Fas-Induced Apoptosis of Human Neutrophils is Promoted by Phosphatidyl Inositol 3-Kinase but Suppressed by P38-MAPK Activity

Abstract Fas belongs to the family of type-1 membrane proteins that transduce apoptotic signals. In the present studies, we characterized signaling during Fas-induced apoptosis in RPMI-8226 and IM-9 multiple myeloma (MM) derived cell lines as well as patient plasma cell leukemia cells. Treatment with anti-Fas (7C11) monoclonal antibody (MoAb) induced apoptosis, evidenced by internucleosomal DNA fragmentation and propidium iodide staining, and was associated with increased expression of c-jun early response gene. We also show that anti-Fas MoAb treatment is associated with activation of stress-activated protein kinase (SAPK) and p38 mitogen-activated protein kinase (MAPK); however, no detectable increase in extracellular signal-regulated kinases (ERK1 and ERK2) activity was observed. Because interleukin-6 (IL-6) is a growth factor for MM cells and inhibits apoptosis induced by dexamethasone and serum starvation, we examined whether IL-6 affects anti-Fas MoAb-induced apoptosis and activation of SAPK or p38 MAPK in MM cells. Culture of MM cells with IL-6 before treatment with anti-Fas MoAb significantly reduced both DNA fragmentation and activation of SAPK, without altering induction of p38 MAPK activity. These results therefore suggest that anti-Fas MoAb-induced apoptosis in MM cells is associated with activation of SAPK, and that IL-6 may both inhibit apoptosis and modulate SAPK activity.

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p38 Mitogen-Activated Protein Kinase (MAPK) Is a Key Mediator in Glucocorticoid-Induced Apoptosis of Lymphoid Cells: Correlation between p38 MAPK Activation and Site-Specific Phosphorylation of the Human Glucocorticoid Receptor at Serine 211

Molecular Endocrinology ◽

10.1210/me.2004-0528 ◽

2005 ◽

Vol 19 (6) ◽

pp. 1569-1583 ◽

Cited By ~ 147

Author(s):

Aaron L. Miller ◽

M. Scott Webb ◽

Alicja J. Copik ◽

Yongxin Wang ◽

Betty H. Johnson ◽

...

Keyword(s):

P38 Mapk ◽

Mapk Signaling ◽

Lymphoid Cells ◽

Mitogen Activated Protein Kinase ◽

Enzymatic Assays ◽

Mapk Activity ◽

Mitogen Activated Protein ◽

Elevated Activity ◽

Induced Apoptosis

Abstract Glucocorticoids (GCs) induce apoptosis in lymphoid cells through activation of the GC receptor (GR). We have evaluated the role of p38, a MAPK, in lymphoid cell apoptosis upon treatment with the synthetic GCs dexamethasone (Dex) or deacylcortivazol (DAC). The highly conserved phosphoprotein p38 MAPK is activated by specific phosphorylation of its threonine180 and tyrosine182 residues. We show that Dex and DAC stimulate p38 MAPK phosphorylation and increase the mRNA of MAPK kinase 3, a specific immediate upstream activator of p38 MAPK. Enzymatic assays confirmed elevated activity of p38 MAPK. Pharmacological inhibition of p38 MAPK activity was protective against GC-driven apoptosis in human and mouse lymphoid cells. In contrast, inhibition of the MAPKs, ERK and cJun N-terminal kinase, enhanced apoptosis. Activated p38 MAPK phosphorylates specific downstream targets. Because phosphorylation of the GR is affected by MAPKs, we examined its phosphorylation state in our system. We found serine 211 of the human GR to be a substrate for p38 MAPK both in vitro and intracellularly. Mutation of this site to alanine greatly diminished GR-driven gene transcription and apoptosis. Our results clearly demonstrate a role for p38 MAPK signaling in the pathway of GC-induced apoptosis of lymphoid cells.

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Interleukin-6 Inhibits Fas-Induced Apoptosis and Stress-Activated Protein Kinase Activation in Multiple Myeloma Cells

Blood ◽

10.1182/blood.v89.1.227.227_227_234 ◽

1997 ◽

Vol 89 (1) ◽

pp. 227-234 ◽

Cited By ~ 20

Author(s):

Dharminder Chauhan ◽

Surender Kharbanda ◽

Atsushi Ogata ◽

Mitsuyoshi Urashima ◽

Gerrard Teoh ◽

...

