Dexamethasone Causes Sustained Expression of Mitogen-Activated Protein Kinase (MAPK) Phosphatase 1 and Phosphatase-Mediated Inhibition of MAPK p38

ABSTRACT The stress-activated protein kinase p38 stabilizes a number of mRNAs encoding inflammatory mediators, such as cyclooxygenase 2 (Cox-2). In HeLa cells the anti-inflammatory glucocorticoid dexamethasone destabilizes Cox-2 mRNA by inhibiting p38 function. Here we demonstrate that this effect is phosphatase dependent. Furthermore, in HeLa cells dexamethasone induced the sustained expression of mitogen-activated protein kinase phosphatase 1 (MKP-1), a potent inhibitor of p38 function. The inhibition of p38 and the induction of MKP-1 by dexamethasone occurred with similar dose dependence and kinetics. No other known p38 phosphatases were induced by dexamethasone, and other cell types which failed to express MKP-1 also failed to inhibit p38 in response to dexamethasone. The proinflammatory cytokine interleukin 1 (IL-1) induced MKP-1 expression in a p38-dependent manner and acted synergistically with dexamethasone to induce MKP-1 expression. In HeLa cells treated with IL-1 or IL-1 and dexamethasone, the dynamics of p38 activation mirrored the expression of MKP-1. These observations suggest that MKP-1 participates in a negative-feedback loop which regulates p38 function and that dexamethasone may inhibit proinflammatory gene expression in part by inducing MKP-1 expression.

Download Full-text

Dexamethasone Destabilizes Cyclooxygenase 2 mRNA by Inhibiting Mitogen-Activated Protein Kinase p38

Molecular and Cellular Biology ◽

10.1128/mcb.21.3.771-780.2001 ◽

2001 ◽

Vol 21 (3) ◽

pp. 771-780 ◽

Cited By ~ 166

Author(s):

Marina Lasa ◽

Matthew Brook ◽

Jeremy Saklatvala ◽

Andrew R. Clark

Keyword(s):

Protein Kinase ◽

Actinomycin D ◽

Cell Types ◽

Cyclooxygenase 2 ◽

Mitogen Activated Protein Kinase ◽

Reporter System ◽

Mitogen Activated Protein ◽

Cox 2 ◽

The Stability ◽

Reporter Mrna

ABSTRACT The stability of cyclooxygenase 2 (Cox-2) mRNA is regulated positively by proinflammatory stimuli acting through mitogen-activated protein kinase (MAPK) p38 and negatively by anti-inflammatory glucocorticoids such as dexamethasone. A tetracycline-regulated reporter system was used to investigate mechanisms of regulation of Cox-2 mRNA stability. Dexamethasone was found to destabilize β-globin–Cox-2 reporter mRNAs by inhibiting p38. This inhibition occurred at the level of p38 itself: stabilization of reporter mRNA by a kinase upstream of p38 was blocked by dexamethasone, while stabilization by a kinase downstream of p38 was insensitive to dexamethasone. Inhibition of p38 activity by dexamethasone was observed in a variety of cell types treated with different activating stimuli. Furthermore, inhibition of p38 was antagonized by the anti-glucocorticoid RU486 and was delayed and actinomycin D sensitive, suggesting that ongoing glucocorticoid receptor-dependent transcription is required.

Download Full-text

Topical Spilanthol Inhibits MAPK Signaling and Ameliorates Allergic Inflammation in DNCB-Induced Atopic Dermatitis in Mice

International Journal of Molecular Sciences ◽

10.3390/ijms20102490 ◽

2019 ◽

Vol 20 (10) ◽

pp. 2490 ◽

Cited By ~ 4

Author(s):

Wen-Chung Huang ◽

Chun-Hsun Huang ◽

Sindy Hu ◽

Hui-Ling Peng ◽

Shu-Ju Wu

Keyword(s):

