Effects of human umbilical cord blood mononuclear cells on ovalbumin-induced asthma in mice.

Background: Umbilical cord blood mononuclear cells (UCMNCs) show broad immune-modulation effects, which may be helpful for treating asthma. Effects of UCMNCs on asthma were investigated with mouse model in present study. Methods: Asthma was induced in BALB/c mice by ovalbumin (OVA) immunization and challenge. Asthmatic mice were then treated on days 7 and 20 with intravenous injections of UCMNCs in doses of 4×105, 2×106, and 107 cells per mouse for the low-dose UCMNC (UCMNCL), medium-dose UCMNC (UCMNCM), and high-dose UCMNC (UCMNCH) groups, respectively. Fetal mouse blood mononuclear cells (FMMNCs) were administered to FMMNC group at a dose of 2×106 cells per mouse as approximate allograft control. Airway hyperresponsiveness (AHR), airway inflammation indexes, and CD4/CD8 T cell subsets were measured at day 25. Results: Compared with the model group, AHR in the UCMNCL group, inflammation score of lung tissue in the UCMNCM group, interleukin (IL)-5 in bronchoalveolar lavage fluid (BALF) in UCMNCL group, IL-5 and IL-13 in BALF in UCMNCM group, and IL-17 in serum in UCMNCH group were significantly inhibited. Compared with the model group, CD4+CD8+ T cells were reduced in the UCMNCL group, while decrease of CD4-CD8- T cells and increase of CD4+CD8- T cells were further strengthened in UCMNCM group. FMMNC treatment significantly reduced the IL-13 and IL-17 in serum, decreased CD4-CD8- and CD4+CD8- T cells, and increased the CD4+CD8+ and CD4-CD8+ T cells in BALF. Conclusions: UCMNCs can modulate AHR, T-helper (Th)2 inflammation, and airway injury in experimental asthma at appropriate dose.

Autologous Airway Basal Cell Transplantation Alleviates Airway Epithelium Defect in Recurrent Benign Tracheal Stenosis.

BACKGROUND: Airway epithelium defects are a hallmark of recurrent benign tracheal stenosis (RBTS). Reconstructing an intact airway epithelium is of great importance in airway homeostasis and epithelial wound healing and has great potential for treating tracheal stenosis. METHODS: An experimental study was conducted in canines to explore the therapeutic effect of autologous basal cell transplantation in restoring airway homeostasis. First, airway mucosae from human patients with recurrent tracheal stenosis were analyzed by single-cell RNA sequencing. Canines were then randomly divided into tracheal stenosis, Stent, Stent + Cells, and Stent + Cells + Biogel groups. Autologous airway basal cells of canines in the Stent + Cells and Stent + Cells + Biogel groups were transplanted onto the stenotic airway after modeling. A biogel was coated on the airway prior to basal cell transplantation in the Stent + Cells + Biogel group. After bronchoscopic treatments, canines were followed up for 16 weeks. RESULTS: Single-cell RNA sequencing demonstrated packed airway basal cells and an absence of normal airway epithelial cells in patients with RBTS. Autologous airway basal cell transplantation, together with biogel coating, was successfully performed in the canine model. Follow-up observation indicated that survival time in the Stent + Cells + Biogel group was significantly prolonged, with a higher (100%) survival rate compared with the other groups. In terms of pathological and bronchoscopic findings, canines that received autologous basal cell transplantation showed a reduction in granulation hyperplasia as well as airway re-epithelialization with functionally mature epithelial cells. CONCLUSIONS: Autologous airway basal cell transplantation might serve as a novel regenerative therapy for airway re-epithelialization and inhibit recurrent granulation hyperplasia in benign tracheal stenosis.

Mechanical stretch promotes apoptosis and impedes ciliogenesis of primary human airway basal stem cells.

