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Sample records for inhibits calpain-induced apoptosis

  1. Brucella infection inhibits macrophages apoptosis via Nedd4-dependent degradation of calpain2.

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    Cui, Guimei; Wei, Pan; Zhao, Yuxi; Guan, Zhenhong; Yang, Li; Sun, Wanchun; Wang, Shuangxi; Peng, Qisheng

    2014-11-07

    The calcium-dependent protease calpain2 is involved in macrophages apoptosis. Brucella infection-induced up-regulation of intracellular calcium level is an essential factor for the intracellular survival of Brucella within macrophages. Here, we hypothesize that calcium-dependent E3 ubiquitin ligase Nedd4 ubiquitinates calpain2 and inhibits Brucella infection-induced macrophage apoptosis via degradation of calpain2.Our results reveal that Brucella infection induces increases in Nedd4 activity in an intracellular calcium dependent manner. Furthermore, Brucella infection-induced degradation of calpain2 is mediated by Nedd4 ubiquitination of calpain2. Brucella infection-induced calpain2 degradation inhibited macrophages apoptosis. Treatment of Brucella infected macrophages with calcium chelator BAPTA or Nedd4 knock-down decreased Nedd4 activity, prevented calpain2 degradation, and resulted in macrophages apoptosis. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Similar to spironolactone, oxymatrine is protective in aldosterone-induced cardiomyocyte injury via inhibition of calpain and apoptosis-inducing factor signaling.

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    Ting-Ting Xiao

    Full Text Available Accumulating evidence indicates that oxymatrine (OMT possesses variously pharmacological properties, especially on the cardiovascular system. We previously demonstrated that activated calpain/apoptosis-inducing factor (AIF-mediated pathway was the key molecular mechanism in aldosterone (ALD induces cardiomyocytes apoptosis. In the present study, we extended the experimentation by investigating the effect of OMT on cardiomyocytes exposed to ALD, as compared to spironolactone (Spiro, a classical ALD receptor antagonist. Cardiomyocytes were pre-incubated with OMT, Spiro or vehicle for 1 h, and then, cardiomyocytes were exposed to ALD 24 h. The cell injury was evaluated by 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay and lactate dehydrogenase (LDH leakage ratio. Apoptosis was determined by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL assay, annexin V/PI staining, and relative caspase-3 activity assay. Furthermore, expression of pro-apoptotic proteins including truncated Bid (tBid, calpain and AIF were evaluated by western blot analysis. ALD stimulation increased cardiomyocytes apoptosis, caspase-3 activity and protein expression of calpain, tBid and AIF in the cytosol (p<0.05. Pre-incubated with cardiomyocytes injury and increased caspase-3 activity were significantly attenuated (p<0.05. Furthermore, OMT suppressed ALD-induced high expression of calpain and AIF. And these effects of OMT could be comparable to Spiro. These findings indicated that OMT might be a potential cardioprotective-agent against excessive ALD-induced cardiotoxicity, at least in part, mediated through inhibition of calpain/AIF signaling.

  3. Arsenic-induced alteration in intracellular calcium homeostasis induces head kidney macrophage apoptosis involving the activation of calpain-2 and ERK in Clarias batrachus

    International Nuclear Information System (INIS)

    Banerjee, Chaitali; Goswami, Ramansu; Datta, Soma; Rajagopal, R.; Mazumder, Shibnath

    2011-01-01

    We had earlier shown that exposure to arsenic (0.50 μM) caused caspase-3 mediated head kidney macrophage (HKM) apoptosis involving the p38-JNK pathway in Clarias batrachus. Here we examined the roles of calcium (Ca 2+ ) and extra-cellular signal-regulated protein kinase (ERK), the other member of MAPK-pathway on arsenic-induced HKM apoptosis. Arsenic-induced HKM apoptosis involved increased expression of ERK and calpain-2. Nifedipine, verapamil and EGTA pre-treatment inhibited the activation of calpain-2, ERK and reduced arsenic-induced HKM apoptosis as evidenced from reduced caspase-3 activity, Annexin V-FITC-propidium iodide and Hoechst 33342 staining. Pre-incubation with ERK inhibitor U 0126 inhibited the activation of calpain-2 and interfered with arsenic-induced HKM apoptosis. Additionally, pre-incubation with calpain-2 inhibitor also interfered with the activation of ERK and inhibited arsenic-induced HKM apoptosis. The NADPH oxidase inhibitor apocynin and diphenyleneiodonium chloride also inhibited ERK activation indicating activation of ERK in arsenic-exposed HKM also depends on signals from NADPH oxidase pathway. Our study demonstrates the critical role of Ca 2+ homeostasis on arsenic-induced HKM apoptosis. We suggest that arsenic-induced alteration in intracellular Ca 2+ levels initiates pro-apoptotic ERK and calpain-2; the two pathways influence each other positively and induce caspase-3 mediated HKM apoptosis. Besides, our study also indicates the role of ROS in the activation of ERK pathway in arsenic-induced HKM apoptosis in C. batrachus. - Highlights: → Altered Ca 2+ homeostasis leads to arsenic-induced HKM apoptosis. → Calpain-2 plays a critical role in the process. → ERK is pro-apoptotic in arsenic-induced HKM apoptosis. → Arsenic-induced HKM apoptosis involves cross talk between calpain-2 and ERK.

  4. Glutamate-induced apoptosis in neuronal cells is mediated via caspase-dependent and independent mechanisms involving calpain and caspase-3 proteases as well as apoptosis inducing factor (AIF and this process is inhibited by equine estrogens

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    Bhavnani Bhagu R

    2006-06-01

    Full Text Available Abstract Background Glutamate, a major excitatory amino acid neurotransmitter, causes apoptotic neuronal cell death at high concentrations. Our previous studies have shown that depending on the neuronal cell type, glutamate-induced apoptotic cell death was associated with regulation of genes such as Bcl-2, Bax, and/or caspase-3 and mitochondrial cytochrome c. To further delineate the intracellular mechanisms, we have investigated the role of calpain, an important calcium-dependent protease thought to be involved in apoptosis along with mitochondrial apoptosis inducing factor (AIF and caspase-3 in primary cortical cells and a mouse hippocampal cell line HT22. Results Glutamate-induced apoptotic cell death in neuronal cells was associated with characteristic DNA fragmentation, morphological changes, activation of calpain and caspase-3 as well as the upregulation and/or translocation of AIF from mitochondria into cytosol and nuclei. Our results reveal that primary cortical cells and HT22 cells display different patterns of regulation of these genes/proteins. In primary cortical cells, glutamate induces activation of calpain, caspase-3 and translocation of AIF from mitochondria to cytosol and nuclei. In contrast, in HT22 cells, only the activation of calpain and upregulation and translocation of AIF occurred. In both cell types, these processes were inhibited/reversed by 17β-estradiol and Δ8,17β-estradiol with the latter being more potent. Conclusion Depending upon the neuronal cell type, at least two mechanisms are involved in glutamate-induced apoptosis: a caspase-3-dependent pathway and a caspase-independent pathway involving calpain and AIF. Since HT22 cells lack caspase-3, glutamate-induced apoptosis is mediated via the caspase-independent pathway in this cell line. Kinetics of this apoptotic pathway further indicate that calpain rather than caspase-3, plays a critical role in the glutamate-induced apoptosis. Our studies further indicate

  5. Cadmium induces Ca2+ mediated, calpain-1/caspase-3-dependent apoptosis in primary cultured rat proximal tubular cells.

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    Wang, Hong; Zhai, Nianhui; Chen, Ying; Xu, Haibin; Huang, Kehe

    2017-07-01

    Calcium, as a ubiquitous second messenger, governs a large array of cellular processes and is necessary for cell survival. More recently, it was observed that the cytosolic Ca 2+ concentration ([Ca 2+ ] c ) elevation could induce apoptosis in primary cultured rat proximal tubular (rPT) cells exposed to cadmium (Cd), but the concrete mechanism is still unclear. This study was designed to investigate the signal pathway involved in [Ca 2+ ] c elevation-mediated apoptosis. The results confirmed the elevation of [Ca 2+ ] c by confocal microscopy and enhancement of the apoptosis by Hoechst 33258 staining and flow cytometer when rPT cells were exposed to Cd for 12h. Then we demonstrated that Cd enhanced the protein levels of active calpain-1 and caspase-3 in rPT cells. Pretreatment with a cytosolic Ca 2+ chelator, 1,2-Bis (2-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid acetoxymethyl ester (BAPTA-AM), markedly blocked the up-regulation of active calpain-1 and caspase-3 and inhibited the apoptosis induced by Cd. Further, rPT cells were pretreated with a cell-permeable selective calpain-1 inhibitor, 3-(4-iodophenyl)-2-mercapto-(Z)-2-propenoic acid (PD150606) and caspase-3 inhibitor, N-Acetyl-Asp-Glu-Val-Asp-CHO (Ac-DEVD-CHO), respectively. PD150606 significantly attenuated the up-regulation of active caspase-3 and the apoptosis induced by Cd. As expected, inhibition of active caspase-3 by Ac-DEVD-CHO decreased the apoptosis induced by Cd. Taken together, it could be concluded that [Ca 2+ ] c elevation did act as a pro-apoptotic signal in Cd-induced cytotoxicity of rPT cells, triggered calpain-1 and caspase-3 activation in turn, and induced apoptosis of rPT cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Sequential activation of proteases in radiation induced apoptosis

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    Watters, D.; Waterhouse, N.

    1997-01-01

    Full text: Significant advances have been made in recent years in unraveling the molecular mechanisms of apoptosis particularly in relation to Fas- and TNF-mediated cell death, however there are considerable gaps in our knowledge of the processes involved in apoptosis induced by ionizing radiation. We have used the degradation of specific proteolytic targets in a pair of isogenic Burkitt's Iymphoma cells lines (BL30A, sensitive and BL30K resistant) to study the sequence of events in the execution of radiation-induced apoptosis. Fodrin can be cleaved to fragments of 150 kDa and 120 kDa. In the case of Fas-mediated apoptosis both cleavages are inhibited by the caspase inhibitor zVAD-fmk at 10 μM, a concentration which inhibits all the hallmarks of apoptosis. However in radiation-induced apoptosis, inhibition of the clevage of fodrin to the 150 kDa fragment requires 100 μM zVAD-fink while apoptosis itself is inhibited at 10 μM. This suggests that different enzymes are responsible for the generation of the 150 kDa fragment in the two models of apoptosis. Fodrin has been reported to be cleaved by μ-calpain to a 150 kDa fragment however, the involvement of μ-calpain in apoptosis has not yet been established. In murine fodrin there is a caspase cleavage site within 1 kDa of the calpain cleavage site. In vitro studies using purified enzymes showed that only caspase-3 and μ-calpain could cleave fodrin in untreated cell extracts to the same sized fragments as seen during apoptosis in vivo. We provide evidence for the early activation of μ-calpain after ionizing radiation in the sensitive BL30A cell line, and show that the time course of μ-calpain activation parallels that of the appearance of the 150 kDa fragment. Caspase-3 is activated much later and is likely to be responsible for the generation of the 120 kDa fragment. μ-Calpain was not activated in the resistant cell line. Based on these results we propose a model for the proteolytic cascade in radiation-induced

  7. Cisplatin-induced apoptosis inhibits autophagy, which acts as a pro-survival mechanism in human melanoma cells.

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    Del Bello, Barbara; Toscano, Marzia; Moretti, Daniele; Maellaro, Emilia

    2013-01-01

    The interplay between a non-lethal autophagic response and apoptotic cell death is still a matter of debate in cancer cell biology. In the present study performed on human melanoma cells, we investigate the role of basal or stimulated autophagy in cisplatin-induced cytotoxicity, as well as the contribution of cisplatin-induced activation of caspases 3/7 and conventional calpains. The results show that, while down-regulating Beclin-1, Atg14 and LC3-II, cisplatin treatment inhibits the basal autophagic response, impairing a physiological pro-survival response. Consistently, exogenously stimulated autophagy, obtained with trehalose or calpains inhibitors (MDL-28170 and calpeptin), protects from cisplatin-induced apoptosis, and such a protection is reverted by inhibiting autophagy with 3-methyladenine or ATG5 silencing. In addition, during trehalose-stimulated autophagy, the cisplatin-induced activation of calpains is abrogated, suggesting the existence of a feedback loop between the autophagic process and calpains. On the whole, our results demonstrate that in human melanoma cells autophagy may function as a beneficial stress response, hindered by cisplatin-induced death mechanisms. In a therapeutic perspective, these findings suggest that the efficacy of cisplatin-based polychemotherapies for melanoma could be potentiated by inhibitors of autophagy.

  8. Silibinin induces apoptosis via calpain-dependent AIF nuclear translocation in U87MG human glioma cell death

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    Kim Yong K

    2011-04-01

    Full Text Available Abstract Background Silibinin, a natural polyphenolic flavonoid, has been reported to induce cell death in various cancer cell types. However, the molecular mechanism is not clearly defined. Our previous study showed that silibinin induces glioma cell death and its effect was effectively prevented by calpain inhibitor. The present study was therefore undertaken to examine the role of calpain in the silibinin-induced glioma cell death. Methods U87MG cells were grown on well tissue culture plates and cell viability was measured by MTT assay. ROS generation and △ψm were estimated using the fluorescence dyes. PKC activation and Bax expression were measured by Western blot analysis. AIF nuclear translocation was determined by Western blot and immunocytochemistry. Results Silibinin induced activation of calpain, which was blocked by EGTA and the calpain inhibitor Z-Leu-Leu-CHO. Silibinin caused ROS generation and its effect was inhibited by calpain inhibitor, the general PKC inhibitor GF 109203X, the specific PKCδ inhibitor rottlerin, and catalase. Silibinin-induce cell death was blocked by calpain inhibitor and PKC inhibitors. Silibinin-induced PKCδ activation and disruption of △ψm were prevented by the calpain inhibitor. Silibinin induced AIF nuclear translocation and its effect was prevented by calpain inhibitor. Transfection of vector expressing microRNA of AIF prevented the silibinin-induced cell death. Conclusions Silibinin induces apoptotic cell death through a calpain-dependent mechanism involving PKC, ROS, and AIF nuclear translocation in U87MG human glioma cells.

  9. Inhibitors of cysteine cathepsin and calpain do not prevent ultraviolet-B-induced apoptosis in human keratinocytes and HeLa cells

    DEFF Research Database (Denmark)

    Bang, Bo; Baadsgaard, Ole; Skov, Lone

    2004-01-01

    been demonstrated to play a role in the execution of programmed cell death induced by other stimuli, e.g. TNF-alpha. The purpose of the present study was therefore to investigate whether inhibitors of cysteine cathepsins and calpains could prevent UVB-induced apoptosis in HeLa cells and keratinocytes....... This was done by investigating the effect of the irreversible cysteine protease inhibitor zFA-fmk, the cathepsin B inhibitor CA-074-Me and the calpain inhibitor ALLN on the viability of UVB-irradiated human keratinocytes and HeLa cells. At concentrations of 10 microM and above zVAD-fmk conferred partial dose......-dependent protection against UVB-induced apoptosis in HeLa cells and keratinocytes. Moreover, caspase-3 activity was completely blocked at zVAD-fmk concentrations of 1 microM in HeLa cells. This indicates that caspase-independent mechanisms could be involved in UVB-induced apoptosis. However, the protease inhibitors z...

  10. Increased μ-Calpain Activity in Blasts of Common B-Precursor Childhood Acute Lymphoblastic Leukemia Correlates with Their Lower Susceptibility to Apoptosis.

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    Anna Mikosik

    Full Text Available Childhood acute lymphoblastic leukemia (ALL blasts are characterized by inhibited apoptosis promoting fast disease progress. It is known that in chronic lymphocytic and acute myeloid leukemias the reduced apoptosis is strongly related with the activity of calpain-calpastatin system (CCS composed of cytoplasmic proteases--calpains--performing the modulatory proteolysis of key proteins involved in cell proliferation and apoptosis, and of their endogenous inhibitor--calpastatin. Here, the CCS protein abundance and activity was for the first time studied in childhood ALL blasts and in control bone marrow CD19+ B cells by semi-quantitative flow cytometry and western blotting of calpastatin fragments resulting from endogenous calpain activity. Significantly higher μ-calpain (CAPN1 gene transcription, protein amounts and activity (but not those of m-calpain, with calpastatin amount and transcription of its gene (CAST greatly varying were observed in CD19(+ ALL blasts compared to control cells. Significant inverse relation between the amount/activity of calpain and spontaneous apoptosis was noted. Patients older than 10 years (considered at higher risk displayed increased amounts and activities of blast calpain. Finally, treatment of blasts with the tripeptide calpain inhibitors II and IV significantly and in dose-dependent fashion increased the percentage of blasts entering apoptosis. Together, these findings make the CCS a potential new predictive tool and therapeutic target in childhood ALL.

  11. Calcium plays a key role in paraoxon-induced apoptosis in EL4 cells by regulating both endoplasmic reticulum- and mitochondria-associated pathways.

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    Li, Lan; Du, Yi; Ju, Furong; Ma, Shunxiang; Zhang, Shengxiang

    2016-01-01

    Paraoxon (POX) is one of the most toxic organophosphorus pesticides, but its toxic mechanisms associated with apoptosis remain unclear. The aim of this study was to investigate calcium-associated mechanisms in POX-induced apoptosis in EL4 cells. EL4 cells were exposed to POX for 0-16 h. EGTA was used to chelate Ca(2+ ) in extracellular medium, and heparin and procaine were used to inhibit Ca(2+ )efflux from the endoplasmic reticulum (ER). Z-ATAD-FMK was used to inhibit caspase-12 activity. The apoptotic rate assay, western blotting and immunocytochemistry (ICC) were used to reveal the mechanisms of POX-induced apoptosis. POX significantly increased the expression and activation of caspase-12 and caspase-3, enhanced expression of calpain 1 and calpain 2, and induced the release of cyt c, but did not change the expression of Grp 78. Inhibiting caspase-12 activity alleviated POX-induced upregulation of calpain 1 and caspase-3, promoted POX-induced upregulation of calpain 2, and reduced POX-induced cyt c release, suggesting that there was a cross-talk between the ER-associated pathway and mitochondria-associated apoptotic signals. Attenuating intracellular calcium concentration with EGTA, heparin or procaine decreased POX-induced upregulation of calpain 1, calpain 2, caspase-12 and caspase-3, and reduced POX-induced cyt c release. After pretreatment with EGTA or procaine, POX significantly promoted expression of Grp 78. Calcium played a key role in POX-induced apoptosis in EL4 cells by regulating both ER- and mitochondria-associated pathways. The cross-talk of ER- and mitochondria-associated pathways was accomplished through calcium signal.

  12. Neuroprotective effect of undecylenic acid extracted from Ricinus communis L. through inhibition of μ-calpain.

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    Lee, Eunyoung; Eom, Ji-Eun; Kim, Hye-Lin; Kang, Da-Hye; Jun, Kyu-Yeon; Jung, Duk Sang; Kwon, Youngjoo

    2012-05-12

    The key neuropathological features of Alzheimer's disease are abnormal deposition of Aβ plaques and insoluble Aβ peptides in extracellular brain and intracellular neurofibril tangles induced by abnormal tau hyperphosphorylation. μ-Calpain is one of the factors that bridge these Aβ- and hyperphosphorylated tau-mediated pathological pathways. Undecylenic acid (UDA), a naturally occurring unsaturated fatty acid, was discovered as a μ-calpain inhibitor by screening a chemical library using a substrate specific μ-calpain assay method. UDA inhibited Aβ oligomerization and Aβ fibrillation and reversed Aβ-induced neuronal cell death. In addition, UDA scavenged ROS and reversed the levels of proapoptotic proteins induced by ROS in SH-SY5Y cells. UDA inhibited μ-calpain activity with better potency than the known peptide-like μ-calpain inhibitor, MDL28170, in SH-SY5Y and HEK293T cells transfected with the catalytic subunit of μ-calpain. These results suggest that UDA is a novel non-peptide-like μ-calpain inhibitor with good cell permeability and potent neuroprotective effect. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Calpain Inhibition Reduces Axolemmal Leakage in Traumatic Axonal Injury

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    János Sándor

    2009-12-01

    Full Text Available Calcium-induced, calpain-mediated proteolysis (CMSP has recently been implicated to the pathogenesis of diffuse (traumatic axonal injury (TAI. Some studies suggested that subaxolemmal CMSP may contribute to axolemmal permeability (AP alterations observed in TAI. Seeking direct evidence for this premise we investigated whether subaxolemmal CMSP may contribute to axolemmal permeability alterations (APA and pre-injury calpain-inhibition could reduce AP in a rat model of TAI. Horseradish peroxidase (HRP, a tracer that accumulates in axons with APA was administered one hour prior to injury into the lateral ventricle; 30 min preinjury a single tail vein bolus injection of 30 mg/kg MDL-28170 (a calpain inhibitor or its vehicle was applied in Wistar rats exposed to impact acceleration brain injury. Histological detection of traumatically injured axonal segments accumulating HRP and statistical analysis revealed that pre-injury administration of the calpain inhibitor MDL-28170 significantly reduced the average length of HRP-labeled axonal segments. The axono-protective effect of pre-injury calpain inhibition recently demonstrated with classical immunohistochemical markers of TAI was further corroborated in this experiment; significant reduction of the length of labeled axons in the drug-treated rats implicate CMSP in the progression of altered AP in TAI.

  14. EspC, an Autotransporter Protein Secreted by Enteropathogenic Escherichia coli, Causes Apoptosis and Necrosis through Caspase and Calpain Activation, Including Direct Procaspase-3 Cleavage

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    Antonio Serapio-Palacios

    2016-06-01

    Full Text Available Enteropathogenic Escherichia coli (EPEC has the ability to antagonize host apoptosis during infection through promotion and inhibition of effectors injected by the type III secretion system (T3SS, but the total number of these effectors and the overall functional relationships between these effectors during infection are poorly understood. EspC produced by EPEC cleaves fodrin, paxillin, and focal adhesion kinase (FAK, which are also cleaved by caspases and calpains during apoptosis. Here we show the role of EspC in cell death induced by EPEC. EspC is involved in EPEC-mediated cell death and induces both apoptosis and necrosis in epithelial cells. EspC induces apoptosis through the mitochondrial apoptotic pathway by provoking (i a decrease in the expression levels of antiapoptotic protein Bcl-2, (ii translocation of the proapoptotic protein Bax from cytosol to mitochondria, (iii cytochrome c release from mitochondria to the cytoplasm, (iv loss of mitochondrial membrane potential, (v caspase-9 activation, (vi cleavage of procaspase-3 and (vii an increase in caspase-3 activity, (viii PARP proteolysis, and (ix nuclear fragmentation and an increase in the sub-G1 population. Interestingly, EspC-induced apoptosis was triggered through a dual mechanism involving both independent and dependent functions of its EspC serine protease motif, the direct cleavage of procaspase-3 being dependent on this motif. This is the first report showing a shortcut for induction of apoptosis by the catalytic activity of an EPEC protein. Furthermore, this atypical intrinsic apoptosis appeared to induce necrosis through the activation of calpain and through the increase of intracellular calcium induced by EspC. Our data indicate that EspC plays a relevant role in cell death induced by EPEC.

  15. Valsartan reduces AT1-AA-induced apoptosis through suppression oxidative stress mediated ER stress in endothelial progenitor cells.

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    Wang, Z-C; Qi, J; Liu, L-M; Li, J; Xu, H-Y; Liang, B; Li, B

    2017-03-01

    Valsartan has been reported to have the function of treating hypertension and improving the prognosis of patients. Many studies indicated that valsartan can also increase angiotensin II, andosterone and plasma renin activity (PRA). Autoantibodies against the angiotensin II type 1 receptor (AT1-AA) have been showed to increase reactive oxygen species (ROS) and calcium (Ca2+) and result in apoptosis in vascular smooth muscle cells. In this study, we attempted to explore the effect of valsartan on AT1-AA-induced apoptosis in endothelial progenitor cells. Endothelial progenitor cells (EPCs) were cultured. The cytotoxicity was determined by MTT assay. EPCs apoptosis was determined by DAPI staining and flow cytometry. Reactive oxygen species, intracellular calcium concentration and calpain activity were measured using Fluostar Omega Spectrofluorimeter. The expression of p-ERK, p-eIF-2a, CHOP, Bcl-2 and caspase-3 were detected by Western blot. MTT assays showed valsartan significantly inhibited AT1-AA- induced decline of the viability of EPCs. DAPI staining and flow cytometry results indicated valsartan inhibited AT1-AA-induced decline of the viability of EPCs via inhibiting AT1-AA-induced apoptosis. Furthermore, the increasing of reactive oxygen species, intracellular calcium and calpain activity induced by AT1-AA in EPCs were also recovered after pre-treated with valsartan. Meanwhile, the upregulation of p-ERK, p-eIF-2a and CHOP, downregulation of Bcl-2, and activation of Caspase-3 caused by AT1-AA were reversed after pre-incubated with valsartan. Valsartan could inhibit AT1-AA-induced apoptosis through inhibiting oxidative stress mediated ER stress in EPCs.

  16. Calpain: a molecule to induce AIF-mediated necroptosis in RGC-5 following elevated hydrostatic pressure

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    2014-01-01

    Background RIP3 (Receptor-interacting protein 3) pathway was mainly described as the molecular mechanism of necroptosis (programmed necrosis). But recently, non-RIP3 pathways were found to mediate necroptosis. We deliberate to investigate the effect of calpain, a molecule to induce necroptosis as reported (Cell Death Differ 19:245–256, 2012), in RGC-5 following elevated hydrostatic pressure. Results First, we identified the existence of necroptosis of RGC-5 after insult by using necrostatin-1 (Nec-1, necroptosis inhibitor) detected by flow cytometry. Immunofluorescence staining and western blot were used to detect the expression of calpain. Western blot analysis was carried out to describe the truncated AIF (tAIF) expression with or without pretreatment of ALLN (calpain activity inhibitor). Following elevated hydrostatic pressure, necroptotic cells pretreated with or without ALLN was stained by Annexin V/PI, The activity of calpain was also examined to confirm the inhibition effect of ALLN. The results showed that after cell injury there was an upregulation of calpain expression. Upon adding ALLN, the calpain activity was inhibited, and tAIF production was reduced upon injury along with the decreased number of necroptosis cells. Conclusion Our study found that calpain may induce necroptosis via tAIF-modulation in RGC-5 following elevated hydrostatic pressure. PMID:24884644

  17. Calpain Determines the Propensity of Adult Hippocampal Neural Stem Cells to Autophagic Cell Death Following Insulin Withdrawal.

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    Chung, Kyung Min; Park, Hyunhee; Jung, Seonghee; Ha, Shinwon; Yoo, Seung-Jun; Woo, Hanwoong; Lee, Hyang Ju; Kim, Seong Who; Kim, Eun-Kyoung; Moon, Cheil; Yu, Seong-Woon

    2015-10-01

    Programmed cell death (PCD) has significant effects on the function of neural stem cells (NSCs) during brain development and degeneration. We have previously reported that adult rat hippocampal neural stem (HCN) cells underwent autophagic cell death (ACD) rather than apoptosis following insulin withdrawal despite their intact apoptotic capabilities. Here, we report a switch in the mode of cell death in HCN cells with calpain as a critical determinant. In HCN cells, calpain 1 expression was barely detectable while calpain 2 was predominant. Inhibition of calpain in insulin-deprived HCN cells further augmented ACD. In contrast, expression of calpain 1 switched ACD to apoptosis. The proteasome inhibitor lactacystin blocked calpain 2 degradation and elevated the intracellular Ca(2+) concentration. In combination, these effects potentiated calpain activity and converted the mode of cell death to apoptosis. Our results indicate that low calpain activity, due to absence of calpain 1 and degradation of calpain 2, results in a preference for ACD over apoptosis in insulin-deprived HCN cells. On the other hand, conditions leading to high calpain activity completely switch the mode of cell death to apoptosis. This is the first report on the PCD mode switching mechanism in NSCs. The dynamic change in calpain activity through the proteasome-mediated modulation of the calpain and intracellular Ca(2+) levels may be the critical contributor to the demise of NSCs. Our findings provide a novel insight into the complex mechanisms interconnecting autophagy and apoptosis and their roles in the regulation of NSC death. © 2015 AlphaMed Press.

  18. Aspirin Has Antitumor Effects via Expression of Calpain Gene in Cervical Cancer Cells

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    Sang Koo Lee

    2008-01-01

    Full Text Available Aspirin and other nonsteroidal anti-inflammatory drugs show efficacy in the prevention of cancers. It is known that they can inhibit cyclooxygenases, and some studies have shown that they can induce apoptosis. Our objective in this study was to investigate the mechanism by which aspirin exerts its apoptosis effects in human cervical cancer HeLa cells. The effect of aspirin on the gene expression was studied by differential mRNA display RT-PCR. Among the isolated genes, mu-type calpain gene was upregulated by aspirin treatment. To examine whether calpain mediates the antitumor effects, HeLa cells were stably transfected with the mammalian expression vector pCR3.1 containing mu-type calpain cDNA (pCRCAL/HeLa, and tumor formations were measured in nude mice. When tumor burden was measured by day 49, HeLa cells and pCR/HeLa cells (vector control produced tumors of 2126 mm3 and 1638 mm3, respectively, while pCRCAL/HeLa cells produced markedly smaller tumor of 434 mm3 in volume. The caspase-3 activity was markedly elevated in pCRCAL/HeLa cells. The increased activity levels of caspase-3 in pCRCAL/HeLa cells, in parallel with the decreased tumor formation, suggest a correlation between caspase-3 activity and calpain protein. Therefore, we conclude that aspirin-induced calpain mediates an antitumor effect via caspase-3 in cervical cancer cells.

  19. Shigella entry unveils a calcium/calpain-dependent mechanism for inhibiting sumoylation

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    Lhocine, Nouara; Andrieux, Alexandra; Nigro, Giulia; Mounier, Joëlle

    2017-01-01

    Disruption of the sumoylation/desumoylation equilibrium is associated with several disease states such as cancer and infections, however the mechanisms regulating the global SUMO balance remain poorly defined. Here, we show that infection by Shigella flexneri, the causative agent of human bacillary dysentery, switches off host sumoylation during epithelial cell infection in vitro and in vivo and that this effect is mainly mediated by a calcium/calpain-induced cleavage of the SUMO E1 enzyme SAE2, thus leading to sumoylation inhibition. Furthermore, we describe a mechanism by which Shigella promotes its own invasion by altering the sumoylation state of RhoGDIα, a master negative regulator of RhoGTPase activity and actin polymerization. Together, our data suggest that SUMO modification is essential to restrain pathogenic bacterial entry by limiting cytoskeletal rearrangement induced by bacterial effectors. Moreover, these findings identify calcium-activated calpains as powerful modulators of cellular sumoylation levels with potentially broad implications in several physiological and pathological situations. PMID:29231810

  20. Calpain-GRIP Signaling in Nucleus Accumbens Core Mediates the Reconsolidation of Drug Reward Memory.

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    Liang, Jie; Li, Jia-Li; Han, Ying; Luo, Yi-Xiao; Xue, Yan-Xue; Zhang, Yàn; Zhang, Yán; Zhang, Li-Bo; Chen, Man-Li; Lu, Lin; Shi, Jie

    2017-09-13

    Exposure to drug-paired cues causes drug memories to be in a destabilized state and interfering with memory reconsolidation can inhibit relapse. Calpain, a calcium-dependent neutral cysteine protease, is involved in synaptic plasticity and the formation of long-term fear memory. However, the role of calpain in the reconsolidation of drug reward memory is still unknown. In the present study, using a conditioned place preference (CPP) model, we found that exposure to drug-paired contextual stimuli induced the activation of calpain and decreased the expression of glutamate receptor interacting protein 1 (GRIP1) in the nucleus accumbens (NAc) core, but not shell, of male rats. Infusions of calpain inhibitors in the NAc core immediately after retrieval disrupted the reconsolidation of cocaine/morphine cue memory and blocked retrieval-induced calpain activation and GRIP1 degradation. The suppressive effect of calpain inhibitors on the expression of drug-induced CPP lasted for at least 14 d. The inhibition of calpain without retrieval 6 h after retrieval or after exposure to an unpaired context had no effects on the expression of reward memory. Calpain inhibition after retrieval also decreased cocaine seeking in a self-administration model and this effect did not recover spontaneously after 28 d. Moreover, the knock-down of GRIP1 expression in the NAc core by lentivirus-mediated short-hairpin RNA blocked disruption of the reconsolidation of drug cue memories that was induced by calpain inhibitor treatment. These results suggest that calpain activity in the NAc core is crucial for the reconsolidation of drug reward memory via the regulation of GRIP1 expression. SIGNIFICANCE STATEMENT Calpain plays an important role in synaptic plasticity and long-term memory consolidation, however, its role in the reconsolidation of drug cue memory remains unknown. Using conditioned place preference and self-administration procedures, we found that exposure to drug-paired cues induced the

  1. Roles of calpain-calpastatin system (CCS) in human T cell activation.

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    Mikosik, Anna; Jasiulewicz, Aleksandra; Daca, Agnieszka; Henc, Izabella; Frąckowiak, Joanna E; Ruckemann-Dziurdzińska, Katarzyna; Foerster, Jerzy; Le Page, Aurelie; Bryl, Ewa; Fulop, Tamas; Witkowski, Jacek M

    2016-11-22

    The immune response is determined by the speed of the T cell reaction to antigens assured by a state of readiness for proliferation and cytokine secretion. Proliferation, apoptosis and motion of many cell types are controlled by cytoplasmic proteases - µ- and m-calpain - and their inhibitor calpastatin, together forming the "calpain-calpastatin system" (CCS), assumed to modify their targets only upon activation-dependent cytoplasmic Ca2+ increase. Contrastingly to this notion, using quantitative real time PCR and semiquantitative flow cytometry respectively, we show here that the CCS genes are constitutively expressed, and that both calpains are constitutively active in resting, circulating human CD4+ and CD8+ lymphocytes. Furthermore, we demonstrate that calpain inhibition in the resting T cells prevents them from proliferation in vitro and greatly reduces secretion of multiple cytokines. The mechanistic reason for these effects of calpain inhibition on T cell functions might be the demonstrated significant reduction of the expression of active (phosphorylated) upstream signalling molecules, including the phospholipase C gamma, p56Lck and NFκB, in the inhibitor-treated cells. Thus, we propose that the constitutive, self-regulatory calpain-calpastatin system activity in resting human T cells is a necessary, controlling element of their readiness for complex and effective response to antigenic challenge.

  2. Zinc finger protein 598 inhibits cell survival by promoting UV-induced apoptosis.

    Science.gov (United States)

    Yang, Qiaohong; Gupta, Romi

    2018-01-19

    UV is one of the major causes of DNA damage induced apoptosis. However, cancer cells adopt alternative mechanisms to evade UV-induced apoptosis. To identify factors that protect cancer cells from UV-induced apoptosis, we performed a genome wide short-hairpin RNA (shRNA) screen, which identified Zinc finger protein 598 (ZNF598) as a key regulator of UV-induced apoptosis. Here, we show that UV irradiation transcriptionally upregulates ZNF598 expression. Additionally, ZNF598 knockdown in cancer cells inhibited UV-induced apoptosis. In our study, we observe that ELK1 mRNA level as well as phosphorylated ELK1 levels was up regulated upon UV irradiation, which was necessary for UV irradiation induced upregulation of ZNF598. Cells expressing ELK1 shRNA were also resistant to UV-induced apoptosis, and phenocopy ZNF598 knockdown. Upon further investigation, we found that ZNF598 knockdown inhibits UV-induced apoptotic gene expression, which matches with decrease in percentage of annexin V positive cell. Similarly, ectopic expression of ZNF598 promoted apoptotic gene expression and also increased annexin V positive cells. Collectively, these results demonstrate that ZNF598 is a UV irradiation regulated gene and its loss results in resistance to UV-induced apoptosis.

  3. Arsenic induces cell apoptosis in cultured osteoblasts through endoplasmic reticulum stress

    International Nuclear Information System (INIS)

    Tang, C.-H.; Chiu, Y.-C.; Huang, C.-F.; Chen, Y.-W.; Chen, P.-C.

    2009-01-01

    Osteoporosis is characterized by low bone mass resulting from an imbalance between bone resorption by osteoclasts and bone formation by osteoblasts. Therefore, decreased bone formation by osteoblasts may lead to the development of osteoporosis, and rate of apoptosis is responsible for the regulation of bone formation. Arsenic (As) exists ubiquitously in our environment and increases the risk of neurotoxicity, liver injury, peripheral vascular disease and cancer. However, the effect of As on apoptosis of osteoblasts is mostly unknown. Here, we found that As induced cell apoptosis in osteoblastic cell lines (including hFOB, MC3T3-E1 and MG-63) and mouse bone marrow stromal cells (M2-10B4). As also induced upregulation of Bax and Bak, downregulation of Bcl-2 and dysfunction of mitochondria in osteoblasts. As also triggered endoplasmic reticulum (ER) stress, as indicated by changes in cytosolic-calcium levels. We found that As increased the expression and activities of glucose-regulated protein 78 (GRP78) and calpain. Transfection of cells with GRP78 or calpain siRNA reduced As-mediated cell apoptosis in osteoblasts. Therefore, our results suggest that As increased cell apoptosis in cultured osteoblasts and increased the risk of osteoporosis.

  4. Effects of ceramide inhibition on radiation-induced apoptosis in human leukemia MOLT-4 cells

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Eriko; Inanami, Osamu; Asanuma, Taketoshi; Kuwabara, Mikinori [Hokkaido Univ., Graduate School of Veterinary Medicine, Sapporo, Hokkaido (Japan)

    2006-03-15

    In the present study, using inhibitors of ceramide synthase (fumonisin B{sub 1}), 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 B{sub 1} 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. (author)

  5. Effects of ceramide inhibition on radiation-induced apoptosis in human leukemia MOLT-4 cells

    International Nuclear Information System (INIS)

    Takahashi, Eriko; Inanami, Osamu; Asanuma, Taketoshi; Kuwabara, Mikinori

    2006-01-01

    In the present study, using inhibitors of ceramide synthase (fumonisin B 1 ), 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 B 1 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. (author)

  6. Blockade of store-operated calcium entry alleviates ethanol-induced hepatotoxicity via inhibiting apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Ruibing [Department of Hepatology and Gastroenterology, Qilu Hospital of Shandong University, Jinan, Shandong Province 250012 (China); Yan, Lihui [Shandong Normal University, Jinan, Shandong Province 250012 (China); Luo, Zheng; Guo, Xiaolan [Department of Hepatology and Gastroenterology, Qilu Hospital of Shandong University, Jinan, Shandong Province 250012 (China); Yan, Ming, E-mail: ymylh@163.com [Department of Hepatology and Gastroenterology, Qilu Hospital of Shandong University, Jinan, Shandong Province 250012 (China)

    2015-08-15

    Extracellular Ca{sup 2+} influx has been suggested to play a role in ethanol-induced hepatocyte apoptosis and necrosis. Previous studies indicated that store-operated Ca{sup 2+} entry (SOCE) was involved in liver injury induced by ethanol in HepG2 cells. However, the mechanisms underlying liver injury caused by SOCE remain unclear. We aimed to investigate the effects and mechanism of SOCE inhibition on liver injury induced by ethanol in BRL cells and Sprague–Dawley rats. Our data demonstrated that ethanol (0–400 mM) dose-dependently increased hepatocyte injury and 100 mM ethanol significantly upregulated the mRNA and protein expression of SOC for at least 72 h in BRL cells. Blockade of SOCE by pharmacological inhibitors and sh-RNA knockdown of STIM1 and Orai1 attenuated intracellular Ca{sup 2+} overload, restored the mitochondrial membrane potential (MMP), decreased cytochrome C release and inhibited ethanol-induced apoptosis. STIM1 and Orai1 expression was greater in ethanol-treated than control rats, and the SOCE inhibitor corosolic acid ameliorated the histopathological findings and alanine transaminase and aspartate transaminase activity as well as decreased cytochrome C release and inhibited alcohol-induced cell apoptosis. These findings suggest that SOCE blockade could alleviate alcohol-induced hepatotoxicity via inhibiting apoptosis. SOCE might be a useful therapeutic target in alcoholic liver diseases. - Highlights: • Blockade of SOCE alleviated overload of Ca{sup 2+} and hepatotoxicity after ethanol application. • Blockade of SOCE inhibited mitochondrial apoptosis after ethanol application. • SOCE might be a useful therapeutic target in alcoholic liver diseases.

  7. PI3K inhibition enhances doxorubicin-induced apoptosis in sarcoma cells.

    Directory of Open Access Journals (Sweden)

    Diana Marklein

    Full Text Available We searched for a drug capable of sensitization of sarcoma cells to doxorubicin (DOX. We report that the dual PI3K/mTOR inhibitor PI103 enhances the efficacy of DOX in several sarcoma cell lines and interacts with DOX in the induction of apoptosis. PI103 decreased the expression of MDR1 and MRP1, which resulted in DOX accumulation. However, the enhancement of DOX-induced apoptosis was unrelated to DOX accumulation. Neither did it involve inhibition of mTOR. Instead, the combination treatment of DOX plus PI103 activated Bax, the mitochondrial apoptosis pathway, and caspase 3. Caspase 3 activation was also observed in xenografts of sarcoma cells in nude mice upon combination of DOX with the specific PI3K inhibitor GDC-0941. Although the increase in apoptosis did not further impact on tumor growth when compared to the efficient growth inhibition by GDC-0941 alone, these findings suggest that inhibition of PI3K may improve DOX-induced proapoptotic effects in sarcoma. Taken together with similar recent studies of neuroblastoma- and glioblastoma-derived cells, PI3K inhibition seems to be a more general option to sensitize tumor cells to anthracyclines.

  8. Distinct regulatory functions of calpain 1 and 2 during neural stem cell self-renewal and differentiation.

    Directory of Open Access Journals (Sweden)

    Daniela M Santos

    Full Text Available Calpains are calcium regulated cysteine proteases that have been described in a wide range of cellular processes, including apoptosis, migration and cell cycle regulation. In addition, calpains have been implicated in differentiation, but their impact on neural differentiation requires further investigation. Here, we addressed the role of calpain 1 and calpain 2 in neural stem cell (NSC self-renewal and differentiation. We found that calpain inhibition using either the chemical inhibitor calpeptin or the endogenous calpain inhibitor calpastatin favored differentiation of NSCs. This effect was associated with significant changes in cell cycle-related proteins and may be regulated by calcium. Interestingly, calpain 1 and calpain 2 were found to play distinct roles in NSC fate decision. Calpain 1 expression levels were higher in self-renewing NSC and decreased with differentiation, while calpain 2 increased throughout differentiation. In addition, calpain 1 silencing resulted in increased levels of both neuronal and glial markers, β-III Tubulin and glial fibrillary acidic protein (GFAP. Calpain 2 silencing elicited decreased levels of GFAP. These results support a role for calpain 1 in repressing differentiation, thus maintaining a proliferative NSC pool, and suggest that calpain 2 is involved in glial differentiation.

  9. GSK-3beta inhibition enhances sorafenib-induced apoptosis in melanoma cell lines.

    Science.gov (United States)

    Panka, David J; Cho, Daniel C; Atkins, Michael B; Mier, James W

    2008-01-11

    Glycogen synthase kinase-3beta (GSK-3beta) can participate in the induction of apoptosis or, alternatively, provide a survival signal that minimizes cellular injury. We previously demonstrated that the multikinase inhibitor sorafenib induces apoptosis in melanoma cell lines. In this report, we show that sorafenib activates GSK-3beta in multiple subcellular compartments and that this activation undermines the lethality of the drug. Pharmacologic inhibition and/or down-modulation of the kinase enhances sorafenib-induced apoptosis as determined by propidium iodide staining and by assessing the mitochondrial release of apoptosis-inducing factor and Smac/DIABLO. Conversely, the forced expression of a constitutively active form of the enzyme (GSK-3beta(S9A)) protects the cells from the apoptotic effects of the drug. This protective effect is associated with a marked increase in basal levels of Bcl-2, Bcl-x(L), and survivin and a diminution in the degree to which these anti-apoptotic proteins are down-modulated by sorafenib exposure. Sorafenib down-modulates the pro-apoptotic Bcl-2 family member Noxa in cells with high constitutive GSK-3beta activity. Pharmacologic inhibition of GSK-3beta prevents the disappearance of Noxa induced by sorafenib and enhances the down-modulation of Mcl-1. Down-modulation of Noxa largely eliminates the enhancing effect of GSK-3 inhibition on sorafenib-induced apoptosis. These data provide a strong rationale for the use of GSK-3beta inhibitors as adjuncts to sorafenib treatment and suggest that preservation of Noxa may contribute to their efficacy.

  10. Hippocampal Cortactin Levels are Reduced Following Spatial Working Memory Formation, an Effect Blocked by Chronic Calpain Inhibition.

    Science.gov (United States)

    Olson, Mikel L; Ingebretson, Anna E; Harmelink, Katherine M

    2015-06-19

    The mechanism by which the hippocampus facilitates declarative memory formation appears to involve, among other things, restructuring of the actin cytoskeleton within neuronal dendrites. One protein involved in this process is cortactin, which is an important link between extracellular signaling and cytoskeletal reorganization. In this paper, we demonstrate that total hippocampal cortactin, as well as Y421-phosphorylated cortactin are transiently reduced following spatial working memory formation in the radial arm maze (RAM). Because cortactin is a substrate of the cysteine protease calpain, we also assessed the effect of chronic calpain inhibition on RAM performance and cortactin expression. Calpain inhibition impaired spatial working memory and blocked the reduction in hippocampal cortactin levels following RAM training. These findings add to a growing body of research implicating cortactin and calpain in hippocampus-dependent memory formation.

  11. Smad7 induces tumorigenicity by blocking TGF-beta-induced growth inhibition and apoptosis.

    Science.gov (United States)

    Halder, Sunil K; Beauchamp, R Daniel; Datta, Pran K

    2005-07-01

    Smad proteins play a key role in the intracellular signaling of the transforming growth factor beta (TGF-beta) superfamily of extracellular polypeptides that initiate signaling to regulate a wide variety of biological processes. The inhibitory Smad, Smad7, has been shown to function as intracellular antagonists of TGF-beta family signaling and is upregulated in several cancers. To determine the effect of Smad7-mediated blockade of TGF-beta signaling, we have stably expressed Smad7 in a TGF-beta-sensitive, well-differentiated, and non-tumorigenic cell line, FET, that was derived from human colon adenocarcinoma. Smad7 inhibits TGF-beta-induced transcriptional responses by blocking complex formation between Smad 2/3 and Smad4. While Smad7 has no effect on TGF-beta-induced activation of p38 MAPK and ERK, it blocks the phosphorylation of Akt by TGF-beta and enhances TGF-beta-induced phosphorylation of c-Jun. FET cells expressing Smad7 show anchorage-independent growth and enhance tumorigenicity in athymic nude mice. Smad7 blocks TGF-beta-induced growth inhibition by preventing TGF-beta-induced G1 arrest. Smad7 inhibits TGF-beta-mediated downregulation of c-Myc, CDK4, and Cyclin D1, and suppresses the expression of p21(Cip1). As a result, Smad7 inhibits TGF-beta-mediated downregulation of Rb phosphorylation. Furthermore, Smad7 inhibits the apoptosis of these cells. Together, Smad7 may increase the tumorigenicity of FET cells by blocking TGF-beta-induced growth inhibition and by inhibiting apoptosis. Thus, this study provides a mechanism by which a portion of human colorectal tumors may become refractory to tumor-suppressive actions of TGF-beta that might result in increased tumorigenicity.

  12. Linear ubiquitin chain induces apoptosis and inhibits tumor growth.

    Science.gov (United States)

    Qin, Zhoushuai; Jiang, Wandong; Wang, Guifen; Sun, Ying; Xiao, Wei

    2018-01-01

    Ubiquitination of proliferating cell nuclear antigen (PCNA) plays an important role in DNA damage response. Ectopic expression of PCNA fused at either terminus with ubiquitin (Ub) lacking two C-terminal glycine residues induces translesion DNA synthesis which resembles synthesis mediated by PCNA monoubiquitination. PCNA fused with Ub containing the C-terminal Gly residues at the C-terminus can be further polyubiquitinated in a Gly-dependent manner, which inhibits cell proliferation and induces ATR-dependent replication checkpoint. In this study, we surprisingly found that PCNA fused to a head-to-tail linear Ub chain induces apoptosis in a Ub chain length-dependent manner. Further investigation revealed that the apoptotic effect is actually induced by the linear Ub chain independently from PCNA, as the Ub chain fused to GFP or an epitope tag still efficiently induces apoptosis. It is revealed that the artificial linear Ub chain differs from endogenously encoded linear Ub chains in that its Ubs contain a Ub-G76S substitution, making the Ub chain resistant to cleavage by deubiquitination enzymes. We demonstrated in this study that ectopic expression of the artificial Ub chain alone in cultured human cancer cells is sufficient to inhibit tumor growth in a xenograft mouse model, making the linear Ub chain a putative anti-cancer agent.

  13. Hippocampal Cortactin Levels are Reduced Following Spatial Working Memory Formation, an Effect Blocked by Chronic Calpain Inhibition

    Directory of Open Access Journals (Sweden)

    Mikel L. Olson

    2015-06-01

    Full Text Available The mechanism by which the hippocampus facilitates declarative memory formation appears to involve, among other things, restructuring of the actin cytoskeleton within neuronal dendrites. One protein involved in this process is cortactin, which is an important link between extracellular signaling and cytoskeletal reorganization. In this paper, we demonstrate that total hippocampal cortactin, as well as Y421-phosphorylated cortactin are transiently reduced following spatial working memory formation in the radial arm maze (RAM. Because cortactin is a substrate of the cysteine protease calpain, we also assessed the effect of chronic calpain inhibition on RAM performance and cortactin expression. Calpain inhibition impaired spatial working memory and blocked the reduction in hippocampal cortactin levels following RAM training. These findings add to a growing body of research implicating cortactin and calpain in hippocampus-dependent memory formation.

  14. Statins induce apoptosis in rat and human myotube cultures by inhibiting protein geranylgeranylation but not ubiquinone

    International Nuclear Information System (INIS)

    Johnson, Timothy E.; Zhang, Xiaohua; Bleicher, Kimberly B.; Dysart, Gary; Loughlin, Amy F.; Schaefer, William H.; Umbenhauer, Diane R.

    2004-01-01

    Statins are widely used to treat lipid disorders. These drugs are safe and well tolerated; however, in <1% of patients, myopathy and/or rhabdomyolysis can develop. To better understand the mechanism of statin-induced myopathy, we examined the ability of structurally distinct statins to induce apoptosis in an optimized rat myotube model. Compound A (a lactone) and Cerivastatin (an open acid) induced apoptosis, as measured by TUNEL and active caspase 3 staining, in a concentration- and time-dependent manner. In contrast, an epimer of Compound A (Compound B) exhibited a much weaker apoptotic response. Statin-induced apoptosis was completely prevented by mevalonate or geranylgeraniol, but not by farnesol. Zaragozic acid A, a squalene synthase inhibitor, caused no apoptosis on its own and had no effect on Compound-A-induced myotoxicity, suggesting the apoptosis was not a result of cholesterol synthesis inhibition. The geranylgeranyl transferase inhibitors GGTI-2133 and GGTI-2147 caused apoptosis in myotubes; the farnesyl transferase inhibitor FTI-277 exhibited a much weaker effect. In addition, the prenylation of rap1a, a geranylgeranylated protein, was inhibited by Compound A in myotubes at concentrations that induced apoptosis. A similar statin-induced apoptosis profile was seen in human myotube cultures but primary rat hepatocytes were about 200-fold more resistant to statin-induced apoptosis. Although the statin-induced hepatotoxicity could be attenuated with mevalonate, no effect was found with either geranylgeraniol or farnesol. In studies assessing ubiquinone levels after statin treatment in rat and human myotubes, there was no correlation between ubiquinone levels and apoptosis. Taken together, these observations suggest that statins cause apoptosis in myotube cultures in part by inhibiting the geranylgeranylation of proteins, but not by suppressing ubiquinone concentration. Furthermore, the data from primary hepatocytes suggests a cell-type differential

  15. Catalase inhibits ionizing radiation-induced apoptosis in hematopoietic stem and progenitor cells.

    Science.gov (United States)

    Xiao, Xia; Luo, Hongmei; Vanek, Kenneth N; LaRue, Amanda C; Schulte, Bradley A; Wang, Gavin Y

    2015-06-01

    Hematologic toxicity is a major cause of mortality in radiation emergency scenarios and a primary side effect concern in patients undergoing chemo-radiotherapy. Therefore, there is a critical need for the development of novel and more effective approaches to manage this side effect. Catalase is a potent antioxidant enzyme that coverts hydrogen peroxide into hydrogen and water. In this study, we evaluated the efficacy of catalase as a protectant against ionizing radiation (IR)-induced toxicity in hematopoietic stem and progenitor cells (HSPCs). The results revealed that catalase treatment markedly inhibits IR-induced apoptosis in murine hematopoietic stem cells and hematopoietic progenitor cells. Subsequent colony-forming cell and cobble-stone area-forming cell assays showed that catalase-treated HSPCs can not only survive irradiation-induced apoptosis but also have higher clonogenic capacity, compared with vehicle-treated cells. Moreover, transplantation of catalase-treated irradiated HSPCs results in high levels of multi-lineage and long-term engraftments, whereas vehicle-treated irradiated HSPCs exhibit very limited hematopoiesis reconstituting capacity. Mechanistically, catalase treatment attenuates IR-induced DNA double-strand breaks and inhibits reactive oxygen species. Unexpectedly, we found that the radioprotective effect of catalase is associated with activation of the signal transducer and activator of transcription 3 (STAT3) signaling pathway and pharmacological inhibition of STAT3 abolishes the protective activity of catalase, suggesting that catalase may protect HSPCs against IR-induced toxicity via promoting STAT3 activation. Collectively, these results demonstrate a previously unrecognized mechanism by which catalase inhibits IR-induced DNA damage and apoptosis in HSPCs.

  16. Quercetogetin protects against cigarette smoke extract-induced apoptosis in epithelial cells by inhibiting mitophagy.

    Science.gov (United States)

    Son, Eun Suk; Kim, Se-Hee; Ryter, Stefan W; Yeo, Eui-Ju; Kyung, Sun Young; Kim, Yu Jin; Jeong, Sung Hwan; Lee, Chang Soo; Park, Jeong-Woong

    2018-04-01

    Recent studies demonstrate that the autophagy-dependent turnover of mitochondria (mitophagy) mediates pulmonary epithelial cell death in response to cigarette smoke extract (CSE) exposure, and contributes to emphysema development in vivo during chronic cigarette smoke (CS)-exposure, although the underlying mechanisms remain unclear. Here, we investigated the role of mitophagy in regulating apoptosis in CSE-exposed human lung bronchial epithelial cells. Furthermore, we investigated the potential of the polymethoxylated flavone antioxidant quercetogetin (QUE) to inhibit CSE-induced mitophagy-dependent apoptosis. Our results demonstrate that CSE induces mitophagy in epithelial cells via mitochondrial dysfunction, and causes increased expression levels of the mitophagy-regulator protein PTEN-induced putative kinase-1 (PINK1) and the mitochondrial fission protein dynamin-1-like protein (DRP-1). CSE induced epithelial cell death and increased the expression of the apoptosis-related proteins cleaved caspase-3, -8 and -9. Caspase-3 activity was significantly increased in Beas-2B cells exposed to CSE, and decreased by siRNA-dependent knockdown of DRP-1. Treatment of epithelial cells with QUE inhibited CSE-induced mitochondrial dysfunction and mitophagy by inhibiting phospho (p)-DRP-1 and PINK1 expression. QUE suppressed mitophagy-dependent apoptosis by inhibiting the expression of cleaved caspase-3, -8 and -9 and downregulating caspase activity in human bronchial epithelial cells. These findings suggest that QUE may serve as a potential therapeutic in CS-induced pulmonary diseases. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. Effect and mechanism of calpains on pediatric lobar pneumonia.

    Science.gov (United States)

    Yin, Genquan; Zeng, Qiang; Zhao, Haijin; Wu, Peiqiong; Cai, Shaoxi; Deng, Li; Jiang, Wenhui

    2017-07-04

    Lobar pneumonia, one of the community-acquired pneumonia (CAP), is a common pediatric low respiratory tract infection. Calpains are Ca 2+ -activated cysteine proteases whose activation mechanism is elusive. The present study was undertaken to detect the role and mechanism of calpains in pediatric lobar pneumonia. The human acute lung infection model (ALIM) was constructed and infected by Streptococcus. Enzyme-linked immunosorbent assay (ELISA) was used to measure interleukin (IL)-6, IL-8 and tumor necrosis factor (TNF)-α. We observed the lactate dehydrogenase (LDH) release, calpains activity and calpain inhibitor effects in ALIM. The expression of proliferating cell nuclear antigen (PCNA) protein was quantified by western blotting. Then the effects of calpain 1 and 2 knockdown on expressions of inflammation factors and PCNA protein, LDH release and apoptosis were evaluated in lung MRC-5 cells. In constructed ALIM, expressions of IL-6 (P < 0.01), IL-8 (P < 0.01), TNF-α (P < 0.05) and PCNA protein (P < 0.05) were significantly reduced by the calpain inhibitor. Expressions of IL-6, IL-8, TNF-α, PCNA protein and relative LDH release were statistically reduced by the small interfering (si) RNA-calpain 1 and 2 in MRC-5 cells (P < 0.05). Calpains silence increased apoptotic cells from 5% (negative control) to more than 20% in MRC-5 cells. The present study suggests that calpains possess a significant effect on inflammations, cell proliferation and apoptosis. Suppression of calpains may provide a potential therapeutic target of lobar pneumonia.

  18. VCC-1 over-expression inhibits cisplatin-induced apoptosis in HepG2 cells

    International Nuclear Information System (INIS)

    Zhou, Zhitao; Lu, Xiao; Zhu, Ping; Zhu, Wei; Mu, Xia; Qu, Rongmei; Li, Ming

    2012-01-01

    Highlights: ► VCC-1 is hypothesized to be associated with carcinogenesis. ► Levels of VCC-1 are increased significantly in HCC. ► Over-expression of VCC-1 could promotes cellular proliferation rate. ► Over-expression of VCC-1 inhibit the cisplatin-provoked apoptosis in HepG2 cells. ► VCC-1 plays an important role in control the tumor growth and apoptosis. -- Abstract: Vascular endothelial growth factor-correlated chemokine 1 (VCC-1), a recently described chemokine, is hypothesized to be associated with carcinogenesis. However, the molecular mechanisms by which aberrant VCC-1 expression determines poor outcomes of cancers are unknown. In this study, we found that VCC-1 was highly expressed in hepatocellular carcinoma (HCC) tissue. It was also associated with proliferation of HepG2 cells, and inhibition of cisplatin-induced apoptosis of HepG2 cells. Conversely, down-regulation of VCC-1 in HepG2 cells increased cisplatin-induced apoptosis of HepG2 cells. In summary, these results suggest that VCC-1 is involved in cisplatin-induced apoptosis of HepG2 cells, and also provides some evidence for VCC-1 as a potential cellular target for chemotherapy.

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

    International Nuclear Information System (INIS)

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

    2012-01-01

    Highlights: ► cAMP blocks cell death induced by TNF and actinomycin D in cultured hepatocytes. ► cAMP blocks NF-κB activation induced by TNF and actinomycin D. ► cAMP blocks DISC formation following TNF and actinomycin D exposure. ► cAMP blocks TNF signaling at a proximal step. -- Abstract: 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharjee, Rajesh [Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA 15213 (United States); Xiang, Wenpei [Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA 15213 (United States); Family Planning Research Institute, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, People' s Republic of China (China); Wang, Yinna [Vascular Medicine Institute, University of Pittsburgh School of Medicine, 10051-5A BST 3, 3501 Fifth Avenue, Pittsburgh, PA 15261 (United States); Zhang, Xiaoying [Department of Medicine/Endocrinology Division, University of Pittsburgh Medical Center, 200 Lothrop St., Pittsburgh, PA 15213 (United States); Billiar, Timothy R., E-mail: billiartr@upmc.edu [Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA 15213 (United States)

    2012-06-22

    Highlights: Black-Right-Pointing-Pointer cAMP blocks cell death induced by TNF and actinomycin D in cultured hepatocytes. Black-Right-Pointing-Pointer cAMP blocks NF-{kappa}B activation induced by TNF and actinomycin D. Black-Right-Pointing-Pointer cAMP blocks DISC formation following TNF and actinomycin D exposure. Black-Right-Pointing-Pointer cAMP blocks TNF signaling at a proximal step. -- Abstract: Tumor necrosis factor {alpha} (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

  1. The zinc fingers of the Small Optic Lobes (SOL) calpain bind polyubiquitin.

    Science.gov (United States)

    Hastings, Margaret H; Qiu, Alvin; Zha, Congyao; Farah, Carole A; Mahdid, Yacine; Ferguson, Larissa; Sossin, Wayne S

    2018-05-28

    The Small Optic Lobes (SOL) calpain is a highly conserved member of the calpain family expressed in the nervous system. A dominant negative form of the SOL calpain inhibited consolidation of one form of synaptic plasticity, non-associative facilitation, in sensory-motor neuronal cultures in Aplysia, presumably by inhibiting cleavage of protein kinase Cs (PKCs) into constitutively active protein kinase Ms (PKMs) (Hu et al, 2017a). SOL calpains have a conserved set of 5-6 N-terminal zinc fingers. Bioinformatic analysis suggests that these zinc fingers could bind to ubiquitin. In this study, we show that both the Aplysia and mouse SOL calpain (also known as Calpain 15) zinc fingers bind ubiquitinated proteins, and we confirm that Aplysia SOL binds poly- but not mono or di-ubiquitin. No specific zinc finger is required for polyubiquitin binding. Neither polyubiquitin nor calcium was sufficient to induce purified Aplysia SOL calpain to autolyse or to cleave the atypical PKC to PKM in vitro. In Aplysia, overexpression of the atypical PKC in sensory neurons leads to an activity-dependent cleavage event and an increase in nuclear ubiquitin staining. Activity-dependent cleavage is partially blocked by a dominant negative SOL calpain, but not by a dominant negative classical calpain. The cleaved PKM was stabilized by the dominant negative classical calpain and destabilized by a dominant negative form of the PKM stabilizing proteinKIdney/BRAin protein(KIBRA). These studies provide new insight into SOL calpain's function and regulation. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  2. Eliminating Legionella by inhibiting BCL-XL to induce macrophage apoptosis.

    Science.gov (United States)

    Speir, Mary; Lawlor, Kate E; Glaser, Stefan P; Abraham, Gilu; Chow, Seong; Vogrin, Adam; Schulze, Keith E; Schuelein, Ralf; O'Reilly, Lorraine A; Mason, Kylie; Hartland, Elizabeth L; Lithgow, Trevor; Strasser, Andreas; Lessene, Guillaume; Huang, David C S; Vince, James E; Naderer, Thomas

    2016-02-24

    Human pathogenic Legionella replicate in alveolar macrophages and cause a potentially lethal form of pneumonia known as Legionnaires' disease(1). Here, we have identified a host-directed therapeutic approach to eliminate intracellular Legionella infections. We demonstrate that the genetic deletion, or pharmacological inhibition, of the host cell pro-survival protein BCL-XL induces intrinsic apoptosis of macrophages infected with virulent Legionella strains, thereby abrogating Legionella replication. BCL-XL is essential for the survival of Legionella-infected macrophages due to bacterial inhibition of host-cell protein synthesis, resulting in reduced levels of the short-lived, related BCL-2 pro-survival family member, MCL-1. Consequently, a single dose of a BCL-XL-targeted BH3-mimetic therapy, or myeloid cell-restricted deletion of BCL-XL, limits Legionella replication and prevents lethal lung infections in mice. These results indicate that repurposing BH3-mimetic compounds, originally developed to induce cancer cell apoptosis, may have efficacy in treating Legionnaires' and other diseases caused by intracellular microbes.

  3. Lansoprazole induces apoptosis of breast cancer cells through inhibition of intracellular proton extrusion

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Shangrong; Wang, Yifan; Li, Shu Jie, E-mail: shujieli@nankai.edu.cn

    2014-06-13

    Highlights: • Lansoprazole (LPZ) induces cell apoptosis in breast cancer cells. • LPZ markedly inhibits intracellular proton extrusion. • LPZ induces an increase in intracellular ATP level, lysosomal alkalinization and ROS accumulation. - Abstract: The increased glycolysis and proton secretion in tumors is proposed to contribute to the proliferation and invasion of cancer cells during the process of tumorigenesis and metastasis. Here, treatment of human breast cancer cells with proton pump inhibitor (PPI) lansoprazole (LPZ) induces cell apoptosis in a dose-dependent manner. In the implantation of the MDA-MB-231 xenografts in nude mice, administration of LPZ significantly inhibits tumorigenesis and induces large-scale apopotosis of tumor cells. LPZ markedly inhibits intracellular proton extrusion, induces an increase in intracellular ATP level, lysosomal alkalinization and accumulation of reactive oxygen species (ROS) in breast cancer cells. The ROS scavenger N-acetyl-L-cysteine (NAC) and diphenyleneiodonium (DPI), a specific pharmacological inhibitor of NADPH oxidases (NOX), significantly abolish LPZ-induced ROS accumulation in breast cancer cells. Our results suggested that LPZ may be used as a new therapeutic drug for breast tumor.

  4. Lansoprazole induces apoptosis of breast cancer cells through inhibition of intracellular proton extrusion

    International Nuclear Information System (INIS)

    Zhang, Shangrong; Wang, Yifan; Li, Shu Jie

    2014-01-01

    Highlights: • Lansoprazole (LPZ) induces cell apoptosis in breast cancer cells. • LPZ markedly inhibits intracellular proton extrusion. • LPZ induces an increase in intracellular ATP level, lysosomal alkalinization and ROS accumulation. - Abstract: The increased glycolysis and proton secretion in tumors is proposed to contribute to the proliferation and invasion of cancer cells during the process of tumorigenesis and metastasis. Here, treatment of human breast cancer cells with proton pump inhibitor (PPI) lansoprazole (LPZ) induces cell apoptosis in a dose-dependent manner. In the implantation of the MDA-MB-231 xenografts in nude mice, administration of LPZ significantly inhibits tumorigenesis and induces large-scale apopotosis of tumor cells. LPZ markedly inhibits intracellular proton extrusion, induces an increase in intracellular ATP level, lysosomal alkalinization and accumulation of reactive oxygen species (ROS) in breast cancer cells. The ROS scavenger N-acetyl-L-cysteine (NAC) and diphenyleneiodonium (DPI), a specific pharmacological inhibitor of NADPH oxidases (NOX), significantly abolish LPZ-induced ROS accumulation in breast cancer cells. Our results suggested that LPZ may be used as a new therapeutic drug for breast tumor

  5. Autophagy fails to prevent glucose deprivation/glucose reintroduction-induced neuronal death due to calpain-mediated lysosomal dysfunction in cortical neurons.

    Science.gov (United States)

    Gerónimo-Olvera, Cristian; Montiel, Teresa; Rincon-Heredia, Ruth; Castro-Obregón, Susana; Massieu, Lourdes

    2017-06-29

    Autophagy is triggered during nutrient and energy deprivation in a variety of cells as a homeostatic response to metabolic stress. In the CNS, deficient autophagy has been implicated in neurodegenerative diseases and ischemic brain injury. However, its role in hypoglycemic damage is poorly understood and the dynamics of autophagy during the hypoglycemic and the glucose reperfusion periods, has not been fully described. In the present study, we analyzed the changes in the content of the autophagy proteins BECN1, LC3-II and p62/SQSTM1 by western blot, and autophagosome formation was followed through time-lapse experiments, during glucose deprivation (GD) and glucose reintroduction (GR) in cortical cultures. According to the results, autophagosome formation rapidly increased during GD, and was followed by an active autophagic flux early after glucose replenishment. However, cells progressively died during GR and autophagy inhibition reduced neuronal death. Neurons undergoing apoptosis during GR did not form autophagosomes, while those surviving up to late GR showed autophagosomes. Calpain activity strongly increased during GR and remained elevated during progressive neuronal death. Its activation led to the cleavage of LAMP2 resulting in lysosome membrane permeabilization (LMP) and release of cathepsin B to the cytosol. Calpain inhibition prevented LMP and increased the number of neurons containing lysosomes and autophagosomes increasing cell viability. Taken together, the present results suggest that calpain-mediated lysosome dysfunction during GR turns an adaptive autophagy response to energy stress into a defective autophagy pathway, which contributes to neuronal death. In these conditions, autophagy inhibition results in the improvement of cell survival.

  6. Valsartan Protects Against Contrast-Induced Acute Kidney Injury in Rats by Inhibiting Endoplasmic Reticulum Stress-Induced Apoptosis.

    Science.gov (United States)

    Sun, Yan; Peng, Ping-An; Ma, Yue; Liu, Xiao-Li; Yu, Yi; Jia, Shuo; Xu, Xiao-Han; Wu, Si-Jing; Zhou, Yu-Jie

    2017-01-01

    Contrast-induced acute kidney injury (CI-AKI) is a serious complication of the administration of iodinated contrast media (CM) for diagnostic and interventional cardiovascular procedures and is associated with substantial morbidity and mortality. While the preventative measures can mitigate the risk of CI-AKI, there remains a need for novel and effective therapeutic approaches. The pathogenesis of CI-AKI is complex and not completely understood. CM-induced renal tubular cell apoptosis caused by the activation of endoplasmic reticulum (ER) stress is involved in CIAKI. We previously demonstrated that valsartan alleviated CM-induced human renal tubular cell apoptosis by inhibiting ER stress in vitro. However, the nephroprotective effect of valsartan on CI-AKI in vivo has not been investigated. Therefore, the aim of this study was to explore the protective effect of valsartan in a rat model of CI-AKI by measuring the amelioration of renal damage and the changes in ER stressrelated biomarkers. Our results showed that the radiocontrast agent meglumine diatrizoate caused significant renal insufficiency, renin-angiotensin system (RAS) activation, and renal tubular apoptosis by triggering ER stress through activation of glucose-regulated protein 78 (GRP78), activating transcription factor 4 (ATF4), caspase 12, CCAAT/enhancer-binding protein-homologous protein (CHOP) and c-Jun N-terminal protein kinase (JNK) (Pvalsartan significantly alleviated renal dysfunction, pathological injury, and apoptosis along with the inhibition of ER stressrelated biomarkers (PValsartan could protect against meglumine diatrizoate-induced kidney injury in rats by inhibiting the ER stress-induced apoptosis, making it a promising strategy for preventing CI-AKI. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  7. Belinostat-induced apoptosis and growth inhibition in pancreatic cancer cells involve activation of TAK1-AMPK signaling axis

    International Nuclear Information System (INIS)

    Wang, Bing; Wang, Xin-bao; Chen, Li-yu; Huang, Ling; Dong, Rui-zen

    2013-01-01

    Highlights: •Belinostat activates AMPK in cultured pancreatic cancer cells. •Activation of AMPK is important for belinostat-induced cytotoxic effects. •ROS and TAK1 are involved in belinostat-induced AMPK activation. •AMPK activation mediates mTOR inhibition by belinostat. -- Abstract: Pancreatic cancer accounts for more than 250,000 deaths worldwide each year. Recent studies have shown that belinostat, a novel pan histone deacetylases inhibitor (HDACi) induces apoptosis and growth inhibition in pancreatic cancer cells. However, the underlying mechanisms are not fully understood. In the current study, we found that AMP-activated protein kinase (AMPK) activation was required for belinostat-induced apoptosis and anti-proliferation in PANC-1 pancreatic cancer cells. A significant AMPK activation was induced by belinostat in PANC-1 cells. Inhibition of AMPK by RNAi knockdown or dominant negative (DN) mutation significantly inhibited belinostat-induced apoptosis in PANC-1 cells. Reversely, AMPK activator AICAR and A-769662 exerted strong cytotoxicity in PANC-1 cells. Belinostat promoted reactive oxygen species (ROS) production in PANC-1 cells, increased ROS induced transforming growth factor-β-activating kinase 1 (TAK1)/AMPK association to activate AMPK. Meanwhile, anti-oxidants N-Acetyl-Cysteine (NAC) and MnTBAP as well as TAK1 shRNA knockdown suppressed belinostat-induced AMPK activation and PANC-1 cell apoptosis. In conclusion, we propose that belinostat-induced apoptosis and growth inhibition require the activation of ROS-TAK1-AMPK signaling axis in cultured pancreatic cancer cells

  8. Belinostat-induced apoptosis and growth inhibition in pancreatic cancer cells involve activation of TAK1-AMPK signaling axis

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Bing, E-mail: wangbin69@yahoo.com; Wang, Xin-bao; Chen, Li-yu; Huang, Ling; Dong, Rui-zen

    2013-07-19

    Highlights: •Belinostat activates AMPK in cultured pancreatic cancer cells. •Activation of AMPK is important for belinostat-induced cytotoxic effects. •ROS and TAK1 are involved in belinostat-induced AMPK activation. •AMPK activation mediates mTOR inhibition by belinostat. -- Abstract: Pancreatic cancer accounts for more than 250,000 deaths worldwide each year. Recent studies have shown that belinostat, a novel pan histone deacetylases inhibitor (HDACi) induces apoptosis and growth inhibition in pancreatic cancer cells. However, the underlying mechanisms are not fully understood. In the current study, we found that AMP-activated protein kinase (AMPK) activation was required for belinostat-induced apoptosis and anti-proliferation in PANC-1 pancreatic cancer cells. A significant AMPK activation was induced by belinostat in PANC-1 cells. Inhibition of AMPK by RNAi knockdown or dominant negative (DN) mutation significantly inhibited belinostat-induced apoptosis in PANC-1 cells. Reversely, AMPK activator AICAR and A-769662 exerted strong cytotoxicity in PANC-1 cells. Belinostat promoted reactive oxygen species (ROS) production in PANC-1 cells, increased ROS induced transforming growth factor-β-activating kinase 1 (TAK1)/AMPK association to activate AMPK. Meanwhile, anti-oxidants N-Acetyl-Cysteine (NAC) and MnTBAP as well as TAK1 shRNA knockdown suppressed belinostat-induced AMPK activation and PANC-1 cell apoptosis. In conclusion, we propose that belinostat-induced apoptosis and growth inhibition require the activation of ROS-TAK1-AMPK signaling axis in cultured pancreatic cancer cells.

  9. Wnt1 inhibits hydrogen peroxide-induced apoptosis in mouse cardiac stem cells.

    Directory of Open Access Journals (Sweden)

    Jingjin Liu

    Full Text Available BACKGROUND: Because of their regenerative and paracrine abilities, cardiac stem cells (CSCs are the most appropriate, optimal and promising candidates for the development of cardiac regenerative medicine strategies. However, native and exogenous CSCs in ischemic hearts are exposed to various pro-apoptotic or cytotoxic factors preventing their regenerative and paracrine abilities. METHODS AND RESULTS: We examined the effects of H2O2 on mouse CSCs (mCSCs, and observed that hydrogen peroxide (H2O2 treatment induces mCSCs apoptosis via the caspase 3 pathway, in a dose-dependent manner. We then examined the effects of Wnt1 over-expression on H2O2-induced apoptosis in mCSCs and observed that Wnt1 significantly decreased H2O2-induced apoptosis in mCSCs. On the other hand, inhibition of the canonical Wnt pathway by the secreted frizzled related protein 2 (SFRP2 or knockdown of β-catenin in mCSCs reduced cells resistance to H2O2-induced apoptosis, suggesting that Wnt1 predominantly prevents H2O2-induced apoptosis through the canonical Wnt pathway. CONCLUSIONS: Our results provide the first evidences that Wnt1 plays an important role in CSCs' defenses against H2O2-induced apoptosis through the canonical Wnt1/GSK3β/β-catenin signaling pathway.

  10. Blueberry polyphenols prevent cardiomyocyte death by preventing calpain activation and oxidative stress.

    Science.gov (United States)

    Louis, Xavier Lieben; Thandapilly, Sijo Joseph; Kalt, Wilhelmina; Vinqvist-Tymchuk, Melinda; Aloud, Basma Milad; Raj, Pema; Yu, Liping; Le, Hoa; Netticadan, Thomas

    2014-08-01

    The purpose of this study was to examine the efficacy of an aqueous wild blueberry extract and five wild blueberry polyphenol fractions on an in vitro model of heart disease. Adult rat cardiomyocytes were pretreated with extract and fractions, and then exposed to norepinephrine (NE). Cardiomyocyte hypertrophy, cell death, oxidative stress, apoptosis and cardiomyocyte contractile function as well as the activities of calpain, superoxide dismutase (SOD) and catalase (CAT) were measured in cardiomyocytes treated with and without NE and blueberry fraction (BF). Four of five blueberry fractions prevented cell death and cardiomyocyte hypertrophy induced by NE. Total phenolic fraction was used for all further analysis. The NE-induced increase in oxidative stress, nuclear condensation, calpain activity and lowering of SOD and CAT activities were prevented upon pretreatment with BF. Reduced contractile function was also significantly improved with BF pretreatment. Blueberry polyphenols prevent NE-induced adult cardiomyocyte hypertrophy and cell death. The protective effects of BF may be in part attributed to a reduction in calpain activity and oxidative stress.

