Temporal neutrophil polarization following myocardial infarction

Yonggang Ma, Andriy Yabluchanskiy, Rugmani Padmanabhan Iyer, Presley L. Cannon, Elizabeth R. Flynn, Mira Jung, Jeffrey Henry, Courtney A. Cates, Kristine Y. Deleon-Pennell, Merry L. Lindsey

Research output: Contribution to journalArticlepeer-review

174 Scopus citations


Aims: Although macrophage phenotypes have been well studied in the myocardial infarction (MI) setting, this study investigated temporal neutrophil polarization and activation mechanisms. Methods and results: Neutrophils isolated from the infarcted left ventricle (LV) of mice showed high expression of proinflammatory markers at Day 1 and anti-inflammatory markers at Days 5 and 7 post-MI, indicating distinct neutrophil phenotypes along the post-MI time continuum. Flow cytometry analysis revealed that although proinflammatory N1 neutrophils were always predominant (.80% of total neutrophils at each time point), the percentage of N2 neutrophils increased post-MI from 2.4+0.6% at Day 1 to 18.1+3.0% at Day 7. In vitro, peripheral blood neutrophils were polarized to proinflammatory N1 by lipopolysaccharide and interferon-γ or anti-inflammatory N2 by interleukin-4, indicating high plasticity potential. The in vivo post-MI relevant LV damage-Associated molecular patterns (DAMPs) polarized neutrophils to a proinflammatory N1 phenotype by activating toll-like receptor-4. Transforming growth factor-β1 inhibited proinflammatory production in neutrophils. N1 neutrophils positively correlated with infarct wall thinning at Day 7 post-MI, possibly due to high production of matrix metalloproteinases-12 and -25. Conclusion: This study is the first to identify the existence of N1 and N2 neutrophils in the infarct region and reveals that N1 polarization could be mediated by DAMPs.

Original languageEnglish (US)
Pages (from-to)51-61
Number of pages11
JournalCardiovascular research
Issue number1
StatePublished - May 1 2016
Externally publishedYes


  • DAMPs
  • Inflammation
  • Myocardial infarction
  • Neutrophil polarization
  • Proteomics

ASJC Scopus subject areas

  • Physiology
  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)


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