Calcium-activated chloride channels（CaCCs） are the crucial regulators of transepithelial fluid secretion, smooth muscle contraction and sensory transduction. Recently, compelling evidence has indicated that TMEM16A...Calcium-activated chloride channels（CaCCs） are the crucial regulators of transepithelial fluid secretion, smooth muscle contraction and sensory transduction. Recently, compelling evidence has indicated that TMEM16A（ANO1 or anoctamin-1） is a bona fide calcium-acvtivated chloride channel. A few small molecule CaCCs regulators are available for functional and therapeutic studies. We screened 126 natural compounds from Chinese herbs. Screening was performed with an iodide influx assay in Fischer rat thyroid epithelial cells to coexpress ANO1 and an iodide-sensitive fluorescent indicator（EYFP-H148Q/I152L）. Imperatorin, a coumarin compound, was identified to inhibit ANO1-mediated chloride transport activated by multiple calcium-elevating agonists. The inhibitory effect is dose-dependent with IC50～14.63 μmol/L. Interestingly, imperatorin activated CFTR chloride channel with EC50～35.52 μmol/L. The adverse effects of imperatorin on CaCC and CFTR chloride channels will make it useful in pharmacological dissection of chloride transport in airway and intestinal epithelium. Further studies are required to evaluate the therapeutic effects of imperatorin on hypertension, asthma and certain tumors.展开更多
Background Chronic obstructive pulmonary disease （COPD） is usually complicated with mucus overproduction in airway. Recently the increased expression of the human calcium-activated chloride channel 1 （CaCC1） was f...Background Chronic obstructive pulmonary disease （COPD） is usually complicated with mucus overproduction in airway. Recently the increased expression of the human calcium-activated chloride channel 1 （CaCC1） was found to play an important role in mucus overproduction in the asthmatic airways. To investigate the relationship of CaCC1 and mucus overproduction in the airway of Chinese patients with COPD, the expressions of CaCC1, MUC5AC and mucus in bronchial tissues were examined. Methods Bronchial tissues were obtained from fiberoptic bronchoscopy and bronchial biopsy in West China Hospital from April to July in 2004. Twenty-five patients were diagnosed as the patients with COPD overproduction, and other 20 were the control subjects. The expressions of CaCC1, MUC5AC and mucin in bronchial tissues were detected by reverse transcriptase-polymerase chain reaction （RT-PCR）, in situ hybridization with digoxigenin （DIG）-Iabeled RNA probe, immunohistochemical and alcian blue-periodic acid Schiff （AB-PAS） staining, respectively. Results Compared with the control group, the stronger expressions of CaCC1 were further detected throughout the bronchial tissues from patients with COPD （P〈0.01）. Furthermore, the stronger expressions of the CaCC1 mRNA were related to the severity of airflow obstruction. Samples from COPD showed a stronger staining for MUC5AC than those in control subjects （P〈0.01） and AB-PAS staining revealed more mucins in COPD patients＇ submucosal gland comparing with that in control subjects （P〈0.01）. Expression levels of the CaCC1 mRNA were respectively negatively correlated with the patients＇ forced expiratory volume in one second （FEV~） / forced vital capacity （FVC） data, FEV1% predicted data, V50% predicted data, V25% predicted data （r=-0.43, r=-0.43, r=-0.35, r=-0.36, P〈0.01, P〈0.01, P〈0.05, P〈0.05）. While the expression levels of the CaCC1 mRNA were well correlated with the expression levels of the MUC5AC mRNA of airway epithelium and the PAS-AB stained area of submucosal glands （r=0.39, r=0.46, P〈0.05, P〈0.01）. Expression levels of the MUC5AC mRNA were negatively correlated with the patients＇ FEV1/FVC data （P=0.01）, FEV1% pred data （P=-0.01）, V50% predicted data, V25% predicted data（r=-0.53, r=-0.53, r=-0.48, r=-0.43, P〈0.01, P〈0.01, P〈0.01, P〈0.01）. While the expression levels of the MUC5AC mRNA were well correlated with the positively PAS-AB stained area of submucosal gland （P〈0.05）, and the correlation coefficients were 0.43. Conclusion These results suggest that the stronger gene expression of CaCC1 exists, complicated with mucus overproduction in the airwav of Chinese patients with COPD.展开更多
