动态观察过敏原诱导的哮喘小鼠模型从急性炎症到慢性重塑的发展

目的:动态观察对比卵白蛋白(OVA)诱导的哮喘小鼠模型从气道的急性炎症到慢性重塑的相关炎症指标及气道重塑指标的变化。方法:60只雌性BALB/c小鼠随机分为正常对照组和哮喘组。哮喘组给予OVA致敏和激发,正常对照组给予等量生理盐水(NS)作为对照,第21天开始,连续激发3 d,观察急性炎症反应;而后每周激发1次、每次激发后24 h内取材1次连续5周;动态观察对比OVA激发组和NS对照组小鼠气道炎症细胞的浸润情况、灌洗液细胞因子水平和气道重塑相关指标。结果:与NS组比较,OVA组肺组织的炎症细胞浸润明显,炎症因子升高;气道上皮细胞向杯状细胞转化明显;支气管外周胶原沉积显著。OVA组内比较,24 d组炎症细胞和炎症因子上升明显,而上皮细胞向杯状细胞的转化以及支气管外周胶原沉积相关重塑指标不明显,52 d组上皮细胞向杯状细胞的转化以及支气管外周胶原沉积相关重塑指标最为显著,而炎症细胞和炎症因子有所下降。结论:连续3次OVA激发可成功模拟炎症细胞和炎症因子显著的急性哮喘模型;每周1次、连续5周的OVA激发方式可成功模拟重塑明显的慢性哮喘模型。     

Targeted inhibition of GATA-6 attenuates airway inflammation and remodeling by regulating caveolin-1 through TLR2/MyD88/NF-κB in murine model of asthma

The purpose of this study was to evaluate the effects of GATA-6 on airway inflammation and remodeling and the underlying mechanisms in a murine model of chronic asthma. Female BALB/c mice were randomly divided into four groups: phosphate-buffered saline control (PBS), ovalbumin (OVA)-induced asthma group (OVA), OVA+ siNC and OVA+ siGATA-6. In this mice model, GATA-6 expression level was significantly elevated and the expression in Caveolin-1 (Cav-1) inversely correlated with the abundance of GATA-6 in OVA-induced asthma of mice. Silencing of GATA-6 gene expression upregulated Cav-1 expression. Additionally, downregulation of GATA-6 dramatically decreased OVA-challenged inflammation, infiltration, and mucus production. Moreover, silencing of GATA-6 resulted in decreased levels of immunoglobulin E (IgE) and inflammatory mediators and reduced inflammatory cell accumulation, as well as inhibiting the expression of important mediators including matrix metalloproteinase (MMP)-2 and MMP-9, TGF-β1, and a disintegrin and metalloproteinase 8 (ADAM8) and ADAM33, which is related to airway remodeling. Further analysis confirmed that silencing of GATA-6 attenuated OVA-induced airway inflammation and remodeling through the TLR2/MyD88 and NF-κB pathway. In conclusion, these findings indicated that the downregulation of GATA-6 effectively inhibited airway inflammation and reversed airway remodeling via Cav-1, at least in part through downregulation of TLR2/MyD88/NF-κB, which suggests that GATA-6 represents a promising therapeutic strategy for human allergic asthma.     

Toll样受体4/核因子-κB对哮喘大鼠气道炎症和重构的影响

目的: 探讨TLR4/NF-κB对哮喘大鼠气道炎症和气道重构的影响。方法: 将18只SD大鼠随机分成3组:对照组、哮喘4周组和哮喘8周组,每组6只。造模成功后,利用HE染色、免疫组织化学方法及病理图像分析系统分析大鼠气道平滑肌的嗜酸性粒细胞(EOS)浸润情况、气道壁厚度以及增殖细胞核抗原(PCNA)和Bcl-2的蛋白表达量。利用RT-PCR和Western blotting检测ASM中TLR4和NF-κB的mRNA及蛋白表达。结果: 哮喘4周组和哮喘8周组的气道壁EOS计数、气道壁厚度、气道反应性均较正常对照组显著增加(P<0.01);哮喘4周组和哮喘8周组的TLR4及NF-κB的mRNA水平和蛋白表达与对照组比较均显著增加(P<0.01);TLR4及NF-κB的mRNA水平随哮喘天数的增加而显著增加(P<0.01);哮喘4周组、哮喘8周组PCNA和Bcl-2的蛋白表达量均显著高于正常对照组(P<0.01);哮喘两组间上述指标差异显著(P<0.05或P<0.01)。结论: TLR4/NF-κB可能参与哮喘大鼠气道炎症和气道重构的调控。     

