Protein kinase Cζ mediated Raf-1/extracellular-regulated kinase activation by daunorubicin

Blood ◽  
2003 ◽  
Vol 101 (4) ◽  
pp. 1543-1550 ◽  
Author(s):  
Véronique Mansat-De Mas ◽  
Hélène Hernandez ◽  
Isabelle Plo ◽  
Christine Bezombes ◽  
Nicolas Maestre ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Mapk Pathway ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Mek Inhibitor ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Protective Function ◽  
Erk Phosphorylation ◽  
Extracellular Regulated Kinase

In light of the emerging concept of a protective function of the mitogen-activated protein kinase (MAPK) pathway under stress conditions, we investigated the influence of the anthracycline daunorubicin (DNR) on MAPK signaling and its possible contribution to DNR-induced cytotoxicity. We show that DNR increased phosphorylation of extracellular-regulated kinases (ERKs) and stimulated activities of both Raf-1 and extracellular-regulated kinase 1 (ERK1) within 10 to 30 minutes in U937 cells. ERK1 stimulation was completely blocked by either the mitogen-induced extracellular kinase (MEK) inhibitor PD98059 or the Raf-1 inhibitor 8-bromo-cAMP (cyclic adenosine monophosphate). However, only partial inhibition of Raf-1 and ERK1 stimulation was observed with the antioxidant N-acetylcysteine (N-Ac). Moreover, the xanthogenate compound D609 that inhibits DNR-induced phosphatidylcholine (PC) hydrolysis and subsequent diacylglycerol (DAG) production, as well as wortmannin that blocks phosphoinositide-3 kinase (PI3K) stimulation, only partially inhibited Raf-1 and ERK1 stimulation. We also observed that DNR stimulated protein kinase C ζ (PKCζ), an atypical PKC isoform, and that both D609 and wortmannin significantly inhibited DNR-triggered PKCζ activation. Finally, we found that the expression of PKCζ kinase-defective mutant resulted in the abrogation of DNR-induced ERK phosphorylation. Altogether, these results demonstrate that DNR activates the classical Raf-1/MEK/ERK pathway and that Raf-1 activation is mediated through complex signaling pathways that involve at least 2 contributors: PC-derived DAG and PI3K products that converge toward PKCζ. Moreover, we show that both Raf-1 and MEK inhibitors, as well as PKCζ inhibition, sensitized cells to DNR-induced cytotoxicity.

scholarly journals Combined VEGFR and MAPK pathway inhibition in angiosarcoma

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Michael J. Wagner ◽  
Yasmin A. Lyons ◽  
Jean H. Siedel ◽  
Robert Dood ◽  
Archana S. Nagaraja ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Mapk Pathway ◽  
Combined Treatment ◽  
Mek Inhibitor ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
In Vivo Model ◽  
Mitogen Activated Protein

AbstractAngiosarcoma is an aggressive malignancy of endothelial cells that carries a high mortality rate. Cytotoxic chemotherapy can elicit clinical responses, but the duration of response is limited. Sequencing reveals multiple mutations in angiogenesis pathways in angiosarcomas, particularly in vascular endothelial growth factor (VEGFR) and mitogen-activated protein kinase (MAPK) signaling. We aimed to determine the biological relevance of these pathways in angiosarcoma. Tissue microarray consisting of clinical formalin-fixed paraffin embedded tissue archival samples were stained for phospho- extracellular signal-regulated kinase (p-ERK) with immunohistochemistry. Angiosarcoma cell lines were treated with the mitogen-activated protein kinase kinase (MEK) inhibitor trametinib, pan-VEGFR inhibitor cediranib, or combined trametinib and cediranib and viability was assessed. Reverse phase protein array (RPPA) was performed to assess multiple oncogenic protein pathways. SVR angiosarcoma cells were grown in vivo and gene expression effects of treatment were assessed with whole exome RNA sequencing. MAPK signaling was found active in over half of clinical angiosarcoma samples. Inhibition of MAPK signaling with the MEK inhibitor trametinib decreased the viability of angiosarcoma cells. Combined inhibition of the VEGF and MAPK pathways with cediranib and trametinib had an additive effect in in vitro models, and a combinatorial effect in an in vivo model. Combined treatment led to smaller tumors than treatment with either agent alone. RNA-seq demonstrated distinct expression signatures between the trametinib treated tumors and those treated with both trametinib and cediranib. These results indicate a clinical study of combined VEGFR and MEK inhibition in angiosarcoma is warranted.

