The role of the XBP-1/AGR2 signaling pathway in the regulation of airway Mucin5ac hypersecretion under hypoxia.

Oversecretion of Mucin5ac (MUC5AC), which is primarily synthesized by goblet cells and is the major gel-forming mucin, is a hallmark of various pulmonary inflammatory diseases. Hypoxia is considered a common pathophysiologic feature in various pulmonary inflammatory diseases. It has been suggested that hypoxia-inducible factor 1α (HIF-1α) acts as a key factor in hypoxia-induced MUC5AC hypersecretion; however, the exact mechanisms that maintain the stability of HIF-1α and support oversecretion by airway epithelial cells under hypoxia are still unclear. With immunohistochemistry, we found overexpression of anterior gradient 2 (AGR2) in the bronchial epithelial cells of hypoxia-treated mice. With specific shRNA transduction, AGR2 was demonstrated to be a key factor in MUC5AC hypersecretion in vitro. Additionally, co-immunoprecipitation, cell immunochemistry and confocal microscopy experiments were performed to explore the interaction between HIF-1α and AGR2 during hypoxia-induced MUC5AC hypersecretion in vitro. The results indicated increased binding and intracytoplasmic colocation of HIF-1α and AGR2. Our findings suggest that AGR2 acts as a key regulator in hypoxia-induced airway MUC5AC hypersecretion by increasing the stability of HIF-1α. Additionally, the elevated expression of AGR2 induced by hypoxia in bronchial epithelial cells likely depends on an XBP-1-associated pathway.

Bombesin receptor-activated protein regulates neutrophil elastase-induced mucin5AC hypersecretion in human bronchial epithelial cells.

Bombesin receptor-activated protein (BRAP) is highly expressed in human bronchial epithelial cells. Recent studies have shown that BRAP reduces oxidative stress, inhibits airway inflammation and suppresses nuclear factor kappaB (NF-κB) activity. Mucus overproduction is an important feature in patients with chronic inflammatory airway diseases. Neutrophil elastase (NE) is a potent inducer of mucin5AC (MUC5AC), which is considered the predominant mucin secreted by human airway epithelial cells. Here, we hypothesize that BRAP may regulate NE-induced MUC5AC hypersecretion in a bronchial epithelial cell line (HBE16). We also investigated the underlying mechanism involved in the process. In this study, we found that BRAP was present in HBE16 human bronchial epithelial cells and was significantly increased by NE. Next, we found that the up-regulation of BRAP by pEGFP-N1-BRAP caused a significant decrease in the increased levels of MUC5AC expression, NF-κB activity, and the phosphorylation of extracellular signal-regulated kinases (ERK) and epidermal growth factor receptor (EGFR) induced by NE. Meanwhile, there was a significant decrease in ROS, interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α) levels when BRAP was up-regulated by pEGFP-N1-BRAP. Moreover, when cells were transfected with pEGFP-N1-BRAP and pretreated with NF-κB, ERK or EGFR inhibitors before the NE stimulation, there were further decreased in MUC5AC expression, NF-κB activity, and the phosphorylation of ERK and EGFR. These results suggest that BRAP plays an important role in airway inflammation and its overexpression may regulate NE-induced MUC5AC hypersecretion in HBE16 cells via the EGFR/ERK/NF-κB signaling pathway.

Bisdemethoxycurcumin sensitizes cisplatin-resistant lung cancer cells to chemotherapy by inhibition of CA916798 and PI3K/AKT signaling.

