Capsicum annuum L. methanolic extract inhibits ovalbumin-induced airway inflammation and oxidative stress in a mouse model of asthma

The pepper fruit of Capsicum annuum L. is used as a food, spice, and topical medicine. Here, we investigated the effect of a methanolic C. annuum L. extract (CAE) in a mouse model of ovalbumin-induced allergic airway inflammation. Animals were treated with CAE by oral gavage before ovalbumin challenge. After ovalbumin challenge, airway responsiveness to methacholine, influx of inflammatory cells into the lung, cytokine levels in bronchoalveolar lavage fluid and lung, nuclear factor-κB (NF-κB) activity in lungs, and lung histopathology were assessed. Oral treatment with CAE significantly reduced the pathophysiological signs of allergic airway disease, including increased inflammatory cell recruitment to the airways, airway hyperresponsiveness, and increased levels of T-helper type 2 cytokines. Reactive oxygen species were also decreased in cells from bronchoalveolar lavage fluid. In addition, we found that administration of CAE attenuated ovalbumin-induced increases in NF-κB activity in lungs. Collectively, these results suggest that CAE may be an effective oral treatment for allergic airway inflammation by virtue of its antioxidant activity.     

Asian sand dust enhances ovalbumin-induced eosinophil recruitment in the alveoli and airway of mice

Asian sand dust (ASD) containing sulfate (SO4(2-)) reportedly causes adverse respiratory health effects but there is no experimental study showing the effect of ASD toward allergic respiratory diseases. The effects of ASD and ASD plus SO4(2-) toward allergic lung inflammation induced by ovalbumin (OVA) were investigated in this study. ICR mice were administered intratracheally with saline; ASD alone (sample from Shapotou desert); and ASD plus SO4(2-) (ASD-SO4); OVA+ASD; OVA+ASD-SO4. ASD or ASD-SO4 alone caused mild nutrophilic inflammation in the bronchi and alveoli. ASD and ASD-SO4 increased pro-inflammatory mediators, such as Keratinocyte chemoattractant (KC) and macrophage inflammatory protein (MIP)-1 alpha, in bronchoalveolar lavage fluids (BALF). ASD and ASD-SO4 enhanced eosinophil recruitment induced by OVA in the alveoli and in the submucosa of the airway, which has a goblet cell proliferation in the bronchial epithelium. However, a further increase of eosinophils by addition of SO4(2-) was not observed. The two sand dusts synergistically increased interleukin-5 (IL-5) and monocyte chemotactic protein-1 (MCP-1), which were associated with OVA, in BALF. However, the increased levels of IL-5 were lower in the OVA+ASD-SO4 group than in the OVA+ASD group. ASD caused the adjuvant effects to specific-IgG1 production by OVA, but not to specific-IgE. These results suggest that the enhancement of eosinophil recruitment in the lung is mediated by synergistically increased IL-5 and MCP-1. IgG1 antibodies may play an important role in the enhancement of allergic reaction caused by OVA and sand dust. However, extra sulfate may not contribute to an increase of eosinophils.     

登革病毒诱导人单核细胞miR-146a表达的机制研究

目的 探究登革病毒感染引起miR-146a高表达所依赖的天然免疫信号通路。方法 通过RNAi技术沉默登革病毒感染后激活的信号通路的上游蛋白,或采用信号分子抑制剂阻断登革病毒感染后激活的信号通路的下游因子,然后通过real-time PCR检测miR-146a的表达变化。 结果 DENV2感染引起的miR-146a的表达沉默IPS-1后减少了60%,而TLR3的沉默对miR-146a的表达无影响;采用特异性的抑制剂抑制NF-κB、IKK、p38和JNK后均可下调miR-146a的表达,而ERK的抑制对miR-146a的表达无明显影响。 结论 登革病毒感染诱导miR-146a的表达依赖于上游RIG-I/MDA5-IPS-1以及下游的p38、IKK/JNK和NF-κB,而不依赖于上游的TLR3和下游的ERK。miR-146a可能成为预防和治疗登革病毒感染的一个新靶标,最终为临床治疗和预防登革出血热提供一个新的视野。     

