Apoptosis and inflammation

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C. Haanen

1995-01-01

Full Text Available During the last few decades it has been recognized that cell death is not the consequence of accidental injury, but is the expression of a cell suicide programme. Kerr et al. (1972 introduced the term apoptosis. This form of cell death is under the influence of hormones, growth factors and cytokines, which depending upon the receptors present on the target cells, may activate a genetically controlled cell elimination process. During apoptosis the cell membrane remains intact and the cell breaks into apoptotic bodies, which are phagocytosed. Apoptosis, in contrast to necrosis, is not harmful to the host and does not induce any inflammatory reaction. The principal event that leads to inflammatory disease is cell damage, induced by chemical/physical injury, anoxia or starvation. Cell damage means leakage of cell contents into the adjacent tissues, resulting in the capillary transmigration of granulocytes to the injured tissue. The accumulation of neutrophils and release of enzymes and oxygen radicals enhances the inflammatory reaction. Until now there has been little research into the factors controlling the accumulation and the tissue load of granulocytes and their histotoxic products in inflammatory processes. Neutrophil apoptosis may represent an important event in the control of intlamtnation. It has been assumed that granulocytes disintegrate to apoptotic bodies before their fragments are removed by local macrophages. Removal of neutrophils from the inflammatory site without release of granule contents is of paramount importance for cessation of inflammation. In conclusion, apoptotic cell death plays an important role in inflammatory processes and in the resolution of inflammatory reactions. The facts known at present should stimulate further research into the role of neutrophil, eosinophil and macrophage apoptosis in inflammatory diseases.

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

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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.

Apoptosis and Molecular Targeting Therapy in Cancer

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Hassan, Mohamed; Watari, Hidemichi; AbuAlmaaty, Ali; Ohba, Yusuke; Sakuragi, Noriaki

2014-01-01

Apoptosis is the programmed cell death which maintains the healthy survival/death balance in metazoan cells. Defect in apoptosis can cause cancer or autoimmunity, while enhanced apoptosis may cause degenerative diseases. The apoptotic signals contribute into safeguarding the genomic integrity while defective apoptosis may promote carcinogenesis. The apoptotic signals are complicated and they are regulated at several levels. The signals of carcinogenesis modulate the central control points of the apoptotic pathways, including inhibitor of apoptosis (IAP) proteins and FLICE-inhibitory protein (c-FLIP). The tumor cells may use some of several molecular mechanisms to suppress apoptosis and acquire resistance to apoptotic agents, for example, by the expression of antiapoptotic proteins such as Bcl-2 or by the downregulation or mutation of proapoptotic proteins such as BAX. In this review, we provide the main regulatory molecules that govern the main basic mechanisms, extrinsic and intrinsic, of apoptosis in normal cells. We discuss how carcinogenesis could be developed via defective apoptotic pathways or their convergence. We listed some molecules which could be targeted to stimulate apoptosis in different cancers. Together, we briefly discuss the development of some promising cancer treatment strategies which target apoptotic inhibitors including Bcl-2 family proteins, IAPs, and c-FLIP for apoptosis induction. PMID:25013758

Apoptosis in the eye.

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Chahory , Sabine; Torriglia , Alicia

2006-01-01

Apoptosis is a normal component of the development and health of multicellular organisms. Cells die during apoptosis in a controlled, regulated fashion. This form of cell death is very important in eye development as well as in eye pathology. We review in this chapter our current knowledge in this topic.

Apoptosis in mammalian oocytes: a review.

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Tiwari, Meenakshi; Prasad, Shilpa; Tripathi, Anima; Pandey, Ashutosh N; Ali, Irfan; Singh, Arvind K; Shrivastav, Tulsidas G; Chaube, Shail K

2015-08-01

Apoptosis causes elimination of more than 99% of germ cells from cohort of ovary through follicular atresia. Less than 1% of germ cells, which are culminated in oocytes further undergo apoptosis during last phases of oogenesis and depletes ovarian reserve in most of the mammalian species including human. There are several players that induce apoptosis directly or indirectly in oocytes at various stages of meiotic cell cycle. Premature removal of encircling granulosa cells from immature oocytes, reduced levels of adenosine 3',5'-cyclic monophosphate and guanosine 3',5'-cyclic monophosphate, increased levels of calcium (Ca(2+)) and oxidants, sustained reduced level of maturation promoting factor, depletion of survival factors, nutrients and cell cycle proteins, reduced meiotic competency, increased levels of proapoptotic as well as apoptotic factors lead to oocyte apoptosis. The BH3-only proteins also act as key regulators of apoptosis in oocyte within the ovary. Both intrinsic (mitochondria-mediated) as well as extrinsic (cell surface death receptor-mediated) pathways are involved in oocyte apoptosis. BID, a BH3-only protein act as a bridge between both apoptotic pathways and its cleavage activates cell death machinery of both the pathways inside the follicular microenvironment. Oocyte apoptosis leads to the depletion of ovarian reserve that directly affects reproductive outcome of various mammals including human. In this review article, we highlight some of the important players and describe the pathways involved during oocyte apoptosis in mammals.

SIRT6 knockout cells resist apoptosis initiation but not progression: a computational method to evaluate the progression of apoptosis.

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Domanskyi, Sergii; Nicholatos, Justin W; Schilling, Joshua E; Privman, Vladimir; Libert, Sergiy

2017-11-01

Apoptosis is essential for numerous processes, such as development, resistance to infections, and suppression of tumorigenesis. Here, we investigate the influence of the nutrient sensing and longevity-assuring enzyme SIRT6 on the dynamics of apoptosis triggered by serum starvation. Specifically, we characterize the progression of apoptosis in wild type and SIRT6 deficient mouse embryonic fibroblasts using time-lapse flow cytometry and computational modelling based on rate-equations and cell distribution analysis. We find that SIRT6 deficient cells resist apoptosis by delaying its initiation. Interestingly, once apoptosis is initiated, the rate of its progression is higher in SIRT6 null cells compared to identically cultured wild type cells. However, SIRT6 null cells succumb to apoptosis more slowly, not only in response to nutrient deprivation but also in response to other stresses. Our data suggest that SIRT6 plays a role in several distinct steps of apoptosis. Overall, we demonstrate the utility of our computational model to describe stages of apoptosis progression and the integrity of the cellular membrane. Such measurements will be useful in a broad range of biological applications.

Identification of apoptosis-related PLZF target genes

International Nuclear Information System (INIS)

Bernardo, Maria Victoria; Yelo, Estefania; Gimeno, Lourdes; Campillo, Jose Antonio; Parrado, Antonio

2007-01-01

The PLZF gene encodes a BTB/POZ-zinc finger-type transcription factor, involved in physiological development, proliferation, differentiation, and apoptosis. In this paper, we investigate proliferation, survival, and gene expression regulation in stable clones from the human haematopoietic K562, DG75, and Jurkat cell lines with inducible expression of PLZF. In Jurkat cells, but not in K562 and DG75 cells, PLZF induced growth suppression and apoptosis in a cell density-dependent manner. Deletion of the BTB/POZ domain of PLZF abrogated growth suppression and apoptosis. PLZF was expressed with a nuclear speckled pattern distinctively in the full-length PLZF-expressing Jurkat clones, suggesting that the nuclear speckled localization is required for PLZF-induced apoptosis. By microarray analysis, we identified that the apoptosis-inducer TP53INP1, ID1, and ID3 genes were upregulated, and the apoptosis-inhibitor TERT gene was downregulated. The identification of apoptosis-related PLZF target genes may have biological and clinical relevance in cancer typified by altered PLZF expression

Apoptosis imaging with Iodine-124 labeled Annexin V in Fas-mediated hepatic apoptosis model

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Lee, Tae Sup; Woo, Kwang Sun; Chung, Wee Sup; Kim, Kyung Min; Kim, Jae Hong; Chun, Kwon Soo; Choi, Chang Woon; Lim, Sang Moo; Cheon, Gi Jeong

2006-01-01

Healthy cells and, to a lesser extent, malignant cells undergo apoptosis or programmed cell death in response to a variety of stimuli. At an early stage in this process the cell membrane changes so that phosphatidylserine (PS), a lipid normally present on the membrane's inner surface, is exposed on the outer surface. This change in the membrane can be detected by the binding of annexin V to the external PS, and this has formed the basis for an in vitro assay for apoptosis. Blankenberg et al. have applied annexin V to the in vivo imaging of apoptosis by labeling annexin V with 99mTc. With this technique, they have been able to image apoptosis. To extend the use of annexin V to PET, it would be very desirable to iodinate the molecule. The relatively long half-life (4.2 d) of the positron emitting iodine-124 presents several advantages. For example in vivo detection and quantification of longer term biological processes is possible. Also, this cyclotron-generated radionuclide can be prepared well in advance and the established radioiodine labeling techniques can be applied. However, there are some disadvantages such as a relatively low ratio of disintegrations resulting in positrons (23%) and a rather complex decay scheme resulting in several high-energy gamma emissions (0.6- 1.69 MeV). Despite this fact, iodine-124 is still considered to be suitable for positron emission tomography (PET). In this study, we are investigating the feasibility of apoptosis imaging using iodine-124 labeled annexin V in Fas-mediated hepatic apoptosis model

In vivo nuclear imaging of apoptosis

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Lee, Tae Sup; Cheon, Gi Jeong [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

2004-04-01

Apoptosis plays a role in the pathophysiology of many kinds of diseases and in the response of treatment. Compared to the necrosis, the apoptosis a genetically controlled and energy-dependent process which removes the unwanted cells from the body; programmed cell death or cell suicide. During the apoptosis, phosphatidylserine is expressed in the cytoplasmic outer membrane in the early phase. Annexin V, an endogenous human protein (MW=35 kD), has an affinity of about 10{sup -9} M for the phosphatidylserine exposed on the outer membrane of apoptotic cells. Annexin V can be radiolabeled with {sup 99}mTc by HYNIC or EC chelators, which can be used as an radiotracer for the in vivo imaging of apoptosis. In this article, we reviewed the apoptosis, radiolabeling of annexin V, and the experimental and clinical data using annexin V imaging.

Chk2 mediates RITA-induced apoptosis.

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de Lange, J; Verlaan-de Vries, M; Teunisse, A F A S; Jochemsen, A G

2012-06-01

Reactivation of the p53 tumor-suppressor protein by small molecules like Nutlin-3 and RITA (reactivation of p53 and induction of tumor cell apoptosis) is a promising strategy for cancer therapy. The molecular mechanisms involved in the responses to RITA remain enigmatic. Several groups reported the induction of a p53-dependent DNA damage response. Furthermore, the existence of a p53-dependent S-phase checkpoint has been suggested, involving the checkpoint kinase Chk1. We have recently shown synergistic induction of apoptosis by RITA in combination with Nutlin-3, and we observed concomitant Chk2 phosphorylation. Therefore, we investigated whether Chk2 contributes to the cellular responses to RITA. Strikingly, the induction of apoptosis seemed entirely Chk2 dependent. Transcriptional activity of p53 in response to RITA required the presence of Chk2. A partial rescue of apoptosis observed in Noxa knockdown cells emphasized the relevance of p53 transcriptional activity for RITA-induced apoptosis. In addition, we observed an early p53- and Chk2-dependent block of DNA replication upon RITA treatment. Replicating cells seemed more prone to entering RITA-induced apoptosis. Furthermore, the RITA-induced DNA damage response, which was not a secondary effect of apoptosis induction, was strongly attenuated in cells lacking p53 or Chk2. In conclusion, we identified Chk2 as an essential mediator of the cellular responses to RITA.

Embryo apoptosis identification: Oocyte grade or cleavage stage?

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Bakri, Noraina Mohd; Ibrahim, Siti Fatimah; Osman, Nurul Atikah; Hasan, Nurhaslina; Jaffar, Farah Hanan Fathihah; Rahman, Zulaiha Abdul; Osman, Khairul

2015-01-01

Apoptosis is a programed cell death that is vital for tissue homeostasis. However, embryo apoptosis had been known to be related to embryo fragmentation which should be avoided in in vitro fertilization (IVF). The purpose of this study was to evaluate the relationship of embryo apoptosis with the grade of immature oocytes and cleavage stage of in vitro produced (IVP) cattle embryos. This study consisted of 345 oocytes collected through ovary slicing. Immature oocytes were graded as A, B and C. This grading was based on cumulus cell thickness and compactness. All oocytes then underwent an in vitro maturation (IVM) procedure. An IVF was done 24 h after IVM culture. Prior to staining, stage of cleaved embryos was determined and classified as either 2, 4, 8 or >8-cell embryo stage. Apoptosis status of cleaved IVP embryos was determined by using annexin V-FITC staining technique at 48 and 72 h post insemination (hpi). Apoptosis status for each embryo was classified as either early or late. The result showed that there was no significant difference (p > 0.05) of apoptosis status among grade A, B and C embryos. All grades of oocytes showed embryo apoptosis where 1.5% late apoptosis for grade A, 4.5% and 10.4% of early and late apoptosis for grade B and grade C. Early apoptosis was not seen in grade A embryo. We also noted no significant difference (p > 0.05) of apoptosis status between 2, 4, 8 and >8-cell embryo stage. Early apoptosis was also not seen in >8-cell stage. Even though there were no differences in apoptosis expression between the three classes, the cleavage rate of grade A oocytes was significantly higher (p < 0.01) than grade B and grade C. In conclusion, the apoptosis expression in the embryo can occur regardless of the oocyte quality and the cleavage stage of the embryo produced. PMID:26858565

Aspartame-induced apoptosis in PC12 cells.

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

2014-01-01

Aspartame is an artificial sweetner added to many low-calorie foods. The safety of aspartame remains controversial even though there are many studies on its risks. In this study, to understand the physiological effects of trace amounts of artificial sweetners on cells, the effects of aspartame on apoptosis were investigated using a PC12 cell system. In addition, the mechanism of apoptosis induced by aspartame in PC12 cells and effects on apoptotic factors such as cytochrome c, apoptosis-inducing factor, and caspase family proteins were studied by Western blotting and RT-PCR. Aspartame-induced apoptosis in PC12 cells in a dose-dependent manner. In addition, aspartame exposure increased the expressions of caspases 8 and 9, and cytochrome c. These results indicate that aspartame induces apoptosis mainly via mitochondrial pathway involved in apoptosis due to oxigen toxicity. Copyright © 2013 Elsevier B.V. All rights reserved.

Ubiquitin-dependent system controls radiation induced apoptosis

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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)

Induction of Apoptosis and expression of Apoptosis-related gene products in response to radiation in murine tumors

International Nuclear Information System (INIS)

Seong, J. S.

1997-01-01

To analyze the involvement of apoptosis regulatory genes p53, p21 waf1/cip1 , bax and bcl-2 in induction of apoptosis by radiation in murine tumors. The radiation-sensitive ovarian carcinoma OCa-I and the radiation-resistant hepatocarcinoma HCa-I were used. Tumors, 8mm in diameter, were irradiated with 25Gy and at various times after irradiation, ranging from 1 to 48 h, were analyzed histologically for apoptosis and by western blot for alterations in the expression of these genes. The p53 status of the tumors were determined by the polymerase chain reaction-single strand conformation polymorphism assay. Both tumors were positive for wild-type p53. Radiation induced apoptosis in OCa-I but not in HCa-I. Apoptosis developed rapidly, peaked at 2 h after irradiation and returned to almost the background level at 48 h. In OCa-I radiation upregulated the expression of p53, p21 waf1/cip1 , and the bcl-2/bax ratio was decreased. In HCa-I radiation increased the expression of both p53 and p21 waf1/cip1 , although the increase of the latter was small. The bcl-2/bax ratio was greatly increased. In general the observed changes occurred within a few hours after irradiation, and either preceded or coincided with development of apoptosis. The development of apoptosis required upregulation of both p53 and p21 waf1/cip1 as well as a decrease in bcl-2/bax ratio. In contrast, an increase in bcl-2/bax ratio prevented apoptosis in the presence of upregulated p53 and p21 waf1/cip1 . These findings identified the involvement of multiple oncogenes in apoptosis regulation in vivo and demonstrate the complexity that may be associated with the use of a single oncogene assessment for predicting the outcome of cancer therapy with cytotoxic agents. (author)

Induction of Apoptosis and expression of Apoptosis-related gene products in response to radiation in murine tumors

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Seong, J S [Yonsei Univ., Seoul (Korea, Republic of). Coll. of Medicine; Hunter, N R; Milas, L [Texas Univ., Houston, TX (United States)

1997-09-01

To analyze the involvement of apoptosis regulatory genes p53, p21{sup waf1/cip1}, bax and bcl-2 in induction of apoptosis by radiation in murine tumors. The radiation-sensitive ovarian carcinoma OCa-I and the radiation-resistant hepatocarcinoma HCa-I were used. Tumors, 8mm in diameter, were irradiated with 25Gy and at various times after irradiation, ranging from 1 to 48 h, were analyzed histologically for apoptosis and by western blot for alterations in the expression of these genes. The p53 status of the tumors were determined by the polymerase chain reaction-single strand conformation polymorphism assay. Both tumors were positive for wild-type p53. Radiation induced apoptosis in OCa-I but not in HCa-I. Apoptosis developed rapidly, peaked at 2 h after irradiation and returned to almost the background level at 48 h. In OCa-I radiation upregulated the expression of p53, p21{sup waf1/cip1}, and the bcl-2/bax ratio was decreased. In HCa-I radiation increased the expression of both p53 and p21{sup waf1/cip1}, although the increase of the latter was small. The bcl-2/bax ratio was greatly increased. In general the observed changes occurred within a few hours after irradiation, and either preceded or coincided with development of apoptosis. The development of apoptosis required upregulation of both p53 and p21{sup waf1/cip1} as well as a decrease in bcl-2/bax ratio. In contrast, an increase in bcl-2/bax ratio prevented apoptosis in the presence of upregulated p53 and p21{sup waf1/cip1}. These findings identified the involvement of multiple oncogenes in apoptosis regulation in vivo and demonstrate the complexity that may be associated with the use of a single oncogene assessment for predicting the outcome of cancer therapy with cytotoxic agents. (author).

Honey and Apoptosis in Human Gastric Mucosa

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Alireza Ostadrahimi

2012-07-01

Full Text Available Background: Gastric cancer is the fourth most common malignancy in the world. Honey is acomplex mixture of special biological active constituents. Honey possesses antioxidant and antitumorproperties. Nutritional studies have indicated that consumption of honey modulates therisk of developing gastric cancer. On the other hand, apoptosis has been reported to play a decisiverole in precancerous changes. Our chief study was conducted to assess the relationship betweenconsumption of honey and apoptosis in human gastric mucosa.Method: This cross-sectional study was conducted on 98 subjects over 18 years old, referred totwo hospitals in Tabriz, Iran. Subjects were undergone an upper gastrointestinal endoscopy, 62subjects were finally enrolled. Honey consumption was assessed by a Food Frequency Questionnaire(FFQ and apoptosis was detected by TUNEL technique. We tested polynomial curve tofind the best fit between honey consumption and apoptosis.Results: A positive relation between honey consumption and apoptosis was found (P=0.024.Our results indicated that the final and the best fit curve was: apoptosis = 1.714+1.648(honeyamount - 0.533(honey amount2 +1.833×10-5(honey amount7.Conclusion: Honey consumption had positive effects on gastric cancer by inducing apoptosis ingastric mucosa.

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.

Spironolactone induces apoptosis in human mononuclear cells. Association between apoptosis and cytokine suppression

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Mikkelsen, Martin; Sønder, S U; Nersting, J

2006-01-01

Spironolactone (SPIR) has been described to suppress accumulation of pro-inflammatory cytokines. Here, the suppression of TNF-alpha in lipopolysaccharide (LPS)-stimulated mononuclear cell cultures was confirmed. However, SPIR was also found to induce apoptosis, prompting the investigations...... of a possible association between the two effects: The apoptosis-inducing and the cytokine-suppressive effects of SPIR correlated with regard to the effective concentration range. Also, pre-incubation experiments demonstrated a temporal separation of the two effects of ... preceding apoptosis. An association between the two effects was also seen when testing several SPIR analogues. Contrary to TNF-alpha, the levels of IL-1beta increased in SPIR-treated cultures. However, the amount of IL-1beta in the supernatants depended upon the order of SPIR and LPS addition, as IL-1beta...

Potentiation of apoptosis by histone deacetylase inhibitors and doxorubicin combination: cytoplasmic cathepsin B as a mediator of apoptosis in multiple myeloma.

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Cheriyath, V; Kuhns, M A; Kalaycio, M E; Borden, E C

2011-03-15

Although inhibitors of histone deacetylase inhibitors (HDACis) in combination with genotoxins potentiate apoptosis, the role of proteases other than caspases in this process remained elusive. Therefore, we examined the potentiation of apoptosis and related mechanisms of HDACis and doxorubicin combination in a panel of myeloma cell lines and in 25 primary myelomas. At IC(50) concentrations, sodium butyrate (an HDACi) or doxorubicin alone caused little apoptosis. However, their combination potentiated apoptosis and synergistically reduced the viability of myeloma cells independent of p53 and caspase 3-7 activation. Potentiated apoptosis correlated with nuclear translocation of apoptosis-inducing factor, suggesting the induction of caspase 3- and 7-independent pathways. Consistent with this, butyrate and doxorubicin combination significantly increased the activity of cytoplasmic cathepsin B. Inhibition of cathepsin B either with a small-molecule inhibitor or downregulation with a siRNA reversed butyrate- and doxorubicin-potentiated apoptosis. Finally, ex vivo, clinically relevant concentrations of butyrate or SAHA (suberoylanilide hydroxamic acid, vorinostat, an HDACi in clinical testing) in combination with doxorubicin significantly (Pmediating apoptosis potentiated by HDACi and doxorubicin combinations in myeloma. Our results support a molecular model of lysosomal-mitochondrial crosstalk in HDACi- and doxorubicin-potentiated apoptosis through the activation of cathepsin B.

Biomarkers of Chondrocyte Apoptosis and Autophagy in Osteoarthritis

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Musumeci, Giuseppe; Castrogiovanni, Paola; Trovato, Francesca Maria; Weinberg, Annelie Martina; Al-Wasiyah, Mohammad K.; Alqahtani, Mohammed H.; Mobasheri, Ali

2015-01-01

Cell death with morphological and molecular features of apoptosis has been detected in osteoarthritic (OA) cartilage, which suggests a key role for chondrocyte death/survival in the pathogenesis of OA. Identification of biomarkers of chondrocyte apoptosis may facilitate the development of novel therapies that may eliminate the cause or, at least, slow down the degenerative processes in OA. The aim of this review was to explore the molecular markers and signals that induce chondrocyte apoptosis in OA. A literature search was conducted in PubMed, Scopus, Web of Science and Google Scholar using the keywords chondrocyte death, apoptosis, osteoarthritis, autophagy and biomarker. Several molecules considered to be markers of chondrocyte apoptosis will be discussed in this brief review. Molecular markers and signalling pathways associated with chondroycte apoptosis may turn out to be therapeutic targets in OA and approaches aimed at neutralizing apoptosis-inducing molecules may at least delay the progression of cartilage degeneration in OA. PMID:26334269

Apoptosis – is it good or bad?

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Bakir Mehić

2012-08-01

Full Text Available The most widely used classification of mammalian cell death recognizes two types: apoptosis and necrosis. Autophagy, which has been proposed as a third mode of cell death allows a starving cell, or in situations when cell is deprived of growth factors, to survive. Apoptosis, autophagy and necrosis, a particular mode of cell death may predominate, depending of the injury and the type of cell. [1] One very important characteristic of all multicellular organisms is apoptosis, the controlled death of cells. In necrosis, early loss of integrity of the plasma membrane resultant with swelling of the cell and its organelles. A key morphologic feature of apoptosis is collapses of cell and its subcellular components.[2] The distinction between apoptosis and necrosis is due in part to differences in how the plasma membrane participates in these processes. In apoptosis, plasma membrane integrity persists until late in the process. In necrosis, early loss of integrity of the plasma membrane allows an influx of extracellular ions and fluid, with resultant swelling of the cell and its organelles. During that time, on the inside of cell there occurs the cleavage of cytoskeletal proteins by aspartate specific proteases, which thereby collapses subcellular components. Other characteristic features are chromatin condensation, nuclear fragmentation and the formation of plasma membrane blebs. The type and intensity of noxious signals, ATP concentration, cell type, and other factors determine how cell death occurs. Acute myocardial ischemia induces necrosis (because the ischemia precipitates rapid and profound decreases of ATP, whereas chronic congestive heart failure induces apoptosis (with more modest and chronic decreases of ATP. The blockade of a particular pathway of cell death may not prevent the destruction of the cell but may instead recruit an alternative path: antiapoptotic caspase inhibitors cause hyperacute necrosis of hepatocytes and kidney tubular cells

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

Fisetin induces apoptosis through mitochondrial apoptosis pathway in human uveal melanoma cells.

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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.

Mycobacterium tuberculosis effectors interfering host apoptosis signaling.

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Liu, Minqiang; Li, Wu; Xiang, Xiaohong; Xie, Jianping

2015-07-01

Tuberculosis remains a serious human public health concern. The coevolution between its pathogen Mycobacterium tuberculosis and human host complicated the way to prevent and cure TB. Apoptosis plays subtle role in this interaction. The pathogen endeavors to manipulate the apoptosis via diverse effectors targeting key signaling nodes. In this paper, we summarized the effectors pathogen used to subvert the apoptosis, such as LpqH, ESAT-6/CFP-10, LAMs. The interplay between different forms of cell deaths, such as apoptosis, autophagy, necrosis, is also discussed with a focus on the modes of action of effectors, and implications for better TB control.

Apoptosis: Targets in Pancreatic Cancer

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Kalthoff Holger

2003-01-01

Full Text Available Abstract Pancreatic adenocarcinoma is characterized by poor prognosis, because of late diagnosis and lack of response to chemo- and/or radiation therapies. Resistance to apoptosis mainly causes this insensitivity to conventional therapies. Apoptosis or programmed cell death is a central regulator of tissue homeostasis. Certain genetic disturbances of apoptotic signaling pathways have been found in carcinomas leading to tumor development and progression. In the past few years, the knowledge about the complex pathways of apoptosis has strongly increased and new therapeutic approaches based on this knowledge are being developed. This review will focus on the role of apoptotic proteins contributing to pancreatic cancer development and progression and will demonstrate possible targets to influence this deadly disease.

Does Apoptosis Regulate the Function of Retinal Photoreceptors?

OpenAIRE

Halaby, Reginald

2012-01-01

Apoptosis, or programmed cell death, is an integral component of developmental biology, embryology, and anatomy. All eukaryotic cells possess the molecular machinery necessary to execute apoptosis. However, dysregulated apoptosis in the form of too much or too little cell death results in diseases such as Alzheimer’s disease, autoimmune disorders, and cancer. It is postulated that apoptosis of the photoreceptors in the retina plays a vital role in mediating vision, and evidence is presented h...

Activation of human herpesvirus replication by apoptosis.

Science.gov (United States)

Prasad, Alka; Remick, Jill; Zeichner, Steven L

2013-10-01

A central feature of herpesvirus biology is the ability of herpesviruses to remain latent within host cells. Classically, exposure to inducing agents, like activating cytokines or phorbol esters that stimulate host cell signal transduction events, and epigenetic agents (e.g., butyrate) was thought to end latency. We recently showed that Kaposi's sarcoma-associated herpesvirus (KSHV, or human herpesvirus-8 [HHV-8]) has another, alternative emergency escape replication pathway that is triggered when KSHV's host cell undergoes apoptosis, characterized by the lack of a requirement for the replication and transcription activator (RTA) protein, accelerated late gene kinetics, and production of virus with decreased infectivity. Caspase-3 is necessary and sufficient to initiate the alternative replication program. HSV-1 was also recently shown to initiate replication in response to host cell apoptosis. These observations suggested that an alternative apoptosis-triggered replication program might be a general feature of herpesvirus biology and that apoptosis-initiated herpesvirus replication may have clinical implications, particularly for herpesviruses that almost universally infect humans. To explore whether an alternative apoptosis-initiated replication program is a common feature of herpesvirus biology, we studied cell lines latently infected with Epstein-Barr virus/HHV-4, HHV-6A, HHV-6B, HHV-7, and KSHV. We found that apoptosis triggers replication for each HHV studied, with caspase-3 being necessary and sufficient for HHV replication. An alternative apoptosis-initiated replication program appears to be a common feature of HHV biology. We also found that commonly used cytotoxic chemotherapeutic agents activate HHV replication, which suggests that treatments that promote apoptosis may lead to activation of latent herpesviruses, with potential clinical significance.

Mitochondrial dysfunction in lyssavirus-induced apoptosis.

Science.gov (United States)

Gholami, Alireza; Kassis, Raïd; Real, Eléonore; Delmas, Olivier; Guadagnini, Stéphanie; Larrous, Florence; Obach, Dorothée; Prevost, Marie-Christine; Jacob, Yves; Bourhy, Hervé

2008-05-01

Lyssaviruses are highly neurotropic viruses associated with neuronal apoptosis. Previous observations have indicated that the matrix proteins (M) of some lyssaviruses induce strong neuronal apoptosis. However, the molecular mechanism(s) involved in this phenomenon is still unknown. We show that for Mokola virus (MOK), a lyssavirus of low pathogenicity, the M (M-MOK) targets mitochondria, disrupts the mitochondrial morphology, and induces apoptosis. Our analysis of truncated M-MOK mutants suggests that the information required for efficient mitochondrial targeting and dysfunction, as well as caspase-9 activation and apoptosis, is held between residues 46 and 110 of M-MOK. We used a yeast two-hybrid approach, a coimmunoprecipitation assay, and confocal microscopy to demonstrate that M-MOK physically associates with the subunit I of the cytochrome c (cyt-c) oxidase (CcO) of the mitochondrial respiratory chain; this is in contrast to the M of the highly pathogenic Thailand lyssavirus (M-THA). M-MOK expression induces a significant decrease in CcO activity, which is not the case with M-THA. M-MOK mutations (K77R and N81E) resulting in a similar sequence to M-THA at positions 77 and 81 annul cyt-c release and apoptosis and restore CcO activity. As expected, the reverse mutations, R77K and E81N, introduced in M-THA induce a phenotype similar to that due to M-MOK. These features indicate a novel mechanism for energy depletion during lyssavirus-induced apoptosis.

Effect of sevoflurane on human neutrophil apoptosis.

LENUS (Irish Health Repository)

Tyther, R

2012-02-03

BACKGROUND AND OBJECTIVE: Both chronic occupational exposure to volatile anaesthetic agents and acute in vitro exposure of neutrophils to isoflurane have been shown to inhibit the rate of apoptosis of human neutrophils. It is possible that inhibition of neutrophil apoptosis arises through delaying mitochondrial membrane potential collapse. We assessed mitochondrial depolarization and apoptosis in unexposed neutrophils and neutrophils exposed to sevoflurane in vivo. METHODS: A total of 20 mL venous blood was withdrawn pre- and postinduction of anaesthesia, the neutrophils isolated and maintained in culture. At 1, 12 and 24 h in culture, the percentage of neutrophil apoptosis was assessed by dual staining with annexin V-FITC and propidium iodide. Mitochondrial depolarization was measured using the dual emission styryl dye JC-1. RESULTS: Apoptosis was significantly inhibited in neutrophils exposed to sevoflurane in vivo at 24 (exposed: 38 (12)% versus control: 28 (11)%, P = 0.001), but not at 1 or 12 h, in culture. Mitochondrial depolarization was not delayed in neutrophils exposed to sevoflurane. CONCLUSIONS: The most important findings are that sevoflurane inhibits neutrophil apoptosis in vivo and that inhibition is not mediated primarily by an effect on mitochondrial depolarization.

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

Energy Technology Data Exchange (ETDEWEB)

Li, Fengbo [Tianjin Institute of Orthopedics in Traditional Chinese and Western Medicine, No. 155, Munan Road, Tianjin TJ 300050 (China); Graduate School of Tianjin Medical University, No. 22, Qixiangtai Street, Heping District, Tianjin 300070 (China); Sun, Xiaolei; Ma, Jianxiong [Tianjin Institute of Orthopedics in Traditional Chinese and Western Medicine, No. 155, Munan Road, Tianjin TJ 300050 (China); Ma, Xinlong, E-mail: gengxiao502@163.com [Tianjin Institute of Orthopedics in Traditional Chinese and Western Medicine, No. 155, Munan Road, Tianjin TJ 300050 (China); Zhao, Bin; Zhang, Yang; Tian, Peng [Tianjin Institute of Orthopedics in Traditional Chinese and Western Medicine, No. 155, Munan Road, Tianjin TJ 300050 (China); Li, Yanjun [Graduate School of Tianjin Medical University, No. 22, Qixiangtai Street, Heping District, Tianjin 300070 (China); Han, Zhe [Tianjin Institute of Orthopedics in Traditional Chinese and Western Medicine, No. 155, Munan Road, Tianjin TJ 300050 (China)

2014-09-26

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

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

International Nuclear Information System (INIS)

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

2014-01-01

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

Host and Viral Factors in HIV-Mediated Bystander Apoptosis

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Garg, Himanshu; Joshi, Anjali

2017-01-01

Human immunodeficiency virus (HIV) infections lead to a progressive loss of CD4 T cells primarily via the process of apoptosis. With a limited number of infected cells and vastly disproportionate apoptosis in HIV infected patients, it is believed that apoptosis of uninfected bystander cells plays a significant role in this process. Disease progression in HIV infected individuals is highly variable suggesting that both host and viral factors may influence HIV mediated apoptosis. Amongst the viral factors, the role of Envelope (Env) glycoprotein in bystander apoptosis is well documented. Recent evidence on the variability in apoptosis induction by primary patient derived Envs underscores the role of Env glycoprotein in HIV disease. Amongst the host factors, the role of C-C Chemokine Receptor type 5 (CCR5), a coreceptor for HIV Env, is also becoming increasingly evident. Polymorphisms in the CCR5 gene and promoter affect CCR5 cell surface expression and correlate with both apoptosis and CD4 loss. Finally, chronic immune activation in HIV infections induces multiple defects in the immune system and has recently been shown to accelerate HIV Env mediated CD4 apoptosis. Consequently, those factors that affect CCR5 expression and/or immune activation in turn indirectly regulate HIV mediated apoptosis making this phenomenon both complex and multifactorial. This review explores the complex role of various host and viral factors in determining HIV mediated bystander apoptosis. PMID:28829402

Transcriptome analysis of Spodoptera frugiperda Sf9 cells reveals putative apoptosis-related genes and a preliminary apoptosis mechanism induced by azadirachtin.

Science.gov (United States)

Shu, Benshui; Zhang, Jingjing; Sethuraman, Veeran; Cui, Gaofeng; Yi, Xin; Zhong, Guohua

2017-10-16

As an important botanical pesticide, azadirachtin demonstrates broad insecticidal activity against many agricultural pests. The results of a previous study indicated the toxicity and apoptosis induction of azadirachtin in Spodoptera frugiperda Sf9 cells. However, the lack of genomic data has hindered a deeper investigation of apoptosis in Sf9 cells at a molecular level. In the present study, the complete transcriptome data for Sf9 cell line was accomplished using Illumina sequencing technology, and 97 putative apoptosis-related genes were identified through BLAST and KEGG orthologue annotations. Fragments of potential candidate apoptosis-related genes were cloned, and the mRNA expression patterns of ten identified genes regulated by azadirachtin were examined using qRT-PCR. Furthermore, Western blot analysis showed that six putative apoptosis-related proteins were upregulated after being treated with azadirachtin while the protein Bcl-2 were downregulated. These data suggested that both intrinsic and extrinsic apoptotic signal pathways comprising the identified potential apoptosis-related genes were potentially active in S. frugiperda. In addition, the preliminary results revealed that caspase-dependent or caspase-independent apoptotic pathways could function in azadirachtin-induced apoptosis in Sf9 cells.

Apoptosis and Necrosis in the Liver

Science.gov (United States)

Guicciardi, Maria Eugenia; Malhi, Harmeet; Mott, Justin L.; Gores, Gregory J.

2013-01-01

Because of its unique function and anatomical location, the liver is exposed to a multitude of toxins and xenobiotics, including medications and alcohol, as well as to infection by hepatotropic viruses, and therefore, is highly susceptible to tissue injury. Cell death in the liver occurs mainly by apoptosis or necrosis, with apoptosis also being the physiologic route to eliminate damaged or infected cells and to maintain tissue homeostasis. Liver cells, especially hepatocytes and cholangiocytes, are particularly susceptible to death receptor-mediated apoptosis, given the ubiquitous expression of the death receptors in the organ. In a quite unique way, death receptor-induced apoptosis in these cells is mediated by both mitochondrial and lysosomal permeabilization. Signaling between the endoplasmic reticulum and the mitochondria promotes hepatocyte apoptosis in response to excessive free fatty acid generation during the metabolic syndrome. These cell death pathways are partially regulated by microRNAs. Necrosis in the liver is generally associated with acute injury (i.e., ischemia/reperfusion injury) and has been long considered an unregulated process. Recently, a new form of “programmed” necrosis (named necroptosis) has been described: the role of necroptosis in the liver has yet to be explored. However, the minimal expression of a key player in this process in the liver suggests this form of cell death may be uncommon in liver diseases. Because apoptosis is a key feature of so many diseases of the liver, therapeutic modulation of liver cell death holds promise. An updated overview of these concepts is given in this article. PMID:23720337

Apigenin induces apoptosis by targeting inhibitor of apoptosis proteins and Ku70–Bax interaction in prostate cancer

Science.gov (United States)

Shukla, Sanjeev; Fu, Pingfu; Gupta, Sanjay

2014-01-01

Dysfunction of the apoptotic pathway in prostate cancer cells confers apoptosis resistance towards various therapies. A novel strategy to overcome resistance is to directly target the apoptotic pathway in cancer cells. Apigenin, an anticancer agent, selectively toxic to cancer cells induces cell cycle arrest and apoptosis through mechanisms which are not fully explored. In the present study we provide novel insight into the mechanisms of apoptosis induction by apigenin. Treatment of androgen-refractory human prostate cancer PC-3 and DU145 cells with apigenin resulted in dose-dependent suppression of XIAP, c-IAP1, c-IAP2 and survivin protein levels. Apigenin treatment resulted in significant decrease in cell viability and apoptosis induction with the increase of cytochrome C in time-dependent manner. These effects of apigenin were accompanied by decrease in Bcl-xL and Bcl-2 and increase in the active form of Bax protein. The apigenin-mediated increase in Bax was due to dissociation of Bax from Ku70 which is essential for apoptotic activity of Bax. Apigenin treatment resulted in the inhibition of class I histone deacetylases and HDAC1 protein expression, thereby increasing the acetylation of Ku70 and the dissociation of Bax resulting in apoptosis of cancer cells. Furthermore, apigenin significantly reduced HDAC1 occupancy at the XIAP promoter, suggesting that histone deacetylation might be critical for XIAP downregulation. These results suggest that apigenin targets inhibitor of apoptosis proteins and Ku70–Bax interaction in the induction of apoptosis in prostate cancer cells and in athymic nude mouse xenograft model endorsing its in vivo efficacy. PMID:24563225

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

Directory of Open Access Journals (Sweden)

Gretel G. Pellegrini

2016-07-01

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

Cord blood stem cell-mediated induction of apoptosis in glioma downregulates X-linked inhibitor of apoptosis protein (XIAP.

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Venkata Ramesh Dasari

2010-07-01

Full Text Available XIAP (X-linked inhibitor of apoptosis protein is one of the most important members of the apoptosis inhibitor family. XIAP is upregulated in various malignancies, including human glioblastoma. It promotes invasion, metastasis, growth and survival of malignant cells. We hypothesized that downregulation of XIAP by human umbilical cord blood mesenchymal stem cells (hUCBSC in glioma cells would cause them to undergo apoptotic death.We observed the effect of hUCBSC on two malignant glioma cell lines (SNB19 and U251 and two glioma xenograft cell lines (4910 and 5310. In co-cultures of glioma cells with hUCBSC, proliferation of glioma cells was significantly inhibited. This is associated with increased cytotoxicity of glioma cells, which led to glioma cell death. Stem cells induced apoptosis in glioma cells, which was evaluated by TUNEL assay, FACS analyses and immunoblotting. The induction of apoptosis is associated with inhibition of XIAP in co-cultures of hUCBSC. Similar results were obtained by the treatment of glioma cells with shRNA to downregulate XIAP (siXIAP. Downregulation of XIAP resulted in activation of caspase-3 and caspase-9 to trigger apoptosis in glioma cells. Apoptosis is characterized by the loss of mitochondrial membrane potential and upregulation of mitochondrial apoptotic proteins Bax and Bad. Cell death of glioma cells was marked by downregulation of Akt and phospho-Akt molecules. We observed similar results under in vivo conditions in U251- and 5310-injected nude mice brains, which were treated with hUCBSC. Under in vivo conditions, Smac/DIABLO was found to be colocalized in the nucleus, showing that hUCBSC induced apoptosis is mediated by inhibition of XIAP and activation of Smac/DIABLO.Our results indicate that downregulation of XIAP by hUCBSC treatment induces apoptosis, which led to the death of the glioma cells and xenograft cells. This study demonstrates the therapeutic potential of XIAP and hUCBSC to treat malignant

Visualizing Vpr-induced G2 arrest and apoptosis.

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Tomoyuki Murakami

Full Text Available Vpr is an accessory protein of human immunodeficiency virus type 1 (HIV-1 with multiple functions. The induction of G2 arrest by Vpr plays a particularly important role in efficient viral replication because the transcriptional activity of the HIV-1 long terminal repeat is most active in G2 phase. The regulation of apoptosis by Vpr is also important for immune suppression and pathogenesis during HIV infection. However, it is not known whether Vpr-induced apoptosis depends on the ability of Vpr to induce G2 arrest, and the dynamics of Vpr-induced G2 arrest and apoptosis have not been visualized. We performed time-lapse imaging to examine the temporal relationship between Vpr-induced G2 arrest and apoptosis using HeLa cells containing the fluorescent ubiquitination-based cell cycle indicator2 (Fucci2. The dynamics of G2 arrest and subsequent long-term mitotic cell rounding in cells transfected with the Vpr-expression vector were visualized. These cells underwent nuclear mis-segregation after prolonged mitotic processes and then entered G1 phase. Some cells subsequently displayed evidence of apoptosis after prolonged mitotic processes and nuclear mis-segregation. Interestingly, Vpr-induced apoptosis was seldom observed in S or G2 phase. Likewise, visualization of synchronized HeLa/Fucci2 cells infected with an adenoviral vector expressing Vpr clearly showed that Vpr arrests the cell cycle at G2 phase, but does not induce apoptosis at S or G2 phase. Furthermore, time-lapse imaging of HeLa/Fucci2 cells expressing SCAT3.1, a caspase-3-sensitive fusion protein, clearly demonstrated that Vpr induces caspase-3-dependent apoptosis. Finally, to examine whether the effects of Vpr on G2 arrest and apoptosis were reversible, we performed live-cell imaging of a destabilizing domain fusion Vpr, which enabled rapid stabilization and destabilization by Shield1. The effects of Vpr on G2 arrest and subsequent apoptosis were reversible. This study is the first to

Cathepsin B is involved in the heat shock induced cardiomyocytes apoptosis as well as the anti-apoptosis effect of HSP-70.

Science.gov (United States)

Hsu, Shu-Fen; Hsu, Chuan-Chih; Cheng, Bor-Chih; Lin, Cheng-Hsien

2014-11-01

Cathepsin B is one of the major lysosomal cysteine proteases that plays an important role in apoptosis. Herein, we investigated whether Cathepsin B is involved in cardiomyocyte apoptosis caused by hyperthermic injury (HI) and heat shock protein (HSP)-70 protects these cells from HI-induced apoptosis mediated by Cathepsin. HI was produced in H9C2 cells by putting them in a circulating 43 °C water bath for 120 min, whereas preinduction of HSP-70 was produced in H9C2 cells by mild heat preconditioning (or putting them in 42 °C water bath for 30 min) 8 h before the start of HI. It was found that HI caused both cardiomyocyte apoptosis and increased Cathepsin B activity in H9C2 cells. E-64-c, in addition to reducing Cathepsin B activity, significantly attenuated HI-induced cardiomyocyte apoptosis (evidenced by increased apoptotic cell numbers, increased tuncated Bid (t-Bid), increased cytochrome C, increased caspase-9/-3, and decreased Bcl-2/Bax) in H9C2 cells. In addition, preinduction of HSP-70 by mild heat preconditioning or inhibition of HSP-70 by Tripolide significantly attenuated or exacerbated respectively both the cardiomyocyte apoptosis and increased Cathepsin B activity in H9C2 cells. Furthermore, the beneficial effects of pre-induction of HSP-70 by mild heat production in reducing both cardiomyocyte apoptosis and increased Cathepsin B activity caused by HI can be significantly reduced by Triptolide preconditioning. These results indicate that Cathepsin B is involved in HI-induced cardiomyocyte apoptosis in H9C2 cells and HSP-70 protects these cells from HI-induced cardiomyocyte apoptosis through Cathepsin B pathways.

Research Advances on Pathways of Nickel-Induced Apoptosis

Science.gov (United States)

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

2015-01-01

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

Signaling Pathways in Cardiac Myocyte Apoptosis

Science.gov (United States)

Xia, Peng; Liu, Yuening

2016-01-01

Cardiovascular diseases, the number 1 cause of death worldwide, are frequently associated with apoptotic death of cardiac myocytes. Since cardiomyocyte apoptosis is a highly regulated process, pharmacological intervention of apoptosis pathways may represent a promising therapeutic strategy for a number of cardiovascular diseases and disorders including myocardial infarction, ischemia/reperfusion injury, chemotherapy cardiotoxicity, and end-stage heart failure. Despite rapid growth of our knowledge in apoptosis signaling pathways, a clinically applicable treatment targeting this cellular process is currently unavailable. To help identify potential innovative directions for future research, it is necessary to have a full understanding of the apoptotic pathways currently known to be functional in cardiac myocytes. Here, we summarize recent progress in the regulation of cardiomyocyte apoptosis by multiple signaling molecules and pathways, with a focus on the involvement of these pathways in the pathogenesis of heart disease. In addition, we provide an update regarding bench to bedside translation of this knowledge and discuss unanswered questions that need further investigation. PMID:28101515

Molecular imaging of apoptosis in cancer

International Nuclear Information System (INIS)

Hakumaeki, Juhana M.; Liimatainen, Timo

2005-01-01

Apoptosis plays an important role in cancer. Mechanisms hindering its action are implicated in a number of malignancies. Also, the induction of apoptosis plays a pivotal role in non-surgical cancer treatment regimes such as irradiation, chemotherapy, or hormones. Recent advanced in imaging science have made it now possible for us to detect and visualize previously inaccessible and even unrecognized biological phenomena in cells and tissue undergoing apoptosis in vivo. Not only are these imaging techniques painting an intriguing picture of the spatiotemporal characteristics and metabolic and biophysical of apoptosis in situ, but they are expected to have an ever increasing impact in preclinical testing and design of new anticancer agents as well. Rapid and accurate visualization of apoptotic response in the clinical settings can also be of significant diagnostic and prognostic worth. With the advent of molecular medicine and patient-tailored treatment options and therapeutic agents, such monitoring techniques are becoming paramount

APOPTOSIS DURING HUMAN FETAL KIDNEY DEVELOPMENT

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Rade Čukuranović

2005-01-01

Full Text Available Kidney morphogenesis is a complex and stepwise process. The formation of mature kidney in mammals is preceded by two primitive embryonic kidneys known as pronephros and mesonephros. Metanephros develops as a result of reciprocal inductive interactions between two primordial mesodermal derivates: ureteric bud, an epithelial outgrowth of the Wolffian duct, and metanephric blastema, a group of mesenchymal cells. The ureteric bud induces the metanephric mesenchyme to differentiate and form nephrons, whilst the metanephric mesenchyme induces the ureteric bud to grow and branch to form collecting ducts. The nephron goes through four developmental stages, which are described as: 1 vesicle, 2 comma-shaped and S-shaped stages, 3 developing capillary loop, and finally 4 maturing glomerulus. Apoptosis (programmed cell death is a predominant form of physiological cell death, by which organism eliminate unwanted or damaged cells. It is the major component of normal development and disease. Apoptosis is the result of series of biochemical processes happening in certain order in a dying cell, among which the most important is activation of enzyme families called caspases which influence different cell components. Apoptosis is characterized by membrane blebbing, shrinkage of the cell, nuclear fragmentation and chromatin condensation. Organelles are preserved almost intact. Cell surface molecules change. A variety of physiological and pathological stimuli can initiate apoptosis. They act via receptor mechanisms, through biochemical agents, or cause DNA and cell membrane damage. Apoptosis is an important component of fetal development. It is thought that apoptosis is the one of the main regulatory events involved in kidney morphogenesis, considering that among great number of developed cells, only a few of them are involved in the developing program by escaping apoptosis. In any period during kidney development about 3 to 5%of cells are apoptotic. Thorough

Cyclin-dependent kinases regulate apoptosis of intestinal epithelial cells

Science.gov (United States)

Bhattacharya, Sujoy; Ray, Ramesh M.; Johnson, Leonard R.

2014-01-01

Homeostasis of the gastrointestinal epithelium is dependent upon a balance between cell proliferation and apoptosis. Cyclin-dependent kinases (Cdks) are well known for their role in cell proliferation. Previous studies from our group have shown that polyamine-depletion of intestinal epithelial cells (IEC-6) decreases cyclin-dependent kinase 2 (Cdk2) activity, increases p53 and p21Cip1 protein levels, induces G1 arrest, and protects cells from camptothecin (CPT)-induced apoptosis. Although emerging evidence suggests that members of the Cdk family are involved in the regulation of apoptosis, their roles directing apoptosis of IEC-6 cells are not known. In this study, we report that inhibition of Cdk1, 2, and 9 (with the broad range Cdk inhibitor, AZD5438) in proliferating IEC-6 cells triggered DNA damage, activated p53 signaling, inhibited proliferation, and induced apoptosis. By contrast, inhibition of Cdk2 (with NU6140) increased p53 protein and activity, inhibited proliferation, but had no effect on apoptosis. Notably, AZD5438 sensitized, whereas, NU6140 rescued proliferating IEC-6 cells from CPT-induced apoptosis. However, in colon carcinoma (Caco2) cells with mutant p53, treatment with either AZD5438 or NU6140 blocked proliferation, albeit more robustly with AZD5438. Both Cdk inhibitors induced apoptosis in Caco2 cells in a p53-independent manner. In serum starved quiescent IEC-6 cells, both AZD5438 and NU6140 decreased TNF- /CPT-induced activation of p53 and, consequently, rescued cells from apoptosis, indicating that sustained Cdk activity is required for apoptosis of quiescent cells. Furthermore, AZD5438 partially reversed the protective effect of polyamine depletion whereas NU6140 had no effect. Together, these results demonstrate that Cdks possess opposing roles in the control of apoptosis in quiescent and proliferating cells. In addition, Cdk inhibitors uncouple proliferation from apoptosis in a p53-dependent manner. PMID:24242917

Mitochondrial disfunction and apoptosis in leukemia cells

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Annamaria PALLAG

2008-05-01

Full Text Available Apoptosis or programmed cell death is a process which involves the intentional degradation of the cell from the inside, the participation of the mitochondria to propagate the apoptotic signal, the alteration of the phospholipid cell membrane composition, the perturbation and alteration of the cell metabolism.The antineoplastic drugs is inducing the apoptotic process in the sensitive cells.It have been studied acute lymphoblastic leukemia cells. Using Annexin V-PE Apoptosis Detection Kit and flow cytometer, the amount of cells undergoing apoptosis, in various stages of the antineoplasic treatment, was detected. At the same time, were monitored, the serum level of malondialdehyde. The results obtained confirm the alteration of the mitochondrial metabolism. We can observed the mitochondrial dysfunction role in cell apoptosis.

Assessment of radiation induced apoptosis in lymphocyte subpopulations

International Nuclear Information System (INIS)

Perez, M. del R.; Dubner, Diana L.; Michelin, Severino; Gisone, Pablo A.; Barboza, Marcos

2001-01-01

Apoptosis is the main form of radioinduced cell death. The lymphocytes, highly radiosensitive cells, dead in interphase by apoptosis even after very low doses. It has been demonstrated that the various peripheral blood lymphocyte (PBL) types display clear differences in their radiosensitivity . The purpose of this work was the characterization of radioinduced apoptosis in total PBL and in helper and cytotoxic T-lymphocytes. Blood samples were irradiated with a gamma source with doses between 0,5 and 4 Gy, dose-rate 0,8 Gy/min. Apoptosis was evaluated at different times post irradiation (p.i.) by conventional and fluorescence microscopy. Fragmentation of DNA was determined by electrophoresis in agarose gels. Apoptosis was quantified flow cytometrically by light scatter gram and determining the percent of fixed cells stained with propidium iodide that exhibited a reduced DNA content. FITC-labelled Annexin V was used to bind cell membrane phosphatidylserine which is aberrantly exposed during apoptosis. As an additional approach for the evaluation of apoptosis we measured the mitochondrial transmembrane potential by using the cationic dye 3,3 dihexyl oxacarbocyanine iodide (DiOC 6 ). Chromatin condensation and apoptotic bodies were microscopically observed and internucleosomal fragmentation was revealed in electrophoresis gels. Apoptotic cell fraction displayed a dose-dependent increase with a higher radiosensitivity for CD8 T-lymphocytes. These results suggest that quantification of PBL apoptosis could be an useful biological indicator in accidental overexposures and could also provide an useful predictive test for individual radiosensitivity. The higher radiosensitivity revealed by CD8 subset could allow a better discrimination of this phenomenon. (author)

Fullerene and apoptosis

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M. A. Orlova

2013-01-01

Full Text Available Fullerene derivatives superfamily attracts a serious attention as antiviral and anticancer agents and drug delivery carriers as well. A large number of such fullerene С60 derivatives obtained to date. However, there is an obvious deficit of information about causes and mechanisms of immediately and long-term consequences of their effects in vivo which is a true obstacle on the way leading to practical medical use of them. First, this concerns their impact on the proliferation, apoptosis and necrosis regulation. Fullerene nanoparticle functionalization type, their sizes and surface nanopathology are of great importance to further promoting of either cytoprotective or cytotoxic effects. This lecture provides modern concept analysis regarding fullerenes effects on apoptosis pathway in normal and tumor cells.

Apoptosis-Dependent and Apoptosis-Independent Functions Bim in Prostate Cancer Cells

National Research Council Canada - National Science Library

Liu, Junwei

2004-01-01

... (death, survival, proliferation/division, etc). Our hypothesis is that, under normal, unstimulated conditions, with its apoptotic function blocked, the upregulated Bim in PCa cells play an apoptosis-independent function...

Aspartame-induced apoptosis in PC12 cells

OpenAIRE

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

2014-01-01

Aspartame is an artificial sweetner added to many low-calorie foods. The safety of aspartame remains controversial even though there are many studies on its risks. In this study, to understand the physiological effects of trace amounts of artificial sweetners on cells, the effects of aspartame on apoptosis were investigated using a PC12 cell system. In addition, the mechanism of apoptosis induced by aspartame in PC12 cells and effects on apoptotic factors such as cytochrome c, apoptosis-induc...

The apoptosis of CHO cells induced by X-rays

International Nuclear Information System (INIS)

Lu Zhaohong; Zhao Jingyong; Zhu Mingqing; Shi Xijin; Wang Chunlei

2004-01-01

The work is to study the mechanism of toxic effects on reproductive system and apoptosis of Chinese hamster ovary (CHO) cells induced by X-rays. CHO cell was exposed to X-rays 2 to 20 Gy. Apoptosis and morphological changes of the cells were observed by fluorescent microscopy and flow cytometry analyzer with double staining with Annexin V/PI. The apoptosis could be observed at 24, 48 and 72h after the exposure, but it was more obvious 48 and 72 h after the exposure. Rate of the apoptosis increased along with radiation dose were elevated. Some morphological changes, such as irregular agglomerate of chromatins, pycnosis and periphery distribution of nuclei, crescent-moon-like cells, small apoptosis body, were observed. Radiation results DNA damage in the CHO cells, and the damage cannot be repaired, hence the induced cell apoptosis. (authors)

Sequential activation of proteases in radiation induced apoptosis

International Nuclear Information System (INIS)

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

Tumor necrosis factor related apoptosis inducing ligand triggers apoptosis in dividing but not in differentiating human epidermal keratinocytes

NARCIS (Netherlands)

Jansen, Bastiaan J. H.; van Ruissen, Fred; Cerneus, Stefanie; Cloin, Wendy; Bergers, Mieke; van Erp, Piet E. J.; Schalkwijk, Joost

2003-01-01

Using serial analysis of gene expression we have previously identified the expression of several pro-apoptotic and anti-apoptotic genes in cultured human primary epidermal keratinocytes, including tumor necrosis factor related apoptosis inducing ligand (TRAIL). TRAIL is a potent inducer of apoptosis

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.

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.

Reaper-Induced Apoptosis

National Research Council Canada - National Science Library

Perry, Jennifer

2005-01-01

Reaper is a central regulator of apoptosis in the fly, Drosophila melanogaster. At the start of this proposal our laboratory identified what was believed to be a pro-apoptotic human homolog of Reaper...

Apoptosis-induced lymphopenia in sepsis and other severe injuries.

Science.gov (United States)

Girardot, Thibaut; Rimmelé, Thomas; Venet, Fabienne; Monneret, Guillaume

2017-02-01

Sepsis and other acute injuries such as severe trauma, extensive burns, or major surgeries, are usually followed by a period of marked immunosuppression. In particular, while lymphocytes play a pivotal role in immune response, their functions and numbers are profoundly altered after severe injuries. Apoptosis plays a central role in this process by affecting immune response at various levels. Indeed, apoptosis-induced lymphopenia duration and depth have been associated with higher risk of infection and mortality in various clinical settings. Therapies modulating apoptosis represent an interesting approach to restore immune competence after acute injury, although their use in clinical practice still presents several limitations. After briefly describing the apoptosis process in physiology and during severe injuries, we will explore the immunological consequences of injury-induced lymphocyte apoptosis, and describe associations with clinically relevant outcomes in patients. Therapeutic perspectives targeting apoptosis will also be discussed.

Fas-induced apoptosis in malnourished infants

African Journals Online (AJOL)

EL-HAKIM

deprivation in animals, including man11. Factor of apoptosis signal (Fas) induces apoptosis in activated T cells when they are repeatedly stimulated by antigen and functions to maintain T cell tolerance by deleting auto reactive cells12. The functional role of Fas (CD95) in the immune system has been examined in a variety ...

Genetic Signatures of HIV-1 Envelope-mediated Bystander Apoptosis

Science.gov (United States)

Joshi, Anjali; Lee, Raphael T. C.; Mohl, Jonathan; Sedano, Melina; Khong, Wei Xin; Ng, Oon Tek; Maurer-Stroh, Sebastian; Garg, Himanshu

2014-01-01

The envelope (Env) glycoprotein of HIV is an important determinant of viral pathogenesis. Several lines of evidence support the role of HIV-1 Env in inducing bystander apoptosis that may be a contributing factor in CD4+ T cell loss. However, most of the studies testing this phenomenon have been conducted with laboratory-adapted HIV-1 isolates. This raises the question of whether primary Envs derived from HIV-infected patients are capable of inducing bystander apoptosis and whether specific Env signatures are associated with this phenomenon. We developed a high throughput assay to determine the bystander apoptosis inducing activity of a panel of primary Envs. We tested 38 different Envs for bystander apoptosis, virion infectivity, neutralizing antibody sensitivity, and putative N-linked glycosylation sites along with a comprehensive sequence analysis to determine if specific sequence signatures within the viral Env are associated with bystander apoptosis. Our studies show that primary Envs vary considerably in their bystander apoptosis-inducing potential, a phenomenon that correlates inversely with putative N-linked glycosylation sites and positively with virion infectivity. By use of a novel phylogenetic analysis that avoids subtype bias coupled with structural considerations, we found specific residues like Arg-476 and Asn-425 that were associated with differences in bystander apoptosis induction. A specific role of these residues was also confirmed experimentally. These data demonstrate for the first time the potential of primary R5 Envs to mediate bystander apoptosis in CD4+ T cells. Furthermore, we identify specific genetic signatures within the Env that may be associated with the bystander apoptosis-inducing phenotype. PMID:24265318

Characterization of radiation-induced Apoptosis in rodent cell lines

International Nuclear Information System (INIS)

Guo, Min; Chen, Changhu; Ling, C.C.