Curcumin, a dietary supplement or herbal medicine from Curcuma longa, has shown antitumor activity in different cancer cell lines and clinical trials. CA916798, a novel protein, is overexpressed in multidrug-resistant tumor cells. This study aimed to assess the effects of curcumin on regulating chemosensitivity in cisplatin-resistant non-small cell lung cancer (NSCLC) cells in vitro and to explore the underlying molecular mechanisms. Human cisplatin-sensitive A549 and cisplatin-resistant A549/CDDP lung adenocarcinoma cells were treated with curcumin to assess cell viability and gene modulations using quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and western blotting. CA916798 shRNA and point mutations were used to assess the CA916798 functions and phosphorylation sites. Bisdemethoxycurcumin sensitized cisplatin-resistant lung cancer cells to various chemotherapeutic agents, including cisplatin. Bisdemethoxycurcumin reduced the levels of CA916798 mRNA and protein in A549 and A549/CDDP cells, while it also suppressed phosphatidylinositol-3-kinase (PI3K)/AKT signaling. CA916798, as a downstream gene, interacted with AKT after bisdemethoxycurcumin treatment in A549 and A549/CDDP cells. Moreover, A549/CDDP cells expressing the point-mutated CA916798-S20D protein were more resistant to cisplatin and bisdemethoxycurcumin, whereas tumor cells expressing CA916798-S20A, CA916798-S31A, CA916798-S60A, CA916798-S93A, or CA916798-T97A (different sites of amino acid phosphorylation) showed similar sensitivity or resistance to cisplatin and bisdemethoxycurcumin, compared with the control cells. Bisdemethoxycurcumin is able to sensitize cisplatin-resistant NSCLC cells to chemotherapeutic agents by inhibition of CA916798 and PI3K/AKT activities. Moreover, phosphorylation of CA916798 at the S20 residue plays a critical role in mediating bisdemethoxycurcumin antitumor activity.

Inhibition of autophagy enhances heat-induced apoptosis in human non-small cell lung cancer cells through ER stress pathways.

The occurrence and mechanisms of autophagy induced by heat stress are not well known in lung cancer cells. Here, we have demonstrated that heat stress induces autophagy in A549 and NCI-H460 cells through morphological and biochemical analyses. The inhibition of autophagy by chloroquine, 3-methyladenine and Beclin 1 siRNA enhanced heat-induced apoptosis. Moreover, the combination of chloroquine and heat stress inhibited tumor growth and enhanced apoptosis in vivo experiments. In addition, heat-induced autophagy involved the ER stress pathway (PERK- or IRE1-dependent). Further, heat treatment led to the increased phosphorylation of AMPK and the decreased phosphorylation of mTOR in vitro and in vivo. Knockdown of GRP78 inhibited the AMPK-mTOR pathway, and the AMPK inhibitor compound C decreased heat-induced autophagy, suggesting that activation of ER stress was involved in autophagy induction and promotion of the AMPK-mTOR pathway. In conclusion, our data suggested that the heat treatment of lung cancer cells triggered protective autophagy, as mediated by ER stress. Thus, inhibition of autophagy can be a promising strategy to enhance hyperthermia in the treatment of lung cancer patients.

Acid-induced autophagy protects human lung cancer cells from apoptosis by activating ER stress.

An acidic tumor microenvironment exists widely in solid tumors. However, the detailed mechanism of cell survival under acidic stress remains unclear. The aim of this study is to clarify whether acid-induced autophagy exists and to determine the function and mechanism of autophagy in lung cancer cells. We have found that acute low pH stimulated autophagy by increasing LC3-positive punctate vesicles, increasing LC3 II expression levels and reducing p62 protein levels. Additionally, autophagy was inhibited by the addition of Baf or knockdown of Beclin 1, and cell apoptosis was increased markedly. In mouse tumors, the expression of cleaved caspase3 and p62 was enhanced by oral treatment with sodium bicarbonate, which can raise the intratumoral pH. Furthermore, the protein levels of ER stress markers, including p-PERK, p-eIF2α, CHOP, XBP-1s and GRP78, were also increased in response to acidic pH. The antioxidant NAC, which reduces ROS accumulation, alleviated acid-mediated ER stress and autophagy, and knocking down GRP78 reduced autophagy activation under acidic conditions, which suggests that autophagy was induced by acidic pH through ER stress. Taken together, these results indicate that the acidic microenvironment in non-small cell lung cancer cells promotes autophagy by increasing ROS-ER stress, which serves as a survival adaption in this setting.

Ezrin/Exocyst complex regulates mucin 5AC secretion induced by neutrophil elastase in human airway epithelial cells.

