水通道蛋白敲除对支气管哮喘小鼠气道黏蛋白谱表达的影响

目的水通道蛋白5（aquaporin5,AQP5）敲除对支气管哮喘（简称哮喘）小鼠气道黏蛋白（MUC）谱表达的影响。方法用卵白蛋白致敏和激发制备AQP5敲除鼠的哮喘高分泌模型。用苏木精-伊红染色观察气道及血管周围炎性细胞浸润。阿辛兰-过碘酸雪夫检测显示气道上皮细胞总黏液分泌,免疫组织化学检测气道上皮MUC5AC,MUC5B,MUC2的表达情况。结果哮喘小鼠气道和血管周围可见大量中性粒细胞,淋巴细胞和嗜酸粒细胞浸润,气道上皮有大量的紫红色中性黏液分布,其中以AQP5敲除鼠总黏液分布更多。免疫组织化学显示小鼠哮喘高分泌模型中MUC谱主要为MUC5AC和MUC5B,未见MUC2分布。与野生型哮喘小鼠比较,MUC5AC、MUC5B在AQP5敲除鼠中表达更丰富。结论AQP5基因缺失可能使小鼠气道对过敏原的应激性提高,从而促进黏液高分泌。     

低分子肝素对哮喘小鼠气道黏液高分泌和炎症反应的影响

目的探讨低分子肝素对哮喘小鼠气道黏液高分泌和炎症反应的影响。方法 30只健康雄性C57BL/6小鼠,按随机数字表法分为正常对照组、哮喘组和低分子肝素干预组,每组10只,检测三组小鼠气道上皮细胞黏液分泌量、气道内炎症细胞浸润、黏蛋白基因MUC5AC的表达、细胞因子IL-13、IL-4和IL-5的表达。结果 (1)哮喘小鼠气道黏液细胞化生、黏液过度分泌,气道内炎症细胞浸润增多,经鼻腔滴入低分子肝素后,黏液过度分泌受抑制,气道内炎症细胞浸润减少。(2)哮喘组小鼠气道黏液细胞MUC5AC mRNA相对表达量(26.43±0.47)及气道内炎症因子IL-13[(16.03±0.53)ng/ml]、IL-4[(603.68±50.32)pg/ml]和IL-5[(1308.80±224.84)pg/ml]表达的水平均高于正常组[(1.17±0.18)ng/ml、(17.56±3.01)pg/ml和(33.09±5.92)pg/ml];经鼻腔滴入低分子肝素后,上述指标[16.26±2.07,(11.50±0.89)ng/ml,(409.56±46.25)pg/ml,(874.65±32.833)pg/ml]均下降,P0.05,差异有统计学意义。结论低分子肝素抑制哮喘小鼠气道黏液高分泌和气道炎症反应。经鼻滴入的低分子肝素可能为哮喘过敏性炎症的治疗提供新的方法。     

MUC5AC与气道黏液高分泌

正常状态下,气道上皮黏液细胞和黏液腺在黏蛋白基因MUC2调控下分泌少量黏液,以维持气道的正常功能;而各种病理状态下的气道黏液高分泌则主要源于黏蛋白基因MUC5AC的高表达.MUC5AC高表达,使气道黏液分泌增加、黏稠性提高,加重气道阻塞.目前针对黏液高分泌缺乏有效治疗手段,故调控MUC5AC表达,有利于控制病理状态下气道黏液的高分泌,改善临床症状.

Abstract：

Airway epithelial mucous cells and mucous glands under the airway epithelium secret small amounts of mucus which is modulated by MUC2, but over production of mucus are mainly modulated by MUC5AC under pathological conditions. Expression of MUC5AC makes the airway mucus hypersecretion, vicidity improved, aggravates airway obstruction. It is deficiency in overcoming mucus hypersecreion so far. Thus, the modulation of MUC5AC is of significance in both mucus hypersecretions and improvements of clinical symptoms.     

