μ-opioid Receptor-Mediated Alterations of Allergen-Induced Immune Responses of Bronchial Lymph Node Cells in a Murine Model of Stress Asthma

ABSTRACTBackgroundPsychological stress has a recognized association with asthma symptoms. Using a murine model of allergic asthma, we recently demonstrated the involvement of μ-opioid receptors (MORs) in the central nervous system in the stress-induced exacerbation of airway inflammation. However, the involvement of MORs on neurons and immunological alterations in the stress asthma model remain unclear.MethodsMOR-knockout (MORKO) mice that express MORs only on noradrenergic and adrenergic neurons (MORKO/Tg mice) were produced and characterized for stress responses. Sensitized mice inhaled antigen and were then subjected to restraint stress. After a second antigen inhalation, bronchoalveolar lavage cells were counted. Before the second inhalation, bronchial lymph node (BLN) cells and splenocytes from stressed and non-stressed mice were cultured with antigen, and cytokine levels and the proportions of T cell subsets were measured.ResultsStress-induced worsening of allergic airway inflammation was observed in wild-type and MORKO/Tg mice but not MORKO mice. In wild-type stressed mice, IFN-γ/IL-4 ratios in cell culture supernatants and the proportion of regulatory T cells in BLN cell populations were significantly lower than those in non-stressed mice. These differences in BLN cells were not observed between the stressed and non-stressed MORKO mice. Restraint stress had no effect on cytokine production or T cell subsets in splenocytes.ConclusionsRestraint stress aggravated allergic airway inflammation in association with alterations in local immunity characterized by greater Th2-associated cytokine production and a reduced development of regulatory T cells, mediated by MORs

アレルギー性気道炎症の性差の加齢変化-サイトカイン産生とプロゲステロンの影響に関する検討-

The incidence,severity and prognosis of asthma can be affected by a number of factors,including the patient\u27s age and sex.Clinical observations and epidemiologic studies indicate that the severity of asthma is higher among boys than girls,but that the ratio inverts after puberty.Thereafter,in the elderly,the sex difference disappears.However,the mechanisms underlying the age-related sex differences in the severity of asthma are not clear.Therefore,to clarify the mechanisms we compared using a murine model of asthma allergen-induced airway inflammation and the effect of progesterone on antigen-induced cytokine production by lymphocytes betoween the different age and sex.In 6 weeks old C57BL/6 mice,the airway inflammation in flammation in female mice sensitized with OVA followed by OVA inhalation was more severe than in male mice,whereas the sex difference in the airway inflammation was not observed in 16 weeks old mice.In not only 6 but also 16 weeks old mice,bronchial lymph nodes (BLN) cells from OVA-sensitized female mice produced more Th2 cytokine,than those from age-matched male mice,upon simulation with OVA.Progesterone did not significantly affect the sex difference in Th2 cytokine production by BLN cells in either 6 or 16 weeks old mice.Our findings suggest that the age-related sex differences in allergic airway inflammation are not due to simply the differences in lymphocytes function and sensiticities to progesterone

Unexpected biotic resilience on the Japanese seafloor caused by the 2011 Tōhoku-Oki tsunami

On March 11th, 2011 the Mw 9.0 2011 Tōhoku-Oki earthquake resulted in a tsunami which caused major devastation in coastal areas. Along the Japanese NE coast, tsunami waves reached maximum run-ups of 40 m, and travelled kilometers inland. Whereas devastation was clearly visible on land, underwater impact is much more difficult to assess. Here, we report unexpected results obtained during a research cruise targeting the seafloor off Shimokita (NE Japan), shortly (five months) after the disaster. The geography of the studied area is characterized by smooth coastline and a gradually descending shelf slope. Although high-energy tsunami waves caused major sediment reworking in shallow-water environments, investigated shelf ecosystems were characterized by surprisingly high benthic diversity and showed no evidence of mass mortality. Conversely, just beyond the shelf break, the benthic ecosystem was dominated by a low-diversity, opportunistic fauna indicating ongoing colonization of massive sand-bed deposits.Peer reviewe

Colocalization and binding of RAGE and MT1-MMP in endothelial cells.