Human TSLP and TLR3 ligands promote differentiation of Th17 cells with a central memory phenotype under Th2-polarizing conditions

Background Human thymic stromal lymphopoietin (TSLP) is expressed in the human asthmatic lung and activates dendritic cells (DCs) to strongly induce proallergic T‐helper type 2 (Th2) cell responses, suggesting that TSLP plays a critical role in the pathophysiology of human asthma. Th2 cells are predominantly involved in mild asthma, whereas a mixture of Th1 and Th2 cells with neutrophilic inflammation, probably induced by Th17, affects more severe asthmatic disease. Exacerbation of asthmatic inflammation is often triggered by airway‐targeting RNA viral infection; virus‐derived double‐stranded RNA, Toll‐like receptor (TLR)3 ligand, activates bronchial epithelial cells to produce pro‐inflammatory mediators, including TSLP. Objective Because TSLPR‐expressing DCs express TLR3, we examined how the relationship between TSLP and TLR3 ligand stimulation influences DC activation. Methods CD11c⁺DCs purified from adult peripheral blood were cultured in TLR ligands containing media with or without TSLP and then co‐cultured with allogeneic naïve CD4⁺T cells. Results CD11c⁺ DCs responded to a combination of TSLP and TLR3 ligand, poly(I : C), to up‐regulate expression of the functional TSLP receptor and TLR3. Although TSLP alone did not induce IL‐23 production by DCs, poly(I : C) alone primed DCs for the production of IL‐23, and a combination of TSLP and poly(I : C) primed DCs for further production of IL‐23. The addition of poly(I : C) did not inhibit TSLP‐activated DCs to prime naïve CD4⁺ T cells to differentiate into inflammatory Th2 cells. Furthermore, DCs activated by a combination of TSLP and poly(I : C) primed more naïve CD4⁺ T cells to differentiate into Th17‐cytokine–producing cells with a central memory T cell phenotype compared with DCs activated by poly(I : C) alone. Conclusions These results suggest that through DC activation, human TSLP and TLR3 ligands promote differentiation of Th17 cells with the central memory T cell phenotype under Th2‐polarizing conditions.     

The TLR4–TRIF pathway can protect against the development of experimental allergic asthma

The Toll‐like receptor (TLR) adaptor proteins myeloid differentiating factor 88 (MyD88) and Toll, interleukin‐1 receptor and resistance protein (TIR) domain‐containing adaptor inducing interferon‐β (TRIF) comprise the two principal limbs of the TLR signalling network. We studied the role of these adaptors in the TLR4‐dependent inhibition of allergic airway disease and induction of CD4⁺ ICOS⁺ T cells by nasal application of Protollin™, a mucosal adjuvant composed of TLR2 and TLR4 agonists. Wild‐type (WT), Trif^−/− or Myd88^−/− mice were sensitized to birch pollen extract (BPEx), then received intranasal Protollin followed by consecutive BPEx challenges. Protollin's protection against allergic airway disease was TRIF‐dependent and MyD88‐independent. TRIF deficiency diminished the CD4⁺ ICOS⁺ T‐cell subsets in the lymph nodes draining the nasal mucosa, as well as their recruitment to the lungs. Overall, TRIF deficiency reduced the proportion of cervical lymph node and lung CD4⁺ ICOS⁺ Foxp3⁻ cells, in particular. Adoptive transfer of cervical lymph node cells supported a role for Protollin‐induced CD4⁺ ICOS⁺ cells in the TRIF‐dependent inhibition of airway hyper‐responsiveness. Hence, our data demonstrate that stimulation of the TLR4‐TRIF pathway can protect against the development of allergic airway disease and that a TRIF‐dependent adjuvant effect on CD4⁺ ICOS⁺ T‐cell responses may be a contributing mechanism.     

