Impact of Iron Intake and Reserves on Cognitive Function in Young University Students.

Iron is a key nutrient for cognitive function. During periods of high academic demand, brain and cognitive activity increase, potentially affecting iron intake and reserves. The present study aimed to investigate the impact of iron levels on cognitive function in a university sample, considering the influence of gender.

Neuroprotective Effects of Resveratrol by Modifying Cholesterol Metabolism and Aβ Processing in SAMP8 Mice.

Cholesterol metabolism seems dysregulated and linked to amyloid-β (Aβ) formation in neurodegeneration, but the underlying mechanisms are poorly known. Resveratrol (RSV) is a polyphenol with antioxidant activity and neuroprotective properties. Here, we analyzed the effect of age and RSV supplementation on cholesterol metabolism in the brain and blood serum, and its potential link to Aβ processing, in SAMP8 mice-an animal model of aging and Alzheimer's disease.

High-Fat and Resveratrol Supplemented Diets Modulate Adenosine Receptors in the Cerebral Cortex of C57BL/6J and SAMP8 Mice.

Neurodegenerative disorders are devastating diseases in which aging is a major risk factor. High-fat diet (HFD) seems to contribute to cognition deterioration, but the underlying mechanisms are poorly understood. Moreover, resveratrol (RSV) has been reported to counteract the loss of cognition associated with age.

Antitumoral Action of Resveratrol Through Adenosinergic Signaling in C6 Glioma Cells.

Gliomas are the most common and aggressive primary tumors in the central nervous system. The nucleoside adenosine is considered to be one major constituent within the tumor microenvironment. The adenosine level mainly depends on two enzymatic activities: 5'-nucleotidase (5'NT or CD73) that synthesizes adenosine from AMP, and adenosine deaminase (ADA) that converts adenosine into inosine.

Early Effects of the Soluble Amyloid β Peptide in Rat Cortical Neurons: Modulation of Signal Transduction Mediated by Adenosine and Group I Metabotropic Glutamate Receptors.

The amyloid β peptide (Aβ) is a central player in the neuropathology of Alzheimer's disease (AD). The alteration of Aβ homeostasis may impact the fine-tuning of cell signaling from the very beginning of the disease, when amyloid plaque is not deposited yet. For this reason, primary culture of rat cortical neurons was exposed to Aβ, a non-oligomerizable form of Aβ.

Modulation of Adenosine Receptors by Hops and Xanthohumol in Cell Cultures.

Adenosine receptors (ARs) have been involved in neurodegenerative diseases such as Alzheimer disease, where oxidative stress contributes to neurodegeneration and cell death. Therefore, there is increasing interest in developing antioxidative strategies to avoid or reduce neurodegeneration. We have previously described that different beer extracts modulate ARs and protect glioma and neuroblastoma cells from oxidative stress.

The Density of Group I mGlu Receptors Is Reduced along the Neuronal Surface of Hippocampal Cells in a Mouse Model of Alzheimer's Disease.

Metabotropic glutamate receptor subtype 5 (mGlu) is implicated in the pathophysiology of Alzheimer´s disease (AD). However, its alteration at the subcellular level in neurons is still unexplored. Here, we provide a quantitative description on the expression and localisation patterns of mGlu in the APP/PS1 model of AD at 12 months of age, combining immunoblots, histoblots and high-resolution immunoelectron microscopic approaches.

Adenosine Metabolism in the Cerebral Cortex from Several Mice Models during Aging.

Adenosine is a neuromodulator that has been involved in aging and neurodegenerative diseases as Alzheimer's disease (AD). In the present work, we analyzed the possible modulation of purine metabolites, 5'nucleotidase (5'NT) and adenosine deaminase (ADA) activities, and adenosine monophosphate (AMP)-activated protein kinase (AMPK) and its phosphorylated form during aging in the cerebral cortex. Three murine models were used: senescence-accelerated mouse-resistant 1 (SAMR1, normal senescence), senescence-accelerated mouse-prone 8 (SAMP8, a model of AD), and the wild-type C57BL/6J (model of aging) mice strains.

Adenosine and Metabotropic Glutamate Receptors Are Present in Blood Serum and Exosomes from SAMP8 Mice: Modulation by Aging and Resveratrol.