Keyword(s):

Multiple Myeloma ◽

Protein Kinase ◽

Dna Fragmentation ◽

P38 Mapk ◽

Interleukin 6 ◽

Early Response ◽

Mitogen Activated Protein Kinase ◽

Serum Starvation ◽

Mapk Activity ◽

Induced Apoptosis

Fas belongs to the family of type-1 membrane proteins that transduce apoptotic signals. In the present studies, we characterized signaling during Fas-induced apoptosis in RPMI-8226 and IM-9 multiple myeloma (MM) derived cell lines as well as patient plasma cell leukemia cells. Treatment with anti-Fas (7C11) monoclonal antibody (MoAb) induced apoptosis, evidenced by internucleosomal DNA fragmentation and propidium iodide staining, and was associated with increased expression of c-jun early response gene. We also show that anti-Fas MoAb treatment is associated with activation of stress-activated protein kinase (SAPK) and p38 mitogen-activated protein kinase (MAPK); however, no detectable increase in extracellular signal-regulated kinases (ERK1 and ERK2) activity was observed. Because interleukin-6 (IL-6) is a growth factor for MM cells and inhibits apoptosis induced by dexamethasone and serum starvation, we examined whether IL-6 affects anti-Fas MoAb-induced apoptosis and activation of SAPK or p38 MAPK in MM cells. Culture of MM cells with IL-6 before treatment with anti-Fas MoAb significantly reduced both DNA fragmentation and activation of SAPK, without altering induction of p38 MAPK activity. These results therefore suggest that anti-Fas MoAb-induced apoptosis in MM cells is associated with activation of SAPK, and that IL-6 may both inhibit apoptosis and modulate SAPK activity.

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p38 Mitogen-Activated Protein Kinase Mediates Palmitate-Induced Apoptosis But Not Inhibitor of Nuclear Factor-κB Degradation in Human Coronary Artery Endothelial Cells

Endocrinology ◽

10.1210/en.2006-1068 ◽

2007 ◽

Vol 148 (4) ◽

pp. 1622-1628 ◽

Cited By ~ 42

Author(s):

Weidong Chai ◽

Zhenqi Liu

Keyword(s):

Fatty Acids ◽

Endothelial Cells ◽

Coronary Artery ◽

P38 Mapk ◽

Fold Increase ◽

Nuclear Factor Κb ◽

Nuclear Factor ◽

Human Coronary Artery ◽

Mapk Activity ◽

Induced Apoptosis

Plasma free fatty acids are elevated in patients with type 2 diabetes and contribute to the pathogenesis of insulin resistance and endothelial dysfunction. The p38 MAPK mediates stress, inflammation, and apoptosis. Whether free fatty acids induce apoptosis and/or activate nuclear factor-κB inflammatory pathway in human coronary artery endothelial cells (hCAECs) and, if so, whether this involves the p38 MAPK pathway is unknown. hCAECs (passages 4–6) were grown to 70% confluence and then incubated with palmitate at concentrations of 0–300 μm for 6–48 h. Palmitate at 100, 200, or 300 μm markedly increased apoptosis after 12 h of incubation. This apoptotic effect was time (P = 0.008) and dose (P = 0.006) dependent. Palmitate (100 μm for 24 h) induced a greater than 2-fold increase in apoptosis, which was accompanied with a 4-fold increase in p38 MAPK activity (P < 0.001). Palmitate did not affect the phosphorylation of Akt1 or ERK1/2. SB203580 (a specific inhibitor of p38 MAPK) alone did not affect cellular apoptosis; however, it abolished palmitate-induced apoptosis and p38 MAPK activation. Palmitate significantly reduced the level of inhibitor of nuclear factor-κB (IκB). However, treatment of cells with SB203580 did not restore IκB to baseline. We conclude that palmitate induces hCAEC apoptosis via a p38 MAPK-dependent mechanism and may participate in coronary endothelial injury in diabetes. However, palmitate-mediated IκB degradation in hCAECs is independent of p38 MAPK activity.

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p38-MAPK Signals Survival by Phosphorylation of Caspase-8 and Caspase-3 in Human Neutrophils

Journal of Experimental Medicine ◽

10.1084/jem.20031771 ◽

2004 ◽

Vol 199 (4) ◽

pp. 449-458 ◽

Cited By ~ 130

Author(s):

Maria Alvarado-Kristensson ◽

Fredrik Melander ◽

Karin Leandersson ◽

Lars Rönnstrand ◽

Christer Wernstedt ◽

...

Keyword(s):

P38 Mapk ◽

Caspase 3 ◽

Mitogen Activated Protein Kinase ◽

Human Neutrophils ◽

Caspase 8 ◽

Neutrophil Apoptosis ◽

Mapk Activity ◽

Mitogen Activated Protein ◽

Phosphopeptide Mapping

Neutrophil apoptosis occurs both in the bloodstream and in the tissue and is considered essential for the resolution of an inflammatory process. Here, we show that p38–mitogen-activated protein kinase (MAPK) associates to caspase-8 and caspase-3 during neutrophil apoptosis and that p38-MAPK activity, previously shown to be a survival signal in these primary cells, correlates with the levels of caspase-8 and caspase-3 phosphorylation. In in vitro experiments, immunoprecipitated active p38-MAPK phosphorylated and inhibited the activity of the active p20 subunits of caspase-8 and caspase-3. Phosphopeptide mapping revealed that these phosphorylations occurred on serine-364 and serine-150, respectively. Introduction of mutated (S150A), but not wild-type, TAT-tagged caspase-3 into primary neutrophils made the Fas-induced apoptotic response insensitive to p38-MAPK inhibition. Consequently, p38-MAPK can directly phosphorylate and inhibit the activities of caspase-8 and caspase-3 and thereby hinder neutrophil apoptosis, and, in so doing, regulate the inflammatory response.