MIF is essential to the establishment of house dust mite-induced airway inflammation and tissue remodeling in mice

Macrophage migration inhibitory factor (MIF) is present in high amounts in the BALF and serum of asthmatic patients, contributing to the pathogenesis of experimental asthma induced by OVA in mice. Whether MIF contributes to the physiopathology on a more complex and relevant asthma model has not been characterized. Mif-deficient (Mif^−/−) or WT mice treated with anti-MIF antibody were challenged multiple times using house dust mite (HDM) extract by the intranasal route. HDM-challenged Mif^−/− mice presented decreased airway hyperresponsiveness, lung infiltration of eosinophils, mucus hypersecretion, and subepithelial fibrosis compared to HDM-challenged WT mice. Amounts of IL-4, IL-5, and IL-13 were decreased in the lungs of Mif^−/− mice upon HDM challenges, but the increase of CCL11 was preserved, compared to HDM-challenged WT mice. We also observed increased numbers of group 2 innate lymphoid cells and Th2 cells in the BALF and mediastinal LNs (mLN)-induced challenged by HDM of WT mice, but not in HDM-challenged Mif^−/− mice. Anti-MIF treatment abrogated the airway infiltration of eosinophils, mucus hypersecretion, and subepithelial fibrosis in the lungs of HDM-challenged mice. In conclusion, MIF ablation prevents the pathologic hallmarks of asthma in HDM-challenged mice, reinforcing the promising target of MIF for asthma therapy.     

TLR4/PI3K信号相关分子在气道上皮细胞诱导的哮喘气道平滑肌细胞迁移功能中的作用

目的 探讨TLR4、PI3K和NF-kB在气道上皮细胞诱导的哮喘气道平滑肌细胞(airway smooth muscle cells,ASMCs)迁移中的作用.方法 细胞消化法培养原代哮喘ASMCs,TNF-α刺激上皮细胞系RTE细胞收集细胞培养上清液,ELISA检测上清液中IL-8和RANTES的含量,以TLR4抗体、渥曼青霉素(Wortmannin)、二硫代氨基吡咯烷(PDTC)作为工具药,改良Boyden趋化小室检测其在上皮细胞诱导的哮喘ASMCs跨膜迁移中的作用.结果 各TNF-α组RTE培养上清液中IL-8和RANTE水平均显著增高(P＜0.01),20 ng/ml组较其他组显著增高(P＜0.01).各哮喘组ASMCs的跨膜迁移数较正常组均显著增加(P＜0.01),各处理组哮喘ASMCs的跨膜迁移数亦较哮喘组明显增加(P＜0.01),TNF-α+TLR4抗体组、TNF-α +Wortmannin组和TNF-α+Wortmannin+PDTC组哮喘ASMCs跨膜迁移数较TNF-α组明显减少(P＜0.01);TNF-α+Wortmannin +PDTC组ASMCs跨膜迁移数亦低于Wortmannin组(P＜0.05).结论 TLR4/PI3K信号相关分子参与哮喘气道上皮细胞诱导的ASMCs跨膜迁移,可能是哮喘气道重塑的机制之一.     

A CCL24-dependent pathway augments eosinophilic airway inflammation in house dust mite-challenged Cd163−/− mice

CD163 is a macrophage scavenger receptor with anti-inflammatory and pro-inflammatory functions. Here, we report that alveolar macrophages (AMΦs) from asthmatic subjects had reduced cell-surface expression of CD163, which suggested that CD163 might modulate the pathogenesis of asthma. Consistent with this, house dust mite (HDM)-challenged Cd163^−/− mice displayed increases in airway eosinophils and mucous cell metaplasia (MCM). The increased airway eosinophils and MCM in HDM-challenged Cd163^−/− mice were mediated by augmented CCL24 production and could be reversed by administration of a neutralizing anti-CCL24 antibody. A proteomic analysis identified the calcium-dependent binding of CD163 to Dermatophagoides pteronyssinus peptidase 1 (Der p1). Der p1-challenged Cd163^−/− mice had the same phenotype as HDM-challenged Cd163^−/− mice with increases in airway eosinophils, MCM and CCL24 production, while Der p1 induced CCL24 secretion by bone marrow-derived macrophages (BMMΦs) from Cd163^−/− mice, but not BMMΦs from wild-type (WT) mice. Finally, airway eosinophils and bronchoalveolar lavage fluid CCL24 levels were increased in Der p1-challenged WT mice that received adoptively transferred AMΦ's from Cd163^−/− mice. Thus, we have identified CD163 as a macrophage receptor that binds Der p1. Furthermore, we have shown that HDM-challenged Cd163^−/− mice have increased eosinophilic airway inflammation and MCM that are mediated by a CCL24-dependent mechanism.     

