Zinc regulates meiotic resumption in porcine oocytes via a protein kinase C-related pathway

PLoS One. 2014 Jul 14;9(7):e102097. doi: 10.1371/journal.pone.0102097. eCollection 2014.

Abstract

Zinc is an extremely important trace element that plays important roles in several biological processes. However, the function of zinc in meiotic division of porcine oocytes is unknown. In this study, we investigated the role of zinc during meiotic resumption in in vitro matured porcine oocytes. During meiotic division, a massive release of zinc was observed. The level of free zinc in the cytoplasm significantly increased during maturation. Depletion of zinc using N, N, N', N'-tetrakis (2-pyridylmethyl) ethylenediamine (TPEN), a Zn2+ chelator, blocked meiotic resumption in a dose dependent manner. The level of phosphorylated mitogen activated protein kinase (MAPK) and p34cdc2 kinase activity were reduced when zinc was depleted. Moreover, zinc depletion reduced the levels of phosphorylated protein kinase C (PKC) substrates in a dose dependent manner. Real-time PCR analysis showed that expression of the MAPK- and maturation promoting factor related genes C-mos, CyclinB1, and Cdc2 was downregulated following zinc depletion. Treatment with the PKC agonist phorbol 12-myristate 13-acetate (PMA) increased phosphorylation of PKC substrates and MAPK and increased p34cdc2 kinase activity. This rescued the meiotic arrest, even in the presence of TPEN. Activation of PKC by PMA increased the level of zinc in the cytoplasm. These data demonstrate that zinc is required for meiotic resumption in porcine oocytes, and this appears to be regulated via a PKC related pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CDC2 Protein Kinase / metabolism
  • Chelating Agents / metabolism
  • Chelating Agents / pharmacology
  • Cyclin B1 / metabolism
  • Dose-Response Relationship, Drug
  • Ethylenediamines / metabolism
  • Ethylenediamines / pharmacology
  • Female
  • Gene Expression Regulation / drug effects
  • In Vitro Techniques
  • Meiosis / drug effects
  • Meiosis / physiology*
  • Mitogen-Activated Protein Kinases / metabolism
  • Oocytes / physiology*
  • Protein Kinase C / metabolism*
  • Proto-Oncogene Proteins c-mos / metabolism
  • Real-Time Polymerase Chain Reaction
  • Signal Transduction / physiology*
  • Swine / physiology*
  • Tetradecanoylphorbol Acetate / metabolism
  • Zinc / deficiency
  • Zinc / metabolism*

Substances

  • Chelating Agents
  • Cyclin B1
  • Ethylenediamines
  • Proto-Oncogene Proteins c-mos
  • Protein Kinase C
  • CDC2 Protein Kinase
  • Mitogen-Activated Protein Kinases
  • Zinc
  • Tetradecanoylphorbol Acetate
  • N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine

Grants and funding

This work was supported by grants from the Next-Generation BioGreen 21 Program (PJ00909801 and PJ009594), Rural Development Administration, Republic of Korea. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.