Inhibition of TAK1 aggravates airway inflammation by increasing RIPK1 activity and promoting macrophage death in a mouse model of toluene diisocyanate-induced asthma / 南方医科大学学报

OBJECTIVE@#To explore the effect of transforming growth factor-β (TGF-β)-activated kinase 1 (TAK1) on toluene diisocyanate (TDI)-induced allergic airway inflammation in mice.@*METHODS@#Thirty-two mice were randomly divided into AOO group, AOO+5Z-7-Oxozeaenol group, TDI group, and TDI+5Z-7-Oxozeaenol group. Another 32 mice were randomly divided into AOO group, TDI group, TDI +5Z-7-Oxozeaenol group, and TDI +5Z-7-Oxozeaenol + Necrostatin-1 group. TAK1 inhibitor (5Z-7-Oxozeaenol, 5 mg/kg) and/or RIPK1 inhibitor (Necrostatin-1, 5 mg/kg) were used before each challenge. Airway responsiveness, airway inflammation and airway remodeling were assessed after the treatments. We also examined the effect of TDI-human serum albumin (TDI-HSA) conjugate combined with TAK1 inhibitor on the viability of mouse mononuclear macrophages (RAW264.7) using CCK8 assay. The expressions of TAK1, mitogen-activated protein kinase (MAPK) and receptor interacting serine/threonine protease 1 (RIPK1) signal pathway in the treated cells were detected with Western blotting. The effects of RIPK1 inhibitor on the viability of RAW264.7 cells and airway inflammation of the mouse models of TDI-induced asthma were evaluated.@*RESULTS@#TAK1 inhibitor aggravated TDI-induced airway inflammation, airway hyper responsiveness and airway remodeling in the mouse models (P < 0.05). Treatment with TAK1 inhibitor significantly decreased the viability of RAW264.7 cells, which was further decreased by co-treatment with TDI-HSA (P < 0.05). TAK1 inhibitor significantly decreased the level of TAK1 phosphorylation and activation of MAPK signal pathway induced by TDI-HSA (P < 0.05). Co-treatment with TAK1 inhibitor and TDI-HSA obviously increased the level of RIPK1 phosphorylation and caused persistent activation of caspase 8 (P < 0.05). RIPK1 inhibitor significantly inhibited the reduction of cell viability caused by TAK1 inhibitor and TDI-HSA (P < 0.05) and alleviated the aggravation of airway inflammation induced by TAK1 inhibitors in TDI-induced mouse models (P < 0.05).@*CONCLUSION@#Inhibition of TAK1 aggravates TDI-induced airway inflammation and hyperresponsiveness and may increase the death of macrophages by enhancing the activity of RIPK1 and causing persistent activation of caspase 8.

Receptor for advanced glycation end products upregulates MUC5AC expression and promotes mucus overproduction in mice with toluene diisocyanate-induced asthma / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the role of the receptor for advanced glycation end products (RAGE) in regulating the expression of MUC5AC and mucus production in a mouse model of toluene diisocyanate (TDI)?induced asthma.</p><p><b>METHODS</b>BALB/c mice were randomly divided into control group, vehicle (AOO) group, TDI?induced asthma group and RAGE inhibitor (FPS?ZM1) group. PAS staining, Western blotting, and immunohistochemistry were used to analyze the changes in mucus production and MUC5AC expression in the airway of the mice, and the expression of p?ERK was detected with Western blotting. In vitro cultured human bronchial epithelial cell line 16HBE was transfected with lentiviral vector carrying short hairpin RNA targeting RAGE (shRNA?RAGE) and subsequently challenged with a TDI?human serum albumin (TDI-HSA) conjugate, and the changes in cellular MUC5AC mRNA expression as detected using RT-PCR; the protein expressions of ERK and p?ERK in the cells were examined with Western blotting. The effect of ERK inhibitor U0126 pretreatment on MUC5AC mRNA expression was also analyzed in the cells.</p><p><b>RESULTS</b>Compared with the control mice, TDI-induced asthmatic mice showed significantly higher rates of PAS positivity and increased MUC5AC and p?ERK expressions in the airway (P<0.05). Treatment with FPS?ZM1 significantly decreased PAS positivity and lowered MUC5AC and p?ERK expressions in the airway of the asthmatic mice (P<0.05). Exposure of 16HBE cells to TDI?HSA caused a significant increase in MUC5AC mRNA expression and p?ERK protein expression (P<0.05), while RAGE knockdown obviously suppressed TDI?HSA-induced upregulation of p-ERK and MUC5AC mRNA (P<0.05). Treatment with the ERK inhibitor U0126 also lowered TDI?HSA?induced up?regulation of MUC5AC mRNA in the cells (P<0.05).</p><p><b>CONCLUSION</b>RAGE signaling induces MUC5AC expression via extracellular signal-regulated kinase pathway to promote mucus overproduction in mice with TDI-induced asthma.</p>

