Puromycin insensitive leucyl-specific aminopeptidase (PILSAP) is required for the development of vascular as well as hematopoietic system in embryoid bodies.
We have shown that puromycin insensitive leucyl-specific aminopeptidase (PILSAP) is required for regulation of angiogenesis. However, it remains unclear whether PILSAP plays a role in endothelial cell (EC) differentiation. We examined the role of PILSAP by using an embryoid bodies (EBs) culture system. Fms-like tyrosine kinase-1 (Flk-1) showed two expression peaks on days 4 and 10 of culture. These two peaks represent populations of mesodermal precursors and mature ECs, respectively. Endothelial markers such as VE-cadherin, CD34, CD31 and Tie2 followed the first peak of Flk-1. Interestingly, the expression of PILSAP showed a pattern similar to that of Flk-1. ES cells transfected with mutant PILSAP (mtPILSAP) cDNA of a dominant negative activity organized less vascular structure and showed decreased levels of vascular lineage markers. The similar results were obtained in EBs treated with leucinethiol, a specific inhibitor of leucine aminopeptidase or siRNA for PILSAP. However, Flk-1 expression was unaffected on day 4. The expression of markers for hematopoietic lineage and muscle cells in mtPILSAP-EBs was also reduced. These results suggest that although PILSAP may not function in the initial generation of Flk-1 positive mesodermal precursors, it dose play a role in growth of vascular, hematopoietic, and muscular lineage population from those precursors.
Abe
Mayumi
M
Department of Vascular Biology, Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryo-machi, Aoba-ku, Sendai, 980-8575, Japan. mayudnp@tmd.ac.jp
Sato
Yasufumi
Y
D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D004622:Embryo, Mammalian / Q000098:blood supply* / Q000166:cytology*; D042783:Endothelial Cells / Q000166:cytology / Q000201:enzymology; D006413:Hematopoietic System / Q000196:embryology*; D007150:Immunohistochemistry; D007931:Leucyl Aminopeptidase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008648:Mesoderm / Q000166:cytology / Q000201:enzymology; D051379:Mice; D018613:Microscopy, Confocal; D018919:Neovascularization, Physiologic / Q000502:physiology; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000096:biosynthesis
D040281:Vascular Endothelial Growth Factor Receptor-1; D007931:Leucyl Aminopeptidase; C456799:puromycin-insensitive leucyl-specific aminopeptidase