Atopic Dermatitis ◽

Mast Cells ◽

Protein Kinase ◽

Allergic Inflammation ◽

Skin Lesions ◽

Mapk Signaling ◽

Mitogen Activated Protein Kinase ◽

Mapk Pathways ◽

Mitogen Activated Protein ◽

Cox 2

Atopic dermatitis (AD) is a recurrent allergic skin disease caused by genetic and environmental factors. Patients with AD may experience immune imbalance, increased levels of mast cells, immunoglobulin (Ig) E and pro-inflammatory factors (Cyclooxygenase, COX-2 and inducible NO synthase, iNOS). While spilanthol (SP) has anti-inflammatory and analgesic activities, its effect on AD remains to be explored. To develop a new means of SP, inflammation-related symptoms of AD were alleviated, and 2,4-dinitrochlorobenzene (DNCB) was used to induce AD-like skin lesions in BALB/c mice. Histopathological analysis was used to examine mast cells and eosinophils infiltration in AD-like skin lesions. The levels of IgE, IgG1 and IgG2a were measured by enzyme-linked immunosorbent assay (ELISA) kits. Western blot was used for analysis of the mitogen-activated protein kinase (MAPK) pathways and COX-2 and iNOS protein expression. Topical SP treatment reduced serum IgE and IgG2a levels and suppressed COX-2 and iNOS expression via blocked mitogen-activated protein kinase (MAPK) pathways in DNCB-induced AD-like lesions. Histopathological examination revealed that SP reduced epidermal thickness and collagen accumulation and inhibited mast cells and eosinophils infiltration into the AD-like lesions skin. These results indicate that SP may protect against AD skin lesions through inhibited MAPK signaling pathways and may diminish the infiltration of inflammatory cells to block allergic inflammation.

Download Full-text

Cross-talk between IRAK-4 and the NADPH oxidase1

Biochemical Journal ◽

10.1042/bj20061184 ◽

2007 ◽

Vol 403 (3) ◽

pp. 451-461 ◽

Cited By ~ 50

Author(s):

Sandrine Pacquelet ◽

Jennifer L. Johnson ◽

Beverly A. Ellis ◽

Agnieszka A. Brzezinska ◽

William S. Lane ◽

...

Keyword(s):

Protein Kinase ◽

Nadph Oxidase ◽

P38 Mapk ◽

Interleukin 1 ◽

Mitogen Activated Protein Kinase ◽

Free System ◽

Mitogen Activated Protein ◽

A Cell ◽

Tlr4 Activation

Exposure of neutrophils to LPS (lipopolysaccharide) triggers their oxidative response. However, the relationship between the signalling downstream of TLR4 (Toll-like receptor 4) after LPS stimulation and the activation of the oxidase remains elusive. Phosphorylation of the cytosolic factor p47phox is essential for activation of the NADPH oxidase. In the present study, we examined the hypothesis that IRAK-4 (interleukin-1 receptor-associated kinase-4), the main regulatory kinase downstream of TLR4 activation, regulates the NADPH oxidase through phosphorylation of p47phox. We show that p47phox is a substrate for IRAK-4. Unlike PKC (protein kinase C), IRAK-4 phosphorylates p47phox not only at serine residues, but also at threonine residues. Target residues were identified by tandem MS, revealing a novel threonine-rich regulatory domain. We also show that p47phox is phosphorylated in granulocytes in response to LPS stimulation. LPS-dependent phosphorylation of p47phox was enhanced by the inhibition of p38 MAPK (mitogen-activated protein kinase), confirming that the kinase operates upstream of p38 MAPK. IRAK-4-phosphorylated p47phox activated the NADPH oxidase in a cell-free system, and IRAK-4 overexpression increased NADPH oxidase activity in response to LPS. We have shown that endogenous IRAK-4 interacts with p47phox and they co-localize at the plasma membrane after LPS stimulation, using immunoprecipitation assays and immunofluorescence microscopy respectively. IRAK-4 was activated in neutrophils in response to LPS stimulation. We found that Thr133, Ser288 and Thr356, targets for IRAK-4 phosphorylation in vitro, are also phosphorylated in endogenous p47phox after LPS stimulation. We conclude that IRAK-4 phosphorylates p47phox and regulates NADPH oxidase activation after LPS stimulation.

Download Full-text

Platyphyllenone Induces Autophagy and Apoptosis by Modulating the AKT and JNK Mitogen-Activated Protein Kinase Pathways in Oral Cancer Cells

International Journal of Molecular Sciences ◽

10.3390/ijms22084211 ◽

2021 ◽

Vol 22 (8) ◽

pp. 4211

Author(s):

Yen-Tze Liu ◽

Hsin-Yu Ho ◽

Chia-Chieh Lin ◽

Yi-Ching Chuang ◽

Yu-Sheng Lo ◽

...

