The ability of inflammatory bronchoalveolar leucocyte populations elicited with microbes or mineral dust to injure alveolar epithelial cells and degrade extracellular matrix in vitro.

Inflammatory cells are recruited to the parenchyma of the lung in a range of conditions where they are considered to have the ability to exert damaging effects on elements of the alveolus. The injurious effects of rat bronchoalveolar-derived inflammatory cells on an alveolar Type II epithelial cell line were therefore assessed. Inflammatory populations produced by intratracheal injection of Corynebacterium parvum or quartz caused non-lethal detachment injury to the epithelial cells on co-culture whereas control bronchoalveolar cells had no effect on epithelial cells. The pathogenic mineral dusts quartz and chrysotile asbestos caused increased detachment injury when added to co-cultures of epithelial cells and bronchoalveolar leucocyte populations; neither titanium dioxide, a control mineral dust, nor zymosan were active in this respect. Detachment injury was particularly marked when quartz was added to co-cultures of epithelial cells and inflammatory bronchoalveolar cells from quartz treated lung. On the basis of anti-protease and anti-oxidant studies, the detachment injury was found to be mediated by protease alone in the case of quartz cells and protease plus oxidant in the case of C. parvum cells. The two inflammatory bronchoalveolar cell populations were found to have increased proteolytic activity, compared to control bronchoalveolar cells, as shown by increased ability to degrade fibronectin, laminin and denatured collagen. Inflammatory bronchoalveolar cells therefore have the potential to attack elements of the septal extracellular matrix as well as to compromise the integrity of the alveolar epithelium.     

The ability of inflammatory bronchoalveolar leucocyte populations elicited with microbes or mineral dust to injure alveolar epithelial cells and degrade extracellular matrix in vitro

Inflammatory cells are recruited to the parenchyma of the lung in a range of conditions where they are considered to have the ability to exert damaging effects on elements of the alveolus. The injurious effects of rat bronchoalveolar-derived inflammatory cells on an alveolar Type II epithelial cell line were therefore assessed. Inflammatory populations produced by intratracheal injection of Corynebacterium parvum or quartz caused non-lethal detachment injury to the epithelial cells on co-culture whereas control bronchoalveolar cells had no effect on epithelial cells. The pathogenic mineral dusts quartz and chrysotile asbestos caused increased detachment injury when added to co-cultures of epithelial cells and bronchoalveolar leucocyte populations; neither titanium dioxide, a control mineral dust, nor zymosan were active in this respect. Detachment injury was particularly marked when quartz was added to co-cultures of epithelial cells and inflammatory bronchoalveolar cells from quartz treated lung. On the basis of anti-protease and anti-oxidant studies, the detachment injury was found to be mediated by protease alone in the case of quartz cells and protease plus oxidant in the case of C. parvum cells. The two inflammatory bronchoalveolar cell populations were found to have increased proteolytic activity, compared to control bronchoalveolar cells, as shown by increased ability to degrade fibronectin, laminin and denatured collagen. Inflammatory bronchoalveolar cells therefore have the potential to attack elements of the septal extracellular matrix as well as to compromise the integrity of the alveolar epithelium.     

Testicular Stromal Tumor: Ultrastructural,Immunohistochemical, and Gel Electrophoretic Evidence of Epithelial Differentiation

A testicular tumor, removed from a 52-year-old man, was composed of uniform spindle cells and abundant interposed collagen, and was histologically diagnosed as a stromal tumor. Electron microscopy revealed cords of cells sometimes surrounded by a basal lamina. Desmosome-like junctions were found between some cells, and immunostaining for desmoplakins was positive. Immunofluorescence studies also showed cytokeratin-positivity in most and vimentin-positivity in some of the tumor cells. The presence of typical simple epithelial cytokeratins of M, 40000, 45000 and 52000 was revealed by the western blotting method.

Cytokeratin positivity in the tumor cells suggests the epithelial nature of this mesenchymal-looking tumor. The tumor might arise from cytokeratin-positive epithelial elements of the testis or its covering mesothelium, but the histogenesis remains unresolved. Our findings suggest that some of the so-called testicular stromal tumors may in fact be of epithelial nature by presenting features typical of epithelial differentiation.     