1997-01-01

For REC:myc(ch1), Rat1 and Rat1:myc b cells, we determined the events in the development of radiation-induced apoptosis to be in the following order: cell division followed by chromatin condensation, membrane blebbing, loss of adhesion and the uptake of vital dye. Experimental data which were obtained using 4 He ions of well defined energies and which compared the dependence of apoptosis and clonogenic survival on 4 He range strongly suggested that in our cells both apoptosis and loss of clonogenic survival resulted from radiation damage to the cell nucleus. Corroboratory evidence was that BrdU incorporation sensitized these cells to radiation-induced apoptosis. Comparing the dose response for apoptosis and the clonogenic survival curves for Rat1 and Rat1:myc b cells, we concluded that radiation-induced cell inactivation as assayed by clonogenic survival, and that a modified linear-quadratic model, proposed previously, modeled such a contribution effectively. In the same context, the selective increase in radiation-induced apoptosis. Comparing the dose response for apoptosis and the clonogenic survival curves for Rat1 and Rat1:myc b cells, we concluded that radiation-induced apoptosis contributed to the overall radiation-induced cell inactivation as assayed by clonogenic survival, and that a modified linear-quadratic model, proposed previously, modeled such a contribution effectively. In the same context, the selective increase in radiation-induced apoptosis during late S and G 2 phases reduced the relative radioresistance observed for clonogenic survival during late S and G 2 phases. 30 refs., 8 figs

Iron dysregulation combined with aging prevents sepsis-induced apoptosis.

Science.gov (United States)

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

2005-09-01

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

Shifting the balance of mitochondrial apoptosis: therapeutic perspectives

International Nuclear Information System (INIS)

Fulda, Simone

2012-01-01

Signaling via the intrinsic (mitochondrial) pathway of apoptosis represents one of the critical signal transduction cascades that control the regulation of cell death. This pathway is typically altered in human cancers, thereby providing a suitable target for therapeutic intervention. Members of the Bcl-2 family of proteins as well as cell survival signaling cascades such as the PI3K/Akt/mTOR pathway are involved in the regulation of mitochondria-mediated apoptosis. Therefore, further insights into the molecular mechanisms that form the basis for the control of mitochondria-mediated apoptosis will likely open new perspectives to bypass evasion of apoptosis and treatment resistance in human cancers.

Shifting the balance of mitochondrial apoptosis: therapeutic perspectives

Energy Technology Data Exchange (ETDEWEB)

Fulda, Simone, E-mail: simone.fulda@kgu.de [Institute for Experimental Cancer Research in Pediatrics, Goethe-University, Frankfurt (Germany)

2012-10-08

Signaling via the intrinsic (mitochondrial) pathway of apoptosis represents one of the critical signal transduction cascades that control the regulation of cell death. This pathway is typically altered in human cancers, thereby providing a suitable target for therapeutic intervention. Members of the Bcl-2 family of proteins as well as cell survival signaling cascades such as the PI3K/Akt/mTOR pathway are involved in the regulation of mitochondria-mediated apoptosis. Therefore, further insights into the molecular mechanisms that form the basis for the control of mitochondria-mediated apoptosis will likely open new perspectives to bypass evasion of apoptosis and treatment resistance in human cancers.

Shifting the balance of mitochondrial apoptosis: therapeutic perspectives

Directory of Open Access Journals (Sweden)

Simone eFulda

2012-10-01

Full Text Available Signaling via the intrinsic (mitochondrial pathway of apoptosis represents one of the critical signal transduction cascades that control the regulation of cell death. This pathway is typically altered in human cancers, thereby providing a suitable target for therapeutic intervention. Members of the Bcl-2 family of proteins as well as cell survival signaling cascades such as the PI3K/Akt/mTOR pathway are involved in the regulation of mitochondria-mediated apoptosis. Therefore, further insights into the molecular mechanisms that form the basis for the control of mitochondria-mediated apoptosis will likely open new perspectives to bypass evasion of apoptosis and treatment resistance in human cancers.

Apoptosis transcriptional mechanism of feline infectious peritonitis virus infected cells.

Science.gov (United States)

Shuid, Ahmad Naqib; Safi, Nikoo; Haghani, Amin; Mehrbod, Parvaneh; Haron, Mohd Syamsul Reza; Tan, Sheau Wei; Omar, Abdul Rahman

2015-11-01

Apoptosis has been postulated to play an important role during feline infectious peritonitis virus (FIPV) infection; however, its mechanism is not well characterized. This study is focused on apoptosis and transcriptional profiling of FIPV-infected cells following in vitro infection of CRFK cells with FIPV 79-1146 WSU. Flow cytometry was used to determine mode of cell death in first 42 h post infection (hpi). FIPV infected cells underwent early apoptosis at 9 hpi (p apoptosis at 12 hpi (p apoptosis cluster (80 down-regulated and 51 up-regulated) along with increase of apoptosis, p53, p38 MAPK, VEGF and chemokines/cytokines signaling pathways were probably involved in apoptosis process. Six of the de-regulated genes expression (RASSF1, BATF2, MAGEB16, PDCD5, TNFα and TRAF2) and TNFα protein concentration were analyzed by RT-qPCR and ELISA, respectively, at different time-points. Up-regulations of both pro-apoptotic (i.e. PDCD5) and anti-apoptotic (i.e. TRAF2) were detected from first hpi and continuing to deregulate during apoptosis process in the infected cells.

Csk regulates angiotensin II-induced podocyte apoptosis.

Science.gov (United States)

Zhang, Lu; Ren, Zhilong; Yang, Qian; Ding, Guohua

2016-07-01

Increasing data have shown that angiotensin II (Ang II) perpetuates podocyte injury and promotes progression to end-stage kidney disease. The mechanism underlying Ang II-induced podocyte apoptosis has not been established. C-terminal Src kinase (Csk) is a cytoplasmic kinase that interacts with scaffolding proteins involved in cell growth, adhesion, and polarization, and the role of Csk in regulating cellular apoptosis has gradually attracted attention. This study evaluates the role of Csk in Ang II-induced podocyte apoptosis. In vivo, Wistar rats were randomly subjected to a normal saline or Ang II infusion. In vitro, we exposed differentiated mouse podocytes to Ang II. Ang II increased Csk expression and induced podocyte apoptosis, stimulated Csk translocation and binding to Caveolin-1, and stimulated decreased Fyn pY416, increased Fyn pY529, and nephrin dephosphorylation. Csk knockdown prevented Ang II-induced podocyte apoptosis, reduced Fyn kinase inactivation, and increased the interaction between nephrin and the activated form of Fyn, accompanied by a reduced interaction between Csk and Caveolin-1. These findings indicate that Ang II induces podocyte injury via a Csk-dependent pathway.

Influence of vitamin D on cell cycle, apoptosis, and some apoptosis related molecules in systemic lupus erythematosus

Directory of Open Access Journals (Sweden)

Nafise Tabasi

2015-11-01

Full Text Available Objective(s:Genetic and environmental factors are involved in the pathogenesis of systemic lupus erythematosus (SLE. Autoreactive lymphocytes are cleared through apoptosis and any disturbance in the apoptosis or clearance of apoptotic cells may disturb tolerance and lead to autoimmunity. Vitamin D has anti-proliferative effects and controls cell cycle progression. In this study we investigated the effects of vitamin D on cell cycle and apoptosis induction in lupus patients. Materials and Methods:Isolated peripheral blood mononuclear cells (PBMCs from 25 SLE patients were cultured in the presence of 50 nM of 1,25(OH2D3; then one part of the cells were stained with FITC labeled Annexin V and PI and were analyzed for apoptosis determination. For gene expression assessment of FasL, Bcl-2 and Bax, RNA was extracted from one another part of the cells, cDNA was synthesized and gene expression analysis was performed using Real time PCR. An additional part of the cells were treated with PI and the cell cycle was analyzed using flowcytometer. Results: The mean number of early apoptotic cells in vitamin D treated cells decreased significantly (18.48±7.9% compared to untreated cells (22.02±9.4% (P=0.008. Cell cycle analysis showed a significant increase in G1 phase in vitamin D treated cells (67.33±5.2% compared to non treated ones (60.77±5.7% (P =0.02. Vitamin D up-regulated the expression levels of Bcl-2 by (18.87 fold increase, and down-regulated expression of Bax (23% and FasL (25%. Conclusion:Vitamin D has regulatory effects on cell cycle progression, apoptosis and apoptosis related molecules in lupus patients.

Effect modification by apoptosis-related gene polymorphisms on the associations of phthalate exposure with spermatozoa apoptosis and semen quality

International Nuclear Information System (INIS)

Yang, Pan; Gong, Ya-Jie; Wang, Yi-Xin; Liang, Xin-Xiu; Liu, Qing; Liu, Chong; Chen, Ying-Jun; Sun, Li; Lu, Wen-Qing

2017-01-01

Background: Human studies indicate that phthalate exposure is associated with adverse male reproductive health, and this association may be modified by genetic polymorphisms. Objectives: We investigated whether apoptosis-related gene polymorphisms modified the associations of phthalate exposure with spermatozoa apoptosis and semen quality. Methods: In this Chinese population who sought for semen examination in an infertility clinic, we measured 8 phthalate metabolites in two urine samples to assess the individual's exposure levels. Apoptosis-related gene (Fas, FasL, and caspase3) polymorphisms were performed by real-time PCR. Spermatozoa apoptosis and semen quality parameters were evaluated by Annexin V/PI assay and computer-aided semen analysis, respectively. Results: We found that Fas rs2234767, FasL rs763110, and caspase3 rs12108497 gene polymorphisms significantly modified the associations between urinary phthalate metabolites and spermatozoa apoptosis. For example, urinary monobutyl phthalate (MBP) associated with an increased percentage of Annexin V + /PI − spermatozoa of 25.11% (95% CI: 4.08%, 50.53%) were only observed among men with CT/TT genotype of FasL rs763110. In addition, we found that caspase3 rs12108497 gene polymorphisms significantly modified the associations of urinary mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) with decreased sperm concentration and sperm count (both p-values for interactions = 0.02). Conclusion: Our results provided the first evidence that apoptosis-related gene polymorphisms might contribute to the effects of phthalate exposure on male reproductive health. - Highlights: • We used two urine samples to assess the individual's phthalate exposure levels. • Fas, FasL, and caspase3 variants modified the association between phthalate exposure and spermatozoa apoptosis. • Caspase3 variants modified the association between phthalate exposure and semen quality. • Gene-environment interaction effects should be

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

Science.gov (United States)

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

2016-01-01

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

Effect modification by apoptosis-related gene polymorphisms on the associations of phthalate exposure with spermatozoa apoptosis and semen quality.

Science.gov (United States)

Yang, Pan; Gong, Ya-Jie; Wang, Yi-Xin; Liang, Xin-Xiu; Liu, Qing; Liu, Chong; Chen, Ying-Jun; Sun, Li; Lu, Wen-Qing; Zeng, Qiang

2017-12-01

Human studies indicate that phthalate exposure is associated with adverse male reproductive health, and this association may be modified by genetic polymorphisms. We investigated whether apoptosis-related gene polymorphisms modified the associations of phthalate exposure with spermatozoa apoptosis and semen quality. In this Chinese population who sought for semen examination in an infertility clinic, we measured 8 phthalate metabolites in two urine samples to assess the individual's exposure levels. Apoptosis-related gene (Fas, FasL, and caspase3) polymorphisms were performed by real-time PCR. Spermatozoa apoptosis and semen quality parameters were evaluated by Annexin V/PI assay and computer-aided semen analysis, respectively. We found that Fas rs2234767, FasL rs763110, and caspase3 rs12108497 gene polymorphisms significantly modified the associations between urinary phthalate metabolites and spermatozoa apoptosis. For example, urinary monobutyl phthalate (MBP) associated with an increased percentage of Annexin V + /PI - spermatozoa of 25.11% (95% CI: 4.08%, 50.53%) were only observed among men with CT/TT genotype of FasL rs763110. In addition, we found that caspase3 rs12108497 gene polymorphisms significantly modified the associations of urinary mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) with decreased sperm concentration and sperm count (both p-values for interactions = 0.02). Our results provided the first evidence that apoptosis-related gene polymorphisms might contribute to the effects of phthalate exposure on male reproductive health. Copyright © 2017 Elsevier Ltd. All rights reserved.

The genomic underpinnings of apoptosis in the silkworm, Bombyx mori

Science.gov (United States)

2010-01-01

Background Apoptosis is regulated in an orderly fashion by a series of genes, and has a crucial role in important physiological processes such as growth development, immunological response and so on. Recently, substantial studies have been undertaken on apoptosis in model animals including humans, fruit flies, and the nematode. However, the lack of genomic data for silkworms limits their usefulness in apoptosis studies, despite the advantages of silkworm as a representative of Lepidoptera and an effective model system. Herein we have identified apoptosis-related genes in the silkworm Bombyx mori and compared them to those from insects, mammals, and nematodes. Results From the newly assembled genome databases, a genome-wide analysis of apoptosis-related genes in Bombyx mori was performed using both nucleotide and protein Blast searches. Fifty-two apoptosis-related candidate genes were identified, including five caspase family members, two tumor necrosis factor (TNF) superfamily members, one Bcl-2 family member, four baculovirus IAP (inhibitor of apoptosis) repeat (BIR) domain family members and 1 RHG (Reaper, Hid, Grim, and Sickle; Drosophila cell death activators) family member. Moreover, we identified a new caspase family member, BmCaspase-New, two splice variants of BmDronc, and Bm3585, a mammalian TNF superfamily member homolog. Twenty-three of these apoptosis-related genes were cloned and sequenced using cDNA templates isolated from BmE-SWU1 cells. Sequence analyses revealed that these genes could have key roles in apoptosis. Conclusions Bombyx mori possesses potential apoptosis-related genes. We hypothesized that the classic intrinsic and extrinsic apoptotic pathways potentially are active in Bombyx mori. These results lay the foundation for further apoptosis-related study in Bombyx mori. PMID:21040523

Role of heat shock proteins in cell apoptosis

Directory of Open Access Journals (Sweden)

Arleta Kaźmierczuk

2010-06-01

Full Text Available Apoptosis is, apart from necrosis and autophagy, one of the possible cell death mechanisms eliminating needless, not normal or infected cells. This process ensures quantitative and qualitative cell control of organisms. Apoptosis is tightly regulated, it requires both activation of a large number of genes and energy input. Up-to-date two main apoptotic pathways have been recognized – external/receptor and internal, processed with the participation of mitochondria. Heat shock proteins HSPs, the molecules known from their chaperone activity and molecular conservatism, play essential functions in the course of apoptosis. Among that proteins family, i.e. HSP100, 90, 70, 60, 40 and small molecular (sHSP, there are agents mainly protective against programmed cell death. However, in some conditions some of these proteins may promote apoptosis. This review describes different key apoptotic proteins interacting with main members of HSP family and the consequence of these events for cell survival or apoptosis.

Apoptosis Gene Information System--AGIS.

Science.gov (United States)

Sakharkar, Kishore R; Clement, Marie V; Chow, Vincent T K; Pervaiz, Shazib

2006-05-01

Genes implicated in apoptosis have great relevance to biology, medicine and oncology. Here, we describe a unique resource, Apoptosis Gene Information System (AGIS) that provides data for over 2400 genes involved directly or indirectly, in apoptotic pathways of more than 350 different organisms. The organization of this information system is based on the principle of one-gene, one record. AGIS will be updated on a six monthly basis as new information becomes available. AGIS can be accessed at: http://www.cellfate.org/AGIS/.

Targeted induction of apoptosis for cancer therapy

NARCIS (Netherlands)

Bremer, Edwin

2006-01-01

Introduction to the thesis Programmed cell death, known as apoptosis, is an essential cellular homeostasis mechanism that ensures correct development and function of multi-cellular organisms. The pivotal importance of correct execution of apoptosis is apparent from the many human diseases with

Modern aspects of Drosophila melanogaster radiobiology. Apoptosis and aging

International Nuclear Information System (INIS)

Zajnulin, V.G.; Moskalev, A.A.; Shaposhnikov, M.V.; Taskaev, A.I.

1999-01-01

An attempt is made to explain the radioinduced change in life span of multicell organisms by deregulation of apoptosis processes. Radiation capacity to induce the apoptosis is shown in Drosophila as well. Assumption is made that radiation changes the rate of natural organism aging deregulating the control of apoptosis mechanisms [ru

Apoptosis-Dependent and Apoptosis-Independent Functions of Bim in Prostate Cancer Cells

National Research Council Canada - National Science Library

Tang, Dean; Liu, Junwei

2005-01-01

... (death, survival, proliferation/division, etc.). Our hypothesis is that, under normal, unstimulated conditions, with its apoptotic function blocked, the upregulated Bim in PCa cells plays an apoptosis-independent function...

Interplay between apoptosis and autophagy in colorectal cancer.

Science.gov (United States)

Qian, Hao-Ran; Shi, Zhao-Qi; Zhu, He-Pan; Gu, Li-Hu; Wang, Xian-Fa; Yang, Yi

2017-09-22

Autophagy and apoptosis are two pivotal mechanisms in mediating cell survival and death. Cross-talk of autophagy and apoptosis has been documented in the tumorigenesis and progression of cancer, while the interplay between the two pathways in colorectal cancer (CRC) has not yet been comprehensively summarized. In this study, we outlined the basis of apoptosis and autophagy machinery firstly, and then reviewed the recent evidence in cellular settings or animal studies regarding the interplay between them in CRC. In addition, several key factors that modulate the cross-talk between autophagy and apoptosis as well as its significance in clinical practice were discussed. Understanding of the interplay between the cell death mechanisms may benefit the translation of CRC treatment from basic research to clinical use.

Wavelength-dependent backscattering measurements for quantitative monitoring of apoptosis, Part 1: early and late spectral changes are indicative of the presence of apoptosis in cell cultures

Science.gov (United States)

Mulvey, Christine S.; Zhang, Kexiong; Liu, Wei-Han Bobby; Waxman, David J.; Bigio, Irving J.

2011-11-01

Apoptosis, a form of programmed cell death with unique morphological and biochemical features, is dysregulated in cancer and is activated by many cancer chemotherapeutic drugs. Noninvasive assays for apoptosis in cell cultures can aid in screening of new anticancer agents. We have previously demonstrated that elastic scattering spectroscopy can monitor apoptosis in cell cultures. In this report we present data on monitoring the detailed time-course of scattering changes in a Chinese hamster ovary (CHO) and PC-3 prostate cancer cells treated with staurosporine to induce apoptosis. Changes in the backscattering spectrum are detectable within 10 min, and continue to progress up to 48 h after staurosporine treatment, with the magnitude and kinetics of scattering changes dependent on inducer concentration. Similar responses were observed in CHO cells treated with several other apoptosis-inducing protocols. Early and late scattering changes were observed under conditions shown to induce apoptosis via caspase activity assay and were absent under conditions where apoptosis was not induced. Finally, blocking caspase activity and downstream apoptotic morphology changes prevented late scattering changes. These observations demonstrate that early and late changes in wavelength-dependent backscattering correlate with the presence of apoptosis in cell cultures and that the late changes are specific to apoptosis.

Apoptosis in fish: environmental factors and programmed cell death.

Science.gov (United States)

AnvariFar, Hossein; Amirkolaie, Abdolsamad Keramat; Miandare, Hamed Kolangi; Ouraji, Hossein; Jalali, M Ali; Üçüncü, Sema İşisağ

2017-06-01

Apoptosis, a form of programmed cell death, is a critical component in maintaining homeostasis and growth in all tissues and plays a significant role in immunity and cytotoxicity. In contrast to necrosis or traumatic cell death, apoptosis is a well-controlled and vital process characterized mainly by cytoplasmic shrinkage, chromatin condensation, DNA fragmentation, membrane blebbing and apoptotic bodies. Our understanding of apoptosis is partly based on observations in invertebrates but mainly in mammals. Despite the great advantages of fish models in studying vertebrate development and diseases and the tremendous interest observed in recent years, reports on apoptosis in fish are still limited. Although apoptotic machinery is well conserved between aquatic and terrestrial organisms throughout the history of evolution, some differences exist in key components of apoptotic pathways. Core parts of apoptotic machinery in fish are virtually expressed as equivalent to the mammalian models. Some differences are, however, evident, such as the extrinsic and intrinsic pathways of apoptosis including lack of a C-terminal region in the Fas-associated protein with a death domain in fish. Aquatic species inhabit a complex and highly fluctuating environment, making these species good examples to reveal features of apoptosis that may not be easily investigated in mammals. Therefore, in order to gain a wider view on programmed cell death in fish, interactions between the main environmental factors, chemicals and apoptosis are discussed in this review. It is indicated that apoptosis can be induced in fish by exposure to environmental stressors during different stages of the fish life cycle.

Heat Shock Protein 70 Neutralizes Apoptosis-Inducing Factor

Directory of Open Access Journals (Sweden)

Guido Kroemer

2001-01-01

Full Text Available Programmed cell death (apoptosis is the physiological process responsible for the demise of superfluous, aged, damaged, mutated, and ectopic cells. Its normal function is essential both for embryonic development and for maintenance of adult tissue homeostasis. Deficient apoptosis participates in cancerogenesis, whereas excessive apoptosis leads to unwarranted cell loss accounting for disparate diseases including neurodegeneration and AIDS. One critical step in the process of apoptosis consists in the permeabilization of mitochondrial membranes, leading to the release of proteins which normally are secluded behind the outer mitochondrial membrane[1]. For example, cytochrome c, which is normally confined to the mitochondrial intermembrane space, is liberated from mitochondria and interacts with a cytosolic protein, Apaf-1, causing its oligomerization and constitution of the so-called apoptosome, a protein complex which activates a specific class of cysteine proteases, the caspases[2]. Another example concerns the so-called apoptosis-inducing factor (AIF, another mitochondrial intermembrane protein which can translocate to the nucleus where it induces chromatin condensation and DNA fragmentation[3].

Lysosomal ceramide generated by acid sphingomyelinase triggers cytosolic cathepsin B-mediated degradation of X-linked inhibitor of apoptosis protein in natural killer/T lymphoma cell apoptosis.

Science.gov (United States)

Taniguchi, M; Ogiso, H; Takeuchi, T; Kitatani, K; Umehara, H; Okazaki, T

2015-04-09

We previously reported that IL-2 deprivation induced acid sphingomyelinase-mediated (ASM-mediated) ceramide elevation and apoptosis in an NK/T lymphoma cell line KHYG-1. However, the molecular mechanism of ASM-ceramide-mediated apoptosis during IL-2 deprivation is poorly understood. Here, we showed that IL-2 deprivation induces caspase-dependent apoptosis characterized by phosphatidylserine externalization, caspase-8, -9, and -3 cleavage, and degradation of X-linked inhibitor of apoptosis protein (XIAP). IL-2 re-supplementation rescued apoptosis via inhibition of XIAP degradation without affecting caspase cleavage. However, IL-2 deprivation induced ceramide elevation via ASM in lysosomes and activated lysosomal cathepsin B (CTSB) but not cathepsin D. A CTSB inhibitor CA-074 Me and knockdown of CTSB inhibited ceramide-mediated XIAP degradation and apoptosis. Inhibition of ceramide accumulation in lysosomes using an ASM inhibitor, desipramine, decreased cytosolic activation of CTSB by inhibiting its transfer into cytosol from the lysosome. Knockdown of ASM also inhibited XIAP degradation and apoptosis. Furthermore, cell permeable N-acetyl sphingosine (C2-ceramide), which increases mainly endogenous d18:1/16:0 and d18:1/24:1 ceramide-like IL-2 deprivation, induced caspase-dependent apoptosis with XIAP degradation through CTSB. These findings suggest that lysosomal ceramide produced by ASM mediates XIAP degradation by activation of cytosolic CTSB and caspase-dependent apoptosis. The ASM-ceramide-CTSB signaling axis is a novel pathway of ceramide-mediated apoptosis in IL-2-deprived NK/T lymphoma cells.

Functional role of apoptosis in oral diseases: An update.

Science.gov (United States)

Misra, Akansha; Rai, Shalu; Misra, Deepankar

2016-01-01

Cell death appears to be a basic biological phenomenon which is maintained by the human body. The term apoptosis, also known as programmed cell death, is characterized by several unique morphological and biochemical features. Apoptosis and its different forms are essential for tissue homeostasis. Alteration in molecular mechanisms involved in apoptotic signaling contributes to a vast range of oral diseases. An understanding of the regulation of apoptosis has led to the development of many therapeutic approaches and better management of oral diseases. The review updates us the correlation between apoptosis in normal oral tissues and oral diseases.

N-acetylphytosphingosine enhances the radiosensitivity of tumor cells by increasing apoptosis

International Nuclear Information System (INIS)

Han, Y.; Kim, Y.; Yun, Y.; Jeon, S.; Kim, K.; Song, J.; Hong, S.H.; Park, C.

2005-01-01

Ceramides are well-known second messengers which mediate apoptosis, proliferation, differentiation in mammalian cells, but the physiological roles of phytosphingosines are poorly understood. We hypothesized that one of the phytosphingosine derivatives, N-acetylphytosphingosine (NAPS) can induce apoptosis in human leukemia Jurkat cell line and increase apoptosis in irradiated MDA-MB-231 cells. We first examined the effect of NAPS on apoptosis of Jurkat cells. NAPS had a more rapid and stronger apoptotic effect than C 2 -ceramide in Jurkat cells and significant increase of apoptosis was observed at 3 h after treatment. In contrast, the apoptosis induced by C2-ceramide was observed only after 16 h of treatment. NAPS induced apoptosis was mediated by caspase 3 and 8 activation and inhibited by z-VAD-fmk. Ceramide plays a pivotal role in radiation induced apoptosis. We postulated that exogenous treatment of NAPS sensitizes tumor cells to ionizing radiation, since NAPS might be used as a more effective alternative to C2-ceramide. As expected, NAPS decreased clonogenic survival of irradiated MDA-MB-231 cells dose dependently, and apoptosis of irradiated cells in the presence of NAPS was increased through the caspase activation. Taken together, NAPS is an effective apoptosis-inducing agent, which can be readily synthesized from yeast sources, and is a potent alternative to ceramide for the further study of ceramide associated signaling and the development of radiosensitizing agent. (orig.)

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

Science.gov (United States)

Ahmed, Kanwal; Tabuchi, Yoshiaki; Kondo, Takashi

2015-11-01

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

Effect of low dose radiation on apoptosis in mouse spleen

International Nuclear Information System (INIS)

Chen Dong; Liu Jiamei; Chen Aijun; Liu Shuzheng

1999-01-01

Objective: To study the effect of whole body irradiation (WBI) with different doses of X-ray on apoptosis in mouse spleen. Methods: Time course changes and dose-effect relationship of apoptosis in mouse spleen induced by WBI were observed with transmission electron microscopy (TEM) qualitatively and TUNEL method semi-quantitatively. Results: Many typical apoptotic lymphocytes were found by TEM in mouse spleen after WBI with 2 Gy. No marked alterations of ultrastructure were found following WBI with 0.075 Gy. It was observed by TUNEL that the apoptosis of splenocytes increased after high dose radiation and decreased following low dose radiation (LDR). The dose-effect relationship of radiation-induced apoptosis showed a J-shaped curve. Conclusion: The effect of different doses of ionizing radiation on apoptosis in mouse spleen was distinct. And the decrease of apoptosis after LDR is considered a manifestation of radiation hormesis

Involvement of apoptosis in host-parasite interactions in the zebra mussel.

Directory of Open Access Journals (Sweden)

Laëtitia Minguez

Full Text Available The question of whether cell death by apoptosis plays a biological function during infection is key to understanding host-parasite interactions. We investigated the involvement of apoptosis in several host-parasite systems, using zebra mussels Dreissena polymorpha as test organisms and their micro- and macroparasites. As a stress response associated with parasitism, heat shock proteins (Hsp can be induced. In this protein family, Hsp70 are known to be apoptosis inhibitors. Mussels were diagnosed for their respective infections by standard histological methods; apoptosis was detected using the TUNEL methods on paraffin sections and Hsp70 by immunohistochemistry on cryosections. Circulating hemocytes were the main cells observed in apoptosis whereas infected tissues displayed no or few apoptotic cells. Parasitism by intracellular bacteria Rickettsiales-like and the trematode Bucephalus polymorphus were associated with the inhibition of apoptosis whereas ciliates Ophryoglena spp. or the trematode Phyllodistomum folium did not involve significant differences in apoptosis. Even if some parasites were able to modulate apoptosis in zebra mussels, we did not see evidence of any involvement of Hsp70 on this mechanism.

Involvement of Apoptosis in Host-Parasite Interactions in the Zebra Mussel

Science.gov (United States)

Minguez, Laëtitia; Brulé, Nelly; Sohm, Bénédicte; Devin, Simon; Giambérini, Laure

2013-01-01

The question of whether cell death by apoptosis plays a biological function during infection is key to understanding host-parasite interactions. We investigated the involvement of apoptosis in several host-parasite systems, using zebra mussels Dreissena polymorpha as test organisms and their micro- and macroparasites. As a stress response associated with parasitism, heat shock proteins (Hsp) can be induced. In this protein family, Hsp70 are known to be apoptosis inhibitors. Mussels were diagnosed for their respective infections by standard histological methods; apoptosis was detected using the TUNEL methods on paraffin sections and Hsp70 by immunohistochemistry on cryosections. Circulating hemocytes were the main cells observed in apoptosis whereas infected tissues displayed no or few apoptotic cells. Parasitism by intracellular bacteria Rickettsiales-like and the trematode Bucephalus polymorphus were associated with the inhibition of apoptosis whereas ciliates Ophryoglena spp. or the trematode Phyllodistomum folium did not involve significant differences in apoptosis. Even if some parasites were able to modulate apoptosis in zebra mussels, we did not see evidence of any involvement of Hsp70 on this mechanism. PMID:23785455

Apoptosis (programmed cell death) as an indicator of xenobiotic toxicity

International Nuclear Information System (INIS)

Bond, G.P.

1989-01-01

Xenobiotics alter the frequency and pattern of apoptosis (programmed cell death). Preliminary studies identified the mouse liver, with normally low levels of apoptosis, as a preferable test system to the chicken embryo limb, with normally high levels of apoptosis. The major purposes of these investigations, using the apoptogen and necrogen 1,1-dichloroethylene (DCE), were to determine if increases in apoptosis, (1) could be quantified as a direct result of treatment, (2) were dose- and time-dependent, (3) were independent of necrosis, (4) were associated with mitosis in the control of cell numbers and (5) were limited to specific areas of the liver. To these ends, food-deprived female, CF-1 mice were administered DCE ip under varying experimental conditions. Increased apoptosis occurred in a dose- and time-dependent manner after treatment with 12.5, 40, and 125 mg/kg for 0.5, 1, 2, 4 and 8 hr. Peak effects were observed at 4 hr. Apoptosis occurred only in the midzonal/pericentral areas of the liver. At 12.5 mg/kg, there were no effects on biochemical (alanine transaminase) and morphological indices of necrosis, establishing apoptosis as a separate phenomenon from necrosis. Increased 3 H-thymidine incorporation (DNA synthesis), mitosis and the percentage of octaploid hepatocytes occurred from 24-48 hr after treatment with the apoptotic but non-necrotic dose of 40 mg/kg. Apoptosis only occurred in the midzonal/pericentral areas of the liver after multiple doses with DCE, indicating the zonal selectivity of the response. In conclusion, apoptosis, a normally occurring homeostatic process associated with mitosis in the control of cell numbers, is affected by selected xenobiotics in a dose-dependent manner. Xenobiotic-induced apoptosis in the liver occurs at low doses of xenobiotics which cause no other effects on tissue structure or function

Apoptosis in HEp-2 cells infected with Ureaplasma diversum.

Science.gov (United States)

Amorim, Aline Teixeira; Marques, Lucas Miranda; Santos, Angelita Maria Oliveira Gusmão; Martins, Hellen Braga; Barbosa, Maysa Santos; Rezende, Izadora Souza; Andrade, Ewerton Ferraz; Campos, Guilherme Barreto; Lobão, Tássia Neves; Cortez, Beatriz Araujo; Monezi, Telma Alvez; Machado-Santelli, Glaucia Maria; Timenetsky, Jorge

2014-09-04

Bacterial pathogens have many strategies for infecting and persisting in host cells. Adhesion, invasion and intracellular life are important features in the biology of mollicutes. The intracellular location of Ureaplasma diversum may trigger disturbances in the host cell. This includes activation or inhibition of pro and anti-apoptotic factors, which facilitate the development of host damage. The aim of the present study was to associate U. diversum infection in HEp-2 cells and apoptosis induction. Cells were infected for 72hs with four U. diversum clinical isolates and an ATCC strain. The U. diversum invasion was analyzed by Confocal Laser Scanning Microscopy and gentamicin invasion assay. The apoptosis was evaluated using pro-apoptotic and anti-apoptotic gene expression, and FITC Annexin V/Dead Cell Apoptosis Kit. The number of internalized ureaplasma in HEp-2 cells increased significantly throughout the infection. The flow cytometry analysis with fluorochromes to detect membrane depolarization and gene expression for caspase 2, 3 and 9 increased in infected cells after 24 hours. However, after 72 hours a considerable decrease of apoptotic cells was observed. The data suggests that apoptosis may be initially induced by some isolates in association with HEp-2 cells, but over time, there was no evidence of apoptosis in the presence of ureaplasma and HEp-2 cells. The initial increase and then decrease in apoptosis could be related to bacterial pathogen-associated molecular pattern (PAMPS). Moreover, the isolates of U. diversum presented differences in the studied parameters for apoptosis. It was also observed that the amount of microorganisms was not proportional to the induction of apoptosis in HEp-2 cells.

"Falling leaves": a survey of the history of apoptosis.

Science.gov (United States)

Formigli, L; Conti, A; Lippi, D

2004-04-01

Cell death has long been defined using morphological criteria. A first important concept, "necrosis", was early identified by Areteo from Cappadocia and by Galen. The term apoptosis was introduced by Kerr in 1972 to indicate a particular form of death in which cells commit suicide by chopping themselves into membrane-bounded apoptotic bodies. Apoptosis is distinguished from necrosis, or accidental cell death, which is characterized by nuclear autolysis and cell disintegration. The aim of this study was an evaluation of the concepts of apoptosis and necrosis, starting from the first definition of cell death by Rudolph Virchow in 1859. In recent years substantial progress has been made in the understanding of apoptotic and necrotic cell death. In particular, cell death researchers have evolved a paradigm change, from one in which apoptosis and necrosis were considered distinct forms of cell demise, to one in which the 2 cell deaths share common features, as an integral part of a same cell death process. Since pure apoptosis and necrosis are only extremes in a continuum spectrum of aponecrotic response, a mixture of features associated with both apoptosis and necrosis represents the more typical tissue and cell response to damaging stimuli.

Apoptosis in vascular cells induced by cold atmospheric plasma treatment

NARCIS (Netherlands)

Sladek, R.E.J.; Stoffels - Adamowicz, E.

2006-01-01

Apoptosis is a natural mechanism of cellular self-destruction. It can be triggered by moderate, yet irreversible damage. Apoptosis plays a major role in tissue renewal. Artificial apoptosis induction will become a novel therapy that meets all requirements for tissue-saving surgery. Diseased tissues

Apoptosis induced by high- and low-LET radiations

International Nuclear Information System (INIS)

Hendry, J.H.; Potten, C.S.; Merritt, A.

1995-01-01

Cell death after irradiation occurs by apoptosis in certain cell populations in tissues. The phenomenon also occurs after high linear energy transfer (LET) irradiation, and the relative biological effectiveness (RBE) is 3 to 4 (with respect to low-LET radiation and apoptosis in intestinal crypts) for neutrons with energies of 14 MeV and up to 600 MeV. It is thought that p53 plays a role in the phenomenon, as radiation-induced apoptosis is not observed in p53-null animals. (orig.)

X-linked inhibitor of apoptosis regulates T cell effector function

DEFF Research Database (Denmark)

Zehntner, Simone P; Bourbonnière, Lyne; Moore, Craig S

2007-01-01

To understand how the balance between pro- and anti-apoptotic signals influences effector function in the immune system, we studied the X-linked inhibitor of apoptosis (XIAP), an endogenous regulator of cellular apoptosis. Real-time PCR showed increased XIAP expression in blood of mice with exper......To understand how the balance between pro- and anti-apoptotic signals influences effector function in the immune system, we studied the X-linked inhibitor of apoptosis (XIAP), an endogenous regulator of cellular apoptosis. Real-time PCR showed increased XIAP expression in blood of mice...... dramatically reduced within the CNS. Flow cytometry showed an 88-93% reduction in T cells. The proportion of TUNEL(+) apoptotic CD4(+) T cells in the CNS was increased from Neurons...... and oligodendrocytes were not affected; neither did apoptosis increase in liver, where XIAP knockdown also occurred. ASO-XIAP increased susceptibility of T cells to activation-induced apoptosis in vitro. Our results identify XIAP as a critical controller of apoptotic susceptibility of effector T cell function...

The characteristics and mechanism of apoptosis induced by internal irradiation

International Nuclear Information System (INIS)

Hong Chengjiao; Zhang Junning; Zhu Shoupeng

2001-01-01

Apoptosis in tumor cells induced by radionuclides is likely the most effective way to cure cancer. In order to explore the possibility in clinic application, the characteristics and mechanism of apoptosis induced by internal irradiation were investigated. The apoptosis and expressions of bcl-2mRNA, bcl-2 and bax of K 562 cells following internal exposure with different accumulated absorbed doses of strontium-89 were studied. 6 h after irradiation, the characteristics of apoptosis and necrosis appeared in K 562 cells. The apoptosis and necrosis enhanced with the prolongation of internally contaminated time at 6 h, 9 h, 12 h, 24 h and 48 h. The expressions of bcl-2mRNA decreased at 12 h, most remarkably at 24 h. The expressions of bcl-2 decreased after irradiation whereas bax had no obvious changes. The results suggest that the apoptosis induced by internal exposure may be regulated by lower expressions of bcl-2mRNA and bcl-2, lower bcl-2/bax value

Bile acids: regulation of apoptosis by ursodeoxycholic acid.

Science.gov (United States)

Amaral, Joana D; Viana, Ricardo J S; Ramalho, Rita M; Steer, Clifford J; Rodrigues, Cecília M P

2009-09-01

Bile acids are a group of molecular species of acidic steroids with peculiar physical-chemical and biological characteristics. At high concentrations they become toxic to mammalian cells, and their presence is pertinent in the pathogenesis of several liver diseases and colon cancer. Bile acid cytoxicity has been related to membrane damage, but also to nondetergent effects, such as oxidative stress and apoptosis. Strikingly, hydrophilic ursodeoxycholic acid (UDCA), and its taurine-conjugated form (TUDCA), show profound cytoprotective properties. Indeed, these molecules have been described as potent inhibitors of classic pathways of apoptosis, although their precise mode of action remains to be clarified. UDCA, originally used for cholesterol gallstone dissolution, is currently considered the first choice therapy for several forms of cholestatic syndromes. However, the beneficial effects of both UDCA and TUDCA have been tested in other experimental pathological conditions with deregulated levels of apoptosis, including neurological disorders, such as Alzheimer's, Parkinson's, and Huntington's diseases. Here, we review the role of bile acids in modulating the apoptosis process, emphasizing the anti-apoptotic effects of UDCA and TUDCA, as well as their potential use as novel and alternate therapeutic agents for the treatment of apoptosis-related diseases.

IMMUNOLOGICAL MECHANISMS OF APOPTOSIS IN PLACENTAL DEVELOPMENT

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D. I. Sokolov

2008-01-01

Full Text Available Abstract. In present review, the data are considered that concern a role of immunological mechanisms controlling the events of apoptosis at different stages of development of placenta. Intensity of apoptotic process in human placenta is progressively increasing in the course of pregnancy, until delivery act. The processes of apoptosis induction and its prevention in placental cells are inseparably linked to development of placenta and formation of vascular system, as controlled by trophoblast cells, as well as by maternal fetal immune cells. T-lymphocytes, natural killer cells, NKT-cells and macrophages that perform surveillance over the processes of angiogenesis and apoptosis in placental tissue, thus providing its normal development and functioning.

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.

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.

indicators of apoptosis in Duchenne Muscular Dystrophy Patients

African Journals Online (AJOL)

and at the molecular level versus 20 age and socioeconomic matching healthy boys. ... to the tumor necrosis factor superfam- ily and induces apoptosis ... tory cell induced apoptosis in blood of ..... Brain 1997; 120 (Pt 6): 929-38. Butterfield TA ...

Evasion of Apoptosis as a Cellular Stress Response in Cancer

Directory of Open Access Journals (Sweden)

Simone Fulda

2010-01-01

Full Text Available One of the hallmarks of human cancers is the intrinsic or acquired resistance to apoptosis. Evasion of apoptosis can be part of a cellular stress response to ensure the cell's survival upon exposure to stressful stimuli. Apoptosis resistance may contribute to carcinogenesis, tumor progression, and also treatment resistance, since most current anticancer therapies including chemotherapy as well as radio- and immunotherapies primarily act by activating cell death pathways including apoptosis in cancer cells. Hence, a better understanding of the molecular mechanisms regarding how cellular stress stimuli trigger antiapoptotic mechanisms and how this contributes to tumor resistance to apoptotic cell death is expected to provide the basis for a rational approach to overcome apoptosis resistance mechanisms in cancers.

Physiology and pathophysiology of apoptosis in epithelial cells of the liver, pancreas, and intestine.

Science.gov (United States)

Jones, B A; Gores, G J

1997-12-01

Cell death of gastrointestinal epithelial cells occurs by a process referred to as apoptosis. In this review, we succinctly define apoptosis and summarize the role of apoptosis in the physiology and pathophysiology of epithelial cells in the liver, pancreas, and small and large intestine. The physiological mediators regulating apoptosis in gastrointestinal epithelial cells, when known, are discussed. Selected pathophysiological consequences of excessive apoptosis and inhibition of apoptosis are used to illustrate the significance of apoptosis in disease processes. These examples demonstrate that excessive apoptosis may result in epithelial cell atrophy, injury, and dysfunction, whereas inhibition of apoptosis results in hyperplasia and promotes malignant transformation. The specific cellular mechanisms responsible for dysregulation of epithelial cell apoptosis during pathophysiological disturbances are emphasized. Potential future areas of physiological research regarding apoptosis in gastrointestinal epithelia are highlighted when appropriate.

Lysosomal ceramide generated by acid sphingomyelinase triggers cytosolic cathepsin B-mediated degradation of X-linked inhibitor of apoptosis protein in natural killer/T lymphoma cell apoptosis

OpenAIRE

Taniguchi, M; Ogiso, H; Takeuchi, T; Kitatani, K; Umehara, H; Okazaki, T

2015-01-01

We previously reported that IL-2 deprivation induced acid sphingomyelinase-mediated (ASM-mediated) ceramide elevation and apoptosis in an NK/T lymphoma cell line KHYG-1. However, the molecular mechanism of ASM?ceramide-mediated apoptosis during IL-2 deprivation is poorly understood. Here, we showed that IL-2 deprivation induces caspase-dependent apoptosis characterized by phosphatidylserine externalization, caspase-8, -9, and -3 cleavage, and degradation of X-linked inhibitor of apoptosis pro...

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

Science.gov (United States)

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

2015-11-01

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

Evaluation of apoptosis and apoptosis proteins as possible markers of radiation at doses 0.1-2 Gy, in comparison to the micronucleus assay in three cell lines

International Nuclear Information System (INIS)

Jaworska, A.; Angelis, P. de

1997-01-01

In recent years the interest in apoptosis as possible indicator of radiation damage has increased. Studies have been done to examine the induction of apoptosis after ionizing radiation using morphological criteria, characteristic DNA damage pattern(ladders), early DNA damage using flow cytometry and/or expression of the proteins involved in apoptosis. But the picture which emerges from these investigations is unclear. Some researchers suggest that apoptosis studies can be used as potential assays of biological dosimetry, others doubt if apoptosis can be used as a marker of irradiation at all. Most studies have been done using relatively high doses of radiation. In this study we focus on apoptosis induction after relatively small doses (0,1-2 Gy). We detected apoptosis with the in situ terminal deoxynucleotidyl transferase assay by flow cytometry, and measured the expression of proteins that regulate apoptosis (Bcl-2, Bax, P53) with Western blotting. As comparison we used the cytokinesis-block micronucleus assay as a reference. The studies were carried out in three lymphoid cell lines: the mouse lymphoma L5178Y resistant and sensitive cell lines widely used in radiobiological studies, and the human pre-B cell leukemia Reh cells. Our results indicate that we can not consider the examined parameters of apoptosis as markers of radiation in these cell lines. (author)

Apoptosis of acinar cells in pancreas allograft rejection

NARCIS (Netherlands)

Boonstra, J. G.; Wever, P. C.; Laterveer, J. C.; Bruijn, J. A.; van der Woude, F. J.; ten Berge, I. J.; Daha, M. R.

1997-01-01

BACKGROUND: Recently it has been recognized that apoptosis of target cells may occur during liver and kidney allograft rejection and is probably induced by infiltrating cells. Pancreas rejection is also characterized by a cellular infiltrate, however, the occurrence of apoptosis has not been

Accelerated apoptosis of neutrophils in familial Mediterranean fever

DEFF Research Database (Denmark)

Manukyan, Gayane; Aminov, Rustam; Hakobyan, Gagik

2015-01-01

The causative mutations for familial Mediterranean fever (FMF) are located in the MEFV gene, which encodes pyrin. Pyrin modulates the susceptibility to apoptosis via its PYD domain, but how the mutated versions of pyrin affect apoptotic processes are poorly understood. Spontaneous and induced rates...... of systemic neutrophil apoptosis as well as the levels of proteins involved in apoptosis were investigated ex vivo in patients with FMF using flow cytometry and RT-qPCR. The freshly collected neutrophils from the patients in FMF remission displayed a significantly larger number of cells spontaneously entering...... apoptosis compared to control (6.27 ± 2.14 vs. 1.69 ± 0.18%). This elevated ratio was retained after 24 h incubation of neutrophils in the growth medium (32.4 ± 7.41 vs. 7.65 ± 1.32%). Correspondingly, the mRNA level for caspase-3 was also significantly increased under these conditions. In response...

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.

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.

Bisphenol A induces spermatocyte apoptosis in rare minnow Gobiocypris rarus

International Nuclear Information System (INIS)

Zhang, Yingying; Cheng, Mengqian; Wu, Lang; Zhang, Guo; Wang, Zaizhao

2016-01-01

Highlights: • Adult male G. rarus were exposed to 225 μg/L BPA for 7, 21 and 63 days. • BPA could induce spermatocyte apoptosis in rare minnow testis. • The mitochondrial apoptotic pathway participated in the germ cell apoptosis. • The spermatocyte apoptosis was likely initiated by BPA induced meiosis arrest. - Abstract: Bisphenol A (BPA) is an endocrine disruptor, and could induce germ cells apoptosis in the testis of mammals. But whether it could affect fish in the same mechanism has not’ been studied till now. In the present study, to investigate the influence of BPA on testis germ cells in fish, adult male rare minnow Gobiocypris rarus were exposed to 225 μg L"−"1 (0.99 μM) BPA for 1, 3 and 9 weeks. Through TdT-mediated dUTP nick end labeling (TUNEL) and transmission electron microscope (TEM) analysis, we found that the amount of apoptotic spermatocytes significantly increased in a time dependent manner following BPA exposure. Western Blot results showed that the ratio of Bcl2/Bax, the important apoptosis regulators in intrinsic mitochondrial apoptotic pathway, was significantly decreased. qPCR showed that mRNA expression of several genes in mitochondrial apoptotic pathway including bcl2, bax, casp9, cytc and mcl1b were significantly changed following BPA exposure. In addition, mRNA expression of meiosis regulation genes (kpna7 and wee2), and genes involved in both apoptosis and meiosis (birc5, ccna1, and gsa1a) were also affected by BPA. Taken together, the present study demonstrated that BPA could induce spermatocytes apoptosis in rare minnow testis, and the apoptosis was probably under regulation of intrinsic mitochondrial apoptotic pathway. Moreover, the spermatocyte apoptosis was likely initiated by BPA induced meiosis arrest.

Bisphenol A induces spermatocyte apoptosis in rare minnow Gobiocypris rarus

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yingying; Cheng, Mengqian; Wu, Lang; Zhang, Guo; Wang, Zaizhao, E-mail: zzwang@nwsuaf.edu.cn

2016-10-15

Highlights: • Adult male G. rarus were exposed to 225 μg/L BPA for 7, 21 and 63 days. • BPA could induce spermatocyte apoptosis in rare minnow testis. • The mitochondrial apoptotic pathway participated in the germ cell apoptosis. • The spermatocyte apoptosis was likely initiated by BPA induced meiosis arrest. - Abstract: Bisphenol A (BPA) is an endocrine disruptor, and could induce germ cells apoptosis in the testis of mammals. But whether it could affect fish in the same mechanism has not’ been studied till now. In the present study, to investigate the influence of BPA on testis germ cells in fish, adult male rare minnow Gobiocypris rarus were exposed to 225 μg L{sup −1} (0.99 μM) BPA for 1, 3 and 9 weeks. Through TdT-mediated dUTP nick end labeling (TUNEL) and transmission electron microscope (TEM) analysis, we found that the amount of apoptotic spermatocytes significantly increased in a time dependent manner following BPA exposure. Western Blot results showed that the ratio of Bcl2/Bax, the important apoptosis regulators in intrinsic mitochondrial apoptotic pathway, was significantly decreased. qPCR showed that mRNA expression of several genes in mitochondrial apoptotic pathway including bcl2, bax, casp9, cytc and mcl1b were significantly changed following BPA exposure. In addition, mRNA expression of meiosis regulation genes (kpna7 and wee2), and genes involved in both apoptosis and meiosis (birc5, ccna1, and gsa1a) were also affected by BPA. Taken together, the present study demonstrated that BPA could induce spermatocytes apoptosis in rare minnow testis, and the apoptosis was probably under regulation of intrinsic mitochondrial apoptotic pathway. Moreover, the spermatocyte apoptosis was likely initiated by BPA induced meiosis arrest.

Effects of low dose radiation on tumor apoptosis, cell cycle progression and changes of apoptosis-related protein bcl-2 in tumor-bearing mice

International Nuclear Information System (INIS)

Yu Hongsheng; Fei Conghe; Shen Fangzhen; Liang Jun

2003-01-01

Objective: To study the effect of low dose radiation (LDR) on tumor apoptosis, cell cycle progression and changes of apoptosis-related protein bcl-2 in tumor-bearing mice. Methods: Kunming stain male mice were implanted with S180 sarcoma cells in the left inguen subcutaneously as an in situ experimental animal model. Seven days after implantation, the mice were given 75 mGy whole-body γ-irradiation. At 24 and 48 h after irradiation, all mice were sacrificed to measure the tumor volume, and tumor cell apoptosis, cell cycle progression were analyzed by flow cytometry. The expression of apoptosis-related protein bcl-2 and the apoptotic rate of tumor cells were observed by immunohistochemistry and electron microscopy. Results: Tumor growth was significantly slowed down after LDR (P 1 phase and the expression of bcl-2 protein decreased at 24 h. Apoptotic rate of tumor cells increased significantly at 48 h after LDR. Conclusion: LDR could cause a G 1 -phase arrest and increase the apoptosis of tumor cells through the low level of apoptosis-related protein bcl-2 in the tumor-bearing mice. The organized immune function and anti-tumor ability are markedly increased after LDR. The study provides practical evidence of clinical application to cancer treatment

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...

Apoptosis study of the macrophage via near-field scanning optical microscope

International Nuclear Information System (INIS)

Wang, D-C; Chen, K-Y; Chen, G-Y; Chen, S-H; Wun, S-J

2008-01-01

The cell apoptosis phenomenon was studied by traditional optical microscope with much lower resolution and also observed by Atomic Force Microscope (AFM) with nano-resolution recently. They both detect the cell apoptosis through the change of cell topography. In this study, the cell apoptosis was investigated via Near-Field Scanning Optical Microscope (NSOM). The cell topography, with nano-scaled resolution, and its optical characteristics were observed by NSOM at the same measurement scanning. The macrophage was chosen as the cell investigated. To understand the cell apoptosis process is the goal set for the research. The apoptosis process was related to the variations of the optical characteristics of the cell

Advanced oxidation protein products induce chondrocyte apoptosis via receptor for advanced glycation end products-mediated, redox-dependent intrinsic apoptosis pathway.

Science.gov (United States)

Wu, Qian; Zhong, Zhao-Ming; Zhu, Si-Yuan; Liao, Cong-Rui; Pan, Ying; Zeng, Ji-Huan; Zheng, Shuai; Ding, Ruo-Ting; Lin, Qing-Song; Ye, Qing; Ye, Wen-Bin; Li, Wei; Chen, Jian-Ting

2016-01-01

Pro-inflammatory cytokine-induced chondrocyte apoptosis is a primary cause of cartilage destruction in the progression of rheumatoid arthritis (RA). Advanced oxidation protein products (AOPPs), a novel pro-inflammatory mediator, have been confirmed to accumulate in patients with RA. However, the effect of AOPPs accumulation on chondrocyte apoptosis and the associated cellular mechanisms remains unclear. The present study demonstrated that the plasma formation of AOPPs was enhanced in RA rats compared with normal. Then, chondrocyte were treated with AOPPs-modified rat serum albumin (AOPPs-RSA) in vitro. Exposure of chondrocyte to AOPPs activated nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and increased expression of NADPH oxidase subunits, which was mediated by receptor for advanced glycation end products (RAGE), but not scavenger receptor CD36. Moreover, AOPPs challenge triggered NADPH oxidase-dependent ROS generation which induced mitochondrial dysfunction and endoplasmic reticulum stress resulted in activation of caspase family that eventually lead to apoptosis. Lastly, blockade of RAGE, instead of CD36, largely attenuated these signals. Our study demonstrated first time that AOPPs induce chondrocyte apoptosis via RAGE-mediated and redox-dependent intrinsic apoptosis pathway in vitro. These data implicates that AOPPs may represent a novel pathogenic factor that contributes to RA progression. Targeting AOPPs-triggered cellular mechanisms might emerge as a promising therapeutic option for patients with RA.

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

Science.gov (United States)

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.

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

Lipid Metabolism, Apoptosis and Cancer Therapy

Directory of Open Access Journals (Sweden)

Chunfa Huang

2015-01-01

Full Text Available Lipid metabolism is regulated by multiple signaling pathways, and generates a variety of bioactive lipid molecules. These bioactive lipid molecules known as signaling molecules, such as fatty acid, eicosanoids, diacylglycerol, phosphatidic acid, lysophophatidic acid, ceramide, sphingosine, sphingosine-1-phosphate, phosphatidylinositol-3 phosphate, and cholesterol, are involved in the activation or regulation of different signaling pathways. Lipid metabolism participates in the regulation of many cellular processes such as cell growth, proliferation, differentiation, survival, apoptosis, inflammation, motility, membrane homeostasis, chemotherapy response, and drug resistance. Bioactive lipid molecules promote apoptosis via the intrinsic pathway by modulating mitochondrial membrane permeability and activating different enzymes including caspases. In this review, we discuss recent data in the fields of lipid metabolism, lipid-mediated apoptosis, and cancer therapy. In conclusion, understanding the underlying molecular mechanism of lipid metabolism and the function of different lipid molecules could provide the basis for cancer cell death rationale, discover novel and potential targets, and develop new anticancer drugs for cancer therapy.

Thymocyte apoptosis in response to low-dose radiation

International Nuclear Information System (INIS)

Shu-Zheng, Liu; Ying-Chun, Zhang; Ying, Mu; Xu, Su; Jian-Xiang, Liu

1996-01-01

Thymocyte apoptosis was assessed by counting apoptotic bodies with flow cytometry (FCM) and measuring DNA fragmentation with fluorescence spectrophotometry (FSP). J-shaped dose-response curves were obtained after both whole-body irradiation (WBI) of mice and in vitro irradiation of EL4 cells with doses ranging from 0.025 to 4 Gy X-rays. There was a significant reduction of apoptosis rate to below control level with doses within 0.2 Gy, and a dose-dependent increase in apoptosis with doses above 0.5 Gy. When thymocytes were cultured 24 h after WBI with 75 mGy X-rays in complete RPMI 1640 medium, a reduction in apoptosis was observed in the course of incubation for 72 h, and the presence of Con A in the medium accentuated this reduction in a dose- and time-dependent manner. The implications of these observations and the possible molecular mechanisms for future studies are proposed

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

Apoptosis in spermatogonia irradiated P53 null mice

International Nuclear Information System (INIS)

Streit-Bianchi, M.; Hendry, J.H.; Roberts, S.A.; Morris, J.D.; Durgaryan, A.A.

2007-01-01

Complete text of publication follows. The exposure of germ cells to ionizing radiations is of concern both from high-dose therapeutic exposures and from low doses causing deleterious trans-generational mutations. P53 protein plays an important role in cellular damage and is expressed in the testis normally during meiosis, its expression being localised to the preleptotene and early/mid pachytene spermatocytes. P53 null mice, heterozygotes possessing a 129 Sv/C57BL6 genetic background and B6D2F1 mice have been irradiated to 1 and 2 Gy single doses. Fractionated exposures of 1+1 Gy at 4 hours interval were also carried out. Apoptosis induction, spermatogonia and spermatocytes survival were assessed by microscope analysis of histological samples at 4 to 96 hours after irradiation in time-course experiments. The same end-points were also assessed at 72 and 96 hours after irradiation to single doses in the region between 20cGy to 2Gy. A dose dependent level of p53 expression was observed at 4 hours after irradiation to 1 and 2 Gy which returned to normal level by 24 hours. Our data support a two process mode of apoptosis with a first wave around 12 hours followed by a second wave at 2-3 days. The first wave apoptosis is substantially reduced in p53 null mice whereas the second wave is reduced in B6D2F1 mice. The initial increase in apoptosis was delayed in some stages of the of germ cells development which were identified by the spermatids shape. Clear correlation exists between apoptosis and survival assessed in stage XI-XII Tubules 72 hours after irradiation. The data are in agreement with other data in literature indicating that irradiated spermatogonia die through apoptosis. The lack of apoptosis observed in p53 null mice results in a very high survival rate of daughter cells assessed later. Theses spermatocytes and the following progenitor cells are likely to carry mutations as most will not die in the smaller second wave of apoptosis observed 3 days after

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

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.

In Vivo Imaging of Apoptosis in Oncology: An Update

Directory of Open Access Journals (Sweden)

Christel Vangestel

2011-09-01

Full Text Available In this review, data on noninvasive imaging of apoptosis in oncology are reviewed. Imaging data available are presented in order of occurrence in time of enzymatic and morphologic events occurring during apoptosis. Available studies suggest that various radiopharmaceutical probes bear great potential for apoptosis imaging by means of positron emission tomography and single-photon emission computed tomography (SPECT. However, for several of these probes, thorough toxicologic studies are required before they can be applied in clinical studies. Both preclinical and clinical studies support the notion that 99mTc-hydrazinonicoti-namide-annexin A5 and SPECT allow for noninvasive, repetitive, quantitative apoptosis imaging and for assessing tumor response as early as 24 hours following treatment instigation. Bioluminescence imaging and near-infrared fluorescence imaging have shown great potential in small-animal imaging, but their usefulness for in vivo imaging in humans is limited to structures superficially located in the human body. Although preclinical tumor-based data using high-frequency-ultrasonography (US are promising, whether or not US will become a routinely clinically useful tool in the assessment of therapy response in oncology remains to be proven. The potential of magnetic resonance imaging (MRI and magnetic resonance spectroscopy (MRS for imaging late apoptotic processes is currently unclear. Neither 31P MRS nor 1H MRS signals seems to be a unique identifier for apoptosis. Although MRI-measured apparent diffusion coefficients are altered in response to therapies that induce apoptosis, they are also altered by nonapoptotic cell death, including necrosis and mitotic catastrophe. In the future, rapid progress in the field of apoptosis imaging in oncology is expected.

