p27 Nuclear localization and growth arrest caused by perlecan knockdown in human endothelial cells.
Perlecan, a secreted heparan sulfate proteoglycan, is a major component of the vascular basement membrane and participates in angiogenesis. Here, we used small interference RNA-mediated knockdown of perlecan expression to investigate the regulatory function of perlecan in the growth of human vascular endothelial cells. Basic fibroblast growth factor (bFGF)-induced ERK phosphorylation and cyclin D1 expression were unchanged by perlecan deficiency in endothelial cells; however, perlecan deficiency inhibited the Rb protein phosphorylation and DNA synthesis induced by bFGF. By contrast to cytoplasmic localization of the cyclin-dependent kinase inhibitor p27 in control endothelial cells, p27 was localized in the nucleus and its expression increased in perlecan-deficient cells, which suggests that p27 mediates inhibition of Rb phosphorylation. In addition to the well-characterized function of perlecan as a co-receptor for heparin-binding growth factors such as bFGF, our results suggest that perlecan plays an indispensible role in endothelial cell proliferation and acts through a mechanism that involves subcellular localization of p27.
Sakai
Katsuya
K
Osaka University, Suita, Osaka 565-0871, Japan.
Oka
Kiyomasa
K
Matsumoto
Kunio
K
Nakamura
Toshikazu
T
D002467:Cell Nucleus / Q000378:metabolism*; D049109:Cell Proliferation; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000378:metabolism*; D004261:DNA Replication; D004730:Endothelium, Vascular / Q000254:growth & development* / Q000378:metabolism; D055785:Gene Knockdown Techniques; D019812:Heparan Sulfate Proteoglycans / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D018919:Neovascularization, Physiologic / Q000235:genetics*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics
D019812:Heparan Sulfate Proteoglycans; D034741:RNA, Small Interfering; C071927:perlecan; D050760:Cyclin-Dependent Kinase Inhibitor p27