Panax notoginseng saponin R1 improves glucocorticoid-inhibited airway epithelium repair via glucocorticoid receptor ß.

BACKGROUND: Panax notoginseng saponin R1(PNS-R1), derived from Panax notoginseng roots, promotes wound repair, whereas glucocorticoids can inhibit the repair of airway epithelial damage in asthma. OBJECTIVE: This study investigated whether PNS-R1 counteracts the inhibitory effects of glucocorticoids on the repair of airway epithelial damage in asthma. METHODS: In vivo, female C57BL/6 mice were sensitized, challenged with house dust mites (HDM), and treated with dexamethasone, PNS-R1, and/or adenovirus GRß-shRNA. Airway epithelium damage was examined using pathological sections of the trachea and bronchi, markers of airway inflammation, epithelial cells in bronchoalveolar lavage fluid, and expression of the E-cadherin protein. In vitro, we treated 16HBE cells with dexamethasone, PNS-R1, and/or GRß-siRNA and detected cell proliferation and migration. The expression of GRß and key components of MKP-1 and Erk1/2 were detected by western blotting. RESULTS: In vivo, PNS-R1 reduced airway inflammation, hyperresponsiveness, and mucus hypersecretion; the combination of PNS-R1 and dexamethasone promoted airway epithelial integrity and reduced cell detachment. In vitro, PNS-R1 alleviated the inhibition of bronchial epithelial cell growth, migration, and proliferation by dexamethasone; PNS-R1 promoted GRß expression, inhibited MKP-1 protein expression, and activated MAPK signaling, thereby promoting airway epithelial cell proliferation and repair. CONCLUSIONS: Panax notoginseng saponin R1 alleviated the inhibitory effect of dexamethasone on the repair of airway epithelial damage in asthmatic mice, likely by promoting the proliferation of airway epithelial cells by stimulating GRß expression and activating the MAPK pathway.

Epidemiological characteristics of respiratory viruses in hospitalized children during the COVID-19 pandemic in southwestern China.

Background: Multinational studies have reported that the implementation of nonpharmaceutical interventions (NPIs) to control severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission coincided with the decline of other respiratory viruses, such as influenza viruses and respiratory syncytial virus. Objective: To investigate the prevalence of common respiratory viruses during the coronavirus disease 2019 (COVID-19) pandemic. Methods: Respiratory specimens of children with lower respiratory tract infections (LRTIs) hospitalized at the Children's Hospital of Chongqing Medical University from January 1, 2018 to December 31, 2021 were collected. Seven common pathogens, including respiratory syncytial virus (RSV), adenovirus (ADV), influenza virus A and B (Flu A, Flu B), and parainfluenza virus types 1-3 (PIV1-3), were detected by a multiplex direct immunofluorescence assay (DFA). Demographic data and laboratory test results were analyzed. Results: 1) A total of 31,113 children with LRTIs were enrolled, including 8141 in 2018, 8681 in 2019, 6252 in 2020, and 8059 in 2021.The overall detection rates decreased in 2020 and 2021 (P < 0.001). The detection rates of RSV, ADV, Flu A, PIV-1, and PIV-3 decreased when NPIs were active from February to August 2020, with Flu A decreasing most predominantly, from 2.7% to 0.3% (P < 0.05). The detection rates of RSV and PIV-1 resurged and even surpassed the historical level of 2018-2019, while Flu A continued decreasing when NPIs were lifted (P < 0.05). 2) Seasonal patterns of Flu A completely disappeared in 2020 and 2021. The Flu B epidemic was observed until October 2021 after a long period of low detection in 2020. RSV decreased sharply after January 2020 and stayed in a nearly dormant state during the next seven months. Nevertheless, the detection rates of RSV were abnormally higher than 10% in the summer of 2021. PIV-3 decreased significantly after the COVID-19 pandemic; however, it atypically surged from August to November 2020. Conclusion: The NPIs implemented during the COVID-19 pandemic affected the prevalence and seasonal patterns of certain viruses such as RSV, PIV-3, and influenza viruses. We recommend continuous surveillance of the epidemiological and evolutionary dynamics of multiple respiratory pathogens, especially when NPIs are no longer necessary.

