regulation mechanisms in rat colon surface colonocytes and their role in apoptosis. Methods: Cell volume changes were measured by light microscopy and video imaging on colon explants; apoptosis sign appearance was monitored by confocal microscopy on annexin V/propidium iodide labeled explants. Results: Superficial colonocytes showed a dynamic regulation of their cell volume during anisosmotic conditions with a Regulatory Volume Increase (RVI response following hypertonic shrinkage and Regulatory Volume Decrease (RVD response following hypotonic swelling. RVI was completely inhibited by bumetanide, while RVD was completely abolished by high K+ or iberiotoxin treatment and by extracellular Ca2+ removal. DIDS incubation was also able to affect the RVD response. When colon explants were exposed to H2O2 as apoptotic inducer, colonocytes underwent an isotonic volume decrease ascribable to Apoptotic Volume Decrease (AVD within about four hours of exposure. AVD was shown to precede annexin V positivity. It was also inhibited by high K+ or iberiotoxin treatment. Interestingly, treatment with iberiotoxin significantly inhibited apoptosis progression. Conclusions: In rat superficial colonocytes K+ efflux through high conductance Ca2+-activated K+ channels (BK channels was demonstrated to be the main mechanism of RVD and to plays also a crucial role in the AVD process and in the progression of apoptosis.

  5. Nitroglycerin induces DNA damage and vascular cell death in the setting of nitrate tolerance.

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    Mikhed, Yuliya; Fahrer, Jörg; Oelze, Matthias; Kröller-Schön, Swenja; Steven, Sebastian; Welschof, Philipp; Zinßius, Elena; Stamm, Paul; Kashani, Fatemeh; Roohani, Siyer; Kress, Joana Melanie; Ullmann, Elisabeth; Tran, Lan P; Schulz, Eberhard; Epe, Bernd; Kaina, Bernd; Münzel, Thomas; Daiber, Andreas

    2016-07-01

    Nitroglycerin (GTN) and other organic nitrates are widely used vasodilators. Their side effects are development of nitrate tolerance and endothelial dysfunction. Given the potential of GTN to induce nitro-oxidative stress, we investigated the interaction between nitro-oxidative DNA damage and vascular dysfunction in experimental nitrate tolerance. Cultured endothelial hybridoma cells (EA.hy 926) and Wistar rats were treated with GTN (ex vivo: 10-1000 µM; in vivo: 10, 20 and 50 mg/kg/day for 3 days, s.c.). The level of DNA strand breaks, 8-oxoguanine and O (6)-methylguanine DNA adducts was determined by Comet assay, dot blot and immunohistochemistry. Vascular function was determined by isometric tension recording. DNA adducts and strand breaks were induced by GTN in cells in vitro in a concentration-dependent manner. GTN in vivo administration leads to endothelial dysfunction, nitrate tolerance, aortic and cardiac oxidative stress, formation of DNA adducts, stabilization of p53 and apoptotic death of vascular cells in a dose-dependent fashion. Mice lacking O (6)-methylguanine-DNA methyltransferase displayed more vascular O (6)-methylguanine adducts and oxidative stress under GTN therapy than wild-type mice. Although we were not able to prove a causal role of DNA damage in the etiology of nitrate tolerance, the finding of GTN-induced DNA damage such as the mutagenic and toxic adduct O (6)-methylguanine, and cell death supports the notion that GTN based therapy may provoke adverse side effects, including endothelial function. Further studies are warranted to clarify whether GTN pro-apoptotic effects are related to an impaired recovery of patients upon myocardial infarction.

  6. Regulation of Apoptotic Endonucleases by EndoG

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    Zhdanov, Dmitry D.; Fahmi, Tariq; Wang, Xiaoying; Apostolov, Eugene O.; Sokolov, Nikolai N.; Javadov, Sabzali

    2015-01-01

    Cells contain several apoptotic endonucleases, which appear to act simultaneously before and after cell death by destroying the host cell DNA. It is largely unknown how the endonucleases are being induced and whether they can regulate each other. This study was performed to determine whether apoptotic mitochondrial endonuclease G (EndoG) can regulate expression of other apoptotic endonucleases. The study showed that overexpression of mature EndoG in kidney tubular epithelial NRK-52E cells can increase expression of caspase-activated DNase (CAD) and four endonucleases that belong to DNase I group including DNase I, DNase X, DNase IL2, and DNase γ, but not endonucleases of the DNase 2 group. The induction of DNase I-type endonucleases was associated with DNA degradation in promoter/exon 1 regions of the endonuclease genes. These results together with findings on colocalization of immunostained endonucleases and TUNEL suggest that DNA fragmentation after EndoG overexpression was caused by DNase I endonucleases and CAD in addition to EndoG itself. Overall, these data provide first evidence for the existence of the integral network of apoptotic endonucleases regulated by EndoG. PMID:25849439

  7. Climate change: Unattributed hurricane damage

    Science.gov (United States)

    Hallegatte, Stéphane

    2015-11-01

    In the United States, hurricanes have been causing more and more economic damage. A reanalysis of the disaster database using a statistical method that accounts for improvements in resilience opens the possibility that climate change has played a role.

  8. H2 damage of ferroelectric Pb(Zr,Ti)O3 thin-film capacitors—The role of catalytic and adsorptive activity of the top electrode

    Science.gov (United States)

    Shimamoto, Y.; Kushida-Abdelghafar, K.; Miki, H.; Fujisaki, Y.

    1997-06-01

    Large-scale integrated fabrication in a H2 containing atmosphere, for example, during the passivation process, can cause serious damage in metal/Pb(Zr,Ti)O3/metal capacitors (i.e., Pt/PZT/Pt capacitors). To reveal the cause of the H2 damage, we investigated the behavior of hysteresis curves and the leakage current of capacitors with a top electrode of Pt, Pd, Au, or Ag. Capacitors with a top electrode of Au or Ag are more resistant to the H2 annealing damage than those of Pt or Pd. We found that the H2 damage was strongly affected by the catalytic activity and adsorptive properties of the top electrode when exposed to H2.

  9. Role of genetic polymorphisms of CYP1A1, CYP3A5, CYP2C9, CYP2D6, and PON1 in the modulation of DNA damage in workers occupationally exposed to organophosphate pesticides.

    Science.gov (United States)

    Singh, Satyender; Kumar, Vivek; Vashisht, Kapil; Singh, Priyanka; Banerjee, Basu Dev; Rautela, Rajender Singh; Grover, Shyam Sunder; Rawat, Devendra Singh; Pasha, Syed Tazeen; Jain, Sudhir Kumar; Rai, Arvind

    2011-11-15

    Organophosphate pesticides (OPs) are primarily metabolized by several xenobiotic metabolizing enzymes (XMEs). Very few studies have explored genetic polymorphisms of XMEs and their association with DNA damage in pesticide-exposed workers. The present study was designed to determine the role of genetic polymorphisms of CYP1A1, CYP3A5, CYP2C9, CYP2D6, and PON1 in the modulation of DNA damage in workers occupationally exposed to OPs. We examined 284 subjects including 150 workers occupationally exposed to OPs and 134 normal healthy controls. The DNA damage was evaluated using the alkaline comet assay and genotyping was done using PCR-RFLP. The results revealed that the PONase activity toward paraoxonase and AChE activity was found significantly lowered in workers as compared to control subjects (p<0.001). Workers showed significantly higher DNA damage compared to control subjects (14.37±2.15 vs. 6.24±1.37 tail% DNA, p<0.001). Further, the workers with CYP2D6*3PM and PON1 (QQ and MM) genotypes were found to have significantly higher DNA damage when compared to other genotypes (p<0.05). In addition, significant increase in DNA damage was also observed in workers with concomitant presence of certain CYP2D6 and PON1 (Q192R and L55M) genotypes which need further extensive studies. In conclusion, the results indicate that the PON1 and CYP2D6 genotypes can modulate DNA damage elicited by some OPs possibly through gene-environment interactions.

  10. Climacostol reduces tumour progression in a mouse model of melanoma via the p53-dependent intrinsic apoptotic programme

    Science.gov (United States)

    Perrotta, Cristiana; Buonanno, Federico; Zecchini, Silvia; Giavazzi, Alessio; Proietti Serafini, Francesca; Catalani, Elisabetta; Guerra, Laura; Belardinelli, Maria Cristina; Picchietti, Simona; Fausto, Anna Maria; Giorgi, Simone; Marcantoni, Enrico; Clementi, Emilio; Ortenzi, Claudio; Cervia, Davide

    2016-01-01

    Climacostol, a compound produced by the ciliated protozoan Climacostomum virens, displayed cytotoxic properties in vitro. This study demonstrates that it has anti-tumour potential. Climacostol caused a reduction of viability/proliferation of B16-F10 mouse melanoma cells, a rapidly occurring DNA damage, and induced the intrinsic apoptotic pathway characterised by the dissipation of the mitochondrial membrane potential, the translocation of Bax to the mitochondria, the release of Cytochrome c from the mitochondria, and the activation of Caspase 9-dependent cleavage of Caspase 3. The apoptotic mechanism of climacostol was found to rely on the up-regulation of p53 and its targets Noxa and Puma. In vivo analysis of B16-F10 allografts revealed a persistent inhibition of tumour growth rate when melanomas were treated with intra-tumoural injections of climacostol. In addition, it significantly improved the survival of transplanted mice, decreased tumour weight, induced a remarkable reduction of viable cells inside the tumour, activated apoptosis and up-regulated the p53 signalling network. Importantly, climacostol toxicity was more selective against tumour than non-tumour cells. The anti-tumour properties of climacostol and the molecular events associated with its action indicate that it is a powerful agent that may be considered for the design of pro-apoptotic drugs for melanoma therapy. PMID:27271364

  11. Evaluation of anti-apoptotic activity of different dietary antioxidants in renal cell carcinoma against hydrogen peroxide

    Institute of Scientific and Technical Information of China (English)

    Garg; Neeraj; K; Mangal; Sharad; Sahu; Tejram; Mehta; Abhinav; Vyas; Suresh; P; Tyagi; Rajeev; K

    2011-01-01

    Objective:To evaluate the anti-apoptotic and radical scavenging activities of dietary phenolics, namely ascorbic acid,a-tocopherol acetate,citric acid,salicylic acid,and estimate H2O2induced apoptosis in renal cell carcinoma cells.Methods:The intracellular antioxidant potency of antioxidants was investigated.H2O-2-induced apoptosis in RCC-26 was assayed with the following parameters:cell viability(%apoptosis),nucleosomal damage and DNA fragmentation, bcl-2 levels and flow cytometery analysis(ROS production evaluation).Results:Ine anticancer properties of antioxidants such as ascorbic acid,a- tocopherol acetate,citric acid,salicylic acid with perdurable responses were investigated.It was observed that these antioxidants had protective effect(anti-apoptotic activity) against hydrogen peroxide(H2O2) in renal cell carcinoma(RCC-26) cell line.Conclusions:This study reveals and proves the anticancer properties.However,in cancer cell lines anti-apoptotic activity can indirectly reflect the cancer promoter activity through radicals scavenging,and significantly protect nucleus and bcl-2.

  12. Interaction between caspase-8 activation and endoplasmic reticulum stress in glycochenodeoxycholic acid-induced apoptotic HepG2 cells.

    Science.gov (United States)

    Iizaka, Toru; Tsuji, Mayumi; Oyamada, Hideto; Morio, Yuri; Oguchi, Katsuji

    2007-11-30

    The accumulation of hydrophobic bile acid, such as glycochenodeoxycholic acid (GCDCA), in the liver has been thought to induce hepatocellular damage in human chronic cholestatic liver diseases. We previously reported that GCDCA-induced apoptosis was promoted by both mitochondria-mediated and endoplasmic reticulum (ER) stress-associated pathways in rat hepatocytes. In this study, we elucidated the relationship between these pathways in GCDCA-induced apoptotic HepG2 cells. HepG2 cells were treated with GCDCA (100-500microM) with or without a caspase-8 inhibitor, Z-IETD-fluoromethyl ketone (Z-IETD-FMK) (30microM) for 3-24h. We demonstrated the presence of both apoptotic pathways in these cells; that is, we showed increases in cleaved caspase-3 proteins, the release of cytochrome c from mitochondria, and the expression of ER resident molecular chaperone Bip mRNA and ER stress response-associated transcription factor Chop mRNA. On the other hand, pretreatment with Z-IETD-FMK significantly reduced the increases, compared with treatment with GCDCA alone. Immunofluorescence microscopic analysis showed that treatment with GCDCA increased the cleavage of BAP31, an integral membrane protein of ER, and pretreatment with Z-IETD-FMK suppressed the increase of caspase-8 and BAP31 cleavage. In conclusion, these results suggest that intact activated caspase-8 may promote and amplify the ER stress response by cleaving BAP31 in GCDCA-induced apoptotic cells.

  13. Targeting Protective Autophagy Exacerbates UV-Triggered Apoptotic Cell Death

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    Shih-Hwa Chiou

    2012-01-01

    Full Text Available Autophagy is activated by various stresses, including DNA damage, and previous studies of DNA damage-induced autophagy have focused on the response to chemotherapeutic drugs, ionizing radiation, and reactive oxygen species. In this study, we investigated the biological significance of autophagic response to ultraviolet (UV irradiation in A549 and H1299 cells. Our results indicated that UV induces on-rate autophagic flux in these cells. Autophagy inhibition resulting from the knockdown of beclin-1 and Atg5 reduced cell viability and enhanced apoptosis. Moreover, we found that ATR phosphorylation was accompanied by microtubule-associated protein 1 light chain 3B II (LC3B-II expression during the early phases following UV irradiation, which is a well-established inducer of ATR. Knocking down ATR further attenuated the reduction in LC3B-II at early stages in response to UV treatment. Despite the potential role of ATR in autophagic response, reduced ATR expression does not affect autophagy induction during late phases (24 and 48 h after UV treatment. The result is consistent with the reduced ATR phosphorylation at the same time points and suggests that autophagic response at this stage is activated via a distinct pathway. In conclusion, this study demonstrated that autophagy acts as a cytoprotective mechanism against UV-induced apoptosis and that autophagy induction accompanied with apoptosis at late stages is independent of ATR activation.

  14. Potential for Modulation of the Fas Apoptotic Pathway by Epidermal Growth Factor in Sarcomas

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    David E. Joyner

    2011-01-01

    Full Text Available One important mechanism by which cancer cells parasitize their host is by escaping apoptosis. Thus, selectively facilitating apoptosis is a therapeutic mechanism by which oncotherapy may prove highly advantageous. One major apoptotic pathway is mediated by Fas ligand (FasL. The death-inducing signaling Ccmplex (DISC and subsequent death-domain aggregations are created when FasL is bound by its receptor thereby enabling programmed cell death. Conceptually, if a better understanding of the Fas pathway can be garnered, an oncoselective prodeath therapeutic approach can be tailored. Herein, we propose that EGF and CTGF play essential roles in the regulation of the Fas apoptotic pathway in sarcomas. Tumor and in vitro data suggest viable cells counter the prodeath signal induced by FasL by activating EGF, which in turn induces prosurvival CTGF. The prosurvival attributes of CTGF ultimately predominate over the death-inducing FasL. Cells destined for elimination inhibit this prosurvival response via a presently undefined pathway. This scenario represents a novel role for EGF and CTGF as regulators of the Fas pathway in sarcomas.

  15. Generation of Reactive Oxygen Species during Apoptosis Induced by DNA-Damaging Agents and/or Histone Deacetylase Inhibitors

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    Barbora Brodská

    2011-01-01

    Full Text Available Reactive oxygen species play an important role in the process of apoptosis in many cell types. In this paper, we analyzed the role of ROS in DNA-damaging agents (actinomycin D or decitabine, which induced apoptosis of leukemia cell line CML-T1 and normal peripheral blood lymphocytes (PBL. The possibility of synergism with histone deacetylase inhibitors butyrate or SAHA is also reported. We found that in cancer cell line, ROS production significantly contributed to apoptosis triggering, while in normal lymphocytes treated by cytostatic or cytotoxic drugs, necrosis as well as apoptosis occurred and large heterogeneity of ROS production was measured. Combined treatment with histone deacetylase inhibitor did not potentiate actinomycin D action, whereas combination of decitabine and SAHA brought synergistic ROS generation and apoptotic features in CML cell line. Appropriate decrease of cell viability indicated promising therapeutic potential of this combination in CML, but side effects on normal PBL should be taken into attention.

  16. Saponins from Tribulus terrestris L. protect human keratinocytes from UVB-induced damage.

    Science.gov (United States)

    Sisto, Margherita; Lisi, Sabrina; D'Amore, Massimo; De Lucro, Raffaella; Carati, Davide; Castellana, Donatello; La Pesa, Velia; Zuccarello, Vincenzo; Lofrumento, Dario D

    2012-12-05

    Chronic exposure to solar UVB radiation damages skin, increasing the risk to develop cancer. Hence the identification of compounds with a photoprotective efficacy is essential. This study examined the role of saponins derived from Tribulus terrestris L. (TT) on the modulation of apoptosis in normal human keratinocytes (NHEK) exposed to physiological doses of UVB and to evaluate their antitumoral properties. In NHEK, TT saponins attenuate UVB-induced programmed cell death through inhibition of intrinsic apoptotic pathway. In squamous cell carcinomas (SCC) TT saponins do not make the malignant keratinocytes more resistant to UVB and determine an enhanced apoptotic response. The photoprotective effect of TT saponins is tightly correlated to the enhancement of NER genes expression and the block of UVB-mediated NF-κB activation. Collectively, our study shows experimental evidence that TT has a preventive efficacy against UVB-induced carcinogenesis and the molecular knowledge on the mechanisms through which TT saponins regulate cell death suggests great potential for TT to be developed into a new medicine for cancer patients.

