The pituitary folliculo-stellate cell line TtT/GF augments basal and trhinduced prolactin secretion by GH3 cell

Koike, Koji; Zhang, Zhen Xian; Sakamoto, Yoshiki; Kanda, Yuki; Murakami, Kazuhiko; Miyake, Akira; Inoue, Masakí

doi:10.1016/s0024-3205(97)00984-3

Cited by 10 publications

(6 citation statements)

References 16 publications

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“…In response to these systemic factors, FS cells synthesize and secrete cytokines and growth factors, such as follistatin, IL-6, annexin A1, transforming growth factor b3, and fibroblast growth factor 2 [12][13][14][15], that affect their own growth, that of the anterior pituitary endocrine cells, and the secretion of the anterior pituitary hormones, follicle-stimulating hormone, prolactin, and PMOC1 [4,6,[16][17][18][19]. Because FS cells are both the target and the source of cytokines, they are ideal candidates for the regulation of the function of the anterior pituitary.…”

Section: Introductionmentioning

confidence: 99%

Modulation of GJA1 Turnover and Intercellular Communication by Proinflammatory Cytokines in the Anterior Pituitary Folliculostellate Cell Line TtT/GF1

Fortin¹,

Pelletier²,

Meilleur³

et al. 2006

Biology of Reproduction

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Our previous studies have advanced the idea that the folliculostellate cell GJA1 (gap junction membrane channel protein alpha1; previously known as connexin 43)-mediated gap junctions contribute to the establishment of an intercellular network that regulates the paracrine messages and the endocrine response within the anterior pituitary. The folliculostellate cells are targets for growth factors and cytokines that modulate hormone secretion. Proinflammatory cytokines modulate the cell-to-cell communication in many tissues of the body. The present study measured the effect of the proinflammatory cytokines tumor necrosis factor and interleukin-1 on the GJA1-mediated intercellular communication, specifically the expression, localization, degradation, and phosphorylation status of GJA1 in the folliculostellate cell line TtT/GF. The GJA1 localized to the plasma membrane and to minute cytoplasmic vesicles in the perinuclear area. Using different antibodies that recognize distinctly the nonphosphorylated from the phosphorylated forms of GJA1, we showed that nonphosphorylated GJA1 in Ser-368 (NP-GJA1) localized chiefly in the cytoplasm, whereas GJA1 phosphorylated in Ser-368 (P-GJA1) localized to the plasma membrane in controls. The cytokine treatment transiently increased 1) GJA1, NP-GJA1, and P-GJA1 levels; 2) NP-GJA1 and P-GJA1 degradation by both the lysosomal and proteasomal pathways; and 3) cell-to-cell communication in TtT/GF cells. The results suggest that the cytokine-evoked, transient enhancement of folliculostellate cell-mediated intercellular communication contributes to the coordination of the response among folliculostellate cells.

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Section: Introductionmentioning

confidence: 99%

Modulation of GJA1 Turnover and Intercellular Communication by Proinflammatory Cytokines in the Anterior Pituitary Folliculostellate Cell Line TtT/GF1

Fortin¹,

Pelletier²,

Meilleur³

et al. 2006

Biology of Reproduction

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confidence: 99%

“…In recent years, both cell lines and ‘cell‐enriched’ preparations have been used to advance our understanding of cell‐to‐cell communication in the anterior pituitary gland (20–22). The limitations of using transformed cells in such studies are well documented; nonetheless, these cells provide a unique opportunity to study the interactions between two specific cell types in isolation from others (21). Accordingly, in the present study, we have used co‐cultures of two cell lines [the murine corticotroph cell line, AtT20 (D1 subclone) (23), and the murine folliculo‐stellate cell line, TtT/GF (24)] to investigate the paracrine/juxtacrine interactions between corticotrophs and folliculo‐stellate cells in the manifestation of the ANXA1‐dependent inhibitory actions of glucocorticoids on ACTH release.…”

mentioning

confidence: 99%

Evidence From Studies on Co‐Cultures of TtT/GF and AtT20 Cells That Annexin 1 Acts as a Paracrine or Juxtacrine Mediator of the Early Inhibitory Effects of Glucocorticoids on ACTH Release

