scholarly journals The Effect of IL-6-Primed Platelets on ADAMTS13-Mediated Clearance of Platelet-Bearing ULVWF and Its Mechanism

2021 ◽  
Author(s):  
Hyun-Jeong Kim ◽  
Jing-fei Dong ◽  
Yejin Song ◽  
Hyo-Il Jung ◽  
Jaewoo Song
Keyword(s):  
Complex Formation ◽  
Mek Inhibitor ◽  
Flow Chamber ◽  
Mitogen Activated Protein Kinase ◽  
Serine Threonine Kinase ◽  
Pi3k Inhibitor Ly294002 ◽  
Intracellular Signals ◽  
Microfluidic Flow ◽  
Extracellular Signal ◽  
Mitogen Activated Protein

Abstract Inflammation is an essential contributing factor in the development of thrombosis. Using a microfluidic flow chamber, we investigated how the proinflammatory cytokine interleukin 6 (IL-6) affects the cleavage of platelet-bearing ultra-large VWF (ULVWF) by plasma ADAMTS13. We found that IL-6-treated platelets perfused at arteriolar shear stress significantly enhanced the ULVWF-platelet complex formation on activated endothelial cells and suppressed their clearance by ADAMTS13 under flow conditions. We also detected the phosphorylation of the serine/threonine kinase Akt and extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) in platelets treated with IL-6. Treatment of IL-6-primed platelets with either the phosphoinositol-3 kinase (PI3K) inhibitor LY294002 or the mitogen-activated protein kinase kinase (MEK) inhibitor U0126 reduced the ULVWF-platelet complex formation and restored the clearance of the complex by plasma ADAMTS13, compared to IL-6-primed platelets. Furthermore, IL-6 enhanced the phosphorylation of the intracellular adaptor molecule 14-3-3ζ, which regulates VWF binding to the glycoprotein (GP) Ib-IX complex. The 14-3-3 antagonist R18 significantly increased ADAMTS-13 cleavage of ULVWF strings with adherent IL-6-treated platelets. These findings indicate that IL-6 related intracellular signals of platelet is involved in regulating ULVWF-platelet binding and ULVWF cleavage by ADAMTS13.

scholarly journals The p38 MAPK Components and Modulators as Biomarkers and Molecular Targets in Cancer

2021 ◽  
Vol 23 (1) ◽  
pp. 370
Author(s):  
Laura García-Hernández ◽  
María Belén García-Ortega ◽  
Gloria Ruiz-Alcalá ◽  
Esmeralda Carrillo ◽  
Juan Antonio Marchal ◽  
...  
Keyword(s):  
Molecular Targets ◽  
Mechanisms Of Action ◽  
Cellular Level ◽  
Mitogen Activated Protein Kinase ◽  
Cancer Therapies ◽  
Intracellular Signals ◽  
Extracellular Signal ◽  
Different Types ◽  
Mitogen Activated Protein ◽  
Different Tissues

The mitogen-activated protein kinase (MAPK) family is an important bridge in the transduction of extracellular and intracellular signals in different responses at the cellular level. Within this MAPK family, the p38 kinases can be found altered in various diseases, including cancer, where these kinases play a fundamental role, sometimes with antagonistic mechanisms of action, depending on several factors. In fact, this family has an immense number of functionalities, many of them yet to be discovered in terms of regulation and action in different types of cancer, being directly involved in the response to cancer therapies. To date, three main groups of MAPKs have been identified in mammals: the extracellular signal-regulated kinases (ERK), Jun N-terminal kinase (JNK), and the different isoforms of p38 (α, β, γ, δ). In this review, we highlight the mechanism of action of these kinases, taking into account their extensive regulation at the cellular level through various modifications and modulations, including a wide variety of microRNAs. We also analyze the importance of the different isoforms expressed in the different tissues and their possible role as biomarkers and molecular targets. In addition, we include the latest preclinical and clinical trials with different p38-related drugs that are ongoing with hopeful expectations in the present/future of developing precision medicine in cancer.

