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。     

Elimination of IL-13 reverses established goblet cell metaplasia into ciliated epithelia in airway epithelial cell culture.

BACKGROUND: Interleukin (IL)-13 induces goblet cell metaplasia and plays an important role in mucus hypersecretion in asthma. We previously reported that IL-13 induced goblet cell differentiation along with less ciliated cell differentiation in guinea pig tracheal epithelial cells in vitro. In this study, we asked whether elimination of IL-13 could reverse the established goblet cell metaplasia into ciliated epithelia. METHODS: Primary epithelial cells from guinea pig tracheas were cultured at an air-liquid interface with the medium containing human recombinant IL-13 for 14 days, and continuously cultured with IL-13-eliminated medium, or cultured under the condition of neutralization of IL-13 with anti IL-13 antibody. RESULTS: 2 days after elimination of IL-13, the periodic acid-Schiff-positive area as well as MUC5AC protein level rapidly decreased. After 4 days, the number of goblet cells dramatically decreased, while that of ciliated cells inversely increased. The total number of epithelial cells did not change, and 5-bromo-2'-deoxyuridine uptake decreased after IL-13 elimination. Transitional cells with cilia and secretory granules increased after IL-13 elimination. Similarly, the neutralization of IL-13 with anti-IL-13 antibody for 5 days reversed the goblet cell metaplasia into ciliated epithelia, and transitional cells also increased. CONCLUSIONS: Elimination of IL-13 reverses goblet cell metaplasia into ciliated epithelia in vitro, and transition of goblet cells to other phenotypes, especially ciliated cells, may be involved in this phenomenon. IL-13 inhibition may be a therapeutic strategy of established goblet cell metaplasia in asthma.     

Sphingosine kinase 1 regulates mucin production via ERK phosphorylation

Our previous report showed that inhibition of sphingosine kinase (SphK) ameliorates eosinophilic inflammation and mucin production in a mouse asthmatic model. To clarify the role of SphK in airway mucin production, we utilized the mouse asthmatic model and found that both SphK and MUC5AC expression were increased and co-localized in airway epithelium. Next we cultured normal human bronchial epithelial cells in an air–liquid interface and treated with IL-13 to induce their differentiation into goblet cells. We found that SphK1 and MUC5AC expression was increased by IL-13 treatment at both protein and mRNA levels, whereas SphK2 expression was not changed. N,N-dimethylsphingosine (DMS), a potent SphK inhibitor, decreased MUC5AC expression up-regulated by IL-13 treatment. Furthermore, DMS inhibited IL-13-induced ERK1/2 phosphorylation but neither p38 MAPK nor STAT6 phosphorylation. These results suggest that SphK1 is involved in MUC5AC production induced by IL-13 upstream of ERK1/2 phosphorylation, and independent of STAT6 phosphorylation.     

Expression of HCLCA1 in cystic fibrosis lungs is associated with mucus overproduction.

Mucus overproduction is typical in cystic fibrosis (CF) airway disease. The human calcium-activated chloride channel, hCLCA1, has been reported to be upregulated by interleukin (IL)-9 and to regulate the expression of mucins. Therefore, the expression of IL-9, IL-9 receptor (IL-9R) and hCLCA1 between the lungs of CF patients and healthy control subjects was compared. Endoscopic biopsy samples of bronchial mucosa from 10 CF patients and six control subjects were stained with periodic acid-Schiff. IL-9, IL-9R and hCLCA1 expression was determined by immunocytochemistry. Expression of hCLCA1 mRNA was also determined by in situ hybridisation. The present study found significant increases in IL-9, IL-9R and hCLCA1 immunoreactivity, hCLCA1 mRNA expression, and numbers of mucus-producing cells in the mucosa of CF patients compared to control subjects. Positive correlations were found between IL-9R-positive-cells with IL-9-positive cells and hCLCA1-positive cells, and between PAS-positive cells with hCLCA1-positive cells and IL-9R-positive cells. Expression of hCLCA1 mRNA was colocalised with IL-9R expression and PAS-positive staining in epithelial cells. Increased expression of interleukin-9 and interleukin-9 receptor, as well as an upregulation of the human calcium-activated chloride channel, hCLCA1, in mucus-producing epithelium of cystic fibrosis patients, support the hypothesis that interleukin-9 contributes to mucus overproduction in cystic fibrosis airway disease.     

