scholarly journals The MEK-ERK-MST1 Axis Potentiates the Activation of the Extrinsic Apoptotic Pathway during GDC-0941 Treatment in Jurkat T Cells

Cells ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 191 ◽  
Author(s):  
Jana Nováková ◽  
Pavel Talacko ◽  
Petr Novák ◽  
Karel Vališ
Keyword(s):  
T Cells ◽  
Caspase 3 ◽  
Phosphorylation Site ◽  
Conditional Knockout ◽  
Caspase 8 ◽  
Pi3k Signaling ◽  
Hippo Signaling ◽  
Dependent Manner ◽  
Jurkat T Cells ◽  
Apoptotic Pathway

The discrete activation of individual caspases is essential during T-cell development, activation, and apoptosis. Humans carrying nonfunctional caspase-8 and caspase-8 conditional knockout mice exhibit several defects in the progression of naive CD4+ T cells to the effector stage. MST1, a key kinase of the Hippo signaling pathway, is often presented as a substrate of caspases, and its cleavage by caspases potentiates its activity. Several studies have focused on the involvement of MST1 in caspase activation and also reported several defects in the immune system function caused by MST1 deficiency. Here, we show the rapid activation of the MEK-ERK-MST1 axis together with the cleavage and activation of caspase-3, -6, -7, -8, and -9 after PI3K signaling blockade by the selective inhibitor GDC-0941 in Jurkat T cells. We determined the phosphorylation pattern of MST1 using a phosphoproteomic approach and identified two amino acid residues phosphorylated in an ERK-dependent manner after GDC-0941 treatment together with a novel phosphorylation site at S21 residue, which was extensively phosphorylated in an ERK-independent manner during PI3K signaling blockade. Using caspase inhibitors and the inhibition of MST1 expression using siRNA, we identified an exclusive role of the MEK-ERK-MST1 axis in the activation of initiator caspase-8, which in turn activates executive caspase-3/-7 that finally potentiate MST1 proteolytic cleavage. This mechanism forms a positive feed-back loop that amplifies the activation of MST1 together with apoptotic response in Jurkat T cells during PI3K inhibition. Altogether, we propose a novel MEK-ERK-MST1-CASP8-CASP3/7 apoptotic pathway in Jurkat T cells and believe that the regulation of this pathway can open novel possibilities in systemic and cancer therapies.

scholarly journals Jasplakinolide Induces Apoptosis in Various Transformed Cell Lines by a Caspase-3-Like Protease-Dependent Pathway

2000 ◽  
Vol 7 (6) ◽  
pp. 947-952 ◽  
Author(s):  
Chikako Odaka ◽  
Miranda L. Sanders ◽  
Phillip Crews
Keyword(s):  
T Cells ◽  
Cell Death ◽  
Cell Lines ◽  
Caspase 3 ◽  
Dependent Manner ◽  
Jurkat T Cells ◽  
Transformed Cell ◽  
Induced Apoptosis ◽  
Transformed Cell Lines ◽  
Dependent Pathway

ABSTRACT To clarify the mechanisms underlying the antiproliferative effects of jasplakinolide, a cyclic depsipeptide from marine sponges, we examined whether jasplakinolide induces apoptosis in a variety of transformed and nontransformed cells. Jasplakinolide inhibited proliferation of human Jurkat T cells, resulting in cell death. This was accompanied by chromatin condensation and DNA cleavage at the linker regions between the nucleosomes. When caspase-3-like activity in the cytosolic extracts of Jurkat T cells was examined with a fluorescent substrate, DEVD-MAC (N-acetyl-Asp-Glu-Val-Asp-4-methyl-coumaryl-7-amide), the activity in the cells treated with jasplakinolide was remarkably increased in a time-dependent manner. Pretreatment of Jurkat T cells with the caspase inhibitor zVAD [benzyloxycarbonyl(Cbz)-Val-Ala-β-Asp(OMe)-fluoromethylketone] or DEVD-CHO (N-acetyl-Asp-Glu-Val-Asp-1-aldehyde) prevented the induction of apoptosis by jasplakinolide. Moreover, exposure of various murine transformed cell lines to jasplakinolide resulted in cell death, which was inhibited by zVAD. Although it has been well established that murine immature thymocytes are sensitive to apoptosis when exposed to various apoptotic stimuli, these cells as well as mature T lymphocytes were resistant to jasplakinolide-induced apoptosis. The results suggest that jasplakinolide induces apoptotic cell death through a caspase-3-like protease-dependent pathway. Another important outcome is that transformed cell lines were more susceptible to jasplakinolide-induced apoptosis than normal nontransformed cells.

