Pancreatic regeneration in chronic pancreatitis requires activation of the notch signaling pathway

J Gastrointest Surg. 2006 Nov;10(9):1230-41; discussion 1242. doi: 10.1016/j.gassur.2006.08.017.

Abstract

Chronic pancreatitis as an inflammatory process characterized by morphological changes, pancreatic dysfunction, and pain. During pancreatic injury and repair the Notch signaling pathway is reinstated. The current study analyzed this pathway in chronic pancreatitis and characterized its influence on fibrogenesis. Real-time quantitative PCR and immunohistochemistry were used for expression studies. Notch activation was determined by a specific luciferase-HES-1-reporter gene constructs. Cells were stimulated with alcohol, glucose, bile acids, and steroids. Notch-2, -3, and -4 mRNA, were overexpressed in chronic pancreatitis specimens. The ligands Jagged-1, -2, and Delta-1 were highly overexpressed. Jagged-1 and Notch receptors were observed in nerves, regenerating exocrine cells, and endocrine cells. Delta staining was present in ductal but not in acinus cells and not in nerves. Activation of Notch signaling was detectable upon cell stimulation with glucose, steroids, and bile acids. High glucose levels were further associated with increased collagen-I production. The Notch pathway is reactivated during chronic pancreatitis. Among the stimuli activating the Notch pathway are steroids, high glucose levels, and bile acids. These findings suggest a possible role of the Notch pathway during pancreatic regeneration since Jagged-1 inhibits inducible collagen-1 production, suggesting a new mechanism of tissue repair in this disease.

MeSH terms

  • Animals
  • Blotting, Northern
  • Blotting, Western
  • Calcium-Binding Proteins / genetics*
  • Calcium-Binding Proteins / metabolism
  • Cells, Cultured
  • Collagen Type I / metabolism
  • Fibroblasts / metabolism
  • Fibrosis
  • Gene Expression
  • Humans
  • Intercellular Signaling Peptides and Proteins / genetics*
  • Intercellular Signaling Peptides and Proteins / metabolism
  • Intracellular Signaling Peptides and Proteins
  • Jagged-1 Protein
  • Ligands
  • Luciferases, Renilla
  • Membrane Proteins / genetics*
  • Membrane Proteins / metabolism
  • Mice
  • NIH 3T3 Cells
  • Pancreas / physiology*
  • Pancreatitis, Alcoholic / metabolism
  • Pancreatitis, Alcoholic / pathology*
  • Pancreatitis, Chronic / metabolism
  • Pancreatitis, Chronic / pathology*
  • RNA / isolation & purification
  • Receptors, Notch / genetics*
  • Receptors, Notch / metabolism
  • Regeneration*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Serrate-Jagged Proteins
  • Signal Transduction*
  • Transfection

Substances

  • Calcium-Binding Proteins
  • Collagen Type I
  • Intercellular Signaling Peptides and Proteins
  • Intracellular Signaling Peptides and Proteins
  • JAG1 protein, human
  • Jag1 protein, mouse
  • Jagged-1 Protein
  • Ligands
  • Membrane Proteins
  • Receptors, Notch
  • Serrate-Jagged Proteins
  • delta protein
  • RNA
  • Luciferases, Renilla