Correlation of lung surface area to apoptosis and proliferation in human emphysema.

Science.gov (United States)

Imai, K; Mercer, B A; Schulman, L L; Sonett, J R; D'Armiento, J M

2005-02-01

Pulmonary emphysema is associated with alterations in matrix proteins and protease activity. These alterations may be linked to programmed cell death by apoptosis, potentially influencing lung architecture and lung function. To evaluate apoptosis in emphysema, lung tissue was analysed from 10 emphysema patients and six individuals without emphysema (normal). Morphological analysis revealed alveolar cells in emphysematous lungs with convoluted nuclei characteristic of apoptosis. DNA fragmentation was detected using terminal deoxynucleotide transferase-mediated dUTP nick-end labelling (TUNEL) and gel electrophoresis. TUNEL revealed higher apoptosis in emphysematous than normal lungs. Markers of apoptosis, including active caspase-3, proteolytic fragment of poly (ADP-ribose) polymerase, Bax and Bad, were detected in emphysematous lungs. Linear regression showed that apoptosis was inversely correlated with surface area. Emphysematous lungs demonstrated lower surface areas and increased cell proliferation. There was no correlation between apoptosis and proliferation, suggesting that, although both events increase during emphysema, they are not in equilibrium, potentially contributing to reduced lung surface area. In summary, cell-based mechanisms associated with emphysematous parenchymal damage include increased apoptosis and cell proliferation. Apoptosis correlated with airspace enlargement, supporting epidemiological evidence of the progressive nature of emphysema. These data extend the understanding of cell dynamics and structural changes within the lung during emphysema pathogenesis.

Cellular response after irradiation: Cell cycle control and apoptosis

International Nuclear Information System (INIS)

Siles, E.; Valenzuela, M.T.; Nunez, M.I.; Guerrero, R.; Villalobos, M.; Ruiz de Almodovar, J.M.

1997-01-01

The importance of apoptotic death was assessed in a set of experiments, involving eight human tumour cell lines (breast cancer, bladder carcinoma, medulloblastoma). Various aspects of the quantitative study of apoptosis and methods based on the detection of DNA fragmentation (in situ tailing and comet assay) are described and discussed. Data obtained support the hypothesis that apoptosis is not crucial for cellular radiosensitivity and that the relationship between p53 functionality or clonogenic survival and apoptosis may bee cell type specific. (author)

Podocyte hypertrophy precedes apoptosis under experimental diabetic conditions.

Science.gov (United States)

Lee, Sun Ha; Moon, Sung Jin; Paeng, Jisun; Kang, Hye-Young; Nam, Bo Young; Kim, Seonghun; Kim, Chan Ho; Lee, Mi Jung; Oh, Hyung Jung; Park, Jung Tak; Han, Seung Hyeok; Yoo, Tae-Hyun; Kang, Shin-Wook

2015-08-01

Podocyte hypertrophy and apoptosis are two hallmarks of diabetic glomeruli, but the sequence in which these processes occur remains a matter of debate. Here we investigated the effects of inhibiting hypertrophy on apoptosis, and vice versa, in both podocytes and glomeruli, under diabetic conditions. Hypertrophy and apoptosis were inhibited using an epidermal growth factor receptor inhibitor (PKI 166) and a pan-caspase inhibitor (zAsp-DCB), respectively. We observed significant increases in the protein expression of p27, p21, phospho-eukaryotic elongation factor 4E-binding protein 1, and phospho-p70 S6 ribosomal protein kinase, in both cultured podocytes exposed to high-glucose (HG) medium, and streptozotocin-induced diabetes mellitus (DM) rat glomeruli. These increases were significantly inhibited by PKI 166, but not by zAsp-DCB. In addition, the amount of protein per cell, the relative cell size, and the glomerular volume were all significantly increased under diabetic conditions, and these changes were also blocked by treatment with PKI 166, but not zAsp-DCB. Increased protein expression of cleaved caspase-3 and cleaved poly (ADP-ribose) polymerase, together with increased Bax/Bcl-2 ratios, were also observed in HG-stimulated podocytes and DM glomeruli. Treatment with either zAsp-DCB or PKI 166 resulted in a significant attenuation of these effects. Both PKI 166 and zAsp-DCB also inhibited the increase in number of apoptotic cells, as assessed by Hoechst 33342 staining and TUNEL assay. Under diabetic conditions, inhibition of podocyte hypertrophy results in attenuated apoptosis, whereas blocking apoptosis has no effect on podocyte hypertrophy, suggesting that podocyte hypertrophy precedes apoptosis.

Mitochondrial pathway of apoptosis and related proteins in placenta ...

African Journals Online (AJOL)

eclampsia (PE).This study aimed at evaluating the mitochondrial pathway of apoptosis in placenta of pregnant women with pre-eclampsia and correlate it with severity and pregnancy outcome . Apoptosis was assessed by measuring DNA ...

Tumor Response to Radiotherapy Regulated by Endothelial Cell Apoptosis

Science.gov (United States)

Garcia-Barros, Monica; Paris, Francois; Cordon-Cardo, Carlos; Lyden, David; Rafii, Shahin; Haimovitz-Friedman, Adriana; Fuks, Zvi; Kolesnick, Richard

2003-05-01

About 50% of cancer patients receive radiation therapy. Here we investigated the hypothesis that tumor response to radiation is determined not only by tumor cell phenotype but also by microvascular sensitivity. MCA/129 fibrosarcomas and B16F1 melanomas grown in apoptosis-resistant acid sphingomyelinase (asmase)-deficient or Bax-deficient mice displayed markedly reduced baseline microvascular endothelial apoptosis and grew 200 to 400% faster than tumors on wild-type microvasculature. Thus, endothelial apoptosis is a homeostatic factor regulating angiogenesis-dependent tumor growth. Moreover, these tumors exhibited reduced endothelial apoptosis upon irradiation and, unlike tumors in wild-type mice, they were resistant to single-dose radiation up to 20 grays (Gy). These studies indicate that microvascular damage regulates tumor cell response to radiation at the clinically relevant dose range.

The correlation between spontaneous and radiation-induced apoptosis in T3B bladder cancer (histological grade G3), and the precedence between the two kinds of apoptosis for predicting clinical prognosis

International Nuclear Information System (INIS)

Harada, Satoshi; Sato, Ryuichi; Nakamura, Ryuji; Oikawa, Hiroshi; Oikawa, Hirobumi; Ohgi, Shie; Tamakawa, Yoshiharu; Yanagisawa, Toru

2000-01-01

Purpose: The correlation between the frequency of spontaneous and radiation-induced apoptosis, and the precedence between those for predicting prognosis were studied at clinical level. Methods and Materials: Twenty-one patients (mean age, 65.8 years; 16 men and 5 women) with bladder cancer (transitional cell carcinoma Grade 3, T3bN0M0, Stage IIIb) underwent intraoperative radiotherapy: single 30-Gy 12-MV electron beam irradiation to bladder, followed by total cystectomy 6 h after irradiation. The specimens of pretreatment and irradiated bladder cancer were assayed for apoptosis, using TUNEL staining with counter staining of hematoxylin. The apoptotic index (AI) was calculated by dividing the number of apoptotic cells by the total number of cells and multiplying by 100. The Pearson's linear fitting was used to test the correlation between spontaneous and radiation-induced apoptosis. The Kaplan-Meier product-limit estimation was used for overall survival (OS) and freedom from recurrence (FFR). The precedence between spontaneous and radiation-induced apoptosis for predicting the clinical prognosis was estimated using the proportional hazard regression. Results: The mean AI of spontaneous and radiation-induced apoptosis was 1.18 ± 0.16 and 2.63 ± 0.45, respectively, which was significantly different. There was strong correlation between spontaneous and radiation-induced apoptosis (r 2 = 0.864, adjusted r 2 = 0.857). Radiation-induced apoptosis was estimated by equitation: y (radiation-induced apoptosis) = 2.67 x (spontaneous apoptosis) -0.52. However, the proportional hazard regression test indicated that only spontaneous apoptosis was significant for predicting OS and FFR (vertical bar t vertical bar > 0.2), but radiation-induced apoptosis was not. Conclusion: Estimating AI in radiation-induced apoptosis from AI in spontaneous apoptosis is possible. However, spontaneous apoptosis is more accurate in predicting clinical prognosis

Resistance to apoptosis should not be taken as a hallmark of cancer.

Science.gov (United States)

Wang, Rui-An; Li, Zeng-Shan; Yan, Qing-Guo; Bian, Xiu-Wu; Ding, Yan-Qing; Du, Xiang; Sun, Bao-Cun; Sun, Yun-Tian; Zhang, Xiang-Hong

2014-02-01

In the research community, resistance to apoptosis is often considered a hallmark of cancer. However, pathologists who diagnose cancer via microscope often see the opposite. Indeed, increased apoptosis and mitosis are usually observed simultaneously in cancerous lesions. Studies have shown that increased apoptosis is associated with cancer aggressiveness and poor clinical outcome. Furthermore, overexpression of Bcl-2, an antiapoptotic protein, is linked with better survival of cancer patients. Conversely, Bax, CD95, Caspase-3, and other apoptosis-inducing proteins have been found to promote carcinogenesis. This notion of the role of apoptosis in cancer is not new; cancer cells were found to be short-lived 88 years ago. Given these observations, resistance to apoptosis should not be considered a hallmark of cancer.

Differential Apoptosis in Mucosal and Dermal Wound Healing

Science.gov (United States)

Johnson, Ariel; Francis, Marybeth; DiPietro, Luisa Ann

2014-01-01

Objectives: Dermal and mucosal healing are mechanistically similar. However, scarring and closure rates are dramatically improved in mucosal healing, possibly due to differences in apoptosis. Apoptosis, nature's preprogrammed form of cell death, occurs via two major pathways, extrinsic and intrinsic, which intersect at caspase3 (Casp3) cleavage and activation. The purpose of this experiment was to identify the predominant pathways of apoptosis in mucosal and dermal wound healing. Approach: Wounds (1 mm biopsy punch) were made in the dorsal skin (n=3) or tongue (n=3) of female Balb/C mice aged 6 weeks. Wounds were harvested at 6 h, 24 h, day 3 (D3), D5, D7, and D10. RNA was isolated and analyzed using real time reverse transcriptase–polymerase chain reaction. Expression levels for genes in the intrinsic and extrinsic apoptotic pathways were compared in dermal and mucosal wounds. Results: Compared to mucosal healing, dermal wounds exhibited significantly higher expression of Casp3 (at D5; phealing compared to skin. Conclusion: Expression patterns of key regulators of apoptosis in wound healing indicate that apoptosis occurs predominantly through the intrinsic pathway in the healing mucosa, but predominantly through the extrinsic pathway in the healing skin. The identification of differences in the apoptotic pathways in skin and mucosal wounds may allow the development of therapeutics to improve skin healing. PMID:25493209

[Mechanisms of signaling associated with reactive nitrogen and oxygen in apoptosis].

Science.gov (United States)

Piłat, Justyna; Ługowski, Mateusz; Saczko, Jolanta; Choromańska, Anna; Chwiłkowska, Agnieszka; Banaś, Teresa; Kulbacka, Julita

2016-05-01

The knowledge of apoptotic mechanisms is essential in many biologic aspects related to both normal and neoplastic cells. Cell death by apoptosis is a very desirable way to eliminate unwanted cells: prevents release of the cellular content, which, in contrast to necrosis, provides no activation of inflammatory reactions. Apoptosis is a multistep process in where an extremely important role is played by caspases. Functions of caspases and their modifications are fundamental to understanding the signaling pathways responsible for regulation of apoptosis. These enzymes belong to a family of cysteine proteases that have the potential to destroy the enzymatic and structural proteins, and in the final stages of apoptosis, to lead to the disintegration of the cell. Apoptosis can be modulated by certain signaling pathway. © 2016 MEDPRESS.

5-Fluorouracil-induced apoptosis in cultured oral cancer cells.

Science.gov (United States)

Tong, D; Poot, M; Hu, D; Oda, D

2000-03-01

Chemotherapy is commonly used to treat advanced oral squamous cell carcinoma (SCC) and is known to kill cancer cells through apoptosis. Our hypothesis states that 5-fluorouracil (5FU) also kills cultured oral epithelial cells through programmed cell death or apoptosis. Cultured oral cancer cells were exposed to an optimum dose of 20 mg/ml of 5FU. Cells were analyzed for changes in cell cycle distribution and induction of cell death including apoptosis. Normal control, human papilloma virus-immortalized (PP), ATCC SCC cell line (CA1) and two primary oral SCC cell lines (CA3 and -4) were studied. Inhibition of apoptosis by a pan-caspase inhibitor was used. SYTO 11 flow cytometry showed increased apoptosis in all 5FU-treated cell cultures compared to untreated controls. The results show biological variation in apoptotic response. CA1 had the lowest apoptotic rate of the cancer cell lines at 1.5%. Next lowest was CA3, followed by CA4 and PP. In addition, alteration in the G1 and S phase fractions were found. Untreated CA1 showed 28% G1, 53% S compared to 43% G1, and 40% S of treated. We investigated the pathway of apoptosis using the pan-caspase inhibitor IDN-1529 by methylthiazolyl diphenyl tetrazolium bromide (MTT) colorimetric analysis. Results showed mild inhibition of cell death when cells were incubated with 50 microM IDN-1529 for 24 h. This suggests a probable caspase-dependent apoptotic pathway. In conclusion, our data suggest that 5FU induces oral cancer cell death through apoptosis and that biological variation exists between normal and cancer cells and between different types of cancer cells themselves. Our data indicate that cultures of a useful in vitro model for chemosensitivity assays are possible. Our results also suggest a caspase-dependent pathway for chemocytotoxicity in oral SCC.

Detection of radiation-induced apoptosis using the comet assay

International Nuclear Information System (INIS)

Wada, Seiichi; Kobayashi, Yasuhiko; Funayama, Tomoo; Yamamoto, Kazuo; Khoa, Tran Van; Natsuhori, Masahiro; Ito, Nobuhiko

2003-01-01

The electrophoresis pattern of apoptotic cells detected by the comet assay has a characteristic small head and spread tail. This image has been referred to as an apoptotic comet, but it has not been previously proven to be apoptotic cells by any direct method. In order to identify this image obtained by the comet assay as corresponding to an apoptotic cell, the frequency of appearance of apoptosis was examined using CHO-K1 and L5178Y cells which were exposed to gamma irradiation. As a method for detecting apoptosis, the terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) assay was used. When the frequency of appearance of apoptotic cells following gamma irradiation was observed over a period of time, there was a significant increase in appearance of apoptosis when using the TUNEL assay. However, there was only a slight increase when using the comet assay. In order to verify the low frequency of appearance of apoptosis when using the comet assay, we attempted to use the TUNEL assay to satin the apoptotic comets detected in the comet assay. The apoptotic comets were TUNEL positive and the normal comets were TUNEL negative. This indicates that the apoptotic comets were formed from DNA fragments with 3'-hydroxy ends that are generated as cells undergo apoptosis. Therefore, it was understood that the characteristic pattern of apoptotic comets detected by the comet assay corresponds to cells undergoing apoptosis. (author)

A novel method for detection of apoptosis

International Nuclear Information System (INIS)

Zagariya, Alexander M.

2012-01-01

There are two different Angiotensin II (ANG II) peptides in nature: Human type (ANG II) and Bovine type (ANG II*). These eight amino acid peptides differ only at position 5 where Valine is replaced by Isoleucine in the Bovine type. They are present in all species studied so far. These amino acids are different by only one atom of carbon. This difference is so small, that it will allow any of ANG II, Bovine or Human antibodies to interact with all species and create a universal method for apoptosis detection. ANG II concentrations are found at substantially higher levels in apoptotic, compared to non-apoptotic, tissues. ANG II accumulation can lead to DNA damage, mutations, carcinogenesis and cell death. We demonstrate that Bovine antiserum can be used for universal detection of apoptosis. In 2010, the worldwide market for apoptosis detection reached the $20 billion mark and significantly increases each year. Most commercially available methods are related to Annexin V and TUNNEL. Our new method based on ANG II is more widely known to physicians and scientists compared to previously used methods. Our approach offers a novel alternative for assessing apoptosis activity with enhanced sensitivity, at a lower cost and ease of use.

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

Suppression of ICE and Apoptosis in Mammary Epithelial Cells by Extracellular Matrix

Energy Technology Data Exchange (ETDEWEB)

Boudreau, Nancy; Sympson, C. J.; Werb, Zena; Bissell, Mina J.

1994-12-01

Apoptosis (programmed cell death) plays a major role in development and tissue regeneration. Basement membrane extracellular matrix (ECM), but not fibronectin or collagen, was shown to suppress apoptosis of mammary epithelial cells in tissue culture and in vivo. Apoptosis was induced by antibodies to beta 1 integrins or by overexpression of stromelysin-1, which degrades ECM. Expression of interleukin-1 beta converting enzyme (ICE) correlated with the loss of ECM, and inhibitors of ICE activity prevented apoptosis. These results suggest that ECM regulates apoptosis in mammary epithelial cells through an integrin-dependent negative regulation of ICE expression.

Thymocyte apoptosis induced by p53-dependent and independent pathways

International Nuclear Information System (INIS)

Clarke, A.R.; Purdie, C.A.; Harrison, D.J.; Morris, R.G.; Bird, C.C.; Hooper, M.L.; Wyllie, A.H.

1993-01-01

The authors studied the dependence of apoptosis on p53 expression in cells from the thymus cortex. Short-term thymocyte cultures were prepared from mice constitutively heterozygous or homozygous for a deletion in the p53 gene introduced into the germ line after gene targeting. Wild-type thymocytes readily undergo apoptosis after treatment with ionizing radiation, the glucocorticoid methylprednisolone, or etoposide (an inhibitor of topoisomerase II), or after Ca 2+ -dependent activation by phorbol ester and a calcium ionophore. In contrast, homozygous null p53 thymocytes are resistant to induction of apoptosis by radiation or etoposide, but retain normal sensitivity to glucocorticoid and calcium. The time-dependent apoptosis that occurs in untreated cultures is unaffected by p53 status. Cells heterozygous for p53 deletion are partially resistant to radiation and etoposide. Results show that p53 exerts a significant and dose-dependent effect in the initiation of apoptosis, but only when it is induced by agents that cause DNA-strand breakage. (Author)

Keratocyte apoptosis and corneal antioxidant enzyme activities after refractive corneal surgery.

Science.gov (United States)

Bilgihan, K; Bilgihan, A; Adiguzel, U; Sezer, C; Yis, O; Akyol, G; Hasanreisoglu, B

2002-01-01

Refractive corneal surgery induces keratocyte apoptosis and generates reactive oxygen radicals (ROS) in the cornea. The purpose of the present study is to evaluate the correlation between keratocyte apoptosis and corneal antioxidant enzyme activities after different refractive surgical procedures in rabbits. Rabbits were divided into six groups. All groups were compared with the control group (Group 1), after epithelial scraping (Group 2), epithelial scrape and photorefractive keratectomy (PRK) (traditional PRK: Group 3), transepithelial PRK (Group 4), creation of a corneal flap with microkeratome (Group 5) and laser-assisted in situ keratomileusis (LASIK, Group 6). Terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick-end labelling assay (to detect DNA fragmentation in situ) and light microscopy were used to detect apoptosis in rabbit eyes. Glutathione peroxidase (Gpx) and superoxide dismutase (SOD) activities of the corneal tissues were measured with spectrophotometric methods. Corneal Gpx and SOD activities decreased significantly in all groups when compared with the control group (P<0.05) and groups 2, 3 and 6 showed a significantly higher amount of keratocyte apoptosis (P<0.05). Not only a negative correlation was observed between corneal SOD activity and keratocyte apoptosis (cc: -0.3648) but Gpx activity also showed negative correlation with keratocyte apoptosis (cc: -0.3587). The present study illustrates the negative correlation between keratocyte apoptosis and corneal antioxidant enzyme activities. This finding suggests that ROS may be partly responsible for keratocyte apoptosis after refractive surgery.

Anti-apoptotic signaling and failure of apoptosis in the ischemic rat hippocampus

DEFF Research Database (Denmark)

Müller, Georg Johannes; Lassmann, Hans; Johansen, Flemming Fryd

2007-01-01

Several anti-apoptotic proteins are induced in CA1 neurons after transient forebrain ischemia (TFI), but fail to protect the majority of these cells from demise. Correlating cell death morphologies (apoptosis-like and necrosis-like death) with immunohistochemistry (IHC), we investigated whether...... anti-apoptosis contributes to survival, compromises apoptosis effector functions and/or delays death in CA1 neurons 1-7 days after TFI. As surrogate markers for bioenergetic failure, the IHC of respiratory chain complex (RCC) subunits was investigated. Dentate granule cell (DGC) apoptosis following...... colchicine injection severed as a reference for classical apoptosis. Heat shock protein 70 (Hsp70), neuronal apoptosis inhibitory protein (NAIP) and manganese superoxide dismutase (MnSOD) were upregulated in the majority of intact CA1 neurons paralleling the occurrence of CA1 neuronal death (days 3...

Apoptosis in Drosophila: which role for mitochondria?

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Clavier, Amandine; Rincheval-Arnold, Aurore; Colin, Jessie; Mignotte, Bernard; Guénal, Isabelle

2016-03-01

It is now well established that the mitochondrion is a central regulator of mammalian cell apoptosis. However, the importance of this organelle in non-mammalian apoptosis has long been regarded as minor, mainly because of the absence of a crucial role for cytochrome c in caspase activation. Recent results indicate that the control of caspase activation and cell death in Drosophila occurs at the mitochondrial level. Numerous proteins, including RHG proteins and proteins of the Bcl-2 family that are key regulators of Drosophila apoptosis, constitutively or transiently localize in mitochondria. These proteins participate in the cell death process at different levels such as degradation of Diap1, a Drosophila IAP, production of mitochondrial reactive oxygen species or stimulation of the mitochondrial fission machinery. Here, we review these mitochondrial events that might have their counterpart in human.

Colorectal cancer: can nutrients modulate NF-kappaB and apoptosis?

Science.gov (United States)

Ravasco, Paula; Aranha, Márcia M; Borralho, Pedro M; Moreira da Silva, Isabel B; Correia, Luís; Fernandes, Afonso; Rodrigues, Cecília M P; Camilo, Maria

2010-02-01

NF-kappaB may promote carcinogenesis by altering cell cycle, inflammatory responses and apoptosis-related gene expression, though cell mechanisms relating diet and colorectal cancer (CRC) remain unveiled in humans. This study in patients with CRC aimed to explore potential interactions between the dietary pattern, nutrient intake, expression of NF-kappaB, apoptosis and tumour histological aggressiveness. Usual diet was assessed by diet history; nutrient composition was determined by DIETPLAN software. Histologically classified patient tissue samples (adenoma, adenocarcinoma and normal surrounding mucosa) were obtained via biopsies during colonoscopy (n=16) or surgery (n=8). NF-kappaB expression was determined by immunohistochemistry and apoptosis by TUNEL assay. NF-kappaB expression and apoptosis were higher in tumours (p<0.01), greater along with histological aggressiveness (p<0.01). Highest intake terciles of animal protein, refined carbohydrates, saturated fat, n-6 fatty acids and alcohol were associated with higher NF-kappaB, apoptosis and histological aggressiveness (p<0.01); the opposite tissue characteristics were associated with highest intake terciles of n-3 fatty acids, fibre, vitamin E, flavonoids, isoflavones, beta-carotene and selenium (p<0.002). Additionally, higher n-6:n-3 fatty acids ratio (median 26:1) was associated with higher NF-kappaB (p<0.006) and apoptosis (p<0.01), and more aggressive histology (p<0.01). Conversely, lower n-6:n-3 fatty acids ratio (median 6:1) was associated with lower NF-kappaB (p<0.002) and apoptosis (p<0.002), and less aggressive histology (p<0.002). NF-kappaB expression and apoptosis increased from adenoma to poorly differentiated adenocarcinoma. This degenerative transition, recognized as key in carcinogenesis, appear to have been influenced by a diet promoting a pro-inflammatory milieu that can trigger NF-kappaB. Copyright 2009 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

CDB-4124 does not cause apoptosis in cultured fibroid cells.

Science.gov (United States)

Roeder, Hilary; Jayes, Friederike; Feng, Liping; Leppert, Phyllis C

2011-09-01

Selective progesterone receptor modulators (SPRMs), such as asoprisnil (J867) and ulipristal (CDB-2914), have been shown to reduce fibroid volume in vivo and to induce apoptosis in vitro. CDB-4124 (telapristone), a SPRM with different side groups, also reduced fibroid volume in vivo, and we hypothesized that this SPRM would also cause apoptosis in cultured fibroid cells. Immortalized, progesterone receptor-positive fibroid cells, known to be capable of apoptosis, were grown to 80% confluence in serum-containing media. Cells were then treated for 48 hours in serum-free media with 0, 10, 100, or 1000 nmol/L CDB-4124. Actinomycin-D and staurosporine were used as positive controls to induce apoptosis. Apoptosis was quantified using a TUNEL-fluorescein kit. Images were captured with a widefield-fluorescence microscope and analyzed using MetaMorph image analysis software. To validate results, Western blots of total cell lysates were probed for cleaved caspase-3 (c-CASP3). Experiments were repeated 3 times using independent cell batches. Analysis of 19 712 nuclei indicated 14.8% ± 10.9% (mean ± SEM), 8.4% ± 4.6%, 8.2% ± 4.7%, and 9.3% ± 6.3% apoptosis in 0, 10, 100, and 1000 nmol/L CDB-4124-treated cells, respectively. There was no evidence of elevated c-CASP3 over vehicle control after treatment with CDB-4124. CDB-4124 did not significantly induce apoptosis in cultured fibroid cells under the conditions described suggesting apoptosis may not be the main pathway responsible for CDB-4124-induced fibroid shrinkage. Variations in SPRM biological effects may be due to differences in fibroid source cells, binding kinetics, or extracellular matrix characteristics, and can be exploited in further investigations of the mechanisms of action of SPRMs in fibroid biology.

Dying a thousand death. Radionuclide imaging of apoptosis

International Nuclear Information System (INIS)

Blankenberg, F.; Ohtsuki, K.; Strauss, H.W.

1999-01-01

Programmed cell death, apoptosis, in an inducible, organized, energy requiring form of demise that results in the disappearance of a cell without the induction of an inflammatory response. Apoptotic cell death is strikingly different than necrotic death, which is disorderly, does not require energy and results in local inflammation, usually secondary to sudden release of intercellular contents. Apoptosis is induced when cells undergo severe injury to their nucleus, as occurs following exposure to gamma or X-radiation, or mitochondria, as as occurs in variety of viral illnesses. Apoptosis can also be induced by externals signals, such as interaction of 'fas' ligand with 'fas' receptors. Once the cell is committed to apoptosis, the caspase enzyme cascade is activate. An early effect of caspase activation is the rapid expression of phosphatidylserine on the external leaflet of the cell membrane. Membrane bound phosphatidylserine expression serves as a signal to surrounding cells, identifying the expressing cell as undergoing apoptosis. A deficiency or an excess of programmed cell death is an integral component of autoimmune disorders, transplant rejection and cancer. A technique to image programmed cell death would be used to assist in the development of drugs, designed to treat these diseases, and to monitor the effectiveness of therapy The sudden expression of phosphatidylserine on the cell membrane is target that could be used for this purpose. A 35 kD physiologic protein, Annexin V lipocortin, binds with nanomolar affinity to membrane bound phosphatidylserine. Annexin V has been radiolabeled with Technetium-99m by direct coupling to free sulfhydryl groups, and through the hydrazinonicatinamide and N2S2 linking agents. The biodistribution of the agents labeled with each of the methods is slightly different. In all cases the radiopharmaceutical binds to cell undergoing apoptosis 'in vitro', and permits imaging of the process in experimental animals

Recombinant Vaccinia Viruses Coding Transgenes of Apoptosis-Inducing Proteins Enhance Apoptosis But Not Immunogenicity of Infected Tumor Cells

Science.gov (United States)

Tkachenko, Anastasiya; Richter, Vladimir

2017-01-01

Genetic modifications of the oncolytic vaccinia virus (VV) improve selective tumor cell infection and death, as well as activation of antitumor immunity. We have engineered a double recombinant VV, coding human GM-CSF, and apoptosis-inducing protein apoptin (VV-GMCSF-Apo) for comparing with the earlier constructed double recombinant VV-GMCSF-Lact, coding another apoptosis-inducing protein, lactaptin, which activated different cell death pathways than apoptin. We showed that both these recombinant VVs more considerably activated a set of critical apoptosis markers in infected cells than the recombinant VV coding GM-CSF alone (VV-GMCSF-dGF): these were phosphatidylserine externalization, caspase-3 and caspase-7 activation, DNA fragmentation, and upregulation of proapoptotic protein BAX. However, only VV-GMCSF-Lact efficiently decreased the mitochondrial membrane potential of infected cancer cells. Investigating immunogenic cell death markers in cancer cells infected with recombinant VVs, we demonstrated that all tested recombinant VVs were efficient in calreticulin and HSP70 externalization, decrease of cellular HMGB1, and ATP secretion. The comparison of antitumor activity against advanced MDA-MB-231 tumor revealed that both recombinants VV-GMCSF-Lact and VV-GMCSF-Apo efficiently delay tumor growth. Our results demonstrate that the composition of GM-CSF and apoptosis-inducing proteins in the VV genome is very efficient tool for specific killing of cancer cells and for activation of antitumor immunity. PMID:28951871

Involvement of Prohibitin Upregulation in Abrin-Triggered Apoptosis

Directory of Open Access Journals (Sweden)

Yu-Huei Liu

2012-01-01

Full Text Available Abrin (ABR, a protein purified from the seeds of Abrus precatorius, induces apoptosis in various types of cancer cells. However, the detailed mechanism remains largely uncharacterized. By using a cDNA microarray platform, we determined that prohibitin (PHB, a tumor suppressor protein, is significantly upregulated in ABR-triggered apoptosis. ABR-induced upregulation of PHB is mediated by the stress-activated protein kinase/c-Jun NH2-terminal kinase (SAPK/JNK pathway, as demonstrated by chemical inhibitors. In addition, ABR significantly induced the expression of Bax as well as the activation of caspase-3 and poly(ADP-ribose polymerase (PARP in Jurkat T cells, whereas the reduction of PHB by specific RNA interference delayed ABR-triggered apoptosis through the proapoptotic genes examined. Moreover, our results also indicated that nuclear translocation of the PHB-p53 complex may play a role in the transcription of Bax. Collectively, our data show that PHB plays a role in ABR-induced apoptosis, which may be helpful for the development of diagnostic or therapeutic agents.

Advance of apoptosis imaging with radiolabeled annexin V in tumor research

International Nuclear Information System (INIS)

Huang Daijuan

2003-01-01

One of the most important reasons that cause tumor is decrease or complete absence of apoptosis of tumor cells. Conversely successful anti-tumor therapy is correlated with the introduction of apoptosis into tumor cells. Radiolabeled annexin V is used to image in vivo the phosphatidylserine (PS) that explode on the outer surface of cell membrane after apoptosis so that apoptosis can be detected on the early stage. This imaging method can be introduced into the research of tumor in order to help direct the choose of tumor therapy, inspect the effect and evaluate the prognosis

In vivo imaging of apoptosis in oncology : an update

NARCIS (Netherlands)

Vangestel, Christel; Peeters, Marc; Mees, Gilles; Oltenfreiter, Ruth; Boersma, Hendrikus H; Elsinga, Philippus; Reutelingsperger, Chris; Van Damme, Nancy; De Spiegeleer, Bart; Van de Wiele, Christophe

2011-01-01

In this review, data on noninvasive imaging of apoptosis in oncology are reviewed. Imaging data available are presented in order of occurrence in time of enzymatic and morphologic events occurring during apoptosis. Available studies suggest that various radiopharmaceutical probes bear great

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

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.

Carbon ion beam triggers both caspase-dependent and caspase-independent pathway of apoptosis in HeLa and status of PARP-1 controls intensity of apoptosis.

Science.gov (United States)

Ghorai, Atanu; Sarma, Asitikantha; Bhattacharyya, Nitai P; Ghosh, Utpal

2015-04-01

High linear energy transfer (LET) carbon ion beam (CIB) is becoming very promising tool for various cancer treatments and is more efficient than conventional low LET gamma or X-rays to kill malignant or radio-resistant cells, although detailed mechanism of cell death is still unknown. Poly (ADP-ribose) polymerase-1 (PARP-1) is a key player in DNA repair and its inhibitors are well-known as radio-sensitizer for low LET radiation. The objective of our study was to find mechanism(s) of induction of apoptosis by CIB and role of PARP-1 in CIB-induced apoptosis. We observed overall higher apoptosis in PARP-1 knocked down HeLa cells (HsiI) compared with negative control H-vector cells after irradiation with CIB (0-4 Gy). CIB activated both intrinsic and extrinsic pathways of apoptosis via caspase-9 and caspase-8 activation respectively, followed by caspase-3 activation, apoptotic body, nucleosomal ladder formation and sub-G1 accumulation. Apoptosis inducing factor translocation into nucleus in H-vector but not in HsiI cells after CIB irradiation contributed caspase-independent apoptosis. Higher p53 expression was observed in HsiI cells compared with H-vector after exposure with CIB. Notably, we observed about 37 % fall of mitochondrial membrane potential, activation of caspase-9 and caspase-3 and mild activation of caspase-8 without any detectable apoptotic body formation in un-irradiated HsiI cells. We conclude that reduction of PARP-1 expression activates apoptotic signals via intrinsic and extrinsic pathways in un-irradiated cells. CIB irradiation further intensified both intrinsic and extrinsic pathways of apoptosis synergistically along with up-regulation of p53 in HsiI cells resulting overall higher apoptosis in HsiI than H-vector.

Cl- channels in apoptosis

DEFF Research Database (Denmark)

Wanitchakool, Podchanart; Ousingsawat, Jiraporn; Sirianant, Lalida

2016-01-01

A remarkable feature of apoptosis is the initial massive cell shrinkage, which requires opening of ion channels to allow release of K(+), Cl(-), and organic osmolytes to drive osmotic water movement and cell shrinkage. This article focuses on the role of the Cl(-) channels LRRC8, TMEM16/anoctamin......, and cystic fibrosis transmembrane conductance regulator (CFTR) in cellular apoptosis. LRRC8A-E has been identified as a volume-regulated anion channel expressed in many cell types. It was shown to be required for regulatory and apoptotic volume decrease (RVD, AVD) in cultured cell lines. Its presence also......(-) channels or as regulators of other apoptotic Cl(-) channels, such as LRRC8. CFTR has been known for its proapoptotic effects for some time, and this effect may be based on glutathione release from the cell and increase in cytosolic reactive oxygen species (ROS). Although we find that CFTR is activated...

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

Science.gov (United States)

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

2016-04-01

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

Effects of topical vitamin E on keratocyte apoptosis after traditional photorefractive keratectomy.

Science.gov (United States)

Bilgihan, K; Adiguzel, U; Sezer, C; Akyol, G; Hasanreisoglu, B

2001-01-01

To evaluate the keratocyte apoptosis and effects of topical vitamin E on keratocyte apoptosis after photorefractive surgery. Rabbits were divided into 7 groups, and all groups were compared with controls after epithelial scraping, epithelial scrape and photorefractive keratectomy (PRK) (traditional PRK), transepithelial PRK, production of a corneal flap with microkeratome and laser-assisted in situ keratomileusis (LASIK). The effects of topical Vitamin E treatment were investigated in the traditional PRK group. The terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick-end labelling assay (to detect DNA fragmentation in situ) and light microscopy have been used to detect apoptosis in rabbit cornea. Transepithelial PRK induced minimal keratocyte apoptosis, less than in all other refractive surgical procedures. The greatest amount of keratocyte apoptosis was observed after traditional PRK (p = 0.001), therefore we tested the effects of topical vitamin E in this group. The number of apoptotic keratocytes significantly reduced after vitamin E therapy (p < 0.005). Keratocytes undergo apoptosis after refractive surgery in response to mechanical epithelial removal, preparing of corneal flap and excimer laser stromal photoablation. The topical application of vitamin E immediately after surgery can prevent keratocyte apoptosis, and this result suggests that free radicals may be partly responsible for keratocyte apoptosis after excimer laser keratectomy. Copyright 2001 S. Karger AG, Basel

Can vitamin d suppress endothelial cells apoptosis in multiple sclerosis patients?

Directory of Open Access Journals (Sweden)

Leila Dehghani

2013-01-01

Conclusion: Withregard to increment in EC apoptosis rate, which treated by the sera from MS patients and decrement in apoptosis rate by the presence of vitamin D in culture media, it could be proposed that vitamin D pre-treatment can be used for MS patients, due to its beneficial effects on protecting EC apoptosis.

Curcumin enhances TRAIL-induced apoptosis of breast cancer cells by regulating apoptosis-related proteins

Czech Academy of Sciences Publication Activity Database

Park, S.; Cho, D. J.; Anděra, Ladislav; Suh, N.; Kim, I.

2013-01-01

Roč. 383, 1-2 (2013), s. 39-48 ISSN 0300-8177 Institutional support: RVO:68378050 Keywords : TRAIL * curcumin * apoptosis * breast cancer Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.388, year: 2013

O-GlcNAcylation regulates ischemia-induced neuronal apoptosis through AKT signaling.

Science.gov (United States)

Shi, Jianhua; Gu, Jin-hua; Dai, Chun-ling; Gu, Jianlan; Jin, Xiaoxia; Sun, Jianming; Iqbal, Khalid; Liu, Fei; Gong, Cheng-Xin

2015-09-28

Apoptosis plays an important role in neural development and neurological disorders. In this study, we found that O-GlcNAcylation, a unique protein posttranslational modification with O-linked β-N-acetylglucosamine (GlcNAc), promoted apoptosis through attenuating phosphorylation/activation of AKT and Bad. By using co-immunoprecipitation and mutagenesis techniques, we identified O-GlcNAc modification at both Thr308 and Ser473 of AKT. O-GlcNAcylation-induced apoptosis was attenuated by over-expression of AKT. We also found a dynamic elevation of protein O-GlcNAcylation during the first four hours of cerebral ischemia, followed by continuous decline after middle cerebral artery occlusion (MCAO) in the mouse brain. The elevation of O-GlcNAcylation coincided with activation of cell apoptosis. Finally, we found a negative correlation between AKT phosphorylation and O-GlcNAcylation in ischemic brain tissue. These results indicate that cerebral ischemia induces a rapid increase of O-GlcNAcylation that promotes apoptosis through down-regulation of AKT activity. These findings provide a novel mechanism through which O-GlcNAcylation regulates ischemia-induced neuronal apoptosis through AKT signaling.

Molecular mechanism of X-ray-induced p53-dependent apoptosis

Energy Technology Data Exchange (ETDEWEB)

Nakano, Hisako [Tokyo Metropolitan Inst. of Medical Center (Japan)

1999-03-01

Radiation-induced cell death has been classified into the interphase- and mitotic-ones, both of which apoptosis involving. This review described the molecular mechanism of the apoptosis, focusing on its p53-dependent process. It is known that there are genes regulating cell death either negatively or positively and the latter is involved in apoptosis. As an important factor in the apoptosis, p53 has become remarkable since it was shown that X-ray-induced apoptosis required RNA and protein syntheses in thymocytes and those cells of p53 gene-depleted mouse were shown to be resistant to gamma-ray-induced apoptosis. Radiation sensitivity of MOLT-4 cells derived from human T cell leukemia, exhibiting the typical X-ray-induced p53-dependent apoptosis, depends on the levels of p53 mRNA and protein. p53 is a gene suppressing tumor and also a transcription factor. Consequently, mutation of p53 conceivably leads to the failure of cell cycle regulation, which allows damaged cells to divide without both repair and exclusion due to loss of the apoptotic mechanism, and finally results in carcinogenesis. The radiation effect occurs in the order of the cell damage, inhibition of p53-Mdm2 binding, accumulation of p53, activation of mdm2 transcription, Mdm2 accumulation, p53-protein degradation and recovery to the steady state level. Here, the cystein protease (caspases) plays an important role as a disposing mechanism for cells scheduled to die. However, many are unknown to be solved in future. (K.H.) 119 refs.

Early Contact Stage of Apoptosis: Its Morphological Features and Function

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Etheri Mikadze

2006-01-01

Full Text Available Apoptosis has been a biological phenomenon of intense interest for 20 years, but the earlier morphological features of apoptosis have not been determined hitherto. Using the methods of semi- and ultrathin sections, the livers of intact embryos and young rats have been studied under the effect of cycloheximide to determine morphological features of an early stage of apoptosis. It is discovered that both in hepatoblasts and hepatocytes, apoptosis, besides the well-known stages, also includes an early contact stage, distinguishing features of which are agglutination of bound ribosomes (breaking of translation, elimination of the nucleolus, reduction of free polysomes (and in hepatocytes, reduction of cisterns of rough endoplasmic reticulum, formation of cytoplasmic excrescences, and cell shape changes. The early stage of apoptosis is characterized by close contact with neighboring cells. At a certain phase of the contact stage of apoptosis, the nucleolus reappears in the nucleus and the number of free polysomes in the cytoplasm increases, which suggests the renewal of synthesis of new RNA and proteins. Close contact of differentiating and mitotic hepatoblasts with apoptotic cells indicates a certain functional relationship between these cells that is realized not only by micropinocytosis, but through gap junctions as well. We assume that the apoptotic cell, besides proteolytic products, can contain newly synthesized, low-molecular substances, the relocation of which from apoptotic to neighboring cells may contribute to both functional activity and proliferation of adjacent hepatoblasts and, therefore, the function of apoptosis may not be limited only to the elimination of harmful, damaged, and unwanted cells.

Hypoxia-induced p53 modulates both apoptosis and radiosensitivity via AKT

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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

Death penalty for keratinocytes: apoptosis versus cornification.

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Lippens, S; Denecker, G; Ovaere, P; Vandenabeele, P; Declercq, W

2005-11-01

Homeostasis implies a balance between cell growth and cell death. This balance is essential for the development and maintenance of multicellular organisms. Homeostasis is controlled by several mechanisms including apoptosis, a process by which cells condemned to death are completely eliminated. However, in some cases, total destruction and removal of dead cells is not desirable, as when they fulfil a specific function such as formation of the skin barrier provided by corneocytes, also known as terminally differentiated keratinocytes. In this case, programmed cell death results in accumulation of functional cell corpses. Previously, this process has been associated with apoptotic cell death. In this overview, we discuss differences and similarities in the molecular regulation of epidermal programmed cell death and apoptosis. We conclude that despite earlier confusion, apoptosis and cornification occur through distinct molecular pathways, and that possibly antiapoptotic mechanisms are implicated in the terminal differentiation of keratinocytes.

[Study on thaspine in inducing apoptosis of A549 cell].

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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.

Methylselenium and Prostate Cancer Apoptosis

National Research Council Canada - National Science Library

Lu, Junxuan

2008-01-01

The purpose of this research is to gain a better understanding of the biochemical pathways and molecular targets for the selective induction of apoptosis signaling and execution of prostate cancer (PCa...

Methylselenium and Prostate Cancer Apoptosis

National Research Council Canada - National Science Library

Lu, Junxuan

2005-01-01

The purpose of this research is to gain a better understanding of the biochemical pathways and molecular targets for the selective induction of apoptosis signaling and execution of prostate cancer (PCa...

Methylselenium and Prostate Cancer Apoptosis

National Research Council Canada - National Science Library

Lu, Junxuan

2007-01-01

The purpose of this research is to gain a better understanding of the biochemical pathways and molecular targets for the selective induction of apoptosis signaling and execution of prostate cancer (PCa...

Methylselenium and Prostate Cancer Apoptosis

National Research Council Canada - National Science Library

Lu, Junxuan

2006-01-01

The purpose of this research is to gain a better understanding of the biochemical pathways and molecular targets for the selective induction of apoptosis signaling and execution of prostate cancer (PCa...

Atrazine-induced apoptosis of splenocytes in BALB/C mice

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Zheng Jing

2011-10-01

Full Text Available Abstract Background Atrazine (2-chloro-4-ethytlamino-6-isopropylamine-1,3,5-triazine; ATR, is the most commonly applied broad-spectrum herbicide in the world. Unintentional overspray of ATR poses an immune function health hazard. The biomolecular mechanisms responsible for ATR-induced immunotoxicity, however, are little understood. This study presents on our investigation into the apoptosis of splenocytes in mice exposed to ATR as we explore possible immunotoxic mechanisms. Methods Oral doses of ATR were administered to BALB/C mice for 21 days. The histopathology, lymphocyte apoptosis and the expression of apoptosis-related proteins from the Fas/Fas ligand (FasL apoptotic pathway were examined from spleen samples. Results Mice administered ATR exhibited a significant decrease in spleen and thymus weight. Electron microscope histology of ultrathin sections of spleen revealed degenerative micromorphology indicative of apoptosis of splenocytes. Flow cytometry revealed that the percentage of apoptotic lymphocytes increased in a dose-dependent manner after ATR treatment. Western blots identified increased expression of Fas, FasL and active caspase-3 proteins in the treatment groups. Conclusions ATR is capable of inducing splenocytic apoptosis mediated by the Fas/FasL pathway in mice, which could be the potential mechanism underlying the immunotoxicity of ATR.

Apoptosis - Triggering Effects: UVB-irradiation and Saccharomyces cerevisiae.

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Behzadi, Payam; Behzadi, Elham

2012-12-01

The pathogenic disturbance of Saccharomyces cerevisiae is known as a rare but invasive nosocomial fungal infection. This survey is focused on the evaluation of apoptosis-triggering effects of UVB-irradiation in Saccharomyces cerevisiae. The well-growth colonies of Saccharomyces cerevisiae on Sabouraud Dextrose Agar (SDA) were irradiated within an interval of 10 minutes by UVB-light (302 nm). Subsequently, the harvested DNA molecules of control and UV-exposed yeast colonies were run through the 1% agarose gel electrophoresis comprising the luminescent dye of ethidium bromide. No unusual patterns including DNA laddering bands or smears were detected. The applied procedure for UV exposure was not effective for inducing apoptosis in Saccharomyces cerevisiae. So, it needs another UV-radiation protocol for inducing apoptosis phenomenon in Saccharomyces cerevisiae.

The effect of melatonin on mouse jejunal crypt cell survival and apoptosis

International Nuclear Information System (INIS)

Kang, Jin Oh; Ha, Eun Young; Baik, Hyung Hwan; Cho, Yong Ho; Hong, Seong Eon

2000-01-01

To evaluate protective mechanism of melatonin against radiation damage and its relationship with apoptosis in mouse jejunum. 168 mice were divided into 28 groups according to radiation dose and melatonin treatment. To analysis crypt survival, microcolony survival assay was done according to Withers and Elkind's method. To analysis apoptosis, TUNEL assay was done according to Labet-Moleur's method. Radiation protection effect of melatonin was demonstrated by crypt survival assay and its effect was stronger in high radiation dose area. Apoptosis index with 8 Gy irradiation was 18.4% in control group and 16.5% in melatonin treated group. After 18 Gy, apoptosis index was 17.2%in control group and 15.4% in melatonin treated group. Apoptosis index did not show statistically significant difference between melatonin shows clear protective effect in mouse jejunum against radiation damage but its protective effect seems not to be related with apoptosis protection effect

Bim is a crucial regulator of apoptosis induced by Mycobacterium tuberculosis

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

2014-01-01

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

Comparative study on 4 quantitative detection methods of apoptosis induced by radiation

International Nuclear Information System (INIS)

Yang Yepeng; Chen Guanying; Zhou Mei; Shen Qinjian; Shen Lei; Zhu Yingbao

2004-01-01

Objective: To reveal the capability of 4 apoptosis-detecting methods to discriminate between apoptosis and necrosis and show their respective advantages and shortcomings through comparison of detected results and analysis of detection mechanism. Methods: Four methods, PI staining-flow cytometric detection (P-F method), TUNEL labeling-flow cytometric detection (T-F method), annexing V-FITC/PI vital staining-flow cytometric detection (A-F method) and Hoechst/PI vital staining-fluorescence microscopic observation (H-O method), were used to determine apoptosis and necrosis in human breast cancer MCF-7 cell line induced by γ-rays. Hydroxycamptothecine and sodium azide were used to induce positive controls of apoptosis and necrosis respectively. Results: All 4 methods showed good time-dependent and dose dependent respondence to apoptosis induced by γ-rays and hydroxycamptothecine. Apoptotic cell ratios and curve slopes obtained from P-F method were minimum and, on the contrary, those from T-F method were maximum among these 4 methods. With A-F method and H-O method, two sets of data, apoptosis and necrosis, could be gained respectively and the data gained from these two methods were close to equal. A-F method and H-O method could distinguish necrosis induced by sodium azide from apoptosis while P-F method and T-F method presented false increase of apoptosis. Conclusions: P-F method and T-F method can not discriminate between apoptosis and necrosis. P-F method is less sensitive but more simple, convenient and economical than T-F method. A-F method and H-O method can distinguish necrosis from apoptosis. A-F method is more costly but more quick and reliable than H-O method. H-O method is economical, practical and morphological changes of cells and nucleus can be observed simultaneously with it. (authors)

Cytosolic labile zinc: a marker for apoptosis in the developing rat brain.

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Lee, Joo-Yong; Hwang, Jung Jin; Park, Mi-Ha; Koh, Jae-Young

2006-01-01

Cytosolic zinc accumulation was thought to occur specifically in neuronal death (necrosis) following acute injury. However, a recent study demonstrated that zinc accumulation also occurs in adult rat neurons undergoing apoptosis following target ablation, and in vitro experiments have shown that zinc accumulation may play a causal role in various forms of apoptosis. Here, we examined whether intraneuronal zinc accumulation occurs in central neurons undergoing apoptosis during development. Embryonic and newborn Sprague-Dawley rat brains were double-stained for terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelling (TUNEL) detection of apoptosis and immunohistochemical detection of stage-specific neuronal markers, such as nestin, proliferating cell nuclear antigen (PCNA), TuJ1 and neuronal nuclear specific protein (NeuN). The results revealed that apoptotic cell death occurred in neurons of diverse stages (neural stem cells, and dividing, young and adult neurons) throughout the brain during the embryonic and early postnatal periods. Further staining of brain sections with acid fuchsin or zinc-specific fluorescent dyes showed that all of the apoptotic neurons were acidophilic and contained labile zinc in their cell bodies. Cytosolic zinc accumulation was also observed in cultured cortical neurons undergoing staurosporine- or sodium nitroprusside (SNP)-induced apoptosis. In contrast, zinc chelation with CaEDTA or N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) reduced SNP-induced apoptosis but not staurosporine-induced apoptosis, indicating that cytosolic zinc accumulation does not play a causal role in all forms of apoptosis. Finally, the specific cytosolic zinc accumulation may have a practical application as a relatively simple marker for neurons undergoing developmental apoptosis.

Mitochondria in neutrophil apoptosis

NARCIS (Netherlands)

van Raam, B. J.; Verhoeven, A. J.; Kuijpers, T. W.

2006-01-01

Central in the regulation of the short life span of neutrophils are their mitochondria. These organelles hardly contribute to the energy status of neutrophils but play a vital role in the apoptotic process. Not only do the mitochondria contain cytotoxic proteins that are released during apoptosis

Effects of P-Glycoprotein and Its Inhibitors on Apoptosis in K562 Cells

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Yaqiong Zu

2014-08-01

Full Text Available P-glycoprotein (P-gp is a major factor in multidrug resistance (MDR which is a serious obstacle in chemotherapy. P-gp has also been implicated in causing apoptosis of tumor cells, which was shown to be another important mechanism of MDR recently. To study the influence of P-gp in tumor cell apoptosis, K562/A cells (P-gp+ and K562/S cells (P-gp− were subjected to doxorubicin (Dox, serum withdrawal, or independent co-incubation with multiple P-gp inhibitors, including valspodar (PSC833, verapamil (Ver and H108 to induce apoptosis. Apoptosis was simultaneously detected by apoptotic rate, cell cycle by flow cytometry and cysteine aspartic acid-specific protease 3 (caspase 3 activity by immunoassay. Cytotoxicity and apoptosis induced by PSC833 were evaluated through an MTT method and apoptosis rate, and cell cycle combined with caspase 3 activity, respectively. The results show that K562/A cells are more resistant to apoptosis and cell cycle arrest than K562/S cells after treatment with Dox or serum deprivation. The apoptosis of K562/A cells increased after co-incubation with each of the inhibitors of P-gp. P-gp inhibitors also enhanced cell cycle arrest in K562/A cell. PSC833 most strikingly decreased viability and led to apoptosis and S phase arrest of cell cycle in K562/A cells. Our study demonstrates that P-gp inhibits the apoptosis of tumor cells in addition to participating in the efflux of intracellular chemotherapy drugs. The results of the caspase 3 activity assay also suggest that the role of P-gp in apoptosis avoidance is caspase-related.

Apoptosis and T cell depletion during feline infectious peritonitis

NARCIS (Netherlands)

Horzinek, M.C.; Haagmans, B.L.; Egberink, H.F.

1996-01-01

Cats that have succumbed to feline infectious peritonitis, an immune- mediated disease caused by variants of feline coronaviruses, show apoptosis and T-cell depletion in their lymphoid organs. The ascitic fluid that develops in the course of the condition causes apoptosis in vitro but only in

Increased lung neutrophil apoptosis and inflammation resolution in nonresponding pneumonia.

Science.gov (United States)

Moret, I; Lorenzo, M J; Sarria, B; Cases, E; Morcillo, E; Perpiñá, M; Molina, J M; Menéndez, R

2011-11-01

Neutrophil activation state and its relationship with an inflammatory environment in community-acquired pneumonia (CAP) remain insufficiently elucidated. We aimed to evaluate the neutrophil apoptosis and cytokine pattern in CAP patients after 72 h of treatment, and their impact on infection resolution. Apoptosis of blood and bronchoalveolar lavage (BAL) neutrophils was measured in nonresponding CAP (NCAP), in responding CAP (blood only) and in patients without infection (control). Pro-inflammatory (interleukin (IL)-6, IL-8) and anti-inflammatory (IL-10) cytokines were measured. Main outcomes were clinical stability and days of hospitalisation. Basal neutrophil apoptosis was higher in the BAL and blood of NCAP, whereas spontaneous apoptosis (after 24 h culture) was lower. Cytokines in NCAP were higher than in responding CAP and control: IL-6 was increased in BAL and blood, IL-8 in BAL and IL-10 in blood. An increased basal apoptosis (≥20%) in BAL of NCAP was associated with lower systemic IL-10 (p<0.01), earlier clinical stability (p=0.05) and shorter hospital stay (p=0.02). A significant correlation was found for systemic IL-6 and IL-10 with days to reach stability and length of stay. After 72 h of treatment, an increased basal alveolar neutrophil apoptosis might contribute to downregulation of inflammation and to faster clinical stability.

Anaplasma phagocytophilum Manipulates Host Cell Apoptosis by Different Mechanisms to Establish Infection

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Pilar Alberdi

2016-07-01

Full Text Available Anaplasma phagocytophilum is an emerging zoonotic pathogen that causes human and animal granulocytic anaplasmosis and tick-borne fever of ruminants. This obligate intracellular bacterium evolved to use common strategies to establish infection in both vertebrate hosts and tick vectors. Herein, we discuss the different strategies used by the pathogen to modulate cell apoptosis and establish infection in host cells. In vertebrate neutrophils and human promyelocytic cells HL-60, both pro-apoptotic and anti-apoptotic factors have been reported. Tissue-specific differences in tick response to infection and differential regulation of apoptosis pathways have been observed in adult female midguts and salivary glands in response to infection with A. phagocytophilum. In tick midguts, pathogen inhibits apoptosis through the Janus kinase/signal transducers and activators of transcription (JAK/STAT pathway, while in salivary glands, the intrinsic apoptosis pathways is inhibited but tick cells respond with the activation of the extrinsic apoptosis pathway. In Ixodes scapularis ISE6 cells, bacterial infection down-regulates mitochondrial porin and manipulates protein processing in the endoplasmic reticulum and cell glucose metabolism to inhibit apoptosis and facilitate infection, whereas in IRE/CTVM20 tick cells, inhibition of apoptosis appears to be regulated by lower caspase levels. These results suggest that A. phagocytophilum uses different mechanisms to inhibit apoptosis for infection of both vertebrate and invertebrate hosts.

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.

Noxa/Mcl-1 Balance Regulates Susceptibility of Cells to Camptothecin-Induced Apoptosis

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Yide Mei

2007-10-01

Full Text Available Although camptothecin (CPT has been reported to induce apoptosis in various cancer cells, the molecular details of this regulation remain largely unknown. In this study, we demonstrate that 131-113-only protein Noxa is upregulated during CPT-induced apoptosis, which is independent of p53. In addition, we show that phosphatidylinositol 3-kinase (PI3K/Akt signaling pathway is responsible for Noxa's induction. Luciferase assay, cAMP response element binding protein (CREB knockdown experiments further demonstrate that CREB is involved in the transcriptional upregulation of Noxa. Moreover, blocking Noxa expression using specific small interfering ribonucleic acid (siRNA significantly reduces the apoptosis in response to CPT, indicating that Noxa is an essential mediator for CPT-induced apoptosis. Interestingly, antiapoptotic Mcl-1 was also upregulated through PI3K/Akt signaling pathway upon CPT treatment. Using immunoprecipitation assay, Noxa was found to interact with Mcl-1 in the presence or absence of CPT. Knockdown of Mcl-1 expression by short hairpin ribonucleic acid (shRNA was shown to potentiate CPT-induced apoptosis. Consistently, ectopic overexpression of Mcl-1 rescued cells from apoptosis induced by CPT. Cells coexpressing Noxa, Mcl-1 at different ratio correlates well with the extent of apoptosis, suggesting that the balance between Noxa, Mcl-1 may determine the susceptibility of HeLa cells to CPT-induced apoptosis.

Reassessing apoptosis in plants.

Science.gov (United States)

Dickman, Martin; Williams, Brett; Li, Yurong; de Figueiredo, Paul; Wolpert, Thomas

2017-10-01

Cell death can be driven by a genetically programmed signalling pathway known as programmed cell death (PCD). In plants, PCD occurs during development as well as in response to environmental and biotic stimuli. Our understanding of PCD regulation in plants has advanced significantly over the past two decades; however, the molecular machinery responsible for driving the system remains elusive. Thus, whether conserved PCD regulatory mechanisms include plant apoptosis remains enigmatic. Animal apoptotic regulators, including Bcl-2 family members, have not been identified in plants but expression of such regulators can trigger or suppress plant PCD. Moreover, plants exhibit nearly all of the biochemical and morphological features of apoptosis. One difference between plant and animal PCD is the absence of phagocytosis in plants. Evidence is emerging that the vacuole may be key to removal of unwanted plant cells, and may carry out functions that are analogous to animal phagocytosis. Here, we provide context for the argument that apoptotic-like cell death occurs in plants.

Cytosolic NADP(+)-dependent isocitrate dehydrogenase regulates cadmium-induced apoptosis.

