Subcapsular Epithelial Cells Research Articles

Observation on the occurrence of after-cataract after lensectomy keeping anterior capsule intact

Objective To observe the incidence of after-cataract after lensectomy reserving anterior capsule intact during lensovitrectomy. Methods Eighty-nine eyes of 83 patients with vitreoretinal diseases and cataract received lensovitrectomy. First the posterior capsule, cortex and nucleus of the lens were resected by the cutting head of vitrectomy unit and the equatorial capsule and anterior capsule were preserved. Then the anterior subcapsular lens epithelial cells were removed by cutting head with negative pressure of 30-50 mmHg (1 mmHg = 0.133 kPa)before vetrectomy. All patients were followed up for 10-20 months after the operation. Results In 89 eyes with reserving anterior capsule lensectomy combined with vitrectomy, the reserved anterior capsule was transparent in 86 eyes accounting for 96.63%; after-cataract occurred in 2 eyes accounting for 2.25%; the anterior capsular ruptured in 1 eye accounting for 1.12%. Conclusion In keeping anterior capsule intact lensectomy, the incidence of after-cataract is very low after the anterior subcapsular lens epithelial cells be removed. Key words: Vitrectomy; Lensectomy, anterior capsule keeping; Lens epithelial cells, anterior subcapsular; Cataract, after

Thymic Carcinoma with Cartilage Formation in a Dog

An 11-year-old female Chihuahua exhibited respiratory distress and a computed tomography scan showed a large mass in the anterior thoracic cavity. During surgery, it was found that the mass was strongly adherent to surrounding tissue. A histopathological examination of a biopsy sample from the mass revealed proliferation of atypical epithelial cells and cartilage formation admixed with mature lymphocytes. Immunohistochemically, the tumour cells, as well as the normal canine thymic epithelial cells, were positive for pan-cytokeratin (CK), CK5/6, CK19, p63 and bone morphogenetic protein (BMP) 6. Foci of cartilage tissue were formed in association with the neoplastic epithelial tissue. In the normal canine thymus, the subcapsular epithelial cells are positive for both CK19 and BMP6. These findings indicate that the cartilage element within the tumour developed from CK19-positive neoplastic epithelial cells, which were derived from the thymic subcapsular epithelium. This case represents a novel variant of canine thymic epithelial tumour that exhibits cartilage differentiation.

GM-CSF induces podoplanin expression during dendritic cell differentiation (111.56)

Abstract Podoplanin is a mucin-type transmembrane glycoprotein containing extensive Oglycosylation in extracellular domain and two phosphorylation sites in a short cytoplasmic tail. It is expressed in kidney glomerular epithelial cells, lymphatic endothelium and subcapsular epithelial cells in murine thymus. Recently, podoplanin was found on murine F4/80 positive peritoneal macrophages and human follicular dendritic cells (FDCs) indicating that podoplanin is involved in immune response. We have reported that podoplanin is induced during Th9 and Th17 polarization. Here, we studied podoplanin expression on different types of murine myeloid cells. We found that podoplanin was not detectable on circulating and bone marrow derived neutrophils, monocytes, basophils and esinophils, its expression level on neutrophil and monocytes was not inducible followed by fMLP or TNF-a stimulation. Podoplanin was also not detectable on spleen and lymph node resided CD11b+macrophages, CD11c+ dendritic cells (cDCs) and CD8+ plasmacytoid dendritic cells (pDCs). However, podoplanin expression level has been dramatically increased on GM-CSF driven bone marrow-derived dendritic cells. These data suggest that podoplanin can be induced during GM-CSF driven dendritic cell differentiation, indicating that podoplanin may be a transient marker during dendritic cells differentiation and maturation. The mechanism of GM-CSF induced podoplanin and it significance need to be further investigated.