  11. Protein Phosphotyrosine Phosphatase 1B (PTP1B) in Calpain-dependent Feedback Regulation of Vascular Endothelial Growth Factor Receptor (VEGFR2) in Endothelial Cells

    Science.gov (United States)

    Zhang, Yixuan; Li, Qiang; Youn, Ji Youn; Cai, Hua

    2017-01-01

    The VEGF/VEGFR2/Akt/eNOS/NO pathway is essential to VEGF-induced angiogenesis. We have previously discovered a novel role of calpain in mediating VEGF-induced PI3K/AMPK/Akt/eNOS activation through Ezrin. Here, we sought to identify possible feedback regulation of VEGFR2 by calpain via its substrate protein phosphotyrosine phosphatase 1B (PTP1B), and the relevance of this pathway to VEGF-induced angiogenesis, especially in diabetic wound healing. Overexpression of PTP1B inhibited VEGF-induced VEGFR2 and Akt phosphorylation in bovine aortic endothelial cells, while PTP1B siRNA increased both, implicating negative regulation of VEGFR2 by PTP1B. Calpain inhibitor ALLN induced VEGFR2 activation, which can be completely blocked by PTP1B overexpression. Calpain activation induced by overexpression or Ca/A23187 resulted in PTP1B cleavage, which can be blocked by ALLN. Moreover, calpain activation inhibited VEGF-induced VEGFR2 phosphorylation, which can be restored by PTP1B siRNA. These data implicate calpain/PTP1B negative feedback regulation of VEGFR2, in addition to the primary signaling pathway of VEGF/VEGFR2/calpain/PI3K/AMPK/Akt/eNOS. We next examined a potential role of PTP1B in VEGF-induced angiogenesis. Endothelial cells transfected with PTP1B siRNA showed faster wound closure in response to VEGF. Aortic discs isolated from PTP1B siRNA-transfected mice also had augmented endothelial outgrowth. Importantly, PTP1B inhibition and/or calpain overexpression significantly accelerated wound healing in STZ-induced diabetic mice. In conclusion, our data for the first time demonstrate a calpain/PTP1B/VEGFR2 negative feedback loop in the regulation of VEGF-induced angiogenesis. Modulation of local PTP1B and/or calpain activities may prove beneficial in the treatment of impaired wound healing in diabetes. PMID:27872190

  12. Inhibition of c-Jun N-terminal kinase sensitizes tumor cells to flavonoid-induced apoptosis through down-regulation of JunD

    International Nuclear Information System (INIS)

    Kook, Sung-Ho; Son, Young-Ok; Jang, Yong-Suk; Lee, Kyung-Yeol; Lee, Seung-Ah; Kim, Beom-Soo; Lee, Hyun-Jeong; Lee, Jeong-Chae

    2008-01-01

    Reduction of susceptibility to apoptosis signals is a crucial step in carcinogenesis. Therefore, sensitization of tumor cells to apoptosis is a promising therapeutic strategy. c-Jun NH 2 -terminal kinase (JNK) has been implicated in stress-induced apoptosis. However, many studies also emphasize the role of JNK on cell survival, although its mechanisms are not completely understood. Previously, we found that inhibition of JNK activity promotes flavonoid-mediated apoptosis of human osteosarcoma cells. We thus determined whether inhibition of JNK sensitizes tumor cells to a bioflavonoid-induced apoptosis, and whether this effect of JNK is a general effect. As the results, quercetin and genistein as well as a flavonoid fraction induced apoptosis of tumor cells, which was further accelerated by specific JNK inhibitor, SP600125 or by small interfering RNA specific to JNK1/2. This effect was specific to types of cells because it was further apparent in tumorigenic cell lines. Inhibition of JNK by SP600125 also reduced flavonoid-stimulated nuclear induction of JunD which was known to have protective role in apoptosis, whereas JNK inhibition alone had little effect on apoptosis. The flavonoid-induced apoptosis of tumor cells was significantly enhanced by transfecting them with antisense JunD oligonucleotides. These results suggest that inhibition of JNK facilitates flavonoid-induced apoptosis through down-regulation of JunD, which is further sensitive to tumor cells. Therefore, combination with a specific JNK inhibitor further enhances the anti-cancer and chemopreventive potential of bio-flavonoids

  13. EVA1A inhibits GBM cell proliferation by inducing autophagy and apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Xue; Kan, Shifeng; Liu, Zhen [Department of Cell Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191 (China); Lu, Guang [Department of Cell Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191 (China); Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597 (Singapore); Zhang, Xiaoyan [Department of Cell Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191 (China); Chen, Yingyu [Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191 (China); Peking University Center for Human Disease Genomics, Beijing 100191 (China); Bai, Yun, E-mail: baiyun@bjmu.edu.cn [Department of Cell Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191 (China)

    2017-03-01

    Eva-1 homolog A (EVA1A) is a novel lysosome and endoplasmic reticulum-associated protein involved in autophagy and apoptosis. In this study, we constructed a recombinant adenovirus 5-EVA1A vector (Ad5-EVA1A) to overexpress EVA1A in glioblastoma (GBM) cell lines and evaluated its anti-tumor activities in vitro and in vivo. We found that overexpression of EVA1A in three GBM cell lines (U251, U87 and SHG44) resulted in a suppression of tumor cell growth via activation of autophagy and induction of cell apoptosis in a dose- and time-dependent manner. EVA1A-mediated autophagy was associated with inactivation of the mTOR/RPS6KB1 signaling pathway. Furthermore in vivo, overexpression of EVA1A successfully inhibited tumor growth in NOD/SCID mice. Our data suggest that EVA1A-induced autophagy and apoptosis play a role in suppressing the development of GBM and their up-regulation may be an effective method for treating this form of cancer. - Highlights: • Overexpression of EVA1A suppresses GBM cell growth. • EVA1A induces autophagy through the mTOR/RPS6KB1 pathway. • EVA1A induces GBM cell apoptosis. • EVA1A inhibits the development of GBM in vivo.

  14. BMPR2 inhibition induced apoptosis and autophagy via destabilization of XIAP in human chondrosarcoma cells

    Science.gov (United States)

    Jiao, G; Guo, W; Ren, T; Lu, Q; Sun, Y; Liang, W; Ren, C; Yang, K; Sun, K

    2014-01-01

    Bone morphogenetic proteins (BMPs) are multifunctional proteins, and their receptors (BMPRs) have crucial roles in the process of signaling. However, their function in cancer is somewhat inconsistent. It has been demonstrated that more prevalent expression of bone morphogenetic protein receptor 2 (BMPR2) has been detected in dedifferentiated chondrosarcomas than conventional chondrosarcomas. Here, we find that BMPR2 inhibition induces apoptosis and autophagy of chondrosarcoma. We found that BMPR2 expression was correlated with the clinicopathological features of chondrosarcomas, and could predict the treatment outcome. Knockdown of BMPR2 by small interfering RNA results in growth inhibition in chondrosarcoma cells. Silencing BMPR2 promoted G2/M cell cycle arrest, induced chondrosarcoma cell apoptosis through caspase-3-dependent pathway via repression of X-linked inhibitor of apoptosis protein (XIAP) and induced autophagy of chondrosarcoma cells via XIAP-Mdm2-p53 pathway. Inhibition of autophagy induced by BMPR2 small interfering RNA (siBMPR2) sensitized chondrosarcoma cells to siBMPR2-induced apoptotic cell death, suggesting that autophagy has a protective role for chondrosarcoma cells in context of siBMPR2-induced apoptotic cell death. In vivo tumorigenicity assay in mice indicated that inhibition of BMPR2 reduced tumor growth. Taken together, our results suggest that BMPR2 has a significant role in the tumorigenesis of chondrosarcoma, and could be an important prognostic marker for chondrosarcoma. BMPR2 inhibition could eventually provide a promising therapy for chondrosarcoma treatment. PMID:25501832

  15. A calpain-2 selective inhibitor enhances learning & memory by prolonging ERK activation.

    Science.gov (United States)

    Liu, Yan; Wang, Yubin; Zhu, Guoqi; Sun, Jiandong; Bi, Xiaoning; Baudry, Michel

    2016-06-01

    While calpain-1 activation is required for LTP induction by theta burst stimulation (TBS), calpain-2 activation limits its magnitude during the consolidation period. A selective calpain-2 inhibitor applied either before or shortly after TBS enhanced the degree of potentiation. In the present study, we tested whether the selective calpain-2 inhibitor, Z-Leu-Abu-CONH-CH2-C6H3 (3, 5-(OMe)2 (C2I), could enhance learning and memory in wild-type (WT) and calpain-1 knock-out (C1KO) mice. We first showed that C2I could reestablish TBS-LTP in hippocampal slices from C1KO mice, and this effect was blocked by PD98059, an inhibitor of ERK. TBS resulted in PTEN degradation in hippocampal slices from both WT and C1KO mice, and C2I treatment blocked this effect in both mouse genotypes. Systemic injection of C2I 30 min before training in the fear-conditioning paradigm resulted in a biphasic dose-response curve, with low doses enhancing and high doses inhibiting freezing behavior. The difference between the doses needed to enhance and inhibit learning matches the difference in concentrations producing inhibition of calpain-2 and calpain-1. A low dose of C2I also restored normal learning in a novel object recognition task in C1KO mice. Levels of SCOP, a ERK phosphatase known to be cleaved by calpain-1, were decreased in dorsal hippocampus early but not late following training in WT mice; C2I treatment did not affect the early decrease in SCOP levels but prevented its recovery at the later time-point and prolonged ERK activation. The results indicate that calpain-2 activation limits the extent of learning, an effect possibly due to temporal limitation of ERK activation, as a result of SCOP synthesis induced by calpain-2-mediated PTEN degradation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. GSK-3β Inhibition Attenuates CLP-Induced Liver Injury by Reducing Inflammation and Hepatic Cell Apoptosis

    Directory of Open Access Journals (Sweden)

    Hui Zhang

    2014-01-01

    Full Text Available Liver dysfunction has been known to occur frequently in cases of sepsis. Excessive inflammation and apoptosis are pathological features of acute liver failure. Recent studies suggest that activation of glycogen synthase kinase- (GSK- 3β is involved in inflammation and apoptosis. We aimed to investigate the protective effects of GSK-3β inhibition on polymicrobial sepsis-induced liver injury and to explore the possible mechanisms. Polymicrobial sepsis was induced by cecal ligation and puncture (CLP, and SB216763 was used to inhibit GSK-3β in C57BL/6 mice. GSK-3β was activated following CLP. Administration of SB216763 decreased mortality, ameliorated liver injury, and reduced hepatic apoptosis. The inhibition of GSK-3β also reduced leukocyte infiltration and hepatic inflammatory cytokine expression and release. Moreover, GSK-3β inhibition suppressed the transcriptional activity of nuclear factor-kappa B (NF-κB but enhanced the transcriptional activity of cAMP response element binding protein (CREB in the liver. In in vitro studies, GSK-3β inhibition reduced inflammatory cytokine production via modulation of NF-κB and CREB signaling pathways in lipopolysaccharide-stimulated macrophages. In conclusion, these findings suggest that GSK-3β blockade protects against CLP-induced liver via inhibition of inflammation by modulating NF-κB and CREB activity and suppression of hepatic apoptosis.

  17. Gemcitabine inhibits proliferation and induces apoptosis in human pancreatic cancer PANC-1 cells.

    Science.gov (United States)

    Yong-Xian, Gui; Xiao-Huan, Li; Fan, Zhang; Guo-Fang, Tian

    2016-10-01

    The aim of the study is to investigate the underlying molecular mechanisms by which gemcitabine (gem) inhibits proliferation and induces apoptosis in human pancreatic cancer PANC-1 cells in vitro. After PANC-1 cells had been treated by indicated concentration (0, 5, and 25 mg/L) of gem for 48 h, cell proliferation was evaluated by 3'-(4, 5 dimethyl-thiazol-2-yl)-2, 5-diphenyl tetrazolium bromide assay; cell morphology was observed by transmission electron microscopy; Expression of c-IAP2 and Bcl-2 proteins was analyzed by Western blot; the activity of caspase-3 and -9 was detected by spectrophotometry. Gem significantly inhibited cell proliferation and could induce apoptosis of human pancreatic cancer PANC-1 cells, with a dose-dependent manner. Western blot analysis showed that gem significantly reduced c-IAP2 and Bcl-2 proteins expression level (P PANC-1 cells. Gem could induce apoptosis of human pancreatic cancer PANC-1 cells, probably through downregulating c-IAP2 and Bcl-2 expression levels, and at the same time activating caspase-3 and -9.

  18. Thromboxane synthase suppression induces lung cancer cell apoptosis via inhibiting NF-κB

    International Nuclear Information System (INIS)

    Leung, Kin Chung; Li, Ming-Yue; Leung, Billy C.S.; Hsin, Michael K.Y.; Mok, Tony S.K.; Underwood, Malcolm J.; Chen, George G.

    2010-01-01

    Accumulating evidence shows that the inhibition of thromboxane synthase (TXS) induced apoptosis in cancer cells. TXS inhibitor 1-Benzylimidzole (1-BI) can trigger apoptosis in lung cancer cells but the mechanism is not fully defined. In this study, lung cancer cells were treated with 1-BI. In this study, the level of reactive oxygen species (ROS) was measured and NF-κB activity was determined in human lung cancer cells. The roles of ROS and NF-κB in 1-BI-mediated cell death were analyzed. The results showed that 1-BI induced ROS generation but decreased the activity of NF-κB by reducing phosphorylated IκBα (p-IκBα) and inhibiting the translocation of p65 into the nucleus. In contrast to 1-BI, antioxidant N-acetyl cysteine (NAC) stimulated cell proliferation and significantly protected the cells from 1-BI-mediated cell death by neutralizing ROS. Collectively, apoptosis induced by 1-BI is associated with the over-production of ROS and the reduction of NF-κB. Antioxidants can significantly block the inhibitory effect of 1-BI.

  19. A short caspase-3 isoform inhibits chemotherapy-induced apoptosis by blocking apoptosome assembly.

    Directory of Open Access Journals (Sweden)

    Frédérique Végran

    Full Text Available Alternative splicing of caspase-3 produces a short isoform caspase-3s that antagonizes caspase-3 apoptotic activity. However, the mechanism of apoptosis inhibition by caspase-3s remains unknown. Here we show that exogenous caspase-3 sensitizes MCF-7 and HBL100 breast cancers cells to chemotherapeutic treatments such as etoposide and methotrexate whereas co-transfection with caspase-3s strongly inhibits etoposide and methotrexate-induced apoptosis underlying thus the anti-apoptotic role of caspase-3s. In caspase-3 transfected cells, lamin-A and α-fodrin were cleaved when caspase-3 was activated by etoposide or methotrexate. When caspase-3s was co-transfected, this cleavage was strongly reduced. Depletion of caspase-3 by RNA interference in HBL100 containing endogenous caspase-3s caused reduction in etoposide and methotrexate-induced apoptosis, whereas the depletion of caspase-3s sensitized cells to chemotherapy. In the presence of caspase-3s, a lack of interaction between caspase-3 and caspase-9 was observed. Immunoprecipitation assays showed that caspase-3s binds the pro-forms of caspase-3. This result suggested that the absence of interaction with caspase-9 when both variants of caspase-3 are present contribute to block the apoptosome assembly and inhibit apoptosis. These data support that caspases-3s negatively interferes with caspase-3 activation and apoptosis in breast cancer, and that it can play key roles in the modulation of response to chemotherapeutic treatments.

  20. Autophagy and gap junctional intercellular communication inhibition are involved in cadmium-induced apoptosis in rat liver cells

    Energy Technology Data Exchange (ETDEWEB)

    Zou, Hui [College of Veterinary Medicine, Yangzhou University, and Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu, 225009 (China); Zhuo, Liling [College of Life Science, Zaozhuang University, Zaozhuang, Shandong, 277160 (China); Han, Tao; Hu, Di; Yang, Xiaokang; Wang, Yi; Yuan, Yan; Gu, Jianhong; Bian, Jianchun; Liu, Xuezhong [College of Veterinary Medicine, Yangzhou University, and Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu, 225009 (China); Liu, Zongping, E-mail: liuzongping@yzu.edu.cn [College of Veterinary Medicine, Yangzhou University, and Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu, 225009 (China)

    2015-04-17

    Cadmium (Cd) is known to induce hepatotoxicity, yet the underlying mechanism of how this occurs is not fully understood. In this study, Cd-induced apoptosis was demonstrated in rat liver cells (BRL 3A) with apoptotic nuclear morphological changes and a decrease in cell index (CI) in a time- and concentration-dependent manner. The role of gap junctional intercellular communication (GJIC) and autophagy in Cd-induced apoptosis was investigated. Cd significantly induced GJIC inhibition as well as downregulation of connexin 43 (Cx43). The prototypical gap junction blocker carbenoxolone disodium (CBX) exacerbated the Cd-induced decrease in CI. Cd treatment was also found to cause autophagy, with an increase in mRNA expression of autophagy-related genes Atg-5, Atg-7, Beclin-1, and microtubule-associated protein light chain 3 (LC3) conversion from cytosolic LC3-I to membrane-bound LC3-II. The autophagic inducer rapamycin (RAP) prevented the Cd-induced CI decrease, while the autophagic inhibitor chloroquine (CQ) caused a further reduction in CI. In addition, CBX promoted Cd-induced autophagy, as well as changes in expression of Atg-5, Atg-7, Beclin-1 and LC3. CQ was found to block the Cd-induced decrease in Cx43 and GJIC inhibition, whereas RAP had opposite effect. These results demonstrate that autophagy plays a protective role during Cd-induced apoptosis in BRL 3A cells during 6 h of experiment, while autophagy exacerbates Cd-induced GJIC inhibition which has a negative effect on cellular fate. - Highlights: • GJIC and autophagy is crucial for biological processes. • Cd exposure causes GJIC inhibition and autophagy increase in BRL 3A cells. • Autophagy protects Cd induced BRL 3A cells apoptosis at an early stage. • Autophagy exacerbates Cd-induced GJIC inhibition. • GJIC plays an important role in autophagy induced cell death or survival.

  1. A novel benzofuran derivative, ACDB, induces apoptosis of human chondrosarcoma cells through mitochondrial dysfunction and endoplasmic reticulum stress.

    Science.gov (United States)

    Su, Chen-Ming; Chen, Chien-Yu; Lu, Tingting; Sun, Yi; Li, Weimin; Huang, Yuan-Li; Tsai, Chun-Hao; Chang, Chih-Shiang; Tang, Chih-Hsin

    2016-12-13

    Chondrosarcoma is one of the bone tumor with high mortality in respond to poor radiation and chemotherapy treatment. Here, we analyze the antitumor activity of a novel benzofuran derivative, 2-amino-3-(2-chlorophenyl)-6-(4-dimethylaminophenyl)benzofuran-4-yl acetate (ACDB), in human chondrosarcoma cells. ACDB increased the cell apoptosis of human chondrosarcomas without harm in chondrocytes. ACDB also enhanced endoplasmic reticulum (ER) stress, which was characterized by varieties in the cytosolic calcium levels and induced the expression of glucose-regulated protein (GRP) and calpain. Furthermore, the ACDB-induced chondrosarcoma apoptosis was associated with the upregulation of the B cell lymphoma-2 (Bcl-2) family members including pro- and anti-apoptotic proteins, downregulation of dysfunctional mitochondria that released cytochrome C, and subsequent activation of caspases-3. In addition, the ACDB-mediated cellular apoptosis was suppressed by transfecting cells with glucose-regulated protein (GRP) and calpain siRNA or treating cells with ER stress chelators and caspase inhibitors. Interestingly, animal experiments illustrated a reduction in the tumor volume following ACDB treatment. Together, these results suggest that ACDB may be a novel tumor suppressor of chondrosarcoma, and this study demonstrates that the novel antitumor agent, ACDB, induced apoptosis by mitochondrial dysfunction and ER stress in human chondrosarcoma cells in vitro and in vivo.

  2. Calpain-mediated proteolysis of polycystin-1 C-terminus induces JAK2 and ERK signal alterations

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyunho [Transplantation Research Institute, Seoul National University Medical Research Center, Seoul (Korea, Republic of); Department of Medicine, University of Maryland, Baltimore, MD (United States); Kang, Ah-Young [Transplantation Research Institute, Seoul National University Medical Research Center, Seoul (Korea, Republic of); Department of Medicine, Program of Immunology, Graduate School, Seoul National University, Seoul (Korea, Republic of); Ko, Ah-ra [Clinical Research Center, Samsung Biomedical Research Institute, Seoul (Korea, Republic of); Park, Hayne Cho [Transplantation Research Institute, Seoul National University Medical Research Center, Seoul (Korea, Republic of); Research Coordination Center for Rare Diseases, Seoul National University Hospital, Seoul (Korea, Republic of); So, Insuk [Department of Physiology, Seoul National University College of Medicine, Seoul (Korea, Republic of); Park, Jong Hoon [Department of Biological Science, Sookmyung Women’s University, Seoul (Korea, Republic of); Cheong, Hae Il [Research Coordination Center for Rare Diseases, Seoul National University Hospital, Seoul (Korea, Republic of); Department of Pediatrics, Seoul National University Children’s Hospital, Seoul (Korea, Republic of); Kidney Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul (Korea, Republic of); Hwang, Young-Hwan [Research Coordination Center for Rare Diseases, Seoul National University Hospital, Seoul (Korea, Republic of); Department of Internal Medicine, Eulji General Hospital, Eulji University College of Medicine, Seoul (Korea, Republic of); and others

    2014-01-01

    Autosomal dominant polycystic kidney disease (ADPKD), a hereditary renal disease caused by mutations in PKD1 (85%) or PKD2 (15%), is characterized by the development of gradually enlarging multiple renal cysts and progressive renal failure. Polycystin-1 (PC1), PKD1 gene product, is an integral membrane glycoprotein which regulates a number of different biological processes including cell proliferation, apoptosis, cell polarity, and tubulogenesis. PC1 is a target of various proteolytic cleavages and proteosomal degradations, but its role in intracellular signaling pathways remains poorly understood. Herein, we demonstrated that PC1 is a novel substrate for μ- and m-calpains, which are calcium-dependent cysteine proteases. Overexpression of PC1 altered both Janus-activated kinase 2 (JAK2) and extracellular signal-regulated kinase (ERK) signals, which were independently regulated by calpain-mediated PC1 degradation. They suggest that the PC1 function on JAK2 and ERK signaling pathways might be regulated by calpains in response to the changes in intracellular calcium concentration. - Highlights: • Polycystin-1 is a target of ubiquitin-independent degradation by calpains. • The PEST domain is required for calpain-mediated degradation of polycystin-1. • Polycystin-1 may independently regulate JAK2 and ERK signaling pathways.

  3. Diclofenac inhibits tumor necrosis factor-α-induced nuclear factor-κB activation causing synergistic hepatocyte apoptosis.

    Science.gov (United States)

    Fredriksson, Lisa; Herpers, Bram; Benedetti, Giulia; Matadin, Quraisha; Puigvert, Jordi C; de Bont, Hans; Dragovic, Sanja; Vermeulen, Nico P E; Commandeur, Jan N M; Danen, Erik; de Graauw, Marjo; van de Water, Bob

    2011-06-01

    Drug-induced liver injury (DILI) is an important clinical problem. It involves crosstalk between drug toxicity and the immune system, but the exact mechanism at the cellular hepatocyte level is not well understood. Here we studied the mechanism of crosstalk in hepatocyte apoptosis caused by diclofenac and the proinflammatory cytokine tumor necrosis factor α (TNF-α). HepG2 cells were treated with diclofenac followed by TNF-α challenge and subsequent evaluation of necrosis and apoptosis. Diclofenac caused a mild apoptosis of HepG2 cells, which was strongly potentiated by TNF-α. A focused apoptosis machinery short interference RNA (siRNA) library screen identified that this TNF-α-mediated enhancement involved activation of caspase-3 through a caspase-8/Bid/APAF1 pathway. Diclofenac itself induced sustained activation of c-Jun N-terminal kinase (JNK) and inhibition of JNK decreased both diclofenac and diclofenac/TNF-α-induced apoptosis. Live cell imaging of GFPp65/RelA showed that diclofenac dampened the TNF-α-mediated nuclear factor kappaB (NF-κB) translocation oscillation in association with reduced NF-κB transcriptional activity. This was associated with inhibition by diclofenac of the TNF-α-induced phosphorylation of the inhibitor of NF-κB alpha (IκBα). Finally, inhibition of IκB kinase β (IKKβ) with BMS-345541 as well as stable lentiviral short hairpin RNA (shRNA)-based knockdown of p65/RelA sensitized hepatocytes towards diclofenac/TNF-α-induced cytotoxicity. Together, our data suggest a model whereby diclofenac-mediated stress signaling suppresses TNF-α-induced survival signaling routes and sensitizes cells to apoptosis. Copyright © 2011 American Association for the Study of Liver Diseases.

  4. N-acetylcysteine protects against cadmium-induced germ cell apoptosis by inhibiting endoplasmic reticulum stress in testes.

    Science.gov (United States)

    Ji, Yan-Li; Wang, Hua; Zhang, Cheng; Zhang, Ying; Zhao, Mei; Chen, Yuan-Hua; Xu, De-Xiang

    2013-03-01

    Cadmium (Cd) is a reproductive toxicant that induces germ cell apoptosis in the testes. Previous studies have demonstrated that endoplasmic reticulum (ER) stress is involved in Cd-induced germ cell apoptosis. The aim of the present study was to investigate the effects of N-acetylcysteine (NAC), an antioxidant, on Cd-induced ER stress and germ cell apoptosis in the testes. Male CD-1 mice were intraperitoneally injected with CdCl2 (2.0 mg kg(-1)). As expected, acute Cd exposure induced germ cell apoptosis in the testes, as determined by terminal dUTP nick-end labelling (TUNEL). However, the administration of NAC alleviated Cd-induced germ cell apoptosis in the testes. Further analysis showed that NAC attenuated the Cd-induced upregulation of testicular glucose-regulated protein 78 (GRP78), an important ER molecular chaperone. Moreover, NAC inhibited the Cd-induced phosphorylation of testicular eukaryotic translation initiation factor 2α (eIF2α), a downstream target of the double-stranded RNA-activated kinase-like ER kinase (PERK) pathway. In addition, NAC blocked the Cd-induced activation of testicular X binding protein (XBP)-1, indicating that NAC attenuates the Cd-induced ER stress and the unfolded protein response (UPR). Interestingly, NAC almost completely prevented the Cd-induced elevation of C/EBP homologous protein (CHOP) and phosphorylation of c-Jun N-terminal kinase (JNK), two components of the ER stress-mediated apoptotic pathway. In conclusion, NAC protects against Cd-induced germ cell apoptosis by inhibiting endoplasmic reticulum stress in the testes.

  5. Effect of dicycloplatin, a novel platinum chemotherapeutical drug, on inhibiting cell growth and inducing cell apoptosis.

    Directory of Open Access Journals (Sweden)

    Guang-quan Li

    Full Text Available Dicycloplatin, a new supramolecular platinum-based antitumor drug, has been approved by the State Food and Administration (SFDA of China. In this study, we investigated the anticancer activity of dicycloplatin in cancer cells and signaling pathways involved in dicycloplatin-induced apoptosis. Dicycloplatin inhibited the proliferation of cancer cells and increased the percentage of apoptosis in a concentration-dependent manner. Besides, some apoptosis related events were observed after treatment with dicycloplatin, including increase of reactive oxygen species (ROS, collapse of mitochondrial membrane potential (Δψm, release of cytochrome c from the mitochondria to the cytosol, upregulation of p53, which were accompanied by activation of caspase-9, caspase-3, caspase-8, and poly (ADP-ribose polymerase cleavage in a concentration-dependent manner. The role of apoptosis in dicycloplatin-mediated cell death was further confirmed by the concomitant treatment with caspase-8 or caspase-9 inhibitors, which inhibited apoptosis and PARP cleavage. Intracellular glutathione (GSH was also found to inhibit the cytotoxic effect of dicycloplatin. In conclusion, these findings suggest that dicycloplatin induces apoptosis through ROS stress-mediated death receptor pathway and mitochondrial pathway which is similar to carboplatin.

  6. Resveratrol protects vascular endothelial cells from high glucose-induced apoptosis through inhibition of NADPH oxidase activation-driven oxidative stress.

    Science.gov (United States)

    Chen, Feng; Qian, Li-Hua; Deng, Bo; Liu, Zhi-Min; Zhao, Ying; Le, Ying-Ying

    2013-09-01

    Hyperglycemia-induced oxidative stress has been implicated in diabetic vascular complications in which NADPH oxidase is a major source of reactive oxygen species (ROS) generation. Resveratrol is a naturally occurring polyphenol, which has vasoprotective effects in diabetic animal models and inhibits high glucose (HG)-induced oxidative stress in endothelial cells. We aimed to examine whether HG-induced NADPH oxidase activation and ROS production contribute to glucotoxicity to endothelial cells and the effect of resveratrol on glucotoxicity. Using a murine brain microvascular endothelial cell line bEnd3, we found that NADPH oxidase inhibitor (apocynin) and resveratrol both inhibited HG-induced endothelial cell apoptosis. HG-induced elevation of NADPH oxidase activity and production of ROS were inhibited by apocynin, suggesting that HG induces endothelial cell apoptosis through NADPH oxidase-mediated ROS production. Mechanistic studies revealed that HG upregulated NADPH oxidase subunit Nox1 but not Nox2, Nox4, and p22(phox) expression through NF-κB activation, which resulted in elevation of NADPH oxidase activity and consequent ROS production. Resveratrol prevented HG-induced endothelial cell apoptosis through inhibiting HG-induced NF-κB activation, NADPH oxidase activity elevation, and ROS production. HG induces endothelial cell apoptosis through NF-κB/NADPH oxidase/ROS pathway, which was inhibited by resveratrol. Our findings provide new potential therapeutic targets against brain vascular complications of diabetes. © 2013 John Wiley & Sons Ltd.

  7. Inhibition of TRAIL-induced apoptosis and forced internalization of TRAIL receptor 1 by adenovirus proteins.

    Science.gov (United States)

    Tollefson, A E; Toth, K; Doronin, K; Kuppuswamy, M; Doronina, O A; Lichtenstein, D L; Hermiston, T W; Smith, C A; Wold, W S

    2001-10-01

    Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) induces apoptosis through two receptors, TRAIL-R1 (also known as death receptor 4) and TRAIL-R2 (also known as death receptor 5), that are members of the TNF receptor superfamily of death domain-containing receptors. We show that human adenovirus type 5 encodes three proteins, named RID (previously named E3-10.4K/14.5K), E3-14.7K, and E1B-19K, that independently inhibit TRAIL-induced apoptosis of infected human cells. This conclusion was derived from studies using wild-type adenovirus, adenovirus replication-competent mutants that lack one or more of the RID, E3-14.7K, and E1B-19K genes, and adenovirus E1-minus replication-defective vectors that express all E3 genes, RID plus E3-14.7K only, RID only, or E3-14.7K only. RID inhibits TRAIL-induced apoptosis when cells are sensitized to TRAIL either by adenovirus infection or treatment with cycloheximide. RID induces the internalization of TRAIL-R1 from the cell surface, as shown by flow cytometry and indirect immunofluorescence for TRAIL-R1. TRAIL-R1 was internalized in distinct vesicles which are very likely to be endosomes and lysosomes. TRAIL-R1 is degraded, as indicated by the disappearance of the TRAIL-R1 immunofluorescence signal. Degradation was inhibited by bafilomycin A1, a drug that prevents acidification of vesicles and the sorting of receptors from late endosomes to lysosomes, implying that degradation occurs in lysosomes. RID was also shown previously to internalize and degrade another death domain receptor, Fas, and to prevent apoptosis through Fas and the TNF receptor. RID was shown previously to force the internalization and degradation of the epidermal growth factor receptor. E1B-19K was shown previously to block apoptosis through Fas, and both E1B-19K and E3-14.7K were found to prevent apoptosis through the TNF receptor. These findings suggest that the receptors for TRAIL, Fas ligand, and TNF play a role in limiting virus

  8. High glucose-induced Ca2+ overload and oxidative stress contribute to apoptosis of cardiac cells through mitochondrial dependent and independent pathways.

    Science.gov (United States)

    Kumar, Sandeep; Kain, Vasundhara; Sitasawad, Sandhya L

    2012-07-01

    Cardiac cell apoptosis is the initiating factor of cardiac complications especially diabetic cardiomyopathy. Mitochondria are susceptible to the damaging effects of elevated glucose condition. Calcium overload and oxidative insult are the two mutually non-exclusive phenomena suggested to cause cardiac dysfunction. Here, we examined the effect of high-glucose induced calcium overload in calpain-1 mediated cardiac apoptosis in an in vitro setting. H9c2, rat ventricular myoblast cell line was treated with elevated glucose condition and the cellular consequences were studied. Intracellular calcium trafficking, ROS generation, calpain-1 activation and caspase-12 and caspase-9 pathway were studied using flow cytometry, confocal microscopy and Western blot analysis. High-glucose treatment resulted in increased intracellular calcium ([Ca2+]i) which was mobilized to the mitochondria. Concomitant intra-mitochondrial calcium ([Ca2+]m) increase resulted in enhanced reactive oxygen and nitrogen species generation. These events led to mitochondrial dysfunction and apoptosis. Cardiomyocyte death exhibited several classical markers of apoptosis, including activation of caspases, appearance of annexin V on the outer plasma membrane, increased population of cells with sub-G0/G1 DNA content and nuclear condensation. Key findings include elucidation of cell signaling mechanism of high-glucose induced calcium-dependent cysteine protease calpain-1 activation, which triggers non-conventional caspases as alternate mode of cell death. This information increases the understanding of cardiac cell death under hyperglycemic condition and can possibly be extended for designing new therapeutic strategies for diabetic cardiomyopathy. The novel findings of the study reveal that high glucose induces apoptosis by both mitochondria-dependent and independent pathways via concomitant rise in intracellular calcium. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. STAT6 silencing induces hepatocellular carcinoma-derived cell apoptosis and growth inhibition by decreasing the RANKL expression.

    Science.gov (United States)

    Qing, Tian; Yamin, Zhang; Guijie, Wang; Yan, Jin; Zhongyang, Shen

    2017-08-01

    Signal transducer and activator of transcription-6 (STAT6) is highly expressed in various human cancers and considered a regulator of multiple biological processes in cancers, including cell apoptosis. Evidence has indicated that STAT6 predicts a worse prognosis in hepatocellular carcinoma (HCC) patients. The objective of this study was to investigate the effects and mechanism of STAT6 in human HCC cells. We found that STAT6 silencing significantly inhibited HepG2 and Hep3B cell survival and proliferation. We observed that depletion of STAT6 increased HepG2 and Hep3B cell apoptosis by using a histone DNA ELISA detection kit. STAT6 silencing induced expression of apoptosis-associated genes Bax and caspase-3/7 and inhibited anti-apoptosis gene Bcl-2 levels. We also observed that STAT6 silencing downregulated the expression of receptor activator of NF-κB ligand (RANKL). Our results demonstrated that treatment with pcDNA3.1-RANKL abolished STAT6 depletion-induced HepG2 and Hep3B cell apoptosis and growth inhibition. Based on these findings, we believe that RANKL plays a major role in STAT6-induced HCC cell apoptosis. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  10. Tang-Luo-Ning, a Traditional Chinese Medicine, Inhibits Endoplasmic Reticulum Stress-Induced Apoptosis of Schwann Cells under High Glucose Environment

    Directory of Open Access Journals (Sweden)

    Weijie Yao

    2017-01-01

    Full Text Available Tang-Luo-Ning (TLN has a definite effect in the clinical treatment of diabetic peripheral neuropathy (DPN. Schwann cells (SCs apoptosis induced by endoplasmic reticulum stress (ER stress is one of the main pathogeneses of DPN. This study investigates whether TLN can inhibit SCs apoptosis by inhibiting ER stress-induced apoptosis. Our previous researches have demonstrated that TLN could increase the expression of ER stress marker protein GRP78 and inhibited the expression of apoptosis marker protein CHOP in ER stress. In this study, the results showed that TLN attenuated apoptosis by decreasing Ca2+ level in SCs and maintaining ER morphology. TLN could decrease downstream proteins of CHOP including GADD34 and Ero1α, while it increased P-eIF2α and decreased the upstream proteins of CHOP including P-IRE1α/IRE1α and XBP-1, thereby reducing ER stress-induced apoptosis.

  11. Nec-1 Enhances Shikonin-Induced Apoptosis in Leukemia Cells by Inhibition of RIP-1 and ERK1/2

    Directory of Open Access Journals (Sweden)

    Hongming Pan

    2012-06-01

    Full Text Available Necrostatin-1 (Nec-1 inhibits necroptosis by allosterically inhibiting the kinase activity of receptor-interacting protein 1 (RIP1, which plays a critical role in necroptosis. RIP1 is a crucial adaptor kinase involved in the activation of NF-κB, production of reactive oxygen species (ROS and the phosphorylation of mitogen activated protein kinases (MAPKs. NF-κB, ROS and MAPKs all play important roles in apoptotic signaling. Nec-1 was regarded as having no effect on apoptosis. Here, we report that Nec-1 increased the rate of nuclear condensation and caspases activation induced by a low concentration of shikonin (SHK in HL60, K562 and primary leukemia cells. siRNA-mediated knockdown of RIP1 significantly enhanced shikonin-induced apoptosis in K562 and HL60 cells. Shikonin treatment alone could slightly inhibit the phosphorylation of ERK1/2 in leukemia cells, and the inhibitory effect on ERK1/2 was significantly augmented by Nec-1. We also found that Nec-1 could inhibit NF-κB p65 translocation to the nucleus at a later stage of SHK treatment. In conclusion, we found that Nec-1 can promote shikonin-induced apoptosis in leukemia cells. The mechanism by which Nec-1 sensitizes shikonin-induced apoptosis appears to be the inhibition of RIP1 kinase-dependent phosphorylation of ERK1/2. To our knowledge, this is the first study to document Nec-1 sensitizes cancer cells to apoptosis.

  12. Lycium barbarum Polysaccharides Protect Rat Corneal Epithelial Cells against Ultraviolet B-Induced Apoptosis by Attenuating the Mitochondrial Pathway and Inhibiting JNK Phosphorylation

    Directory of Open Access Journals (Sweden)

    Shaobo Du

    2017-01-01

    Full Text Available Lycium barbarum polysaccharides (LBPs have been shown to play a key role in protecting the eyes by reducing the apoptosis induced by certain types of damage. However, it is not known whether LBPs can protect damaged corneal cells from apoptosis. Moreover, no reports have focused on the role of LBPs in guarding against ultraviolet B- (UVB- induced apoptosis. The present study aimed to investigate the protective effect and underlying mechanism of LBPs against UVB-induced apoptosis in rat corneal epithelial (RCE cells. The results showed that LBPs significantly prevented the loss of cell viability and inhibited cell apoptosis induced by UVB in RCE cells. LBPs also inhibited UVB-induced loss of mitochondrial membrane potential, downregulation of Bcl-2, and upregulation of Bax and caspase-3. Finally, LBPs attenuated the phosphorylation of c-Jun NH2-terminal kinase (JNK triggered by UVB. In summary, LBPs protect RCE cells against UVB-induced damage and apoptosis, and the underlying mechanism involves the attenuation of the mitochondrial apoptosis pathway and the inhibition of JNK phosphorylation.

  13. Biguanides sensitize leukemia cells to ABT-737-induced apoptosis by inhibiting mitochondrial electron transport

    Science.gov (United States)

    Velez, Juliana; Pan, Rongqing; Lee, Jason T.C.; Enciso, Leonardo; Suarez, Marta; Duque, Jorge Eduardo; Jaramillo, Daniel; Lopez, Catalina; Morales, Ludis; Bornmann, William; Konopleva, Marina; Krystal, Gerald; Andreeff, Michael; Samudio, Ismael

    2016-01-01

    Metformin displays antileukemic effects partly due to activation of AMPK and subsequent inhibition of mTOR signaling. Nevertheless, Metformin also inhibits mitochondrial electron transport at complex I in an AMPK-independent manner, Here we report that Metformin and rotenone inhibit mitochondrial electron transport and increase triglyceride levels in leukemia cell lines, suggesting impairment of fatty acid oxidation (FAO). We also report that, like other FAO inhibitors, both agents and the related biguanide, Phenformin, increase sensitivity to apoptosis induction by the bcl-2 inhibitor ABT-737 supporting the notion that electron transport antagonizes activation of the intrinsic apoptosis pathway in leukemia cells. Both biguanides and rotenone induce superoxide generation in leukemia cells, indicating that oxidative damage may sensitize toABT-737 induced apoptosis. In addition, we demonstrate that Metformin sensitizes leukemia cells to the oligomerization of Bak, suggesting that the observed synergy with ABT-737 is mediated, at least in part, by enhanced outer mitochondrial membrane permeabilization. Notably, Phenformin was at least 10-fold more potent than Metformin in abrogating electron transport and increasing sensitivity to ABT-737, suggesting that this agent may be better suited for targeting hematological malignancies. Taken together, our results suggest that inhibition of mitochondrial metabolism by Metformin or Phenformin is associated with increased leukemia cell susceptibility to induction of intrinsic apoptosis, and provide a rationale for clinical studies exploring the efficacy of combining biguanides with the orally bioavailable derivative of ABT-737, Venetoclax. PMID:27283492

  14. Evaluation of the neuronal apoptotic pathways involved in cytoskeletal disruption-induced apoptosis.

    Science.gov (United States)

    Jordà, Elvira G; Verdaguer, Ester; Jimenez, Andrés; Arriba, S Garcia de; Allgaier, Clemens; Pallàs, Mercè; Camins, Antoni

    2005-08-01

    The cytoskeleton is critical to neuronal functioning and survival. Cytoskeletal alterations are involved in several neurodegenerative diseases such as Alzheimer's and Parkinson's diseases. We studied the possible pathways involved in colchicine-induced apoptosis in cerebellar granule neurons (CGNs). Although colchicine evoked an increase in caspase-3, caspase-6 and caspase-9 activation, selective caspase inhibitors did not attenuate apoptosis. Inhibitors of other cysteine proteases such as PD150606 (a calpain-specific inhibitor), Z-Phe-Ala fluoromethyl ketone (a cathepsins-inhibitors) and N(alpha)-p-tosyl-l-lysine chloromethyl ketone (serine-proteases inhibitor) also had no effect on cell death/apoptosis induced by colchicine. However, BAPTA-AM 10 microM (intracellular calcium chelator) prevented apoptosis mediated by cytoskeletal alteration. These data indicate that calcium modulates colchicine-induced apoptosis in CGNs. PARP-1 inhibitors did not prevent apoptosis mediated by colchicine. Finally, colchicine-induced apoptosis in CGNs was attenuated by kenpaullone, a cdk5 inhibitor. Kenpaullone and indirubin also prevented cdk5/p25 activation mediated by colchicine. These findings indicate that cytoskeletal alteration can compromise cdk5 activation, regulating p25 formation and suggest that cdk5 inhibitors attenuate apoptosis mediated by cytoskeletal alteration. The present data indicate the potential therapeutic value of drugs that prevent the formation of p25 for the treatment of neurodegenerative disorders.

  15. Interleukin-24 induces neuroblastoma SH-SY5Y cell differentiation, growth inhibition, and apoptosis by promoting ROS production.

    Science.gov (United States)

    Li, Yuan; Zhang, Hongwei; Zhu, Xiaoyu; Feng, Dongchuan; Gong, Jinchao; Han, Tao

    2013-11-01

    Neuroblastoma is among the most aggressive tumors that occur in childhood and infancy. The clinical prognosis of children with advanced-stage neuroblastoma is still poor. Interleukin-24 (IL-24) is emerging as a new cytokine involved in tumor cellular proliferation, differentiation, and apoptosis and has been widely studied as a tumor inhibitor. However, little is known about this cytokine's role in neuroblastoma. In this study, we investigated the possible effects of IL-24 on inducing neuroblastoma cell differentiation, growth inhibition, and apoptosis in vitro. Our data show that IL-24 promotes neuroblastoma SH-SY5Y cell differentiation, growth inhibition, and apoptosis. Furthermore, we found that the differentiation- and apoptosis-inducing action of IL-24 depends on the accumulation of reactive oxygen species (ROS). These results suggest that IL-24 can induce neuroblastoma cell differentiation and apoptosis and may be a potential therapeutic agent for neuroblastoma.

  16. Regulation of apoptosis-inducing factor-mediated, cisplatin-induced apoptosis by Akt

    OpenAIRE

    Yang, X; Fraser, M; Abedini, M R; Bai, T; Tsang, B K

    2008-01-01

    Cisplatin is a first-line chemotherapeutic for ovarian cancer, although chemoresistance limits treatment success. Apoptosis, an important determinant of cisplatin sensitivity, occurs via caspase-dependent and -independent mechanisms. Activation of the protein kinase Akt, commonly observed in ovarian tumours, confers resistance to ovarian cancer cells via inhibition of caspase-dependent apoptosis. However, the effect of Akt on cisplatin-induced, caspase-independent apoptosis remains unclear. W...

  17. Signal transduction of p53-independent apoptotic pathway induced by hexavalent chromium in U937 cells

    International Nuclear Information System (INIS)

    Hayashi, Yoko; Kondo, Takashi; Zhao Qingli; Ogawa Ryohei; Cui Zhengguo; Feril, Loreto B.; Teranishi, Hidetoyo; Kasuya, Minoru

    2004-01-01

    It has been reported that the hexavalent chromium compound (Cr(VI)) can induce both p53-dependent and p53-independent apoptosis. While a considerable amount of information is available on the p53-dependent pathway, only little is known about the p53-independent pathway. To elucidate the p53-independent mechanism, the roles of the Ca 2+ -calpain- and mitochondria-caspase-dependent pathways in apoptosis induced by Cr(VI) were investigated. When human lymphoma U937 cells, p53 mutated cells, were treated with 20 μM Cr(VI) for 24 h, nuclear morphological changes and DNA fragmentation were observed. Production of hydroxyl radicals revealed by electron paramagnetic resonance (EPR)-spin trapping, and increase of intracellular calcium ion concentration monitored by digital imaging were also observed in Cr(VI)-treated cells. An intracellular Ca 2+ chelator, BAPTA-AM, and calpain inhibitors suppressed the Cr(VI)-induced DNA fragmentation. The number of cells showing low mitochondrial membrane potential (MMP), high level of superoxide anion radicals (O 2 - ), and high activity of caspase-3, which are indicators of mitochondria-caspase-dependent pathway, increased significantly in Cr(VI)-treated cells. An antioxidant, N-acetyl-L-cysteine (NAC), decreased DNA fragmentation and inhibited the changes in MMP, O 2 - formation, and activation of caspase-3 induced by Cr(VI). No increase of the expressions of Fas and phosphorylated JNK was observed after Cr(VI) treatment. Cell cycle analysis revealed that the fraction of G2/M phase tended to increase after 24 h of treatment, suggesting that Cr(VI)-induced apoptosis is related to the G2 block. These results indicate that Ca 2+ -calpain- and mitochondria-caspase-dependent pathways play significant roles in the Cr(VI)-induced apoptosis via the G2 block, which are independent of JNK and Fas activation. The inhibition of apoptosis and all its signal transductions by NAC suggests that intracellular reactive oxygen species (ROS) are

  18. Raddeanin A induces human gastric cancer cells apoptosis and inhibits their invasion in vitro

    International Nuclear Information System (INIS)

    Xue, Gang; Zou, Xi; Zhou, Jin-Yong; Sun, Wei; Wu, Jian; Xu, Jia-Li; Wang, Rui-Ping

    2013-01-01

    Highlights: •Raddeanin A is a triterpenoid saponin in herb medicine Anemone raddeana Regel. •Raddeanin A can inhibit 3 kinds of gastric cancer cells’ proliferation and invasion. •Caspase-cascades’ activation indicates apoptosis induced by Raddeanin A. •MMPs, RECK, Rhoc and E-cad are involved in Raddeanin A-induced invasion inhibition. -- Abstract: Raddeanin A is one of the triterpenoid saponins in herbal medicine Anemone raddeana Regel which was reported to suppress the growth of liver and lung cancer cells. However, little was known about its effect on gastric cancer (GC) cells. This study aimed to investigate its inhibitory effect on three kinds of different differentiation stage GC cells (BGC-823, SGC-7901 and MKN-28) in vitro and the possible mechanisms. Proliferation assay and flow cytometry demonstrated Raddeanin A’s dose-dependent inhibitory effect and determined its induction of cells apoptosis, respectively. Transwell assay, wounding heal assay and cell matrix adhesion assay showed that Raddeanin A significantly inhibited the abilities of the invasion, migration and adhesion of the BGC-823 cells. Moreover, quantitative real time PCR and Western blot analysis found that Raddeanin A increased Bax expression while reduced Bcl-2, Bcl-xL and Survivin expressions and significantly activated caspase-3, caspase-8, caspase-9 and poly-ADP ribose polymerase (PARP). Besides, Raddeanin A could also up-regulate the expression of reversion inducing cysteine rich protein with Kazal motifs (RECK), E-cadherin (E-cad) and down-regulate the expression of matrix metalloproteinases-2 (MMP-2), MMP-9, MMP-14 and Rhoc. In conclusion, Raddeanin A inhibits proliferation of human GC cells, induces their apoptosis and inhibits the abilities of invasion, migration and adhesion, exhibiting potential to become antitumor drug

  19. Raddeanin A induces human gastric cancer cells apoptosis and inhibits their invasion in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Gang [Department of Oncology, Nanjing University of Chinese Medicine, Nanjing (China); Zou, Xi [Department of Oncology, Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of Traditional Chinese Medicine, Nanjing (China); Zhou, Jin-Yong [Laboratory Center, Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of Traditional Chinese Medicine, Nanjing (China); Sun, Wei [Department of Oncology, Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of Traditional Chinese Medicine, Nanjing (China); Wu, Jian [Laboratory Center, Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of Traditional Chinese Medicine, Nanjing (China); Xu, Jia-Li [Department of Oncology, Nanjing University of Chinese Medicine, Nanjing (China); Wang, Rui-Ping, E-mail: ruipingwang61@hotmail.com [Department of Oncology, Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of Traditional Chinese Medicine, Nanjing (China)

    2013-09-20

    Highlights: •Raddeanin A is a triterpenoid saponin in herb medicine Anemone raddeana Regel. •Raddeanin A can inhibit 3 kinds of gastric cancer cells’ proliferation and invasion. •Caspase-cascades’ activation indicates apoptosis induced by Raddeanin A. •MMPs, RECK, Rhoc and E-cad are involved in Raddeanin A-induced invasion inhibition. -- Abstract: Raddeanin A is one of the triterpenoid saponins in herbal medicine Anemone raddeana Regel which was reported to suppress the growth of liver and lung cancer cells. However, little was known about its effect on gastric cancer (GC) cells. This study aimed to investigate its inhibitory effect on three kinds of different differentiation stage GC cells (BGC-823, SGC-7901 and MKN-28) in vitro and the possible mechanisms. Proliferation assay and flow cytometry demonstrated Raddeanin A’s dose-dependent inhibitory effect and determined its induction of cells apoptosis, respectively. Transwell assay, wounding heal assay and cell matrix adhesion assay showed that Raddeanin A significantly inhibited the abilities of the invasion, migration and adhesion of the BGC-823 cells. Moreover, quantitative real time PCR and Western blot analysis found that Raddeanin A increased Bax expression while reduced Bcl-2, Bcl-xL and Survivin expressions and significantly activated caspase-3, caspase-8, caspase-9 and poly-ADP ribose polymerase (PARP). Besides, Raddeanin A could also up-regulate the expression of reversion inducing cysteine rich protein with Kazal motifs (RECK), E-cadherin (E-cad) and down-regulate the expression of matrix metalloproteinases-2 (MMP-2), MMP-9, MMP-14 and Rhoc. In conclusion, Raddeanin A inhibits proliferation of human GC cells, induces their apoptosis and inhibits the abilities of invasion, migration and adhesion, exhibiting potential to become antitumor drug.

  20. A novel mouse PKC{delta} splice variant, PKC{delta}IX, inhibits etoposide-induced apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung D. [School of Biological Sciences, University of Ulsan, Ulsan (Korea, Republic of); Seo, Kwang W. [Department of Internal Medicines, Ulsan University Hospital and School of Medicine, University of Ulsan, Ulsan (Korea, Republic of); Lee, Eun A.; Quang, Nguyen N. [School of Biological Sciences, University of Ulsan, Ulsan (Korea, Republic of); Cho, Hong R. [Department of Surgery, Ulsan University Hospital and School of Medicine, University of Ulsan, Ulsan (Korea, Republic of); Biomedical Research Center, Ulsan University Hospital and School of Medicine, University of Ulsan, Ulsan (Korea, Republic of); Kwon, Byungsuk, E-mail: bskwon@mail.ulsan.as.kr [School of Biological Sciences, University of Ulsan, Ulsan (Korea, Republic of); Biomedical Research Center, Ulsan University Hospital and School of Medicine, University of Ulsan, Ulsan (Korea, Republic of)

    2011-07-01

    Highlights: {yields} A novel PKC{delta} isoform, named PKC{delta}IX, that lacks the C1 domain and the ATP-binding site is ubiquitously expressed. {yields} PKC{delta}IX inhibits etoposide-induced apoptosis. {yields} PKC{delta}IX may function as an endogenous dominant negative isoform for PKC{delta}. -- Abstract: Protein kinase C (PKC) {delta} plays an important role in cellular proliferation and apoptosis. The catalytic fragment of PKC{delta} generated by caspase-dependent cleavage is essential for the initiation of etoposide-induced apoptosis. In this study, we identified a novel mouse PKC{delta} isoform named PKC{delta}IX (Genebank Accession No. (HQ840432)). PKC{delta}IX is generated by alternative splicing and is ubiquitously expressed, as seen in its full-length PKC{delta}. PKC{delta}IX lacks the C1 domain, the caspase 3 cleavage site, and the ATP binding site but preserves an almost intact c-terminal catalytic domain and a nuclear localization signal (NLS). The structural characteristics of PKC{delta}IX provided a possibility that this PKC{delta} isozyme functions as a novel dominant-negative form for PKC{delta} due to its lack of the ATP-binding domain that is required for the kinase activity of PKC{delta}. Indeed, overexpression of PKC{delta}IX significantly inhibited etoposide-induced apoptosis in NIH3T3 cells. In addition, an in vitro kinase assay showed that recombinant PKC{delta}IX protein could competitively inhibit the kinase activity of PKC{delta}. We conclude that PKC{delta}IX can function as a natural dominant-negative inhibitor of PKC{delta}in vivo.

  1. Inhibition of X-ray and doxorubicin-induced apoptosis by butyrolactone I, a CDK-specific inhibitor, in human tumor cells

    International Nuclear Information System (INIS)

    Lu Yanjun; Takebe, Hiraku; Yagi, Takashi

    2000-01-01

    Cell-cycle progression is coordinately regulated by cyclin-dependent kinases (CDKs). The inhibition of CDKs by p21 wafl/Cipl/Sdil prevents the apoptosis of cells treated with DNA-damaging agents. In this study, we found that butyrolactone I, a specific inhibitor of CDC2 family kinases, blocks the X-ray- or doxorubicin-induced apoptosis of DLD1 (p21 +/+) human colorectal carcinoma cells in a dose-dependent manner. We also found that butyrolactone I inhibits the CDK2 activity and enhances cell survival after an X-ray irradiation or doxorubicin treatment in both DLD1 (p21 -/-) and DLD1 (p21 +/+) cells. These findings suggest that butyrolactone I prevents apoptosis by the direct inhibition of CDK and also, possibly, by CDK-inhibition through p53-independent p21-induction. Our findings indicate that CDK activity is required for DNA-damaging agent-induced apoptosis. (author)

  2. Identification of active Plasmodium falciparum calpain to establish screening system for Pf-calpain-based drug development

    Directory of Open Access Journals (Sweden)

    Soh Byoung

    2013-02-01

    Full Text Available Abstract Background With the increasing resistance of malaria parasites to available drugs, there is an urgent demand to develop new anti-malarial drugs. Calpain inhibitor, ALLN, is proposed to inhibit parasite proliferation by suppressing haemoglobin degradation. This provides Plasmodium calpain as a potential target for drug development. Pf-calpain, a cysteine protease of Plasmodium falciparum, belongs to calpain-7 family, which is an atypical calpain not harboring Ca2+-binding regulatory motifs. In this present study, in order to establish the screening system for Pf-calpain specific inhibitors, the active form of Pf-calpain was first identified. Methods Recombinant Pf-calpain including catalytic subdomain IIa (rPfcal-IIa was heterologously expressed and purified. Enzymatic activity was determined by both fluorogenic substrate assay and gelatin zymography. Molecular homology modeling was carried out to address the activation mode of Pf-calpain in the aspect of structural moiety. Results Based on the measurement of enzymatic activity and protease inhibitor assay, it was found that the active form of Pf-calpain only contains the catalytic subdomain IIa, suggesting that Pf-calpain may function as a monomeric form. The sequence prediction indicates that the catalytic subdomain IIa contains all amino acid residues necessary for catalytic triad (Cys-His-Asn formation. Molecular modeling suggests that the Pf-calpain subdomain IIa makes an active site, holding the catalytic triad residues in their appropriate orientation for catalysis. The mutation analysis further supports that those amino acid residues are functional and have enzymatic activity. Conclusion The identified active form of Pf-calpain could be utilized to establish high-throughput screening system for Pf-calpain inhibitors. Due to its unique monomeric structural property, Pf-calpain could be served as a novel anti-malarial drug target, which has a high specificity for malaria parasite

  3. The alpha2-adrenoreceptor agonist dexmedetomidine protects against lipopolysaccharide-induced apoptosis via inhibition of gap junctions in lung fibroblasts.

    Science.gov (United States)

    Zhang, Yuan; Tan, Xiaoming; Xue, Lianfang

    2018-01-01

    The α2-adrenoceptor inducer dexmedetomidine protects against acute lung injury (ALI), but the mechanism of this effect is largely unknown. The present study investigated the effect of dexmedetomidine on apoptosis induced by lipopolysaccharide (LPS) and the relationship between this effect and gap junction intercellular communication in human lung fibroblast cell line. Flow cytometry was used to detect apoptosis induced by LPS. Parachute dye coupling assay was used to measure gap junction function, and western blot analysis was used to determine the expression levels of connexin43 (Cx43). The results revealed that exposure of human lung fibroblast cell line to LPS for 24 h increased the apoptosis, and pretreatment of dexmedetomidine and 18α-GA significantly reduced LPS-induced apoptosis. Dexmedetomidine exposure for 1 h inhibited gap junction function mainly via a decrease in Cx43 protein levels in human lung fibroblast cell line. These results demonstrated that the inhibition of gap junction intercellular communication by dexmedetomidine affected the LPS-induced apoptosis through inhibition of gap junction function by reducing Cx43 protein levels. The present study provides evidence of a novel mechanism underlying the effects of analgesics in counteracting ALI. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Ubiquitin-dependent system controls radiation induced apoptosis

    International Nuclear Information System (INIS)

    Delic, J.; Magdelenat, H.; Glaisner, S.; Magdelenat, H.; Maciorowski, Z.

    1997-01-01

    The selective proteolytic pathway, dependent upon 'N-end rule' protein recognition/ubiquitination and on the subsequent proteasome dependent processing of ubiquitin conjugates, operates in apoptosis induced by γ-irradiation. The proteasome inhibitor peptide aldehyde, MG132, efficiently induced apoptosis and was also able (at doses lower than those required for apoptosis induction) to potentiate apoptosis induced by DNA damage. Its specificity is suggested by the induction of the ubiquitin (UbB and UbC) and E1 (ubiquitin activating enzyme) genes and by an altered ubiquitination pattern. More selectively, a di-peptide competitor of the 'N-end rule' of ubiquitin dependent protein processing inhibited radiation induced apoptosis. This inhibition is also followed by an altered ubiquitination pattern and by activation of Poly (ADP-ribose) polymerase (PARP). These data strongly suggest that early apoptosis radiation induced events are controlled by ubiquitin-dependent proteolytic processing. (author)

  5. Disulfide bond within mu-calpain active site inhibits activity and autolysis.

    Science.gov (United States)

    Lametsch, René; Lonergan, Steven; Huff-Lonergan, Elisabeth

    2008-09-01

    Oxidative processes have the ability to influence mu-calpain activity. In the present study the influence of oxidation on activity and autolysis of mu-calpain was examined. Furthermore, LC-MS/MS analysis was employed to identify and characterize protein modifications caused by oxidation. The results revealed that the activity of mu-calpain is diminished by oxidation with H2O2 in a reversible manner involving cysteine and that the rate of autolysis of mu-calpain concomitantly slowed. The LC-MS/MS analysis of the oxidized mu-calpain revealed that the amino acid residues 105-133 contained a disulfide bond between Cys(108) and Cys(115). The finding that the active site cysteine in mu-calpain is able to form a disulfide bond has, to our knowledge, not been reported before. This could be part of a unique oxidation mechanism for mu-calpain. The results also showed that the formation of the disulfide bond is limited in the control (no oxidant added), and further limited in a concentration-dependent manner when beta-mercaptoethanol is added. However, the disulfide bond is still present to some extent in all conditions indicating that the active site cysteine is potentially highly susceptible to the formation of this intramolecular disulfide bond.

  6. Cytoprotection by fructose and other ketohexoses during bile salt-induced apoptosis of hepatocytes.

    Science.gov (United States)

    Zeid, I M; Bronk, S F; Fesmier, P J; Gores, G J

    1997-01-01

    Toxic bile salts cause hepatocyte necrosis at high concentrations and apoptosis at lower concentrations. Although fructose prevents bile salt-induced necrosis, the effect of fructose on bile salt-induced apoptosis is unclear. Our aim was to determine if fructose also protects against bile salt-induced apoptosis. Fructose inhibited glycochenodeoxycholate (GCDC)-induced apoptosis in a concentration-dependent manner with a maximum inhibition of 72% +/- 10% at 10 mmol/L. First, we determined if fructose inhibited apoptosis by decreasing adenosine triphosphate (ATP) and intracellular pH (pHi). Although fructose decreased ATP to effects, alterations in the expression of bcl-2, or metal chelation, we next determined if the poorly metabolized ketohexoses, tagatose and sorbose, also inhibited apoptosis; unexpectedly, both ketohexoses inhibited apoptosis. Because bile salt-induced apoptosis and necrosis are inhibited by fructose, these data suggest that similar processes initiate bile salt-induced hepatocyte necrosis and apoptosis. In contrast, acidosis, which inhibits necrosis, potentiates apoptosis. Thus, ketohexose-sensitive pathways appear to initiate both bile salt-induced cell apoptosis and necrosis, whereas dissimilar, pH-sensitive, effector mechanisms execute these two different cell death processes.

  7. Inhibition of PKR protects against H2O2-induced injury on neonatal cardiac myocytes by attenuating apoptosis and inflammation.

    Science.gov (United States)

    Wang, Yongyi; Men, Min; Xie, Bo; Shan, Jianggui; Wang, Chengxi; Liu, Jidong; Zheng, Hui; Yang, Wengang; Xue, Song; Guo, Changfa

    2016-12-08

    Reactive oxygenation species (ROS) generated from reperfusion results in cardiac injury through apoptosis and inflammation, while PKR has the ability to promote apoptosis and inflammation. The aim of the study was to investigate whether PKR is involved in hydrogen peroxide (H 2 O 2 ) induced neonatal cardiac myocytes (NCM) injury. In our study, NCM, when exposed to H 2 O 2 , resulted in persistent activation of PKR due to NCM endogenous RNA. Inhibition of PKR by 2-aminopurine (2-AP) or siRNA protected against H 2 O 2 induced apoptosis and injury. To elucidate the mechanism, we revealed that inhibition of PKR alleviated H 2 O 2 induced apoptosis companied by decreased caspase3/7 activity, BAX and caspase-3 expression. We also revealed that inhibition of PKR suppressed H 2 O 2 induced NFκB pathway and NLRP3 activation. Finally, we found ADAR1 mRNA and protein expression were both induced after H 2 O 2 treatment through STAT-2 dependent pathway. By gain and loss of ADAR1 expression, we confirmed ADAR1 modulated PKR activity. Therefore, we concluded inhibition of PKR protected against H 2 O 2 -induced injury by attenuating apoptosis and inflammation. A self-preservation mechanism existed in NCM that ADAR1 expression is induced by H 2 O 2 to limit PKR activation simultaneously. These findings identify a novel role for PKR/ADAR1 in myocardial reperfusion injury.

  8. Altered Ca2+ homeostasis induces Calpain-Cathepsin axis activation in sporadic Creutzfeldt-Jakob disease.

    Science.gov (United States)

    Llorens, Franc; Thüne, Katrin; Sikorska, Beata; Schmitz, Matthias; Tahir, Waqas; Fernández-Borges, Natalia; Cramm, Maria; Gotzmann, Nadine; Carmona, Margarita; Streichenberger, Nathalie; Michel, Uwe; Zafar, Saima; Schuetz, Anna-Lena; Rajput, Ashish; Andréoletti, Olivier; Bonn, Stefan; Fischer, Andre; Liberski, Pawel P; Torres, Juan Maria; Ferrer, Isidre; Zerr, Inga

    2017-04-27

    Sporadic Creutzfeldt-Jakob disease (sCJD) is the most prevalent form of human prion disease and it is characterized by the presence of neuronal loss, spongiform degeneration, chronic inflammation and the accumulation of misfolded and pathogenic prion protein (PrP Sc ). The molecular mechanisms underlying these alterations are largely unknown, but the presence of intracellular neuronal calcium (Ca 2+ ) overload, a general feature in models of prion diseases, is suggested to play a key role in prion pathogenesis.Here we describe the presence of massive regulation of Ca 2+ responsive genes in sCJD brain tissue, accompanied by two Ca 2+ -dependent processes: endoplasmic reticulum stress and the activation of the cysteine proteases Calpains 1/2. Pathogenic Calpain proteins activation in sCJD is linked to the cleavage of their cellular substrates, impaired autophagy and lysosomal damage, which is partially reversed by Calpain inhibition in a cellular prion model. Additionally, Calpain 1 treatment enhances seeding activity of PrP Sc in a prion conversion assay. Neuronal lysosomal impairment caused by Calpain over activation leads to the release of the lysosomal protease Cathepsin S that in sCJD mainly localises in axons, although massive Cathepsin S overexpression is detected in microglial cells. Alterations in Ca 2+ homeostasis and activation of Calpain-Cathepsin axis already occur at pre-clinical stages of the disease as detected in a humanized sCJD mouse model.Altogether our work indicates that unbalanced Calpain-Cathepsin activation is a relevant contributor to the pathogenesis of sCJD at multiple molecular levels and a potential target for therapeutic intervention.

  9. Ripk3 induces mitochondrial apoptosis via inhibition of FUNDC1 mitophagy in cardiac IR injury

    Directory of Open Access Journals (Sweden)

    Hao Zhou

    2017-10-01

    Full Text Available Ripk3-required necroptosis and mitochondria-mediated apoptosis are the predominant types of cell death that largely account for the development of cardiac ischemia reperfusion injury (IRI. Here, we explored the effect of Ripk3 on mitochondrial apoptosis. Compared with wild-type mice, the infarcted area in Ripk3-deficient (Ripk3-/- mice had a relatively low abundance of apoptotic cells. Moreover, the loss of Ripk3 protected the mitochondria against IRI and inhibited caspase9 apoptotic pathways. These protective effects of Ripk3 deficiency were relied on mitophagy activation. However, inhibition of mitophagy under Ripk3 deficiency enhanced cardiomyocyte and endothelia apoptosis, augmented infarcted area and induced microvascular dysfunction. Furthermore, ischemia activated mitophagy by modifying FUNDC1 dephosphorylation, which substantively engulfed mitochondria debris and cytochrome-c, thus blocking apoptosis signal. However, reperfusion injury elevated the expression of Ripk3 which disrupted FUNDC1 activation and abated mitophagy, increasing the likelihood of apoptosis. In summary, this study confirms the promotive effect of Ripk3 on mitochondria-mediated apoptosis via inhibition of FUNDC1-dependent mitophagy in cardiac IRI. These findings provide new insight into the roles of Ripk3-related necroptosis, mitochondria-mediated apoptosis and FUNDC1-required mitophagy in cardiac IRI.

  10. KAEMPFEROL, A FLAVONOID COMPOUND FROM GYNURA MEDICA INDUCED APOPTOSIS AND GROWTH INHIBITION IN MCF-7 BREAST CANCER CELL.

    Science.gov (United States)

    Yi, Xiaofang; Zuo, Jiangcheng; Tan, Chao; Xian, Sheng; Luo, Chunhua; Chen, Sai; Yu, Liangfang; Luo, Yucheng

    2016-01-01

    Kaempferol, a natural flavonoid, has been shown to induce cancer cell apoptosis and cell growth inhibition in several tumors. Previously we have conducted a full investigation on the chemical constituents of Gynura medica , kaempferol and its glycosides are the major constituents of G. medica . Here we investigated the growth inhibition and apoptosis induction effect of kaempferol extracted from G. medica . The inhibition effects of kaempferol were evaluated by MTS assay and soft agar colony formation assay. Fluorescence staining and western blotting were be used to study the apoptosis. The structure was identified by 1 H- NMR), 13 C-NMR and ESI-MS analyses. Our results showed that kaempferol's inhibition of MCF-7 breast cancer cell growth may through inducing apoptosis and downregulation of Bcl2 expression. Kaempferol is a promising cancer preventive and therapeutic agent for breast cancer. List of non-standard abbreviations: MTS: 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, HPLC: High-performance liquid chromatography, NMR: Nuclear Magnetic Resonance, ESI-MS Electrospray Ionization Mass Spectral, PARP: Poly ADP-ribose polymerase.

  11. SOX6 and PDCD4 enhance cardiomyocyte apoptosis through LPS-induced miR-499 inhibition.

    Science.gov (United States)

    Jia, Zhuqing; Wang, Jiaji; Shi, Qiong; Liu, Siyu; Wang, Weiping; Tian, Yuyao; Lu, Qin; Chen, Ping; Ma, Kangtao; Zhou, Chunyan

    2016-02-01

    Sepsis-induced cardiac apoptosis is one of the major pathogenic factors in myocardial dysfunction. As it enhances numerous proinflammatory factors, lipopolysaccharide (LPS) is considered the principal mediator in this pathological process. However, the detailed mechanisms involved are unclear. In this study, we attempted to explore the mechanisms involved in LPS-induced cardiomyocyte apoptosis. We found that LPS stimulation inhibited microRNA (miR)-499 expression and thereby upregulated the expression of SOX6 and PDCD4 in neonatal rat cardiomyocytes. We demonstrate that SOX6 and PDCD4 are target genes of miR-499, and they enhance LPS-induced cardiomyocyte apoptosis by activating the BCL-2 family pathway. The apoptosis process enhanced by overexpression of SOX6 or PDCD4, was rescued by the cardiac-abundant miR-499. Overexpression of miR-499 protected the cardiomyocytes against LPS-induced apoptosis. In brief, our results demonstrate the existence of a miR-499-SOX6/PDCD4-BCL-2 family pathway in cardiomyocytes in response to LPS stimulation.

  12. CR108, a novel vitamin K3 derivative induces apoptosis and breast tumor inhibition by reactive oxygen species and mitochondrial dysfunction

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Chun-Ru [Department of Biological Science and Technology, National Chiao Tung University, Hsinchu 30068, Taiwan (China); Liao, Wei-Siang [Institute of Molecular Medicine and Bioengineering, National Chiao Tung University, Hsinchu 30068, Taiwan (China); Wu, Ya-Hui [Department of Biological Science and Technology, National Chiao Tung University, Hsinchu 30068, Taiwan (China); Murugan, Kaliyappan [Department of Chemistry, National Dong Hwa University, Hualien 974, Taiwan (China); Chen, Chinpiao, E-mail: chinpiao@mail.ndhu.edu.tw [Department of Chemistry, National Dong Hwa University, Hualien 974, Taiwan (China); Chao, Jui-I, E-mail: jichao@faculty.nctu.edu.tw [Department of Biological Science and Technology, National Chiao Tung University, Hsinchu 30068, Taiwan (China); Institute of Molecular Medicine and Bioengineering, National Chiao Tung University, Hsinchu 30068, Taiwan (China)

    2013-12-15

    Vitamin K3 derivatives have been shown to exert anticancer activities. Here we show a novel vitamin K3 derivative (S)-2-(2-hydroxy-3-methylbutylthio)naphthalene-1,4-dione, which is named as CR108 that induces apoptosis and tumor inhibition through reactive oxygen species (ROS) and mitochondrial dysfunction in human breast cancer. CR108 is more effective on the breast cancer cell death than other vitamin K3 derivatives. Moreover, CR108 induced apoptosis in both the non-HER-2-overexpressed MCF-7 and HER-2-overexpressed BT-474 breast cancer cells. CR108 caused the loss of mitochondrial membrane potential, cytochrome c released from mitochondria to cytosol, and cleaved PARP proteins for apoptosis induction. CR108 markedly increased ROS levels in breast cancer cells. N-acetylcysteine (NAC), a general ROS scavenger, completely blocked the CR108-induced ROS levels, mitochondrial dysfunction and apoptosis. Interestingly, CR108 increased the phosphorylation of p38 MAP kinase but conversely inhibited the survivin protein expression. NAC treatment prevented the activation of p38 MAP kinase and rescued the survivin protein levels. SB202190, a specific p38 MAP kinase inhibitor, recovered the survivin protein levels and attenuated the cytotoxicity of CR108-treated cells. Furthermore, CR108 inhibited the xenografted human breast tumor growth in nude mice. Together, we demonstrate that CR108 is a novel vitamin K3 derivative that induces apoptosis and tumor inhibition by ROS production and mitochondrial dysfunction and associates with the phosphorylation of p38 MAP kinase and the inhibition of survivin in the human breast cancer. - Highlights: • CR108 is more effective on the cell death than other vitamin K3 derivatives. • CR108 induces apoptosis and tumor inhibition by ROS and mitochondrial dysfunction. • CR108 induces apoptosis by p38 kinase activation and survivin inhibition. • CR108 is a potent vitamin K3 analog that can develop for breast cancer therapy.

  13. CR108, a novel vitamin K3 derivative induces apoptosis and breast tumor inhibition by reactive oxygen species and mitochondrial dysfunction

    International Nuclear Information System (INIS)

    Yang, Chun-Ru; Liao, Wei-Siang; Wu, Ya-Hui; Murugan, Kaliyappan; Chen, Chinpiao; Chao, Jui-I

    2013-01-01

    Vitamin K3 derivatives have been shown to exert anticancer activities. Here we show a novel vitamin K3 derivative (S)-2-(2-hydroxy-3-methylbutylthio)naphthalene-1,4-dione, which is named as CR108 that induces apoptosis and tumor inhibition through reactive oxygen species (ROS) and mitochondrial dysfunction in human breast cancer. CR108 is more effective on the breast cancer cell death than other vitamin K3 derivatives. Moreover, CR108 induced apoptosis in both the non-HER-2-overexpressed MCF-7 and HER-2-overexpressed BT-474 breast cancer cells. CR108 caused the loss of mitochondrial membrane potential, cytochrome c released from mitochondria to cytosol, and cleaved PARP proteins for apoptosis induction. CR108 markedly increased ROS levels in breast cancer cells. N-acetylcysteine (NAC), a general ROS scavenger, completely blocked the CR108-induced ROS levels, mitochondrial dysfunction and apoptosis. Interestingly, CR108 increased the phosphorylation of p38 MAP kinase but conversely inhibited the survivin protein expression. NAC treatment prevented the activation of p38 MAP kinase and rescued the survivin protein levels. SB202190, a specific p38 MAP kinase inhibitor, recovered the survivin protein levels and attenuated the cytotoxicity of CR108-treated cells. Furthermore, CR108 inhibited the xenografted human breast tumor growth in nude mice. Together, we demonstrate that CR108 is a novel vitamin K3 derivative that induces apoptosis and tumor inhibition by ROS production and mitochondrial dysfunction and associates with the phosphorylation of p38 MAP kinase and the inhibition of survivin in the human breast cancer. - Highlights: • CR108 is more effective on the cell death than other vitamin K3 derivatives. • CR108 induces apoptosis and tumor inhibition by ROS and mitochondrial dysfunction. • CR108 induces apoptosis by p38 kinase activation and survivin inhibition. • CR108 is a potent vitamin K3 analog that can develop for breast cancer therapy

  14. Calpain inhibition reduces amplitude and accelerates decay of the late sodium current in ventricular myocytes from dogs with chronic heart failure.

    Directory of Open Access Journals (Sweden)

    Albertas Undrovinas

    Full Text Available Calpain is an intracellular Ca²⁺-activated protease that is involved in numerous Ca²⁺ dependent regulation of protein function in many cell types. This paper tests a hypothesis that calpains are involved in Ca²⁺-dependent increase of the late sodium current (INaL in failing heart. Chronic heart failure (HF was induced in 2 dogs by multiple coronary artery embolization. Using a conventional patch-clamp technique, the whole-cell INaL was recorded in enzymatically isolated ventricular cardiomyocytes (VCMs in which INaL was activated by the presence of a higher (1 μM intracellular [Ca²⁺] in the patch pipette. Cell suspensions were exposed to a cell- permeant calpain inhibitor MDL-28170 for 1-2 h before INaL recordings. The numerical excitation-contraction coupling (ECC model was used to evaluate electrophysiological effects of calpain inhibition in silico. MDL caused acceleration of INaL decay evaluated by the two-exponential fit (τ₁ = 42±3.0 ms τ₂ = 435±27 ms, n = 6, in MDL vs. τ₁ = 52±2.1 ms τ₂ = 605±26 control no vehicle, n = 11, and vs. τ₁ = 52±2.8 ms τ₂ = 583±37 ms n = 7, control with vehicle, P<0.05 ANOVA. MDL significantly reduced INaL density recorded at -30 mV (0.488±0.03, n = 12, in control no vehicle, 0.4502±0.0210, n = 9 in vehicle vs. 0.166±0.05pA/pF, n = 5, in MDL. Our measurements of current-voltage relationships demonstrated that the INaL density was decreased by MDL in a wide range of potentials, including that for the action potential plateau. At the same time the membrane potential dependency of the steady-state activation and inactivation remained unchanged in the MDL-treated VCMs. Our ECC model predicted that calpain inhibition greatly improves myocyte function by reducing the action potential duration and intracellular diastolic Ca²⁺ accumulation in the pulse train.Calpain inhibition reverses INaL changes in failing dog ventricular

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

    Science.gov (United States)

    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. © 2015 International Federation for Cell Biology.

  16. Ku70 inhibits gemcitabine-induced DNA damage and pancreatic cancer cell apoptosis

    International Nuclear Information System (INIS)

    Ma, Jiali; Hui, Pingping; Meng, Wenying; Wang, Na; Xiang, Shihao

    2017-01-01

    The current study focused on the role of Ku70, a DNA-dependent protein kinase (DNA-PK) complex protein, in pancreatic cancer cell resistance to gemcitabine. In both established cell lines (Mia-PaCa-2 and PANC-1) and primary human pancreatic cancer cells, shRNA/siRNA-mediated knockdown of Ku70 significantly sensitized gemcitabine-induced cell death and proliferation inhibition. Meanwhile, gemcitabine-induced DNA damage and subsequent pancreatic cancer cell apoptosis were also potentiated with Ku70 knockdown. On the other hand, exogenous overexpression of Ku70 in Mia-PaCa-2 cells suppressed gemcitabine-induced DNA damage and subsequent cell apoptosis. In a severe combined immune deficient (SCID) mice Mia-PaCa-2 xenograft model, gemcitabine-induced anti-tumor activity was remarkably pontificated when combined with Ku70 shRNA knockdown in the xenografts. The results of this preclinical study imply that Ku70 might be a primary resistance factor of gemcitabine, and Ku70 silence could significantly chemo-sensitize gemcitabine in pancreatic cancer cells. - Highlights: • Ku70 knockdown sensitizes gemcitabine-induced killing of pancreatic cancer cells. • Ku70 knockdown facilitates gemcitabine-induced DNA damage and cell apoptosis. • Ku70 overexpression deceases gemcitabine's sensitivity in pancreatic cancer cells. • Ku70 knockdown sensitizes gemcitabine-induced anti-tumor activity in vivo.

