支气管哮喘中气道重构的研究状况

支气管哮喘是由嗜酸粒细胞(EOS)、肥大细胞和T细胞等多种炎性细胞参与的气道慢性炎症性疾病,气道重构是在气道炎症基础上气道壁损伤,在多种细胞、炎症介质、生长因子的参与下出现的不完全修复.本文从病理和发生机制的角度对哮喘的气道重构作一综述.     

呼吸道病毒感染与支气管哮喘气道重构

呼吸道病毒是诱发支气管哮喘（哮喘）急性发作的一个重要原因，病毒感染对气道上皮细胞的损伤有可能参与了哮喘气重构的过程。本文对病毒感染气道上皮细胞诱生的哮喘相关炎前细胞因子，气道纤维化生长因子，及其在它们在气道重构发生发展中的作用作一综述，并探讨了基质金属蛋白酶在其间的作用地位。     

氨茶碱对支气管哮喘气道重塑大鼠肺组织MMP-9及其基因表达的调节

目的 观察氨茶碱对支气管哮喘气道重塑大鼠气道形态学和转化生长因子β1(TGF-β1)、基质金属蛋白酶-9(MMP-9)及其基因表达的调节作用.方法 24只SD大鼠随机分为正常组、模型组、治疗组(35 mg/kg),每组8只,除正常组外以卵蛋白致敏并吸入激发法制备大鼠哮喘模型,治疗组、模型组从第1次哮喘激发开始(第15天)分别给予氨茶碱、生理盐水1次/d灌胃给药,用药4 w后处死大鼠,取肺组织HE染色,彩色图像分析仪测量支气管壁面积、支气管平滑肌面积,采用免疫组化法测定TGF-β1含量,ELISA法测定肺组织MMP-9含量,RT-PCR法测定MMP-9 mRNA含量.结果 与正常组比较,模型组大鼠支气管壁面积、平滑肌面积、肺组织MMP-9含量及MMP-9 mRNA含量明显增加(P＜0.01);与模型组相比,治疗组大鼠支气管壁面积、平滑肌面积、肺组织TGF-β1、MMP-9、MMP-9 mRNA含量均显著降低(P＜0.01).结论 氨茶碱可通过下调哮喘气道重塑大鼠肺组织MMP-9 mRNA表达、抑制MMP-9合成、抑制TGF-β1产生从而抑制支气管哮喘大鼠气道重塑.     

转化生长因子β与支气管哮喘气道重塑

转化生长因子β(TGFB)具有强烈的致纤维化作用,支气管哮喘发病过程中,TGFB表达增高,气道TGFB/EGF(表皮生长因子)失衡,引起成纤维细胞、肌成纤维细胞增生,细胞外基质合成增加、降解减少,导致气道重塑。     

纤维连接蛋白与支气管哮喘气道重构

气道重构（airway remodeling）是支气管哮喘（哮喘）发病的重要特征之一,以往认为,其原因是以气道慢性炎症为基础,它的产生是嗜酸粒细胞参与炎症修复和肥大细胞释放化学介质,对气道黏膜继发性损伤,导致气道壁结构改变,引起肺功能异常的过程.近年来,气道重构在轻度无症状哮喘患者大气道中也被发现,从而对慢性炎症导致气道重构的作用提出质疑.目前认为,哮喘气道重构是气道壁结构改变引起不可逆或部分不可逆的气流阻塞,是诱发气道高反应性和哮喘慢性化的主要原因.其病理学特点包括气道上皮纤维化,平滑肌增生肥大,黏液腺化生和新血管的生长和增生.此外,气道上皮纤维化、管壁弹性减弱和肺弹性回缩力缺失产生持续呼气的气流限制也是导致哮喘慢性化和难治化的重要原因,其机制仍不清楚.现已发现,细胞外基质（ECM）,主要是胶原和纤维连接蛋白（fibronectin,FN）在哮喘气道重构过程中,不仅是在间质中被动的沉积,还是上皮纤维化,包括ECM沉积和气道管壁弹性减弱的主动参与者.本文主要综述了FN在哮喘气道重构发生发展中的作用以及FN发挥生物学效应可能的信号转导途径.     