LPS-induced mucin expression in human sinus mucosa can be attenuated by hCLCA inhibitors

BACKGROUND: hCLCA1 is a member of the calcium-activated chloride channel family and is associated with disease-inducible mucus expression. Niflumic acid (NFA) and a closely related chemical structure are reported inhibitors of calcium-activated chloride channels and endotoxin-inducible mucus expression in the mouse. Therefore, we tested the hypothesis that hCLCA1 may be involved in lipopolysaccharide (LPS) induced mucin up-regulation in human airways. We also investigated the effect of NFA and MSI-2216 on LPS-induced mucin up-regulation. MATERIALS AND METHODS: Explanted human airways and the muco-epidermoid cell line Calu-3 were stimulated with LPS. Different concentrations of NFA or MSI-2216 were added to LPS-stimulated airway mucosa and Calu-3 cells. Expression of hCLCA1 and MUC5AC mRNA and protein was quantified in human airways using real-time PCR and PAS staining. In addition, immunohistochemistry was performed for quantification of inflammatory cells (lymphocytes, monocytes, eosinophils, and neutrophils) in the submucosa of the airways. Expression of hCLCA1 protein in Calu-3 cells was analysed by FACS. RESULTS: LPS significantly induced hCLCA1 and MUC5AC mRNA and protein expression in human airway mucosa (P < 0.05). NFA and MSI-2216 significantly decreased LPS-induced mucus expression in explanted airway mucosa in a dose-dependent manner (P < 0.05). In Calu-3 cells, LPS significantly increased hCLCA1 surface expression whereas intracellular expression was significantly decreased (P < 0.05). In Calu-3 cells, NFA and MSI-2216 also significantly reduced MUC5AC mRNA expression (P < 0.05). CONCLUSIONS: These data suggest that hCLCA1 may play a role in LPS-induced mucin expression in human airway mucosa. Calcium-activated chloride channel inhibitors significantly decreased LPS-induced mucus expression both ex vivo and in vitro . Therefore, blocking of hCLCA1 may offer a therapeutic approach to reduce bacterial-induced mucus hypersecretion.     

Expression of MUC5AC and MUC5B mucins in normal and cystic fibrosis lung

Hypersecretion of airway mucus is a characteristic feature of chronic airway diseases like cystic fibrosis (CF) and leads via impairment of the muco-ciliary clearance and bacterial superinfection to respiratory failure. The major components of the mucus matrix forming family of mucins in the airways are MUC5AC and MUC5B. To investigate the expression of these glycoproteins in CF, immunohistochemistry was carried out on trachea, bronchi and peripheral lung obtained from CF patients and compared to normal lung tissues. MUC5AC immunohistochemistry demonstrated signals in goblet cells of the epithelial lining. Also, goblet cells inside glandular secretory ducts revealed MUC5AC-positive staining. In comparison to those from normal subjects, CF sections were characterized by inflammatory changes and goblet cell hyperplasia, resulting in increased numbers of MUC5AC-positive cells. Immunohistochemical staining for MUC5B showed abundant staining of submucosal glands and epithelial goblet cells. Inside the glands, the immunoreactivity was restricted to glandular mucous cells. MUC5AC and MUC5B are expressed in the same histological pattern in CF compared to normal tissues with an increase of MUC5AC-positive cells due to goblet cell hyper- and metaplasia.     

Differential regulation by glucocorticoid of interleukin-13-induced eosinophilia,hyperresponsiveness, and goblet cell hyperplasia in mouse airways