Role of epidermal growth factor receptor in house dust mite-induced airway epithelial barrier dysfunction / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the role of epidermal growth factor receptor (EGFR) signaling pathway in bronchial epithelial actin stress fiber (F-actin) rearrangement induced by house dust mite (HDM).</p><p><b>METHODS</b>Normal human bronchial epithelial cells (16HBE) were stimulated with HDM with or without pretreatment with AG-1478, an EGFR inhibitor. The levels of phospho(p)-EGFR, F-actin, E-cadherin and β-catenin in the cell cultures were detected with Western blotting. The localizations of F-actin, E-cadherin and β-catenin in the bronchial epithelial cells were determined with immunofluorescence assay, and the transmembrane electrical resistance (TER) and FITC-dextran flux (FITC-DX) in the cells were measured to assess the barrier function of the bronchial epithelia.</p><p><b>RESULTS</b>HDM stimulation of the cells for 10 min resulted in significantly increased p-EGFR expression (P<0.05) without causing obvious changes in the expression of E-cadherin (P>0.05) or β-catenin (P>0.05). Immunofluorescence assay revealed delocalization of E-cadherin and β-catenin in HDM-treated 16HBE cells, shown by their diffusion from the cell membrane to the cytoplasm. In HDM-treated cells, the TER was significantly decreased to (70.00∓4.33)% and the FITC-DX was significantly increased to (115.98∓4.34)%; Inhibition of EGFR reversed the delocalization of E-cadherin and β-catenin, improved the TER to (90.00∓3.75)% and lowered the FITC-DX to (101.10∓2.10)%. HDM induced increased expression and rearrangement of F-actin, which was obviously inhibited by pretreatment of the cells with AG-1478 (P<0.05).</p><p><b>CONCLUSION</b>EGFR signaling pathway mediates HDM-induced F-actin rearrangement in human bronchial epithelial cells to contribute to epithelial barrier dysfunction.</p>

Comparison of Talaromyces marneffei Infection in Human Immunodeficiency Virus-positive and Human Immunodeficiency Virus-negative Patients from Fujian, China / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Talaromyces (Penicillium) marneffei (TM) is an emerging dimorphic human pathogenic fungus that is endemic to Southeast Asia. TM mostly occurs as an opportunistic infection in patients with human immunodeficiency virus (HIV). The objective of this study was to compare the clinical and laboratory parameters of patients with TM infections who were HIV-positive and HIV-negative and to assess therapies and outcomes.</p><p><b>METHODS</b>This was a retrospective analysis of 26 patients diagnosed with disseminated TM infection from September 2005 to April 2014 at Fujian Provincial Hospital, China.</p><p><b>RESULTS</b>Patients with TM infection tend to present with fever, weight loss, and anemia. The time from symptom onset to confirmed diagnosis was greater for HIV-negative patients (n = 7; median: 60 days, range: 14-365 days) than for HIV-positive patients (n = 19; median: 30 days, range: 3-90 days, Mann-Whitney U = 31.50, P= 0.041). HIV-negative patients were more likely to have dyspnea (57.1% vs. 5.3%, χ2 = 8.86, P= 0.010), low neutrophil count (Mann-Whitney U = 27.00, P= 0.029), high CD4 count (Mann-Whitney U = 0.00, P= 0.009), and high lymphocyte count (Mann-Whitney U = 21.00, P= 0.009). There were no significant differences in other demographic, clinical, or biochemical characteristics. Among all the patients, 12 HIV-positive patient and 1 HIV-negative patient received amphotericin and fluconazole treatment, 9 of whom improved, 1 died, 2 had kidney damage, 1 had hypokalemia due to exceeded doses.</p><p><b>CONCLUSIONS</b>HIV-negative patients with TM infections tend to have a longer diagnostic interval, a higher percentage of dyspnea, higher levels of CD4 and lymphocytes, and lower neutrophil counts than TM infection in HIV-positive patients. Treatment programs with amphotericin and fluconazole are mostly effective.</p>

