Proteomic Effects of the Coagulation Proteinase Thrombin on LX-2 Hepatic Stellate Cells

Background: The aim of this study was to characterize the effects of the coagulation proteinase thrombin on proteomic level in human hepatic stellate LX-2 cells. Methods: Proteomic analyses were performed using surface-enhanced laser desorption/ionization-time of flight mass spectrometry (SELDI-TOF-MS). The protein profiles obtained from LX-2 cell lysates using strong anion exchanger Q10 Protein Chip arrays were statistically analyzed. Results: The peak intensities of 50 protein/peptide clusters were identified as being different between nonstimulated and LX-2 cells treated with thrombin for 6 h and 24 h, respectively. As the most significantly enhanced single signal in LX-2 cells stimulated with thrombin, a protein with a molecular mass of 13.560 kDa has been identified that corresponds exactly to calcium dependent phospholipase 2(cPLA2). Thrombin-induced increase in the cPLA2 protein expression in LX-2 cells was confirmed by using the Western blotting technique. Conclusions: Together with the finding that thrombin induced phosphorylating activation of cPLA2 in LX-2 cells, our data point to an important function of the thrombin-mediated modulation of cytosolic phospholipase A2 in hepatic stellate cells.