  17. The calcium-sensing receptor participates in testicular damage in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Kong, Wei-Yuan; Tong, Li-Quan; Zhang, Hai-Jun; Cao, Yong-Gang; Wang, Gong-Chen; Zhu, Jin-Zhi; Zhang, Feng; Sun, Xue-Ying; Zhang, Tie-Hui; Zhang, Lin-Lin

    2016-01-01

    Male infertility caused by testicular damage is one of the complications of diabetes mellitus. The calcium-sensing receptor (CaSR) is expressed in testicular tissues and plays a pivotal role in calcium homeostasis by activating cellular signaling pathways, but its role in testicular damage induced by diabetes remains unclear. A diabetic model was established by a single intraperitoneal injection of streptozotocin (STZ, 40 mg kg-1 ) in Wistar rats. Animals then received GdCl 3 (an agonist of CaSR, 8.67 mg kg-1 ), NPS-2390 (an antagonist of CaSR, 0.20 g kg-1 ), or a combination of both 2 months after STZ injection. Diabetic rats had significantly lower testes weights and serum levels of testosterone compared to healthy rats, indicating testicular damage and dysfunction in STZ-induced diabetic rats. Compared with healthy controls, the testicular tissues of diabetic rats overexpressed the CaSR protein and had higher levels of malondialdehyde (MDA), lower superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity, and higher numbers of apoptotic germ cells. The testicular tissues from diabetic rats also expressed lower levels of Bcl-2 and higher levels of Bax and cleaved caspase-3 in addition to higher phosphorylation rates of c-Jun NH 2 -terminal protein kinase (JNK), p38, and extracellular signaling-regulated kinase (ERK) 1/2. The above parameters could be further increased or aggravated by the administration of GdCl 3 , but could be attenuated by injection of NPS-2390. In conclusion, the present results indicate that CaSR activation participates in diabetes-induced testicular damage, implying CaSR may be a potential target for protective strategies against diabetes-induced testicular damage and could help to prevent infertility in diabetic men.

  18. The calcium-sensing receptor participates in testicular damage in streptozotocin-induced diabetic rats

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    Wei-Yuan Kong

    2016-01-01

    Full Text Available Male infertility caused by testicular damage is one of the complications of diabetes mellitus. The calcium-sensing receptor (CaSR is expressed in testicular tissues and plays a pivotal role in calcium homeostasis by activating cellular signaling pathways, but its role in testicular damage induced by diabetes remains unclear. A diabetic model was established by a single intraperitoneal injection of streptozotocin (STZ, 40 mg kg−1 in Wistar rats. Animals then received GdCl 3 (an agonist of CaSR, 8.67 mg kg−1 , NPS-2390 (an antagonist of CaSR, 0.20 g kg−1 , or a combination of both 2 months after STZ injection. Diabetic rats had significantly lower testes weights and serum levels of testosterone compared to healthy rats, indicating testicular damage and dysfunction in STZ-induced diabetic rats. Compared with healthy controls, the testicular tissues of diabetic rats overexpressed the CaSR protein and had higher levels of malondialdehyde (MDA, lower superoxide dismutase (SOD and glutathione peroxidase (GSH-Px activity, and higher numbers of apoptotic germ cells. The testicular tissues from diabetic rats also expressed lower levels of Bcl-2 and higher levels of Bax and cleaved caspase-3 in addition to higher phosphorylation rates of c-Jun NH 2 -terminal protein kinase (JNK, p38, and extracellular signaling-regulated kinase (ERK 1/2. The above parameters could be further increased or aggravated by the administration of GdCl 3 , but could be attenuated by injection of NPS-2390. In conclusion, the present results indicate that CaSR activation participates in diabetes-induced testicular damage, implying CaSR may be a potential target for protective strategies against diabetes-induced testicular damage and could help to prevent infertility in diabetic men.

  19. Mechanisms involved in protection afforded by L-arginine in ibuprofen-induced gastric damage: role of nitric oxide and prostaglandins.

    Science.gov (United States)

    Jiménez, Dolores; Martin, M José; Pozo, David; Alarcón, Catalina; Esteban, José; Bruseghini, Leo; Esteras, Antonio; Motilva, Virginia

    2002-01-01

    L-Arginine (L-arg) exhibits multiple biological properties and plays an important role in the regulation of different functions in pathological conditions. Many of these effects could be achieved on this amino acid serving as a substrate for the enzyme nitric oxide synthase (NOS). At the gastrointestinal level, recent reports revealed its protective activities involving a hyperemic response increasing the gastric blood flow. The aim of this study was to characterize the relationship between NOS activity/expression and prostaglandin changes (PGs) in rats gastric mucosa, with L-arg associated resistance to the nonsteroidal anti-inflammatory drug (NSAID) ibuprofen (IBP). The protective effect of oral L-arg (100 mg/kg body wt), administerred together with IBP (100 mg/kg body wt, per os), was evident enough 90 min after drug administration, although a significant protection persisted for more than 6 hr. Pretreatment with N(G)-nitro-L-arginine (L-NNA) (40 mg/kg body wt, intraperitoneally), a competitive inhibitor of constitutive NOS, partly altered the protection afforded by the amino acid. In contrast, no changes could be observed after inducible NOS inhibition [aminoguanidine (AG) 50 mg/Kg body wt, intraperitoneally). L-arg, plus IBP, produced a significant increase of the cyclic GMP (cGMP) response in tissue samples from rat stomach, 90 min and 6 h after drug administration. iNOS activity and mRNA expression were higher in IBP-treated rats, and no differences were observed in inducible responses in the L-arg plus IBP group. No variations in the cNOS activity and expression were found among the different groups of animals assayed. The measurement of mucosal PGE2 content confirmed that biosynthesis of the eicosanoid is maintained by L-arg for over 90 min after IBP, while a total inhibition was observed 6 hr later. The mechanisms of the L-arg protective effect on the damaged induced by IBP could be explained by the different period after drug administration. The early

  20. Apoptotic cell death and its relationship to gastric carcinogenesis

    Institute of Scientific and Technical Information of China (English)

    Ferda Bir; Nese Calli-Demirkan; A Cevik Tufan; Metin Akbulut; N Lale Satiroglu-Tufan

    2007-01-01

    AIM: To investigate the apoptotic process of cells within the intestinal metaplasia areas co-localizing with chronic gastritis and gastric carcinomas and to analyze the involvement of proteins regulating apoptosis in the process of intestinal metaplasia related gastric carcinogenesis.METHODS: Forty-two gastric carcinoma and seventeen chronic gastritis cases were included in this study. All cases were examined for the existence of intestinal metaplasia. Ten cases randomly selected from each group were processed for TUNEL assay. TUNEL positive cells within the intestinal metaplasia areas, colocalizing either to gastric carcinoma or chronic gastritis,were counted and converted to apoptotic indices.In addition, p53, bcl-2 and bax expression patterns within these tissues were analyzed on the basis of immunohistochemistry.RESULTS: Twenty-eight of the cases were intestinal and 14 of the cases were diffuse type adenocarcinomas.64% (27/42) of the gastric carcinoma cases had intestinal metaplasia. Intestinal metaplasia co-localized more with intestinal type carcinomas compared with diffuse type carcinomas [75% (21/28) vs 42% (6/14),respectively; P≤0.05]. The mean apoptotic index in tumor cells was 0.70±0.08. The mean apoptotic index in intestinal metaplasias co-localizing to tumors was significantly higher than that of intestinal metaplasias co-localizing to chronic gastritis (0.70±0.03 vs 0.09±0.01, respectively; P≤0.05). P53 positivity was not observed in areas of intestinal metaplasia adjacent to tumors or chronic gastritis. Intestinal metaplasia areas adjacent to tumors showed lower cytoplasmic bcl-2 positivity compared to intestinal metaplasia areas adjacent to chronic gastritis [55.5% (15/27) vs 70.5%(12/17), respectively]. On the other hand, intestinal metaplasia areas adjacent to tumors showed significantly higher cytoplasmic bax positivity compared to intestinal metaplasia areas adjacent to chronic gastritis [44.4%(12/27) vs 11.7% (2/17), respectively; P≤0

  1. WNT signaling controls expression of pro-apoptotic BOK and BAX in intestinal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Zeilstra, Jurrit; Joosten, Sander P.J. [Department of Pathology, Academic Medical Center, University of Amsterdam (Netherlands); Wensveen, Felix M. [Department of Experimental Immunology, Academic Medical Center, Amsterdam (Netherlands); Dessing, Mark C.; Schuetze, Denise M. [Department of Pathology, Academic Medical Center, University of Amsterdam (Netherlands); Eldering, Eric [Department of Experimental Immunology, Academic Medical Center, Amsterdam (Netherlands); Spaargaren, Marcel [Department of Pathology, Academic Medical Center, University of Amsterdam (Netherlands); Pals, Steven T., E-mail: s.t.pals@amc.uva.nl [Department of Pathology, Academic Medical Center, University of Amsterdam (Netherlands)

    2011-03-04

    Research highlights: {yields} Intestinal adenomas initiated by aberrant activation of the WNT pathway displayed an increased sensitivity to apoptosis. {yields} Expression profiling of apoptosis-related genes in Apc{sup Min/+} mice revealed the differential expression of pro-apoptotic Bok and Bax. {yields} APC-mutant adenomatous crypts in FAP patients showed strongly increased BAX immunoreactivity. {yields} Blocking of {beta}-catenin/TCF-4-mediated signaling in colon cancer cells reduced the expression of BOK and BAX. -- Abstract: In a majority of cases, colorectal cancer is initiated by aberrant activation of the WNT signaling pathway. Mutation of the genes encoding the WNT signaling components adenomatous polyposis coli or {beta}-catenin causes constitutively active {beta}-catenin/TCF-mediated transcription, driving the transformation of intestinal crypts to cancer precursor lesions, called dysplastic aberrant crypt foci. Deregulated apoptosis is a hallmark of adenomatous colon tissue. However, the contribution of WNT signaling to this process is not fully understood. We addressed this role by analyzing the rate of epithelial apoptosis in aberrant crypts and adenomas of the Apc{sup Min/+} mouse model. In comparison with normal crypts and adenomas, aberrant crypts displayed a dramatically increased rate of apoptotic cell death. Expression profiling of apoptosis-related genes along the crypt-villus axis and in Apc mutant adenomas revealed increased expression of two pro-apoptotic Bcl-2 family members in intestinal adenomas, Bok and Bax. Analysis of the colon of familial adenomatous polyposis (FAP) patients along the crypt-to-surface axis, and of dysplastic crypts, corroborated this expression pattern. Disruption of {beta}-catenin/TCF-4-mediated signaling in the colorectal cancer cell line Ls174T significantly decreased BOK and BAX expression, confirming WNT-dependent regulation in intestinal epithelial cells. Our results suggest a feedback mechanism by which

  2. HSP70 mediates survival in apoptotic cells-Boolean network prediction and experimental validation.

    Science.gov (United States)

    Vasaikar, Suhas V; Ghosh, Sourish; Narain, Priyam; Basu, Anirban; Gomes, James

    2015-01-01

    Neuronal stress or injury results in the activation of proteins, which regulate the balance between survival and apoptosis. However, the complex mechanism of cell signaling involving cell death and survival, activated in response to cellular stress is not yet completely understood. To bring more clarity about these mechanisms, a Boolean network was constructed that represented the apoptotic pathway in neuronal cells. FasL and neurotrophic growth factor (NGF) were considered as inputs in the absence and presence of heat shock proteins known to shift the balance toward survival by rescuing pro-apoptotic cells. The probabilities of survival, DNA repair and apoptosis as cellular fates, in the presence of either the growth factor or FasL, revealed a survival bias encoded in the network. Boolean predictions tested by measuring the mRNA level of caspase-3, caspase-8, and BAX in neuronal Neuro2a (N2a) cell line with NGF and FasL as external input, showed positive correlation with the observed experimental results for survival and apoptotic states. It was observed that HSP70 contributed more toward rescuing cells from apoptosis in comparison to HSP27, HSP40, and HSP90. Overexpression of HSP70 in N2a transfected cells showed reversal of cellular fate from FasL-induced apoptosis to survival. Further, the pro-survival role of the proteins BCL2, IAP, cFLIP, and NFκB determined by vertex perturbation analysis was experimentally validated through protein inhibition experiments using EM20-25, Embelin and Wedelolactone, which resulted in 1.27-, 1.26-, and 1.46-fold increase in apoptosis of N2a cells. The existence of a one-to-one correspondence between cellular fates and attractor states shows that Boolean networks may be employed with confidence in qualitative analytical studies of biological networks.

  3. Involvement of advanced lipooxidation end products (ALEs) and protein oxidation in the apoptotic actions of nitric oxide in insulin secreting RINm5F cells.

    Science.gov (United States)

    Cahuana, Gladys M; Tejedo, Juan R; Jiménez, Juan; Ramírez, Remedios; Sobrino, Francisco; Bedoya, Francisco J

    2003-11-15

    We have explored the impact of nitric oxide (NO) exposure on oxidation damage of lipids, and proteins, and the contribution of this type of damage to the activation of the apoptotic program in insulin secreting RINm5F cells. Exposure of cells to NO donors and to interleukin-1 beta (IL-1beta) led to generation of lipooxidation products such as malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE). Addition of superoxide dismutase (SOD) and catalase (Cat) to cells decreased by 50% MDA and 4-HNE production induced by IL-1beta. Over-expression of Mn-SOD in cells conferred a remarkable decrease (75%) in IL-1beta-induced lipid peroxidation. These data suggest that peroxynitrite (ONOO(-)) mediates peroxidative damage to lipids in this cell system. Inhibitors of advanced lipooxidation end products (ALEs) formation such as aminoguanidine (AG) and pyridoxamine (PM) prevented partially apoptotic events triggered by NO such as DNA fragmentation, caspase-3 activation and cytochrome c release from mitochondria. These findings indicate that ALEs are involved in NO-induced apoptosis. In fact, NO-induced carbonylation of PARP protein preceded its apoptotic degradation and inhibitors of ALEs formation prevented both events. We thus propose that carbonylation of proteins is instrumental in linking NO-dependent lipid oxidation and apoptosis in this cell system.

  4. Anti-apoptotic mechanism of Bacoside rich extract against reactive nitrogen species induced activation of iNOS/Bax/caspase 3 mediated apoptosis in L132 cell line.

    Science.gov (United States)

    Anand, T; Pandareesh, M D; Bhat, Pratiksha V; Venkataramana, M

    2014-10-01

    Nitric oxide is a highly reactive free radical gas that reacts with a wide range of bio-molecules to produce reactive nitrogen species and exerts nitrative stress. Bacopa monniera is a traditional folk and ayurvedic medicine known to alleviate a variety of disorders. Aim of the present study is to evaluate the protective propensity of Bacopa monniera extract (BME) through its oxido-nitrosative and anti-apoptotic mechanism to attenuate sodium nitroprusside (SNP)-induced apoptosis in a human embryonic lung epithelial cell line (L132). Our results elucidate that pre-treatment of L132 cells with BME ameliorates the mitochondrial and plasma membrane damage induced by SNP as evidenced by MTT and LDH leakage assays. BME pre-treatment inhibited NO generation by down-regulating inducible nitric oxide synthase expression. BME exhibited potent antioxidant activity by up-regulating the antioxidant enzymes. SNP-induced damage to cellular, nuclear and mitochondrial integrity was also restored by BME, which was confirmed by ROS estimation, comet assay and mitochondrial membrane potential assays respectively. BME pre-treatment efficiently attenuated the SNP-induced apoptotic biomarkers such as Bax, cytochrome-c and caspase-3, which orchestrate the proteolytic damage of the cell. By considering all these findings, we report that BME protects L132 cells against SNP-induced toxicity via its free radical scavenging and anti-apoptotic mechanism.

  5. Isorhamnetin inhibits H₂O₂-induced activation of the intrinsic apoptotic pathway in H9c2 cardiomyocytes through scavenging reactive oxygen species and ERK inactivation.

    Science.gov (United States)

    Sun, Bing; Sun, Gui-Bo; Xiao, Jing; Chen, Rong-Chang; Wang, Xin; Wu, Ying; Cao, Li; Yang, Zhi-Hong; Sun, Xiao-Bo

    2012-02-01

    As a traditional Chinese medicine, the sea buckthorn (Hippophae rhamnoides L.) has a long history in the treatment of ischemic heart disease and circulatory disorders. However, the active compounds responsible for and the underlying mechanisms of these effects are not fully understood. In this article, isorhamnetin pretreatment counteracted H(2)O(2)-induced apoptotic damage in H9c2 cardiomyocytes. Isorhamnetin did not inhibit the death receptor-dependent or extrinsic apoptotic pathways, as characterized by its absence in both caspase-8 inactivation and tBid downregulation along with unchanged Fas and TNFR1 mRNA levels. Instead, isorhamnetin specifically suppressed the mitochondria-dependent or intrinsic apoptotic pathways, as characterized by inactivation of caspase-9 and -3, maintenance of the mitochondrial membrane potential (ΔΨm), and regulation of a series of Bcl-2 family genes upstream of ΔΨm. The anti-apoptotic effects of isorhamnetin were linked to decreased ROS generation. H(2)O(2) activated ERK and p53, whereas isorhamnetin inhibited their activation. ERK overexpression overrode the isorhamnetin-induced inhibition of the intrinsic apoptotic pathway in H9c2 cardiomyocytes, which indicated that an ERK-dependent pathway was involved. Furthermore, N-acetyl cysteine (a potent ROS scavenger) could attenuate the H(2)O(2)-induced apoptosis. However, PD98059 (an ERK-specific inhibitor) could not effectively antagonize ROS generation, which indicates that ROS may be an upstream inducer of ERK. In conclusion, isorhamnetin inhibits the H(2)O(2)-induced activation of the intrinsic apoptotic pathway via ROS scavenging and ERK inactivation. Therefore, isorhamnetin is a promising reagent for the treatment of ROS-induced cardiomyopathy.