  17. Regorafenib Induces Apoptosis and Inhibits Metastatic Potential of Human Bladder Carcinoma Cells.

    Science.gov (United States)

    Hsu, Fei-Ting; Sun, Cho-Chin; Wu, Chia-Hsing; Lee, Yen-Ju; Chiang, Chih-Hung; Wang, Wei-Shu

    2017-09-01

    The aim of the present study was to verify the effects of regorafenib on apoptosis and metastatic potential in TSGH 8301 human bladder carcinoma cells in vitro. Cells were treated with different concentration of regorafenib for different periods of time. Effects of regorafenib on cell viability, apoptosis pathways, metastatic potential, and expression of metastatic and anti-apoptotic proteins were evaluated with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) assay, flow cytometry, cell migration and invasion assay, and western blotting. We found regorafenib significantly reduced cell viability, cell migration and invasion, and expression of metastatic and anti-apoptotic proteins. In addition, regorafenib significantly induced accumulation of sub-G 1 phase cells, loss of mitochondrial membrane potential, and expression of active caspase-3 and caspase-8. These results show that regorafenib not only induces apoptosis, but also inhibits metastatic potential in bladder cancer TSGH 8301 cells in vitro. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  18. Role of calpain-10 in the development of diabetes mellitus and its complications.

    Science.gov (United States)

    Pánico, Pablo; Salazar, Ana María; Burns, Anna L; Ostrosky-Wegman, Patricia

    2014-02-01

    Calpain activity has been implicated in several cellular processes such as cell signaling, apoptosis, exocytosis, mitochondrial metabolism and cytoskeletal remodeling. Evidence has indicated that the impairment of calpain expression and the activity of different calpain family members are involved in diverse pathologies. Calpain-10 has been implicated in the development of type 2 diabetes, and polymorphisms in the CAPN10 gene have been associated with an increased risk of developing this disease. The present work focused on the molecular biology of calpain-10, supporting its key participation in glucose metabolism. Current knowledge regarding the role of calpain-10 in the development of type 2 diabetes mellitus and diabetes-related diseases is additionally reviewed. Copyright © 2014 IMSS. Published by Elsevier Inc. All rights reserved.

  19. Protein Phosphotyrosine Phosphatase 1B (PTP1B) in Calpain-dependent Feedback Regulation of Vascular Endothelial Growth Factor Receptor (VEGFR2) in Endothelial Cells: IMPLICATIONS IN VEGF-DEPENDENT ANGIOGENESIS AND DIABETIC WOUND HEALING.

    Science.gov (United States)

    Zhang, Yixuan; Li, Qiang; Youn, Ji Youn; Cai, Hua

    2017-01-13

    The VEGF/VEGFR2/Akt/eNOS/NO pathway is essential to VEGF-induced angiogenesis. We have previously discovered a novel role of calpain in mediating VEGF-induced PI3K/AMPK/Akt/eNOS activation through Ezrin. Here, we sought to identify possible feedback regulation of VEGFR2 by calpain via its substrate protein phosphotyrosine phosphatase 1B (PTP1B), and the relevance of this pathway to VEGF-induced angiogenesis, especially in diabetic wound healing. Overexpression of PTP1B inhibited VEGF-induced VEGFR2 and Akt phosphorylation in bovine aortic endothelial cells, while PTP1B siRNA increased both, implicating negative regulation of VEGFR2 by PTP1B. Calpain inhibitor ALLN induced VEGFR2 activation, which can be completely blocked by PTP1B overexpression. Calpain activation induced by overexpression or Ca/A23187 resulted in PTP1B cleavage, which can be blocked by ALLN. Moreover, calpain activation inhibited VEGF-induced VEGFR2 phosphorylation, which can be restored by PTP1B siRNA. These data implicate calpain/PTP1B negative feedback regulation of VEGFR2, in addition to the primary signaling pathway of VEGF/VEGFR2/calpain/PI3K/AMPK/Akt/eNOS. We next examined a potential role of PTP1B in VEGF-induced angiogenesis. Endothelial cells transfected with PTP1B siRNA showed faster wound closure in response to VEGF. Aortic discs isolated from PTP1B siRNA-transfected mice also had augmented endothelial outgrowth. Importantly, PTP1B inhibition and/or calpain overexpression significantly accelerated wound healing in STZ-induced diabetic mice. In conclusion, our data for the first time demonstrate a calpain/PTP1B/VEGFR2 negative feedback loop in the regulation of VEGF-induced angiogenesis. Modulation of local PTP1B and/or calpain activities may prove beneficial in the treatment of impaired wound healing in diabetes. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  20. Hypoxia-induced autophagy is inhibited by PADI4 knockdown, which promotes apoptosis of fibroblast-like synoviocytes in rheumatoid arthritis

    Science.gov (United States)

    Fan, Tingting; Zhang, Changsong; Zong, Ming; Fan, Lieying

    2018-01-01

    Impaired apoptosis of rheumatoid arthritis (RA)-fibroblast-like synoviocytes (FLS) is pivotal in the process of RA. Peptidyl arginine deiminase type IV (PADI4) is associated with autoantibody regulation via histone citrullination in RA. The present study aimed to investigate the role of PADI4 in the apoptosis of RA-FLS. FLS were isolated from patients with RA and a rat model. The effects of PADI4 on RA-FLS were investigated in vitro and in vivo. Hypoxia-induced autophagy was induced by 1% O2 and was detected by immunohistochemical and immunofluorescence analysis; in addition, apoptosis was detected by flow cytometry. RA-FLS obtained from RA rat model exhibited significant proliferation under severe hypoxia conditions. Hypoxia also significantly induced autophagy and elevated the expression of PADI4. Subsequently, short hairpin RNA-mediated PADI4 knockdown was demonstrated to significantly inhibit hypoxia-induced autophagy and promote apoptosis in RA-FLS. The results of these in vitro and in vivo studies suggested that PADI4 may be closely associated with hypoxia-induced autophagy, and the inhibition of hypoxia-induced autophagy by PADI4 knockdown may contribute to an increase in the apoptosis of RA-FLS. PMID:29393388

  1. Downregulation of β1,4-galactosyltransferase 1 inhibits CDK11p58-mediated apoptosis induced by cycloheximide

    International Nuclear Information System (INIS)

    Li Zejuan; Wang Hanzhou; Zong Hongliang; Sun Qing; Kong Xiangfei; Jiang Jianhai; Gu Jianxin

    2005-01-01

    Cyclin-dependent kinase 11 (CDK11; also named PITSLRE) is part of the large family of p34 cdc2 -related kinases whose functions appear to be linked with cell cycle progression, tumorigenesis, and apoptotic signaling. The mechanism that CDK11 p58 induces apoptosis is not clear. Some evidences suggested β1,4-galactosyltransferase 1 (β1,4-GT 1) might participate in apoptosis induced by CDK11 p58 . In this study, we demonstrated that ectopically expressed β1,4-GT 1 increased CDK11 p58 -mediated apoptosis induced by cycloheximide (CHX). In contrast, RNAi-mediated knockdown of β1,4-GT 1 effectively inhibited apoptosis induced by CHX in CDK11 p58 -overexpressing cells. For example, the cell morphological and nuclear changes were reduced; the loss of cell viability was prevented and the number of cells in sub-G1 phase was decreased. Knock down of β1,4-GT 1 also inhibited the release of cytochrome c from mitochondria and caspase-3 processing. Therefore, the cleavage of CDK11 p58 by caspase-3 was reduced. We proposed that β1,4-GT 1 might contribute to the pro-apoptotic effect of CDK11 p58 . This may represent a new mechanism of β1,4-GT 1 in CHX-induced apoptosis of CDK11 p58 -overexpressing cells

  2. Glycogen synthase kinase-3 inhibition sensitizes human induced pluripotent stem cells to thiol-containing antioxidants induced apoptosis.

    Science.gov (United States)

    Tu, Chengyi; Xu, Robert; Koleti, Meghana; Zoldan, Janet

    2017-08-01

    Inhibition of glycogen synthase kinase 3 (GSK3) is an extensively used strategy to activate Wnt pathway for pluripotent stem cell (PSC) differentiation. However, the effects of such inhibition on PSCs, besides upregulating the Wnt pathway, have rarely been investigated despite that GSK3 is broadly involved in other cellular activities such as insulin signaling and cell growth/survival regulation. Here we describe a previously unknown synergistic effect between GSK3 inhibition (e.g., Chir99021 and LY2090314) and various normally non-toxic thiol-containing antioxidants (e.g., N-acetylcysteine, NAC) on the induction of apoptosis in human induced pluripotent stem cells (iPSCs). Neither Chir99021 nor the antioxidants individually induced significant apoptosis, whereas their combined treatment resulted in rapid and extensive apoptosis, with substantial caspase 3 activity observed within 3h and over 90% decrease in cell viability after 24h. We confirmed the generality of this phenomenon with multiple independent iPSCs lines, various thiol-based antioxidants and distinct GSK3 inhibitors. Mechanistically, we demonstrated that rapamycin treatment could substantially reduce cell death, suggesting the critical role of mammalian target of rapamycin (mTOR). Akt dysregulation was also found to partially contribute to cell apoptosis but was not the primary cause. Further, this coordinated proapoptotic effect was not detected in mouse ESCs but was present in another human cells line: a breast cancer cell line (MDA-MB-231). Given the wide use of GSK3 inhibition in biomedical research: from iPSC differentiation to cancer intervention and the treatment of neuronal diseases, researchers can potentially take advantage of or avoid this synergistic effect for improved experimental or clinical outcome. Copyright © 2017. Published by Elsevier B.V.

  3. KAEMPFEROL, A FLAVONOID COMPOUND FROM GYNURA MEDICA INDUCED APOPTOSIS AND GROWTH INHIBITION IN MCF-7 BREAST CANCER CELL

    OpenAIRE

    Yi, Xiaofang; Zuo, Jiangcheng; Tan, Chao; Xian, Sheng; Luo, Chunhua; Chen, Sai; Yu, Liangfang; Luo, Yucheng

    2016-01-01

    Background: Kaempferol, a natural flavonoid, has been shown to induce cancer cell apoptosis and cell growth inhibition in several tumors. Previously we have conducted a full investigation on the chemical constituents of Gynura medica, kaempferol and its glycosides are the major constituents of G. medica. Here we investigated the growth inhibition and apoptosis induction effect of kaempferol extracted from G. medica. Materials and Methods: The inhibition effects of kaempferol were evaluated by...

  4. The novel Akt inhibitor API-1 induces c-FLIP degradation and synergizes with TRAIL to augment apoptosis independent of Akt inhibition.

    Science.gov (United States)

    Li, Bo; Ren, Hui; Yue, Ping; Chen, Mingwei; Khuri, Fadlo R; Sun, Shi-Yong

    2012-04-01

    API-1 (pyrido[2,3-d]pyrimidines) is a novel small-molecule inhibitor of Akt, which acts by binding to Akt and preventing its membrane translocation and has promising preclinical antitumor activity. In this study, we reveal a novel function of API-1 in regulation of cellular FLICE-inhibitory protein (c-FLIP) levels and TRAIL-induced apoptosis, independent of Akt inhibition. API-1 effectively induced apoptosis in tested cancer cell lines including activation of caspase-8 and caspase-9. It reduced the levels of c-FLIP without increasing the expression of death receptor 4 (DR4) or DR5. Accordingly, it synergized with TRAIL to induce apoptosis. Enforced expression of ectopic c-FLIP did not attenuate API-1-induced apoptosis but inhibited its ability to enhance TRAIL-induced apoptosis. These data indicate that downregulation of c-FLIP mediates enhancement of TRAIL-induced apoptosis by API-1 but is not sufficient for API-1-induced apoptosis. API-1-induced reduction of c-FLIP could be blocked by the proteasome inhibitor MG132. Moreover, API-1 increased c-FLIP ubiquitination and decreased c-FLIP stability. These data together suggest that API-1 downregulates c-FLIP by facilitating its ubiquitination and proteasome-mediated degradation. Because other Akt inhibitors including API-2 and MK2206 had minimal effects on reducing c-FLIP and enhancement of TRAIL-induced apoptosis, it is likely that API-1 reduces c-FLIP and enhances TRAIL-induced apoptosis independent of its Akt-inhibitory activity. 2012 AACR

  5. Blockade of store-operated calcium entry alleviates high glucose-induced neurotoxicity via inhibiting apoptosis in rat neurons.

    Science.gov (United States)

    Xu, Zhenkuan; Xu, Wenzhe; Song, Yan; Zhang, Bin; Li, Feng; Liu, Yuguang

    2016-07-25

    Altered store-operated calcium entry (SOCE) has been suggested to be involved in many diabetic complications. However, the association of altered SOCE and diabetic neuronal damage remains unclear. This study aimed to investigate the effects of altered SOCE on primary cultured rat neuron injury induced by high glucose. Our data demonstrated that high glucose increased rat neuron injury and upregulated the expression of store-operated calcium channel (SOC). Inhibition of SOCE by a pharmacological inhibitor and siRNA knockdown of stromal interaction molecule 1 weakened the intracellular calcium overload, restored mitochondrial membrane potential, downregulated cytochrome C release and inhibited cell apoptosis. As well, treatment with the calcium chelator BAPTA-AM prevented cell apoptosis by ameliorating the high glucose-increased intracellular calcium level. These findings suggest that SOCE blockade may alleviate high glucose-induced neuronal damage by inhibiting apoptosis. SOCE might be a promising therapeutic target in diabetic neurotoxicity. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  6. [Interleukin-37 induces apoptosis and autophagy of SMMC-7721 cells by inhibiting phosphorylation of mTOR].

    Science.gov (United States)

    Li, Tingting; Zhu, Di; Mou, Tong; Guo, Zhen; Pu, Junliang; Wu, Zhongjun

    2017-04-01

    Objective To investigate the underlying mechanism by which interleukin-37 (IL-37) induces the apoptosis and autophagy in SMMC-7721 cells. Methods SMMC-7721 cells were incubated in vitro and divided into two groups, IL-37 treated group and control group. The cells were treated with (50, 100, 200) ng/mL of recombinant human interleukin-37 (rhIL-37). CCK-8 assay was used to detect the cell proliferation of SMMC-7721 cells. Cell apoptosis was measured by flow cytometry. Western blot analysis was performed to examine the expressions of apoptosis-related proteins, Bax, Bcl-2, and autophagy related proteins, microtubule-associated proteins 1 light chain 3 (LC3), beclin 1 and mammalian target of rapamycin (mTOR). Transmission electron microscopy (TEM) was used to observe the ultrastructures of autophagosomes. Results The rhIL-37 inhibited the proliferation of hepatocellular carcinoma SMMC-7721 cells. It induced the apoptosis and autophagy in SMMC-7721 cells. In the IL-37 treated group, the levels of Bax, LC3 and beclin 1 increased but Bcl-2 decreased. The phosphorylation of mTOR was inhibited in the IL-37 treated group. Autophagosome was obvious in the IL-37 treated group. Conclusion IL-37 induces the apoptosis and autophagy in SMMC-7721 cells, which may be related to the phosphorylation of mTOR.

  7. Atorvastatin prevents Aβ oligomer-induced neurotoxicity in cultured rat hippocampal neurons by inhibiting Tau cleavage

    Science.gov (United States)

    Sui, Hai-juan; Zhang, Ling-ling; Liu, Zhou; Jin, Ying

    2015-01-01

    Aim: The proteolytic cleavage of Tau is involved in Aβ-induced neuronal dysfunction and cell death. In this study, we investigated whether atorvastatin could prevent Tau cleavage and hence prevent Aβ1–42 oligomer (AβO)-induced neurotoxicity in cultured cortical neurons. Methods: Cultured rat hippocampal neurons were incubated in the presence of AβOs (1.25 μmol/L) with or without atorvastatin pretreatment. ATP content and LDH in the culture medium were measured to assess the neuronal viability. Caspase-3/7 and calpain protease activities were detected. The levels of phospho-Akt, phospho-Erk1/2, phospho-GSK3β, p35 and Tau proteins were measured using Western blotting. Results: Treatment of the neurons with AβO significantly decreased the neuronal viability, induced rapid activation of calpain and caspase-3/7 proteases, accompanied by Tau degradation and relatively stable fragments generated in the neurons. AβO also suppressed Akt and Erk1/2 kinase activity, while increased GSK3β and Cdk5 activity in the neurons. Pretreatment with atorvastatin (0.5, 1, 2.5 μmol/L) dose-dependently inhibited AβO-induced activation of calpain and caspase-3/7 proteases, and effectively diminished the generation of Tau fragments, attenuated synaptic damage and increased neuronal survival. Atorvastatin pretreatment also prevented AβO-induced decreases in Akt and Erk1/2 kinase activity and the increases in GSK3β and Cdk5 kinase activity. Conclusion: Atorvastatin prevents AβO-induced neurotoxicity in cultured rat hippocampal neurons by inhibiting calpain- and caspase-mediated Tau cleavage. PMID:25891085

  8. TFF1 inhibits proliferation and induces apoptosis of gastric cancer cells in vitro

    Directory of Open Access Journals (Sweden)

    Yanli Ge

    2012-05-01

    Full Text Available Trefoil Factor Family (TFF plays an essential role in the intestinal epithelial restitution, but the relationship between TFF1 and gastric cancer (GC is still unclear. The present study aimed to determine the role of TFF1 in repairing gastric mucosa and in the pathogenesis of GC.The TFF1 expression in different gastric mucosas was measured with immunohistochemistry. Then, siRNA targeting TFF1 or plasmids expressing TFF1 gene were transfected into BGC823 cells, SGC7901 cells and GES-1 cells. The cell proliferation was detected with MTT assay and apoptosis and cell cycle measured by flow cytometry.From normal gastric mucosa to mucosa with dysplasia and to gastric cancer, the TFF1 expression had a decreasing trend. Down-regulation of TFF1 expression significantly reduced the apoptosis of three cell lines and markedly facilitated their proliferation but had no significant effect on cell cycle. Over-expression of TFF1 could promote apoptosis of three cell lines and inhibit proliferation but had no pronounced effect on cell cycle. TFF1 can inhibit proliferation and induce apoptosis of GC cells in vitro.

  9. Calpain inhibition reduces NMDA receptor rundown in rat substantia nigra dopamine neurons.

    Science.gov (United States)

    Zhao, Jerry; Baudry, Michel; Jones, Susan

    2018-05-04

    Repeated activation of N-Methyl-d-aspartate receptors (NMDARs) causes a Ca 2+ -dependent reduction in NMDAR-mediated current in dopamine (DA) neurons of the substantia nigra pars compacta (SNc) in one week old rats; however, a Ca 2+ -dependent regulatory protein has not been identified. The role of the Ca 2+ -dependent cysteine protease, calpain, in mediating NMDAR current rundown was investigated. In brain slices from rats aged postnatal day 7-9 ('P7'), bath application of either of the membrane permeable calpain inhibitors, N-Acetyl-L-leucyl-L-leucyl-L-norleucinal (ALLN, 20 μM) or MDL-28170 (30 μM) significantly reduced whole-cell NMDAR current rundown. To investigate the role of the calpain-2 isoform, the membrane permeable calpain-2 inhibitor, Z-Leu-Abu-CONH-CH2-C6H3 (3, 5-(OMe)2 (C2I, 200 nM), was applied; C2I application significantly reduced whole cell NMDAR current rundown. Interestingly, ALLN but not C2I significantly reduced rundown of NMDA-EPSCs. These results suggest the calpain-2 isoform mediates Ca 2+ -dependent regulation of extrasynaptic NMDAR current in the first postnatal week, while calpain-1 might mediate rundown of synaptic NMDAR currents. One week later in postnatal development, at P12-P16 ('P14'), there was significantly less rundown in SNc-DA neurons, and no significant effect on rundown of either Ca 2+ chelation or treatment with the calpain inhibitor, ALLN, suggesting that the rundown observed in SNc-DA neurons from two week-old rats might be Ca 2+ -independent. In conclusion, Ca 2+ -dependent rundown of extrasynaptic NMDAR currents in SNc DA neurons involves calpain-2 activation, but Ca 2+ - and calpain-2-dependent NMDAR current rundown is developmentally regulated. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Traditional Chinese Medicine CFF-1 induced cell growth inhibition, autophagy, and apoptosis via inhibiting EGFR-related pathways in prostate cancer.

    Science.gov (United States)

    Wu, Zhaomeng; Zhu, Qingyi; Yin, Yingying; Kang, Dan; Cao, Runyi; Tian, Qian; Zhang, Yu; Lu, Shan; Liu, Ping

    2018-04-01

    Traditional Chinese medicine (TCM) has a combined therapeutic result in cancer treatment by integrating holistic and local therapeutical effects, by which TCM can enhance the curative effect and reduce the side effect. In this study, we analyzed the effect of CFF-1 (alcohol extract from an anticancer compound Chinese medicine) on prostate cancer (PCa) cell lines and studied in detail the mechanism of cell death induced by CFF-1 in vitro and in vivo. From our data, we found for the first time that CFF-1 obviously arrested cell cycle in G1 phase, decreased cell viability and then increased nuclear rupture in a dose-dependent manner and finally resulted in apoptosis in prostate cancer cells. In molecular level, our data showed that CFF-1 induced inhibition of EGFR auto-phosphorylation and inactivation of EGFR. Disruption of EGFR activity in turn suppressed downstream PI3K/AKT and Raf/Erk signal pathways, resulted in the decrease of p-FOXO1 (Ser256) and regulated the expression of apoptosis-related and cycle-related genes. Moreover, CFF-1 markedly induced cell autophagy through inhibiting PI3K/AKT/mTOR pathway and then up-regulating Beclin-1 and LC-3II and down-regulating phosphorylation of p70S6K. In vivo, CFF-1-treated group exhibited a significant decrease in tumor volume compared with the negative control group in subcutaneous xenograft tumor in nude mice via inhibiting EGFR-related signal pathways. Thus, bio-functions of Chinese medicine CFF-1 in inducing PCa cell growth inhibition, autophagy, and apoptosis suggested that CFF-1 had the clinical potential to treat patients with prostate cancer. © 2018 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

  11. Taurine inhibits 2,5-hexanedione-induced oxidative stress and mitochondria-dependent apoptosis in PC12 cells.

    Science.gov (United States)

    Li, Shuangyue; Guan, Huai; Qian, Zhiqiang; Sun, Yijie; Gao, Chenxue; Li, Guixin; Yang, Yi; Piao, Fengyuan; Hu, Shuhai

    2017-04-07

    2,5-hexanedione (HD) is the ultimate neurotoxic metabolite of hexane, causing the progression of nerve diseases in human. It was reported that HD induced apoptosis and oxidative stress. Taurine has been shown to be a potent antioxidant. In the present study, we investigated the protection of taurine against HD-induced apoptosis in PC12 cells and the underlying mechanism. Our results showed the decreased viability and increased apoptosis in HD-exposed PC12 cells. HD also induced the disturbance of Bax and Bcl-2 expression, the loss of MMP, the release of mitochondrial cytochrome c and caspase-3 activation in PC12 cells. Moreover, HD resulted in an increase in reactive oxygen species (ROS) level and a decline in the activities of superoxidedismutase and catalase in PC12 cells. However, taurine pretreatment ameliorated the increased apoptosis and the alterations in key regulators of mitochondria-dependent pathway in PC12 exposed to HD. The increased ROS level and the decreased activities of the antioxidant enzymes in HD group were attenuated by taurine. These results indicate that pretreatment of taurine may, at least partly, prevent HD-induced apoptosis via inhibiting mitochondria-dependent pathway. It is also suggested that the potential of taurine against HD-induced apoptosis may benefit from its anti-oxidative property.

  12. SCGB3A2 Inhibits Acrolein-Induced Apoptosis through Decreased p53 Phosphorylation.

    Science.gov (United States)

    Kurotani, Reiko; Shima, Reika; Miyano, Yuki; Sakahara, Satoshi; Matsumoto, Yoshie; Shibata, Yoko; Abe, Hiroyuki; Kimura, Shioko

    2015-04-28

    Chronic obstructive pulmonary disease (COPD), a major global health problem with increasing morbidity and mortality rates, is anticipated to become the third leading cause of death worldwide by 2020. COPD arises from exposure to cigarette smoke. Acrolein, which is contained in cigarette smoke, is the most important risk factor for COPD. It causes lung injury through altering apoptosis and causes inflammation by augmenting p53 phosphorylation and producing reactive oxygen species (ROS). Secretoglobin (SCGB) 3A2, a secretory protein predominantly present in the epithelial cells of the lungs and trachea, is a cytokine-like small molecule having anti-inflammatory, antifibrotic, and growth factor activities. In this study, the effect of SCGB3A2 on acrolein-related apoptosis was investigated using the mouse fibroblast cell line MLg as the first step in determining the possible therapeutic value of SCGB3A2 in COPD. Acrolein increased the production of ROS and phosphorylation of p53 and induced apoptosis in MLg cells. While the extent of ROS production induced by acrolein was not affected by SCGB3A2, p53 phosphorylation was significantly decreased by SCGB3A2. These results demonstrate that SCGB3A2 inhibited acrolein-induced apoptosis through decreased p53 phosphorylation, not altered ROS levels.

  13. SCGB3A2 Inhibits Acrolein-Induced Apoptosis through Decreased p53 Phosphorylation

    International Nuclear Information System (INIS)

    Kurotani, Reiko; Shima, Reika; Miyano, Yuki; Sakahara, Satoshi; Matsumoto, Yoshie; Shibata, Yoko; Abe, Hiroyuki; Kimura, Shioko

    2015-01-01

    Chronic obstructive pulmonary disease (COPD), a major global health problem with increasing morbidity and mortality rates, is anticipated to become the third leading cause of death worldwide by 2020. COPD arises from exposure to cigarette smoke. Acrolein, which is contained in cigarette smoke, is the most important risk factor for COPD. It causes lung injury through altering apoptosis and causes inflammation by augmenting p53 phosphorylation and producing reactive oxygen species (ROS). Secretoglobin (SCGB) 3A2, a secretory protein predominantly present in the epithelial cells of the lungs and trachea, is a cytokine-like small molecule having anti-inflammatory, antifibrotic, and growth factor activities. In this study, the effect of SCGB3A2 on acrolein-related apoptosis was investigated using the mouse fibroblast cell line MLg as the first step in determining the possible therapeutic value of SCGB3A2 in COPD. Acrolein increased the production of ROS and phosphorylation of p53 and induced apoptosis in MLg cells. While the extent of ROS production induced by acrolein was not affected by SCGB3A2, p53 phosphorylation was significantly decreased by SCGB3A2. These results demonstrate that SCGB3A2 inhibited acrolein-induced apoptosis through decreased p53 phosphorylation, not altered ROS levels

  14. Safrole oxide induces neuronal apoptosis through inhibition of integrin beta4/SOD activity and elevation of ROS/NADPH oxidase activity.

    Science.gov (United States)

    Su, Le; Zhao, BaoXiang; Lv, Xin; Wang, Nan; Zhao, Jing; Zhang, ShangLi; Miao, JunYing

    2007-02-20

    Neuronal apoptosis is a very important event in the development of the central nervous system (CNS), but the underlying mechanisms remain to be elucidated. We have previously shown that safrole oxide, a small molecule, induces integrin beta4 expression and promotes apoptosis in vascular endothelial cells. In this study, the effects of safrole oxide on cell growth and apoptosis have been examined in primary cultures of mouse neurons. Safrole oxide was found to significantly inhibit neuronal cell growth and to induce apoptosis. The inhibitory and apoptotic activities of safrole oxide followed a dose- and time-dependent manner. Interestingly, the expression of integrin beta4 was significantly inhibited with safrole oxide treatment. Furthermore, safrole oxide dramatically increases the level of intracellular reactive oxygen species (ROS) and the activity of NADPH oxidase. Moreover, manganese-dependent superoxide dismutase (MnSOD) activity was decreased significantly with safrole oxide treatment. Our study thus demonstrates that safrole oxide induces neuronal apoptosis through integrin beta4, ROS, NADPH, and MnSOD.

  15. [Arginase inhibitor nor-NOHA induces apoptosis and inhibits invasion and migration of HepG2 cells].

    Science.gov (United States)

    Li, Xiangnan; Zhu, Fangyu; He, Yongsong; Luo, Fang

    2017-04-01

    Objective To investigate the cell inhibitory effect of arginase inhibitor nor-NOHA on HepG2 hepatocellular carcinoma cells and related mechanism. Methods CCK-8 assay was used to detect the cell proliferation and flow cytometry to detect the apoptosis of HepG2 cells treated with (0, 0.5, 1.0, 2.0, 3.0) ng/μL nor-NOHA. The protein levels of arginase 1 (Arg1), P53, matrix metalloproteinase-2 (MMP-2), E-cadherin (ECD) were determined by Western blotting. Real time quantitative PCR was employed to examine the changes in the mRNA level of inducible nitric oxide synthase (iNOS). Griess assay was used to measure the concentration of nitric oxide (NO) in HepG2 cells. Transwell TM assay and wound-healing assay were performed to evaluate the changes of the cell invasion and migration ability, respectively. Results nor-NOHA inhibited the proliferation and induced the apoptosis of HepG2 cells. It also decreased the expression levels of Arg1 and MMP-2, increased the expression levels of P53 and ECD as well as the production of NO; in addition, nor-NOHA inhibited the invasion and migration of HepG2 cells. Conclusion Nor-NOHA can induce cell apoptosis and inhibit the ability of invasion and migration of HepG2 cells by inhibiting Arg1, which is related with the increase of iNOS expression and the high concentration of NO.

  16. Compound K induced apoptosis via endoplasmic reticulum Ca2+ release through ryanodine receptor in human lung cancer cells

    Directory of Open Access Journals (Sweden)

    Dong-Hyun Shin

    2018-04-01

    Full Text Available Background: Extended endoplasmic reticulum (ER stress may initiate apoptotic pathways in cancer cells, and ER stress has been reported to possibly increase tumor death in cancer therapy. We previously reported that caspase-8 played an important role in compound K-induced apoptosis via activation of caspase-3 directly or indirectly through Bid cleavage, cytochrome c release, and caspase-9 activation in HL-60 human leukemia cells. The mechanisms leading to apoptosis in A549 and SK-MES-1 human lung cancer cells and the role of ER stress have not yet been understood. Methods: The apoptotic effects of compound K were analyzed using flow cytometry, and the changes in protein levels were determined using Western blot analysis. The intracellular calcium levels were monitored by staining with Fura-2/AM and Fluo-3/AM. Results: Compound K-induced ER stress was confirmed through increased phosphorylation of eIF2α and protein levels of GRP78/BiP, XBP-1S, and IRE1α in human lung cancer cells. Moreover, compound-K led to the accumulation of intracellular calcium and an increase in m-calpain activities that were both significantly inhibited by pretreatment either with BAPTA-AM (an intracellular Ca2+ chelator or dantrolene (an RyR channel antagonist. These results were correlated with the outcome that compound K induced ER stress-related apoptosis through caspase-12, as z-ATAD-fmk (a specific inhibitor of caspase-12 partially ameliorated this effect. Interestingly, 4-PBA (ER stress inhibitor dramatically improved the compound K-induced apoptosis. Conclusion: Cell survival and intracellular Ca2+ homeostasis during ER stress in human lung cancer cells are important factors in the induction of the compound K-induced apoptotic pathway. Keywords: apoptosis, calcium, compound K, ER stress, lung cancer cells

  17. Verocytotoxin-induced apoptosis of human microvascular endothelial cells.

    Science.gov (United States)

    Pijpers, A H; van Setten, P A; van den Heuvel, L P; Assmann, K J; Dijkman, H B; Pennings, A H; Monnens, L A; van Hinsbergh, V W

    2001-04-01

    The pathogenesis of the epidemic form of hemolytic uremic syndrome is characterized by endothelial cell damage. In this study, the role of apoptosis in verocytotoxin (VT)-mediated endothelial cell death in human glomerular microvascular endothelial cells (GMVEC), human umbilical vein endothelial cells, and foreskin microvascular endothelial cells (FMVEC) was investigated. VT induced apoptosis in GMVEC and human umbilical vein endothelial cells when the cells were prestimulated with the inflammatory mediator tumor necrosis factor-alpha (TNF-alpha). FMVEC displayed strong binding of VT and high susceptibility to VT under basal conditions, which made them suitable for the study of VT-induced apoptosis without TNF-alpha interference. On the basis of functional (flow cytometry and immunofluorescence microscopy using FITC-conjugated annexin V and propidium iodide), morphologic (transmission electron microscopy), and molecular (agarose gel electrophoresis of cellular DNA fragments) criteria, it was documented that VT induced programmed cell death in microvascular endothelial cells in a dose- and time-dependent manner. Furthermore, whereas partial inhibition of protein synthesis by VT was associated with a considerable number of apoptotic cells, comparable inhibition of protein synthesis by cycloheximide was not. This suggests that additional pathways, independent of protein synthesis inhibition, may be involved in VT-mediated apoptosis in microvascular endothelial cells. Specific inhibition of caspases by Ac-Asp-Glu-Val-Asp-CHO, but not by Ac-Tyr-Val-Ala-Asp-CHO, was accompanied by inhibition of VT-induced apoptosis in FMVEC and TNF-alpha-treated GMVEC. These data indicate that VT can induce apoptosis in human microvascular endothelial cells.

  18. Apoptosis-inducing factor (Aif1) mediates anacardic acid-induced apoptosis in Saccharomyces cerevisiae.

    Science.gov (United States)

    Muzaffar, Suhail; Chattoo, Bharat B

    2017-03-01

    Anacardic acid is a medicinal phytochemical that inhibits proliferation of fungal as well as several types of cancer cells. It induces apoptotic cell death in various cell types, but very little is known about the mechanism involved in the process. Here, we used budding yeast Saccharomyces cerevisiae as a model to study the involvement of some key elements of apoptosis in the anacardic acid-induced cell death. Plasma membrane constriction, chromatin condensation, DNA degradation, and externalization of phosphatidylserine (PS) indicated that anacardic acid induces apoptotic cell death in S. cerevisiae. However, the exogenous addition of broad-spectrum caspase inhibitor Z-VAD-FMK or deletion of the yeast caspase Yca1 showed that the anacardic acid-induced cell death is caspase independent. Apoptosis-inducing factor (AIF1) deletion mutant was resistant to the anacardic acid-induced cell death, suggesting a key role of Aif1. Overexpression of Aif1 made cells highly susceptible to anacardic acid, further confirming that Aif1 mediates anacardic acid-induced apoptosis. Interestingly, instead of the increase in the intracellular reactive oxygen species (ROS) normally observed during apoptosis, anacardic acid caused a decrease in the intracellular ROS levels. Quantitative real-time PCR analysis showed downregulation of the BIR1 survivin mRNA expression during the anacardic acid-induced apoptosis.

  19. Inhibitors of nuclear factor kappa B cause apoptosis in cultured macrophages

    Directory of Open Access Journals (Sweden)

    E. E. Mannick

    1997-01-01

    Full Text Available The precise role of the transcription factor nuclear factor kappa B (NF- κB in the regulation of cell survival and cell death is still unresolved and may depend on cell type and position in the cell cycle. The aim of this study was to determine if three pharmacologic inhibitors of NF-κB, pyrrolidine dithiocarbamate, N-tosyl-L-lysl chloromethyl ketone and calpain I inhibitor, induce apoptosis in a murine macrophage cell line (RAW 264.7 at doses similar to those required for NF-κB inhibition. We found that each of the three inhibitors resulted in a dose- and time-dependent increase in morphologic indices of apoptosis in unstimulated, LPS-stimulated and TNF-stimulated cells. Lethal doses were consistent with those required for NF- κB inhibition. We conclude that nuclear NF-κB activation may represent an important survival mechanism in macrophages.

  20. CR108, a novel vitamin K3 derivative induces apoptosis and breast tumor inhibition by reactive oxygen species and mitochondrial dysfunction.

    Science.gov (United States)

    Yang, Chun-Ru; Liao, Wei-Siang; Wu, Ya-Hui; Murugan, Kaliyappan; Chen, Chinpiao; Chao, Jui-I

    2013-12-15

    Vitamin K3 derivatives have been shown to exert anticancer activities. Here we show a novel vitamin K3 derivative (S)-2-(2-hydroxy-3-methylbutylthio)naphthalene-1,4-dione, which is named as CR108 that induces apoptosis and tumor inhibition through reactive oxygen species (ROS) and mitochondrial dysfunction in human breast cancer. CR108 is more effective on the breast cancer cell death than other vitamin K3 derivatives. Moreover, CR108 induced apoptosis in both the non-HER-2-overexpressed MCF-7 and HER-2-overexpressed BT-474 breast cancer cells. CR108 caused the loss of mitochondrial membrane potential, cytochrome c released from mitochondria to cytosol, and cleaved PARP proteins for apoptosis induction. CR108 markedly increased ROS levels in breast cancer cells. N-acetylcysteine (NAC), a general ROS scavenger, completely blocked the CR108-induced ROS levels, mitochondrial dysfunction and apoptosis. Interestingly, CR108 increased the phosphorylation of p38 MAP kinase but conversely inhibited the survivin protein expression. NAC treatment prevented the activation of p38 MAP kinase and rescued the survivin protein levels. SB202190, a specific p38 MAP kinase inhibitor, recovered the survivin protein levels and attenuated the cytotoxicity of CR108-treated cells. Furthermore, CR108 inhibited the xenografted human breast tumor growth in nude mice. Together, we demonstrate that CR108 is a novel vitamin K3 derivative that induces apoptosis and tumor inhibition by ROS production and mitochondrial dysfunction and associates with the phosphorylation of p38 MAP kinase and the inhibition of survivin in the human breast cancer. © 2013.

  1. γ-Tocotrienol Inhibits Proliferation and Induces Apoptosis via the Mitochondrial Pathway in Human Cervical Cancer HeLa Cells

    Directory of Open Access Journals (Sweden)

    Weili Xu

    2017-08-01

    Full Text Available γ-Tocotrienol, a kind of isoprenoid phytochemical, has antitumor activity. However, there is limited evidence that it has an effect on cervical cancer. In this study, the capacity to inhibit proliferation and induce apoptosis in human cervical cancer HeLa cells and the mechanism underlying these effects were examined. The results indicated that a γ-tocotrienol concentration over 30 μM inhibited the growth of HeLa cells with a 50% inhibitory concentration (IC50 of 46.90 ± 3.50 μM at 24 h, and significantly down-regulated the expression of proliferative cell nuclear antigen (PCNA and Ki-67. DNA flow cytometric analysis indicated that γ-tocotrienol arrested the cell cycle at G0/G1 phase and reduced the S phase in HeLa cells. γ-tocotrienol induced apoptosis of HeLa cells in a time- and dose-dependent manner. γ-tocotrienol-induced apoptosis in HeLa cells was accompanied by down-regulation of Bcl-2, up-regulation of Bax, release of cytochrome from mitochondria, activation of caspase-9 and caspase-3, and subsequent poly (ADP-ribose polymerase (PARP cleavage. These results suggested that γ-tocotrienol could significantly inhibit cell proliferation through G0/G1 cell cycle arrest, and induce apoptosis via the mitochondrial apoptotic pathway in human cervical cancer HeLa cells. Thus, our findings revealed that γ-tocotrienol may be considered as a potential agent for cervical cancer therapy.

  2. γ-Tocotrienol Inhibits Proliferation and Induces Apoptosis Via the Mitochondrial Pathway in Human Cervical Cancer HeLa Cells.

    Science.gov (United States)

    Xu, Weili; Mi, Yaqing; He, Pan; He, Shenghua; Niu, Lingling

    2017-08-04

    γ-Tocotrienol, a kind of isoprenoid phytochemical, has antitumor activity. However, there is limited evidence that it has an effect on cervical cancer. In this study, the capacity to inhibit proliferation and induce apoptosis in human cervical cancer HeLa cells and the mechanism underlying these effects were examined. The results indicated that a γ-tocotrienol concentration over 30 μM inhibited the growth of HeLa cells with a 50% inhibitory concentration (IC 50 ) of 46.90 ± 3.50 μM at 24 h, and significantly down-regulated the expression of proliferative cell nuclear antigen (PCNA) and Ki-67. DNA flow cytometric analysis indicated that γ-tocotrienol arrested the cell cycle at G0/G1 phase and reduced the S phase in HeLa cells. γ-tocotrienol induced apoptosis of HeLa cells in a time- and dose-dependent manner. γ-tocotrienol-induced apoptosis in HeLa cells was accompanied by down-regulation of Bcl-2, up-regulation of Bax, release of cytochrome from mitochondria, activation of caspase-9 and caspase-3, and subsequent poly (ADP-ribose) polymerase (PARP) cleavage. These results suggested that γ-tocotrienol could significantly inhibit cell proliferation through G0/G1 cell cycle arrest, and induce apoptosis via the mitochondrial apoptotic pathway in human cervical cancer HeLa cells. Thus, our findings revealed that γ-tocotrienol may be considered as a potential agent for cervical cancer therapy.

  3. Edaravone protects endotoxin-induced liver injury by inhibiting apoptosis and reducing proinflammatory cytokines.

    Science.gov (United States)

    Zong, L; Yu, Q H; Du, Y X; Deng, X M

    2014-02-01

    Studies have shown that edaravone may prevent liver injury. This study aimed to investigate the effects of edaravone on the liver injury induced by D-galactosamine (GalN) and lipopolysaccharide (LPS) in female BALB/c mice. Edaravone was injected into mice 30 min before and 4 h after GalN/LPS injection. The survival rate was determined within the first 24 h. Animals were killed 8 h after GalN/LPS injection, and liver injury was biochemically and histologically assessed. Hepatocyte apoptosis was measured by TUNEL staining; proinflammatory cytokines [tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6)] in the liver were assayed by ELISA; expression of caspase-8 and caspase-3 proteins was detected by Western blot assay; and caspase-3 activity was also determined. Results showed that GalN/LPS induced marked elevations in serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Edaravone significantly inhibited elevation of serum AST and ALT, accompanied by an improvement in histological findings. Edaravone lowered the levels of TNF-α and IL-6 and reduced the number of TUNEL-positive cells. In addition, 24 h after edaravone treatment, caspase-3 activity and mortality were reduced. Edaravone may effectively ameliorate GalN/LPS-induced liver injury in mice by reducing proinflammatory cytokines and inhibiting apoptosis.

  4. Edaravone protects endotoxin-induced liver injury by inhibiting apoptosis and reducing proinflammatory cytokines

    Energy Technology Data Exchange (ETDEWEB)

    Zong, L. [Second Military Medical University, Changhai Hospital, Department of Anesthesiology, Shanghai, China, Department of Anesthesiology, Changhai Hospital, Second Military Medical University, Shanghai (China); No. 82 Hospital of People' s Liberation Army, Department of Anesthesiology, Jiangsu, China, Department of Anesthesiology, No. 82 Hospital of People' s Liberation Army, Jiangsu (China); Yu, Q. H. [Second Military Medical University, Changhai Hospital, Department of Gastroenterology, Shanghai, China, Department of Gastroenterology, Changhai Hospital, Second Military Medical University, Shanghai (China); Du, Y. X. [No. 82 Hospital of People' s Liberation Army, Department of Anesthesiology, Jiangsu, China, Department of Anesthesiology, No. 82 Hospital of People' s Liberation Army, Jiangsu (China); Deng, X. M. [Second Military Medical University, Changhai Hospital, Department of Anesthesiology, Shanghai, China, Department of Anesthesiology, Changhai Hospital, Second Military Medical University, Shanghai (China)

    2014-03-03

    Studies have shown that edaravone may prevent liver injury. This study aimed to investigate the effects of edaravone on the liver injury induced by D-galactosamine (GalN) and lipopolysaccharide (LPS) in female BALB/c mice. Edaravone was injected into mice 30 min before and 4 h after GalN/LPS injection. The survival rate was determined within the first 24 h. Animals were killed 8 h after GalN/LPS injection, and liver injury was biochemically and histologically assessed. Hepatocyte apoptosis was measured by TUNEL staining; proinflammatory cytokines [tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6)] in the liver were assayed by ELISA; expression of caspase-8 and caspase-3 proteins was detected by Western blot assay; and caspase-3 activity was also determined. Results showed that GalN/LPS induced marked elevations in serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Edaravone significantly inhibited elevation of serum AST and ALT, accompanied by an improvement in histological findings. Edaravone lowered the levels of TNF-α and IL-6 and reduced the number of TUNEL-positive cells. In addition, 24 h after edaravone treatment, caspase-3 activity and mortality were reduced. Edaravone may effectively ameliorate GalN/LPS-induced liver injury in mice by reducing proinflammatory cytokines and inhibiting apoptosis.

  5. Edaravone protects endotoxin-induced liver injury by inhibiting apoptosis and reducing proinflammatory cytokines

    International Nuclear Information System (INIS)

    Zong, L.; Yu, Q.H.; Du, Y.X.; Deng, X.M.

    2014-01-01

    Studies have shown that edaravone may prevent liver injury. This study aimed to investigate the effects of edaravone on the liver injury induced by D-galactosamine (GalN) and lipopolysaccharide (LPS) in female BALB/c mice. Edaravone was injected into mice 30 min before and 4 h after GalN/LPS injection. The survival rate was determined within the first 24 h. Animals were killed 8 h after GalN/LPS injection, and liver injury was biochemically and histologically assessed. Hepatocyte apoptosis was measured by TUNEL staining; proinflammatory cytokines [tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6)] in the liver were assayed by ELISA; expression of caspase-8 and caspase-3 proteins was detected by Western blot assay; and caspase-3 activity was also determined. Results showed that GalN/LPS induced marked elevations in serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Edaravone significantly inhibited elevation of serum AST and ALT, accompanied by an improvement in histological findings. Edaravone lowered the levels of TNF-α and IL-6 and reduced the number of TUNEL-positive cells. In addition, 24 h after edaravone treatment, caspase-3 activity and mortality were reduced. Edaravone may effectively ameliorate GalN/LPS-induced liver injury in mice by reducing proinflammatory cytokines and inhibiting apoptosis

  6. Nur77 inhibits oxLDL induced apoptosis of macrophages via the p38 MAPK signaling pathway

    International Nuclear Information System (INIS)

    Shao, Qin; Han, Fei; Peng, Shi; He, Ben

    2016-01-01

    The interaction between macrophages and oxLDL plays a crucial role in the initiation and progression of atherosclerosis. As a key initiator in a number of plaque promoting processes, oxLDL induces variable effects such as cell apoptosis or proliferation. Orphan nuclear receptor Nur77 is potently induced in macrophages by diverse stimuli, suggesting that it is of importance in vascular inflammation resulting in atherosclerosis, but whether Nur77 induction is detrimental or protective is unclear. In our study, we explore the role of Nur77 in the regulation of oxLDL-induced macrophage apoptosis and the signaling pathways that are involved. We found that oxLDL induced Nur77 expression in a dose and time dependent fashion, and cell viability was decreased in parallel. To determine whether Nur77 induction contributes to the loss of cell viability or is a protective mechanism, the effect of Nur77 overexpression was examined. Importantly, Nur77 overexpression inhibited the oxLDL-induced decrease of cell viability, inhibited the production of apoptotic bodies and restored DNA synthesis following oxLDL exposure. Furthermore, we found that Nur77 induction is mediated through the p38 MAPK signaling pathway. After pretreatment with SB203580, cell viability was decreased, the expression of CyclinA2 and PCNA was attenuated and the percentage of cell apoptosis was enhanced. Likewise, Nur77 overexpression increased the expression of the cell cycle genes PCNA and p21, and attenuated the increase in caspase-3. On the other hand, knockdown of Nur77 expression by specific siRNA resulted in the increased expression of caspase 3. The results demonstrate that Nur77 is induced by oxLDL via the p38 MAPK signaling pathway, which is involved in the regulation of cell survival. Nur77 enhanced cell survival via suppressing apoptosis, without affecting cell proliferation of activated macrophages, which may be beneficial in patients with atherosclerosis. - Highlights: • oxLDL could induce Nur77

  7. Nur77 inhibits oxLDL induced apoptosis of macrophages via the p38 MAPK signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Qin; Han, Fei; Peng, Shi; He, Ben, E-mail: heben@medmail.com.cn

    2016-03-18

    The interaction between macrophages and oxLDL plays a crucial role in the initiation and progression of atherosclerosis. As a key initiator in a number of plaque promoting processes, oxLDL induces variable effects such as cell apoptosis or proliferation. Orphan nuclear receptor Nur77 is potently induced in macrophages by diverse stimuli, suggesting that it is of importance in vascular inflammation resulting in atherosclerosis, but whether Nur77 induction is detrimental or protective is unclear. In our study, we explore the role of Nur77 in the regulation of oxLDL-induced macrophage apoptosis and the signaling pathways that are involved. We found that oxLDL induced Nur77 expression in a dose and time dependent fashion, and cell viability was decreased in parallel. To determine whether Nur77 induction contributes to the loss of cell viability or is a protective mechanism, the effect of Nur77 overexpression was examined. Importantly, Nur77 overexpression inhibited the oxLDL-induced decrease of cell viability, inhibited the production of apoptotic bodies and restored DNA synthesis following oxLDL exposure. Furthermore, we found that Nur77 induction is mediated through the p38 MAPK signaling pathway. After pretreatment with SB203580, cell viability was decreased, the expression of CyclinA2 and PCNA was attenuated and the percentage of cell apoptosis was enhanced. Likewise, Nur77 overexpression increased the expression of the cell cycle genes PCNA and p21, and attenuated the increase in caspase-3. On the other hand, knockdown of Nur77 expression by specific siRNA resulted in the increased expression of caspase 3. The results demonstrate that Nur77 is induced by oxLDL via the p38 MAPK signaling pathway, which is involved in the regulation of cell survival. Nur77 enhanced cell survival via suppressing apoptosis, without affecting cell proliferation of activated macrophages, which may be beneficial in patients with atherosclerosis. - Highlights: • oxLDL could induce Nur77

  8. Down-regulation of ATF2 in the inhibition of T-2-toxin-induced chondrocyte apoptosis by selenium chondroitin sulfate nanoparticles

    Science.gov (United States)

    Han, Jing; Guo, Xiong

    2013-12-01

    Selenium chondroitin sulfate nanoparticles (SeCS) with a size range of 30-200 nm were obtained in our previous study. Meanwhile, the up-regulated expression of ATF2 mRNA and protein levels could be observed in the cartilage from Kashin-Beck disease (KBD) patients. In this paper, we investigated the inhibition effect of SeCS on T-2-toxin-induced apoptosis of chondrocyte from KBD patients. Here, we found that when the chondrocytes were treated with T-2 toxin, the chondrocyte apoptosis performed in a concentration-dependent manner. The apoptosis of chondrocyte induced by T-2 toxin involved the increased levels of ATF2, JNK and p38 mRNAs and related protein expression. SeCS could partly block the T-2-toxin-induced chondrocyte apoptosis by decreasing the expression of ATF2, JNK and p38 mRNAs and p-JNK, p-38, ATF2 and p-ATF2 proteins. JNK and p38 pathways involved in the apoptosis of chondrocyte induced by T-2 toxin, and SeCS was efficient in the inhibition of chondrocyte apoptosis by T-2 toxin. These results suggested that SeCS had a potential for further prevention and treatment for KBD as well as other selenium deficiency disease.

  9. Puerariae radix isoflavones and their metabolites inhibit growth and induce apoptosis in breast cancer cells

    International Nuclear Information System (INIS)

    Lin, Y.-J.; Hou, Y.C.; Lin, C.-H.; Hsu, Y.-A.; Sheu, Jim J.C.; Lai, C.-H.; Chen, B.-H.; Lee Chao, Pei-Dawn; Wan Lei; Tsai, F.-J.

    2009-01-01

    Puerariae radix (PR) is a popular natural herb and a traditional food in Asia, which has antithrombotic and anti-allergic properties and stimulates estrogenic activity. In the present study, we investigated the effects of the PR isoflavones puerarin, daidzein, and genistein on the growth of breast cancer cells. Our data revealed that after treatment with PR isoflavones, a dose-dependent inhibition of cell growth occurred in HS578T, MDA-MB-231, and MCF-7 cell lines. Results from cell cycle distribution and apoptosis assays revealed that PR isoflavones induced cell apoptosis through a caspase-3-dependent pathway and mediated cell cycle arrest in the G2/M phase. Furthermore, we observed that the serum metabolites of PR (daidzein sulfates/glucuronides) inhibited proliferation of the breast cancer cells at a 50% cell growth inhibition (GI 50 ) concentration of 2.35 μM. These results indicate that the daidzein constituent of PR can be metabolized to daidzein sulfates or daidzein glucuronides that exhibit anticancer activities. The protein expression levels of the active forms of caspase-9 and Bax in breast cancer cells were significantly increased by treatment with PR metabolites. These metabolites also increased the protein expression levels of p53 and p21. We therefore suggest that PR may act as a chemopreventive and/or chemotherapeutic agent against breast cancer by reducing cell viability and inducing apoptosis.

  10. Free radical scavenger edaravone suppresses X-ray-induced apoptosis through p53 inhibition in MOLT-4 cells

    International Nuclear Information System (INIS)

    Sasano, Nakashi; Shiraishi, Kenshiro; Igaki, Hiroshi; Nakagawa, Keiichi; Enomoto, Atsushi; Hosoi, Yoshio; Matsumoto, Yoshihisa; Miyagawa, Kiyoshi; Katsumura, Yosuke

    2007-01-01

    Edaravone, a clinical drug used widely for the treatment of acute cerebral infarction, is reported to scavenge free radicals. In the present study, we investigated the radioprotective effect of edaravone on X-ray-induced apoptosis in MOLT-4 cells. Apoptosis was determined by the dye exclusion test, Annexin V binding assay, cleavage of caspase, and DNA fragmentation. We found that edaravone significantly suppressed the X-ray-induced apoptosis. The amount of intracellular reactive oxygen species (ROS) production was determined by the chloromethyl-2', 7'-dichlorodihydro-fluorescein diacetate system. We found that the intracellular ROS production by X-irradiation was completely suppressed by the addition of edaravone. The accumulation and phosphorylation of p53 and the expression of p21 WAF1 , a target protein of p53, which were induced by X-irradiation, were also suppressed by adding edaravone. We conclude that the free radical scavenger edaravone suppresses X-ray-induced apoptosis in MOLT-4 cells by inhibiting p53. (author)

  11. Free radical scavenger edaravone suppresses X-ray-induced apoptosis through p53 inhibition in MOLT-4 cells

    Energy Technology Data Exchange (ETDEWEB)

    Sasano, Nakashi; Shiraishi, Kenshiro; Igaki, Hiroshi; Nakagawa, Keiichi [Tokyo Univ., Graduate School of Medicine, Tokyo (Japan); Enomoto, Atsushi; Hosoi, Yoshio; Matsumoto, Yoshihisa; Miyagawa, Kiyoshi [Tokyo Univ., Faculty of Medicine, Tokyo (Japan); Katsumura, Yosuke [Tokyo Univ., Graduate School of Engineering, Tokyo (Japan)

    2007-11-15

    Edaravone, a clinical drug used widely for the treatment of acute cerebral infarction, is reported to scavenge free radicals. In the present study, we investigated the radioprotective effect of edaravone on X-ray-induced apoptosis in MOLT-4 cells. Apoptosis was determined by the dye exclusion test, Annexin V binding assay, cleavage of caspase, and DNA fragmentation. We found that edaravone significantly suppressed the X-ray-induced apoptosis. The amount of intracellular reactive oxygen species (ROS) production was determined by the chloromethyl-2', 7'-dichlorodihydro-fluorescein diacetate system. We found that the intracellular ROS production by X-irradiation was completely suppressed by the addition of edaravone. The accumulation and phosphorylation of p53 and the expression of p21{sup WAF1}, a target protein of p53, which were induced by X-irradiation, were also suppressed by adding edaravone. We conclude that the free radical scavenger edaravone suppresses X-ray-induced apoptosis in MOLT-4 cells by inhibiting p53. (author)

  12. Pharmacological inhibition of caspase and calpain proteases: a novel strategy to enhance the homing responses of cord blood HSPCs during expansion.

    Directory of Open Access Journals (Sweden)

    V M Sangeetha

    Full Text Available BACKGROUND: Expansion of hematopoietic stem/progenitor cells (HSPCs is a well-known strategy employed to facilitate the transplantation outcome. We have previously shown that the prevention of apoptosis by the inhibition of cysteine proteases, caspase and calpain played an important role in the expansion and engraftment of cord blood (CB derived HSPCs. We hypothesize that these protease inhibitors might have maneuvered the adhesive and migratory properties of the cells rendering them to be retained in the bone marrow for sustained engraftment. The current study was aimed to investigate the mechanism of the homing responses of CB cells during expansion. METHODOLOGY/PRINCIPAL FINDINGS: CB derived CD34(+ cells were expanded using a combination of growth factors with and without Caspase inhibitor -zVADfmk or Calpain 1 inhibitor- zLLYfmk. The cells were analyzed for the expression of homing-related molecules. In vitro adhesive/migratory interactions and actin polymerization dynamics of HSPCs were assessed. In vivo homing assays were carried out in NOD/SCID mice to corroborate these observations. We observed that the presence of zVADfmk or zLLYfmk (inhibitors caused the functional up regulation of CXCR4, integrins, and adhesion molecules, reflecting in a higher migration and adhesive interactions in vitro. The enhanced actin polymerization and the RhoGTPase protein expression complemented these observations. Furthermore, in vivo experiments showed a significantly enhanced homing to the bone marrow of NOD/SCID mice. CONCLUSION/SIGNIFICANCE: Our present study reveals another novel aspect of the regulation of caspase and calpain proteases in the biology of HSPCs. The priming of the homing responses of the inhibitor-cultured HSPCs compared to the cytokine-graft suggests that the modulation of these proteases may help in overcoming the major homing defects prevalent in the expansion cultures thereby facilitating the manipulation of cells for transplant

  13. Indirubin-3′-monoxime suppresses amyloid-beta-induced apoptosis by inhibiting tau hyperphosphorylation

    Institute of Scientific and Technical Information of China (English)

    Shu-gang Zhang; Xiao-shan Wang; Ying-dong Zhang; Qing Di; Jing-ping Shi; Min Qian; Li-gang Xu; Xing-jian Lin; Jie Lu

    2016-01-01

    Indirubin-3′-monoxime is an effective inhibitor of cyclin-dependent protein kinases, and may play an obligate role in neuronal apopto-sis in Alzheimer’s disease. Here, we found that indirubin-3′-monoxime improved the morphology and increased the survival rate of SH-SY5Y cells exposed to amyloid-beta 25–35 (Aβ25–35), and also suppressed apoptosis by reducing tau phosphorylation at Ser199 and Thr205. Furthermore, indirubin-3′-monoxime inhibited phosphorylation of glycogen synthase kinase-3β (GSK-3β). Our results suggest that in-dirubin-3′-monoxime reduced Aβ25–35-induced apoptosis by suppressing tau hyperphosphorylationvia a GSK-3β-mediated mechanism. Indirubin-3′-monoxime is a promising drug candidate for Alzheimer’s disease.

  14. Limonene inhibits Candida albicans growth by inducing apoptosis.

    Science.gov (United States)

    Thakre, Archana; Zore, Gajanan; Kodgire, Santosh; Kazi, Rubina; Mulange, Shradha; Patil, Rajendra; Shelar, Amruta; Santhakumari, Bayitigeri; Kulkarni, Mahesh; Kharat, Kiran; Karuppayil, Sankunny Mohan

    2018-07-01

    Anti-Candida potential of limonene was evaluated against planktonic growth, biofilm (adhesion, development and maturation) and morphogenesis of Candida albicans in this study. Limonene is a major constituent of citrus oil and most frequently used terpene in food and beverage industry due to its pleasant fragrance, nontoxic, and is generally recognized as safe (GRAS) flavoring agent as well as treatment option in many gastrointestinal diseases.Limonene exhibited excellent anti-Candida activity and was equally effective against planktonic growth of C. albicans isolates differentially susceptible to FLC (N = 35). Limonene inhibited morphogenesis significantly at low concentration. However, it showed stage dependent activity against biofilm formation, that is, it was more effective against adhesion followed by development and maturation. Limonene also exhibited excellent synergy with FLC against planktonic and biofilm growth. SWATH-MS analysis led to identification of limonene responsive proteins that provided molecular insight of its anti-Candida activity. Proteomic analysis revealed upregulation of proteins involved in cell wall glucan synthesis (Kre6); oxidative stress (Rhr2, Adh7 and Ebp1); DNA damage stress (Mbf1 and Npl3); nucleolar stress (Rpl11, Rpl7, Rpl29, Rpl15) and down regulation of cytoskeleton organization (Crn1, Pin3, Cct8, Rbl2), and so forth, in response to limonene. Limonene mediated down regulation of Tps3 indicates activation of caspase (CaMca1) and induction of apoptosis in C. albicans. These results suggest that limonene inhibits C. albicans growth by cell wall/membrane damage induced oxidative stress that leads to DNA damage resulting into modulation of cell cycle and induction of apoptosis through nucleolar stress and metacaspase dependent pathway.

  15. 3-Bromopyruvate and sodium citrate induce apoptosis in human gastric cancer cell line MGC-803 by inhibiting glycolysis and promoting mitochondria-regulated apoptosis pathway.

    Science.gov (United States)

    Guo, Xingyu; Zhang, Xiaodong; Wang, Tingan; Xian, Shulin; Lu, Yunfei

    2016-06-17

    Cancer cells are mainly dependent on glycolysis to generate adenosine triphosphate (ATP) and intermediates required for cell growth and proliferation. Thus, inhibition of glycolysis might be of therapeutic value in antitumor treatment. Our previously studies had found that both 3-bromopyruvate (BP) and sodium citrate (SCT) can inhibit tumor growth and proliferation in vitro and in vivo. However, the mechanism involved in the BP and SCT mediated antitumor activity is not entirely clear. In this work, it is demonstrated that BP inhibits the enzyme hexokinase (HK) activity and SCT suppresses the phosphofructokinase (PFK) activity respectively, both the two agents decrease viability, ATP generation and lactate content in the human gastric cancer cell line MGC-803. These effects are directly correlated with blockage of glycolysis. Furthermore, BP and SCT can induce the characteristic manifestations of mitochondria-regulated apoptosis, such as down-regulation of anti-apoptosis proteins Bcl-2 and Survivin, up-regulation of pro-apoptosis protein Bax, activation of caspase-3, as well as leakage of cytochrome c (Cyt-c). In summary, our results provided evidences that BP and SCT inhibit the MGC-803 cells growth and proliferation might be correlated with inhibiting glycolysis and promoting mitochondria-regulated apoptosis. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  16. Salinomycin inhibits proliferation and induces apoptosis of human nasopharyngeal carcinoma cell in vitro and suppresses tumor growth in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Danxin; Zhang, Yu; Huang, Jie; Fan, Zirong; Shi, Fengrong; Wang, Senming, E-mail: wsenming@126.com

    2014-01-10

    Highlight: •We first evaluated the effect of salinomycin on nasopharyngeal carcinoma (NPC). •Salinomycin could inhibit Wnt/β-catenin signaling and induce apoptosis in NPC. •So salinomycin may be a good potential candidate for the chemotherapy of NPC. -- Abstract: Salinomycin (Sal) is a polyether ionophore antibiotic that has recently been shown to induce cell death in various human cancer cells. However, whether salinomycin plays a functional role in nasopharyngeal carcinoma (NPC) has not been determined to date. The present study investigated the chemotherapeutic efficacy of salinomycin and its molecular mechanisms of action in NPC cells. Salinomycin efficiently inhibited proliferation and invasion of 3 NPC cell lines (CNE-1, CNE-2, and CNE-2/DDP) and activated a extensive apoptotic process that is accompanied by activation of caspase-3 and caspase-9, and decreased mitochondrial membrane potential. Meanwhile, the protein expression level of the Wnt coreceptor lipoprotein receptor related protein 6 (LRP6) and β-catenin was down-regulated, which showed that the Wnt/β-catenin signaling was involved in salinomycin-induced apoptosis of NPC cells. In a nude mouse NPC xenograft model, the anti-tumor effect of salinomycin was associated with the downregulation of β-catenin expression. The present study demonstrated that salinomycin can effectively inhibit proliferation and invasion, and induce apoptosis of NPC cells in vitro and inhibit tumor growth in vivo, probably via the inhibition of Wnt/β-catenin signaling, suggesting salinomycin as a potential candidate for the chemotherapy of NPC.

  17. Synergistic Interactions with PI3K Inhibition that Induce Apoptosis. | Office of Cancer Genomics

    Science.gov (United States)

    Activating mutations involving the PI3K pathway occur frequently in human cancers. However, PI3K inhibitors primarily induce cell cycle arrest, leaving a significant reservoir of tumor cells that may acquire or exhibit resistance. We searched for genes that are required for the survival of PI3K mutant cancer cells in the presence of PI3K inhibition by conducting a genome scale shRNA-based apoptosis screen in a PIK3CA mutant human breast cancer cell. We identified 5 genes (PIM2, ZAK, TACC1, ZFR, ZNF565) whose suppression induced cell death upon PI3K inhibition.

  18. Overexpression of BAG3 Attenuates Hypoxia-Induced Cardiomyocyte Apoptosis by Inducing Autophagy

    Directory of Open Access Journals (Sweden)

    Jiankai Zhang

    2016-07-01

    Full Text Available Background: Hypoxia is a well-known factor in the promotion of apoptosis, which contributes to the development of numerous cardiac diseases, such as heart failure and myocardial infarction. Inhibiting apoptosis is an important therapeutic strategy for the treatment of related heart diseases caused by ischemia/hypoxic injury. Previous studies have demonstrated that BAG3 plays an important role in cardiomyocyte apoptosis and survival. However, the role of BAG3 in hypoxia-induced cardiomyocyte apoptosis remains to be clarified. Here, we demonstrate that BAG3 is induced by hypoxia stimuli in cultured cardiomyocytes. Methods: BAG3 expression level was measured in H9c2 cells treated with hypoxia for 48 h. Cell proliferation and apoptosis were tested using MTT assay and Annexin V FITC-PI staining assay, respectively. The mRNA or protein expression level of BAG3, LC3-I, LC3-II, Atg5, NF-κB p65 and phosphorylated NF-κB p65 were assessed by qRT-PCR and western blot assay, respectively. Resluts: Overexpression of BAG3 inhibited cell apoptosis and promoted proliferation in hypoxia-injured H9c2 cells. Furthermore, autophagy and NF-κB were activated by BAG3 overexpression, and the NF-κB inhibitor PDTC could inhibit the activation of autophagy induced by BAG3 overexpression. In addition, the autophagy inhibitor 3-MA partly impeded the inhibitory effect of BAG3 on hypoxia-induced cardiomyocyte apoptosis. Conclusion: these results suggested that overexpression of BAG3 promoted cell proliferation and inhibited apoptosis by activating autophagy though the NF-κB signaling pathway in hypoxia-injured cardiomyocytes.

  19. Anti-TNF-alpha antibody attenuates subarachnoid hemorrhage-induced apoptosis in the hypothalamus by inhibiting the activation of Erk

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    Ma L

    2018-02-01

    Full Text Available Ling Ma,1 Yong Jiang,2 Yanan Dong,2 Jun Gao,2 Bin Du,2 Dianwei Liu2 1Department of Clinical Laboratory, The Second Hospital of Shandong University, Jinan, Shandong, People’s Republic of China; 2Department of Neurosurgery, Jinan Central Hospital Affiliated to Shandong University, Jinan, Shandong, People’s Republic of China Background: Subarachnoid hemorrhage (SAH can induce apoptosis in many regions of the brain including the cortex and hippocampus. However, few studies have focused on apoptosis in the hypothalamus after SAH. Although some antiapoptotic strategies have been developed for SAH, such as anti-tumor necrosis factor-alpha (TNF-α antibody, the molecular mechanisms underlying this condition have yet to be elucidated. Therefore, the purpose of this study was to evaluate whether SAH could induce apoptosis in the hypothalamus and identify the potential molecular mechanisms underlying the actions of anti-TNF-α antibody, as a therapeutic regimen, upon apoptosis. Materials and methods: SAH was induced in a rat model. Thirty minutes prior to SAH, anti-TNF-α antibody or U0126, an extracellular signal-regulated kinase (Erk inhibitor, was microinjected into the left lateral cerebral ventricle. In addition, phorbol-12-myristate-13-acetate was injected intraperitoneally immediately after the anti-TNF-α antibody microinjection. Then, real-time polymerase chain reaction, Western blotting and immunohistochemistry were used to detect the expression of caspase-3, bax, bcl-2, phosphorylated Erk (p-Erk and Erk. Finally, anxiety-like behavior was identified by using open field. Results: Levels of caspase-3, bax and bcl-2, all showed a temporary rise after SAH in the hypothalamus, indicating the induction of apoptosis in this brain region. Interestingly, we found that the microinjection of anti-TNF-α antibody could selectively block the elevated levels of bax, suggesting the potential role of anti-TNF-α antibody in the inhibition of SAH-induced

  20. HSP27 Inhibits Homocysteine-Induced Endothelial Apoptosis by Modulation of ROS Production and Mitochondrial Caspase-Dependent Apoptotic Pathway

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    Xin Tian

    2016-01-01

    Full Text Available Objectives. Elevated plasma homocysteine (Hcy could lead to endothelial dysfunction and is viewed as an independent risk factor for atherosclerosis. Heat shock protein 27 (HSP27, a small heat shock protein, is reported to exert protective effect against atherosclerosis. This study aims to investigate the protective effect of HSP27 against Hcy-induced endothelial cell apoptosis in human umbilical vein endothelial cells (HUVECs and to determine the underlying mechanisms. Methods. Apoptosis, reactive oxygen species (ROS, and mitochondrial membrane potential (MMP of normal or HSP27-overexpressing HUVECs in the presence of Hcy were analyzed by flow cytometry. The mRNA and protein expression levels were measured by quantitative real-time polymerase chain reaction (qRT-PCR and western blot. Results. We found that Hcy could induce cell apoptosis with corresponding decrease of nitric oxide (NO level, increase of endothelin-1 (ET-1, intracellular adhesion molecule-1 (ICAM-1, vascular cellular adhesion molecule-1 (VCAM-1, and monocyte chemoattractant protein-1 (MCP-1 levels, elevation of ROS, and dissipation of MMP. In addition, HSP27 could protect the cell against Hcy-induced apoptosis and inhibit the effect of Hcy on HUVECs. Furthermore, HSP27 could increase the ratio of Bcl-2/Bax and inhibit caspase-3 activity. Conclusions. Therefore, we concluded that HSP27 played a protective role against Hcy-induced endothelial apoptosis through modulation of ROS production and the mitochondrial caspase-dependent apoptotic pathway.

  1. Apoptosis signal-regulating kinase 1 mediates denbinobin-induced apoptosis in human lung adenocarcinoma cells

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    Pan Shiow-Lin

    2009-05-01

    Full Text Available Abstract In the present study, we explore the role of apoptosis signal-regulating kinase 1 (ASK1 in denbinobin-induced apoptosis in human lung adenocarcinoma (A549 cells. Denbinobin-induced cell apoptosis was attenuated by an ASK1 dominant-negative mutant (ASK1DN, two antioxidants (N-acetyl-L-cysteine (NAC and glutathione (GSH, a c-Jun N-terminal kinase (JNK inhibitor (SP600125, and an activator protein-1 (AP-1 inhibitor (curcumin. Treatment of A549 cells with denbinobin caused increases in ASK1 activity and reactive oxygen species (ROS production, and these effects were inhibited by NAC and GSH. Stimulation of A549 cells with denbinobin caused JNK activation; this effect was markedly inhibited by NAC, GSH, and ASK1DN. Denbinobin induced c-Jun phosphorylation, the formation of an AP-1-specific DNA-protein complex, and Bim expression. Bim knockdown using a bim short interfering RNA strategy also reduced denbinobin-induced A549 cell apoptosis. The denbinobin-mediated increases in c-Jun phosphorylation and Bim expression were inhibited by NAC, GSH, SP600125, ASK1DN, JNK1DN, and JNK2DN. These results suggest that denbinobin might activate ASK1 through ROS production to cause JNK/AP-1 activation, which in turn induces Bim expression, and ultimately results in A549 cell apoptosis.

  2. c-Abl is an upstream regulator of acid sphingomyelinase in apoptosis induced by inhibition of integrins αvβ3 and αvβ5.

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    Xiuhai Ren

    Full Text Available Inhibition of integrins αvβ3/αvβ5 by the cyclic function-blocking peptide, RGDfV (Arg-Gly-Asp-Phe-Val can induce apoptosis in both normal cells and tumor cells. We show that RGDfV induced apoptosis in ECV-304 carcinoma cells, increased activity and mRNA expression of acid sphingomyelinase (ASM, and increased ceramides C(16, C(18:0, C(24:0 and C(24:1 while decreasing the corresponding sphingomyelins. siRNA to ASM decreased RGDfV-induced apoptosis as measured by TUNEL, PARP cleavage, mitochondrial depolarization, and caspase-3 and caspase-8 activities, as well as by annexinV in a 3D collagen model. These findings indicate a causal role for ASM in RGDfV-induced apoptosis in ECV-304. We have shown that c-Abl, a non-receptor tyrosine kinase, also mediates RGDfV-induced apoptosis. However, c-Abl, has not been previously linked to ASM in any system. Here we show that STI-571 (imatinib, inhibitor of c-Abl inhibited RGDfV-induced ASM activity. Furthermore, STI-571 and c-Abl-siRNA both inhibited RGDfV-induced increase in ASM mRNA, but ASM-siRNA did not affect c-Abl phosphorylation or expression, supporting that c-Abl regulates the RGDfV-induced increase in ASM expression. These studies implicate ASM as a mediator of apoptosis induced by inhibition of integrins αvβ3/αvβ5, and for the first time place c-Abl as an upstream regulator of ASM expression and activity.

  3. Involvement of Bcl-xL degradation and mitochondrial-mediated apoptotic pathway in pyrrolizidine alkaloids-induced apoptosis in hepatocytes

    International Nuclear Information System (INIS)

    Ji Lili; Chen Ying; Liu Tianyu; Wang Zhengtao

    2008-01-01

    Pyrrolizidine alkaloids (PAs) are natural hepatotoxins with worldwide distribution in more than 6000 high plants including medicinal herbs or teas. The aim of this study is to investigate the signal pathway involved in PAs-induced hepatotoxicity. Our results showed that clivorine, isolated from Ligularia hodgsonii Hook, decreased cell viability and induced apoptosis in L-02 cells and mouse hepatocytes. Western-blot results showed that clivorine induced caspase-3/-9 activation, mitochondrial release of cytochrome c and decreased anti-apoptotic Bcl-xL in a time (8-48 h)- and concentration (1-100 μM)-dependent manner. Furthermore, inhibitors of pan-caspase, caspase-3 and caspase-9 significantly inhibited clivorine-induced apoptosis and rescued clivorine-decreased cell viability. Polyubiquitination of Bcl-xL was detected after incubation with 100 μM clivorine for 40 h in the presence of proteasome specific inhibitor MG132, indicating possible degradation of Bcl-xL protein. Furthermore, pretreatment with MG132 or calpain inhibitor I for 2 h significantly enhanced clivorine-decreased Bcl-xL level and cell viability. All the other tested PAs such as senecionine, isoline and monocrotaline decreased mouse hepatocytes viability in a concentration-dependent manner. Clivorine (10 μM) induced caspase-3 activation and decreased Bcl-xL was also confirmed in mouse hepatocytes. Meanwhile, another PA senecionine isolated from Senecio vulgaris L also induced apoptosis, caspase-3 activation and decreased Bcl-xL in mouse hepatocytes. In conclusion, our results suggest that PAs may share the same hepatotoxic signal pathway, which involves degradation of Bcl-xL protein and thus leading to the activation of mitochondrial-mediated apoptotic pathway

  4. Edaravone protects endotoxin-induced liver injury by inhibiting apoptosis and reducing proinflammatory cytokines

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    L. Zong

    2014-03-01

    Full Text Available Studies have shown that edaravone may prevent liver injury. This study aimed to investigate the effects of edaravone on the liver injury induced by D-galactosamine (GalN and lipopolysaccharide (LPS in female BALB/c mice. Edaravone was injected into mice 30 min before and 4 h after GalN/LPS injection. The survival rate was determined within the first 24 h. Animals were killed 8 h after GalN/LPS injection, and liver injury was biochemically and histologically assessed. Hepatocyte apoptosis was measured by TUNEL staining; proinflammatory cytokines [tumor necrosis factor-α (TNF-α and interleukin-6 (IL-6] in the liver were assayed by ELISA; expression of caspase-8 and caspase-3 proteins was detected by Western blot assay; and caspase-3 activity was also determined. Results showed that GalN/LPS induced marked elevations in serum aspartate aminotransferase (AST and alanine aminotransferase (ALT. Edaravone significantly inhibited elevation of serum AST and ALT, accompanied by an improvement in histological findings. Edaravone lowered the levels of TNF-α and IL-6 and reduced the number of TUNEL-positive cells. In addition, 24 h after edaravone treatment, caspase-3 activity and mortality were reduced. Edaravone may effectively ameliorate GalN/LPS-induced liver injury in mice by reducing proinflammatory cytokines and inhibiting apoptosis.

  5. A Vitex agnus-castus extract inhibits cell growth and induces apoptosis in prostate epithelial cell lines.

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    Weisskopf, M; Schaffner, W; Jundt, G; Sulser, T; Wyler, S; Tullberg-Reinert, H

    2005-10-01

    Extracts of Vitex agnus-castus fruits (VACF) are described to have beneficial effects on disorders related to hyperprolactinemia (cycle disorders, premenstrual syndrome). A VACF extract has recently been shown to exhibit antitumor activities in different human cancer cell lines. In the present study, we explored the antiproliferative effects of a VACF extract with a particular focus on apoptosis-inducing and potential cytotoxic effects. Three different human prostate epithelial cell lines (BPH-1, LNCaP, PC-3) representing different disease stages and androgen responsiveness were chosen. The action of VACF on cell viability was assessed using the WST-8-tetrazolium assay. Cell proliferation in cells receiving VACF alone or in combination with a pan-caspase inhibitor (Z-VAD-fmk) was quantified using a Crystal Violet assay. Flow cytometric cell cycle analysis and measurement of DNA fragmentation using an ELISA method were used for studying the induction of apoptosis. Lactate dehydrogenase (LDH) activity was determined as a marker of cytotoxicity. The extract inhibited proliferation of all three cell lines in a concentration-dependent manner with IC (50) values below 10 microg/mL after treatment for 48 h. Cell cycle analysis and DNA fragmentation assays suggest that part of the cells were undergoing apoptosis. The VACF-induced decrease in cell number was partially inhibited by Z-VAD-fmk, indicating a caspase-dependent apoptotic cell death. However, the concentration-dependent LDH activity of VACF treated cells indicated cytotoxic effects as well. These data suggest that VACF contains components that inhibit proliferation and induce apoptosis in human prostate epithelial cell lines. The extract may be useful for the prevention and/or treatment not only of benign prostatic hyperplasia but also of human prostate cancer.