BACKGROUND/AIM: Increased mucin secretion is a characteristic feature of many chronic airway diseases, particularly during periods of exacerbation; however, the exact mechanism of mucin secretion remains unclear. Ezrin, which is a specific marker of apical membranes, is predominantly concentrated in exocyst-rich cell surface structures, crosslinking the actin cytoskeleton with the plasma membrane. In the present study, we examined whether Ezrin is involved in mucin 5AC (MUC5AC) secretion after neutrophil elastase (NE) attack, and we investigated the role of the exocyst complex docking protein Sec3 in this process. METHODS: NE was used as a stimulator in a 16HBE14o- cell culture model. The expression and location of Ezrin and Sec3 were investigated, and the interaction between Ezrin and Sec3 in 16HBE14o-cells was assayed after treatment with NE, Ezrin siRNA, Sec3 siRNA, neomycin or PIP2-Ab. RESULTS: We found that Ezrin was highly expressed in the bronchi of humans with chronic airway diseases. NE induced robust MUC5AC protein secretion. The Ezrin siRNA, Sec3 siRNA, and neomycin treatments led to impaired MUC5AC secretion in cells. Both Ezrin and Sec3 were recruited primarily to the cytoplasmic membrane after NE stimulation, and the neomycin and PIP2-Ab treatments abrogated this effect. Immunoprecipitation analysis revealed that Ezrin and Sec3 combined to form complexes; however, these complexes could not be detected in Ezrin∆1-333 mutant-transfected cells, even when PIP2 was added. CONCLUSIONS: These results demonstrate that Ezrin/Sec3 complexes are essential for MUC5AC secretion in NE-stimulated airway epithelial cells and that PIP2 is of critical importance in the formation of these complexes.

Autophagy Accompanied with Bisdemethoxycurcumin-induced Apoptosis in Non-small Cell Lung Cancer Cells.

OBJECTIVE: To investigate the effects of bisdemethoxycurcumin (BDMC) on non-small cell lung cancer (NSCLC) cell line, A549, and the highly metastatic lung cancer 95D cells. METHODS: CCK-8 assay was used to assess the effect of BDMC on cytotoxicity. Flow cytometry was used to evaluate apoptosis. Western blot analysis, electron microscopy, and quantification of GFP-LC3 punctuates were used to test the effect of BDMC on autophagy and apoptosis of lung cancer cells. RESULTS: BDMC inhibited the viability of NSCLC cells, but had no cytotoxic effects on lung small airway epithelial cells (SAECs). The apoptotic cell death induced by BDMC was accompanied with the induction of autophagy in NSCLC cells. Blockage of autophagy by the autophagy inhibitor 3-methyladenine (3-MA) repressed the growth inhibitory effects and induction of apoptosis by BDMC. In addition, BDMC treatment significantly decreased smoothened (SMO) and the transcription factor glioma-associated oncogene 1 (Gli1) expression. Furthermore, depletion of Gli1 by siRNA and cyclopamine (a specific SMO inhibitor) induced autophagy. CONCLUSION: Aberrant activation of Hedgehog (Hh) signaling has been implicated in several human cancers, including lung cancers. The present findings provide direct evidence that BDMC-induced autophagy plays a pro-death role in NSCLC, in part, by inhibiting Hedgehog signaling.

Discriminating Lamiophlomis rotata According to Geographical Origin by (1)H-NMR Spectroscopy and Multivariate Analysis.

INTRODUCTION: Lamiophlomis rotata (Duyiwei) is a folk herbal medicine that traditionally has been used in China as a hemostatic agent. Raw plant materials used for medicinal products from different geographical regions are often inconsistent in chemical composition. Metabolic fingerprinting provides a new approach for distinguishing the geographical origins of L. rotata. OBJECTIVE: To identify metabolites that contribute to the different geographical regions of L. rotata samples. METHODS: Lamiophlomis rotata metabolomics were performed by (1)H-nuclear magnetic resonance (NMR) spectroscopy and multivariate statistical analyses. The L. rotata metabolic profile was prepared for NMR measurements using methanol-d4 solvent. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were applied to analyse the L. rotata (1)H-NMR spectroscopy data. RESULTS: Nine iridoid glycosides, one flavonoid and three phenylpropanoid glycosides were detected in L. rotata by (1)H-NMR spectroscopy. (1)H-NMR measurements and multivariate analysis were used to successfully discriminate samples from three different locations. CONCLUSION: The NMR-based analysis of L. rotata is a more comprehensive approach than traditional chromatographic methods. Simple sample preparation, rapidity and reproducibility of are additional advantages of NMR analysis.