Global research status and trends of bronchiectasis in children from 2003 to 2022: A 20-year bibliometric analysis.

Background: This study aims to analyze the research hotspots, evolution, and developing trends in pediatric bronchiectasis over the past 20 years using bibliometric analysis and visualization tools to identify potential new research directions. Methods: Publications related to bronchiectasis in children were retrieved from the Web of Science Core Collection (WoSCC) database from 2003 to 2022. Knowledge maps were performed through VOSviewer1.6.18 and CiteSpace6.1 R2. Results: A total of 2,133 publications were searched, while only 1,351 original articles written in English between 2003 and 2022 were incorporated. After removing duplicates, we finally included 1,350 articles published by 6,593 authors from 1,865 institutions in 80 countries/regions in 384 different academic journals with an average citation frequency of 24.91 times. The number of publications shows an extremely obvious binomial growth trend. The majority of publications originated from the United States, Australia, and England. The institutes in Australia, especially Charles Darwin University, published the most articles associated with pediatric bronchiectasis. In addition, Pediatric Pulmonology was the most published journal. In terms of authors, Chang AB was the most productive author, while Gangell CL had the highest average citation frequency. The five keywords that have appeared most frequently during the last two decades were "children," "cystic fibrosis," "bronchiectasis," "ct," and "pulmonary-function." According to keyword analysis, early diagnosis and intervention and optimal long-term pediatric-specific management were the most concerned topics for researchers. Conclusion: This bibliometric analysis indicates that bronchiectasis in children has drawn increasing attention in the last two decades as its recognition continues to rise, providing scholars in the field with significant information on current topical issues and research frontiers.

Microvesicles Derived from Human Umbilical Cord Mesenchymal Stem Cells Enhance Alveolar Type II Cell Proliferation and Attenuate Lung Inflammation in a Rat Model of Bronchopulmonary Dysplasia.

Although it is known that exosomes derived from human umbilical cord mesenchymal stem cells (hUCMSCs) alleviate hyperoxic lung injury of bronchopulmonary dysplasia (BPD) in animal models, the role of microvesicles (MVs) derived from hUCMSCs in BPD is poorly defined. Furthermore, antenatal inflammation has been linked to high risk of BPD in preterm infants. The purpose of this study was to explore whether MVs derived from hUCMSCs can preserve lung structure and function in an antenatal lipopolysaccharide- (LPS-) induced BPD rat model and to clarify the underlying mechanism. We demonstrate that antenatal LPS induced alveolar simplification, altered lung function, and dysregulated pulmonary vasculature, which restored by hUCMSCs and MVs treatment. Furthermore, MVs were large vesicles with a diameter of 100-900 nanometers and mostly uptaken by alveolar epithelial type II cells (AT2) and macrophages. Compared with the LPS-exposed group, MVs restored the AT2 cell number and SP-C expression in vivo and promoted the proliferation of AT2 cells in vitro. MVs also restored the level of IL-6 and IL-10 in lung homogenate. Additionally, PTEN/AKT and MAPK pathways were associated with the protection of MVs. Taken together, this study suggests MVs derived from hUCMSCs improve lung architecture and function in an antenatal LPS-induced BPD rat model by promoting AT2 cell proliferation and attenuating lung inflammation; thus, MVs provide a promising therapeutic vehicle for BPD treatment.

Clinical Analysis of Primary Tracheobronchial Tumors in Children and Evaluation of the Predicting Models for Mucoepidermoid Carcinoma.