  6. Autotaxin is induced by TSA through HDAC3 and HDAC7 inhibition and antagonizes the TSA-induced cell apoptosis.

    Science.gov (United States)

    Li, Song; Wang, Baolu; Xu, Yan; Zhang, Junjie

    2011-02-12

    Autotaxin (ATX) is a secreted glycoprotein with the lysophospholipase D (lysoPLD) activity to convert lysophosphatidylcholine (LPC) into lysophosphatidic acid (LPA), a bioactive lysophospholipid involved in diverse biological actions. ATX is highly expressed in some cancer cells and contributes to their tumorigenesis, invasion, and metastases, while in other cancer cells ATX is silenced or expressed at low level. The mechanism of ATX expression regulation in cancer cells remains largely unknown. In the present study, we demonstrated that trichostatin A (TSA), a well-known HDAC inhibitor (HDACi), significantly induced ATX expression in SW480 and several other cancer cells with low or undetectable endogenous ATX expression. ATX induction could be observed when HDAC3 and HDAC7 were down-regulated by their siRNAs. It was found that HDAC7 expression levels were low in the cancer cells with high endogenous ATX expression. Exogenous over-expression of HDAC7 inhibited ATX expression in these cells in a HDAC3-dependent manner. These data indicate that HDAC3 and HDAC7 collaboratively suppress ATX expression in cancer cells, and suggest that TSA induce ATX expression by inhibiting HDAC3 and HDAC7. The biological significance of this regulation mechanism was revealed by demonstrating that TSA-induced ATX protected cancer cells against TSA-induced apoptosis by producing LPA through its lysoPLD activity, which could be reversed by BrP-LPA and S32826, the inhibitors of the ATX-LPA axis. We have demonstrated that ATX expression is repressed by HDAC3 and HDAC7 in cancer cells. During TSA treatment, ATX is induced due to the HDAC3 and HDAC7 inhibition and functionally antagonizes the TSA-induced apoptosis. These results reveal an internal HDACi-resistant mechanism in cancer cells, and suggest that the inhibition of ATX-LPA axis would be helpful to improve the efficacy of HDACi-based therapeutics against cancer.

  7. Isoliquiritigenin induces growth inhibition and apoptosis through downregulating arachidonic acid metabolic network and the deactivation of PI3K/Akt in human breast cancer

    International Nuclear Information System (INIS)

    Li, Ying; Zhao, Haixia; Wang, Yuzhong; Zheng, Hao; Yu, Wei; Chai, Hongyan; Zhang, Jing; Falck, John R.; Guo, Austin M.; Yue, Jiang; Peng, Renxiu; Yang, Jing

    2013-01-01

    Arachidonic acid (AA)-derived eicosanoids and its downstream pathways have been demonstrated to play crucial roles in growth control of breast cancer. Here, we demonstrate that isoliquiritigenin, a flavonoid phytoestrogen from licorice, induces growth inhibition and apoptosis through downregulating multiple key enzymes in AA metabolic network and the deactivation of PI3K/Akt in human breast cancer. Isoliquiritigenin diminished cell viability, 5-bromo-2′-deoxyuridine (BrdU) incorporation, and clonogenic ability in both MCF-7 and MDA-MB-231cells, and induced apoptosis as evidenced by an analysis of cytoplasmic histone-associated DNA fragmentation, flow cytometry and hoechst staining. Furthermore, isoliquiritigenin inhibited mRNA expression of multiple forms of AA-metabolizing enzymes, including phospholipase A2 (PLA2), cyclooxygenases (COX)-2 and cytochrome P450 (CYP) 4A, and decreased secretion of their products, including prostaglandin E 2 (PGE 2 ) and 20-hydroxyeicosatetraenoic acid (20-HETE), without affecting COX-1, 5-lipoxygenase (5-LOX), 5-lipoxygenase activating protein (FLAP), and leukotriene B 4 (LTB 4 ). In addition, it downregulated the levels of phospho-PI3K, phospho-PDK (Ser 241 ), phospho-Akt (Thr 308 ), phospho-Bad (Ser 136 ), and Bcl-x L expression, thereby activating caspase cascades and eventually cleaving poly(ADP-ribose) polymerase (PARP). Conversely, the addition of exogenous eicosanoids, including PGE 2 , LTB 4 and a 20-HETE analog (WIT003), and caspase inhibitors, or overexpression of constitutively active Akt reversed isoliquiritigenin-induced apoptosis. Notably, isoliquiritigenin induced growth inhibition and apoptosis of MDA-MB-231 human breast cancer xenografts in nude mice, together with decreased intratumoral levels of eicosanoids and phospho-Akt (Thr 308 ). Collectively, these data suggest that isoliquiritigenin induces growth inhibition and apoptosis through downregulating AA metabolic network and the deactivation of PI3K/Akt in

  8. Overexpression of BAG3 Attenuates Hypoxia-Induced Cardiomyocyte Apoptosis by Inducing Autophagy.

    Science.gov (United States)

    Zhang, Jiankai; He, Zhangyou; Xiao, Wenjian; Na, Qingqing; Wu, Tianxiu; Su, Kaixin; Cui, Xiaojun

    2016-01-01

    Hypoxia is a well-known factor in the promotion of apoptosis, which contributes to the development of numerous cardiac diseases, such as heart failure and myocardial infarction. Inhibiting apoptosis is an important therapeutic strategy for the treatment of related heart diseases caused by ischemia/hypoxic injury. Previous studies have demonstrated that BAG3 plays an important role in cardiomyocyte apoptosis and survival. However, the role of BAG3 in hypoxia-induced cardiomyocyte apoptosis remains to be clarified. Here, we demonstrate that BAG3 is induced by hypoxia stimuli in cultured cardiomyocytes. BAG3 expression level was measured in H9c2 cells treated with hypoxia for 48 h. Cell proliferation and apoptosis were tested using MTT assay and Annexin V FITC-PI staining assay, respectively. The mRNA or protein expression level of BAG3, LC3-I, LC3-II, Atg5, NF-x03BA;B p65 and phosphorylated NF-x03BA;B p65 were assessed by qRT-PCR and western blot assay, respectively. Resluts: Overexpression of BAG3 inhibited cell apoptosis and promoted proliferation in hypoxia-injured H9c2 cells. Furthermore, autophagy and NF-x03BA;B were activated by BAG3 overexpression, and the NF-x03BA;B inhibitor PDTC could inhibit the activation of autophagy induced by BAG3 overexpression. In addition, the autophagy inhibitor 3-MA partly impeded the inhibitory effect of BAG3 on hypoxia-induced cardiomyocyte apoptosis. these results suggested that overexpression of BAG3 promoted cell proliferation and inhibited apoptosis by activating autophagy though the NF-x03BA;B signaling pathway in hypoxia-injured cardiomyocytes. © 2016 The Author(s) Published by S. Karger AG, Basel.

  9. Calpain-Mediated Degradation of Drebrin by Excitotoxicity In vitro and In vivo.

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    Takahiko Chimura

    Full Text Available The level of drebrin, an evolutionarily conserved f-actin-binding protein that regulates synaptic structure and function, is reduced in the brains of patients with chronic neurodegenerative diseases such as Alzheimer's disease (AD and Down's syndrome (DS. It was suggested that excitotoxic neuronal death caused by overactivation of NMDA-type glutamate receptors (NMDARs occurs in AD and DS; however, the relationship between excitotoxicity and drebrin loss is unknown. Here, we show that drebrin is a novel target of calpain-mediated proteolysis under excitotoxic conditions induced by the overactivation of NMDARs. In cultured rodent neurons, degradation of drebrin was confirmed by the detection of proteolytic fragments, as well as a reduction in the amount of full-length drebrin. Notably, the NMDA-induced degradation of drebrin in mature neurons occurred concomitantly with a loss of f-actin. Furthermore, pharmacological inhibition of f-actin loss facilitated the drebrin degradation, suggesting a functional linkage between f-actin and drebrin degradation. Biochemical analyses using purified drebrin and calpain revealed that calpain degraded drebrin directly in vitro. Furthermore, cerebral ischemia also induced the degradation of drebrin in vivo. These findings suggest that calpain-mediated degradation of drebrin is a fundamental pathology of neurodegenerative diseases mediated by excitotoxicity, regardless of whether they are acute or chronic. Drebrin regulates the synaptic clustering of NMDARs; therefore, degradation of drebrin under excitotoxic conditions may modulate NMDAR-mediated signal transductions, including pro-survival signaling. Overall, the results presented here provide novel insights into the molecular basis of cellular responses to excitotoxicity in vitro and in vivo.

  10. 3-Bromopyruvate and sodium citrate induce apoptosis in human gastric cancer cell line MGC-803 by inhibiting glycolysis and promoting mitochondria-regulated apoptosis pathway

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    Guo, Xingyu; Zhang, Xiaodong; Wang, Tingan, E-mail: moonsonlife@yahoo.com; Xian, Shulin; Lu, Yunfei, E-mail: doctorlife@126.com

    2016-06-17

    Cancer cells are mainly dependent on glycolysis to generate adenosine triphosphate (ATP) and intermediates required for cell growth and proliferation. Thus, inhibition of glycolysis might be of therapeutic value in antitumor treatment. Our previously studies had found that both 3-bromopyruvate (BP) and sodium citrate (SCT) can inhibit tumor growth and proliferation in vitro and in vivo. However, the mechanism involved in the BP and SCT mediated antitumor activity is not entirely clear. In this work, it is demonstrated that BP inhibits the enzyme hexokinase (HK) activity and SCT suppresses the phosphofructokinase (PFK) activity respectively, both the two agents decrease viability, ATP generation and lactate content in the human gastric cancer cell line MGC-803. These effects are directly correlated with blockage of glycolysis. Furthermore, BP and SCT can induce the characteristic manifestations of mitochondria-regulated apoptosis, such as down-regulation of anti-apoptosis proteins Bcl-2 and Survivin, up-regulation of pro-apoptosis protein Bax, activation of caspase-3, as well as leakage of cytochrome c (Cyt-c). In summary, our results provided evidences that BP and SCT inhibit the MGC-803 cells growth and proliferation might be correlated with inhibiting glycolysis and promoting mitochondria-regulated apoptosis. -- Highlights: •Blockage of glycolysis might be a novel way to anticancer. •Both 3-bromopyruvate and sodium citrate could inhibit glycolysis and regulate mitochondrial pathway in cancer cells. •Both 3-bromopyruvate and sodium citrate would be the novel agents on treatment of gastric cancer.

  11. 3-Bromopyruvate and sodium citrate induce apoptosis in human gastric cancer cell line MGC-803 by inhibiting glycolysis and promoting mitochondria-regulated apoptosis pathway

    International Nuclear Information System (INIS)

    Guo, Xingyu; Zhang, Xiaodong; Wang, Tingan; Xian, Shulin; Lu, Yunfei

    2016-01-01

    Cancer cells are mainly dependent on glycolysis to generate adenosine triphosphate (ATP) and intermediates required for cell growth and proliferation. Thus, inhibition of glycolysis might be of therapeutic value in antitumor treatment. Our previously studies had found that both 3-bromopyruvate (BP) and sodium citrate (SCT) can inhibit tumor growth and proliferation in vitro and in vivo. However, the mechanism involved in the BP and SCT mediated antitumor activity is not entirely clear. In this work, it is demonstrated that BP inhibits the enzyme hexokinase (HK) activity and SCT suppresses the phosphofructokinase (PFK) activity respectively, both the two agents decrease viability, ATP generation and lactate content in the human gastric cancer cell line MGC-803. These effects are directly correlated with blockage of glycolysis. Furthermore, BP and SCT can induce the characteristic manifestations of mitochondria-regulated apoptosis, such as down-regulation of anti-apoptosis proteins Bcl-2 and Survivin, up-regulation of pro-apoptosis protein Bax, activation of caspase-3, as well as leakage of cytochrome c (Cyt-c). In summary, our results provided evidences that BP and SCT inhibit the MGC-803 cells growth and proliferation might be correlated with inhibiting glycolysis and promoting mitochondria-regulated apoptosis. -- Highlights: •Blockage of glycolysis might be a novel way to anticancer. •Both 3-bromopyruvate and sodium citrate could inhibit glycolysis and regulate mitochondrial pathway in cancer cells. •Both 3-bromopyruvate and sodium citrate would be the novel agents on treatment of gastric cancer.

  12. Troglitazone induced apoptosis via PPARγ activated POX-induced ROS formation in HT29 cells.

    Science.gov (United States)

    Wang, Jing; Lv, XiaoWen; Shi, JiePing; Hu, XiaoSong; DU, YuGuo

    2011-08-01

    In order to investigate the potential mechanisms in troglitazone-induced apoptosis in HT29 cells, the effects of PPARγ and POX-induced ROS were explored. [3- (4, 5)-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) assay, Annexin V and PI staining using FACS, plasmid transfection, ROS formation detected by DCFH staining, RNA interference, RT-PCR & RT-QPCR, and Western blotting analyses were employed to investigate the apoptotic effect of troglitazone and the potential role of PPARγ pathway and POX-induced ROS formation in HT29 cells. Troglitazone was found to inhibit the growth of HT29 cells by induction of apoptosis. During this process, mitochondria related pathways including ROS formation, POX expression and cytochrome c release increased, which were inhibited by pretreatment with GW9662, a specific antagonist of PPARγ. These results illustrated that POX upregulation and ROS formation in apoptosis induced by troglitazone was modulated in PPARγ-dependent pattern. Furthermore, the inhibition of ROS and apoptosis after POX siRNA used in troglitazone-treated HT29 cells indicated that POX be essential in the ROS formation and PPARγ-dependent apoptosis induced by troglitazone. The findings from this study showed that troglitazone-induced apoptosis was mediated by POX-induced ROS formation, at least partly, via PPARγ activation. Copyright © 2011 The Editorial Board of Biomedical and Environmental Sciences. Published by Elsevier B.V. All rights reserved.

  13. Kaempferol suppresses bladder cancer tumor growth by inhibiting cell proliferation and inducing apoptosis.

    Science.gov (United States)

    Dang, Qiang; Song, Wenbin; Xu, Defeng; Ma, Yanmin; Li, Feng; Zeng, Jin; Zhu, Guodong; Wang, Xinyang; Chang, Luke S; He, Dalin; Li, Lei

    2015-09-01

    The effects of the flavonoid compound, kaempferol, which is an inhibitor of cancer cell proliferation and an inducer of cell apoptosis have been shown in various cancers, including lung, pancreatic, and ovarian, but its effect has never been studied in bladder cancer. Here, we investigated the effects of kaempferol on bladder cancer using multiple in vitro cell lines and in vivo mice studies. The MTT assay results on various bladder cancer cell lines showed that kaempferol enhanced bladder cancer cell cytotoxicity. In contrast, when analyzed by the flow cytometric analysis, DNA ladder experiment, and TUNEL assay, kaempferol significantly was shown to induce apoptosis and cell cycle arrest. These in vitro results were confirmed in in vivo mice studies using subcutaneous xenografted mouse models. Consistent with the in vitro results, we found that treating mice with kaempferol significant suppression in tumor growth compared to the control group mice. Tumor tissue staining results showed decreased expressions of the growth related markers, yet increased expressions in apoptosis markers in the kaempferol treated group mice tissues compared to the control group mice. In addition, our in vitro and in vivo data showed kaempferol can also inhibit bladder cancer invasion and metastasis. Further mechanism dissection studies showed that significant down-regulation of the c-Met/p38 signaling pathway is responsible for the kaempferol mediated cell proliferation inhibition. All these findings suggest kaempferol might be an effective and novel chemotherapeutic drug to apply for the future therapeutic agent to combat bladder cancer. © 2014 Wiley Periodicals, Inc.

  14. TRPV1 inhibition attenuates IL-13 mediated asthma features in mice by reducing airway epithelial injury.

    Science.gov (United States)

    Rehman, Rakhshinda; Bhat, Younus Ahmad; Panda, Lipsa; Mabalirajan, Ulaganathan

    2013-03-01

    Even though neurogenic axis is well known in asthma pathogenesis much attention had not been given on this aspect. Recent studies have reported the importance of TRP channels, calcium-permeable ion channels and key molecules in neurogenic axis, in asthma therapeutics. The role of TRPV1 channels has been underestimated in chronic respiratory diseases as TRPV1 knockout mice of C57BL/6 strains did not attenuate the features of these diseases. However, this could be due to strain differences in the distribution of airway capsaicin receptors. Here, we show that TRPV1 inhibition attenuates IL-13 induced asthma features by reducing airway epithelial injury in BALB/c mice. We found that IL-13 increased not only the lung TRPV1 levels but also TRPV1 expression in bronchial epithelia in BALB/c rather than in C57BL/6 mice. TRPV1 knockdown attenuated airway hyperresponsiveness, airway inflammation, goblet cell metaplasia and subepithelial fibrosis induced by IL-13 in BALB/c mice. Further, TRPV1 siRNA treatment reduced not only the cytosolic calpain and mitochondrial calpain 10 activities in the lung but also bronchial epithelial apoptosis indicating that TRPV1 siRNA might have corrected the intracellular and intramitochondrial calcium overload and its consequent apoptosis. Knockdown of IL-13 in allergen induced asthmatic mice reduced TRPV1, cytochrome c, and activities of calpain and caspase 3 in lung cytosol. Thus, these findings suggest that induction of TRPV1 with IL-13 in bronchial epithelia could lead to epithelial injury in in vivo condition. Since TRPV1 expression is correlated with human asthma severity, TRPV1 inhibition could be beneficial in attenuating airway epithelial injury and asthma features. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. The role of γ-ray-induced fibroblast apoptosis in inhibiting biliary duct hypertrophic scar formation in dogs

    International Nuclear Information System (INIS)

    He Guijin; Zhang Hong; Gao Xinyi; Xu Shuhe; Gao Hong; Jiang Weiguo; Jiangtao; Dai Xianwei; Ma Kai

    2005-01-01

    Objective: To investigate the role of γ-ray-induced fibroblast apoptosis in the inhibition of biliary duct hypertrophic scar formation in dogs. Methods: γ-radiation-induced apoptotic fibroblast cells were analysed by using transmission electron microscopy and DNA from frozen biliary duct tissue was extracted with phenol chloroform. DNA ladder profile after extraction of RNA was observed, and apoptosis cells in paraffinem-bedded biliary duct tissue sections were examined used immuno-histochemical method. Dog biliary duct cross-sections were stained with hematoxylin-erosin, Masson's trichrome, and Verhoeff-van Giesen stains. Muscle formation area, lumen circumference, and stenosis degree were determined by a computer-assisted image analysis system. Results: 103 Pd radioactive stent significantly inhibited fibroblast proliferation. The features of fibroblast apoptosis (e.g, apoptic bodies, DNA ladder band) could be seen in the 103 Pd radioactive stent group. The fibroblast apoptotic rate was significantly increased in the 103 Pd radioactive stent group than in the control group (P 103 Pd radioactive stent significantly reduced biliary muscular formation. Conclusion: 103 Pd radioactive stent could have the effect of inhibiting the proliferation of scar-forming fibroblast, and thus could be used for treatment and (or) prevention of hypertrophic scar formation in biliary duct. (authors)

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

    International Nuclear Information System (INIS)

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

    2014-01-01

    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

  17. Mesenchymal Stem Cells Protect Nucleus Pulposus Cells from Compression-Induced Apoptosis by Inhibiting the Mitochondrial Pathway

    Directory of Open Access Journals (Sweden)

    Sheng Chen

    2017-01-01

    Full Text Available Objective. Excessive apoptosis of nucleus pulposus cells (NPCs induced by various stresses, including compression, contributes to the development of intervertebral disc degeneration (IVDD. Mesenchymal stem cells (MSCs can benefit the regeneration of NPCs and delay IVDD, but the underlying molecular mechanism is poorly understood. This study aimed to evaluate the antiapoptosis effects of bone marrow-derived MSC (BMSC on rat NPCs exposed to compression and investigate whether the mitochondrial pathway was involved. Methods. BMSCs and NPCs were cocultured in the compression apparatus at 1.0 MPa for 36 h. Cell viability, apoptosis, mitochondrial function, and the expression of apoptosis-related proteins were evaluated. Results. The results showed that coculturing with BMSCs increased the cell viability and reduced apoptosis of NPCs exposed to compression. Meanwhile, BMSCs could relieve the compression-induced mitochondrial damage of NPCs by decreasing reactive oxygen species level and maintaining mitochondrial membrane potential as well as mitochondrial integrity. Furthermore, coculturing with BMSCs suppressed the activated caspase-3 and activated caspase-9, decreased the expressions of cytosolic cytochrome c and Bax, and increased the expression of Bcl-2. Conclusions. Our results suggest that BMSCs can protect against compression-induced apoptosis of NPCs by inhibiting the mitochondrial pathway and thus enhance our understanding on the MSC-based therapy for IVDD.

  18. Tributyltin induces apoptotic signaling in hepatocytes through pathways involving the endoplasmic reticulum and mitochondria

    International Nuclear Information System (INIS)

    Grondin, Melanie; Marion, Michel; Denizeau, Francine; Averill-Bates, Diana A.

    2007-01-01

    Tri-n-butyltin is a widespread environmental toxicant, which accumulates in the liver. This study investigates whether tri-n-butyltin induces pro-apoptotic signaling in rat liver hepatocytes through pathways involving the endoplasmic reticulum and mitochondria. Tri-n-butyltin activated the endoplasmic reticulum pathway of apoptosis, which was demonstrated by the activation of the protease calpain, its translocation to the plasma membrane, followed by cleavage of the calpain substrates, cytoskeletal protein vinculin, and caspase-12. Caspase-12 is localized to the cytoplasmic side of the endoplasmic reticulum and is involved in apoptosis mediated by the endoplasmic reticulum. Tri-n-butyltin also caused translocation of the pro-apoptotic proteins Bax and Bad from the cytosol to mitochondria, as well as changes in mitochondrial membrane permeability, events which can activate the mitochondrial death pathway. Tri-n-butyltin induced downstream apoptotic events in rat hepatocytes at the nuclear level, detected by chromatin condensation and by confocal microscopy using acridine orange. We investigated whether the tri-n-butyltin-induced pro-apoptotic events in hepatocytes could be linked to perturbation of intracellular calcium homeostasis, using confocal microscopy. Tri-n-butyltin caused changes in intracellular calcium distribution, which were similar to those induced by thapsigargin. Calcium was released from a subcellular compartment, which is likely to be the endoplasmic reticulum, into the cytosol. Cytosolic acidification, which is known to trigger apoptosis, also occurred and involved the Cl - /HCO 3 - exchanger. Pro-apoptotic events in hepatocytes were inhibited by the calcium chelator, Bapta-AM, and by a calpain inhibitor, which suggests that changes in intracellular calcium homeostasis are involved in tri-n-butyltin-induced apoptotic signaling in rat hepatocytes

  19. Mechanisms of caffeine-induced inhibition of UVB carcinogenesis

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    Allan H Conney

    2013-06-01

    Full Text Available Sunlight-induced nonmelanoma skin cancer is the most prevalent cancer in the United States with more than 2 million cases per year. Several studies have shown an inhibitory effect of caffeine administration on UVB-induced skin cancer in mice, and these studies are paralleled by epidemiology studies that indicate an inhibitory effect of coffee drinking on nonmelanoma skin cancer in humans. Strikingly, decaffeinated coffee consumption had no such inhibitory effect.Mechanism studies indicate that caffeine has a sunscreen effect that inhibits UVB-induced formation of thymine dimers and sunburn lesions in the epidermis of mice. In addition, caffeine administration has a biological effect that enhances UVB-induced apoptosis thereby enhancing the elimination of damaged precancerous cells, and caffeine administration also enhances apoptosis in tumors. Caffeine administration enhances UVB-induced apoptosis by p53-dependent and p53-independent mechanisms. Exploration of the p53-independent effect indicated that caffeine administration enhanced UVB-induced apoptosis by inhibiting the UVB-induced increase in ATR-mediated formation of phospho-Chk1 (Ser345 and abolishing the UVB-induced decrease in cyclin B1 which resulted in caffeine-induced premature and lethal mitosis in mouse skin. In studies with cultured primary human keratinocytes, inhibition of ATR with siRNA against ATR inhibited Chk1 phosphorylation and enhanced UVB-induced apoptosis. Transgenic mice with decreased epidermal ATR function that were irradiated chronically with UVB had 69% fewer tumors at the end of the study compared with irradiated littermate controls with normal ATR function. These results, which indicate that genetic inhibition of ATR (like pharmacologic inhibition of ATR via caffeine inhibits UVB-induced carcinogenesis and supports the concept that ATR-mediated phosphorylation of Chk1 is an important target for caffeine’s inhibitory effect on UVB-induced carcinogenesis.

  20. Ikaros is degraded by proteasome-dependent mechanism in the early phase of apoptosis induction

    International Nuclear Information System (INIS)

    He, Li-Cai; Xu, Han-Zhang; Gu, Zhi-Min; Liu, Chuan-Xu; Chen, Guo-Qiang; Wang, Yue-Fei; Wen, Dong-Hua; Wu, Ying-Li

    2011-01-01

    Research highlights: → Chemotherapeutic drugs or UV treatment reduces Ikaros prior to caspase-3 activation. → Etoposide treatment does not alter the mRNA but shortens the half-life of Ikaros. → MG132 or epoxomicin but not calpeptin inhibits etoposide-induced Ikaros degradation. → Overexpression of Ikaros accelerates etoposide-induced apoptosis in NB4 cells. -- Abstract: Ikaros is an important transcription factor involved in the development and differentiation of hematopoietic cells. In this work, we found that chemotherapeutic drugs or ultraviolet radiation (UV) treatment could reduce the expression of full-length Ikaros (IK1) protein in less than 3 h in leukemic NB4, Kasumi-1 and Jurkat cells, prior to the activation of caspase-3. Etoposide treatment could not alter the mRNA level of IK1 but it could shorten the half-life of IK1. Co-treatment with the proteasome inhibitor MG132 or epoxomicin but not calpain inhibitor calpeptin inhibited etoposide-induced Ikaros downregulation. Overexpression of IK1 could accelerate etoposide-induced apoptosis in NB4 cells, as evidenced by the increase of Annexin V positive cells and the more early activation of caspase 3. To our knowledge, this is the first report to show that upon chemotherapy drugs or UV treatment, IK1 could be degraded via the proteasome system in the early phase of apoptosis induction. These data might shed new insight on the role of IK1 in apoptosis and the post-translational regulation of IK1.

  1. LPS inhibits caspase 3-dependent apoptosis in RAW264.7 macrophages induced by the AMPK activator AICAR

    International Nuclear Information System (INIS)

    Russe, Otto Quintus; Möser, Christine V.; Kynast, Katharina L.; King, Tanya S.; Olbrich, Katrin; Grösch, Sabine; Geisslinger, Gerd; Niederberger, Ellen

    2014-01-01

    Highlights: • AMPK-activation induces caspase 3-dependent apoptosis in macrophages. • Apoptosis is associated with decreased mTOR and increased p21 levels. • All effects can be significantly inhibited by the TLR4 agonist lipopolysaccharide. - Abstract: AMP-activated kinase is a cellular energy sensor which is activated in stages of increased ATP consumption. Its activation has been associated with a number of beneficial effects such as decreasing inflammatory processes and the disease progress of diabetes and obesity, respectively. Furthermore, AMPK activation has been linked with induction of cell cycle arrest and apoptosis in cancer and vascular cells, indicating that it might have a therapeutic impact for the treatment of cancer and atherosclerosis. However, the impact of AMPK on the proliferation of macrophages, which also play a key role in the formation of atherosclerotic plaques and in inflammatory processes, has not been focused so far. We have assessed the influence of AICAR- and metformin-induced AMPK activation on cell viability of macrophages with and without inflammatory stimulation, respectively. In cells without inflammatory stimulation, we found a strong induction of caspase 3-dependent apoptosis associated with decreased mTOR levels and increased expression of p21. Interestingly, these effects could be inhibited by co-stimulation with bacterial lipopolysaccharide (LPS) but not by other proinflammatory cytokines suggesting that AICAR induces apoptosis via AMPK in a TLR4-pathway dependent manner. In conclusion, our results revealed that AMPK activation is not only associated with positive effects but might also contribute to risk factors by disturbing important features of macrophages. The fact that LPS is able to restore AMPK-associated apoptosis might indicate an important role of TLR4 agonists in preventing unfavorable cell death of immune cells

  2. LPS inhibits caspase 3-dependent apoptosis in RAW264.7 macrophages induced by the AMPK activator AICAR

    Energy Technology Data Exchange (ETDEWEB)

    Russe, Otto Quintus, E-mail: quintus@russe.eu; Möser, Christine V., E-mail: chmoeser@hotmail.com; Kynast, Katharina L., E-mail: katharina.kynast@googlemail.com; King, Tanya S., E-mail: tanya.sarah.king@googlemail.com; Olbrich, Katrin, E-mail: Katrin.olbrich@gmx.net; Grösch, Sabine, E-mail: groesch@em.uni-frankfurt.de; Geisslinger, Gerd, E-mail: geisslinger@em.uni-frankfurt.de; Niederberger, Ellen, E-mail: e.niederberger@em.uni-frankfurt.de

    2014-05-09

    Highlights: • AMPK-activation induces caspase 3-dependent apoptosis in macrophages. • Apoptosis is associated with decreased mTOR and increased p21 levels. • All effects can be significantly inhibited by the TLR4 agonist lipopolysaccharide. - Abstract: AMP-activated kinase is a cellular energy sensor which is activated in stages of increased ATP consumption. Its activation has been associated with a number of beneficial effects such as decreasing inflammatory processes and the disease progress of diabetes and obesity, respectively. Furthermore, AMPK activation has been linked with induction of cell cycle arrest and apoptosis in cancer and vascular cells, indicating that it might have a therapeutic impact for the treatment of cancer and atherosclerosis. However, the impact of AMPK on the proliferation of macrophages, which also play a key role in the formation of atherosclerotic plaques and in inflammatory processes, has not been focused so far. We have assessed the influence of AICAR- and metformin-induced AMPK activation on cell viability of macrophages with and without inflammatory stimulation, respectively. In cells without inflammatory stimulation, we found a strong induction of caspase 3-dependent apoptosis associated with decreased mTOR levels and increased expression of p21. Interestingly, these effects could be inhibited by co-stimulation with bacterial lipopolysaccharide (LPS) but not by other proinflammatory cytokines suggesting that AICAR induces apoptosis via AMPK in a TLR4-pathway dependent manner. In conclusion, our results revealed that AMPK activation is not only associated with positive effects but might also contribute to risk factors by disturbing important features of macrophages. The fact that LPS is able to restore AMPK-associated apoptosis might indicate an important role of TLR4 agonists in preventing unfavorable cell death of immune cells.

  3. Cordycepin Induces Apoptosis and Inhibits Proliferation of Human Lung Cancer Cell Line H1975 via Inhibiting the Phosphorylation of EGFR

    Directory of Open Access Journals (Sweden)

    Zheng Wang

    2016-09-01

    Full Text Available Cordycepin is an active component of the traditional Chinese medicine Cordyceps sinensis and Cordyceps militaris with notable anticancer activity. Though the prominent inhibitory activity was reported in different kinds of cancer cell lines, the concrete mechanisms remain elusive. It was reported that cordycepin could be converted into tri-phosphates in vivo to confuse a number of enzymes and interfere the normal cell function. For the inhibitory mechanism of EGFR inhibitors and the structure similarity of ATP and tri-phosphated cordycepin, human lung cancer cell line H1975 was employed to investigate the inhibitory effect of cordycepin. The results showed that cordycepin could inhibit cell proliferation and induce apoptosis in a dose-dependent manner. Cell cycle analysis revealed that H1975 cells could be arrested at the G0/G1 phase after cordycepin treatment. The expression levels of apoptosis-related protein Caspase-3 and Bcl-2 and phosphorylated expression levels of EGFR, AKT and ERK1/2 were all decreased compared with the control group stimulated with EGF. However, the protein expression levels of proapoptotic protein Bax and cleaved caspase-3 were increased. These results implied that cordycepin could inhibit cell proliferation and induce apoptosis via the EGFR signaling pathway. Our results indicated that there was potential to seek a novel EGFR inhibitor from cordycepin and its chemical derivatives.

  4. [Gefitineb inhibits the growth and induces the apoptosis of mouse I-10 Leydig testicular cancer cells in vitro].

    Science.gov (United States)

    Ji, Jie; Tong, Xu-hui; Zhang, Xin-yu; Gao, Qin; Li, Bei-bei; Wu, Xiao-xiang

    2015-09-01

    To observe the inhibitory effect of gefitineb on the proliferation and its inducing effect on the apoptosis of mouse I-10 Leydig testicular cancer cells in vitro. We treated I-10 Leydig testicular cancer cells of mice with gefitineb at 0, 1.25, 2.5, 5, 10, 20, and 40 µmol/L. Then we determined the inhibitory effect of gefitineb on the growth of the cells by MTT, detected their early and late apoptosis by Annexin V-FITC/propidium iodide double staining and Hoechst 33258 nuclear staining, respectively, and observed the expressions of apoptosis-related proteins Bcl-2, Bax and caspase 3/9 by Western blot. Compared with the blank control group, gefitineb significantly inhibited the proliferation of the I-10 cells at 10 and 20 µmol/L (P testicular cancer cells of mice and induce their apoptosis via the mitochondria-mediated apoptosis signaling pathway.

  5. Compound 13, an α1-selective small molecule activator of AMPK, inhibits Helicobacter pylori-induced oxidative stresses and gastric epithelial cell apoptosis

    International Nuclear Information System (INIS)

    Zhao, Hangyong; Zhu, Huanghuang; Lin, Zhou; Lin, Gang; Lv, Guoqiang

    2015-01-01

    Half of the world's population experiences Helicobacter pylori (H. pylori) infection, which is a main cause of gastritis, duodenal and gastric ulcer, and gastric cancers. In the current study, we investigated the potential role of compound 13 (C13), a novel α1-selective small molecule activator of AMP-activated protein kinase (AMPK), against H. pylori-induced cytotoxicity in cultured gastric epithelial cells (GECs). We found that C13 induced significant AMPK activation, evidenced by phosphorylation of AMPKα1 and ACC (acetyl-CoA carboxylase), in both primary and transformed GECs. Treatment of C13 inhibited H. pylori-induced GEC apoptosis. AMPK activation was required for C13-mediated GEC protection. Inhibition of AMPK kinase activity by the AMPK inhibitor Compound C, or silencing AMPKα1 expression by targeted-shRNAs, alleviated C13-induced GEC protective activities against H. pylori. Significantly, C13 inhibited H. pylori-induced reactive oxygen species (ROS) production in GECs. C13 induced AMPK-dependent expression of anti-oxidant gene heme oxygenase (HO-1) in GECs. Zinc protoporphyrin (ZnPP) and tin protoporphyrin (SnPP), two HO-1 inhibitors, not only suppressed C13-mediated ROS scavenging activity, but also alleviated its activity in GECs against H. pylori. Together, these results indicate that C13 inhibits H. pylori-induced ROS production and GEC apoptosis through activating AMPK–HO–1 signaling. - Highlights: • We synthesized compound 13 (C13), a α1-selective small molecule AMPK activator. • C13-induced AMPK activation requires α1 subunit in gastric epithelial cells (GECs). • C13 enhances Helicobacter pylori-induced pro-survival AMPK activation to inhibit GEC apoptosis. • C13 inhibits H. pylori-induced reactive oxygen species (ROS) production in GECs. • AMPK-heme oxygenase (HO-1) activation is required for C13-mediated anti-oxidant activity

  6. Compound 13, an α1-selective small molecule activator of AMPK, inhibits Helicobacter pylori-induced oxidative stresses and gastric epithelial cell apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Hangyong; Zhu, Huanghuang; Lin, Zhou; Lin, Gang; Lv, Guoqiang, E-mail: lvguoqiangwuxivip@163.com

    2015-08-07

    Half of the world's population experiences Helicobacter pylori (H. pylori) infection, which is a main cause of gastritis, duodenal and gastric ulcer, and gastric cancers. In the current study, we investigated the potential role of compound 13 (C13), a novel α1-selective small molecule activator of AMP-activated protein kinase (AMPK), against H. pylori-induced cytotoxicity in cultured gastric epithelial cells (GECs). We found that C13 induced significant AMPK activation, evidenced by phosphorylation of AMPKα1 and ACC (acetyl-CoA carboxylase), in both primary and transformed GECs. Treatment of C13 inhibited H. pylori-induced GEC apoptosis. AMPK activation was required for C13-mediated GEC protection. Inhibition of AMPK kinase activity by the AMPK inhibitor Compound C, or silencing AMPKα1 expression by targeted-shRNAs, alleviated C13-induced GEC protective activities against H. pylori. Significantly, C13 inhibited H. pylori-induced reactive oxygen species (ROS) production in GECs. C13 induced AMPK-dependent expression of anti-oxidant gene heme oxygenase (HO-1) in GECs. Zinc protoporphyrin (ZnPP) and tin protoporphyrin (SnPP), two HO-1 inhibitors, not only suppressed C13-mediated ROS scavenging activity, but also alleviated its activity in GECs against H. pylori. Together, these results indicate that C13 inhibits H. pylori-induced ROS production and GEC apoptosis through activating AMPK–HO–1 signaling. - Highlights: • We synthesized compound 13 (C13), a α1-selective small molecule AMPK activator. • C13-induced AMPK activation requires α1 subunit in gastric epithelial cells (GECs). • C13 enhances Helicobacter pylori-induced pro-survival AMPK activation to inhibit GEC apoptosis. • C13 inhibits H. pylori-induced reactive oxygen species (ROS) production in GECs. • AMPK-heme oxygenase (HO-1) activation is required for C13-mediated anti-oxidant activity.

  7. [Roles of KLF5 in inhibition TNFα-induced SK-BR-3 breast cancer cell apoptosis].

    Science.gov (United States)

    Shi, Jianhong; Liu, Caiyun; Zhang, Anyi; Cui, Naipeng; Wang, Bing; Chen, Baoping; Ma, Zhenfeng

    2014-07-08

    To explore the expression levels and roles of Krüpple-like factor 5 (KLF5) in tumor necrosis factor α (TNFα)-induced SK-BR-3 breast cancer cells. SK-BR-3 breast cancer cells were stimulated by TNFα at different concentrations (0, 1, 5, 10, 20 µg/L) for specified durations (0, 6, 12, 24, 36 h). Western blot was performed to detect KLF5 protein levels. Then Western blot and quantitative real-time PCR (qRT-PCR) were used to detect the expression levels of apoptosis genes. Flow cytometry and qRT-PCR were used to observe the effects of exogenous KLF5 on TNFα-induced apoptosis of SK-BR-3 breast cancer cell. KLF5 expression levels significantly decreased in TNFα-stimulated SK-BR-3 breast cancer cells in a concentration- and time-dependent manner. Quantitative RT-PCR results showed that TNFα up-regulate apoptosis gene caspase 3, caspase 9 and bax expression levels and down-regulate bcl-1 level in SK-BR-3 cells. Adenovirus expression vectors of pAd-GFP and pAd-GFP-KLF5 were constructed and used to infect SK-BR-3 breast cancer cells. Over-expression of GFP-KLF5 inhibited apoptosis in TNFα-stimulated SK-BR-3 breast cancer cells. TNFα reduces KLF5 expression in SK-BR-3 breast cancer cells and KLF5 participates in TNFα-induced SK-BR-3 cell apoptosis.

  8. Solena amplexicaulis induces cell cycle arrest, apoptosis and inhibits angiogenesis in hepatocarcinoma cells and HUVECs.

    Science.gov (United States)

    Ren, Jie; Xu, Yuan Yuan; Jiang, He Fei; Yang, Meng; Huang, Qian Hui; Yang, Jie; Hu, Kun; Wei, Kun

    2014-01-01

    Solena amplexicaulis (Lam.) Gandhi (SA) has been used as a traditional medicine for the treatment of dysentery, multiple abscess, gastralgia, urethritis, and eczema in the minority area of China. This study was aimed to examine the cell proliferation inhibitory activity of the SA extract (SACE) and its mechanism of action in human hepatoma cell line (HepG2) and evaluate its anti-angiogenesis activity in human umbilical vein endothelial cell line (HUVEC). SACE could inhibit the growth of HepG2 cells in a dose- and time-dependent manner. FCM analysis showed that SACE could induce G2/M phase arrest, cell apoptosis, the mitochondrial membrane potential loss (ΔΨm) and increase the production of intracellular ROS of HepG2 cells. After treatment with SACE, topical morphological changes of apoptotic body formation, obvious increase of apoptosis-related protein expressions, such as Bax, cytochrome c, caspase-3, PARP-1, and decrease of Bcl-2, procaspase-9 protein expressions were observed at the same time. Moreover, SACE caused the significant inhibition of endothelial cell migration and tube formation in HUVEC cells. The results suggested that SACE could act as an angiogenesis inhibitor and induce cell apoptosis via a caspase-dependent mitochondrial pathway. Therefore, SACE could be a potent candidate for the prevention and treatment of liver cancer.

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

    Science.gov (United States)

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

    2015-01-01

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

  10. Polydatin inhibits cell proliferation and induces apoptosis in laryngeal cancer and HeLa cells via suppression of the PDGF/AKT signaling pathway.

    Science.gov (United States)

    Li, Haixia; Shi, Baoyuan; Li, Yanyun; Yin, Fengfang

    2017-07-01

    Polydatin (PD), a stilbene compound extracted from Polygonum cuspidatum, is suggested to possess anti-cancer activities, including inhibition of cell proliferation, cell cycle arrest, and induction of apoptosis. The platelet-derived growth factor (PDGF)/AKT signaling pathway plays complex roles in tumor suppression. However, the effect of PD on the PDGF/AKT signaling pathway in laryngeal cancer and HeLa cells has not been explored. MTT assay and flow cytometry showed that PD inhibited cell proliferation and induced apoptosis in Hep-2 and AMC-HN-8 cells. Western blot analysis indicated that PD inhibited the expression levels of PDGF-B and phosphorylated AKT (p-AKT) in both cells. Treatment of PDGF-B siRNA or PDGFR inhibitor found that after the PDGF signaling was inactivated, p-AKT expression was significantly decreased in Hep-2 cells. Tumor xenograft experiment in nude mice indicated PD significantly inhibited the growth of Hep-2 cells in vivo. In conclusion, PD inhibited cell proliferation and induced apoptosis in laryngeal cancer and HeLa cells via inactivation of the PDGF/AKT signaling pathway. © 2017 Wiley Periodicals, Inc.

  11. SNJ-1945, a calpain inhibitor, protects SH-SY5Y cells against MPP+ and rotenone

    Science.gov (United States)

    Knaryan, Varduhi H.; Samantaray, Supriti; Sookyoung, Park; Azuma, Mitsuyoshi; Inoue, Jun; Banik, Naren L.

    2014-01-01

    Complex pathophysiology of Parkinson’s disease (PD) involves multiple CNS cell types. Degeneration in spinal cord neurons alongside brain has been shown to be involved in PD and evidenced in experimental parkinsonism. However, the mechanisms of these degenerative pathways are not well understood. In order to unravel these mechanisms SH-SY5Y neuroblastoma cells were differentiated into dopaminergic and cholinergic phenotypes respectively and used as cell culture model following exposure to two parkinsonian neurotoxicants MPP+ and rotenone. SNJ-1945, a cell-permeable calpain inhibitor was tested for its neuroprotective efficacy. MPP+ and rotenone dose-dependently elevated the levels of intracellular free Ca2+ and induced a concomitant rise in the levels of active calpain. SNJ-1945 pre-treatment significantly protected cell viability and preserved cellular morphology following MPP+ and rotenone exposure. The neurotoxicants elevated the levels of reactive oxygen species (ROS) more profoundly in SH-SY5Y cells differentiated into dopaminergic phenotype, and this effect could be attenuated with SNJ-1945 pre-treatment. In contrast, significant levels of inflammatory mediators (cyclooxygenase-2, Cox-2 and cleaved p10 fragment of caspase-1) were upregulated in the cholinergic phenotype, which could be dose-dependently attenuated by the calpain inhibitor. Overall, SNJ-1945 was efficacious against MPP+ or rotenone-induced ROS generation, inflammatory mediators, and proteolysis. A post-treatment regimen of SNJ-1945 was also examined in cells and partial protection was attained with calpain inhibitor administration 1–3 h after exposure to MPP+ or rotenone. Taken together these results indicate that calpain inhibition is a valid target for protection against parkinsonian neurotoxicants, and SNJ-1945 is an efficacious calpain inhibitor in this context. PMID:24341912

  12. NF-κB inhibition is involved in tobacco smoke-induced apoptosis in the lungs of rats

    International Nuclear Information System (INIS)

    Zhong Caiyun; Zhou Yamei; Pinkerton, Kent E.

    2008-01-01

    Apoptosis is a vital mechanism for the regulation of cell turnover and plays a critical role in tissue homeostasis and development of many disease processes. Previous studies have demonstrated the apoptotic effect of tobacco smoke; however, the molecular mechanisms by which tobacco smoke triggers apoptosis remain unclear. In the present study we investigated the effects of tobacco smoke on the induction of apoptosis in the lungs of rats and modulation of nuclear factor-kappa B (NF-κB) in this process. Exposure of rats to 80 mg/m 3 tobacco smoke significantly induced apoptosis in the lungs. Tobacco smoke resulted in inhibition of NF-κB activity, noted by suppression of inhibitor of κB (IκB) kinase (IKK), accumulation of IκBα, decrease of NF-κB DNA binding activity, and downregulation of NF-κB-dependent anti-apoptotic proteins, including Bcl-2, Bcl-xl, and inhibitors of apoptosis. Initiator caspases for the death receptor pathway (caspase 8) and the mitochondrial pathway (caspase 9) as well as effector caspase 3 were activated following tobacco smoke exposure. Tobacco smoke exposure did not alter the levels of p53 and Bax proteins. These findings suggest the role of NF-κB pathway in tobacco smoke-induced apoptosis

  13. Andrographolide induces apoptotic and non-apoptotic death and enhances tumor necrosis factor-related apoptosis-inducing ligand-mediated apoptosis in gastric cancer cells.

    Science.gov (United States)

    Lim, Sung-Chul; Jeon, Ho Jong; Kee, Keun Hong; Lee, Mi Ja; Hong, Ran; Han, Song Iy

    2017-05-01

    Andrographolide, a natural compound isolated from Andrographis paniculata , has been reported to possess antitumor activity. In the present study, the effect of andrographolide in human gastric cancer (GC) cells was investigated. Andrographolide induced cell death with apoptotic and non-apoptotic features. At a low concentration, andrographolide potentiated apoptosis and reduction of clonogenicity triggered by recombinant human tumor necrosis factor-related apoptosis-inducing ligand (rhTRAIL). Exposure of GC cells to andrographolide altered the expression level of several growth-inhibiting and apoptosis-regulating proteins, including death receptors. It was demonstrated that activity of the TRAIL-R2 (DR5) pathway was critical in the development of andrographolide-mediated rhTRAIL sensitization, since its inhibition significantly reduced the extent of apoptosis induced by the combination of rhTRAIL and andrographolide. In addition, andrographolide increased reactive oxygen species (ROS) generation in a dose-dependent manner. N-acetyl cysteine prevented andrographolide-mediated DR5 induction and the apoptotic effect induced by the combination of rhTRAIL and andrographolide. Collectively, the present study demonstrated that andrographolide enhances TRAIL-induced apoptosis through induction of DR5 expression. This effect appears to involve ROS generation in GCs.

  14. Inhibition of PDGFR by CP-673451 induces apoptosis and increases cisplatin cytotoxicity in NSCLC cells via inhibiting the Nrf2-mediated defense mechanism.

    Science.gov (United States)

    Yang, Yang; Deng, Yanchao; Chen, Xiangcui; Zhang, Jiahao; Chen, Yueming; Li, Huachao; Wu, Qipeng; Yang, Zhicheng; Zhang, Luyong; Liu, Bing

    2018-05-29

    Platelet-derived growth factor receptors (PDGFRs) are abundantly expressed by stromal cells in the non-small cell lung cancer (NSCLC) microenvironment, and in a subset of cancer cells, usually with their overexpression and/or activating mutation. However, the effect of PDGFR inhibition on lung cancer cells themselves has been largely neglected. In this study, we investigated the anticancer activity of CP-673451, a potent and selective inhibitor of PDGFRβ, on NSCLC cell lines (A549 and H358) and the potential mechanism. The results showed that inhibition of PDGFRβ by CP-673451 induced a significant increase in cell apoptosis, accompanied by ROS accumulation. However, CP-673451 exerted less cytotoxicity in normal lung epithelial cell line BEAS-2B cells determined by MTT and apoptosis assay. Elimination of ROS by NAC reversed the CP-673451-induced apoptosis in NSCLC cells. Furthermore, CP-673451 down-regulated the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) probably through inhibition of PI3K/Akt pathway. Rescue of Nrf2 activity counteracted the effects of CP-673451 on cell apoptosis and ROS accumulation. Silencing PDGFRβ expression by PDGFRβ siRNA exerted similar effects with CP-673451 in A549 cells, and when PDGFRβ was knockdowned by PDGFRβ siRNA, CP-673451 produced no additional effects on cell viability, ROS and GSH production, Nrf2 expression as well as PI3K/Akt pathway activity. Specifically, Nrf2 plays an indispensable role in NSCLC cell sensitivity to platinum-based treatments and we found that combination of CP-673451 and cisplatin produced a synergistic anticancer effect and substantial ROS production in vitro. Therefore, these results clearly demonstrate the effectiveness of inhibition of PDGFRβ against NSCLC cells and strongly suggest that CP-673451 may be a promising adjuvant chemotherapeutic drug. Copyright © 2018 Elsevier B.V. All rights reserved.

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

    International Nuclear Information System (INIS)

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

    2008-01-01

    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 XS ; 400 μg/ml), UV-irradiated virus (CIV UV ; 10 μg/ml) and CVPE (CIV protein extract; 10 μg/ml) induced apoptosis in 60% of treated Choristoneura fumiferana (IPRI-CF-124T) cells. Normal doses of infectious CIV (10 μg/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 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 UV particles bound to polysterene beads failed to induce apoptosis. Endocytosis inhibitors (bafilomycin or ammonium chloride) negated apoptosis induction by CIV UV , CIV XS or CVPE indicating that entry through this mode is required. Given the weak apoptotic response to infectious CIV, we postulated that viral gene expression inhibited apoptosis. CIV infection of cells pretreated with cycloheximide induced apoptosis in 69% of the cells compared to 10% in normal infections. Furthermore, blocking viral DNA replication with aphidicolin or phosphonoacetic acid suppressed apoptosis and Cf-caspase-i activity, indicating that early viral expression is necessary for inhibition of apoptosis, and de novo synthesis of viral proteins is not required for induction. We show for the first time that, in a member of the family Iridoviridae, apoptosis: (i) requires entry and

  16. Inhibition of miR-155 Protects Against LPS-induced Cardiac Dysfunction and Apoptosis in Mice

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    Hui Wang

    2016-01-01

    Full Text Available Sepsis-induced myocardial dysfunction represents a major cause of death in intensive care units. Dysregulated microRNAs (miR-155 has been implicated in multiple cardiovascular diseases and miR-155 can be induced by lipopolysaccharide (LPS. However, the role of miR-155 in LPS-induced cardiac dysfunction is unclear. Septic cardiac dysfunction in mice was induced by intraperitoneal injection of LPS (5 mg/kg and miR-155 was found to be significantly increased in heart challenged with LPS. Pharmacological inhibition of miR-155 using antagomiR improved cardiac function and suppressed cardiac apoptosis induced by LPS in mice as determined by echocardiography, terminal deoxynucleotidyl transferase nick-end labeling (TUNEL assay, and Western blot for Bax and Bcl-2, while overexpression of miR-155 using agomiR had inverse effects. Pea15a was identified as a target gene of miR-155, mediating its effects in controlling apoptosis of cardiomyocytes as evidenced by luciferase reporter assays, quantitative real time-polymerase chain reaction, Western blot, and TUNEL staining. Noteworthy, miR-155 was also found to be upregulated in the plasma of patients with septic cardiac dysfunction compared to sepsis patients without cardiac dysfunction, indicating a potential clinical relevance of miR-155. The receiver-operator characteristic curve indicated that plasma miR-155 might be a biomarker for sepsis patients developing cardiac dysfunction. Therefore, inhibition of miR-155 represents a novel therapy for septic myocardial dysfunction.

  17. [Decursin reduces reactive oxygen species and inhibits cisplatin-induced apoptosis in rat renal tubular epithelial cells].

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    Li, Cuiqiong; Li, Jianchun; Fan, Junming; Meng, Lifeng; Cao, Ling

    2017-10-01

    Objective To study the mechanism underlying the inhibitory effect of decursin on the apoptosis of rat renal tubular epithelial cells NRK-52E induced by cisplatin. Methods First, CCK-8 assay was used to detect the effects of 0, 10, 20, 40, 80, 100, 150, 200 μmol/L decursin and 0, 5, 10, 20, 30, 40, 50 μg/mL cispatin treatment for 24 hours on cell proliferation in NRK-52E cells via determining the half inhibitory concentration (IC 50 ). Then, NRK-52E cells were stimulated with 20 μg/mL cisplatin combined with 10, 50, 100 μmol/L decursin, and cell activity was detected by CCK-8 assay. The cells were divided into normal control group, 20 μg/mL cisplatin stimulation group, and 10, 50, 100 μmol/L decursin treated groups. Cell morphological changes was observed under inverted microscope, morphological changes of nucleus was detected by DAPI staining, cell apoptosis was detected by flow cytometry, the level of intracellular ROS was detected by DCFH-DA staining, and the apoptosis marker proteins cleaved-caspase-3 and cleaved-PARP were examined by Western blot analysis. Results Compared with the normal control group, cisplatin significantly inhibited the activity of the cells, and IC 50 was about 20 μg/mL; compared with the model group, in the decursin pretreatment groups, the level of intracellular ROS decreased remarkably, the expressions of cleaved-casspase-3 and cleaved-PARP proteins were reduced, and cell apoptosis was depressed. Conclusion Decursin can decrease the intracellular ROS level and inhibit the apoptosis of NRK-52E cells induced by cisplatin.

  18. Troglitazone inhibits cell growth and induces apoptosis of B-cell acute lymphoblastic leukemia cells with t(14;18).

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    Takenokuchi, M; Saigo, K; Nakamachi, Y; Kawano, S; Hashimoto, M; Fujioka, T; Koizumi, T; Tatsumi, E; Kumagai, S

    2006-01-01

    Peroxisome proliferator-activated receptor-gamma (PPARgamma), a member of the nuclear receptor superfamily, has been detected in several human leukemia cells. Recent studies reported that PPARgamma ligands inhibit cell proliferation and induce apoptosis in both normal and malignant B-lineage cells. We investigated the expression of PPARgamma and the effects of PPARgamma ligands on UTree-O2, Bay91 and 380, three B-cell acute lymphoblastic leukemia (B-ALL) cell lines with t(14;18), which show a poor prognosis, accompanying c-myc abnormality. Western blot analysis identified expression of PPARgamma protein and real-time PCR that of PPARgamma mRNA on the three cell lines. Troglitazone (TGZ), a synthetic PPARgamma ligand, inhibited cell growth in these cell lines in a dose-dependent manner, which was associated with G(1) cell cycle arrest and apoptosis. We also found this effect PPARgamma independent since PPARgamma antagonists failed to reverse this effect. We assessed the expression of c-myc, an apoptosis-regulatory gene, since c-myc abnormality was detected in most B-ALL cells with t(14;18). TGZ was found to dose-dependently downregulate the expression of c-myc mRNA and c-myc protein in the three cell lines. These results suggest that TGZ inhibits cell growth via induction of G(1) cell cycle arrest and apoptosis in these cell lines and that TGZ-induced apoptosis, at least in part, may be related to the downregulation of c-myc expression. Moreover, the downregulation of c-myc expression by TGZ may depend on a PPARgamma-independent mechanism. Further studies indicate that PPARgamma ligands may serve as a therapeutic agent in B-ALL with t(14;18).

  19. Ginsenoside Rb1 Attenuates Oxygen-Glucose Deprivation-Induced Apoptosis in SH-SY5Y Cells via Protection of Mitochondria and Inhibition of AIF and Cytochrome c Release

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    Pengfei Ge

    2013-10-01

    Full Text Available To investigate the role of mitochondria in the protective effects of ginsenoside Rb1 on cellular apoptosis caused by oxygen-glucose deprivation, in this study, MTT assay, TUNEL staining, flow cytometry, immunocytochemistry and western blotting were used to examine the cellular viability, apoptosis, ROS level, mitochondrial membrane potential, and the distribution of apoptosis inducing factor, cytochrome c, Bax and Bcl-2 in nucleus, mitochondria and cytoplasm. We found that pretreatment with GRb1 improved the cellular viability damaged by OGD. Moreover, GRb1 inhibited apoptosis in SH-SY5Y cells induced by OGD. Further studies showed that the elevation of cellular reactive oxygen species levels and the reduction of mitochondrial membrane potential caused by OGD were both counteracted by GRb1. Additionally, GRb1 not only suppressed the translocation of apoptosis inducing factor into nucleus and cytochrome c into cytoplasm, but also inhibited the increase of Bax within mitochondria and alleviated the decrease of mitochondrial Bcl-2. Our study indicates that the protection of GRb1 on OGD-induced apoptosis in SH-SY5Y cells is associated with its protection on mitochondrial function and inhibition of release of AIF and cytochrome c.

  20. Inhibition of Drp1 protects against senecionine-induced mitochondria-mediated apoptosis in primary hepatocytes and in mice

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    Xiao Yang

    2017-08-01

    Full Text Available Pyrrolizidine alkaloids (PAs are a group of compounds found in various plants and some of them are widely consumed in the world as herbal medicines and food supplements. PAs are potent hepatotoxins that cause irreversible liver injury in animals and humans. However, the mechanisms by which PAs induce liver injury are not clear. In the present study, we determined the hepatotoxicity and molecular mechanisms of senecionine, one of the most common toxic PAs, in primary cultured mouse and human hepatocytes as well as in mice. We found that senecionine administration increased serum alanine aminotransferase levels in mice. H&E and TUNEL staining of liver tissues revealed increased hemorrhage and hepatocyte apoptosis in liver zone 2 areas. Mechanistically, senecionine induced loss of mitochondrial membrane potential, release of mitochondrial cytochrome c as well as mitochondrial JNK translocation and activation prior to the increased DNA fragmentation and caspase-3 activation in primary cultured mouse and human hepatocytes. SP600125, a specific JNK inhibitor, and ZVAD-fmk, a general caspase inhibitor, alleviated senecionine-induced apoptosis in primary hepatocytes. Interestingly, senecionine also caused marked mitochondria fragmentation in hepatocytes. Pharmacological inhibition of dynamin-related protein1 (Drp1, a protein that is critical to regulate mitochondrial fission, blocked senecionine-induced mitochondrial fragmentation and mitochondrial release of cytochrome c and apoptosis. More importantly, hepatocyte-specific Drp1 knockout mice were resistant to senecionine-induced liver injury due to decreased mitochondrial damage and apoptosis. In conclusion, our results uncovered a novel mechanism of Drp1-mediated mitochondrial fragmentation in senecionine-induced liver injury. Targeting Drp1-mediated mitochondrial fragmentation and apoptosis may be a potential avenue to prevent and treat hepatotoxicity induced by PAs. Keywords: Senecionine, Drp1

  1. Edaravone protects against oxygen-glucose-serum deprivation/restoration-induced apoptosis in spinal cord astrocytes by inhibiting integrated stress response

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    Bin Dai

    2017-01-01

    Full Text Available We previously found that oxygen-glucose-serum deprivation/restoration (OGSD/R induces apoptosis of spinal cord astrocytes, possibly via caspase-12 and the integrated stress response, which involves protein kinase R-like endoplasmic reticulum kinase (PERK, eukaryotic initiation factor 2-alpha (eIF2α and activating transcription factor 4 (ATF4. We hypothesized that edaravone, a low molecular weight, lipophilic free radical scavenger, would reduce OGSD/R-induced apoptosis of spinal cord astrocytes. To test this, we established primary cultures of rat astrocytes, and exposed them to 8 hours/6 hours of OGSD/R with or without edaravone (0.1, 1, 10, 100 μM treatment. We found that 100 μM of edaravone significantly suppressed astrocyte apoptosis and inhibited the release of reactive oxygen species. It also inhibited the activation of caspase-12 and caspase-3, and reduced the expression of homologous CCAAT/enhancer binding protein, phosphorylated (p-PERK, p-eIF2α, and ATF4. These results point to a new use of an established drug in the prevention of OGSD/R-mediated spinal cord astrocyte apoptosis via the integrated stress response.

  2. Ginkgo Biloba Extract Kaempferol Inhibits Cell Proliferation and Induces Apoptosis in Pancreatic Cancer Cells

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    Zhang, Yuqing; Chen, Aaron Y.; Li, Min; Chen, Changyi; Yao, Qizhi

    2010-01-01

    Background Kaempferol is one of the most important constituents in ginkgo flavonoids. Recent studies indicate kaempferol may have anti-tumor activities. The objective in this study was to determine the effect and mechanisms of kaempferol on pancreatic cancer cell proliferation and apoptosis. Materials and Methods Pancreatic cancer cell lines MIA PaCa-2 and Panc-1 were treated with Kampferol, and the inhibitory effects of kaempferol on pancreatic cancer cell proliferation were examined by direct cell counting, 3H-thymidine incorporation and MTS assay. Lactate dehydrogenase (LDH) release from cells was determined as an index of cytotoxicity. Apoptosis was analyzed by TUNEL assay. Results Upon the treatment with 70 μM kaempferol for 4 days, MIA PaCa-2 cell proliferation was significantly inhibited by 79% and 45.7% as determined by direct cell counting and MTS assay, respectively, compared with control cells (Pkaempferol significantly inhibited Panc-1 cell proliferation. Kaempferol treatment also significantly reduced 3H-thymidine incorporation in both MIA PaCa-2 and Panc-1 cells. Combination treatment of low concentrations of kaempferol and 5-fluorouracil (5-FU) showed an additive effect on the inhibition of MIA PaCa-2 cell proliferation. Furthermore, kaempferol had a significantly less cytotoxicity than 5-FU in normal human pancreatic ductal epithelial cells (P=0.029). In both MIA PaCa-2 and Panc-1 cells, apoptotic cell population was increased when treated with kaempferol in a concentration-dependent manner. Conclusions Ginkgo biloba extract kaempferol effectively inhibits pancreatic cancer cell proliferation and induces cancer cell apoptosis, which may sensitize pancreatic tumor cells to chemotherapy. Kaempferol may have clinical applications as adjuvant therapy in the treatment of pancreatic cancer. PMID:18570926

  3. Evidence that tumor necrosis factor-related apoptosis inducing ligand (TRAIL) inhibits angiogenesis by inducing vascular endothelial cell apoptosis

    International Nuclear Information System (INIS)

    Chen, Pei-Lin; Easton, Alexander S.

    2010-01-01

    Tumor necrosis factor (TNF) and its related ligands TNF-related apoptosis inducing ligand (TRAIL) and Fas ligand (FasL) play roles in the regulation of vascular responses, but their effect on the formation of new blood vessels (angiogenesis) is unclear. Therefore, we have examined the effects of these ligands on angiogenesis modeled with primary cultures of human umbilical vein endothelial cells (HUVEC). To examine angiogenesis in the context of the central nervous system, we have also modeled cerebral angiogenesis with the human brain endothelial cell line hCMEC/D3. Parameters studied were bromodeoxyuridine (BrdU) incorporation and cell number (MTT) assay (to assess endothelial proliferation), scratch assay (migration) and networks on Matrigel (tube formation). In our hands, neither TRAIL nor FasL (1, 10, and 100 ng/ml) had an effect on parameters of angiogenesis in the HUVEC model. In hCMEC/D3 cells by contrast, TRAIL inhibited all parameters (10-100 ng/ml, 24 h). This was due to apoptosis, since its action was blocked by the pan-caspase inhibitor zVADfmk (5 x 10 -5 mol/l) and TRAIL increased caspase-3 activity 1 h after application. However FasL (100 ng/ml) increased BrdU uptake without other effects. We conclude that TRAIL has different effects on in vitro angiogenesis depending on which model is used, but that FasL is generally ineffective when applied in vitro. The data suggest that TRAIL primarily influences angiogenesis by the induction of vascular endothelial apoptosis, leading to vessel regression.

  4. Methyl Sartortuoate Inhibits Colon Cancer Cell Growth by Inducing Apoptosis and G2/M-Phase Arrest.

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    Lan, Qiusheng; Li, Shoufeng; Lai, Wei; Xu, Heyang; Zhang, Yang; Zeng, Yujie; Lan, Wenjian; Chu, Zhonghua

    2015-08-17

    The potential anti-neoplastic activity of terpenoids is of continued interest. In this study, we investigate whether methyl sartortuoate, a terpenoid isolated from soft coral, induced cell cycle arrest and apoptosis in a human colon cancer cell line. Culture studies found that methyl sartortuoate inhibited colon cancer cell (LoVo and RKO) growth and caused apoptotic death in a concentration- and time-dependent manner, by activation of caspase-8, caspase-9, caspase-3, p53 and Bax, and inactivation of B-cell lymphoma 2 (Bcl-2) apoptosis regulating proteins. Methyl sartortuoate treatment led to reduced expression of cdc2 and up-regulated p21 and p53, suggesting that Methyl sartortuoate induced G2-M arrest through modulation of p53/p21/cdc2 pathways. Methyl sartortuoate also up-regulated phospho-JNK and phospho-p38 expression levels. This resulted in cell cycle arrest at the G2-M phase and apoptosis in LoVo and RKO cells. Treatment with the JNK inhibitor SP600125 and the p38 MAPK inhibitor SB203580 prevented methyl sartortuoate-induced apoptosis in LoVo cells. Moreover, methyl sartortuoate also prevented neoplasm growth in NOD-SCID nude mice inoculated with LoVo cells. Taken together, these findings suggest that methyl sartortuoate is capable of leading to activation of caspase-8, -9, -3, increasing p53 and Bax/Bcl-2 ratio apoptosis through MAPK-dependent apoptosis and results in G2-M phase arrest in LoVo and RKO cells. Thus, methyl sartortuoate may be a promising anticancer candidate.

  5. Curcumin induces apoptosis of upper aerodigestive tract cancer cells by targeting multiple pathways.

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    A R M Ruhul Amin

    Full Text Available Curcumin, a natural compound isolated from the Indian spice "Haldi" or "curry powder", has been used for centuries as a traditional remedy for many ailments. Recently, the potential use of curcumin in cancer prevention and therapy urges studies to uncover the molecular mechanisms associated with its anti-tumor effects. In the current manuscript, we investigated the mechanism of curcumin-induced apoptosis in upper aerodigestive tract cancer cell lines and showed that curcumin-induced apoptosis is mediated by the modulation of multiple pathways such as induction of p73, and inhibition of p-AKT and Bcl-2. Treatment of cells with curcumin induced both p53 and the related protein p73 in head and neck and lung cancer cell lines. Inactivation of p73 by dominant negative p73 significantly protected cells from curcumin-induced apoptosis, whereas ablation of p53 by shRNA had no effect. Curcumin treatment also strongly inhibited p-AKT and Bcl-2 and overexpression of constitutively active AKT or Bcl-2 significantly inhibited curcumin-induced apoptosis. Taken together, our findings suggest that curcumin-induced apoptosis is mediated via activating tumor suppressor p73 and inhibiting p-AKT and Bcl-2.

  6. Cantharidin Inhibits the Growth of Triple-Negative Breast Cancer Cells by Suppressing Autophagy and Inducing Apoptosis in Vitro and in Vivo

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    Hong-chang Li

    2017-10-01

    Full Text Available Background/Aims: Cantharidin, a type of terpenoid secreted by the blister beetle Mylabris phalerata (Pallas, has attracted great attention in cancer therapy because of its potential anti-cancer activities. Here, we report the effects on apoptosis and autophagy in human triple-negative breast cancer (TNBC cell lines after treatment with cantharidin and attempt to elucidate the underlying mechanisms. Methods: MDA-MB-231 and MDA-MB-468 cells were treated with cantharidin and cell proliferation was examined using CCK-8 and clone formation assays. The expression of apoptosis- and autophagy-associated proteins was detected by western blotting. Cells were infected with lentivirus carrying the Beclin-1 gene, and MDA-MB-231-beclin1 (MB231-Bec and MDA-MB-468-beclin-1(MB468-Bec cells stably expressing Beclin-1 were established. Autophagic vacuoles in cells were observed with LC3 staining using fluorescence microscopy, and apoptotic cells were detected via flow cytometry. Tumor growth was assessed by subcutaneous inoculation of TNBC cells into BALB/c nude mice. Results: Cantharidin inhibited the proliferation of MDA-MB-231 and MDA-MB-468 cells, and induced cell apoptosis. Cantharidin additionally inhibited the conversion of LC3 I to LC3 II and autophagosome formation by suppressing the expression of Beclin-1. Furthermore, overexpression of Beclin-1 in TNBC cells attenuated the cytotoxicity of cantharidin. In vivo, cantharidin inhibited the growth of MDA-MB-231 and MDA-MB-468 xenografts in nude mice by suppressing autophagy and inducing apoptosis, and Beclin-1 overexpression in TNBC cells reduced the efficacy of cantharidin. Conclusions: Cantharidin inhibits autophagy by suppressing Beclin-1 expression and inducing apoptosis of TNBC cells in vitro and in vivo, thereby representing a potential strategy for the treatment of TNBC.

  7. Inhibition of H3K9 methyltransferase G9a induces autophagy and apoptosis in oral squamous cell carcinoma

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    Ren, Aishu; Qiu, Yu [Chongqing Key Laboratory for Oral Diseases and Biomedical Sciences, Chongqing Medical University, Chongqing, 401147 (China); Affiliated Hospital of Stomatology, Chongqing Medical University, Chongqing, 401147 (China); Cui, Hongjuan [State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716 (China); Fu, Gang, E-mail: fg.ras@hotmail.com [Chongqing Key Laboratory for Oral Diseases and Biomedical Sciences, Chongqing Medical University, Chongqing, 401147 (China); Affiliated Hospital of Stomatology, Chongqing Medical University, Chongqing, 401147 (China)

    2015-03-27

    Objective: To explore whether inhibition of H3K9 Methyltransferase G9a could exert an antitumoral effect in oral squamous cell carcinoma (OSCC). Materials and methods: First we checked G9a expression in two OSCC cell lines Tca8113 and KB. Next we used a special G9a inhibitor BIX01294 (BIX) to explore the effect of inhibition of G9a on OSCC in vitro. Cell growth was tested by typlan blue staining, MTT assay and Brdu immunofluorescence staining. Cell autophagy was examined by monodansylcadaverine (MDC) staining, LC3-II immunofluorescence staining and LC3-II western blot assay. Cell apoptosis was checked by FITC Annexin-V and PI labeling, tunnel staining and caspase 3 western blot assay. Finally, the effect of inhibition of G9a on clonogenesis and tumorigenesis capacity of OSCC was analyzed by soft agar growth and xenograft model. Results: Here we showed that G9a was expressed in both Tca8113 and KB cells. Inhibition of G9a using BIX significantly reduced cell growth and proliferation in Tca8113 and KB. Inhibition of G9a induced cell autophagy with conversion of LC3-I to LC3-II and cell apoptosis with the expression of cleaved caspase 3. We also found that inhibition of G9a reduced colony formation in soft agar and repressed tumor growth in mouse xenograph model. Conclusion: Our results suggested that G9a might be a potential epigenetic target for OSCC treatment. - Highlights: • Inhibition of G9a reduced cell growth and proliferation in OSCC cells. • Inhibition of G9a induces autophagy and apoptosis in OSCC cells. • Inhibition of G9a repressed tumor growth in mouse xenograph model.

  8. Neuroprotective effect of S-allyl-l-cysteine derivatives against endoplasmic reticulum stress-induced cytotoxicity is independent of calpain inhibition.

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    Imai, Toru; Kosuge, Yasuhiro; Saito, Hiroaki; Uchiyama, Taketo; Wada, Taira; Shimba, Shigeki; Ishige, Kumiko; Miyairi, Shinichi; Makishima, Makoto; Ito, Yoshihisa

    2016-03-01

    S-allyl-l-cysteine (SAC) is known to have neuroprotective properties. We synthesized various SAC derivatives and tested their effects on endoplasmic reticulum stress-induced neurotoxicity in cultured hippocampal neurons (HPNs). Among the compounds tested, S-propyl-l-cysteine (SPC) exhibited the strongest neuroprotective activity in HPNs, followed by S-ethyl-l-cysteine (SEC) and S-methyl-l-cysteine (SMC). Unlike SAC and SMC, SPC and SEC did not have inhibitory activity on μ-calpain, suggesting that the mechanism underlying the protective activity of SPC and SEC differs from that of SAC. Copyright © 2016 Japanese Pharmacological Society. Production and hosting by Elsevier B.V. All rights reserved.

  9. Kinetics of radiation-induced apoptosis in neonatal urogenital tissues with and without protein synthesis inhibition

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    Gobe, G.C.; Harmon, B.; Schoch, E.; Allan, D.J.

    1996-01-01

    The difference in incidence of radiation-induced apoptosis between two neonatal urogenital tissues, kidney and testis, was analysed over a 24h period. Concurrent administration of cycloheximide (10mg/kg body weight), a protein synthesis inhibitor, with radiation treatment was used to determine whether new protein synthesis had a role in induction of apoptosis in this in vivo model. Many chemotherapeutic drugs act via protein synthesis inhibition, and we believe that the results of this latter analysis may provide information for the planning of concurrent radio and chemotherapy. Apoptosis was quantified using morphological parameters, and verified by DNA gel electrophoresis for the typical banding pattern, and by electron microscopy. The proliferative index in tissues was studied, using [6- 3 H]-thymidine uptake ( 1h prior to euthanasia and collection of tissues) and autoradiography as indicators of cell proliferation (S-phase). Tissue was collected 2, 4, 6, 8, and 24h after radiation treatment. Expression of one of the apoptosis-associated genes, Bcl-2 (an apoptosis inhibitor/cell survival gene), was studied using immunohistochemistry. Apoptosis peaked at 4h in the testis and 6h in the kidney, emphasising the necessity of knowing tissue differences in radiation response if comparing changes at a particular time. A higher proportion (almost five fold) of the apoptotic cells died in S-phase in the kidney than the testis, over the 24h. Protein synthesis inhibition completely negated induction of apoptosis in both tissues. Necrosis was not identified at any time. Cycloheximide treatment greatly diminished Bcl-2 expression. The differences in response of the two tissues to irradiation relates to their innate cell (genetic) controls, which may be determined by their state of differentiation at time of treatment, or the tissue type. This in vivo study also suggests the model may be useful for analysis of other cancer therapies for example polychemotherapies or chemo

  10. Dehydroabietic Acid Derivative QC4 Induces Gastric Cancer Cell Death via Oncosis and Apoptosis

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    Dongjun Luo

    2016-01-01

    Full Text Available Aim. QC4 is the derivative of rosin’s main components dehydroabietic acid (DHA. We investigated the cytotoxic effect of QC4 on gastric cancer cells and revealed the mechanisms beneath the induction of cell death. Methods. The cytotoxic effect of QC4 on gastric cancer cells was evaluated by CCK-8 assay and flow cytometry. The underlying mechanisms were tested by administration of cell death related inhibitors and detection of apoptotic and oncosis related proteins. Cytomembrane integrity and organelles damage were confirmed by lactate dehydrogenase (LDH leakage assay, mitochondrial function test, and cytosolic free Ca2+ concentration detection. Results. QC4 inhibited cell proliferation dose- and time-dependently and destroyed cell membrane integrity, activated calpain-1 autolysis, and induced apoptotic protein cleavage in gastric cancer cells. The detection of decreased ATP and mitochondrial membrane potential, ROS accumulation, and cytosolic free Ca2+ elevation confirmed organelles damage in QC4-treated gastric cancer cells. Conclusions. DHA derivative QC4 induced the damage of cytomembrane and organelles which finally lead to oncosis and apoptosis in gastric cancer cells. Therefore, as a derivative of plant derived small molecule DHA, QC4 might become a promising agent in gastric cancer therapy.

  11. Alpha cyano-4-hydroxy-3-methoxycinnamic acid inhibits proliferation and induces apoptosis in human breast cancer cells.

    Science.gov (United States)

    Hamdan, Lamia; Arrar, Zoheir; Al Muataz, Yacoub; Suleiman, Lutfi; Négrier, Claude; Mulengi, Joseph Kajima; Boukerche, Habib

    2013-01-01

    This study investigated the underlying mechanism of 4-hydroxy-3-methoxycinnamic acid (ACCA), on the growth of breast cancer cells and normal immortal epithelial cells, and compared their cytotoxic effects responses. Treatment of breast cancer cells (MCF-7, T47D, and MDA-231) with ACCA resulted in dose- and time-dependent decrease of cell proliferation, viability in colony formation assay, and programmed cell death (apoptosis) with minimal effects on non-tumoral cells. The ability of ACCA to suppress growth in cancer cells not expressing or containing defects in p53 gene indicates a lack of involvement of this critical tumor suppressor element in mediating ACCA-induced growth inhibition. Induction of apoptosis correlated with an increase in Bax protein, an established inducer of programmed cell death, and the ratio of Bax to Bcl-2, an established inhibitor of apoptosis. We also documented the ability of ACCA to inhibit the migration and invasion of MDA-231 cells with ACCA in vitro. Additionally, tumor growth of MDA-231 breast cancer cells in vivo was dramatically affected with ACCA. On the basis of its selective anticancer inhibitory activity on tumor cells, ACCA may represent a promising therapeutic drug that should be further evaluated as a chemotherapeutic agent for human breast cancer.

  12. Alpha cyano-4-hydroxy-3-methoxycinnamic acid inhibits proliferation and induces apoptosis in human breast cancer cells.

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    Lamia Hamdan

    Full Text Available This study investigated the underlying mechanism of 4-hydroxy-3-methoxycinnamic acid (ACCA, on the growth of breast cancer cells and normal immortal epithelial cells, and compared their cytotoxic effects responses. Treatment of breast cancer cells (MCF-7, T47D, and MDA-231 with ACCA resulted in dose- and time-dependent decrease of cell proliferation, viability in colony formation assay, and programmed cell death (apoptosis with minimal effects on non-tumoral cells. The ability of ACCA to suppress growth in cancer cells not expressing or containing defects in p53 gene indicates a lack of involvement of this critical tumor suppressor element in mediating ACCA-induced growth inhibition. Induction of apoptosis correlated with an increase in Bax protein, an established inducer of programmed cell death, and the ratio of Bax to Bcl-2, an established inhibitor of apoptosis. We also documented the ability of ACCA to inhibit the migration and invasion of MDA-231 cells with ACCA in vitro. Additionally, tumor growth of MDA-231 breast cancer cells in vivo was dramatically affected with ACCA. On the basis of its selective anticancer inhibitory activity on tumor cells, ACCA may represent a promising therapeutic drug that should be further evaluated as a chemotherapeutic agent for human breast cancer.

