Macrophage Migration Inhibitory Factor-Induced Autophagy Contributes to Thrombin-Triggered Endothelial Hyperpermeability in Sepsis

Shock. 2018 Jul;50(1):103-111. doi: 10.1097/SHK.0000000000000976.

Abstract

Vascular leakage contributes to the high morbidity and mortality associated with sepsis. Exposure of the endothelium to inflammatory mediators, such as thrombin and cytokines, during sepsis leads to hyperpermeability. We recently observed that autophagy, a cellular process for protein turnover, is involved in macrophage migration inhibitory factor (MIF)-induced endothelial hyperpermeability. Even though it is known that thrombin induces endothelial cells to secrete MIF and to increase vascular permeability, the possible role of autophagy in this process is unknown. In this study, we proposed and tested the hypothesis that MIF-induced autophagy plays an important role in thrombin-induced endothelial hyperpermeability. We evaluated the effects of thrombin on endothelial permeability, autophagy induction, and MIF secretion in vitro using the human microvascular endothelial cell line-1 and human umbilical vein endothelial cells. Several mechanisms/read outs of endothelial permeability and autophagy formation were examined. We observed that blocking autophagy attenuated thrombin-induced endothelial hyperpermeability. Furthermore, thrombin-induced MIF secretion was involved in this process because MIF inhibition reduced thrombin-induced autophagy and hyperpermeability. Finally, we showed that blocking MIF or autophagy effectively alleviated vascular leakage and mortality in endotoxemic mice. Thus, MIF-induced autophagy may represent a common mechanism causing vascular leakage in sepsis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autophagy / drug effects*
  • Capillary Permeability / drug effects
  • Cell Line
  • Endothelial Cells / drug effects
  • Endothelial Cells / metabolism
  • Enzyme-Linked Immunosorbent Assay
  • Human Umbilical Vein Endothelial Cells
  • Humans
  • Intramolecular Oxidoreductases / metabolism
  • Macrophage Migration-Inhibitory Factors / metabolism
  • Macrophage Migration-Inhibitory Factors / pharmacology*
  • Mice
  • Mice, Inbred BALB C
  • Sepsis / metabolism*
  • Thrombin / pharmacology

Substances

  • Macrophage Migration-Inhibitory Factors
  • Thrombin
  • Intramolecular Oxidoreductases
  • MIF protein, human