scholarly journals Apoptosis Enhances the Replication of Human Coronavirus OC43

Viruses ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2199
Author(s):  
Sony Maharjan ◽  
Mijeong Kang ◽  
Jinsoo Kim ◽  
Dongbum Kim ◽  
Sangkyu Park ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Viral Replication ◽  
Molecular Mechanisms ◽  
Caspase 3 ◽  
Vero Cells ◽  
Caspase Inhibitor ◽  
Human Coronavirus ◽  
Cycle Arrest ◽  
Induced Apoptosis ◽  
Viral Reproduction

Human coronavirus OC43 (HCoV-OC43) is one of the coronaviruses causing a mild common cold, but few studies have been made on this strain. Here, we identified the molecular mechanisms involved in HCoV-OC43-induced apoptosis and its implications for viral reproduction in Vero cells and MRC-5 cells. HCoV-OC43 infection induced apoptosis that was accompanied by cleavage of caspase-3 and PARP, degradation of cyclin D1, and cell cycle arrest at S and G2M phases. Dephosphorylation of STAT1 and STAT3, induced by HCoV-OC43 infection, was also associated with HCoV-OC43-mediated apoptosis. The pan-caspase inhibitor effectively prevented HCoV-OC43-induced apoptosis and reduced viral replication, suggesting that apoptosis contributes to viral replication. Collectively our results indicate that HCoV-OC43 induces caspase-dependent apoptosis to promote viral replication in Vero cells and MRC-5 cells.

JNK/c-Jun Is Required for HMC-1 Cell Proliferation.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4439-4439
Author(s):  
Bin Wang ◽  
Junichi Tsukada ◽  
Takehiro Higashi ◽  
Takamitsu Mizobe ◽  
Ai Matsuura ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Mast Cells ◽  
Cell Cycle Arrest ◽  
Caspase 3 ◽  
Cyclin D3 ◽  
G1 Phase ◽  
Caspase 9 ◽  
Cycle Arrest ◽  
Induced Apoptosis

Abstract Activation of c-jun N-terminal kinase (JNK) through c-kit-mediated phosphatidylinositol 3 (PI3) and Src kinase pathways plays an important role in cell proliferation and survival in mast cells. Gain-of-function mutations in c-kit are found in several human neoplasms. Constitutive activation of c-kit has been observed in human mastocytosis, acute myeloid leukemia, lymphoma, germ tumor and gastrointestinal stromal tumor. In the present study, we demonstrate that an anthrapyrazole SP600125, a reversible ATP-competitive inhibitor of JNK inhibits proliferation of human HMC-1 mast cells expressing constitutively activated c-kit mutant. We found that JNK/c-Jun was constitutively activated in HMC-1 cells without stimulation. When spontaneous activation of JNK/c-Jun was inhibited by treatment with SP600125, cell proliferation was suppressed. The concentration which effectively inhibited JNK/c-Jun activity in our experiment had no effect on SCF-induced phosphorylation of Akt or Erk, suggesting that SP600125 specifically inhibited JNK/c-Jun activity in HMC-1 cells. Moreover, we demonstrated that SP600125 induced HMC-1 cell apoptosis in dose- and time-dependent manner. Caspase-3 and PARP were cleaved as early as 12 h after treatment with SP600125, but caspase-9 was not. Also, cell cycle arrest in G1 phase was observed in SP600125 treated cells. Thus, the inhibitory effect of SP600125 on cell proliferation was associated with cell cycle arrest at the G1 phase and apoptosis accompanied by cleavage of caspase-3 and PARP. Caspase-3 inhibitor Z-DEVD-FMK almost completely inhibited SP600125-induced apoptosis of HMC-1 cells. In contrast, caspase-9 inhibitor Z-LEHD-FMK failed to block SP600125-induced apoptosis, suggesting that apoptosis induced by SP600125 was caspase-3 dependent. Following SP600125 treatment, down-regulation of cyclin D3 protein expression, but not p53 was also observed. Take together, JNK/c-Jun is essential for proliferation and survival of HMC-1 cells. The results obtained from the present study suggest the possibility that JNK/c-Jun may be a therapeutic target in diseases associated with c-kit mutant.