  13. Taurine Pretreatment Prevents Isoflurane-Induced Cognitive Impairment by Inhibiting ER Stress-Mediated Activation of Apoptosis Pathways in the Hippocampus in Aged Rats.

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    Zhang, Yanan; Li, Dongliang; Li, Haiou; Hou, Dailiang; Hou, Jingdong

    2016-10-01

    Isoflurane, a commonly used inhalation anesthetic, may induce neurocognitive deficits, especially in elderly patients after surgery. Recent study demonstrated that isoflurane caused endoplasmic reticulum (ER) stress and subsequent neuronal apoptosis in the brain, contributing to cognitive deficits. Taurine, a major intracellular free amino acid, has been shown to inhibit ER stress and neuronal apoptosis in several neurological disorders. Here, we examined whether taurine can prevent isoflurane-induced ER stress and cognitive impairment in aged rats. Thirty minutes prior to a 4-h 1.3 % isoflurane exposure, aged rats were treated with vehicle or taurine at low, middle and high doses. Aged rats without any treatment served as control. The brains were harvested 6 h after isoflurane exposure for molecular measurements, and behavioral study was performed 2 weeks later. Compared with control, isoflurane increased expression of hippocampal ER stress biomarkers including glucose-regulated protein 78, phosphorylated (P-) inositol-requiring enzyme 1, P-eukaryotic initiation factor 2-α (EIF2α), activating transcription factor 4 (ATF-4), cleaved ATF-6 and C/EBP homologous protein, along with activation of apoptosis pathways as indicated by decreased B cell lymphoma 2 (BCL-2)/BCL2-associated X protein, increased expressions of cytochrome-c and cleaved caspase-3. Taurine pretreatment dose-dependently inhibited isoflurane-induced increase in expression of ER stress biomarkers except for P-EIF2α and ATF-4, and reversed isoflurane-induced changes in apoptosis-related proteins. Moreover, isoflurane caused spatial working memory deficits in aged rats, which were prevented by taurine pretreatment. The results indicate that taurine pretreatment prevents anesthetic isoflurane-induced cognitive impairment by inhibiting ER stress-mediated activation of apoptosis pathways in the hippocampus in aged rats.

  14. Andrographolide Attenuates LPS-Induced Cardiac Malfunctions Through Inhibition of IκB Phosphorylation and Apoptosis in Mice

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    Jinlong Zhang

    2015-11-01

    Full Text Available Background/Aims: Cardiac malfunction is a common complication in sepsis and significantly increases the mortality of patients in septic shock. However, no studies have examined whether andrographolide (And reduces LPS-induced myocardial malfunction. Methods: Left ventricular systolic and diastolic functions were examined using echocardiography. TNF-a and IL-1ß protein levels were detected by an enzyme-linked immunosorbent assay (ELISA. NO oxidation products were determined using Griess reagent. Protein expression levels of inhibitors of NF-κBa (IκB and phospho-IκB were determined via Western blot. Oxidative injury was determined by measuring myocardial lipid peroxidation and superoxide dismutase activity. Cardiac apoptosis was examined by terminal deoxynucleotidyl transferase-mediated dUTP nickend-labeling (TUNEL and cardiac caspase 3/7 activity. Results: And blunted LPS-induced myocardial malfunctions in mice. LPS induced TNF-a, IL-1ß, and NO production as well as I-κB phosphorylation. Cardiac apoptosis was attenuated via incubation with And, but the extent of oxidative injury remained unaffected. Conclusion: And prevents LPS-induced cardiac malfunctions in mice by inhibiting TNF-a, IL-1ß, and NO production, IκB phosphorylation, and cardiac apoptosis, indicating that And may be a potential agent for preventing myocardial malfunction during sepsis.

  15. Interaction of caveolin-1 with Ku70 inhibits Bax-mediated apoptosis.

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    Huafei Zou

    Full Text Available Caveolin-1, the structural protein component of caveolae, acts as a scaffolding protein that functionally regulates signaling molecules. We show that knockdown of caveolin-1 protein expression enhances chemotherapeutic drug-induced apoptosis and inhibits long-term survival of colon cancer cells. In vitro studies demonstrate that caveolin-1 is a novel Ku70-binding protein, as shown by the binding of the scaffolding domain of caveolin-1 (amino acids 82-101 to the caveolin-binding domain (CBD of Ku70 (amino acids 471-478. Cell culture data show that caveolin-1 binds Ku70 after treatment with chemotherapeutic drugs. Mechanistically, we found that binding of caveolin-1 to Ku70 inhibits the chemotherapeutic drug-induced release of Bax from Ku70, activation of Bax, translocation of Bax to mitochondria and apoptosis. Potentiation of apoptosis by knockdown of caveolin-1 protein expression is greatly reduced in the absence of Bax expression. Finally, we found that overexpression of wild type Ku70, but not a mutant form of Ku70 that cannot bind to caveolin-1 (Ku70 Φ→A, limits the chemotherapeutic drug-induced Ku70/Bax dissociation and apoptosis. Thus, caveolin-1 acts as an anti-apoptotic protein in colon cancer cells by binding to Ku70 and inhibiting Bax-dependent cell death.

  16. Dexamethasone enhances necrosis-like neuronal death in ischemic rat hippocampus involving μ-calpain activation

    DEFF Research Database (Denmark)

    Müller, Georg Johannes; Hasseldam, Henrik; Rasmussen, Rune Skovgaard

    2014-01-01

    - and necrosis-like cell death morphologies in CA1 of rats treated with dexamethasone prior to TFI (DPTI). In addition, apoptosis- (casp-9, casp-3, casp-3-cleaved PARP and cleaved α-spectrin 145/150 and 120kDa) and necrosis-related (calpain-specific casp-9 cleavage, μ-calpain upregulation and cleaved α......Transient forebrain ischemia (TFI) leads to hippocampal CA1 pyramidal cell death which is aggravated by glucocorticoids (GC). It is unknown how GC affect apoptosis and necrosis in cerebral ischemia. We therefore investigated the co-localization of activated caspase-3 (casp-3) with apoptosis......-spectrin 145/150kDa) cell death mechanisms were investigated by Western blot analysis. DPTI expedited CA1 neuronal death from day 4 to day 1 and increased the magnitude of CA1 neuronal death from 66.2% to 91.3% at day 7. Furthermore, DPTI decreased the overall (days 1-7) percentage of dying neurons displaying...

  17. Glycidamide inhibits progesterone production through reactive oxygen species-induced apoptosis in R2C Rat Leydig Cells.

    Science.gov (United States)

    Li, Mingwei; Sun, Jianxia; Zou, Feiyan; Bai, Shun; Jiang, Xinwei; Jiao, Rui; Ou, Shiyi; Zhang, Hui; Su, Zhijian; Huang, Yadong; Bai, Weibin

    2017-10-01

    The food contaminant acrylamide (AA) is usually recognized as a probable human carcinogen. In addition, AA has also been found able to induce male infertility in animals. Interestingly, resent research work revealed that the toxic effect of AA on the ability of male reproduction in vivo may due to glycidamide (GA) which is the metabolite of AA. In this study, R2C Leydig cells was used to investigate the toxic effects of GA on progesterone production. GA caused dose-dependent inhibition on the cell growth, with IC 25 , IC 50, and IC 75 values found at 0.635, 0.872, and 1.198 mM, respectively. The results of single cell gel/Comet assay showed that GA significantly induced early-phase cell apoptosis, reduced progesterone production, as well as decreasing the protein expression of steroidogenic acute regulatory (StAR) in R2C cells. Furthermore, GA induced overproduction of intracellular reactive oxygen species (ROS), upregulated Bax expression, decreased mitochondrial membrane potential, and triggered mitochondria-mediated cell apoptosis. Consequently, the downstream effector caspase-3 was activated, resulting in Leydig cells apoptosis. Overall, our results showed that GA could damage R2C Leydig cells by the lesion of the ability of progesterone genesis and inducing cells apoptosis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Combination of α-Tomatine and Curcumin Inhibits Growth and Induces Apoptosis in Human Prostate Cancer Cells.

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    Huarong Huang

    Full Text Available α-Tomatine is a glycoalkaloid found in tomatoes and curcumin is a major yellow pigment of turmeric. In the present study, the combined effect of these two compounds on prostate cancer cells was studied. Treatment of different prostate cancer cells with curcumin or α-tomatine alone resulted in growth inhibition and apoptosis in a concentration-dependent manner. Combinations of α-tomatine and curcumin synergistically inhibited the growth and induced apoptosis in prostate cancer PC-3 cells. Effects of the α-tomatine and curcumin combination were associated with synergistic inhibition of NF-κB activity and a potent decrease in the expression of its downstream gene Bcl-2 in the cells. Moreover, strong decreases in the levels of phospho-Akt and phosphor-ERK1/2 were found in PC-3 cells treated with α-tomatine and curcumin in combination. In animal experiment, SCID mice with PC-3 xenograft tumors were treated with α-tomatine and curcumin. Combination of α-tomatine and curcumin more potently inhibited the growth of PC-3 tumors than either agent alone. Results from the present study indicate that α-tomatine in combination with curcumin may be an effective strategy for inhibiting the growth of prostate cancer.

  19. Overexpression of the long noncoding RNA TUG1 protects against cold-induced injury of mouse livers by inhibiting apoptosis and inflammation.

    Science.gov (United States)

    Su, Song; Liu, Jiang; He, Kai; Zhang, Mengyu; Feng, Chunhong; Peng, Fangyi; Li, Bo; Xia, Xianming

    2016-04-01

    Hepatic injury provoked by cold storage is a major problem affecting liver transplantation, as exposure to cold induces apoptosis in hepatic tissues. Long noncoding RNAs (lncRNAs) are increasingly understood to regulate apoptosis, but the contribution of lncRNAs to cold-induced liver injury remains unknown. Using RNA-seq, we determined the differential lncRNA expression profile in mouse livers after cold storage and found that expression of the lncRNA TUG1 was significantly down-regulated. Overexpression of TUG1 attenuated cold-induced apoptosis in mouse hepatocytes and liver sinusoidal endothelial cells LSECs, in part by blocking mitochondrial apoptosis and endoplasmic reticulum (ER) stress pathways. Moreover, TUG1 attenuated apoptosis, inflammation, and oxidative stress in vivo in livers subjected to cold storage. Overexpression of TUG1 also improved hepatocyte function and prolonged hepatic graft survival rates in mice. These results suggest that the lncRNA TUG1 exerts a protective effect against cold-induced liver damage by inhibiting apoptosis in mice, and suggests a potential role for TUG1 as a target for the prevention of cold-induced liver damage in liver transplantation. RNA-seq data are available from GEO using accession number GSE76609. © 2016 Federation of European Biochemical Societies.

  20. 2,5-hexanedione induces bone marrow mesenchymal stem cell apoptosis via inhibition of Akt/Bad signal pathway.

    Science.gov (United States)

    Sun, Jingsong; Shi, Xiaoxia; Li, Shuangyue; Piao, Fengyuan

    2018-04-01

    2,5-Hexanedione (HD) is an important bioactive metabolite of n-hexane and mediates the neurotoxicity of parent compound. Studies show that HD induces apoptotic death of neural progenitor cells. However, its underlying mechanism remains unknown. Mesenchymal stem cells (MSCs) are multipotential stem cells with the ability to differentiate into various cell types and have been used as cell model for studying the toxic effects of chemicals on stem cells. In this study, we exposed rat bone marrow MSCs to 0, 10, 20, and 40 mM HD in vitro. Apoptosis and disruption of mitochondrial transmembrane potential were estimated by immunochemistry staining. The expression of Akt, Bad, phosphorylated Akt (p-Akt), and Bad (p-Bad) as well as cytochrome c in mitochondria and cytosol were examined by Western blot. Moreover, caspase 3 activity, viability, and death of cells were measured by spectrophotometry. Our results showed that HD induced cell apoptosis and increased caspase 3 activity. HD down-regulated the expression levels of p-Akt, p-Bad and induced MMP depolarization, followed by cytochrome c release. Moreover, HD led to a concentration-dependent increase in the MSCs death, which was relative to MSCs apoptosis. However, these toxic effects of HD on the MSCs were significantly mitigated in the presence of IGF, which could activate PI3 K/Akt pathway. These results indicated that HD induced mitochondria-mediated apoptosis in the MSCs via inhibiting Akt/Bad signaling pathway and apoptotic death of MSCs via the signaling pathway. These results might provide some clues for studying further the mechanisms of HD-induced stem cell apoptosis and adverse effect on neurogenesis. © 2017 Wiley Periodicals, Inc.

  1. TNF/TNFR1 pathway and endoplasmic reticulum stress are involved in ofloxacin-induced apoptosis of juvenile canine chondrocytes

    International Nuclear Information System (INIS)

    Zhang, Fu-Tao; Ding, Yi; Shah, Zahir; Xing, Dan; Gao, Yuan; Liu, Dong Ming; Ding, Ming-Xing

    2014-01-01

    Background and purpose: Quinolones cause obvious cartilaginous lesions in juvenile animals by chondrocyte apoptosis, which results in the restriction of their use in pediatric and adolescent patients. Studies showed that chondrocytes can be induced to produce TNFα, and the cisternae of the endoplasmic reticulum in quinolone-treated chondrocytes become dilated. We investigated whether TNF/TNFR 1 pathway and endoplasmic reticulum stress (ERs) are involved in ofloxacin (a typical quinolone)-induced apoptosis of juvenile canine chondrocytes. Experimental approach: Canine juvenile chondrocytes were treated with ofloxacin. Cell survival and apoptosis rates were determined with MTT method and flow cytometry, respectively. The gene expression levels of the related signaling molecules (TNFα, TNFR 1 , TRADD, FADD and caspase-8) in death receptor pathways and main apoptosis-related molecules (calpain, caspase-12, GADD153 and GRP78) in ERs were measured by qRT-PCR. The gene expression of TNFR 1 was suppressed with its siRNA. The protein levels of TNFα, TNFR 1 and caspase-12 were assayed using Western blotting. Key results: The survival rates decreased while apoptosis rates increased after the chondrocytes were treated with ofloxacin. The mRNA levels of the measured apoptosis-related molecules in death receptor pathways and ERs, and the protein levels of TNFα, TNFR 1 and caspase-12 increased after the chondrocytes were exposed to ofloxacin. The downregulated mRNA expressions of TNFR 1 , Caspase-8 and TRADD, and the decreased apoptosis rates of the ofloxacin-treated chondrocytes occurred after TNFR 1 –siRNA interference. Conclusions and implications: Ofloxacin-induced chondrocyte apoptosis in a time- and concentration-dependent fashion. TNF/TNFR 1 pathway and ERs are involved in ofloxacin-induced apoptosis of juvenile canine chondrocytes in the early stage. - Highlights: • Chondrocyte apoptosis is induced by ofloxacin in a time- and concentration-dependent manners.

  2. Effect of protein S-nitrosylation on autolysis and catalytic ability of μ-calpain.

    Science.gov (United States)

    Liu, Rui; Li, Yupin; Wang, Mengqin; Zhou, Guanghong; Zhang, Wangang

    2016-12-15

    The effect of S-nitrosylation on the autolysis and catalytic ability of μ-calpain in vitro in the presence of 50μM Ca(2 +) was investigated. μ-Calpain was incubated with different concentrations of nitric oxide donor S-nitrosoglutathione (GSNO) and subsequently reacted with purified myofibrils. Results showed that the amount of 80kDa μ-calpain subunit significantly decreased as GSNO increased from 0 to 300μM, but increases of GSNO to 300, 500 and 1000μM did not result in further inhibition. The catalytic ability of nitrosylated μ-calpain to degrade titin, nebulin, troponin-T and desmin was significantly reduced when the GSNO concentration was higher than 300μM. The cysteine residues of μ-calpain at positions 49, 351, 384, and 592 in the catalytic subunit and at 142 in small subunit were S-nitrosylated, which could be responsible for decreased μ-calpain activity. Thus, S-nitrosylation can negatively regulate the activation of μ-calpain resulting in decreased proteolytic ability on myofibrils. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Resveratrol induces growth arrest and apoptosis through activation of FOXO transcription factors in prostate cancer cells.

    Directory of Open Access Journals (Sweden)

    Qinghe Chen

    2010-12-01

    Full Text Available Resveratrol, a naturally occurring phytopolyphenol compound, has attracted extensive interest in recent years because of its diverse pharmacological characteristics. Although resveratrol possesses chemopreventive properties against several cancers, the molecular mechanisms by which it inhibits cell growth and induces apoptosis have not been clearly understood. The present study was carried out to examine whether PI3K/AKT/FOXO pathway mediates the biological effects of resveratrol.Resveratrol inhibited the phosphorylation of PI3K, AKT and mTOR. Resveratrol, PI3K inhibitors (LY294002 and Wortmannin and AKT inhibitor alone slightly induced apoptosis in LNCaP cells. These inhibitors further enhanced the apoptosis-inducing potential of resveratrol. Overexpression of wild-type PTEN slightly induced apoptosis. Wild type PTEN and PTEN-G129E enhanced resveratrol-induced apoptosis, whereas PTEN-G129R had no effect on proapoptotic effects of resveratrol. Furthermore, apoptosis-inducing potential of resveratrol was enhanced by dominant negative AKT, and inhibited by wild-type AKT and constitutively active AKT. Resveratrol has no effect on the expression of FKHR, FKHRL1 and AFX genes. The inhibition of FOXO phosphorylation by resveratrol resulted in its nuclear translocation, DNA binding and transcriptional activity. The inhibition of PI3K/AKT pathway induced FOXO transcriptional activity resulting in induction of Bim, TRAIL, p27/KIP1, DR4 and DR5, and inhibition of cyclin D1. Similarly, resveratrol-induced FOXO transcriptional activity was further enhanced when activation of PI3K/AKT pathway was blocked. Over-expression of phosphorylation deficient mutants of FOXO proteins (FOXO1-TM, FOXO3A-TM and FOXO4-TM induced FOXO transcriptional activity, which was further enhanced by resveratrol. Inhibition of FOXO transcription factors by shRNA blocked resveratrol-induced upregulation of Bim, TRAIL, DR4, DR5, p27/KIP1 and apoptosis, and inhibition of cyclin D1 by

  4. Mitochondrial dysfunction is responsible for fatty acid synthase inhibition-induced apoptosis in breast cancer cells by PdpaMn.

    Science.gov (United States)

    Wang, Qiang; Du, Xia; Zhou, Bingjie; Li, Jing; Lu, Wenlong; Chen, Qiuyun; Gao, Jing

    2017-12-01

    Targeting cellular metabolism is becoming a hallmark to overcome drug resistance in breast cancer treatment. Activation of fatty acid synthase (FASN) has been shown to promote breast cancer cell growth. However, there is no concrete report underlying the mechanism associated with mitochondrial dysfunction in relation to fatty acid synthase inhibition-induced apoptosis in breast cancer cells. The current study is aimed at exploring the effect of the novel manganese (Mn) complex, labeled as PdpaMn, on lipid metabolism and mitochondrial function in breast cancer cells. Herein, we observed that PdpaMn displayed strong cytotoxicity on breast cancer cell lines and selectively targeted the tumor without affecting the normal organs or cells in vivo. We also observed that PdpaMn could bind to TE domain of FASN and decrease the activity and the level of expression of FASN, which is an indication that FASN could serve as a target of PdpaMn. In addition, we demonstrated that PdpaMn increased intrinsic apoptosis in breast cancer cells relayed by a suppressed the level of expression of FASN, followed by the release of mitochondrial cytochrome c and the activation of caspases-9. Instigated by the above observations, we hypothesized that PdpaMn-induced apoptosis events are dependent on mitochondrial dysfunction. Indeed, we found that mitochondrial membrane potential (MMP) collapse, mitochondrial oxygen consumption reduction and adenosine triphosphate (ATP) release were deeply repressed. Furthermore, our results showed that PdpaMn significantly increased the reactive oxygen species (ROS) production, and the protection conferred by the free radical scavenger N-acetyl-cysteine (NAC) indicates that PdpaMn-induced apoptosis through an oxidative stress-associated mechanism. More so, the above results have demonstrated that mitochondrial dysfunction participated in FASN inhibition-induce apoptosis in breast cancer cells by PdpaMn. Therefore, PdpaMn may be considered as a good candidate

  5. Lithium protects ethanol-induced neuronal apoptosis

    International Nuclear Information System (INIS)

    Zhong Jin; Yang Xianlin; Yao Weiguo; Lee Weihua

    2006-01-01

    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 synthase3β, because neither ethanol nor lithium has significant effects on the phosphorylation of Akt (ser473) or GSK3β (ser9). In addition, the selective GSK-3β 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

  6. Andrographolide Analogue Induces Apoptosis and Autophagy Mediated Cell Death in U937 Cells by Inhibition of PI3K/Akt/mTOR Pathway.

    Directory of Open Access Journals (Sweden)

    Deepak Kumar

    Full Text Available Current chemotherapeutic agents based on apoptosis induction are lacking in desired efficacy. Therefore, there is continuous effort to bring about new dimension in control and gradual eradication of cancer by means of ever evolving therapeutic strategies. Various forms of PCD are being increasingly implicated in anti-cancer therapy and the complex interplay among them is vital for the ultimate fate of proliferating cells. We elaborated and illustrated the underlying mechanism of the most potent Andrographolide analogue (AG-4 mediated action that involved the induction of dual modes of cell death-apoptosis and autophagy in human leukemic U937 cells.AG-4 induced cytotoxicity was associated with redox imbalance and apoptosis which involved mitochondrial depolarisation, altered apoptotic protein expressions, activation of the caspase cascade leading to cell cycle arrest. Incubation with caspase inhibitor Z-VAD-fmk or Bax siRNA decreased cytotoxic efficacy of AG-4 emphasising critical roles of caspase and Bax. In addition, AG-4 induced autophagy as evident from LC3-II accumulation, increased Atg protein expressions and autophagosome formation. Pre-treatment with 3-MA or Atg 5 siRNA suppressed the cytotoxic effect of AG-4 implying the pro-death role of autophagy. Furthermore, incubation with Z-VAD-fmk or Bax siRNA subdued AG-4 induced autophagy and pre-treatment with 3-MA or Atg 5 siRNA curbed AG-4 induced apoptosis-implying that apoptosis and autophagy acted as partners in the context of AG-4 mediated action. AG-4 also inhibited PI3K/Akt/mTOR pathway. Inhibition of mTOR or Akt augmented AG-4 induced apoptosis and autophagy signifying its crucial role in its mechanism of action.Thus, these findings prove the dual ability of AG-4 to induce apoptosis and autophagy which provide a new perspective to it as a potential molecule targeting PCD for future cancer therapeutics.

  7. Effect of cycloheximide and actinomycin D on radionuclide 235U-induced apoptosis

    International Nuclear Information System (INIS)

    Fu Qiang; Zhang Lansheng; Zhu Shoupeng

    1999-01-01

    Objective: The mechanism of apoptosis induced by radionuclide 235 U was studied. Methods: MTT and JAM assay were used to analyse the cell viability and quantification of fragmented DNA. Results: The inhibitor of protein cycloheximide (CHX), and the inhibitor of RNA synthesis, actinomycin D. cannot inhibit the apoptosis induced by 235 U, but CHX can partly inhibit apoptotic cells DNA fragmentation. Conclusion: The pathway of apoptosis induced by radionuclide 235 U is different from X-and γ-ray external irradiation, protein synthesis is not essential for it, but synthetic endonuclease is necessary for DNA fragmentation of apoptotic cells

  8. Physcion induces mitochondria-driven apoptosis in colorectal cancer cells via downregulating EMMPRIN.

    Science.gov (United States)

    Chen, Xuehong; Gao, Hui; Han, Yantao; Ye, Junli; Xie, Jing; Wang, Chunbo

    2015-10-05

    Physcion, an anthraquinone derivative widely isolated and characterized from both terrestrial and marine sources, has anti-tumor effects on a variety of carcinoma cells, mainly through inhibition of cell proliferation, apoptosis induction and cell cycle arrest. However, little is known about the mechanisms underlying its role in tumor progression. In the present study, we investigated the molecular mechanisms involved in physcion-induced apoptosis in human colorectal cancer (CRC) lines HCT116. Our results showed that physcion inhibited tumor cell viability in a dose- and time-dependent manner, and induced cell apoptosis via intrinsic mitochondrial pathway. Our results also revealed that physcion treatment significantly inhibited extracelluar matrix metalloproteinase inducer (EMMPRIN) expression in HCT116 cells in a dose-dependent manner and overexpression of EMMPRIN protein markedly reduced physcion-induced cell apoptosis. Furthermore, our results strongly indicated the modulating effect of physcion on EMMPRIN is correlated with AMP-activated protein kinase (AMPK)/Hypoxia-inducible factor 1α (HIF-1α) signaling pathway. Our data provide the first experimental evidence that physcion induces mitochondrial apoptosis in CRC cells by downregulating of EMMPRIN via AMPK/HIF-1α signaling pathway and suggest a new mechanism to explain its anti-tumor effects. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Novel Triazole linked 2-phenyl benzoxazole derivatives induce apoptosis by inhibiting miR-2, miR-13 and miR-14 function in Drosophila melanogaster.

    Science.gov (United States)

    Mondal, Tanmoy; Lavanya, A V S; Mallick, Akash; Dadmala, Tulshiram L; Kumbhare, Ravindra M; Bhadra, Utpal; Bhadra, Manika Pal

    2017-06-01

    Apoptosis is an important phenomenon in multi cellular organisms for maintaining tissue homeostasis and embryonic development. Defect in apoptosis leads to a number of disorders like- autoimmune disorder, immunodeficiency and cancer. 21-22 nucleotides containing micro RNAs (miRNAs/miRs) function as a crucial regulator of apoptosis alike other cellular pathways. Recently, small molecules have been identified as a potent inducer of apoptosis. In this study, we have identified novel Triazole linked 2-phenyl benzoxazole derivatives (13j and 13h) as a negative regulator of apoptosis inhibiting micro RNAs (miR-2, miR-13 and miR-14) in a well established in vivo model Drosophila melanogaster where the process of apoptosis is very similar to human apoptosis. These compounds inhibit miR-2, miR-13 and miR-14 activity at their target sites, which induce an increased caspase activity, and in turn influence the caspase dependent apoptotic pathway. These two compounds also increase the mitochondrial reactive oxygen species (ROS) level to trigger apoptotic cell death.

  10. Morin Inhibits Proliferation of SW480 Colorectal Cancer Cells by Inducing Apoptosis Mediated by Reactive Oxygen Species Formation and Uncoupling of Warburg Effect

    Directory of Open Access Journals (Sweden)

    Thomas Sithara

    2017-09-01

    Full Text Available The study under investigation focuses on in vitro antiproliferative efficacy of the flavonoid morin and the mechanisms by which it inhibits the growth of colon cancer using SW480 colon cancer cells with emphasis on Warburg effect. It was found that the cell proliferation was significantly inhibited by morin in a dose and time dependent manner. Morin induced apoptosis that was correlated with increased levels of reactive oxygen species formation and loss of mitochondrial membrane potential of the cells. In addition, an increase in cleaved PARP, cleaved caspase 3, cleaved caspase 8, cleaved caspase 9 and Bax as well as a decrease in Bcl 2 was observed, indicating morin is inducing both intrinsic as well as extrinsic pathway of apoptosis. This was further confirmed by using downstream caspase 3 inhibitor which indicated that caspase 3 inhibition reduces morin induced cell death. Moreover, the impact of morin on over all energy status when determined in terms of total cellular ATP level showed a decline with low level of glucose uptake and Glut1 expression. The results indicate that morin exerts antiproliferative activity by inducing apoptosis and by reducing Warburg effect in the evaluated cell lines and provide preliminary evidence for its anticancer activity.

  11. Indirubin-3-Oxime Prevents H2O2-Induced Neuronal Apoptosis via Concurrently Inhibiting GSK3β and the ERK Pathway.

    Science.gov (United States)

    Yu, Jie; Zheng, Jiacheng; Lin, Jiajia; Jin, Linlu; Yu, Rui; Mak, Shinghung; Hu, Shengquan; Sun, Hongya; Wu, Xiang; Zhang, Zaijun; Lee, Mingyuen; Tsim, Wahkeung; Su, Wei; Zhou, Wenhua; Cui, Wei; Han, Yifan; Wang, Qinwen

    2017-05-01

    Oxidative stress-induced neuronal apoptosis plays an important role in many neurodegenerative disorders. In this study, we have shown that indirubin-3-oxime, a derivative of indirubin originally designed for leukemia therapy, could prevent hydrogen peroxide (H 2 O 2 )-induced apoptosis in both SH-SY5Y cells and primary cerebellar granule neurons. H 2 O 2 exposure led to the increased activities of glycogen synthase kinase 3β (GSK3β) and extracellular signal-regulated kinase (ERK) in SH-SY5Y cells. Indirubin-3-oxime treatment significantly reversed the altered activity of both the PI3-K/Akt/GSK3β cascade and the ERK pathway induced by H 2 O 2 . In addition, both GSK3β and mitogen-activated protein kinase inhibitors significantly prevented H 2 O 2 -induced neuronal apoptosis. Moreover, specific inhibitors of the phosphoinositide 3-kinase (PI3-K) abolished the neuroprotective effects of indirubin-3-oxime against H 2 O 2 -induced neuronal apoptosis. These results strongly suggest that indirubin-3-oxime prevents H 2 O 2 -induced apoptosis via concurrent inhibiting GSK3β and the ERK pathway in SH-SY5Y cells, providing support for the use of indirubin-3-oxime to treat neurodegenerative disorders caused or exacerbated by oxidative stress.

  12. Cetuximab enhances cisplatin-induced endoplasmic reticulum stress-associated apoptosis in laryngeal squamous cell carcinoma cells by inhibiting expression of TXNDC5.

    Science.gov (United States)

    Peng, Fusen; Zhang, Hailin; Du, Youhong; Tan, Pingqing

    2018-03-01

    Cisplatin and cetuximab, an anti‑epidermal growth factor receptor (EGFR) monoclonal humanized antibody, have been used for treatment of laryngeal squamous cell carcinoma (LSCC). It has been demonstrated that cisplatin and inhibition of EGFR signaling may induce endoplasmic reticulum (ER) stress‑associated apoptosis. However, ER protein thioredoxin domain‑containing protein 5 (TXNDC5) reportedly protects cells from ER stress‑associated apoptosis. The present study investigated the interaction between cisplatin, cetuximab and TXNDC5 on ER stress‑associated apoptosis in LSCC cells. AMC‑HN‑8 human LSCC cells with or without TXNDC5 overexpression or knockdown were treated with cisplatin (5, 10, 20 and 40 µM) and/or cetuximab (10, 50, 100 and 150 µg/ml), for 12, 24, 36 and 48 h. Cisplatin and cetuximab concentration‑ and time‑dependently increased and decreased the expression of TXNDC5 in AMC‑HN‑8 cells, respectively. Knockdown of TXNDC5 markedly augmented cisplatin‑induced levels of CCAAT/enhancer‑binding protein homologous protein (CHOP), caspase‑3 activity and apoptosis; while overexpression of TXNDC5 largely eliminated cetuximab‑induced levels of CHOP, caspase‑3 activity and apoptosis. Cisplatin and cetuximab demonstrated a combinatorial effect on increasing the levels of CHOP, caspase‑3 activity and apoptosis, which was largely eliminated by overexpression of TXNDC5 or a reactive oxygen species (ROS) scavenger/antagonist. In addition, promoter/luciferase reporter assays revealed that cisplatin and cetuximab regulated the expression of TXNDC5 at the gene transcription/promoter level. In conclusion, the findings suggested that ER stress‑associated apoptosis is a major mechanism underlying the apoptotic effect of cisplatin and cetuximab on LSCC cells; cetuximab enhanced cisplatin‑induced ER stress‑associated apoptosis in LSCC cells largely by inhibiting the expression of TXNDC5 and thereby increasing ROS production

  13. Regorafenib induces extrinsic and intrinsic apoptosis through inhibition of ERK/NF-κB activation in hepatocellular carcinoma cells.

    Science.gov (United States)

    Tsai, Jai-Jen; Pan, Po-Jung; Hsu, Fei-Ting

    2017-02-01

    The aim of the present study was to investigate the role of NF-κB inactivation in regorafenib-induced apoptosis in human hepatocellular carcinoma SK-HEP-1 cells. SK-HEP-1 cells were treated with different concentrations of the NF-κB inhibitor 4-N-[2-(4-phenoxyphenyl)ethyl]quinazoline-4,6-diamine (QNZ) or regorafenib for different periods. The effects of QNZ and regorafenib on cell viability, expression of NF-κB-modulated anti-apoptotic proteins and apoptotic pathways were analyzed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, western blotting, DNA gel electrophoresis, flow cytometry and NF-κB reporter gene assay. Inhibitors of various kinases including AKT, c-Jun N-terminal kinase (JNK), P38 and extracellular signal-regulated kinase (ERK) were used to evaluate the mechanism of regorafenib-induced NF-κB inactivation. The results demonstrated that both QNZ and regorafenib significantly inhibited the expression of anti-apoptotic proteins and triggered extrinsic and intrinsic apoptosis. We also demonstrated that regorafenib inhibited NF-κB activation through ERK dephosphorylation. Taken all together, our findings indicate that regorafenib triggers extrinsic and intrinsic apoptosis through suppression of ERK/NF-κB activation in SK-HEP-1 cells.

  14. GSK-3β inhibition by lithium confers resistance to chemotherapy-induced apoptosis through the repression of CD95 (Fas/APO-1) expression

    International Nuclear Information System (INIS)

    Beurel, Eleonore; Kornprobst, Michel; Blivet-Van Eggelpoel, Marie-Jose; Ruiz-Ruiz, Carmen; Cadoret, Axelle; Capeau, Jacqueline; Desbois-Mouthon, Christele

    2004-01-01

    Lithium exerts neuroprotective actions that involve the inhibition of glycogen synthase kinase-3β (GSK-3β). Otherwise, recent studies suggest that sustained GSK-3β inhibition is a hallmark of tumorigenesis. In this context, the present study was undertaken to examine whether lithium modulated cancer cell sensitivity to apoptosis induced by chemotherapy agents. We observed that, in different human cancer cell lines, lithium significantly reduced etoposide- and camptothecin-induced apoptosis. In HepG2 cells, lithium repressed drug induction of CD95 expression and clustering at the cell surface as well as caspase-8 activation. Lithium acted through deregulation of GSK-3β signaling since (1) it provoked a rapid and sustained phosphorylation of GSK-3β on the inhibitory serine 9 residue; (2) the GSK-3β inhibitor SB-415286 mimicked lithium effects by repressing drug-induced apoptosis and CD95 membrane expression; and (3) lithium promoted the disruption of nuclear GSK-3β/p53 complexes. Moreover, the overexpression of an inactivated GSK-3β mutant counteracted the stimulatory effects of etoposide and camptothecin on a luciferase reporter plasmid driven by a p53-responsive sequence from the CD95 gene. In conclusion, we provide the first evidence that lithium confers resistance to apoptosis in cancer cells through GSK-3β inhibition and subsequent repression of CD95 gene expression. Our study also highlights the concerted action of GSK-3β and p53 on CD95 gene expression

  15. Bcl-2 prevents loss of mitochondria in CCCP-induced apoptosis

    International Nuclear Information System (INIS)

    Graaf, Aniek O. de; Heuvel, Lambert P. van den; Dijkman, Henry B.P.M.; Abreu, Ronney A. de; Birkenkamp, Kim U.; Witte, Theo de; Reijden, Bert A. van der; Smeitink, Jan A.M.; Jansen, Joop H.

    2004-01-01

    Bcl-2 family proteins regulate apoptosis at the level of mitochondria. To examine the mechanism of Bcl-2 function, we investigated the effects of the protonophore carbonyl cyanide m-chlorophenyl hydrazone (CCCP) on two hematopoietic cell lines and Bcl-2 overexpressing transfectants. CCCP directly interferes with mitochondrial function and induces apoptosis. We show that Bcl-2 inhibits apoptosis and that the antiapoptotic effect of Bcl-2 takes place upstream of caspase activation and nuclear changes associated with apoptosis, since these were markedly inhibited in cells overexpressing Bcl-2. Bcl-2 does not prevent the decrease in mitochondrial membrane potential nor the alterations in cellular ATP content induced by CCCP in FL5.12 and Jurkat cells. A higher number of mitochondria was observed in untreated Bcl-2 transfected cells compared to parental cells, as shown by electron microscopy. Exposure to CCCP induced a dramatic decrease in the number of mitochondria and severely disrupted mitochondrial ultrastructure, with apparent swelling and loss of cristae in parental cells. Bcl-2 clearly diminished the disruption of mitochondrial structure and preserved a higher number of mitochondria. These data suggest that CCCP induces apoptosis by structural disruption of mitochondria and that Bcl-2 prevents apoptosis and mitochondrial degeneration by preserving mitochondrial integrity

  16. Bcl-2 prevents loss of mitochondria in CCCP-induced apoptosis.

    Science.gov (United States)

    de Graaf, Aniek O; van den Heuvel, Lambert P; Dijkman, Henry B P M; de Abreu, Ronney A; Birkenkamp, Kim U; de Witte, Theo; van der Reijden, Bert A; Smeitink, Jan A M; Jansen, Joop H

    2004-10-01

    Bcl-2 family proteins regulate apoptosis at the level of mitochondria. To examine the mechanism of Bcl-2 function, we investigated the effects of the protonophore carbonyl cyanide m-chlorophenyl hydrazone (CCCP) on two hematopoietic cell lines and Bcl-2 overexpressing transfectants. CCCP directly interferes with mitochondrial function and induces apoptosis. We show that Bcl-2 inhibits apoptosis and that the antiapoptotic effect of Bcl-2 takes place upstream of caspase activation and nuclear changes associated with apoptosis, since these were markedly inhibited in cells overexpressing Bcl-2. Bcl-2 does not prevent the decrease in mitochondrial membrane potential nor the alterations in cellular ATP content induced by CCCP in FL5.12 and Jurkat cells. A higher number of mitochondria was observed in untreated Bcl-2 transfected cells compared to parental cells, as shown by electron microscopy. Exposure to CCCP induced a dramatic decrease in the number of mitochondria and severely disrupted mitochondrial ultrastructure, with apparent swelling and loss of cristae in parental cells. Bcl-2 clearly diminished the disruption of mitochondrial structure and preserved a higher number of mitochondria. These data suggest that CCCP induces apoptosis by structural disruption of mitochondria and that Bcl-2 prevents apoptosis and mitochondrial degeneration by preserving mitochondrial integrity.

  17. Inhibition of SH2-domain-containing inositol 5-phosphatase (SHIP2) ameliorates palmitate induced-apoptosis through regulating Akt/FOXO1 pathway and ROS production in HepG2 cells

    Energy Technology Data Exchange (ETDEWEB)

    Gorgani-Firuzjaee, Sattar [Department of Biochemistry, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran (Iran, Islamic Republic of); Adeli, Khosrow [Division of Clinical Biochemistry, The Hospital for Sick Children, University of Toronto, Toronto (Canada); Meshkani, Reza, E-mail: rmeshkani@tums.ac.ir [Department of Biochemistry, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran (Iran, Islamic Republic of)

    2015-08-21

    The serine–threonine kinase Akt regulates proliferation and survival by phosphorylating a network of protein substrates; however, the role of a negative regulator of the Akt pathway, the SH2-domain-containing inositol 5-phosphatase (SHIP2) in apoptosis of the hepatocytes, remains unknown. In the present study, we studied the molecular mechanisms linking SHIP2 expression to apoptosis using overexpression or suppression of SHIP2 gene in HepG2 cells exposed to palmitate (0.5 mM). Overexpression of the dominant negative mutant SHIP2 (SHIP2-DN) significantly reduced palmitate-induced apoptosis in HepG2 cells, as these cells had increased cell viability, decreased apoptotic cell death and reduced the activity of caspase-3, cytochrome c and poly (ADP-ribose) polymerase. Overexpression of the wild-type SHIP2 gene led to a massive apoptosis in HepG2 cells. The protection from palmitate-induced apoptosis by SHIP2 inhibition was accompanied by a decrease in the generation of reactive oxygen species (ROS). In addition, SHIP2 inhibition was accompanied by an increased Akt and FOXO-1 phosphorylation, whereas overexpression of the wild-type SHIP2 gene had the opposite effects. Taken together, these findings suggest that SHIP2 expression level is an important determinant of hepatic lipoapotosis and its inhibition can potentially be a target in treatment of hepatic lipoapoptosis in diabetic patients. - Highlights: • Lipoapoptosis is the major contributor to the development of NAFLD. • The PI3-K/Akt pathway regulates apoptosis in different cells. • The role of negative regulator of this pathway, SHIP2 in lipoapoptosis is unknown. • SHIP2 inhibition significantly reduces palmitate-induced apoptosis in HepG2 cells. • SHIP2 inhibition prevents palmitate induced-apoptosis by regulating Akt/FOXO1 pathway.

  18. Inhibition of SH2-domain-containing inositol 5-phosphatase (SHIP2) ameliorates palmitate induced-apoptosis through regulating Akt/FOXO1 pathway and ROS production in HepG2 cells

    International Nuclear Information System (INIS)

    Gorgani-Firuzjaee, Sattar; Adeli, Khosrow; Meshkani, Reza

    2015-01-01

    The serine–threonine kinase Akt regulates proliferation and survival by phosphorylating a network of protein substrates; however, the role of a negative regulator of the Akt pathway, the SH2-domain-containing inositol 5-phosphatase (SHIP2) in apoptosis of the hepatocytes, remains unknown. In the present study, we studied the molecular mechanisms linking SHIP2 expression to apoptosis using overexpression or suppression of SHIP2 gene in HepG2 cells exposed to palmitate (0.5 mM). Overexpression of the dominant negative mutant SHIP2 (SHIP2-DN) significantly reduced palmitate-induced apoptosis in HepG2 cells, as these cells had increased cell viability, decreased apoptotic cell death and reduced the activity of caspase-3, cytochrome c and poly (ADP-ribose) polymerase. Overexpression of the wild-type SHIP2 gene led to a massive apoptosis in HepG2 cells. The protection from palmitate-induced apoptosis by SHIP2 inhibition was accompanied by a decrease in the generation of reactive oxygen species (ROS). In addition, SHIP2 inhibition was accompanied by an increased Akt and FOXO-1 phosphorylation, whereas overexpression of the wild-type SHIP2 gene had the opposite effects. Taken together, these findings suggest that SHIP2 expression level is an important determinant of hepatic lipoapotosis and its inhibition can potentially be a target in treatment of hepatic lipoapoptosis in diabetic patients. - Highlights: • Lipoapoptosis is the major contributor to the development of NAFLD. • The PI3-K/Akt pathway regulates apoptosis in different cells. • The role of negative regulator of this pathway, SHIP2 in lipoapoptosis is unknown. • SHIP2 inhibition significantly reduces palmitate-induced apoptosis in HepG2 cells. • SHIP2 inhibition prevents palmitate induced-apoptosis by regulating Akt/FOXO1 pathway

  19. Ginsenoside Rb1 Protects Neonatal Rat Cardiomyocytes from Hypoxia/Ischemia Induced Apoptosis and Inhibits Activation of the Mitochondrial Apoptotic Pathway

    Directory of Open Access Journals (Sweden)

    Xu Yan

    2014-01-01

    Full Text Available Aim. To investigate the effect of Ginsenoside Rb1 (GS-Rb1 on hypoxia/ischemia (H/I injury in cardiomyocytes in vitro and the mitochondrial apoptotic pathway mediated mechanism. Methods. Neonatal rat cardiomyocytes (NRCMs for the H/I groups were kept in DMEM without glucose and serum, and were placed into a hypoxic jar for 24 h. GS-Rb1 at concentrations from 2.5 to 40 µM was given during hypoxic period for 24 h. NRCMs injury was determined by MTT and lactate dehydrogenase (LDH leakage assay. Cell apoptosis, ROS accumulation, and mitochondrial membrane potential (MMP were assessed by flow cytometry. Cytosolic translocation of mitochondrial cytochrome c and Bcl-2 family proteins were determined by Western blot. Caspase-3 and caspase-9 activities were determined by the assay kit. Results. GS-Rb1 significantly reduced cell death and LDH leakage induced by H/I. It also reduced H/I induced NRCMs apoptosis induced by H/I, in accordance with a minimal reactive oxygen species (ROS burst. Moreover, GS-Rb1 markedly decreased the translocation of cytochrome c from the mitochondria to the cytosol, increased the Bcl-2/ Bax ratio, and preserved mitochondrial transmembrane potential (ΔΨm. Its administration also inhibited activities of caspase-9 and caspase-3. Conclusion. Administration of GS-Rb1 during H/I in vitro is involved in cardioprotection by inhibiting apoptosis, which may be due to inhibition of the mitochondrial apoptotic pathway.

  20. Curcumin induces apoptosis and inhibits prostaglandin E(2) production in synovial fibroblasts of patients with rheumatoid arthritis.

    Science.gov (United States)

    Park, Cheol; Moon, Dong-Oh; Choi, Il-Whan; Choi, Byung Tae; Nam, Taek-Jeong; Rhu, Chung-Ho; Kwon, Taeg Kyu; Lee, Won Ho; Kim, Gi-Young; Choi, Yung Hyun

    2007-09-01

    Rheumatoid arthritis (RA) is a chronic inflammatory disease that is characterized by hyperplasia of the synovial fibroblasts, which is partly the result of decreased apoptosis. This study investigated the mechanisms through which curcumin, a polyphenolic compound from the rhizome of Curcuma longa, exerts its anti-proliferative action in the synovial fibroblasts obtained from patients with RA. Exposure of the synovial fibroblasts to curcumin resulted in growth inhibition and the induction of apoptosis, as measured by MTT assay, fluorescent microscopy and Annexin-V-based assay. RT-PCR and immunoblotting showed that treating the cells with curcumin resulted in the down-regulation of anti-apoptotic Bcl-2 and the X-linked inhibitor of the apoptosis protein as well as the up-regulation of pro-apoptotic Bax expression in a concentration-dependent manner. Curcumin-induced apoptosis was also associated with the proteolytic activation of caspase-3 and caspase-9, and the concomitant degradation of poly(ADP-ribose) polymerase protein. Furthermore, curcumin decreased the expression levels of the cyclooxygenase (COX)-2 mRNA and protein without causing significant changes in the COX-1 levels, which was correlated with the inhibition of prostaglandin E(2) synthesis. These results show that curcumin might help identify a new therapeutic pathway against hyperplasia of the synovial fibroblasts in RA.

  1. Kinetics of radiation-induced apoptosis in neonatal urogenital tissues with and without protein synthesis inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Gobe, G.C.; Harmon, B.; Schoch, E.; Allan, D.J. [Queensland Univ., St. Lucia, QLD (Australia). Dept. of Chemistry

    1996-12-31

    The difference in incidence of radiation-induced apoptosis between two neonatal urogenital tissues, kidney and testis, was analysed over a 24h period. Concurrent administration of cycloheximide (10mg/kg body weight), a protein synthesis inhibitor, with radiation treatment was used to determine whether new protein synthesis had a role in induction of apoptosis in this in vivo model. Many chemotherapeutic drugs act via protein synthesis inhibition, and we believe that the results of this latter analysis may provide information for the planning of concurrent radio and chemotherapy. Apoptosis was quantified using morphological parameters, and verified by DNA gel electrophoresis for the typical banding pattern, and by electron microscopy. The proliferative index in tissues was studied, using [6-{sup 3}H]-thymidine uptake ( 1h prior to euthanasia and collection of tissues) and autoradiography as indicators of cell proliferation (S-phase). Tissue was collected 2, 4, 6, 8, and 24h after radiation treatment. Expression of one of the apoptosis-associated genes, Bcl-2 (an apoptosis inhibitor/cell survival gene), was studied using immunohistochemistry. Apoptosis peaked at 4h in the testis and 6h in the kidney, emphasising the necessity of knowing tissue differences in radiation response if comparing changes at a particular time. A higher proportion (almost five fold) of the apoptotic cells died in S-phase in the kidney than the testis, over the 24h. Protein synthesis inhibition completely negated induction of apoptosis in both tissues. Necrosis was not identified at any time. Cycloheximide treatment greatly diminished Bcl-2 expression. The differences in response of the two tissues to irradiation relates to their innate cell (genetic) controls, which may be determined by their state of differentiation at time of treatment, or the tissue type. This in vivo study also suggests the model may be useful for analysis of other cancer therapies for example polychemotherapies or chemo

  2. Protection of betulin against cadmium-induced apoptosis in hepatoma cells

    International Nuclear Information System (INIS)

    Oh, Seon-Hee; Choi, Jeong-Eun; Lim, Sung-Chul

    2006-01-01

    The protective effects of betulin (BT) against cadmium (Cd)-induced cytotoxicity have been previously reported. However, the mechanisms responsible for these protective effects are unclear. Therefore, this study investigated the mechanisms responsible for the protection of BT against Cd-induced cytotoxicity in human hepatoma cell lines. The protection of BT against Cd cytotoxicity was more effective in the HepG2 than in the Hep3B cells. The protection of BT on Cd-induced cytotoxicity in the HepG2 cells appeared to be related to the inhibition of apoptosis, as determined by PI staining and DNA fragmentation analysis. The anti-apoptosis exerted by BT involved the blocking of Cd-induced reactive oxygen species (ROS) generation, the abrogation of the Cd-induced Fas upregulation, the blocking of caspase-8-dependent Bid activation, and subsequent inhibition of mitochondrial pathway. The BT pretreatment did not affect the p21 and p53 expression levels, when compared with those of the treated cells with Cd alone. BT induced the transient S phase arrest at an early stage and the G /G 1 arrest at a relatively late stage, but it did not observe the sub-G1 apoptotic peak. In the Hep3B cells, Cd did not induce ROS generation. The BT pretreatment partially inhibited the Cd-induced apoptosis, which was related with the incomplete blockage in caspase-9 or -3 activation, as well as in Bax activation. Taken together, it was found that Cd can induce apoptosis via the Fas-dependent and -independent apoptosis pathways. However, the observed protective effects of BT were clearly more sensitive to Fas-expressing HepG2 cells than to Fas-deficient Hep3B cells

  3. Inhibitory Effect of Lycopene on Amyloid-β-Induced Apoptosis in Neuronal Cells.

    Science.gov (United States)

    Hwang, Sinwoo; Lim, Joo Weon; Kim, Hyeyoung

    2017-08-16

    Alzheimer's disease (AD) is a fatal neurodegenerative disease. Brain amyloid-β deposition is a crucial feature of AD, causing neuronal cell death by inducing oxidative damage. Reactive oxygen species (ROS) activate NF-κB, which induces expression of Nucling. Nucling is a pro-apoptotic factor recruiting the apoptosome complex. Lycopene is an antioxidant protecting from oxidative stress-induced cell damage. We investigated whether lycopene inhibits amyloid-β-stimulated apoptosis through reducing ROS and inhibiting mitochondrial dysfunction and NF-κB-mediated Nucling expression in neuronal SH-SY5Y cells. We prepared cells transfected with siRNA for Nucling or nontargeting control siRNA to determine the role of Nucling in amyloid-β-induced apoptosis. The amyloid-β increased intracellular and mitochondrial ROS levels, apoptotic indices (p53, Bax/Bcl-2 ratio, caspase-3 cleavage), NF-kB activation and Nucling expression, while cell viability, mitochondrial membrane potential, and oxygen consumption rate decreased in SH-SY5Y cells. Lycopene inhibited these amyloid-β-induced alterations. However, amyloid-β did not induce apoptosis, determined by cell viability and apoptotic indices (p53, Bax/Bcl-2 ratio, caspase-3 cleavage), in the cells transfected with siRNA for Nucling. Lycopene inhibited apoptosis by reducing ROS, and by inhibiting mitochondrial dysfunction and NF-κB-target gene Nucling expression in neuronal cells. Lycopene may be beneficial for preventing oxidative stress-mediated neuronal death in patients with neurodegeneration.

  4. Inhibition of VDAC1 prevents Ca²⁺-mediated oxidative stress and apoptosis induced by 5-aminolevulinic acid mediated sonodynamic therapy in THP-1 macrophages.

    Science.gov (United States)

    Chen, Haibo; Gao, Weiwei; Yang, Yang; Guo, Shuyuan; Wang, Huan; Wang, Wei; Zhang, Shuisheng; Zhou, Qi; Xu, Haobo; Yao, Jianting; Tian, Zhen; Li, Bicheng; Cao, Wenwu; Zhang, Zhiguo; Tian, Ye

    2014-12-01

    Ultrasound combined with endogenous protoporphyrin IX derived from 5-aminolevulinic acid (ALA-SDT) is known to induce apoptosis in multiple cancer cells and macrophages. Persistent retention of macrophages in the plaque has been implicated in the pathophysiology and progression of atherosclerosis. Here we investigated the effects of inhibition of voltage-dependent anion channel 1 (VDAC1) on ALA-SDT-induced THP-1 macrophages apoptosis. Cells were pre-treated with VDAC1 inhibitor 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS) disodium salt for 1 h or downregulated VDAC1 expression by small interfering RNA and exposed to ultrasound. Cell viability was assessed by MTT assay, and cell apoptosis along with necrosis was evaluated by Hoechst 33342/propidium iodide staining and flow cytometry. Levels of cytochrome c release was assessed by confocal microscope and Western blot. The levels of full length caspases, caspase activation, and VDAC isoforms were analyzed by Western blot. Intracellular reactive oxygen species generation, mitochondrial membrane permeability, and intracellular Ca(2+) [Ca(2+)]i levels were measured with fluorescent probes. We confirmed that the pharmacological inhibition of VDAC1 by DIDS notably prevented ALA-SDT-induced cell apoptosis in THP-1 macrophages. Additionally, DIDS significantly inhibited intracellular ROS generation and apoptotic biochemical changes such as inner mitochondrial membrane permeabilization, loss of mitochondrial membrane potential, cytochrome c release and activation of caspase-3 and caspase-9. Moreover, ALA-SDT elevated the [Ca(2+)]i levels and it was also notably reduced by DIDS. Furthermore, both of intracellular ROS generation and cell apoptosis were predominately inhibited by Ca(2+) chelating reagent BAPTA-AM. Intriguingly, ALA-treatment markedly augmented VDAC1 protein levels exclusively, and the downregulation of VDAC1 expression by specific siRNA also significantly abolished cell apoptosis. Altogether, these

  5. TNF/TNFR{sub 1} pathway and endoplasmic reticulum stress are involved in ofloxacin-induced apoptosis of juvenile canine chondrocytes

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Fu-Tao; Ding, Yi; Shah, Zahir; Xing, Dan; Gao, Yuan; Liu, Dong Ming; Ding, Ming-Xing, E-mail: dmx@mail.hzau.edu.cn

    2014-04-15

    Background and purpose: Quinolones cause obvious cartilaginous lesions in juvenile animals by chondrocyte apoptosis, which results in the restriction of their use in pediatric and adolescent patients. Studies showed that chondrocytes can be induced to produce TNFα, and the cisternae of the endoplasmic reticulum in quinolone-treated chondrocytes become dilated. We investigated whether TNF/TNFR{sub 1} pathway and endoplasmic reticulum stress (ERs) are involved in ofloxacin (a typical quinolone)-induced apoptosis of juvenile canine chondrocytes. Experimental approach: Canine juvenile chondrocytes were treated with ofloxacin. Cell survival and apoptosis rates were determined with MTT method and flow cytometry, respectively. The gene expression levels of the related signaling molecules (TNFα, TNFR{sub 1}, TRADD, FADD and caspase-8) in death receptor pathways and main apoptosis-related molecules (calpain, caspase-12, GADD153 and GRP78) in ERs were measured by qRT-PCR. The gene expression of TNFR{sub 1} was suppressed with its siRNA. The protein levels of TNFα, TNFR{sub 1} and caspase-12 were assayed using Western blotting. Key results: The survival rates decreased while apoptosis rates increased after the chondrocytes were treated with ofloxacin. The mRNA levels of the measured apoptosis-related molecules in death receptor pathways and ERs, and the protein levels of TNFα, TNFR{sub 1} and caspase-12 increased after the chondrocytes were exposed to ofloxacin. The downregulated mRNA expressions of TNFR{sub 1}, Caspase-8 and TRADD, and the decreased apoptosis rates of the ofloxacin-treated chondrocytes occurred after TNFR{sub 1}–siRNA interference. Conclusions and implications: Ofloxacin-induced chondrocyte apoptosis in a time- and concentration-dependent fashion. TNF/TNFR{sub 1} pathway and ERs are involved in ofloxacin-induced apoptosis of juvenile canine chondrocytes in the early stage. - Highlights: • Chondrocyte apoptosis is induced by ofloxacin in a time- and

  6. Resolvin D1 Protects Lipopolysaccharide-induced Acute Kidney Injury by Down-regulating Nuclear Factor-kappa B Signal and Inhibiting Apoptosis

    Directory of Open Access Journals (Sweden)

    Yu-Liang Zhao

    2016-01-01

    Conclusion: In LPS-induced AKI, RvD1 could decrease TNF-α level, ameliorate kidney pathological injury, protect kidney function, and improve animal survival by down-regulating NF-κB inflammatory signal as well as inhibiting renal cell apoptosis.

  7. Chloroquinone Inhibits Cell Proliferation and Induces Apoptosis in ...

    African Journals Online (AJOL)

    Purpose: To demonstrate the role of chloroquinone (CQ) in inducing apoptosis in HONE-1 and HNE-1, nasopharyngeal carcinoma (NPC) cell lines. Methods: Water-soluble tetrazolium salt (WST)-1 assay was used for the determination of cell proliferation while an inverted microscope was employed for the analysis of ...

  8. Inhibition of phospholipaseD2 increases hypoxia-induced human colon cancer cell apoptosis through inactivating of the PI3K/AKT signaling pathway.

    Science.gov (United States)

    Liu, Maoxi; Fu, Zhongxue; Wu, Xingye; Du, Kunli; Zhang, Shouru; Zeng, Li

    2016-05-01

    Hypoxia is a common feature of solid tumor, and is a direct stress that triggers apoptosis in many human cell types. As one of solid cancer, hypoxia exists in the whole course of colon cancer occurrence and progression. Our previous studies shown that hypoxia induce high expression of phospholipase D2 (PLD2) and survivin in colon cancer cells. However, the correlation between PLD2 and survivin in hypoxic colon cancer cells remains unknown. In this study, we observed significantly elevated PLD2 and survivin expression levels in colon cancer tissues and cells. This is a positive correlation between of them, and co-expression of PLD2 and survivin has a positive correlation with the clinicpatholic features including tumor size, TNM stage, and lymph node metastasis. We also found that hypoxia induced the activity of PLD increased significant mainly caused by PLD2 in colon cancer cells. However, inhibition the activity of PLD2 induced by hypoxia promotes the apoptosis of human colon cancer cells, as well as decreased the expression of apoptosis markers including survivin and bcl2. Moreover, the pharmacological inhibition of PI3K/AKT supported the hypothesis that promotes the apoptosis of hypoxic colon cancer cells by PLD2 activity inhibition may through inactivation of the PI3K/AKT signaling pathway. Furthermore, interference the PLD2 gene expression leaded to the apoptosis of hypoxic colon cancer cells increased and also decreased the expression level of survivin and bcl2 may through inactivation of PI3K/AKT signaling pathway. These results indicated that PLD2 play antiapoptotic role in colon cancer under hypoxic conditions, inhibition of the activity, or interference of PLD2 gene expression will benefit for the treatment of colon cancer patients.

  9. Calpain Zymography: General Methodology and Protocol.

    Science.gov (United States)

    Wang, Kevin K W

    2017-01-01

    Casein zymography has become one of the gold standard assays for monitoring mammalian calcium-activated proteases (calpains) in purified enzyme, cell, or tissue samples. This calpain zymography method takes advantages of (1) casein is an excellent substrate for major isoforms of calpains (Calpain-1, 2 and 3), (2) the embedded casein is digested into small peptides where the calpain bands are located, thus creating a clear zone upon Commassie blue gel staining, and (3) the calpain isoforms have different gel mobility under native gel conditions. Casein zymography is also useful in studying reversibility of inhibitor binding to calpains.

  10. Fisetin inhibits cellular proliferation and induces mitochondria-dependent apoptosis in human gastric cancer cells.

    Science.gov (United States)

    Sabarwal, Akash; Agarwal, Rajesh; Singh, Rana P

    2017-02-01

    The anticancer effects of fisetin, a dietary agent, are largely unknown against human gastric cancer. Herein, we investigated the mechanisms of fisetin-induced inhibition of growth and survival of human gastric carcinoma AGS and SNU-1 cells. Fisetin (25-100 μM) caused significant decrease in the levels of G1 phase cyclins and CDKs, and increased the levels of p53 and its S15 phosphorylation in gastric cancer cells. We also observed that growth suppression and death of non-neoplastic human intestinal FHs74int cells were minimally affected by fisetin. Fisetin strongly increased apoptotic cells and showed mitochondrial membrane depolarization in gastric cancer cells. DNA damage was observed as early as 3 h after fisetin treatment which was accompanied with gamma-H2A.X(S139) phosphorylation and cleavage of PARP. Fisetin-induced apoptosis was observed to be independent of p53. DCFDA and MitoSOX analyses showed an increase in mitochondrial ROS generation in time- and dose-dependent fashion. It also increased cellular nitrite and superoxide generation. Pre-treatment with N-acetyl cysteine (NAC) inhibited ROS generation and also caused protection from fisetin-induced DNA damage. The formation of comets were observed in only fisetin treated cells which was blocked by NAC pre-treatment. Further investigation of the source of ROS, using mitochondrial respiratory chain (MRC) complex inhibitors, suggested that fisetin caused ROS generation specifically through complex I. Collectively, these results for the first time demonstrated that fisetin possesses anticancer potential through ROS production most likely via MRC complex I leading to apoptosis in human gastric carcinoma cells. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  11. Inhibitory heterotrimeric GTP-binding proteins inhibit hydrogen peroxide-induced apoptosis by up-regulation of Bcl-2 via NF-κB in H1299 human lung cancer cells

    International Nuclear Information System (INIS)

    Seo, Mi Ran; Nam, Hyo-Jung; Kim, So-Young; Juhnn, Yong-Sung

    2009-01-01

    Inhibitory heterotrimeric GTP-binding proteins (Gi proteins) mediate a variety of signaling pathways by coupling receptors and effectors to regulate cellular proliferation, differentiation, and apoptosis. However, the role of Gi proteins in the modulation of hydrogen peroxide-induced apoptosis is not clearly understood. Thus, we investigated the effect of Gi proteins on hydrogen peroxide-induced apoptosis and the underlying mechanisms in H1299 human lung cancer cells. The stable expression of constitutively active alpha subunits of Gi1 (Gαi1QL), Gi2, or Gi3 inhibited hydrogen peroxide-induced apoptosis. The expression of Gαi1QL up-regulated Bcl-2 expression, and the knockdown of Bcl-2 with siRNA abolished the anti-apoptotic effect of Gαi1QL. Gαi1 induced the transcription of Bcl-2 by activation of NF-κB, which resulted from an increase in NF-κB p50 protein. We conclude that Gαi1 inhibits hydrogen peroxide-induced apoptosis of H1299 lung cancer cells by up-regulating the transcription of Bcl-2 through a p50-mediated NF-κB activation.

  12. The effects of 3,4-methylenedioxymethamphetamine (MDMA) on nicotinic receptors: Intracellular calcium increase, calpain/caspase 3 activation, and functional upregulation

    International Nuclear Information System (INIS)

    Garcia-Rates, Sara; Camarasa, Jordi; Sanchez-Garcia, Ana I.; Gandia, Luis; Escubedo, Elena; Pubill, David

    2010-01-01

    Previous work by our group demonstrated that homomeric α7 nicotinic acetylcholine receptors (nAChR) play a role in the neurotoxicity induced by 3,4-methylenedioxymethamphetamine (MDMA), as well as the binding affinity of this drug to these receptors. Here we studied the effect of MDMA on the activation of nAChR subtypes, the consequent calcium mobilization, and calpain/caspase 3 activation because prolonged Ca 2+ increase could contribute to cytotoxicity. As techniques, we used fluorimetry in Fluo-4-loaded PC12 cells and electrophysiology in Xenopus oocytes. MDMA produced a rapid and sustained increase in calcium without reaching the maximum effect induced by ACh. It also concentration-dependently inhibited the response induced by ACh, nicotine, and the specific α7 agonist PNU 282987 with IC 50 values in the low micromolar range. Similarly, MDMA induced inward currents in Xenopus oocytes transfected with human α7 but not with α4β2 nAChR and inhibited ACh-induced currents in both receptors in a concentration-dependent manner. The calcium response was inhibited by methyllycaconitine (MLA) and α-bungarotoxin but not by dihydro-β-erythroidine. These results therefore indicate that MDMA acts as a partial agonist on α7 nAChRs and as an antagonist on the heteromeric subtypes. Subsequently, calcium-induced Ca 2+ release from the endoplasmic reticulum and entry through voltage-operated calcium channels are also implicated as proved using specific antagonists. In addition, treatment with MDMA for 24 h significantly increased basal Ca 2+ levels and induced an increase in α-spectrin breakdown products, which indicates that calpain and caspase 3 were activated. These effects were inhibited by pretreatment with MLA. Moreover, pretreatment with MDMA induced functional upregulation of calcium responses to specific agonists of both heteromeric and α7 nAChR. Sustained calcium entry and calpain activation could favor the activation of Ca 2+ -dependent enzymes such as

  13. Autophagy inhibition enhances apigenin-induced apoptosis in human breast cancer cells

    Institute of Scientific and Technical Information of China (English)

    Xuchen Cao; Bowen Liu; Wenfeng Cao; Weiran Zhang; Fei Zhang; Hongmeng Zhao; Ran Meng

    2013-01-01

    Apigenin (4',5,7-trihydroxyflavone) is a member of the flavone subclass of flavonoids present in fruits and vegetables.The involvement of autophagy in the apigenin-induced apoptotic death of human breast cancer cells was investigated.Cell proliferation and viability were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and clonogenic assays.Flow cytometry,fluorescent staining and Western blot analysis were employed to detect apoptosis and autophagy,and the role of autophagy was assessed using autophagy inhibitors.Apigenin dose-and time-dependently repressed the proliferation and clonogenic survival of the human breast cancer T47D and MDA-MB-231 cell lines.The death of T47D and MDA-MB-231 cells was due to apoptosis associated with increased levels of Caspase3,PARP cleavage and Bax/Bcl-2 ratios.The results from flow cytometry and fluorescent staining also verified the occurrence of apoptosis.In addition,the apigenin-treated cells exhibited autophagy,as characterized by the appearance of autophagosomes under fluorescence microscopy and the accumulation of acidic vesicular organelles (AVOs)by flow cytometry.Furthermore,the results of the Western blot analysis revealed that the level of LC3-Ⅱ,the processed form of LC3-Ⅰ,was increased.Treatment with the autophagy inhibitor,3-methyladenine (3-MA),significantly enhanced the apoptosis induced by apigenin,which was accompanied by an increase in the level of PARP cleavage.Similar results were also confirmed by flow cytometry and fluorescence microscopy.These results indicate that apigenin has apoptosis-and autophagy-inducing effects in breast cancer cells.Autophagy plays a cyto-protective role in apigenin-induced apoptosis,and the combination of apigenin and an autophagy inhibitor may be a promising strategy for breast cancer control.

  14. Chloroquine inhibits autophagy and deteriorates the mitochondrial dysfunction and apoptosis in hypoxic rat neurons.

    Science.gov (United States)

    Li, Peng; Hao, Lei; Guo, Yan-Yan; Yang, Guang-Lu; Mei, Hua; Li, Xiao-Hua; Zhai, Qiong-Xiang

    2018-06-01

    Mitochondrial dysfunction (MD) and apoptosis in the neurons are associated with neonatal hypoxic-ischemic (HI) encephalopathy (HIE). The present study was to explore the influence of autophagy on the induction of MD and apoptosis in the neurons in a neonatal HIE rats and in hypoxia-treated neurons in vitro. Ten-day-old HI rat pups were sacrificed for brain pathological examination and immunohistochemical analysis. The induction of autophagy, apoptosis and MD were also determined in the neurons under hypoxia, with or without autophagy inhibitor, chloroquine (CQ) treatment. HI treatment caused atrophy and apoptosis of neurons, with a significantly increased levels of apoptosis- and autophagy-associated proteins, such as cleaved caspase 3 and the B subunit of autophagy-related microtubule-associated protein 1 light chain 3 (LC3-B). in vitro experiments demonstrated that the hypoxia induced autophagy in neurons, as was inhibited by CQ. The hypoxia-induced cytochrome c release, cleaved caspase 3 and cleaved caspase 9 were aggravated by CQ. Moreover, there were higher levels of reactive oxygen species, more mitochondrial superoxide and less mitochondrial membrane potential in the CQ-treated neurons under hypoxia than in the neurons singularly under hypoxia. Apoptosis and autophagy were induced in HI neonatal rat neurons, autophagy inhibition deteriorates the hypoxia-induced neuron MD and apoptosis. It implies a neuroprotection of autophagy in the hypoxic-ischemic encephalopathy. Administration of autophagy inducer agents might be promising in HIE treatment. Copyright © 2018. Published by Elsevier Inc.

  15. Kushenin induces the apoptosis of HCV-infected cells by blocking the PI3K-Akt-mTOR pathway via inhibiting NS5A

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Yi; Chen, Na; Liu, Xiaojing; Lin, Shumei [Department of Infectious Diseases, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi 710061 (China); Luo, Wenjuan, E-mail: wenjuanluoxa@163.com [School of Pharmacy, Xi’an Jiaotong University, Xi’an, Shaanxi 710061 (China); Liu, Min, E-mail: minliusx@163.com [Department of Infectious Diseases, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi 710061 (China)

    2016-07-01

    With the increased burden induced by HCV, there is an urgent need to develop better-tolerated agents with good safety. In this study, we evaluated the anti-HCV capability of kushenin, as well as the possible mechanism to Huh7.5-HCV cells. The results demonstrated that kushenin significantly inhibited the HCV-RNA level. Similarly, the expression of HCV-specific protein NS5A was also decreased. Molecular docking results displayed that kushenin bonded well to the active pockets of HCV NS5A, further confirming the effects of kushenin on HCV replication. Coimmunoprecipitation assay determined that kushenin suppressed the interaction between PI3K and NS5A in HCV-replicon cells. Furthermore, kushenin exerted an obviously induced function on HCV-replicon cells apoptosis by inhibiting PI3K-Akt-mTOR pathway, which could be ameliorated by the specific activator IGF-1 addition. Taken together, kushenin possesses the ability to inhibit HCV replication, and contributes to the increased apoptosis of HCV-infected cells by blocking the PI3K-Akt-mTOR pathway via inhibiting NS5A. Our results provide important evidence for a better understanding of the pathogenesis of HCV infection, and suggest that kushenin has the potential to treat HCV disease. - Highlights: • Kushenin inhibits HCV replication. • Kushenin bonds directly to NS5A protein. • Kushenin induces the apoptosis of HCV-infected cells. • kushenin suppresses the interaction between PI3K and NS5A. • Kushenin inhibits PI3K-Akt-mTOR pathway.

  16. Kushenin induces the apoptosis of HCV-infected cells by blocking the PI3K-Akt-mTOR pathway via inhibiting NS5A

    International Nuclear Information System (INIS)

    Zhou, Yi; Chen, Na; Liu, Xiaojing; Lin, Shumei; Luo, Wenjuan; Liu, Min

    2016-01-01

    With the increased burden induced by HCV, there is an urgent need to develop better-tolerated agents with good safety. In this study, we evaluated the anti-HCV capability of kushenin, as well as the possible mechanism to Huh7.5-HCV cells. The results demonstrated that kushenin significantly inhibited the HCV-RNA level. Similarly, the expression of HCV-specific protein NS5A was also decreased. Molecular docking results displayed that kushenin bonded well to the active pockets of HCV NS5A, further confirming the effects of kushenin on HCV replication. Coimmunoprecipitation assay determined that kushenin suppressed the interaction between PI3K and NS5A in HCV-replicon cells. Furthermore, kushenin exerted an obviously induced function on HCV-replicon cells apoptosis by inhibiting PI3K-Akt-mTOR pathway, which could be ameliorated by the specific activator IGF-1 addition. Taken together, kushenin possesses the ability to inhibit HCV replication, and contributes to the increased apoptosis of HCV-infected cells by blocking the PI3K-Akt-mTOR pathway via inhibiting NS5A. Our results provide important evidence for a better understanding of the pathogenesis of HCV infection, and suggest that kushenin has the potential to treat HCV disease. - Highlights: • Kushenin inhibits HCV replication. • Kushenin bonds directly to NS5A protein. • Kushenin induces the apoptosis of HCV-infected cells. • kushenin suppresses the interaction between PI3K and NS5A. • Kushenin inhibits PI3K-Akt-mTOR pathway.

  17. Autophagy Inhibition Enhances the Mitochondrial-Mediated Apoptosis Induced by Mangrove (Avicennia marina) Extract in Human Breast Cancer Cells

    KAUST Repository

    Esau, Luke

    2015-01-10

    Aims: Avicennia marina (AM) is a widely distributed mangrove plant that has been used in traditional medicine for centuries for the treatment of a number of diseases. The objective of the present study was to evaluate the leaf ethyl acetate extract of AM for its cytotoxic and apoptotic potential along with in-depth investigations of its mechanism of action in breast cancer MCF-7 cells. Study Design: The ethyl acetate extract of leaves and stems of AM was tested against estrogen positive breast cancer cell line MCF-7 using various assays. Place and Duration of Study: The study was carried out at King Abdullah University of Science and Technology, Thuwal, Saudi Arabia, from July 2013-June 2014. Methodology: Dose- and time-dependent growth inhibition of cancer cells was measured using MTT assay. The mechanisms of apoptosis induction were determined using various assays: phosphatidylserine exposure, caspase-3/7 activation, mitochondrial membrane potential disruption, reactive oxygen species (ROS) production, cell cycle analysis, autophagy, and protein expression using western blotting. The modulation of apoptotic genes (p53, Mdm2, NF-kB, Bad, Bax, Bcl-2 and Casp7) was also determined using real time PCR. Results: The AM extract inhibited breast cancer cell growth and induced apoptosis in a concentration dependent manner. We demonstrated a non-classical mode of apoptosis induction in MCF-7 cells by AM extract, where ROS production altered the mitochondrial membrane potential to induce apoptosis. Breast cancer cells treated with 200 µg/ml concentration of AM extract showed increased ROS production and disrupted MMP but no PARP-1 cleavage and a marked decrease in Caspase-7 protein levels (24 and 48 h) were detected. A significant amount of autophagy was also observed at the same concentration. However, treatment of MCF-7 cells with 200 µg/ml of AM extract along with the inhibition of autophagy by chloroquine, significantly increased the apoptosis from 20% to 45

  18. miR-34a expands myeloid-derived suppressor cells via apoptosis inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Anfei, E-mail: huang_anfei@163.com [Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, Jiangsu Province (China); Zhang, Haitao, E-mail: zhanghtjp@126.com [Department of General Surgery, The First Affiliated Hospital of Soochow University, Suzhou 215021, Jiangsu Province (China); Chen, Si, E-mail: chensisdyxb@126.com [Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, Jiangsu Province (China); Xia, Fei, E-mail: xiafei87@gmail.com [Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, Jiangsu Province (China); Yang, Yi, E-mail: 602744364@qq.com [Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, Jiangsu Province (China); Dong, Fulu, E-mail: adiok0903@126.com [Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, Jiangsu Province (China); Sun, Di, E-mail: dongfl@suda.edu.cn [Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, Jiangsu Province (China); Xiong, Sidong, E-mail: sdxiong@suda.edu.cn [Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, Jiangsu Province (China); Zhang, Jinping, E-mail: j_pzhang@suda.edu.cn [Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, Jiangsu Province (China)

    2014-08-15

    Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population and show significant expansion under pathological conditions. microRNA plays important roles in many biological processes, whether microRNAs have a function in the expansion of MDSCs is still not very clear. In this study, miR-34a overexpression can induce the expansion of MDSCs in bone marrow chimera and transgenic mice model. The experimental results suggest that miR-34a inhibited the apoptosis of MDSCs but did not affect the proliferation of MDSCs. The distinct mRNA microarray profiles of MDSCs of wild type and miR-34a over-expressing MDSCs combined with the target prediction of miR-34a suggest that miR-34a may target genes such as p2rx7, Tia1, and plekhf1 to inhibit the apoptosis of MDSCs. Taken together, miR-34a contributes to the expansion of MDSCs by inhibiting the apoptosis of MDSCs. - Highlights: • Over-expression of miR-34a increases the number of MDSCs. • miR-34a inhibits the apoptosis of MDSCs, but does not affects their proliferation. • miR-34a may inhibit the apoptosis of MDSCs via targeting the p2rx7, Tia1 and plekhf1.