<p>(A) Association of RAGE and MT1-MMP according to fluorescent immunohistochemistry. Merged image indicates that RAGE is partially colocalized with MT1-MMP. Photomicrographs are from an experiment representative of 3 independent experiments. (B) Formation of a complex of RAGE and MT1-MMP as determined by immunoprecipitation with or without HMGB-1 stimulation. Immunoprecipitates made using an isotype-matched control antibody did not show 44-kDa band (Fig. 6B, lane 1 and 3), whereas 44 kDa band recognized by immunoblotting with anti-RAGE antibody was detected in the MT1-MMP-immunoprecipitates (Fig. 6B, lane 2 and 4).</p

Rapid RhoA and Rac1 activation in HMGB-1 stimulated endothelial cells.

<p>Levels of GTP-bound active forms of RhoA and Rac1 as determined by pull-down assays in cultured HAECs 5 to 30 minutes after adding 500 ng/ml HMGB-1. Bars are mean±S.D. of quantitative densitometric analyses from 4 separate experiments. Representative immunoblots from 4 separate experiments are shown. ^*<i>P</i><0.05 vs. Lane 1.</p

HMGB-1 increases MT1-MMP activity in cultured endothelial cells.

<p>Plasma membrane fractions were extracted from HAECs. Changes in the activity of MT1-MMP are shown after HMGB-1 stimulation. Results are expressed as mean±S.D. of 3 separate experiments performed in pentaplicate. ^*<i>P</i><0.05 vs. 0 minute before HMGB-1 stimulation.</p

Effects of inhibition of MT1-MMP with siRNA on increased GTP-loading of RhoA and Rac1 caused by HMGB-1 in HAECs.

<p>(A) Effect of knockdown of MT1-MMP by siRNA on the MT1-MMP protein level as determined by western blotting. Bars are mean ±S.D. of quantitative densitometric analyses from 3 separate experiments. Representative immunoblots from 3 independent experiments are shown. *<i>P</i><0.05 vs. Lane 1. (B and C) Cells were incubated in the presence of HMGB-1 with or without transfection with siRNA to MT1-MMP. Bars are mean±S.D. of 4 separate experiments. Representative immunoblots from 4 independent experiments are shown. ^*<i>P</i><0.05 vs Lane 1; ^†<i>P</i><0.05 vs. Lane 2.</p

Effects of inhibition of RAGE with siRNA on increased GTP-loading of RhoA and Rac1 caused by HMGB-1 in HAECs.

<p>(A) Effect of knockdown of RAGE by siRNA on the RAGE protein level as determined by western blotting. Bars are mean ±S.D. of quantitative densitometric analyses from 3 separate experiments. Representative immunoblots from 3 independent experiments are shown. *<i>P</i><0.05 vs. Lane 1. (B and C) Cells were incubated in the presence of HMGB-1 with or without transfection with siRNA to RAGE. Bars are mean±S.D. of 4 separate experiments. Representative immunoblots from 4 separate experiments are shown. ^*<i>P</i><0.05 vs Lane 1; ^†<i>P</i><0.05 vs. Lane 2.</p

RhoA and Rac1 activation stimulated by HMGB-1 in endothelial cells.

<p>Levels of GTP-bound active forms of RhoA and Rac1 as determined by pull-down assays in cultured human aortic endothelial cells (HAECs) stimulated by 250 to 1000 ng/ml HMGB-1. Bars are mean±S.D. of quantitative densitometric analyses from 3 separate experiments. Representative immunoblots from 3 separate experiments are shown. ^*<i>P</i><0.05 vs. Lane 1.</p

The involvement of central nervous system histamine receptors in psychological stress-induced exacerbation of allergic airway inflammation in mice

Background: Psychological stress is one of the major risk factors for asthma exacerbation. Although histamine in the brain acts as an excitatory and inhibitory neurotransmitter associated with psychological stress, the contribution of brain histamine to psychological stress-induced exacerbation of asthma remains unclear. The objective of this study was to investigate the role of histamine receptors in the CNS on stress induced asthma aggravation. Methods: We monitored the numbers of inflammatory cells and interleukin (IL)-13 levels in bronchoalveolar lavage fluid, airway responsiveness to inhaled methacholine, mucus secretion in airway epithelial cells, and antigen-specific IgE contents in sera in a murine model of stress-induced asthma treated with epinastine (an H1R antagonist), thioperamide (an H3/4R antagonist), or solvent. Results: All indicators of stress-induced asthma exacerbation were significantly reduced in stressed mice treated with epinastine compared with those treated with solvent, whereas treatment with thioperamide did not reduce the numbers of inflammatory cells in the stressed mice. Conclusions: These results suggest that H1R, but not H3/4R, may be involved in stress-induced asthma exacerbations in the central nervous system