scholarly journals Glycoprotein 130 Regulates Cardiac Myocyte Survival in Doxorubicin-Induced Apoptosis Through Phosphatidylinositol 3-Kinase/Akt Phosphorylation and Bcl-xL/Caspase-3 Interaction

Circulation ◽  
2001 ◽  
Vol 103 (4) ◽  
pp. 555-561 ◽  
Author(s):  
Shinji Negoro ◽  
Hidemasa Oh ◽  
Eiroh Tone ◽  
Keita Kunisada ◽  
Yasushi Fujio ◽  
...  
Keyword(s):  
Caspase 3 ◽  
Cardiac Myocyte ◽  
Phosphatidylinositol 3 Kinase ◽  
Akt Phosphorylation ◽  
Induced Apoptosis ◽  
Phosphatidylinositol 3

Inhibition of Phosphatidylinositol 3-Kinase Amplifies TEGDMA-induced Apoptosis in Primary Human Pulp Cells

2004 ◽  
Vol 83 (9) ◽  
pp. 703-707 ◽  
Author(s):  
G. Spagnuolo ◽  
K. Galler ◽  
G. Schmalz ◽  
C. Cosentino ◽  
S. Rengo ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Triethylene Glycol ◽  
Fold Increase ◽  
Phosphatidylinositol 3 Kinase ◽  
Akt Phosphorylation ◽  
Pulp Cells ◽  
Induced Apoptosis ◽  
Apoptosis And Necrosis ◽  
Phosphatidylinositol 3

Cytotoxicity of triethylene glycol dimethacrylate (TEGDMA), a co-monomer of dental resinous restorative materials, is firmly established in vitro, but the molecular mechanisms are unknown. Here we examined apoptosis and necrosis induced by TEGDMA in human primary pulp cells. The levels of apoptotic and necrotic cell populations differentially increased after exposure to increasing concentrations of TEGDMA. A two-fold increase in the percentage of apoptotic cells was induced by 1 mmol/L TEGDMA. However, a population shift among cells in apoptosis and necrosis was detected when cell cultures were exposed to 2 mmol/L TEGDMA. Inhibition of the MAP Kinase/ERK pathway had no influence on cell survival, but inhibition of phosphatidylinositol 3 kinase (PI3-Kinase; Akt/protein kinase B) by LY294002 amplified TEGDMA-induced apoptosis. Moreover, Akt phosphorylation was inhibited in the presence of TEGDMA. These results suggest that depression of PI3K signaling may be a primary target in TEGDMA-induced apoptosis.

ERK promotes hydrogen peroxide-induced apoptosis through caspase-3 activation and inhibition of Akt in renal epithelial cells

2007 ◽  
Vol 292 (1) ◽  
pp. F440-F447 ◽  
Author(s):  
Shougang Zhuang ◽  
Yan Yan ◽  
Rebecca A. Daubert ◽  
Jiahuai Han ◽  
Rick G. Schnellmann
Keyword(s):  
Hydrogen Peroxide ◽  
Epithelial Cells ◽  
Caspase 3 ◽  
Ischemia Reperfusion ◽  
Nuclear Condensation ◽  
Histone H2b ◽  
Adenoviral Infection ◽  
Akt Phosphorylation ◽  
Renal Proximal Tubular Cells ◽  
Induced Apoptosis

Reactive oxygen species, including hydrogen peroxide (H2O2), are generated during ischemia-reperfusion and are critically involved in acute renal failure. The present studies examined the role of the extracellular signal-regulated kinase (ERK) pathway in H2O2-induced renal proximal tubular cells (RPTC) apoptosis. Exposure of RPTC to 1 mM H2O2resulted in apoptosis and activation of ERK1/2 and Akt. Pretreatment with the specific MEK inhibitors, U0126 and PD98059, or adenoviral infection with a construct that encodes a negative mutant of MEK1, protected cells against H2O2-induced apoptosis. In contrast, expression of constitutively active MEK1 enhanced H2O2-induced apoptosis. H2O2induced activation of caspase-3 and phosphorylation of histone H2B at serine 14, a posttranslational modification required for nuclear condensation, which also were blocked by ERK1/2 inhibition. Furthermore, blockade of ERK1/2 resulted in an increase in Akt phosphorylation and blockade of Akt potentiated apoptosis and diminished the protective effect conferred by ERK inhibition in H2O2-treated cells. Although Z-DEVD-FMK, a caspase-3 inhibitor, was able to inhibit histone H2B phosphorylation and apoptosis, it did not affect ERK1/2 phosphorylation. We suggest that ERK elicits apoptosis in epithelial cells by activating caspase-3 and inhibiting Akt pathways and elicits nuclear condensation through caspase-3 and histone H2B phosophorylation during oxidant injury.

Signals from type 1 sphingosine 1-phosphate receptors enhance adult mouse cardiac myocyte survival during hypoxia

2007 ◽  
Vol 293 (5) ◽  
pp. H3150-H3158 ◽  
Author(s):  
Jianqing Zhang ◽  
Norman Honbo ◽  
Edward J. Goetzl ◽  
Kanu Chatterjee ◽  
Joel S. Karliner ◽  
...  
Keyword(s):  
Cardiac Myocyte ◽  
Adult Mouse ◽  
Ventricular Myocytes ◽  
Mouse Cell ◽  
Biologically Active ◽  
Phosphatidylinositol 3 Kinase ◽  
Cytochrome C Release ◽  
Pharmacological Agents ◽  
Sphingosine 1 Phosphate ◽  
Phosphatidylinositol 3

