[Frontiers in Bioscience E4, 2402-2409, June 1, 2012]

Cigarette smoke enhances chemotaxis via acetylation of proline-glycine-proline

Matthew Thomas Hardison1, Michael David Brown1, Robert James Snelgrove2, James Edwin Blalock1, Patricia Jackson1

1Department of Medicine University of Alabama at Birmingham 1918 University Blvd., Birmingham, AL 35294, 2National Heart and Lung Institute, Imperial College London, South Kensington Campus, London UK SW7 2, AZ

TABLE OF CONTENTS

1. Abstract
2. Introduction
3. Materials and methods
3.1. Materials
3.2. Methods
3.2.1. Preparation of cigarette smoke extract or condensate (CSE or CSC)
3.2.2. CSE/CSC PGP acetylation assay
3.2.3. CSE/CSC Vapor acetylation assay
3.2.4. PMN chemotaxis assay
3.2.5. CSE/CSC PGP acetylation assay with N-acetyl-cysteine and carbocysteine
3.2.6. CSC/CSE vapor acetylation assay with NAC and carbocysteine
3.2.7. Statistical analysis
4. Results
5. Discussion
6. Acknowledgements
7. References

1. ABSTRACT

Several chronic lung diseases have been linked to cigarette smoking (Chronic Obstructive Pulmonary Disease (COPD), and cancer are associated with increased tobacco use). We recently described a collagen fragment, proline-glycine-proline (PGP), chemotactic for neutrophils, that appears to play a role in COPD, cystic fibrosis, and bronchiolitis obliterans syndrome. PGP can exist in either its native or acetylated form (NAcPGP), although the mechanism of N-terminal-acetylation remains unknown. This work investigates the possibility that cigarette smoke (CS) and its components acetylate PGP, describing a possible mechanism for some of the chronic inflammation seen in tobacco-associated disease. CSE and CSC (3.56 and 12.38 ng/ml NAcPGP respectively, p less than 0.01) and its components (acrolein, acetaldehyde, and methyl glyoxal) acetylated PGP (0.51, 1.03, and 0.23 ng/ml NAcPGP, p less than 0.01). Both N-acetyl-cysteine and carbocysteine (scavengers of reactive aldehydes) blocked chemical acetylation of PGP by CS (100 percent and 97 percent inhibition, respectively, p less than 0.01). NAcPGP is more chemoattractive to neutrophils, and less susceptible to degradation by Leukotriene-A4-Hydrolase (detected in the lung). These experiments propose a mechanism for the increased neutrophil recruitment seen in smoking-associated lung diseases.