Testicular Stromal Tumor: Ultrastructural, Immunohistochemical, and Gel Electrophoretic Evidence of Epithelial Differentiation

A testicular tumor, removed from a 52-year-old man, was composed of uniform spindle cells and abundant interposed collagen, and was histologically diagnosed as a stromal tumor. Electron microscopy revealed cords of cells sometimes surrounded by a basal lamina. Desmosome-like junctions were found between some cells, and immunostaining for desmoplakins was positive. Immunofluorescence studies also showed cytokeratin-positivity in most and vimentin-positivity in some of the tumor cells. The presence of typical simple epithelial cytokeratins of M, 40000, 45000 and 52000 was revealed by the western blotting method.

Cytokeratin positivity in the tumor cells suggests the epithelial nature of this mesenchymal-looking tumor. The tumor might arise from cytokeratin-positive epithelial elements of the testis or its covering mesothelium, but the histogenesis remains unresolved. Our findings suggest that some of the so-called testicular stromal tumors may in fact be of epithelial nature by presenting features typical of epithelial differentiation.     

Fibroadenoma of the female breast with multinucleated giant cells

A fibroadenoma in the female breast is described, which contained multiple multinucleated giant cells within the stroma. The investigation indicated the giant cells to be of epithelial nature, caused by epithelial degeneration secondary to myoepithelial swelling of unknown cause. Their presence and morphology could cause anxiety about malignancy, but this was found groundless.     

锶矿泉水对人肾小管上皮细胞增殖及ATP酶活性的影响*

背景：一定浓度的锶对人体健康有益,锶对人体多种细胞的增殖和酶活性有影响。 目的：用不同浓度的锶矿泉水配制的培养基在体外培养人肾小管上皮细胞,观察细胞增殖情况及Na+-K+-ATP酶的活性。 方法：体外培养人肾小管上皮细胞,用普通DMEM液体培养基(高糖)培养24 h后,分别用含锶质量浓度2,4,6,8 mg/L的矿泉水和双蒸水的条件培养基继续培养,分别于48,72,96和110 h行MTT法观察HK-2细胞的增殖情况。培养110 h的细胞以比色法测无机磷的量来判断Na+-K+-ATP酶的活性。 结果与结论：MTT结果表明：质量浓度2 mg/L锶矿泉水对HK-2细胞增殖无影响;细胞培养至110 h,双蒸水组出现生长抑制时,质量浓度4,6,8 mg/L锶矿泉水组却依然能保持旺盛的增殖状态(P < 0.05),生长周期延长,尤以质量浓度4 mg/L锶矿泉水组的效果最突出(P < 0.05)。Na+-K+-ATP酶活性测试结果表明：与双蒸水组比较,锶矿泉水组Na+-K+-ATP酶活性更高(P < 0.05),其中质量浓度6 mg/L锶矿泉水组的酶活性最强(P < 0.05)。结果证实,锶矿泉水可延长肾小管细胞的增殖周期,可促进肾小管细胞的转运功能。关键词：锶;肾小管细胞;增殖;ATP酶;矿泉水;浓度;组织工程 doi:10.3969/j.issn.1673-8225.2012.15.031     

Immunohistochemical studies on the phenotype of murine and human thymic stromal cell lines

Four different murine and human thymic stromal cell (TSC) lines were analyzed by means of indirect immunofluorescence for the presence of tissue specific intermediate filament proteins, extracellular matrix products and thymic hormone. Among these cell lines, only one (IT-45R1) was shown to be epithelial in nature, as revealed by its immunoreactivity with antikeratin antibodies. In addition, IT-45R1 cells (but not the other cell lines) produced thymulin--a well defined thymic hormone--that was detected intracellularly and in the culture medium. Concerning extracellular matrix elements, we noted that all TSC lines were able to produce basement membrane proteins as type IV collagen and fibronectin. Type I collagen however was synthesized by TEPI, HT-5 and HT-7 cells but not by IT-45R1 cells. Our data demonstrate that only the IT-45R1 TSC line is epithelial and active in thymic hormone production. The other three TSC lines are not epithelial in nature, but their definitive phenotypes remain to be determined.     