Trif-dependent induction of Th17 immunity by lung dendritic cells

Allergic asthma is thought to stem largely from maladaptive T helper 2 (Th2) responses to inhaled allergens, which in turn lead to airway eosinophilia and airway hyperresponsiveness (AHR). However, many individuals with asthma have airway inflammation that is predominantly neutrophilic and resistant to treatment with inhaled glucocorticoids. An improved understanding of the molecular basis of this form of asthma might lead to improved strategies for its treatment. Here, we identify novel roles of the adaptor protein, TRIF (TIR-domain-containing adapter-inducing interferon-β), in neutrophilic responses to inhaled allergens. In different mouse models of asthma, Trif-deficient animals had marked reductions in interleukin (IL)-17, airway neutrophils, and AHR compared with wild-type (WT) mice, whereas airway eosinophils were generally similar in these two strains. Compared with lung dendritic cells (DCs) from WT mice, lung DCs from Trif-deficient mice displayed impaired lipopolysaccharide (LPS)-induced migration to regional lymph nodes, lower levels of the costimulatory molecule, CD40, and produced smaller amounts of the T helper 17 (Th17)-promoting cytokines, IL-6, and IL-1β. When cultured with allergen-specific, naive T cells, Trif-deficient lung DCs stimulated robust Th2 cell differentiation but very weak Th1 and Th17 cell differentiation. Together, these findings reveal a TRIF-CD40-Th17 axis in the development of IL-17-associated neutrophilic asthma.     

1,25-二羟维生素D_3减轻哮喘小鼠的气道重塑

目的探讨1,25-二羟维生素D3(1,25(OH)2D3,VD)对哮喘小鼠气道重塑及其肺组织中基质金属蛋白酶-9(MMP-9)表达的干预作用及其机制。方法建立慢性哮喘小鼠模型,将小鼠随机分为对照组、哮喘组、地塞米松(DEX)组及VD组。HE染色观察各组气道结构;用计算机图像分析系统评价各组气道重塑;用明胶酶谱法及RT-PCR法检测各组的MMP-9的活性及其mRNA表达。结果 (1)哮喘组出现炎性细胞浸润增多、上皮细胞脱落及平滑肌细胞层增厚等气道重塑改变,而DEX组及VD组均可部分逆转上述病理改变;(2)DEX组及VD组的支气管内壁厚度、平滑肌层厚度和平滑肌细胞核数显著低于哮喘组,但仍高于对照组(P<0.05);(3)DEX组及VD组肺组织MMP-9的活性分别为对照组的(2.24±0.16)倍及(3.46±0.09)倍,而哮喘组是对照组的(7.87±0.09)倍(P<0.05);(4)各组MMP-9mRNA相对定量分别为对照组(0.57±0.08)、哮喘组(5.74±0.13)、DEX组(2.63±0.11)及VD组(3.16±0.09),且两两比较均P<0.05。结论 1,25(OH)2D3可显著减轻哮喘气道...     

The different functions of short and long thymic stromal lymphopoietin isoforms in autophagy-mediated asthmatic airway inflammation and remodeling

Asthma is a chronic respiratory disease characterized by airway inflammation and remodeling as well as hyper-responsiveness. Thymic stromal lymphopoietin (TSLP), which is a crucial inflammatory cytokine in immune homeostasis, consists of two isoforms, the long isoform lfTSLP and short isoform sfTSLP. The lfTSLP promotes inflammation and plays a pivotal role in asthma pathogenesis, while sfTSLP had been reported to have anti-asthma effects. Experiments have shown that lfTSLP could induce autophagy in hepatocytes. It is unknown whether lfTSLP or sfTSLP could influence autophagy and affect the progression of asthma. Using house dust mite (HDM)-stimulated airway smooth muscle cells as an in vitro model and HDM-induced asthma mice as in vivo model, we found that lfTSLP could induce autophagy and remodeling, while sfTSLP has the reverse effect. Strikingly, sfTSLP treatment in vivo reversed HDM-mediated activation of inflammation and airway remodeling, partly determined by autophagy change. These findings may help us understand the function of TSLP isoforms in the pathogenesis of asthma, and they support the use of drugs targeting sfTSLP and TSLP for asthma treatment.     