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Shin, Seoung Woo; Kil, In Sup; Park, Jeen-Woo

2010-04-01

Cadmium ions have a high affinity for thiol groups. Therefore, they may disturb many cellular functions. We recently reported that cytosolic NADP(+)-dependent isocitrate dehydrogenase (IDPc) functions as an antioxidant enzyme to supply NADPH, a major source of reducing equivalents to the cytosol. Cadmium decreased the activity of IDPc both as a purified enzyme and in cultured cells. In the present study, we demonstrate that the knockdown of IDPc expression in HEK293 cells greatly enhances apoptosis induced by cadmium. Transfection of HEK293 cells with an IDPc small interfering RNA significantly decreased the activity of IDPc and enhanced cellular susceptibility to cadmium-induced apoptosis as indicated by the morphological evidence of apoptosis, DNA fragmentation and condensation, cellular redox status, mitochondria redox status and function, and the modulation of apoptotic marker proteins. Taken together, our results suggest that suppressing the expression of IDPc enhances cadmium-induced apoptosis of HEK293 cells by increasing disruption of the cellular redox status. Copyright 2009 Elsevier Inc. All rights reserved.

Measurement and Characterization of Apoptosis by Flow Cytometry.

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Telford, William; Tamul, Karen; Bradford, Jolene

2016-07-01

Apoptosis is an important mechanism in cell biology, playing a critical regulatory role in virtually every organ system. It has been particularly well characterized in the immune system, with roles ranging from immature immune cell development and selection to down-regulation of the mature immune response. Apoptosis is also the primary mechanism of action of anti-cancer drugs. Flow cytometry has been the method of choice for analyzing apoptosis in suspension cells for more than 25 years. Numerous assays have been devised to measure both the earliest and latest steps in the apoptotic process, from the earliest signal-transduction events to the late morphological changes in cell shape and granularity, proteolysis, and chromatin condensation. These assays are particularly powerful when combined into multicolor assays determining several apoptotic characteristics simultaneously. The multiparametric nature of flow cytometry makes this technology particularly suited to measuring apoptosis. In this unit, we will describe the four main techniques for analyzing caspase activity in apoptotic cells, combined with annexin V and cell permeability analysis. These relatively simple multiparametric assays are powerful techniques for assessing cell death. © 2016 by John Wiley & Sons, Inc. Copyright © 2016 John Wiley & Sons, Inc.

Effect of radiation on apoptosis in small intestine and colon of mice

International Nuclear Information System (INIS)

Ding Guirong; Guo Guozhen; Tian Furong; Wang Jin; Zhang Liyan; Guo Yao

2000-01-01

To discuss the changes of apoptosis level in small bowel and colon of mice after γ-ray irradiation. The mice were irradiated with different doses (1,6,12 Gy). The incidence of apoptosis in small bowel and colon were observed at different time (6,12,24h) after irradiation using morphological method. Then results indicate that there were apoptosis in small bowel of normal mice, the number of apoptotic cell was 0.038 +- 0.059 per whole crypt. No apoptosis was observed in colon of normal mice and irradiated mice; The incidence of apoptosis significantly increased in small bowel after different doses of irradiation (p < 0.05). The apoptosis peak appeared at 12, 24, 6 h after 1, 6, 12 Gy irradiation; The incidence of apoptosis was higher in small bowel than that of colon after different doses of irradiation and at different time after irradiation. From the results the authors propose that the radiation-damaged cells might be more effectively removed in small bowel than in colon after irradiation. Radiation-damaged cells may tend to remain in colon and related to later tumorigenesis

Tempo enhances heat-induced apoptosis by mitochondrial targeting of Bax

International Nuclear Information System (INIS)

Zhao, Q.-L.; Fujiwara, Y.; Kondo, T.

2003-01-01

A stable membrane-permeable nitroxide, Tempo, exerts an SOD-like antioxidant activity against ROS. Reportedly, Tempo inhibits ROS-induced thymocyte apoptosis, while 10 mM Tempo activates JNK1 to induce apoptosis in breast cancer cells. We have observed that nontoxic 5 mM Tempo enhances suboptimal hyperthermia (44 deg C/10 min)-induced apoptosis in U937 cells. Here we report the enhancing mechanism, focusing on activation and targeting of Bax to mitochondria and cytochrome c release. Methods: U937 cells were treated with either Tempo (5 mM, 37 deg C/10 min), heating (44 deg C/10 min), or Tempo-plus-heating, washed and incubated for various times up to 6 h, until assessing apoptosis, mitochondrial potential (ΔΨ>), and amount of superoxide by flow cytometry using Annexin V-FITC/PI, TMRM, and dihydroethidium, respectively. Bax, Bcl-2 and Bcl-XL, and cytochrome c were detected by western blotting, activated Bax was by immunoprecipitation, and ATP was by a luciferase assay. Bax targeting to and cytochrome c release from mitochorndria were also detected immunocytochemically under fluorescent microscopy. Results and Discussion: Treatment of U937 cells with 5 mM Tempo for 10 min at 37 deg C or suboptimal heating (44 deg C/ 10 min) alone did not induce apoptosis. The combined treatment with 5 mM Tempo and 44 deg C for 10 min dramatically induced ∼90% apoptosis in 6 h, as did the 44 deg C/30 min heating. During the enhanced apoptosis, cytochrome c release progressed. Although signals of Bcl-2, Bcl-XL and Bax in cell lysates were not altered, Bax was specifically activated and translocated to mitochondria after the combined treatment. Further, loss of ΔΨ>and decreases in superoxide and ATP progressed after the combined treatment, suggesting that the treatment may disturb mitochondrial electron transport. Thus, Tempo sensitizes the heat-induced apoptosis through (1) targeting of Bax to mitochondria and releasing cytochrome c, and (2) mitochondrial dysfunction

Oxidative Stress-Responsive Apoptosis Inducing Protein (ORAIP) Plays a Critical Role in High Glucose-Induced Apoptosis in Rat Cardiac Myocytes and Murine Pancreatic β-Cells.

Science.gov (United States)

Yao, Takako; Fujimura, Tsutomu; Murayama, Kimie; Okumura, Ko; Seko, Yoshinori

2017-10-18

We previously identified a novel apoptosis-inducing humoral factor in the conditioned medium of hypoxic/reoxygenated-cardiac myocytes. We named this novel post-translationally-modified secreted-form of eukaryotic translation initiation factor 5A Oxidative stress-Responsive Apoptosis-Inducing Protein (ORAIP). We confirmed that myocardial ischemia/reperfusion markedly increased plasma ORAIP levels and rat myocardial ischemia/reperfusion injury was clearly suppressed by neutralizing anti-ORAIP monoclonal antibodies (mAbs) in vivo. In this study, to investigate the mechanism of cell injury of cardiac myocytes and pancreatic β-cells involved in diabetes mellitus (DM), we analyzed plasma ORAIP levels in DM model rats and the role of ORAIP in high glucose-induced apoptosis of cardiac myocytes in vitro. We also examined whether recombinant-ORAIP induces apoptosis in pancreatic β-cells. Plasma ORAIP levels in DM rats during diabetic phase were about 18 times elevated as compared with non-diabetic phase. High glucose induced massive apoptosis in cardiac myocytes (66.2 ± 2.2%), which was 78% suppressed by neutralizing anti-ORAIP mAb in vitro. Furthermore, recombinant-ORAIP clearly induced apoptosis in pancreatic β-cells in vitro. These findings strongly suggested that ORAIP plays a pivotal role in hyperglycemia-induced myocardial injury and pancreatic β-cell injury in DM. ORAIP will be a biomarker and a critical therapeutic target for cardiac injury and progression of DM itself.

Peripheral Blood Leucocyte Apoptosis in Two Dogs Infected with ...

African Journals Online (AJOL)

Blood leucocyte apoptosis in the trypanosome-infected natural hosts is yet to be documented and recognized as a feature of trypanosomiasis. We provide evidence of marked peripheral blood leucocyte apoptosis in two cases of dogs severely infected with Trypanosoma congolense. It is expected that this case report will ...

MicroRNAs regulate B-cell receptor signaling-induced apoptosis

NARCIS (Netherlands)

Kluiver, J. L.; Chen, C-Z

Apoptosis induced by B-cell receptor (BCR) signaling is critical for antigen-driven selection, a process critical to tolerance and immunity. Here, we examined the roles of microRNAs (miRNAs) in BCR signaling-induced apoptosis using the widely applied WEHI-231 model. Comparison of miRNA levels in

Methylselenium and Prostate Cancer Apoptosis

National Research Council Canada - National Science Library

Lu, Junxuan

2003-01-01

The purpose of this research is to gain a better understanding of the biochemical pathways and molecular targets for the selective induction of apoptosis signaling and execution of PCa cells by methyl selenium (Se...

Radiation-induced apoptosis of lymphocytes in peripheral blood

International Nuclear Information System (INIS)

Oh, Yoon Kyeong; Lee, Tae Bum; Nam, Taek Keun; Kee, Keun Hong; Choi, Cheol Hee

2003-01-01

This study quantitatively evaluated the apoptosis in human peripheral blood lymphocytes using flow cytometry, and investigated the possibility of using this method, with a small amount of blood, and the time and dose dependence of radiation-induced apoptosis. Peripheral blood lymphocytes were isolated from the heparinized venous blood of 11 healthy volunteers, 8 men and 3 women, with each 10 ml of blood being divided into 15 samples. The blood lymphocytes were irradiated using a linear accelerator at a dose rate of 2.4 Gy/min, to deliver doses of 0.5, 1, 2 and 5 Gy. The control samples, and irradiated cells, were maintained in culture medium for 24, 48 and 72 hours following the irradiation. The number of apoptotic cells after the in vitro X-irradiation was measured by flow cytometry after incubation periods of 24, 48 and 72 hours. We also observed the apoptotic cells using a DNA fragmentation assay and electron microscopy. The rate of spontaneous apoptosis increased in relation to the time interval following irradiation (1.761±0.161, 3.563±0.564, 11.098±2.849, at 24, 48, and 72 hours). The apoptotic cells also increased in the samples irradiated with 0.5, 1, 2 and 5 Gy, in a radiation dose and time interval after irradiation manner, with the apoptosis being too great at 72 hours after irradiation. The dose-response curves were characterized by an initial steep increase in the number of apoptotic cells for irradiation doses below 2 Gy, with a flattening of the curves as the dose approached towards 5 Gy. The flow cytometric assay technique yielded adequate data, and required less than 1 mL of blood. The time and dose dependence of the radiation-induced apoptosis, was also shown. It is suggested that the adequate time interval required for the evaluation of apoptosis would be 24 to 48 hours after blood sampling

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.

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.

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.

Dose-effect relationship of apoptosis induced by fission-neutron in murine thymocytes

International Nuclear Information System (INIS)

Yuan Bin; Li Liang; Xue Wencheng; Sun Jianmin; Wang Baoqin

2000-01-01

Objective: To investigate the effectiveness of high LET fission-neutron to induce apoptosis in murine thymocytes and to compare it with that of low LET 60 Co γ-ray. Methods: Apoptosis induction was studied qualitatively by light and transmission electron microscopy and DNA gel electrophoresis,also quantitatively by flow cytometry(FCM) and diphenylamine (DPA)methods. Results: DNA ladders of murine thymocytes were detectable, the typical apoptosis of thymocytes could be observed morphologically by means of light and electron microscopy at 6 h after fission-neutron irradiation with doses ranging from 0.5 to 5.0 Gy, meanwhile the percentages of apoptosis increased with increasing doses. After exposure to γ-rays with doses ranging from 1.0 to 30 Gy, the experimental results were similar to those from neutron radiation. The incidence of apoptosis peaked at about 20 Gy, the percentages did not increase further when doses increased. Conclusion: Apoptosis of murine thymocytes can be induced when mice are exposed to either fission-neutron (0.5-5.0 Gy) or to γ-ray (1-30 Gy). Although the relationship between apoptosis and radiation doses is similar, the percentage of apoptosis induced by neutron irradiation is higher than that induced by γ-irradiation. The RBE values of fission-neutron for inducing apoptosis murine thymocytes are 2.09 (by FCM method) and 2.37 (by DPA method), respectively. These results also suggest that fission-neutron-induced murine immune tissue is more severe than that induced by γ-rays at several hours post-irradiation and this might be the basis for heavy damage to immune tissues induced by fission-neutron-irradiation in later period

Cellular zinc fluxes and the regulation of apoptosis/gene-directed cell death.

Science.gov (United States)

Truong-Tran, A Q; Ho, L H; Chai, F; Zalewski, P D

2000-05-01

The maintenance of discrete subcellular pools of zinc (Zn) is critical for the functional and structural integrity of cells. Among the important biological processes influenced by Zn is apoptosis, a process that is important in cellular homeostasis (an important cellular homeostatic process). It has also been identified as a major mechanism contributing to cell death in response to toxins and in disease, offering hope that novel therapies that target apoptotic pathways may be developed. Because Zn levels in the body can be increased in a relatively nontoxic manner, it may be possible to prevent or ameliorate degenerative disorders that are associated with high rates of apoptotic cell death. This review begins with brief introductions that address, first, the cellular biology of Zn, especially the critical labile Zn pools, and, second, the phenomenon of apoptosis. We then review the evidence relating Zn to apoptosis and address three major hypotheses: (1) that a specific pool or pools of intracellular labile Zn regulates apoptosis; (2) that systemic changes in Zn levels in the body, due to dietary factors, altered physiological states or disease, can influence cell susceptibility to apoptosis, and (3) that this altered susceptibility to apoptosis contributes to pathophysiological changes in the body. Other key issues are the identity of the molecular targets of Zn in the apoptotic cascade, the types of cells and tissues most susceptible to Zn-regulated apoptosis, the role of Zn as a coordinate regulator of mitosis and apoptosis and the apparent release of tightly bound intracellular pools of Zn during the later stages of apoptosis. This review concludes with a section highlighting areas of priority for future studies.

LP-THAE induced tumor cell apoptosis of rabbit VX2 liver carcinoma

International Nuclear Information System (INIS)

Chen Shengli; Quan Yi; Huang Zicheng; Chen Guodong; Zhu Dongliang

2007-01-01

Objective: To research tumor cell apoptosis induced by Lp-THAE of rabbit VX2 liver implanted tumor. Methods: 27 New Zealand white rabbits implanted with VX2 tumor at left middle lobe of the liver divided into three groups: Group A(n= 9) Lp-THAE: treated through transhepatic artery catheterization; Group B(n=9) THAI and Group C(n=9) as control. The rabbits were executed at second to fifth day after treatment. HE dye microscopy was taken for counting the typical apoptosis cells and calculating apoptosis index (ApI). FITC-AnnexinV/PI assay was used for measuring apoptosis by flow cytometry. Results: The ApI of tumor central area and marginal area were (17.769±2.417)%, (4.129±1.172)%, P<0.01. The percentages of tumor cell apoptosis and tumor cell necrosis were (16.483±1.404)%, (9.478±0.964)%, P<0.01 and (43.559±5.053)%, (33.460±1.840)%, P=0.093. The total percentages of tumor cell apoptosis and necrosis were (60.042±13.979)%, (42.938±8.979)%, P< 0.01, at tumor center and marginal area in THAE group respectively. The ApI, percentages of tumor cell apoptosis and necrosis in THAE group were significantly higher than those of THAI group (P<0.01). The percentages of tumor cell apoptosis at tumor center area in THAE group were significantly higher than those of tumor marginal area(P<0.01). Conclusion: Induced tumor cell apoptosis and necrosis are two mechanisms of action for Lp-THAE treatment of liver carcinoma. (authors)

Methylselenium and Prostate Cancer Apoptosis

National Research Council Canada - National Science Library

Lu, Junxuan

2004-01-01

The purpose of this research is to gain a better understanding of the biochemical pathways and molecular targets for the selective induction of apoptosis signaling and execution of PCa cells by methyl selenium (Se)/selenol...

Infección por el virus de la Lengua azul: activación de señales celulares que inducen apoptosis Bluetongue virus infection: signaling pathway activated during apoptosis

Directory of Open Access Journals (Sweden)

E. Mortola

2009-09-01

Full Text Available El virus de la Lengua azul (VLA es un ARN virus de doble cadena que induce apoptosis tanto en cultivos celulares como en tejidos blanco. Con el fin de dilucidar el mecanismo de apoptosis en la infección por el VLA, en el presente trabajo examinamos en detalle, por la técnica de Western blot, las señales celulares de caspasas, Bax, citocromo c, Smac/DIABLO y factor nuclear kappa B (NF-kB que se activan en la infección viral. Hemos comprobado que luego de la infección in vitro con el VLA, se detectó la activación de la caspasa 8 y con ello el mecanismo extrínseco de la apoptosis. También detectamos por primera vez no sólo la activación de miembros de la familia Bcl-2 (Bax, sino también la liberación del citocromo c y la proteína Smac/DIABLO, confirmando que en la infección por el VLA está involucrado el mecanismo secuencial intrínseco de la apoptosis. Asimismo, demostramos que la infección por el VLA activa el NF-kB y que la apoptosis es sustancialmente reducida mediante la inhibición del mismo. La activación de las señales celulares tales como Bax, citocromo c, Smac/DIABLO y NF-kB presentados en este trabajo, esclarecen los mecanismos apoptóticos durante la infección por el VLA para una mayor comprensión del papel primario que juega la apoptosis en la patogénesis del virus.Bluetongue (BTV is a double-stranded RNA virus that induces apoptosis both in mammalian cell cultures and in target tissues. To elucidate the apoptosis pathways in BTV infection, we have examined in detail the apoptosis mechanism by examination of caspases, Bax, cytochrome c, Smac/DIABLO and NF-kB signalling pathways. In this report, after cell infection with BTV, the activation of caspase 8 was detected, proving the extrinsic receptor binding apoptotic pathway. Apoptosis followed a sequential pathway involving the detection of activated Bcl-2 family members. Furthermore, its translocation to the mitochondria, as well as the release of cytochrome c and

Apoptosis in chondrogenesis of human mesenchymal stem cells: effect of serum and medium supplements.

Science.gov (United States)

Wang, Chien-Yuan; Chen, Ling-Lan; Kuo, Pei-Yin; Chang, Jia-Ling; Wang, Yng-Jiin; Hung, Shih-Chieh

2010-04-01

Apoptosis is an inevitable process during development and is evident in the formation of articular cartilage and endochondral ossification of growth plate. Mesenchymal stem cells (MSCs) can serve as alternative sources for cell therapy in focal chondral lesions or diffuse osteoarthritis. But there are few, if any, studies investigating apoptosis during chondrogenesis by MSCs. The aim of this study was to find the better condition to prevent apoptosis during chondrogenesis by MSCs. Apoptosis were evaluated in MSCs induced in different chondrogenic media by the use of Annexin V, TUNEL staining, lysosomal labeling with lysotracker and immunostaining of apoptotic markers. We found apparent apoptosis was demonstrated by Annexin V, TUNEL staining and lysosomal labeling during chondrogenesis. Meanwhile, the degree of apoptosis was related to the reagents of the defined chondrogenic medium. Adding serum in medium increased apoptosis, however, TGF-beta1 inhibited apoptosis. The apoptosis was associated with the activation of caspase-3, the increase in the Bax/Bcl-2 ratio, the loss of lysosomal integrity, and the increase of PARP-cleavage. Pro-inflammatory cytokines, IL-1alpha, IL-1beta and TNFalpha did not induce any increase in apoptosis. Interestingly, the inhibition of apoptosis by serum free medium supplemented with ITS was also associated with an increase in the expression of type II collagen, and a decrease in the expression of type X collagen, Runx2, and other osteogenic genes, while TGF-beta1 increased the expression of Sox9, type II and type X collagen and decreased the expression of osteogenic genes. These data suggest apoptosis occurs during chondrogenesis by MSCs by cell death intrinsic pathway activation and this process may be modulated by culture conditions.

Apoptosis and Vocal Fold Disease: Clinically Relevant Implications of Epithelial Cell Death

Science.gov (United States)

Novaleski, Carolyn K.; Carter, Bruce D.; Sivasankar, M. Preeti; Ridner, Sheila H.; Dietrich, Mary S.; Rousseau, Bernard

2017-01-01

Purpose: Vocal fold diseases affecting the epithelium have a detrimental impact on vocal function. This review article provides an overview of apoptosis, the most commonly studied type of programmed cell death. Because apoptosis can damage epithelial cells, this article examines the implications of apoptosis on diseases affecting the vocal fold…

Investigating the evolution of apoptosis in malaria parasites: the importance of ecology

Directory of Open Access Journals (Sweden)

Pollitt Laura C

2010-11-01

Full Text Available Abstract Apoptosis is a precisely regulated process of cell death which occurs widely in multicellular organisms and is essential for normal development and immune defences. In recent years, interest has grown in the occurrence of apoptosis in unicellular organisms. In particular, as apoptosis has been reported in a wide range of species, including protozoan malaria parasites and trypanosomes, it may provide a novel target for intervention. However, it is important to understand when and why parasites employ an apoptosis strategy before the likely long- and short-term success of such an intervention can be evaluated. The occurrence of apoptosis in unicellular parasites provides a challenge for evolutionary theory to explain as organisms are expected to have evolved to maximise their own proliferation, not death. One possible explanation is that protozoan parasites undergo apoptosis in order to gain a group benefit from controlling their density as this prevents premature vector mortality. However, experimental manipulations to examine the ultimate causes behind apoptosis in parasites are lacking. In this review, we focus on malaria parasites to outline how an evolutionary framework can help make predictions about the ecological circumstances under which apoptosis could evolve. We then highlight the ecological considerations that should be taken into account when designing evolutionary experiments involving markers of cell death, and we call for collaboration between researchers in different fields to identify and develop appropriate markers in reference to parasite ecology and to resolve debates on terminology.

Detrended cross-correlation coefficient: Application to predict apoptosis protein subcellular localization.

Science.gov (United States)

Liang, Yunyun; Liu, Sanyang; Zhang, Shengli

2016-12-01

Apoptosis, or programed cell death, plays a central role in the development and homeostasis of an organism. Obtaining information on subcellular location of apoptosis proteins is very helpful for understanding the apoptosis mechanism. The prediction of subcellular localization of an apoptosis protein is still a challenging task, and existing methods mainly based on protein primary sequences. In this paper, we introduce a new position-specific scoring matrix (PSSM)-based method by using detrended cross-correlation (DCCA) coefficient of non-overlapping windows. Then a 190-dimensional (190D) feature vector is constructed on two widely used datasets: CL317 and ZD98, and support vector machine is adopted as classifier. To evaluate the proposed method, objective and rigorous jackknife cross-validation tests are performed on the two datasets. The results show that our approach offers a novel and reliable PSSM-based tool for prediction of apoptosis protein subcellular localization. Copyright © 2016 Elsevier Inc. All rights reserved.

BIGH3 protein and macrophages in retinal endothelial cell apoptosis.

Science.gov (United States)

Mondragon, Albert A; Betts-Obregon, Brandi S; Moritz, Robert J; Parvathaneni, Kalpana; Navarro, Mary M; Kim, Hong Seok; Lee, Chi Fung; LeBaron, Richard G; Asmis, Reto; Tsin, Andrew T

2015-01-01

Diabetes is a pandemic disease with a higher occurrence in minority populations. The molecular mechanism to initiate diabetes-associated retinal angiogenesis remains largely unknown. We propose an inflammatory pathway of diabetic retinopathy in which macrophages in the diabetic eye provide TGFβ to retinal endothelial cells (REC) in the retinal microvasculature. In response to TGFβ, REC synthesize and secrete a pro-apoptotic BIGH3 (TGFβ-Induced Gene Human Clone 3) protein, which acts in an autocrine loop to induce REC apoptosis. Rhesus monkey retinal endothelial cells (RhREC) were treated with dMCM (cell media of macrophages treated with high glucose and LDL) and assayed for apoptosis (TUNEL), BIGH3 mRNA (qPCR), and protein (Western blots) expressions. Cells were also treated with ΤGFβ1 and 2 for BIGH3 mRNA and protein expression. Inhibition assays were carried out using antibodies for TGFβ1 and for BIGH3 to block apoptosis and mRNA expression. BIGH3 in cultured RhREC cells were identified by immunohistochemistry (IHC). Distribution of BIGH3 and macrophages in the diabetic mouse retina was examined with IHC. RhRECs treated with dMCM or TGFβ showed a significant increase in apoptosis and BIGH3 protein expression. Recombinant BIGH3 added to RhREC culture medium led to a dose-dependent increase in apoptosis. Antibodies (Ab) directed against BIGH3 and TGFβ, as well as TGFβ receptor blocker resulted in a significant reduction in apoptosis induced by either dMCM, TGFβ or BIGH3. IHC showed that cultured RhREC constitutively expressed BIGH3. Macrophage and BIGH3 protein were co-localized to the inner retina of the diabetic mouse eye. Our results support a novel inflammatory pathway for diabetic retinopathy. This pathway is initiated by TGFβ released from macrophages, which promotes synthesis and release of BIGH3 protein by REC and REC apoptosis.

Interdependence of Bad and Puma during ionizing-radiation-induced apoptosis.

Science.gov (United States)

Toruno, Cristhian; Carbonneau, Seth; Stewart, Rodney A; Jette, Cicely

2014-01-01

Ionizing radiation (IR)-induced DNA double-strand breaks trigger an extensive cellular signaling response that involves the coordination of hundreds of proteins to regulate DNA repair, cell cycle arrest and apoptotic pathways. The cellular outcome often depends on the level of DNA damage as well as the particular cell type. Proliferating zebrafish embryonic neurons are highly sensitive to IR-induced apoptosis, and both p53 and its transcriptional target puma are essential mediators of the response. The BH3-only protein Puma has previously been reported to activate mitochondrial apoptosis through direct interaction with the pro-apoptotic Bcl-2 family proteins Bax and Bak, thus constituting the role of an "activator" BH3-only protein. This distinguishes it from BH3-only proteins like Bad that are thought to indirectly promote apoptosis through binding to anti-apoptotic Bcl-2 family members, thereby preventing the sequestration of activator BH3-only proteins and allowing them to directly interact with and activate Bax and Bak. We have shown previously that overexpression of the BH3-only protein Bad in zebrafish embryos supports normal embryonic development but greatly sensitizes developing neurons to IR-induced apoptosis. While Bad has previously been shown to play only a minor role in promoting IR-induced apoptosis of T cells in mice, we demonstrate that Bad is essential for robust IR-induced apoptosis in zebrafish embryonic neural tissue. Moreover, we found that both p53 and Puma are required for Bad-mediated radiosensitization in vivo. Our findings show the existence of a hierarchical interdependence between Bad and Puma whereby Bad functions as an essential sensitizer and Puma as an essential activator of IR-induced mitochondrial apoptosis specifically in embryonic neural tissue.

α-blockade, apoptosis, and prostate shrinkage: how are they related?

Science.gov (United States)

Chłosta, Piotr; Drewa, Tomasz; Kaplan, Steven

2013-01-01

The α1-adrenoreceptor antagonists, such as terazosin and doxazosin, induce prostate programmed cell death (apoptosis) within prostate epithelial and stromal cells in vitro. This treatment should cause prostate volume decrease, However, this has never been observed in clinical conditions. The aim of this paper is to review the disconnect between these two processes. PubMed and DOAJ were searched for papers related to prostate, apoptosis, and stem cell death. The following key words were used: prostate, benign prostate hyperplasia, programmed cell death, apoptosis, cell death, α1-adrenoreceptor antagonist, α-blockade, prostate epithelium, prostate stroma, stem cells, progenitors, and in vitro models. We have shown how discoveries related to stem cells can influence our understanding of α-blockade treatment for BPH patients. Prostate epithelial and mesenchymal compartments have stem (progenitors) and differentiating cells. These compartments are described in relation to experimental in vitro and in vivo settings. Apoptosis is observed within prostate tissue, but this effect has no clinical significance and cannot lead to prostate shrinkage. In part, this is due to stem cells that are responsible for prostate tissue regeneration and are resistant to apoptosis triggered by α1-receptor antagonists.

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.

Enhanced 15-HPETE production during oxidant stress induces apoptosis of endothelial cells.

Science.gov (United States)

Sordillo, Lorraine M; Weaver, James A; Cao, Yu-Zhang; Corl, Chris; Sylte, Matt J; Mullarky, Isis K

2005-05-01

Oxidant stress plays an important role in the etiology of vascular diseases by increasing rates of endothelial cell apoptosis, but few data exist on the mechanisms involved. Using a unique model of oxidative stress based on selenium deficiency (-Se), the effects of altered eicosanoid production on bovine aortic endothelial cells (BAEC) apoptosis was evaluated. Oxidant stress significantly increased the immediate oxygenation product of arachidonic acid metabolized by the 15-lipoxygenase pathway, 15-hydroxyperoxyeicosatetraenoic acid (15-HPETE). Treatment of -Se BAEC with TNFalpha/cyclohexamide (CHX) exhibited elevated levels of apoptosis, which was significantly reduced by the addition of a specific 15-lipoxygenase inhibitor PD146176. Furthermore, the addition of 15-HPETE to PD146176-treated BAEC, partially restored TNF/CHX-induced apoptosis. Increased exposure to 15-HPETE induced apoptosis, as determined by internucleosomal DNA fragmentation, chromatin condensation, caspase-3 activation, and caspase-9 activation, which suggests mitochondrial dysfunction. The expression of Bcl-2 protein also was decreased in -Se BAEC. Addition of a caspase-9 inhibitor (LEHD-fmk) completely blocked 15-HPETE-induced chromatin condensation in -Se BAEC, suggesting that 15-HPETE-induced apoptosis is caspase-9 dependent. Increased apoptosis of BAEC as a result of oxidant stress and subsequent production of 15-HPETE may play a critical role in a variety of inflammatory based diseases.

Leukocyte apoptosis as a predictor of radiosensitivity in Fanconi anemia

International Nuclear Information System (INIS)

Petrovic, Sandra; Leskovac, Andreja; Joksic, Ivana; Filipovic, Jelena; Joksic, Gordana; Vujic, Dragana; Guc-Scekic, Marija

2013-01-01

Fanconi anemia (FA) is a rare cancer-prone genetic disease characterized by impaired oxygen metabolism and defects in DNA damage repair. Response of FA cells to ionizing radiation has been an issue intensively debated in the literature. To study in vitro radiosensitivity in patients suffering from FA and their parents (heterozygous carriers), we determined radiation-induced leukocyte apoptosis using flow cytometry. As TP53 gene is involved in the control of apoptosis, we studied its status in FA lymphocytes using dual colour fluorescence in situ hybridization (FISH). FA patients and female heterozygous carriers display radiosensitive response to ionizing radiation seen as abnormal elimination of cells via apoptosis. By employment of FISH, the TP53 allele loss in FA lymphocytes was not observed. In diseases related to oxidative stress, determination of radiation-induced apoptosis is the method of choice for testing the radiosensitivity. (author)

Apoptosis in the human periodontal membrane evaluated in primary and permanent teeth

DEFF Research Database (Denmark)

Bille, Marie-Louise Bastholm; Thomsen, Bjarke; Kjær, Inger

2011-01-01

that resorption is connected to apoptosis of the epithelial cells of Malassez. The purpose of this study is to localize cells undergoing apoptosis in the periodontal membrane of human primary and permanent teeth. Materials and methods. Human primary and permanent teeth were examined immunohistochemically...... for apoptosis and epithelial cells of Malassez in the periodontal membrane. All teeth examined were extracted in connection with treatment. Results. Apoptosis was seen in close proximity to the root surface and within the epithelial cells of Malassez. This pattern of apoptotis is similar in the periodontal...... membrane in primary and permanent teeth. Conclusions. The inter-relationship between apoptotis and root resorption cannot be concluded from the present study. Apoptosis seen in close proximity to the root surface presumably corresponds to the highly innervated layer of the periodontal membrane...

Evolution of apoptosis-like programmed cell death in unicellular protozoan parasites.

Science.gov (United States)

Kaczanowski, Szymon; Sajid, Mohammed; Reece, Sarah E

2011-03-25

Apoptosis-like programmed cell death (PCD) has recently been described in multiple taxa of unicellular protists, including the protozoan parasites Plasmodium, Trypanosoma and Leishmania. Apoptosis-like PCD in protozoan parasites shares a number of morphological features with programmed cell death in multicellular organisms. However, both the evolutionary explanations and mechanisms involved in parasite PCD are poorly understood. Explaining why unicellular organisms appear to undergo 'suicide' is a challenge for evolutionary biology and uncovering death executors and pathways is a challenge for molecular and cell biology. Bioinformatics has the potential to integrate these approaches by revealing homologies in the PCD machinery of diverse taxa and evaluating their evolutionary trajectories. As the molecular mechanisms of apoptosis in model organisms are well characterised, and recent data suggest similar mechanisms operate in protozoan parasites, key questions can now be addressed. These questions include: which elements of apoptosis machinery appear to be shared between protozoan parasites and multicellular taxa and, have these mechanisms arisen through convergent or divergent evolution? We use bioinformatics to address these questions and our analyses suggest that apoptosis mechanisms in protozoan parasites and other taxa have diverged during their evolution, that some apoptosis factors are shared across taxa whilst others have been replaced by proteins with similar biochemical activities.

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.

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.

The effects of cysteamine on the radiation-induced apoptosis

International Nuclear Information System (INIS)

Choi, Young Min; Cho, Heung Lae; Park, Chang Gyo; Lee, Hyung Sik; Hur, Won Joo

2000-01-01

To investigate the pathways of radiation induced apoptosis and the effect of cysteamine (β-mercaptoethylamine), as a radioprotector, on it. HL-60 cells were assigned to control, irradiated, and cysteamine (1 mM, 10 mM) pretreated groups. Irradiation was given in a single fraction of 10 Gy (6 MV x-ray) and cysteamine was administered 1 hour before irradiation. The activities of caspase-8 were measured in control and irradiated group to evaiuate its relation to the radiation induced apoptosis. To evaluate the role of cysteamine in radiation induced apoptosis, the number of viable cells, the expression and activity or caspase-3, and the expression of poly (ADP-ribose) polymerase (PARP) were measured and compared after irradiating the HL cells with cysteamine pretreatment or not. The intracellular caspase-8 activity, known to be related to the death receptor induced apoptosis, was not affected by irradiation( p>0.05). The number of viable cells began to decrease from 6 hours after irradiation (p>0.05), but the number of viable cells in 1 mM cysteamine pretreated group was not decreased after irradiation and was similar to those in the control group. In caspase-3 analyses, known as apoptosis executioner, its expression was not different but its activity was increased by irradialion(p>0.05). However, this increase of activity was suppressed by the pretreatment of 1 mM cysteamine. The cleavage of PARP, thought to be resulted from caspase-3 activation, occurred, after irradiation, which was attenuated by the pretreatment of 1 mM cysteamine. These results show that radiation induced apoptotic process is somewhat different from death receptor induced one and the pretreatment of 1 mM cysteamine has a tendency to decrease the radiation-induced apoptosis in HL-60 cells

Broad targeting of resistance to apoptosis in cancer

Science.gov (United States)

Mohammad, Ramzi M.; Muqbil, Irfana; Lowe, Leroy; Yedjou, Clement; Hsu, Hsue-Yin; Lin, Liang-Tzung; Siegelin, Markus David; Fimognari, Carmela; Kumar, Nagi B.; Dou, Q. Ping; Yang, Huanjie; Samadi, Abbas K.; Russo, Gian Luigi; Spagnuolo, Carmela; Ray, Swapan K.; Chakrabarti, Mrinmay; Morre, James D.; Coley, Helen M.; Honoki, Kanya; Fujii, Hiromasa; Georgakilas, Alexandros G.; Amedei, Amedeo; Niccolai, Elena; Amin, Amr; Ashraf, S. Salman; Helferich, William G.; Yang, Xujuan; Boosani, Chandra S.; Guha, Gunjan; Bhakta, Dipita; Ciriolo, Maria Rosa; Aquilano, Katia; Chen, Sophie; Mohammed, Sulma I.; Keith, W. Nicol; Bilsland, Alan; Halicka, Dorota; Nowsheen, Somaira; Azmi, Asfar S.

2015-01-01

Apoptosis or programmed cell death is natural way of removing aged cells from the body. Most of the anti-cancer therapies trigger apoptosis induction and related cell death networks to eliminate malignant cells. However, in cancer, de-regulated apoptotic signaling, particularly the activation of an anti-apoptotic systems, allows cancer cells to escape this program leading to uncontrolled proliferation resulting in tumor survival, therapeutic resistance and recurrence of cancer. This resistance is a complicated phenomenon that emanates from the interactions of various molecules and signaling pathways. In this comprehensive review we discuss the various factors contributing to apoptosis resistance in cancers. The key resistance targets that are discussed include (1) Bcl-2 and Mcl-1 proteins; (2) autophagy processes; (3) necrosis and necroptosis; (4) heat shock protein signaling; (5) the proteasome pathway; (6) epigenetic mechanisms; and (7) aberrant nuclear export signaling. The shortcomings of current therapeutic modalities are highlighted and a broad spectrum strategy using approaches including (a) gossypol; (b) epigallocatechin-3-gallate; (c) UMI-77 (d) triptolide and (e) selinexor that can be used to overcome cell death resistance is presented. This review provides a roadmap for the design of successful anti-cancer strategies that overcome resistance to apoptosis for better therapeutic outcome in patients with cancer. PMID:25936818

Real-Time Imaging of Retinal Ganglion Cell Apoptosis

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Timothy E. Yap

2018-06-01

Full Text Available Monitoring real-time apoptosis in-vivo is an unmet need of neurodegeneration science, both in clinical and research settings. For patients, earlier diagnosis before the onset of symptoms provides a window of time in which to instigate treatment. For researchers, being able to objectively monitor the rates of underlying degenerative processes at a cellular level provides a biomarker with which to test novel therapeutics. The DARC (Detection of Apoptosing Retinal Cells project has developed a minimally invasive method using fluorescent annexin A5 to detect rates of apoptosis in retinal ganglion cells, the key pathological process in glaucoma. Numerous animal studies have used DARC to show efficacy of novel, pressure-independent treatment strategies in models of glaucoma and other conditions where retinal apoptosis is reported, including Alzheimer’s disease. This may forge exciting new links in the clinical science of treating both cognitive and visual decline. Human trials are now underway, successfully demonstrating the safety and efficacy of the technique to differentiate patients with progressive neurodegeneration from healthy individuals. We review the current perspectives on retinal ganglion cell apoptosis, the way in which this can be imaged, and the exciting advantages that these future methods hold in store.

The dual role of autophagy under hypoxia-involvement of interaction between autophagy and apoptosis.

Science.gov (United States)

Li, Mengmeng; Tan, Jin; Miao, Yuyang; Lei, Ping; Zhang, Qiang

2015-06-01

Hypoxia is one of severe cellular stress and it is well known to be associated with a worse outcome since a lack of oxygen accelerates the induction of apoptosis. Autophagy, an important and evolutionarily conserved mechanism for maintaining cellular homeostasis, is closely related to the apoptosis caused by hypoxia. Generally autophagy blocks the induction of apoptosis and inhibits the activation of apoptosis-associated caspase which could reduce cellular injury. However, in special cases, autophagy or autophagy-relevant proteins may help to induce apoptosis, which could aggravate cell damage under hypoxia condition. In addition, the activation of apoptosis-related proteins-caspase can also degrade autophagy-related proteins, such as Atg3, Atg4, Beclin1 protein, inhibiting autophagy. Although the relationship between autophagy and apoptosis has been known for rather complex for more than a decade, the underlying regulatory mechanisms have not been clearly understood. This short review discusses and summarizes the dual role of autophagy and the interaction and molecular regulatory mechanisms between autophagy and apoptosis under hypoxia.

O-GlcNAcylation regulates ischemia-induced neuronal apoptosis through AKT signaling

OpenAIRE

Shi, Jianhua; Gu, Jin-hua; Dai, Chun-ling; Gu, Jianlan; Jin, Xiaoxia; Sun, Jianming; Iqbal, Khalid; Liu, Fei; Gong, Cheng-Xin

2015-01-01

Apoptosis plays an important role in neural development and neurological disorders. In this study, we found that O-GlcNAcylation, a unique protein posttranslational modification with O-linked β-N-acetylglucosamine (GlcNAc), promoted apoptosis through attenuating phosphorylation/activation of AKT and Bad. By using co-immunoprecipitation and mutagenesis techniques, we identified O-GlcNAc modification at both Thr308 and Ser473 of AKT. O-GlcNAcylation-induced apoptosis was attenuated by over-expr...

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

Phenylephrine protects autotransplanted rabbit submandibular gland from apoptosis

International Nuclear Information System (INIS)

Xiang Bin; Zhang Yan; Li Yuming; Gao Yan; Gan Yehua; Wu Liling; Yu Guangyan

2008-01-01

Submandibular gland (SMG) autotransplantation is an effective treatment for severe keratoconjunctivitis sicca. Our previous studies have shown that phenylephrine attenuates structural injury and promotes cell proliferation in autotransplanted rabbit SMG. However, the mechanism by which phenylephrine reduces the injury has not been fully evaluated. In this study, we investigate the ability of phenylephrine to inhibit apoptosis in autotransplanted rabbit SMG. We observed that apoptosis occurred in the early phase of SMG transplantation and that phenylephrine treatment protected transplanted SMG from apoptosis. Furthermore, we found that phenylephrine could significantly upregulate the expression of Bcl-2, downregulate the expression of Bax, and inhibit the activation of both caspase-3 and p38 mitogen-activated protein kinase in autotransplanted SMG. Therefore, the cytoprotective effects of phenylephrine on autotransplanted SMG may be a novel clinical strategy for autotransplanted SMG protection during the early postoperative stage of transplantation

Intracoronary levosimendan during ischemia prevents myocardial apoptosis.

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Markus eMalmberg

2012-02-01

Full Text Available Background. Levosimendan is a calcium-sensitizing inotropic agent that prevents myocardial contractile depression following cardiac surgery. Levosimendan has also anti-apoptotic properties, but the role of this mechanism is not clear. We studied whether levosimendan prevents cardiomyocyte apoptosis and post-operative stunning after either intracoronary administration or intravenous infusion in an experimental model. Methods. Pigs (n=24 were subjected to 40 minutes of global, cardioplegic ischemia under cardiopulmonary bypass and 240 minutes of reperfusion. L-IV group received intravenous infusion of levosimendan (65 μg/kg 40 minutes before ischemia and L-IC group received levosimendan (65 μg/kg during ischemia administered intracoronary. Control group was operated without levosimendan. Echocardiography was performed to all animals. Apoptosis was determined from transmyocardial biopsies taken from left ventricle using TUNEL assay and immunohistochemistry of active caspace-3. Results. Apoptosis was induced after ischemia-reperfusion in all groups (pre L-IV 0.002±0.004 % vs. post L-IV 0.020±0.017 % p=0.02, pre L-IC 0.001±0.004 % vs. post L-IC 0.020±0.017 % p<0.001, pre control 0.007±0.013 % vs. post control 0.062±0.044 % p=0.01. The amount of apoptosis was higher in the controls, compared with the L-IV (p=0.03 and the L-IC (p=0.03 groups. Longitudinal left ventricular contraction was significantly reduced in the L-IC and the control groups when compared to the L-IV group (L-IV 0.75±0.12 mm vs. L-IC 0.53±0.11 mm p=0.003, L-IV vs. control 0.54±0.11 p=0.01. Conclusions. Both intracoronary administration and pre-ischemic intravenous infusion of levosimendan equally prevented apoptosis, but intravenous administration was required for optimal preservation of the post-operative systolic left ventricle function.

Cyclic GMP protects human macrophages against peroxynitrite-induced apoptosis.

Science.gov (United States)

Shaw, Catherine A; Webb, David J; Rossi, Adriano G; Megson, Ian L

2009-05-07

Nitric oxide (NO) can be both pro- and anti-apoptotic in various cell types, including macrophages. This apparent paradox may result from the actions of NO-related species generated in the microenvironment of the cell, for example the formation of peroxynitrite (ONOO-). In this study we have examined the ability of NO and ONOO- to evoke apoptosis in human monocyte-derived macrophages (MDMvarphi), and investigated whether preconditioning by cyclic guanosine monophosphate (cGMP) is able to limit apoptosis in this cell type. Characterisation of the NO-related species generated by (Z)-1- [2-(2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1-ium-1,2-diolate (DETA/NO) and 1,2,3,4-oxatriazolium, 5-amino-3-(3,4-dichlorophenyl)-, chloride (GEA-3162) was performed by electrochemistry using an isolated NO electrode and electron paramagnetic resonance (EPR) spectrometry. Mononuclear cells were isolated from peripheral blood of healthy volunteers and cultured to allow differentiation into MDMvarphi. Resultant MDMvarphi were treated for 24 h with DETA/NO (100 - 1000 muM) or GEA-3162 (10 - 300 muM) in the presence or absence of BAY 41-2272 (1 muM), isobutylmethylxanthine (IBMX; 1 muM), 1H- [1,2,4]oxadiazolo [4,3-a]quinoxalin-1-one (ODQ; 20 muM) or 8-bromo-cGMP (1 mM). Apoptosis in MDMvarphi was assessed by flow cytometric analysis of annexin V binding in combination with propidium iodide staining. Electrochemistry and EPR revealed that DETA/NO liberated free NO radical, whilst GEA-3162 concomitantly released NO and O2-, and is therefore a ONOO- generator. NO (DETA/NO) had no effect on cell viability, but ONOO- (GEA-3162) caused a concentration-dependent induction of apoptosis in MDMvarphi. Preconditioning of MDMvarphi with NO in combination with the phosphodiesterase inhibitor, 3-Isobutyl-1-methylxanthine (IBMX), or the NO-independent stimulator of soluble guanylate cyclase, BAY 41-2272, significantly attenuated ONOO--induced apoptosis in a cGMP-dependent manner. These results

Cyclic GMP protects human macrophages against peroxynitrite-induced apoptosis

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Rossi Adriano G

2009-05-01

Full Text Available Abstract Background Nitric oxide (NO can be both pro- and anti-apoptotic in various cell types, including macrophages. This apparent paradox may result from the actions of NO-related species generated in the microenvironment of the cell, for example the formation of peroxynitrite (ONOO-. In this study we have examined the ability of NO and ONOO- to evoke apoptosis in human monocyte-derived macrophages (MDMϕ, and investigated whether preconditioning by cyclic guanosine monophosphate (cGMP is able to limit apoptosis in this cell type. Methods Characterisation of the NO-related species generated by (Z-1- [2-(2-aminoethyl-N-(2-ammonioethylamino]diazen-1-ium-1,2-diolate (DETA/NO and 1,2,3,4-oxatriazolium, 5-amino-3-(3,4-dichlorophenyl-, chloride (GEA-3162 was performed by electrochemistry using an isolated NO electrode and electron paramagnetic resonance (EPR spectrometry. Mononuclear cells were isolated from peripheral blood of healthy volunteers and cultured to allow differentiation into MDMϕ. Resultant MDMϕ were treated for 24 h with DETA/NO (100 – 1000 μM or GEA-3162 (10 – 300 μM in the presence or absence of BAY 41–2272 (1 μM, isobutylmethylxanthine (IBMX; 1 μM, 1H- [1,2,4]oxadiazolo [4,3-a]quinoxalin-1-one (ODQ; 20 μM or 8-bromo-cGMP (1 mM. Apoptosis in MDMϕ was assessed by flow cytometric analysis of annexin V binding in combination with propidium iodide staining. Results Electrochemistry and EPR revealed that DETA/NO liberated free NO radical, whilst GEA-3162 concomitantly released NO and O2-, and is therefore a ONOO- generator. NO (DETA/NO had no effect on cell viability, but ONOO- (GEA-3162 caused a concentration-dependent induction of apoptosis in MDMϕ. Preconditioning of MDMϕ with NO in combination with the phosphodiesterase inhibitor, 3-Isobutyl-1-methylxanthine (IBMX, or the NO-independent stimulator of soluble guanylate cyclase, BAY 41–2272, significantly attenuated ONOO--induced apoptosis in a cGMP-dependent manner

Susceptibility of different subsets of immature thymocytes to apoptosis induced by anti-TCRmAb

International Nuclear Information System (INIS)

Li Hongmei; Zhong Renqian; Yu Jiaping; Kong Xiantao; Chen Weifeng

2003-01-01

To analysis the susceptibility of different subsets of immature mice thymocytes to apoptosis induced by anti-TCRmAbs in vitro apoptosis was induced in unfractionated mice thymocytes by anti-TCRmAb. In Vivo apoptosis was induced in BALB/c mice by anti-TCR mAb, and thymocytes were examined by FACS. Results showed that CD4 + CD8 + DP thymocytes and CD4 - CD8 + CD3 - thymocytes were equally sensitive to apoptosis after treatment with the anti-TCR mAb. In sharp contrast, the early migrants or precursor containing thymocytes which are CD4 - CD8 - CD3 - TN have a lower spontaneous apoptosis rate and were relatively resistant to the anti-TCR mAb. The findings showed a breakpoint in thymocyte sensitivity to apoptosis which occurs after the onset of CD4 - CD8 + CD3 expression, suggesting that susceptibility of thymocytes to apoptosis is developmentally regulated

Studying arsenic trioxide-induced apoptosis of Colo-16 cells with ...

African Journals Online (AJOL)

Jane

2011-10-05

Oct 5, 2011 ... induced apoptosis at the single cell level. Key words: Two-photon laser scanning microscopy, confocal laser scanning microscopy, human skin squamous carcinoma cells (Colo-16 cells), arsenic trioxide, apoptosis. INTRODUCTION. Although arsenic is poisonous and chronic arsenic exposure from ...

Current applications of nanotechnology for magnetic resonance imaging of apoptosis

NARCIS (Netherlands)

Strijkers, Gustav J.; van Tilborg, Geralda A. F.; Geelen, Tessa; Reutelingsperger, Chris P. M.; Nicolay, Klaas

2010-01-01

Apoptosis, or programmed cell death, is a morphologically and biochemically distinct form of cell death, which together with proliferation plays an important role in tissue development and homeostasis. Insufficient apoptosis is important in the pathology of various disorders such as cancer and

The role of hypoxia inducible factor 1 (HIF-1) in hypoxia induced apoptosis

NARCIS (Netherlands)

Greijer, A.E.; Wall, E. van der

2004-01-01

Apoptosis can be induced in response to hypoxia. The severity of hypoxia determines whether cells become apoptotic or adapt to hypoxia and survive. A hypoxic environment devoid of nutrients prevents the cell undergoing energy dependent apoptosis and cells become necrotic. Apoptosis regulatory

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

Science.gov (United States)

Ueda, Norishi

2015-01-01

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

Co-Operation Between FADD and Bin1 in Prostate Cancer Apoptosis

National Research Council Canada - National Science Library

Thorburn, Andrew

2004-01-01

Evasion of apoptosis is a hallmark of cancer (Hanahan and Weinberg, 2000). Consequently, it is sometimes thought that cancer cells are generally resistant to apoptosis while normal cells are sensitive...

Osteoblasts Protect AML Cells from SDF-1-Induced Apoptosis

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

2014-01-01

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

Alcohol and Apoptosis: Friends or Foes?

Science.gov (United States)

Rodriguez, Ana; Chawla, Karan; Umoh, Nsini A; Cousins, Valerie M; Ketegou, Assama; Reddy, Madhumati G; AlRubaiee, Mustafa; Haddad, Georges E; Burke, Mark W

2015-11-19

Alcohol abuse causes 79,000 deaths stemming from severe organ damage in the United States every year. Clinical manifestations of long-term alcohol abuse on the cardiac muscle include defective contractility with the development of dilated cardiomyopathy and low-output heart failure; which has poor prognosis with less than 25% survival for more than three years. In contrast, low alcohol consumption has been associated with reduced risk of cardiovascular disease, however the mechanism of this phenomenon remains elusive. The aim of this study was to determine the significance of apoptosis as a mediating factor in cardiac function following chronic high alcohol versus low alcohol exposure. Adult rats were provided 5 mM (low alcohol), 100 mM (high alcohol) or pair-fed non-alcohol controls for 4-5 months. The hearts were dissected, sectioned and stained with cresyl violet or immunohistochemically for caspase-3, a putative marker for apoptosis. Cardiomyocytes were isolated to determine the effects of alcohol exposure on cell contraction and relaxation. High alcohol animals displayed a marked thinning of the left ventricular wall combined with elevated caspase-3 activity and decreased contractility. In contrast, low alcohol was associated with increased contractility and decreased apoptosis suggesting an overall protective mechanism induced by low levels of alcohol exposure.

Membranes as sensitive targets in thymocyte apoptosis

International Nuclear Information System (INIS)

Ramakrishnan, N.; McClain, D.E.; Catravas, G.N.

1993-01-01

The role of cellular membranes in thymocyte apoptosis has been examined. Trolox, a water soluble analogue of vitamin E and inhibitor of membrane damage, inhibits DNA fragmentation in thymocytes exposed to γ-radiation, and is most effective in inhibiting DNA fragmentation when added to cells within 30 min post-irradiation. Exposure to trolox only during irradiation did not prevent DNA fragmentation. Incubation of the irradiated cell suspension with trolox for 2h post-irradiation was sufficient to prevent DNA fragmentation measured at 24 h in irradiated cells, suggesting that trolox irreversibly inhibits a cellular lesion required for apoptosis. The induction of DNA fragmentation appears to be related to a concurrent, pronounced flow of Ca 2+ into the cell. At 3 h post-irradiation the amount of Ca 2+ in irradiated thymocytes was more than twice that of unirradiated thymocytes. Trolox treatment completely blocked the radiation-induced influx of Ca 2+ into the thymocytes. These results suggest that membrane damage is a critical lesion involved in DNA fragmentation in thymocyte apoptosis. (author)

Apoptosis induced by cold shock in vitro is dependent on cell growth phase.

Science.gov (United States)

Soloff, B L; Nagle, W A; Moss, A J; Henle, K J; Crawford, J T

1987-06-15

Chinese hamster V79 fibroblast cells were exposed to brief periods of cold but non-freezing temperatures at different points on the population growth curve. Upon rewarming, cells at the transition from logarithmic to stationary growth exhibited apoptosis (programmed cell death). Cells in other stages of growth, or after reentry into logarithmic growth by refeeding, did not exhibit apoptosis. Apoptosis was expressed by marked cytoplasmic blebbing, by a characteristic non-random fragmentation of DNA into nucleosomal-sized pieces, and by loss of colony-forming ability. The data suggest that cold shock served as a stimulus for susceptible cells to undergo apoptosis. Thus, the experiments describe a new in vitro system for studying the mechanisms of apoptosis.

Host-pathogen interactions during apoptosis

Indian Academy of Sciences (India)

Unknown

349. Keywords. Antioxidant; baculovirus; host-pathogen; eIF2α-kinase; P35; PKR .... conferring a selective advantage to the virus, the capacity to prevent apoptosis is ..... totic extracts were found to cleave purified PKR in vitro. These findings ...

Noxa/Mcl-1 Balance Regulates Susceptibility of Cells to Camptothecin-Induced Apoptosis1

Science.gov (United States)

Mei, Yide; Xie, Chongwei; Xie, Wei; Tian, Xu; Li, Mei; Wu, Mian

2007-01-01

Although camptothecin (CPT) has been reported to induce apoptosis in various cancer cells, the molecular details of this regulation remain largely unknown. In this study, we demonstrate that BH3-only protein Noxa is upregulated during CPT-induced apoptosis, which is independent of p53. In addition, we show that phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway is responsible for Noxa's induction. Luciferase assay and cAMP response element binding protein (CREB) knockdown experiments further demonstrate that CREB is involved in the transcriptional upregulation of Noxa. Moreover, blocking Noxa expression using specific small interfering ribonucleic acid (siRNA) significantly reduces the apoptosis in response to CPT, indicating that Noxa is an essential mediator for CPT-induced apoptosis. Interestingly, antiapoptotic Mcl-1 was also upregulated through PI3K/Akt signaling pathway upon CPT treatment. Using immunoprecipitation assay, Noxa was found to interact with Mcl-1 in the presence or absence of CPT. Knockdown of Mcl-1 expression by short hairpin ribonucleic acid (shRNA) was shown to potentiate CPT-induced apoptosis. Consistently, ectopic overexpression of Mcl-1 rescued cells from apoptosis induced by CPT. Cells coexpressing Noxa and Mcl-1 at different ratio correlates well with the extent of apoptosis, suggesting that the balance between Noxa and Mcl-1 may determine the susceptibility of HeLa cells to CPT-induced apoptosis. PMID:17971907

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

OpenAIRE

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

2017-01-01

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)....

Radiation-induced apoptosis in the neonatal and adult rat spinal cord.

Science.gov (United States)

Li, Y Q; Wong, C S

2000-09-01

This study was designed to characterize radiation-induced apoptosis in the spinal cord of the neonatal and young adult rat. Spinal cords (C2-T2) of 1-, 2- and 10-week-old rats were irradiated with a single dose of 8, 18 or 22 Gy. Apoptosis was assessed histologically according to its specific morphological features or by using the TUNEL assay. Cell proliferation was assessed immunohistochemically using BrdU. Identities of cell types undergoing apoptosis were assessed using immunohistochemistry or in situ hybridization using markers for neurons, glial progenitor cells, microglia, oligodendrocytes and astrocytes. The time course of radiation-induced apoptosis in 1- or 2-week-old rat spinal cord was similar to that in the young adult rat spinal cord. A peak response was observed at about 8 h after irradiation, and the apoptosis index returned to the levels in nonirradiated spinal cords at 24 h. The neonatal rat spinal cord demonstrated increased apoptosis compared to the adult. Values for total yield of apoptosis over 24 h induced by 8 Gy in the neonatal rat spinal cord were significantly greater than that in the adult. Immunohistochemistry studies using Leu7, galactocerebroside, Rip and adenomatous polyposis coli tumor suppressor protein indicated that most apoptotic cells were cells of the oligodendroglial lineage regardless of the age of the animal. No evidence of Gfap or factor VIII-related antigen-positive apoptotic cells was observed, and there was a small number of apoptotic microglial cells (lectin-Rca1 positive) in the neonatal and adult rat spinal cord. In the neonatal but not adult rat spinal cord, about 10% of the apoptotic cells appeared to be neurons and were immunoreactive for synaptophysin. Labeling indices (LI) for BrdU in nonirradiated 1- and 2-week-old rat spinal cord were 20.0 and 16.3%, respectively, significantly greater than the LI of 1.0% in the 10-week-old rat spinal cord. At 8 h after a single dose of 8 Gy, 13.4% of the apoptotic cells were

Apoptotic cells can induce non-autonomous apoptosis through the TNF pathway

Science.gov (United States)

Pérez-Garijo, Ainhoa; Fuchs, Yaron; Steller, Hermann

2013-01-01

Apoptotic cells can produce signals to instruct cells in their local environment, including ones that stimulate engulfment and proliferation. We identified a novel mode of communication by which apoptotic cells induce additional apoptosis in the same tissue. Strong induction of apoptosis in one compartment of the Drosophila wing disc causes apoptosis of cells in the other compartment, indicating that dying cells can release long-range death factors. We identified Eiger, the Drosophila tumor necrosis factor (TNF) homolog, as the signal responsible for apoptosis-induced apoptosis (AiA). Eiger is produced in apoptotic cells and, through activation of the c-Jun N-terminal kinase (JNK) pathway, is able to propagate the initial apoptotic stimulus. We also show that during coordinated cell death of hair follicle cells in mice, TNF-α is expressed in apoptotic cells and is required for normal cell death. AiA provides a mechanism to explain cohort behavior of dying cells that is seen both in normal development and under pathological conditions. DOI: http://dx.doi.org/10.7554/eLife.01004.001 PMID:24066226

Mechanisms of Neuronal Apoptosis In Vivo

National Research Council Canada - National Science Library

Martin, Lee J

2004-01-01

.... Neuronal cell death in the form of apoptosis or necrosis occurs after exposure to neurotoxins, chemical warfare agents, radiation, viruses, and after seizures, trauma, limb amputation, and hypoxic...

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

The Role of Apoptosis Associated Markers in Pathogenesis of Pulmonary Tuberculosis

Science.gov (United States)

2012-08-28

To Compare the Serum Apoptosis-associated Markers Between Patients With Active TB and Patients With LTBI; To Evaluate the Efficiency of Apoptosis-associated Markers to Differentiate Potential of Active TB From LTBI

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

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.

Restraining reactive oxygen species in Listeria monocytogenes promotes the apoptosis of glial cells.

