Person: García Álvarez, Isabel
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First Name
Isabel
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García Álvarez
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Ciencias Experimentales
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Item Neurotransmitter-Responsive Nanosensors for T2‑Weighted Magnetic Resonance Imaging.(Journal of the American Chemical Society, 2019) Hsieh, Vivian; Okada, Satoshi; We, He; García Álvarez, Isabel; Barandov, Ali; Recuenco Alvarado, Santiago; Ohlendorf, Robert; Fan, Jingxuan; Ortega, Athena; Jasanoff, AlanNeurotransmitter-sensitive contrast agents for magnetic resonance imaging (MRI) have recently been used for mapping signaling dynamics in live animal brains, but paramagnetic sensors for T1-weighted MRI are usually effective only at micromolar concentrations that themselves perturb neurochemistry. Here we present an alternative molecular architecture for detecting neurotransmitters, using superparamagnetic iron oxide nanoparticles conjugated to tethered neurotransmitter analogs and engineered neurotransmitter binding proteins. Interactions between the nanoparticle conjugates result in clustering that is reversibly disrupted in the presence of neurotransmitter analytes, thus altering T2-weighted MRI signals. We demonstrate this principle using tethered dopamine and serotonin analogs, together with proteins selected for their ability to competitively bind either the analogs or the neurotransmitters themselves. Corresponding sensors for dopamine and serotonin exhibit target-selective relaxivity changes of up to 20%, while also operating below endogenous neurotransmitter concentrations. Semisynthetic magnetic particle sensors thus represent a promising path for minimally perturbative studies of neurochemical analytes.Item Evaluation of Anti-Neuroinflammatory Activity of Isatin Derivatives in Activated Microglia.(Molecules, 2023) Cenalmor Molina, Alejandro; Pascual, Elena; Gil-Manso, Sergio; Correa-Rocha, Rafael; Suárez, José Ramón; García Álvarez, IsabelNeuroinflammation plays a crucial role in the progression of Alzheimer’s disease and other neurodegenerative disorders. Overactivated microglia cause neurotoxicity and prolong the inflammatory response in many neuropathologies. In this study, we have synthesised a series of isatin derivatives to evaluate their anti-neuroinflammatory potential using lipopolysaccharide activated microglia as a cell model. We explored four different substitutions of the isatin moiety by testing their anti-neuroinflammatory activity on BV2 microglia cells. Based on the low cytotoxicity and the activity in reducing the release of nitric oxide, pro-inflammatory interleukin 6 and tumour necrosis factor α by microglial cells, the N1-alkylated compound 10 and the chlorinated 20 showed the best results at 25 µM. Taken together, the data suggest that 10 and 20 are promising lead compounds for developing new neuroprotective agents.Item Functional Heterogeneity of Mouse and Human Brain OPCs: Relevance for Preclinical Studies in Multiple Sclerosis.(Journal of Clinical Medicine, 2020) Bribián, Ana; Medina Rodríguez, Eva M.; Josa Prado, Fernando; García Álvarez, Isabel; Machín Díaz, Isabel; Esteban, Pedro F.; Murcia Belmonte, Verónica; Vega Zelaya, Lorena; Pastor, Jesús; Garrido, Leoncio; De Castro, FernandoBesides giving rise to oligodendrocytes (the only myelin-forming cell in the Central Nervous System (CNS) in physiological conditions), Oligodendrocyte Precursor Cells (OPCs) are responsible for spontaneous remyelination after a demyelinating lesion. They are present along the mouse and human CNS, both during development and in adulthood, yet how OPC physiological behavior is modified throughout life is not fully understood. The activity of adult human OPCs is still particularly unexplored. Significantly, most of the molecules involved in OPC-mediated remyelination are also involved in their development, a phenomenon that may be clinically relevant. In the present article, we have compared the intrinsic properties of OPCs isolated from the cerebral cortex of neonatal, postnatal and adult mice, as well as those recovered from neurosurgical adult human cerebral cortex tissue. By analyzing intact OPCs for the first time with 1H High Resolution Magic Angle Spinning Nuclear Magnetic Resonance (1H HR-MAS NMR) spectroscopy, we show that these cells behave distinctly and that they have different metabolic patterns in function for their stage of maturity. Moreover, their response to Fibroblast Growth Gactor-2 (FGF-2) and anosmin-1 (two molecules that have known effects on OPC biology during development and that are overexpressed in individuals with Multiple Sclerosis (MS)) differs in relation to their developmental stage and in the function of the species. Our data reveal that the behavior of adult human and mouse OPCs differs in a very dynamic way that should be very relevant when testing drugs and for the proper design of effective pharmacological and/or cell therapies for MS.Item Micellar Iron Oxide Nanoparticles Coated with Anti-Tumor Glycosides.(Nanomayerials, 2018) Groult, Hugo; García Álvarez, Isabel; Romero Ramírez, Lorenzo; Nieto Sampedro, Manuel; Herranz, Fernando; Fernández Mayoralas, Alfonso; Ruiz Cabello, JesúsThe synthesis procedure of nanoparticles based on thermal degradation produces organic solvent dispersible iron oxide nanoparticles (OA-IONP) with oleic acid coating and unique physicochemical properties of the core. Some glycosides with hydrophilic sugar moieties bound to oleyl hydrophobic chains have antimitotic activity on cancer cells but reduced in vivo applications because of the intrinsic low solubility in physiological media, and are prone to enzymatic hydrolysis. In this manuscript, we have synthetized and characterized OA-IONP-based micelles encapsulated within amphiphilic bioactive glycosides. The glycoside-coated IONP micelles were tested as Magnetic Resonance Imaging (MRI) contrast agents as well as antimitotics on rat glioma (C6) and human lung carcinoma (A549) cell lines. Micelle antimitotic activity was compared with the activity of the corresponding free glycosides. In general, all OA-IONP-based micellar formulations of these glycosides maintained their anti-tumor effects, and, in one case, showed an unusual therapeutic improvement. Finally, the micelles presented optimal relaxometric properties for their use as T2-weighed MRI contrast agents. Our results suggest that these bioactive hydrophilic nano-formulations are theranostic agents with synergistic properties obtained from two entities, which separately are not ready for in vivo applications, and strengthen the possibility of using biomolecules as both a coating for OA-IONP micellar stabilization and as drugs for therapy.