OBJECTIVE: To determine the clinical characteristics and prognosis of primary tracheobronchial tumors (PTTs) in children, and to explore the most common tumor identification methods. METHODS: The medical records of children with PTTs who were hospitalized at the Children's Hospital of Chongqing Medical University from January 1995 to January 2020 were reviewed retrospectively. The clinical features, imaging, treatments, and outcomes of these patients were statistically analyzed. Machine learning techniques such as Gaussian naïve Bayes, support vector machine (SVM) and decision tree models were used to identify mucoepidermoid carcinoma (ME). RESULTS: A total of 16 children were hospitalized with PTTs during the study period. This included 5 (31.3%) children with ME, 3 (18.8%) children with inflammatory myofibroblastic tumors (IMT), 2 children (12.5%) with sarcomas, 2 (12.5%) children with papillomatosis and 1 child (6.3%) each with carcinoid carcinoma, adenoid cystic carcinoma (ACC), hemangioma, and schwannoma, respectively. ME was the most common tumor type and amongst the 3 ME recognition methods, the SVM model showed the best performance. The main clinical symptoms of PPTs were cough (81.3%), breathlessness (50%), wheezing (43.8%), progressive dyspnea (37.5%), hemoptysis (37.5%), and fever (25%). Of the 16 patients, 7 were treated with surgery, 8 underwent bronchoscopic tumor resection, and 1 child died. Of the 11 other children, 3 experienced recurrence, and the last 8 remained disease-free. No deaths were observed during the follow-up period. CONCLUSION: PTT are very rare in children and the highest percentage of cases is due to ME. The SVM model was highly accurate in identifying ME. Chest CT and bronchoscopy can effectively diagnose PTTs. Surgery and bronchoscopic intervention can both achieve good clinical results and the prognosis of the 11 children that were followed up was good.

Reassessing the role of tracheobronchomalacia in persistent wheezing.

BACKGROUND: Tracheobronchomalacia (TBM) is often manifested as wheezing. Reassessing the role of TBM in persistent wheezing in children is essential. METHODS: We selected children who were diagnosed with TBM by bronchoscopy and who underwent bronchoscopic reexamination for persistent wheezing or chronic cough between January 2009 and July 2019. The clinical and bronchoscopy data were collected and retrospectively reviewed. For statistical analysis, we used the Kaplan-Meier method, Kruskal-Wallis test, and Fisher exact test. RESULTS: A total of 79 patients (57 males and 22 females) were included. The median age of the first TBM diagnosis was 7 (interquartile [IQR] 4-11) months. The median age of the first wheezing episode was 4 (IQR 3-7) months. During the time interval between the two bronchoscopies, malacia lesions resolved in 50 patients (63.3%), improvement was seen in 14 patients (17.7%), no change was observed in 11 patients (13.9%), and the condition was aggravated in 4 patients (5.1%). The malacia lesions in 37 patients resolved before 2 years of age. Among the 50 resolved patients, 22 patients (44.0%) reported wheezing three times or more between bronchoscopy evaluations, and 13 of these 22 patients (59.1%) with atopy or family history of allergic diseases were ultimately diagnosed with bronchial asthma. CONCLUSIONS: In children with persistent wheezing, the role of TBM should be reassessed, especially in those with atopy or family history of allergic diseases, and bronchial asthma should be considered early.

Blockade of GITRL/GITR signaling pathway attenuates house dust mite-induced allergic asthma in mice through inhibition of MAPKs and NF-κB signaling.

GITRL/GITR signaling pathway plays an important role in allergy, inflammation, transplantation and autoimmunity. However, its role in asthma remains unclear. Thus, the present study aimed to investigate changes in this pathway and observe the therapeutic effect of its blocking on asthma. By using house dust mite-induced asthma model, changes of GITRL/GITR and its downstream molecules MAPKs (e.g., p38 MAPK, JNK and Erk) and NF-κB were observed. After that, GITRL in lung of mice was knocked down by recombinant adeno-associated virus to observe the impact on its downstream molecules and assess the therapeutic effect on asthma. These results showed that GITRL/GITR and its downstream molecules MAPKs/NF-κB were activated in asthmatic mice. This activation was suppressed after GITRL knockdown, and allergic airway inflammation and airway hyperresponsiveness were alleviated. These results demonstrate that GITRL/GITR-MAPKs/NF-κB signaling pathway participates in the pathogenesis of asthma. Blockade of GITRL/GITR signaling pathway exhibits protective effects in a mouse model of house dust mite-induced allergic asthma.

GITRL on dendritic cells aggravates house dust mite-induced airway inflammation and airway hyperresponsiveness by modulating CD4+ T cell differentiation.