  6. Apoptotic Cells Are Cleared by Directional Migration and elmo1-Dependent Macrophage Engulfment

    NARCIS (Netherlands)

    van Ham, Tjakko J.; Kokel, David; Peterson, Randall T.

    2012-01-01

    Apoptotic cell death is essential for development and tissue homeostasis [1, 2]. Failure to clear apoptotic cells can ultimately cause inflammation and autoimmunity [3, 4]. Apoptosis has primarily been studied by staining of fixed tissue sections, and a clear understanding of the behavior of apoptot

  7. Amelioration of apoptotic events in the skeletal muscle of intra-nigrally rotenone-infused Parkinsonian rats by Morinda citrifolia--up-regulation of Bcl-2 and blockage of cytochrome c release.

    Science.gov (United States)

    Narasimhan, Kishore Kumar S; Paul, Liya; Sathyamoorthy, Yogesh Kanna; Srinivasan, Ashokkumar; Chakrapani, Lakshmi Narasimhan; Singh, Abhilasha; Ravi, Divya Bhavani; Krishnan, Thulasi Raman; Velusamy, Prema; Kaliappan, Kathiravan; Radhakrishnan, Rameshkumar; Periandavan, Kalaiselvi

    2016-02-01

    Parkinson's disease is a progressive neurodegenerative movement disorder with the cardinal symptoms of bradykinesia, resting tremor, rigidity, and postural instability, which lead to abnormal movements and lack of activity, which in turn cause muscular damage. Even though studies have been carried out to elucidate the causative factors that lead to muscular damage in Parkinson's disease, apoptotic events that occur in the skeletal muscle and a therapeutical approach to culminate the muscular damage have not been extensively studied. Thus, this study evaluates the impact of rotenone-induced SNPc lesions on skeletal muscle apoptosis and the efficacy of an ethyl acetate extract of Morinda citrifolia in safeguarding the myocytes. Biochemical assays along with apoptotic markers studied by immunoblot and reverse transcription-polymerase chain reaction in the current study revealed that the supplementation of Morinda citrifolia significantly reverted alterations in both biochemical and histological parameters in rotenone-infused PD rats. Treatment with Morinda citrifolia also reduced the expression of pro-apoptotic proteins Bax, caspase-3 and caspase-9 and blocked the release of cytochrome c from mitochondria induced by rotenone. In addition, it augmented the expression of Bcl2 both transcriptionally and translationally. Thus, this preliminary study paves a way to show that the antioxidant and anti-apoptotic activities of Morinda citrifolia can be exploited to alleviate skeletal muscle damage induced by Parkinsonism.

  8. MiR-3202 – Promoted H5V Cell Apoptosis by Directly Targeting Fas Apoptotic Inhibitory Molecule 2 (FAIM2) in High Glucose Condition

    Science.gov (United States)

    Huang, Xiaozhong; Xie, Hui; Xue, Guanhua; Ye, Meng; Zhang, Lan

    2017-01-01

    Background Vascular complications are a major concern for patients with diabetes. Endothelial cells (ECs) play a key role in vascular function. MicroRNAs (miRNAs) have been shown to play an important role in mediating EC function; miRNAs are vulnerable to hyperglycemic conditions. Previous reports verified that Fas apoptotic inhibitory molecule 2 (FAIM2) can inhibit cell apoptosis through repressing the FAS-associated death domain protein (FADD) pathway. This current study was designed to explore the potential involvement of miR-3202 in the pathogenesis of ECs in high-glucose conditions. Material/Methods The aim of this study was to investigate the role of miR-3202 in regulating hyperglycemia-induced ECs by targeting FAIM2. The endothelial cell line H5V was cultured in a high-glucose condition to induce damage to FAIM2 expression in ECs; mimic and inhibition of miR-3202 were used to enhance and depress miR-3202’s function to explore its function on FAIM2. Results Our study showed that FAIM2 was inhibited by high-glucose conditions, and miRNA-3202 was induced by high-glucose conditions. FAIM2 was identified as the target gene of miRNA-3202; luciferase reporter assays confirmed that FAIM2 was downregulated by miR-3202 directly, that is, miR-3202 can upregulate Fas/FADD through inhibiting FAIM2. Conclusions MiR-3202 can promote EC apoptosis in hyperglycemic conditions, which demonstrated that EC apoptosis induced by high-glucose conditions partly depends on miR-3202 targeting FAIM2. PMID:28228635

  9. Apoptotic cell death: its implications for imaging in the next millennium

    Energy Technology Data Exchange (ETDEWEB)

    Blankenberg, F.G. [Stanford Univ., CA (United States). Dept. of Radiology; Tait, J.F. [Dept. of Laboratory Medicine, University of Washington, Health Sciences, Seattle (United States); Strauss, H.W. [Stanford Univ., CA (United States). Dept. of Radiology; Div. of Nuclear Medicine, Stanford University School of Medicine, CA (United States)

    2000-03-01

    In this review the cellular phenomenon of apoptotic cell death and the imaging methods which can detect the process in vitro and in vivo are first discussed. Thereafter an outline is provided of the role of apoptosis in the pathophysiology of clinical disorders including stroke, neurodegenerative diseases, pulmonary inflammatory diseases, myocardial ischemia and inflammation, myelodysplastic disorders, organ transplantation, and oncology, in which imaging may play a critical role in diagnosis and patient management. Objective imaging markers of apoptosis may soon become measures of therapeutic success or failure in both current and future treatment paradigms. Since apoptosis is a major factor in many diseases, quantification and monitoring the process could become important in clinical decision making. (orig./MG) (orig.)

  10. Enhanced apoptotic response to photodynamic therapy after bcl-2 transfection.

    Science.gov (United States)

    Kim, H R; Luo, Y; Li, G; Kessel, D

    1999-07-15

    Apoptosis is a cellular death process involving the sequential activation of a series of caspases, endonucleases, and other enzymes. The initiation of apoptosis can be inhibited by overexpression of bcl-2 and certain other members of a related family of proteins. We examined the effects of bcl-2 overexpression on the apoptotic response to photodynamic therapy (PDT), using aluminum phthalocyanine as the photosensitizing agent. In this study, we compared the immortalized human breast epithelial cell line MCF10A with a subline (MCF10A/bcl-2) transfected with the human bcl-2 gene. The latter was approximately 2-fold more sensitive to the phototoxic effects of PDT. At a 50 mJ/cm2 light dose, photodamage to MCF-10A/bcl-2 resulted in a greater loss of the mitochondrial membrane potential (delta(psi)m), enhanced release of mitochondrial cytochrome c, a more rapid and greater activation of caspase-3, and a greater apoptotic response. Western blot analysis revealed that the transfected cell line showed overexpression of both bcl-2 and bax, and that PDT caused selective destruction of bcl-2, leaving bax unaffected. The greater apoptotic response by the transfected line is, therefore, attributed to the higher bax:bcl-2 ratio after photodamage.

  11. Apoptotic mimicry: an altruistic behavior in host/Leishmania interplay

    Directory of Open Access Journals (Sweden)

    Wanderley J.L.M.

    2005-01-01

    Full Text Available Apoptosis is the most common phenotype observed when cells die through programmed cell death. The morphologic and biochemical changes that characterize apoptotic cells depend on the activation of a diverse set of genes. Apoptosis is essential for multicellular organisms since their development and homeostasis are dependent on extensive cell renewal. In fact, there is strong evidence for the correlation between the emergence of multicellular organisms and apoptosis during evolution. On the other hand, no obvious advantages can be envisaged for unicellular organisms to carry the complex machinery required for programmed cell death. However, accumulating evidence shows that free-living and parasitic protozoa as well as yeasts display apoptotic markers. This phenomenon has been related to altruistic behavior, when a subpopulation of protozoa or yeasts dies by apoptosis, with clear benefits for the entire population. Recently, phosphatidylserine (PS exposure and its recognition by a specific receptor (PSR were implicated in the infectivity of amastigote forms of Leishmania, an obligatory vertebrate intramacrophagic parasite, showing for the first time that unicellular organisms use apoptotic features for the establishment and/or maintenance of infection. Here we focus on PS exposure in the outer leaflet of the plasma membrane - an early hallmark of apoptosis - and how it modulates the inflammatory activity of phagocytic cells. We also discuss the possible mechanisms by which PS exposure can define Leishmania survival inside host cells and the evolutionary implications of apoptosis at the unicellular level.

  12. Apoptotic HPV positive cancer cells exhibit transforming properties.

    Directory of Open Access Journals (Sweden)

    Emilie Gaiffe

    Full Text Available Previous studies have shown that DNA can be transferred from dying engineered cells to neighboring cells through the phagocytosis of apoptotic bodies, which leads to cellular transformation. Here, we provide evidence of an uptake of apoptotic-derived cervical cancer cells by human mesenchymal cells. Interestingly, HeLa (HPV 18+ or Ca Ski (HPV16+ cells, harboring integrated high-risk HPV DNA but not C-33 A cells (HPV-, were able to transform the recipient cells. Human primary fibroblasts engulfed the apoptotic bodies effectively within 30 minutes after co-cultivation. This mechanism is active and involves the actin cytoskeleton. In situ hybridization of transformed fibroblasts revealed the presence of HPV DNA in the nucleus of a subset of phagocytosing cells. These cells expressed the HPV16/18 E6 gene, which contributes to the disruption of the p53/p21 pathway, and the cells exhibited a tumorigenic phenotype, including an increased proliferation rate, polyploidy and anchorage independence growth. Such horizontal transfer of viral oncogenes to surrounding cells that lack receptors for HPV could facilitate the persistence of the virus, the main risk factor for cervical cancer development. This process might contribute to HPV-associated disease progression in vivo.

  13. Cell shape and organelle modification in apoptotic U937 cells

    Directory of Open Access Journals (Sweden)

    MR Montinari

    2009-12-01

    Full Text Available U937 cells induced to apoptosis, progressively and dramatically modified their cell shape by intense blebbing formation, leading to the production of apoptotic bodies. The blebs evolved with time; milder forms of blebbing involving only a region or just the cortical part of the cytoplasm were observed within the first hour of incubation with puromycin; blebbing involving the whole cell body with very deep constrictions is the most frequent event observed during late times of incubation. The ultrastructural analysis of apoptotic cells revealed characteristic features of nuclear fragmentation (budding and cleavage mode and cytoplasmatic modifications. The cytoplasm of blebs does not contain organelles, such as ribosomes or mitochondria. Scarce presence of endoplasmic reticulum can be observed at the site of bleb detachment. However, blebbing is a dispensable event as evaluated by using inhibitor of actin polymerization. In the present study, the progressive modifications of the nucleus, mitochondria, nuclear fragmentation, cytoplasmic blebs formation and production of apoptotic bodies in U937 monocytic cells induced to apoptosis by puromycin (an inhibitor of protein synthesis were simultaneously analyzed.

  14. Thymosin beta 4 protects cardiomyocytes from oxidative stress by targeting anti-oxidative enzymes and anti-apoptotic genes.

    Directory of Open Access Journals (Sweden)

    Chuanyu Wei

    Full Text Available BACKGROUND: Thymosin beta-4 (Tβ4 is a ubiquitous protein with many properties relating to cell proliferation and differentiation that promotes wound healing and modulates inflammatory mediators. The mechanism by which Tβ4 modulates cardiac protection under oxidative stress is not known. The purpose of this study is to dissect the cardioprotective mechanism of Tβ4 on H(2O(2 induced cardiac damage. METHODS: Rat neonatal cardiomyocytes with or without Tβ4 pretreatment were exposed to H(2O(2 and expression of antioxidant, apoptotic, and anti-inflammatory genes was evaluated by quantitative real-time PCR and western blotting. ROS levels were estimated by DCF-DA using fluorescent microscopy and fluorimetry. Selected antioxidant, anti-inflammatory and antiapoptotic genes were silenced by siRNA transfections in neonatal cardiomyocytes and effect of Tβ4 on H(2O(2-induced cardiac damage was evaluated. RESULTS: Pre-treatment of Tβ4 resulted in reduction of the intracellular ROS levels induced by H(2O(2 in cardiomyocytes. Tβ4 pretreatment also resulted in an increase in the expression of antiapoptotic proteins and reduction of Bax/BCl(2 ratio in the cardiomyocytes. Pretreatment with Tβ4 resulted in stimulating the expression of antioxidant enzymes copper/zinc SOD and catalase in cardiomyocytes at both transcription and translation levels. Tβ4 treatment resulted in the increased expression of anti-apoptotic and anti-inflammatory genes. Silencing of Cu/Zn SOD and catalase gene resulted in apoptotic cell death in the cardiomyocytes which was prevented by treatment with Tβ4. CONCLUSION: This is the first report that demonstrates the effect of Tβ4 on cardiomyocytes and its capability to selectively upregulate anti-oxidative enzymes, anti-inflammatory genes, and antiapoptotic enzymes in the neonatal cardiomyocytes thus preventing cell death thereby protecting the myocardium. Tβ4 treatment resulted in decreased oxidative stress and inflammation in the

  15. A distinct response to endogenous DNA damage in the development of Nbs1-deficient cortical neurons

    Institute of Scientific and Technical Information of China (English)

    Rui Li; Yun-Gui Yang; Yunzhou Gao; Zhao-Qi Wang; Wei-Min Tong

    2012-01-01

    Microcephaly is a clinical characteristic for human nijmegen breakage syndrome (NBS,mutated in NBS1 gene),a chromosomal instability syndrome.However,the underlying molecular pathogenesis remains elusive.In the present study,we demonstrate that neuronal disruption ofNBS (Nbn in mice) causes microcephaly characterized by the reduction of cerebral cortex and corpus cailosum,recapitulating neuronal anomalies in human NBS.Nbs1-deficient neocortex shows accumulative endogenous DNA damage and defective activation ofAtaxia telangiectasia and Rad3-related (ATR)-Chk1 pathway upon DNA damage.Notably,in contrast to massive apoptotic cell death in Nbs1-deficient cerebella,activation of p53 leads to a defective neuroprogenitor proliferation in neocortex,likely via specific persistent induction of hematopoietic zinc finger (Hzf) that preferentially promotes p53-mediated cell cycle arrest whilst inhibiting apoptosis.Moreover,Trp53 mutations substantially rescue the microcephaly in Nbs1-deficient mice.Thus,the present results reveal the first clue that developing neurons at different regions of brain selectively respond to endogenous DNA damage,and underscore an important role for Nbs1 in neurogenesis.

  16. Genistein suppresses the mitochondrial apoptotic pathway in hippocampal neurons in rats with Alzheimer's disease

    Directory of Open Access Journals (Sweden)

    Yan Wang

    2016-01-01

    Full Text Available Genistein is effective against amyloid-β toxicity, but the underlying mechanisms are unclear. We hypothesized that genistein may protect neurons by inhibiting the mitochondrial apoptotic pathway, and thereby play a role in the prevention of Alzheimer's disease. A rat model of Alzheimer's disease was established by intraperitoneal injection of D-galactose and intracerebral injection of amyloid-β peptide (25–35. In the genistein treatment groups, a 7-day pretreatment with genistein (10, 30, 90 mg/kg was given prior to establishing Alzheimer's disease model, for 49 consecutive days. Terminal deoxyribonucleotidyl transferase-mediated dUTP nick end labeling assay demonstrated a reduction in apoptosis in the hippocampus of rats treated with genistein. Western blot analysis showed that expression levels of capase-3, Bax and cytochrome c were decreased compared with the model group. Furthermore, immunohistochemical staining revealed reductions in cytochrome c and Bax immunoreactivity in these rats. Morris water maze revealed a substantial shortening of escape latency by genist-ein in Alzheimer's disease rats. These findings suggest that genistein decreases neuronal loss in the hippocampus, and improves learning and memory ability. The neuroprotective effects of genistein are associated with the inhibition of the mitochondrial apoptotic pathway, as shown by its ability to reduce levels of caspase-3, Bax and cytochrome c.

  17. p53 contributes to T cell homeostasis through the induction of pro-apoptotic SAP.

    Science.gov (United States)

    Madapura, Harsha S; Salamon, Daniel; Wiman, Klas G; Lain, Sonia; Klein, George; Klein, Eva; Nagy, Noémi

    2012-12-15

    Lack of functional SAP protein, due to gene deletion or mutation, is the cause of X-linked lymphoproliferative disease (XLP), characterized by functionally impaired T and NK cells and a high risk of lymphoma development. We have demonstrated earlier that SAP has a pro-apoptotic function in T and B cells. Deficiency of this function might contribute to the pathogenesis of XLP. We have also shown that SAP is a target of p53 in B cell lines. In the present study, we show that activated primary T cells express p53, which induces SAP expression. p53 is functional as a transcription factor in activated T cells and induces the expression of p21, PUMA and MDM2. PARP cleavage in the late phase of activation indicates that T cells expressing high levels of SAP undergo apoptosis. Modifying p53 levels using Nutlin-3, which specifically dissociates the MDM2-p53 interaction, was sufficient to upregulate SAP expression, indicating that SAP is a target of p53 in T cells. We also demonstrated p53's role as a transcription factor for SAP in activated T cells by ChIP assays. Our result suggests that p53 contributes to T cell homeostasis through the induction of the pro-apoptotic SAP. A high level of SAP is necessary for the activation-induced cell death that is pivotal in termination of the T cell response.

  18. Galectin-1 and Galectin-3 induce mitochondrial apoptotic pathway in Jurkat cells

    Science.gov (United States)

    Vasil'eva, O. A.; Isaeva, A. V.; Prokhorenko, T. S.; Zima, A. P.; Novitsky, V. V.