Mast cells and the development of allergic airway disease

Murine models have highlighted the importance of T-cells and TH2 cytokines in development of allergen-induced airway disease. In contrast, the role of mast cells for the development of allergic airway disease has been controversial. Recent studies in murine models demonstrate a significant contribution of mast cells during the development of airway hyperresponsiveness and airway inflammation. Furthermore these models have allowed identifying certain mast cell-produced mediators (e.g. histamine and leukotriene B4) to be involved in the recruitment of effector T-cells into the lung. Additionally, mast cell-produced TNF can directly activate TH2 cells and contribute to the development of allergic airway disease. These new findings demonstrate a complex role of mast cells and their mediators, not only as effector cells, but also during sensitization and development of allergic airway disease. Therefore mast cells and certain mast cell-produced mediators might be an interesting target for the prevention and treatment of allergic asthma.     

哮喘儿童诱导痰液趋化因子在气道炎症及哮喘病情评价中的意义

目的:探讨诱导痰液趋化因子在哮喘儿童气道炎症及哮喘病情评价中的意义。方法:90例哮喘患儿作为研究对象,20例健康体检儿童作为对照组。所有研究对象均进行痰液诱导及诱导痰细胞学分析,ELISA法检测痰液调节正常T细胞表达和分泌活性因子(RANTES)、嗜酸性粒细胞趋化蛋白-2(Eotaxin-2)、白细胞介素-8(IL-8)、单核细胞趋化蛋白-1(MCP-1),儿童肺功能仪检测基础肺功能。应用SPSS13.0软件进行统计学分析。结果:①哮喘患儿诱导痰液趋化因子RAN-TES、Eotaxin-2、IL-8、MCP-1水平高于健康对照组,两组比较差异有统计学意义(P<0.05)。②哮喘患儿急性发作期诱导痰RANTES、Eotaxin-2水平高于缓解期,两者比较差异有统计学意义(P<0.05)。③重度发作哮喘组IL-8、MCP-l水平高于轻～中度发作哮喘组,两组差异有统计学意义(P<0.05)。结论:哮喘患儿诱导痰趋化因子RANTES、Eotaxin-2与哮喘急性发作和气道高反应性有关,而诱导痰IL-8、MCP-1与哮喘病情加重及肺功能恶化有关。动态检测哮喘患儿诱导痰中趋化因子变化,将有助于哮喘病情监控和哮喘的个体化治疗方案的制定。     

Cis-9,trans-11-conjugated linoleic acid inhibits allergic sensitization and airway inflammation via a PPARgamma-related mechanism in mice

Milk consumption from early childhood on has been found to be inversely correlated with allergic sensitization and the onset of bronchial asthma. We tested whether cis-9,trans-11-conjugated linoleic acid (c9,t11-CLA), naturally occurring in milk fat, may prevent allergic sensitization and inhibit airway inflammation in a murine asthma model. BALB/c mice were fed a diet enriched in 1 wt% of c9,t11-CLA or a control diet 7 d prior to and for 32 d during sensitization [d 1 and 14, 100 mg/L ovalbumin (OVA) in adjuvant vs. PBS] and airway challenges (d 28-30, 1% OVA in PBS vs. PBS). Subgroups of mice were coadministered 20 micromol/L of the selective PPARgamma antagonist GW9662 during each OVA challenge. C9,t11-CLA feeding resulted in significantly reduced IgE production and allergen-induced in vivo airway hyperresponsiveness. Further, less mucous plugging of segmental bronchi and significantly reduced interleukin-5 and eosinophils were determined in bronchoalveolar lavage fluids of c9,t11-CLA-fed mice. C9,t11-CLA feeding prevented the downregulation of PPARgamma mRNA in the lung tissues observed after allergen sensitization and airway challenges in control mice. The inhibitory effects of c9,t11-CLA on airway inflammation were partially prevented by coadministration of GW9962. Further, c9,t11-CLA feeding resulted in a significantly lower concentration of the eicosanoid precursor, arachidonic acid, in tissue lipids. These findings demonstrate that dietary c9,t11-CLA can reduce allergic airway inflammation, most likely via a PPARgamma-related mechanism and by reducing eicosanoid precursors. They give new insights into the fatty acid-mediated mechanism of immunomodulation and may represent a step toward an attractive novel strategy in the dietary prevention and treatment of allergic asthma.     