BACKGROUND: Glucocorticoid-induced tumor necrosis factor receptor family-related protein ligand (GITRL) plays an important role in tumors, autoimmunity and inflammation. However, GITRL is not known to modulate the pathogenesis of allergic asthma. In this study, we investigated whether regulating GITRL expressed on dendritic cells (DCs) can prevent asthma and to elucidate its mechanism of action. METHODS: In vivo, the role of GITRL in modulating house dust mite (HDM)-induced asthma was assessed in adeno-associated virus (AAV)-shGITRL mice. In vitro, the role of GITRL expression by DCs was evaluated in LV-shGITRL bone marrow dendritic cells (BMDCs) under HDM stimulation. And the direct effect of GITRL was observed by stimulating splenocytes with GITRL protein. The effect of regulating GITRL on CD4+ T cell differentiation was detected. Further, GITRL mRNA in the peripheral blood of asthmatic children was tested. RESULTS: GITRL was significantly increased in HDM-challenged mice. In GITRL knockdown mice, allergen-induced airway inflammation, serum total IgE levels and airway hyperresponsiveness (AHR) were reduced. In vitro, GITRL expression on BMDCs was increased after HDM stimulation. Further, knocking down GITRL on DCs partially restored the balance of Th1/Th2 and Th17/Treg cells. Moreover, GITRL stimulation in vitro inhibited Treg cell differentiation and promoted Th2 and Th17 cell differentiation. Similarly, GITRL mRNA expression was increased in the peripheral blood from asthmatic children. CONCLUSIONS: This study identified a novel role for GITRL expressed by DCs as a positive regulator of CD4+ T cells responses in asthma, which implicates that GITRL inhibitors may be a potential immunotherapy for asthma.

Low-Dose LPS Induces Tolerogenic Treg Skewing in Asthma.

The mechanism(s) underlying endotoxin tolerance in asthma remain elusive. As the endotoxin lipopolysaccharide (LPS) affects the expression of the regulatory T-cell (Treg)-suppressive glucocorticoid-induced tumor necrosis factor receptor ligand (GITRL) on antigen-presenting dendritic cells (DCs), we hypothesized that LPS-induced changes in DC GITRL expression may impact Treg-mediated T-helper (Th) cell suppression and the induction of endotoxin tolerance. Here, we propose a novel mechanism by which low-dose LPS inhalation in neonatal mice induces endotoxin tolerance, thereby offering protection from later asthma development. Three-day old wild-type and Toll-like receptor 4 (TLR4)-deficient neonatal mice were exposed to low-dose LPS (1 µg) intranasally for 10 consecutive days prior to ovalbumin (OVA)-induced asthma to better understand the tolerogenic mechanism(s) of low-dose LPS pre-exposure. In vivo findings were validated using in vitro co-culturing studies of primary CD11c+ DCs and CD4+ T-cells with or without low-dose LPS pre-exposure before OVA stimulation. Low-dose LPS pre-exposure upregulated the Treg response and downregulated pathogenic Th2 and Th17 responses through promoting apoptosis of Th2 and Th17 cells. Low-dose LPS pre-exposure downregulated DC GITRL expression and T-cell GITR expression. Artificial DC GITRL expression abrogated the tolerogenic Treg-skewing effect of low-dose LPS pre-exposure. Low-dose LPS pre-exposure inhibited TRIF/IRF3/IFNß signaling and upregulated expression of tolerogenic TRIF/IRF3/IFNß negative regulators in a TLR4-dependent manner. This tolerogenic DC GITRL downregulation was attributable to TRIF/IRF3/IFNß signaling inhibition. Low-dose LPS pre-exposure produces tolerogenic Treg skewing in neonatal asthmatic mice, a phenomenon attributable to TLR4-dependent TRIF/IRF3/IFNß-mediated DC GITRL downregulation.

Human Umbilical Cord Mesenchymal Stem Cell-Derived Small Extracellular Vesicles Alleviate Lung Injury in Rat Model of Bronchopulmonary Dysplasia by Affecting Cell Survival and Angiogenesis.