Common immunophenotypic features of submandibular salivary glands and thymus in rats

Submandibular salivary gland is a part of the neuro-immune-endocrine system. It contains biological factors which regulate a number of functions in the body including the modulation of thymus function. The aim of the study was to investigate immunophenotypic characteristics of submandibular salivary glands of rats during ontogenesis, using the panels of monoclonal antibodies and to compare with the phenotypic characteristics of epithelial components of the thymus. Submandibular salivary glands and thymus were obtained from 1, 30 and 60 days old male AO (Albino, Oxford) rats. Streptavidin-biotin peroxidase method was used for staining. Immunohistochemical analysis of rat submandibular salivary glands showed phenotypic heterogeneity of particular components of this gland during the postnatal development. We demonstrated that rat submandibular salivary glands share common antigens with rat thymic epithelial cells, but the observed phenotypic similarity between the individual regions was considered much more significant. Our data showed that the phenotypic similarity between duct epithelial cells and subcapsular epithelial cells and most medullary cells, whereas cortical epithelial cells are phenotypically similar to acinar cells. This immunohistological study showed phenotypic complexity of the submandibular salivary gland and similarity to the thymus that opens new perspectives in studying phenotypic similarities between this gland and lymphatic organs.

Podoplanin is involved in Th17 cell polarization (113.17)

Abstract Podoplanin is a mucin-type transmembrane glycoprotein containing extensive O-glycosylation in extracellular domain and two phosphorylation sites in a short cytoplasmic tail. It is expressed in kidney glomerular epithelial cells, lymphatic endothelium and subcapsular epithelial cells in murine thymus. Recently, podoplanin was found on F4/80 positive peritoneal macrophages, indicating that podoplanin is involved in immune response. However, the physiologic function of podoplanin is still unknown. To study whether podoplanin is involved in adaptive immunity, we measured its expression on lymphocyts. The data showed that podoplanin was not detectable on freshly isolated T and B lymphocytes from peripheral blood, spleen and thymus, its expression is also non-inducible after stimulation with PMA, Concanavalin A or LPS. Surprisingly, we found that the podoplanin expression on CD4+ cells was dramatically increased after 3 days culture with Th17 polarization medium compose of immobilized CD3/CD28, IL-6, IL-4, TGFb, IFN-r and IL-23, which showed more than 60% cells were podoplanin positive. However, its expression is not able to be induced on Th1 and Th2 polarized cells. By detecting IL-17 production, we interestingly found that the IL-17+ cells can be divided into podplaninhigh and podoplaninlow populations. The significance of the differential expression on Th17 cells needs to be further investigated.

Age-Associated Changes in the Cornea, Lens and Retina of the Albino Rat Eye: A Histological and Immuno-Histochemical Study

Background: Age-related changes occur throughout the body including vision. Aging has various effects on the visual system affecting both external and internal portions of the eye. Age-related visual deterioration may be due to both neural and optical factors. Aim of the Work: To study the normal histological changes of aging on the cornea, lens and retina of albino rat eye. Materials and Methods: In this study twenty-four male albino rats were used. They were divided into Two groups: Group (1) young-aged group (3-6 months) and Group (2) old-aged Group (22-26 months). All animals were sacrificed and their eye balls were extracted and prepared for light microscopic examination. Immuno-histochemical stain was also added to detect apoptosis. Results: It was revealed that aging induced various histological changes in the eye of albino rat. The cornea showed irregular surface with atrophy of the epithelial cells and wide separation of corneal lamellae with loss of keratocytes. The lens subcapsular epithelial cells appeared few and disarranged. The cortical lens fibers lost their nuclei. The retina showed diminished retinal thickness, damage of some ganglion cells and retinal pigmented epithelial cells. The outer nuclear layer revealed marked diminution of its thickness with small dark nuclei. Rods and cones showed decreased density. The Bruch's membrane appeared illdefined and irregular with some adherent deposits and blood leakage in the choriocapillaries. The immunohistochemical stain revealed appearance of some apoptotic cells in the cornea, lens subcapsular epithelial cells and ganglion cell layer as well as pigment epithelial cells of the retina in old-aged rats. Conclusion:Normal aging is associated with some histological and immuno-histochemical changes that could explain the visual impairment observed in elderly

Histopathological study of retrolental membranes secondary to persistent hyperplastic primary vitreous

