AIM:Activated pancreatic stellate cells(PSCs)have beenimplicated in the pathogenesis of pancreatic fibrosis andinflammation.Primary PSCs can be subcultured only severaltimes because of their limited growth potential.A continuouscell line may therefore be valuable in studying molecularmechanisms of these pancreatic disorders.The aim of thisstudy was to establish a cell line of rat PSCs by spontaneousimmortalization.METHODS:PSCs were isolated from the pancreas of maleWistar rats,and conventional subcultivation was performedrepeatedly.Telomerase activity was measured using thetelomere repeat amplification protocol.Activation of transcriptionfactors was assessed by electrophoretic mobility shift assay.Activation of mitogen-activated protein(MAP)kinases wasexamined by Western blotting using anti-phosphospecificantibodies.Expression of cytokine-induced neutrophilchemoattractant-1 was determined by enzyme immunoassay.RESULTS:Conventional subcultivation yielded activelygrowing cells.One clone was obtained after limiting dilution,and designated as SIPS.This cell line has been passagedrepeatedly more than 2 years,and is thus likely immortalized.SIPS cells retained morphological characteristics of primary,culture-activated PSCs.SIPS expressed α-smooth muscleactin,glial acidic fibrillary protein,vimentin,desmin,type Ⅰcollagen,fibronectin,and prolyl hydroxylases.Telomeraseactivity and p53 expression were negative.Proliferation ofSIPS cells was serum-dependent,and stimulated withplatelet-derived growth factor-BB through the activation ofextracellular signal-regulated kinase.Interleukin-1β activatednuclear factor-κB,activator protein-1,and MAP kinases.Interleukin-1β induced cytokine-induced neutrophilchemoattractant-1 expression through the activation ofnuclear factor-κB and MAP kinases.CONCLUSION: SIPS cells can be useful for in vitro studies of cell biology and signal transduction of PSCs. AIM: Activated pancreatic stellate cells (PSCs) have been disseminated in the pathogenesis of pancreatic fibrosis and inflamation. Primary PSCs can be subcultured only several times because of their limited growth potential. A continuous cell line may therefore be valuable in studying molecular mechanisms of these pancreatic disorders. of this study was to establish a cell line of rat PSCs by spontaneous imMortalization. METHODS: PSCs were isolated from the pancreas of male Wistar rats, and conventional subcultivation was performed repeatedly. DNA activity was measured using the telomere repeat amplification protocol. Activation of transcription factors were assessed by electrophoretic mobility shift assay. Activation of mitogen-activated protein (MAP) kinases wasexamined by Western blotting using anti-phosphospecific antibodies. Expression of cytokine-induced neutrophil chemoattractant-1 was determined by enzyme immunoassay .RESULTS: Conventional subcultivation of suppressed actively growing cells. Ocone clone was obtained after limiting dilution, and designated as SIPS. This cell line has been passagedrepeated more than 2 years, and is likely to be likely to be immortalized. SIPS cells retained morphological characteristics of primary, culture-activated PSCs.SIPS expressed α-smooth muscle actin, glial acidic fibrillary protein, vimentin, desmin, type Icollagen, fibronectin, and prolyl hydroxylases. Te activity and p53 expression were negative. Proliferation of SIPS cells was serum-dependent, and stimulated with platelet-derived growth factor-BB through the activation of extracellular signal-regulated kinase. interleukin -1β activated nuclear factor-κB, activator protein-1, and MAP kinases. Interleukin-1β induced cytokine-induced neutrophilchemoattractant-1 expression through the activation of nuclear factor-κB and MAP kinases. CONCLUSION: SIPS cells can be useful for in vitro studies of cell biology and signal transduction of PSCs.