scholarly journals Conserved Cysteine-Rich Domain of Paramyxovirus Simian Virus 5 V Protein Plays an Important Role in Blocking Apoptosis

2004 ◽  
Vol 78 (10) ◽  
pp. 5068-5078 ◽  
Author(s):  
Minghao Sun ◽  
Terri A. Rothermel ◽  
Laurie Shuman ◽  
Jason A. Aligo ◽  
Shibo Xu ◽  
...  
Keyword(s):  
Er Stress ◽  
Simian Virus ◽  
Hendra Virus ◽  
Dependent Manner ◽  
Emerging Viruses ◽  
V Protein ◽  
Simian Virus 5 ◽  
Caspase 12 ◽  
Animal Pathogens ◽  
Induced Apoptosis

ABSTRACT The paramyxovirus family includes many well-known human and animal pathogens as well as emerging viruses such as Hendra virus and Nipah virus. The V protein of simian virus 5 (SV5), a prototype of the paramyxoviruses, contains a cysteine-rich C-terminal domain which is conserved among all paramyxovirus V proteins. The V protein can block both interferon (IFN) signaling by causing degradation of STAT1 and IFN production by blocking IRF-3 nuclear import. Previously, it was reported that recombinant SV5 lacking the C terminus of the V protein (rSV5VΔC) induces a severe cytopathic effect (CPE) in tissue culture whereas wild-type (wt) SV5 infection does not induce CPE. In this study, the nature of the CPE and the mechanism of the induction of CPE were investigated. Through the use of DNA fragmentation, terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling, and propidium iodide staining assays, it was shown that rSV5VΔC induced apoptosis. Expression of wt V protein prevented apoptosis induced by rSV5VΔC, suggesting that the V protein has an antiapoptotic function. Interestingly, rSV5VΔC induced apoptosis in U3A cells (a STAT1-deficient cell line) and in the presence of neutralizing antibody against IFN, suggesting that the induction of apoptosis by rSV5VΔC was independent of IFN and IFN-signaling pathways. Apoptosis induced by rSV5VΔC was blocked by a general caspase inhibitor, Z-VAD-FMK, but not by specific inhibitors against caspases 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 13, suggesting that rSV5VΔC-induced apoptosis can occur in a caspase 12-dependent manner. Endoplasmic reticulum stress can lead to activation of caspase 12; compared to the results seen with mock and wt SV5 infection, rSV5VΔC infection induced ER stress, as demonstrated by increased expression levels of known ER stress indicators GRP 78, GRP 94, and GADD153. These data suggest that rSV5VΔC can trigger cell death by inducing ER stress.

scholarly journals Induction of Apoptosis by Paramyxovirus Simian Virus 5 Lacking a Small Hydrophobic Gene

2003 ◽  
Vol 77 (6) ◽  
pp. 3371-3383 ◽  
Author(s):  
Yuan Lin ◽  
Angela C. Bright ◽  
Terri A. Rothermel ◽  
Biao He
Keyword(s):  
Neutralizing Antibodies ◽  
Culture Media ◽  
Simian Virus ◽  
Hendra Virus ◽  
Dependent Manner ◽  
Simian Virus 5 ◽  
Tnf Α ◽  
Animal Pathogens ◽  
Infected Cells ◽  
Small Hydrophobic

ABSTRACT Simian virus 5 (SV5) is a member of the paramyxovirus family, which includes emerging viruses such as Hendra virus and Nipah virus as well as many important human and animal pathogens that have been known for years. SV5 encodes eight known viral proteins, including a small hydrophobic integral membrane protein (SH) of 44 amino acids. SV5 without the SH gene (rSV5ΔSH) is viable, and growth of rSV5ΔSH in tissue culture cells and viral protein and mRNA production in rSV5ΔSH-infected cells are indistinguishable from those of the wild-type SV5 virus. However, rSV5ΔSH causes increased cytopathic effect (CPE) and apoptosis in MDBK cells and is attenuated in vivo, suggesting the SH protein plays an important role in SV5 pathogenesis. How rSV5ΔSH induces apoptosis in infected cells has been examined in this report. Tumor necrosis factor alpha (TNF-α), a proinflammatory cytokine, was detected in culture media of rSV5ΔSH-infected cells. Apoptosis induced by rSV5ΔSH was inhibited by neutralizing antibodies against TNF-α and TNF-α receptor 1 (TNF-R1), suggesting that TNF-α played an essential role in rSV5ΔSH-induced apoptosis in a TNF-R1-dependent manner. Examination of important proteins in the TNF-α signaling pathway showed that p65, a major NF-κB subunit whose activation can lead to transcription of TNF-α, was first translocated to the nucleus and was capable of binding to DNA and then was targeted for degradation in rSV5ΔSH-infected cells while expression levels of TNF-R1 remained relatively constant. Thus, rSV5ΔSH induced cell death by activating TNF-α expression, possibly through activation of the NF-κB subunit p65 and then targeting p65 for degradation, leading to apoptosis.

