Anterior and intermediate pituitary tissues express claudin 4 in follicle stellate cells and claudins 2 and 5 in endothelial cells

作者：Garcia Godinez Alejandro; Gerardo Contreras Ruben; Gonzalez del Pliego Margarita; Aguirre Benitez Elsa; Acuna Macias Isabel; Teresa de la Vega M; Martin Tapia Dolores; Solano Agama Carmen; Eugenia Mendoza Garrido M

来源：Cell and Tissue Research, 2014, 357(1): 309-321.

DOI：10.1007/s00441-014-1827-7

• Pituitary organization
• Claudins 2 and 4
• Follicle-stellate cells
• Pituitary epithelium
• Pituitary endothelium

Follicle-stellate cells are pituitary non-granular cells that are arranged between secretory cells or organized in follicles with small lumens. Cells from the follicles exhibit the typical phenotype of a transporting epithelium, including apical microvilli with a cilium and tight junctions. Freeze-fracture electron microscopy images show that the tight junctions consist of 5-7 anastomosing strands and that cultured follicle-stellate cells develop a trans-epithelial electrical resistance characteristic of "tight" epithelia. Here, we investigate the molecular composition of the tight junction from follicle stellate cells. We found that the rat anterior pituitary lobe expresses mRNAs for claudins 2, 4 and 5; the proteins of all these claudins are observed in the anterior lobe, whereas the intermediate lobe expresses claudins 2 and 5 and the posterior lobe contains only claudin 5. Follicle-stellate cells, identified by their protein marker S100 beta, expresses claudin 4 in the apical membrane, in co-localization with dipeptidyl-peptidase and near acetylated beta-tubulin. Claudin 4 partially co-localizes with E-cadherin, indicating that a fraction of the protein is located in the basolateral domain. Follicle-stellate-enriched cell cultures develop patches of polygonal cells expressing claudin 4 and E-cadherin, encircled by extensive monolayers of fusiform cells. Claudin 2 stains specifically blood vessels, identified by claudin 5 and VE-cadherin labels. Thus, follicles in the anterior pituitary consist of "tight" epithelia that can carry out intense vectorial transport, together with a high cation movement in blood vessels, possibly related to the ion requirements of excitable secretory cells for hormone secretion.

• 出版日期2014-7