Helicobacter pylori γ-glutamyl transpeptidase-induced Ca2+ release via PLC–IP3 receptors in AGS cells

2014 ◽  
Vol 60 (12) ◽  
pp. 865-868 ◽  
Author(s):  
Eun-Hee Park ◽  
Jung-Min Kim ◽  
Kyung-Mi Kim ◽  
Dawon Kang ◽  
Young-Ah Cho ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Dependent Manner ◽  
Ip3 Receptors ◽  
Ip3 Receptor ◽  
Ags Cells ◽  
Inositol 1,4,5 Trisphosphate ◽  
Intracellular Ca ◽  
Induced Apoptosis ◽  
Glutamyl Transpeptidase ◽  
Dose Dependent

In our previous study, γ-glutamyl transpeptidase (GGT) isolated from Helicobacter pylori induced apoptosis of AGS cells. Here, we investigate Ca2+ effects on GGT-induced apoptosis. The GGT transiently and significantly increased intracellular Ca2+ concentration ([Ca2+]i) in AGS cells in a dose-dependent manner (P < 0.05). The GGT-induced Ca2+ increase resulted from Ca2+ influx and release through the phospholipase C – inositol 1,4,5-trisphosphate (PLC–IP3) pathway. The GGT-induced apoptosis was significantly reduced by treatment with U73122 (a PLC inhibitor) and xestospongin (an IP3 receptor antagonist) (P < 0.05). These results indicate that GGT could induce apoptosis of AGS cells by high levels of [Ca2+]i.

scholarly journals Na/K-ATPase Tethers Phospholipase C and IP3 Receptor into a Calcium-regulatory Complex

2005 ◽  
Vol 16 (9) ◽  
pp. 4034-4045 ◽  
Author(s):  
Zhaokan Yuan ◽  
Ting Cai ◽  
Jiang Tian ◽  
Alexander V. Ivanov ◽  
David R. Giovannucci ◽  
...  
Keyword(s):  
Rat Kidney ◽  
Gradient Centrifugation ◽  
Dependent Manner ◽  
Ip3 Receptors ◽  
Ip3 Receptor ◽  
Caveolin 1 ◽  
Regulatory Complex ◽  
Intracellular Ca ◽  
Detergent Treatment ◽  
Central Loop

We have shown that the caveolar Na/K-ATPase transmits ouabain signals via multiple signalplexes. To obtain the information on the composition of such complexes, we separated the Na/K-ATPase from the outer medulla of rat kidney into two different fractions by detergent treatment and density gradient centrifugation. Analysis of the light fraction indicated that both PLC-γ1 and IP3 receptors (isoforms 2 and 3, IP3R2 and IP3R3) were coenriched with the Na/K-ATPase, caveolin-1 and Src. GST pulldown assays revealed that the central loop of the Na/K-ATPase α1 subunit interacts with PLC-γ1, whereas the N-terminus binds IP3R2 and IP3R3, suggesting that the signaling Na/K-ATPase may tether PLC-γ1 and IP3 receptors together to form a Ca2+-regulatory complex. This notion is supported by the following findings. First, both PLC-γ1 and IP3R2 coimmunoprecipitated with the Na/K-ATPase and ouabain increased this interaction in a dose- and time-dependent manner in LLC-PK1 cells. Depletion of cholesterol abolished the effects of ouabain on this interaction. Second, ouabain induced phosphorylation of PLC-γ1 at Tyr783and activated PLC-γ1 in a Src-dependent manner, resulting in increased hydrolysis of PIP2. It also stimulated Src-dependent tyrosine phosphorylation of the IP3R2. Finally, ouabain induced Ca2+release from the intracellular stores via the activation of IP3 receptors in LLC-PK1 cells. This effect required the ouabain-induced activation of PLC-γ1. Inhibition of Src or depletion of cholesterol also abolished the effect of ouabain on intracellular Ca2+.