scholarly journals A yeast MAPK cascade regulates pexophagy but not other autophagy pathways

2010 ◽  
Vol 189 (2) ◽  
pp. 303-310 ◽  
Author(s):  
Ravi Manjithaya ◽  
Shveta Jain ◽  
Jean-Claude Farré ◽  
Suresh Subramani
Keyword(s):  
Protein Kinase ◽  
Mapk Pathway ◽  
Signal Transduction Pathway ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Mapk Cascade ◽  
Mitogen Activated Protein Kinase ◽  
Mitogen Activated Protein ◽  
Simultaneous Activation ◽  
Cellular Components

Autophagy is important for many cellular processes such as innate immunity, neurodegeneration, aging, and cancer. Although the signaling events triggering autophagy have been studied, little is known regarding the signaling mechanisms by which autophagy is redirected to achieve selective removal of cellular components. We have used the degradation of a peroxisomal marker to investigate the role of protein kinases in selective autophagy of peroxisomes (pexophagy) in Saccharomyces cerevisiae. We show that the Slt2p mitogen-activated protein kinase (MAPK) and several upstream components of its signal transduction pathway are necessary for pexophagy but not for pexophagosome formation or other nonselective and selective forms of autophagy. Other extracellular signals that activate this pathway do not trigger pexophagy on their own, suggesting that this MAPK cascade is necessary but not sufficient to trigger pexophagy. We propose that pexophagy requires the simultaneous activation of this MAPK pathway and a hexose-sensing mechanism acting through protein kinase A and cyclic adenosine monophosphate.

scholarly journals APPL1 mediates adiponectin-stimulated p38 MAPK activation by scaffolding the TAK1-MKK3-p38 MAPK pathway

2011 ◽  
Vol 300 (1) ◽  
pp. E103-E110 ◽  
Author(s):  
Xiaoban Xin ◽  
Lijun Zhou ◽  
Caleb M. Reyes ◽  
Feng Liu ◽  
Lily Q. Dong
Keyword(s):  
Protein Kinase ◽  
P38 Mapk ◽  
Mapk Pathway ◽  
Adaptor Protein ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Scaffolding Protein ◽  
Mapk Activation ◽  
P38 Mapk Pathway ◽  
Mitogen Activated Protein

The adaptor protein APPL1 mediates the stimulatory effect of adiponectin on p38 mitogen-activated protein kinase (MAPK) signaling, yet the underlying mechanism remains unclear. Here we show that, in C2C12 cells, overexpression or suppression of APPL1 enhanced or suppressed, respectively, adiponectin-stimulated p38 MAPK upstream kinase cascade, consisting of transforming growth factor-β-activated kinase 1 (TAK1) and mitogen-activated protein kinase kinase 3 (MKK3). In vitro affinity binding and coimmunoprecipitation experiments revealed that TAK1 and MKK3 bind to different regions of APPL1, suggesting that APPL1 functions as a scaffolding protein to facilitate adiponectin-stimulated p38 MAPK activation. Interestingly, suppressing APPL1 had no effect on TNFα-stimulated p38 MAPK phosphorylation in C2C12 myotubes, indicating that the stimulatory effect of APPL1 on p38 MAPK activation is selective. Taken together, our study demonstrated that the TAK1-MKK3 cascade mediates adiponectin signaling and uncovers a scaffolding role of APPL1 in regulating the TAK1-MKK3-p38 MAPK pathway, specifically in response to adiponectin stimulation.

