Isolation of Quiescent Human Pancreatic Stellate Cells: A Promising in vitro Tool for Studies of Human Pancreatic Stellate Cell Biology

Background: Pancreatic stellate cells (PSCs) play a critical role in pancreatic fibrosis. To date, human PSC biology has been studied using cancer-or inflammation-associated (pre-activated) PSCs, but an in vitro model of quiescent normal human PSCs (NhPSCs) has been lacking. Aims: To (i) isolate and characterize quiescent NhPSCs, and (ii) evaluate the response of culture-activated NhPSCs to cytokines and LPS. Methods: Quiescent NhPSCs were isolated from normal pancreatic tissue using density gradient centrifugation. PSC markers, glial fibrillary acidic protein (GFAP), desmin, alpha-smooth muscle actin (alpha SMA) and the lipopolysaccharide (LPS) receptors TLR4 and CD14 were identified by immuno-blotting and immunocytochemistry. The effect of platelet-derived growth factor (PDGF), transforming growth factor beta (TGF beta) and LPS on NhPSC activation was also assessed. Results: Freshly isolated NhPSCs displayed a polygonal appearance with refringent cytoplasmic lipid droplets. Culture-activated NhPSCs expressed GFAP, desmin, alpha SMA, TLR4 and CD14, and were responsive to PDGF, TGF beta and LPS. Conclusion: Isolated NhPSCs expressed the same markers as rat PSCs and human cancer-associated PSCs and responded to PDGF and TGF beta similarly to rat PSCs. NhPSC preparations provide a useful in vitro tool to study the biology of PSCs in their physiological, non-activated state. Copyright (C) 2010 S. Karger AG, Basel and IAP