Publications by authors named "Rafael Rodriguez Puertas"

Background And Purpose: Recent research linking choline-containing lipids to degeneration of basal forebrain cholinergic neurons in neuropathological states illustrates the challenge of balancing lipid integrity with optimal acetylcholine levels, essential for memory preservation. The endocannabinoid system influences learning and memory processes regulated by cholinergic neurotransmission. Therefore, we hypothesised that activation of the endocannabinoid system may confer neuroprotection against cholinergic degeneration.

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Some specific lipid molecules in the brain act as signaling molecules, neurotransmitters, or neuromodulators, by binding to specific G protein-coupled receptors (GPCR) for neurolipids. One such receptor, sphingosine 1-phosphate receptor subtype 1 (S1P), is coupled to G proteins and is involved in cell proliferation, growth, and neuroprotection. S1P constitutes an interesting target for neurodegenerative diseases like multiple sclerosis and Alzheimer's disease (AD), in which changes in the sphingolipid metabolism have been observed.

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Nonenveloped virus-like particles (VLPs) are self-assembled oligomeric structures composed of one or more proteins that originate from diverse viruses. Because these VLPs have similar antigenicity to the parental virus, they are successfully used as vaccines against cognate virus infection. Furthermore, after foreign antigenic sequences are inserted in their protein components (chimVLPs), some VLPs are also amenable to producing vaccines against pathogens other than the virus it originates from (these VLPs are named platform or epitope carrier).

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Background: Although sporadic Alzheimer's disease (AD) is a neurodegenerative disorder of unknown etiology, familial AD is associated with specific gene mutations. A commonality between these forms of AD is that both display multiple pathogenic events including cholinergic and lipid dysregulation.

Objective: We aimed to identify the relevant lipids and the activity of their related receptors in the frontal cortex and correlating them with cognition during the progression of AD.

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Multiple evidences suggest that mitochondrial dysfunction is implicated in the pathogenesis of Parkinson's disease via the selective cell death of dopaminergic neurons, such as that which occurs after prolonged exposure to the mitochondrial electron transport chain (ETC) complex I inhibitor, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyrine (MPTP). However, the effects of chronic MPTP on the ETC complexes and on enzymes of lipid metabolism have not yet been thoroughly determined. To face these questions, the enzymatic activities of ETC complexes and the lipidomic profile of MPTP-treated non-human primate samples were determined using cell membrane microarrays from different brain areas and tissues.

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Recent technical advances in mass spectrometry, as applied to the analytical chemistry of lipid molecules, enable the simultaneous detection of the multiplicity of lipid complex species present in the human brain. This, in combination with quantitative studies carried out in plasma samples, helps to identify disease biomarkers including for Alzheimer's disease (AD). Mass spectrometry imaging (MSI) is particularly powerful for the anatomical localization of lipids in brain slices, identifying lipid modifications in postmortem frozen samples from AD patients.

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Williams-Beuren syndrome (WBS) is a rare genetic multisystemic disorder characterized by mild-to-moderate intellectual disability and hypersocial phenotype, while the most life-threatening features are cardiovascular abnormalities. Nowadays, there are no pharmacological treatments to directly ameliorate the main traits of WBS. The endocannabinoid system (ECS), given its relevance for both cognitive and cardiovascular function, could be a potential druggable target in this syndrome.

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The endocannabinoid system modulates learning, memory, and neuroinflammatory processes, playing a key role in neurodegeneration, including Alzheimer's disease (AD). Previous results in a rat lesion model of AD showed modulation of endocannabinoid receptor activity in the basalo-cortical pathway following a specific lesion of basal forebrain cholinergic neurons (BFCNs), indicating that the glial neuroinflammatory response accompanying the lesion is related to endocannabinoid signaling. In this study, 7 days after the lesion, decreased astrocyte and increased microglia immunoreactivities (GFAP and Iba-1) were observed, indicating microglia-mediated neuroinflammation.

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Storage of aversive memories is of utmost importance for survival, allowing animals to avoid upcoming similar stimuli. However, without reinforcement, the learned avoidance response gradually decreases over time. Although the molecular mechanisms controlling this extinction process are not well known, there is evidence that the endocannabinoid system plays a key role through CB receptor-mediated modulation of cholinergic signaling.

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Alzheimer's disease (AD) is a progressive neurodegenerative disorder and the most common cause of dementia in aging populations. Recently, the regulation of neurolipid-mediated signaling and cerebral lipid species was shown in AD patients. The triple transgenic mouse model (3xTg-AD), harboring βAPP, PS1, and tau transgenes, mimics many critical aspects of AD neuropathology and progressively develops neuropathological markers.

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Alzheimer's disease (AD) represents the most common cause of dementia worldwide and has been consistently associated with the loss of basal forebrain cholinergic neurons (BFCNs) leading to impaired cholinergic neurotransmission, aberrant synaptic function, and altered structural lipid metabolism. In this sense, membrane phospholipids (PLs) can be used for de novo synthesis of choline (Ch) for the further obtaining of acetylcholine (ACh) when its availability is compromised. Specific lipid species involved in the metabolism of Ch have been identified as possible biomarkers of phenoconversion to AD.

