Stellar motions in galactic satellites

The study of the motions of the stars that belong to a galactic satellite (i.e. a globular cluster or a dwarf galaxy orbiting a larger one) has some similarities, as well as significant differences, with that of the restricted three-body problem of celestial mechanics. The high percentage of chaotic orbits present in some models is of particular interest because it rises, on the one hand, the question of the origin of those chaotic motions and, on the other hand, the question of whether an equilibrium stellar system can be built when the bulk of the stars that make it up behave chaotically.Fil: Muzzio, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica la Plata; Argentina. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Vergne, Maria Marcela. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica la Plata; ArgentinaFil: Wachlin, Felipe Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica la Plata; Argentina. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Carpintero, Daniel Diego. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica la Plata; Argentin

IFNβ and glatiramer acetate trigger different signaling pathways to regulate the IL-1 system in multiple sclerosis

Imbalance in cytokine homeostasis plays an important part in the pathogenesis of various chronic inflammatory diseases. In multiple sclerosis (MS), the pro-inflammatory cytokine interleukin-1β (IL-1β) is present in the central nervous system, being expressed mainly in infiltrating macrophages and microglial cells. IL-1β activity is inhibited by the secreted form of IL-1 receptor antagonist (sIL-1Ra) whose production is increased in patients' blood and induced in human monocytes by IFNβ and glatiramer acetate (GA)—both immunomodulators displaying similar therapeutic efficacy in MS. Because intracellular pathways are currently considered as potential therapeutic targets, identification of specific kinases used by both immunomodulators might lead to more specific therapeutic targeting. We addressed the question of intracellular pathways used by IFNβ and GA to induce sIL-1Ra in human monocytes in two recent studies. This addendum to these studies aims at discussing common pathways and different elements used by IFNβ and GA to induce sIL-1Ra in human monocytes. This pinpoints PI3Kδ activation as a requirement to induce sIL-1Ra production downstream monocyte stimulation by either IFNβ or GA. However, the immunomodulators differentially use MEK/ERK pathway to induce sIL-1Ra production in human monocytes. Together, our current studies suggest that PI3Kδ and MEK2 might represent new targets in MS therapy