Induction of cell cycle arrest and apoptosis by BCG infection in cultured human bronchial airway epithelial cells

2007 ◽  
Vol 293 (2) ◽  
pp. L393-L401 ◽  
Author(s):  
Yi-Mu Lai ◽  
Kamal A. Mohammed ◽  
Najmunnisa Nasreen ◽  
Aidos Baumuratov ◽  
Brendan F. Bellew ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Caspase 3 ◽  
Airway Epithelial Cells ◽  
Caspase 8 ◽  
Airway Epithelial ◽  
Cycle Arrest ◽  
Fas L ◽  
Induced Apoptosis ◽  
Partial Blockade

Bronchial airway epithelial cells (BAEpC) are among the first cells to encounter M. tuberculosis following airborne infection. However, the response of BAEpC to M. tuberculosis infection has been little studied. This study investigates the response of a human BAEpC cell line (BEAS-2B) to infection with Mycobacterium bovis Bacille Calmette Guerin (BCG). Cultured human BEAS-2B cells were experimentally infected with BCG. Uninfected BEAS-2B cultures were included as controls. Following infection, BEAS-2B cells were evaluated by various methods at various time points up to 3 days. Cell proliferation was evaluated by cellular bioreduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Distribution of cells along the cell cycle was evaluated by FACS analysis of cellular DNA. Apoptotic cells were identified by cell death ELISA and the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling method. Eighty-four apoptosis-relevant genes were screened by PCR gene microarray. Translation of Fas, Fas ligand (Fas-L), and Fas-associated death domain (FADD) were evaluated quantitatively by real-time PCR. Expression of Fas and FADD proteins was evaluated by immunofluorescence and Western blot. Activity of caspase-3 and caspase-8 was evaluated by colorimetric assay of their enzymatic activity. BCG infection of BEAS-2B cells inhibits proliferation, induces cell cycle arrest at the G0/G1phase, causes apoptosis, modulates transcription of multiple apoptosis-relevant genes, promotes translation of Fas, Fas-L, and FADD, upregulates expression of Fas and FADD proteins, and increases activity of caspase-3 and caspase-8. Infection with BCG does not cause any significant change in the secretion of TGF-β. The roles of Fas and FADD as mediators of BCG-induced apoptosis in BEAS-2B cells were tested by partial blockade of Fas and FADD expression with silencing RNA. Partial blockade of Fas or FADD expression results in a decreased apoptotic response to BCG infection. In conclusion, BCG induces cell cycle arrest and apoptosis in BEAS-2B cells. BCG induced apoptosis of BEAS-2B cells via the Fas death receptor pathway.

scholarly journals Pfaffosidic Fraction fromHebanthe paniculataInduces Cell Cycle Arrest and Caspase-3-Induced Apoptosis in HepG2 Cells

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Tereza Cristina da Silva ◽  
Bruno Cogliati ◽  
Andréia Oliveira Latorre ◽  
Gokithi Akisue ◽  
Márcia Kazumi Nagamine ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Hepg2 Cells ◽  
Caspase 3 ◽  
Cyclin E ◽  
Cellular Growth ◽  
Brdu Incorporation ◽  
Cycle Arrest ◽  
Brazilian Ginseng ◽  
Induced Apoptosis

Hebanthe paniculataroots (formerlyPfaffia paniculataand popularly known as Brazilian ginseng) show antineoplastic, chemopreventive, and antiproliferative properties. Functional properties of these roots and their extracts are usually attributed to the pfaffosidic fraction, which is composed mainly by pfaffosides A–F. However, the therapeutic potential of this fraction in cancer cells is not yet entirely understood. This study aimed to analyze the antitumoral effects of the purified pfaffosidic fraction or saponinic fraction on the human hepatocellular carcinoma HepG2 cell line. Cellular viability, proliferation, and apoptosis were evaluated, respectively, by MTT assay, BrdU incorporation, activated caspase-3 immunocytochemistry, and DNA fragmentation assay. Cell cycle was analyzed by flow cytometry and the cell cycle-related proteins were analyzed by quantitative PCR and Western blot. The cells exposed to pfaffosidic fraction had reduced viability and cellular growth, induced G2/M at 48 h or S at 72 h arrest, and increased sub-G1 cell population via cyclin E downregulation,p27KIP1overexpression, and caspase-3-induced apoptosis, without affecting the DNA integrity. Antitumoral effects of pfaffosidic fraction fromH. paniculatain HepG2 cells originated by multimechanisms of action might be associated with cell cycle arrest in the S phase, by CDK2 and cyclin E downregulation andp27KIP1overexpression, besides induction of apoptosis through caspase-3 activation.

scholarly journals Norcantharidin induces G2/M arrest and apoptosis via activation of ERK and JNK, but not p38 signaling in human renal cell carcinoma ACHN cells