To study the pathological characteristics of retrolental membranes (RLMs) secondary to persistent hyperplastic primary vitreous (PHPV), and to discuss the possible pathogenesis of PHPV. Experimental study. Six RLMs obtained from six patients with PHPV during vitrectomy were examined by light microscopy (HE & PAS staining). All of them were observed with proliferating cell nuclear antigen (PCNA) immunostaining, together with collagen I, factor VIII related antigen, smooth muscle actin (SMA), epithelial membrane antigen (EMA), neuron specific enolase (NSE) and glial fibrillary acidic protein (GFAP) staining. Apoptosis were detected by terminal deoxynucleotidyl transferase-mediated deoxyuridine 5-triphosphate nick-end labeling (TUNEL). Light microscopy showed that the RLM was a dense connective tissue with numerous inflammatory cells including mast cells and lymphocytes. PAS staining showed that RLMs contained a larger amount of polysaccharides. Histopathology and immunohistochemistry showed that there were vascular channels, smooth muscle cells, nervous cells and epithelial cells scattered in RLMs. Collagen I was the main component of RLMs. PCNA-positive nuclei were widely found in RLMs. TUNEL-positive nuclei were also found in all RLMs, as well as in the posterior subcapsular epithelial cells of lens. The cell types of RLMs secondary to PHPV are similar to those of the primary vitreous. It is possible that the mechanism of the progression of RLMs is the over-development and incomplete regression of the retrolental vascular system. Inflammation may play an important role in the regression of RLMs.

The effects of TiO_2 nano thin film on the migration and adherence of BLEC in vitro

Objective The generate of posterior capsular opacification(PCO)is associated with the adhensive and migration of residual subcapsular lens epithelial cells(LECs).Titanium dioxide(TiO_2)nanometer is proved to have the ability of killing tumor cells and cultured bovine LECs.This study tried to observe the effects of TiO_2 nanometer thin film provoked by light on adhesiveness and migration of bovine LECs in vitro.MethodsThe fresh bovine lenses were obtained and cultured in DMEM containing 10% of newborn bovine serum.The second to fifth generation of cells were used in this experiment.The slide modified by TiO_2 photocatalyst film was prepared by sol-gel method.Cultured cells were seeded in filmed or unfilmed slides respectively and exposed to ultraviolet(wavelength 365 nm)for 20 or 40 minutes.The contact angle between water drop and slide was measured by droping method and the cells adhered to slides were calculated after 24 and 48 hours of culture.The growth status and migration distance of bovine LECs were assayed and compared between filmed and unfilmed groups.ResultsThe contact angle between water drop and slide was 0°±2°and 18.825°±2.342° in filmed and unfilmed group respectively,indicating a obviously smaller contact angle in TiO_2 filmed group than unfilmed one.The numbers of bovine LECs adhered to filmed slide was considerably reduced in TiO_2 filmed group compared with unfilmed group in different UVA exposure time(t_(0 min)=5.492,P=0.001;t_(20 min)=6.031,P=0.000;t_(40 min)=6.828,P=0.000).However,no significant difference was found in the numbers of adhensive cells among 3 UVA irradiation time points(F=1.278,P=0.297).The migration distance of the cells was significantly shorter in TiO_2 filmed group in comparison with unfilmed group in 24 and 48 hours after UVA irradiation(F_(group)=14.965,P=0.000;F_(time)=38.033,P=0.000).ConclusionThe TiO_2 nanometer thin film is characterized by the superhydrophilic property.So it can effectively impede the adhesion and migration of bovine LECs in vitro. Key words: lens epithelium cell; after cataract; titanium dioxide; photocatalyst film

Spatial, a gene expressed in thymic stromal cells, depends on three-dimensional thymus organization for its expression.

Although the importance of thymic stroma in thymopoiesis has been recognized, the underlying molecular details regarding stromal cell biology remain obscure. To study this area, we have cloned genes expressed in thymic stromal cells. Spatial is alternatively spliced to generate two mRNAs in thymus and lymph node (LN) but it is not expressed in the spleen. In mouse embryos, the short form begins expression at day 10 while the long form is not detected until day 12. Both mRNAs encode proline rich proteins and their closest homology is to homeobox and POU domain transcription factors. Spatial is not expressed in thymocytes, but it is expressed in 2-deoxyguanosine-treated day 14 fetal thymic organ culture (FTOC) and in reaggregated FTOC. These data suggest that a normal three-dimensional organization of stromal cells is required for Spatial expression. An antiserum raised against a C-terminal peptide detected proteins of 38 and 32 kDa in Western blots of total thymus proteins. In frozen thymus sections, subcapsular epithelial cells were stained with the anti-Spatial antiserum. Paracortical subcapsular cells of unknown function were also stained in the LN. Both forms of Spatial fused to the green fluorescent protein (GFP) localize to the nucleus in transfected cells.

