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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Loss of Basal and TRH-Stimulated Tshb Expression in Dispersed Pituitary Cells

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Author(s):
Bargi-Souza, Paula [1, 2] ; Kucka, Marek [2] ; Bjelobaba, Ivana [2] ; Tomic, Melanija [2] ; Janjic, Marija M. [2] ; Nunes, Maria Tereza [1] ; Stojilkovic, Stanko S. [2]
Total Authors: 7
Affiliation:
[1] Univ Sao Paulo, Inst Biomed Sci, Dept Physiol & Biophys, BR-05508000 Sao Paulo, SP - Brazil
[2] Eunice Kennedy Shiver Natl Inst Child Hlth & Huma, NIH, Sect Cellular Signaling, Bethesda, MD 20892 - USA
Total Affiliations: 2
Document type: Journal article
Source: Endocrinology; v. 156, n. 1, p. 242-254, JAN 2015.
Web of Science Citations: 11
Abstract

This study addresses the in vivo and in vitro expression pattern of three genes that are operative in the thyrotroph subpopulation of anterior pituitary cells: glycoprotein alpha-chain (Cga), thyroid-stimulating hormone beta-chain (Tshb), and TRH receptor (Trhr). In vivo, the expression of Cga and Tshb was robust, whereas the expression of Trhr was low. In cultured pituitary cells, there was a progressive decline in the expression of Cga, Tshb, and Trhr. The expression of Tshb could not be reversed via pulsatile or continuous TRH application in variable concentrations and treatment duration or by the removal of thyroid and steroid hormones from the sera. In parallel, the expression of CGA and TSHB proteins declined progressively in pituitary cells from both sexes. The lack of the effect of TRH on Tshb expression was not related to the age of pituitary cultures and the presence of functional TRH receptors. In cultured pituitary fragments, there was also a rapid decline in expression of these genes, but TRH was able to induce transient Tshb expression. In vivo, thyrotrophs were often in close proximity to each other and to somatotroph and folliculostellate cell networks and especially to the lactotroph cell network; such an organization pattern was lost in vitro. These observations suggest that the lack of influence of anterior pituitary architecture and/or intrapituitary factors probably accounts for the loss of basal and TRH-stimulated Tshb expression in dispersed pituitary cells. (AU)

FAPESP's process: 12/06643-8 - Rapid actions of triiodothyronine (T3) on intracellular calcium and membrane potential of thyrotrophs and implications on TSH secretion
Grantee:Paula Bargi de Souza
Support Opportunities: Scholarships abroad - Research Internship - Doctorate