scholarly journals Neuroprotective Signaling Pathways are Modulated by Adenosine in the Anoxia Tolerant Turtle

2010 ◽  
Vol 31 (2) ◽  
pp. 467-475 ◽  
Author(s):  
Gauri H Nayak ◽  
Howard M Prentice ◽  
Sarah L Milton
Keyword(s):  
Neuronal Damage ◽  
Primary Cultures ◽  
Protective Role ◽  
Mitogen Activated Protein Kinase ◽  
Protective Mechanisms ◽  
Downstream Effects ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Neuroprotective Signaling

Cumulative evidence shows a protective role for adenosine A1 receptors (A1R) in hypoxia/ischemia; A1R stimulation reduces neuronal damage, whereas blockade exacerbates damage. The signal transduction pathways may involve the mitogen-activated protein kinase (MAPK) pathways and serine/threonine kinase (AKT), with cell survival depending on the timing and degree of upregulation of these cascades as well as the balance between pro-survival and pro-death pathways. Here, we show in vitro that extracellular signal-regulated kinase (ERK1/2) and phosphatidylinositol 3-kinase (PI3-K/AKT) activation is dependent on A1R stimulation, with further downstream effects that promote neuronal survival. Phosphorylated ERK1/2 (p-ERK) and AKT (p-AKT) as well as Bcl-2 are upregulated in anoxic neuronally enriched primary cultures from turtle brain. This native upregulation is further increased by the selective A1R agonist 2-chloro- N-cyclopentyladenosine (CCPA), whereas the selective antagonist 8-cyclopentyl-1,3-dihydropylxanthine (DPCPX) decreases p-ERK and p-AKT expression. Conversely, A1R antagonism resulted in increases in phosphorylated JNK (p-JNK), p38 (p-p38), and Bax. As pathological and adaptive changes occur simultaneously during anoxia/ischemia in mammalian neurons, the turtle provides an alternative model to analyze protective mechanisms in the absence of evident pathologies.

scholarly journals Ras Mutation Impairs Epithelial Barrier Function to a Wide Range of Nonelectrolytes

2005 ◽  
Vol 16 (12) ◽  
pp. 5538-5550 ◽  
Author(s):  
James M. Mullin ◽  
James M. Leatherman ◽  
Mary Carmen Valenzano ◽  
Erika Rendon Huerta ◽  
Jon Verrechio ◽  
...  
Keyword(s):  
Tight Junctions ◽  
Mitogen Activated Protein Kinase ◽  
Epithelial Barrier ◽  
Epithelial Barrier Function ◽  
Downstream Effects ◽  
Extracellular Signal ◽  
Wide Range ◽  
Mitogen Activated Protein ◽  
Protein Kinase Signaling ◽  
Kinase Signaling Pathway

Although ras mutations have been shown to affect epithelial architecture and polarity, their role in altering tight junctions remains unclear. Transfection of a valine-12 mutated ras construct into LLC-PK1 renal epithelia produces leakiness of tight junctions to certain types of solutes. Transepithelial permeability of d-mannitol increases sixfold but transepithelial electrical resistance increases >40%. This indicates decreased paracellular permeability to NaCl but increased permeability to nonelectrolytes. Permeability increases to d-mannitol (Mr 182), polyethylene glycol (Mr 4000), and 10,000-Mr methylated dextran but not to 2,000,000-Mr methylated dextran. This implies a “ceiling” on the size of solutes that can cross a ras-mutated epithelial barrier and therefore that the increased permeability is not due to loss of cells or junctions. Although the abundance of claudin-2 declined to undetectable levels in the ras-overexpressing cells compared with vector controls, levels of occludin and claudins 1, 4, and 7 increased. The abundance of claudins-3 and -5 remained unchanged. An increase in extracellular signal-regulated kinase-2 phosphorylation suggests that the downstream effects on the tight junction may be due to changes in the mitogen-activated protein kinase signaling pathway. These selective changes in permeability may influence tumorigenesis by the types of solutes now able to cross the epithelial barrier.

scholarly journals Extracellular Signal-Regulated Kinases Phosphorylate Mitogen-Activated Protein Kinase Phosphatase 3/DUSP6 at Serines 159 and 197, Two Sites Critical for Its Proteasomal Degradation

