Acrolein induces apoptosis through the death receptor pathway in A549 lung cells: role of p53This review is one of a selection of papers published in a Special Issue on Oxidative Stress in Health and Disease.

2010 ◽  
Vol 88 (3) ◽  
pp. 353-368 ◽  
Author(s):  
Julie Roy ◽  
Pragathi Pallepati ◽  
Ahmed Bettaieb ◽  
Diana A. Averill-Bates

Acrolein, a highly reactive α,β-unsaturated aldehyde, is an omnipresent environmental pollutant. Chronic and acute human exposures occur through exogenous and endogenous sources, including food, vapors of overheated cooking oil, house and forest fires, cigarette smoke, and automobile exhaust. Acrolein is a toxic byproduct of lipid peroxidation, which has been implicated in pulmonary, cardiac, and neurodegenerative diseases. This study shows that p53 is an initiating factor in acrolein-induced death receptor activation during apoptosis in A549 human lung cells. Exposure of cells to acrolein (0–50 µmol/L) mainly caused apoptosis, which was manifested by execution phase events such as condensation of nuclear chromatin, phosphatidylserine externalization, and poly(ADP-ribose) polymerase (PARP) cleavage. Levels of necrosis (~5%) were low. Acrolein triggered the death receptor pathway of apoptosis, causing elevation of Fas ligand (FasL) and translocation of adaptor protein Fas-associated death domain to the plasma membrane. Acrolein caused activation of caspase-8, caspase-2, caspase-7, and the cross-talk pathway mediated by Bid cleavage. Activation of p53 and increased expression of p53-upregulated modulator of apoptosis (PUMA) occurred in response to acrolein. FasL upregulation and caspase-8 activation were decreased by p53 inhibitor pifithrin-α and antioxidant polyethylene glycol catalase. These findings increase our knowledge about the induction of cell death pathways by acrolein, which has important implications for human health.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
D. A. Leach ◽  
A. Mohr ◽  
E. S. Giotis ◽  
E. Cil ◽  
A. M. Isac ◽  
...  

AbstractSARS-CoV-2 attacks various organs, most destructively the lung, and cellular entry requires two host cell surface proteins: ACE2 and TMPRSS2. Downregulation of one or both of these is thus a potential therapeutic approach for COVID-19. TMPRSS2 is a known target of the androgen receptor, a ligand-activated transcription factor; androgen receptor activation increases TMPRSS2 levels in various tissues, most notably prostate. We show here that treatment with the antiandrogen enzalutamide—a well-tolerated drug widely used in advanced prostate cancer—reduces TMPRSS2 levels in human lung cells and in mouse lung. Importantly, antiandrogens significantly reduced SARS-CoV-2 entry and infection in lung cells. In support of this experimental data, analysis of existing datasets shows striking co-expression of AR and TMPRSS2, including in specific lung cell types targeted by SARS-CoV-2. Together, the data presented provides strong evidence to support clinical trials to assess the efficacy of antiandrogens as a treatment option for COVID-19.


2019 ◽  
Vol 15 (9) ◽  
pp. e1007374 ◽  
Author(s):  
Anna Matveeva ◽  
Michael Fichtner ◽  
Katherine McAllister ◽  
Christopher McCann ◽  
Marc Sturrock ◽  
...  

2017 ◽  
Vol 85 (4) ◽  
Author(s):  
Georgina L. Pollock ◽  
Clare V. L. Oates ◽  
Cristina Giogha ◽  
Tania Wong Fok Lung ◽  
Sze Ying Ong ◽  
...  

ABSTRACT During infection, enteropathogenic Escherichia coli (EPEC) translocates effector proteins directly into the cytosol of infected enterocytes using a type III secretion system (T3SS). Once inside the host cell, these effector proteins subvert various immune signaling pathways, including death receptor-induced apoptosis. One such effector protein is the non-locus of enterocyte effacement (LEE)-encoded effector NleB1, which inhibits extrinsic apoptotic signaling via the FAS death receptor. NleB1 transfers a single N-acetylglucosamine (GlcNAc) residue to Arg117 in the death domain of Fas-associated protein with death domain (FADD) and inhibits FAS ligand (FasL)-stimulated caspase-8 cleavage. Another effector secreted by the T3SS is NleF. Previous studies have shown that NleF binds to and inhibits the activity of caspase-4, -8, and -9 in vitro. Here, we investigated a role for NleF in the inhibition of FAS signaling and apoptosis during EPEC infection. We show that NleF prevents the cleavage of caspase-8, caspase-3, and receptor-interacting serine/threonine protein kinase 1 (RIPK1) in response to FasL stimulation. When translocated into host cells by the T3SS or expressed ectopically, NleF also blocked FasL-induced cell death. Using the EPEC-like mouse pathogen Citrobacter rodentium, we found that NleB but not NleF contributed to colonization of mice in the intestine. Hence, despite their shared ability to block FasL/FAS signaling, NleB and NleF have distinct roles during infection.


