Papers by Estibaliz Gonzalez de San Roman
European Polymer Journal, May 1, 2022
Methods in molecular biology, Nov 19, 2022
ACS Chemical Neuroscience, May 26, 2021
Alzheimer's disease (AD) represents the most common cause of dementia worldwide and has been ... more 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. Using a rat model of BFCN lesion, we have evaluated the lipid composition and muscarinic signaling in brain areas related to cognitive processes. The loss of BFCN resulted in alterations of varied lipid species related to Ch metabolism at nucleus basalis magnocellularis (NMB) and cortical projection areas. The activity of muscarinic receptors (mAChR) was decreased in the NMB and increased in the hippocampus according to the subcellular distribution of M1/M2 mAChR which could explain the learning and memory impairment reported in this AD rat model. These results suggest that the modulation of specific lipid metabolic routes could represent an alternative therapeutic strategy to potentiate cholinergic neurotransmission and preserve cell membrane integrity in AD.
Biochimica Et Biophysica Acta - Biomembranes, Sep 1, 2017
Alzheimer's disease (AD) is a progressive neurodegenerative disease affecting millions of patient... more Alzheimer's disease (AD) is a progressive neurodegenerative disease affecting millions of patients worldwide. Previous studies have demonstrated alterations in the lipid composition of lipid extracts from plasma and brain samples of AD patients. However, there is no consensus regarding the qualitative and quantitative changes of lipids in brains from AD patients. In addition, the recent developments in imaging mass spectrometry methods are leading to a new stage in the in situ analysis of lipid species in brain tissue slices from human postmortem samples. The present study uses the matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS), permitting the direct anatomical analysis of lipids in postmortem brain sections from AD patients, which are compared with the intensity of the lipid signal in samples from matched subjects with no neurological diseases. The frontal cortex samples from AD patients were classified in three groups based on Braak's histochemical criteria, ranging from non-cognitively impaired patients to those severely affected. The main results indicate a depletion of different sulfatide lipid species from the earliest stages of the disease in both white and gray matter areas of the frontal cortex. Therefore, the decrease in sulfatides in cortical areas could be considered as a marker of the disease, but may also indicate neurochemical modifications related to the pathogenesis of the disease. This article is part of a Special Issue entitled: Membrane Lipid Therapy: Drugs Targeting Biomembranes edited by Pablo Escríba-Ruíz.
ACS Macro Letters, Jul 5, 2023
A low cost and efficient method of doping pure zinc oxide powders for luminescence applications i... more A low cost and efficient method of doping pure zinc oxide powders for luminescence applications is presented. The powders have been obtained from pure, non-luminescent ZnO by thermally induced doping under a nitrogen flux and in the presence of ZnS powders. Structural characterization has been carried out by X-ray diffraction analysis (XRD), while luminescence properties have been studied with both a spectrofluorimeter and microraman spectrometer. Emission spectra have shown an increase of the luminescence with treatment temperature. The XRD patterns of all samples showed, along with reflections of the hexagonal phase of ZnO, other reflections ascribed to the hexagonal phase of ZnS. Upon further annealing in air at 800'C, the ZnS reflections disappear even though the luminescence still persists with a comparable intensity. Luminescence is ascribed to ZnO reduction due to the interaction of S with ZnO. It has also been observed that excitation with a He-Ne laser beam (X=633 nm) with a high specific power (5xl0-3 W.tm-2) yielded blue-green luminescence in spite of excitation below the band-to-band absorption threshold.
Polymer Chemistry, 2022
When applied to the cationic polymerization of styrene, thiocarbonylthio compounds can lead to a ... more When applied to the cationic polymerization of styrene, thiocarbonylthio compounds can lead to a dual control mechanism, where degenerative chain transfer occurs concurrent with a reversible addition mechanism.
Macromolecules, Nov 9, 2020
Macromolecular Materials and Engineering, Jun 16, 2021
Polymer Chemistry, 2019
Macrocyclic poly(ethylene oxide)s containing a protected thiol group are able to attach to gold s... more Macrocyclic poly(ethylene oxide)s containing a protected thiol group are able to attach to gold substrates without thiol deprotection enabling surface modification.
ChemistrySelect, 2020
3D monolithic integrated photocatlysts were prepared by self‐assembly of graphene platelets decor... more 3D monolithic integrated photocatlysts were prepared by self‐assembly of graphene platelets decorated with manganese doped TiO2 nanoparticles. The self‐assembly was induced by chemical reduction at mild reaction conditions. The physico‐chemical properties of the photocatalysts were improved by addition of polymer nanoparticles within the 3D structures. The rGO presence in the nanostructures affected their light absorption capability, which was red shifted. As a result, the band gap dropped from 3.12 eV in Mn doped TiO2 to 2.8 eV in the monolithic composite made of rGO and TiO2. The photocatalysts were applied for the elimination of methylene blue (MB) from aqueous solutions, the degradation of which was monitored by the Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry. It was shown that (i) MB was completely eliminated from aqueous solution; (ii) all the adsorbed MB was photocatalytically degraded under visible light, giving rise to various smaller molecu...