BACKGROUND: Airway basal stem cells (ABSCs) have self-renewal and differentiation abilities. Although an abnormal mechanical environment related to chronic airway disease (CAD) can cause ABSC dysfunction, it remains unclear how mechanical stretch regulates the behavior and structure of ABSCs. Here, we explored the effect of mechanical stretch on primary human ABSCs. METHODS: Primary human ABSCs were isolated from healthy volunteers. A Flexcell FX-5000 Tension system was used to mimic the pathological airway mechanical stretch conditions of patients with CAD. ABSCs were stretched for 12, 24, or 48 h with 20% elongation. We first performed bulk RNA sequencing to identify the most predominantly changed genes and pathways. Next, apoptosis of stretched ABSCs was detected with Annexin V-FITC/PI staining and a caspase 3 activity assay. Proliferation of stretched ABSCs was assessed by measuring MKI67 mRNA expression and cell cycle dynamics. Immunofluorescence and hematoxylin-eosin staining were used to demonstrate the differentiation state of ABSCs at the air-liquid interface. RESULTS: Compared with unstretched control cells, apoptosis and caspase 3 activation of ABSCs stretched for 48 h were significantly increased (p < 0.0001; p < 0.0001, respectively), and MKI67 mRNA levels were decreased (p < 0.0001). In addition, a significant increase in the G0/G1 population (20.2%, p < 0.001) and a significant decrease in S-phase cells (21.1%, p < 0.0001) were observed. The ratio of Krt5+ ABSCs was significantly higher (32.38% vs. 48.71%, p = 0.0037) following stretching, while the ratio of Ac-tub+ cells was significantly lower (37.64% vs. 21.29%, p < 0.001). Moreover, compared with the control, the expression of NKX2-1 was upregulated significantly after stretching (14.06% vs. 39.51%, p < 0.0001). RNA sequencing showed 285 differentially expressed genes, among which 140 were upregulated and 145 were downregulated, revealing that DDIAS, BIRC5, TGFBI, and NKX2-1 may be involved in the function of primary human ABSCs during mechanical stretch. There was no apparent difference between stretching ABSCs for 24 and 48 h compared with the control. CONCLUSIONS: Pathological stretching induces apoptosis of ABSCs, inhibits their proliferation, and disrupts cilia cell differentiation. These features may be related to abnormal regeneration and repair observed after airway epithelium injury in patients with CAD.

High freezing rate improves flavor fidelity effect of hand grab mutton after short-term frozen storage.

Taking the eutectic point as the final freezing temperature, the differences of flavor substances of in hand grab mutton (HGM) frozen at three rates of 0. 26 cm/h (-18°C), 0.56 cm/h (-40°C) and 2.00 cm/h (-80°C) were determined and analyzed. The results showed that the flavor of HGM decreased significantly after freezing. With the increase of freezing rate, the contents of aldehydes, alcohols, ketones, acids, esters, others, free amino acids and 5'-nucleotides were higher, and the content of specific substances was also generally increased. All samples from unfrozen and frozen HGM could be divided into four groups using an electronic nose based on different flavor characteristics. Seven common key aroma components were determined by relative odor activity value (ROAV), including hexanal, heptanal, octanal, nonanal, (E)-oct-2-enal, (2E,4E)-deca-2,4-dienal and oct-1-en-3-ol. The higher the freezing rate, the greater the ROAVs. Taste activity values calculated by all taste substances were far <1, and the direct contribution of the substances to the taste of HGM was not significant. The equivalent umami concentration of HGM frozen at -80°C was the highest. These findings indicated that higher freezing rate was more conducive to the retention of flavor substances in HGM, and the flavor fidelity effect of freezing at -80°C was particularly remarkable.

A clinical and canine experimental study in small-airway response to bronchial thermoplasty: Role of the neuronal effect.

