Inter-α-inhibitor Ameliorates Endothelial Inflammation in Sepsis

Lung. 2019 Jun;197(3):361-369. doi: 10.1007/s00408-019-00228-1. Epub 2019 Apr 26.


Purpose: Vascular endothelial cells demonstrate severe injury in sepsis, and a reduction in endothelial inflammation would be beneficial. Inter-α-Inhibitor (IαI) is a family of abundant plasma proteins with anti-inflammatory properties and has been investigated in human and animal sepsis with encouraging results. We hypothesized that IαI may protect endothelia from sepsis-related inflammation.

Methods: IαI-deficient or sufficient mice were treated with endotoxin or underwent complement-induced lung injury. VCAM-1 and ICAM-1 expression was measured in blood and lung as marker of endothelial activation. Human endothelia were exposed to activated complement C5a with or without IαI. Blood from human sepsis patients was examined for VCAM-1 and ICAM-1 and levels were correlated with blood levels of IαI.

Results: IαI-deficient mice showed increased endothelial activation in endotoxin/sepsis- and complement-induced lung injury models. In vitro, levels of endothelial pro-inflammatory cytokines and cell growth factors induced by activated complement C5a were significantly decreased in the presence of IαI. This effect was associated with decreased ERK and NFκB activation. IαI levels were inversely associated with VCAM-1 and ICAM-1 levels in a human sepsis cohort.

Conclusions: IαI ameliorates endothelial inflammation and may be beneficial as a treatment of sepsis.

Keywords: Complement; Endothelial injury; Inter-alpha-inhibitor; Lipopolysaccharide; Sepsis.

Publication types

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

MeSH terms

  • Acute Lung Injury / immunology*
  • Acute Lung Injury / metabolism
  • Acute Lung Injury / pathology
  • Alpha-Globulins / deficiency
  • Alpha-Globulins / immunology*
  • Alpha-Globulins / metabolism
  • Alpha-Globulins / pharmacology
  • Animals
  • Complement C5a / immunology
  • Complement C5a / pharmacology
  • Disease Models, Animal
  • E-Selectin / immunology
  • E-Selectin / metabolism
  • Endothelial Cells / drug effects
  • Endothelial Cells / immunology*
  • Endothelial Cells / metabolism
  • Endothelium, Vascular / drug effects
  • Endothelium, Vascular / immunology*
  • Endothelium, Vascular / metabolism
  • Endotoxins / pharmacology
  • Human Umbilical Vein Endothelial Cells
  • Humans
  • In Vitro Techniques
  • Inflammation
  • Intercellular Adhesion Molecule-1 / genetics
  • Intercellular Adhesion Molecule-1 / immunology
  • Intercellular Adhesion Molecule-1 / metabolism
  • Lung / drug effects
  • Lung / immunology*
  • Lung / metabolism
  • Lung / pathology
  • MAP Kinase Signaling System
  • Mice
  • NF-kappa B / drug effects
  • NF-kappa B / immunology
  • NF-kappa B / metabolism
  • Sepsis / genetics
  • Sepsis / immunology*
  • Sepsis / metabolism
  • Vascular Cell Adhesion Molecule-1 / genetics
  • Vascular Cell Adhesion Molecule-1 / immunology
  • Vascular Cell Adhesion Molecule-1 / metabolism


  • Alpha-Globulins
  • E-Selectin
  • Endotoxins
  • NF-kappa B
  • Vascular Cell Adhesion Molecule-1
  • Intercellular Adhesion Molecule-1
  • inter-alpha-inhibitor
  • Complement C5a