High fractional exhaled nitric oxide may predict response to inhaled corticosteroid therapy in patients with subacute cough / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate fractional exhaled nitric oxide (FENO) level in patients with subacute cough and its value in predicting the patients' response to inhaled corticosteroids (ICS) treatment.</p><p><b>METHODS</b>A total of 100 patients with persistent cough lasting more than 3 weeks were enrolled, including 52 patients with subacute cough and 48 with chronic cough. FENO, spirometry, and responses to ICS therapy of the patients were evaluated.</p><p><b>RESULTS</b>The recruited patients had a median (inter-quartile ranges) FENO level of 19 ppb (12-30 ppb). Patients with chronic cough had a significantly higher median FENO level than those with subacute cough (20.5 vs 16 ppb; Z=-2.245, P=0.025). A FENO level ≥25 ppb was recorded in 15 (28.8%) patients with subacute cough, as compared with 20 (41.6%) in patients with chronic cough (χ(2)=1.801, P=0.179). With a FENO ≥25 ppb as the critical value to justify ICS treatment, 15 patients with subacute cough received ICS and 14 (93.3%) of them showed obvious relief of cough after 2 weeks of therapy, a response rate similar to that of 85.0% (17/20) in patients with chronic cough receiving the treatment (χ(2)=0.588, P=0.443). In patients with subacute cough, those with cough variant asthma (CVA) or eosinophilic bronchitis (EB) had a significantly higher median FENO level than those with postinfectious cough [(16 (11-31) ppb vs 11 (8-19) ppb, P<0.01]. In the etiological analysis, CVA or EB was identified in 23 (44.2%) of the patients with subacute cough, as compared 21 (43.8%) in patients with chronic cough (χ(2)=0.002, P=0.961).</p><p><b>CONCLUSION</b>FENO may be an important indicator for etiological diagnosis of subacute cough and for predicting the response to ICS treatment.</p>

Mesenchymal stem cell attenuates neutrophil-predominant inflammation and acute lung injury in an in vivo rat model of ventilator-induced lung injury / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Subsequent neutrophil (polymorphonuclear neutrophil [PMN])-predominant inflammatory response is a predominant feature of ventilator-induced lung injury (VILI), and mesenchymal stem cell (MSC) can improve mice survival model of endotoxin-induced acute lung injury, reduce lung impairs, and enhance the repair of VILI. However, whether MSC could attenuate PMN-predominant inflammatory in the VILI is still unknown. This study aimed to test whether MSC intervention could attenuate the PMN-predominate inflammatory in the mechanical VILI.</p><p><b>METHODS</b>Sprague-Dawley rats were ventilated for 2 hours with large tidal volume (20 mL/kg). MSCs were given before or after ventilation. The inflammatory chemokines and gas exchange were observed and compared dynamically until 4 hours after ventilation, and pulmonary pathological change and activation of PMN were observed and compared 4 hours after ventilation.</p><p><b>RESULTS</b>Mechanical ventilation (MV) caused significant lung injury reflected by increasing in PMN pulmonary sequestration, inflammatory chemokines (tumor necrosis factor-alpha, interleukin-6 and macrophage inflammatory protein 2) in the bronchoalveolar lavage fluid, and injury score of the lung tissue. These changes were accompanied with excessive PMN activation which reflected by increases in PMN elastase activity, production of radical oxygen series. MSC intervention especially pretreatment attenuated subsequent lung injury, systemic inflammation response and PMN pulmonary sequestration and excessive PMN activation initiated by injurious ventilation.</p><p><b>CONCLUSIONS</b>MV causes profound lung injury and PMN-predominate inflammatory responses. The protection effect of MSC in the VILI rat model is related to the suppression of the PMN activation.</p>

Development of microfluidic chip with adjustable concentration and pressure gradient for 3D cell culture / 医用生物力学

Objective To develop a microfluidic device with the adjustable concentration and pressure gradient for 3D cell culture in hydrogel and set up an in vitro model with the capability to closely simulate in vivo microenvironment for cell growth. Methods The microfluidic chip, with a middle channel for 3D cell culture and two side channels for delivering cell culture medium, was designed and fabricated using standard soft lithography and replica molding techniques. Its capability to generate concentration gradient, interstitial flow and image cell in situ was demonstrated. Results A simple microfluidic chip for 3D cell culture in hydrogel with the capability to generate the concentration and pressure gradient was obtained. At a flow rate of 2 μL•min-1 in each side channel, the concentration gradients remained constant after 3 h. The interstitial flow across the gel scaffold was generated by a 100 Pa pressure difference between two-side channels with the pressure gradient of 0.11 Pa/μm. Human adult dermal microvascular endothelial cells (HMVEC) were maintained in 3D culture with collagen type I and observed with confocal microscopy. Conclusions The microfluidic chip is simple and easy to operate and it can simulate the complicated microenvironment in vivo. The chip also allows the multiparameter control of microenvironment, facilitating the better understanding of interaction between cells and microenvironment.

