Search results for "Cellular Biology"
showing 10 items of 157 documents
Holo-APP and G-protein-mediated signaling are required for sAPPa-induced activation of the Akt survival pathway
2014
International audience; Accumulating evidence indicates that loss of physiologic amyloid precursor protein (APP) function leads to reduced neuronal plasticity, diminished synaptic signaling and enhanced susceptibility of neurons to cellular stress during brain aging. Here we investigated the neuroprotective function of the soluble APP ectodomain sAPPa (soluble APPa), which is generated by cleavage of APP by a-secretase along the non-amyloidogenic pathway. Recombinant sAPPa protected primary hippocampal neurons and SH-SY5Y neuroblastoma cells from cell death induced by trophic factor deprivation. We show that this protective effect is abrogated in neurons from APP-knockout animals and APP-de…
Dual regulation of SPI1/PU.1 transcription factor by heat shock factor 1 (HSF1) during macrophage differentiation of monocytes
2014
International audience; : In addition to their cytoprotective role in stressful conditions, heat shock proteins (HSPs) are involved in specific differentiation pathways, e.g. we have identified a role for HSP90 in macrophage differentiation of human peripheral blood monocytes exposed to Macrophage Colony-Stimulating Factor (M-CSF). Here, we show that deletion of the main transcription factor involved in heat shock gene regulation, heat shock factor 1 (HSF1), affects M-CSF-driven differentiation of mouse bone marrow cells. HSF1 transiently accumulates in the nucleus of human monocytes undergoing macrophage differentiation, including M-CSF-treated peripheral blood monocytes and phorbol ester-…
XPO1E571K Mutation Modifies Exportin 1 Localisation and Interactome in B-cell Lymphoma
2020
The XPO1 gene encodes exportin 1 (XPO1) that controls the nuclear export of cargo proteins and RNAs. Almost 25% of primary mediastinal B-cell lymphoma (PMBL) and classical Hodgkin lymphoma (cHL) cases harboured a recurrent XPO1 point mutation (NM_003400, chr2:g61718472C>
Breast cancer cell lines contain functional cancer stem cells with metastatic capacity and a distinct molecular signature.
2009
Abstract Tumors may be initiated and maintained by a cellular subcomponent that displays stem cell properties. We have used the expression of aldehyde dehydrogenase as assessed by the ALDEFLUOR assay to isolate and characterize cancer stem cell (CSC) populations in 33 cell lines derived from normal and malignant mammary tissue. Twenty-three of the 33 cell lines contained an ALDEFLUOR-positive population that displayed stem cell properties in vitro and in NOD/SCID xenografts. Gene expression profiling identified a 413-gene CSC profile that included genes known to play a role in stem cell function, as well as genes such as CXCR1/IL-8RA not previously known to play such a role. Recombinant int…
Aldehyde Dehydrogenase 1-Positive Cancer Stem Cells Mediate Metastasis and Poor Clinical Outcome in Inflammatory Breast Cancer
2009
Abstract Purpose: To examine the role of cancer stem cells (CSC) in mediating metastasis in inflammatory breast cancer (IBC) and the association of these cells with patient outcome in this aggressive type of breast cancer. Experimental Design: CSCs were isolated from SUM149 and MARY-X, an IBC cell line and primary xenograft, by virtue of increased aldehyde dehydrogenase (ALDH) activity as assessed by the ALDEFLUOR assay. Invasion and metastasis of CSC populations were assessed by in vitro and mouse xenograft assays. Expression of ALDH1 was determined on a retrospective series of 109 IBC patients and this was correlated with histoclinical data. All statistical tests were two sided. Log-rank …
Spontaneous and Fas-induced apoptosis of low-grade MDS erythroid precursors involves the endoplasmic reticulum
2008
Spontaneous apoptosis of bone marrow erythroid precursors accounts for the anemia that characterizes most low-grade myelodysplastic syndromes (MDS). We have shown that death of these precursors involved the Fas-dependent activation of caspase-8. To explore the pathway leading from caspase-8 activation to apoptosis, we transduced MDS bone marrow CD34(+) cells with a lentivirus encoding wild-type (WT) or endoplasmic reticulum (ER)-targeted Bcl-2 protein before inducing their erythroid differentiation. Both WT-Bcl-2 and ER-targeted Bcl-2 prevented spontaneous and Fas-dependent apoptosis in MDS erythroid precursors. ER-targeted Bcl-2 inhibited mitochondrial membrane depolarization and cytochrom…
Highly Fluorescent and Water-Soluble Diketopyrrolopyrrole Dyes for Bioconjugation
2015
International audience; The preparation of highly water-soluble and strongly fluorescent diketopyrrolopyrrole (DPP) dyes using an unusual taurine-like sulfonated linker has been achieved. Exchanging a phenyl for a thienyl substituent shifts the emission wavelength to near λ=600 nm. The free carboxylic acid group present in these new derivatives was readily activated and the dyes were subsequently covalently linked to a model protein (bovine serum albumin; BSA). The bioconjugates were characterized by electronic absorption, fluorescence spectroscopy and MALDI-TOF mass spectrometry, thus enabling precise determination of the labeling density (ratio DPP/BSA about 3 to 8). Outstanding values of…
Type-2 histones deacetylases and cryptogein-induced cell death in tabacco
2011
Cryptogein, which is secreted by the oomycete Phytophthora cryptogea, is a proteinaceous elicitor of plant defense reactions that activates a set of signaling events leading to the hypersensitive response and to systemic acquired resistance. Although the early cytosolic signaling events induced by cryptogein are well described, the only nuclear events characterized to date are the variations in free calcium concentrations and defense-related gene expression. The characterization of the activation of cytosolic protein kinases, including WIPK and SIPK, by phosphorylation in response to cryptogein highlights the key-role played by posttranslational modifications in cryptogein-induced signaling…
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 …
Chemical and behavioural characterization of the rabbit mammary pheromone.
2003
Mammals owe part of their evolutionary success to the harmonious exchanges of information, energy and immunity between females and their offspring. This functional reciprocity is vital for the survival and normal development of infants, and for the inclusive fitness of parents. It is best seen in the intense exchanges taking place around the mother's offering of, and the infant's quest for, milk. All mammalian females have evolved behavioural and sensory methods of stimulating and guiding their inexperienced newborns to their mammae, whereas newborns have coevolved means to respond to them efficiently. Among these cues, maternal odours have repeatedly been shown to be involved, but the chem…