白细胞介素-13对人支气管上皮细胞SPDEF表达的影响及SPDEF在哮喘气道黏液高分泌中的作用

目的探讨白细胞介素(IL)-13对人支气管上皮细胞SPDEF表达的影响及SPDEF在哮喘气道黏液高分泌中的作用。方法将人原代支气管上皮细胞(NHBE细胞)分为对照组、IL-13组及IL-13+SPDEF siRNA组。培养28天后,收集NHBE细胞并提取总RNA,采用实时荧光定量聚合酶链反应检测NHBE细胞SPDEF、粘蛋白MUC5AC及MUC5B mRNA的表达水平,流式细胞术检测MUC5AC阳性细胞数量和免疫荧光强度,免疫荧光染色检测粘蛋白MUC5AC和MUC5B的表达水平。结果IL-13组NHBE细胞SPDEF和MUC5AC mRNA的表达水平、MUC5AC阳性细胞数量和免疫荧光强度均明显高于对照组(P<0.001),而MUC5B mRNA的表达水平明显低于对照组(P<0.05);IL-13+SPDEF siRNA组NHBE细胞SPDEF和MUC5AC mRNA的表达水平、MUC5AC阳性细胞数量和免疫荧光强度均明显低于IL-13组(P<0.001);IL-13+SPDEF siRNA组MUC5B mRNA的表达水平明显低于对照组(P<0.05)。IL-13组NHBE细胞MUC5AC的表达水平明显高于对照组和IL-13+SPDEF siRNA组,而MUC5B的表达水平低于对照组。结论IL-13可能通过诱导人支气管上皮细胞SPDEF上调,促进气道粘蛋白MUC5AC的高表达,引起哮喘气道黏液高分泌。     

蛋白激酶C参与调节肿瘤坏死因子α刺激大鼠气管上皮细胞MUC5AC蛋白的表达

气道黏液高分泌是呼吸道多种疾病如慢性支气管炎、支气管哮喘(简称哮喘)和囊性肺纤维化等发病机制的一个重要特征.目前黏液分泌的机制尚不清楚,近年研究发现MUC5AC蛋白在气道分泌物中尤为重要[1].我们的实验旨在研究肿瘤坏死因子α(TNF-α)在MUC5AC黏蛋白高分泌中的作用及其刺激黏蛋白高表达的细胞内机制.     

二陈汤对慢性支气管炎气道黏液高分泌的影响

目的观察二陈汤对慢性支气管炎大鼠气道黏液高分泌的影响及其机制。方法采用香烟烟熏加内毒素脂多糖制备慢性支气管炎大鼠模型,大鼠随机分为正常组,模型组,二陈汤低、中、高剂量组,急支糖浆组。正常组和模型组灌胃生理盐水6 ml/d,急支糖浆组灌胃给予太极急支糖浆12 g/kg,二陈汤低、中、高剂量组分别灌胃2.45、4.90、9.80 g/kg,连续14 d。免疫组化检测黏蛋白(MUC)5AC和水通道蛋白(AQP)5在支气管组织中的表达。结果与正常组相比,模型组MUC5AC蛋白表达显著增强,AQP5蛋白表达显著减弱(均P0.01),MUC5AC与AQP5蛋白表达呈负相关(r=-0.55,P0.01);与模型组相比,二陈汤中剂量组MUC5AC蛋白表达显著减弱,AQP5蛋白表达增强(均P0.01),MUC5AC与AQP5蛋白表达呈负相关(r=-0.75,P0.01)。结论二陈汤对慢性支气管炎气道黏液高分泌有调节作用,其机制可能与抑制MUC5AC、上调AQP5蛋白表达有关。     