BACKGROUND: The effects of bronchial thermoplasty (BT) on smooth muscle (SM) and nerves in small airways are unclear. METHODS: We recruited 15 patients with severe refractory asthma, who received BT treatment. Endobronchial optical-coherence tomography (EB-OCT) was performed at baseline, 3 weeks' follow-up and 2 years' follow-up to evaluate the effect of BT on airway structure. In addition, we divided 12 healthy beagles into a sham group and a BT group, the latter receiving BT on large airways (inner diameter >3 mm) of the lower lobe. The dogs' lung lobes were resected to evaluate histological and neuronal changes of the treated large airways and untreated small airways 12 weeks after BT. RESULTS: Patients receiving BT treatment had significant improvement in Asthma Control Questionnaire (ACQ) scores and significant reduction in asthma exacerbations. EB-OCT results demonstrated a notable increase in inner-airway area (Ai) and decrease in airway wall area percentage (Aw%) in both large (3rd-to 6th-generation) and small (7th-to 9th-generation) airways. Furthermore, the animal study showed a significant reduction in the amount of SM in BT-treated large airways but not in untreated small airways. Protein gene product 9.5 (PGP9.5)-positive nerves and muscarinic receptor 3 (M3 receptor) expression in large and small airways were both markedly decreased throughout the airway wall 12 weeks after BT treatment. CONCLUSIONS: BT significantly reduced nerves, but not SM, in small airways, which might shed light on the mechanism of lung denervation by BT.

A simple and sensitive HPLC-MS/MS assay for the quantitation of montelukast in cell-based systems in vitro pulmonary drug permeability study.

Montelukast is a potent and selective antagonist of the cysteinyl leukotriene receptor 1 subtype (CysLT1) and widely used in the form of oral tablets and granules for asthma prophylaxis and treatment. Recently, due to the pulmonary inhaled administration can limit montelukast distribution in the systemic circulation, avoid the first-pass metabolism and have better therapeutic effects in respiratory disease treatment, explore alternative routes of administration, like delivery of montelukast via an inhaled, is a new research trend for montelukast. The aim of the current study was to develop and validate a simple, accurate, highly sensitive and selective liquid chromatography-tandem mass spectrometry method (LC-MS/MS) for determination of montelukast in an in vitro cell-based pulmonary pharmacokinetics system model, which can be used to be a better understanding the fate of inhaled montelukast in the lungs. In this study, montelukast was extracted by protein precipitation with acetonitrile containing labeled montelukast. The chromatography was performed on an Agilent Eclipse plus C8 column (4.6 mm × 100 mm, 3.5 µm, Darmstadt, Germany) operating at 35 ◦C. The mobile phase consisted of acetonitrile: 20 mM ammonium formate buffer (80: 20, v/v), was delivered at a flow rate of 0.5 mL/min. montelukast and the internal standard were both eluted at 4.2 min. A linear (1/x2) relationship was used to perform the calibration over an analytical range from 0.5 to 600 ng/mL. The intra- and inter-batch precision expressed as CV for four QC samples including LLOQ range from 1.14 % to 6.25 %. The intra- and inter-batch accuracy for four concentrations of montelukast were in the range of 95.19%-104.1%. All the values for accuracy and precision were within the acceptance range. The method met all the bioanalytical method validation requirements by ICH and was suitable for the assay of montelukast which in the in vitro cell-based pulmonary pharmacokinetics system model.

STAT1 participates in the induction of substance P expression in airway epithelial cells by respiratory syncytial virus.

PURPOSE: The regulation effect and mechanism of respiratory syncytial virus (RSV) infection on the expression of tachykinin substance P (SP) in airway epithelial cells was investigated. METHODS: The regulation of SP expression by RSV was investigated in the BEAS-2B airway epithelial cell line. RT-qPCR, immunofluorescence, and ELISA assay were used to examine the expression of the SP encoding gene TAC1, the intracellular SP protein expression, and the extracellular SP secretion. RESULTS: The mRNA expression of TAC1 and the intracellular SP protein level in BEAS-2B cells were significantly enhanced by RSV infection with multiplicity of infection (MOI) values of both 1 and 0.1 at 48 hours post infection. Heat-inactivated and UV-inactivated RSV, but not live RSV, significantly induced SP secretion in both control BEAS-2B cells and CX3CR1 receptor knockout cells without affecting the TAC1 gene expression or cell viability. RSV G protein (2-10 µg/ml) and fractalkine (10-50 ng/ml), both CX3CR1 receptor ligands, did not affect SP secretion in BEAS-2B cells. Inhibition of STAT1 phosphorylation by fludarabine (1 µM) markedly reduced the RSV-induced TAC1 gene expression and antagonized the inhibition of RSV replication by interferon-α in BEAS-2B cells. CONCLUSIONS: STAT1 participates in RSV infection-induced SP expression in airway epithelial cells.