2005 ◽  
Vol 25 (2) ◽  
pp. 854-864 ◽  
Author(s):  
Sandrine Marchetti ◽  
Clotilde Gimond ◽  
Jean-Claude Chambard ◽  
Thomas Touboul ◽  
Danièle Roux ◽  
...  
Keyword(s):  
Map Kinases ◽  
Fluorescent Protein ◽  
Proteasomal Degradation ◽  
Mitogen Activated Protein Kinase ◽  
Dependent Manner ◽  
Double Mutation ◽  
Extracellular Signal ◽  
Mitogen Activated Protein

ABSTRACT Mitogen-activated protein (MAP) kinase phosphatases (MKPs) are dual-specificity phosphatases that dephosphorylate phosphothreonine and phosphotyrosine residues within MAP kinases. Here, we describe a novel posttranslational mechanism for regulating MKP-3/Pyst1/DUSP6, a member of the MKP family that is highly specific for extracellular signal-regulated kinase 1 and 2 (ERK1/2) inactivation. Using a fibroblast model in which the expression of either MKP-3 or a more stable MKP-3-green fluorescent protein (GFP) chimera was induced by tetracycline, we found that serum induces the phosphorylation of MKP-3 and its subsequent degradation by the proteasome in a MEK1 and MEK2 (MEK1/2)-ERK1/2-dependent manner. In vitro phosphorylation assays using glutathione S-transferase (GST)-MKP-3 fusion proteins indicated that ERK2 could phosphorylate MKP-3 on serines 159 and 197. Tetracycline-inducible cell clones expressing either single or double serine mutants of MKP-3 or MKP-3-GFP confirmed that these two sites are targeted by the MEK1/2-ERK1/2 module in vivo. Double serine mutants of MKP-3 or MKP-3-GFP were more efficiently protected from degradation than single mutants or wild-type MKP-3, indicating that phosphorylation of either serine by ERK1/2 enhances proteasomal degradation of MKP-3. Hence, double mutation caused a threefold increase in the half-life of MKP-3. Finally, we show that the phosphorylation of MKP-3 has no effect on its catalytic activity. Thus, ERK1/2 exert a positive feedback loop on their own activity by promoting the degradation of MKP-3, one of their major inactivators in the cytosol, a situation opposite to that described for the nuclear phosphatase MKP-1.

scholarly journals Neuroprotective potential of isothiocyanates in an in vitro model of neuroinflammation

2020 ◽  
Author(s):  
Tiziana Latronico ◽  
Marilena Larocca ◽  
Serafina Milella ◽  
Anna Fasano ◽  
Rocco Rossano ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Neurological Diseases ◽  
Primary Cultures ◽  
Allyl Isothiocyanate ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Pcr Analysis ◽  
Ros Production ◽  
Mitogen Activated Protein

AbstractIsothiocyanates (ITCs), present as glucosinolate precursors in cruciferous vegetables, have shown anti-inflammatory, antioxidant and anticarcinogenic activities. Here, we compared the effects of three different ITCs on ROS production and on the expression of matrix metalloproteinase (MMP)-2 and -9, which represent important pathogenetic factors of various neurological diseases. Primary cultures of rat astrocytes were activated by LPS and simultaneously treated with different doses of Allyl isothiocyanate (AITC), 2-Phenethyl isothiocyanate (PEITC) and 2-Sulforaphane (SFN). Results showed that SFN and PEITC were able to counteract ROS production induced by H2O2. The zymographic analysis of cell culture supernatants evidenced that PEITC and SFN were the most effective inhibitors of MMP-9, whereas, only SFN significantly inhibited MMP-2 activity. PCR analysis showed that all the ITCs used significantly inhibited both MMP-2 and MMP-9 expression. The investigation on the mitogen-activated protein kinase (MAPK) signaling pathway demonstrated that ITCs modulate MMP transcription by inhibition of extracellular-regulated protein kinase (ERK) activity. Results of this study suggest that ITCs could be promising nutraceutical agents for the prevention and complementary treatment of neurological diseases associated with MMP involvement.

scholarly journals Overexpression of RASAL1 indicates poor prognosis and promotes invasion of ovarian cancer

2019 ◽  
Vol 14 (1) ◽  
pp. 133-140
Author(s):  
Rui-Xia Chang ◽  
Ai-Ling Cui ◽  
Lu Dong ◽  
Su-Ping Guan ◽  
Ling-Yan Jiang ◽  
...  
Keyword(s):  
Mitogen Activated Protein Kinase ◽  
Cell Counting ◽  
In Vitro Assays ◽  
Ovarian Adenocarcinoma ◽  
Invasion And Migration ◽  
Kaplan Meier ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
And Migration

