scholarly journals Duck Plague Virus Promotes DEF Cell Apoptosis by Activating Caspases, Increasing Intracellular ROS Levels and Inducing Cell Cycle S-Phase Arrest

Viruses ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 196 ◽  
Author(s):  
Chuankuo Zhao ◽  
Mingshu Wang ◽  
Anchun Cheng ◽  
Qiao Yang ◽  
Ying Wu ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Viral Replication ◽  
Cell Cycle Progression ◽  
S Phase ◽  
Mrna Levels ◽  
Phase Arrest ◽  
Duck Plague Virus ◽  
Intracellular Ros ◽  
S Phase Arrest ◽  
Induced Apoptosis

Background: Duck plague virus (DPV) can induce apoptosis in duck embryo fibroblasts (DEFs) and in infected ducks, but the molecular mechanism of DPV-induced apoptosis remains unknown. Methods: We first used qRT-PCR and a Caspase-Glo assay to determine whether the caspase protein family plays an important role in DPV-induced apoptosis. Then, we used an intracellular ROS detection kit and the mitochondrial probe JC-1 to respectively detect ROS levels and mitochondrial membrane potential (MMP). Finally, flow cytometry was used to detect apoptosis and cell cycle progression. Results: In this study, the mRNA levels and enzymatic activities of caspase-3, caspase-7, caspase-8, and caspase-9 were significantly increased during DPV-induced apoptosis. The caspase inhibitors Z-DEVD-FMK, Z-LEHD-FMK, and Q-VD-OphA could inhibit DPV-induced apoptosis and promote viral replication. Subsequently, a significant decrease in MMP and an increase in the intracellular ROS levels were observed. Further study showed that pretreating infected cells with NAC (a ROS scavenger) decreased the intracellular ROS levels, increased the MMP, inhibited apoptosis, and promoted viral replication. Finally, we showed that DPV infection can cause cell cycle S-phase arrest. Conclusions: This study shows that DPV causes cell cycle S-phase arrest and leads to apoptosis through caspase activation and increased intracellular ROS levels. These findings may be useful for gaining an understanding of the pathogenesis of DPV and the apoptotic pathways induced by α-herpesviruses.

scholarly journals A Cds1-Mediated Checkpoint Protects the MBF Activator Rep2 from Ubiquitination by Anaphase-Promoting Complex/Cyclosome-Ste9 at S-Phase Arrest in Fission Yeast

2009 ◽  
Vol 29 (18) ◽  
pp. 4959-4970 ◽  
Author(s):  
Zhaoqing Chu ◽  
Majid Eshaghi ◽  
Suk Yean Poon ◽  
Jianhua Liu
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Transcriptional Activity ◽  
S Phase ◽  
Anaphase Promoting Complex ◽  
Cell Recovery ◽  
Cycle Progression ◽  
Phase Arrest ◽  
S Phase Arrest

ABSTRACT Transcription of the MluI cell cycle box (MCB) motif-containing genes at G1 phase is regulated by the MCB-binding factors (MBF) (also called DSC1) in Schizosaccharomyces pombe. Upon S-phase arrest, the MBF transcriptional activity is induced through the accumulation of the MBF activator Rep2. In this study, we show that the turnover of Rep2 is attributable to ubiquitin-mediated proteolysis. Levels of Rep2 oscillate during the cell cycle, with a peak at G1 phase, coincident with the MBF activity. Furthermore, we show that Rep2 ubiquitination requires the function of the E3 ligase anaphase-promoting complex/cyclosome (APC/C). Ste9 can be phosphorylated by the checkpoint kinase Cds1 in vitro, and its inhibition/phosphorylation at S-phase arrest is dependent on the function of Cds1. Our data indicate that the Cds1-dependent stabilization of Rep2 is achieved through the inhibition/phosphorylation of APC/C-Ste9 at the onset of S-phase arrest. Stabilization of Rep2 is important for stimulating transcription of the MBF-dependent genes to ensure a sufficient supply of proteins essential for cell recovery from S-phase arrest. We propose that oscillation of Rep2 plays a role in regulation of periodic transcription of the MBF-dependent genes during cell cycle progression.