Protective Effect of Citrulline on the Hearts of Rats with Sepsis Induced by Cecal Ligation and Puncture.

PURPOSE: To investigate the protective effect of citrulline (Cit) on the hearts of rats with sepsis. METHODS: Wistar rats were divided into the normal, sham-operated, CLP, Cit, and CLP+Cit groups. Routine blood tests were performed, and the blood biochemical indexes were measured. Pathological changes in the cardiac tissues were observed. The levels of NO and iNOS in blood and SOD activity and MDA levels in the heart were measured. RESULTS: Less inflammatory cell infiltration of the myocardial fibers and significantly decreased white blood cell count, absolute neutrophil count, neutrophil percentage, CK, HBDH, and NO (all P<0.05) were detected in the CLP+Cit group compared with the CLP group. In addition, SOD activity and MDA levels in heart tissues were, respectively, higher and lower in the CLP+Cit group than in the CLP group (both P<0.05). CONCLUSIONS: Cit reduces pathological damage in the heart and enhances the heart's antioxidant capacity, thereby protecting cardiomyocytes.

Performance evaluation of detecting circulating tumor cells and tumor cells in bronchoalveolar lavage fluid in diagnosis of peripheral lung cancer.

BACKGROUND: To evaluate the diagnostic performances of detecting circulating tumor cells (CTCs) and tumor cells in bronchoalveolar lavage fluid (BALF) for peripheral lung cancer. METHODS: A total of 247 patients with lung cancer and 70 cases with benign lung disease were recruited in this study. Peripheral blood and BALF samples were collected, in which the tumor cells were enriched by negative immunomagnetic selection and detected by fluorescence in situ hybridization (FISH) of chromosome enumeration probe 8 (CEP8). The levels of tumor-associated markers (e.g., CEA, CA125, and NSE) in peripheral blood plasma were measured by using electrochemiluminescence. RESULTS: The numbers of CTCs detected in peripheral blood were significantly higher in patients with lung cancer than those with benign lung disease (5.78±0.57 vs. 1.13±0.39, Z=-8.64, P<0.01). Similarly, tumor cells count in BALF of malignancy were higher than that of benign lesions (6.76±0.89 vs. 0.89±0.23, Z=-6.254, P<0.01). However, as for patients with lung cancer and benign lung disease, the numbers of tumor cells in peripheral blood were comparable with those in BALF (both P>0.05). Detecting CTCs and tumor cells in BALF had similar areas under curves (AUC =0.871 and 0.963, respectively; P>0.05) in discriminating benign lesions from lung cancer (sensitivity 83.8% and 92.6%, specificity 86.5% and 99.9%, respectively), both of which were larger than those of NSE, CEA, and CA125 (AUC =0.564, 0.512 and 0.554, respectively; all P<0.05). The diagnostic performances of discriminating benign lesions and lung cancer in BALF and peripheral blood were both in concordance with that of histopathology (kappa values 0.662 and 0.569, respectively; both P<0.001). CONCLUSIONS: Detecting tumor cells in peripheral blood and BALF may sensitive to identify benign and malignant peripheral lung lesions and be of value for early diagnosis of lung cancer.

Systematic review of partial hepatic resection to treat hepatic metastases in patients with gastric cancer.

OBJECTIVE: To examine overall survival and mortality following hepatic resection in patients with hepatic metastases from gastric cancer. METHODS: EMBASE, PubMed, Web of Science, and Cochrane databases were systematically searched for publications involving more than 10 patients who underwent hepatic resection to treat hepatic metastases from gastric cancer and who did not have peritoneal disease or involvement of other distant organs. RESULTS: A total of 39 studies were included, involving a median of 21 hepatic resections (range, 10-64). Resection was associated with median 30-day morbidity of 24% (range, 0%-47%) and 30-day mortality of 0% (range, 0%-30%). Median overall survival was 68% at 1 year, 31% at 3 years, and 27% at 5 years. Asian studies reported higher rates than Western studies for overall survival at 1 year (73% vs 59%), 3 years (34% vs 25%), and 5 years (27% vs 17%). Compared with palliative treatment, resection was associated with significantly lower mortality at 1 year (risk ratio [RR] 0.47, P < 0.001) and 2 years (RR 0.70, P < 0.001). CONCLUSION: Patients with hepatic metastases from gastric cancer may benefit from hepatic resection in case of good physical condition, absence of peritoneal dialysis, and optimum liver function with single metastases. More trials are needed to confirm this finding.