    2016-08-01

    Cellular malignant transformation is often accompanied by increased gene expression of low-molecular proteins of lectins family-galectins. But it is unknown how galectins promote tumor growth and malignization. Galectins-1 and galectin-3 are thought to be possible immunoregulators exerting their effects by regulating the balance of CD4+ lymphocytes. In addition it is known that tumor cells overexpressing galectins are capable of escaping immunological control, causing apoptosis of lymphocytes. The aim of the study is to investigate the role of galectin-1 and galectin-3 in the implementation of mitochondrial apoptotic pathway in Jurkat cells. Methods: Jurkat cells were used as a model for the study of T-lymphocytes. Jurkat cells were activated with antibodies to CD3 and CD28 and cultured with recombinant galectin-1 and -3. Apoptosis of Jurkat cells and depolarization of the mitochondrial membrane were assessed by flow cytometry. It was found that galectin-1 and galectin-3 have a dose-dependent pro-apoptotic effect on Jurkat cells in vitro and enlarge the number of cells with decreased mitochondrial membrane potential compared with intact cells.

  19. GalNAc-T14 may be involved in regulating the apoptotic action of IGFBP-3

    Indian Academy of Sciences (India)

    Chen Wu; Yaojun Shan; Xinxia Liu; Wenqian Song; Jiali Wang; Minji Zou; Min Wang; Donggang Xu

    2009-09-01

    Insulin-like growth factor binding protein-3 (IGFBP-3) is known to induce apoptosis in an insulin-like growth factor (IGF)-dependent and IGF-independent manner, but the mechanism underlying the IGF-independent effects remains unclear. Polypeptide -acetylgalactosaminyltransferase 14 (GalNAc-T14) is a novel IGFBP-3 binding partner. In this paper, small interference RNA (siRNA) targeting GalNAc-T14 was used to examine whether GalNAc-T14 affects the apoptotic action of IGFBP-3. Using semi-quantitative reverse-transcriptase polymerase chain reaction (RT-PCR) and western blot analysis, we determined that GalNAc-T14 expression was downregulated by the siRNA directed against GalNAc-T14. Apoptosis analysis of IGFBP-3-overexpressing cells treated with siRNA against GalNAc-T14 was performed to determine if GalNAc-T14 was specifically involved in IGFBP-3 signalling. The results, as determined by flow cytometric analysis and caspase-3 assay, showed that the extent of apoptosis induced by IGFBP-3 increased with RNA interference (RNAi) knockdown of GalNAc-T14. Our data suggest that GalNAc-T14 influences the apoptotic action of IGFBP-3 and might mediate the signalling pathway of IGFBP-3. Experiments to determine the role of GalNAc-T14 in the regulation of apoptosis induced by IGFBP-3 are under way.

  20. Genistein suppresses the mitochondrial apoptotic pathway in hippocampal neurons in rats with Alzheimer’s disease

    Institute of Scientific and Technical Information of China (English)

    Yan Wang; Biao Cai; Jing Shao; Ting-ting Wang; Run-ze Cai; Chang-ju Ma; Tao Han; Jun Du

    2016-01-01

    Genistein is effective against amyloid-βtoxicity, but the underlying mechanisms are unclear. We hypothesized that genistein may protect neurons by inhibiting the mitochondrial apoptotic pathway, and thereby play a role in the prevention of Alzheimer’s disease. A rat model of Alzheimer’s disease was established by intraperitoneal injection of D-galactose and intracerebral injection of amyloid-βpeptide (25–35). In the genistein treatment groups, a 7-day pretreatment with genistein (10, 30, 90 mg/kg) was given prior to establishing Alzheimer’s dis-ease model, for 49 consecutive days. Terminal deoxyribonucleotidyl transferase-mediated dUTP nick end labeling assay demonstrated a reduction in apoptosis in the hippocampus of rats treated with genistein. Western blot analysis showed that expression levels of capase-3, Bax and cytochrome c were decreased compared with the model group. Furthermore, immunohistochemical staining revealed reductions in cytochrome c and Bax immunoreactivity in these rats. Morris water maze revealed a substantial shortening of escape latency by genist-ein in Alzheimer’s disease rats. These ifndings suggest that genistein decreases neuronal loss in the hippocampus, and improves learning and memory ability. The neuroprotective effects of genistein are associated with the inhibition of the mitochondrial apoptotic pathway, as shown by its ability to reduce levels of caspase-3, Bax and cytochrome c.

  1. Malignant mixed Mullerian tumors of the uterus: histopathological evaluation of cell cycle and apoptotic regulatory proteins

    Directory of Open Access Journals (Sweden)

    Senger Jenna-Lynn B

    2010-07-01

    Full Text Available Abstract Aim The aim of our study was to evaluate survival outcomes in malignant mixed Mullerian tumors (MMMT of the uterus with respect to the role of cell cycle and apoptotic regulatory proteins in the carcinomatous and sarcomatous components. Methods 23 cases of uterine MMMT identified from the Saskatchewan Cancer Agency (1970-1999 were evaluated. Immunohistochemical expression of Bad, Mcl-1, bcl-x, bak, mdm2, bax, p16, p21, p53, p27, EMA, Bcl-2, Ki67 and PCNA was correlated with clinico-pathological data including survival outcomes. Results Histopathological examination confirmed malignant epithelial component with homologous (12 cases and heterologous (11 cases sarcomatous elements. P53 was strongly expressed (70-95% in 15 cases and negative in 5 cases. The average survival in the p53+ve cases was 3.56 years as opposed to 8.94 years in p53-ve cases. Overexpression of p16 and Mcl-1 were observed in patients with longer survival outcomes (> 2 years. P16 and p21 were overexpressed in the carcinomatous and sarcomatous elements respectively. Cyclin-D1 was focally expressed only in the carcinomatous elements. Conclusions Our study supports that a cell cycle and apoptotic regulatory protein dysregulation is an important pathway for tumorigenesis and b p53 is an important immunoprognostic marker in MMMT of the uterus.

  2. Gene Expression Profiling in Apoptotic K562 Cells Treated by Homoharringtonine

    Institute of Scientific and Technical Information of China (English)

    Wei JIN; Jiong WU; Zhigang ZHUANG; Junjie Li; Fei FEI; Genhong DI; Ying CHEN; Ming YAO; Zhimin SHAO

    2007-01-01

    Gene chip technology was used to determine the gene expression profiles in apoptotic K562 cells induced by homoharringtonine. The expression of forty-four mRNAs was found to be changed significantly were identified after screening with a gene chip capable of detecting 14,218 different human mRNA species simultaneously. Of these genes, 17 were up-regulated and 27 were down-regulated.Most of them were found to be related to apoptosis, oncogenes, or tumor suppression. Several genes with altered gene expression, such as human transforming growth factor-beta inducible early protein gene (TIEG), vitamin D3 upregulated protein 1 gene (VDUP1), RNA binding motif protein 4 gene (RBM4) and v-myc myelocytomatosis viral oncogene homolog (C-MYC), were confirmed by Northern blot analysis.According to the dynamic gene expression pattern in these apoptotic cells, the activated transforming growth factor-β and tumor necrosis factor signaling pathways play an important role in homoharringtonine-induced apoptosis. TIEG was significantly altered after apoptosis induction, it should be critical for apoptosis signal transmission.

  3. GalNAc-T14 may be involved in regulating the apoptotic action of IGFBP-3.

    Science.gov (United States)

    Wu, Chen; Shan, Yaojun; Liu, Xinxia; Song, Wenqian; Wang, Jiali; Zou, Minji; Wang, Min; Xu, Donggang

    2009-09-01

    Insulin-like growth factor binding protein-3 (IGFBP-3) is known to induce apoptosis in an insulin-like growth factor (IGF)-dependent and IGF-independent manner, but the mechanism underlying the IGF-independent effects remains unclear. Polypeptide N-acetylgalactosaminyltransferase 14 (GalNAc-T14) is a novel IGFBP-3 binding partner. In this paper, small interference RNA (siRNA) targeting GalNAc-T14 was used to examine whether GalNAc-T14 affects the apoptotic action of IGFBP-3. Using semi-quantitative reverse-transcriptase polymerase chain reaction (RT-PCR) and western blot analysis, we determined that GalNAc-T14 expression was downregulated by the siRNA directed against GalNAc-T14. Apoptosis analysis of IGFBP-3-overexpressing cells treated with siRNA against GalNAc-T14 was performed to determine if GalNAc-T14 was specifically involved in IGFBP-3 signalling. The results, as determined by flow cytometric analysis and caspase-3 assay, showed that the extent of apoptosis induced by IGFBP-increased with RNA interference (RNAi) knockdown of GalNAc-T14. Our data suggest that GalNAc-T14 influences the apoptotic action of IGFBP-3 and might mediate the signalling pathway of IGFBP-3. Experiments to determine the role of GalNAc-T14 in the regulation of apoptosis induced by IGFBP-3 are under way.

  4. Bifidobacterium breve reduces apoptotic epithelial cell shedding in an exopolysaccharide and MyD88-dependent manner

    Science.gov (United States)

    Hughes, K. R.; Harnisch, L. C.; Alcon-Giner, C.; Mitra, S.; Wright, C. J.; Ketskemety, J.

    2017-01-01

    Certain members of the microbiota genus Bifidobacterium are known to positively influence host well-being. Importantly, reduced bifidobacterial levels are associated with inflammatory bowel disease (IBD) patients, who also have impaired epithelial barrier function, including elevated rates of apoptotic extrusion of small intestinal epithelial cells (IECs) from villi—a process termed ‘cell shedding’. Using a mouse model of pathological cell shedding, we show that mice receiving Bifidobacterium breve UCC2003 exhibit significantly reduced rates of small IEC shedding. Bifidobacterial-induced protection appears to be mediated by a specific bifidobacterial surface exopolysaccharide and interactions with host MyD88 resulting in downregulation of intrinsic and extrinsic apoptotic responses to protect epithelial cells under highly inflammatory conditions. Our results reveal an important and previously undescribed role for B. breve, in positively modulating epithelial cell shedding outcomes via bacterial- and host-dependent factors, supporting the notion that manipulation of the microbiota affects intestinal disease outcomes. PMID:28123052

  5. Cell cycle re-entry mechanisms after DNA damage checkpoints Giving it some gas to shut off the breaks!

    NARCIS (Netherlands)

    van Vugt, Marcel A. T. M.; Yaffe, Michael B.

    2010-01-01

    In order to maintain genetic integrity, cells are equipped with cell cycle checkpoints that detect DNA damage, orchestrate repair, and if necessary, eliminate severely damaged cells by inducing apoptotic cell death. The mitotic machinery is now emerging as an important determinant of the cellular re

  6. Differential role of hydrogen peroxide and organic hydroperoxides in augmenting ferric nitrilotriacetate (Fe-NTA)-mediated DNA damage: implications for carcinogenesis.

    Science.gov (United States)

    Iqbal, Mohammad; Sharma, Som Datta; Mizote, Akiko; Fujisawa, Masayoshi; Okada, Shigeru

    2003-01-01

    An iron chelate, ferric nitrilotriacetate (Fe-NTA), is a potent nephrotoxic agent, and induces acute and subacute renal proximal tubular necrosis, a consequence of the Fenton-like reaction that eventually leads to a high incidence of renal adenocarcinoma in rodents. In order to examine the possible mechanism for carcinogenic activity, we investigated the DNA damage with Fe-NTA in the presence of various peroxides/organic hydroperoxides. S1 nuclease hydrolysis and deoxyribose degradation assays were performed. Incubation of calf thymus DNA with ferric nitrilotriacetate (0.1 mM) in the presence of peroxides/organic hydroperoxides at a final concentration of 40 mM of each in phosphate buffer (0.1 M, pH 7.4) augmented DNA damage severalfold as compared to the damage caused by individual treatments. Fe-NTA in the presence of hydrogen peroxide caused DNA single-strand breaks and damage to its deoxyribose sugar moiety as measured, respectively, by S1 nuclease hydrolysis and deoxyribose degradation using calf thymus DNA. However, only deoxyribose degradation could be recorded in the presence of other peroxide/organic hydroperoxides. No DNA single-strand break was observed by this treatment. The observed differences in DNA damage by hydrogen peroxide and organic hydroperoxides/peroxide have been ascribed to the differential reactivity of DNA with hydroxyl and alkoxy/aryloxy free radicals produced, respectively, from these inorganic and organic peroxides. These studies suggest that Fe-NTA not only mediated the production of reactive oxygen species, but also catalysed the decomposition of these peroxides and organic hydroperoxides, which may cause a clastogenic change in DNA. This reactivity enhances the clastogenic activity in DNA. These changes in the DNA structure may ultimately be responsible, at least in part, for the induction of carcinogenesis in Fe-NTA-exposed animals.

  7. Neuroprotection with metformin and thymoquinone against ethanol-induced apoptotic neurodegeneration in prenatal rat cortical neurons

    Directory of Open Access Journals (Sweden)

    Ullah Ikram

    2012-01-01

    Full Text Available Abstract Background Exposure to ethanol during early development triggers severe neuronal death by activating multiple stress pathways and causes neurological disorders, such as fetal alcohol effects or fetal alcohol syndrome. This study investigated the effect of ethanol on intracellular events that predispose developing neurons for apoptosis via calcium-mediated signaling. Although the underlying molecular mechanisms of ethanol neurotoxicity are not completely determined, mitochondrial dysfunction, altered calcium homeostasis and apoptosis-related proteins have been implicated in ethanol neurotoxicity. The present study was designed to evaluate the neuroprotective mechanisms of metformin (Met and thymoquinone (TQ during ethanol toxicity in rat prenatal cortical neurons at gestational day (GD 17.5. Results We found that Met and TQ, separately and synergistically, increased cell viability after ethanol (100 mM exposure for 12 hours and attenuated the elevation of cytosolic free calcium [Ca2+]c. Furthermore, Met and TQ maintained normal physiological mitochondrial transmembrane potential (ΔψM, which is typically lowered by ethanol exposure. Increased cytosolic free [Ca2+]c and lowered mitochondrial transmembrane potential after ethanol exposure significantly decreased the expression of a key anti-apoptotic protein (Bcl-2, increased expression of Bax, and stimulated the release of cytochrome-c from mitochondria. Met and TQ treatment inhibited the apoptotic cascade by increasing Bcl-2 expression. These compounds also repressed the activation of caspase-9 and caspase-3 and reduced the cleavage of PARP-1. Morphological conformation of cell death was assessed by TUNEL, Fluoro-Jade-B, and PI staining. These staining methods demonstrated more cell death after ethanol treatment, while Met, TQ or Met plus TQ prevented ethanol-induced apoptotic cell death. Conclusion These findings suggested that Met and TQ are strong protective agents against ethanol

  8. Nitric oxide (NO)-mediated mitochondrial damage plays a critical role in T-2 toxin-induced apoptosis and growth hormone deficiency in rat anterior pituitary GH3 cells.

    Science.gov (United States)

    Liu, Xianglian; Guo, Pu; Liu, Aimei; Wu, Qinghua; Xue, Xijuan; Dai, Menghong; Hao, Haihong; Qu, Wei; Xie, Shuyu; Wang, Xu; Yuan, Zonghui

    2017-04-01

    T-2 toxin, a major compound of trichothecenes, induces cell apoptosis and growth hormone (GH) deficiency and causes considerable growth retardation in animals and human cells. However, the mechanism underlying its growth suppression still remains unclear. Recent studies have suggested that ROS induced cell apoptosis and animal feed intake reduction, but there are limited reports on the role of RNS in T-2 toxin-mediated mitochondrial damage, cell apoptosis and growth retardation. Herein, T-2 toxin-induced GH3 cell damage and apoptosis were tested by MTT assay, LDH leakage and flow cytometry, respectively. Intracellular NO and antioxidant enzyme activity, ΔΨm, morphometric changes of mitochondria, the caspase pathway, and inflammatory factors were investigated. Free radical scavengers NAC, SOD and NO scavenger haemoglobin were used to explore the role of oxidative stress and the relationship between NO production and caspase pathway. The results clearly revealed that T-2 toxin caused significant increases in NO generation, cell apoptosis, GH deficiency, increased iNOS activity, upregulation of inflammatory factors and caspase pathway, decreases in ΔΨm and morphosis damage. These data suggest that mitochondria are a primary target of T-2 toxin-induced NO, and NO is a key mediator of T-2 toxin-induced cell apoptosis and GH deficiency via the mitochondria-dependent pathway in cells.

  9. Endogenous c-Myc is essential for p53-induced apoptosis in response to DNA damage in vivo.

    Science.gov (United States)

    Phesse, T J; Myant, K B; Cole, A M; Ridgway, R A; Pearson, H; Muncan, V; van den Brink, G R; Vousden, K H; Sears, R; Vassilev, L T; Clarke, A R; Sansom, O J

    2014-06-01

    Recent studies have suggested that C-MYC may be an excellent therapeutic cancer target and a number of new agents targeting C-MYC are in preclinical development. Given most therapeutic regimes would combine C-MYC inhibition with genotoxic damage, it is important to assess the importance of C-MYC function for DNA damage signalling in vivo. In this study, we have conditionally deleted the c-Myc gene in the adult murine intestine and investigated the apoptotic response of intestinal enterocytes to DNA damage. Remarkably, c-Myc deletion completely abrogated the immediate wave of apoptosis following both ionizing irradiation and cisplatin treatment, recapitulating the phenotype of p53 deficiency in the intestine. Consistent with this, c-Myc-deficient intestinal enterocytes did not upregulate p53. Mechanistically, this was linked to an upregulation of the E3 Ubiquitin ligase Mdm2, which targets p53 for degradation in c-Myc-deficient intestinal enterocytes. Further, low level overexpression of c-Myc, which does not impact on basal levels of apoptosis, elicited sustained apoptosis in response to DNA damage, suggesting c-Myc activity acts as a crucial cell survival rheostat following DNA damage. We also identify the importance of MYC during DNA damage-induced apoptosis in several other tissues, including the thymus and spleen, using systemic deletion of c-Myc throughout the adult mouse. Together, we have elucidated for the first time in vivo an essential role for endogenous c-Myc in signalling DNA damage-induced apoptosis through the control of the p53 tumour suppressor protein.