2013 ◽  
Vol 790 ◽  
pp. 607-610 ◽  
Author(s):  
Yu Bin Ji ◽  
Dong Xue Song ◽  
Chen Feng Ji

The purpose of this study is to investigate the effect of fucosterol on the induction of apoptosis and the molecular mechanism involved in Human promyelocytic leukemia HL-60 Cells. HL-60 Cells were treated with different concentrations of fucosterol at different time. MTT method was used to study fucosterol anti-tumor activity. Morphology observation was performed to determine the effects of fucosterol on apoptosis of HL-60 cells. Flow cytometry (FCM) was used to detect the cell cycle. Laser scanning confocal microscope (LSCM) was used to analyze the expressions of Fas, FasL, Fadd and Caspase-8. Caspase activity kits were used to determine the activity of Caspase-8 and Caspase-3. The results showed fucosterol could inhibit the growth of HL-60 cells, and the apoptosis morphology for 48 h treatment was obvious, which showed cell protuberance, cytoplasm concentrated and apoptotic body. Fucosterol treatment for 24 h increased the protein expression of Fas, FasL, Fadd and Caspase-8. It also showed that the activity of Caspase-3 and Caspase-8 has increased significantly. In conclusion, Fucosterol could induce HL-60 cells apoptosis via death receptor pathway.


2009 ◽  
Vol 296 (5) ◽  
pp. G1060-G1068 ◽  
Author(s):  
Do Y. Lim ◽  
Jung Han Yoon Park

Fisetin, or 3,3′,4′,7-tetrahydroxyflavone, is present in fruits and vegetables and has been previously reported to inhibit the proliferation of a variety of cancer cells (Lu X, Jung J, Cho HJ, Lim do Y, Lee HS, Chun HS, Kwon DY, Park JH. J Nutr 135: 2884–2890, 2005). We have demonstrated in a previous work that 20–60 μmol/l fisetin inhibits cyclin-dependent kinase activities resulting in cell cycle arrest in HT-29 colon cancer cells. In the present study, we attempted to characterize the mechanisms by which fisetin induces apoptosis in HCT-116 cells. DNA condensations, cleavage of poly(ADP-ribose) polymerase (PARP), and cleavage of caspases 9, 7, and 3 were induced in HCT-116 cells treated with 5–20 μmol/l of fisetin. Fisetin induced a reduction in the protein levels of antiapoptotic Bcl-xL and Bcl-2 and an increase in the levels of proapoptotic Bak and Bim. Fisetin did not affect the Bax protein levels, but induced the mitochondrial translocation of this protein. Fisetin also enhanced the permeability of the mitochondrial membrane and induced the release of cytochrome c and Smac/Diablo. Additionally, fisetin caused an increase in the protein levels of cleaved caspase-8, Fas ligand, death receptor 5, and TNF-related apoptosis-inducing ligand, and the caspase-8 inhibitor Z-IETD-FMK suppressed fisetin-induced apoptosis and the activation of caspase-3. Furthermore, fisetin increases p53 protein levels, and the inhibition of p53 expression by small interference RNA resulted in a decrease in the fisetin-induced translocation of Bax to the mitochondria, release of mono- and oligonucleosome in the cytoplasm, and PARP cleavage. These results show that fisetin induces apoptosis in HCT-116 cells via the activation of the death receptor- and mitochondrial-dependent pathway and subsequent activation of the caspase cascade. The induction of p53 results in the translocation of Bax to the mitochondria, which contributes to fisetin-induced apoptosis in HCT-116 cells.