[Study on three different species tibetan medicine sea buckthorn by 1H-NMR-based metabonomics].

The 1H-NMR fingerprints of three different species tibetan medicine sea buckthorn were established by 1H-HMR metabolomics to find out different motablism which could provide a new method for the quality evaluation of sea buckthorn. The obtained free induction decay (FID) signal will be imported into MestReNova software and into divide segments. The data will be normalized and processed by principal component analysis and.partial least squares discriminant analysis to perform pattern recognition. The results showed that 25 metabolites belonging to different chemical types were detected from sea buckthorn,including flavonoids, triterpenoids, amino acids, carbohydrates, fatty acids, etc. PCA and PLS-DA analysis showed three different varietiest of sea buckthorn that can be clearly separated by the content of L-quebrachitol, malic acid and some unidentified sugars, which can be used as the differences metabolites of three species of sea buckthorn. 1H-NMR-based metabonomies method had a holistic characteristic with sample preparation and handling. The results of this study can offer an important reference for the species identification and quality control of sea buckthorn.

Novel berberine triazoles: synthesis, antimicrobial evaluation and competitive interactions with metal ions to human serum albumin.

A series of novel berberine triazoles were synthesized and characterized by IR, NMR, MS and HRMS spectra. All target compounds and their precursors were screened for antimicrobial activities in vitro against four Gram-positive bacteria, four Gram-negative bacteria and two fungal strains. Bioactive assay indicated that most of the prepared compounds exhibited good antibacterial and antifungal activities with low MIC values ranging from 2 to 64 µg/mL, which were comparable to or even better than the reference drugs Berberine, Chloromycin, Norfloxacin and Fluconazole. The competitive interactions between compound 5a and metal ions to Human Serum Albumin (HSA) revealed that the participation of Mg(2+) and Fe(3+) ions in compound 5a-HSA association could result in the concentration increase of free compound 5a, shorten the storage time and half-life of compound 5a in the blood, thus improving its antimicrobial efficacy.

Oxidative stress mediates the disruption of airway epithelial tight junctions through a TRPM2-PLCγ1-PKCα signaling pathway.

Oxidative stress has been implicated as an important contributing factor in the pathogenesis of several pulmonary inflammatory diseases. Previous studies have indicated a relationship between oxidative stress and the attenuation of epithelial tight junctions (TJs). In Human Bronchial Epithelial-16 cells (16HBE), we demonstrated the degradation of zonula occludens-1 (ZO-1), and claudin-2 exhibited a great dependence on the activation of the transient receptor potential melastatin (TRPM) 2 channel, phospholipase Cγ1 (PLCγ1) and the protein kinase Cα (PKCα) signaling cascade.

[Effects of glycyrrhizin on airway mucus hypersecretion induced by interleukin-13 in rats].

