scholarly journals Relationship between the Regulation of Caspase-8-Mediated Apoptosis and Radioresistance in Human THP-1-Derived Macrophages

2018 ◽  
Vol 19 (10) ◽  
pp. 3154 ◽  
Author(s):  
Hironori Yoshino ◽  
Haruka Konno ◽  
Koya Ogura ◽  
Yoshiaki Sato ◽  
Ikuo Kashiwakura

Radiosensitivity varies depending on the cell type; highly differentiated cells typically exhibit greater radioresistance. We recently demonstrated that human macrophages derived from THP-1 monocytic cells, which lack TP53, are highly resistant to radiation-induced apoptosis compared with undifferentiated THP-1 cells. However, the mechanisms by which THP-1 cells acquire radioresistance during differentiation remain unknown. Herein, we investigated the mechanisms by which THP-1-derived macrophages develop p53-independent radioresistance by analyzing DNA damage responses and apoptotic pathways. Analysis of γ-H2AX foci, which indicates the formation of DNA double-strand breaks (DSB), suggested that a capacity to repair DSB of macrophages is comparable to that of radiosensitive THP-1 cells. Furthermore, treatment with inhibitors against DSB repair-related proteins failed to enhance radiation-induced apoptosis in THP-1-derrived macrophages. Analysis of the apoptotic pathways showed that radiosensitive THP-1 cells undergo apoptosis through the caspase-8/caspase-3 cascade after irradiation, whereas this was not observed in the macrophages. Caspase-8 protein expression was lower in macrophages than in THP-1 cells, whereas mRNA expressions were comparable between both cell types. Co-treatment with a proteasome inhibitor and ionizing radiation effectively induced apoptosis in macrophages in a caspase-8-dependent manner. Results suggest that the regulation of caspase-8-mediated apoptosis during differentiation plays a role in the p53-independent radioresistance of THP-1-derived macrophages.

Blood ◽  
2006 ◽  
Vol 108 (2) ◽  
pp. 559-565 ◽  
Author(s):  
Inna N. Lavrik ◽  
Alexander Golks ◽  
Simone Baumann ◽  
Peter H. Krammer

Caspase-2 was reported to be involved in a number of apoptotic pathways triggered by various stimuli. However, the molecular mechanism of procaspase-2 activation in the course of apoptosis remains poorly defined. In this report, we demonstrate that procaspase-2 is recruited to the CD95 (Fas/APO-1) death-inducing signaling complex (DISC) in human T- and B-cell lines. We show that procaspase-2 is activated at the DISC on CD95 stimulation. Despite its presence at the DISC, caspase-2 does not initiate apoptosis on CD95 stimulation in caspase-8–deficient cell lines. Taken together, our data reveal that caspase-2 is activated at the DISC but does not play an initiating role in the CD95-induced apoptosis.


2017 ◽  
Vol 1 (1) ◽  
pp. 28
Author(s):  
Ferry Sandra ◽  
Meta Ariyani Sidharta

Background: Caffeic acid has been reported that when it is combined with all-trans retinoic acid, it can inhibit proliferation activity of SaOS-2 or OSA-01 cells. In addition, caffeic acid merely could reduce cell viability of SaOS-2 cells. However, there is not any study in caffeic acid's possible effect to induce apoptosis in osteosarcoma cell.Materials and Methods: MG-63 cells were cultured in Dulbecco’s Modified Eagle Medium containing 10% fetal bovine serum. Cells were treated with various concentrations of caffeic acid. Apoptosis were analyzed with Sub-G1 assay and activation of caspase-8, -9, and -3 were analyzed with immunoblotting. Caffeic acid-induced percentage of apoptotic cells and cleaved-8, -9, -3 were then statistically analyzed.Results: Sub-G1 results showed that caffeic acid significantly induced apoptosis in MG-63 osteosarcoma cells in concentration dependent manner. Immunoblotting results showed that caffeic acid induced cleavage of caspase-8, -9 and -3. Cleaved-caspase-8 and -9 were increased at 1-hour treatment of caffeic acid, while cleaved-caspase 3 was increased markedly at 6-hours treatment of caffeic acid.Conclusions: Caffeic acid induces apoptosis significantly in concentration dependent manner through caspase-dependent intrinsic apoptotic pathway.Keywords: caffeic acid, osteosarcoma, MG-63, apoptosis, caspase


