Molecular Medicine

, Volume 20, Issue 1, pp 649–657 | Cite as

Ethyl Pyruvate Inhibits HMGB1 Phosphorylation and Release by Chelating Calcium

  • Joo-Hyun Shin
  • Il-Doo Kim
  • Seung-Woo Kim
  • Hye-Kyung Lee
  • Yinchuan Jin
  • Ju-Hun Park
  • Tae-Kyung Kim
  • Chang-Kook Suh
  • Jiyeon Kwak
  • Keun-Hyeung Lee
  • Pyung-Lim Han
  • Ja-Kyeong Lee
Research Article


Ethyl pyruvate (EP), a simple aliphatic ester of pyruvic acid, has been shown to have antiinflammatory effects and to confer protective effects in various pathological conditions. Recently, a number of studies have reported EP inhibits high mobility group box 1 (HMGB1) secretion and suggest this might contribute to its antiinflammatory effect. Since EP is used in a calcium-containing balanced salt solution (Ringer solution), we wondered if EP directly chelates Ca2+ and if it is related to the EP-mediated suppression of HMGB1 release. Calcium imaging assays revealed that EP significantly and dose-dependently suppressed high K+-induced transient [Ca2+]i surges in primary cortical neurons and, similarly, fluorometric assays showed that EP directly scavenges Ca2+ as the peak of fluorescence emission intensities of Mag-Fura-2 (a low-affinity Ca2+ indicator) was shifted in the presence of EP at concentrations of ≥7 mmol/L. Furthermore, EP markedly suppressed the A23187-induced intracellular Ca2+ surge in BV2 cells and, under this condition, A23187-induced activations of Ca2+-mediated kinases (protein kinase Cα and calcium/calmodulin-dependent protein kinase IV), HMGB1 phosphorylation and subsequent secretion of HMGB1 also were suppressed. (A23187 is a calcium ionophore and BV2 cells are a microglia cell line.) Moreover, the above-mentioned EP-mediated effects were obtained independent of cell death or survival, which suggests that they are direct effects of EP. Together, these results indicate that EP directly chelates Ca2+, and that it is, at least in part, responsible for the suppression of HMGB1 release by EP.



This research was supported by grants from the Mid-Career Researcher Program (grant no. 2012-013195) and the Global Research Network (grant no. 220-2011-1-E00027) of the Korean National Research Foundation (NRF) to J-K Lee.

Supplementary material

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Authors and Affiliations

  • Joo-Hyun Shin
    • 1
  • Il-Doo Kim
    • 1
  • Seung-Woo Kim
    • 1
  • Hye-Kyung Lee
    • 1
  • Yinchuan Jin
    • 1
  • Ju-Hun Park
    • 2
  • Tae-Kyung Kim
    • 3
  • Chang-Kook Suh
    • 4
  • Jiyeon Kwak
    • 4
  • Keun-Hyeung Lee
    • 2
  • Pyung-Lim Han
    • 3
  • Ja-Kyeong Lee
    • 1
  1. 1.Department of AnatomyInha University School of MedicineIncheonRepublic of Korea
  2. 2.Department of ChemistryEwha Womans UniversitySeoulRepublic of Korea
  3. 3.Department of Brain and Cognitive ScienceEwha Womans UniversitySeoulRepublic of Korea
  4. 4.Department of Physiology and BiophysicsInha UniversityIncheonRepublic of Korea

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