  19. Isoorientin induces apoptosis through mitochondrial dysfunction and inhibition of PI3K/Akt signaling pathway in HepG2 cancer cells

    International Nuclear Information System (INIS)

    Yuan, Li; Wang, Jing; Xiao, Haifang; Xiao, Chunxia; Wang, Yutang; Liu, Xuebo

    2012-01-01

    Isoorientin (ISO) is a flavonoid compound that can be extracted from several plant species, such as Phyllostachys pubescens, Patrinia, and Drosophyllum lusitanicum; however, its biological activity remains poorly understood. The present study investigated the effects and putative mechanism of apoptosis induced by ISO in human hepatoblastoma cancer (HepG2) cells. The results showed that ISO induced cell death in a dose-dependent manner in HepG2 cells, but no toxicity in human liver cells (HL-7702) and buffalo rat liver cells (BRL-3A) treated with ISO at the indicated concentrations. ISO-induced cell death included apoptosis which characterized by the appearance of nuclear shrinkage, the cleavage of poly (ADP-ribose) polymerase (PARP) and DNA fragmentation. ISO significantly (p < 0.01) increased the Bax/Bcl-2 ratio, disrupted the mitochondrial membrane potential (MMP), increased the release of cytochrome c, activated caspase-3, and enhanced intracellular levels of reactive oxygen species (ROS) and nitric oxide (NO). In addition, ISO effectively inhibited the phosphorylation of Akt and increased FoxO4 expression. The PI3K/Akt inhibitor LY294002 enhanced the apoptosis-inducing effect of ISO. However, LY294002 markedly quenched ROS and NO generation and diminished the protein expression of heme peroxidase enzyme (HO-1) and inducible nitric oxide synthase (iNOS). Furthermore, the addition of a ROS inhibitor (N-acetyl cysteine, NAC) or iNOS inhibitor (N-[3-(aminomethyl) benzyl] acetamidine, dihydrochloride, 1400W) significantly diminished the apoptosis induced by ISO and also blocked the phosphorylation of Akt. These results demonstrated for the first time that ISO induces apoptosis in HepG2 cells and indicate that this apoptosis might be mediated through mitochondrial dysfunction and PI3K/Akt signaling pathway, and has no toxicity in normal liver cells, suggesting that ISO may have good potential as a therapeutic and chemopreventive agent for liver cancer. Highlights:

  20. SENP1 inhibition induces apoptosis and growth arrest of multiple myeloma cells through modulation of NF-κB signaling

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jun [Graduate School of Anhui Medical University, Hefei (China); Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing 100850 (China); Sun, Hui-Yan; Xiao, Feng-Jun; Wang, Hua [Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing 100850 (China); Yang, Yang [Department of Hematology, General Hospital of Air Force, Beijing (China); Wang, Lu; Gao, Chun-Ji [Department of Hematology, PLA General Hospital, Beijing (China); Guo, Zi-Kuan [Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing 100850 (China); Wu, Chu-Tse [Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing 100850 (China); Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, Chengdu (China); Wang, Li-Sheng, E-mail: Wangls@bmi.ac.cn [Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing 100850 (China); Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, Chengdu (China)

    2015-05-01

    SUMO/sentrin specific protease 1 (Senp1) is an important regulation protease in the protein sumoylation, which affects the cell cycle, proliferation and differentiation. The role of Senp1 mediated protein desumoylation in pathophysiological progression of multiple myeloma is unknown. In this study, we demonstrated that Senp1 is overexpressed and induced by IL-6 in multiple myeloma cells. Lentivirus-mediated Senp1 knockdown triggers apoptosis and reduces viability, proliferation and colony forming ability of MM cells. The NF-κB family members including P65 and inhibitor protein IkBα play important roles in regulation of MM cell survival and proliferation. We further demonstrated that Senp1 inhibition decreased IL-6-induced P65 and IkBα phosphorylation, leading to inactivation of NF-kB signaling in MM cells. These results delineate a key role for Senp1in IL-6 induced proliferation and survival of MM cells, suggesting it may be a potential new therapeutic target in MM. - Highlights: • Senp1 is overexpressed and induced by IL-6 in multiple myeloma cells. • Senp1 knockdown triggers apoptosis and reduces proliferation of MM cells. • Senp1 inhibition decreased IL-6-induced P65 and IkBα phosphorylation.

  1. SENP1 inhibition induces apoptosis and growth arrest of multiple myeloma cells through modulation of NF-κB signaling

    International Nuclear Information System (INIS)

    Xu, Jun; Sun, Hui-Yan; Xiao, Feng-Jun; Wang, Hua; Yang, Yang; Wang, Lu; Gao, Chun-Ji; Guo, Zi-Kuan; Wu, Chu-Tse; Wang, Li-Sheng

    2015-01-01

    SUMO/sentrin specific protease 1 (Senp1) is an important regulation protease in the protein sumoylation, which affects the cell cycle, proliferation and differentiation. The role of Senp1 mediated protein desumoylation in pathophysiological progression of multiple myeloma is unknown. In this study, we demonstrated that Senp1 is overexpressed and induced by IL-6 in multiple myeloma cells. Lentivirus-mediated Senp1 knockdown triggers apoptosis and reduces viability, proliferation and colony forming ability of MM cells. The NF-κB family members including P65 and inhibitor protein IkBα play important roles in regulation of MM cell survival and proliferation. We further demonstrated that Senp1 inhibition decreased IL-6-induced P65 and IkBα phosphorylation, leading to inactivation of NF-kB signaling in MM cells. These results delineate a key role for Senp1in IL-6 induced proliferation and survival of MM cells, suggesting it may be a potential new therapeutic target in MM. - Highlights: • Senp1 is overexpressed and induced by IL-6 in multiple myeloma cells. • Senp1 knockdown triggers apoptosis and reduces proliferation of MM cells. • Senp1 inhibition decreased IL-6-induced P65 and IkBα phosphorylation

  2. Ketamine-induced apoptosis in cultured rat cortical neurons

    International Nuclear Information System (INIS)

    Takadera, Tsuneo; Ishida, Akira; Ohyashiki, Takao

    2006-01-01

    Recent data suggest that anesthetic drugs cause neurodegeneration during development. Ketamine is frequently used in infants and toddlers for elective surgeries. The purpose of this study is to determine whether glycogen synthase kinase-3 (GSK-3) is involved in ketamine-induced apoptosis. Ketamine increased apoptotic cell death with morphological changes which were characterized by cell shrinkage, nuclear condensation or fragmentation. In addition, insulin growth factor-1 completely blocked the ketamine-induced apoptotic cell death. Ketamine decreased Akt phosphorylation. GSK-3 is known as a downstream target of Akt. The selective inhibitors of GSK-3 prevented the ketamine-induced apoptosis. Moreover, caspase-3 activation was accompanied by the ketamine-induced cell death and inhibited by the GSK-3 inhibitors. These results suggest that activation of GSK-3 is involved in ketamine-induced apoptosis in rat cortical neurons

  3. In Silico Affinity Profiling of Neuroactive Polyphenols for Post-Traumatic Calpain Inactivation: A Molecular Docking and Atomistic Simulation Sensitivity Analysis

    Directory of Open Access Journals (Sweden)

    Pradeep Kumar

    2014-12-01

    Full Text Available Calcium-activated nonlysosomal neutral proteases, calpains, are believed to be early mediators of neuronal damage associated with neuron death and axonal degeneration after traumatic neural injuries. In this study, a library of biologically active small molecular weight calpain inhibitors was used for model validation and inhibition site recognition. Subsequently, two natural neuroactive polyphenols, curcumin and quercetin, were tested for their sensitivity and activity towards calpain’s proteolytic sequence and compared with the known calpain inhibitors via detailed molecular mechanics (MM, molecular dynamics (MD, and docking simulations. The MM and MD energy profiles (SJA6017 < AK275 < AK295 < PD151746 < quercetin < leupeptin < PD150606 < curcumin < ALLN < ALLM < MDL-28170 < calpeptin and the docking analysis (AK275 < AK295 < PD151746 < ALLN < PD150606 < curcumin < leupeptin < quercetin < calpeptin < SJA6017 < MDL-28170 < ALLM demonstrated that polyphenols conferred comparable calpain inhibition profiling. The modeling paradigm used in this study provides the first detailed account of corroboration of enzyme inhibition efficacy of calpain inhibitors and the respective calpain–calpain inhibitor molecular complexes’ energetic landscape and in addition stimulates the polyphenol bioactive paradigm for post-SCI intervention with implications reaching to experimental in vitro, in cyto, and in vivo studies.

  4. Neuroprotective effects of ganoderma lucidum polysaccharides against oxidative stress-induced neuronal apoptosis

    Science.gov (United States)

    Sun, Xin-zhi; Liao, Ying; Li, Wei; Guo, Li-mei

    2017-01-01

    Ganoderma lucidum polysaccharides have protective effects against apoptosis in neurons exposed to ischemia/reperfusion injury, but the mechanisms are unclear. The goal of this study was to investigate the underlying mechanisms of the effects of ganoderma lucidum polysaccharides against oxidative stress-induced neuronal apoptosis. Hydrogen peroxide (H2O2) was used to induce apoptosis in cultured cerebellar granule cells. In these cells, ganoderma lucidum polysaccharides remarkably suppressed H2O2-induced apoptosis, decreased expression of caspase-3, Bax and Bim and increased that of Bcl-2. These findings suggested that ganoderma lucidum polysaccharides regulate expression of apoptosis-associated proteins, inhibit oxidative stress-induced neuronal apoptosis and, therefore, have significant neuroprotective effects. PMID:28761429

  5. Role of calpains in the injury-induced dysfunction and degeneration of the mammalian axon.

    Science.gov (United States)

    Ma, Marek

    2013-12-01

    Axonal injury and degeneration, whether primary or secondary, contribute to the morbidity and mortality seen in many acquired and inherited central nervous system (CNS) and peripheral nervous system (PNS) disorders, such as traumatic brain injury, spinal cord injury, cerebral ischemia, neurodegenerative diseases, and peripheral neuropathies. The calpain family of proteases has been mechanistically linked to the dysfunction and degeneration of axons. While the direct mechanisms by which transection, mechanical strain, ischemia, or complement activation trigger intra-axonal calpain activity are likely different, the downstream effects of unregulated calpain activity may be similar in seemingly disparate diseases. In this review, a brief examination of axonal structure is followed by a focused overview of the calpain family. Finally, the mechanisms by which calpains may disrupt the axonal cytoskeleton, transport, and specialized domains (axon initial segment, nodes, and terminals) are discussed. © 2013.

  6. Luteolin Inhibits Tumorigenesis and Induces Apoptosis of Non-Small Cell Lung Cancer Cells via Regulation of MicroRNA-34a-5p

    Directory of Open Access Journals (Sweden)

    Ze-Qun Jiang

    2018-02-01

    Full Text Available Luteolin (LTL exerts remarkable tumor suppressive activity on various types of cancers, including non-small cell lung cancer (NSCLC. However, it is not completely understood whether the mechanism of its action against NSCLC is related to microRNAs (miRNAs. In the present study, we investigated the anti-tumor effects of LTL on NSCLC in vitro and in vivo. The results revealed that LTL could inhibit cell proliferation and induce apoptosis in both A549 and H460 cells. In a H460 xenograft tumor model of nude mice, LTL significantly suppressed tumor growth, inhibited cell proliferation, and induced apoptosis. miRNA microarray and quantitative PCR (qPCR analysis indicated that miR-34a-5p was dramatically upregulated upon LTL treatment in tumor tissues. Furthermore, MDM4 was proved to be a direct target of miR-34a-5p by luciferase reporter gene assay. LTL treatment was associated with increased p53 and p21 protein expressions and decreased MDM4 protein expression in both NSCLC cells and tumor tissues. When miR-34a-5p was inhibited in vitro, the protein expressions of Bcl-2 and MDM4 were recovered, while that of p53, p21, and Bax were attenuated. Moreover, caspase-3 and caspase-9 activation induced by LHL treatment in vitro were also suppressed by miR-34a-5p inhibition. Overall, LTL could inhibit tumorigenesis and induce apoptosis of NSCLC cells by upregulation of miR-34a-5p via targeting MDM4. These findings provide novel insight into the molecular functions of LTL that suggest its potential as a therapeutic agent for human NSCLC.

  7. ACS6, a Hydrogen sulfide-donating derivative of sildenafil, inhibits homocysteine-induced apoptosis by preservation of mitochondrial function

    Directory of Open Access Journals (Sweden)

    Tang Xiao-Qing

    2011-08-01

    Full Text Available Abstract Background The hydrogen sulfide-releasing sildenafil, ACS6, has been demonstrated to inhibit superoxide formation through donating hydrogen sulfide (H2S. We have found that H2S antagonizes homocysteine-induced oxidative stress and neurotoxicity. The aim of the present study is to explore the protection of ACS6 against homocysteine-triggered cytotoxicity and apoptosis and the molecular mechanisms underlying in PC12 cells. Methods Cell viability was determined by Cell Counting Kit-8 assay. Cell apoptosis was observed using the chromatin dye Hoechst 33258 and analyzed by Flow Cytometry after propidium iodide staining. Mitochondrial membrane potential was monitored using the fluorescent dye Rh123. Intracellular reactive oxygen species were determined by oxidative conversion of cell permeable 2',7'-dichlorfluorescein-diacetate to fluorescent 2',7'-dichlorfluorescein. The expression of cleaved caspase-3 and bcl-2 and the accumulation of cytosolic cytochrome c were analyzed by Western blot. Results We show that ACS6 protects PC12 cells against cytotoxicity and apoptosis induced by homocysteine and blocks homocysteine-triggered cytochrome c release and caspase-3 activation. ACS6 treatment results in not only prevention of homocysteine-caused mitochondrial membrane potential (Δψ loss and reactive oxygen species (ROS overproduction but also reversal of Bcl-2 down-expression. Conclusions These results indicate that ACS6 protects PC12 cells against homocysteine-induced cytotoxicity and apoptosis by preservation of mitochondrial function though inhibiting both loss of Δψ and accumulation of ROS as well as modulating the expression of Bcl-2. Our study provides evidence both for a neuroprotective effect of ACS6 and for further evaluation of ACS6 as novel neuroprotectants for Alzheimer's disease associated with homocysteine.

  8. Radiation-induced apoptosis

    International Nuclear Information System (INIS)

    Ohyama, Harumi

    1995-01-01

    Apoptosis is an active process of gene-directed cellular self-destruction that can be induced in many cell types via numerous physiological and pathological stimuli. We found that interphasedeath of thymocytes is a typical apoptosis showing the characteristic features of apoptosis including cell shrinkage, chromatin condensation and DNA degradation. Moderate dose of radiation induces extensive apoptosis in rapidly proliferating cell population such as the epithelium of intestinal crypt. Recent reports indicate that the ultimate form of radiation-induced mitotic death in several cells is also apoptosis. One of the hallmarks of apoptosis is the enzymatic internucleosomal degradation of chromatin DNA. We identified an endonuclease responsible for the radiation-induced DNA degradation in rat thymocytes. The death-sparing effects of interrupting RNA and protein synthesis suggested a cell genetic program for apoptosis. Apoptosis of thymocytes initiated by DNA damage, such as radiation and radio mimetic substance, absolutely requires the protein of p53 cancer suppresser gene. The cell death induced by glucocorticoid, or aging, has no such requirement. Expression of oncogene bcl-2 rescues cells from the apoptosis. Massive apoptosis in radiosensitive cells induced by higher dose radiation may be fatal. It is suggested that selective apoptotic elimination of cells would play an important role for protection against carcinogenesis and malformation through removal of cells with unrepaired radiation-induced DNA damages. Data to evaluate the significance of apoptosis in the radiation risk are still poor. Further research should be done in order to clarify the roles of the cell death on the acute and late effects of irradiation. (author)

  9. [Over-expression of BDNF inhibits angiotensin II-induced apoptosis of cardiomyocytes in SD rats].

    Science.gov (United States)

    Cao, Jingli; Wu, Yingfeng; Liu, Geming; Li, Zhenlong

    2018-03-01

    Objective To investigate the role and molecular mechanism of brain-derived neurotrophic factor (BDNF) against the process of cardiomyocyte hypertrophy and apoptosis. Methods Cardiomyocyte hypertrophy were estabolished by angiotensin II (Ang II) in neonatal cardiomyocytes in vitro and incomplete ligature of abdominal aorta of SD rats in vivo. BDNF over-expressing recombinant vector pcDNA5-BDNF was transfected into cardiomyocytes by liposomes. Immunofluorescence staining was used to detect the effect of BDNF transfection on the surface area of myocardial cells. The effect of BDNF transfection on the apoptosis of cardiomyocytes was assayed by flow cytometry. Real-time fluorescent quantitative PCR was performed to detect the effect of over-expression of BDNF on the expressions of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) mRNAs in cardiomyocytes. Western blot assay was used to observe the changes of BDNF, ANP and BNP, calmodulin kinase 2 (CaMK2) and phosphorylated calmodulin kinase 2 (p-CaMK2), calcineurin (CaN), p-CaN, nuclear factor of activated T cells 3 (NFATC3) and p-NFATC3 protein expressions in the myocardial tissues and cardiomyocytes. Results The expression of BDNF protein increased significantly in cardiac hypertrophy animal and cell models in a time-dependent manner. Compared with the untransfected control cardiomyocytes, the surface area of cardiomyocytes, the rate of apoptosis, the levels of ANP and BNP mRNA and protein expression, the levels of p-CaMK2 and CaN protein in the BDNF over-expressed cardiomyocytes were remarkably reduced, while the level of p-NFATC3 protein rose significantly. Conclusion BDNF inhibits the apoptosis of cardiomyocytes induced by Ang II, and it plays the role by inhibiting CaMK2 and CaN signaling pathways.

  10. Inhibition of histone deacetylases 1 and 6 enhances cytarabine-induced apoptosis in pediatric acute myeloid leukemia cells.

    Science.gov (United States)

    Xu, Xuelian; Xie, Chengzhi; Edwards, Holly; Zhou, Hui; Buck, Steven A; Ge, Yubin

    2011-02-16

    Pediatric acute myeloid leukemia (AML) remains a challenging disease to treat even with intensified cytarabine-based chemotherapy. Histone deacetylases (HDACs) have been reported to be promising therapeutic targets for treating AML. However, HDAC family members that are involved in chemotherapy sensitivities remain unknown. In this study, we sought to identify members of the HDAC family that are involved in cytarabine sensitivities, and to select the optimal HDACI that is most efficacious when combined with cytarabine for treating children with AML. Expression profiles of classes I, II, and IV HDACs in 4 pediatric AML cell lines were determined by Western blotting. Inhibition of class I HDACs by different HDACIs was measured post immnunoprecipitation. Individual down-regulation of HDACs in pediatric AML cells was performed with lentiviral shRNA. The effects of cytarabine and HDACIs on apoptosis were determined by flow cytometry analysis. Treatments with structurally diverse HDACIs and HDAC shRNA knockdown experiments revealed that down-regulation of both HDACs 1 and 6 is critical in enhancing cytarabine-induced apoptosis in pediatric AML, at least partly mediated by Bim. However, down-regulation of HDAC2 may negatively impact cytarabine sensitivities in the disease. At clinically achievable concentrations, HDACIs that simultaneously inhibited both HDACs 1 and 6 showed the best anti-leukemic activities and significantly enhanced cytarabine-induced apoptosis. Our results further confirm that HDACs are bona fide therapeutic targets for treating pediatric AML and suggest that pan-HDACIs may be more beneficial than isoform-specific drugs.

  11. Induction of apoptosis by plumbagin through reactive oxygen species-mediated inhibition of topoisomerase II

    International Nuclear Information System (INIS)

    Kawiak, Anna; Piosik, Jacek; Stasilojc, Grzegorz; Gwizdek-Wisniewska, Anna; Marczak, Lukasz; Stobiecki, Maciej; Bigda, Jacek; Lojkowska, Ewa

    2007-01-01

    Reactive oxygen species (ROS) have been recognized as key molecules, which can selectively modify proteins and therefore regulate cellular signalling including apoptosis. Plumbagin, a naphthoquinone exhibiting antitumor activity, is known to generate ROS and has been found to inhibit the activity of topoisomerase II (Topo II) through the stabilization of the Topo II-DNA cleavable complex. The objective of this research was to clarify the role of ROS and Topo II inhibition in the induction of apoptosis mediated by plumbagin. As determined by the comet assay, plumbagin induced DNA cleavage in HL-60 cells, whereas in a cell line with reduced Topo II activity-HL-60/MX2, the level of DNA damage was significantly decreased. The onset of DNA strand break formation in HL-60 cells was delayed in comparison with the generation of intracellular ROS. In HL-60/MX2 cells, ROS were generated at a similar rate, whereas a significant reduction in the level of DNA damage was detected. The pretreatment of cells with N-acetylcysteine (NAC) attenuated plumbagin-induced DNA damage, pointing out to the involvement of ROS generation in cleavable complex formation. These results suggest that plumbagin-induced ROS does not directly damage DNA but requires the involvement of Topo II. Furthermore, experiments carried out using light spectroscopy indicated no direct interactions between plumbagin and DNA. The induction of apoptosis was significantly delayed in HL-60/MX2 cells indicating the involvement of Topo II inhibition in plumbagin-mediated apoptosis. Thus, these findings strongly suggest ROS-mediated inhibition of Topo II as an important mechanism contributing to the apoptosis-inducing properties of plumbagin

  12. Inhibition of Fatty Acid Synthesis Induces Apoptosis of Human Pancreatic Cancer Cells.

    Science.gov (United States)

    Nishi, Koji; Suzuki, Kenta; Sawamoto, Junpei; Tokizawa, Yuma; Iwase, Yumiko; Yumita, Nagahiko; Ikeda, Toshihiko

    2016-09-01

    Cancer cells tend to have a high requirement for lipids, including fatty acids, cholesterol and triglyceride, because of their rapid proliferative rate compared to normal cells. In this study, we investigated the effects of inhibition of lipid synthesis on the proliferation and viability of human pancreatic cancer cells. Of the inhibitors of lipid synthesis that were tested, 5-(tetradecyloxy)-2-furoic acid (TOFA), which is an inhibitor of acetyl-CoA carboxylase, and the fatty acid synthase (FAS) inhibitors cerulenin and irgasan, significantly suppressed the proliferation of MiaPaCa-2 and AsPC-1 cells. Treatment of MiaPaCa-2 cells with these inhibitors significantly increased the number of apoptotic cells. In addition, TOFA increased caspase-3 activity and induced cleavage of poly (ADP-ribose) polymerase in MiaPaCa-2 cells. Moreover, addition of palmitate to MiaPaCa-2 cells treated with TOFA rescued cells from apoptotic cell death. These results suggest that TOFA induces apoptosis via depletion of fatty acids and that, among the various aspects of lipid metabolism, inhibition of fatty acid synthesis may be a notable target for the treatment of human pancreatic cancer cells. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  13. Down-regulation of cellular FLICE-inhibitory protein (Long Form contributes to apoptosis induced by Hsp90 inhibition in human lung cancer cells

    Directory of Open Access Journals (Sweden)

    Wang Qilin

    2012-12-01

    Full Text Available Abstract Background Cellular FLICE-Inhibitory Protein (long form, c-FLIPL is a critical negative regulator of death receptor-mediated apoptosis. Overexpression of c-FLIPL has been reported in many cancer cell lines and is associated with chemoresistance. In contrast, down-regulation of c-FLIP may drive cancer cells into cellular apoptosis. This study aims to demonstrate that inhibition of the heat shock protein 90 (Hsp90 either by inhibitors geldanamycin/17-N-Allylamino-17-demethoxygeldanamycin (GA/17-AAG or siRNA technique in human lung cancer cells induces c-FLIPL degradation and cellular apoptosis through C-terminus of Hsp70-interacting protein (CHIP-mediated mechanisms. Methods Calu-1 and H157 cell lines (including H157-c-FLIPL overexpressing c-FLIPL and control cell H157-lacZ were treated with 17-AAG and the cell lysates were prepared to detect the given proteins by Western Blot and the cell survival was assayed by SRB assay. CHIP and Hsp90 α/β proteins were knocked down by siRNA technique. CHIP and c-FLIPL plasmids were transfected into cells and immunoprecipitation experiments were performed to testify the interactions between c-FLIPL, CHIP and Hsp90. Results c-FLIPL down-regulation induced by 17-AAG can be reversed with the proteasome inhibitor MG132, which suggested that c-FLIPL degradation is mediated by a ubiquitin-proteasome system. Inhibition of Hsp90α/β reduced c-FLIPL level, whereas knocking down CHIP expression with siRNA technique inhibited c-FLIPL degradation. Furthermore, c-FLIPL and CHIP were co-precipitated in the IP complexes. In addition, overexpression of c-FLIPL can rescue cancer cells from apoptosis. When 17-AAG was combined with an anti-cancer agent celecoxib(CCB, c-FLIPL level declined further and there was a higher degree of caspase activation. Conclusion We have elucidated c-FLIPL degradation contributes to apoptosis induced by Hsp90 inhibition, suggesting c-FLIP and Hsp90 may be the promising combined targets

  14. Oxidative stress inhibits adhesion and transendothelial migration, and induces apoptosis and senescence of induced pluripotent stem cells.

    Science.gov (United States)

    Wu, Yi; Zhang, Xueqing; Kang, Xueling; Li, Ning; Wang, Rong; Hu, Tiantian; Xiang, Meng; Wang, Xinhong; Yuan, Wenjun; Chen, Alex; Meng, Dan; Chen, Sifeng

    2013-09-01

    Oxidative stress caused by cellular accumulation of reactive oxygen species (ROS) is a major contributor to disease and cell death. However, how induced pluripotent stem cells (iPSC) respond to different levels of oxidative stress is largely unknown. Here, we investigated the effect of H2 O2 -induced oxidative stress on iPSC function in vitro. Mouse iPSC were treated with H2 O2 (25-100 μmol/L). IPSC adhesion, migration, viability, apoptosis and senescence were analysed. Expression of adhesion-related genes, stress defence genes, and osteoblast- and adipocyte-associated genes were determined by reverse transcription polymerase chain reaction. The present study found that H2 O2 (25-100 μmol/L) decreased iPSC adhesion to matrix proteins and endothelial cells, and downregulated gene expression levels of adhesion-related molecules, such as integrin alpha 7, cadherin 1 and 5, melanoma cell adhesion molecule, vascular cell adhesion molecule 1, and monocyte chemoattractant protein-1. H2 O2 (100 μmol/L) decreased iPSC viability and inhibited the capacity of iPSC migration and transendothelial migration. iPSC were sensitive to H2 O2 -induced G2/M arrest, senescence and apoptosis when exposed to H2 O2 at concentrations above 25 μmol/L. H2 O2 increased the expression of stress defence genes, including catalase, cytochrome B alpha, lactoperoxidase and thioredoxin domain containing 2. H2 O2 upregulated the expression of osteoblast- and adipocyte-associated genes in iPSC during their differentiation; however, short-term H2 O2 -induced oxidative stress did not affect the protein expression of the pluripotency markers, octamer-binding transcription factor 4 and sex-determining region Y-box 2. The present results suggest that iPSC are sensitive to H2 O2 toxicity, and inhibition of oxidative stress might be a strategy for improving their functions. © 2013 Wiley Publishing Asia Pty Ltd.

  15. Upregulation of PEDF expression by PARP inhibition contributes to the decrease in hyperglycemia-induced apoptosis in HUVECs

    International Nuclear Information System (INIS)

    Chen Haibing; Jia Weiping; Xu Xun; Fan Ying; Zhu Dongqing; Wu Haixiang; Xie Zhenggao; Zheng Zhi

    2008-01-01

    Poly(ADP-ribose)polymerase (PARP) inhibitors decrease angiogenesis through reducing vascular endothelium growth factor (VEGF) induced proliferation, migration, and tube formation of human umbilical vein endothelial cells (HUVECs). In contrast to VEGF, pigment epithelium-derived factor (PEDF) has been demonstrated to act as a strong endogenous inhibitor of angiogenesis. Here, we show that PARP inhibition with a specific inhibitor PJ-34 or specific PARP antisense oligonucleotide upregulates hyperglycemia-induced PEDF expression in HUVECs in a dose-dependent manner. This results in the retard of activation of p38 MAP kinase and the concomitant decrease in cell apoptosis. These results give the first direct demonstration that PEDF might represent a target for PARP inhibition treatment and the effects of PEDF on endothelial cells growth are context dependent

  16. Troxerutin Reduces Kidney Damage against BDE-47-Induced Apoptosis via Inhibiting NOX2 Activity and Increasing Nrf2 Activity

    Directory of Open Access Journals (Sweden)

    Qun Shan

    2017-01-01

    Full Text Available 2,2,4,4-Tetrabromodiphenyl ether (BDE-47, one of the persistent organic pollutants, seriously influences the quality of life; however, its pathological mechanism remains unclear. Troxerutin is a flavonoid with pharmacological activity of antioxidation and anti-inflammation. In the present study, we investigated troxerutin against BDE-47-induced kidney cell apoptosis and explored the underlying mechanism. The results show that troxerutin reduced renal cell apoptosis and urinary protein secretion in BDE-47-treated mice. Western blot analysis shows that troxerutin supplement enhanced the ratio of Bcl-2/Bax; inhibited the release of cytochrome c from mitochondria, the activation of procaspase-9 and procaspase-3, and the cleavage of PARP; and reduced FAS, FASL, and caspase-8 levels induced by BDE-47. In addition, troxerutin decreased the production of reactive oxygen species (ROS and increased the activities of antioxidative enzymes. Furthermore, troxerutin blunted Nrf2 ubiquitylation, enhanced the activity of Nrf2, decreased the activity of NOX2, and ameliorated kidney oxidant status of BDE-47-treated mice. Together, these results confirm that troxerutin could alleviate the cytotoxicity of BDE-47 through antioxidation and antiapoptosis, which suggests that its protective mechanism is involved in the inhibition of apoptosis via suppressing NOX2 activity and increasing Nrf2 signaling pathway.

  17. Effect of bFGF on radiation-induced apoptosis of vascular endothelial cells

    International Nuclear Information System (INIS)

    Gu Qingyang; Wang Dewen; Li Yuejuan; Peng Ruiyun; Dong Bo; Wang Zhaohai; Liu Jie; Deng Hua; Jiang Tao

    2003-01-01

    Objective: To study the effect of bFGF on radiation-induced apoptosis vascular endothelial cells. Methods: A cell line PAE (porcine aortic endothelial cells) and primary cultured HUVEC (human umbilical vein endothelial cells) were irradiated with 60 Co γ-rays to establish cell apoptosis models. Flow cytometry with annexin-V-FITC + PI labeling was used to evaluate cell apoptosis. Different amounts of bFGF were used to study their effects on radiation-induced endothelial cell apoptosis. Results and Conclusions: It is found that bFGF could inhibit radiation-induced endothelial cell apoptosis in a considerable degree

  18. Noscapine induces mitochondria-mediated apoptosis in human colon cancer cells in vivo and in vitro

    International Nuclear Information System (INIS)

    Yang, Zi-Rong; Liu, Meng; Peng, Xiu-Lan; Lei, Xiao-Fei; Zhang, Ji-Xiang; Dong, Wei-Guo

    2012-01-01

    Highlights: ► Noscapine inhibited cell viability of colon cancer in a time- and dose- dependent manner. ► G 2 /M phase arrest and chromatin condensation and nuclear fragmentation were induced. ► Noscapine promoted apoptosis via mitochondrial pathways. ► 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 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.

  19. Ex vivo measurement of calpain activation in human peripheral blood lymphocytes by detection of immunoreactive products of calpastatin degradation.

    Directory of Open Access Journals (Sweden)

    Jacek M Witkowski

    2008-01-01

    Full Text Available Limited proteolysis of multiple intracellular proteins by endogenous Ca-dependent cysteine proteases--calpains--is an important regulatory mechanism for cell proliferation, apoptosis etc. Its importance for cellular functions is stressed by existence of endogenous calpain inhibitors--calpastatins. The calpain-calpastatin system within living cells is in a fragile balance, which depends on both partners. The interdependence of calpain--a protease--and calpastatin--an endogenous inhibitor and at the same time a substrate for this enzyme makes any assessment of actual activity of this enzyme in the cells very difficult. In this work we made an attempt to estimate and compare the activity of calpain in human peripheral blood lymphocytes by assessing the levels of limited proteolysis of calpastatin in these cells by western blot, while at the same time the levels of calpain protein inside these cells was measured by flow cytometry. Our results indicate that it is possible to compare (semi-quantitatively the activities of calpain in peripheral blood CD4+ and CD19+ lymphocytes from various donors that way. Preliminary results showed that calpain activity is increased in the CD4+ T cells isolated from peripheral blood of rheumatoid arthritis patients as compared to control lymphocytes. Extremely high intrinsic activity of calpain was detected in chronic lymphocytic leukemia (CD19+ cells. All this confirms the detection of immunoreactive products of calpastatin as a good maker of endogenous calpain activity.

  20. Crude Flavonoid Extract of Medicinal Herb Zingibar officinale Inhibits Proliferation and Induces Apoptosis in Hepatocellular Carcinoma Cells.

    Science.gov (United States)

    Elkady, Ayman I; Abu-Zinadah, Osama A; Hussein, Rania Abd El Hamid

    2017-07-05

    There is an urgent need to improve the clinical management of hepatocellular carcinoma (HCC), one of the most common causes of global cancer-related deaths. Zingibar officinale is a medicinal herb used throughout history for both culinary and medicinal purposes. It has antioxidant, anticarcinogenic, and free radical scavenging properties. Previously, we proved that the crude flavonoid extract of Z. officinale (CFEZO) inhibited growth and induced apoptosis in several cancer cell lines. However, the effect of the CFEZO on an HCC cell line has not yet been evaluated. In this study, we explored the anticancer activity of CFEZO against an HCC cell line, HepG2. CFEZO significantly inhibited proliferation and induced apoptosis in HepG2 cells. Typical apoptotic morphological and biochemical changes, including cell shrinkage and detachment, nuclear condensation and fragmentation, DNA degradation, and comet tail formation, were observed after treatments with CFEZO. The apoptogenic activity of CFEZO involved induction of ROS, depletion of GSH, disruption of the mitochondrial membrane potential, activation of caspase 3/9, and an increase in the Bax/Bcl-2 ratio. CFEZO treatments induced upregulation of p53 and p21 expression and downregulation of cyclin D1 and cyclin-dependent kinase-4 expression, which were accompanied by G2/M phase arrest. These findings suggest that CFEZO provides a useful foundation for studying and developing novel chemotherapeutic agents for the treatment of HCC.

  1. Nutrient Availability Alters the Effect of Autophagy on Sulindac Sulfide-Induced Colon Cancer Cell Apoptosis

    Directory of Open Access Journals (Sweden)

    Shiun-Kwei Chiou

    2012-01-01

    Full Text Available Autophagy is a catabolic process by which a cell degrades its intracellular materials to replenish itself. Induction of autophagy under various cellular stress stimuli can lead to either cell survival or cell death via apoptotic and/or autophagic (nonapoptotic pathways. The NSAID sulindac sulfide induces apoptosis in colon cancer cells. Here, we show that inhibition of autophagy under serum-deprived conditions resulted in significant reductions of sulindac sulfide-induced apoptosis in HT-29 colon cancer cells. In contrast, inhibition of autophagy under conditions where serum is available significantly increased sulindac sulfide-induced apoptosis in HT-29 cells. We previously showed that the apoptosis inhibitor, survivin, plays a role in regulating NSAID-induced apoptosis and autophagic cell death. Here, we show that survivin protein half-life is increased in the presence of autophagy inhibitors under serum-deprived conditions, but not under conditions when serum is available. Thus, the increased levels of survivin may be a factor contributing to inhibition of sulindac sulfide-induced apoptosis under serum-deprived conditions. These results suggest that whether a cell lives or dies due to autophagy induction depends on the balance of factors that regulate both autophagic and apoptotic processes.

  2. 4SC-202 activates ASK1-dependent mitochondrial apoptosis pathway to inhibit hepatocellular carcinoma cells

    International Nuclear Information System (INIS)

    Fu, Meili; Wan, Fuqiang; Li, Zhengling; Zhang, Fenghua

    2016-01-01

    The aim of the present study is to investigate the potential anti-hepatocellular carcinoma (HCC) cell activity by 4SC-202, a novel class I HDAC inhibitor (HDACi). The associated signaling mechanisms were also analyzed. We showed that 4SC-202 treatment induced potent cytotoxic and proliferation–inhibitory activities against established HCC cell lines (HepG2, HepB3, SMMC-7721) and patient-derived primary HCC cells. Further, adding 4SC-202 in HCC cells activated mitochondrial apoptosis pathway, which was evidenced by mitochondrial permeability transition pore (mPTP) opening, cytochrome C cytosol release and caspase-3/-9 activation. Inhibition of this apoptosis pathway, by caspase-3/-9 inhibitors, mPTP blockers, or by shRNA-mediated knockdown of cyclophilin-D (Cyp-D, a key component of mPTP), significantly attenuated 4SC-202-induced HCC cell death and apoptosis. Reversely, over-expression of Cyp-D enhanced 4SC-202's sensitivity in HCC cells. Further studies showed that 4SC-202 induced apoptosis signal-regulating kinase 1 (ASK1) activation, causing it translocation to mitochondria and physical association with Cyp-D. This mitochondrial ASK1-Cyp-D complexation appeared required for mediating 4SC-202-induced apoptosis activation. ASK1 stable knockdown by targeted-shRNAs largely inhibited 4SC-202-induced mPTP opening, cytochrome C release, and following HCC cell apoptotic death. Together, we suggest that 4SC-202 activates ASK1-dependent mitochondrial apoptosis pathway to potently inhibit human HCC cells. - Highlights: • 4SC-202 exerts potent anti-proliferative and cytotoxic activity against established/primary HCC cells. • SC-202-induced anti-HCC cell activity relies on caspase-dependent apoptosis activation. • 4SC-202 activates Cyp-D-dependent mitochondrial apoptosis pathway in HCC cells. • 4SC-202 activates ASK1 in HCC cells, causing it translocation to mitochondria. • Mitochondrial ASK1-Cyp-D complexation mediates 4SC-202's activity in HCC cells.

  3. 4SC-202 activates ASK1-dependent mitochondrial apoptosis pathway to inhibit hepatocellular carcinoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Meili, E-mail: fumeilidrlinyi@tom.com [Department of Infectious Disease, Linyi People' s Hospital, Linyi 276000 (China); Wan, Fuqiang [Department of Head and Neck Surgery, Linyi Tumor Hospital, Linyi 276000 (China); Li, Zhengling [Department of Nursing, Tengzhou Central People' s Hospital, Tengzhou 277500 (China); Zhang, Fenghua [Department of Operating Room, Linyi People' s Hospital, Linyi 276000 (China)

    2016-03-04

    The aim of the present study is to investigate the potential anti-hepatocellular carcinoma (HCC) cell activity by 4SC-202, a novel class I HDAC inhibitor (HDACi). The associated signaling mechanisms were also analyzed. We showed that 4SC-202 treatment induced potent cytotoxic and proliferation–inhibitory activities against established HCC cell lines (HepG2, HepB3, SMMC-7721) and patient-derived primary HCC cells. Further, adding 4SC-202 in HCC cells activated mitochondrial apoptosis pathway, which was evidenced by mitochondrial permeability transition pore (mPTP) opening, cytochrome C cytosol release and caspase-3/-9 activation. Inhibition of this apoptosis pathway, by caspase-3/-9 inhibitors, mPTP blockers, or by shRNA-mediated knockdown of cyclophilin-D (Cyp-D, a key component of mPTP), significantly attenuated 4SC-202-induced HCC cell death and apoptosis. Reversely, over-expression of Cyp-D enhanced 4SC-202's sensitivity in HCC cells. Further studies showed that 4SC-202 induced apoptosis signal-regulating kinase 1 (ASK1) activation, causing it translocation to mitochondria and physical association with Cyp-D. This mitochondrial ASK1-Cyp-D complexation appeared required for mediating 4SC-202-induced apoptosis activation. ASK1 stable knockdown by targeted-shRNAs largely inhibited 4SC-202-induced mPTP opening, cytochrome C release, and following HCC cell apoptotic death. Together, we suggest that 4SC-202 activates ASK1-dependent mitochondrial apoptosis pathway to potently inhibit human HCC cells. - Highlights: • 4SC-202 exerts potent anti-proliferative and cytotoxic activity against established/primary HCC cells. • SC-202-induced anti-HCC cell activity relies on caspase-dependent apoptosis activation. • 4SC-202 activates Cyp-D-dependent mitochondrial apoptosis pathway in HCC cells. • 4SC-202 activates ASK1 in HCC cells, causing it translocation to mitochondria. • Mitochondrial ASK1-Cyp-D complexation mediates 4SC-202's activity in HCC cells.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    Chandra, Dhyan

    2012-01-01

    Azadirachta indica, commonly known as neem, has a wide range of medicinal properties. Neem extracts and its purified products have been examined for induction of apoptosis in multiple cancer cell types; however, its underlying mechanisms remain undefined. We show that neem oil (i.e., neem), which contains majority of neem limonoids including azadirachtin, induced apoptotic and autophagic cell death. Gene silencing demonstrated that caspase cascade was initiated by the activation of caspase-9, whereas caspase-8 was also activated late during neem-induced apoptosis. Pretreatment of cancer cells with pan caspase inhibitor, z-VAD inhibited activities of both initiator caspases (e.g., caspase-8 and -9) and executioner caspase-3. Neem induced the release of cytochrome c and apoptosis-inducing factor (AIF) from mitochondria, suggesting the involvement of both caspase-dependent and AIF-mediated apoptosis. p21 deficiency caused an increase in caspase activities at lower doses of neem, whereas p53 deficiency did not modulate neem-induced caspase activation. Additionally, neem treatment resulted in the accumulation of LC3-II in cancer cells, suggesting the involvement of autophagy in neem-induced cancer cell death. Low doses of autophagy inhibitors (i.e., 3-methyladenine and LY294002) did not prevent accumulation of neem-induced LC3-II in cancer cells. Silencing of ATG5 or Beclin-1 further enhanced neem-induced cell death. Phosphoinositide 3-kinase (PI3K) or autophagy inhibitors increased neem-induced caspase-3 activation and inhibition of caspases enhanced neem-induced autophagy. Together, for the first time, we demonstrate that neem induces caspase-dependent and AIF-mediated apoptosis, and autophagy in cancer cells. PMID:22915764

  6. Calpain 4 is not necessary for LFA-1-mediated function in CD4+ T cells.

    Directory of Open Access Journals (Sweden)

    Sarah A Wernimont

    2010-05-01

    Full Text Available T cell activation and immune synapse formation require the appropriate activation and clustering of the integrin, LFA-1. Previous work has reported that the calpain family of calcium-dependent proteases are important regulators of integrin activation and modulate T cell adhesion and migration. However, these studies have been limited by the use of calpain inhibitors, which have known off-target effects.Here, we used a LoxP/CRE system to specifically deplete calpain 4, a small regulatory calpain subunit required for expression and activity of ubiquitously expressed calpains 1 and 2, in CD4+ T cells. CD4+ and CD8+ T cells developed normally in Capn4(F/F:CD4-CRE mice and had severely diminished expression of Calpain 1 and 2, diminished talin proteolysis and impaired casein degradation. Calpain 4-deficient T cells showed no difference in adhesion or migration on the LFA-1 ligand ICAM-1 compared to control T cells. Moreover, there was no impairment in conjugation between Capn4(F/F:CD4-CRE T cells and antigen presenting cells, and the conjugates were still capable of polarizing LFA-1, PKC-theta and actin to the immune synapse. Furthermore, T cells from Capn4(F/F:CD4-CRE mice showed normal proliferation in response to either anti-CD3/CD28 coated beads or cognate antigen-loaded splenocytes. Finally, there were no differences in the rates of apoptosis following extrinsic and intrinsic apoptotic stimuli.Our findings demonstrate that calpain 4 is not necessary for LFA-1-mediated adhesion, conjugation or migration. These results challenge previous reports that implicate a central role for calpains in the regulation of T cell LFA-1 function.

  7. Decreased expression of MUC1 induces apoptosis and inhibits migration in pancreatic cancer PANC-1 cells via regulation of Slug pathway.

    Science.gov (United States)

    Zhao, Ping; Meng, Meng; Xu, Bin; Dong, Aiping; Ni, Guangzhen; Lu, Lianfang

    2017-12-06

    MUC1, a membrane tethered mucin glycoprotein, is overexpressed in > 60% of human pancreatic cancers (PCs), and is associated with poor prognosis and enhanced metastasis. Here, we report the effect of silencing MUC1 expression on the growth, migration and invasive ability of pancreatic cancer cells, and explored its mechanisms. We observed that siRNA mediated suppression of the MUC1 expression significantly reduced invasive and migrative capability and induced apoptosis of the pancreatic cancer PANC-1 cells. We found that Slug was inhibited in the MUC1 siRNA transfected PANC-1 cells (MUC1 siRNA/PANC-1 cells). Expression of PUMA and E-cadherin was increased in the MUC1 siRNA/PANC-1 cells. PANC-1 cells overexpressing full long Slug gene (when transfected with Slug cDNA plasmid) significantly inhibited PUMA and E-cadherin expression in the MUC1 siRNA/PANC-1 cells. Silencing PUMA expression inhibited apoptosis in the MUC1 siRNA transfected PANC-1 cells (MUC1 siRNA/PANC-1 cells). Silencing E-cadherin expression restored the invasion and migration ability in the MUC1 siRNA/PANC-1 cells. We therefore concluded that silencing MUC1 expression inhibited migration and invasion, and induced apoptosis of PANC-1 cells via downregulation of Slug and upregulation of Slug dependent PUMA and E-cadherin expression. MUC1 could serve as a potential therapeutic target in pancreatic cancer.

  8. Human retinal pigment epithelial cell-induced apoptosis in activated T cells

    DEFF Research Database (Denmark)

    Jørgensen, A; Wiencke, A K; la Cour, M

    1998-01-01

    human retinal pigment epithelial (RPE) cells can induce apoptosis in activated T cells. METHODS: Fas ligand (FasL) expression was detected by flow cytometry and immunohistochemistry. Cultured RPE cells were cocultured with T-cell lines and peripheral blood lymphocytes for 6 hours to 2 days. Induction...... of apoptosis was detected by 7-amino-actinomycin D and annexin V staining. RESULTS: Retinal pigment epithelial cells expressed FasL and induced apoptosis in activated Fas+ T cells. Blocking of Fas-FasL interaction with antibody strongly inhibited RPE-mediated T-cell apoptosis. Retinal pigment epithelial cells...... induced apoptosis in several activated T-cell populations and T-cell lines, including T-cell antigen receptor (TCR)-CD3-negative T-cell lines. In contrast, RPE cells induced little or no apoptosis in resting peripheral T cells. Major histocompatibility complex (MHC) class II monoclonal antibodies, which...

  9. Inhibition of CYP2E1 attenuates chronic alcohol intake-induced myocardial contractile dysfunction and apoptosis.

    Science.gov (United States)

    Zhang, Rong-Huai; Gao, Jian-Yuan; Guo, Hai-Tao; Scott, Glenda I; Eason, Anna R; Wang, Xiao-Ming; Ren, Jun

    2013-01-01

    Alcohol intake is associated with myocardial contractile dysfunction and apoptosis although the precise mechanism is unclear. This study was designed to examine the effect of the cytochrome P450 enzyme CYP2E1 inhibition on ethanol-induced cardiac dysfunction. Adult male mice were fed a 4% ethanol liquid or pair-fed control diet for 6weeks. Following 2weeks of diet feeding, a cohort of mice started to receive the CYP2E1 inhibitor diallyl sulfide (100mg/kg/d, i.p.) for the remaining feeding duration. Cardiac function was assessed using echocardiographic and IonOptix systems. Western blot analysis was used to evaluate CYP2E1, heme oxygenase-1 (HO-1), iNOS, the intracellular Ca(2+) regulatory proteins sarco(endo)plasmic reticulum Ca(2+)-ATPase, Na(+)Ca(2+) exchanger and phospholamban, pro-apoptotic protein cleaved caspase-3, Bax, c-Jun-NH(2)-terminal kinase (JNK) and apoptosis signal-regulating kinase (ASK-1). Ethanol led to elevated levels of CYP2E1, iNOS and phospholamban, decreased levels of HO-1 and Na(+)Ca(2+) exchanger, cardiac contractile and intracellular Ca(2+) defects, cardiac fibrosis, overt O(2)(-) production, and apoptosis accompanied with increased phosphorylation of JNK and ASK-1, the effects were significantly attenuated or ablated by diallyl sulfide. Inhibitors of JNK and ASK-1 but not HO-1 inducer or iNOS inhibitor obliterated ethanol-induced cardiomyocyte contractile dysfunction, substantiating a role for JNK and ASK-1 signaling in ethanol-induced myocardial injury. Taken together, these findings suggest that ethanol metabolism through CYP2E1 may contribute to the pathogenesis of alcoholic cardiomyopathy including myocardial contractile dysfunction, oxidative stress and apoptosis, possibly through activation of JNK and ASK-1 signaling. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Downregulation of Akt1 Inhibits Anchorage-Independent Cell Growth and Induces Apoptosis in Cancer Cells

    Directory of Open Access Journals (Sweden)

    Xuesong Liu

    2001-01-01

    Full Text Available The serine/threonine kinases, Akti/PKBα, Akt2/PKBβ, and Akt3/PKBγ, play a critical role in preventing cancer cells from undergoing apoptosis. However, the function of individual Akt isoforms in the tumorigenicity of cancer cells is still not well defined. In the current study, we used an AM antisense oligonucleotide (AS to specifically downregulate Akti protein in both cancer and normal cells. Our data indicate that AM AS treatment inhibits the ability of MiaPaCa-2, H460, HCT-15, and HT1080 cells to grow in soft agar. The treatment also induces apoptosis in these cancer cells as demonstrated by FRCS analysis and a caspase activity assay. Conversely, Akti AS treatment has little effect on the cell growth and survival of normal human cells including normal human fibroblast (NHF, fibroblast from muscle (FBM, and mammary gland epithelial 184135 cells. In addition, AM AS specifically sensitizes cancer cells to typical chemotherapeutic agents. Thus, Akti is indispensable for maintaining the tumorigenicity of cancer cells. Inhibition of AM may provide a powerful sensitization agent for chemotherapy specifically in cancer cells.

  11. Menadione induces the formation of reactive oxygen species and depletion of GSH-mediated apoptosis and inhibits the FAK-mediated cell invasion.

    Science.gov (United States)

    Kim, Yun Jeong; Shin, Yong Kyoo; Sohn, Dong Suep; Lee, Chung Soo

    2014-09-01

    Menadione induces apoptosis in tumor cells. However, the mechanism of apoptosis in ovarian cancer cells exposed to menadione is not clear. In addition, it is unclear whether menadione-induced apoptosis is mediated by the depletion of glutathione (GSH) contents that is associated with the formation of reactive oxygen species. Furthermore, the effect of menadione on the invasion and migration of human epithelial ovarian cancer cells has not been studied. Therefore, we investigated the effects of menadione exposure on apoptosis, cell adhesion, and cell migration using the human epithelial ovarian carcinoma cell lines OVCAR-3 and SK-OV-3. The results suggest that menadione may induce apoptotic cell death in ovarian carcinoma cell lines by activating the mitochondrial pathway and the caspase-8- and Bid-dependent pathways. The apoptotic effect of menadione appears to be mediated by the formation of reactive oxygen species and the depletion of GSH. Menadione inhibited fetal-bovine-serum-induced cell adhesion and migration of OVCAR-3 cells, possibly through the suppression the focal adhesion kinase (FAK)-dependent activation of cytoskeletal-associated components. Therefore, menadione might be beneficial in the treatment of epithelial ovarian adenocarcinoma and combination therapy.

  12. Angiotensin II protects primary rat hepatocytes against bile salt-induced apoptosis.

    Directory of Open Access Journals (Sweden)

    Golnar Karimian

    Full Text Available UNLABELLED: Angiotensin II (AT-II is a pro-fibrotic compound that acts via membrane-bound receptors (AT-1R/AT-2R and thereby activates hepatic stellate cells (HSCs. AT-II receptor blockers (ARBs are thus important candidates in the treatment of liver fibrosis. However, multiple case reports suggest that AT-1R blockers may induce hepatocyte injury. Therefore, we investigated the effect of AT-II and its receptor blockers on cytokine-, oxidative stress- and bile salt-induced cell death in hepatocytes. Primary rat hepatocytes were exposed to TNF-α/Actinomycin D, the ROS-generating agent menadione or the bile salts: glycochenodeoxycholic acid (GCDCA and tauro-lithocholic acid-3 sulfate (TLCS, to induce apoptosis. AT-II (100 nmol/L was added 10 minutes prior to the cell death-inducing agent. AT-1R antagonists (Sartans and the AT-2R antagonist PD123319 were used at 1 µmol/L. Apoptosis (caspase-3 activity, acridine orange staining and necrosis (Sytox green staining were quantified. Expression of CHOP (marker for ER stress and AT-II receptor mRNAs were quantified by Q-PCR. AT-II dose-dependently reduced GCDCA-induced apoptosis of hepatocytes (-50%, p<0.05 without inducing necrosis. In addition, AT-II reduced TLCS-induced apoptosis of hepatocytes (-50%, p<0.05. However, AT-II did not suppress TNF/Act-D and menadione-induced apoptosis. Only the AT-1R antagonists abolished the protective effect of AT-II against GCDCA-induced apoptosis. AT-II increased phosphorylation of ERK and a significant reversal of the protective effect of AT-II was observed when signaling kinases, including ERK, were inhibited. Moreover, AT-II prevented the GCDCA-induced expression of CHOP (the marker of the ER-mediated apoptosis. CONCLUSION: Angiotensin II protects hepatocytes from bile salt-induced apoptosis through a combined activation of PI3-kinase, MAPKs, PKC pathways and inhibition of bile salt-induced ER stress. Our results suggest a mechanism for the observed hepatocyte

  13. The role of cPLA2 in Methylglyoxal-induced cell apoptosis of HUVECs

    International Nuclear Information System (INIS)

    Yuan, Jie; Zhu, Chao; Hong, Yali; Sun, Zongxing; Fang, Xianjun; Wu, Biao; Li, Shengnan

    2017-01-01

    Methylglyoxal (MGO), a highly reactive dicarbonyl compound, is mainly formed as a byproduct of glycolysis. Elevated MGO level is known to induce apoptosis of vascular endothelial cells, which is implicated with progression of atherosclerosis and diabetic complications. However, the underlying mechanisms have not been exhaustively investigated yet. Here, we further characterized the mechanisms how MGO induced apoptosis in human umbilical vein endothelial cells (HUVECs). Our data revealed that cytosolic phospholipase A2 (cPLA2) played an important role in MGO-induced cell apoptosis. It was found that MGO could increase both the activity and expression of cPLA2. Inhibition of cPLA2 by Pyrrophenone (PYR) or siRNA significantly attenuated the MGO-induced apoptosis. Additionally, MGO time-dependently decreased the phosphorylation of nuclear factor κB (NF-κB). Pretreatment of the cells with NF-κB inhibitor, BAY11-7082, further increased MGO-induced apoptosis of HUVECs, indicating that NF-κB played a survival role in this MGO-induced apoptosis. Furthermore, in the presence of si-cPLA2 or PYR, MGO no longer decreased NF-κB phosphorylation. Beyond that, the antioxidant N-acetyl cysteine (NAC) could reverse the changes of both cPLA2 and NF-κB caused by MGO. p38, the upstream of cPLA2, was also significantly phosphorylated by MGO. However, p38 inhibitor failed to reverse the apoptosis induced by MGO. This study gives an important insight into the downstream signaling mechanisms of MGO, cPLA2-NF-κB, in endothelial apoptosis. - Highlights: • cPLA2 participated in MGO-induced HUVECs apoptosis. • Inhibition of NF-κB was involved in MGO-cPLA2-mediated cell apoptosis. • Antioxidant NAC attenuated MGO-induced cPLA2 activation and cell apoptosis.

  14. The role of cPLA2 in Methylglyoxal-induced cell apoptosis of HUVECs

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Jie; Zhu, Chao; Hong, Yali; Sun, Zongxing; Fang, Xianjun [Jiangsu Provincial Key Lab of Cardiovascular Diseases and Molecular intervention, Department of Pharmacology, Nanjing Medical University, Nanjing 210029 (China); Wu, Biao, E-mail: wubiao@ncu.edu.cn [Department of Surgery, The First Affiliated Hospital, Nanchang University (China); Li, Shengnan, E-mail: snli@njmu.edu.cn [Jiangsu Provincial Key Lab of Cardiovascular Diseases and Molecular intervention, Department of Pharmacology, Nanjing Medical University, Nanjing 210029 (China)

    2017-05-15

    Methylglyoxal (MGO), a highly reactive dicarbonyl compound, is mainly formed as a byproduct of glycolysis. Elevated MGO level is known to induce apoptosis of vascular endothelial cells, which is implicated with progression of atherosclerosis and diabetic complications. However, the underlying mechanisms have not been exhaustively investigated yet. Here, we further characterized the mechanisms how MGO induced apoptosis in human umbilical vein endothelial cells (HUVECs). Our data revealed that cytosolic phospholipase A2 (cPLA2) played an important role in MGO-induced cell apoptosis. It was found that MGO could increase both the activity and expression of cPLA2. Inhibition of cPLA2 by Pyrrophenone (PYR) or siRNA significantly attenuated the MGO-induced apoptosis. Additionally, MGO time-dependently decreased the phosphorylation of nuclear factor κB (NF-κB). Pretreatment of the cells with NF-κB inhibitor, BAY11-7082, further increased MGO-induced apoptosis of HUVECs, indicating that NF-κB played a survival role in this MGO-induced apoptosis. Furthermore, in the presence of si-cPLA2 or PYR, MGO no longer decreased NF-κB phosphorylation. Beyond that, the antioxidant N-acetyl cysteine (NAC) could reverse the changes of both cPLA2 and NF-κB caused by MGO. p38, the upstream of cPLA2, was also significantly phosphorylated by MGO. However, p38 inhibitor failed to reverse the apoptosis induced by MGO. This study gives an important insight into the downstream signaling mechanisms of MGO, cPLA2-NF-κB, in endothelial apoptosis. - Highlights: • cPLA2 participated in MGO-induced HUVECs apoptosis. • Inhibition of NF-κB was involved in MGO-cPLA2-mediated cell apoptosis. • Antioxidant NAC attenuated MGO-induced cPLA2 activation and cell apoptosis.

  15. Aminomethylphosphonic Acid and Methoxyacetic Acid Induce Apoptosis in Prostate Cancer Cells

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    Keshab R. Parajuli

    2015-05-01

    Full Text Available Aminomethylphosphonic acid (AMPA and its parent compound herbicide glyphosate are analogs to glycine, which have been reported to inhibit proliferation and promote apoptosis of cancer cells, but not normal cells. Methoxyacetic acid (MAA is the active metabolite of ester phthalates widely used in industry as gelling, viscosity and stabilizer; its exposure is associated with developmental and reproductive toxicities in both rodents and humans. MAA has been reported to suppress prostate cancer cell growth by inducing growth arrest and apoptosis. However, it is unknown whether AMPA and MAA can inhibit cancer cell growth. In this study, we found that AMPA and MAA inhibited cell growth in prostate cancer cell lines (LNCaP, C4-2B, PC-3 and DU-145 through induction of apoptosis and cell cycle arrest at the G1 phase. Importantly, the AMPA-induced apoptosis was potentiated with the addition of MAA, which was due to downregulation of the anti-apoptotic gene baculoviral inhibitor of apoptosis protein repeat containing 2 (BIRC2, leading to activation of caspases 7 and 3. These results demonstrate that the combination of AMPA and MAA can promote the apoptosis of prostate cancer cells, suggesting that they can be used as potential therapeutic drugs in the treatment of prostate cancer.

  16. Aminomethylphosphonic acid and methoxyacetic acid induce apoptosis in prostate cancer cells.

    Science.gov (United States)

    Parajuli, Keshab R; Zhang, Qiuyang; Liu, Sen; You, Zongbing

    2015-05-22

    Aminomethylphosphonic acid (AMPA) and its parent compound herbicide glyphosate are analogs to glycine, which have been reported to inhibit proliferation and promote apoptosis of cancer cells, but not normal cells. Methoxyacetic acid (MAA) is the active metabolite of ester phthalates widely used in industry as gelling, viscosity and stabilizer; its exposure is associated with developmental and reproductive toxicities in both rodents and humans. MAA has been reported to suppress prostate cancer cell growth by inducing growth arrest and apoptosis. However, it is unknown whether AMPA and MAA can inhibit cancer cell growth. In this study, we found that AMPA and MAA inhibited cell growth in prostate cancer cell lines (LNCaP, C4-2B, PC-3 and DU-145) through induction of apoptosis and cell cycle arrest at the G1 phase. Importantly, the AMPA-induced apoptosis was potentiated with the addition of MAA, which was due to downregulation of the anti-apoptotic gene baculoviral inhibitor of apoptosis protein repeat containing 2 (BIRC2), leading to activation of caspases 7 and 3. These results demonstrate that the combination of AMPA and MAA can promote the apoptosis of prostate cancer cells, suggesting that they can be used as potential therapeutic drugs in the treatment of prostate cancer.

  17. Noscapine induces mitochondria-mediated apoptosis in human colon cancer cells in vivo and in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zi-Rong; Liu, Meng; Peng, Xiu-Lan; Lei, Xiao-Fei; Zhang, Ji-Xiang [Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province (China); Dong, Wei-Guo, E-mail: dongwg1966@yahoo.com.cn [Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province (China)

    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. Cloning and Characterization of Genes that Inhibit TRAIL-Induced Apoptosis of Breast Cancer Cells

    National Research Council Canada - National Science Library

    Shu, Hong-Bing

    2003-01-01

    ...). However, some cancer cells are resistant to TRAIL-induced apoptosis (3, 4, 6-13). The purpose of this proposed study is to clone and characterize such inhibitory genes of TRAIL-induced apoptosis...

  19. UVC-induced apoptosis in Dubca cells is independent of JNK activation and p53Ser-15 phosphorylation

    International Nuclear Information System (INIS)

    Chathoth, Shahanas; Thayyullathil, Faisal; Hago, Abdulkader; Shahin, Allen; Patel, Mahendra; Galadari, Sehamuddin

    2009-01-01

    Ultraviolet C (UVC) irradiation in mammalian cell lines activates a complex signaling network that leads to apoptosis. By using Dubca cells as a model system, we report the presence of a UVC-induced apoptotic pathway that is independent of c-Jun N-terminal kinases (JNKs) activation and p53 phosphorylation at Ser 15 . Irradiation of Dubca cells with UVC results in a rapid JNK activation and phosphorylation of its downstream target c-Jun, as well as, phosphorylation of activating transcription factor 2 (ATF2). Pre-treatment with JNK inhibitor, SP600125, inhibited UVC-induced c-Jun phosphorylation without preventing UVC-induced apoptosis. Similarly, inhibition of UVC-induced p53 phosphorylation did not prevent Dubca cell apoptosis, suggesting that p53 Ser-15 phosphorylation is not associated with UVC-induced apoptosis signaling. The pan-caspase inhibitor z-VAD-fmk inhibited UVC-induced PARP cleavage, DNA fragmentation, and ultimately apoptosis of Dubca cells. Altogether, our study clearly indicates that UVC-induced apoptosis is independent of JNK and p53 activation in Dubca cells, rather, it is mediated through a caspase dependent pathway. Our findings are not in line with the ascribed critical role for JNKs activation, and downstream phosphorylation of targets such as c-Jun and ATF2 in UVC-induced apoptosis.

  20. Inhibition of histone deacetylases 1 and 6 enhances cytarabine-induced apoptosis in pediatric acute myeloid leukemia cells.

    Directory of Open Access Journals (Sweden)

    Xuelian Xu

    Full Text Available BACKGROUND: Pediatric acute myeloid leukemia (AML remains a challenging disease to treat even with intensified cytarabine-based chemotherapy. Histone deacetylases (HDACs have been reported to be promising therapeutic targets for treating AML. However, HDAC family members that are involved in chemotherapy sensitivities remain unknown. In this study, we sought to identify members of the HDAC family that are involved in cytarabine sensitivities, and to select the optimal HDACI that is most efficacious when combined with cytarabine for treating children with AML. METHODOLOGY: Expression profiles of classes I, II, and IV HDACs in 4 pediatric AML cell lines were determined by Western blotting. Inhibition of class I HDACs by different HDACIs was measured post immnunoprecipitation. Individual down-regulation of HDACs in pediatric AML cells was performed with lentiviral shRNA. The effects of cytarabine and HDACIs on apoptosis were determined by flow cytometry analysis. RESULTS: Treatments with structurally diverse HDACIs and HDAC shRNA knockdown experiments revealed that down-regulation of both HDACs 1 and 6 is critical in enhancing cytarabine-induced apoptosis in pediatric AML, at least partly mediated by Bim. However, down-regulation of HDAC2 may negatively impact cytarabine sensitivities in the disease. At clinically achievable concentrations, HDACIs that simultaneously inhibited both HDACs 1 and 6 showed the best anti-leukemic activities and significantly enhanced cytarabine-induced apoptosis. CONCLUSION: Our results further confirm that HDACs are bona fide therapeutic targets for treating pediatric AML and suggest that pan-HDACIs may be more beneficial than isoform-specific drugs.

  1. Time course in calpain activity and autolysis in slow and fast skeletal muscle during clenbuterol treatment.

    Science.gov (United States)

    Douillard, Aymeric; Galbes, Olivier; Rossano, Bernadette; Vernus, Barbara; Bonnieu, Anne; Candau, Robin; Py, Guillaume

    2011-02-01

    Calpains are Ca2+ cysteine proteases that have been proposed to be involved in the cytoskeletal remodeling and wasting of skeletal muscle. Cumulative evidence also suggests that β2-agonists can lead to skeletal muscle hypertrophy through a mechanism probably related to calcium-dependent proteolytic enzyme. The aim of our study was to monitor calpain activity as a function of clenbuterol treatment in both slow and fast phenotype rat muscles. For this purpose, for 21 days we followed the time course of the calpain activity and of the ubiquitous calpain 1 and 2 autolysis, as well as muscle remodeling in the extensor digitorum longus (EDL) and soleus muscles of male Wistar rats treated daily with clenbuterol (4 mg·kg-1). A slow to fast fiber shift was observed in both the EDL and soleus muscles after 9 days of treatment, while hypertrophy was observed only in EDL after 9 days of treatment. Soleus muscle but not EDL muscle underwent an early apoptonecrosis phase characterized by hematoxylin and eosin staining. Total calpain activity was increased in both the EDL and soleus muscles of rats treated with clenbuterol. Moreover, calpain 1 autolysis increased significantly after 14 days in the EDL, but not in the soleus. Calpain 2 autolysis increased significantly in both muscles 6 hours after the first clenbuterol injection, indicating that clenbuterol-induced calpain 2 autolysis occurred earlier than calpain 1 autolysis. Together, these data suggest a preferential involvement of calpain 2 autolysis compared with calpain 1 autolysis in the mechanisms underlying the clenbuterol-induced skeletal muscle remodeling.

  2. Kaempferol alleviates ox-LDL-induced apoptosis by up-regulation of autophagy via inhibiting PI3K/Akt/mTOR pathway in human endothelial cells.

    Science.gov (United States)

    Che, Jianbo; Liang, Bing; Zhang, Yuan; Wang, Yi; Tang, Jianyu; Shi, Gongning

    Oxidized low-density lipoprotein (ox-LDL) has been reported to induce apoptosis of endothelial cells (ECs) and contribute to the progression of atherosclerosis. Kaempferol has been shown to possess antiatherosclerotic effect. The aim of the present study was to evaluate the effect of kaempferol on ox-LDL-induced apoptosis of human umbilical vein endothelial cells (HUVECs) and its possible molecular basis. The results showed that kaempferol alleviated ox-LDL-induced apoptosis. Kaempferol increased the ratio of LC3-II/I and beclin-1 level in ox-LDL-induced HUVECs. Moreover, the expression of p-Akt and p-mTOR was down-regulated after treatment with kaempferol in ox-LDL-treated HUVECs, which is similar to the effect of PI3K inhibitor (LY294002) or mTOR inhibitor [rapamycin (RAP)]. Besides, autophagy induced by kaempferol was enhanced by LY294002 or RAP, while kaempferol-induced autophagy was attenuated with insulin treatment, the activator of PI3K/Akt/mTOR pathway. Furthermore, insulin also abated the effect of kaempferol on cell viability and apoptosis in ox-LDL-induced HUVECs. The results indicated that kaempferol alleviated ox-LDL-induced cell apoptosis by up-regulation of autophagy via inhibiting PI3K/Akt/mTOR pathway in human ECs. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Elevation of cAMP Levels Inhibits Doxorubicin-Induced Apoptosis in Pre- B ALL NALM- 6 Cells Through Induction of BAD Phosphorylation and Inhibition of P53 Accumulation.

    Science.gov (United States)

    Fatemi, Ahmad; Kazemi, Ahmad; Kashiri, Meysam; Safa, Majid

    2015-01-01

    Recognition of the molecular mechanisms of cAMP action against DNA damage-induced apoptosis can be useful to improve the efficacy of DNA damaging therapeutic agents. Considering the critical role of bcl-2-associated death promoter (BAD) and p53 proteins in DNA damage -induced apoptosis, the aim of this study was to assess the effect of cAMP-elevating agents on these proteins in doxorubicin-treated pre-B acute lymphoblastic leukemia (pre-B ALL) NALM-6 cells.The pre-B ALL cell line NALM-6 was cultured and treated with doxorubicin in combination with or without cAMP-elevating agents forskolin and 3-isobutyl-1-methylxanthine (IBMX). Cell viability was measured by trypan blue staining and MTT assay. For evaluation of apoptosis, annexin-V staining by flow cytometry and caspase-3 activity assay were used. Protein expression of p53, BAD and phoshorylated BAD was detected by western blotting analysis.cAMP-increasing agents diminished the doxorubicin-mediated cytotoxicity in NALM-6 cells as indicated by the viability assays. Annexin-V apoptosis assay showed that the cAMP-elevating agents decreased doxorubicin-induced apoptosis. Moreover, doxorubicin-induced caspase-3 activity was attenuated in the presence of cAMP-increasing agents. Western blot results revealed the reduced expression of p53 protein in cells treated with combination of cAMP-elevating agents and doxorubicin in contrast to cells treated with doxorubicin alone. Expression of total BAD protein was not affected by doxorubicin and cAMP-elevating agents. However, phosphorylation of BAD protein was induced in the presence of cAMP-elevating agents. Our study suggests that elevated cAMP levels inhibit doxorubicin-induced apoptosis in pre-B ALL cells through induction of BAD phosphorylation and abrogation of p53 accumulation.

  4. Inhibition of autophagy enhances DNA damage-induced apoptosis by disrupting CHK1-dependent S phase arrest

    Energy Technology Data Exchange (ETDEWEB)

    Liou, Jong-Shian; Wu, Yi-Chen; Yen, Wen-Yen; Tang, Yu-Shuan [Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 115, Taiwan, ROC (China); Kakadiya, Rajesh B.; Su, Tsann-Long [Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan, ROC (China); Yih, Ling-Huei, E-mail: lhyih@gate.sinica.edu.tw [Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 115, Taiwan, ROC (China)

    2014-08-01

    DNA damage has been shown to induce autophagy, but the role of autophagy in the DNA damage response and cell fate is not fully understood. BO-1012, a bifunctional alkylating derivative of 3a-aza-cyclopenta[a]indene, is a potent DNA interstrand cross-linking agent with anticancer activity. In this study, BO-1012 was found to reduce DNA synthesis, inhibit S phase progression, and induce phosphorylation of histone H2AX on serine 139 (γH2AX) exclusively in S phase cells. Both CHK1 and CHK2 were phosphorylated in response to BO-1012 treatment, but only depletion of CHK1, but not CHK2, impaired BO-1012-induced S phase arrest and facilitated the entry of γH2AX-positive cells into G2 phase. CHK1 depletion also significantly enhanced BO-1012-induced cell death and apoptosis. These results indicate that BO-1012-induced S phase arrest is a CHK1-dependent pro-survival response. BO-1012 also resulted in marked induction of acidic vesicular organelle (AVO) formation and microtubule-associated protein 1 light chain 3 (LC3) processing and redistribution, features characteristic of autophagy. Depletion of ATG7 or co-treatment of cells with BO-1012 and either 3-methyladenine or bafilomycin A1, two inhibitors of autophagy, not only reduced CHK1 phosphorylation and disrupted S phase arrest, but also increased cleavage of caspase-9 and PARP, and cell death. These results suggest that cells initiate S phase arrest and autophagy as pro-survival responses to BO-1012-induced DNA damage, and that suppression of autophagy enhances BO-1012-induced apoptosis via disruption of CHK1-dependent S phase arrest. - Highlights: • Autophagy inhibitors enhanced the cytotoxicity of a DNA alkylating agent, BO-1012. • BO-1012-induced S phase arrest was a CHK1-dependent pro-survival response. • Autophagy inhibition enhanced BO-1012 cytotoxicity via disrupting the S phase arrest.

  5. Metformin protects rat hepatocytes against bile acid-induced apoptosis.

    Directory of Open Access Journals (Sweden)

    Titia E Woudenberg-Vrenken

    Full Text Available BACKGROUND: Metformin is used in the treatment of Diabetes Mellitus type II and improves liver function in patients with non-alcoholic fatty liver disease (NAFLD. Metformin activates AMP-activated protein kinase (AMPK, the cellular energy sensor that is sensitive to changes in the AMP/ATP-ratio. AMPK is an inhibitor of mammalian target of rapamycin (mTOR. Both AMPK and mTOR are able to modulate cell death. AIM: To evaluate the effects of metformin on hepatocyte cell death. METHODS: Apoptotic cell death was induced in primary rat hepatocytes using either the bile acid glycochenodeoxycholic acid (GCDCA or TNFα in combination with actinomycin D (actD. AMPK, mTOR and phosphoinositide-3 kinase (PI3K/Akt were inhibited using pharmacological inhibitors. Apoptosis and necrosis were quantified by caspase activation, acridine orange staining and Sytox green staining respectively. RESULTS: Metformin dose-dependently reduces GCDCA-induced apoptosis, even when added 2 hours after GCDCA, without increasing necrotic cell death. Metformin does not protect against TNFα/ActD-induced apoptosis. The protective effect of metformin is dependent on an intact PI3-kinase/Akt pathway, but does not require AMPK/mTOR-signaling. Metformin does not inhibit NF-κB activation. CONCLUSION: Metformin protects against bile acid-induced apoptosis and could be considered in the treatment of chronic liver diseases accompanied by inflammation.

  6. Evodiamine Induces Apoptosis and Inhibits Migration of HCT-116 Human Colorectal Cancer Cells

    Directory of Open Access Journals (Sweden)

    Lv-Cui Zhao

    2015-11-01

    Full Text Available Evodiamine (EVO exhibits strong anti-cancer effects. However, the effect of EVO on the human colorectal cancer cell line HCT-116 has not been explored in detail, and its underlying molecular mechanisms remain unknown. In the present study, cell viability was assessed by Cell Counting Kit-8 (CCK-8. Cell cycle and apoptosis were measured by flow cytometry, and morphological changes in the nucleus were examined by fluorescence microscopy and Hoechst staining. Cell motility was detected by Transwell assay. ELISA was used to assess the protein levels of autocrine motility factor (AMF in the cell supernatant, and protein expression was determined by Western blotting. Our results showed that EVO inhibited the proliferation of HCT-116 cells, caused accumulation of cells in S and G2/M phases, and reduced the levels of the secreted form of AMF. The protein levels of tumor suppressor protein (p53, Bcl-2 Associated X protein (Bax, B cell CLL/lymphoma-2 (Bcl-2, phosphoglucose isomerase (PGI, phosphorylated signal transducers and activators of transcription 3 (p-STAT3 and matrix metalloproteinase 3 (MMP3 were altered in cells treated with EVO. Taken together, our results suggest that EVO modulates the activity of the p53 signaling pathway to induce apoptosis and downregulate MMP3 expression by inactivating the JAK2/STAT3 pathway through the downregulation of PGI to inhibit migration of HCT-116 human colorectal cancer cells.

  7. RBL2/p130 is a direct AKT target and is required to induce apoptosis upon AKT inhibition in lung cancer and mesothelioma cell lines.

    Science.gov (United States)

    Pentimalli, Francesca; Forte, Iris M; Esposito, Luca; Indovina, Paola; Iannuzzi, Carmelina A; Alfano, Luigi; Costa, Caterina; Barone, Daniela; Rocco, Gaetano; Giordano, Antonio

    2018-04-02

    The retinoblastoma (RB) protein family includes RB1/p105, RBL1/p107, and RBL2/p130, which are key factors in cell-cycle regulation and stand at the crossroads of multiple pathways dictating cell fate decisions. The role of RB proteins in apoptosis is controversial because they can inhibit or promote apoptosis depending on the context, on the apoptotic stimuli and on their intrinsic status, impacting on the response to antitumoral treatments. Here we identified RBL2/p130 as a direct substrate of the AKT kinase, a key antiapoptotic factor hyperactive in multiple cancer types. We showed that RBL2/p130 and AKT1 physically interact and AKT phosphorylates RBL2/p130 Ser941, located in the pocket domain, but not when this residue is mutated into Ala. We found that pharmacological inhibition of AKT, through the highly selective AKT inhibitor VIII (AKTiVIII), impairs RBL2/p130 Ser941 phosphorylation and increases RBL2/p130 stability, mRNA expression and nuclear levels in both lung cancer and mesothelioma cell lines, mirroring the more extensively studied effects on the p27 cell-cycle inhibitor. Consistently, AKT inhibition reduced cell viability, induced cell accumulation in G0/G1, and triggered apoptosis, which proved to be largely dependent on RBL2/p130 itself, as shown upon RBL2/p130 silencing. AKT inhibition induced RBL2/p130-dependent apoptosis also in HEK-293 cells, in which re-expression of a short hairpin-resistant RBL2/p130 was able to rescue AKTiVIII-induced apoptosis upon RBL2/p130 silencing. Our data also showed that the combination of AKT and cyclin-dependent kinases (CDK) inhibitors, which converge on the re-activation of RBL2/p130 antitumoral potential, could be a promising anticancer strategy.

  8. Inhibition of Oncogenic Transcription Factor REL by the Natural Product Derivative Calafianin Monomer 101 Induces Proliferation Arrest and Apoptosis in Human B-Lymphoma Cell Lines.

    Science.gov (United States)

    Yeo, Alan T; Chennamadhavuni, Spandan; Whitty, Adrian; Porco, John A; Gilmore, Thomas D

    2015-04-23

    Increased activity of transcription factor NF-κB has been implicated in many B-cell lymphomas. We investigated effects of synthetic compound calafianin monomer (CM101) on biochemical and biological properties of NF-κB. In human 293 cells, CM101 selectively inhibited DNA binding by overexpressed NF-κB subunits REL (human c-Rel) and p65 as compared to NF-κB p50, and inhibition of REL and p65 DNA binding by CM101 required a conserved cysteine residue. CM101 also inhibited DNA binding by REL in human B-lymphoma cell lines, and the sensitivity of several B-lymphoma cell lines to CM101-induced proliferation arrest and apoptosis correlated with levels of cellular and nuclear REL. CM101 treatment induced both phosphorylation and decreased expression of anti-apoptotic protein Bcl-XL, a REL target gene product, in sensitive B-lymphoma cell lines. Ectopic expression of Bcl-XL protected SUDHL-2 B-lymphoma cells against CM101-induced apoptosis, and overexpression of a transforming mutant of REL decreased the sensitivity of BJAB B-lymphoma cells to CM101-induced apoptosis. Lipopolysaccharide-induced activation of NF-κB signaling upstream components occurred in RAW264.7 macrophages at CM101 concentrations that blocked NF-κB DNA binding. Direct inhibitors of REL may be useful for treating B-cell lymphomas in which REL is active, and may inhibit B-lymphoma cell growth at doses that do not affect some immune-related responses in normal cells.

  9. Inhibition of CLIC4 enhances autophagy and triggers mitochondrial and ER stress-induced apoptosis in human glioma U251 cells under starvation.

