Zinc induced apoptotic death of mouse dendritic cells

Apoptosis. 2010 Oct;15(10):1177-86. doi: 10.1007/s10495-010-0520-x.

Abstract

Zinc ions (Zn(2+)) are food components with favourable effects in infectious disease. Zn(2+) is taken up into dendritic cells (DCs), key players in the regulation of innate and adaptive immunity. In other cell types, Zn(2+) has been shown to stimulate the formation of ceramide, which is in turn known to trigger suicidal cell death. The present study explored whether Zn(2+) modifies ceramide formation and survival of bone marrow derived DCs. To this end, DCs were isolated from acid sphingomyelinase knockout (asm (-/-)) and corresponding wild type (asm (+/+)) mice and treated with different concentrations of Zn(2+). Ceramide formation was assessed with anti-ceramide antibodies in FACS and immunohistochemical analysis, sub-G1 cell population by FACS analysis, break down of phosphatidylserine asymmetry by annexin V binding, cell death by propidium iodide incorporation, metabolic cell activity by MTT assay, ROS production from dichlorofluorescein fluorescence and activation of MAPKs by Western blotting. The treatment of asm (+/+) DCs with low Zn(2+) concentrations (up to 100 μM) was followed by ceramide formation, increase in sub-G1 cell population and phosphatidylserine exposure, effects blunted in asm (-/-) DCs. The treatment of DCs with C2-ceramide increased the percentage of sub-G1 and apoptotic DCs from both genotypes. Zn(2+) led to similar activation of MAPKs in asm (+/+) and asm (-/-) DCs and did not affect ROS production. Higher concentrations of Zn(2+) led to a marked increase of propidium iodide incorporation in DCs of both genotypes. The present study reveals that in DCs Zn(2+) triggers ceramide formation, which in turn compromises cell survival.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Annexin A5 / analysis
  • Apoptosis / drug effects*
  • B7-2 Antigen / analysis
  • Ceramides / biosynthesis*
  • Dendritic Cells / drug effects*
  • Dendritic Cells / physiology
  • Flow Cytometry
  • Gene Knockout Techniques
  • Immunoblotting
  • Mice
  • Mice, Knockout
  • Reactive Oxygen Species / metabolism
  • Sphingomyelin Phosphodiesterase / genetics
  • Zinc / pharmacology*

Substances

  • Annexin A5
  • B7-2 Antigen
  • Ceramides
  • Reactive Oxygen Species
  • Sphingomyelin Phosphodiesterase
  • Zinc