  10. Irradiation damage

    Energy Technology Data Exchange (ETDEWEB)

    Howe, L.M

    2000-07-01

    There is considerable interest in irradiation effects in intermetallic compounds from both the applied and fundamental aspects. Initially, this interest was associated mainly with nuclear reactor programs but it now extends to the fields of ion-beam modification of metals, behaviour of amorphous materials, ion-beam processing of electronic materials, and ion-beam simulations of various kinds. The field of irradiation damage in intermetallic compounds is rapidly expanding, and no attempt will be made in this chapter to cover all of the various aspects. Instead, attention will be focused on some specific areas and, hopefully, through these, some insight will be given into the physical processes involved, the present state of our knowledge, and the challenge of obtaining more comprehensive understanding in the future. The specific areas that will be covered are: point defects in intermetallic compounds; irradiation-enhanced ordering and irradiation-induced disordering of ordered alloys; irradiation-induced amorphization.

  11. Roles of Treg/Th17 Cell Imbalance and Neuronal Damage in the Visual Dysfunction Observed in Experimental Autoimmune Optic Neuritis Chronologically.

    Science.gov (United States)

    Liu, Yuanyuan; You, Caiyun; Zhang, Zhuhong; Zhang, Jingkai; Yan, Hua

    2015-12-01

    Optic neuritis associated with multiple sclerosis and its animal model, experimental autoimmune optic neuritis (EAON), is characterized by inflammation, T cell activation, demyelination, and neuronal damage, which might induce permanent vision loss. Elucidating the chronological relationship among the features is critical for treatment of demyelinating optic neuritis. EAON was induced in C57BL/6 mice immunized with myelin oligodendrocyte glycoprotein subcutaneously, and visual function was assessed by flash-visual evoked potential (F-VEP) at days 7, 11, 14, 19, 23, 28 post-immunization. Retinal ganglion cell (RGC) apoptosis was measured by terminal-deoxynucleotidyl transferase-mediated nick-end labeling. Demyelination and axonal damage were verified with myelin basic protein (MBP) and β-amyloid precursor protein staining, respectively. Real-time polymerase chain reaction quantified IL-17, IL-1β, TGF-β, FoxP3, IL-6, and IL-10 mRNA expression in the optic nerve, as well as FoxP3 and IL-17 staining. Systemic changes of Th17 and Treg cells were tested by flow cytometry in spleen. F-VEP latency was prolonged at 11 days and peaked at 23 days commensurate with demyelination. However, F-VEP amplitude was reduced at 11 days, preceding axon damage, and was exacerbated at 23 days when a peak in RGC apoptosis was detected. Th17 cells up-regulated as early as 7 days and peaked at 11 days, while Treg cells down-regulated inversely compared to Th17 cells change as verified by IL-17 and FoxP3 expression; spleen cell samples were slightly different, demonstrating marked changed at 14 days. Treg/Th17 cell imbalance in the optic nerve precedes and may initiate neuronal damage of axons and RGCs. These changes are commensurate with the appearances of visual dysfunction reflected in F-VEP and hence may offer a novel therapeutic avenue for vision preservation.

  12. Echinacoside induces apoptotic cancer cell death by inhibiting the nucleotide pool sanitizing enzyme MTH1

    Directory of Open Access Journals (Sweden)

    Dong L

    2015-12-01

    Full Text Available Liwei Dong,1 Hongge Wang,1 Jiajing Niu,1 Mingwei Zou,2 Nuoting Wu,1 Debin Yu,1 Ye Wang,1 Zhihua Zou11Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, Jilin Province, People’s Republic of China; 2Department of Psychology, College of Liberal Arts and Social Sciences, University of Houston, Houston, TX, USA Abstract: Inhibition of the nucleotide pool sanitizing enzyme MTH1 causes extensive oxidative DNA damages and apoptosis in cancer cells and hence may be used as an anticancer strategy. As natural products have been a rich source of medicinal chemicals, in the present study, we used the MTH1-catalyzed enzymatic reaction as a high-throughput in vitro screening assay to search for natural compounds capable of inhibiting MTH1. Echinacoside, a compound derived from the medicinal plants Cistanche and Echinacea, effectively inhibited the catalytic activity of MTH1 in an in vitro assay. Treatment of various human cancer cell lines with Echinacoside resulted in a significant increase in the cellular level of oxidized guanine (8-oxoguanine, while cellular reactive oxygen species level remained unchanged, indicating that Echinacoside also inhibited the activity of cellular MTH1. Consequently, Echinacoside treatment induced an immediate and dramatic increase in DNA damage markers and upregulation of the G1/S-CDK inhibitor p21, which were followed by marked apoptotic cell death and cell cycle arrest in cancer but not in noncancer cells. Taken together, these studies identified a natural compound as an MTH1 inhibitor and suggest that natural products can be an important source of anticancer agents. Keywords: Echinacoside, MTH1, 8-oxoG, DNA damage, apoptosis, cell cycle arrest

  13. Short-term inhibition of TERT induces telomere length-independent cell cycle arrest and apoptotic response in EBV-immortalized and transformed B cells

    Science.gov (United States)

    Celeghin, Andrea; Giunco, Silvia; Freguja, Riccardo; Zangrossi, Manuela; Nalio, Silvia; Dolcetti, Riccardo; De Rossi, Anita

    2016-01-01

    Besides its canonical role in stabilizing telomeres, telomerase reverse transcriptase (TERT) may promote tumorigenesis through extra-telomeric functions. The possible therapeutic effects of BIBR1532 (BIBR), a powerful TERT inhibitor, have been evaluated in different cellular backgrounds, but no data are currently available regarding Epstein–Barr virus (EBV)-driven B-cell malignancies. Our aim was to characterize the biological effects of TERT inhibition by BIBR on EBV-immortalized lymphoblastoid cell lines (LCLs) and fully transformed Burkitt's lymphoma (BL) cell lines. We found that BIBR selectively inhibits telomerase activity in TERT-positive 4134/Late and 4134/TERT+ LCLs and EBV-negative BL41 and EBV-positive BL41/B95.8 BL cell lines. TERT inhibition led to decreased cell proliferation, accumulation of cells in the S-phase and ultimately to increased apoptosis, compared with mock-treated control cells. All these effects occurred within 72 h and were not observed in BIBR-treated TERT-negative 4134/TERT- and U2OS cells. The cell cycle arrest and apoptosis, consequent upon short-term TERT inhibition, were associated with and likely dependent on the activation of the DNA damage response (DDR), highlighted by the increased levels of γH2AX and activation of ATM and ATR pathways. Analyses of the mean and range of telomere lengths and telomere dysfunction-induced foci indicated that DDR after short-term TERT inhibition was not related to telomere dysfunction, thus suggesting that TERT, besides stabilizing telomere, may protect DNA via telomere-independent mechanisms. Notably, TERT-positive LCLs treated with BIBR in combination with fludarabine or cyclophosphamide showed a significant increase in the number of apoptotic cells with respect to those treated with chemotherapeutic agents alone. In conclusion, TERT inhibition impairs cell cycle progression and enhances the pro-apoptotic effects of chemotherapeutic agents in TERT-positive cells. These results support new

  14. Effect of ionizing radiation on hematopoietic stem cells and progenitor cells: Role of apoptosis and potential therapeutic significance of anti-apoptotic treatments; Effet des rayonnements ionisants sur les cellules souches et progeniteurs hematopoietiques : place de l'apoptose et interet therapeutique potentiel des traitements antiapoptotiques

    Energy Technology Data Exchange (ETDEWEB)

    Drouet, M.; Mourcin, F.; Grenier, N.; Mayol, J.F.; Leroux, V. [Unite de Radiohematologie experimentale, Centre de Recherches du Service de Sante des Armees, La Tronche CEDEX (France); Sotto, J.J. [Inst. Albert Bonniot, La Tronche (France); Herodin, F. [Unite de Radiohematologie experimentale, Centre de Recherches du Service de Sante des Armees, La Tronche CEDEX (France)

    2002-07-01

    Bone marrow aplasia observed following ionizing radiation exposure (Total Body Irradiation; gamma dose range: 2-10 Gy) is a result, in particular, of the radiation-induced (RI) apoptosis in hematopoietic stem and progenitor cells (HSPC). We have previously shown in a baboon model of mobilized peripheral blood CD34{sup +} cell irradiation in vitro that RI apoptosis in HSPC was an early event, mostly occurring within the first 24 hours, which involves the CD95 Fas pathway. Apoptosis may be significantly reduced with a combination of 4 cytokines (4F): Stem Cell Factor (SCF), FLT-3 Ligand (FL), thrombopoietin (TPO), and interleukin-3 (IL-3), each at 50 ng{center_dot}mL{sup -1} (15% survival versus <3% untreated cells, 24 h post-irradiation at 2.5 Gy). In this study we show that addition of TNF-{alpha}(800 IU/ml) induces an increase in 4F efficacy in terms of cell survival 24 h after incubation (26% survival after 24 h irradiation exposure at 2.5 Gy) and amplification (k) of CD34{sup +} cells after 6 days in a serum free culture medium (SFM) (k{sub CD34{sup +}} = 4.3 and 6.3 respectively for 4F and successive 4F + TNF-{alpha}/4F treatments). In addition, the 4F combination allows culture on pre-established allogenic irradiated stromal cells in vitro at 4 Gy (k{sub CD34{sup +}} = 4.5). Overall this study suggests (i) the potential therapeutic interest for an early administration of anti-apoptotic cytokines with or without hematopoiesis inhibitors (emergency cytokine therapy) and (ii) the feasibility in the accidentally irradiated individual, of autologous cell therapy based on ex vivo expansion in order to perform autograft of residual HSPC collected after the accident. (author)

  15. MicroRNAs regulate mitochondrial apoptotic pathway in myocardial ischemia-reperfusion-injury.

    Science.gov (United States)

    Makhdoumi, Pouran; Roohbakhsh, Ali; Karimi, Gholamreza

    2016-12-01

    MicroRNAs (miRNAs) are small non-coding RNAs that act as post-transcriptional gene regulators. They are involved in the pathogenesis of different disorders including heart diseases. MiRNAs contribute to ischemia/reperfusion injury (I/RI) by altering numerous key signaling elements. Together with alterations in the various potential signaling pathways, modification in miRNA expression has been suggested as a part of the response network following ischemia/reperfusion (I/R). In addition, cardiac mitochondrial homeostasis is closely associated with cardiac function and impairment of mitochondrial activity occurred after ischemia/reperfusion injury. MiRNAs play a key role in the regulation of mitochondrial apoptotic pathway and signaling proteins. In this review, we summarize the knowledge currently available regarding the molecular mechanisms of miRNA-regulated mitochondrial functions during ischemia/reperfusion injury. This regulation occurs in different stages of mitochondrial apoptosis pathway.

  16. Apoptotic neuron-secreted HN12 inhibits cell apoptosis in Hirschsprung’s disease

    Science.gov (United States)

    Du, Chunxia; Xie, Hua; Zang, Rujin; Shen, Ziyang; Li, Hongxing; Chen, Pingfa; Xu, Xiaoqun; Xia, Yankai; Tang, Weibing

    2016-01-01

    Perturbation in apoptosis can lead to Hirschsprung’s disease (HSCR), which is a genetic disorder of neural crest development. It is believed that long noncoding RNAs (lncRNAs) play a role in the progression of HSCR. This study shows that apoptotic neurons can suppress apoptosis of nonapoptotic cells by secreting exosomes that contain high levels of HN12 lncRNA. Elevated exogenous HN12 in nonapoptotic cells effectively inhibited cell apoptosis by maintaining the function of mitochondria, including the production of ATP and the release of cytochrome C. These results demonstrate that secreted lncRNAs may serve as signaling molecules mediating intercellular communication in HSCR. In addition, high HN12 levels in the circulation worked as a biomarker for predicting HSCR, providing a potential, novel, noninvasive diagnostic approach for early screening of HSCR. PMID:27853370

  17. Pro-apoptotic signaling induced by photo-oxidative ER stress is amplified by Noxa, not Bim.

    Science.gov (United States)

    Verfaillie, Tom; van Vliet, Alexander; Garg, Abhishek D; Dewaele, Michael; Rubio, Noemi; Gupta, Sanjeev; de Witte, Peter; Samali, Afshin; Agostinis, Patrizia

    2013-08-30

    Pro-apoptotic signaling instigated by endoplasmic reticulum (ER) stress is tightly governed by the BH3-only proteins like Noxa and Bim, which help trigger apoptosis, in part by inactivating mitochondria protecting proteins like Mcl-1. Bim/Noxa-based pro-apoptotic signaling has been implicated for various ER stressors but not yet for those causing "ER-focused" production of severe oxidative stress. In the present study we found that photo-oxidative (phox)-ER stress induced by hypericin-based photodynamic therapy is associated with activation of PERK (an ER sessile, stress sensor), robust induction of CHOP (a pro-apoptotic transcription factor) and induction of Bim and Noxa (accompanied by an eventual drop in Mcl-1 levels). Interestingly Noxa, but not Bim, contributed toward phox-ER stress induced apoptosis, regulated by PERK in a CHOP-independent, temporally-defined manner. These observations shed further light on complex signaling pathways elicited byphox-ER stress and vouch for directing more investigation toward the role of PERK in cell death governance.

  18. Activation of mitochondria-mediated apoptotic pathway in tri-ortho-cresyl phosphate-induced delayed neuropathy.

    Science.gov (United States)

    Zou, Chaoshuang; Kou, Ruirui; Gao, Yuan; Xie, Keqin; Song, Fuyong

    2013-06-01

    Previous studies suggest that abnormal neurons death has been implicated in organophosphate-induced delayed neuropathy (OPIDN). However, the precise mechanism of neuronal death in OPIDN remains largely unknown. In this study, adult hens were treated with a dosage of 750 mg/kg tri-ortho-cresyl phosphate (TOCP) by gavage, and then sacrificed on the time-points of 1, 5, 10, and 21 days after dosing TOCP, respectively. The apoptotic change of spinal cord neurons induced by TOCP was examined, and the role of mitochondria-mediated apoptosis of neurons during OPIDN was investigated. TUNEL assays showed that apoptotic neurons in hen spinal cords began to appear on day 5 following TOCP exposure. Immunohistochemistry and western blot analysis revealed a translocation of cytochrome C from mitochondria to cytoplasm after dosing TOCP. Moreover, the level of Bcl-2, Bcl-xl, Pro-caspase3 and Pro-caspase9 in hen spinal cord was significantly decreased, whereas that of Bax and cleaved-PARP was significantly elevated. Taken together, these findings indicate that the administration of TOCP can induce neuron apoptosis in hen spinal cords, which might be mediated by the activation of mitochondrial apoptotic pathway.

  19. Heterogeneous nuclear ribonucleoprotein K represses the production of pro-apoptotic Bcl-xS splice isoform.

    Science.gov (United States)

    Revil, Timothée; Pelletier, Jordan; Toutant, Johanne; Cloutier, Alexandre; Chabot, Benoit

    2009-08-01

    The Bcl-x pre-mRNA is alternatively spliced to produce the anti-apoptotic Bcl-x(L) and the pro-apoptotic Bcl-x(S) isoforms. By performing deletion mutagenesis on a human Bcl-x minigene, we have identified a novel exonic element that controls the use of the 5' splice site of Bcl-x(S). The proximal portion of this element acts as a repressor and is located downstream of an enhancer. Further mutational analysis provided a detailed topological map of the regulatory activities revealing a sharp transition between enhancer and repressor sequences. Portions of the enhancer can function when transplanted in another alternative splicing unit. Chromatography and immunoprecipitation assays indicate that the silencer element interacts with heterogeneous ribonucleoprotein particle (hnRNP) K, consistent with the presence of putative high affinity sites for this protein. Finally, down-regulation of hnRNP K by RNA interference enhanced splicing to Bcl-x(S), an effect seen only when the sequences bound by hnRNP K are present. Our results therefore document a clear role for hnRNP K in preventing the production of the pro-apoptotic Bcl-x(S) splice isoform.

  20. Caffeine Induces Cell Death via Activation of Apoptotic Signal and Inactivation of Survival Signal in Human Osteoblasts

    Directory of Open Access Journals (Sweden)

    Wen-Hsiung Chan

    2008-05-01

    Full Text Available Caffeine consumption is a risk factor for osteoporosis, but the precise regulatory mechanisms are currently unknown. Here, we show that cell viability decreases in osteoblasts treated with caffeine in a dose-dependent manner. This cell death is attributed primarily to apoptosis and to a smaller extent, necrosis. Moreover, caffeine directly stimulates intracellular oxidative stress. Our data support caffeine-induced apoptosis in osteoblasts via a mitochondria-dependent pathway. The apoptotic biochemical changes were effectively prevented upon pretreatment with ROS scavengers, indicating that ROS plays a critical role as an upstream controller in the caffeine-induced apoptotic cascade. Additionally, p21-activated protein kinase 2 (PAK2 and c-Jun N-terminal kinase (JNK were activated in caffeine-treated osteoblasts. Experiments further found that PAK2 activity is required for caffeine-induced JNK activation and apoptosis. Importantly, our data also show that caffeine triggers cell death via inactivation of the survival signal, including the ERK- and Akt-mediated anti-apoptotic pathways. Finally, exposure of rats to dietary water containing 10~20 μM caffeine led to bone mineral density loss. These results demonstrate for the first time that caffeine triggers apoptosis in osteoblasts via activation of mitochondria-dependent cell death signaling and inactivation of the survival signal, and causes bone mineral density loss in vivo.