Does Citrulline Have Protective Effects on Liver Injury in Septic Rats?

Citrulline (Cit) supplementation was proposed to serve as a therapeutic intervention to restore arginine (Arg) concentrations and improve related functions in sepsis. This study explored whether citrulline had positive effects on liver injury and cytokine release in the early stages of sepsis. The cecal ligation and puncture (CLP) model was utilized in our study. Rats were divided into four groups: normal, Cit, CLP, and CLP+Cit. The CLP group and CLP+Cit group were separated into 6-, 12-, and 24-hour groups, according to the time points of sacrifice after surgery. Intragastric administration of L-citrulline was applied to rats in Cit and CLP+Cit groups before surgery. Serum AST and ALT levels and levels of MDA, SOD, NO, and iNOS in the liver tissues were evaluated. Plasma concentrations of Cit and Arg were assessed using HPLC-MS/MS. Serum concentrations of cytokines and chemokines were calculated by Luminex. Results showed SOD activities of CLP+Cit groups were significantly higher than that of CLP groups, contrasting with the MDA and NO levels which were significantly lower in CLP+Cit groups than in CLP groups. In addition, plasma concentrations of TNF-α, IL-6, and IL-1ß were significantly lower in the CLP+Cit 6-hour group than in the CLP 6-hour group.

The Specific Roles of JAK/STAT Signaling Pathway in Sepsis.

The Janus kinase-signal transducer and activator of transcription (JAK/STAT) pathway is a principal signaling pathway for the signal transduction of many pivotal cytokines involved in sepsis. Binding of cytokines to corresponding receptors can activate associated JAK kinases, which selectively phosphorylate STATs. Activated STATs then translocate to the nucleus and play a critical role in the transcription of target genes. During the past several years, significant progress has been made in the understanding of the roles of JAK/STAT pathway in sepsis. The aims of this review are to describe the present knowledge about JAK/STAT signaling pathway, describe the specific roles of JAK/STAT pathway in sepsis, and put forward the prospect for future studies of JAK/STAT signaling pathway in sepsis. A PubMed database search was performed for studies of JAKs and STATs in sepsis. It has been shown that a variety of cytokines can exert their biological effects via the JAK/STAT signaling pathway. JAK/STAT pathway has been shown related to the release of various cytokines and inflammatory mediators and involved in the regulation of immune response in sepsis. Moreover, JAK/STAT pathway has been shown involved in organ damage and other dysfunctions in sepsis models.

Effects of four antitussives on airway neurogenic inflammation in a guinea pig model of chronic cough induced by cigarette smoke exposure.

OBJECTIVE: The effects of four antitussives, including codeine phosphate (CP), moguisteine, levodropropizine (LVDP) and naringin, on airway neurogenic inflammation and enhanced cough were investigated in guinea pig model of chronic cough. METHODS: Guinea pigs were exposed to CS for 8 weeks. At the 7th and 8th week, the animals were treated with vehicle, CP (4.8 mg/kg), moguisteine (24 mg/kg), LVDP (14 mg/kg) and naringin (18.4 mg/kg) respectively. Then the cough and the time-enhanced pause area under the curve (Penh-AUC) during capsaicin challenge were recorded. The substance P (SP) content, NK-1 receptor expression and neutral endopeptidase (NEP) activity in lung were determined. RESULTS: Chronic CS exposure induced a bi-phase time course of cough responsiveness to capsaicin. Eight weeks of CS exposure significantly enhanced the airway neurogenic inflammation and cough response in guinea pigs. Two weeks of treatment with CP, moguisteine, LVDP or naringin effectively attenuated the chronic CS-exposure enhanced cough. Only naringin exerted significant effect on inhibiting Penh-AUC, SP content and NK-1 receptor expression, as well as preventing the declining of NEP activity in lung. CONCLUSIONS: Chronic CS-exposed guinea pig is suitable for studying chronic pathological cough, in which naringin is effective on inhibiting both airway neurogenic inflammation and enhanced cough.

