scholarly journals The Ebola virus soluble glycoprotein contributes to viral pathogenesis by activating the MAP kinase signaling pathway

2021 ◽  
Vol 17 (9) ◽  
pp. e1009937
Author(s):  
Wakako Furuyama ◽  
Kyle Shifflett ◽  
Heinz Feldmann ◽  
Andrea Marzi
Keyword(s):  
Signaling Pathway ◽  
Ebola Virus ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Hek293 Cells ◽  
Huh7 Cells ◽  
Mitogen Activated Protein

Ebola virus (EBOV) expresses three different glycoproteins (GPs) from its GP gene. The primary product, soluble GP (sGP), is secreted in abundance during infection. EBOV sGP has been discussed as a potential pathogenicity factor, however, little is known regarding its functional role. Here, we analyzed the role of sGP in vitro and in vivo. We show that EBOV sGP has two different functions that contribute to infectivity in tissue culture. EBOV sGP increases the uptake of virus particles into late endosomes in HEK293 cells, and it activates the mitogen-activated protein kinase (MAPK) signaling pathway leading to increased viral replication in Huh7 cells. Furthermore, we analyzed the role of EBOV sGP on pathogenicity using a well-established mouse model. We found an sGP-dependent significant titer increase of EBOV in the liver of infected animals. These results provide new mechanistic insights into EBOV pathogenicity and highlight EBOV sGP as a possible therapeutic target.

scholarly journals Role of Muramyl Dipeptide in Lipopolysaccharide-Mediated Biological Activity and Osteoclast Activity

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Hideki Kitaura ◽  
Masahiko Ishida ◽  
Keisuke Kimura ◽  
Haruki Sugisawa ◽  
Akiko Kishikawa ◽  
...  
Keyword(s):  
Biological Activities ◽  
Muramyl Dipeptide ◽  
Mapk Signaling ◽  
Osteoclast Formation ◽  
Mitogen Activated Protein Kinase ◽  
Immunological Activity ◽  
Mitogen Activated Protein

Lipopolysaccharide (LPS) is an endotoxin and bacterial cell wall component that is capable of inducing inflammation and immunological activity. Muramyl dipeptide (MDP), the minimal essential structural unit responsible for the immunological activity of peptidoglycans, is another inflammation-inducing molecule that is ubiquitously expressed by bacteria. Several studies have shown that inflammation-related biological activities were synergistically induced by interactions between LPS and MDP. MDP synergistically enhances production of proinflammatory cytokines that are induced by LPS exposure. Injection of MDP induces lethal shock in mice challenged with LPS. LPS also induces osteoclast formation and pathological bone resorption; MDP enhances LPS induction of both processes. Furthermore, MDP enhances the LPS-induced receptor activator of NF-κB ligand (RANKL) expression and toll-like receptor 4 (TLR4) expression bothin vivoandin vitro. Additionally, MDP enhances LPS-induced mitogen-activated protein kinase (MAPK) signaling in stromal cells. Taken together, these findings suggest that MDP plays an important role in LPS-induced biological activities. This review discusses the role of MDP in LPS-mediated biological activities, primarily in relation to osteoclastogenesis.

The Role of MAPK's Signaling in Mediating ApoE4-Driven Pathology In Vivo

2019 ◽  
Vol 16 (4) ◽  
pp. 281-292 ◽  
Author(s):  
Shiran Salomon-Zimri ◽  
Amit Koren ◽  
Ariel Angel ◽  
Tali Ben-Zur ◽  
Daniel Offen ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Mapk Signaling ◽  
Mapk Signaling Pathway ◽  
Mitogen Activated Protein Kinase ◽  
Adeno Associated Virus ◽  
Immunoblot Assay ◽  
Total Level ◽  
Mitogen Activated Protein

