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Sample records for arsenite induces apoptosis

  1. Mitotic arrest-associated apoptosis induced by sodium arsenite in A375 melanoma cells is BUBR1-dependent

    SciTech Connect

    McNeely, Samuel C.; Taylor, B. Frazier; States, J. Christopher

    2008-08-15

    A375 human malignant melanoma cells undergo mitotic arrest-associated apoptosis when treated with pharmacological concentrations of sodium arsenite, a chemotherapeutic for acute promyelocytic leukemia. Our previous studies indicated that decreased arsenite sensitivity correlated with reduced mitotic spindle checkpoint function and reduced expression of the checkpoint protein BUBR1. In the current study, arsenite induced securin and cyclin B stabilization, BUBR1 phosphorylation, and spindle checkpoint activation. Arsenite also increased activating cyclin dependent kinase 1 (CDK1) Thr{sup 161} phosphorylation but decreased inhibitory Tyr15 phosphorylation. Mitotic arrest resulted in apoptosis as indicated by colocalization of mitotic phospho-Histone H3 with active caspase 3. Apoptosis was associated with BCL-2 Ser70 phosphorylation. Inhibition of CDK1 with roscovitine in arsenite-treated mitotic cells inhibited spindle checkpoint maintenance as inferred from reduced BUBR1 phosphorylation, reduced cyclin B expression, and diminution of mitotic index. Roscovitine also reduced BCL-2 Ser70 phosphorylation and protected against apoptosis, suggesting mitotic arrest caused by hyperactivation of CDK1 directly or indirectly leads to BCL-2 phosphorylation and apoptosis. In addition, suppression of BUBR1 with siRNA prevented arsenite-induced mitotic arrest and apoptosis. These findings provide insight into the mechanism of arsenic's chemotherapeutic action and indicate a functional spindle checkpoint may be required for arsenic-sensitivity.

  2. Arsenite induces apoptosis in human mesenchymal stem cells by altering Bcl-2 family proteins and by activating intrinsic pathway

    SciTech Connect

    Yadav, Santosh; Shi Yongli; Wang Feng; Wang He

    2010-05-01

    Purpose: Environmental exposure to arsenic is an important public health issue. The effects of arsenic on different tissues and organs have been intensively studied. However, the effects of arsenic on bone marrow mesenchymal stem cells (MSCs) have not been reported. This study is designed to investigate the cell death process caused by arsenite and its related underlying mechanisms on MSCs. The rationale is that absorbed arsenic in the blood circulation can reach to the bone marrow and may affect the cell survival of MSCs. Methods: MSCs of passage 1 were purchased from Tulane University, grown till 70% confluency level and plated according to the experimental requirements followed by treatment with arsenite at various concentrations and time points. Arsenite (iAs{sup III}) induced cytotoxic effects were confirmed by cell viability and cell cycle analysis. For the presence of canonic apoptosis markers; DNA damage, exposure of intramembrane phosphotidylserine, protein and m-RNA expression levels were analyzed. Results: iAs{sup III} induced growth inhibition, G2-M arrest and apoptotic cell death in MSCs, the apoptosis induced by iAs{sup III} in the cultured MSCs was, via altering Bcl-2 family proteins and by involving intrinsic pathway. Conclusion: iAs{sup III} can induce apoptosis in bone marrow-derived MSCs via Bcl-2 family proteins, regulating intrinsic apoptotic pathway. Due to the multipotency of MSC, acting as progenitor cells for a variety of connective tissues including bone, adipose, cartilage and muscle, these effects of arsenic may be important in assessing the health risk of the arsenic compounds and understanding the mechanisms of arsenic-induced harmful effects.

  3. Endoplasmic reticulum stress is involved in arsenite-induced oxidative injury in rat brain

    SciTech Connect

    Lin, Anya M.Y.; Chao, P.L.; Fang, S.F.; Chi, C.W.; Yang, C.H.

    2007-10-15

    The mechanism underlying sodium arsenite (arsenite)-induced neurotoxicity was investigated in rat brain. Arsenite was locally infused in the substantia nigra (SN) of anesthetized rat. Seven days after infusion, lipid peroxidation in the infused SN was elevated and dopamine level in the ipsilateral striatum was reduced in a concentration-dependent manner (0.3-5 nmol). Furthermore, local infusion of arsenite (5 nmol) decreased GSH content and increased expression of heat shock protein 70 and heme oxygenase-1 in the infused SN. Aggregation of {alpha}-synuclein, a putative pathological protein involved in several CNS neurodegenerative diseases, was elevated in the arsenite-infused SN. From the breakdown pattern of {alpha}-spectrin, both necrosis and apoptosis were involved in the arsenite-induced neurotoxicity. Pyknotic nuclei, cellular shrinkage and cytoplasmic disintegration, indicating necrosis, and TUNEL-positive cells and DNA ladder, indicating apoptosis was observed in the arsenite-infused SN. Arsenite-induced apoptosis was mediated via two different organelle pathways, mitochondria and endoplasmic reticulum (ER). For mitochondrial activation, cytosolic cytochrome c and caspase-3 levels were elevated in the arsenite-infused SN. In ER pathway, arsenite increased activating transcription factor-4, X-box binding protein 1, C/EBP homologues protein (CHOP) and cytosolic immunoglobulin binding protein levels. Moreover, arsenite reduced procaspase 12 levels, an ER-specific enzyme in the infused SN. Taken together, our study suggests that arsenite is capable of inducing oxidative injury in CNS. In addition to mitochondria, ER stress was involved in the arsenite-induced apoptosis. Arsenite-induced neurotoxicity clinically implies a pathophysiological role of arsenite in CNS neurodegeneration.

  4. Sensitivity to sodium arsenite in human melanoma cells depends upon susceptibility to arsenite-induced mitotic arrest

    SciTech Connect

    McNeely, Samuel C.; Belshoff, Alex C.; Taylor, B. Frazier; Fan, Teresa W-M.; McCabe, Michael J.; Pinhas, Allan R.

    2008-06-01

    Arsenic induces clinical remission in patients with acute promyelocytic leukemia and has potential for treatment of other cancers. The current study examines factors influencing sensitivity to arsenic using human malignant melanoma cell lines. A375 and SK-Mel-2 cells were sensitive to clinically achievable concentrations of arsenite, whereas SK-Mel-3 and SK-Mel-28 cells required supratherapeutic levels for toxicity. Inhibition of glutathione synthesis, glutathione S-transferase (GST) activity, and multidrug resistance protein (MRP) transporter function attenuated arsenite resistance, consistent with studies suggesting that arsenite is extruded from the cell as a glutathione conjugate by MRP-1. However, MRP-1 was not overexpressed in resistant lines and GST-{pi} was only slightly elevated. ICP-MS analysis indicated that arsenite-resistant SK-Mel-28 cells did not accumulate less arsenic than arsenite-sensitive A375 cells, suggesting that resistance was not attributable to reduced arsenic accumulation but rather to intrinsic properties of resistant cell lines. The mode of arsenite-induced cell death was apoptosis. Arsenite-induced apoptosis is associated with cell cycle alterations. Cell cycle analysis revealed arsenite-sensitive cells arrested in mitosis whereas arsenite-resistant cells did not, suggesting that induction of mitotic arrest occurs at lower intracellular arsenic concentrations. Higher intracellular arsenic levels induced cell cycle arrest in the S-phase and G{sub 2}-phase in SK-Mel-3 and SK-Mel-28 cells, respectively. The lack of arsenite-induced mitotic arrest in resistant cell lines was associated with a weakened spindle checkpoint resulting from reduced expression of spindle checkpoint protein BUBR1. These data suggest that arsenite has potential for treatment of solid tumors but a functional spindle checkpoint is a prerequisite for a positive response to its clinical application.

  5. The effect of arsenite on spatial learning: Involvement of autophagy and apoptosis.

    PubMed

    BonakdarYazdi, Behnoosh; Khodagholi, Fariba; Shaerzadeh, Fatemeh; Sharifzadeh, Azadeh; Ahmadi, Ramesh; Sanati, Mehdi; Mehdizadeh, Hajar; Payandehmehr, Borna; Vali, Leila; Jahromi, Mehrnoush Moghaddasi; Taghizadeh, Ghorban; Sharifzadeh, Mohammad

    2017-02-05

    Spatial learning plays a major role in one's information recording. Arsenic is one of ubiquitous environmental toxins with known neurological effects. However, studies investigating the effects of arsenic on spatial learning and related mechanisms are limited. This study was planned toexaminethe effects of bilateral intra-hippocampal infusion of different concentrations of sodium arsenite (5, 10 and 100nM, 5µl/side) on spatial learning in Wistar rats. Moreover, we evaluated levels of LC3-II, Atg7 and Atg12 as reliable biomarkers of autophagy and caspase-3 and Bax/Bcl-2 ratio as indicators of apoptosis in the hippocampus. Interestingly, low concentrations of sodium arsenite (5 and 10nM) significantly increased spatial acquisition but pre-training administration of sodium arsenite100nM did not significantly alter spatial learning. LC3-II levels were significantly increased in groups treated with sodium arsenite 5 and 10nM and decreased in the group receiving arsenite 100nM compared to the control group. Atg7 and Atg12 levels were obviously higher in all groups treated with sodium arsenite compared to control. However, caspase-3 cleavage and Bax/Bcl-2 ratio were notably greater in 100nM, and lesser in 5nM arsenite group in comparison with control animals. The results of this study showed that the low concentrations of sodium arsenite could facilitate spatial learning. This facilitation could be attributed to neuronal autophagy induced by low concentrations of sodium arsenite. These findings may help to clarify the regulatory pathways for apoptosis and autophagy balance due to sodium arsenite.

  6. Autophagy is the predominant process induced by arsenite in human lymphoblastoid cell lines

    SciTech Connect

    Bolt, Alicia M.; Byrd, Randi M.; Klimecki, Walter T.

    2010-05-01

    Arsenic is a widespread environmental toxicant with a diverse array of molecular targets and associated diseases, making the identification of the critical mechanisms and pathways of arsenic-induced cytotoxicity a challenge. In a variety of experimental models, over a range of arsenic exposure levels, apoptosis is a commonly identified arsenic-induced cytotoxic pathway. Human lymphoblastoid cell lines (LCL) have been used as a model system in arsenic toxicology for many years, but the exact mechanism of arsenic-induced cytotoxicity in LCL is still unknown. We investigated the cytotoxicity of sodium arsenite in LCL 18564 using a set of complementary markers for cell death pathways. Markers indicative of apoptosis (phosphatidylserine externalization, PARP cleavage, and sensitivity to caspase inhibition) were uniformly negative in arsenite exposed cells. Interestingly, electron microscopy, acidic vesicle fluorescence, and expression of LC3 in LCL 18564 identified autophagy as an arsenite-induced process that was associated with cytotoxicity. Autophagy, a cellular programmed response that is associated with both cellular stress adaptation as well as cell death appears to be the predominant process in LCL cytotoxicity induced by arsenite. It is unclear, however, whether LCL autophagy is an effector mechanism of arsenite cytotoxicity or alternatively a cellular compensatory mechanism. The ability of arsenite to induce autophagy in lymphoblastoid cell lines introduces a potentially novel mechanistic explanation of the well-characterized in vitro and in vivo toxicity of arsenic to lymphoid cells.

  7. Sodium arsenite down-regulates the expression of X-linked inhibitor of apoptosis protein via translational and post-translational mechanisms in hepatocellular carcinoma

    SciTech Connect

    Chen, Hong; Hao, Yuqing; Wang, Lijing; Jia, Dongwei; Ruan, Yuanyuan; Gu, Jianxin

    2012-06-15

    Highlights: Black-Right-Pointing-Pointer Sodium arsenite down-regulates the protein expression level of XIAP in HCC. Black-Right-Pointing-Pointer Sodium arsenite inhibits the de novo XIAP synthesis and its IRES activity. Black-Right-Pointing-Pointer Sodium arsenite decreases XIAP stability and promotes its proteasomal degradation. Black-Right-Pointing-Pointer Overexpression of XIAP attenuates the pro-apoptotic effect of sodium arsenite. -- Abstract: X-linked inhibitor of apoptosis protein (XIAP) is a member of the inhibitors of apoptosis protein (IAP) family, and has been reported to exhibit elevated expression levels in hepatocellular carcinoma (HCC) and promote cell survival, metastasis and tumor recurrence. Targeting XIAP has proven effective for the inhibition of cancer cell proliferation and restoration of cancer cell chemosensitivity. Arsenic (or sodium arsenite) is a potent anti-tumor agent used to treat patients with acute promyelocytic leukemia (APL). Additionally, arsenic induces cell growth inhibition, cell cycle arrest and apoptosis in human HCC cells. In this study, we identified XIAP as a target for sodium arsenite-induced cytotoxicity in HCC. The exposure of HCC cell lines to sodium arsenite resulted in inhibition of XIAP expression in both a dose- and time-dependent manner. Sodium arsenite blocked the de novo XIAP synthesis and the activity of its internal ribosome entry site (IRES) element. Moreover, treatment with sodium arsenite decreased the protein stability of XIAP and induced its ubiquitin-proteasomal degradation. Overexpression of XIAP attenuated the pro-apoptotic effect of sodium arsenite in HCC. Taken together, our data demonstrate that sodium arsenite suppresses XIAP expression via translational and post-translational mechanisms in HCC.

  8. Sodium arsenite accelerates TRAIL-mediated apoptosis in melanoma cells through upregulation of TRAIL-R1/R2 surface levels and downregulation of cFLIP expression

    SciTech Connect

    Ivanov, Vladimir N. . E-mail: vni3@columbia.edu; Hei, Tom K.

    2006-12-10

    AP-1/cJun, NF-{kappa}B and STAT3 transcription factors control expression of numerous genes, which regulate critical cell functions including proliferation, survival and apoptosis. Sodium arsenite is known to suppress both the IKK-NF-{kappa}B and JAK2-STAT3 signaling pathways and to activate the MAPK/JNK-cJun pathways, thereby committing some cancers to undergo apoptosis. Indeed, sodium arsenite is an effective drug for the treatment of acute promyelocytic leukemia with little nonspecific toxicity. Malignant melanoma is highly refractory to conventional radio- and chemotherapy. In the present study, we observed strong effects of sodium arsenite treatment on upregulation of TRAIL-mediated apoptosis in human and mouse melanomas. Arsenite treatment upregulated surface levels of death receptors, TRAIL-R1 and TRAIL-R2, through increased translocation of these proteins from cytoplasm to the cell surface. Furthermore, activation of cJun and suppression of NF-{kappa}B by sodium arsenite resulted in upregulation of the endogenous TRAIL and downregulation of the cFLIP gene expression (which encodes one of the main anti-apoptotic proteins in melanomas) followed by cFLIP protein degradation and, finally, by acceleration of TRAIL-induced apoptosis. Direct suppression of cFLIP expression by cFLIP RNAi also accelerated TRAIL-induced apoptosis in these melanomas, while COX-2 suppression substantially increased levels of both TRAIL-induced and arsenite-induced apoptosis. In contrast, overexpression of permanently active AKTmyr inhibited TRAIL-mediated apoptosis via downregulation of TRAIL-R1 levels. Finally, AKT overactivation increased melanoma survival in cell culture and dramatically accelerated growth of melanoma transplant in vivo, highlighting a role of AKT suppression for effective anticancer treatment.

  9. Arsenite promotes centrosome abnormalities under a p53 compromised status induced by 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)

    SciTech Connect

    Liao, W.-T.; Yu, H.-S.; Lin Pinpin; Chang, Louis W.

    2010-02-15

    Epidemiological evidence indicated that residents, especially cigarette smokers, in arseniasis areas had significantly higher lung cancer risk than those living in non-arseniasis areas. Thus an interaction between arsenite and cigarette smoking in lung carcinogenesis was suspected. In the present study, we investigated the interactions of a tobacco-specific carcinogen 4- (methylnitrosamino)-1-(3-pyridyl)-1-butanone (nicotine-derived nitrosamine ketone, NNK) and arsenite on lung cell transformation. BEAS-2B, an immortalized human lung epithelial cell line, was selected to test the centrosomal abnormalities and colony formation by NNK and arsenite. We found that NNK, alone, could enhance BEAS-2B cell growth at 1-5 muM. Under NNK exposure, arsenite was able to increase centrosomal abnormality as compared with NNK or arsenite treatment alone. NNK treatment could also reduce arsenite-induced G2/M cell cycle arrest and apoptosis, these cellular effects were found to be correlated with p53 dysfunction. Increased anchorage-independent growth (colony formation) of BEAS-2B cells cotreated with NNK and arsenite was also observed in soft agar. Our present investigation demonstrated that NNK could provide a p53 compromised status. Arsenite would act specifically on this p53 compromised status to induce centrosomal abnormality and colony formation. These findings provided strong evidence on the carcinogenic promotional role of arsenite under tobacco-specific carcinogen co-exposure.

  10. Suppression of p53 and p21CIP1/WAF1 reduces arsenite-induced aneuploidy

    PubMed Central

    Salazar, Ana María; Miller, Heather L.; McNeely, Samuel C.; Sordo, Monserrat; Ostrosky-Wegman, Patricia; States, J. Christopher

    2009-01-01

    Aneuploidy and extensive chromosomal rearrangements are common in human tumors. The role of DNA damage response proteins p53 and p21CIP1/WAF1 in aneugenesis and clastogenesis was investigated in telomerase immortalized diploid human fibroblasts using siRNA suppression of p53 and p21CIP1/WAF1. Cells were exposed to the environmental carcinogen sodium arsenite (15 and 20 µM), and the induction of micronuclei (MN) was evaluated in binucleated cells using the cytokinesis-block assay. To determine whether MN resulted from missegregation of chromosomes or from chromosomal fragments, we used a fluorescent in situ hybridization with a centromeric DNA probe. Micronuclei were predominantly of clastogenic origin in control cells regardless of p53 or p21CIP1/WAF1 expression. MN with centromere signals in cells transfected with NSC siRNA or Mock increased 30% after arsenite exposure, indicating that arsenite induced aneuploidy in the tGM24 cells. Although suppression of p53 increased the fraction of arsenite-treated cells with MN, it caused a decrease in the fraction of with centeromeric DNA. Suppression of p21CIP1/WAF1 like p53 suppression decreased the fraction of with centromeric DNA. Our results suggest that cells lacking normal p53 function cannot become aneuploid because they die by mitotic arrest-associated apoptosis, whereas cells with normal p53 function that are able to exit from mitotic arrest can become aneuploid. Furthermore our current results support this role for p21CIP1/WAF1. Since suppression of p21CIP1/WAF1 caused a decrease in aneuploidy induced by arsenite suggesting that p21CIP1/WAF1 plays a role in mitotic exit. PMID:20000476

  11. Involvement of HIF-2α-mediated inflammation in arsenite-induced transformation of human bronchial epithelial cells

    SciTech Connect

    Xu, Yuan; Zhao, Yue; Xu, Wenchao; Luo, Fei; Wang, Bairu; Li, Yuan; Pang, Ying; Liu, Qizhan

    2013-10-15

    Arsenic is a well established human carcinogen that causes diseases of the lung. Some studies have suggested a link between inflammation and lung cancer; however, it is unknown if arsenite-induced inflammation causally contributes to arsenite-caused malignant transformation of cells. In this study, we investigated the molecular mechanisms underlying inflammation during neoplastic transformation induced in human bronchial epithelial (HBE) cells by chronic exposure to arsenite. The results showed that, on acute or chronic exposure to arsenite, HBE cells over-expressed the pro-inflammatory cytokines, interleukin-6 (IL-6), interleukin-8 (IL-8), and interleukin-1β (IL-1β). The data also indicated that HIF-2α was involved in arsenite-induced inflammation. Moreover, IL-6 and IL-8 were essential for the malignant progression of arsenite-transformed HBE cells. Thus, these experiments show that HIF-2α mediates arsenite-induced inflammation and that such inflammation is involved in arsenite-induced malignant transformation of HBE cells. The results provide a link between the inflammatory response and the acquisition of a malignant transformed phenotype by cells chronically exposed to arsenite and thus establish a previously unknown mechanism for arsenite-induced carcinogenesis. - Highlights: • Arsenite induces inflammation. • Arsenite-induced the increases of IL-6 and IL-8 via HIF-2α. • Inflammation is involved in arsenite-induced carcinogenesis.

  12. Arsenite-induced mitotic death involves stress response and is independent of tubulin polymerization

    SciTech Connect

    Taylor, B. Frazier; McNeely, Samuel C.; Miller, Heather L.; States, J. Christopher

    2008-07-15

    Arsenite, a known mitotic disruptor, causes cell cycle arrest and cell death at anaphase. The mechanism causing mitotic arrest is highly disputed. We compared arsenite to the spindle poisons nocodazole and paclitaxel. Immunofluorescence analysis of {alpha}-tubulin in interphase cells demonstrated that, while nocodazole and paclitaxel disrupt microtubule polymerization through destabilization and hyperpolymerization, respectively, microtubules in arsenite-treated cells remain comparable to untreated cells even at supra-therapeutic concentrations. Immunofluorescence analysis of {alpha}-tubulin in mitotic cells showed spindle formation in arsenite- and paclitaxel-treated cells but not in nocodazole-treated cells. Spindle formation in arsenite-treated cells appeared irregular and multi-polar. {gamma}-tubulin staining showed that cells treated with nocodazole and therapeutic concentrations of paclitaxel contained two centrosomes. In contrast, most arsenite-treated mitotic cells contained more than two centrosomes, similar to centrosome abnormalities induced by heat shock. Of the three drugs tested, only arsenite treatment increased expression of the inducible isoform of heat shock protein 70 (HSP70i). HSP70 and HSP90 proteins are intimately involved in centrosome regulation and mitotic spindle formation. HSP90 inhibitor 17-DMAG sensitized cells to arsenite treatment and increased arsenite-induced centrosome abnormalities. Combined treatment of 17-DMAG and arsenite resulted in a supra-additive effect on viability, mitotic arrest, and centrosome abnormalities. Thus, arsenite-induced abnormal centrosome amplification and subsequent mitotic arrest is independent of effects on tubulin polymerization and may be due to specific stresses that are protected against by HSP90 and HSP70.

  13. Use of RAPD to detect sodium arsenite-induced DNA damage in human lymphoblastoid cells.

    PubMed

    Lee, Yuan-Cho; Yang, Vivian C; Wang, Tsu-Shing

    2007-09-24

    Inorganic arsenic is a known human carcinogen, yet its mechanism of action remains unclear. Our previous study showed that arsenite significantly induces oxidative DNA adducts and DNA-protein cross-links in several mammalian cell lines. In the present study, we used the random amplified polymorphic DNA (RAPD) assay to evaluate the possible target in the genomic DNA of human lymphoblastoid cells that were exposed to sodium arsenite. Treatment with both 10 and 80 microM arsenite for 4h induced significant changes in RAPD profiles compared with the control pattern. Two 10-mer RAPD primers (D11 and F1) produced the most distinguishable banding profiles between arsenite-treated and control genomic DNA. The sequencing of four arsenite-sensitive RAPD bands showed that the RB1CC1 and PACE4 genes might be the DNA targets of sodium arsenite treatment. We propose that arsenite may induce sequence- or gene-specific damage and then change the RAPD profile in human lymphoblastoid cells. The results of our study also show that RAPD combined with other techniques is a good tool for detecting alterations in genomic DNA and for the direct screening of new molecular markers related to arsenite-induced carcinogenesis.

  14. Reduction of arsenite-enhanced ultraviolet radiation-induced DNA damage by supplemental zinc

    SciTech Connect

    Cooper, Karen L.; King, Brenee S.; Sandoval, Monica M.; Liu, Ke Jian; Hudson, Laurie G.

    2013-06-01

    Arsenic is a recognized human carcinogen and there is evidence that arsenic augments the carcinogenicity of DNA damaging agents such as ultraviolet radiation (UVR) thereby acting as a co-carcinogen. Inhibition of DNA repair is one proposed mechanism to account for the co-carcinogenic actions of arsenic. We and others find that arsenite interferes with the function of certain zinc finger DNA repair proteins. Furthermore, we reported that zinc reverses the effects of arsenite in cultured cells and a DNA repair target protein, poly (ADP-ribose) polymerase-1. In order to determine whether zinc ameliorates the effects of arsenite on UVR-induced DNA damage in human keratinocytes and in an in vivo model, normal human epidermal keratinocytes and SKH-1 hairless mice were exposed to arsenite, zinc or both before solar-simulated (ss) UVR exposure. Poly (ADP-ribose) polymerase activity, DNA damage and mutation frequencies at the Hprt locus were measured in each treatment group in normal human keratinocytes. DNA damage was assessed in vivo by immunohistochemical staining of skin sections isolated from SKH-1 hairless mice. Cell-based findings demonstrate that ssUVR-induced DNA damage and mutagenesis are enhanced by arsenite, and supplemental zinc partially reverses the arsenite effect. In vivo studies confirm that zinc supplementation decreases arsenite-enhanced DNA damage in response to ssUVR exposure. From these data we can conclude that zinc offsets the impact of arsenic on ssUVR-stimulated DNA damage in cells and in vivo suggesting that zinc supplementation may provide a strategy to improve DNA repair capacity in arsenic exposed human populations. - Highlights: • Low levels of arsenite enhance UV-induced DNA damage in human keratinocytes. • UV-initiated HPRT mutation frequency is enhanced by arsenite. • Zinc supplementation offsets DNA damage and mutation frequency enhanced by arsenite. • Zinc-dependent reduction of arsenite enhanced DNA damage is confirmed in vivo.

  15. Low concentration of arsenite exacerbates UVR-induced DNA strand breaks by inhibiting PARP-1 activity

    SciTech Connect

    Qin Xujun; Hudson, Laurie G.; Liu Wenlan; Timmins, Graham S.; Liu Kejian

    2008-10-01

    Epidemiological studies have associated arsenic exposure with many types of human cancers. Arsenic has also been shown to act as a co-carcinogen even at low concentrations. However, the precise mechanism of its co-carcinogenic action is unknown. Recent studies indicate that arsenic can interfere with DNA-repair processes. Poly(ADP-ribose) polymerase (PARP)-1 is a zinc-finger DNA-repair protein, which can promptly sense DNA strand breaks and initiate DNA-repair pathways. In the present study, we tested the hypothesis that low concentrations of arsenic could inhibit PAPR-1 activity and so exacerbate levels of ultraviolet radiation (UVR)-induced DNA strand breaks. HaCat cells were treated with arsenite and/or UVR, and then DNA strand breaks were assessed by comet assay. Low concentrations of arsenite ({<=} 2 {mu}M) alone did not induce significant DNA strand breaks, but greatly enhanced the DNA strand breaks induced by UVR. Further studies showed that 2 {mu}M arsenite effectively inhibited PARP-1 activity. Zinc supplementation of arsenite-treated cells restored PARP-1 activity and significantly diminished the exacerbating effect of arsenite on UVR-induced DNA strand breaks. Importantly, neither arsenite treatment, nor zinc supplementation changed UVR-triggered reactive oxygen species (ROS) formation, suggesting that their effects upon UVR-induced DNA strand breaks are not through a direct free radical mechanism. Combination treatments of arsenite with PARP-1 inhibitor 3-aminobenzamide or PARP-1 siRNA demonstrate that PARP-1 is the target of arsenite. Together, these findings show that arsenite at low concentration exacerbates UVR-induced DNA strand breaks by inhibiting PARP-1 activity, which may represent an important mechanism underlying the co-carcinogenicity of arsenic.

  16. Arsenite-induced autophagy is associated with proteotoxicity in human lymphoblastoid cells

    SciTech Connect

    Bolt, Alicia M.; Zhao, Fei; Pacheco, Samantha; Klimecki, Walter T.

    2012-10-15

    Epidemiological studies of arsenic-exposed populations have provided evidence that arsenic exposure in humans is associated with immunosuppression. Previously, we have reported that arsenite-induced toxicity is associated with the induction of autophagy in human lymphoblastoid cell lines (LCL). Autophagy is a cellular process that functions in the degradation of damaged cellular components, including protein aggregates formed by misfolded or damaged proteins. Accumulation of misfolded or damaged proteins in the endoplasmic reticulum (ER) lumen causes ER stress and activates the unfolded protein response (UPR). In an effort to investigate the mechanism of autophagy induction by arsenite in the LCL model, we examined the potential contribution of ER stress and activation of the UPR. LCL exposed to sodium arsenite for 8-days induced expression of UPR-activated genes, including CHOP and GRP78, at the RNA and the protein level. Evidence for activation of the three arms of the UPR was observed. The arsenite-induced activation of the UPR was associated with an accumulation of protein aggregates containing p62 and LC3, proteins with established roles in the sequestration and autophagic clearance of protein aggregates. Taken together, these data provide evidence that arsenite-induced autophagy is associated with the generation of ER stress, activation of the UPR, and formation of protein aggregates that may be targeted to the lysosome for degradation. -- Highlights: ► Arsenite induces endoplasmic reticulum stress and the unfolded protein response. ► Arsenite induces the formation of protein aggregates that contain p62 and LC3-II. ► Time-course data suggests that arsenite-induced autophagy precedes ER stress.

  17. Altered Hepatic Transport by Fetal Arsenite Exposure in Diet-Induced Fatty Liver Disease.

    PubMed

    Ditzel, Eric J; Li, Hui; Foy, Caroline E; Perrera, Alec B; Parker, Patricia; Renquist, Benjamin J; Cherrington, Nathan J; Camenisch, Todd D

    2016-07-01

    Non-alcoholic fatty liver disease can result in changes to drug metabolism and disposition potentiating adverse drug reactions. Furthermore, arsenite exposure during development compounds the severity of diet-induced fatty liver disease. This study examines the effects of arsenite potentiated diet-induced fatty liver disease on hepatic transport in male mice. Changes were detected for Mrp2/3/4 hepatic transporter gene expression as well as for Oatp1a4/2b1/1b2. Plasma concentrations of Mrp and Oatp substrates were increased in arsenic exposure groups compared with diet-only controls. In addition, murine embryonic hepatocytes and adult primary hepatocytes show significantly altered transporter expression after exposure to arsenite alone: a previously unreported phenomenon. These data indicate that developmental exposure to arsenite leads to changes in hepatic transport which could increase the risk for ADRs during fatty liver disease.

  18. The Green Tea Component (-)-Epigallocatechin-3-Gallate Sensitizes Primary Endothelial Cells to Arsenite-Induced Apoptosis by Decreasing c-Jun N-Terminal Kinase-Mediated Catalase Activity.

    PubMed

    Kim, Jee-Youn; Choi, Ji-Young; Lee, Hyeon-Ju; Byun, Catherine Jeonghae; Park, Jung-Hyun; Park, Jae Hoon; Cho, Ho-Seong; Cho, Sung-Jin; Jo, Sangmee Ahn; Jo, Inho

    2015-01-01

    The green tea component (-)-epigallocatechin-3-gallate (EGCG) has been shown to sensitize many different types of cancer cells to anticancer drug-induced apoptosis, although it protects against non-cancerous primary cells against toxicity from certain conditions such as exposure to arsenic (As) or ultraviolet irradiation. Here, we found that EGCG promotes As-induced toxicity of primary-cultured bovine aortic endothelial cells (BAEC) at doses in which treatment with each chemical alone had no such effect. Increased cell toxicity was accompanied by an increased condensed chromatin pattern and fragmented nuclei, cleaved poly(ADP-ribose) polymerase (PARP), activity of the pro-apoptotic enzymes caspases 3, 8 and 9, and Bax translocation into mitochondria, suggesting the involvement of an apoptotic signaling pathway. Fluorescence activated cell sorting analysis revealed that compared with EGCG or As alone, combined EGCG and As (EGCG/As) treatment significantly induced production of reactive oxygen species (ROS), which was accompanied by decreased catalase activity and increased lipid peroxidation. Pretreatment with N-acetyl-L-cysteine or catalase reversed EGCG/As-induced caspase activation and EC toxicity. EGCG/As also increased the phosphorylation of c-Jun N-terminal kinase (JNK), which was not reversed by catalase. However, pretreatment with the JNK inhibitor SP600125 reversed all of the observed effects of EGCG/As, suggesting that JNK may be the most upstream protein examined in this study. Finally, we also found that all the observed effects by EGCG/As are true for other types of EC tested. In conclusion, this is firstly to show that EGCG sensitizes non-cancerous EC to As-induced toxicity through ROS-mediated apoptosis, which was attributed at least in part to a JNK-activated decrease in catalase activity.

  19. The Green Tea Component (-)-Epigallocatechin-3-Gallate Sensitizes Primary Endothelial Cells to Arsenite-Induced Apoptosis by Decreasing c-Jun N-Terminal Kinase-Mediated Catalase Activity

    PubMed Central

    Lee, Hyeon-Ju; Byun, Catherine Jeonghae; Park, Jung-Hyun; Park, Jae Hoon; Cho, Ho-Seong; Cho, Sung-Jin; Jo, Sangmee Ahn; Jo, Inho

    2015-01-01

    The green tea component (-)-epigallocatechin-3-gallate (EGCG) has been shown to sensitize many different types of cancer cells to anticancer drug-induced apoptosis, although it protects against non-cancerous primary cells against toxicity from certain conditions such as exposure to arsenic (As) or ultraviolet irradiation. Here, we found that EGCG promotes As-induced toxicity of primary-cultured bovine aortic endothelial cells (BAEC) at doses in which treatment with each chemical alone had no such effect. Increased cell toxicity was accompanied by an increased condensed chromatin pattern and fragmented nuclei, cleaved poly(ADP-ribose) polymerase (PARP), activity of the pro-apoptotic enzymes caspases 3, 8 and 9, and Bax translocation into mitochondria, suggesting the involvement of an apoptotic signaling pathway. Fluorescence activated cell sorting analysis revealed that compared with EGCG or As alone, combined EGCG and As (EGCG/As) treatment significantly induced production of reactive oxygen species (ROS), which was accompanied by decreased catalase activity and increased lipid peroxidation. Pretreatment with N-acetyl-L-cysteine or catalase reversed EGCG/As-induced caspase activation and EC toxicity. EGCG/As also increased the phosphorylation of c-Jun N-terminal kinase (JNK), which was not reversed by catalase. However, pretreatment with the JNK inhibitor SP600125 reversed all of the observed effects of EGCG/As, suggesting that JNK may be the most upstream protein examined in this study. Finally, we also found that all the observed effects by EGCG/As are true for other types of EC tested. In conclusion, this is firstly to show that EGCG sensitizes non-cancerous EC to As-induced toxicity through ROS-mediated apoptosis, which was attributed at least in part to a JNK-activated decrease in catalase activity. PMID:26375285

  20. Arsenite-induced autophagy is associated with proteotoxicity in human lymphoblastoid cells.

    PubMed

    Bolt, Alicia M; Zhao, Fei; Pacheco, Samantha; Klimecki, Walter T

    2012-10-15

    Epidemiological studies of arsenic-exposed populations have provided evidence that arsenic exposure in humans is associated with immunosuppression. Previously, we have reported that arsenite-induced toxicity is associated with the induction of autophagy in human lymphoblastoid cell lines (LCL). Autophagy is a cellular process that functions in the degradation of damaged cellular components, including protein aggregates formed by misfolded or damaged proteins. Accumulation of misfolded or damaged proteins in the endoplasmic reticulum (ER) lumen causes ER stress and activates the unfolded protein response (UPR). In an effort to investigate the mechanism of autophagy induction by arsenite in the LCL model, we examined the potential contribution of ER stress and activation of the UPR. LCL exposed to sodium arsenite for 8-days induced expression of UPR-activated genes, including CHOP and GRP78, at the RNA and the protein level. Evidence for activation of the three arms of the UPR was observed. The arsenite-induced activation of the UPR was associated with an accumulation of protein aggregates containing p62 and LC3, proteins with established roles in the sequestration and autophagic clearance of protein aggregates. Taken together, these data provide evidence that arsenite-induced autophagy is associated with the generation of ER stress, activation of the UPR, and formation of protein aggregates that may be targeted to the lysosome for degradation.

  1. Reduction of arsenite-enhanced ultraviolet radiation-induced DNA damage by supplemental zinc

    PubMed Central

    Cooper, Karen L.; King, Brenee S.; Sandoval, Monica M.; Liu, Ke Jian; Hudson, Laurie G.

    2013-01-01

    Arsenic is a recognized human carcinogen and there is evidence that arsenic augments the carcinogenicity of DNA damaging agents such as ultraviolet radiation (UVR) thereby acting as a co-carcinogen. Inhibition of DNA repair is one proposed mechanism to account for the co-carcinogenic actions of arsenic. We and others find that arsenite interferes with the function of certain zinc finger DNA repair proteins. Furthermore, we reported that zinc reverses the effects of arsenite in cultured cells and a DNA repair target protein, poly (ADP-ribose) polymerase-1. In order to determine whether zinc ameliorates the effects of arsenite on UVR-induced DNA damage in human keratinocytes and in an in vivo model, normal human epidermal keratinocytes and SKH-1 hairless mice were exposed to arsenite, zinc or both before solar-simulated (ss) UVR exposure. Poly (ADP-ribose) polymerase activity, DNA damage and mutation frequencies at the hprt locus were measured in each treatment group in normal human keratinocytes. DNA damage was assessed in vivo by immunohistochemical staining of skin sections isolated from SKH-1 hairless mice. Cell-based findings demonstrate that ssUVR-induced DNA damage and mutagenesis are enhanced by arsenite, and supplemental zinc partially reverses the arsenite effect. In vivo studies confirm that zinc supplementation decreases arsenite-enhanced DNA damage in response to ssUVR exposure. From these data we can conclude that zinc offsets the impact of arsenic on ssUVR-stimulated DNA damage in cells and in vivo suggesting that zinc supplementation may provide a strategy to improve DNA repair capacity in arsenic exposed human populations. PMID:23523584

  2. APOPTOSIS GENE EXPRESSION IN HUMAN EPDERMAL KERATINOCYTES TREATED WITH SODIUM ARSENITE USING REAL TIME PCR ARRAY

    EPA Science Inventory

    Arsenic exposure via contaminated drinking water is a great public health concern worldwide. Chronic arsenic exposure has been associated with human skin, lung and bladder cancer and other chronic effects. We have previous reported that sodium arsenite stimulated cell proliferati...

  3. Induction of apoptotic death and retardation of neuronal differentiation of human neural stem cells by sodium arsenite treatment

    SciTech Connect

    Ivanov, Vladimir N.; Hei, Tom K.

    2013-04-01

    Chronic arsenic toxicity is a global health problem that affects more than 100 million people worldwide. Long-term health effects of inorganic sodium arsenite in drinking water may result in skin, lung and liver cancers and in severe neurological abnormalities. We investigated in the present study whether sodium arsenite affects signaling pathways that control cell survival, proliferation and neuronal differentiation of human neural stem cells (NSC). We demonstrated that the critical signaling pathway, which was suppressed by sodium arsenite in NSC, was the protective PI3K–AKT pathway. Sodium arsenite (2–4 μM) also caused down-regulation of Nanog, one of the key transcription factors that control pluripotency and self-renewal of stem cells. Mitochondrial damage and cytochrome-c release induced by sodium arsenite exposure was followed by initiation of the mitochondrial apoptotic pathway in NSC. Beside caspase-9 and caspase-3 inhibitors, suppression of JNK activity decreased levels of arsenite-induced apoptosis in NSC. Neuronal differentiation of NSC was substantially inhibited by sodium arsenite exposure. Overactivation of JNK1 and ERK1/2 and down-regulation of PI3K–AKT activity induced by sodium arsenite were critical factors that strongly affected neuronal differentiation. In conclusion, sodium arsenite exposure of human NSC induces the mitochondrial apoptotic pathway, which is substantially accelerated due to the simultaneous suppression of PI3K–AKT. Sodium arsenite also negatively affects neuronal differentiation of NSC through overactivation of MEK–ERK and suppression of PI3K–AKT. - Highlights: ► Arsenite induces the mitochondrial apoptotic pathway in human neural stem cells. ► Arsenite-induced apoptosis is strongly upregulated by suppression of PI3K–AKT. ► Arsenite-induced apoptosis is strongly down-regulated by inhibition of JNK–cJun. ► Arsenite negatively affects neuronal differentiation by inhibition of PI3K–AKT.

  4. Posttreatment with sodium arsenite alters the mutational spectrum induced by ultraviolet light irradiation in Chinese hamster ovary cells

    SciTech Connect

    Yang, Jia-Ling; Chen, Mei-Fang; Wu, Cheng-Wen; Lee, Te-Chang )

    1992-01-01

    Arsenic, a potent carcinogen, fails to induce gene mutations in mammalian cells. However, posttreatment of ultraviolet light (UV)-irradiated cells with sodium arsenite synergstically enhances the mutation frequency on the hypoxanthine (Guanine) phosphoribosyltransferase locus. To investigate the molecular mechanism of the comutagenic effects of sodium arsenite, the authors characterized the alternations of nucleotide sequences in 30 UV-induced and 39 sodium arsenite enhanced hprt mutants from CHinese hamster ovary K1 cells by direct sequencing of mRNA-PCR amplified cDNA. The majority of sequence alterations derived from UV irradiation (80%) and from sodium arsenite posttreatment (70%) were single base substitutions. UV irradiation induced all types of base substitutions. Among them, 57% were transversions. The frequency of transversion increased to 70% in sodium arsenite enhanced mutants. While base substitutions observed in UV-induced mutants were evenly distributed along with the whole coding region, exons 3 and 8 were most frequently mutated in sodium arsenite enhanced mutants. Sodium arsenite posttreatment did not alter the strand bias for mutation induction, i.e., 73% and 78%, of the mutations were located on the non-transcribed strand in UV-induced and sodium arsenite enhanced mutants, respectively. In contrast to UV-induced mutations, bases at the 5' position of TT and the 3' position of CT sequences were the most frequent mutation sites observed in sodium arsenite enhanced mutants. The authors hypothesize that sodium arsenite may interfere with the process of mutation fixation of TT and CT dimers during DNA replication. 50 refs., 2 figs., 6 tabs.

  5. THE EFFECTS OF HEAT SHOCK PROTEIN 70 (HSP70) AND EXPOSURE PROTOCOL ON ARSENITE INDUCED GENOTOXICITY

    EPA Science Inventory

    The Effects of Heat Shock Protein 70 (Hsp70) and Exposure Protocol on Arsenite Induced Genotoxicity

    Barnes, J.A.1,2, Collins, B.W.2, Dix, D.J.3 and Allen J.W2.
    1National Research Council, 2Environmental Carcinogenesis Division, 3Reproductive Toxicology Division, Office...

  6. The metalloid arsenite induces nuclear export of Id3 possibly via binding to the N-terminal cysteine residues

    SciTech Connect

    Kurooka, Hisanori; Sugai, Manabu; Mori, Kentaro; Yokota, Yoshifumi

    2013-04-19

    Highlights: •Sodium arsenite induces cytoplasmic accumulation of Id3. •Arsenite binds to closely spaced N-terminal cysteine residues of Id3. •N-terminal cysteines are essential for arsenite-induced nuclear export of Id3. •Nuclear export of Id3 counteracts its transcriptional repression activity. -- Abstract: Ids are versatile transcriptional repressors that regulate cell proliferation and differentiation, and appropriate subcellular localization of the Id proteins is important for their functions. We previously identified distinct functional nuclear export signals (NESs) in Id1 and Id2, but no active NES has been reported in Id3. In this study, we found that treatment with the stress-inducing metalloid arsenite led to the accumulation of GFP-tagged Id3 in the cytoplasm. Cytoplasmic accumulation was impaired by a mutation in the Id3 NES-like sequence resembling the Id1 NES, located at the end of the HLH domain. It was also blocked by co-treatment with the CRM1-specific nuclear export inhibitor leptomycin B (LMB), but not with the inhibitors for mitogen-activated protein kinases (MAPKs). Importantly, we showed that the closely spaced N-terminal cysteine residues of Id3 interacted with the arsenic derivative phenylarsine oxide (PAO) and were essential for the arsenite-induced cytoplasmic accumulation, suggesting that arsenite induces the CRM1-dependent nuclear export of Id3 via binding to the N-terminal cysteines. Finally, we demonstrated that Id3 significantly repressed arsenite-stimulated transcription of the immediate-early gene Egr-1 and that this repression activity was inversely correlated with the arsenite-induced nuclear export. Our results imply that Id3 may be involved in the biological action of arsenite.

  7. From the Cover: Arsenite Uncouples Mitochondrial Respiration and Induces a Warburg-like Effect in Caenorhabditis elegans.

    PubMed

    Luz, Anthony L; Godebo, Tewodros R; Bhatt, Dhaval P; Ilkayeva, Olga R; Maurer, Laura L; Hirschey, Matthew D; Meyer, Joel N

    2016-08-01

    Millions of people worldwide are chronically exposed to arsenic through contaminated drinking water. Despite decades of research studying the carcinogenic potential of arsenic, the mechanisms by which arsenic causes cancer and other diseases remain poorly understood. Mitochondria appear to be an important target of arsenic toxicity. The trivalent arsenical, arsenite, can induce mitochondrial reactive oxygen species production, inhibit enzymes involved in energy metabolism, and induce aerobic glycolysis in vitro, suggesting that metabolic dysfunction may be important in arsenic-induced disease. Here, using the model organism Caenorhabditis elegans and a novel metabolic inhibition assay, we report an in vivo induction of aerobic glycolysis following arsenite exposure. Furthermore, arsenite exposure induced severe mitochondrial dysfunction, including altered pyruvate metabolism; reduced steady-state ATP levels, ATP-linked respiration and spare respiratory capacity; and increased proton leak. We also found evidence that induction of autophagy is an important protective response to arsenite exposure. Because these results demonstrate that mitochondria are an important in vivo target of arsenite toxicity, we hypothesized that deficiencies in mitochondrial electron transport chain genes, which cause mitochondrial disease in humans, would sensitize nematodes to arsenite. In agreement with this, nematodes deficient in electron transport chain complexes I, II, and III, but not ATP synthase, were sensitive to arsenite exposure, thus identifying a novel class of gene-environment interactions that warrant further investigation in the human populace.

  8. Aqueous and ethanolic leaf extracts of Ocimum basilicum (sweet basil) protect against sodium arsenite-induced hepatotoxicity in Wistar rats.

    PubMed

    Gbadegesin, M A; Odunola, O A

    2010-11-25

    We evaluated the effects of aqueous and ethanolic leaf extracts of Ocimum basilicum (sweet basil) on sodium arsenite-induced hepatotoxicity in Wistar rats. We observed that treatment of the animals with the extracts before or just after sodium arsenite administration significantly (p < 0.05) reduced mean liver and serum γ-Glutamyl transferase (γGT), and serum alkaline phosphatase (ALP) activities when compared with the group administered the toxin alone. In addition, treatments of the animals with aqueous or ethanolic extract of O. basilicum before the administration of sodium arsenite resulted in the attenuation of the sodium arsenite-induced aspartate and alanine aminotransferase activities: ALT (from 282.6% to 167.7% and 157.8%), AST (from 325.1% to 173.5% and 164.2%) for the group administered sodium arsenite alone, the aqueous extracts plus sodium arsenite, and ethanolic extracts plus sodium arsenite respectively, expressed as percentage of the negative control. These findings support the presence of hepatoprotective activity in the O.basilicum extracts.

  9. Induction of heme oxygenase 1 by arsenite inhibits cytokine-induced monocyte adhesion to human endothelial cells

    SciTech Connect

    Sun Xi; Pi Jingbo; Liu Wenlan; Hudson, Laurie G.; Liu Kejian; Feng Changjian

    2009-04-15

    Heme oxygenase-1 (HO-1) is an oxidative stress responsive gene upregulated by various physiological and exogenous stimuli. Arsenite, as an oxidative stressor, is a potent inducer of HO-1 in human and rodent cells. In this study, we investigated the mechanistic role of arsenite-induced HO-1 in modulating tumor necrosis factor {alpha} (TNF-{alpha}) induced monocyte adhesion to human umbilical vein endothelial cells (HUVEC). Arsenite pretreatment, which upregulated HO-1 in a time- and concentration-dependent manner, inhibited TNF-{alpha}-induced monocyte adhesion to HUVEC and intercellular adhesion molecule 1 protein expression by 50% and 40%, respectively. Importantly, knockdown of HO-1 by small interfering RNA abolished the arsenite-induced inhibitory effects. These results indicate that induction of HO-1 by arsenite inhibits the cytokine-induced monocyte adhesion to HUVEC by suppressing adhesion molecule expression. These findings established an important mechanistic link between the functional monocyte adhesion properties of HUVEC and the induction of HO-1 by arsenite.

  10. Coenzyme Q10 counteracts testicular injury induced by sodium arsenite in rats.

    PubMed

    Fouad, Amr A; Al-Sultan, Ali Ibrahim; Yacoubi, Mohamed T

    2011-03-25

    The protective effect of coenzyme Q10 against testicular toxicity induced by sodium arsenite (10mg/kg/day, orally for two consecutive days) was investigated in rats. Coenzyme Q10 treatment (10mg/kg/day, i.p.) was applied for five consecutive days, starting three days before arsenite administration. Coenzyme Q10 significantly increased serum testosterone level which was reduced by sodium arsenite. Coenzyme Q10 significantly suppressed lipid peroxidation, restored the depleted antioxidant defenses, and attenuated the increases of tumor necrosis factor-α and nitric oxide resulted from arsenic administration. Also, the elevation of arsenic ion, and the reductions of selenium and zinc ions in testicular tissue were mitigated by coenzyme Q10. Histopathological examination showed that testicular injury mediated by arsenic was ameliorated by coenzyme Q10 treatment. Immunohistochemical analysis revealed that coenzyme Q10 significantly decreased the arsenic-induced expression of inducible nitric oxide synthase, nuclear factor-κB, Fas ligand and caspase-3 in testicular tissue. It was concluded that coenzyme Q10 represents a potential therapeutic option to protect the testicular tissue from the detrimental effects of arsenic intoxication.

  11. Protection of Nrf2 against arsenite-induced oxidative damage is regulated by the cyclic guanosine monophosphate-protein kinase G signaling pathway.

    PubMed

    Chen, Chengzhi; Jiang, Xuejun; Gu, Shiyan; Lai, Yanhao; Liu, Yuan; Zhang, Zunzhen

    2016-10-24

    Arsenite has been shown to induce a variety of oxidative damage in mammalian cells. However, the mechanisms underlying cellular responses to its adverse effects remain unknown. We previously showed that the level of Nrf2, a nuclear transcription factor significantly increased in arsenite-treated human bronchial epithelial (HBE) cells suggesting that Nrf2 is involved in responding to arsenite-induced oxidative damage. To explore how Nrf2 can impact arsenite-induced oxidative damage, in this study, we examined Nrf2 activation and its regulation upon cellular arsenite exposure as well as its effects on arsenite-induced oxidative damage in HBE cells. We found that Nrf2 mRNA and protein levels were significantly increased by arsenite in a dose- and time-dependent manner. Furthermore, we showed that over-expression of Nrf2 significantly reduced the level of arsenite-induced oxidative damage in HBE cells including DNA damage, chromosomal breakage, lipid peroxidation and depletion of antioxidants. This indicates a protective role of Nrf2 against arsenite toxicity. This was further supported by the fact that activation of Nrf2 by its agonists, tertiary butylhydroquinone (t-BHQ) and sulforaphane (SFN) resulted in the same protective effects against arsenite toxicity. Moreover, we demonstrated that arsenite-induced activation of Nrf2 was mediated by the cyclic guanosine monophosphate (cGMP)-protein kinase G (PKG) signaling pathway. This is the first evidence showing that Nrf2 protects against arsenite-induced oxidative damage through the cGMP-PKG pathway. Our study suggests that activation of Nrf2 through the cGMP-PKG signaling pathway in HBE cells may be developed as a new strategy for prevention of arsenite toxicity. © 2016 Wiley Periodicals, Inc. Environ Toxicol, 2016.

  12. Arsenite induces cell transformation by reactive oxygen species, AKT, ERK1/2, and p70S6K1

    SciTech Connect

    Carpenter, Richard L.; Jiang, Yue; Jing, Yi; He, Jun; Rojanasakul, Yon; Liu, Ling-Zhi; Jiang, Bing-Hua

    2011-10-28

    Highlights: Black-Right-Pointing-Pointer Chronic exposure to arsenite induces cell proliferation and transformation. Black-Right-Pointing-Pointer Arsenite-induced transformation increases ROS production and downstream signalings. Black-Right-Pointing-Pointer Inhibition of ROS levels via catalase reduces arsenite-induced cell transformation. Black-Right-Pointing-Pointer Interruption of AKT, ERK, or p70S6K1 inhibits arsenite-induced cell transformation. -- Abstract: Arsenic is naturally occurring element that exists in both organic and inorganic formulations. The inorganic form arsenite has a positive association with development of multiple cancer types. There are significant populations throughout the world with high exposure to arsenite via drinking water. Thus, human exposure to arsenic has become a significant public health problem. Recent evidence suggests that reactive oxygen species (ROS) mediate multiple changes to cell behavior after acute arsenic exposure, including activation of proliferative signaling and angiogenesis. However, the role of ROS in mediating cell transformation by chronic arsenic exposure is unknown. We found that cells chronically exposed to sodium arsenite increased proliferation and gained anchorage-independent growth. This cell transformation phenotype required constitutive activation of AKT, ERK1/2, mTOR, and p70S6K1. We also observed these cells constitutively produce ROS, which was required for the constitutive activation of AKT, ERK1/2, mTOR, and p70S6K1. Suppression of ROS levels by forced expression of catalase also reduced cell proliferation and anchorage-independent growth. These results indicate cell transformation induced by chronic arsenic exposure is mediated by increased cellular levels of ROS, which mediates activation of AKT, ERK1/2, and p70S6K1.

  13. Arsenite induces endothelial cell permeability increase through a reactive oxygen species-vascular endothelial growth factor pathway.

    PubMed

    Bao, Lingzhi; Shi, Honglian

    2010-11-15

    As a potent environmental oxidative stressor, arsenic exposure has been reported to exacerbate cardiovascular diseases and increase vascular endothelial cell monolayer permeability. However, the underlying mechanism of this effect is not well understood. In this paper, we test our hypothesis that reactive oxygen species (ROS)-induced vascular endothelial growth factor (VEGF) expression may play an important role in an arsenic-caused increase of endothelial cell monolayer permeability. The mouse brain vascular endothelial cell bEnd3 monolayer was exposed to arsenite for 1, 3, and 6 days. The monolayer permeability, VEGF protein release, and ROS generation were determined. In addition, VE-cadherin and zonula occludens-1 (ZO-1), two membrane structure proteins, were immunostained to elucidate the effects of arsenite on the cell-cell junction. The roles of ROS and VEGF in arsenite-induced permeability was determined by inhibiting ROS with antioxidants and immuno-depleting VEGF with a VEGF antibody. We observed that arsenite increased bEnd3 monolayer permeability, elevated the production of cellular ROS, and increased VEGF release. VE-cadherin and ZO-1 disruptions were also found in cells treated with arsenite. Furthermore, both antioxidant (N-acetyl cysteine and tempol) and the VEGF antibody treatments significantly lowered the arsenite-induced permeability of the bEnd3 monolayer as well as VEGF expression. VE-cadherin and ZO-1 disruptions were also diminished by N-acetyl cysteine and the VEGF antibody. Our data suggest that the increase in VEGF expression caused by ROS may play an important role in the arsenite-induced increase in endothelial cell permeability.

  14. Possible vasculoprotective role of linagliptin against sodium arsenite-induced vascular endothelial dysfunction.

    PubMed

    Jyoti, Uma; Kansal, Sunil Kumar; Kumar, Puneet; Goyal, Sandeep

    2016-02-01

    Vascular endothelial dysfunction (VED) interrupts the integrity and function of endothelial lining through enhanced markers of oxidative stress and decrease endothelial nitric oxide synthase (eNOS) expression. The main aim of the present study has been designed to investigate the possible vasculoprotective role of linagliptin against sodium arsenite-induced VED. Sodium arsenite (1.5 mg/kg, i.p., 2 weeks) abrogated the acetylcholine-induced, endothelium-dependent vasorelaxation by depicting the decrease in serum nitrite/nitrate concentration, reduced glutathione level, and simultaneously enhance the thiobarbituric acid reactive substances (TBARS) level, superoxide level, and tumor necrosis factor-alpha. These elevated markers interrupt the integrity of endothelial lining of thoracic aorta which was assessed histologically. The study elicits dose dependent effect of linagliptin (1.5 mg/kg, i.p. and 3 mg/kg, i.p.) or atorvastatin (30 mg/kg, p.o.) treatment, improved the endothelium-dependent independent relaxation, improve the integrity of endothelium lining which was assessed histologically by enhancing the serum nitrite/nitrate level, reduced glutathione level and simultaneously decreasing the TBARS level, superoxide anion level and tumor necrosis factor-alpha (TNF-α) level. L-NAME (25 mg/kg, i.p.), eNOS inhibitor, abrogated the ameliorative potential of linagliptin. However, the ameliorative potential of linagliptin has been enhanced by l-arginine (200 mg/kg, i.p.) which elicits that ameliorative potential of linagliptin was through eNOS signaling cascade and it may be concluded that linagliptin 3 mg/kg, i.p. has more significantly activated the eNOS and decreased the oxidative markers than linagliptin 1.5 mg/kg, i.p. and prevented sodium arsenite-induced VED.

  15. Ameliorative Effects of Acacia Honey against Sodium Arsenite-Induced Oxidative Stress in Some Viscera of Male Wistar Albino Rats

    PubMed Central

    Aliyu, Muhammad; Ibrahim, Sani; Inuwa, Hajiya M.; Sallau, Abdullahi B.; Abbas, Olagunju; Aimola, Idowu A.; Habila, Nathan; Uche, Ndidi S.

    2013-01-01

    Cancer is a leading cause of death worldwide and its development is frequently associated with oxidative stress-induced by carcinogens such as arsenicals. Most foods are basically health-promoting or disease-preventing and a typical example of such type is honey. This study was undertaken to investigate the ameliorative effects of Acacia honey on sodium arsenite-induced oxidative stress in the heart, lung and kidney tissues of male Wistar rats. Male Wistar albino rats divided into four groups of five rats each were administered distilled water, Acacia honey (20%), sodium arsenite (5 mg/kg body weight), Acacia honey, and sodium arsenite daily for one week. They were sacrificed anesthetically using 60 mg/kg sodium pentothal. The tissues were used for the assessment of glutathione peroxidase, catalase, and superoxide dismutase activities, protein content and lipid peroxidation. Sodium arsenite significantly (P < 0.05) suppressed the glutathione peroxidase, catalase, superoxide dismutase activities with simultaneous induction of lipid peroxidation. Administration of Acacia honey significantly increased (P < 0.05) glutathione peroxidase, catalase, and superoxide dismutase activities with concomitant suppression of lipid peroxidation as evident by the decrease in malondialdehyde level. From the results obtained, Acacia honey mitigates sodium arsenite induced-oxidative stress in male Wistar albino rats, which suggest that it may attenuate oxidative stress implicated in chemical carcinogenesis. PMID:24368942

  16. Sodium arsenite-induced cardiotoxicity in rats: protective role of p-coumaric acid, a common dietary polyphenol.

    PubMed

    Prasanna, Nagalakshmi; Krishnan, Dhanalakshmi Navaneethan; Rasool, Mahaboobkhan

    2013-05-01

    This study was performed to investigate the ameliorative role of p-coumaric acid against sodium arsenite-induced cardiotoxicity in rats. Sodium arsenite (5 mg/kg/b.wt) was orally administered once a day for 30 days to the animals to induce cardiotoxicity. After the experimental period, cardiotoxicity was assessed by estimating the levels of lipid peroxidation, anti-oxidant status (superoxide dismutase, catalase, glutathione peroxidase, glutathione S-transferase, glutathione reductase, total reduced glutathione, protein sulfyhydryl and non-protein sulfhydryl groups) and DNA fragmentation in the cardiac tissue of control and experimental rats. In addition, cardiac tissue specific serum markers (triacylglycerides, total cholesterol, low-density lipoprotein cholesterol and high density lipoprotein cholesterol) in serum and histopathological changes in the cardiac tissue were also evaluated. From the results obtained in our study, sodium arsenite administration to the rats increased lipid peroxidation, DNA fragmentation, triacylglycerides, total cholesterol and low-density lipoprotein cholesterol, whereas antioxidant status and high-density lipoprotein cholesterol were found to be reduced. However, p-coumaric acid (75 and100 mg/kg/b.wt) treatment orally once per day for 30 days, immediately before a daily administration of sodium arsenite protected the abnormal biochemical abnormalities observed in the cardiac tissue of sodium arsenite treated rats as evidenced by the cardiac histopathology. For comparison purpose, a standard antioxidant vitamin C (100 mg/kg/b.wt) was used. In conclusion, this study concluded that p-coumaric acid could be a promising candidate for protecting the sodium arsenite-induced cardiotoxicity in rats through its antioxidant character.

  17. In Vitro Protective Potentials of Annona muricata Leaf Extracts Against Sodium Arsenite-induced Toxicity.

    PubMed

    George, Vazhappilly Cijo; Kumar, Devanga Ragupathi Naveen; Suresh, Palamadai Krishnan; Kumar, Rangasamy Ashok

    2015-01-01

    Sodium arsenite (NaAsO2) is a metalloid which is present widely in the environment and its chronic exposure can contribute to the induction of oxidative stress, resulting in disturbances in various metabolic functions including liver cell death. Hence, there is a need to develop drugs from natural sources, which can reduce arsenic toxicity. While there have been reports regarding the antioxidant and protective potentials of Annona muricataleaf extracts, our study is the first ofits kind to extend these findings by specifically evaluating its ability to render protection against sodium arsenite (NaAsO2) induced toxicity (10 μM) in WRL-68 (human hepatic cells) and human erythrocytes by employing XTT and haemolysis inhibition assays respectively. The methanolic extract exhibited higher activity than the aqueous extract in both assays. The results showed a dose-dependent decrease in arsenic toxicity in both WRL-68 cells and erythrocytes, suggesting the protective nature of Annona muricatato mitigate arsenic toxicity. Hence the bioactive extracts can further be scrutinized for the identification and characterization of their principal contributors.

  18. EFFECT OF EXPOSURE PROTOCOL AND HEAT SHOCK PROTEIN EXPRESSION ON ARSENITE INDUCED GENOTOXICITY IN MCF-7 BREAST CANCER CELLS

    EPA Science Inventory


    Effect of exposure protocol and heat shock protein expression on arsenite induced genotoxicity in MCF-7 breast cancer cells

    The genotoxic effects of arsenic (As) are well accepted, yet its mechanism of action is not clearly defined. Heat-shock proteins (HSPs) protect...

  19. MicroRNA-21 activation of ERK signaling via PTEN is involved in arsenite-induced autophagy in human hepatic L-02 cells.

    PubMed

    Liu, Xinlu; Luo, Fei; Ling, Min; Lu, Lu; Shi, Le; Lu, Xiaolin; Xu, Hui; Chen, Chao; Yang, Qianlei; Xue, Junchao; Li, Jun; Zhang, Aihua; Liu, Qizhan

    2016-06-11

    Autophagy, an evolutionarily conserved cellular process, has diverse physiological and pathological roles in biological functions. Whether autophagy is induced by arsenite, a well-established human carcinogen, and the molecular mechanisms involved, remain to be established. Further, microRNAs (miRNAs) act as regulators in various cancers, but how miRNAs regulate autophagy remains largely unexplored. We have found that, in human hepatic epithelial (L-02) cells, arsenite increases levels of autophagy-related proteins in a concentration- and time-dependent manner and elevates the number of autophagic vacuoles (AVs). Arsenite also activates the ERK pathway in a dose- and time-dependent manner. In L-02 cells exposed to arsenite, microRNA-21 (miRNA-21) is over-expressed, and its target proteins, PTEN, PDCD4, and Spry1, are decreased. Moreover, inhibition of miR-21 increases levels of PTEN, and reduces levels of Beclin 1 and LC3 II/I, indicating that miR-21 is involved in arsenite-induced autophagy. In addition, ectopic expression of PTEN blocks the effect of miR-21 on the arsenite-induced autophagy and decreases p-ERK levels. Also, ERK promotes the autophagy induced by arsenite. In sum, upon exposure of cells to arsenite, over-expression of miR-21 activates ERK through PTEN, factors that participate in arsenite-induced autophagy. This link, mediated through miRNAs, establishes a mechanism for the development of autophagy that is associated with arsenic toxicity. Such information contributes to an understanding of the liver toxicity caused by arsenite.

  20. Arsenite-Induced Pseudo-Hypoxia Results in Loss of Anchorage-Dependent Growth in BEAS-2B Pulmonary Epithelial Cells

    PubMed Central

    Zhao, Fei; Malm, Scott W.; Hinchman, Alyssa N.; Li, Hui; Beeks, Connor G.; Klimecki, Walter T.

    2014-01-01

    Epidemiology studies have established a strong link between lung cancer and arsenic exposure. Currently, the role of disturbed cellular energy metabolism in carcinogenesis is a focus of scientific interest. Hypoxia inducible factor-1 alpha (HIF-1A) is a key regulator of energy metabolism, and it has been found to accumulate during arsenite exposure under oxygen-replete conditions. We modeled arsenic-exposed human pulmonary epithelial cells in vitro with BEAS-2B, a non-malignant lung epithelial cell line. Constant exposure to 1 µM arsenite (As) resulted in the early loss of anchorage-dependent growth, measured by soft agar colony formation, beginning at 6 weeks of exposure. This arsenite exposure resulted in HIF-1A accumulation and increased glycolysis, similar to the physiologic response to hypoxia, but in this case under oxygen-replete conditions. This “pseudo-hypoxia” response was necessary for the maximal acquisition of anchorage-independent growth in arsenite-exposed BEAS-2B. The HIF-1A accumulation and induction in glycolysis was sustained throughout a 52 week course of arsenite exposure in BEAS-2B. There was a time-dependent increase in anchorage-independent growth during the exposure to arsenite. When HIF-1A expression was stably suppressed, arsenite-induced glycolysis was abrogated, and the anchorage-independent growth was reduced. These findings establish that arsenite exerts a hypoxia-mimetic effect, which plays an important role in the subsequent gain of malignancy-associated phenotypes. PMID:25513814

  1. Differential effects of luminol, nickel, and arsenite on the rejoining of ultraviolet light and alkylation-induced DNA breaks

    SciTech Connect

    Lee-Chen, S.F.; Yu, C.T.; Wu, D.R.

    1994-12-31

    When Chinese hamster ovary cells were treated with ultraviolet (UV) light or methyl methane-sulfonate (MMS), a large number of DNA strand breaks could be detected by alkaline elution. These strand breaks gradually disappeared if the treated cells were allowed to recover in a drug-free medium. The presence of nickel or arsenite during the recovery incubation retarded the disappearance of UV-induced strand breaks, whereas the disappearance of MMS-induced strand breaks was retarded by the presence of arsenite or of luminol, a new inhibit for poly(ADP-ribose) synthetase. Luminol, however, had no apparent effect on the repair of UV-induced DNA strand breaks, and nickel had no effect on the repair of MMS-induced DNA strand breaks. When UV- or MMS-treated cells were incubated in cytosine arabinofuranoside (AraC) plus hydroxyurea (HU), a large amount of low molecular weight DNA was detected by alkaline sucrose sedimentation. The molecular weight of these DNAs increased if the cells were further incubated in a drug-free medium. This rejoining of breaks in cells pretreated with UV plus AraC and HU was inhibited by nickel and by arsenite, but not by luminol. The rejoining of breaks in cells pretreated with MMS plus AraC and HU was inhibited by luminol and by arsenite, but not by nickel. These results suggest that different enzymes may be used in DNA resynthesis and/or ligation during the repairing of UV- and MMS-induced DNA strand breaks, and that nickel, luminol, and arsenite may have differential inhibitory effects on these enzymes. 29 refs., 4 figs., 1 tab.

  2. c-Jun/AP-1 pathway-mediated cyclin D1 expression participates in low dose arsenite-induced transformation in mouse epidermal JB6 Cl41 cells

    SciTech Connect

    Zhang Dongyun; Li Jingxia; Gao Jimin; Huang Chuanshu

    2009-02-15

    Arsenic is a well-documented human carcinogen associated with skin carcinogenesis. Our previous work reveals that arsenite exposure is able to induce cell transformation in mouse epidermal cell JB6 Cl41 through the activation of ERK, rather than JNK pathway. Our current studies further evaluate downstream pathway in low dose arsenite-induced cell transformation in JB6 Cl41 cells. Our results showed that treatment of cells with low dose arsenite induced activation of c-Jun/AP-1 pathway, and ectopic expression of dominant negative mutant of c-Jun (TAM67) blocked arsenite-induced transformation. Furthermore, our data indicated that cyclin D1 was an important downstream molecule involved in c-Jun/AP-1-mediated cell transformation upon low dose arsenite exposure, because inhibition of cyclin D1 expression by its specific siRNA in the JB6 Cl41 cells resulted in impairment of anchorage-independent growth of cells induced by low dose arsenite. Collectively, our results demonstrate that c-Jun/AP-1-mediated cyclin D1 expression is at least one of the key events implicated in cell transformation upon low dose arsenite exposure.

  3. Acute Sodium Arsenite-Induced Hematological and Biochemical Changes in Wistar Rats: Protective Effects of Ethanol Extract of Ageratum conyzoides

    PubMed Central

    Ola-Davies, Olufunke Eunice; Akinrinde, Akinleye Stephen

    2016-01-01

    Background: Ageratum conyzoides L. (Asteraceae) is an annual herbaceous plant used in folklore medicine for the treatment of a wide range of diseases. Objective: To investigate the protective effect of the ethanol leaf extract of A. conyzoides (EEAC) against hematological, serum biochemical and histological alterations induced by Sodium arsenite administration to Wistar rats. Materials and Methods: Twenty male Wistar rats were randomly assigned into four groups of five rats each. Group I received propylene glycol and Group II rats were given the (EEAC, 100 mg/kg b.w.) orally for 7 days. Group III were given a single oral dose of sodium arsenite (NaAsO2, 2.5 mg/kg b.w.). Animals in Group IV were pretreated with 100 mg/kg EEAC for 7 days followed by a single oral dose of sodium arsenite. Results: Arsenic exposure resulted in significant reductions (P < 0.05) in values of packed cell volume (PCV), hemoglobin concentration (Hb) and red blood cell (RBC) count, and elevation in total white blood cell (WBC) count with insignificant reductions in serum total protein, albumin, and globulin levels. Alterations in aspartate aminotransferase, alanine transferase, alkaline phosphatase, and gamma glutamyl transferase activities, as well as in serum levels of urea, creatinine, glucose, cholesterol, and triglyceride levels, were not statistically significant. EEAC significantly restored (P < 0.05) the PCV, Hb, RBC, and WBC as well as serum albumin, globulin, and total protein to normal values. Conclusion: The results of this study indicate that EEAC possess strong potentials to protect against toxicities induced by sodium arsenite. SUMMARY Ageratum conyzoides produced significant reversal of the reduction in the erythrocytic indices (packed cell volume, red blood cell, and Hb) caused by sodium arseniteSodium arsenite-induced slight elevations in serum aspartate aminotransferase (AST), alanine transaminase (ALT), and alkaline phosphatase (ALP), correlating with the

  4. Stress-induced Start Codon Fidelity Regulates Arsenite-inducible Regulatory Particle-associated Protein (AIRAP) Translation*

    PubMed Central

    Zach, Lolita; Braunstein, Ilana; Stanhill, Ariel

    2014-01-01

    Initial steps in protein synthesis are highly regulated processes as they define the reading frame of the translation machinery. Eukaryotic translation initiation is a process facilitated by numerous factors (eIFs), aimed to form a “scanning” mechanism toward the initiation codon. Translation initiation of the main open reading frame (ORF) in an mRNA transcript has been reported to be regulated by upstream open reading frames (uORFs) in a manner of re-initiation. This mode of regulation is governed by the phosphorylation status of eIF2α and controlled by cellular stresses. Another mode of translational initiation regulation is leaky scanning, and this regulatory process has not been extensively studied. We have identified arsenite-inducible regulatory particle-associated protein (AIRAP) transcript to be translationally induced during arsenite stress conditions. AIRAP transcript contains a single uORF in a poor-kozak context. AIRAP translation induction is governed by means of leaky scanning and not re-initiation. This induction of AIRAP is solely dependent on eIF1 and the uORF kozak context. We show that eIF1 is phosphorylated under specific conditions that induce protein misfolding and have biochemically characterized this site of phosphorylation. Our data indicate that leaky scanning like re-initiation is responsive to stress conditions and that leaky scanning can induce ORF translation by bypassing poor kozak context of a single uORF transcript. PMID:24898249

  5. Arsenite exposure in human lymphoblastoid cell lines induces autophagy and coordinated induction of lysosomal genes.

    PubMed

    Bolt, Alicia M; Douglas, Randi M; Klimecki, Walter T

    2010-11-30

    Chronic exposure to inorganic arsenic is associated with diverse, complex diseases, making the identification of the mechanism underlying arsenic-induced toxicity a challenge. An increasing body of literature from epidemiological and in vitro studies has demonstrated that arsenic is an immunotoxicant, but the mechanism driving arsenic-induced immunotoxicity is not well established. We have previously demonstrated that in human lymphoblastoid cell lines (LCLs), arsenic-induced cell death is strongly associated with the induction of autophagy. In this study we utilized genome-wide gene expression analysis and functional assays to characterize arsenic-induced effects in seven LCLs that were exposed to an environmentally relevant, minimally cytotoxic, concentration of arsenite (0.75 μM) over an eight-day time course. Arsenic exposure resulted in inhibition of cellular growth and induction of autophagy (measured by expansion of acidic vesicles) over the eight-day exposure duration. Gene expression analysis revealed that arsenic exposure increased global lysosomal gene expression, which was associated with increased functional activity of the lysosome protease, cathepsin D. The arsenic-induced expansion of the lysosomal compartment in LCL represents a novel target that may offer insight into the immunotoxic effects of arsenic.

  6. Methanol Extract of Adansonia digitata Leaf Protects Against Sodium Arsenite-induced Toxicities in Male Wistar Rats

    PubMed Central

    Adegoke, Ayodeji Mathias; Gbadegesin, Michael Adedapo; Odunola, Oyeronke Adunni

    2017-01-01

    Background: Human and animal population exposure to arsenic through the consumption of arsenic contaminated water is rampant in many parts of the world. Protective agents of medicinal plants origin could provide maximum protection against toxicities of various kinds. Objective: The protective role of orally administered methanol extract of the leaves of Adansonia digitata (MELAD) on sodium arsenite (SA) – induced clastogenicity and hepatotoxicity in male Wistar rats was evaluated. Materials and Methods: Thirty male Wistar rats divided into six Groups (1–6) of five animals each were used for the study. Group 1 (negative control) received distilled water and normal diet only, Groups 2–6 received the extract (at 250 or 500 mg/kg body weight) and/or SA at 2.5 mg/kg body weight. Results: There was statistically significant (P < 0.05) increase in the number of micronucleated polychromatic erythrocytes and lipid peroxidation in the SA group as compared with the negative control and treated groups. Administration of the extract reduced the effects of SA on the above parameters. Activities of serum alanine and aspartate aminotransferases did not show statistically significant effects; however, the histological analyses revealed periportal cellular infiltration by mononuclear cells, whereas the MELAD treated groups show mild cellular infiltration and mild portal congestion. Conclusions: MELAD protect against SA-induced toxicities in rats, and it may offer protection in circumstances of co-exposure and cases of arsenicosis. SUMMARY MELAD extract significantly reduce the lipid peroxidation induced by sodium arsenite in the liver of rats.MELAD did not show profound effects on the activities of serum alanine (ALT) and aspartate (AST) aminotranferases.MELAD offered significant protection against sodium arsenite-induced genotoxicity in the micronuclei induction assay.In the circumstances of co-exposure to arsenic contamination, MELAD may protect against sodium arsenite-induced

  7. Antioxidant potential of tea reduces arsenite induced oxidative stress in Swiss albino mice.

    PubMed

    Sinha, D; Roy, S; Roy, M

    2010-04-01

    Environmental arsenic (As) is a potent human carcinogen and groundwater As contamination is a major health concern in West Bengal, India. Oxidative stress has been one of the prime factors in As-induced carcinogenicity. Generation of reactive oxygen species (ROS), beyond the body's endogenous antioxidant balance cause a severe imbalance of the cellular antioxidant defence mechanism. Tea, a popular beverage has excellent chemopreventive and antioxidant properties. In this study it was investigated whether these flavonoids could ameliorate the arsenite (As III) induced oxidative stress in Swiss albino mice. Bio-monitoring with comet assay elicited that the increase in genotoxicity caused by As III was counteracted by both black tea and green tea. Elevated levels of lipid peroxides and protein carbonyl by As III were effectively reduced with green as well as black tea. They also exhibited protective action against the As III induced depletion of antioxidants like catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-S-transferase (GST) and glutathione (GSH) in mice liver tissue. Thus the tea polyphenols by virtue of their antioxidant potential may be used as an effective agent to reduce the As III induced oxidative stress in Swiss albino mice.

