Plasma corticosterone activates SGK1 and induces morphological changes in oligodendrocytes in corpus callosum

PLoS One. 2011;6(5):e19859. doi: 10.1371/journal.pone.0019859. Epub 2011 May 31.

Abstract

Repeated stressful events are known to be associated with onset of depression. Further, stress activates the hypothalamic-pituitary-adrenocortical (HPA) system by elevating plasma cortisol levels. However, little is known about the related downstream molecular pathway. In this study, by using repeated water-immersion and restraint stress (WIRS) as a stressor for mice, we attempted to elucidate the molecular pathway induced by elevated plasma corticosterone levels. We observed the following effects both, in vivo and in vitro: (1) repeated exposure to WIRS activates the 3-phosphoinositide-dependent protein kinase (PDK1)-serum glucocorticoid regulated kinase (SGK1)-N-myc downstream-regulated gene 1 (NDRG1)-adhesion molecule (i.e., N-cadherin, α-catenin, and β-catenin) stabilization pathway via an increase in plasma corticosterone levels; (2) the activation of this signaling pathway induces morphological changes in oligodendrocytes; and (3) after recovery from chronic stress, the abnormal arborization of oligodendrocytes and depression-like symptoms return to the control levels. Our data strongly suggest that these abnornalities of oligodendrocytes are possibly related to depression-like symptoms.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Western
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism
  • Corpus Callosum / cytology*
  • Corticosterone / blood*
  • Immediate-Early Proteins / genetics
  • Immediate-Early Proteins / metabolism*
  • Immunohistochemistry
  • In Situ Hybridization
  • Intracellular Signaling Peptides and Proteins / genetics
  • Intracellular Signaling Peptides and Proteins / metabolism
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Microscopy, Electron, Transmission
  • Oligodendroglia / cytology*
  • Oligodendroglia / metabolism*
  • Oligodendroglia / ultrastructure
  • Phosphatidylinositol 3-Kinases / genetics
  • Phosphatidylinositol 3-Kinases / metabolism
  • Phosphorylation
  • Protein Serine-Threonine Kinases / genetics
  • Protein Serine-Threonine Kinases / metabolism*
  • Pyruvate Dehydrogenase Acetyl-Transferring Kinase
  • Restraint, Physical / physiology
  • Reverse Transcriptase Polymerase Chain Reaction
  • Stress, Physiological / physiology

Substances

  • Cell Cycle Proteins
  • Immediate-Early Proteins
  • Intracellular Signaling Peptides and Proteins
  • N-myc downstream-regulated gene 1 protein
  • Pdk1 protein, mouse
  • Pyruvate Dehydrogenase Acetyl-Transferring Kinase
  • Protein Serine-Threonine Kinases
  • serum-glucocorticoid regulated kinase
  • Corticosterone