Genes Cells. 2006 Jul;11(7):719-29Puromycin insensitive
leucyl-specific aminopeptidase (PILSAP) is required for the
development of vascular as well as hematopoietic system in
embryoid bodies.
Abe M, Sato Y.
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
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.
PMID: 16824192 |
