title: Tissue Remodelling following Resection of Porcine Liver.
abstract: OBJECTIVE
  To study genes regulating the extracellular matrix (ECM) and investigate the tissue remodelling following liver resection in porcine.
  
  
  METHODS
  Four pigs with 60% partial hepatectomy- (PHx-) induced liver regeneration were studied over six weeks. Four pigs underwent sham surgery and another four pigs were used as controls of the normal liver growth. Liver biopsies were taken upon laparotomy, after three and six weeks. Gene expression profiles were obtained using porcine-specific oligonucleotide microarrays. Immunohistochemical staining was performed and a proliferative index was assessed.
  
  
  RESULTS
  More differentially expressed genes were associated with the regulation of ECM in the resection group compared to the sham and control groups. Secreted protein acidic and rich in cysteine (SPARC) and collagen 1, alpha 2 (COL1A2) were both upregulated in the early phase of liver regeneration, validated by immunopositive cells during the remodelling phase of liver regeneration. A broadened connective tissue was demonstrated by Masson's Trichrome staining, and an immunohistochemical staining against pan-Cytokeratin (pan-CK) demonstrated a distinct pattern of migrating cells, followed by proliferating cell nuclear antigen (PCNA) positive nuclei.
  
  
  CONCLUSIONS
  The present study demonstrates both a distinct pattern of PCNA positive nuclei and a deposition of ECM proteins in the remodelling phase of liver regeneration.
authors.affiliation: Laboratory of Surgical Research, Institute of Clinical Medicine, University of Tromsø, 9037 Tromsø, Norway.
authors.forename: Ingvild Engdal
authors.initials: IE
authors.lastname: Nygård
authors.affiliation: Department of Digestive Surgery, University Hospital of North Norway, 9038 Tromsø, Norway.
authors.forename: Kim Erlend
authors.initials: KE
authors.lastname: Mortensen
authors.affiliation: Department of Genetics and Biotechnology, Faculty of Agricultural Sciences, University of Aarhus, 8830 Tjele, Denmark ; Department of Molecular Medicine, Aarhus University Hospital, Skejby, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark.
authors.forename: Jakob
authors.initials: J
authors.lastname: Hedegaard
authors.affiliation: Department of Genetics and Biotechnology, Faculty of Agricultural Sciences, University of Aarhus, 8830 Tjele, Denmark.
authors.forename: Lene Nagstrup
authors.initials: LN
authors.lastname: Conley
authors.affiliation: Department of Genetics and Biotechnology, Faculty of Agricultural Sciences, University of Aarhus, 8830 Tjele, Denmark.
authors.forename: Christian
authors.initials: C
authors.lastname: Bendixen
authors.affiliation: Molecular Inflammation Research Group, Institute of Medical Biology, University of Tromsø, 9037 Tromsø, Norway.
authors.forename: Baldur
authors.initials: B
authors.lastname: Sveinbjørnsson
authors.affiliation: Laboratory of Surgical Research, Institute of Clinical Medicine, University of Tromsø, 9037 Tromsø, Norway.
authors.forename: Arthur
authors.initials: A
authors.lastname: Revhaug
mesh_terms: D000818:Animals; D005109:Extracellular Matrix / Q000502:physiology*; D016326:Extracellular Matrix Proteins / Q000378:metabolism*; D005260:Female; D005786:Gene Expression Regulation / Q000502:physiology; D006498:Hepatectomy; D008099:Liver / Q000502:physiology* / Q000601:surgery*; D008115:Liver Regeneration / Q000502:physiology*; D040542:Mechanotransduction, Cellular / Q000502:physiology; D012086:Reoperation; D013552:Swine
chemical_list: D016326:Extracellular Matrix Proteins