Effects of intracellular zinc depletion on the expression of VDAC in cultured hippocampal neurons

Nutr Neurosci. 2011 Mar;14(2):80-7. doi: 10.1179/1476830511Y.0000000004.

Abstract

An experiment was conducted to investigate whether intracellular zinc depletion can actually change expression of voltage-dependent anion channel 1 (VDAC1) and VPAC2 in cultured hippocampal neurons as well as their significance. Hippocampal neurons were obtained by primary culture from hippocampus of newborn Wistar rats. Cultured hippocampal neurons were exposed to a cell membrane-permeable zinc chelator N,N,N',N'-tetrakis (2-pyridyl methyl) ethylenediamine (TPEN) (2 µM), and to TPEN plus zinc sulfate (5 µM) for 1 or 24 hours. Cultures were then processed to detect neuronal injury by lactate dehydrogenase (LDH) assay, intracellular Ca(2+) with the fluorescent probe fluo-3/AM, reactive oxygen species (ROS) generation using 2',7'-dichlorofluorescein diacetate (DCFH-DA) assay, nuclear morphology by Hoechst 33342, VDAC1, and VDAC2 protein levels by western blot, and VDAC1 and VDAC2 mRNA levels by RT-PCR. The results demonstrated that exposure of hippocampal neurons to TPEN (2 µM) for 24 hours induced notably neuronal injury, significantly increased the number of apoptotic nuclei, up-regulated the expression of VDAC1 protein level and down-regulated the expression of VDAC2 protein level. Significant down-regulation of mRNA levels for VDAC1 and VDAC2 were observed in TPEN-treated neurons. Co-addition of zinc almost completely reversed TPEN-induced neuronal injury and above alterations in VDAC1 and VDAC2 protein levels and mRNA levels. Present results implicate a possibility that up-regulation of VDAC1 and down-regulation of VDAC2 may participate in hippocampal neuron injury induced by zinc deficiency.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Newborn
  • Apoptosis / drug effects
  • Blotting, Western
  • Cells, Cultured
  • Down-Regulation
  • Ethylenediamines / metabolism
  • Fluoresceins / metabolism
  • Hippocampus / cytology*
  • Hippocampus / metabolism
  • Hippocampus / pathology
  • L-Lactate Dehydrogenase / metabolism
  • Neurodegenerative Diseases / pathology
  • Neurodegenerative Diseases / prevention & control
  • Neurons / cytology
  • Neurons / pathology*
  • Polymerase Chain Reaction
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Rats
  • Rats, Wistar
  • Reactive Oxygen Species / metabolism
  • Up-Regulation
  • Voltage-Dependent Anion Channel 1 / genetics
  • Voltage-Dependent Anion Channel 1 / metabolism*
  • Voltage-Dependent Anion Channel 2 / genetics
  • Voltage-Dependent Anion Channel 2 / metabolism*
  • Zinc / deficiency*

Substances

  • Ethylenediamines
  • Fluoresceins
  • RNA, Messenger
  • Reactive Oxygen Species
  • Vdac1 protein, rat
  • Vdac2 protein, rat
  • Voltage-Dependent Anion Channel 2
  • diacetyldichlorofluorescein
  • L-Lactate Dehydrogenase
  • Voltage-Dependent Anion Channel 1
  • Zinc
  • N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine