Project description:Proteasome dysfunction is emerging as a novel pathomechanism for the development of chronic obstructive pulmonary disease (COPD), a major leading cause of death in the world. Cigarette smoke is one of the main risk factors for COPD and has been shown to impair proteasome function in vitro and in vivo. Importantly, proteasome activity is inhibited in COPD lungs while expression levels of proteasome subunits are not altered. In the present study, we dissected the molecular changes induced by cigarette smoke on proteasome function in lung epithelial cells and mouse lungs. We analyzed the integrity, composition, and the interactome of isolated 26S proteasome complexes from smoke-exposed cells and mouse lungs. Moreover, we applied native MS analysis to investigate whether reactive compounds of cigarette smoke directly modify and inhibit the 20S proteasome complex. Our data reveal that the 20S proteasome is slightly destabilized in the absence of any dominant modification of proteasomal proteins. 26S pulldown and stoichiometry analysis indicated that 26S proteasome complexes become instable in response to cigarette smoke exposure. Of note, the interactome of the 26S was clearly altered in smoke-exposed mouse lungs possibly reflecting an altered cellular composition in the lungs of the smoke-exposed mice. Taken together, our results suggest that cigarette smoke induces minor but detectable changes in the stability and interactome of 20S and 26S proteasome complexes which might contribute in a chronic setting to imbalanced proteostasis as observed in chronic lung diseases associated with cigarette smoking.
Project description:Cigarette smoke is the most relevant risk factor for the development of lung cancer and chronic obstructive pulmonary disease. Many of its more than 4500 chemicals are highly reactive, thereby altering protein structure and function. Here, we used subcellular fractionation coupled to label-free quantitative MS to globally assess alterations in the proteome of different compartments of lung epithelial cells upon exposure to cigarette smoke extract. Proteomic profiling of the human alveolar derived cell line A549 revealed the most pronounced changes within the cellular secretome with preferential downregulation of proteins involved in wound healing and extracellular matrix organization. In particular, secretion of secreted protein acidic and rich in cysteine, a matricellular protein that functions in tissue response to injury, was consistently diminished by cigarette smoke extract in various pulmonary epithelial cell lines and primary cells of human and mouse origin as well as in mouse ex vivo lung tissue cultures. Our study reveals a previously unrecognized acute response of lung epithelial cells to cigarette smoke that includes altered secretion of proteins involved in extracellular matrix organization and wound healing. This may contribute to sustained alterations in tissue remodeling as observed in lung cancer and chronic obstructive pulmonary disease.
Project description:To profile lung miRNA expression in our mouse model of cigarette smoke-induced chronic obstructive pulmonary disease, we employed the Agilent unrestricted Mouse miRNA (8 x 15k arrays per slide, AMADID Number: 021828, Sanger Version 12) platform as a discovery tool to identify miRNAs of interest in the development of experimental chronic obstructive pulmonary disease. Mice were exposed to cigarette smoke (or room air) for 4, 6, 8, 12 weeks, lungs were excised, and total RNA isolated.
Project description:Cigarette smoking remains the leading cause of non-small cell lung carcinoma. Studies involving acute exposure of smoke on lung cells revealed induction of pre- cancerous state in lung cells. Recently few studies have reported the chronic effect of cigarette smoke in inducing cellular transformation. Yet no systemic study has been performed to understand the molecular alterations in lung cells due to cigarette smoke. Hence it is both important and necessary to study the chronic effect of cigarette smoke in a temporal setting to understand the molecular alterations. In this study, we carried out TMT based proteomic profiling of lung cells which were exposed to cigarette smoke condensate (CSC) for upto 12 months. We identified 2621 proteins in total, of which 145, 114, 87, 169 and 671 proteins were differentially expressed (p<0.05, 1.5 fold) in 2nd, 4th, 6th, 8th and 12th month respectively. Pathway analysis revealed enrichment of xenobiotic metabolism signaling for the first 8 months of smoke treatment, where as continued exposure of smoke for 12 months revealed mitochondrial reprogramming in cells which includes dysregulation of oxidative phosphorylation machinery leading to enhanced reactive oxygen species and higher expression of enzymes involved in tricarboxylic acid cycle (TCA). In addition, chronic exposure of smoke led to overexpression of enzymes involved in glutamine metabolism, fatty acid degradation and lactate synthesis. This could possibly explain the availability of alternative source of carbon in TCA cycle apart from glycolytic pyruvate. Our data indicates that chronic exposure to cigarette smoke induces mitochondrial metabolic transformation in cells to support growth and survival.
