Cuicui Chen

Mesenchymal stem cell-based angiopoietin-1 gene therapy for acute lung injury induced by lipopolysaccharide in mice.

Bone marrow‐derived mesenchymal stem cells (MSCs) can serve as a vehicle for gene therapy. Angiopoietin‐1 (Ang1) is a critical factor for endothelial survival and vascular stabilization via the inhibition of endothelial permeability and leukocyte–endothelium interactions. We hypothesized that MSC‐based Ang1 gene therapy might be a potential therapeutic approach for lipopolysaccharide (LPS)‐induced lung injury. MSCs were isolated from 6 week‐old inbred male mice and transduced with the Ang1 gene, using a lentivirus vector. The MSCs showed no significant phenotypic changes after transduction. In the in vivo mouse model, the LPS‐induced lung injury was markedly alleviated in the group treated with MSCs carrying Ang1 (MSCs–Ang1), compared with groups treated with MSCs or Ang1 alone. The expression of Ang1 protein in the recipient lungs was increased after MSCs–Ang1 administration. The histopathological and biochemical indices of LPS‐induced lung injury were improved after MSCs‐based Ang1 gene treatment. MSCs–Ang1 administration also reduced pulmonary vascular endothelial permeability and the recruitment of inflammatory cells into the lung. Cells of MSC origin could be detected in the recipient lungs for 2 weeks after injection with MSCs. These results suggest that MSCs and Ang1 have a synergistic role in the treatment of LPS‐induced lung injury. MSC‐based Ang1 gene therapy may be developed as a potential novel strategy for the treatment of acute lung injury. Copyright

Integrin αvβ5 as a biomarker for the assessment of non-small cell lung cancer metastasis and overall survival

There is growing interest in how integrins play a role in cancer disease biology and what applications these may have in anti‐cancer therapeutic development. This study investigates integrin αvβ5 expression in non‐small cell lung carcinoma (NSCLC) and its correlations with clinical information.

Urban particulate matter triggers lung inflammation via the ROSMAPK- NF-κB signaling pathway

Background Particulate matter (PM) is a high risk factor for various respiratory diseases and triggers an inflammatory response in lung tissues. However, the molecular mechanism of the PM-induced inflammatory response is incompletely understood. Methods Human bronchial epithelial cells (HBECs) were treated with the urban PM 1649b for assessment of the inflammatory response. The intracellular level of reactive oxygen species (ROS) was measured by flow cytometry. PM-activated signaling pathways were addressed with specific inhibitors. In vivo, the C57 mice model of PM-induced acute lung inflammation was established with intratracheal instillation of PM for 2 consecutive days. The oxidant stress in lung tissues was assessed with dihydroethidium (DHE) staining, and malondialdehyde (MDA) activity and hydrogen peroxide (H2O2) assays. The histopathologic changes in lung tissues and number of inflammatory cells in bronchoalveolar lavage fluid (BALF) were examined. Expression of pro-inflammatory cytokines in BALF was measured by ELISA. Results PM increased the expression of interleukin (IL)-1β, IL-6, IL-8, matrix metalloproteinase (MMP)-9 and cyclooxygenase (COX)-2 in a dose-dependent manner. ROS generation and activation of MAPK (ERK, JNK, p38 MAPK) and NF-κB pathways were detected in PM-exposed HBECs. Pretreatment with N-acetylcysteine (NAC) led to the inflammatory response, ROS level and activation of the MAPK and NF-κB pathways to be attenuated. Blockade of ERK, JNK or p38 MAPK pathway with specific inhibitor prevented the release of pro-inflammatory cytokines and activation of the NF-κB pathway. Inhibition of the NF-κB pathway reduced the expression of pro-inflammatory cytokines. In vivo, PM exposure increased oxidant stress in lung tissues, infiltration of inflammatory cells around PM in lung tissues, the number of total cells and inflammatory cells in BALF, and the concentrations of IL-1β, IL-6, IL-8 and MMP-9 in BALF, all of which were reversed partially upon NAC treatment. Conclusions PM exposure enhanced the airway inflammatory response significantly through ROS-mediated activation of MAPK (ERK, JNK, p38 MAPK) and downstream NF-κB signaling pathways. Oxidative stress appeared to be the key regulator for PM-induced lung inflammation. These results suggested the molecular mechanism of lung inflammation caused by PM.