Bronchopulmonary dysplasia (BPD) is a serious chronic lung disease in premature newborns, with high morbidity and mortality rates. Mesenchymal stem cell (MSC) transplantation has developed into a promising approach to alleviate BPD. Small extracellular vesicles, which are an important therapeutic component of MSCs, have been reported to be effective in a mouse model of BPD. However, the affected cell types and detailed underlying mechanisms are unclear. In this study, we found that human umbilical cord mesenchymal stem cell-derived small extracellular vesicles (hucMSC-sEVs) were successfully absorbed by lung tissue after intratracheal administration, and remained in the lungs for at least 72 h. The results showed that hucMSC-sEVs restored alveolar structure and lung function, and ameliorated pulmonary hypertension in a rat model of BPD. The number of Ki-67-positive lung cells were improved, while the number of TUNEL-positive lung cells were reduced in our hucMSC-sEV-treated BPD model. Additionally, SP-C staining (a marker of type II alveolar epithelial cells, TIIAECs) and CD31 staining (a marker of pulmonary vascular endothelial cells, PVECs) were both increased in a hyperoxia-induced BPD model treated with hucMSC-sEVs. In vitro, under hyperoxic conditions, the tube-like structure formation was improved in human umbilical vein endothelial cells, and the proliferation was increased and the apoptosis was attenuated in MLE-12 cells treated with hucMSC-sEVs. Furthermore, we observed downregulated expression of PTEN and cleaved-caspase3, and upregulated expression of p-Akt and vascular endothelial growth factor-A in our hucMSC-sEV-treated BPD model. In conclusion, hucMSC-sEVs improved alveolarization and angiogenesis in a rat BPD model by protecting TIIAECs and PVECs, which were associated with the PTEN/Akt signaling pathway.

Panax notoginseng saponin R1 modulates TNF-α/NF-κB signaling and attenuates allergic airway inflammation in asthma.

BACKGROUD: Panax notoginseng saponin R1 (PNS-R1) is one of the most important chemical monomers derived from the panax notoginseng, and our previous study found that PNS-R1 reduced glucocorticoid-induced apoptosis in asthmatic airway epithelial cells. Thus, in this study, we explored the effects of the PNS-R1 on inflammation of allergic asthma. METHODS: The asthmatic mice were administered 15 mg/kg PNS-R1 by intraperitoneal injection three days before sensitized to OVA. The effects of PNS-R1 on asthmatic mice were detected by airway hyperresponsiveness, inflammation, mucus hypersecretion and inflammatory cytokines such as interleukin (IL)-13, IL-4, IL-5, IL-8 and tumor necrosis factor (TNF)-α were studied. We also treated human bronchial epithelial cells (16HBE) with house dust mites (HDM) and then detected the secretion of cellular inflammatory factors (IL-13 and TNF-α). Western blot and immunofluorescence were used to examine the effect of PNS-R1 on TNF-α/NF-κB pathway. TNF-α/NF-κB/IKK signal pathway activator was used in PNS-R1-treated asthmatic mice. RESULTS: PNS-R1 significantly reduced the airway inflammatory, mucus secretion and hyperresponsiveness in asthma model. It also reduced the levels of IL-13, IL-4, IL-5 and IL-8 in bronchoalveolar lavage fluid (BALF) and IgE and OVA-specific IgE in serum for asthma mice. PNS-R1 reduced IL-13 and TNF-α secretion in HDM-treated 16HBE cells. In addition, PNS-R1 suppressed TNF-α/NF-κB pathway in both asthmatic mice and 16HBE. Activation of NF-kB pathway reversed the therapeutic effect of PNS-R1 on asthmatic mice. CONCLUSION: The results indicated that PNS-R1 effectively suppresses allergic airway inflammation of asthma partly through TNF-α/NF-κB pathway. PNS-R1 may play a potential role in allergic asthma treatment in the future.

Allogeneic human umbilical cord-derived mesenchymal stem cells for severe bronchopulmonary dysplasia in children: study protocol for a randomized controlled trial (MSC-BPD trial).

