Search results for "Cell Surface"

dsRNA-functionalized multifunctional gamma-Fe2O3 nanocrystals: a tool for targeting cell surface receptors.

2008

Plexin-B1 and Semaphorin 4D Cooperate to Promote Perineural Invasion in a RhoA/ROK-Dependent Manner

2012

Perineural invasion (PNI) is a tropism of tumor cells for nerve bundles located in the surrounding stroma. It is a pathological feature observed in certain tumors, referred to as neurotropic malignancies, that severely limits the ability to establish local control of disease and results in pain, recurrent growth, and distant metastases. Despite the importance of PNI as a prognostic indicator, its biological mechanisms are poorly understood. The semaphorins and their receptors, the plexins, compose a family of proteins originally shown to be important in nerve cell adhesion, axon migration, and proper central nervous system development. Emerging evidence has demonstrated that these factors a…

In human and rat lung membranes [35s]GTPγS binding is a tool for pharmacological characterization of G protein-coupled devucleotide receptors

1999

The P2Y receptor family is activated by extracellular nucleotides such as ATP and UTP. P2Y receptors regulate physiological functions in numerous cell types. In lung, the P2Y2 receptor subtype plays a role in controlling Cl- and fluid transport. Besides ATP or UTP, also diadenosine tetraphosphate (Ap4A), a stable nucleotide, seems to be of physiological importance. In membrane preparations from human and rat lung we applied several diadenosine polyphosphates to investigate whether they act as agonists for G protein-coupled receptors. We assessed this by determining the stimulation of [35S]GTPgammaS binding. Stimulation of [35S]GTPgammaS binding to G proteins has already been successfully ap…

Htid-1, the human homolog of the Drosophila melanogaster l(2)tid tumor suppressor, defines a novel physiological role of APC.

2007

Htid-1, the human counterpart of the Drosophila tumor suppressor gene lethal(2)tumorous imaginal discs (l(2)tid) encodes three splice forms translated into three cytosolic - Tid50, Tid48 and Tid46 - and three mitochondrial - Tid43, Tid40 and Tid38 - proteins. Here we provide evidence for the association of the endogenous Tid50/Tid48 proteins with the adenomatous polyposis coli (APC) tumor suppressor in normal colon epithelium, colorectal cancer cells and mouse NIH3T3 fibroblasts. Using the Glutathione S-transferase binding assay we show that the N-terminal region including the Armadillo domain (ARM) of APC is sufficient to bind the Tid molecules. Using immunoprecipitation and confocal micro…

Modulation of Hedgehog target gene expression by the Fused serine-threonine kinase in wing imaginal discs

1998

0925-4773 doi: DOI: 10.1016/S0925-4773(98)00130-0; The Fused (Fu) serine–threonine kinase and the Suppressor of fused (Su(fu)) product are part of the Hedgehog (Hh) signalling pathway both in embryos and in imaginal discs. In wing imaginal discs, the Hh signal induces Cubitus interruptus (Ci) accumulation and activates patched (ptc) and decapentaplegic (dpp) expression along the anterior/posterior (A/P) boundary. In this paper, we have examined the role of the Fu and Su(fu) proteins in the regulation of Hh target gene expression in wing imaginal discs, by using different classes of fu alleles and an amorphic Su(fu) mutation. We show that, at the A/P boundary, Fu kinase activity is involved …

Time-point and dosage of gene inactivation determine the tumor spectrum in conditional Ptch knockouts

2009

Mutations in Patched (PTCH) have been associated with tumors characteristic both for children [medulloblastoma (MB) and rhabdomyosarcoma (RMS)] and for elderly [basal cell carcinoma (BCC)]. The determinants of the variability in tumor onset and histology are unknown. We investigated the effects of the time-point and dosage of Ptch inactivation on tumor spectrum using conditional Ptch-knockout mice. Ptch heterozygosity induced prenatally resulted in the formation of RMS, which was accompanied by the silencing of the remaining wild-type Ptch allele. In contrast, RMS was observed neither after mono- nor biallelic postnatal deletion of Ptch. Postnatal biallelic deletion of Ptch led to BCC preca…

Autosomal recessive polycystic kidney disease: case report of a newborn with rare PKHD1 mutation, rapid renal enlargement and early fatal outcome

2020

Abstract Introduction Autosomal recessive polycystic kidney disease (ARPKD; MIM#263200) is one of the most frequent pediatric renal cystic diseases, with an incidence of 1:20,000. It is caused by mutations of the PKHD1 gene, on chromosome 6p12. The clinical spectrum is highly variable, ranging from late-onset milder forms to severe perinatal manifestations. The management of newborns with severe pulmonary insufficiency is challenging, and causes of early death are sepsis or respiratory failure. In cases of massive renal enlargement, early bilateral nephrectomy and peritoneal dialysis may reduce infant mortality. However, there is no conclusive data on the role of surgery, and decision-makin…

In vivo phage display: identification of organ-specific peptides using deep sequencing and differential profiling across tissues.

2021

Abstract In vivo phage display is widely used for identification of organ- or disease-specific homing peptides. However, the current in vivo phage biopanning approaches fail to assess biodistribution of specific peptide phages across tissues during the screen, thus necessitating laborious and time-consuming post-screening validation studies on individual peptide phages. Here, we adopted bioinformatics tools used for RNA sequencing for analysis of high-throughput sequencing (HTS) data to estimate the representation of individual peptides during biopanning in vivo. The data from in vivo phage screen were analyzed using differential binding—relative representation of each peptide in the target…

Muscarinic acetylcholine receptor trafficking in streptolysin O-permeabilized MDCK cells.

1996

We investigated the validity of streptolysin O (SLO)-permeabilized Madin-Darbin canine kidney (MDCK) cells which express muscarinic acetylcholine receptors (mAChRs) coupled to pertussis toxin-sensitive guanine nucleotide-binding proteins (G proteins) for the study of the molecular machinery that regulated mAChR internalization and recycling. Exposure of SLO-permeabilized cells to carbachol-reduced cell surface receptor number by up to 40% without changing total receptor number. The kinetics and maximal extent of receptor internalization as well as the potency of carbachol to induce receptor internalization were almost identical in SLO-permeabilized and non-permeabilized cells. Using this se…

Rho-mediated activation of PI(4)P5K and lipid second messengers is necessary for promotion of angiogenesis by Semaphorin 4D

2011

Phosphatidylinositol 4-phosphate 5-kinase (PI(4)P5K) is a type I lipid kinase that generates the lipid second messenger phospholipid phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) and functions downstream of RhoA in actin organization. It is known to play an essential role in neurite remodeling, yielding a phenotype identical to that seen in cells treated with Semaphorin 4D (Sema4D), a protein that regulates proliferation, adhesion and migration in many different cell types. Plexin-B1, the receptor for Sema4D, activates RhoA in order to generate a pro-angiogenic signal in endothelial cells. Therefore, we looked in human umbilical vein endothelial cells (HUVEC) to determine if Plexin-B1 e…