Macromolecular Chemistry and Physics, 2021
Taking advantage of the reversible Diels–Alder (DA) reaction, a simple strategy to obtain recycla... more Taking advantage of the reversible Diels–Alder (DA) reaction, a simple strategy to obtain recyclable epoxy resins is presented. For this purpose, blends of furan‐functionalized and nonfunctionalized epoxy resin are prepared. After the addition of diamine and bismaleimide, blends are heated at 150 °C for 5 min, where the permanent amine/epoxy reaction has taken place and upon cooling to room temperature the reversible DA reaction has happened, giving rise to a dual permanent/nonpermanent network. Both reactions are confirmed by Fourier‐transform infrared (FTIR) and13C‐crosspolarization, magic‐angle spinning (CP/MAS) nuclear magnetic resonance (NMR). Modulated differential scanning calorimetry (MDSC) shows that the epoxy/amine and bismaleimide/amine curing reaction take place, after the DA reaction, simultaneously with the retroDA reaction and before the bismaleimide homopolymerization. Therefore, under the appropriate curing conditions, the Michael's addition and the bismaleimide...
EKAIA Euskal Herriko Unibertsitateko Zientzia eta Teknologia Aldizkaria, 2020
Lipidoak funtzio energetikoa eta egitura-funtzioez gain, deskribatu diren beste funtzioei esker g... more Lipidoak funtzio energetikoa eta egitura-funtzioez gain, deskribatu diren beste funtzioei esker garrantzitsuak bilakatzen ari dira. Funtzio neurotransmisorea edota neuromoduladorea aurkeztu duten lipidoen artean, lisofosfolipidoak aurki ditzakegu. Lisofosfolipidoak lipido molekula txiki bioaktiboak, karbonodun katea bakarra eta buru polar bat edukitzeagatik bereizten direnak dira. Lisofosfolipidoen artean, azido lisofosfatidikoa eta esfingosina 1-fosfatoaren egitura eta sistemen funtzioak hobeto deskribatu direnak izan dira. Lisofosfolipidoak zelulaz kanpoko bitartekari bezala aritzen dira beraientzako espezifikoak diren G proteinei loturiko hartzaileak aktibatuz. Molekula hauen seinaleztapenaren bidez zenbait prozesu neurokimiko modulatzen dira, adibidez, neuromodulazioa eta neuroinflamazioa. Gainera, ikasketarekin eta oroimenarekin erlazioa aurkeztu dute. Honen harian, orain arte hoberen deskribatutako lisofosfolipidoen sistemak, azido lisofosfatidikoa eta esfingosina 1-fosfatoa, ...
RSC Advances, 2020
Fenton reaction nanocatalysts made of reduced graphene oxide–magnetic nanoparticle 3D composite a... more Fenton reaction nanocatalysts made of reduced graphene oxide–magnetic nanoparticle 3D composite aerogels for the elimination of organic dyes from aqueous solution.
Frontiers in Molecular Neuroscience, 2019
Neurolipids are a class of bioactive lipids that are produced locally through specific biosynthet... more 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. The present study analyzes a possible relationship of the main receptor subtypes for both neurolipid systems that are present in the central nervous system, the CB 1 and LPA 1 receptors, by using brain slices from CB 1 KO mice and LPA 1-null mice. Receptor-mediated G protein activation and glycerophospholipid regulation of potential precursors of their endogenous neurotransmitters were measured by two different in vitro imaging techniques, functional autoradiography and imaging mass spectrometry (IMS), respectively. Possible crosstalk between CB 1 and LPA 1 receptors was identified in specific areas of the brain, such as the amygdala, where LPA 1 receptor activity is upregulated in CB 1 KO mice. More evidence of an interaction between both systems was that the CB 1-mediated activity was clearly increased in the prefrontal cortex and cerebellum of LPA 1-null mice. The eCB system was specifically over-activated in regions where LPA 1 has an important signaling role during embryonic development. The modifications on phospholipids (PLs) observed in these genetically modified mice by using the IMS technique indicated the regulation of some of the PL precursors of both LPA and eCBs in specific brain areas. For example, phosphatidylcholine (PC) (36:1) was detected as a potential LPA precursor, and phosphatidylethanolamine (PE) (40:6) and PE (p18:0/22:6) as potential eCB precursors. The absence of the main cerebral receptors for LPA or eCB systems is able to induce modulation on the other at the levels of both signaling and synthesis of endogenous neurotransmitters, indicating adaptive responses between both systems during prenatal and/or postnatal development.
