Search results for " ALPHA"
showing 10 items of 1610 documents
PAR1 signaling regulates the retention and recruitment of EPCR-expressing bone marrow hematopoietic stem cells
2015
Retention of long-term repopulating hematopoietic stem cells (LT-HSCs) in the bone marrow is essential for hematopoiesis and for protection from myelotoxic injury. We report that signaling cascades that are traditionally viewed as coagulation related also control retention of endothelial protein C receptor-positive (EPCR(+)) LT-HSCs in the bone marrow and their recruitment to the blood via two pathways mediated by protease activated receptor 1 (PAR1). Thrombin-PAR1 signaling induces nitric oxide (NO) production, leading to EPCR shedding mediated by tumor necrosis factor-α-converting enzyme (TACE), enhanced CXCL12-CXCR4-induced motility and rapid stem and progenitor cell mobilization. Conver…
Adhesion of 8701-BC breast cancer cells to type V collagen and 67 kDa receptor
1992
Ductal infiltration carcinomas (d.i.c.) of the breast are potentially highly metastatic tumours, associated with drastic alterations of the architecture and molecular composition of the extracellular matrix at the tumour-host interface. 8701-BC, a recently characterized cell line, isolated from primary d.i.c., was used to study different aspects of tumor cell-substratum interactions. Since type V collagen deposition is augmented in d.i.c. we have examined the ability of 8701-BC cells to interact with this collagen species. We have found that cell binding to type V collagen was mediated by protein homologous to the 67 kDa laminin receptor (67-R). This conclusion is substantiated by the follo…
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…
Intercellular communication and human hepatocellular carcinoma.
2005
We have previously reported that gap junction-mediated intercellular communication (GJIC) can be restored in junctionally deficient human prostate epithelial cells, also suggesting that GJIC activity is regulated by estrogen. In the present work, we report studies on sex steroid regulation of GJIC and proliferative activity in both nontumoral (Chang liver, CL) and malignant (HepG2, Huh7) human liver cells. Junctional activity and liver cell growth were measured using the scrape-loading/dye-transfer (SL/DT) and the MTS assay, respectively. Using the SL/DT, only Huh7 cells exhibited a moderate degree of Junctional activity in basic conditions, while neither CL nor HepG2 cells showed functiona…
Species-specific mechanisms for cholesterol 7alpha-hydroxylase (CYP7A1) regulation by drugs and bile acids.
2005
The gene encoding cholesterol 7alpha-hydroxylase (CYP7A1) is tightly regulated in order to control intrahepatic cholesterol and bile acid levels. Ligands of the xenobiotic-sensing pregnane X receptor inhibit CYP7A1 expression. To retrace the evolution of the molecular mechanisms underlying CYP7A1 inhibition, we used a chicken hepatoma cell system that retains the ability to be induced by phenobarbital and other drugs. Whereas bile acids regulate CYP7A1 via small heterodimer partner and liver receptor homolog-1, mRNA expression of these nuclear receptors is unchanged by xenobiotics. Instead, drugs repress chicken hepatic nuclear factor 4alpha (HNF4alpha) transcript levels concomitant with a …
Soluble interleukin-6 receptor (sIL-6R) makes IL-6R negative T cell line respond to IL-6: it inhibits TNF production
2000
The receptor for interleukin-6 (IL-6) consists of two subunits: a ligand specific IL-6Ralpha and gp130 that is responsible for signal-transduction. A soluble form of the ligand specific chain was described that when complexed to IL-6 is capable of binding to the membrane-bound gp130 subunit and thus can elicit signal-transduction. This soluble receptor can act on cells that express only the gp130 but not the ligand-specific subunit of the IL-6R. This phenomenon, called trans-signaling, introduced a novel aspect of cytokine action. In this study we examined the response of Jurkat cells, that are known not to express IL-6Ralpha, to IL-6, the soluble IL-6 receptor (sIL-6R) and a covalent compl…
Functional regulation of HIF-1α under normoxia--is there more than post-translational regulation?
2011
The hypoxia-inducible factor-1 (HIF-1) is an oxygen-regulated transcriptional activator playing a pivotal role in mammalian physiology and disease pathogenesis, e.g., HIF-1 is indispensable in a broad range of developmental stages in different tumors. Its post-translational regulation via PHDs under the influence of hypoxia is widely investigated and accepted. Different non-hypoxic stimuli such as lipopolysaccharides (LPS), thrombin, and angiotensin II (Ang II), have been proven to enhance HIF-1 levels through activation of regulative mechanisms distinct from protein stabilization. Some of these stimuli specifically regulate HIF-1α at the transcriptional, post-transcriptional, or translatio…
Large scale preparation of human MHC class II+ integrin beta(1)+ Tregs.
2010
Abstract The human CD4 + CD25 + FoxP3 + regulatory T cell population (Tregs) contains both MHC class II + and MHC class II − cells. MHC class II + Tregs belong to the integrin α 4 β 1 + subpopulation and exclusively execute contact-dependent suppressive activity. Here we present a method optimized for isolation of these MHC class II expressing Tregs from large leukaphereses products using magnetic microbeads that achieves a reproducible purity of more than 90% and enables the use of this small-sized Treg population in pre-clinical application and basic research.
Revista electrónica de investigación y evaluación educativa
2016
Este estudio evalúa un procedimiento nuevo para el análisis “micro-sociométrico” de los patrones relacionales de género en el alumnado adolescente, lo que se analiza aplicando Análisis de Correspondencias Múltiples (ACM). El propósito del estudio es desarrollar y validar la Escala de Preferencias Relacionales de Género (EPRG), con el fin de obtener datos válidos y fiables que permitan reconocer la predisposición de las chicas y los chicos adolescentes a relacionarse con sus iguales; y, si las relaciones que establecen están condicionadas por la socialización diferencial de género que propone el patriarcado (Bosch, Ferrer & Alzamora, 2006; Lagarde, 1996; Lomas, 2007; Lorente, 2007; Rodríguez…
Activation of Mast Cells by Streptolysin O and Lipopolysaccharide
2005
This chapter provides protocols to measure the reversible permeabilization of mast cells by streptolysin O (SLO) and to follow SLO-induced activation of mast cells by monitoring degranulation, activation of mitogen-activated protein kinases, and production of tumor necrosis factor-alpha. A method that uses SLO to deliver molecules into the cytosol of living cells also is described. Furthermore, we outline a procedure to measure the activation of nuclear factor-kappaB by lipopolysaccharide and ionomycin using transfection of mast cells with reporter genes by electroporation. These protocols should be widely applicable in mast cell research.