Erk1/2- and p38 MAP kinase-dependent phosphorylation and activation of cPLA2by m3 and m2 receptors

2003 ◽  
Vol 284 (3) ◽  
pp. G472-G480 ◽  
Author(s):  
Huiping Zhou ◽  
Sankar Das ◽  
Karnam S. Murthy
Keyword(s):  
Map Kinase ◽  
Kinase Inhibitor ◽  
P38 Map Kinase ◽  
Dominant Negative ◽  
Cytosolic Phospholipase ◽  
M3 Receptors ◽  
Protein Map ◽  
Mitogen Activated Protein ◽  
Sequential Activation ◽  
P21 Activated Kinase

This study examined the upstream signaling pathways initiated by muscarinic m2 and m3 receptors that mediate sustained ERK1/2- and p38 MAP kinase-dependent phosphorylation and activation of the 85-kDa cytosolic phospholipase (cPL)A2in smooth muscle. The pathway initiated by m2 receptors involved sequential activation of Gβγi3, phosphatidylinositol (PI)3-kinase, Cdc42, and Rac1, p21-activated kinase (PAK1), p38 mitogen-activated protein (MAP) kinase, and cPLA2, and phosphorylation of cPLA2at Ser505. cPLA2activity was inhibited to the same extent (61 ± 5 to 72 ± 4%) by the m2 antagonist methoctramine, Gβ antibody, pertussis toxin, the PI3-kinase inhibitor LY 294002, PAK1 antibody, the p38 MAP kinase inhibitor SB-203580, and a Cdc42/Rac1 GEF (Vav2) antibody and by coexpression of dominant-negative Cdc42 and Rac1 mutants. The pathway initiated by m3 receptors involved sequential activation of Gαq, PLC-β1, PKC, ERK1/2, and cPLA2, and phosphorylation of cPLA2at Ser505. cPLA2activity was inhibited to the same extent (35 ± 3 to 41 ± 5%) by the m3 antagonist 4-diphenylacetoxy- N-methylpiperdine (4-DAMP), the phosphoinositide hydrolysis inhibitor U-73122, the PKC inhibitor bisindolylmaleimide, and the ERK1/2 inhibitor PD 98059. cPLA2activity was not affected in cells coexpressing dominant-negative RhoA and PLC-δ1 mutants, implying that PKC was not derived from phosphatidylcholine hydrolysis. The effects of ERK1/2 and p38 MAP kinase on cPLA2activity were additive and accounted fully for activation and phosphorylation of cPLA2.

scholarly journals Oxidation-triggered c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein (MAP) kinase pathways for apoptosis in human leukaemic cells stimulated by epigallocatechin-3-gallate (EGCG): a distinct pathway from those of chemically induced and receptor-mediated apoptosis

2002 ◽  
Vol 368 (3) ◽  
pp. 705-720 ◽  
Author(s):  
Koichi SAEKI ◽  
Norihiko KOBAYASHI ◽  
Yuko INAZAWA ◽  
Hong ZHANG ◽  
Hideki NISHITOH ◽  
...  
Keyword(s):  
Cell Death ◽  
Map Kinase ◽  
Map Kinases ◽  
Specific Inhibitor ◽  
P38 Map Kinase ◽  
Dominant Negative ◽  
Chemically Induced ◽  
Protein Map ◽  
Mitogen Activated Protein ◽  
Induced Apoptosis

We investigated intracellular signalling pathways for apoptosis induced by epigallocatechin-3-gallate (EGCG) as compared with those induced by a toxic chemical substance (etoposide, VP16) or the death receptor ligand [tumour necrosis factor (TNF)]. EGCG as well as VP16 and TNF induced activation of two apoptosis-regulating mitogen-activated protein (MAP) kinases, namely c-Jun N-terminal kinase (JNK) and p38 MAP kinase, in both human leukaemic U937 and OCI-AML1a cells. In U937 cells, the apoptosis and activation of caspases-3 and −9 induced by EGCG but not VP16 and TNF were inhibited with SB203580, a specific inhibitor of p38, while those induced by EGCG and VP16 but not TNF were inhibited with SB202190, a rather broad inhibitor of JNK and p38. In contrast, the EGCG-induced apoptosis in OCI-AML1a cells was resistant to SB203580 but not to SB202190. Unlike TNF, EGCG did not induce the activation of nuclear factor-κB but rather induced the primary activation of caspase-9. N-Acetyl-l-cysteine (NAC) almost completely abolished apoptosis induced by EGCG under conditions in which the apoptosis induced by VP16 or TNF was not affected. The JNK/p38 activation by EGCG was also potently inhibited by NAC, whereas those by VP16 and TNF were either not or only minimally affected by NAC. In addition, dithiothreitol also suppressed both apoptosis and JNK/p38 activation by EGCG, and EGCG-induced activation of MAP kinase kinase (MKK) 3/6, MKK4 and apoptosis-regulating kinase 1 (ASK1) was suppressed by NAC. Dominant negative ASK1, MKK6, MKK4 and JNK1 potently inhibited EGCG-induced cell death. EGCG induced an intracellular increase in reactive oxygen species and GSSG, both of which were also inhibited by NAC, and the decreased synthesis of glutathione rendered the cell susceptible to EGCG-induced apoptosis. Taken together these results strongly suggest that EGCG executed apoptotic cell death via an ASK1, MKK and JNK/p38 cascade which is triggered by NAC-sensitive intracellular oxidative events in a manner distinct from chemically induced or receptor-mediated apoptosis.

