Hippocampal seizures alter the expression of the pannexin and connexin transcriptome

Authors

  • Shanthini Mylvaganam,

    1. Division of Fundamental Neurobiology, Toronto Western Research Institute, University Health Network, Toronto, Ontario, Canada
    Search for more papers by this author
  • Liang Zhang,

    1. Division of Fundamental Neurobiology, Toronto Western Research Institute, University Health Network, Toronto, Ontario, Canada
    2. Department of Physiology, University of Toronto, Toronto, Ontario, Canada
    Search for more papers by this author
  • Chiping Wu,

    1. Division of Fundamental Neurobiology, Toronto Western Research Institute, University Health Network, Toronto, Ontario, Canada
    Search for more papers by this author
  • Zhang Jane Zhang,

    1. Division of Fundamental Neurobiology, Toronto Western Research Institute, University Health Network, Toronto, Ontario, Canada
    2. Department of Physiology, University of Toronto, Toronto, Ontario, Canada
    Search for more papers by this author
  • Marina Samoilova,

    1. Division of Fundamental Neurobiology, Toronto Western Research Institute, University Health Network, Toronto, Ontario, Canada
    Search for more papers by this author
  • James Eubanks,

    1. Division of Fundamental Neurobiology, Toronto Western Research Institute, University Health Network, Toronto, Ontario, Canada
    2. Department of Physiology, University of Toronto, Toronto, Ontario, Canada
    3. Department of Surgery, University of Toronto, Toronto, Ontario, Canada
    Search for more papers by this author
  • Peter L. Carlen,

    1. Division of Fundamental Neurobiology, Toronto Western Research Institute, University Health Network, Toronto, Ontario, Canada
    2. Department of Physiology, University of Toronto, Toronto, Ontario, Canada
    3. Department of Medicine (Neurology), University of Toronto, Toronto, Ontario, Canada
    4. The Epilepsy Research Program, University of Toronto, Toronto, Ontario, Canada
    Search for more papers by this author
  • Michael O. Poulter

    1. Molecular Brain Research Group, Robarts Research Institute, University of Western Ontario, London, Ontario, Canada
    2. Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada
    Search for more papers by this author

Address correspondence and reprint requests to Michael O. Poulter, Ph.D., Molecular Brain Research Group, Department of Physiology and Pharmacology, Faculty of Medicine, Robarts Research Institute, University of Western Ontario, 100 Perth Drive, London ON, Canada N6A 5K8. E-mail: mpoulter@robarts.ca

Abstract

J. Neurochem. (2010) 112, 92–102.

Abstract

Some forms of seizure activity can be stopped by gap junctional (GJ) blockade. Here, we found that GJ blockers attenuate hippocampal seizure activity induced by a novel seizuregenic protocol using Co2+. We hypothesized that this activity may occur because of the altered expression of connexin (Cx) and/or pannexin (Panx) mRNAs and protein. We found a 1.5-, 1.4-, and 2-fold increase in Panx1, Panx2, and Cx43 mRNAs, respectively. Significant post-translational modifications of the proteins Cx43 and Panx1 were also observed after the Co2+ treatment. No changes were observed in the presence of tetrodotoxin, indicating that seizure activity is required for these alterations in expression, rather than the Co2+ treatment itself. Further analysis of the QPCR data showed that the Cx and Panx transcriptome becomes remarkably re-organized. Pannexin (Panxs 1 and 2) and glial connexin mRNA became highly correlated to one another; suggesting that these genes formed a transcriptomic network of coordinated gene expression, perhaps facilitating seizure induction. These data show that seizure activity up-regulates the expression of both glial and neuronal GJ mRNAs and protein while inducing a high degree of coordinate expression of the GJ transcriptome.

Ancillary