Sinusoid development and morphogenesis may be stimulated by VEGF-Flk-1 signaling during fetal mouse liver development.
Early morphogenesis of hepatic sinusoids was histochemically and experimentally analyzed, and the importance of VEGF-Flk-1 signaling in the vascular development was examined during murine liver organogenesis. FITC-gelatin injection experiments into young murine fetuses demonstrated that all primitive sinusoidal structures were confluent with portal and central veins, suggesting that hepatic vessel development may occur via angiogenesis. At 12.5-14.5 days of gestation, VEGF receptors designated Flk-1, especially their mature form, were highly expressed in endothelial cells of primitive sinusoidal structures and highly phosphorylated on their tyrosine residues. At the same time, VEGF was also detected in hepatoblasts/hepatocytes, hemopoietic cells, and megakaryocytes of the whole liver parenchyma. Furthermore, the addition of VEGF to E12.5 liver cell cultures significantly induced the growth and branching morphogenesis of sinusoidal endothelial cells. Therefore, VEGF-Flk-1 signaling may play an important role in the growth and morphogenesis of primitive sinusoids during fetal liver development.
Sugiyama
Yoshinori
Y
Department of Biology, Faculty of Science, Shizuoka University, Shizuoka City, Japan.
Takabe
Yurie
Y
Nakakura
Takashi
T
Tanaka
Shigeyasu
S
Koike
Toru
T
Shiojiri
Nobuyoshi
N
D000818:Animals; D018929:Cell Culture Techniques; D049109:Cell Proliferation; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000502:physiology; D016650:Fluorescein-5-isothiocyanate; D007150:Immunohistochemistry; D008099:Liver / Q000098:blood supply / Q000196:embryology* / Q000378:metabolism; D051379:Mice; D008809:Mice, Inbred C3H; D038081:Organogenesis; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism*
D042461:Vascular Endothelial Growth Factor A; D040301:Vascular Endothelial Growth Factor Receptor-2; D016650:Fluorescein-5-isothiocyanate