Regulation of polymorphonuclear leukocyte phagocytosis by myosin light chain kinase after activation of mitogen-activated protein kinase

Blood ◽  
2000 ◽  
Vol 95 (7) ◽  
pp. 2407-2412 ◽  
Author(s):  
Pamela J. Mansfield ◽  
James A. Shayman ◽  
Laurence A. Boxer
Keyword(s):  
Map Kinase ◽  
Light Chain ◽  
Polymorphonuclear Leukocyte ◽  
Myosin Light Chain Kinase ◽  
Myosin Light Chain ◽  
Mek Inhibitor ◽  
Mitogen Activated Protein Kinase ◽  
Erk Activation ◽  
Extracellular Signal ◽  
Mitogen Activated Protein

Abstract Polymorphonuclear leukocyte (PMNL) phagocytosis mediated by FcγRII proceeds in concert with activation of the mitogen-activated protein (MAP) kinase, extracellular signal-regulated kinase ERK2. We hypothesized that myosin light chain kinase (MLCK) could be phosphorylated and activated by ERK, thereby linking the MAP kinase pathway to the activation of cytoskeletal components required for pseudopod formation. To explore this potential linkage, PMNLs were challenged with antibody-coated erythrocytes (EIgG). Peak MLCK activity, 3-fold increased over controls, occurred at 4 to 6 minutes, corresponding with the peak rate of target ingestion and ERK2 activity. The MLCK inhibitor ML-7 (10 μmol/L) inhibited both phagocytosis and MLCK activity to basal values, thereby providing further support for the linkage between the functional response and the requirement for MLCK activation. The MAPK kinase (MEK) inhibitor PD098059 inhibited phagocytosis, MLCK activity, and ERK2 activity by 80% to 90%. To directly link ERK activation to MLCK activation, ERK2 was immunoprecipitated from PMNLs after EIgG ingestion. The isolated ERK2 was incubated with PMNL cytosol as a source of unactivated MLCK and with MLCK substrate; under these conditions ERK2 activated MLCK, resulting in phosphorylation of the MLCK substrate or of the myosin light chain itself. Because MLCK activates myosin, we evaluated the effect of directly inhibiting myosin adenosine triphosphatase using 2,3-butanedione monoxime (BDM) and found that phagocytosis was inhibited by more than 90% but MLCK activity remained unaffected. These results are consistent with the interpretation that MEK activates ERK, ERK2 then activates MLCK, and MLCK activates myosin. MLCK activation is a critical step in the cytoskeletal changes resulting in pseudopod formation.

scholarly journals Extracellular Signal-regulated Kinase Regulates Clathrin-independent Endosomal Trafficking

2006 ◽  
Vol 17 (2) ◽  
pp. 645-657 ◽  
Author(s):  
Sarah E. Robertson ◽  
Subba Rao Gangi Setty ◽  
Anand Sitaram ◽  
Michael S. Marks ◽  
Robert E. Lewis ◽  
...  
Keyword(s):  
Surface Expression ◽  
Mek Inhibitor ◽  
Endocytic Pathway ◽  
Mitogen Activated Protein Kinase ◽  
Erk Signaling ◽  
Endosomal Trafficking ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Kinase Suppressor Of Ras ◽  
Mitogen Activated Protein

Extracellular signal-regulated kinase (Erk) is widely recognized for its central role in cell proliferation and motility. Although previous work has shown that Erk is localized at endosomal compartments, no role for Erk in regulating endosomal trafficking has been demonstrated. Here, we report that Erk signaling regulates trafficking through the clathrin-independent, ADP-ribosylation factor 6 (Arf6) GTPase-regulated endosomal pathway. Inactivation of Erk induced by a variety of methods leads to a dramatic expansion of the Arf6 endosomal recycling compartment, and intracellular accumulation of cargo, such as class I major histocompatibility complex, within the expanded endosome. Treatment of cells with the mitogen-activated protein kinase kinase (MEK) inhibitor U0126 reduces surface expression of MHCI without affecting its rate of endocytosis, suggesting that inactivation of Erk perturbs recycling. Furthermore, under conditions where Erk activity is inhibited, a large cohort of Erk, MEK, and the Erk scaffold kinase suppressor of Ras 1 accumulates at the Arf6 recycling compartment. The requirement for Erk was highly specific for this endocytic pathway, because its inhibition had no effect on trafficking of cargo of the classical clathrin-dependent pathway. These studies reveal a previously unappreciated link of Erk signaling to organelle dynamics and endosomal trafficking.

scholarly journals RAF/MEK/extracellular signal–related kinase pathway suppresses dendritic cell migration and traps dendritic cells in Langerhans cell histiocytosis lesions