Immune Repertoire Diversity Correlated with Mortality in Avian Influenza A (H7N9) Virus Infected Patients

Specific changes in immune repertoires at genetic level responding to the lethal H7N9 virus are still poorly understood. We performed deep sequencing on the T and B cells from patients recently infected with H7N9 to explore the correlation between clinical outcomes and immune repertoire alterations. T and B cell repertoires display highly dynamic yet distinct clonotype alterations. During infection, T cell beta chain repertoire continues to contract while the diversity of immunoglobulin heavy chain repertoire recovers. Patient recovery is correlated to the diversity of T cell and B cell repertoires in different ways – higher B cell diversity and lower T cell diversity are found in survivors. The sequences clonally related to known antibodies with binding affinity to H7 hemagglutinin could be identified from survivors. These findings suggest that utilizing deep sequencing may improve prognostication during influenza infection and could help in development of antibody discovery methodologies for the treatment of virus infection.

Multiple gene mutations identified in patients infected with influenza A (H7N9) virus

Influenza A (H7N9) virus induced high mortality since 2013. It is important to elucidate the potential genetic variations that contribute to virus infection susceptibilities. In order to identify genetic mutations that might increase host susceptibility to infection, we performed exon sequencing and validated the SNPS by Sanger sequencing on 18 H7N9 patients. Blood samples were collected from 18 confirmed H7N9 patients. The genomic DNA was captured with the Agilent SureSelect Human All Exon kit, sequenced on the Illumina Hiseq 2000, and the resulting data processed and annotated with Genome analysis Tool. SNPs were verified by independent Sanger sequencing. The DAVID database and the DAPPLE database were used to do bioinformatics analysis. Through exon sequencing and Sanger sequencing, we identified 21 genes that were highly associated with H7N9 influenza infection. Protein-protein interaction analysis showed that direct interactions among genetic products were significantly higher than expected (p = 0.004), and DAVID analysis confirmed the defense-related functions of these genes. Gene mutation profiles of survived and non-survived patients were similar, suggesting some of genes identified in this study may be associated with H7N9 influenza susceptibility. Host specific genetic determinants of disease severity identified by this approach may provide new targets for the treatment of H7N9 influenza.

Emphysema is an independent risk factor for 5‐year mortality in patients with bronchiectasis

Bronchiectasis is a common disabling respiratory disease in China. However, the literatures that focused on the long‐term prognosis and the risk factors for mortality are limited.

The Mechanism of MSCs Therapy in Acute Respiratory Distress Syndrome

In past decades, acute respiratory distress syndrome (ARDS) has been associated with high mortality and morbidity. Although many maneuvers have been tested including tens of clinical trials, so far there is still no approved pharmacological intervention available for ARDS except protective ventilation strategy. Mesenchymal stem cells (MSCs) has shown improved survival in various ARDS animal model after administration. Here we summarized the updates of MSC derivation and purification, administration approaches, timing of MSC delivery, and mechanism of MSC therapy in order to provide a state-of-art paradigm of cell based therapy in ARDS and to facilitate the development of MSC therapy in ARDS patients.

Urban particulate matter (PM) suppresses airway antibacterial defence

BackgroundEpidemiological studies have shown that urban particulate matter (PM) increases the risk of respiratory infection. However, the underlying mechanisms are poorly understood. PM has been postulated to suppress the activation of airway epithelial innate defence in response to infection.MethodsThe effects of PM on antibacterial defence were studied using an in vitro infection model. The levels of antimicrobial peptides were measured using RT-PCR and ELISA. In addition to performing colony-forming unit counts and flow cytometry, confocal microscopy was performed to directly observe bacterial invasion upon PM exposure.ResultsWe found that PM PM increased bacterial invasion by impairing the induction of β-defensin-2 (hBD-2), but not the other antimicrobial peptides (APMs) secreted by airway epithelium. PM further increases bacteria-induced ROS production, which is accompanied by an accelerated cell senescence and a decrease in bacteria-induced hBD-2 production, and the antioxidant NAC treatment attenuates these effects. The PM exposure further upregulated the expression of IL-8 but downregulated the expression of IL-13 upon infection.ConclusionsPM promotes bacterial invasion of airway epithelial cells by attenuating the induction of hBD-2 via an oxidative burst. These findings associate PM with an increased susceptibility to infection. These findings provide insight into the underlying mechanisms regarding the pathogenesis of particulate matter.