Effect of polyI: C on secretion of thymic stromal lymphopoietin and airway inflammation in mice with respiratory syncytial virus-induced asthma exacerbation / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effects of polyinosinic-polycytidylic acid (polyI:C) on the production of thymic stromal lymphopoietin (TSLP) and airway inflammation in mice with exacerbated asthma induced by respiratory syncytial virus (RSV).</p><p><b>METHODS</b>Thirty-two female BALB/c mice were randomly divided into 4 groups, namely the PBS control group, OVA group, OVA/RSV group, and OVA/RSV/polyI:C group. In the latter 3 groups, the mice were sensitized by OVA and stimulated with nebulized OVA. RSV was inoculated into the nasal cavity of the sensitized mice and polyI:C (1 mg/kg) was intramuscularly administered. The airway response to metacholine was examined, and the serum levels of IL-4, IL-5, IL-13, and IFN-γ and TSLP in the supernatants of bronchoalveolar lavage fluid (BALF) were detected using ELISA. The total BALF cells, eosinophils, lymphocytes and neutrophils were counted. The lung specimens were collected to observe the inflammation with HE staining, and immunohistochemistry was employed to determine TSLP production in the airway epithelial cells.</p><p><b>RESULTS</b>The mice in RSV/OVA/polyI:C group showed a significantly lower airway responsiveness to metacholine than those in OVA/RSV group (P<0.01). Compared with OVA/RSV group, RSV/OVA/polyI:C group showed significantly lower serum levels of IL-4, IL-5, IL-13 and TSLP in BALF (P<0.05), with also lower total BALF cells, eosinophils and lymphocytes (P<0.05) and lessened infiltration of the airway inflammatory cells. Immunohistochemistry of TSLP also demonstrated a lower production of TSLP in the airway epithelial cells in RSV/OVA/polyI:C group than in OVA/RSV group.</p><p><b>CONCLUSIONS</b>polyI:C can inhibit the increase in TSLP production in the airway epithelial cells after RSV infection and relieve airway inflammation in mice with RSV-induced asthma exacerbation.</p>

The generation of the endothelial specific cdc42-deficient mice and the effect of cdc42 deletion on the angiogenesis and embryonic development / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>High microvascular permeability plays an essential role in pathological process of multiple diseases such as septic shock, acute lung injury and acute respiratory distress syndrome, and burns. Inhibiting hyperpermeability is significant for controlling these conditions. Cdc42, as a main member of the small Rho GTPase family, plays a critical role in controlling and regulating the endothelial junctional permeability. We aimed to generate and identify endothelial specific cdc42-deficient mice by the Cre/loxp recombination approach, for examination in an animal model of the contribution of the cdc42 gene in the microvascular barrier function.</p><p><b>METHODS</b>We crossed cdc42(Flox/Flox) mice with mice expressing endothelial cell-specific Cre recombinase, and the offspring with the genotype cdc42(Flox/+)Tie2Cre(+/-) were back-crossed with the cdc42(Flox/Flox) mice. The cdc42(Flox/Flox)Tie2Cre(+/-) mice in the F2 generation were the target mice. If the cdc42 deficient mice did not survive, we would observe the cdc42 deficient mice embryos, and compare them with wild-type mice embryos.</p><p><b>RESULTS</b>Cdc42(flox/+)Cre(+/-) mice were mated with the cdc42(Flox/Flox) mice and among the living offspring there were no cdc42(Flox/Flox)Cre(+/-) target mice. We found the endothelial special cdc42 deficient embryos at the E7.5-E16.5 stage. We observed that cdc42 deficient embryos were much smaller, had fewer vessels and were a little more swollen compared with the wild-type embryos.</p><p><b>CONCLUSIONS</b>Endothelial specific knockout of cdc42 caused embryonic lethality and the mice did not survive to birth. The target embryos were much smaller, had fewer vessels and were a little more swollen compared with the wild-type embryos. These results demonstrated that the cdc42 plays an important role in development of embryos and in development of microvessels as well as microvascular permeability.</p>

