Search results for "Homeostasis"
showing 10 items of 630 documents
2015
The melanocortin system is one of the most important neuronal pathways involved in the regulation of food intake and is probably the best characterized. Agouti-related peptide (AgRP) and proopiomelanocortin (POMC) expressing neurons located in the arcuate nucleus of the hypothalamus are the key elements of this system. These two neuronal populations are sensitive to circulating molecules and receive many excitatory and inhibitory inputs from various brain areas. According to sensory and metabolic information they integrate, these neurons control different aspects of feeding behavior and orchestrate autonomic responses aimed at maintaining energy homeostasis. Interestingly, composition and a…
Elevated cortisol modulates hsp70 and hsp90 gene expression and protein in sea bass head kidney and isolated leukocytes
2012
In fish, interactions between Hsps and cortisol are involved in stress modulated physiological processes including innate immune responses. Cortisol exerts a role in the regulation of Hsps synthesis. Fish head kidney is a lymphomieloid and endocrine organ releasing cortisol, and it is the central organ for immune-endocrine interactions. In sea bass, cortisol intraperitoneal injection and in vitro treatment of head kidney cells show that inducible Hsp70 and Hsp90 are modulated by this hormone. However, an inverse relationship between mRNA expression (real-time PCR) and Hsp70 and Hsp90 protein levels (densitometric band analysis) was found. Time-course assays indicate a cortisol-mediated regu…
Glial Chloride Homeostasis Under Transient Ischemic Stress
2021
High water permeabilities permit rapid adjustments of glial volume upon changes in external and internal osmolarity, and pathologically altered intracellular chloride concentrations ([Cl–]int) and glial cell swelling are often assumed to represent early events in ischemia, infections, or traumatic brain injury. Experimental data for glial [Cl–]int are lacking for most brain regions, under normal as well as under pathological conditions. We measured [Cl–]int in hippocampal and neocortical astrocytes and in hippocampal radial glia-like (RGL) cells in acute murine brain slices using fluorescence lifetime imaging microscopy with the chloride-sensitive dye MQAE at room temperature. We observed s…
Impact of
2018
Drosophila melanogaster has been for over a century the model of choice of several neurobiologists to decipher the formation and development of the nervous system as well as to mirror the pathophysiological conditions of many human neurodegenerative diseases. The rare disease Friedreich’s ataxia (FRDA) is not an exception. Since the isolation of the responsible gene more than two decades ago, the analysis of the fly orthologue has proven to be an excellent avenue to understand the development and progression of the disease, to unravel pivotal mechanisms underpinning the pathology and to identify genes and molecules that might well be either disease biomarkers or promising targets for therap…
24S-hydroxycholesterol and cholesterol-24S-hydroxylase (CYP46A1) in the retina: from cholesterol homeostasis to pathophysiology of glaucoma.
2011
http://www.sciencedirect.com/; International audience; Free cholesterol is the predominant form of cholesterol in the neural retina. The vertebrate neural retina exhibits its own capacity to synthesize cholesterol and meets its demand also by taking it from the circulation. Defects in cholesterol synthesis and trafficking in the neural retina has detrimental consequences on its structure and function, highlighting the crucial importance of maintaining cholesterol homeostasis in the retina. Our purpose was to give a review on the functioning of the retina, the role of cholesterol and cholesterol metabolism therein, with special emphasis on cholesterol-24S-hydroxylase (CYP46A1). Similar to th…
In vivo consequences of cholesterol-24s-hydroxylase (CYP46A1) inhibition by voriconazole on cholesterol homeostasis and function in the rat retina
2011
Cholesterol 24S-hydroxylase (CYP46A1) converts cholesterol into 24S-hydroxycholesterol in neurons and participates in cholesterol homeostasis in the central nervous system, including the retina. We aimed to evaluate the consequences of CYP46A1 inhibition by voriconazole on cholesterol homeostasis and function in the retina. Rats received daily intraperitoneal injections of voriconazole (60mg/kg), minocycline (22mg/kg), voriconazole plus minocycline, or vehicle during five consecutive days. The rats were submitted to electroretinography to monitor retinal functionality. Cholesterol and 24S-hydroxycholesterol were measured in plasma, brain and retina by gas chromatography-mass spectrometry. T…
Efectos de la sobreexpresión de transportadores de cobre de alta afinidad tipo CTR en Saccharomyces cerevisiae, Arabidopsis thaliana y Oryza sativa
2019
En el presente trabajo se ha estudiado el efecto que tiene la desregulación de la entrada de Cu+ mediante la alteración y sobreexpresión de transportadores de cobre de alta afinidad, tipo Ctr en tres organismos: Saccharomyces cerevisiae, Arabidopsis thaliana y Oryza sativa. Los resultados obtenidos confirman que las homeostasis del cobre y del hierro están relacionadas, ya que la alteración de la entrada de Cu+ en las células afecta a diferentes aspectos de la percepción y el transporte de hierro. En el caso de Saccharomyces cerevisiae, se ha comprobado que la falta de control en la entrada de cobre en la cepa mutante CTR1Δ300 provoca cambios en la expresión de genes como los que codifican …
Desarrollo de formulaciones alimentarias basadas en Chenopodium quinoa y Salvia hispanica L. con función preventivo/terapéutica de trastornos en el m…
2021
El incremento de enfermedades relacionadas con alteraciones en la homeostasis de la glucosa (i.e., obesidad, diabetes, glucogenosis), ha generado un continuo interés en el consumo de la quinoa (Chenopodium quinoa) y la chía (Salvia hispanica L.). Por ello, se ha estudiado en un primer objetivo el almidón de quinoa comparado con otros almidones comerciales (patata, arroz, trigo, maíz), determinando sus propiedades térmicas y de pasta y el efecto del tratamiento hidrotérmico en sus cinéticas de liberación de glucosa, así como evaluar el efecto de añadir harina de chía desgrasada (H_Ch) en los flujos de glucosa y en la respuesta metabólica en células HepG2. Como segundo objetivo, se ha estudia…
Role of ghrelin and leptin in the regulation of carbohydrate metabolism. Part I. Ghrelin
2012
Grelina jest polipeptydem wydzielanym przez komórki wydzielnicze błony śluzowej żołądka i jelit, jądro łukowate podwzgórza, a także przez komórki epsilon (e), które znajdują się w obrębie wysp trzustkowych. Grelina odgrywa ważną rolę w utrzymywaniu homeostazy energetycznej organizmu oraz wpływa na wewnątrzwydzielniczą funkcję trzustki i metabolizm glukozy. W regulacji homeostazy glukozy grelina bierze udział poprzez modulację wydzielania isuliny, jak i wrażliwości na insulinę. Wobec różnorodnych biologicznych skutków działania greliny, obecne badania poświęca się potencjalnym możliwościom ich modyfikowania. Dużo uwagi skupiono wokół enzymu zwanego O-acylo transferazą greliny (ghrelin O-acyl…
The iron-regulatory hormone hepcidin: A possible therapeutic target?
2015
The maintenance of stable extracellular and intracellular iron concentrations requires the coordinated regulation of iron transport into plasma. Iron is a fundamental cofactor for several enzymes involved in oxidation-reduction reactions. The redox ability of iron can lead to the production of oxygen free radicals, which can damage various cellular components. Therefore, the appropriate regulation of systemic iron homeostasis is decisive in vital processes. Hepcidin has emerged as the central regulatory molecule of systemic iron homeostasis. It is synthesized in hepatocytes and in other cells and released into the circulation. It inhibits the release of iron from enterocytes of the duodenum…