Intercellular communication within the rat anterior pituitary gland: X. Immunohistocytochemistry of S-100 and connexin 43 of folliculo-stellate cells in the rat anterior pituitary gland

Since Rinehart and Farquhar reported the presence of agranulated cells in the anterior pituitary gland in 1953, the functions of the folliculo-stellate cell remain to be clarified. Intercellular junctions have been described in the monkey, rat, and teleost anterior pituitary glands, indicating the existence of cell-to-cell communication within the organ. We pointed to their possible role in the rapid dissemination of information through a complex interconnecting system of follicles involving gap junctions. The gap junctional/folliculo-stellate cellular network was essential in the maturation and regulation of the pituitary gland system such as the hypothalamic-pituitary-gonadal axis. It has been was shown that a network participated in the conduction of electrophysiological information over a long distance using the ion Ca(++), which propagates to other folliculo-stellate cells by signaling through gap junctions. Sixty-day-old male rats were used in this study for light microscopic immunohistochemistry of S-100 protein, type I collagen, and connexin 43, and for electron microscopy to observe the morphological relationships between the cellular networks of folliculo-stellate cells and granulated pituitary cells. Clusters of anti-S-100 protein-positive cells were clearly observed in a region of the hypophysis tentatively named the transition zone. Anti-S-100 protein-positive cells and their cytoplasmic processes were also present in the anterior lobe and assembled together to form follicular lumina. Type I collagen was clearly shown outlining the incomplete lobular or ductule-like structure making cell cords in the anterior pituitary gland. Numerous microvilli were present within the follicular lumen while around the lumina, junctional specializations including gap junctions were positive for the connexin 43 protein. A nonuniform distribution of the connexin 43-positive sites were observed. Small or dot-shaped positive sites were noted where two clusters of cells were connected; the cells were identified as S-100 cells. Double immunohistochemical staining of the connexin 43 and growth hormone (GH) or connexin 43 and luteinizing hormone (LH) was also performed, demonstrating no direct relationship between the connexin 43 and either the GH or LH cells. These findings indicate that there are two kinds of messages necessary for the hormone release in the pituitary gland. One is via the portal vein system, the other is through the gap junction-mediated networks of folliculo-stellate cells. The granulated cells directly associate with cell membrane of folliculo-stellate cells are able to discharge secretory granules through communication via gap junctions, while those granulated cells that are more distant from the folliculo-stellate cells are only able to discharge hormones via the pituitary hormone-releasing hormone from the portal vein system.     

S-100 protein positive human T-lymphocyte

S-100 protein was detected in a small number of human peripheral T-lymphocytes by a direct immunoperoxidase method with the use of monospecific antibody to S-100 protein. Complemented-mediated lysis using monoclonal antibodies revealed that the S-100+ T-lymphocytes bore OKT3, OKT8, and OKT11 antigens but not OKT4, OKM1, HLA-DR, HNK1 (Leu-7) antigens on their surface. Immunoelectron micrography showed that S-100 T-lymphocytes were small lymphocytes with poorly developed cellular organelles. These findings clearly indicated that S-100+ T-lymphocytes belonged to the OKT8+ T-cell subset, the so-called suppressor/cytotoxic T-cell subset. Although the function of the S-100+ T-lymphocytes is unclear, S-100 protein may be a useful cytoplasmic marker for the subdivision of the heterogeneous OKT8+ lymphocyte population.     

胚胎小肠S-100+树突状细胞的组织分布

目的：观察人胚胎小肠树突状细胞(dendritic cells,DCs)的组织分布。方法：应用SABC免疫组织化学法对人胚胎小肠DC的出现时间、分布部位、形态以及数量等进行研究。结果：(1)人胚胎小肠各段S-100^ DC于第9～11W相继出现,主要分布于粘膜固有层,外形不规则,第24W以后,其突起相连逐渐在固有层形成网状结构。(2)回肠集合淋巴小结S-100^ DC以滤泡问区数量最多,其外形相对规则。结论：人胚胎小肠S-100^ DC主要分布于固有层,其数量随胎龄的增加而逐渐增加,而回肠集合淋巴小结S-100DC呈区域性分布,它们与固有层S-DC在形状、大小和数量上有所不同。     

