Enhanced adhesion of polymorphonuclear leukocytes to anoxic cultured vascular endothelium

J M Budd1, S J Kirtland, H Baum

  • 1Roche Products Ltd., Welwyn Garden City, Hertfordshire, U.K.

Cellular Signalling
|January 1, 1990
PubMed

Insights

Anoxia increases human polymorphonuclear leukocyte (PMN) adhesion to endothelial cells (HUVEC). This effect, mediated by interleukin-1 alpha (IL-1 alpha) and dependent on protein synthesis, is observed even after prolonged anoxia.

Area of Science:

  • Cell Biology
  • Immunology
  • Physiology

Background:

  • Endothelial cells (HUVEC) play a crucial role in regulating immune cell interactions.
  • Anoxia, or low oxygen conditions, can significantly alter cellular functions and responses.
  • Polymorphonuclear leukocytes (PMN) are key immune cells involved in inflammation and host defense.

Purpose of the Study:

  • To investigate the effect of anoxia on the adhesion of human polymorphonuclear leukocytes (PMN) to human umbilical vein endothelial cells (HUVEC).
  • To elucidate the mechanisms underlying anoxia-induced PMN-HUVEC adhesion, including the role of protein synthesis and specific cytokines.

Main Methods:

  • Monolayer cultures of HUVEC were subjected to anoxic conditions for varying durations (4-8 hours).
  • Adhesion of PMN to HUVEC was quantified under anoxic and normoxic conditions.
  • The study utilized cycloheximide to assess the role of protein synthesis and monoclonal antibodies against interleukin-1 alpha (IL-1 alpha) to investigate cytokine involvement.

Main Results:

  • Anoxia significantly increased PMN adhesion to HUVEC, with peak adhesion observed at 4-5 hours.
  • Even after 8 hours of anoxia, PMN adhesion remained elevated compared to normoxic controls.
  • Anoxia-induced adhesion was inhibited by cycloheximide, indicating dependence on HUVEC protein synthesis.
  • The addition of an anti-IL-1 alpha antibody blocked the enhanced PMN adhesion, implicating IL-1 alpha as a mediator.

Conclusions:

  • Endogenous interleukin-1 alpha (IL-1 alpha) acts as a mediator in the anoxia-induced adhesion of PMN to HUVEC.
  • Anoxia triggers protein synthesis in HUVEC, leading to the expression of adhesion-promoting factors.
  • These findings highlight a novel mechanism by which hypoxic conditions can enhance inflammatory cell recruitment to the endothelium.

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