Evidence for the role of p38 MAP kinase in hypoxia-induced pulmonary vasoconstriction

2002 ◽  
Vol 283 (4) ◽  
pp. L859-L866 ◽  
Author(s):  
M. R. Karamsetty ◽  
J. R. Klinger ◽  
N. S. Hill
Keyword(s):  
Map Kinase ◽  
Map Kinases ◽  
Kinase Inhibitor ◽  
Acute Hypoxia ◽  
Pulmonary Arteries ◽  
P38 Map Kinase ◽  
Pulmonary Vasoconstriction ◽  
Protein Map ◽  
Mitogen Activated Protein

Mitogen-activated protein (MAP) kinases regulate smooth muscle cell contraction. Hypoxia contracts pulmonary arteries by mechanisms that are incompletely understood. We hypothesized that hypoxic contraction of pulmonary arteries involves activation of the MAP kinases. To test this hypothesis, we studied the effects of SB-202190, a p38 MAP kinase inhibitor, PD-98059 and UO-126, two structurally different MEKK inhibitors, and anisomycin, a stimulator of p38 MAP kinase on acute hypoxia-induced contraction in rat conduit pulmonary artery rings precontracted with phenylephrine or KCl. Hypoxia induced a transient contraction, followed by a relaxation, and then a slowly developing sustained contraction. Hypoxia also significantly increased phosphorylation of p38 MAP kinase. SB-202190 did not affect the transient phase but abrogated the sustained phase of hypoxic contraction, whereas anisomycin enhanced both phases of contraction. SB-202190 also attenuated and anisomycin enhanced the phenylephrine-induced contraction. In contrast, PD-98059 and UO-126 had minimal effects on either hypoxic or phenylephrine-induced contraction. None of the treatments modified KCl-induced contraction. We conclude that p38, but not the ERK1/ERK2 MAP kinase pathway, mediates the sustained phase of hypoxic contraction in isolated rat pulmonary arteries.

ERK and p38 MAP kinase are involved in arachidonic acid release induced by H2O2 and PDGF in mesangial cells

2002 ◽  
Vol 282 (3) ◽  
pp. F485-F491 ◽  
Author(s):  
Misako Hayama ◽  
Risa Inoue ◽  
Satoshi Akiba ◽  
Takashi Sato
Keyword(s):  
Arachidonic Acid ◽  
Map Kinase ◽  
Mesangial Cells ◽  
P38 Map Kinase ◽  
Arachidonic Acid Release ◽  
Cytosolic Phospholipase ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Acid Release ◽  
Map Kinase Pathways

Increased prostaglandin production is implicated in the pathogenesis of glomerular disease. With this consideration, we examined the combined effects of reactive oxygen species and platelet-derived growth factor (PDGF), which might initiate glomerular dysfunction, on arachidonic acid release and cytosolic phospholipase A2 (cPLA2) activation in rat mesangial cells. H2O2-induced release of arachidonic acid was enhanced by PDGF, which by itself had little effect on the release, and the enhancement was completely inhibited by a cPLA2 inhibitor. The phosphorylation of cPLA2, extracellular signal-regulated kinase (ERK), and p38 mitogen-activated protein (MAP) kinase was upregulated by H2O2 or PDGF alone and except for ERK was enhanced further by the two in combination. The release of arachidonic acid induced by PDGF together with H2O2 was inhibited partially by an inhibitor of ERK or p38 MAP kinase and completely when the two inhibitors were combined; the inhibitory pattern was similar to that for the phosphorylation of cPLA2. These results suggest that the ERK and p38 MAP kinase pathways are involved in the increase in cPLA2activation and arachidonic acid release induced by PDGF together with H2O2.

