title: Activation of different pathways of apoptosis by air pollution particulate matter (PM2.5) in human epithelial lung cells (L132) in culture.
abstract: Epidemiological studies have associated the increase of respiratory and cardiovascular mortality and morbidity with high levels of air pollution particulate matter (PM). However, the underlying mechanisms of actions by which PM induce adverse health effects are still unclear. We have recently undertaken an extensive investigation of the adverse health effects of air pollution PM(2.5), and shown that in vitro short-term exposure to PM(2.5) induced oxidative stress and inflammation in human lung epithelial cells (L132). Hence, it was convenient to complete the physical and chemical characterization of PM and to investigate whether in vitro short-term exposure to PM could be imply in the activation of apoptosis. Accordingly, we found that 92.15% of PM were equal or smaller than 2.5 microm and their specific surface area was 1m(2)/g. Inorganic (i.e. Fe, Al, Ca, Na, K, Mg, Pb, etc.) and organic (i.e. polycyclic aromatic hydrocarbons) chemicals were found in PM, suggesting that much of them derived from wind-borne dust from the industrial complex and the heavy motor vehicle traffic. In other respects, we showed that PM exposure induced apoptosis by activating not only the tumor necrosis factor-alpha (TNF-alpha)-induced pathway (i.e. TNF-alpha secretion, caspase-8 and -3 activation), but also the mitochondrial pathway (i.e. 8-hydroxy-2'-desoxyguanosine formation, cytochrome c release from mitochondria, caspase-9 and -3 activation). Moreover, changes in the transcription rates of p53, bcl-2, and bax genes, on the one hand, and DNA fragmentation, on the other hand, were reported in PM-exposed proliferating L132 cells, revealing the occurrence of apoptotic events. Taken together, these findings suggested that in vitro short-term exposure to PM(2.5) induced apoptosis in L132 cells.
authors.affiliation: LCE EA2598, Toxicologie Industrielle et Environnementale, Maison de la Recherche en Environnement Industriel de Dunkerque 2, 189A, Avenue Maurice Schumann, 59140 Dunkerque, France.
authors.forename: Zeina
authors.initials: Z
authors.lastname: Dagher
authors.forename: Guillaume
authors.initials: G
authors.lastname: Garçon
authors.forename: Sylvain
authors.initials: S
authors.lastname: Billet
authors.forename: Pierre
authors.initials: P
authors.lastname: Gosset
authors.forename: Frédéric
authors.initials: F
authors.lastname: Ledoux
authors.forename: Dominique
authors.initials: D
authors.lastname: Courcot
authors.forename: Antoine
authors.initials: A
authors.lastname: Aboukais
authors.forename: Pirouz
authors.initials: P
authors.lastname: Shirali
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000393:Air Pollutants / Q000032:analysis / Q000633:toxicity*; D000397:Air Pollution / Q000009:adverse effects* / Q000032:analysis; D017209:Apoptosis / Q000187:drug effects*; D020169:Caspases / Q000378:metabolism; D002460:Cell Line; D045304:Cytochromes c / Q000378:metabolism; D053938:DNA Fragmentation / Q000187:drug effects; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000378:metabolism; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D005602:France; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D008168:Lung / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D008670:Metals / Q000032:analysis / Q000633:toxicity; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D010316:Particle Size; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis / Q000633:toxicity; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism; D051028:bcl-2-Associated X Protein / Q000235:genetics / Q000378:metabolism
chemical_list: D000393:Air Pollutants; D008670:Metals; D011084:Polycyclic Aromatic Hydrocarbons; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D016159:Tumor Suppressor Protein p53; D051028:bcl-2-Associated X Protein; D000080242:8-Hydroxy-2'-Deoxyguanosine; D045304:Cytochromes c; D020169:Caspases; D003849:Deoxyguanosine