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1.
Environ Manage ; 67(5): 886-900, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33474617

RESUMEN

Our digital age is characterized by both a generalized access to data and an increased call for participation of the public and other stakeholders and communities in policy design and decision-making. This context raises new challenges for political decision-makers and analysts in providing these actors with new means and moral duties for decision support, including in the area of environmental policy. The concept of "policy analytics" was introduced in 2013 as an attempt to develop a framework, tools, and methods to address these challenges. This conceptual initiative prompted numerous research teams to develop empirical applications of this framework and to reflect on their own decision-support practice at the science-policy interface in various environmental domains around the world. During a workshop in Paris in 2018, participants shared and discussed their experiences of these applications and practices. In this paper, we present and analyze a set of applications to identify a series of key properties that underpin a policy analytics approach, in order to provide the conceptual foundation for policy analytics to address current policy design and decision-making challenges. The induced properties are demand-orientedness, performativity, normative transparency, and data meaningfulness. We show how these properties materialized through these six case studies, and we explain why we consider them key to effective policy analytics applications, particularly in environmental policy design and decision-making on environmental issues. This clarification of the policy analytics concept eventually enables us to highlight research frontiers to further improve the concept.


Asunto(s)
Conservación de los Recursos Naturales , Formulación de Políticas , Humanos , Políticas
2.
Platelets ; 27(5): 402-9, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26943229

RESUMEN

The physiological functions and cellular signaling of Class II phosphoinositide 3-kinases (PI3Ks) remain largely unknown. Platelets express two Class II PI3Ks: PI3KC2α and PI3KC2ß. PI3KC2α deficiency was recently reported to cause disruption of the internal membrane reserve structure of platelets (open canalicular system, OCS) that results in dysregulated platelet adhesion and impaired arterial thrombosis in vivo. Notably, these effects on platelets occurred despite normal agonist-induced 3-phosphorylated phosphoinositide (3-PPI) production and cellular activation in PI3KC2α-deficient platelets. However, the potential compensatory actions of PI3KC2ß in platelets have not yet been investigated. Here, we report the first mice deficient in both PI3KC2α and PI3KC2ß (no Class II PI3Ks in platelets) and reveal a nonredundant role for PI3KC2α in mouse platelet structure and function. Specifically, we show that the disrupted OCS and impaired thrombus stability observed in PI3KC2α-deficient platelets does not occur in PI3KC2ß-deficient platelets and is not exaggerated in platelets taken from mice deficient in both enzymes. Furthermore, detailed examination of 3-PPI production in platelets from this series of mice revealed no changes in either unactivated or activated platelets, including those with a complete lack of Class II PI3Ks. These findings indicate a nonredundant role for PI3KC2α in regulating platelet structure and function, and suggest that Class II PI3Ks do not significantly contribute to the acute agonist-induced production of 3-PPIs in these cells.


Asunto(s)
Plaquetas/metabolismo , Fosfatidilinositol 3-Quinasas Clase II/deficiencia , Trombosis/sangre , Trombosis/genética , Animales , Plaquetas/ultraestructura , Fosfatidilinositol 3-Quinasas Clase II/genética , Fosfatidilinositol 3-Quinasas Clase II/metabolismo , Fosfatidilinositol 3-Quinasas Clase III/genética , Fosfatidilinositol 3-Quinasas Clase III/metabolismo , Modelos Animales de Enfermedad , Regulación de la Expresión Génica , Ratones , Ratones Noqueados , Adhesividad Plaquetaria , Recuento de Plaquetas , Pruebas de Función Plaquetaria
3.
Am J Pathol ; 182(3): 875-85, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23313136

RESUMEN

Microglial cells are the resident macrophages of the central nervous system and participate in both innate and adaptive immune responses but can also lead to exacerbation of neurodegenerative pathologies after viral infections. Microglia in the outer layers of the retina and the subretinal space are thought to be involved in retinal diseases where low-grade chronic inflammation and oxidative stress play a role. This study investigated the effect of systemic infection with murine cytomegalovirus on the distribution and dynamics of retinal microglia cells. Systemic infection with murine cytomegalovirus elicited a significant increase in the number of microglia in the subretinal space and an accumulation of iris macrophages, along with morphological signs of activation. Interferon γ (IFN-γ)-deficient mice failed to induce changes in microglia distribution. Bone marrow chimera experiments confirmed that microglial cells in the subretinal space were not recruited from the circulating monocyte pool, but rather represented an accumulation of resident microglial cells from within the retina. Our results demonstrate that a systemic viral infection can lead to IFN-γ-mediated accumulation of microglia into the outer retinal layers and offer proof of concept that systemic viral infections alter the ocular microenvironment and therefore, may influence the course of diseases such as macular degeneration, diabetic retinopathy, or autoimmune uveitis, where low-grade inflammation is implicated.


