HIV1+ smokers develop emphysema at an earlier age and with a higher incidence than HIV1- smokers. Based on the knowledge that human alveolar macrophages (AM) are capable of producing proteases that degrade extracellular matrix components, we hypothesized that upregulation of AM matrix metalloproteinases may be associated with the emphysema of HIV1+ smokers. To test this hypothesis, microarray analysis was used to screen which MMP genes were expressed by AM isolated by bronchoalveolar lavage (BAL) of HIV1+ smokers with early emphysema. For each of the MMP genes observed to be expressed (MMP-1, -2, -7, -9, -10, -12 and -14), TaqMan PCR was used to quantify the relative expression in AM from 4 groups of individuals: HIV1 healthy nonsmokers, HIV1- healthy smokers, HIV1- smokers with early emphysema and HIV1+ smokers with early emphysema. Strikingly, while AM gene expression of MMPs was higher in HIV1- individuals with emphysema in comparison with HIV1- healthy smokers, for the majority of the MMPs (-1, -7, -9, -10, -12), AM expression from HIV1+ smokers with early emphysema was significantly higher than HIV1- smokers with early emphysema. Consistent with these observations, HIV1+ individuals with early emphysema had higher levels of epithelial lining fluid MMPs (-2, -7, -9,-12) than the 3 HIV1 groups. Interestingly, the active forms of MMP-2, -9 and -12 were detected in epithelial lining fluid from HIV1+ individuals with early emphysema, but not in any of the other groups. Considering that the substrate specificity of the upregulated AM MMPs includes collagenases, gelatinases, matrilysins and elastase, these data suggest that upregulated AM MMP genes and activation of MMP proteins may contribute to the emphysema of HIV1+ individuals who smoke.
Up-regulation of alveolar macrophage matrix metalloproteinases in HIV1(+) smokers with early emphysema.
Sex, Age
View SamplesLectins are proteins present on cell surfaces or as shed extracellular proteins that function in innate immune defense as phagocytic receptors to recognize specific bacterial cell wall components. Based on the knowledge that cigarette smoking is associated with increased risk of bacterial infection, we hypothesized that cigarette smoking may modulate the expression of lectin genes in the airway epithelium. Affymetrix HG U133 Plus 2.0 microarrays were used to survey expression of lectin genes in large (3rd to 4th order bronchi) airway epithelium from 9 normal nonsmokers and 20 phenotypic normal smokers and small (10th to 12th order bronchi) airway epithelium from 13 normal nonsmokers and 20 phenotypic normal smokers. From the 72 lectin genes that were surveyed, there were no changes (>2-fold change, p<0.05) in gene expression in either large or small airway epithelium among normal smokers compared to nonsmokers except for a striking down regulation in both large and small airway epithelium of normal smokers of intelectin 1, a recently described lectin that participates in the innate immune response by recognizing and binding to galactofuranosyl residues in the cell walls of bacteria (large airway epithelium, p<0.003; small airway epithelium, p<0.002). TaqMan RT-PCR confirmed the observation that intelectin 1 was down-regulated in both large (p<0.05) and small airway epithelium (p<0.02) of normal smokers compared to normal nonsmokers. Immunohistochemistry assessment of biopsies of the large airway epithelium of normal nonsmokers demonstrated intelectin 1 was expressed in secretory cells, with qualitatively decreased expression in biopsies from normal smokers. Western analysis confirmed the decreased expression of intelectin 1 in airway epithelium of normal smokers compared to normal nonsmokers (p<0.02). Finally, compared to normal nonsmokers, intelectin 1 expression was decreased in small airway epithelium of smokers with early COPD (n= 13, p<0.001) and smokers with established COPD (n= 14, p<0.001), in a fashion similar to that of normal smokers. In the context that intelectin 1 is an epithelial molecule that likely plays a role in defense against bacteria, the down regulation of expression of intelectin 1 in response to cigarette smoking may contribute to the increase in susceptibility to infections observed in smokers, including those with COPD.
Decreased expression of intelectin 1 in the human airway epithelium of smokers compared to nonsmokers.
Sex, Age
View SamplesAirway basal cells (BC) function as progenitor cells capable of differentiating into ciliated and secretory cells to replenish the airway epithelium during physiological turnover and repair. The objective of this study was to define the role of Notch signaling in regulating human airway BC differentiation into a pseudostratified mucociliated epithelium. Notch inhibition with -secretase inhibitors demonstrated Notch activation is essential for BC differentiation into secre-tory cells and ciliated cells, but more so for the secretory lineage. Sustained Notch activation via lentivirus expression of the intracellular domain of each Notch receptor (NICD1-4) demonstrated that the Notch 2 and 4 pathways have little effect on BC differentiation, while activation of the Notch1 or 3 pathways has a major influence, with persistent expression of NICD1 or 3 resulting in a skewing toward secretory cell differentiation with a parallel decrease in ciliated cell differentiation. These observations provide insights into the control of the balance of BC differentiation into the secretory vs ciliated cell lineage, a balance that is critical for maintaining the normal function of the airway epithelium in barrier defense against the inhaled environment.
Activation of NOTCH1 or NOTCH3 signaling skews human airway basal cell differentiation toward a secretory pathway.