Science.gov (United States)

Li, Sen; Li, Yixuan; Chen, Guowei; Zhang, Jingchen; Xu, Fei; Wu, Man

2017-07-01

Listeria monocytogenes is a facultative anaerobic foodborne pathogen that can traverse the blood-brain barrier and cause brain infection. L. monocytogenes infection induces host cell apoptosis in several cell types. In this study, we investigated the apoptosis of human glioma cell line U251 invaded by L. monocytogenes and evaluated the function of bacterial reactive oxygen species (ROS) during infection. Bacterial ROS level was reduced by carrying out treatment with N-acetyl cysteine (NAC) and diphenyleneiodonium chloride (DPI). After infection, the apoptosis of U251 cells was examined by flow cytometry assay and propidium iodide staining. DPI and NAC efficiently decreased ROS level in L. monocytogenes without affecting bacterial growth. Moreover, the apoptosis of glial cells was enhanced upon invasion of DPI- and NAC-pretreated L. monocytogenes. Results indicate that the apoptosis of glial cells can be induced by L. monocytogenes, and that the inhibition of bacterial ROS increases the apoptosis of host cells.

Identifying Novel Candidate Genes Related to Apoptosis from a Protein-Protein Interaction Network

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Baoman Wang

2015-01-01

Full Text Available Apoptosis is the process of programmed cell death (PCD that occurs in multicellular organisms. This process of normal cell death is required to maintain the balance of homeostasis. In addition, some diseases, such as obesity, cancer, and neurodegenerative diseases, can be cured through apoptosis, which produces few side effects. An effective comprehension of the mechanisms underlying apoptosis will be helpful to prevent and treat some diseases. The identification of genes related to apoptosis is essential to uncover its underlying mechanisms. In this study, a computational method was proposed to identify novel candidate genes related to apoptosis. First, protein-protein interaction information was used to construct a weighted graph. Second, a shortest path algorithm was applied to the graph to search for new candidate genes. Finally, the obtained genes were filtered by a permutation test. As a result, 26 genes were obtained, and we discuss their likelihood of being novel apoptosis-related genes by collecting evidence from published literature.

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

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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.

CD36 Mediated Fatty Acid-Induced Podocyte Apoptosis via Oxidative Stress.

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Wei Hua

Full Text Available Hyperlipidemia-induced apoptosis mediated by fatty acid translocase CD36 is associated with increased uptake of ox-LDL or fatty acid in macrophages, hepatocytes and proximal tubular epithelial cells, leading to atherosclerosis, liver damage and fibrosis in obese patients, and diabetic nephropathy (DN, respectively. However, the specific role of CD36 in podocyte apoptosis in DN with hyperlipidemia remains poorly investigated.The expression of CD36 was measured in paraffin-embedded kidney tissue samples (Ctr = 18, DN = 20 by immunohistochemistry and immunofluorescence staining. We cultured conditionally immortalized mouse podocytes (MPC5 and treated cells with palmitic acid, and measured CD36 expression by real-time PCR, Western blot analysis and immunofluorescence; lipid uptake by Oil red O staining and BODIPY staining; apoptosis by flow cytometry assay, TUNEL assay and Western blot analysis; and ROS production by DCFH-DA fluorescence staining. All statistical analyses were performed using SPSS 21.0 statistical software.CD36 expression was increased in kidney tissue from DN patients with hyperlipidemia. Palmitic acid upregulated CD36 expression and promoted its translocation from cytoplasm to plasma membrane in podocytes. Furthermore, palmitic acid increased lipid uptake, ROS production and apoptosis in podocytes, Sulfo-N-succinimidyloleate (SSO, the specific inhibitor of the fatty acid binding site on CD36, decreased palmitic acid-induced fatty acid accumulation, ROS production, and apoptosis in podocytes. Antioxidant 4-hydroxy-2,2,6,6- tetramethylpiperidine -1-oxyl (tempol inhibited the overproduction of ROS and apoptosis in podocytes induced by palmitic acid.CD36 mediated fatty acid-induced podocyte apoptosis via oxidative stress might participate in the process of DN.

Feedback regulation of mitochondria by caspase-9 in the B cell receptor-mediated apoptosis.

Science.gov (United States)

Eeva, J; Nuutinen, U; Ropponen, A; Mättö, M; Eray, M; Pellinen, R; Wahlfors, J; Pelkonen, J

2009-12-01

During the germinal centre reaction (GC), B cells with non-functional or self-reactive antigen receptors are negatively selected by apoptosis to generate B cell repertoire with appropriate antigen specificities. We studied the molecular mechanism of Fas/CD95- and B cell receptor (BCR)-induced apoptosis to shed light on the signalling events involved in the negative selection of GC B cells. As an experimental model, we used human follicular lymphoma (FL) cell line HF1A3, which originates from a GC B cell, and transfected HF1A3 cell lines overexpressing Bcl-x(L), c-FLIP(long) or dominant negative (DN) caspase-9. Fas-induced apoptosis was dependent on the caspase-8 activation, since the overexpression of c-FLIP(long), a natural inhibitor of caspase-8 activation, blocked apoptosis induced by Fas. In contrast, caspase-9 activation was not involved in Fas-induced apoptosis. BCR-induced apoptosis showed the typical characteristics of mitochondria-dependent (intrinsic) apoptosis. Firstly, the activation of caspase-9 was involved in BCR-induced DNA fragmentation, while caspase-8 showed only marginal role. Secondly, overexpression of Bcl-x(L) could block all apoptotic changes induced by BCR. As a novel finding, we demonstrate that caspase-9 can enhance the cytochrome-c release and collapse of mitochondrial membrane potential (DeltaPsi(m)) during BCR-induced apoptosis. The requirement of different signalling pathways in apoptosis induced by BCR and Fas may be relevant, since Fas- and BCR-induced apoptosis can thus be regulated independently, and targeted to different subsets of GC B cells.

Prenatal irradiation: radioinduced apoptosis in developing central nervous system; Irradiacion prenatal: apoptosis radioinducida en el sistema nervioso central en desarrollo

Energy Technology Data Exchange (ETDEWEB)

Gisone, P; Dubner, D; Michelin, S; Perez, M R [Autoridad Regulatoria Nuclear, Buenos Aires (Argentina); Barboza, M [Hospital de Clinicas Jose de San Martin, Buenos Aires (Argentina)

1998-07-01

Severe mental retardation (SMR) is the most significant effect of prenatal irradiation. The high radiosensitivity of developing brain is related with the chronology of morpho genetic phenomena regarding neuroblast proliferation, neuronal differentiation and migration, synaptogenesis and dendritic arborization. Programmed cell death (apoptosis) normally occurs during development in central nervous system (CNS). Apoptosis is a direct result of the expression of specific genes with a final common pathway leading to a characteristic DNA fragmentation pattern. A wide variety of situations and toxic agents have been reported to result in apoptotic death in developing CNS. The aim of this work was the characterization and quantification of apoptosis using an in vitro model of prenatal irradiation. Primary cell cultures from rat brain cortex of 17 days g.a. were irradiated with a gamma source, with doses between 0.2 Gy to 2 Gy. Apoptosis was evaluated 4 hours and 20 hours after irradiation by hematoxylin/eosin, fluorescent microscopy, flow cytometry and DNA electrophoresis. It was also evaluated the neuro protective effect of L-NAME, SOD and glutathion. A dose-dependent increase in apoptotic cell fraction was observed. A protector effect related with the presence of glutathion was observed. (author) [Spanish] Las exposiciones prenatales son motivo frecuente de consulta en el ambito de la radioproteccion. El sistema nervioso es particularmente vulnerable a la accion de la radiacion durante la vida prenatal, con un momento de maxima radiosensibilidad entre las semanas 8 y 15 de edad gestacional (e.g.), durante la cual la frecuencia de retraso mental severo es del orden del 40% por Sievert. La apoptosis, forma activa de muerte celular programada, constituye un proceso fisiologico esencial durante el desarrollo. Las alteraciones de su regulacion podrian jugar un rol en diversas patologias tales como cancer, inmunodeficiencias y enfermedades neurodegenerativas. Se estudio la

Micafungin induced apoptosis in Candida parapsilosis independent of its susceptibility to micafungin

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Fazal Shirazi

2015-10-01

Full Text Available We hypothesized that the cell wall inhibitor micafungin (MICA induces apoptosis in both MICA-susceptible (MICA-S and MICA–non-susceptible (MICA-NS Candida parapsilosis. Antifungal activity and apoptosis were analyzed in MICA-S and MICA-NS C. parapsilosis strains following exposure to micafungin for 3 h at 37°C in RPMI 1640 medium. Apoptosis was characterized by detecting phosphatidylserine externalization (PS, plasma membrane integrity, reactive oxygen species (ROS generation, mitochondrial membrane potential changes, adenosine triphosphate (ATP release, and caspase-like activity. Apoptosis was detected in MICA exposed (0.25 to 1 mg/L susceptible C. parapsilosis strains and was associated with apoptosis of 20-52% of analyzed cells versus only 5-30% of apoptosis in MICA-NS cells exposed to micafungin (0.5 to 2 mg/L; P = 0.001. The MICA antifungal activity was correlated with apoptotic cells showing increased dihydrorhodamine-123 staining (indicating ROS production, Rh-123 staining (decreased mitochondrial membrane potential, elevated ATP, and increased metacaspase activity. In conclusion, MICA is pro-apoptotic in MICA-S cells, but still exerts apoptotic effects in MICA –NS C. parapsilosis.

Melatonin Alleviates Liver Apoptosis in Bile Duct Ligation Young Rats.

Science.gov (United States)

Sheen, Jiunn-Ming; Chen, Yu-Chieh; Hsu, Mei-Hsin; Tain, You-Lin; Huang, Ying-Hsien; Tiao, Mao-Meng; Li, Shih-Wen; Huang, Li-Tung

2016-08-20

Bile duct ligation (BDL)-treated rats display cholestasis and liver damages. The potential protective activity of melatonin in young BDL rats in terms of apoptosis, mitochondrial function, and endoplasmic reticulum (ER) homeostasis has not yet been evaluated. Three groups of young male Sprague-Dawley rats were used: one group received laparotomy (Sham), a second group received BDL for two weeks (BDL), and a third group received BDL and intraperitoneal melatonin (100 mg/day) for two weeks (BDL + M). BDL group rats showed liver apoptosis, increased pro-inflamamtory mediators, caspases alterations, anti-apoptotic factors changes, and dysfunction of ER homeostasis. Melatonin effectively reversed apoptosis, mainly through intrinsic pathway and reversed ER stress. In addition, in vitro study showed melatonin exerted its effect mainly through the melatonin 2 receptor (MT2) in HepG2 cells. In conclusion, BDL in young rats caused liver apoptosis. Melatonin rescued the apoptotic changes via the intrinsic pathway, and possibly through the MT2 receptor. Melatonin also reversed ER stress induced by BDL.

Apoptosis imaging studies in various animal models using radio-iodinated peptide.

Science.gov (United States)

Kwak, Wonjung; Ha, Yeong Su; Soni, Nisarg; Lee, Woonghee; Park, Se-Il; Ahn, Heesu; An, Gwang Il; Kim, In-San; Lee, Byung-Heon; Yoo, Jeongsoo

2015-01-01

Apoptosis has a role in many medical disorders and treatments; hence, its non-invasive evaluation is one of the most riveting research topics. Currently annexin V is used as gold standard for imaging apoptosis. However, several drawbacks, including high background, slow body clearance, make it a suboptimum marker for apoptosis imaging. In this study, we radiolabeled the recently identified histone H1 targeting peptide (ApoPep-1) and evaluated its potential as a new apoptosis imaging agent in various animal models. ApoPep-1 (CQRPPR) was synthesized, and an extra tyrosine residue was added to its N-terminal end for radiolabeling. This peptide was radiolabeled with (124)I and (131)I and was tested for its serum stability. Surgery- and drug-induced apoptotic rat models were prepared for apoptosis evaluation, and PET imaging was performed. Doxorubicin was used for xenograft tumor treatment in mice, and the induced apoptosis was studied. Tumor metabolism and proliferation were assessed by [(18)F]FDG and [(18)F]FLT PET imaging and compared with ApoPep-1 after doxorubicin treatment. The peptide was radiolabeled at high purity, and it showed reasonably good stability in serum. Cell death was easily imaged by radiolabeled ApoPep-1 in an ischemia surgery model. And, liver apoptosis was more clearly identified by ApoPep-1 rather than [(124)I]annexin V in cycloheximide-treated models. Three doxorubicin doses inhibited tumor growth, which was evaluated by 30-40% decreases of [(18)F]FDG and [(18)F]FLT PET uptake in the tumor area. However, ApoPep-1 demonstrated more than 200% increase in tumor uptake after chemotherapy, while annexin V did not show any meaningful uptake in the tumor compared with the background. Biodistribution data were also in good agreement with the microPET imaging results. All of the experimental data clearly demonstrated high potential of the radiolabeled ApoPep-1 for in vivo apoptosis imaging.

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

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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

Endotoxemia-induced lymphocyte apoptosis is augmented by a hyperinsulinemic-euglycemic clamp

DEFF Research Database (Denmark)

Nielsen, Jeppe Sylvest; A, Larsson; Brix-Christensen, Vibeke

2005-01-01

BACKGROUND: Sepsis and endotoxemia are associated with lymphocyte apoptosis. This has been regarded as harmful, contributing to further immune suppression in already immune-compromised patients. Because normalization of blood glucose improves outcome in critically ill patients, the authors...... hypothesized that one of the effects of insulin and normoglycemia would be inhibition of lymphocyte apoptosis. Therefore, in this experimental study in pigs, the authors examined the separate and combined effects of acute endotoxemia and a hyperinsulinemic-euglycemic clamp (HEC) on lymphocyte apoptosis...... sections of each sample, the apoptosis of B and T lymphocytes were analyzed using stereologic methods: The number of apoptotic B and T cells was estimated by fluorescence immunohistochemistry with anti-active caspase-3 and either anti-CD21 (B lymphocytes) or anti-CD3epsilon (T lymphocytes). The number...

Epithelial apoptosis in mechanistically distinct methods of injury in the murine small intestine

Science.gov (United States)

Vyas, Dinesh; Robertson, Charles M; Stromberg, Paul E; Martin, James R.; Dunne, W. Michael; Houchen, Courtney W; Barrett, Terrence A; Ayala, Alfred; Perl, Mario; Buchman, Timothy G; Coopersmith, Craig M

2007-01-01

Gut epithelial apoptosis is involved in the pathophysiology of multiple diseases. This study characterized intestinal apoptosis in three mechanistically distinct injuries with different kinetics of cell death. FVB/N mice were subjected to gamma radiation, Pseudomonas aeruginosa pneumonia or injection of monoclonal anti-CD3 antibody and sacrificed 4, 12, or 24 hours post-injury (n=10/time point). Apoptosis was quantified in the jejunum by hematoxylin and eosin (H&E), active caspase-3, terminal deoxynucleotidyl transferase dUTP-mediated nick end labeling (TUNEL), in situ oligoligation reaction (ISOL,) cytokeratin 18, and annexin V staining. Reproducible results were obtained only for H&E, active caspase-3, TUNEL and ISOL, which were quantified and compared against each other for each injury at each time point. Kinetics of injury were different with early apoptosis highest following radiation, late apoptosis highest following anti CD3, and more consistent levels following pneumonia. ISOL was the most consistent stain and was always statistically indistinguishable from at least 2 stains. In contrast, active caspase-3 demonstrated lower levels of apoptosis, while the TUNEL assay had higher levels of apoptosis in the most severely injured intestine regardless of mechanism of injury. H&E was a statistical outlier more commonly than any other stain. This suggests that regardless of mechanism or kinetics of injury, ISOL correlates to other quantification methods of detecting gut epithelial apoptosis more than any other method studied and compares favorably to other commonly accepted techniques of quantifying apoptosis in a large intestinal cross sectional by balancing sensitivity and specificity across a range of times and levels of death. PMID:17357092

JNK1 protects against glucolipotoxicity-mediated beta-cell apoptosis

DEFF Research Database (Denmark)

Prause, Michala; Christensen, Dan Ploug; Billestrup, Nils

2014-01-01

Pancreatic β-cell dysfunction is central to type 2 diabetes pathogenesis. Prolonged elevated levels of circulating free-fatty acids and hyperglycemia, also termed glucolipotoxicity, mediate β-cell dysfunction and apoptosis associated with increased c-Jun N-terminal Kinase (JNK) activity. Endoplas......Pancreatic β-cell dysfunction is central to type 2 diabetes pathogenesis. Prolonged elevated levels of circulating free-fatty acids and hyperglycemia, also termed glucolipotoxicity, mediate β-cell dysfunction and apoptosis associated with increased c-Jun N-terminal Kinase (JNK) activity....... Endoplasmic reticulum (ER) and oxidative stress are elicited by palmitate and high glucose concentrations further potentiating JNK activity. Our aim was to determine the role of the JNK subtypes JNK1, JNK2 and JNK3 in palmitate and high glucose-induced β-cell apoptosis. We established insulin-producing INS1...... INS1 cells showed increased apoptosis and cleaved caspase 9 and 3 compared to non-sense shRNA expressing control INS1 cells when exposed to palmitate and high glucose associated with increased CHOP expression, ROS formation and Puma mRNA expression. JNK2 shRNA expressing INS1 cells did not affect...

Prenatal irradiation: radioinduced apoptosis in developing central nervous system

International Nuclear Information System (INIS)

Gisone, P.; Dubner, D.; Michelin, S.; Perez, M.R.; Barboza, M.

1998-01-01

Severe mental retardation (SMR) is the most significant effect of prenatal irradiation. The high radiosensitivity of developing brain is related with the chronology of morpho genetic phenomena regarding neuroblast proliferation, neuronal differentiation and migration, synaptogenesis and dendritic arborization. Programmed cell death (apoptosis) normally occurs during development in central nervous system (CNS). Apoptosis is a direct result of the expression of specific genes with a final common pathway leading to a characteristic DNA fragmentation pattern. A wide variety of situations and toxic agents have been reported to result in apoptotic death in developing CNS. The aim of this work was the characterization and quantification of apoptosis using an in vitro model of prenatal irradiation. Primary cell cultures from rat brain cortex of 17 days g.a. were irradiated with a gamma source, with doses between 0.2 Gy to 2 Gy. Apoptosis was evaluated 4 hours and 20 hours after irradiation by hematoxylin/eosin, fluorescent microscopy, flow cytometry and DNA electrophoresis. It was also evaluated the neuro protective effect of L-NAME, SOD and glutathion. A dose-dependent increase in apoptotic cell fraction was observed. A protector effect related with the presence of glutathion was observed. (author) [es

Effect of small dose of radiation on induction of apoptosis in murine tumors

International Nuclear Information System (INIS)

Seong, Jin Sil; Pyo, Hong Ryull; Chung, Eun Ji; Kim, Sung Hee; Suh, Chang Ok

1999-01-01

To investigate the presence of adaptive response by low dose radiation in murine tumors in relation to radiation induced apoptosis as well as related mechanism. Syngeneic murine tumors, OCa-1 and HCa-l, were given 0.05 Gy pretreatment followed by therapeutic dose of 25 Gy radiation. Induction of apoptosis was analyzed for each treatment group. Regulating molecules of apoptosis. p53, Bcl-2, Sax, Bel-X, were also analyzed by Western blotting. In 0.05 Gy pretreatment group of OCa-l, 25 Gy-induced apoptosis per 1000 cells was 229, which was estimated at 30% lower level than the expected (p<0.05). In contrast, this reduction in radiation induced apoptosis was not seen in HCa-1. In the expression of apoptosis regulating molecules, p53 increased in both tumors in response to radiation. Bcl-2 and Bax did not show significant change in both tumors however, the expression of Bcl-2 surpassed that of Bax in 0.05 Gy pretreatment group of OCa-1. Bcl-X was not expressed in OCa-1. In HCa-l, ScI-X showed increased expression even with 0.05 Gy. Adaptive response by low dose radiation is shown in one murine tumor, OCa-I, in relation to radiation induced apoptosis. Apoptosis regulating molecules including Bcl-2/Bax and Bcl-X, appear to related. This study shows an evidence that adaptive response is present, but not a generalized phenomenon in vivo

Molecular Analysis of Neurotoxin-Induced Apoptosis

National Research Council Canada - National Science Library

D'Mello, Santosh R

2006-01-01

Apoptosis is a cell-suicide process that is required for the normal development of the nervous system, but that can be aberrantly activated in neurodegenerative diseases and following exposure to neurotoxins...

Nuclear exclusion of transcription factors associated with apoptosis in developing nervous tissue

Directory of Open Access Journals (Sweden)

R. Linden

1999-07-01

Full Text Available Programmed cell death in the form of apoptosis involves a network of metabolic events and may be triggered by a variety of stimuli in distinct cells. The nervous system contains several neuron and glial cell types, and developmental events are strongly dependent on selective cell interactions. Retinal explants have been used as a model to investigate apoptosis in nervous tissue. This preparation maintains the structural complexity and cell interactions similar to the retina in situ, and contains cells in all stages of development. We review the finding of nuclear exclusion of several transcription factors during apoptosis in retinal cells. The data reviewed in this paper suggest a link between apoptosis and a failure in the nucleo-cytoplasmic partition of transcription factors. It is argued that the nuclear exclusion of transcription factors may be an integral component of apoptosis both in the nervous system and in other types of cells and tissues.

Mitofusin 2 Promotes Apoptosis of CD4+ T Cells by Inhibiting Autophagy in Sepsis

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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.

Resistance to apoptosis should not be taken as a hallmark of cancer

OpenAIRE

Rui-An Wang; Zeng-Shan Li; Qing-Guo Yan; Xiu-Wu Bian; Yan-Qing Ding; Xiang Du; Bao-Cun Sun; Yun-Tian Sun; Xiang-Hong Zhang

2014-01-01

In the research community, resistance to apoptosis is often considered a hallmark of cancer. However, pathologists who diagnose cancer via microscope often see the opposite. Indeed, increased apoptosis and mitosis are usually observed simultaneously in cancerous lesions. Studies have shown that increased apoptosis is associated with cancer aggressiveness and poor clinical outcome. Furthermore, overexpression of Bcl-2, an antiapoptotic protein, is linked with better survival of cancer patients...

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.

Molecular Imaging of Apoptosis: From Micro to Macro

Science.gov (United States)

Zeng, Wenbin; Wang, Xiaobo; Xu, Pengfei; Liu, Gang; Eden, Henry S.; Chen, Xiaoyuan

2015-01-01

Apoptosis, or programmed cell death, is involved in numerous human conditions including neurodegenerative diseases, ischemic damage, autoimmune disorders and many types of cancer, and is often confused with other types of cell death. Therefore strategies that enable visualized detection of apoptosis would be of enormous benefit in the clinic for diagnosis, patient management, and development of new therapies. In recent years, improved understanding of the apoptotic machinery and progress in imaging modalities have provided opportunities for researchers to formulate microscopic and macroscopic imaging strategies based on well-defined molecular markers and/or physiological features. Correspondingly, a large collection of apoptosis imaging probes and approaches have been documented in preclinical and clinical studies. In this review, we mainly discuss microscopic imaging assays and macroscopic imaging probes, ranging in complexity from simple attachments of reporter moieties to proteins that interact with apoptotic biomarkers, to rationally designed probes that target biochemical changes. Their clinical translation will also be our focus. PMID:25825597

Radiation-induced apoptosis in F9 teratocarcinoma cells

International Nuclear Information System (INIS)

Langley, R.E.; Palayoor, S.T.; Coleman, C.N.; Bump, E.A.

1994-01-01

We have found that F9 murine teratocarcinoma cells undergo morphological changes and internucleosomal DNA fragmentation characteristic of apoptosis after exposure to ionizing radiation. We studied the time course, radiation dose-response, and the effects of protein and RNA synthesis inhibitors on this process. The response is dose dependent in the range 2-12 Gy. Internucleosomal DNA fragmentation can be detected as early as 6 h postirradiation and is maximal by 48 h. Cycloheximide, a protein synthesis inhibitor, and 5,6-dichloro-1-β-D-ribofuranosylbenzimidazole, an RNA synthesis inhibitor, both induced internucleosomal DNA fragmentation in the unirradiated cells and enhanced radiation-induced DNA fragmentation. F9 cells can be induced to differentiate into cells resembling endoderm with retinoic acid. After irradiation, differentiated F9 cells exhibit less DNA fragmentation than stem cells. This indicates that ionizing radiation can induce apoptosis in non-lymphoid tumours. We suggest that embryonic tumour cells may be particularly susceptible to agents that induce apoptosis. (Author)

Radiation-induced apoptosis in F9 teratocarcinoma cells

Energy Technology Data Exchange (ETDEWEB)

Langley, R E; Palayoor, S T; Coleman, C N; Bump, E A [Joint Center for Radiation Therapy and Dana Farber Cancer Inst., Boston (United States)

1994-05-01

We have found that F9 murine teratocarcinoma cells undergo morphological changes and internucleosomal DNA fragmentation characteristic of apoptosis after exposure to ionizing radiation. We studied the time course, radiation dose-response, and the effects of protein and RNA synthesis inhibitors on this process. The response is dose dependent in the range 2-12 Gy. Internucleosomal DNA fragmentation can be detected as early as 6 h postirradiation and is maximal by 48 h. Cycloheximide, a protein synthesis inhibitor, and 5,6-dichloro-1-[beta]-D-ribofuranosylbenzimidazole, an RNA synthesis inhibitor, both induced internucleosomal DNA fragmentation in the unirradiated cells and enhanced radiation-induced DNA fragmentation. F9 cells can be induced to differentiate into cells resembling endoderm with retinoic acid. After irradiation, differentiated F9 cells exhibit less DNA fragmentation than stem cells. This indicates that ionizing radiation can induce apoptosis in non-lymphoid tumours. We suggest that embryonic tumour cells may be particularly susceptible to agents that induce apoptosis. (Author).

Butyrate down regulates BCL-XL and sensitizes human fibroblasts to radiation and chemotherapy induced apoptosis

International Nuclear Information System (INIS)

Chung, Diana H.; Ljungman, Mats; Zhang Fenfen; Chen Feng; McLaughlin, William P.

1997-01-01

Purpose/Objective: Butyrate is a short chain fatty acid that has been implicated in the induction of cell cycle arrest, cell differentiation and apoptosis. The purpose of this study was to determine if butyrate treatment sensitizes cells to radiation or chemotherapy induced apoptosis. Materials and Methods: Normal neonatal human diploid fibroblasts were used throughout this study. Apoptosis was scored and quantified using three different methods. First, cell morphology using propidium iodide and fluorescence microscopy was used to qualitatively determine apoptosis and to quantify the percentage of cells undergoing apoptosis. Second, apoptosis induced DNA degradation was scored by quantifying the amount of cells appearing in a sub-G1 peak using fixed and PI-stained cells and flow cytometry. Third, apoptosis-induced DNA degradation was examined by using an assay involving direct lysis of cells in the wells of agarose gels followed by conventional gel electrophoresis. Western blotting was used to quantify the cellular levels of the apoptosis regulators, Bcl-2, Bcl-XL and Bax. Results: Human diploid fibroblasts, which were resistant to radiation induced apoptosis, were found to undergo massive apoptosis when radiation was combined with butyrate treatment. Sensitization was obtained when butyrate was added before or after radiation although the combination of both pre and post-treatment was the most effective. Butyrate was also found to enhance UV light and cisplatin-induced apoptosis. These findings correlated with a reduction of the apoptosis antagonist Bcl-XL. Bcl-XL levels significantly dropped in a time and dose dependent manner. In addition, butyrate effectively blocked UV-induced accumulation of p53. Conclusion: Our results suggest that butyrate may be an attractive agent to use in combination with radiation or chemotherapy to lower the apoptotic threshold of tumor cells, regardless of the p53 status of the tumor cells

Canine distemper virus induces apoptosis in cervical tumor derived cell lines

Directory of Open Access Journals (Sweden)

Rajão Daniela S

2011-06-01

Full Text Available Abstract Apoptosis can be induced or inhibited by viral proteins, it can form part of the host defense against virus infection, or it can be a mechanism for viral spread to neighboring cells. Canine distemper virus (CDV induces apoptotic cells in lymphoid tissues and in the cerebellum of dogs naturally infected. CDV also produces a cytopathologic effect, leading to apoptosis in Vero cells in tissue culture. We tested canine distemper virus, a member of the Paramyxoviridae family, for the ability to trigger apoptosis in HeLa cells, derived from cervical cancer cells resistant to apoptosis. To study the effect of CDV infection in HeLa cells, we examined apoptotic markers 24 h post infection (pi, by flow cytometry assay for DNA fragmentation, real-time PCR assay for caspase-3 and caspase-8 mRNA expression, and by caspase-3 and -8 immunocytochemistry. Flow cytometry showed that DNA fragmentation was induced in HeLa cells infected by CDV, and immunocytochemistry revealed a significant increase in the levels of the cleaved active form of caspase-3 protein, but did not show any difference in expression of caspase-8, indicating an intrinsic apoptotic pathway. Confirming this observation, expression of caspase-3 mRNA was higher in CDV infected HeLa cells than control cells; however, there was no statistically significant change in caspase-8 mRNA expression profile. Our data suggest that canine distemper virus induced apoptosis in HeLa cells, triggering apoptosis by the intrinsic pathway, with no participation of the initiator caspase -8 from the extrinsic pathway. In conclusion, the cellular stress caused by CDV infection of HeLa cells, leading to apoptosis, can be used as a tool in future research for cervical cancer treatment and control.

Gonadal steroids modulate Fas-induced apoptosis of lactotropes and somatotropes.

Science.gov (United States)

Jaita, Gabriela; Zárate, Sandra; Ferrari, Luciana; Radl, Daniela; Ferraris, Jimena; Eijo, Guadalupe; Zaldivar, Verónica; Pisera, Daniel; Seilicovich, Adriana

2011-02-01

We have previously reported that Fas activation induces apoptosis of anterior pituitary cells from rats at proestrus but not at diestrus and in an estrogen-dependent manner. In this study, we evaluated the effect of Fas activation on apoptosis of lactotropes and somatotropes during the estrous cycle and explored the action of gonadal steroids on Fas-induced apoptosis. Also, we studied whether changes in Fas expression are involved in the apoptotic response of anterior pituitary cells. Fas activation increased the percentage of TUNEL-positive lactotropes and somatotropes at proestrus but not at diestrus. FasL triggered apoptosis of somatotropes only when cells from ovariectomized rats were cultured in the presence of 17 β-estradiol (E2). Progesterone (P4) blocked the apoptotic action of the Fas/FasL system in lactotropes and somatotropes incubated with E2. Both E2 and P4 increased the percentage of cells expressing Fas at the cell membrane. Our results show that Fas activation induces apoptosis of lactotropes and somatotropes at proestrus but not at diestrus. Gonadal steroids may be involved in the apoptotic response of lactotropes and somatotropes, suggesting that Fas activation is implicated in the renewal of these pituitary subpopulations during the estrous cycle. The effect of gonadal steroids on Fas expression may be only partially involved in regulation of the Fas/FasL apoptotic pathway in the anterior pituitary gland.

Study of progesterone mechanisms in radio-induced apoptosis prevention

International Nuclear Information System (INIS)

Vares, G.

2004-10-01

The purpose of this work was to study the modulation of radiation-induced cell death of human mammary tumoral cells by progesterone. On the one hand, we observed that progesterone protects cells against radiation-induced apoptosis and increases the proportion of surviving and proliferating damaged cells. On the other hand, a transcriptome analysis was undertaken in irradiated cells treated by progesterone, using DNA micro-arrays. This let us highlight several transcriptional dis-regulations that are likely to explain the protective effect of the hormone; in particular, we showed that progesterone regulates the expression of genes implicated in apoptosis signaling by death receptors. Knowing the crucial role of hormonal control and of apoptosis regulation in breast cancer initiation, our results may help to achieve a better understanding of the implication of progesterone in mammary carcinogenesis. (author)

Arsenic induced apoptosis in rat liver following repeated 60 days exposure

International Nuclear Information System (INIS)

Bashir, Somia; Sharma, Yukti; Irshad, M.; Nag, T.C.; Tiwari, Monica; Kabra, M.; Dogra, T.D.

2006-01-01

Background: Accumulation of the wide spread environmental toxin arsenic in liver results in hepatotoxcity. Exposure to arsenite and other arsenicals has been previously shown to induce apoptosis in certain tumor cell lines at low (1-3 μM) concentration. Aim: The present study was focused to elucidate the role of free radicals in arsenic toxicity and to investigate the nature of in vivo sodium arsenite induced cell death in liver. Methods: Male wistar rats were exposed to arsenite at three different doses of 0.05, 2.5 and 5 mg/l for 60 days. Oxidative stress in liver was measured by estimating pro-oxidant and antioxidant activity in liver. Histopathological examination of liver was carried out by light and transmission electron microscopy. Analysis of DNA fragmentation by gel electrophoresis was used to identify apoptosis after the exposure. Terminal deoxy-nucleotidyl transferase mediated dUTP Nick end-labeling (TUNEL) assay was used to qualify and quantify apoptosis. Results: A significant increase in cytochrome-P450 and lipid peroxidation accompanied with a significant alteration in the activity of many of the antioxidants was observed, all suggestive of arsenic induced oxidative stress. Histopathological examination under light and transmission electron microscope suggested a combination of ongoing necrosis and apoptosis. DNA-TUNEL showed an increase in apoptotic cells in liver. Agarose gel electrophoresis of DNA of hepatocytes resulted in a characteristic ladder pattern. Conclusion: Chronic arsenic administration induces a specific pattern of apoptosis called post-mitotic apoptosis

Effect of caffeine on radiation-induced apoptosis in TK6 cells

International Nuclear Information System (INIS)

Zhen, W.; Vaughan, A.T.M.

1995-01-01

Apoptosis has been measured in cells of the human TK6 lymphoblastoid cell line by recording the release of endonuclease-digested DNA from affected cells using flow cytometry. In asynchronously dividing cells, DNA degradation characteristic of apoptosis was first seen 12 h after irradiation as a defined DNA fluorescent peak of sub-G 1 -phase content, reaching a maximum of 30-50% of the population by 24-72 h. Treating cells with 2 mM caffeine either before or up to 3 h after irradiation eliminated the degradation of DNA entirely. In addition, the percentage of cells in which apoptosis could be detected microscopically decreased from 62.4 ± 0.95% to 16.7 ± 1.5% 72 h after caffeine treatment. Delaying caffeine treatment for 12 h after irradiation reduced DNA degradation by approximately 50% compared to cells receiving radiation alone. DNA degradation induced by serum deprivation was unaffected by caffeine treatment. These data support the contention that irradiation of TK6 cells produces a long-lived cellular signal which triggers apoptosis. Apoptosis produced by serum deprivation does not operate through the same pathway. 36 refs., 5 figs

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

Myostatin induces mitochondrial metabolic alteration and typical apoptosis in cancer cells

Science.gov (United States)

Liu, Y; Cheng, H; Zhou, Y; Zhu, Y; Bian, R; Chen, Y; Li, C; Ma, Q; Zheng, Q; Zhang, Y; Jin, H; Wang, X; Chen, Q; Zhu, D

2013-01-01

Myostatin, a member of the transforming growth factor-β superfamily, regulates the glucose metabolism of muscle cells, while dysregulated myostatin activity is associated with a number of metabolic disorders, including muscle cachexia, obesity and type II diabetes. We observed that myostatin induced significant mitochondrial metabolic alterations and prolonged exposure of myostatin induced mitochondria-dependent apoptosis in cancer cells addicted to glycolysis. To address the underlying mechanism, we found that the protein levels of Hexokinase II (HKII) and voltage-dependent anion channel 1 (VDAC1), two key regulators of glucose metabolisms as well as metabolic stress-induced apoptosis, were negatively correlated. In particular, VDAC1 was dramatically upregulated in cells that are sensitive to myostatin treatment whereas HKII was downregulated and dissociated from mitochondria. Myostatin promoted the translocation of Bax from cytosol to mitochondria, and knockdown of VDAC1 inhibited myostatin-induced Bax translocation and apoptosis. These apoptotic changes can be partially rescued by repletion of ATP, or by ectopic expression of HKII, suggesting that perturbation of mitochondrial metabolism is causally linked with subsequent apoptosis. Our findings reveal novel function of myostatin in regulating mitochondrial metabolism and apoptosis in cancer cells. PMID:23412387

Effect of caffeine on radiation-induced apoptosis in TK6 cells

Energy Technology Data Exchange (ETDEWEB)

Zhen, W.; Vaughan, A.T.M. [Loyola Univ. Chicago, Maywood, IL (United States)

1995-02-01

Apoptosis has been measured in cells of the human TK6 lymphoblastoid cell line by recording the release of endonuclease-digested DNA from affected cells using flow cytometry. In asynchronously dividing cells, DNA degradation characteristic of apoptosis was first seen 12 h after irradiation as a defined DNA fluorescent peak of sub-G{sub 1}-phase content, reaching a maximum of 30-50% of the population by 24-72 h. Treating cells with 2 mM caffeine either before or up to 3 h after irradiation eliminated the degradation of DNA entirely. In addition, the percentage of cells in which apoptosis could be detected microscopically decreased from 62.4 {+-} 0.95% to 16.7 {+-} 1.5% 72 h after caffeine treatment. Delaying caffeine treatment for 12 h after irradiation reduced DNA degradation by approximately 50% compared to cells receiving radiation alone. DNA degradation induced by serum deprivation was unaffected by caffeine treatment. These data support the contention that irradiation of TK6 cells produces a long-lived cellular signal which triggers apoptosis. Apoptosis produced by serum deprivation does not operate through the same pathway. 36 refs., 5 figs.

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.

Bcl-2 silencing attenuates hypoxia-induced apoptosis resistance in pulmonary microvascular endothelial cells.

Science.gov (United States)

Cao, Yongmei; Jiang, Zhen; Zeng, Zhen; Liu, Yujing; Gu, Yuchun; Ji, Yingying; Zhao, Yupeng; Li, Yingchuan

2016-01-01

Pulmonary arterial hypertension (PAH) is a life-threatening disorder that ultimately causes heart failure. While the underlying causes of this condition are not well understood, previous studies suggest that the anti-apoptotic nature of pulmonary microvascular endothelial cells (PMVECs) in hypoxic environments contributes to PAH pathogenesis. In this study, we focus on the contribution of Bcl-2 and hypoxia response element (HRE) to apoptosis-resistant endothelial cells and investigate the mechanism. PMVECs obtained from either normal rats or apoptosis-resistant PMVECs obtained from PAH rats were transduced with recombinant lentiviral vectors carrying either Bcl-2-shRNA or HRE combined Bcl-2-shRNA, and then cultured these cells for 24 h under hypoxic (5% O2) or normoxic (21% O2) conditions. In normal PMVECs, Bcl-2-shRNA or HRE combined with Bcl-2-shRNA transduction successfully decreased Bcl-2 expression, while increasing apoptosis as well as caspase-3 and P53 expression in a normoxic environment. In a hypoxic environment, the effects of Bcl-2-shRNA treatment on cell apoptosis, and on Bcl-2, caspase-3, P53 expression were significantly suppressed. Conversely, HRE activation combined with Bcl-2-shRNA transduction markedly enhanced cell apoptosis and upregulated caspase-3 and P53 expression, while decreasing Bcl-2 expression. Furthermore, in apoptosis-resistant PMVECs, HRE-mediated Bcl-2 silencing effectively enhanced cell apoptosis and caspase-3 activity. The apoptosis rate was significantly depressed when Lv-HRE-Bcl-2-shRNA was combined with Lv-P53-shRNA or Lv-caspase3-shRNA transduction in a hypoxic environment. These results suggest that HRE-mediated Bcl-2 inhibition can effectively attenuate hypoxia-induced apoptosis resistance in PMVECs by downregulating Bcl-2 expression and upregulating caspase-3 and P53 expression. This study therefore reveals critical insight into potential therapeutic targets for treating PAH.

Ellipticine induces apoptosis in T-cell lymphoma via oxidative DNA damage

DEFF Research Database (Denmark)

Savorani, Cecilia; Manfé, Valentina; Biskup, Edyta

2015-01-01

(CTCL), a disease that is progressive, chemoresistant and refractory to treatment. We tested the effect of ellipticine in three cell lines with different p53 status: MyLa2000 (p53(wt/wt)), SeAx ((G245S)p53) and Hut-78 ((R196Stop)p53). Ellipticine caused apoptosis in MyLa2000 and SeAx and restored...... the transcriptional activity of (G245S)p53 in SeAx. However, p53 siRNA knockdown experiments revealed that p53 was not required for ellipticine-induced apoptosis in CTCL. The lipophilic antioxidant α-tocopherol inhibited ellipticine-dependent apoptosis and we linked the apoptotic response to the oxidative DNA damage....... Our results provide evidence that ellipticine-induced apoptosis is exerted through DNA damage and does not require p53 activation in T-cell lymphoma....

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

PURPOSE: The immune privilege of the eye has been thought to be dependent on physical barriers and absence of lymphatic vessels. However, the immune privilege may also involve active immunologic processes, as recent studies have indicated. The purpose of the present study was to investigate whether...... 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...

Molecular Mechanisms Regulating Ocular Apoptosis in Zebrafish gdf6a Mutants

DEFF Research Database (Denmark)

Pant, Sameer D.; March, Lindsey D.; Famulski, Jakub K.

2013-01-01

intrinsic or extrinsic apoptotic mechanisms were involved, morpholino antisense oligonucleotides targeting baxa, baxb, and p53 were employed. Caspase-3 immunohistochemistry (IHC) was performed to assay apoptosis. Pharmacologic inhibition (using SB203580) and IHC were used to investigate the role of p38...... occurs 28 hours post fertilization (hpf) in gdf6a(-/-) mutants that is mediated independently of p53 by intrinsic mechanisms involving Bax proteins. Also, gdf6a(-/-) mutants exhibit markedly increased p38 MAP kinase activation that can be inhibited to significantly reduce retinal apoptosis. A reduction...... in retinal smad1 expression was also noted in gdf6a(-/-) mutants. CONCLUSIONS. gdf6a(-/-)-induced apoptosis is characterized by the involvement of intrinsic apoptotic pathways, p38 MAP kinases, and dysregulated smad expression. Modulation of key mediators can inhibit retinal apoptosis offering potential...

Apoptosis and Tumor Progressionin Prostate Cancer

National Research Council Canada - National Science Library

Tenniswood, Martin P

2005-01-01

... (as measured by BrdU incorporation) and apoptosis as measured by TUNEL staining. We have standardized an efficient methodologies for isolating cells from primary tumors expressing REP by fluorescence activated cell sorting (FACS...

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

Role of nuclear bodies in apoptosis signalling.

Science.gov (United States)

Krieghoff-Henning, Eva; Hofmann, Thomas G

2008-11-01

Promyelocytic leukemia nuclear bodies (PML NBs) are dynamic macromolecular multiprotein complexes that recruit and release a plethora of proteins. A considerable number of PML NB components play vital roles in apoptosis, senescence regulation and tumour suppression. The molecular basis by which PML NBs control these cellular responses is still just beginning to be understood. In addition to PML itself, numerous further tumour suppressors including transcriptional regulator p53, acetyl transferase CBP (CREB binding protein) and protein kinase HIPK2 (homeodomain interacting protein kinase 2) are recruited to PML NBs in response to genotoxic stress or oncogenic transformation and drive the senescence and apoptosis response by regulating p53 activity. Moreover, in response to death-receptor activation, PML NBs may act as nuclear depots that release apoptotic factors, such as the FLASH (FLICE-associated huge) protein, to amplify the death signal. PML NBs are also associated with other nuclear domains including Cajal bodies and nucleoli and share apoptotic regulators with these domains, implying crosstalk between NBs in apoptosis regulation. In conclusion, PML NBs appear to regulate cell death decisions through different, pathway-specific molecular mechanisms.

Studies on hematopoietic cell apoptosis and the relative gene expression in irradiated mouse bone marrow

International Nuclear Information System (INIS)

Peng Ruiyun; Wang Dewen; Xiong Chengqi; Gao Yabing; Yang Hong; Cui Yufang; Wang Baozhen

2001-01-01

Objective: To study apoptosis and expressions bcl-2 and p53 in irradiated mouse bone marrow. Methods: LACA mice were irradiated with 60 Co γ-rays. By means of in situ terminal labelling, in situ hybridization and image analysis, the authors studied radiation-induced apoptosis of hematopoietic cells and the expressions of bcl-2 and p53. Results: The characteristics of apoptosis appeared in hematopoietic cells at 6 hrs after irradiation. The expression of bcl-2 was obviously decreased when apoptosis of hematopoietic cells occurred, whereas it increased in the early recovery phase; p53 protein increased during both apoptosis of hematopoietic cells and the recovery phase, and mutant type p53 DNA was positive only in the recovery phase. Conclusion: Radiation may induced apoptosis of hematopoietic cells in a dose-dependent manner; Both bcl-2 and p53 genes play an important role in apoptosis and recovery phase

The roles of Bcl-xL in modulating apoptosis during development of Xenopus laevis

Directory of Open Access Journals (Sweden)

Calderon-Segura Maria

2005-09-01

Full Text Available Abstract Background Apoptosis is a common and essential aspect of development. It is particularly prevalent in the central nervous system and during remodelling processes such as formation of the digits and in amphibian metamorphosis. Apoptosis, which is dependent upon a balance between pro- and anti-apoptotic factors, also enables the embryo to rid itself of cells damaged by gamma irradiation. In this study, the roles of the anti-apoptotic factor Bcl-xL in protecting cells from apoptosis were examined in Xenopus laevis embryos using transgenesis to overexpress the XR11 gene, which encodes Bcl-xL. The effects on developmental, thyroid hormone-induced and γ-radiation-induced apoptosis in embryos were examined in these transgenic animals. Results Apoptosis was abrogated in XR11 transgenic embryos. However, the transgene did not prevent the apoptotic response of tadpoles to thyroid hormone during metamorphosis. Post-metamorphic XR11 frogs were reared to sexual maturity, thus allowing us to produce second-generation embryos and enabling us to distinguish between the maternal and zygotic contributions of Bcl-xL to the γ-radiation apoptotic response. Wild-type embryos irradiated before the mid-blastula transition (MBT underwent normal cell division until reaching the MBT, after which they underwent massive, catastrophic apoptosis. Over-expression of Bcl-xL derived from XR11 females, but not males, provided partial protection from apoptosis. Maternal expression of XR11 was also sufficient to abrogate apoptosis triggered by post-MBT γ-radiation. Tolerance to post-MBT γ-radiation from zygotically-derived XR11 was acquired gradually after the MBT in spite of abundant XR11 protein synthesis. Conclusion Our data suggest that Bcl-xL is an effective counterbalance to proapoptotic factors during embryonic development but has no apparent effect on the thyroid hormone-induced apoptosis that occurs during metamorphosis. Furthermore, post-MBT apoptosis

Cigarette smoke causes caspase-independent apoptosis of bronchial epithelial cells from asthmatic donors.

Directory of Open Access Journals (Sweden)

Fabio Bucchieri

Full Text Available Epidemiologic studies have demonstrated important links between air pollution and asthma. Amongst these pollutants, environmental cigarette smoke is a risk factor both for asthma pathogenesis and exacerbation. As the barrier to the inhaled environment, the bronchial epithelium is a key structure that is exposed to cigarette smoke.Since primary bronchial epithelial cells (PBECs from asthmatic donors are more susceptible to oxidant-induced apoptosis, we hypothesized that they would be susceptible to cigarette smoke-induced cell death.PBECs from normal and asthmatic donors were exposed to cigarette smoke extract (CSE; cell survival and apoptosis were assessed by fluorescence-activated cell sorting, and protective effects of antioxidants evaluated. The mechanism of cell death was evaluated using caspase inhibitors and immunofluorescent staining for apoptosis-inducing factor (AIF.Exposure of PBEC cultures to CSE resulted in a dose-dependent increase in cell death. At 20% CSE, PBECs from asthmatic donors exhibited significantly more apoptosis than cells from non-asthmatic controls. Reduced glutathione (GSH, but not ascorbic acid (AA, protected against CSE-induced apoptosis. To investigate mechanisms of CSE-induced apoptosis, caspase-3 or -9 inhibitors were tested, but these failed to prevent apoptosis; in contrast, CSE promoted nuclear translocation of AIF from the mitochondria. GSH reduced the number of nuclear-AIF positive cells whereas AA was ineffective.Our results show that PBECs from asthmatic donors are more susceptible to CSE-induced apoptosis. This response involves AIF, which has been implicated in DNA damage and ROS-mediated cell-death. Epithelial susceptibility to CSE may contribute to the impact of environmental tobacco smoke in asthma.

The role of apoptosis in MCLR-induced developmental toxicity in zebrafish embryos

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Zeng, Cheng [College of Fisheries, Huazhong Agricultural University, Wuhan 430070 (China); Sun, Hong [Hubei Maternal and Child Health Hospital, Wuhan 430070 (China); Xie, Ping [Donghu Experimental Station of Lake Ecosystems, State Key Laboratory for Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072 (China); Wang, Jianghua; Zhang, Guirong; Chen, Nan [College of Fisheries, Huazhong Agricultural University, Wuhan 430070 (China); Yan, Wei, E-mail: Yanwei75126@163.com [Institute of Agricultural Quality Standards and Testing Technology, Hubei Academy of Agricultural Sciences, Wuhan 430064 (China); Li, Guangyu, E-mail: ligy2001@163.com [College of Fisheries, Huazhong Agricultural University, Wuhan 430070 (China); Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070 (China)

2014-04-01

Highlights: • MCLR-induced apoptosis in the heart of developing embryos leads to the growth delay in zebrafish. • MCLR-triggered apoptosis might be induced by ROS. • P53–Bax–Bcl-2 and caspase-dependent apoptotic pathway contribute greatly to MCLR-induced apoptosis. Abstract: We previously demonstrated that cyanobacteria-derived microcystin–leucine–arginine (MCLR) is able to induce developing toxicity, such as malformation, growth delay and also decreased heart rates in zebrafish embryos. However, the molecular mechanisms by which MCLR induces its toxicity during the development of zebrafish remain largely unknown. Here, we evaluate the role of apoptosis in MCLR-induced developmental toxicity. Zebrafish embryos were exposed to various concentrations of MCLR (0, 0.2, 0.5, 2, and 5.0 mg L⁻¹ for 96 h, at which time reactive oxygen species (ROS) was significantly induced in the 2 and 5.0 mg L⁻¹ MCLR exposure groups. Acridine orange (AO) staining and terminal deoxynucleotide transferase-mediated deoxy-UTP nick end labelling (TUNEL) assay showed that MCLR exposure resulted in cell apoptosis. To test the apoptotic pathway, the expression pattern of several apoptotic-related genes was examined for the level of enzyme activity, gene and protein expression, respectively. The overall results demonstrate that MCLR induced ROS which consequently triggered apoptosis in the heart of developing zebrafish embryos. Our results also indicate that the p53–Bax–Bcl-2 pathway and the caspase-dependent apoptotic pathway play major roles in MCLR-induced apoptosis in the developing embryos.

Construction and analysis of a modular model of caspase activation in apoptosis

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Ho Kenneth L

2008-12-01

Full Text Available Abstract Background A key physiological mechanism employed by multicellular organisms is apoptosis, or programmed cell death. Apoptosis is triggered by the activation of caspases in response to both extracellular (extrinsic and intracellular (intrinsic signals. The extrinsic and intrinsic pathways are characterized by the formation of the death-inducing signaling complex (DISC and the apoptosome, respectively; both the DISC and the apoptosome are oligomers with complex formation dynamics. Additionally, the extrinsic and intrinsic pathways are coupled through the mitochondrial apoptosis-induced channel via the Bcl-2 family of proteins. Results A model of caspase activation is constructed and analyzed. The apoptosis signaling network is simplified through modularization methodologies and equilibrium abstractions for three functional modules. The mathematical model is composed of a system of ordinary differential equations which is numerically solved. Multiple linear regression analysis investigates the role of each module and reduced models are constructed to identify key contributions of the extrinsic and intrinsic pathways in triggering apoptosis for different cell lines. Conclusion Through linear regression techniques, we identified the feedbacks, dissociation of complexes, and negative regulators as the key components in apoptosis. The analysis and reduced models for our model formulation reveal that the chosen cell lines predominately exhibit strong extrinsic caspase, typical of type I cell, behavior. Furthermore, under the simplified model framework, the selected cells lines exhibit different modes by which caspase activation may occur. Finally the proposed modularized model of apoptosis may generalize behavior for additional cells and tissues, specifically identifying and predicting components responsible for the transition from type I to type II cell behavior.

Augmenter of liver regeneration (ALR) protects human hepatocytes against apoptosis

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Ilowski, Maren [Liver Regeneration Group, Department of Surgery, Grosshadern Hospital, Ludwig Maximilians University, Munich (Germany); Kleespies, Axel [Department of Surgery, Grosshadern Hospital, Ludwig Maximilians University, Munich (Germany); Toni, Enrico N. de [Department of Medicine II, Grosshadern Hospital, Ludwig Maximilians University, Munich (Germany); Donabauer, Barbara [Liver Regeneration Group, Department of Surgery, Grosshadern Hospital, Ludwig Maximilians University, Munich (Germany); Jauch, Karl-Walter [Department of Surgery, Grosshadern Hospital, Ludwig Maximilians University, Munich (Germany); Hengstler, Jan G. [Leibniz Research Centre for Working Environment and Human Factors, Technical University, Dortmund (Germany); Thasler, Wolfgang E., E-mail: wolfgang.thasler@med.uni-muenchen.de [Liver Regeneration Group, Department of Surgery, Grosshadern Hospital, Ludwig Maximilians University, Munich (Germany); Department of Surgery, Grosshadern Hospital, Ludwig Maximilians University, Munich (Germany)

2011-01-07

Research highlights: {yields} ALR decreases cytochrome c release from mitochondria. {yields} ALR protects hepatocytes against apoptosis induction by ethanol, TRAIL, anti-Apo, TGF-{beta} and actinomycin D. {yields} ALR exerts a liver-specific anti-apoptotic effect. {yields} A possible medical usage of ALR regarding protection of liver cells during apoptosis inducing therapies. -- Abstract: Augmenter of liver regeneration (ALR) is known to support liver regeneration and to stimulate proliferation of hepatocytes. However, it is not known if ALR exerts anti-apoptotic effects in human hepatocytes and whether this protective effect is cell type specific. This is relevant, because compounds that protect the liver against apoptosis without undesired effects, such as protection of metastatic tumour cells, would be appreciated in several clinical settings. Primary human hepatocytes (phH) and organotypic cancer cell lines were exposed to different concentrations of apoptosis inducers (ethanol, TRAIL, anti-Apo, TGF-{beta}, actinomycin D) and cultured with or without recombinant human ALR (rhALR). Apoptosis was evaluated by the release of cytochrome c from mitochondria and by FACS with propidium iodide (PI) staining. ALR significantly decreased apoptosis induced by ethanol, TRAIL, anti-Apo, TGF-{beta} and actinomycin D. Further, the anti-apoptotic effect of ALR was observed in primary human hepatocytes and in HepG2 cells but not in bronchial (BC1), colonic (SW480), gastric (GC1) and pancreatic (L3.6PL) cell lines. Therefore, the hepatotrophic growth factor ALR acts in a liver specific manner with regards to both its mitogenic and its anti-apoptotic effect. Unlike the growth factors HGF and EGF, rhALR acts in a liver specific manner. Therefore, ALR is a promising candidate for further evaluation as a possible hepatoprotective factor in clinical settings.

Augmenter of liver regeneration (ALR) protects human hepatocytes against apoptosis

International Nuclear Information System (INIS)

Ilowski, Maren; Kleespies, Axel; Toni, Enrico N. de; Donabauer, Barbara; Jauch, Karl-Walter; Hengstler, Jan G.; Thasler, Wolfgang E.

2011-01-01

Research highlights: → ALR decreases cytochrome c release from mitochondria. → ALR protects hepatocytes against apoptosis induction by ethanol, TRAIL, anti-Apo, TGF-β and actinomycin D. → ALR exerts a liver-specific anti-apoptotic effect. → A possible medical usage of ALR regarding protection of liver cells during apoptosis inducing therapies. -- Abstract: Augmenter of liver regeneration (ALR) is known to support liver regeneration and to stimulate proliferation of hepatocytes. However, it is not known if ALR exerts anti-apoptotic effects in human hepatocytes and whether this protective effect is cell type specific. This is relevant, because compounds that protect the liver against apoptosis without undesired effects, such as protection of metastatic tumour cells, would be appreciated in several clinical settings. Primary human hepatocytes (phH) and organotypic cancer cell lines were exposed to different concentrations of apoptosis inducers (ethanol, TRAIL, anti-Apo, TGF-β, actinomycin D) and cultured with or without recombinant human ALR (rhALR). Apoptosis was evaluated by the release of cytochrome c from mitochondria and by FACS with propidium iodide (PI) staining. ALR significantly decreased apoptosis induced by ethanol, TRAIL, anti-Apo, TGF-β and actinomycin D. Further, the anti-apoptotic effect of ALR was observed in primary human hepatocytes and in HepG2 cells but not in bronchial (BC1), colonic (SW480), gastric (GC1) and pancreatic (L3.6PL) cell lines. Therefore, the hepatotrophic growth factor ALR acts in a liver specific manner with regards to both its mitogenic and its anti-apoptotic effect. Unlike the growth factors HGF and EGF, rhALR acts in a liver specific manner. Therefore, ALR is a promising candidate for further evaluation as a possible hepatoprotective factor in clinical settings.

Cu2+-labeled dansyl compounds as fluorescent and PET probes for imaging apoptosis.

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Han, Junyan; Wang, Xukui; Yu, MeiXiang

2016-11-15

Compound DNSTT-Cu 2+ , a novel chelate of Cu 2+ with DOTA conjugated to a fluorescent dansyl fragment, is developed for imaging cell apoptosis. Apoptotic U-87MG cells could be selectively visualized by the fluorescence of DNSTT-Cu 2+ from cytoplasm of cells, confirmed by the fluorescence of apoptosis cells co-labeled with Alexa Fluor 568-labeled annexin V, a conventional probe for selectively labeling membranes of apoptosis cells. A radioactive 64 Cu 2 + analog, DNSTT- 64 Cu 2+ , was easily synthesized, providing a potential PET probe for imaging apoptosis in vivo. Copyright © 2016 Elsevier Ltd. All rights reserved.

Apoptosis and signalling in acid sphingomyelinase deficient cells

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Sillence Dan J

2001-11-01

Full Text Available Abstract Background Recent evidence suggests that the activation of a non-specific lipid scramblase during apoptosis induces the flipping of sphingomyelin from the cell surface to the cytoplasmic leaftet of the plasma membrane. Inner leaflet sphingomyelin is then cleaved to ceramide by a neutral sphingomyelinase. The production of this non-membrane forming lipid induces blebbing of the plasma membrane to aid rapid engulfment by professional phagocytes. However contrary evidence suggests that cells which are deficient in acid sphingomyelinase are defective in apoptosis signalling. This data has been interpreted as support for the activation of acid sphingomyelinase as an early signal in apoptosis. Hypothesis An alternative explanation is put forward whereby the accumulation of intracellular sphingomyelin in sphingomyelinase deficient cells leads to the formation of intracellular rafts which lead to the sequestration of important signalling molecules that are normally present on the cell surface where they perform their function. Testing the hypothesis It is expected that the subcellular distribution of important signalling molecules is altered in acid sphingomyelinase deficient cells, leading to their sequestration in late endosomes / lysosomes. Other sphingolipid storage diseases such as Niemann-Pick type C which have normal acid sphingomyelinase activity would also be expected to show the same phenotype. Implications of the hypothesis If true the hypothesis would provide a mechanism for the pathology of the sphingolipid storage diseases at the cellular level and also have implications for the role of ceramide in apoptosis.

