RIP1 kinase mediates angiogenesis by modulating macrophages in experimental neovascularization

Proc Natl Acad Sci U S A. 2019 Nov 19;116(47):23705-23713. doi: 10.1073/pnas.1908355116. Epub 2019 Nov 4.

Abstract

Inflammation plays an important role in pathological angiogenesis. Receptor-interacting protein 1 (RIP1) is highly expressed in inflammatory cells and is known to play an important role in the regulation of apoptosis, necroptosis, and inflammation; however, a comprehensive description of its role in angiogenesis remains elusive. Here, we show that RIP1 is abundantly expressed in infiltrating macrophages during angiogenesis, and genetic or pharmacological inhibition of RIP1 kinase activity using kinase-inactive RIP1K45A/K45A mice or necrostatin-1 attenuates angiogenesis in laser-induced choroidal neovascularization, Matrigel plug angiogenesis, and alkali injury-induced corneal neovascularization in mice. The inhibitory effect on angiogenesis is mediated by caspase activation through a kinase-independent function of RIP1 and RIP3. Mechanistically, infiltrating macrophages are the key target of RIP1 kinase inhibition to attenuate pathological angiogenesis. Inhibition of RIP1 kinase activity is associated with caspase activation in infiltrating macrophages and decreased expression of proangiogenic M2-like markers but not M1-like markers. Similarly, in vitro, catalytic inhibition of RIP1 down-regulates the expression of M2-like markers in interleukin-4-activated bone marrow-derived macrophages, and this effect is blocked by simultaneous caspase inhibition. Collectively, these results demonstrate a nonnecrotic function of RIP1 kinase activity and suggest that RIP1-mediated modulation of macrophage activation may be a therapeutic target of pathological angiogenesis.

Keywords: AMD; RIPK; immune; necrosis; neovascular.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biomarkers
  • Caspases / metabolism
  • Cells, Cultured
  • Collagen
  • Corneal Injuries / chemically induced
  • Corneal Injuries / etiology
  • Corneal Neovascularization / enzymology
  • Corneal Neovascularization / etiology
  • Corneal Neovascularization / pathology
  • Corneal Neovascularization / prevention & control
  • Drug Combinations
  • Enzyme Activation
  • Fibroblast Growth Factor 2 / pharmacology
  • GTPase-Activating Proteins / antagonists & inhibitors
  • GTPase-Activating Proteins / physiology*
  • Human Umbilical Vein Endothelial Cells
  • Humans
  • Imidazoles / pharmacology
  • Imidazoles / therapeutic use
  • In Situ Nick-End Labeling
  • Indoles / pharmacology
  • Indoles / therapeutic use
  • Laminin
  • Lasers / adverse effects
  • Macrophages / classification
  • Macrophages / physiology*
  • Mice
  • Mice, Inbred C57BL
  • Models, Animal
  • Neovascularization, Pathologic / enzymology*
  • Neovascularization, Pathologic / pathology
  • Oligopeptides / pharmacology
  • Proteoglycans
  • RNA, Messenger / biosynthesis
  • Receptor-Interacting Protein Serine-Threonine Kinases / deficiency
  • Receptor-Interacting Protein Serine-Threonine Kinases / physiology
  • Receptors, Vascular Endothelial Growth Factor / therapeutic use
  • Recombinant Fusion Proteins / pharmacology
  • Recombinant Fusion Proteins / therapeutic use

Substances

  • Biomarkers
  • Drug Combinations
  • GTPase-Activating Proteins
  • Imidazoles
  • Indoles
  • Laminin
  • Oligopeptides
  • Proteoglycans
  • RNA, Messenger
  • Ralbp1 protein, mouse
  • Recombinant Fusion Proteins
  • benzyloxycarbonyl-valyl-alanyl-aspartic acid
  • necrostatin-1
  • Fibroblast Growth Factor 2
  • matrigel
  • aflibercept
  • Collagen
  • Receptors, Vascular Endothelial Growth Factor
  • Receptor-Interacting Protein Serine-Threonine Kinases
  • Ripk3 protein, mouse
  • Caspases