Adenosine (ARs) and metabotropic glutamate receptors (mGluRs) are G-protein coupled receptors (GPCRs) that are modulated in the brain of SAMP8 mice, an animal model of Alzheimer's disease (AD). In the present work, it is shown the presence of ARs and mGluRs in blood serum and derived exosomes from SAMP8 mice as well as its possible modulation by aging and resveratrol (RSV) consumption. In blood serum, adenosine A and A receptors remained unaltered from 5 to 7 months of age.

Modulation of Adenosine Receptors and Antioxidative Effect of Beer Extracts in in Vitro Models.

The fight against neurodegenerative diseases is promoting the searching of nutrients, preferably of wide consumption, with proven effects on health. Beer is widely consumed and has potential benefits on health. In this work, three different extracts from dark beer (DB), non-alcoholic beer (NAB), and lager beer (LB) were assayed at 30 min and 24 h in rat C6 glioma and human SH-SY5Y neuroblastoma cells in order to study their possible protective effects.

The antioxidant resveratrol acts as a non-selective adenosine receptor agonist.

Resveratrol (RSV) is a natural polyphenolic antioxidant with a proven protective role in several human diseases involving oxidative stress, although the molecular mechanism underlying this effect remains unclear. The present work tried to elucidate the molecular mechanism of RSV's role on signal transduction modulation. Our biochemical analysis, including radioligand binding, real time PCR, western blotting and adenylyl cyclase activity, and computational studies provide insights into the RSV binding pathway, kinetics and the most favored binding pose involving adenosine receptors, mainly A subtype.

Strong Influence of Ancillary Ligands Containing Benzothiazole or Benzimidazole Rings on Cytotoxicity and Photoactivation of Ru(II) Arene Complexes.

A new family of neutral ruthenium(II) arene complexes of the type [Ru(η-arene)X(κ- O, N-L)] (η-arene = p-cym, bz; X = Cl, SCN; HL1 = 2-(2'-hydroxyphenyl)benzimidazole, HL2 = 2-(2'-hydroxyphenyl)benzothiazole) has been synthesized and characterized. The cytotoxic activity of the Ru(II) complexes was evaluated in several tumor cell lines (A549, HepG2 and SW480) both in the dark and after soft irradiation with UV and blue light. None of the complexes bearing benzimidazole (HL1) as a ligand displayed phototoxicity, whereas the complexes with a benzothiazole ligand (HL2) exhibited photoactivation; the sensitivity observed for UV was higher than for blue light irradiation.

Resveratrol Modulates and Reverses the Age-Related Effect on Adenosine-Mediated Signalling in SAMP8 Mice.

Resveratrol (RSV) is a natural compound present in berries, grapes and red wine that has shown some neuroprotective properties, but the mechanism by which RSV exhibits its protective role is not very well understood yet. Little is known about the effect of RSV on adenosinergic system, a system regulated in an age-dependent manner in SAMP8 mice, widely considered as an Alzheimer's model. Therefore, the aim of the present work was to assess whether RSV intake was able to modulate the adenosine-mediated signalling in SAMP8 mice.

Functional Cross-Talk between Adenosine and Metabotropic Glutamate Receptors.

G-protein coupled receptors are transmembrane proteins widely expressed in cells and their transduction pathways are mediated by controlling second messenger levels through different G-protein interactions. Many of these receptors have been described as involved in the physiopathology of neurodegenerative diseases and even considered as potential targets for the design of novel therapeutic strategies. Endogenous and synthetic allosteric and orthosteric selective ligands are able to modulate GPCRs at both gene and protein expression levels and can also modify their physiological function.

Purine-related metabolites and their converting enzymes are altered in frontal, parietal and temporal cortex at early stages of Alzheimer's disease pathology.

Adenosine, hypoxanthine, xanthine, guanosine and inosine levels were assessed by HPLC, and the activity of related enzymes 5'-nucleotidase (5'-NT), adenosine deaminase (ADA) and purine nucleoside phosphorylase (PNP) measured in frontal (FC), parietal (PC) and temporal (TC) cortices at different stages of disease progression in Alzheimer's disease (AD) and in age-matched controls. Significantly decreased levels of adenosine, guanosine, hypoxanthine and xanthine, and apparently less inosine, are found in FC from the early stages of AD; PC and TC show an opposing pattern, as adenosine, guanosine and inosine are significantly increased at least at determinate stages of AD whereas hypoxanthine and xanthine levels remain unaltered. 5'-NT is reduced in membranes and cytosol in FC mainly at early stages but not in PC, and only at advanced stages in cytosol in TC.