AbstractRAS protein activator like-1 (RASAL1) exists in numerous human tissues and has been commonly demonstrated to act as a tumor suppressor in several cancers. This study aimed to identify the functional characteristics of RASAL1 in ovarian adenocarcinoma and a potential mechanism of action. We analyzed RASAL1 gene expression in ovarian adenocarcinoma samples and normal samples gained from the GEO and Oncomine databases respectively. Then the relationship between RASAL1 expression and overall survival (OS) was assessed using the Kaplan-Meier method. Furthermore, the biological effect of RASAL1 in ovarian adenocarcinoma cell lines was assessed by Quantitative real time-PCR (qRT-PCR), Cell Counting Kit-8 (CCK-8), western blot, wound healing and transwell assay. The statistical analysis showed patients with higher RASAL1 expression correlated with worse OS. The in vitro assays suggested knockdown of RASAL1 could inhibit cell proliferation, cell invasion and migration of ovarian adenocarcinoma. Moreover, the key proteins in the mitogen-activated protein kinase/extracellular signal-regulated kinase (MEK/ERK) signaling pathway were also decreased in ovarian adenocarcinoma cells with RASAL1 silencing. These findings provide promising evidence that RASAL1 may be not only a powerful biomarker but also an effective therapeutic target of ovarian adenocarcinoma.

scholarly journals IQGAP1 Is a Scaffold for Mitogen-Activated Protein Kinase Signaling

2005 ◽  
Vol 25 (18) ◽  
pp. 7940-7952 ◽  
Author(s):  
Monideepa Roy ◽  
Zhigang Li ◽  
David B. Sacks
Keyword(s):  
Growth Factor ◽  
Map Kinase ◽  
Mitogen Activated Protein Kinase ◽  
Kinase Signaling ◽  
Cellular Functions ◽  
Molecular Scaffold ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Erk Activity

ABSTRACT IQGAP1 modulates many cellular functions such as cell-cell adhesion, transcription, cytoskeletal architecture, and selected signaling pathways. We previously documented that IQGAP1 binds extracellular signal-regulated kinase (ERK) 2 and regulates growth factor-stimulated ERK activity. Here we show that MEK, the molecule immediately upstream of ERK in the Ras/mitogen-activated protein (MAP) kinase signaling cascade, also interacts directly with IQGAP1. Both MEK1 and MEK2 bound IQGAP1 in vitro and coimmunoprecipitated with IQGAP1. The addition of ERK2 enhanced by fourfold the in vitro interaction of MEK2 with IQGAP1 without altering binding of MEK1. Similarly, ERK1 promoted MEK binding to IQGAP1, but either MEK protein altered the association between IQGAP1 and ERK. Epidermal growth factor (EGF) differentially regulated binding, enhancing MEK1 interaction while reducing MEK2 binding to IQGAP1. In addition, both knockdown and overexpression of IQGAP1 reduced EGF-stimulated activation of MEK and ERK. Analyses with selective IQGAP1 mutant constructs indicated that MEK binding is crucial for IQGAP1 to modulate EGF activation of ERK. Our data strongly suggest that IQGAP1 functions as a molecular scaffold in the Ras/MAP kinase pathway.

scholarly journals Phosphorylation of the ARE-binding protein DAZAP1 by ERK2 induces its dissociation from DAZ

2006 ◽  
Vol 399 (2) ◽  
pp. 265-273 ◽  
Author(s):  
Simon Morton ◽  
Huei-Ting Yang ◽  
Ntsane Moleleki ◽  
David G. Campbell ◽  
Philip Cohen ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Rna Binding ◽  
Binding Protein ◽  
Mitogen Activated Protein Kinase ◽  
Raw 264.7 ◽  
Raw 264.7 Macrophages ◽  
Hek 293 ◽  
Extracellular Signal ◽  
Mitogen Activated Protein

