title: Essential roles of sphingosine 1-phosphate receptor types 1 and 3 in human hepatic stellate cells motility and activation.
abstract: The biological roles of sphingosine 1-phosphate (S1P) and S1P receptors (S1PRs) have been broadly investigated. However, at present pathophysiological roles of S1P/S1PRs axis in liver fibrosis are not well defined. Here, we investigated the functions of S1P/S1PRs axis in human hepatic stellate cells (HSC) line, LX-2 cells. We found that S1PR types 1, 2 and 3 (S1PR1-3) are clearly detected in LX-2 cells, as determined by RT-PCR, Western blot and immunocytochemistry analysis. S1P exerted a powerful migratory action on LX-2 cells, as determined in Boyden chambers, and stimulated fibrogenic activity of LX-2 cells, as demonstrated by increase of expression of smooth muscle α-actin, procollagen α1(I) and α1(III) and total hydroxyproline content. Moreover, the effects of S1P were mimicked by S1PR1 agonist SEW2871, and abrogated by W146 (S1PR1 antagonist) and/or silencing S1PR1, three expression with small interfering RNA, suggesting the main roles of S1PR1 and 3. However, studies with S1PR2 antagonist JTE-013 and silencing S1PR2 expression indicated that S1PR2 negatively regulated S1P-induced cell migration. Interestingly, exogenously added S1P induced significant up-regulation of sphingosine kinase-1 and the synthesis of additional S1P, and expression of S1PR1,3, but not S1PR2. In conclusion, our data have identified an additional function regulated by S1P/S1PR1,3 axis involving migration and fibrogenic activation of HSCs. These results suggest that selective modulation of S1PR activity may represent a new antifibrotic strategy.
authors.affiliation: Department of Cell Biology, Municipal Laboratory for Liver Protection and Regulation of Regeneration, Capital Medical University, Beijing, China.
authors.forename: Xihong
authors.initials: X
authors.lastname: Liu
authors.forename: Shi
authors.initials: S
authors.lastname: Yue
authors.forename: Changyong
authors.initials: C
authors.lastname: Li
authors.forename: Lin
authors.initials: L
authors.lastname: Yang
authors.forename: Hong
authors.initials: H
authors.lastname: You
authors.forename: Liying
authors.initials: L
authors.lastname: Li
mesh_terms: D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects; D020868:Gene Silencing / Q000187:drug effects; D055166:Hepatic Stellate Cells / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D006801:Humans; D008246:Lysophospholipids / Q000494:pharmacology; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000378:metabolism; D049349:Receptors, Lysosphingolipid / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D013110:Sphingosine / Q000031:analogs & derivatives / Q000494:pharmacology; D000081025:Sphingosine-1-Phosphate Receptors; D000099157:Sphingosine Kinase
chemical_list: D008246:Lysophospholipids; D017853:Phosphotransferases (Alcohol Group Acceptor); D049349:Receptors, Lysosphingolipid; D013110:Sphingosine; D000081025:Sphingosine-1-Phosphate Receptors; D000099157:Sphingosine Kinase; C477362:S1PR1 protein, human; C477522:S1PR2 protein, human; C060506:sphingosine 1-phosphate