Protective effects of naringin against paraquat-induced acute lung injury and pulmonary fibrosis in mice.

The present study evaluates protective effects of naringin against paraquat (PQ)-induced acute lung injury (ALI) and pulmonary fibrosis in mice. Survival probability against PQ intoxication was tested by a single intraperitoneal injection of PQ. Results showed that survival rates of mice exposed to PQ only (50 mg/kg within 7 days) were much lower than that in mice daily treatment with NAC or naringin. Moreover, protection against PQ-induced ALI was tested by daily pretreatment mice with saline, NAC or naringin for 3 days before PQ (30 mg/kg, i.p.). Results showed that increase in leukocytes infiltration and overexpressions of TNF-α and TGF-ß1 caused by 8h of PQ exposure were dose-dependently ameliorated by naringin. Furthermore, protection against PQ-induced pulmonary fibrosis was tested by pretreatment mice with PQ (20 mg/kg, i.p.), and then daily administration with saline, NAC or naringin for prolonged 21 days. Results showed that naringin of 60 and 120 mg/kg significantly reduced PQ-induced upregulations of TNF-α, TGF-ß1, MMP-9 and TIMP-1, levels of pulmonary malonaldehyde and hydroxyproline, as well as pulmonary fibrosis deposition, while increased activities of SOD, GSH-Px and HO-1. These results indicated that naringin had effective protection against PQ-induced ALI and pulmonary fibrosis.

Anti-inflammatory effects of naringin in chronic pulmonary neutrophilic inflammation in cigarette smoke-exposed rats.

Naringin, a well-known flavanone glycoside of grapefruit and citrus fruits, was found to be as an effective anti-inflammatory compound in our previous lipopolysaccharide-induced acute lung injury mouse model via blockading activity of nuclear factor κB. The current study sought to explore the anti-inflammatory effects of naringin on chronic pulmonary neutrophilic inflammation in cigarette smoke (CS)-induced rats. Seventy Sprague-Dawley rats were randomly divided into seven groups to study the effects of CS with or without various concentrations of naringin or saline for 8 weeks. The results revealed that naringin supplementation at 20, 40, and 80 mg/kg significantly increased body weight of CS-induced rats as compared to that in the CS group. Moreover, naringin of 20, 40, and 80 mg/kg prevented CS-induced infiltration of neutrophils and activation of myeloperoxidase and matrix metalloproteinase-9, in parallel with suppression of the release of cytokines, such as tumor necrosis factor-α and interleukin-8 (IL-8). IL-10 in bronchoalveolar lavage fluid was significantly suppressed after CS exposure, but dose dependently elevated by naringin. The results from hematoxylin and eosin staining revealed that naringin dose dependently reduced CS-induced infiltration of inflammatory cells, thickening of the bronchial wall, and expansion of average alveolar airspace. In conclusion, our data suggest that naringin is an effective anti-inflammatory compound for attenuating chronic pulmonary neutrophilic inflammation in CS-induced rats.

Naringin attenuates EGF-induced MUC5AC secretion in A549 cells by suppressing the cooperative activities of MAPKs-AP-1 and IKKs-IκB-NF-κB signaling pathways.

Naringenin, the aglycone of naringin, has been reported to attenuate MUC5AC secretion by inhibiting activity of nuclear factor kappa B (NF-κB) via EGFR-PI3K-Akt/ERK MAPKinase signaling pathways. However, previous studies demonstrated that the MUC5AC promoter was located in two different regions: an activator protein-1 (AP-1) binding site and a NF-κB binding site. The current study comprehensively determined the involvement of MAPKs/AP-1 and IKKs/IκB/NF-κB in epidermal growth factor (EGF)-induced A549 cells, and sought to ascertain the signaling pathways of naringin imparted in suppression of EGF-induced MUC5AC secretion. The results showed that naringin of 100 µM not only significantly decreased EGF-induced overexpressions of both MUC5AC mucin and mRNA in A549 cells, but also suppressed the phosphorylation of EGF receptor, p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase (ERK1/2), and c-Jun N-terminal kinase (JNK), as well as nucleus NF-κB p65 and AP-1. Moreover, any of three MAPKs inhibitors (PD98059, SB203580, and SP600125) significantly inhibited EGF-induced MUC5AC secretion. And as compared to MG132, the inhibitor κB (IκB) phosphorylation inhibitor of SN50 was more effective in reducing EGF-induced MUC5AC secretion because of suppression of nucleus AP-1. Meanwhile, as compared to naringin, both SP600125 and azithromycin were less effective in suppressing EGF-induced secretion of MUC5AC because of the unchanged nucleus NF-κB p65. These results indicated that naringin attenuates EGF-induced MUC5AC secretion in A549 cells by suppressing the cooperative activities of MAPKs/AP-1 and IKKs/IκB/NF-κB signaling pathways.

