purpose. Oxidative stress has been proposed as a major pathogenic factor in age-related macular degeneration (AMD), the leading cause of vision loss among elderly people western European ancestry. Lutein (LUT) and zeaxanthin (ZEA), components pigment, are retinal antioxidants. Though xanthophyll intake may reduce likelihood having advanced AMD, direct evidence neuroprotection is lacking. Prior work shown that docosahexaenoic acid (DHA), polyunsaturated fatty retina, delays apoptosis promotes...

In a recent study, it was demonstrated that docosahexaenoic acid (DHA) promotes the survival of retinal photoreceptors in vitro, delaying apoptosis. However, lipid enrichment DHA is known to contribute retina vulnerability oxidative stress. this effect damage on rat neurons vitro and whether enhances or diminishes were investigated.Rat 3-day cultures, with without DHA, treated oxidant paraquat. After 24 hours, apoptosis, mitochondrial membrane integrity, Bcl-2 Bax expression...

Abstract: When rat retinal cells are cultured in a serum‐free medium, the photoreceptor start dying after 7 days. The addition of docosahexaenoic acid (DHA) to cultures prevents selective death photoreceptors. Here it is shown that, unlike other neurons, photoreceptors die through an apoptotic pathway. Hallmarks apoptosis, such as nuclear fragmentation and condensation DNA cleavage forming ladder pattern on agarose gel, were observed. timing high selectivity triggering cell apoptosis suggest...

Abstract: The effect of docosahexaenoic acid (DHA) on neuronal survival was studied in cultured cells isolated from newborn rat retina. In vivo, the content DHA retina increased nearly fourfold days 2 to 12 after birth, whereas retinal culture it remained constant. Unlike amacrine cells, photoreceptor control cultures underwent a selective degeneration, starting at day 7, that led their massive death by 11. addition 7 its active incorporation cultures, increasing 6 21% total fatty acids cell...

Abstract Identifying the trophic factors for retina photoreceptors and intracellular pathways activated to promote cell survival is crucial treating neurodegenerative diseases. Docosahexaenoic acid (DHA), major retinal polyunsaturated fatty acid, prevents photoreceptor apoptosis during early development in vitro , upon oxidative stress. However, signaling mechanisms by DHA are still unclear. We investigated whether extracellular signal regulated kinase (ERK)/mitogen‐activated protein (MAPK)...

Eye movements follow a reproducible pattern during normal reading. Each eye movement ends up in fixation point, which allows the brain to process incoming information and program following saccade. Alzheimer disease (AD) produces abnormalities disturbances In this work, we investigated whether alterations reading might be already present at very early stages of disease.Twenty female male adult patients with diagnosis probable AD 20 age-matched individuals no evidence cognitive decline...

Abstract We have recently shown that docosahexaenoic acid (DHA) is necessary for survival and differentiation of rat retinal photoreceptors during development in vitro . In cultures lacking DHA, neurons developed normally 4 d; then selectively started an apoptotic pathway leading to extensive degeneration these cells by day 11. DHA protected delaying the onset apoptosis; addition, it advanced photoreceptor differentiation, promoting opsin expression inducing apical neurons. was only fatty...

Abstract Oxidative damage is involved in triggering neuronal death several retinal neurodegenerative diseases. The recent finding of stem cells the retina suggests that both preventing and replacing lost neurons might be useful strategies for treating these We have previously shown oxidative stress induces apoptosis cultured neurons. now investigated response Müller cells, proposed as to this damage. Treatment glial cell cultures prepared from rat retinas with oxidant paraquat (PQ) did not...

Oxidative stress is involved in inducing apoptosis of photoreceptors many retinal neurodegenerative diseases. It has been shown that oxidative increases the synthesis ceramide, a sphingolipid precursor then activates apoptosis. In several cell types, ceramide converted by ceramidases to sphingosine (Sph), another mediator; hence, this study was undertaken determine whether Sph participates triggering photoreceptor apoptosis.Rat retina neurons were incubated with [(3)H]palmitic acid and...