Amphiregulin potentiates airway inflammation and mucus hypersecretion induced by urban particulate matter via the EGFR-PI3Kα-AKT/ERK pathway

Ambient particulate matter (PM) promotes the development and exacerbation of chronic respiratory diseases, including chronic obstructive pulmonary disease (COPD) and asthma, by increasing inflammation and mucus hypersecretion. However, the biological mechanisms underlying PM-induced airway inflammation and mucus hypersecretion remain unclear. Amphiregulin (AREG) is an important ligand for epidermal growth factor receptor (EGFR) and participates in the regulation of several biological functions. Here, the PM-exposed human bronchial epithelial cell (HBEC) model was used to define the role of AREG in PM-induced inflammation and mucus hypersecretion and its related signaling pathways. The expression of AREG was significantly increased in a dose-dependent manner in HBECs subjected to PM exposure. Moreover, PM could induce inflammation and mucus hypersecretion by upregulating the expression of IL-1α, IL-1β, and Muc-5ac in HBECs. The EGFR, AKT, and ERK signaling pathways were also activated in a time- and dose-dependent manner. The AREG siRNA markedly attenuated PM-induced inflammation and mucus hypersecretion, and activation of the EGFR-AKT/ERK pathway. Exogenous AREG significantly increased the expression of IL-1α, IL-1β, and Muc-5ac, and induced activation of the EGFR-AKT/ERK pathway in HBECs. Further, under PM exposure, exogenous AREG significantly potentiated PM-induced inflammation and mucus hypersecretion, and activation of the EGFR-AKT/ERK pathway. Tumor-necrosis factor-alpha converting enzyme (TACE) and EGFR specific inhibitor pretreatment showed that AREG was secreted by TACE-mediated cleavage to regulate PM-induced inflammation and mucus hypersecretion by binding to the EGFR. Moreover, according to the inhibitory effect of specific inhibitors of the class I PI3K isoforms, AKT and ERK, PM-induced inflammation and mucus hypersecretion was regulated by PI3Kα activation and its downstream AKT and ERK pathways. This study strongly suggests the adverse effect of AREG in PM-induced inflammation and mucus hypersecretion via the EGFR-PI3Kα-AKT/ERK pathway. These findings contribute to a better understanding of the biological mechanisms underlying exacerbation of chronic respiratory diseases induced by PM exposure.

Recovery from acute lung injury can be regulated via modulation of regulatory T cells and Th17 cells

Acute lung injury (ALI) is a severe inflammatory disease, for which no specific treatment exists. The decreased ratio of regulatory T cells (CD4+CD25+FoxP3 Tregs) and Th17 cells is implicated in ALI and inflammation. We here investigated whether maintaining the balance of CD4+CD25+Foxp3+Tregs and Th17 cells can alleviate lung injury. For CD4+CD25+FoxP3 Treg depletion, 200 μg of an anti‐CD25 antibody was administered intraperitoneally per mouse on days −3 and −1 before lipopolysaccharide (LPS) instillation. And 150 μg of TGF‐β was administered intraperitoneally per mouse on day 0 after LPS instillation. To down‐regulate of Th17 cells, 200 μg per mouse of isotype, IL‐17 or IL‐22 antibodies were injected intraperitoneally into mice at days 0 after LPS instillation. We detected lung morphology; lung wet‐to‐dry weight ratio; protein concentration, the count of total cells, neutrophils and macrophages, and cytokines in bronchoalveolar lavage fluid (BALF). And we also evaluated the percentage of CD4+CD25+Foxp3+Tregs in lung, and Th17 cells in lung. CD4+CD25+Foxp3+Tregs depletion via anti‐CD25 treatment or TGF‐β neutralization delayed recovery of ALI. The prolonged inflammation was mainly dominated by neutrophils, macrophages and Th17 cells. Furthermore, inhibition of Th17 cells via monoclonal antibodies against IL‐17 and IL‐22 alleviated ALI inflammation by inhibiting the recruitment of neutrophils and macrophages, increasing the number of CD4+CD25+Foxp3+Tregs. Our findings support a critical role for CD4+CD25+Foxp3+Tregs in regulating from ALI pathophysiology, and a potential therapeutic role for the inhibition of Th17 cells in ALI treatment. These findings provide a rationale for treating patients with ALI by modulating CD4+CD25+Foxp3+Tregs and Th17 cells.