Incretins Enhance PGF2α-Induced Synthesis of IL-6 and Osteoprotegerin in Osteoblasts

2022 ◽  
Vol 54 (01) ◽  
pp. 42-49
Author(s):  
Tomoyuki Hioki ◽  
Gen Kuroyanagi ◽  
Kazuhiko Fujita ◽  
Go Sakai ◽  
Tetsu Kawabata ◽  
...  
Keyword(s):  
Map Kinase ◽  
Prostaglandin F2α ◽  
P38 Map Kinase ◽  
Β Cells ◽  
Kinase C ◽  
Protein Map ◽  
Mitogen Activated Protein ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1

AbstractIncretins including glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), which are secreted from the small intestine after oral food ingestion, are currently well-known to stimulate insulin secretion from pancreatic β-cells and used for the treatment of type 2 diabetes mellitus. We have previously reported that prostaglandin F2α (PGF2α) stimulates the synthesis of interleukin-6 (IL-6) and osteoprotegerin in osteoblast-like MC3T3-E1 cells, and that IL-6 and osteoprotegerin release are mediated through the p44/p42 mitogen-activated protein (MAP) kinase, p38 MAP kinase or stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK) pathways. In the present study, we investigated the effects of incretins including GLP-1 and GIP, on the PGF2α-induced synthesis of IL-6 and osteoprotegerin and examined the detailed mechanism in osteoblast-like MC3T3-E1 cells. We found that GIP and GLP-1 significantly stimulated the PGF2α-induced synthesis of IL-6 in osteoblast-like MC3T3-E1 cells. In addition, GIP and GLP-1 significantly enhanced the PGF2α-induced mRNA expression levels of IL-6. On the other hand, GIP and GLP-1 markedly stimulated the PGF2α-induced synthesis of osteoprotegerin. However, the phosphorylation of p44/p42 MAP kinase, p38 MAP kinase, or JNK induced by PGF2α was not affected by GIP or GLP-1. Therefore, these results strongly suggest that incretins enhance the PGF2α-induced synthesis of IL-6 and osteoprotegerin in osteoblast-like MC3T3-E1 cells. However, these syntheses are not mediated through p44/p42 MAP kinase, p38 MAP kinase, or JNK pathways.

scholarly journals Triggering of Suicidal Erythrocyte Death by Ruxolitinib

2015 ◽  
Vol 37 (2) ◽  
pp. 768-778 ◽  
Author(s):  
Marilena Briglia ◽  
Antonella Fazio ◽  
Caterina Faggio ◽  
Stefan Laufer ◽  
Kousi Alzoubi ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Map Kinase ◽  
Kinase Inhibitor ◽  
Myeloproliferative Neoplasm ◽  
Annexin V ◽  
P38 Map Kinase ◽  
Cell Shrinkage ◽  
Forward Scatter ◽  
Mitogen Activated Protein ◽  
Suicidal Death

Background/Aims: The JAK1/JAK2 tyrosine kinase inhibitor ruxolitinib is widely used for the treatment of myeloproliferative neoplasm-associated myelofibrosis and other malignancies. Most important side effects include anemia. A common cause of anemia is accelerated suicidal death of erythrocytes or eryptosis, which is characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. Mechanisms contributing to the triggering of eryptosis include oxidative stress, Ca2+ entry with increase of cytosolic Ca2+ activity ([Ca2+]i), and activation of distinct kinases, such as p38 mitogen activated protein (MAP) kinase. The present study explored whether and how ruxolitinib induces eryptosis. Methods: Phosphatidylserine exposure at the cell surface was estimated from annexin-V-binding, cell volume from forward scatter, hemolysis from hemoglobin release, [Ca2+]i from Fluo3-fluorescence, and ROS formation from DCFDA dependent fluorescence. Results: A 48 hours exposure of human erythrocytes to ruxolitinib (25 µM) significantly increased the percentage of annexin-V-binding cells and significantly decreased forward scatter. Ruxolitinib did not significantly modify Fluo3-fluorescence and DCFDA fluorescence and the effect of ruxolitinib on annexin-V-binding was not significantly modified by removal of extracellular Ca2+. The effect of ruxolitinib on annexin-V-binding was, however, significantly blunted by the p38 MAP kinase inhibitor SB203580 and virtually abolished by the p38 MAP kinase inhibitor skepinone. Conclusion: Ruxolitinib triggers cell shrinkage and phospholipid scrambling of the erythrocyte cell membrane, an effect in part requiring p38 MAP kinase activity.

scholarly journals Shc and Fak Differentially Regulate Cell Motility and Directionality Modulated by Pten