Endothelin-activated calcium signaling in enteric glia derived from neonatal guinea pig

1997 ◽  
Vol 272 (5) ◽  
pp. G1175-G1185 ◽  
Author(s):  
W. Zhang ◽  
G. Sarosi ◽  
D. Barnhart ◽  
D. I. Yule ◽  
M. W. Mulholland
Keyword(s):  
Guinea Pig ◽  
Glial Cells ◽  
Receptor Agonist ◽  
Digital Microscopy ◽  
Ip3 Receptors ◽  
Ip3 Receptor ◽  
Enteric Glia ◽  
Inositol 1,4,5 Trisphosphate ◽  
Etb Receptor ◽  
Dose Dependent

The ability of guinea pig enteric glia to respond to endothelins was examined using fura 2-based digital microscopy in glial cells derived from guinea pig taenia coli. Each isoform of endothelin (ET-1, ET-2, ET-3) evoked dose-dependent and equipotent increases in intracellular Ca2+ concentration ([Ca2+]i) and in percentage of cells responding, 4alaEt-1, an ETB receptor agonist, elicited similar [Ca2+]i increments. BQ-788, an ETB antagonist, inhibited [Ca2+]i responses to endothelin. Preincubation of glia with U-73122 a phospholipase C inhibitor, abolished the [Ca2+]i response to ET-3 exposure. Thapsigargin also eliminated ET-3-evoked Ca2+ signaling. The inositol 1,4,5-trisphosphate (IP3) receptor antagonist heparin, introduced into glial cells by radio frequency electroporation, blocked [Ca2+]i responses to ET-3 (100 nM) in 63% of glia. Sustained elevation in [Ca2+]i was abolished by removal of Ca2+ from the buffer and inhibited 85. -3% by Ni2+ (1 mM). Preincubation of glia with 100 nM phorbol 12-myristate 13-acetate (24 h) also inhibited sustained increments in [Ca2+]i by 87%. The presence of IP3 receptors in enteric glia was confirmed by immunofluorescent confocal microscopy.

scholarly journals The Common Inhalational Anesthetic Isoflurane Induces Apoptosis via  Activation of Inositol 1,4,5-Trisphosphate Receptors

2008 ◽  
Vol 108 (2) ◽  
pp. 251-260 ◽  
Author(s):  
Huafeng Wei ◽  
Ge Liang ◽  
Hui Yang ◽  
Qiujun Wang ◽  
Brian Hawkins ◽  
...  
Keyword(s):  
Calcium Release ◽  
B Lymphocyte ◽  
Receptor Activity ◽  
Wild Type ◽  
Ip3 Receptors ◽  
Ip3 Receptor ◽  
Knock Out ◽  
Inositol 1,4,5 Trisphosphate ◽  
Induced Apoptosis ◽  
Er Membrane

Background Isoflurane induces cell apoptosis by an unknown mechanism. The authors hypothesized that isoflurane activates inositol 1,4,5-trisphosphate (IP3) receptors on the endoplasmic reticulum (ER) membrane, causing excessive calcium release, triggering apoptosis. Methods The authors determined isoflurane-induced cytotoxicity by measuring caspase-3 activity, lactate dehydrogenase release, MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt) reduction, and imaging analysis of cell damage markers (annexin V and propidium iodide staining) in different cell types. The authors used the chicken B lymphocyte with a total knock-out of IP3 receptors, PC12 cells with elevated IP3 receptor activity (transfected with L286V presenilin 1), striatal cells with a knock-in of Q111 Huntingtin, and each cell line's corresponding wild-type controls. The authors also measured the isoflurane-evoked changes of calcium concentration in cytosol and/or mitochondria in these cells. Results Isoflurane induced apoptosis concentration- and time-dependently, and sequentially elevated cytosolic and then mitochondrial calcium in the chicken B-lymphocyte wild-type but not the IP3 receptor total knock-out cells. Thapsigargin, a calcium adenosine triphosphatase inhibitor on ER membranes, induced apoptosis and elevations of calcium in cytosol and mitochondria in both chicken B-lymphocyte wild-type and IP3 receptor total knock-out cells. Isoflurane induced significantly more neurotoxicity and greater calcium release from the ER in L286V PC12 and Q111 Huntingtin striatal cells than in their corresponding wild-type controls, both of which were significantly inhibited by the IP3 receptor antagonist xestospongin C. Conclusion These findings suggest that isoflurane activates the ER membrane IP3 receptor, producing excessive calcium release and triggering apoptosis. Neurons with enhanced IP3 receptor activity, as in certain cases of familial Alzheimer or Huntington disease, may be especially vulnerable to isoflurane cytotoxicity.

scholarly journals Nonylphenol Induces Apoptosis through ROS/JNK Signaling in a Spermatogonia Cell Line

2020 ◽  
Vol 22 (1) ◽  
pp. 307
Author(s):  
Hyun-Jung Park ◽  
Ran Lee ◽  
Hyunjin Yoo ◽  
Kwonho Hong ◽  
Hyuk Song
Keyword(s):  
Molecular Mechanisms ◽  
Mapk Signaling ◽  
Ros Generation ◽  
Dependent Manner ◽  
Jnk Signaling ◽  
Apoptosis Markers ◽  
Testicular Size ◽  
Spermatogonia Cell ◽  
Induced Apoptosis ◽  
Dose Dependent