scholarly journals Virus Replication in Engineered Human Cells That Do Not Respond to Interferons

2003 ◽  
Vol 77 (3) ◽  
pp. 2174-2181 ◽  
Author(s):  
D. F. Young ◽  
L. Andrejeva ◽  
A. Livingstone ◽  
S. Goodbourn ◽  
R. A. Lamb ◽  
...  
Keyword(s):  
Virus Replication ◽  
Vaccine Development ◽  
Simian Virus ◽  
Cell Tropism ◽  
Emerging Viruses ◽  
V Protein ◽  
Practical Applications ◽  
Simian Virus 5 ◽  
Virus Diagnostics ◽  
Slow Growing

ABSTRACT The V protein of the paramyxovirus simian virus 5 blocks interferon (IFN) signaling by targeting STAT1 for proteasome-mediated degradation. Here we report on the isolation of human cell lines that express the V protein and can no longer respond to IFN. A variety of viruses, particularly slow-growing wild-type viruses and vaccine candidate viruses (which are attenuated due to mutations that affect virus replication, virus spread, or ability to circumvent the IFN response), form bigger plaques and grow to titers that are increased as much as 10- to 4,000-fold in these IFN-nonresponsive cells. We discuss the practical applications of using such cells in vaccine development and manufacture, virus diagnostics and isolation of newly emerging viruses, and studies on host cell tropism and pathogenesis.

scholarly journals Hepatitis B Virus X Protein and Simian Virus 5 V Protein Exhibit Similar UV-DDB1 Binding Properties To Mediate Distinct Activities

2003 ◽  
Vol 77 (11) ◽  
pp. 6274-6283 ◽  
Author(s):  
Olivier Leupin ◽  
Séverine Bontron ◽  
Michel Strubin
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Simian Virus ◽  
Binding Activity ◽  
X Protein ◽  
Binding Properties ◽  
V Protein ◽  
Dna Binding Activity ◽  
Simian Virus 5 ◽  
B Virus

ABSTRACT The UV-damaged DNA-binding activity protein (UV-DDB) consists of two subunits, DDB1 and DDB2, and functions in DNA repair and cell cycle regulation. The DDB1 subunit is a target for the hepatitis B virus X protein (HBx). Binding of HBx to DDB1 interferes with cell growth and viability in culture and has been implicated in the establishment of viral infection. DDB1 also interacts with the V proteins encoded by several paramyxoviruses including simian virus 5 (SV5), which prevent interferon signaling by targeting either STAT1 or STAT2 proteins for proteolysis. The role of V binding to DDB1, however, remains unclear. Here we show that the V protein of SV5 (SV5-V) and HBx exhibit strikingly similar DDB1 binding properties. Thus, SV5-V and HBx bind to DDB1 in a mutually exclusive manner, and SV5-V shares with HBx the ability to enhance the steady-state levels of DDB1 and to inhibit its association with DDB2. Yet only HBx induces cell death, and SV5-V can prevent HBx from doing so by blocking its interaction with DDB1. Binding of SV5-V to DDB1 may serve another function, since SV5-V shows a decreased ability to induce STAT1 degradation in cells expressing reduced amounts of DDB1. These findings demonstrate that HBx performs a unique function through its association with DDB1 for which SV5-V cannot substitute and suggest that SV5-V and HBx have evolved to bind DDB1 to achieve distinct functions, both by a mechanism that does not involve DDB2.

scholarly journals The Paramyxovirus Simian Virus 5 V Protein Slows Progression of the Cell Cycle

2000 ◽  
Vol 74 (19) ◽  
pp. 9152-9166 ◽  
Author(s):  
Grace Y. Lin ◽  
Robert A. Lamb
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Simian Virus ◽  
S Phase ◽  
V Protein ◽  
Simian Virus 5 ◽  
C Terminus ◽  
M Phase ◽  
Infected Cells ◽  
Affect Cell Cycle Progression