罗格列酮对哮喘小鼠肺组织γ氨基丁酸A受体α亚单位及MUC5AC表达的影响研究

目的探究罗格列酮对哮喘小鼠肺组织γ氨基丁酸A受体α亚单位(GABAARα)及MUC5AC表达的影响。方法 2017年12月—2018年1月,将50只健康雌性BABL/C小鼠随机分为对照组、哮喘组、地塞米松组、罗格列酮组及联合治疗组,每组10只。动物模型制备分为致敏、激发、取材3部分,哮喘组、地塞米松组、罗格列酮组及联合治疗组小鼠均进行致敏、激发,其中地塞米松组小鼠于激发前30 min给予地塞米松雾化吸入,罗格列酮组小鼠给予罗格列酮雾化吸入,联合治疗组小鼠给予地塞米松联合罗格列酮雾化吸入;对照组小鼠在致敏、激发阶段均给予0.9%氯化钠溶液。最后1次激发后24 h取小鼠肺组织进行检测。采用苏木素-伊红染色(HE染色)观察肺组织病理学表现,采用蛋白质印迹法检测肺组织GABAARα及MUC5AC蛋白浓度,采用聚合酶链反应检测肺组织GABAARα及MUC5AC mRNA相对表达量。结果 (1)HE染色结果显示,哮喘组小鼠气道黏膜上皮局部脱落,黏膜下充血水肿,支气管壁及血管壁周围有较多炎性细胞浸润;地塞米松组、罗格列酮组及联合治疗组小鼠上述表现较哮喘组减轻。(2)哮喘组、地塞米松组、罗格列酮组及联合治疗组小鼠肺组织GABAARα、MUC5AC蛋白浓度及其mRNA相对表达量高于对照组,地塞米松组、罗格列酮组及联合治疗组小鼠肺组织GABAARα、MUC5AC蛋白浓度及其mRNA相对表达量低于哮喘组(P<0.05);而地塞米松组、罗格列酮组及联合治疗组小鼠肺组织GABAARα、MUC5AC蛋白浓度及其mRNA相对表达量比较,差异无统计学意义(P>0.05)。结论罗格列酮对哮喘小鼠肺组织GABAARα、MUC5AC表达的影响与地塞米松及地塞米松联合罗格列酮相当,其可能通过下调GABAARα、MUC5AC表达而减少哮喘小鼠气道黏液过度分泌。     

哮喘黏液高分泌研究进展

哮喘是一种以慢性气道炎症和黏液高分泌为特点的疾病，但黏液的过度分泌在哮喘病理生理中的作用被相对低估了。实际上黏液栓塞对气流受限及气道高反应有相当的影响，严重关系到哮喘的发病率和死亡率。哮喘患者分泌的黏液中主要表现为MUC5AC、MUC5B和MUC2的过度表达，哮喘相关的炎性介质也参与了哮喘黏液高分泌的调控。EGFR级联反应是许多不同刺激导致黏液分泌的共同路径，这些刺激主要包括氧化应激、蛋白酶和细胞因子等。在这些领域的研究有助于我们发现新的抗黏液高分泌药物，并借此加强对哮喘的治疗，提高哮喘患者生活质量。本文从哮喘黏液高分泌特点、调控机制和药物治疗等方面对哮喘黏液高分泌进行综述。     

胰腺导管内乳头状黏液性肿瘤组织中MUC1,MUC2,MUC5AC和TFF1的表达意义

目的:了解胰腺导管内乳头状黏液性肿瘤(IPMN)中MUC1,MUC2,MUC5AC及TFF1的表达意义.方法:采用免疫组织化学方法,检测IPMN手术切除标本9例中MUC1,MUC2,MUC5AC及TFF1的表达,分析不同组织学类型及不同性质IPMN之间黏液蛋白及TFF1表达的差异.结果:MUC1表达率为44.4%,MUC2为66.7%,MUC5AC和TFF1为100%.胃型IPMN黏液蛋白表达模式主要为MUC1-,MUC2-,MUC5AC .肠型IPMN为MUC1-,MUC2 ,MUC5AC .嗜酸性细胞型IPMN为MUC1 ,MUC2 ,MUC5AC .IPMN相关管状癌MUC1阳性,胶质癌MUC2阳性.MUC5AC和TFF1共同表达,在浸润癌中表达下降.胃型IPMN常与其他类型IPMN同时出现并且不同上皮之间出现移行过渡,提示胃型可能是其他类型IPMN的前期病变.结论:不同组织学亚型的IPMN具有不同的黏液蛋白表达模式.MUC1表达提示侵袭性生物.     

慢性阻塞性肺疾病患者MUC5AC表达及其与核因子-κB的关系

目前普遍认为，慢性阻塞性肺疾病（COPD）以气道、肺实质及肺血管的慢性炎症为特征。早期临床表现为黏液高分泌。有研究发现，黏液过度分泌与第1秒钟用力呼气容积（FEV1）的下降相关。现已知，黏蛋白MUCSAC和MUC5B是人类气道黏液的主要成分。核因子-κB（NF-κB）是多种重要前炎因子的转录酶活因子，在炎症的发生过程中起关键作用。本研究检测经中度COPD患者和肺功能正常人群气道上皮黏蛋白MUC5AC基因表达，探索其与NF-κB的关系。     