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Rare Chromone Derivatives from the Marine-Derived Penicillium citrinum with Anti-Cancer and Anti-Inflammatory Activities

Marine Drugs ◽

10.3390/md19010025 ◽

2021 ◽

Vol 19 (1) ◽

pp. 25

Author(s):

Yi-Cheng Chu ◽

Chun-Hao Chang ◽

Hsiang-Ruei Liao ◽

Ming-Jen Cheng ◽

Ming-Der Wu ◽

...

Keyword(s):

A549 Cells ◽

Penicillium Citrinum ◽

Signaling Cascades ◽

Human Neutrophils ◽

Cytotoxic Activities ◽

Western Blot Assay ◽

Chromone Derivatives ◽

Anti Cancer ◽

Ic50 Values ◽

Induced Apoptosis

Three new and rare chromone derivatives, epiremisporine C (1), epiremisporine D (2), and epiremisporine E (3), were isolated from marine-derived Penicillium citrinum, together with four known compounds, epiremisporine B (4), penicitrinone A (5), 8-hydroxy-1-methoxycarbonyl-6-methylxanthone (6), and isoconiochaetone C (7). Among the isolated compounds, compounds 2–5 significantly decreased fMLP-induced superoxide anion generation by human neutrophils, with IC50 values of 6.39 ± 0.40, 8.28 ± 0.29, 3.62 ± 0.61, and 2.67 ± 0.10 μM, respectively. Compounds 3 and 4 exhibited cytotoxic activities with IC50 values of 43.82 ± 6.33 and 32.29 ± 4.83 μM, respectively, against non-small lung cancer cell (A549), and Western blot assay confirmed that compounds 3 and 4 markedly induced apoptosis of A549 cells, through Bcl-2, Bax, and caspase 3 signaling cascades.

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Stromal-derived factor 1 and thrombopoietin regulate distinct aspects of human megakaryopoiesis

Blood ◽

10.1182/blood.v96.13.4142 ◽

2000 ◽

Vol 96 (13) ◽

pp. 4142-4151 ◽

Cited By ~ 108

Author(s):

Marcin Majka ◽

Anna Janowska-Wieczorek ◽

Janina Ratajczak ◽

M. Anna Kowalska ◽

Gaston Vilaire ◽

...

Keyword(s):

Protein Kinase ◽

Intracellular Signaling ◽

Phosphatidyl Inositol ◽

Mek Inhibitor ◽

Mitogen Activated Protein Kinase ◽

Proliferative Effect ◽

Normal Human ◽

And Migration ◽

Induced Apoptosis

Abstract The role of the chemokine binding stromal-derived factor 1 (SDF-1) in normal human megakaryopoiesis at the cellular and molecular levels and its comparison with that of thrombopoietin (TPO) have not been determined. In this study it was found that SDF-1, unlike TPO, does not stimulate αIIbβ3+ cell proliferation or differentiation or have an antiapoptotic effect. However, it does induce chemotaxis, trans-Matrigel migration, and secretion of matrix metalloproteinase 9 (MMP-9) and vascular endothelial growth factor (VEGF) by these cells, and both SDF-1 and TPO increase the adhesion of αIIbβ3+ cells to fibrinogen and vitronectin. Investigating the intracellular signaling pathways induced by SDF-1 and TPO revealed some overlapping patterns of protein phosphorylation/activation (mitogen-activated protein kinase [MAPK] p42/44, MAPK p38, and AKT [protein kinase B]) and some that were distinct for TPO (eg, JAK-STAT) and for SDF-1 (eg, NF-κB). It was also found that though inhibition of phosphatidyl-inositol 3-kinase (PI-3K) by LY294002 in αIIbβ3+ cells induced apoptosis and inhibited chemotaxis adhesion and the secretion of MMP-9 and VEGF, the inhibition of MAPK p42/44 (by the MEK inhibitor U0126) had no effect on the survival, proliferation, and migration of these cells. Hence, it is suggested that the proliferative effect of TPO is more related to activation of the JAK-STAT pathway (unique to TPO), and the PI-3K–AKT axis is differentially involved in TPO- and SDF-1–dependent signaling. Accordingly, PI-3K is involved in TPO-mediated inhibition of apoptosis, TPO- and SDF-1–regulated adhesion to fibrinogen and vitronectin, and SDF-1–mediated migration. This study expands the understanding of the role of SDF-1 and TPO in normal human megakaryopoiesis and indicates the molecular basis of the observed differences in cellular responses.

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