Nonylphenol (NP) is an endocrine-disruptor chemical that negatively affects reproductive health. Testes exposure to NP results in testicular structure disruption and a reduction in testicular size and testosterone levels. However, the effects of NP on spermatogonia in testes have not been fully elucidated. In this study, the molecular mechanisms of NP in GC-1 spermatogonia (spg) cells were investigated. We found that cell viability significantly decreased and apoptosis increased in a dose-dependent manner when GC-1 spg cells were exposed to NP. Furthermore, the expression levels of the pro-apoptotic proteins increased, whereas anti-apoptosis markers decreased in NP-exposed GC-1 spg cells. We also found that NP increased reactive oxygen species (ROS) generation, suggesting that ROS-induced activation of the MAPK signaling pathway is the molecular mechanism of NP-induced apoptosis in GC-1 spg cells. Thus, NP could induce c-Jun phosphorylation; dose-dependent expression of JNK, MKK4, p53, and p38; and the subsequent inhibition of ERK1/2 and MEK1/2 phosphorylation. The genes involved in apoptosis and JNK signaling were also upregulated in GC-1 spg cells treated with NP compared to those in the controls. Our findings suggest that NP induces apoptosis through ROS/JNK signaling in GC-1 spg cells.

Dexamethasone-Induced Apoptosis of Human Monocytes Exposed to Immune Complexes. Intervention of CD95-and Xiap-Dependent Pathways

2005 ◽  
Vol 18 (3) ◽  
pp. 403-415 ◽  
Author(s):  
L. Ottonello ◽  
M. Bertolotto ◽  
F. Montecucco ◽  
P. Dapino ◽  
F. Dallegri
Keyword(s):  
Immune Complex ◽  
Immune Complexes ◽  
Therapeutic Option ◽  
Mek Inhibitor ◽  
Dependent Manner ◽  
Human Monocytes ◽  
Inflammatory Reactions ◽  
Activated Monocytes ◽  
Induced Apoptosis ◽  
Dose Dependent

Monocytes and macrophages play a key role in the initiation and persistence of inflammatory reactions. The possibility to interfere with the survival of these cells, once recruited and activated at sites of inflammation, is an attractive therapeutic option. Although resting monocytes are susceptible to pharmacologically induced apoptosis, no data are available about the possibility to modulate the survival of activated monocytes. The present work was planned to investigate if dexamethasone is able to promote apoptosis of human monocytes activated by immune complexes. When monocytes were cultured with immune complexes, a dose-dependent inhibition of apoptosis was observed. Dexamethasone stimulated apoptosis of resting and activated monocytes in a dose-dependent manner. Both the immune complex inhibitory activity and dexamethasone stimulatory properties depend on NF-kB/XIAP and Ras/MEK/ERK/CD95 pathways. In fact, the exposure of monocytes to immune complexes increased NF-kB activation and XIAP expression, which in turn were inhibited by dexamethasone. On the other hand, immune complex-stimulated monocytes displayed a reduced expression of CD95, which is prevented by dexamethasone, as well as by MEK inhibitor U0126. Furthermore, anti-CD95 ZB4 mAb prevented dexamethasone-induced apoptosis in immune complex-stimulated monocytes. Similarly, ZB4 inhibited dexamethasone-mediated augmentation of caspase 3 activity. The present findings suggest that Fc triggering by insoluble immune complexes result in the activation of two intracellular pathways crucial for the survival of monocytes: 1. Ras/MEK/ERK pathway responsible for the down-regulation of CD95 expression; 2. NF-kB pathway governing the expression of XIAP. Both the pathways are susceptible to inhibition by monocyte treatment with pharmacologic concentrations of dexamethasone.