Asunto(s)
Movimiento Celular , Infecciones por Citomegalovirus/patología , Interferón gamma/metabolismo , Microglía/patología , Muromegalovirus/fisiología , Retina/patología , Retina/virología , Animales , Proteínas de Unión al Calcio/metabolismo , Recuento de Células , Movimiento Celular/efectos de los fármacos , Infecciones por Citomegalovirus/virología , Femenino , Citometría de Flujo , Iris/patología , Iris/virología , Macrófagos/efectos de los fármacos , Macrófagos/patología , Macrófagos/virología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Proteínas de Microfilamentos/metabolismo , Microglía/efectos de los fármacos , Microglía/virología , Muromegalovirus/efectos de los fármacos , Factor 88 de Diferenciación Mieloide/metabolismo , Oligodesoxirribonucleótidos/administración & dosificación , Oligodesoxirribonucleótidos/farmacología , Retina/efectos de los fármacos , Segmento Externo de las Células Fotorreceptoras Retinianas/efectos de los fármacos , Segmento Externo de las Células Fotorreceptoras Retinianas/patología , Segmento Externo de las Células Fotorreceptoras Retinianas/virología
4.
Immunol Cell Biol ; 90(3): 330-6, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21577228

RESUMEN

Cytomegalovirus (CMV) reactivation in the retina of immunocompromized patients is a cause of significant morbidity as it can lead to blindness. The adaptive immune response is critical in controlling murine CMV (MCMV) infection in MCMV-susceptible mouse strains. CD8(+) T cells limit systemic viral replication in the acute phase of infection and are essential to contain latent virus. In this study, we provide the first evaluation of the kinetics of anti-viral T-cell responses after subretinal infection with MCMV. The acute response was characterized by a rapid expansion phase, with infiltration of CD8(+) T cells into the infected retina, followed by a contraction phase. MCMV-specific T cells displayed biphasic kinetics with a first peak at day 12 and contraction by day 18 followed by sustained recruitment of these cells into the retina at later time points post-infection. MCMV-specific CD8(+) T cells were also observed in the draining cervical lymph nodes and the spleen. Presentation of viral epitopes and activation of CD8(+) T cells was widespread and could be detected in the spleen and the draining lymph nodes, but not in the retina or iris. Moreover, after intraocular infection, antigen-specific cytotoxic activity was detectable and exhibited kinetics equivalent to those observed after intraperitoneal infection with the same viral dose. These data provide novel insights of how and where immune responses are initiated when viral antigen is present in the subretinal space.


Asunto(s)
Inmunidad Adaptativa , Linfocitos T CD8-positivos/inmunología , Retinitis por Citomegalovirus/inmunología , Citomegalovirus/inmunología , Retina/inmunología , Animales , Presentación de Antígeno , Linfocitos T CD8-positivos/virología , Procesos de Crecimiento Celular , Movimiento Celular , Células Cultivadas , Retinitis por Citomegalovirus/virología , Modelos Animales de Enfermedad , Epítopos de Linfocito T/inmunología , Epítopos de Linfocito T/metabolismo , Humanos , Activación de Linfocitos , Ratones , Ratones Endogámicos BALB C , Ratones Transgénicos , Retina/virología , Proteínas Virales/inmunología , Proteínas Virales/metabolismo
5.
Haematologica ; 94(6): 800-10, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19377075

RESUMEN

BACKGROUND: Giant platelets and thrombocytopenia are invariable defects in the Bernard-Soulier syndrome caused by deficiency of the GPIb-V-IX complex, a receptor for von Willebrand factor supporting platelet adhesion to the damaged arterial wall. Various properties of this receptor may be considered potential determinants of the macrothrombocytopenia. DESIGN AND METHODS: To explore the underlying mechanisms of the disease, megakaryopoiesis was studied in a mouse model deficient in GPIbbeta. Megakaryocytes were initially characterized in situ in the bone marrow of adult mice, after which their capacity to differentiate into proplatelet-bearing cells was evaluated in cultured fetal liver cells. RESULTS: The number of megakaryocyte progenitors, their differentiation and progressive maturation into distinct classes and their level of endoreplication were normal in GPIbbeta(-/-) bone marrow. However, the more mature cells exhibited ultrastructural anomalies with a thicker peripheral zone and a less well developed demarcation membrane system. GPIbbeta(-/-) megakaryocytes could be differentiated in culture from Lin(-) fetal liver cells in normal amounts but the proportion of cells able to extend proplatelets was decreased by 41%. Moreover, the GPIbbeta(-/-) cells extending proplatelets displayed an abnormal morphology characterized by fewer pseudopodial extensions with thicker shaft sections and an increased diameter of the terminal coiled elements. GPIbbeta(-/-) released platelets were larger but retained a typical discoid shape. Proplatelet formation was similarly affected in bone marrow explants from adult mice examined by videomicroscopy. The marginal microtubular ring contained twice as many tubulin fibers in GPIbbeta(-/-) proplatelet buds in cultured and circulating platelets. CONCLUSIONS: Altogether, these findings point to a role of the GPIb-V-IX complex intrinsic to megakaryocytes at the stage of proplatelet formation and suggest a functional link with the underlying microtubular cytoskeleton in platelet biogenesis.


