Endothelial p110γPI3K Mediates Endothelial Regeneration and Vascular Repair After Inflammatory Vascular Injury

Circulation. 2016 Mar 15;133(11):1093-103. doi: 10.1161/CIRCULATIONAHA.115.020918. Epub 2016 Feb 2.

Abstract

Background: The integrity of endothelial monolayer is a sine qua non for vascular homeostasis and maintenance of tissue-fluid balance. However, little is known about the signaling pathways regulating regeneration of the endothelial barrier after inflammatory vascular injury.

Methods and results: Using genetic and pharmacological approaches, we demonstrated that endothelial regeneration selectively requires activation of p110γPI3K signaling, which thereby mediates the expression of the endothelial reparative transcription factor Forkhead box M1 (FoxM1). We observed that FoxM1 induction in the pulmonary vasculature was inhibited in mice treated with a p110γ-selective inhibitor and in Pik3cg(-/-) mice after lipopolysaccharide challenge. Pik3cg(-/-) mice exhibited persistent lung inflammation induced by sepsis and sustained increase in vascular permeability. Restoration of expression of either p110γ or FoxM1 in pulmonary endothelial cells of Pik3cg(-/-) mice restored endothelial regeneration and normalized the defective vascular repair program. We also observed diminished expression of p110γ in pulmonary vascular endothelial cells of patients with acute respiratory distress syndrome, suggesting that impaired p110γ-FoxM1 vascular repair signaling pathway is a critical factor in persistent leaky lung microvessels and edema formation in the disease.

Conclusions: We identify p110γ as the critical mediator of endothelial regeneration and vascular repair after sepsis-induced inflammatory injury. Thus, activation of p110γ-FoxM1 endothelial regeneration may represent a novel strategy for the treatment of inflammatory vascular diseases.

Keywords: endothelial regeneration; endothelium, vascular; inflammation; vascular diseases; vascular repair.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Androstadienes / pharmacology
  • Animals
  • Capillary Leak Syndrome / pathology
  • Capillary Leak Syndrome / physiopathology
  • Capillary Permeability / physiology
  • Cells, Cultured
  • Class Ib Phosphatidylinositol 3-Kinase / deficiency
  • Class Ib Phosphatidylinositol 3-Kinase / genetics
  • Class Ib Phosphatidylinositol 3-Kinase / physiology*
  • Endothelium, Vascular / enzymology*
  • Endothelium, Vascular / injuries
  • Endothelium, Vascular / physiology
  • Enzyme Activation / drug effects
  • Enzyme Induction / drug effects
  • Forkhead Box Protein M1
  • Forkhead Transcription Factors / biosynthesis
  • Forkhead Transcription Factors / deficiency
  • Forkhead Transcription Factors / genetics
  • Forkhead Transcription Factors / physiology
  • Furans / pharmacology
  • Humans
  • Lung / blood supply
  • Mice
  • Mice, Knockout
  • Microvessels / metabolism
  • Microvessels / physiopathology
  • Neutrophils / physiology
  • Phosphoinositide-3 Kinase Inhibitors
  • Protein Isoforms / antagonists & inhibitors
  • Protein Isoforms / physiology
  • Pulmonary Edema / pathology
  • Pulmonary Edema / physiopathology
  • Pyridines / pharmacology
  • Pyrimidines / pharmacology
  • Quinoxalines / pharmacology
  • Recombinant Fusion Proteins / metabolism
  • Regeneration / physiology*
  • Respiratory Distress Syndrome / enzymology*
  • Respiratory Distress Syndrome / pathology
  • Sepsis / pathology
  • Sepsis / physiopathology
  • Signal Transduction / drug effects
  • Thiazolidinediones / pharmacology
  • Transfection
  • Wortmannin

Substances

  • 5-quinoxalin-6-ylmethylenethiazolidine-2,4-dione
  • Androstadienes
  • Forkhead Box Protein M1
  • Forkhead Transcription Factors
  • Foxm1 protein, mouse
  • Furans
  • PI103
  • Phosphoinositide-3 Kinase Inhibitors
  • Protein Isoforms
  • Pyridines
  • Pyrimidines
  • Quinoxalines
  • Recombinant Fusion Proteins
  • Thiazolidinediones
  • Class Ib Phosphatidylinositol 3-Kinase
  • PIK3CG protein, human
  • Pik3cg protein, mouse
  • Wortmannin