Interleukin (IL)-13 induces important features of bronchial asthma such as eosinophilic infiltration, airway hyperresponsiveness (AHR), and mucus hypersecretion. Although glucocorticoids suppress airway inflammation and remain the most effective therapy for asthma, the effects of glucocorticoids on the IL-13-dependent features are unknown. We studied the effects of dexamethasone on eotaxin production, eosinophil accumulation, goblet cell hyperplasia, and AHR after IL-13 administration into the airways of mice in vivo. MUC5AC gene expression, a marker of goblet cell hyperplasia, was also analyzed. IL-13 alone dose dependently induced AHR. Treatment with dexamethasone inhibited eotaxin expression and completely abolished eosinophil accumulation, but it did not affect AHR, MUC5AC overexpression, or goblet cell hyperplasia induced by IL-13. The effects of tumor necrosis factor-alpha on IL-13-induced AHR were also examined. Tumor necrosis factor-alpha did not affect AHR despite marked enhancement of eosinophil infiltration in IL-13-treated mice. These findings suggest that glucocorticoid is not sufficient to suppress IL-13-induced AHR or goblet cell hyperplasia and that eotaxin expression and eosinophilic inflammation do not have a causal relationship to the induction of AHR or goblet cell hyperplasia by IL-13. Control of steroid-resistant features induced by IL-13, including AHR and mucus production, may provide new therapeutic modalities for asthma.     

Cellular localization of interleukin 13 receptor alpha2 in human primary bronchial epithelial cells and fibroblasts.

BACKGROUND: Interleukin (IL) 13 is a key cytokine in asthma, regulating fibrosis, airway remodeling, induction of immunoglobulin E synthesis by B cells, bronchial hyperresponsiveness, and mucus production. IL-13 signals through the type II IL-4 receptor (IL-4R), which is composed of the IL-4Ralpha and the IL-13Ralpha1 chains. Another IL-13 binding chain, IL-13Ralpha2, binds IL-13 with high affinity but has no known signaling capability and is thought to serve as a decoy receptor providing tight regulation of IL-13 responses. METHODS: In this study, we investigated the cellular localization of IL-13Ralpha2 in human primary bronchial epithelial cells and fibroblasts using flow cytometry and confocal microscopy, as well as the in vivo expression of IL-13Ralpha2 in the human bronchial mucosa by means of immunohistochemistry. RESULTS: IL-13Ralpha2 is predominantly an intracellular rather than a membrane-bound molecule in both human primary bronchial epithelial cells and fibroblasts and displays a diffuse granular cytoplasmic distribution in both cell types. IL-13Ralpha2 protein is expressed in vivo in the human bronchial mucosa with its expression being higher in bronchial epithelial cells than bronchial fibroblasts both in vivo and in vitro. CONCLUSIONS: IL-13Ralpha2 is expressed by both human primary bronchial epithelial cells and fibroblasts as an intracellular protein with a diffuse cytoplasmic distribution. In vivo, IL-13Ralpha2 is expressed in the human airway mucosa mainly by bronchial epithelial cells.     

Pseudomonas aeruginosa induces MUC5AC production via epidermal growth factor receptor.

Hypersecretory disease associated with Pseudomonas aeruginosa (PA) infections is characterised by increased goblet cells and increased mucin production. Recently, an epidermal growth factor receptor (EGFR) signalling cascade was shown to be a common pathway through which many stimuli induce mucin MUC5AC expression in airways by differentiation to a goblet cell phenotype. This study looked at whether PA products induce EGFR expression and activation and thus result in mucin MUC5AC production. Human airway epithelial (NCI-H292) cells were stimulated with PA culture supernatant (Sup). MUC5AC protein production, MUC5AC and EGFR messenger ribonucleic acid (mRNA) expression, and phosphorylated EGFR and phosphorylated p44/42 mitogen-activated protein kinase (MAPK) were all examined using enzyme-linked immunosorbent assay, by in situ hybridisation and by immunoblotting. PA Sup induced MUC5AC mRNA and subsequent protein expression, EGFR and p44/42 MAPK phosphorylation and EGFR mRNA expression. Induction of MUC5AC mRNA and protein expression and EGFR and p44/42 MAPK phosphorylation were inhibited completely by pretreatment with a selective EGFR tyrosine kinase inhibitor. Pretreatment with a selective inhibitor of MAPK kinase prevented MUC5AC production and p44/42 MAPK phosphorylation but not EGFR phosphorylation. The authors conclude that PA products induce mucin MUC5AC production in human airway epithelial cells via the expression and activation of epidermal growth factor receptor.     