Dietary supplementation with geranylgeraniol suppresses lipopolysaccharide-induced inflammation via inhibition of nuclear factor-κB activation in rats

Purpose

The isoprenoid geranylgeraniol (GGOH) inhibits nuclear factor-kappa B (NF-κB) activation in the liver, yet the mechanism remains unclear. We investigated the modulation and inhibition of lipopolysaccharide (LPS)-induced NF-κB signaling in the liver of rats fed a GGOH-supplemented diet.

Methods

Rats were fed a diet supplemented with or without GGOH for 10 days. Rats were then intraperitoneally injected with 0.5 mg/kg LPS or vehicle (sterilized saline) and fasted for 18 h. Plasma levels of the inflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6, and the liver damage indicators alanine and aspartate aminotransferases (ALT and AST) were assessed. Liver mRNA and proteins were assayed for changes in NF-κB target genes and signal transduction genes.

Results

Rats fed a high-dose, GGOH-supplemented diet showed significantly lower levels of plasma inflammatory cytokines and ALT and AST activities. In the liver, GGOH significantly suppressed NF-κB activation and mRNA expression of its pro-inflammatory target genes. Furthermore, GGOH supplementation substantially suppressed mRNA expression of signal transducer genes upstream of the IκB kinase complex. Western blotting of liver extracts further demonstrated the substantial decrease in total IL-1 receptor-associated kinase 1 (IRAK1) and TNF receptor-associated factor 6 (TRAF6), leading to lower signal transduction and inhibition of NF-κB after LPS.

Conclusion

A 10-day, high-dose, GGOH-supplemented diet was sufficient to inhibit LPS-induced inflammation and activation of NF-κB in rat livers. GGOH significantly modulated NF-κB signaling molecules, inhibiting its signal transduction and activation in the liver, thus protecting against liver damage.     

Physiogenomic comparison of human fat loss in response to diets restrictive of carbohydrate or fat

Background

Adipocytes express inflammatory mediators that contribute to the low-level, chronic inflammation found in obese subjects and have been linked to the onset of cardiovascular disorders and insulin resistance associated with type 2 diabetes mellitus. A reduction in inflammatory gene expression in adipocytes would be expected to reverse this low-level, inflammatory state and improve cardiovascular function and insulin sensitivity. The natural products, curcumin and resveratrol, are established anti-inflammatory compounds that mediate their effects by inhibiting activation of NF-κB signaling. In the present study, we examined if these natural products can inhibit NF-κB activation in adipocytes and in doing so reduce cytokine expression.

Methods

Cytokine (TNF-α, IL-1β, IL-6) and COX-2 gene expression in 3T3-L1-derived adipocytes was measured by quantitative real-time PCR (qRT-PCR) with or without TNFα-stimulation. Cytokine protein and prostaglandin E₂ (PGE₂) expression were measured by ELISA. Effects of curcumin and resveratrol were evaluated by treating TNFα-stimulated adipocytes with each compound and 1) assessing the activation state of the NF-κB signaling pathway and 2) measuring inflammatory gene expression by qRT-PCR and ELISA.

