Differential distribution of tight junction proteins suggests a role for tanycytes in blood-hypothalamus barrier regulation in the adult mouse brain

Autor: Mullier, Amandine, Bouret, Sébastien, Prevot, Vincent, Dehouck, Bénédicte
Přispěvatelé: Prevot, Vincent, Blanc - - gliodiabesity2009 - ANR-09-BLAN-0267 - Blanc - VALID, Centre de Recherche Jean-Pierre AUBERT Neurosciences et Cancer - U837 (JPArc), Université Lille Nord de France (COMUE)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Lille, Neuroscience program, University of Southern California (USC)-The Saban research institute, NEUROBESE International Associated Laboratory(INSERM, SABAN, University of Lille2, to VP and SGB), the CNRS(to SGB), the ANR (to VP), the fondation pour la recherche médicale (to VP). AM was a Ph.D student supported by a fellowship from the french 'Ministère délégué à la recherche et aux nouvelles technologies', ANR-09-BLAN-0267,gliodiabesity(2009)
Jazyk: angličtina
Rok vydání: 2010
Předmět:
Zdroj: Journal of Comparative Neurology
Journal of Comparative Neurology, 2010, 518 (7), pp.943-62. ⟨10.1002/cne.22273⟩
ISSN: 0021-9967
1096-9861
DOI: 10.1002/cne.22273⟩
Popis: International audience; The median eminence is one of the seven so-called circumventricular organs. It is located in the basal hypothalamus, ventral to the third ventricle and adjacent to the arcuate nucleus. This structure characteristically contains a rich capillary plexus and features a fenestrated endothelium, making it a direct target of blood-borne molecules. The median eminence also contains highly specialized ependymal cells called tanycytes, which line the floor of the third ventricle. It has been hypothesized that one of the functions of these cells is to create a barrier that prevents substances in the portal capillary spaces from entering the brain. In this paper, we utilize immunohistochemistry to study the expression of tight junction proteins in the cells that compose the median eminence in adult mice. Our results indicate that tanycytes of the median eminence express occludin, ZO-1, and claudin 1 and 5, but not claudin 3. Remarkably, these molecules are organized as a continuous belt around the cell bodies of the tanycytes that line the ventral part of the third ventricle. In contrast, the tanycytes at the periphery of the arcuate nucleus do not express claudin 1 and instead exhibit a disorganized expression pattern of occludin, ZO-1, and claudin 5. Consistent with these observations, permeability studies using peripheral or central injections of Evans blue dye show that only the tanycytes of the median eminence are joined at their apices by functional tight junctions, whereas tanycytes located at the level of the arcuate nucleus form a permeable layer. In conclusion, this study reveals a unique expression pattern of tight junction proteins in hypothalamic tanycytes, which yields new insights into their barrier properties.
Databáze: OpenAIRE
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