IL-13 receptor alpha2 promotes epithelial cell regeneration from radiation-induced small intestinal injury in mice

BACKGROUND & AIMS: The cytokines interleukin (IL)-4 and IL-13 have pleiotropic effects on a variety of cell types and impact both pathologic changes and tissue remodeling. The aim of this study was to clarify the roles of IL-13 receptor alpha2 (IL-13Ralpha2), which is the high-affinity decoy receptor for IL-13, in gastrointestinal tract epithelial cell turnover and repair. METHODS: We have compared the regenerative process following mucosal damage induced by whole-body 3-Gy X-ray irradiation of wild-type (WT) and IL-4 receptor alpha gene-deficient (IL-4R(-/-)) mice. Then we treated mice with IL-13Ralpha2 human immunoglobulin (Ig) chimeric protein. RESULTS: Up-regulation of mRNA levels for IL-13 in NK cells in the lamina propria was seen after irradiation of WT mice. Concomitant with vigorous epithelial cell division in the jejunum following irradiation, expression of the IL-13Ralpha2 dramatically increased in myofibroblasts and fibroblasts. In contrast, epithelial cell repair was delayed in IL-4R(-/-) mice, which did not show transient up-regulation of IL-13Ralpha2, although up-regulation of IL-13 was seen. Addition of IL-13 but not IL-4 to primary cultures of small intestine from both WT and IL-4R(-/-) mice induced epithelial cell damage. Treatment of IL-4R(-/-) mice with IL-13Ralpha2-Ig resulted in increased numbers of dividing epithelial cells and improved tissue repair after irradiation. Further, treatment with IL-13Ralpha2-Ig increased numbers of microcolonies of regenerating epithelial cells in the intestine of WT mice after severe damage induced by 12-Gy irradiation. CONCLUSIONS: The IL-13Ralpha2 is a major regulatory factor involved in the regeneration of epithelial cells in the gastrointestinal tract.     

Epidermal growth factor system regulates mucin production in airways

Goblet-cell hyperplasia is a critical pathological feature in hypersecretory diseases of airways. However, the underlying mechanisms are unknown, and no effective therapy exists. Here we show that stimulation of epidermal growth factor receptors (EGF-R) by its ligands, EGF and transforming growth factor alpha (TGFalpha), causes MUC5AC expression in airway epithelial cells both in in vitro and in vivo. We found that a MUC5AC-inducing epithelial cell line, NCI-H292, expresses EGF-R constitutively; EGF-R gene expression was stimulated further by tumor necrosis factor alpha (TNFalpha). EGF-R ligands increased the expression of MUC5AC at both gene and protein levels, and this effect was potentiated by TNFalpha. Selective EGF-R tyrosine kinase inhibitors blocked MUC5AC expression induced by EGF-R ligands. Pathogen-free rats expressed little EGF-R protein in airway epithelial cells; intratracheal instillation of TNFalpha induced EGF-R in airway epithelial cells, and subsequent instillation of EGF-R ligands increased the number of goblet cells, Alcian blue-periodic acid-Schiff staining (reflecting mucous glycoconjugates), and MUC5AC gene expression, whereas TNFalpha, EGF, or TGFalpha alone was without effect. In sensitized rats, three intratracheal instillations of ovalbumin resulted in EGF-R expression and goblet-cell production in airway epithelium. Pretreatment with EGF-R tyrosine kinase inhibitor, BIBX1522, prevented goblet-cell production both in rats stimulated by TNFalpha-EGF-R ligands and in an asthma model. These findings suggest potential roles for inhibitors of the EGF-R cascade in hypersecretory diseases of airways.     

Clarithromycin suppresses IL-13-induced goblet cell metaplasia via the TMEM16A-dependent pathway in guinea pig airway epithelial cells

Background

Transmembrane protein 16A (TMEM16A) is associated with mucus secretion and ion transport in asthma. Clarithromycin (CAM) is reported to inhibit IL-13-induced goblet cell metaplasia. However, the effect of CAM on TMEM16A function and expression remains unclear.