  1. Immunoexpression of cleaved caspase-3 shows lower apoptotic area indices in lip carcinomas than in intraoral cancer

    Science.gov (United States)

    LEITE, Ana Flávia Schueler de Assumpção; BERNARDO, Vagner Gonçalves; BUEXM, Luisa Aguirre; da FONSECA, Eliene Carvalho; da SILVA, Licínio Esmeraldo; BARROSO, Danielle Resende Camisasca; LOURENÇO, Simone de Queiroz Chaves

    2016-01-01

    ABSTRACT Objective This study aimed to evaluate apoptosis by assessing cleaved caspase-3 immunoexpression in hyperplastic, potentially malignant disorder (PMD), and malignant tumors in intraoral and lower lip sites. Material and Methods A retrospective study using paraffin blocks with tissues from patients with inflammatory fibrous hyperplasia (IFH), actinic cheilitis, oral leukoplakia, lower lip and intraoral squamous cell carcinoma (SCC) was performed. The tissues were evaluated by immunohistochemical analysis with anti-cleaved caspase-3 antibody. Apoptotic area index was then correlated with lesion type. Results From 120 lesions assessed, 55 (46%) were cleaved caspase-3-positive. The SCC samples (n=40) had the highest apoptotic area indices (n=35; 87.5%). Significant differences were detected between SCCs and PMDs (p=0.0003), as well as SCCs and IFHs (p=0.001), regarding caspase-3 immunopositivity. Carcinomas of the lower lip had lower apoptotic area indices than intraoral cancer (p=0.0015). Conclusions Cleaved caspase-3 immunoexpression showed differences in oral SCCs and PMDs and demonstrated a distinct role of apoptosis in carcinogenesis of intraoral and lower lip cancer. In future, the expression of cleaved caspase-3 with other target molecules in oral cancer may be helpful in delineating the prognosis and treatment of these tumors. PMID:27556207

  2. Adverse effect of tannery waste leachates in transgenic Drosophila melanogaster: role of ROS in modulation of Hsp70, oxidative stress and apoptosis.

    Science.gov (United States)

    Siddique, Hifzur R; Gupta, Subash C; Mitra, Kalyan; Bajpai, Virendra K; Mathur, Neeraj; Murthy, Ramesh C; Saxena, Daya K; Chowdhuri, Debapratim K

    2008-08-01

    Leachate is a complex chemical mixture of chemicals produced as a result of leaching of solid wastes. The potential toxicity of leachates is a major environmental health concern. The present study evaluated the role of ROS in tannery leachates induced Hsp70 expression, antioxidant enzymes and apoptosis in Drosophila. Different concentrations (0.05-2.0%) of leachates prepared from tannery waste at different pH (7.00, 4.93 and 2.88) were mixed with Drosophila food and fed to the larvae for 2-48 h to examine the different stress and apoptotic markers. A concentration- and time-dependent significant increase in Hsp70 expression, ROS generation, antioxidant enzymes activities and MDA content were observed in the exposed larvae. Activities of antioxidant enzymes were delayed compared with Hsp70 expression and MDA level in the exposed organisms. Apoptotic cell death was observed in the exposed larvae at higher concentrations concurrent with a significant regression in Hsp70 along with a higher level of ROS generation. A positive correlation drawn between ROS generation and apoptotic markers and a negative correlation between apoptotic markers and Hsp70 expression at these concentrations indicated the important role of ROS in the induction of cellular damage in the exposed organisms. There was a significant generation of ROS in the larvae exposed to 0.5% of leachates which did not interfere with the protection of their cells by Hsp70 and antioxidant enzymes. However, generation of significantly higher levels of ROS in the larvae exposed to 1.0% and 2.0% leachates may decrease Hsp70 expression thus leading to mitochondria-mediated caspase-dependent apoptotic cell death.

  3. IL-17A levels in systemic lupus erythematosus associated with inflammatory markers and lower rates of malignancy and heart damage: Evidence for a dual role

    Science.gov (United States)

    Raymond, Warren; Ostli-Eilertsen, Gro; Griffiths, Sheynae; Nossent, Johannes

    2017-01-01

    Objective The interleukin 17 (IL-17) cytokine family is involved in a number of chronic inflammatory diseases. In spite of contradictory findings and a lack of causality in clinical studies, IL-17 inhibition for systemic lupus erythematosus (SLE) has regained attention as a potential therapeutic pathway, after demonstrating disease-modifying capabilities in ankylosing spondylitis. We investigated the clinical associations of interleukin 17 A (IL-17A) in patients with SLE. Material and Methods A cross-sectional study was performed involving SLE patients (n=102; age: 49 years; 86% female) recruited from a regional registry. IL-17A levels were determined by immunoassay, disease activity by Systemic Lupus Erythematosus Disease Activity Index-2K (SLEDAI-2K), and cumulative damage by Systemic Lupus International Collaborative Clinics Damage Index (SDI) scores. Non-parametric techniques were used to examine the association between IL-17A and disease activity and autoantibody profiles were compared with healthy controls (n=31): principal component analysis (PCA) was used to determine the interplay of immune cells across disease states and damage development in SLE patients. Results SLE patients had higher IgG levels, lower T-cell and B-cell counts, but median IL-17A levels did not differ from the controls (28.4 vs. 28.4 pg/mL, p=0.9). In SLE patients, IL-17A did not correlate with SLEDAI-2K or SDI, but was inversely related with age (correlation coefficients, Rs.=–0.29, phs-CRP) levels (Rs.=0.28, p<0.05), proteinuria (Rs.=0.64, p<0.05), and pre-albumin (Rs.=–0.22, p<0.05). Longitudinal data showed only modest fluctuation in IL-17A levels, independent of SLEDAI-2K. Conclusion These results suggest that IL-17A, while participating in inflammation, may also serve a protective purpose in SLE patients. PMID:28293450

  4. Role of l-carnitine in the prevention of seminiferous tubules damage induced by gamma radiation: a light and electron microscopic study

    Energy Technology Data Exchange (ETDEWEB)

    Topcu-Tarladacalisir, Yeter; Kanter, Mehmet [Trakya University, Department of Histology and Embryology, Faculty of Medicine, Edirne (Turkey); Uzal, Mustafa Cem [Trakya University, Department of Radiation Oncology, Faculty of Medicine, Edirne (Turkey)

    2009-08-15

    The present study, we hypothesized that l-carnitine can minimize germ-cell depletion and morphological features of late cell damage in the rat testis following gamma ({gamma})-irradiation. Wistar albino male rats were divided into three groups. Control group received physiological saline 0.2 ml intraperitoneally (i.p.), as placebo. Radiation group received scrotal {gamma}-irradiation of 10 Gy as a single dose plus physiological saline. Radiation + l-carnitine group received scrotal {gamma}-irradiation plus 200 mg/kg i.p. l-carnitine. l-carnitine starting 1 day before irradiation and 21 days (three times per week) after irradiation. Testis samples of the all groups were taken at day 21, 44 and 70 post-irradiation. All samples were processed at the light and electron microscopic levels. Morphologically, examination of {gamma}-irradiated testis revealed presence of marked disorganization and depletion of germ cells, arrest of spermatogenesis, formation of multinucleated giant cells, and vacuolization in the germinal epithelium. The type and extent of these changes varied at different post-treatment intervals. The damage was evident at the 21st day and reached maximum level by the 44th day. By day 44 post-irradiation, the changes were most advanced, and were associated with atrophied seminiferous tubules without germ cells, the increase in the number and size of vacuolizations in germinal epithelium, and the absent multinucleated giant cells due to spermatids had completely disappeared. The increase in nucleus invaginations, the dilatation of smooth endoplasmic reticulum cysternas and the increase in the number and size of lipid droplets in the Sertoli cells were determined at the electron microscopic level. In conclusion, l-carnitine supplementation during the radiotherapy would be effective in protecting against radiation-induced damages in rat testis, and thereby may improve the quality of patient's life after the therapy. (orig.)

  5. Natural terpenes prevent mitochondrial dysfunction, oxidative stress and release of apoptotic proteins during nimesulide-hepatotoxicity in rats.

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    Brijesh Kumar Singh

    Full Text Available Nimesulide, an anti-inflammatory and analgesic drug, is reported to cause severe hepatotoxicity. In this study, molecular mechanisms involved in deranged oxidant-antioxidant homeostasis and mitochondrial dysfunction during nimesulide-induced hepatotoxicity and its attenuation by plant derived terpenes, camphene and geraniol has been explored in male Sprague-Dawley rats. Hepatotoxicity due to nimesulide (80 mg/kg BW was evident from elevated SGPT, SGOT, bilirubin and histo-pathological changes. Antioxidants and key redox enzymes (iNOS, mtNOS, Cu/Zn-SOD, Mn-SOD, GPx and GR were altered significantly as assessed by their mRNA expression, Immunoblot analysis and enzyme activities. Redox imbalance along with oxidative stress was evident from decreased NAD(PH and GSH (56% and 74% respectively; P<0.001, increased superoxide and secondary ROS/RNS generation along with oxidative damage to cellular macromolecules. Nimesulide reduced mitochondrial activity, depolarized mitochondria and caused membrane permeability transition (MPT followed by release of apoptotic proteins (AIF; apoptosis inducing factor, EndoG; endonuclease G, and Cyto c; cytochrome c. It also significantly activated caspase-9 and caspase-3 and increased oxidative DNA damage (level of 8-Oxoguanine glycosylase; P<0.05. A combination of camphene and geraniol (CG; 1:1, when pre-administered in rats (10 mg/kg BW, accorded protection against nimesulide hepatotoxicity in vivo, as evident from normalized serum biomarkers and histopathology. mRNA expression and activity of key antioxidant and redox enzymes along with oxidative stress were also normalized due to CG pre-treatment. Downstream effects like decreased mitochondrial swelling, inhibition in release of apoptotic proteins, prevention of mitochondrial depolarization along with reduction in oxidized NAD(PH and increased mitochondrial electron flow further supported protective action of selected terpenes against nimesulide toxicity. Therefore

  6. Cytotoxic and apoptotic effects of scorpion Leiurus quinquestriatus venom on 293T and C2C12 eukaryotic cell lines

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    M. A. A. Omran

    2003-01-01

    Full Text Available Scorpion venom toxicity is of major concern due to its influence on human activities and public health. The cytotoxicity and apoptosis induced by scorpion L. quinquestriatus venom on two established eukaryotic cell lines (293T and C2C12 were analyzed. Both cultured cell lines were incubated with varying doses (10, 20, and 50 µg/ml of scorpion venom in serum free medium (SFM for 0.5, 1, 2, 4, and 8 hours at 37°C. The percentage of total lactate dehydrogenase (LDH released in the culture during venom incubation was used as an index of cell damage. Control culture was treated with an equal amount of SFM. Cell injury was recognized morphologically and apoptosis was researched by a Fluorescing Apoptosis Detection System using the principle of TUNEL (TdT-mediated dUTP Nick-End Labelling assay and confirmed by another assay concerning nuclear DNA staining with DAPI stain. Cytotoxicity was remarkable and cell survival highly reduced at the highest tested concentration (50 µg/ml. These effects were rapid and observed within 30 minutes. The apparent initial damage to the nucleus and lysis of the plasmalemma and/or organelle membranes, which was evident by a significant increase in cytosolic LDH release, suggested that this toxin acts at the membrane level. The morphological changes that occurred in apoptotic cells include condensation and compartmentalization of nuclear and cytoplasmic materials into structurally preserved membrane-bound fragments or blebs. The cytotoxic effects are dose and time dependent and cell death by apoptosis was more characteristic of 293T cells than C2C12 cells. The apoptotic effects were more prominent and clear in the early stages of toxicity, while other forms of cell damage such as swelling, rupture, and/or necrosis occurred at later stages.

  7. Different sensitivities to rocuronium of the neuromuscular junctions innervated by normal/damaged facial nerves and somatic nerve in rats: the role of the presynaptic acetylcholine quantal release

    Institute of Scientific and Technical Information of China (English)

    CHEN Jun-liang; LI Shao-qin; CHI Fang-lu; CHEN Lian-hua; LI Shi-tong

    2012-01-01

    Background Muscles present different responses to muscle relaxants,a mechanism of importance in surgeries requiring facial nerve evoked electromyography under general anaesthesia.The non-depolarizing muscle relaxants have multiple reaction formats in the neuromuscular junction,in which pre-synaptic quantal release of acetylcholine was one of the important mechanisms.This study was to compare the pre-synaptic quantal release of acetylcholine from the neuromuscular junctions innervated by normal/damaged facial nerves and somatic nerve under the effect of rocuronium in rats in vitro.Methods Acute right-sided facial nerve injury was induced by nerve crush axotomies.Both sided facial nerve connected orbicularis oris strips and tibial nerve connected gastrocnemius strips were isolated to measure endplate potentials (EPP) and miniature endplate potentials (MEPP) using an intracellular microelectrode gauge under different rocuronium concentrations.Then,the pre-synaptic quantal releases of acetylcholine were calculated by the ratios of the EPPs and the MEPPs,and compared among the damaged or normal facial nerve innervated orbicularis oris and tibial nerve innervated gastrocnemius.Results The EPP/MEPP ratios of the three neuromuscular junctions decreased in a dose dependent manner with the increase of the rocuronium concentration.With the concentrations of rocuronium being 5 μg/ml,7.5 μg/ml and 10 μg/ml,the decrease of the EPP/MEPP ratio in the damaged facial nerve group was greater than that in the normal facial nerve group.The decrease in the somatic nerve group was the biggest,with significant differences.Conclusions Rocuronium presented different levels of inhibition on the pre-synaptic quantal release of acetylcholine in the three groups of neuromuscular junctions.The levels of the inhibition showed the following sequence:somatic nerve >damaged facial nerve > normal facial nerve.The difference may be one of the reasons causing the different sensitivities to

  8. A comparison of the apoptotic effect of Delta(9)-tetrahydrocannabinol in the neonatal and adult rat cerebral cortex.

    Science.gov (United States)

    Downer, Eric J; Gowran, Aoife; Campbell, Veronica A

    2007-10-17

    The maternal use of cannabis during pregnancy results in a number of cognitive deficits in the offspring that persist into adulthood. The endocannabinoid system has a role to play in neurodevelopmental processes such as neurogenesis, migration and synaptogenesis. However, exposure to phytocannabinoids, such as Delta(9)-tetrahydrocannabinol, during gestation may interfere with these events to cause abnormal patterns of neuronal wiring and subsequent cognitive impairments. Aberrant cell death evoked by Delta(9)-tetrahydrocannabinol may also contribute to cognitive deficits and in cultured neurones Delta(9)-tetrahydrocannabinol induces apoptosis via the CB(1) cannabinoid receptor. In this study we report that Delta(9)-tetrahydrocannabinol (5-50 microM) activates the stress-activated protein kinase, c-jun N-terminal kinase, and the pro-apoptotic protease, caspase-3, in in vitro cerebral cortical slices obtained from the neonatal rat brain. The proclivity of Delta(9)-tetrahydrocannabinol to impact on these pro-apoptotic signalling molecules was not observed in in vitro cortical slices obtained from the adult rat brain. In vivo, subcutaneous administration of Delta(9)-tetrahydrocannabinol (1-30 mg/kg) activated c-jun N-terminal kinase, caspase-3 and cathepsin-D, and induced DNA fragmentation in the cerebral cortex of neonatal rats. In contrast, in vivo administration of Delta(9)-tetrahydrocannabinol to adult rats was not associated with the apoptotic pathway in the cerebral cortex. The data provide evidence which supports the hypothesis that the neonatal rat brain is more vulnerable to the neurotoxic influence of Delta(9)-tetrahydrocannabinol, suggesting that the cognitive deficits that are observed in humans exposed to marijuana during gestation may be due, in part, to abnormal engagement of the apoptotic cascade during brain development.

  9. Lipid raft-mediated Fas/CD95 apoptotic signaling in leukemic cells and normal leukocytes and therapeutic implications.

    Science.gov (United States)

    Gajate, Consuelo; Mollinedo, Faustino

    2015-11-01

    Plasma membrane is now recognized to contain tightly packed cholesterol/sphingolipid-rich domains, known as lipid or membrane rafts, which are more ordered than the surrounding lipid bilayer. Lipid rafts are crucial for the compartmentalization of signaling processes in the membrane, mostly involved in cell survival and immune response. However, in the last 15 years, a large body of evidence has also identified raft platforms as scaffolds for the recruitment and clustering of death receptor Fas/CD95 and downstream signaling molecules, leading to the concept of death-promoting lipid rafts. This raft-Fas/CD95 coclustering was first described at the early 2000s as the underlying mechanism for the proapoptotic action of the alkylphospholipid analog edelfosine in leukemic cells, hence facilitating protein-protein interactions and conveying apoptotic signals independently of Fas/CD95 ligand. Edelfosine induces apoptosis in hematologic cancer cells and activated T-lymphocytes. Fas/CD95 raft coclustering is also promoted by Fas/CD95 ligand, agonistic Fas/CD95 antibodies, and additional antitumor drugs. Thus, death receptor recruitment in rafts is a physiologic process leading to cell demise that can be pharmacologically modulated. This redistribution and local accumulation of apoptotic molecules in membrane rafts, which are usually accompanied by displacement of survival signaling molecules, highlight how alterations in the apoptosis/survival signaling balance in specialized membrane regions modulate cell fate. Membrane rafts might also modulate apoptotic and nonapoptotic death receptor signaling. Here, we discuss the role of lipid rafts in Fas/CD95-mediated apoptotic cell signaling in hematologic cancer cells and normal leukocytes, with a special emphasis on their involvement as putative therapeutic targets in cancer and autoimmune diseases.

  10. The nuclear retention of transcription factor FOXO3a correlates with a DNA damage response and increased glutamine synthetase expression by astrocytes suggesting a neuroprotective role in the ageing brain.