BACKGROUND: Bronchopulmonary dysplasia (BPD) is a complex lung pathological lesion secondary to multiple factors and one of the most common chronic lung diseases. It has a poor prognosis, especially in preterm infants. However, effective therapies for this disease are lacking. Stem-cell therapy is a promising way to improve lung injury and abnormal alveolarization, and the human umbilical cord (hUC) is a good source of mesenchymal stem cells (MSCs), which have demonstrated efficacy in other diseases. We hypothesized that intravenously administered allogeneic hUC-MSCs are safe and effective for severe BPD. METHODS: The MSC-BPD trial is a randomized, single-center, open-label, dose-escalation, phase-II trial designed to investigate the safety and efficacy of hUC-MSCs in children with severe BPD. In this study, 72 patients will be enrolled and randomly divided into two intervention groups and one control group. Patients in the intervention groups will receive a low dose of hUC-MSCs (n = 24; 2.5 million cells/kg) or a high dose of hUC-MSCs (n = 24; 5 million cells/kg) in combination with traditional supportive treatments for BPD. The patients in the control group (n = 24) will be treated with traditional supportive treatments alone without hUC-MSCs. The primary outcome measures will be cumulative duration of oxygen therapy. Follow-up assessments will be performed at 1, 3, 6, 12, and 24 months post intervention, and the key outcome during follow-up will be changes on chest radiography. Statistical analyses will evaluate the efficacy of the hUC-MSC treatment. DISCUSSION: This will be the first randomized controlled trial to evaluate the safety and efficacy of intravenously administered hUC-MSCs in children with severe BPD. Its results should provide a new evidence-based therapy for severe BPD. TRIAL REGISTRATION: ClinicalTrials.gov, ID: NCT03601416. Registered on 26 July 2018.

Enhanced pause correlates with airway neutrophils and airway-epithelial injury in asthmatic mice treated with dexamethasone.

OBJECTIVE: To investigate the correlations among airway inflammation, airway epithelial injury and airway hyperresponsiveness (AHR) in asthmatic mice treated with dexamethasone. METHODS: Female BALB/c mice were sensitized with intraperitoneal and hypodermic injections of ovalbumin (OVA) and aluminum on days 0, 7 and 14, challenged with OVA starting on day 21 for 10 days, and treated with dexamethasone via intraperitoneal injection starting on day 28 for 3 days. Female C57BL/6 mice were treated intranasally with house dust mite (HDM) on days 1 and 14, challenged intranasally with HDM on days 21, 23, 25, 27 and 29, and treated with sivelestat (a selective neutrophil elastase inhibitor) via intraperitoneal injection after each challenge. Following the final challenge, enhanced pause (Penh) and differential cell counts in the broncho-alveolar lavage fluid were measured and the correlations were analyzed. RESULTS: Compared with OVA-challenged BALB/c mice, the counterpart mice treated with dexamethasone showed reduced Penh and shedding of airway epithelial cells. In addition, we found that Penh 50 (an indicator of AHR) had positive correlations with airway neutrophils and shedding of airway epithelial cells, but no correlation with eosinophils, lymphocytes or macrophages. Moreover, shedding of airway epithelial cells had positive correlations with airway neutrophils, but no correlation with eosinophils, lymphocytes or macrophages. Further, sivelestat decreased Penh 50 and shed airway-epithelial cells in HDM-challenged C57BL/6 mice. CONCLUSIONS: Collectively, our findings suggest that airway neutrophils and excessive shedding of airway epithelial cells, but not eosinophils, lymphocytes or macrophages, may be involved in AHR in asthmatic mice treated with dexamethasone.

Human umbilical cord-derived mesenchymal stem cells protect from hyperoxic lung injury by ameliorating aberrant elastin remodeling in the lung of O2-exposed newborn rat.

The incidence and mortality rates of bronchopulmonary dysplasia (BPD) remain very high. Therefore, novel therapies are imminently needed to improve the outcome of this disease. Human umbilical cord-derived mesenchymal stem cells (UC-MSCs) show promising therapeutic effects on oxygen-induced model of BPD. In our experiment, UC-MSCs were intratracheally delivered into the newborn rats exposed to hyperoxia, a well-established BPD model. This study demonstrated that UC-MSCs reduce elastin expression stimulated by 90% O2 in human lung fibroblasts-a (HLF-a), and inhibit HLF-a transdifferentiation into myofibroblasts. In addition, the therapeutic effects of UC-MSCs in neonatal rats with BPD, UC-MSCs could inhibit lung elastase activity and reduce aberrant elastin expression and deposition in the lung of BPD rats. Overall, this study suggested that UC-MSCs could ameliorate aberrant elastin expression in the lung of hyperoxia-induced BPD model which may be associated with suppressing increased TGFß1 activation.