白介素13诱导支气管哮喘气道黏液高泌的分子机制

白介素13(interleukin-13,IL-13)是一种主要由活化的Th2细胞分泌的多效能细胞因子,可刺激B细胞的增殖和IgE的合成.气道杯状细胞增生所致的黏液是哮喘的主要症状之一,黏液高分泌是肺功能第1秒用力呼气量下降加速的独立危险因素,可能成为重症哮喘的主要死因.Th2型细胞因子IL-4、IL-5、IL-9和IL-13在肺部的表达与哮喘的病理生理有密切联系,其中,IL-13被认为是目前最重要的细胞因子,它可能引起气道炎症、黏液过度分泌、杯状细胞增生和黏蛋白(MUC)基因MUC5AC高表达等多种改变.近来发现其引起黏液高分泌的作用机制成为目前研究的热点.本文针对其作用的具体分子机制作一综述.     

白介素13诱导支气管哮喘气道黏液高泌的分子机制

白介素13(interleukin-13,IL-13)是一种主要由活化的Th2细胞分泌的多效能细胞因子,可刺激B细胞的增殖和IgE的合成.气道杯状细胞增生所致的黏液是哮喘的主要症状之一,黏液高分泌是肺功能第1秒用力呼气量下降加速的独立危险因素,可能成为重症哮喘的主要死因.Th2型细胞因子IL-4、IL-5、IL-9和IL-13在肺部的表达与哮喘的病理生理有密切联系,其中,IL-13被认为是目前最重要的细胞因子,它可能引起气道炎症、黏液过度分泌、杯状细胞增生和黏蛋白(MUC)基因MUC5AC高表达等多种改变.近来发现其引起黏液高分泌的作用机制成为目前研究的热点.本文针对其作用的具体分子机制作一综述.     

白介素13诱导支气管哮喘气道黏液高泌的分子机制

白介素13(interleukin-13,IL-13)是一种主要由活化的Th2细胞分泌的多效能细胞因子,可刺激B细胞的增殖和IgE的合成.气道杯状细胞增生所致的黏液是哮喘的主要症状之一,黏液高分泌是肺功能第1秒用力呼气量下降加速的独立危险因素,可能成为重症哮喘的主要死因.Th2型细胞因子IL-4、IL-5、IL-9和IL-13在肺部的表达与哮喘的病理生理有密切联系,其中,IL-13被认为是目前最重要的细胞因子,它可能引起气道炎症、黏液过度分泌、杯状细胞增生和黏蛋白(MUC)基因MUC5AC高表达等多种改变.近来发现其引起黏液高分泌的作用机制成为目前研究的热点.本文针对其作用的具体分子机制作一综述.     

白介素13诱导支气管哮喘气道黏液高泌的分子机制

白介素13(interleukin-13,IL-13)是一种主要由活化的Th2细胞分泌的多效能细胞因子,可刺激B细胞的增殖和IgE的合成.气道杯状细胞增生所致的黏液是哮喘的主要症状之一,黏液高分泌是肺功能第1秒用力呼气量下降加速的独立危险因素,可能成为重症哮喘的主要死因.Th2型细胞因子IL-4、IL-5、IL-9和IL-13在肺部的表达与哮喘的病理生理有密切联系,其中,IL-13被认为是目前最重要的细胞因子,它可能引起气道炎症、黏液过度分泌、杯状细胞增生和黏蛋白(MUC)基因MUC5AC高表达等多种改变.近来发现其引起黏液高分泌的作用机制成为目前研究的热点.本文针对其作用的具体分子机制作一综述.     

白介素13诱导支气管哮喘气道黏液高泌的分子机制

白介素13(interleukin-13,IL-13)是一种主要由活化的Th2细胞分泌的多效能细胞因子,可刺激B细胞的增殖和IgE的合成.气道杯状细胞增生所致的黏液是哮喘的主要症状之一,黏液高分泌是肺功能第1秒用力呼气量下降加速的独立危险因素,可能成为重症哮喘的主要死因.Th2型细胞因子IL-4、IL-5、IL-9和IL-13在肺部的表达与哮喘的病理生理有密切联系,其中,IL-13被认为是目前最重要的细胞因子,它可能引起气道炎症、黏液过度分泌、杯状细胞增生和黏蛋白(MUC)基因MUC5AC高表达等多种改变.近来发现其引起黏液高分泌的作用机制成为目前研究的热点.本文针对其作用的具体分子机制作一综述.