Search results for "Cholestérol"

Actualités en micronutrition : piste du cholestérol … vers un modèle animal de DMLA ?

2011

Cholesterol metabolism via cyp46a1 in glaucoma

2012

Cholesterol metabolism via cyp46a1 in glaucoma. International society for eye research (ISER) annual meeting

Développement de méthodes de référence pour les biomarqueurs du bilan lipidique : application au contrôle qualité en biologie clinique

2013

Reliable measurements in medical biology are essential for early screening and appropriate follow-up of patients. Ensuring metrological traceability of clinical measurements to higher order reference methods or certified reference materials enables to obtain comparable results over time and between different laboratories that could use different methods to quantify the same biomarker.In this study, reference methods were developed and validated for lipid profile biomarkers (total cholesterol, triglycerides, HDL-C, and LDL-C). Their value added in proficiency testing schemes was demonstrated against consensus mean. They were also used to characterize a certified reference material (CRM) that…

Cholestérol-24S-hydroxylase (CYP46A1) et homéostasie du cholestérol dans la rétine en conditions physiologiques et pathologiques

2012

Cholesterol is the major sterol found in the retina. In its free form, cholesterol is present in all cell layers of the retina, whereas cholesteryl esters mainly accumulate at the basement of the retinal pigment epithelium. The intrinsic capacity of the retina to synthetize cholesterol appears limited. Some extra-retinal pathways actively participate to cholesterol uptake to the retina. Müller glial cells may contribute to cholesterol supply to retinal neurons, especially for synaptic formation. Cholesterol accumulation or conversely deficiency have deleterious consequences on neuron survival. Maintaining the equilibrium between cholesterol supply and neosynthesis in the one hand and choles…

Regulation of the activity of the Cholesteryl Ester Tranfer Protein (CETP) : electrostatics interactions with carboxylic derivatives (Non Esterified …

1997

In human plasma, the cholesteryl ester transfer protein (CETP) plays a key role in lipoprotein metabolism by promoting the net mass transfer of cholesteryl esters from HDL towards apoB-containing lipoproteins, and the transfer of triglycerides from VLDL towards HDL and LDL. Thus CETP arises as a potentially important factor in plasma lipoproteins metabolism, a statement which raised a considerable interest in identifying the factors which may regulate CETP activity.In our in vitro studies, we demonstrated that amphipathic molecules (non esterified fatty acids and retinoic acids) constituted of one carboxylic head group and one hydrophobic carbon chain are able to increase the cholesteryl es…

Cholesterol and ocular pathologies: focus on the role of cholesterol-24S-hydroxylase in cholesterol homeostasis

2015

The retina is responsible for coding the light stimulus into a nervous signal that is transferred to the brain via the optic nerve. The retina is formed by the association of the neurosensory retina and the retinal pigment epithelium that is supported by Bruch’s membrane. Both the physical and metabolic associations between these partners are crucial for the functioning of the retina, by means of nutrient intake and removal of the cell and metabolic debris from the retina. Dysequilibrium are involved in the aging processes and pathologies such as age-related macular degeneration, the leading cause of visual loss after the age of 50 years inWestern countries. The retina is composed of severa…

Cholesterol homeostasis and retinal stress in anterior ischemic optic neuropathy

2016

Purpose: Anterior ischemic optic neuropathy (AION) is characterized by acute stress of retinal ganglion cells (RGC). Cholesterol-24S-hydroxylase (CYP46A1) is specifically expressed in RGC where it may exert neuroprotective properties by preventing from cholesterol accumulation via catalyzing the formation of 24S-hydroxycholesterol. Previous findings hypothesize the housekeeping importance of CYP46A1 in the maintenance of cholesterol in the retina. In order to better understand the role of CYP46A1 in the retina, we aimed to define whether CYP46A1 expression and 24S-hydroxycholesterol levels were modified during RGC stress in AION.Methods: Ninety nine male Sprague Dawley rats were randomized …