    Science.gov (United States)

    Fluteau, Adeline; Ince, Paul G; Minett, Thais; Matthews, Fiona E; Brayne, Carol; Garwood, Claire J; Ratcliffe, Laura E; Morgan, Sarah; Heath, Paul R; Shaw, Pamela J; Wharton, Stephen B; Simpson, Julie E

    2015-11-16

    The accumulation of reactive oxygen species leading to oxidative damage and cell death plays an important role in a number of neurodegenerative disorders. FOXO3a, the main isoform of FOXO transcription factors, mediates the cellular response to oxidative stress by regulating the expression of genes involved in DNA repair and glutamine metabolism, including glutamine synthetase (GS). Immunohistochemical investigation of the population-based neuropathology cohort of the Medical Research Council's Cognitive Function and Ageing Study (MRC CFAS) demonstrates that nuclear retention of FOXO3a significantly correlates with a DNA damage response and with GS expression by astrocytes. Furthermore, we show that GS expression correlates with increasing Alzheimer-type pathology in this ageing cohort. Our findings suggest that in response to oxidative stress, the nuclear retention of FOXO3a in astrocytes upregulates expression of GS as a neuroprotective mechanism. However, the activity of GS may be compromised by increasing levels of oxidative stress in the ageing brain resulting in dysfunctional enzyme activity, neuronal excitotoxic damage and cognitive impairment.

  11. Development of novel cyclic peptides as pro-apoptotic agents.

    Science.gov (United States)

    Brindisi, Margherita; Maramai, Samuele; Brogi, Simone; Fanigliulo, Emanuela; Butini, Stefania; Guarino, Egeria; Casagni, Alice; Lamponi, Stefania; Bonechi, Claudia; Nathwani, Seema M; Finetti, Federica; Ragonese, Francesco; Arcidiacono, Paola; Campiglia, Pietro; Valenti, Salvatore; Novellino, Ettore; Spaccapelo, Roberta; Morbidelli, Lucia; Zisterer, Daniela M; Williams, Clive D; Donati, Alessandro; Baldari, Cosima; Campiani, Giuseppe; Ulivieri, Cristina; Gemma, Sandra

    2016-07-19

    Our recent finding that paclitaxel behaves as a peptidomimetic of the endogenous protein Nur77 inspired the design of two peptides (PEP1 and PEP2) reproducing the effects of paclitaxel on Bcl-2 and tubulin, proving the peptidomimetic nature of paclitaxel. Starting from these peptide-hits, we herein describe the synthesis and the biological investigation of linear and cyclic peptides structurally related to PEP2. While linear peptides (2a,b, 3a,b, 4, 6a-f) were found inactive in cell-based assays, biological analysis revealed a pro-apoptotic effect for most of the cyclic peptides (5a-g). Cellular permeability of 5a (and also of 2a,b) on HL60 cells was assessed through confocal microscopy analysis. Further cellular studies on a panel of leukemic cell lines (HL60, Jurkat, MEC, EBVB) and solid tumor cell lines (breast cancer MCF-7 cells, human melanoma A375 and 501Mel cells, and murine melanoma B16F1 cells) confirmed the pro-apoptotic effect of the cyclic peptides. Cell cycle analysis revealed that treatment with 5a, 5c, 5d or 5f resulted in an increase in the number of cells in the sub-G0/G1 peak. Direct interaction with tubulin (turbidimetric assay) and with microtubules (immunostaining experiments) was assessed in vitro for the most promising compounds.

  12. Apoptotic and nonapoptotic function of caspase 7 in spermatogenesis.

    Science.gov (United States)

    Lei, Bin; Zhou, Xuming; Lv, Daojun; Wan, Bo; Wu, Huayan; Zhong, Liren; Shu, Fangpeng; Mao, Xiangming

    2017-01-01

    Recent studies have reported that caspase 7 has an apoptotic and nonapoptotic function. However, the relationship between caspase 7 and spermatogenesis remains unknown. This study aimed to investigate the possible function of caspase 7 during normal and abnormal spermatogenesis. The cleaved form of caspase 7 was detected in testis tissues at different postpartum times (5-14 weeks) by qRT-PCR, Western blot and immunohistochemistry (IHC). Then, the mice models of spermatogenic dysfunction were obtained by busulfan (30 mg kg-1 to further evaluate the potential function and mechanism of caspase 7. qRT-PCR and Western blot results showed that caspase 7 expression was gradually elevated from 5 to 14 weeks, which was not connected with apoptosis. IHC results revealed that caspase 7 was mainly located in spermatogenic cells and Leydig cells. In addition, spermatogenic dysfunction induced by busulfan gradually enhanced the apoptosis and elevated the expression of caspase 3, caspase 6, and caspase 9, but decreased the expression of caspase 7 in spermatogenic cells. However, when spermatogenic cells were mostly disappeared at the fourth week after busulfan treatment, caspase 7 expression in Leydig cells was significantly increased and positively correlated with the expression of caspase 3, caspase 6, and caspase 9. Therefore, these results indicate that caspase 7 has a nonapoptic function that participates in normal spermatogenesis, but also displays apoptotic function in spermatogenic dysfunction.

  13. PUMA-mediated mitochondrial apoptotic disruption by hypoxic postconditioning.

    Science.gov (United States)

    Li, YuZhen; Guo, Qi; Liu, XiuHua; Wang, Chen; Song, DanDan

    2015-08-01

    Postconditioning can reduce ischemia-reperfusion (I/R)-induced cardiomyocyte apoptosis by targeting mitochondria. p53 upregulated modulator of apoptosis (PUMA) is involved in lethal I/R injury. Here, we hypothesized that postconditioning might inhibit mitochondrial pathway-mediated cardiomyocyte apoptosis by controlling PUMA expression. The cultured neonatal rat cardiomyocytes underwent 3 h of hypoxia and 3 h of reoxygenation. Postconditioning consisted of three cycles of 5 min reoxygenation and 5 min hypoxia after prolonged hypoxia. Hypoxic postconditioning reduced the levels of PUMA mRNA and protein. Concomitantly, the loss of mitochondrial membrane potential, cytochrome c release and caspase-3 activation were decreased significantly by postconditioning. Overexpression of PUMA increased greatly not only the number of apoptotic cardiomyocytes, but also the collapse of mitochondrial membrane potential, cytochrome c release and caspase-3 activation under postconditioning condition. The data suggest that reduction of PUMA expression mediates the endogenous cardioprotective mechanisms of postconditioning by disrupting mitochondrial apoptotic pathway.

  14. A chalcone-related small molecule that induces methuosis, a novel form of non-apoptotic cell death, in glioblastoma cells

    Directory of Open Access Journals (Sweden)

    Bhanot Haymanti

    2011-06-01

    Full Text Available Abstract Background Methuosis is a unique form of non-apoptotic cell death triggered by alterations in the trafficking of clathrin-independent endosomes, ultimately leading to extreme vacuolization and rupture of the cell. Results Here we describe a novel chalcone-like molecule, 3-(2-methyl-1H- indol-3-yl-1-(4-pyridinyl-2-propen-1-one (MIPP that induces cell death with the hallmarks of methuosis. MIPP causes rapid accumulation of vacuoles derived from macropinosomes, based on time-lapse microscopy and labeling with extracellular fluid phase tracers. Vacuolization can be blocked by the cholesterol-interacting compound, filipin, consistent with the origin of the vacuoles from non-clathrin endocytic compartments. Although the vacuoles rapidly acquire some characteristics of late endosomes (Rab7, LAMP1, they remain distinct from lysosomal and autophagosomal compartments, suggestive of a block at the late endosome/lysosome boundary. MIPP appears to target steps in the endosomal trafficking pathway involving Rab5 and Rab7, as evidenced by changes in the activation states of these GTPases. These effects are specific, as other GTPases (Rac1, Arf6 are unaffected by the compound. Cells treated with MIPP lose viability within 2-3 days, but their nuclei show no evidence of apoptotic changes. Inhibition of caspase activity does not protect the cells, consistent with a non-apoptotic death mechanism. U251 glioblastoma cells selected for temozolomide resistance showed sensitivity to MIPP-induced methuosis that was comparable to the parental cell line. Conclusions MIPP might serve as a prototype for new drugs that could be used to induce non-apoptotic death in cancers that have become refractory to agents that work through DNA damage and apoptotic mechanisms.

  15. Histological, Scanning And Transmission Electron Microscopic Studies On The Possible Protective Role Of Ginger Extract Against AcrylamideInduced Intestinal Damage In Mice

    Directory of Open Access Journals (Sweden)

    Hala Galal El-Tantawi

    2007-12-01

    Full Text Available Objective: This study was carried out to evaluate the protective effect of ginger Zingeber officinale extract (ZOE against the acrylamide (AC which is an industrial chemical used in water treatment and it is synthesized during cooking of starch food at high temperature. Method: Thirty adult male albino mice, each weighs 20-25 g were divided into three groups (10 mice/group: (Icontrol group. (IIacrylamide treated group. (III acrylamide & ginger group. Acrylamide was given to experimental animals in the drinking water at a non-lethal dose of 200 p.p.m for 10 weeks (3 days/week. Ginger extract was orally administrated at 50 mg/L (~5 ml/day for 10 weeks (3 days/week. The ileum samples were collected for light microscope study and for scanning and transmission electron microscope examination. Results: This study revealed that acrylamide induces pathological changes of the ileum of the treated mice specially the absorptive epithelial cells. The scanning electron microscopic study revealed damage of the ileal villi, some red blood corpuscles appeared at the site of damage. The transmission electron microscopic examination clearly demonstrated degeneration of most cell organelles as mitochondria, deterioration and degranulation of the rough endoplasmic reticulum, dilatation of Golgi apparatus. Conclusion: The administration of ginger extract decreased the histological alterations and ensuring the anti-inflammatory, and antitoxic effects of ZOE at its chosen dosage level

  16. Kinetic Modeling Reveals the Roles of Reactive Oxygen Species Scavenging and DNA Repair Processes in Shaping the Dose-Response Curve of KBrO₃-Induced DNA Damage.

    Science.gov (United States)

    Spassova, Maria A; Miller, David J; Nikolov, Alexander S

    2015-01-01

    We have developed a kinetic model to investigate how DNA repair processes and scavengers of reactive oxygen species (ROS) can affect the dose-response shape of prooxidant induced DNA damage. We used as an example chemical KBrO3 which is activated by glutathione and forms reactive intermediates that directly interact with DNA to form 8-hydroxy-2-deoxyguanosine DNA adducts (8-OH-dG). The single strand breaks (SSB) that can result from failed base excision repair of these adducts were considered as an effect downstream from 8-OH-dG. We previously demonstrated that, in the presence of effective base excision repair, 8-OH-dG can exhibit threshold-like dose-response dependence, while the downstream SSB can still exhibit a linear dose-response. Here we demonstrate that this result holds for a variety of conditions, including low levels of GSH, the presence of additional SSB repair mechanisms, or a scavenger. It has been shown that melatonin, a terminal scavenger, inhibits KBrO3-caused oxidative damage. Our modeling revealed that sustained exposure to KBrO3 can lead to fast scavenger exhaustion, in which case the dose-response shapes for both endpoints are not substantially affected. The results are important to consider when forming conclusions on a chemical's toxicity dose dependence based on the dose-response of early genotoxic events.

  17. Comparative study of DNA damage, cell cycle and apoptosis in human K562 and CCRF-CEM leukemia cells: role of BCR/ABL in therapeutic resistance.

    Science.gov (United States)

    Pytel, Dariusz; Wysocki, Tomasz; Majsterek, Ireneusz

    2006-09-01

    The Philadelphia translocation t(9;22) resulting in the bcr/abl fusion gene is the pathogenic principle of almost 95% of human chronic myelogenous leukemia (CML). Imatinib mesylate (STI571) is a specific inhibitor of the BCR/ABL fusion tyrosine kinase that exhibits potent antileukemic effects in CML. BCR/ABL-positive K562 and -negative CCRF-CEM human leukemia cells were investigated. MTT survival assay and clonogenic test of the cell proliferation ability were used to estimate resistance against idarubicin. DNA damage after cell treatment with the drug at the concentrations from 0.001 to 3 microM with or without STI571 pre-treatment were examined by the alkaline comet assay. We found that the level of DNA damages was lower in K562 cells after STI571 pre-treatment. It is suggested that BCR/ABL activity may promote genomic instability, moreover K562 cells were found to be resistant to the drug treatment. Further, we provided evidence of apoptosis inhibition in BCR/ABL-positive cells using caspase-3 activity colorimetric assay and DAPI nuclear staining for chromatin condensation. We suggest that these processes associated with cell cycle arrest in G2/M checkpoint detected in K562 BCR/ABL-positive compared to CCRF-CEM cells without BCR/ABL expression might promote clone selection resistance to drug treatment.

  18. [Role of beta-carotene in the prevention of genotoxic damage in patients undergoing radiotherapy. Monitoring by the micronucleus test in exfoliative cells of the oral cavity].

    Science.gov (United States)

    Oldini, C; Malusardi, G; Grossi, L; Chiarelli, G

    1992-01-01

    Radiotherapic treatment of patients with carcinoma usually causes genotoxis damage. This has been studied recently using the test of micronuclei in esfoliated cells. This test presents methodologic advantages in compared with the classic citogenetic analysis and as it is carried out on esfolieted cells from the oral cavity it faithfully reflects the genotoxic damage undergone by the cells of the basal layer of the epitelium. The preliminary result obtained so far have confirmed the anticlastogenic activity of beta-carotene in fact, the frequence of micronuclei in esfolieted cells from the oral cavity in patients undergoing radiotherapy or undergoing treatment with beta-carotene is inferior to that of patients undergoing treatment with beta-carotene is inferior to that of patients undergoing radiotherapy without the subministration of carotenoids. Treatment with carotenoids does not influence the therapeutic efficiency of radiotherapy treatment. Therefore, the results seem to confirm that indirect ossidaction processes are involved in the mechanism of the clastogenic action of radiotherapia. The carotenoids seem to be able to contrast validly this undesirable effect without interfering with the desirable therapeutic effect.

  19. Infection of epithelial cells with Chlamydia trachomatis inhibits TNF-induced apoptosis at the level of receptor internalization while leaving non-apoptotic TNF-signalling intact.

    Science.gov (United States)

    Waguia Kontchou, Collins; Tzivelekidis, Tina; Gentle, Ian E; Häcker, Georg

    2016-11-01

    Chlamydia trachomatis is an obligate intracellular bacterial pathogen of medical importance. C. trachomatis develops inside a membranous vacuole in the cytosol of epithelial cells but manipulates the host cell in numerous ways. One prominent effect of chlamydial infection is the inhibition of apoptosis in the host cell, but molecular aspects of this inhibition are unclear. Tumour necrosis factor (TNF) is a cytokine with important roles in immunity, which is produced by immune cells in chlamydial infection and which can have pro-apoptotic and non-apoptotic signalling activity. We here analysed the signalling through TNF in cells infected with C. trachomatis. The pro-apoptotic signal of TNF involves the activation of caspase-8 and is controlled by inhibitor of apoptosis proteins. We found that in C. trachomatis-infected cells, TNF-induced apoptosis was blocked upstream of caspase-8 activation even when inhibitor of apoptosis proteins were inhibited or the inhibitor of caspase-8 activation, cFLIP, was targeted by RNAi. However, when caspase-8 was directly activated by experimental over-expression of its upstream adapter Fas-associated protein with death domain, C. trachomatis was unable to inhibit apoptosis. Non-apoptotic TNF-signalling, particularly the activation of NF-κB, initiates at the plasma membrane, while the activation of caspase-8 and pro-apoptotic signalling occur subsequently to internalization of TNF receptor and the formation of a cytosolic signalling complex. In C. trachomatis-infected cells, NF-κB activation through TNF was unaffected, while the internalization of the TNF-TNF-receptor complex was blocked, explaining the lack of caspase-8 activation. These results identify a dichotomy of TNF signalling in C. trachomatis-infected cells: Apoptosis is blocked at the internalization of the TNF receptor, but non-apoptotic signalling through this receptor remains intact, permitting a response to this cytokine at sites of infection.

  20. Apoptotic cell-treated dendritic cells induce immune tolerance by specifically inhibiting development of CD4⁺ effector memory T cells.

    Science.gov (United States)

    Zhou, Fang; Zhang, Guang-Xian; Rostami, Abdolmohamad

    2016-02-01

    CD4(+) memory T cells play an important role in induction of autoimmunity and chronic inflammatory responses; however, regulatory mechanisms of CD4(+) memory T cell-mediated inflammatory responses are poorly understood. Here we show that apoptotic cell-treated dendritic cells inhibit development and differentiation of CD4(+) effector memory T cells in vitro and in vivo. Simultaneously, intravenous transfer of apoptotic T cell-induced tolerogenic dendritic cells can block development of experimental autoimmune encephalomyelitis (EAE), an inflammatory disease of the central nervous system in C57 BL/6J mouse. Our results imply that it is effector memory CD4(+) T cells, not central memory CD4(+) T cells, which play a major role in chronic inflammatory responses in mice with EAE. Intravenous transfer of tolerogenic dendritic cells induced by apoptotic T cells leads to immune tolerance by specifically blocking development of CD4(+) effector memory T cells compared with results of EAE control mice. These results reveal a new mechanism of apoptotic cell-treated dendritic cell-mediated immune tolerance in vivo.

  1. Metallothionein treatment reduces proinflammatory cytokines IL-6 and TNF-alpha and apoptotic cell death during experimental autoimmune encephalomyelitis (EAE).