Effect of ionizing radiation on apoptosis in mouse Peyer's patches

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Liu Jiamei; Chen Dong; Liu Shuzheng

1999-01-01

The relationship of time-effect and dose-effect of apoptosis in mouse Peyer's patches after whole body irradiation (WBI) with different doses of X-rays was studied by the method of TdT-mediated dUTP nick end labelling (TUNEL). The results showed that the number of TUNEL positive cells in mouse Peyer's patches were significantly increased following WBI with 2 Gy irradiation, While the number of TUNEL positive cells were decreased after WBI with doses of 0.05 Gy and 0.075 Gy X-rays. the results support the view that 2 Gy irradiation promote the apoptosis of immune cells and the low doses of radiation suppress the apoptosis of immune cells

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

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

2015-08-01

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

MicroRNA-1185 Induces Endothelial Cell Apoptosis by Targeting UVRAG and KRIT1

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Haoyuan Deng

2017-04-01

Full Text Available Background/Aims: Atherosclerosis is a multifactorial chronic disease and is the main cause of death and impairment in the world. Endothelial injury and apoptosis play a crucial role in the onset and development of atherosclerosis. MicroRNAs (miRNAs have been proven to be involved in the pathogenesis of atherosclerosis. However, studies of the functional role of apoptosis-related miRNAs in the endothelium during atherogenesis are limited. Methods: Cell injury and apoptosis were measured in five types of cells transfected with miR-1185 or co-transfected with miR-1185 and its inhibitor. Bioinformatics analysis and a luciferase reporter assay were used to confirm the targets of miR-1185. The effects of the targets of miR-1185 on endothelial apoptosis were determined using small-interfering RNA. Results: In this study, we first report that miR-1185 significantly promoted apoptosis in endothelial cells but not in vascular smooth muscle cells and macrophages. A mechanistic analysis showed that ultraviolet irradiation resistance-associated gene (UVRAG and krev1 interaction trapped gene 1 (KRIT1, targets of miR-1185, mediated miR-1185-induced endothelial cell apoptosis. Conclusion: The results revealed the impact of miR-1185 on endothelial apoptosis, suggesting that miR-1185 may be a potential target for the prevention and treatment of atherosclerosis.

Hypoxia-induced p53 modulates both apoptosis and radiosensitivity via AKT

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Leszczynska, K.B.; Foskolou, I.P.; Abraham, A.G.; Anbalagan, S.; Tellier, C.; Haider, S.; Span, P.N.; O'Neill, E.E.; Buffa, F.M.; Hammond, E.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

Herbal medicine as inducers of apoptosis in cancer treatment.

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

2014-10-01

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

Induction and regulation of tumor necrosis factor-related apoptosis-inducing ligand/Apo-2 ligand-mediated apoptosis in renal cell carcinoma.

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Griffith, Thomas S; Fialkov, Jonathan M; Scott, David L; Azuhata, Takeo; Williams, Richard D; Wall, Nathan R; Altieri, Dario C; Sandler, Anthony D

2002-06-01

The lack of effective therapy for disseminated renal cell carcinoma (RCC) has stimulated the search for novel treatments including immunotherapeutic strategies. However, poor therapeutic responses and marked toxicity associated with immunological agents has limited their use. The tumor necrosis factor family member tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)/Apo-2 ligand induces apoptosis in a variety of tumor cell types, while having little cytotoxic activity against normal cells. In this study the activation and regulation of TRAIL-induced apoptosis and TRAIL receptor expression in human RCC cell lines and pathologic specimens was examined. TRAIL induced caspase-mediated apoptotic death of RCC cells with variable sensitivities among the cell lines tested. Compared with TRAIL-sensitive RCC cell lines (A-498, ACHN, and 769-P), the TRAIL-resistant RCC cell line (786-O) expressed lesser amounts of the death-inducing TRAIL receptors, and greater amounts of survivin, an inhibitor of apoptosis. Incubation of 786-O with actinomycin D increased the expression of the death-inducing TRAIL receptors and, concomitantly, decreased the intracellular levels of survivin, resulting in TRAIL-induced apoptotic death. The link between survivin and TRAIL regulation was confirmed when an increase in TRAIL resistance was observed after overexpression of survivin in the TRAIL-sensitive, survivin-negative RCC line A-498. These findings, along with our observation that TRAIL receptors are expressed in RCC tumor tissue, suggest that TRAIL may be useful as a therapeutic agent for RCC and that survivin may partially regulate TRAIL-induced cell death.

Independent regulation of reovirus membrane penetration and apoptosis by the mu1 phi domain.

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Danthi, Pranav; Coffey, Caroline M; Parker, John S L; Abel, Ty W; Dermody, Terence S

2008-12-01

Apoptosis plays an important role in the pathogenesis of reovirus encephalitis. Reovirus outer-capsid protein mu1, which functions to penetrate host cell membranes during viral entry, is the primary regulator of apoptosis following reovirus infection. Ectopic expression of full-length and truncated forms of mu1 indicates that the mu1 phi domain is sufficient to elicit a cell death response. To evaluate the contribution of the mu1 phi domain to the induction of apoptosis following reovirus infection, phi mutant viruses were generated by reverse genetics and analyzed for the capacity to penetrate cell membranes and elicit apoptosis. We found that mutations in phi diminish reovirus membrane penetration efficiency by preventing conformational changes that lead to generation of key reovirus entry intermediates. Independent of effects on membrane penetration, amino acid substitutions in phi affect the apoptotic potential of reovirus, suggesting that phi initiates apoptosis subsequent to cytosolic delivery. In comparison to wild-type virus, apoptosis-defective phi mutant viruses display diminished neurovirulence following intracranial inoculation of newborn mice. These results indicate that the phi domain of mu1 plays an important regulatory role in reovirus-induced apoptosis and disease.

Independent regulation of reovirus membrane penetration and apoptosis by the mu1 phi domain.

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Pranav Danthi

2008-12-01

Full Text Available Apoptosis plays an important role in the pathogenesis of reovirus encephalitis. Reovirus outer-capsid protein mu1, which functions to penetrate host cell membranes during viral entry, is the primary regulator of apoptosis following reovirus infection. Ectopic expression of full-length and truncated forms of mu1 indicates that the mu1 phi domain is sufficient to elicit a cell death response. To evaluate the contribution of the mu1 phi domain to the induction of apoptosis following reovirus infection, phi mutant viruses were generated by reverse genetics and analyzed for the capacity to penetrate cell membranes and elicit apoptosis. We found that mutations in phi diminish reovirus membrane penetration efficiency by preventing conformational changes that lead to generation of key reovirus entry intermediates. Independent of effects on membrane penetration, amino acid substitutions in phi affect the apoptotic potential of reovirus, suggesting that phi initiates apoptosis subsequent to cytosolic delivery. In comparison to wild-type virus, apoptosis-defective phi mutant viruses display diminished neurovirulence following intracranial inoculation of newborn mice. These results indicate that the phi domain of mu1 plays an important regulatory role in reovirus-induced apoptosis and disease.

Effect of Vitrification on Sperm Parameters and Apoptosis in Fertile Men

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M Adib

2011-01-01

Full Text Available Introduction & Objective: Today, cryopreservation of the human sperm is a common technique for treating infertility. It has been indicated that cryopreservation by different methods decrease the sperm motility and viability in fertile men, but still effect of freezing of the sperm by vitrification method have not been evaluated on sperm parameters and apoptosis. The aim of this study was to evaluate the effect of vitrification of sperm of fertile men on different sperm parameters (motility, morphology, viability and count and apoptosis after thawing. Materials & Methods: In this experimental study which was conducted at Yazd Infertility Research and Clinical Center in 2009, seventeen semen samples were collected by masturbation from people who came to this centre. Semen analysis was performed according to WHO standards. Smear was provided from these samples and fixed for TUNEL staining. Some samples were directly cryopreserved by cryoloope in liquid nitrogen and stored at least for Seven days. After thawing, samples were evaluated for sperm parameters. The collected data was analyzed by the SPSS software using paired T-test and Willcoxon statistical test. Results: The progressive movement of sperm was significantly decreased by vitrification. Also significant decrease in viability and morphology of the sperm and increase in the rate of apoptosis was observed after vitrification. The amount of apoptosis had negatively correlated with normal parameters of spermatozoa (especially progressive motility and viability. Conclusion: These results indicated that vitrification is harmful for sperm parameters and of apoptosis rate in fertile men. However, the apoptosis rate was lower compared to other freezing methods.

Induction of apoptosis by Citrus paradisi essential oil in human leukemic (HL-60) cells.

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Hata, Tomona; Sakaguchi, Ikuyo; Mori, Masahiro; Ikeda, Norikazu; Kato, Yoshiko; Minamino, Miki; Watabe, Kazuhito

2003-01-01

Limonene is a primary component of citrus essential oils (EOs) and has been reported to induce apoptosis on tumor cells. Little is known about induction of apoptosis by citrus EOs. In this study, we examined induction of apoptosis by Citrus aurantium var. dulcis (sweet orange) EO, Citrus paradisi (grapefruit) EO and Citrus limon (lemon) EO. These EOs induced apoptosis in HL-60 cells and the apoptosis activities were related to the limonene content of the EOs. Moreover, sweet orange EO and grapefruit EO may contain components besides limonene that have apoptotic activity. To identify the components with apoptotic activity, grapefruit EO was fractionated using silica gel columns, and the components were analyzed by GC-MS. The n-hexane fraction contained limonene, and the dichloromethane fraction (DF) contained aldehyde compounds and nootkatone. Decanal, octanal and citral in the DF showed strong apoptotic activity, suggesting that the aldehyde compounds induced apoptosis strongly in HL-60 cells.

Apoptosis in thymocytes and lymphoma cells induced by neutrons and X-rays

International Nuclear Information System (INIS)

Ohyama, Harumi; Koike, Sachiko; Ando, Kouichi

1993-01-01

Apoptosis is a distinctive mode of programmed cell death with characteristic morphological and biochemical features. The cells undergoing apoptosis display shrinkage, chromatin condensation and internucleosomal breakage of DNA. The cell death is a process through which organisms get rid of unwanted cells. Thymocytes are highly radiosensitive, and undergo typical apoptosis within a few hours after the exposure to X-ray. Also extremely radiosensitive thymic lymphoma cells have been found. The effect of 30 MeV NIRS fast neutrons on the induction of apoptosis in thymocytes and thymoma cells was examined in comparison with that of X-ray. Although apoptotic cells increased gradually with time, the apoptotic process proceeded rapidly in individual cells after the onset. By the measurement of cell size distribution, the appearance of a distinct apoptotic cell peak was observed. In the case of neutron irradiation on SCA1 thymic lymphoma cells, the method for counting apoptotic cells based on chromatin condensation was developed. The cell volume reduction of thymocytes, the dose survival curves and the induction of apoptosis in SCA1 are reported. (K.I.)

Bullatacin Triggered ABCB1-Overexpressing Cell Apoptosis via the Mitochondrial-Dependent Pathway

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Yong-Ju Liang

2009-01-01

Full Text Available This paper was to explore bullatacin-mediated multidrug-resistant cell apoptosis at extremely low concentration. To investigate its precise mechanisms, the pathway of cell apoptosis induced by bullatacin was examined. Bullatacin causes an upregulation of ROS and a downregulation of ΔΨm in a concentration-dependent manner in ABCB1-overexpressing KBv200 cells. In addition, cleavers of caspase-9, caspase-3, and PARP were observed following the release of cytochrome c from mitochondria after bullatacin treatment. However, neither cleavage of caspase-8 nor change of expression level of bcl-2, bax and Fas was observed by the same treatment. Pretreating KBv200 cells with N-acetylcysteine, an antioxidant modulator, resulted in a significant reduction of ROS generation and cell apoptosis induced by bullatacin. Bullatacin-induced apoptosis was antagonized by z-LEHD-fmk, a caspase-9 inhibitor, but not by z-IETD-fmk, a caspase-8 inhibitor. These implied that apoptosis of KBv200 cells induced by bullatacin was associated with the mitochondria-dependent pathway that was limited to activation of apical caspase-9.

The emphysematous lung is abnormally sensitive to TRAIL-mediated apoptosis

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Milot Julie

2011-08-01

Full Text Available Abstract Background Alveolar apoptosis is increased in the emphysematous lung. However, mechanisms involved are not fully understood. Recently, we demonstrated that levels of TRAIL receptor 1 and 2, levels of p53, and Bax/Bcl-xL ratio were elevated in the lung of subjects with emphysema, despite smoking cessation. Thus, we postulate that due to chronic pulmonary oxidative stress, the emphysematous lung would be abnormally sensitive to TRAIL-mediated apoptosis. Methodology A549 cells were exposed to rTRAIL, cigarette smoke extract, and/or H2O2 prior to caspase-3 activity measurement and annexin V staining assessment. In addition, freshly resected lung samples were obtained from non-emphysematous and emphysematous subjects and exposed ex vivo to rTRAIL for up to 18 hours. Lung samples were harvested and levels of active caspase-3 and caspase-8 were measured from tissue lysates. Results Both cigarette smoke extract and H2O2 were able to sensitize A549 cells to TRAIL-mediated apoptosis. Moreover, following exposure to rTRAIL, caspase-3 and -8 were activated in lung explants from emphysematous subjects while being decreased in lung explants from non-emphysematous subjects. Significance of the study Alveolar sensitivity to TRAIL-mediated apoptosis is strongly increased in the emphysematous lung due to the presence of oxidative stress. This might be a new mechanism leading to increased alveolar apoptosis and persistent alveolar destruction following smoking cessation.

Melatonin resists oxidative stress-induced apoptosis in nucleus pulposus cells.

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He, Ruijun; Cui, Min; Lin, Hui; Zhao, Lei; Wang, Jiayu; Chen, Songfeng; Shao, Zengwu

2018-04-15

Intervertebral disc degeneration (IVDD) is thought to be the major cause of low back pain (LBP), which is still in lack of effective etiological treatment. Oxidative stress has been demonstrated to participate in the impairment of nucleus pulposus cells (NPCs). As the most important neuroendocrine hormone in biological clock regulation, melatonin (MLT) is also featured by good antioxidant effect. In this study, we investigated the effect and mechanisms of melatonin on oxidative stress-induced damage in rat NPCs. Cytotoxicity of H 2 O 2 and protecting effect of melatonin were analyzed with Cell Counting kit-8 (CCK-8). Cell apoptosis rate was detected by Annexin V-FITC/PI staining. DCFH-DA probe was used for the reactive oxygen species (ROS) detection. The mitochondrial membrane potential (MMP) changes were analyzed with JC-1 probe. Intracellular oxidation product and reductants were measured through enzymatic reactions. Extracellular matrix (ECM) and apoptosis associated proteins were analyzed with Western blot assays. Melatonin preserved cell viability of NPCs under oxidative stress. The apoptosis rate, ROS level and malonaldehyde (MDA) declined with melatonin. MLT/H 2 O 2 group showed higher activities of GSH and SOD. The fall of MMP receded and the expression of ECM protein increased with treatment of melatonin. The mitochondrial pathway of apoptosis was inhibited by melatonin. Melatonin alleviated the oxidative stress-induced apoptosis of NPCs. Melatonin could be a promising alternative in treatment of IVDD. Copyright © 2018 Elsevier Inc. All rights reserved.

Dose-rate effects for apoptosis and micronucleus formation in gamma-irradiated human lymphocytes

International Nuclear Information System (INIS)

Boreham, D.R.; Dolling, J.-A.; Maves, S.R.; Siwarungsun, N.; Mitchel, R.E.J.

2000-01-01

We have compared dose-rate effects for γ-radiation-induced apoptosis and micronucleus formation in human lymphocytes. Long-term assessment of individual radiation-induced apoptosis showed little intraindividual variation but significant interindividual variation. The effectiveness of radiation exposure to cause apoptosis or micronucleus formation was reduced by low-dose-rate exposures, but the reduction was apparent at different dose rates for these two end points. Micronucleus formation showed a dose-rate effect when the dose rate was lowered to 0.29 cGy/min, but there was no accompanying cell cycle delay. A further increase in the dose-rate effect was seen at 0.15 cGy/min, but was now accompanied by cell cycle delay. There was no dose-rate effect for the induction of apoptosis until the dose rate was reduced to 0.15 cGy/min, indicating that the mechanisms or signals for processing radiation-induced lesions for these two end points must be different at least in part. There appear to be two mechanisms that contribute to the dose-rate effect for micronucleus formation. One of these does not affect binucleate cell frequency and occurs at dose rates higher than that required to produce a dose-rate effect for apoptosis, and one affects binucleate cell frequency, induced only at the very low dose rate which coincidentally produces a dose-rate effect for apoptosis. Since the dose rate at which cells showed reduced apoptosis as well as a further reduction in micronucleus formation was very low, we conclude that the processing of the radiation-induced lesions that induce apoptosis, and some micronuclei, is very slow in quiescent and PHA-stimulated lymphocytes, respectively. (author)

Dose-rate effects for apoptosis and micronucleus formation in gamma-irradiated human lymphocytes

Energy Technology Data Exchange (ETDEWEB)

Boreham, D.R.; Dolling, J.-A.; Maves, S.R. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada); Siwarungsun, N. [Chulalongkorn Univ., Bangkok (Thailand); Mitchel, R.E.J. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

2000-07-01

We have compared dose-rate effects for {gamma}-radiation-induced apoptosis and micronucleus formation in human lymphocytes. Long-term assessment of individual radiation-induced apoptosis showed little intraindividual variation but significant interindividual variation. The effectiveness of radiation exposure to cause apoptosis or micronucleus formation was reduced by low-dose-rate exposures, but the reduction was apparent at different dose rates for these two end points. Micronucleus formation showed a dose-rate effect when the dose rate was lowered to 0.29 cGy/min, but there was no accompanying cell cycle delay. A further increase in the dose-rate effect was seen at 0.15 cGy/min, but was now accompanied by cell cycle delay. There was no dose-rate effect for the induction of apoptosis until the dose rate was reduced to 0.15 cGy/min, indicating that the mechanisms or signals for processing radiation-induced lesions for these two end points must be different at least in part. There appear to be two mechanisms that contribute to the dose-rate effect for micronucleus formation. One of these does not affect binucleate cell frequency and occurs at dose rates higher than that required to produce a dose-rate effect for apoptosis, and one affects binucleate cell frequency, induced only at the very low dose rate which coincidentally produces a dose-rate effect for apoptosis. Since the dose rate at which cells showed reduced apoptosis as well as a further reduction in micronucleus formation was very low, we conclude that the processing of the radiation-induced lesions that induce apoptosis, and some micronuclei, is very slow in quiescent and PHA-stimulated lymphocytes, respectively. (author)

Effects of HSP27 chaperone on THP-1 tumor cell apoptosis.

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Kaigorodova, E V; Ryazantseva, N V; Novitskii, V V; Maroshkina, A N; Belkina, M V

2012-11-01

The role of Hsp27 (heat shock protein 27) chaperone in regulation of THP-1 tumor cell apoptosis was studied. Realization of tumor cell apoptosis under conditions of in vitro culturing with Hsp27 specific inhibitor (KRIBB3) was evaluated by fluorescent microscopy with FITC-labeled annexin V and propidium iodide. Measurements of Bcl-2 family proteins (Bcl-2, Bax, Bad) in tumor cells incubated with Hsp27 inhibitor were carried out by Western blotting. Chaperone Hsp27 acted as apoptosis inhibitor in THP-1 tumor cells modulating the proportion of antiapoptotic (Bcl-2) and proapoptotic (Bax and Bad) proteins.

Survival signalling and apoptosis resistance in glioblastomas: opportunities for targeted therapeutics

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Krakstad Camilla

2010-06-01

Full Text Available Abstract Glioblastoma multiforme (GBM is the most common primary brain tumour in adults and one of the most aggressive cancers in man. Despite technological advances in surgical management, combined regimens of radiotherapy with new generation chemotherapy, the median survival for these patients is 14.6 months. This is largely due to a highly deregulated tumour genome with opportunistic deletion of tumour suppressor genes, amplification and/or mutational hyper-activation of receptor tyrosine kinase receptors. The net result of these genetic changes is augmented survival pathways and systematic defects in the apoptosis signalling machinery. The only randomised, controlled phase II trial conducted targeting the epidermal growth factor receptor (EGFR signalling with the small molecule inhibitor, erlotinib, has showed no therapeutic benefit. Survival signalling and apoptosis resistance in GBMs can be viewed as two sides of the same coin. Targeting increased survival is unlikely to be efficacious without at the same time targeting apoptosis resistance. We have critically reviewed the literature regarding survival and apoptosis signalling in GBM, and highlighted experimental, preclinical and recent clinical trials attempting to target these pathways. Combined therapies simultaneously targeting apoptosis and survival signalling defects might shift the balance from tumour growth stasis to cytotoxic therapeutic responses that might be associated with greater therapeutic benefits.

Apoptosis of nasopharyngeal carcinoma cell line (CNE-2) induced by neutron irradiation

International Nuclear Information System (INIS)

Liang Ke; He Shaoqin; Feng Yan; Tang Jinhua; Feng Qinfu; Shen Yu; Yin Weibo; Xu Guozhen; Liu Xinfan; Wang Luhua; Gao Li

1999-01-01

Objective: To study the apoptotic response of the nasopharyngeal carcinoma cell line (CNE-2) induced by neutron irradiation. Methods: CNE-2 cells were cultured as usual. Using the techniques of DNA agarose gel electrophoresis and DNA special fluorescent staining, the status of apoptosis in CNE-2 cells after neutron irradiation was detected. Results: It was shown that the apoptosis can be induced in CNE-2 cell after neutron radiation. Six hrs, after different doses of neutron (0/0.667/1.333/2.000/2.667/3.333 Gy) and X-ray 0/2/4/6/8/10 Gy) irradiation the apoptotic rates were 2.4%, 6.3%, 7.1%, 9.5%, 13.5%, 14.6% and 2.4%, 3.8%, 5.7%, 7.8%, 10.4%, 11.7%, respectively; at 48 hrs they were 18.3%, 21.5%, 22.8%, 29.3%, 34.2% and 13.7%, 17.6%, 21.3%, 25.6%, 28.9%, respectively. At 10 hrs after neutron irradiation the DNA ladder of apoptosis could be detected between 0.667-3.333 Gy doses in CNE-2 cells by DNA agarose gel electrophoresis. Conclusion: Neutron radiation can induce apoptosis in tumor cells. Compared with the X-ray, neutron induces apoptosis in larger extent than X-ray in the same condition; meanwhile, apoptosis after irradiation is dose and time dependent

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

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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.

Apoptosis and histological response of preoperative intraarterial chemotherapy infusion for colorectal carcinoma

International Nuclear Information System (INIS)

Yuan Jianhua; Hu Tingyang; Yu Wenqiang; Chen Fanghong; Luo Zuyan; Mao Yinmin; Zhao Zhongsheng; Ru Guoqing; Deng Gaoli; Dong Quanjin; Tu Shiliang

2003-01-01

Objective: To investigate apoptosis and histological response of preoperative intraarterial chemotherapy infusion for colorectal carcinoma. Methods: Fifty patients with colorectal carcinoma were treated by intraarterial infusion of anti-cancer drugs. Surgical resection of the tumor was performed 5-30 days after the intraarterial infusion (mean 12 days). The histological response was evaluated. The density and distribution of the apoptosis cells were observed by DNA nick end labelling technique. 22 biopsy specimens before the intraarterial chemotherapy and 25 normal mucosa (obtained from surgery specimen) were used as controls. Results: The total histological response rate was 100% with grade I in 20 cases, grade II in 21 cases, and grade III in 9 cases. The density of the apoptosis cells was 31.47±5.58 before and 76.69±17.12 after the intraarterial chemotherapy infusion, and 8.01±3.39 in normal mucosa, respectively. The density of the apoptosis cells after the intraarterial chemotherapy was significantly higher than that before the intraarterial chemotherapy (t=13.701, P 2 =4.696, P>0.30). The apoptosis of adenocarcinoma was significantly different with different histological response (F=7.73, P 0.05) and for adenocarcinoma with different pathological stages (F=0.001376, P>0.05). Conclusion: As an effective and safe procedure, preoperative transcatheter intraarterial chemotherapy infusion achieves a significant histological response and apoptosis in colorectal adenocarcinoma

Kinetics of apoptotic markers in exogeneously induced apoptosis of EL4 cells.

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Jessel, Robert; Haertel, Steffen; Socaciu, Carmen; Tykhonova, Svetlana; Diehl, Horst A

2002-01-01

We investigated the time-dependence of apoptotic events in EL4 cells by monitoring plasma membrane changes in correlation to DNA fragmentation and cell shrinkage. We applied three apoptosis inducers (staurosporine, tubericidine and X-rays) and we looked at various markers to follow the early-to-late apoptotic events: phospholipid translocation (identified through annexin V-fluorescein assay and propidium iodide), lipid package (via merocyanine assay), membrane fluidity and anisotropy (via fluorescent measurements), DNA fragmentation by the fluorescence-labeling test and cell size measurements. The different apoptotic inducers caused different reactions of the cells: staurosporine induced apoptosis most rapidly in a high number of cells, tubercidine triggered apoptosis only in the S phase cells, while X-rays caused a G2/M arrest and subsequently apoptosis. Loss of lipid asymmetry is promptly detectable after one hour of incubation time. The phosphatidylserine translocation, decrease of lipid package and anisotropy, and the increase of membrane fluidity appeared to be based on the same process of lipid asymmetry loss. Therefore, the DNA fragmentation and the cell shrinkage appear to be parallel and independent processes running on different time scales but which are kinetically inter-related. The results indicate different signal steps to apoptosis dependent on inducer characteristics but the kinetics of "early-to-late" apoptosis appears to be a fixed program.

Dopamine induces neutrophil apoptosis through a dopamine D-1 receptor-independent mechanism.

LENUS (Irish Health Repository)

Sookhai, S

2012-02-03

BACKGROUND: For the normal resolution of an acute inflammatory response, neutrophil (PMN) apoptosis is essential to maintain immune homeostasis and to limit inappropriate host tissue damage. A delay in PMN apoptosis has been implicated in the pathogenesis of the systemic inflammatory response syndrome (SIRS). Dopamine, a biogenic amine with known cardiovascular and neurotransmitter properties, is used in patients with SIRS to maintain hemodynamic stability. We sought to determine whether dopamine may also have immunoregulatory properties capable of influencing PMN apoptosis, function, and activation state in patients with SIRS. METHODS: PMNs were isolated from healthy volunteers and patients with SIRS and treated with varying doses of dopamine and a dopamine D-1 receptor agonist, fenoldopam. PMN apoptosis was assessed every 6 hours with use of propidium iodide DNA staining and PMN function was assessed with use of respiratory burst activity, phagocytosis ability, and CD11a, CD11b, and CD18 receptor expression as functional markers. RESULTS: There was a significant delay in PMN apotosis in patients with SIRS compared with controls. Treatment of isolated PMNs from both healthy controls and patients with SIRS with 10 and 100 mumol\\/L dopamine induced apoptosis. PMN ingestive and cytocidal capacity were both decreased in patients with SIRS compared with controls. Treatment with dopamine significantly increased phagocytic function. Fenoldopam did not induce PMN apoptosis. CONCLUSION: Our data demonstrate for the first time that dopamine induces PMN apoptosis and modulates PMN function both in healthy controls and in patients with SIRS. These results indicate that dopamine may be beneficial during SIRS through a nonhemodynamic PMN-dependent proapoptotic mechanism.

Increased radiosensitivity and radiation-induced apoptosis in SRC-3 knockout mice

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Jin Jie; Wang Yu; Xu Yang; Chen Shilei; Wang Junping; Ran Xinze; Su Yongping; Wang Jin

2014-01-01

Steroid receptor coactivator-3 (SRC-3), a multifunctional transcriptional coactivator, plays an important role in regulation of cell apoptosis in chemoresistant cancer cells. However, its role in radiation-induced apoptosis in hematopoietic cells is still unclear. In this study, we used SRC-3 knockout (SRC-3 -/- ) mice to assess the role of SRC-3 in radiation-induced hematopoietic injury in vivo. After a range of doses of irradiation, SRC-3 -/- mice exhibited lower counts of peripheral blood cells and bone marrow (BM) mononuclear cells and excessive BM depression, which resulted in a significantly higher mortality compared with wildtype mice. Moreover, BM mononuclear cells obtained from SRC-3 -/- mice showed a remarkable increase in radiation-induced apoptosis. Collectively, our data demonstrate that SRC-3 plays a role in radiation-induced apoptosis of BM hematopoietic cells. Regulation of SRC-3 might influence the radiosensitivity of hematopoietic cells, which highlights a potential therapeutic target for radiation-induced hematopoietic injury. (author)

Role of Autophagy and Apoptosis in Non-Small-Cell Lung Cancer

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Liu, Guangbo; Pei, Fen; Yang, Fengqing; Li, Lingxiao; Amin, Amit Dipak; Liu, Songnian; Buchan, J. Ross; Cho, William C.

2017-01-01

Non-small-cell lung cancer (NSCLC) constitutes 85% of all lung cancers, and is the leading cause of cancer-related death worldwide. The poor prognosis and resistance to both radiation and chemotherapy warrant further investigation into the molecular mechanisms of NSCLC and the development of new, more efficacious therapeutics. The processes of autophagy and apoptosis, which induce degradation of proteins and organelles or cell death upon cellular stress, are crucial in the pathophysiology of NSCLC. The close interplay between autophagy and apoptosis through shared signaling pathways complicates our understanding of how NSCLC pathophysiology is regulated. The apoptotic effect of autophagy is controversial as both inhibitory and stimulatory effects have been reported in NSCLC. In addition, crosstalk of proteins regulating both autophagy and apoptosis exists. Here, we review the recent advances of the relationship between autophagy and apoptosis in NSCLC, aiming to provide few insights into the discovery of novel pathogenic factors and the development of new cancer therapeutics. PMID:28208579

Attenuated apoptosis response to Fas-ligand in active ulcerative colitis

DEFF Research Database (Denmark)

Seidelin, Jakob B; Nielsen, Ole H

2008-01-01

BACKGROUND: From mainly carcinoma cell line studies, apoptosis has been thought to play a major role in the pathogenesis of ulcerative colitis (UC). Apoptosis has been suggested to be due to a Fas ligand / Fas receptor interaction, but has never been studied in cells from patients with active UC...... was subsequently reached were included. Cultures of isolated colonic crypts were obtained from biopsies and cultured for 4 to 16 hours with Fas ligand or Fas ligand and costimulation with interferon-gamma (IFN-gamma). Control experiments were performed on HT29 cells. Apoptosis was assessed by independent methods....... RESULTS: Isolated colonocytes from healthy subjects or patients with remission in UC had a dose-dependent response to Fas ligand. This response was abolished in patients with active UC (P

Nitric oxide-induced eosinophil apoptosis is dependent on mitochondrial permeability transition (mPT, JNK and oxidative stress: apoptosis is preceded but not mediated by early mPT-dependent JNK activation

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Ilmarinen-Salo Pinja

2012-08-01

Full Text Available Abstract Background Eosinophils are critically involved in the pathogenesis of asthma. Nitric oxide (NO is produced in high amounts in asthmatic lungs and has an important role as a regulator of lung inflammation. NO was previously shown to induce eosinophil apoptosis mediated via c-jun N-terminal kinase (JNK and caspases. Our aim was to clarify the cascade of events leading to NO-induced apoptosis in granulocyte macrophage-colony stimulating factor (GM-CSF-treated human eosinophils concentrating on the role of mitochondria, reactive oxygen species (ROS and JNK. Methods Apoptosis was determined by flow cytometric analysis of relative DNA content, by Annexin-V labelling and/or morphological analysis. Immunoblotting was used to study phospho-JNK (pJNK expression. Mitochondrial membrane potential was assessed by JC-1-staining and mitochondrial permeability transition (mPT by loading cells with calcein acetoxymethyl ester (AM and CoCl2 after which flow cytometric analysis was conducted. Statistical significance was calculated by repeated measures analysis of variance (ANOVA or paired t-test. Results NO-donor S-nitroso-N-acetyl-D,L-penicillamine (SNAP induced late apoptosis in GM-CSF-treated eosinophils. SNAP-induced apoptosis was suppressed by inhibitor of mPT bongkrekic acid (BA, inhibitor of JNK SP600125 and superoxide dismutase-mimetic AEOL 10150. Treatment with SNAP led to late loss of mitochondrial membrane potential. Additionally, we found that SNAP induces early partial mPT (1 h that was followed by a strong increase in pJNK levels (2 h. Both events were prevented by BA. However, these events were not related to apoptosis because SNAP-induced apoptosis was prevented as efficiently when BA was added 16 h after SNAP. In addition to the early and strong rise, pJNK levels were less prominently increased at 20–30 h. Conclusions Here we demonstrated that NO-induced eosinophil apoptosis is mediated via ROS, JNK and late mPT. Additionally

Autophagy regulates chlorpyrifos-induced apoptosis in SH-SY5Y cells

International Nuclear Information System (INIS)

Park, Jae Hyeon; Lee, Jeong Eun; Shin, In Chul; Koh, Hyun Chul

2013-01-01

Recent studies have shown that up-regulation of autophagy may be a tractable therapeutic intervention for clearing disease-causing proteins, including α-synuclein, ubiquitin, and other misfolded or aggregated proteins in pesticide-induced neurodegeneration. In a previous study, we reported that chlorpyrifos (CPF)-induced mitochondria-dependent apoptosis is mediated through reactive oxygen species in SH-SY5Y cells. In this study, we explored a novel pharmacotherapeutic approach to prevent CPF neurotoxicity involving the regulation of autophagy. We investigated the modulation of CPF-induced apoptosis according to autophagy regulation. We found that CPF induced apoptosis in SH-SY5Y cells, as demonstrated by the activation of caspase-3 and nuclear condensation. In addition, we observed that cells treated with CPF underwent autophagic cell death by monitoring the expression of LC3-II and p62. Pretreatment with the autophagy inducer rapamycin significantly enhanced the cell viability of CPF-exposed cells, and the enhancement of cell viability was partially due to alleviation of CPF-induced apoptosis via a decrease in levels of cleaved caspase-3. Specifically, rapamycin pretreatment decreased Bax and increased Bcl-2 expression in mitochondria. In addition, rapamycin significantly decreased cytochrome c release in from mitochondria into the cytosol. However, pretreatment of cells with the autophagy inhibitor, 3-methyladenine (3MA), remarkably increased CPF toxicity in these cells; this with correlated with increased expression of Bax and decreased expression of Bcl-2 in mitochondria. Our results suggest that CPF-induced cytotoxicity is modified by autophagy regulation and that rapamycin protects against CPF-induced apoptosis by enhancing autophagy. Pharmacologic induction of autophagy by rapamycin may be a useful treatment strategy in neurodegenerative disorders. - Highlights: ► Chlorpyrifos (CPF) is cytotoxic to SH-SY5Y cells ► CPF-induced cytotoxicity is mediated by

Autophagy regulates chlorpyrifos-induced apoptosis in SH-SY5Y cells

Energy Technology Data Exchange (ETDEWEB)

Park, Jae Hyeon [Department of Pharmacology, College of Medicine, Hanyang University (Korea, Republic of); Hanyang Biomedical Research Institute, Seoul (Korea, Republic of); Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul (Korea, Republic of); Lee, Jeong Eun [Department of Pharmacology, College of Medicine, Hanyang University (Korea, Republic of); Hanyang Biomedical Research Institute, Seoul (Korea, Republic of); Shin, In Chul [Department of Pharmacology, College of Medicine, Hanyang University (Korea, Republic of); Koh, Hyun Chul, E-mail: hckoh@hanyang.ac.kr [Department of Pharmacology, College of Medicine, Hanyang University (Korea, Republic of); Hanyang Biomedical Research Institute, Seoul (Korea, Republic of); Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul (Korea, Republic of)

2013-04-01

Recent studies have shown that up-regulation of autophagy may be a tractable therapeutic intervention for clearing disease-causing proteins, including α-synuclein, ubiquitin, and other misfolded or aggregated proteins in pesticide-induced neurodegeneration. In a previous study, we reported that chlorpyrifos (CPF)-induced mitochondria-dependent apoptosis is mediated through reactive oxygen species in SH-SY5Y cells. In this study, we explored a novel pharmacotherapeutic approach to prevent CPF neurotoxicity involving the regulation of autophagy. We investigated the modulation of CPF-induced apoptosis according to autophagy regulation. We found that CPF induced apoptosis in SH-SY5Y cells, as demonstrated by the activation of caspase-3 and nuclear condensation. In addition, we observed that cells treated with CPF underwent autophagic cell death by monitoring the expression of LC3-II and p62. Pretreatment with the autophagy inducer rapamycin significantly enhanced the cell viability of CPF-exposed cells, and the enhancement of cell viability was partially due to alleviation of CPF-induced apoptosis via a decrease in levels of cleaved caspase-3. Specifically, rapamycin pretreatment decreased Bax and increased Bcl-2 expression in mitochondria. In addition, rapamycin significantly decreased cytochrome c release in from mitochondria into the cytosol. However, pretreatment of cells with the autophagy inhibitor, 3-methyladenine (3MA), remarkably increased CPF toxicity in these cells; this with correlated with increased expression of Bax and decreased expression of Bcl-2 in mitochondria. Our results suggest that CPF-induced cytotoxicity is modified by autophagy regulation and that rapamycin protects against CPF-induced apoptosis by enhancing autophagy. Pharmacologic induction of autophagy by rapamycin may be a useful treatment strategy in neurodegenerative disorders. - Highlights: ► Chlorpyrifos (CPF) is cytotoxic to SH-SY5Y cells ► CPF-induced cytotoxicity is mediated by

Rapamycin treatment is associated with an increased apoptosis rate in experimental vein grafts.

Science.gov (United States)

Schachner, Thomas; Oberhuber, Alexander; Zou, Yping; Tzankov, Alexandar; Ott, Harald; Laufer, Günther; Bonatti, Johannes

2005-02-01

Rapamycin is an immunosuppressive agent with marked antiproliferative properties and is effective in reducing in stent restenosis and vein graft neointimal hyperplasia. Apoptosis is one mechanism counterbalancing cellular proliferation. We therefore investigated the role of apoptosis in rapamycin treated vein grafts in a mouse model. C57BL6J mice underwent interposition of the inferior vena cava from isogenic donor mice into the common carotid artery using a cuff technique. In the treatment group 200 microg of rapamycin were applied locally in pluronic gel. The control group did not receive local treatment. Vein grafts were harvested at 4 weeks postoperatively and underwent morphometric analysis as well as immunohistochemical analysis for apoptosis (TUNEL). In grafted veins without treatment (controls) neointimal thickness was 50 (12-58) microm at 4 weeks postoperatively. In 200 microg rapamycin treated grafts the neointimal thickness was 17 (5-55) microm. Rapamycin treated vein grafts showed a significantly increased rate of apoptosis in the adventitia as compared with controls (P=0.032). In the neointima the apoptosis rate was lower in both groups with no significant difference between rapamycin treated grafts and controls. We conclude that treatment of experimental vein grafts with rapamycin is associated with an increased apoptosis rate in the vascular wall and a trend towards reduction of neointimal hyperplasia. These results suggest that apoptosis may be a beneficial antiproliferative component for the treatment of vein graft disease.

DR3 regulation of apoptosis of naive T-lymphocytes in children with acute infectious mononucleosis.

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Filatova, Elena Nikolaevna; Anisenkova, Elena Viktorovna; Presnyakova, Nataliya Borisovna; Utkin, Oleg Vladimirovich

2016-09-01

Acute infectious mononucleosis (AIM) is a widespread viral disease that mostly affects children. Development of AIM is accompanied by a change in the ratio of immune cells. This is provided by means of different biological processes including the regulation of apoptosis of naive T-cells. One of the potential regulators of apoptosis of T-lymphocytes is a death receptor 3 (DR3). We have studied the role of DR3 in the regulation of apoptosis of naive CD4 + (nTh) and CD8 + (nCTL) T-cells in healthy children and children with AIM. In healthy children as well as in children with AIM, the activation of DR3 is accompanied by inhibition of apoptosis of nTh. In healthy children, the stimulation of DR3 resulted in the increase in apoptosis of nCTL. On the contrary, in children with AIM, the level of apoptosis of nCTL decreased after DR3 activation, which is a positive contribution to the antiviral immune response. In children with AIM, nCTL are characterized by reduced level of apoptosis as compared with healthy children. These results indicate that DR3 can be involved in the reduction of sensitivity of nCTL to apoptosis in children with AIM.

Surfactant protein D delays Fas- and TRAIL-mediated extrinsic pathway of apoptosis in T cells.

Science.gov (United States)

Djiadeu, Pascal; Kotra, Lakshmi P; Sweezey, Neil; Palaniyar, Nades

2017-05-01

Only a few extracellular soluble proteins are known to modulate apoptosis. We considered that surfactant-associated protein D (SP-D), an innate immune collectin present on many mucosal surfaces, could regulate apoptosis. Although SP-D is known to be important for immune cell homeostasis, whether SP-D affects apoptosis is unknown. In this study we aimed to determine the effects of SP-D on Jurkat T cells and human T cells dying by apoptosis. Here we show that SP-D binds to Jurkat T cells and delays the progression of Fas (CD95)-Fas ligand and TRAIL-TRAIL receptor induced, but not TNF-TNF receptor-mediated apoptosis. SP-D exerts its effects by reducing the activation of initiator caspase-8 and executioner caspase-3. SP-D also delays the surface exposure of phosphatidylserine. The effect of SP-D was ablated by the presence of caspase-8 inhibitor, but not by intrinsic pathway inhibitors. The binding ability of SP-D to dying cells decreases during the early stages of apoptosis, suggesting the release of apoptotic cell surface targets during apoptosis. SP-D also delays FasL-induced death of primary human T cells. SP-D delaying the progression of the extrinsic pathway of apoptosis could have important implications in regulating immune cell homeostasis at mucosal surfaces.

Apoptosis of rats’ cardiomyocytes after chronic energy drinks consumption

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Slawinski Miroslaw Aleksander

2018-03-01

Full Text Available Energy drinks (ED are beverages containing caffeine, taurine, vitamins, herbal extracts, and sugar or sweeteners. They are marketed as capable of improving stamina, athletic performance and concentration, moreover, as serving as a source of energy. Still, there are very few papers describing the impact of ED on cell biology – including cell apoptosis within tissues. Therefore, in our study, we assessed the symptoms of rat cardiomyocytes apoptosis after 8 weeks consumption of ED.

Apoptosis and T cell depletion during feline infectious peritonitis

OpenAIRE

Horzinek, M.C.; Haagmans, B.L.; Egberink, H.F.

1996-01-01

Cats that have succumbed to feline infectious peritonitis, an immune- mediated disease caused by variants of feline coronaviruses, show apoptosis and T-cell depletion in their lymphoid organs. The ascitic fluid that develops in the course of the condition causes apoptosis in vitro but only in activated T cells. Since feline infectious peritonitis virus does not infect T cells, and viral proteins did not inhibit T-cell proliferation, we postulate that soluble mediators released during the infe...

Isolation and identification of gene mediating radiation-induced apoptosis in human leukemia U937 cells

International Nuclear Information System (INIS)

Tong Xin; Luo Ying; Dong Yan; Sun Zhixian

1998-01-01

Objective: Increasing evidences suggest that Caspase family proteases play an important role in the effector mechanism of apoptotic cell death. Radiation (IR) can induce apoptosis in tumor cells, so it is very important to isolate and identify the member of the Caspase family proteases involved in IR-induced apoptosis, and this would contribute to the understanding of the mechanism responsible for apoptosis execution. Methods: A PCR approach to isolate genes for IR-induced apoptosis was developed. The approach used degenerated oligonucleotide encoding the highly conserved peptides that were present in all known Caspases. Results: Protease inhibitors special for Caspases could block the apoptotic cell death caused by IR, and Caspase-3 was isolated from irradiated human leukemia U937 cells. Conclusion: Caspases involve in IR-induced apoptosis, and Caspase-3 is the pivotal element of IR-induced apoptosis

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

International Nuclear Information System (INIS)

Pauklin, Siim; Kristjuhan, Arnold; Maimets, Toivo; Jaks, Viljar

2005-01-01

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

Roles of acid sphingomyelinase activation in neuronal cells apoptosis induced by microwave irradiation

International Nuclear Information System (INIS)

Zhang Lei; Xu Shangcheng; Zhang Guangbin; Yu Zhengping

2009-01-01

The present study is to examine the effect of microwave on acid sphingomyelinase (ASM) activity and expression, and to explore the role of ASM activation in neuronal cells apoptosis induced by microwave irradiation. Primary cultured hippocampal neurons were irradiated by 30 W/cm 2 microwave for 10 min, and ASM activity assay was used to investigate ASM activity alteration. RT-PCR and western blot were used to detect ASM mRNA and protein expression respectively. Apoptosis was observed by Hoechst 33342 fluorescence staining. ASM specific inhibitor imipramine was applied to inhibit ASM activation. It has been found that apoptosis rate of primary cultured hippocampal neurons increased significantly after microwave irradiation. ASM was activated while ASM mRNA and protein expression were upregulated in neurons after microwave irradiation. Pretreatment with imipramine could reverse neuronal apoptosis induced by microwave irradiation. Results show that microwave irradiation causes increment of ASM activation and expression and ASM activation is involved in microwave induced neuronal apoptosis. (authors)

Propolis augments apoptosis induced by butyrate via targeting cell survival pathways.

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Eric Drago

Full Text Available Diet is one of the major lifestyle factors affecting incidence of colorectal cancer (CC, and despite accumulating evidence that numerous diet-derived compounds modulate CC incidence, definitive dietary recommendations are not available. We propose a strategy that could facilitate the design of dietary supplements with CC-preventive properties. Thus, nutrient combinations that are a source of apoptosis-inducers and inhibitors of compensatory cell proliferation pathways (e.g., AKT signaling may produce high levels of programmed death in CC cells. Here we report the combined effect of butyrate, an apoptosis inducer that is produced through fermentation of fiber in the colon, and propolis, a honeybee product, on CC cells. We established that propolis increases the apoptosis of CC cells exposed to butyrate through suppression of cell survival pathways such as the AKT signaling. The programmed death of CC cells by combined exposure to butyrate and propolis is further augmented by inhibition of the JNK signaling pathway. Analyses on the contribution of the downstream targets of JNK signaling, c-JUN and JAK/STAT, to the apoptosis of butyrate/propolis-treated CC cells ascertained that JAK/STAT signaling has an anti-apoptotic role; whereas, the role of cJUN might be dependent upon regulatory cell factors. Thus, our studies ascertained that propolis augments apoptosis of butyrate-sensitive CC cells and re-sensitizes butyrate-resistant CC cells to apoptosis by suppressing AKT signaling and downregulating the JAK/STAT pathway. Future in vivo studies should evaluate the CC-preventive potential of a dietary supplement that produces high levels of colonic butyrate, propolis, and diet-derived JAK/STAT inhibitors.

Hot water extract of Chlorella vulgaris induced DNA damage and apoptosis

Science.gov (United States)

Yusof, Yasmin Anum Mohd; Md. Saad, Suhana; Makpol, Suzana; Shamaan, Nor Aripin; Ngah, Wan Zurinah Wan

2010-01-01

OBJECTIVES: The aim of this study was to determine the antiproliferative and apoptotic effects of hot water extracts of Chlorella vulgaris on hepatoma cell line HepG2. INTRODUCTION: The search for food and spices that can induce apoptosis in cancer cells has been a major study interest in the last decade. Chlorella vulgaris, a unicellular green algae, has been reported to have antioxidant and anti‐cancer properties. However, its chemopreventive effects in inhibiting the growth of cancer cells have not been studied in great detail. METHODS: HepG2 liver cancer cells and WRL68 normal liver cells were treated with various concentrations (0‐4 mg/ml) of hot water extract of C. vulgaris after 24 hours incubation. Apoptosis rate was evaluated by TUNEL assay while DNA damage was assessed by Comet assay. Apoptosis proteins were evaluated by Western blot analysis. RESULTS: Chlorella vulgaris decreased the number of viable HepG2 cells in a dose dependent manner (p Chlorella vulgaris tested. Evaluation of apoptosis by TUNEL assay showed that Chlorella vulgaris induced a higher apoptotic rate (70%) in HepG2 cells compared to normal liver cells, WRL68 (15%). Western blot analysis showed increased expression of pro‐ apoptotic proteins P53, Bax and caspase‐3 in the HepG2 cells compared to normal liver cells WRL68, and decreased expression of the anti‐apoptotic protein Bcl‐2. CONCLUSIONS: Chlorella vulgaris may have anti‐cancer effects by inducing apoptosis signaling cascades via an increased expression of P53, Bax and caspase‐3 proteins and through a reduction of Bcl‐2 protein, which subsequently lead to increased DNA damage and apoptosis. PMID:21340229

Apoptosis in mouse fetal and neonatal oocytes during meiotic prophase one

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Hartshorne Geraldine M

2007-07-01

Full Text Available Abstract Background The vast majority of oocytes formed in the fetal ovary do not survive beyond birth. Possible reasons for their loss include the elimination of non-viable genetic constitutions arising through meiosis, however, the precise relationship between meiotic stages and prenatal apoptosis of oocytes remains elusive. We studied oocytes in mouse fetal and neonatal ovaries, 14.5–21 days post coitum, to examine the relationship between oocyte development and programmed cell death during meiotic prophase I. Results Microspreads of fetal and neonatal ovarian cells underwent immunocytochemistry for meiosis- and apoptosis-related markers. COR-1 (meiosis-specific highlighted axial elements of the synaptonemal complex and allowed definitive identification of the stages of meiotic prophase I. Labelling for cleaved poly-(ADP-ribose polymerase (PARP-1, an inactivated DNA repair protein, indicated apoptosis. The same oocytes were then labelled for DNA double strand breaks (DSBs using TUNEL. 1960 oocytes produced analysable results. Oocytes at all stages of meiotic prophase I stained for cleaved PARP-1 and/or TUNEL, or neither. Oocytes with fragmented (19.8% or compressed (21.2% axial elements showed slight but significant differences in staining for cleaved PARP-1 and TUNEL to those with intact elements. However, fragmentation of axial elements alone was not a good indicator of cell demise. Cleaved PARP-1 and TUNEL staining were not necessarily coincident, showing that TUNEL is not a reliable marker of apoptosis in oocytes. Conclusion Our data indicate that apoptosis can occur throughout meiotic prophase I in mouse fetal and early postnatal oocytes, with greatest incidence at the diplotene stage. Careful selection of appropriate markers for oocyte apoptosis is essential.

Can vitamin d suppress endothelial cells apoptosis in multiple sclerosis patients?

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Dehghani, Leila; Meamar, Rokhsareh; Etemadifar, Masoud; Sheshde, Zahra Dehghani; Shaygannejad, Vahid; Sharifkhah, Mostafa; Tahani, Soheil

2013-05-01

Multiple sclerosis (MS) is an autoimmune disease of central nerves system, in which neurological disabilities occur in young adults. Despite increasing number of studies on MS, some aspects of this disorder are still unclear. In the previous studies, it has been proven that there is direct relation between MS incidence and vitamin D deficiency. Thereby, strong evidence in MS pathogenesis suggests that endothelial cells (EC) could be harmed in MS. In addition, functional changes in EC and macrovascular injuries lead blood-brain barrier disruption in MS. Current study is the first investigation to elucidate positive influences of vitamin D against EC apoptosis in MS. Human umbilical vein endothelial cells (HUVECs) were cultured and then treated with sera from patients with active MS (in relapse) and sera from healthy volunteer participants as control group (each group n=15). 3-(4,5-dimethylthiazol-2-yl)-5- (3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) assay for cell surveillance and cell-death detection kit for evaluating apoptosis were used in this study. There was a significant decrease in apoptosis rate by the serum of patients, just when 1,25(OH)2D3 applied before treating HUVECs with sera from active MS (in relapse). Furthermore, the cells surveillance increased markedly with the presence of 1,25(OH)(2)D(3) in culture, too. Withregard to increment in EC apoptosis rate, which treated by the sera from MS patients and decrement in apoptosis rate by the presence of vitamin D in culture media, it could be proposed that vitamin D pre-treatment can be used for MS patients, due to its beneficial effects on protecting EC apoptosis.

Mechanisms of methicillin-resistant Staphylococcus aureus pneumonia-induced intestinal epithelial apoptosis.

Science.gov (United States)

Perrone, Erin E; Jung, Enjae; Breed, Elise; Dominguez, Jessica A; Liang, Zhe; Clark, Andrew T; Dunne, W Michael; Burd, Eileen M; Coopersmith, Craig M

2012-07-01

Methicillin-resistant Staphylococcus aureus (MRSA) pneumonia-induced sepsis is a common cause of morbidity in the intensive care unit. Although pneumonia is initiated in the lungs, extrapulmonary manifestations occur commonly. In light of the key role the intestine plays in the pathophysiology of sepsis, we sought to determine whether MRSA pneumonia induces intestinal injury. FVB/N mice were subjected to MRSA or sham pneumonia and killed 24 h later. Septic animals had a marked increase in intestinal epithelial apoptosis by both hematoxylin-eosin and active caspase 3 staining. Methicillin-resistant S. aureus-induced intestinal apoptosis was associated with an increase in the expression of the proapoptotic proteins Bid and Bax and the antiapoptotic protein Bcl-xL in the mitochondrial pathway. In the receptor-mediated pathway, MRSA pneumonia induced an increase in Fas ligand but decreased protein levels of Fas, FADD, pFADD, TNF-R1, and TRADD. To assess the functional significance of these changes, MRSA pneumonia was induced in mice with genetic manipulations in proteins in either the mitochondrial or receptor-mediated pathways. Both Bid-/- mice and animals with intestine-specific overexpression of Bcl-2 had decreased intestinal apoptosis compared with wild-type animals. In contrast, Fas ligand-/- mice had no alterations in apoptosis. To determine if these findings were organism-specific, similar experiments were performed in mice subjected to Pseudomonas aeruginosa pneumonia. Pseudomonas aeruginosa induced gut apoptosis, but unlike MRSA, this was associated with increased Bcl-2 and TNF-R1 and decreased Fas. Methicillin-resistant S. aureus pneumonia thus induces organism-specific changes in intestinal apoptosis via changes in both the mitochondrial and receptor-mediated pathways, although the former may be more functionally significant.

Apoptosis-promoted tumorigenesis: γ-irradiation-induced thymic lymphomagenesis requires Puma-driven leukocyte death

OpenAIRE

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

2010-01-01

Although tumor development requires impaired apoptosis, we describe a novel paradigm of apoptosis-dependent tumorigenesis. Because DNA damage triggers apoptosis through p53-mediated induction of BH3-only proteins Puma and Noxa, we explored their roles in γ-radiation-induced thymic lymphomagenesis. Surprisingly, whereas Noxa loss accelerated it, Puma loss ablated tumorigenesis. Tumor suppression by Puma deficiency reflected its protection of leukocytes from γ-irradiation-induced death, because...

Apoptosis-like yeast cell death in response to DNA damage and replication defects

Energy Technology Data Exchange (ETDEWEB)

Burhans, William C.; Weinberger, Martin; Marchetti, Maria A.; Ramachandran, Lakshmi; D' Urso, Gennaro; Huberman, Joel A

2003-11-27

In budding (Saccharomyces cerevisiae) and fission (Schizosaccharomyces pombe) yeast and other unicellular organisms, DNA damage and other stimuli can induce cell death resembling apoptosis in metazoans, including the activation of a recently discovered caspase-like molecule in budding yeast. Induction of apoptotic-like cell death in yeasts requires homologues of cell cycle checkpoint proteins that are often required for apoptosis in metazoan cells. Here, we summarize these findings and our unpublished results which show that an important component of metazoan apoptosis recently detected in budding yeast - reactive oxygen species (ROS) - can also be detected in fission yeast undergoing an apoptotic-like cell death. ROS were detected in fission and budding yeast cells bearing conditional mutations in genes encoding DNA replication initiation proteins and in fission yeast cells with mutations that deregulate cyclin-dependent kinases (CDKs). These mutations may cause DNA damage by permitting entry of cells into S phase with a reduced number of replication forks and/or passage through mitosis with incompletely replicated chromosomes. This may be relevant to the frequent requirement for elevated CDK activity in mammalian apoptosis, and to the recent discovery that the initiation protein Cdc6 is destroyed during apoptosis in mammals and in budding yeast cells exposed to lethal levels of DNA damage. Our data indicate that connections between apoptosis-like cell death and DNA replication or CDK activity are complex. Some apoptosis-like pathways require checkpoint proteins, others are inhibited by them, and others are independent of them. This complexity resembles that of apoptotic pathways in mammalian cells, which are frequently deregulated in cancer. The greater genetic tractability of yeasts should help to delineate these complex pathways and their relationships to cancer and to the effects of apoptosis-inducing drugs that inhibit DNA replication.

Apoptosis-like yeast cell death in response to DNA damage and replication defects

International Nuclear Information System (INIS)

Burhans, William C.; Weinberger, Martin; Marchetti, Maria A.; Ramachandran, Lakshmi; D'Urso, Gennaro; Huberman, Joel A.

2003-01-01

In budding (Saccharomyces cerevisiae) and fission (Schizosaccharomyces pombe) yeast and other unicellular organisms, DNA damage and other stimuli can induce cell death resembling apoptosis in metazoans, including the activation of a recently discovered caspase-like molecule in budding yeast. Induction of apoptotic-like cell death in yeasts requires homologues of cell cycle checkpoint proteins that are often required for apoptosis in metazoan cells. Here, we summarize these findings and our unpublished results which show that an important component of metazoan apoptosis recently detected in budding yeast - reactive oxygen species (ROS) - can also be detected in fission yeast undergoing an apoptotic-like cell death. ROS were detected in fission and budding yeast cells bearing conditional mutations in genes encoding DNA replication initiation proteins and in fission yeast cells with mutations that deregulate cyclin-dependent kinases (CDKs). These mutations may cause DNA damage by permitting entry of cells into S phase with a reduced number of replication forks and/or passage through mitosis with incompletely replicated chromosomes. This may be relevant to the frequent requirement for elevated CDK activity in mammalian apoptosis, and to the recent discovery that the initiation protein Cdc6 is destroyed during apoptosis in mammals and in budding yeast cells exposed to lethal levels of DNA damage. Our data indicate that connections between apoptosis-like cell death and DNA replication or CDK activity are complex. Some apoptosis-like pathways require checkpoint proteins, others are inhibited by them, and others are independent of them. This complexity resembles that of apoptotic pathways in mammalian cells, which are frequently deregulated in cancer. The greater genetic tractability of yeasts should help to delineate these complex pathways and their relationships to cancer and to the effects of apoptosis-inducing drugs that inhibit DNA replication

Iodinated contrast media induce neutrophil apoptosis through a mitochondrial and caspase mediated pathway.

