title: Intracellular reactive oxygen species are required for directional migration of resident and bone marrow-derived hepatic pro-fibrogenic cells.
abstract: OBJECTIVE
  Liver fibrogenesis is sustained by myofibroblast-like cells originating from hepatic stellate cells (HSC/MFs), portal fibroblasts or bone marrow-derived cells, including mesenchymal stem cells (MSCs). Herein, we investigated the mechanistic role of intracellular generation of reactive oxygen species (ROS) and redox-sensitive signal transduction pathways in mediating chemotaxis, a critical profibrogenic response for human HSC/MFs and for MSC potentially engrafting chronically injured liver.
  
  
  METHODS
  Intracellular generation of ROS and signal transduction pathways were evaluated by integrating morphological and molecular biology techniques. Chemokinesis and chemotaxis were evaluated by wound healing assay and modified Boyden's chamber assay, respectively. Additional in vivo evidence was obtained in human specimens from HCV-related cirrhosis.
  
  
  RESULTS
  Human MSCs and HSC/MFs migrate in response to a panel of polypeptide chemoattractants and extracellularly generated superoxide anion. All polypeptides induced a NADPH-oxidase-dependent intracellular rise in ROS, resulting in activation of ERK1/2 and JNK1/2. Moreover, menadione or 2,3-dimethoxy-1,4-naphthoquinone, which generate intracellular superoxide anion or hydrogen peroxide, respectively, induced ERK1/2 and JNK1/2 activation and migration. JNK1 activation was predominant for migration as shown by specific silencing. Finally, activation of ERK1/2 and JNK1/2 was found in extracts obtained from HSC/MFs during the course of an oxidative stress-mediated model of liver injury and phosphorylated JNK1/2 isoforms were detected in α-smooth muscle actin-positive myofibroblasts lining fibrotic septa in human cirrhotic livers.
  
  
  CONCLUSIONS
  Intracellular generation of ROS, through activation of specific signaling pathways, is a critical event for directional migration of HSC/MFs and MSCs.
authors.affiliation: Dip. Medicina e Oncologia Sperimentale - Centro Interuniversitario di Fisiopatologia Epatica, Italy.
authors.forename: Erica
authors.initials: E
authors.lastname: Novo
authors.forename: Chiara
authors.initials: C
authors.lastname: Busletta
authors.forename: Lorenzo Valfrè di
authors.initials: LV
authors.lastname: Bonzo
authors.forename: Davide
authors.initials: D
authors.lastname: Povero
authors.forename: Claudia
authors.initials: C
authors.lastname: Paternostro
authors.forename: Katia
authors.initials: K
authors.lastname: Mareschi
authors.forename: Ivana
authors.initials: I
authors.lastname: Ferrero
authors.forename: Ezio
authors.initials: E
authors.lastname: David
authors.forename: Cristiana
authors.initials: C
authors.lastname: Bertolani
authors.forename: Alessandra
authors.initials: A
authors.lastname: Caligiuri
authors.forename: Stefania
authors.initials: S
authors.lastname: Cannito
authors.forename: Elena
authors.initials: E
authors.lastname: Tamagno
authors.forename: Alessandra
authors.initials: A
authors.lastname: Compagnone
authors.forename: Sebastiano
authors.initials: S
authors.lastname: Colombatto
authors.forename: Fabio
authors.initials: F
authors.lastname: Marra
authors.forename: Franca
authors.initials: F
authors.lastname: Fagioli
authors.forename: Massimo
authors.initials: M
authors.lastname: Pinzani
authors.forename: Maurizio
authors.initials: M
authors.lastname: Parola
mesh_terms: D001854:Bone Marrow Cells / Q000166:cytology* / Q000378:metabolism; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D002630:Chemotactic Factors / Q000494:pharmacology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D055166:Hepatic Stellate Cells / Q000166:cytology* / Q000378:metabolism; D019698:Hepatitis C, Chronic / Q000378:metabolism / Q000473:pathology; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000494:pharmacology; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D008103:Liver Cirrhosis / Q000378:metabolism* / Q000473:pathology*; D020935:MAP Kinase Signaling System / Q000502:physiology; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*
chemical_list: D002630:Chemotactic Factors; D036341:Intercellular Signaling Peptides and Proteins; D017382:Reactive Oxygen Species; D048049:Extracellular Signal-Regulated MAP Kinases; D048031:JNK Mitogen-Activated Protein Kinases