Effects of pinacidil on coronary Ca2+-myosin phosphorylation in cold potassium cardioplegia model

2000 ◽  
Vol 279 (3) ◽  
pp. H882-H888 ◽  
Author(s):  
Naruto Matsuda ◽  
Kathleen G. Morgan ◽  
Frank W. Sellke
Keyword(s):  
Time Course ◽  
Dependent Manner ◽  
Coronary Smooth Muscle ◽  
Intracellular Ca ◽  
No Signaling ◽  
Synthase Inhibitor ◽  
Mlc Phosphorylation ◽  
Dose Dependent ◽  
Cardioplegic Solutions

The effects of the potassium (K+) channel opener pinacidil (Pin) on the coronary smooth muscle Ca2+-myosin light chain (MLC) phosphorylation pathway under hypothermic K+cardioplegia were determined by use of an in vitro microvessel model. Rat coronary arterioles (100–260 μm in diameter) were subjected to 60 min of simulated hypothermic (20°C) K+cardioplegic solutions (K+= 25 mM). We first characterized the time course of changes in intracellular Ca2+concentration, MLC phosphorylation, and diameter and observed that the K+cardioplegia-related vasoconstriction was associated with an activation of the Ca2+-MLC phosphorylation pathway. Supplementation with Pin effectively suppressed the Ca2+accumulation and MLC phosphorylation in a dose-dependent manner and subsequently maintained a small decrease in vasomotor tone. The ATP-sensitive K+(KATP)-channel blocker glibenclamide, but not the nitric oxide (NO) synthase inhibitor Nω-nitro-l-arginine methyl ester, significantly inhibited the effect of Pin. K+cardioplegia augments the coronary Ca2+-MLC pathway and results in vasoconstriction. Pin effectively prevents the activation of this pathway and maintains adequate vasorelaxation during K+cardioplegia through a KATP-channel mechanism not coupled with the endothelium-derived NO signaling cascade.

Acute reduction in whole cell conductance in anoxic turtle brain

1999 ◽  
Vol 277 (3) ◽  
pp. R887-R893 ◽  
Author(s):  
H. S. Ghai ◽  
L. T. Buck
Keyword(s):  
Brain Slices ◽  
Cell Voltage ◽  
Dependent Manner ◽  
Recording Electrode ◽  
Whole Cell ◽  
Artificial Cerebrospinal Fluid ◽  
Intracellular Ca ◽  
Specific Antagonist ◽  
Acute Changes ◽  
Dose Dependent

We tested the effect of anoxia, a “mimic” turtle artificial cerebrospinal fluid (aCSF) consisting of high Ca2+ and Mg2+ concentrations and low pH and adenosine perfusions, on whole cell conductance ( G w) in turtle brain slices using a whole cell voltage-clamp technique. With EGTA in the recording electrode, anoxic or adenosine perfusions did not change G w significantly (values range between 2.15 ± 0.24 and 3.24 ± 0.56 nS). However, perfusion with normoxic or anoxic mimic aCSF significantly decreased G w. High [Ca2+] (4.0 or 7.8 mM) perfusions alone could reproduce the changes in G w found with the mimic perfusions. With the removal of EGTA from the recording electrode, G wdecreased significantly during both anoxic and adenosine perfusions. The A1-receptor agonist N 6-cyclopentyladenosine reduced G w in a dose-dependent manner, whereas the A1-receptor specific antagonist 8-cyclopentyl-1,3-dipropylxanthine blocked both the adenosine- and anoxic-mediated changes in G w. These data suggest a mechanism involving A1-receptor-mediated changes in intracellular [Ca2+] that result in acute changes in G w with the onset of anoxia.

scholarly journals Emodin promotes apoptosis of human endometrial cancer through regulating the MAPK and PI3K/ AKT pathways

2019 ◽  
Vol 13 (1) ◽  
pp. 489-496 ◽  
Author(s):  
Jun Jiang ◽  
Nanyang Zhou ◽  
Pian Ying ◽  
Ting Zhang ◽  
Ruojia Liang ◽  
...  
Keyword(s):  
Endometrial Cancer ◽  
Signaling Pathways ◽  
Tumor Development ◽  
Mapk Signaling ◽  
Dependent Manner ◽  
Western Blot Assay ◽  
Anti Oxidant ◽  
Underlying Mechanisms ◽  
Induced Apoptosis ◽  
Dose Dependent

AbstractEmodin, a major component of rhubarb, has anti-tumor effects in a variety of cancers, influencing multiple steps of tumor development through modulating several signaling pathways. The aim of this study is to examine the effect of emodin on cell apoptosis and explore the underlying mechanisms in human endometrial cancer cells. Here we report that emodin can inhibit KLE cell proliferation and induce apoptosis in a time- and dose-dependent manner. Western blot assay found that emodin was involved in MAPK and PI3K/Akt signaling pathways. Specifically, emodin significantly suppressed the phosphorylation of AKT, and enhanced the phosphorylation of MAPK pathways. Furthermore, the generation of reactive oxygen species (ROS) was up-regulated in KLE cells upon treatment with emodin, while the anti-oxidant agent N-acetyl cysteine (NAC) can inhibit emodin-induced apoptosis and promote the activation of AKT and Bcl-2. Taken together, we revealed that emodin may induce apoptosis in KLE cells through regulating the PI3K/AKT and MAPK signaling pathways, indicating the importance of emodin as an anti-tumor agent.

