Search results for "EPITHELIUM"
showing 10 items of 505 documents
Subtypes of non-transformed human mammary epithelial cells cultured in vitro: histo-blood group antigen H type 2 defines basal cell-derived cells.
1993
Normal (non-transformed) human mammary epithelial cell lines derived from reduction mammoplasties were analyzed by immunocytochemistry with more than 80 monoclonal antibodies (mAbs) and other specific reagents to tissue-specific and developmentally regulated antigens at different passage levels. A subpopulation of poorly differentiated, proliferating epithelial cells, corresponding to the 'selected' cell type of late passages, is shown to be characterized by a new marker, the histo-blood group antigen H type 2, probably carried on a membrane-bound glycolipid. These cells also express a number of other onco-developmental carbohydrate antigens [Le(y), Le(x), sialosyl-Le(a), precursor of Thoms…
The transcription factor ZEB1 (deltaEF1) promotes tumour cell dedifferentiation by repressing master regulators of epithelial polarity.
2007
Epithelial to mesenchymal transition (EMT) is implicated in the progression of primary tumours towards metastasis and is likely caused by a pathological activation of transcription factors regulating EMT in embryonic development. To analyse EMT-causing pathways in tumouri-genesis, we identified transcriptional targets of the E-cadherin repressor ZEB1 in invasive human cancer cells. We show that ZEB1 repressed multiple key determinants of epithelial differentiation and cell–cell adhesion, including the cell polarity genes Crumbs3, HUGL2 and Pals1-associated tight junction protein. ZEB1 associated with their endogenous promoters in vivo, and strongly repressed promotor activities in reporter …
Involvement of caspase-3 and GD3 ganglioside in ceramide-induced apoptosis in Farber disease.
2000
Farber's disease (FD) is a rare genetic disorder caused by ceramidase deficiency, which results in ceramide accumulation in lung, liver, colon, skeletal muscle, cartilage, and bone. Although this disease has been symptomatically characterized, little is known about its molecular pathogenetic process. Because recent studies reported that ceramide accumulation induces GD3 ganglioside formation and apoptosis, we investigated, in tissue obtained via colonoscopy from seriously involved patients, the possible involvement of ceramide in FD colonocyte destruction. Histochemical and TUNEL analyses of paraffin-embedded sections revealed that 45 ± 4.3% of FD colonocytes showed morphological signs of …
ICAM-1 and α3β1 expression by bronchial epithelial cells and theirin vitromodulation by inflammatory and anti-inflammatory mediators
2000
Background: Adhesion molecules are involved in inflammatory and repair processes of the bronchial epithelium. ICAM-1 is mainly involved in inflammatory reactions, whereas integrins, such as α3β1, are mainly involved in repair processes. Methods: Using bronchial biopsies from 10 asthmatics and eight controls, we first evaluated by immunohistochemistry expression of α3β1 and ICAM-1 in intact and damaged epithelium. Then, using the human pulmonary epithelial cell line WI-26 VA, we studied, by flow-cytometry, the modulation of ICAM-1 and α3β1 expression, and, by ELISA, the release of fibronectin by proinflammatory cytokines, such as IL-5, and anti-inflammatory cytokines, such as IL-4, TGF-β, an…
Correlation of " in vivo" microcirculation and degeneration of the basal cells of the epithelium in lingual lichen planus
2010
Background: Oral lichen planus is an inflammatory chronic disease with an autimmune pathogenesis and unknown etiology that affects oral mucosa, with or without the involvement of the skin and other mucous membranes. The principal histological characteristics are the degeneration of the basal cell layer and the abnormal infiltration of inflammatory cells into the subepithelial layer of connective tissue. Objectives: This study is aimed to appraise if lingual lichen planus (LLP) is sustained by alteration of the oral microcirculation and if this abnormal vascularisation increases the degeneration of basal keratinocytes and the disruption of the basement membrane. Materials and Methods: Fiftee…
Leptin and leptin receptor expression in asthma.
2009
Background The adipokine leptin is a potential new mediator for bronchial epithelial homeostasis. Asthma is a chronic inflammatory disease characterized by airway remodeling that might affect disease chronicity and severity. TGF-β is a tissue growth factor the dysregulation of which is associated with airway remodeling. Objective We sought to determine whether a bronchial epithelial dysfunction of the leptin/leptin receptor pathway contributes to asthma pathogenesis and severity. Methods We investigated in vitro the presence of leptin/leptin receptor on human bronchial epithelial cells. Then we studied the effect of TGF-β and fluticasone propionate on leptin receptor expression. Finally, th…
Metabolic adaptation in the human gut microbiota during pregnancy and the first year of life
2018
Abstract Background The relationship between the gut microbiome and the human host is dynamic and we may expect adjustments in microbiome function if host physiology changes. Metatranscriptomic approaches should be key in unraveling how such adjustments occur. Methods We employ metatranscriptomic sequencing analyses to study gene expression in the gut microbiota of infants through their first year of life, and of their mothers days before delivery and one year afterwards. Findings In infants, hallmarks of aerobic metabolism disappear from the microbial metatranscriptome as development proceeds, while the expression of functions related to carbohydrate transport and metabolism increases and …
Erratum to: Donor age and long-term culture do not negatively influence the stem potential of limbal fibroblast-like stem cells
2016
In regenerative medicine the maintenance of stem cell properties is of crucial importance. Ageing is considered a cause of reduced stemness capability. The limbus is a stem niche of easy access and harbors two stem cell populations: epithelial stem cells and fibroblast-like stem cells. Our aim was to investigate whether donor age and/or long-term culture have any influence on stem cell marker expression and the profiles in the fibroblast-like stem cell population.Fibroblast-like stem cells were isolated and digested from 25 limbus samples of normal human corneo-scleral rings and long-term cultures were obtained. SSEA4 expression and sphere-forming capability were evaluated; cytofluorimetric…
Notch‐1 signaling activation sustains overexpression of interleukin 33 in the epithelium of nasal polyps
2019
Abstract BACKGROUND: Alterations in the nasal epithelial barrier homeostasis and increased interleukin 33 (IL-33) expression contribute to the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP). AIMS: As Notch-1 signaling is crucial in repair processes of mucosa, the current study assessed Notch-1/Jagged-1 signaling and IL-33 in the epithelium of nasal polyps biopsies from allergic (A-CRSwNP; n = 9) and not allergic (NA-CRSwNP; n = 9) subjects by immunohistochemistry. We also assessed, in a model of nasal epithelial cells, the effects of stimulation of Notch-1 with Jagged-1 on the expression of IL-33 (by flow cytometry, immunofluorescence, and immunocytochemistry), Jagged-1 (…
An experimental model for the exposure of human ciliated cells to sulfur dioxide at different concentrations
1994
Mucociliary transport is an important nonimmunological defense mechanism of the respiratory tract. The aim of this study was to investigate the effect of sulfur dioxide (SO2) at different concentrations on ciliary beat frequency (CBF). Ciliated cells were obtained from 12 volunteers by nose brush. CBF was quantified using video-interference microscopy. The cells were placed on a polycarbonate membrane in contact with the surface of a reservoir filled with RPMI 1640 (bicarbonate buffered) or Ringer's (electrolyte) solution, allowing the cells to be supplied by capillarity. In an exposure chamber the cells were exposed for 30 min to SO2 2.5-12.5 ppm at 37 degrees C and 100% air humidity. SO2 …