Comparison of proteomic and transcriptomic profiles in the bronchial airway epithelium of current and never smokers.
BACKGROUND
Although prior studies have demonstrated a smoking-induced field of molecular injury throughout the lung and airway, the impact of smoking on the airway epithelial proteome and its relationship to smoking-related changes in the airway transcriptome are unclear.


RESULTS
Airway epithelial cells were obtained from never (n = 5) and current (n = 5) smokers by brushing the mainstem bronchus. Proteins were separated by one dimensional polyacrylamide gel electrophoresis (1D-PAGE). After in-gel digestion, tryptic peptides were processed via liquid chromatography/ tandem mass spectrometry (LC-MS/MS) and proteins identified. RNA from the same samples was hybridized to HG-U133A microarrays. Protein detection was compared to RNA expression in the current study and a previously published airway dataset. The functional properties of many of the 197 proteins detected in a majority of never smokers were similar to those observed in the never smoker airway transcriptome. LC-MS/MS identified 23 proteins that differed between never and current smokers. Western blotting confirmed the smoking-related changes of PLUNC, P4HB1, and uteroglobin protein levels. Many of the proteins differentially detected between never and current smokers were also altered at the level of gene expression in this cohort and the prior airway transcriptome study. There was a strong association between protein detection and expression of its corresponding transcript within the same sample, with 86% of the proteins detected by LC-MS/MS having a detectable corresponding probeset by microarray in the same sample. Forty-one proteins identified by LC-MS/MS lacked detectable expression of a corresponding transcript and were detected in <or=5% of airway samples from a previously published dataset.


CONCLUSIONS
1D-PAGE coupled with LC-MS/MS effectively profiled the airway epithelium proteome and identified proteins expressed at different levels as a result of cigarette smoke exposure. While there was a strong correlation between protein and transcript detection within the same sample, we also identified proteins whose corresponding transcripts were not detected by microarray. This noninvasive approach to proteomic profiling of airway epithelium may provide additional insights into the field of injury induced by tobacco exposure.
The Pulmonary Center, Boston University Medical Center, Boston, Massachusetts, United States of America. steiling@bu.edu
Katrina
K
Steiling
Aran Y
AY
Kadar
Agnes
A
Bergerat
James
J
Flanigon
Sriram
S
Sridhar
Vishal
V
Shah
Q Rushdy
QR
Ahmad
Jerome S
JS
Brody
Marc E
ME
Lenburg
Martin
M
Steffen
Avrum
A
Spira
D000328:Adult; D015153:Blotting, Western; D001980:Bronchi / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D002853:Chromatography, Liquid / Q000379:methods; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D005260:Female; D020869:Gene Expression Profiling; D006023:Glycoproteins / Q000378:metabolism; D006801:Humans; D008297:Male; D046228:Microarray Analysis; D008875:Middle Aged; D008969:Molecular Sequence Data; D010750:Phosphoproteins / Q000378:metabolism; D011393:Procollagen-Proline Dioxygenase / Q000378:metabolism; D019704:Protein Disulfide-Isomerases / Q000378:metabolism; D020543:Proteome / Q000032:analysis*; D020545:Respiratory Mucosa / Q000166:cytology* / Q000187:drug effects; D012907:Smoking / Q000009:adverse effects*; D053719:Tandem Mass Spectrometry / Q000379:methods; D014598:Uteroglobin / Q000378:metabolism; D055815:Young Adult; D014026:Nicotiana
C485599:BPIFA1 protein, human; D006023:Glycoproteins; D010750:Phosphoproteins; D020543:Proteome; D014598:Uteroglobin; D011393:Procollagen-Proline Dioxygenase; C526497:P4HB protein, human; D019704:Protein Disulfide-Isomerases