Cigarette Smoke Enhances the Expression of Profibrotic Molecules in Alveolar Epithelial Cells.

Idiopathic pulmonary fibrosis (IPF) is a progressive and lethal disease of unknown etiology. A growing body of evidence indicates that it may result from an aberrant activation of alveolar epithelium, which induces the expansion of the fibroblast population, their differentiation to myofibroblasts and the excessive accumulation of extracellular matrix. The mechanisms that activate the alveolar epithelium are unknown, but several studies indicate that smoking is the main environmental risk factor for the development of IPF. In this study we explored the effect of cigarette smoke on the gene expression profile and signaling pathways in alveolar epithelial cells. Lung epithelial cell line from human (A549), was exposed to cigarette smoke extract (CSE) for 1, 3, and 5 weeks at 1, 5 and 10% and gene expression was evaluated by complete transcriptome microarrays. Signaling networks were analyzed with the Ingenuity Pathway Analysis software. At 5 weeks of exposure, alveolar epithelial cells acquired a fibroblast-like phenotype. At this time, gene expression profile revealed a significant increase of more than 1000 genes and deregulation of canonical signaling pathways such as TGF-β and Wnt. Several profibrotic genes involved in EMT were over-expressed, and incomplete EMT was observed in these cells, and corroborated in mouse (MLE-12) and rat (RLE-6TN) epithelial cells. The secretion of activated TGF-β1 increased in cells exposed to cigarette smoke, which decreased when the integrin alpha v gene was silenced. These findings suggest that the exposure of alveolar epithelial cells to CSE induces the expression and release of a variety of profibrotic genes, and the activation of TGF-β1, which may explain at least partially, the increased risk of developing IPF in smokers

Phosphatidylethanolamine Induces an Antifibrotic Phenotype in Normal Human Lung Fibroblasts and Ameliorates Bleomycin-Induced Lung Fibrosis in Mice

Lung surfactant is a complex mixture of phospholipids and specific proteins but its role in the pathogenesis of interstitial lung diseases is not established. Herein, we analyzed the effects of three representative phospholipid components, that is, dipalmitoilphosphatidylcoline (DPPC), phosphatidylglycerol (PG) and phosphatidylethanolamine (PE), on collagen expression, apoptosis and Ca2+ signaling in normal human lung fibroblasts (NHLF) and probed their effect in an experimental model of lung fibrosis. Collagen expression was measured with RT-PCR, apoptosis was measured by using either the APOPercentage assay kit (Biocolor Ltd., Northern Ireland, UK) or the Caspase-Glo 3/7 assay (Promega, Madison, WI, USA) and Ca2+ signaling by conventional epifluorescence imaging. The effect in vivo was tested in bleomycin-induced lung fibrosis in mice. DPPC and PG did not affect collagen expression, which was downregulated by PE. Furthermore, PE promoted apoptosis and induced a dose-dependent Ca2+ signal. PE-induced Ca2+ signal and apoptosis were both blocked by phospholipase C, endoplasmic reticulum pump and store-operated Ca2+ entry inhibition. PE-induced decrease in collagen expression was attenuated by blocking phospholipase C. Finally, surfactant enriched with PE and PE itself attenuated bleomycin-induced lung fibrosis and decreased the soluble collagen concentration in mice lungs. This study demonstrates that PE strongly contributes to the surfactant-induced inhibition of collagen expression in NHLF through a Ca2+ signal and that early administration of Beractant enriched with PE diminishes lung fibrosis in vivo

Evaluación de proyectos de inversión privada - AF131 201801

Curso general de la Facultad de Negocios, de carácter teórico-práctico dirigido a los estudiantes de séptimo ciclo, que busca desarrollar las competencias generales de Razonamiento Cuantitativo y de Manejo de Información. Este curso permite al estudiante desarrollar criterios sólidos, necesarios para la toma de decisiones de inversión utilizando la evaluación de proyectos como una herramienta de apoyo financiero a estas decisiones gerenciales. La evaluación de proyectos de inversión es una herramienta financiera que ayuda a resolver de manera eficiente la asignación de los recursos escasos en las organizaciones

CSE induces the expression and production of CCL-2 in A549 cells.

<p><b>(A)</b> After 5 weeks of exposure to CSE 5% or 10%, CCL-2 mRNA expression was measured by real-time PCR. The CCL-2 expression levels were normalized to 18sRNA. Values represent the mean ± SD obtained from three different experiments performed in triplicate. * p <0.001 versus untreated control. <b>(B)</b> The levels of CCL-2 in supernatants were examined by ELISA in cells exposed for 5 weeks to CSE 5% or 10%. Values represent the mean ± SD obtained from four different experiments performed in triplicate. CTRL = A549 unstimulated, CSE 5% = A549 exposed to CSE 5%, CSE 10% = A549 exposed to CSE 10%. *p <0.001 versus untreated control.</p

Exposure to CSE induces morphological changes in epithelial cells with a higher migratory capacity.

<p><b>(A)</b> A549 exposed for 5 weeks to different concentrations of cigarette smoke extract. (a) Control, (b) CSE 1%, (c) CSE 5%, (d) CSE 10%. <b>(B) (a)</b> A549 cells showed faster wound closure at 72 hours in the presence of 5 and 10% of CSE; <b>(b)</b> The percent of closed wound area was calculated versus the initial time of each condition with the ImageJ software. Values represent the mean ± SD obtained from three different experiments. *p<0.01 versus untreated controls.</p

Lung epithelial cells exposed to CSE express genes and produce proteins related to fibroblast phenotype.

<p><b>(A)</b> The levels of mRNA expression were measured by real-time PCR in A549 cells after 5 weeks of exposure to CSE (5% and 10%). The expression levels of all genes were normalized to 18sRNA. Ctrl = Control cells, CSE 5% = A549 exposed to 5% cigarette smoke extract, CSE 10% = A549 exposed to 10% CSE. Values represent the mean ± SD obtained from three different experiments performed in triplicate. *p <0.001 versus untreated control. <b>(B)</b> After 5 weeks of exposure, levels of EMT-related proteins (vimentin, fibronectin and MMP-9) were measured by Western blotting in cell lysates of A549, MLE-12 and RLE-6TN. b-tubulin was used as endogenous protein. Blots are representative of two independent experiments.</p