KIF3A knockdown sensitizes bronchial epithelia to apoptosis and aggravates airway inflammation in asthma.

BACKGROUND: KIF3A expression was decreased in asthmatic child patients and animal. Impaired KIF3A expression resulted in increased Th2 inflammation in mice and apoptosis in renal tubular epithelium and photoreceptor cells. This work aimed to investigate the role of KIF3A in epithelium apoptosis and bronchial inflammation in asthma. METHODS: After establishment of ovalbumin induced asthma, the mice were infected with KIF3A adenovirus through nasal cavity inhalation. KIF3A expression and apoptosis in epithelia of nasal mucosa and bronchia were determined using qRT-PCR, western blotting, immunohistochemistry and TUNEL staining. The mRNA expression of COX-2, IL-4, IL-5, IL-13, IL-6, IL-10 and TNF-α was also measured. In vitro, human bronchial epithelial cell line 16HBE 14o- was stimulated with IL-4, IL-13 and TNF-α, accompanied by KIF3A knockdown or overexpression using siRNA or KIF3A adenovirus respectively. Apoptosis, mRNA expression of CCL17, CCL26, IL-5 and IL-8, and protein expression of COX-2 and ß-catenin were determined using flow cytometry, qRT-PCR and western blotting. RESULTS: KIF3A expression was reduced in epithelia of nasal mucosa and bronchia of asthmatic mice, and overexpression of KIF3A ameliorated epithelial cell apoptosis and bronchial inflammation in asthmatic mice. In vitro, KIF3A knockdown significantly promoted epithelium apoptosis, facilitated the transcription of CCL17, CCL26, IL-5 and IL-8, and increased the protein levels of COX-2 and ß-catenin translocation, whereas overexpression of KIF3A exhibited the opposite effect. CONCLUSION: KIF3A plays an important role in epithelium apoptosis and bronchial inflammation in asthma, and may be a potential target for asthma treatment.

Structural basis of respiratory syncytial virus subtype-dependent neutralization by an antibody targeting the fusion glycoprotein.

A licensed vaccine for respiratory syncytial virus (RSV) is unavailable, and passive prophylaxis with the antibody palivizumab is restricted to high-risk infants. Recently isolated antibodies 5C4 and D25 are substantially more potent than palivizumab, and a derivative of D25 is in clinical trials. Here we show that unlike D25, 5C4 preferentially neutralizes subtype A viruses. The crystal structure of 5C4 bound to the RSV fusion (F) protein reveals that the overall binding mode of 5C4 is similar to that of D25, but their angles of approach are substantially different. Mutagenesis and virological studies demonstrate that RSV F residue 201 is largely responsible for the subtype specificity of 5C4. These results improve our understanding of subtype-specific immunity and the neutralization breadth requirements of next-generation antibodies, and thereby contribute to the design of broadly protective RSV vaccines.

Recurrent Wheezing and Cough Caused by Double Aortic Arch, Not Asthma.

INTRODUCTION: Double aortic arch is a congenital vascular abnormality in which the connected segments and their branches course between and compress the trachea and esophagus, often resulting in invariable airway compression. CASE PRESENTATION: A 4-year-old boy with a history of recurrent wheezing was admitted to our hospital for evaluation of asthma based on his past medical history, persistent cough, wheezing, and airway hyperresponsiveness by lung function test. Double aortic arch was diagnosed with computed tomography angiogram. After surgery, the respiratory infection improved strikingly. Early diagnosis and treatment may prevent chronic, irreversible complications. CONCLUSION: We present a case of double aortic arch masquerading as asthma.

Therapeutic Effects of Human Umbilical Cord-Derived Mesenchymal Stem Cells in Acute Lung Injury Mice.

