title: The role of lipocalin-2 in liver regeneration.
abstract: OBJECTIVE
  Various immune mediators such as interleukin-6 (IL-6) have been implicated in the process of liver regeneration. Lipocalin-2 (LCN2) has been recently characterized as a prototypic immune mediator produced by various cell types being involved mainly in host defence. In addition, numerous studies have demonstrated its clinical value as a biomarker. This study aimed at defining the role of LCN2 in liver regeneration.
  
  
  METHODS
  We studied LCN2 expression in wild-type mice in a model of partial hepatectomy (PH). Furthermore, we evaluated liver regeneration after PH in LCN-deficient mice compared to littermate controls. Serum levels of LCN2 were assessed in a small group of patients undergoing hepatic resection.
  
  
  RESULTS
  LCN2 is dramatically induced in livers and sera of wild-type mice after PH, whereas liver LCN2-receptor expression was decreased. Sham operations did not affect hepatic and serum LCN2 expression. Although LCN2-deficient mice exhibited increased baseline liver expression indices, LCN2-deficient mice did not differ from wild-type mice with respect to hepatic proliferation suggesting that this molecule is not involved in hepatic repair. Only serum IL-1β levels were slightly lower in LCN(-/-) mice, whereas IL-6 serum levels did not differ between various tested animal groups. In humans undergoing hepatic resection, LCN2 levels increased significantly within 24 h following surgery.
  
  
  CONCLUSIONS
  LCN2, although massively induced in mice after PH, is not relevant in murine hepatic regeneration. Further, human studies have to define whether LCN2 could evolve as biomarker after liver surgery.
authors.affiliation: Department of Visceral, Transplant and Thoracic Surgery, Center of Operative Medicine, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Katrin
authors.initials: K
authors.lastname: Kienzl-Wagner
authors.forename: Alexander R
authors.initials: AR
authors.lastname: Moschen
authors.forename: Sabine
authors.initials: S
authors.lastname: Geiger
authors.forename: Alexandra
authors.initials: A
authors.lastname: Bichler
authors.forename: Felix
authors.initials: F
authors.lastname: Aigner
authors.forename: Gerald
authors.initials: G
authors.lastname: Brandacher
authors.forename: Johann
authors.initials: J
authors.lastname: Pratschke
authors.forename: Herbert
authors.initials: H
authors.lastname: Tilg
mesh_terms: D000209:Acute-Phase Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D000328:Adult; D000368:Aged; D000818:Animals; D015415:Biomarkers / Q000097:blood; D005260:Female; D006498:Hepatectomy / Q000379:methods; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D015850:Interleukin-6 / Q000097:blood; D000071068:Lipocalin-2; D054834:Lipocalins / Q000097:blood* / Q000235:genetics / Q000378:metabolism*; D008099:Liver / Q000378:metabolism* / Q000503:physiopathology / Q000601:surgery; D008115:Liver Regeneration; D008297:Male; D018345:Mice, Knockout; D008875:Middle Aged; D015513:Oncogene Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D011518:Proto-Oncogene Proteins / Q000097:blood*; D015398:Signal Transduction; D013997:Time Factors; D015854:Up-Regulation
chemical_list: D000209:Acute-Phase Proteins; D015415:Biomarkers; D015850:Interleukin-6; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D015513:Oncogene Proteins; D011518:Proto-Oncogene Proteins; C577686:interleukin-6, mouse; C071332:Lcn2 protein, mouse
keywords: LCN2; biomarker; hepatic proliferation; lipocalin-2; liver regeneration; partial hepatectomy