Stains
Claudins - general

Author: Nat Pernick, M.D. (see Authors page)

Revised: 3 December 2015, last major update July 2013

Copyright: (c) 2003-2015, PathologyOutlines.com, Inc.

PubMed Search: claudins
Definition / General
  • Multigene family of integral membrane proteins active in tight junction formation and function
  • Most claudin genes appear decreased in cancer, while CLDN3, CLDN4 and CLDN7 are elevated in several malignancies (BMC Cancer 2006;6:186)
Pathophysiology
  • Tight junctions (zonula occludens) form continuous barrier to fluids across epithelium and endothelium; regulate paracellular permeability and maintain cell polarity by blocking movement of transmembrane proteins between apical and basolateral cell surfaces (Annu Rev Cell Dev Biol 2006;22:207)
  • Tight junctions are composed of claudin and occludin proteins, which join the junctions to the cytoskeleton
  • Claudin family has > 20 integral membrane proteins, expressed in tissue specific pattern that may determine strength and properties of epithelial barrier; usually cells from a specific organ express multiple claudin proteins
Positive Staining - Normal
  • Epithelial and endothelial cells