2006 ◽  
Vol 203 (1) ◽  
pp. 189-201 ◽  
Author(s):  
Ronit Vogt Sionov ◽  
Orly Cohen ◽  
Shlomit Kfir ◽  
Yael Zilberman ◽  
Eitan Yefenof

The mechanisms by which glucocorticoid receptor (GR) mediates glucocorticoid (GC)-induced apoptosis are unknown. We studied the role of mitochondrial GR in this process. Dexamethasone induces GR translocation to the mitochondria in GC-sensitive, but not in GC-resistant, T cell lines. In contrast, nuclear GR translocation occurs in all cell types. Thymic epithelial cells, which cause apoptosis of the PD1.6 T cell line in a GR-dependent manner, induce GR translocation to the mitochondria, but not to the nucleus, suggesting a role for mitochondrial GR in eliciting apoptosis. This hypothesis is corroborated by the finding that a GR variant exclusively expressed in the mitochondria elicits apoptosis of several cancer cell lines. A putative mitochondrial localization signal was defined to amino acids 558–580 of human GR, which lies within the NH2-terminal part of the ligand-binding domain. Altogether, our data show that mitochondrial and nuclear translocations of GR are differentially regulated, and that mitochondrial GR translocation correlates with susceptibility to GC-induced apoptosis.


Author(s):  
Ying Tian ◽  
Liang Wang ◽  
Zhiqiang Qiu ◽  
Yulun Xu ◽  
Rongrong Hua

We reported that a high level of autophagy was initiated by oxygen-glucose deprivation (OGD) and was maintained in neurons even after oxygen-glucose deprivation followed by reoxygenation (OGD/R), accompanied by neuronal apoptosis. This study focused on autophagy-induced apoptosis and its signaling network, especially the role of endoplasmic reticulum stress (ERS). Analysis of primary cultured cortical neurons from mice showed that the autophagy-induced apoptosis depended on Caspase-8 and -9 but not Caspase-12. This finding did not mean that the endoplasmic reticulum did not participate in this process. Increases in the levels of endoplasmic reticulum (ER) biomarkers and Binding immunoglobulin protein (BiP) were induced by autophagy in OGD/R-treated neurons. In addition, as an apoptotic transcription factor induced by ER stress, C/EBP homologous protein (CHOP) expression was significantly increased in neurons after OGD/R. This result suggested that the autophagy-Bip-CHOP-caspase (8 and 9)-dependent apoptotic signaling pathway at least partly participated in autophagy-induced apoptosis in primary cortical neurons. It revealed that ER induced apoptosis in neurons suffering from OGD/R injury in an ER stress-CHOP-dependent manner rather than a caspase-12-dependent manner. However, more research on signaling or cross-linking networks and intermediate links are needed. The realization of caspase-12-independent BiP-CHOP neuronal apoptosis pathway has expanded our understanding of the neuronal apoptosis network, which may eventually provide endogenous interventional strategies for OGD/R injury after stroke.


2018 ◽  
Vol 13 (2) ◽  
pp. 1934578X1801300
Author(s):  
Xiu-cai Ma ◽  
Hui-qiang Ding ◽  
Jian-dang Shi ◽  
Long Hei ◽  
Ning-kui Niu ◽  
...  

Cinobufacini (huachansu) is a traditional Chinese medicine extracted from the skin of Bufo bufo gargarizans, which is used in clinical cancer therapy. The purpose of this study was to investigate the signaling pathways regulating cinobufacini-induced apoptosis in the osteosarcoma cell line, U2OS. We used 3-[4,5-dimethylthiazol- 2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay to evaluate the effects of cinobufacini on cell proliferation in U2OS cells. Changes in cell morphology and apoptosis were detected by TUNEL staining. The expression of apoptosis-related and Wnt/β-catenin pathway proteins was detected by immunofluorescence, RT-PCR, and western blot analysis. Our data indicated that cinobufacini significantly inhibited cell proliferation in a dose- and time-dependent manner. Marked changes in cell morphology and apoptosis rate were clearly observed after cinobufacini treatment. The Wnt/β-catenin pathway was activated, and β-catenin expression was positive in cells after treatment. Further, protein expression of bax was increased, whereas bcl-2 was decreased, resulting in an increased bax/bcl-2 ratio. Moreover, after cinobufacini treatment, the expression of Wnt/β-catenin pathway-related proteins was similar to controls. Taken together, our study indicates that cinobufacini can induce apoptosis in U2OS cells, likely through activating the Wnt/β-catenin pathway.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Li-Hua Mu ◽  
Li-Hua Wang ◽  
Teng-Fei Yu ◽  
Yu-Ning Wang ◽  
Hong Yan ◽  
...  

