Selective Cre-mediated gene deletion identifies connexin 43 as the main connexin channel supporting olfactory ensheathing cell networks

J Comp Neurol. 2019 May 1;527(7):1278-1289. doi: 10.1002/cne.24628. Epub 2019 Jan 21.

Abstract

Many functions of glial cells depend on the formation of selective glial networks mediated by gap junctions formed by members of the connexin family. Olfactory ensheathing cells (OECs) are specialized glia associated with olfactory sensory neuron axons. Like other glia, they form selective networks, however, the connexins that support OEC connectivity in vivo have not been identified. We used an in vivo mouse model to selectively delete candidate connexin genes with temporal control from OECs and address the physiological consequences. Using this model, we effectively abolished the expression of connexin 43 (Cx43) in OECs in both juvenile and adult mice. Cx43-deleted OECs exhibited features consistent with the loss of gap junctions including reduced membrane conductance, largely reduced sensitivity to the gap junction blocker meclofenamic acid and loss of dye coupling. This indicates that Cx43, a typically astrocytic connexin, is the main connexin forming functional channels in OECs. Despite these changes in functional properties, the deletion of Cx43 deletion did not alter the density of OECs. The strategy used here may prove useful to delete other candidate genes to better understand the functional roles of OECs in vivo.

Keywords: Cre recombinase; RRID:AB_10000325; RRID:AB_141596; RRID:AB_2110187; RRID:AB_2533973; RRID:AB_2533979; RRID:AB_2576217; RRID:AB_561049; RRID:IMSR_JAX:005975; RRID:IMSR_JAX:007914; RRID:IMSR_JAX:008039; connexin 43; gap junctions; olfactory ensheathing cells; proteolipid protein.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aging / metabolism
  • Animals
  • Connexin 43 / deficiency
  • Connexin 43 / genetics
  • Connexin 43 / physiology*
  • Crosses, Genetic
  • Female
  • Gap Junctions / drug effects
  • Gap Junctions / physiology*
  • Gene Knockout Techniques*
  • Genes, Reporter
  • Genes, Synthetic
  • Integrases / genetics
  • Male
  • Meclofenamic Acid / pharmacology
  • Mice
  • Mice, Knockout
  • Myelin Proteolipid Protein / genetics
  • Neuroglia / physiology*
  • Olfactory Bulb / cytology*
  • Olfactory Bulb / metabolism
  • Patch-Clamp Techniques
  • Tamoxifen / pharmacology

Substances

  • Connexin 43
  • GJA1 protein, mouse
  • Myelin Proteolipid Protein
  • Plp1 protein, mouse
  • Tamoxifen
  • Meclofenamic Acid
  • Cre recombinase
  • Integrases