  8. Arsenite binding-induced zinc loss from PARP-1 is equivalent to zinc deficiency in reducing PARP-1 activity, leading to inhibition of DNA repair

    SciTech Connect

    Sun, Xi; Zhou, Xixi; Du, Libo; Liu, Wenlan; Liu, Yang; Hudson, Laurie G.; Liu, Ke Jian

    2014-01-15

    Inhibition of DNA repair is a recognized mechanism for arsenic enhancement of ultraviolet radiation-induced DNA damage and carcinogenesis. Poly(ADP-ribose) polymerase-1 (PARP-1), a zinc finger DNA repair protein, has been identified as a sensitive molecular target for arsenic. The zinc finger domains of PARP-1 protein function as a critical structure in DNA recognition and binding. Since cellular poly(ADP-ribosyl)ation capacity has been positively correlated with zinc status in cells, we hypothesize that arsenite binding-induced zinc loss from PARP-1 is equivalent to zinc deficiency in reducing PARP-1 activity, leading to inhibition of DNA repair. To test this hypothesis, we compared the effects of arsenite exposure with zinc deficiency, created by using the membrane-permeable zinc chelator TPEN, on 8-OHdG formation, PARP-1 activity and zinc binding to PARP-1 in HaCat cells. Our results show that arsenite exposure and zinc deficiency had similar effects on PARP-1 protein, whereas supplemental zinc reversed these effects. To investigate the molecular mechanism of zinc loss induced by arsenite, ICP-AES, near UV spectroscopy, fluorescence, and circular dichroism spectroscopy were utilized to examine arsenite binding and occupation of a peptide representing the first zinc finger of PARP-1. We found that arsenite binding as well as zinc loss altered the conformation of zinc finger structure which functionally leads to PARP-1 inhibition. These findings suggest that arsenite binding to PARP-1 protein created similar adverse biological effects as zinc deficiency, which establishes the molecular mechanism for zinc supplementation as a potentially effective treatment to reverse the detrimental outcomes of arsenic exposure. - Highlights: • Arsenite binding is equivalent to zinc deficiency in reducing PARP-1 function. • Zinc reverses arsenic inhibition of PARP-1 activity and enhancement of DNA damage. • Arsenite binding and zinc loss alter the conformation of zinc finger

  9. Effects of combined administration of captopril and DMSA on arsenite induced oxidative stress and blood and tissue arsenic concentration in rats.

    PubMed

    Kalia, Kiran; Narula, Gagan Deep; Kannan, G M; Flora, S J S

    2007-01-01

    We compared the therapeutic efficacy of captopril and a thiol chelating agent, meso 2,3-dimercaptosuccinic acid (DMSA) either individually or in combination against arsenite induced oxidative stress and mobilization of metal in rats. Animals were exposed to 100 ppm arsenite as sodium arsenite in drinking water for six weeks followed by treatment with DMSA (50 mg/kg, orally), captopril (50 mg/kg, intraperitoneally) either alone or in combination, once daily for 5 consecutive days. Arsenite exposure led to a significant depletion of blood delta-aminolevulinic acid dehydratase (ALAD) activity, glutathione and platelet levels while significantly increased the level of reactive oxygen species (in RBCs). Hepatic reduced glutathione (GSH) level showed a significant decrease while, thiobarbituric acid reactive substances (TBARS) levels increased on arsenite exposure indicating arsenite induced hepatic oxidative stress. Kidney GSH, GSSG, catalase and TBARS remained unchanged on arsenite exposure. Treatment with DMSA was effective in increasing ALAD activity while, captopril was ineffective when given alone. Captopril when co-administered with DMSA also provided no additional beneficial effect on blood ALAD activity but significant brought altered platelet counts back to the normal value. In contrast, administration of captopril alone provided significant beneficial effects on hepatic oxidative stress, and in combination with DMSA provided a more pronounced recovery in the TBARS level compared to the individual effect of DMSA and captopril. Renal biochemical variables remained insensitive to arsenite and any of the treatments. Interestingly, combined administration of captopril with DMSA had a remarkable effect in depleting total arsenic concentration from blood and soft tissues. These results lead us to conclude that captopril administration during chelation treatment had some beneficial effects particularly on the protection of inhibited blood ALAD activity, and depletion

  10. Sodium arsenite induced changes in survival, growth, metamorphosis and genotoxicity in the Indian cricket frog (Rana limnocharis).

    PubMed

    Singha, Utsab; Pandey, Neelam; Boro, Freeman; Giri, Sarbani; Giri, Anirudha; Biswas, Somava

    2014-10-01

    Arsenic contamination of the environment is a matter of great concern. Understanding the effects of arsenic on aquatic life will act as biological early warning system to assess how arsenic could shape the biodiversity in the affected areas. Rapid decline in amphibian population in recent decades is a cause of major concern. Over the years, amphibians have been recognized as excellent bio-indicators of environmental related stress. In the present study, we examined the toxic and genotoxic effects of sodium arsenite in the tadpoles of the Indian cricket frog (Rana limnocharis). Sodium arsenite at different concentrations (0, 50, 100, 200 and 400 μg L(-1)) neither induced lethality nor significantly altered body weight at metamorphosis. However, it accelerated the rate of metamorphosis at higher concentrations, reduced body size (snout-vent length) and induced developmental deformities such as loss of limbs. Besides, at concentration ranges between 100 and 400 μg L(-1), sodium arsenite induced statistically significant genotoxicity at 24, 48, 72 and 96 h of the exposure in a concentration-dependent manner. However, it did not show time effects as the highest frequency was found between 48 and 72 h which remained steady subsequently. The genotoxicity was confirmed by comet assay in the whole blood cells. These findings suggest that arsenic at environmentally relevant concentrations has significant sub-lethal effects on R.limnocharis, which may have long-term fitness consequence to the species and may have similar implications in other aquatic life too.

  11. Quantitative GFP fluorescence as an indicator of arsenite developmental toxicity in mosaic heat shock protein 70 transgenic zebrafish

    SciTech Connect

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

    2007-12-01

    In transgenic zebrafish (Danio rerio), green fluorescent protein (GFP) is a promising marker for environmental pollutants. In using GFP, one of the obstacles which we faced was how to compare toxicity among different toxicants or among a specific toxicant in different model species with the intensity of GFP expression. Using a fluorescence detection method, we first validated our method for estimating the amount of GFP fluorescence present in transgenic fish, which we used as an indicator of developmental toxicity caused by the well-known toxicant, arsenite. To this end, we developed mosaic transgenic zebrafish with the human heat shock response element (HSE) fused to the enhanced GFP (EGFP) reporter gene to indicate exposure to arsenite. We confirmed that EGFP expression sites correlate with gross morphological disruption caused by arsenite exposure. Arsenite (300.0 {mu}M) caused stronger EGFP fluorescence intensity and quantity than 50.0 {mu}M and 10.0 {mu}M arsenite in our transgenic zebrafish. Furthermore, arsenite-induced apoptosis was demonstrated by TUNEL assay. Apoptosis was inhibited by the antioxidant, N-acetyl-cystein (NAC) in this transgenic zebrafish. The distribution of TUNEL-positive cells in embryonic tissues was correlated with the sites of arsenite toxicity and EGFP expression. The EGFP values quantified using the standard curve equation from the known GFP quantity were consistent with the arsenite-induced EGFP expression pattern and arsenite concentration, indicating that this technique can be a reliable and applicable measurement. In conclusion, we propose that fluorescence-based EGFP quantification in transgenic fish containing the hsp70 promoter-EGFP reporter-gene construct is a useful indicator of development toxicity caused by arsenite.

  12. The mechanism of PDT-induced apoptosis

    NASA Astrophysics Data System (ADS)

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

    2003-12-01

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

  13. Methods for determining Myc-induced apoptosis.

    PubMed

    Lu, Dan; Littlewood, Trevor D

    2013-01-01

    Although many oncoproteins promote cell growth and proliferation, some also possess the potential to induce cell death by apoptosis. Deregulated expression of the myc oncogene promotes apoptosis in both cultured cells and in some tissues in vivo. Here we describe techniques to detect Myc-induced apoptosis in vitro using flow cytometry and microscopy and in vivo using immunohistochemical staining.

  14. Phytochelatin synthesis in Dunaliella salina induced by arsenite and arsenate under various phosphate regimes.

    PubMed

    Wang, Ya; Zhang, Chunhua; Zheng, Yanheng; Ge, Ying

    2017-02-01

    This study investigated the dynamic variations in thiol compounds, including cysteine (Cys), glutathione (GSH), and phytochelatins (PCs), in Dunaliella salina samples exposed to arsenite [As(III)] and arsenate [As(V)] under various phosphate (PO4(3-)) regimes. Our results showed that GSH was the major non-protein sulfhydryl compound in D. salina cells. As(III) and As(V) induced PC syntheses in D. salina. PC2, PC3, and PC4 were all found in algal cells; the PC concentrations decreased gradually while exposed to As for 3 d. The synthesis of PC2-3 was significantly affected by As(III) and As(V) concentrations in the cultures. More PCs were detected in the As(V)-treated algal cells compared with the As(III) treatment. PC levels increased with As(III)/As(V) amount in the medium, but remained stable after 112μgL(-1) As(V) exposure. In contrast, significant (p<0.001) positive correlations were observed between PC synthesis and intracellular As(III) content or As accumulation in As(III)-treated algal cells during the 72-h exposure. PO4(3-) had a significant influence on the PC synthesis in algal cells, irrespective of the As-treated species. Reductions in As uptake and subsequent PC synthesis by D. salina were observed as the PO4(3-) concentration in the growth medium increased. L-Buthionine sulfoximine (BSO) differentially influenced PC synthesis in As-treated D. salina under different extracellular PO4(3-) regimes. Overall, our data demonstrated that the production of GSH and PCs was affected by PO4(3-) and that these thiols played an important role in As detoxification by D. salina.

  15. Arsenite-induced stress granule formation is inhibited by elevated levels of reduced glutathione in West Nile virus-infected cells

    PubMed Central

    Basu, Mausumi; Courtney, Sean C.

    2017-01-01

    Oxidative stress activates the cellular kinase HRI, which then phosphorylates eIF2α, resulting in stalled translation initiation and the formation of stress granules (SGs). SG assembly redirects cellular translation to stress response mRNAs and inhibits cap-dependent viral RNA translation. Flavivirus infections were previously reported to induce oxidative stress in infected cells but flavivirus-infected cells paradoxically develop resistance to arsenite (Ars)-induced SG formation with time after infection. This resistance was previously postulated to be due to sequestration of the SG protein Caprin1 by Japanese encephalitis virus capsid protein. However, Caprin1 did not co-localize with West Nile virus (WNV) capsid protein in infected cells. Other stressors induced SGs with equal efficiency in mock- and WNV-infected cells indicating the intrinsic ability of cells to assemble SGs was not disabled. Induction of both reactive oxygen species (ROS) and the antioxidant response was detected at early times after WNV-infection. The transcription factors, Nrf2 and ATF4, which activate antioxidant genes, were upregulated and translocated to the nucleus. Knockdown of Nrf2, ATF4 or apoptosis-inducing factor (AIF), a mitochondrial protein involved in regenerating intracellular reduced glutathione (GSH) levels, with siRNA or treatment of cells with buthionine sulphoximine, which induces oxidative stress by inhibiting GSH synthesis, decreased intracellular GSH levels and increased the number of SG-positive, infected cells. Mitochondria were protected from Ars-induced damage by WNV infection until late times in the infection cycle. The results indicate that the increase in virus-induced ROS levels is counterbalanced by a virus-induced antioxidant response that is sufficient to also overcome the increase in ROS induced by Ars treatment and prevent Ars-induced SG assembly and mitochondrial damage. The virus-induced alterations in the cellular redox status appear to provide benefits

  16. Sodium arsenite-induced inhibition of cell proliferation is related to inhibition of IL-2 mRNA expression in mouse activated T cells.

    PubMed

    Conde, Patricia; Acosta-Saavedra, Leonor C; Goytia-Acevedo, Raquel C; Calderon-Aranda, Emma S

    2007-04-01

    A proposed mechanism for the As-induced inhibition of cell proliferation is the inhibition of IL-2 secretion. However, the effects of arsenite on IL-2 mRNA expression or on the ERK pathway in activated-T cells have not yet been described. We examined the effect of arsenite on IL-2 mRNA expression, cell activation and proliferation in PHA-stimulated murine lymphocytes. Arsenite (1 and 10 microM) decreased IL-2 mRNA expression, IL-2 secretion and cell proliferation. Arsenite (10 microM) strongly inhibited ERK-phosphorylation. However, the partial inhibition (50%) of IL-2 mRNA produced by 1 microM, consistent with the effects on IL-2 secretion and cell proliferation, could not be explained by the inhibition of ERK-phosphorylation, which was not affected at this concentration. The inhibition of IL-2 mRNA expression caused by 1 microM could be associated to effects on pathways located downstream or parallel to ERK. Arsenite also decreased early activation (surface CD69+ expression) in both CD4+ and CD8+, and decreased total CD8+ count without significantly affecting CD4+, supporting that the cellular immune response mediated by cytotoxic T cells is an arsenic target. Thus, our results suggest that arsenite decreases IL-2 mRNA levels and T-cell activation and proliferation. However, further studies on the effects of arsenite on IL-2 gene transcription and IL-2 mRNA stability are needed.

  17. Nitric oxide and calcium ions in apoptotic esophageal carcinoma cells induced by arsenite

    PubMed Central

    Shen, Zhong-Ying; Shen, Wen-Ying; Chen, Ming-Hua; Shen, Jian; Cai, Wei-Jie; Yi, Zeng

    2002-01-01

    AIM: To Quantitatively analyze the nitri oxide (NO) and Ca2+ in apoptosis of esophageal carcinoma cells induced by arsenic trioxide (As2O3). METHODS: The cell line SHEEC1, a malignant esophageal epithelial cell induced by HPV in synergy with TPA in our laboratory, was cultured in a serum-free medium and treated with As2O3. Before and after administration of As2O3, NO production in cultured medium was detected quantitatively using the Griess Colorimetric method. Intracellular Ca2+ was labeled by using the fluorescent dye Fluo3-AM and detected under confocal laser scanning microscope (CLSM), which was able to acquire data in real-time enabling Ca2+ dynamics of individual cells in vitro. The apoptotic cells were examined under electron microscopy. RESULTS: Intracellular concentration of Ca2+ increased from 1.00 units to 1.09-1.38 units of fluorescent intensity at As2O3 treatment and NO products subsequently released from As2O3-treated cells increased from 0.98-1.00 × 10-2 μmol·L-1 up to 1.48-1.52 × 10-2 μmol·L-1 and maintained in a high level continuously. Finally apoptosis of cells occurred, chromatin being agglutinated, cells shrunk, nuclei became round and mitochondria swelled. CONCLUSION: Ca2+ and NO increased with cell damage and apoptosis in cells treated by As2O3. The Ca2+ is an initial messenger to the apoptotic pathway. To investigate Ca2+ and NO will be a new direction for studying the apoptotic signaling messenger of the esophageal carcinoma cells induced by As2O3. PMID:11833068

  18. Sodium arsenite-induced stress-related gene expression in normal human epidermal, HaCaT, and HEL30 keratinocytes.

    PubMed Central

    Trouba, Kevin J; Geisenhoffer, Kristen M; Germolec, Dori R

    2002-01-01

    Arsenic is a carcinogen that poses a significant health risk in humans. Based on evidence that arsenic has differential effects on human, rodent, normal, and transformed cells, these studies addressed the relative merits of using normal human epidermal keratinocytes (NHEK) and immortalized human (HaCaT) and mouse (HEL30) keratinocytes when examining stress-induced gene expression that may contribute to carcinogenesis. We hypothesize that redox-related gene expression is differentially modulated by arsenic in normal versus immortalized keratinocytes. To test the hypothesis, we exposed keratinocytes to sodium arsenite for 4 or 24 hr, at which time serine threonine kinase-25 (stk25) and nicotine adenine dinucleotide phosphate [nad(p)h] quinone oxidoreductase gene expression were measured. The effect of glutathione reduction on arsenite-induced cytotoxicity and gene expression in NHEK also was evaluated by addition of l-buthionine-[S,R]-sulfoximine (BSO) to culture media. Results indicate the term LC(50) for arsenite is approximately 10-15 microM in NHEK and HEL30 keratinocytes and 30 microM in HaCaT keratinocytes. Compared with HaCaT and HEL30 keratinocytes, a nontoxic concentration of arsenite (2.5 microM) increases stk25 and nad(p)h quinone oxidoreductase gene expression in NHEK, an effect partially attenuated by BSO. These data indicate that NHEK and HaCaT/HEL30 keratinocytes have similar sensitivities toward arsenite-induced cytotoxicity but unique gene expression responses. They also suggest that arsenite modulates gene expression in NHEK involved in cellular signaling and other aspects of intermediary metabolism that may contribute to the carcinogenic process. PMID:12426128

  19. Local anesthetics induce human renal cell apoptosis.

    PubMed

    Lee, H Thomas; Xu, Hua; Siegel, Cory D; Krichevsky, Igor E

    2003-01-01

    Renal cell apoptosis contributes significantly to the pathogenesis of acute renal failure. Local anesthetics induce apoptosis in neuronal and lymphocytic cell lines. We examined the effects of chronic (48 h) local anesthetic treatment (lidocaine, bupivacaine and tetracaine) on human proximal tubular (HK-2) cells. Apoptosis induction was assessed by detecting poly(ADP)-ribose polymerase fragmentation, caspase activation, terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL) staining, DNA laddering and by cellular morphology. Cell death was quantified by measuring neutral red dye uptake and lactate dehydrogenase released into the cell culture medium. All 3 local anesthetics caused concentration-dependent cell death, induced HK-2 cell apoptosis and potentiated TNF-alpha induced apoptosis. Local anesthetics induced HK-2 cell apoptosis by activation of caspases 3, 6, 7, 8 and 9. ZVAD-fmk, a pan-caspase inhibitor, blocked the local anesthetic induced HK-2 cell apoptosis. Local anesthetics also inhibited the activities of anti-apoptotic kinases protein kinase B (Akt) and extracellular signal regulated mitrogen-activated protein kinase. Local anesthetic's pro-apoptotic effects are independent of sodium channel inhibition as tetrodotoxin, a selective voltage-gated sodium channel blocker, failed to mimic local anesthetic-mediated induction or potentiation of HK-2 cell apoptosis. We conclude that local anesthetics induce human renal cell apoptotic signaling by caspase activation and via inhibition of pro-survival signaling pathways.

  20. p27 suppresses arsenite-induced Hsp27/Hsp70 expression through inhibiting JNK2/c-Jun- and HSF-1-dependent pathways.

    PubMed

    Liu, Jinyi; Zhang, Dongyun; Mi, Xiaoyi; Xia, Qing; Yu, Yonghui; Zuo, Zhenghong; Guo, Wei; Zhao, Xuewei; Cao, Jia; Yang, Qing; Zhu, Angela; Yang, Wancai; Shi, Xianglin; Li, Jingxia; Huang, Chuanshu

    2010-08-20

    p27 is an atypical tumor suppressor that can regulate the activity of cyclin-dependent kinases and G(0)-to-S phase transitions. More recent studies reveal that p27 may also exhibit its tumor-suppressive function through regulating many other essential cellular events. However, the molecular mechanisms underlying these anticancer effects of p27 are largely unknown. In this study, we found that depletion of p27 expression by either gene knock-out or knockdown approaches resulted in up-regulation of both Hsp27 and Hsp70 expression at mRNA- and promoter-derived transcription as well as protein levels upon arsenite exposure, indicating that p27 provides a negative signal for regulating the expression of Hsp27 and Hsp70. Consistently, arsenite-induced activation of JNK2/c-Jun and HSF-1 pathways was also markedly elevated in p27 knock-out (p27(-/-)) and knockdown (p27 shRNA) cells. Moreover, interference with the expression or function of JNK2, c-Jun, and HSF-1, but not JNK1, led to dramatic inhibition of arsenite-induced Hsp27 and Hsp70 expression. Collectively, our results demonstrate that p27 suppresses Hsp27 and Hsp70 expression at the transcriptional level specifically through JNK2/c-Jun- and HSF-1-dependent pathways upon arsenite exposure, which provides additional important molecular mechanisms for the tumor-suppressive function of p27.

  1. EFFECTS OF ARSENITE IN TELOMERE AND TELOMERASE IN RELATION TO CELL PROLIFERATION AND APOPTOSIS IN HUMAN KERATINOCYTES AND LEUKEMIA CELLS IN VITRO

    EPA Science Inventory

    Telomeres are critical in maintaining chromosome and genomic stability. Arsenic, a human carcinogen as well as an anticancer agent, is known for its clastogenicity. To better understand molecular mechanisms of arsenic actions, we investigated arsenite effects on telomere and telo...

  2. Curcumin Protects Human Keratinocytes against Inorganic Arsenite-Induced Acute Cytotoxicity through an NRF2-Dependent Mechanism

    PubMed Central

    Zhao, Rui; Yang, Bei; Wang, Linlin; Xue, Peng; Deng, Baocheng; Zhang, Guohua; Jiang, Shukun; Zhang, Miao; Liu, Min; Pi, Jingbo; Guan, Dawei

    2013-01-01

    Human exposure to inorganic arsenic leads to various dermal disorders, including hyperkeratosis and skin cancer. Curcumin is demonstrated to induce remarkable antioxidant activity in a variety of cells and tissues. The present study aimed at identifying curcumin as a potent activator of nuclear factor erythroid 2-related factor 2 (NRF2) and demonstrating its protective effect against inorganic arsenite- (iAs3+-) induced cytotoxicity in human keratinocytes. We found that curcumin led to nuclear accumulation of NRF2 protein and increased the expression of antioxidant response element- (ARE-) regulated genes in HaCaT keratinocytes in concentration- and time-dependent manners. High concentration of curcumin (20 μM) also increased protein expression of long isoforms of NRF1. Treatment with low concentrations of curcumin (2.5 or 5 μM) effectively increased the viability and survival of HaCaT cells against iAs3+-induced cytotoxicity as assessed by the MTT assay and flow cytometry and also attenuated iAs3+-induced expression of cleaved caspase-3 and cleaved PARP protein. Selective knockdown of NRF2 or KEAP1 by lentiviral shRNAs significantly diminished the cytoprotection conferred by curcumin, suggesting that the protection against iAs3+-induced cytotoxicity is dependent on the activation of NRF2. Our results provided a proof of the concept of using curcumin to activate the NRF2 pathway to alleviate arsenic-induced dermal damage. PMID:23710286

  3. Delphinidin induces cytotoxicity and potentiates cytocidal effect in combination with arsenite in an acute promyelocytic leukemia NB4 cell line.

    PubMed

    Yuan, Bo; Okusumi, Saki; Yoshino, Yuta; Moriyama, Chihiro; Tanaka, Sachiko; Hirano, Toshihiko; Takagi, Norio; Toyoda, Hiroo

    2015-07-01

    The effects of delphinidin were investigated by focusing on growth inhibition, cell cycle arrest and apoptosis induction in the human acute promyelocytic leukemia (APL) NB4 cell line. Delphinidin exhibited a dose- and time-dependent cytotoxic effect against NB4 cells. Almost no cell cycle arrest, but an apparent increase in the percentage of sub-G1 cells was observed in delphinidin-treated cells. The activation of caspase-8 and -9 was observed as early as 1-h post-exposure to delphinidin, followed by the activation of caspase-3 from 3-h post-exposure. A substantial decrease in the expression level of Bid was also observed as early as 1-h post-exposure. A modest decrease in the mitochondrial membrane potential (ΔΨm) was observed at 3-h post-exposure, followed by a substantial time-dependent decrease in ΔΨm in treated cells. Delphinidin exerted more potent cytotoxicity against NB4 cells than normal peripheral blood mononuclear cells (PBMNCs). In addition, delphinidin in combination with an arsenic derivative arsenite (As(III)), which has demonstrated marked efficacy in patients with APL, achieved an enhanced cytocidal effect against NB4 cells, but lesser on PBMNCs. Treatment of NB4 cells with As(III) plus delphinidin did not increase, but decreased slightly, intracellular arsenic accumulation (As[i]) as compared to that treated with As(III) alone. These results suggested that delphinidin selectively sensitized NB4 cells to As(III), resulting in the enhancement of As(III) cytotoxicity by strengthening intrinsic/extrinsic pathway-mediated apoptosis induction, rather than affecting the As[i] levels. These observations may offer a rationale for the use of delphinidin to improve the clinical efficacy of As(III).

  4. Phytosphingosine induced mitochondria-involved apoptosis.

    PubMed

    Nagahara, Yukitoshi; Shinomiya, Takahisa; Kuroda, Sachiko; Kaneko, Naoki; Nishio, Reiji; Ikekita, Masahiko

    2005-02-01

    Sphingolipids are putative intracellular signal mediators in cell differentiation, growth inhibition, and apoptosis. Sphingosine, sphinganine, and phytosphingosine are structural analogs of sphingolipids and are classified as long-chain sphingoid bases. Sphingosine and sphinganine are known to play important roles in apoptosis. In the present study, we examined the phytosphingosine-induced apoptosis mechanism, focusing on mitochondria in human T-cell lymphoma Jurkat cells. Phytosphingosine significantly induced chromatin DNA fragmentation, which is a hallmark of apoptosis. Enzymatic activity measurements of caspases revealed that caspase-3 and caspase-9 are activated in phytosphingosine-induced apoptosis, but there is little activation of caspase-8 suggesting that phytosphingosine influences mitochondrial functions. In agreement with this hypothesis, a decrease in DeltaPsi(m) and the release of cytochrome c to the cytosol were observed upon phytosphingosine treatment. Furthermore, overexpression of mitochondria-localized anti-apoptotic protein Bcl-2 prevented phytosphingosine apoptotic stimuli. Western blot assays revealed that phytosphingosine decreases phosphorylated Akt and p70S6k. Dephosphorylation of Akt was partially inhibited by protein phosphatase inhibitor OA and OA attenuated phytosphingosine-induced apoptosis. Moreover, using a cell-free system, phytosphingosine directly reduced DeltaPsi(m). These results indicate that phytosphingosine perturbs mitochondria both directly and indirectly to induce apoptosis.

  5. Modulation of gene-expression profiles associated with sodium arsenite-induced cardiotoxicity by p-coumaric acid, a common dietary polyphenol.

    PubMed

    Prasanna, Nagalakshmi; Rasool, Mahaboobkhan

    2014-04-01

    In the present study, the purpose was to investigate the effect of p-coumaric acid on the mRNA-expression levels of inflammatory cytokines, transcription factor, MAP kinases, and apoptotic proteins by real time reverse transcription polymerase chain reaction in the cardiac tissue of sodium arsenite exposed rats. Sodium arsenite administration (5 mg/kg/b.wt, once daily for 30 days) upregulated the mRNA-expression levels of inflammatory cytokines (interleukin-1 beta, interleukin-6, tumor necrosis factor-alpha, and tumor growth factor-beta), transcription factor (NF-Kb-Rel A), protein kinases (Janus kinase and p38), caspase 3, and proapoptotic protein Bax in the cardiac tissue of rats, but the antiapoptotic protein Bcl-2 mRNA expression was found be downregulated. However, p-coumaric acid (75, 100 mg/kg/b. wt. oral) pretreatment daily before the sodium arsenite exposure protected the changes in the above mRNA-expression profiles observed in the cardiac tissues. In conclusion, this study confirmed that p-coumaric acid could be a promising dietary agent for protecting against the sodium arsenite-induced cardiotoxicity.

  6. DPI induces mitochondrial superoxide-mediated apoptosis.

    PubMed

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

    2003-02-15

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

  7. Protective effects of the dietary supplementation of turmeric (Curcuma longa L.) on sodium arsenite-induced biochemical perturbation in mice.

    PubMed

    Karim, Md Rezaul; Haque, Abedul; Islam, Khairul; Ali, Nurshad; Salam, Kazi Abdus; Saud, Zahangir Alam; Hossain, Ekhtear; Fajol, Abul; Akhand, Anwarul Azim; Himeno, Seiichiro; Hossain, Khaled

    2010-12-01

    The present study was undertaken to evaluate the protective effect of turmeric powder on arsenic toxicity through mice model. Swiss albino male mice were divided into four groups. The first group was used as control, while groups 2, 3, and 4 were treated with turmeric powder (T, 50 mg/kg body weight/day), sodium arsenite (Sa, 10 mg/kg body weight/day) and turmeric plus Sa (T+Sa), respectively. Results showed that oral administration of Sa reduced the weight gain of the mice compared to the control group and food supplementation of turmeric prevented the reduction of weight gain. Turmeric abrogated the Sa-induced elevation of serum urea, glucose, triglyceride (TG) level and alanine aminotransferase (ALT) activity except the activity of alkaline phosphatase (ALP). Turmeric also prevented the Sa-induced perturbation of serum butyryl cholinesterase activity (BChE). Therefore, ameliorating effect of turmeric on Sa-treated mice suggested the future application of turmeric to reduce or to prevent arsenic toxicity in human.

  8. BRCA2-dependent homologous recombination is required for repair of Arsenite-induced replication lesions in mammalian cells

    PubMed Central

    Ying, Songmin; Myers, Katie; Bottomley, Sarah; Helleday, Thomas; Bryant, Helen E.

    2009-01-01

    Arsenic exposure constitutes one of the most widespread environmental carcinogens, and is associated with increased risk of many different types of cancers. Here we report that arsenite (As[III]) can induce both replication-dependent DNA double-strand breaks (DSB) and homologous recombination (HR) at doses as low as 5 µM (0.65 mg/l), which are within the typical doses often found in drinking water in contaminated areas. We show that the production of DSBs is dependent on active replication and is likely to be the result of conversion of a DNA single-strand break (SSB) into a toxic DSB when encountered by a replication fork. We demonstrate that HR is required for the repair of these breaks and show that a functional HR pathway protects against As[III]-induced cytotoxicity. In addition, BRCA2-deficient cells are sensitive to As[III] and we suggest that As[III] could be exploited as a therapy for HR-deficient tumours such as BRCA1 and BRCA2 mutated breast and ovarian cancers. PMID:19553191

  9. Sodium nitroprusside induces apoptosis of rabbit chondrocytes

    NASA Astrophysics Data System (ADS)

    Liang, Qian; Wang, Xiao-Ping; Chen, Tong-Sheng

    2013-02-01

    Osteoarthritis (OA) is characterized by a slowly progressing degradation of the matrix and destruction of articular cartilage. Apoptosis of chondrocyte is accounted for the mechanism of OA. Nitric oxide (NO), as a stimulus, has been shown to induce chondrocyte apoptosis by activating the matrix metalloproteinases (MMPs), increasing the expression of cyclooxygenase 2 (COX-2) and the level of prostaglandin E2 (PGE2), inhibiting the proteoglycan synthesis and type II collagen expression. In this study, sodium nitroprusside (SNP) was administered to be the NO donor to explore the mechanism of NO-induced apoptosis of rabbit chondrocytes obtained from six weeks old New Zealand rabbits. CCK-8 assay revealed the inhibitory effect of SNP on cell viability. We used flow cytometry (FCM) to assess the form of cell death by Annexin-V/propidium iodide (PI) double staining, and evaluate the change of mitochondrial membrane potential (ΔΨm). We found that the SNP induced chondrocyte apoptosis in a dose- and time-dependent manner and an observable reduction of ΔΨm. In conclusion, our findings indicate that SNP induces apoptosis of rabbit chondrocytes via a mitochondria-mediated pathway.

  10. Arsenic and fluoride induce neural progenitor cell apoptosis.

    PubMed

    Rocha, R A; Gimeno-Alcañiz, J V; Martín-Ibañez, R; Canals, J M; Vélez, D; Devesa, V

    2011-06-24

    The aim of the present study is to determine the effect of inorganic arsenic (As) and its metabolites on the viability of the neural progenitor cell (NPC) line C17.2, in order to evaluate cellular mechanisms involved in As developmental neurotoxicity. Moreover, we analyzed the effects of the coexposure to As and fluoride (F), a situation to which some populations are commonly exposed. Our results show that NPCs are not susceptible to pentavalent As species [arsenate, monomethylarsonic acid, and dimethylarsinic acid] and F alone. However, the trivalent metabolites of arsenate [arsenite, monomethylarsonous acid, and dimethylarsinous acid] are toxic at concentrations below 1 mg/l, and this susceptibility increases when there is coexposure with F (≥ 5 mg/l). Arsenite triggers apoptosis after 24 h of exposure, whereas monomethylarsonous acid produces necrosis at very short times (2 h). Arsenite leads to an increase in intracellular Ca levels and generation of reactive oxygen species, which may cause a decrease in mitochondrial transmembrane potential, release of cytochrome c, and consequent activation of caspases. A slight activation of calpain also takes place, which might favor activation of the mitochondrial pathway or might activate other pathways. The treatment with some antioxidants such as quercetin and α-tocopherol shows only a partial reduction of the cytotoxicity.

  11. Differential sensitivities of bone marrow, spleen and thymus to genotoxicity induced by environmentally relevant concentrations of arsenite.

    PubMed

    Xu, Huan; McClain, Shea; Medina, Sebastian; Lauer, Fredine T; Douillet, Christelle; Liu, Ke Jian; Hudson, Laurie G; Stýblo, Miroslav; Burchiel, Scott W

    2016-11-16

    It is known in humans and mouse models, that drinking water exposures to arsenite (As(+3)) leads to immunotoxicity. Previously, our group showed that certain types of immune cells are extremely sensitive to arsenic induced genotoxicity. In order to see if cells from different immune organs have differential sensitivities to As(+3), and if the sensitivities correlate with the intracellular concentrations of arsenic species, male C57BL/6J mice were dosed with 0, 100 and 500ppb As(+3)via drinking water for 30d. Oxidation State Specific Hydride Generation- Cryotrapping- Inductively Coupled Plasma- Mass Spectrometry (HG- CT- ICP- MS) was applied to analyze the intracellular arsenic species and concentrations in bone marrow, spleen and thymus cells isolated from the exposed mice. A dose-dependent increase in intracellular monomethylarsonous acid (MMA(+3)) was observed in both bone marrow and thymus cells, but not spleen cells. The total arsenic and MMA(+3) levels were correlated with an increase in DNA damage in bone marrow and thymus cells. An in vitro treatment of 5, 50 and 500nM As(+3) and MMA(+3) revealed that bone marrow cells are most sensitive to As(+3) treatment, and MMA(+3) is more genotoxic than As(+3). These results suggest that the differential sensitivities of the three immune organs to As(+3) exposure are due to the different intracellular arsenic species and concentrations, and that MMA(+3) may play a critical role in immunotoxicity.

  12. Molecular mechanisms of UV-induced apoptosis.

    PubMed

    Kulms, D; Schwarz, T

    2000-10-01

    Sunburn cells, single standing cells with typical morphologic features occurring in UV-exposed skin, have been recognized as keratinocytes undergoing apoptosis following UV irradiation. Induction of apoptosis following UV exposure appears to be a protective mechanism, getting rid off severely damaged cells that bear the risk of malignant transformation. UV-mediated apoptosis is a highly complex process in which different molecular pathways are involved. These include DNA damage, activation of the tumor suppressor gene p53, triggering of cell death receptors either directly by UV or by autocrine release of death ligands, mitochondrial damage and cytochrome C release. Detailed knowledge about the interplay between these pathways will increase our understanding of photocarcinogenesis. This review briefly discusses recent findings concerning the molecular mechanisms underlying UV-induced apoptosis.

  13. Modulatory role of Acacia honey from north-west Nigeria on sodium arsenite-induced clastogenicity and oxidative stress in male Wistar rats.

    PubMed

    Muhammad, Aliyu; Odunola, Oyeronke A; Gbadegesin, Michael A; Adegoke, Ayodeji M; Olugbami, J Olorunjuwon; Uche, Ndidi S

    2015-01-01

    Effect of Acacia honey from north-west Nigeria on sodium arsenite-induced oxidative damage and clastogenicity in male Wistar rats was investigated. Animals were divided into four groups and were treated daily via oral gavage for one week before they were sacrificed. Brain, liver and blood serum were collected for antioxidant and protein assays. Clastogenicity, in vitro antioxidant activity, vitamins and minerals were also evaluated. From the results, co-administration of Acacia honey with sodium arsenite on the animals increased (P < 0.05) glutathione peroxidase, superoxide dismutase and catalase activities with concomitant decrease in malondialdehyde levels and anti-clastogenic effects relative to the group treated with sodium arsenite only. The honey possesses reducing power, high hydrogen peroxide scavenging activity, good amount of vitamins (A, C and E), flavonoids (5.08 ± 0.92 mg QE/100 g) and phenolics (5.40 ± 0.69 mg GAE/100 g). The minerals present include zinc, iron, sodium, magnesium, potassium and calcium. In conclusion, Acacia honey from Nigeria may mitigate oxidative stress and clastogenicity.

  14. Noscapine induces apoptosis in human glioma cells by an apoptosis-inducing factor-dependent pathway.

    PubMed

    Newcomb, Elizabeth W; Lukyanov, Yevgeniy; Smirnova, Iva; Schnee, Tona; Zagzag, David

    2008-07-01

    Previously, we identified noscapine as a small molecule inhibitor of the hypoxia-inducible factor-1 pathway in hypoxic human glioma cells and human umbilical vein endothelial cells. Noscapine is a nontoxic ingredient in cough medicine currently used in clinical trials for patients with non-Hodgkin's lymphoma or chronic lymphocytic leukemia to assess antitumor efficacy. Here, we have evaluated the sensitivity of four human glioma cell lines to noscapine-induced apoptosis. Noscapine was a potent inhibitor of proliferation and inducer of apoptosis. Induction of apoptosis was associated with activation of the c-jun N-terminal kinase signaling pathway concomitant with inactivation of the extracellular signal regulated kinase signaling pathway and phosphorylation of the antiapoptotic protein Bcl-2. Noscapine-induced apoptosis was associated with the release of mitochondrial proteins apoptosis-inducing factor (AIF) and/or cytochrome c. In some glioma cell lines, only AIF release occurred without cytochrome c release or poly (ADP-ribose) polymerase cleavage. Knock-down of AIF decreased noscapine-induced apoptosis. Our results suggest the potential importance of noscapine as a novel agent for use in patients with glioblastoma owing to its low toxicity profile and its potent anticancer activity.

  15. Editor's Highlight: Interactive Genotoxicity Induced by Environmentally Relevant Concentrations of Benzo(a)Pyrene Metabolites and Arsenite in Mouse Thymus Cells.

    PubMed

    Xu, Huan; Lauer, Fredine T; Liu, Ke Jian; Hudson, Laurie G; Burchiel, Scott W

    2016-11-01

    Arsenic and polycyclic aromatic hydrocarbon (PAH) exposures affect many people worldwide leading to cancer and other diseases. Arsenite (As(+3)) and certain PAHs are known to cause genotoxicity. However, there is limited information on the interactions between As(+3) and PAHs at environmentally relevant concentrations. The thymus is the primary immune organ for T cell development in mammals. Our previous studies showed that environmentally relevant concentrations of As(+3) induce genotoxicity in mouse thymus cells through Poly(ADP-ribose) polymerase (PARP) inhibition. Certain PAHs, such as the metabolites of benzo(a)pyrene (BaP), are known to cause DNA damage by forming DNA adducts. In the present study, primary mouse thymus cells were examined for DNA damage following 18 hr in vitro treatments with 5 or 50 nM As(+3) and 100 nM BaP, benzo[a]pyrene-7,8-dihydrodiol (BP-Diol), or benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE). An interactive increase in genotoxicity and apoptosis were observed following treatments with 5 nM As (+)  (3 )+( )100 nM BP-diol and 50 nM As (+)  (3 )+( )100 nM BPDE. We attribute the increase in DNA damage to inhibition of PARP inhibition leading to decreased DNA repair. To further support this hypothesis, we found that a PARP inhibitor, 3,4-dihydro-5[4-(1-piperindinyl) butoxyl]-1(2H)-isoquinoline (DPQ), also interacted with BP-diol to produce an increase in DNA damage. Interestingly, we also found that As(+3) and BP-diol increased CYP1A1 and CYP1B1 expression, suggesting that increased PAH metabolism may also contribute to genotoxicity. In summary, these results show that the suppression of PARP activity and induction of CYP1A1/CYP1B1 may act together to increase DNA damage produced by As(+3) and PAHs.

  16. Lithium protects ethanol-induced neuronal apoptosis

    SciTech Connect

    Zhong Jin . E-mail: jizhong@iupui.edu; Yang Xianlin; Yao Weiguo; Lee Weihua

    2006-12-01

    Lithium is widely used for the treatment of bipolar disorder. Recent studies have demonstrated its neuroprotective effect. Ethanol is a potent neurotoxin that is particularly harmful to the developing nervous system. In this study, we evaluated lithium's neuroprotection against ethanol-induced apoptosis. Transient exposure of infant mice to ethanol caused apoptotic cell death in brain, which was prevented significantly by administering a low dose of lithium 15 min later. In cultured cerebellar granule neurons, ethanol-induced apoptosis and activation of caspase-3/9, both of which were prevented by lithium. However, lithium's protection is not mediated by its commonly known inhibition of glycogen synthase3{beta}, because neither ethanol nor lithium has significant effects on the phosphorylation of Akt (ser473) or GSK3{beta} (ser9). In addition, the selective GSK-3{beta} inhibitor SB-415286 was unable to prevent ethanol-induced apoptosis. These data suggest lithium may be used as a potential preventive measure for ethanol-induced neurological deficits.

  17. EFFECTS OF HEAT SHOCK PROTEIN 70 (HSP70) ON ARSENITE INDUCED GENOTOXICITY

    EPA Science Inventory

    Arsenic (As), a human carcinogen, is known to be genotoxic although its mechanism(s) of action for tumorigenesis is not well understood. Among the toxicity-related properties of this chemical are its clastogenic and aneugenic activities, as well as its capacity for inducing stres...

  18. Effect of dietary co-administration of sodium selenite on sodium arsenite-induced ovarian and uterine disorders in mature albino rats.

    PubMed

    Chattopadhyay, Sandip; Pal Ghosh, Sampa; Ghosh, Debidas; Debnath, Jogen

    2003-10-01

    The subchronic treatment of mature female Wistar-strain albino rats in diestrous phase with sodium arsenite at a dose of 0.4 ppm/100 g body weight/rat/day via drinking water for period of 28 days (seven estrous cycles) caused a significant reduction in the plasma levels of leutinizing hormone (LH), follicle-stimulating hormone (FSH), and estradiol along with a significant decrease in ovarian activities of delta five, 3 beta-hydroxysteroid dehydrogenase (Delta5,3beta-HSD), and 17 beta-hydroxysteroid dehydrogenase (17beta-HSD) followed by a reduction in ovarian and uterine peroxidase activities. A significant weight loss of the ovary and uterus was also observed after this treatment, along with a prolonged diestrous phase and a high accumulation of arsenic in the plasma and these organs. Moreover, sodium arsenite was also responsible for ovarian follicular and uterine cell degeneration characterized by a high number of regressing follicles and a reduction in the uterine luminal diameter, respectively, in comparison with the controls. A dietary supplementation of sodium selenite at the dose of 0.6 mg/100 g body weight/rat/day for a period of 28 days along with arsenic treatment minimized the gonadal weight loss significantly and increased the activities of the ovarian steroidogenic enzymes as well as the ovarian and uterine peroxidase at the control level. Selenium was also able to increase the plasma levels of LH, FSH, and estradiol toward the control level. Vaginal smears showed normal estrous cyclicity in sodium selenite-supplemented arsenic-treated rats along with lower arsenic levels in the plasma and gonadal tissue in comparison with arsenic-only-treated rats. Histological sections of ovary and uterine tissues in the control and experimental groups confirmed that sodium selenite supplementation was able to prevent arsenic-induced histopathological changes in the ovary and uterus. Plasma levels of norepinephrine and dopamine in the midbrain and diencephalon

  19. Statin-induced apoptosis and skeletal myopathy.

    PubMed

    Dirks, Amie J; Jones, Kimberly M

    2006-12-01

    Over 100 million prescriptions were filled for statins (3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors) in 2004. Statins were originally developed to lower plasma cholesterol in patients with hypercholesterolemia and are the most effective drugs on the market in doing so. Because of the discovered pleiotropic effects of statins, the use has expanded to the treatment of many other conditions, including ventricular arrythmias, idiopathic dilated cardiomyopathy, cancer, osteoporosis, and diabetes. The elderly population is growing. Therefore, it is estimated that the number of statin users will also increase. Fortunately, the use of statins is relatively safe with few side effects. Myopathy is the most common side effect with symptoms ranging from fatigue, weakness, and pain to symptoms associated with rhabdomyolysis which is a life-threatening condition. The development of statin-induced rhabdomyolysis is rare occurring in approximately 0.1% of patients; however, the occurrence of less severe symptoms is underreported and may be 1-5% or more. Physical exercise appears to increase the likelihood for the development of myopathy in patients taking statins. It is thought that as many as 25% of statin users who exercise may experience muscle fatigue, weakness, aches, and cramping due to statin therapy and potentially dismissed by the patient and physician. The mechanisms causing statin-induced myopathy have not been elucidated; however, research efforts suggest that apoptosis of myofibers may contribute. The mitochondrion is considered a regulatory center of apoptosis, and therefore its role in the induction of apoptosis will be discussed as well as the mechanism of statin-induced apoptosis and myopathy.

  20. Auxin and its transport play a role in plant tolerance to arsenite-induced oxidative stress in Arabidopsis thaliana.

    PubMed

    Krishnamurthy, Aparna; Rathinasabapathi, Bala

    2013-10-01

    The role of auxin in plant development is well known; however, its possible function in root response to abiotic stress is poorly understood. In this study, we demonstrate a novel role of auxin transport in plant tolerance to oxidative stress caused by arsenite. Plant response to arsenite [As(III)] was evaluated by measuring root growth and markers for stress on seedlings treated with control or As(III)-containing medium. Auxin transporter mutants aux1, pin1 and pin2 were significantly more sensitive to As(III) than the wild type (WT). Auxin transport inhibitors significantly reduced plant tolerance to As(III) in the WT, while exogenous supply of indole-3-acetic acid improved As(III) tolerance of aux1 and not that of WT. Uptake assays using H(3) -IAA showed As(III) affected auxin transport in WT roots. As(III) increased the levels of H2 O2 in WT but not in aux1, suggesting a positive role for auxin transport through AUX1 on plant tolerance to As(III) stress via reactive oxygen species (ROS)-mediated signalling. Compared to the WT, the mutant aux1 was significantly more sensitive to high-temperature stress and salinity, also suggesting auxin transport influences a common element shared by plant tolerance to arsenite, salinity and high-temperature stress.

  1. ARSENITE INDUCTION OF HEME OXYGENASE AS A BIOMARKER

    EPA Science Inventory

    ARSENITE INDUCTION OF HEME OXYGENASE AS A BIOMARKER

    Useful biomarkers of arsenic effects in both experimental animals and humans are needed. Arsenate and arsenite are good inducers of rat hepatic and renal heme oxygenase (HO); monomethylarsonic acid (MMA) and dimethylarsi...

  2. Phenylarsine Oxide Can Induce the Arsenite-Resistance Mutant PML Protein Solubility Changes

    PubMed Central

    Jiang, Yu Han; Chen, Ye Jia; Wang, Chao; Lan, Yong Fei; Yang, Chang; Wang, Qian Qian; Hussain, Liaqat; Maimaitiying, Yasen; Islam, Khairul; Naranmandura, Hua

    2017-01-01

    Arsenic trioxide (As2O3) has recently become one of the most effective drugs for treatment of patient with acute promyelocytic leukemia (APL), and its molecular mechanism has also been largely investigated. However, it has been reported that As2O3 resistant patients are frequently found in relapsed APL after consolidation therapy, which is due to the point mutations in B-box type 2 motifs of promyelocytic leukemia (PML) gene. In the present study, we for the first time establish whether organic arsenic species phenylarsine oxide (PAO) could induce the mutant PML-IV (A216V) protein solubility changes and degradation. Here, three different PML protein variants (i.e., PML-IV, PML-V and mutant PML-A216V) were overexpressed in HEK293T cells and then exposed to PAO in time- and dose-dependent manners. Interestingly, PAO is found to have potential effect on induction of mutant PML-IV (A216V) protein solubility changes and degradation, but no appreciable effects were found following exposure to high concentrations of iAsIII, dimethylarsinous acid (DMAIII) and adriamycin (doxorubicin), even though they cause cell death. Our current data strongly indicate that PAO has good effects on the mutant PML protein solubility changes, and it may be helpful for improving the therapeutic strategies for arsenic-resistant APL treatments in the near future. PMID:28125064

  3. Artesunate induces AIF-dependent apoptosis in A549 cells

    NASA Astrophysics Data System (ADS)

    Zhou, Chen-juan; Chen, Tong-Sheng

    2012-03-01

    Artesunate (ART), a semi-synthetic derivative of the sesquiterpene artemisinin extracted from the Chinese herb Artemisia annua, exerts a broad spectrum of clinical activity against human cancers. It has been shown that ART induces cancer cells death through apoptosis pathway. This study investigated whether ART treatment induced reactive oxygen species (ROS)-dependent cell death in the apoptosis fashion in human lung adenocarconoma A549 cell line and the proapoptotic protein apoptosis inducing factor (AIF) is involved in ART-induced apoptosis. Cells treated with ART exhibited typical apoptotic morphology as chromatin condensation, margination and shrunken nucleus. ART treatment also induced a loss of mitochondrial membrane potential and AIF release from mitochondria. Silencing AIF can remarkable attenuated ART-induced apoptosis. Collectively, ART induces apoptosis by caspase-independent intrinsic pathway in A549 cells.

  4. HIV-1 protease-induced apoptosis

    PubMed Central

    2014-01-01

    Background Apoptosis is one of the presumptive causes of CD4+ T cell depletion during HIV infection and progression to AIDS. However, the precise role of HIV-1 in this process remains unexplained. HIV-1 protease (PR) has been suggested as a possible factor, but a direct link between HIV-1 PR enzymatic activity and apoptosis has not been established. Results Here, we show that expression of active HIV-1 PR induces death in HeLa and HEK-293 cells via the mitochondrial apoptotic pathway. This conclusion is based on in vivo observations of the direct localization of HIV-1 PR in mitochondria, a key player in triggering apoptosis. Moreover, we observed an HIV-1 PR concentration-dependent decrease in mitochondrial membrane potential and the role of HIV-1 PR in activation of caspase 9, PARP cleavage and DNA fragmentation. In addition, in vitro data demonstrated that HIV-1 PR mediates cleavage of mitochondrial proteins Tom22, VDAC and ANT, leading to release of AIF and Hsp60 proteins. By using yeast two-hybrid screening, we also identified a new HIV-1 PR interaction partner, breast carcinoma-associated protein 3 (BCA3). We found that BCA3 accelerates p53 transcriptional activity on the bax promoter, thus elevating the cellular level of pro-apoptotic Bax protein. Conclusion In summary, our results describe the involvement of HIV-1 PR in apoptosis, which is caused either by a direct effect of HIV-1 PR on mitochondrial membrane integrity or by its interaction with cellular protein BCA3. PMID:24886575

  5. Honey induces apoptosis in renal cell carcinoma

    PubMed Central

    Samarghandian, Saeed; Afshari, Jalil Tavakkol; Davoodi, Saiedeh

    2011-01-01

    Background: The fact that antioxidants have several preventative effects against different diseases, such as coronary diseases, inflammatory disorders, neurologic degeneration, aging, and cancer, has led to the search for food rich in antioxidants. Honey has been used as a traditional food and medical source since ancient times. However, recently many scientists have been concentrating on the antioxidant property of honey. By use of human renal cancer cell lines (ACHN), we investigated the antiproliferative activity, apoptosis, and the antitumor activity of honey. Materials and Methods: The cells were cultured in Dulbecco’s modified Eagle’s medium with 10% fetal bovine serum treated with different concentrations of honey for 3 consecutive days. Cell viability was quantitated by the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Apoptotic cells were determined using Annexin-V-fluorescein isothiocyanate (FITC) by flow cytometry. Results: Honey decreased the cell viability in the malignant cells in a concentration- and time-dependent manner. The IC 50 values against the ACHN cell lines were determined as 1.7 ± 0.04% and 2.1 ± 0.03% μg/mL after 48 and 72 h, respectively. Honey induced apoptosis of the ACHN cells in a concentration-dependent manner, as determined by flow cytometry histogram of treated cells. Conclusion: It might be concluded that honey may cause cell death in the ACHN cells, in which apoptosis plays an important role. Most of the drugs used in the cancer treatment are apoptotic inducers, hence apoptotic nature of honey is considered vital. Therefore, it prompted us to investigate honey as a potential candidate for renal cancer treatment. PMID:21472079

  6. Hyperthermia: an effective strategy to induce apoptosis in cancer cells.

    PubMed

    Ahmed, Kanwal; Tabuchi, Yoshiaki; Kondo, Takashi

    2015-11-01

    Heat has been used as a medicinal and healing modality throughout human history. The combination of hyperthermia (HT) with radiation and anticancer agents has been used clinically and has shown positive results to a certain extent. However, the clinical results of HT treatment alone have been only partially satisfactory. Cell death following HT treatment is a function of both temperature and treatment duration. HT induces cancer cell death through apoptosis; the degree of apoptosis and the apoptotic pathway vary in different cancer cell types. HT-induced reactive oxygen species production are responsible for apoptosis in various cell types. However, the underlying mechanism of signal transduction and the genes related to this process still need to be elucidated. In this review, we summarize the molecular mechanism of apoptosis induced by HT, enhancement of heat-induced apoptosis, and the genetic network involved in HT-induced apoptosis.

  7. Apoptosis induced by a human milk protein.

    PubMed

    Håkansson, A; Zhivotovsky, B; Orrenius, S; Sabharwal, H; Svanborg, C

    1995-08-15

    To the breast-fed infant, human milk is more than a source of nutrients; it furnishes a wide array of molecules that restrict microbes, such as antibodies, bactericidins, and inhibitors of bacterial adherence. However, it has rarely been considered that human milk may also contain substances bioactive toward host cells. While investigating the effect of human milk on bacterial adherence to a human lung cancer cell line, we were surprised to discover that the milk killed the cells. Analysis of this effect revealed that a component of milk in a particular physical state--multimeric alpha-lact-albumin--is a potent Ca(2+)-elevating and apoptosis-inducing agent with broad, yet selective, cytotoxic activity. Multimeric alpha-lactalbumin killed all transformed, embryonic, and lymphoid cells tested but spared mature epithelial elements. These findings raise the possibility that milk contributes to mucosal immunity not only by furnishing antimicrobial molecules but also by policing the function of lymphocytes and epithelium. Finally, analysis of the mechanism by which multimeric alpha-lactalbumin induces apoptosis in transformed epithelial cells could lead to the design of antitumor agents.

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

    PubMed

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

    2010-02-05

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

  9. Altered iron homeostasis involvement in arsenite-mediated cell transformation

    PubMed Central

    Wu, Jing; Eckard, Jonathan; Chen, Haobin; Costa, Max; Frenkel, Krystyna; Huang, Xi

    2010-01-01

    Chronic exposure to low doses of arsenite causes transformation of human osteogenic sarcoma (HOS) cells. Although oxidative stress is considered important in arsenite-induced cell transformation, the molecular and cellular mechanisms by which arsenite transforms human cells are still unknown. In the present study, we investigated whether altered iron homeostasis, known to affect cellular oxidative stress, can contribute to the arsenite-mediated cell transformation. Using arsenite-induced HOS cell transformation as a model, it was found that total iron levels are significantly higher in transformed HOS cells in comparison to parental control HOS cells. Under normal iron metabolism conditions, iron homeostasis is tightly controlled by inverse regulation of ferritin and transferrin receptor (TfR) through iron regulatory proteins (IRP). Increased iron levels in arsenite transformed cells should theoretically lead to higher ferritin and lower TfR in these cells than in controls. However, the results showed that both ferritin and TfR are decreased, apparently through two different mechanisms. A lower ferritin level in cytoplasm was due to the decreased mRNA in the arsenite-transformed HOS cells, while the decline in TfR was due to a lowered IRP-binding activity. By challenging cells with iron, it was further established that arsenite-transformed HOS cells are less responsive to iron treatment than control HOS cells, which allows accumulation of iron in the transformed cells, as exemplified by significantly lower ferritin induction. On the other hand, caffeic acid phenethyl ester (CAPE), an antioxidant previously shown to suppress As-mediated cell transformation, prevents As-mediated ferritin depletion. In conclusion, our results suggest that altered iron homeostasis contributes to arsenite-induced oxidative stress and, thus, may be involved in arsenite-mediated cell transformation. PMID:16443159

  10. Aspartame-induced apoptosis in PC12 cells.

    PubMed

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

    2014-01-01

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

  11. Research Advances on Pathways of Nickel-Induced Apoptosis

    PubMed Central

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

    2015-01-01

    High concentrations of nickel (Ni) are harmful to humans and animals. Ni targets a number of organs and produces multiple toxic effects. Apoptosis is important in Ni-induced toxicity of the kidneys, liver, nerves, and immune system. Apoptotic pathways mediated by reactive oxygen species (ROS), mitochondria, endoplasmic reticulum (ER), Fas, and c-Myc participate in Ni-induced cell apoptosis. However, the exact mechanism of apoptosis caused by Ni is still unclear. Understanding the mechanism of Ni-induced apoptosis may help in designing measures to prevent Ni toxicity. PMID:26703593

  12. Quercetin-induced apoptosis prevents EBV infection.

    PubMed

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

    2015-05-20

    Epstein-Barr virus (EBV) is a human gamma-1 herpesvirus that establishes a lifelong latency in over 90% of the world's population. During latency, virus exists predominantly as a chromatin-associated, multicopy episome in the nuclei of a variety of tumor cells derived from B cells, T cells, natural killer (NK) cells, and epithelial cells. Licorice is the root of Glycyrrhiza uralensis or G. glabra that has traditionally cultivated in eastern part of Asia. Licorice was reported to have anti-viral, anti-inflammatory, anti-atopic, hepatoprotective, anti-neurodegenerative, anti-tumor, anti-diabetic effects and so forth. Quercetin and isoliquiritigenin are produced from licorice and highly similar in molecular structure. They have diverse bioactive effects such as antiviral activity, anti-asthmatic activity, anti-cancer activity, anti-inflammation activity, monoamine-oxidase inhibitor, and etc. To determine anti-EBV and anti-EBVaGC (Epstein-Barr virus associated gastric carcinoma) effects of licorice, we investigated antitumor and antiviral effects of quercetin and isoliquiritigenin against EBVaGC. Although both quercetin and isoliquiritigenin are cytotoxic to SNU719 cells, quercetin induced more apoptosis in SNU719 cells than isoliquiritigenin, more completely eliminated DNMT1 and DNMT3A expressions than isoliquiritigenin, and more strongly affects the cell cycle progression of SNU719 than isoliquiritigenin. Both quercetin and isoliquiritigenin induce signal transductions to stimulate apoptosis, and induce EBV gene transcription. Quercetin enhances frequency of F promoter use, whereas isoliquiritigenin enhances frequency of Q promoter use. Quercetin reduces EBV latency, whereas isoliquiritigenin increases the latency. Quercetin increases more the EBV progeny production, and inhibits more EBV infection than isoliquiritigenin. These results indicate that quercetin could be a promising candidate for antiviral and antitumor agents against EBV and human gastric carcinoma.

  13. Quercetin-induced apoptosis prevents EBV infection

    PubMed Central

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

    2015-01-01

    Epstein-Barr virus (EBV) is a human gamma-1 herpesvirus that establishes a lifelong latency in over 90% of the world's population. During latency, virus exists predominantly as a chromatin-associated, multicopy episome in the nuclei of a variety of tumor cells derived from B cells, T cells, natural killer (NK) cells, and epithelial cells. Licorice is the root of Glycyrrhiza uralensis or G. glabra that has traditionally cultivated in eastern part of Asia. Licorice was reported to have anti-viral, anti-inflammatory, anti-atopic, hepatoprotective, anti-neurodegenerative, anti-tumor, anti-diabetic effects and so forth. Quercetin and isoliquiritigenin are produced from licorice and highly similar in molecular structure. They have diverse bioactive effects such as antiviral activity, anti-asthmatic activity, anti-cancer activity, anti-inflammation activity, monoamine-oxidase inhibitor, and etc. To determine anti-EBV and anti-EBVaGC (Epstein-Barr virus associated gastric carcinoma) effects of licorice, we investigated antitumor and antiviral effects of quercetin and isoliquiritigenin against EBVaGC. Although both quercetin and isoliquiritigenin are cytotoxic to SNU719 cells, quercetin induced more apoptosis in SNU719 cells than isoliquiritigenin, more completely eliminated DNMT1 and DNMT3A expressions than isoliquiritigenin, and more strongly affects the cell cycle progression of SNU719 than isoliquiritigenin. Both quercetin and isoliquiritigenin induce signal transductions to stimulate apoptosis, and induce EBV gene transcription. Quercetin enhances frequency of F promoter use, whereas isoliquiritigenin enhances frequency of Q promoter use. Quercetin reduces EBV latency, whereas isoliquiritigenin increases the latency. Quercetin increases more the EBV progeny production, and inhibits more EBV infection than isoliquiritigenin. These results indicate that quercetin could be a promising candidate for antiviral and antitumor agents against EBV and human gastric carcinoma

  14. Apoptosis induced by propolis in human hepatocellular carcinoma cell line.

    PubMed

    Choi, Y H; Lee, W Y; Nam, S Y; Choi, K C; Park, Y E

    1999-07-01

    Propolis has been reported to exhibit a wide spectrum of activities including antibiotic, antiviral, anti-inflammatory, immunostimulatory and tumor carcinostatic properties. We showed propolis induced apoptosis in a human hepatoma cell line (SNU449) by FITC-Annexin V/PI staining. We also compared the apoptosis inducing effect between Korean and Commercial (Sigma # p-1010) propolis. There was no difference on apoptosis between them.

  15. Ferrate(VI)-induced arsenite and arsenate removal by in situ structural incorporation into magnetic iron(III) oxide nanoparticles.

    PubMed

    Prucek, Robert; Tuček, Jiří; Kolařík, Jan; Filip, Jan; Marušák, Zdeněk; Sharma, Virender K; Zbořil, Radek

    2013-04-02

    We report the first example of arsenite and arsenate removal from water by incorporation of arsenic into the structure of nanocrystalline iron(III) oxide. Specifically, we show the capability to trap arsenic into the crystal structure of γ-Fe2O3 nanoparticles that are in situ formed during treatment of arsenic-bearing water with ferrate(VI). In water, decomposition of potassium ferrate(VI) yields nanoparticles having core-shell nanoarchitecture with a γ-Fe2O3 core and a γ-FeOOH shell. High-resolution X-ray photoelectron spectroscopy and in-field (57)Fe Mössbauer spectroscopy give unambiguous evidence that a significant portion of arsenic is embedded in the tetrahedral sites of the γ-Fe2O3 spinel structure. Microscopic observations also demonstrate the principal effect of As doping on crystal growth as reflected by considerably reduced average particle size and narrower size distribution of the "in-situ" sample with the embedded arsenic compared to the "ex-situ" sample with arsenic exclusively sorbed on the iron oxide nanoparticle surface. Generally, presented results highlight ferrate(VI) as one of the most promising candidates for advanced technologies of arsenic treatment mainly due to its environmentally friendly character, in situ applicability for treatment of both arsenites and arsenates, and contrary to all known competitive technologies, firmly bound part of arsenic preventing its leaching back to the environment. Moreover, As-containing γ-Fe2O3 nanoparticles are strongly magnetic allowing their separation from the environment by application of an external magnet.

  16. Arsenite suppression of BMP signaling in human keratinocytes

    SciTech Connect

    Phillips, Marjorie A.; Qin, Qin; Hu, Qin; Zhao, Bin; Rice, Robert H.

    2013-06-15

    Arsenic, a human skin carcinogen, suppresses differentiation of cultured keratinocytes. Exploring the mechanism of this suppression revealed that BMP-6 greatly increased levels of mRNA for keratins 1 and 10, two of the earliest differentiation markers expressed, a process prevented by co-treatment with arsenite. BMP also stimulated, and arsenite suppressed, mRNA for FOXN1, an important transcription factor driving early keratinocyte differentiation. Keratin mRNAs increased slowly after BMP-6 addition, suggesting they are indirect transcriptional targets. Inhibition of Notch1 activation blocked BMP induction of keratins 1 and 10, while FOXN1 induction was largely unaffected. Supporting a requirement for Notch1 signaling in keratin induction, BMP increased levels of activated Notch1, which was blocked by arsenite. BMP also greatly decreased active ERK, while co-treatment with arsenite maintained active ERK. Inhibition of ERK signaling mimicked BMP by inducing keratin and FOXN1 mRNAs and by increasing active Notch1, effects blocked by arsenite. Of 6 dual-specificity phosphatases (DUSPs) targeting ERK, two were induced by BMP unless prevented by simultaneous exposure to arsenite and EGF. Knockdown of DUSP2 or DUSP14 using shRNAs greatly reduced FOXN1 and keratins 1 and 10 mRNA levels and their induction by BMP. Knockdown also decreased activated Notch1, keratin 1 and keratin 10 protein levels, both in the presence and absence of BMP. Thus, one of the earliest effects of BMP is induction of DUSPs, which increases FOXN1 transcription factor and activates Notch1, both required for keratin gene expression. Arsenite prevents this cascade by maintaining ERK signaling, at least in part by suppressing DUSP expression. - Highlights: • BMP induces FOXN1 transcription. • BMP induces DUSP2 and DUSP14, suppressing ERK activation. • Arsenite suppresses levels of phosphorylated Smad1/5 and FOXN1 and DUSP mRNA. • These actions rationalize arsenite suppression of keratinocyte

  17. Apoptosis Induced by Metal Complexes and Interaction with Dexamethasone

    PubMed Central

    Kim, Jung Sun; Barros, José Carlos Almeida

    2002-01-01

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

  18. N-acetylcysteine and meso-2,3-dimercaptosuccinic acid alleviate oxidative stress and hepatic dysfunction induced by sodium arsenite in male rats

    PubMed Central

    Abu El-Saad, Ahmed M; Al-Kahtani, Mohammed A; Abdel-Moneim, Ashraf M

    2016-01-01

    Environmental exposure to arsenic represents a serious challenge to humans and other animals. The aim of the present study was to test the protective effect of antioxidant N-acetylcysteine (NAC) either individually or in combination with a chelating agent, meso-2,3-dimercaptosuccinic acid (DMSA), against sodium arsenite oral toxicity in male rats. Five groups were used: control; arsenic group (orally administrated in a concentration of 2 mg/kg body weight [b.w.]); the other three groups were orally administrated sodium arsenite in a concentration of 2 mg/kg b.w. followed by either NAC (10 mg/kg b.w., intraperitoneally [i.p.]), DMSA (50 mg/kg b.w., i.p.) or NAC plus DMSA. Arsenic toxicity caused significant rise in serum aspartate aminotransferase, alanine aminotransferase and total bilirubin, and a significant decrease in total protein (TP) and albumin levels after 3 weeks of experimental period. In addition, arsenic-treated rats showed significantly higher arsenic content in liver and significant rise in hepatic malondialdehyde level. By contrast, sharp decreases in glutathione content and catalase and glutathione reductase activities were discernible. NAC and/or DMSA counteracted most of these physiologic and biochemical defects. NAC monotherapy was more effective than DMSA in increasing TP, while DMSA was more effective in decreasing alanine aminotransferase. The combined treatment was superior over monotherapies in recovery of TP and glutathione. Biochemical data were well supported by histopathological and ultrastructural findings. In conclusion, the combination therapy of NAC and DMSA may be an ideal choice against oxidative insult induced by arsenic poisoning. PMID:27799742

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

    PubMed

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

    2016-01-05

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

  20. Glucocorticoid-induced apoptosis and cellular mechanisms of myopathy.

    PubMed

    Dirks-Naylor, Amie J; Griffiths, Carrie L

    2009-10-01

    Glucocorticoid-induced myopathy is a common side effect of chronic glucocorticoid therapy. Several mechanisms are currently being examined as ways in which glucocorticoid-induced myopathy occurs. These include apoptotic signaling through mitochondrial-mediated and Fas-mediated apoptosis, the role of the proteosome, the suppression of the IGF-1 signaling, and the role of ceramide in glucocorticoid-induced apoptosis and myopathy. It is difficult to differentiate which mechanism may be the initiating event responsible for the induction of apoptosis; however, all of the mechanisms play a vital role in glucocorticoid-induced myopathy.

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

    PubMed Central

    Elmallah, Mohammed I. Y.; Micheau, Olivier

    2015-01-01

    Marine biomass diversity is a tremendous source of potential anticancer compounds. Several natural marine products have been described to restore tumor cell sensitivity to TNF-related apoptosis inducing ligand (TRAIL)-induced cell death. TRAIL is involved during tumor immune surveillance. Its selectivity for cancer cells has attracted much attention in oncology. This review aims at discussing the main mechanisms by which TRAIL signaling is regulated and presenting how marine bioactive compounds have been found, so far, to overcome TRAIL resistance in tumor cells. PMID:26580630

  2. Mechanisms and Consequences of Ebolavirus-Induced Lymphocyte Apoptosis

    DTIC Science & Technology

    2010-01-01

    system to respond to infection (5, 6). However, recent studies have indicated that a functional CD8+ T cell-mediated immune response is generated in...systemic implications of lymphocyte apoptosis in EBOV infection are known. In this study , we show data suggesting that EBOV-induced lymphocyte apoptosis in...apoptosis in vitro through an unknown mechanism (11). However, no previous studies have analyzed the effect of blocking either the intrinsic or extrinsic

  3. Antagonistic role of tea against sodium arsenite-induced oxidative DNA damage and inhibition of DNA repair in Swiss albino mice.

    PubMed

    Sinha, Dona; Roy, Madhumita

    2011-01-01

    Arsenic (As) contamination in groundwater is of increasing health concern in West Bengal, India. Arsenic has been associated with various human cancers, but the precise mechanism of its co-carcinogenic action is not clearly elucidated. Oxidative stress and defective repair mechanisms may promote accumulation of mutations and may be a stepping stone for carcinogenesis. Prevention of arsenic-induced oxidative stress and repair inhibition may reduce the chances of initiation of cancer. Tea polyphenols are reported to have excellent chemopreventive properties against cancer. This study aimed to elucidate the role of tea against arsenic-induced formation of 8-hydroxy-2'-deoxyguanosine (8OHdG) and arsenic-suppressed DNA repair in Swiss albino mice. Both green and black tea gave fruitful results in the reduction of 8OHdG and 8-oxoguanine DNA glycosylase (OGG1) in Swiss albino mice administered sodium arsenite (As III). DNA repair enzymes--such as PARP1, DNA β-polymerase, XRCC1, DNA ligase III, DNA protein kinase (catalytic subunit), XRCC 4, DNA ligase IV, and DNA topoisomerase IIβ--were induced by the phytochemicals at both the protein and genetic levels. Thus, tea polyphenols may prove effective in treating arsenic-induced carcinogenesis.

  4. [Apoptosis and thymocyte development (epithelial cells as inducers of thymocyte apoptosis)].

    PubMed

    Iarilin, A A; Bulanova, E G; Sharova, N I; Budagian, V M

    1998-01-01

    Apoptosis, together with proliferation, is a main factor of selection of the clones of developing T-lymphocytes: the clones not supported by positive selection are subject to apoptosis and apoptosis accounts for discarding of potentially autoaggressive clones, i.e., for negative selection in the thymus and peripheral lymphoid tissue. Realization of apoptosis at different stages of the development of T-lymphocytes depends to a varying extent on Fas, Bcl-2, p53, and other regulators. The dendritic cells are the main cell type, the contact with determines apoptosis of T-lymphocytes. A possible role of the epithelial cells was shown in few models (on murine cells) and was not practically studied. We obtained a line of epithelial cells of the human thymus cells HTSC, cocultivation with which induces apoptosis of immature thymocytes and blood T-cells activated by mitogens. Development of apoptosis is suppressed by inhibitors of protein and RNA synthesis, chelators Ca2+, ions Zn2+, and factors destroying the cytoskeleton components. In this model, interaction of pairs of molecules CD4-HLA class II and LFA-1-ICAM-1. When in contact with the HTSC cells, the thymocytes of mice mutant for Fas-receptor (line MRL.lpr) are subject to apoptosis, but when this receptor is present, it affects the development of apoptosis.

  5. UXT plays dual opposing roles on SARM-induced apoptosis.

    PubMed

    Sethurathinam, Shalini; Singh, Laishram Pradeepkumar; Panneerselvam, Porkodi; Byrne, Bernadette; Ding, Jeak Ling

    2013-10-11

    Apoptosis is a vital defense mechanism for the clearance of infected cells. Ubiquitously expressed transcript (UXT), which exists in two isoforms (V1 and V2), interact with both apoptotic and cellular proteins. By yeast two-hybrid analysis, we found that UXT interacts with SARM (sterile α and HEAT armadillo motif-containing protein). Since SARM is a TLR adaptor which induces intrinsic apoptosis following immune activation, we were prompted to query whether UXT and SARM might co-regulate apoptosis. We found that the UXT isoforms elicit dual opposing regulatory effects on SARM-induced apoptosis; while UXT V1, co-expressed with SARM, caused a reduction in caspase 8 activity, UXT V2 strongly increased caspase 8 activity and enhanced SARM-induced apoptosis by activating the extrinsic pathway and depolarizing the mitochondria.

  6. Glucocorticoid-induced apoptosis of healthy and malignant lymphocytes

    PubMed Central

    Smith, Lindsay K.; Cidlowski, John A.

    2016-01-01

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

  7. Modulation of Radiation-Induced Apoptosis by Thiolamines

    NASA Technical Reports Server (NTRS)

    Warters, R. L.; Roberts, J. C.; Wilmore, B. H.; Kelley, L. L.