转化生长因子-β在哮喘气道重构中的作用研究进展

转化生长因子-β(TGF-β)是一个结构相关的生长因子大家族的一员,具有广泛调节细胞增殖、分化和凋亡等生物学功能。肺组织中多种细胞如肺泡巨噬细胞和肺纤维原细胞、上皮细胞、内皮细胞和平滑肌细胞均可合成TGF-β。发作期哮喘患者支气管肺泡灌洗液中以及在中度和重度哮喘患者气道黏膜活检标本中,TGF-β为过度表达。TGF-β可加重气道上皮的损害,刺激成纤维细胞、气道平滑肌细胞增殖,通过促进细胞外基质的合成、诱导结缔组织生长因子表达而导致气道上皮下纤维化,在哮喘的气道重构中具有重要的功能,因此针对TGF-β治疗成为防治哮喘气道重构新的研究方向。     

血管内皮生长因子在支气管哮喘小鼠气道中表达变化及其对气道重构的影响

目的研究血管内皮生长因子（VEGF）在支气管哮喘（哮喘）小鼠气道中表达变化及其对气道重构的影响。方法将40只雌性BALB/c小鼠随机分为4组（每组10只）：生理盐水对照组（A组）;哮喘组（B组）;VEGF受体抑制剂干预组（C组）;地塞米松干预组（D组）。用鸡卵白蛋白致敏和雾化激发建立慢性哮喘小鼠模型。收集小鼠的支气管肺泡灌洗液（BALF）,行白细胞和嗜酸粒细胞（EOS）计数;ELISA法检测BALF和血清中VEGF的水平;用SABC免疫组化法检测VEGF在肺组织的表达水平并行抗Ⅷ因子免疫组化染色在显微镜下计数气管黏膜固有层、黏膜下层血管密度;用逆转录-聚合酶链反应（RT-PCR）方法检测VEGF mRNA的表达变化;采用医学图像分析软件测定支气管管壁厚度（WAt/Pbm）及肺组织切片中的血管数。结果B组BALF中白细胞总数、EOS百分比、VEGF浓度及血清中VEGF浓度明显高于A组,差异有统计学意义（P〈0.01）;C、D两组与B组比较差异均有统计学意义（P〈0.01）,C组与D组比较差异无统计学意义（P〉0.05）。抗Ⅷ因子免疫组化染色及图像分析结果显示：B组气管血管密度、WAt/Pbm及肺组织切片中的血管数明显高于A组（P〈0.01）,C、D两组与B组比较均显著减少（P〈0.01）,C组与D组比较差异无统计学意义（P〉0.05）。免疫组化及RT-PCR检测结果显示：B组小鼠肺组织中的VEGF表达较A组显著增加（P〈0.01）,C、D两组小鼠肺组织中VEGF的表达与B组比较均显著减少（P〈0.01）,C组与D组比较差异无统计学意义（P〉0.05）。结论VEGF在小鼠哮喘模型气道及肺组织内过度表达,参与了哮喘的发病和气道重构的过程,VEGF受体抑制剂可以降低哮喘模型的气道炎症,减轻气道重构的程度。     

支气管哮喘患者气道中白介素17表达与气道重塑关系的研究

目的初步探讨白介素17（interleukin-17,IL-17）在支气管哮喘（简称哮喘）患者气道重塑中的作用。方法选择40例2007年9月至2008年9月在北京市房山区良乡医院呼吸科门诊行气管镜检查的非急性发作期哮喘患者。按肺功能测定结果分为两组。采用免疫细胞化学方法分别检测其支气管肺泡灌洗液中肺泡巨噬细胞及气道上皮细胞的IL-17及转化生长因子β-（TGF-β1）的表达。结果。实验组支气管肺泡灌洗液肺泡巨噬细胞及气道上皮细胞中IL-17表达[（0．3614±0．1896）,（0．3062±0．0136）],较对照组[（0．2061±0．0198）,（0．1957±0．0311）]明显升高,P值均〈0．01,差异均有统计学意义。TGF—β1表达[（0．2801±0．0176）,（0．2743±0．0039）],较对照组[（0．2065±0．0057）,（0．1931±0．0153）]明显升高,P值均〈0．01,差异均有统计学意义。结论 IL-17可能在哮喘气道重塑的发生发展中发挥作用。     

