Influence of Volatile Anesthetics on Thromboxane A2Signaling 

1998 ◽  
Vol 88 (2) ◽  
pp. 440-451 ◽  
Author(s):  
Christian W. Honemann ◽  
Gregor W. Nietgen ◽  
Tobias Podranski ◽  
Carrie K. Chan ◽  
Marcel E. Durieux
Keyword(s):  
Intracellular Signaling ◽  
Volatile Anesthetics ◽  
Smooth Muscle Contraction ◽  
Hill Coefficient ◽  
Receptor Protein ◽  
Maximal Effect ◽  
Allosteric Site ◽  
Inositol 1 ◽  
Intracellular Signaling Pathways

Background Thromboxane A2 (TXA2) is a member of the prostaglandin family; activation of its receptor induces several important effects, including platelet aggregation and smooth muscle contraction. Because volatile anesthetics interfere with aggregation and contraction, the authors investigated effects of halothane, isoflurane, and sevoflurane on TXA2 signaling in an isolated receptor model. Methods mRNA encoding TXA2 receptors was prepared in vitro and expressed in Xenopus oocytes. The effects of halothane, isoflurane, and sevoflurane on Ca2+-activated Cl- currents induced by the TXA2 agonist U-46619 and on those induced by intracellular injection of inositol 1-4-5 trisphosphate or guanosine 5'-O-(2-thiodiphosphate) were measured using the voltage-clamp technique. Results Expressed TXA2 receptors were functional (half maximal effect concentration [EC50], 3.2 x 10(-7) +/- 1.1 x 10(-7) M; Hill coefficient (h), 0.8 +/- 0.2). Halothane and isoflurane inhibition of TXA2 signaling was reversible and concentration dependent (halothane half maximal inhibitory concentration [IC50], 0.46 +/- 0.04 mM; h, 1.6 +/- 0.21; isoflurane IC50, 0.69 +/- 0.12 mM; h, 1.3 +/- 0.27). 0.56 mM halothane (1%) right-shifted the U-46619 concentration-response relationship by two orders of magnitude (EC50, 1 x 10[-5] M). That h and maximal effect (Emax) were unchanged indicates that halothane acts in a competitive manner. In contrast, isoflurane acted noncompetitively, decreasing Emax by 30% (h and EC50 were unchanged). Both halothane and isoflurane had no effect on intracellular signaling pathways. Sevoflurane (0-1.3 mM) did not affect TXA2 signaling. Conclusions Both halothane and isoflurane inhibit TXA2 signaling at the membrane receptor, but by different mechanisms. This suggests that the effects of these anesthetics on TXA2 signaling are evoked at different locations of the receptor protein: halothane probably acts at the ligand binding site and isoflurane at an allosteric site.

scholarly journals Caffeine Inhibits EGF-Stimulated Trophoblast Cell Motility through the Inhibition of mTORC2 and Akt

Endocrinology ◽  
2012 ◽  
Vol 153 (9) ◽  
pp. 4502-4510 ◽  
Author(s):  
Isobelle Grant ◽  
Judith E. Cartwright ◽  
Brooke Lumicisi ◽  
Alison E. Wallace ◽  
Guy S. Whitley
Keyword(s):  
Cell Motility ◽  
Signaling Pathways ◽  
Intracellular Signaling ◽  
Pregnancy Loss ◽  
Mammalian Target Of Rapamycin ◽  
First Trimester ◽  
Trophoblast Invasion ◽  
Intracellular Signaling Pathways

Impaired trophoblast invasion is associated with pregnancy disorders such as early pregnancy loss and preeclampsia. There is evidence to suggest that the consumption of caffeine during pregnancy may increase the risk of pregnancy loss; however, little is known about the direct effect of caffeine on normal trophoblast biology. Our objectives were to examine the effect of caffeine on trophoblast migration and motility after stimulation with epidermal growth factor (EGF) and to investigate the intracellular signaling pathways involved in this process. Primary first-trimester extravillous trophoblasts (EVT) and the EVT-derived cell line SGHPL-4 were used to study the effect of caffeine on EGF-stimulated cellular motility using time-lapse microscopy. SGHPL-4 cells were further used to study the effect of caffeine and cAMP on EGF-stimulated invasion of fibrin gels. The influence of caffeine and cAMP on EGF-stimulated intracellular signaling pathways leading to the activation of Akt were investigated by Western blot analysis. Caffeine inhibits both EGF-stimulated primary EVT and SGHPL-4 cell motility. EGF stimulation activates phosphatidylinositol 3-kinase, and Akt and caffeine inhibit this activation. Although cAMP inhibits both motility and invasion, it does not inhibit the activation of Akt, indicating that the effects of caffeine seen in this study are independent of cAMP. Further investigation indicated a role for mammalian target of rapamycin complex 2 (mTORC2) as a target for the inhibitory effect of caffeine. In conclusion, we demonstrate that caffeine inhibits EGF-stimulated trophoblast invasion and motility in vitro and so could adversely influence trophoblast biology in vivo.

