Search results for "RECEPTORS"

Intratumoral Heterogeneity for hsp90β mRNA Levels in a Breast Cancer Cell Line

1997

BC-3A and BC-61 are two breast cancer cell lines that have been cloned from parental 8701-BC cells and exhibit different biosynthetic, proliferative, and invasive properties in vitro. In the attempt to search whether alterations in the profiles of gene expression could be detected, we have submitted both cytotypes to identification of differentially expressed cDNAs. In addition, steroid hormone receptor mRNA arrays and in vivo tumorigenesis of the two lines have been checked. The technique used allowed identification of changes in the expression of the 90-kD heat shock protein-beta (hsp90beta) which is prominently down-regulated in BC-61 cells. Because we have also found that these cells, w…

Effects of Hypericum Extract on the Expression of Serotonin Receptors

1994

The influence of hypericum extract LI 160 on the expression of serotonin receptors was investigated using a neuroblastoma cell line to establish a model for the regulation of neurotransmitters by immunologically active compounds such as cytokines. The cells were incubated with hypericum extract LI 160 in kinetic form for 2, 4, 6, 8, and 10 hours, then washed. The serotonin receptor expression analysis was compared to that of a placebo control solution. The neuroblastoma cells showed a clearly reduced expression of the serotonin receptors under treatment with hypericum extract. First stimulation experiments with interleukin-1 (IL-1) and hypericum extract suggest that a further reduction of …

Bond-based 3D-chiral linear indices: Theory and QSAR applications to central chirality codification

2008

The recently introduced non-stochastic and stochastic bond-based linear indices are been generalized to codify chemical structure information for chiral drugs, making use of a trigonometric 3D-chirality correction factor. These improved modified descriptors are applied to several well-known data sets to validate each one of them. Particularly, Cramer's steroid data set has become a benchmark for the assessment of novel quantitative structure activity relationship methods. This data set has been used by several researchers using 3D-QSAR approaches such as Comparative Molecular Field Analysis, Molecular Quantum Similarity Measures, Comparative Molecular Moment Analysis, E-state, Mapping Prope…

Expression of a glucocorticoid receptor (D1GR1) in several tissues of the teleost fish Dicentrarchus labrax

2008

Since glucocorticoids have a role in maintaining the homeostatic status in fish, in the present paper mRNA expression (in situ hybridization) and tissue immunohistochemical localization of a glucocorticoid receptor (DlGR1) in several Dicentrarchus labrax organs are reported. Riboprobe and specific antibodies were prepared by using the DlGR1 that has been previously cloned and sequenced from peritoneal cavity leukocytes. Both mRNA and receptor were identified in head kidney, spleen, gills, intestine, heart and liver tissues. The functional roles of DlGR1 localization are discussed.

Molecular mechanisms determining the strength of receptor-mediated intermembrane adhesion

1995

The strength of receptor-mediated cell adhesion is directly controlled by the mechanism of cohesive failure between the cell surface and underlying substrate. Unbinding can occur either at the locus of the specific bond or within the bilayer, which results in tearing the hydrophobic anchors from the membrane interior. In this work, the surface force apparatus has been used to investigate the relationship between the receptor-ligand bond affinities and the dominant mechanism of receptor-coupled membrane detachment. The receptors and ligands used in this study were membrane-bound streptavidin and biotin analogs, respectively, with solution affinities ranging over 10 orders of magnitude. With …

Stimulant-induced adaptations in neostriatal matrix and striosome systems: Transiting from instrumental responding to habitual behavior in drug addic…

2005

Abstract Converging evidence indicates that repeated exposure to motor stimulants such as cocaine and amphetamine produces marked alterations in network responsiveness of striatal neurons to subsequent challenge with the same stimulant drug. Such alterations, which correlate with persistent patterns of repetitive behavior, associate with distinct compartmental changes in the neostriatum. Striatal matrix system neurons undergo “silencing” following repeated drug challenges, allowing striosome system neurons to exhibit preferential activation. Matrix neurons are innervated by sensory and motor areas of neocortex and are activated in the course of on-going, adaptive behavior. Inactivation of m…

Efficient differentiation of embryonic stem cells into mesodermal precursors by BMP, retinoic acid and Notch signalling

2012

The ability to direct differentiation of mouse embryonic stem (ES) cells into specific lineages not only provides new insights into the pathways that regulate lineage selection but also has translational applications, for example in drug discovery. We set out to develop a method of differentiating ES cells into mesodermal cells at high efficiency without first having to induce embryoid body formation. ES cells were plated on a feeder layer of PA6 cells, which have membrane-associated stromal-derived inducing activity (SDIA), the molecular basis of which is currently unknown. Stimulation of ES/PA6 co-cultures with Bone Morphogenetic Protein 4 (BMP4) both favoured self-renewal of ES cells and…

Inhibition of B2 receptor internalization delays its dephosphorylation

1997

Sympathetic neurons can produce and respond to interleukin 6

1998

Neuronal expression of cytokines is an area of active investigation in the contexts of development, disease, and normal neural function. Although cultured rat sympathetic neurons respond very weakly to exogenous interleukin 6 (IL-6), we find that addition of soluble IL-6 receptor (sIL-6R) and IL-6 enhances neuronal survival in the absence of nerve growth factor. Neutralizing monoclonal antibodies against IL-6 block these effects. Addition of IL-6 and sIL-6R also induces a subset of neuropeptide and transmitter synthetic enzyme mRNAs identical to that demonstrated for leukemia inhibitory factor, ciliary neurotrophic factor, and oncostatin M. Both of these effects are duplicated by addition o…

Determinants essential for the transmissible gastroenteritis virus-receptor interaction reside within a domain of aminopeptidase-N that is distinct f…

1994

The swine-specific coronavirus transmissible gastroenteritis virus (TGEV) uses pig aminopeptidase-N (pAPN) as a cellular receptor. We showed that the human aminopeptidase-N (hAPN) cannot substitute for pAPN in this respect, although the two enzymes have 80% amino acid sequence identity. In order to map the TGEV binding site on pAPN, we constructed a series of APN cDNA chimeras between pAPN and hAPN and analyzed them for their capacity to confer infectivity. The region between residues 717 and 813 was found to be essential for infectivity. This region also contains the epitopes for three TGEV-blocking monoclonal antibodies directed against pAPN. These data support the view that the catalytic…