scholarly journals Differential Signaling Profiles of MC4R Mutations with Three Different Ligands

2020 ◽  
Vol 21 (4) ◽  
pp. 1224 ◽  
Author(s):  
Sarah Paisdzior ◽  
Ioanna Maria Dimitriou ◽  
Paul Curtis Schöpe ◽  
Paolo Annibale ◽  
Patrick Scheerer ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
G Protein ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Loss Of Function ◽  
Melanocyte Stimulating Hormone ◽  
Melanocortin 4 Receptor ◽  
Erk Phosphorylation ◽  
Extracellular Regulated Kinase ◽  
Peptide Agonist

The melanocortin 4 receptor (MC4R) is a key player in hypothalamic weight regulation and energy expenditure as part of the leptin–melanocortin pathway. Mutations in this G protein coupled receptor (GPCR) are the most common cause for monogenetic obesity, which appears to be mediated by changes in the anorectic action of MC4R via GS-dependent cyclic adenosine-monophosphate (cAMP) signaling as well as other signaling pathways. To study potential bias in the effects of MC4R mutations between the different signaling pathways, we investigated three major MC4R mutations: a GS loss-of-function (S127L) and a GS gain-of-function mutant (H158R), as well as the most common European single nucleotide polymorphism (V103I). We tested signaling of all four major G protein families plus extracellular regulated kinase (ERK) phosphorylation and β-arrestin2 recruitment, using the two endogenous agonists, α- and β-melanocyte stimulating hormone (MSH), along with a synthetic peptide agonist (NDP-α-MSH). The S127L mutation led to a full loss-of-function in all investigated pathways, whereas V103I and H158R were clearly biased towards the Gq/11 pathway when challenged with the endogenous ligands. These results show that MC4R mutations can cause vastly different changes in the various MC4R signaling pathways and highlight the importance of a comprehensive characterization of receptor mutations.

scholarly journals Melanogenic Effects of Maclurin Are Mediated through the Activation of cAMP/PKA/CREB and p38 MAPK/CREB Signaling Pathways

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Young Sun Hwang ◽  
Sae Woong Oh ◽  
See-Hyoung Park ◽  
Jienny Lee ◽  
Ju Ah. Yoo ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Signaling Pathways ◽  
P38 Mapk ◽  
Adenosine Monophosphate ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Protective Agent ◽  
Protective Effects ◽  
Skin Disorders ◽  
Creb Phosphorylation

Melanogenesis is the biological process which the skin pigment melanin is synthesized to protect the skin against ultraviolet irradiation and other external stresses. Abnormal biology of melanocytes is closely associated with depigmented skin disorders such as vitiligo. In this study, we examined the effects of maclurin on melanogenesis and cytoprotection. Maclurin enhanced cellular tyrosinase activity as well as cellular melanin levels. We found that maclurin treatment increased the expression of microphthalmia-associated transcription factor (MITF), tyrosinase-related protein- (TRP-) 1, TRP-2, and tyrosinase. Mechanistically, maclurin promoted melanogenesis through cyclic adenosine monophosphate (cAMP) response element binding (CREB) protein-dependent upregulation of MITF. CREB activation was found to be mediated by p38 mitogen-activated protein kinase (MAPK) or cAMP-protein kinase A (PKA) signaling. In addition, maclurin-induced CREB phosphorylation was mediated through the activation of both the cAMP/PKA and the p38 MAPK signaling pathways. Maclurin-induced suppression of p44/42 MAPK activation also contributed to its melanogenic activity. Furthermore, maclurin showed protective effects against H2O2 treatment and UVB irradiation in human melanocytes. These findings indicate that the melanogenic effects of maclurin depend on increased MITF gene expression, which is mediated by the activation of both p38 MAPK/CREB and cAMP/PKA/CREB signaling. Our results thus suggest that maclurin could be useful as a protective agent against hypopigmented skin disorders.