scholarly journals Protein Kinase C δ Stimulates Apoptosis by Initiating G1Phase Cell Cycle Progression and S Phase Arrest

2005 ◽  
Vol 280 (37) ◽  
pp. 32107-32114 ◽  
Author(s):  
Ademi E. Santiago-Walker ◽  
Aphrothiti J. Fikaris ◽  
Gary D. Kao ◽  
Eric J. Brown ◽  
Marcelo G. Kazanietz ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Cell Cycle Progression ◽  
S Phase ◽  
Cycle Progression ◽  
Kinase C ◽  
Phase Arrest ◽  
S Phase Arrest

scholarly journals GADD45α regulates cell proliferation and DNA repair of BRL-3A cells that treated by FZD/UVC via P38, JNK, CDC2/CCNB1, AKT and MTOR pathways

2017 ◽  
Author(s):  
Xianguang Yang ◽  
Lin Zhu ◽  
Weiming Zhao ◽  
Chuncui He ◽  
Shuaihong Li ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Repair ◽  
Western Blot ◽  
Expression Profiles ◽  
S Phase ◽  
Qrt Pcr ◽  
Phase Arrest ◽  
S Phase Arrest ◽  
Induced Apoptosis ◽  
Number Of Cells

ABSTRACTGADD45α is a stress-induced gene activated by a variety of stress stimuli, including ultraviolet and ionizing radiation, and involved in cell cycle regulation, apoptosis, maintenance, genomic stability, DNA repair and immune response. However, the effects and regulatory mechanism of GADD45α on proliferation, apoptosis and DNA damage repair of hepatocytes in liver regeneration remains unclear. In this study overexpression of GADD45α significantly inhibited the cell viability, proliferation, the number of cells in G1 and S phases, and of furazolidone (FZD) or UVC induced apoptosis of BRL-3A cells and decreased the inhibition of FZD/UVC on the viability, proliferation of BRL-3A cells, while increased the number of cells in G2/M phase of BRL-3A cells and FZD/UVC induced S phase arrest. Downregulated GADD45α induced the viability, proliferation, the number of cells in S and G2/M phases and the inhibition of FZD/UVC on the viability, proliferation of BRL-3A cells increased, while decreased apoptosis, the number of cells in G1 phases of BRL-3A cells and FZD/UVC induced S phase arrest. The results of qRT-PCR and western blot showed that genes/proteins related to P38MAPK, JNK, CDC2/CCNB1, AKT and MTOR signaling pathways were significantly changed in normal BRL-3A cells. The expression profiles of cell cycle, proliferation and apoptosis related genes/proteins in FZD/UVC treated BRL-3A cells were also detected by qRT-PCR and western blot, and the results indicated that the expression of Myc, Bcl-2, Ccnd1, PCNA, P21, Ccnb1, Caspase3, Caspase8, Caspase9 and Bax have significantly changes.

Impaired S Phase Arrest in AML Cells with a FLT3-ITD Treated with Clofarabine Allows Prolonged Drug exposure to Reverse the Chemoresistant Phenotype.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1000-1000
Author(s):  
Claire Seedhouse ◽  
Martin Grundy ◽  
Shili Shang ◽  
John Ronan ◽  
Heather Pimblett ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Dna Repair ◽  
Cell Cycle Arrest ◽  
Short Pulse ◽  
S Phase ◽  
Mrna Levels ◽  
Cycle Arrest ◽  
Phase Arrest ◽  
S Phase Arrest