Membrane cholesterol access into a G-protein-coupled receptor.

Cholesterol is a key component of cell membranes with a proven modulatory role on the function and ligand-binding properties of G-protein-coupled receptors (GPCRs). Crystal structures of prototypical GPCRs such as the adenosine A receptor (AR) have confirmed that cholesterol finds stable binding sites at the receptor surface suggesting an allosteric role of this lipid. Here we combine experimental and computational approaches to show that cholesterol can spontaneously enter the AR-binding pocket from the membrane milieu using the same portal gate previously suggested for opsin ligands.

Chronic oral administration of MPEP, an antagonist of mGlu receptor, during gestation and lactation alters mGlu and A receptors in maternal and neonatal brain.

Antidepressant and anxiolytic drugs are widely consumed even by pregnant and lactating women. The metabotropic glutamate receptor 5 (mGlu) antagonist 2-methyl-6-(phenylethynyl)-pyridine (MPEP) exerts antidepressant- and anxiolytic-like actions. Given that treatment for anxiety and depression use to be prolonged in time, it is conceivable a possible modulation of metabotropic glutamate receptors (mGlu receptors) after prolonged MPEP exposure, which could also modify adenosine A receptors (AR) since functional cross-talk between them has been reported.

2-Methyl-6-(phenylethynyl)pyridine Hydrochloride Modulates Metabotropic Glutamate 5 Receptors Endogenously Expressed in Zebrafish Brain.

Due to phylogenetic proximity to the human, zebrafish has been recognized as a reliable model to study Alzheimer's disease (AD) and other central nervous system disorders. Furthermore, metabotropic glutamate receptors have been previously reported to be impaired in brain from AD patients. Metabotropic glutamate 5 (mGlu) receptors are G-protein coupled receptors proposed as potential targets for therapy of different neurodegenerative disorders.

Hyperthermia-induced seizures alter adenosine A1 and A2A receptors and 5'-nucleotidase activity in rat cerebral cortex.

Febrile seizure is one of the most common convulsive disorders in children. The neuromodulator adenosine exerts anticonvulsant actions through binding adenosine receptors. Here, the impact of hyperthermia-induced seizures on adenosine A1 and A2A receptors and 5'-nucleotidase activity has been studied at different periods in the cerebral cortical area by using radioligand binding, real-time PCR, and 5'-nucleotidase activity assays.

Effect of Caffeine Chronically Consumed During Pregnancy on Adenosine A and A Receptors Signaling in Both Maternal and Fetal Heart from Wistar Rats.

Caffeine is the most widely consumed psychoactive substance in the world, even during pregnancy. Its stimulatory effects are mainly due to antagonism of adenosine actions by blocking adenosine A and A receptors. Previous studies have shown that caffeine can cross the placenta and therefore modulate these receptors not only in the fetal brain but also in the heart.

[60]Fullerene derivative modulates adenosine and metabotropic glutamate receptors gene expression: a possible protective effect against hypoxia.

Background: Glutamate, the main excitatory neurotransmitter, is involved in learning and memory processes but at higher concentration results excitotoxic causing degeneration and neuronal death. Adenosine is a nucleoside that exhibit neuroprotective effects by modulating of glutamate release. Hypoxic and related oxidative conditions, in which adenosine and metabotropic glutamate receptors are involved, have been demonstrated to contribute to neurodegenerative processes occurring in certain human pathologies.

Modulation of gene expression of adenosine and metabotropic glutamate receptors in rat's neuronal cells exposed to L-glutamate and [60]fullerene.

L-Glutamate (L-Glu) has been often associated not only to fundamental physiological roles, as learning and memory, but also to neuronal cell death and the genesis and development of important neurodegenerative diseases. Herein we studied the variation in the adenosine and metabotropic glutamate receptors expression induced by L-Glu treatment in rat's cortical neurons. The possibility to have structural alteration of the cells induced by L-Glu (100 nM, 1 and 10 microM) has been addressed, studying the modulation of microtubule associated protein-2 (MAP-2) and neurofilament heavy polypeptide (NEFH), natively associated proteins to the dendritic shape maintenance.