title: Exosome Adherence and Internalization by Hepatic Stellate Cells Triggers Sphingosine 1-Phosphate-dependent Migration.
abstract: Exosomes are cell-derived extracellular vesicles thought to promote intercellular communication by delivering specific content to target cells. The aim of this study was to determine whether endothelial cell (EC)-derived exosomes could regulate the phenotype of hepatic stellate cells (HSCs). Initial microarray studies showed that fibroblast growth factor 2 induced a 2.4-fold increase in mRNA levels of sphingosine kinase 1 (SK1). Exosomes derived from an SK1-overexpressing EC line increased HSC migration 3.2-fold. Migration was not conferred by the dominant negative SK1 exosome. Incubation of HSCs with exosomes was also associated with an 8.3-fold increase in phosphorylation of AKT and 2.5-fold increase in migration. Exosomes were found to express the matrix protein and integrin ligand fibronectin (FN) by Western blot analysis and transmission electron microscopy. Blockade of the FN-integrin interaction with a CD29 neutralizing antibody or the RGD peptide attenuated exosome-induced HSC AKT phosphorylation and migration. Inhibition of endocytosis with transfection of dynamin siRNA, the dominant negative dynamin GTPase construct Dyn2K44A, or the pharmacological inhibitor Dynasore significantly attenuated exosome-induced AKT phosphorylation. SK1 levels were increased in serum exosomes derived from mice with experimental liver fibrosis, and SK1 mRNA levels were up-regulated 2.5-fold in human liver cirrhosis patient samples. Finally, S1PR2 inhibition protected mice from CCl4-induced liver fibrosis. Therefore, EC-derived SK1-containing exosomes regulate HSC signaling and migration through FN-integrin-dependent exosome adherence and dynamin-dependent exosome internalization. These findings advance our understanding of EC/HSC cross-talk and identify exosomes as a potential target to attenuate pathobiology signals.
authors.affiliation: From the Departments of Molecular Pharmacology and Experimental Therapeutics and.
authors.forename: Ruisi
authors.initials: R
authors.lastname: Wang
authors.affiliation: Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota 55902.
authors.forename: Qian
authors.initials: Q
authors.lastname: Ding
authors.affiliation: Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota 55902.
authors.forename: Usman
authors.initials: U
authors.lastname: Yaqoob
authors.affiliation: Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota 55902.
authors.forename: Thiago M
authors.initials: TM
authors.lastname: de Assuncao
authors.affiliation: Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota 55902.
authors.forename: Vikas K
authors.initials: VK
authors.lastname: Verma
authors.affiliation: Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota 55902.
authors.forename: Petra
authors.initials: P
authors.lastname: Hirsova
authors.affiliation: Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota 55902.
authors.forename: Sheng
authors.initials: S
authors.lastname: Cao
authors.affiliation: Biochemistry and Molecular Biology and.
authors.forename: Debabrata
authors.initials: D
authors.lastname: Mukhopadhyay
authors.affiliation: Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota 55902.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Huebert
authors.affiliation: Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota 55902 shah.vijay@mayo.edu.
authors.forename: Vijay H
authors.initials: VH
authors.lastname: Shah
mesh_terms: D000818:Animals; D002465:Cell Movement; D055354:Exosomes / Q000378:metabolism*; D055166:Hepatic Stellate Cells / Q000166:cytology* / Q000378:metabolism; D006801:Humans; D016023:Integrins / Q000235:genetics / Q000378:metabolism; D008103:Liver Cirrhosis / Q000235:genetics / Q000378:metabolism* / Q000503:physiopathology; D008246:Lysophospholipids / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D049349:Receptors, Lysosphingolipid / Q000235:genetics / Q000378:metabolism; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000378:metabolism; D000081025:Sphingosine-1-Phosphate Receptors
chemical_list: D016023:Integrins; D008246:Lysophospholipids; D049349:Receptors, Lysosphingolipid; D000081025:Sphingosine-1-Phosphate Receptors; C533955:sphingosine-1-phosphate receptor-2, mouse; C060506:sphingosine 1-phosphate; D013110:Sphingosine
keywords: adhesion; endocytosis; exosome (vesicle); fibrosis; hepatic stellate cell (HSC); liver