OBJECTIVE: To explore the effects of glycyrrhizin on airway mucus hypersecretion induced by interleukin-13 (IL-13) in rats. METHODS: A total of 50 SD rats were divided randomly into 5 groups with a random digit table: control group, IL-13 group, and different dosage (25, 50, 75 mg/kg) glycyrrhizin groups. The integral of expression intensity in positive cells of airway epithelium under mucus histochemical stain was calculated with modality-quantitative method. HBE-16 cells were divided into 6 groups: negative control (physiological saline), IL-13 control (10 µg/L IL-13+physiological saline), different concentration glycyrrhizin interference (10 µg/L IL-13+25, 50 and 75 µmol/L glycyrrhizin, respectively) and positive control (10 µg/L IL-13+25 µmol/L zopolrestat). The expression of mucin (MUC) 5AC mRNA, MUC5AC protein, aldose reductase (AR) activity and reactive oxygen species (ROS) content were detected by reverse transcription-polymerase chain reaction (RT-PCR), Western blot, fluorometric method and fluorescence intensity with General Oxidative Stress Indicator (CM-H2DFDA) catheter respectively. RESULTS: In vivo, the integral of expression intensity in positive stain cells of airway epithelium were 0.12 ± 0.03, 0.87 ± 0.13, 0.56 ± 0.08, 0.46 ± 0.06 and 0.35 ± 0.04 respectively while the integral of different dosage glycyrrhizin groups was significantly lower than that of IL-13 group (all P < 0.05) with dose depentency and the IL-13 group was stronger than control group (P < 0.05). In vitro, the index of AR activity and ROS at 48 h of HBE16 cells in every group were 0.156 ± 0.021, 0.692 ± 0.039, 0.436 ± 0.019, 0.323 ± 0.042 and 0.290 ± 0.027; 5.127 ± 0.033, 24.257 ± 3.263, 11.966 ± 0.283, 8.892 ± 0.521 and 6.426 ± 0.173 respectively. The indices of IL-13 control group were higher than those of negative control group (P < 0.05) while those of different concentration glycyrrhizin interference groups were lower than those of IL-13 control group (all P < 0.05). The expressions of MUC5AC mRNA and protein of HBE16 cells in every group were 0.82 ± 0.05, 3.22 ± 0.12, 2.57 ± 0.34, 2.09 ± 0.54 and 1.58 ± 0.22; 0.18 ± 0.04, 0.65 ± 0.15, 0.48 ± 0.11, 0.33 ± 0.19 and 0.26 ± 0.06 respectively. The indices of IL-13 control group were higher than those of negative control group (P < 0.05) and those of different concentration glycyrrhizin interference groups were lower than those of IL-13 control group (P < 0.05). CONCLUSION: Glycyrrhizin may inhibit the expression of MUC5AC mRNA and MUC5AC protein induced by IL-13 and control the hypersecretion of airway mucus.

[Main mediated molecules of airway shear stress-stimulated MUC5AC extracellular secretion].

OBJECTIVE: To explore the main mediated molecules of mucin (MUC) 5AC extracellular secretion stimulated by airway shear stress (SS). METHODS: The 16 human bronchial epithelial (HBE) cells were cultured and randomized divided by Stata software into 5 groups: A. control group; B. SS stimulated group; C. SS stimulated & NSC23766 (a specific inhibitor of Rac-1) incubated group; D. SS stimulated & Cytochalasin D incubated group; E. Cortactin-siRNA (a small interfering RNA of Cortactin) transfected & SS stimulated group. Each group consisted of 6 parallel wells. Triplicate experiments were performed for statistical analysis. Rhythmic rotating device was used to simulate the breathing air flow mediated shear stress. The function of Cortactin was inhibited by Cortactin-siRNA. The relative content of MUC5AC in supernatant was measured by enzyme linked immunosorbent assay (ELISA). The p-Cortactin (phosphorylation Cortactin) relative level, Cortactin relative level and the effect of transfection were measured with Western blotting. And laser confocal microscope was used to observe the polymerization of F-actin. RESULTS: The transfection of Cortactin-siRNA successfully inhibited the function of Cortactin. The relative content of MUC5AC was (0.210 ± 0.013), (0.631 ± 0.025), (0.473 ± 0.112), (0.330 ± 0.067), (0.272 ± 0.019) in groups A, B, C, D and E, the group B was significantly higher than any other group (P = 0.000, 0.043, 0.000, 0.000). The Cortactin relative level in group B (0.670 ± 0.048) was significantly higher than that in group E (0.132 ± 0.014) (P < 0.01). But as compared with groups A, C, D (0.641 ± 0.016, 0.622 ± 0.012, 0.653 ± 0.027), there was no significance (all P > 0.05). The p-Cortactin relative level in group B (0.582 ± 0.067) was significantly higher than that in groups A, C, E (0.131 ± 0.011, 0.393 ± 0.045, 0.170 ± 0.016) (P = 0.000, 0.021, 0.000). But as compared with group D (0.511 ± 0.029), there was no significance (P = 0.246). CONCLUSION: Rac-1, Cortactin and F-actin are the main mediated molecules of airway shear stress-stimulated MUC5AC extracellular secretion.

Regulation of PMA-induced MUC5AC expression by heparin in human bronchial epithelial cells.