Project description:Cigarette smoke has been associated with the development of various lung diseases including cancer. Dysregulation of miRNAs is known to affect protein expression which leads to diverse functional consequences. Investigating miRNA and protein expression in response to cigarette smoke exposure can lead to the identification of potential therapeutic and chemopreventive targets. We employed a SILAC-based quantitative proteomic analysis to identify proteins differentially expressed in response to cigarette smoke in H292 lung cancer cells. LC-MS/MS analysis led to the identification of 3,959 proteins, of which, 303 proteins were overexpressed and 112 proteins were found to be downregulated in cigarette smoke-treated H292 cells.
Project description:Airway epithelial cells are the first cells of the lungs to be exposed to the toxic agents contained within cigarette smoke. Accordingly, the response of these cells to this challenge is of considerable interest in the context of diseases in which cigarette smoke is a major aetiological factor. We used Affymetrix microarrays to study the effects of repeated cigarette smoke challenge on three-dimensional human lung airway epithelial cultures.
Project description:Although smoking-induced lung disease tends to be more common in the upper lobe, it is not known if this results from the skewed distribution of inhaled cigarette smoke or increased susceptibility of the upper lobes to these disorders. The distribution of inhaled cigarette smoke within the lung is complex, depending on lung pressure-volume relationships, gravity, individual smoking habits and the properties of the individual components of cigarette smoke. With the knowledge that the small airway epithelium is the earliest site of smoking-induced lung disease, and that the small airway epithelium is acutely sensitive to inhaled cigarette smoke with significant changes in the up- and down-regulation of hundreds of genes, we compared upper vs lower lobe gene expression in the small airway epithelium of the same cigarette smokers to determine if the gene expression patterns were similar or different. Active smokers (n=11) with early evidence of smoking-induced lung disease (normal spirometry but low diffusing capacity) underwent bronchoscopy and brushing of the small airway epithelium to compare upper vs lower lobe genome-wide gene expression assessed by microarray. Interestingly, cluster and principal component analysis demonstrated that, for each individual, the expression of the known small airway epithelium smoking-responsive genes were remarkably similar as upper vs lower lobe pairs, although, as expected, there were differences in the smoking-induced changes in gene expression from individual to individual. Thus, while there may be topographic differences in the distribution of cigarette smoke, sufficient smoke reaches the upper vs lower lobe small airway epithelium so that, within each smoker, the upper vs lower lobe gene expression are similar. These observations support the concept that the topographic differences in the occurrence of the smoking-induced lung diseases are likely secondary to topographic differences in the susceptibility of the upper vs lower lobes to cigarette smoke, not the topographic differences in distribution of inhaled cigarette smoke.
Project description:The lymphatic vasculature is critical for lung function, but defects in lymphatic functionin the pathogenesis of lung disease is understudied. To further assess the contribution of lymphatics to the pathogenesis of lung emphysema we used a mouse model of cigarette smoke (CS)-induced emphysema, and analyzed lung lymphatics using immunohistochemistry, functional assays, and confocal microscopy. Additionally, we further harvested thoracic lymph from CS-exposed mice for proteomic analysis. In this presented section of our research, we highlight the label free quantitative DIA proteomics approaches used to profile the proteomic and peptidomics changes in the lymph from cigarette smoke (CS)-mice as compared with the lymph proteome from mice exposed to room air. Label free quantitative DIA proteomics analysis of lymph confirmed upregulation of coagulation and inflammatory pathways in the lymphatics of CS-exposed mice compared to control mice.
Project description:Epidemiological data clearly establishes cigarette smoking as one of the major cause for lung cancer worldwide. There is no standard screening method for lung cancer even in high-risk populations and the overall five-year survival has not changed significantly in the last decade. First-line treatment for lung cancer includes surgical resection, chemotherapy, and radiation. Recently with the advancement of systems biology, targeted therapy has become one of the most preferred modes of treatment for cancer. Though certain targeted therapies such as anti-EGFR are in clinical practice, they have shown limited success in the smokers suffering from lung cancer. This demands the discovery of alternative drug targets through systematic investigation of altered signaling mechanisms. To study dysregulated signaling pathways due to chronic cigarette smzoke exposure, we carried out SILAC-based phosphoproteome analysis of lung cell line H358 chronically exposed to cigarette smoke. We identified 1,812 phosphosites, of which 278 were hyperphosphorylated (≥ 3-fold) in the H358 cells exposed to cigarette smoke. We identified several known and some novel kinases and key signaling molecules that were hyperphosphorylated in response to chronic exposure to cigarette smoke