Asunto(s)
Síndrome de Bernard-Soulier/metabolismo , Células Progenitoras de Megacariocitos/metabolismo , Megacariocitos/metabolismo , Microtúbulos/metabolismo , Adulto , Animales , Síndrome de Bernard-Soulier/patología , Plaquetas/citología , Plaquetas/metabolismo , Células de la Médula Ósea/citología , Células de la Médula Ósea/metabolismo , Supervivencia Celular , Modelos Animales de Enfermedad , Femenino , Citometría de Flujo , Humanos , Cinética , Células Progenitoras de Megacariocitos/citología , Megacariocitos/citología , Megacariocitos/ultraestructura , Ratones , Ratones Noqueados , Microscopía Confocal , Microscopía Electrónica de Rastreo , Microscopía Electrónica de Transmisión , Microscopía Fluorescente , Complejo GPIb-IX de Glicoproteína Plaquetaria/genética , Complejo GPIb-IX de Glicoproteína Plaquetaria/metabolismo , Factores de Tiempo , Adulto Joven
6.
Nat Commun ; 6: 6535, 2015 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-25779105

RESUMEN

PI3KC2α is a broadly expressed lipid kinase with critical functions during embryonic development but poorly defined roles in adult physiology. Here we utilize multiple mouse genetic models to uncover a role for PI3KC2α in regulating the internal membrane reserve structure of megakaryocytes (demarcation membrane system) and platelets (open canalicular system) that results in dysregulated platelet adhesion under haemodynamic shear stress. Structural alterations in the platelet internal membrane lead to enhanced membrane tether formation that is associated with accelerated, yet highly unstable, thrombus formation in vitro and in vivo. Notably, agonist-induced 3-phosphorylated phosphoinositide production and cellular activation are normal in PI3KC2α-deficient platelets. These findings demonstrate an important role for PI3KC2α in regulating shear-dependent platelet adhesion via regulation of membrane structure, rather than acute signalling. These studies provide a link between the open canalicular system and platelet adhesive function that has relevance to the primary haemostatic and prothrombotic function of platelets.


Asunto(s)
Plaquetas/metabolismo , Regulación de la Expresión Génica , Fosfatidilinositol 3-Quinasas/metabolismo , Estrés Mecánico , Alelos , Animales , Trasplante de Médula Ósea , Adhesión Celular , Cruzamientos Genéticos , Genotipo , Hemostasis , Humanos , Ratones , Ratones Endogámicos C57BL , Microscopía Electrónica de Transmisión , Mutación , Perfusión , Fosforilación , Adhesividad Plaquetaria , Agregación Plaquetaria , Resistencia al Corte , Transducción de Señal , Trombosis/genética , Trombosis/metabolismo
7.
Invest Ophthalmol Vis Sci ; 51(1): 369-74, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19684003

RESUMEN

PURPOSE: To develop a technique by which murine cytomegalovirus (MCMV) infection can be confirmed and monitored in vivo in various ocular compartments and to investigate the dynamics and time course of primary ocular CMV infection. METHODS: The ability of recombinant MCMV-expressing enhanced green fluorescent protein (eGFP) to serve as a tool to monitor the in vivo dynamics of experimental intraocular CMV infection was examined. Immunocompetent BALB/c mice were infected subretinally with eGFP-MCMV. Confocal scanning laser ophthalmoscopy (SLO) was used to visualize viral spread in vivo on sequential days after infection. Eyes were processed for histology and immunofluorescence microscopy to confirm viral infection and replication by means of GFP signal. RESULTS: Retina was readily permissive to primary infection with eGFP-mCMV, and fluorescent signal was detected by SLO 24 hours after subretinal injection, with scattered foci around the posterior pole of the retina. GFP levels in the retina reached a maximum on day 6. Signal in the iris developed from day 4 and lasted until day 25. Examinations of retinal and iris tissue wholemounts by immunofluorescence revealed signal localized to the outer retina, iris stroma, and anterior lens capsule. CONCLUSIONS: The ability to noninvasively monitor infectious agents in the eye may improve current knowledge of the course and pathogenesis of intraocular infections and could lead to further clarification of the mechanisms by which the immune system responds to intraocular pathogens.


Asunto(s)
Retinitis por Citomegalovirus/diagnóstico , Proteínas Fluorescentes Verdes , Infecciones por Herpesviridae/diagnóstico , Microscopía Confocal , Muromegalovirus/fisiología , Animales , Retinitis por Citomegalovirus/virología , Modelos Animales de Enfermedad , Femenino , Angiografía con Fluoresceína , Técnica del Anticuerpo Fluorescente Indirecta , Infecciones por Herpesviridae/virología , Iris/virología , Cápsula del Cristalino/virología , Ratones , Ratones Endogámicos BALB C , Microscopía Fluorescente , Retina/virología , Replicación Viral/fisiología
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