细胞周期蛋白E在哮喘大鼠肺组织中的表达及其与气道重塑的关系

目的:通过测定哮喘大鼠肺组织中细胞周期蛋白E(cyclin E)的表达,研究cyclin E在哮喘气道重塑中的作用。方法:20只Wistar大鼠随机分为哮喘组和对照组,每组10只。用鸡卵清白蛋白(OVA)溶液致敏及激发复制哮喘模型。HE染色观察气道炎症;图像分析测量气道管壁厚度;流式细胞仪测定外周血单个核细胞细胞周期时相分布;免疫组化法检测cyclin E的表达情况;实时定量(real-time)RT-PCR测定肺组织中cyclin E mRNA水平表达;Western blotting法检测肺组织中cyclin E蛋白的表达。结果:哮喘组大鼠支气管管壁厚度较对照组增加(P0.01);哮喘组外周血单个核细胞S期、S+G2/M期百分率均较对照组增加,而G0/G1期百分率较对照组降低(均P0.01);哮喘组肺组织中cyclin E mRNA和蛋白水平的相对表达量较对照组高(均P0.01);肺组织中cyc-lin E蛋白的相对表达量与支气管管壁厚度呈正相关(P0.01)。结论:Cyclin E在哮喘大鼠肺组织中表达增加,其表达的上调可使细胞周期的G1期缩短,进而可能通过促进细胞的分裂增殖而参与哮喘气道重塑的发生发展。     

Dok adaptors play anti‐inflammatory roles in pulmonary homeostasis

Asthma is a chronic inflammatory disease of the lung with airflow obstruction and bronchospasm, characterized by pulmonary eosinophilia, airway remodeling, increased airway hyperresponsiveness to environmental stimuli, and excessive Th2‐type cytokine production. Recent studies indicate that crosstalk between the innate and adaptive immune systems is crucial for this disease. We and others have showed that the Dok (downstream of tyrosine kinases) family adaptors, Dok‐1, Dok‐2, and Dok‐3, play essential roles in negative regulation of a wide variety of signaling pathways in both innate and adaptive immunities. Here, histopathology and bronchoalveolar lavage fluid (BALF) cellularity showed spontaneous pulmonary inflammation in Dok‐1^−/−Dok‐2^−/−Dok‐3^−/− (TKO) mice, but not in Dok‐1^−/−Dok‐2^−/− or Dok‐3^−/− mice, with hallmarks of asthma, including eosinophilia, goblet cell hyperplasia, and subepithelial fibrosis. Consistently, TKO mice, but not the other mutants, showed increased airway hyperresponsiveness to methacholine inhalation. In addition, Th2‐type cytokine concentrations in BALF were increased in TKO mice. These findings provide strong evidence that Dok‐1, Dok‐2, and Dok‐3 cooperatively play critical anti‐inflammatory roles in lung homeostasis.     

Effect of Lactobacillus rhamnosus GG immunopathologic changes in chronic mouse asthma model