Mucus hypersecretion is a major pathophysiologic feature in chronic inflammatory airway diseases. Oxidative stress plays a pivotal role in this process. Recent studies have found that heparin has antioxidant effects which can reduce free radical damage. Here, we hypothesized that heparin has some influence on the expression of mucin 5AC (MUC5AC) induced by phorbol myristate acetate (PMA) in a bronchial epithelial cell line (HBE16), also we have investigated the potential mechanism involved in the process. We found that ROS, the mRNA of Duox1, EGFR and MUC5AC, as well as the protein levels of Duox1, p-EGFR, EGFR, and MUC5AC in the PMA group were significantly increased when compared with the control group (all P < 0.01). After pretreatment with heparin however, there was a significant decrease in ROS levels, the mRNA of Duox1, EGFR, and MUC5AC, and the protein levels of Duox1, p-EGFR, EGFR, and MUC5AC, when compared with the PMA group (all P < 0.01). MUC5AC protein in the supernatant was inhibited in a dose-dependent manner by heparin. Pretreatment with DMTU resulted in a significant decrease in ROS content, the mRNA of Duox1, EGFR, and MUC5AC as well as the protein levels of Duox1, p-EGFR, EGFR, and MUC5AC when compared with the PMA group (all P < 0.01). When cells were pretreated with both heparin and DMTU, there was a further reduction in ROS content, the mRNA of Duox1, EGFR, and MUC5AC as well as the protein levels of Duox1, p-EGFR, EGFR, and MUC5AC, when compared with either the PMA group, heparin group, or DMTU group (all P < 0.01). Our results show that PMA can induce MUC5AC expression by activation of the Duox1-ROS-TACE-TGF-α-EGFR signaling pathway. Heparin can decrease the level of Duox1, ROS production and block the PMA-induced activation of EGFR, thus inhibiting the overexpression of mucin MUC5AC in a dose-dependent manner. In addition to reducing ROS production, heparin may also inhibit the expression of MUC5AC through other signal mechanisms.

Chronic mechanical stress induces mucin 5AC expression in human bronchial epithelial cells through ERK dependent pathways.

Mucus hypersecretion is a common pathological change in chronic inflammatory diseases of the airway. These conditions are usually accompanied by chronic mechanical stress due to airway constriction. Our objective was to study the molecular mechanisms and physical effects of chronic mechanical stress on mucin 5AC (MUC5AC) expression in airway epithelial cells. We exposed normal human bronchial epithelial (NHBE) cells cultured at an air-liquid interface to different degrees of chronic compressive mechanical stress (10, 20, 30 cmH(2)O) for 7 days(1 h per day). MUC5AC protein content was detected by enzyme-linked immunosorbent assay (ELISA). MUC5AC mRNA expression was detected by reverse transcription PCR (RT-PCR) and real-time PCR. The effects of chronic mechanical stress on phosphorylated ERK1/2 (p-ERK1/2), phosphorylated JNK (p-JNK), phosphorylated P38 (p-P38), and phosphorylation of FAK at Tyr397 (p-FAK-Y397), were assessed by Western blot. We also assessed the impact of, an EGFR kinase inhibitor (AG1478), an ERK kinase inhibitor (PD-98059), and short interfering RNA (siRNA) targeted to FAK. We found that transcriptional and protein expression levels of MUC5AC were elevated significantly in the 30 cmH(2)O compressive stress group. p-ERK1/2 increased significantly in response to compressive stress and PD-98059 could attenuated stress-induced MUC5AC expression. p-FAK-Y397 increased significantly in response to compressive stress and FAK siRNA attenuated stress-induced ERK activation strongly. AG1478 attenuated stress-induced ERK activation and MUC5AC expression significantly, but incompletely. Combination of FAK siRNA and AG1478 led to complete attenuation of ERK activation and MUC5AC expression. These results suggest that chronic mechanical stress can enhance MUC5AC expression in human bronchial epithelial cells through the ERK signal transduction pathway. Both FAK and EGFR mediate the mitogenic response induced by mechanical stress in human bronchial epithelial cells through an ERK signaling cascade.

Metabolic discrimination of rhizoma coptidis from different species using 1H NMR spectroscopy and principal component analysis.

