title: Smad2/3 Linker Phosphorylation Is a Possible Marker of Pancreatic Stem/Progenitor Cells in the Regenerative Phase of Acute Pancreatitis.
abstract: The aims of this study are to characterize cell proliferation and differentiation during regeneration after pancreatitis and pancreatic buds during development to evaluate the role of Smad2/3, phosphorylated at the specific linker threonine residues (pSmad2/3L-Thr) in positive cells.
  
  
  
  Male C57BL/6 mice received hourly intraperitoneal injections of cerulein and were analyzed after induced pancreatitis. Pancreatitis-affected tissue sections and pancreatic buds were immunostained for pSmad2/3L-Thr, with other markers thought to be stem/progenitor markers of the pancreas.
  
  
  
  pSmad2/3L-Thr immunostaining-positive cells increased as the pancreatitis progressed. The expression of pSmad2/3L-Thr was seen in acinar cells and ductlike tubular complexes. These results suggest that pSmad2/3L-Thr is expressed during acinar-ductal metaplasia. Immunohistochemical colocalization of pSmad2/3L-Thr with Ki67 was never observed. pSmad2/3L-Thr-positive cells may remain in an undifferentiated state. During the pancreatic development process, pSmad2/3L-Thr was expressed as other markers. pSmad2/3L-Thr develops in duct structure of the undifferentiated cell population in the last part of viviparity that acinar structure is formed clearly.
  
  
  
  pSmad2/3L-Thr expression occurs during acinar-ductal metaplasia after pancreatitis and may represent the contribution of stem cells and/or progenitor cells to the differentiation of the pancreas.
authors.affiliation: From the Third Department of Internal Medicine, Kansai Medical University, Osaka, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Sakao
authors.forename: Yutaku
authors.initials: Y
authors.lastname: Sakaguchi
authors.forename: Ryo
authors.initials: R
authors.lastname: Suzuki
authors.forename: Yu
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Masanobu
authors.initials: M
authors.lastname: Kishimoto
authors.forename: Toshiro
authors.initials: T
authors.lastname: Fukui
authors.forename: Kazushige
authors.initials: K
authors.lastname: Uchida
authors.forename: Akiyoshi
authors.initials: A
authors.lastname: Nishio
authors.forename: Koichi
authors.initials: K
authors.lastname: Matsuzaki
authors.forename: Kazuichi
authors.initials: K
authors.lastname: Okazaki
mesh_terms: D061354:Acinar Cells / Q000473:pathology; D000208:Acute Disease; D000818:Animals; D015415:Biomarkers / Q000378:metabolism*; D002454:Cell Differentiation; D002108:Ceruletide; D008297:Male; D008679:Metaplasia / Q000378:metabolism; D008810:Mice, Inbred C57BL; D010179:Pancreas / Q000166:cytology / Q000378:metabolism; D010183:Pancreatic Ducts / Q000378:metabolism / Q000473:pathology; D010195:Pancreatitis / Q000139:chemically induced / Q000378:metabolism* / Q000503:physiopathology; D010766:Phosphorylation; D012038:Regeneration; D051899:Smad2 Protein / Q000378:metabolism*; D051900:Smad3 Protein / Q000378:metabolism*; D013234:Stem Cells / Q000378:metabolism*; D013912:Threonine / Q000378:metabolism
chemical_list: D015415:Biomarkers; D051899:Smad2 Protein; D051900:Smad3 Protein; D013912:Threonine; D002108:Ceruletide