25-hydroxyvitamin D3-induced increases of normal human airway epithelial cell permeability is not mediated by upregulated ZO-1 expression / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the effect of 25-hydroxyvitamin D3 on the permeability and ZO-1 expression in normal human airway epithelial cells.</p><p><b>METHODS</b>MTT assay was used to assess the viability of human airway epithelial cell line 16HBE following a 24-hour exposure to different concentrations of 25-hydroxy vitamin D3, and the transepithelial electrical resistance (TER) of the cell monolayer was measured using a Millicell-ERS voltohmmeter. Real-time quantitative RT-PCR was employed to determine the changes of ZO-1 mRNA expression in the cells following the exposures.</p><p><b>RESULTS</b>Exposure to 25-hydroxyvitamin D3 resulted in significantly increased permeability of 16HBE cells, but the exspression of ZO-1 showed no obvious changes. 25-hydroxyvitamin D3 at 4×10(-9) mol/L showed the strongest effect in increasing the permeability of cell monolayer.</p><p><b>CONCLUSION</b>25-hydroxyvitamin D3 increases the permeability of normal bronchial airway epithelial cell monolayer in vitro, but this effect is not mediated by upregulation of ZO-1 expression.</p>

Role of the AdeABC efflux pump in carbapenems resistance of clinical isolates of Acinetobacter baumannii / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the role of AdeABC efflux pump in carbapenems resistance of Acinetobacter baumannii in light of the phenotype and genetype of the efflux pump.</p><p><b>METHODS</b>The phenotype of the efflux pump was detected in 138 clinical isolates of A.baumannii using the efflux pump inhibitor carbonyl cyanide 3-chlorophenylhydrazone (CCCP). The mRNA expression of pump-encoding gene adeB in the strains was detected using quantitative real-time RT-PCR.</p><p><b>RESULTS</b>Of the 138 strains, 28 showed positivities for AdeABC efflux pump identified by Mueller-Hinton Broth with CCCP. Of the 39 strains resistant to meropenem, 15 (38.4%) showed positive results in CCCP assay, a rate significantly higher than that among the 99 sensitive strains (13.1%, 13/99) (X(2)=12.477(b), P=0.01). The mRNA expression of efflux pump-encoding gene adeB was detected by real-time RT-PCR at a level of 0.899∓∓1.172 in meropenem-sensitive strains, significantly lower than the level of 21.101∓∓21.443 in meropenem-resistant strains (t=4.403, P=0.000).</p><p><b>CONCLUSIONS</b>Efflux plays a role in carbapenems resistance in the clinical isolates of A. baumannii. The AdeABC efflux pump may be an important factor in reducing carbapenems sensitivity in A. baumannii.</p>

Investigation of the level of perceived control of asthma and the factors affecting such perception in South China / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the level of the patients perceived control of asthma (PCA) in South China and analyze the risk factors contributing to inadequate PCA.</p><p><b>METHODS</b>A total of 150 asthmatic out-patients consisting of 86 males and 64 females aged 19-65 (38.6∓11.7) years were enrolled in this investigation. The patients were asked to complete questionnaires of the demographic data, perceived control of asthma (PCAQ-6) scales, asthma control test (ACT) scales and Standard asthma-specific quality of life [AQLQ(S)] scale. The data of spirometric measurements, blood cell count and induced sputum cell count were also collected.</p><p><b>RESULTS</b>All the 150 asthmatic out-patients recruited completed the questionnaires and examinations. The PCAQ-6 scores ranged from 10 to 26 (18.75∓3.42) in these patients (18.6∓3.28 in male and 18.95∓3.6 in female patients), significantly lower than those reported in other countries (P<1). PCA was positively correlated to the level of asthma control (r(p)=0.377, P=0.000) and AQLQ(S) scores (r(p)=0.675, P=0.000). Multiple linear regression showed that PCA was positively correlated to FEV1% and blood neutrophil counts, and inversely to asthma duration.</p><p><b>CONCLUSION</b>The level of the PCA appears inadequate in South China. The PCA can affect the level of asthma control and asthma-specific quality of life. The factors contributing to inadequate PCA include primarily asthma duration, lung function and blood neutrophil counts.</p>

