Ibtissam Youlyouz-Marfak

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Filaminopathies A caused by mutations in the X-linked FLNA gene are responsible for a wide spectrum of rare diseases including 2 main phenotypes, the X-linked dominant form of periventricular nodular heterotopia (FLNA-PVNH) and the otopalatodigital syndrome spectrum of disorders. In platelets, filamin A (FLNa) tethers the principal receptors ensuring the(More)
1-(2-Chlorophenyl-N-methylpropyl)-3-isoquinolinecarboxamide (PK11195) is a prototypic ligand of the peripheral benzodiazepine receptor (PBR), a mitochondrial outer membrane protein. PK11195 can be used to chemosensitize tumor cells to a variety of chemotherapeutic agents, both in vitro and in vivo. PK11195 has been suggested to exert this effect via(More)
Chemotherapeutic drugs such as fludarabine*, doxorubicin or cisplatin are very potent activators of the anti-oncogene p53. Convergent studies suggest that p53 and STAT1 (signal transducer and activator of transcription 1) cooperate in the induction of cell death. We show that these drugs are also activators of STAT1 in p53-expressing cells, but not in(More)
Epstein-Barr virus (EBV) induces CD95 expression and the CD95 gene (FAS) is regulated by NF-kappaB, STAT1, and/or p53. To understand the contribution of these factors in the regulation of CD95 by EBV in lymphoblastoid cell lines (LCLs), we cloned dominant-active IkappaBalpha, active (STAT1alpha) and inactive (STAT1beta) forms of STAT1, p53, a(More)
Constitutive activation of signal transducer and activator of transcription 1 (STAT1) is a distinctive feature of Epstein-Barr virus (EBV)-immortalized B cells (lymphoblastoid cell lines [LCLs]). The expression of STAT1 in these cells is modulated by the latent membrane protein 1 (LMP1), but the mechanism of STAT1 activation has remained unclear. We(More)
von Willebrand factor (VWF) is an essential mediator of platelet adhesion to the vessel wall, but little is known about its role in megakaryocytopoiesis. VWF and its platelet receptor, glycoprotein Ibalpha (GPIbalpha), are both expressed during megakaryocyte (MK) maturation. This study was designed to evaluate whether the enhanced VWF-GPIbalpha interactions(More)
Alternate splicing of STAT1 produces two isoforms: alpha, known as the active form, and beta, previously shown to act as a dominant-negative factor. Most studies have dealt with STAT1alpha, showing its involvement in cell growth control and cell death. To examine the specific function of either isoform in cell death, a naturally STAT1-deficient human B cell(More)
EBV-immortalized B cells induce a complex immune response such that the virus persists as a clinically silent infection for the lifetime of the infected host. B7-H1, also called PD-L1, is a cosignaling molecule of the B7 family that can inhibit activated T cell effectors by interaction with its receptor PD-1. In this work, we have studied the dependence of(More)
Flow cytometry is the reference technique for assessing ZAP70 expression, a marker of poor prognosis in CLL. One of the most common methods is to assess ZAP70 levels in CLL cells by calculating the ratio between ZAP70 mean fluorescence intensities (MFIs) in residual T-cells and CLL B-cells (ZAP70 T/B ratio). In this study, we developed a new method for(More)
In this study, we determined the respective roles of RelA and RelB NF-κB subunits in Epstein-Barr virus (EBV)-transformed B cells. Using different EBV-immortalized B-cell models, we showed that only RelA activation increased both survival and cell growth. RelB activity was induced secondarily to RelA activation and repressed RelA DNA binding by trapping the(More)