Blood ◽  
1999 ◽  
Vol 93 (10) ◽  
pp. 3309-3316 ◽  
Author(s):  
Chunhua Dai ◽  
Sanford B. Krantz

Interferon γ (IFNγ) induces apoptosis in purified human erythroid colony-forming cells (ECFC) and inhibits cell growth. Fas (APO-1; CD95) and Fas ligand (FasL) mediate apoptosis induced by IFNγ, because Fas is significantly upregulated by IFNγ, whereas Fas ligand is constitutively present in the ECFC and neutralization of FasL greatly reduces the apoptosis. Because conversion of caspases from their dormant proenzyme forms to active enzymes has a critical role in transducing a cascade leading to apoptosis, we performed further studies of the expression and activation of caspases in normal human and IFNγ-treated day-6 ECFC to better understand the mechanism of IFNγ action in producing this cell death. RNase protection assays showed that the caspase-1, -2, -6, -8, and -9 mRNAs were upregulated by IFNγ, whereas the caspase-5 and -7 mRNAs were not increased. Western blots showed that FLICE/caspase-8 was upregulated and activated by 24 hours of incubation with IFNγ. FADD was not similarly altered by incubation with IFNγ. Western blots of ICE/caspase-1, which might be required for amplification of the initial FLICE activation signal, showed that pro-ICE expression significantly increased after treatment with IFNγ for 24 hours and cleavage of pro-ICE also increased. CPP32/apopain/caspase-3, responsible for the proteolytic cleavage of poly (ADP) ribose polymerase (PARP), was also studied and treatment of ECFC with IFNγ resulted in an increased concentration of caspase-3 by 24 hours and a clear induction of enzyme activation by 48 hours, which was identified by the appearance of its p17-kD peptide fragment. The cleavage of PARP was demonstrated by an obvious increase of the 89-kD PARP cleavage product, which was observed at almost the same time as caspase-3 activation in the IFNγ-treated cells, whereas untreated ECFC showed little change. Peptide inhibitors of the caspase proteins, DEVD-fmk, DEVD-cho, YVAD-cho, and IETD-fmk, were incubated with the ECFC to obtain further evidence for the involvement of caspases in IFNγ-induced apoptosis. The activation of FLICE/caspase-8 and CPP32/caspase-3 and cleavage of PARP clearly were inhibited, but the reduction of cell growth due to apoptosis, induced by IFNγ, was only partially blocked by the presence of the inhibitors. These results indicate that IFNγ acts on ECFC not only to upregulate Fas, but also to selectively upregulate caspases-1, -3, and -8, which are activated and produce apoptosis, whereas the concentrations of FasL and FADD are not demonstrably changed.


PLoS ONE ◽  
2013 ◽  
Vol 8 (8) ◽  
pp. e71553 ◽  
Author(s):  
Xiaodong Huang ◽  
Zhaohui Lu ◽  
Zhongwei Lv ◽  
Tingting Yu ◽  
Peirong Yang ◽  
...  

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2050-2050
Author(s):  
Patricia Disperati ◽  
Fernando Suarez-Saiz ◽  
Marcela Gronda ◽  
Mark D. Minden ◽  
Aaron Schimmer

Abstract Gene silencing through hypermethylation is common in cancer cells and may contribute to chemoresistance and poor patient outcomes. To investigate this mechanism in leukemia, OCI-AML2 leukemia cells were screened for methylated genes. Among the genes identified using Cpg arrays was caspase-8. Levels of mRNA and protein of caspase-8 were decreased in OCI-AML2 cells compared to control cell lines (Jurkat cells). In contrast, levels of FLIP, caspase-3 and XIAP did not differ between both cell lines. As further evidence of caspase-8 hypermethylation, treatment of OCI-AML2 cells with the demethylating agent 5-Aza-2′-Deoxycytidine (AzaD) increased expression of caspase-8 protein to levels similar to Jurkat cells. To determine whether the silencing of caspase-8 occurs in primary patient samples, levels of caspase-8 were measured by immunoblots in 16 samples from patients with AML. Compared to normal peripheral blood mononuclear stem cells, caspase-8 was reduced in five of 16 (31%) samples. To determine whether the low caspase 8 was a functional consequence, OCI-AML2 cells were treated with CH-11 anti-FAS antibody (100 ng/mL) for 24 hours. Despite the cells expressing the FAS receptor on the surface, less than 5% of apoptosis occurred. In contrast, an equal concentration of CH-11 induced 80% apoptosis in Jurkat cells. To test the status of the death receptor pathway downstream of caspase-8, cytosolic lysates from OCI-AML2 cells were stimulated with recombinant active caspase-8 to directly activate effector caspases. Stimulation of OCI-AML2 lysates with recombinant active caspase-8 increased the maximal rate of effector caspase hydrolysis of Ac-DEVD-AFC 8 fold above buffer treated control, comparable to treatment of Jurkat lysates. These results indicate that OCI-AML2 cells have defects above the level of the effector casapses that renders them resistant to death receptor ligands. To determine if silencing of casp-8 is sufficient to explain these defects, OCI-AML2 cells were cultured with AzaD and CH-11 anti-FAS antibody. Despite restoration of caspase-8 protein levels, AzaD did not restore sensitivity to CH-11. Likewise, transfection of caspase-8 into OCI-AML2 did not restore sensitivity. Therefore, casp-8 is silenced in OCI-AML2 cells and primary patient samples. However, the events indicate the presence of additional defects in the death receptor pathway that cannot be reversed by demethylation. These results suggest that blockade of apoptosis throughout the death receptor pathway may occur at several points and that in some cases, simple reversal of demethylation may not be sufficient.


