title: The profile of platelet α-granule released molecules affects postoperative liver regeneration.
abstract: Platelets promote liver regeneration through site-specific serotonin release from dense granules, triggering proliferative signaling in hepatocytes. However, the effects of factors derived from platelet α-granules on liver regeneration are unclear, because α-granules contain bioactive molecules with opposing functions. Because α-granule molecules are stored in separate compartments, it has been suggested that platelets selectively release their α-granule content dependent on the environmental stimulus. Therefore, we investigated the pattern of circulating α-granule molecules during liver regeneration in 157 patients undergoing partial hepatectomy. We measured plasma levels of α-granule-derived factors in the liver vein at the end of liver resection, as well as on the first postoperative day. We observed a rapid accumulation of platelets within the liver after induction of liver regeneration. Platelet count and P-selectin (a ubiquitous cargo of α-granules) were not associated with postoperative liver dysfunction. However, low plasma levels of vascular endothelial growth factor (VEGF), but high levels of thrombospondin 1 (TSP-1), predicted liver dysfunction after resection. Patients with an unfavorable postoperative α-granule release profile (high TSP-1/low VEGF) showed substantially worse postoperative clinical outcomes. The unfavorable postoperative α-granule release profile was associated with increased postoperative portal venous pressure and von Willebrand factor antigen levels as a marker for intrahepatic endothelial dysfunction.
  
  
  CONCLUSIONS
  The postoperative profile of circulating platelet-derived factors correlates with the ability of the remnant liver to regenerate. Portal venous pressure and intrahepatic endothelial dysfunction might account for the selective granule release profile. Selective modulation of platelet α-granule release in patients may represent an attractive target for therapeutic interventions to improve liver regeneration and clinical outcomes after partial hepatectomy.
authors.affiliation: Department of Surgery, Medical University of Vienna, General Hospital, Vienna, Austria.
authors.forename: Patrick
authors.initials: P
authors.lastname: Starlinger
authors.affiliation: Department of Surgery, Medical University of Vienna, General Hospital, Vienna, Austria.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Haegele
authors.affiliation: Department of Surgery, Medical University of Vienna, General Hospital, Vienna, Austria.
authors.forename: Florian
authors.initials: F
authors.lastname: Offensperger
authors.affiliation: Department of Surgery I, Rudolfstiftung Hospital, Vienna, Austria.
authors.forename: Lukas
authors.initials: L
authors.lastname: Oehlberger
authors.affiliation: Department of Surgery, Medical University of Vienna, General Hospital, Vienna, Austria.
authors.forename: David
authors.initials: D
authors.lastname: Pereyra
authors.affiliation: Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria.
authors.forename: Julia B
authors.initials: JB
authors.lastname: Kral
authors.affiliation: Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria.
authors.forename: Waltraud C
authors.initials: WC
authors.lastname: Schrottmaier
authors.affiliation: Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria.
authors.forename: Sigrun
authors.initials: S
authors.lastname: Badrnya
authors.affiliation: Department of Gastroenterology and Hepatology, Medical University of Vienna, General Hospital, Vienna, Austria.
authors.forename: Thomas
authors.initials: T
authors.lastname: Reiberger
authors.affiliation: Department of Gastroenterology and Hepatology, Medical University of Vienna, General Hospital, Vienna, Austria.
authors.forename: Arnulf
authors.initials: A
authors.lastname: Ferlitsch
authors.affiliation: Department of Pathology, Medical University of Vienna, General Hospital, Vienna, Austria.
authors.forename: Judith
authors.initials: J
authors.lastname: Stift
authors.affiliation: Department of Anesthesiology, Medical University of Vienna, General Hospital, Vienna, Austria.
authors.forename: Florian
authors.initials: F
authors.lastname: Luf
authors.affiliation: Department of Surgery, Medical University of Vienna, General Hospital, Vienna, Austria.
authors.forename: Christine
authors.initials: C
authors.lastname: Brostjan
authors.affiliation: Department of Surgery I, Rudolfstiftung Hospital, Vienna, Austria.
authors.forename: Thomas
authors.initials: T
authors.lastname: Gruenberger
authors.affiliation: Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria.
authors.forename: Alice
authors.initials: A
authors.lastname: Assinger
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001792:Blood Platelets / Q000502:physiology*; D003594:Cytoplasmic Granules / Q000502:physiology*; D005260:Female; D006498:Hepatectomy; D006801:Humans; D008115:Liver Regeneration; D008297:Male; D008875:Middle Aged; D019700:Thrombospondin 1 / Q000502:physiology*; D042461:Vascular Endothelial Growth Factor A / Q000502:physiology*
chemical_list: D019700:Thrombospondin 1; D042461:Vascular Endothelial Growth Factor A