Role of TI-VAMP and CD82 in EGFR cell-surface dynamics and signaling.

The v-SNARE TI-VAMP (VAMP7) mediates exocytosis during neuritogenesis, phagocytosis and lysosomal secretion. It localizes to endosomes and lysosomes but also to the trans-Golgi network. Here we show that depletion of TI-VAMP enhances the endocytosis of activated EGF receptor (EGFR) without affecting constitutive endocytosis of EGFR, or transferrin uptake.

Mitochondrial inside-out signalling during alkylating agent-induced anoikis.

Exposure of epithelial respiratory cells to the alkylating agent, mechlorethamine (HN2), induces anoikis initiated by mitochondrial depolarization and caspase-2 activation. The mechanisms of disruption of cell interactions were investigated and expression of integrins, E-cadherin, and actin were therefore studied after HN2 treatment. In the adherent cells, an early disruption of F-actin occurred associated with cell rounding.

The LIM-only protein FHL2 regulates cyclin D1 expression and cell proliferation.

The LIM-only protein FHL2 acts as a transcriptional modulator that positively or negatively regulates multiple signaling pathways. We recently reported that FHL2 cooperates with CREB-binding protein/p300 in the activation of beta-catenin/T cell factor target gene cyclin D1. In this paper, we demonstrate that FHL2 is associated with the cyclin D1 promoter at the T cell factor/CRE site, providing evidence that cyclin D1 is a direct target of FHL2.

Tolerance induction to self-MHC antigens in fetal and neonatal mouse B cells.

We have studied the mechanisms of tolerance induction to self-MHC antigens in mouse B cells during fetal development and the post-natal period. To monitor the fate of autoreactive B cell clones, we used the 3-83 micro delta B cell receptor (BCR)-transgenic (Tg) and -knock-in (KI) mouse models. These BCR-Tg and -KI B cells recognize the MHC class I molecules H-2K(k) and H-2K(b), with a high or moderate affinity, respectively.

Flow cytometry to sort mammalian cells in cytokinesis.

Background: Cell division or cytokinesis, which results from a series of events starting in metaphase, is the mechanism by which the mother cell cytoplasm is divided between the two daughter cells. Hence it is the final step of the cell division cycle. The aim of the present study was to demonstrate that mammalian cells undergoing cytokinesis can be sorted selectively by flow cytometry.

Responses of well-differentiated nasal epithelial cells exposed to particles: role of the epithelium in airway inflammation.

Numerous epidemiological studies support the contention that ambient air pollution particles can adversely affect human health. To explain the acute inflammatory process in airways exposed to particles, a number of in vitro studies have been performed on cells grown submerged on plastic and poorly differentiated, and on cell lines, the physiology of which is somewhat different from that of well-differentiated cells. In order to obtain results using a model system in which epithelial cells are similar to those of the human airway in vivo, apical membranes of well-differentiated human nasal epithelial (HNE) cells cultured in an air-liquid interface (ALI) were exposed for 24 h to diesel exhaust particles (DEP) and Paris urban air particles (PM(2.

Distinct domains of the spinal muscular atrophy protein SMN are required for targeting to Cajal bodies in mammalian cells.

Mutations of the survival motor neuron gene SMN1 cause the inherited disease spinal muscular atrophy (SMA). The ubiquitous SMN protein facilitates the biogenesis of spliceosomal small nuclear ribonucleoproteins (snRNPs). The protein is detected in the cytoplasm, nucleoplasm and enriched with snRNPs in nuclear Cajal bodies.

Pregnancy-induced alterations of B cell maturation and survival are differentially affected by Fas and Bcl-2, independently of BcR expression.

In the present work, we have analyzed the roles of two molecules involved in the regulation of cell survival, Bcl2 and Fas, in the pregnancy-induced down-regulation of B lymphopoiesis in mice. Our results show that the overexpression of the anti-apoptotic molecule Bcl2 in Bcl2-transgenic (Tg) B cells is able to protect 'D' fraction pre-B cells from pregnancy-induced deletion. In contrast, in Fas(lpr/lpr) mice bearing a mutated cell death receptor Fas, such B cell targets are not protected.

Affinity-dependent alterations of mouse B cell development by noninherited maternal antigen.

We have examined the passage of maternal cells into the fetus during the gestation and postpartum in mice. Using enhanced green fluorescent protein (EGFP)-transgenic females, we showed that maternal cells frequently gain access to the fetus, mostly in syngeneic pregnancies, but also in allogeneic and outbred crosses. EGFP-transgenic cells, including B, T, and natural killer cells, can persist until adulthood, primarily in bone marrow and thymus.

Replication of the chicken beta-globin locus: early-firing origins at the 5' HS4 insulator and the rho- and betaA-globin genes show opposite epigenetic modifications.

Chromatin structure is believed to exert a strong effect on replication origin function. We have studied the replication of the chicken beta-globin locus, whose chromatin structure has been extensively characterized. This locus is delimited by hypersensitive sites (HSs) that mark the position of insulator elements.

HLA-DR and ICAM-1 expression and modulation in epithelial cells from nasal polyps.

Objective/hypothesis: Through human leukocyte antigen-DR (HLA-DR) and intercellular adhesion molecule-1 (ICAM-1) expression, nasal epithelial cells could actively participate in the chronic inflammation and eosinophil infiltration observed in nasal polyps. The objective of the study was to evaluate HLA-DR and ICAM-1 expression in polyp epithelium and in a culture model of polyp epithelial cells allowing ciliated and secretory differentiation.

Study Design: Prospective non-randomized controlled in vitro study.