Keyword(s):

Protein Kinase ◽

Oral Cancer ◽

Protein Expression ◽

Caspase 3 ◽

Therapeutic Option ◽

Mapk Signaling ◽

Mitogen Activated Protein Kinase ◽

Dependent Manner ◽

Cancer Proliferation ◽

Mitogen Activated Protein

Platyphyllenone is a type of diarylheptanoid that exhibits anti-inflammatory and chemoprotective effects. However, its effect on oral cancer remains unclear. In this study, we investigated whether platyphyllenone can promote apoptosis and autophagy in SCC-9 and SCC-47 cells. We found that it dose-dependently promoted the cleavage of PARP; caspase-3, -8, and -9 protein expression; and also led to cell cycle arrest at the G2/M phase. Platyphyllenone up-regulated LC3-II and p62 protein expression in both SCC-9 and SCC-47 cell lines, implying that it can induce autophagy. Furthermore, the results demonstrated that platyphyllenone significantly decreased p-AKT and increased p-JNK1/2 mitogen-activated protein kinase (MAPK) signaling pathway in a dose-dependent manner. The specific inhibitors of p-JNK1/2 also reduced platyphyllenone-induced cleavage of PARP, caspase-3, and caspase -8, LC3-II and p62 protein expression. These findings are the first to demonstrate that platyphyllenone can induce both autophagy and apoptosis in oral cancers, and it is expected to provide a therapeutic option as a chemopreventive agent against oral cancer proliferation.

Download Full-text

Phosphothreonine Lyase Promotes p65 Degradation in a Mitogen-Activated Protein Kinase/Mitogen- and Stress-Activated Protein Kinase 1-Dependent Manner

Infection and Immunity ◽

10.1128/iai.00508-18 ◽

2018 ◽

Vol 87 (1) ◽

Cited By ~ 1

Author(s):

Mingyu Hou ◽

Wenhui Wang ◽

Feizi Hu ◽

Yuanxing Zhang ◽

Dahai Yang ◽

...

Keyword(s):

Protein Kinase ◽

Pathogenic Bacteria ◽

Critical Role ◽

Nuclear Factor Κb ◽

Mapk Signaling ◽

Mitogen Activated Protein Kinase ◽

Dependent Manner ◽

Content Type ◽

Catalytic Active Site ◽

Mitogen Activated Protein

ABSTRACT Bacterial phosphothreonine lyases have been identified to be type III secretion system (T3SS) effectors that irreversibly dephosphorylate host mitogen-activated protein kinase (MAPK) signaling to promote infection. However, the effects of phosphothreonine lyase on nuclear factor κB (NF-κB) signaling remain largely unknown. In this study, we detected significant phosphothreonine lyase-dependent p65 degradation during Edwardsiella piscicida infection in macrophages, and this degradative effect was blocked by the protease inhibitor MG132. Further analysis revealed that phosphothreonine lyase promotes the dephosphorylation and ubiquitination of p65 by inhibiting the phosphorylation of mitogen- and stress-activated protein kinase-1 (MSK1) and by inhibiting the phosphorylation of extracellular signal-related kinase 1/2 (ERK1/2), p38α, and c-Jun N-terminal kinase (JNK). Moreover, we revealed that the catalytic active site of phosphothreonine lyase plays a critical role in regulating the MAPK-MSK1-p65 signaling axis. Collectively, the mechanism described here expands our understanding of the pathogenic effector in not only regulating MAPK signaling but also regulating p65. These findings uncover a new mechanism by which pathogenic bacteria overcome host innate immunity to promote pathogenesis.

Download Full-text

Selective expression of the scaffold protein JSAP1 in spermatogonia and spermatocytes

Reproduction ◽

10.1530/rep.1.00939 ◽

2006 ◽

Vol 131 (4) ◽

pp. 711-719 ◽

Cited By ~ 6

Author(s):

Munkhuu Bayarsaikhan ◽

Akiko Shiratsuchi ◽

Davaakhuu Gantulga ◽

Yoshinobu Nakanishi ◽

Katsuji Yoshioka

Keyword(s):

Protein Kinase ◽

Western Blotting ◽

Cell Types ◽

Mapk Signaling ◽

Scaffold Protein ◽

Mitogen Activated Protein Kinase ◽

Interacting Protein ◽

Early Postnatal Development ◽

Mitogen Activated Protein ◽

Signaling Modules

Scaffold proteins of mitogen-activated protein kinase (MAPK) intracellular signal transduction pathways mediate the efficient and specific activation of the relevant MAPK signaling modules. Previously, our group and others have identified c-Jun NH2-terminal kinase (JNK)/stress-activated protein kinase-associated protein 1 (JSAP1, also known as JNK-interacting protein 3) as a scaffold protein for JNK MAPK pathways. Although JSAP1 is expressed in the testis in adults, its expression during development has not been investigated. In addition, it is unknown which types of cells in the testis express the scaffold protein. Here, we examined the expression of JSAP1 in the testis of mice aged 14 days, 20 days, 6 weeks, and 12 weeks by immunohistochemistry and Western blotting. The specificity of the anti-JSAP1 antibody was evaluated from its reactivity to exogenously expressed JSAP1 and a structurally related protein, and by antigen-absorption experiments. The immunohistochemical analyses with the specific antibody showed that the JSAP1 protein was selectively expressed in the spermatogonia and spermatocytes, but not in other cell types, including spermatids and somatic cells, during development. However, not all spermatogonia and spermatocytes were immunopositive either, especially in the 12-week-old mouse testis. Furthermore, we found by Western blotting that the expression levels of JSAP1 protein vary during development; there is high expression until 6 weeks after birth, which approximately corresponds to the end of the first wave of spermatogenesis. Collectively, these results suggest that JSAP1 function may be important in spermatogenic cells during early postnatal development.