Application of flexirigid thoracoscopy in the diagnosis of pleural disease with unknown etiology / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the diagnostic accuracy of flexirigid thoracoscopy for pleural diseases and the patients' compliance.</p><p><b>METHODS</b>Forty-seven patients with pleural effusion and thickening of unknown etiology underwent examinations with flexirigid thoracoscopy with subsequent pathological examination, and the diagnostic accuracy and the patients' compliance were observed.</p><p><b>RESULTS</b>Thoracoscopy identified lesions in the pleural and/or diaphragm in 42 patients and no lesions in 5 patients. Malignancy was confirmed in 21 (44.7%), tuberculosis in 17 (36.2%), idiopathic hypereosinophilic syndrome in 1 (2.1%), nocardiasis in 1 (2.1%), constrictive pericarditis in 1 (2.1%), chronic empyema in 2 (4.3%), splenic artery embolization in 1 (2.1%), and negative result in 3 (6.4%) of the cases. The diagnostic accuracy rate of flexirigid thoracoscopy reached 93.6%, and no serious complications in relation to the examination was found.</p><p><b>CONCLUSION</b>Flexirigid thoracoscopy is efficient and relatively safe for diagnosis of pleural diseases with or without hydrothorax.</p>

Factors affecting the prognosis of invasive pulmonary fungal infections after kidney transplantation: analysis of the ten-year single-center data / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the factors affecting the prognosis of invasive pulmonary fungal infection (IPFI) in patients after kidney transplantation.</p><p><b>METHODS</b>This retrospective study involved 80 concurrent patients with IPFI after receiving kidney transplantation in Zhujiang Hospital from January 1, 2000 to April 1, 2010. Fourteen factors including age, gender, pathogens, body temperature on day 5, renal insufficiency, mechanical ventilation, and clinical pulmonary infection score (CPIS) on day 5 were analyzed by univariate analysis and multivariate Logistic regression analysis to identify the factors related to the prognosis.</p><p><b>RESULTS</b>Univariate analysis showed that a normal body temperature on day 5 of antifungal treatment (P=0.024), fasting high blood glucose (P=0.001), renal insufficiency (P=0.002), malnutrition (P=0.018), time of infection after transplantation (P=0.046), low CPIS on day 5 (P=0.000) and mechanical ventilation (P=0.000) all affected the prognosis of the patients. Logistic regression analysis showed that renal insufficiency (OR=18.096), mechanical ventilation (OR=130.7) and low CPIS on day 5 (OR=0.011) were independent prognostic factors, among which the low CPIS on day 5 was a protective factor.</p><p><b>CONCLUSION</b>Timely and adequate empirical therapy and renal replacement therapy, along with adjusted anti-fungal therapy protocol according to the CPIS score on day 5, may improve the prognosis of IPFI after kidney transplantation.</p>

Localization and expression of Slingshot-1L in peripheral eosinophils from patients with acute asthma exacerbation / 南方医科大学学报

<p><b>OBJECTIVE</b>Eosinophils play a pivotal role in asthmatic airway inflammation. We previously found a significantly high expression of Slingshot-1L (SSH-1L) in peripheral eosinophils in acute exacerbations of asthma. Objective To investigate the expression and localization patterns of SSH-1L in peripheral blood eosinophils of asthmatic patients and their changes after treatment with inhaled corticosteroids.</p><p><b>METHODS</b>We recruited 4 outpatients with acute exacerbations of asthma who received no previous corticosteroid treatment and 1 healthy volunteer. From all the subjects 30 ml peripheral venous blood samples were collected before and after a 3-month treatment with inhaled fluticasone. The eosinophils were isolated, purified and counted, and the expressions of SSH-1L in the eosinophils were examined by RT-PCR and Western blotting. The localization of SSH-1L phosphatases in the peripheral eosinophils was detected by immunofluorescence assay in one patient.</p><p><b>RESULTS</b>SSH-1L phosphatases distributed diffusely in the cytoplasm, especially dense near the membrane of the peripheral eosinophils. Glucocorticoids treatment resulted in a significant reduction in both the SSH-1L mRNA expression (0.7403∓0.1124 vs 0.4101∓0.0363, P=0.001) and SSH-1L protein expression (0.3410∓0.1337 vs 0.1543∓0.0551, P=0.039).</p><p><b>CONCLUSION</b>A high expression of SSH-1L in peripheral eosinophils in acute exacerbations of asthma may play a role in the activation and migration of eosinophils. The efficacy of inhaled corticosteroids in asthma control might be partly attributed to a down-regulated expression of SSH-1L.</p>

The comparison between the vascular endothelial cells special cdc42-deficient heterozygous mice and the non-knockout mice on lung tissue pathological change and vasopermeability in acute lung injury / 南方医科大学学报