Abstract Abstract 1000 Poster Board I-22 We have previously reported that AML cells with a FLT3-ITD have enhanced DNA repair mechanisms following exposure to DNA-damaging drugs which may be a mechanism of chemoresistance. Clofarabine is a novel nucleoside analogue, active in S-phase, with efficacy in AML and is incorporated into DNA as clofarabine triphosphate. Here we show that in FLT3-ITD cells enhanced repair, and therefore resistance to clofarabine-induced DNA damage and toxicity, can be reversed by prolonged drug incubation. When treated with clofarabine, FLT3-ITD-harbouring MOLM13 and MV4.11 cells undergo similar levels of DNA damage (γH2A.X foci) to FLT3 wildtype (WT) cells (HL60 and KG1). After a short pulse of drug the FLT3-ITD cells have a superior repair capability than WT cells; following a 2 hour washout period γH2A.X positivity found immediately after treatment had almost completely disappeared in the FLT3-ITD cells (<10% γH2A.X remaining), whereas in the FLT3-WT cells significant damage (γH2A.X) remained (>40%). Furthermore, after a 1 hour pulse of clofarabine, whereas the FLT3-WT cells under go rapid S phase arrest the S-phase checkpoint fails in the FLT3-ITD cells: reduction in the proportion of cells synthesising DNA is >80% in FLT3-WT cells and <10% in FLT3-ITD cells. Cell cycle arrest in response to DNA damage in S phase is affected via loss of the transcriptional regulator cdc25A. This loss of expression of cdc25A fails to take place in clofarabine-treated FLT3 mutant cells compared to WT cells. In addition, cdc25A mRNA levels are maintained by the FLT3-ITD as demonstrated by siRNA to FLT3 which reduced cdc25A mRNA levels in MV4.11 cells by 87.5%. Primary FLT3 mutant samples from AML patients(n=3) also display impaired cell cycle arrest upon treatment with clofarabine and show enhanced sensitivity on prolonged treatment (24 hours) compared to wildtype samples (n=2). We conclude that there is a reversal of phenotype in mutant FLT3 cells dependant on the length of exposure to clofarabine. Efficient DNA repair renders the cells resistant to a short pulse of the drug, but a failure of cell cycle checkpoint(s) in S phase, mediated by cdc25A, renders the cells sensitive to prolonged exposure. These results may have implications for the scheduling of clofarabine in clinical studies. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Coronavirus PEDV nucleocapsid protein interacts with p53 to induce cell cycle arrest in S-phase and promotes viral replication

2021 ◽  
Author(s):  
Mingjun Su ◽  
Da Shi ◽  
Xiaoxu Xing ◽  
Shanshan Qi ◽  
Dan Yang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Viral Replication ◽  
Cell Cycle Arrest ◽  
Host Cell ◽  
S Phase ◽  
N Protein ◽  
Diarrhea Virus ◽  
Cycle Arrest ◽  
Phase Arrest ◽  
S Phase Arrest

Subversion of the host cell cycle to facilitate viral replication is a common feature of coronavirus infections. Coronavirus nucleocapsid (N) protein could modulate host cell cycle, but the mechanistic details remain largely unknown. Here, we investigated manipulation of porcine epidemic diarrhea virus (PEDV) N protein on cell cycle and its influence on viral replication. Results indicated that PEDV N-induced Vero E6 cell cycle arrest at S-phase, which promoted viral replication ( P < 0.05). S-phase arrest was dependent on N protein nuclear localization signal S 71 NWHFYYLGTGPHADLRYRT 90 and interaction between N protein and p53. In the nucleus, the binding of N protein to p53 maintained consistently high-level expression of p53, which activated p53-DREAM pathway. The key domain of the N protein interacting with p53 was revealed to be S 171 RGNSQNRGNNQGRGASQNRGGNN 194 (N S171-N194 ), in which G 183 RG 185 are core sites. N S171-N194 and G 183 RG 185 were essential for N-induced S-phase arrest. Moreover, small molecular drugs targeting the N S171-N194 domain of PEDV N protein were screened through molecular docking. Hyperoside could antagonize N protein-induced S-phase arrest by interfering with interaction between N protein and p53 and inhibit viral replication ( P < 0.05). The above experiments were also validated in porcine intestinal cells, and resulting data were in line with that of Vero E6 cells. Therefore, these results revealed that PEDV N protein interacted with p53 to activate p53-DREAM pathway, and subsequently induced S-phase arrest to create a favorable environment for virus replication. These findings provided new insight into the PEDV-host interaction and the design of novel antiviral strategies against PEDV.