1999 ◽  
Vol 146 (2) ◽  
pp. 389-404 ◽  
Author(s):  
Jianguo Gu ◽  
Masahito Tamura ◽  
Roumen Pankov ◽  
Erik H.J. Danen ◽  
Takahisa Takino ◽  
...  
Keyword(s):  
Cell Migration ◽  
Tumor Suppressor ◽  
Cell Motility ◽  
Map Kinase ◽  
Focal Adhesion ◽  
Focal Adhesions ◽  
Dominant Negative ◽  
Kinase Activation ◽  
Protein Map ◽  
Mitogen Activated Protein

Cell migration is modulated by regulatory molecules such as growth factors, oncogenes, and the tumor suppressor PTEN. We previously described inhibition of cell migration by PTEN and restoration of motility by focal adhesion kinase (FAK) and p130 Crk-associated substrate (p130Cas). We now report a novel pathway regulating random cell motility involving Shc and mitogen-activated protein (MAP) kinase, which is downmodulated by PTEN and additive to a FAK pathway regulating directional migration. Overexpression of Shc or constitutively activated MEK1 in PTEN- reconstituted U87-MG cells stimulated integrin- mediated MAP kinase activation and cell migration. Conversely, overexpression of dominant negative Shc inhibited cell migration; Akt appeared uninvolved. PTEN directly dephosphorylated Shc. The migration induced by FAK or p130Cas was directionally persistent and involved extensive organization of actin microfilaments and focal adhesions. In contrast, Shc or MEK1 induced a random type of motility associated with less actin cytoskeletal and focal adhesion organization. These results identify two distinct, additive pathways regulating cell migration that are downregulated by tumor suppressor PTEN: one involves Shc, a MAP kinase pathway, and random migration, whereas the other involves FAK, p130Cas, more extensive actin cytoskeletal organization, focal contacts, and directionally persistent cell motility. Integration of these pathways provides an intracellular mechanism for regulating the speed and the directionality of cell migration.

scholarly journals p38 mitogen-activated protein (MAP) kinase but not p44/p42 MAP kinase is involved in prostaglandin E1-induced vascular endothelial growth factor synthesis in osteoblasts

2001 ◽  
Vol 170 (3) ◽  
pp. 629-638 ◽  
Author(s):  
H Tokuda ◽  
O Kozawa ◽  
M Miwa ◽  
T Uematsu
Keyword(s):  
Map Kinase ◽  
Cholera Toxin ◽  
Prostaglandin E1 ◽  
Specific Inhibitor ◽  
P38 Map Kinase ◽  
Vascular Endothelial ◽  
Kinase Activation ◽  
Protein Map ◽  
Mitogen Activated Protein ◽  
Endothelial Growth Factor

We investigated the mechanism underlying vascular endothelial growth factor (VEGF) synthesis stimulated by prostaglandin E1 (PGE1) in osteoblast-like MC3T3-E1 cells. PGE1 induced the phosphorylation of both p44/p42 mitogen-activated protein (MAP) kinase and p38 MAP kinase. SB203580, a specific inhibitor of p38 MAP kinase, inhibited the PGE1-stimulated VEGF synthesis as well as PGE1-induced phosphorylation of p38 MAP kinase. PD98059, an inhibitor of the upstream kinase that activates p44/p42 MAP kinase, which reduced the PGE1-induced phosphorylation of p44/p42 MAP kinase, had little effect on the VEGF synthesis stimulated by PGE1. AH-6809, an antagonist of the subtypes of the PGE receptor, EP1 and EP2, or SC-19220, an antagonist of EP1 receptor, did not inhibit the PGE1-induced VEGF synthesis. H-89, an inhibitor of cAMP-dependent protein kinase, and SQ22536, an inhibitor of adenylate cyclase, reduced the VEGF synthesis induced by PGE1. Cholera toxin, an activator of G(s), and forskolin, an activator of adenylate cyclase, induced VEGF synthesis. SB203580 and PD169316, another specific inhibitor of p38 MAP kinase, reduced the cholera toxin-, forskolin- or 8bromo-cAMP-stimulated VEGF synthesis. However, PD98059 failed to affect the VEGF synthesis stimulated by cholera toxin, forskolin or 8-bromoadenosine-3',5'-cyclic monophosphate (8bromo-cAMP). SB203580 reduced the phosphorylation of p38 MAP kinase induced by forskolin or 8bromo-cAMP. These results strongly suggest that p44/p42 MAP kinase activation is not involved in the PGE1-stimulated VEGF synthesis in osteoblasts but that p38 MAP kinase activation is involved.

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