Pancreatic stellate cells (PaSC) are emerging as key mediators in
chronic pancreatitis and
pancreatic cancer pathogenesis.
Proteins regulating the biomolecular pathways involved in the conversion of quiescent to activated PaSC may have a significant influence on the development of
chronic pancreatitis. We aim to compare differentially expressed
proteins in activated and serum-starved non-proliferating PaSC using a mass spectrometry-based proteomics strategy. We cultured an immortalized rat PaSC cell line in media supplemented with 10%
fetal bovine serum and in
serum-free media. Using gel-based mass spectrometry (GeLC-MS/MS), we identified nearly 1500
proteins. Qualitative and quantitative proteomic analysis revealed several hundred
proteins as differentially abundant between the two cell states.
Proteins of greater abundance in activated PaSC included
isoforms of actin (e.g., smooth muscle actin) and
ribosomal proteins. Conversely,
proteins more abundant in non-proliferating PaSC than in activated PaSC included signaling
proteins MAP
kinase 3 and Ras-related
proteins. In addition, we have determined the molecular functions and
biological pathways for these
proteins. We are confident that the application of mass spectrometry-based strategies, such as that described herein, to investigate specific
proteins in PaSC may lead to a better understanding of the molecular mechanisms involved in
pancreatic diseases, such as
chronic pancreatitis.