Epithelial cell-specific laminin 5 is required for survival of early thymocytes.

The gene LamC2 encoding the gamma2 chain of laminin 5, an epithelial cell-specific extracellular matrix protein, was identified in a PCR-based subtracted cDNA library from mouse thymic stromal cells. The mRNA existed in two alternative forms (5.1 and 2.4 kb). The full-length message was highly expressed in SCID thymus and in a nurse cell line, but not in other thymic epithelial cell lines, while the short form was more widely expressed. In situ hybridization and immunohistochemical staining revealed laminin 5 expression mostly in the subcapsular region of the adult thymus. Addition to fetal thymic organ cultures of a cell adhesion-blocking mAb to the alpha3 chain of laminin 5 interrupted T cell development. There was a 40% reduction in the total yield of thymocytes, and the most profound decrease (75-90%) was seen in the CD25+CD44+ and CD25+CD44-subsets of the CD4-CD8- double negative fraction. Most of the surviving double negative thymocytes expressed Sca-1, and there were significant increases in the number of cells with CD69 expression and in the fraction of annexin V-stained cells. None of these changes were observed with a nonblocking anti-laminin alpha3 chain mAb. These results suggest that the interaction between double negative thymoctyes and laminin 5 made by subcapsular epithelial cells is required for the survival and differentiation of mouse thymocytes.

Semiquantitative Morphological Analysis of Stromal Cells the Irradiated and Recovering Rat Thymus.

To understand the roles of thymic stromal cells in T-lymphocyte development, we semiquantitatively analysed rat thymi recovering from irradiation (6 Gy), using a transmission electron microscope. The most striking findings were that the percentage of subcapsular epithelial cells significantly increased in the cortex on day 3 after irradiation compared with the control; the percentage of intermediate epithelial cells significantly increased in the cortex on days 3 and 5 after irradiation and in the medulla on days 5 and 7 compared with the control; the interdigitating cells disappeared from the medulla by day 7 after irradiation and reappeared on day 9. The present data thus reveal that during recovery after irradiation (6 Gy), marked changes occur in the relative proportions of different epithelial cell subtypes in the cortex and medulla of the rat thymus. In addition, the percentages of macrophages and interdigitating cells also changed during the recovery. These changes, which may be associated with the abrupt proliferation of thymocytes after irradiation, should shed light on the significance of stromal cells in the T cell development.

Role of the Perivascular Epithelium in the Histogenesis of Hassall's Corpuscles

Thirteen human thymuses and one thymoma were morphologically and immunohistologically investigated to define the histogenesis of Hassall's corpuscles (HCs). The following monoclonal antibodies: antisquamous cytokeratin on paraffin sections and TE-4 and TE-8 on frozen sections, were used to show the distribution of the epithelial components; PAL-E on frozen and anti-CD31 and anti-CD34 on paraffin sections detected the endothelial cell distribution. In the thymoma, epithelial onion-like structures, looking like true HCs, were found to originate from the perivascular epithelium lining dilatated spaces and some of them partially obliterated the space where the blood capillary showed thickened wall and endothelial regressive changes. Antisquamous cytokeratin stained: (1) in the thymus: subcapsular, medullary, and HC epithelial cells; (2) in the thymoma: epithelial cells lining the perivascular spaces and forming HCs. TE-4 stained: (1) in the thymus: the subcapsular and medullary epithelium; (2) in the thymoma: the epithelium lining the perivascular spaces and epithelial cells forming HCs. TE-8 stained: (1) in the thymus: HCs only; (2) in the thymoma: HCs and perivascular epithelial cells. PAL-E, CD31, and CD34, which specifically react with endothelial cells, stained remnants of capillary structures in the core of some HCs. The results indicate that: (1) corpuscular structures in thymoma originate from perivascular epithelium; (2) thymus medullary epithelial cells stained by cytokeratin and TE-4 correspond to perivascular epithelial cells whose staining is well documented in thymoma; (3) the subcapsular-perivascular epithelium and HCs represent different steps of differentiation of a single ectodermal cell lineage; (4) the PAL-E-, CD31-, and CD34-positive reaction in the core of some HCs suggests that the perivascular epithelium would be stimulated to transform into HCs as a consequence of endothelial changes with fragmentation of the capillary included in the perivascular space.