补脾益气方对脾虚哮喘大鼠肺组织黏蛋白5AC表达的影响

目的 观察补脾益气方治疗前、后的脾虚哮喘大鼠黏蛋白(mucin,MUC)5AC表达的变化.旨在探讨补脾益气方对脾虚哮喘气道黏液高分泌的影响.方法 50只Wistar雄性大鼠,按照随机数字法分为5组:对照组、脾虚哮喘组、哮喘组、脾虚哮喘治疗组和哮喘治疗组.每组10只.采用ELISA测定支气管肺泡灌洗液(BALF)中MUC5AC含量,采用RT-PCR测定肺组织MUC5AC的mRNA表达水平.结果 脾虚哮喘组和哮喘组大鼠BALF中MUC5AC含量和肺组织MUC5AC表达均显著升高,和对照组比较差异显著(P<0.01).并且和哮喘组相比较,脾虚哮喘组BALF中MUC5AC含量和肺组织MUC5AC表达显著升高(P<0.01).和脾虚哮喘组比较,脾虚哮喘治疗组BALF中MUC5AC含量和肺组织MUC5AC表达显著降低(P<0.01).和哮喘组比较,哮喘治疗组BALF中MUC5AC含量显著降低(P<0.01).结论 脾虚哮喘大鼠肺组织MUC5AC表达进一步升高,BALF中的MUC5AC含量进一步增加,补脾益气方能够使其不同程度逆转.     

Azithromycin, clarithromycin and telithromycin inhibit MUC5AC induction by Chlamydophila pneumoniae in airway epithelial cells

BackgroundAirway mucus hypersecretion is an important problem in chronic respiratory diseases including bronchial asthma. Chlamydophila pneumoniae is recently confirmed to be a pathogen in bronchial asthma, but the relationship between C. pneumoniae and mucus hypersecretion is uncertain. In this study, we examined whether C. pneumoniae induces MUC5AC mucin in airway epithelial cells. We also examined the effects of macrolide and ketolide antibiotics on the C. pneumoniae-induced mucus production.MethodsMUC5AC production in bronchial epithelial cells after stimulation with C. pneumoniae was analyzed by ELISA and quantitative RT-PCR. NF-κB and phosphorylated ERK were also analyzed. For inhibition study, cells were pretreated with azithromycin, clarithromycin and telithromycin before stimulation.ResultsC. pneumoniae dose-dependently induced MUC5AC production and gene expression. The ERK-NF-κB pathway was involved in C. pneumoniae-induced MUC5AC production. Macrolides and ketolides dose-dependently reduced C. pneumoniae-induced MUC5AC production. However, azithromycin was apparently less effective than the other antibiotics. Clarithromycin and telithromycin, but not azithromycin, reduced NF-κB activation.ConclusionsClarithromycin and telithromycin were thought to interfere with the signal pathways between ERK and NF-κB. These results suggest that airway mucus hypersecretion is one of the mechanisms of C. pneumoniae-induced bronchial asthma, and that macrolide and ketolide antibiotics represent a novel therapeutic intervention in these patients.     

Mucus and MUC in asthma

PURPOSE OF REVIEW: Asthma is characterized by chronic airway inflammation and a mucus hypersecretory phenotype comprising excess mucus secretion, goblet cell hyperplasia and submucosal gland hypertrophy. This augmented mucus secretion has been relatively undervalued in asthma compared with airway inflammation. However, mucus plugging contributes to airflow limitation and airway hyperresponsiveness, and to morbidity and mortality in asthma. We review recent contributions to this field and therapeutic avenues to control mucus hypersecretion. RECENT FINDINGS: A distinct mucus hypersecretory phenotype may present in asthma. Overexpression of MUC5AC, MUC5B and MUC2 have been described in asthma secretions, but identification of defined biochemical abnormalities and polymorphisms of mucin genes linked to asthma remains elusive. Activation of epidermal growth factor receptor (EGFR) activation appears central in transducing many different stimuli, including oxidative stress, proteases and cytokines. In contrast, nitrosative stress has barely been investigated. The existence of crosstalk between EGFR and other receptor systems may provide new clues regarding the activity of acetylcholine, adenosine and other agonists of G-protein-coupled receptors and other receptor families on mucin secretion. Modern techniques for noninvasive detection of mucus pathology will advance clinical research in this field. SUMMARY: Airway mucus hypersecretion as a part of airway remodelling represents a problem in asthma, and studies of pathophysiology and therapeutic approaches are therefore warranted. Identification of targets such as the EGFR cascade, which are crucial in excessive and abnormal mucus secretion, may lead to the rational design of new antihypersecretory drugs that may enhance future asthma treatment.     