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

2014 ◽  
Vol 278 (3) ◽  
pp. 249-258 ◽  
Author(s):  
Jong-Shian Liou ◽  
Yi-Chen Wu ◽  
Wen-Yen Yen ◽  
Yu-Shuan Tang ◽  
Rajesh B. Kakadiya ◽  
...  
Keyword(s):  
Dna Damage ◽  
S Phase ◽  
Phase Arrest ◽  
S Phase Arrest ◽  
Induced Apoptosis

Antimycin A as a mitochondria damage agent induces an S phase arrest of the cell cycle in HeLa cells

Life Sciences ◽  
2008 ◽  
Vol 83 (9-10) ◽  
pp. 346-355 ◽  
Author(s):  
Yong Hwan Han ◽  
Suhn Hee Kim ◽  
Sung Zoo Kim ◽  
Woo Hyun Park
Keyword(s):  
Cell Cycle ◽  
Hela Cells ◽  
S Phase ◽  
Antimycin A ◽  
Phase Arrest ◽  
S Phase Arrest

scholarly journals Inhibition of tumor cell growth by adenine is mediated by apoptosis induction and cell cycle S phase arrest

Oncotarget ◽  
2017 ◽  
Vol 8 (55) ◽  
pp. 94286-94296 ◽  
Author(s):  
Ming Han ◽  
Xin Cheng ◽  
Zhiqin Gao ◽  
Rongrong Zhao ◽  
Shizhuang Zhang
Keyword(s):  
Cell Cycle ◽  
Cell Growth ◽  
Tumor Cell ◽  
S Phase ◽  
Tumor Cell Growth ◽  
Apoptosis Induction ◽  
Phase Arrest ◽  
S Phase Arrest

scholarly journals p21Cip1 and p27Kip1Regulate Cell Cycle Reentry after Hypoxic Stress but Are Not Necessary for Hypoxia-Induced Arrest

2001 ◽  
Vol 21 (4) ◽  
pp. 1196-1206 ◽  
Author(s):  
Susannah L. Green ◽  
Rachel A. Freiberg ◽  
Amato J. Giaccia
Keyword(s):  
Cell Cycle ◽  
Dna Synthesis ◽  
Kinase Inhibitors ◽  
S Phase ◽  
Hypoxic Stress ◽  
Cyclin Dependent Kinase ◽  
Low Oxygen ◽  
Double Knockout ◽  
Phase Arrest ◽  
S Phase Arrest

ABSTRACT We investigated the role of the cyclin-dependent kinase inhibitors p21Cip1 and p27Kip1 in cell cycle regulation during hypoxia and reoxygenation. While moderate hypoxia (1 or 0.1% oxygen) does not significantly impair bromodeoxyuridine incorporation, at very low oxygen tensions (0.01% oxygen) DNA replication is rapidly shut down in immortalized mouse embryo fibroblasts. This S-phase arrest is intact in fibroblasts lacking the cyclin kinase inhibitors p21Cip1 and p27Kip1, indicating that these molecules are not essential elements of the arrest pathway. Hypoxia-induced arrest is accompanied by dephosphorylation of pRb and inhibition of cyclin-dependent kinase 2, which results in part from inhibitory phosphorylation. Interestingly, cells lacking the retinoblastoma tumor suppressor protein also display arrest under hypoxia, suggesting that pRb is not an essential mediator of this response. Upon reoxygenation, DNA synthesis resumes by 3.5 h and reaches aerobic levels by 6 h. Cells lacking p21, however, resume DNA synthesis more rapidly upon reoxygenation than wild-type cells, suggesting that this inhibitor may play a role in preventing premature reentry into the cell cycle upon cessation of the hypoxic stress. While p27 null cells did not exhibit rapid reentry into the cell cycle, cells lacking both p21 and p27 entered S phase even more aggressively than those lacking p21 alone, revealing a possible secondary role for p27 in this response. Cdk2 activity is also restored more rapidly in the double-knockout cells when returned to normoxia. These studies reveal that restoration of DNA synthesis after hypoxic stress, but not the S phase arrest itself, is regulated by p21 and p27.