2017 ◽  
Vol 215 (1) ◽  
pp. 319-336 ◽  
Author(s):  
Brandon Hogstad ◽  
Marie-Luise Berres ◽  
Rikhia Chakraborty ◽  
Jun Tang ◽  
Camille Bigenwald ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Langerhans Cell Histiocytosis ◽  
Mapk Pathway ◽  
Mek Inhibitor ◽  
Langerhans Cell ◽  
Mitogen Activated Protein Kinase ◽  
Phagocytic Cells ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Myeloid Neoplasia

Langerhans cell histiocytosis (LCH) is an inflammatory myeloid neoplasia characterized by granulomatous lesions containing pathological CD207+ dendritic cells (DCs) with constitutively activated mitogen-activated protein kinase (MAPK) pathway signaling. Approximately 60% of LCH patients harbor somatic BRAFV600E mutations localizing to CD207+ DCs within lesions. However, the mechanisms driving BRAFV600E+ LCH cell accumulation in lesions remain unknown. Here we show that sustained extracellular signal–related kinase activity induced by BRAFV600E inhibits C-C motif chemokine receptor 7 (CCR7)–mediated DC migration, trapping DCs in tissue lesions. Additionally, BRAFV600E increases expression of BCL2-like protein 1 (BCL2L1) in DCs, resulting in resistance to apoptosis. Pharmacological MAPK inhibition restores migration and apoptosis potential in a mouse LCH model, as well as in primary human LCH cells. We also demonstrate that MEK inhibitor-loaded nanoparticles have the capacity to concentrate drug delivery to phagocytic cells, significantly reducing off-target toxicity. Collectively, our results indicate that MAPK tightly suppresses DC migration and augments DC survival, rendering DCs in LCH lesions trapped and resistant to cell death.

scholarly journals Extreme Outlier Analysis Identifies Occult Mitogen-Activated Protein Kinase Pathway Mutations in Patients With Low-Grade Serous Ovarian Cancer

2015 ◽  
Vol 33 (34) ◽  
pp. 4099-4105 ◽  
Author(s):  
Rachel N. Grisham ◽  
Brooke E. Sylvester ◽  
Helen Won ◽  
Gregory McDermott ◽  
Deborah DeLair ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Functional Characterization ◽  
Mek Inhibitor ◽  
Mitogen Activated Protein Kinase ◽  
Low Grade ◽  
Outlier Analysis ◽  
Pathway Activation ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Kinase Pathway

Purpose No effective systemic therapy exists for patients with metastatic low-grade serous (LGS) ovarian cancers. BRAF and KRAS mutations are common in serous borderline (SB) and LGS ovarian cancers, and MEK inhibition has been shown to induce tumor regression in a minority of patients; however, no correlation has been observed between mutation status and clinical response. With the goal of identifying biomarkers of sensitivity to MEK inhibitor treatment, we performed an outlier analysis of a patient who experienced a complete, durable, and ongoing (> 5 years) response to selumetinib, a non-ATP competitive MEK inhibitor. Patients and Methods Next-generation sequencing was used to analyze this patient's tumor as well as an additional 28 SB/LGS tumors. Functional characterization of an identified novel alteration of interest was performed. Results Analysis of the extraordinary responder's tumor identified a 15-nucleotide deletion in the negative regulatory helix of the MAP2K1 gene encoding for MEK1. Functional characterization demonstrated that this mutant induced extracellular signal-regulated kinase pathway activation, promoted anchorage-independent growth and tumor formation in mice, and retained sensitivity to selumetinib. Analysis of additional LGS/SB tumors identified mutations predicted to induce extracellular signal-regulated kinase pathway activation in 82% (23 of 28), including two patients with BRAF fusions, one of whom achieved an ongoing complete response to MEK inhibitor–based combination therapy. Conclusion Alterations affecting the mitogen-activated protein kinase pathway are present in the majority of patients with LGS ovarian cancer. Next-generation sequencing analysis revealed deletions and fusions that are not detected by older sequencing approaches. These findings, coupled with the observation that a subset of patients with recurrent LGS ovarian cancer experienced dramatic and durable responses to MEK inhibitor therapy, support additional clinical studies of MEK inhibitors in this disease.