ABSTRACT Infection of cells by many viruses affects the cell division cycle of the host cell to favor viral replication. We examined the ability of the paramyxovirus simian parainfluenza virus 5 (SV5) to affect cell cycle progression, and we found that SV5 slows the rate of proliferation of HeLa T4 cells. The SV5-infected cells had a delayed transition from G1 to S phase and prolonged progression through S phase, and some of the infected cells were arrested in G2 or M phase. The levels of p53 and p21CIP1were not increased in SV5-infected cells compared to mock-infected cells, suggesting that the changes in the cell cycle occur through a p53-independent mechanism. However, the phosphorylation of the retinoblastoma protein (pRB) was delayed and prolonged in SV5-infected cells. The changes in the cell cycle were also observed in cells expressing the SV5 V protein but not in the cells expressing the SV5 P protein or the V protein lacking its unique C terminus (VΔC). The unique C terminus of the V protein of SV5 was shown previously to interact with DDB1, which is the 127-kDa subunit of the multifunctional damage-specific DNA-binding protein (DDB) heterodimer. The coexpression of DDB1 with V can partially restore the changes in the cell cycle caused by expression of the V protein.

Autophagy triggers endoplasmic reticulum stress and C/EBP homologous protein-mediated apoptosis in OGD/R-treated neurons in a caspase-12-independent manner

2021 ◽  
Author(s):  
Ying Tian ◽  
Liang Wang ◽  
Zhiqiang Qiu ◽  
Yulun Xu ◽  
Rongrong Hua
Keyword(s):  
Endoplasmic Reticulum ◽  
Cortical Neurons ◽  
Neuronal Apoptosis ◽  
Glucose Deprivation ◽  
Oxygen Glucose Deprivation ◽  
Caspase 8 ◽  
Dependent Manner ◽  
Homologous Protein ◽  
Caspase 12 ◽  
Induced Apoptosis

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.

scholarly journals MiR-657/ATF2 Signaling Pathway Has a Critical Role in Spatholobus suberectus Dunn Extract-Induced Apoptosis in U266 and U937 Cells

Cancers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 150 ◽  
Author(s):  
Hyun Lim ◽  
Moon Park ◽  
Changmin Kim ◽  
Beomku Kang ◽  
Hyo-Sook Song ◽  
...  
Keyword(s):  
Er Stress ◽  
Critical Role ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Parp Cleavage ◽  
Dependent Manner ◽  
U937 Cells ◽  
Anti Cancer ◽  
Spatholobus Suberectus ◽  
Induced Apoptosis ◽  
Related Proteins

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.

scholarly journals Dihydrochalcone Derivative Induces Breast Cancer Cell Apoptosis via Intrinsic, Extrinsic, and ER Stress Pathways but Abolishes EGFR/MAPK Pathway

2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Wasitta Rachakhom ◽  
Patompong Khaw-on ◽  
Wilart Pompimon ◽  
Ratana Banjerdpongchai
Keyword(s):  
Breast Cancer ◽  
Er Stress ◽  
Cell Lines ◽  
Cell Apoptosis ◽  
Mapk Pathway ◽  
Annexin V ◽  
Mapk Signaling ◽  
Dependent Manner ◽  
Induced Apoptosis ◽  
Mcf 7

Dihydrochalcone derivatives are active compounds that have been purified from the Thai medicinal plant Cyathostemma argenteum. The objectives of this study were to investigate the effects of two dihydrochalcone derivatives on human breast cancer MDA-MB-231 and MCF-7 cell proliferation and to study the relevant mechanisms involved. The two dihydrochalcone derivatives are 4′,6′-dihydroxy-2′,4-dimethoxy-5′-(2″-hydroxybenzyl)dihydrochalcone (compound 1) and calomelanone (2′,6′-dihydroxy-4,4′-dimethoxydihydrochalcone, compound 2), both of which induced cytotoxicity toward both cell lines in a dose-dependent manner by using MTT assay. Treatment with both derivatives induced apoptosis as determined by annexin V-FITC/propidium iodide employing flow cytometry. The reduction of mitochondrial transmembrane potential (staining with 3,3′-dihexyloxacarbocyanine iodide, DiOC6, employing a flow cytometer) was established in the compound 1-treated cells. Compound 1 induced caspase-3, caspase-8, and caspase-9 activities in both cell lines, as has been determined by specific colorimetric substrates and a spectrophotometric microplate reader which indicated the involvement of both the extrinsic and intrinsic pathways. Calcium ion levels in mitochondrial and cytosolic compartments increased in compound 1-treated cells as detected by Rhod-2AM and Fluo-3AM intensity, respectively, indicating the involvement of the endoplasmic reticulum (ER) stress pathway. Compound 1 induced cell cycle arrest via enhanced atm and atr expressions and by upregulating proapoptotic proteins, namely, Bim, Bad, and tBid. Moreover, compound 1 significantly inhibited the EGFR/MAPK signaling pathway. In conclusion, compound 1 induced MDA-MB-231 and MCF-7 cell apoptosis via intrinsic, extrinsic, and ER stress pathways, whereas it ameliorated the EGFR/MAPK pathway in the MCF-7 cell line. Consequently, it is believed that compound 1 could be effectively developed for cancer treatments.