Triple-negative breast cancers (TNBCs) are associated with poor patient survival because of the absence of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) expressions. Our previous studies have shown that the triterpenoid saponin AG8 from Ardisia gigantifolia stapf. inhibits the proliferation of MDA-MB-231 cells. In this study, the effects of AG8 were further analyzed in different TNBC cell types: MDA-MB-231, BT-549, and MDA-MB-157 cells. AG8 inhibited the viability of MDA-MB-231, BT-549, and MDA-MB-157 cells in a dose-dependent manner and showed stronger cytotoxicity to African American (AA) and mesenchymal (M) subtypes than Caucasian (CA) and mesenchymal stem-like (MSL) subtypes, respectively. AG8 impaired the uptake of MitoTracker Red CMXRos by the mitochondria of TNBC cells in a dose-dependent manner, and this was recovered by N-acetyl-l-cysteine (NAC). AG8 affected GSH, SOD, and MDA levels of TNBC cells, but different TNBC subtypes had different sensitivities to AG8 and NAC. In addition, we found that AG8 increased the Bax/Bcl-2 ratio and the levels of cytoplasmic cytochrome c and significantly decreased phosphorylation of ERK and AKT in BT549 and MDA-MB-157 cells. AG8 elicited its anticancer effects through ROS generation, ERK and AKT activation, and by triggering mitochondrial apoptotic pathways in TNBC cells. AG8 had selective cytotoxic effects against the AA and M TNBC subtypes and markedly induced MDA-MB-157 (AA subtype) cell apoptosis through pathways that were not associated with ROS, which was different from the other two subtypes. The underlying mechanisms should be further investigated.


Cancers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 150 ◽  
Author(s):  
Hyun Lim ◽  
Moon Park ◽  
Changmin Kim ◽  
Beomku Kang ◽  
Hyo-Sook Song ◽  
...  

Though Spatholobus suberectus Dunn (SSD) has been reported to have anti-virus, anti-osteoclastogenesis, and anti-inflammation activities, its underlying anti-cancer mechanism has never been elucidated in association with the role of miR-657 in endoplasmic reticulum (ER) stress-related apoptosis to date. SSD treatment exerted cytotoxicity in U266 and U937 cells in a dose-dependent manner. Also, apoptosis-related proteins such as PARP, procaspase-3, and Bax were regulated by SSD treatment. Furthermore, Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay revealed that a number of apoptotic bodies were increased by SSD. Interestingly, the ER stress-related proteins such as p-ATF2 and CHOP were elevated by SSD. Interestingly, reactive oxygen species (ROS) generation and cytotoxicity by SSD treatment were significantly reduced by N-Acetyl-L-cysteine (NAC). Among the microRNAs (miRNAs) regulated by SSD treatment, miR-657 was most significantly reduced by SSD treatment. However, an miR-657 mimic reversed SSD-induced apoptosis by the attenuation of the expression of p-ATF2, CHOP, and PARP cleavage. Overall, these findings provide scientific evidence that miR657 is an onco-miRNA targeting the ER stress signal pathway and SSD induces apoptosis via the inhibition of miR-657, ROS, and the activation of p-ATF2 and CHOP as a potent anti-cancer agent for myeloid-originated hematological cancer.


2020 ◽  
Vol 21 (8) ◽  
pp. 2841
Author(s):  
Xun Zhou ◽  
Jamal Bouitbir ◽  
Matthias E. Liechti ◽  
Stephan Krähenbühl ◽  
Riccardo V. Mancuso