scholarly journals 15-deoxy-Δ12,14-prostaglandin J2Down-Regulates Activin-Induced Activin Receptor, Smad, and Cytokines Expression via Suppression of NF-κB and MAPK Signaling in HepG2 Cells

PPAR Research ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Seung-Won Park ◽  
Chunghee Cho ◽  
Byung-Nam Cho ◽  
Youngchul Kim ◽  
Tae Won Goo ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Hepg2 Cells ◽  
Mapk Pathway ◽  
Mapk Signaling ◽  
Activin A ◽  
Mitogen Activated Protein Kinase ◽  
Erk Phosphorylation ◽  
Mitogen Activated Protein ◽  
Regulatory Effects ◽  
Activin Receptors

15-Deoxy-Δ12,14-prostaglandin J2(15d-PGJ2) and activin are implicated in the control of apoptosis, cell proliferation, and inflammation in cells. We examined both the mechanism by which 15d-PGJ2regulates the transcription of activin-induced activin receptors (ActR) and Smads in HepG2 cells and the involvement of the nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) pathways in this regulation. Activin A (25 ng/mL) inhibited HepG2 cell proliferation, whereas 15d-PGJ2(2 μM and 5 μM) had no effect. Activin A and 15d-PGJ2showed different regulatory effects on ActR and Smad expression, NF-κB p65 activity and MEK/ERK phosphorylation, whereas they both decreased IL-6 production and increased IL-8 production. When co-stimulated with 15d-PGJ2and activin, 15d-PGJ2inhibited the activin-induced increases in ActR and Smad expression, and decreased activin-induced IL-6 production. However, it increased activin-induced IL-8 production. In addition, 15d-PGJ2inhibited activin-induced NF-κB p65 activity and activin-induced MEK/ERK phosphorylation. These results suggest that 15d-PGJ2suppresses activin-induced ActR and Smad expression, down-regulates IL-6 production, and up-regulates IL-8 production via suppression of NF-κB and MAPK signaling pathway in HepG2 cells. Regulation of ActR and Smad transcript expression and cytokine production involves NF-κB and the MAPK pathway via interaction with 15d-PGJ2/activin/Smad signaling.

MEK inhibitors impair insulin-stimulated glucose uptake in 3T3-L1 adipocytes

2004 ◽  
Vol 287 (4) ◽  
pp. E758-E766 ◽  
Author(s):  
Anne W. Harmon ◽  
David S. Paul ◽  
Yashomati M. Patel
Keyword(s):  
Plasma Membrane ◽  
Glucose Uptake ◽  
Glucose Transporter ◽  
Mapk Pathway ◽  
Mek Inhibitor ◽  
Pi3k Pathway ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Mek Inhibitors ◽  
Transport Assay

In 3T3-L1 adipocytes, insulin activates three major signaling cascades, the phosphoinositide 3-kinase (PI3K) pathway, the Cbl pathway, and the mitogen-activated protein kinase (MAPK) pathway. Although PI3K and Cbl mediate insulin-stimulated glucose uptake by promoting the translocation of the insulin-responsive glucose transporter (GLUT4) to the plasma membrane, the MAPK pathway does not have an established role in insulin-stimulated glucose uptake. We demonstrate in this report that PI3K inhibitors also inhibit the MAPK pathway. To investigate the role of the MAPK pathway separately from that of the PI3K pathway in insulin-stimulated glucose uptake, we used two specific inhibitors of MAPK kinase (MEK) activity, PD-98059 and U-0126, which reduced insulin-stimulated glucose uptake by ∼33 and 50%, respectively. Neither MEK inhibitor affected the activation of Akt or PKCζ/λ, downstream signaling molecules in the PI3K pathway. Inhibition of MEK with U-0126 did not prevent GLUT4 from translocating to the plasma membrane, nor did it inhibit the subsequent docking and fusion of GLUT4- myc with the plasma membrane. MEK inhibitors affected glucose transport mediated by GLUT4 but not GLUT1. Importantly, the presence of MEK inhibitors only at the time of the transport assay markedly impaired both insulin-stimulated glucose uptake and MAPK signaling. Conversely, removal of MEK inhibitors before the transport assay restored glucose uptake and MAPK signaling. Collectively, our studies suggest a possible role for MEK in the activation of GLUT4.