Effect of Hydroxyapatite Nanoparticles of Different Concentrations on Rat Osteoblast

2009 ◽  
Vol 610-613 ◽  
pp. 1364-1369 ◽  
Author(s):  
Zheng Li Xu ◽  
Jiao Sun ◽  
Chang Sheng Liu ◽  
Jie Wei
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Control Group ◽  
Dependent Manner ◽  
Hydroxyapatite Nanoparticles ◽  
Inhibition Ratio ◽  
Rat Osteoblast ◽  
Induced Apoptosis ◽  
Dose Dependent

Nano-HAP (10-20nm) were obtained from East China University of Science and Technology. The osteoblasts were primary cultured from rat calvaria and then treated with five different concentrations(20，40，60，80，100µg/ml) of nano-HAP, the osteoblasts without nano-HAP was used as control group. Inhibition ratio, apoptotic rate were evaluated by MTT assay and flow cytometry (FCM), respectively. The specific surface area of nano-HAP was detected by BET. All date were expressed as mean ± standard deviation.Statistical analysis was performed by t test using software SPSS11.0 for Windows. The results indicated that the nano-HAP could inhibit the growth of osteoblasts in a dose-dependent manner. When the concentrations of nano-HAP were 20, 40, 60, 80, 100µg/ml, the inhibition ratio were 2.8%, 22.2%, 26.9%, 38% and 47.7%, and the apoptotic rate were 4.63%, 6.75%, 9.47%, 11.49%, 17.22%, respectively, which were obviously higher than that of control group. The nano-HAP significantly induced apoptosis in osteoblasts. There were the same tendency that the apoptotic and inhibition ratio of osteoblasts were rising with the increasing of the concentration of the nano-HAP. The specific surface area of nano-HAP was 148.140m2/g.

scholarly journals Effect of sphingosine derivatives on calcium fluxes in thyroid FRTL-5 cells

1994 ◽  
Vol 299 (1) ◽  
pp. 213-218 ◽  
Author(s):  
K Törnquist ◽  
E Ekokoski
Keyword(s):  
Elevated Level ◽  
Channel Blocker ◽  
Thyroid Stimulating Hormone ◽  
Thyroid Cell ◽  
Dependent Manner ◽  
Myristate Acetate ◽  
Permeabilized Cells ◽  
Inositol 1,4,5 Trisphosphate ◽  
Dose Dependent ◽  
In Cells

The effects of sphingosine derivatives on Ca2+ fluxes were investigated in thyroid FRTL-5 cells labelled with Fura 2. Addition of sphingosylphosphocholine (SPC) or sphingosine (SP) increased intracellular free Ca2+ ([Ca2+]i) in a dose-dependent manner. At the highest dose tested (30 microM), the response was biphasic: a rapid transient increase in [Ca2+]i, followed by a new, elevated, level of [Ca2+]i. Both phases of the SPC-evoked increase in [Ca2+]i were dependent on extracellular Ca2+, whereas only the SP-evoked elevated level of [Ca2+]i was dependent on the influx of Ca2+. Both compounds released sequestered Ca2+ from thapsigargin- and inositol 1,4,5-trisphosphate (IP3)-sensitive Ca2+ pools. In addition, the increase in [Ca2+]i in response to SPC, but not to SP, was attenuated in cells treated with phorbol myristate acetate or with the putative Ca(2+)-channel blocker SKF 96365, and in cells pretreated with pertussis toxin for 24 h. SPC did not activate the production of IP3. Furthermore, both SPC and SP released sequestered Ca2+ from permeabilized cells. We observed that SPC, but not SP, stimulated release of [3H]arachidonate from cells prelabelled with [3H]arachidonate for 24 h. Both SPC and SP stimulated the incorporation of [3H]thymidine into DNA in cells grown in the absence of thyroid-stimulating hormone (TSH). The results suggest that sphingosine derivatives are putative regulators of Ca2+ fluxes in FRTL-5 cells, and that SP and SPC may act on [Ca2+]i via different mechanisms. Furthermore, both SP and SPC may be of importance in modulating thyroid-cell proliferation.

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