Europium-doped bioapatite: a new photostable biological probe,internalizable by human cells

The authors prepared at low temperatures (37 degrees C) a novel inorganic bioprobe. It consisted of mineral nanoparticles of apatitic tricalcium phosphate doped with europium, of size, structure and composition close to those of the mineral part of calcified tissues. In contrast to organic probes which degrade rapidly (photobleaching), the red luminescence of the new probe is photostable. Moreover, this luminescence can be obtained under visible irradiation, which makes it suitable for prolonged examination of live cells. Human pancreatic epithelial cells in culture were incubated with these particles and their internalization was observed by laser scanning confocal microscopy. Transmission electron microscopy and electron microdiffraction analysis confirmed that the particles were internalized retaining their original apatitic structure. This probe may thus be of value for biovectorization.     

Mesenchymal-epithelial differentiation of adamantinoma of long bones: an immunohistochemical and ultrastructural study

Three cases of adamantinoma were studied by electron microscopy and immunohistochemistry. In the tubular pattern, well-differentiated epithelial cells and glandular structures were present, in addition to ill-defined glands. In the basaloid pattern, less differentiated epithelial cells with discohesion were seen in the central epithelial masses. This study established the epithelial nature of some tubular structures with slit-like lumina, easily misinterpreted as capillaries by light microscopy. Results also showed that the irregular spaces observed within the basaloid pattern probably result from cell discohesion. Moreover, this investigation demonstrates the epithelial nature of a subset of spindle cells within the stroma of adamantinoma and offers ultrastructural evidence for a probable mesenchymal-epithelial transformation as its histogenesis.     

DNA aberrations in the epithelial cell component of adamantinoma of long bones.

Adamantinoma of long bones is a rare malignant tumor composed of cells with epithelial characteristics in various differentiation patterns surrounded by fibrous cells. Evidence as to whether this neoplasm should be designated as an epithelial bone tumor or a biphasic sarcoma with both epithelial and mesenchymal features is lacking. In this study the nature of the mesenchymal and epithelial components of adamantinoma was investigated by DNA flow cytometry, DNA image cytometry, p53 immunohistochemistry, and polymerase chain reaction-based loss of heterozygosity detection at the p53 locus. Specimens from 6 of 15 patients (40%) analyzed by flow cytometry had an aneuploid DNA index. Image cytometry analysis of Feulgen-stained paraffin sections of 6 aneuploid and 2 diploid tumors revealed that aneuploid nuclei were detected in cells with an epithelial phenotype only, whereas all fibrous cells were diploid. Immunohistochemistry for p53 on specimens from 25 patients revealed moderate or strong immunoreactivity in 12 tumors (48%) restricted to the epithelial cells. Loss of heterozygosity at the p53 locus could be confirmed in the epithelial component of an immunohistochemically p53-positive tumor. Additionally, sections of 7 lung metastases were studied histologically. Only keratin-positive epithelial cells, predominantly in the spindle cell pattern, were present in these metastases, whereas the osteofibrous tissue present in the primary tumors was not detected. These results suggest that either adamantinoma consists of a malignant epithelial part with a reactive osteofibrous stroma or that the malignant epithelial cells develop next to a proliferating benign fibrous component. Additional analysis of common genetic abnormalities in the fibrous and epithelial cells of adamantinoma is therefore indicated.     

Augmentation of mitogen responsiveness in human lymphocytes by a humoral factor obtained from thymic epithelial cultures.

Supernatants derived from thymic epithelial cultures were studied for their effect in augmenting mitogen responsiveness in human thymocytes and lymphocytes. Incubation of these cells for 20 hr in diluted supernatants obtained from 14 to 25 day old cultures of thymic epithelium resulted in a significant increase in the response to Con A. The epithelial nature of the cells was confirmed by electron microscopy. Supernatants from fibroblast cultures or thymic epithelial cultures overgrown by fibroblasts were not effective, nor were supernatants from secondary epithelial outgrowths. The molecular weight of the active fraction appeared to be between 17,000 and 45,000 daltons. The data indicated that human thymus epithelium produced one or more humoral factors which were identical to, or shared properties with, thymic hormones.     

In vitro adherence of Escherichia coli to endometrial epithelial cells of rats and influence of estradiol.