scholarly journals In Vitro Effects of Ciprofloxacin and Roxithromycin on Apoptosis of Jurkat T Lymphocytes

2003 ◽  
Vol 47 (3) ◽  
pp. 1161-1164 ◽  
Author(s):  
Yong-Taek Jun ◽  
Hee-Jung Kim ◽  
Min-Jin Song ◽  
Ji-Hyang Lim ◽  
Dong-Gun Lee ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Death ◽  
Caspase 3 ◽  
Caspase 8 ◽  
Jurkat T Cells ◽  
Concentration Dependency ◽  
Enhanced Expression ◽  
In Vitro Effects ◽  
Induced Apoptosis

ABSTRACT Ciprofloxacin (CPFX) and roxithromycin (RXM) induced apoptosis of activated Jurkat T cells in vitro. CPFX showed concentration-dependent acceleration of apoptosis of activated Jurkat T cells by enhancing the expression of FasL and activities of caspase-3 and -8. RXM accelerated cell death, enhanced expression of FasL and caspase-3 but not caspase-8, and did not show the concentration dependency.

scholarly journals Enhancement of Quercetin-Induced Apoptosis by Cotreatment with Autophagy Inhibitor Is Associated with Augmentation of BAK-Dependent Mitochondrial Pathway in Jurkat T Cells

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Eun Ji Ha ◽  
Ki Yun Kim ◽  
Chae Eun Kim ◽  
Do Youn Jun ◽  
Young Ho Kim
Keyword(s):  
T Cells ◽  
Lymphoblastic Leukemia ◽  
Mitochondrial Damage ◽  
Parp Cleavage ◽  
Caspase 8 ◽  
Extrinsic Pathway ◽  
Jurkat T Cells ◽  
Apoptosis Pathway ◽  
Autophagy Inhibitor ◽  
Human T Cell

A flavonoid antioxidant quercetin promotes dose-dependent activation of the ATM-CHK-p53 pathway, downregulation of antiapoptotic survivin, and upregulation of proapoptotic NOXA in human T cell acute lymphoblastic leukemia Jurkat clones (J/Neo and J/BCL-XL). However, the downregulation of antiapoptotic BAG3 and MCL-1 occurred in J/Neo cells but not in J/BCL-XL cells overexpressing BCL-XL. Additionally, several BCL-XL-sensitive intrinsic mitochondrial apoptotic events including apoptotic sub-G1 cell accumulation, TUNEL-positive DNA fragmentation, BAK activation, mitochondrial membrane potential (Δψm) loss, caspase-9/caspase-8/caspase-3 activation, and PARP cleavage were induced only in J/Neo cells. Both cytosolic and mitochondrial ROS levels were elevated in quercetin-treated J/Neo cells; however, the ROS elevations were almost completely abrogated in J/BCL-XL cells, suggesting the ROS elevations were downstream of BCL-XL-sensitive mitochondrial damage and dysfunction. Wild-type A3, FADD-deficient I2.1, and caspase-8-deficient I9.2 Jurkat clones exhibited similar susceptibilities to the cytotoxicity of quercetin, excluding an involvement of extrinsic pathway in triggering the apoptosis. The autophagic events such as attenuation of AKT-mTOR pathway, formation of acridine orange-stainable acidic vesicular organelles, conversion of microtubule-associated protein 1 light chain 3-I (LC3-I) to LC3-II, and downregulation of p62/SQSTM1 level were detected in quercetin-treated J/Neo and J/BCL-XL cells, regardless of BCL-XL overexpression. Cotreatment with the autophagy inhibitor (3-methyladenine, LY294002, or chloroquine) resulted in a significant enhancement of quercetin-induced BAK activation and subsequently the mitochondrial damage-mediated apoptosis pathway by augmenting the downregulation of BAG3 and MCL-1 levels in J/Neo cells. These results demonstrated that quercetin induces intrinsic apoptosis and cytoprotective autophagy, and autophagy inhibition can potentiate BAK-dependent apoptotic activity of quercetin in Jurkat T cells.