Background: Alzheimer's Disease (AD) is associated with impairments in key brain Mitogen- Activated Protein Kinase (MAPK) signaling cascades including the p38, c-Jun N-terminal kinase (JNK), ERK and Akt pathways. Apolipoprotein E4 (ApoE4) is the most prevalent genetic risk factor of AD. Objectives: To investigate the extent to which the MAPK signaling pathway plays a role in mediating the pathological effects of apoE4 and can be reversed by experimental manipulations. Methods: Measurements of total level and activation of MAPK signaling pathway factors, obtained utilizing immunoblot assay of hippocampal tissues from naïve and viral-treated apoE3 and apoE4 targeted replacement mice. Methods: Measurements of total level and activation of MAPK signaling pathway factors, obtained utilizing immunoblot assay of hippocampal tissues from naïve and viral-treated apoE3 and apoE4 targeted replacement mice. Results: ApoE4 mice showed robust activation of the stress related p38 and JNK pathways and a corresponding decrease in Akt activity, which is coupled to activation of GSK3β and tau hyperphosphorylation. There was no effect on the ERK pathway. We have previously shown that the apoE4- related pathology, namely; accumulation of Aβ, hyper-phosphorylated tau, synaptic impairments and decreased VEGF levels can be reversed by up-regulation of VEGF level utilizing a VEGF-expressing adeno-associated virus. Utilizing this approach, we assessed the extent to which the AD-hallmark and synaptic pathologies of apoE4 are related to the corresponding MAPK signaling effects. This revealed that the reversal of the apoE4-driven pathology via VEGF treatment was associated with a reversal of the p38 and Akt related effects. Conclusion: Taken together, these results suggest that the p38 and Akt pathways play a role in mediating the AD-related pathological effects of apoE4 in the hippocampus.

scholarly journals MAPK-directed activation of the whitefly transcription factor CREB leads to P450-mediated imidacloprid resistance

2020 ◽  
Vol 117 (19) ◽  
pp. 10246-10253 ◽  
Author(s):  
Xin Yang ◽  
Shun Deng ◽  
Xuegao Wei ◽  
Jing Yang ◽  
Qiannan Zhao ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Signaling Pathway ◽  
Gene Families ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Bzip Transcription Factor ◽  
Camp Response Element ◽  
Response Element

The evolution of insect resistance to pesticides poses a continuing threat to agriculture and human health. While much is known about the proximate molecular and biochemical mechanisms that confer resistance, far less is known about the regulation of the specific genes/gene families involved, particularly by trans-acting factors such as signal-regulated transcription factors. Here we resolve in fine detail the trans-regulation of CYP6CM1, a cytochrome P450 that confers resistance to neonicotinoid insecticides in the whitefly Bemisia tabaci, by the mitogen-activated protein kinase (MAPK)-directed activation of the transcription factor cAMP-response element binding protein (CREB). Reporter gene assays were used to identify the putative promoter of CYP6CM1, but no consistent polymorphisms were observed in the promoter of a resistant strain of B. tabaci (imidacloprid-resistant, IMR), which overexpresses this gene, compared to a susceptible strain (imidacloprid-susceptible, IMS). Investigation of potential trans-acting factors using in vitro and in vivo assays demonstrated that the bZIP transcription factor CREB directly regulates CYP6CM1 expression by binding to a cAMP-response element (CRE)-like site in the promoter of this gene. CREB is overexpressed in the IMR strain, and inhibitor, luciferase, and RNA interference assays revealed that a signaling pathway of MAPKs mediates the activation of CREB, and thus the increased expression of CYP6CM1, by phosphorylation-mediated signal transduction. Collectively, these results provide mechanistic insights into the regulation of xenobiotic responses in insects and implicate both the MAPK-signaling pathway and a transcription factor in the development of pesticide resistance.

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.

