Search results for "Epithelial cell"
showing 10 items of 475 documents
Corneal Epithelial Stem Cells-Physiology, Pathophysiology and Therapeutic Options.
2021
In the human cornea, regeneration of the epithelium is regulated by the stem cell reservoir of the limbus, which is the marginal region of the cornea representing the anatomical and functional border between the corneal and conjunctival epithelium. In support of this concept, extensive limbal damage, e.g., by chemical or thermal injury, inflammation, or surgery, may induce limbal stem cell deficiency (LSCD) leading to vascularization and opacification of the cornea and eventually vision loss. These acquired forms of limbal stem cell deficiency may occur uni- or bilaterally, which is important for the choice of treatment. Moreover, a variety of inherited diseases, such as congenital aniridia…
Endothelial cells and normal breast epithelial cells enhance invasion of breast carcinoma cells by CXCR-4-dependent up-regulation of urokinase-type p…
2008
Here we show the increase of invasion of three breast cancer cell lines (8701-BC, MDA-MB-231 and SKBR3) upon long-term co-incubation with culture medium of normal microvascular endothelial cells (MVEC) and normal breast epithelial cells (HB2). The enhancement of invasion relied on the interaction of microvascular endothelial cell and normal breast epithelial cell CXCL12 (SDF1) chemokine, whose expression by breast cancer cells was very low, with the cognate CXCR4 receptor of malignant cells, which resulted in over-expression of the urokinase-type plasminogen activator receptor (uPAR) on their surfaces. uPAR over-expression, showed by RT-PCR and Western blotting, was paralleled by increased …
Xanthine dehydrogenase processes retinol to retinoic acid in human mammary epithelial cells
2008
Retinoic acid is considered to be the active metabolite of retinol, able to control differentiation and proliferation of epithelia. Retinoic acid biosynthesis has been widely described with the implication of multiple enzymatic activities. However, our understanding of the cell biological function and regulation of this process is limited. In a recent study we evidenced that milk xanthine oxidase (E.C. 1.17.3.2.) is capable to oxidize all-trans-retinol bound to CRBP (holo-CRBP) to all-trans-retinaldehyde and then to all-trans-retinoic acid. To get further knowledge regarding this process we have evaluated the biosynthetic pathway of retinoic acid in a human mammary epithelial cell line (HME…
Characterization of a Naturally Occurring Breast Cancer Subset Enriched in Epithelial-to-Mesenchymal Transition and Stem Cell Characteristics
2009
Abstract Metaplastic breast cancers (MBC) are aggressive, chemoresistant tumors characterized by lineage plasticity. To advance understanding of their pathogenesis and relatedness to other breast cancer subtypes, 28 MBCs were compared with common breast cancers using comparative genomic hybridization, transcriptional profiling, and reverse-phase protein arrays and by sequencing for common breast cancer mutations. MBCs showed unique DNA copy number aberrations compared with common breast cancers. PIK3CA mutations were detected in 9 of 19 MBCs (47.4%) versus 80 of 232 hormone receptor–positive cancers (34.5%; P = 0.32), 17 of 75 HER-2–positive samples (22.7%; P = 0.04), 20 of 240 basal-like c…
The polypyrimidine tract-binding protein (PTB) is involved in the post-transcriptional regulation of human inducible nitric oxide synthase expression.
2006
Human inducible nitric oxide synthase (iNOS) expression is regulated by transcriptional and post-transcriptional mechanisms. We have recently shown that the multifunctional RNA-binding proteins KH-type splicing regulatory protein and tristetraprolin are critically involved in the post-transcriptional regulation of human iNOS expression. Several reports have shown that KH-type splicing regulatory protein colocalizes with the polypyrimidine tract-binding protein (PTB), and both RNA-binding proteins seem to interact with the same mRNAs. Therefore we analyzed the involvement of PTB in human iNOS expression. In human DLD-1 cells, cytokine incubation necessary to induce iNOS expression did not ch…
IFN-gamma-induced protein 10 is a novel biomarker of rhinovirus-induced asthma exacerbations
2007
BACKGROUND: Rhinovirus-induced acute asthma is the most frequent trigger for asthma exacerbations. OBJECTIVE: We assessed which inflammatory mediators were released from bronchial epithelial cells (BECs) after infection with rhinovirus and then determined whether they were also present in subjects with acute virus-induced asthma, with the aim to identify a biomarker or biomarkers for acute virus-induced asthma. METHODS: BECs were obtained from bronchial brushings of steroid-naive asthmatic subjects and healthy nonatopic control subjects. Cells were infected with rhinovirus 16. Inflammatory mediators were measured by means of flow cytometry with a cytometric bead array. Subjects with acute a…
STAT3 links IL-22 signaling in intestinal epithelial cells to mucosal wound healing.
2009
Signal transducer and activator of transcription (STAT) 3 is a pleiotropic transcription factor with important functions in cytokine signaling in a variety of tissues. However, the role of STAT3 in the intestinal epithelium is not well understood. We demonstrate that development of colonic inflammation is associated with the induction of STAT3 activity in intestinal epithelial cells (IECs). Studies in genetically engineered mice showed that epithelial STAT3 activation in dextran sodium sulfate colitis is dependent on interleukin (IL)-22 rather than IL-6. IL-22 was secreted by colonic CD11c+ cells in response to Toll-like receptor stimulation. Conditional knockout mice with an IEC-specific d…
Activation of Intestinal Epithelial Stat3 Orchestrates Tissue Defense during Gastrointestinal Infection
2015
Gastrointestinal infections with EHEC and EPEC are responsible for outbreaks of diarrheal diseases and represent a global health problem. Innate first-line-defense mechanisms such as production of mucus and antimicrobial peptides by intestinal epithelial cells are of utmost importance for host control of gastrointestinal infections. For the first time, we directly demonstrate a critical role for Stat3 activation in intestinal epithelial cells upon infection of mice with Citrobacter rodentium - a murine pathogen that mimics human infections with attaching and effacing Escherichia coli. C. rodentium induced transcription of IL-6 and IL-22 in gut samples of mice and was associated with activat…
Conjunctival Sac Fluid Contains Elevated Levels of Soluble TRAIL: Implications for the Anti-Tumoral Surveillance of the Anterior Surface of the Eye
2008
Little is known on the ability of different epithelia to release soluble TNF-related apoptosis-inducing ligand (TRAIL) and the relevance of TRAIL secretion by epithelial cells is still incompletely understood. On these bases, we have measured the concentration of soluble TRAIL by ELISA in the conjunctival sac fluid. It was the highest ever detected in a biological fluid (mean value of 26,800 pg/ml), being approximately 20-fold greater than that found in human saliva and >200-fold greater than that detected in human serum. On the other hand, osteoprotegerin, the soluble decoy receptor of TRAIL, was almost undetectable in the conjunctival sac fluid. Of note, the levels of soluble TRAIL measur…
Resveratrol-induced xenophagy promotes intracellular bacteria clearance in intestinal epithelial cells and macrophages
2019
International audience; Autophagy is a lysosomal degradation process that contributes to host immunity by eliminating invasive pathogens and the modulating inflammatory response. Several infectious and immune disorders are associated with autophagy defects, suggesting that stimulation of autophagy in these diseases should be bene ficial. Here, we show that resveratrol is able to boost xenophagy, a selective form of autophagy that target invasive bacteria. We demonstrated that resveratrol promotes in vitro autophagy-dependent clearance of intracellular bacteria in intestinal epithelial cells and macrophages. These results were validated in vivo using infection in a transgenic GFP-LC3 zebra f…