<p><b>OBJECTIVE</b>To compare the change of lung tissue and vasopermeability between the vascular endothelial cells special cdc42-deficient heterozygous mice and the non-knockout mice in acute lung injury.</p><p><b>METHODS</b>The mice with vascular endothelial cell-specific expression of cre recombinase were crossed with cdc42(flox/flox) mice. The cdc42(flox/+)Cre(+/-) F1 offspring mice were crossed back with cdc42(flox/flox) mice, resulting in the F2 generation mice with three genotypes, namely cdc42(flox/+)Cre(+/-), cdc42(flox/flox)Cre(-/-) and cdc42(flox/+)Cre(+/-). The heterozygous mice with cdc42(flox/+)Cre(+/-) genotype were selected as the model mice, with the other two genotype groups as the control. After intratracheal instillation of 2 mg/kg LPS to induce acute lung injury, the mice were sacrificed to examine the lung pathologies, lung wet/dry ratio and lung microvascular permeability.</p><p><b>RESULTS</b>The heterozygous mice with cdc42 gene knockout (cdc42(flox/+)Cre(+/-)) showed no significant differences from the two control groups in the lung pathological score, lung wet/dry ratio or the lung microvascular permeability coefficient.</p><p><b>CONCLUSION</b>There were no significant difference on lung tissue and vasopermeability between the vascular endothelial cells special cdc42-deficient heterozygous mice and the non-knockout mice.</p>

Preliminary molecular epidemiology of the Staphylococcus aureus in lower respiratory tract infections: a multicenter study in China / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Staphylococcus aureus (S. aureus) remains as an important microbial pathogen resulting in community and nosocomial acquired infections with significant morbidity and mortality. Few reports for S. aureus in lower respiratory tract infections (LRTIs) have been documented. The aim of this study was to explore the molecular epidemiology of S. aureus in LRTIs in China.</p><p><b>METHODS</b>A multicenter study of the molecular epidemiology of S. aureus in LRTIs was conducted in 21 hospitals in Beijing, Shanghai and twelve other provinces from November 2007 to February 2009. All the collected S. aureus strains were classified as minimum inhibitory concentration (MIC), mecA gene, virulence genes Panton-Valentine Leukocidin (PVL) and γ-hemolysin (hlg), staphylococcal cassette chromosome mec (SCCmec) type, agr type, and Multilocus Sequence Typing (MLST).</p><p><b>RESULTS</b>Totally, nine methicillin-sensitive S. aureus (MSSA) and 29 methicillin-resistant S. aureus (MRSA) strains were isolated after culture from a total of 2829 sputums or bronchoalveolar lavages. The majority of MRSA strains (22/29) had a MIC value of ≥ 512 µg/ml for cefoxitin. The mecA gene acting as the conservative gene was carried by all MRSA strains. PVL genes were detected in only one S. aureus strain (2.63%, 1/38). The hlg gene was detected in almost the all S. aureus (100% in MSSA and 96.56% in MRSA strains). About 75.86% of MRSA strains carried SCCmec III. Agr type 1 was predominant (78.95%) among the identified three agr types (agr types 1, 2, and 3). Totally, ten sequence type (ST) of S. aureus strains were detected. A new sequence type (ST1445) was found besides confirming ST239 as the major sequence type (60.53%). A dendrogram generated from our own MLST database showed all the bootstrap values ≤ 50%.</p><p><b>CONCLUSION</b>Our preliminary epidemiology data show SCCmec III, ST239 and agr type 1 of S. aureus as the predominant strains in LRTIs in Mainland of China.</p>

Effect of toluene diisocyanate on reactive oxygen species production and permeability of human bronchial epithelial cells in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of toluene diisocyanate (TDI) on the production of reactive oxygen species (ROS) and the permeability of human bronchial epithelial (HBE) cells.</p><p><b>METHODS</b>TDI-human serum albumin (TDI-HSA) conjugate was prepared using a modified Son's method. MTT assay was used to assess HBE cell viability after exposure to different concentrations of TDI-HSA. The level of intracellular ROS of HBE cells was detected by flow cytometry with an oxidation-sensitive fluorescent probe 2',7'-dichlorofluorescein diacetate (DCFH-DA) uploading, and the permeability of cell monolayer was assessed by detecting the transepithelial electrical resistance (TEER).</p><p><b>RESULTS</b>The exposure to 120 µg/ml TDI-HSA did not obviously affect the cell viability. Compared with the control group, the intracellular fluorescent intensity increased significantly in the cells exposed to 20, 60, and 100 µg/ml TDI-HSA (P<0.05). The intracellular ROS production increased significantly after 100 µg/ml TDI-HSA treatment (P<0.05), but the increment in ROS production was significantly suppressed by pretreatment of the cells with N-acetylcysteine (NAC) (P<0.05), which also enhanced the TEER decreased by TDI-HSA treatment (P<0.05).</p><p><b>CONCLUSIONS</b>TDI enhances the permeability of HBE cell monolayer partially through a ROS-mediated pathway, suggesting the importance of oxidative stress in TDI-induced pulmonary diseases.</p>