A protein in RAW 264.7 macrophages, which became phosphorylated in response to LPS (lipopolysaccharide), was identified as the RNA-binding protein called DAZAP1 [DAZ (deleted in azoospermia)-associated protein 1]. The phosphorylation of this protein was prevented by specific inhibition of MKK1 [MAPK (mitogen-activated protein kinase) kinase 1], indicating that it was phosphorylated via the classical MAPK cascade. Further experiments showed that DAZAP1 was phosphorylated stoichiometrically in vitro by ERK2 (extracellular-signal-regulated protein kinase 2) at two Thr-Pro sequences (Thr269 and Thr315), and that both sites became phosphorylated in HEK-293 (human embryonic kidney 293) cells in response to PMA or EGF (epidermal growth factor), or RAW 264.7 macrophages in response to LPS. Phosphorylation induced by each stimulus was prevented by two structurally distinct inhibitors of MKK1 (PD184352 and U0126), demonstrating that DAZAP1 is a physiological substrate for ERK1/ERK2. The mutation of Thr269 and Thr315 to aspartate or the phosphorylation of these residues caused DAZAP1 to dissociate from its binding partner DAZ. DAZ interacts with PABP [poly(A)-binding protein] and thereby stimulates the translation of mRNAs containing short poly(A) tails [Collier, Gorgoni, Loveridge, Cooke and Gray (2005) EMBO J. 24, 2656–2666]. In the present study we have shown that DAZ cannot bind simultaneously to DAZAP1 and PABP, and suggest that the phosphorylation-induced dissociation of DAZ and DAZAP1 may allow the former to stimulate translation by interacting with PABP.

Role of IFN-γ and IL-2 in rat lung epithelial cell migration and apoptosis after oxidant injury

2004 ◽  
Vol 286 (1) ◽  
pp. L4-L14 ◽  
Author(s):  
Olivier Lesur ◽  
Marcel Brisebois ◽  
Alexandre Thibodeau ◽  
Frédéric Chagnon ◽  
Denis Lane ◽  
...  
Keyword(s):  
Caspase 3 ◽  
Primary Cultures ◽  
Fold Increase ◽  
Protective Role ◽  
Scatchard Analysis ◽  
Membrane Expression ◽  
Extracellular Signal ◽  
Ifn Γ

In the present study, IFN-γ exposure to primary cultures of rat type II epithelial cells (TIIP) upregulated membrane expression of the common γ-chain of the IL-2 receptor (∼2.5- to 4-fold increase) and redistributed receptor affinity in TIIP, as assessed by Western blot, cell, and tissue histochemistry and Scatchard analysis. As for restitution processes of the lung epithelium, functionality of IL-2R on TIIP was conditional to IFN-γ exposure: 1) IFN-γ priming promoted a fivefold increase of IL-2-driven TIIP locomotion ( P < 0.05 vs. control at 100 U/ml) and 2) IFN-γ coincubation with IL-2 reduced bleomycin-induced TIIP apoptosis in vitro by 25% (caspase-3 activity) and by ∼70% (TdT-mediated dUTP nick end labeling/4′,6′-diamidino-2-phenylindole assay) as well as in vivo by ∼90% (caspase-3 activity; P < 0.05 vs. control). Sustained p42/44 extracellular signal-regulated kinase activity played a protective role in this process, whereas specific inhibition by PD-98059 (50 μM) significantly reversed bleomycin-induced TIIP apoptosis ( P < 0.05 vs. control). From these in vitro and in vivo data, it is proposed that combinations of IFN-γ and IL-2 can drive repair activity of TIIP by stimulating migration and preventing programmed cell death, both of which are speculated to be very fast restitution events after oxidant-induced acute lung injury.

scholarly journals ERK2 phosphorylates the epigenetic regulator CXXC-finger protein 1 (CFP1)

2019 ◽  
Author(s):  
Aroon S. Karra ◽  
Aileen M. Klein ◽  
Svetlana Earnest ◽  
Steve Stippec ◽  
Chonlarat Wichaidit ◽  
...  
Keyword(s):  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Early Gene ◽  
Highly Active ◽  
Finger Protein ◽  
Extracellular Signal ◽  
Epigenetic Regulator ◽  
Mitogen Activated Protein ◽  
Cxxc Finger Protein 1