Cyclosporin A-induced changes of the thymic microenvironment. A review of morphological studies.

Cyclosporin A is an immunosuppressive drug, which disrupts the activation of peripheral T-lymphocyte pool and blocks the maturation of thymocytes within the thymus. Normally, thymic nonlymphoid cells provide the optimal inductive microenvironment for development of T-lymphocytes. After application of cyclosporin A the complex alterations of the thymic microenvironment occur, affecting all types of nonlymphoid cells. All subsets of thymic epithelial cells are thoroughly changed. The subcapsular epithelial cells show the prominent enlargement of cytokeratin contents. In electron microscopy, however, these cells present the morpho-functional aspect of resting cells. The epithelial cells in deeper cortex become enlarged and stockier, whereby their cell processes appear more ramified and thicker. Thus, the cytoreticulum they create seems much denser. These cells strongly express MHC antigens. Their subcellular organization is suggestive of increased synthetic and secretory activity. The number of medullary epithelial cells is decreased. The cells with the most mature phenotype are the most prominently depleted and the ones with phenotypically and morphologically immature appearance predominate. The number of Hassall's bodies is also decreased. The number of cortical macrophages does not increase. However, these cells become enlarged showing the prominent changes in enzyme capacity, histochemical features and ultrastructural organization. Thus, they become similar to macrophages located in the cortico-medullary zone of the normal rat thymus. Cortical macrophages increase the activity of hydrolytic enzymes, acid phosphatase and nonspecific esterase, develop the strong activity of chloroacetate esterase, the strong activity of respiratory enzyme succinic dehydrogenase and begin to show the marked presence of prostaglandin synthase. Moreover, the cytoplasmic inclusions, which are aldehyde fuchsin- and PAS-positive and show sudanophilia, appear within cortical macrophages. In electron microscopy these cells show an abundant cytoplasm a very active appearance and the variety of vacuolar cytoplasmic inclusions. The mitoses of neighboring thymocytes are often seen. The number of interdigitating cells is decreased due to reduced size of thymic medulla, but these cells do not show the substantial phenotype changes. The description and classification of all types of nonlymphoid cells, which constitute the normal thymic microenvironment, is also presented. The functional significance and possible mechanisms of CSA-induced changes of the thymic microenvironment are discussed.

Differential effect of cyclosporin application on epithelial cells of the rat thymus. Immunohistochemical study

Young adult male Wistar rats were given 30 mg per kg of cyclosporin (CS) for 21 consecutive days. A panel of monoclonal antibodies was used to study the phenotype of thymic epithelial cells. After treatment with CS, subcapsular epithelial cells, although phenotypically similar to medullary epithelial cells, were changed in a similar manner to phenotypically distinct epithelial cells of the deep cortex. These cells became enlarged, stockier and their cytoplasmic prolongations were thicker and coarser compared with control cells and their number was not decreased. In contrast, the number of medullary epithelial cells was markedly reduced, whereby the cells with the most mature phenotype (CK8 +10 −19 − and CK8 +10 +19 −) were the most prominently depleted. No proliferation of thymic epithelial cells was detected as monitored by incorporation of 5-bromodeoxyuridine.