Download Full-text

TNF-α and interleukin 1 activate gastrin gene expression via MAPK- and PKC-dependent mechanisms

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.2001.281.6.g1405 ◽

2001 ◽

Vol 281 (6) ◽

pp. G1405-G1412 ◽

Cited By ~ 24

Author(s):

T. Suzuki ◽

E. Grand ◽

C. Bowman ◽

J. L. Merchant ◽

A. Todisco ◽

...

Keyword(s):

Gene Expression ◽

Protein Kinase C ◽

Protein Kinase ◽

Kinase Inhibitor ◽

Interleukin 1 ◽

Mitogen Activated Protein Kinase ◽

G Cells ◽

Kinase C ◽

Tnf Α ◽

Mitogen Activated Protein

Helicobacter pyloriand proinflammatory cytokines have a direct stimulatory effect on gastrin release from isolated G cells, but little is known about the mechanism by which these factors regulate gastrin gene expression. We explored whether tumor necrosis factor (TNF)-α and interleukin (IL)-1 directly regulate gastrin gene expression and, if so, by what mechanism. TNF-α and IL-1 significantly increased gastrin mRNA in canine G cells to 181 ± 18% and 187 ± 28% of control, respectively, after 24 h of treatment. TNF-α and IL-1 stimulated gastrin promoter activity to a maximal level of 285 ± 12% and 415 ± 26% of control. PD-98059 (a mitogen-activated protein kinase kinase inhibitor), SB-202190 (a p38 kinase inhibitor), and GF-109203 (a protein kinase C inhibitor) inhibited the stimulatory action of both cytokines on the gastrin promoter. In conclusion, both cytokines can directly regulate gastrin gene expression via a mitogen-activated protein kinase- and protein kinase C-dependent mechanism. These data suggest that TNF-α and IL-1 may play a direct role in Helicobacter pylori-induced hypergastrinemia.

Download Full-text

Constitutive Activation of Mitogen-activated Protein Kinase Kinase (MEK1) in Ileal Enterocytes Leads to Dysplasia and a Predisposition to Cancer

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00065.2020 ◽

2021 ◽

Author(s):

Benjamin L. Shneider ◽

Nahir Cortes-Santiago ◽

Deborah A. Schady ◽

Swapna Krishnamoorthy ◽

Sundararajah Thevananther ◽

...

Keyword(s):

Body Weight ◽

Protein Kinase ◽

Cell Fate ◽

Dose Dependence ◽

Mitogen Activated Protein Kinase ◽

Proteomic Profiling ◽

Invasive Adenocarcinoma ◽

Reduced Body ◽

Mitogen Activated Protein ◽

Protein Kinase Kinase

Activation of Mitogen-activated protein kinases (MAPKs) is a key factor in the pathogenesis of cancer, although the specific role of mitogen-activated protein kinase kinase (MEK1) is not well understood. Villin promoter driven cre expression was used to excise a floxed stop cassette from a phosphomimetically constitutively activated MEK1 (caMEK1) expression construct in the intestine of C57BL/6 mice. Zygosity status of caMEK1 afforded assessment of the dose dependence of the effect. The expected mendelian distribution of genotypes and sex was observed in 443 progenies. Between 21 and 63 days of life caMEK1 had no effect on body weight in male mice, but reduced body weight in female mice homozygous for caMEK1. At 10 weeks of age, the ileum of caMEK1 expressing mice was characterized by the finding of dysplasia and profound changes in overall architecture. Paneth cells were nearly absent in caMEK1 homozygotes. Targeted proteomic profiling via reverse phase protein array analyses with confirmatory western blotting revealed significant changes in protein and phosphoprotein expression including up-regulation of proteins downstream of MEK1, associated with enhanced markers of proliferation, diminished apoptosis, alterations in cell-fate determination, cell-cell interactions and tight junctions. Long-term viability of caMEK1 homozygous mice was reduced with no survival beyond one year. Invasive adenocarcinoma developed in three of ten older mice (15 [homozygous], 26 [homozygous] and 35 weeks [heterozygous] of age). Expression of caMEK1 in enterocytes leads to marked derangements in the intestinal epithelium, which is associated with a predisposition to the development of invasive cancer.

Download Full-text