scholarly journals Repurposing Tranexamic Acid as an Anticancer Agent

2021 ◽  
Author(s):  
Mary E Law ◽  
Bradley J Davis ◽  
Amanda F Ghilardi ◽  
Elham Yaaghubi ◽  
Zaafir M Dulloo ◽  
...  
Keyword(s):  
Tranexamic Acid ◽  
Anticancer Agents ◽  
Intracellular Signaling ◽  
Anticancer Agent ◽  
Lead Compounds ◽  
Intracellular Signaling Pathways ◽  
Multiple Processes ◽  
Broad Array

Tranexamic Acid (TA) is a clinically used antifibrinolytic that acts as a lysine mimetic to block binding of Plasminogen with Plasminogen activators, preventing conversion of Plasminogen to its proteolytically activated form, Plasmin. Previous studies suggested that TA may exhibit anticancer activity by blockade of extracellular Plasmin formation. Plasmin-mediated cleavage of the CDCP1 protein may increase its oncogenic functions through several downstream pathways. Results presented herein demonstrate that TA blocks Plasmin-mediated excision of the extracellular domain of the oncoprotein CDCP1. In vitro studies indicate that TA reduces the viability of a broad array of human and murine cancer cell lines, and breast tumor growth studies demonstrate that TA reduces cancer growth in vivo. Based on the ability of TA to mimic lysine and arginine, we hypothesized that TA may perturb multiple processes that involve Lys/Arg-rich protein sequences, and that TA may alter intracellular signaling pathways in addition to blocking extracellular Plasmin production. Indeed, TA-mediated suppression of tumor cell viability is associated with multiple biochemical actions, including inhibition of protein synthesis, reduced activating phosphorylation of STAT3 and S6K1, decreased expression of the MYC oncoprotein, and suppression of Lys acetylation. These findings suggest that TA or TA analogs may serve as lead compounds and inspire the production of new classes of anticancer agents that function by mimicking Lys and Arg.

Analysis of Differentially Activated Signaling Pathways in Myeloproliferative Disease Using Kinomics Chip Profiling

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3723-3723
Author(s):  
Daniel B Lipka ◽  
Marie-Christine Blum ◽  
Florian H Heidel ◽  
Thomas Kindler ◽  
Thomas Fischer
Keyword(s):  
Signaling Pathways ◽  
Cell Line ◽  
Intracellular Signaling ◽  
Jak2v617f Mutation ◽  
Myeloproliferative Disease ◽  
Differential Activation ◽  
Cell Lysate ◽  
Intracellular Signaling Pathways ◽  
Chip Analysis

