Folliculostellate cells interact with microvessel mural cell ‘pericyte' to maintain collagen arrangement in rat anterior pituitary

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: SAT 164-196-Pituitary
Basic/Clinical
Saturday, June 15, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board SAT-191
Takehiro Tsukada*, Ken Fujiwara, Dini Ramadhani, Tom Kouki, Motoshi Kikuchi and Takashi Yashiro
Jichi Medical University School of Medicine
The anterior pituitary gland is made up of organized tissue comprising multiple cell types, including 5 types of hormone-producing cells. In particular, non-granular folliculostellate (FS) cells interconnect homotypically to build 3-dimensional (3D) meshwork, which assist in retaining mechanical structure in the anterior pituitary. In addition to structural function, several other functions of FS cell have been postulated in the anterior pituitary such as phagocytes, stem/progenitor cells, and intra-pituitary communicator. To seek further FS cell functions in physiologically relevant environment, we recently developed 3D cell culture system using rat anterior pituitary cells, which faithfully reproduces the in vivo-like cell-cell and cell-extracellular matrix architecture including FS cell morphology. In the present study, by use of S100b-GFP transgenic rats that specifically express GFP in the FS cells, we cultured anterior pituitary cells in the 3D environment with and without FS cells. In the presence of FS cells, anterior pituitary cells formed a spherical cell aggregate having smooth outer layer. Interestingly, removal of FS cells displayed larger and amorphous cell aggregates. Quantitative real-time PCR result showed that loss of FS cells specifically down-regulated expression of regulator of G-protein signaling 5 (a marker of pericytes), while it did not alter expression level of adenohypophysial hormone genes and endothelial cell markers. Pericyte is mural cell of the blood microvessels and interact with endothelial cells to maintain vascular homeostasis. As our previous study showed that pericyte is sole collagen-producing cells in the anterior pituitary, we next immunohistochemically stained for type I and III collagens. In the absence of FS cells, extracellular collagen deposition was not observed in contrast to rich collagen deposition in the presence of FS cells. Concomitantly, expressions of type I and III collagen genes were significantly lower in the absence of FS cells. These results suggest that FS cells interact with pericytes to maintain collagen arrangement in the anterior pituitary and that the loss of this interaction results in specific deterioration of pericyte activity.

Nothing to Disclose: TT, KF, DR, TK, MK, TY

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm

Sources of Research Support: Grant-in-Aid for Scientific Research (C) (22590192) from the Ministry of Education, Culture, Sports, Science and Technology of Japan; Grant-in-Aid for Young Scientists (B) (23790233) from the Ministry of Education, Culture, Sports, Science and Technology of Japan; promotional funds for the Keirin Race of the Japan Keirin Association; the Jichi Medical University Young Investigator Award from Jichi Medical University School of Medicine