    1997-01-01

    Exposure to the thiolamine radioprotector N-(2-mercaptoethyl)-1,3-propanediamine (WR-1065) induced apoptosis in the mouse TB8-3 hybridoma after 60-minute (LD(sub50) = 4.5mM) or during a 20-hour (LD(sub50) = 0.15 mM) exposure. In contrast, a 20-hour exposure to 17 mM L-cysteine or 10 mM cysteamine was required to induce 50 percent apoptosis within 20 hours. Apoptosis was not induced by either a 60-minute or 20-hour exposure to 10 mM of the thiazolidime prodrugs ribose-cysteine (RibCys) or ribose-cysteamine (RibCyst). Thiolamine-induced apoptosis appeared to be a p53-independent process since it was induced by WR-1065 exposure in human HL60 cells. Exposure to WR-1065 (4mM for 15 minutes) or cysteine (10mM for 60 minutes) before and during irradiation protected cells against the induction of both DNA double-strand breaks and apoptosis, while exposure to RibCys (10 mM for 3 hours) did not. Treatment with either WR-1065, cysteine, RibCys or RibCyst for 60 minutes beginning 60 minutes after irradiation did not affect the level of radiation-induced apoptosis. In contrast, treatment with either cysteine, cysteamine or RibCys for 20 hours beginning 60 minutes after irradiation enhanced radiation-induced apoptosis. Similar experiments could not be conducted with WR-1065 because of its extreme toxicity. Our results indicate that thiolamine enhancement of radiation-induced apoptosis is not involved in their previously reported capacity to reduce radiation-induced mutations.

  8. Zinc pyrithione induces apoptosis and increases expression of Bim.

    PubMed

    Mann, J J; Fraker, P J

    2005-03-01

    We demonstrate herein that zinc pyrithione can induce apoptosis at nanomolar concentrations. Zinc pyrithione was a potent inducer of cell death causing greater than 40-60% apoptosis among murine thymocytes, murine splenic lymphocytes and human Ramos B and human Jurkat T cells. Conversely, the addition of a zinc chelator protected thymocytes against zinc pyrithione induced apoptosis indicating these responses were specific for zinc. Zinc-induced apoptosis was dependent on transcription and translation which suggested possible regulation by a proapoptotic protein. Indeed, zinc induced a 1.9 and 3.4 fold increase respectively in expression of the BimEL and BimL isoforms and also stimulated production of the most potent isoform, BimS. This increase in Bim isoform expression was dependent on transcription being blocked by treatment with actinomycin D. Overexpression of Bcl-2 or Bcl-xL provided substantial protection of Ramos B and Jurkat T cells against zinc-induced apoptosis. Zinc also activated the caspase cascade demonstrated by cleavage of caspase 9. Addition of specific inhibitors for caspase 9 and caspase 3 also blocked zinc-induced apoptosis. The data herein adds to the growing evidence that free or unbound zinc could be harmful to cells of the immune system.

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

    PubMed

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

    2007-08-16

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

  10. Expression of the constitutive and inducible forms of heat shock protein 70 in human proximal tubule cells exposed to heat, sodium arsenite, and CdCl(2).

    PubMed Central

    Somji, S; Todd, J H; Sens, M A; Garrett, S H; Sens, D A

    1999-01-01

    We determined the expression of the constitutive (hsc 70) and inducible (hsp 70) forms of heat shock protein 70 mRNA and protein in human proximal tubule (HPT) cells exposed to lethal and sublethal concentrations of Cd(+2) under both acute and extended conditions of exposure. The HPT cells exhibited the classic heat shock response when subjected to a physical (heat) or chemical stress (sodium arsenite); hsc 70 mRNA and protein levels were constant or slightly increased, whereas hsp 70 mRNA and protein were greatly elevated. Acute exposure to 53.4 microM CdCl(2) for 4 hr failed to increase either hsc 70 mRNA or protein, a finding similar to that observed under classic conditions of stress. However, under identical conditions of acute exposure to Cd(2+), the expected increase in hsp 70 protein level was suppressed as compared to that found under classic conditions of physical or chemical stress. The decrease in hsp 70 protein level correlated to the reduced expression of mRNA from the hsp 70B gene. The expression of mRNA from the hsp 70A and hsp 70C genes was similar to that found when the cells were treated with heat shock or sodium arsenite. We modeled an extended exposure to Cd(2+) by treating the cells continuously with Cd(2+) at both lethal and sublethal levels over a 16-day time course. Chronic exposure to Cd(2+) failed to increase either hsc 70 mRNA or protein levels in the HPT cells at a nonlethal dosage level and decreased hsc 70 mRNA and protein levels late in the time course of lethal exposure. Under identical conditions, the expression of hsp 70 protein remained at basal levels that were only marginally detectable throughout the time course. Hsp 70A and hsp 70C mRNA levels were unaltered by extended exposure to Cd(2+), and hsp 70B mRNA was not detected during the 16-day time course. Cd(2+) is a poor inducer of hsc 70 and hsp 70 in the proximal tubule under both acute and long-term exposure. These results reinforce the fact that the expression of hsp 70

  11. Crizotinib induces PUMA-dependent apoptosis in colon cancer cells.

    PubMed

    Zheng, Xingnan; He, Kan; Zhang, Lin; Yu, Jian

    2013-05-01

    Oncogenic alterations in MET or anaplastic lymphoma kinase (ALK) have been identified in a variety of human cancers. Crizotinib (PF02341066) is a dual MET and ALK inhibitor and approved for the treatment of a subset of non-small cell lung carcinoma and in clinical development for other malignancies. Crizotinib can induce apoptosis in cancer cells, whereas the underlying mechanisms are not well understood. In this study, we found that crizotinib induces apoptosis in colon cancer cells through the BH3-only protein PUMA. In cells with wild-type p53, crizotinib induces rapid induction of PUMA and Bim accompanied by p53 stabilization and DNA damage response. The induction of PUMA and Bim is mediated largely by p53, and deficiency in PUMA or p53, but not Bim, blocks crizotinib-induced apoptosis. Interestingly, MET knockdown led to selective induction of PUMA, but not Bim or p53. Crizotinib also induced PUMA-dependent apoptosis in p53-deficient colon cancer cells and synergized with gefitinib or sorafenib to induce marked apoptosis via PUMA in colon cancer cells. Furthermore, PUMA deficiency suppressed apoptosis and therapeutic responses to crizotinib in xenograft models. These results establish a critical role of PUMA in mediating apoptotic responses of colon cancer cells to crizotinib and suggest that mechanisms of oncogenic addiction to MET/ALK-mediated survival may be cell type-specific. These findings have important implications for future clinical development of crizotinib.

  12. Apoptosis in vascular cells induced by cold atmospheric plasma treatment

    NASA Astrophysics Data System (ADS)

    Sladek, Raymond; Stoffels, Eva

    2006-10-01

    Apoptosis is a natural mechanism of cellular self-destruction. It can be triggered by moderate, yet irreversible damage. Apoptosis plays a major role in tissue renewal. Artificial apoptosis induction will become a novel therapy that meets all requirements for tissue-saving surgery. Diseased tissues can disappear without inflammation and scarring. This is particularly important in treatment of blockages in body tracts (e.g. cardiovascular diseases). Artificial induction of apoptosis can be achieved by means of cold plasma treatment. In this work an atmospheric micro-plasma operated in helium/air has been used to induce apoptosis in vascular cells. Parametric studies of apoptosis induction have been conducted; the efficiency is almost 100%. The apoptotic factors are ROS/RNS (reactive oxygen and nitrogen species). Their densities in the plasma have been measured by mass spectrometry. For apoptosis induction, RNS seem to be more important than ROS, because of their relative abundance. Moreover, addition of a ROS scavenger (ascorbic acid) to the cell culture medium does not reduce the occurrence of apoptosis. Cold plasma is a very efficient tool for fundamental studies of apoptosis, and later, for controlled tissue removal in vivo.

  13. Glucocorticoid Induced Leucine Zipper inhibits apoptosis of cardiomyocytes by doxorubicin

    SciTech Connect

    Aguilar, David; Strom, Joshua; Chen, Qin M.

    2014-04-01

    Doxorubicin (Dox) is an indispensable chemotherapeutic agent for the treatment of various forms of neoplasia such as lung, breast, ovarian, and bladder cancers. Cardiotoxicity is a major concern for patients receiving Dox therapy. Previous work from our laboratory indicated that glucocorticoids (GCs) alleviate Dox-induced apoptosis in cardiomyocytes. Here we have found Glucocorticoid-Induced Leucine Zipper (GILZ) to be a mediator of GC-induced cytoprotection. GILZ was found to be induced in cardiomyocytes by GC treatment. Knocking down of GILZ using siRNA resulted in cancelation of GC-induced cytoprotection against apoptosis by Dox treatment. Overexpressing GILZ by transfection was able to protect cells from apoptosis induced by Dox as measured by caspase activation, Annexin V binding and morphologic changes. Western blot analyses indicate that GILZ overexpression prevented cytochrome c release from mitochondria and cleavage of caspase-3. When bcl-2 family proteins were examined, we found that GILZ overexpression causes induction of the pro-survival protein Bcl-xL. Since siRNA against Bcl-xL reverses GC induced cytoprotection, Bcl-xL induction represents an important event in GILZ-induced cytoprotection. Our data suggest that GILZ functions as a cytoprotective gene in cardiomyocytes. - Highlights: • Corticosteroids act as a cytoprotective agent in cardiomyocytes • Corticosteroids induce GILZ expression in cardiomyocytes • Elevated GILZ results in resistance against apoptosis induced by doxorubicin • GILZ induces Bcl-xL protein without inducing Bcl-xL mRNA.

  14. Wogonin Induces Eosinophil Apoptosis and Attenuates Allergic Airway Inflammation

    PubMed Central

    Dorward, David A.; Sharma, Sidharth; Rennie, Jillian; Felton, Jennifer M.; Alessandri, Ana L.; Duffin, Rodger; Schwarze, Jurgen; Haslett, Christopher; Rossi, Adriano G.

    2015-01-01

    Rationale: Eosinophils are key effector cells in allergic diseases, including allergic rhinitis, eczema, and asthma. Their tissue presence is regulated by both recruitment and increased longevity at inflamed sites. Objectives: To investigate the ability of the flavone wogonin to induce eosinophil apoptosis in vitro and attenuate eosinophil-dominant allergic inflammation in vivo in mice. Methods: Human and mouse eosinophil apoptosis in response to wogonin was investigated by cellular morphology, flow cytometry, mitochondrial membrane permeability, and pharmacological caspase inhibition. Allergic lung inflammation was modeled in mice sensitized and challenged with ovalbumin. Bronchoalveolar lavage (BAL) and lung tissue were examined for inflammation, mucus production, and inflammatory mediator production. Airway hyperresponsiveness to aerosolized methacholine was measured. Measurements and Main Results: Wogonin induced time- and concentration-dependent human and mouse eosinophil apoptosis in vitro. Wogonin-induced eosinophil apoptosis occurred with activation of caspase-3 and was inhibited by pharmacological caspase inhibition. Wogonin administration attenuated allergic airway inflammation in vivo with reductions in BAL and interstitial eosinophil numbers, increased eosinophil apoptosis, reduced airway mucus production, and attenuated airway hyperresponsiveness. This wogonin-induced reduction in allergic airway inflammation was prevented by concurrent caspase inhibition in vivo. Conclusions: Wogonin induces eosinophil apoptosis and attenuates allergic airway inflammation, suggesting that it has therapeutic potential for the treatment of allergic inflammation in humans. PMID:25629436

  15. Ibuprofen enhances TRAIL-induced apoptosis through DR5 upregulation.

    PubMed

    Todo, Momoko; Horinaka, Mano; Tomosugi, Mitsuhiro; Tanaka, Ryoichi; Ikawa, Haruna; Sowa, Yoshihiro; Ishikawa, Hideki; Fujiwara, Hitoshi; Otsuji, Eigo; Sakai, Toshiyuki

    2013-11-01

    Numerous human chemoprevention studies have demonstrated that non-steroidal anti-inflammatory drugs (NSAIDs) possess chemopreventive effects against a variety of malignant tumors. However, there have been many clinical studies on aspirin, but not ibuprofen, even though ibuprofen is one of the most clinically and safely used NSAIDs showing potent anti-inflammatory effects. Moreover, we reported that many chemopreventive agents enhance the apoptosis-inducing effects of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), which is known to be crucial for cancer prevention. We, therefore, investigated whether ibuprofen enhances the cytocidal effect of TRAIL and found that ibuprofen markedly stimulated the apoptosis-inducing efficacy of TRAIL against human colon cancer HCT116 cells. As detected by western blot analysis and real-time RT-PCR, ibuprofen upregulated the expression of death receptor 5 (DR5), a TRAIL receptor. TRAIL-induced apoptosis enhanced by ibuprofen was effectively decreased by a caspase inhibitor and dominant-negative DR5. Noteworthy, co-treatment of ibuprofen with TRAIL did not enhance apoptosis in normal peripheral blood mononuclear cells (PBMCs). These results demonstrated that ibuprofen and TRAIL synergistically induced apoptosis in human colon cancer HCT116 cells but not in normal PBMCs, raising the possibility that ibuprofen may be promising as a safe chemopreventive agent against colon cancer.

  16. Resveratrol inhibits TIGAR to promote ROS induced apoptosis and autophagy.

    PubMed

    Kumar, Bhupender; Iqbal, Mohammad Askandar; Singh, Rajnish Kumar; Bamezai, Rameshwar N K

    2015-11-01

    Resveratrol has been shown to exhibit its anti-cancer effect through a variety of mechanisms. Here, TIGAR (TP53-Induced Glycolysis and Apoptosis Regulator) was identified as an important target of resveratrol for exhibiting ROS-dependent-consequences on apoptosis and autophagy. Resveratrol treatment decreased TIGAR protein irrespective of cell line used. Down-regulated TIGAR protein triggered a drop in reduced-glutathione levels which resulted in sustained ROS, responsible for apoptosis and autophagy. Over-expression and silencing experiments demonstrated the importance of TIGAR in affecting the ROS-dependent anti-cancer effects of resveratrol. Resveratrol treated cells exhibited autophagy to escape apoptosis, however, chloroquine treatment along with resveratrol, blocked protective autophagy and facilitated apoptosis. Collectively, results unravel the effects of resveratrol on TIGAR in mediating its ROS dependent influence and suggest a better combination therapy of resveratrol and chloroquine for probable cancer treatment.

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

    PubMed

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

    2015-10-05

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

  18. X-ray-induced cell death: Apoptosis and necrosis

    SciTech Connect

    Nakano, Hisako; Shinohara, Kunio

    1994-10-01

    X-ray-induced cell death in MOLT-4N1, a subclone of MOLT-4 cells, and M10 cells was studied with respect to their modes of cell death, apoptosis and necrosis. MOLT-4N1 cells showed radiosensitivity similar to that of M10 cells, a radiosensitive mutant of L5178Y, as determined by the colony formation assay. Analysis of cell size demonstrated that MOLT-4N1 cells increased in size at an early stage after irradiation and then decreased to a size smaller than that of control cells, whereas the size of irradiated M10 cells increased continuously. Apoptosis detected by morphological changes and DNA ladder formation (the cleavage of DNA into oligonucleosomal fragments) occurred in X-irradiated MOLT-4N1 cells but not in M10 cells. Pulsed-field gel electrophoresis showed that the ladder formation involved an intermediate-sized DNA (about 20 kbp). Most of the DNA was detected at the origin in both methods of electrophoresis in the case of M10 cells, though a trace amount of ladder formation was observed. Heat treatment of M10 cells induced apoptosis within 30 min after treatment, in contrast to MOLT-4N1 cells. The results suggest that apoptosis and necrosis are induced by X rays in a manner which is dependent on the cell line irrespective of the capability of the cells to develop apoptosis. DNA fragmentation was the earliest change observed in the development of apoptosis. 27 refs., 8 figs., 1 tab.

  19. Sodium fluoride induces apoptosis in cultured splenic lymphocytes from mice

    PubMed Central

    Cui, Hengmin; Chen, Lian; Fang, Jing; Zuo, Zhicai; Deng, Junliang; Wang, Xun; Zhao, Ling

    2016-01-01

    Though fluorine has been shown to induce apoptosis in immune organs in vivo, there has no report on fluoride-induced apoptosis in the cultured lymphocytes. Therefore, this study was conducted with objective of investigating apoptosis induced by sodium fluoride (NaF) and the mechanism behind that in the cultured splenic lymphocytes by flow cytometry, western blot and Hoechst 33258 staining. The splenic lymphocytes were isolated from 3 weeks old male ICR mice and exposed to NaF (0, 100, 200, and 400 μmol/L) in vitro for 24 and 48 h. When compared to control group, flow cytometry assay and Hoechst 33258 staining showed that NaF induced lymphocytes apoptosis, which was promoted by decrease of mitochondria transmembrane potential, up-regulation of Bax, Bak, Fas, FasL, caspase 9, caspase 8, caspase 7, caspase 6 and caspase 3 protein expression (P < 0.05 or P <0.01), and down-regulation of Bcl-2 and Bcl-xL protein expression (P <0.05 or P <0.01). The above-mentioned data suggested that NaF-induced apoptosis in splenic lymphocytes could be mediated by mitochondrial and death receptor pathways. PMID:27655720

  20. Neem oil limonoids induces p53-independent apoptosis and autophagy.

    PubMed

    Srivastava, Pragya; Yadav, Neelu; Lella, Ravi; Schneider, Andrea; Jones, Anthony; Marlowe, Timothy; Lovett, Gabrielle; O'Loughlin, Kieran; Minderman, Hans; Gogada, Raghu; Chandra, Dhyan

    2012-11-01

    Azadirachta indica, commonly known as neem, has a wide range of medicinal properties. Neem extracts and its purified products have been examined for induction of apoptosis in multiple cancer cell types; however, its underlying mechanisms remain undefined. We show that neem oil (i.e., neem), which contains majority of neem limonoids including azadirachtin, induced apoptotic and autophagic cell death. Gene silencing demonstrated that caspase cascade was initiated by the activation of caspase-9, whereas caspase-8 was also activated late during neem-induced apoptosis. Pretreatment of cancer cells with pan caspase inhibitor, z-VAD inhibited activities of both initiator caspases (e.g., caspase-8 and -9) and executioner caspase-3. Neem induced the release of cytochrome c and apoptosis-inducing factor (AIF) from mitochondria, suggesting the involvement of both caspase-dependent and AIF-mediated apoptosis. p21 deficiency caused an increase in caspase activities at lower doses of neem, whereas p53 deficiency did not modulate neem-induced caspase activation. Additionally, neem treatment resulted in the accumulation of LC3-II in cancer cells, suggesting the involvement of autophagy in neem-induced cancer cell death. Low doses of autophagy inhibitors (i.e., 3-methyladenine and LY294002) did not prevent accumulation of neem-induced LC3-II in cancer cells. Silencing of ATG5 or Beclin-1 further enhanced neem-induced cell death. Phosphoinositide 3-kinase (PI3K) or autophagy inhibitors increased neem-induced caspase-3 activation and inhibition of caspases enhanced neem-induced autophagy. Together, for the first time, we demonstrate that neem induces caspase-dependent and AIF-mediated apoptosis, and autophagy in cancer cells.

  1. Arsenite decreases CYP3A23 induction in cultured rat hepatocytes by transcriptional and translational mechanisms

    SciTech Connect

    Noreault, Trisha L.; Nichols, Ralph C.; Trask, Heidi W.; Wrighton, Steven A.; Sinclair, Peter R.; Evans, Ronald M.; Sinclair, Jacqueline F. . E-mail: JSINC@dartmouth.edu

    2005-12-01

    Arsenic is a naturally occurring, worldwide contaminant implicated in numerous pathological conditions in humans, including cancer and several forms of liver disease. One of the contributing factors to these disorders may be the alteration of cytochrome P450 (CYP) levels by arsenic. In rat and human hepatocyte cultures, arsenic, in the form of arsenite, decreases the induction of several CYPs. The present study investigated whether arsenite utilizes transcriptional or post-transcriptional mechanisms to decrease CYP3A23 in primary cultures of rat hepatocytes. In these cultures, a 6-h treatment with 5 {mu}M arsenite abolished dexamethasone (DEX)-mediated induction of CYP3A23 protein and activity, but did not inhibit general protein synthesis. However, arsenite treatment only reduced DEX-induced levels of CYP3A23 mRNA by 30%. The effects of arsenite on CYP3A23 transcription were examined using a luciferase reporter construct containing 1.4 kb of the CYP3A23 promoter. Arsenite caused a 30% decrease in DEX-induced luciferase expression of this reporter. Since arsenite abolished induction of CYP3A23 protein, but caused only a small decrease in CYP3A23 mRNA, the effects of arsenite on translation of CYP3A23 mRNA were investigated. Polysomal distribution analysis showed that arsenite decreased translation by decreasing the DEX-mediated increase in CYP3A23 mRNA association with polyribosomes. Arsenite did not decrease intracellular glutathione or increase lipid peroxidation, suggesting that the effect of arsenite on CYP3A23 does not involve oxidative stress. Overall, the results suggest that low-level arsenite decreases both transcription and translation of CYP3A23 in primary rat hepatocyte cultures.

  2. Simulating cell apoptosis induced sinus node dysfunction.

    PubMed

    Kharche, Sanjay; Beling, John; Biktasheva, Irina V; Zhang, Henggui; Biktashev, Vadim N

    2013-01-01

    Sinus node dysfunction (SND) is correlated to the pacemaker sinoatrial node (SAN) cell apoptosis. This study explores the effect of such a dysfunctional SAN on electrical propagation into neighboring atrial tissue. The Fenton Karma model was extended to simulate mouse SAN and atrial cell action potentials. The cell models were incorporated into a 2D model consisting of a central SAN region surrounded by atrial tissue. The intercellular gap junctional coupling, as quantified by the diffusion constant, was estimated to give conduction speeds as observed in mouse atrial tissue. The size of mouse SAN pacemaking region was estimated using the 2D model. In multiple simulations, the effects of an increasing proportion of apoptotic pacemaker cells on atrial tissue pacing were simulated and quantified. The SAN size that gave a basal mouse atrial cycle length (ACL) of 295 ms was found to be 0.6 mm in radius. At low pacemaker cell apoptosis proportion, there was a drastic increase of ACL. At modest increase in the number of apoptotic cells, bradycardia was observed. The incidence of sinus arrest was also found to be high. When the number of apoptotic cells were 10% of the total number of pacemaking cells, all pacemaking was arrested. Phenomenological models have been developed to study mouse atrial electrophysiology and confirm experimental findings. The results show the significance of cell apoptosis as a major mechanism of SND.

  3. Sodium arsenite alters cell cycle and MTHFR, MT1/2, and c-Myc protein levels in MCF-7 cells

    SciTech Connect

    Ruiz-Ramos, Ruben; Lopez-Carrillo, Lizbeth; Albores, Arnulfo; Hernandez-Ramirez, Raul U.; Cebrian, Mariano E.

    2009-12-15

    There is limited available information on the effects of arsenic on enzymes participating in the folate cycle. Therefore, our aim was to evaluate the effects of sodium arsenite on the protein levels of methylenetetrahydrofolate reductase (MTHFR) and dihydrofolate reductase (DHFR) and its further relationship with the expression MT1/2 and c-myc in MCF-7 cells. Arsenite treatment (0-10 muM) for 4 h decreased MTHFR levels in a concentration-dependent fashion without significant effects on DHFR. The effects on MTHFR were observed at arsenite concentrations not significantly affecting cell viability. We also observed an increase in S-phase recruitment at all concentrations probed. Lower concentrations (< 5 muM) induced cell proliferation, showing a high proportion of BrdU-stained cells, indicating a higher DNA synthesis rate. However, higher concentrations (>= 5 muM) or longer treatment periods induced apoptosis. Arsenite also induced dose-dependent increases in MT1/2 and c-Myc protein levels. The levels of MTHFR were inversely correlated to MT1/2 and c-Myc overexpression and increased S-phase recruitment. Our findings indicate that breast epithelial cells are responsive to arsenite and suggest that exposure may pose a risk for breast cancer. The reductions in MTHFR protein levels contribute to understand the mechanisms underlying the induction of genes influencing growth regulation, such as c-myc and MT1/2. However, further research is needed to ascertain if the effects here reported following short-time and high-dose exposure are relevant for human populations chronically exposed to low arsenic concentrations.

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

    PubMed

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

    2014-10-30

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

  5. Osteoblasts Protect AML Cells from SDF-1-Induced Apoptosis

    PubMed Central

    Kremer, Kimberly N.; Dudakovic, Amel; McGee-Lawrence, Meghan E.; Philips, Rachael L.; Hess, Allan D.; Smith, B. Douglas; van Wijnen, Andre J.; Karp, Judith E.; Kaufmann, Scott H.; Westendorf, Jennifer J.; Hedin, Karen E.

    2014-01-01

    The bone marrow provides a protective environment for acute myeloid leukemia (AML) cells that often allows leukemic stem cells to survive standard chemotherapeutic regimens. Targeting these leukemic stem cells within the bone marrow is critical for preventing relapse. We recently demonstrated that SDF-1, a chemokine abundant in the bone marrow, induces apoptosis in AML cell lines and in patient samples expressing high levels of its receptor, CXCR4. Here we show that a subset of osteoblast lineage cells within the bone marrow can protect AML cells from undergoing apoptosis in response to the SDF-1 naturally present in that location. In co-culture systems, osteoblasts at various stages of differentiation protected AML cell lines and patient isolates from SDF-1-induced apoptosis. The differentiation of the osteoblast cell lines, MC3T3 and W-20-17, mediated this protection via a cell contact-independent mechanism. In contrast, bone marrow-derived mesenchymal cells, the precursors of osteoblasts, induced apoptosis in AML cells via a CXCR4-dependent mechanism and failed to protect AML cells from exogenously added SDF-1. These results indicate that osteoblasts in the process of differentiation potently inhibit the SDF-1-driven apoptotic pathway of CXCR4-expressing AML cells residing in the bone marrow. Drugs targeting this protective mechanism could potentially provide a new approach to treating AML by enhancing the SDF-1-induced apoptosis of AML cells residing within the bone marrow microenvironment. PMID:24851270

  6. Hydrogen peroxide induces apoptosis via a mitochondrial pathway in chondrocytes

    NASA Astrophysics Data System (ADS)

    Zhuang, Cai-ping; Liang, Qian; Wang, Xiao-ping; Chen, Tong-sheng

    2012-03-01

    The degenerative joint disease such as osteoarthritis (OA) is closely associated with the death of chondrocytes in apoptosis fashion. Hydrogen peroxide (H2O2), higher expression following acute damage in OA patients, has been shown to be up-regulated during apoptosis in a bulk of experimental models. This study was aimed to explore the mechanism of H2O2-induced rabbit chondrocytes apoptosis. Articular cartilage was biopsied from the joints of 6 weeks old New Zealand rabbits. Cell Counting Kit (CCK-8) assay was used to assess the inhibitory effect of H2O2 on cell viability. H2O2 treatment induced a remarkable reduction of cell viability. We used flow cytometry to assess the form of cell death with Annexin-V/PI double staining, and found that H2O2 treatment induced apoptosis in a dose-and time-dependent manner. Exposure of chondrocytes to 1.5 mM of H2O2 for 2 h induced a burst apoptosis that can be alleviated by N-acetyl cysteine (NAC) pretreatment, an anti-oxidant amino-acid derivative. Loss of mitochondria membrane potential (▵Ψm) was evaluated using confocal microscopy imaging and flow cytometry (FCM). H2O2 treatment induced a marked reduction of ▵Ψm, and the abrupt disappearance of ▵Ψm occurred within 5 minutes. These results indicate that H2O2 induces a rapid apoptosis via a mitochondrial pathway in rabbit chondrocytes.

  7. Interferon-γ Plays Protective Roles in Sodium Arsenite-Induced Renal Injury by Up-Regulating Intrarenal Multidrug Resistance-Associated Protein 1 Expression

    PubMed Central

    Kimura, Akihiko; Ishida, Yuko; Hayashi, Takahito; Wada, Takashi; Yokoyama, Hitoshi; Sugaya, Takeshi; Mukaida, Naofumi; Kondo, Toshikazu

    2006-01-01

    Subcutaneous injection of sodium arsenite (NaAs, 12.5 mg/kg) into BALB/c [wild-type (WT)] mice causes acute renal dysfunction characterized by severe hemorrhages, acute tubular necrosis, and cast formation, with increases in serum blood urea nitrogen and creatinine levels. Concomitant enhancement in intrarenal interferon (IFN)-γ expression prompted us to examine its roles in this pathology. IFN-γ-deficient (IFN-γ−/−) mice exhibited higher serum blood urea nitrogen and creatinine levels and exaggerated histopathological changes, compared with WT mice. Eventually, IFN-γ−/− mice exhibited a high mortality (87.5%) within 24 hours after NaAs challenge, whereas most WT mice survived. The intrarenal arsenic concentration was significantly higher in IFN-γ−/− mice later than 10 hours after NaAs treatment, with attenuated intrarenal expression of multidrug resistance-associated protein (MRP) 1, a main transporter for NaAs efflux, compared with WT mice. NF-E2-related factor (Nrf) 2 protein, a transcription factor crucial for MRP1 gene expression, was similarly increased in the kidneys of both strains of mice after NaAs treatment. In contrast, the absence of IFN-γ augmented transforming growth factor-β-Smad3 signal pathway and eventually enhanced the expression of activating transcription factor 3, which is presumed to repress Nrf2-mediated MRP1 gene expression. Thus, IFN-γ can protect against NaAs-induced acute renal injury, probably by maintaining Nrf2-mediated intrarenal MRP1 gene expression. PMID:17003472

  8. Arsenite Effects on Mitochondrial Bioenergetics in Human and Mouse Primary Hepatocytes Follow a Nonlinear Dose Response

    PubMed Central

    Christudoss, Pamela; Mickey, Kristen; Tessman, Robert; Ni, Hong-min; Swerdlow, Russell

    2017-01-01

    Arsenite is a known carcinogen and its exposure has been implicated in a variety of noncarcinogenic health concerns. Increased oxidative stress is thought to be the primary cause of arsenite toxicity and the toxic effect is thought to be linear with detrimental effects reported at all concentrations of arsenite. But the paradigm of linear dose response in arsenite toxicity is shifting. In the present study we demonstrate that arsenite effects on mitochondrial respiration in primary hepatocytes follow a nonlinear dose response. In vitro exposure of primary hepatocytes to an environmentally relevant, moderate level of arsenite results in increased oxidant production that appears to arise from changes in the expression and activity of respiratory Complex I of the mitochondrial proton circuit. In primary hepatocytes the excess oxidant production appears to elicit adaptive responses that promote resistance to oxidative stress and a propensity to increased proliferation. Taken together, these results suggest a nonlinear dose-response characteristic of arsenite with low-dose arsenite promoting adaptive responses in a process known as mitohormesis, with transient increase in ROS levels acting as transducers of arsenite-induced mitohormesis. PMID:28163822

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

    PubMed

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

    2013-01-01

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

  10. Mechanisms of sulindac-induced apoptosis and cell cycle arrest.

    PubMed

    Jung, Barbara; Barbier, Valerie; Brickner, Howard; Welsh, John; Fotedar, Arun; McClelland, Michael

    2005-02-28

    The mechanism underlying the chemopreventive effects of the non-steroidal anti-inflammatory drug sulindac remains unclear. Its active metabolite, sulindac sulfide, induces cell cycle arrest as well as apoptosis in mammalian cell lines. We now show that in murine thymocytes, sulindac sulfide-induced cell death is p53, bax, Fas, and FasL independent. In contrast, bcl2 transgenic thymocytes are resistant to sulindac sulfide-induced apoptosis. In addition, we demonstrate that sulindac sulfide-induced cell cycle arrest in mouse embryonic fibroblasts (MEFs) is partly mediated by the retinoblastoma tumor suppressor protein (Rb) and the cyclin kinase inhibitor p21waf1/cip1. Furthermore, MEFs deficient in p21 or Rb are more susceptible to sulindac sulfide-induced cell death. These results suggest that sulindac may selectively target premalignant cells with cell cycle checkpoint deficits.

  11. Hydrogen peroxide-induced apoptosis in human gingival fibroblasts.

    PubMed

    Gutiérrez-Venegas, Gloria; Guadarrama-Solís, Adriana; Muñoz-Seca, Carmen; Arreguín-Cano, Juan Antonio

    2015-01-01

    In the process of bleaching vital, discolored teeth, low concentrations of hydrogen peroxide (H2O2) are effective alternatives to heat-activated 30% H2O2. However, interest has been expressed in the assessment of pathological effects of long-term exposure to bleaching agents such as irritation and ulceration of the gingival or other soft tissues. The aim of the present study was to determine the effect of hydrogen peroxide on apoptosis in human gingival fibroblasts (HGF). Cytochrome c, Bcl-2, Bax, Bid and caspase-3 protein expression were detected by Western blotting. HGF cell apoptosis induced by H2O2 was both dose and time dependent. The addition of H2O2 resulted in the release of cytochrome c to the cytosol, and an increase of Caspase-3 cleavage. Data suggest that oxidative stress-induced apoptosis in HGF is intrinsic pathway involved the release of apoptotic signal from mitochondria.

  12. Hydrogen peroxide-induced apoptosis in human gingival fibroblasts

    PubMed Central

    Gutiérrez-Venegas, Gloria; Guadarrama-Solís, Adriana; Muñoz-Seca, Carmen; Arreguín-Cano, Juan Antonio

    2015-01-01

    In the process of bleaching vital, discolored teeth, low concentrations of hydrogen peroxide (H2O2) are effective alternatives to heat-activated 30% H2O2. However, interest has been expressed in the assessment of pathological effects of long-term exposure to bleaching agents such as irritation and ulceration of the gingival or other soft tissues. The aim of the present study was to determine the effect of hydrogen peroxide on apoptosis in human gingival fibroblasts (HGF). Cytochrome c, Bcl-2, Bax, Bid and caspase-3 protein expression were detected by Western blotting. HGF cell apoptosis induced by H2O2 was both dose and time dependent. The addition of H2O2 resulted in the release of cytochrome c to the cytosol, and an increase of Caspase-3 cleavage. Data suggest that oxidative stress-induced apoptosis in HGF is intrinsic pathway involved the release of apoptotic signal from mitochondria. PMID:26884825

  13. Tubular cell apoptosis and cidofovir-induced acute renal failure.

    PubMed

    Ortiz, Alberto; Justo, Pilar; Sanz, Ana; Melero, Rosa; Caramelo, Carlos; Guerrero, Manuel Fernández; Strutz, Frank; Müller, Gerhard; Barat, Antonio; Egido, Jesus

    2005-01-01

    Cidofovir is an antiviral drug with activity against a wide array of DNA viruses including poxvirus. The therapeutic use of cidofovir is marred by a dose-limiting side effect, nephrotoxicity, leading to proximal tubular cell injury and acute renal failure. Treatment with cidofovir requires the routine use of prophylactic measures. A correct knowledge of the cellular and molecular mechanisms of cidofovir toxicity may lead to the development of alternative prophylactic strategies. We recently cared for a patient with irreversible acute renal failure due to cidofovir. Renal biopsy showed tubular cell apoptosis. Cidofovir induced apoptosis in primary cultures of human proximal tubular cells in a temporal (peak apoptosis at 7 days) and concentration (10-40 microg/ml) pattern consistent with that of clinical toxicity. Apoptosis was identified by the presence of hypodiploid cells, by the exposure of annexin V binding sites and by morphological features and was associated with the appearance of active caspase-3 fragments. Cell death was specific as it was also present in a human proximal tubular epithelial cell line (HK-2), but not in a human kidney fibroblast cell line, and was prevented by probenecid. An inhibitor of caspase-3 (DEVD) prevented cidofovir apoptosis. The survival factors present in serum, insulin-like growth factor-1 and hepatocyte growth factor, were also protective. The present data suggest that apoptosis induction is a mechanism contributing to cidofovir nephrotoxicity. The prophylactic administration of factors with survival activity for tubular epithelium should be further explored in cidofovir renal injury.

  14. Salmonella typhimurium Invasion Induces Apoptosis in Infected Macrophages

    NASA Astrophysics Data System (ADS)

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

    1996-09-01

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

  15. Aniline Induces Oxidative Stress and Apoptosis of Primary Cultured Hepatocytes.

    PubMed

    Wang, Yue; Gao, Hong; Na, Xiao-Lin; Dong, Shu-Ying; Dong, Hong-Wei; Yu, Jia; Jia, Li; Wu, Yong-Hui

    2016-11-30

    The toxicity and carcinogenicity of aniline in humans and animals have been well documented. However, the molecular mechanism involved in aniline-induced liver toxicity and carcinogenesis remains unclear. In our research, primary cultured hepatocytes were exposed to aniline (0, 1.25, 2.50, 5.0 and 10.0 μg/mL) for 24 h in the presence or absence of N-acetyl-l-cysteine (NAC). Levels of reactive oxygen species (ROS), malondialdehyde (MDA), and glutathione (GSH), activities of superoxide dismutase (SOD) and catalase (CAT), mitochondrial membrane potential, DNA damage, cell viability, and apoptosis were detected. Levels of ROS and MDA were significantly increased and levels of GSH and CAT, activity of SOD, and mitochondrial membrane potential in hepatocytes were significantly decreased by aniline compared with the negative control group. The tail moment and DNA content of the tail in exposed groups were significantly higher than those in the negative control group. Cell viability was reduced and apoptotic death was induced by aniline in a concentration-dependent manner. The phenomena of ROS generation, oxidative damage, loss of mitochondrial membrane potential, DNA damage and apoptosis could be prevented if ROS inhibitor NAC was added. ROS generation is involved in the loss of mitochondrial membrane potential and DNA injury, which may play a role in aniline-induced apoptosis in hepatocytes. Our study provides insight into the mechanism of aniline-induced toxicity and apoptosis of hepatocytes.

  16. Aniline Induces Oxidative Stress and Apoptosis of Primary Cultured Hepatocytes

    PubMed Central

    Wang, Yue; Gao, Hong; Na, Xiao-Lin; Dong, Shu-Ying; Dong, Hong-Wei; Yu, Jia; Jia, Li; Wu, Yong-Hui

    2016-01-01

    The toxicity and carcinogenicity of aniline in humans and animals have been well documented. However, the molecular mechanism involved in aniline-induced liver toxicity and carcinogenesis remains unclear. In our research, primary cultured hepatocytes were exposed to aniline (0, 1.25, 2.50, 5.0 and 10.0 μg/mL) for 24 h in the presence or absence of N-acetyl-l-cysteine (NAC). Levels of reactive oxygen species (ROS), malondialdehyde (MDA), and glutathione (GSH), activities of superoxide dismutase (SOD) and catalase (CAT), mitochondrial membrane potential, DNA damage, cell viability, and apoptosis were detected. Levels of ROS and MDA were significantly increased and levels of GSH and CAT, activity of SOD, and mitochondrial membrane potential in hepatocytes were significantly decreased by aniline compared with the negative control group. The tail moment and DNA content of the tail in exposed groups were significantly higher than those in the negative control group. Cell viability was reduced and apoptotic death was induced by aniline in a concentration-dependent manner. The phenomena of ROS generation, oxidative damage, loss of mitochondrial membrane potential, DNA damage and apoptosis could be prevented if ROS inhibitor NAC was added. ROS generation is involved in the loss of mitochondrial membrane potential and DNA injury, which may play a role in aniline-induced apoptosis in hepatocytes. Our study provides insight into the mechanism of aniline-induced toxicity and apoptosis of hepatocytes. PMID:27916916

  17. ELEVATED LEVELS OF INDUCIBLE HEAT SHOCK PROTEIN (HSP70-1) PROTECT MCF-7 CELLS FROM ARSENITE TOXICITY

    EPA Science Inventory

    Heat shock proteins (HSPs) belong to the highly conserved family of stress proteins and are induced following exposure to arsenic. Elevated HSPs protect against cellular damage from heat but it is unclear whether HSP induction alters the damaging effects of environmental chemical...

  18. INDUCIBLE HEAT SHOCK PROTEIN (HSP70-1) PROTECTS MCF-7 CELLS FROM THE CYTOTOXIC AND GENOTOXIC EFFECTS OF ARSENITE

    EPA Science Inventory

    Heat shock proteins (HSPs) belong to the highly conserved family of stress proteins and are induced following exposure to arsenic. Elevated HSPs protect against cellular damage from heat but it is unclear wether HSP induction alters the damaging effects of environmental chemical ...

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

    PubMed

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

    2010-11-05

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

  20. Molecular Mechanisms of Par-4-Induced Apoptosis in Prostate Cancer

    DTIC Science & Technology

    2007-05-01

    Sambrook J, Fritsch EF, Maniatis T. (1989). Molecular Cloning : A Laboratory Manual (Cold Spring Harbor, New York: Cold Spring Harbor Laboratory...AD_________________ Award Number: W81XWH-05-1-0622 TITLE: Molecular Mechanisms of Par-4-Induced...SUBTITLE 5a. CONTRACT NUMBER Molecular Mechanisms of Par-4-Induced Apoptosis in Prostate Cancer 5b. GRANT NUMBER W81XWH-05-1-0622 5c. PROGRAM

  1. Determinants of PDT-induced apoptosis

    NASA Astrophysics Data System (ADS)

    Kessel, David; Luo, Yu; Kim, Hyeong-Reh C.

    2000-03-01

    Photodynamic therapy can initiate cell death by apoptosis or necrosis. Using agents with known patterns of sub-cellular localization, we examined the correlation between sites of photodamage and the mode of cell death, using murine leukemia cells in vitro. Mitochondrial or mitochondrial/lysosomal photodamage caused the rapid release of cytochrome c. This effect was not temperature sensitive, and could be demonstrated immediately after irradiation of photosensitized cells at 10 degrees C. Subsequent warming to 37 degrees C led to a rapid apoptotic response, consistent with the known ability of cytochrome c to trigger the activation of caspase-3. In contrast, lysosomal or lysosomal/membrane photodamage resulted in the release of cathepsins and other proteolytic enzymes. A subsequent incubation at 37 degrees C resulted in mitochondrial degradation, leading to loss of cytochrome c within 30 min. The apoptotic response was both delayed and incomplete, with many dead cells not exhibiting an apoptotic morphology. The latter outcome was traced to photodamage to procaspase-3, an effect not observed with sensitizers that caused mainly mitochondrial photodamage. Studies in a cell-free system demonstrated that agents with lysosomal and/or membrane targets could bring about photoinactivation of caspase-3. These result are consistent with the proposal that photodynamic therapy can both activate and inactivate components of the apoptotic process.

  2. Arsenite and insulin exhibit opposing effects on epidermal growth factor receptor and keratinocyte proliferative potential

    SciTech Connect

    Patterson, Timothy J.; Rice, Robert H. . E-mail: rhrice@ucdavis.edu

    2007-05-15

    Previous work has suggested that arsenic exposure contributes to skin carcinogenesis by preserving the proliferative potential of human epidermal keratinocytes, thereby slowing the exit of putative target stem cells into the differentiation pathway. To find a molecular basis for this action, present work has explored the influence of arsenite on keratinocyte responses to epidermal growth factor (EGF). The ability of cultured keratinocytes to found colonies upon passaging several days after confluence was preserved by arsenite and EGF in an additive fashion, but neither was effective when the receptor tyrosine kinase activity was inhibited. Arsenite prevented the loss of EGF receptor protein and phosphorylation of tyrosine 1173, preserving its capability to signal. The level of nuclear {beta}-catenin was higher in cells treated with arsenite and EGF in parallel to elevated colony forming ability, and expression of a dominant negative {beta}-catenin suppressed the increase in both colony forming ability and yield of putative stem cells induced by arsenite and EGF. As judged by expression of three genes regulated by {beta}-catenin, this transcription factor had substantially higher activity in the arsenite/EGF-treated cells. Trivalent antimony exhibited the same effects as arsenite. A novel finding is that insulin in the medium induced the loss of EGF receptor protein, which was largely prevented by arsenite exposure.

  3. Perfluorooctane sulfonate induces apoptosis in N9 microglial cell line.

    PubMed

    Zhang, Ling; Li, Yuan-yuan; Zeng, Huai-cai; Li, Miao; Wan, Yan-Jian; Schluesener, Hermann J; Zhang, Zhi-yuan; Xu, Shun-qing

    2011-03-01

    Perfluorooctane sulfonate (PFOS) is an environmental persistent acid found at low levels in human, wildlife, and environmental media samples. To study the apoptosis effects of PFOS on microglia, murine N9 cell line was used as a model in current research. The results showed that PFOS could reduce the cell viability significantly, and the cellular apoptosis induced by PFOS was closely accompanied with dissipation of mitochondria membrane potential, upregulation messenger RNAs (mRNAs) of p53, Bax, caspase 9, and caspase 3, and decreased expression of Bcl-2 mRNA. These results suggested that PFOS could disturb homeostasis of N9 cells, impact mitochondria, and affect gene expression of apoptotic regulators, all of which resulted in a start-up of apoptosis.

  4. Osthole induces lung cancer cell apoptosis through inhibition of inhibitor of apoptosis family proteins

    PubMed Central

    Xu, Xiao-Man; Zhang, Man-Li; Zhang, Yi; Zhao, Li

    2016-01-01

    In the present study, we investigated the effects and mechanisms of Osthole on the apoptosis of non-small cell lung cancer (NSCLC) cells and its synergistic effect with Embelin. Our results revealed that treatment with both Osthole and Embelin inhibited cell proliferation. Notably, combination treatment of Osthole and Embelin inhibited cell proliferation more significantly compared with monotherapy. In addition, morphological analysis and Annexin V/propidium iodide analysis revealed that the combination of Osthole and Embelin enhanced their effect on cell apoptosis. We further examined the effect of Osthole on the expression of inhibitor of apoptosis protein (IAP) family proteins. That treatment of A549 lung cancer cells with various concentrations of Osthole was observed to decrease the protein expression of X-chromosome-encoded IAP, c-IAP1, c-IAP2 and Survivin, and increase Smac expression in a dose-dependent manner. Furthermore, it was noted that Osthole or Embelin alone increased the expression of BAX, caspase-3, caspase-9, cleaved caspase-3 and cleaved caspase-9, and decreased Bcl-2 levels following treatment. Osthole and Embelin combination treatment had a synergistic effect on the regulation of these proteins. In conclusion, our study demonstrated that Osthole inhibited proliferation and induced the apoptosis of lung cancer cells via IAP family proteins in a dose-dependent manner. Osthole enhances the antitumor effect of Embelin, indicating that combination of Osthole and Embelin has potential clinical significance in the treatment of NSCLC. PMID:27895730

  5. Antioxidant Potential of Spirulina platensis Mitigates Oxidative Stress and Reprotoxicity Induced by Sodium Arsenite in Male Rats.

    PubMed

    Bashandy, Samir A E; El Awdan, Sally A; Ebaid, Hossam; Alhazza, Ibrahim M

    2016-01-01

    The present study aimed to examine the protective role of Spirulina platensis (S. platensis) against arsenic-induced testicular oxidative damage in rats. Arsenic (in the form of NaAsO2 at a dose of 6.3 mg/kg body weight for 8 weeks) caused a significant accumulation of arsenic in testicular tissues as well as a decrease in the levels of testicular superoxide dismutase (SOD), catalase (CAT), reduced glutathione, and zinc. Moreover, it significantly decreased plasma testosterone, luteinizing hormone (LH), triiodothyronine (T3), and thyroxine (T4) levels and reduced sperm motility and sperm count. Arsenic (AS) led to a significant increase in testicular malondialdehyde (MDA), tumour necrosis factor alpha (TNF-α), nitric oxide (NO), and sperm abnormalities. S. platensis at a dose of 300 mg/kg was found to attenuate As-induced oxidative stress, testicular damage, and sperm abnormalities by its potent antioxidant activity. S. platensis may represent a potential therapeutic option to protect the testicular tissue from arsenic intoxication.

  6. Antioxidant Potential of Spirulina platensis Mitigates Oxidative Stress and Reprotoxicity Induced by Sodium Arsenite in Male Rats

    PubMed Central

    Bashandy, Samir A. E.; El Awdan, Sally A.; Ebaid, Hossam; Alhazza, Ibrahim M.

    2016-01-01

    The present study aimed to examine the protective role of Spirulina platensis (S. platensis) against arsenic-induced testicular oxidative damage in rats. Arsenic (in the form of NaAsO2 at a dose of 6.3 mg/kg body weight for 8 weeks) caused a significant accumulation of arsenic in testicular tissues as well as a decrease in the levels of testicular superoxide dismutase (SOD), catalase (CAT), reduced glutathione, and zinc. Moreover, it significantly decreased plasma testosterone, luteinizing hormone (LH), triiodothyronine (T3), and thyroxine (T4) levels and reduced sperm motility and sperm count. Arsenic (AS) led to a significant increase in testicular malondialdehyde (MDA), tumour necrosis factor alpha (TNF-α), nitric oxide (NO), and sperm abnormalities. S. platensis at a dose of 300 mg/kg was found to attenuate As-induced oxidative stress, testicular damage, and sperm abnormalities by its potent antioxidant activity. S. platensis may represent a potential therapeutic option to protect the testicular tissue from arsenic intoxication. PMID:26881036

  7. Manganese induced apoptosis in haematopoietic cells of Nephrops norvegicus (L.).

    PubMed

    Oweson, Carolina A M; Baden, Susanne P; Hernroth, Bodil E

    2006-05-10

    Manganese (Mn) is highly abundant as MnO2 in marine sediments. During hypoxia in bottom waters, the reduced bioavailable fraction of manganese, Mn2+, increases. Thereby, Norway lobster, Nephrops norvegicus, can experience concentrations up to 1000 times normoxic levels. A previous study has shown that exposure to a realistic concentration of 20 mg l(-1) of Mn for 10 days reduced the number of circulating haemocytes in N. norvegicus significantly. Here we aimed to investigate if apoptosis contributes to the Mn-induced haemocytopenia, with the overall hypothesis that Mn induces apoptosis in a time and concentration dependent manner. N. norvegicus were exposed to Mn (0, 5, 10 and 20 mg l(-1)) for 5 and 10 days. After 5 days of exposure the total haemocyte counts were not affected. However, after 10 days there was a gradual decrease in cell numbers, reaching a reduction by 44% when the animals were exposed to 20 mg Mn l(-1). Apoptosis in cells, released from the haematopoietic tissue, was investigated by using TUNEL assay, which detects specific DNA strand breaks. The fraction of apoptotic cells gradually increased from 2.5% in un-exposed lobsters to 15% in those exposed to 20 mg l(-1) but there was no difference related to the exposure time. A gradual increase of apoptosis was further confirmed by electrophoretic DNA-ladder formation, however to a lower extent in lobsters exposed during 5 days. Cell viability, determined by metabolic activity and cell membrane integrity, was not reduced, indicating that apoptosis rather than necrosis caused reduced number of haemocytes. It was concluded that apoptosis seemed to increase already after 5 days of 5 mg l(-1) of Mn-exposure, although exposure for 10 days was required before it was reflected in the haemocyte numbers. Reduced numbers of haemocytes may increase the prevalence for infections in N. norvegicus in their natural habitat.

  8. Lipid Peroxidation in Brain Tissue Following Administration of Low and High Doses of Arsenite and L-Ascorbate in Wistar Strain Rats

    PubMed Central

    Adegunlola, J. G.; Afolabi, O. K.; Akhigbe, R. E.; Adegunlola, G. A.; Adewumi, O. M.; Oyeyipo, I. P.; Ige, S. F.; Afolabi, A. O.

    2012-01-01

    This study aimed at investigating the mechanism by which sodium arsenite induces brain injury and the role of L-ascorbate. Thirty adult (n=5) Wistar rats weighing between 140 and 160 g were used. Group 1 neither received sodium arsenite nor L-ascorbate (control), group 2 was administered low dose of arsenite only, group 3 received high dose of arsenite only, group 4 was administered L-ascorbate only, group 5 was administered low dose of arsenite and L-ascorbate, and group 6 received high dose of arsenite and L-ascorbate. M0 alon dialdehyde, MDA, levels were significantly increased in rats treated with high dose of arsenite when compared with those treated with low dose of arsenite. However, all treated groups except those treated with L-ascorbate only showed significant increase in MDA levels when compared with the control group. Rats treated with high dose of arsenite and L-ascorbate showed a significantly higher MDA level than those treated with low dose of arsenite and L-ascorbate. However, catalase activity, body weight gain, brain weight and mean food consumption were comparable across all groups. Brain tissue total protein was similar in all groups except in both groups treated with high dose of arsenite, where they were significantly reduced when compared with the control group. I0 n conclusion, sodium arsenite treatment induces brain injury via a mechanism associated with lipid peroxidation, but not catalase-dependent. However, L-ascorbate ameliorates arsenite-induced oxidative injury in the brain. L-ascorbate antioxidative potential in alleviating arsenite-induced brain injury is dependent on the concentration of arsenite. PMID:22736903

  9. p73-induced apoptosis: A question of compartments and cooperation

    SciTech Connect

    Dobbelstein, Matthias; Strano, Sabrina; Roth, Judith; Blandino, Giovanni . E-mail: blandino@ifo.it

    2005-06-10

    The transcriptionally active forms of p73 are capable of inducing apoptosis, and the isoforms termed TAp73 are important players when E2F and its oncogenic activators induce programmed cell death. However, the conditions under that TAp73 can kill a cell remain to be clarified. Recently, it has been found that p73 proteins are not merely floating in the nucleoplasm but rather can associate with specific compartments in the cell. Examples of intranuclear compartments associated with p73 proteins include the PML oncogenic domains and the nuclear matrix. In addition, p73 is found in the cytoplasm. It remains to be seen whether p73 might also associate with mitochondria, in analogy with p53. The relocalization of p73 is expected to be mediated by specific binding partners, mostly other proteins. Here, we discuss the possibility that the compartmentalization of p73, and the cooperation with the corresponding binding partners, might decide about its apoptosis-inducing activity.

  10. Targeting prohibitins induces apoptosis in acute myeloid leukemia cells

    PubMed Central

    Pomares, Helena; Palmeri, Claudia M; Iglesias-Serret, Daniel; Moncunill-Massaguer, Cristina; Saura-Esteller, José; Núñez-Vázquez, Sonia; Gamundi, Enric; Arnan, Montserrat; Preciado, Sara; Albericio, Fernando; Lavilla, Rodolfo; Pons, Gabriel; González-Barca, Eva M

    2016-01-01

    Fluorizoline is a new synthetic molecule that induces apoptosis by selectively targeting prohibitins (PHBs). In this study, the pro-apoptotic effect of fluorizoline was assessed in two cell lines and 21 primary samples from patients with debut of acute myeloid leukemia (AML). Fluorizoline induced apoptosis in AML cells at concentrations in the low micromolar range. All primary samples were sensitive to fluorizoline irrespectively of patients' clinical or genetic features. In addition, fluorizoline inhibited the clonogenic capacity and induced differentiation of AML cells. Fluorizoline increased the mRNA and protein levels of the pro-apoptotic BCL-2 family member NOXA both in cell lines and primary samples analyzed. These results suggest that targeting PHBs could be a new therapeutic strategy for AML. PMID:27542247

  11. Analogs of farnesylcysteine induce apoptosis in HL-60 cells.

    PubMed

    Pérez-Sala, D; Gilbert, B A; Rando, R R; Cañada, F J

    1998-04-24

    S-Farnesyl-thioacetic acid (FTA), a competitive inhibitor of isoprenylated protein methyltransferase, potently suppressed the growth of HL-60 cells and induced apoptosis, as evidenced by the development of increased annexin-V binding, decreased binding of DNA dyes and internucleosomal DNA degradation. FTA did not impair the membrane association of ras proteins, conversely, it brought about a decrease in the proportion of ras present in the cytosolic fraction. Farnesylated molecules which are weak inhibitors of the methyltransferase also induced DNA laddering and reduced the proportion of cytosolic ras. These findings suggest that neither inhibition of isoprenylated protein methylation nor impairment of ras membrane association are essential for apoptosis induced by farnesylcysteine analogs.

  12. Molecular Mechanisms of Particle Ration Induced Apoptosis in Lymphocyte

    NASA Astrophysics Data System (ADS)

    Shi, Yufang

    Space radiation, composed of high-energy charged nuclei (HZE particles) and protons, has been previously shown to severely impact immune homeostasis in mice. To determine the molecular mechanisms that mediate acute lymphocyte depletion following exposure to HZE particle radiation mice were exposed to particle radiation beams at Brookhaven National Laboratory. We found that mice given whole body 5 6Fe particle irradiation (1GeV /n) had dose-dependent losses in total lymphocyte numbers in the spleen and thymus (using 200, 100 and 50 cGy), with thymocytes being more sensitive than splenocytes. All phenotypic subsets were reduced in number. In general, T cells and B cells were equally sensitive, while CD8+ T cells were more senstive than CD4+ T cells. In the thymus, immature CD4+CD8+ double-positive thymocytes were exquisitely sensitive to radiation-induced losses, single-positive CD4 or CD8 cells were less sensitive, and the least mature double negative cells were resistant. Irradiation of mice deficient in genes encoding essential apoptosis-inducing proteins revealed that the mechanism of lymphocyte depletion is independent of Fas ligand and TRAIL (TNF-ralated apoptosis-inducing ligand), in contrast to γ-radiation-induced lymphocyte losses which require the Fas-FasL pathway. Using inhibitors in vitro, lymphocyte apoptosis induced by HZE particle radiation was found to be caspase dependent, and not involve nitric oxide or oxygen free radicals.

  13. Silibinin ameliorates arsenic induced nephrotoxicity by abrogation of oxidative stress, inflammation and apoptosis in rats.

    PubMed

    Prabu, S Milton; Muthumani, M

    2012-12-01

    Arsenic (As) is an environmental and industrial pollutant that affects various organs in human and experimental animals. Silibinin is a naturally occurring plant bioflavonoid found in the milk thistle of Silybum marianum, which has been reported to have a wide range of pharmacological properties. A body of evidence has accumulated implicating the free radical generation with subsequent oxidative stress in the biochemical and molecular mechanisms of As toxicity. Since kidney is the critical target organ of chronic As toxicity, we carried out this study to investigate the effects of silibinin on As-induced toxicity in the kidney of rats. In experimental rats, oral administration of sodium arsenite [NaAsO(2), 5 mg/(kg day)] for 4 weeks significantly induced renal damage which was evident from the increased levels of serum urea, uric acid, creatinine with a significant (p < 0.05) decrease in creatinine clearance. As also significantly decreased the levels of urea, uric acid and creatinine in urine. A markedly increased levels of lipid peroxidation markers (thiobarbituric acid reactive substances and lipid hydroperoxides) and protein carbonyl contents with significant (p < 0.05) decrease in non-enzymatic antioxidants (total sulfhydryl groups, reduced glutathione, vitamin C and vitamin E) and enzymatic antioxidants (superoxide dismutase, catalase, glutathione peroxidase and glutathione S-transferase), Glutathione metabolizing enzymes (glutathione reductase and glutathione-6-phosphate dehydrogenase) and membrane bound ATPases were also observed in As treated rats. Co-administration of silibinin (75 mg/kg day) along with As resulted in a reversal of As-induced biochemical changes in kidney accompanied by a significant decrease in lipid peroxidation and an increase in the level of renal antioxidant defense system. The histopathological and immunohistochemical studies in the kidney of rats also shows that silibinin (75 mg/kg day) markedly reduced the toxicity of As and

  14. Herbal Medicine as Inducers of Apoptosis in Cancer Treatment

    PubMed Central

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

    2014-01-01

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

  15. Calnexin deficiency and endoplasmic reticulum stress-induced apoptosis.

    PubMed

    Zuppini, Anna; Groenendyk, Jody; Cormack, Lori A; Shore, Gordon; Opas, Michal; Bleackley, R Chris; Michalak, Marek

    2002-02-26

    In this study, we used calnexin-deficient cells to investigate the role of this protein in ER stress-induced apoptosis. We found that calnexin-deficient cells are relatively resistant to ER stress-induced apoptosis. However, caspase 3 and 8 cleavage and cytochrome c release were unchanged in these cells, indicating that ER to mitochondria "communication" during apoptotic stimulation is not affected in the absence of calnexin. The Bcl-2:Bax ratio was also not significantly changed in calnexin-deficient cells regardless of whether the ER stress was induced with thapsigargin or not. Ca(2+) homeostasis and ER morphology were unaffected by the lack of calnexin, but ER stress-induced Bap31 cleavage was significantly inhibited. Immunoprecipitation experiments revealed that Bap31 forms complexes with calnexin, which may play a role in apoptosis. The results suggest that calnexin may not play a role in the initiation of the ER stress but that the protein has an effect on later apoptotic events via its influence on Bap31 function.

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

    PubMed

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

    2016-04-15

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

  17. Cuprous oxide nanoparticles selectively induce apoptosis of tumor cells

    PubMed Central

    Wang, Ye; Zi, Xiao-Yuan; Su, Juan; Zhang, Hong-Xia; Zhang, Xin-Rong; Zhu, Hai-Ying; Li, Jian-Xiu; Yin, Meng; Yang, Feng; Hu, Yi-Ping

    2012-01-01

    In the rapid development of nanoscience and nanotechnology, many researchers have discovered that metal oxide nanoparticles have very useful pharmacological effects. Cuprous oxide nanoparticles (CONPs) can selectively induce apoptosis and suppress the proliferation of tumor cells, showing great potential as a clinical cancer therapy. Treatment with CONPs caused a G1/G0 cell cycle arrest in tumor cells. Furthermore, CONPs enclosed in vesicles entered, or were taken up by mitochondria, which damaged their membranes, thereby inducing apoptosis. CONPs can also produce reactive oxygen species (ROS) and initiate lipid peroxidation of the liposomal membrane, thereby regulating many signaling pathways and influencing the vital movements of cells. Our results demonstrate that CONPs have selective cytotoxicity towards tumor cells, and indicate that CONPs might be a potential nanomedicine for cancer therapy. PMID:22679374

  18. Pulse mode of laser photodynamic treatment induced cell apoptosis.

    PubMed

    Klimenko, Vladimir V; Knyazev, Nickolay A; Moiseenko, Fedor V; Rusanov, Anatoliy A; Bogdanov, Alexey A; Dubina, Michael V

    2016-03-01

    One of the factors limiting photodynamic therapy (PDT) is hypoxia in tumor cells during photodynamic action. PDT with pulse mode irradiation and appropriate irradiation parameters could be more effective in the singlet oxygen generation and tissue re-oxygenation than continuous wave (CW) mode. We theoretically demonstrate differences between the cumulative singlet oxygen concentration in PDT using pulse mode and CW mode of laser irradiation. In vitro experimental results show that photodynamic treatment with pulse mode irradiation has similar cytotoxicity to CW mode and induces mainly cell apoptosis, whereas CW mode induces necrotic cell death. We assume that the cumulative singlet oxygen concentration and the temporal distribution of singlet oxygen are important in photodynamic cytotoxicity and apoptosis initiation. We expect our research may improve irradiation protocols and photodynamic therapy efficiency.

  19. Alpha particles induce apoptosis through the sphingomyelin pathway.

    PubMed

    Seideman, Jonathan H; Stancevic, Branka; Rotolo, Jimmy A; McDevitt, Michael R; Howell, Roger W; Kolesnick, Richard N; Scheinberg, David A

    2011-10-01

    The sphingomyelin pathway involves the enzymatic cleavage of sphingomyelin to produce ceramide, a second messenger that serves as a key mediator in the rapid apoptotic response to various cell stressors. Low-linear energy transfer (LET) γ radiation can initiate this pathway, independent of DNA damage, via the cell membrane. Whether short-ranged, high-LET α particles, which are of interest as potent environmental carcinogens, radiotherapies and potential components of dirty bombs, can act through this mechanism to signal apoptosis is unknown. Here we show that irradiation of Jurkat cells with α particles emitted by the ²²⁵Ac-DOTA-anti-CD3 IgG antibody construct results in dose-dependent apoptosis. This apoptosis was significantly reduced by pretreating cells with cholesterol-depleting nystatin, a reagent known to inhibit ceramide signaling by interfering with membrane raft coalescence and ceramide-rich platform generation. The effects of nystatin on α-particle-induced apoptosis were related to disruption of the ceramide pathway and not to microdosimetry alterations, because similar results were obtained after external irradiation of the cells with a broad beam of collimated α particles using a planar ²⁴¹Am source. External irradiation allowed for more precise control of the dosimetry and geometry of the irradiation, independent of antibody binding or cell internalization kinetics. Mechanistically consistent with these findings, Jurkat cells rapidly increased membrane concentrations of ceramide after external irradiation with an average of five α-particle traversals per cell. These data indicate that α particles can activate the sphingomyelin pathway to induce apoptosis.

  20. Butyrate-Induced Apoptosis in Prostate Cancer Cell Lines

    DTIC Science & Technology

    2001-09-01

    butyrate-induced apoptosis was independent of cell cycle phase. 14. SUBJECT TERMS 15. NUMBER OF PAGES prostate cancer, histone deacetylase inhibitors, bone...of cells plated) HDI histone deacetylase inhibitor SBHA suberoylbishydroxamate PKC protein kinase C activator SDS-PAGE SDS polyacrylamide gel...cancer cell lines 1. Summary of goals and findings Histone deacetylase inhibitors (HDI) such as butyrate and suberoylbishydroxamate (SBHA) have

  1. Acetaminophen Induces Apoptosis in Rat Cortical Neurons

    PubMed Central

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

    2010-01-01

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

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

    PubMed Central

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

    2001-01-01

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

  3. The antiangiogenic agent Neovastat (AE-941) induces endothelial cell apoptosis.

    PubMed

    Boivin, Dominique; Gendron, Sébastien; Beaulieu, Edith; Gingras, Denis; Béliveau, Richard

    2002-08-01

    Neovastat (AE-941), a naturally occurring multifunctional antiangiogenic agent, has been shown to inhibit key components of the angiogenic process, including matrix metalloproteinases and vascular endothelial growth factor-mediated signaling events. In this study, we report the presence of a proapoptotic activity within this compound. Neovastat treatment of bovine aortic endothelial cells caused cell death with characteristics of apoptosis, including chromatin condensation and DNA fragmentation. Neovastat markedly induced caspase-3, caspase-8, and caspase-9 activities, at similar levels to those measured in cells treated with tumor necrosis factor-alpha. Activation of caspases by Neovastat appears to be essential for its proapoptotic effects because all apoptotic features were blocked by zVAD-fmk, a broad-spectrum caspase inhibitor. The activation of caspases was correlated with the cleavage of the nuclear substrate poly(ADP-ribose) polymerase, and by a concomitant release of cytochrome c from mitochondria to the cytoplasm. Neovastat-induced apoptosis appears to be specific to endothelial cells because treatment of other cell types such as U-87, COS-7, NIH-3T3, and SW1353 did not result in increased caspase-3 activity. These results demonstrate that Neovastat contains a proapoptotic factor that specifically induces the activation of caspases in endothelial cells and the resulting apoptosis of these cells.

  4. Idelalisib induces PUMA-dependent apoptosis in colon cancer cells

    PubMed Central

    Yang, Shida; Zhu, Zhiyong; Zhang, Xiaobing; Zhang, Ning; Yao, Zhicheng

    2017-01-01

    Idelalisib, a PI3K inhibitor, specifically targeting p110δ, has been approved for the treatment of chronic lymphocytic leukemia/small lymphocytic lymphoma and follicular lymphoma. However, the mechanisms of action of idelalisib in colon cancer cells are not well understood. We investigated how idelalisib suppresses colon cancer cells growth and potentiates effects of other chemotherapeutic drugs. In this study, we found that idelalisib treatment induces PUMA in colon cancer cells irrespective of p53 status through the p65 pathway following AKT inhibition and glycogen synthase kinase 3β (GSK3β) activation. PUMA is necessary for idelalisib-induced apoptosis in colon cancer cells. Idelalisib also synergized with 5-FU or regorafenib to induce marked apoptosis via PUMA in colon cancer cells. Furthermore, PUMA deficiency suppressed apoptosis and antitumor effect of idelalisib in xenograft model. These results demonstrate a critical role of PUMA in mediating the anticancer effects of idelalisib in colon cancer cells and suggest that PUMA induction can be used as an indicator of idelalisib sensitivity, and also have important implications for it clinical applications. PMID:28008149

  5. Proteasomal Dysfunction Induced By Diclofenac Engenders Apoptosis Through Mitochondrial Pathway.

    PubMed

    Amanullah, Ayeman; Upadhyay, Arun; Chhangani, Deepak; Joshi, Vibhuti; Mishra, Ribhav; Yamanaka, Koji; Mishra, Amit

    2017-05-01

    Diclofenac is the most commonly used phenylacetic acid derivative non-steroidal anti-inflammatory drug (NSAID) that demonstrates significant analgesic, antipyretic, and anti-inflammatory effects. Several epidemiological studies have demonstrated anti-proliferative activity of NSAIDs and examined their apoptotic induction effects in different cancer cell lines. However, the precise molecular mechanisms by which these pharmacological agents induce apoptosis and exert anti-carcinogenic properties are not well known. Here, we have observed that diclofenac treatment induces proteasome malfunction and promotes accumulation of different critical proteasome substrates, including few pro-apoptotic proteins in cells. Exposure of diclofenac consequently elevates aggregation of various ubiquitylated misfolded proteins. Finally, we have shown that diclofenac treatment promotes apoptosis in cells, which could be because of mitochondrial membrane depolarization and cytochrome c release into cytosol. This study suggests possible beneficial insights of NSAIDs-induced apoptosis that may improve our existing knowledge in anti-proliferative interspecific strategies development. J. Cell. Biochem. 118: 1014-1027, 2017. © 2016 Wiley Periodicals, Inc.

  6. Idelalisib induces PUMA-dependent apoptosis in colon cancer cells.

    PubMed

    Yang, Shida; Zhu, Zhiyong; Zhang, Xiaobing; Zhang, Ning; Yao, Zhicheng

    2017-01-24

    Idelalisib, a PI3K inhibitor, specifically targeting p110δ, has been approved for the treatment of chronic lymphocytic leukemia/small lymphocytic lymphoma and follicular lymphoma. However, the mechanisms of action of idelalisib in colon cancer cells are not well understood. We investigated how idelalisib suppresses colon cancer cells growth and potentiates effects of other chemotherapeutic drugs. In this study, we found that idelalisib treatment induces PUMA in colon cancer cells irrespective of p53 status through the p65 pathway following AKT inhibition and glycogen synthase kinase 3β (GSK3β) activation. PUMA is necessary for idelalisib-induced apoptosis in colon cancer cells. Idelalisib also synergized with 5-FU or regorafenib to induce marked apoptosis via PUMA in colon cancer cells. Furthermore, PUMA deficiency suppressed apoptosis and antitumor effect of idelalisib in xenograft model. These results demonstrate a critical role of PUMA in mediating the anticancer effects of idelalisib in colon cancer cells and suggest that PUMA induction can be used as an indicator of idelalisib sensitivity, and also have important implications for it clinical applications.

  7. CHEMOSENSITIZATION BY A NON-APOPTOGENIC HEAT SHOCK PROTEIN 70-BINDING APOPTOSIS INDUCING FACTOR MUTANT

    EPA Science Inventory

    Chemosensitization by a non-apoptogenic heat shock protein 70-binding apoptosis inducing factor mutant

    Abstract
    HSP70 inhibits apoptosis by neutralizing the caspase activator Apaf-1 and by interacting with apoptosis inducing factor (AIF), a mitochondrial flavoprotein wh...

  8. Holothuria leucospilota Extract Induces Apoptosis in Leishmania major Promastigotes

    PubMed Central

    FOROUTAN-RAD, Masoud; KHADEMVATAN, Shahram; SAKI, Jasem; HASHEMITABAR, Mahmoud

    2016-01-01

    Background: The present study aimed to survey antileishmanial activity of methanolic Holothuria leucospilota extract against Leishmania major promastigotes in vitro. Methods: Promastigotes were cultured in RPMI 1640 and after reaching the stationary phase, the study was conducted with different concentrations of the extract. Afterwards, MTT colorimetric assay for the obtaining of 50% inhibitory concentration (IC50) was utilized. Furthermore, in order to determine the possible induction of apoptosis in L. major promastigotes, flow cytometry and DNA fragmentation methods were employed using annexin-V FLUOS staining kit and DNA ladder kit, respectively. Results: The IC50 value of H. leucospilota extract at three time points of 24, 48, and 72 h was estimated 2000, 300 and 85 μg/ml, respectively. In addition, the extract revealed a dose and time-dependent antileishmanial activity. Furthermore, various characteristics of apoptosis appeared after L. major promastigotes treatment, which included cell shrinkage, formation of apoptotic bodies, blebbing of the cell membrane, and externalization of phosphatidylserine, although no laddering pattern was observed. Conclusion: The methanolic extract of H. leucospilota possesses lethal effect on L. major promastigotes and induces the apoptosis in parasites. Further studies are required to address the apoptosis mechanism in vivo. PMID:28127339

  9. Oxidative Stress Mediates Radiation Lung Injury by Inducing Apoptosis

    SciTech Connect

    Zhang Yu; Zhang Xiuwu; Rabbani, Zahid N.; Jackson, Isabel L.; Vujaskovic, Zeljko

    2012-06-01

    Purpose: Apoptosis in irradiated normal lung tissue has been observed several weeks after radiation. However, the signaling pathway propagating cell death after radiation remains unknown. Methods and Materials: C57BL/6J mice were irradiated with 15 Gy to the whole thorax. Pro-apoptotic signaling was evaluated 6 weeks after radiation with or without administration of AEOL10150, a potent catalytic scavenger of reactive oxygen and nitrogen species. Results: Apoptosis was observed primarily in type I and type II pneumocytes and endothelium. Apoptosis correlated with increased PTEN expression, inhibition of downstream PI3K/AKT signaling, and increased p53 and Bax protein levels. Transforming growth factor-{beta}1, Nox4, and oxidative stress were also increased 6 weeks after radiation. Therapeutic administration of AEOL10150 suppressed pro-apoptotic signaling and dramatically reduced the number of apoptotic cells. Conclusion: Increased PTEN signaling after radiation results in apoptosis of lung parenchymal cells. We hypothesize that upregulation of PTEN is influenced by Nox4-derived oxidative stress. To our knowledge, this is the first study to highlight the role of PTEN in radiation-induced pulmonary toxicity.

  10. Amphiregulin impairs apoptosis-stimulating protein 2 of p53 overexpression-induced apoptosis in hepatoma cells.

    PubMed

    Liu, Kai; Lin, Dongdong; Ouyang, Yabo; Pang, Lijun; Guo, Xianghua; Wang, Shanshan; Zang, Yunjin; Chen, Dexi

    2017-03-01

    Overexpression of apoptosis-stimulating protein 2 of p53 (ASPP2) induces apoptotic cell death in hepatoma cells (e.g. HepG2 cells) by enhancing the transactivation activity of p53, but long-term ASPP2 overexpression fails to induce more apoptosis since activation of the epidermal growth factor/epidermal growth factor receptor/SOS1 pathway impairs the pro-apoptotic role of ASPP2. In this study, in recombinant adenovirus-ASPP2-infected HepG2 cells, ASPP2 overexpression induces amphiregulin expression in a p53-dependent manner. Although amphiregulin initially contributes to ASPP2-induced apoptosis, it eventually impairs the pro-apoptotic function of ASPP2 by activating the epidermal growth factor/epidermal growth factor receptor/SOS1 pathway, leading to apoptosis resistance. Moreover, blocking soluble amphiregulin with a neutralizing antibody also significantly increased apoptotic cell death of HepG2 cells due to treatment with methyl methanesulfonate, cisplatin, or a recombinant p53 adenovirus, suggesting that the function of amphiregulin involved in inhibiting apoptosis may be a common mechanism by which hepatoma cells escape from stimulus-induced apoptosis. Thus, our data elucidate an apoptosis-evasion mechanism in hepatocellular carcinoma and have potential implications for hepatocellular carcinoma therapy.