S-100 protein immunostaining in teratomatous well-differentiated tissues

The presence and distribution of S-100 protein were studied in a case of ovarian teratoma using avidin-biotin complex immunoperoxidase method. S-100 immunoreactivity within the well-differentiated teratomatous tissues appeared to mirror that of their normally developed human counterparts, although we could unexpectedly detect S-100 immunoreactivity in bone osteoblasts and osteocytes, and in tooth germ odontoblasts. Choroid plexus-like formations present in the teratoma were also positive. Our results suggest that the presence of S-100 protein might be associated with a basic cell function regardless of the presence of a physiologically end-developed human organism.     

不同月龄大鼠垂体前叶滤泡星形细胞S100蛋白的表达

目的:观察不同月龄大鼠垂体重量、垂体前叶3类细胞比例及滤泡星形细胞(FS细胞)S100蛋白表达的形态学变化。方法:选取2~3月(青年组)、10~12月(中年组)、18~20月(老年组)3组大鼠垂体经分析天平称重后,行HE染色和免疫组化ABC法观察垂体前叶S100蛋白的表达。结果:中年组垂体重量最大;垂体前叶嫌色细胞(其中多为滤泡星形细胞)所占比例以中年组最高(39.26%±0.10%);3年龄组S100蛋白阳性细胞的分布方式不同;细胞阳性率以中年组最高(27.13%±0.16%),与其它两组比较有显著差异。结论:中年组大鼠垂体重量、垂体前叶FS细胞的数量、分布与其它两组比较变化最大。在大鼠垂体前叶增龄过程中,FS细胞发挥着重要作用。     

S-100 immunoreactive cells in non-nervous duck tissues

S-100 protein was detected in endocrine cells of the islet of Langerhans, hypophysis, ultimobranchial body, proventriculus, gizzard and intestine, and epithelial cells of the interlobular bile duct, gall bladder, renal tubules and epididymal and urinary ducts except for the nerve elements in the duck. Sertoli cells and oocytes were also S-100-protein immuno-reactive. The types of S-100-protein-positive cells detected in the duck differ from those of mammalian species.     

Immunocytochemical localization of the brain-specific S-100 protein in the pituitary gland of adult rat

Summary The brain-specific S-100 protein was localized at the electron microscopic level in the anterior and posterior pituitary gland of adult rat by indirect immunoperoxidase histology. The protein was found in the stellate cells of the pars distalis and tuberalis, in the marginal cells that line the hypophyseal cleft and in the glia-like cells, the pituicytes, of the neural lobe. The pituicytes, the stellate cells and the marginal cells have in common at least two properties: they all express a brain-specific marker and they are satellite cells to the secretory axons in the neural lobe and of the secretory cells in the adenohypophysis. These properties suggest that the S-100 cells in the pituitary gland are neuroectodermal in origin, possibly glial in nature.     

S-100 protein immunopositivity in human nontumorous hypophyses and pituitary adenomas

The presence, distribution, and morphological appearance of S-100 protein-immunoreactive cells in the human hypophysis were studied by immunocytochemistry. One hundred and twelve nonadenomatous pituitaries from fetuses to adults and pituitaries affected by several lesions including metastases, acute infarcts, and lymphocytic hypophysitis, as well as 115 pituitary adenomas were examined.S-100 protein immunoreactivity was detected in neurohy-pophyseal pituicytes and stellate cells of the pars distalis from 5 months following birth. In adults, S-100 protein-immunopositive cells displayed a preferential topographical association with growth hormone-, follicle-stimulating hormone-, luteinizing hormone-, and alpha-sub-unit-immunoreactive cells and with capillary walls. Colloid-containing follicles were mainly lined by hormone-containing cells, although scattered S-100 protein-immunoreactive processes or cell bodies were also observed forming their walls.No major changes in S-100 protein-immunoreactive cells were observed in the pituitary parenchyma bordering metastatic, inflammatory, necrotic, or adenomatous tissues. Eighteen of 115 pituitary adenomas contained a variable number of S-100 protein-immunoreactive cells. No preferential association of these cells with any type of pituitary adenoma was found.We propose that S-100 protein expression in the nontumorous adenohypophysis and pituitary adenomas may constitute a dynamic process and that S-100 protein-positive cells may constitute a heterogeneous cell population composed of pure, fully differentiated stellate cells and of transdifferentiated follicular cells.     