Characteristic comparison of three rat models induced by cigarette smoke or combined with LPS: to establish a suitable model for study of airway mucus hypersecretion in chronic obstructive pulmonary disease.

There is a need of in vivo COPD models for mucus hypersecretion study. The current study compared three rat models induced by cigarette smoke (CS) exposure alone or combined with pre- or post-treatment with lipopolysaccharide (LPS). Forty rats were randomly divided into the four following groups: control group, LPS + CS group (CS exposure for 4-wk combined with LPS pretreatment), CS group (CS exposure for 6-wk), CS + LPS group (CS exposure for 6-wk combined with LPS post-treatment). The results showed that both CS and CS + LPS groups had more severe pro-inflammatory cytokines secretion, inflammatory cells infiltration, and emphysema as compared to that in LPS + CS group animals. From the PAS staining sections, we found a remarkable hyperplasia of goblet-cell in epitheliums of trachea, bronchi, and bronchiole of all of three modeling groups, especially in CS and CS + LPS groups. From the western-blotting results, there were significant increase in the activities of NF-κB, AP-1, EGFR, TLR4, and MAPKs in all of three modeling groups, while HDAC2 activity was remarkably repressed in CS group only. Moreover, the expression and secretion of MUC5AC were exhibited significant increase in all of three modeling groups, which correlated well with the total transcription activity integration of NF-κB, AP-1, and HDAC2 (r = 0.946, p < 0.01). These results indicated that MUC5AC hypersecretion is consistent with activation of EGFR-AP-1/NF-κB and TLR4-AP-1/NF-κB signaling pathways, as well as repression of HDAC2 activity. Based on these results, we speculated that the 6-wk CS exposure rat model is a reliable COPD rat model, while the 6-wk CS exposure combined with LPS post-treatment rat model is a suitable COPD exacerbation model for mucus hypersecretion study.

Naringin attenuates enhanced cough, airway hyperresponsiveness and airway inflammation in a guinea pig model of chronic bronchitis induced by cigarette smoke.

Naringin is a flavanone with various bioactivities including expectorant effect, antitussive effect and inhibitory effects on asthma and acute lung injury. In present study we examined the effects of naringin on enhanced cough, airway hyperresponsiveness (AHR) and airway inflammation in chronic cigarette smoke (CS) exposure-induced chronic bronchitis in guinea pigs. To achieve this, guinea pigs were exposed to CS for 8weeks (10cigarettes/day, 6days/week). Oral administration of naringin (9.2, 18.4 and 36.8mg/kg) significantly attenuated the enhanced cough and AHR in smoke-exposed guinea pigs, reduced the concentrations of interleukin-8 (IL-8), leukotriene B4 (LTB4) and tumor necrosis factor-α (TNF-α) in bronchoalveolar lavage fluid (BALF) and decreased the myeloperoxidase (MPO) activity in both BALF and lung tissue, but did not significantly decrease the leukocytes in BALF. Naringin also improved superoxidase dismutase (SOD) activity in lung tissue and increased the content of lipoxin A4 (LXA4) in BALF in this guinea pig model of chronic bronchitis. These results suggested that naringin exhibited antitussive, anti-AHR and anti-inflammation effects on chronic CS exposure-induced chronic bronchitis in guinea pigs, and may possess novel therapeutic potential in the treatment of chronic bronchitis.