    Directory of Open Access Journals (Sweden)

    Jiateng Zhong

    Full Text Available CLIC4/mtCLIC, a chloride intracellular channel protein, localizes to mitochondria, endoplasmic reticulum (ER, nucleus and cytoplasm, and participates in the apoptotic response to stress. Apoptosis and autophagy, the main types of the programmed cell death, seem interconnected under certain stress conditions. However, the role of CLIC4 in autophagy regulation has yet to be determined. In this study, we demonstrate upregulation and nuclear translocation of the CLIC4 protein following starvation in U251 cells. CLIC4 siRNA transfection enhanced autophagy with increased LC3-II protein and puncta accumulation in U251 cells under starvation conditions. In that condition, the interaction of the 14-3-3 epsilon isoform with CLIC4 was abolished and resulted in Beclin 1 overactivation, which further activated autophagy. Moreover, inhibiting the expression of CLIC4 triggered both mitochondrial apoptosis involved in Bax/Bcl-2 and cytochrome c release under starvation and endoplasmic reticulum stress-induced apoptosis with CHOP and caspase-4 upregulation. These results demonstrate that CLIC4 nuclear translocation is an integral part of the cellular response to starvation. Inhibiting the expression of CLIC4 enhances autophagy and contributes to mitochondrial and ER stress-induced apoptosis under starvation.

  10. 3-bromopyruvate and sodium citrate target glycolysis, suppress survivin, and induce mitochondrial-mediated apoptosis in gastric cancer cells and inhibit gastric orthotopic transplantation tumor growth.

    Science.gov (United States)

    Wang, Ting-An; Zhang, Xiao-Dong; Guo, Xing-Yu; Xian, Shu-Lin; Lu, Yun-Fei

    2016-03-01

    Glycolysis is the primary method utilized by cancer cells to produce the energy (adenosine triphosphate, ATP) required for cell proliferation. Therefore, inhibition of glycolysis may inhibit tumor growth. We previously found that both 3-bromopyruvate (3-BrPA) and sodium citrate (SCT) can inhibit glycolysis in vitro; however, the underlying inhibitory mechanisms remain unclear. In the present study, we used a human gastric cancer cell line (SGC-7901) and an orthotopic transplantation tumor model in nude mice to explore the specific mechanisms of 3-BrPA and SCT. We found that both 3-BrPA and SCT effectively suppressed cancer cell proliferation, arrested the cell cycle, induced apoptosis, and decreased the production of lactate and ATP. 3-BrPA significantly reduced the glycolytic enzyme hexokinase activity, while SCT selectively inhibited phosphofructokinase-1 activity. Furthermore, 3-BrPA and SCT upregulated the expression of pro-apoptotic proteins (Bax, cytochrome c, and cleaved caspase-3) and downregulated the expression of anti-apoptotic proteins (Bcl-2 and survivin). Finally, our animal model of gastric cancer indicated that intraperitoneal injection of 3-BrPA and SCT suppressed orthotopic transplantation tumor growth and induced tumor apoptosis. Taken together, these results suggest that 3-BrPA and SCT selectively suppress glycolytic enzymes, decrease ATP production, induce mitochondrial-mediated apoptosis, downregulate survivin, and inhibit tumor growth. Moreover, an intraperitoneal injection is an effective form of administration of 3-BrPA and SCT.

  11. Epigallocatechin-3-gallate attenuates apoptosis and autophagy in concanavalin A-induced hepatitis by inhibiting BNIP3

    Directory of Open Access Journals (Sweden)

    Li S

    2016-02-01

    Full Text Available Sainan Li, Yujing Xia, Kan Chen, Jingjing Li, Tong Liu, Fan Wang, Jie Lu, Yingqun Zhou, Chuanyong Guo Department of Gastroenterology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, People’s Republic of China Background: Epigallocatechin-3-gallate (EGCG is the most effective compound in green tea, and possesses a wide range of beneficial effects, including anti-inflammatory, antioxidant, antiobesity, and anticancer effects. In this study, we investigated the protective effects of EGCG in concanavalin A (ConA-induced hepatitis in mice and explored the possible mechanisms involved in these effects.Methods: Balb/C mice were injected with ConA (25 mg/kg to induce acute autoimmune hepatitis, and EGCG (10 or 30 mg/kg was administered orally twice daily for 10 days before ConA injection. Serum liver enzymes, proinflammatory cytokines, and other marker proteins were determined 2, 8, and 24 hours after the ConA administration.Results: BNIP3 mediated cell apoptosis and autophagy in ConA-induced hepatitis. EGCG decreased the immunoreaction and pathological damage by reducing inflammatory factors, such as TNF-α, IL-6, IFN-γ, and IL-1β. EGCG also exhibited an antiapoptotic and antiautophagic effect by inhibiting BNIP3 via the IL-6/JAKs/STAT3 pathway.Conclusion: EGCG attenuated liver injury in ConA-induced hepatitis by downregulating IL-6/JAKs/STAT3/BNIP3-mediated apoptosis and autophagy. Keywords: concanavalin A, hepatitis, EGCG, autophagy, apoptosis, BNIP3, STAT3, JAKs, IL-6

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

    Science.gov (United States)

    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.

  13. 3,3'-diindolylmethane potentiates tumor necrosis factor-related apoptosis-inducing ligand-induced apoptosis of gastric cancer cells.

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    Ye, Yang; Miao, Shuhan; Wang, Yan; Zhou, Jianwei; Lu, Rongzhu

    2015-05-01

    Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) specifically kills cancer cells without destroying the majority of healthy cells. However, numerous types of cancer cell, including gastric cancer cells, tend to be resistant to TRAIL. The bioactive product 3,3'-diindolylmethane (DIM), which is derived from cruciferous vegetables, is also currently recognized as a candidate anticancer agent. In the present study, a Cell Counting Kit 8 cell growth assay and an Annexin V-fluorescein isothiocyanate apoptosis assay were performed to investigate the potentiating effect of DIM on TRAIL-induced apoptosis in gastric cancer cells, and the possible mechanisms of this potentiation. The results obtained demonstrated that, compared with TRAIL or DIM treatment alone, co-treatment with TRAIL (25 or 50 ng/ml) and DIM (10 µmol/l) induced cytotoxic and apoptotic effects in BGC-823 and SGC-7901 gastric cancer cells. Furthermore, western blot analysis revealed that the protein expression levels of death receptor 5 (DR5), CCAAT/enhancer binding protein homologous protein (CHOP) and glucose-regulated protein 78 (GRP78) were upregulated in the co-treated gastric cancer cells. To the best of our knowledge, the present study is the first to provide evidence that DIM sensitizes TRAIL-induced inhibition of proliferation and apoptosis in gastric cancer cells, accompanied by the upregulated expression of DR5, CHOP and GRP78 proteins, which may be involved in endoplasmic reticulum stress mechanisms.

  14. Curcumin Inhibits Apoptosis of Chondrocytes through Activation ERK1/2 Signaling Pathways Induced Autophagy

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    Xiaodong Li

    2017-04-01

    Full Text Available Osteoarthritis (OA is an inflammatory disease of load-bearing synovial joints that is currently treated with drugs that exhibit numerous side effects and are only temporarily effective in treating pain, the main symptom of the disease. Consequently, there is an acute need for novel, safe, and more effective chemotherapeutic agents for the treatment of osteoarthritis and related arthritic diseases. Curcumin, the principal curcuminoid and the most active component in turmeric, is a biologically active phytochemical. Evidence from several recent in vitro studies suggests that curcumin may exert a chondroprotective effect through actions such as anti-inflammatory, anti-oxidative stress, and anti-catabolic activity that are critical for mitigating OA disease pathogenesis and symptoms. In the present study, we investigated the protective mechanisms of curcumin on interleukin 1β (IL-1β-stimulated primary chondrocytes in vitro. The treatment of interleukin (IL-1β significantly reduces the cell viability of chondrocytes in dose and time dependent manners. Co-treatment of curcumin with IL-1β significantly decreased the growth inhibition. We observed that curcumin inhibited IL-1β-induced apoptosis and caspase-3 activation in chondrocytes. Curcumin can increase the expression of phosphorylated extracellular signal-regulated kinases 1/2 (ERK1/2, autophagy marker light chain 3 (LC3-II, and Beclin-1 in chondrocytes. The expression of autophagy markers could be decreased when the chondrocytes were incubated with ERK1/2 inhibitor U0126. Our results suggest that curcumin suppresses apoptosis and inflammatory signaling through its actions on the ERK1/2-induced autophagy in chondrocytes. We propose that curcumin should be explored further for the prophylactic treatment of osteoarthritis in humans and companion animals.

  15. Role of Bax in resveratrol-induced apoptosis of colorectal carcinoma cells

    International Nuclear Information System (INIS)

    Mahyar-Roemer, Mojgan; Köhler, Hans; Roemer, Klaus

    2002-01-01

    The natural plant polyphenol resveratrol present in some foods including grapes, wine, and peanuts, has been implicated in the inhibition, delay, and reversion of cellular events associated with heart diseases and tumorigenesis. Recent work has suggested that the cancer chemoprotective effect of the compound is primarily linked to its ability to induce cell division cycle arrest and apoptosis, the latter possibly through the activation of pro-apoptotic proteins such as Bax. The expression, subcellular localization, and importance of Bax for resveratrol-provoked apoptosis were assessed in human HCT116 colon carcinoma cells and derivatives with both bax alleles inactivated. Low to moderate concentrations of resveratrol induced co-localization of cellular Bax protein with mitochondria, collapse of the mitochondrial membrane potential, activation of caspases 3 and 9, and finally, apoptosis. In the absence of Bax, membrane potential collapse was delayed, and apoptosis was reduced but not absent. Resveratrol inhibited the formation of colonies by both HCT116 and HCT116 bax -/- cells. Resveratrol at physiological doses can induce a Bax-mediated and a Bax-independent mitochondrial apoptosis. Both can limit the ability of the cells to form colonies

  16. Cdk5 phosphorylates non-genotoxically overexpressed p53 following inhibition of PP2A to induce cell cycle arrest/apoptosis and inhibits tumor progression

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    Kumari Ratna

    2010-07-01

    Full Text Available Abstract Background p53 is the most studied tumor suppressor and its overexpression may or may not cause cell death depending upon the genetic background of the cells. p53 is degraded by human papillomavirus (HPV E6 protein in cervical carcinoma. Several stress activated kinases are known to phosphorylate p53 and, among them cyclin dependent kinase 5 (Cdk5 is one of the kinase studied in neuronal cell system. Recently, the involvement of Cdk5 in phosphorylating p53 has been shown in certain cancer types. Phosphorylation at specific serine residues in p53 is essential for it to cause cell growth inhibition. Activation of p53 under non stress conditions is poorly understood. Therefore, the activation of p53 and detection of upstream kinases that phosphorylate non-genotoxically overexpressed p53 will be of therapeutic importance for cancer treatment. Results To determine the non-genotoxic effect of p53; Tet-On system was utilized and p53 inducible HPV-positive HeLa cells were developed. p53 overexpression in HPV-positive cells did not induce cell cycle arrest or apoptosis. However, we demonstrate that overexpressed p53 can be activated to upregulate p21 and Bax which causes G2 arrest and apoptosis, by inhibiting protein phosphatase 2A. Additionally, we report that the upstream kinase cyclin dependent kinase 5 interacts with p53 to phosphorylate it at Serine20 and Serine46 residues thereby promoting its recruitment on p21 and bax promoters. Upregulation and translocation of Bax causes apoptosis through intrinsic mitochondrial pathway. Interestingly, overexpressed activated p53 specifically inhibits cell-growth and causes regression in vivo tumor growth as well. Conclusion Present study details the mechanism of activation of p53 and puts forth the possibility of p53 gene therapy to work in HPV positive cervical carcinoma.

  17. Inhibition of mitochondria- and endoplasmic reticulum stress-mediated autophagy augments temozolomide-induced apoptosis in glioma cells.

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    Chien-Ju Lin

    Full Text Available Autophagy is a crucial process for cells to maintain homeostasis and survival through degradation of cellular proteins and organelles, including mitochondria and endoplasmic reticula (ER. We previously demonstrated that temozolomide (TMZ, an alkylating agent for brain tumor chemotherapy, induced reactive oxygen species (ROS/extracellular signal-regulated kinase (ERK-mediated autophagy to protect glioma cells from apoptosis. In this study, we investigated the role of mitochondrial damage and ER stress in TMZ-induced cytotoxicity. Mitochondrial depolarization and mitochondrial permeability transition pore (MPTP opening were observed as a prelude to TMZ-induced autophagy, and these were followed by the loss of mitochondrial mass. Electron transport chain (ETC inhibitors, such as rotenone (a complex I inhibitor, sodium azide (a complex IV inhibitor, and oligomycin (a complex V inhibitor, or the MPTP inhibitor, cyclosporine A, decreased mitochondrial damage-mediated autophagy, and therefore increased TMZ-induced apoptosis. TMZ treatment triggered ER stress with increased expression of GADD153 and GRP78 proteins, and deceased pro-caspase 12 protein. ER stress consequently induced autophagy through c-Jun N-terminal kinases (JNK and Ca(2+ signaling pathways. Combination of TMZ with 4-phenylbutyrate (4-PBA, an ER stress inhibitor, augmented TMZ-induced cytotoxicity by inhibiting autophagy. Taken together, our data indicate that TMZ induced autophagy through mitochondrial damage- and ER stress-dependent mechanisms to protect glioma cells. This study provides evidence that agents targeting mitochondria or ER may be potential anticancer strategies.

  18. Tetrandrine Induces Apoptosis in Human Nasopharyngeal Carcinoma NPC-TW 039 Cells by Endoplasmic Reticulum Stress and Ca2+/Calpain Pathways.

    Science.gov (United States)

    Liu, Kuo-Ching; Lin, Ya-Jing; Hsiao, Yung-Ting; Lin, Meng-Liang; Yang, Jiun-Long; Huang, Yi-Ping; Chu, Yung-Lin; Chung, Jing-Gung

    2017-11-01

    Tetrandrine is an alkaloid extracted from a traditional China medicine plant, and is considered part of food therapy as well. In addition, it has been widely reported to induce apoptotic cell death in many human cancer cells. However, the mechanism of Tetrandrine on human nasopharyngeal carcinoma cells (NPC) is still questioned. In our study, we examined whether Tetrandrine can induce apoptosis of NPC-TW 039 cells. We found that cell morphology was changed after treatment with different concentrations of Tetrandrine. Further, we indicated that the NPC-TW 039 cells viability decreased in a Tetrandrine dose-dependent manner. We also found that tetrandrine induced cell cycle arrest in G 0 /G 1 phase. Tetrandrine induced DNA condensation by DAPI staining as well. In addition, we found that Tetrandrine induced Ca 2+ release in the cytosol. At the same time, endoplasmic reticulum (ER) stress occurred. Then we used western blotting to examine the protein expression which is associated with mitochondria-mediated apoptotic pathways and caspase-dependent pathways. To further examine whether Ca 2+ was released or not with Tetrandrine induced-apoptosis, we used the chelator of Ca 2+ and showed that cell viability increased. At the same time, caspase-3 expression was decreased. Furthermore, confocal microscopy examination revealed that Tetrandrine induced expression of ER stress-related proteins GADD153 and GRP78. Our results indicate that Tetrandrine induces apoptosis through calcium-mediated ER stress and caspase pathway in NPC-TW 039 cells. In conclusion, Tetrandrine may could be used for treatment of human nasopharyngeal carcinoma in future. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  19. Pertussis toxin, an inhibitor of G(αi PCR, inhibits bile acid- and cytokine-induced apoptosis in primary rat hepatocytes.

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    Golnar Karimian

    Full Text Available Excessive hepatocyte apoptosis is a common event in acute and chronic liver diseases leading to loss of functional liver tissue. Approaches to prevent apoptosis have therefore high potential for the treatment of liver disease. G-protein coupled receptors (GPCR play crucial roles in cell fate (proliferation, cell death and act through heterotrimeric G-proteins. G(αiPCRs have been shown to regulate lipoapoptosis in hepatocytes, but their role in inflammation- or bile acid-induced apoptosis is unknown. Here, we analyzed the effect of inhibiting G(αiPCR function, using pertussis toxin (PT, on bile acid- and cytokine-induced apoptosis in hepatocytes. Primary rat hepatocytes, HepG2-rNtcp cells (human hepatocellular carcinoma cells or H-4-II-E cells (rat hepatoma cells were exposed to glycochenodeoxycholic acid (GCDCA or tumor necrosis factor-α (TNFα/actinomycin D (ActD. PT (50-200 nmol/L was added 30 minutes prior to the apoptotic stimulus. Apoptosis (caspase-3 activity, acridine orange staining and necrosis (sytox green staining were assessed. PT significantly reduced GCDCA- and TNFα/ActD-induced apoptosis in rat hepatocytes (-60%, p<0.05 in a dose-dependent manner (with no shift to necrosis, but not in HepG2-rNtcp cells or rat H-4-II-E cells. The protective effect of pertussis toxin was independent of the activation of selected cell survival signal transduction pathways, including ERK, p38 MAPK, PI3K and PKC pathways, as specific protein kinase inhibitors did not reverse the protective effects of pertussis toxin in GCDCA-exposed hepatocytes.Pertussis toxin, an inhibitor of G(αiPCRs, protects hepatocytes, but not hepatocellular carcinoma cells, against bile acid- and cytokine-induced apoptosis and has therapeutic potential as primary hepatoprotective drug, as well as adjuvant in anti-cancer therapy.

  20. Dopamine-induced apoptosis in human neuronal cells: inhibition by nucleic acides antisense to the dopamine transporter

    International Nuclear Information System (INIS)

    Porat, S.; Gabbay, M.; Tauber, M.; Ratovitski, T.; Blinder, E.; Simantov, R.

    1996-01-01

    Human neuroblastoma NMB cells take up [ 3 H]dopamine in a selective manner indicating that dopamine transporters are responsible for this uptake. These cells were therefore used as a model to study dopamine neurotoxicity, and to elucidate the role of dopamine transporters in controlling cell death. Treatment with 0.05-0.4 mM dopamine changed cells' morphology within 4 h, accompanied by retraction of processes, shrinkage, apoptosis-like atrophy, accumulation of apoptotic particles, DNA fragmentation and cell death. Cycloheximide inhibited dopamine's effect, suggesting that induction of apoptosis by dopamine was dependent upon protein synthesis. Dopamine cytotoxicity, monitored morphologically by flow cytometric analysis, and by lactate dehydrogenase released, was blocked by cocaine but not by the noradrenaline and serotonin uptake blockers desimipramine and imipramine, respectively. Attempting to inhibit dopamine transport and toxicity in a drug-free and highly selective way, three 18-mer dopamine transporter antisense phosphorothioate oligonucleotides (numbers 1, 2 and 3) and a new plasmid vector expressing the entire rat dopamine transporter complementary DNA in the antisense orientation were prepared and tested. Antisense phosphorothioate oligonucleotide 3 inhibited [ 3 H]dopamine uptake in a time- and dose-dependent manner. Likewise, transient transfection of NMB cells with the plasmid expressing dopamine transporter complementary DNA in the antisense orientation partially blocked [ 3 H]dopamine uptake. Antisense phosphorothioate oligonucleotide 3 also decreased, dose-dependently, the toxic effect of dopamine and 6-hydroxydopamine. Western blot analysis with newly prepared anti-human dopamine transporter antibodies showed that antisense phosphorothioate oligonucleotide 3 decreased the transporter protein level. These studies contribute to better understand the mechanism of dopamine-induced apoptosis and neurotoxicity. (Copyright (c) 1996 Elsevier Science B

  1. Toll-like receptor 9 is required for opioid-induced microglia apoptosis.

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    Lei He

    2011-04-01

    Full Text Available Opioids have been widely applied in clinics as one of the most potent pain relievers for centuries, but their abuse has deleterious physiological effects beyond addiction. However, the underlying mechanism by which microglia in response to opioids remains largely unknown. Here we show that morphine induces the expression of Toll-like receptor 9 (TLR9, a key mediator of innate immunity and inflammation. Interestingly, TLR9 deficiency significantly inhibited morphine-induced apoptosis in microglia. Similar results were obtained when endogenous TLR9 expression was suppressed by the TLR9 inhibitor CpGODN. Inhibition of p38 MAPK by its specific inhibitor SB203580 attenuated morphine-induced microglia apoptosis in wild type microglia. Morphine caused a dramatic decrease in Bcl-2 level but increase in Bax level in wild type microglia, but not in TLR9 deficient microglia. In addition, morphine treatment failed to induce an increased levels of phosphorylated p38 MAPK and MAP kinase kinase 3/6 (MKK3/6, the upstream MAPK kinase of p38 MAPK, in either TLR9 deficient or µ-opioid receptor (µOR deficient primary microglia, suggesting an involvement of MAPK and µOR in morphine-mediated TLR9 signaling. Moreover, morphine-induced TLR9 expression and microglia apoptosis appears to require μOR. Collectively, these results reveal that opioids prime microglia to undergo apoptosis through TLR9 and µOR as well. Taken together, our data suggest that inhibition of TLR9 and/or blockage of µOR is capable of preventing opioid-induced brain damage.

  2. Apoptosis and autophagy induced by pyropheophorbide-α methyl ester-mediated photodynamic therapy in human osteosarcoma MG-63 cells.

    Science.gov (United States)

    Huang, Qiu; Ou, Yun-Sheng; Tao, Yong; Yin, Hang; Tu, Ping-Hua

    2016-06-01

    Pyropheophorbide-α methyl ester (MPPa) was a second-generation photosensitizer with many potential applications. Here, we explored the impact of MPPa-mediated photodynamic therapy (MPPa-PDT) on the apoptosis and autophagy of human osteosarcoma (MG-63) cells as well as the relationships between apoptosis and autophagy of the cells, and investigated the related molecular mechanisms. We found that MPPa-PDT demonstrated the ability to inhibit MG-63 cell viability in an MPPa concentration- and light dose-dependent manner, and to induce apoptosis via the mitochondrial apoptosis pathway. Additionally, MPPa-PDT could also induce autophagy of MG-63 cell. Meanwhile, the ROS scavenger N-acetyl-L-cysteine (NAC) and the Jnk inhibitor SP600125 were found to inhibit the MPPa-PDT-induced autophagy, and NAC could also inhibit Jnk phosphorylation. Furthermore, pretreatment with the autophagy inhibitor 3-methyladenine or chloroquine showed the potential in reducing the apoptosis rate induced by MPPa-PDT in MG-63 cells. Our results indicated that the mitochondrial pathway was involved in MPPa-PDT-induced apoptosis of MG-63 cells. Meanwhile the ROS-Jnk signaling pathway was involved in MPPa-PDT-induced autophagy, which further promoted the apoptosis in MG-63 cells.

  3. SIRT1 sensitizes hepatocellular carcinoma cells expressing hepatitis B virus X protein to oxidative stress-induced apoptosis

    International Nuclear Information System (INIS)

    Srisuttee, Ratakorn; Koh, Sang Seok; Malilas, Waraporn; Moon, Jeong; Cho, Il-Rae; Jhun, Byung Hak; Horio, Yoshiyuki; Chung, Young-Hwa

    2012-01-01

    Highlights: ► Up-regulation of SIRT1 protein and activity sensitizes Hep3B-HBX cells to oxidative stress-induced apoptosis. ► Nuclear localization of SIRT1 is not required for oxidation-induced apoptosis. ► Ectopic expression and enhanced activity of SIRT1 attenuate JNK phosphorylation. ► Inhibition of SIRT1 activity restores resistance to oxidation-induced apoptosis through JNK activation. -- Abstract: We previously showed that SIRT1 deacetylase inhibits proliferation of hepatocellular carcinoma cells expressing hepatitis B virus (HBV) X protein (HBX), by destabilization of β-catenin. Here, we report another role for SIRT1 in HBX-mediated resistance to oxidative stress. Ectopic expression and enhanced activity of SIRT1 sensitize Hep3B cells stably expressing HBX to oxidative stress-induced apoptosis. SIRT1 mutant analysis showed that nuclear localization of SIRT1 is not required for sensitization of oxidation-mediated apoptosis. Furthermore, ectopic expression of SIRT1 and treatment with resveratrol (a SIRT1 activator) attenuated JNK phosphorylation, which is a prerequisite for resistance to oxidative stress-induced apoptosis. Conversely, suppression of SIRT1 activity with nicotinamide inhibited the effect of resveratrol on JNK phosphorylation, leading to restoration of resistance to oxidation-induced apoptosis. Taken together, these results suggest that up-regulation of SIRT1 under oxidative stress may be a therapeutic strategy for treatment of hepatocellular carcinoma cells related to HBV through inhibition of JNK activation.

  4. SIRT1 sensitizes hepatocellular carcinoma cells expressing hepatitis B virus X protein to oxidative stress-induced apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Srisuttee, Ratakorn [WCU, Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-735 (Korea, Republic of); Koh, Sang Seok [Immunotherapy Research Center, Korea Research Institute of Bioscience and Biotechnology, University of Science and Technology, Daejeon 305-333 (Korea, Republic of); Department of Functional Genomics, University of Science and Technology, Daejeon 305-333 (Korea, Republic of); Malilas, Waraporn; Moon, Jeong; Cho, Il-Rae [WCU, Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-735 (Korea, Republic of); Jhun, Byung Hak [Department of Applied Nanoscience, Pusan National University, Busan 609-735 (Korea, Republic of); Horio, Yoshiyuki [Department of Pharmacology, Sapporo Medical University, Sapporo 060-8556 (Japan); Chung, Young-Hwa, E-mail: younghc@pusan.ac.kr [WCU, Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-735 (Korea, Republic of)

    2012-12-07

    Highlights: Black-Right-Pointing-Pointer Up-regulation of SIRT1 protein and activity sensitizes Hep3B-HBX cells to oxidative stress-induced apoptosis. Black-Right-Pointing-Pointer Nuclear localization of SIRT1 is not required for oxidation-induced apoptosis. Black-Right-Pointing-Pointer Ectopic expression and enhanced activity of SIRT1 attenuate JNK phosphorylation. Black-Right-Pointing-Pointer Inhibition of SIRT1 activity restores resistance to oxidation-induced apoptosis through JNK activation. -- Abstract: We previously showed that SIRT1 deacetylase inhibits proliferation of hepatocellular carcinoma cells expressing hepatitis B virus (HBV) X protein (HBX), by destabilization of {beta}-catenin. Here, we report another role for SIRT1 in HBX-mediated resistance to oxidative stress. Ectopic expression and enhanced activity of SIRT1 sensitize Hep3B cells stably expressing HBX to oxidative stress-induced apoptosis. SIRT1 mutant analysis showed that nuclear localization of SIRT1 is not required for sensitization of oxidation-mediated apoptosis. Furthermore, ectopic expression of SIRT1 and treatment with resveratrol (a SIRT1 activator) attenuated JNK phosphorylation, which is a prerequisite for resistance to oxidative stress-induced apoptosis. Conversely, suppression of SIRT1 activity with nicotinamide inhibited the effect of resveratrol on JNK phosphorylation, leading to restoration of resistance to oxidation-induced apoptosis. Taken together, these results suggest that up-regulation of SIRT1 under oxidative stress may be a therapeutic strategy for treatment of hepatocellular carcinoma cells related to HBV through inhibition of JNK activation.

  5. A microtubule inhibitor, ABT-751, induces autophagy and delays apoptosis in Huh-7 cells

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Ren-Jie [Institute of Biomedical Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan (China); Department of Pathology, Kaohsiung Armed Forces General Hospital, Kaohsiung, Taiwan (China); Lin, Su-Shuan [Department of Pathology, Kaohsiung Armed Forces General Hospital, Kaohsiung, Taiwan (China); Wu, Wen-Ren [Institute of Biomedical Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan (China); Chen, Lih-Ren [Department of Biotechnology, Southern Taiwan University of Science and Technology, Tainan, Taiwan (China); Division of Physiology, Livestock Research Institute, Council of Agriculture, Taiwan (China); Li, Chien-Feng [Department of Biotechnology, Southern Taiwan University of Science and Technology, Tainan, Taiwan (China); Department of Pathology, Chi-Mei Medical Center, Tainan, Taiwan (China); National Institute of Cancer Research, National Health Research Institute, Tainan, Taiwan (China); Institute of Clinical Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Chen, Han-De; Chou, Chien-Ting; Chen, Ya-Chun [Institute of Biomedical Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan (China); Liang, Shih-Shin [Institute of Biomedical Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan (China); Department of Biotechnology, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Chien, Shang-Tao [Department of Pathology, Kaohsiung Armed Forces General Hospital, Kaohsiung, Taiwan (China); Shiue, Yow-Ling, E-mail: ylshiue@mail.nsysu.edu.tw [Institute of Biomedical Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan (China); Department of Biological Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan (China); Doctoral Degree Program in Marine Biotechnology, National Sun Yat-sen University, Kaohsiung, Taiwan (China)

    2016-11-15

    The objective was to investigate the upstream mechanisms of apoptosis which were triggered by a novel anti-microtubule drug, ABT-751, in hepatocellular carcinoma-derived Huh-7 cells. Effects of ABT-751 were evaluated by immunocytochemistry, flow cytometric, alkaline comet, soft agar, immunoblotting, CytoID, green fluorescent protein-microtubule associated protein 1 light chain 3 beta detection, plasmid transfection, nuclear/cytosol fractionation, coimmunoprecipitation, quantitative reverse transcription-polymerase chain reaction, small-hairpin RNA interference and mitochondria/cytosol fractionation assays. Results showed that ABT-751 caused dysregulation of microtubule, collapse of mitochondrial membrane potential, generation of reactive oxygen species (ROS), DNA damage, G{sub 2}/M cell cycle arrest, inhibition of anchorage-independent cell growth and apoptosis in Huh-7 cells. ABT-751 also induced early autophagy via upregulation of nuclear TP53 and downregulation of the AKT serine/threonine kinase (AKT)/mechanistic target of rapamycin (MTOR) pathway. Through modulation of the expression levels of DNA damage checkpoint proteins and G{sub 2}/M cell cycle regulators, ABT-751 induced G{sub 2}/M cell cycle arrest. Subsequently, ABT-751 triggered apoptosis with marked downregulation of B-cell CLL/lymphoma 2, upregulation of mitochondrial BCL2 antagonist/killer 1 and BCL2 like 11 protein levels, and cleavages of caspase 8 (CASP8), CASP9, CASP3 and DNA fragmentation factor subunit alpha proteins. Suppression of ROS significantly decreased ABT-751-induced autophagic and apoptotic cells. Pharmacological inhibition of autophagy significantly increased the percentages of ABT-751-induced apoptotic cells. The autophagy induced by ABT-751 plays a protective role to postpone apoptosis by exerting adaptive responses following microtubule damage, ROS and/or impaired mitochondria. - Highlights: • An anti-microtubule agent, ABT-751, induces autophagy and apoptosis in Huh-7 cells.

  6. Fisetin induces apoptosis through mitochondrial apoptosis pathway in human uveal melanoma cells.

    Science.gov (United States)

    Wang, Kai; Hu, Dan-Ning; Lin, Hui-Wen; Yang, Wei-En; Hsieh, Yi-Hsien; Chien, Hsiang-Wen; Yang, Shun-Fa

    2018-05-01

    Fisetin, a diatery flavonoid, been reported that possess anticancer effects in various cancers. The purpose of the study was to investigate the antitumor effects of fisetin in cultured uveal melanoma cell lines and compared with normal retinal pigment epithelial (RPE) cells. MTT assay was used for evaluating cytotoxic effects of fisetin. Flow cytometry study was used for the determination of apoptosis. JC-1 fluorescent reader was used to determine mitochondrial transmembrane potential changes. The results shown that fisetin dose-dependently decreased the cell viability of uveal melanoma cells but not influenced the cell viability of RPE cells. Apoptosis of uveal melanoma cells was induced by fisetin efficiently. Fisetin inhibited antiapoptotic Bcl-2 family proteins and damaged the mitochondrial transmembrane potential. The levels of proapoptotic Bcl-2 proteins, cytochrome c, and various caspase activities were increased by fisetin. In conclusion, fisetin induces apoptosis of uveal melanoma cells selectively and may be a promising agent to be explored for the treatment of uveal melanoma. © 2018 Wiley Periodicals, Inc.

  7. Effect of pH on radiation-induced apoptosis

    International Nuclear Information System (INIS)

    Chang, W. Song; Park, Heon J.; Lyons, John C.; Auger, Elizabeth A.; Lee, Hyung-Sik

    1996-01-01

    Purpose/Objective: The effect of environmental pH on the radiation-induced apoptosis in tumor cells in vitro was investigated. Materials and Methods: SCK mammary adenocarcinoma cells of A/J mice were irradiated with γ-rays using a 137 Cs irradiator and incubated in media of different pHs. After incubation at 37 degree sign C for 24-120 hrs., the extent of apoptosis was determined using agarose gel electrophoresis of DNA, in situ TUNEL staining, flow cytometry, and release of 3 H from 3 H-thymidine labeled cells. The membrane integrity, using the trypan blue exclusion method, and the clonogenicity of the cells were also determined. Results: Irradiation with 2-12 Gy of γ-rays induced apoptosis in pH 7.5 medium within 48 hrs. The radiation-induced apoptosis progressively declined as the medium pH was lowered so that little apoptosis occurred in 48 hrs. after irradiation with 12 Gy in pH 6.6 medium. However, when the cells were irradiated and incubated for 48 hrs. in pH 6.6 medium and then medium was replaced with pH 7.5 medium, apoptosis promptly occurred. Apoptosis also occurred even in pH 6.6 medium when the cells were irradiated and maintained in pH 7.5 medium for 8 hrs. or longer post-irradiation before incubation in pH 6.6 medium. Conclusion: An acidic environment markedly suppresses radiation-induced apoptosis probably by suppressing the expression of initial signals responsible for irradiation-induced apoptosis. Indications are that the signals persist in an acidic environment and trigger apoptosis when the environmental acidity is eased. Our results suggest that the acidic environment in human tumors may inhibit the apoptosis after irradiation. However, apoptosis may be triggered when reoxygenation occurs after irradiation, and thus, the intratumor environment becomes less acidic after irradiation. Not only the change in pO 2 but the change in pH during the course of fractionated radiotherapy may greatly influence the outcome of the treatment

  8. St. John's wort attenuates irinotecan-induced diarrhea via down-regulation of intestinal pro-inflammatory cytokines and inhibition of intestinal epithelial apoptosis

    International Nuclear Information System (INIS)

    Hu Zeping; Yang Xiaoxia; Chan Suiyung; Xu Anlong; Duan Wei; Zhu Yizhun; Sheu, F.-S.; Boelsterli, Urs Alex; Chan, Eli; Zhang Qiang; Wang, J.-C.; Ee, Pui Lai Rachel; Koh, H.L.; Huang Min; Zhou Shufeng

    2006-01-01

    Diarrhea is a common dose-limiting toxicity associated with cancer chemotherapy, in particular for drugs such as irinotecan (CPT-11), 5-fluouracil, oxaliplatin, capecitabine and raltitrexed. St. John's wort (Hypericum perforatum, SJW) has anti-inflammatory activity, and our preliminary study in the rat and a pilot study in cancer patients found that treatment of SJW alleviated irinotecan-induced diarrhea. In the present study, we investigated whether SJW modulated various pro-inflammatory cytokines including interleukins (IL-1β, IL-2, IL-6), interferon (IFN-γ) and tumor necrosis factor-α (TNF-α) and intestinal epithelium apoptosis in rats. The rats were treated with irinotecan at 60 mg/kg for 4 days in combination with oral SJW or SJW-free control vehicle at 400 mg/kg for 8 days. Diarrhea, tissue damage, body weight loss, various cytokines including IL-1β, IL-2, IL-6, IFN-γ and TNF-α and intestinal epithelial apoptosis were monitored over 11 days. Our studies demonstrated that combined SJW markedly reduced CPT-11-induced diarrhea and intestinal lesions. The production of pro-inflammatory cytokines such as IL-1β, IFN-γ and TNF-α was significantly up-regulated in intestine. In the mean time, combined SJW significantly suppressed the intestinal epithelial apoptosis induced by CPT-11 over days 5-11. In particular, combination of SJW significantly inhibited the expression of TNF-α mRNA in the intestine over days 5-11. In conclusion, inhibition of pro-inflammatory cytokines and intestinal epithelium apoptosis partly explained the protective effect of SJW against the intestinal toxicities induced by irinotecan. Further studies are warranted to explore the potential for STW as an agent in combination with chemotherapeutic drugs to lower their dose-limiting toxicities

  9. Mycobacterium tuberculosis nuoG is a virulence gene that inhibits apoptosis of infected host cells.

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    Kamalakannan Velmurugan

    2007-07-01

    Full Text Available The survival and persistence of Mycobacterium tuberculosis depends on its capacity to manipulate multiple host defense pathways, including the ability to actively inhibit the death by apoptosis of infected host cells. The genetic basis for this anti-apoptotic activity and its implication for mycobacterial virulence have not been demonstrated or elucidated. Using a novel gain-of-function genetic screen, we demonstrated that inhibition of infection-induced apoptosis of macrophages is controlled by multiple genetic loci in M. tuberculosis. Characterization of one of these loci in detail revealed that the anti-apoptosis activity was attributable to the type I NADH-dehydrogenase of M. tuberculosis, and was mainly due to the subunit of this multicomponent complex encoded by the nuoG gene. Expression of M. tuberculosis nuoG in nonpathogenic mycobacteria endowed them with the ability to inhibit apoptosis of infected human or mouse macrophages, and increased their virulence in a SCID mouse model. Conversely, deletion of nuoG in M. tuberculosis ablated its ability to inhibit macrophage apoptosis and significantly reduced its virulence in mice. These results identify a key component of the genetic basis for an important virulence trait of M. tuberculosis and support a direct causal relationship between virulence of pathogenic mycobacteria and their ability to inhibit macrophage apoptosis.

  10. Hydroxychloroquine preferentially induces apoptosis of CD45RO+ effector T cells by inhibiting autophagy: A possible mechanism for therapeutic modulation of T cells

    OpenAIRE

    van Loosdregt, Jorg; Spreafico, Roberto; Rossetti, Maura; Prakken, Berent J; Lotz, Martin; Albani, Salvatore

    2013-01-01

    Although hydroxychloroquine is used for treatment of numerous autoimmune disorders the mechanism is unclear. We here demonstrate that hydroxychloroquine preferentially induces apoptosis of CD45RO+ memory and effector T cells by inhibiting the survival pathway of autophagy.

  11. The synthetic epoxyquinoids jesterone dimer and epoxyquinone A monomer induce apoptosis and inhibit REL (human c-Rel) DNA binding in an IkappaBalpha-deficient diffuse large B-cell lymphoma cell line.

    Science.gov (United States)

    Liang, Mei-Chih; Bardhan, Sujata; Porco, John A; Gilmore, Thomas D

    2006-09-08

    The NF-kappaB transcription factor signaling pathway is constitutively active in many human cancers, and inhibition of this pathway can often kill cancer cells by inducing apoptosis. In this study, we show that two synthetic epoxyquinoids, jesterone dimer (JD) and epoxyquinone A monomer (EqM), are equally effective at inhibiting the growth of two human lymphoma cell lines that have constitutively nuclear REL (human c-Rel) DNA-binding complexes, but either express (SUDHL-4 cells) or do not express (RC-K8 cells) the NF-kappaB inhibitor IkappaBalpha. Furthermore, in these cells, both JD and EqM dose-dependently induced apoptosis, inhibited REL DNA-binding activity, and converted REL to a high molecular weight form. In A293 cells, JD and EqM inhibited the DNA-binding activity of overexpressed REL, but not p50. Replacement of Cys-27 with Ser in REL reduced JD- and EqM-mediated inhibition of REL DNA-binding activity. These results suggest that JD and EqM can induce apoptosis in IkappaBalpha-deficient lymphoma cells through a mechanism involving direct inhibition of transcription factor REL.

  12. (4-Methoxyphenyl)(3,4,5-trimethoxyphenyl)methanone inhibits tubulin polymerization, induces G2/M arrest, and triggers apoptosis in human leukemia HL-60 cells

    International Nuclear Information System (INIS)

    Magalhães, Hemerson I.F.; Wilke, Diego V.; Bezerra, Daniel P.; Cavalcanti, Bruno C.; Rotta, Rodrigo; Lima, Dênis P. de; Beatriz, Adilson; Moraes, Manoel O.; Diniz-Filho, Jairo; Pessoa, Claudia

    2013-01-01

    (4-Methoxyphenyl)(3,4,5-trimethoxyphenyl)methanone (PHT) is a known cytotoxic compound belonging to the phenstatin family. However, the exact mechanism of action of PHT-induced cell death remains to be determined. The aim of this study was to investigate the mechanisms underlying PHT-induced cytotoxicity. We found that PHT displayed potent cytotoxicity in different tumor cell lines, showing IC 50 values in the nanomolar range. Cell cycle arrest in G 2 /M phase along with the augmented metaphase cells was found. Cells treated with PHT also showed typical hallmarks of apoptosis such as cell shrinkage, chromatin condensation, phosphatidylserine exposure, increase of the caspase 3/7 and 8 activation, loss of mitochondrial membrane potential, and internucleosomal DNA fragmentation without affecting membrane integrity. Studies conducted with isolated tubulin and docking models confirmed that PHT binds to the colchicine site and interferes in the polymerization of microtubules. These results demonstrated that PHT inhibits tubulin polymerization, arrests cancer cells in G 2 /M phase of the cell cycle, and induces their apoptosis, exhibiting promising anticancer therapeutic potential. - Highlights: • PHT inhibits tubulin polymerization. • PHT arrests cancer cells in G 2 /M phase of the cell cycle. • PHT induces caspase-dependent apoptosis

  13. Calpain expression and activity during lens fiber cell differentiation.

    Science.gov (United States)

    De Maria, Alicia; Shi, Yanrong; Kumar, Nalin M; Bassnett, Steven

    2009-05-15

    In animal models, the dysregulated activity of calcium-activated proteases, calpains, contributes directly to cataract formation. However, the physiological role of calpains in the healthy lens is not well defined. In this study, we examined the expression pattern of calpains in the mouse lens. Real time PCR and Western blotting data indicated that calpain 1, 2, 3, and 7 were expressed in lens fiber cells. Using controlled lysis, depth-dependent expression profiles for each calpain were obtained. These indicated that, unlike calpain 1, 2, and 7, which were most abundant in cells near the lens surface, calpain 3 expression was strongest in the deep cortical region of the lens. We detected calpain activities in vitro and showed that calpains were active in vivo by microinjecting fluorogenic calpain substrates into cortical fiber cells. To identify endogenous calpain substrates, membrane/cytoskeleton preparations were treated with recombinant calpain, and cleaved products were identified by two-dimensional difference electrophoresis/mass spectrometry. Among the calpain substrates identified by this approach was alphaII-spectrin. An antibody that specifically recognized calpain-cleaved spectrin was used to demonstrate that spectrin is cleaved in vivo, late in fiber cell differentiation, at or about the time that lens organelles are degraded. The generation of the calpain-specific spectrin cleavage product was not observed in lens tissue from calpain 3-null mice, indicating that calpain 3 is uniquely activated during lens fiber differentiation. Our data suggest a role for calpains in the remodeling of the membrane cytoskeleton that occurs with fiber cell maturation.

  14. The mitochondria-mediate apoptosis of Lepidopteran cells induced by azadirachtin.

    Directory of Open Access Journals (Sweden)

    Jingfei Huang

    Full Text Available 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.

  15. The mitochondria-mediate apoptosis of Lepidopteran cells induced by azadirachtin.

    Science.gov (United States)

    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.

  16. Adipose-derived stromal cells inhibit prostate cancer cell proliferation inducing apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Takahara, Kiyoshi [Department of Urology, Faculty of Medicine, Osaka Medical College, Osaka (Japan); Ii, Masaaki, E-mail: masaii@art.osaka-med.ac.jp [Department of Pharmacology, Faculty of Medicine, Osaka Medical College, Osaka (Japan); Inamoto, Teruo; Komura, Kazumasa; Ibuki, Naokazu; Minami, Koichiro; Uehara, Hirofumi; Hirano, Hajime; Nomi, Hayahito; Kiyama, Satoshi [Department of Urology, Faculty of Medicine, Osaka Medical College, Osaka (Japan); Asahi, Michio [Department of Pharmacology, Faculty of Medicine, Osaka Medical College, Osaka (Japan); Azuma, Haruhito [Department of Urology, Faculty of Medicine, Osaka Medical College, Osaka (Japan)

    2014-04-18

    Highlights: • AdSC transplantation exhibits inhibitory effect on tumor progressions of PCa cells. • AdSC-induced PCa cell apoptosis may occur via the TGF-β signaling pathway. • High expression of the TGF-β1 gene in AdSCs. - Abstract: Mesenchymal stem cells (MSCs) have generated a great deal of interest in the field of regenerative medicine. Adipose-derived stromal cells (AdSCs) are known to exhibit extensive proliferation potential and can undergo multilineage differentiation, sharing similar characteristics to bone marrow-derived MSCs. However, as the effect of AdSCs on tumor growth has not been studied sufficiently, we assessed the degree to which AdSCs affect the proliferation of prostate cancer (PCa) cell. Human AdSCs exerted an inhibitory effect on the proliferation of androgen-responsive (LNCaP) and androgen-nonresponsive (PC3) human PCa cells, while normal human dermal fibroblasts (NHDFs) did not, and in fact promoted PCa cell proliferation to a degree. Moreover, AdSCs induced apoptosis of LNCaP cells and PC3 cells, activating the caspase3/7 signaling pathway. cDNA microarray analysis suggested that AdSC-induced apoptosis in both LNCaP and PC3 cells was related to the TGF-β signaling pathway. Consistent with our in vitro observations, local transplantation of AdSCs delayed the growth of tumors derived from both LNCaP- and PC3-xenografts in immunodeficient mice. This is the first preclinical study to have directly demonstrated that AdSC-induced PCa cell apoptosis may occur via the TGF-β signaling pathway, irrespective of androgen-responsiveness. Since autologous AdSCs can be easily isolated from adipose tissue without any ethical concerns, we suggest that therapy with these cells could be a novel approach for patients with PCa.

  17. Adipose-derived stromal cells inhibit prostate cancer cell proliferation inducing apoptosis

    International Nuclear Information System (INIS)

    Takahara, Kiyoshi; Ii, Masaaki; Inamoto, Teruo; Komura, Kazumasa; Ibuki, Naokazu; Minami, Koichiro; Uehara, Hirofumi; Hirano, Hajime; Nomi, Hayahito; Kiyama, Satoshi; Asahi, Michio; Azuma, Haruhito

    2014-01-01

    Highlights: • AdSC transplantation exhibits inhibitory effect on tumor progressions of PCa cells. • AdSC-induced PCa cell apoptosis may occur via the TGF-β signaling pathway. • High expression of the TGF-β1 gene in AdSCs. - Abstract: Mesenchymal stem cells (MSCs) have generated a great deal of interest in the field of regenerative medicine. Adipose-derived stromal cells (AdSCs) are known to exhibit extensive proliferation potential and can undergo multilineage differentiation, sharing similar characteristics to bone marrow-derived MSCs. However, as the effect of AdSCs on tumor growth has not been studied sufficiently, we assessed the degree to which AdSCs affect the proliferation of prostate cancer (PCa) cell. Human AdSCs exerted an inhibitory effect on the proliferation of androgen-responsive (LNCaP) and androgen-nonresponsive (PC3) human PCa cells, while normal human dermal fibroblasts (NHDFs) did not, and in fact promoted PCa cell proliferation to a degree. Moreover, AdSCs induced apoptosis of LNCaP cells and PC3 cells, activating the caspase3/7 signaling pathway. cDNA microarray analysis suggested that AdSC-induced apoptosis in both LNCaP and PC3 cells was related to the TGF-β signaling pathway. Consistent with our in vitro observations, local transplantation of AdSCs delayed the growth of tumors derived from both LNCaP- and PC3-xenografts in immunodeficient mice. This is the first preclinical study to have directly demonstrated that AdSC-induced PCa cell apoptosis may occur via the TGF-β signaling pathway, irrespective of androgen-responsiveness. Since autologous AdSCs can be easily isolated from adipose tissue without any ethical concerns, we suggest that therapy with these cells could be a novel approach for patients with PCa

  18. Fisetin induces apoptosis and endoplasmic reticulum stress in human non-small cell lung cancer through inhibition of the MAPK signaling pathway.

    Science.gov (United States)

    Kang, Kyoung Ah; Piao, Mei Jing; Madduma Hewage, Susara Ruwan Kumara; Ryu, Yea Seong; Oh, Min Chang; Kwon, Taeg Kyu; Chae, Sungwook; Hyun, Jin Won

    2016-07-01

    Fisetin (3,3',4',7-tetrahydroxyflavone), a dietary flavonoid compound, is currently being investigated for its anticancer effect in various cancer models, including lung cancer. Recent studies show that fisetin induces cell growth inhibition and apoptosis in the human non-small cell lung cancer line NCI-H460. In this study, we investigated whether fisetin can induce endoplasmic reticulum (ER) stress-mediated apoptosis in NCI-H460 cells. Fisetin induced mitochondrial reactive oxygen species (ROS) and characteristic signs of ER stress: ER staining; mitochondrial Ca(2+) overload; expression of ER stress-related proteins; glucose-regulated protein (GRP)-78, phosphorylation of protein kinase RNA (PKR)-like endoplasmic reticulum kinase (PERK) and phosphorylation of eukaryotic initiation factor-2 α subunit; cleavage of activating transcription factor-6; phosphorylation of inositol-requiring kinase-1 and splicing of X-box transcription factor-1; induction of C/EBP homologous protein and cleaved caspase-12. siRNA-mediated knockdown of CHOP and ATF-6 attenuated fisetin-induced apoptotic cell death. In addition, fisetin induced phosphorylation of ERK, JNK, and p38 MAPK. Moreover, silencing of the MAPK signaling pathway prevented apoptotic cell death. In summary, our results indicate that, in NCI-H460 cells, fisetin induces apoptosis and ER stress that is mediated by induction of the MAPK signaling pathway.

  19. H2O2 treatment or serum deprivation induces autophagy and apoptosis in naked mole-rat skin fibroblasts by inhibiting the PI3K/Akt signaling pathway.

    Science.gov (United States)

    Zhao, Shanmin; Li, Li; Wang, Shiyong; Yu, Chenlin; Xiao, Bang; Lin, Lifang; Cong, Wei; Cheng, Jishuai; Yang, Wenjing; Sun, Wei; Cui, Shufang

    2016-12-20

    Naked mole-rats (NMR; Heterocephalus glaber) display extreme longevity and resistance to cancer. Here, we examined whether autophagy contributes to the longevity of NMRs by assessing the effects of the PI3K/Akt pathway inhibitor LY294002 and the autophagy inhibitor chloroquine (CQ) on autophagy and apoptosis in NMR skin fibroblasts. Serum starvation, H2O2 treatment, and LY294002 treatment all increased the LC3-II/LC3-I ratio and numbers of double-membraned autophagosomes and autophagic vacuoles, and decreased levels of p70S6K, p-AktSer473, and p-AktThr308. By contrast, CQ treatment decreased p70S6K, AktSer473, and AktThr308 levels. The Bax/Bcl-2 ratio increased after 12 h of exposure to LY294002 or CQ. These data show that inhibiting the Akt pathway promotes autophagy and apoptosis in NMR skin fibroblasts. Furthermore, LY294002 or CQ treatment decreased caspase-3, p53, and HIF1-α levels, suggesting that serum starvation or H2O2 treatment increase autophagy and apoptosis in NMR skin fibroblasts by inhibiting the PI3K/Akt pathway. CQ-induced inhibition of late autophagy stages also prevented Akt activation and induced apoptosis. Finally, the HIF-1α and p53 pathways were involved in serum starvation- or H2O2-induced autophagy in NMR skin fibroblasts.

  20. Dragon (repulsive guidance molecule RGMb) inhibits E-cadherin expression and induces apoptosis in renal tubular epithelial cells.

    Science.gov (United States)

    Liu, Wenjing; Li, Xiaoling; Zhao, Yueshui; Meng, Xiao-Ming; Wan, Chao; Yang, Baoxue; Lan, Hui-Yao; Lin, Herbert Y; Xia, Yin

    2013-11-01

    Dragon is one of the three members of the repulsive guidance molecule (RGM) family, i.e. RGMa, RGMb (Dragon), and RGMc (hemojuvelin). We previously identified the RGM members as bone morphogenetic protein (BMP) co-receptors that enhance BMP signaling. Our previous studies found that Dragon is highly expressed in the tubular epithelial cells of mouse kidneys. However, the roles of Dragon in renal epithelial cells are yet to be defined. We now show that overexpression of Dragon increased cell death induced by hypoxia in association with increased cleaved poly(ADP-ribose) polymerase and cleaved caspase-3 levels in mouse inner medullary collecting duct (IMCD3) cells. Dragon also inhibited E-cadherin expression but did not affect epithelial-to-mesenchymal transition induced by TGF-β in IMCD3 cells. Previous studies suggest that the three RGM members can function as ligands for the receptor neogenin. Interestingly, our present study demonstrates that the Dragon actions on apoptosis and E-cadherin expression in IMCD3 cells were mediated by the neogenin receptor but not through the BMP pathway. Dragon expression in the kidney was up-regulated by unilateral ureteral obstruction in mice. Compared with wild-type mice, heterozygous Dragon knock-out mice exhibited 45-66% reduction in Dragon mRNA expression, decreased epithelial apoptosis, and increased tubular E-cadherin expression and had attenuated tubular injury after unilateral ureteral obstruction. Our results suggest that Dragon may impair tubular epithelial integrity and induce epithelial apoptosis both in vitro and in vivo.

  1. [Study on thaspine in inducing apoptosis of A549 cell].

    Science.gov (United States)

    Zhang, Yan-min; He, Lang-chong

    2007-04-01

    To investigate the effect of thaspine on the cellular proliferation, apoptosis and cell cycle in A549 cell line. A549 cell was cultured with different concentrations of thaspine. Cellular proliferation was detected with MTT, apoptosis and cell cycle were checked with Flow Cytometer, and change of microstructure was observed by transmission electron microscope. Thaspine could inhibit the proliferation and induce apoptosis of A549 cell in a time-dose dependent manner. Cell cycle was significantly stopped at the S phase by thaspine with FCM technology. Under electronic microscope, the morphology of A549 cell showed nuclear karyopycnosis, chromatin agglutination and typical apoptotic body when the cell was treated with thaspine. Thaspine has the effects of anti-tumor and inducing apoptosis.

  2. Apoptosis of murine melanoma B16-BL6 cells induced by quercetin targeting mitochondria, inhibiting expression of PKC-alpha and translocating PKC-delta.

    Science.gov (United States)

    Zhang, Xian-Ming; Chen, Jia; Xia, Yu-Gui; Xu, Qiang

    2005-03-01

    In our previous study, quercetin was found to induce apoptosis of murine melanoma B16-BL6 cells. The cellular and molecular mechanism of quercetin-induced apoptosis was investigated in the present study. Nuclear morphology was determined by fluorescence microscopy. DNA fragmentation was analyzed by electrophoresis and quantified by the diphenylamine method. The transmembrane potential of mitochondria was measured by flow cytometry. Bcl-2, Bcl-X(L), PKC-alpha, PKC-beta, and PKC-delta were detected by Western blotting. Caspase activity was determined spectrophotometrically. Quercetin induced the condensation of nuclei of B16-BL6 cells in a dose-dependent pattern as visualized by Hoechst 33258 and propidium iodide dying. Phorbol 12-myristate 13-acetate (PMA), a PKC activator, significantly enhanced apoptosis induced by quercetin, while doxorubicin, a PKC inhibitor, markedly decreased it. Both PMA and doxorubicin showed a consistent effect on the fragmentation of nuclear DNA caused by various dosages of quercetin. Quercetin dose-dependently led to loss of the mitochondrial membrane potential, which was also significantly reinforced or antagonized by PMA and doxorubicin, respectively. Moreover, PMA showed reinforcement, while doxorubicin showed significant antagonization, of the quercetin-mediated decrease in the expression of Bcl-2. Quercetin promoted caspase-3 activity in a dose-dependent manner, which was also regulated by PMA and doxorubicin with a pattern similar to that seen in their effect on apoptosis, mitochondrial membrane potential and Bcl-2 expression, but none of these were directly affected by PMA and doxorubicin. Free fatty acid and chlorpromazine, a PKC activator and inhibitor, respectively, did not interfere with these effects of quercetin. B16-BL6 cells expressed PKC-alpha, PKC-beta, and PKC-delta. Quercetin dose-dependently inhibited the expression of PKC-alpha but not that of PKC-beta and PKC-delta. Doxorubicin almost completely blocked the effect of

  3. CDB-4124, a progesterone receptor modulator, inhibits mammary carcinogenesis by suppressing cell proliferation and inducing apoptosis.

    Science.gov (United States)

    Wiehle, Ronald; Lantvit, Daniel; Yamada, Tohru; Christov, Konstantin

    2011-03-01

    CDB-4124 (Proellex or telapristone acetate) is a modulator of progesterone receptor (PR) signaling, which is currently employed in preclinical studies for prevention and treatment of breast cancer and has been used in clinical studies for treatment of uterine fibroids and endometriosis. Here we provide evidence for its action on steroid hormone-signaling, cell cycle-regulated genes and in vivo on mammary carcinogenesis. When CDB-4124 is given to rats at 200 mg/kg for 24 months, it prevents the development of spontaneous mammary hyperplastic and premalignant lesions. Also, CDB-4124 given as subcutaneous pellets at two different doses suppressed, dose dependently, N-methyl-N-nitrosourea (MNU)-induced mammary carcinogenesis. The high dose (30 mg, over 84 days) increased tumor latency from 66 ± 24 days to 87 ± 20 days (P CDB-4124 inhibited cell proliferation and induced apoptosis in MNU-induced mammary tumors, which correlated with a decreased proportion of PR(+) tumor cells and with decreased serum progesterone. CDB-4124 did not affect serum estradiol. In a mechanistic study employing T47D cells we found that CDB-4124 suppressed G(1)/G(0)-S transition by inhibiting CDK2 and CDK4 expressions, which correlated with inhibition of estrogen receptor (ER) expression. Taken together, these data indicate that CDB-4124 can suppress the development of precancerous lesions and carcinogen-induced ER(+) mammary tumors in rats, and may have implications for prevention and treatment of human breast cancer.

  4. A preliminary study on action mechanisms of surviving expression in cell apoptosis induced by high-LET radiation

    International Nuclear Information System (INIS)

    Jin Xiaodong; Li Qiang; Gong Li; Wu Qingfeng; Li Ping; Dai Zhongying; Liu Xinguo; Tao Jiajun

    2010-01-01

    It has been proven that over-expression of surviving in cancerous cell lines is related to the radioresistance of cells to high-LET radiation in previous work. In this study, action mechanisms of surviving gene in apoptosis induced by high-LET radiation were investigated. We found that inhibiting surviving by siRNA had no notable influence on Bcl-2 and Bax expressions induced by carbon ions. Surviving depressed cell apoptosis through the inhibition of the activities of caspase-3 and -9 possibly in cell apoptosis induced by high-LET radiation. (authors)

  5. Caffeic Acid Induces Apoptosis in Human Cervical Cancer Cells Through the Mitochondrial Pathway

    Directory of Open Access Journals (Sweden)

    Wei-Chun Chang

    2010-12-01

    Conclusion: Caffeic acid induces apoptosis by inhibiting Bcl-2 activity, leading to release of cytochrome c and subsequent activation of caspase-3, indicating that caffeic acid induces apoptosis via the mitochondrial apoptotic pathway. This also suggests that caffeic acid has a strong anti-tumor effect and may be a promising chemopreventive or chemotherapeutic agent.

  6. Inhibition of Cartilage Acidic Protein 1 Reduces Ultraviolet B Irradiation Induced-Apoptosis through P38 Mitogen-Activated Protein Kinase and Jun Amino-Terminal Kinase Pathways

    Directory of Open Access Journals (Sweden)

    Yinghong Ji

    2016-11-01

    Full Text Available Background/Aims: Ultraviolet B (UVB irradiation can easily induce apoptosis in human lens epithelial cells (HLECs and further lead to various eye diseases including cataract. Here for the first time, we investigated the role of cartilage acidic protein 1 (CRTAC1 gene in UVB irradiation induced-apoptosis in HLECs. Methods: Three groups of HLECs were employed including model group, empty vector group, and CRTAC1 interference group. Results: After UVB irradiation, the percentage of primary apoptotic cells was obviously fewer in CRTAC1 interference group. Meanwhile, inhibition of CRTAC1 also reduced both reactive oxygen species (ROS production and intracellular Ca2+ concentration, but the level of mitochondrial membrane potential (Δψm was increased in HLECs. Further studies indicated that superoxide dismutase (SOD activity and total antioxidative (T-AOC level were significantly increased in CRTAC1-inhibited cells, while the levels of malondialdehyde (MDA and lactate dehydrogenase (LDH were significantly decreased. ELISA analysis of CRTAC1-inhibited cells showed that the concentrations of tumor necrosis factor-α (TNF-α and interleukin-6 (IL-6 were significantly decreased, but the concentration of interleukin-10 (IL-10 was significantly increased. Western blot analyses of eight apoptosis-associated proteins including Bax, Bcl-2, p38, phospho-p38 (p-p38, Jun amino-terminal kinases (JNK1/2, phospho-JNK1/2 (p-JNK1/2, calcium-sensing receptor (CasR, and Ca2+/calmodulin-dependent protein kinase II (CaMKII indicated that the inhibition of CRTAC1 alleviated oxidative stress and inflammation response, inactivated calcium-signaling pathway, p38 and JNK1/2 signal pathways, and eventually reduced UVB irradiation induced-apoptosis in HLECs. Conclusion: These results provided new insights into the mechanism of cataract development, and demonstrated that CRTAC1 could be a potentially novel target for cataract treatment.

  7. Inhibition of Cartilage Acidic Protein 1 Reduces Ultraviolet B Irradiation Induced-Apoptosis through P38 Mitogen-Activated Protein Kinase and Jun Amino-Terminal Kinase Pathways.

    Science.gov (United States)

    Ji, Yinghong; Rong, Xianfang; Li, Dan; Cai, Lei; Rao, Jun; Lu, Yi

    2016-01-01

    Ultraviolet B (UVB) irradiation can easily induce apoptosis in human lens epithelial cells (HLECs) and further lead to various eye diseases including cataract. Here for the first time, we investigated the role of cartilage acidic protein 1 (CRTAC1) gene in UVB irradiation induced-apoptosis in HLECs. Three groups of HLECs were employed including model group, empty vector group, and CRTAC1 interference group. After UVB irradiation, the percentage of primary apoptotic cells was obviously fewer in CRTAC1 interference group. Meanwhile, inhibition of CRTAC1 also reduced both reactive oxygen species (ROS) production and intracellular Ca2+ concentration, but the level of mitochondrial membrane potential (Δψm) was increased in HLECs. Further studies indicated that superoxide dismutase (SOD) activity and total antioxidative (T-AOC) level were significantly increased in CRTAC1-inhibited cells, while the levels of malondialdehyde (MDA) and lactate dehydrogenase (LDH) were significantly decreased. ELISA analysis of CRTAC1-inhibited cells showed that the concentrations of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were significantly decreased, but the concentration of interleukin-10 (IL-10) was significantly increased. Western blot analyses of eight apoptosis-associated proteins including Bax, Bcl-2, p38, phospho-p38 (p-p38), Jun amino-terminal kinases (JNK1/2), phospho-JNK1/2 (p-JNK1/2), calcium-sensing receptor (CasR), and Ca2+/calmodulin-dependent protein kinase II (CaMKII) indicated that the inhibition of CRTAC1 alleviated oxidative stress and inflammation response, inactivated calcium-signaling pathway, p38 and JNK1/2 signal pathways, and eventually reduced UVB irradiation induced-apoptosis in HLECs. These results provided new insights into the mechanism of cataract development, and demonstrated that CRTAC1 could be a potentially novel target for cataract treatment. © 2016 The Author(s) Published by S. Karger AG, Basel.

  8. Reduced RAC1 activity inhibits cell proliferation and induces apoptosis in neurofibromatosis type 2(NF2)-associated schwannoma.

    Science.gov (United States)

    Wang, Ying; Wang, Bo; Li, Peng; Zhang, Qi; Liu, Pinan

    2017-12-01

    Objective To study the function and potential mechanism of RAC1 inhibitors in NF2-associated schwannoma. Methods In this study, we the downregulation of RAC1 activity and tumor cell phenotypes by RAC1 inhibitor NSC23766 in vitro. And we further validated the anti-proliferation effect by this RAC1 inhibitor in subcutaneous xenograft tumor model and sciatic nerve model. Results Pharmacological inhibition of RAC1 could significantly inhibit the proliferation of both RT4 cells and human NF2-associated primary schwannoma cells by inducing apoptosis. Pharmacological inhibition of RAC1 effectively reduced Rac1 activity and down-regulated the pathway downstream of Rac. Moreover, pharmacological inhibition of RAC1 showed a potential antitumor effect, with low toxicity in vivo. Conclusion RAC1 inhibitors may play a therapeutic role in patients with schwannoma.

  9. Essential roles of caspases and their upstream regulators in rotenone-induced apoptosis

    International Nuclear Information System (INIS)

    Lee Jihjong; Huang, M.-S.; Yang, I-C.; Lai, T.-C.; Wang, J.-L.; Pang, V.F.; Hsiao, M.; Kuo, M.Y.P.

    2008-01-01

    In the present study, we examined whether caspases and their upstream regulators are involved in rotenone-induced cytotoxicity. Rotenone significantly inhibited the proliferation of oral cancer cell lines in a dose-dependent manner compared to normal oral mucosal fibroblasts. Flow cytometric analysis of DNA content showed that rotenone treatment induced apoptosis following G2/M arrest. Western blotting showed activation of both the caspase-8 and caspase-9 pathways, which differed from previous studies conducted in other cell types. Furthermore, p53 protein and its downstream pro-apoptotic target, Bax, were induced in SAS cells after treatment with rotenone. Rotenone-induced apoptosis was inhibited by antioxidants (glutathione, N-acetylcysteine, and tiron). In conclusion, our results demonstrate significant involvement of caspases and their upstream regulators in rotenone-induced cytotoxicity

  10. Mechanical stimulation of C2C12 cells increases m-calpain expression, focal adhesion plaque protein degradation

    DEFF Research Database (Denmark)

    Grossi, Alberto; Karlsson, Anders H; Lawson, Moira Ann

    2008-01-01

    . Stimulation due to stretch- or load-induced signaling is now beginning to be understood as a factor which affects gene sequences, protein synthesis and an increase in Ca2+ influx in myocytes. Evidence of the involvement of Ca2+ -dependent activity in myoblast fusion, cell membrane and cytoskeleton component...... reorganization due to the activity of the ubiquitous proteolytic enzymes, calpains, has been reported. Whether there is a link between stretch- or load-induced signaling and calpain expression and activation is not known. Using a magnetic bead stimulation assay and C2C12 mouse myoblasts cell population, we have...... demonstrated that mechanical stimulation via laminin receptors leads to an increase in m-calpain expression, but no increase in the expression of other calpain isoforms. Our study revealed that after a short period of stimulation, m-calpain relocates into focal adhesion complexes and is followed by a breakdown...

  11. Reactive oxygen species-dependent HSP90 protein cleavage participates in arsenical As+3- and MMA+3-induced apoptosis through inhibition of telomerase activity via JNK activation

    International Nuclear Information System (INIS)

    Shen, S.-C.; Yang, L.-Y.; Lin, H.-Y.; Wu, C.-Y.; Su, T.-H.; Chen, Y.-C.

    2008-01-01

    The effects of six arsenic compounds including As +3 , MMA +3 , DMA +3 , As +5 , MMA +5 , and DMA +5 on the viability of NIH3T3 cells were examined. As +3 and MMA +3 , but not the others, exhibited significant cytotoxic effects in NIH3T3 cells through apoptosis induction. The apoptotic events such as DNA fragmentation and chromosome condensation induced by As +3 and MMA +3 were prevented by the addition of NAC and CAT, and induction of HO-1 gene expression in accordance with cleavage of the HSP90 protein, and suppression of telomerase activity were observed in NIH3T3 cells under As +3 and MMA +3 treatments. An increase in the intracellular peroxide level was examined in As +3 - and MMA +3 -treated NIH3T3 cells, and As +3 - and MMA +3 -induced apoptotic events were blocked by NAC, CAT, and DPI addition. HSP90 inhibitors, GA and RD, significantly attenuated the telomerase activity in NIH3T3 cells with an enhancement of As +3 - and MMA +3 -induced cytotoxicity. Suppression of JNKs significantly inhibited As +3 - and MMA +3 -induced apoptosis by blocking HSP90 protein cleavage and telomerase reduction in NIH3T3 cells. Furthermore, Hb, SnPP, and dexferosamine showed no effect against As +3 - and MMA +3 -induced apoptosis, and overexpression of HO-1 protein or inhibition of HO-1 protein expression did not affect the apoptosis induced by As +3 or MMA +3 . These data provide the first evidence to indicate that apoptosis induced by As +3 and MMA +3 is mediated by an ROS-dependent degradation of HSP90 protein and reduction of telomerase via JNK activation, and HO-1 induction might not be involved

  12. EGFR‑associated pathways involved in traditional Chinese medicine (TCM)‑1‑induced cell growth inhibition, autophagy and apoptosis in prostate cancer.

    Science.gov (United States)

    Wu, Zhaomeng; Zhu, Qingyi; Zhang, Yu; Yin, Yingying; Kang, Dan; Cao, Runyi; Tian, Qian; Lu, Shan; Liu, Ping

    2018-06-01

    Traditional Chinese medicine (TCM) has the synergistic effect of the combination of a single ingredient and a monomer, and systemic and local therapeutic effects in cancer treatment, through which TCM is able to enhance the curative effect and reduce the side effects. The present study analyzed the effect of TCM‑1 (an anti‑cancer TCM) on prostate cancer (PCa) cell lines, and studied in detail the mechanism of cell death induced by TCM‑1 in vitro and in vivo. From the present results, it was identified for the first time, to the best of our knowledge, that TCM‑1 arrested the cell cycle at the G1 phase, decreased cell viability and increased nuclear rupture in a dose‑dependent manner; these effects finally resulted in apoptosis in PCa cells. At the molecular level, the data demonstrated that TCM‑1 competitively acted on epidermal growth factor receptor (EGFR) with EGF, and suppressed the auto‑phosphorylation and activity of EGFR. Inhibition of EGFR further suppressed the downstream phosphatidylinositol 3‑kinase (PI3K)/RAC‑α serine/threonine‑protein kinase (AKT) and RAF proto‑oncogene serine/threonine‑protein kinase/extracellular signal regulated kinase signaling pathways and resulted in a decrease in the phosphorylated‑forkhead box protein O1 (at Ser256, Thr24 and Ser319) expression level, and induced cell growth inhibition and apoptosis by regulating the expression of apoptosis‑and cell cycle‑associated genes. In addition, TCM‑1 markedly inhibited the PI3K/AKT/serine/threonine‑protein kinase mTOR signaling pathway and induced cell autophagy by downregulating the phosphorylation of p70S6K and upregulating the levels of Beclin‑1 and microtubule‑associated protein light chain‑3II. In vivo, the TCM‑1‑treated group exhibited a significant decrease in tumor volume compared with the negative control group in subcutaneous xenograft nude mice by inhibiting EGFR‑associated signaling pathways. Therefore, the bio‑functions of

  13. Sangivamycin induces apoptosis by suppressing Erk signaling in primary effusion lymphoma cells

    International Nuclear Information System (INIS)

    Wakao, Kazufumi; Watanabe, Tadashi; Takadama, Tadatoshi; Ui, Sadaharu; Shigemi, Zenpei; Kagawa, Hiroki; Higashi, Chizuka; Ohga, Rie; Taira, Takahiro; Fujimuro, Masahiro

    2014-01-01

    Highlights: • Sangivamycin induces the apoptosis of B cell lymphoma PEL cells. • Sangivamycin suppresses Erk signaling by inhibiting Erk phosphorylation in PEL cells. • The activation of Erk signaling is essential for PEL cell survival. • Sangivamycin induces the apoptosis of PEL cells without production of progeny virus. • Sangivamycin may serve as a novel drug for the treatment of PEL. - Abstract: Sangivamycin, a structural analog of adenosine and antibiotic exhibiting antitumor and antivirus activities, inhibits protein kinase C and the synthesis of both DNA and RNA. Primary effusion lymphoma (PEL) is an aggressive neoplasm caused by Kaposi’s sarcoma-associated herpesvirus (KSHV) in immunosuppressed patients and HIV-infected homosexual males. PEL cells are derived from post-germinal center B cells, and are infected with KSHV. Herein, we asked if sangivamycin might be useful to treat PEL. We found that sangivamycin killed PEL cells, and we explored the underlying mechanism. Sangivamycin treatment drastically decreased the viability of PEL cell lines compared to KSHV-uninfected B lymphoma cell lines. Sangivamycin induced the apoptosis of PEL cells by activating caspase-7 and -9. Further, sangivamycin suppressed the phosphorylation of Erk1/2 and Akt, thus inhibiting activation of the proteins. Inhibitors of Akt and MEK suppressed the proliferation of PEL cells compared to KSHV-uninfected cells. It is known that activation of Erk and Akt signaling inhibits apoptosis and promotes proliferation in PEL cells. Our data therefore suggest that sangivamycin induces apoptosis by inhibiting Erk and Akt signaling in such cells. We next investigated whether sangivamycin, in combination with an HSP90 inhibitor geldanamycin (GA) or valproate (valproic acid), potentiated the cytotoxic effects of the latter drugs on PEL cells. Compared to treatment with GA or valproate alone, the addition of sangivamycin enhanced cytotoxic activity. Our data thus indicate that

  14. Sangivamycin induces apoptosis by suppressing Erk signaling in primary effusion lymphoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Wakao, Kazufumi [Department of Biotechnology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Kofu-shi 400-8511 (Japan); Watanabe, Tadashi [Department of Cell Biology, Kyoto Pharmaceutical University, Misasagi-Shichonocho 1, Yamashinaku, Kyoto 607-8412 (Japan); Takadama, Tadatoshi; Ui, Sadaharu [Department of Biotechnology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Kofu-shi 400-8511 (Japan); Shigemi, Zenpei; Kagawa, Hiroki [Department of Cell Biology, Kyoto Pharmaceutical University, Misasagi-Shichonocho 1, Yamashinaku, Kyoto 607-8412 (Japan); Higashi, Chizuka; Ohga, Rie; Taira, Takahiro [Department of Molecular Cell Biology, Faculty of Medicine, University of Yamanashi, Chuoh-shi 409-3898 (Japan); Fujimuro, Masahiro, E-mail: fuji2@mb.kyoto-phu.ac.jp [Department of Cell Biology, Kyoto Pharmaceutical University, Misasagi-Shichonocho 1, Yamashinaku, Kyoto 607-8412 (Japan)

    2014-02-07

    Highlights: • Sangivamycin induces the apoptosis of B cell lymphoma PEL cells. • Sangivamycin suppresses Erk signaling by inhibiting Erk phosphorylation in PEL cells. • The activation of Erk signaling is essential for PEL cell survival. • Sangivamycin induces the apoptosis of PEL cells without production of progeny virus. • Sangivamycin may serve as a novel drug for the treatment of PEL. - Abstract: Sangivamycin, a structural analog of adenosine and antibiotic exhibiting antitumor and antivirus activities, inhibits protein kinase C and the synthesis of both DNA and RNA. Primary effusion lymphoma (PEL) is an aggressive neoplasm caused by Kaposi’s sarcoma-associated herpesvirus (KSHV) in immunosuppressed patients and HIV-infected homosexual males. PEL cells are derived from post-germinal center B cells, and are infected with KSHV. Herein, we asked if sangivamycin might be useful to treat PEL. We found that sangivamycin killed PEL cells, and we explored the underlying mechanism. Sangivamycin treatment drastically decreased the viability of PEL cell lines compared to KSHV-uninfected B lymphoma cell lines. Sangivamycin induced the apoptosis of PEL cells by activating caspase-7 and -9. Further, sangivamycin suppressed the phosphorylation of Erk1/2 and Akt, thus inhibiting activation of the proteins. Inhibitors of Akt and MEK suppressed the proliferation of PEL cells compared to KSHV-uninfected cells. It is known that activation of Erk and Akt signaling inhibits apoptosis and promotes proliferation in PEL cells. Our data therefore suggest that sangivamycin induces apoptosis by inhibiting Erk and Akt signaling in such cells. We next investigated whether sangivamycin, in combination with an HSP90 inhibitor geldanamycin (GA) or valproate (valproic acid), potentiated the cytotoxic effects of the latter drugs on PEL cells. Compared to treatment with GA or valproate alone, the addition of sangivamycin enhanced cytotoxic activity. Our data thus indicate that

  15. (4-Methoxyphenyl)(3,4,5-trimethoxyphenyl)methanone inhibits tubulin polymerization, induces G{sub 2}/M arrest, and triggers apoptosis in human leukemia HL-60 cells

    Energy Technology Data Exchange (ETDEWEB)

    Magalhães, Hemerson I.F. [Departamento de Fisiologia e Farmacologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, Ceará (Brazil); Centro de Ciências da Saúde, Departamento de Ciências Farmacêuticas, Universidade Federal da Paraíba, João Pessoa, Paraíba (Brazil); Wilke, Diego V. [Departamento de Fisiologia e Farmacologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, Ceará (Brazil); Bezerra, Daniel P., E-mail: danielpbezerra@gmail.com [Centro de Pesquisa Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Bahia (Brazil); Cavalcanti, Bruno C. [Departamento de Fisiologia e Farmacologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, Ceará (Brazil); Rotta, Rodrigo; Lima, Dênis P. de; Beatriz, Adilson [Centro de Ciências Exatas e Tecnológicas (Laboratório LP4), Universidade Federal do Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul (Brazil); Moraes, Manoel O.; Diniz-Filho, Jairo [Departamento de Fisiologia e Farmacologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, Ceará (Brazil); Pessoa, Claudia, E-mail: c_pessoa@yahoo.com [Departamento de Fisiologia e Farmacologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, Ceará (Brazil)

    2013-10-01

    (4-Methoxyphenyl)(3,4,5-trimethoxyphenyl)methanone (PHT) is a known cytotoxic compound belonging to the phenstatin family. However, the exact mechanism of action of PHT-induced cell death remains to be determined. The aim of this study was to investigate the mechanisms underlying PHT-induced cytotoxicity. We found that PHT displayed potent cytotoxicity in different tumor cell lines, showing IC{sub 50} values in the nanomolar range. Cell cycle arrest in G{sub 2}/M phase along with the augmented metaphase cells was found. Cells treated with PHT also showed typical hallmarks of apoptosis such as cell shrinkage, chromatin condensation, phosphatidylserine exposure, increase of the caspase 3/7 and 8 activation, loss of mitochondrial membrane potential, and internucleosomal DNA fragmentation without affecting membrane integrity. Studies conducted with isolated tubulin and docking models confirmed that PHT binds to the colchicine site and interferes in the polymerization of microtubules. These results demonstrated that PHT inhibits tubulin polymerization, arrests cancer cells in G{sub 2}/M phase of the cell cycle, and induces their apoptosis, exhibiting promising anticancer therapeutic potential. - Highlights: • PHT inhibits tubulin polymerization. • PHT arrests cancer cells in G{sub 2}/M phase of the cell cycle. • PHT induces caspase-dependent apoptosis.