scholarly journals N6-(2-hydroxyethyl)-Adenosine Induces Apoptosis via ER Stress and Autophagy of Gastric Carcinoma Cells In Vitro and In Vivo

2020 ◽  
Vol 21 (16) ◽  
pp. 5815
Author(s):  
Hongqing Xie ◽  
Xiaotong Li ◽  
Weiwei Yang ◽  
Liping Yu ◽  
Xiasen Jiang ◽  
...  
Keyword(s):  
Gastric Carcinoma ◽  
Er Stress ◽  
Carcinoma Cells ◽  
Dependent Manner ◽  
Antineoplastic Effect ◽  
Tumor Tissues ◽  
Induced Apoptosis ◽  
Species Production

Gastric cancer is the most common malignant tumor of the digestive tract and is great challenge in clinical treatment. N6-(2-Hydroxyethyl)-adenosine (HEA), widely present in various fungi, is a natural adenosine derivative with many biological and pharmacological activities. Here, we assessed the antineoplastic effect of HEA on gastric carcinoma. HEA exerted cytotoxic effects against gastric carcinoma cells (SGC-7901 and AGS) in a dose and time-dependent manner. Additionally, we found that HEA induced reactive oxygen species production and mitochondrial membrane potential depolarization. Moreover, it could trigger caspase-dependent apoptosis, promoting intracellular Ca2+-related endoplasmic reticulum (ER) stress and autophagy. On the other hand, HEA could significantly inhibit the growth of transplanted tumors in nude mice and induce apoptosis of tumor tissues cells in vivo. In conclusion, HEA induced apoptosis of gastric carcinoma cells in vitro and in vivo, demonstrating that HEA is a potential chemotherapeutic agent for gastric carcinoma.

Effects of Stearic Acid on Proliferation, Differentiation, Apoptosis, and Autophagy in Porcine Intestinal Epithelial Cells

2020 ◽  
Vol 20 (2) ◽  
pp. 157-166
Author(s):  
Yuan Yang ◽  
Jin Huang ◽  
Jianzhong Li ◽  
Huansheng Yang ◽  
Yulong Yin
Keyword(s):  
Cell Differentiation ◽  
Epithelial Cells ◽  
Stearic Acid ◽  
Er Stress ◽  
Intestinal Epithelial Cells ◽  
Dependent Manner ◽  
Intestinal Epithelial ◽  
High Concentrations ◽  
Induced Apoptosis ◽  
Dose Dependent

Background: Stearic acid (SA), a saturated long-chain fatty acid consisting of 18 carbon atoms, is widely found in feed ingredients, such as corn, soybeans, and wheat. However, the roles of SA in the renewal of intestinal epithelial cells remain unclear. Methods and Results: In the present study, we found that 0.01-0.1 mM SA promoted IPEC-J2 cell differentiation and did not affect IPEC-J2 cell viability. In addition, the results showed that the viability of IPEC-J2 cells was inhibited by SA in a time- and dose-dependent manner at high concentrations. Flow cytometry and western blot analysis suggested that SA induced apoptosis, autophagy and ER stress in cells. In addition, the amounts of triglyceride were significantly increased upon challenge with SA. Moreover, the decrease in the viability of cells induced by SA could be attenuated by 4-PBA, an inhibitor of ER stress. Conclusion: In summary, SA accelerated IPEC-J2 cell differentiation at 0.01-0.1 mM. Furthermore, SA induced IPEC-J2 cell apoptosis and autophagy by causing ER stress.

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