Sphingosine 1-phosphate (S1P) is a biologically active lysophospholipid that serves as a key regulator of cellular differentiation and survival. Immune stimuli increase S1P synthesis and secretion by mast cells and platelets, implicating this molecule in tissue responses to injury and inflammation. Binding of S1P to Gi protein-coupled receptors activates phosphatidylinositol 3-kinase and Akt in a variety of tissues. To elucidate the mechanisms by which S1P enhances adult cardiac myocyte survival during hypoxia, we used a mouse cell culture system in which S1P1 receptors were observed to transduce signals from exogenous S1P, an S1P1 receptor antibody with agonist properties, and the pharmacological agents FTY720 and SEW2871. S1P1 receptor mRNA and protein were abundantly expressed by adult mouse cardiac myocytes. S1P-S1P1 receptor axis enhancement of myocyte survival during hypoxia was abolished by phosphatidylinositol 3-kinase inhibition. S1P1 receptor function was closely associated with activation of Akt, inactivation of GSK-3β, and reduction of cytochrome c release from heart mitochondria. These observations highlight the importance of S1P1 receptors on ventricular myocytes as mediators of inducible resistance against cellular injury during severe hypoxic stress.

scholarly journals Polyunsaturated fatty acids block platelet-activating factor-induced phosphatidylinositol 3 kinase/Akt-mediated apoptosis in intestinal epithelial cells

2008 ◽  
Vol 294 (5) ◽  
pp. G1181-G1190 ◽  
Author(s):  
Jing Lu ◽  
Michael S. Caplan ◽  
Dan Li ◽  
Tamas Jilling
Keyword(s):  
Fatty Acids ◽  
Polyunsaturated Fatty Acids ◽  
Intestinal Epithelial Cells ◽  
Platelet Activating Factor ◽  
Intestinal Epithelial ◽  
Akt Signaling Pathway ◽  
Phosphatidylinositol 3 Kinase ◽  
Protein Palmitoylation ◽  
Induced Apoptosis ◽  
Phosphatidylinositol 3

We have shown earlier that platelet-activating factor (PAF) causes apoptosis in enterocytes via a mechanism that involves Bax translocation to mitochondria, followed by caspase activation and DNA fragmentation. Herein we report that, in rat small intestinal epithelial cells (IEC-6), these downstream apoptotic effects are mediated by a PAF-induced inhibition of the phosphatidylinositol 3-kinase (PI 3-kinase)/protein kinase B (Akt) signaling pathway. Treatment with PAF results in rapid dephosphorylation of Akt, phosphoinositide-dependent kinase-1, and the YXXM p85 binding motif of several proteins and redistribution of Akt-pleckstrin homology domain-green fluorescent protein, i.e., an in vivo phosphatidylinositol ( 3 , 4 , 5 )-trisphosphate sensor, from membrane to cytosol. The proapoptotic effects of PAF were inhibited by both n-3 and n-6 polyunsaturated fatty acids but not by a saturated fatty acid palmitate. Indomethacin, an inhibitor of prostaglandin biosynthesis, did not influence the baseline or PAF-induced apoptosis, but 2-bromopalmitate, an inhibitor of protein palmitoylation, inhibited all of the proapoptotic effects of PAF. Our data strongly suggest that an inhibition of the PI 3-kinase/Akt signaling pathway is the main mechanism of PAF-induced apoptosis in enterocytes and that polyunsaturated fatty acids block this mechanism very early in the signaling cascade independently of any effect on prostaglandin synthesis, and probably directly via an effect on protein palmitoylation.

scholarly journals Nodal induces apoptosis through activation of the ALK7 signaling pathway in pancreatic INS-1 β-cells

2012 ◽  
Vol 303 (1) ◽  
pp. E132-E143 ◽  
Author(s):  
Fang Zhao ◽  
Fengjie Huang ◽  
Mengxiong Tang ◽  
Xiaoming Li ◽  
Nina Zhang ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Cell Apoptosis ◽  
Caspase 3 ◽  
Biological Effects ◽  
Cell Mass ◽  
Type I ◽  
Β Cells ◽  
Β Cell ◽  
Akt Phosphorylation ◽  
Induced Apoptosis

We demonstrated previously that the activation of ALK7 (activin receptor-like kinase-7), a member of the type I receptor serine/threonine kinases of the TGF-β superfamily, resulted in increased apoptosis and reduced proliferation through suppression of Akt signaling and the activation of Smad2-dependent signaling pathway in pancreatic β-cells. Here, we show that Nodal activates ALK7 signaling and regulates β-cell apoptosis. We detected Nodal expression in the clonal β-cell lines and rodent islet β-cells. Induction of β-cell apoptosis by treatment with high glucose, palmitate, or cytokines significantly increased Nodal expression in clonal INS-1 β-cells and isolated rat islets. The stimuli induced upregulation of Nodal expression levels were associated with elevation of ALK7 protein and enhanced phosphorylated Smad3 protein. Nodal treatment or overexpression of Nodal dose- or time-dependently increased active caspase-3 levels in INS-1 cells. Nodal-induced apoptosis was associated with decreased Akt phosphorylation and reduced expression level of X-linked inhibitor of apoptosis (XIAP). Remarkably, overexpression of XIAP or constitutively active Akt, or ablation of Smad2/3 activity partially blocked Nodal-induced apoptosis. Furthermore, siRNA-mediated ALK7 knockdown significantly attenuated Nodal-induced apoptosis of INS-1 cells. We suggest that Nodal-induced apoptosis in β-cells is mediated through ALK7 signaling involving the activation of Smad2/3-caspase-3 and the suppression of Akt and XIAP pathways and that Nodal may exert its biological effects on the modulation of β-cell survival and β-cell mass in an autocrine fashion.

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