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Occludin oligomeric assembly at tight junctions of the blood‐brain barrier is disrupted by peripheral inflammatory hyperalgesia
Author(s) -
McCaffrey Gwen,
Seelbach Melissa J.,
Staatz William D.,
Nametz Nicole,
Quigley Carolyn,
Campos Chris R.,
Brooks Tracy A.,
Davis Thomas P.
Publication year - 2008
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.2008.05582.x
Subject(s) - occludin , paracellular transport , tight junction , chemistry , claudin , blood–brain barrier , biophysics , microbiology and biotechnology , biochemistry , membrane , permeability (electromagnetism) , biology , endocrinology , central nervous system
Tight junctions (TJs) at the blood‐brain barrier (BBB) dynamically alter paracellular diffusion of blood‐borne substances from the peripheral circulation to the CNS in response to external stressors, such as pain, inflammation, and hypoxia. In this study, we investigated the effect of λ‐carrageenan‐induced peripheral inflammatory pain (i.e., hyperalgesia) on the oligomeric assembly of the key TJ transmembrane protein, occludin. Oligomerization of integral membrane proteins is a critical step in TJ complex assembly that enables the generation of tightly packed, large multiprotein complexes capable of physically obliterating the interendothelial space to inhibit paracellular diffusion. Intact microvessels isolated from rat brains were fractionated by detergent‐free density gradient centrifugation, and gradient fractions were analyzed by sodium dodecyl sulfate–polyacrylamide gel electrophoresis/ Western blot. Injection of λ‐carrageenan into the rat hind paw produced after 3 h a marked change in the relative amounts of oligomeric, dimeric, and monomeric occludin isoforms associated with different plasma membrane lipid raft domains and intracellular compartments in endothelial cells at the BBB. Our findings suggest that increased BBB permeability (i.e., leak) associated with λ‐carrageenan‐induced peripheral inflammatory pain is promoted by the disruption of disulfide‐bonded occludin oligomeric assemblies, which renders them incapable of forming an impermeant physical barrier to paracellular transport.