Rapid shedding of proinflammatory microparticles by human mononuclear cells exposed to cigarette smoke is dependent on Ca2+ mobilization

Inflamm Res. 2014 Jul;63(7):539-47. doi: 10.1007/s00011-014-0723-7. Epub 2014 Mar 6.


Objectives: Microparticles are membrane vesicles shed by cells upon activation and apoptosis. Agonists capable of inducing microparticle generation include cytokines, bacterial products, P-selectin, histamine. Cigarette smoke extract has also been recognized as an agonist involved in microparticle generation with an apoptosis-dependent mechanism. We investigated the possibility that cigarette smoke extract induces the rapid generation of proinflammatory microparticles by human mononuclear cells with a calcium-dependent mechanism.

Materials and methods: Human mononuclear cells were exposed to cigarette smoke extract. [Ca(2+)]i mobilization was assessed with the fluorescent probe Fluo-4 NW. Microparticles were quantified with a prothrombinase assay and by flow cytometry. Normal human bronchial epithelial cells and A549 alveolar cells were incubated with cigarette smoke extract-induced microparticles and the generation of ICAM-1, IL-8, and MCP-1 was assessed by ELISA.

Results: Exposure to cigarette smoke extract induced a rapid increase in [Ca(2+)]i mobilization. Microparticle generation was also increased. EGTA, verapamil and the calmodulin inhibitor, W-7, inhibited microparticle generation. Incubation of lung epithelial cells with cigarette smoke extract-induced microparticles increased the expression of proinflammatory mediators.

Conclusions: Exposure of mononuclear cells to cigarette smoke extract causes a rapid shedding of microparticles with a proinflammatory potential that might add to the mechanisms of disease from tobacco use.

MeSH terms

  • Apoptosis / drug effects
  • Bronchi / cytology
  • Calcium / metabolism*
  • Cell Line, Tumor
  • Cell Survival / drug effects
  • Cell-Derived Microparticles / drug effects*
  • Cells, Cultured
  • Chemokine CCL2 / metabolism
  • Complex Mixtures / pharmacology*
  • Epithelial Cells
  • Humans
  • Intercellular Adhesion Molecule-1 / metabolism
  • Interleukin-8 / metabolism
  • Leukocytes, Mononuclear / drug effects*
  • Leukocytes, Mononuclear / metabolism
  • Smoke*
  • Tobacco*


  • CCL2 protein, human
  • CXCL8 protein, human
  • Chemokine CCL2
  • Complex Mixtures
  • ICAM1 protein, human
  • Interleukin-8
  • Smoke
  • Intercellular Adhesion Molecule-1
  • Calcium