title: Cytosolic phospholipase A2 (cPLA2) IVA as a potential signature molecule in cigarette smoke condensate induced pathologies in alveolar epithelial lineages.
abstract: BACKGROUND
  Smoking is one of the leading causes of millions of deaths worldwide. During cigarette smoking, most affected and highly exposed cells are the alveolar epithelium and generated oxidative stress in these cells leads to death and damage. Several studies suggested that oxidative stress causes membrane remodeling via Phospholipase A2s but in the case of cigarette smokers, mechanistically study is not yet fully defined. In view of present perspective, we evaluated the involvement of cytosolic phospholipase A2 (cPLA2) IVA as therapeutic target in cigarette smoke induced pathologies in transformed type I and type II alveolar epithelial cells.
  
  
  METHODS
  Transformed type I (WI26) and type II (A549) alveolar epithelial cells were used for the present study. Cigarette smoke condensate (CSC) was prepared from most commonly used cigarette (Gold Flake with filter) by the Indian population. CSC-induced molecular changes were evaluated through cell viability using MTT assay, reactive oxygen species (ROS) measurement using 2,7 dichlorodihydrofluorescin diacetate (DCFH-DA), cell membrane integrity using fluorescein diacetate (FDA) and ethidium bromide (EtBr) staining, super oxide dismutase (SOD) levels, cPLA2 activity and molecular involvement of specific cPLA2s at selected 24 h time period.
  
  
  RESULTS
  CSC-induced response on both type of epithelial cells shown significantly reduction in cell viability, declined membrane integrity, with differential escalation of ROS levels in the range of 1.5-15 folds and pointedly increased cPLA2 activity (p < 0.05). Likewise, we observed distinction antioxidant potential in these two types of lineages as type I cells had considerably higher SOD levels when compared to type II cells (p < 0.05). Further molecular expression of all cPLA2s increased significantly in a dose dependent manner, specifically cytosolic phospholipase A2 IVA with maximum manifestation of 3.8 folds. Interestingly, CSC-induced ROS levels and cPLA2s expression were relatively higher in A549 cells as compared to WI26 cells.
  
  
  CONCLUSIONS
  The present study indicates that among all cPLA2s, specific cPLA2 IVA are the main enzymes involved in cigarette smoke induced anomalies in type I and type II lung epithelial cells and targeting them holds tremendous possibilities in cigarette smoke induced lung pathologies.
authors.affiliation: Department of Biophysics, PGIMER Chandigarh, Chandigarh, 160012, India. subodhbiotech@gmail.com.|Present address: Department of CSIC, PGIMER Chandigarh, Chandigarh, 160012, India. subodhbiotech@gmail.com.
authors.forename: Subodh K
authors.initials: SK
authors.lastname: Yadav
authors.affiliation: Department of Biophysics, PGIMER Chandigarh, Chandigarh, 160012, India.
authors.forename: Sanjeev K
authors.initials: SK
authors.lastname: Sharma
authors.affiliation: Institute of Nuclear Medicine and Allied Sciences, New Delhi, India.
authors.forename: Abdullah
authors.initials: A
authors.lastname: Farooque
authors.affiliation: Department of Biophysics, PGIMER Chandigarh, Chandigarh, 160012, India.|Present address: Surgery, School of Medicine, KU Medical Center (KUMC), Kansas City, KS, 66160, USA.
authors.forename: Gaurav
authors.initials: G
authors.lastname: Kaushik
authors.affiliation: Department of Biophysics, PGIMER Chandigarh, Chandigarh, 160012, India.
authors.forename: Balwinder
authors.initials: B
authors.lastname: Kaur
authors.affiliation: Department of Biophysics, PGIMER Chandigarh, Chandigarh, 160012, India.
authors.forename: Chander M
authors.initials: CM
authors.lastname: Pathak
authors.affiliation: Institute of Nuclear Medicine and Allied Sciences, New Delhi, India.|Present address: Central Research Facility, Sri Ramachandra University, Porur, Chennai, 600116, India.
authors.forename: Bilikere S
authors.initials: BS
authors.lastname: Dwarakanath
authors.affiliation: Department of Biophysics, PGIMER Chandigarh, Chandigarh, 160012, India. klkhanduja@gmail.com.
authors.forename: Krishan L
authors.initials: KL
authors.lastname: Khanduja
mesh_terms: D000072283:A549 Cells; D002460:Cell Line; D003600:Cytosol / Q000201:enzymology*; D004847:Epithelial Cells / Q000648:ultrastructure; D006801:Humans; D008171:Lung Diseases / Q000201:enzymology*; D054467:Phospholipases A2 / Q000032:analysis*; D011650:Pulmonary Alveoli / Q000648:ultrastructure*; D017382:Reactive Oxygen Species / Q000032:analysis; D012906:Smoke / Q000009:adverse effects*; D014026:Nicotiana
chemical_list: D017382:Reactive Oxygen Species; D012906:Smoke; D054467:Phospholipases A2
keywords: A549 cells; Cigarette smoke condensate; Cytosolic phospholipases A2; Inflammation; Reactive oxygen species; WI26 cells