PUBLICATION

AIBP Limits Angiogenesis Through γ-Secretase-Mediated Upregulation of Notch Signaling

Authors
Meng, S., Mao, R., Gu, Q., Araujo-Gutierrez, R., Kumar, S., Yan, Q., Almazan, F., Youker, K.A., Fu, Y., Pownall, H.J., Cooke, J.P., Miller, Y.I., Fang, L.
ID
ZDB-PUB-170323-14
Date
2017
Source
Circulation research   120(11): 1727-1739 (Journal)
Registered Authors
Fang, Longhou, Gu, Qilin, Miller, Yury
Keywords
AIBP, Notch signaling, angiogenesis, cholesterol, cholesterol efflux, lipid rafts, lipids and lipoprotein metabolism
MeSH Terms
  • Amyloid Precursor Protein Secretases/physiology*
  • Animals
  • Carrier Proteins/biosynthesis*
  • Hindlimb/blood supply
  • Hindlimb/metabolism
  • Hindlimb/pathology
  • Humans
  • Ischemia/metabolism
  • Ischemia/pathology
  • Mice
  • Mice, Knockout
  • Neovascularization, Physiologic/physiology*
  • Phosphoproteins/biosynthesis*
  • Receptors, Notch/biosynthesis*
  • Retina/metabolism
  • Retina/pathology
  • Signal Transduction/physiology*
  • Up-Regulation/physiology*
  • Zebrafish
PubMed
28325782 Full text @ Circ. Res.
Abstract
Angiogenesis improves perfusion to the ischemic tissue after acute vascular obstruction. Angiogenesis in pathophysiological settings reactivates signaling pathways involved in developmental angiogenesis. We showed previously that AIBP (apolipoprotein A-I [apoA-I]-binding protein)-regulated cholesterol efflux in endothelial cells controls zebra fish embryonic angiogenesis.
This study is to determine whether loss of AIBP affects angiogenesis in mice during development and under pathological conditions and to explore the underlying molecular mechanism.
In this article, we report the generation of AIBP knockout (Apoa1bp-/-) mice, which are characterized of accelerated postnatal retinal angiogenesis. Mechanistically, AIBP triggered relocalization of γ-secretase from lipid rafts to nonlipid rafts where it cleaved Notch. Consistently, AIBP treatment enhanced DLL4 (delta-like ligand 4)-stimulated Notch activation in human retinal endothelial cells. Increasing high-density lipoprotein levels in Apoa1bp-/- mice by crossing them with apoA-I transgenic mice rescued Notch activation and corrected dysregulated retinal angiogenesis. Notably, the retinal vessels in Apoa1bp-/- mice manifested normal pericyte coverage and vascular integrity. Similarly, in the subcutaneous Matrigel plug assay, which mimics ischemic/inflammatory neovascularization, angiogenesis was dramatically upregulated in Apoa1bp-/- mice and associated with a profound inhibition of Notch activation and reduced expression of downstream targets. Furthermore, loss of AIBP increased vascular density and facilitated the recovery of blood vessel perfusion function in a murine hindlimb ischemia model. In addition, AIBP expression was significantly increased in human patients with ischemic cardiomyopathy.
Our data reveal a novel mechanistic connection between AIBP-mediated cholesterol metabolism and Notch signaling, implicating AIBP as a possible druggable target to modulate angiogenesis under pathological conditions.
Genes / Markers
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Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
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Mapping