Lorenzo Silengo

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Phosphoinositide 3-kinase (PI3K) activity is crucial for leukocyte function, but the roles of the four receptor-activated isoforms are unclear. Mice lacking heterotrimeric guanine nucleotide-binding protein (G protein)-coupled PI3Kgamma were viable and had fully differentiated neutrophils and macrophages. Chemoattractant-stimulated PI3Kgamma-/- neutrophils(More)
Integrin-mediated cell adhesion cooperates with growth factor receptors in the control of cell proliferation, cell survival, and cell migration. One mechanism to explain these synergistic effects is the ability of integrins to induce phosphorylation of growth factor receptors, for instance the epidermal growth factor (EGF) receptor. Here we define some(More)
The G protein-coupled, receptor-activated phosphoinositide 3-kinase gamma (PI3Kgamma) mediates inflammatory responses and negatively controls cardiac contractility by reducing cAMP concentration. Here, we report that mice carrying a targeted mutation in the PI3Kgamma gene causing loss of kinase activity (PI3KgammaKD/KD) display reduced inflammatory(More)
Adhesion of human primary skin fibroblasts and ECV304 endothelial cells to immobilized matrix proteins, beta1 or alphav integrin antibodies stimulates tyrosine phosphorylation of the epidermal growth factor (EGF) receptor. This tyrosine phosphorylation is transiently induced, reaching maximal levels 30 min after adhesion, and it occurs in the absence of(More)
The phosphoinositide 3-kinase (PI3K) pathway crucially controls metabolism and cell growth. Although different PI3K catalytic subunits are known to play distinct roles, the specific in vivo function of p110beta (the product of the PIK3CB gene) is not clear. Here, we show that mouse mutants expressing a catalytically inactive PIK3CB(K805R) mutant survived to(More)
Rat pheochromocytoma PC12 cells exposed to nerve growth factor differentiate as sympathetic neurons and extend neurites on laminin and to a much lesser extent on fibronectin. Analysis of laminin fragments indicated that neurite outgrowth occurs mainly on fragment P1, corresponding to the center of the cross, and only poorly on fragment E8, a long arm(More)
Citron-kinase (Citron-K) has been proposed by in vitro studies as a crucial effector of Rho in regulation of cytokinesis. To further investigate in vivo its biologic functions, we have inactivated Citron-K gene in mice by homologous recombination. Citron-K-/- mice grow at slower rates, are severely ataxic, and die before adulthood as a consequence of fatal(More)
The Down syndrome critical region (DSCR) on Chromosome 21 contains many genes whose duplication may lead to the major phenotypic features of Down syndrome and especially the associated mental retardation. However, the functions of DSCR genes are mostly unknown and their possible involvement in key brain developmental events still largely unexplored. In this(More)
Using two-hybrid screening, we isolated the integrin cytoplasmic domain-associated protein (ICAP-1), an interactor for the COOH terminal region of the beta1A integrin cytoplasmic domain. To investigate the role of ICAP-1 in integrin-mediated adhesive function, we expressed the full-length molecule in NIH3T3 cells. ICAP-1 expression strongly prevents NIH3T3(More)
Protection against oxidative damage caused by excessive reactive oxygen species (ROS) by an antioxidant network is essential for the health of tissues, especially in the cardiovascular system. Here, we identified a gene with important antioxidant features by analyzing a null allele of zebrafish ubiad1, called barolo (bar). bar mutants show specific(More)