scholarly journals Identification of RAS-Mitogen-Activated Protein Kinase Signaling Pathway Modulators in an ERF1 Redistribution® Screen

2006 ◽  
Vol 11 (4) ◽  
pp. 423-434 ◽  
Author(s):  
Charlotta Grånäs ◽  
Betina Kerstin Lundholt ◽  
Frosty Loechel ◽  
Hans-Christian Pedersen ◽  
Sara Petersen Bjørn ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Signaling Pathway ◽  
Kinase Inhibitors ◽  
Mapk Pathway ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Mitogen Activated Protein ◽  
A Cell ◽  
Protein Kinase Signaling

The RAS-mitogen-activated protein kinase (MAPK) signaling pathway has a central role in regulating the proliferation and survival of both normal and tumor cells. This pathway has been 1 focus area for the development of anticancer drugs, resulting in several compounds, primarily kinase inhibitors, in clinical testing. The authors have undertaken a cell-based, high-throughput screen using a novel ERF1 Redistribution® assay to identify compounds that modulate the signaling pathway. The hit compounds were subsequently tested for activity in a functional cell proliferation assay designed to selectively detect compounds inhibiting the proliferation of MAPK pathway-dependent cancer cells. The authors report the identification of 2 cell membrane-permeable compounds that exhibit activity in the ERF1 Redistribution® assay and selectively inhibit proliferation of MAPK pathway-dependent malignant melanoma cells at similar potencies (IC50 =< 5 μM). These compounds have drug-like structures and are negative in RAF, MEK, and ERK in vitro kinase assays. Drugs belonging to these compound classes may prove useful for treating cancers caused by excessive MAPK pathway signaling. The results also show that cell-based, high-content Redistribution® screens can detect compounds with different modes of action and reveal novel targets in a pathway known to be disease relevant.

scholarly journals Comparative Analysis of Transmembrane Regulators of the Filamentous Growth Mitogen-Activated Protein Kinase Pathway Uncovers Functional and Regulatory Differences

2015 ◽  
Vol 14 (9) ◽  
pp. 868-883 ◽  
Author(s):  
Hema Adhikari ◽  
Lauren M. Caccamise ◽  
Tanaya Pande ◽  
Paul J. Cullen
Keyword(s):  
Protein Kinase ◽  
Mapk Pathway ◽  
Filamentous Growth ◽  
Mapk Signaling ◽  
Fine Tuning ◽  
Mitogen Activated Protein Kinase ◽  
Rate Limiting Step ◽  
Mitogen Activated Protein ◽  
Multiple Signaling ◽  
Growth Pathway

ABSTRACTFilamentous growth is a microbial differentiation response that involves the concerted action of multiple signaling pathways. In budding yeast, one pathway that regulates filamentous growth is a Cdc42p-dependent mitogen-activated protein kinase (MAPK) pathway. Several transmembrane (TM) proteins regulate the filamentous growth pathway, including the signaling mucin Msb2p, the tetraspan osmosensor Sho1p, and an adaptor Opy2p. The TM proteins were compared to identify common and unique features. Msb2p, Sho1p, and Opy2p associated by coimmunoprecipitation analysis but showed predominantly different localization patterns. The different localization patterns of the proteins resulted in part from different rates of turnover from the plasma membrane (PM). In particular, Msb2p (and Opy2p) were turned over rapidly compared to Sho1p. Msb2p signaled from the PM, and its turnover was a rate-limiting step in MAPK signaling. Genetic analysis identified unique phenotypes of cells overexpressing the TM proteins. Therefore, each TM regulator of the filamentous growth pathway has its own regulatory pattern and specific function in regulating filamentous growth. This specialization may be important for fine-tuning and potentially diversifying the filamentation response.

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