Defining the inflammatory signature of human lung explant tissue in the presence and absence of glucocorticoid

Background: Airway inflammation is a feature of many respiratory diseases and there is a need for newer, more effective anti-inflammatory compounds. The aim of this study was to develop an ex vivo human lung explant model which can be used to help study the mechanisms underlying inflammatory responses and which can provide a tool to aid drug discovery for inflammatory respiratory diseases such as asthma and COPD. Method: Parenchymal lung tissue from 6 individual donors was dissected and cultured with two pro-inflammatory stimuli, lipopolysaccharide (LPS) (1 µg/ml) and interleukin-1 beta (IL-1β) (10 ng/ml) in the presence or absence of dexamethasone (1 µM). Inflammatory responses were assessed using Luminex analysis of tissue culture supernatants to measure levels of 21 chemokines, growth factors and cytokines. Results: A robust and reproducible inflammatory signal was detected across all donors for 12 of the analytes measured following LPS stimulation with a modest fold increase (4-fold in CCL3, CCL4, GM-CSF, IL-10, TNF-α and IL-1β. The inflammatory signal induced by IL-1β stimulation was less than that observed with LPS but resulted in elevated levels of 7 analytes (CXCL8, CCL3, CCL4, GM-CSF, IL-6, IL-10 and TNF-α). The inflammatory responses induced by both stimulations was supressed by dexamethasone for the majority of analytes. Conclusions: These data provide proof of concept that this ex vivo human lung explant model is responsive to inflammatory signals and could be used to investigate the anti-inflammatory effects of existing and novel compounds. In addition this model could be used to help define the mechanisms and pathways involved in development of inflammatory airway disease

Chloride intracellular channel 1 (CLIC1) contributes to modulation of cyclic AMP-activated whole cell chloride currents in human bronchial epithelial cells

Chloride channels are known to play critical physiological roles in many cell types. Here we describe the expression of anion channels using RNA Seq in primary cultures of human Bronchial Epithelial Cells (hBECs). Chloride intracellular channel (CLIC) family members were the most abundant chloride channel transcripts, and CLIC1 showed the highest level of expression. In addition, we characterise the chloride currents in hBECs and determine how inhibition of CLIC1 via pharmacological and molecular approaches impacts these. We demonstrate that CLIC1 is able to modulate cyclic AMP-induced chloride currents and suggest that CLIC1 modulation could be important for chloride homeostasis in this cell type

The Ser82 RAGE variant affects lung function and serum RAGE in smokers and sRAGE production in vitro

Introduction: Genome-Wide Association Studies have identified associations between lung function measures and Chronic Obstructive Pulmonary Disease (COPD) and chromosome region 6p21 containing the gene for the Advanced Glycation End Product Receptor (AGER, encoding RAGE). We aimed to (i) characterise RAGE expression in the lung, (ii) identify AGER transcripts, (iii) ascertain if SNP rs2070600 (Gly82Ser C/T) is associated with lung function and serum sRAGE levels and (iv) identify whether the Gly82Ser variant is functionally important in altering sRAGE levels in an airway epithelial cell model. Methods: Immunohistochemistry was used to identify RAGE protein expression in 26 human tissues and qPCR was used to quantify AGER mRNA in lung cells. Gene expression array data was used to identify AGER expression during lung development in 38 fetal lung samples. RNA-Seq was used to identify AGER transcripts in lung cells. sRAGE levels were assessed in cells and patient serum by ELISA. BEAS2B-R1 cells were transfected to overexpress RAGE protein with either the Gly82 or Ser82 variant and sRAGE levels identified. Results: Immunohistochemical assessment of 6 adult lung samples identified high RAGE expression in the alveoli of healthy adults and individuals with COPD. AGER/RAGE expression increased across developmental stages in human fetal lung at both the mRNA (38 samples) and protein levels (20 samples). Extensive AGER splicing was identified. The rs2070600T (Ser82) allele is associated with higher FEV1, FEV1/FVC and lower serum sRAGE levels in UK smokers. Using an airway epithelium model overexpressing the Gly82 or Ser82 variants we found that HMGB1 activation of the RAGE-Ser82 receptor results in lower sRAGE production. Conclusions: This study provides new information regarding the expression profile and potential role of RAGE in the human lung and shows a functional role of the Gly82Ser variant. These findings advance our understanding of the potential mechanisms underlying COPD particularly for carriers of this AGER polymorphism

Dataset for: CHLORIDE INTRACELLULAR CHANNEL 1 (CLIC1) CONTRIBUTES TO MODULATION OF CYCLIC AMP-ACTIVATED WHOLE CELL CHLORIDE CURRENTS IN HUMAN BRONCHIAL EPITHELIAL CELLS

Chloride channels are known to play critical physiological roles in many cell types. Here we describe the expression of anion channels using RNA Seq in primary cultures of human Bronchial Epithelial Cells (hBECs). Chloride intracellular channel (CLIC) family members were the most abundant chloride channel transcripts, and CLIC1 showed the highest level of expression. In addition, we characterise the chloride currents in hBECs and determine how inhibition of CLIC1 via pharmacological and molecular approaches impacts these. We demonstrate that CLIC1 is able to modulate cyclic AMP-induced chloride currents and suggest that CLIC1 modulation could be important for chloride homeostasis in this cell type

Baseline characteristics of UK smoker population used for genetic association studies.

<p>Baseline characteristics of UK smoker population used for genetic association studies.</p

<i>AGER</i> isoform expression in three HBEC donors using RNA Seq.

<p>Structure and abundance of known <i>AGER</i> isoforms in three human bronchial epithelial cell donors illustrating heterogeneity in expression levels. Percentage abundances (% FPKM) were calculated for each donor. Transcripts for full length and soluble <i>AGER</i> were identified at similar low abundancies. FPKM; fragments per kilobase of transcript per million mapped reads.</p

Immunohistochemical analysis of RAGE expression in healthy and COPD lung.

<p>In healthy lung tissue, RAGE was found to be localised to the cytoplasm and membrane. RAGE expression was high in the pneumocytes of alveolar regions (a). The bronchial epithelium showed variable weak to moderate staining (e). In lung tissue of individuals with COPD, RAGE was very strongly immunopositive in the membrane and cytoplasm of the pneumocytes in the alveolar regions (b). The bronchial epithelium from individuals with COPD was weak or immunonegative for the RAGE protein (f). All isotype controls were negative (c, d, g and h). Representative images of one healthy and one COPD lung shown. x10 magnification.</p

Gene expression array data of 38 fetal lungs for the <i>AGER</i> probes.

<p>Expression intensities for the <i>AGER</i> probes 210081_at and 217046_s_at were plotted against the gestational age of each fetal lung sample and showed an increase in expression with fetal lung age. RMA; Robust Multi-array Average. Affymetrix U133 Plus 2 expression array probe 210081_at probes for exon 8 of AGER mRNA whilst 217046_s_at probes AGER exons 7–11’.</p

Fetal lung gene array data for <i>AGER</i> expression across Pseudoglandular and Canalicular stages.

<p>Fetal lung gene array data for <i>AGER</i> expression across Pseudoglandular and Canalicular stages.</p

<i>AGER</i> mRNA expression levels in total lung and airway cells.

<p>Q-PCR analysis identified <i>AGER</i> mRNA was highly expressed in total lung and at lower levels in human airway smooth muscle cells (HASM) cells, human bronchial epithelial cells (HBEC) and the BEAS-2BR1 bronchial epithelial cell line, (n = 3).</p