Topotecan Induces -Apoptosis in the Myelodysplastic Syndromes Cell Line MUTZ-1 That Is Associated with down Regulation of IAP Expression.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4713-4713
Author(s):  
Zhen Cai ◽  
Wenjun Wu Master
Keyword(s):  
Cell Cycle ◽  
Myelodysplastic Syndromes ◽  
S Phase ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Dna Ladder ◽  
Down Regulation ◽  
Transmission Electron ◽  
Induced Apoptosis ◽  
Dose Dependent

Abstract Myelodysplastic syndromes (MDS) represent a heterogenous group of clonal stem cell disorders with qualitative and quantitative abnormalities of blood cells and a high probability of evolving to acute leukemia. Intensive induction chemotherapy in order to reduce the malignant clone and reconstruct normal hematopoiesis is a classic therapy of MDS, especially high risk MDS. Topotecan (TPT), a semisynthetic water-soluble derivative of camptothecin, is a potent inhibitor of DNA topoisomerase I and has been extensively studied in hematologic malignances. However, little is known about how TPT acts against neoplastic cells. The aim of this study is to evaluate apoptotic effect of TPT on the MDS cell line MUTZ-1 and its associated changes in the expression of inhibitors of apoptosis protein (IAPs). The effect of TPT on MUTZ-1 growth was determined by using MTT assay. Characteristics associated with apoptosis induced by TPT were evaluated by transmission electron microscope, DNA gel electrophoresis and flow cytometry (FCM). Cell cycle shift were observed by FCM. Semi-quantitative RT-PCR was used to evaluate the mRNA expression of members of IAP gene family, including survivin, XIAP, Bcl-2, Bax, cIAP1 andcIAP2. The potential of mitochondrial membrane potential (MMP) was determined by using JC-1 probe. The results demonstrated that TPT significantly inhibited MUTZ-1 cell growth in a time- and dose-dependent manner with IC50 of 5.011 mmol/L, 1.297mmol/L and 0.483mmol/L at 24h, 48h and 72h respectively. Morphological features associated with TPT-induced apoptosis observed by transmission electron microscopy included cytoplasmic and nuclear shrinkage, karyorrhexis, nuclear convolution, chromatin condensation and margination, cytoplasmic vacuolization, and membrane-bound apoptotic bodies. An ambiguous DNA ladder was observed following treatment with 5mmol/L TPT for 24h, and a typical DNA ladder was observed with 10mmol/L TPT for 24h. The apoptotic rates were 11.69±0.51%, 34.07±1.73%, and 48.59±2.01%, respectively, after 24h culture with TPT as 1, 5, 10 μmol/L, significantly higher than that of the control (3.47%±0.3%; F=31.642, P<0.01). The percentage of MUTZ-1 cells in G2/M phase of the cell cycle decreased while in S and G0/G1 phase increased after treatment with 1mmol/L TPT for 24h,. The majority of the cells were arrested in S phase. After 24h culture with TPT at1, 5, and 10μmol/L, the mRNA levels of survivin, XIAP, cIAP1 and cIAP2 were decreased (P<0.01). This down-regulation was negatively correlated with TPT-induced apoptotic rates(P<0.05). There was no significant change in the Bax and Bcl-2 mRNA levels after TPT treatment (P>0.05). After 24h culture with 1μmol/L TPT, the MMP of TPT treated cells decreased significantly(P<0.01). Together, we conclude TPT can inhibit the growth and induce apoptosis of MUTZ-1 cells in a time- and dose- dependent manner. TPT can also induce the cell cycle changes, with the majoritoy of cells being arrested in S phase. The TPT-induced apoptosis in MUTZ-1 cells is associated with down-regulation of suvivin, XIAP, cIAP1and cIAP2 mRNA expresison. As well, MMP may be play a important role in the apoptotic process of MUTZ-1 cells induced by TPT.

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