  11. In vivo mutagenicity of arsenite in the livers of gpt delta transgenic mice.

    PubMed

    Takumi, Shota; Aoki, Yasunobu; Sano, Tomoharu; Suzuki, Takehiro; Nohmi, Takehiko; Nohara, Keiko

    2014-01-15

    While arsenic has been classified as a Group 1 human carcinogen by the International Agency for Research on Cancer (IARC), its mutagenicity has not been fully characterized in experimental animals. The aim of this study was to assess the in vivo mutagenicity of arsenite in C57BL/6J gpt delta mice. Male gpt delta mice were given drinking water containing sodium arsenite for 3 weeks, and the hepatic genome was assayed for mutations 2 weeks later. The gpt mutation assays showed a significant increase in mutation frequency in the liver following arsenite exposure. Sequence analysis revealed that 67% of mutations detected are G:C to A:T transitions and 5% are G:C to T:A transversions in the control group, and arsenite exposure resulted in a markedly higher rate of G:C to T:A transversions (46% of mutations detected). G:C to T:A transversions have been reported to be induced following formation of 8-hydroxy-2'-deoxyguanosine (8-OHdG), a representative product that results from oxidative DNA damage. We also detected a significant increase in 8-OHdG in the livers of the mice exposed to arsenite. These results demonstrate that arsenite has mutagenicity in vivo and suggest that arsenite induces G:C to T:A transversions through oxidative-stress-induced 8-OHdG formation.

  12. Raman spectrum reveals the cell cycle arrest of Triptolide-induced leukemic T-lymphocytes apoptosis

    NASA Astrophysics Data System (ADS)

    Zhang, Daosen; Feng, Yanyan; Zhang, Qinnan; Su, Xin; Lu, Xiaoxu; Liu, Shengde; Zhong, Liyun

    2015-04-01

    Triptolide (TPL), a traditional Chinese medicine extract, possesses anti-inflammatory and anti-tumor properties. Though some research results have implicated that Triptolide (TPL) can be utilized in the treatment of leukemia, it remains controversial about the mechanism of TPL-induced leukemic T-lymphocytes apoptosis. In this study, combining Raman spectroscopic data, principal component analysis (PCA) and atomic force microscopy (AFM) imaging, both the biochemical changes and morphological changes during TPL-induced cell apoptosis were presented. In contrast, the corresponding data during Daunorubicin (DNR)-induced cell apoptosis was also exhibited. The obtained results showed that Raman spectral changes during TPL-induced cell apoptosis were greatly different from DNR-induced cell apoptosis in the early stage of apoptosis but revealed the high similarity in the late stage of apoptosis. Moreover, above Raman spectral changes were respectively consistent with the morphological changes of different stages during TPL-induced apoptosis or DNR-induced apoptosis, including membrane shrinkage and blebbing, chromatin condensation and the formation of apoptotic bodies. Importantly, it was found that Raman spectral changes with TPL-induced apoptosis or DNR-induced apoptosis were respectively related with the cell cycle G1 phase arrest or G1 and S phase arrest.

  13. Erythropoietin protects cardiac myocytes against anthracycline-induced apoptosis

    SciTech Connect

    Fu Ping; Arcasoy, Murat O. . E-mail: arcas001@mc.duke.edu

    2007-03-09

    The cardiotoxic adverse effects of anthracycline antibiotics limit their therapeutic utility as essential components of chemotherapy regimens for hematologic and solid malignancies. Here we show that the hematopoietic cytokine erythropoietin attenuates doxorubicin-induced apoptosis of primary neonatal rat ventricular cardiomyocytes in a dose-dependent manner. Erythropoietin treatment induced rapid, time-dependent phosphorylation of MAP kinases (MAPK) Erk1/2 and the phosphatidylinositol 3-kinase substrate Akt. Treatment of cardiomyocytes with inhibitors of phosphatidylinositol 3-kinase (LY294002) or Akt (Akti-1/2) abolished the protective effect of erythropoietin, whereas treatment with MAPK kinase (MEK1) inhibitor U0126 did not. Erythropoietin also induced the phosphorylation of GSK-3{beta}, a downstream target of PI3K-Akt. Because phosphorylation is known to inactivate GSK-3{beta}, we investigated whether GSK-3{beta} inhibition is cardioprotective. We found that GSK-3{beta} inhibitors SB216763 or lithium chloride blocked doxorubicin-induced cardiomyocyte apoptosis in a manner similar to erythropoietin, suggesting that GSK-3{beta} inhibition is involved in erythropoietin-mediated cardioprotection. Erythropoietin may serve as a novel cardioprotective agent against anthracycline-induced cardiotoxicity.

  14. A MALAT1/HIF-2α feedback loop contributes to arsenite carcinogenesis

    PubMed Central

    Xu, Yuan; Liu, Yi; Liu, Xinlu; Lu, Lu; Li, Jun; Wang, Qingling; Wei, Shaofeng; Shi, Le; Lu, Xiaolin; Liu, Qizhan; Zhang, Aihua

    2016-01-01

    Arsenic is well established as a human carcinogen, but the molecular mechanisms leading to arsenic-induced carcinogenesis are complex and elusive. It is also not known if lncRNAs are involved in arsenic-induced liver carcinogenesis. We have found that MALAT1, a non-coding RNA, is over-expressed in the sera of people exposed to arsenite and in hepatocellular carcinomas (HCCs), and MALAT1 has a close relation with the clinicopathological characteristics of HCC. In addition, hypoxia-inducible factor (HIF)-2α is up-regulated in HCCs, and MALAT1 and HIF-2α have a positive correlation in HCC tissues. During the malignant transformation of human hepatic epithelial (L-02) cells induced by a low concentration (2.0 μM) of arsenite, MALAT1 and HIF-2α are increased. In addition, arsenite-induced MALAT1 causes disassociation of the von Hippel-Lindau (VHL) protein from HIF-2α, therefore, alleviating VHL-mediated HIF-2α ubiquitination, which causes HIF-2α accumulation. In turn, HIF-2α transcriptionally regulates MALAT1, thus forming a positive feedback loop to ensure expression of arsenite-induced MALAT1 and HIF-2α, which are involved in malignant transformation. Moreover, MALAT1 and HIF-2α promote the invasive and metastatic capacities of arsenite-induced transformed L-02 cells and in HCC-LM3 cells. The capacities of MALAT1 and HIF-2α to promote tumor growth are validated in mouse xenograft models. In mice, arsenite induces an inflammatory response, and MALAT1 and HIF-2α are over-expressed. Together, these findings suggest that the MALAT1/HIF-2α feedback loop is involved in regulation of arsenite-induced malignant transformation. Our results not only confirm a novel mechanism involving reciprocal regulation between MALAT1 and HIF-2α, but also expand the understanding of the carcinogenic potential of arsenite. PMID:26735578

  15. Novel synthetic organosulfur compounds induce apoptosis of human leukemic cells.

    PubMed

    Wong, W W; Macdonald, S; Langler, R F; Penn, L Z

    2000-01-01

    It has been well documented that natural organosulfur compounds (OSCs) derived from plants such as garlic, onions and mahogany trees possess antiproliferative properties; however, the essential chemical features of the active OSC compounds remain unclear. To investigate the association between OSC structure and growth inhibitory activity, we synthesized novel relatives of dysoxysulfone, a natural OSC derived from the Fijian medicinal plant, Dysoxylum richii. In this study, we have examined the antiproliferative effects of these novel OSCs on a model human leukemic cell system and show that the compounds segregate into three groups. Group I, consisting of compounds A, B, G and J, did not affect either cell proliferation or the cell cycle profile of the leukemic cell lines. Group II, consisting of compounds F and H, induced the cells to undergo apoptosis from the G2/M phase of the cell cycle. Group III, consisting of compounds C, D, E and I, decreased cell proliferation and induced apoptosis throughout the cell cycle. The apoptotic agonists of Group II and III shared a common disulfide moiety, essential for leukemic cell cytotoxicity. Interestingly, Group II compounds did not affect cell viability of normal human diploid cells, suggesting the regions flanking the disulfide group contributes to the specificity of cell killing. Thus, we provide evidence that structure-activity analysis of natural products can identify novel compounds for the development of new therapeutics that can trigger apoptosis in a tumor-specific manner.

  16. Progesterone prevents radiation-induced apoptosis in breast cancer cells.

    PubMed

    Vares, Guillaume; Ory, Katherine; Lectard, Bruno; Levalois, Céline; Altmeyer-Morel, Sandrine; Chevillard, Sylvie; Lebeau, Jérôme

    2004-06-03

    Sex steroid hormones play an essential role in the control of homeostasis in the mammary gland. Although the involvement of progesterone in cellular proliferation and differentiation is well established, its exact role in the control of cell death still remains unclear. As dysregulation of the apoptotic process plays an important role in the pathogenesis of breast cancer, we investigated the regulation of apoptosis by progesterone in various breast cancer cell lines. Our results show that progesterone treatment protects against radiation-induced apoptosis. This prevention appears to be mediated by the progesterone receptor and is unrelated to p53 status. There is also no correlation with the intrinsic hormonal effect on cell proliferation, as the presence of cells in a particular phase of the cell cycle. Surprisingly, progesterone partly allows bypassing of the irradiation-induced growth arrest in G(2)/M in PgR+ cells, leading to an increase in cell proliferation after irradiation. One consequence of this effect is a higher rate of chromosome damage in these proliferating progesterone-treated cells compared to what is observed in untreated irradiated cells. We propose that progesterone, by inhibiting apoptosis and promoting the proliferation of cells with DNA damage, potentially facilitates the emergence of genetic mutations that may play a role in malignant transformation.

  17. Chestnut extract induces apoptosis in AGS human gastric cancer cells.

    PubMed

    Lee, Hyun Sook; Kim, Eun Ji; Kim, Sun Hyo

    2011-06-01

    In Korea, chestnut production is increasing each year, but consumption is far below production. We investigated the effect of chestnut extracts on antioxidant activity and anticancer effects. Ethanol extracts of raw chestnut (RCE) or chestnut powder (CPE) had dose-dependent superoxide scavenging activity. Viable numbers of MDA-MD-231 human breast cancer cells, DU145 human prostate cancer cells, and AGS human gastric cancer cells decreased by 18, 31, and 69%, respectively, following treatment with 200 µg/mL CPE for 24 hr. CPE at various concentrations (0-200 µg/mL) markedly decreased AGS cell viability and increased apoptotic cell death dose and time dependently. CPE increased the levels of cleaved caspase-8, -7, -3, and poly (ADP-ribose) polymerase in a dose-dependent manner but not cleaved caspase-9. CPE exerted no effects on Bcl-2 and Bax levels. The level of X-linked inhibitor of apoptosis protein decreased within a narrow range following CPE treatment. The levels of Trail, DR4, and Fas-L increased dose-dependently in CPE-treated AGS cells. These results show that CPE decreases growth and induces apoptosis in AGS gastric cancer cells and that activation of the death receptor pathway contributes to CPE-induced apoptosis in AGS cells. In conclusion, CPE had more of an effect on gastric cancer cells than breast or prostate cancer cells, suggesting that chestnuts would have a positive effect against gastric cancer.

  18. Tamoxifen Induces Apoptosis of Leishmania major Promastigotes in Vitro.

    PubMed

    Doroodgar, Masoud; Delavari, Mahdi; Doroodgar, Moein; Abbasi, Ali; Taherian, Ali Akbar; Doroodgar, Abbas

    2016-02-01

    Tamoxifen is an antagonist of the estrogen receptor and currently used for the treatment of breast cancer. The current treatment of cutaneous leishmaniasis with pentavalent antimony compounds is not satisfactory. Therefore, in this study, due to its antileishmanial activity, effects of tamoxifen on the growth of promastigotes and amastigotes of Leishmania major Iranian strain were evaluated in vitro. Promastigotes and amastigotes were treated with different concentrations (1, 5, 10, 20, and 50 μg/ml) and time periods (24, 48, and 72 hr) of tamoxifen. After tamoxifen treatment, MTT assay (3-[4,5-dimethylthiazol-2-yl]-2,5 biphenyl tetrazolium bromide assay) was used to determine the percentage of live parasites and Graph Pad Prism software to calculate IC50. Flow cytometry was applied to investigate the induction of tamoxifen-induced apoptosis in promastigotes. The half maximal inhibitory concentration (IC50) of tamoxifen on promastigotes was 2.6 μg/ml after 24 hr treatment. Flow cytometry analysis showed that tamoxifen induced early and late apoptosis in Leishmania promastigotes. While after 48 hr in control group the apoptosis was 2.0%, the 50 µg/L concentration of tamoxifen increased it to 59.7%. Based on the in vitro antileishmanial effect, tamoxifen might be used for leishmaniasis treatment; however, further researches on in vivo effects of tamoxifen in animal models are needed.

  19. Bisphenol A-induced apoptosis of cultured rat Sertoli cells.

    PubMed

    Iida, Hiroshi; Maehara, Kazue; Doiguchi, Masamichi; Mōri, Takayuki; Yamada, Fumio

    2003-01-01

    Bisphenol A (BPA) was examined for its effects on cultured Sertoli cells established from 18-day-old rat testes. We demonstrated that exposure of cultured Sertoli cells to BPA decreased the cell viability in a dose- and a time-dependent manner and that exposure to BPA brought about morphologic changes of the cells, such as membrane blebs, cell rounding, cytoskeletal collapse, and chromatin condensation or fragmentation, all of which conform to the morphologic criteria for apoptosis. Immunocytochemistry showed that active caspase-3, a major execution caspase, was expressed in round Sertoli cells positively labeled by the TUNEL method. Co-localization of active caspase-3 and aggregated actin fragments was also observed in the round Sertoli cells. Theses results suggest that BPA induces cell death of Sertoli cells by promoting apoptosis. Apoptosis-inducing cell death was observed in cells exposed to 150-200 microM BPA, while BPA at <100 microM had only slight cytotoxic effects on the cells.

  20. Ceramide-Induced Apoptosis in Renal Tubular Cells: A Role of Mitochondria and Sphingosine-1-Phoshate

    PubMed Central

    Ueda, Norishi

    2015-01-01

    Ceramide is synthesized upon stimuli, and induces apoptosis in renal tubular cells (RTCs). Sphingosine-1 phosphate (S1P) functions as a survival factor. Thus, the balance of ceramide/S1P determines ceramide-induced apoptosis. Mitochondria play a key role for ceramide-induced apoptosis by altered mitochondrial outer membrane permeability (MOMP). Ceramide enhances oligomerization of pro-apoptotic Bcl-2 family proteins, ceramide channel, and reduces anti-apoptotic Bcl-2 proteins in the MOM. This process alters MOMP, resulting in generation of reactive oxygen species (ROS), cytochrome C release into the cytosol, caspase activation, and apoptosis. Ceramide regulates apoptosis through mitogen-activated protein kinases (MAPKs)-dependent and -independent pathways. Conversely, MAPKs alter ceramide generation by regulating the enzymes involving ceramide metabolism, affecting ceramide-induced apoptosis. Crosstalk between Bcl-2 family proteins, ROS, and many signaling pathways regulates ceramide-induced apoptosis. Growth factors rescue ceramide-induced apoptosis by regulating the enzymes involving ceramide metabolism, S1P, and signaling pathways including MAPKs. This article reviews evidence supporting a role of ceramide for apoptosis and discusses a role of mitochondria, including MOMP, Bcl-2 family proteins, ROS, and signaling pathways, and crosstalk between these factors in the regulation of ceramide-induced apoptosis of RTCs. A balancing role between ceramide and S1P and the strategy for preventing ceramide-induced apoptosis by growth factors are also discussed. PMID:25751724

  1. Nicotine Induces Podocyte Apoptosis through Increasing Oxidative Stress

    PubMed Central

    Lan, Xiqian; Lederman, Rivka; Eng, Judith M.; Shoshtari, Seyedeh Shadafarin Marashi; Saleem, Moin A.; Malhotra, Ashwani; Singhal, Pravin C.

    2016-01-01

    Background Cigarette smoking plays an important role in the progression of chronic kidney disease (CKD). Nicotine, one of the major components of cigarette smoking, has been demonstrated to increase proliferation of renal mesangial cells. In this study, we examined the effect of nicotine on podocyte injury. Methods To determine the expression of nicotinic acetylcholine receptors (nAChR subunits) in podocytes, cDNAs and cell lysate of cultured human podocytes were used for the expression of nAChR mRNAs and proteins, respectively; and mouse renal cortical sections were subjected to immunofluorescant staining. We also studied the effect of nicotine on podocyte nephrin expression, reactive oxygen species (ROS) generation (via DCFDA loading followed by fluorometric analysis), proliferation, and apoptosis (morphologic assays). We evaluated the effect of nicotine on podocyte downstream signaling including phosphorylation of ERK1/2, JNK, and p38 and established causal relationships by using respective inhibitors. We used nAChR antagonists to confirm the role of nicotine on podocyte injury. Results Human podocytes displayed robust mRNA and protein expression of nAChR in vitro studies. In vivo studies, mice renal cortical sections revealed co-localization of nAChRs along with synaptopodin. In vitro studies, nephrin expression in podocyte was decreased by nicotine. Nicotine stimulated podocyte ROS generation; nonetheless, antioxidants such as N-acetyl cysteine (NAC) and TEMPOL (superoxide dismutase mimetic agent) inhibited this effect of nicotine. Nicotine did not modulate proliferation but promoted apoptosis in podocytes. Nicotine enhanced podocyte phosphorylation of ERK1/2, JNK, and p38, and their specific inhibitors attenuated nicotine-induced apoptosis. nAChR antagonists significantly suppressed the effects of nicotine on podocyte. Conclusions Nicotine induces podocyte apoptosis through ROS generation and associated downstream MAPKs signaling. The present study provides

  2. Histone deacetylase 6 associates with ribosomes and regulates de novo protein translation during arsenite stress.

    PubMed

    Kappeler, Kyle V; Zhang, Jack; Dinh, Thai Nho; Strom, Joshua G; Chen, Qin M

    2012-05-01

    Histone deacetylase 6 (HDAC6) is known as a cytoplasmic enzyme that regulates cell migration, cell adhesion, and degradation of misfolded proteins by deacetylating substrates such as α-tubulin and Hsp90. When HaCaT keratinocytes were exposed to 1-200μM sodium arsenite, we observed perinuclear localization of HDAC6 within 30 min. Although the overall level of HDAC6 protein did not change, sodium arsenite caused an increase of HDAC6 in ribosomal fractions. Separation of ribosomal subunits versus intact ribosomes or polysomes indicated that HDAC6 was mainly detected in 40/43S fractions containing the small ribosomal subunit in untreated cells but was associated with 40/43S and 60/80S ribosomal fractions in arsenite-treated cells. Immunocytochemistry studies revealed that arsenite caused colocalization of HDAC6 with the ribosomal large and small subunit protein L36a and S6. Both L36a and S6 were detected in the immunocomplex of HDAC6 isolated from arsenite-treated cells. The observed physical interaction of HDAC6 with ribosomes pointed to a role of HDAC6 in stress-induced protein translation. Among arsenite stress-induced proteins, de novo Nrf2 protein translation was inhibited by Tubastatin A. These data demonstrate that HDAC6 was recruited to ribosomes, physically interacted with ribosomal proteins, and regulated de novo protein translation in keratinocytes responding to arsenite stress.

  3. AIRE-induced apoptosis is associated with nuclear translocation of stress sensor protein GAPDH

    SciTech Connect

    Liiv, Ingrid; Haljasorg, Uku; Kisand, Kai; Maslovskaja, Julia; Laan, Martti; Peterson, Paert

    2012-06-22

    Highlights: Black-Right-Pointing-Pointer AIRE induces apoptosis in epithelial cells. Black-Right-Pointing-Pointer CARD domain of AIRE is sufficient for apoptosis induction. Black-Right-Pointing-Pointer AIRE induced apoptosis involves GAPDH translocation to the nuclei. Black-Right-Pointing-Pointer Deprenyl inhibits AIRE induced apoptosis. -- Abstract: AIRE (Autoimmune Regulator) has a central role in the transcriptional regulation of self-antigens in medullary thymic epithelial cells, which is necessary for negative selection of autoreactive T cells. Recent data have shown that AIRE can also induce apoptosis, which may be linked to cross-presentation of these self-antigens. Here we studied AIRE-induced apoptosis using AIRE over-expression in a thymic epithelial cell line as well as doxycycline-inducible HEK293 cells. We show that the HSR/CARD domain in AIRE together with a nuclear localization signal is sufficient to induce apoptosis. In the nuclei of AIRE-positive cells, we also found an increased accumulation of a glycolytic enzyme, glyceraldehyde-3-phosphate (GAPDH) reflecting cellular stress and apoptosis. Additionally, AIRE-induced apoptosis was inhibited with an anti-apoptotic agent deprenyl that blocks GAPDH nitrosylation and nuclear translocation. We propose that the AIRE-induced apoptosis pathway is associated with GAPDH nuclear translocation and induction of NO-induced cellular stress in AIRE-expressing cells.

  4. Knockdown of HIF-1α and IL-8 induced apoptosis of hepatocellular carcinoma triggers apoptosis of vascular endothelial cells.

    PubMed

    Choi, Sung Hoon; Park, Jun Yong; Kang, Wonseok; Kim, Seung Up; Kim, Do Young; Ahn, Sang Hoon; Ro, Simon Wonsang; Han, Kwang-Hyub

    2016-01-01

    A local hypoxic microenvironment is one of the most important characteristics of solid tumors. Hypoxia inducible factor-1α (HIF-1α) and Interleukin-8 (IL-8) activate tumor survival from hypoxic-induced apoptosis in each pathway. This study aimed to evaluate whether knockdown of HIF-1α and IL-8 induced apoptosis of the hepatocellular carcinoma (HCC) and endothelial cell lines. HCC cell lines were infected with adenovirus-expressing shRNA for HIF-1α and IL-8 and maintained under hypoxic conditions (1% O2, 24 h). The expression levels of HIF-1α and both apoptotic and growth factors were examined by real-time quantitative PCR and western blot. We also investigated apoptosis by TUNEL assay (FACS and Immunofluorescence) and measured the concentration of cytochrome C. Inhibition of HIF-1α and IL-8 up-regulated the expression of apoptotic factors while downregulating anti-apoptotic factors simultaneously. Knockdown of HIF-1α and IL-8 increased the concentration of cytochrome C and enhanced DNA fragmentation in HCC cell lines. Moreover, culture supernatant collected from the knockdown of HIF-1α and IL-8 in HCC cell lines induced apoptosis in human umbilical vein endothelial cells under hypoxia, and the expression of variable apoptotic ligand increased from HCC cell lines, time-dependently. These data suggest that adenovirus-mediated knockdown of HIF-1α and IL-8 induced apoptosis in HCC cells and triggered apoptosis of vascular endothelial cells.

  5. Deletion of the Mitochondrial Flavoprotein Apoptosis Inducing Factor (AIF) Induces β-Cell Apoptosis and Impairs β-Cell Mass

    PubMed Central

    Schulthess, Fabienne T.; Katz, Sophie; Ardestani, Amin; Kawahira, Hiroshi; Georgia, Senta; Bosco, Domenico; Bhushan, Anil; Maedler, Kathrin

    2009-01-01

    Background Apoptosis is a hallmark of β-cell death in both type 1 and type 2 diabetes mellitus. Understanding how apoptosis contributes to β-cell turnover may lead to strategies to prevent progression of diabetes. A key mediator of apoptosis, mitochondrial function, and cell survival is apoptosis inducing factor (AIF). In the present study, we investigated the role of AIF on β-cell mass and survival using the Harlequin (Hq) mutant mice, which are hypomorphic for AIF. Methodology/Principal Findings Immunohistochemical evaluation of pancreata from Hq mutant mice displayed much smaller islets compared to wild-type mice (WT). Analysis of β-cell mass in these mice revealed a greater than 4-fold reduction in β-cell mass together with an 8-fold increase in β-cell apoptosis. Analysis of cell cycle dynamics, using BrdU pulse as a marker for cells in S-phase, did not detect significant differences in the frequency of β-cells in S-phase. In contrast, double staining for phosphorylated Histone H3 and insulin showed a 3-fold increase in β-cells in the G2 phase in Hq mutant mice, but no differences in M-phase compared to WT mice. This suggests that the β-cells from Hq mutant mice are arrested in the G2 phase and are unlikely to complete the cell cycle. β-cells from Hq mutant mice display increased sensitivity to hydrogen peroxide-induced apoptosis, which was confirmed in human islets in which AIF was depleted by siRNA. AIF deficiency had no effect on glucose stimulated insulin secretion, but the impaired effect of hydrogen peroxide on β-cell function was potentiated. Conclusions/Significance Our results indicate that AIF is essential for maintaining β-cell mass and for oxidative stress response. A decrease in the oxidative phosphorylation capacity may counteract the development of diabetes, despite its deleterious effects on β-cell survival. PMID:19197367

  6. Diethanolamine alters neurogenesis and induces apoptosis in fetal mouse hippocampus

    PubMed Central

    Craciunescu, Corneliu N.; Wu, Renan; Zeisel, Steven H.

    2006-01-01

    Diethanolamine (DEA) is present in many consumer products such as shampoo. Dermal administration of DEA diminishes hepatic stores of the essential nutrient choline, and we previously reported that dietary choline deficiency during pregnancy reduces neurogenesis and increases apoptosis in the hippocampus of fetal rats and mice. Therefore, DEA could also alter brain development. Timed-pregnant C57BL/6 mice were dosed dermally from gestation day 7 through 17 with DEA at 0, 20, 80, 160, 320, and 640 mg/kg body/day. At doses of DEA > 80 mg/kg body/day, we observed decreased litter size. In fetuses (embryonic day 17) collected from dams treated dermally with 80 mg/kg body/day DEA, we observed decreased neural progenitor cell mitosis at the ventricular surface of the ventricular zone of the hippocampus [to 56±14% (SE) histone 3 (H3) phosphorylation as compared to controls; P < 0.01]. We also observed increased apoptosis in fetal hippocampus (to 170±10% of control measured using TUNEL and to 178±7% of control measured using activated caspase 3; P < 0.01). Thus, maternal exposure to DEA reduces the number of neural progenitor cells in hippocampus by two mechanisms, and this could permanently alter memory function in offspring of mothers exposed to this common ingredient of shampoos and soaps.—Craciunescu, C. N., Wu, R., Zeisel, S. H. Diethanolamine alters neurogenesis and induces apoptosis in fetal mouse hippocampus. PMID:16873886

  7. Engineered nanoparticles induce cell apoptosis: potential for cancer therapy

    PubMed Central

    Ma, Dan-Dan; Yang, Wan-Xi

    2016-01-01

    Engineered nanoparticles (ENPs) have been widely applied in industry, commodities, biology and medicine recently. The potential for many related threats to human health has been highlighted. ENPs with their sizes no larger than 100 nm are able to enter the human body and accumulate in organs such as brain, liver, lung, testes, etc, and cause toxic effects. Many references have studied ENP effects on the cells of different organs with related cell apoptosis noted. Understanding such pathways towards ENP induced apoptosis may aid in the design of effective cancer targeting ENP drugs. Such ENPs can either have a direct effect towards cancer cell apoptosis or can be used as drug delivery agents. Characteristics of ENPs, such as sizes, shape, forms, charges and surface modifications are all seen to play a role in determining their toxicity in target cells. Specific modifications of such characteristics can be applied to reduce ENP bioactivity and thus alleviate unwanted cytotoxicity, without affecting the intended function. This provides an opportunity to design ENPs with minimum toxicity to non-targeted cells. PMID:27056889

  8. Ticlopidine induced colitis: a histopathological study including apoptosis.

    PubMed Central

    Berrebi, D; Sautet, A; Flejou, J F; Dauge, M C; Peuchmaur, M; Potet, F

    1998-01-01

    AIMS: To describe ticlopidine related microscopic colitis and to assess the occurrence of apoptosis in the colon epithelium. METHODS: A series of colorectal biopsy samples from nine patients with ticlopidine related chronic diarrhoea were analysed. Biopsies were also taken from five of these patients between two and four months after ticlopidine withdrawal. The number of apoptotic cells in the crypts/mm2 (apoptotic index) was calculated using in situ labelling by terminal deoxyribonucleotidyl transferase (TdT) mediated dUTP-biotin nick end labelling (TUNEL). All specimens were matched to normal colorectal specimens from a control group of comparable age and sex distribution. RESULTS: Histological examination of the colon biopsy specimens taken from all nine patients with ticlopidine related chronic diarrhoea showed characteristic features of microscopic colitis. The histology returned to normal when ticlopidine was withdrawn. Apoptotic cells were rarely found in controls, and the mean apoptotic index was 0.53. The apoptotic index was significantly higher (16.53) in ticlopidine related colitis, but decreased dramatically to control value when ticlopidine was withdrawn. CONCLUSION: Microscopic colitis can be induced by ticlopidine and is accompanied by an increase in epithelial apoptosis. Hence, increased apoptosis might be related to drug injury or might be part of microscopic colitis. Images PMID:9659239

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

    PubMed

    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.

  10. Photodynamic therapy with Pc 4 induces apoptosis of Candida albicans.

    PubMed

    Lam, Minh; Jou, Paul C; Lattif, Ali A; Lee, Yoojin; Malbasa, Christi L; Mukherjee, Pranab K; Oleinick, Nancy L; Ghannoum, Mahmoud A; Cooper, Kevin D; Baron, Elma D

    2011-01-01

    The high prevalence of drug resistance necessitates the development of novel antifungal agents against infections caused by opportunistic fungal pathogens, such as Candida albicans. Elucidation of apoptosis in yeast-like fungi may provide a basis for future therapies. In mammalian cells, photodynamic therapy (PDT) has been demonstrated to generate reactive oxygen species, leading to immediate oxidative modifications of biological molecules and resulting in apoptotic cell death. In this report, we assess the in vitro cytotoxicity and mechanism of PDT, using the photosensitizer Pc 4, in planktonic C. albicans. Confocal image analysis confirmed that Pc 4 localizes to cytosolic organelles, including mitochondria. A colony formation assay showed that 1.0 μM Pc 4 followed by light at 2.0 J cm(-2) reduced cell survival by 4 logs. XTT (2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxyanilide) assay revealed that Pc 4-PDT impaired fungal metabolic activity, which was confirmed using the FUN-1 (2-chloro-4-[2,3-dihydro-3-methyl-(benzo-1,3-thiazol-2-yl)-methylidene]-1-phenylquinolinium iodide) fluorescence probe. Furthermore, we observed changes in nuclear morphology characteristic of apoptosis, which were substantiated by increased externalization of phosphatidylserine and DNA fragmentation following Pc 4-PDT. These data indicate that Pc 4-PDT can induce apoptosis in C. albicans. Therefore, a better understanding of the process will be helpful, as PDT may become a useful treatment option for candidiasis.

  11. The Impact of Autophagy on the Cigarette Smoke Extract-Induced Apoptosis of Bronchial Epithelial Cells

    PubMed Central

    Lee, Chang-Hoon; Lee, Kyoung-Hee; Jang, An-Hee

    2017-01-01

    Background Previous studies report that apoptosis and autophagy are involved in the pathogenesis of emphysema, and macroautophagy is one of the processes regulating the apoptosis pathway. However, few studies have evaluated whether chaperone-mediated autophagy (CMA) contributes to the regulation of apoptosis. In this study, we investigated the impact of autophagy, including both macroautophagy and CMA, on the apoptosis in bronchial epithelial cells. Methods Cigarette smoke extract (CSE) was injected intratracheally into C57BL/6 mice, and emphysema and apoptosis were evaluated in the lungs. After treatment with CSE, apoptosis, macroautophagy, and CMA were measured in BEAS2-B cells, and the impact of autophagy on the apoptosis was evaluated following knockdown of autophagy-related genes by short interfering RNAs (siRNAs). Results Intratracheal CSE injection resulted in the development of emphysema and an increase in apoptosis in mice. CSE increased the apoptosis in BEAS2-B cells, and also elevated the expression of proteins related to both macroautophagy and CMA in BEAS2-B cells. The knockdown experiment with siRNAs showed that macroautophagy increases apoptosis in BEAS2-B cells, while CMA suppresses apoptosis. Conclusion The intratracheal injection of CSE induces pulmonary emphysema and an increase in apoptosis in mice. CSE also induces apoptosis, macroautophagy, and CMA of bronchial epithelial cells. Macroautophagy and CMA regulate apoptosis in opposite directions. PMID:28119751

  12. Dioscin induces caspase-independent apoptosis through activation of apoptosis-inducing factor in breast cancer cells.

    PubMed

    Kim, Eun-Ae; Jang, Ji-Hoon; Lee, Yun-Han; Sung, Eon-Gi; Song, In-Hwan; Kim, Joo-Young; Kim, Suji; Sohn, Ho-Yong; Lee, Tae-Jin

    2014-07-01

    Dioscin, a saponin extracted from the roots of Polygonatum zanlanscianense, shows several bioactivities such as antitumor, antifungal, and antiviral properties. Although, dioscin is already known to induce cell death in variety cancer cells, the molecular basis for dioscin-induced cell death was not definitely known in cancer cells. In this study, we found that dioscin treatment induced cell death in dose-dependent manner in breast cancer cells such as MDA-MB-231, MDA-MB-453, and T47D cells. Dioscin decreased expressions of Bcl-2 and cIAP-1 proteins, which were down-regulated at the transcriptional level. Conversely, Mcl-1 protein level was down-regulated by facilitating ubiquitin/proteasome-mediated Mcl-1 degradation in dioscin-treated cells. Pretreatment with z-VAD fails to attenuate dioscin-induced cell death as well as caspase-mediated events such as cleavages of procaspase-3 and PARP. In addition, dioscin treatment increased the population of annexin V positive cells and induced DNA fragmentation in a dose-dependent manner in MDA-MB-231 cells. Furthermore, apoptosis inducing factor (AIF) was released from the mitochondria and translocated to the nucleus. Suppression in AIF expression by siRNA reduced dioscin-induced apoptosis in MDA-MB-231 cells. Taken together, our results demonstrate that dioscin-induced cell death was mediated via AIF-facilitating caspase-independent pathway as well as down-regulating anti-apoptotic proteins such as Bcl-2, cIAP-1, and Mcl-1 in breast cancer cells.

  13. Microbial Oxidation of Arsenite in a Subarctic Environment: Diversity of Arsenite Oxidase Genes and Identification of a Psychrotolerant Arsenite Oxidiser

    SciTech Connect

    Osborne, T.; Jamieson, H; Hudson-Edwards, K; Nordstrom, D; Walker, S; Ward, S; Santini, J

    2010-01-01

    Arsenic is toxic to most living cells. The two soluble inorganic forms of arsenic are arsenite (+3) and arsenate (+5), with arsenite the more toxic. Prokaryotic metabolism of arsenic has been reported in both thermal and moderate environments and has been shown to be involved in the redox cycling of arsenic. No arsenic metabolism (either dissimilatory arsenate reduction or arsenite oxidation) has ever been reported in cold environments (i.e. < 10 C). Our study site is located 512 kilometres south of the Arctic Circle in the Northwest Territories, Canada in an inactive gold mine which contains mine waste water in excess of 50 mM arsenic. Several thousand tonnes of arsenic trioxide dust are stored in underground chambers and microbial biofilms grow on the chamber walls below seepage points rich in arsenite-containing solutions. We compared the arsenite oxidisers in two subsamples (which differed in arsenite concentration) collected from one biofilm. 'Species' (sequence) richness did not differ between subsamples, but the relative importance of the three identifiable clades did. An arsenite-oxidizing bacterium (designated GM1) was isolated, and was shown to oxidise arsenite in the early exponential growth phase and to grow at a broad range of temperatures (4-25 C). Its arsenite oxidase was constitutively expressed and functioned over a broad temperature range. The diversity of arsenite oxidisers does not significantly differ from two subsamples of a microbial biofilm that vary in arsenite concentrations. GM1 is the first psychrotolerant arsenite oxidiser to be isolated with the ability to grow below 10 C. This ability to grow at low temperatures could be harnessed for arsenic bioremediation in moderate to cold climates.

  14. Apoptosis in immunocytes induced by several types of pesticides.

    PubMed

    Fukuyama, Tomoki; Tajima, Yukari; Ueda, Hideo; Hayashi, Koichi; Shutoh, Yasufumi; Harada, Takanori; Kosaka, Tadashi

    2010-03-01

    Several types of pesticides, such as organophosphates and organochlorines, can induce thymocyte apoptosis, resulting in thymic atrophy and predisposing the highly sensitive fetal immune system to loss of tolerance to self-antigens and subsequent increased risk for autoimmune disease and allergies. In the studies here, mouse primary thymocytes and a human acute T-cell leukemia cell line (J45.01) were employed to examine potential thymocyte apoptosis induced by several types of chemicals, including several commonly-used pesticides. Thymocytes and J45.01 cells were treated for 4 or 8 hr with varying doses of metamidophos, parathion, PNMC, or methoxychlor; dexamethasone was used as a positive control. Apoptosis, cell viability, the proportion of Annexin-V+ cells, the activities of caspases 3/7, 8, and 9, and the levels of DNA fragmentation in both the J45.01 cells and thymocytes were then examined. The results here show that with both cell types, there was an increase in the proportion of annexin-V+ cells and levels of DNA fragmentation following exposure to parathion, PNMC, methoxychlor, or dexamethasone (positive control); however, the levels of sensitivity appeared to differ between the cell types. Furthermore, caspase-7 and -8 activities also differed between the J45.01 cells and thymocytes when treated with PNMC, methoxychlor, or dexamethasone. A more precise characterization of these inter-cellular differences is the logical next step in our studies of the effects of these (and other) pesticides on immune cell integrity. These specific types of follow-on mechanistic experiments are currently underway in our laboratories.

  15. Role of apoptosis-inducing factor, proline dehydrogenase, and NADPH oxidase in apoptosis and oxidative stress

    PubMed Central

    Natarajan, Sathish Kumar; Becker, Donald F

    2012-01-01

    Flavoproteins catalyze a variety of reactions utilizing flavin mononucleotide or flavin adenine dinucleotide as cofactors. The oxidoreductase properties of flavoenzymes implicate them in redox homeostasis, oxidative stress, and various cellular processes, including programmed cell death. Here we explore three critical flavoproteins involved in apoptosis and redox signaling, ie, apoptosis-inducing factor (AIF), proline dehydrogenase, and NADPH oxidase. These proteins have diverse biochemical functions and influence apoptotic signaling by unique mechanisms. The role of AIF in apoptotic signaling is two-fold, with AIF changing intracellular location from the inner mitochondrial membrane space to the nucleus upon exposure of cells to apoptotic stimuli. In the mitochondria, AIF enhances mitochondrial bioenergetics and complex I activity/assembly to help maintain proper cellular redox homeostasis. After translocating to the nucleus, AIF forms a chromatin degrading complex with other proteins, such as cyclophilin A. AIF translocation from the mitochondria to the nucleus is triggered by oxidative stress, implicating AIF as a mitochondrial redox sensor. Proline dehydrogenase is a membrane-associated flavoenzyme in the mitochondrion that catalyzes the rate-limiting step of proline oxidation. Upregulation of proline dehydrogenase by the tumor suppressor, p53, leads to enhanced mitochondrial reactive oxygen species that induce the intrinsic apoptotic pathway. NADPH oxidases are a group of enzymes that generate reactive oxygen species for oxidative stress and signaling purposes. Upon activation, NADPH oxidase 2 generates a burst of superoxide in neutrophils that leads to killing of microbes during phagocytosis. NADPH oxidases also participate in redox signaling that involves hydrogen peroxide-mediated activation of different pathways regulating cell proliferation and cell death. Potential therapeutic strategies for each enzyme are also highlighted. PMID:22593641

  16. Human Immunodeficiency Virus Type 1 Vpr Induces Apoptosis through Caspase Activation

    PubMed Central

    Stewart, Sheila A.; Poon, Betty; Song, Joo Y.; Chen, Irvin S. Y.

    2000-01-01

    Human immunodeficiency virus type 1 (HIV-1) Vpr is a 96-amino-acid protein that is found associated with the HIV-1 virion. Vpr induces cell cycle arrest at the G2/M phase of the cell cycle, and this arrest is followed by apoptosis. We examined the mechanism of Vpr-induced apoptosis and found that HIV-1 Vpr-induced apoptosis requires the activation of a number of cellular cysteinyl aspartate-specific proteases (caspases). We demonstrate that ectopic expression of anti-apoptotic viral proteins, which inhibit caspase activity, and addition of synthetic peptides, which represent caspase cleavage sites, can inhibit Vpr-induced apoptosis. Finally, inhibition of caspase activity and subsequent inhibition of apoptosis results in increased viral expression, suggesting that therapeutic strategies aimed at reducing Vpr-induced apoptosis in vivo require careful consideration. PMID:10708425

  17. Aloe-emodin-induced apoptosis in human gastric carcinoma cells.

    PubMed

    Chen, Sheng-Hsuan; Lin, Kai-Yuan; Chang, Chun-Chao; Fang, Chia-Lang; Lin, Chih-Ping

    2007-11-01

    The purpose of this study was to investigate the anticancer effect of aloe-emodin, an anthraquinone compound present in the leaves of Aloe vera, on two distinct human gastric carcinoma cell lines, AGS and NCI-N87. We demonstrate that aloe-emodin induced cell death in a dose- and time-dependent manner. Noteworthy is that the AGS cells were generally more sensitive than the NCI-N87 cells. Aloe-emodin caused the release of apoptosis-inducing factor and cytochrome c from mitochondria, followed by the activation of caspase-3, leading to nuclear shrinkage and apoptosis. In addition, exposure to aloe-emodin suppressed the casein kinase II activity in a time-dependent manner and was accompanied by a reduced phosphorylation of Bid, a downstream substrate of casein kinase II and a pro-apoptotic molecule. These preclinical studies suggest that aloe-emodin represents a suitable and novel chemotherapeutic drug candidate for the treatment of human gastric carcinoma.

  18. Lead Induces Apoptosis and Histone Hyperacetylation in Rat Cardiovascular Tissues.

    PubMed

    Xu, Li-Hui; Mu, Fang-Fang; Zhao, Jian-Hong; He, Qiang; Cao, Cui-Li; Yang, Hui; Liu, Qi; Liu, Xue-Hui; Sun, Su-Ju

    2015-01-01

    Acute and chronic lead (Pb) exposure might cause hypertension and cardiovascular diseases. The purpose of this study was to evaluate the effects of early acute exposure to Pb on the cellular morphology, apoptosis, and proliferation in rats and to elucidate the early mechanisms involved in the development of Pb-induced hypertension. Very young Sprague-Dawley rats were allowed to drink 1% Pb acetate for 12 and 40 days. Western blot analysis indicated that the expression of proliferating cell nuclear antigen (PCNA) decreased in the tissues of the abdominal and thoracic aortas and increased in the cardiac tissue after 12 and 40 days of Pb exposure, respectively. Bax was upregulated and Bcl-2 was downregulated in vascular and cardiac tissues after 40 days of Pb exposure. In addition, an increase in caspase-3 activity was observed after 40 days of exposure to Pb. In terms of morphology, we found that the internal elastic lamina (IEL) of aorta lost the original curve and the diameter of cardiac cell was enlarged after 40 days. Furthermore, the exposure led to a marked increase in acetylated histone H3 levels in the aortas and cardiac tissue after 12 and 40 days, than that in the control group. These findings indicate that Pb might increase the level of histone acetylation and induce apoptosis in vascular and cardiac tissues. However, the mechanism involved need to be further investigated.

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

    PubMed Central

    Lu, Xinpei; He, Guangyuan; Ostrikov, Kostya

    2014-01-01

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

  20. Arsenite exposure accelerates aging process regulated by the transcription factor DAF-16/FOXO in Caenorhabditis elegans.

    PubMed

    Yu, Chan-Wei; How, Chun Ming; Liao, Vivian Hsiu-Chuan

    2016-05-01

    Arsenic is a known human carcinogen and high levels of arsenic contamination in food, soils, water, and air are of toxicology concerns. Nowadays, arsenic is still a contaminant of emerging interest, yet the effects of arsenic on aging process have received little attention. In this study, we investigated the effects and the underlying mechanisms of chronic arsenite exposure on the aging process in Caenorhabditis elegans. The results showed that prolonged arsenite exposure caused significantly decreased lifespan compared to non-exposed ones. In addition, arsenite exposure (100 μM) caused significant changes of age-dependent biomarkers, including a decrease of defecation frequency, accumulations of intestinal lipofuscin and lipid peroxidation in an age-dependent manner in C. elegans. Further evidence revealed that intracellular reactive oxygen species (ROS) level was significantly increased in an age-dependent manner upon 100 μM arsenite exposure. Moreover, the mRNA levels of transcriptional makers of aging (hsp-16.1, hsp-16.49, and hsp-70) were increased in aged worms under arsenite exposure (100 μM). Finally, we showed that daf-16 mutant worms were more sensitive to arsenite exposure (100 μM) on lifespan and failed to induce the expression of its target gene sod-3 in aged daf-16 mutant under arsenite exposure (100 μM). Our study demonstrated that chronic arsenite exposure resulted in accelerated aging process in C. elegans. The overproduction of intracellular ROS and the transcription factor DAF-16/FOXO play roles in mediating the accelerated aging process by arsenite exposure in C. elegans. This study implicates a potential ecotoxicological and health risk of arsenic in the environment.

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

    SciTech Connect

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

    2007-05-25

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

  2. Daily variations in colchicine-induced apoptosis in duodenal crypts.

    PubMed

    Norma, V González; Badrán, Amado F; Barbeito, Claudio G

    2005-01-01

    Apoptotic cell death can be induced by several agents, among them colchicine, a microtubule disrupting-drug that affects continuously renewing cell populations, such as the intestinal crypt enterocytes. The objectives of this investigation were (1) to confirm in vivo colchicines-inductive effect and (2) to determine the existence of 24 h variations in the crypt enterocytes apoptotic indices. The study was done on C3H/S male adult mice housed under standardized conditions. Starting at midnight until the end of a circadian period, subgroups of mice were sacrificed after having been injected with colchicine or saline i.p. 4h beforehand. Duodenal samples were processed for hematoxylin-eosin staining and TUNEL technique. In order to score the number of apoptosis, the longitudinal sections of the crypts were divided into three regions comprised, respectively, of tiers 1-4, 5-12, and 13-20, proceeding from the bottom to the top of the crypt. Values of each lot were expressed as mean +/- SEM. A highly significant statistical difference in apoptotic indices was found for colchicine-treated animals. The 24 h curve for colchicine-induced apoptosis displayed qualitative and quantitative differences compared to other inducer agents. Highest apoptotic indices were found in the deepest crypt regions. Daily variations were observed in all the crypt sectors of the colchicine-treated animals and in tiers 5-12 of the saline controls. The present work demonstrates that the colchicine cytotoxicity due to its apoptotic-inducing effect depends on the dosing time during the 24 h in this mouse strain.

  3. The Effect of Selenium on the Cd-Induced Apoptosis via NO-Mediated Mitochondrial Apoptosis Pathway in Chicken Liver.

    PubMed

    Zhang, Runxiang; Yi, Ran; Bi, Yanju; Xing, Lu; Bao, Jun; Li, Jianhong

    2017-01-06

    Cd-induced apoptosis and the protective effects of Se against Cd-induced injury have been reported in previous studies. However, little is known regarding the effects of Cd-induced apoptosis in hepatic cells and the antagonistic effects of Se on Cd in poultry. In the present study, 128 healthy 31-week-old laying hens were randomly divided into four groups, which were fed basic diets, with the addition of Se (Na2SeO3, 2 mg/kg), Cd (CdCl2, 150 mg/kg), or Se + Cd (150 mg/kg of CdCl2 and 2 mg/kg of Na2SeO3) for 90 days. Ultrastructural changes, nitric oxide (NO) concentrations, inducible nitric oxide synthase (iNOS) activities, results of the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay of apoptosis, and the expression of iNOS and apoptosis-related genes in livers were determined. It was observed that Cd treatment significantly increased the concentrations of NO and iNOS activity in chicken livers. The production of excessive NO initiated the mitochondrial apoptotic pathway. Exposure to Cd increased the mRNA and the protein expression levels of iNOS, caspase-3, Bax, p53, and Cyt-c. Furthermore, the ratio of Bax/Bcl-2 increased, while the expression of Bcl-2 decreased. Treatment with Se significantly alleviated Cd-induced apoptosis in chicken livers, as evidenced by a reduction in the production of NO, iNOS activity, the number of apoptotic cells, and mRNA and protein expression levels of iNOS, caspase-3, Bax, and Cyt-c. It indicated that Cd induced NO-mediated apoptosis through the mitochondrial apoptotic pathway and Se exerted antagonizing effects. The present study provides new insights as to how Se affects Cd-induced toxicity in the chicken liver.

  4. A bioluminescent arsenite biosensor designed for inline water analyzer.

    PubMed

    Prévéral, Sandra; Brutesco, Catherine; Descamps, Elodie C T; Escoffier, Camille; Pignol, David; Ginet, Nicolas; Garcia, Daniel

    2017-01-01

    Whole-cell biosensors based on the reporter gene system can offer rapid detection of trace levels of organic or metallic compounds in water. They are well characterized in laboratory conditions, but their transfer into technological devices for the surveillance of water networks remains at a conceptual level. The development of a semi-autonomous inline water analyzer stumbles across the conservation of the bacterial biosensors over a period of time compatible with the autonomy requested by the end-user while maintaining a satisfactory sensitivity, specificity, and time response. We focused here on assessing the effect of lyophilization on two biosensors based on the reporter gene system and hosted in Escherichia coli. The reporter gene used here is the entire bacterial luciferase lux operon (luxCDABE) for an autonomous bioluminescence emission without the need to add any substrate. In the cell-survival biosensor that is used to determine the overall fitness of the bacteria when mixed with the water sample, lux expression is driven by a constitutive E. coli promoter PrpoD. In the arsenite biosensor, the arsenite-inducible promoter P ars involved in arsenite resistance in E. coli controls lux expression. Evaluation of the shelf life of these lyophilized biosensors kept at 4 °C over a year evidenced that about 40 % of the lyophilized cells can be revived in such storage conditions. The performances of the lyophilized biosensor after 7 months in storage are maintained, with a detection limit of 0.2 μM arsenite for a response in about an hour with good reproducibility. These results pave the way to the use in tandem of both biosensors (one for general toxicity and one for arsenite contamination) as consumables of an autonomous analyzer in the field.

  5. Betulin induces reactive oxygen species-dependent apoptosis in human gastric cancer SGC7901 cells.

    PubMed

    Li, Yang; Liu, Xiaokang; Jiang, Dan; Lin, Yingjia; Wang, Yushi; Li, Qing; Liu, Linlin; Jin, Ying-Hua

    2016-09-01

    Betulin, an abundant natural compound, significantly inhibited the cell viability of advanced human gastric cancer SGC7901 cells. Mechanism study demonstrated that betulin induced apoptosis through mitochondrial Bax and Bak accumulation-mediated intrinsic apoptosis pathway. Downregulation of the anti-apoptosis proteins Bcl-2 and XIAP was involved during betulin-induced cell apoptosis. Reactive oxygen species (ROS) was generated in cells after betulin treatment in a time- and dose-dependent manner. Addition of antioxidant N-acetyl-L-cysteine (NAC) significantly attenuated betulin-induced ROS generation as well as Bcl-2 and XIAP downregulation. The mitochondrial accumulation of Bax and Bak, as well as caspase activity, was also remarkably inhibited by NAC treatment, indicating that ROS are important signaling intermediates that lead to betulin-induced apoptosis by modulating multiple apoptosis-regulating proteins in SGC7901 cells.

  6. Regulation of DNA damage-induced apoptosis by the c-Abl tyrosine kinase

    PubMed Central

    Yuan, Zhi-Min; Huang, Yinyin; Ishiko, Takatoshi; Kharbanda, Surender; Weichselbaum, Ralph; Kufe, Donald

    1997-01-01

    Activation of the c-Abl protein tyrosine kinase by certain DNA-damaging agents contributes to down-regulation of Cdk2 and G1 arrest by a p53-dependent mechanism. The present work investigates the potential role of c-Abl in apoptosis induced by DNA damage. Transient transfection studies with wild-type, but not kinase-inactive, c-Abl demonstrate induction of apoptosis. Cells that stably express inactive c-Abl exhibit resistance to ionizing radiation-induced loss of clonogenic survival and apoptosis. Cells null for c-abl are also impaired in the apoptotic response to ionizing radiation. We further show that cells deficient in p53 undergo apoptosis in response to expression of c-Abl and exhibit decreases in radiation-induced apoptosis when expressing inactive c-Abl. These findings suggest that c-Abl kinase regulates DNA damage-induced apoptosis. PMID:9037071

  7. [X-ray irradiation induces apoptosis of mouse GC1 sperm cells via nuclear translocation of apoptosis-inducing factor].

    PubMed

    Yang, Huiying; Ding, Jingbin; Wang, Zhijun; Ding, Juan; Xia, Xinshe; Zhao, Wei

    2017-03-01

    Objective To study the effect of X-ray irradiation on the localization of apoptosis inducing factor (AIF) in mouse GC1 sperm cells. Methods After GC1 cells were treated with 0, 3, 6 and 9 Gy X irradiation, BrdU incorporation assay was performed to detect the proliferation of GC1 cells. Forty-eight hours after irradiation, the nuclear condensation was observed by DAPI staining. The subcellular localization of AIF was showed using the immunofluorescence staining, both in the whole cell extracts and in nuclear extracts, and the expression levels of AIF were detected using Western blot analysis. Results With the increase of X-ray irradiation dose, the proliferation of GC1 cells significantly decreased, and the activity of cells was weakened. After 6 Gy irradiation, in nuclear extracts, but not in the whole cell extracts, the protein AIF was upregulated significantly. It meant the nuclear translocation of protein AIF. Conclusion X-ray irradiation induces the apoptosis of mouse GC1 sperm cells, meanwhile, the nuclear translocation of AIF occurs.

  8. Deficiency of the Bax gene attenuates denervation-induced apoptosis

    PubMed Central

    Siu, P. M.; Alway, S. E.

    2015-01-01

    Apoptosis has been implicated in mediating denervation-induced muscle wasting. In this study we determined the effect of interference of apoptosis on muscle wasting during denervation by using mice genetically deficient in pro-apoptotic Bax. After denervation, muscle wasting was evident in both wild-type and Bax−/− muscles but reduction of muscle weight was attenuated in Bax−/− mice. Apoptotic DNA fragmentation increased in wild-type denervated muscles whereas there was no statistical increase in DNA fragmentation in denervated muscles from Bax−/− mice. Mitochondrial AIF and Smac/DIABLO releases and Bcl-2, p53 and HSP27 increased whereas XIAP and MnSOD decreased to a similar extent in muscles from wild-type and Bax−/− mice following denervation. Mitochondrial cytochrome c release was elevated in denervated muscles from wild-type mice but the increase was suppressed in muscles from Bax−/− mice. Increases in caspase-3 and -9 activities and oxidative stress markers H2O2, MDA/4-HAE and nitrotyrosine were all evident in denervated muscles from wild-type mice but these changes were absent in muscles from Bax−/− mice. Moreover, ARC increased exclusively in denervated Bax−/− muscle. Our data indicate that under conditions of denervation, pro-apoptotic signalling is suppressed and muscle wasting is attenuated when the Bax gene is lacking. These findings suggest that interventions targeting apoptosis may be valuable in ameliorating denervation-associated pathologic muscle wasting in certain neuromuscular disorders that involve partial or full denervation. PMID:16763784

  9. Prolactin Induces Apoptosis of Lactotropes in Female Rodents

    PubMed Central

    Ferraris, Jimena; Zárate, Sandra; Jaita, Gabriela; Boutillon, Florence; Bernadet, Marie; Auffret, Julien; Seilicovich, Adriana; Binart, Nadine; Pisera, Daniel

    2014-01-01

    Anterior pituitary cell turnover occurring during female sexual cycle is a poorly understood process that involves complex regulation of cell proliferation and apoptosis by multiple hormones. In rats, the prolactin (PRL) surge that occurs at proestrus coincides with the highest apoptotic rate. Since anterior pituitary cells express the prolactin receptor (PRLR), we aimed to address the actual role of PRL in the regulation of pituitary cell turnover in cycling females. We showed that acute hyperprolactinemia induced in ovariectomized rats using PRL injection or dopamine antagonist treatment rapidly increased apoptosis and decreased proliferation specifically of PRL producing cells (lactotropes), suggesting a direct regulation of these cell responses by PRL. To demonstrate that apoptosis naturally occurring at proestrus was regulated by transient elevation of endogenous PRL levels, we used PRLR-deficient female mice (PRLRKO) in which PRL signaling is totally abolished. According to our hypothesis, no increase in lactotrope apoptotic rate was observed at proestrus, which likely contributes to pituitary tumorigenesis observed in these animals. To decipher the molecular mechanisms underlying PRL effects, we explored the isoform-specific pattern of PRLR expression in cycling wild type females. This analysis revealed dramatic changes of long versus short PRLR ratio during the estrous cycle, which is particularly relevant since these isoforms exhibit distinct signaling properties. This pattern was markedly altered in a model of chronic PRLR signaling blockade involving transgenic mice expressing a pure PRLR antagonist (TGΔ1–9-G129R-hPRL), providing evidence that PRL regulates the expression of its own receptor in an isoform-specific manner. Taken together, these results demonstrate that i) the PRL surge occurring during proestrus is a major proapoptotic signal for lactotropes, and ii) partial or total deficiencies in PRLR signaling in the anterior pituitary may result

  10. [Advances in Parvovirus Non-structural Protein NS1 Induced Apoptosis].

    PubMed

    Tu, Mengyu; Liu, Fei; Chen, Shun; Wang, Mingshu; Cheng, Anchun

    2015-11-01

    Until now, more than seventeen parvovirus have been reported which can infect mammals and poultries. The infected cells appeared different properties of apoptosis and death, present a typical cytopathic effect. NS1 is a major nonstructural protein of parvovirus, with a conservative structure and function, which plays an important role in the viral life cycle. In addition to the influence on viral replication, the NS1 also participates in apoptosis induced by viruses. Parvovirus induced apoptosis which is mainly mediated by mitochondrial pathway, this review summarized the latest research progresses of parvovirus induced apoptosis.

  11. Gene expression profiling analysis reveals arsenic-induced cell cycle arrest and apoptosis in p53-proficient and p53-deficient cells through differential gene pathways

    SciTech Connect

    Yu Xiaozhong Robinson, Joshua F.; Gribble, Elizabeth; Hong, Sung Woo; Sidhu, Jaspreet S.; Faustman, Elaine M.

    2008-12-15

    Arsenic (As) is a well-known environmental toxicant and carcinogen as well as an effective chemotherapeutic agent. The underlying mechanism of this dual capability, however, is not fully understood. Tumor suppressor gene p53, a pivotal cell cycle checkpoint signaling protein, has been hypothesized to play a possible role in mediating As-induced toxicity and therapeutic efficiency. In this study, we found that arsenite (As{sup 3+}) induced apoptosis and cell cycle arrest in a dose-dependent manner in both p53{sup +/+} and p53{sup -/-} mouse embryonic fibroblasts (MEFs). There was, however, a distinction between genotypes in the apoptotic response, with a more prominent induction of caspase-3 in the p53{sup -/-} cells than in the p53{sup +/+} cells. To examine this difference further, a systems-based genomic analysis was conducted comparing the critical molecular mechanisms between the p53 genotypes in response to As{sup 3+}. A significant alteration in the Nrf2-mediated oxidative stress response pathway was found in both genotypes. In p53{sup +/+} MEFs, As{sup 3+} induced p53-dependent gene expression alterations in DNA damage and cell cycle regulation genes. However, in the p53{sup -/-} MEFs, As{sup 3+} induced a significant up-regulation of pro-apoptotic genes (Noxa) and down-regulation of genes in immune modulation. Our findings demonstrate that As-induced cell death occurs through a p53-independent pathway in p53 deficient cells while apoptosis induction occurs through p53-dependent pathway in normal tissue. This difference in the mechanism of apoptotic responses between the genotypes provides important information regarding the apparent dichotomy of arsenic's dual mechanisms, and potentially leads to further advancement of its utility as a chemotherapeutic agent.

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

    PubMed Central

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

    2016-01-01

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

  13. Autophagy Protects from Raddeanin A-Induced Apoptosis in SGC-7901 Human Gastric Cancer Cells

    PubMed Central

    Liu, Shen-lin; Fang, Liang-hua; Zhou, Jin-yong; Wu, Jian; Xi, Song-yang; Chen, Yan; Zhang, Ying-ying; Xu, Song

    2016-01-01

    Raddeanin A (RA) is an extractive from Anemone raddeana Regel, a traditional Chinese medicine. The aim of this study is to assess the efficacy of RA against human gastric cancer (GC) cells (SGC-7901) and explore its mechanism. MTT assay showed that RA inhibition of proliferation of SGC-7901 cells increased in a dose-dependent manner. Flow cytometry analysis and Hoechst 33258 staining showed that RA induced apoptosis on SGC-7901 cells. Meanwhile, it induced autophagy. Western blotting analysis showed that the RA induces apoptosis and autophagy by activating p38 MAPK pathway and inhibiting mTOR pathway. Further studies showed that autophagy inhibition could protect from RA-induced apoptosis in SGC-7901 cells. In conclusion, RA can induce SGC-7901 cell apoptosis and autophagy by activating p38 MAPK pathway. And autophagy can protect SGC-7901 cells from apoptosis induced by RA. PMID:27974905

  14. Interaction between various resistance modifiers and apoptosis inducer 12H-benzo[alpha]phenothiazine.

    PubMed

    Mucsi, Ilona; Varga, Andreas; Kawase, Masami; Motohashi, Noboru; Molnar, Joseph

    2002-01-01

    The effect of some resistance modifiers on apoptosis induction by a benzo[alpha]phenothiazine derivative was studied on the L5178Y mouse lymphoma cells (parent) and its multidrug resistant (MDR) subline. For evaluation of apoptosis the cells were stained with FITC-labelled annexin V and propidium iodide and the results were analysed by flow cytometry. 12H-benzo[alpha]phenothiazine [M627] induced apoptosis both in the parent cells and in the MDR cells. The apoptosis induction by [M627] was not affected significantly by post- or pre-treatment with resistance modifiers, while in the cells treated by (+/-)-verapamil before and after apoptosis induction with [M627], the apoptosis was somewhat higher. The resistance modifier compounds alone also induced apoptosis and it was slightly higher in the parent cells than its MDR1/A gene-transformed subline.

  15. Endonucleases induced TRAIL-insensitive apoptosis in ovarian carcinoma cells

    SciTech Connect

    Geel, Tessa M.; Meiss, Gregor; Gun, Bernardina T. van der; Kroesen, Bart Jan; Leij, Lou F. de; Zaremba, Mindaugas; Silanskas, Arunas; Kokkinidis, Michael; Ruiters, Marcel H.; McLaughlin, Pamela M.; Rots, Marianne G.

    2009-09-10

    TRAIL induced apoptosis of tumor cells is currently entering phase II clinical settings, despite the fact that not all tumor types are sensitive to TRAIL. TRAIL resistance in ovarian carcinomas can be caused by a blockade upstream of the caspase 3 signaling cascade. We explored the ability of restriction endonucleases to directly digest DNA in vivo, thereby circumventing the caspase cascade. For this purpose, we delivered enzymatically active endonucleases via the cationic amphiphilic lipid SAINT-18{sup Registered-Sign }:DOPE to both TRAIL-sensitive and insensitive ovarian carcinoma cells (OVCAR and SKOV-3, respectively). Functional nuclear localization after delivery of various endonucleases (BfiI, PvuII and NucA) was indicated by confocal microscopy and genomic cleavage analysis. For PvuII, analysis of mitochondrial damage demonstrated extensive apoptosis both in SKOV-3 and OVCAR. This study clearly demonstrates that cellular delivery of restriction endonucleases holds promise to serve as a novel therapeutic tool for the treatment of resistant ovarian carcinomas.

  16. Evidence that FTY720 induces rat thymocyte apoptosis.

    PubMed

    Isoyama, Naohito; Takai, Kimio; Tsuchida, Masahiro; Matsumura, Masafumi; Naito, Katsusuke

    2006-04-01

    FTY720, a novel immunomodulator with the potential to improve immunosuppressive therapy after organ transplantation, is currently under clinical investigation. FTY720 drastically decreases blood lymphocytes, especially T cells, accelerating lymphocyte homing to secondary lymphoid organs. However, its immunosuppressive effects remain unknown. We investigated these effects in rat thymocytes. Rats were intramuscularly injected with 10mg/kg/day FTY720 or saline for 7days. Thymuses were removed on days 0, 1, 3, 5, 7 and 14 after treatment. Three-color analysis was performed with a flow cytofluorometer. Apoptotic nuclei in the tissue sections were identified by TUNEL. Genomic DNA was then extracted and samples were electrophoresed on 2.0% agarose gel. FTY720 reduced the total number of thymocytes and, with time, significantly reduced the percentage of CD4+8+ TCRalphabeta(negative/low) thymocytes. Light microscopy of thymuses of FTY720-treated rats revealed obvious reductions in the size of the cortical region. TUNEL analysis showed that FTY720 induced thymocyte apoptosis in the cortical region. Furthermore, DNA fragmentation was observed in thymocytes treated with FTY720, indicating thymocyte apoptosis. FTY720 reduced the number of CD4+8+ thymocytes before TCRalphabeta expression resulting in impaired thymocyte differentiation and maturation. This might be an immunosuppressive effect of FTY720.

  17. PDT-induced apoptosis in arterial smooth muscles cells

    NASA Astrophysics Data System (ADS)

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

    1995-03-01

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

  18. Porcine JAB1 significantly enhances apoptosis induced by staurosporine

    PubMed Central

    Jiang, P; Wang, J; Kang, Z; Li, D; Zhang, D

    2013-01-01

    c-Jun activation domain-binding protein-1 (JAB1), also known as the subunit 5 of the COP9 signalosome, is a multifunctional protein that regulates cell proliferation, apoptosis and oncogenesis by interacting with and subsequently degrading a large number of proteins. Although human JAB1 (hJAB1) has been studied for a long time, studies on porcine JAB1 (pJAB1) have never been reported. In the present study, we cloned and characterized the pJAB1 gene. The genomic structure of the pJAB1 gene was determined. The open-reading frame of pJAB1 encoded 334 amino acids. The deduced amino acid sequence was highly similar to homologs in other species. Furthermore, the tertiary structure analysis and phylogenetic analysis indicated that JAB1 was highly conservative among species. pJAB1 may interact with several proteins according to protein–protein interactions analysis. In addition, pJAB1 was found to be universally expressed in porcine tissues. Subcellular localization analysis showed that GFP–pJAB1 fusion protein distributed specifically in the cytoplasm. Flow cytometric analysis proved that pJAB1 significantly enhanced apoptosis induced by staurosporine, which at least partially depended on the activation of caspase-9 and caspase-3. This study is useful for understanding the function of pJAB1 and offers a potential molecular model for the investigation of diseases related to hJAB1. PMID:24091666

  19. Distinct patterns of cleavage and translocation of cell cycle control proteins in CD95-induced and p53-induced apoptosis.

    PubMed Central

    Park, Weon Seo; Jung, Kyeong Cheon; Chung, Doo Hyun; Nam, Woo-Dong; Choi, Won Jin; Bae, Youngmee

    2003-01-01

    Apoptotic cell death induced by p53 occurs at a late G1 cell cycle checkpoint termed the restriction (R) point, and it has been proposed that p53-induced apoptosis causes upregulation of CD95. However, as cells with defective in CD95 signaling pathway are still sensitive to p53-induced apoptosis, CD95 cannot be the sole factor resulting in apoptosis. In addition, unlike p53-induced apoptosis, the relationship between CD95-mediated apoptosis and the cell cycle is not clearly understood. It would therefore be worth investigating whether CD95-mediated cell death is pertinent with p53-induced apoptosis in view of cell cycle related molecules. In this report, biochemical analysis showed that etoposide-induced apoptosis caused the induction and the nuclear translocation of effector molecules involved in G1 cell cycle checkpoint. However, there was no such translocation in the case of CD95-mediated death. Thus, although both types of apoptosis involved caspase activation, the cell cycle related proteins responded differently. This argues against the idea that p53-induced apoptosis occurs through the induction of CD95/CD95L expression. PMID:12923319

  20. Combined gene expression and proteomic analysis of EGF induced apoptosis in A431 cells suggests multiple pathways trigger apoptosis.

    PubMed

    Alanazi, Ibrahim; Ebrahimie, Esmaeil; Hoffmann, Peter; Adelson, David L

    2013-11-01

    A431 cells, derived from epidermoid carcinoma, overexpress the epidermal growth factor receptor (EGFR) and when treated with a high dose of EGF will undergo apoptosis. We exploited microarray and proteomics techniques and network prediction to study the regulatory mechanisms of EGF-induced apoptosis in A431 cells. We observed significant changes in gene expression in 162 genes, approximately evenly split between pro-apoptotic and anti-apoptotic genes and identified 30 proteins from the proteomic data that had either pro or anti-apoptotic annotation. Our correlation analysis of gene expression and proteome modeled a number of distinct sub-networks that are associated with the onset of apoptosis, allowing us to identify specific pathways and components. These include components of the interferon signalling pathway, and down stream components, including cytokines and suppressors of cytokine signalling. A central component of almost all gene expression sub-networks identified was TP53, which is mutated in A431 cells, and was down regulated. This down regulation of TP53 appeared to be correlated with proteomic sub-networks of cytoskeletal or cell adhesion components that might induce apoptosis by triggering cytochrome C release. Of the only three genes also differentially expressed as proteins, only serpinb1 had a known association with apoptosis. We confirmed that up regulation and cleavage of serpinb1 into L-DNAaseII was correlated with the induction of apoptosis. It is unlikely that a single pathway, but more likely a combination of pathways is needed to trigger EGF induced apoptosis in A431cells.

  1. Evodiamine Induces Apoptosis and Enhances TRAIL-Induced Apoptosis in Human Bladder Cancer Cells through mTOR/S6K1-Mediated Downregulation of Mcl-1

    PubMed Central

    Zhang, Tao; Qu, Shanna; Shi, Qi; He, Dalin; Jin, Xunbo

    2014-01-01

    The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), either alone or in combination with other anti-cancer agents, has been considered as a new strategy for anti-cancer therapy. In this study, we demonstrated that evodiamine, a quinolone alkaloid isolated from the fruit of Evodia fructus, induced apoptosis and enhanced TRAIL-induced apoptosis in human bladder cancer cells. To elucidate the underlying mechanism, we found that evodiamine significantly reduced the protein levels of Mcl-1 in 253J and T24 bladder cancer cells, and overexpression of this molecule attenuated the apoptosis induced by evodiamine alone, or in combination with TRAIL. Further experiments revealed that evodiamine did not affect the mRNA level, proteasomal degradation and protein stability of Mcl-1. On the other hand, evodiamine inhibited the mTOR/S6K1 pathway, which usually regulates protein translation; moreover, knockdown of S6K1 with small interfering RNA (siRNA) effectively reduced Mcl-1 levels, indicating evodiamine downregulates c-FLIP through inhibition of mTOR/S6K1 pathway. Taken together, our results indicate that evodiamine induces apoptosis and enhances TRAIL-induced apoptosis possibly through mTOR/S6K1-mediated downregulation of Mcl-1; furthermore, these findings provide a rationale for the combined application of evodiamine with TRAIL in the treatment of bladder cancer. PMID:24566141

  2. Role of p53 in cdk Inhibitor VMY-1-103-induced Apoptosis in Prostate Cancer

    DTIC Science & Technology

    2013-11-01

    JA, Uren A. Arsenic trioxide inhibits human cancer cell growth and tumor development in mice by blocking Hedgehog /GLI pathway. J Clin Invest. 2011...induced apoptosis in prostate cancer PRINCIPAL INVESTIGATOR: Lymor Ringer...2013 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Role of p53 in cdk inhibitor VMY-1-103-induced apoptosis in prostate cancer 5b. GRANT NUMBER

  3. Propolis suppresses tumor angiogenesis by inducing apoptosis in tube-forming endothelial cells.

    PubMed

    Ohta, Toshiro; Kunimasa, Kazuhiro; Kobayashi, Tomomi; Sakamoto, Miwa; Kaji, Kazuhiko

    2008-09-01

    We have reported that propolis suppresses tumor-induced angiogenesis in vivo and in vitro, but antiangiogenic mechanism of propolis at cellular level remains unclear. In this study, we observed that propolis not only inhibited tube formation but also induced apoptosis of endothelial cells. These results suggest that propolis exerts its antiangiogenic effects at least in part through induction of apoptosis.

  4. Inhibition of phosphate-induced apoptosis in resting zone chondrocytes by thrombin peptide 508.

    PubMed

    Zhong, Ming; Carney, Darrell H; Ryaby, James T; Schwartz, Zvi; Boyan, Barbara D

    2009-01-01

    Growth plate chondrocytes are susceptible to apoptosis. Terminally differentiated chondrocytes are deleted via apoptosis, which primes the growth plate to vascular invasion and subsequent bone formation. Whether less differentiated resting zone chondrocytes are subject to the same mechanism that governs the apoptotic pathway of more differentiated growth zone chondrocytes is not known. In our current study, we demonstrated that inorganic phosphate, a key inducer of growth plate chondrocyte apoptosis, also causes apoptosis in resting zone chondrocytes, via a pathway similar to the one in growth zone chondrocytes. Our results demonstrated that the conditions that cause growth plate chondrocyte apoptosis lie in the external environment, instead of the differences in differentiation state.

  5. Gliotoxin Inhibits Proliferation and Induces Apoptosis in Colorectal Cancer Cells

    PubMed Central

    Chen, Junxiong; Wang, Chenliang; Lan, Wenjian; Huang, Chunying; Lin, Mengmeng; Wang, Zhongyang; Liang, Wanling; Iwamoto, Aikichi; Yang, Xiangling; Liu, Huanliang

    2015-01-01

    The discovery of new bioactive compounds from marine natural sources is very important in pharmacological research. Here we developed a Wnt responsive luciferase reporter assay to screen small molecule inhibitors of cancer associated constitutive Wnt signaling pathway. We identified that gliotoxin (GTX) and some of its analogues, the secondary metabolites from marine fungus Neosartorya pseufofischeri, acted as inhibitors of the Wnt signaling pathway. In addition, we found that GTX downregulated the β-catenin levels in colorectal cancer cells with inactivating mutations of adenomatous polyposis coli (APC) or activating mutations of β-catenin. Furthermore, we demonstrated that GTX induced growth inhibition and apoptosis in multiple colorectal cancer cell lines with mutations of the Wnt signaling pathway. Together, we illustrated a practical approach to identify small-molecule inhibitors of the Wnt signaling pathway and our study indicated that GTX has therapeutic potential for the prevention or treatment of Wnt dependent cancers and other Wnt related diseases. PMID:26445050

  6. Docosahexaenoic Acid Induces Apoptosis in Primary Chronic Lymphocytic Leukemia Cells

    PubMed Central

    Gyan, Emmanuel; Tournilhac, Olivier; Halty, Christelle; Veyrat-Masson, Richard; Akil, Saïda; Berger, Marc; Hérault, Olivier; Callanan, Mary; Bay, Jacques-Olivier

    2015-01-01

    Chronic lymphocytic leukemia is an indolent disorder with an increased infectious risk remaining one of the main causes of death. Development of therapies with higher safety profile is thus a challenging issue. Docosahexaenoic acid (DHA, 22:6) is an omega-3 fatty acid, a natural compound of normal cells, and has been shown to display antitumor potency in cancer. We evaluated the potential in vitro effect of DHA in primary CLL cells. DHA induces high level of in vitro apoptosis compared to oleic acid in a dose-dependent and time-dependent manner. Estimation of IC50 was only of 4.813 µM, which appears lower than those reported in solid cancers. DHA is highly active on CLL cells in vitro. This observation provides a rationale for further studies aiming to understand its mechanisms of action and its potent in vivo activity. PMID:26734128

  7. Ultrastructural lesions induced by neptunium-237: apoptosis or necrosis?

    PubMed

    Pusset, D; Fromm, M; Poncy, J L; Kantelip, B; Galle, P; Chambaudet, A; Baud, M; Boulahdour, H

    2002-07-01

    In this study, we are concerned with the 237 isotope of neptunium (237Np), which is a by-product of uranium in nuclear reactors. To study ultrastructural lesions induced by this element, a group of rats were injected with a solution of 237Np-nitrate once a day for 14 weeks. Lesions observed in liver and kidney are described using electron microscopy. Ultrastructural alterations of cellular membranes and intracellular organelles demonstrated the existence of neptunium toxicity. This toxicity was characterized by various lesions, such as cytoplasmic clarification, disappearance of mitochondrial cristae, swollen mitochondria, abnormal condensation of nuclear chromatin, and nuclear fragmentations. This study demonstrated the probable induction of apoptosis by neptunium both in liver and kidneys.