S-100 protein positive cells in nasopharyngeal carcinoma (NPC): Absence of prognostic significance

Summary An immunohistochemical study of S-100 protein in 43 nasopharyngeal carcinomas (NPC) of known clinical evolution (33 primary and 10 metastatic) is presented. Sixty per cent of primary site cases as well as all metastatic forms showed S-100 protein positive cells intermingled with tumour cells. These S-100 positive elements were identified as Langerhans cells. No significant differences were found when correlating S-100 protein positivity and histological NPC variants, neither in age nor in sex of patients. Statistical analysis failed to demonstrate any positive correlation between S-100 protein reactivity and clinical survival.     

垂体腺瘤中垂体激素与S-100蛋白免疫组化双重染色观察

目的：探讨滤泡星状细胞在垂体腺瘤分类中的意义及滤泡星状细胞与内分泌细胞之间的关系。方法：应用免疫组化双重染色方法,对４２ 例人重体腺瘤的垂体激素与 Ｓ１００ 蛋白表达进行对照观察。结果：垂体腺瘤组织中的滤泡星状细胞有两种情况,一种为腺瘤组织中可见散在分布的滤泡星状细胞,并可见１ 个瘤细胞既有 Ｓ１００ 蛋白表达,又含激素分泌颗粒;另一种为滤泡星状细胞构成了腺瘤的一种主要的细胞成分。结论：滤泡星状细胞与内分泌细胞的功能密切相关,可能在调整内分泌细胞的产生和激素释放方面起一定的作用;滤泡星状细胞腺瘤应作为垂体无功能腺瘤的一个单独类型。     

The structure and function of folliculo-stellate cells in the anterior pituitary gland.

The folliculo-stellate cells (FS cells) in the anterior pituitary gland are characterized by their star-like appearance and their ability to form follicles. Although FS cells do not produce any pituitary hormones, their special tendency to surrounding endocrine cells with their long cytoplasmic processes suggests that they regulate endocrine cells by intercellular communication. In spite of many morphological and cytophysiological studies recently performed, a precise understanding of the major functions of FS cells in the pituitary gland remains obscure. We review here the morphological characteristics of FS cells and their suspected functions in the anterior pituitary gland. It is well established that the FS cell produces many kinds of growth factors, i.e., fibroblast growth factor, vascular endothelial cell growth factor and interleukin 6. The biological significances of these growth factors in the anterior pituitary gland are also discussed in this paper. The origin and differentiation of FS cells, especially the possibility that the FS cell is a kind of stem cell which has the potential to differentiate into endocrine cells, is also presented.     

Immunocytochemistry of folliculo-stellate cells of normal and neoplastic human pituitary gland.

Five normal human pituitaries and 20 pituitary neoplasms were investigated by immunocytochemical methods. Glial fibrillary acidic protein and S100 have been shown in the anterior lobe of the pituitary. Both these markers were present in the folliculo-stellate cell. Evidence is presented for the presence of a transitional folliculo-stellate cell which is immunoreactive for S100. The role of the folliculo-stellate cell is discussed.     

Neurospecific S-100 protein in synaptosomes of the rat cerebral cortex

A nonspecific S-100 protein was found in the composition of low-molecular-weight acid proteins from synaptosomes of the rat cerebral cortex by capillary microdisc electrophoresis in 15% polyacrylamide gel with 0.1% sodium dodecysulfate and with the aid of a highly purified marker protein. The S-100 protein accounted for 15–20% of the lowmolecular-weight acid synaptosomal proteins.Research Institute of Experimental Medicine, Academy of Medical Sciences of the USSR, Leningrad. (Presented by Academician of the Academy of Medical Sciences of the USSR V. S. Il'in). Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 2, pp. 164–166, February, 1976.     

S-100 protein in soft-tissue tumors derived from Schwann cells and melanocytes.