Aggravation of ADAMTS and Matrix Metalloproteinase Production and Role of ERK1/2 Pathway in the Interaction of Osteoarthritic Subchondral Bone Osteoblasts and Articular Cartilage Chondrocytes — Possible Pathogenic Role in Osteoarthritis

2012 ◽  
Vol 39 (3) ◽  
pp. 621-634 ◽  
Author(s):  
INDIRA PRASADAM ◽  
ROSS CRAWFORD ◽  
YIN XIAO
Keyword(s):  
Articular Cartilage ◽  
Signaling Pathway ◽  
Subchondral Bone ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Mitogen Activated Protein ◽  
Coculture Model ◽  
Degradative Enzymes ◽  
A Disintegrin And Metalloproteinase

Objective.Degradative enzymes, such as A disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) and matrix metalloproteinases (MMP), play key roles in development of osteoarthritis (OA). We investigated if crosstalk between subchondral bone osteoblasts (SBO) and articular cartilage chondrocytes (ACC) in OA alters the expression and regulation of ADAMTS5, ADAMTS4, MMP-1, MMP-2, MMP-3, MMP-8, MMP-9, and MMP-13, and also tested the possible involvement of mitogen-activated protein kinase (MAPK) signaling pathway during this process.Methods.ACC and SBO were isolated from normal and OA patients. An in vitro coculture model was developed to study the regulation of ADAMTS and MMP under normal and OA joint crosstalk conditions. The MAPK-ERK inhibitor PD98059 was applied to delineate the involvement of specific pathways during this interaction process.Results.Indirect coculture of OA SBO with normal ACC resulted in significantly increased expression of ADAMTS5, ADAMTS4, MMP-2, MMP-3, and MMP-9 in ACC, whereas coculture of OA ACC led to increased MMP-1 and MMP-2 expression in normal SBO. Upregulation of ADAMTS and MMP under these conditions was correlated with activation of the MAPK-ERK1/2 signaling pathway, and addition of the MAPK-ERK inhibitor PD98059 reversed the overexpression of ADAMTS and MMP in cocultures.Conclusion.These results add to the evidence that in human OA, altered bidirectional signals between SBO and ACC significantly influence the critical features of both cartilage and bone by producing abnormal levels of ADAMTS and MMP. We have demonstrated for the first time that this altered crosstalk was mediated by the phosphorylation of MAPK-ERK1/2 signaling pathway.

scholarly journals MEK-inhibitor-mediated rescue of skeletal myopathy caused by activating Hras mutation in a Costello syndrome mouse model

2021 ◽  
Author(s):  
William E. Tidyman ◽  
Alice F. Goodwin ◽  
Yoshiko Maeda ◽  
Ophir D. Klein ◽  
Katherine A. Rauen
Keyword(s):  
Mouse Model ◽  
Mapk Pathway ◽  
Mek Inhibitor ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Costello Syndrome ◽  
Skeletal Myopathy ◽  
Mitogen Activated Protein

Costello syndrome (CS) is a congenital disorder caused by heterozygous activating germline HRAS mutations in the canonical Ras/mitogen-activated protein kinase (Ras/MAPK) pathway. CS is one of the RASopathies, a large group of syndromes due to mutations within various components of the Ras/MAPK pathway. An important part of the phenotype that greatly impacts quality of life is hypotonia. To gain a better understanding of the mechanisms underlying hypotonia in CS, a mouse model with an activating HrasG12V allele was utilized. We identified a skeletal myopathy that was due in part to an inhibition of embryonic myogenesis and myofiber formation, resulting in a reduction of myofiber size and number that led to reduced muscle mass and strength. In addition to hyperactivation of the Ras/MAPK and PI3K/AKT pathways, there was a significant reduction of p38 signaling, as well as global transcriptional alterations consistent with the myopathic phenotype. Inhibition of Ras/MAPK pathway signaling using a MEK inhibitor rescued the HrasG12V myopathy phenotype both in vitro and in vivo, demonstrating that increased MAPK signaling is the main cause of the muscle phenotype in CS.

scholarly journals Transcriptional Repressor ERF Is a Ras/Mitogen-Activated Protein Kinase Target That Regulates Cellular Proliferation

1999 ◽  
Vol 19 (6) ◽  
pp. 4121-4133 ◽  
Author(s):  
Lionel le Gallic ◽  
Dionyssios Sgouras ◽  
Gregory Beal ◽  
George Mavrothalassitis
Keyword(s):  
Protein Kinase ◽  
Signaling Pathway ◽  
Cellular Proliferation ◽  
Transcriptional Repressor ◽  
Mitogen Activated Protein Kinase ◽  
Ras Signaling ◽  
Mitogen Activated Protein ◽  
Ets Family