LENUS (Irish Health Repository)

Fanning, N F

2012-02-03

Iodinated contrast media (ICM) can induce apoptosis (programmed cell death) in renal, myocardial and endothelial cells. Following intravascular injection, circulating immune cells are exposed to high concentrations of ICM. As neutrophils constitutively undergo apoptosis we hypothesized that ICM may adversely affect neutrophil survival. Our aim was to investigate the effect of ICM on neutrophil apoptosis. Neutrophils were isolated from healthy subjects and cultured in vitro with ionic (diatrizoate and ioxaglate) and non-ionic (iohexol and iotrolan) ICM. The effect of ICM on neutrophil apoptosis in both unstimulated and lipopolysaccharide-stimulated neutrophils was determined by annexin V flow cytometry. The influence of physicochemical properties of the different ICM on apoptosis of neutrophils was also studied. We further investigated the effects of ICM on key intracellular signal pathways, including p38 mitogen-activated protein kinase (MAPK) by Western blotting, and mitochondrial depolarization and caspase activity by flow cytometry. Isoiodine concentrations (20 mg ml(-1)) of ionic (diatrizoate 69.6+\\/-2.9%; ioxaglate 58.9+\\/-2.0%) and non-ionic (iohexol 57.3+\\/-2.9%; iotrolan 57.1+\\/-2.6%) ICM significantly induced neutrophil apoptosis over control levels (47.7+\\/-1.4%). The apoptotic effect of ICM was influenced by their chemical structure, with ionic ICM having a more significant (p<0.01) apoptotic effect than non-ionic ICM (p<0.05). Furthermore, ICM reversed the anti-apoptotic effect of lipopolysaccharide (1000 ng ml(-1)) treated neutrophils to control levels (23.0+\\/-3.5% to 61.2+\\/-5.3%; n=4; p<0.05). These agents induce apoptosis through a p38 MAPK independent pathway that results in mitochondrial depolarization, and is dependent on caspase activation. As neutrophils play a central role in host response to infection and injury, ICM, through induction of neutrophil apoptosis, could have a significant deleterious effect on host immune defence and

Heme oxygenase-1 prevents non-alcoholic steatohepatitis through suppressing hepatocyte apoptosis in mice

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Fu Na

2010-10-01

Full Text Available Abstract Objective Heme oxygenase-1 (HO-1, the rate-limiting enzyme in heme catabolism, has been reported to have potential antioxidant properties. However, the role of HO-1 on hepatocyte apoptosis remains unclear. We aim to elucidate the effects of HO-1 on oxidative stress related hepatocellular apoptosis in nutritional steatohepatitis in mice. Methods C57BL/6J mice were fed with methionine-choline deficient (MCD diet for four weeks to induce hepatic steatohepatitis. HO-1 chemical inducer (hemin, HO-1 chemical inhibitor zinc protoporphyrin IX (ZnPP-IX and/or adenovirus carrying HO-1 gene (Ad-HO-1 were administered to mice, respectively. Hepatocyte apoptosis was evaluated by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL assay, the mRNA and protein expression of apoptosis related genes were assayed by quantitative real-time PCR and Western blot. Results Hepatocyte signs of oxidative related apoptotic injury were presented in mice fed with MCD diet for 4 weeks. Induction of HO-1 by hemin or Ad-HO-1 significantly attenuated the severity of liver histology, which was associated with decreased hepatic lipid peroxidation content, reduced number of apoptotic cells by TUNEL staining, down-regulated expression of pro-apoptosis related genes including Fas/FasL, Bax, caspase-3 and caspase-9, reduced expression of cytochrome p4502E1 (CYP2E1, inhibited cytochrome c (Cyt-c release, and up-regulated expression of anti-apoptosis gene Bcl-2. Whereas, inhibition of HO-1 by ZnPP-IX caused oxidative stress related hepatic injury, which concomitant with increased number of TUNEL positive cells and up-regulated expression of pro-apoptosis related genes. Conclusions The present study provided evidences for the protective role of HO-1 in preventing nutritional steatohepatitis through suppressing hepatocyte apoptosis in mice.

Induction of apoptosis by eugenol in human breast cancer cells

International Nuclear Information System (INIS)

Vidhya, N.; Niranjali Devaraj, S.

2011-01-01

In the present study, potential anticancer effect of eugenol on inhibition of cell proliferation and induction of apoptosis in human MCF-7 breast cancer cells was investigated. Induction of cell death by eugenol was evaluated following MTT assay and monitoring lactate dehydrogenase released into the culture medium for cell viability and cytotoxicity, giemsa staining for morphological alterations, fluorescence microscopy analysis of cells using ethidium bromide and acridine orange and quantitation of DNA fragments for induction of apoptosis. Effect of eugenol on intracellular redox status of the human breast cancer cells was assessed by determining the level of glutathione and lipid peroxidation products (TBARS). Eugenol treatment inhibited the growth and proliferation of human MCF-7 breast cancer cells through induction of cell death, which was dose and time dependent. Microscopic examination of eugenol treated cells showed cell shrinkage, membrane blebbing and apoptotic body formation. Further, eugenol treatment also depleted the level of intracellular glutathione and increased the level of lipid peroxidation. The dose dependent increase in the percentage of apoptotic cells and DNA fragments suggested that apoptosis was involved in eugenol induced cell death and apoptosis might have played a role in the chemopreventive action of eugenol. (author)

Effects of biodegradable Mg–6Zn alloy extracts on apoptosis of intestinal epithelial cells

International Nuclear Information System (INIS)

Wang Zhanhui; Yan Jun; Li Jianan; Zheng Qi; Wang Zhigang; Zhang Xiaonong; Zhang Shaoxiang

2012-01-01

Highlights: ► We evaluated the effects of Mg–6Zn alloys on apoptosis of IEC-6 cells. ► The apoptosis was evaluated by investigating the expression of caspase-1 and Bcl-2. ► The IEC-6 cells displayed better cell functions in 60% or 20% extract. ► The conspicuous alkaline environment is disadvantageous to apoptosis of IEC cells. ► The excessive Mg concentration is disadvantageous to apoptosis of IEC-6 cells. - Abstract: In this study, intestinal epithelial cells (IEC)-6 were cultured in different concentration extracts of Mg–6Zn alloys for different time periods. To achieve a total of three concentrations (100%, 60% and 20% concentration), the extracts were serially diluted with Dulbecco's modified Eagle medium High Glucose to observe a dose–response relationship. We studied the indirect effects of Mg–6Zn alloys on IEC-6 cells apoptosis. The apoptosis of IEC-6 cells was measured using flow cytometry. And the apoptosis of IEC-6 cells was evaluated by investigating the expression of caspase-1and Bcl-2 using real-time polymerase chain reaction (PCR) and Western blotting tests. It was found that the levels of apoptosis in IEC-6 cells cultured in 100% Mg–6Zn alloy extracts were significantly higher than those in 60% and 20% extracts; the 100% extract can down-regulate expression of Bcl-2 after culture. The in vitro results indicated that the conspicuous alkaline environment and excessive Mg concentration, even Zn concentration caused by rapid corrosion of Mg–6Zn alloys promote IEC-6 cells apoptosis, although further experiments will be necessary to formally prove our conclusions. Therefore, the adjustment of the degradation rate is needed for using Mg–Zn alloy as a surgical suture material.

Isthmin targets cell-surface GRP78 and triggers apoptosis via induction of mitochondrial dysfunction.

Science.gov (United States)

Chen, M; Zhang, Y; Yu, V C; Chong, Y-S; Yoshioka, T; Ge, R

2014-05-01

Isthmin (ISM) is a secreted 60-kDa protein that potently induces endothelial cell (EC) apoptosis. It suppresses tumor growth and angiogenesis in mice when stably overexpressed in cancer cells. Although αvβ5 integrin serves as a low-affinity receptor for ISM, the mechanism by which ISM mediates antiangiogenesis and apoptosis in ECs remain to be fully resolved. In this work, we report the identification of cell-surface glucose-regulated protein 78 kDa (GRP78) as a high-affinity receptor for ISM (Kd=8.6 nM). We demonstrated that ISM-GRP78 interaction triggers apoptosis not only in activated ECs but also in cancer cells expressing high level of cell-surface GRP78. Normal cells and benign tumor cells tend to express low level of cell-surface GRP78 and are resistant to ISM-induced apoptosis. Upon binding to GRP78, ISM is internalized into ECs through clathrin-dependent endocytosis that is essential for its proapoptotic activity. Once inside the cell, ISM co-targets with GRP78 to mitochondria where it interacts with ADP/ATP carriers on the inner membrane and blocks ATP transport from mitochondria to cytosol, thereby causing apoptosis. Hence, ISM is a novel proapoptotic ligand that targets cell-surface GRP78 to trigger apoptosis by inducing mitochondrial dysfunction. The restricted and high-level expression of cell-surface GRP78 on cancer cells and cancer ECs make them uniquely susceptible to ISM-targeted apoptosis. Indeed, systemic delivery of recombinant ISM potently suppressed subcutaneous 4T1 breast carcinoma and B16 melanoma growth in mice by eliciting apoptosis selectively in the cancer cells and cancer ECs. Together, this work reveals a novel ISM-GRP78 apoptosis pathway and demonstrates the potential of ISM as a cancer-specific and dual-targeting anticancer agent.

Isthmin targets cell-surface GRP78 and triggers apoptosis via induction of mitochondrial dysfunction

Science.gov (United States)

Chen, M; Zhang, Y; Yu, V C; Chong, Y-S; Yoshioka, T; Ge, R

2014-01-01

Isthmin (ISM) is a secreted 60-kDa protein that potently induces endothelial cell (EC) apoptosis. It suppresses tumor growth and angiogenesis in mice when stably overexpressed in cancer cells. Although αvβ5 integrin serves as a low-affinity receptor for ISM, the mechanism by which ISM mediates antiangiogenesis and apoptosis in ECs remain to be fully resolved. In this work, we report the identification of cell-surface glucose-regulated protein 78 kDa (GRP78) as a high-affinity receptor for ISM (Kd=8.6 nM). We demonstrated that ISM-GRP78 interaction triggers apoptosis not only in activated ECs but also in cancer cells expressing high level of cell-surface GRP78. Normal cells and benign tumor cells tend to express low level of cell-surface GRP78 and are resistant to ISM-induced apoptosis. Upon binding to GRP78, ISM is internalized into ECs through clathrin-dependent endocytosis that is essential for its proapoptotic activity. Once inside the cell, ISM co-targets with GRP78 to mitochondria where it interacts with ADP/ATP carriers on the inner membrane and blocks ATP transport from mitochondria to cytosol, thereby causing apoptosis. Hence, ISM is a novel proapoptotic ligand that targets cell-surface GRP78 to trigger apoptosis by inducing mitochondrial dysfunction. The restricted and high-level expression of cell-surface GRP78 on cancer cells and cancer ECs make them uniquely susceptible to ISM-targeted apoptosis. Indeed, systemic delivery of recombinant ISM potently suppressed subcutaneous 4T1 breast carcinoma and B16 melanoma growth in mice by eliciting apoptosis selectively in the cancer cells and cancer ECs. Together, this work reveals a novel ISM-GRP78 apoptosis pathway and demonstrates the potential of ISM as a cancer-specific and dual-targeting anticancer agent. PMID:24464222

Herbal Medicine as Inducers of Apoptosis in Cancer Treatment

Directory of Open Access Journals (Sweden)

Elham Safarzadeh

2014-12-01

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

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.

Apoptosis detection in histological sections

Czech Academy of Sciences Publication Activity Database

Matalová, Eva; Dubská, Lenka; Míšek, Ivan

2003-01-01

Roč. 72, č. 7 (2003), s. 18-19 ISSN 0001-7213. [Congress of the European Association of Veterinary Anatomists/24./. 21.07.2002-25.07.2002, Brno] R&D Projects: GA ČR GP204/02/P112 Institutional research plan: CEZ:AV0Z5045916 Keywords : apoptosis Subject RIV: FF - HEENT, Dentistry

HIV-1 protease-induced apoptosis

Czech Academy of Sciences Publication Activity Database

Rumlová, Michaela; Křížová, Ivana; Keprová, Alena; Hadravová, Romana; Doležal, Michal; Strohalmová, Karolína; Pichová, Iva; Hájek, Miroslav; Ruml, T.

2014-01-01

Roč. 11, May 20 (2014), 37/1-37/15 ISSN 1742-4690 R&D Projects: GA ČR GA204/09/1388 Institutional support: RVO:61388963 Keywords : HIV protease * BCA3 * AKIP-1 * apoptosis * mitochondria Subject RIV: EE - Microbiology, Virology Impact factor: 4.185, year: 2014 http://www.retrovirology.com/content/11/1/37

Vascular smooth muscle cell apoptosis is an early trigger for hypothyroid atherosclerosis.

Science.gov (United States)

Wang, Pei; Xu, Tian-Ying; Guan, Yun-Feng; Zhao, Yan; Li, Zhi-Yong; Lan, Xiao-Hong; Wang, Xia; Yang, Peng-Yuan; Kang, Zhi-Min; Vanhoutte, Paul M; Miao, Chao-Yu

2014-06-01

Endothelial dysfunction is an initial and vascular smooth muscle cell (VSMC) apoptosis, a later step of atherosclerosis. Hypothyroidism accelerates atherosclerosis. However, the early events responsible for this pro-atherosclerotic effect are unclear. Rats were resistant to induction of atherosclerosis by high cholesterol diet alone, but became susceptible in hypothyroid state achieved by administration of propylthiouracil (PTU) for 6 weeks. VSMC dysfunction and apoptosis were obvious within 1 week after PTU treatment, without signs of endothelial dysfunction. This early VSMC damage was caused by hypothyroidism but not the high cholesterol diet. In ApoE knockout mice, PTU-induced hypothyroidism triggered early VSMC apoptosis, increased oxidative stress, and accelerated atherosclerosis development. Thyroid hormone supplementation (T4, 10, or 50 μg/kg) prevented atherogenic phenotypes in hypothyroid rats and mice. In rats, thyroidectomy caused severe hypothyroidism 5 days after operation, which also led to rapid VSMC dysfunction and apoptosis. In vitro studies did not show a direct toxic effect of PTU on VSMCs. In contrast, thyroid hormone (T3, 0.75 μg/L plus T4, 50 nmol/L) exerted a direct protection against VSMC apoptosis, which was reduced by knockdown of TRα1, rather than TRβ1 and TRβ2 receptors. TRα1-mediated inhibition of apoptotic signalling of JNKs and caspase-3 contributed to the anti-apoptotic action of thyroid hormone. These findings provide an in vivo example for VSMC apoptosis as an early trigger of hypothyroidism-associated atherosclerosis, and reveal activation of TRα1 receptors to prevent VSMC apoptosis as a therapeutic strategy in this disease. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

Different routes lead to apoptosis in unfertilized sea urchin eggs.

Science.gov (United States)

Philippe, Laetitia; Tosca, Lucie; Zhang, Wen Ling; Piquemal, Marion; Ciapa, Brigitte

2014-03-01

Results obtained in various species, from mammals to invertebrates, show that arrest in the cell cycle of mature oocytes is due to a high ERK activity. Apoptosis is stimulated in these oocytes if fertilization does not occur. Our previous data suggest that apoptosis of unfertilized sea urchin eggs is the consequence of an aberrant short attempt of development that occurs if ERK is inactivated. They contradict those obtained in starfish, another echinoderm, where inactivation of ERK delays apoptosis of aging mature oocytes that are nevertheless arrested at G1 of the cell cycle as in the sea urchin. This suggests that the cell death pathway that can be activated in unfertilized eggs is not the same in sea urchin and in starfish. In the present study, we find that protein synthesis is necessary for the survival of unfertilized sea urchin eggs, contrary to starfish. We also compare the effects induced by Emetine, an inhibitor of protein synthesis, with those triggered by Staurosporine, a non specific inhibitor of protein kinase that is widely used to induce apoptosis in many types of cells. Our results indicate that the unfertilized sea urchin egg contain different mechanisms capable of leading to apoptosis and that rely or not on changes in ERK activity, acidity of intracellular organelles or intracellular Ca and pH. We discuss the validity of some methods to investigate cell death such as measurements of caspase activation with the fluorescent caspase indicator FITC-VAD-fmk or acidification of intracellular organelles, methods that may lead to erroneous conclusions at least in the sea urchin model.

Changes in mitochondrial dynamics during ceramide-induced cardiomyocyte early apoptosis.

Science.gov (United States)

Parra, Valentina; Eisner, Veronica; Chiong, Mario; Criollo, Alfredo; Moraga, Francisco; Garcia, Alejandra; Härtel, Steffen; Jaimovich, Enrique; Zorzano, Antonio; Hidalgo, Cecilia; Lavandero, Sergio

2008-01-15

In cells, mitochondria are organized as a network of interconnected organelles that fluctuate between fission and fusion events (mitochondrial dynamics). This process is associated with cell death. We investigated whether activation of apoptosis with ceramides affects mitochondrial dynamics and promotes mitochondrial fission in cardiomyocytes. Neonatal rat cardiomyocytes were incubated with C(2)-ceramide or the inactive analog dihydro-C(2)-ceramide for up to 6 h. Three-dimensional images of cells loaded with mitotracker green were obtained by confocal microscopy. Dynamin-related protein-1 (Drp-1) and mitochondrial fission protein 1 (Fis1) distribution and levels were studied by immunofluorescence and western blot. Mitochondrial membrane potential (DeltaPsi(m)) and cytochrome c (cyt c) distribution were used as indexes of early activation of apoptosis. Cell viability and DNA fragmentation were determined by propidium iodide staining/flow cytometry, whereas cytotoxicity was evaluated by lactic dehydrogenase activity. To decrease the levels of the mitochondrial fusion protein mitofusin 2, we used an antisense adenovirus (AsMfn2). C(2)-ceramide, but not dihydro-C(2)-ceramide, promoted rapid fragmentation of the mitochondrial network in a concentration- and time-dependent manner. C(2)-ceramide also increased mitochondrial Drp-1 and Fis1 content, Drp-1 colocalization with Fis1, and caused early activation of apoptosis. AsMfn2 accentuated the decrease in DeltaPsi(m) and cyt c redistribution induced by C(2)-ceramide. Doxorubicin, which induces cardiomyopathy and apoptosis through ceramide generation, also stimulated mitochondrial fragmentation. Ceramides stimulate mitochondrial fission and this event is associated with early activation of cardiomyocyte apoptosis.

Apoptosis in fresh and cryopreserved cardiac valves of pig samples.

Science.gov (United States)

Rendal Vázquez, M Esther; Díaz Román, T M; Rodríguez Cabarcos, M; Zavanella Botta, C; Domenech García, N; González Cuesta, M; Sánchez Dopico, M J; Pértega Díaz, S; Andión Núñez, C

2008-06-01

To analyse the influence of cold ischemic time (CIT) (2-24 h) and of cryopreservation (liquid phase) on the viability of the valvular fibroblasts and in the presence of apoptosis. Cardiac valves from 10 pigs were evaluated by anatomo-pathological study of the wall, muscle and leaflet. At the same time, the presence of cellular death due to apoptosis was investigated in two ways; directly on tissue by Apodetec system and by two-colour flow cytometry assay analyzing a suspension of fibroblast from valve leaflets using Anexina V and propidium iodure (PI). We established three groups of samples to compare different experimental conditions: 2 h of ischemia (group 1), 24 h of ischemia (group 2), and a programme of cryopreservation (-1 degrees C/min) after 2 h of ischemia, followed by storage in liquid nitrogen during a week and thawing was performed (group 3). The analysis of viabilities showed slight differences between all three groups. The results indicated CIT of 24 h undergoing more structural affectation than CIT of 2 h. Flow cytometry analysis did not show important differences between groups; however cryopreserved samples (group 3) slightly less viability and a higher percentage of death by apoptosis than group 1 and 2 using flow cytometry. Apoptosis was confirmed on tissue from all valves but mainly in samples of group 2 and group 3. In summary, the viability of the valves in the case of ischemic times of 2 h, 24 h or after cryopreservation/thawing differs slightly. The death of the cells is mainly mediated by necrosis and not by apoptosis.

The use of chemomodification for tumor apoptosis ceramide pathway induction

International Nuclear Information System (INIS)

Myitryajeva, N.A.; Bakaj, T.S.; Segeda, T.V.; Staren'kij, V.P.

2012-01-01

Comparative analysis of the clinical findings of pre-operative radiation therapy in patients with non-small-cell lung cancer with chemomodification (Taxotere, Etoposide, Cisplatin) and without it demonstrated the advantages of the combination therapy. Experimental investigation of chemomodifying effect of chemotherapy drugs (Taxotere, Etoposide, Cisplatin) on Guerin's carcinoma showed various mechanisms of accumulation of pro-apoptosis ceramides and their potential role in apoptosis induction and tumor regression.

Biological dosimetry: the potential use of radiation-induced apoptosis in human T-lymphocytes

International Nuclear Information System (INIS)

Menz, R.; Andres, R.; Larsson, B.; Ozsahin, M.; Crompton, N.E.A.; Trott, K.

1997-01-01

An assay for biological dosimetry based on the induction of apoptosis in human T-lymphocytes is described. Radiation-induced apoptosis was assessed by flow cytometric identification of cells displaying apoptosis-associated DNA condensation. CD4 and CD8 T-lymphocytes were analysed. They were recognized on the basis of their cell-surface antigens. Four parameters were measured for both cell types: cell size, granularity, antigen immunofluorescence and DNA content. Apoptosis was quantified as the fraction of CD4-, or CD8-positive cells with a characteristic reduction of cell size and DNA content. At doses below 1 Gy, levels of radiation-induced apoptosis increased for up to 5 days after irradiation. Optimal dose discrimination was observed 4 days after irradiation, at which time the dose-response curves were linear, with a slope of 8% ± 0.5% per 0.1 Gy. In controlled, dose-response experiments the lowest dose level at which the radiation-induced apoptosis frequency was still significantly above control was 0.05 Gy. After 5 days post-irradiation incubation, intra- and interdonor variations were measured and found to be similar; thus, apoptotic levels depend more on the dose than on the donor. The results demonstrate the potential of this assay as a biological dosimeter. (orig.)

Radiation-induced apoptosis in sensitive and resistant cells isolated from a mouse lymphoma

International Nuclear Information System (INIS)

Story, M.D.; Voehringer, D.W.; Malone, C.G.; Hobbs, M.L.; Meyn, R.E.

1994-01-01

Cells were isolated from a mouse lymphoma (LY-TH) and grown in vitro. They were susceptible to radiation-induced apoptosis after low doses with the appearance of endonucleolytically fragmented DNA 1 h after irradiation. Four hours after receiving 5 Gy, 80% of the DNA was endonucleolytically cleaved. Apoptosis induction by DNA double-strand break (dsb) formation was more effective compared with induction by single-strand break (ssb) formation. After long-term culturing, LY-TH cultures became refractory to apoptosis. Apoptosis-permissive cells (LY-as, cloned from LY-TH cells) were three times more radiosensitive than clonally expanded apoptosis-refractory cells (LY-ar). Low dose-rate irradiation and maintenance at 25 o C for 5 h postirradiation was sparing in LY-ar but not LY-as cells, suggesting a repair deficiency in LY-as cells. Analysis of dsb rejoining kinetics revealed no difference in the initial phase of dsb rejoining. After 1 h, however, relative dsbs in the LY-as variant increased as endonucleolytic cleavage was initiated. Signalling for radiation-induced apoptosis in LY-as cells was independent of the DNA dsb repair pathway and appeared determined by initial events, whereas in LY-ar cells, because of an inhibition in the apoptotic pathway, survival was enhanced and modifiable by repair processes. (author)

Role of CSL-dependent and independent Notch signaling pathways in cell apoptosis.

Science.gov (United States)

Zeng, Chong; Xing, Rui; Liu, Jing; Xing, Feiyue

2016-01-01

Apoptosis is a normally biological phenomenon in various organisms, involving complexly molecular mechanisms with a series of signaling processes. Notch signaling is found evolutionarily conserved in many species, playing a critical role in embryonic development, normal tissue homeostasis, angiogenesis and immunoregulation. The focus of this review is on currently novel advances about roles of CSL-dependent and independent Notch signaling pathways in cell apoptosis. The CSL can bind Notch intracellular domain (NIC) to act as a switch in mediating transcriptional activation or inactivation of the Notch signaling pathway downstream genes in the nucleus. It shows that CSL-dependent signaling regulates the cell apoptosis through Hes-1-PTEN-AKT-mTOR signaling, but rather the CSL-independent signaling mediates the cell apoptosis possibly via NIC-mTORC2-AKT-mTOR signaling, providing a new insight into apoptotic mechanisms.

TIMP-1 gene deficiency increases tumour cell sensitivity to chemotherapy-induced apoptosis

DEFF Research Database (Denmark)

Davidsen, Marie Louise; Würts, S.Ø.; Rømer, Maria Unni Koefoed

2006-01-01

deficiency increases the response to chemotherapy considerably, confirming that TIMP-1 protects the cells from apoptosis. This is to our knowledge the first study investigating TIMP-1 and chemotherapy-induced apoptosis employing a powerful model system comprising TIMP-1 gene-deficient cells...... this hypothesis, we have established TIMP-1 gene-deficient and TIMP-1 wild-type fibrosarcoma cells from mouse lung tissue. We have characterised these cells with regard to TIMP-1 genotype, TIMP-1 expression, malignant transformation and sensitivity to chemotherapy-induced apoptosis. We show that TIMP-1 gene...... and their genetically identical wild-type controls. For future studies, this cell system can be used to uncover the mechanisms and signalling pathways involved in the TIMP-1-mediated inhibition of apoptosis as well as to investigate the possibility of using TIMP-1 inhibitors to optimise the effect of conventional...

Apoptosis-like death, an extreme SOS response in Escherichia coli.

Science.gov (United States)

Erental, Ariel; Kalderon, Ziva; Saada, Ann; Smith, Yoav; Engelberg-Kulka, Hanna

2014-07-15

In bacteria, SOS is a global response to DNA damage, mediated by the recA-lexA genes, resulting in cell cycle arrest, DNA repair, and mutagenesis. Previously, we reported that Escherichia coli responds to DNA damage via another recA-lexA-mediated pathway resulting in programmed cell death (PCD). We called it apoptosis-like death (ALD) because it is characterized by membrane depolarization and DNA fragmentation, which are hallmarks of eukaryotic mitochondrial apoptosis. Here, we show that ALD is an extreme SOS response that occurs only under conditions of severe DNA damage. Furthermore, we found that ALD is characterized by additional hallmarks of eukaryotic mitochondrial apoptosis, including (i) rRNA degradation by the endoribonuclease YbeY, (ii) upregulation of a unique set of genes that we called extensive-damage-induced (Edin) genes, (iii) a decrease in the activities of complexes I and II of the electron transport chain, and (iv) the formation of high levels of OH˙ through the Fenton reaction, eventually resulting in cell death. Our genetic and molecular studies on ALD provide additional insight for the evolution of mitochondria and the apoptotic pathway in eukaryotes. Importance: The SOS response is the first described and the most studied bacterial response to DNA damage. It is mediated by a set of two genes, recA-lexA, and it results in DNA repair and thereby in the survival of the bacterial culture. We have shown that Escherichia coli responds to DNA damage by an additional recA-lexA-mediated pathway resulting in an apoptosis-like death (ALD). Apoptosis is a mode of cell death that has previously been reported only in eukaryotes. We found that E. coli ALD is characterized by several hallmarks of eukaryotic mitochondrial apoptosis. Altogether, our results revealed that recA-lexA is a DNA damage response coordinator that permits two opposite responses: life, mediated by the SOS, and death, mediated by the ALD. The choice seems to be a function of the degree

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

Pathway of 3-MCPD-induced apoptosis in human embryonic kidney cells.

Science.gov (United States)

Ji, Jian; Zhu, Pei; Sun, Chao; Sun, Jiadi; An, Lu; Zhang, Yinzhi; Sun, Xiulan

2017-01-01

3-Chloropropane-1,2-diol (3-MCPD) is a heat-produced contaminant formed during the preparation of soy sauce worldwide. The present investigation was conducted to determine the molecular aspects of 3-MCPD toxicity on human embryonic kidney cells (HEK293). Cell viability and apoptosis were assessed in response to exposure to 3-MCPD using the MTT assay and high-content screening (HCS). DNA damage, intracellular reactive oxygen species (ROS) and apoptosis-related proteins were evaluated. Genes related with apoptosis were detected by qPCR-array for further understanding the 3-MCPD induced cell apoptosis signaling pathway. Our results clearly showed that 3-MCPD treatment inhibits cell proliferation and reactive oxygen species generation. qPCR-array indicated that nine apoptotic genes were up-regulated more than 2-fold and six down-regulated more than 2-fold. Genes associated with the mitochondrial apoptotic pathway, especially BCL2 family genes, changed significantly, indicating that the mitochondrial apoptotic pathway is activated. Death receptor pathway-related genes, TNFRSF11B and TNFRSF1A, changed significantly, indicating that the death receptor pathway is also activated, resulting in the inhibition of cell growth and proliferation as well as induction of apoptosis. To sum up, the experiment results indicated that 3-MCPD induced HEK293 cell toxicity through the death receptor pathway and mitochondrial pathway.

Proteomics analysis of apoptosis-regulating proteins in tissues with different radiosensitivity

International Nuclear Information System (INIS)

An, Jeung-Hee; Seong, Jin-Sil

2006-01-01

The aim of this study was to identify of radiosusceptibility proteins in tissues with different radiosensitivity. C3H/HeJ mice were exposed to 10 Gy. The tissues were processed for proteins extraction and were analyzed by 2-dimensional electrophoresis. The proteins were identified by matrix-assisted laser desorption ionizing time-of-flight mass spectrometry and validated by immunohistochemical staining and Western blotting. The peaks of apoptosis levels were 35.3±1.7% and 0.6±0.2% in the spleen and the liver, respectively, after ionizing radiation. Analysis of liver tissue showed that the expression level of reactive oxygen species (ROS) related proteins such as cytochrome c, glutathione S transferase, NADH dehydrogenase and peroxiredoxin VI increased after radiation. The expression level of cytochrome c increased to 3-fold after ionizing radiation in both tissues. However in spleen tissue, the expression level of various kinds of apoptosis regulating proteins increased after radiation. These involved iodothyronine, CD 59A glycoprotein precursor, fas antigen and tumor necrosis factor -inducible protein TSG-6nprecursor after radiation. The difference in the apoptosis index between the liver and spleen tissues is closely associated with the expression of various kinds of apoptosis-related proteins. The result suggests that the expression of apoptosis-related protein and redox proteins play important roles in this radiosusceptibility. (author)

Apoptosis in the chicken bursa of fabricius induced by X-irradiation.

Science.gov (United States)

Arai, S; Kowada, T; Takehana, K; Miyoshi, K; Nakanishi, Y H; Hayashi, M

1996-10-01

Immature B lymphocytes in the chicken bursa of Fabricius have previously been reported to undergo apoptosis by low doses of ionizing radiation. In the present study, newly hatched chickens were subjected to whole-body X-irradiation, and the bursa of Fabricius was examined at various postirradiation times by light and electron microscopy to obtain information on the change of ultrastructure of irradiated bursal cells as well as on the time course and dose-response for the induction of apoptosis. Histological examination by light microscopy showed that pyknotic cells started to increase in the bursa within a few hours after irradiation and the frequency of occurrence reached a maximum at 6 hr. An evident increase of the pyknotic cells in number was observed at a dose of as little as 1 Gy, and the frequency increased with increases in the dose, reaching over 90% at 15 Gy. Electron microscopy of the irradiated bursa revealed typical apoptotic morphology such as chromatin condensation, nuclear fragmentation, formation of apoptotic bodies and phagocytosis of pyknotic cells. Induction of apoptosis was also confirmed by the appearance of a typical DNA ladder pattern on agarose gel. Thus, the present results demonstrate that the chicken bursal cells are hypersensitive to X-irradiation with regard to induction of apoptosis, and that the apoptotic bursal cells exhibit most of the ultrastructural features known to be typical of apoptosis.

NFAT2 mediates high glucose-induced glomerular podocyte apoptosis through increased Bax expression

International Nuclear Information System (INIS)

Li, Ruizhao; Zhang, Li; Shi, Wei; Zhang, Bin; Liang, Xinling; Liu, Shuangxin; Wang, Wenjian

2013-01-01

Background: Hyperglycemia promotes podocyte apoptosis and plays a key role in the pathogenesis of diabetic nephropathy. However, the mechanisms that mediate hyperglycemia-induced podocyte apoptosis is still far from being fully understood. Recent studies reported that high glucose activate nuclear factor of activated T cells (NFAT) in vascular smooth muscle or pancreatic β-cells. Here, we sought to determine if hyperglycemia activates NFAT2 in cultured podocyte and whether this leads to podocyte apoptosis. Meanwhile, we also further explore the mechanisms of NFAT2 activation and NFAT2 mediates high glucose-induced podocyte apoptosis. Methods: Immortalized mouse podocytes were cultured in media containing normal glucose (NG), or high glucose (HG) or HG plus cyclosporine A (a pharmacological inhibitor of calcinerin) or 11R-VIVIT (a special inhibitor of NFAT2). The activation of NFAT2 in podocytes was detected by western blotting and immunofluorescence assay. The role of NFAT2 in hyperglycemia-induced podocyte apoptosis was further evaluated by observing the inhibition of NFAT2 activation by 11R-VIVIT using flow cytometer. Intracellular Ca 2+ was monitored in HG-treated podcocytes using Fluo-3/AM. The mRNA and protein expression of apoptosis gene Bax were measured by real time-qPCR and western blotting. Results: HG stimulation activated NFAT2 in a time- and dose-dependent manner in cultured podocytes. Pretreatment with cyclosporine A (500 nM) or 11R-VIVIT (100 nM) completely blocked NFAT2 nuclear accumulation. Meanwhile, the apoptosis effects induced by HG were also abrogated by concomitant treatment with 11R-VIVIT in cultured podocytes. We further found that HG also increased [Ca 2+ ]i, leading to activation of calcineurin, and subsequent increased nuclear accumulation of NFAT2 and Bax expression in cultured podocytes. Conclusion: Our results identify a new finding that HG-induced podocyte apoptosis is mediated by calcineurin/NFAT2/Bax signaling pathway, which may

NFAT2 mediates high glucose-induced glomerular podocyte apoptosis through increased Bax expression

Energy Technology Data Exchange (ETDEWEB)

Li, Ruizhao, E-mail: liruizhao1979@126.com [Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080 (China); Zhang, Li, E-mail: Zhanglichangde@163.com [Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080 (China); Southern Medical University, Guangzhou, Guangdong (China); Shi, Wei, E-mail: shiwei.gd@139.com [Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080 (China); Zhang, Bin, E-mail: zhangbinyes@yahoo.com.cn [Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080 (China); Liang, Xinling, E-mail: xinlingliang@yahoo.com [Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080 (China); Liu, Shuangxin, E-mail: mplsxi@yahoo.com.cn [Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080 (China); Wang, Wenjian, E-mail: wwjph@yahoo.com [Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080 (China)

2013-04-15

Background: Hyperglycemia promotes podocyte apoptosis and plays a key role in the pathogenesis of diabetic nephropathy. However, the mechanisms that mediate hyperglycemia-induced podocyte apoptosis is still far from being fully understood. Recent studies reported that high glucose activate nuclear factor of activated T cells (NFAT) in vascular smooth muscle or pancreatic β-cells. Here, we sought to determine if hyperglycemia activates NFAT2 in cultured podocyte and whether this leads to podocyte apoptosis. Meanwhile, we also further explore the mechanisms of NFAT2 activation and NFAT2 mediates high glucose-induced podocyte apoptosis. Methods: Immortalized mouse podocytes were cultured in media containing normal glucose (NG), or high glucose (HG) or HG plus cyclosporine A (a pharmacological inhibitor of calcinerin) or 11R-VIVIT (a special inhibitor of NFAT2). The activation of NFAT2 in podocytes was detected by western blotting and immunofluorescence assay. The role of NFAT2 in hyperglycemia-induced podocyte apoptosis was further evaluated by observing the inhibition of NFAT2 activation by 11R-VIVIT using flow cytometer. Intracellular Ca{sup 2+} was monitored in HG-treated podcocytes using Fluo-3/AM. The mRNA and protein expression of apoptosis gene Bax were measured by real time-qPCR and western blotting. Results: HG stimulation activated NFAT2 in a time- and dose-dependent manner in cultured podocytes. Pretreatment with cyclosporine A (500 nM) or 11R-VIVIT (100 nM) completely blocked NFAT2 nuclear accumulation. Meanwhile, the apoptosis effects induced by HG were also abrogated by concomitant treatment with 11R-VIVIT in cultured podocytes. We further found that HG also increased [Ca{sup 2+}]i, leading to activation of calcineurin, and subsequent increased nuclear accumulation of NFAT2 and Bax expression in cultured podocytes. Conclusion: Our results identify a new finding that HG-induced podocyte apoptosis is mediated by calcineurin/NFAT2/Bax signaling pathway

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.

Apoptosis in differentiating C2C12 muscle cells selectively targets Bcl-2-deficient myotubes

Science.gov (United States)

Schoneich, Christian; Dremina, Elena; Galeva, Nadezhda; Sharov, Victor

2014-01-01

Muscle cell apoptosis accompanies normal muscle development and regeneration, as well as degenerative diseases and aging. C2C12 murine myoblast cells represent a common model to study muscle differentiation. Though it was already shown that myogenic differentiation of C2C12 cells is accompanied by enhanced apoptosis in a fraction of cells, either the cell population sensitive to apoptosis or regulatory mechanisms for the apoptotic response are unclear so far. In the current study we characterize apoptotic phenotypes of different types of C2C12 cells at all stages of differentiation, and report here that myotubes of differentiated C2C12 cells with low levels of anti-apoptotic Bcl-2 expression are particularly vulnerable to apoptosis even though they are displaying low levels of pro-apoptotic proteins Bax, Bak and Bad. In contrast, reserve cells exhibit higher levels of Bcl-2 and high resistance to apoptosis. The transfection of proliferating myoblasts with Bcl-2 prior to differentiation did not protect against spontaneous apoptosis accompanying differentiation of C2C12 cell but led to Bcl-2 overexpression in myotubes and to significant protection from apoptotic cell loss caused by exposure to hydrogen peroxide. Overall, our data advocate for a Bcl-2-dependent mechanism of apoptosis in differentiated muscle cells. However, downstream processes for spontaneous and hydrogen peroxide induced apoptosis are not completely similar. Apoptosis in differentiating myoblasts and myotubes is regulated not through interaction of Bcl-2 with pro-apoptotic Bcl-2 family proteins such as Bax, Bak, and Bad. PMID:24129924

Mycobacterium avium MAV2052 protein induces apoptosis in murine macrophage cells through Toll-like receptor 4.

Science.gov (United States)

Lee, Kang-In; Choi, Han-Gyu; Son, Yeo-Jin; Whang, Jake; Kim, Kwangwook; Jeon, Heat Sal; Park, Hye-Soo; Back, Yong Woo; Choi, Seunga; Kim, Seong-Woo; Choi, Chul Hee; Kim, Hwa-Jung

2016-04-01

Mycobacterium avium and its sonic extracts induce apoptosis in macrophages. However, little is known about the M. avium components regulating macrophage apoptosis. In this study, using multidimensional fractionation, we identified MAV2052 protein, which induced macrophage apoptosis in M. avium culture filtrates. The recombinant MAV2052 induced macrophage apoptosis in a caspase-dependent manner. The loss of mitochondrial transmembrane potential (ΔΨm), mitochondrial translocation of Bax, and release of cytochrome c from mitochondria were observed in macrophages treated with MAV2052. Further, reactive oxygen species (ROS) production was required for the apoptosis induced by MAV2052. In addition, ROS and mitogen-activated protein kinases were involved in MAV2052-mediated TNF-α and IL-6 production. ROS-mediated activation of apoptosis signal-regulating kinase 1 (ASK1)-JNK pathway was a major signaling pathway for MAV2052-induced apoptosis. Moreover, MAV2052 bound to Toll-like receptor (TLR) 4 molecule and MAV2052-induced ROS production, ΔΨm loss, and apoptosis were all significantly reduced in TLR4(-/-) macrophages. Altogether, our results suggest that MAV2052 induces apoptotic cell death through TLR4 dependent ROS production and JNK pathway in murine macrophages.

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

Rituximab enhances radiation-triggered apoptosis in non-Hodgkin's lymphoma cells via caspase-dependent and - independent mechanisms

International Nuclear Information System (INIS)

Skvortsova, I.; Skvortsov, S.; Popper, B.A.; Haidenberger, A.; Saurer, M.; Gunkel, A.R.; Zwierzina, H.; Lukas, P.

2006-01-01

Rituximab (RTX), a chimeric human anti-CD20 monoclonal antibody, is currently employed in the treatment of malignant non-Hodgkin's lymphoma (NHL) either alone or in combination with other cytotoxic approaches. The present study examines the effects of ionizing radiation in combination with RTX on proliferation and apoptosis development in B-lymphoma RL and Raji cells. RTX was used at a concentration of 10 μg/mL 24 hours prior to irradiation at a single dose of 9 Gy. CD20 expression, cell viability, apoptosis, mitochondrial membrane potential and apoptosis-related proteins were evaluated in the treated B cells. The constitutive level of CD20 expression in RL and Raji lymphoma cells did not play an essential role in RTX-induced cell growth delay. Both lymphoma cells showed similar inhibition of cell proliferation without apoptosis development in response to RTX treatment. Exposure to ionizing radiation induced cell growth delay and apoptosis in RL cells, whereas Raji cells showed moderate radio-resistance and activation of cell growth at 24 hours after irradiation, which was accompanied by increased radiation-triggered CD20 expression. The simultaneous exposure of lymphoma cells to ionizing radiation and RTX abrogated radioresistance of Raji cells and significantly enhanced cell growth delay and apoptosis in RL cells. X-linked inhibitor of apoptosis protein (XIAP) and the inducible form of heat shock protein 70 (Hsp70) were positively modulated by RTX in combination with ionizing radiation in order to induce apoptosis. Furthermore, it was demonstrated that mitochondrial membrane potential dissipation is not an essential component to induce apoptosis-inducing factor (AIF) maturation and apoptosis. Our results show that RTX-triggered enhancement of radiation-induced apoptosis and cell growth delay is achieved by modulation of proteins involved in programmed cell death. (author)

Apoptosis induced by radionuclide 153Sm and expression of relevant genes in three different cancer cells

International Nuclear Information System (INIS)

Zou Baomin; Duan Xiaoyi; Chen Wei; Hu Guoying

2003-01-01

To study apoptosis of PC-3, ER-75-30 and A549 cells induced by radionuclide 153 Sm and the expression of bcl-2, bax in apoptosis cells, MTT assay was used to detect the anti-tumor effect, light microscope, transmission electron microscope, flow cytometer were used to detect apoptosis, while image analysis was used to detect the expression of bcl-2 and bax. 153 Sm showed anti-tumor effect and could induce tumor cell apoptosis. Both bcl-2 and bax played an important role in apoptosis. Different kind of cells had different sensitivity to 153 Sm

Functional analysis of molecular mechanisms of radiation induced apoptosis, that are not mediated by DNA damages

International Nuclear Information System (INIS)

Angermeier, Marita; Moertl, Simone

2012-01-01

The effects of low-dose irradiation pose new challenges on the radiation protection efforts. Enhanced cellular radiation sensitivity is displayed by disturbed cellular reactions and resulting damage like cell cycle arrest, DNA repair and apoptosis. Apoptosis serves as genetically determinate parameter for the individual radiation sensitivity. In the frame of the project the radiation-induced apoptosis was mechanistically investigated. Since ionizing radiation induced direct DNA damage and generates a reactive oxygen species, the main focus of the research was the differentiation and weighting of DNA damage mediated apoptosis and apoptosis caused by the reactive oxygen species (ROS).

The studies on thyrocyte apoptosis and expression of Bcl-2 and Bax in Hashimoto's thyroiditis

International Nuclear Information System (INIS)

Zhao Yaping; Wang Jialing; Fan Zhiyong; Liu Zehong; Wu HeJun; Zhou Wei; Jia Meizhai

2003-01-01

To investigate the thyrocyte apoptosis, the expression of Bcl-2, Bax and the relationship between apoptosis and the pathogenesis in Hashimoto's thyroiditis (HT), 41 HT thyroid and 10 normal thyroid specimens were selected. The level of apoptosis was detected by TUNEL methods. The expression and distribution of Bcl-2 and Bax were detected using immunohistochemical methods and analyzed by Mias99 pathological image system. Immunohistochemical staining was carried out using S-P kit. The Result showed that an increased level of apoptosis was observed in Hashimoto's glands. The apoptosis mainly distributed in thyroid follicles destruction area. This was associated with increased Bax expression. The strongly positive Bcl-2 staining was observed in the thyrocyte of intact thyroid follicles. The ratios of positive granule area and total light density of Bcl-2 to those of Bax in HT thyroid follicle area were lower than those in normal thyroid. The apoptosis of thyrocyte induced by dysregulation of Bcl-2 and Bax may be involved in the pathogeneses of HT

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.

Effects of ghrelin on the apoptosis of human neutrophils in vitro

Science.gov (United States)

Li, Bin; Zeng, Mian; Zheng, Haichong; Huang, Chunrong; He, Wanmei; Lu, Guifang; Li, Xia; Chen, Yanzhu; Xie, Ruijie

2016-01-01

Acute respiratory distress syndrome (ARDS) is characterized by lung inflammation and the diffuse infiltration of neutrophils into the alveolar space. Neutrophils are abundant, short-lived leukocytes that play a key role in immune defense against microbial infections. These cells die via apoptosis following the activation and uptake of microbes, and will also enter apoptosis spontaneously at the end of their lifespan if they do not encounter pathogens. Apoptosis is essential for the removal of neutrophils from inflamed tissues and for the timely resolution of neutrophilic inflammation. Ghrelin is an endogenous ligand for the growth hormone (GH) secretagogue receptor, produced and secreted mainly from the stomach. Previous studies have reported that ghrelin exerts anti-inflammatory effects in lung injury through the regulation of the apoptosis of different cell types; however, the ability of ghrelin to regulate alveolar neutrophil apoptosis remains largely undefined. We hypothesized that ghrelin may have the ability to modulate neutrophil apoptosis. In this study, to examine this hypothesis, we investigated the effects of ghrelin on freshly isolated neutrophils in vitro. Our findings demonstrated a decrease in the apoptotic ratio (as shown by flow cytometry), as well as in the percentage of cells with decreased mitochondrial membrane potential (ΔΨm) and in the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick-end labeling-positive rate, accompanied by an increased B-cell lymphoma 2/Bax ratio and the downregulation of cleaved caspase-3 in neutrophils following exposure to lipopolysaccharide (100 ng/ml). However, pre-treatment with ghrelin at a physiological level (100 nM) did not have a notable influence on the neutrophils in all the aforementioned tests. Our findings suggest that ghrelin may not possess the ability to modulate the neutrophil lifespan in vitro. PMID:27431014

Radiation-induced apoptosis in differentially modulated by PTK inhibitora in K562 cells

International Nuclear Information System (INIS)

Lee, Hyung Sik; Moon, Chang Woo; Hur, Won Joo; Jeong, Su Jin; Jeong Min Ho; Lee, Jeong Hyeon; Lim, Young Jin; Park, Heon Joo

2000-01-01

The effect of PTK inhibitors (herbimycin A and genistein) on the induction of radiation-induced apoptosis in Ph-positive K562 leukemia cell line was investigated. K562 cells in exponential growth phase were irradiated with a linear accelerator at room temperature. For 6 MV X-ray irradiation and drug treatment, cultures were initiated at 2x10 6 cells/ml. The cells were irradiated with 10Gy. Stock solutions of herbimycin A and genistein were prepared in dimethyl sulphoxide (DMSO). After incubation at 37 .deg. for 0-48 h, the extent of apoptosis was determined using agarose gel electrophoresis and TUNEL assay. The progression of cells through the cell cycle after irradiation and drug treatment was also determined with flow cytometry. Western blot analysis was used to monitor bcl-2, bcl-X-L and bax protein levels. Treatment with 10 Gy X-irradiation did not result in the induction of apoptosis. The HMA alone (500 nM) also failed to induce apoptosis. By contrast, incubation of K562 cells with HMA after irradiation resulted in a substantial induction of nuclear condensation and fragmentation by agarose gel electrophoresis and TUNEL assay. Genistein failed to enhance the ability of X-irradiation to induce DNA fragmentation. Enhancement of apoptosis by HMA was not attributable to downregulation of the bcl-2 or bcl-X-L anti-apoptotic proteins. When the cells were irradiated and maintained with HMA, the percentage of cells in G2/M phase decreased to 30-40% at 48 h. On the other hand, cells exposed to 10 Gy X-irradiation alone or maintained with genistein did not show marked cell cycle redistribution. We have shown that nanomolar concentrations of the PTK inhibitor HMA synergize with X-irradiation in inducing the apoptosis in Ph (+) K562 leukemia cell line. While, genistein, a PTK inhibitor which is not selective for p210 bcr/abl failed to enhance the radiation induced apoptosis in K562 cells. It is unlikely that the ability of HMA to enhance apoptosis in K562 cells is

Survivin - an inhibitor of apoptosis and a new therapeutic target in cancer

International Nuclear Information System (INIS)

Pizem, J.; Coer, A.

2003-01-01

Survivin is a unique member of the inhibitor of apoptosis (IAP) protein family. It inhibits apoptosis by interfering with post-mitochondrial events during apoptosis, thus blocking activation of caspases. The expression of survivin is among the most tumour specific of all human genes. It is overexpressed in most human cancers but is not detected in most normal tissues. Some molecular mechanisms of survivin upregulation in cancer have been elucidated, including loss of the wild-type p53. Tumours that overexpress survivin generally bear a worse prognosis and are associated with resistance to therapy. Its differential expression in cancer versus normal tissues makes survivin detection a useful tool in cancer diagnostics and a promising therapeutic target. Survivin targeting has resulted in increased spontaneous and induced apoptosis and inhibition of tumour growth. Some anticancer drugs currently introduced into clinical practice might well act by inactivating survivin. (author)

Serial killers: ordering caspase activation events in apoptosis.

Science.gov (United States)

Slee, E A; Adrain, C; Martin, S J

1999-11-01

Caspases participate in the molecular control of apoptosis in several guises; as triggers of the death machinery, as regulatory elements within it, and ultimately as a subset of the effector elements of the machinery itself. The mammalian caspase family is steadily growing and currently contains 14 members. At present, it is unclear whether all of these proteases participate in apoptosis. Thus, current research in this area is focused upon establishing the repertoire and order of caspase activation events that occur during the signalling and demolition phases of cell death. Evidence is accumulating to suggest that proximal caspase activation events are typically initiated by molecules that promote caspase aggregation. As expected, distal caspase activation events are likely to be controlled by caspases activated earlier in the cascade. However, recent data has cast doubt upon the functional demarcation of caspases into signalling (upstream) and effector (downstream) roles based upon their prodomain lengths. In particular, caspase-3 may perform an important role in propagating the caspase cascade, in addition to its role as an effector caspase within the death programme. Here, we discuss the apoptosis-associated caspase cascade and the hierarchy of caspase activation events within it.

Study on apoptosis of prostate cancer cell induced by 125I seed irradiation

International Nuclear Information System (INIS)

Liao Anyan; Wang Junjie; Wang Jidong; Zhuang Hongqing; Zhao Yong

2007-01-01

Objective: To explore the mechanism of apoptosis induced by 125 I seed irradiation on PC3 cells. Methods: Human prostate cancer cell line PC3 was treated by irradiation of 125 I (2.77 cGy/h) with various dose. Agarose gel electrophoresis of DNA and flows cytometry were used to detect the apoptosis of PC3 cells and indirect immunofluorescence assay was used to detect the expression of Bcl-2. The activity of Caspase-3 was measured by Caspase Colorimetric Assay Kits. Results: Apoptosis of PC3 cells could be efficiently induced by 125 I seed irradiation. The apoptotic peaks were found by flow cytometry and DNA ladder appeared on 1.8% agarose gel. The activity of Caspase-3 on PC3 cells treated by 125 I seed irradiation was not changed significantly. Bcl-2 gene expression was down-regulated with the sample concentration increased. Conclusion: 125 I irradiation can induce the apoptosis of PC3 cells and the mechanism of apoptosis is related with down regulation of Bcl-2 gene expression and is not related with Caspase-3 activity. (authors)

BIM is the primary mediator of MYC-induced apoptosis in multiple solid tissues.

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Muthalagu, Nathiya; Junttila, Melissa R; Wiese, Katrin E; Wolf, Elmar; Morton, Jennifer; Bauer, Barbara; Evan, Gerard I; Eilers, Martin; Murphy, Daniel J

2014-09-11

MYC is one of the most frequently overexpressed oncogenes in human cancer, and even modestly deregulated MYC can initiate ectopic proliferation in many postmitotic cell types in vivo. Sensitization of cells to apoptosis limits MYC's oncogenic potential. However, the mechanism through which MYC induces apoptosis is controversial. Some studies implicate p19ARF-mediated stabilization of p53, followed by induction of proapoptotic BH3 proteins NOXA and PUMA, whereas others argue for direct regulation of BH3 proteins, especially BIM. Here, we use a single experimental system to systematically evaluate the roles of p19ARF and BIM during MYC-induced apoptosis, in vitro, in vivo, and in combination with a widely used chemotherapeutic, doxorubicin. We find a common specific requirement for BIM during MYC-induced apoptosis in multiple settings, which does not extend to the p53-responsive BH3 family member PUMA, and find no evidence of a role for p19ARF during MYC-induced apoptosis in the tissues examined. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Palmitate induces VSMC apoptosis via toll like receptor (TLR)4/ROS/p53 pathway.

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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.

Interferon-gamma sensitizes colonic epithelial cell lines to physiological and therapeutic inducers of colonocyte apoptosis.

LENUS (Irish Health Repository)

O'Connell, J

2012-02-03

Homeostasis in the colonic epithelium is achieved by a continuous cycle of proliferation and apoptosis, in which imbalances are associated with disease. Inflammatory bowel disease (IBD) and colon cancer are associated with either excessive or insufficient apoptosis of colonic epithelial cells, respectively. By using two colonic epithelial cell lines, HT29 and SW620, we investigated how the epithelial cell\\'s sensitivity to apoptosis was regulated by the proinflammatory cytokine interferon-gamma (IFN-gamma). We found that IFN-gamma sensitized HT29 cells, and to a lesser extent SW620, to diverse inducers of apoptosis of physiologic or therapeutic relevance to the colon. These apoptosis inducers included Fas (CD95\\/APO-1) ligand (FasL), short-chain fatty acids, and chemotherapeutic drugs. The extent of IFN-gamma-mediated apoptosis sensitization in these two cell lines correlated well with the degree of IFN-gamma-mediated upregulation of the proapoptotic protease caspase-1. Although IFN-gamma alone effectively sensitized HT29 cells to apoptosis, inclusion of the protein synthesis inhibitor cyclohexamide (CHX) during apoptotic challenge was necessary for maximal sensitization of SW620. The requirement of CHX to sensitize SW620 cells to apoptosis implies a need to inhibit translation of antiapoptotic proteins absent from HT29. In particular, the antiapoptotic protein Bcl-2 was strongly expressed in SW620 cells but absent from HT29. Our results indicate that IFN-gamma increases the sensitivity of colonic epithelial cells to diverse apoptotic stimuli in concert, via upregulation of caspase-1. Our findings implicate caspase-1 and Bcl-2 as important central points of control determining the general sensitivity of colonic epithelial cells to apoptosis.

Trichloroethylene metabolite S-(1,2-dichlorovinyl)-l-cysteine induces lipid peroxidation-associated apoptosis via the intrinsic and extrinsic apoptosis pathways in a first-trimester placental cell line.

Science.gov (United States)

Elkin, Elana R; Harris, Sean M; Loch-Caruso, Rita

2018-01-01

Trichloroethylene (TCE), a prevalent environmental contaminant, is a potent renal and hepatic toxicant through metabolites such as S-(1, 2-dichlorovinyl)-l-cysteine (DCVC). However, effects of TCE on other target organs such as the placenta have been minimally explored. Because elevated apoptosis and lipid peroxidation in placenta have been observed in pregnancy morbidities involving poor placentation, we evaluated the effects of DCVC exposure on apoptosis and lipid peroxidation in a human extravillous trophoblast cell line, HTR-8/SVneo. We exposed the cells in vitro to 10-100μM DCVC for various time points up to 24h. Following exposure, we measured apoptosis using flow cytometry, caspase activity using luminescence assays, gene expression using qRT-PCR, and lipid peroxidation using a malondialdehyde quantification assay. DCVC significantly increased apoptosis in time- and concentration-dependent manners (p<0.05). DCVC also significantly stimulated caspase 3, 7, 8 and 9 activities after 12h (p<0.05), suggesting that DCVC stimulates the activation of both the intrinsic and extrinsic apoptotic signaling pathways simultaneously. Pre-treatment with the tBID inhibitor Bl-6C9 partially reduced DCVC-stimulated caspase 3 and 7 activity, signifying crosstalk between the two pathways. Additionally, DCVC treatment increased lipid peroxidation in a concentration-dependent manner. Co-treatment with the antioxidant peroxyl radical scavenger (±)-α-tocopherol attenuated caspase 3 and 7 activity, suggesting that lipid peroxidation mediates DCVC-induced apoptosis in extravillous trophoblasts. Our findings suggest that DCVC-induced apoptosis and lipid peroxidation in extravillous trophoblasts could contribute to poor placentation if similar effects occur in vivo in response to TCE exposure, indicating that further studies into this mechanism are warranted. Copyright © 2017 Elsevier Inc. All rights reserved.

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.

Mechanism research of miR-181 regulating human lens epithelial cell apoptosis

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Yu Qin

2015-05-01

Full Text Available AIM: To investigate the expression of miR-181 in the lens tissue of cataract and the regulating mechanism of miR-181 on apoptosis of human lens epithelial cell.METHODS:Real time q-PCR was used to measure the expression of miR-181 in the anterior lens capsules of age-related cataract and human lens epithelial cell apoptosis model. miR-181 mimic and inhibitor were transfected using Lipofectamine 2 000 to regulate the expression of miR-181, and then Real time q-PCR was used to verify transfection efficiency. Flow cytometry was used to detect the change of cell apoptosis rate. RESULTS: Compared with control group, the expression of miR-181 was significantly higher in both the anterior lens capsules of age-related cataract and human lens epithelial cell apoptosis model; the relative expression of miR-181 in lens epithelial cells transfected with miR-181 mimic was increased, whereas decreased in cells transfected with miR-181 inhibitor; the apoptosis rate of cells transfected with miR-181 mimic was increased, while reduced in miR-181 inhibitor group. Each result was statistically significant(PCONCLUSION: High expression of miR-181 is detected in anterior lens capsule of age-related cataract. miR-181 might play a certain role in the pathogenesis of cataract via promoting human lens epithelial cell apoptosis. miR-181 probably becomes a new approach for the nonoperative treatment of cataract, but the concrete mechanism still needs to be further studied.

Modulation of Apoptosis Pathways by Oxidative Stress and Autophagy in β Cells

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Maorong Wang

2012-01-01

Full Text Available Human islets isolated for transplantation are exposed to multiple stresses including oxidative stress and hypoxia resulting in significant loss of functional β cell mass. In this study we examined the modulation of apoptosis pathway genes in islets exposed to hydrogen peroxide, peroxynitrite, hypoxia, and cytokines. We observed parallel induction of pro- and antiapoptotic pathways and identified several novel genes including BFAR, CARD8, BNIP3, and CIDE-A. As BNIP3 is an inducer of autophagy, we examined this pathway in MIN6 cells, a mouse beta cell line and in human islets. Culture of MIN6 cells under low serum conditions increased the levels of several proteins in autophagy pathway, including ATG4, Beclin 1, LAMP-2, and UVRAG. Amino acid deprivation led to induction of autophagy in human islets. Preconditioning of islets with inducers of autophagy protected them from hypoxia-induced apoptosis. However, induction of autophagy during hypoxia exacerbated apoptotic cell death. ER stress led to induction of autophagy and apoptosis in β cells. Overexpression of MnSOD, an enzyme that scavenges free radicals, resulted in protection of MIN6 cells from cytokine-induced apoptosis. Ceramide, a mediator of cytokine-induced injury, reduced the active phosphorylated form of Akt and downregulated the promoter activity of the antiapoptotic gene bcl-2. Furthermore, cytokine-stimulated JNK pathway downregulated the bcl-2 promoter activity which was reversed by preincubation with SP600125, a JNK inhibitor. Our findings suggest that β cell apoptosis by multiple stresses in islets isolated for transplantation is the result of orchestrated gene expression in apoptosis pathway.