Tierney¹,

Christian²,

Morris³

et al. 2003

J Neuroendocrinology

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Annexin 1 (ANXA1) is a key mediator of the inhibitory effects of glucocorticoids on adrenocorticotropic hormone (ACTH) release, which develop within 1-2 h of a steroid challenge. Our previous studies, which showed that (i) ANXA1 is expressed principally by the nonsecretory folliculo-stellate cells in the pituitary gland; (ii) glucocorticoids cause the exportation of ANXA1 from these cells; and (iii) corticotrophs express specific ANXA1 binding sites, led us to propose that ANXA1 serves as a paracrine or juxtacrine mediator of glucocorticoids. To address this hypothesis, we examined ANXA1-dependent glucocorticoid actions in co-cultures of murine corticotroph (AtT20 clone D1) and folliculo-stellate (TtT/GF) cell lines. ANXA1 mRNA and protein were found in abundance in TtT/GF cells but neither was detectable in the AtT20 cells. AtT20 cells (alone and in co-culture with TtT/GF cells) responded to corticotropin-releasing hormone (CRH) (0.1-1 micro m) with increased ACTH release. The CRH-stimulated release of ACTH from AtT20 cells cultured alone was unaffected by preincubation with dexamethasone (Dex, 100 nm); by contrast, in co-cultures of AtT20 and TtT/GF cells, the steroid readily inhibited the secretory response to CRH. The effects of Dex on ACTH release were mimicked by N-terminal ANXA1 fragments (ANXA1Ac2-26, 2 micro g/ml and ANXA11-188, 0.1 ng/ml) and reversed by mifepristone (1 micro m) and by an antisense oligodeoxynucleotide (ODN) to ANXA1 (50 nm) but not by control ODNs. The antisense ODN also specifically blocked the Dex-induced externalization of ANXA1 from TtT/GF cells. Immunofluorescence imaging of the co-cultures localized the exported protein to the vicinity of the AtT20 cells and identified ANXA1 binding sites on these cells. These results provide functional and histological evidence to support our premise that the early inhibitory effects of glucocorticoids on ACTH release are dependent upon paracrine/juxtacrine actions of ANXA1 derived from folliculo-stellate cells.

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“…These paracrine effects of folliculostellate cells on neighbouring endocrine cell function have been studied extensively. They include enhancement of basal and TRH-stimulated PRL secretion by GH $ cells [86], mediation of the inhibitory effects of interferon-γ (IFNγ) on the stimulated release of ACTH, PRL and GH in primary pituitary cultures [87] and release of the proinflammatory cytokine IL-6 in response to VIP [88] and pituitary adenylate cyclase-activating polypeptide (' PACAP ') [89]. In addition, IL-6 is well known to stimulate the release of PRL, GH, LH and folliclestimulating hormone in vitro [90,91] and ACTH in vivo [92].…”

Section: Effects Of Adenosine On Interleukin (Il)-6 and Vascular Endomentioning

confidence: 99%

Novel insights into how purines regulate pituitary cell function

2003

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Purine nucleosides and nucleotides are widely distributed substances that exhibit a diverse range of effects in a number of tissues, acting as important extracellular signalling molecules in addition to their more established roles in cellular metabolism. They mediate their effects via activation of distinct cell surface receptors, termed adenosine (or P1) and P2 purinergic receptors. Although roles for adenosine and adenine nucleotides have been described previously in the pituitary gland, the distribution of the receptor subtypes and the effects of their activation on pituitary function are not well defined. Recent evidence, however, has emerged to describe a complex signalling system for purines in the pituitary gland. Data from a variety of studies have shown that the expression pattern, number and affinity of adenosine and/or P2 receptors may be cell-type specific and that non-endocrine in addition to endocrine cells elaborate these receptors. These variations, along with the diverse range of signalling pathways activated, dictate the response of individual cell types to extracellular purines, with roles now emerging for these substances in the regulation of hormone release, pituitary cell proliferation and cytokine/growth factor expression. In this review, we discuss these advances and examine some implications for pituitary growth control and the response of the hypothalamic-pituitary-adrenal axis to stress and inflammation.

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The pituitary folliculo-stellate cell line TtT/GF augments basal and trhinduced prolactin secretion by GH3 cell

Cited by 10 publications

References 16 publications

Modulation of GJA1 Turnover and Intercellular Communication by Proinflammatory Cytokines in the Anterior Pituitary Folliculostellate Cell Line TtT/GF1

Modulation of GJA1 Turnover and Intercellular Communication by Proinflammatory Cytokines in the Anterior Pituitary Folliculostellate Cell Line TtT/GF1

Evidence From Studies on Co‐Cultures of TtT/GF and AtT20 Cells That Annexin 1 Acts as a Paracrine or Juxtacrine Mediator of the Early Inhibitory Effects of Glucocorticoids on ACTH Release

Novel insights into how purines regulate pituitary cell function

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