Biochimica et Biophysica Acta (BBA) - Biomembranes, 2017
Lipids not only constitute the primary component of cellular membranes and contribute to metaboli... more Lipids not only constitute the primary component of cellular membranes and contribute to metabolism but also serve as intracellular signaling molecules and bind to specific membrane receptors to control cell proliferation, growth and convey neuroprotection. Over the last several decades, the development of new analytical techniques, such as imaging mass spectrometry (IMS), has contributed to our understanding of their involvement in physiological and pathological conditions. IMS allows researchers to obtain a wide range of information about the spatial distribution and abundance of the different lipid molecules that is crucial to understand brain functions.
Brain Structure & Function, Apr 10, 2018
The primary visual cortex (area V1) is an extensively studied part of the cerebral cortex with we... more The primary visual cortex (area V1) is an extensively studied part of the cerebral cortex with well-characterized connectivity, cellular and molecular architecture and functions (for recent reviews see Amunts and Zilles, Neuron 88:1086-1107, 2015; Casagrande and Xu, Parallel visual pathways: a comparative perspective. The visual neurosciences, MIT Press, Cambridge, pp 494-506, 2004). In humans, V1 is defined by heavily myelinated fibers arriving from the radiatio optica that form the Gennari stripe in cortical layer IV, which is further subdivided into laminae IVa, IVb, IVcα and IVcβ. Due to this unique laminar pattern, V1 represents an excellent region to test whether multimodal mass spectrometric imaging could reveal novel biomolecular markers for a functionally relevant parcellation of the human cerebral cortex. Here we analyzed histological sections of three post-mortem brains with matrix-assisted laser desorption/ionization mass spectrometry imaging and laser ablation inductively coupled plasma mass spectrometry imaging to investigate the distribution of lipids, proteins and metals in human V1. We identified 71 peptides of 13 different proteins by in situ tandem mass spectrometry, of which 5 proteins show a differential laminar distribution pattern revealing the border between V1 and V2. High-accuracy mass measurements identified 123 lipid species, including glycerolipids, glycerophospholipids and sphingolipids, of which at least 20 showed differential distribution within V1 and V2. Specific lipids labeled not only myelinated layer IVb, but also IVa and especially IVc in a layer-specific manner, but also and clearly separated V1 from V2. Elemental imaging further showed a specific accumulation of copper in layer IV. In conclusion, multimodal mass spectrometry imaging identified novel biomolecular and elemental markers with specific laminar and inter-areal differences. We conclude that mass spectrometry imaging provides a promising new approach toward multimodal, molecule-based cortical parcellation. Keywords Human brain • Peptides • Lipids • Elements • Mass spectrometry imaging • Primary visual cortex • MALDI mass spectrometry imaging • Laser ablation inductively coupled plasma mass spectrometry imaging Abbreviations V1 Primary visual cortex V2 Secondary visual cortex MALDI-MSI Matrix-assisted laser desorption/ionization mass spectrometry imaging Estibaliz González de San Román and Hans-Jürgen Bidmon contributed equally to the study.
International Journal of Molecular Sciences, 2021
Alzheimer’s disease (AD) is a progressive neurodegenerative disorder and the most common cause of... more 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 βAPPSwe, PS1M146V, and tauP301L transgenes, mimics many critical aspects of AD neuropathology and progressively develops neuropathological markers. Thus, in the present study, 3xTg-AD mice have been used to test the involvement of the neurolipid-based signaling by endocannabinoids (eCB), lysophosphatidic acid (LPA), and sphingosine 1-phosphate (S1P) in relation to the lipid deregulation. [35S]GTPγS autoradiography was used in the presence of specific agonists WIN55,212-2, LPA and CYM5442, to measure the activity mediated by CB1, LPA1, and S1P1 Gi/0 coupled receptors, respectively. Consecutive slides were used to analyze the relative intensities of multiple lipid species by MALDI Mass spectrome...
Macromolecular Reaction Engineering, 2021
Scientific Reports, 2021
Composite Fenton nanocatalyst was prepared by water-based in situ creation of Fe3O4 nanoparticles... more Composite Fenton nanocatalyst was prepared by water-based in situ creation of Fe3O4 nanoparticles integrated within the self-assembly 3D reduced graphene oxide (rGO) aerogel. The hybrid applied for the degradation of Acid Green 25 (AG-25) organic dye in an aqueous solution, in the presence of H2O2. By investigating the conditions that maximize the dye adsorption by the 3D composite, it was found that the pH of the solution should be adjusted between the pKa of the functional groups present on the rGO surface (carboxylic acid) and that of the dye (sulfonic acid) to promote electrostatic interactions dye—3D structure. Performed under these conditions, Fenton degradation of AG-25 in presence of H2O2 was completed in less than 30 min, including all the intermediate products, as demonstrated by MALDI–TOF–MS analysis of the aqueous solution after discoloration. Moreover, this was achieved in a solution with as high a dye concentration of 0.5 mg/mL, with only 10 mg of 3D composite catalyst...
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Papers by Estibaliz Gonzalez de San Roman