Effects of different factors on the expression of thymic stromal lymphopoietin in respiratory syncytial virus-infected human airway epithelial cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effects of different factors on the expressions of thymic stromal lymphopoietin (TSLP) in respiratory syncytial virus (RSV)-infected human airway epithelial cell line 16HBE cells.</p><p><b>METHODS</b>RSV amplified by infecting Hep-2 cells was identified for its virulence. 16HBE cells were divided into six groups, namely the control group, RSV group, RSV/anti-TLR3 group, RSV/IFN-gamma group, RSV/IL-4 group and RSV/dexamethasone group with corresponding treatments. Real-time RT-PCR was used to examine the expression of TSLP mRNA in the cells 6 h after RSV infection. Western blotting was used to examine TSLP protein expression in the cells 24 h after the infection.</p><p><b>RESULTS</b>The expression of TSLP mRNA in 16HBE cells 6 h after RSV infection increased by 1.63-/+0.08 folds as compared to the expression level in the control cells. The expression of TSLP mRNA was significantly decreased in RSV-infected cells treated with anti-TLR3 antibody (P=0.034) and recombinant human IFN-gamma (P<0.001), but increased with the treatment by recombinant human IL-4 (P=0.025). Dexamethasone significantly inhibited the expression of TSLP mRNA in RSV-infected cells (P<0.001). The production of TSLP protein in 16HBE cells increased by 1.9 folds (P<0.001) 24 h after RSV infection, but underwent no significant changes after treatment with anti-TLR3 antibody (P=0.114). Recombinant human IFN-gamma significantly decreased while IL-4 enhanced the expression of TSLP protein in the infected cells (P=0.020 and 0.014, respectively). Dexamethasone significantly inhibited the increment of TSLP protein expression in RSV-infected cells (P<0.001).</p><p><b>CONCLUSIONS</b>RSV infection can enhance the expressions of TSLP in human airway epithelial cells. IFN-gamma, anti-TLR3 and dexamethasone can inhibit the elevation of TSLP expression induced by RSV infection, but IL-4 synergistically enhances its expression.</p>

Respiratory syncytial virus increases the expression and release of high mobility group Box-1 protein in the lung tissue of mice / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the expression and release of high mobility group Box-1 protein (HMGB1) in the lung tissue of mice with respiratory syncytial virus (RSV) infection.</p><p><b>METHODS</b>Eighteen mice were randomized into PBS control group, RSV group and RSV/ribavirin group. Seven days after RSV infection in the mice in the latter two groups, the bronchoalveolar lavage fluid (BALF) was collected for cell counting and classification, and the levels of IL-4, IFN-gamma and HMGB1 in the supernatants of the BALF were detected. The left lungs of the mice were harvested for pathological examination with HE staining, and the right lungs were taken for detecting the expression of HMGB1 by Western blotting.</p><p><b>RESULTS</b>RSV induced a TH1 inflammation in the lung tissue as shown by significantly increased IFN-gamma and decreased IL-4 levels in the BALF. The total BALF cells, neutrophils and macrophages in the RSV group were significantly higher than those in the control group (P<0.05), and the cell counts were significantly decreased by ribavirin treatment (P<0.05). HE staining showed neutrophil and lymphocyte infiltration in the lumen and submucous layer of the airway in RSV group. The level of HMGB1 in the BALF significantly increased in the RSV group as compared with that in the control group (P<0.05), but was lowered by ribavirin treatment (P<0.05). The expression of the HMGB1 in the lung tissue significantly increased in the RSV group in comparison with that in the control group (P<0.05), and was not significantly decreased by ribavirin treatment (P>0.05).</p><p><b>CONCLUSIONS</b>The increased expression and release of HMGB1 in the lung tissue of mice with RSV infection is probably involved in the development of RSV infection-related lung diseases.</p>