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Background: Astrocytes provide a vital support to neurons in normal and pathological conditions. In Alzheimer's disease (AD) brains, reactive astrocytes have been found surrounding amyloid plaques, forming an astrocytic scar. However, their role and potential mechanisms whereby they affect neuroinflammation, amyloid pathology, and synaptic density in AD remain unclear.

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Several studies have demonstrated that lysophosphatidic acid (LPA) acts through its LPA receptors in multiple biological and behavioral processes, including adult hippocampal neurogenesis, hippocampal-dependent memory, and emotional regulation. However, analyses of the effects have typically involved acute treatments, and there is no information available regarding the effect of the chronic pharmacological modulation of the LPA/LPA receptors-signaling pathway. Thus, we analyzed the effect of the chronic (21 days) and continuous intracerebroventricular (ICV) infusion of C18:1 LPA and the LPA receptor antagonist Ki16425 in behavior and adult hippocampal neurogenesis.

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In the central nervous system, the inhibitory GABAB receptor is the archetype of heterodimeric G protein-coupled receptors (GPCRs). Receptor interaction with partner proteins has emerged as a novel mechanism to alter GPCR signaling in pathophysiological conditions. We propose here that GABAB activity is inhibited through the specific binding of fibulin-2, an extracellular matrix protein, to the B1a subunit in a rat model of neuropathic pain.

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The recent developments in mass spectrometry have revealed the importance of lipids as biomarkers in the context of different diseases and as indicators of the cell's homeostasis. However, further advances are required to unveil the complex relationships between lipid classes and lipid species with proteins. Here, we present a new methodology that combines microarrays with mass spectrometry to obtain the lipid fingerprint of samples of a different nature in a standardized and fast way, with minimal sample consumption.

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Neurolipids are a class of bioactive lipids that are produced locally through specific biosynthetic pathways in response to extracellular stimuli. Neurolipids are important endogenous regulators of neural cell proliferation, differentiation, oxidative stress, inflammation and apoptosis. Endocannabinoids (eCBs) and lysophosphatidic acid (LPA) are examples of this type of molecule and are involved in neuroprotection.

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α/β-Hydrolase domain-containing 6 (ABHD6) contributes to the hydrolysis of the major endocannabinoid 2-arachidonoylglycerol (2-AG) in the central nervous system (CNS) and in the periphery. ABHD6 blockade has been proposed as novel strategy to treat multiple sclerosis (MS), based on the observation that the inhibitor WWL70 exerts protective anti-inflammatory effects in experimental autoimmune encephalomyelitis (EAE). According to recent data, WWL70 exhibits off-target anti-inflammatory activity in microglial cells and the potential of ABHD6 as drug target in MS remains controversial.

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The endocannabinoid system, which modulates emotional learning and memory through CB1 receptors, has been found to be deregulated in Alzheimer's disease (AD). AD is characterized by a progressive decline in memory associated with selective impairment of cholinergic neurotransmission. The functional interplay of endocannabinoid and muscarinic signaling was analyzed in seven-month-old 3xTg-AD mice following the evaluation of learning and memory of an aversive stimulus.

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The basal forebrain cholinergic pathways progressively degenerate during the progression of Alzheimer's disease, leading to an irreversible impairment of memory and thinking skills. The stereotaxic lesion with 192IgG-saporin in the rat brain has been used to eliminate basal forebrain cholinergic neurons and is aimed at emulating the cognitive damage described in this disease in order to explore its effects on behavior and on neurotransmission. Learning and memory processes that are controlled by cholinergic neurotransmission are also modulated by the endocannabinoid (eCB) system.

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Neurochemical alterations in Alzheimer's disease (AD) include cholinergic neuronal loss in the nucleus basalis of Meynert (nbM) and a decrease in densities of the M2 muscarinic receptor subtype in areas related to learning and memory. Neuromodulators present in the cholinergic pathways, such as neuropeptides and neurolipids, control these cognitive processes and have become targets of research in order to understand and treat the pathophysiological and clinical stages of the disease. This is the case of the endocannabinoid and galaninergic systems, which have been found to be up-regulated in AD, and could therefore have a neuroprotective role.

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Lysophosphatidic acid (LPA) is a signaling molecule that binds to six known G protein-coupled receptors: LPA1 -LPA6 . LPA evokes several responses in the CNS, including cortical development and folding, growth of the axonal cone and its retraction process. Those cell processes involve survival, migration, adhesion proliferation, differentiation, and myelination.

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Autoradiography is used to determine the anatomical distribution of biological molecules in human tissue and experimental animal models. This method is based on the analysis of the specific binding of radiolabeled compounds to locate neurotransmitter receptors or transporters in fresh frozen tissue slices. The anatomical resolution obtained by quantification of the radioligands has allowed the density of receptor proteins to be mapped over the last 40 years.

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