支气管哮喘的气道重构与药物治疗

气道重构是支气管哮喘（哮喘）的特征性病理改变,成为顽固性哮喘的病理基础,直接影响哮喘的治疗效果。因此,研究气道重构的发生机制,探究防治气道重构的方法具有重要意义。     

哮喘小鼠模型中气道重构的变化及地塞米松的干预作用

目的探讨哮喘小鼠模型中气道重构的变化及地塞米松的干预作用。方法将小鼠随机分成正常对照组、哮喘模型组、地塞米松治疗组(DXM组),每组10只。哮喘组和DXM组给予卵蛋白(OVA)致敏并反复雾化吸入OVA 2周、4周,DXM组腹腔注射DXM。各组分别于末次雾化激发后进行取材,收集肺组织,制作石蜡切片,HE染色观察气道中嗜酸性粒细胞;测定单位气道面积基底膜周径(Pbm)、管壁总面积(WAt)、内壁面积(WA i)、平滑肌面积(WAm);用免疫组织化学方法检测肺组织中CTGF表达水平。采用SPSS 13.0软件进行统计分析。结果哮喘模型组WAt/Pbm、WA i/Pbm、WAm/Pbm及CTGF表达显著高于对照组,给予DXM可显著缓解上述指标的升高。结论气道重构在哮喘发病早期即已出现,并随着病程的延长而加重,使用地塞米松可部分抑制气道重构。     

支气管哮喘气道重塑研究进展

支气管哮喘(简称哮喘)是以气道慢性炎症和气道重塑为基本特征的慢性疾病.气道重塑的确切机制尚不清楚,目前认为主要与气道慢性炎症有关,上皮损伤及上皮间充质营养单位再活化在气道重塑发病中也起重要作用.治疗哮喘的传统药物对气道重塑作用有限,近年应用抗肿瘤坏死因子α、CpG-ODN、抗IgE抗体和抗Th2细胞因子等免疫调节剂治疗气道重塑,支气管热整形术是有创性治疗技术.     

细胞因子在支气管哮喘气道重塑中作用的研究现状

支气管哮喘（简称哮喘）是一种常见的呼吸道疾病,其发病率在全球范围内呈逐年增加趋势,严重影响患者的健康。气道重塑是哮喘的重要特征,是引起哮喘不可逆气流阻塞、难治性哮喘和激素抵抗的重要原因之一。     

Mechanisms of airway remodeling in asthma.

Asthma is a chronic inflammatory disease characterized by reversible airflow limitation and airway hyperresponsiveness. Persistent inflammation in airway tissues may lead to structural changes known as airway remodeling and consequently airway obstruction that is not fully reversible and progressive loss of lung function over time. It is generally accepted that airway remodeling is closely related to progression of airway hyperresponsiveness, and the severity of asthma. The structural changes observed in chronic persistent asthma, which includes airway smooth muscle hypertrophy and hyperplasia, collagen deposition to sub-epithelial basement membrane, hyperplasia of goblet cells, thickening of airway mucosa and an increase in vascularity, are derived from airway inflammation. For instance, the thickened airway mucosa might be produced by cytokines and growth factors released from inflammatory cells and airway epithelial cells, and associated with bronchial hyperreactivity and asthma severity. To date, many studies have identified candidate mechanisms and mediators for these observed structural changes, which are thus potential targets in the treatment of asthma. In this review, we describe the recent knowledge of the mechanisms and clinical implications of airway remodeling in asthma.     