ABSTRACT A limited number of transcription factors have been suggested to be regulated directly by Erks within the Ras/mitogen-activated protein kinase signaling pathway. In this paper we demonstrate that ERF, a ubiquitously expressed transcriptional repressor that belongs to the Ets family, is physically associated with and phosphorylated in vitro and in vivo by Erks. This phosphorylation determines the ERF subcellular localization. Upon mitogenic stimulation, ERF is immediately phosphorylated and exported to the cytoplasm. The export is blocked by specific Erk inhibitors and is abolished when residues undergoing phosphorylation are mutated to alanine. Upon growth factor deprivation, ERF is rapidly dephosphorylated and transported back into the nucleus. Phosphorylation-defective ERF mutations suppress Ras-induced tumorigenicity and arrest the cells at the G0/G1 phase of the cell cycle. Our findings strongly suggest that ERF may be important in the control of cellular proliferation during the G0/G1 transition and that it may be one of the effectors in the mammalian Ras signaling pathway.

Synthesis of Baicalein Modified Cerium Oxide Nanoparticles for Inhibitory Activation of NF-κB and Mitogen-Activated Protein Kinase Signals in Rotenone-Induced Parkinsonian Rats

2020 ◽  
Vol 12 (1) ◽  
pp. 93-100 ◽  
Author(s):  
Zhuang Zhang ◽  
Meng Zhong ◽  
Jun Wang ◽  
Dongjian Xia ◽  
Jinsuo Bao
Keyword(s):  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Cytokine Release ◽  
Motor Impairments ◽  
Synthetic Procedure ◽  
Mitogen Activated Protein ◽  
Neuroprotective Efficacy ◽  
Experimental Findings

Baicalein is one of the chief flavones extracted from Scutellariabaicalensis georgi which was earlier reported for its neuroprotective efficacy against Parkinson's disease (PD). In the present study, a simple and efficient synthetic procedure for the preparation of CeO2NPs using Ce(NO3)3 as a primary precursor and baicalein as a stabilizing agent was proposed. Further, the neuroprotective response of baicalein stabilized CeO2 NPs against rotenone-stimulated parkinsonian diseased mice has been explored both in-vitro and in-vivo. From the experimental findings, it was also evident that baicalein exposure has enhanced the motor impairments, and hindered the pro-inflammatory cytokine release and blocked the NF-κB along with MAPK signaling pathway in rotenone-stimulated PD rat models.

scholarly journals In Vivo and In Vitro Study of Immunostimulation by Leuconostoc lactis-Produced Gluco-Oligosaccharides

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3994 ◽  
Author(s):  
Sulhee Lee ◽  
In Ho Song ◽  
Young-Seo Park
Keyword(s):  
In Vitro Study ◽  
Treated Group ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Raw264.7 Macrophages ◽  
Donor And Acceptor ◽  
Mitogen Activated Protein ◽  
Leuconostoc Lactis

Glycosyltransferase-producing Leuconostoc lactis CCK940 produces CCK- oligosaccharides, gluco-oligosaccharide molecules, using sucrose and maltose as donor and acceptor molecules, respectively. In this study, the immunostimulatory activities of CCK-oligosaccharides on RAW264.7 macrophages and BALB/c mice were evaluated. CCK-oligosaccharides induced the expression of phosphorylated-p38, extracellular-signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK) and upregulation of phagocytic activity in RAW264.7 macrophages, suggesting their involvement in mitogen-activated protein kinase (MAPK) signaling pathway and phagocytosis. When CCK-oligosaccharides were administered to mice intraperitoneally injected with cyclophosphamide (CY), spleen indices and expressions of interleukin (IL)-6, IL–10, and tumor necrosis factor-α increased, compared with those in only CY-treated group. These findings suggest that CCK-oligosaccharides can be used as an effective immunostimulating agent.

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