  8. Promises of apoptosis-inducing peptides in cancer therapeutics.

    PubMed

    Barras, David; Widmann, Christian

    2011-08-01

    Until recently, most research efforts aimed at developing anti-cancer tools were focusing on small molecules. Alternative compounds are now being increasingly assessed for their potential anti-cancer properties, including peptides and their derivatives. One earlier limitation to the use of peptides was their limited capacity to cross membranes but this limitation was alleviated with the characterization of cell-permeable sequences. Additionally, means are designed to target peptides to their malignant targets. Most anti-cancer peptidic compounds induce apoptosis of tumor cells by modulating the activity of Bcl-2 family members that control the release of death factors from the mitochondria or by inhibiting negative regulators of caspases, the proteases that mediate the apoptotic response in cells. Some of these peptides have been shown to inhibit the growth of tumors in mouse models. Hopefully, pro-apoptotic anti-tumor peptides will soon be tested for their efficacy in patients with cancers.

  9. Sensitive apoptosis induced by microcystins in the crucian carp (Carassius auratus) lymphocytes in vitro.

    PubMed

    Zhang, Jianying; Zhang, Hangjun; Chen, Yingxu

    2006-08-01

    Microcystins including leucine-arginine l-amino acid (MCLR) and arginine-arginine l-amino acid (MCRR) can inhibit several serine/threonine protein phosphatases. In this study, we focused on the efficient biomarker for analyzing toxic cyanobacteria blooms using in vitro apoptosis bioassay. We explored the existence of sensitive apoptosis induced by MCLR and MCRR on isolated lymphocytes of the crucian carp (Carassius auratus) at a low exposure level. Apoptosis was detected in vitro and was clearly distinguished by condensation of nuclear chromatin and formation of apoptotic bodies, after 2 h exposure at 1, 5, 10 nM MCLR and MCRR, respectively. Agarose gel electrophoresis further revealed DNA fragmentation (DNA ladder) caused by apoptosis. We found that MCLR and MCRR can induce lymphocyte apoptosis in a dose- and time-dependent manner with flow cytometry analysis. Our study provides the first evidence that microcystins can induce fish lymphocytes apoptosis and may impair fish immune function.

  10. Simple chemicals can induce maturation and apoptosis of dendritic cells

    PubMed Central

    Manome, H; Aiba, S; Tagami, H

    1999-01-01

    As is well known in the case of Langerhans cells, dendritic cells (DCs) play a crucial role in the initiation of immunity to simple chemicals such as noted in the contact hypersensitivity. Because DCs are scattered in non‐lymphoid organs as immature cells, they must be activated to initiate primary antigen‐specific immune reactions. Therefore, we hypothesized that some simple chemicals must affect the function of DCs. In this paper, we first demonstrated that human monocyte‐derived DCs responded to such simple chemicals as 2,4‐dinitrochlorobenzene (DNCB), 2,4,6‐trinitrochlorobenzene (TNCB), 2,4‐dinitrofluorobenzene (DNFB), NiCl2, MnCl2, CoCl2, SnCl2, and CdSO4 by augmenting their expression of CD86 or human leucocyte antigen‐DR (HLA‐DR), down‐regulating c‐Fms expression or increasing their production of tumour necrosis factor‐α (TNF‐α). In addition, the DCs stimulated with the chemicals demonstrated increased allogeneic T‐cell stimulatory function. Next, we found that, among these chemicals, only NiCl2 and CoCl2 induced apoptosis in them. Finally, we examined the effects of these chemicals on CD86 expression by three different macrophage subsets and DCs induced from the cultures of human peripheral blood monocytes in the presence of macrophage colony‐stimulating factor (M‐CSF), M‐CSF + interleukin‐4 (IL‐4), granulocyte–macrophage colony‐stimulating factor (GM‐CSF), and GM‐CSF + IL‐4, respectively. Among them, only DCs dramatically augmented their expression of CD86. These observations have revealed unique characteristics of DCs, which convert chemical stimuli to augmentation of their antigen presenting function, although their responses to different chemicals were not necessarily uniform in the phenotypic changes, cytokine production or in the induction of apoptosis. PMID:10594678

  11. RGD-FasL Induces Apoptosis in Hepatocellular Carcinoma

    PubMed Central

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

    2009-01-01

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

  12. Somatostatin protects photoreceptor cells against high glucose–induced apoptosis

    PubMed Central

    Mazzeo, Aurora; Cazzoni, Daniele; Beltramo, Elena; Hernández, Cristina; Porta, Massimo; Simó, Rafael; Valverde, Ángela M.

    2016-01-01

    Purpose Many cellular and molecular studies in experimental animals and early retinal function tests in patients with diabetic retinopathy (DR) have shown that retinal neurodegeneration is an early event in the pathogenesis of the disease. Somatostatin (SST) is one of the most important neuroprotective factors synthesized by the retina: SST levels are decreased in parallel to retinal neurodegeneration in early stages of DR. In this study, we characterized the induction of apoptosis (programmed cell death) in a 661W photoreceptor-like cell line cultured under high glucose (HG) conditions and the effect of SST. Methods A 661W photoreceptor-like cell line and retinal explants from 10-week-old male C57BL/6 mice were cultured under HG conditions and treated with SST. Results Hyperglycemia significantly reduced the cellular viability by increasing the percentage of apoptotic cells, and this effect was ameliorated by SST (p˂0.05). Activation of caspase-8 by hyperglycemia was found in the 661W cells and retinal explants and decreased in the presence of SST (p˂0.05). Moreover, we detected activation of calpain-2 associated with hyperglycemia-induced cell death, as well as increased protein tyrosine phosphatase 1B (PTP1B) protein levels; both had a pattern of cleavage that was absent in the presence of SST (p˂0.05). Treatment of the 661W cells and retinal explants with SST for 24 h increased the phosphorylation of type 1 insulin-like growth factor receptor (IGF-IR; tyrosine 1165/1166) and protein kinase B (Akt; serine 473), suggesting this survival signaling is activated in the neuroretina by SST (p˂0.05). Conclusions This study has provided new mechanistic insights first into the involvement of calpain-2 and PTP1B in the loss of cell survival and increased caspase-8-dependent apoptosis induced by hyperglycemia in photoreceptor cells and second, on the protective effect of SST against apoptosis by the enhancement of IGF-IR-mediated Akt phosphorylation. PMID:28050125

  13. Down-regulation of survivin in nitric oxide-induced cell growth inhibition and apoptosis of the human lung carcinoma cells.

    PubMed

    Chao, Jui-I; Kuo, Pao-Chen; Hsu, Tzu-Sheng

    2004-05-07

    Survivin is expressed in most tumor cells and has been associated with both anti-apoptosis and mitotic progression. However, the mechanism of regulation of the survivin expression remains unclear. In this study we investigated the expression and regulation of survivin in the nitric oxide (NO)-exposed human lung carcinoma cells. The lung carcinoma cell lines CL3, H1299, and A549 but not normal lung fibroblast expressed high levels of survivin proteins. NO donors S-nitroso-N-acetyl-penicillamine (SNAP) and sodium nitroprusside (SNP) decreased the survivin expression. SNAP (0.4 mm, 24h)and SNP (1 mm, 24 h) significantly induced cytotoxicity and apoptosis in lung carcinoma cells. Furthermore, SNAP inhibited the cell growth and increased the fractions of G(2)/M phase. The levels of cyclin B1 and phospho-cdc2-(Thr-161) proteins were inhibited in the NO-exposed cells. The cdc25 phosphatase inhibitors (Cpd 5 and NSC 663284) and the cdc2 kinase inhibitors (alsterpaullone and purvalanol A) enhanced SNP-induced cytotoxicity and the decrease in survivin expression. However, overexpression of survivin by a pOTB7-survivin vector reduced SNP-induced cell growth inhibition and cytotoxicity. In addition, SNP activated the phosphorylation of p38 mitogen-activated protein (MAP) kinase. The specific p38 MAP kinase inhibitor, SB202190, significantly decreased the cytotoxicity and increased the survivin levels in NO donor-treated and inducible NOS-transfected cells. Conversely, anticancer agents including quercetin, arsenite, and cisplatin but not genistein increased the levels of survivin protein. Our results indicated for the first time that NO inhibited the expression of survivin, which was down-regulated by the p38 MAP kinase pathway.

  14. Regulation of isocyanate-induced apoptosis, oxidative stress, and inflammation in cultured human neutrophils: isocyanate-induced neutrophils apoptosis.

    PubMed

    Mishra, P K; Khan, S; Bhargava, A; Panwar, H; Banerjee, S; Jain, S K; Maudar, K K

    2010-06-01

    Implications of environmental toxins on the regulation of neutrophil function are being significantly appraised. Such effects can be varied and markedly different depending on the type and extent of chemical exposure, which results in direct damage to the immune system. Isocyanates with functional group (-NCO), are considered as highly reactive molecules with diverse industrial applications. However, patho-physiological implications resulting from their occupational and accidental exposures have not been well delineated. The present study was carried out to assess the immunotoxic response of isocyanates and their mode of action at a molecular level on cultured human neutrophils isolated from healthy human volunteers. Studies were conducted to evaluate both dose- and time-dependent (n = 3) response using N-succinimidyl N-methylcarbamate, a chemical entity that mimics the effects of methyl isocyanate in vitro. Measure of apoptosis through annexin-V-FITC/PI assay, active caspase-3, apoptotic DNA ladder assay and mitochondrial depolarization; induction of oxidative stress by CM-H(2)DCFDA and formation of 8'-hydroxy-2'-deoxyguanosine; and levels of antioxidant defense system enzyme glutathione reductase, multiplex cytometric bead array analysis to quantify the secreted cytokine levels (interleukin-8, interleukin-1beta, interleukin-6, interleukin-10, interferon-gamma, tumor necrosis factor, and interleukin-12p70) parameters were evaluated. Our results demonstrate that isocyanates induce neutrophil apoptosis via activation of mitochondrial-mediated pathway along with reactive oxygen species production; depletion in antioxidant defense states; and elevated pro-inflammatory cytokine response.

  15. Caspase-12 is involved in stretch-induced apoptosis mediated endoplasmic reticulum stress.

    PubMed

    Zhang, Qiang; Liu, Jianing; Chen, Shulan; Liu, Jing; Liu, Lijuan; Liu, Guirong; Wang, Fang; Jiang, Wenxin; Zhang, Caixia; Wang, Shuangyu; Yuan, Xiao

    2016-04-01

    It is well recognized that mandibular growth, which is caused by a variety of functional appliances, is considered to be the result of both neuromuscular and skeletal adaptations. Accumulating evidence has demonstrated that apoptosis plays an important role in the adaptation of skeletal muscle function. However, the underlying mechanism of apoptosis that is induced by stretch continues to be incompletely understood. Endoplasmic reticulum stress (ERS), a newly defined signaling pathway, initiates apoptosis. This study seeks to determine if caspase-12 is involved in stretch-induced apoptosis mediated endoplasmic reticulum stress in myoblast and its underlying mechanism. Apoptosis was assessed by Hochest staining, DAPI staining and annexin V binding and PI staining. ER chaperones, such as GRP78, CHOP and caspase-12, were determined by reverse transcription polymerase chain reaction (RT-PCR) and Western blot. Furthermore, caspase-12 inhibitor was used to value the mechanism of the caspase-12 pathway. Apoptosis of myoblast, which is subjected to cyclic stretch, was observed in a time-dependent manner. We found that GRP78 mRNA and protein were significantly increased and CHOP and caspase-12 were activated in myoblast that was exposed to cyclic stretch. Caspase-12 inhibition reduced stretch-induced apoptosis, and caspase-12 activated caspase-3 to induce apoptosis. We concluded that caspase-12 played an important role in stretch-induced apoptosis that is associated by endoplasmic reticulum stress by activating caspase-3.

  16. PUMA mediates ER stress-induced apoptosis in portal hypertensive gastropathy.

    PubMed

    Tan, S; Wei, X; Song, M; Tao, J; Yang, Y; Khatoon, S; Liu, H; Jiang, J; Wu, B

    2014-03-13

    Mucosal apoptosis has been demonstrated to be an essential pathological feature in portal hypertensive gastropathy (PHG). p53-upregulated modulator of apoptosis (PUMA) was identified as a BH3-only Bcl-2 family protein that has an essential role in apoptosis induced by a variety of stimuli, including endoplasmic reticulum (ER) stress. However, whether PUMA is involved in mucosal apoptosis in PHG remains unclear, and whether PUMA induces PHG by mediating ER stress remains unknown. The aim of the study is to investigate whether PUMA is involved in PHG by mediating ER stress apoptotic signaling. To identify whether PUMA is involved in PHG by mediating ER stress, gastric mucosal injury and apoptosis were studied in both PHG patients and PHG animal models using PUMA knockout (PUMA-KO) and PUMA wild-type (PUMA-WT) mice. The induction of PUMA expression and ER stress signaling were investigated, and the mechanisms of PUMA-mediated apoptosis were analyzed. GES-1 and SGC7901 cell lines were used to further identify whether PUMA-mediated apoptosis was induced by ER stress in vitro. Epithelial apoptosis and PUMA were markedly induced in the gastric mucosa of PHG patients and mouse PHG models. ER stress had a potent role in the induction of PUMA and apoptosis in PHG models, and the apoptosis was obviously attenuated in PUMA-KO mice. Although the targeted deletion of PUMA did not affect ER stress, mitochondrial apoptotic signaling was downregulated in mice. Meanwhile, PUMA knockdown significantly ameliorated ER stress-induced mitochondria-dependent apoptosis in vitro. These results indicate that PUMA mediates ER stress-induced mucosal epithelial apoptosis through the mitochondrial apoptotic pathway in PHG, and that PUMA is a potentially therapeutic target for PHG.

  17. Modulation of iridovirus-induced apoptosis by endocytosis, early expression, JNK, and apical caspase

    SciTech Connect

    Chitnis, Nilesh S.; D'Costa, Susan M.; Paul, Eric R.; Bilimoria, Shaen L.

    2008-01-20

    Chilo iridescent virus (CIV) is the type species for the family Iridoviridae, which are large, isometric, cytoplasmic dsDNA viruses. We examined the mechanism of apoptosis induction by CIV. High CIV doses (CIV{sub XS}; 400 {mu}g/ml), UV-irradiated virus (CIV{sub UV}; 10 {mu}g/ml) and CVPE (CIV protein extract; 10 {mu}g/ml) induced apoptosis in 60% of treated Choristoneura fumiferana (IPRI-CF-124T) cells. Normal doses of infectious CIV (10 {mu}g/ml) induced apoptosis in only 10% of C. fumiferana (CF) cells. Apoptosis was inhibited by Z-IETD-FMK, an apical caspase inhibitor, indicating that CIV-induced apoptosis requires caspase activity. The putative caspase in CF cells was designated Cf-caspase-i. CIV{sub UV} or CVPE enhanced Cf-caspase-i activity by 80% at 24 h relative to mock-treated cells. Since the MAP kinase pathway induces or inhibits apoptosis depending on the context, we used JNK inhibitor SP600125 and demonstrated drastic suppression of CVPE-induced apoptosis. Thus, the JNK signaling pathway is significant for apoptosis in this system. Virus interaction with the cell surface was not sufficient for apoptosis since CIV{sub UV} particles bound to polysterene beads failed to induce apoptosis. Endocytosis inhibitors (bafilomycin or ammonium chloride) negated apoptosis induction by CIV{sub UV}, CIV{sub XS} or CVPE indicating that entry through this mode is required. Given the weak apoptotic response to infectious CIV, we postulated that viral gene expression inhibited apoptosis. CIV infection of cells pretreated with cycloheximide induced apoptosis in 69% of the cells compared to 10% in normal infections. Furthermore, blocking viral DNA replication with aphidicolin or phosphonoacetic acid suppressed apoptosis and Cf-caspase-i activity, indicating that early viral expression is necessary for inhibition of apoptosis, and de novo synthesis of viral proteins is not required for induction. We show for the first time that, in a member of the family Iridoviridae

  18. Ouabain-induced perturbations in intracellular ionic homeostasis regulate death receptor-mediated apoptosis.

    PubMed

    Panayiotidis, Mihalis I; Franco, Rodrigo; Bortner, Carl D; Cidlowski, John A

    2010-07-01

    Apoptosis is defined by specific morphological and biochemical characteristics including cell shrinkage (termed apoptotic volume decrease), a process that results from the regulation of ion channels and plasma membrane transporter activity. The Na(+)-K(+)-ATPase is the predominant pump that controls cell volume and plasma membrane potential in cells and alterations in its function have been suggested to be associated with apoptosis. We report here that the Na(+)-K(+)-ATPase inhibitor ouabain, potentiates apoptosis in the human lymphoma Jurkat cells exposed to Fas ligand (FasL) or tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) but not other apoptotic agents such as H(2)O(2), thapsigargin or UV-C implicating a role for the Na(+)-K(+)-ATPase in death receptor-induced apoptosis. Interestingly, ouabain also potentiated perturbations in cell Ca(2+) homeostasis only in conjunction with the apoptotic inducer FasL but not TRAIL. Ouabain did not affect alterations in the intracellular Ca(2+) levels in response to H(2)O(2), thapsigargin or UV-C. FasL-induced alterations in Ca(2+) were not abolished in Ca(2+)-free medium but incubation of cells with BAPTA-AM inhibited both Ca(2+) perturbations and the ouabain-induced potentiation of FasL-induced apoptosis. Our data suggest that the impairment of the Na(+)-K(+)-ATPase activity during apoptosis is linked to perturbations in cell Ca(2+) homeostasis that modulate apoptosis induced by the activation of Fas by FasL.

  19. Mitochondrial DNA damage induces apoptosis in senescent cells

    PubMed Central

    Laberge, R-M; Adler, D; DeMaria, M; Mechtouf, N; Teachenor, R; Cardin, G B; Desprez, P-Y; Campisi, J; Rodier, F

    2013-01-01

    Senescence is a cellular response to damage and stress. The senescence response prevents cancer by suppressing the proliferation of cells with a compromised genome and contributes to optimal wound healing in normal tissues. Persistent senescent cells are also thought to drive aging and age-associated pathologies through their secretion of inflammatory factors that modify the tissue microenvironment and alter the function of nearby normal or transformed cells. Understanding how senescent cells alter the microenvironment would be aided by the ability to induce or eliminate senescent cells at will in vivo. Here, we combine the use of the synthetic nucleoside analog ganciclovir (GCV) with herpes simplex virus thymidine kinase (HSVtk) activity to create or eliminate senescent human cells. We show that low concentrations of GCV induce senescence through the accumulation of nuclear DNA damage while higher concentrations of GCV, similar to those used in vivo, kill non-dividing senescent cells via mitochondrial DNA (mtDNA) damage and caspase-dependent apoptosis. Using this system, we effectively eliminated xenografted normal human senescent fibroblasts or induced senescence in human breast cancer cells in vivo. Thus, cellular senescence and mtDNA damage are outcomes of synthetic nucleoside analog treatment, indicating that the GCV–HSVtk combination can be used effectively to promote the targeted formation or eradication of senescent cells. PMID:23868060

  20. Mitochondrial DNA damage induces apoptosis in senescent cells.

    PubMed

    Laberge, R-M; Adler, D; DeMaria, M; Mechtouf, N; Teachenor, R; Cardin, G B; Desprez, P-Y; Campisi, J; Rodier, F

    2013-07-18

    Senescence is a cellular response to damage and stress. The senescence response prevents cancer by suppressing the proliferation of cells with a compromised genome and contributes to optimal wound healing in normal tissues. Persistent senescent cells are also thought to drive aging and age-associated pathologies through their secretion of inflammatory factors that modify the tissue microenvironment and alter the function of nearby normal or transformed cells. Understanding how senescent cells alter the microenvironment would be aided by the ability to induce or eliminate senescent cells at will in vivo. Here, we combine the use of the synthetic nucleoside analog ganciclovir (GCV) with herpes simplex virus thymidine kinase (HSVtk) activity to create or eliminate senescent human cells. We show that low concentrations of GCV induce senescence through the accumulation of nuclear DNA damage while higher concentrations of GCV, similar to those used in vivo, kill non-dividing senescent cells via mitochondrial DNA (mtDNA) damage and caspase-dependent apoptosis. Using this system, we effectively eliminated xenografted normal human senescent fibroblasts or induced senescence in human breast cancer cells in vivo. Thus, cellular senescence and mtDNA damage are outcomes of synthetic nucleoside analog treatment, indicating that the GCV-HSVtk combination can be used effectively to promote the targeted formation or eradication of senescent cells.

  1. RIP-1/c-FLIPL Induce Hepatic Cancer Cell Apoptosis Through Regulating Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand (TRAIL)

    PubMed Central

    Sun, Jichun; Yu, Xiao; Wang, Changfa; Yu, Can; Li, Zhiqiang; Nie, Wanpin; Xu, Xundi; Miao, Xiongying; Jin, Xiaoxin

    2017-01-01

    Background Almost all hepatic cancer cells have resistance to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis. c-FLIPL and RIP-1 are apoptotic negative regulatory factors. This study investigated the role of c-FLIPL and RIP-1 in hepatic cancer cell resistance to TRAIL-induced apoptosis. Material/Methods HepG2 cells were treated by TRAIL, RIP-1 siRNA, and/or BY11-7082. Cell viability was detected by MTT assay. Cell apoptosis was tested by flow cytometry. DISC component proteins, RIP-1, and p-p65 were measured by Western blot. Caspase-8 and caspase-3 were determined by spectrophotometry. Results Single TRAIL treatment showed no significant impact on cell proliferation and apoptosis. HepG2 cells expressed high levels of RIP1 and c-FLIPL, while a high concentration of TRAIL upregulated RIP-1 and c-FLIPL expression but not DR4 and DR5. Single TRAIL treatment did not obviously activate caspase-8 and caspase-3. RIP-1 or c-FLIPL siRNA markedly induced cell apoptosis and enhanced caspase-8 and caspase-3 activities. Combined transfection obviously increased apoptotic cells. TRAIL markedly upregulated RIP-1 expression and enhanced p-p65 protein. Downregulating RIP-1 and/or BAY11-7082 significantly reduced NF-κB transcriptional activity, blocked cells in G0/G1 phase, weakened proliferation, elevated caspase-8 and caspase-3 activities, and promoted cell apoptosis. Conclusions TRAIL can enhance RIP1 and c-FLIPL expression in HepG2 cells. High expression of RIP1 and c-FLIPL is an important reason for TRAIL resistance. Downregulation of RIP1 and c-FLIPL can relieve caspase-8 suppression, activate caspase-3, and promote cell apoptosis. TRAIL mediates apoptosis resistance through upregulating RIP-1 expression, enhancing NF-κB transcriptional activity, and weakening caspase activity. PMID:28270653

  2. Dihydroartemisinin induces apoptosis preferentially via a Bim-mediated intrinsic pathway in hepatocarcinoma cells.

    PubMed

    Qin, Guiqi; Zhao, ChuBiao; Zhang, Lili; Liu, Hongyu; Quan, Yingyao; Chai, Liuying; Wu, Shengnan; Wang, Xiaoping; Chen, Tongsheng

    2015-08-01

    This report is designed to dissect the detail molecular mechanism by which dihydroartemisinin (DHA), a derivative of artemisinin, induces apoptosis in human hepatocellular carcinoma (HCC) cells. DHA induced a loss of the mitochondrial transmemberane potential (ΔΨm), release of cytochrome c, activation of caspases, and externalization of phosphatidylserine indicative of apoptosis induction. Compared with the modest inhibitory effects of silencing Bax, silencing Bak largely prevented DHA-induced ΔΨm collapse and apoptosis though DHA induced a commensurable activation of Bax and Bak, demonstrating a key role of the Bak-mediated intrinsic apoptosis pathway. DHA did not induce Bid cleavage and translocation from cytoplasm to mitochondria and had little effects on the expressions of Puma and Noxa, but did increase Bim and Bak expressions and decrease Mcl-1 expression. Furthermore, the cytotoxicity of DHA was remarkably reduced by silencing Bim, and modestly but significantly reduced by silencing Puma or Noxa. Silencing Bim or Noxa preferentially reduced DHA-induced Bak activation, while silencing Puma preferentially reduced DHA-induced Bax activation, demonstrating that Bim and to a lesser extent Noxa act as upstream mediators to trigger the Bak-mediated intrinsic apoptosis pathway. In addition, silencing Mcl-1 enhanced DHA-induced Bak activation and apoptosis. Taken together, our data demonstrate a crucial role of Bim in preferentially regulating the Bak/Mcl-1 rheostat to mediate DHA-induced apoptosis in HCC cells.

  3. HMGB1 mediates hyperglycaemia-induced cardiomyocyte apoptosis via ERK/Ets-1 signalling pathway.

    PubMed

    Wang, Wen-Ke; Lu, Qing-Hua; Zhang, Jia-Ning; Wang, Ben; Liu, Xiang-Juan; An, Feng-Shuang; Qin, Wei-Dong; Chen, Xue-Ying; Dong, Wen-Qian; Zhang, Cheng; Zhang, Yun; Zhang, Ming-Xiang

    2014-11-01

    Apoptosis is a key event involved in diabetic cardiomyopathy. The expression of high mobility group box 1 protein (HMGB1) is up-regulated in diabetic mice. However, the molecular mechanism of high glucose (HG)-induced cardiomyocyte apoptosis remains obscure. We aimed to determine the role of HMGB1 in HG-induced apoptosis of cardiomyocytes. Treating neonatal primary cardiomyocytes with HG increased cell apoptosis, which was accompanied by elevated levels of HMGB1. Inhibition of HMGB1 by short-hairpin RNA significantly decreased HG-induced cell apoptosis by reducing caspase-3 activation and ratio of Bcl2-associated X protein to B-cell lymphoma/leukemia-2 (bax/bcl-2). Furthermore, HG activated E26 transformation-specific sequence-1 (Ets-1), and HMGB1 inhibition attenuated HG-induced activation of Ets-1 via extracellular signal-regulated kinase 1/2 (ERK1/2) signalling. In addition, inhibition of Ets-1 significantly decreased HG-induced cardiomyocyte apoptosis. Similar results were observed in streptozotocin-treated diabetic mice. Inhibition of HMGB1 by short-hairpin RNA markedly decreased myocardial cell apoptosis and activation of ERK and Ets-1 in diabetic mice. In conclusion, inhibition of HMGB1 may protect against hyperglycaemia-induced cardiomyocyte apoptosis by down-regulating ERK-dependent activation of Ets-1.

  4. ASPP2 Plays a Dual Role in gp120-Induced Autophagy and Apoptosis of Neuroblastoma Cells.

    PubMed

    Liu, Zhiying; Qiao, Luxin; Zhang, Yulin; Zang, Yunjing; Shi, Ying; Liu, Kai; Zhang, Xin; Lu, Xiaofan; Yuan, Lin; Su, Bin; Zhang, Tong; Wu, Hao; Chen, Dexi

    2017-01-01

    HIV invasion of the central nervous system (CNS) in the majority of patients infected with HIV-1, leads to dysfunction and injury within the CNS, showing a variety of neurological symptoms which was broadly termed HIV-associated neurocognitive disorder (HAND). But the molecular mechanisms are not completely understood. It has been suggested that apoptosis and autophagic dysfunction in neurons may play an important role in the development of HAND. Previous studies have indicated that p53 may be involved in the onset of neurological disorder in AIDS. Apoptosis-stimulating protein of p53-2 (ASPP2), a p53-binding protein with specific function of inducing p53, has been reported to modulate autophagy. In the present study, we observed that gp120 induces autophagy and apoptosis in SH-SY5Y neuroblastoma cells. Adenovirus-mediated overexpression of ASPP2 significantly inhibited autophagy and apoptosis induced by low dose of gp120 protein (50 ng/mL), but induced autophagy and apoptosis when treated by high dose of gp120 protein (200 ng/mL). Further, ASPP2 knockdown attenuated autophagy and apoptosis induced by gp120. Conclusion: ASPP2 had different effects on the autophagy and apoptosis of neurons induced by different concentration of gp120 protein. It may be a potential therapeutic agent for HAND through modulating autophagy and apoptosis in CNS.

  5. ASPP2 Plays a Dual Role in gp120-Induced Autophagy and Apoptosis of Neuroblastoma Cells

    PubMed Central

    Liu, Zhiying; Qiao, Luxin; Zhang, Yulin; Zang, Yunjing; Shi, Ying; Liu, Kai; Zhang, Xin; Lu, Xiaofan; Yuan, Lin; Su, Bin; Zhang, Tong; Wu, Hao; Chen, Dexi

    2017-01-01

    HIV invasion of the central nervous system (CNS) in the majority of patients infected with HIV-1, leads to dysfunction and injury within the CNS, showing a variety of neurological symptoms which was broadly termed HIV-associated neurocognitive disorder (HAND). But the molecular mechanisms are not completely understood. It has been suggested that apoptosis and autophagic dysfunction in neurons may play an important role in the development of HAND. Previous studies have indicated that p53 may be involved in the onset of neurological disorder in AIDS. Apoptosis-stimulating protein of p53-2 (ASPP2), a p53-binding protein with specific function of inducing p53, has been reported to modulate autophagy. In the present study, we observed that gp120 induces autophagy and apoptosis in SH-SY5Y neuroblastoma cells. Adenovirus-mediated overexpression of ASPP2 significantly inhibited autophagy and apoptosis induced by low dose of gp120 protein (50 ng/mL), but induced autophagy and apoptosis when treated by high dose of gp120 protein (200 ng/mL). Further, ASPP2 knockdown attenuated autophagy and apoptosis induced by gp120. Conclusion: ASPP2 had different effects on the autophagy and apoptosis of neurons induced by different concentration of gp120 protein. It may be a potential therapeutic agent for HAND through modulating autophagy and apoptosis in CNS. PMID:28392757

  6. Calmodulin inhibition contributes to sensitize TRAIL-induced apoptosis in human lung cancer H1299 cells.

    PubMed

    Hwang, Mi-kyung; Min, Yong Ki; Kim, Seong Hwan

    2009-12-01

    Tumor necrosis factor related apoptosis-inducing ligand (TRAIL) preferentially triggers apoptosis in tumor cells versus normal cells. However, TRAIL alone is not effective in treating TRAIL-resistant tumors. We evaluated the effect of 180 enzyme inhibitors on TRAIL-induced apoptosis in human lung cancer H1299 cells, and found fluphenazine-N-2-chloroethane (a calmodulin (CaM) antagonist) sensitized TRAIL-induced apoptosis. Interestingly, in the presence of TRAIL, it increased caspase-8 binding to the Fas-associated death domain (FADD), but decreased binding of FADD-like interleukin-1beta-converting enzyme inhibitory proteins (FLIPs). Additionally, its combination with TRAIL inhibited Akt phosphorylation. These results were consistently observed in cells treated with CaM siRNA. We suggested the blockade of CaM could sensitize lung cancer cells to TRAIL-induced apoptosis in at least 2 ways: (i) it can activate death-inducing signaling complex mediated apoptosis by inhibiting TRAIL-induced binding of FLIP and TRAIL-enhanced binding of caspase-8 to FADD; (ii) it can inhibit Akt phosphorylation, consequently leading to decreased expression of anti-apoptotic molecules such as FLIP and members of the inhibitor of apoptosis protein family. This study suggests the combination of CaM antagonists with TRAIL may have the therapeutic potential to overcome the resistance of lung cancers to apoptosis.

  7. induces PUMA activation: a new mechanism for Aβ-mediated neuronal apoptosis.

    PubMed

    Feng, Jie; Meng, Chengbo; Xing, Da

    2015-02-01

    p53 upregulated modulator of apoptosis (PUMA) is a promising tumor therapy target because it elicits apoptosis and profound sensitivity to radiation and chemotherapy. However, inhibition of PUMA may be beneficial for curbing excessive apoptosis associated with neurodegenerative disorders. Alzheimer's disease (AD) is a representative neurodegenerative disease in which amyloid-β (Aβ) deposition causes neurotoxicity. The regulation of PUMA during Aβ-induced neuronal apoptosis remains poorly understood. Here, we reported that PUMA expression was significantly increased in the hippocampus of transgenic mice models of AD and hippocampal neurons in response to Aβ. PUMA knockdown protected the neurons against Aβ-induced apoptosis. Furthermore, besides p53, PUMA transactivation was also regulated by forkhead box O3a through p53-independent manner following Aβ treatment. Notably, PUMA contributed to neuronal apoptosis through competitive binding of apoptosis repressor with caspase recruitment domain to activate caspase-8 that cleaved Bid into tBid to accelerate Bax mitochondrial translocation, revealing a novel pathway of Bax activation by PUMA to mediate Aβ-induced neuronal apoptosis. Together, we demonstrated that PUMA activation involved in Aβ-induced apoptosis, representing a drug target to antagonize AD progression.

  8. Apoptosis-inducing activity of high molecular weight fractions of tea extracts.

    PubMed

    Hayakawa, S; Kimura, T; Saeki, K; Koyama, Y; Aoyagi, Y; Noro, T; Nakamura, Y; Isemura, M

    2001-02-01

    High molecular weight fractions of green tea, black tea, oolong tea, and pu-erh tea were found to induce apoptosis in human monoblastic leukemia U937 cells by examination of their ability to inhibit cell proliferation and to induce apoptotic body formation and DNA ladder formation. These tea fractions were also shown to induce apoptosis in stomach cancer MKN-45 cells. In addition to known antitumor-promoting activity of tea high molecular weight fractions, their apoptosis-inducing activity may contribute to cancer chemopreventive effects of tea.

  9. Inhibitory Effects of Sodium Arsenite and Acacia Honey on Acetylcholinesterase in Rats

    PubMed Central

    Odunola, Oyeronke A.; Gbadegesin, Michael A.; Sallau, Abdullahi B.; Ndidi, Uche S.; Ibrahim, Mohammed A.

    2015-01-01

    This study was conducted to investigate the effect of sodium arsenite and Acacia honey on acetylcholinesterase (AChE) activity and electrolytes in the brain and serum of Wistar rats. Male Wistar albino rats in four groups of five rats each were treated with distilled water, sodium arsenite (5 mg/kg body weight), Acacia honey (20% v/v), and sodium arsenite and Acacia honey, daily for one week. The sodium arsenite and Acacia honey significantly (P < 0.05) decreased AChE activity in the brain with the combined treatment being more potent. Furthermore, sodium arsenite and Acacia honey significantly (P < 0.05) decreased AChE activity in the serum. Strong correlation was observed between the sodium and calcium ion levels with acetylcholinesterase activity in the brain and serum. The gas chromatography mass spectrometry analysis of Acacia honey revealed the presence of a number of bioactive compounds such as phenolics, sugar derivatives, and fatty acids. These findings suggest that sodium arsenite and/or Acacia honey modulates acetylcholinesterase activities which may be explored in the management of Alzheimer's diseases but this might be counteracted by the hepatotoxicity induced by arsenics. PMID:25821630

  10. Ginger (Zingiber officinale) induces apoptosis in Trichomonas vaginalis in vitro

    PubMed Central

    Arbabi, Mohsen; Delavari, Mahdi; Fakhrieh Kashan, Zohre; Taghizadeh, Mohsen; Hooshyar, Hossein

    2016-01-01

    Background: Trichomoniasis is the most common sexually transmitted protozoan diseases in the worldwide. Metronidazole is the choice drug for trichomoniasis treatment, however, metronidazole resistant Trichomonas vaginalis (T.vaginalis) has been reported. Natural products are the source of most new drugs, and Zingiber officinale (Ginger) is widely used ingredient in the traditional medicine. Objective: The aim of the present study was to determine the effect of different concentrations of the ginger ethanol extract on the growth of T.vaginalis trophozoites in vitro. Materials and Methods: In this experimental study, 970 women who were attend in Kashan health centers were examined for T. vaginalis. Of them, 23 samples were infected with T.vaginalis. Three T. vaginalis isolates were cultured in a TYI-S-33 medium. The effect of ginger ethanol extracts and its toxicity in different concentrations (25, 50, 100, 200, 400, 800 µg/ml) on mouse macrophages were measured in triplicate exam by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. The effect of ginger on apoptosis induction was determined by Flow cytometry. Results: The IC50 of ginger and metronidazole were 93.8 and 0.0326 µg/ml, respectively. 12, 24 and 48 hr after adding different concentrations of extract on mouse macrophages, fatality rates in maximum dose (800 µg/ml) were 0.19, 0.26 and 0.31 respectively. Flow cytometry results showed the apoptosis rate following treatment with different concentrations of the extract after 48 hr were 17, 28.5, 42.1, 58.8, 76.3 and 100% respectively, while in the control group was 2.9%. Conclusion: Ginger ethanol extract induces programmed death in T. vaginalis. It is recommended that due to the known teratogenic effect of metronidazole, ginger can be considered as an alternative drug for metronidazole. PMID:27981254

  11. Inhibition of protein geranylgeranylation induces apoptosis in synovial fibroblasts.

    PubMed

    Connor, Alison M; Berger, Stuart; Narendran, Aru; Keystone, Edward C

    2006-01-01

    Statins, competitive inhibitors of hydroxymethylglutaryl-CoA reductase, have recently been shown to have a therapeutic effect in rheumatoid arthritis (RA). In RA, synovial fibroblasts in the synovial lining, are believed to be particularly important in the pathogenesis of disease because they recruit leukocytes into the synovium and secrete angiogenesis-promoting molecules and proteases that degrade extracellular matrix. In this study, we show a marked reduction in RA synovial fibroblast survival through the induction of apoptosis when the cells were cultured with statins. Simvastatin was more effective in RA synovial fibroblasts than atorvastatin, and both statins were more potent on tumor necrosis factor-alpha-induced cells. In contrast, in osteoarthritis synovial fibroblasts, neither the statin nor the activation state of the cell contributed to the efficacy of apoptosis induction. Viability of statin-treated cells could be rescued by geranylgeraniol but not by farnesol, suggesting a requirement for a geranylgeranylated protein for synovial fibroblast survival. Phase partitioning experiments confirmed that in the presence of statin, geranylgeranylated proteins are redistributed to the cytoplasm. siRNA experiments demonstrated a role for Rac1 in synovial fibroblast survival. Western blotting showed that the activated phosphorylated form of Akt, a protein previously implicated in RA synovial fibroblast survival, was decreased by about 75%. The results presented in this study lend further support to the importance of elevated pAkt levels to RA synovial fibroblast survival and suggest that statins might have a beneficial role in reducing the aberrant pAkt levels in patients with RA. The results may also partly explain the therapeutic effect of atorvastatin in patients with RA.

  12. Lipopolysaccharide Induces Human Pulmonary Micro-Vascular Endothelial Apoptosis via the YAP Signaling Pathway

    PubMed Central

    Yi, Lei; Huang, Xiaoqin; Guo, Feng; Zhou, Zengding; Chang, Mengling; Tang, Jiajun; Huan, Jingning

    2016-01-01

    Gram-negative bacterial lipopolysaccharide (LPS) induces a pathologic increase in lung vascular leakage under septic conditions. LPS-induced human pulmonary micro-vascular endothelial cell (HPMEC) apoptosis launches and aggravates micro-vascular hyper-permeability and acute lung injury (ALI). Previous studies show that the activation of intrinsic apoptotic pathway is vital for LPS-induced EC apoptosis. Yes-associated protein (YAP) has been reported to positively regulate intrinsic apoptotic pathway in tumor cells apoptosis. However, the potential role of YAP protein in LPS-induced HPMEC apoptosis has not been determined. In this study, we found that LPS-induced activation and nuclear accumulation of YAP accelerated HPMECs apoptosis. LPS-induced YAP translocation from cytoplasm to nucleus by the increased phosphorylation on Y357 resulted in the interaction between YAP and transcription factor P73. Furthermore, inhibition of YAP by small interfering RNA (siRNA) not only suppressed the LPS-induced HPMEC apoptosis but also regulated P73-mediated up-regulation of BAX and down-regulation of BCL-2. Taken together, our results demonstrated that activation of the YAP/P73/(BAX and BCL-2)/caspase-3 signaling pathway played a critical role in LPS-induced HPMEC apoptosis. Inhibition of the YAP might be a potential therapeutic strategy for lung injury under sepsis. PMID:27807512

  13. Lipopolysaccharide Stimulates Butyric Acid-Induced Apoptosis in Human Peripheral Blood Mononuclear Cells

    PubMed Central

    Kurita-Ochiai, Tomoko; Fukushima, Kazuo; Ochiai, Kuniyasu

    1999-01-01

    We previously reported that butyric acid, an extracellular metabolite from periodontopathic bacteria, induced apoptosis in murine thymocytes, splenic T cells, and human Jurkat T cells. In this study, we examined the ability of butyric acid to induce apoptosis in peripheral blood mononuclear cells (PBMC) and the effect of bacterial lipopolysaccharide (LPS) on this apoptosis. Butyric acid significantly inhibited the anti-CD3 monoclonal antibody- and concanavalin A-induced proliferative responses in a dose-dependent fashion. This inhibition of PBMC growth by butyric acid depended on apoptosis in vitro. It was characterized by internucleosomal DNA digestion and revealed by gel electrophoresis followed by a colorimetric DNA fragmentation assay to occur in a concentration-dependent fashion. Butyric acid-induced PBMC apoptosis was accompanied by caspase-3 protease activity but not by caspase-1 protease activity. LPS potentiated butyric acid-induced PBMC apoptosis in a dose-dependent manner. Flow-cytometric analysis revealed that LPS increased the proportion of sub-G1 cells and the number of late-stage apoptotic cells induced by butyric acid. Annexin V binding experiments with fractionated subpopulations of PBMC in flow cytometory revealed that LPS accelerated the butyric acid-induced CD3+-T-cell apoptosis followed by similar levels of both CD4+- and CD8+-T-cell apoptosis. The addition of LPS to PBMC cultures did not cause DNA fragmentation, suggesting that LPS was unable to induce PBMC apoptosis directly. These data suggest that LPS, in combination with butyric acid, potentiates CD3+ PBMC T-cell apoptosis and plays a role in the apoptotic depletion of CD4+ and CD8+ cells. PMID:9864191

  14. Agarol, an ergosterol derivative from Agaricus blazei, induces caspase-independent apoptosis in human cancer cells.

    PubMed

    Shimizu, Takamitsu; Kawai, Junya; Ouchi, Kenji; Kikuchi, Haruhisa; Osima, Yoshiteru; Hidemi, Rikiishi

    2016-04-01

    Agaricus blazei (A. blazei) is a mushroom with many biological effects and active ingredients. We purified a tumoricidal substance from A. blazei, an ergosterol derivative, and named it 'Agarol'. Cytotoxic effects of Agarol were determined by the MTT assay using A549, MKN45, HSC-3, and HSC-4 human carcinoma cell lines treated with Agarol. Apoptosis was detected by flow cytometry analysis. Reactive oxygen species (ROS) levels and mitochondria membrane potential (∆ψm) were also determined by flow cytometry. Western blot analysis was used to quantify the expression of apoptosis-related proteins. Agarol predominantly induced apoptosis in two p53-wild cell lines (A549 and MKN45) compared to the other p53-mutant cell lines (HSC-3 and HSC-4). Further mechanistic studies revealed that induction of apoptosis is associated with increased generation of ROS, reduced ∆ψm, release of apoptosis-inducing factor (AIF) from the mitochondria to the cytosol, upregulation of Bax, and downregulation of Bcl-2. Caspase-3 activities did not increase, and z-VAD-fmk, a caspase inhibitor, did not inhibit the Agarol-induced apoptosis. These findings indicate that Agarol induces caspase-independent apoptosis in human carcinoma cells through a mitochondrial pathway. The in vivo anticancer activity of Agarol was confirmed in a xenograft murine model. This study suggests a molecular mechanism by which Agarol induces apoptosis in human carcinoma cells and indicates the potential use of Agarol as an anticancer agent.

  15. Par-4/NF-κB Mediates the Apoptosis of Islet β Cells Induced by Glucolipotoxicity

    PubMed Central

    QiNan, Wu; XiaGuang, Gan; XiaoTian, Lei; WuQuan, Deng; Ling, Zhang; Bing, Chen

    2016-01-01

    Apoptosis of islet β cells is a primary pathogenic feature of type 2 diabetes, and ER stress and mitochondrial dysfunction play important roles in this process. Previous research has shown that prostate apoptosis response-4 (Par-4)/NF-κB induces cancer cell apoptosis through endoplasmic reticulum (ER) stress and mitochondrial dysfunction. However, the mechanism by which Par-4/NF-κB induces islet β cell apoptosis remains unknown. We used a high glucose/palmitate intervention to mimic type 2 diabetes in vitro. We demonstrated that the high glucose/palmitate intervention induced the expression and secretion of Par-4. It also causes increased expression and activation of NF-κB, which induced NIT-1 cell apoptosis and dysfunction. Overexpression of Par-4 potentiates these effects, whereas downregulation of Par-4 attenuates them. Inhibition of NF-κB inhibited the Par-4-induced apoptosis. Furthermore, these effects occurred through the ER stress cell membrane and mitochondrial pathway of apoptosis. Our findings reveal a novel role for Par-4/NF-κB in islet β cell apoptosis and type 2 diabetes. PMID:27340675

  16. Apigenin induces apoptosis by targeting inhibitor of apoptosis proteins and Ku70-Bax interaction in prostate cancer.

    PubMed

    Shukla, Sanjeev; Fu, Pingfu; Gupta, Sanjay

    2014-05-01

    Dysfunction of the apoptotic pathway in prostate cancer cells confers apoptosis resistance towards various therapies. A novel strategy to overcome resistance is to directly target the apoptotic pathway in cancer cells. Apigenin, an anticancer agent, selectively toxic to cancer cells induces cell cycle arrest and apoptosis through mechanisms which are not fully explored. In the present study we provide novel insight into the mechanisms of apoptosis induction by apigenin. Treatment of androgen-refractory human prostate cancer PC-3 and DU145 cells with apigenin resulted in dose-dependent suppression of XIAP, c-IAP1, c-IAP2 and survivin protein levels. Apigenin treatment resulted in significant decrease in cell viability and apoptosis induction with the increase of cytochrome C in time-dependent manner. These effects of apigenin were accompanied by decrease in Bcl-xL and Bcl-2 and increase in the active form of Bax protein. The apigenin-mediated increase in Bax was due to dissociation of Bax from Ku70 which is essential for apoptotic activity of Bax. Apigenin treatment resulted in the inhibition of class I histone deacetylases and HDAC1 protein expression, thereby increasing the acetylation of Ku70 and the dissociation of Bax resulting in apoptosis of cancer cells. Furthermore, apigenin significantly reduced HDAC1 occupancy at the XIAP promoter, suggesting that histone deacetylation might be critical for XIAP downregulation. These results suggest that apigenin targets inhibitor of apoptosis proteins and Ku70-Bax interaction in the induction of apoptosis in prostate cancer cells and in athymic nude mouse xenograft model endorsing its in vivo efficacy.

  17. MicroRNA-322 protects hypoxia-induced apoptosis in cardiomyocytes via BDNF gene

    PubMed Central

    Yang, Liguo; Song, Shigang; Lv, Hang

    2016-01-01

    Background: Cardiomyocytes apoptosis under hypoxia condition contributes significantly to various cardiovascular diseases. In this study, we investigated the role of microRNA-322 (miR-322) in regulating hypoxia-induced apoptosis in neonatal murine cardiomyocytes in vitro. Method: Cardiomyocytes of C57BL/6J mice were treated with hypoxia condition in vitro. Cardiomyocyte apoptosis was measured by TUNEL assay. Gene expression pattern of miR-322 was measured by qRT-PCR. Stable downregulation of miR-322 in cardiomyocytes were achieved by lentiviral transduction, and the effect of miR-322 downregulation on hypoxia-induced cardiomyocyte apoptosis was investigated. Possible regulation of miR-322 on its downstream target gene, brain derived neurotrophic factor (BDNF) was investigated in cardiomyocytes. BDNF was then genetically silenced by siRNA to evaluate its role in miR-137 mediated cardiomyocyte apoptosis protection under hypoxia condition. Results: Under hypoxia condition, significant apoptosis was induced and miR-322 was significantly upregulated in cardiomyocytes in vitro. Through lentiviral transduction, miR-322 was efficiently knocked down in cardiomyocytes. Downregulation of miR-322 protected hypoxia-induced cardiomyocyte apoptosis. Luciferase assay showed BDNF was the target gene of miR-322. QRT-PCR showed BDNF expression was associated with miR-322 regulation on hypoxia-induced cardiomyocyte apoptosis. Silencing BDNF in cardiomyocyte through siRNA transfection reversed the protective effect of miR-322 downregulation on hypoxia-induced apoptosis. Conclusion: Our study revealed that miR-322, in association with BDNF, played important role in regulating hypoxia-induced apoptosis in cardiomyocyte. PMID:27398164

  18. The C. elegans TIA-1/TIAR homolog TIAR-1 is required to induce germ cell apoptosis.

    PubMed

    Silva-García, Carlos Giovanni; Estela Navarro, Rosa

    2013-10-01

    In Caenorhabditis elegans, physiological germ cell apoptosis eliminates more than half of the cells in the hermaphrodite gonad to support gamete quality and germline homeostasis by a still unidentified mechanism. External factors can also affect germ cell apoptosis. The BH3-only protein EGL-1 induces germ cell apoptosis when animals are exposed to pathogens or agents that produce DNA damage. DNA damage-induced apoptosis also requires the nematode p53 homolog CEP-1. Previously, we found that heat shock, oxidative, and osmotic stresses induce germ cell apoptosis through an EGL-1 and CEP-1 independent mechanism that requires the MAPKK pathway. However, we observed that starvation increases germ cell apoptosis by an unknown pathway. Searching for proteins that participate in stress-induced apoptosis, we found the RNA-binding protein TIAR-1 (a homolog of the mammalian TIA-1/TIAR family of proteins). Here, we show that TIAR-1 in C. elegans is required to induce apoptosis in the germline under several conditions. We also show that TIAR-1 acts downstream of CED-9 (a BCL2 homolog) to induce apoptosis under stress conditions, and apparently does not seem to regulate ced-4 or ced-3 mRNAs accumulation directly. TIAR-1 is expressed ubiquitously in the cytoplasm of the soma as well as the germline, where it sometimes associates with P granules. We show that animals lacking TIAR-1 expression are temperature sensitive sterile due to oogenesis and spermatogenesis defects. Our work shows that TIAR-1 is required for proper germline function and demonstrates that this protein is important to induce germ cell apoptosis under several conditions.

  19. The Mitochondria-Mediate Apoptosis of Lepidopteran Cells Induced by Azadirachtin

    PubMed Central

    Huang, Jingfei; Lv, Chaojun; Hu, Meiying; Zhong, Guohua

    2013-01-01

    Mitochondria have been shown to play an important role in apoptosis using mammalian cell lines. However, this seems not to be the case in Drosophila, an insect model organism; thus more in-depth studies of insect cell apoptosis are necessary. In the present study, mitochondrial involvement during azadirachtin- and camptothecin-induced apoptosis in Spodoptera frugiperda Sf9 cells (isolated from Spodoptera frugiperda pupal ovarian tissue) was investigated. The results showed that both azadirachtin and camptothecin could induce apoptosis in Sf9 cells. Reactive oxygen species (ROS) generation, activation of mitochondrial permeability transition pores (MPTPs) and loss of mitochondrial membrane potential (MMP) were observed very early during apoptosis and were followed subsequently by the release of cytochrome-c from the mitochondria. Furthermore, the results also revealed that the opening of MPTPs and the loss of MMP induced by azadirachtin could be significantly inhibited by the permeability transition pore (PTP) inhibitor cyclosporin A (CsA), which was used to identify the key role of mitochondria in the apoptosis of Sf9 cells. However, in camptothecin-treated Sf9 cells, CsA could not suppress the opening of MPTPs and the loss of MMP when apoptosis was induced. The data from caspase-3 and caspase-9 activity assays and detection of apoptosis by morphological observation and flow cytometry also uncovered the different effect of CsA on the two botanical apoptosis inducers. Although different mechanisms of apoptosis induction exist, our study revealed that mitochondria play a crucial role in insect cell line apoptosis. PMID:23516491

  20. Lysophosphatidic acid rescues bone mesenchymal stem cells from hydrogen peroxide-induced apoptosis.

    PubMed

    Wang, Xian-Yun; Fan, Xue-Song; Cai, Lin; Liu, Si; Cong, Xiang-Feng; Chen, Xi

    2015-03-01

    The increase of reactive oxygen species in infracted heart significantly reduces the survival of donor mesenchymal stem cells, thereby attenuating the therapeutic efficacy for myocardial infarction. In our previous study, we demonstrated that lysophosphatidic acid (LPA) protects bone marrow-derived mesenchymal stem cells (BMSCs) against hypoxia and serum deprivation-induced apoptosis. However, whether LPA protects BMSCs from H2O2-induced apoptosis was not examined. In this study, we report that H2O2 induces rat BMSC apoptosis whereas LPA pre-treatment effectively protects BMSCs from H2O2-induced apoptosis. LPA protection of BMSC from the induced apoptosis is mediated mostly through LPA3 receptor. Furthermore, we found that membrane G protein Gi2 and Gi3 are involved in LPA-elicited anti-apoptotic effects through activation of ERK1/2- and PI3 K-pathways. Additionally, H2O2 increases levels of type II of light chain 3B (LC3B II), an autophagy marker, and H2O2-induced autophagy thus protected BMSCs from apoptosis. LPA further increases the expression of LC3B II in the presence of H2O2. In contrast, autophagy flux inhibitor bafilomycin A1 has no effect on LPA's protection of BMSC from H2O2-induced apoptosis. Taken together, our data suggest that LPA rescues H2O2-induced apoptosis mainly by interacting with Gi-coupled LPA3, resulting activation of the ERK1/2- and PI3 K/AKT-pathways and inhibition caspase-3 cleavage, and LPA protection of BMSCs against the apoptosis is independent of it induced autophagy.

  1. Activation of CD95 (APO-1/Fas) signaling by ceramide mediates cancer therapy-induced apoptosis.

    PubMed Central

    Herr, I; Wilhelm, D; Böhler, T; Angel, P; Debatin, K M

    1997-01-01

    We report here that anticancer drugs such as doxorubicin lead to induction of the CD95 (APO-1/Fas) system of apoptosis and the cellular stress pathway which includes JNK/SAPKs. Ceramide, which accumulates in response to different types of cellular stress such as chemo- and radiotherapy, strongly induced expression of CD95-L, cleavage of caspases and apoptosis. Antisense CD95-L as well as dominant-negative FADD inhibited ceramide- and cellular stress-induced apoptosis. Fibroblasts from type A Niemann-Pick patients (NPA), genetically deficient in ceramide synthesis, failed to up-regulate CD95-L expression and to undergo apoptosis after gamma-irradiation or doxorubicin treatment. In contrast, JNK/SAPK activity was still inducible by doxorubicin in the NPA cells, suggesting that activation of JNK/SAPKs alone is not sufficient for induction of the CD95 system and apoptosis. CD95-L expression and apoptosis in NPA fibroblasts were restorable by exogenously added ceramide. In addition, NPA fibroblasts undergo apoptosis after triggering of CD95 with an agonistic antibody. These data demonstrate that ceramide links cellular stress responses induced by gamma-irradiation or anticancer drugs to the CD95 pathway of apoptosis. PMID:9321399

  2. Grape seed proanthocyanidin extract protects lymphocytes against histone-induced apoptosis

    PubMed Central

    Chang, Ping; Mo, Bing; Cauvi, David M.; Yu, Ying; Guo, Zhenhui; Zhou, Jian; Huang, Qiong; Yan, Qitao; Chen, Guiming

    2017-01-01

    Apoptosis of lymphocytes is associated with immunosuppression and poor prognosis in sepsis. Our previous report showed that histones, nuclear proteins released from damaged or dying cells in sepsis, can mediate lymphocyte apoptosis via mitochondria damage. Grape seed proanthocyanidin extract (GSPE), a natural substance with protective properties against oxidative stress, plays a vital role in cell and mitochondria protection. We thus hypothesized that GSPE may play a protective role in histone-induced lymphocyte apoptosis through its anti-oxidative properties. In this study, we investigated the protective efficacy of GSPE on lymphocyte apoptosis induced by extracellular histones, a main contributor of death in sepsis. Human blood lymphocytes were treated with 50 μg/ml histones, 2 μg/ml GSPE, or a combination of both. A total of 100 μM N-acetylcysteine (NAC), a reactive oxygen species (ROS) inhibitor, was used as a positive control for GSPE. Apoptosis, intracellular ROS levels, mitochondrial membrane potential, Bcl-2 expression, and caspase-3 cleavage were measured. Our data clearly indicate that GSPE significantly inhibited lymphocyte apoptosis, generation of ROS, the loss of mitochondrial membrane potential, the decrease in Bcl-2 expression, and caspase-3 activation induced by extracellular histones. In conclusion, we show that GSPE has a protective effect on lymphocyte apoptosis induced by extracellular histones. This study suggests GSPE as a potential therapeutic agent that could help reduce lymphocyte apoptosis, and thus the state of immunosuppression was observed in septic patients. PMID:28344907

  3. Bim is a crucial regulator of apoptosis induced by Mycobacterium tuberculosis

    PubMed Central

    Aguiló, N; Uranga, S; Marinova, D; Martín, C; Pardo, J

    2014-01-01

    Mycobacterium tuberculosis, the causative agent of tuberculosis, induces apoptosis in infected macrophages in vitro and in vivo. However, the molecular mechanism controlling this process is not known. In order to study the involvement of the mitochondrial apoptotic pathway in M. tuberculosis-induced apoptosis, we analysed cell death in M. tuberculosis-infected embryonic fibroblasts (MEFs) derived from different knockout mice for genes involved in this route. We found that apoptosis induced by M. tuberculosis is abrogated in the absence of Bak and Bax, caspase 9 or the executioner caspases 3 and 7. Notably, we show that MEF deficient in the BH3-only BCL-2-interacting mediator of cell death (Bim) protein were also resistant to this process. The relevance of these results has been confirmed in the mouse macrophage cell line J774, where cell transfection with siRNA targeting Bim impaired apoptosis induced by virulent mycobacteria. Notably, only infection with a virulent strain, but not with attenuated ESX-1-defective strains, such as Bacillus Calmette-Guerin and live-attenuated M. tuberculosis vaccine strain MTBVAC, induced Bim upregulation and apoptosis, probably implicating virulence factor early secreted antigenic target 6-kDa protein in this process. Our results suggest that Bim upregulation and apoptosis is mediated by the p38MAPK-dependent pathway. Our findings show that Bim is a master regulator of apoptosis induced by M. tuberculosis. PMID:25032866

  4. Positive Feedback Cycle of TNFα Promotes Staphylococcal Enterotoxin B-Induced THP-1 Cell Apoptosis

    PubMed Central

    Zhang, Xiaopeng; Shang, Weilong; Yuan, Jizhen; Hu, Zhen; Peng, Huagang; Zhu, Junmin; Hu, Qiwen; Yang, Yi; Liu, Hui; Jiang, Bei; Wang, Yinan; Li, Shu; Hu, Xiaomei; Rao, Xiancai

    2016-01-01

    Staphylococcal enterotoxin B (SEB) has been demonstrated to be of importance in Staphylococcus aureus related diseases, such as atopic dermatitis (AD). Dysregulated apoptosis in AD is remarkable, and SEB can induce apoptosis of various cell types. However, the mechanisms by which SEB induces apoptosis and influences disease processes remain unclear. In this study, the recombinant SEB-induced THP-1 monocyte apoptosis was demonstrated in the absence of preliminary cell activation in a time- and dose-dependent manner. SEB could up-regulate the expression of tumor necrosis factor alpha (TNFα) in THP-1 cells and induce apoptosis via an extrinsic pathway. TNFα could in turn increase the expression of HLA-DRa, the SEB receptor on the cell surface. As a result, a positive feedback cycle of TNFα was established. TNFα expression and SEB-induced apoptosis were decreased by knocking down the expression of either HLA-DRa or TNFR1. Therefore, the feedback cycle of TNFα is crucial for SEB functions. This work provides insights into the mechanisms of SEB-induced monocyte apoptosis and emphasizes the major role of TNFα in future related studies. PMID:27709104

  5. Inhibition of proteasome activity is involved in cobalt-induced apoptosis of human alveolar macrophages.

    PubMed

    Araya, Jun; Maruyama, Muneharu; Inoue, Akira; Fujita, Tadashi; Kawahara, Junko; Sassa, Kazuhiko; Hayashi, Ryuji; Kawagishi, Yukio; Yamashita, Naohiro; Sugiyama, Eiji; Kobayashi, Masashi

    2002-10-01

    Inhalation of particulate cobalt has been known to induce interstitial lung disease. There is growing evidence that apoptosis plays a crucial role in physiological and pathological settings and that the ubiquitin-proteasome system is involved in the regulation of apoptosis. Cadmium, the same transitional heavy metal as cobalt, has been reported to accumulate ubiquitinated proteins in neuronal cells. On the basis of these findings, we hypothesized that cobalt would induce apoptosis in the lung by disturbance of the ubiquitin-proteasome pathway. To evaluate this, we exposed U-937 cells and human alveolar macrophages (AMs) to cobalt chloride (CoCl(2)) and examined their apoptosis by DNA fragmentation assay, 4',6-diamidino-2'-phenylindol dihydrochloride staining, and Western blot analysis. CoCl(2) induced apoptosis and accumulated ubiquitinated proteins. Exposure to CoCl(2) inhibited proteasome activity in U-937 cells. Cobalt-induced apoptosis was mediated via mitochondrial pathway because CoCl(2) released cytochrome c from mitochondria. These results suggest that cobalt-induced apoptosis of AMs may be one of the mechanisms for cobalt-induced lung injury and that the accumulation of ubiquitinated proteins might be involved in this apoptotic process.

  6. Kaurene diterpene induces apoptosis in human leukemia cells partly through a caspase-8-dependent pathway.

    PubMed

    Kondoh, Masuo; Suzuki, Ikue; Sato, Masao; Nagashima, Fumihiro; Simizu, Siro; Harada, Motoki; Fujii, Makiko; Osada, Hiroyuki; Asakawa, Yoshinori; Watanabe, Yoshiteru

    2004-10-01

    Defects in apoptosis signaling pathways contribute to tumorigenesis and drug resistance, and these defects are often a cause of failure of chemotherapy. Thus, a major goal in chemotherapy is to find cytotoxic agents that restore the ability of tumor cells to undergo apoptosis. We previously found that an Ent-kaurene diterpene, Ent-11alpha-hydroxy-16-kauren-15-one (KD), induced apoptosis in human promyelocytic leukemia HL-60 cells. Here, we found that caspase-8, an apoptotic factor, is involved in KD-induced apoptosis. Although treatment of HL-60 cells with KD resulted in the activation of caspase-8 and -9, a caspase-8-specific inhibitor but not a caspase-9-specific inhibitor attenuated KD-induced apoptosis. Expression of a catalytically inactive caspase-8 partly attenuated KD-induced apoptosis. Treatment with KD led to a time-dependent cleavage of Bid, a substrate of caspase-8, as well as to the proteolytic processing of procaspase-8, indicating that KD treatment induces apoptosis through a caspase-8-dependent pathway. Moreover, overexpression of the drug resistance factor Bcl-2, which is frequently overexpressed in many tumors, failed to confer resistance to KD-induced cytotoxicity. Thus, KD may be a promising experimental cytotoxic agent that possibly points to new strategies to overcome a drug resistance.

  7. Carbamate pesticide-induced apoptosis and necrosis in human natural killer cells.

    PubMed

    Li, Q; Kobayashi, M; Kawada, T

    2014-01-01

    We previously found that ziram, a carbamate fungicide, significantly induced apoptosis and necrosis in human NK-92MI, a natural killer cell line. To investigate whether other carbamate pesticides also induce apoptosis and necrosis in human natural killer cell, we conducted further experiments with NK-92CI, a human natural killer cell line using a more sensitive assay. NK-92CI cells were treated with ziram, thiram, maneb or carbaryl at 0.031-40 microM for 2-24 h in the present study. Apoptosis and necrosis were determined by FITC-Annexin-V/PI staining. To explore the mechanism of apoptosis, intracellular levels of active caspases 3 and mitochondrial cytochrome-c release were determined by flow cytometry. We found that ziram and thiram also induced apoptosis and necrosis in a time- and dose-dependent manner; however, maneb and carbaryl induced apoptosis and necrosis only at higher doses in NK-92CI cells. The strength of the apoptosis-inducing effect differed among the pesticides, and the order was as follows: thiram > ziram greater than maneb greater than carbaryl. NK-92CI was more sensitive to ziram than NK-92MI. Moreover, ziram and thiram significantly increased the intracellular level of active caspase 3 in NK-92CI and caspase inhibitor significantly inhibited the apoptosis. Ziram and thiram significantly caused mitochondrial cytochrome-c release in NK-92CI. These findings indicate that carbamate pesticides can induce apoptosis in natural killer cells, and the apoptosis is mediated by both the caspase-cascade and mitochondrial cytochrome-c pathways.

  8. Global Analysis of Posttranscriptional Gene Expression in Response to Sodium Arsenite

    PubMed Central

    Qiu, Lian-Qun; Abey, Sarah; Harris, Shawn; Shah, Ruchir; Gerrish, Kevin E.

    2014-01-01

    Background: Inorganic arsenic species are potent environmental toxins and causes of numerous health problems. Most studies have assumed that arsenic-induced changes in mRNA levels result from effects on gene transcription. Objectives: We evaluated the prevalence of changes in mRNA stability in response to sodium arsenite in human fibroblasts. Methods: We used microarray analyses to determine changes in steady-state mRNA levels and mRNA decay rates following 24-hr exposure to noncytotoxic concentrations of sodium arsenite, and we confirmed some of these changes using real-time reverse-transcription polymerase chain reaction (RT-PCR). Results: In arsenite-exposed cells, 186 probe set–identified transcripts were significantly increased and 167 were significantly decreased. When decay rates were analyzed after actinomycin D treatment, only 4,992 (9.1%) of probe set–identified transcripts decayed by > 25% after 4 hr. Of these, 70 were among the 353 whose steady-state levels were altered by arsenite, and of these, only 4 exhibited significantly different decay rates between arsenite and control treatment. Real-time RT-PCR confirmed a major, significant arsenite-induced stabilization of the mRNA encoding δ aminolevulinate synthase 1 (ALAS1), the rate-limiting enzyme in heme biosynthesis. This change presumably accounted for at least part of the 2.7-fold increase in steady-state ALAS1 mRNA levels seen after arsenite treatment. This could reflect decreases in cellular heme caused by the massive induction by arsenite of heme oxygenase mRNA (HMOX1; 68-fold increase), the rate-limiting enzyme in heme catabolism. Conclusions: We conclude that arsenite modification of mRNA stability is relatively uncommon, but in some instances can result in significant changes in gene expression. Citation: Qiu LQ, Abey S, Harris S, Shah R, Gerrish KE, Blackshear PJ. 2015. Global analysis of posttranscriptional gene expression in response to sodium arsenite. Environ Health Perspect 123:324

  9. Endocannabinoids participate in placental apoptosis induced by hypoxia inducible factor-1.

    PubMed

    Abán, C; Martinez, N; Carou, C; Albamonte, I; Toro, A; Seyahian, A; Franchi, A; Leguizamón, G; Trigubo, D; Damiano, A; Farina, M

    2016-10-01

    During pregnancy, apoptosis is a physiological event critical in the remodeling and aging of the placenta. Increasing evidence has pointed towards the relevance of endocannabinoids (ECs) and hypoxia as modulators of trophoblast cell death. However, the relation between these factors is still unknown. In this report, we evaluated the participation of ECs in placental apoptosis induced by cobalt chloride (CoCl2), a hypoxia mimicking agent that stabilizes the expression of hypoxia inducible factor-1 alpha (HIF-1α). We found that HIF-1α stabilization decreased FAAH mRNA and protein levels, suggesting an increase in ECs tone. Additionally, CoCl2 incubation and Met-AEA treatment reduced cell viability and increased TUNEL-positive staining in syncytiotrophoblast layer. Immunohistochemical analysis demonstrated Bax and Bcl-2 protein expression in the cytoplasm of syncytiotrophoblast. Finally, HIF-1α stabilization produced an increase in Bax/Bcl-2 ratio, activation of caspase 3 and PARP cleavage. All these changes in apoptotic parameters were reversed with AM251, a CB1 antagonist. These results demonstrate that HIF-1α may induce apoptosis in human placenta via intrinsic pathway by a mechanism that involves activation of CB1 receptor suggesting a role of the ECs in this process.

  10. Effects of parabens on apoptosis induced by serum-free medium.

    PubMed

    Egawa, Mari; Aoki, Kentaro; Sun, Yongkun; Hosokawa, Toshiyuki; Saito, Takeshi; Kurasaki, Masaaki

    2012-01-01

    Alkyl esters of p-hydroxybenzoic acids (parabens), an endocrine disrupter, are used as preservatives in cosmetics and foods. In this study, to understand the relationship between parabens and differentiation in infants, the effects of parabens on apoptosis induced by serum deprivation in PC12 cells were investigated. In addition, apoptosis-related factors were assayed. As results, a tendency toward enhancement of apoptosis was observed in the cells cultured in the serum-free medium with methylparaben, and this tendency was suggested to be related to the contents of BAD, a pro-apoptotic protein. Butylparaben did not show any tendency to enhance apoptosis.

  11. Experimental study on apoptosis induced by semiconductor laser to hair removal and armpit odor treatment

    NASA Astrophysics Data System (ADS)

    Shi, Hongmin; Yan, Min; Zhang, Meijue

    2005-07-01

    Objective: To observe and explore the effects and mechanism of apoptosis on canine induced by Laser. Try to find a new approach to treat of armpit odor with no traumatism. Method: We used different power of semiconductor Laser to irradiate the black hair canine to observe and evaluate the tissue effects with electroscope, flow cytometry and Tunel technique at different period of time after irradiation. Result: The apoptosis has been observed within the hair follicle cells and apocrine gland cells after irradiation. After repeat irradiation in low power level, more apoptosis has been observed. Conclusion: Apoptosis exists in hair follicle cells and apocrine gland cells after Laser irradiation.

  12. Novel fluorescence molecular imaging of chemotherapy-induced intestinal apoptosis

    NASA Astrophysics Data System (ADS)

    Levin, Galit; Shirvan, Anat; Grimberg, Hagit; Reshef, Ayelet; Yogev-Falach, Merav; Cohen, Avi; Ziv, Ilan

    2009-09-01

    Chemotherapy-induced enteropathy (CIE) is one of the most serious complications of anticancer therapy, and tools for its early detection and monitoring are highly needed. We report on a novel fluorescence method for detection of CIE, based on molecular imaging of the related apoptotic process. The method comprises systemic intravenous administration of the ApoSense fluorescent biomarker (N,N'-didansyl-L-cystine DDC) in vivo and subsequent fluorescence imaging of the intestinal mucosa. In the reported proof-of-concept studies, mice were treated with either taxol+cyclophosphamide or doxil. DDC was administered in vivo at various time points after drug administration, and tracer uptake by ileum tissue was subsequently evaluated by ex vivo fluorescent microscopy. Chemotherapy caused marked and selective uptake of DDC in ileal epithelial cells, in correlation with other hallmarks of apoptosis (i.e., DNA fragmentation and Annexin-V binding). Induction of DDC uptake occurred early after chemotherapy, and its temporal profile was parallel to that of the apoptotic process, as assessed histologically. DDC may therefore serve as a useful tool for detection of CIE. Future potential integration of this method with fluorescent endoscopic techniques, or development of radio-labeled derivatives of DDC for emission tomography, may advance early diagnosis and monitoring of this severe adverse effect of chemotherapy.

  13. Role of the human heat shock protein hsp70 in protection against stress-induced apoptosis.

    PubMed Central

    Mosser, D D; Caron, A W; Bourget, L; Denis-Larose, C; Massie, B

    1997-01-01

    Resistance to stress-induced apoptosis was examined in cells in which the expression of hsp70 was either constitutively elevated or inducible by a tetracycline-regulated transactivator. Heat-induced apoptosis was blocked in hsp70-expressing cells, and this was associated with reduced cleavage of the common death substrate protein poly(ADP-ribose) polymerase (PARP). Heat-induced cell death was correlated with the activation of the stress-activated protein kinase SAPK/JNK (c-Jun N-terminal kinase). Activation of SAPK/JNK was strongly inhibited in cells in which hsp70 was induced to a high level, indicating that hsp70 is able to block apoptosis by inhibiting signaling events upstream of SAPK/JNK activation. In contrast, SAPK/JNK activation was not inhibited by heat shock in cells with constitutively elevated levels of hsp70. Cells that constitutively overexpress hsp70 resist apoptosis induced by ceramide, a lipid signaling molecule that is generated by apoptosis-inducing treatments and is linked to SAPK/JNK activation. Similar to heat stress, resistance to ceramide-induced apoptosis occurs in spite of strong SAPK/JNK activation. Therefore, hsp70 is also able to inhibit apoptosis at some point downstream of SAPK/JNK activation. Since PARP cleavage is prevented in both cell lines, these results suggest that hsp70 is able to prevent the effector steps of apoptotic cell death. Processing of the CED-3-related protease caspase-3 (CPP32/Yama/apopain) is inhibited in hsp70-expressing cells; however, the activity of the mature enzyme is not affected by hsp70 in vitro. Caspase processing may represent a critical heat-sensitive target leading to cell death that is inhibited by the chaperoning function of hsp70. The inhibition of SAPK/JNK signaling and apoptotic protease effector steps by hsp70 likely contributes to the resistance to stress-induced apoptosis seen in transiently induced thermotolerance. PMID:9271409

  14. 14-3-3 Protects against stress-induced apoptosis

    PubMed Central

    Clapp, C; Portt, L; Khoury, C; Sheibani, S; Norman, G; Ebner, P; Eid, R; Vali, H; Mandato, C A; Madeo, F; Greenwood, M T

    2012-01-01

    Expression of human Bax, a cardinal regulator of mitochondrial membrane permeabilization, causes death in yeast. We screened a human cDNA library for suppressors of Bax-mediated yeast death and identified human 14-3-3β/α, a protein whose paralogs have numerous chaperone-like functions. Here, we show that, yeast cells expressing human 14-3-3β/α are able to complement deletion of the endogenous yeast 14-3-3 and confer resistance to a variety of different stresses including cadmium and cycloheximide. The expression of 14-3-3β/α also conferred resistance to death induced by the target of rapamycin inhibitor rapamycin and by starvation for the amino acid leucine, conditions that induce autophagy. Cell death in response to these autophagic stimuli was also observed in the macroautophagic-deficient atg1Δ and atg7Δ mutants. Furthermore, 14-3-3β/α retained its ability to protect against the autophagic stimuli in these autophagic-deficient mutants arguing against so called ‘autophagic death'. In line, analysis of cell death markers including the accumulation of reactive oxygen species, membrane integrity and cell surface exposure of phosphatidylserine indicated that 14-3-3β/α serves as a specific inhibitor of apoptosis. Finally, we demonstrate functional conservation of these phenotypes using the yeast homolog of 14-3-3: Bmh1. In sum, cell death in response to multiple stresses can be counteracted by 14-3-3 proteins. PMID:22785534

  15. Genotoxic effects of sodium arsenite and sodium arsenate after chronic exposure of Drosophila melanogaster larvae

    SciTech Connect

    Ramos-Morales, P.; Ordaz, M.G.; Munoz, A.