AbstractBackgroundThe Ras-Raf-MEK-ERK signaling pathway is essential for proper development and homeostatic regulation in eukaryotic cells and underlies progression of several types of cancer. Many pathway functions are performed by extracellular signal-regulated kinase (ERK)1 and 2 (ERK1/2), serine/threonine protein kinases of the mitogen-activated protein kinase (MAPK) family that interact with a large number of substrates and are highly active in the nucleus.ResultsWe identified the epigenetic regulator CXXC-finger protein 1 (CFP1) as a protein that interacts with ERK2 on chromatin. CFP1 is involved in multiple aspects of chromatin regulation, including histone methylation and DNA methylation. Here, we demonstrate the overlapping roles for ERK1/2 and CFP1 in regulation of immediate early gene (IEG) induction. Our work suggests multiple modes of co-regulation and demonstrates that CFP1 is required for an optimal signal-dependent response. We also show that CFP1 is an ERK2 substrate in vitro and identify several phosphorylation sites. Furthermore, we provide evidence that Su(var)3-9, Enhancer-of-zeste and Trithorax (Set)1b, a CFP1-interacting histone methylase, is phosphorylated by ERK2 and is regulated by CFP1.ConclusionOur work highlights ERK1/2 interactions with chromatin regulators that contribute to MAPK signaling diversity in the nucleus.

scholarly journals Biofabrication of Cell-Derived Nanovesicles: A Potential Alternative to Extracellular Vesicles for Regenerative Medicine

Cells ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 1509 ◽  
Author(s):  
Nazma F. Ilahibaks ◽  
Zhiyong Lei ◽  
Emma A. Mol ◽  
Anil K. Deshantri ◽  
Linglei Jiang ◽  
...  
Keyword(s):  
Regenerative Medicine ◽  
Progenitor Cells ◽  
Extracellular Vesicles ◽  
Cost Effective ◽  
Mitogen Activated Protein Kinase ◽  
Hek293 Cells ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Size And Morphology

Extracellular vesicles (EVs) are mediators of intercellular communication by transferring functional biomolecules from their originating cells to recipient cells. This intrinsic ability has gained EVs increased scientific interest in their use as a direct therapeutic in the field of regenerative medicine or as vehicles for drug delivery. EVs derived from stem cells or progenitor cells can act as paracrine mediators to promote repair and regeneration of damaged tissues. Despite substantial research efforts into EVs for various applications, their use remains limited by the lack of highly efficient and scalable production methods. Here, we present the biofabrication of cell-derived nanovesicles (NVs) as a scalable, efficient, and cost-effective production alternative to EVs. We demonstrate that NVs have a comparable size and morphology as EVs, but lack standard EV (surface) markers. Additionally, in vitro uptake experiments show that human fetal cardiac fibroblast, endothelial cells, and cardiomyocyte progenitor cells internalize NVs. We observed that cardiac progenitor cell-derived NVs and EVs are capable of activating mitogen-activated protein kinase 1/2 (MAPK1/2)-extracellular signal-regulated kinase, and that both NVs and EVs derived from A431 and HEK293 cells can functionally deliver Cre-recombinase mRNA or protein to other cells. These observations indicate that NVs may have similar functional properties as EVs. Therefore, NVs have the potential to be applied for therapeutic delivery and regenerative medicine purposes.

MKP-2: out of the DUSP-bin and back into the limelight

2012 ◽  
Vol 40 (1) ◽  
pp. 235-239 ◽  
Author(s):  
Ahmed Lawan ◽  
Emma Torrance ◽  
Sameer Al-Harthi ◽  
Muhannad Shweash ◽  
Sulaiman Alnasser ◽  
...  
Keyword(s):  
Cell Cycle Progression ◽  
Metabolic Disorders ◽  
Mitogen Activated Protein Kinase ◽  
Cycle Progression ◽  
Extracellular Signal Regulated Kinase ◽  
Dual Specificity ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Dual Specificity Phosphatases

The MKPs (mitogen-activated protein kinase phosphatases) are a family of at least ten DUSPs (dual-specificity phosphatases) which function to terminate the activity of the MAPKs (mitogen-activated protein kinases). Several members have already been demonstrated to have distinct roles in immune function, cancer, fetal development and metabolic disorders. One DUSP of renewed interest is the inducible nuclear phosphatase MKP-2, which dephosphorylates both ERK (extracellular-signal-regulated kinase) and JNK (c-Jun N-terminal kinase) in vitro. Recently, the understanding of MKP-2 function has been advanced due to the development of mouse knockout models, which has resulted in the discovery of novel roles for MKP-2 in the regulation of sepsis, infection and cell-cycle progression that are distinct from those of other DUSPs. However, many functions for MKP-2 still await to be characterized.

Sign in / Sign up

Export Citation Format

Share Document