We have established that docosahexaenoic acid (DHA), the major polyunsaturated fatty in retina, promotes survival of rat retina photoreceptors during early development vitro and upon oxidative stress by activating ERK/MAPK signaling pathway. Here we investigated whether DHA turns on this pathway through activation retinoid X receptors (RXRs) or inducing tyrosine kinase (Trk) receptor activation. also evaluated release from phospholipids was required for its protective effect. Addition RXR...

Oxidative stress is involved in activating photoreceptor death several retinal degenerations. Docosahexaenoic acid (DHA), the major polyunsaturated fatty retina, protects cultured retina photoreceptors from apoptosis induced by oxidative and promotes differentiation. Here, we investigated whether eicosapentaenoic (EPA), a metabolic precursor to DHA, had similar effects neurons could metabolize EPA DHA. Adding rat neuronal cultures increased opsin expression protected oxidants paraquat...

purpose. Identifying the cues required for survival and development of photoreceptors is essential treating retinal neurodegeneration. The authors previously established that glial-derived neurotrophic factor (GDNF) stimulates proliferation docosahexaenoic acid (DHA) promotes photoreceptor differentiation. Later findings ceramide triggers apoptosis suggested sphingolipids might also control development. present study investigated whether sphingosine-1-phophate (S1P), which differentiation in...

Purpose.: Simple sphingolipids control crucial cellular processes in several cell types. Previous work demonstrated that sphingolipids, such as ceramide, sphingosine, and sphingosine-1-phosphate, are key mediators the regulation of survival, differentiation, proliferation retina photoreceptors. Ceramide-1-phosphate (C1P) regulates growth survival types; however, little is known concerning its functions retina. Whether C1P also participates controlling photoreceptor development was explored....

Patients with Alzheimer's disease (AD) develop progressive language, visuoperceptual, attentional, and oculomotor changes that can have an impact on their reading comprehension. However, few studies examined behavior in AD, none the contribution of predictive cueing i n performance. For this purpose we analyzed eye movement 35 healthy readers (Controls) patients probable AD during regular high-predictable sentences. The cloze predictability words N – 1, + 1 exerted influence reader's gaze...

In this study we show that insulin‐like growth factor (IGF)‐I selectively promotes survival and differentiation of amacrine neurons. cultures lacking factor, an initial degeneration pathway, affecting neurons, led to no lamellipodia development little axon outgrowth. Cell lysis initially affected 50% neurons; those remaining underwent apoptosis leading the death approximately 95% them by day 10. Apoptosis was preceded a marked increase in c‐Jun expression. Addition IGF‐I or high...

purpose. A recent study has shown that glia-derived neurotrophic factor (GDNF) and docosahexaenoic acid (DHA) promote the survival differentiation of retina photoreceptors. The current was undertaken to investigate whether these molecules participate in cell cycle regulation retinal progenitors vitro. methods. Developmental changes expression stem marker nestin differentiated neuron markers were analyzed neuroblasts obtained from 1-day-old rat retinas. effects GDNF DHA on those then...

The precise molecular cues required for photoreceptor development are still unknown. Pax6 and Crx essential during early retinal differentiation, respectively. lipid molecule docosahexaenoic acid (DHA) has also been shown to promote differentiation. expression the steps in whether mutual contribution of DHA enhances differentiation were investigated.Neuroblast proliferation, Crx, investigated rat retinas vivo neuronal cultures with or without DHA. BrdU incorporation, nestin opsin expression,...

Abstract Retina differentiation involves the acquisition of a precise layered arrangement, with RPE cells in first layer intimate contact photoreceptors second layer. Here, we developed an vitro coculture model, to test hypothesis that play pivotal role organizing spatial structure retina. We cocultured rat retinal neurons ARPE‐19 epithelial under various experimental conditions. Strikingly, when seeded over cells, attached their apical surfaces and proceeded development, including increased...

Purpose: Migration of Müller glial cells is enhanced in proliferative retinopathies, but the mechanisms involved are ill defined. Sphingosine-1-phosphate (S1P) a bioactive sphingolipid synthesized by sphingosine kinase (SphK), which promotes proliferation, migration, and inflammation, acting as an intracellular mediator activating family membrane receptors (S1PRs). We investigated whether S1P regulated migration. Methods: cell cultures from rat retinas were supplemented with 5 μM S1P,...