Author(s)

Wen-Han Chen, Wen-Fang Tseng, Gen-Hwa Lin, Andrew Schreiner, Hsiao-Rong Chen, Mark M. Voigt, Chiou-Hwa Yuh, Jen-Leih Wu, Shuan Shian Huang, Jung San Huang

Auxagen Inc., St. Louis, USA.
Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, Doisy Research Center, St. Louis, USA.
Department of Pharmacology and Physiological Science, Saint Louis University School of Medicine, St. Louis, USA.
Division of Molecular and Genomic Medicine, National Health Research Institutes, Chunan.
Institute of Cellular and Organismic Biology, Academia Sinica, Taipei city.
Institute of Systems Biology and Bioinformatics, National Central University, Jhongli.

LYVE-1 (also termed CRSBP-1), a 120-kDa disulfide-linked dimeric type I membrane glycoprotein, is a specific marker for lymphatic endothelial cells (LECs) and exhibits multiple ligand (hyaluronic acid and growth factors/cytokines) binding activity in mammals. Recent studies indicate that LYVE-1/CRSBP-1 ligands (VEGF-A¹⁶⁵, PDGF-BB, oligopeptides containing the cell-surface retention sequence (CRS) motifs of VEGF-A¹⁶⁵ and PDGF-BB) induce opening of lymphatic intercellular junctions in vitro and in vivo. To determine the function of the ortholog of mammalian LYVE-1 in zebrafish, we cloned it (zLyve-1). The cloned cDNA (zLyve1) encodes a 328-amino-acid type I membrane glycoprotein. The protein and genomic structure evidence supports the notion that the cloned zLyve-1 is the ortholog of LYVE-1 in zebrafish. zLyve-1 expressed in cultured cells by transfection exhibits hyaluronic acid binding activity but lacks the growth factor binding activity seen in mammalian homologs. Knockdown of zLyve-1 levels by embryo microinjection with a specific antisense morpholino oligonucleotide (MO2) in wild-type and Tg(fli1:EGFP)-transgenic zebrafish causes defects in thoracic duct (TD) formation. Such zebrafish injected with MO2 also exhibit impaired TD flow (as determined by intramuscular injection of FITC-dextran). The phenotypes in these zebrafish injected with MO2 are reversed by co-injection with zLyve1cDNA. In situ hybridization reveals that zLyve-1 is expressed in the posterior cardinal vein (PCV). Expression of zLyve-1 at the highest level in the PCV occurs at 3 dpf which coincides with the time for TD formation in zebrafish development. These results suggest that zLyve-1 is required for TD formation. They also suggest that zLyve-1 is distinct from mammalian LYVE-1 in its role in lymphatic function.

zLyve-1; Morpholino Knockdown; Thoracic Duct; Posterior Cardinal Vein Endothelial Cells

Chen, W. , Tseng, W. , Lin, G. , Schreiner, A. , Chen, H. , M. Voigt, M. , Yuh, C. , Wu, J. , Huang, S. and Huang, J. (2013) The Ortholog of LYVE-1 Is Required for Thoracic Duct Formation in Zebrafish. CellBio, 2, 228-247. doi: 10.4236/cellbio.2013.24026.