Identification of pancreas-specific proteins in endoscopically (endoscopic pancreatic function test) collected pancreatic fluid with liquid chromatography--tandem mass spectrometry.
OBJECTIVE
We aimed to establish the endoscopic pancreatic function test (ePFT) as a method that can safely obtain pancreatic fluid for mass spectrometric analysis from patients during upper endoscopy and to reproducibly identify pancreas-specific proteins.


METHODS
We performed a sodium dodecyl sulfate-polyacrylamide gel electrophoresis and mass spectrometry-based proteomic analysis (in-gel tryptic digestion followed by liquid chromatography-tandem mass spectrometry [GeLC-MS/MS]) on ePFT-collected pancreatic fluid from 3 individuals, without evidence of chronic pancreatitis, who were undergoing an upper endoscopy for dyspepsia and chronic abdominal pain.


RESULTS
Pancreatic fluid was safely collected from all subjects. The sodium dodecyl sulfate-polyacrylamide gel electrophoretic analysis of ePFT-collected pancreatic fluid revealed no significant variation (F statistic, 1.33, P = 0.29) in protein concentration during the 1-hour collection period and a visually reproducible protein banding pattern among the 3 subjects. The GeLC-MS/MS analysis of ePFT-collected fluid identified pancreas-specific proteins previously described from endoscopic retrograde cholangiopancreatography and surgical collection methods. Gene ontology further revealed that most of the proteins identified have a molecular function of proteases.


CONCLUSIONS
The ePFT is capable of collecting large amounts of pancreatic fluid for proteomic analysis enabling the identification of pancreas-specific proteins. This endoscopic collection method coupled with GeLC-MS/MS is a powerful technique, which can be used in future investigations to elucidate pathways involved in the development and progression of pancreatic disease.
Paulo
Joao A
JA
Center for Pancreatic Disease, Division of Gastroenterology, Hepatology, and Endoscopy, Brigham and Women's Hospital, 75 Francis St, Boston, MA 02115, USA.
Lee
Linda S
LS
Wu
Bechien
B
Repas
Kathryn
K
Mortele
Koenraad J
KJ
Banks
Peter A
PA
Steen
Hanno
H
Conwell
Darwin L
DL
D001826:Body Fluids / Q000378:metabolism; D002853:Chromatography, Liquid / Q000379:methods*; D015331:Cohort Studies; D004591:Electrophoresis, Polyacrylamide Gel; D016145:Endoscopy, Digestive System; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010179:Pancreas / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D010186:Pancreatic Function Tests / Q000379:methods; D011506:Proteins / Q000032:analysis*; D040901:Proteomics / Q000379:methods; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000379:methods*
D011506:Proteins