Background Expression of murine calcium-activated chloride channel family member 3 （mCLCA3） has been reported to be increased in the airway epithelium of asthmatic mice challenged with ovalbumin （OVA）. However, it...Background Expression of murine calcium-activated chloride channel family member 3 （mCLCA3） has been reported to be increased in the airway epithelium of asthmatic mice challenged with ovalbumin （OVA）. However, its role in asthmatic airway inflammation under no OVA exposure has not yet been clarified. Methods mCLCA3 plasmids were transfected into the airways of normal BALB/c mice. mCLCA3 expression and airway inflammation in mouse lung tissue were evaluated. Cell differentials and cytokines in bronchoalveolar lavage fluid （BALF） were analyzed. The expression of mCLCA3 protein and mucus protein mucin-5 subtype AC （MUC5AC） were analyzed by Western blotting. The mRNA levels of mCLCA3, MUC5AC and interleukin-13 （IL-13） were determined quantitatively. Results mCLCA3 expression was not detected in the control group while strong immunoreactivity was detected in the OVA and mCLCA3 plasmid groups, and was strictly localized to the airway epithelium. The numbers of inflammatory cells in lung tissue and BALF were increased in both mCLCA3 plasmid and OVA groups. The protein and mRNA levels of mCLCA3 and MUC5AC in the lung tissue were significantly increased in the mCLCA3 plasmid and OVA groups compared to the control group. The level of IL-13, but not IL-4, IL-5, IFN-y, CCL2, CCL5 or CCL11, was significantly increased compared with control group in BALF in the mCLCA3 plasmid and OVA groups. The level of IL-13 in the BALF in the mCLCA3 plasmid group was much higher than that in the OVA group （P 〈0.05）. The level of mCLCA3 mRNA in lung tissue was positively correlated with the levels of MUC5AC mRNA in lung tissue, IL-13 mRNA in lung tissue, the number of eosinophils in BALF, and the content of IL-13 protein in BALE The level of IL-13 mRNA in lung tissue was positively correlated with the number of eosinophils in BALF and the level of MUC5AC mRNA in lung tissue. Conclusion These findings suggest that increased expression of a single-gene, mCLCA3, could simulate an asthma attack, and its mechanism may involve mCLCA3 overexpression up-regulating IL-13 expression.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.30670477, 30973577 and 30770493)the National Basic Research Program of China(No.2009CB521908)
文摘Calcium-activated chloride channels（CaCCs） are the crucial regulators of transepithelial fluid secretion, smooth muscle contraction and sensory transduction. Recently, compelling evidence has indicated that TMEM16A（ANO1 or anoctamin-1） is a bona fide calcium-acvtivated chloride channel. A few small molecule CaCCs regulators are available for functional and therapeutic studies. We screened 126 natural compounds from Chinese herbs. Screening was performed with an iodide influx assay in Fischer rat thyroid epithelial cells to coexpress ANO1 and an iodide-sensitive fluorescent indicator（EYFP-H148Q/I152L）. Imperatorin, a coumarin compound, was identified to inhibit ANO1-mediated chloride transport activated by multiple calcium-elevating agonists. The inhibitory effect is dose-dependent with IC50～14.63 μmol/L. Interestingly, imperatorin activated CFTR chloride channel with EC50～35.52 μmol/L. The adverse effects of imperatorin on CaCC and CFTR chloride channels will make it useful in pharmacological dissection of chloride transport in airway and intestinal epithelium. Further studies are required to evaluate the therapeutic effects of imperatorin on hypertension, asthma and certain tumors.