BackgroundAsthma is a heterogeneous inflammatory disorder of the airway. A Th2 response usually contributes to high levels of allergen-specific IgE and eosinophilic airway inflammation. Several findings have demonstrated that neutrophils, not eosinophils, are the major inflammatory cells in chronic asthma patients with steroid-resistance. Lactobacillus rhammosus GG (LGG) exhibits anti-inflammatory properties on OVA-induced acute airway inflammation.ObjectiveWe hypothesized that orally administrated LGG should reduce airway remodeling in chronic experimental models.MethodsFemale Balb/c mice were sensitized with OVA. LGG was used to investigate whether oral administrations of LGG inhibited OVA-induced airway inflammation in a chronic asthma model and the different intervention times between LGG pre-treatment and post-treatment groups. BALF was analyzed with Liu's stain and ELISA assay. Lung histopathology was assayed with HE, IHC and Masson's trichrome staining. Lung tissues were assayed with PCR (T-bet, GATA3, RORrt and Foxp3). Many cytokines were detected in the serum and BALF.ResultsLGG significantly decreased the number of infiltrating inflammatory cells. We also found that the oral LGG group suppressed not only Th2 cytokine, but also IL-17, TNF-α and HMGB1 in the BALF levels. However, GATA3 and RORrt decreased significantly in the RNA level in the LGG groups, but the T-bet and Foxp3 increased in the RNA level.ConclusionsLGG not only had anti-inflammatory effects on OVA-induced airway inflammation, but also improved airway remodeling and collagen expression in the chronic asthma mouse model. Moreover, LGG might be an additional or supplementary therapy for allergic airway diseases.     

Tissue inhibitor of metalloproteinase-1 modulates allergic lung inflammation in murine asthma

Matrix metalloproteinases (MMPs) modulate development, inflammation, and repair in lungs. Tissue inhibitors of MMPs (TIMPs) interact with MMPs, controlling the intensity and nature of the response to injury. Absence of MMP-9, -2, and -8 activities is associated with altered lung inflammation during allergic sensitization. To test the hypothesis that the absence of TIMP-1 enhances allergic lung inflammation, airway hyperreactivity (AHR), and lung remodeling in asthma, we studied TIMP-1 null (TIMP-1 KO) mice and their WT controls using an ovalbumin (OVA) asthma model. TIMP-1 KO mice, compared to WT controls, developed an asthma phenotype characterized by AHR, pronounced cellular lung infiltrates, greater reduction in lung compliance, enhanced Th2 cytokine mRNA and protein expression, and altered collagen lung content associated with enhanced MMP-9 activity. Our findings support the hypothesis that TIMP-1 plays a protective role by preventing AHR and modulating inflammation, remodeling, and cytokine expression in an animal model of asthma.     

CpG-oligodeoxynucleotides inhibit airway remodeling in a murine model of chronic asthma

BACKGROUND: We have previously demonstrated that CpG oligodeoxynucleotides (CpG-ODNs) protect against eosinophilia and airway hyperresponsiveness in murine models of allergen-induced asthma. Acute inflammation is hypothesized to induce chronic airway responses, but no previous studies have evaluated the effects of CpG-ODNs on allergen-induced airway remodeling. Because remodeling is thought to be responsible for many of the long-term adverse effects on asthmatic patients, we evaluated whether CpG-ODNs might similarly prevent these changes using a murine model of recurrent allergen exposure. OBJECTIVE: The purpose of this study was to evaluate the effect of CpG-ODNs on chronic inflammatory changes and airway remodeling by using a murine model of chronic allergen-induced asthma. METHODS: C57BL/6 mice were sensitized to ovalbumin (OVA) and subsequently exposed to nebulized OVA by means of inhalation 3 times weekly for 6 weeks. Some mice received CpG-ODNs by means of intraperitoneal injection at the time of sensitization. At the end of the exposure period, mice were evaluated for the development of airway inflammation, airway hyperresponsiveness, and airway remodeling. RESULTS: OVA-sensitized mice exposed to recurrent airway challenge with OVA have chronic inflammation, persistent airway hyperresponsiveness, and evidence of airway remodeling, including subepithelial collagen deposition and goblet cell hyperplasia-metaplasia. These changes are significantly reduced in mice treated with CpG-ODNs. Interestingly, mice treated with CpG-ODNs exhibit increased levels of bronchoalveolar lavage transforming growth factor beta, suggesting that regulatory T cells might be responsible for some of these protective effects. CONCLUSION: CpG-ODNs are effective not only in preventing acute inflammation but also appear to reduce markers of airway remodeling that develop after chronic allergen exposure.     

