Search results for "Epithelial cell"

Structural and regulatory functions of keratins.

2007

The diversity of epithelial functions is reflected by the expression of distinct keratin pairs that are responsible to protect epithelial cells against mechanical stress and to act as signaling platforms. The keratin cytoskeleton integrates these functions by forming a supracellular scaffold that connects at desmosomal cell-cell adhesions. Multiple human diseases and murine knockouts in which the integrity of this system is destroyed testify to its importance as a mechanical stabilizer in certain epithelia. Yet, surprisingly little is known about the precise mechanisms responsible for assembly and disease pathology. In addition to these structural aspects of keratin function, experimental e…

Estradiol decreases xanthine dehydrogenase enzyme activity and protein expression innon-tumorigenicand malignant human mammary epithelial cells

2009

The retinoic acid deficiency in breast tumour epithelial cells has been ascribed to an insufficient expression of either the enzyme(s) involved in its biosynthesis or the cellular retinol binding protein (CRBP) or both. In an attempt to define the mechanisms underpinning retinoic acid deficiency in these cell model systems, we have investigated the potential regulatory effect of oestrogen (17β-estradiol) on one key player in retinoic acid biosynthesis, the xanthine dehydrogenase (XDH). This enzyme is consistently expressed and very active in non-malignant human mammary epithelial cells (HMEC), as opposed to tumour MDA-MB231 and MCF7 cells. In these latter two cell lines, as opposed to HMEC …

Cellular interactions ofCandida albicanswith human oral epithelial cells and enterocytes

2010

The human pathogenic fungus Candida albicans can cause systemic infections by invading epithelial barriers to gain access to the bloodstream. One of the main reservoirs of C. albicans is the gastrointestinal tract and systemic infections predominantly originate from this niche. In this study, we used scanning electron and fluorescence microscopy, adhesion, invasion and damage assays, fungal mutants and a set of fungal and host cell inhibitors to investigate the interactions of C. albicans with oral epithelial cells and enterocytes. Our data demonstrate that adhesion, invasion and damage by C. albicans depend not only on fungal morphology and activity, but also on the epithelial cell type an…

Evidence for a common progenitor of epithelial and mesenchymal components of the liver

2013

Tissues of the adult organism maintain the homeostasis and respond to injury by means of progenitor/stem cell compartments capable to give rise to appropriate progeny. In organs composed by histotypes of different embryological origins (e.g. The liver), the tissue turnover may in theory involve different stem/precursor cells able to respond coordinately to physiological or pathological stimuli. In the liver, a progenitor cell compartment, giving rise to hepatocytes and cholangiocytes, can be activated by chronic injury inhibiting hepatocyte proliferation. The precursor compartment guaranteeing turnover of hepatic stellate cells (HSCs) (perisinusoidal cells implicated with the origin of the …

Temporal Monitoring of Differentiated Human Airway Epithelial Cells Using Microfluidics

2015

The airway epithelium is exposed to a variety of harmful agents during breathing and appropriate cellular responses are essential to maintain tissue homeostasis. Recent evidence has highlighted the contribution of epithelial barrier dysfunction in the development of many chronic respiratory diseases. Despite intense research efforts, the responses of the airway barrier to environmental agents are not fully understood, mainly due to lack of suitable in vitro models that recapitulate the complex in vivo situation accurately. Using an interdisciplinary approach, we describe a novel dynamic 3D in vitro model of the airway epithelium, incorporating fully differentiated primary human airway epith…

EGF converts transit-amplifying neurogenic precursors in the adult brain into multipotent stem cells.

2002

AbstractNeural stem cells in the subventricular zone (SVZ) continue to generate new neurons in the adult brain. SVZ cells exposed to EGF in culture grow to form neurospheres that are multipotent and self-renewing. We show here that the majority of these EGF-responsive cells are not derived from relatively quiescent stem cells in vivo, but from the highly mitotic, Dlx2+, transit-amplifying C cells. When exposed to EGF, C cells downregulate Dlx2, arrest neuronal production, and become highly proliferative and invasive. Killing Dlx2+ cells dramatically reduces the in vivo response to EGF and neurosphere formation in vitro. Furthermore, purified C cells are 53-fold enriched for neurosphere gene…

An essential switch in subunit composition of a chromatin remodeling complex during neural development.

2007

Summary Mammalian neural stem cells (NSCs) have the capacity to both self-renew and to generate all the neuronal and glial cell-types of the adult nervous system. Global chromatin changes accompany the transition from proliferating NSCs to committed neuronal lineages, but the mechanisms involved have been unclear. Using a proteomics approach, we show that a switch in subunit composition of neural, ATP-dependent SWI/SNF-like chromatin remodeling complexes accompanies this developmental transition. Proliferating neural stem and progenitor cells express complexes in which BAF45a, a Kruppel/PHD domain protein and the actin-related protein BAF53a are quantitatively associated with the SWI2/SNF2-…

Variable Release of Interleukin-8 after Hyperosmolar Exposure of Bronchial Epithelial Cell Lines.

2009

Gliadin, zonulin and gut permeabilità: effects on celiac and non-celiac intestinal mucosa and intestinal cell lines.

2006

Objective. Little is known about the interaction of gliadin with intestinal epithelial cells and the mechanism(s) through which gliadin crosses the intestinal epithelial barrier. We investigated whether gliadin has any immediate effect on zonulin release and signaling. Material and methods. Both ex vivo human small intestines and intestinal cell monolayers were exposed to gliadin, and zonulin release and changes in paracellular permeability were monitored in the presence and absence of zonulin antagonism. Zonulin binding, cytoskeletal rearrangement, and zonula occludens-1 (ZO-1) redistribution were evaluated by immunofluorescence microscopy. Tight junction occludin and ZO-1 gene expression …

Mitochondrial compartment: a possible target of cadmium effects on breast epithelial cells.

2009

Cadmium–breast epithelial cell interactions were studied by analyzing some mitochondria-related aspects of stress response. We treated immortalized non-tumor breast cells with 5 or 50 μM CdCl2 for 24 or 96 h demonstrating that the exposure did not cause a significant mitochondrial proliferation, while it induced a significant increase in the respiratory activity and mitochondrial polarization. In addition, we found that hsp60 was up-regulated while hsp70 and COXII and COXIV were down-regulated. The mRNA for hsp70 remained constant and only the inducible form of the 70-kDa heat shock protein was over expressed. The mRNAs for COXII and COXIV remained constant after 24 h and increased after lo…