Specimen part, Time
View SamplesBackground: The first step in SARS-CoV-2 infection is binding of the virus to angiotensin converting enzyme 2 (ACE2) on the airway epithelium. Asthma affects over 300 million people world-wide, many of whom may encounter SARS-CoV-2. Epidemiologic data suggests that asthmatics who get infected may be at increased risk of more severe disease. Our objective was to assess whether maintenance inhaled corticosteroids (ICS), a major treatment for asthma, is associated with airway ACE2 expression in asthmatics.
Up-regulation of ACE2, the SARS-CoV-2 receptor, in asthmatics on maintenance inhaled corticosteroids.
Specimen part, Treatment
View SamplesDysfunction of the cystic fibrosis transmembrane regulator (CFTR) in cystic fibrosis (CF) results in exaggerated and chronic inflammation as well as increased susceptibility to chronic pulmonary infections, in particular with Pseudomonas aeruginosa. Based on the concept that host immune responses do not seem to be adequate to eradicate P.aeruginosa from the lungs of CF patients and that dendritic cells (DC) play an important role in initiating and shaping adaptive immune responses, this study analyzed the role of CFTR in bone marrow-derived murine DC from CFTR knockout (CF) mice with and without exposure to P.aeruginosa. DC expressed CFTR mRNA and protein, although at much lower levels compared to whole lung. Microarray analysis of gene expression levels in DC generated from CF and wild type (WT) mice revealed significantly different expression of 16 genes in CF DC compared to WT DC. Among the genes with lower expression in CF DC was Caveolin-1, a membrane lipid raft protein. Messenger RNA and protein levels of Caveolin-1 were decreased in the CF DC compared to WT DC. Consistently, the active form of sterol-responsive element binding protein (SREBP), a negative regulator of Caveolin-1 expression, was increased in CF DC. Following exposure to P.aeruginosa, gene expression levels in CF and WT DC changed for 912 genes involved in inflammation, chemotaxis, signaling, cell cycling and apoptosis more than 1.5-fold. Among the genes that showed a different response between WT and CF DC infected with P.aeruginosa, were 3-hydroxysterol-7 reductase (Dhcr7) and stearoyl-CoA desaturase 2 (Scd2), two enzymes involved in the lipid metabolism that are also regulated by SREBP. These results suggest that CFTR dysfunction in non-epithelial cells results in changes in the expression of genes encoding factors involved in membrane structure and lipid-metabolism. These membrane alterations in immune cells may contribute to the abnormal inflammatory and immune response characteristic of CF.
Influence of the cystic fibrosis transmembrane conductance regulator on expression of lipid metabolism-related genes in dendritic cells.
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View SamplesHuman airway epithelial cells cultured in vitro at air-liquid interface (ALI) form a pseudostratified epithelium that forms tight junctions and cilia, and produces mucin, and are widely used as a model of differentiation, injury, and repair. To assess how closely the transcriptome of ALI epithelium matches that of in vivo airway epithelial cells, we used microarrays to compare the transcriptome of human large airway epithelial cells cultured at ALI with the transcriptome of large airway epithelium obtained via bronchoscopy and brushing. Gene expression profiling showed global gene expression correlated well between ALI cells and brushed cells, but there were some differences. Gene expression patterns mirrored differences in proportions of cell types (ALI have higher percentages of basal cells, brushed cells have higher percentages of ciliated cells), with ALI cells expressing higher levels of basal cell-related genes and brushed cells expressing higher levels of cilia-related genes. Pathway analysis showed ALI cells had increased expression of cell cycle and proliferation genes, while brushed cells had increased expression of cytoskeletal organization and humoral immune response genes. Overall, ALI cells are a good representation of the in vivo airway epithelial transcriptome, but for some biologic questions, the differences in the in vitro vs in vivo environments need to be considered.
Do airway epithelium air-liquid cultures represent the in vivo airway epithelium transcriptome?
Sex, Age
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Up-regulation of expression of the ubiquitin carboxyl-terminal hydrolase L1 gene in human airway epithelium of cigarette smokers.
Sex, Age, Race
View SamplesDisparate Oxidant-related Gene Expression of Human Small Airway Epithelium Compared to Autologous Alveolar Macrophages in Response to the In Vivo Oxidant Stress of Cigarette Smoking
Disparate oxidant gene expression of airway epithelium compared to alveolar macrophages in smokers.
Sex, Age
View SamplesBackground: Whereas cilia damage and reduced cilia beat frequency have been implicated as causative of reduced mucociliary clearance in smokers, theoretically mucociliary clearance could also be affected by cilia length. Based on models of mucociliary clearance predicting cilia length must exceed the 6 -7 m airway surface fluid depth to generate force in the mucus layer, we hypothesized cilia height may be decreased in airway epithelium of normal smokers compared to nonsmokers.
Smoking is associated with shortened airway cilia.
Sex, Age
View SamplesUpregulation of Expression of the Ubiquitin Carboxyl Terminal Hydrolase L1 Gene in Human Airway Epithelium of Cigarette Smokers
Up-regulation of expression of the ubiquitin carboxyl-terminal hydrolase L1 gene in human airway epithelium of cigarette smokers.
Sex, Age
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