2021 ◽  
Vol 71 (2) ◽  
pp. 267-278
Author(s):  
Shuaishuai Huang ◽  
Gulimire Tuergong ◽  
Hangjie Zhu ◽  
Xue Wang ◽  
Guobin Weng ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Renal Cell Carcinoma ◽  
Cell Carcinoma ◽  
Renal Cell ◽  
Caspase 3 ◽  
Phase Cell ◽  
Cycle Arrest ◽  
M Phase ◽  
Induced Apoptosis ◽  
Dose Dependent

AbstractRenal cell carcinoma (RCC) is generally acknowledged as the most resistant primary malignancy unresponsive to conventional radiotherapy and chemotherapy treatments. Norcantharidin (NCTD), a therapeutic compound derived from medicinal plants, has been shown to trigger apoptosis, as well as antimetastatic and antioxidant activities in several tumor cells. However, NCTD’s mechanism of antitumor activity in the RCC cell line remains unclear. In this study, we report that NCTD led to a time- and dose-dependent inhibition of cell proliferation. It had also markedly induced apoptosis and G2/M phase cell cycle arrest in a dose-dependent manner by decreasing the expressions of pro-caspase-3, pro-caspase-9, cyclin B1, and pCDC25C while increasing active caspase-3, cleaved-PARP, P21, and pCDC2 levels. Interestingly, NCTD treatment provoked the phosphorylation of extracellular-regulated protein kinase (ERK) and c-Jun-N-terminal kinase (JNK), but not of p38 MAPK. Moreover, SCH772984 and SP600125, ERK and JNK inhibitors, respectively, could partially abolish NCTD-induced apoptosis and G2/M phase cell cycle arrest. Collectively, these findings suggest that NCTD might activate JNK and ERK signaling pathways, consequently inducing apoptosis and G2/M arrest through the modulation of related proteins. This study provided evidence that NCTD is a promising therapeutic drug for the treatment of RCC.

scholarly journals Bach1 Induces Endothelial Cell Apoptosis and Cell-Cycle Arrest through ROS Generation

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Xinhong Wang ◽  
Junxu Liu ◽  
Li Jiang ◽  
Xiangxiang Wei ◽  
Cong Niu ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Endothelial Cells ◽  
Cyclin D1 ◽  
Cell Cycle Arrest ◽  
Caspase 3 ◽  
Ros Production ◽  
Cycle Arrest ◽  
Mitochondrial Ros ◽  
Induced Apoptosis

The transcription factor BTB and CNC homology 1 (Bach1) regulates genes involved in the oxidative stress response and cell-cycle progression. We have recently shown that Bach1 impairs cell proliferation and promotes apoptosis in cultured endothelial cells (ECs), but the underlying mechanisms are largely uncharacterized. Here we demonstrate that Bach1 upregulation impaired the blood flow recovery from hindlimb ischemia and this effect was accompanied both by increases in reactive oxygen species (ROS) and cleaved caspase 3 levels and by declines in the expression of cyclin D1 in the injured tissues. We found that Bach1 overexpression induced mitochondrial ROS production and caspase 3-dependent apoptosis and its depletion attenuated H2O2-induced apoptosis in cultured human microvascular endothelial cells (HMVECs). Bach1-induced apoptosis was largely abolished when the cells were cultured with N-acetyl-l-cysteine (NAC), a ROS scavenger. Exogenous expression of Bach1 inhibited the cell proliferation and the expression of cyclin D1, induced an S-phase arrest, and increased the expression of cyclin E2, which were partially blocked by NAC. Taken together, our results suggest that Bach1 suppresses cell proliferation and induces cell-cycle arrest and apoptosis by increasing mitochondrial ROS production, suggesting that Bach1 may be a promising treatment target for the treatment of vascular diseases.

Efficacy and Mechanisms of Apoptosis Induction by Simultaneous Inhibition of PI3K with GDC-0941 and Blockade of Bcl-2 (ABT-737) or FLT3 (Sorafenib) In AML Cells In the Hypoxic Bone Marrow Microenvironment

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 777-777
Author(s):  
Linhua Jin ◽  
Yoko Tabe ◽  
Yixin Zhou ◽  
Takashi Miida ◽  
Michael Andreeff ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Bone Marrow ◽  
Cell Survival ◽  
Molecular Mechanisms ◽  
Apoptosis Induction ◽  
Cell Growth Inhibition ◽  
Hypoxic Conditions ◽  
Cycle Arrest ◽  
G1 Cell Cycle Arrest ◽  
Induced Apoptosis

