Apelin is a novel angiogenic factor in retinal endothelial cells

• Published in: Biochemical and biophysical research communications Vol. 325; no. 2; pp. 395 - 400
• Main Authors: Kasai, Atsushi, Shintani, Norihito, Oda, Maki, Kakuda, Michiya, Hashimoto, Hitoshi, Matsuda, Toshio, Hinuma, Shuji, Baba, Akemichi
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 10.12.2004
• Subjects: Adipokines; Angiogenesis; Angiogenesis Modulating Agents - metabolism; Angiogenesis Modulating Agents - pharmacology; Angiogenic Proteins - pharmacology; Angiogenic Proteins - physiology; Animals; Apelin; APJ; Capillaries - growth & development; Capillaries - ultrastructure; Carrier Proteins - pharmacology; Carrier Proteins - physiology; Cell Movement - drug effects; Cell Proliferation - drug effects; Endothelium; Endothelium, Vascular - cytology; Endothelium, Vascular - drug effects; Endothelium, Vascular - metabolism; Hemoglobins - analysis; Humans; Intercellular Signaling Peptides and Proteins; Mice; Neovascularization, Physiologic - drug effects; Orphan G-protein-coupled receptor; Recombinant Proteins - genetics; Recombinant Proteins - metabolism; Recombinant Proteins - pharmacology; Retina; Retina - cytology; Retina - drug effects; Retina - metabolism; RF/6A; Umbilical Veins - cytology; Vascular Endothelial Growth Factor A - pharmacology; VEGF; Angiogenesis; RF/6A; Orphan G-protein-coupled receptor; VEGF; Retina; APJ; Apelin; Endothelium
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2004.10.042

There has been much focus recently on the possible functions of apelin, an endogenous ligand for the orphan G-protein-coupled receptor APJ, in cardiovascular and central nervous systems. We report a new function of apelin as a novel angiogenic factor in retinal endothelial cells. The retinal endothelial cell line RF/6A highly expressed both apelin and APJ transcripts, while human umbilical venous endothelial cells (HUVECs) only expressed apelin mRNA. In accordance with these observations, apelin at concentrations of 1 pM–1 μM significantly enhanced migration, proliferation, and capillary-like tube formation of RF/6A cells, but not those of HUVECs, whereas VEGF stimulates those parameters of both cell types. In vivo Matrigel plug assay for angiogenesis, the inclusion of 1 nM apelin in the Matrigel resulted in clear capillary-like formations with an increase of hemoglobin content in the plug. This is the first report showing that apelin is an angiogenic factor in retinal endothelial cells.