Effect of smoking on neutrophil apoptosis in chronic periodontitis: An immunohistochemical study

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Sachin S Shivanaikar

2013-01-01

Full Text Available Context: Periodontal disease is caused by chronic infection inducing an inflammatory reaction leading to breakdown of tooth-supporting tissues. There are various risk factors for the disease, and smoking is one of them. Apoptosis plays a critical role in the regulation of inflammation and host immune response which helps in tissue homeostasis, and a disturbance in this is often associated with disease. The imbalance between the apoptosis and proliferation in the periodontal tissue results in periodontal disease. Neutrophils play an important role in the defense mechanism and are the most abundant immune cells in gingival inflammatory infiltrate in patients suffering from periodontal disease. Neutrophil disorders are associated with rapid destruction of periodontal tissues. Aim: To study the influence of smoking on apoptosis of neutrophils by quantifying them in the gingival connective tissue of smoking and nonsmoking subjects suffering from chronic periodontitis. Materials and Methods: Thirty gingival biopsies were harvested from 15 smoking and 15 nonsmoking subjects who suffered from chronic periodontitis. The apoptosis of neutrophils was assessed and quantified using p53 monoclonal mouse antihuman antibody. Statistical Analysis Used: Chi-square/Fisher′sexact test was used to find the significance of study parameters on a categorical scale between the two groups. Results: Neutrophil apoptosis was significantly more in the group of nonsmokers. There was no statistical difference between plaque and bleeding index, but there was a significant increase in clinical attachment loss among smokers. Conclusions: The study reveals that smoking plays a significant role in the inhibition of neutrophil apoptosis, thereby contributing to the destruction of periodontal tissues in periodontitis.

Neem oil limonoids induces p53-independent apoptosis and autophagy.

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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.

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

Drosophila MOF regulates DIAP1 and induces apoptosis in a JNK dependent pathway.

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Pushpavalli, Sreerangam N C V L; Sarkar, Arpita; Ramaiah, M Janaki; Koteswara Rao, G; Bag, Indira; Bhadra, Utpal; Pal-Bhadra, Manika

2016-03-01

Histone modulations have been implicated in various cellular and developmental processes where in Drosophila Mof is involved in acetylation of H4K16. Reduction in the size of larval imaginal discs is observed in the null mutants of mof with increased apoptosis. Deficiency involving Hid, Reaper and Grim [H99] alleviated mof (RNAi) induced apoptosis in the eye discs. mof (RNAi) induced apoptosis leads to activation of caspases which is suppressed by over expression of caspase inhibitors like P35 and Diap1 clearly depicting the role of caspases in programmed cell death. Also apoptosis induced by knockdown of mof is rescued by JNK mutants of bsk and tak1 indicating the role of JNK in mof (RNAi) induced apoptosis. The adult eye ablation phenotype produced by ectopic expression of Hid, Rpr and Grim, was restored by over expression of Mof. Accumulation of Mof at the Diap1 promoter 800 bp upstream of the transcription start site in wild type larvae is significantly higher (up to twofolds) compared to mof (1) mutants. This enrichment coincides with modification of histone H4K16Ac indicating an induction of direct transcriptional up regulation of Diap1 by Mof. Based on these results we propose that apoptosis triggered by mof (RNAi) proceeds through a caspase-dependent and JNK mediated pathway.

LR-90 prevents methylglyoxal-induced oxidative stress and apoptosis in human endothelial cells

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Figarola, James L.; Singhal, Jyotsana; Rahbar, Samuel; Awasthi, Sanjay

2014-01-01

Methylglyoxal (MGO) is a highly reactive dicarbonyl compound known to induce cellular injury and cytoxicity, including apoptosis in vascular cells. Vascular endothelial cell apoptosis has been implicated in the pathophysiology and progression of atherosclerosis. We investigated whether the advanced glycation end-product inhibitor LR-90 could prevent MGO-induced apoptosis in human umbilical vascular endothelial cells (HUVECs). HUVECs were pre-treated with LR-90 and then stimulated with MGO. Cell morphology, cytotoxicity and apoptosis were evaluated by light microscopy, MTT assay, and Annexin V-FITC and propidium iodide double staining, respectively. Levels of Bax, Bcl-2, cytochrome c, mitogen-activated protein kinases (MAPKs) and caspase activities were assessed by Western blotting. Reactive oxygen species (ROS) generation and mitochondrial membrane potential (MMP) were measured with fluorescent probes. LR-90 dose-dependently prevented MGO-associated HUVEC cytotoxicity and apoptotic biochemical changes such as loss of MMP, increased Bax/Bcl-2 protein ratio, mitochondrial cytochrome c release and activation of caspase-3 and 9. Additionally, LR-90 blocked intracellular ROS formation and MAPK (p44/p42, p38, JNK) activation, though the latter seem to be not directly involved in MGO-induced HUVEC apoptosis. LR-90 prevents MGO-induced HUVEC apoptosis by inhibiting ROS and associated mitochondrial-dependent apoptotic signaling cascades, suggesting that LR-90 possess cytoprotective ability which could be beneficial in prevention of diabetic related-atherosclerosis. PMID:24615331

d-limonene exhibits antitumor activity by inducing autophagy and apoptosis in lung cancer.

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Yu, Xiao; Lin, Hongyan; Wang, Yu; Lv, Wenwen; Zhang, Shuo; Qian, Ying; Deng, Xiaobei; Feng, Nannan; Yu, Herbert; Qian, Biyun

2018-01-01

d-limonene is a plant extract with widespread application, and it has been recently reported to have antiproliferative and proapoptotic effects on cancer cells. However, the mechanisms by which d-limonene achieves these effects, especially in lung cancer, are not entirely clear. Therefore, the goal of this study was to examine the effects of d-limonene on lung cancer and explore its mechanisms of action. We examined the therapeutic effects of d-limonene on lung cancer cells and in a xenograft animal model by characterizing its effects on the pathways of apoptosis and autophagy. Cell proliferation was measured using the Cell Counting Kit-8, and apoptosis was determined by flow cytometric analysis. Levels of LC3 puncta, an autophagy marker, were analyzed by laser scanning confocal microscopy. Autophagy and apoptosis-related gene expression were assessed by real-time quantitative polymerase chain reaction and Western blot. d-limonene inhibited the growth of lung cancer cells and suppressed the growth of transplanted tumors in nude mice. Expression of apoptosis and autophagy-related genes were increased in tumors after treatment with d-limonene. Furthermore, the use of chloroquine, an autophagy inhibitor, and knockdown of the atg5 gene, suppressed the apoptosis induced by d-limonene. d-limonene may have a therapeutic effect on lung cancer as it can induce apoptosis of lung cancer cells by promoting autophagy.

Hypercholesterolemia aggravates myocardial ischemia reperfusion injury via activating endoplasmic reticulum stress-mediated apoptosis.

Science.gov (United States)

Wu, Nan; Zhang, Xiaowen; Jia, Pengyu; Jia, Dalin

2015-12-01

The effect of hypercholesterolemia on myocardial ischemia reperfusion injury (MIRI) is in controversy and the underlying mechanism is still not well understood. In the present study, we firstly detected the effects of hypercholesterolemia on MIRI and the role of endoplasmic reticulum (ER) stress-mediated apoptosis pathway in this process. The infarct size was determined by TTC staining, and apoptosis was measured by the TUNEL method. The marker proteins of ER stress response and ER stress-mediated apoptosis pathway were detected by Western blot. The results showed that high cholesterol diet-induced hypercholesterolemia significantly increased the myocardial infarct size, the release of myocardium enzyme and the ratio of apoptosis, but did not affect the recovery of cardiac function. Moreover, hypercholesterolemia also remarkably up-regulated the expressions of ER stress markers (glucose-regulated protein 78 and calreticulin) and critical molecules in ER stress-mediated apoptosis pathway (CHOP, caspase 12, phospho-JNK). In conclusion, our study demonstrated that hypercholesterolemia enhanced myocardial vulnerability/sensitivity to ischemia reperfusion injury involved in aggravation the ER stress and activation of ER stress-mediated apoptosis pathway and it gave us a new insight into the underlying mechanisms associated with hypercholesterolemia-induced exaggerated MIRI and also provided a novel target for preventing MIRI in the presence of hypercholesterolemia. Copyright © 2015 Elsevier Inc. All rights reserved.

Apoptosis by antitumor agents and other factors in relation to cell cycle checkpoints

International Nuclear Information System (INIS)

Kondo, Sohei

1995-01-01

More than a cancer patients died in 1993 after treatment with antineoplastic derivatives of 5-fluorouracil and the antiherpes drug Sorivudine. This paper gives a short review of previous reports showing that killing of cells by 5-fluorouracil and other antitumor agents, including radiation at high doses, results from activation of apoptosis in the G2 phase. On the other hand, apoptosis of lymphocytes by radiation at low doses and treatment with other agents is known to occur in the G1 phase. The cells dying in the G1 or G2 phase could share the same final self-killing steps. For these common steps, I assume a mitotic catastrophe model, in which commitment to self-killing results from premature activation of the mitosis machinery, and propose a concept of a 'G1/G2 death circuit' for cells dying in the G1/G2 phase by short circuit to the M phase. Based on this model, reported modes of cell death, spontaneously occurring or after treatment with various agents, are classified by the phase of dying cells. The associations of incomplete apoptosis with production of chromosomal aberrations and prevention of tumorigenesis by complete apoptosis of carcinogen-treated cells are discussed. A presumptive rule for differentiation of G1 apoptosis and G2 apoptosis is proposed. (author)

Roscovitine sensitizes leukemia and lymphoma cells to tumor necrosis factor-related apoptosis-inducing ligand-induced apoptosis

Czech Academy of Sciences Publication Activity Database

Molinsky, J.; Klánová, M.; Koc, Michal; Beranová, Lenka; Anděra, Ladislav; Ludvíková, Z.; Bohmova, M.; Gasova, Z.; Strnad, Miroslav; Ivánek, R.; Trněný, M.; Nečas, E.; Živný, J.; Klener, P.

2013-01-01

Roč. 54, č. 2 (2013), s. 372-380 ISSN 1042-8194 R&D Projects: GA MZd NS10287 Institutional research plan: CEZ:AV0Z50380511 Institutional support: RVO:68378050 Keywords : roscovitine * TRAIL * synergism * apoptosis * leukemia * lymphoma Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.605, year: 2013

HIV/SIV infection primes monocytes and dendritic cells for apoptosis.

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Mireille Laforge

2011-06-01

Full Text Available Subversion or exacerbation of antigen-presenting cells (APC death modulates host/pathogen equilibrium. We demonstrated during in vitro differentiation of monocyte-derived macrophages and monocyte-derived dendritic cells (DCs that HIV sensitizes the cells to undergo apoptosis in response to TRAIL and FasL, respectively. In addition, we found that HIV-1 increased the levels of pro-apoptotic Bax and Bak molecules and decreased the levels of anti-apoptotic Mcl-1 and FLIP proteins. To assess the relevance of these observations in the context of an experimental model of HIV infection, we investigated the death of APC during pathogenic SIV-infection in rhesus macaques (RMs. We demonstrated increased apoptosis, during the acute phase, of both peripheral blood DCs and monocytes (CD14(+ from SIV(+RMs, associated with a dysregulation in the balance of pro- and anti-apoptotic molecules. Caspase-inhibitor and death receptors antagonists prevented apoptosis of APCs from SIV(+RMs. Furthermore, increased levels of FasL in the sera of pathogenic SIV(+RMs were detected, compared to non-pathogenic SIV infection of African green monkey. We suggest that inappropriate apoptosis of antigen-presenting cells may contribute to dysregulation of cellular immunity early in the process of HIV/SIV infection.

Influenza virus induces apoptosis via BAD-mediated mitochondrial dysregulation.

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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.

alpha-Amanitin induced apoptosis in primary cultured dog hepatocytes.

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Adam Szelag

2010-06-01

Full Text Available Amatoxin poisoning is caused by mushroom species belonging to the genera Amanita, Galerina and Lepiota with the majority of lethal mushroom exposures attributable to Amanita phalloides. High mortality rate in intoxications with these mushrooms is principally a result of the acute liver failure following significant hepatocyte damage due to hepatocellular uptake of amatoxins. A wide variety of amatoxins have been isolated; however, alpha-amanitin (alpha-AMA appears to be the primary toxin. Studies in vitro and in vivo suggest that alpha-AMA does not only cause hepatocyte necrosis, but also may lead to apoptotic cell death. The objective of this study was to evaluate the complex hepatocyte apoptosis in alpha-AMA cytotoxicity. All experiments were performed on primary cultured canine hepatocytes. The cells were incubated for 12 h with alpha-AMA at a final concentration of 1, 5, 10 and 20 microM. Viability test (MTT assay, apoptosis evaluation (TUNEL reaction, detection of DNA laddering and electron microscopy were performed at 6 and 12 h of exposure to alpha-AMA. There was a clear correlation between hepatocyte viability, concentration of alpha-AMA and time of exposure to this toxin. The decline in cultured dog hepatocyte viability during the exposure to alpha-AMA is most likely preceded by enhanced cellular apoptosis. Our results demonstrate that apoptosis might contribute to pathogenesis of the severe liver injury in the course of amanitin intoxication, particularly during the early phase of poisoning.

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

Fast neutrons-induced apoptosis is Fas-independent in lymphoblastoid cells

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Fischer, Barbara; Benzina, Sami; Jeannequin, Pierre; Dufour, Patrick; Bergerat, Jean-Pierre; Denis, Jean-Marc; Gueulette, John; Bischoff, Pierre L.

2005-01-01

We have previously shown that ionizing radiation-induced apoptosis in human lymphoblastoid cells differs according to their p53 status, and that caspase 8-mediated cleavage of BID is involved in the p53-dependent pathway. In the present study, we investigated the role of Fas signaling in caspase 8 activation induced by fast neutrons irradiation in these cells. Fas and FasL expression was assessed by flow cytometry and by immunoblot. We also measured Fas aggregation after irradiation by fluorescence microscopy. We found a decrease of Fas expression after irradiation, but no change in Fas ligand expression. We also showed that, in contrast to the stimulation of Fas by an agonistic antibody, Fas aggregation did not occur after irradiation. Altogether, our data strongly suggest that fast neutrons induced-apoptosis is Fas-independent, even in p53-dependent apoptosis

Myeloperoxidase serves as a redox switch that regulates apoptosis in epithelial ovarian cancer.

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Saed, Ghassan M; Ali-Fehmi, Rouba; Jiang, Zhong L; Fletcher, Nicole M; Diamond, Michael P; Abu-Soud, Husam M; Munkarah, Adnan R

2010-02-01

Resistance to apoptosis is a key feature of cancer cells and is believed to be regulated by nitrosonium ion (NO(+))-induced S-nitrosylation of key enzymes. Nitric oxide (NO), produced by inducible nitric oxide synthase (iNOS), is utilized by MPO to generated NO(+). We sought to investigate the expression of myeloperoxidase (MPO) and iNOS in epithelial ovarian cancer (EOC) and determine their effect on S-nitrosylation of caspase-3 and its activity as well as apoptosis. MPO and iNOS expression were determined using immunofluorescence in SKOV-3 and MDAH-2774 and EOC tissue sections. S-nitrosylation of caspase-3 and its activity, levels of MPO and iNOS, as well as apoptosis, were evaluated in the EOC cells before and after silencing MPO or iNOS genes with specific siRNA probes utilizing real-time RT-PCR, ELISA, and TUNEL assays. MPO and iNOS are expressed in EOC cell lines and in over 60% of invasive EOC cases with no expression in normal ovarian epithelium. Indeed, silencing of MPO or iNOS gene expression resulted in decreased S-nitrosylation of caspase-3, increased caspase-3 activity, and increased apoptosis but with a more significant effect when silencing MPO. MPO and iNOS are colocalized to the same cells in EOC but not in the normal ovarian epithelium. Silencing of either MPO or iNOS significantly induced apoptosis, highlighting their role as a redox switch that regulates apoptosis in EOC. Understanding the mechanisms by which MPO functions as a redox switch in regulating apoptosis in EOC may lead to future diagnostic tools and therapeutic interventions. Copyright 2009 Elsevier Inc. All rights reserved.

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

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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.

Crosstalk between Apoptosis and Autophagy: Molecular Mechanisms and Therapeutic Strategies in Cancer

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Abdelouahid El-Khattouti

2013-01-01

Full Text Available Both apoptosis and autophagy are highly conserved processes that besides their role in the maintenance of the organismal and cellular homeostasis serve as a main target of tumor therapeutics. Although their important roles in the modulation of tumor therapeutic strategies have been widely reported, the molecular actions of both apoptosis and autophagy are counteracted by cancer protective mechanisms. While apoptosis is a tightly regulated process that is implicated in the removal of damaged or unwanted cells, autophagy is a cellular catabolic pathway that is involved in lysosomal degradation and recycling of proteins and organelles, and thereby is considered an important survival/protective mechanism for cancer cells in response to metabolic stress or chemotherapy. Although the relationship between autophagy and cell death is very complicated and has not been characterized in detail, the molecular mechanisms that control this relationship are considered to be a relevant target for the development of a therapeutic strategy for tumor treatment. In this review, we focus on the molecular mechanisms of apoptosis, autophagy, and those of the crosstalk between apoptosis and autophagy in order to provide insight into the molecular mechanisms that may be essential for the balance between cell survival and death as well as their role as targets for the development of novel therapeutic approaches.

Inducing death in tumor cells: roles of the inhibitor of apoptosis proteins.

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Finlay, Darren; Teriete, Peter; Vamos, Mitchell; Cosford, Nicholas D P; Vuori, Kristiina

2017-01-01

The heterogeneous group of diseases collectively termed cancer results not just from aberrant cellular proliferation but also from a lack of accompanying homeostatic cell death. Indeed, cancer cells regularly acquire resistance to programmed cell death, or apoptosis, which not only supports cancer progression but also leads to resistance to therapeutic agents. Thus, various approaches have been undertaken in order to induce apoptosis in tumor cells for therapeutic purposes. Here, we will focus our discussion on agents that directly affect the apoptotic machinery itself rather than on drugs that induce apoptosis in tumor cells indirectly, such as by DNA damage or kinase dependency inhibition. As the roles of the Bcl-2 family have been extensively studied and reviewed recently, we will focus in this review specifically on the inhibitor of apoptosis protein (IAP) family. IAPs are a disparate group of proteins that all contain a baculovirus IAP repeat domain, which is important for the inhibition of apoptosis in some, but not all, family members. We describe each of the family members with respect to their structural and functional similarities and differences and their respective roles in cancer. Finally, we also review the current state of IAPs as targets for anti-cancer therapeutics and discuss the current clinical state of IAP antagonists.

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

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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.

Involvement of caspase-dependent and -independent apoptotic pathways in cisplatin-induced apoptosis

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Liu, Lei; Zhang, Yingjie; Wang, Xianwang

2009-02-01

Cisplatin, an efficient anticancer agent, can trigger multiple apoptotic pathways in cancer cells. However, the signal transduction pathways in response to cisplatin-based chemotherapy are complicated, and the mechanism is not fully understood. In current study, we showed that, during cisplatin-induced apoptosis of human lung adenocarcinoma cells, both the caspase-dependent and -independent pathways were activated. Herein, we reported that after cisplatin treatment, the activities of caspase-9/-3 were sharply increased; pre-treatment with Z-LEHD-fmk (inhibitor of caspase-9), Z-DEVD-fmk (inhibitor of caspase-3), and Z-VAD-fmk (a pan-caspase inhibitor) increased cell viability and decreased apoptosis, suggesting that caspase-mediated apoptotic pathway was activated following cisplatin treatment. Confocal imaging of the cells transfected with AIF-GFP demonstrated that AIF release occurred about 9 h after cisplatin treatment. The event proceeded progressively over time, coinciding with a nuclear translocation and lasting for more than 2 hours. Down-regulation of AIF by siRNA also significantly increased cell viability and decreased apoptosis, these results suggested that AIF-mediated caspase-independent apoptotic pathway was involved in cispatin-induced apoptosis. In conclusion, the current study demonstrated that both caspase-dependent and -independent apoptotic pathways were involved in cisplatin-induced apoptosis in human lung adenocarcinoma cells.

CD4+ lymphocytes control gut epithelial apoptosis and mediate survival in sepsis.

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Stromberg, Paul E; Woolsey, Cheryl A; Clark, Andrew T; Clark, Jessica A; Turnbull, Isaiah R; McConnell, Kevin W; Chang, Katherine C; Chung, Chun-Shiang; Ayala, Alfred; Buchman, Timothy G; Hotchkiss, Richard S; Coopersmith, Craig M

2009-06-01

Lymphocytes help determine whether gut epithelial cells proliferate or differentiate but are not known to affect whether they live or die. Here, we report that lymphocytes play a controlling role in mediating gut epithelial apoptosis in sepsis but not under basal conditions. Gut epithelial apoptosis is similar in unmanipulated Rag-1(-/-) and wild-type (WT) mice. However, Rag-1(-/-) animals have a 5-fold augmentation in gut epithelial apoptosis following cecal ligation and puncture (CLP) compared to septic WT mice. Reconstitution of lymphocytes in Rag-1(-/-) mice via adoptive transfer decreases intestinal apoptosis to levels seen in WT animals. Subset analysis indicates that CD4(+) but not CD8(+), gammadelta, or B cells are responsible for the antiapoptotic effect of lymphocytes on the gut epithelium. Gut-specific overexpression of Bcl-2 in transgenic mice decreases mortality following CLP. This survival benefit is lymphocyte dependent since gut-specific overexpression of Bcl-2 fails to alter survival when the transgene is overexpressed in Rag-1(-/-) mice. Further, adoptively transferring lymphocytes to Rag-1(-/-) mice that simultaneously overexpress gut-specific Bcl-2 results in improved mortality following sepsis. Thus, sepsis unmasks CD4(+) lymphocyte control of gut apoptosis that is not present under homeostatic conditions, which acts as a key determinant of both cellular survival and host mortality.

Mechanisms of decreased intestinal epithelial proliferation and increased apoptosis in murine acute lung injury.

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Husain, Kareem D; Stromberg, Paul E; Woolsey, Cheryl A; Turnbull, Isaiah R; Dunne, W Michael; Javadi, Pardis; Buchman, Timothy G; Karl, Irene E; Hotchkiss, Richard S; Coopersmith, Craig M

2005-10-01

The aim of this study was to determine the effects of acute lung injury on the gut epithelium and examine mechanisms underlying changes in crypt proliferation and apoptosis. The relationship between severity and timing of lung injury to intestinal pathology was also examined. Randomized, controlled study. University research laboratory. Genetically inbred mice. Following induction of acute lung injury, gut epithelial proliferation and apoptosis were assessed in a) C3H/HeN wild-type and C3H/HeJ mice, which lack functional Toll-like receptor 4 (n = 17); b) C57Bl/6 mice that received monoclonal anti-tumor necrosis factor-alpha or control antibody (n = 22); and c) C57Bl/6 wild-type and transgenic mice that overexpress Bcl-2 in their gut epithelium (n = 21). Intestinal epithelial proliferation and death were also examined in animals with differing degrees of lung inflammation (n = 24) as well as in a time course analysis following a fixed injury (n = 18). Acute lung injury caused decreased proliferation and increased apoptosis in crypt epithelial cells in all animals studied. C3H/HeJ mice had higher levels of proliferation than C3H/HeN animals without additional changes in apoptosis. Anti-tumor necrosis factor-alpha antibody had no effect on gut epithelial proliferation or death. Overexpression of Bcl-2 did not change proliferation despite decreasing gut apoptosis. Proliferation and apoptosis were not correlated to severity of lung injury, as gut alterations were lost in mice with more severe acute lung injury. Changes in both gut epithelial proliferation and death were apparent within 12 hrs, but proliferation was decreased 36 hrs following acute lung injury while apoptosis returned to normal. Acute lung injury causes disparate effects on crypt proliferation and apoptosis, which occur, at least in part, through differing mechanisms involving Toll-like receptor 4 and Bcl-2. Severity of lung injury does not correlate with perturbations in proliferation or death in the

Ghrelin ameliorates the human alveolar epithelial A549 cell apoptosis induced by lipopolysaccharide

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Huang, Chunrong; Zheng, Haichong; He, Wanmei; Lu, Guifang; Li, Xia; Deng, Yubin; Zeng, Mian

2016-01-01

Ghrelin is a gastric acyl-peptide that plays an inhibitory role in cell apoptosis. Herein we investigate the protective effects of ghrelin in LPS-induced apoptosis of human alveolar epithelial A549 cells, along with the possible molecular mechanisms. LPS exposure impaired cell viability and increased apoptosis of A549 cells significantly in concentration- and time-dependent manners embodied in increased Bax and cleaved caspase-3 production, coupled with decreased Bcl-2 levels. Simultaneously, LPS remarkably decreased the expression of phosphatidylinositol 3 kinase/protein kinase B (PI3K/Akt) and extracellular signal-regulated kinas (ERK) in A549 cells. However, ghrelin'pretreatment ameliorated LPS-caused alterations in the ratio of Bax/Bcl-2 and cleaved caspase-3 expression, whereas activated the PI3K/Akt and ERK signaling. These results demonstrate that ghrelin lightens LPS-induced apoptosis of human alveolar epithelial cells partly through activating the PI3K/Akt and ERK pathway and thereby might benefit alleviating septic ALI. -- Graphical abstract: Ghrelin ameliorates the human alveolar epithelial A549 cells apoptosis induced by lipopolysaccharide partly through activating the PI3K/Akt and ERK pathway. Display Omitted -- Highlights: •It has been observed that LPS insult significantly increased apoptosis in A549 cells. •Both Akt and ERK signaling are critical adapter molecules to mediate the ghrelin-mediated proliferative effect. •Ghrelin may have a therapeutic effect in the prevention of LPS-induced apoptosis.

Ghrelin ameliorates the human alveolar epithelial A549 cell apoptosis induced by lipopolysaccharide

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Huang, Chunrong; Zheng, Haichong; He, Wanmei; Lu, Guifang; Li, Xia [Department of Medical Intensive Care Unit, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080 (China); Deng, Yubin, E-mail: dengyub@mail.sysu.edu.cn [Research Center of Translational Medicine, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080 (China); Zeng, Mian, E-mail: zengmian2004@163.com [Department of Medical Intensive Care Unit, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080 (China)

2016-05-20

Ghrelin is a gastric acyl-peptide that plays an inhibitory role in cell apoptosis. Herein we investigate the protective effects of ghrelin in LPS-induced apoptosis of human alveolar epithelial A549 cells, along with the possible molecular mechanisms. LPS exposure impaired cell viability and increased apoptosis of A549 cells significantly in concentration- and time-dependent manners embodied in increased Bax and cleaved caspase-3 production, coupled with decreased Bcl-2 levels. Simultaneously, LPS remarkably decreased the expression of phosphatidylinositol 3 kinase/protein kinase B (PI3K/Akt) and extracellular signal-regulated kinas (ERK) in A549 cells. However, ghrelin'pretreatment ameliorated LPS-caused alterations in the ratio of Bax/Bcl-2 and cleaved caspase-3 expression, whereas activated the PI3K/Akt and ERK signaling. These results demonstrate that ghrelin lightens LPS-induced apoptosis of human alveolar epithelial cells partly through activating the PI3K/Akt and ERK pathway and thereby might benefit alleviating septic ALI. -- Graphical abstract: Ghrelin ameliorates the human alveolar epithelial A549 cells apoptosis induced by lipopolysaccharide partly through activating the PI3K/Akt and ERK pathway. Display Omitted -- Highlights: •It has been observed that LPS insult significantly increased apoptosis in A549 cells. •Both Akt and ERK signaling are critical adapter molecules to mediate the ghrelin-mediated proliferative effect. •Ghrelin may have a therapeutic effect in the prevention of LPS-induced apoptosis.

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

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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.

Use of the microculture kinetic assay of apoptosis to determine chemosensitivities of leukemias.

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Kravtsov, V D; Greer, J P; Whitlock, J A; Koury, M J

1998-08-01

Chemotherapeutic agents exert their antitumor effects by inducing apoptosis. The microculture kinetic (MiCK) assay provides an automated, continuous means of monitoring apoptosis in a cell population. We used the MiCK assay to determine the chemosensitivities of the human promyelocytic HL-60 and lymphoblastic CEM cell lines and leukemia cells freshly isolated from patients with acute nonlymphocytic (ANLL) or acute lymphocytic (ALL) leukemias. Continuous monitoring of apoptosis in the MiCK assay permits determination of the time to the maximum apoptosis (Tm) and its two components which are initiation time (Ti) and development time (Td). Duration of the three timing components of apoptosis varies from hours to days depending on the drug, drug concentration, and type of target cells. In the MiCK assay, the extent of apoptosis is reported in kinetic units of apoptosis. Kinetic units are determined by the slope of the curve created when optical density caused by cell blebbing is plotted as a function of time. Using the leukemia cell lines, we define the relationship between kinetic units determined by the MiCK assay and the percentage of morphologically apoptotic cells in the culture. Flow cytometry analysis of apoptosis in Annexin-V-fluorescein isothiocyanate-labeled preparations of HL-60 and CEM cells was also used to compare with data obtained by the MiCK assay. The feasibility of the MiCK assay of apoptosis as a chemosensitivity test was confirmed by its comparison with a 3H-thymidine incorporation assay. We show that samples from 10 ANLL and ALL patients patients tested for sensitivity to various doses of idarubicin (IDR), daunorubicin (DNR), or mitoxantrone (MTA) gave the same percentages of apoptotic cells when calculated by the MiCK assay as when determined by morphological analysis. The MiCK assay was used for dose-response analyses of the sensitivities to IDR, DNR, and MTA of leukemia cells from 4 other patients (2 ANLL and 2 ALL). The results from both cell

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

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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.

Apoptosis Gene Hunting Using Retroviral Expression Cloning: Identification of Vacuolar ATPase Subunit E

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Claire L. Anderson

2003-01-01

Full Text Available Over the past 10-15 years there has been an explosion of interest in apoptosis. The delayed realisation that cell death is an essential part of life for any multicellular organism has meant that, despite the recent and rapid developments of the last decade, the precise biochemical pathways involved in apoptosis remain incomplete and potentially novel genes may, as yet, remain undiscovered. The hunt is therefore on to bridge the remaining gaps in our knowledge. Our contribution to this research effort utilises a functional cloning approach to isolate important regulatory genes involved in apoptosis. This mini-review focuses on the use and advantages of a retroviral expression cloning strategy and describes the isolation and identification of one such potential apoptosis regulatory gene, namely that encoding vacuolar ATPase subunit E.

Minyak ikan Lemuru (Sardinella longicep menurunkan apoptosis osteoblas pada tulang alveolaris tikus wistar (Fish oil of Lemuru (Sardinella longicep reduced the osteoblast apoptosis in wistar rat alveolar bone

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Didin Erma Indahyani

2013-12-01

Full Text Available Background: Periodontal disease is caused by periodontopatogen bacteria resulting the alveolar bone damage. The decrease of osteoblasts and the increased of osteoclasts can cause bone destruction. The decrease of osteoblasts, due to a disturbance of differentiation, proliferation and apoptosis. Inflammatory mediators are prostaglandin E2 (PGE2, interleukin-1 (IL-1, IL-6 also tumor necrosis alpha (TNF-α stimulates osteoblast apoptosis through gene expression, signaling molecules and receptor-forming osteoblasts. Fish oil of Lemuru, which is widely encountered in Indonesian coast, containing n-3 poly unsaturated fatty acids (n-3 PUFAs are quite high. Consumption of fish oil shown to reduce the expression of PGE2, IL-1, IL-6 and TNF-α. Purpose: The purpose of this study was to examine the effect of Lemuru (Sardinella longicep fish oil on osteoblast apoptosis of rat alveolar bone induced periodontal infection. Methods: Thirty Wistar rats, male, age 5 days, divided into 3 groups: group I rats induced with normal saline, group II rats induced by LPS, and group III rats induced with lemuru fish oil and LPS. Each group was divided into 2 sub-groups that would be sacrified at 13 days and 21 days of age. Fish oil was given at a dose 1ml/300-350 grams. Lipopolysaccharide (LPS induced with the purpose to cause periodontal infection in the maxillary buccal fold molar region with dose 5μl LPS/PBS 0.03 ml. After decapitation and decalcification, the maxilla was cut in 5μm thickness. Apoptosis was analyzed on DNA and detected by TUNEL reaction (transferase-mediated digoxigenin-deoxy-UTP nick end labeling. Results: The results showed that apoptosis of osteoblast cells was significantly smaller in rats induced by Lemuru fish oil. Conclusion: The study showed that Lemuru fish oil reduced the osteoblast apoptosis of rats alveolar bone induced periodontal infection by LPS.Latar belakang: Penyakit periodontal akibat bakteri peridontopatogen, menyebabkan

Regulation of singlet oxygen-induced apoptosis by cytosolic NADP+-dependent isocitrate dehydrogenase.

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Kim, Sun Yee; Lee, Su Min; Tak, Jean Kyoung; Choi, Kyeong Sook; Kwon, Taeg Kyu; Park, Jeen-Woo

2007-08-01

Singlet oxygen is a highly reactive form of molecular oxygen that may harm living systems by oxidizing critical cellular macromolecules and it also promotes deleterious processes such as cell death. Recently, we demonstrated that the control of redox balance and the cellular defense against oxidative damage are the primary functions of cytosolic NADP(+)-dependent isocitrate dehydrogenase (IDPc) through supplying NADPH for antioxidant systems. In this report, we demonstrate that modulation of IDPc activity in HL-60 cells regulates singlet oxygen-induced apoptosis. When we examined the protective role of IDPc against singlet oxygen-induced apoptosis with HL-60 cells transfected with the cDNA for mouse IDPc in sense and antisense orientations, a clear inverse relationship was observed between the amount of IDPc expressed in target cells and their susceptibility to apoptosis. The results suggest that IDPc plays an important protective role in apoptosis of HL-60 cells induced by singlet oxygen.

The pathway of estradiol-induced apoptosis in patients with systemic lupus erythematosus.

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Rastin, Maryam; Hatef, Mohammad Reza; Tabasi, Nafisseh; Mahmoudi, Mahmoud

2012-03-01

Systemic lupus erythematosus (SLE) is a disease with unknown etiology. The pathologic role of sex hormones and apoptosis in SLE has often been discussed. We studied the effects of estradiol in the pathway of induced apoptosis in Iranian SLE patients. T lymphocytes from 35 SLE patients and 20 age-matched controls were isolated and cultured in the presence of 10(-8) M 17-β estradiol. The expression levels of Fas, Fas ligand (FasL), Bcl-2, caspase-8, and caspase-9 mRNAs were determined semiquantitatively in comparison to the expression level of beta actin RNA. Estradiol exposure did not have any significant effects on the expression levels of Fas, Bcl-2, and caspase-9 in SLE patients and controls. However, the expression levels of FasL and caspase-8 were significantly increased in SLE patients, but not in controls. This suggests the probable involvement of extrinsic apoptosis pathway in estradiol-induced apoptosis in SLE.

Protective Effect of Edaravone against Carbon Monoxide Induced Apoptosis in Rat Primary Cultured Astrocytes

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Xiaodan Xu

2017-01-01

Full Text Available Objective. To observe the protective effect of edaravone (Eda on astrocytes after prolonged exposure to carbon monoxide (CO and further to investigate the potential mechanisms of Eda against CO-induced apoptosis. Methods. The rat primary cultured astrocytes were cultured in vitro and exposed to 1% CO for 24 h after being cultured with different concentrations of Eda. MTT assay was used to detect the cytotoxicity of CO. Flow cytometry was used to detect the apoptosis rate, membrane potential of mitochondria, and ROS level. The mRNA and protein expressions of Bcl-2, Bax, and caspase-3 were assessed by real-time PCR and Western blotting analysis, respectively. Results. Eda can significantly suppress cytotoxicity of CO, and it can significantly increase membrane potential of mitochondria and Bcl-2 expressions and significantly suppress the apoptosis rate, ROS level, Bax, and caspase-3 expressions. Conclusion. Eda protects against CO-induced apoptosis in rat primary cultured astrocytes through decreasing ROS production and subsequently inhibiting mitochondrial apoptosis pathway.

Effect of low dose X-ray irradiation on apoptosis in spermatogenic cells of mouse testes

International Nuclear Information System (INIS)

Liu Guangwei; Liu Shuchun; Lu Zhe; Gong Shouliang

2003-01-01

To study the effects of low dose radiation (LDR) with different doses of X-rays on the apoptosis in spermatogenic cells of male Kunming mouse testes. The time-effect and dose-effect of apoptosis in the different stages of spermatogenic cell cycles of mouse testis after LDR with different doses of X-rays were studied with light microscope using the methods of TdT-mediated dUTP nick end labeling (TUNEL) and HE staining. The apoptosis of spermatogenic cells induced by LDR had a remarkable regularity in cell types. When the dose was 0.025 Gy, spermatogonium apoptosis was taken as main. With the dose increase of irradiation (0.025-0.2 Gy), spermatocytes also showed an apoptotic change, but the apoptotic rate of spermatogonia was significantly higher than that of spermatocytes. Moreover, the apoptosis of spermatids and spermatozoa scarcely occurred after irradiation with low dose. The apoptosis of spermatogenic cells induced by LDR has a regular change, which provides a further experimental evidence for the mechanism study of hormesis by LDR

Apoptosis and mitosis as prognostic factors in pathologically staged N1 nonsmall cell lung cancer

International Nuclear Information System (INIS)

Komaki, Ritsuko; Fujii, Takashi; Perkins, Penny; Ro, Jae Y.; Allen, Pamela K.; Mason, Kathryn A.; Mountain, Clifton F.; Milas, Luka

1996-01-01

Purpose: This study aimed to establish whether spontaneous apoptosis or mitosis has prognostic value among patients with pathologically staged N1 nonsmall cell lung carcinoma (NSCLC) treated with surgical resection with or without adjuvant therapy. Methods and Materials: Material from 173 patients who had resections between 1970 and 1988 was analyzed for apoptosis and mitosis. There were 128 men and 45 women, with a median age of 61 years. There were 86 squamous cell carcinomas (SQ), 73 adenocarcinomas (AC), 3 large-cell carcinomas (LC), 6 SQ-AC, and 5 unclassified. Patients were observed from 2 to 209 months (median 27). Actuarial methods were used to assess survival and freedom from distant metastasis. Results: In NSCLC, apoptosis was found to range from 0.2% to 2.8% (median 1.0%) and mitosis from 0 to 1.8% (median 0.4%). Tumors having higher levels of apoptosis also had higher levels of mitosis (p = 0.001). The values of neither apoptosis nor mitosis depended on size, location, differentiation of tumors, age, performance status, or weight loss of patients. However, the values of apoptosis depended on tumor histology in that high values (greater than or equal to the median) were more frequent in SQ (49%) than in AC/LC (29%) (p 0.01). The overall survival for NSCLC patients, which was 33% at 5 years, did not depend on the level of either apoptosis or mitosis. The 5-year survival of patients having SQ was higher (43%) than that of patients having AC/LC (21%) (p = 0.03). Patients with high apoptosis showed significantly better 5-year overall (p = 0.008) and DMF (p = 0.0012) survivals in the SQ group compared to the AC/LC group. High mitosis compared to low mitosis was a significantly better predictor for 5-year survival (62% vs. 29%, respectively) (p = 0.035) in the SQ. However, high mitosis was a significantly worse 5-year DMF survival predictor compared to low mitosis: 13% vs. 56%, respectively (p = 0.05) in AC/LC. In the multivariate models for AC/LC, mitosis

Glechoma longituba (Lamiaceae) alleviates apoptosis in calcium ...

African Journals Online (AJOL)

Glechoma longituba pre-treatment on cell oxidative stress and apoptosis induced by CaOx. Conclusion: ... reproduction in any medium, provided the original work is properly credited. Tropical .... kit (MaiBio, Hong Kong, China) according to the.

Local IGFBP-3 mRNA expression, apoptosis and risk of colorectal adenomas

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Omofoye Oluwaseun

2008-05-01

Full Text Available Abstract Background IGF binding protein-3 (IGFBP-3 regulates the bioavailability of insulin-like growth factors I and II, and has both anti-proliferative and pro-apoptotic properties. Elevated plasma IGFBP-3 has been associated with reduced risk of colorectal cancer (CRC, but the role of tissue IGFBP-3 is not well defined. We evaluated the association between tissue or plasma IGFBP-3 and risk of colorectal adenomas or low apoptosis. Methods Subjects were consenting patients who underwent a clinically indicated colonoscopy at UNC Hospitals and provided information on diet and lifestyle. IGFBP-3 mRNA in normal colon was assessed by real time RT-PCR. Plasma IGFBP-3 was measured by ELISA and apoptosis was determined by morphology on H & E slides. Logistic regression was used to compute odds ratio (OR and 95% confidence intervals. Results We observed a modest correlation between plasma IGFBP-3 and tissue IGFBP-3 expression (p = 0.007. There was no significant association between plasma IGFBP-3 and adenomas or apoptosis. Tissue IGFBP-3 mRNA expression was significantly lower in cases than controls. Subjects in the lowest three quartiles of tissue IGFBP-3 gene expression were more likely to have adenomas. Consistent with previous reports, low apoptosis was significantly associated with increased risk of adenomas (p = 0.003. Surprisingly, local IGFBP-3 mRNA expression was inversely associated with apoptosis. Conclusion Low expression of IGFBP-3 mRNA in normal colonic mucosa predicts increased risk of adenomas. Our findings suggest that local IGFBP-3 in the colon may directly increase adenoma risk but IGFBP-3 may act through a pathway other than apoptosis to influence adenoma risk.

Local IGFBP-3 mRNA expression, apoptosis and risk of colorectal adenomas

International Nuclear Information System (INIS)

Keku, Temitope O; Sandler, Robert S; Simmons, James G; Galanko, Joseph; Woosley, John T; Proffitt, Michelle; Omofoye, Oluwaseun; McDoom, Maya; Lund, Pauline K

2008-01-01

IGF binding protein-3 (IGFBP-3) regulates the bioavailability of insulin-like growth factors I and II, and has both anti-proliferative and pro-apoptotic properties. Elevated plasma IGFBP-3 has been associated with reduced risk of colorectal cancer (CRC), but the role of tissue IGFBP-3 is not well defined. We evaluated the association between tissue or plasma IGFBP-3 and risk of colorectal adenomas or low apoptosis. Subjects were consenting patients who underwent a clinically indicated colonoscopy at UNC Hospitals and provided information on diet and lifestyle. IGFBP-3 mRNA in normal colon was assessed by real time RT-PCR. Plasma IGFBP-3 was measured by ELISA and apoptosis was determined by morphology on H & E slides. Logistic regression was used to compute odds ratio (OR) and 95% confidence intervals. We observed a modest correlation between plasma IGFBP-3 and tissue IGFBP-3 expression (p = 0.007). There was no significant association between plasma IGFBP-3 and adenomas or apoptosis. Tissue IGFBP-3 mRNA expression was significantly lower in cases than controls. Subjects in the lowest three quartiles of tissue IGFBP-3 gene expression were more likely to have adenomas. Consistent with previous reports, low apoptosis was significantly associated with increased risk of adenomas (p = 0.003). Surprisingly, local IGFBP-3 mRNA expression was inversely associated with apoptosis. Low expression of IGFBP-3 mRNA in normal colonic mucosa predicts increased risk of adenomas. Our findings suggest that local IGFBP-3 in the colon may directly increase adenoma risk but IGFBP-3 may act through a pathway other than apoptosis to influence adenoma risk

Modeling pulmonary fibrosis by abnormal expression of telomerase/apoptosis/collagen V in experimental usual interstitial pneumonia

International Nuclear Information System (INIS)

Parra, E.R.; Pincelli, M.S.; Teodoro, W.R.; Velosa, A.P.P.; Martins, V.; Rangel, M.P.; Barbas-Filho, J.V.; Capelozzi, V.L.

2014-01-01

Limitations on tissue proliferation capacity determined by telomerase/apoptosis balance have been implicated in pathogenesis of idiopathic pulmonary fibrosis. In addition, collagen V shows promise as an inductor of apoptosis. We evaluated the quantitative relationship between the telomerase/apoptosis index, collagen V synthesis, and epithelial/fibroblast replication in mice exposed to butylated hydroxytoluene (BHT) at high oxygen concentration. Two groups of mice were analyzed: 20 mice received BHT, and 10 control mice received corn oil. Telomerase expression, apoptosis, collagen I, III, and V fibers, and hydroxyproline were evaluated by immunohistochemistry, in situ detection of apoptosis, electron microscopy, immunofluorescence, and histomorphometry. Electron microscopy confirmed the presence of increased alveolar epithelial cells type 1 (AEC1) in apoptosis. Immunostaining showed increased nuclear expression of telomerase in AEC type 2 (AEC2) between normal and chronic scarring areas of usual interstitial pneumonia (UIP). Control lungs and normal areas from UIP lungs showed weak green birefringence of type I and III collagens in the alveolar wall and type V collagen in the basement membrane of alveolar capillaries. The increase in collagen V was greater than collagens I and III in scarring areas of UIP. A significant direct association was found between collagen V and AEC2 apoptosis. We concluded that telomerase, collagen V fiber density, and apoptosis evaluation in experimental UIP offers the potential to control reepithelization of alveolar septa and fibroblast proliferation. Strategies aimed at preventing high rates of collagen V synthesis, or local responses to high rates of cell apoptosis, may have a significant impact in pulmonary fibrosis

Modeling pulmonary fibrosis by abnormal expression of telomerase/apoptosis/collagen V in experimental usual interstitial pneumonia

Energy Technology Data Exchange (ETDEWEB)

Parra, E.R.; Pincelli, M.S. [Departamento de Patologia, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Teodoro, W.R.; Velosa, A.P.P. [Disciplina de Reumatologia, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Martins, V.; Rangel, M.P.; Barbas-Filho, J.V.; Capelozzi, V.L. [Departamento de Patologia, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil)

2014-06-04

Limitations on tissue proliferation capacity determined by telomerase/apoptosis balance have been implicated in pathogenesis of idiopathic pulmonary fibrosis. In addition, collagen V shows promise as an inductor of apoptosis. We evaluated the quantitative relationship between the telomerase/apoptosis index, collagen V synthesis, and epithelial/fibroblast replication in mice exposed to butylated hydroxytoluene (BHT) at high oxygen concentration. Two groups of mice were analyzed: 20 mice received BHT, and 10 control mice received corn oil. Telomerase expression, apoptosis, collagen I, III, and V fibers, and hydroxyproline were evaluated by immunohistochemistry, in situ detection of apoptosis, electron microscopy, immunofluorescence, and histomorphometry. Electron microscopy confirmed the presence of increased alveolar epithelial cells type 1 (AEC1) in apoptosis. Immunostaining showed increased nuclear expression of telomerase in AEC type 2 (AEC2) between normal and chronic scarring areas of usual interstitial pneumonia (UIP). Control lungs and normal areas from UIP lungs showed weak green birefringence of type I and III collagens in the alveolar wall and type V collagen in the basement membrane of alveolar capillaries. The increase in collagen V was greater than collagens I and III in scarring areas of UIP. A significant direct association was found between collagen V and AEC2 apoptosis. We concluded that telomerase, collagen V fiber density, and apoptosis evaluation in experimental UIP offers the potential to control reepithelization of alveolar septa and fibroblast proliferation. Strategies aimed at preventing high rates of collagen V synthesis, or local responses to high rates of cell apoptosis, may have a significant impact in pulmonary fibrosis.

The role of hypoxia, p53, and apoptosis in human cervical carcinoma pathogenesis

International Nuclear Information System (INIS)

Kim, Charlotte Y.; Tsai, Mitchell H.; Osmanian, Cynthia; Calkins, Dennise P.; Graeber, Thomas G.; Greenspan, David L.; Kennedy, Andrew S.; Rinker, Lillian H.; Varia, Mahesh A.; DiPaolo, Joseph A.; Peehl, Donna M.; Raleigh, James A.; Giaccia, Amato J.

1997-01-01

Objective: Low oxygen tension in the tumor microenvironment may have an important role during tumor growth, and is of particular prognostic significance in human cervical carcinoma. Because some human papillomavirus (HPV) infections are associated with cervical neoplasia, the relationship between hypoxia and apoptosis in primary cervical epithelial cells containing HPV16 E6 and E7, intact HPV 16 genome, and HPV positive cervical carcinoma cell lines, was examined. In addition, the relationship between hypoxia and apoptosis in spontaneous human cervical carcinomas was determined in situ. Materials and Methods: Primary normal human cervical epithelial cells were infected with retroviral vectors containing HPV16 E6 and E7 or transfected with a plasmid containing the whole HPV 16 genome. Clones were selected in neomycin containing medium. Exponentially growing cells were incubated under aerobic conditions (20% O 2 ), anaerobic conditions (0.02% O 2 ), or irradiated with 6 Gy. Analysis of apoptotic cells was performed by staining with Hoechst dye and propidium iodide and viewing with a fluorescent microscope. To determine the level of expression of the apoptotic modulators p53 and Bax, immunoblots were performed on whole cell extracts from treated cells. A clinical tumor hypoxia study was conducted at the University of North Carolina utilizing pimonidazole, a 2-nitroimidazole compound which binds irreversibly to cellular macromolecules under low oxygen conditions. Nine patients were enrolled with biopsy proven squamous cell carcinoma of the cervix and no prior treatment. Biopsies of the gross tumor were obtained after pimonidazole infusion. Contiguous histological sections were analyzed for hypoxia using a immunohistochemical technique and for apoptosis using TUNEL. Results: In vitro, hypoxia uncoupled p53 from E6 mediated degradation, and stimulated both p53 induction and apoptosis in primary cervical epithelial cells infected with the HPV E6 and E7 genes. In contrast

Molecular Cell Biology of Apoptosis and Necroptosis in Cancer.

Science.gov (United States)

Dillon, Christopher P; Green, Douglas R

Cell death is a major mechanism to eliminate cells in which DNA is damaged, organelles are stressed, or oncogenes are overexpressed, all events that would otherwise predispose cells to oncogenic transformation. The pathways that initiate and execute cell death are complex, genetically encoded, and subject to significant regulation. Consequently, while these pathways are often mutated in malignancy, there is considerable interest in inducing cell death in tumor cells as therapy. This chapter addresses our current understanding of molecular mechanisms contributing to two cell death pathways, apoptotic cell death and necroptosis, a regulated form of necrotic cell death. Apoptosis can be induced by a wide variety of signals, leading to protease activation that dismantles the cell. We discuss the physiological importance of each apoptosis pathway and summarize their known roles in cancer suppression and the current efforts at targeting each pathway therapeutically. The intricate mechanistic link between death receptor-mediated apoptosis and necroptosis is described, as well as the potential opportunities for utilizing necroptosis in the treatment of malignancy.

Effects of electrical stimulation on cell proliferation and apoptosis.

Science.gov (United States)

Love, Maria R; Palee, Siripong; Chattipakorn, Siriporn C; Chattipakorn, Nipon

2018-03-01

The application of exogenous electrical stimulation (ES) to cells in order to manipulate cell apoptosis and proliferation has been widely investigated as a possible method of treatment in a number of diseases. Alteration of the transmembrane potential of cells via ES can affect various intracellular signaling pathways which are involved in the regulation of cellular function. Controversially, several types of ES have proved to be effective in both inhibiting or inducing apoptosis, as well as increasing proliferation. However, the mechanisms through which ES achieves this remain fairly unclear. The aim of this review was to comprehensively summarize current findings from in vitro and in vivo studies on the effects of different types of ES on cell apoptosis and proliferation, highlighting the possible mechanisms through which ES induced these effects and define the optimum parameters at which ES can be used. Through this we hope to provide a greater insight into how future studies can most effectively use ES at the clinical trial stage. © 2017 Wiley Periodicals, Inc.

The protective effect of resveratrol on human lens epithelial cells against ultraviolet-induced apoptosis

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Xue - Fang Chen

2013-06-01

Full Text Available AIM: To investigate the protective effect of resveratrol on human lens epithelial cells against ultraviolet-induced apoptosis. METHODS:Subcultured human lens epithelial cell line, ultraviolet induced cell apoptosis, 20μmol/L resveratrol pretreated cell, the indicators change was observed: rate of apoptosis was detected by flow cytometry and apoptosis-related factors of caspses-3 and caspase-9 were detected by colorimetric detection, ultrastructure changes were observed under transmission electron microscope. RESULTS: Flow cytometry instrument testing found that resveratrol can suppress the apoptosis induced by ultraviolet irradiation, caspses-3 and caspase-9 content in positive control group were significantly higher than that of the negative control group at the same time period, the difference was statistically significant(P<0.05; caspses-3 and caspase-9 content in experimental group were lower than that in the positive control group at the same time, the difference was statistically significant(P<0.05. In addition, the damage of human lens epithelial cells was alleviated with the incubation time of resveratrol elongated. CONCLUSION:Resveratrol may inhibit ultraviolet-induced apoptosis of human lens epithelial cells, it has preventive function against radioactive cataract, and it can provide reliable evidence for pursuing effective medicine to prevent and treat cataract.

High expression of markers of apoptosis in Langerhans cell histiocytosis

DEFF Research Database (Denmark)

Petersen, Bodil Laub; Lundegaard, Pia Rengtved; Bank, M I

2003-01-01

53 and the number of cells in apoptosis detected with TUNEL. Langerhans cell histiocytosis cells showed strong expression of p53 and in some cases co-expression of Fas and Fas-L. The expression of Fas-L was significantly higher in infiltrates from patients with single-system disease. The actual...... number of pathological Langerhans cells in apoptosis as estimated by TUNEL was low. CONCLUSIONS: The low number of TUNEL-reactive cells can be explained by the rapid turnover of apoptotic cells in the tissue, not leaving the apoptotic cells long enough in the tissue to be detected. The co......-expression of Fas and Fas-L in some Langerhans cells can lead to an autocrine apoptotic shortcut, mediating the death of the double-positive cells. Our findings suggest that apoptosis mediated through the Fas/Fas-L pathway may contribute to the spontaneous regression of lesions in single-system disease. A delicate...

HDAC Inhibitors Disrupt Programmed Resistance to Apoptosis During Drosophila Development

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Yunsik Kang

2017-06-01

Full Text Available We have previously shown that the ability to respond to apoptotic triggers is regulated during Drosophila development, effectively dividing the fly life cycle into stages that are either sensitive or resistant to apoptosis. Here, we show that the developmentally programmed resistance to apoptosis involves transcriptional repression of critical proapoptotic genes by histone deacetylases (HDACs. Administration of HDAC inhibitors (HDACi, like trichostatin A or suberoylanilide hydroxamic acid, increases expression of proapoptotic genes and is sufficient to sensitize otherwise resistant stages. Conversely, reducing levels of proapoptotic genes confers resistance to otherwise sensitive stages. Given that resistance to apoptosis is a hallmark of cancer cells, and that HDACi have been recently added to the repertoire of FDA-approved agents for cancer therapy, our results provide new insights for how HDACi help kill malignant cells and also raise concerns for their potential unintended effects on healthy cells.

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

Role of CD137 signaling in dengue virus-mediated apoptosis

International Nuclear Information System (INIS)

Nagila, Amar; Netsawang, Janjuree; Srisawat, Chatchawan; Noisakran, Sansanee; Morchang, Atthapan; Yasamut, Umpa; Puttikhunt, Chunya; Kasinrerk, Watchara

2011-01-01

Highlights: → For the first time the role of CD137 in dengue virus (DENV) infection. → Induction of DENV-mediated apoptosis by CD137 signaling. → Sensitization to CD137-mediated apoptosis by dengue virus capsid protein (DENV C). → Nuclear localization of DENV C is required for CD137-mediated apoptosis. -- Abstract: Hepatic dysfunction is a well recognized feature of dengue virus (DENV) infection. However, molecular mechanisms of hepatic injury are still poorly understood. A complex interaction between DENV and the host immune response contributes to DENV-mediated tissue injury. DENV capsid protein (DENV C) physically interacts with the human death domain-associated protein Daxx. A double substitution mutation in DENV C (R85A/K86A) abrogates Daxx interaction, nuclear localization and apoptosis. Therefore we compared the expression of cell death genes between HepG2 cells expressing DENV C and DENV C (R85A/K86A) using a real-time PCR array. Expression of CD137, which is a member of the tumor necrosis factor receptor family, increased significantly in HepG2 cells expressing DENV C compared to HepG2 cells expressing DENV C (R85A/K86A). In addition, CD137-mediated apoptotic activity in HepG2 cells expressing DENV C was significantly increased by anti-CD137 antibody compared to that of HepG2 cells expressing DENV C (R85A/K86A). In DENV-infected HepG2 cells, CD137 mRNA and CD137 positive cells significantly increased and CD137-mediated apoptotic activity was increased by anti-CD137 antibody. This work is the first to demonstrate the contribution of CD137 signaling to DENV-mediated apoptosis.

Role of CD137 signaling in dengue virus-mediated apoptosis

Energy Technology Data Exchange (ETDEWEB)

Nagila, Amar [Medical Molecular Biology Unit, Office for Research and Development, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok (Thailand); Department of Biochemistry, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok (Thailand); Netsawang, Janjuree [Faculty of Medical Technology, Rangsit University, Bangkok (Thailand); Srisawat, Chatchawan [Department of Biochemistry, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok (Thailand); Noisakran, Sansanee [Dengue Hemorrhagic Fever Research Unit, Office for Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok (Thailand); Medical Biotechnology Unit, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Bangkok (Thailand); Morchang, Atthapan; Yasamut, Umpa [Medical Molecular Biology Unit, Office for Research and Development, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok (Thailand); Department of Immunology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok (Thailand); Puttikhunt, Chunya [Dengue Hemorrhagic Fever Research Unit, Office for Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok (Thailand); Medical Biotechnology Unit, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Bangkok (Thailand); Kasinrerk, Watchara [Division of Clinical Immunology, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai (Thailand); Biomedical Technology Research Center, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency at Chiang Mai University, Chiang Mai (Thailand); and others

2011-07-08

Highlights: {yields} For the first time the role of CD137 in dengue virus (DENV) infection. {yields} Induction of DENV-mediated apoptosis by CD137 signaling. {yields} Sensitization to CD137-mediated apoptosis by dengue virus capsid protein (DENV C). {yields} Nuclear localization of DENV C is required for CD137-mediated apoptosis. -- Abstract: Hepatic dysfunction is a well recognized feature of dengue virus (DENV) infection. However, molecular mechanisms of hepatic injury are still poorly understood. A complex interaction between DENV and the host immune response contributes to DENV-mediated tissue injury. DENV capsid protein (DENV C) physically interacts with the human death domain-associated protein Daxx. A double substitution mutation in DENV C (R85A/K86A) abrogates Daxx interaction, nuclear localization and apoptosis. Therefore we compared the expression of cell death genes between HepG2 cells expressing DENV C and DENV C (R85A/K86A) using a real-time PCR array. Expression of CD137, which is a member of the tumor necrosis factor receptor family, increased significantly in HepG2 cells expressing DENV C compared to HepG2 cells expressing DENV C (R85A/K86A). In addition, CD137-mediated apoptotic activity in HepG2 cells expressing DENV C was significantly increased by anti-CD137 antibody compared to that of HepG2 cells expressing DENV C (R85A/K86A). In DENV-infected HepG2 cells, CD137 mRNA and CD137 positive cells significantly increased and CD137-mediated apoptotic activity was increased by anti-CD137 antibody. This work is the first to demonstrate the contribution of CD137 signaling to DENV-mediated apoptosis.

Ultraviolet B irradiation of human leukaemia HL-60 cells in vitro induces apoptosis

International Nuclear Information System (INIS)

Martin, S.J.; Cotter, T.G.

1991-01-01

UV radiation is known to be a potent agent for the induction of programmed cell death (apoptosis) in human skin. However, the mechanistic aspects of UV-induced apoptosis remain ill-defined. In this study the effects of varying periods of UV-irradiation on the human leukaemia HL-60 cell line and on five other human cell lines were investigated.HL-60 cells were found to rapidly undergo apoptosis en masse after short periods of UV-irradiation whereas prolonged exposure of these cells to this form of radiation induced a more rapid form of cell death which was suggestive of necrosis, the pathological mode of cell death. UV-induced apoptosis in cell lines was characterized by morphological changes as well as DNA fragmentation into unit multiples of ∼ 200 bp, which was indicative of endogenous endonuclease activation. This DNA fragmentation pattern was not detected in cells immediately after UV-irradiation, and was therefore not the result of direct UV-induced DNA damage. UV-induced apoptosis of the HL-60 cell line was found to require extracellular calcium and to be inhibited in a dose-dependent way by zinc added to the culture medium. (author)

Utilizing the virus-induced blocking of apoptosis in an easy baculovirus titration method.