Abstract Abstract 777 Hypoxia and the interactions with bone marrow (BM) stromal cells have emerged as important mechanisms of leukemia cell survival and chemoresistance. The PI3K-Akt-mTOR-HIF1a signaling pathway has been shown to be activated in response to hypoxia in several cancer models including AML. Therefore, effective targeting of PI3K/Akt signaling pathway could suppress AML cell survival in the hypoxic BM microenvironment. Furthermore, concomitant intra-pathway blockade, or inhibition of the key pro-survival pathways may be more effective. In this study, we investigated the anti-leukemia effects and molecular mechanisms of apoptosis induction in the context of hypoxic bone marrow microenvironment by simultaneous use of a selective Class I PI3K inhibitor GDC-0941 (Genentech) with BH3 mimetic ABT-737 (Abbott) or FLT3 inhibitor sorafenib in AML cells. For hypoxia experiments, AML cells with FLT3-ITD mutation and wild-type FLT3 (FLT3-ITD: MOLM13, MV4;11, wt-FLT3: HL60) were cultured under 1.0% O2 for at least 14 days to assure their continuous proliferation and survival. Under hypoxia, more cells accumulated in G0/G1 phase, indicating that hypoxic conditions promote cell cycle quiescence in leukemic cells. GDC-0941 treatment in normoxia resulted in a reduction of cell proliferation with G0/G1 cell cycle arrest and minimal apoptosis induction, in a time and concentration-dependent manner (IC50 at 48 hrs; 0.7 μM for HL-60, 0.9 μM for MOLM13, 0.7 μM for MV4;11). In hypoxia, GDC-0941 further enhanced cell growth inhibition and G0/G1 cell cycle arrest. Importantly, co-culture with BM mesenchymal stroma cells (MSC), which protected AML cells from cytarabine induced apoptosis, did not affect cell growth inhibition by GDC-0941 both in normoxia and hypoxia. Combined treatment of GDC-0941 synergistically enhanced the ABT-737- or sorafenib induced apoptosis under both normoxic- and hypoxic conditions (p<0.05). Combination Index of GDC-0941/ABT-737 was 0.25 for HL-60 and 0.86 for MOLM13 cells; GDC-0941/sorafenib 0.58 for MV4;11 and 0.65 for MOLM13. In FLT3/ITD harboring MOLM13 and MV4;11 cells, ABT-737 and GDC-0941/ABT-737, or sorafenib and GDC-0941/sorafenib-induced apoptosis was partially reversed by MSC co-culture in normoxia, but not in hypoxia. We next examined the molecular mechanisms of apoptosis induction by simultaneous blockade of PI3K and mutant FLT3 in MOLM13 cells. GDC-0941 inhibited phospho-AktSer473, irrespective of oxygen tension. Hypoxia increased/induced phosphorylation of AktSer473, and of the pro-survival serine/threonine-protein kinase Pim-1, known to promote hypoxia-induced chemoresistance. Pim-1 is a downstream target of Akt and FLT-3 signaling that promotes cell survival and inhibits apoptosis through Bcl-2-dependent mechanisms. While GDC-0941 or ABT-737 alone did not affect hypoxia-induced Pim-1 levels, the GDC-0941/ABT-737 combination down-regulated Pim-1 by 86% (24 hrs). Treatment with sorafenib induced Pim-1 down-regulation by itself by 70%. Under hypoxia, expression levels of Bcl-2 family proteins Bcl-2 and BIM were not significantly changed by any treatment and cell culture conditions. In turn, Mcl-1 expression was upregulated by MSC co-cultures. Further, sorafenib alone but not GDC-0941 or ABT-737 decreased Mcl-1 protein levels, which was reversed by MSC co-culture in hypoxia; in turn, the GDC-0941/sorafenib or GDC-0941/ABT-737 combination potently suppressed Mcl-1 expression under MSC/hypoxia conditions. These changes were associated with the observed apoptotic responses. In summary, our findings indicate that hypoxic conditions of BM microenvironment result in stimulation of the pro-survival Akt and PIM kinase pathways and increase anti-apoptotic Mcl-1 protein in AML cells with mutated FLT3. In turn, simultaneous blockade of PI3K and FLT3 pathways, or of PI3K and Bcl-2 results in inhibition of these signaling modules and synergistic induction of apoptosis in AML. This data suggest that combined inhibition of Bcl-2 with PI3K or FLT3-ITD may constitute a targeted approach to eradicate chemoresistant AML cells sequestered in the hypoxic BM niches. Disclosures: No relevant conflicts of interest to declare.