基金the grants from Natural Science Foundation of China and from China Medical Board of New York to Dr. F.Q. Wen(No.30425007,30370627,00-722,06-838)
文摘Background Chronic obstructive pulmonary disease （COPD） is usually complicated with mucus overproduction in airway. Recently the increased expression of the human calcium-activated chloride channel 1 （CaCC1） was found to play an important role in mucus overproduction in the asthmatic airways. To investigate the relationship of CaCC1 and mucus overproduction in the airway of Chinese patients with COPD, the expressions of CaCC1, MUC5AC and mucus in bronchial tissues were examined. Methods Bronchial tissues were obtained from fiberoptic bronchoscopy and bronchial biopsy in West China Hospital from April to July in 2004. Twenty-five patients were diagnosed as the patients with COPD overproduction, and other 20 were the control subjects. The expressions of CaCC1, MUC5AC and mucin in bronchial tissues were detected by reverse transcriptase-polymerase chain reaction （RT-PCR）, in situ hybridization with digoxigenin （DIG）-Iabeled RNA probe, immunohistochemical and alcian blue-periodic acid Schiff （AB-PAS） staining, respectively. Results Compared with the control group, the stronger expressions of CaCC1 were further detected throughout the bronchial tissues from patients with COPD （P〈0.01）. Furthermore, the stronger expressions of the CaCC1 mRNA were related to the severity of airflow obstruction. Samples from COPD showed a stronger staining for MUC5AC than those in control subjects （P〈0.01） and AB-PAS staining revealed more mucins in COPD patients＇ submucosal gland comparing with that in control subjects （P〈0.01）. Expression levels of the CaCC1 mRNA were respectively negatively correlated with the patients＇ forced expiratory volume in one second （FEV~） / forced vital capacity （FVC） data, FEV1% predicted data, V50% predicted data, V25% predicted data （r=-0.43, r=-0.43, r=-0.35, r=-0.36, P〈0.01, P〈0.01, P〈0.05, P〈0.05）. While the expression levels of the CaCC1 mRNA were well correlated with the expression levels of the MUC5AC mRNA of airway epithelium and the PAS-AB stained area of submucosal glands （r=0.39, r=0.46, P〈0.05, P〈0.01）. Expression levels of the MUC5AC mRNA were negatively correlated with the patients＇ FEV1/FVC data （P=0.01）, FEV1% pred data （P=-0.01）, V50% predicted data, V25% predicted data（r=-0.53, r=-0.53, r=-0.48, r=-0.43, P〈0.01, P〈0.01, P〈0.01, P〈0.01）. While the expression levels of the MUC5AC mRNA were well correlated with the positively PAS-AB stained area of submucosal gland （P〈0.05）, and the correlation coefficients were 0.43. Conclusion These results suggest that the stronger gene expression of CaCC1 exists, complicated with mucus overproduction in the airwav of Chinese patients with COPD.
基金This work was supported by a grant from the National Natural Science Foundation of China （No. 30500224）.
文摘Background Expression of murine calcium-activated chloride channel family member 3 （mCLCA3） has been reported to be increased in the airway epithelium of asthmatic mice challenged with ovalbumin （OVA）. However, its role in asthmatic airway inflammation under no OVA exposure has not yet been clarified. Methods mCLCA3 plasmids were transfected into the airways of normal BALB/c mice. mCLCA3 expression and airway inflammation in mouse lung tissue were evaluated. Cell differentials and cytokines in bronchoalveolar lavage fluid （BALF） were analyzed. The expression of mCLCA3 protein and mucus protein mucin-5 subtype AC （MUC5AC） were analyzed by Western blotting. The mRNA levels of mCLCA3, MUC5AC and interleukin-13 （IL-13） were determined quantitatively. Results mCLCA3 expression was not detected in the control group while strong immunoreactivity was detected in the OVA and mCLCA3 plasmid groups, and was strictly localized to the airway epithelium. The numbers of inflammatory cells in lung tissue and BALF were increased in both mCLCA3 plasmid and OVA groups. The protein and mRNA levels of mCLCA3 and MUC5AC in the lung tissue were significantly increased in the mCLCA3 plasmid and OVA groups compared to the control group. The level of IL-13, but not IL-4, IL-5, IFN-y, CCL2, CCL5 or CCL11, was significantly increased compared with control group in BALF in the mCLCA3 plasmid and OVA groups. The level of IL-13 in the BALF in the mCLCA3 plasmid group was much higher than that in the OVA group （P 〈0.05）. The level of mCLCA3 mRNA in lung tissue was positively correlated with the levels of MUC5AC mRNA in lung tissue, IL-13 mRNA in lung tissue, the number of eosinophils in BALF, and the content of IL-13 protein in BALE The level of IL-13 mRNA in lung tissue was positively correlated with the number of eosinophils in BALF and the level of MUC5AC mRNA in lung tissue. Conclusion These findings suggest that increased expression of a single-gene, mCLCA3, could simulate an asthma attack, and its mechanism may involve mCLCA3 overexpression up-regulating IL-13 expression.