Decrease of Bcl-xL and augmentation of thymocyte apoptosis in GILZ overexpressing transgenic mice

Blood ◽  
2004 ◽  
Vol 104 (13) ◽  
pp. 4134-4141 ◽  
Author(s):  
Domenico Vittorio Delfino ◽  
Massimiliano Agostini ◽  
Stefania Spinicelli ◽  
Pasquale Vito ◽  
Carlo Riccardi
Keyword(s):  
Transgenic Mice ◽  
Time Course ◽  
Leucine Zipper ◽  
Caspase 3 ◽  
Ex Vivo ◽  
Cell Lineage ◽  
Caspase 8 ◽  
Apoptotic Pathway ◽  
Cell Counts ◽  
Thymocyte Apoptosis

Abstract Glucocorticoids promote thymocyte apoptosis and modulate transcription of numerous genes. GILZ (glucocorticoid-induced leucine zipper), being one of them, is strongly up-regulated in the thymus. To elucidate its function we generated transgenic mice overexpressing it specifically in the T-cell lineage and characterized its influence on thymus function. In young adult transgenic mice CD4+CD8+ thymocyte number was significantly decreased and ex vivo thymocyte apoptosis was increased. Apoptotic pathway analysis detected reduced antiapoptotic B-cell leukemia XL (Bcl-xL) expression and increased activation of caspase-8 and caspase-3. Time-course experiments showed that in wild-type (WT) thymocytes GILZ up-regulation was followed by sequential Bcl-xL decreased expression and activation of caspase-8 and of caspase-3. Moreover, GILZ delivered inside WT thymocytes by a fusion protein with the transactivator of transcription (TAT) peptide decreased Bcl-xL and promoted their apoptosis. In aged mice perturbation of thymic subset numbers was amplified over time, as demonstrated by a further decrease in CD4+CD8+ cells and increases in CD4+CD8-, CD4-CD8-, and CD8+CD4- cell counts. These results support the hypothesis that GILZ participates in the regulation of thymocyte apoptosis by glucocorticoids. (Blood. 2004;104:4134-4141)

scholarly journals Caspase-8 inactivation in T cells increases necroptosis and suppresses autoimmunity in Bim−/− mice

2011 ◽  
Vol 195 (2) ◽  
pp. 277-291 ◽  
Author(s):  
Toshiyuki Bohgaki ◽  
Julien Mozo ◽  
Leonardo Salmena ◽  
Elzbieta Matysiak-Zablocki ◽  
Miyuki Bohgaki ◽  
...  
Keyword(s):  
T Cells ◽  
Death Receptor ◽  
Death Process ◽  
Caspase 8 ◽  
Intrinsic Apoptotic Pathway ◽  
Immune Disorders ◽  
Loss Of Function ◽  
T Cell Homeostasis ◽  
Apoptotic Pathway ◽  
Cell Death Process

Dysregulation of either the extrinsic or intrinsic apoptotic pathway can lead to various diseases including immune disorders and cancer. In addition to its role in the extrinsic apoptotic pathway, caspase-8 plays nonapoptotic functions and is essential for T cell homeostasis. The pro-apoptotic BH3-only Bcl-2 family member Bim is important for the intrinsic apoptotic pathway and its inactivation leads to autoimmunity that is further exacerbated by loss of function of the death receptor Fas. We report that inactivation of caspase-8 in T cells of Bim−/− mice restrained their autoimmunity and extended their life span. We show that, similar to caspase-8−/− T cells, Bim−/− T cells that also lack caspase-8 displayed elevated levels of necroptosis and that inhibition of this cell death process fully rescued the survival and proliferation of these cells. Collectively, our data demonstrate that inactivation of caspase-8 suppresses the survival and proliferative capacity of Bim−/− T cells and restrains autoimmunity in Bim−/− mice.

scholarly journals Bufalin Inhibits HCT116 Colon Cancer Cells and Its Orthotopic Xenograft Tumor in Mice Model through Genes Related to Apoptotic and PTEN/AKT Pathways

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Jie Wang ◽  
Chao Chen ◽  
Shiying Wang ◽  
Yong Zhang ◽  
Peihao Yin ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Tumor Growth ◽  
Cell Apoptosis ◽  
Caspase 3 ◽  
Cultured Cells ◽  
Xenograft Model ◽  
Dependent Manner ◽  
Apoptotic Pathway ◽  
Orthotopic Tumor ◽  
Orthotopic Xenograft

Aims. To investigate the anticolorectal cancer (CRC) effects of Bufalin, a bioactive polyhydroxysteroid from Venenum Bufonis, using HCT116 human CRC cell and an established orthotopic xenograft model in mice, and to explore the mechanisms of action.Material and Methods. Cultured HCT116 cells or BALB/c mice with orthotopic tumor were treated by Bufalin (positive control: 5-FU). Cell proliferation, apoptosis, and cycling were determined by MTT, Annexin V/PI staining, and flow cytometry, respectively. In mice, tumor inhibition rate and animal survival were calculated. The expressions of PTEN/phosphate-PTEN, AKT/phosphate-AKT, Bad, Bcl-xl, Bax, or Caspase-3 in cells and/or tumors were determined by Western blot or immunohistochemical staining.Results. Bufalin significantly inhibited cell proliferation and induced cell apoptosis and cycle arrest in a dose/time-dependent manner. In the animal model, Bufalin treatment resulted in significant inhibition of tumor growth and prolonged survival. In the Bufalin-treated cultured cells and/or xenograft tumors, the expressions of PTEN, Bad, Bax, and Caspase-3 were significantly increased, while p-AKT and Bcl-xL significantly decreased.Conclusions. Our results indicate that Bufalin inhibit cell proliferation and orthotopic tumor growth by inducing cell apoptosis through the intrinsic apoptotic pathway, which is of pivotal significance in the identification of an anticancer drug that may synergize with Bufalin.