    1995-11-01

    Two arsenic compounds, namely: NaAsO{sub 2} (Sodium Arsenite) and Na{sub 2}HAsO{sub 4} (Sodium Arsenate) were tested for its chronic effect in somatic cells of Drosophila melanogaster. In a previous study in Drosophila we found that both compounds induced SLRL mutations, but failed to induce sex chromosome loss. In the SMART, after acute exposure, only sodium arsenite was positive when cells of the wings were used; however, both were positives in cells of the eyes of Drosophila. The genotoxicity of both compounds localized mainly on somatic cells, in agreement with reports on the carcinogenicity potential of arsenical compounds. The Somatic mutation and recombination test (SMART) was run employing cells of the wing imaginal discs from flr{sup 3}/mwh larvae. First instar larvae (24 {plus_minus} 4 h) were treated during 96 hours with sodium arsenite [0.015-4.0 ppm], and sodium arsenate [0.2-10 ppm], negative control was treated with distilled water. The frequency of spots by wing induced by the two arsenic salts were compared with control according with Frei and Wuergler procedure. Data show that sodium arsenite tested negative at all concentrations, but sodium arsenate tested positive at 0.8, 2 and 10 ppm (P<0.05). This results were consistent with the co-mutagenic role of sodium arsenite, but show that sodium arsenate was mutagenic in Drosophila test system under chronic exposure.

  16. New Hypotheses and Opportunities in Endocrine Therapy: Amplification of Oestrogen-Induced Apoptosis

    PubMed Central

    Jordan, V. Craig; Lewis-Wambi, Joan S.; Patel, Roshani R.; Kim, Helen; Ariazi, Eric A.

    2010-01-01

    Aims To outline the progress being made in the understanding of acquired resistance to long term therapy with the selective oestrogen receptor modulators (SERMs, tamoxifen and raloxifene) and aromatase inhibitors. The question to be addressed is how we can amplify the new biology of oestrogen-induced apoptosis to create more complete responses in exhaustively antihormone treated metastatic breast cancer. Methods and Results Three questions are posed and addressed. 1.) Do we know how oestrogen works? 2.) Can we improve adjuvant antihormonal therapy? 3.) Can we enhance oestrogen-induced apoptosis? The new player in oestrogen action is GPR30 and there are new drugs specific for this target to trigger apoptosis. Similarly, anti-angiogenic drugs can be integrated into adjuvant antihormone therapy or to enhance oestrogen-induced apoptosis in Phase II antihormone resistant breast cancer. The goal is to reduce the development of acquired antihormone resistance or undermine the ability of breast cancer cells to undergo apoptosis with oestrogen respectively. Finally, drugs to reduce the synthesis of glutathione, a subcellular molecule compound associated with drug resistance, can enhance oestradiol-induced apoptosis. Conclusions We propose an integrated approach for the rapid testing of agents to blunt survival pathways and amplify oestrogen-induced apoptosis and tumour regression in Phase II resistant metastatic breast cancer. This Pharma platform will provide rapid clinical results to predict efficacy in large scale clinical trials. PMID:19914527

  17. Cocaine Enhances HIV-1–Induced CD4+ T-Cell Apoptosis

    PubMed Central

    Pandhare, Jui; Addai, Amma B.; Mantri, Chinmay K.; Hager, Cynthia; Smith, Rita M.; Barnett, Louis; Villalta, Fernando; Kalams, Spyros A.; Dash, Chandravanu

    2015-01-01

    Substance abuse is a major barrier in eradication of the HIV epidemic because it serves as a powerful cofactor for viral transmission, disease progression, and AIDS-related mortality. Cocaine, one of the commonly abused drugs among HIV-1 patients, has been suggested to accelerate HIV disease progression. However, the underlying mechanism remains largely unknown. Therefore, we tested whether cocaine augments HIV-1–associated CD4+ T-cell decline, a predictor of HIV disease progression. We examined apoptosis of resting CD4+ T cells from HIV-1–negative and HIV-1–positive donors in our study, because decline of uninfected cells plays a major role in HIV-1 disease progression. Treatment of resting CD4+ T cells with cocaine (up to 100 μmol/L concentrations) did not induce apoptosis, but 200 to 1000 μmol/L cocaine induced apoptosis in a dose-dependent manner. Notably, treatment of CD4+ T cells isolated from healthy donors with both HIV-1 virions and cocaine significantly increased apoptosis compared with the apoptosis induced by cocaine or virions alone. Most important, our biochemical data suggest that cocaine induces CD4+ T-cell apoptosis by increasing intracellular reactive oxygen species levels and inducing mitochondrial depolarization. Collectively, our results provide evidence of a synergy between cocaine and HIV-1 on CD4+ T-cell apoptosis that may, in part, explain the accelerated disease observed in HIV-1–infected drug abusers. PMID:24486327

  18. Bupivacaine induces apoptosis through caspase-dependent and -independent pathways in canine mammary tumor cells.

    PubMed

    Chiu, Yi-Shu; Cheng, Yeong-Hsiang; Lin, Sui-Wen; Chang, Te-Sheng; Liou, Chian-Jiun; Lai, Yu-Shen

    2015-06-01

    Local anesthetics have been reported to induce apoptosis in various cell lines. In this study, we showed that bupivacaine also induced apoptosis in DTK-SME cells, a vimentin(+)/AE1(+)/CK7(+)/HSP27(+), tumorigenic, immortalized, canine mammary tumor cell line. Bupivacaine induced apoptosis in DTK-SME cells in a time- and concentration-dependent manner. Apoptosis-associated morphological changes, including cell shrinkage and rounding, chromatin condensation, and formation of apoptotic bodies, were observed in the bupivacaine-treated DTK-SME cells. Apoptosis was further confirmed with annexin V staining, TUNEL staining, and DNA laddering assays. At the molecular level, the activation of caspases-3, -8, and -9 corresponded well to the degree of DNA fragmentation triggered by bupivacaine. We also demonstrated that the pan-caspase inhibitor, z-VAD-fmk, only partially inhibited the apoptosis induced by bupivacaine. Moreover, treated cells increased expression of endonuclease G, a death effector that acts independently of caspases. Our data suggested that bupivacaine-induced apoptosis occurs through both caspase-dependent and caspase-independent apoptotic pathways.

  19. Apoptosis of rat hepatic stellate cells induced by diallyl trisulfide and proteomics profiling in vitro.

    PubMed

    Zhang, Yajie; Zhou, Xiaoming; Xu, Lipeng; Wang, Lulu; Liu, Jinling; Ye, Jing; Qiu, Pengxin; Liu, Qinghua

    2016-11-18

    Diallyl trisulfide (DATS), a major garlic derivative, inhibits cell proliferation and triggers apoptosis in a variety of cancer cell lines. However, the effects of DATS on hepatic stellate cells (HSCs) remain unknown. The aim of this study was to analyze the effects of DATS on cell proliferation and apoptosis, as well as the protein expression profile in rat HSCs. Rat HSCs were treated with or without 12 and 24 μg/mL DATS for various time intervals. Cell proliferation and apoptosis were determined using tetrazolium dye (MTT) colorimetric assay, bromodeoxyuridine (5-bromo-2'-deoxyuridine; BrdU) assay, Hoechst 33342 staining, electroscopy, and flow cytometry. Protein expression patterns in HSCs were systematically studied using 2-dimensional electrophoresis and mass spectrometry. DATS inhibited cell proliferation and induced apoptosis of HSCs in a time-dependent manner. We observed clear morphological changes in apoptotic HSCs and dramatically increased annexin V-positive - propidium iodide negative apoptosis compared with the untreated control group. Twenty-one significant differentially expressed proteins, including 9 downregulated proteins and 12 upregulated proteins, were identified after DATS administration, and most of them were involved in apoptosis. Our results suggest that DATS is an inducer of apoptosis in HSCs, and several key proteins may be involved in the molecular mechanism of apoptosis induced by DATS.

  20. Inhibition of COX-2/PGE2 cascade ameliorates cisplatin-induced mesangial cell apoptosis

    PubMed Central

    Yu, Xiaowen; Yang, Yunwen; Yuan, Hui; Wu, Meng; Li, Shuzhen; Gong, Wei; Yu, Jing; Xia, Weiwei; Zhang, Yue; Ding, Guixia; Huang, Songming; Jia, Zhanjun; Zhang, Aihua

    2017-01-01

    Cisplatin is one of the most potent cytotoxic drug for the treatment of many types of cancer. However, the side effects on normal tissues, particularly on the kidney, greatly limited its use in clinic. Emerging evidence demonstrated that cisplatin could directly cause mesangial cell apoptosis, while the potential mechanism is still elusive. Here we examined the contribution of COX-2 in cisplatin-induced mesangial cell apoptosis. Firstly, we found cisplatin induced cell apoptosis in mesangial cells shown by increased number of apoptotic cells in parallel with the upregulation of Bax and the downregulation of Bcl-2. Interestingly, cisplatin-induced cell apoptosis was accompanied by an upregulation of COX-2 at both mRNA and protein levels in dose- and time-dependent manners. Importantly, inhibition of COX-2 via a specific COX-2 inhibitor celecoxib markedly blocked cisplatin-induced mesangial cell apoptosis as evidenced by the decreased number of apoptotic cells, blocked increments of cleaved caspase-3 and Bax, and reversed Bcl-2 downregulation. Meanwhile, cisplatin-induced PGE2 production was markedly blocked by the treatment of celecoxib. In conclusion, this study indicated that COX-2/PGE2 cascade activation mediated cisplatin-induced mesangial cell apoptosis. The findings not only offered new insights into the understanding of cisplatin nephrotoxicity but also provided the therapeutic potential by targeting COX-2/PGE2 cascade in treating cisplatin-induced kidney injury. PMID:28386348

  1. Involvement of Mst1 in tumor necrosis factor-{alpha}-induced apoptosis of endothelial cells

    SciTech Connect

    Ohtsubo, Hideki; Ichiki, Toshihiro Imayama, Ikuyo; Ono, Hiroki; Fukuyama, Kae; Hashiguchi, Yasuko; Sadoshima, Junichi; Sunagawa, Kenji

    2008-03-07

    Mammalian sterile 20-kinase 1 (Mst1), a member of the sterile-20 family protein kinase, plays an important role in the induction of apoptosis. However, little is know about the physiological activator of Mst1 and the role of Mst1 in endothelial cells (ECs). We examined whether Mst1 is involved in the tumor necrosis factor (TNF)-{alpha}-induced apoptosis of ECs. Western blot analysis revealed that TNF-{alpha} induced activation of caspase 3 and Mst1 in a time- and dose-dependent manner. TNF-{alpha}-induced Mst1 activation is almost completely prevented by pretreatment with Z-DEVD-FMK, a caspase 3 inhibitor. Nuclear staining with Hoechst 33258 and fluorescence-activated cell sorting of propidium iodide-stained cells showed that TNF-{alpha} induced apoptosis of EC. Diphenyleneiodonium, an inhibitor of NADPH oxidase, and N-acetylcysteine, a potent antioxidant, also inhibited TNF-{alpha}-induced activation of Mst1 and caspase 3, as well as apoptosis. Knockdown of Mst1 expression by short interfering RNA attenuated TNF-{alpha}-induced apoptosis but not cleavage of caspase 3. These results suggest that Mst1 plays an important role in the induction of TNF-{alpha}-induced apoptosis of EC. However, positive feedback mechanism between Mst1 and caspase 3, which was shown in the previous studies, was not observed. Inhibition of Mst1 function may be beneficial for maintaining the endothelial integrity and inhibition of atherogenesis.

  2. Ursodeoxycholic Acid Induces Death Receptor-mediated Apoptosis in Prostate Cancer Cells

    PubMed Central

    Lee, Won Sup; Jung, Ji Hyun; Panchanathan, Radha; Yun, Jeong Won; Kim, Dong Hoon; Kim, Hye Jung; Kim, Gon Sup; Ryu, Chung Ho; Shin, Sung Chul; Hong, Soon Chan; Choi, Yung Hyun; Jung, Jin-Myung

    2017-01-01

    Background Bile acids have anti-cancer properties in a certain types of cancers. We determined anticancer activity and its underlying molecular mechanism of ursodeoxycholic acid (UDCA) in human DU145 prostate cancer cells. Methods Cell viability was measured with an MTT assay. UDCA-induced apoptosis was determined with flow cytometric analysis. The expression levels of apoptosis-related signaling proteins were examined with Western blotting. Results UDCA treatment significantly inhibited cell growth of DU145 in a dose-dependent manner. It induced cellular shrinkage and cytoplasmic blebs and accumulated the cells with sub-G1 DNA contents. Moreover, UDCA activated caspase 8, suggesting that UDCA-induced apoptosis is associated with extrinsic pathway. Consistent to this finding, UDCA increased the expressions of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptor, death receptor 4 (DR4) and death receptor 5 (DR5), and TRAIL augmented the UDCA-induced cell death in DU145 cells. In addition, UDCA also increased the expressions of Bax and cytochrome c and decreased the expression of Bcl-xL in DU145 cells. This finding suggests that UDCA-induced apoptosis may be involved in intrinsic pathway. Conclusions UDCA induces apoptosis via extrinsic pathway as well as intrinsic pathway in DU145 prostate cancer cells. UDCA may be a promising anti-cancer agent against prostate cancer. PMID:28382282

  3. Valsartan protects HK-2 cells from contrast media-induced apoptosis by inhibiting endoplasmic reticulum stress.

    PubMed

    Peng, Ping-An; Wang, Le; Ma, Qian; Xin, Yi; Zhang, Ou; Han, Hong-Ya; Liu, Xiao-Li; Ji, Qing-Wei; Zhou, Yu-Jie; Zhao, Ying-Xin

    2015-12-01

    Contrast-induced acute kidney injury (CI-AKI) is associated with increasing in-hospital and long-term adverse clinical outcomes in high-risk patients undergoing percutaneous coronary intervention (PCI). Contrast media (CM)-induced renal tubular cell apoptosis is reported to participate in this process by activating endoplasmic reticulum (ER) stress. An angiotensin II type 1 receptor (AT1R) antagonist can alleviate ER stress-induced renal apoptosis in streptozotocin (STZ)-induced diabetic mice and can reduce CM-induced renal apoptosis by reducing oxidative stress and reversing the enhancement of bax mRNA and the reduction of bcl-2 mRNA, but the effect of the AT1R blocker on ER stress in the pathogenesis of CI-AKI is still unknown. In this study, we explored the effect of valsartan on meglumine diatrizoate-induced human renal tubular cell apoptosis by measuring changes in ER stress-related biomarkers. The results showed that meglumine diatrizoate caused significant cell apoptosis by up-regulating the expression of ER stress markers, including glucose-regulated protein 78 (GRP78), activating transcription factor 4 (ATF4), CCAAT/enhancer-binding protein-homologous protein (CHOP) and caspase 12, in a time- and dose-dependent manner, which could be alleviated by preincubation with valsartan. In conclusion, valsartan had a potential nephroprotective effect on meglumine diatrizoate-induced renal cell apoptosis by inhibiting ER stress.

  4. Farnesol induces apoptosis-like cell death in the pathogenic fungus Aspergillus flavus.

    PubMed

    Wang, Xiaoyun; Wang, Youzhi; Zhou, Yuguang; Wei, Xinli

    2014-01-01

    Farnesol (FOH) is known to induce apoptosis in some fungi and mammalian cells. We treated Aspergillus flavus, one of the leading causes of human invasive aspergillosis and a key producer of the most potent naturally occurring hepatocarcinogenic compounds, with FOH to assess its effect on the viability of the fungus. FOH strongly inhibited germination and growth of A. flavus and induced markers for apoptosis including nuclear condensation, phosphatidylserine (PS) externalization, DNA fragmentation and intracellular reactive oxygen species (ROS) generation, metacaspase activation and abnormal cellular ultrastructure. Moreover, FOH-induced apoptosis in A. flavus was inhibited by the broad-spectrum caspase inhibitor Z-VAD-fmk and partially inhibited by the ROS scavenger l-proline, which suggests that FOH induces apoptosis in A. flavus via a mechanism involving metacaspase activation and ROS production.

  5. Ruthenium complexes containing bis-benzimidazole derivatives as a new class of apoptosis inducers.

    PubMed

    Li, Linlin; Wong, Yum-Shing; Chen, Tianfeng; Fan, Cundong; Zheng, Wenjie

    2012-01-28

    A series of ruthenium complexes containing bis-benzimidazole derivatives have been synthesized and identified as able to target mitochondria and induce caspase-dependent apoptosis in cancer cells through superoxide overproduction.

  6. Effect of proteasome inhibition on toxicity and CYP3A23 induction in cultured rat hepatocytes: Comparison with arsenite

    SciTech Connect

    Noreault-Conti, Trisha L.; Jacobs, Judith M.; Trask, Heidi W.; Wrighton, Steven A.; Sinclair, Jacqueline F.; Nichols, Ralph C. . E-mail: ralph.c.nichols@dartmouth.edu

    2006-12-15

    Previous work in our laboratory has shown that acute exposure of primary rat hepatocyte cultures to non-toxic concentrations of arsenite causes major decreases in the DEX-mediated induction of CYP3A23 protein, with minor decreases in CYP3A23 mRNA. To elucidate the mechanism for these effects of arsenite, the effects of arsenite and proteasome inhibition, separately and in combination, on induction of CYP3A23 protein were compared. The proteasome inhibitor, MG132, inhibited proteasome activity, but also decreased CYP3A23 mRNA and protein. Lactacystin, another proteasome inhibitor, decreased CYP3A23 protein without affecting CYP3A23 mRNA at a concentration that effectively inhibited proteasome activity. This result, suggesting that the action of lactacystin is similar to arsenite and was post-transcriptional, was confirmed by the finding that lactacystin decreased association of DEX-induced CYP3A23 mRNA with polyribosomes. Both MG132 and lactacystin inhibited total protein synthesis, but did not affect MTT reduction. Arsenite had no effect on ubiquitination of proteins, nor did arsenite significantly affect proteasomal activity. These results suggest that arsenite and lactacystin act by similar mechanisms to inhibit translation of CYP3A23.

  7. Inhibition of nitric oxide-induced apoptosis by nicotine in oral epithelial cells.

    PubMed

    Banerjee, Abhijit G; Gopalakrishnan, Velliyur K; Vishwanatha, Jamboor K

    2007-11-01

    Development of oral cancer is clearly linked to the usage of smokeless tobacco. The molecular mechanisms involved in this process are however not well understood. Toward this goal, we investigated the effect of smokeless tobacco exposure on apoptosis of oral epithelial cells. Exposure of oral epithelial cells to smokeless tobacco extract (STE) induces apoptosis in a dose-dependent manner, until a threshold level of nicotine is achieved upon which apoptosis is inhibited. 1 mM of nicotine is able to inhibit apoptosis significantly induced by STE in these oral cells. Exposure of cells to nicotine alone has no effect on apoptosis, but nicotine inhibits apoptosis induced by other agents present in STE. In this study we show that, the anti-apoptotic action of nicotine is specifically associated with down-regulation of nitric oxide (NO) production. Using specific inducers of NO, we have demonstrated that inhibition of apoptosis by nicotine is through down-regulation of NO production. Further, we observed that nicotine clearly acts as a sink of NO radicals, shown using peroxynitrite generator (SIN-1) in conjunction or absence of radical scavengers. Nicotine thus causes most damage in transformed epithelial cells as depicted by accumulation of nitrotyrosine in a 3-NT ELISA assay. Inhibition of apoptosis is a hallmark in tumor progression and propels development of cancer. It may further result in functional loss of apoptotic effector mechanisms in the transformed cells. Thus, our data clearly indicates that inhibition of NO-induced apoptosis by nicotine may lead to tobacco-induced oral carcinogenesis, and implies careful development of modalities in tobacco cessation programs.

  8. Selective apoptosis-inducing activity of crinum-type Amaryllidaceae alkaloids.

    PubMed

    McNulty, James; Nair, Jerald J; Codina, Carles; Bastida, Jaume; Pandey, Siyaram; Gerasimoff, Jenny; Griffin, Carly

    2007-04-01

    The selective apoptosis-inducing activity of Amaryllidaceae alkaloids belonging to the crinane-type is reported. A mini-library of natural and synthetic crinane alkaloids was assembled. Biological screening indicated crinamine 4 and haemanthamine 9 to be potent inducers of apoptosis in tumour cells at micromolar concentrations. Structure-activity relationships demonstrated the requirement for both an alpha-C2 bridge and a free hydroxyl at the C-11 position as pharmacophoric requirements for this activity.

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

    SciTech Connect

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

    2014-09-26

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

  10. Gambogic acid induces apoptosis in diffuse large B-cell lymphoma cells via inducing proteasome inhibition.

    PubMed

    Shi, Xianping; Lan, Xiaoying; Chen, Xin; Zhao, Chong; Li, Xiaofen; Liu, Shouting; Huang, Hongbiao; Liu, Ningning; Zang, Dan; Liao, Yuning; Zhang, Peiquan; Wang, Xuejun; Liu, Jinbao

    2015-04-08

    Resistance to chemotherapy is a great challenge to improving the survival of patients with diffuse large B-cell lymphoma (DLBCL), especially those with activated B-cell-like DLBCL (ABC-DLBCL). Therefore it is urgent to search for novel agents for the treatment of DLBCL. Gambogic acid (GA), a small molecule derived from Chinese herb gamboges, has been approved for Phase II clinical trial for cancer therapy by Chinese FDA. In the present study, we investigated the effect of GA on cell survival and apoptosis in DLBCL cells including both GCB- and ABC-DLBCL cells. We found that GA induced growth inhibition and apoptosis of both GCB- and ABC-DLBCL cells in vitro and in vivo, which is associated with proteasome malfunction. These findings provide significant pre-clinical evidence for potential usage of GA in DLBCL therapy particularly in ABC-DLBCL treatment.

  11. A novel role for the apoptosis inhibitor ARC in suppressing TNFα-induced regulated necrosis.

    PubMed

    Kung, G; Dai, P; Deng, L; Kitsis, R N

    2014-04-01

    TNFα signaling can promote apoptosis or a regulated form of necrosis. ARC (apoptosis repressor with CARD (caspase recruitment domain)) is an endogenous inhibitor of apoptosis that antagonizes both the extrinsic (death receptor) and intrinsic (mitochondrial/ER) apoptosis pathways. We discovered that ARC blocks not only apoptosis but also necrosis. TNFα-induced necrosis was abrogated by overexpression of wild-type ARC but not by a CARD mutant that is also defective for inhibition of apoptosis. Conversely, knockdown of ARC exacerbated TNFα-induced necrosis, an effect that was rescued by reconstitution with wild-type, but not CARD-defective, ARC. Similarly, depletion of ARC in vivo exacerbated necrosis caused by infection with vaccinia virus, which elicits severe tissue damage through this pathway, and sensitized mice to TNFα-induced systemic inflammatory response syndrome. The mechanism underlying these effects is an interaction of ARC with TNF receptor 1 that interferes with recruitment of RIP1, a critical mediator of TNFα-induced regulated necrosis. These findings extend the role of ARC from an apoptosis inhibitor to a regulator of the TNFα pathway and an inhibitor of TNFα-mediated regulated necrosis.

  12. Hyperthermia Induces Apoptosis of 786-O Cells through Suppressing Ku80 Expression

    PubMed Central

    Qi, Defeng; Hu, Yuan; Li, Jinhui; Peng, Tao; Su, Jialin; He, Yun; Ji, Weidong

    2015-01-01

    Hyperthermia as an anticancer method has been paid increasing attention in recent years. Several studies have shown that hyperthermia can kill tumor cells by inducing apoptosis. However, the underlying molecular mechanisms of hyperthermia-induced apoptosis are largely unknown. To investigate the effects and molecular mechanism of hyperthermia on the apoptosis in renal carcinoma 786-O cells, we firstly examined apoptosis and Ku expression in 786-O cell line treated with heat exposure (42°C for 0-4 h). The results showed that hyperthermia induced apoptosis of 786-O cells, and suppressed significantly Ku80 expression, but not Ku70 expression. Next, we knock-down Ku80 in 786-O cells, generating stable cell line 786-O-shKu80, and detected apoptosis, cell survival and cell cycle distribution. Our data showed higher apoptotic rate and lower surviving fraction in the stable cell line 786-O-shKu80 compared with those in control cells, exposed to the same heat stress (42°C for 0-4 h). Moreover, the results also showed suppression of Ku80 led to G2/M phase arrest in the stable cell line 786-O-shKu80 following heat treatment. Together, these findings indicate that Ku80 may play an important role in hyperthermia-induced apoptosis and heat-sensitivity of renal carcinoma cells through influencing the cell cycle distribution. PMID:25902193

  13. Acid Sphingomyelinase Mediates Oxidized-LDL Induced Apoptosis in Macrophage via Endoplasmic Reticulum Stress

    PubMed Central

    Zhao, Min; Pan, Wei; Shi, Rui-zheng; Bai, Yong-ping; You, Bo-yang; Zhang, Kai; Fu, Qiong-mei; Schuchman, Edward H.

    2016-01-01

    Aim: Macrophage apoptosis is a vital event in advanced atherosclerosis, and oxidized low-density lipoprotein (ox-LDL) is a major contributor to this process. Acid sphingomyelinase (ASM) and ceramide are also involved in the induction of apoptosis, particularly in macrophages. Our current study focuses on ASM and investigates its role in ox-LDL-induced macrophage apoptosis. Methods: Human THP-1 and mouse peritoneal macrophages were cultured in vitro and treated with ox-LDL. ASM activity and ceramide levels were quantified using ultra performance liquid chromatography. Protein and mRNA levels were analyzed using Western blot analysis and quantitative realtime PCR, respectively. Cell apoptosis was determined using Hoechst staining and flow cytometry. Results: Ox-LDL-induced macrophage apoptosis was triggered by profound endoplasmic reticulum (ER) stress, leading to an upregulation of ASM activity and ceramide levels at an early stage. ASM was inhibited by siRNA or desipramine (DES), and/or ceramide was degraded by recombinant acid ceramidase (AC). These events attenuated the effect of ox-LDL on ER stress. In contrast, recombinant ASM upregulated ceramide and ER stress. ASM siRNA, DES, recombinant AC, and ER stress inhibitor 4-phenylbutyric acid were blocked by elevated levels of C/EBP homologous protein (CHOP); ox-LDL induced elevated levels of CHOP. These events attenuated macrophage apoptosis. Conclusion: These results indicate that ASM/ceramide signaling pathway is involved in ox-LDL-induced macrophage apoptosis via ER stress pathway. PMID:26923251

  14. Nrf2-dependent protection against acute sodium arsenite toxicity in zebrafish.

    PubMed

    Fuse, Yuji; Nguyen, Vu Thanh; Kobayashi, Makoto

    2016-08-15

    Transcription factor Nrf2 induces a number of detoxifying enzymes and antioxidant proteins to confer protection against the toxic effects of a diverse range of chemicals including inorganic arsenicals. Although a number of studies using cultured cells have demonstrated that Nrf2 has a cell-protective function against acute and high-dose arsenic toxicity, there is no clear in vivo evidence of this effect. In the present study, we genetically investigated the protective role of Nrf2 against acute sodium arsenite toxicity using the zebrafish Nrf2 mutant, nrf2a(fh318). After treatment with 1mM sodium arsenite, the survival of nrf2a(fh318) larvae was significantly shorter than that of wild-type siblings, suggesting that Nrf2 protected the zebrafish larvae against high-dose arsenite exposure. To understand the molecular basis of the Nrf2-dependent protection, we analyzed the gene expression profiles after arsenite exposure, and found that the genes involved in the antioxidative function (prdx1 and gclc), arsenic metabolism (gstp1) and xenobiotic elimination (abcc2) were induced in an Nrf2-dependent manner. Furthermore, pre-treatment with sulforaphane, a well-known Nrf2 activator improved the survival of zebrafish larvae after arsenic exposure. Based on these results, we concluded that Nrf2 plays a fundamental and conserved role in protection against acute sodium arsenite toxicity.

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

    PubMed Central

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

    2013-01-01

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

  16. Mechanisms and Consequences of Ebolavirus-Induced Lymphocyte Apoptosis

    DTIC Science & Technology

    2011-01-31

    innate and adaptive immune system to respond to infection (5, 6). However, recent studies have indicated that a functional CD8+ T cell-mediated immune...apoptotic pathway (s) nor the systemic implications of lymphocyte apoptosis in EBOV infection are known. In this study , we show data suggesting that...pathway (s) nor the systemic implications of lymphocyte apoptosis in EBOV infection are known. In this study , we show data suggesting that EBOV

  17. Resveratrol inhibits the hydrogen dioxide-induced apoptosis via Sirt 1 activation in osteoblast cells.

    PubMed

    He, Na; Zhu, Xuewei; He, Wei; Zhao, Shiwei; Zhao, Weiyan; Zhu, Chunlei

    2015-01-01

    Sirt 1 plays a critical role in stress responses. We determined the deregulation of Sirt 1 activity, p53 acetylation, Bcl-2 expression, and mitochondria-dependent apoptosis in mouse osteoblast MC3T3-E1 cells which were exposed to H2O2. And then we investigated the protective role of Sirt 1 activator, Resveratrol (RSV), against the H2O2-induced apoptosis. Results demonstrated that Sirt 1 and Bcl-2 were inhibited, whereas p53 acetylation, Bax, and caspase 9 were promoted by H2O2, as was aggravated by the Sirt 1 inhibitor, EX-527. Instead, RSV inhibited the H2O2-induced both p53 acetylation and the caspase 9 activation, whereas ameliorated the H2O2-induced Bcl-2 inhibition and apoptosis. In conclusion, Sirt 1 was downregulated during the H2O2-induced apoptosis in MC3T3-E1 cells. And the chemical activation of Sirt 1 inhibited the H2O2-induced apoptosis via the downregulation of p53 acetylation. Our results suggest that Sirt 1 upregulation appears to be an important strategy to inhibit the oxidative stress-induced apoptosis.

  18. Different pathways to apoptosis induced by tetraphenylporphine derivatives and light in V79 cells

    NASA Astrophysics Data System (ADS)

    Noodt, Barbara B.; Berg, Kristian; Stokke, Trond; Peng, Qian; Nesland, Jahn M.

    1997-12-01

    Photodynamic therapy (PDT)-induced kinetics of apoptosis were studied in V79 cells using several differently localized photosensitizing dyes, mostly tetraphenylporphine derivatives. Apoptotic fractions were quantified by flow cytometry after staining the samples by the terminal deoxynucleotidyl transferase (TdT)-assay. Methylene blue derivative (MBD), a new dye for PDT, and 5-aminolevulinic acid (ALA)-induced protoporphyrin IX that are both localized in mitochondria, induced apoptosis rapidly within hours after PDT. With MBD it was shown that rapid apoptosis was induced only with dye concentration above a certain threshold. With a lower dye concentration apoptosis was delayed more than one day and was induced due to inhibition of oxidative phosphorylation. After PDT with two membrane localized dyes, tetra(3- hydroxyphenyl)porphyrin (3THPP) and Photofrin, maximal induction of apoptosis took about 12 h. With two lysosomal localized sulfonated meso-tetraphenylporphines (TPPS2a and TPPS4) no apoptosis was induced until more than 12 h after PDT. The results are discussed in relation to evidence in the literature on the nature of possible pathways involved.

  19. Thimerosal induces apoptosis and G2/M phase arrest in human leukemia cells.

    PubMed

    Woo, Kyung Jin; Lee, Tae-Jin; Bae, Jae Hoon; Jang, Byeong-Churl; Song, Dae-Kyu; Cho, Jae-We; Suh, Seong-Il; Park, Jong-Wook; Kwon, Taeg Kyu

    2006-09-01

    Thimerosal is an organomercury compound with sulfhydryl-reactive properties. The ability of thimerosal to act as a sulfhydryl group is related to the presence of mercury. Due to its antibacterial effect, thimerosal is widely used as preservatives and has been reported to cause chemically mediated side effects. In the present study, we showed that the molecular mechanism of thimerosal induced apoptosis in U937 cells. Thimerosal was shown to be responsible for the inhibition of U937 cells growth by inducing apoptosis. Treatment with 2.5-5 microM thimerosal but not thiosalicylic acid (structural analog of thimerosal devoid of mercury) for 12 h produced apoptosis, G(2)/M phase arrest, and DNA fragmentation in a dose-dependent manner. Treatment with caspase inhibitor significantly reduced thimerosal-induced caspase 3 activation. In addition, thimerosal-induced apoptosis was attenuated by antioxidant Mn (III) meso-tetrakis (4-benzoic acid) porphyrin (Mn-TBAP). These data indicate that the cytotoxic effect of thimerosal on U937 cells is attributable to the induced apoptosis and that thimerosal-induced apoptosis is mediated by reactive oxygen species generation and caspase-3 activation.

  20. Role of asymmetric dimethylarginine in homocysteine-induced apoptosis of vascular smooth muscle cells.

    PubMed

    Yuan, Qiong; Jiang, De-Jian; Chen, Qing-Quan; Wang, Shan; Xin, Hong-Ya; Deng, Han-Wu; Li, Yuan-Jian

    2007-05-18

    Homocysteine (Hcy) could induce apoptosis of vascular smooth muscle cells (VSMC). Asymmetric dimethylarginine (ADMA) has been thought as a novel risk factor for cardiovascular diseases. We hypothesized that ADMA mediates homocysteine-induced apoptosis of VSMC. In this experiment the level of ADMA in the medium measured by high-performance liquid chromatography (HPLC) was elevated when the apoptosis of T/G HA-VSMC was induced by Hcy which was detected by Hoechst33342 staining or flow cytometry (FCM) with Annecin V+Propidium Iodide (PI). Exogenous ADMA induced the apoptosis of VSMC. At the same time, ADMA elevated the level of intracellular reactive oxidative species (ROS) determined by fluorescent ROS detection kit. The activation of JNK and p38MAPK contributed to ADMA-induced apoptosis of VSMC. The present results suggest that endogenous ADMA is involved in apoptosis of VSMC induced by Hcy, and the effects of ADMA is related to elevation of intracellular ROS and activation of JNK/p38MAPK signaling pathways.

  1. Cytoprotective role of autophagy during paclitaxel-induced apoptosis in Saos-2 osteosarcoma cells.

    PubMed

    Kim, Hyeon Jun; Lee, Seung Gee; Kim, Yoon-Jae; Park, Ji-Eun; Lee, Kyu Yeol; Yoo, Young Hyun; Kim, Jong-Min

    2013-06-01

    Osteosarcoma (OS) is the most common primary malignant bone cancer in children and adolescents. Although paclitaxel (PCX) has been considered one of the most important cancer chemotherapeutic drugs, the current protocols for OS treatment do not incorporate this agent. Therefore, the purpose of this study was to evaluate the induction of cell death in OS cells after exposure to PCX, to identify the cell death mechanism(s) activated by PCX and to investigate whether autophagy is associated with PCX-induced apoptosis. The results of the present study confirmed that exposure to low PCX concentrations can induce apoptotic cell death in Saos-2 cells; furthermore, caspase-3 activation, PARP degradation and XIAP downregulation were observed in combination with PCX-induced apoptosis. The potential involvement of mitochondrial events (intrinsic apoptotic pathway) in PCX-induced apoptosis in OS cells was verified by the alteration (depolarization) of mitochondrial membrane potential. In addition, pretreatment with 3-methyladenine (3-MA), a specific inhibitor of autophagy, significantly increased PCX-induced apoptotic cell death in Saos-2 cells. The augmentation of PCX-induced apoptosis by 3-MA was accompanied by increase in the cytochrome c release from the mitochondria, caspase-3 activity and XIAP downregulation, which suggests that inhibiting autophagy further stimulates the PCX-induced mitochondrion-related (intrinsic) apoptotic pathway by provoking caspase-3 activation. Thus, autophagy observed during PCX-induced apoptosis in Saos-2 OS cells represents the role of cytoprotection in cellular homeostatic processes. In conclusion, the results of this study revealed that PCX exposure effectively induces OS cell death by apoptosis associated with the mitochondrial-mediated caspase-dependent pathway. PCX can increase autophagic activity and suppressing autophagy enhances PCX-induced apoptosis in OS cells. Therefore, it is suggested that combination treatment involving low

  2. Oncogenic Ras promotes butyrate-induced apoptosis through inhibition of gelsolin expression.

    PubMed

    Klampfer, Lidija; Huang, Jie; Sasazuki, Takehiko; Shirasawa, Senji; Augenlicht, Leonard

    2004-08-27

    Activation of Ras promotes oncogenesis by altering a multiple of cellular processes, such as cell cycle progression, differentiation, and apoptosis. Oncogenic Ras can either promote or inhibit apoptosis, depending on the cell type and the nature of the apoptotic stimuli. The response of normal and transformed colonic epithelial cells to the short chain fatty acid butyrate, a physiological regulator of epithelial cell maturation, is also divergent: normal epithelial cells proliferate, and transformed cells undergo apoptosis in response to butyrate. To investigate the role of k-ras mutations in butyrate-induced apoptosis, we utilized HCT116 cells, which harbor an oncogenic k-ras mutation and two isogenic clones with targeted inactivation of the mutant k-ras allele, Hkh2, and Hke-3. We demonstrated that the targeted deletion of the mutant k-ras allele is sufficient to protect epithelial cells from butyrate-induced apoptosis. Consistent with this, we showed that apigenin, a dietary flavonoid that has been shown to inhibit Ras signaling and to reverse transformation of cancer cell lines, prevented butyrate-induced apoptosis in HCT116 cells. To investigate the mechanism whereby activated k-ras sensitizes colonic cells to butyrate, we performed a genome-wide analysis of Ras target genes in the isogenic cell lines HCT116, Hkh2, and Hke-3. The gene exhibiting the greatest down-regulation by the activating k-ras mutation was gelsolin, an actin-binding protein whose expression is frequently reduced or absent in colorectal cancer cell lines and primary tumors. We demonstrated that silencing of gelsolin expression by small interfering RNA sensitized cells to butyrate-induced apoptosis through amplification of the activation of caspase-9 and caspase-7. These data therefore demonstrate that gelsolin protects cells from butyrate-induced apoptosis and suggest that Ras promotes apoptosis, at least in part, through its ability to down-regulate the expression of gelsolin.

  3. TGEV nucleocapsid protein induces cell cycle arrest and apoptosis through activation of p53 signaling

    SciTech Connect

    Ding, Li; Huang, Yong; Du, Qian; Dong, Feng; Zhao, Xiaomin; Zhang, Wenlong; Xu, Xingang; Tong, Dewen

    2014-03-07

    Highlights: • TGEV N protein reduces cell viability by inducing cell cycle arrest and apoptosis. • TGEV N protein induces cell cycle arrest and apoptosis by regulating p53 signaling. • TGEV N protein plays important roles in TGEV-induced cell cycle arrest and apoptosis. - Abstract: Our previous studies showed that TGEV infection could induce cell cycle arrest and apoptosis via activation of p53 signaling in cultured host cells. However, it is unclear which viral gene causes these effects. In this study, we investigated the effects of TGEV nucleocapsid (N) protein on PK-15 cells. We found that TGEV N protein suppressed cell proliferation by causing cell cycle arrest at the S and G2/M phases and apoptosis. Characterization of various cellular proteins that are involved in regulating cell cycle progression demonstrated that the expression of N gene resulted in an accumulation of p53 and p21, which suppressed cyclin B1, cdc2 and cdk2 expression. Moreover, the expression of TGEV N gene promoted translocation of Bax to mitochondria, which in turn caused the release of cytochrome c, followed by activation of caspase-3, resulting in cell apoptosis in the transfected PK-15 cells following cell cycle arrest. Further studies showed that p53 inhibitor attenuated TGEV N protein induced cell cycle arrest at S and G2/M phases and apoptosis through reversing the expression changes of cdc2, cdk2 and cyclin B1 and the translocation changes of Bax and cytochrome c induced by TGEV N protein. Taken together, these results demonstrated that TGEV N protein might play an important role in TGEV infection-induced p53 activation and cell cycle arrest at the S and G2/M phases and apoptosis occurrence.

  4. Actinobacillus pleuropneumoniae serotype 10 derived ApxI induces apoptosis in porcine alveolar macrophages.

    PubMed

    Chien, Maw-Sheng; Chan, You-Yu; Chen, Zeng-Weng; Wu, Chi-Ming; Liao, Jiunn-Wang; Chen, Ter-Hsin; Lee, Wei-Cheng; Yeh, Kuang-Sheng; Hsuan, Shih-Ling

    2009-03-30

    Actinobacillus pleuropneumoniae (AP) is the causative agent of swine pleuropneumonia, a fibrinous, exudative, hemorrhagic, necrotizing pleuropneumonia affecting all ages of pigs. Actinobacillus pleuropneumoniae exotoxins (Apx) are one of the major virulence factors of AP. Due to the complex nature of Apx toxins produced by AP, little is known regarding the interactions of individual species of Apx toxin with target cells. The objective of this study was to examine whether AP serotype 10-derived exotoxin, ApxI, caused apoptosis in porcine alveolar macrophages (PAMs) and to delineate the underlying signaling pathways. Isolated PAMs were stimulated with different concentrations of native ApxI and monitored for apoptosis using Hoechst staining, TUNEL, and DNA laddering assays. The ApxI-stimulated PAMs exhibited typical morphological features of apoptosis, including condensation of chromatin, formation of apoptotic bodies and DNA laddering. ApxI-induced apoptosis in a concentration- and time-dependent manner. Furthermore, to delineate the signaling events involved in ApxI-induced apoptosis, it was observed that caspase 3 was activated in ApxI-stimulated PAMs. Ablation of caspase 3 activity via specific inhibitors protected PAMs from apoptosis by ApxI. This study is the first to demonstrate that native ApxI causes apoptosis in PAMs at low concentrations and that these apoptotic events are mediated via a caspase 3-dependent pathway. These findings suggest a role of ApxI in AP infection as it might impair the host defense system through the induction of apoptosis in PAMs.

  5. Protective effect of silymarin on viability, motility and mitochondrial membrane potential of ram sperm treated with sodium arsenite

    PubMed Central

    Eskandari, Farzaneh; Momeni, Hamid Reza

    2016-01-01

    Background: Sodium arsenite can impair male reproductive function by inducing oxidative stress. Silymarin is known as a potent antioxidant. Objective: This study was performed to investigate if silymarin can prevent the adverse effect of sodium arsenite on ram sperm viability, motility and mitochondrial membrane potential. Materials and Methods: Epidydimal spermatozoa obtained from ram were divided into five groups: 1) Spermatozoa at 0 hr, 2) spermatozoa at 180 min (control), 3) spermatozoa treated with sodium arsenite (10 μM) for 180 min, 4) spermatozoa treated with silymarin (20 μM) + sodium arsenite (10 μM) for 180 min and 5) spermatozoa treated with silymarin (20 μM) for 180 min. MTT assay and Rhodamine 123 staining were used to assess sperm viability and mitochondrial membrane potential respectively. Sperm motility was performed according to World Health Organization (WHO) guidelines. Results: Viability (p<0.01), nonprogressive motility (p<0.001) and intact mitochondrial membrane potential (p<0.001) of the spermatozoa were significantly decreased in sodium arsenite treated group compared to control group. In silymarin + sodium arsenite group, silymarin could significantly reverse the adverse effect of sodium arsenite on these sperm parameters compared to sodium arsenite group (p<0.001). In addition, the application of silymarin alone for 180 minutes could significantly increase progressively motile sperm (p<0.001) and decrease non motile sperm (p<0.01) compared to the control. Conclusion: Silymarin could compensate the adverse effect of sodium arsenite on viability, nonprogressive motility and mitochondrial membrane potential of ram sperm. PMID:27525323

  6. Arsenite evokes IL-6 secretion, autocrine regulation of STAT3 signaling, and miR-21 expression, processes involved in the EMT and malignant transformation of human bronchial epithelial cells

    SciTech Connect

    Luo, Fei; Xu, Yuan; Ling, Min; Zhao, Yue; Xu, Wenchao; Liang, Xiao; Jiang, Rongrong; Wang, Bairu; Bian, Qian; Liu, Qizhan

    2013-11-15

    Arsenite is an established human carcinogen, and arsenite-induced inflammation contributes to malignant transformation of cells, but the molecular mechanisms by which cancers are produced remain to be established. The present results showed that, evoked by arsenite, secretion of interleukin-6 (IL-6), a pro-inflammatory cytokine, led to the activation of STAT3, a transcription activator, and to increased levels of a microRNA, miR-21. Blocking IL-6 with anti-IL-6 antibody and inhibiting STAT3 activation reduced miR-21 expression. For human bronchial epithelial cells, cultured in the presence of anti-IL-6 antibody for 3 days, the arsenite-induced EMT and malignant transformation were reversed. Thus, IL-6, acting on STAT3 signaling, which up-regulates miR-21in an autocrine manner, contributes to the EMT induced by arsenite. These data define a link from inflammation to EMT in the arsenite-induced malignant transformation of HBE cells. This link, mediated through miRNAs, establishes a mechanism for arsenite-induced lung carcinogenesis. - Highlights: • Arsenite evokes IL-6 secretion. • IL-6 autocrine mediates STAT3 signaling and up-regulates miR-21expression. • Inflammation is involved in arsenite-induced EMT.

  7. A radiation-induced acute apoptosis involving TP53 and BAX precedes the delayed apoptosis and neoplastic transformation of CGL1 human hybrid cells.

    PubMed

    Mendonca, Marc S; Mayhugh, Brendan M; McDowell, Berry; Chin-Sinex, Helen; Smith, Martin L; Dynlacht, Joseph R; Spandau, Dan F; Lewis, Davina A

    2005-06-01

    Exposing CGL1 (HeLa x fibroblast) hybrid cells to 7 Gy of X rays results in the onset of a delayed apoptosis in the progeny of the cells 10 to 12 cell divisions postirradiation that correlates with the emergence of neoplastically transformed foci. The delayed apoptosis begins around day 8 postirradiation and lasts for 11 days. We now demonstrate that the delayed apoptosis is also characterized by the appearance of approximately 50-kb apoptotic DNA fragments and caspase 3 activation postirradiation. In addition, we confirm that stabilization of TP53 and transactivation of pro-apoptosis BAX also occurs during the delayed apoptosis and show that anti-apoptosis BCL-X(L) is down-regulated. To test whether the delayed apoptosis was due to a nonfunctional acute TP53 damage response in CGL1 cells, studies of acute apoptosis were completed. After irradiation, CGL1 cells underwent an acute wave of apoptosis that involves TP53 stabilization, transactivation of BAX gene expression, and a rapid caspase activation that ends by 96 h postirradiation. In addition, the acute onset of apoptosis correlates with transactivation of a standard wild-type TP53-responsive reporter (pG13-CAT) in CGL1 cells after radiation exposure. We propose that the onset of the delayed apoptosis is not the result of a nonfunctional acute TP53 damage response pathway but rather is a consequence of X-ray-induced genomic instability arising in the distant progeny of the irradiated cells.

  8. Wogonin, a plant flavone, potentiates etoposide-induced apoptosis in cancer cells.

    PubMed

    Lee, Eibai; Enomoto, Riyo; Suzuki, Chie; Ohno, Masataka; Ohashi, Toshinori; Miyauchi, Azusa; Tanimoto, Eriko; Maeda, Kaori; Hirano, Hiroyuki; Yokoi, Toshio; Sugahara, Chiyoko

    2007-01-01

    Etoposide, a podophylotoxin anticancer agent, induces apoptotic cell death in normal and cancer cells. Etoposide-induced apoptosis plays a role in not only anticancer effect but also adverse reaction, such as myelosuppression. Since we have found that wogonin, a flavone found in Scutellaria baicalensis Georgi, prevents thymocyte apoptosis induced by various compounds including etoposide, we examined the effect of this flavone on etoposide-induced apoptosis in cancer cells. Although 100 muM wogonin itself significantly increased DNA fragmentation in HL-60 cells, this change was not observed in Jurkat cells. On the other hand, this flavone significantly potentiated etoposide-induced apoptosis in Jurkat and HL-60 cells. Similarly, wogonin accelerated etoposide-induced cell death in lung cancer cells. Since wogonin had no effect on the action of other anticancer agents, such as 5-FU and cisplatin, this flavone seems to accelerate only etoposide-induced apoptotic cell death in cancer cells. These results suggest that the modification of etoposide-induced apoptosis by wogonin may be available to reduce the adverse reaction of this agent.

  9. Effects of ceramide inhibition on radiation-induced apoptosis in human leukemia MOLT-4 cells.

    PubMed

    Takahashi, Eriko; Inanami, Osamu; Asanuma, Taketoshi; Kuwabara, Mikinori

    2006-03-01

    In the present study, using inhibitors of ceramide synthase (fumonisin B1), ketosphinganine synthetase (L-cycloserine), acid sphingomyelinase (D609 and desipramine) and neutral sphingomyelinase (GW4869), the role of ceramide in X-ray-induced apoptosis was investigated in MOLT-4 cells. The diacylglycerol kinase (DGK) assay showed that the intracellular concentration of ceramide increased time-dependently after X irradiation of cells, and this radiation-induced accumulation of ceramide did not occur prior to the appearance of apoptotic cells. Treatment with D609 significantly inhibited radiation-induced apoptosis, but did not inhibit the increase of intracellular ceramide. Treatment with desipramine or GW4869 prevented neither radiation-induced apoptosis nor the induced increase of ceramide. On the other hand, fumonisin B1 and L-cycloserine had no effect on the radiation-induced induction of apoptosis, in spite of significant inhibition of the radiation-induced ceramide. From these results, it was suggested that the increase of the intracellular concentration of ceramide was not essential for radiation-induced apoptosis in MOLT-4 cells.

  10. Autophagy may protect MC3T3-E1 cells from fluoride-induced apoptosis.

    PubMed

    Wei, Min; Duan, Dongmei; Liu, Yujie; Wang, Zhigang; Li, Zhongli

    2014-06-01

    Fluoride is an essential trace element for all mammalian species; however, excess fluoride intake is known to be toxic to cells in animals and humans. The toxicity of fluoride is mainly exerted via induction of apoptosis. Autophagy is induced by numerous cytotoxic stimuli; however, it is often unclear whether, under specific conditions, autophagy has a pro‑survival or a pro‑apoptotic role. To answer this critical question, the present study assessed autophagy and apoptosis simultaneously in single cells. It was demonstrated that fluoride was able to inhibit cell proliferation and induce apoptosis and autophagy, whereas autophagy appeared to be protective. Further analysis revealed that MAPK/JNK‑dependent autophagy may be protective in fluoride‑induced apoptosis. It is anticipated that the presented single‑cell approach may be a powerful tool for gaining a quantitative understanding of the complex regulation of autophagy, its effect on cell fate and its association with other cellular pathways.

  11. Inhibition of autophagy ameliorates atherogenic inflammation by augmenting apigenin-induced macrophage apoptosis.

    PubMed

    Wang, Qun; Zeng, Ping; Liu, Yuanliang; Wen, Ge; Fu, Xiuqiong; Sun, Xuegang

    2015-07-01

    Increasing evidences showed that the survival of macrophages promotes atherogenesis. Macrophage apoptosis in the early phase of atherosclerotic process negatively regulates the progression of atherosclerotic lesions. We demonstrated that a natural anti-oxidant apigenin could ameliorate atherogenesis in ApoE(-/-) mice. It reduced the number of foam cells and decreased the serum levels of tumor necrosis factor α, interleukin 1β (IL-1β) and IL-6. Our results showed that oxidized low-density lipoprotein (oxLDL) led to the secretion of pro-inflammatory cytokines. Apigenin-induced apoptosis and downregulated the secretion of TNF-α, IL-6 and IL-1β. It is further supported by the use of zVAD, a pan-caspase inhibitor, demonstrating that apigenin lowered cytokine profile through induction of macrophage apoptosis. Moreover, apigenin-induced Atg5/Atg7-dependent autophagy in macrophages pretreated with oxLDL. Results illustrated that autophagy inhibition increased apigenin-induced apoptosis through activation of Bax. The present findings suggest that oxLDL maintained the survival of macrophages and activated the secretion of pro-inflammatory cytokines to initiate atherosclerosis. Apigenin-induced apoptosis of lipid-laden macrophages and resolved inflammation to ameliorate atherosclerosis. In conclusion, combination of apigenin with autophagy inhibition may be a promising strategy to induce foam cell apoptosis and subdue atherogenic cytokines.

  12. Corosolic acid inhibits the proliferation of osteosarcoma cells by inducing apoptosis

    PubMed Central

    Jia, Yong; Yuan, Hua; Shan, Shouqin; Xu, Gang; Yu, Jie; Zhao, Chenguang; Mou, Xiang

    2016-01-01

    Corosolic acid (CRA), a pentacyclic triterpene isolated from medicinal herbs, has been reported to exhibit anticancer properties in several cancers. However, the anticancer activity of CRA in osteosarcoma cells is still unclear. In the present study, the inhibitory effect of CRA in osteosarcoma MG-63 cells was investigated, and the results revealed that CRA significantly inhibited the viability of MG-63 cells in a dose- and time-dependent manner. A typical apoptotic hallmark such as DNA ladder was detected by agarose gel electrophoresis following treatment with CRA. Further experiments demonstrated that CRA induced apoptosis of MG-63 cells by flow cytometry using propidium iodide and annexin V staining. In addition, it was observed that the apoptosis of MG-63 cells induced by CRA was closely associated with activation of caspase-3 and caspase-9, loss of mitochondrial membrane potential, and release of cytochrome c from mitochondria, suggesting that CRA may trigger the activation of the mitochondria-mediated apoptosis pathway. In addition, the inhibition of caspase activity attenuated the CRA-induced apoptosis of MG-63 cells, which further confirmed the role of the mitochondrial pathway in CRA-induced apoptosis. These results indicated that CRA could induce the apoptosis of osteosarcoma cells through activating the mitochondrial pathway, which provides an evidence that CRA may be a useful chemotherapeutic agent for osteosarcoma. PMID:27895790

  13. Galangin induces apoptosis in hepatocellular carcinoma cells through the caspase 8/t-Bid mitochondrial pathway.

    PubMed

    Zhang, Hai-Tao; Wu, Jun; Wen, Min; Su, Li-Juan; Luo, Hui

    2012-01-01

    This study has investigated whether galangin, a flavonol derived from Alpinia officinarum Hance and used as food additives in southern China, induces apoptosis in hepatocellular carcinoma cells (HCCs) by activation of the caspase-8 and Bid pathway. The apoptosis of HCCs was evaluated by in situ uptake of propidium iodide and Hoechst 33258. Protein expressions were detected by Western blotting. Caspase-8 activity was measured using colorimetric method. To confirm the galangin-induced apoptotic pathway, inhibition of caspase-8 activity by Z-IETD-FMK, knockdown of Bid expression with siRNA, and overexpression of Bcl-2 in cells were carried out, respectively. The results show that galangin has significantly induced apoptosis in HCC lines. The caspase-8 is activated, and the cleavage of Bid results in the increase in tBid. The galangin-induced apoptosis is attenuated by Z-IETD-FMK, Bid siRNA, and Bcl-2 overexpression, respectively. However, Bcl-2 fails to suppress caspase-8 activation and the cleavage of Bid. This study has demonstrated that galangin induces apoptosis in HCCs by activating caspase 8/t-Bid mitochondrial pathway. Although Bcl-2 overexpression attenuates galangin-mediated apoptosis of HCCs, it is not mediated by the inhibition of tBid generation and caspase-8 activation.

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

    PubMed

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

    2000-07-01

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

  15. Compound K induces apoptosis via CAMK-IV/AMPK pathways in HT-29 colon cancer cells.

    PubMed

    Kim, Do Yeon; Park, Min Woo; Yuan, Hai Dan; Lee, Hyo Jung; Kim, Sung Hoon; Chung, Sung Hyun

    2009-11-25

    Although compound K (CK), an intestinal metabolite of ginseng protopanaxadiol saponins, has been known to induce apoptosis in various cancer cells, association of AMP-activated protein kinase (AMPK) with apoptosis in HT-29 colon cancer cells remains unclear. We hypothesized that CK may exert an anticancer activity through modulating the AMPK pathway in HT-29 cells. CK-induced apoptosis was associated with the disruption of the mitochondrial membrane potential, release of apoptogenic factors (cytochrome c and apoptosis-inducing factor) from mitochondria, and cleavage of caspase-9, caspase-3, caspase-8, Bid, and PARP proteins. This apoptotic effect of CK on colon cancer cells was found to be initiated by AMPK activation, and AMPK was activated through phosphorylation by Ca2+/calmodulin-activated protein kinase-IV (CAMK-IV). Treatment of HT-29 cells with compound C (AMPK inhibitor) or siRNA for AMPK completely abolished the CK-induced apoptosis. STO-609, CAMKs inhibitor, also attenuated CK-induced AMPK activation and apoptosis. In conclusion, the present study demonstrates that CK-mediated cell death of HT-29 colon cancer cells is regulated by CAMK-IV/AMPK pathways, and these findings provide a molecular basis for the anticancer effect of CK.

  16. The equine arteritis virus induces apoptosis via caspase-8 and mitochondria-dependent caspase-9 activation.

    PubMed

    St-Louis, Marie-Claude; Archambault, Denis

    2007-10-10

    We have previously showed that equine arteritis virus (EAV), an arterivirus, induces apoptosis in vitro. To determine the caspase activation pathways involved in EAV-induced apoptosis, target cells were treated with peptide inhibitors of apoptosis Z-VAD-FMK (pan-caspase inhibitor), Z-IETD-FMK (caspase-8-specific inhibitor) or Z-LEHD-FMK (caspase-9-specific inhibitor) 4 h prior to infection with the EAV T1329 Canadian isolate. Significant inhibition of apoptosis was obtained with all peptide inhibitors used. Furthermore, apoptosis was inhibited in cells expressing the R1 subunit of herpes simplex virus type 2 ribonucleotide reductase (HSV2-R1) or hsp70, two proteins which are known to inhibit apoptosis associated with caspase-8 activation and cytochrome c release-dependent caspase-9 activation, respectively. Given the activation of Bid and the translocation of cytochrome c within the cytoplasm, the overall results indicate that EAV induces apoptosis initiated by caspase-8 activation and subsequent mitochondria-dependent caspase-9 activation.

  17. Deoxynivalenol induces apoptosis in PC12 cells via the mitochondrial pathway.

    PubMed

    Wang, Xichun; Xu, Wei; Fan, Mengxue; Meng, Tingting; Chen, Xiaofang; Jiang, Yunjing; Zhu, Dianfeng; Hu, Wenjuan; Gong, Jiajie; Feng, Shibin; Wu, Jinjie; Li, Yu

    2016-04-01

    Deoxynivalenol (DON) has broad toxicity in animals and humans. In this study the impact of DON treatment on apoptotic pathways in PC12 cells was determined. The effects of DON were evaluated on (i) typical indicators of apoptosis, including cellular morphology, cell activity, lactate dehydrogenase (LDH) release, and apoptosis ratio in PC12 cells, and on (ii) the expression of key genes and proteins related to apoptosis, including Bcl-2, Bax, Bid, cytochrome C (Cyt C), apoptosis inducing factor (AIF), cleaved-Caspase9, and cleaved-Caspase3. DON treatment inhibited proliferation of PC12 cells, induced significant morphological changes and apoptosis, promoted the release of Cyt C and AIF from the mitochondria, and increased the activities of cleaved-Caspase9 and cleaved-Caspase3. Bcl-2 expression decreased with increasing DON concentrations, in contrast to Bax and Bid, which were increased with increasing DON concentration. These data demonstrate that DON induces apoptosis in PC12 cells through the mitochondrial apoptosis pathway.

  18. Inhibition of NF-kappaB/Rel induces apoptosis of murine B cells.

    PubMed Central

    Wu, M; Lee, H; Bellas, R E; Schauer, S L; Arsura, M; Katz, D; FitzGerald, M J; Rothstein, T L; Sherr, D H; Sonenshein, G E

    1996-01-01

    Apoptosis of the WEHI 231 immature B cell lymphoma line following membrane interaction with an antibody against the surface IgM chains (anti-IgM) is preceded by dramatic changes in Nuclear Factor-kappaB (NF-kappaB)/ Rel binding activities. An early transient increase in NF-kappaB/Rel binding is followed by a significant decrease in intensity below basal levels. Here we have explored the role of these changes in Rel-related factors in B cell apoptosis. Treatment of WEH1 231 cells with N-tosyl-L-phenylalanine chloromethyl ketone (TPCK), a protease inhibitor which prevents degradation of the inhibitor of NF-kappaB (IkappaB)-alpha, or with low doses of pyrrolidinedithiocarbamate (PDTC) selectively inhibited NF-kappaB/Rel factor binding and induced apoptosis. Bcl-XL expression protected WEHI 231 cells from apoptosis induced by these agents. Microinjection of WEHI 231 cells with either IkappaB-alpha-GST protein or a c-Rel affinity-purified antibody induced apoptosis. Ectopic c-Rel expression ablated apoptosis induced by TPCK or anti-IgM. Treatment of BALENLM 17 and A20 B lymphoma cells or normal murine splenic B lymphocytes with either TPCK or PDTC also resulted in apoptosis. These findings indicate that the drop in NF-kappaB/Rel binding following anti-IgM treatment activates apoptosis of WEHI 231 cells; furthermore, they implicate the NF-kappaB/Rel family in control of apoptosis of normal and transformed B cells. Images PMID:8887559

  19. Steroid receptor coactivator-interacting protein (SIP) inhibits caspase-independent apoptosis by preventing apoptosis-inducing factor (AIF) from being released from mitochondria.

    PubMed

    Wang, Dandan; Liang, Jing; Zhang, Yu; Gui, Bin; Wang, Feng; Yi, Xia; Sun, Luyang; Yao, Zhi; Shang, Yongfeng

    2012-04-13

    Apoptosis-inducing factor (AIF) is a caspase-independent death effector. Normally residing in the mitochondrial intermembrane space, AIF is released and translocated to the nucleus in response to proapoptotic stimuli. Nuclear AIF binds to DNA and induces chromatin condensation and DNA fragmentation, characteristics of apoptosis. Until now, it remained to be clarified how the mitochondrial-nuclear translocation of AIF is regulated. Here we report that steroid receptor coactivator-interacting protein (SIP) interacts directly with AIF in mitochondria and specifically inhibits caspase-independent and AIF-dependent apoptosis. Challenging cells with apoptotic stimuli leads to rapid degradation of SIP, and subsequently AIF is liberated from mitochondria and translocated to the nucleus to induce apoptosis. Together, our data demonstrate that SIP is a novel regulator in caspase-independent and AIF-mediated apoptosis.

  20. Elastase induced lung epithelial cell apoptosis and emphysema through placenta growth factor

    PubMed Central

    Hou, H-H; Cheng, S-L; Liu, H-T; Yang, F-Z; Wang, H-C; Yu, C-J

    2013-01-01

    Chronic pulmonary obstructive disease (COPD) is the fourth leading cause of death worldwide, however, the pathogenic factors and mechanisms are not fully understood. Pulmonary emphysema is one of the major components of COPD and is thought to result from oxidative stress, chronic inflammation, protease–antiprotease imbalance and lung epithelial (LE) cell apoptosis. In our previous studies, COPD patients were noted to have higher levels of placenta growth factor (PlGF) in serum and bronchoalveolar lavage fluid than controls. In addition, transgenic mice overexpressing PlGF developed pulmonary emphysema and exposure to PlGF in LE cells induced apoptosis. Furthermore, intratracheal instillation of porcine pancreatic elastase (PPE) on to PlGF wild type mice induced emphysema, but not in PlGF knockout mice. Therefore, we hypothesized that PPE generates pulmonary emphysema through the upregulation of PlGF expression in LE cells. The elevation of PlGF then leads to LE cell apoptosis. In the present study, we investigated whether PPE induces PlGF expression, whether PlGF induces apoptosis and whether the downstream mechanisms of PlGF are related to LE cell apoptosis. We found that PPE increased PlGF secretion and expression both in vivo and in vitro. Moreover, PlGF-induced LE cell apoptosis and PPE-induced emphysema in the mice were mediated by c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (p38 MAPK) pathways. Given these findings, we suggest that the increase in PlGF and PlGF-induced JNK and p38 MAPK pathways contribute to PPE-induced LE cell apoptosis and emphysema. Regulatory control of PlGF and agents against its downstream signals may be potential therapeutic targets for COPD. PMID:24008737

  1. Curcumin induces apoptosis and protective autophagy in castration-resistant prostate cancer cells through iron chelation

    PubMed Central

    Yang, Chunguang; Ma, Xueyou; Wang, Zhihua; Zeng, Xing; Hu, Zhiquan; Ye, Zhangqun; Shen, Guanxin

    2017-01-01

    Background Curcumin induces apoptosis and autophagy in different cancer cells. Moreover, chemical and biological experiments have evidenced that curcumin is a biologically active iron chelator and induces cytotoxicity through iron chelation. We thus hypothesized that curcumin may induce apoptosis and autophagy in castration-resistant prostate cancer (CRPC) cells through its iron-chelating properties. Materials and methods CRPC cells were loaded with curcumin alone or in combination with ferric ammonium citrate (FAC). Cytotoxicity was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Apoptosis was assessed by flow cytometry, terminal deoxynucleotidyl transferase nick end labeling (TUNEL) assay and caspase activity. Autophagy status was analyzed by the detection of autophagosomes and light chain 3-II (LC3-II) using transmission electron microscopy and Western blot. Iron-binding activity of curcumin was assessed by spectrophotometry and MTT assay. The expression levels of transferrin receptor 1 (TfR1) and iron regulatory protein 1 (IRP1) were examined by Western blot. Results Curcumin induced apoptosis and autophagy in CRPC cells. Combining curcumin with autophagy inhibitors (3-methyladenine [3-MA]) synergized the apoptotic effect of curcumin. Moreover, curcumin bound to FAC at a ratio of ~1:1, as assessed by spectrophotometry and MTT assay. Apoptosis and autophagy induced by curcumin were counteracted by equal amounts of FAC. At apoptosis- and autophagy-inducing concentrations, curcumin enhanced the expression levels of TfR1 and IRP1, indicative of iron deprivation induced by curcumin. Conclusion Together, our results indicate that curcumin induces apoptosis and protective autophagy in CRPC cells, which are at least partially dependent on its iron-chelating properties. PMID:28243065

  2. Essential role for cathepsin D in bleomycin-induced apoptosis of alveolar epithelial cells.

    PubMed

    Li, Xiaopeng; Rayford, Heather; Shu, Ruijie; Zhuang, Jiaju; Uhal, Bruce D

    2004-07-01

    Our earlier studies showed that bleomycin-induced apoptosis of type II alveolar epithelial cells (AECs) requires the autocrine synthesis and proteolytic processing of angiotensinogen into ANG II and that inhibitors of ANG-converting enzyme (ACEis) block bleomycin-induced apoptosis (Li X, Zhang H, Soledad-Conrad V, Zhuang J, and Uhal BD. Am J Physiol Lung Cell Mol Physiol 284: L501-L507, 2003). Given the documented role of cathepsin D (CatD) in apoptosis of other cell types, we hypothesized that CatD might be the AEC enzyme responsible for the conversion of angiotensinogen into ANG I, the substrate for ACE. Primary cultures of rat type II AECs challenged with bleomycin in vitro showed upregulation and secretion of CatD enzymatic activity and immunoreactive protein but no increases in CatD mRNA. The aspartyl protease inhibitor pepstatin A, which completely blocked CatD enzymatic activity, inhibited bleomycin-induced nuclear fragmentation by 76% and reduced bleomycin-induced caspase-3 activation by 47%. Antisense oligonucleotides against CatD mRNA reduced CatD-immunoreactive protein and inhibited bleomycin-induced nuclear fragmentation by 48%. A purified fragment of angiotensinogen (F1-14) containing the CatD and ACE cleavage sites, when applied to unchallenged AEC in vitro, yielded mature ANG II peptide and induced apoptosis. The apoptosis induced by F1-14 was inhibited 96% by pepstatin A and 77% by neutralizing antibodies specific for CatD (both P < 0.001). These data indicate a critical role for CatD in bleomycin-induced apoptosis of cultured AEC and suggest that the role(s) of CatD in AEC apoptosis include the conversion of newly synthesized angiotensinogen to ANG II.

  3. Responses to heat shock, arsenite and cadmium in soybean

    SciTech Connect

    Edelman, L. ); Key, J.L. )

    1989-04-01

    Heat shock (HS), arsenite (As) and cadmium (Cd) treatments induced the HS response in soybean seedlings but differed in their abilities to induce stress tolerance. Pretreatment of seedlings with sub-lethal HS protected them from subsequent normally lethal HS treatment. However, the protection was much more pronounced in 1 day-old than in 2 day-old plants. Sublethal arsenite pretreatment resulted in only a low level of protection against lethal As or HS treatment and severe damage still occurred in specific tissues. Cadmium did not induce any self- or cross-protection. DNA sequence analyses revealed that HS, As and Cd induced the transcription of similar sequences. However, Northern blot analyses of HS mRNAs, and analyses of in vitro translation products and in vivo-labeled proteins by 1D and 2D SDS-PAGE demonstrated that, compared to HS, the response to the chemical stresses was slower, less intense and not as selective. Apparently any causal relationship between HS proteins and induced stress tolerance must also involve developmental-, tissue-, and/or quantitative-specificities.

  4. p53 modulates the AMPK inhibitor compound C induced apoptosis in human skin cancer cells

    SciTech Connect

    Huang, Shi-Wei; Wu, Chun-Ying; Wang, Yen-Ting; Kao, Jun-Kai; Lin, Chi-Chen; Chang, Chia-Che; Mu, Szu-Wei; Chen, Yu-Yu; Chiu, Husan-Wen; Chang, Chuan-Hsun; Liang, Shu-Mei; Chen, Yi-Ju; Huang, Jau-Ling; Shieh, Jeng-Jer

    2013-02-15

    Compound C, a well-known inhibitor of the intracellular energy sensor AMP-activated protein kinase (AMPK), has been reported to cause apoptotic cell death in myeloma, breast cancer cells and glioma cells. In this study, we have demonstrated that compound C not only induced autophagy in all tested skin cancer cell lines but also caused more apoptosis in p53 wildtype skin cancer cells than in p53-mutant skin cancer cells. Compound C can induce upregulation, phosphorylation and nuclear translocalization of the p53 protein and upregulate expression of p53 target genes in wildtype p53-expressing skin basal cell carcinoma (BCC) cells. The changes of p53 status were dependent on DNA damage which was caused by compound C induced reactive oxygen species (ROS) generation and associated with activated ataxia-telangiectasia mutated (ATM) protein. Using the wildtype p53-expressing BCC cells versus stable p53-knockdown BCC sublines, we present evidence that p53-knockdown cancer cells were much less sensitive to compound C treatment with significant G2/M cell cycle arrest and attenuated the compound C-induced apoptosis but not autophagy. The compound C induced G2/M arrest in p53-knockdown BCC cells was associated with the sustained inactive Tyr15 phosphor-Cdc2 expression. Overall, our results established that compound C-induced apoptosis in skin cancer cells was dependent on the cell's p53 status. - Highlights: ► Compound C caused more apoptosis in p53 wildtype than p53-mutant skin cancer cells. ► Compound C can upregulate p53 expression and induce p53 activation. ► Compound C induced p53 effects were dependent on ROS induced DNA damage pathway. ► p53-knockdown attenuated compound C-induced apoptosis but not autophagy. ► Compound C-induced apoptosis in skin cancer cells was dependent on p53 status.

  5. C-phycocyanin ameliorates doxorubicin-induced oxidative stress and apoptosis in adult rat cardiomyocytes.

    PubMed

    Khan, Mahmood; Varadharaj, Saradhadevi; Shobha, Jagdish C; Naidu, Madireddi U; Parinandi, Narasimham L; Kutala, Vijay Kumar; Kuppusamy, Periannan

    2006-01-01

    Doxorubicin (DOX), a potent antineoplastic agent, poses limitations for its therapeutic use due to the associated risk of developing cardiomyopathy and congestive heart failure. The cardiotoxicity of doxorubicin is associated with oxidative stress and apoptosis. We have recently shown that Spirulina, a blue-green alga with potent antioxidant properties, offered significant protection against doxorubicin-induced cardiotoxicity in mice. The aim of the present study was to establish the possible protective role of C-phycocyanin, one of the active ingredients of Spirulina, against doxorubicin-induced oxidative stress and apoptosis. The study was carried out using cardiomyocytes isolated from adult rat hearts. Doxorubicin significantly enhanced the formation of reactive oxygen species (ROS) in cells as measured by the 2',7'-dichlorodihydrofluorescein diacetate and dihydroethidium fluorescence. The doxorubicin-induced reactive oxygen species formation was significantly attenuated in cells pretreated with C-phycocyanin. It was further observed that the doxorubicin-induced DNA fragmentation and apoptosis, as assayed by TUNEL assay and flow cytometry coupled with BrdU-FITC/propidium iodide staining, were markedly attenuated by C-phycocyanin. C-phycocyanin also significantly attenuated the doxorubicin-induced increase in the expression of Bax protein, release of cytochrome c, and increase in the activity of caspase-3 in cells. In summary, C-phycocyanin ameliorated doxorubicin-induced oxidative stress and apoptosis in cardiomyocytes. This study further supports the crucial role of the antioxidant nature of C-phycocyanin in its cardioprotection against doxorubicin-induced oxidative stress and apoptosis.

