Morphometric analysis of the folliculostellate cells and luteinizing hormone gonadotropic cells of the anterior pituitary of the men during the aging process

Intratumoural spatial distribution of S100B + folliculostellate cells is associated with proliferation and expression of FSH and ERα in gonadotroph tumours

Folliculostellate cells are S100B-expressing cells with numerous functions in the normal anterior pituitary. These cells have also been identified in pituitary neuroendocrine tumours (PitNETs), where their precise role remains elusive. Here, we aimed to build a refined cartography of S100B-expressing cells to characterise their interpatient and intratumoural spatial distribution, and to start identifying their potential functions in PitNETs. High-throughput histological analysis of S100B-stained tumour sections of 54 PitNETs revealed a significant decrease in S100B + cells in PitNETs compared to the normal anterior pituitary. A Ki67 index ≥ 3, a mitosis count > 2/10 per high power fields, and a proliferative status, were all associated with fewer S100B + cells in gonadotroph tumours. Gonadotroph tumours also showed interpatient and intratumoural heterogeneity in the spatial distribution of S100B + cells. The existence of an intratumoural heterogeneity was further confirmed by the incorporation to our spatial analysis of additional markers: Ki67, FSH, LH, ERα and SSTR2. The tumour areas with fewer S100B + cells displayed a higher percentage of Ki67 + cells, whereas strong positive correlations were observed between S100B + , FSH + , and ERα + cells. Such spatial associations suggest that S100B + folliculostellate cells could play a role in gonadotroph tumorigenesis, and may contribute to the maintenance of tumour cells in a low proliferating, FSH + /ERα + differentiated state. Albeit, further in-depth functional studies are required to decipher the mechanisms underlying these spatial associations and to potentially identify a therapeutic use.

Morphometric analysis of somatotropic and folliculostellate cells of human anterior pituitary during ageing

Introduction/Objective. In this study, we have pointed out the immunohistomorphometric characteristics of somatotropic (GH) and folliculo-stellate (FS) cells of the human pituitary gland during ageing. Methods. On histological sections of the pituitary gland of 14 male cadavers of different ages, the GH and FS cells were immunohistochemically labeled with corresponding antibodies, monoclonal anti-GH antibody and polyclonal anti-S100 antibody, respectively. Immunopositive GH- and FS-cells were further morphometrically analyzed using ImageJ software. Results. The obtained results of morphometric analysis showed that the surface area of GH cells increased significantly with age. In these cells, the nuclear-cytoplasmic ratio gradually decreased and became significantly higher after the age of 70 years. The volume density of GH cells has not changed during ageing, while in FS cells this parameter significantly increased in the cases older than 70 years. The nuclear-cytoplasmic ratio of GH cells is negatively correlated with the volume density of FS cells. Conclusions. Based on the obtained results, we concluded that hypertrophy of GH and FS cells occurs in men with ageing and that correlation between the morphometric parameters of these two cell types indicates their mutual interaction.

Renewing an old interest: Pituitary folliculostellate cells

Anterior pituitary folliculostellate (FS) cells, first described almost 50 years ago, have a wide range of functions with respect to supporting and coordinating endocrine cell function, in particular through paracrine and gap junction-mediated signalling. Our previous studies identified the morphological organisation of FS cells, which mediates coordinated calcium activity throughout the homotypic FS network and allows signalling across the whole pituitary gland. It is also clear that FS cells can modify endocrine output and feedback on pituitary axes over a range of timescales. Recently, several studies have defined FS cells as a source of anterior pituitary endocrine cell renewal, which has resulted in a renaming of FS cells as "Sox2+ve stem cells". Here, we highlight the broader potential of the FS cell population in fine-tuning and coordinating pituitary axes function. In addition, we identify a need for: the definition of the possible subtypes of FS cell and their relationship with the stem cell population; the potential role of FS cells in pulsatile hormone secretion and coordination of heterotypic cell networks; and the roles that FS cells may play in both early-life programming of pituitary axes and in memory, or anticipation, of demand. Further studies of FS cells may demonstrate the fundamental importance of this cell type and its potential as a therapeutic target to correct pituitary gland dysfunction, one of which is stem cell therapy. Clearly, a thorough understanding of all of these interactions and relationships of FS and endocrine cells is required whatever therapeutic use is suggested by their various roles.