  16. Anti-tumor activities of luteolin and silibinin in glioblastoma cells: overexpression of miR-7-1-3p augmented luteolin and silibinin to inhibit autophagy and induce apoptosis in glioblastoma in vivo.

    Science.gov (United States)

    Chakrabarti, Mrinmay; Ray, Swapan K

    2016-03-01

    Glioblastoma is the deadliest brain tumor in humans. High systemic toxicity of conventional chemotherapies prompted the search for natural compounds for controlling glioblastoma. The natural flavonoids luteolin (LUT) and silibinin (SIL) have anti-tumor activities. LUT inhibits autophagy, cell proliferation, metastasis, and angiogenesis and induces apoptosis; while SIL activates caspase-8 cascades to induce apoptosis. However, synergistic anti-tumor effects of LUT and SIL in glioblastoma remain unknown. Overexpression of tumor suppressor microRNA (miR) could enhance the anti-tumor effects of LUT and SIL. Here, we showed that 20 µM LUT and 50 µM SIL worked synergistically for inhibiting growth of two different human glioblastoma U87MG (wild-type p53) and T98G (mutant p53) cell lines and natural combination therapy was more effective than conventional chemotherapy (10 µM BCNU or 100 µM TMZ). Combination of LUT and SIL caused inhibition of growth of glioblastoma cells due to induction of significant amounts of apoptosis and complete inhibition of invasion and migration. Further, combination of LUT and SIL inhibited rapamycin (RAPA)-induced autophagy, a survival mechanism, with suppression of PKCα and promotion of apoptosis through down regulation of iNOS and significant increase in expression of the tumor suppressor miR-7-1-3p in glioblastoma cells. Our in vivo studies confirmed that overexpression of miR-7-1-3p augmented anti-tumor activities of LUT and SIL in RAPA pre-treated both U87MG and T98G tumors. In conclusion, our results clearly demonstrated that overexpression of miR-7-1-3p augmented the anti-tumor activities of LUT and SIL to inhibit autophagy and induce apoptosis for controlling growth of different human glioblastomas in vivo.

  17. Pretreatment with Pancaspase Inhibitor (Z-VAD-FMK Delays but Does Not Prevent Intraperitoneal Heat-Killed Group B Streptococcus-Induced Preterm Delivery in a Pregnant Mouse Model

    Directory of Open Access Journals (Sweden)

    Ozlem Equils

    2009-01-01

    Full Text Available Caspases and apoptosis are thought to play a role in infection-associated preterm-delivery. We have shown that in vitro treatment with pancaspase inhibitor Z-VAD-FMK protects trophoblasts from microbial antigen-induced apoptosis. Objective. To examine whether in vivo administration of Z-VAD-FMK would prevent infection-induced preterm-delivery. Methods. We injected 14.5 day-pregnant-mice with heat-killed group B streptococcus (HK-GBS. Apoptosis within placentas and membranes was assessed by TUNEL staining. Calpain expression and caspase-3 activation were assessed by immunohistochemistry. Preterm-delivery was defined as expulsion of a fetus within 48 hours after injection. Results. Intrauterine (i.u. or intraperitoneal (i.p. HK-GBS injection led to preterm-delivery and induced apoptosis in placentas and membranes at 14 hours. The expression of calpain, a caspase-independent inducer of apoptosis, was increased in placenta. Treatment with the specific caspase inhibitor Z-VAD-FMK (i.p. prior to HK-GBS (i.p. delayed but did not prevent preterm-delivery. Conclusion. Caspase-dependent apoptosis appears to play a role in the timing but not the occurrence of GBS-induced preterm delivery in the mouse.

  18. Periostin inhibits mechanical stretch-induced apoptosis in osteoblast-like MG-63 cells.

    Science.gov (United States)

    Yu, Kai-Wen; Yao, Chung-Chen; Jeng, Jiiang-Huei; Shieh, Hao-Ying; Chen, Yi-Jane

    2018-04-01

    Appropriate mechanical stress plays an important role in regulating the proliferation and differentiation of osteoblasts, whereas high-level mechanical stress may be harmful and compromise cell survival. Periostin, a matricellular protein, is essential in maintaining functional integrity of bone and collagen-rich connective tissue in response to mechanical stress. This study investigated whether or not high-level mechanical stretch induces cell apoptosis and the regulatory role of periostin in mechanical stretch-induced apoptosis in osteoblastic cells. Osteoblast-like MG-63 cells were seeded onto Bio-Flex I culture plates and subjected to cyclic mechanical stretching (15% elongation, 0.1 Hz) in a Flexercell tension plus system-5000. The same process was applied to cells pre-treated with exogenous human recombinant periostin before mechanical stretching. We used a chromatin condensation and membrane permeability dead cell apoptosis kit to evaluate the stretch-induced cell responses. Expression of caspase-3 and cPARP was examined by immunofluorescent stain and flow cytometry. The expression of periostin in MG-63 cells is involved in the TGF-β signaling pathway. High-level cyclic mechanical stretch induced apoptotic responses in MG-63 osteoblastic cells. The percentages of apoptotic cells and cells expressing cPARP protein increased in the groups of cells subjected to mechanical stretch, but these responses were absent in the presence of exogenous periostin. Our study revealed that high-level mechanical stretch induces apoptotic cell death, and that periostin plays a protective role against mechanical stretch-induced apoptosis in osteoblastic cells. Copyright © 2017. Published by Elsevier B.V.

  19. Andrographolide sensitizes prostate cancer cells to TRAIL-induced apoptosis

    Directory of Open Access Journals (Sweden)

    Ruo-Jing Wei

    2018-01-01

    Full Text Available Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL is a promising agent for anticancer therapy. The identification of small molecules that can establish the sensitivity of prostate cancer (PCa cells to TRAIL-induced apoptosis is crucial for the targeted treatment of PCa. PC3, DU145, JAC-1, TsuPr1, and LNCaP cells were treated with Andrographolide (Andro and TRAIL, and the apoptosis was measured using the Annexin V/PI double staining method. Real time-polymerase chain reaction (PCR and Western blot analysis were performed to measure the expression levels of target molecules. RNA interference technique was used to down-regulate the expression of the target protein. We established a nude mouse xenograft model of PCa, which was used to measure the caspase-3 activity in the tumor cells using flow cytometry. In this research study, our results demonstrated that Andro preferentially increased the sensitivity of PCa cells to TRAIL-induced apoptosis at subtoxic concentrations, and the regulation mechanism was related to the up-regulation of DR4. In addition, it also increased the p53 expression and led to the generation of reactive oxygen species (ROS in the cells. Further research revealed that the DR4 inhibition, p53 expression, and ROS generation can significantly reduce the apoptosis induced by the combination of TRAIL and Andro in PCa cells. In conclusion, Andro increases the sensitivity of PCa cells to TRAIL-induced apoptosis through the generation of ROS and up-regulation of p53 and then promotes PCa cell apoptosis associated with the activation of DR4.

  20. JS-K promotes apoptosis by inducing ROS production in human prostate cancer cells.

    Science.gov (United States)

    Qiu, Mingning; Chen, Lieqian; Tan, Guobin; Ke, Longzhi; Zhang, Sai; Chen, Hege; Liu, Jianjun

    2017-03-01

    Reactive oxygen species (ROS) are chemical species that alter redox status, and are responsible for inducing carcinogenesis. The purpose of the present study was to assess the effects of the glutathione S transferase-activated nitric oxide donor prodrug, JS-K, on ROS accumulation and on proliferation and apoptosis in human prostate cancer cells. Cell proliferation and apoptosis, ROS accumulation and the activation of the mitochondrial signaling pathway were measured. The results demonstrated that JS-K may inhibit prostate cancer cell growth in a dose- and time-dependent manner, and induce ROS accumulation and apoptosis in a dose-dependent manner. With increasing concentrations of JS-K, expression of pro-apoptotic proteins increased, but Bcl-2 expression decreased. Additionally, the antioxidant N-acetylcysteine reversed JS-K-induced cell apoptosis; conversely, the pro-oxidant glutathione disulfide exacerbated JS-K-induced apoptosis. In conclusion, the data suggest that JS-K induces prostate cancer cell apoptosis by increasing ROS levels.

  1. Inhibition of NF-κB by a cell permeable form of IκBα induces apoptosis in eosinophils

    International Nuclear Information System (INIS)

    Fujihara, Satoko; Jaffray, Ellis; Farrow, Stuart N.; Rossi, Adriano G.; Haslett, Christopher; Hay, Ronald T.

    2005-01-01

    An 11 amino acid HIV-TAT peptide can deliver target proteins into a variety of cells in a receptor-independent manner. To generate a highly specific inhibitor of the transcription factor NF-κB, we have fused the TAT-peptide to a version of IκBα that is resistant to signal-induced degradation. TAT-IκBα(S32A, S36A) inhibited NF-κB-dependent transcription in HeLa and A549 cells by retaining NF-κB p65 in the cytoplasm. Introduction of TAT-IκBα(S32A, S36A) into human eosinophils inhibited the nuclear translocation of NF-κB and induced apoptosis. Thus, continuous NF-κB-dependent transcription is important for eosinophil survival. While eosinophils are normally refractive to standard methods of gene delivery, the ability of TAT fusion proteins to be taken up by these cells should enable a detailed molecular analysis of survival pathways in these cells

  2. Quercetin enhances hypoxia-mediated apoptosis via direct inhibition of AMPK activity in HCT116 colon cancer.

    Science.gov (United States)

    Kim, Hak-Su; Wannatung, Tirawat; Lee, Sooho; Yang, Woo Kyeom; Chung, Sung Hyun; Lim, Jong-Seok; Choe, Wonchae; Kang, Insug; Kim, Sung-Soo; Ha, Joohun

    2012-09-01

    Tumor hypoxia is considered the best validated target in clinical oncology because of its significant contribution to chemotherapy failure and drug resistance. As an approach to target hypoxia, we assessed the potential of quercetin, a flavonoid widely distributed in plants, as a anticancer agent under hypoxic conditions and examined its pharmacological mechanisms by primarily focusing on the role of AMP-activated protein kinase (AMPK). Quercetin significantly attenuated tumor growth in an HCT116 cancer xenograft in vivo model with a substantial reduction of AMPK activity. In a cell culture system, quercetin more dramatically induced apoptosis of HCT116 cancer cells under hypoxic conditions than normoxic conditions, and this was tightly associated with inhibition of hypoxia-induced AMPK activity. An in vitro kinase assay demonstrated that quercetin directly inhibits AMPK activity. Inhibition of AMPK by expressing a dominant-negative form resulted in an increase of apoptosis under hypoxia, and a constitutively active form of AMPK effectively blocked quercetin-induced apoptosis under hypoxia. Collectively, our data suggest that quercetin directly inhibits hypoxia-induced AMPK, which plays a protective role against hypoxia. Quercetin also reduced the activity of hypoxia-inducible factor-1 (HIF-1), a major transcription factor for adaptive cellular response to hypoxia. Moreover, quercetin sensitized HCT116 cancer cells to the anticancer drugs cisplatin and etoposide under hypoxic conditions. Our findings suggest that AMPK may serve as a novel target for overcoming tumor hypoxia-associated negative aspects.

  3. E2/ER β Enhances Calcineurin Protein Degradation and PI3K/Akt/MDM2 Signal Transduction to Inhibit ISO-Induced Myocardial Cell Apoptosis

    Directory of Open Access Journals (Sweden)

    Kuan-Ho Lin

    2017-04-01

    Full Text Available Secretion of multifunctional estrogen and its receptor has been widely considered as the reason for markedly higher frequency of heart disease in men than in women. 17β-Estradiol (E2, for instance, has been reported to prevent development of cardiac apoptosis via activation of estrogen receptors (ERs. In addition, protein phosphatase such as protein phosphatase 1 (PP1 and calcineurin (PP2B are also involved in cardiac hypertrophy and cell apoptosis signaling. However, the mechanism by which E2/ERβ suppresses apoptosis is not fully understood, and the role of protein phosphatase in E2/ERβ action also needs further investigation. In this study, we observed that E2/ERβ inhibited isoproterenol (ISO-induced myocardial cell apoptosis, cytochrome c release and downstream apoptotic markers. Moreover, we found that E2/ERβ blocks ISO-induced apoptosis in H9c2 cells through the enhancement of calcineurin protein degradation through PI3K/Akt/MDM2 signaling pathway. Our results suggest that supplementation with estrogen and/or overexpression of estrogen receptor β gene may prove to be effective means to treat stress-induced myocardial damage.

  4. Degradation of Epidermal Growth Factor Receptor Mediates Dasatinib-Induced Apoptosis in Head and Neck Squamous Cell Carcinoma Cells

    Directory of Open Access Journals (Sweden)

    Yu-Chin Lin

    2012-06-01

    Full Text Available Epidermal growth factor receptor (EGFR is an important oncoprotein that promotes cell growth and proliferation. Dasatinib, a bcr-abl inhibitor, has been approved clinically for the treatment of chronic myeloid leukemia and demonstrated to be effective against solid tumors in vitro through Src inhibition. Here, we disclose that EGFR degradation mediated dasatinib-induced apoptosis in head and neck squamous cell carcinoma (HNSCC cells. HNSCC cells, including Ca9-22, FaDu, HSC3, SAS, SCC-25, and UMSCC1, were treated with dasatinib, and cell viability, apoptosis, and underlying signal transduction were evaluated. Dasatinib exhibited differential sensitivities against HNSCC cells. Growth inhibition and apoptosis were correlated with its inhibition on Akt, Erk, and Bcl-2, irrespective of Src inhibition. Accordingly, we found that down-regulation of EGFR was a determinant of dasatinib sensitivity. Lysosome inhibitor reversed dasatinib-induced EGFR down-regulation, and c-cbl activity was increased by dasatinib, indicating that dasatinib-induced EGFR down-regulation might be through c-cbl-mediated lysosome degradation. Increased EGFR activation by ligand administration rescued cells from dasatinib-induced apoptosis, whereas inhibition of EGFR enhanced its apoptotic effect. Estrogen receptor α (ERα was demonstrated to play a role in Bcl-2 expression, and dasatinib inhibited ERα at the pretranslational level. ERα was associated with EGFR in dasatinib-treated HNSCC cells. Furthermore, the xenograft model showed that dasatinib inhibited HSC3 tumor growth through in vivo down-regulation of EGFR and ERα. In conclusion, degradation of EGFR is a novel mechanism responsible for dasatinib-induced apoptosis in HNSCC cells.

  5. Proteasome inhibition-induced p38 MAPK/ERK signaling regulates autophagy and apoptosis through the dual phosphorylation of glycogen synthase kinase 3β

    International Nuclear Information System (INIS)

    Choi, Cheol-Hee; Lee, Byung-Hoon; Ahn, Sang-Gun; Oh, Seon-Hee

    2012-01-01

    Highlights: ► MG132 induces the phosphorylation of GSK3β Ser9 and, to a lesser extent, of GSK3β Thr390 . ► MG132 induces dephosphorylation of p70S6K Thr389 and phosphorylation of p70S6K Thr421/Ser424 . ► Inactivation of p38 dephosphorylates GSK3β Ser9 and phosphorylates GSK3β Thr390 . ► Inactivation of p38 phosphorylates p70S6K Thr389 and increases the phosphorylation of p70S6K Thr421/Ser424 . ► Inactivation of p38 decreases autophagy and increases apoptosis induced by MG132. -- Abstract: Proteasome inhibition is a promising approach for cancer treatment; however, the underlying mechanisms involved have not been fully elucidated. Here, we show that proteasome inhibition-induced p38 mitogen-activated protein kinase regulates autophagy and apoptosis by modulating the phosphorylation status of glycogen synthase kinase 3β (GSK3β) and 70 kDa ribosomal S6 kinase (p70S6K). The treatment of MDA-MB-231 cells with MG132 induced endoplasmic reticulum stress through the induction of ATF6a, PERK phosphorylation, and CHOP, and apoptosis through the cleavage of Bax and procaspase-3. MG132 caused the phosphorylation of GSK3β at Ser 9 and, to a lesser extent, Thr 390 , the dephosphorylation of p70S6K at Thr 389 , and the phosphorylation of p70S6K at Thr 421 and Ser 424 . The specific p38 inhibitor SB203080 reduced the p-GSK3β Ser9 and autophagy through the phosphorylation of p70S6K Thr389 ; however, it augmented the levels of p-ERK, p-GSK3β Thr390 , and p-70S6K Thr421/Ser424 induced by MG132, and increased apoptotic cell death. The GSK inhibitor SB216763, but not lithium, inhibited the MG132-induced phosphorylation of p38, and the downstream signaling pathway was consistent with that in SB203580-treated cells. Taken together, our data show that proteasome inhibition regulates p38/GSK Ser9 /p70S6K Thr380 and ERK/GSK3β Thr390 /p70S6K Thr421/Ser424 kinase signaling, which is involved in cell survival and cell death.

  6. Fisetin Induces Apoptosis Through p53-Mediated Up-Regulation of DR5 Expression in Human Renal Carcinoma Caki Cells.

    Science.gov (United States)

    Min, Kyoung-Jin; Nam, Ju-Ock; Kwon, Taeg Kyu

    2017-08-02

    Fisetin is a natural compound found in fruits and vegetables such as strawberries, apples, cucumbers, and onions. Since fisetin can elicit anti-cancer effects, including anti-proliferation and anti-migration, we investigated whether fisetin induced apoptosis in human renal carcinoma (Caki) cells. Fisetin markedly induced sub-G1 population and cleavage of poly (ADP-ribose) polymerase (PARP), which is a marker of apoptosis, and increased caspase activation. We found that pan-caspase inhibitor (z-VAD-fmk) inhibited fisetin-induced apoptosis. In addition, fisetin induced death receptor 5 (DR5) expression at the transcriptional level, and down-regulation of DR5 by siRNA blocked fisetin-induced apoptosis. Furthermore, fisetin induced p53 protein expression through up-regulation of protein stability, whereas down-regulation of p53 by siRNA markedly inhibited fisetin-induced DR5 expression. In contrast, fisetin induced up-regulation of CHOP expression and reactive oxygen species production, which had no effect on fisetin-induced apoptosis. Taken together, our study demonstrates that fisetin induced apoptosis through p53 mediated up-regulation of DR5 expression at the transcriptional level.

  7. Unexpected role of the L-domain of calpastatin during the autoproteolytic activation of human erythrocyte calpain.

    Science.gov (United States)

    De Tullio, Roberta; Franchi, Alice; Martines, Antonino; Averna, Monica; Pedrazzi, Marco; Melloni, Edon; Sparatore, Bianca

    2018-04-26

    Autoproteolysis of human erythrocyte calpain-1 proceeds in vitro at high [Ca 2+ ], through the conversion of the 80-kDa catalytic subunit into a 75-kDa activated enzyme that requires lower [Ca 2+ ] for catalysis. Importantly, here we detect a similar 75 kDa calpain-1 form also in vivo , in human meningiomas. Although calpastatin is so far considered the specific inhibitor of calpains, we have previously identified in rat brain a calpastatin transcript truncated at the end of the L-domain (cast110, L-DOM), coding for a protein lacking the inhibitory units. Aim of the present study was to characterize the possible biochemical role of the L-DOM during calpain-1 autoproteolysis in vitro , at high (100 µM) and low (5 µM) [Ca 2+ ]. Here we demonstrate that the L-DOM binds the 80 kDa proenzyme in the absence of Ca 2+ Consequently, we have explored the ability of the 75 kDa activated protease to catalyze at 5 µM Ca 2+ the intermolecular activation of native calpain-1 associated with the L-DOM. Notably, this [Ca 2+ ] is too low to promote the autoproteolytic activation of calpain-1 but enough to support the catalysis of the 75 kDa calpain. We show for the first time that the L-DOM preserves native calpain-1 from the degradation mediated by the 75 kDa form. Taken together, our data suggest that the free L-domain of calpastatin is a novel member of the calpain/calpastatin system endowed with a function alternative to calpain inhibition. For this reason, it will be crucial to define the intracellular relevance of the L-domain in controlling calpain activation/activity in physiopathological conditions having altered Ca 2+ homeostasis. © 2018 The Author(s).

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

    International Nuclear Information System (INIS)

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

    2003-01-01

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

  9. Dragon (Repulsive Guidance Molecule RGMb) Inhibits E-cadherin Expression and Induces Apoptosis in Renal Tubular Epithelial Cells*

    Science.gov (United States)

    Liu, Wenjing; Li, Xiaoling; Zhao, Yueshui; Meng, Xiao-Ming; Wan, Chao; Yang, Baoxue; Lan, Hui-Yao; Lin, Herbert Y.; Xia, Yin

    2013-01-01

    Dragon is one of the three members of the repulsive guidance molecule (RGM) family, i.e. RGMa, RGMb (Dragon), and RGMc (hemojuvelin). We previously identified the RGM members as bone morphogenetic protein (BMP) co-receptors that enhance BMP signaling. Our previous studies found that Dragon is highly expressed in the tubular epithelial cells of mouse kidneys. However, the roles of Dragon in renal epithelial cells are yet to be defined. We now show that overexpression of Dragon increased cell death induced by hypoxia in association with increased cleaved poly(ADP-ribose) polymerase and cleaved caspase-3 levels in mouse inner medullary collecting duct (IMCD3) cells. Dragon also inhibited E-cadherin expression but did not affect epithelial-to-mesenchymal transition induced by TGF-β in IMCD3 cells. Previous studies suggest that the three RGM members can function as ligands for the receptor neogenin. Interestingly, our present study demonstrates that the Dragon actions on apoptosis and E-cadherin expression in IMCD3 cells were mediated by the neogenin receptor but not through the BMP pathway. Dragon expression in the kidney was up-regulated by unilateral ureteral obstruction in mice. Compared with wild-type mice, heterozygous Dragon knock-out mice exhibited 45–66% reduction in Dragon mRNA expression, decreased epithelial apoptosis, and increased tubular E-cadherin expression and had attenuated tubular injury after unilateral ureteral obstruction. Our results suggest that Dragon may impair tubular epithelial integrity and induce epithelial apoptosis both in vitro and in vivo. PMID:24052264

  10. The fusarium mycotoxin deoxynivalenol can inhibit plant apoptosis-like programmed cell death.

    Directory of Open Access Journals (Sweden)

    Mark Diamond

    Full Text Available The Fusarium genus of fungi is responsible for commercially devastating crop diseases and the contamination of cereals with harmful mycotoxins. Fusarium mycotoxins aid infection, establishment, and spread of the fungus within the host plant. We investigated the effects of the Fusarium mycotoxin deoxynivalenol (DON on the viability of Arabidopsis cells. Although it is known to trigger apoptosis in animal cells, DON treatment at low concentrations surprisingly did not kill these cells. On the contrary, we found that DON inhibited apoptosis-like programmed cell death (PCD in Arabidopsis cells subjected to abiotic stress treatment in a manner independent of mitochondrial cytochrome c release. This suggested that Fusarium may utilise mycotoxins to suppress plant apoptosis-like PCD. To test this, we infected Arabidopsis cells with a wild type and a DON-minus mutant strain of F. graminearum and found that only the DON producing strain could inhibit death induced by heat treatment. These results indicate that mycotoxins may be capable of disarming plant apoptosis-like PCD and thereby suggest a novel way that some fungi can influence plant cell fate.

  11. Cyclooxygenase inhibitors induce apoptosis in oral cavity cancer cells by increased expression of nonsteroidal anti-inflammatory drug-activated gene

    International Nuclear Information System (INIS)

    Kim, Kyung-Su; Yoon, Joo-Heon; Kim, Jin Kook; Baek, Seung Joon; Eling, Thomas E.; Lee, Won Jae; Ryu, Ji-Hwan; Lee, Jeung Gweon; Lee, Joo-Hwan; Yoo, Jong-Bum

    2004-01-01

    We have investigated whether NAG-1 is induced in oral cavity cancer cells by various NSAIDs and if apoptosis induced by NSAIDs can be linked directly with the induction of NAG-1. NAG-1 expression was increased by diclofenac, aceclofenac, indomethacin, ibuprofen, and sulindac sulfide, in the order of NAG-1 induction, but not by acetaminophen, piroxicam or NS-398. Diclofenac was the most effective NAG-1 inducer. Incubation with diclofenac inhibited cell proliferation and induced apoptosis. The expression of NAG-1 was observed in advance of the induction of apoptosis. Conditioned medium from NAG-1-overexpressing Drosophila cells inhibited SCC 1483 cells proliferation and induced apoptosis. In summary, some NSAIDs induce NAG-1 expression in oral cavity cancer cells and the induced NAG-1 protein appears to mediate apoptosis. Therefore, NSAIDs may be considered as a possible chemopreventive agent against oral cavity cancer

  12. Inhibition of PI3K by ZSTK474 suppressed tumor growth not via apoptosis but G0/G1 arrest

    International Nuclear Information System (INIS)

    Dan, Shingo; Yoshimi, Hisashi; Okamura, Mutsumi; Mukai, Yumiko; Yamori, Takao

    2009-01-01

    Phosphoinositide 3-kinase (PI3K) is a potential target in cancer therapy. Inhibition of PI3K is believed to induce apoptosis. We recently developed a novel PI3K inhibitor ZSTK474 with antitumor efficacy. In this study, we have examined the underlying mode of action by which ZSTK474 exerts its antitumor efficacy. In vivo, ZSTK474 effectively inhibited the growth of human cancer xenografts. In parallel, ZSTK474 treatment suppressed the expression of phospho-Akt, suggesting effective PI3K inhibition, and also suppressed the expression of nuclear cyclin D1 and Ki67, both of which are hallmarks of proliferation. However, ZSTK474 treatment did not increase TUNEL-positive apoptotic cells. In vitro, ZSTK474 induced marked G 0 /G 1 arrest, but did not increase the subdiploid cells or activate caspase, both of which are hallmarks of apoptosis. These results clearly indicated that inhibition of PI3K by ZSTK474 did not induce apoptosis but rather induced strong G 0 /G 1 arrest, which might cause its efficacy in tumor cells.

  13. The role of autophagy in THP-1 macrophages resistance to HIV- vpr-induced apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Hua-ying, E-mail: zhouhuaying_2004@126.com; Zheng, Yu-huang; He, Yan; Chen, Zi; He, Bo

    2017-02-01

    Macrophages are resistant to cell death and are one of HIV reservoirs. HIV viral protein Vpr has the potential to promote infection of and survival of macrophages, which could be a highly significant factor in the development and/or maintenance of macrophage viral reservoirs. However, the impact of vpr on macrophages resistance to apoptosis is yet to be comprehended. Autophagy is a cell survival mechanism under stress state. In this study, we investigated whether autophagy is involved in macrophages resistant to vpr-induced apoptosis. Using the THP1 macrophages, we studied the interconnection between macrophages resistance to apoptosis and autophagy. We found that vpr is able to trigger autophagy in transfected THP-1 macrophages confirmed by electron microscopy (EM) and western blot analysis, and inhibition of autophagy with 3MA increased vpr-induced apoptosis. The results indicate that autophagy may be responsible for maintenance of macrophage HIV reservoirs. - Highlights: • HIV Vpr is able to trigger autophagy in transfected THP-1 macrophages. • Autophagy inhibition increases vpr-transfected THP1-macrophages apoptosis. • Autophagy is involved in THP-1 macrophages resistant to vpr-induced apoptosis.

  14. Inhibition of thromboxane synthase induces lung cancer cell death via increasing the nuclear p27

    Energy Technology Data Exchange (ETDEWEB)

    Leung, Kin Chung; Hsin, Michael K.Y.; Chan, Joey S.Y.; Yip, Johnson H.Y.; Li, Mingyue; Leung, Billy C.S. [Department of Surgery, The Chinese University of Hong Kong, Shatin, New Territories (Hong Kong); Mok, Tony S.K. [Department of Clinical Oncology, The Chinese University of Hong Kong, Shatin, New Territories (Hong Kong); Warner, Timothy D. [The William Harvey Research Institute, Queen Mary University of London, London (United Kingdom); Underwood, Malcolm J. [Department of Surgery, The Chinese University of Hong Kong, Shatin, New Territories (Hong Kong); Chen, George G., E-mail: gchen@cuhk.edu.hk [Department of Surgery, The Chinese University of Hong Kong, Shatin, New Territories (Hong Kong)

    2009-10-15

    The role of thromboxane in lung carcinogenesis is not clearly known, though thromboxane B2 (TXB{sub 2}) level is increased and antagonists of thromboxane receptors or TXA2 can induce apoptosis of lung cancer cells. p27, an atypical tumor suppressor, is normally sequestered in the nucleus. The increased nuclear p27 may result in apoptosis of tumor cells. We hypothesize that the inhibition of thromboxane synthase (TXS) induces the death of lung cancer cells and that such inhibition is associated with the nuclear p27 level. Our experiment showed that the inhibition of TXS significantly induced the death or apoptosis in lung cancer cells. The activity of TXS was increased in lung cancer. The nuclear p27 was remarkably reduced in lung cancer tissues. The inhibition of TXS caused the cell death and apoptosis of lung cancer cells, likely via the elevation of the nuclear p27 since the TXS inhibition promoted the nuclear p27 level and the inhibition of p27 by its siRNA recovered the cell death induced by TXS inhibition. Collectively, lung cancer cells produce high levels of TXB{sub 2} but their nuclear p27 is markedly reduced. The inhibition of TXS results in the p27-related induction of cell death in lung cancer cells.

  15. Inhibition of thromboxane synthase induces lung cancer cell death via increasing the nuclear p27

    International Nuclear Information System (INIS)

    Leung, Kin Chung; Hsin, Michael K.Y.; Chan, Joey S.Y.; Yip, Johnson H.Y.; Li, Mingyue; Leung, Billy C.S.; Mok, Tony S.K.; Warner, Timothy D.; Underwood, Malcolm J.; Chen, George G.

    2009-01-01

    The role of thromboxane in lung carcinogenesis is not clearly known, though thromboxane B2 (TXB 2 ) level is increased and antagonists of thromboxane receptors or TXA2 can induce apoptosis of lung cancer cells. p27, an atypical tumor suppressor, is normally sequestered in the nucleus. The increased nuclear p27 may result in apoptosis of tumor cells. We hypothesize that the inhibition of thromboxane synthase (TXS) induces the death of lung cancer cells and that such inhibition is associated with the nuclear p27 level. Our experiment showed that the inhibition of TXS significantly induced the death or apoptosis in lung cancer cells. The activity of TXS was increased in lung cancer. The nuclear p27 was remarkably reduced in lung cancer tissues. The inhibition of TXS caused the cell death and apoptosis of lung cancer cells, likely via the elevation of the nuclear p27 since the TXS inhibition promoted the nuclear p27 level and the inhibition of p27 by its siRNA recovered the cell death induced by TXS inhibition. Collectively, lung cancer cells produce high levels of TXB 2 but their nuclear p27 is markedly reduced. The inhibition of TXS results in the p27-related induction of cell death in lung cancer cells.

  16. Ionizing radiation induces apoptosis in hematopoietic stem and progenitor cells

    International Nuclear Information System (INIS)

    Meng, A.; Zhou, D.; Geiger, H.; Zant, G.V.

    2003-01-01

    The aims of this study was to determine if ionizing radiation (IR) induces apoptosis in hematopoietic stem (HSC) and progenitor cells. Lin-cells were isolated from mouse bone marrow (BM) and pretreated with vehicle or 100 μM z-VAD 1 h prior to exposure to 4 Gy IR. The apoptotic and/or necrotic responses of these cells to IR were analyzed by measuring the annexin V and/or 7-AAD staining in HSC and progenitor populations using flow cytometry, and hematopoietic function of these cells was determined by CAFC assay. Exposure of Lin-cells to IR selectively decreased the numbers of HSC and progenitors in association with an increase in apoptosis in a time-dependent manner. Pretreatment of Lin- cells with z-VAD significantly inhibited IR-induced apoptosis and the decrease in the numbers of HSC and progenitors. However, IR alone or in combination with z-VAD did not lead to a significant increase in necrotic cell death in either HSC or progenitors. In addition, pretreatment of BM cells with z-VAD significantly attenuated IR-induced reduction in the frequencies of day-7, -28 and -35 CAFC. Exposure of HSC and progenitors to IR induces apoptosis. The induction of HSC and progenitor apoptosis contributes to IR-induced suppression of their hematopoietic function

  17. Functional role of CCCTC binding factor (CTCF) in stress-induced apoptosis

    International Nuclear Information System (INIS)

    Li Tie; Lu Luo

    2007-01-01

    CTCF, a nuclear transcriptional factor, is a multifunctional protein and involves regulation of growth factor- and cytokine-induced cell proliferation/differentiation. In the present study, we investigated the role of CTCF in protecting stress-induced apoptosis in various human cell types. We found that UV irradiation and hyper-osmotic stress induced human corneal epithelial (HCE) and hematopoietic myeloid cell apoptosis detected by significantly increased caspase 3 activity and decreased cell viability. The stress-induced apoptotic response in these cells requires down-regulation of CTCF at both mRNA and protein levels, suggesting that CTCF may play an important role in downstream events of stress-induced signaling pathways. Inhibition of NFκB activity prevented stress-induced down-regulation of CTCF and increased cell viability against stress-induced apoptosis. The anti-apoptotic effect of CTCF was further studied by manipulating CTCF activities in HCE and hematopoietic cells. Transient transfection of cDNAs encoding full-length human CTCF markedly suppressed stress-induced apoptosis in these cells. In contrast, knocking down of CTCF mRNA using siRNA specific to CTCF significantly promoted stress-induced apoptosis. Thus, our results reveal that CTCF is a down stream target of stress-induced signaling cascades and it plays a significant anti-apoptotic role in regulation of stress-induced cellular responses in HCE and hematopoietic myeloid cells

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

    Science.gov (United States)

    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

  19. Abrogation of Early Apoptosis Does Not Alter Late Inhibition of Hippocampal Neurogenesis After Irradiation

    International Nuclear Information System (INIS)

    Li Yuqing; Aubert, Isabelle; Wong, C. Shun

    2010-01-01

    Purpose: Irradiation of the adult brain results in acute apoptosis of neural progenitors and vascular endothelial cells, as well as late dysfunction of neural progenitors and inhibition of neurogenesis. We sought to determine whether the early apoptotic response has a causative role in late inhibition of neurogenesis after cranial irradiation. Methods and Materials: Using a genetic approach with p53 and smpd1 transgenic mice and a pharmacologic approach with basic fibroblast growth factor (bFGF) to abrogate the early apoptotic response, we evaluated the late inhibition of neurogenesis in the hippocampal dentate gyrus after cranial irradiation. Results: In dentate gyrus, subgranular neural progenitors underwent p53-dependent apoptosis within 24 h after irradiation. Despite a near abrogation of neural progenitor apoptosis in p53-/- mice, the reduction in newborn neurons in dentate gyrus at 9 weeks after irradiation in p53-/- mice was not different from that observed in wildtype controls. Endothelial cell apoptosis after radiation is mediated by membrane damage initiated by activation of acid sphingomyelinase (ASMase). Deletion of the smpd1 gene (which encodes ASMase) attenuated the apoptotic response of endothelial cells. At 9 weeks after irradiation, the inhibition of hippocampal neurogenesis was not rescued by ASMase deficiency. Intravenous administration of bFGF protected both endothelial cells and neural progenitors against radiation-induced apoptosis. There was no protection against inhibition of neurogenesis at 9 weeks after irradiation in bFGF-treated mice. Conclusion: Early apoptotic death of neural progenitors, endothelial cells, or both does not have a causative association with late inhibition of neurogenesis after irradiation.

  20. 5-Geranyloxy-7-methoxycoumarin inhibits colon cancer (SW480) cells growth by inducing apoptosis.

    Science.gov (United States)

    Patil, Jaiprakash R; Jayaprakasha, Guddadarangavvanahally K; Kim, Jinhee; Murthy, Kotamballi N Chidambara; Chetti, Mahadev B; Nam, Sang-Yong; Patil, Bhimanagouda S

    2013-03-01

    For the first time, three coumarins were isolated from the hexane extract of limes (Citrus aurantifolia) and purified by flash chromatography. The structures were identified by NMR (1D, 2D) and mass spectral analyses as 5-geranyloxy-7-methoxycoumarin, limettin, and isopimpinellin. These compounds inhibited human colon cancer (SW-480) cell proliferation, with 5-geranyloxy-7-methoxycoumarin showing the highest inhibition activity (67 %) at 25 µM. Suppression of SW480 cell proliferation by 5-geranyloxy-7-methoxycoumarin was associated with induction of apoptosis, as evidenced by annexin V staining and DNA fragmentation. In addition, 5-geranyloxy-7-methoxycoumarin arrested cells at the G0/G1 phase, and induction of apoptosis was demonstrated through the activation of tumour suppressor gene p53, caspase8/3, regulation of Bcl2, and inhibition of p38 MAPK phosphorylation. These findings suggest that 5-geranyloxy-7-methoxycoumarin has potential as a cancer preventive agent. Georg Thieme Verlag KG Stuttgart · New York.

  1. Palmitate induces VSMC apoptosis via toll like receptor (TLR)4/ROS/p53 pathway.

    Science.gov (United States)

    Zhang, Yuanjun; Xia, Guanghao; Zhang, Yaqiong; Liu, Juxiang; Liu, Xiaowei; Li, Weihua; Lv, Yaya; Wei, Suhong; Liu, Jing; Quan, Jinxing

    2017-08-01

    Toll-like receptor 4 (TLR4) has been implicated in vascular inflammation, as well as in the pathogenesis of atherosclerosis and diabetes. Vascular smooth muscle cell (VSMC) apoptosis has been shown to induce plaque vulnerability in atherosclerosis. Previous studies reported that palmitate induced apoptosis in VSMCs; however, the role of TLR4 in palmitate-induced apoptosis in VSMCs has not yet been defined. In this study, we investigated whether or not palmitate-induced apoptosis depended on the activation of the TLR4 pathway. VSMCs were treated with or without palmitate, CRISPR/Cas9z-mediated genome editing methods were used to deplete TLR4 expression, while NADPH oxidase inhibitors were used to inhibit reactive oxygen species (ROS) generation. Cell apoptosis was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, ROS was measured using the 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) method, the mRNA and protein expression levels of caspase 3, caspase 9, BCL-2 and p53 were studied by real-time polymerase chain reaction (RT-PCR) and ELISA. Palmitate significantly promotes VSMC apoptosis, ROS generation, and expression of caspase 3, caspase 9 and p53; while NADPH oxidase inhibitor pretreatment markedly attenuated these effects. Moreover, knockdown of TLR4 significantly blocked palmitate-induced ROS generation and VSMC apoptosis accompanied by inhibition of caspase 3, caspase 9, p53 expression and restoration of BCL-2 expression. Our results suggest that palmitate-induced apoptosis depends on the activation of the TLR4/ROS/p53 signaling pathway, and that TLR4 may be a potential therapeutic target for the prevention and treatment of atherosclerosis. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Poxviruses Utilize Multiple Strategies to Inhibit Apoptosis

    Science.gov (United States)

    Nichols, Daniel Brian; De Martini, William; Cottrell, Jessica

    2017-01-01

    Cells have multiple means to induce apoptosis in response to viral infection. Poxviruses must prevent activation of cellular apoptosis to ensure successful replication. These viruses devote a substantial portion of their genome to immune evasion. Many of these immune evasion products expressed during infection antagonize cellular apoptotic pathways. Poxvirus products target multiple points in both the extrinsic and intrinsic apoptotic pathways, thereby mitigating apoptosis during infection. Interestingly, recent evidence indicates that poxviruses also hijack cellular means of eliminating apoptotic bodies as a means to spread cell to cell through a process called apoptotic mimicry. Poxviruses are the causative agent of many human and veterinary diseases. Further, there is substantial interest in developing these viruses as vectors for a variety of uses including vaccine delivery and as oncolytic viruses to treat certain human cancers. Therefore, an understanding of the molecular mechanisms through which poxviruses regulate the cellular apoptotic pathways remains a top research priority. In this review, we consider anti-apoptotic strategies of poxviruses focusing on three relevant poxvirus genera: Orthopoxvirus, Molluscipoxvirus, and Leporipoxvirus. All three genera express multiple products to inhibit both extrinsic and intrinsic apoptotic pathways with many of these products required for virulence. PMID:28786952

  3. Licoricidin inhibits the growth of SW480 human colorectal adenocarcinoma cells in vitro and in vivo by inducing cycle arrest, apoptosis and autophagy

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Shuai [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191 (China); Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, School of Pharmacy, Xuzhou Medical University, 209 Tongshan Road, Xuzhou 221004 (China); Tang, Shunan; Li, Kai; Li, Ziwei; Liang, Wenfei; Qiao, Xue; Wang, Qi [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191 (China); Yu, Siwang, E-mail: swang_yu@bjmu.edu.cn [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191 (China); Ye, Min, E-mail: yemin@bjmu.edu.cn [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191 (China)

    2017-07-01

    Licorice (Glycyrrhiza uralensis Fisch.) possesses significant anti-cancer activities, but the active ingredients and underlying mechanisms have not been revealed. By screening the cytotoxic activities of 122 licorice compounds against SW480 human colorectal adenocarcinoma cells, we found that licoricidin (LCD) inhibited SW480 cell viability with an IC{sub 50} value of 7.2 μM. Further studies indicated that LCD significantly induced G1/S cell cycle arrest and apoptosis in SW480 cells, accompanied by inhibition of cyclins/CDK1 expression and activation of caspase-dependent pro-apoptotic signaling. Meanwhile, LCD promoted autophagy in SW480 cells, and activated AMPK signaling and inhibited Akt/mTOR pathway. Overexpression of a dominant-negative AMPKα2 abolished LCD-induced inhibition of Akt/mTOR, autophagic and pro-apoptotic signaling pathways, and significantly reversed loss of cell viability, suggesting activation of AMPK is essential for the anti-cancer activity of LCD. In vivo anti-tumor experiments indicated that LCD (20 mg/kg, i.p.) significantly inhibited the growth of SW480 xenografts in nude mice with an inhibitory rate of 43.5%. In addition, we obtained the glycosylated product LCDG by microbial transformation, and found that glycosylation slightly enhanced the in vivo anti-cancer activities of LCD. This study indicates that LCD could inhibit SW480 cells by inducing cycle arrest, apoptosis and autophagy, and is a potential chemopreventive or chemotherapeutic agent against colorectal cancer. - Highlights: • Molecular mechanisms for cytotoxic activity of licoricidin (LCD) were investigated. • LCD promoted autophagy of SW480 cells through AMPK and Akt/mTOR signaling pathways. • Both LCD and its glucoside showed in vivo anti-colorectal cancer activities.

  4. INHIBITION OF SPONTANEOUS APOPTOSIS IN HUMAN BREAST CANCER

    Institute of Scientific and Technical Information of China (English)

    邵志敏; 江明; 吴炅; 余黎民; 韩企夏; 张延璆; 沈镇宙

    1996-01-01

    Breast tumorigenesis proceeds through an accumulation of specific genetic alteration. Breast malignant transformation is dependent on not only the rate of cell production but also on apoptcsis,a genetically prograined process of autonomous ceil death. We investigated whether breast tumorigenesis involved an altered susceptibility to apoptosis and proliferation by examining normal breast epithelium and breast cancer sampies. We found there is a great inhibition of spontaneous apoptosis in breast cancer ceils compared with normal breast epithelium. The inhibition of apoptosis in breast cancer may contribute to neoplastic transformation.

  5. The mechanism of kaempferol induced apoptosis and inhibited proliferation in human cervical cancer SiHa cell: From macro to nano.

    Science.gov (United States)

    Tu, Lv-Ying; Bai, Hai-Hua; Cai, Ji-Ye; Deng, Sui-Ping

    2016-11-01

    Kaempferol has been identified as a potential cancer therapeutic agent by an increasing amount of evidences. However, the changes in the topography of cell membrane induced by kaempferol at subcellular- or nanometer-level were still unclear. In this work, the topographical changes of cytomembrane in human cervical cancer cell (SiHa) induced by kaempferol, as well as the role of kaempferol in apoptosis induction and its possible mechanisms, were investigated. At the macro level, MTT assays showed that kaempferol inhibited the proliferation of SiHa cells in a time- and dose-dependent manner. Flow cytometry analysis demonstrated that kaempferol could induce SiHa cell apoptosis, mitochondrial membrane potential disruption, and intracellular free calcium elevation. At the micro level, fluorescence imaging by laser scanning confocal microscopy (LSCM) indicated that kaempferol could also destroy the networks of microtubules. Using high resolution atomic force microscopy (AFM), we determined the precise changes of cellular membrane induced by kaempferol at subcellular or nanometer level. The spindle-shaped SiHa cells shrank after kaempferol treatment, with significantly increased cell surface roughness. These data showed structural characterizations of cellular topography in kaempferol-induced SiHa cell apoptosis and might provide novel integrated information from macro to nano level to assess the impact of kaempferol on cancer cells, which might be important for the understanding of the anti-cancer mechanisms of drugs. SCANNING 38:644-653, 2016. © 2016 Wiley Periodicals, Inc. © Wiley Periodicals, Inc.

  6. Mitofusin 2 Promotes Apoptosis of CD4+ T Cells by Inhibiting Autophagy in Sepsis

    Directory of Open Access Journals (Sweden)

    Lan Ying

    2017-01-01

    Full Text Available Apoptosis of CD4+ T cells is a primary pathophysiological mechanism of immune dysfunction in the pathogenesis of sepsis. Mitofusin 2 (Mfn2, an integral mitochondrial outer membrane protein, has been confirmed to be associated with cellular metabolism, proliferation, and apoptosis. The function of Mfn2 in CD4+ T cell apoptosis in sepsis is poorly understood. Here, we discovered increased in vivo Mfn2 expression, autophagy deficiency, and elevated cell apoptosis in murine splenic CD4+ T cells after cecal ligation and puncture (CLP. We also observed almost identical results in splenic CD4+ T cells upon lipopolysaccharide (LPS stimulation in vitro. Furthermore, overexpression of Mfn2 resulted in impaired autophagy and increased apoptosis in Jurkat cells. Pharmacological inhibition of autophagy with 3-methyladenine enhanced Mfn2 overexpression-induced cell apoptosis. In addition, overexpression of Mfn2 downregulated phorbol myristate acetate (PMA/ionomycin-, rapamycin- and starvation-induced autophagy in Jurkat T cells. Taken together, these data indicate a critical role of Mfn2 in CD4+ T cell apoptosis in sepsis and the underlying mechanism of autophagy deficiency.

  7. Dopamine Attenuates Ketamine-Induced Neuronal Apoptosis in the Developing Rat Retina Independent of Early Synchronized Spontaneous Network Activity.

    Science.gov (United States)

    Dong, Jing; Gao, Lingqi; Han, Junde; Zhang, Junjie; Zheng, Jijian

    2017-07-01

    Deprivation of spontaneous rhythmic electrical activity in early development by anesthesia administration, among other interventions, induces neuronal apoptosis. However, it is unclear whether enhancement of neuronal electrical activity attenuates neuronal apoptosis in either normal development or after anesthesia exposure. The present study investigated the effects of dopamine, an enhancer of spontaneous rhythmic electrical activity, on ketamine-induced neuronal apoptosis in the developing rat retina. TUNEL and immunohistochemical assays indicated that ketamine time- and dose-dependently aggravated physiological and ketamine-induced apoptosis and inhibited early-synchronized spontaneous network activity. Dopamine administration reversed ketamine-induced neuronal apoptosis, but did not reverse the inhibitory effects of ketamine on early synchronized spontaneous network activity despite enhancing it in controls. Blockade of D1, D2, and A2A receptors and inhibition of cAMP/PKA signaling partially antagonized the protective effect of dopamine against ketamine-induced apoptosis. Together, these data indicate that dopamine attenuates ketamine-induced neuronal apoptosis in the developing rat retina by activating the D1, D2, and A2A receptors, and upregulating cAMP/PKA signaling, rather than through modulation of early synchronized spontaneous network activity.

  8. Lentiviral-mediated RNAi targeting caspase-3 inhibits apoptosis induced by serum deprivation in rat endplate chondrocytes in vitro

    International Nuclear Information System (INIS)

    Ding, L.; Wu, J.P.; Xu, G.; Zhu, B.; Zeng, Q.M.; Li, D.F.; Lu, W.

    2014-01-01

    Current studies find that degenerated cartilage endplates (CEP) of vertebrae, with fewer diffusion areas, decrease nutrient supply and accelerate intervertebral disc degeneration. Many more apoptotic cells have been identified in degenerated than in normal endplates, and may be responsible for the degenerated grade. Previous findings suggest that inhibition of apoptosis is one possible approach to improve disc regeneration. It is postulated that inhibition of CEP cell apoptosis may be responsible for the regeneration of endplates. Caspase-3, involved in the execution phase of apoptosis, is a candidate for regulating the apoptotic process. In the present study, CEP cells were incubated in 1% fetal bovine serum. Activated caspases were detected to identify the apoptotic pathway, and apoptosis was quantified by flow cytometry. Lentiviral caspase-3 short hairpin RNA (shRNA) was employed to study its protective effects against serum deprivation. Silencing of caspase-3 expression was quantified by reverse transcription-polymerase chain reaction and Western blots, and inhibition of apoptosis was quantified by flow cytometry. Serum deprivation increased apoptosis of rat CEP cells through activation of a caspase cascade. Lentiviral caspase-3 shRNA was successfully transduced into CEP cells, and specifically silenced endogenous caspase-3 expression. Surviving cells were protected by the downregulation of caspase-3 expression and activation. Thus, lentiviral caspase-3 shRNA-mediated RNAi successfully silenced endogenous caspase-3 expression, preventing inappropriate or premature apoptosis

  9. Lentiviral-mediated RNAi targeting caspase-3 inhibits apoptosis induced by serum deprivation in rat endplate chondrocytes in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Ding, L.; Wu, J.P. [Fudan University, Jinshan Hospital, Department of Orthopaedics, Shanghai, China, Department of Orthopaedics, Jinshan Hospital, Fudan University, Shanghai (China); Xu, G. [Fudan University, Jinshan Hospital, Center Laboratory, Shanghai, China, Center Laboratory, Jinshan Hospital, Fudan University, Shanghai (China); Zhu, B.; Zeng, Q.M.; Li, D.F.; Lu, W. [Fudan University, Jinshan Hospital, Department of Orthopaedics, Shanghai, China, Department of Orthopaedics, Jinshan Hospital, Fudan University, Shanghai (China)

    2014-05-09

    Current studies find that degenerated cartilage endplates (CEP) of vertebrae, with fewer diffusion areas, decrease nutrient supply and accelerate intervertebral disc degeneration. Many more apoptotic cells have been identified in degenerated than in normal endplates, and may be responsible for the degenerated grade. Previous findings suggest that inhibition of apoptosis is one possible approach to improve disc regeneration. It is postulated that inhibition of CEP cell apoptosis may be responsible for the regeneration of endplates. Caspase-3, involved in the execution phase of apoptosis, is a candidate for regulating the apoptotic process. In the present study, CEP cells were incubated in 1% fetal bovine serum. Activated caspases were detected to identify the apoptotic pathway, and apoptosis was quantified by flow cytometry. Lentiviral caspase-3 short hairpin RNA (shRNA) was employed to study its protective effects against serum deprivation. Silencing of caspase-3 expression was quantified by reverse transcription-polymerase chain reaction and Western blots, and inhibition of apoptosis was quantified by flow cytometry. Serum deprivation increased apoptosis of rat CEP cells through activation of a caspase cascade. Lentiviral caspase-3 shRNA was successfully transduced into CEP cells, and specifically silenced endogenous caspase-3 expression. Surviving cells were protected by the downregulation of caspase-3 expression and activation. Thus, lentiviral caspase-3 shRNA-mediated RNAi successfully silenced endogenous caspase-3 expression, preventing inappropriate or premature apoptosis.

  10. Lentiviral-mediated RNAi targeting caspase-3 inhibits apoptosis induced by serum deprivation in rat endplate chondrocytes in vitro

    Directory of Open Access Journals (Sweden)

    L. Ding

    2014-06-01

    Full Text Available Current studies find that degenerated cartilage endplates (CEP of vertebrae, with fewer diffusion areas, decrease nutrient supply and accelerate intervertebral disc degeneration. Many more apoptotic cells have been identified in degenerated than in normal endplates, and may be responsible for the degenerated grade. Previous findings suggest that inhibition of apoptosis is one possible approach to improve disc regeneration. It is postulated that inhibition of CEP cell apoptosis may be responsible for the regeneration of endplates. Caspase-3, involved in the execution phase of apoptosis, is a candidate for regulating the apoptotic process. In the present study, CEP cells were incubated in 1% fetal bovine serum. Activated caspases were detected to identify the apoptotic pathway, and apoptosis was quantified by flow cytometry. Lentiviral caspase-3 short hairpin RNA (shRNA was employed to study its protective effects against serum deprivation. Silencing of caspase-3 expression was quantified by reverse transcription-polymerase chain reaction and Western blots, and inhibition of apoptosis was quantified by flow cytometry. Serum deprivation increased apoptosis of rat CEP cells through activation of a caspase cascade. Lentiviral caspase-3 shRNA was successfully transduced into CEP cells, and specifically silenced endogenous caspase-3 expression. Surviving cells were protected by the downregulation of caspase-3 expression and activation. Thus, lentiviral caspase-3 shRNA-mediated RNAi successfully silenced endogenous caspase-3 expression, preventing inappropriate or premature apoptosis.

  11. Novel TRAIL sensitizer Taraxacum officinale F.H. Wigg enhances TRAIL-induced apoptosis in Huh7 cells.

    Science.gov (United States)

    Yoon, Ji-Yong; Cho, Hyun-Soo; Lee, Jeong-Ju; Lee, Hyo-Jung; Jun, Soo Young; Lee, Jae-Hye; Song, Hyuk-Hwan; Choi, SangHo; Saloura, Vassiliki; Park, Choon Gil; Kim, Cheol-Hee; Kim, Nam-Soon

    2016-04-01

    TRAIL (TNF-related apoptosis inducing ligand) is a promising anti-cancer drug target that selectively induces apoptosis in cancer cells. However, many cancer cells are resistant to TRAIL-induced apoptosis. Therefore, reversing TRAIL resistance is an important step for the development of effective TRAIL-based anti-cancer therapies. We previously reported that knockdown of the TOR signaling pathway regulator-like (TIPRL) protein caused TRAIL-induced apoptosis by activation of the MKK7-c-Jun N-terminal Kinase (JNK) pathway through disruption of the MKK7-TIPRL interaction. Here, we identified Taraxacum officinale F.H. Wigg (TO) as a novel TRAIL sensitizer from a set of 500 natural products using an ELISA system and validated its activity by GST pull-down analysis. Furthermore, combination treatment of Huh7 cells with TRAIL and TO resulted in TRAIL-induced apoptosis mediated through inhibition of the MKK7-TIPRL interaction and subsequent activation of MKK7-JNK phosphorylation. Interestingly, HPLC analysis identified chicoric acid as a major component of the TO extract, and combination treatment with chicoric acid and TRAIL induced TRAIL-induced cell apoptosis via JNK activation due to inhibition of the MKK7-TIPRL interaction. Our results suggest that TO plays an important role in TRAIL-induced apoptosis, and further functional studies are warranted to confirm the importance of TO as a novel TRAIL sensitizer for cancer therapy. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  12. Apoptosis induced by chlormethine and ionizing radiations in normal and tumoral lymphocytes: role of caspase-3

    International Nuclear Information System (INIS)

    Holl, V.P.

    2000-01-01

    Apoptosis can be induced by various stimuli like ionizing radiations or alkylating agents. Recent works have shown that apoptosis due to ionizing radiations can be initiated by DNA and cell membrane alterations, via radical species generation, implying the in fine activation of effector caspases, and in particular caspase-3. The main goal of this work is to clarify the role of caspase-3 in the radio-induced apoptosis mechanisms and to study the effects of apoptosis inhibition on the behaviour of the damaged cells. The effects of activation and caspase-3 activity inhibition on the progress of spontaneous, radio-induced or chlormethine-induced apoptosis have been evaluated for normal and tumoral lymphocytes. A chemical molecule, the ebselen, which can mime the action of the endogenous glutathione peroxidase, and a tetra-peptide inhibitor, AC-DEVD-CHO, selective of effector caspases, have been selected. The results indicate an inhibition by ebselen of all morphological and biochemical characteristics of chlormethine-induced apoptosis and a restoring of the cells viability. This seleno-organic compound also reduces the drop of the intra-cellular glutathione level and the loss of the trans-membrane potential (M) of the mitochondrion in the MOLT-4 tumoral cells treated with chlormethine. In parallel, the AC-DEVD-CHO effect on apoptosis induction has been tested. This inhibitor stops some chlormethine-induced criteria of apoptosis without affecting the final loss of the mitochondrial M and the cells proliferation. AC-DEVD-CHO has been also incubated just before the irradiation of the culture cells. The inhibition of the specific DEVD caspases prevents the inter-nucleosomal fragmentation of DNA and partially delays the externalization of phosphatidylserine without changing the viability of the irradiated cells. Moreover, the analysis of the AC-DEVD-CHO pre-treated irradiated cells floating on the surface shows a strong mitochondrial lactate dehydrogenase activity, which

  13. PRAF3 induces apoptosis and inhibits migration and invasion in human esophageal squamous cell carcinoma

    International Nuclear Information System (INIS)

    Shi, Guo-Zhen; Yuan, Yang; Jiang, Guo-Jun; Ge, Zhi-Jun; Zhou, Jian; Gong, De-Jun; Tao, Jing; Tan, Yong-Fei; Huang, Sheng-Dong

    2012-01-01

    Prenylated Rab acceptor 1 domain family member 3 (PRAF3) is involved in the regulation of many cellular processes including apoptosis, migration and invasion. This study was conducted to investigate the effect of PRAF3 on apoptosis, migration and invasion in human esophageal squamous cell carcinoma (ESCC). The expression of PRAF3 mRNA and protein in primary ESCC and the matched normal tissues (57cases) was determined by quantitative RT-PCR and Western blot. Immunohistochemical analysis of PRAF3 expression was carried out in paraffin-embedded sections of ESCC and correlated with clinical features. The role of PRAF3 in apoptosis, migration and invasion was studied in ESCC cell lines of Eca109 and TE-1 through the adenovirus mediated PRAF3 gene transfer. The effect of PRAF3 on apoptosis was analyzed by annexin V-FITC assay. The regulation of PRAF3 on migration was determined by transwell and wounding healing assay, while the cellular invasion was analyzed by matrigel-coated transwell assay. We found that the expression of PRAF3 was significantly down-regulated in ESCC tissue compared with the matched normal tissue and was correlated with the clinical features of pathological grade, tumor stage and lymph node metastasis. Moreover, overexpression of PRAF3 induced cell apoptosis through both caspase-8 and caspase-9 dependent pathways, and inhibited cell migration and invasion by suppressing the activity of both MMP-2 and MMP-9 in human ESCC cell lines. Our data suggest that PRAF3 plays an important role in the regulation of tumor progression and metastasis and serves as a tumor suppressor in human ESCC. We propose that PRAF3 might be used as a potential therapeutic agent for human ESCC

  14. [Gene Expression Profile of Apoptosis in Leukemia Cells Induced by Hsp90 Selective inhibitor 17-AAG].

    Science.gov (United States)

    Wang, Na-Na; Li, Zhi-Heng; Tao, Yan-Fang; Xu, Li-Xiao; Pan, Jian; Hu, Shao-Yan

    2016-06-01

    To investigate the apoptotic effects of Hsp90 selective inhibitor 17-AAG on human leukemia HL-60 and NB4 cells and analyse its possible mechanism. CCK-8 assay was used to quantify the growth inhibition of cells after exposure to 17-AAG for 24 hours. Flow cytometrve with annexin V/propidium iodide staining was used to detect apoptosis of leukemia cells. Then Western blot was used to detect the activation of apoptosis related protein caspase-3 and PARP level. Gene expression profile of NB4 cells treated with 17-AAG was analyzed with real-time PCR arrays. The inhibition of leukemia cell proliferation displayed a dose-dependent manner. Annexin V assay, cell cycle analysis and activation of PARP demonstrate that 17-AAG induced apoptosis leukemia cells. Real-time PCR array analysis showed that expression of 56 genes significantly up-regulated and expression of 23 genes were significantly down-regulated after 17-AAG treatment. The 17-AAG can inhibit the proliferation and induce the apoptosis of leukemia cells. After leukemia cells are treated with 17-AAG, the significant changes of apoptosis-related genes occured, and the cell apoptosis occurs via activating apoptosis related signaling pathway.

  15. Azadirachtin-induced apoptosis involves lysosomal membrane permeabilization and cathepsin L release in Spodoptera frugiperda Sf9 cells.

    Science.gov (United States)

    Wang, Zheng; Cheng, Xingan; Meng, Qianqian; Wang, Peidan; Shu, Benshui; Hu, Qiongbo; Hu, Meiying; Zhong, Guohua

    2015-07-01

    Azadirachtin as a kind of botanical insecticide has been widely used in pest control. We previously reported that azadirachtin could induce apoptosis of Spodoptera litura cultured cell line Sl-1, which involves in the up-regulation of P53 protein. However, the detailed mechanism of azadirachtin-induced apoptosis is not clearly understood in insect cultured cells. The aim of the present study was to address the involvement of lysosome and lysosomal protease in azadirachtin-induced apoptosis in Sf9 cells. The result confirmed that azadirachtin indeed inhibited proliferation and induced apoptosis. The lysosomes were divided into different types as time-dependent manner, which suggested that changes of lysosomes were necessarily physiological processes in azadirachtin-induced apoptosis in Sf9 cells. Interestingly, we noticed that azadirachtin could trigger lysosomal membrane permeabilization and cathepsin L releasing to cytosol. Z-FF-FMK (a cathepsin L inhibitor), but not CA-074me (a cathepsin B inhibitor), could effectively hinder the apoptosis induced by azadirachtin in Sf9 cells. Meanwhile, the activity of caspase-3 could also be inactivated by the inhibition of cathepsin L enzymatic activity induced by Z-FF-FMK. Taken together, our findings suggest that azadirachtin could induce apoptosis in Sf9 cells in a lysosomal pathway, and cathepsin L plays a pro-apoptosis role in this process through releasing to cytosol and activating caspase-3. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Glycoprotein 5 of porcine reproductive and respiratory syndrome virus strain SD16 inhibits viral replication and causes G2/M cell cycle arrest, but does not induce cellular apoptosis in Marc-145 cells

    International Nuclear Information System (INIS)

    Mu, Yang; Li, Liangliang; Zhang, Beibei; Huang, Baicheng; Gao, Jiming

    2015-01-01

    Cell apoptosis is common after infection with porcine reproductive and respiratory syndrome virus (PRRSV). PRRSV GP5 has been reported to induce cell apoptosis. To further understand the role of GP5 in PRRSV induced cell apoptosis, we established Marc-145 cell lines stably expressing full-length GP5, GP5 Δ84-96 (aa 84-96 deletion), and GP5 Δ97-119 (aa 97-119 deletion). Cell proliferation, cell cycle progression, cell apoptosis and virus replication in these cell lines were evaluated. Neither truncated nor full-length GP5 induced cell apoptosis in Marc-145 cells. However, GP5 Δ97-119 , but not full-length or GP5 Δ84-96 , induced a cell cycle arrest at the G2/M phase resulting in a reduction in the growth of Marc-145 cells. Additionally, GP5 Δ84-96 inhibited the replication of PRRSV in Marc-145 cells through induction of IFN-β. These findings suggest that PRRSV GP5 is not responsible for inducing cell apoptosis in Marc-145 cells under these experimental conditions; however it has other important roles in virus/host cell biology. - Highlights: • Marc-145 cell lines stable expression PRRSV GP5 or truncated GP5 were constructed. • GP5 Δ97-119 expression in Marc-145 cell induced cell cycle arrest at G2/M phase. • Expression of GP5 and truncated GP5 could not induce Marc-145 cells apoptosis. • PRRSV replication in Marc-145-GP5 Δ84-96 was significantly inhibited

  17. Activation of P2X7-mediated apoptosis Inhibits DMBA/TPA-induced formation of skin papillomas and cancer in mice

    International Nuclear Information System (INIS)

    Fu, Wen; Gorodeski, George I; McCormick, Tom; Qi, Xiaoping; Luo, Liping; Zhou, Lingyin; Li, Xin; Wang, Bing-Cheng; Gibbons, Heidi E; Abdul-Karim, Fadi W

    2009-01-01

    The study tested the hypothesis that apoptosis can prevent and control growth of neoplastic cells. Previous studies in-vitro have shown that the pro-apoptotic P2X 7 receptor regulates growth of epithelial cells. The specific objective of the present study was to understand to what degree the P2X 7 system controls development and growth of skin cancer in vivo, and what cellular and molecular mechanisms are involved in the P2X 7 action. Skin neoplasias in mice (papillomas, followed by squamous spindle-cell carcinomas) were induced by local application of DMBA/TPA. Experiments in-vitro utilized cultured epidermal keratinocytes generated from wild-type or from P2X 7 -null mice. Assays involved protein immunostaining and Western blots; mRNA real-time qPCR; and apoptosis (evaluated in situ by TUNEL and quantified in cultured keratinocytes as solubilized DNA or by ELISA). Changes in cytosolic calcium or in ethidium bromide influx (P2X 7 pore formation) were determined by confocal laser microscopy. (a) Co-application on the skin of the P2X 7 specific agonist BzATP inhibited formation of DMBA/TPA-induced skin papillomas and carcinomas. At the completion of study (week 28) the proportion of living animals with cancers in the DMBA/TPA group was 100% compared to 43% in the DMBA/TPA+BzATP group. (b) In the normal skin BzATP affected mainly P2X 7 -receptor – expressing proliferating keratinocytes, where it augmented apoptosis without evoking inflammatory changes. (c) In BzATP-treated mice the degree of apoptosis was lesser in cancer than in normal or papilloma keratinocytes. (d) Levels of P2X 7 receptor, protein and mRNA were 4–5 fold lower in cancer tissues than in normal mouse tissues. (e) In cultured mouse keratinocytes BzATP induced apoptosis, formation of pores in the plasma membrane, and facilitated prolonged calcium influx. (f) The BzATP-induced apoptosis, pore-formation and augmented calcium influx had similar dose-dependence for BzATP. (g) Pore formation and the

  18. H2O2 INDUCES APOPTOSIS OF RABBIT CHONDROCYTES VIA BOTH THE EXTRINSIC AND THE CASPASE-INDEPENDENT INTRINSIC PATHWAYS

    Directory of Open Access Journals (Sweden)

    CAIPING ZHUANG

    2013-07-01

    Full Text Available Osteoarthritis (OA, one of the most common joint diseases with unknown etiology, is characterized by the progressive destruction of articular cartilage and the apoptosis of chondrocytes. The purpose of this study is to elucidate the molecular mechanisms of H2O2-mediated rabbit chondrocytes apoptosis. CCK-8 assay showed that H2O2 treatment induced a remarkable reduction of cell viability, which was further verified by the remarkable phosphatidylserine externalization after H2O2 treatment for 1 h, the typical characteristics of apoptosis. H2O2 treatment induced a significant dysfunction of mitochondrial membrane potential (ΔΨm, but did not induce casapse-9 activation, indicating that H2O2 treatment induced caspase-independent intrinsic apoptosis that was further verified by the fact that silencing of AIF but not inhibiting caspase-9 potently prevented H2O2-induced apoptosis. H2O2 treatment induced a significant increase of caspase-8 and -3 activation, and inhibition of caspase-8 or -3 significantly prevented H2O2-induced apoptosis, suggesting that the extrinsic pathway played an important role. Collectively, our findings demonstrate that H2O2 induces apoptosis via both the casapse-8-mediated extrinsic and the caspase-independent intrinsic apoptosis pathways in rabbit chondrocytes.

  19. CD147 promotes IKK/IκB/NF-κB pathway to resist TNF-induced apoptosis in rheumatoid arthritis synovial fibroblasts.

    Science.gov (United States)

    Zhai, Yue; Wu, Bo; Li, Jia; Yao, Xi-ying; Zhu, Ping; Chen, Zhi-nan

    2016-01-01

    TNF is highly expressed in synovial tissue of rheumatoid arthritis (RA) patients, where it induces proinflammatory cytokine secretion. However, in other cases, TNF will cause cell death. Considering the abnormal proliferation and activation of rheumatoid arthritis synovioblasts, the proper rate of synovioblast apoptosis could possibly relieve arthritis. However, the mechanism mediating TNF-induced synovioblast survival versus cell death in RA is not fully understood. Our objective was to study the role of CD147 in TNF downstream pathway preference in RA synovioblasts. We found that overexpressing TNF in synovial tissue did not increase the apoptotic level and, in vitro, TNF-induced mild synovioblast apoptosis and promoted IL-6 secretion. CD147, which was highly expressed in rheumatoid arthritis synovial fibroblasts (RASFs), increased the resistance of synovioblasts to apoptosis under TNF stimulation. Downregulating CD147 both increased the apoptotic rate and inhibited IκB kinase (IKK)/IκB/NF-κB pathway-dependent proinflammatory cytokine secretion. Further, we determined that it was the extracellular portion of CD147 and not the intracellular portion that was responsible for synovioblast apoptosis resistance. CD147 monoclonal antibody inhibited TNF-induced proinflammatory cytokine production but had no effect on apoptotic rates. Thus, our study indicates that CD147 is resistant to TNF-induced apoptosis by promoting IKK/IκB/NF-κB pathway, and the extracellular portion of CD147 is the functional region. CD147 inhibits TNF-stimulated RASF apoptosis. CD147 knockdown decreases IKK expression and inhibits NF-κB-related cytokine secretion. CD147's extracellular portion is responsible for apoptosis resistance. CD147 antibody inhibits TNF-related cytokine secretion without additional apoptosis.

  20. Fisetin Induces Apoptosis Through p53-Mediated Up-Regulation of DR5 Expression in Human Renal Carcinoma Caki Cells

    Directory of Open Access Journals (Sweden)

    Kyoung-jin Min

    2017-08-01

    Full Text Available Fisetin is a natural compound found in fruits and vegetables such as strawberries, apples, cucumbers, and onions. Since fisetin can elicit anti-cancer effects, including anti-proliferation and anti-migration, we investigated whether fisetin induced apoptosis in human renal carcinoma (Caki cells. Fisetin markedly induced sub-G1 population and cleavage of poly (ADP-ribose polymerase (PARP, which is a marker of apoptosis, and increased caspase activation. We found that pan-caspase inhibitor (z-VAD-fmk inhibited fisetin-induced apoptosis. In addition, fisetin induced death receptor 5 (DR5 expression at the transcriptional level, and down-regulation of DR5 by siRNA blocked fisetin-induced apoptosis. Furthermore, fisetin induced p53 protein expression through up-regulation of protein stability, whereas down-regulation of p53 by siRNA markedly inhibited fisetin-induced DR5 expression. In contrast, fisetin induced up-regulation of CHOP expression and reactive oxygen species production, which had no effect on fisetin-induced apoptosis. Taken together, our study demonstrates that fisetin induced apoptosis through p53 mediated up-regulation of DR5 expression at the transcriptional level.

  1. FoxP3 inhibits proliferation and induces apoptosis of gastric cancer cells by activating the apoptotic signaling pathway

    International Nuclear Information System (INIS)

    Ma, Gui-Fen; Chen, Shi-Yao; Sun, Zhi-Rong; Miao, Qing; Liu, Yi-Mei; Zeng, Xiao-Qing; Luo, Tian-Cheng; Ma, Li-Li; Lian, Jing-Jing; Song, Dong-Li

    2013-01-01

    Highlights: ► The article revealed FoxP3 gene function in gastric cancer firstly. ► Present the novel roles of FoxP3 in inhibiting proliferation and promoting apoptosis in gastric cancer cells. ► Overexpression of FoxP3 increased proapoptotic molecules and repressed antiapoptotic molecules. ► Silencing of FoxP3 reduced the expression of proapoptotic genes, such as PARP, caspase-3 and caspase-9. ► FoxP3 is sufficient for activating the apoptotic signaling pathway. -- Abstract: Forkhead Box Protein 3 (FoxP3) was identified as a key transcription factor to the occurring and function of the regulatory T cells (Tregs). However, limited evidence indicated its function in tumor cells. To elucidate the precise roles and underlying molecular mechanism of FoxP3 in gastric cancer (GC), we examined the expression of FoxP3 and the consequences of interfering with FoxP3 gene in human GC cell lines, AGS and MKN45, by multiple cellular and molecular approaches, such as immunofluorescence, gene transfection, CCK-8 assay, clone formation assay, TUNEL assay, Flow cytometry, immunoassay and quantities polymerase chain reaction (PCR). As a result, FoxP3 was expressed both in nucleus and cytoplasm of GC cells. Up-regulation of FoxP3 inhibited cell proliferation and promoted cell apoptosis. Overexpression of FoxP3 increased the protein and mRNA levels of proapoptotic molecules, such as poly ADP-ribose polymerase1 (PARP), caspase-3 and caspase-9, and repressed the expression of antiapoptotic molecules, such as cellular inhibitor of apoptosis-1 (c-IAP1) and the long isoform of B cell leukemia/lymphoma-2 (Bcl-2). Furthermore, silencing of FoxP3 by siRNA in GC cells reduced the expression of proapoptotic genes, such as PARP, caspase-3 and caspase-9. Collectively, our findings identify the novel roles of FoxP3 in inhibiting proliferation and inducing apoptosis in GC cells by regulating apoptotic signaling, which could be a promising therapeutic approach for gastric cancer.

  2. Calpain/SHP-1 interaction by honokiol dampening peritoneal dissemination of gastric cancer in nu/nu mice.

    Directory of Open Access Journals (Sweden)

    Shing Hwa Liu

    Full Text Available BACKGROUND: Honokiol, a small-molecular weight natural product, has previously been reported to activate apoptosis and inhibit gastric tumorigenesis. Whether honokiol inhibits the angiogenesis and metastasis of gastric cancer cells remains unknown. METHODOLOGY/PRINCIPAL FINDINGS: We tested the effects of honokiol on angiogenic activity and peritoneal dissemination using in vivo, ex vivo and in vitro assay systems. The signaling responses in human gastric cancer cells, human umbilical vascular endothelial cells (HUVECs, and isolated tumors were detected and analyzed. In a xenograft gastric tumor mouse model, honokiol significantly inhibited the peritoneal dissemination detected by PET/CT technique. Honokiol also effectively attenuated the angiogenesis detected by chick chorioallantoic membrane assay, mouse matrigel plug assay, rat aortic ring endothelial cell sprouting assay, and endothelial cell tube formation assay. Furthermore, honokiol effectively enhanced signal transducer and activator of transcription (STAT-3 dephosphorylation and inhibited STAT-3 DNA binding activity in human gastric cancer cells and HUVECs, which was correlated with the up-regulation of the activity and protein expression of Src homology 2 (SH2-containing tyrosine phosphatase-1 (SHP-1. Calpain-II inhibitor and siRNA transfection significantly reversed the honokiol-induced SHP-1 activity. The decreased STAT-3 phosphorylation and increased SHP-1 expression were also shown in isolated peritoneal metastatic tumors. Honokiol was also capable of inhibiting VEGF generation, which could be reversed by SHP-1 siRNA transfection. CONCLUSIONS/SIGNIFICANCE: Honokiol increases expression and activity of SPH-1 that further deactivates STAT3 pathway. These findings also suggest that honokiol is a novel and potent inhibitor of angiogenesis and peritoneal dissemination of gastric cancer cells, providing support for the application potential of honokiol in gastric cancer therapy.

  3. Autolytic activity of human calpain 7 is enhanced by ESCRT-III-related protein IST1 through MIT-MIM interaction.

    Science.gov (United States)

    Osako, Yohei; Maemoto, Yuki; Tanaka, Ryohei; Suzuki, Hironori; Shibata, Hideki; Maki, Masatoshi

    2010-11-01

    Calpain 7, a mammalian ortholog of yeast Cpl1/Rim13 and fungal PalB, is an atypical calpain that lacks a penta-EF-hand domain. Previously, we reported that a region containing a tandem repeat of microtubule-interacting and transport (MIT) domains in calpain 7 interacts with a subset of endosomal sorting complex required for transport (ESCRT)-III-related proteins, suggesting involvement of calpain 7 in the ESCRT system. Although yeast and fungal calpains are thought to be involved in alkaline adaptation via limited proteolysis of specific transcription factors, proteolytic activity of calpain 7 has not been demonstrated yet. In this study, we investigated the interaction between calpain 7 and a newly reported ESCRT-III family member, increased sodium tolerance-1 (IST1), which possesses two different types of MIT-interacting motifs (MIM1 and MIM2). We found that glutathione-S-transferase (GST)-fused tandem MIT domains of calpain 7 (calpain 7MIT) pulled down FLAG-tagged IST1 expressed in HEK293T cells. Coimmunoprecipitation assays with various deletion or point mutants of epitope-tagged calpain 7 and IST1 revealed that both repetitive MIT domains and MIMs are required for efficient interaction. Direct MIT-MIM binding was confirmed by a pulldown experiment with GST-fused IST1 MIM and purified recombinant calpain 7MIT. Furthermore, we found that the GST-MIM protein enhances the autolysis of purified Strep-tagged monomeric green fluorescent protein (mGFP)-fused calpain 7 (mGFP-calpain 7-Strep). The autolysis was almost completely abolished by 10 mmN-ethylmaleimide but only partially inhibited by 1 mm leupeptin or E-64. The putative catalytic Cys290-substituted mutant (mGFP-calpain 7(C290S)-Strep) showed no autolytic activity. These results demonstrate for the first time that human calpain 7 is proteolytically active, and imply that calpain 7 is activated in the ESCRT system. © 2010 The Authors Journal compilation © 2010 FEBS.

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

    Science.gov (United States)

    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.

  5. Aspirin Induces Apoptosis through Release of Cytochrome c from Mitochondria

    Directory of Open Access Journals (Sweden)

    Katja C. Zimmermann

    2000-01-01

    Full Text Available Nonsteroidal anti-inflammatory drugs (NSAID reduce the risk for cancer, due to their anti proliferative and apoptosis-inducing effects. A critical pathway for apoptosis involves the release of cytochrome c from mitochondria, which then interacts with Apaf-1 to activate caspase proteases that orchestrate cell death. In this study we found that treatment of a human cancer cell line with aspirin induced caspase activation and the apoptotic cell morphology, which was blocked by the caspase inhibitor zVAD-fmk. Further analysis of the mechanism underlying this apoptotic event showed that aspirin induces translocation of Bax to the mitochondria and triggers release of cytochrome c into the cytosol. The release of cytochrome c from mitochondria was inhibited by overexpression of the antiapoptotic protein Bcl-2 and cells that lack Apaf-1 were resistant to aspirin-induced apoptosis. These data provide evidence that the release of cytochrome c is an important part of the apoptotic mechanism of aspirin.