雾化吸入灭活草分支杆菌减轻哮喘小鼠气道炎症及对Toll样受体2表达的影响

目的研究雾化吸入灭活草分支杆菌对支气管哮喘小鼠气道炎症及肺组织细胞因子分泌的影响,探讨Toll样受体2(TLR2)表达在雾化吸入灭活草分支杆菌防治支气管哮喘中的作用。方法将24只雄性Balb/c小鼠按随机数字表法分为3组,每组8只:正常对照组(A)、哮喘模型组(B)、干预组(C)。卵清蛋白(OVA)致敏制小鼠支气管哮喘模型。C组在每次卵蛋白激发前给予雾化吸入草分枝杆菌治疗,每天1次。各组动物处死后提取肺组织和支气管肺泡灌洗液(BALF)。进行病理HE染色、AB-PAS染色观察支气管肺炎症和气道粘液分泌情况,并行半定量分析。BALF中炎症细胞计数,检测BALF中IL-4、IL-10、IFN-γ水平。实时定量PCR检测肺组织TLR2 mRNA表达水平。结果干预组BALF中IL-4分泌减少,IL-10、IFN-γ增加(P<0.05),BALF中嗜酸性粒细胞比例低于模型组,气道炎症病变较模型组减轻,肺组织TLR2 mRNA表达水平较模型组显著升高(P<0.05)。结论吸入草分枝杆菌能减轻支气管哮喘小鼠气道炎症,其效应与调节肺内细胞因子分泌有关。草分枝杆菌可能通过上调TLR2基因的表达调节支气管哮喘的免疫失衡。     

Potential Masking of Airway Eosinophilic Inflammation by Combination Therapy in Asthma

Purpose

Long-acting β₂ agonists (LABA) may mask ongoing bronchial inflammation, leaving asthmatic patients at greater risk of severe complications. The aim of this study was to compare the effect of combination therapy using low-dose inhaled corticosteroids (ICS) plus LABA on airway inflammation in asthma to the effect of medium-dose ICS alone.

Methods

Twenty-four patients with asthma not controlled by low-dose (400 µg per day) budesonide alone were enrolled in this prospective crossover study. Patients were randomized into 2 treatment phases: one receiving medium-dose (800 µg per day) budesonide (ICS phase), and the other receiving a combination therapy of low-dose budesonide/formoterol (360 µg/9 µg per day) delivered by a single inhaler (LABA phase). Each treatment phase lasted for 6 week, after which patients were crossed over. Asthma symptoms, lung function, and airway inflammation were compared between the 2 phases.

Results

Twenty-three patients completed the study; adequate sputum samples were collected from 17 patients. Asthma symptoms and lung function remained similar between the 2 phases. However, the mean sputum eosinophil percentage was higher in the LABA phase than in the ICS phase (5.07±3.82% vs. 1.02±1.70%; P<0.01). Sputum eosinophilia (≥3%) was more frequently observed in the LABA phase than in the ICS phase (six vs. two).

Conclusion

Addition of LABA may mask airway eosinophilic inflammation in asthmatic patients whose symptoms are not controlled with low-dose ICS.     

T-bet基因转染对哮喘小鼠气道炎症的影响

目的： 观察气道内T-bet基因转染对哮喘小鼠气道炎症的影响。方法: C57BL/6小鼠40只,随机分为4组,每组10只,分别为正常对照组（A组）、哮喘模型组（B组）、空质粒干预组(C组) 和T-bet质粒干预组(D组)。卵白蛋白(OVA) 抗原溶液腹腔注射致敏,滴鼻造模。正常对照组用生理盐水代替OVA,空质粒干预组和T-bet质粒干预组OVA激发48 h前,分别经鼻滴入50 μg空质粒和重组T-bet质粒。观察各组实验小鼠的肺组织炎症以及BALF中各类炎症细胞以及IL-4、IFN-γ水平的变化。 结果: Western blotting检测发现,小鼠气道转染pcDNA3-T-bet质粒48 h后肺组织T-bet蛋白表达显著增加。pcDNA3-T-bet质粒转染能较好抑制给药后48 h OVA激发的哮喘小鼠气道炎症（包括炎症细胞浸润,上皮细胞损伤、黏液分泌、血管壁水肿及管腔缩窄）;下调小鼠BALF中Th2因子IL-4并上调Th1因子IFN-γ水平。 结论: 气道内转染T-bet质粒能有效改善哮喘小鼠的气道炎症。