Abstract In a multitude of cases, oncogenic mutations are gain of function mutations that confer a constitutively activated gene product. Currently, evidence from a large body of experimental studies suggests that oncogenic transformation induced by activating kinase mutations is not sufficiently explained by constitutive kinase activation alone but is a result of aberrantly activated signaling pathways in affected cells. The JAK2V617F-mutation is a highly prevalent molecular marker in Ph-negative myeloproliferative disease (MPD). In vitro, Ba/F3-cells expressing both erythropoietin receptor (EpoR) and the JAK2V617F-mutation show constitutive activation of the JAK-STAT pathway and cytokine independent growth. Multiple in-vitro and in-vivo studies demonstrate that the JAK2V617F-mutation mediates many of the phenotypic characteristics of the MPDs. Nevertheless, until now it is largely unclear, which signaling pathways in particular are involved in the process of malignant transformation in JAK2V617F-positive cells. Therefore, we applied a kinomics chip approach to screen for activated intracellular signaling pathways. We used a commercially available peptide chip containing 960 synthetic kinase substrate peptides spotted in triplicates and covering peptide substrates for approximately 50% of the human kinome. Peptides have been selected for their biologic relevance in physiologic processes such as stress response, growth and cell differentiation. With this approach, a broad spectrum of intracellular signaling pathways and kinases can be investigated simultaneously in a single experiment. As a proof of principle, we performed kinomics chip analysis of Ba/F3-cells stably transfected with EpoR and either the JAK2V617F-mutant (Ba/F3-EpoR-VF) or wildtype JAK2 (Ba/F3-EpoR-WT). In brief, cells were seeded and treated with erythropoietin. One chip per cell lysate was incubated with an activation buffer containing the cell lysate and radioactively labelled ATP for a defined time period and washed several times afterwards. The chip was then analyzed by means of autoradiography using a phospho-storage-screen and a phospho-imager. Chip analysis was performed using standard microarray software and Microsoft Excel software. Chip experiments were performed simultaneously for Ba/F3-EpoR-VF and Ba/F3-EpoR-WT and in duplicate. Analysis revealed differential activation of known pathways such as Ras/Raf/MEK/ERK, JAK/STAT, and PI3-Kinase with pronounced activation seen in Ba/F3-EpoR-VF cells as compared to Ba/F3-EpoR-WT cells. This was not a surprising result but strongly underlines the feasibility and validity of this approach and therefore served as an internal control. Differential regulation of a number of other signaling nodes that have not yet been described in the context of mutant JAK2 signaltransduction have been detected. To select for relevant hits among these potential targets, we first excluded all substrates from further analysis that are known to be involved in lymphocyte-specific pathways. For the remaining hits we performed a literature search to learn more about their known functions and their potential impact in JAK2V617F-positive MPD. Validation of selected signaling molecules by means of Western blotting analysis and functional investigations such as siRNA knock-down experiments are currently under way. In addition to the widely used lymphoid Ba/F3-model, we also established a novel cell culture model with simultaneous expression of EpoR and either mutant or wildtype JAK2 in a myeloid 32D-cell background. This model will be helpful to us to determine false-positive results due to cell-line specific changes. We conclude, that kinomic profiling using the above mentioned chip-technology is a valid method to comprehensively investigate differential activation of signaling pathways in cell lysates. In our cell line model, we were able to detect activation of well known signaling pathways in JAK2V617F-positive cells. Furthermore, we were able to identify candidate proteins that appear to be specifically involved in JAK2V617F-signaling.

scholarly journals Protosappanin B Exerts Anti-tumor Effects on Colon Cancer Cells via Inhibiting GOLPH3 Expression

2020 ◽  
Vol 19 ◽  
pp. 153473542097247
Author(s):  
Xue-Cong Zheng ◽  
Ze-Sheng Shi ◽  
Cheng-Zhi Qiu ◽  
Zhong-Shi Hong ◽  
Chun-Xiao Wang ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Cancer Cells ◽  
Signaling Pathways ◽  
Intracellular Signaling ◽  
Dependent Manner ◽  
Colon Cancer Cells ◽  
Human Colon Cancer ◽  
Intracellular Signaling Pathways ◽  
Sw620 Cells

Protosappanin B (PSB) is a key active component of Lignum Sappan extract. Although the antiproliferative effects of Lignum Sappan extract have been demonstrated in various cancer cells, relatively little is known about the effects of PSB on tumor progression. The aim of this study was to explore the anti-tumor effects of PSB on human colon cancer cells by regulation of intracellular signaling pathways and Golgi phosphoprotein 3 (GOLPH3) expression in vitro and in vivo. Our results showed that PSB effectively inhibited the viability and migration of SW620 cells and induced apoptosis, but had poor effect on HCT116 cells. Furthermore, PSB significantly reduced the expression of p-AKT, p-p70S6K, β-catenin, and p-ERK1/2 proteins in SW620 cells, and this effect was reversed by the corresponding signaling pathway agonists. Interestingly, PSB could also suppress GOLPH3 expression of SW620 cells in a concentration-dependent manner, but SW620 cells transfected with lentiviral vectors overexpressing GOLPH3 can effectively resist the cytotoxic activity of PSB in vitro. The xenograft experiment of SW620 cells with LV-GOLPH3 confirmed that PSB distinctly inhibited the tumor growth via suppressing GOLPH3 expression. Collectively, these findings clarified a new anti-cancer mechanism of PSB through inhibition of GOLPH3 expression and intracellular signaling pathways in colon cancer cells. PSB may be a potential new drug for colon cancer.

scholarly journals Peptide-based NTA(Ni)-nanodiscs for studying membrane enhanced FGFR1 kinase activities

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7234
Author(s):  
Juanjuan Liu ◽  
Lei Zhu ◽  
Xueli Zhang ◽  
Bo Wu ◽  
Ping Zhu ◽  
...  
Keyword(s):  
Intracellular Signaling ◽  
Plasma Membranes ◽  
Kinase Domain ◽  
Fibroblast Growth ◽  
Fibroblast Growth Factor Receptors ◽  
Intracellular Signaling Pathways ◽  
In Vitro Reconstitution ◽  
Tyrosine Autophosphorylation ◽  
Native Plasma