In soft tissues outside the central nervous system, S-100 protein is found normally only in Schwann cells. Using the peroxidase-antiperoxidase immunohistochemical method S-100 was also found in tumors derived from Schwann cells and melanocytes, including neurofibromas, neurilemomas, granular cell myoblastomas, cutaneous nevi, and malignant melanomas. S-100 was not detected in malignant Schwannomas, neuroblastomas, oat cell carcinomas, medullary carcinomas of the thyroid, paragangliomas, or meningiomas. S-100 was also absent from neoplasms of soft tissues not usually considered to arise from cells of neural crest origin. S-100 appears to be a useful marker for identifying neoplasms derived from Schwann cells and melanocytes.     

Counts of S-100 positive epidermal dendritic cells in Kveim test skin biopsies

S-100 positive epidermal dendritic cells were counted in skin biopsies from 48 Kveim tests and four known foreign-body reactions. Counts in histologically positive Kveim biopsies (mean 11.3 per 200 basal cells) were significantly higher than in either negative biopsies (5.1; P less than 0.001) or foreign-body reactions (4.7; P less than 0.05). A similar difference was found, irrespective of the histological appearances, between biopsies from patients diagnosed clinically as having sarcoidosis (10.5) and those in which another diagnosis had been made (4.1; P less than 0.001). In biopsies from patients with sarcoidosis 70% had a positive Kveim test, 70% had a raised epidermal dendritic cell count and one or the other was positive in 90%. All cases in which both the Kveim test was positive and the dendritic cell count was raised had a final clinical diagnosis of sarcoidosis. Counts of S-100 positive epidermal dendritic cells are useful in differentiating positive reactions to Kveim suspension from non-specific reactions to foreign material and increase the diagnostic confidence of the Kveim test.     

Immunoelectronmicroscopic demonstration of S-100 protein in hairy cell leukemia cells

Hairy cell leukemia (HCL) is generally considered a neoplastic proliferation of B-cell lineage. Among immunocompetent cells, however, S-100 protein is also demonstrated in "dendritic" cells (i.e., interdigitating reticulum cells, Langerhans cells, follicular dendritic cells) and in a small percentage of T8-cells. This study reports the surprising detection of S-100 protein in peripheral blood HCL cells of B-cell type, using immunofluorescence and immunoelectronmicroscopy. However, negative results for S-100 protein staining were obtained in paraffin splenic sections of HCL cases. This report stresses the need for caution in the interpretation of immunocytochemical methods and results, and emphasizes the diagnostic ambiguity of the S-100 protein.     

正常人腺垂体和垂体腺瘤中滤泡星状细胞的免疫组织化学研究

Significance of the appearance of folliculo-stellate cells (FSC) was studied in 59 human adenohypophyses and 58 pituitary adenomas after being stained with anti-S100 protein and 6 anti-pituitary hormone antibodies. S100 protein positive cells, stellate in shape with expending cytoplasmic processes among endocrine cells (EC) appeared in all the human adenohypophyses and had a tendency to be clustered in small groups characterized by gathering of 3 to 5 cells in the alveoli. Age or sex difference seemed to have no influence on the distributive density of FSC. FSC in the pituitary adenomas may be derived from two origins. One was the residue of normal pituitary tissue left in adenomas, and the other one seemed to be the chief component of the tumor, known as folliculo-stellate cell adenoma.     

Immunohistochemical expression of S-100 protein in human embryonal fat cells

The aim of the present study was to investigate immunocytochemically the presence of S-100 protein in subcutaneous fat cells during early human embryogenesis (6-12 weeks of gestation). We found that preadipocytes in the subcutaneous tissue which were at different stages of differentiation were positive for S-100 protein. The other cells in the embryonal subcutis (mesenchymal cells differentiating into fibroblasts and fibrocytes and endothelial cells) showed a negative reaction for S-100. Our results imply that the S-100 protein is expressed from the beginning of lipidogenesis and possibly acts as a factor regulating lipid storage and body fat formation. It can be used as a reliable biochemical marker of human fat cell differentiation and for distinguishing them from the mesenchymal and the fibroblast cells in the human embryonal subcutis.