Decrease in PTEN and increase in Akt expression and neuron size in aged rat spinal cord

PTEN is a tumor suppressor gene known to play an important role in the regulation of cell size. In this study we compared PTEN expression in the spinal cord of young (5 months old) vs. aged (32 months old) female rats and correlated them with alterations in neuron size and morphology in the same animals. Total and phosphorylated PTEN (pPTEN) as well as its downstream target phosphorylated Akt (pAkt) were assessed by Western blotting. Spinal cord neurons were morphometrically characterized. Total PTEN, pPTEN and total Akt expression were significantly higher in young rats than in aged animals. Expression of pAkt was stronger in aged animals. A significant increase in neuronal size was observed in large motoneurons of aged as compared with young rats. Our data show that in the spinal cord of rats, neuronal PTEN expression diminishes with advanced age while neuronal size increases. These results suggest that in the spinal cord, an age-related reduction in PTEN and increase of pAkt expression may be involved in the progressive enlargement of neurons.INIBIOLPFacultad de Ciencias Veterinaria

Estradiol-dependent axogenesis and Ngn3 expression are determined by XY sex chromosome complement in hypothalamic neurons

Hypothalamic neurons show sex differences in neuritogenesis, female neurons have longer axons and higher levels of the neuritogenic factor neurogenin 3 (Ngn3) than male neurons in vitro. Moreover, the effect of 17-β-estradiol (E2) on axonal growth and Ngn3 expression is only found in male-derived neurons. To investigate whether sex chromosomes regulate these early sex differences in neuritogenesis by regulating the E2 effect on Ngn3, we evaluated the growth and differentiation of hypothalamic neurons derived from the “four core genotypes” mouse model, in which the factors of “gonadal sex” and “sex chromosome complement” are dissociated. We showed that sex differences in neurite outgrowth are determined by sex chromosome complement (XX > XY). Moreover, E2 increased the mRNA expression of Ngn3 and axonal length only in XY neurons. ERα/β expressions are regulated by sex chromosome complement; however, E2-effect on Ngn3 expression in XY neurons was only fully reproduced by PPT, a specific ligand of ERα, and prevented by MPP, a specific antagonist of ERα. Together our data indicate that sex chromosomes regulate early development of hypothalamic neurons by orchestrating not only sex differences in neuritogenesis, but also regulating the effect of E2 on Ngn3 expression through activation of ERα in hypothalamic neurons.Fil: Cisternas, Carla Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Cabrera Zapata, Lucas Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Mir, Franco Rafael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Scerbo, María Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Arevalo, María Angeles. Instituto de Salud Carlos Iii (isciii); EspañaFil: García-Segura, Luis Miguel. Instituto de Salud Carlos Iii (isciii); EspañaFil: Cambiasso, Maria Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; Argentin

Gonadal hormones and the control of reactive gliosis

Astrocytes and microglia respond to central nervous system (CNS) injury with changes in morphology, proliferation, migration and expression of inflammatory regulators. This phenomenon is known as reactive gliosis. Activation of astrocytes and microglia after acute neural insults, such as stroke or traumatic CNS injury, is considered to be an adaptive response that contributes to minimize neuronal damage. However, reactive gliosis may amplify CNS damage under chronic neurodegenerative conditions. Progesterone, estradiol and testosterone have been shown to control reactive gliosis in different models of CNS injury, modifying the number of reactive astrocytes and reactive microglia and the expression of anti-inflammatory and proinflammatory mediators. The actions of gonadal hormones on reactive gliosis involve different mechanisms, including the modulation of the activity of steroid receptors, such as estrogen receptors a and 13, the regulation of nuclear factor-kappa B mediated transcription of inflammatory molecules and the recruitment of the transcriptional corepressor c-terminal binding protein to proinflammatory promoters. In addition, the Parkinson's disease related gene parkin and the endocannabinoid system also participate in the regulation of reactive gliosis by estradiol. The control exerted by gonadal hormones on reactive gliosis may affect the response of neural tissue to trauma and neurodegeneration and may contribute to sex differences in the manifestation of neurodegenerative diseases. However, the precise functional consequences of the regulation of reactive gliosis by gonadal hormones under acute and chronic neurodegenerative conditions are still not fully clarified. (C) 2012 Elsevier Inc. All rights reserved

