Tight junctions in Schwann cells of peripheral myelinated axons: a lesson from claudin-19-deficient mice

J Cell Biol. 2005 May 9;169(3):527-38. doi: 10.1083/jcb.200501154.

Abstract

Tight junction (TJ)-like structures have been reported in Schwann cells, but their molecular composition and physiological function remain elusive. We found that claudin-19, a novel member of the claudin family (TJ adhesion molecules in epithelia), constituted these structures. Claudin-19-deficient mice were generated, and they exhibited behavioral abnormalities that could be attributed to peripheral nervous system deficits. Electrophysiological analyses showed that the claudin-19 deficiency affected the nerve conduction of peripheral myelinated fibers. Interestingly, the overall morphology of Schwann cells lacking claudin-19 expression appeared to be normal not only in the internodal region but also at the node of Ranvier, except that TJs completely disappeared, at least from the outer/inner mesaxons. These findings have indicated that, similar to epithelial cells, Schwann cells also bear claudin-based TJs, and they have also suggested that these TJs are not involved in the polarized morphogenesis but are involved in the electrophysiological "sealing" function of Schwann cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Axons / metabolism
  • Axons / pathology*
  • Axons / ultrastructure
  • Cell Membrane / metabolism
  • Cell Membrane / pathology
  • Cell Membrane / ultrastructure
  • Claudins
  • Female
  • Male
  • Membrane Proteins / genetics*
  • Membrane Proteins / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Myelin Sheath / metabolism
  • Myelin Sheath / pathology
  • Myelin Sheath / ultrastructure
  • Nerve Fibers, Myelinated / metabolism
  • Nerve Fibers, Myelinated / pathology*
  • Nerve Fibers, Myelinated / ultrastructure
  • Neural Conduction / genetics
  • Peripheral Nerves / abnormalities*
  • Peripheral Nerves / metabolism
  • Peripheral Nerves / ultrastructure
  • Ranvier's Nodes / metabolism
  • Ranvier's Nodes / pathology
  • Ranvier's Nodes / ultrastructure
  • Schwann Cells / metabolism
  • Schwann Cells / pathology*
  • Schwann Cells / ultrastructure
  • Tight Junctions / metabolism
  • Tight Junctions / pathology*
  • Tight Junctions / ultrastructure

Substances

  • Claudins
  • Cldn19 protein, mouse
  • Membrane Proteins