ABSTRACT
In this review, we present the recent progress on film metrology focused on the advanced and novel technologies during the last two decades. This review consists of various technologies and their measurement schemes to provide the inspiration for understanding each of the measurement principles and applications. In the technology and analysis section, several optical techniques used in film metrology are introduced and described with their benefits and limitations. The temporal, spatial and snapshot measurement schemes of optical film metrology are introduced in the measurement scheme section, and finally, the prospect on optical film metrology will be provided and discussed with the technology trend.
ABSTRACT
Adipocyte-derived leucine aminopeptidase (A-LAP) is a novel member of the M1 family of zinc metallopeptidases, which has been reported to play a crucial role in angiogenesis. In the present study, we conducted a target-based screening of natural products and synthetic chemical libraries using the purified enzyme to search novel inhibitors of A-LAP. Amongst several hits isolated, a natural product purpurin was identified as one of the most potent inhibitors of A-LAP from the screening. In vitro enzymatic analyses demonstrated that purpurin inhibited A-LAP activity in a non-competitive manner with a Ki value of 20 M. In addition, purpurin showed a strong selectivity toward A-LAP versus another member of M1 family of zinc metallopeptidase, aminopeptidase N (APN). In angiogenesis assays, purpurin inhibited the vascular endothelial growth factor (VEGF)-induced invasion and tube formation of human umbilical vein endothelial cells (HUVEC). Moreover, purpurin inhibited in vivo angiogenesis in zebrafish embryo without toxicity. These data demonstrate that purpurin is a novel specific inhibitor of A-LAP and could be developed as a new anti-angiogenic agent.
Subject(s)
Adipocytes/enzymology , Anthraquinones/pharmacology , Endothelial Cells/physiology , Leucyl Aminopeptidase/antagonists & inhibitors , Leucyl Aminopeptidase/metabolism , Neovascularization, Physiologic/physiology , Zebrafish/physiology , Animals , Cell Survival/drug effects , Cells, Cultured , Endothelial Cells/drug effects , Enzyme Inhibitors/pharmacology , Humans , Models, Animal , Neovascularization, Physiologic/drug effectsABSTRACT
Sphingosine-1-phosphate (S1P) plays an important role in angiogenesis by stimulating DNA synthesis, chemotactic motility, and early blood vessel formation. Accordingly, the S1P signaling pathway is an attractive target for novel anti-angiogenic therapeutics. Here, we describe a small synthetic derivative of S1P that acts as an anti-angiogenic agent. We found that the S1P derivative NHOBTD [N-((2S,3R)-3-hydroxy-1-morpholino-4-(3-octylphenyl)butan-2-yl)tetradecanamide] suppressed S1P-induced invasion and tube formation by human umbilical vein endothelial cells. NHOBTD also suppressed S1P signaling, as seen by destabilization of hypoxia inducible factor-1 alpha (HIF-1α) and secretion of VEGF, a transcriptional target of HIF-1α. Moreover, NHOBTD profoundly blocked endogenous neovascularization of the chick embryo chorioallantoic membrane, without rupturing any existing vessels. Together, these results demonstrate that NHOBTD is a new anti-angiogenic molecule that is capable of perturbing S1P signaling, and provides the basis for developing new anti-angiogenic drugs.