  6. Metformin enhances TRAIL-induced apoptosis by Mcl-1 degradation via Mule in colorectal cancer cells

    PubMed Central

    Kim, Jung Lim; Kim, Bo Ram; Na, Yoo Jin; Jo, Min Jee; Jeong, Yoon A.; Lee, Suk-Young; Lee, Sun Il; Lee, Yong Yook; Oh, Sang Cheul

    2016-01-01

    Metformin is an anti-diabetic drug with a promising anti-cancer potential. In this study, we show that subtoxic doses of metformin effectively sensitize human colorectal cancer (CRC) cells to tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), which induces apoptosis. Metformin alone did not induce apoptosis, but significantly potentiated TRAIL-induced apoptosis in CRC cells. CRC cells treated with metformin and TRAIL showed activation of the intrinsic and extrinsic pathways of caspase activation. We attempted to elucidate the underlying mechanism, and found that metformin significantly reduced the protein levels of myeloid cell leukemia 1 (Mcl-1) in CRC cells and, the overexpression of Mcl-1 inhibited cell death induced by metformin and/or TRAIL. Further experiments revealed that metformin did not affect mRNA levels, but increased proteasomal degradation and protein stability of Mcl-1. Knockdown of Mule triggered a significant decrease of Mcl-1 polyubiquitination. Metformin caused the dissociation of Noxa from Mcl-1, which allowed the binding of the BH3-containing ubiquitin ligase Mule followed by Mcl-1ubiquitination and degradation. The metformin-induced degradation of Mcl-1 required E3 ligase Mule, which is responsible for the polyubiquitination of Mcl-1. Our study is the first report indicating that metformin enhances TRAIL-induced apoptosis through Noxa and favors the interaction between Mcl-1 and Mule, which consequently affects Mcl-1 ubiquitination. PMID:27517746

  7. Hispidulin induces mitochondrial apoptosis in acute myeloid leukemia cells by targeting extracellular matrix metalloproteinase inducer

    PubMed Central

    Gao, Hui; Liu, Yongji; Li, Kan; Wu, Tianhui; Peng, Jianjun; Jing, Fanbo

    2016-01-01

    Acute myeloid leukemia (AML) represents a heterogeneous group of hematological neoplasms with marked heterogeneity in response to both standard therapy and survival. Hispidulin, a flavonoid compound that is anactive ingredient in the traditional Chinese medicinal herb Salvia plebeia R. Br, has recently been reported to have anantitumor effect against solid tumors in vitro and in vivo. The aim of the present study was to investigate the effects of hispidulin on the human leukemia cell line in vitro and the underlying mechanisms of its actions on these cells. Our results showed that hispidulin inhibits AML cell proliferation in a dose- and time-dependent manner, and induces cell apoptosis throughan intrinsic mitochondrial pathway. Our results also revealed that hispidulin treatment significantly inhibits extracellular matrix metalloproteinase inducer (EMMPRIN) expression in both tested AML cell lines in a dose-dependent manner, and that the overexpression of EMMPRIN protein markedly attenuates hispidulin-induced cell apoptosis. Furthermore, our results strongly indicated that the modulating effect of hispidulin on EMMPRIN is correlated with its inhibitory effect on both the Akt and STAT3 signaling pathways. PMID:27158398

  8. A novel firefly luciferase biosensor enhances the detection of apoptosis induced by ESAT-6 family proteins of Mycobacterium tuberculosis

    SciTech Connect

    Shi, Junwei; Zhang, Huan; Fang, Liurong; Xi, Yongqiang; Zhou, Yanrong; Luo, Rui; Wang, Dang Xiao, Shaobo; Chen, Huanchun

    2014-10-03

    Highlights: • We developed a novel firefly luciferase based biosensor to detect apoptosis. • The novel biosensor 233-DnaE-DEVDG was reliable, sensitive and convenient. • 233-DnaE-DEVDG faithfully indicated ESAT-6 family proteins of Mycobacterium tuberculosis induced apoptosis. • EsxA, esxT and esxL in ESAT-6 family proteins induced apoptosis. • Activation of nuclear factor-κB (NF-κB) participated in esxT-induced apoptosis. - Abstract: The activation of caspase-3 is a key surrogate marker for detecting apoptosis. To quantitate caspase-3 activity, we constructed a biosensor comprising a recombinant firefly luciferase containing a caspase-3 cleavage site. When apoptosis was induced, caspase-3 cleavage of the biosensor activated firefly luciferase by a factor greater than 25. The assay conveniently detected apoptosis in real time, indicating that it will facilitate drug discovery. We screened ESAT-6 family proteins of Mycobacterium tuberculosis and found that esxA, esxT and esxL induced apoptosis. Further, activation of nuclear factor-κB (NF-κB) and the NF-κB-regulated genes encoding tumor necrosis factor-α (TNF-α) and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) participated in esxT-induced apoptosis. We conclude that this assay is useful for high-throughput screening to identify and characterize proteins and drugs that regulate apoptosis.

  9. Label-free signal-on aptasensor for sensitive electrochemical detection of arsenite.

    PubMed

    Cui, Lin; Wu, Jie; Ju, Huangxian

    2016-05-15

    A signal-on aptasensor was fabricated for highly sensitive and selective electrochemical detection of arsenite with a label-free Ars-3 aptamer self-assembled on a screen-printed carbon electrode (SPCE) via Au-S bond. The Ars-3 aptamer could adsorb cationic polydiallyldimethylammonium (PDDA) via electrostatic interaction to repel other cationic species. In the presence of arsenite, the change of Ars-3 conformation due to the formation of Ars-3/arsenite complex led to less adsorption of PDDA, and the complex could adsorb more positively charged [Ru(NH3)6](3+) as an electrochemically active indicator on the aptasensor surface, which produced a sensitive "turn-on" response. The target-induced structure switching could be used for sensitive detection of arsenite with a linear range from 0.2 nM to 100 nM and a detection limit down to 0.15 nM. Benefiting from Ars-3 aptamer, the proposed system exhibited excellent specificity against other heavy metal ions. The SPCE-based aptasensor exhibited the advantages of low cost and simple fabrication, providing potential application of arsenite detection in environment.

  10. Bozepinib, a novel small antitumor agent, induces PKR-mediated apoptosis and synergizes with IFNα triggering apoptosis, autophagy and senescence.

    PubMed

    Marchal, Juan Antonio; Carrasco, Esther; Ramirez, Alberto; Jiménez, Gema; Olmedo, Carmen; Peran, Macarena; Agil, Ahmad; Conejo-García, Ana; Cruz-López, Olga; Campos, Joaquin María; García, María Ángel

    2013-01-01

    Bozepinib [(RS)-2,6-dichloro-9-[1-(p-nitrobenzenesulfonyl)-1,2,3,5-tetrahydro-4,1-benzoxazepin-3-yl]-9H-purine] is a potent antitumor compound that is able to induce apoptosis in breast cancer cells. In the present study, we show that bozepinib also has antitumor activity in colon cancer cells, showing 50% inhibitory concentration (IC50) values lower than those described for breast cancer cells and suggesting great potential of this synthetic drug in the treatment of cancer. We identified that the double-stranded RNA-dependent protein kinase (PKR) is a target of bozepinib, being upregulated and activated by the drug. However, p53 was not affected by bozepinib, and was not necessary for induction of apoptosis in either breast or colon cancer cells. In addition, the efficacy of bozepinib was improved when combined with the interferon-alpha (IFNα) cytokine, which enhanced bozepinib-induced apoptosis with involvement of protein kinase PKR. Moreover, we report here, for the first time, that in combined therapy, IFNα induces a clear process of autophagosome formation, and prior treatment with chloroquine, an autophagy inhibitor, is able to significantly reduce IFNα/bozepinib-induced cell death. Finally, we observed that a minor population of caspase 3-deficient MCF-7 cells persisted during long-term treatment with lower doses of bozepinib and the bozepinib/IFNα combination. Curiously, this population showed β-galactosidase activity and a percentage of cells arrested in S phase, that was more evident in cells treated with the bozepinib/IFNα combination than in cells treated with bozepinib or IFNα alone. Considering the resistance of some cancer cells to conventional chemotherapy, combinations enhancing the diversity of the cell death outcome might succeed in delivering more effective and less toxic chemotherapy.

  11. Infection-induced bystander-apoptosis of monocytes is TNF-alpha-mediated.

    PubMed

    Dreschers, Stephan; Gille, Christian; Haas, Martin; Grosse-Ophoff, Julia; Schneider, Marion; Leiber, Anja; Bühring, Hans-Jörg; Orlikowsky, Thorsten W

    2013-01-01

    Phagocytosis induced cell death (PICD) is crucial for controlling phagocyte effector cells, such as monocytes, at sites of infection, and essentially contributes to termination of inflammation. Here we tested the hypothesis, that during PICD bystander apoptosis of non-phagocyting monocytes occurs, that apoptosis induction is mediated via tumor necrosis factor-alpha (TNF-α and that TNF-α secretion and -signalling is causal. Monocytes were infected with Escherichia coli (E. coli), expressing green fluorescent protein (GFP), or a pH-sensitive Eos-fluorescent protein (EOS-FP). Monocyte phenotype, phagocytic activity, apoptosis, TNF-receptor (TNFR)-1, -2-expression and TNF-α production were analyzed. Apoptosis occured in phagocyting and non-phagocyting, bystander monocytes. Bacterial transport to the phagolysosome was no prerequisite for apoptosis induction, and desensitized monocytes from PICD, as confirmed by EOS-FP expressing E. coli. Co-cultivation with non-infected carboxyfluorescein-succinimidyl-ester- (CFSE-) labelled monocytes resulted in significant apoptotic cell death of non-infected bystander monocytes. This process required protein de-novo synthesis and still occurred in a diminished way in the absence of cell-cell contact. E. coli induced a robust TNF-α production, leading to TNF-mediated apoptosis in monocytes. Neutralization with an anti-TNF-α antibody reduced monocyte bystander apoptosis significantly. In contrast to TNFR2, the pro-apoptotic TNFR1 was down-regulated on the monocyte surface, internalized 30 min. p.i. and led to apoptosis predominantly in monocytes without phagocyting bacteria by themselves. Our results suggest, that apoptosis of bystander monocytes occurs after infection with E. coli via internalization of TNFR1, and indicate a relevant role for TNF-α. Modifying monocyte apoptosis in sepsis may be a future therapeutic option.

  12. LR-90 prevents methylglyoxal-induced oxidative stress and apoptosis in human endothelial cells.

    PubMed

    Figarola, James L; Singhal, Jyotsana; Rahbar, Samuel; Awasthi, Sanjay; Singhal, Sharad S

    2014-05-01

    Methylglyoxal (MGO) is a highly reactive dicarbonyl compound known to induce cellular injury and cytoxicity, including apoptosis in vascular cells. Vascular endothelial cell apoptosis has been implicated in the pathophysiology and progression of atherosclerosis. We investigated whether the advanced glycation end-product inhibitor LR-90 could prevent MGO-induced apoptosis in human umbilical vascular endothelial cells (HUVECs). HUVECs were pre-treated with LR-90 and then stimulated with MGO. Cell morphology, cytotoxicity and apoptosis were evaluated by light microscopy, MTT assay, and Annexin V-FITC and propidium iodide double staining, respectively. Levels of Bax, Bcl-2, cytochrome c, mitogen-activated protein kinases (MAPKs) and caspase activities were assessed by Western blotting. Reactive oxygen species (ROS) generation and mitochondrial membrane potential (MMP) were measured with fluorescent probes. LR-90 dose-dependently prevented MGO-associated HUVEC cytotoxicity and apoptotic biochemical changes such as loss of MMP, increased Bax/Bcl-2 protein ratio, mitochondrial cytochrome c release and activation of caspase-3 and 9. Additionally, LR-90 blocked intracellular ROS formation and MAPK (p44/p42, p38, JNK) activation, though the latter seem to be not directly involved in MGO-induced HUVEC apoptosis. LR-90 prevents MGO-induced HUVEC apoptosis by inhibiting ROS and associated mitochondrial-dependent apoptotic signaling cascades, suggesting that LR-90 possess cytoprotective ability which could be beneficial in prevention of diabetic related-atherosclerosis.

  13. Peroxynitrite induces apoptosis in canine cerebral vascular muscle cells: possible relation to neurodegenerative diseases and strokes.

    PubMed

    Li, Jianfeng; Su, Jialin; Li, Wenyan; Liu, Weimin; Altura, Bella T; Altura, Burton M

    2003-10-30

    Considerable evidence is accumulating to suggest that in vivo formation of free radicals in the brain, such as peroxynitrite (ONOO-), and programmed cell death (i.e. apoptosis) play important roles in neurodegeneration and stroke. However, it is not known whether ONOO- can induce apoptosis in cerebral vascular smooth muscle cells (CVSMCs). The present study was designed to determine whether or not canine CVSMCs undergo apoptosis following treatment with ONOO-. Direct exposure of canine CVSMCs to ONOO- induced apoptosis in a concentration-dependent manner, as confirmed by means of fluorescence staining, TdT-mediated dUTP nick-end labeling and comet assays. Peroxynitrite treatment resulted in an elevation of [Ca2+]i in the CVSMCs. Peroxynitrite-induced apoptosis may thus be brought about by activation of Ca2+-dependent endonucleases. Although the precise mechanisms by which peroxynitrite induces apoptosis need to be further investigated, the present findings could be used to suggest that ONOO- formation in the brain may play important roles in neurodegenerative processes and strokes via detrimental actions on cerebral microvessels and blood flow.

  14. The mitochondrial and death receptor pathways involved in the thymocytes apoptosis induced by aflatoxin B1

    PubMed Central

    Chi, Xiaofeng; Li, Xiaochong; Jiang, Min; Fang, Jing; Cui, Hengmin; Lai, Weimin; Zhou, Yi; Zhou, Shan

    2016-01-01

    Aflatoxin B1 (AFB1) is a potent immunosuppressive agent in endotherms, which can be related to the up-regulated apoptosis of immune organs. In this study, we investigated the roles of the mitochondrial, death receptor, and endoplasmic reticulum pathways in Aflatoxin B1 induced thymocytes apoptosis. Chickens were fed an aflatoxin B1 containing diet (0.6 mg/kg AFB1) for 3 weeks. Our results showed that (1) AFB1 diet induced the decrease of T-cell subsets, morphological changes, and excessive apoptosis of thymus. (2) The excessive apoptosis involved the mitochondrial pathway (up-regulation of Bax, Bak, cytC and down-regulation of Bcl-2 and Bcl-xL) and death receptor pathway (up-regulation of FasL, Fas and FADD). (3) Oxidative stress, an apoptosis inducer, was confirmed in the thymus. In conclusion, this is the first study to demonstrate that mitochondrial and death receptor pathways involved in AFB1 induced thymocytes apoptosis in broilers. PMID:26933817

  15. Drosophila MOF regulates DIAP1 and induces apoptosis in a JNK dependent pathway.

    PubMed

    Pushpavalli, Sreerangam N C V L; Sarkar, Arpita; Ramaiah, M Janaki; Koteswara Rao, G; Bag, Indira; Bhadra, Utpal; Pal-Bhadra, Manika

    2016-03-01

    Histone modulations have been implicated in various cellular and developmental processes where in Drosophila Mof is involved in acetylation of H4K16. Reduction in the size of larval imaginal discs is observed in the null mutants of mof with increased apoptosis. Deficiency involving Hid, Reaper and Grim [H99] alleviated mof (RNAi) induced apoptosis in the eye discs. mof (RNAi) induced apoptosis leads to activation of caspases which is suppressed by over expression of caspase inhibitors like P35 and Diap1 clearly depicting the role of caspases in programmed cell death. Also apoptosis induced by knockdown of mof is rescued by JNK mutants of bsk and tak1 indicating the role of JNK in mof (RNAi) induced apoptosis. The adult eye ablation phenotype produced by ectopic expression of Hid, Rpr and Grim, was restored by over expression of Mof. Accumulation of Mof at the Diap1 promoter 800 bp upstream of the transcription start site in wild type larvae is significantly higher (up to twofolds) compared to mof (1) mutants. This enrichment coincides with modification of histone H4K16Ac indicating an induction of direct transcriptional up regulation of Diap1 by Mof. Based on these results we propose that apoptosis triggered by mof (RNAi) proceeds through a caspase-dependent and JNK mediated pathway.

  16. Cadmium induces apoptosis and genotoxicity in rainbow trout hepatocytes through generation of reactive oxygene species.

    PubMed

    Risso-de Faverney, C; Devaux, A; Lafaurie, M; Girard, J P; Bailly, B; Rahmani, R

    2001-06-01

    Cadmium poses a serious environmental threat in aquatic ecosystems but the mechanisms of its toxicity remain unclear. The purpose of this work was first to determine whether cadmium induced apoptosis in trout hepatocytes, second to determine whether or not reactive oxygen species (ROS) were involved in cadmium-induced apoptosis and genotoxicity. Hepatocytes exposed to increasing cadmium concentrations (in the range of 1-10 microM) showed a molecular hallmark of apoptosis which is the fragmentation of the nuclear DNA into oligonucleosomal-length fragments, resulting from an activation of endogenous endonucleases and recognized as a 'DNA ladder' on conventional agarose gel electrophoresis. Exposure of hepatocytes to cadmium led clearly to the DEVD-dependent protease activation, acting upstream from the endonucleases and considered as central mediators of apoptosis. DNA strand breaks in cadmium-treated trout hepatocytes was assessed using the comet assay, a rapid and sensitive single-cell gel electrophoresis technique used to detect DNA primary damage in individual cells. Simultaneous treatment of trout hepatocytes with cadmium and the nitroxide radical TEMPO used as a ROS scavenger, reduced significantly DNA fragmentation, DEVD-related protease activity and DNA strand breaks formation. These results lead to a working hypothesis that cadmium-induced apoptosis and DNA strand breaks in trout hepatocytes are partially triggered by the generation of ROS. Additional studies are required for proposing a mechanistic model of cadmium-induced apoptosis and genotoxicity in trout liver cells, in underlying the balance between DNA damage and cellular defence systems in fish.

  17. Noscapine induces mitochondria-mediated apoptosis in human colon cancer cells in vivo and in vitro.

    PubMed

    Yang, Zi-Rong; Liu, Meng; Peng, Xiu-Lan; Lei, Xiao-Fei; Zhang, Ji-Xiang; Dong, Wei-Guo

    2012-05-11

    Noscapine, a phthalide isoquinoline alkaloid derived from opium, has been widely used as a cough suppressant for decades. Noscapine has recently been shown to potentiate the anti-cancer effects of several therapies by inducing apoptosis in various malignant cells without any detectable toxicity in cells or tissues. However, the mechanism by which noscapine induces apoptosis in colon cancer cells remains unclear. The signaling pathways by which noscapine induces apoptosis were investigated in colon cancer cell lines treated with various noscapine concentrations for 72 h, and a dose-dependent inhibition of cell viability was observed. Noscapine effectively inhibited the proliferation of LoVo cells in vitro (IC(50)=75 μM). This cytotoxicity was reflected by cell cycle arrest at G(2)/M and subsequent apoptosis, as indicated by increased chromatin condensation and fragmentation, the upregulation of Bax and cytochrome c (Cyt-c), the downregulation of survivin and Bcl-2, and the activation of caspase-3 and caspase-9. Moreover, in a xenograft tumor model in mice, noscapine injection clearly inhibited tumor growth via the induction of apoptosis, which was demonstrated using a TUNEL assay. These results suggest that noscapine induces apoptosis in colon cancer cells via mitochondrial pathways. Noscapine may be a safe and effective chemotherapeutic agent for the treatment of human colon cancer.

  18. RhoA and p38 MAPK mediate apoptosis induced by cellular cholesterol depletion.

    PubMed

    Calleros, Laura; Lasa, Marina; Rodríguez-Alvarez, Francisco J; Toro, María J; Chiloeches, Antonio

    2006-07-01

    Cholesterol is essential for cell viability, and homeostasis of cellular cholesterol is crucial to various cell functions. Here we examined the effect of cholesterol depletion on apoptosis and the mechanisms underlying this effect in NIH3T3 cells. We show that chronic cholesterol depletion achieved with lipoprotein-deficient serum (LPDS) and 25-hydroxycholesterol (25-HC) treatment resulted in a significant increase in cellular apoptosis and caspase-3 activation. This effect is not due to a deficiency of nonsterol isoprenoids, intermediate metabolites of the cholesterol biosynthetic pathway, but rather to low cholesterol levels, since addition of cholesterol together with LPDS and 25-HC nearly abolished apoptosis, whereas addition of farnesyl pyrophosphate or geranylgeranyl-pyrophosphate did not reverse the cell viability loss induced by LPDS plus 25-HC treatment. These effects were accompanied by an increase in ERK, JNK and p38 MAPK activity. However, only the inhibition of p38 MAPK with the specific inhibitor SB203580 or the overexpression of a kinase defective MKK6 resulted in a significant decrease in apoptosis and caspase-3 cleavage induced by cholesterol depletion. Furthermore, LPDS plus 25-HC increased RhoA activity, and this effect was reversed by addition of exogenous cholesterol. Finally, overexpression of the dominant negative N19RhoA inhibited p38 MAPK phosphorylation and apoptosis induced by low cholesterol levels. Together, our results demonstrate that cholesterol depletion induces apoptosis through a RhoA- and p38 MAPK-dependent mechanism.

  19. Stimulation through CD50 preferentially induces apoptosis of TCR1+ human peripheral blood lymphocytes.

    PubMed

    López-Briones, S; Portales-Pérez, D P; Baranda, L; de la Fuente, H; Rosenstein, Y; González-Amaro, R

    1998-01-01

    Apoptosis has an important role in several key immunological phenomena such as regulation of the immune response, and deletion of auto-reactive cells. This phenomenon is induced following the interaction of several cell membrane receptors with their respective ligands or after cell activation. We have studied the possible effect of signaling through CD50/ICAM-3 and CD69/AIM on apoptosis of peripheral blood lymphocytes. Apoptosis was assessed by both flow cytometry analysis (content of cell DNA and binding to annexin V), and detection of DNA fragmentation by agarose gel electrophoresis. We found that a stimulatory anti-CD50 mAb was able to induce a small but significant degree of apoptosis in resting peripheral blood mononuclear cells from most donors; this effect was dose-dependent and was evident as early as at 12 h, with a maximal induction at 48 h. Studies with T and non-T cells showed that only the former cell population was sensitive to the induction of apoptosis through CD50. Further experiments revealed that the anti-ICAM-3 mAb preferentially induced apoptosis of TCR gamma delta-bearing cells. In addition, we found a significant increase in Cai2+ in PBMC stimulated with an anti-CD50 mAb, suggesting the involvement of this signaling pathway in the induction of apoptosis through this adhesion receptor. In contrast, under our experimental conditions, stimulation through CD69 did not have any effect on the induction of apoptosis on either cultured T lymphoblasts or PMA-stimulated PBMC. Our findings suggest that the interaction of CD50 with its natural ligand LFA-1 results in the induction of apoptosis in a significant fraction of resting PBMC. This phenomenon may be involved in immune regulation, lymphocyte turnover and peripheral deletion of auto-reactive cells.

  20. Resistance to etoposide-induced apoptosis in a Burkitt's lymphoma cell line.

    PubMed

    Zhao, E G; Song, Q; Cross, S; Misko, I; Lees-Miller, S P; Lavin, M F

    1998-08-31

    Burkitt's lymphoma cells that vary in their phenotypic characteristics show significantly different degrees of susceptibility to radiation-induced apoptosis. Propensity to undergo apoptosis is reflected in the degradation of substrates such as DNA-dependent protein kinase but the status of bcl-2, c-myc and p53 has been uninformative. In this study, we have focused on 2 Epstein-Barr virus (EBV)-associated Burkitt's cell lines, one (WW2) susceptible and the other (BL29) resistant to etoposide-induced apoptosis. Differences in expression of BHRF1, an EBV gene that is homologous to the Bcl-2 proto-oncogene and known to inhibit apoptosis, or changes in apoptosis inhibitory proteins (IAPs), did not appear to account for the difference in susceptibility in the 2 cell lines. Cytoplasmic extracts from etoposide-treated WW2 cells caused apoptotic changes in nuclei isolated from either BL29 or WW2 cells, whereas extracts from BL29 cells failed to do so. In addition, extracts from etoposide-treated WW2 cells degraded the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs), an important indicator of apoptosis, but this protein was resistant to degradation by BL29 extracts. It appears likely that caspase 3 (CPP32) is involved in this degradation since it was activated only in the apoptosis susceptible cells and the pattern of cleavage of DNA-PKcs was similar to that reported previously with recombinant caspase 3. As observed previously, addition of caspase 3 to nuclei failed to induce morphological changes indicative of apoptosis, but addition of caspase 3 to nuclei in the presence of extract from the resistant cells led to apoptotic changes. We conclude that resistance to apoptosis in BL29 cells is due to a failure of etoposide to activate upstream effectors of caspase activity.

  1. PUMA is invovled in ischemia/reperfusion-induced apoptosis of mouse cerebral astrocytes.

    PubMed

    Chen, H; Tian, M; Jin, L; Jia, H; Jin, Y

    2015-01-22

    PUMA (p53-upregulated modulator of apoptosis), a BH3-only member of the Bcl-2 protein family, is required for p53-dependent and p53-independent forms of apoptosis. PUMA has been invovled in the onset and progress of several diseases, including cancer, acquired immunodeficiency syndrome, and ischemic brain disease. Although many studies have shown that ischemia and reperfusion (I/R) can induce the apoptosis of astrocytes, the role of PUMA in I/R-mediated apoptosis of cerebral astrocyte apoptosis remains unclear. To mimic in vivo I/R conditions, primary mouse cerebral astrocytes were incubated in a combinational cultural condition of oxygen, glucose, and serum deprivation (OSGD) for 1 h followed by reperfusion (OSGD/R). Cell death determination assays and cell viability assays indicated that OSGD and OSGD/R induce the apoptosis of primary cerebral astrocytes. The expression of PUMA was significantly elevated in primary cerebral astrocytes during OSGD/R. Moreover, targeted down-regulation of PUMA by siRNA transfection significantly decreased the OSGD/R-induced apoptosis of primary cerebral astrocytes. We also found that OSGD and OSGD/R triggered the release of cytochrome c in astrocytes, indicating the dependence on a mitochondrial apoptotic pathway. Reactive oxygen species (ROS) was extremely generated during OSGD and OSGD/R, and the elimination of ROS by treated with N-acetyl-L-cysteine (NAC) remarkably inhibited the expression of PUMA and the apoptosis of primary cerebral astrocytes. The activation of Caspase 3 and Caspase 9 was extremely elevated in primary cerebral astrocytes during OSGD. In addition, we found that knockdown of PUMA led to the depressed expression of Bax, cleaved caspase-9 and caspase-3 during OSGD/R. These results indicate that PUMA is invovled in the apoptosis of cerebral astrocytes upon I/R injury.

  2. FasL and TRAIL Induce Epidermal Apoptosis and Skin Ulceration Upon Exposure to Leishmania major

    PubMed Central

    Eidsmo, Liv; Fluur, Caroline; Rethi, Bence; Eriksson Ygberg, Sofia; Ruffin, Nicolas; De Milito, Angelo; Akuffo, Hannah; Chiodi, Francesca

    2007-01-01

    Receptor-mediated apoptosis is proposed as an important regulator of keratinocyte homeostasis in human epidermis. We have previously reported that Fas/FasL interactions in epidermis are altered during cutaneous leishmaniasis (CL) and that keratinocyte death through apoptosis may play a pathogenic role for skin ulceration. To further investigate the alterations of apoptosis during CL, a keratinocyte cell line (HaCaT) and primary human epidermal keratinocytes were incubated with supernatants from Leishmania major-infected peripheral blood mononuclear cells. An apoptosis-specific microarray was used to assess mRNA expression in HaCaT cells exposed to supernatants derived from L. major-infected cultures. Fas and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) mRNA and protein expression were significantly up-regulated, and apoptosis was detected in both HaCaT and human epidermal keratinocyte cells. The keratinocyte apoptosis was partly inhibited through blocking of Fas or FasL and even more efficiently through TRAIL neutralization. Up-regulation of Fas on keratinocytes in epidermis and the presence of FasL-expressing macrophages and T cells in dermis were previously reported by us. In this study, keratinocytes expressing TRAIL, as well as the proapoptotic receptor TRAIL-R2, were detected in skin biopsies from CL cases. We propose that activation of Fas and TRAIL apoptosis pathways, in the presence of inflammatory mediators at the site of infection, leads to tissue destruction and ulceration during CL. PMID:17200196

  3. Bisphenol A diglycidyl ether-induced apoptosis involves Bax/Bid-dependent mitochondrial release of apoptosis-inducing factor (AIF), cytochrome c and Smac/DIABLO

    PubMed Central

    Fehlberg, Sebastian; Gregel, Cornelia M; Göke, Alexandra; Göke, Rüdiger

    2003-01-01

    Bisphenol A diglycidyl ether (BADGE) is a peroxisome proliferator-activated receptor-γ (PPAR-γ) antagonist, which is able to induce apoptosis in tumor cells independently of PPAR-γ in caspase-dependent and -independent manners. Additionally, BADGE promotes TRAIL-induced apoptosis. We report that BADGE activates via Bax and caspases-2 and -8 both the intrinsic and extrinsic apoptotic pathways using Bid as a shunt. BADGE stimulates the mitochondrial release of apoptosis-inducing factor (AIF), cytochrome c and second mitochondria-derived activator of caspase/direct IAP-binding protein with low pl (Smac/DIABLO). The release of cytochrome c could not be blocked by inhibitors of caspases-3, -8 and -9 indicating that BADGE acts upstream of caspases-3 and -9 and does not involve caspase-8 to release cytochrome c. While the caspase-independent apoptotic effect might be mediated by AIF, the sensitizing effect of BADGE against other apoptotic substances is most likely mediated by the X-linked inhibitor of apoptosis inhibitor Smac/DIABLO. Our data suggest that BADGE or BADGE derivatives could represent promising substances for the treatment of neoplasms improving the antitumoral activity of TRAIL. PMID:12788809

  4. A viral vector expressing hypoxia-inducible factor 1 alpha inhibits hippocampal neuronal apoptosis

    PubMed Central

    Chai, Xiqing; Kong, Weina; Liu, Lingyun; Yu, Wenguo; Zhang, Zhenqing; Sun, Yimin

    2014-01-01

    Hypoxia-inducible factor 1 (HIF-1) attenuates amyloid-beta protein neurotoxicity and decreases apoptosis induced by oxidative stress or hypoxia in cortical neurons. In this study, we constructed a recombinant adeno-associated virus (rAAV) vector expressing the human HIF-1α gene (rAAV-HIF-1α), and tested the assumption that rAAV-HIF-1α represses hippocampal neuronal apoptosis induced by amyloid-beta protein. Our results confirmed that rAAV-HIF-1α significantly reduces apoptosis induced by amyloid-beta protein in primary cultured hippocampal neurons. Direct intracerebral rAAV-HIF-1α administration also induced robust and prolonged HIF-1α production in rat hippocampus. Single rAAV-HIF-1α administration resulted in decreased apoptosis of hippocampal neurons in an Alzheimer's disease rat model established by intracerebroventricular injection of aggregated amyloid-beta protein (25–35). Our in vitro and in vivo findings demonstrate that HIF-1 has potential for attenuating hippocampal neuronal apoptosis induced by amyloid-beta protein, and provides experimental support for treatment of neurodegenerative diseases using gene therapy. PMID:25206774

  5. Phenylethanoid glycosides from Cistanches salsa inhibit apoptosis induced by 1-methyl-4-phenylpyridinium ion in neurons.

    PubMed

    Tian, Xue-Fei; Pu, Xiao-Ping

    2005-02-10

    In our study we investigated the neuroprotective effects of phenylethanoid glycosides (PhGs) from Cistanches salsa on 1-methyl-4-phenylpyridinium ion (MPP(+))-induced apoptosis in cerebellar granule neurons (CGNs). CGNs were treated with 100 microM MPP(+) for 24h to induce apoptosis, simultaneously CGNs were incubated with PhGs at 10, 20 and 40 microg/ml, respectively. In addition CGNs were pretreated with PhGs at 20 microg/ml for 6, 12, 24 h, respectively, and then treated with 100 microM MPP(+) for 24 h. 3-(4,5-Dimethylthiazol-2-ylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay revealed that the treatment of CGNs with PhGs inhibited the decrease of cell viability induced by MPP(+). The activation of caspase-3 and caspase-8 was induced by MPP(+) in apoptosis. The caspase-3 and caspase-8 fluorogenic assays showed that the treatments of CGNs with PhGs efficiently suppressed the activation of caspase-3 and caspase-8 induced by MPP(+). It is concluded that PhGs can prevent the MPP(+)-induced apoptosis in CGNs and exert its anti-apoptosis effect by inhibiting caspase-3 and caspase-8 activities.

  6. Angiotensin protects cortical neurons from hypoxic-induced apoptosis via the angiotensin type 2 receptor.

    PubMed

    Grammatopoulos, Tom; Morris, Katherine; Ferguson, Paul; Weyhenmeyer, James

    2002-03-28

    The effects of angiotensin on mouse cortical neuronal cultures exposed to chemical-induced hypoxia was investigated. Cultures exposed to 10 mM sodium azide for 5 min showed a 17% increase in apoptosis when assayed 24 h postinsult. The N-methyl-D-aspartate (NMDA) receptor antagonist MK-801 blocked sodium azide-induced cell death suggesting that the NMDA receptor contributes to the mediated cell death. Pretreatment of cultured neurons with angiotensin decreased sodium azide-induced apoptosis by 94%. When the AT(1) receptor was blocked by its receptor antagonist, losartan, angiotensin activation of the AT(2) receptor completely inhibited sodium azide-induced apoptosis. Pretreatment of neurons with the AT(2) receptor antagonist PD123319 resulted in angiotensin reducing sodium azide-induced apoptosis by 48%. These results demonstrate that angiotensin can significantly attenuate sodium azide-induced apoptosis primarily through activation of the AT(2) receptor and suggests that angiotensin may have a protective role in neurons undergoing ischemic injury.

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

    PubMed

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

    2009-10-02

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

  8. Radiation-induced apoptosis in human lymphocytes: Potential as a biological dosimeter

    SciTech Connect

    Boreham, D.R.; Gale, K.L.; Maves, S.R.; Walker, J.A.; Morrison, D.P.

    1996-11-01

    We have tested the possibility of using apoptosis (programmed cell death) in human peripheral blood lymphocytes as a short-term biological dosimeter. Lymphocytes isolated from whole blood were irradiated in culture with 250 kVp x-rays or {sup 60}Co gamma rays. Two assays were used to measure apoptosis in lymphocytes after irradiation: in situ terminal deoxynucleotidyl transferase assay and fluorescence analysis of DNA unwinding assay. Similar qualitative and quantitative results were produced by the assays, supporting the notion that the fluorescence analysis of DNA unwinding assay measured DNA fragmentation associated with apoptosis. Induction of apoptosis in lymphocytes irradiated in vitro was proportional to dose and could be detected following exposures as low as 0.05 Gy. Lymphocytes irradiated in vitro was proportional to dose and could be detected following exposures as low as 0.05 Gy. Lymphocytes from individual donors had reproducible dose responses. There was, however, variation between donors. X-ray and gamma-ray exposures induced similar levels of apoptosis at similar doses. The induction kinetics of apoptosis in vitro indicate a maximum is reached about 72 h after irradiation. In conclusion, the in vitro experimental evidence indicates that radiation-induced apoptosis in human lymphocytes has the kinetics, sensitivity, and reproductibility to be a potential biological dosimeter. 29 refs., 5 figs.

  9. Novel targets for endoplasmic reticulum stress-induced apoptosis in B-CLL.

    PubMed

    Rosati, Emanuela; Sabatini, Rita; Rampino, Giuliana; De Falco, Filomena; Di Ianni, Mauro; Falzetti, Franca; Fettucciari, Katia; Bartoli, Andrea; Screpanti, Isabella; Marconi, Pierfrancesco

    2010-10-14

    A better understanding of apoptotic signaling in B-chronic lymphocytic leukemia (B-CLL) cells may help to define new therapeutic strategies. This study investigated endoplasmic reticulum (ER) stress signaling in spontaneous apoptosis of B-CLL cells and whether manipulating ER stress increases their apoptosis. Results show that a novel ER stress-triggered caspase cascade, initiated by caspase-4 and involving caspase-8 and -3, plays an important role in spontaneous B-CLL cell apoptosis. ER stress-induced apoptosis in B-CLL cells also involves CHOP/GADD153 up-regulation, increased JNK1/2 phosphorylation, and caspase-8-mediated cleavage of Bap31 to Bap20, known to propagate apoptotic signals from ER to mitochondria. In ex vivo B-CLL cells, some apoptotic events associated with mitochondrial pathway also occur, including mitochondrial cytochrome c release and caspase-9 processing. However, pharmacologic inhibition studies show that caspase-9 plays a minor role in B-CLL cell apoptosis. ER stress also triggers survival signals in B-CLL cells by increasing BiP/GRP78 expression. Manipulating ER signaling by siRNA down-regulation of BiP/GRP78 or treating B-CLL cells with 2 well-known ER stress-inducers, tunicamycin and thapsigargin, increases their apoptosis. Overall, our findings show that ER triggers an essential pathway for B-CLL cell apoptosis and suggest that genetic and pharmacologic manipulation of ER signaling could represent an important therapeutic strategy.

  10. Chinese herbal medicine Yougui Pill reduces exogenous glucocorticoid-induced apoptosis in anterior pituitary cells

    PubMed Central

    Ji, Yong-zhi; Geng, Long; Zhou, Hong-bo; Wei, Hua-chen; Chen, Hong-duo

    2016-01-01

    Long-term glucocorticoid use may result in sustained suppression of one or more secreted components from the hypothalamo-pituitary-adrenal axis, and often results in apoptosis. Yougui Pill (YGP), a 10-component traditional Chinese herbal medicine, has been shown to be clinically effective for glucocorticoid-induced suppression of the hypothalamo-pituitary-adrenal axis. However, the pharmacological and molecular mechanisms remain unclear. We hypothesized that YGP would exert an anti-apoptosis effect on dexamethasone-treated anterior pituitary cells. In vivo experiments showed that YGP significantly reduced the number of apoptotic cells, down-regulated mRNA expression of cytochrome c, caspase-3, and caspase-9, and up-regulated mRNA expression of Bcl-2. These findings suggest that YGP reduced glucocorticoid-induced apoptosis in rat anterior pituitary cells by regulating the mitochondria-mediated apoptosis pathway. PMID:28197193

  11. Baicalin inhibits colistin sulfate-induced apoptosis of PC12 cells.

    PubMed

    Jiang, Hong; Lv, Pengfei; Li, Jichang; Wang, Hongjun; Zhou, Tiezhong; Liu, Yingzi; Lin, Wei

    2013-10-05

    Baicalin, a type of flavonoid extracted from the dried root of Scutellaria baicalensis georgi, has been shown to effectively inhibit cell apoptosis. Therefore, we assumed that baicalin would suppress co-listin sulfate-induced neuronal apoptosis. PC12 cells exposed to colistin sulfate (62.5-500 μg/mL) for 24 hours resulted in PC12 cell apoptosis. In addition, caspase-3 activity, lactate dehydrogenase level and free radical content increased in a dose-dependent manner. Subsequently, PC12 cells were pretreated with baicalin (25, 50 and 100 μg/mL), and exposed to 125 μg/mL colistin sulfate. Cell morphology markedly changed, and cell viability increased. Moreover, caspase-3 activity, tate dehydrogenase level and free radical content decreased. Results indicated that baicalin inhi-bited colistin sulfate-induced PC12 cell apoptosis by suppressing free radical injury, and reducing caspase-3 activity and lactate dehydrogenase activity.

  12. Recessive mutations in a common pathway block thymocyte apoptosis induced by multiple signals

    PubMed Central

    1994-01-01

    The glucocorticoid receptor (GR) is a ligand-regulated transcription factor that controls genes necessary to initiate glucocorticoid-induced thymocyte apoptosis. We have performed a genetic analysis of thymocyte cell death by isolating and characterizing a panel of GR+ dexamethasone- resistant mutants of the murine WEHI7.2 thymocyte cell line. These apoptosis-defective (Apt-) mutants were used to identify previously unknown early steps in the apoptotic pathway. The Apt- mutants contain nonglucocorticoid receptor, recessive mutations in genes that represent multiple complementation groups. These mutations block apoptosis induced by dexamethasone, gamma irradiation, and c-AMP treatment before the point where Bcl-2 exerts its protective effect. We propose that different signals share a common apoptotic pathway, and that the induction of apoptosis involves multiple precommitment steps that can be blocked by recessive mutations. PMID:7798323

  13. Mst1 is an interacting protein that mediates PHLPPs' induced apoptosis.

    PubMed

    Qiao, Meng; Wang, Yaqi; Xu, Xiaoen; Lu, Jing; Dong, Yongli; Tao, Wufan; Stein, Janet; Stein, Gary S; Iglehart, James D; Shi, Qian; Pardee, Arthur B

    2010-05-28

    PHLPP1 and PHLPP2 phosphatases exert their tumor-suppressing functions by dephosphorylation and inactivation of Akt in several breast cancer and glioblastoma cells. However, Akt, or other known targets of PHLPPs that include PKC and ERK, may not fully elucidate the physiological role of the multifunctional phosphatases, especially their powerful apoptosis induction function. Here, we show that PHLPPs induce apoptosis in cancer cells independent of the known targets of PHLPPs. We identified Mst1 as a binding partner that interacts with PHLPPs both in vivo and in vitro. PHLPPs dephosphorylate Mst1 on the T387 inhibitory site, which activate Mst1 and its downstream effectors p38 and JNK to induce apoptosis. The same T387 site can be phosphorylated by Akt. Thus, PHLPP, Akt, and Mst1 constitute an autoinhibitory triangle that controls the fine balance of apoptosis and proliferation that is cell type and context dependent.

  14. DNA damage and mitochondria dysfunction in cell apoptosis induced by nonthermal air plasma

    SciTech Connect

    Kim, G. J.; Lee, J. K.; Kim, W.; Kim, K. T.

    2010-01-11

    Nonthermal plasma is known to induce animal cell death but the mechanism is not yet clear. Here, cellular and biochemical regulation of cell apoptosis is demonstrated for plasma treated cells. Surface type nonthermal air plasma triggered apoptosis of B16F10 mouse melanoma cancer cells causing DNA damage and mitochondria dysfunction. Plasma treatment activated caspase-3, apoptosis executioner. The plasma treated cells also accumulated gamma-H2A.X, marker for DNA double strand breaks, and p53 tumor suppressor gene as a response to DNA damage. Interestingly, cytochrome C was released from mitochondria and its membrane potential was changed significantly.

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

    PubMed

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

    2015-01-01

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

  16. Formaldehyde induces apoptosis through decreased Prx 2 via p38 MAPK in lung epithelial cells.

    PubMed

    Lim, Seul Ki; Kim, Jong Chun; Moon, Chang Jong; Kim, Gye Yeop; Han, Ho Jae; Park, Soo Hyun

    2010-05-27

    Formaldehyde (FA) is an important substance that induces sick house syndrome and diseases, such as asthma and allergies. Oxidative stress is involved in the development of respiratory disease, and diverse antioxidants may protect respiratory tract cells from apoptosis. Peroxiredoxin is a pivotal endogenous antioxidant. In the present study, FA induced death in A549 cells, a lung epithelial cell line, in a dose-dependent manner. FA also increased lipid peroxide formation (LPO) in A549 cells, suggesting a role for oxidative stress. Additionally, FA decreased peroxiredoxin 2 (Prx 2) protein levels after a 24 or 48h exposure to FA. We also examined whether the FA-induced decrease in Prx 2 was associated with apoptosis. Prx 2 overexpression protected against FA-induced cell apoptosis but not necrosis. Prx 2 overexpression blocked FA-induced increase in Bax, a pro-apoptotic molecule, and a decrease in Bcl-2, an anti-apoptotic molecule. Prx 2 overexpression also protected against FA-induced activation of some special apoptosis-associated proteins [caspase-3, caspase-9, and polypeptide poly (ADP-ribose) polymerase (PARP)]. Furthermore, we examined the signaling molecules involved in the FA-induced decrease in Prx 2 expression. The FA-induced decrease in Prx 2 and increase in cell apoptosis was restored by treatment with SB203580 [a p38 mitogen activated protein kinase (MAPK) inhibitor], but not by SP600125 [a c-jun-N-terminal kinase (JNK) inhibitor]. Also, FA-induced events were blocked by treatment with p38 siRNA, but not by scrambled siRNA. Indeed, FA increased p38 MAPK activation, suggesting a role for p38 MAPK in FA action. In conclusion, FA mediated apoptosis in lung epithelial cells by decreasing Prx 2 via p38 MAPK.

  17. Resveratrol protects rabbit articular chondrocyte against sodium nitroprusside-induced apoptosis via scavenging ROS.

    PubMed

    Liang, Qian; Wang, Xiao-ping; Chen, Tong-sheng

    2014-09-01

    This study aims to investigate the mechanism by which resveratrol (RV) prevents sodium nitroprusside (SNP)-induced chondrocyte apoptosis, which is a characteristic feature of osteoarthritis (OA). Rabbit articular chondrocytes were pre-incubated with 100 μM RV for 18 h before 1.5 mM SNP co-treatment for 6 h. Cell viability was evaluated by CCK-8. Annexin V/PI double staining and Hoechst 33258 staining were used to determine the fashion of SNP-induced chondrocytes death. Mitochondrial membrane potential (ΔΨm) was measured by using flow cytometry (FCM) with TMRM and Rhodamine 123 staining. Intracellular reactive oxygen species (ROS) and nitric oxide (NO) levels were confirmed by FCM analysis with DCFH-DA and DAF-FM DA staining. Cytoskeleton proteins of chondrocytes co-stained with Actin-Trakcer Green and Tubulin-Trakcer Red were validated by confocal microscopy. SNP induced time- and dose-dependent chondrocytes apoptosis with decline of ΔΨm, activation of caspases as well as cytoskeletal remodeling. SNP induced a significant induction of both ROS and NO. RV remarkably prevented SNP-induced ROS production and apoptosis as well as cytoskeletal remodeling, but did not prevent SNP-induced NO production. Pretreatment with NO scavengers did not significantly prevent SNP-induced apoptosis and cytoskeletal remodeling. SNP induces NO-independent ROS production which dominates rabbit articular chondrocyte apoptosis, and RV protects chondrocytes against SNP-induced apoptosis via scavenging ROS instead of NO.

  18. Metabolic energy from arsenite oxidation in Alcaligenes faecalis

    NASA Astrophysics Data System (ADS)

    Anderson, G. L.; Love, M.; Zeider, B. K.

    2003-05-01

    The aerobic soil bacterium, Alcaligenes faecalis, survives in cultures containing greater than 10 g/L of aqueous arsenic. Toleration of arsenite occurs by the enzymatic oxidation of arsenite (As^III), to the less toxic arsenate (As^V). In defined media, the bacterium grows faster in the presence of arsenite than in its absence. This suggests that the bacterium uses the redox potential of arsenite oxidation as metabolic energy. The oxidation occurs via periplasmic arsenite oxidase, azurin, and cytochrome c [11] which presumably pass electron equivalents through an electron transport chain involving cytochrome c oxidase aud oxygen as the terminal electron acceptor. The associated proton translocation would allow synthesis of ATP and provide a useful means of harnessing the redox potential of arsenite oxidation. Arsenite and arsenate assays of the media during bacterial growth indicate that arsenite is depleted during the exponential growth phase and occurs concomitantly with the expression of arsenite oxidase. These results suggest that arsenite is detoxified to arsenate during bacterial growth and are inconsistent with previous reported interpretations of growth data. Alcaligenes faecalis is dependent on organic carbon sources and is therefore not chemolithoautotrophic. The relationship between succinate and arsenite utilisation provides evidence for the use of arsenite as a supplemental energy source. Because Alcaligenes faecalis not only tolerates, but thrives, in very high concentrations of arsenic has important implications in bioremediation of environments contaminated by aqueous arsenic.

  19. METHYLATION OF SODIUM ARSENITE BY VARIOUS MAMMALIAN CELLS

    EPA Science Inventory


    Methylation of Sodium Arsenite by various Mammalian Cells

    Methylation of arsenite (As 3-1) is thought to play an important role in the carcinogenicity of arsenic. AIM: I. Characterization of methylation of arsenite in primary rodent and transformed human cell lines. ...

  20. Asbestos-induced alveolar epithelial cell apoptosis. The role of endoplasmic reticulum stress response.

    PubMed

    Kamp, David W; Liu, Gang; Cheresh, Paul; Kim, Seok-Jo; Mueller, Amanda; Lam, Anna P; Trejo, Humberto; Williams, David; Tulasiram, Sandhya; Baker, Margaret; Ridge, Karen; Chandel, Navdeep S; Beri, Rohinee

    2013-12-01

    Asbestos exposure results in pulmonary fibrosis (asbestosis) and malignancies (bronchogenic lung cancer and mesothelioma) by mechanisms that are not fully understood. Alveolar epithelial cell (AEC) apoptosis is important in the development of pulmonary fibrosis after exposure to an array of toxins, including asbestos. An endoplasmic reticulum (ER) stress response and mitochondria-regulated (intrinsic) apoptosis occur in AECs of patients with idiopathic pulmonary fibrosis, a disease with similarities to asbestosis. Asbestos induces AEC intrinsic apoptosis, but the role of the ER is unclear. The objective of this study was to determine whether asbestos causes an AEC ER stress response that promotes apoptosis. Using human A549 and rat primary isolated alveolar type II cells, amosite asbestos fibers increased AEC mRNA and protein expression of ER stress proteins involved in the unfolded protein response, such as inositol-requiring kinase (IRE) 1 and X-box-binding protein-1, as well as ER Ca²(2+) release ,as assessed by a FURA-2 assay. Eukarion-134, a superoxide dismutase/catalase mimetic, as well as overexpression of Bcl-XL in A549 cells each attenuate asbestos-induced AEC ER stress (IRE-1 and X-box-binding protein-1 protein expression; ER Ca²(2+) release) and apoptosis. Thapsigargin, a known ER stress inducer, augments AEC apoptosis, and eukarion-134 or Bcl-XL overexpression are protective. Finally, 4-phenylbutyric acid, a chemical chaperone that attenuates ER stress, blocks asbestos- and thapsigargin-induced AEC IRE-1 protein expression, but does not reduce ER Ca²(2+) release or apoptosis. These results show that asbestos triggers an AEC ER stress response and subsequent intrinsic apoptosis that is mediated in part by ER Ca²(2+) release.

  1. Sorafenib inhibition of Mcl-1 accelerates ATRA induced apoptosis in differentiation responsive AML cells

    PubMed Central

    Wang, Rui; Xia, Lijuan; Gabrilove, Janice; Waxman, Samuel; Jing, Yongkui

    2015-01-01

    Purpose All trans retinoic acid (ATRA) is successful in treating acute promyelocytic leukemia (APL) by inducing terminal differentiation-mediated cell death, but it has limited activity in non-APL acute myeloid leukemia (AML). We aim to improve ATRA therapy of AML by enhancing apoptosis through repression of the anti-apoptotic proteins Bcl-2 and Mcl-1. Experimental Design APL and AML cell lines, as well as primary AML samples, were used to explore the mechanisms regulating differentiation and apoptosis during ATRA treatment. Stable transfection and gene silencing with siRNA were used to identify the key factors that inhibit apoptosis during induction of differentiation and drugs that accelerate apoptosis. Results In differentiation responsive AML cells, ATRA treatment induces long-lasting repression of Bcl-2 while first up-modulating and then reducing the Mcl-1 level. The Mcl-1 level appears to serve as a gatekeeper between differentiation and apoptosis. During differentiation induction, activation of MEK/ERK and PI3K/Akt pathways by ATRA leads to activation of p90RSK and inactivation of glycogen synthase kinase 3β (GSK3β), which increase Mcl-1 levels by increasing its translation and stability. Sorafenib blocks ATRA-induced Mcl-1 increase by reversing p90RSK activation and GSK3β inactivation, maintains the repressed Bcl-2 level, and enhances ATRA induced apoptosis in non-APL AML cell lines and in primary AML cells. Conclusion Inhibition of Mcl-1 is required for apoptosis induction in ATRA differentiation responsive AML cells. ATRA and Sorafenib can be developed as a novel drug combination therapy for AML patients because this drug combination augments apoptosis by inhibiting Bcl-2 and Mcl-1. PMID:26459180

  2. Arsenite-loaded nanoparticles inhibit PARP-1 to overcome multidrug resistance in hepatocellular carcinoma cells

    PubMed Central

    Liu, Hanyu; Zhang, Zongjun; Chi, Xiaoqin; Zhao, Zhenghuan; Huang, Dengtong; Jin, Jianbin; Gao, Jinhao

    2016-01-01

    Hepatocellular carcinoma (HCC) is one of the highest incidences in cancers; however, traditional chemotherapy often suffers from low efficiency caused by drug resistance. Herein, we report an arsenite-loaded dual-drug (doxorubicin and arsenic trioxide, i.e., DOX and ATO) nanomedicine system (FeAsOx@SiO2-DOX, Combo NP) with significant drug synergy and pH-triggered drug release for effective treatment of DOX resistant HCC cells (HuH-7/ADM). This nano-formulation Combo NP exhibits the synergistic effect of DNA damage by DOX along with DNA repair interference by ATO, which results in unprecedented killing efficiency on DOX resistant cancer cells. More importantly, we explored the possible mechanism is that the activity of PARP-1 is inhibited by ATO during the treatment of Combo NP, which finally induces apoptosis of HuH-7/ADM cells by poly (ADP-ribosyl) ation suppression and DNA lesions accumulation. This study provides a smart drug delivery strategy to develop a novel synergistic combination therapy for effectively overcome drug- resistant cancer cells. PMID:27484730

  3. Arsenite-loaded nanoparticles inhibit PARP-1 to overcome multidrug resistance in hepatocellular carcinoma cells

    NASA Astrophysics Data System (ADS)

    Liu, Hanyu; Zhang, Zongjun; Chi, Xiaoqin; Zhao, Zhenghuan; Huang, Dengtong; Jin, Jianbin; Gao, Jinhao

    2016-08-01

    Hepatocellular carcinoma (HCC) is one of the highest incidences in cancers; however, traditional chemotherapy often suffers from low efficiency caused by drug resistance. Herein, we report an arsenite-loaded dual-drug (doxorubicin and arsenic trioxide, i.e., DOX and ATO) nanomedicine system (FeAsOx@SiO2-DOX, Combo NP) with significant drug synergy and pH-triggered drug release for effective treatment of DOX resistant HCC cells (HuH-7/ADM). This nano-formulation Combo NP exhibits the synergistic effect of DNA damage by DOX along with DNA repair interference by ATO, which results in unprecedented killing efficiency on DOX resistant cancer cells. More importantly, we explored the possible mechanism is that the activity of PARP-1 is inhibited by ATO during the treatment of Combo NP, which finally induces apoptosis of HuH-7/ADM cells by poly (ADP-ribosyl) ation suppression and DNA lesions accumulation. This study provides a smart drug delivery strategy to develop a novel synergistic combination therapy for effectively overcome drug- resistant cancer cells.

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

    PubMed

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

    2014-01-01

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

  5. Bupivacaine induces apoptosis via mitochondria and p38 MAPK dependent pathways.

    PubMed

    Lu, Jun; Xu, Shi Yuan; Zhang, Qing Guo; Xu, Rui; Lei, Hong Yi

    2011-04-25

    Mitochondria and the p38 mitogen-activated protein kinase (MAPK) pathways play important roles in apoptosis. Although the effect of bupivacaine on apoptosis is known, it remains unclear whether bupivacaine induces apoptosis via mitochondrial depolarization and the p38 MAPK activity. In this study, SH-SY5Y cells were pretreated respectively with 50μM 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS), 10μM 4-(4-Fluorophenyl)-2-[4-(methylsulfinyl)phenyl]-5-(4-pyridyl)-1H-imidazole (SB203580), and 50μM DIDS plus 10μM SB203580 30min prior to the treatment with either 1mM bupivacaine or an equivalent amount of medium. The cell viability, mitochondrial membrane potential, phospho-p38 MAPK (p-p38 MAPK) and cell apoptosis were investigated with MTT assay, western blots, Hoechst 33258 staining and flow cytometry assay. In addition, the roles of chloridion (Cl(-)) channel and reactive oxygen species were studied to explore the molecular mechanism of bupivacaine-induced mitochondrial injury. Pretreatment with DIDS could attenuate reactive oxygen species production, the phosphorylation of p38MAPK, dissipation of mitochondrial membrane potential and apoptosis of SH-SY5Y cells induced by bupivacaine. Pretreatment with SB203580 could attenuate apoptosis, but could not attenuate reactive oxygen species production, or dissipation of mitochondrial membrane potential induced by bupivacaine. These findings indicate that the mitochondrial anion channel and p38 MAPK pathway are implicated in bupicavaine-induced apoptosis. Bupivacaine-induced reactive oxygen species production results in an alteration in the permeability of the mitochondrial membranes and Cl(-) influx into mitochondria, which seems to be responsible for mitochondrial depolarization and the p38 MAPK activation.

  6. Myosin IIA-related Actomyosin Contractility Mediates Oxidative Stress-induced Neuronal Apoptosis

    PubMed Central

    Wang, Yan; Xu, Yingqiong; Liu, Qian; Zhang, Yuanyuan; Gao, Zhen; Yin, Mingzhu; Jiang, Nan; Cao, Guosheng; Yu, Boyang; Cao, Zhengyu; Kou, Junping

    2017-01-01

    Oxidative stress-induced neuronal apoptosis plays an important role in the progression of central nervous system (CNS) diseases. In our study, when neuronal cells were exposed to hydrogen peroxide (H2O2), an exogenous oxidant, cell apoptosis was observed with typical morphological changes including membrane blebbing, neurite retraction and cell contraction. The actomyosin system is considered to be responsible for the morphological changes, but how exactly it regulates oxidative stress-induced neuronal apoptosis and the distinctive functions of different myosin II isoforms remain unclear. We demonstrate that myosin IIA was required for neuronal contraction, while myosin IIB was required for neuronal outgrowth in normal conditions. During H2O2-induced neuronal apoptosis, myosin IIA, rather than IIB, interacted with actin filaments to generate contractile forces that lead to morphological changes. Moreover, myosin IIA knockout using clustered regularly interspaced short palindromic repeats/CRISPR-associated protein-9 nuclease (CRISPR/Cas9) reduced H2O2-induced neuronal apoptosis and the associated morphological changes. We further demonstrate that caspase-3/Rho-associated kinase 1 (ROCK1) dependent phosphorylation of myosin light chain (MLC) was required for the formation of the myosin IIA-actin complex. Meanwhile, either inhibition of myosin II ATPase with blebbistatin or knockdown of myosin IIA with siRNA reversely attenuated caspase-3 activation, suggesting a positive feedback loop during oxidative stress-induced apoptosis. Based on our observation, myosin IIA-actin complex contributes to actomyosin contractility and is associated with the positive feedback loop of caspase-3/ROCK1/MLC pathway. This study unravels the biochemical and mechanistic mechanisms during oxidative stress-induced neuronal apoptosis and may be applicable for the development of therapies for CNS diseases. PMID:28352215

  7. Crimean-Congo Hemorrhagic Fever Virus-Infected Hepatocytes Induce ER-Stress and Apoptosis Crosstalk

    PubMed Central

    Rodrigues, Raquel; Paranhos-Baccalà, Gláucia; Vernet, Guy; Peyrefitte, Christophe N.

    2012-01-01

    Crimean-Congo hemorrhagic fever virus (CCHFV) is a widely distributed tick-borne member of the Nairovirus genus (Bunyaviridae) with a high mortality rate in humans. CCHFV induces a severe disease in infected patients that includes, among other symptoms, massive liver necrosis and failure. The interaction between liver cells and CCHFV is therefore important for understanding the pathogenesis of this disease. Here, we described the in vitro CCHFV-infection and -replication in the hepatocyte cell line, Huh7, and the induced cellular and molecular response modulation. We found that CCHFV was able to infect and replicate to high titres and to induce a cytopathic effect (CPE). We also observed by flow cytometry and real time quantitative RT-PCR evidence of apoptosis, with the participation of the mitochondrial pathway. On the other hand, we showed that the replication of CCHFV in hepatocytes was able to interfere with the death receptor pathway of apoptosis. Furthermore, we found in CCHFV-infected cells the over-expression of PUMA, Noxa and CHOP suggesting the crosstalk between the ER-stress and mitochondrial apoptosis. By ELISA, we observed an increase of IL-8 in response to viral replication; however apoptosis was shown to be independent from IL-8 secretion. When we compared the induced cellular response between CCHFV and DUGV, a mild or non-pathogenic Nairovirus for humans, we found that the most striking difference was the absence of CPE and apoptosis. Despite the XBP1 splicing and PERK gene expression induced by DUGV, no ER-stress and apoptosis crosstalk was observed. Overall, these results suggest that CCHFV is able to induce ER-stress, activate inflammatory mediators and modulate both mitochondrial and death receptor pathways of apoptosis in hepatocyte cells, which may, in part, explain the role of the liver in the pathogenesis of CCHFV. PMID:22238639

  8. The effects of humanin and its analogues on male germ cell apoptosis induced by chemotherapeutic drugs.

    PubMed

    Jia, Yue; Ohanyan, Aikoui; Lue, Yan-He; Swerdloff, Ronald S; Liu, Peter Y; Cohen, Pinchas; Wang, Christina

    2015-04-01

    Human (HN) prevents stress-induced apoptosis in many cells/tissues. In this study we showed that HN ameliorated chemotherapy [cyclophosphamide (CP) and Doxorubicin (DOX)]-induced male germ cell apoptosis both ex vivo in seminiferous tubule cultures and in vivo in the testis. HN acts by several putative mechanisms via binding to: an IL-12 like trimeric membrane receptor; BAX; or insulin-like growth factor binding protein-3 (IGFBP-3, a proapoptotic factor). To understand the mechanisms of HN on male germ cell apoptosis, we studied five HN analogues including: HNG (HN-S14G, a potent agonist), HNG-F6A (no binding to IGFBP-3), HN-S7A (no self-dimerization), HN-C8P (no binding to BAX), and HN-L12A (a HN antagonist) on CP-induced male germ cell apoptosis in mice. CP-induced germ cell apoptosis was inhibited by HN, HNG, HNG-F6A, HN-S7A, and HN-C8P (less effective); but not by HN-L12A. HN-L12A, but not HN-S7A or HN-C8P, blocked the protective effect of HN against CP-induced male germ cell apoptosis. HN, HN-S7A, and HN-C8P restored CP-suppressed STAT3 phosphorylation. These results suggest that HN: (1) decreases DOX (ex vivo) and CP (in vivo) induced male germ cell apoptosis; (2) action is mediated by the membrane receptor/STAT3 with minor contribution by BAX-binding pathway; (3) self-dimerization or binding to IGFBP-3 may not be involved in HN's effect in testis. HN is an important molecule in the regulation of germ cell homeostasis after injury and agonistic analogues may be developed for treating male infertility or protection against chemotherapy side effects.

  9. Nitrous oxide plus isoflurane induces apoptosis and increases β-amyloid protein levels

    PubMed Central

    Zhen, Yu; Dong, Yuanlin; Wu, Xu; Xu, Zhipeng; Lu, Yan; Zhang, Yiying; Norton, David; Tian, Ming; Li, Shuren; Xie, Zhongcong

    2009-01-01

    Background Some anesthetics have been suggested to induce neurotoxicity including promotion of Alzheimer’s disease neuropathogenesis. Nitrous oxide and isoflurane are common anesthetics. Here, we set out to assess effects of nitrous oxide and/or isoflurane on apoptosis and β-amyloid (Aβ) levels in H4 human neuroglioma cells and primary neurons from naïve mice. Methods The cells or neurons were exposed to 70% nitrous oxide and/or 1% isoflurane for six hours. The cells or neurons and conditioned media were harvested at the end of the treatment. Caspase-3 activation, apoptosis, processing of amyloid precursor protein, and Aβ levels were determined. Results Treatment with a combination of 70% nitrous oxide and 1% isoflurane for six hours induced caspase-3 activation and apoptosis in H4 naïve cells and primary neurons from naïve mice. The 70% nitrous oxide plus 1% isoflurane, but neither alone, for six hours induced caspase-3 activation and apoptosis, and increased levels of β-site amyloid precursor protein-cleaving enzyme and Aβ in H4-amyloid precursor protein cells. In addition, the nitrous oxide plus isoflurane-induced Aβ generation was reduced by a broad caspase inhibitor Z-VAD. Finally, the nitrous oxide plus isoflurane-induced caspase-3 activation was attenuated by γ-secretase inhibitor L-685,458, but potentiated by exogenously added Aβ. Conclusion These results suggest that common anesthetics nitrous oxide plus isoflurane may promote neurotoxicity by inducing apoptosis and increasing Aβ levels. The generated Aβ may further potentiate apoptosis to form another round of apoptosis and Aβ generation. More studies, especially the in vivo confirmation of these in vitro findings, are needed. PMID:19741497

  10. The Effects of Humanin and Its Analogues on Male Germ Cell Apoptosis Induced by Chemotherapeutic Drugs

    PubMed Central

    Jia, Yue; Ohanyan, Aikoui; Lue, Yan-He; Swerdloff, Ronald S.; Liu, Peter Y.; Cohen, Pinchas; Wang, Christina

    2015-01-01

    Human (HN) prevents stress-induced apoptosis in many cells/tissues. In this study we showed that HN ameliorated chemotherapy (Cyclophosphamide, CP and Doxorubicin, DOX)-induced male germ cell apoptosis both ex vivo in seminiferous tubule cultures and in vivo in the testis. HN acts by several putative mechanisms via binding to: an IL-12 like trimeric membrane receptor; BAX; or Insulin-Like Growth Factor Binding Protein-3 (IGFBP-3, a proapoptotic factor). To understand the mechanisms of HN on male germ cell apoptosis, we studied five HN analogues including: HNG (HN-S14G, a potent agonist), HNG-F6A (no binding to IGFBP-3), HN-S7A (no self-dimerization), HN-C8P (no binding to BAX), and HN-L12A (a HN antagonist) on CP-induced male germ cell apoptosis in mice. CP-induced germ cell apoptosis was inhibited by HN, HNG, HNG-F6A, HN-S7A, and HN-C8P (less effective); but not by HN-L12A. HN-L12A, but not HN-S7A or HN-C8P, blocked the protective effect of HN against CP-induced male germ cell apoptosis. HN, HN-S7A, and HN-C8P restored CP-suppressed STAT3 phosphorylation. These results suggest that HN: 1) decreases DOX (ex vivo) and CP (in vivo) induced male germ cell apoptosis; 2) action is mediated by the membrane receptor/STAT3 with minor contribution by BAX-binding pathway; 3) self-dimerization or binding to IGFBP-3 may not be involved in HN’s effect in testis. HN is an important molecule in the regulation of germ cell homeostasis after injury and agonistic analogues may be developed for treating male infertility or protection against chemotherapy side effects. PMID:25666707

  11. NFAT2 mediates high glucose-induced glomerular podocyte apoptosis through increased Bax expression

    SciTech Connect

    Li, Ruizhao; Zhang, Li; Shi, Wei; Zhang, Bin; Liang, Xinling; Liu, Shuangxin; Wang, Wenjian

    2013-04-15

    Background: Hyperglycemia promotes podocyte apoptosis and plays a key role in the pathogenesis of diabetic nephropathy. However, the mechanisms that mediate hyperglycemia-induced podocyte apoptosis is still far from being fully understood. Recent studies reported that high glucose activate nuclear factor of activated T cells (NFAT) in vascular smooth muscle or pancreatic β-cells. Here, we sought to determine if hyperglycemia activates NFAT2 in cultured podocyte and whether this leads to podocyte apoptosis. Meanwhile, we also further explore the mechanisms of NFAT2 activation and NFAT2 mediates high glucose-induced podocyte apoptosis. Methods: Immortalized mouse podocytes were cultured in media containing normal glucose (NG), or high glucose (HG) or HG plus cyclosporine A (a pharmacological inhibitor of calcinerin) or 11R-VIVIT (a special inhibitor of NFAT2). The activation of NFAT2 in podocytes was detected by western blotting and immunofluorescence assay. The role of NFAT2 in hyperglycemia-induced podocyte apoptosis was further evaluated by observing the inhibition of NFAT2 activation by 11R-VIVIT using flow cytometer. Intracellular Ca{sup 2+} was monitored in HG-treated podcocytes using Fluo-3/AM. The mRNA and protein expression of apoptosis gene Bax were measured by real time-qPCR and western blotting. Results: HG stimulation activated NFAT2 in a time- and dose-dependent manner in cultured podocytes. Pretreatment with cyclosporine A (500 nM) or 11R-VIVIT (100 nM) completely blocked NFAT2 nuclear accumulation. Meanwhile, the apoptosis effects induced by HG were also abrogated by concomitant treatment with 11R-VIVIT in cultured podocytes. We further found that HG also increased [Ca{sup 2+}]i, leading to activation of calcineurin, and subsequent increased nuclear accumulation of NFAT2 and Bax expression in cultured podocytes. Conclusion: Our results identify a new finding that HG-induced podocyte apoptosis is mediated by calcineurin/NFAT2/Bax signaling pathway

  12. Methamphetamine-induced neuronal apoptosis involves the activation of multiple death pathways. Review.

    PubMed

    Cadet, Jean Lud; Jayanthi, Subramaniam; Deng, Xiaolin

    2005-11-01

    The abuse of the illicit drug methamphetamine (METH) is a major concern because it can cause terminal degeneration and neuronal cell death in the brain. METH-induced cell death occurs via processes that resemble apoptosis. In the present review, we discuss the role of various apoptotic events in the causation of METH-induced neuronal apoptosis in vitro and in vivo. Studies using comprehensive approaches to gene expression profiling have allowed for the identification of several genes that are up-regulated or down-regulated after an apoptosis-inducing dose of the drug. Further experiments have also documented the fact that the drug can cause demise of striatal enkephalinergic neurons by cross-talks between mitochondria-, endoplasmic reticulum- and receptor-mediated apoptotic events. These neuropathological observations have also been reported in models of drug-induced neuroplastic alterations used to mimic drug addiction (Nestler, 2001).

  13. Exopolysaccharide from Trichoderma pseudokoningii induces the apoptosis of MCF-7 cells through an intrinsic mitochondrial pathway.

    PubMed

    Wang, Guodong; Liu, Chunyan; Liu, Jun; Liu, Bo; Li, Ping; Qin, Guozheng; Xu, Yanghui; Chen, Ke; Liu, Huixia; Chen, Kaoshan

    2016-01-20

    In this study, we reported the anticancer efficacy of exopolysaccharide (EPS) derived from Trichoderma pseudokoningii, on human breast cancer MCF-7 cells. Our results showed that EPS inhibited the proliferation of MCF-7 cells and induced lactic dehydrogenase release by inducing apoptosis and cell arrest at S phase. Further study revealed that EPS-induced apoptosis of MCF-7 cells was associated with alteration of nuclear morphology, disruption of mitochondrial membrane potential and accumulation of intracellular reactive oxygen species. Sequentially, EPS increased the activation of caspase-9 and caspase-3 in a dose-dependent manner; however, caspase-8 remained intact. Western blot analysis revealed that EPS increased the ratio of Bax/Bcl-2 and promoted the release of cytochrome c into the cytoplasm. Taken together, these findings provided evidence that EPS induced the apoptosis of MCF-7 cells through an intrinsic mitochondrial apoptotic pathway and that EPS may therefore be considered as an effective adjuvant agent against human breast cancer.

  14. XPB Induces C1D Expression to Counteract UV-Induced Apoptosis

    PubMed Central

    Li, Guang; Liu, Juhong; Abu-Asab, Mones; Masabumi, Shibuya; Maru, Yoshiro

    2010-01-01

    Although C1D has been shown to be involved in DNA double-strand breaks repair, how C1D expression was induced and the mechanism(s) by which C1D facilitates DNA repair in mammalian cells remain poorly understood. We and others have previously shown that expression of XPB protein efficiently compensated the UV-irradiation sensitive phenotype of 27-1 cells which lacks functional XPB. To further explore XPB-regulated genes that could be involved in UV-induced DNA repair, Differential Display analysis of mRNA level from CHO-9, 27-1 and 27-1 complemented with wild-type XPB were performed and C1D gene was identified as one of the major genes whose expression was significantly up-regulated by restoring XPB function. We found that XPB is essential to induce C1D transcription after UV-irradiation. The increase of C1D expression effectively compensates the UV-induced proteolysis of C1D and thus maintains cellular C1D level to cope with DNA damage inflicted by UV-irradiation. We further showed that although insufficient to rescue 27-1 cells from UV-induced apoptosis by itself, C1D facilitates XPB DNA repair through direct interaction with XPB. Our findings provided direct evidence that C1D is associated with DNA repair complex and may promote repair of UV-induced DNA damage. PMID:20530579

  15. Intracellular mechanisms mediating tocotrienol-induced apoptosis in neoplastic mammary epithelial cells.

    PubMed

    Sylvester, Paul W; Shah, Sumit

    2005-01-01

    Tocotrienols and tocopherols represent the two subgroups that make up the vitamin E family of compounds. However, tocotrienols display significantly more potent apoptotic activity in neoplastic mammary epithelial cells than tocopherols. Studies were conducted to determine the intracellular mechanism(s) mediating tocotrienol-induced apoptosis in neoplastic +SA mouse mammary epithelial cells in vitro. An initial step in apoptosis is the activation of 'initiator' caspases (caspase-8 or -9) that subsequently activate 'effector' caspases (caspase-3, -6 and -7) and induce apoptosis. Treatment with cytotoxic doses of alpha-tocotrienol (20 microM) resulted in a time-dependent increase in caspase-8 and caspase-3 activity. Combined treatment with specific caspase-8 or caspase-3 inhibitors completely blocked alpha-tocotrienol-induced apoptosis and caspase-8 or caspase-3 activity, respectively. In contrast, alpha-tocotrienol treatment had no effect on caspase-9 activation, and combined treatment with a specific caspase-9 inhibitor did not block alpha-tocotrienol-induced apoptosis in (+)SA cells. Since caspase-8 activation is associated with the activation of death receptors, such as Fas, tumor necrosis factor (TNF), or TNF-related apoptosis-inducing ligand (TRAIL) receptors, studies were conducted to determine the exact death receptor(s) and ligand(s) involved in mediating tocotrienol-induced caspase-8 activation and apoptosis. Treatment with Fas-ligand (FasL), Fas-activating antibody, or TRAIL failed to induce cell death in (+)SA neoplastic mammary epithelial cells, suggesting that these cells are resistant to death receptor-induced apoptosis. Moreover, treatment with cytotoxic doses of alpha-tocotrienol did not alter the intracellular levels of Fas, FasL, or Fas-associated death domain (FADD) in these cells. Western blot analysis also showed that alpha-tocotrienol did not induce FasL or FADD translocation from the cytosolic to membrane fraction in these cells. Finally

  16. Vascular smooth muscle cell apoptosis promotes transplant arteriosclerosis through inducing the production of SDF-1α.

    PubMed

    Li, J; Liu, S; Li, W; Hu, S; Xiong, J; Shu, X; Hu, Q; Zheng, Q; Song, Z

    2012-08-01

    Transplant arteriosclerosis is a leading cause of late allograft loss. Medial smooth muscle cell (SMC) apoptosis is considered to be an important event in transplant arteriosclerosis. However, the precise contribution of medial SMC apoptosis to transplant arteriosclerosis and the underlying mechanisms remain unclear. We transferred wild-type p53 to induce apoptosis of cultured SMCs. We found that apoptosis induces the production of SDF-1α from apoptotic and neighboring viable cells, resulting in increased SDF-1α in the culture media. Conditioned media from Ltv-p53-transferred SMCs activated PI3K/Akt/mTOR and MAPK/Erk signaling in a SDF-1α-dependent manner and thereby promoted mesenchymal stem cell (MSC) migration and proliferation. In a rat aorta transplantation model, lentivirus-mediated BclxL transfer selectively inhibits medial SMC apoptosis in aortic allografts, resulting in a remarkable decrease of SDF-1α both in allograft media and in blood plasma, associated with diminished recruitment of CD90(+)CD105(+) double-positive cells and impaired neointimal formation. Systemic administration of rapamycin or PD98059 also attenuated MSC recruitment and neointimal formation in the aortic allografts. These results suggest that medial SMC apoptosis is critical for the development of transplant arteriosclerosis through inducing SDF-1α production and that MSC recruitment represents a major component of vascular remodeling, constituting a relevant target and mechanism for therapeutic interventions.

