4-hydroxy-2,3-nonenal activates activator protein-1 ant mitogen-activated protein kinases in rat pancreatic stellate cells

AIM: Activated pancreatic stellate cells (PSCs) are implicated in the pathogenesis of pancreatic inflammation and fibrosis,where oxidative stress is thought to play a key role. 4-hydroxy-2,3-nonenal (HNE) is generated endogenously during the process of lipid peroxidation, and has been accepted as a mediator of oxidative stress. The aim of this study was to clarify the effects of HNE on the activation of signal transduction pathways and cellular functions in PSCs.METHODS: PSCs were isolated from the pancreas of male Wistar rats after perfusion with collagenase P, and used in their culture-activated, myofibroblast-like phenotype unless otherwise stated. PSCs were treated with physiologically relevant and non-cytotoxic concentrations (up to 5 μmol/L) of HNE. Activation of transcription factors was examined by electrophoretic mobility shift assay and luciferase assay.Activation of mitogen-activated protein (MAP) kinases was assessed by Western blotting using anti-phosphospecific antibodies. Cell proliferation was assessed by measuring the incorporation of 5-bromo-2'-deoxyuridine. Production of type Ⅰ collagen and monocyte chemoattractant protein-1 was determined by enzyme-linked immunosorbent assay.The effect of HNE on the transformation of freshly isolated PSCs in culture was also assessed.RESULTS: HNE activated activator protein-1, but not nuclear factor KB. In addition, HNE activated three classes of MAP kinases: extrcellular signal-regulated kinase, c-jun N-terminal kinase, and p38 MAP kinase. HNE increased type I collagen production through the activation of p38 MAP kinase and c-jun N-terminal kinase. HNE did not alter the proliferation,or monocyte chemoattractant protein-1 production. HNE did not initiate the transformation of freshly isolated PSCs to myofibroblast-like phenotype.CONCLUSION: Spedflc activation of these signal transduction pathways and altered cell functions such as collagen production by HNE may play a role in the pathogenesis of pancreatic disorders.

AIM:Activated pancreatic stellate cells (PSCs) are implicated in the pathogenesis of pancreatic inflammation and fibrosis, where oxidative stress is thought to play a key role.4-hydroxy- 2,3-nonenal (HNE) is generated endogenously during the process of lipid peroxidation,and has been accepted as a mediator of oxidative stress.The aim of this study was to clarify the effects of HNE on the activation of signal transduction pathways and cellular functions in PSCs. METHODS:PSCs were isolated from the pancreas of male Wistar rats after perfusion with collagenase P,and used in their culture-activated,myofibroblast-like phenotype unless otherwise stated.PSCs were treated with physiologically relevant and non-cytotoxic concentrations (up to 5μmol/L) of HNE.Activation of transcription factors was examined by electrophoretic mobility shift assay and luciferase assay. Activation of mitogen-activated protein (MAP) kinases was assessed by Western blotting using anti-phosphospecific antibodies.Cell proliferation was assessed by measuring the incorporation of 5-bromo-2'-deoxyuridine.Production of type I collagen and monocyte chemoattractant protein-1 was determined by enzyme-linked immunosorbent assay. The effect of HNE on the transformation of freshly isolated PSCs in culture was also assessed. RESULTS:HNE activated activator protein-1,but not nudear factor kB.In addition,HNE activated three classes of MAP kinases:extracellular signal-regulated kinase,c-Jun N-terminal kinase,and p38 MAP kinase.HNE increased type Ⅰ collagen production through the activation of p38 MAP kinase and c-Jun N-terminal kinase.HNE did not alter the proliferation, or monocyte chemoattractant protein-1,production.HNE did not initiate the transformation of freshly isolated PSCs to myofibroblast-like phenotype. CONCLUSION:Specific activation of these signal transduction pathways and altered cell functions such as collagen production by HNE may play a role in the pathogenesis of pancreatic disorders.