Results

Both preadipocytes and differentiated adipocytes express the genes for TNF-α, IL-6, and COX-2, key mediators of the inflammatory response. Preadipocytes were also found to express IL-1β; however, IL-1β expression was absent in differentiated adipocytes. TNF-α treatment activated NF-κB signaling in differentiated adipocytes by inducing IκB degradation and NF-κB translocation to the nucleus, and as a result increased IL-6 (6-fold) and COX-2 (2.5-fold) mRNA levels. TNF-α also activated IL-1β gene expression in differentiated adipocytes, but had no effect on endogenous TNF-α mRNA levels. No detectable TNFα or IL-1β was secreted by adipocytes. Curcumin and resveratrol treatment inhibited NF-κB activation and resulted in a reduction of TNF-α, IL-1β, IL-6, and COX-2 gene expression (IC₅₀ = 2 μM) and a reduction of secreted IL-6 and PGE₂ (IC₅₀ ~ 20 μM).

Conclusion

Curcumin and resveratrol are able to inhibit TNFα-activated NF-κB signaling in adipocytes and as a result significantly reduce cytokine expression. These data suggest that curcumin and resveratrol may provide a novel and safe approach to reduce or inhibit the chronic inflammatory properties of adipose tissue.     

肠道菌群通过短链脂肪酸参与过敏性哮喘气道高反应机制研究进展

支气管哮喘(简称哮喘)是一种以可逆性气流阻塞和气道高反应性为特点的气道慢性炎症疾病;短链脂肪酸(SCFAs)是肠道益生菌发酵不易消化的碳水化合物如膳食纤维、抗性淀粉等生成的产物,不仅是机体重要的能量来源,还是重要的免疫信号分子,血液中SCFAs浓度升高对肺部过敏性炎症起保护作用。大量研究表明哮喘发生与肠道菌群变化密切相关。本文从ERK1/2信号通路、TGF-β1/Smads信号传导通路、GPR41 和 GPR43的表达三个方面综述了肠道菌群通过短链脂肪酸参与哮喘气道高反应的可能发生分子机制,为哮喘的治疗提供潜在的新靶点。     

Anti-inflammatory activity of sublingual immunoglobulin (SLIG) in a murine model of allergen-driven airway inflammation

Aim

Intravenous immunoglobulin (IVIG) displays anti-inflammatory activities in many diseases. Subcutaneous administration of anti-IgE in humans provides benefit in severe persistent allergic asthma. Given the well established efficacy of sublingual allergen immunotherapy in respiratory type I allergies, we investigated the therapeutic potential of sublingual immunoglobulin (SLIG), most particularly anti-IgE SLIG, in a murine model of allergen-driven airway inflammation.

Methods

BALB/c mice sensitized with ovalbumin (OVA) were treated sublingually with rat monoclonal IgG1 or IgG2a, either directed to mouse IgE or with no reported specificity. Airway hyperresponsiveness (AHR) was assessed by whole body plethysmography, and eosinophil infiltrates were characterized in bronchial alveolar lavages (BAL). OVA-specific antibody and T cell responses were analyzed in sera and saliva or lung and draining lymph nodes, by ELISA or CBA measurement of cytokine production, respectively.

Results

AHR and BAL eosinophil infiltrates were substantially decreased in mice treated sublingually with particulate OVA (positive control), as well as in animals receiving various rat IgG1, irrespective of their specificity for murine IgE. In contrast, no improvement was observed in mice treated with PBS (negative control) or various rat IgG2a. SLIG anti-inflammatory activity is not related to a downregulation of Th2, Th17 or an induction of Foxp3⁺ CD4⁺ regulatory T cell responses. Mass spectrometry analysis of glycan moieties, such as sialic acid, suggests that the differential efficacy of rat IgG1 and IgG2a is not related to their capacity to interact with lectins borne by oral immune cells.

Conclusions

In a murine model of allergen-driven airway inflammation, SLIG exhibits an anti-inflammatory activity irrespective of the immunoglobulin specificity, and in the absence of allergen. As a noninvasive approach, SLIG deserves to be further studied as a treatment for other inflammatory diseases beyond allergic asthma.     

