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P38 mitogen-activated protein kinase-? inhibition by long-acting ?2 adrenergic agonists reversed steroid insensitivity in severe asthma.

ABSTRACT: Corticosteroid insensitivity (CI) is a major barrier to treating severe asthma. Despite intensive research, the molecular mechanism of CI remains uncertain. The aim of this study was to determine abnormality in corticosteroid action in severe asthma and to identify the molecular mechanism of the long-acting ?(2)-adrenergic agonists (LABAs) formoterol and salmeterol on restoration of corticosteroid sensitivity in severe asthma in vitro. Peripheral blood mononuclear cells (PBMCs) were obtained from 16 subjects with severe corticosteroid-insensitive asthma, 6 subjects with mild corticosteroid-sensitive asthma, and 11 healthy volunteers. Corticosteroid (dexamethasone) sensitivity was determined on tumor necrosis factor-? (TNF-?)-induced interleukin (IL)-8 production. Glucocorticoid receptor (GR) phosphorylation and kinase phosphorylation were evaluated by immunoprecipitation-Western blotting analysis and kinase phosphorylation array in IL-2/IL-4-treated corticosteroid insensitive model in PBMCs. In vitro corticosteroid sensitivity on TNF-?-induced IL-8 production was significantly lower in patients with severe asthma than in healthy volunteers and patients with mild asthma. This CI seen in severe asthma was associated with reduced GR nuclear translocation and with hyperphosphorylation of GR, which were reversed by LABAs. In IL-2/IL-4-treated PBMCs, LABAs inhibited phosphorylation of Jun-NH(2)-terminal kinase and p38 mitogen-activated protein kinase-? (p38MAPK-?) as well as GR. In addition, cells with p38MAPK-? knockdown by RNA interference did not develop CI in the presence of IL-2/IL-4. Furthermore, p38MAPK-? protein expression was up-regulated in PBMCs from some patients with severe asthma. In conclusion, p38 MAPK-? activation impairs corticosteroid action and p38 MAPK-? inhibition by LABAs has potential for the treatment of severe asthma.

SUBMITTER: Mercado N

PROVIDER: S-EPMC3228526 | biostudies-literature | 2011 Dec

REPOSITORIES: biostudies-literature

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p38 mitogen-activated protein kinase-γ inhibition by long-acting β2 adrenergic agonists reversed steroid insensitivity in severe asthma.

Mercado Nicholas N To Yasuo Y Kobayashi Yoshiki Y Adcock Ian M IM Barnes Peter J PJ Ito Kazuhiro K

Molecular pharmacology 20110914 6

Corticosteroid insensitivity (CI) is a major barrier to treating severe asthma. Despite intensive research, the molecular mechanism of CI remains uncertain. The aim of this study was to determine abnormality in corticosteroid action in severe asthma and to identify the molecular mechanism of the long-acting β(2)-adrenergic agonists (LABAs) formoterol and salmeterol on restoration of corticosteroid sensitivity in severe asthma in vitro. Peripheral blood mononuclear cells (PBMCs) were obtained fro ...[more]

PMID: 21917909

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Project description:AimsSome asthma patients remain symptomatic despite using high doses of inhaled corticosteroids (ICS). We used alveolar macrophages to identify individual patients with insensitivity to corticosteroids and to evaluate the anti-inflammatory effects of a p38 mitogen-activated protein kinase (MAPK) inhibitor combined with a corticosteroid on these cells.MethodsAlveolar macrophages from 27 asthma patients (classified according to the Global Initiative for Asthma (GINA) treatment stage. Six GINA1, 10 GINA2 and 11 GINA3/4) were stimulated with lipoploysaccharide (LPS) (1 ?g ml(-1)). The effects of dexamethasone (dex 1-1000 nm), the p38 MAPK inhibitor 1-(5-tert-butyl-2-p-tolyl-2Hpyrazol-3-yl)-3(4-(2-morpholin-4-yl-ethoxy)naphthalen-1-yl)urea (BIRB-796 1-1000 nm) and both drugs combined at all concentrations on supernatant TNF?, IL-6 and CXCL-8 concentrations were analyzed by ELISA. Dose-sparing and efficacy enhancing effects of combination treatment were determined.ResultsDexamethasone reduced LPS-induced TNF?, IL-6 and CXCL-8 in all groups, but maximum inhibition was significantly reduced for GINA3/4 compared with GINA2 and GINA1 (P < 0.01). A subgroup of corticosteroid insensitive patients with a reduced effect of dexamethasone on cytokine secretion were identified. BIRB-796 in combination with dexamethasone significantly increased cytokine inhibition compared with either drug alone (P < 0.001) in all groups. This effect was greater in corticosteroid insensitive compared with sensitive patients. There were significant synergistic dose-sparing effects (P < 0.05) for the combination treatment on inhibition of TNF?, IL-6 and CXCL-8 in all groups. There was also significant efficacy enhancing benefits (P < 0.05) on TNF? and IL-6.Conclusionsp38 MAPK inhibitors synergistically enhance efficacy of corticosteroids in macrophages from asthma patients. This effect is greater in corticosteroid insensitive asthma patients, suggesting that this class of drug should be targeted to this patient phenotype.

Project description:Skin cancer is one of the most common cancers worldwide. Melanoma accounts for ~5% of skin cancers but causes the large majority of skin cancer?related deaths. Recent discoveries have shown that the mitogen?activated protein kinase (MAPK) signaling pathway is critical for melanoma development and progression. Many oncogenic pathways that cause melanoma tumorigenesis have been identified, most of which are due to RAF/MEK/ERK (MAPK) pathway activation. However, the precise role of p38 remains unclear. Using specific short hairpin (sh) RNA to silence p38? and p38?, the present findings demonstrated that p38? was a crucial factor in regulating cell migration in the A375 melanoma cell line. Silencing p38? downregulated the expression of epithelial?mesenchymal transition markers, such as matrix metallopeptidase (MMP) 2, MMP9, twist family bHLH transcription factor 1, snail family transcriptional repressor 1 and vimentin, while mesenchymal?epithelial transition markers, such as E?cadherin, were upregulated. Of note, the results also demonstrated that p38? silencing impaired vascular endothelial growth factor expression, which regulates tumor angiogenesis. Furthermore, p38? knockdown inhibited cell proliferation in melanoma cells. In addition, silencing p38? induced senescence?like features, but not cell cycle arrest. Expression of the senescence markers p16, p21, p53 and ??galactosidase was upregulated, and an increase in the number of senescence?associated ??galactosidase?positive cells was observed in a p38? knockdown stable clone. However, no significant difference was found between control and p38? stable knockdown cells. Taken together, the present results suggested that p38? knockdown impaired migration and proliferation, and increased senescence, in A375 melanoma cells. However, p38? may not be involved in melanoma tumorigenesis. Therefore, targeting p38? may be a valuable approach towards inhibiting tumor growth and metastasis in patients with melanoma.

Dataset Information

P38 mitogen-activated protein kinase-? inhibition by long-acting ?2 adrenergic agonists reversed steroid insensitivity in severe asthma.

Publications

p38 mitogen-activated protein kinase-γ inhibition by long-acting β2 adrenergic agonists reversed steroid insensitivity in severe asthma.

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