Post‐hatching development of the thymic epithelial cells in the rainbow trout Salmo gairdneri: An ultrastructural study

This study reports the ultrastructure of subpopulations of epithelial cells of the thymic parenchyma during the post-hatching development of the rainbow trout, Salmo gairdner, kept at 14 degrees C. At hatching, the thymus contained a small number of medium and large thymocytes interspersed among three different types of epithelial cells: (1) epithelial cells adjacent to the connective tissue capsule; (2) ramified dark epithelial cells with electron-dense cytoplasm; and (3) pale electron-lucent epithelial cells displaying secretory-like features. All these cells types were anchored to one another by desmosomes and had apparently differentiated from the pharyngeal epithelium. At 4 days after hatching, the thymus enlarged, and numerous gaps occurred between the cell processes of contiguous epithelial cells adjacent to the capsular connective tissue. In 21-day-old trout, thymic trabeculae developed carrying blood vessels, and a subcapsular zone became evident containing lymphoblasts and large subcapsular epithelial cells. In 30-day-old trout, an outer thymic zone developed consisting of spindle-shaped epithelial cells which formed a dense network. At this stage, scattered cystic cells, which apparently differentiated from the pale epithelial cells, were present.

Effect of interferon‐gamma and tumor necrosis factor‐alpha on lymphoepithelial interactions within thymic nurse cells

Isolated thymic nurse cells (TNC) represent a specialized microenvironment in vivo where thymocytes interact specifically with subcapsular epithelial cells. They are thought to play a critical role in the process of T cell differentiation. We demonstrate that recombinant murine interferon-gamma and recombinant human tumor necrosis factor-alpha can act on these interactions: they stimulate TNC-derived epithelial cells to establish interactions with thymocytes in vitro and to form new lymphoepithelial complexes. This phenomenon is partially inhibited by anti-Ia monoclonal antibodies. Implications of these findings for normal intrathymic differentiation are discussed.

Immunohistochemical studies in human thymomas. Localization of thymosin and various cell marker.

Forty five human thymomas were studied immunohistochemically using antibodies to thymosin x-1, thymosin beta-3, cortical epithelium of human thymus (UH-1), mouse thymic nurse cells (Th-3) and Leu-7. Most thymomas were found to contain thymosin x-1 (80%) and thymosin beta-3 (89%). Also used in the study were a new monoclonal antibody (UH-1), which reacts with the epithelial cells forming a meshwork in the cortex of the normal newborn thymus and Leu 7, which reacts with subcapsular epithelial cells in the outer thymic cortex. The combined use of UH-1 and Leu-7 was found to identify neoplastic epithelial cells of thymic cortical origin in thymomas. Approximately 80% (37/45) of the thymomas in the present study reacted with Leu-7, UH-1 or both antibodies, and were thus considered to be derived from cortical thymic epithelium. Of the eight thymomas which were negative with both Leu-7 and UH-1, four were histologically of mixed type characterized by the formation of epithelial cell islands. All four of these thymomas were positive with thymosin and were therefore considered to be of medullary origin. Ten of the thymoma were associated with myasthenia gravis; all were positive with UH-1 and were consider to be of cortical origin.

Cloning of human thymic subcapsular cortex epithelial cells with T-lymphocyte binding sites and hemopoietic growth factor activity.

The thymic microenvironment involves complex cell interactions among different types of epithelial cells, macrophages, tissue histiocytes, and immature and maturing T cells. We describe the isolation of a subset of thymic epithelial cells by selective primary culture followed by cotransfection with a simian virus 40 replication-origin-defective mutant and pSV2neo plasmid. The cloned cells have the composite immunophenotype that is unique to thymic subcapsular epithelial cells, suggesting that they may provide a model system in vitro for analyzing the earliest steps in T-cell differentiation. This possibility is supported by the finding that these epithelial cells express LFA-3-associated binding sites for T cells, secrete a macrophage hemopoietic growth factor, and synergize with macrophages in the production of interleukin 1.

Accumulation of fibrillar protein in the aging human lens capsule, with special reference to the pathogenesis of pseudoexfoliative disease of the lens.

Filaments staining with chrome hematoxylin accumulate in the preequatorial region of the aging lens capsule. Their electron microscopic, histochemical, and tinctorial properties indicate that they consist of fibrillar protein banded at 500 Angstrom intervals, which is similar to, if not identical with the material characteristically occupying a similar zone of the capsule in pseudoexfoliative disease of the lens. It is therefore considered that the subcapsular epithelial cells of the preequatorial region synthesize a fibrillar protein (seen as filaments by light microscopy) in the majority of aging persons, and that in a few, the excessive accumulation of this material results in pseudoexfoliative disease.