CTRP9抑制幼年哮喘小鼠气道平滑肌细胞增殖和炎性反应的研究

目的 研究C1q/肿瘤坏死因子相关蛋白9(CTRP9)对哮喘幼鼠气道平滑肌细胞(airway smooth muscle cells,ASMCs)增殖和气道炎症的作用。方法 ELISA检测正常、哮喘儿童和小鼠血清中CTRP9含量;原代培养哮喘小鼠ASMCs,经pcDNA3.1-CTRP9转染后,MTT检测ASMCs增殖,ELISA测定TNF-α和IL-6含量,Western 印记检测TLR4和NF-κB p65蛋白表达以及NF-κB p65磷酸化水平;pcDNA3.1-CTRP9转染哮喘小鼠,HE染色观察肺组织炎性细胞的浸润程度;收集小鼠支气管肺泡灌洗液(bronchoalveolar lavage fluid,BALF),光镜下检测嗜酸性粒细胞、巨噬细胞和中性粒细胞数目;检测小鼠肺部TNF-α、IL-6、TLR4和NF-κB的表达。结果 哮喘儿童和小鼠血清中CTRP9含量低于正常组;CTRP9能抑制ASMCs增殖、炎症因子分泌和TLR4/NF-κB通路活化;CTRP9也能抑制哮喘小鼠肺部炎性细胞浸润、各炎性反应细胞数目、炎症因子分泌和TLR4/NF-κB通路活化。结论 CTRP9能抑制幼年哮喘小鼠ASMCs增殖和炎性反应。     

变应性鼻炎大鼠TNFAIP3基因在鼻腔上皮细胞的表达

目的 研究致敏-治疗过程中肿瘤坏死因子α诱导蛋白3(tumor necrosis factor alpha-induced protein 3,TNFAIP3)基因在大鼠鼻腔黏膜上皮的表达,探讨TNFAIP3基因在变应性鼻炎免疫进程中的作用.方法 本实验于在2019年1月—2020年1月开展,将24只Wistar大鼠,...     

视黄酸对大鼠哮喘模型多种炎性因子的影响

目的探讨吸入视黄酸(RA)对急性发作期和慢性持续期哮喘大鼠多种炎症因子影响和作用机制。方法以鸡卵清蛋白(OVA)激发大鼠7d或30 d以制备急性或慢性哮喘模型。在1-7 d或23-30 d期间分别用10μg/ml RA(RA组)、10μg RA+5μg/ml budesonide(RA+BU组)、石蜡油(PO组)雾化吸入治疗1周。急性模型7 d后取血清与肺脏进行检测,慢性模型30 d及随后休息10 d取上清与肺脏进行检测。用免疫荧光、ELISA法检查肺间质细胞因子与血Th因子表达。结果急性发作期PO组胸腺基质淋巴细胞生成素(TSLP)、核因子-κB(NF-κB)、干细胞因子(SCF)表达增加。RA能下调TSLP,但SCF明显上调。慢性持续期PO组TSLP、NF-κB、SCF、IL-4随时间逐步上调,肺感染病灶多,肺泡隔中度增宽。RA组主要炎症因子水平逐渐降低,其中TSLP、IL-4、SCF减少具统计学差异;肺感染病灶少,肺泡隔增宽较轻。BU+RA组下调TSLP表达,但SCF持续上调,肺泡出血与感染较重。结论 RA通过活化巨噬细胞,短暂加重急性发作期哮喘过敏反应,但抑制慢性持续期哮喘肺间质过敏炎症,具免疫调整和抗感染作用。     

Inner Shell of the Chestnut (Castanea crenatta) Suppresses Inflammatory Responses in Ovalbumin-Induced Allergic Asthma Mouse Model