Rhizoma coptidis, a broadly used medicinal plant, originates from the dried rhizomes of three species in Chinese pharmacopoeia, namely, Coptis chinensis Franch, Coptis deltoidea C. Y. Cheng et Hsiao, and Coptis teeta Wall. In this study, a novel approach using (1)H NMR spectroscopy combined with multivariate analysis was introduced to differentiate the three species and identify potential metabolic markers for better controlling the quality of rhizoma coptidis. A broad range of metabolites including alkaloids, sugars, organic acids, amino acids, and fatty acids present in rhizoma coptidis were detected by means of (1)H NMR spectroscopy. Principal component analysis (PCA) of the (1)H NMR data set showed a clear separation between all samples by PC1 and PC3, and some metabolites that could be responsible for the discrimination of the three species were identified. An analysis of variance (ANOVA) was performed to statistically verify the significance of differences in metabolite levels between species. By combining PCA and ANOVA, significantly higher contents of palmatine, coptisine, epiberberine, columbamine, and fatty acids together with lower contents of jateorrhizine were found in Coptis chinensis, whereas Coptis deltoidea and Coptis teetA showed the highest levels of sucrose and chlorogenic acid, respectively. This study indicates that metabolites of rhizoma coptidis vary with the species and the proposed method is suitable for metabolic fingerprinting analysis to check the genuine origin of rhizoma coptidis.

Cold temperature induces mucin hypersecretion from normal human bronchial epithelial cells in vitro through a transient receptor potential melastatin 8 (TRPM8)-mediated mechanism.

BACKGROUND: Cold air stimulus is a major environmental factor that exacerbates chronic inflammatory airway diseases, such as chronic obstructive pulmonary disease (COPD) and asthma. At the molecular level, cold is detected by transient receptor potential melastatin 8 (TRPM8). To date, TRPM8 expression has not been characterized in the airway epithelium of patients with COPD. The role of TRPM8 channels in a series of airway responses induced by cold stimuli and the molecular and biochemical pathways of TRPM8 in regulating cold-induced responses are largely unknown. OBJECTIVE: We sought to explore the role of TRPM8 in cold air-provoked mucus hypersecretion and the potential signaling pathway involved in this process. METHODS: The expression of TRPM8 in the bronchial epithelium was examined by means of immunohistochemistry, RT-PCR, and Western blotting. TRPM8 receptor function and hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2) were characterized by means of Ca(2+) imaging and spatiotemporal dynamics of phospholipase C (PLC) δ1-pleckstrin homology-green fluorescent protein, respectively. The expression of MUC5AC mRNA and MUC5AC mucin protein was measured by using real-time PCR and ELISA, respectively. Four serine residues in the myristoylated alanine-rich C kinase substrate (MARCKS)-phosphorylation site domain were mutated to identify the function of MARCKS in TRPM8-mediated airway mucus hypersecretion. RESULTS: TRPM8 protein and mRNA expression were significantly increased in patients with COPD compared with expression seen in healthy subjects. Cold produced robust increases in intracellular Ca(2+) levels and promoted translocation of PLCδ1-pleckstrin homology-green fluorescent protein. Cold increased expression of MUC5AC mRNA and intracellular and secreted MUC5AC protein in a nonsustained way. Phosphorylation site domain-mutant MARCKS cDNA hindered MUC5AC secretion induced by cold. CONCLUSIONS: These results indicate that the TRPM8 receptor is involved in cold-induced mucus hypersecretion through the Ca(2+)-PLC-PIP2-MARCKS signaling pathway.

[Role of neuregulin-1ß in airway hypersecretion induced by in interleukin-1ß].