Tyrosine autophosphorylation plays a crucial regulatory role in the kinase activities of fibroblast growth factor receptors (FGFRs), and in the recruitment and activation of downstream intracellular signaling pathways. Biophysical and biochemical investigations of FGFR kinase domains in membrane environments offer key insights into phosphorylation mechanisms. Hence, we constructed nickel chelating nanodiscs based on a 22-residue peptide. The spontaneous anchoring of N-terminal His6-tagged FGFR1c kinase domain (FGFR1K) onto peptide nanodiscs grants FGFR1K orientations occurring on native plasma membranes. Following membrane incorporation, the autophosphorylation of FGFR1K, as exemplified by Y653 and Y654 in the A-loop and the total tyrosine phosphorylation, increase significantly. This in vitro reconstitution system may be applicable to studies of other membrane associated phenomena.

scholarly journals Repurposing Tranexamic Acid as an Anticancer Agent

2022 ◽  
Vol 12 ◽  
Author(s):  
Mary E. Law ◽  
Bradley J. Davis ◽  
Amanda F. Ghilardi ◽  
Elham Yaaghubi ◽  
Zaafir M. Dulloo ◽  
...  
Keyword(s):  
Tranexamic Acid ◽  
Anticancer Agents ◽  
Intracellular Signaling ◽  
Anticancer Agent ◽  
Lead Compounds ◽  
Intracellular Signaling Pathways ◽  
Multiple Processes ◽  
Broad Array

Tranexamic Acid (TA) is a clinically used antifibrinolytic agent that acts as a Lys mimetic to block binding of Plasminogen with Plasminogen activators, preventing conversion of Plasminogen to its proteolytically activated form, Plasmin. Previous studies suggested that TA may exhibit anticancer activity by blockade of extracellular Plasmin formation. Plasmin-mediated cleavage of the CDCP1 protein may increase its oncogenic functions through several downstream pathways. Results presented herein demonstrate that TA blocks Plasmin-mediated excision of the extracellular domain of the oncoprotein CDCP1. In vitro studies indicate that TA reduces the viability of a broad array of human and murine cancer cell lines, and breast tumor growth studies demonstrate that TA reduces cancer growth in vivo. Based on the ability of TA to mimic Lys and Arg, we hypothesized that TA may perturb multiple processes that involve Lys/Arg-rich protein sequences, and that TA may alter intracellular signaling pathways in addition to blocking extracellular Plasmin production. Indeed, TA-mediated suppression of tumor cell viability is associated with multiple biochemical actions, including inhibition of protein synthesis, reduced activating phosphorylation of STAT3 and S6K1, decreased expression of the MYC oncoprotein, and suppression of Lys acetylation. Further, TA inhibited uptake of Lys and Arg by cancer cells. These findings suggest that TA or TA analogs may serve as lead compounds and inspire the production of new classes of anticancer agents that function by mimicking Lys and Arg.

Curcumin inhibits renal cyst formation and enlargement in vitro by regulating intracellular signaling pathways

2011 ◽  
Vol 654 (1) ◽  
pp. 92-99 ◽  
Author(s):  
Jinsheng Gao ◽  
Hong Zhou ◽  
Tianluo Lei ◽  
Li Zhou ◽  
Weidong Li ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Intracellular Signaling ◽  
Renal Cyst ◽  
Cyst Formation ◽  
Intracellular Signaling Pathways

scholarly journals Study of intracellular signaling pathways in Chronic Myeloproliferative Neoplasms

2018 ◽  
Author(s):  
Serena Martinelli
Keyword(s):  
Signaling Pathways ◽  
Intracellular Signaling ◽  
Myeloproliferative Neoplasms ◽  
Mtor Pathway ◽  
Janus Kinase ◽  
Pi3k Inhibitor ◽  
Chronic Myeloproliferative Neoplasms ◽  
Intracellular Signaling Pathways

A gain-of-function mutation in Janus kinase 2 (JAK2V617F) is at the basis of the majority of chronic myeloproliferative neoplasms (MPN). Enhanced activation of other downstream pathways including the PI3K/mTOR pathway has been documented as well. In this study we evaluated the effects of JAK1/2 inhibitors, alone and in combination with mTOR, with a dual mTOR/PI3K inhibitor and with a pan PI3K inhibitor in in-vitro and in-vivo MPN models. Our findings of strong synergy between the JAK2 inhibitors and mTOR/PI3K inhibitor suggested that we might be able to administer these drugs at lower concentrations than when the drugs are used individually. This provides a framework for combination trials using compounds in patients with myeloproliferative neoplasms

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