The inner shell of the chestnut (Castanea crenata) contains various polyphenols, which exert beneficial biological effects. Hence, we assessed the anti-inflammatory efficacy of a chestnut inner shell extract (CIE) in ovalbumin (OVA)-induced allergic asthma. We intraperitoneally injected 20 μg of OVA with 2 mg of aluminum hydroxide on days 0 and 14. On test days 21, 22, and 23, the mice were treated with aerosolized 1% (w/v) OVA in saline. CIE was administered orally at 100 and 300 mg/kg on days 18–23. CIE significantly reduced inflammatory cytokines and cells and immunoglobulin-E increased by OVA. Anti-inflammatory efficacy was revealed by reduction of inflammatory cell migration and mucus secretion in lung tissue. Further, CIE suppressed the OVA-induced nuclear factor kappa B (NF-κB) phosphorylation. Accordingly, the expression of cyclooxygenase (COX-2), inducible nitric oxide synthase (iNOS), and matrix metalloproteinase-9 (MMP-9) were decreased sequentially in lung tissues. CIE alleviated OVA-induced airway inflammation by restraining phosphorylation of NF-κB and the sequentially reduced expression of iNOS, COX-2, leading to reduced MMP-9 expression. These results indicate that CIE has potential as a candidate for alleviating asthma.     

Kaempferol Inhibits Angiogenesis and VEGF Expression Through Both HIF Dependent and Independent Pathways in Human Ovarian Cancer Cells

Ovarian cancer is 1 of the most significant malignancies in the Western world, and the antiangiogenesis strategy has been postulated for prevention and treatment of ovarian cancers. Kaempferol is a natural flavonoid present in many fruits and vegetables. The antiangiogenesis potential of kaempferol and its underlying mechanisms were investigated in two ovarian cancer cell lines, OVCAR-3 and A2780/CP70. Kaempferol mildly inhibits cell viability but significantly reduces VEGF gene expression at mRNA and protein levels in both ovarian cancer cell lines. In chorioallantoic membranes of chicken embryos, kaempferol significantly inhibits OVCAR-3-induced angiogenesis and tumor growth. HIF-1α, a regulator of VEGF, is downregulated by kaempferol treatment in both ovarian cancer cell lines. Kaempferol also represses AKT phosphorylation dose dependently at 5 to 20 μM concentrations. ESRRA is a HIF-independent VEGF regulator, and it is also downregulated by kaempferol in a dose-dependent manner. Overall, this study demonstrated that kaempferol is low in cytotoxicity but inhibits angiogenesis and VEGF expression in human ovarian cancer cells through both HIF-dependent (Akt/HIF) and HIF-independent (ESRRA) pathways and deserves further studies for possible application in angio prevention and treatment of ovarian cancers.     

Fisetin Suppresses the Inflammatory Response and Oxidative Stress in Bronchial Epithelial Cells

Fisetin is isolated from many fruits and vegetables and has been confirmed to improve airway hyperresponsiveness in asthmatic mice. However, whether fisetin reduces inflammatory response and oxidative stress in bronchial epithelial cells is unclear. Here, BEAS-2B human bronchial epithelial cells were treated with various concentrations of fisetin and then stimulated with tumor necrosis factor-α (TNF-α) or TNF-α/interleukin-4. In addition, ovalbumin-sensitized mice were treated with fisetin to detect inflammatory mediators and oxidative stress expression. Fisetin significantly reduced the levels of inflammatory cytokines and chemokines in TNF-α-stimulated BEAS-2B cells. Fisetin also attenuated intercellular adhesion molecule-1 expression in TNF-α-stimulated BEAS-2B cells, suppressing THP-1 monocyte adhesion. Furthermore, fisetin significantly suppressed airway hyperresponsiveness in the lungs and decreased eosinophil numbers in the bronchoalveolar lavage fluid of asthmatic mice. Fisetin decreased cyclooxygenase-2 expression, promoted glutathione levels, and decreased malondialdehyde levels in the lungs of asthmatic mice. Our findings indicate that fisetin is a potential immunomodulator that can improve the pathological features of asthma by decreasing oxidative stress and inflammation.