The influence of ovarian hormones on the adhesion of Escherichia coli to endometrial epithelial cells was investigated in an in vitro system. Endometrial cells liberated by collagenase from rat uteri were used. Optimal test conditions were obtained when 5 X 10(8) E. coli bacteria were added to 10(5) epithelial cells and incubated for 60 min. The adhesion of the organisms was inhibited by the addition of either mannose or alpha-methyl-D-mannopyranoside. When epithelial cells collected from uteri of estradiol-treated rats were used, the number of E. coli adhering to the cells was markedly lower than that adhering to epithelial cells collected from control rats. These results suggest that E. coli adheres to endometrial epithelial cells with so-called type 1 pili and that estradiol alters the nature of the endometrial epithelium and prevents the adherence of the organisms to the cells.     

Selective culture of epithelial cells from primary breast carcinomas using irradiated 3T3 cells as feeder layer

The main drawback of the selective culture of human mammary epithelial cells from primary breast cancer is the overgrowth of tumor-associated stromal fibroblasts. This drawback may be overcome by using, in primary culture, lethally irradiated 3T3 cells which act as a feeder layer to maintain tumor-derived epithelial cell proliferation. These 3T3 cells, exposed to 60 Gy at confluence, form a specific cellular substrate which constitutes an obstacle to fibroblast attachment. Enzyme-disaggregated breast cells from six primary breast carcinomas were cocultured over lethally irradiated but living 3T3 cells. The method led to the purification of tumor-derived epithelial cells from all six cancer samples, and long-term culture was obtained in one. The epithelial nature of these purified tumor-derived epithelial cells was demonstrated by their general morphology and by the expression of cytokeratins and Epithelial Membrane Antigen. These results confirm the stimulatory effect of a this stromal feeder layer on breast epithelial cell growth and show that this stromal feeder layer can also control the fibroblast overgrowth. Our results provide an alternative approach in the selective culture of epithelial cells from primary breast carcinoma.     

DISTINCTIVE ADHESION PATHWAYS ARE INVOLVED IN EPITHELIOTROPIC PROCESSES AT DIFFERENT SITES

Intraepithelial migration of lymphoid cells (epitheliotropism) is a biological process that can be observed under various physiological and pathological conditions. Recently, epitheliotropism was proposed to be a multi-step process, involving interactions of lymphoid cells with both epithelial basement membrane (EBM) and epithelial cells. In the present study we analysed by immunohistochemistry the adhesion mechanisms that are potentially involved in epitheliotropism of lymphoid cells in various disorders, such as tonsillar hyperplasia, coeliac disease, malignant lymphomas of mucosa-associated lymphoid tissue (MALTomas), and mycosis fungoides (MF). The combinations of adhesion molecules expressed on the participating lymphoid and epithelial cells varied among these disorders. These findings suggest the adhesion pathways utilized in epitheliotropism may be associated with the nature of the lymphoid cell (reactive or neoplastic/B or T) and/or the site of the epithelium involved. In some cases the specificity of the process was determined by the adhesion mechanism involved in the lymphocyte–EBM interaction, as in the case of α3β1 integrin/laminin-5 in MF, and in others by the adhesion mechanisms involved in the interaction between lymphoid and epithelial cells, such as α4 integrin/VCAM-1 in tonsillar hyperplasia and αEβ7/E-cadherin in coeliac disease.     

The thymus in the mouse changes its activity during pregnancy: a study of the microenvironment

The mouse thymus changes dramatically during pregnancy. It shrinks in size, and the cortex is extensively reduced from midpregnancy onwards. Despite this, there is surprisingly little evidence for any increase in apoptosis, and considerable evidence that mitosis of thymocytes continues throughout pregnancy. In spite of overall involution the thymic medulla actually expands in midpregnancy due to a combination of mitosis of epithelial cells and an accumulation of lymphocytes. The extent and nature of these changes are examined in this study at the ultrastructural level. The epithelial cells of the subcapsular cortex (type 1 cells) become wrinkled and exhibit powers of phagocytosis, whilst the other cortical epithelial cells are relatively unchanged, although the formation of epithelial/thymocyte rosettes and thymic nurse cells is more clearly seen in midpregnancy than usual. Other changes associated with pregnancy involve the medullary epithelial cells that undergo an increased level of mitosis. Their greater numbers surround accumulations of lymphocytes to form the characteristic medullary epithelial rings. Cell movement through blood vessel walls was clearly observed in midpregnancy, but not at other times. Interdigitating cells in the medulla become more conspicuous as pregnancy proceeds and the cells become phagocytic. The endoplasmic reticulum in plasma cells becomes expanded, indicating increased secretory activity. These results highlight the active nature of the thymus in pregnancy in spite of its involution. This picture contradicts the conventional notion that an involuted thymus is inactive.     