Thrombopoietin-Induced Activation of the Mitogen-Activated Protein Kinase (MAPK) Pathway in Normal Megakaryocytes: Role in Endomitosis

Blood ◽  
1999 ◽  
Vol 94 (4) ◽  
pp. 1273-1282 ◽  
Author(s):  
Ponlapat Rojnuckarin ◽  
Jonathan G. Drachman ◽  
Kenneth Kaushansky
Keyword(s):  
Protein Kinase ◽  
Mapk Pathway ◽  
Geometric Mean ◽  
Critical Role ◽  
Mek Inhibitor ◽  
Mitogen Activated Protein Kinase ◽  
Mapk Activity ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Signaling Domain

Thrombopoietin (TPO) plays a critical role in megakaryocyte proliferation and differentiation. Using various cultured cell lines, several recent studies have implicated the mitogen-activated protein kinase (MAPK) pathway in megakaryocyte differentiation. In the study reported here, we examined the role played by thrombopoietin-induced MAPK activity in a cytokine-dependent cell line (BAF3/Mpl) and in primary murine megakaryocytes. In both systems, extracellular signal-regulated protein kinase (ERK) 1 and 2 MAPK phosphorylation was rapidly induced by TPO stimulation. To identify the Mpl domain responsible for MAPK activation, BAF3 cells expressing truncated forms of the Mpl receptor were studied. Phosphorylation of ERKs did not require elements of the cytoplasmic signaling domain distal to Box 2 and was not dependent on phosphorylation of the adapter protein Shc. ERK activation in murine megakaryocytes was maximal at 10 minutes and was markedly decreased over the subsequent 3 hours. Next, the physiologic consequences of MAPK inhibition were studied. Using the MAPK kinase (MEK) inhibitor, PD 98059, blockade of MAPK activity substantially reduced TPO-dependent proliferation in BAF3/Mpl cells and markedly decreased mean megakaryocyte ploidy in cultures. To exclude an indirect effect of MAPK inhibition on stromal cells in whole bone marrow, CD41+ cells were selected and then cultured in TPO. The number of polyploid megakaryocytes derived from the CD41-selected cells was also significantly reduced by MEK inhibition, as was their geometric mean ploidy. These studies show an important role for MAPK in TPO-induced endomitosis and underscore the value of primary cells when studying the physiologic effects of signaling pathways.

Thrombopoietin-Induced Activation of the Mitogen-Activated Protein Kinase (MAPK) Pathway in Normal Megakaryocytes: Role in Endomitosis

Blood ◽  
1999 ◽  
Vol 94 (4) ◽  
pp. 1273-1282 ◽  
Author(s):  
Ponlapat Rojnuckarin ◽  
Jonathan G. Drachman ◽  
Kenneth Kaushansky
Keyword(s):  
Protein Kinase ◽  
Mapk Pathway ◽  
Geometric Mean ◽  
Critical Role ◽  
Mek Inhibitor ◽  
Mitogen Activated Protein Kinase ◽  
Mapk Activity ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Signaling Domain

Abstract Thrombopoietin (TPO) plays a critical role in megakaryocyte proliferation and differentiation. Using various cultured cell lines, several recent studies have implicated the mitogen-activated protein kinase (MAPK) pathway in megakaryocyte differentiation. In the study reported here, we examined the role played by thrombopoietin-induced MAPK activity in a cytokine-dependent cell line (BAF3/Mpl) and in primary murine megakaryocytes. In both systems, extracellular signal-regulated protein kinase (ERK) 1 and 2 MAPK phosphorylation was rapidly induced by TPO stimulation. To identify the Mpl domain responsible for MAPK activation, BAF3 cells expressing truncated forms of the Mpl receptor were studied. Phosphorylation of ERKs did not require elements of the cytoplasmic signaling domain distal to Box 2 and was not dependent on phosphorylation of the adapter protein Shc. ERK activation in murine megakaryocytes was maximal at 10 minutes and was markedly decreased over the subsequent 3 hours. Next, the physiologic consequences of MAPK inhibition were studied. Using the MAPK kinase (MEK) inhibitor, PD 98059, blockade of MAPK activity substantially reduced TPO-dependent proliferation in BAF3/Mpl cells and markedly decreased mean megakaryocyte ploidy in cultures. To exclude an indirect effect of MAPK inhibition on stromal cells in whole bone marrow, CD41+ cells were selected and then cultured in TPO. The number of polyploid megakaryocytes derived from the CD41-selected cells was also significantly reduced by MEK inhibition, as was their geometric mean ploidy. These studies show an important role for MAPK in TPO-induced endomitosis and underscore the value of primary cells when studying the physiologic effects of signaling pathways.