scholarly journals Loureirin B Exerts its Immunosuppressive Effects by Inhibiting STIM1/Orai1 and KV1.3 Channels

2021 ◽  
Vol 12 ◽  
Author(s):  
Shujuan Shi ◽  
Qianru Zhao ◽  
Caihua Ke ◽  
Siru Long ◽  
Feng Zhang ◽  
...  
Keyword(s):  
T Cells ◽  
Molecular Mechanisms ◽  
Cell Model ◽  
Interleukin 2 ◽  
Immunosuppressive Effect ◽  
Dependent Manner ◽  
Jurkat T Cells ◽  
In The Wild ◽  
Resina Draconis ◽  
Loureirin B

Loureirin B (LrB) is a constituent extracted from traditional Chinese medicine Resina Draconis. It has broad biological functions and an impressive immunosuppressive effect that has been supported by numerous studies. However, the molecular mechanisms underlying Loureirin B-induced immune suppression are not fully understood. We previously reported that Loureirin B inhibited KV1.3 channel, calcium ion (Ca2+) influx, and interleukin-2 (IL-2) secretion in Jurkat T cells. In this study, we applied CRISPR/Cas9 to edit KV1.3 coding gene KCNA3 and successfully generated a KV1.3 knockout (KO) cell model to determine whether KV1.3 KO was sufficient to block the Loureirin B-induced immunosuppressive effect. Surprisingly, we showed that Loureirin B could still inhibit Ca2+ influx and IL-2 secretion in the Jurkat T cells in the absence of KV1.3 although KO KV1.3 reduced about 50% of Ca2+ influx and 90% IL-2 secretion compared with that in the wild type cells. Further experiments showed that Loureirin B directly inhibited STIM1/Orai1 channel in a dose-dependent manner. Our results suggest that Loureirin B inhibits Ca2+ influx and IL-2 secretion in Jurkat T cells by inhibiting both KV1.3 and STIM1/Orai1 channels. These studies also revealed an additional molecular target for Loureirin B-induced immunosuppressive effect, which makes it a promising leading compound for treating autoimmune diseases.

scholarly journals NeosedumosideIII induced Apoptosis of Human Hepatocellular Carcinoma HepG2 cells and SMMC-7721 Cells and Related Mechanism

2021 ◽  
Author(s):  
Xin-Yu Li ◽  
Xin Zhou ◽  
Yu- Liu ◽  
Feng Qiu ◽  
Qing-Qing Zhao
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Cycle ◽  
Hepg2 Cells ◽  
Caspase 3 ◽  
Human Hepatocellular Carcinoma ◽  
Caspase 8 ◽  
Dependent Manner ◽  
Caspase 9 ◽  
Induced Apoptosis

Abstract Purpose: NeosedumosideIII (Neo) is a megastigmanes and belongs to monocyclic sesquiterpenoids compound with antioxidant, anti-inflammatory and other pharmacological activities. In order to explore the anti-cancer effect and possible mechanism of Neo, the study examined the anti-proliferation and apoptosis effect of Neo against human hepatocellular carcinoma HepG2 cells and SMMC-772 cells and related mechanism in vitro. Methods ：The anti-proliferation effect of Neo was detected on HepG2 cells and SMMC-772 cells by MTT assay and IC50 with increasing dose and time. Cell cycle and apoptosis were detected by flow cytometer. The changes of Bcl-2, Bax, Caspase-3, Caspase-8 and Caspase-9 proteins were detected by western blotting.Results ：The results indicated that Neo could inhibited proliferation of HepG2 cells and SMMC-772 cells in vitro and promoted apoptosis, it significantly induced apoptosis of HepG2 cells and SMMC-772 cells arrested cell cycle at G0/G1 phase in a dose-dependent manner, reduce the expression of Bcl-2 protein, and increase the expression of Bax and Caspase-3, Caspase-8 and Caspase-9 proteins. Conclusion：Neo could inhibit proliferation and induce apoptosis of HepG2 cells and SMMC-7721 cells in vivo which suggested that it might be served as a promising candidate for the treatment of liver cancer.

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