Search results for " homeostasis"
showing 10 items of 312 documents
Neuronal inhibition of the autophagy nucleation complex extends lifespan in post-reproductive C. elegans
2017
AbstractAutophagy is a ubiquitous catabolic process, which causes cellular bulk degradation of cytoplasmic components and thereby regulates cellular homeostasis. Inactivation of autophagy has been linked with detrimental effects to cells and organisms. The antagonistic pleiotropy theory postulates that fitness promoting genes during youth are harmful during aging (Williams 1957). On this basis we examined genes mediating post-reproductive longevity using an RNA interference screen. From this screen we identified 30 novel regulators of post-reproductive longevity including pha-4. Through downstream analysis of pha-4 we identify that genes governing the early stages of autophagy up until the …
Focal Cortical Lesions Induce Bidirectional Changes in the Excitability of Fast Spiking and Non Fast Spiking Cortical Interneurons
2014
A physiological brain function requires neuronal networks to operate within a well-defined range of activity. Indeed, alterations in neuronal excitability have been associated with several pathological conditions, ranging from epilepsy to neuropsychiatric disorders. Changes in inhibitory transmission are known to play a key role in the development of hyperexcitability. However it is largely unknown whether specific interneuronal subpopulations contribute differentially to such pathological condition. In the present study we investigated functional alterations of inhibitory interneurons embedded in a hyperexcitable cortical circuit at the border of chronically induced focal lesions in mouse …
PINK1: a critical protein kinase in the molecular mechanisms involved in Cancer and Parkinson's disease
2012
El cáncer y la enfermedad de Parkinson (PD) son dos enfermedades en las que el mecanismo pato- fisiológico final no está completamente definido. Datos epidemiológicos indican que los pacientes con PD poseen bajo riesgo de cáncer, con la excepción de melanoma maligno y cánceres de piel, tiroides y mama, lo que sugiere una conexión funcional entre PD y cáncer. Apoyando esta conexión, la desregulación de la homeostasis mitocondrial es una característica importante en la patogénesis de ambas enfermedades. Recientemente, varios genes asociados a PD, tales como Parkin, LRRK2, DJ-1, y PINK1, han sido propuestos como moduladores de procesos cancerígenos. Mutaciones en el gen de PINK1 están asociada…
Bases psicobiológicas de la adicción a cocaína
2006
El principal mecanismo de acción de la cocaína es la inhibición de la recaptación de dopamina y noradrenalina, produciendo un aumento de estos neurotransmisores en la sinapsis. El consumo agudo de cocaína produce una serie de cambios bastante conocidos en el sistema cerebral de recompensa. Sin embargo, el consumo crónico, produce, además, otra serie de cambios a nivel molecular que llevan al sujeto desde una situación de consumo puntual, a una situación de dependencia. Se han propuesto diferentes teorías explicativas de este fenómeno como la sensibilización del incentivo, o la homeostasis y alostasis neuroquímica, planteamientos basados en el condicionamiento clásico y operante. Por otra pa…
Chicken adaptive response to low energy diet: main role of the hypothalamic lipid metabolism revealed by a phenotypic and multi-tissue transcriptomic…
2019
AbstractBackgroundProduction conditions of layer chicken can vary in terms of temperature or diet energy content compared to the controlled environment where pure-bred selection is undertaken. The aim of this study was to better understand the long-term effects of a 15%-energy depleted diet on egg-production, energy homeostasis and metabolism via a multi-tissue transcriptomic analysis. Study was designed to compare effects of the nutritional intervention in two layer chicken lines divergently selected for residual feed intake.ResultsChicken adapted to the diet in terms of production by significantly increasing their feed intake and decreasing their body weight and body fat composition, whil…
Common missense variant in the glucokinase regulatory protein gene is associated with increased plasma triglyceride and C-reactive protein but lower …
2008
OBJECTIVE—Using the genome-wide association approach, we recently identified the glucokinase regulatory protein gene (GCKR, rs780094) region as a novel quantitative trait locus for plasma triglyceride concentration in Europeans. Here, we sought to study the association of GCKR variants with metabolic phenotypes, including measures of glucose homeostasis, to evaluate the GCKR locus in samples of non-European ancestry and to fine- map across the associated genomic interval. RESEARCH DESIGN AND METHODS—We performed association studies in 12 independent cohorts comprising >45,000 individuals representing several ancestral groups (whites from Northern and Southern Europe, whites from the …
Physical Activity, Fitness, Glucose Homeostasis, and Brain Morphology in Twins
2014
The main aim of the present study (FITFATTWIN) was to investigate how physical activity level is associated with body composition, glucose homeostasis, and brain morphology in young adult male monozygotic twin pairs discordant for physical activity.From a population-based twin cohort, we systematically selected 10 young adult male monozygotic twin pairs (age range, 32-36 yr) discordant for leisure time physical activity during the past 3 yr. On the basis of interviews, we calculated a mean sum index for leisure time and commuting activity during the past 3 yr (3-yr LTMET index expressed as MET-hours per day). We conducted extensive measurements on body composition (including fat percentage …
The effect of growth hormone ( GH ) replacement on blood glucose homeostasis in adult nondiabetic patients with GH deficiency: real‐life data from th…
2015
SummaryObjective To assess the effect of 4 years’ growth hormone (GH) replacement on glucose homeostasis and evaluate factors affecting glycosylated haemoglobin (HbA1c) in adults with growth hormone deficiency (GHD). Design NordiNet® International Outcome Study, a noninterventional study, monitors long-term effectiveness and safety of GH replacement [Norditropin® (somatropin), Novo Nordisk A/S] in real-life clinical practice. Patients Nondiabetic patients (n = 245) with adult-onset GHD (age ≥20 years at GH start), ≥4 years’ GH replacement and HbA1c values at baseline and 4 years were included in the analysis. Measurements Changes from baseline (∆) to 4 years in HbA1c, fasting plasma glucose…
Extracellular Vesicles from Healthy Cells Improves Cell Function and Stemness in Premature Senescent Stem Cells by miR-302b and HIF-1α Activation.
2020
Aging is accompanied by the accumulation of senescent cells that alter intercellular communication, thereby impairing tissue homeostasis and reducing organ regenerative potential. Recently, the administration of mesenchymal stem cells (MSC)-derived extracellular vesicles has proven to be more effective and less challenging than current stem cell-based therapies. Extracellular vesicles (EVs) contain a cell-specific cargo of proteins, lipids and nucleic acids that are released and taken up by probably all cell types, thereby inducing functional changes via the horizontal transfer of their cargo. Here, we describe the beneficial properties of extracellular vesicles derived from non-senescent M…
Comparison of telomere length between population-specific mitochondrial haplogroups among different age groups in a Latvian population
2014
Population studies have demonstrated that telomere length (TL) displays great diversity among different populations. Previously described controversial findings associated longevity with specific mitochondrial DNA haplogroups (hgs) (e.g., J and U). These observations may be influenced by population diversity, geographic location, and/or specific historic background. The aims of this study were to identify a specific hg which correlates with aging in a Latvian populating and to evaluate the possible association of TL variability with specific mitochondrial hgs. The results show no significant correlation between TL, mitochondrial DNA hgs and longevity. A slight increase in frequency was obse…