Abstract
Despite the clear major contribution of hyperlipidemia to the prevalence of cardiovascular disease in the developed world, the direct effects of lipoproteins on endothelial cells have remained obscure and are under debate. Here we report a previously uncharacterized mechanism of vessel growth modulation by lipoprotein availability. Using a genetic screen for vascular defects in zebrafish, we initially identified a mutation, stalactite (stl), in the gene encoding microsomal triglyceride transfer protein (mtp), which is involved in the biosynthesis of apolipoprotein B (ApoB)-containing lipoproteins. By manipulating lipoprotein concentrations in zebrafish, we found that ApoB negatively regulates angiogenesis and that it is the ApoB protein particle, rather than lipid moieties within ApoB-containing lipoproteins, that is primarily responsible for this effect. Mechanistically, we identified downregulation of vascular endothelial growth factor receptor 1 (VEGFR1), which acts as a decoy receptor for VEGF, as a key mediator of the endothelial response to lipoproteins, and we observed VEGFR1 downregulation in hyperlipidemic mice. These findings may open new avenues for the treatment of lipoprotein-related vascular disorders.
| Original language | English |
|---|---|
| Pages (from-to) | 967-973 |
| Number of pages | 7 |
| Journal | Nature Medicine |
| Volume | 18 |
| Issue number | 6 |
| DOIs | |
| State | Published - Jun 2012 |
Bibliographical note
Funding Information:The authors would like to thank G. Palardy, R. Miyares, N. Nevo, I. Harel, T. Berkutzki, I. Raviv, R. Oren and C. Rot for technical assistance; A. Aharoni for help with GC-MS analyses; E. Zelzer (Weizmann Institute, Israel) for providing the Ldlr-null mice, K. Tordjman (Sourasky Medical Center, Israel) for providing the ApoE-null mice, S. Schulte-Merker (Hubrecht Institute) for providing the vegfr1 plasmid and the Tg(flt1:YFP)hu4624 transgenic line; J. Berliner (University of California Los Angeles, California) for providing human aortic endothelial cells (HAECs); D. Haratz, I. Groskop and A. Shaish for advice regarding lipid analyses; A. Harmelin and N. Stettner for animal care; and I.B. Dawid, E. Tzahor, A. Gross, B. Shilo and J. Torres-Vazquez for critical reading of the manuscript. The authors are grateful to all the members of the Yaniv and Weinstein labs for discussion, technical assistance and continuous support. This work was supported in part by Israel Science Foundation 748/2009 (to K.Y.), Marie Curie Actions-International Reintegration grants FP7-PEOPLE-2009-RG 256393 (to K.Y.), the Yeda-Sela Center (to K.Y.), the Israel Cancer Research Foundation Postdoctoral Fellowship (to I.A.-D.), US National Institutes of Health (NIH) RO1CA126935 (to M.L.I.-A.), NIH T32HL069766 (training grant for T.T.C. and C.M.W.) and NIH HL049373 (to G.S.S.). S.A.F. is funded by the NIH (R56DK093399 and R01GM063904), the Carnegie Institution for Science endowment and the G. Harold and Leila Y. Mathers Charitable Foundation. B.M.W. is supported by the intramural program of the National Institute of Child Health and Human Development, NIH, and by the Foundation Leducq.