2011 ◽  
Vol 301 (5) ◽  
pp. H2028-H2037 ◽  
Author(s):  
Wei-Qing Han ◽  
Min Xia ◽  
Chun Zhang ◽  
Fan Zhang ◽  
Ming Xu ◽  
...  

The present study attempted to evaluate whether soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) mediate lysosome fusion in response to death receptor activation and contribute to membrane raft (MR) clustering and consequent endothelial dysfunction in coronary arterial endothelial cells. By immunohistochemical analysis, vesicle-associated membrane proteins 2 (VAMP-2, vesicle-SNAREs) were found to be abundantly expressed in the endothelium of bovine coronary arteries. Direct lysosome fusion monitoring by N-(3-triethylammoniumpropyl)-4-[4-(dibutylamino)styryl]pyridinium dibromide (FM1-43) quenching demonstrated that the inhibition of VAMP-2 with tetanus toxin or specific small interfering ribonucleic acid (siRNA) almost completely blocked lysosome fusion to plasma membrane induced by Fas ligand (FasL), a well-known MR clustering stimulator. The involvement of SNAREs was further confirmed by an increased interaction of VAMP-2 with a target-SNARE protein syntaxin-4 after FasL stimulation in coimmunoprecipitation analysis. Also, the inhibition of VAMP-2 with tetanus toxin or VAMP-2 siRNA abolished FasL-induced MR clustering, its colocalization with a NADPH oxidase unit gp91 phox, and increased superoxide production. Finally, FasL-induced impairment of endothelium-dependent vasodilation was reversed by the treatment of bovine coronary arteries with tetanus toxin or VAMP-2 siRNA. VAMP-2 is critical to lysosome fusion in MR clustering, and this VAMP-2-mediated lysosome-MR signalosomes contribute to redox regulation of coronary endothelial function.


2020 ◽  
Vol 16 (4) ◽  
pp. 595-601
Author(s):  
Nguyen Thi Xuan ◽  
Le Thi Thu Hien

Vitamin C (VitC) is a potent antioxidant and contributes as an apoptosis inhibitor by preventing death receptor-triggered caspase 8 activity. Fas ligand (FasL) induces the apoptotic cell death via activation of Fas signaling, which is dependent on the expression level of anti-apoptotic molecule c-FLIP (FADD-like IL-1beta-converting enzyme-inhibitory proteins). The present study addressed the effects of VitC on survival of dendritic cells (DCs), a regulator of innate and adaptive immunity. To this end, mouse bone marrow cells were isolated and cultured to attain bone marrow-derived DCs (BMDCs). The cells were treated with FasL in the presence or absence of VitC. Real time RT-PCR, Western blotting and FACS analysis were performed to determine different hallmarks of DC apoptosis. As a result, FasL treatment resulted in activation of caspase 8 and stimulation of cell membrane scrambling, the effects were supressed when VitC was present in the cell culture or the cells were transfected with FLIP siRNA. In conclusion, VitC prevented FasL-triggered DC apoptosis mediated through the expression of c-FLIP.


Sign in / Sign up

Export Citation Format

Share Document