    Science.gov (United States)

    Penkowa, M; Hidalgo, J

    2001-07-01

    Experimental autoimmune encephalomyelitis (EAE) is an animal model for the human autoimmune disease multiple sclerosis (MS). Proinflammatory cytokines such as interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) are considered important for induction and pathogenesis of EAE/MS disease, which is characterized by significant inflammation and neuroglial damage. We have recently shown that the exogenous administration of the antioxidant protein zinc-metallothionein-II (Zn-MT-II) significantly decreased the clinical symptoms, mortality, and leukocyte infiltration of the CNS during EAE. However, it is not known how EAE progression is regulated nor how cytokine production and cell death can be reduced. We herewith demonstrate that treatment with Zn-MT-II significantly decreased the CNS expression of IL-6 and TNF-alpha during EAE. Zn-MT-II treatment could also significantly reduce apoptotic cell death of neurons and oligodendrocytes during EAE, as judged by using TUNEL and immunoreactivity for cytochrome c and caspases 1 and 3. In contrast, the number of apoptotic lymphocytes and macrophages was less affected by Zn-MT-II treatment. The Zn-MT-II-induced decrease in proinflammatory cytokines and apoptosis during EAE could contribute to the reported diminution of clinical symptoms and mortality in EAE-immunized rats receiving Zn-MT-II treatment. Our results demonstrate that MT-II reduces the CNS expression of proinflammatory cytokines and the number of apoptotic neurons during EAE in vivo and that MT-II might be a potentially useful factor for treatment of EAE/MS.

  2. Pro-apoptotic activity of α-bisabolol in preclinical models of primary human acute leukemia cells

    Directory of Open Access Journals (Sweden)

    Fato Romana

    2011-04-01

    Full Text Available Abstract Background We previously demonstrated that the plant-derived agent α-bisabolol enters cells via lipid rafts, binds to the pro-apoptotic Bcl-2 family protein BID, and may induce apoptosis. Here we studied the activity of α-bisabolol in acute leukemia cells. Methods We tested ex vivo blasts from 42 acute leukemias (14 Philadelphia-negative and 14 Philadelphia-positive B acute lymphoid leukemias, Ph-/Ph+B-ALL; 14 acute myeloid leukemias, AML for their sensitivity to α-bisabolol in 24-hour dose-response assays. Concentrations and time were chosen based on CD34+, CD33+my and normal peripheral blood cell sensitivity to increasing α-bisabolol concentrations for up to 120 hours. Results A clustering analysis of the sensitivity over 24 hours identified three clusters. Cluster 1 (14 ± 5 μM α-bisabolol IC50 included mainly Ph-B-ALL cells. AML cells were split into cluster 2 and 3 (45 ± 7 and 65 ± 5 μM IC50. Ph+B-ALL cells were scattered, but mainly grouped into cluster 2. All leukemias, including 3 imatinib-resistant cases, were eventually responsive, but a subset of B-ALL cells was fairly sensitive to low α-bisabolol concentrations. α-bisabolol acted as a pro-apoptotic agent via a direct damage to mitochondrial integrity, which was responsible for the decrease in NADH-supported state 3 respiration and the disruption of the mitochondrial membrane potential. Conclusion Our study provides the first evidence that α-bisabolol is a pro-apoptotic agent for primary human acute leukemia cells.

  3. Sequence and expression variations in 23 genes involved in mitochondrial and non-mitochondrial apoptotic pathways and risk of oral leukoplakia and cancer.

    Science.gov (United States)

    Datta, Sayantan; Ray, Anindita; Singh, Richa; Mondal, Pinaki; Basu, Analabha; De Sarkar, Navonil; Majumder, Mousumi; Maiti, Guruparasad; Baral, Aradhita; Jha, Ganga Nath; Mukhopadhyay, Indranil; Panda, Chinmay; Chowdhury, Shantanu; Ghosh, Saurabh; Roychoudhury, Susanta; Roy, Bidyut

    2015-11-01

    Oral cancer is usually preceded by pre-cancerous lesion and related to tobacco abuse. Tobacco carcinogens damage DNA and cells harboring such damaged DNA normally undergo apoptotic death, but cancer cells are exceptionally resistant to apoptosis. Here we studied association between sequence and expression variations in apoptotic pathway genes and risk of oral cancer and precancer. Ninety nine tag SNPs in 23 genes, involved in mitochondrial and non-mitochondrial apoptotic pathways, were genotyped in 525 cancer and 253 leukoplakia patients and 538 healthy controls using Illumina Golden Gate assay. Six SNPs (rs1473418 at BCL2; rs1950252 at BCL2L2; rs8190315 at BID; rs511044 at CASP1; rs2227310 at CASP7 and rs13010627 at CASP10) significantly modified risk of oral cancer but SNPs only at BCL2, CASP1and CASP10 modulated risk of leukoplakia. Combination of SNPs showed a steep increase in risk of cancer with increase in "effective" number of risk alleles. In silico analysis of published data set and our unpublished RNAseq data suggest that change in expression of BID and CASP7 may have affected risk of cancer. In conclusion, three SNPs, rs1473418 in BCL2, rs1950252 in BCL2L2 and rs511044 in CASP1, are being implicated for the first time in oral cancer. Since SNPs at BCL2, CASP1 and CASP10 modulated risk of both leukoplakia and cancer, so, they should be studied in more details for possible biomarkers in transition of leukoplakia to cancer. This study also implies importance of mitochondrial apoptotic pathway gene (such as BCL2) in progression of leukoplakia to oral cancer.

  4. The CORM ALF-186 Mediates Anti-Apoptotic Signaling via an Activation of the p38 MAPK after Ischemia and Reperfusion Injury in Retinal Ganglion Cells

    Science.gov (United States)

    Ulbrich, Felix; Kaufmann, Kai B.; Meske, Alexander; Lagrèze, Wolf A.; Augustynik, Michael; Buerkle, Hartmut; Ramao, Carlos C.; Biermann, Julia

    2016-01-01

    Purpose Ischemia and reperfusion injury may induce apoptosis and lead to sustained tissue damage and loss of function, especially in neuronal organs. While carbon monoxide is known to exert protective effects after various harmful events, the mechanism of carbon monoxide releasing molecules in neuronal tissue has not been investigated yet. We hypothesize that the carbon monoxide releasing molecule (CORM) ALF-186, administered after neuronal ischemia-reperfusion injury (IRI), counteracts retinal apoptosis and its involved signaling pathways and consecutively reduces neuronal tissue damage. Methods IRI was performed in rat´s retinae for 1 hour. The water-soluble CORM ALF-186 (10 mg/kg) was administered intravenously via a tail vein after reperfusion. After 24 and 48 hours, retinal tissue was harvested to analyze mRNA and protein expression of Bcl-2, Bax, Caspase-3, ERK1/2, p38 and JNK. Densities of fluorogold pre-labeled retinal ganglion cells (RGC) were analyzed 7 days after IRI. Immunohistochemistry was performed on retinal cross sections. Results ALF-186 significantly reduced IRI mediated loss of RGC. ALF-186 treatment differentially affected mitogen-activated protein kinases (MAPK) phosphorylation: ALF-186 activated p38 and suppressed ERK1/2 phosphorylation, while JNK remained unchanged. Furthermore, ALF-186 treatment affected mitochondrial apoptosis, decreasing pro-apoptotic Bax and Caspase-3-cleavage, but increasing anti-apoptotic Bcl-2. Inhibition of p38-MAPK using SB203580 reduced ALF-186 mediated anti-apoptotic effects. Conclusion In this study, ALF-186 mediated substantial neuroprotection, affecting intracellular apoptotic signaling, mainly via MAPK p38. CORMs may thus represent a promising therapeutic alternative treating neuronal IRI. PMID:27764224

  5. Role of permissive hypotension, hypertonic resuscitation and the global increased permeability syndrome in patients with severe hemorrhage: adjuncts to damage control resuscitation to prevent intra-abdominal hypertension.

    Science.gov (United States)

    Duchesne, Juan C; Kaplan, Lewis J; Balogh, Zsolt J; Malbrain, Manu L N G

    2015-01-01

    Secondary intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) are closely related to fluid resuscitation. IAH causes major deterioration of the cardiac function by affecting preload, contractility and afterload. The aim of this review is to discuss the different interactions between IAH, ACS and resuscitation, and to explore a new hypothesis with regard to damage control resuscitation, permissive hypotension and global increased permeability syndrome. Review of the relevant literature via PubMed search. The recognition of the association between the development of ACS and resuscitation urged the need for new approach in traumatic shock management. Over a decade after wide spread application of damage control surgery damage control resuscitation was developed. DCR differs from previous resuscitation approaches by attempting an earlier and more aggressive correction of coagulopathy, as well as metabolic derangements like acidosis and hypothermia, often referred to as the 'deadly triad' or the 'bloody vicious cycle'. Permissive hypotension involves keeping the blood pressure low enough to avoid exacerbating uncontrolled haemorrhage while maintaining perfusion to vital end organs. The potential detrimental mechanisms of early, aggressive crystalloid resuscitation have been described. Limitation of fluid intake by using colloids, hypertonic saline (HTS) or hyperoncotic albumin solutions have been associated with favourable effects. HTS allows not only for rapid restoration of circulating intravascular volume with less administered fluid, but also attenuates post-injury oedema at the microcirculatory level and may improve microvascular perfusion. Capillary leak represents the maladaptive, often excessive, and undesirable loss of fluid and electrolytes with or without protein into the interstitium that generates oedema. The global increased permeability syndrome (GIPS) has been articulated in patients with persistent systemic inflammation failing

  6. DNA-membrane complex damages in mammalian cells after gamma irradiation and chemical agent action and role of the complex in DNA replication

    Energy Technology Data Exchange (ETDEWEB)

    Saenko, A.S.; Kiseleva, V.I.; Synzynys, B.I. (Akademiya Meditsinskikh Nauk SSSR, Obninsk. Nauchno-Issledovatel' skij Inst. Meditsinskoj Radiologii)

    1982-06-22

    The sedimentation behavior of the DNA-membrane complex (DMC) from Ehrlich ascites tumor (EAT) cells after gamma irradiation and carminomycin (CM) treatment was studied. The DNA and membrane containing material released by alkaline lysis from EAT cells had an anomalous sedimentation relative to denatured DNA. The DMC sediments with a great sedimentation constant (255 S). Both the chemical and physical agents induced DNA single-strand breaks and damage of the DMC. It was shown that 0.01 g/ml CM did not affect the incorporation of exogenic thymidine into DNA but the DMC was completely disrupted by this CM dose. There was no correlation between postirradiation repair kinetics of the DMC and the kinetics of /sup 3/H-thymidine incorporation into DNA of ETA cells.

  7. Hyperoxia-induced ciliary loss and oxidative damage in an in vitro bovine model: The protective role of antioxidant vitamins E and C

    Energy Technology Data Exchange (ETDEWEB)

    Al-Shmgani, Hanady S.; Moate, Roy M. [School of Biomedical and Biological Sciences, University of Plymouth (United Kingdom); Sneyd, J. Robert [Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth (United Kingdom); Macnaughton, Peter D. [Derriford Critical Care Unit, Plymouth (United Kingdom); Moody, A. John, E-mail: jmoody@plymouth.ac.uk [School of Biomedical and Biological Sciences, University of Plymouth (United Kingdom)

    2012-12-14

    Highlights: Black-Right-Pointing-Pointer A new bovine bronchial model for studying hyperoxia-induced cilia loss is presented. Black-Right-Pointing-Pointer Hyperoxia-induced cilia loss was associated with increased sloughing of cells. Black-Right-Pointing-Pointer Hyperoxia led to higher epithelial glutathione levels, evidence of oxidative stress. Black-Right-Pointing-Pointer Hyperoxia led to increased DNA damage (Comet), and lipid peroxidation (TBARS). Black-Right-Pointing-Pointer Vitamins C and E partially protected against hyperoxia-induced cilia loss. -- Abstract: Although elevated oxygen fraction is used in intensive care units around the world, pathological changes in pulmonary tissue have been shown to occur with prolonged exposure to hyperoxia. In this work a bovine bronchus culture model has been successfully used to evaluate the effects of hyperoxia on ciliated epithelium in vitro. Samples were cultured using an air interface method and exposed to normoxia, 21% O{sub 2} or hyperoxia, 95% O{sub 2}. Cilial coverage was assessed using scanning electron microscopy (SEM). Tissue damage (lactate dehydrogenase, LDH, in the medium), lipid peroxidation (thiobarbituric acid reactive substances, TBARS), DNA damage (comet assay), protein oxidation (OxyBlot kit) and antioxidant status (total glutathione) were used to assess whether the hyperoxia caused significant oxidative stress. Hyperoxia caused a time-dependent decline (t{sub Vulgar-Fraction-One-Half} = 3.4 d compared to 37.1 d under normoxia) in cilial coverage (P < 0.0001). This was associated with a significant increase in the number of cells (2.80 {+-} 0.27 Multiplication-Sign 10{sup 6} compared to 1.97 {+-} 0.23 Multiplication-Sign 10{sup 6} ml{sup -1} after 6 d), many apparently intact, in the medium (P < 0.05); LDH release (1.06 {+-} 0.29 compared to 0.83 {+-} 0.36 {mu}mol min{sup -1} g{sup -1} after 6 d; P < 0.001); lipid peroxidation (352 {+-} 16 versus 247 {+-} 11 {mu}mol MDA g{sup -1} for hyperoxia and

  8. Chronic emotional stress exposure increases infarct size in rats: the role of oxidative and nitrosative damage in response to sympathetic hyperactivity.

    Science.gov (United States)

    Mercanoglu, G; Safran, N; Uzun, H; Eroglu, L

    2008-12-01

    We investigated the level of sympathetic hyperactivity in response to stress exposure in an acute myocardial infarction (AMI) model and the contribution of oxidative and nitrosative damage to this phenomenon. Stress was induced by 20-day administration of different emotional stress factors: daylight/darkness exposure, overcrowding, isolation, new hierarchy, tilting the cage and restriction of water or food. AMI was induced surgically. Heart rate (HR) and heart rate variability (HRV) measurements were done before and after AMI. Oxidant parameters were measured in heart tissue and cortisol levels were measured in plasma specimens. Compared with the nonstressed group, stress-exposed rats showed sympathetic hyperactivity characterized by increased HR together with decreased HRV. In the stressed group serum corticosterone levels were high both before and after AMI. Mean infarct size in the stressed group was significantly larger (44.6+/-3.23% and 53.1+/-4.52%, respectively; P<0.05). Increased tissue malondialdehyde (MDA) levels (0.63+/-0.59 and 1.60+/-0.31 nmol/mg protein, respectively; P<0.05) and decreased superoxide dismutase (SOD) activity and glutathione (GSH) content were seen in stress-exposed rats. Likewise, heart peroxynitrite levels were also high in stress-exposed rats (141.8+/-18 nmol/g tissue vs. 164.2+/-21 nmol/g tissue). Chronic emotional stress is a deteriorating factor for the induction and prognosis of MI. Exaggerated sympathetic activity may be the major contributing factor. Oxidative and nitrosative damage in response to this sympathetic hyperactivity is the key mechanism.

  9. Role of protein synthesis in the repair of sublethal x-ray damage in a mutant Chinese hamster ovary cell line

    Energy Technology Data Exchange (ETDEWEB)

    Yezzi, M.J.

    1985-04-01

    A temperature-sensitive mutant for protein synthesis, CHO-TSH1, has been compared to the wild-type cell, CHO-sC1, in single- and split-radiation-dose schemes. When the exponentially growing TS mutant and the wild-type cells were treated at 40/sub 0/C for up to 2 hrs prior to graded doses of x rays, the survival curves were identical and were the same as those obtained without heat treatment. If the cultures were incubated at 40/sup 0/C for 2 hrs before a first dose and maintained at 40/sup 0/C during a 2 hr dose fractionation interval, repair of radiation damage was reduced in the mutant compared to the wild type. These observations implied that a pool of proteins was involved in the repair of sublethal x-ray damage. However, if repair was measured by the alkaline-unwinding technique under the same time and temperature schemes, no difference in the kientics of DNA strand rejoining was observed. Misrepair processes may permit restoration of DNA strand integrity but not allow functional repair. The effect of diminished repair under conditions of inhibition of protein synthesis was found to be cell-cycle dependent in survival studies with synchronized mutant cell populations. Repair was found to be almost completely eliminated if the temperature sequence described above was applied in the middle of the DNA synthetic phase. Treatment of cell populations in the middle of G/sub 1/-phase yielded repair inhibition comparable to that observed with the asynchronous cells. Splitdose experiments were done using pre-incubation with cycloheximide to chemically inhibit protein synthesis. WT cells and TS cells were treated with cycloheximide at 35/sup 0/C for 2 hrs before a first dose and during a 2 hr dose fractionation interval. 23 figs., 7 tabs.

  10. Tula hantavirus triggers pro-apoptotic signals of ER stress in Vero E6 cells.

    Science.gov (United States)

    Li, Xiao-Dong; Lankinen, Hilkka; Putkuri, Niina; Vapalahti, Olli; Vaheri, Antti

    2005-03-01

    Tula virus is a member of the Hantavirus genus of the family Bunyaviridae. Viruses of this family have an unusual pattern of intracellular maturation at the ER-Golgi compartment. We recently found that Tula virus, similar to several other hantaviruses, is able to induce apoptosis in cultured cells [Li, X.D., Kukkonen, S., Vapalahti, O., Plyusnin, A., Lankinen, H., Vaheri, A., 2004. Tula hantavirus infection of Vero E6 cells induces apoptosis involving caspase 8 activation. J. Gen. Virol. 85, 3261-3268.]. However, the cellular mechanisms remain to be clarified. In this study, we demonstrate that the progressive replication of Tula virus in Vero E6 cells initiates several death programs that are intimately associated with ER stress: (1) early activation of ER-resident caspase-12; (2) phosphorylation of Jun NH2-terminal kinase (JNK) and its downstream target transcriptional factor, c-jun; (3) induction of the pro-apoptotic transcriptional factor, growth arrest- and DNA damage-inducible gene 153, or C/EBP homologous protein (Gadd153/chop); and (4) changes in the ER-membrane protein BAP31 implying cross-talk with the mitochondrial apoptosis pathway. Furthermore, we confirmed that a