The incidence and mortality of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) are still very high, but stem cells show some promise for its treatment. Here we found that intratracheal administration of human umbilical cord-mesenchymal stem cells (UC-MSCs) significantly improved survival and attenuated the lung inflammation in lipopolysaccharide (LPS)-induced ALI mice. We also used the proteins-chip and bioinformatics to analyze interactions between UC-MSCs treatment and immune-response alternations of ALI mice. Then we demonstrated that UC-MSCs could inhibit the inflammatory response of mouse macrophage in ALI mice, as well as enhance its IL-10 expression. We provide data to support the concept that the therapeutic capacity of UC-MSCs for ALI was primarily through paracrine secretion, particularly of prostaglandin-E2 (PGE2). Furthermore, we showed that UC-MSCs might secrete a panel of factors including GM-CSF, IL-6 and IL-13 to ameliorate ALI. Our study suggested that UC-MSCs could protect LPS-induced ALI model by immune regulation and paracrine factors, indicating that UC-MSCs should be a promising strategy for ALI/ARDS.

The genetic variability of glycoproteins among respiratory syncytial virus subtype A in China between 2009 and 2013.

Human respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory tract infections in infants and children under 5years of age. The novel genotype ON1 has a 72-nucleotide duplication, which is the largest duplicated genome portion of RSV. Whether the ON1 genotype will follow the pattern of the BA genotype, which has a 60-nucleotide duplication, and become the predominant RSV-A strain is a global concern. To obtain information regarding the prevalence of the ON1 genotype in Chongqing in Southwestern China, we examined the circulation pattern of RSV-A identified over four consecutive years (June 2009 to August 2013). In this study, 312 (12%) RSV-A strains were isolated from 2601 nasopharyngeal aspirates, and partial G gene was sequenced successfully in 250 isolates. Of the sequenced Chongqing RSV-A isolates, 237 (94.8%) strains were the NA1 genotype, 4 (1.6%) strains were the NA3 genotype, 4 (1.6%) strains were the NA4 genotype, 1 (0.4%) strain was the GA1 genotype, and 4 (1.6%) strains were identified as the ON1 genotype. Analysis of the distribution, phylogeny, and evolution of the ON1 strains that were collected globally until December 2013 revealed that the ON1 genotype has rapidly disseminated across the world under positive selection pressures. Future studies will determine whether this new genotype will continue to spread and become the dominant strain of RSV-A worldwide. These findings may contribute to the understanding of RSV evolution and to the potential development of a vaccine against RSV.

Detection of respiratory syncytial virus fusion protein variants between 2009 and 2012 in China.

Respiratory syncytial virus (RSV) causes respiratory tract infection, particularly acute lower respiratory tract infection (ALRTI), in early childhood. The RSV fusion protein (F protein) is an important surface protein, and it is the target of both cytotoxic T lymphocytes (CTL) and neutralizing antibodies; thus, it may be useful as a candidate for vaccine research. This study investigated the genetic diversity of the RSV F protein. To this end, a total of 1800 nasopharyngeal aspirates from hospitalized children with ALRTI were collected for virus isolation between June 2009 and March 2012. There were 333 RSV-positive cases (277 cases of RSV A, 55 of RSV B, and 1 with both RSV A and RSV B), accounting for 18.5 % of the total cases. Next, 130 clinical strains (107 of RSV A, 23 of RSV B) were selected for F gene sequencing. Phylogenetic analysis revealed that the F gene sequence is highly conserved, with significant amino acid changes at residues 16, 25, 45, 102, 122, 124, 209, and 447. Mutations in human histocompatibility leukocyte antigen (HLA)-restricted CTL epitopes were also observed. Variations in RSV A F protein at the palivizumab binding site 276 (N→S) increased between 2009 and 2012 and became predominant. Western blot analysis and microneutralization data showed a substitution at residue 276 (N→S) in RSV A that did not cause resistance to palivizumab. In conclusion, the RSV F gene is geographically and temporally conserved, but limited genetic variations were still observed. These data could be helpful for the development of vaccines against RSV infection.