Notch signaling in astrocytes mediates their morphological response to an inflammatory challenge

In the nervous system, Notch pathway has a prominent role in the control of neuronal morphology and in the determination of the astrocyte fate. However, the role of Notch in morphological astrocyte plasticity is unknown. Here, we have explored the role of Notch activity on the morphological reactivity of primary astrocytes in response to LPS, an inflammatory stimulus. We found that LPS induces reactive astrocyte morphology by the inhibition of Notch signaling via NFκB activation and Jagged upregulation. In contrast, IGF-1, an anti-inflammatory molecule, inhibits LPS-induced reactive astrocyte morphological phenotype by enhancing Notch signaling through the inhibition of NFκB and the activation of MAPK. Therefore, Notch signaling pathway emerges as a mediator of the regulation of astrocyte morphology by inflammatory and anti-inflammatory stimuli

Mapeo de la percepción individual y del entorno organizacional para la práctica clínica basada en la evidencia entre enfermeras renales en España

Objetivo: Analizar la percepción de las enfermeras renales en España en relación con el entorno organizacional para la práctica clínica basada en la evidencia (PCBE); y determinar qué factores profesionales y del contexto influenyen esta percepción. Material y Método: Estudio observacional transversal multiéntrico, en 15 servicios de nefrología de distitos hospitales en España y 2 centros de diálisis. Se utilizaron los instrumentos Practice Environment Scale of Nursing Work Index (PES-NWI) y Evidence Based Practice Questionnarie (EBPQ). Se realizó un análisis estadístio descriptivo, bivariado (ANOVA, Kruskall-Wallis), y regresión logística con la puntuación total del EBPQ como variable dependiente. Resultados: Se recibieron 397 encuestas (participación84,28%), tras depuración encuestas, fueron válidas 382 (81,1% población): 82,7% mujeres, edad media 42 años, media de experiencia profesional como enfermera 18,2 años (12,2 años en nefrología), 94,8% clínicas, 81,9% de hemodiálisis. Puntuación media PES-NWI 62,35±15,10 (IC:95% 60,78-48,06). Presentaron menores puntuaciones en algunos factores del PES-NWI las enfermeras de centros >500 enfermeras, que trabajan en hemodiálisis y >11 años de experiencia profesional. Las enfermeras gestoras presentaron mayores puntuaciones en todos los factores del PES-NWI. Puntuación media EBPQ 81,05±21,92 (IC:95% 78,70-83,4). Presentaron mayores puntuaciones en varios factores del EBPQ las enfermeras con menor experiencia profesional, mejor puntuación en PES-NWI y que poseían estudios de postgrado. Conclusiones: Los factores que más influyen en la percepción de las enfermeras renales en España son la experiencia profesional, el rol dentro de la organización, un contexto favorable y la formación de postgrado

Prevalence of Hyperuricemia and Its Association with Cardiovascular Risk Factors and Subclinical Target Organ Damage

The role of uric acid levels in the cardiovascular continuum is not clear. Our objective is to analyze the prevalence of hyperuricemia (HU) and its association with cardiovascular risk factors (CVRF), subclinical target organ damage (sTOD), and cardiovascular diseases (CVD). We evaluated the prevalence of HU in 6.927 patients included in the baseline visit of the IBERICAN study. HU was defined as uric acid levels above 6 mg/dL in women, and 7 mg/dL in men. Using adjusted logistic regression models, the odds ratios were estimated according to CVRF, sTOD, and CVD. The prevalence of HU was 16.3%. The risk of HU was higher in patients with pathological glomerular filtration rate (aOR: 2.92), heart failure (HF) (aOR: 1.91), abdominal obesity (aOR: 1.80), hypertension (HTN) (aOR: 1.65), use of thiazides (aOR: 1.54), left ventricular hypertrophy (LVH) (aOR: 1.36), atrial fibrillation (AFIB) (aOR: 1.29), and albuminuria (aOR: 1.27). On the other hand, being female (aOR: 0.82) showed a reduced risk. The prevalence of HU was higher in men, in patients presenting CVRF such as HTN and abdominal obesity, and with co-existence of LVH, atrial fibrillation (AFIB), HF, and any form of kidney injury. These associations raise the possibility that HU forms part of the early stages of the cardiovascular continuum. This may influence its management in Primary Healthcare because the presence of HU could mean an increased CV risk in the patients