Preclinical Study Of The Bromodomain Inhibitor OTX015 In Acute Myeloid (AML) and Lymphoid (ALL) Leukemias

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4218-4218 ◽  
Author(s):  
Thorsten Braun ◽  
marie Magdelaine Coude ◽  
Jeannig Berrou ◽  
Sibyl Bertrand ◽  
Eugenia Riveiro ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Line ◽  
Cell Lines ◽  
Caspase 3 ◽  
K562 Cell Line ◽  
Cytochrome C Release ◽  
Cycle Arrest ◽  
Ic50 Values ◽  
Induced Apoptosis ◽  
Lymphoid Cell Lines

Abstract Background Bromodomain and extra-terminal (BET) proteins, including the ubiquitous BRD2/3/4 proteins, are epigenetic readers implicated in c-MYC transcription, cellular proliferation, cell-cycle progression, RNA elongation and DNA damage response. Using shRNA screening and BRD inhibitors, BRD4 has been established as a promising therapeutic target in acute leukemia (Zuber, Nature 2011). In the present study, we investigated the in vitro anti-leukemic effects of the small-molecule BRD2/3/4 inhibitor OTX015 (Oncoethix, Lausanne, Switzerland). Methods Expression of BRD2/3/4 and c-MYC was assessed by RQ-PCR in 5 myeloid (HL60, KG1, KG1a, K562, NOMO1) and 4 lymphoid (Jurkat, RS4-11, BV173, TOM1) leukemia cell lines and by Western blotting (WB) using commercial antibodies in the HL60, K562, Jurkat and RS4-11 lines. Nineteen AML and ten ALL patient banked leukemic cells were assayed by RQ-PCR only. Cell viability and IC50 values were assessed in cell lines by MTT assays after exposure to OTX015 (0.1nM-10µM) for 72h. Cell-cycle distribution was determined by cytofluorometric analysis detecting nuclear propidium iodide (PI) intercalation. Induction of apoptosis was evaluated in cell lines and patient cells by outer membrane phosphatidylserine exposure and PI incorporation at 72 hours with increasing doses of OTX015 (25nM-500nM). Caspase-3 activation and mitochondrial cytochrome c release were studied by immunofluorescence (IF). Maturation was assessed by morphological studies after MGG staining and detection of CD11b by FACS analysis. Modulation of BRD2/3/4 proteins was investigated by WB. Results OTX015 IC50 values were in the submicromolar range for KG1 and the MLL-driven NOMO1 cell lines (198.3 and 229.1nM, respectively), while K562 was the most resistant myeloid line, with an IC50 of 11.3µM. In contrast, in lymphoid cell lines tested, IC50 values ranged from 34.2 to 249.7nM, with the MLL-driven cell line RS4-11 being the most sensitive. Cell cycle arrest in subG1/G1 to S transition was observed in 8/9 cell lines and was most pronounced in RS4-11 and BV173. Significant apoptosis (up to 88% Annexin V positive cells) was only observed in KG1a and NOMO1 among myeloid cell lines, while OTX015 induced apoptosis in all lymphoid cell lines tested, ranging from 57% in RS4-11 to 90% in the BCR-ABL+ TOM1 cells. Similarly, OTX015 triggered caspase-dependent cell death, as NOMO1 and RS4-11 displayed significant caspase-3 activation and cytochrome c release, when compared to the resistant K562 cell line. Seven primary patient fresh samples (5 AML, 2ALL) were also analyzed. Ex vivo treatment induced apoptosis ranged from 35% to 87% in 6/7 patients. Exposure to OTX015 at 500nM for 7 days induced maturation in 51% and 65% of HL60 cells as detected by CD11b expression and morphology, respectively. Baseline expression of BRD2/3/4 varied among cell lines or patient samples, lower BRD2/3/4 expression levels were observed in the BCR-ABL+ K562 and BV173 cell lines, as well as in the 4 BCR-ABL+ ALL samples analyzed. Upon OTX015 exposure, down-regulation of the BRD4 target gene c-MYC was observed in all cell lines, without clear correlation with the proliferation inhibition rate and/or the intensity of induced apoptosis while no consistent BRD2/3/4 mRNAs down-regulation was seen. Interestingly, BRD2 protein was down-regulated in HL60, Jurkat and RS4-11 cell lines, but not in the K562 cell line. Conclusion OTX015 affects cell viability, induces cell cycle arrest in G1/S phase, and is able to induce significant apoptosis in leukemic cell lines and fresh AML and ALL samples at submicromolar drug concentrations. These concentrations were achieved in the serum of healthy volunteers after safe administration of the drug. With such characteristics, OTX015 appears to be an attractive anti-leukemic therapy, currently under early evaluation in a Phase Ib dose-escalation trial conducted in relapsed/refractory AML/ALL patients. Disclosures: Riveiro: Oncology Therapeutic Development: Employment. Herait:Oncoethix: Employment. Dombret:Oncoethix: Research Funding.

Sign in / Sign up

Export Citation Format

Share Document