Melatonin inhibits MUC5AC production via suppression of MAPK signaling in human airway epithelial cells

Mucus acts as a primary defense system in the airway against various stimuli. However, excess mucus production causes a reduction in lung function via limitation of the airflow in the airway of patients suffering from asthma or chronic obstructive pulmonary disease (COPD). In this study, we evaluated the effects of melatonin on the production of MUC5AC, a major constituent of the mucin that is secreted from the airway, using epidermal growth factor (EGF)‐stimulated NCI‐H292 cells, a human mucoepidermoid carcinoma cell line, and an ovalbumin (OVA)‐induced asthma murine model. Melatonin treatment significantly reduced the mRNA and protein levels of MUC5AC and reduced interleukin (IL)‐6 production in EGF‐stimulated H292 cells. Melatonin markedly decreased the phosphorylation of MAPKs, including ERK1/2, JNK, and p‐38, induced by EGF stimulation. These findings were consistent with the results using MAPK inhibitors. Particularly, co‐treatment with melatonin and a MAPK inhibitor more effectively suppressed MAPK phosphorylation than treatment with a MAPK inhibitor alone, which resulted in a reduction in MUC5AC expression. In the asthma murine model, melatonin‐treated mice exhibited a marked reduction in MUC5AC expression in the airway compared with the OVA‐induced mice. These reductions were accompanied by reductions in proinflammatory cytokine production and inflammatory cell infiltration. Collectively, these findings indicate that melatonin effectively inhibits MUC5AC expression. These effects may be closely associated with the inhibition of MAPK phosphorylation. Furthermore, our study suggests that melatonin could represent a potential therapeutic for chronic airway diseases, such as asthma and COPD.     

In vivo and in vitro effects of macrolide antibiotics on mucus secretion in airway epithelial cells

To examine the in vivo effects of macrolide antibiotics on mucus hypersecretion, we induced hypertrophic and metaplastic changes of goblet cells in rat nasal epithelium by intranasal instillation of ovalbumin (OVA) in OVA-sensitized rats and by intranasal LPS instillation. Oral administration of clarithromycin (CAM) (5-10 mg/kg) significantly inhibited OVA- and LPS-induced mucus production and neutrophil infiltration, whereas josamycin and ampicillin showed no effect. In vitro effects of macrolide antibiotics on airway epithelial cells were examined using NCI-H292 cells and human nasal epithelial cells cultured in air-liquid interface. Mucus secretion was evaluated by ELISA using anti-mucin monoclonal antibodies (anti-MUC5AC and HCS18). CAM and erythromycin significantly inhibited spontaneous and tumor necrosis factor-alpha (20 ng/ml)-induced mucus secretion from NCI-H292 cells at 10-6 to 10-7 M and from human nasal epithelial cells at 10-4 to 10-5 M. MUC5AC messenger RNA expression was also significantly inhibited. These results indicate that the 14-member macrolide antibiotics, CAM and erythromycin, exert direct inhibitory effects on mucus secretion from airway epithelial cells and that they may be useful for the treatment of mucus hypersecretion caused by allergic inflammation and LPS stimulation.     

Erythromycin attenuates MUC5AC synthesis and secretion in cultured human tracheal cells infected with RV14

Background and objective:   The common cold is a major cause of asthma exacerbation and chronic obstructive lung disease. Rhinovirus is reported to be responsible for more than 50% of cases of the common cold. In a previous study, we reported that rhinovirus infection of cultured airway cells induced MUC5AC mucin overproduction and hypersecretion by activating the p44/42 mitogen-activated protein kinase (p44/42 MAPK) pathway. The aim of this study was to examine the effect of erythromycin on RV14-induced airway mucin overproduction and hypersecretion.
Methods:   RV14-infected human tracheal epithelial cells were treated with erythromycin.
Results:   Erythromycin blocked RV14-induced MUC5AC protein overproduction and hypersecretion, and also blocked RV14-induced p44/42 MAPK activation in the cells.
Conclusions:   Erythromycin may attenuate RV14-induced MUC5AC overproduction and hypersecretion by blocking the p44/42 MAPK pathway or its upstream regulators.