  17. Cocaine induces apoptosis in cerebral vascular muscle cells: potential roles in strokes and brain damage.

    PubMed

    Su, Jialin; Li, Jianfeng; Li, Wenyan; Altura, Bella T; Altura, Burton M

    2003-12-15

    Cocaine abuse is known to induce different types of brain-microvascular damage and many adverse cerebrovascular effects, including cerebral vasculitis, intracranial hemorrhage, cerebral infarction and stroke. A major physiological event leading to these pathophysiological actions of cocaine could be apoptosis. Whether cocaine can cause brain-microvascular pathology and vascular toxicity by inducing apoptosis of cerebral vascular smooth muscle cells is not known. This study, using several different methods to discern apoptosis, was designed to investigate if primary cultured canine cerebral vascular smooth muscle cells can undergo apoptosis when treated with cocaine. After treatment with cocaine (10(-6)-10(-3) M) for 12-24 h, the death rates of cerebral vascular smooth muscle cells increased in a concentration-dependent manner compared with controls. Morphological analysis of cerebral vascular smooth muscle cells using confocal fluoresence microscopy showed that the percentage of apoptotic cerebral vascular smooth muscle cells increased after cocaine (10(-6)-10(-3) M) treatment in a concentration-dependent manner. TUNEL assays also showed positive results for cerebral vascular smooth muscle cells treated with cocaine. These results clearly demonstrate that cerebral vascular smooth muscle cells can undergo rapid apoptosis in response to cocaine in a concentration-dependent manner. Cocaine-induced apoptosis may thus play a major role in brain-microvascular damage, cerebral vascular toxicity and strokes.

  18. Targeting the metabolic pathway of human colon cancer overcomes resistance to TRAIL-induced apoptosis.

    PubMed

    Carr, Ryan M; Qiao, Guilin; Qin, Jianzhong; Jayaraman, Sundararajan; Prabhakar, Bellur S; Maker, Ajay V

    2016-01-01

    Colon cancer is a leading cause of cancer-related mortality for which targeted therapy is needed; however, trials using apoptosis-inducing ligand monotherapy to overcome resistance to apoptosis have not shown clinical responses. Since colon cancer cells selectively uptake and rapidly metabolize glucose, a property utilized for clinical staging, we investigated mechanisms to alter glucose metabolism in order to selectively target the cancer cells and to overcome evasion of apoptosis. We demonstrate TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) resistance in the majority of human colon cancers tested and utilize the glucose analog 2-deoxy-d-glucose to sensitize TRAIL-resistant gastrointestinal adenocarcinoma cells, and not normal gastrointestinal epithelial cells, to TRAIL-induced apoptosis through enhanced death receptor 5 expression, downstream modulation of MAPK signaling and subsequent miRNA expression modulation by increasing the expression of miR-494 via MEK activation. Further, established human colon cancer xenografts treated with this strategy experience anti-tumor responses. These findings in colon adenocarcinoma support further investigation of manipulation of cellular energetics to selectively overcome resistance to apoptosis and to impart tumor regressions in established colon cancer tumors.

  19. Caffeic acid phenethyl ester induces mitochondria-mediated apoptosis in human myeloid leukemia U937 cells.

    PubMed

    Jin, Un-Ho; Song, Kwon-Ho; Motomura, Muneo; Suzuki, Ikukatsu; Gu, Yeun-Hwa; Kang, Yun-Jeong; Moon, Tae-Chul; Kim, Cheorl-Ho

    2008-03-01

    Caffeic acid phenyl ester (CAPE), a biologically active ingredient of propolis, has several interesting biological properties including antioxidant, anti-inflammatory, antiviral, immunostimulatory, anti-angiogenic, anti-invasive, anti-metastatic and carcinostatic activities. Recently, several groups have reported that CAPE is cytotoxic to tumor cells but not to normal cells. In this study, we investigated the mechanism of CAPE-induced apoptosis in human myeloid leukemia U937 cells. Treatment of U937 cells with CAPE decreased cell viability in a dose-dependent and time-dependent manner. DNA fragmentation assay revealed the typical ladder profile of oligonucleosomal fragments in CAPE-treated U937 cells. In addition, as evidenced by the nuclear DAPI staining experiment, we observed that the nuclear condensation, a typical phenotype of apoptosis, was found in U937 cells treated with 5 microg/ml of CAPE. Therefore, it was suggested that CAPE is a potent agent inducing apoptosis in U937 cells. Apoptotic action of the CAPE was accompanied by release of cytochrome C, reduction of Bcl-2 expression, increase of Bax expression, activation/cleavage of caspase-3 and activation/cleavage of PARP in U937 cells, but not by Fas protein, an initial mediator in the death signaling, or by phospho-eIF2 alpha and CHOP, crucial mediators in ER-mediated apoptosis. From the results, it was concluded that CAPE induces the mitochondria-mediated apoptosis but not death receptors- or ER-mediated apoptosis in U937 cells.

  20. Targeting the metabolic pathway of human colon cancer overcomes resistance to TRAIL-induced apoptosis

    PubMed Central

    Carr, Ryan M; Qiao, Guilin; Qin, Jianzhong; Jayaraman, Sundararajan; Prabhakar, Bellur S; Maker, Ajay V

    2016-01-01

    Colon cancer is a leading cause of cancer-related mortality for which targeted therapy is needed; however, trials using apoptosis-inducing ligand monotherapy to overcome resistance to apoptosis have not shown clinical responses. Since colon cancer cells selectively uptake and rapidly metabolize glucose, a property utilized for clinical staging, we investigated mechanisms to alter glucose metabolism in order to selectively target the cancer cells and to overcome evasion of apoptosis. We demonstrate TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) resistance in the majority of human colon cancers tested and utilize the glucose analog 2-deoxy-d-glucose to sensitize TRAIL-resistant gastrointestinal adenocarcinoma cells, and not normal gastrointestinal epithelial cells, to TRAIL-induced apoptosis through enhanced death receptor 5 expression, downstream modulation of MAPK signaling and subsequent miRNA expression modulation by increasing the expression of miR-494 via MEK activation. Further, established human colon cancer xenografts treated with this strategy experience anti-tumor responses. These findings in colon adenocarcinoma support further investigation of manipulation of cellular energetics to selectively overcome resistance to apoptosis and to impart tumor regressions in established colon cancer tumors. PMID:27648301

  1. Low-power laser irradiation inhibits Aβ25-35-induced cell apoptosis through Akt activation

    NASA Astrophysics Data System (ADS)

    Zhang, Zhigang; Tang, Yonghong

    2009-08-01

    Low-power laser irradiation (LPLI) can modulate various cellular processes such as proliferation, differentiation and apoptosis. Recently, LPLI has been applied to moderate Alzheimer's disease (AD), but the underlying mechanism remains unknown. The protective role of LPLI against the amyloid beta peptide (Aβ), a major constituent of AD plaques, has not been studied. PI3K/Akt pathway is extremely important in protecting cells from apoptosis caused by diverse stress stimuli. However, whether LPLI can inhibit Aβ-induced apoptosis through Akt activation is still unclear. In current study, using FRET (fluorescence resonance energy transfer) technique, we investigated the activity of Akt in response to LPLI treatment. B kinase activity reporter (BKAR), a recombinant FRET probe of Akt, was utilized to dynamically detect the activation of Akt after LPLI treatment. The results show that LPLI promoted the activation of Akt. Moreover, LPLI inhibits apoptosis induced by Aβ25-35 and the apoptosis inhibition can be abolished by wortmannin, a specific inhibitor of PI3K/Akt. Taken together, these results suggest that LPLI can inhibit Aβ25-35-induced cell apoptosis through Akt activation.

  2. Apigenin induces the apoptosis and regulates MAPK signaling pathways in mouse macrophage ANA-1 cells.

    PubMed

    Liao, Yuexia; Shen, Weigan; Kong, Guimei; Lv, Houning; Tao, Wenhua; Bo, Ping

    2014-01-01

    Apigenin is a naturally occurring plant flavonoid that possesses antioxidant, anti-cancer and anti-inflammatory properties. However, there are few reports has been done on the ability of apigenin to induce apoptosis in macrophages. In this study, mouse macrophage ANA-1 cells were incubated with different concentrations of apigenin. The cell viability was determined by an MTT assay. The cell apoptosis were analyzed by flow cytometric analysis. Apoptosis were also analyzed using a TUNEL assay and a DNA ladder. The level of intracellular ROS was detected using a dichlorofluorescein -diacetate probe. The expression levels of apoptosis-related proteins were detected by western blot analysis. The results showed that apigenin decreased the viability of ANA-1 cells and induced apoptosis in a dose- and time-dependent manner. Apigenin increased the level of intracellular ROS, downregulated the expression of Bcl-2 and upregulated the expression of caspase-3 and caspase-8 in ANA-1 cells. Furthermore, apigenin downregulated the expression of phospho-ERK and phospho-JNK, upregulated the expression of phospho-p38 and had no significant effect on the expression of Bax, ERK, JNK and p38. The results suggested that apigenin induced cell apoptosis in mouse macrophage ANA-1 cells may via increasing intracellular ROS, regulating the MAPK pathway, and then inhibiting Bcl-2 expression.

  3. Carbon nanotubes induce apoptosis resistance of human lung epithelial cells through FLICE-inhibitory protein.

    PubMed

    Pongrakhananon, Varisa; Luanpitpong, Sudjit; Stueckle, Todd A; Wang, Liying; Nimmannit, Ubonthip; Rojanasakul, Yon

    2015-02-01

    Chronic exposure to single-walled carbon nanotubes (SWCNT) has been reported to induce apoptosis resistance of human lung epithelial cells. As resistance to apoptosis is a foundation of neoplastic transformation and cancer development, we evaluated the apoptosis resistance characteristic of the exposed lung cells to understand the pathogenesis mechanism. Passage control and SWCNT-transformed human lung epithelial cells were treated with known inducers of apoptosis via the intrinsic (antimycin A and CDDP) or extrinsic (FasL and TNF-α) pathway and analyzed for apoptosis by DNA fragmentation, annexin-V expression, and caspase activation assays. Whole-genome microarray was performed to aid the analysis of apoptotic gene signaling network. The SWCNT-transformed cells exhibited defective death receptor pathway in association with cellular FLICE-inhibitory protein (c-FLIP) overexpression. Knockdown or chemical inhibition of c-FLIP abrogated the apoptosis resistance of SWCNT-transformed cells. Whole-genome expression signature analysis confirmed these findings. This study is the first to demonstrate carbon nanotube-induced defective death receptor pathway and the role of c-FLIP in the process.

  4. Apoptosis of human gastric carcinoma cells induced by Euphorbia esula latex

    PubMed Central

    Fu, Zhao-Ying; Han, Xiao-Dong; Wang, Ai-Hong; Liu, Xiao-Bin

    2016-01-01

    AIM: To investigate the effect of Euphorbia esula (E. esula) extract in inhibiting proliferation and inducing apoptosis in SGC-7901 cells. METHODS: E. esula extract at different concentrations was used to inhibit proliferation and induce apoptosis of human gastric carcinoma SGC-7901 cells. Inhibition of proliferation was detected with thiazolyl blue assay, and apoptosis was detected with fluorescence microscopy, transmission electron microscopy, and flow cytometry. The mechanisms were studied by measurement of caspase-3 and caspase-8 activities and Bax and Bcl2 mRNA expression. RESULTS: The thiazolyl blue assay showed that SGC-7901 cell viability and proliferation were inhibited significantly by E. esula extract in a time- and concentration-dependent manner. Fluorescence microscopy revealed that the cell nuclei showed the characteristic changes of apoptosis, such as uneven staining and chromatin marginalization. Some key features of apoptosis were also observed under transmission electron microscopy, which included cellular shrinkage and the foaming or bubbling phenomenon. When the cells were analyzed by flow cytometry, a sub-G1 peak could be seen clearly. Spectrophotometric assay of caspase-3 and caspase-8 activities in the treated cells showed an approximately two-fold increase. Reverse transcription polymerase chain reaction showed that Bax mRNA expression was upregulated, while Bcl2 mRNA expression was downregulated. CONCLUSION: E. esula extract inhibited proliferation and induced apoptosis in SGC-7901 cells, in a caspase-dependent manner, involving upregulation of Bax and downregulation of Bcl2. PMID:27053848

  5. [Apoptosis-inducing properties of ent-kaurene-type diterpenoids from the liverwort Jungermannia truncata].

    PubMed

    Nagashima, Fumihiro; Kondoh, Masuo; Kawase, Masaki; Simizu, Siro; Osada, Hiroyuki; Fujii, Makiko; Watanabe, Yoshiteru; Sato, Masao; Asakawa, Yoshinori

    2003-04-01

    Ent-11alpha-hydroxy-16-kauren-15-one (1) induced apoptosis in a human leukemia cell line (HL-60 cells), however, the apoptosis-inducing properties of 1 and its related compounds remain to be proved. We examined the involvement of caspases, a family of cysteine aspartic proteases, which play a central role in induction of apoptosis, in apoptosis induced by the compounds in HL-60 cells. Treatment of the cells with compounds 1, 2 and 3 with the enone group at C-15/C-16 caused DNA fragmentation, a sign of induction of apoptosis, and proteolysis of poly(ADP-ribose) polymerase (PARP), a hallmark of caspase activation. Z-Asp-CH2-DCB, abroad spectrum inhibitor of caspases, abolished the appearance of DNA fragmentation and also significantly attenuated the cytotoxic effects. These data suggest that induction of apoptosis by 1 and some of its related compounds are dependent on caspases activation and might be partly involved in the cytotoxicity in HL-60 cells.

  6. O-GlcNAcylation regulates ischemia-induced neuronal apoptosis through AKT signaling

    PubMed Central

    Shi, Jianhua; Gu, Jin-hua; Dai, Chun-ling; Gu, Jianlan; Jin, Xiaoxia; Sun, Jianming; Iqbal, Khalid; Liu, Fei; Gong, Cheng-Xin

    2015-01-01

    Apoptosis plays an important role in neural development and neurological disorders. In this study, we found that O-GlcNAcylation, a unique protein posttranslational modification with O-linked β-N-acetylglucosamine (GlcNAc), promoted apoptosis through attenuating phosphorylation/activation of AKT and Bad. By using co-immunoprecipitation and mutagenesis techniques, we identified O-GlcNAc modification at both Thr308 and Ser473 of AKT. O-GlcNAcylation-induced apoptosis was attenuated by over-expression of AKT. We also found a dynamic elevation of protein O-GlcNAcylation during the first four hours of cerebral ischemia, followed by continuous decline after middle cerebral artery occlusion (MCAO) in the mouse brain. The elevation of O-GlcNAcylation coincided with activation of cell apoptosis. Finally, we found a negative correlation between AKT phosphorylation and O-GlcNAcylation in ischemic brain tissue. These results indicate that cerebral ischemia induces a rapid increase of O-GlcNAcylation that promotes apoptosis through down-regulation of AKT activity. These findings provide a novel mechanism through which O-GlcNAcylation regulates ischemia-induced neuronal apoptosis through AKT signaling. PMID:26412745

  7. The Mitochondrial Fission Protein hFis1 Requires the Endoplasmic Reticulum Gateway to Induce Apoptosis

    PubMed Central

    Alirol, Emilie; James, Dominic; Huber, Denise; Marchetto, Andrea; Vergani, Lodovica

    2006-01-01

    Mitochondrial fission ensures organelle inheritance during cell division and participates in apoptosis. The fission protein hFis1 triggers caspase-dependent cell death, by causing the release of cytochrome c from mitochondria. Here we show that mitochondrial fission induced by hFis1 is genetically distinct from apoptosis. In cells lacking the multidomain proapoptotic Bcl-2 family members Bax and Bak (DKO), hFis1 caused mitochondrial fragmentation but not organelle dysfunction and apoptosis. Similarly, a mutant in the intermembrane region of hFis1-induced fission but not cell death, further dissociating mitochondrial fragmentation from apoptosis induction. Selective correction of the endoplasmic reticulum (ER) defect of DKO cells restored killing by hFis1, indicating that death by hFis1 relies on the ER gateway of apoptosis. Consistently, hFis1 did not directly activate BAX and BAK, but induced Ca2+-dependent mitochondrial dysfunction. Thus, hFis1 is a bifunctional protein that independently regulates mitochondrial fragmentation and ER-mediated apoptosis. PMID:16914522

  8. Lycium barbarum polysaccharides protected human retinal pigment epithelial cells against oxidative stress-induced apoptosis

    PubMed Central

    Liu, Lian; Lao, Wei; Ji, Qing-Shan; Yang, Zhi-Hao; Yu, Guo-Cheng; Zhong, Jing-Xiang

    2015-01-01

    AIM To investigate the protective effect and its mechanism of lycium barbarum polysaccharides (LBP) against oxidative stress-induced apoptosis in human retinal pigment epithelial cells. METHODS ARPE-19 cells, a human retinal pigment epithelial cell lines, were exposed to different concentrations of H2O2 for 24h, then cell viability was measured by Cell Counting Kit-8 (CCK-8) assay to get the properly concentration of H2O2 which can induce half apoptosis of APRE-19. With different concentrations of LBP pretreatment, the ARPE-19 cells were then exposed to appropriate concentration of H2O2, cell apoptosis was detected by flow cytometric analysis. Expression levels of Bcl-2 and Bax were measured by real time quantitative polymerase chain reaction (RT-PCR) technique. RSULTS LBP significantly reduced the H2O2-induced ARPE-19 cells' apoptosis. LBP inhibited the H2O2-induced down-regulation of Bcl-2 and up-regulation of Bax. CONCLUSION LBP could protect ARPE-19 cells from H2O2-induced apoptosis. The Bcl-2 family had relationship with the protective effects of LBP. PMID:25709900

  9. Cadmium induces apoptosis in primary rat osteoblasts through caspase and mitogen-activated protein kinase pathways

    PubMed Central

    Zhao, Hongyan; Liu, Wei; Wang, Yi; Dai, Nannan; Gu, Jianhong; Yuan, Yan; Liu, Xuezhong; Bian, Jianchun

    2015-01-01

    Exposure to cadmium (Cd) induces apoptosis in osteoblasts (OBs); however, little information is available regarding the specific mechanisms of Cd-induced primary rat OB apoptosis. In this study, Cd reduced cell viability, damaged cell membranes and induced apoptosis in OBs. We observed decreased mitochondrial transmembrane potentials, ultrastructure collapse, enhanced caspase-3 activity, and increased concentrations of cleaved PARP, cleaved caspase-9 and cleaved caspase-3 following Cd treatment. Cd also increased the phosphorylation of p38-mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinases (ERK)1/2 and c-jun N-terminal kinase (JNK) in OBs. Pretreatment with the caspase inhibitor, N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone, ERK1/2 inhibitor (U0126), p38 inhibitor (SB203580) and JNK inhibitor (SP600125) abrogated Cd-induced cell apoptosis. Furthermore, Cd-treated OBs exhibited signs of oxidative stress protection, including increased antioxidant enzymes superoxide dismutase and glutathione reductase levels and decreased formation of reactive oxygen species. Taken together, the results of our study clarified that Cd has direct cytotoxic effects on OBs, which are mediated by caspase- and MAPK pathways in Cd-induced apoptosis of OBs. PMID:26425111

  10. Reactive oxygen species modulate Zn(2+)-induced apoptosis in cancer cells.

    PubMed

    Provinciali, Mauro; Donnini, Alessia; Argentati, Katy; Di Stasio, Grazia; Bartozzi, Beatrice; Bernardini, Giovanni

    2002-03-01

    Some recent evidence has suggested a protective role of zinc against cancer. The mechanism by which zinc exerts this action has not been defined and, in particular, it has not been clarified whether zinc may directly act on cancer cells and the molecular mechanisms involved in this effect. In this study, we examined the in vitro effect of zinc on the apoptosis of mouse TS/A mammary adenocarcinoma cells, studying the zinc-dependent modulation of the intracellular levels of reactive oxygen species (ROS) and of p53 and Fas/Fas ligand pathways. We showed that zinc concentrations ranging from 33.7 to 75 muM Zn(2+) induced apoptosis in mammary cancer cells. The apoptosis was associated with an increased production of intracellular ROS, and of p53 and Fas/Fas ligand mRNA and protein. Zn(2+) induced a faint metallothionein response in TS/A cells in comparison with mouse lymphocytes. The treatment of tumor cells with the antioxidant N-acetylcysteine was able to prevent Zn(2+)-induced apoptosis, as well as the increase of p53 and Fas ligand protein induced by zinc. The data demonstrate that zinc exerts a direct action on mammary cancer cells inducing ROS-mediated apoptosis and that the effect may be mediated by the ROS-dependent induction of p53 and Fas/Fas ligand.

  11. Morphine Protects Spinal Cord Astrocytes from Glutamate-Induced Apoptosis via Reducing Endoplasmic Reticulum Stress.

    PubMed

    Zhang, Chao; Wang, Chendan; Ren, Jianbo; Guo, Xiangjie; Yun, Keming

    2016-10-24

    Glutamate is not only a neurotransmitter but also an important neurotoxin in central nervous system (CNS). Chronic elevation of glutamate induces both neuronal and glial cell apoptosis. However, its effect on astrocytes is complex and still remains unclear. In this study, we investigated whether morphine, a common opioid ligand, could affect glutamate-induced apoptosis in astrocytes. Primary cultured astrocytes were incubated with glutamate in the presence/absence of morphine. It was found that morphine could reduce glutamate-induced apoptosis of astrocytes. Furthermore, glutamate activated Ca(2+) release, thereby inducing endoplasmic reticulum (ER) stress in astrocytes, while morphine attenuated this deleterious effect. Using siRNA to reduce the expression of κ-opioid receptor, morphine could not effectively inhibit glutamate-stimulated Ca(2+) release in astrocytes, the protective effect of morphine on glutamate-injured astrocytes was also suppressed. These results suggested that morphine could protect astrocytes from glutamate-induced apoptosis via reducing Ca(2+) overload and ER stress pathways. In conclusion, this study indicated that excitotoxicity participated in the glutamate mediated apoptosis in astrocytes, while morphine attenuated this deleterious effect via regulating Ca(2+) release and ER stress.

  12. Protective effects of catalase overexpression on UVB-induced apoptosis in normal human keratinocytes.

    PubMed

    Rezvani, Hamid Reza; Mazurier, Frédéric; Cario-André, Muriel; Pain, Catherine; Ged, Cécile; Taïeb, Alain; de Verneuil, Hubert

    2006-06-30

    UV-induced apoptosis in keratinocytes is a highly complex process in which various molecular pathways are involved. These include the extrinsic pathway via triggering of death receptors and the intrinsic pathway via DNA damage and reactive oxygen species (ROS) formation. In this study we investigated the effect of catalase and CuZn-superoxide dismutase (SOD) overexpression on apoptosis induced by UVB exposure at room temperature or 4 degrees C on normal human keratinocytes. Irradiation at low temperature reduced UV-induced apoptosis by 40% in normal keratinocytes independently of any change in p53 and with a decrease in caspase-8 activation. Catalase overexpression decreased apoptosis by 40% with a reduction of caspase-9 activation accompanied by a decrease in p53. Keeping cells at low temperature and catalase overexpression had additive effects. CuZn-SOD overexpression had no significant effect on UVB-induced apoptosis. UVB induced an increase in ROS levels at two distinct stages: immediately following irradiation and around 3 h after irradiation. Catalase overexpression inhibited only the late increase in ROS levels. We conclude that catalase overexpression has a protective role against UVB irradiation by preventing DNA damage mediated by the late ROS increase.

  13. Resveratrol-induced apoptosis in human T-cell acute lymphoblastic leukaemia MOLT-4 cells.

    PubMed

    Cecchinato, Valentina; Chiaramonte, Raffaella; Nizzardo, Monica; Cristofaro, Brunella; Basile, Andrea; Sherbet, Gajanan V; Comi, Paola

    2007-12-03

    Resveratrol (RES) is a natural occurring phytoalexin that has been shown to have chemopreventive activity. Resveratrol acts both by suppressing cell proliferation and inducing apoptosis in a variety of cancer cell lines. In this study, we show that RES induces apoptosis in MOLT-4 acute lymphoblastic leukaemia cells by modulating three different pathways that regulate cells survival and cell death. We show for the first time that RES inhibits the survival signalling pathways Notch and their down stream effector and modulates the operation of interacting signalling systems. It induces an increase in the levels of the pro-apoptotic proteins p53, its effector p21waf and Bax. We also show that RES inhibits the PI3K/Akt pathway and activates Gsk-3beta. The data presented here demonstrate unequivocally that RES induces apoptosis by inhibiting the Notch pathway and markedly influencing the operation of the interacting apoptosis pathways mediated by p53 and PI3K/Akt. These data support findings from other laboratories that have suggested the use of RES as a chemopreventive agent. Here, we have identified potential signalling pathways influenced by RES and this could lead to the identification of the targets of RES-induced apoptosis and growth control.

  14. The EEL-1 ubiquitin ligase promotes DNA damage-induced germ cell apoptosis in C. elegans

    PubMed Central

    Ross, A J; Li, M; Yu, B; Gao, M X; Derry, W B

    2011-01-01

    E3 ubiquitin ligases target a growing number of pro- and anti-apoptotic proteins, including tumour suppressor p53, caspases, and the Bcl-2 family. The core apoptosis pathway is well conserved between mammals and Caenorhabditis elegans, but the extent to which ubiquitin ligases regulate apoptotic cell death is not known. To investigate the role of E3 ligases in apoptosis, we inhibited 108 of the 165 predicted E3 ubiquitin ligase genes by RNA interference and quantified apoptosis in the C. elegans germline after genotoxic stress. From this screen, we identified the homologous to E6-associated protein C terminus-domain E3 ligase EEL-1 as a positive regulator of apoptosis. Intriguingly, the human homologue of EEL-1, Huwe1/ARF-BP1/Mule/HectH9, has been reported to possess both pro- and anti-apoptotic functions through its ability to stimulate Mcl-1 and p53 degradation, respectively. Here, we demonstrate that eel-1 is required to promote DNA damage-induced germ cell apoptosis, but does not have a role in physiological germ cell apoptosis or developmental apoptosis in somatic tissue. Furthermore, eel-1 acts in parallel to the p53-like gene cep-1 and intersects the core apoptosis pathway upstream of the Bcl-2/Mcl-1 orthologue ced-9. Although ee1-1 mutants exhibit hypersensitivity to genotoxic stress they do not appear to be defective in DNA repair, suggesting a distinct role for EEL-1 in promoting damage-induced apoptosis in the germline. PMID:21233842

  15. The EEL-1 ubiquitin ligase promotes DNA damage-induced germ cell apoptosis in C. elegans.

    PubMed

    Ross, A J; Li, M; Yu, B; Gao, M X; Derry, W B

    2011-07-01

    E3 ubiquitin ligases target a growing number of pro- and anti-apoptotic proteins, including tumour suppressor p53, caspases, and the Bcl-2 family. The core apoptosis pathway is well conserved between mammals and Caenorhabditis elegans, but the extent to which ubiquitin ligases regulate apoptotic cell death is not known. To investigate the role of E3 ligases in apoptosis, we inhibited 108 of the 165 predicted E3 ubiquitin ligase genes by RNA interference and quantified apoptosis in the C. elegans germline after genotoxic stress. From this screen, we identified the homologous to E6-associated protein C terminus-domain E3 ligase EEL-1 as a positive regulator of apoptosis. Intriguingly, the human homologue of EEL-1, Huwe1/ARF-BP1/Mule/HectH9, has been reported to possess both pro- and anti-apoptotic functions through its ability to stimulate Mcl-1 and p53 degradation, respectively. Here, we demonstrate that eel-1 is required to promote DNA damage-induced germ cell apoptosis, but does not have a role in physiological germ cell apoptosis or developmental apoptosis in somatic tissue. Furthermore, eel-1 acts in parallel to the p53-like gene cep-1 and intersects the core apoptosis pathway upstream of the Bcl-2/Mcl-1 orthologue ced-9. Although ee1-1 mutants exhibit hypersensitivity to genotoxic stress they do not appear to be defective in DNA repair, suggesting a distinct role for EEL-1 in promoting damage-induced apoptosis in the germline.

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

    PubMed

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

    2012-06-22

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

  17. Noscapine induces mitochondria-mediated apoptosis in human colon cancer cells in vivo and in vitro

    SciTech Connect

    Yang, Zi-Rong; Liu, Meng; Peng, Xiu-Lan; Lei, Xiao-Fei; Zhang, Ji-Xiang; Dong, Wei-Guo

    2012-05-11

    Highlights: Black-Right-Pointing-Pointer Noscapine inhibited cell viability of colon cancer in a time- and dose- dependent manner. Black-Right-Pointing-Pointer G{sub 2}/M phase arrest and chromatin condensation and nuclear fragmentation were induced. Black-Right-Pointing-Pointer Noscapine promoted apoptosis via mitochondrial pathways. Black-Right-Pointing-Pointer Tumorigenicity was inhibited by noscapine. -- Abstract: Noscapine, a phthalide isoquinoline alkaloid derived from opium, has been widely used as a cough suppressant for decades. Noscapine has recently been shown to potentiate the anti-cancer effects of several therapies by inducing apoptosis in various malignant cells without any detectable toxicity in cells or tissues. However, the mechanism by which noscapine induces apoptosis in colon cancer cells remains unclear. The signaling pathways by which noscapine induces apoptosis were investigated in colon cancer cell lines treated with various noscapine concentrations for 72 h, and a dose-dependent inhibition of cell viability was observed. Noscapine effectively inhibited the proliferation of LoVo cells in vitro (IC{sub 50} = 75 {mu}M). This cytotoxicity was reflected by cell cycle arrest at G{sub 2}/M and subsequent apoptosis, as indicated by increased chromatin condensation and fragmentation, the upregulation of Bax and cytochrome c (Cyt-c), the downregulation of survivin and Bcl-2, and the activation of caspase-3 and caspase-9. Moreover, in a xenograft tumor model in mice, noscapine injection clearly inhibited tumor growth via the induction of apoptosis, which was demonstrated using a TUNEL assay. These results suggest that noscapine induces apoptosis in colon cancer cells via mitochondrial pathways. Noscapine may be a safe and effective chemotherapeutic agent for the treatment of human colon cancer.

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

    PubMed

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

    2013-04-01

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

  19. Microcystin-LR induces mitochondria-mediated apoptosis in human bronchial epithelial cells

    PubMed Central

    Li, Yang; Li, Jinhui; Huang, Hui; Yang, Mingfeng; Zhuang, Donggang; Cheng, Xuemin; Zhang, Huizhen; Fu, Xiaoli

    2016-01-01

    The present study aimed to investigate the toxicity of microcystin-LR (MC-LR) and to explore the mechanism of MC-LR-induced apoptosis in human bronchial epithelial (HBE) cells. HBE cells were treated with MC-LR (1, 10, 20, 30 and 40 µg/ml) alone or with MC-LR (0, 2.5, 5 and 10 µg/ml) and Z-VAD-FMK (0, 10, 20, 40, 60, 80, 100, 120 and 140 µM), which is a caspase inhibitor, for 24 and 48 h. Cell viability was assessed via an MTT assay and the half maximal effective concentration of MC-LR was determined. The optimal concentration of Z-VAD-FMK was established as 50 µm, which was then used in the subsequent experiments. MC-LR significantly inhibited cell viability and induced apoptosis of HBE cells in a dose-dependent manner, as detected by an Annexin V/propidium iodide assay. MC-LR induced cell apoptosis, excess reactive oxygen species production and mitochondrial membrane potential collapse, upregulated Bax expression and downregulated B-cell lymphoma-2 expression in HBE cells. Moreover, western blot analysis demonstrated that MC-LR increased the activity levels of caspase-3 and caspase-9 and induced cytochrome c release into the cytoplasm, suggesting that MC-LR-induced apoptosis is associated with the mitochondrial pathway. Furthermore, pretreatment with Z-VAD-FMK reduced MC-LR-induced apoptosis by blocking caspase activation in HBE cells. Therefore, the results of the present study suggested that MC-LR is capable of significantly inhibiting the viability of HBE cells by inducing apoptosis in a mitochondria-dependent manner. The present study provides a foundation for further understanding the mechanism underlying the toxicity of MC-LR in the respiratory system. PMID:27446254

  20. ARL6IP1 mediates cisplatin-induced apoptosis in CaSki cervical cancer cells.

    PubMed

    Guo, Fengjie; Li, Yalin; Liu, Yan; Wang, Jiajia; Li, Guancheng

    2010-05-01

    Cisplatin has been shown to induce apoptosis in various types of cancer cells. Despite the great efficacy at treating certain kinds of cancers, cisplatin introduced into clinical use shows side effects and the acquisition or presence of resistance to the drug. Thus, it is important that we further understand the anti-cancer mechanism of cisplatin with the goal of enhancing its efficacy. ADP-ribosylation factor-like 6 interacting protein 1 (ARL6IP1) is an apoptotic regulator. We studied cisplatin-induced apoptosis with suppression of ARL6IP1 expression in CaSki cervical cancer cells. Exogenous expression of ARL6IP1 suppressed cisplatin-induced apoptosis in CaSki cells, and siRNA-induced silencing of ARL6IP1 triggered apoptosis in CaSki cells even in the absence of other apoptotic stimuli. Cisplatin treatment induced caspase-3, -9, p53, Bax, NF-kappaB and MAPK expression, and suppressed Bcl-2 and Bcl-xl expression, whereas cells transfected with pcDNA3.1-ARL6IP1 showed lower levels of cisplatin-induced caspase-3, -9, p53, Bax, NF-kappaB and MAPK up-regulation and higher levels of cisplatin-suppressed Bcl-2 and Bcl-xl down-regulation. These novel findings collectively suggest that ARL6IP1 may play a key role in cisplatin-induced apoptosis in CaSki cervical cancer cells by regulating the expression of apoptosis-associated proteins such as caspase-3, -9, p53, NF-kappaB, MAPK, Bcl-2, Bcl-xl, and Bax.

  1. Bisphosphonates induce apoptosis in human breast cancer cell lines

    PubMed Central

    Senaratne, S G; Pirianov, G; Mansi, J L; Arnett, T R; Colston, K W

    2000-01-01

    Breast cancer has a prodigious capacity to metastasize to bone. In women with advanced breast cancer and bone metastases, bisphosphonates reduce the incidence of hypercalcaemia and skeletal morbidity. Recent clinical findings suggest that some bisphosphonates reduce the tumour burden in bone with a consequent increase in survival, raising the possibility that bisphosphonates may have a direct effect on breast cancer cells. We have investigated the in vitro effects of bisphosphonates zoledronate, pamidronate, clodronate and EB 1053 on growth, viability and induction of apoptosis in three human breast cancer cell lines (MDA-MB-231, Hs 578T and MCF-7). Cell growth was monitored by crystal violet dye assay, and cell viability was quantitated by MTS dye reduction. Induction of apoptosis was determined by identification of morphological features of apoptosis using time-lapse videomicroscopy, identifying morphological changes in nucleis using Hoechst staining, quantitation of DNA fragmentation, level of expression of bcl-2 and bax proteins and identification of the proteolytic cleavage of Poly (ADP)-ribose polymerase (PARP). All four bisphosphonates significantly reduced cell viability in all three cell lines. Zoledronate was the most potent bisphosphonate with IC50values of 15, 20 and 3 μM respectively in MDA-MB-231, MCF-7 and Hs 578T cells. Corresponding values for pamidronate were 40, 35 and 25 μM, whereas clodronate and EB 1053 were more than two orders of magnitude less potent. An increase in the proportion of cells having morphological features characteristic of apoptosis, characteristic apoptotic changes in the nucleus, time-dependent increase in the percentage of fragmented chromosomal DNA, down-regulation in bcl-2 protein and proteolytic cleavage of PARP, all indicate that bisphosphonates have direct anti-tumour effects on human breast cancer cells. © 2000 Cancer Research Campaign PMID:10780527

  2. Early Dexamethasone Treatment Induces Placental Apoptosis in Sheep

    PubMed Central

    Meng, Wenbin; Shang, Hongkai; Li, Shaofu; Sloboda, Deborah M.; Ehrlich, Loreen; Lange, Karolin; Xu, Huaisheng; Henrich, Wolfgang; Dudenhausen, Joachim W.; Plagemann, Andreas; Newnham, John P.; Challis, John R. G.

    2015-01-01

    Glucocorticoid treatment given in late pregnancy in sheep resulted in altered placental development and function. An imbalance of placental survival and apoptotic factors resulting in an increased rate of apoptosis may be involved. We have now investigated the effects of dexamethasone (DEX) in early pregnancy on binucleate cells (BNCs), placental apoptosis, and fetal sex as a determinant of these responses. Pregnant ewes carrying singleton fetuses (n = 105) were randomized to control (n = 56, 2 mL saline/ewe) or DEX treatment (n = 49, intramuscular injections of 0.14 mg/kg ewe weight per 12 hours over 48 hours) at 40 to 41 days of gestation (dG). Placentomes were collected at 50, 100, 125, and 140 dG. At 100 dG, DEX in females reduced BNC numbers, placental antiapoptotic (proliferating cell nuclear antigen), and increased proapoptotic factors (Bax, p53), associated with a temporarily decrease in fetal growth. At 125 dG, BNC numbers and apoptotic markers were restored to normal. In males, ovine placental lactogen-protein levels after DEX were increased at 50 dG, but at 100 and 140 dG significantly decreased compared to controls. In contrast to females, these changes were independent of altered BNC numbers or apoptotic markers. Early DEX was associated with sex-specific, transient alterations in BNC numbers, which may contribute to changes in placental and fetal development. Furthermore, in females, altered placental apoptosis markers may be involved. PMID:25063551

  3. Depletion of Paraspeckle Protein 1 Enhances Methyl Methanesulfonate-Induced Apoptosis through Mitotic Catastrophe

    PubMed Central

    Gao, Xiangjing; Zhang, Guanglin; Shan, Shigang; Shang, Yunlong; Chi, Linfeng; Li, Hongjuan; Cao, Yifei; Zhu, Xinqiang; Zhang, Meibian; Yang, Jun

    2016-01-01

    Previously, we have shown that paraspeckle protein 1 (PSPC1), a protein component of paraspeckles that was involved in cisplatin-induced DNA damage response (DDR), probably functions at the G1/S checkpoint. In the current study, we further examined the role of PSPC1 in another DNA-damaging agent, methyl methanesulfonate (MMS)-induced DDR, in particular, focusing on MMS-induced apoptosis in HeLa cells. First, it was found that MMS treatment induced the expression of PSPC1. While MMS treatment alone can induce apoptosis, depletion of PSPC1 expression using siRNA significantly increased the level of apoptosis following MMS exposure. In contrast, overexpressing PSPC1 decreased the number of apoptotic cells. Interestingly, morphological observation revealed that many of the MMS-treated PSPC1-knockdown cells contained two or more nuclei, indicating the occurrence of mitotic catastrophe. Cell cycle analysis further showed that depletion of PSPC1 caused more cells entering the G2/M phase, a prerequisite of mitosis catastrophe. On the other hand, over-expressing PSPC1 led to more cells accumulating in the G1/S phase. Taken together, these observations suggest an important role for PSPC1 in MMS-induced DDR, and in particular, depletion of PSPC1 can enhance MMS-induced apoptosis through mitotic catastrophe. PMID:26785254

  4. Protective effect of oleanolic acid on oxidized-low density lipoprotein induced endothelial cell apoptosis.

    PubMed

    Cao, Jianhua; Li, Guanghui; Wang, Meizhi; Li, Hui; Han, Zhiwu

    2015-10-01

    Oleanolic acid (3β-hydroxyolean-12-en-28-oic acid, OA) is a naturally-occurring triterpenoid with various promising pharmacological properties. The present study was conducted to determine the protective effects of OA against oxidized low-density lipoprotein (ox-LDL) induced endothelial cell apoptosis and the possible underlying mechanisms. Our results showed that ox-LDL significantly decreased cell viability and induced apoptosis in human umbilical vein endothelial cells (HUVECs). OA in the co-treatment showed a protective effect against ox-LDL induced loss in cell viability and an increase in apoptosis, which was associated with the modulating effect of OA on ox-LDL induced hypoxia-inducible factor 1α(HIF-1α) expression. Moreover, our results showed that the modulating effect of OA against ox-LDL induced HIF-1α expression was obtained via inhibition of lipoprotein receptor 1 (LOX-1)/reactive oxygen species (ROS) signaling. Collectively, we suggested that the protective effect of OA against ox-LDL induced HUVEC apoptosis might, at least in part, be obtained via inhibition of the LOX-1/ROS/HIF-1α signaling pathway.

  5. Tamoxifen Attenuates Lipopolysaccharide/Galactosamine-induced Acute Liver Failure by Antagonizing Hepatic Inflammation and Apoptosis.

    PubMed

    Zhang, Peng; Zhang, Meisheng; Wan, Mengqi; Huang, Xiaoliu; Jiang, Yan; Xu, Siying; Luo, Mansheng

    2017-04-01

    Bacterial lipopolysaccharide (LPS)-induced acute liver failure (ALF) is a common severe clinical syndrome in intensive care unit. No other methods are available for its prevention apart from supportive treatment and liver transplantation. Tamoxifen (TAM) was reported to attenuate ALF induced by excessive acetaminophen, while its effect on LPS-induced ALF remained unknown. For this, in the present study, we comprehensively assessed whether TAM can attenuate ALF induced by LPS/galactosamine (GaIN). Mice were given TAM once a day for three times. Twelve hours after the last treatment, mice were given LPS/GaIN (intraperitoneally [i.p.]). Survival, plasma transaminases, and histopathology were examined. Serum TNF-α and IL-1β were analyzed by ELISA. Hepatic apoptosis was analyzed by TUNEL and caspase-3 Western blotting, respectively. Compared to the model group, ALF induced by LPS/GaIN was alleviated remarkably following TAM administration, as evidenced by the improvement of survival (87.5% vs. 37.5%), hepatic swell, moderate transaminases, slightly increased serum TNF-α, IL-1β (P < 0.05), and moderate histopathology. In respect of apoptosis, severe hepatocellular apoptosis was reduced notably by TAM treatment confirmed by less TUNEL-positive hepatocytes and decreased caspase-3 cleavage. The results demonstrated that TAM could attenuate LPS/GaIN-induced ALF effectively, probably due to hepatic inflammation and apoptosis antagonism. Furthermore, it was the first report about the effect of TAM on LPS/GaIN-induced ALF.

  6. Peri-nuclear clustering of mitochondria is triggered during aluminum maltolate induced apoptosis.

    PubMed

    Dewitt, David A; Hurd, Jennifer A; Fox, Nena; Townsend, Brigitte E; Griffioen, Kathleen J S; Ghribi, Othman; Savory, John

    2006-07-01

    Synapse loss and neuronal death are key features of Alzheimer's disease pathology. Disrupted axonal transport of mitochondria is a potential mechanism that could contribute to both. As the major producer of ATP in the cell, transport of mitochondria to the synapse is required for synapse maintenance. However, mitochondria also play an important role in the regulation of apoptosis. Investigation of aluminum (Al) maltolate induced apoptosis in human NT2 cells led us to explore the relationship between apoptosis related changes and the disruption of mitochondrial transport. Similar to that observed with tau over expression, NT2 cells exhibit peri-nuclear clustering of mitochondria following treatment with Al maltolate. Neuritic processes largely lacked mitochondria, except in axonal swellings. Similar, but more rapid results were observed following staurosporine administration, indicating that the clustering effect was not specific to Al maltolate. Organelle clustering and transport disruption preceded apoptosis. Incubation with the caspase inhibitor zVAD-FMK effectively blocked apoptosis, however failed to prevent organelle clustering. Thus, transport disruption is associated with the initiation, but not necessarily the completion of apoptosis. These results, together with observed transport defects and apoptosis related changes in Alzheimer disease brain suggest that mitochondrial transport disruption may play a significant role in synapse loss and thus the pathogenesis or Alzheimer's disease.

  7. Cytoprotective effects of phenolic acids on methylglyoxal-induced apoptosis in Neuro-2A cells.

    PubMed

    Huang, Shang-Ming; Chuang, Hong-Chih; Wu, Chi-Hao; Yen, Gow-Chin

    2008-08-01

    In the process of glycation, methylglyoxal is a reactive dicarbonyl compound physiologically generated as an intermediate of glycolysis, and is found in high levels in blood or tissue of diabetic models. Biological glycation has been commonly implicated in the development of diabetic microvascular complications of neuropathy. Increasing evidence suggests that neuronal cell cycle regulatory failure followed by apoptosis is an important mechanism in the development of diabetic neuropathy complication. Naturally occurring antioxidants, especially phenolic acids have been recommended as the major bioactive compounds to prevent chronic diseases and promote health benefits. The objective of this study was to investigate the inhibitory abilities of phenolic acids (chlorogenic acid, syringic acid and vanillic acid) on methylglyoxal-induced mouse Neuro-2A neuroblastoma (Neuro-2A) cell apoptosis in the progression of diabetic neuropathy. The data indicated that methylglyoxal induced mouse Neuro-2A neuroblastoma (Neuro-2A) cell apoptosis via alternation of mitochondria membrane potential and Bax/Bcl-2 ratio, activation of caspase-3, and cleavage of poly (ADP-ribose) polymerase. Furthermore, the results demonstrated that activation of mitogen-activated protein kinase signal pathways (JNK and p38) participated in the methylglyoxal-induced Neuro-2A cell apoptosis process. Treatment of Neuro-2A cells with phenolic acids markedly suppresses cell apoptosis induced by methylglyoxal, suggesting that phenolic acids possess cytoprotective ability in the prevention of diabetic neuropathy complication.

  8. IL-1β induces apoptosis and autophagy via mitochondria pathway in human degenerative nucleus pulposus cells

    PubMed Central

    Shen, Jieliang; Xu, Shengxi; Zhou, Hao; Liu, Huzhe; Jiang, Wei; Hao, Jie; Hu, Zhenming

    2017-01-01

    IL-1β has been reported highly expressed in degenerative intervertebral disc, and our previous study indicated IL-1β facilitates apoptosis of human degenerative nucleus pulposus (NP) cell. However, the underlying molecular mechanism remains unclear. We here demonstrate that IL-1β played a significantly pro-apoptotic effect under serum deprivation. IL-1β decreased Bcl-2/Bax ratio and enhanced cytochrome C released from mitochondria to cytosol, which proved mitochondria-meidated apoptosis was induced. Subsequently, mitochondria damage was detected under IL-1β stimualtion. In addition, IL-1β-mediated injuried mitochondria contributes to activate autophagy. However, pretreatment with the autophagy inhibitor 3-methyladenine showed the potential in further elevating the apoptosis rate induced by IL-1β in NP cells. Our results indicated that the mitochondrial pathway was involved in IL-1β-induced apoptosis of NP cells. Meanwhile, the damaged mitochondria-induced autophagy played a protective role against apoptosis, suggesting a postive feedback mechanism under inflammatory stress. PMID:28120948

  9. 4-1BB protects dendritic cells from prostate cancer-induced apoptosis.

    PubMed

    Youlin, Kuang; Jianwei, Zhang; Xin, Gou; Li, Zhang; Xiaodong, Weng; Xiuheng, Liu; Hengchen, Zhu; Zhiyuan, Chen

    2013-04-01

    It has been shown that human prostate cancer (PCa) cells induced apoptotic death of the most potent antigen-presenting cells, dendritic cells (DCs), which are responsible for the induction of specific antitumor immune responses. Here, we investigated the function of 4-1BB on protecting DCs from prostate cancer-induced apoptosis with an agonistic mAb to 4-1BB. RM-1 cells and DCs were co-incubated for 48 h and DC apoptosis was assessed by Annexin Vassay. TNF-α and IL-12 production were assessed by enzyme-linked immunosorbent assay (ELISA) and Bcl-2 and Bcl-xL on DCs were analyzed by Western blot. We have shown that co-incubation of RM-1 cells with DCs is accompanied by an increased level of DCs apoptosis. Triggering 4-1BB on DCs resulted in increased resistance of DCs to RM-1 cells-induced apoptosis, which was owing to the up-regulated expression of Bcl-2 and Bcl-xL, and increased secretion of TNF-αand IL-12. These results demonstrate that triggering 4-1BB on DCs could increased resistance of DCs to PCa-induced apoptosis.

  10. 3-MCPD 1-Palmitate Induced Tubular Cell Apoptosis In Vivo via JNK/p53 Pathways.

    PubMed

    Liu, Man; Huang, Guoren; Wang, Thomas T Y; Sun, Xiangjun; Yu, Liangli Lucy

    2016-05-01

    Fatty acid esters of 3-chloro-1, 2-propanediol (3-MCPD esters) are a group of processing induced food contaminants with nephrotoxicity but the molecular mechanism(s) remains unclear. This study investigated whether and how the JNK/p53 pathway may play a role in the nephrotoxic effect of 3-MCPD esters using 3-MCPD 1-palmitate (MPE) as a probe compound in Sprague Dawley rats. Microarray analysis of the kidney from the Sprague Dawley rats treated with MPE, using Gene Ontology categories and KEGG pathways, revealed that MPE altered mRNA expressions of the genes involved in the mitogen-activated protein kinase (JNK and ERK), p53, and apoptotic signal transduction pathways. The changes in the mRNA expressions were confirmed by qRT-PCR and Western blot analyses and were consistent with the induction of tubular cell apoptosis as determined by histopathological, TUNEL, and immunohistochemistry analyses in the kidneys of the Sprague Dawley rats. Additionally, p53 knockout attenuated the apoptosis, and the apoptosis-related protein bax expression and cleaved caspase-3 activation induced by MPE in the p53 knockout C57BL/6 mice, whereas JNK inhibitor SP600125 but not ERK inhibitor U0126 inhibited MPE-induced apoptosis, supporting the conclusion that JNK/p53 might play a critical role in the tubular cell apoptosis induced by MPE and other 3-MCPD fatty acid esters.

  11. Clinostat rotation induces apoptosis in luteal cells of the pregnant rat

    NASA Technical Reports Server (NTRS)

    Yang, Hyunwon; Bhat, Ganapathy K.; Sridaran, Rajagopala

    2002-01-01

    Recent studies have shown that microgravity induces changes at the cellular level, including apoptosis. However, it is unknown whether microgravity affects luteal cell function. This study was performed to assess whether microgravity conditions generated by clinostat rotation induce apoptosis and affect steroidogenesis by luteal cells. Luteal cells isolated from the corpora lutea of Day 8 pregnant rats were placed in equal numbers in slide flasks (chamber slides). One slide flask was placed in the clinostat and the other served as a stationary control. At 48 h in the clinostat, whereas the levels of progesterone and total cellular protein decreased, the number of shrunken cells increased. To determine whether apoptosis occurred in shrunken cells, Comet and TUNEL assays were performed. At 48 h, the percentage of apoptotic cells in the clinostat increased compared with that in the control. To investigate how the microgravity conditions induce apoptosis, the active mitochondria in luteal cells were detected with JC-1 dye. Cells in the control consisted of many active mitochondria, which were evenly distributed throughout the cell. In contrast, cells in the clinostat displayed fewer active mitochondria, which were distributed either to the outer edge of the cell or around the nucleus. These results suggest that mitochondrial dysfunction induced by clinostat rotation could lead to apoptosis in luteal cells and suppression of progesterone production.

  12. NSAIDs induce apoptosis in nonproliferating ovarian cancer cells and inhibit tumor growth in vivo.

    PubMed

    Duncan, Kristal; Uwimpuhwe, Henriette; Czibere, Akos; Sarkar, Devanand; Libermann, Towia A; Fisher, Paul B; Zerbini, Luiz F

    2012-07-01

    Ovarian cancer (OC) is one of the most lethal gynaecological cancers, which usually has a poor prognosis due to late diagnosis. A large percentage of the OC cell population is in a nonproliferating and quiescent stage, which poses a barrier to success when using most chemotherapeutic agents. Recent studies have shown that several nonsteroidal anti-inflammatory drugs (NSAIDs) are effective in the treatment of OC. Furthermore, we have previously described the molecular mechanisms of NSAIDs' induction of cancer apoptosis. In this report, we evaluated various structurally distinct NSAIDs for their efficacies in inducing apoptosis in nonproliferating OC cells. Although several NSAIDs-induced apoptosis, Flufenamic Acid, Flurbiprofen, Finasteride, Celocoxib, and Ibuprofen were the most potent NSAIDs inducing apoptosis. A combination of these agents resulted in an enhanced effect. Furthermore, we demonstrate that the combination of Flurbiprofen, which targets nonproliferative cells, and Sulindac Sulfide, that affects proliferative cells, strongly reduced tumor growth when compared with a single agent treatment. Our data strongly support the hypothesis that drug treatment regimens that target nonproliferating and proliferating cells may have significant efficacy against OC. These results also provide a rationale for employing compounds or even chemically modified NSAIDs, which selectively and efficiently induce apoptosis in cells during different stages of the cell cycle, to design more potent anticancer drugs.

  13. Novel quinolone CHM-1 induces apoptosis and inhibits metastasis in a human osterogenic sarcoma cell line.

    PubMed

    Hsu, Shu-Chun; Yang, Jai-Sing; Kuo, Chao-Lin; Lo, Chyi; Lin, Jing-Pin; Hsia, Te-Chun; Lin, Jen-Jyh; Lai, Kuang-Chi; Kuo, Hsiu-Maan; Huang, Li-Jiau; Kuo, Sheng-Chu; Wood, W Gibson; Chung, Jing-Gung

    2009-12-01

    Novel 2-phenyl-4-quinolone compounds have potent cytotoxic effects on different human cancer cell lines. In this study, we examined anticancer activity and mechanisms of 20-fluoro-6,7-methylenedioxy-2-phenyl-4-quinolone (CHM-1) in human osterogenic sarcoma U-2 OS cells. CHM-1-induced apoptosis was determined by flow cytometric analysis, DAPI staining, Comet assay, and caspase inhibitors. CHM-1-inhibited cell migration and invasion was assessed by a wound healing assay, gelatin zymography, and a Transwell assay. The mechanisms of CHM-1 effects on apoptosis and metastasis signaling pathways were studied using Western blotting and gene expression. CHM-1 induced G2/M arrest and apoptosis at an IC(50) (3 microM) in U-2 OS cells and caspase-3, -8, and -9 were activated. Caspase inhibitors increased cell viability after exposure to CHM-1. CHM-1-induced apoptosis was associated with enhanced ROS generation, DNA damage, decreased DeltaPsi(m) levels, and promotion of mitochondrial cytochrome c release. CHM-1 stimulated mRNA expression of caspase-3, -8, and -9, AIF, and Endo G. In addition, CHM-1 inhibited cell metastasis at a low concentration (<3 microM). CHM-1 inhibited the cell metastasis through the inhibition of MMP-2, -7, and -9. CHM-1 also decreased the levels of MAPK signaling pathways before leading to the inhibition of MMPs. In summary, CHM-1 is a potent inducer of apoptosis, which plays a role in the anticancer activity of CHM-1.

  14. Glucose induces apoptosis of cardiomyocytes via microRNA-1 and IGF-1.

    PubMed

    Yu, Xi-Yong; Song, Yao-Hua; Geng, Yong-Jian; Lin, Qiu-Xiong; Shan, Zhi-Xin; Lin, Shu-Guang; Li, Yangxin

    2008-11-21

    Glucose toxicity is an important initiator of cardiovascular disease, contributing to the development of cardiomyocyte death and diabetic complications. The present study investigated whether high glucose state could induce apoptosis of rat cardiomyocyte cell line H9C2 through microRNA regulated insulin-like growth factor (IGF-1) signaling pathway. Our data showed that H9C2 cells exposed to high glucose have increased miR-1 expression level, decreased mitochondrial membrane potential, increased cytochrome-c release, and increased apoptosis. Glucose induced mitochondrial dysfunction, cytochrome-c release and apoptosis was blocked by IGF-1. Using prediction algorithms, we identified 3'-untranslated regions of IGF-1 gene are the target of miR-1. miR-1 mimics, but not mutant miR-1, blocked the capacity of IGF-1 to prevent glucose-induced mitochondrial dysfunction, cytochrome-c release and apoptosis. In conclusion, our data demonstrate that IGF-1 inhibits glucose-induced mitochondrial dysfunction, cytochrome-c release and apoptosis and IGF-1's effect is regulated by miR-1.

  15. Propofol induces apoptosis of hepatocellular carcinoma cells by upregulation of microRNA-199a expression.

    PubMed

    Zhang, Jian; Wu, Guo-qing; Zhang, Yan; Feng, Zhi-ying; Zhu, Sheng-mei

    2013-03-01

    Propofol is one of the extensively commonly used intravenous anaesthetic agents. The effects of Propofol on hepatocellular carcinoma (HCC) growth inhibition and apoptosis have been examined. The techniques used were the MTT assay, flow cytometry, real-time PCR to assess miR-199a expression, as also caspase-8 and caspase-9 activity in HepG2 cells treated with Propofol. Finally, we evaluated the effect of miR-199a on Propofol-induced anti-tumour activity using anti-miR-199a. Propofol efficiently inhibited the growth of HCC cells, but was less toxic to normal hepatic cells. It induced apoptosis and increased expression of miR-199a. Activation of caspase-8 and caspase-9 suggested that both extrinsic and intrinsic pathways are involved in Propofol-induced apoptosis. Anti-miR-199a reversed the effect of Propofol on apoptosis and activation of caspase-8 and caspase-9 in HepG2 cells. Propofol can effectively induce apoptosis of HCC cells and modulation of miR-199a possibly contributes to the anti-tumour action of Propofol. Hence, Propofol might be an effective drug for HCC.

  16. Measurement of caspase-2 activation during different anti-tumor drugs induced apoptosis by FRET technique

    NASA Astrophysics Data System (ADS)

    Lin, Juqiang; Zeng, Shaoqun; Luo, Qingming; Rong, Chen; Zhang, Zhihong

    2007-11-01

    Caspase-2 is important for the engagement of the mitochondrial apoptotic pathway, in the presence of DNA-damaging agents, such as cisplatin; however, the mechanism by which caspase-2 executes apoptosis remains obscure. In this study, we carried out the measurements of the dynamics of caspase-2 activation in a single living cell by a FRET (fluorescence resonance energy transfer) probe. A FRET probe was constructed that encoded a CRS (caspase-2 recognition site) fused with a cyan fluorescent protein (CFP) and a red fluorescent protein (DsRed) (CFP-CRS-DsRed). Using this probe, we found that during TRAIL-induced apoptosis, caspase-2 was not activated, and caspase-2 activation occurred in etoposide and cisplatin treated cells. However, during cisplatin-induced apoptosis caspase-2 activation was initiated much earlier than that of etoposide. Cisplatin and etoposide is one of the most broadly used drugs in the Clinical applications of cancer chemotherapy, and TRAIL, which belongs to the TNF family proteins, can selectively induce apoptosis in many transformed cells but not in normal cells. Most of anticancer drugs can induce apoptosis mediated by the activation of caspase pathway. Thus, the perfect synergistic effect group of multi-drug can be selected by using our FRET probe.

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

    SciTech Connect

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

    2009-02-01

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

  18. Vitamin B6 suppresses apoptosis of NM-1 bovine endothelial cells induced by homocysteine and copper.

    PubMed

    Endo, Naoko; Nishiyama, Kazuo; Okabe, Masaaki; Matsumoto, Mitsuharu; Kanouchi, Hiroaki; Oka, Tatsuzo

    2007-04-01

    Hyperhomocysteinemia is an important risk factor for atherosclerosis. We previously reported that formation of early atherosclerosis in the rat aorta was associated with hyperhomocysteinemia and reduction of antioxidant activity caused by low concentration of vitamin B(6)in vivo. In the present study, we examined effects of vitamin B(6) on apoptosis of bovine endothelial cells (NM-1 cells) treated with homocysteine and copper. Homocysteine and copper induced extracellular hydrogen peroxide, intracellular ROS and cellular lipid peroxide levels. Cell viability was reduced to 30% compared to that of control cells. On the other hand, pyridoxal treatment as well as EDTA treatment increased viability of NM-1 cells treated with homocysteine and copper to about 60%, and significantly decreased extracellular hydrogen peroxide, intracellular ROS and cellular lipid peroxide levels. The treatment of catalase recovered cell viability and reduced the level of extracellular hydrogen peroxide and intracellular ROS. Cell death by homocysteine and copper was confirmed to be due to apoptosis by evaluation of DNA fragmentation and by TUNEL assay. However, apoptosis of NM-1 cells induced by homocysteine and copper was due to a caspase-independent pathway as it was not inhibited by the caspase inhibitor, Z-VAD-fmk. Apoptosis of NM-1 cells induced by homocysteine and copper accompanied with mitochondrial permeability but not cytochrome c release. These results suggest that pyridoxal treatment suppresses apoptosis of NM-1 cells induced by homocysteine and copper, most likely through antioxidant effects.

  19. Acrylonitrile induced apoptosis via oxidative stress in neuroblastoma SH-SY5Y cell.

    PubMed

    Watcharasit, Piyajit; Suntararuks, Sumitra; Visitnonthachai, Daranee; Thiantanawat, Apinya; Satayavivad, Jutamaad

    2010-10-01

    Acrylonitrile (ACN) is a chemical that is widely used in the production of plastics, acrylic fibers, synthetic rubbers and resins. It has been reported that ACN can cause oxidative stress, a condition which is well recognized as an apoptotic initiator; however, information regarding ACN-induced apoptosis is limited. This present study investigated whether ACN induces apoptosis in human neuroblastoma SH-SY5Y cells, and whether its apoptotic induction involves oxidative stress. The results showed that ACN caused activation of caspase-3, a key enzyme involved in apoptosis, in a dose- and time-dependent manner. Detection of sub-G1 apoptotic cell death and apoptotic nuclear condensation revealed that ACN caused an increase in the number of apoptotic cells indicating ACN induces apoptosis in SH-SY5Y cells. ACN dose- and time-dependently increased the level of proapoptotic protein, Bax. Pretreatment with N-acetylcysteine (NAC), an antioxidant, attenuated caspase-3 activation by ACN, as evidenced by a reduction in proteolysis of PARP, a known caspase-3 substrate, as well as in the number of sub-G1 apoptotic cells. Moreover, induction of Bax by ACN was abolished by NAC. Taken together, the results indicate that ACN induces apoptosis in SH-SY5Y cells via a mechanism involving generation of oxidative stress-mediated Bax induction.

  20. Betulinic Acid Induces Apoptosis in Differentiated PC12 Cells Via ROS-Mediated Mitochondrial Pathway.

    PubMed

    Wang, Xi; Lu, Xiaocheng; Zhu, Ronglan; Zhang, Kaixin; Li, Shuai; Chen, Zhongjun; Li, Lixin

    2017-01-25

    Betulinic acid (BA), a pentacyclic triterpene of natural origin, has been demonstrated to have varied biologic activities including anti-viral, anti-inflammatory, and anti-malarial effects; it has also been found to induce apoptosis in many types of cancer. However, little is known about the effect of BA on normal cells. In this study, the effects of BA on normal neuronal cell apoptosis and the mechanisms involved were studied using differentiated PC12 cells as a model. Treatment with 50 μM BA for 24 h apparently induced PC12 cell apoptosis. In the early stage of apoptosis, the level of intracellular reactive oxygen species (ROS) increased. Afterwards, the loss of the mitochondrial membrane potential, the release of cytochrome c and the activation of caspase-3 occurred. Treatment with antioxidants could significantly reduce BA-induced PC12 cell apoptosis. In conclusion, we report for the first time that BA induced the mitochondrial apoptotic pathway in differentiated PC12 cells through ROS.

  1. Mycobacterium avium MAV2054 protein induces macrophage apoptosis by targeting mitochondria and reduces intracellular bacterial growth

    PubMed Central

    Lee, Kang-In; Whang, Jake; Choi, Han-Gyu; Son, Yeo-Jin; Jeon, Haet Sal; Back, Yong Woo; Park, Hye-Soo; Paik, Seungwha; Park, Jeong-Kyu; Choi, Chul Hee; Kim, Hwa-Jung

    2016-01-01

    Mycobacterium avium complex induces macrophage apoptosis. However, the M. avium components that inhibit or trigger apoptosis and their regulating mechanisms remain unclear. We recently identified the immunodominant MAV2054 protein by fractionating M. avium culture filtrate protein by multistep chromatography; this protein showed strong immuno-reactivity in M. avium complex pulmonary disease and in patients with tuberculosis. Here, we investigated the biological effects of MAV2054 on murine macrophages. Recombinant MAV2054 induced caspase-dependent macrophage apoptosis. Enhanced reactive oxygen species production and JNK activation were essential for MAV2054-mediated apoptosis and MAV2054-induced interleukin-6, tumour necrosis factor, and monocyte chemoattractant protein-1 production. MAV2054 was targeted to the mitochondrial compartment of macrophages treated with MAV2054 and infected with M. avium. Dissipation of the mitochondrial transmembrane potential (ΔΨm) and depletion of cytochrome c also occurred in MAV2054-treated macrophages. Apoptotic response, reactive oxygen species production, and ΔΨm collapse were significantly increased in bone marrow-derived macrophages infected with Mycobacterium smegmatis expressing MAV2054, compared to that in M. smegmatis control. Furthermore, MAV2054 expression suppressed intracellular growth of M. smegmatis and increased the survival rate of M. smegmatis-infected mice. Thus, MAV2054 induces apoptosis via a mitochondrial pathway in macrophages, which may be an innate cellular response to limit intracellular M. avium multiplication. PMID:27901051

  2. FTY720 induces autophagy-related apoptosis and necroptosis in human glioblastoma cells.

    PubMed

    Zhang, Li; Wang, Handong; Ding, Ke; Xu, Jianguo

    2015-07-02

    FTY720 is a potent immunosuppressant which has preclinical antitumor efficacy in various cancer models. However, its role in glioblastoma remains unclear. In the present study, we found that FTY720 induced extrinsic apoptosis, necroptosis and autophagy in human glioblastoma cells. Inhibition of autophagy by either RNA interference or chemical inhibitors attenuated FTY720-induced apoptosis and necrosis. Furthermore, autophagy, apoptosis and necrosis induction were dependent on reactive oxygen species-c-Jun N-terminal kinase-protein 53 (ROS-JNK-p53) loop mediated phosphatidylinositide 3-kinases/protein kinase B/mammalian target of rapamycin/p70S6 kinase (PI3K/AKT/mTOR/p70S6K) pathway. In addition, receptor-interacting protein 1 and 3 (RIP1 and RIP3) served as an upstream of ROS-JNK-p53 loop. However, the phosphorylation form of FTY720 induced autophagy but not apoptosis and necroptosis. Finally, the in vitro results were validated in vivo in xenograft mouse of glioblastoma cells. In conclusion, the current study provided novel insights into understanding the mechanisms and functions of FTY720-induced apoptosis, necroptosis and autophagy in human glioblastoma cells.

  3. Lentiviral Delivery of HIV-1 Vpr Protein Induces Apoptosis in Transformed Cells

    NASA Astrophysics Data System (ADS)

    Stewart, Sheila A.; Poon, Betty; Jowett, Jeremy B. M.; Xie, Yiming; Chen, Irvin S. Y.

    1999-10-01

    Most current anticancer therapies act by inducing tumor cell stasis followed by apoptosis. HIV-1 Vpr effectively induces apoptosis of T cells after arrest of cells at a G2/M checkpoint. Here, we investigated whether this property of Vpr could be exploited for use as a potential anticancer agent. As a potentially safer alternative to transfer of genes encoding Vpr, we developed a method to efficiently introduce Vpr protein directly into cells. Vpr packaged into HIV-1 virions lacking a genome induced efficient cell cycle arrest and apoptosis. Introduction of Vpr into tumor cell lines of various tissue origin, including those bearing predisposing mutations in p53, XPA, and hMLH1, induced cell cycle arrest and apoptosis with high efficiency. Significantly, apoptosis mediated by virion-associated Vpr was more effective on rapidly dividing cells compared with slow-growing cells, thus, in concept, providing a potential differential effect between some types of tumor cells and surrounding normal cells. This model system provides a rationale and proof of concept for the development of potential cancer therapeutic agents based on the growth-arresting and apoptotic properties of Vpr.

  4. Spatial and temporal changes in Bax subcellular localization during NPe6-PDT-induced apoptosis

    NASA Astrophysics Data System (ADS)

    Liu, Lei; Xing, Da; Chen, Wei R.; Wan, Qingling; Zhou, Feifan

    2008-02-01

    Photodynamic therapy (PDT) employing photosensiter N-aspartyl chlorin e6 (NPe6) can induce lysosome disruption and initiate the intrinsic apoptotic pathway. Bax, a member of the Bcl-2 family of proteins, is an essential regulator of apoptosis. Bax is normally found in the cytosol of healthy cells, and translocates to mitochondria in response to many apoptotic stimuli. In this study, using real-time single-cell analysis, we have investigated the kinetics of Bax distribution during NPe6-induced apoptosis in ASTC-a-1 cells. In order to monitor Bax subcellular distribution, cells were stained with GFP-Bax and Mito Tracker Red. The results show that Bax redistribution occurred at about 170 min after treated with NPe6-PDT, and then sequestered into clusters associated with the mitochondira within 30 min. Our data clearly showed the spatial and temporal changes in Bax distribution in living cells during NPe6-induced apoptosis.

  5. Deoxynivalenol inhibits proliferation and induces apoptosis in human umbilical vein endothelial cells.

    PubMed

    Deng, Chao; Ji, Changyun; Qin, Weisen; Cao, Xifeng; Zhong, Jialian; Li, Yugu; Srinivas, Swaminath; Feng, Youjun; Deng, Xianbo

    2016-04-01

    Deoxynivalenol (DON) is a stable mycotoxins found in cereals infected by certain fungal species and causes adverse health effects in animals and human such as vomiting, diarrhea and reproductive toxicity. In this study, we investigated the toxic and apoptotic effects of DON in human umbilical vein endothelial cells (HUVECs), a good model for studying inflammation. The results show that DON significantly inhibited the viability of HUVECs. DON could also inhibit the proliferation of HUVECs through G2/M phase arrest in cell cycle progression. Moreover, oxidative stress induced by DON was indicated by observations of increased levels of reactive oxygen species (ROS). In addition, DON also causes mitochondrial damage by decreasing the mitochondrial membrane potential and inducing apoptosis by up-regulation of apoptosis-related genes like caspase-3, caspase-9, and Bax genes, and down-regulation of Bcl-2 gene. These results together suggest that DON could induce cell cycle arrest, oxidative stress, and apoptosis in HUVECs.

  6. Hyperglycemia induces apoptosis and p53 mobilization to mitochondria in RINm5F cells.

    PubMed

    Ortega-Camarillo, C; Guzmán-Grenfell, A M; García-Macedo, R; Rosales-Torres, A M; Avalos-Rodríguez, A; Durán-Reyes, G; Medina-Navarro, R; Cruz, M; Díaz-Flores, M; Kumate, J

    2006-01-01

    The mechanisms related to hyperglycemia-induced pancreatic beta-cell apoptosis are poorly defined. Rat insulin-producing cells (RINm5F) cultured in high glucose concentrations (30 mM) showed increased apoptosis and protein p53 translocation to mitochondria. In addition, hyperglycemia induced both the disruption of mitochondrial membrane potential (Delta psi (m)), and an increase in reactive oxygen species (ROS), as shown by fluorescence changes of JC-1 and dichlorodihydrofluorescein-diacetate (DCDHF-DA), respectively. The increased intracellular ROS by high glucose exposure was blunted by mitochondrial-function and NADPH-oxidase inhibitors. We postulate that the concomitant mobilization of p53 protein to the mitochondria and the subsequent changes on the Delta psi (m), lead to an important pancreatic beta-cell apoptosis mechanism induced by oxidative stress caused by hyperglycemia.

  7. Bax is not involved in the resveratrol-induced apoptosis in human lung adenocarcinoma cells

    NASA Astrophysics Data System (ADS)

    Zhang, Wei-wei; Wang, Zhi-ping; Chen, Tong-sheng

    2010-02-01

    Resveratrol (RV) is a natural plant polyphenol widely present in foods such as grapes, wine, and peanuts. Previous studies indicate that RV has an ability to inhibit various stages of carcinogenesis and eliminate preneoplastic cells in vitro and in vivo. However, little is known about the molecular mechanism of RV-induced apoptosis in human lung adenocarcinoma (ASTC-a-1) cell. In this report, we analyzed whether Bax translocation from cytoplasm to mitochondria during RV-induced apoptosis in single living cell using onfocal microscopey. Cells were transfected with GFP-Bax plasmid. Cell counting kit (CCK-8) assay was used to assess the inhibition of RV on the cells viability. Apoptotic activity of RV was detected by Hoechst 33258 and propidium iodide (PI) staining. Our results showed that RV induced a dose-dependent apoptosis in which Bax did not translocate to mitochondrias.

  8. Death Inducer-Obliterator 1 Triggers Apoptosis after Nuclear Translocation and Caspase Upregulation

    PubMed Central

    García-Domingo, David; Ramírez, Dorian; González de Buitrago, Gonzalo; Martínez-A, Carlos

    2003-01-01

    Death inducer-obliterator 1 (DIO-1) is a gene that is upregulated early in apoptosis. Here we report that in healthy cells, the DIO-1 gene product was located in the cytoplasm, where it formed oligomers. After interleukin-3 starvation or c-Myc-induced apoptosis in serum-free conditions, DIO-1 translocated to the nucleus, where it upregulated caspase levels and activity. A nuclear localization signal deletion mutant (DIO-1ΔNLS) was unable to translocate to the nuclear compartment in the absence of interleukin-3 and failed to upregulate procaspase levels or trigger cell death. In addition, cells stably expressing DIO-1ΔNLS were protected from apoptosis induced by interleukin-3 withdrawal. These results indicate that DIO-1 has a relevant role in regulating the early stages of cell death. PMID:12697821

  9. Fast neutrons-induced apoptosis is Fas-independent in lymphoblastoid cells

    SciTech Connect

    Fischer, Barbara; Benzina, Sami; Jeannequin, Pierre; Dufour, Patrick; Bergerat, Jean-Pierre; Denis, Jean-Marc; Gueulette, John; Bischoff, Pierre L. . E-mail: Pierre.Bischoff@ircad.u-strasbg.fr

    2005-08-26

    We have previously shown that ionizing radiation-induced apoptosis in human lymphoblastoid cells differs according to their p53 status, and that caspase 8-mediated cleavage of BID is involved in the p53-dependent pathway. In the present study, we investigated the role of Fas signaling in caspase 8 activation induced by fast neutrons irradiation in these cells. Fas and FasL expression was assessed by flow cytometry and by immunoblot. We also measured Fas aggregation after irradiation by fluorescence microscopy. We found a decrease of Fas expression after irradiation, but no change in Fas ligand expression. We also showed that, in contrast to the stimulation of Fas by an agonistic antibody, Fas aggregation did not occur after irradiation. Altogether, our data strongly suggest that fast neutrons induced-apoptosis is Fas-independent, even in p53-dependent apoptosis.

  10. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) triggers apoptosis in normal prostate epithelial cells.

    PubMed

    Nesterov, Alexandre; Ivashchenko, Yuri; Kraft, Andrew S

    2002-02-07

    TRAIL is a pro-apoptotic cytokine believed to selectively kill cancer cells without harming normal ones. However, we found that in normal human prostate epithelial cells (PrEC) TRAIL is capable of inducing apoptosis as efficiently as in some tumor cell lines. At the same time, TRAIL did not cause