Structural aspects of airway remodeling in asthma

Airway remodeling in asthma is a complex process that involves structural changes in virtually all tissues of the airway wall. The histologic changes to the airways consist of epithelial proliferation and goblet cell differentiation, subepithelial fibrosis, airway smooth muscle (ASM) growth, angiogenesis, matrix protein deposition, gland hyperplasia and hypertrophy, and nerve proliferation. Cytokines, chemokines, and growth factors from inflammatory cells and structural cells contribute to remodeling. There are complex interactions among the various signaling pathways involving matrix metalloproteinases that are required for growth factor release. The physiologic consequences of remodeling are airway hyperresponsiveness from ASM growth and mucus hypersecretion from gland and goblet cell hyperplasia. Airway stiffening is a probable contributor to airway hyperresponsiveness through attenuation of the transmission of potently bronchodilating cyclical stress to the ASM during breathing. The epidermal growth factor receptor’s role in remodeling and its interaction with other potential causes of remodeling are discussed.     

咳嗽变异性哮喘与气道重塑

咳嗽变异性哮喘（coughvariantasthma,CVA）是指以慢性咳嗽为主要或唯一症状的一种特殊类型哮喘,其病理生理改变与典型哮喘相同,若未及时诊治,约30％～40％可发展成为典型哮喘。气道炎细胞浸润和气道重塑是CVA的病理基础。CVA可称之为一种隐匿性哮喘,常被临床医师所忽略,患者失去正确的诊断与治疗。正确认识CVA的病理生理特征,对临床诊断和治疗具有重要的指导意义,可降低典型哮喘的发病率。本文就CVA与气道炎性反应和气道重塑的关系作一综述。     

Fractal geometry of airway remodeling in human asthma

RATIONALE: Airway wall remodeling is an important aspect of asthma. It has proven difficult to assess quantitatively as it involves changes in several components of the airway wall. OBJECTIVE: To develop a simple method for quantifying the overall severity of airway wall remodeling in asthmatic airways using fractal geometry. METHODS: Negative-pressure silicone rubber casts of lungs were made using autopsy material from three groups: fatal asthma, nonfatal asthma, and nonasthma control. All subjects were lifelong nonsmokers. A fractal dimension was calculated on two-dimensional digital images of each cast. RESULTS: Nonasthma control casts had smooth walls and dichotomous branching patterns with nontapering segments. Asthmatic casts showed many abnormalities, including airway truncation from mucous plugs, longitudinal ridges, and horizontal corrugations corresponding to elastic bundles and smooth muscle hypertrophy, respectively, and surface projections associated with ectatic mucous gland ducts. Fractal dimensions were calculated from digitized images using an information method. The average fractal dimensions of the airways of both the fatal asthma (1.72) and nonfatal asthma (1.76) groups were significantly (p<0.01 and p=0.032, respectively) lower than that of the nonasthma control group (1.83). The lower fractal dimension of asthmatic airways correlated with a decreased overall structural complexity and pathologic severity of disease. CONCLUSION: Fractal analysis is a simple and useful technique for quantifying the chronic structural changes of airway remodeling in asthma.     

Toll样受体与支气管哮喘气道重塑

气道重塑是除气道慢性炎症以外支气管哮喘的又一重要特征.近年来研究表明,Toll样受体可通过调节多种致气道重塑因子如生长因子、细胞因子、炎性介质、趋化因子等的生成和活化,最终导致气道重塑.     

The regulation of fibrosis in airway remodeling in asthma

Fibrosis is one of the key pathological features of airway remodeling in asthma. In the normal airway the amount of collagen and other extracellular matrix components is kept in equilibrium by regulation of synthesis and degradation. In asthma this homeostasis is disrupted due to genetic and environmental factors. In the airways of patients with the disease there is increased extracellular matrix deposition, particularly in the reticular basement membrane region, lamina propria and submucosa. Fibrosis is important as it can occur early in the pathogenesis of asthma, be associated with severity and resistant to therapy. In this review we will discuss current knowledge of relaxin and other key regulators of fibrosis in the airway including TGFβ, Smad2/3 and matrix metalloproteinases. As fibrosis is not directly targeted or effectively treated by current asthma drugs including corticosteroids, characterization of airway fibrosis and how it is regulated will be essential for the development of novel therapies for asthma.