Halogenation of amphetamines and methcathinones has become a common method to obtain novel psychoactive substances (NPS) also called “legal highs”. The para-halogenated derivatives of amphetamine and methcathinone are available over the internet and have entered the illicit drug market but studies on their potential neurotoxic effects are rare. The primary aim of this study was to explore the neurotoxicity of amphetamine, methcathinone and their para-halogenated derivatives 4-fluoroamphetamine (4-FA), 4-chloroamphetamine (PCA), 4-fluoromethcathinone (4-FMC), and 4-chloromethcathinone (4-CMC) in undifferentiated and differentiated SH-SY5Y cells. We found that 4-FA, PCA, and 4-CMC were cytotoxic (decrease in cellular ATP and plasma membrane damage) for both cell types, whereby differentiated cells were less sensitive. IC50 values for cellular ATP depletion were in the range of 1.4 mM for 4-FA, 0.4 mM for PCA and 1.4 mM for 4-CMC. The rank of cytotoxicity observed for the para-substituents was chloride > fluoride > hydrogen for both amphetamines and cathinones. Each of 4-FA, PCA and 4-CMC decreased the mitochondrial membrane potential in both cell types, and PCA and 4-CMC impaired the function of the electron transport chain of mitochondria in SH-SY5Y cells. 4-FA, PCA, and 4-CMC increased the ROS level and PCA and 4-CMC induced apoptosis by the endogenous pathway. In conclusion, para-halogenation of amphetamine and methcathinone increases their neurotoxic properties due to the impairment of mitochondrial function and induction of apoptosis. Although the cytotoxic concentrations were higher than those needed for pharmacological activity, the current findings may be important regarding the uncontrolled recreational use of these compounds.


Molecules ◽  
2020 ◽  
Vol 25 (13) ◽  
pp. 3063
Author(s):  
Buthina A. Al-Oudat ◽  
Hariteja Ramapuram ◽  
Saloni Malla ◽  
Suaad A. Audat ◽  
Noor Hussein ◽  
...  

New chrysin-De-allyl-Pac-1 hybrid analogues, tethered with variable heterocyclic systems (4a–4o), were rationally designed and synthesized. The target compounds were screened for in vitro antiproliferative efficacy in the triple-negative breast cancer (TNBC) cell line, MDA-MB-231, and normal human mammary epithelial cells (HMECs). Two compounds, 4g and 4i, had the highest efficacy and selectivity towards MDA-MB-231 cells, and thus, were further evaluated by mechanistic experiments. The results indicated that both compounds 4g and 4i induced apoptosis by (1) inducing cell cycle arrest at the G2 phase in MDA-MB-231 cells, and (2) activating the intrinsic apoptotic pathways in a concentration-dependent manner. Physicochemical characterizations of these compounds suggested that they can be further optimized as potential anticancer compounds for TNBC cells. Overall, our results suggest that 4g and 4i could be suitable leads for developing novel compounds to treat TNBC.


1999 ◽  
Vol 277 (3) ◽  
pp. G702-G708 ◽  
Author(s):  
Alix de la Coste ◽  
Monique Fabre ◽  
Nathalie McDonell ◽  
Arlette Porteu ◽  
Helène Gilgenkrantz ◽  
...  

Fas ligand (CD95L) and tumor necrosis factor-α (TNF-α) are pivotal inducers of hepatocyte apoptosis. Uncontrolled activation of these two systems is involved in several forms of liver injury. Although the broad antiapoptotic action of Bcl-2 and Bcl-xL has been clearly established in various apoptotic pathways, their ability to inhibit the Fas/CD95- and TNF-α-mediated apoptotic signal has remained controversial. We have demonstrated that the expression of BCL-2 in hepatocytes protects them against Fas-induced fulminant hepatitis in transgenic mice. The present study shows that transgenic mice overexpressing[Formula: see text]in hepatocytes are also protected from Fas-induced apoptosis in a dose-dependent manner. Bcl-xL and Bcl-2 were protective without any change in the level of endogenous[Formula: see text]or Bax and inhibited hepatic caspase-3-like activity. In vivo injection of TNF-α caused massive apoptosis and death only when transcription was inhibited. Under these conditions,[Formula: see text]mice were partially protected from liver injury and death but PK-BCL-2 mice were not. A similar differential protective effect of Bcl-xL and Bcl-2 transgenes was observed when Fas/CD95 was activated and transcription blocked. These results suggest that apoptosis triggered by activation of both Fas/CD95 and TNF-α receptors is to some extent counteracted by the transcription-dependent protective effects, which are essential for the antiapoptotic activity of Bcl-2 but not of Bcl-xL. Therefore, Bcl-xL and Bcl-2 appear to have different antiapoptotic effects in the liver whose characterization could facilitate their use to prevent the uncontrolled apoptosis of hepatocytes.


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