scholarly journals Nucleoside Transport Inhibition by Dipyridamole Prevents Angiogenesis Impairment by Homocysteine and Adenosine

2015 ◽  
Vol 18 (5) ◽  
pp. 871 ◽  
Author(s):  
Antony Kam ◽  
Valentina Razmovski-Naumovski ◽  
Xian Zhou ◽  
John Troung ◽  
Kelvin Chan
Keyword(s):  
Vascular Complications ◽  
Mek Inhibitor ◽  
Mitogen Activated Protein Kinase ◽  
Nucleoside Transport ◽  
Mechanism Analysis ◽  
Extracellular Adenosine ◽  
Transport Inhibition ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Protein Kinase Kinase

Purpose: Adenosine plays an important role in the pathogenesis of homocysteine-associated vascular complications. Methods: This study examined the effects of dipyridamole, an inhibitor for nucleoside transport, on impaired angiogenic processes caused by homocysteine and adenosine in human cardiovascular endothelial cell line (EAhy926). Results: The results showed that dipyridamole restored the extracellular adenosine and intracellular S-adenosylhomocysteine concentrations disrupted by the combination of homocysteine and adenosine. Dipyridamole also ameliorated the impaired proliferation, migration and formation of capillary-like tubes of EAhy926 cells caused by the combination of homocysteine and adenosine. Mechanism analysis revealed that dipyridamole induced the phosphorylation of mitogen-activated protein kinase kinase (MEK) and extracellular signal-regulated kinases (ERK) and its effect on cell growth was attenuated by the MEK inhibitor, U0126. Conclusion: Dipyridamole protected against impaired angiogenesis caused by homocysteine and adenosine, at least in part, by activating the MEK/ERK signalling pathway, and this could be associated with its effects in suppressing intracellular S-adenosylhomocysteine accumulation.Novelty of the Work: This is the first paper showing that nucleoside transport inhibition by dipyridamole reduced impaired angiogenic process caused by homocysteine and adenosine.This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.

scholarly journals Role of phosphoinositide 3-kinase and the Cbl adaptor protein in coupling the α4β1 integrin to mitogen-activated protein kinase signalling

2000 ◽  
Vol 345 (2) ◽  
pp. 385-392 ◽  
Author(s):  
Lisa D. FINKELSTEIN ◽  
Yoji SHIMIZU
Keyword(s):  
Protein Kinase ◽  
Adaptor Protein ◽  
Dominant Negative ◽  
Mitogen Activated Protein Kinase ◽  
Hl60 Cells ◽  
Intracellular Signals ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Phosphoinositide 3 Kinase ◽  
Stimulation Of

Cell adhesion mediated by β1 integrin receptors leads to the initiation of intracellular signals that affect cell differentiation and survival. Here we have analysed the mechanism by which the α4β1 integrin activates the mitogen-activated protein kinase pathway in HL60 cells, a myelomonocytic cell line that lacks the expression of focal adhesion kinase. A role for phosphoinositide 3-kinase (PI-3K) in α4 integrin-mediated activation of extracellular signal-regulated protein kinase 2 (ERK2) is suggested by the ability of PI-3K inhibitors and a dominant-negative form of the p85 subunit of PI-3K to block the activation of ERK2 by integrin. Stimulation of α4β1 integrins on HL60 cells also leads to increased tyrosine phosphorylation of the 120 kDa adaptor protein Cbl. PI-3K activity associated with Cbl also increases on the stimulation of α4β1 integrins, although immunodepletion experiments suggest that Cbl-associated PI-3K does not account for all of the PI-3K activity induced on the stimulation of integrins in these cells. The expression of wild-type Cbl or the 70Z/3 Cbl mutant enhances basal ERK2 activity in transfectants with a minimal effect on α4 integrin-mediated ERK2 activity. In contrast, overexpression of the Hut Cbl truncation mutant, which does not associate with p85, has no effect on the ERK2 pathway. These results suggest that PI-3K has a major role in coupling α4β1 integrins to ERK2 activation in myeloid cells and that the Cbl adaptor protein has a role in basal, but not α4β1 integrin-mediated, activation of ERK2.

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