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Cigarette Smoke Extract‐Induced Injury in Alveolar Cells in Cell Culture Model Systems
Author(s) -
Downs Charles A,
Montgomery David W,
Merkle Carrie J
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.698.7
Subject(s) - antioxidant , chemistry , cigarette smoke , cell culture , telomere , extracellular , andrology , microbiology and biotechnology , gene expression , intracellular , pharmacology , gene , biochemistry , medicine , biology , toxicology , genetics
We explored the effects of cigarette smoke extract (CSE) on alveolar type I (AT I) cells and microvascular endothelial cells (MVECs) harvested from the lungs of neonatal (7 days), young (3 months) and old (24 months) male Fischer 344 rats. Single and co‐culture models of AT I and MVECs were used. CSE concentration was standardized spectrophotometrically using the smoke from one research grade (1R5F) cigarette dissolved in 10 mL of RPMI 1640 with 10% FBS. Cells were exposed to CSE for 24 hours and then assayed for intracellular ROS, extracellular H 2 O 2 , and total antioxidant capacity. Telomere length was determined after exposure to 2% CSE for 3 weeks using qRT‐PCR. ROS production in AT I cells did not change with CSE challenge while H 2 O 2 production by MVECs increased 2 to 2.5 fold. Interestingly, when AT I and MVECs were grown as co‐cultures, H 2 O 2 levels were reduced 1 to 4 fold compared to MVECs cultured alone. The total antioxidant capacity of AT I cells was greater (~8 fold) than MVECs which may explain the reduction of H 2 O 2 levels. Gene expression profiling specific to oxidant and antioxidant pathways revealed 9 genes that were significantly different in MVECs grown in co‐culture compared to single cultures. CSE exposure shortened neonatal telomeres (p<0.05) while CSE exposure did not shorten young and old AT I cells (p<0.05) nor did CSE affect telomere length in young and old MVECs. Gene expression profiling identified 6 genes in neonates and 7 genes in old AT I cells that were affected by CSE exposure and the data suggest that CSE exposure stimulated cell division in neonates and promoted growth arrest in old AT I cells. The results of these studies may provide insight into mechanisms of CSE‐induced injury and possible therapeutic strategies to reduce lung injury secondary to smoking and related environmental exposures.