Kusumoto K, Kikuchi M, Fujiwara K, Horiguchi K, Kouki T, Kawanishi K, Yashiro T. Effect of E-cadherin expression on hormone production in rat anterior pituitary lactotrophs in vitro.
Acta Histochem Cytochem 2010;
43:83-8. [PMID:
20514296 PMCID:
PMC2875860 DOI:
10.1267/ahc.10001]
[Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2010] [Accepted: 03/23/2010] [Indexed: 01/31/2023] Open
Abstract
Cadherins are a family of transmembrane glycoproteins that mediate cell-to-cell adhesion. A change in cadherin type in cells, i.e., cadherin switching, induces changes in the character of the cell. Recent studies of the developing rat adenohypophysis found that primordial cells co-expressed E- and N-cadherins, but that hormone-producing cells lost E-cadherin and ultimately possessed only N-cadherin. In the present study, we examined the roles of cadherin switching in cytogenesis of anterior pituitary cells by observing prolactin mRNA and protein expression in lactotrophs that were transformed with an E-cadherin expression vector. In hormone-producing cells that were transfected with a pIRES2-ZsGreen1 plasmid with a full-length E-cadherin cDNA (rE-cad-IZ) insert in primary culture, we detected E- and N-cadherins on plasma membrane and E-cadherin in cytoplasm. In these rE-cad-IZ-transfected cells, in situ hybridization revealed prolactin mRNA signals that were at a level identical to that in control cells, while prolactin protein was barely detectable using immunocytochemistry. The mean signal intensity of prolactin protein in rE-cad-IZ-transfected cells was approximately one fourth that in intact cells and in null-IZ-transfected cells (P<0.01). These results suggest that the expression of E-cadherin does not affect prolactin mRNA transcription; rather, it reduces prolactin protein content, presumably by affecting trafficking of secretory granules.
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