OBJECTIVE: To explore the role of neuregulin 1ß (NRG-1ß) in airway hypersecretion induced by interleukin (IL)-1ß. METHODS: After stimulating the airway epithelial cell line HBE16 with IL-1ß, the expressions of NRG-1ß mRNA and mucin (MUC) 5AC mRNA were detected by reverse transcription-polymerase chain reaction (RT-PCR), the proteins of NRG-1ß and MUC5AC measured by enzyme-linked immunosorbent assay (ELISA) and phosphorylated erythroblastic leukemia viral oncogene homolog (ErbB)1-4 detected by Western blot. The cells were pre-treated with antibodies of ErbB1-4, inhibitors of p38 mitogen-activated protein kinase (MAPK), ERK1/2, mitogen- and stress-activated protein kinase (MSK)1 and antibody of cAMP-response element-binding protein (CREB). After the addition of stimulant NRG-1ß, MUC5AC was measured by ELISA. RESULTS: IL-1ß could increase markedly the levels of NRG-1ß mRNA and MUC5AC mRNA and also the proteins of NRG-1ß and MUC5AC in a dose-dependent fashion. NRG-1ß at concentrations of 1, 10, 100, 200 nmol/L increased the expression of MUC5AC (0.328 ± 0.055, 0.364 ± 0.086, 0.650 ± 0.134, 0.586 ± 0.068) versus the control group (0.227 ± 0.019). And the results had statistical significances (P < 0.05). The expressions of phosphorylated ErbB2 and ErbB3 stimulated by NRG-1ß were positive while those of phosphorylated ErbB1 and ErbB 4 negative. After a pretreatment of antibodies of ErbB2, ErbB3, inhibitors of p38MAPK, ERK1/2, MSK1 and antibody of CREB and a stimulation of NRG-1ß, the expression of MUC5AC decreased (0.221 ± 0.033, 0.238 ± 0.044, 0.386 ± 0.021, 0.352 ± 0.022, 0.294 ± 0.017, 0.252 ± 0.019) versus the NRG-1ß group (0.650 ± 0.134). And the results had statistical significances (P < 0.05). CONCLUSION: IL-1ß may cause airway hypersecretion probably through the combination of NRG-1ß with ErbB2 and ErbB3 heterodimers and the activation of MAPK/MSK1/CREB signal conduction.

[Acrolein decreases SUMO modification of glucocorticoid receptor and reduces its sensitivity to corticosteroids in airway hypersecretion].

OBJECTIVE: To explore the variation of small ubiquitin-related modification (SUMO) level of glucocorticoid receptors (GRs) exposed to acrolein stimulation as well as the influence of the variation on mucus hypersecretion. METHODS: The recombinant plasmid was constructed by inserting small ubiquitin-like modifier 1 (SUMO1) cDNA into eukaryotic expression plasmid pcDNA3.1-EGFP with a flag sequence marker. The recombinant plasmid pcDNA3.1-EGFP-flag-SUMO1 was identified by enzyme digestion analysis. The 16HBE cells were cultured and randomized divided into 9 following groups: A. control; B. acrolein stimulated; C. dexamethasone incubated; D. acrolein stimulated and dexamethasone incubated; E. SUMO1 transfected; F. pcDNA3.1-EGFP vector transfected; G. SUMO1 transfected and acrolein stimulated; H. SUMO1 transfected, acrolein stimulated and dexamethasone incubated; I. pcDNA3.1-EGFP vector transfected, acrolein stimulated and dexamethasone incubated. Each group consisted of 5 parallel wells and experiments were repeated for 4 times for statistical analysis. The transfection efficiency was evaluated by the expression of enhanced green fluorescent protein (EGFP) via fluorescence microscope. The SUMO modification level of GRs was measured with co-immunoprecipitation and Western blot. The transcription level of mucin (MUC) 5AC was evaluated with reverse transcription-polymerase chain reaction (RT-PCR). The MUC5AC secreted in supernatant was measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: The SUMO modification level was much lower in group B (0.079 ± 0.023) than that in group A (0.446 ± 0.068) (t = -23.13, P = 0.000) and in group D (0.574 ± 0.018) than that in group C (0.843 ± 0.028) (t = -36.34, P = 0.000). The transcription level of MUC5AC was significantly lower in group H (0.330 ± 0.063) than group D (0.617 ± 0.190) (q = -7.80, P = 0.000). Through ELISA, there was no significance between groups G and B in the term of secretion level of MUC5AC. While the secretion level of MUC5AC was much lower in group H ((0.416 ± 0.092) µg/L) than group D ((0.663 ± 0.104) µg/L) and group G ((0.740 ± 0.343) µg/L) (q = -7.31, -9.59; P = 0.001, 0.000). CONCLUSION: Acrolein decreases the SUMO modification of GRs and reduces the inhibitory effect of dexamethasone on the transcription of MUC5AC.