The phenotype of bovine corneal epithelial cells on chitosan membrane

Corneal wound healing is one of the major issues in ocular surface reconstruction and ocular surface diseases. Amniotic membrane (AM) transplantation is an excellent treatment modality to promote corneal wound healing and treat corneal diseases. It is interesting and valuable to search for another synthetic and biocompatible substitute for the study of mechanism of AM and the treatment of ocular surface disorders. Chitosan, the second-most abundant polymer in nature, has many biological advantages such as biocompatibility, biodegradability, hemostatic activity, and wound-healing property to be used as biomedical applications. The purpose of this project is to evaluate the phenotype of cultured corneal epithelial cells in vitro on synthetic chitosan membrane (CM). We cultivated bovine corneal epithelial cells on CM and AM, and then evaluated their phenotypes. The viability of the respective cell cultures was investigated using the 3-[4,5-dimethylrhiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay. The cytotoxicity of CM and AM to corneal epithelial cells was evaluated by lactate dehydrogenase (LDH) assay. The morphology of cultivated corneal epithelial cells on CM and AM was observed by scanning electron microscopy. Additionally, immunocytochemical stainings were used to confirm the phenotype of corneal epithelial cells. In MTT and LDH assays we found that the CM can support the growth of cultured corneal epithelial cells in good condition with minimal toxicity. The SEM and immunohistocytochemistry showed that the phenotype of corneal epithelial cells is compatible with that of AM. We conclude that the CM has the potential to be a suitable biomaterial for treating ocular surface disorders.     

Multilocular renal cyst. Scanning and transmission electron microscopic observations

A multilocular renal cyst in a boy aged one year and four months is presented, with particular attention being paid to the nature of the epithelial lining cells. Light and transmission electron microscopy showed the cyst to be lined by a single layer of flattened or cuboidal epithelial cells of relatively uniform morphology. Neither embryonic elements nor nephroblastomatous foci were noted in the intervening stroma. The scanning electron microscopy showed hitherto undescribed surface morphological features of the epithelial lining cells: They were characterized by the presence of one or, occasionally two centrally positioned long cilia and by variably oriented microvilli. The observations presented here suggested that the lining cells of the cyst most closely resembled the principal cells of the collecting ducts, especially those located in the inner medulla of the kidney. An unexpected finding was the additional occurrence of a giant bullous lesion in the right lung of this patient.     

Expression of HLA antigens by human thymic epithelial cells

Human thymuses were examined by tissue section staining with antibodies specific for monomorphic and polymorphic HLA-A, B, C, and DR determinants. The principal cell type expressing high levels of HLA antigens has the distribution of epithelial cells. Immunoelectron microscopy confirmed their epithelial nature. As in the mouse, both medullary and cortical epithelial cells express high levels of class II (DR) antigens, a finding that is remarkable in that these antigens were originally thought to be restricted to lymphoid and accessory cells. Class I (A, B, and C) antigens are also present on thymic epithelial cells. They are easily detectable on medullary epithelial cells, but two distinct patterns of cortical straining were observed. One group of antibodies produced intense dendritic staining throughout the cortex: the other group produced only faint or no corticol dendritic staining at all. These different staining patterns do not correlate with known properties of the antibodies and thus appear to be due to intrinsci properties of the different A, B, and C antigens.     

Characterization of human thymic epithelial cells grown in serum-free medium

Thymic epithelial cells have a critical influence on T-cell differentiation. In order to characterize these cells in humans, a serum-free growth medium was developed for their long-term culture. Important components of this medium included transferrin, epidermal growth factor, prostaglandin E1, and selenious acid. The presence of a keratin cytoskeleton, tonofilaments, and desmosomes confirmed the epithelial nature of these cells. Indirect immunofluorescence study of these epithelial cells demonstrated the presence of Ia and B-2 microglobulin antigens. The availability of highly enriched thymic epithelial cultures should simplify the functional characterization of this cell.