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Alzheimer's disease (AD), the most common type of dementia, currently represents an extremely challenging and unmet medical need worldwide. Amyloid-β (Aβ) and Tau proteins are prototypical AD hallmarks, as well as validated drug targets. Accumulating evidence now suggests that they synergistically contribute to disease pathogenesis. This could not only help explain negative results from anti-Aβ clinical trials but also indicate that therapies solely directed at one of them may have to be reconsidered. Based on this, herein, we describe the development of a focused library of 2,4-thiazolidinedione (TZD)-based bivalent derivatives as dual Aβ and Tau aggregation inhibitors. The aggregating activity of the 24 synthesized derivatives was tested in intact Escherichia coli cells overexpressing Aβ42 and Tau proteins. We then evaluated their neuronal toxicity and ability to cross the blood-brain barrier (BBB), together with the in vitro interaction with the two isolated proteins. Finally, the most promising (most active, nontoxic, and BBB-permeable) compounds 22 and 23 were tested in vivo, in a Drosophila melanogaster model of AD. The carbazole derivative 22 (20 μM) showed extremely encouraging results, being able to improve both the lifespan and the climbing abilities of Aβ42 expressing flies and generating a better outcome than doxycycline (50 μM). Moreover, 22 proved to be able to decrease Aβ42 aggregates in the brains of the flies. We conclude that bivalent small molecules based on 22 deserve further attention as hits for dual Aβ/Tau aggregation inhibition in AD., This work was conducted by A.E.G during a scholarship at the University of Bologna, Italy, supported by the International Cooperation Program CAPES/ PDSE Process #88881.187586/ 2018-01. O.S. acknowledges the Ministry of Education, Youth and Sports of the Czech Republic (project ERDF no. CZ.02.1.01/0.0/0.0/18_069/0010054). DMT: grant PID2020-118127RB-I00 funded by MCIN/AEI/10.13039/501100011033. M.L.B. and M.B. would also like to acknowledge the University of Bologna (RFO 2019) and the Italian Ministry of Education, Universities and Research (MIUR), for financial support.

Early diagnosis of Alzheimer's disease and its prodromal stage, also known as mild cognitive impairment (MCI), is critical since some patients with progressive MCI will develop the disease. We propose a multi-stream deep convolutional neural network fed with patch-based imaging data to classify stable MCI and progressive MCI. First, we compare MRI images of Alzheimer's disease with cognitively normal subjects to identify distinct anatomical landmarks using a multivariate statistical test. These landmarks are then used to extract patches that are fed into the proposed multi-stream convolutional neural network to classify MRI images. Next, we train the architecture in a separate scenario using samples from Alzheimer's disease images, which are anatomically similar to the progressive MCI ones and cognitively normal images to compensate for the lack of progressive MCI training data. Finally, we transfer the trained model weights to the proposed architecture in order to fine-tune the model using progressive MCI and stable MCI data. Experimental results on the ADNI-1 dataset indicate that our method outperforms existing methods for MCI classification, with an F1-score of 85.96%.

Background: Museums and cultural institutions are increasingly aware of both the interests and needs of society. Accordingly, these institutions are becoming allies in terms of health and well-being due to the importance of their social functions. Presently, many institutions create cultural activities aimed at cognitively impaired people, a group on the rise owing to the prevalence of dementia and the aging of society. Nevertheless, scientific evidence in this field remains scarce. As a result, the main objective of this research was to empirically evaluate and identify the benefits that cultural interventions can bring to cognitively impaired participants. Method: A meta-analysis (MA) was performed following PRISMA guidelines. When inclusion and eligibility criteria had been established, articles were subsequently selected through a strategic search of Web of Science, SCOPUS, PubMed, and Medline. Results: Twenty-six studies met the eligibility criteria, involving a total of 1201 participants with cognitive impairment. The results showed a statistically non-significant effect size when analyzing these cultural interventions for cognitively impaired people overall. However, when conducting partial meta-analyses (MA'), focusing on studies related to a specific disease, a particular type of treatment, or a specific type of evaluation, the results concurred with the conclusion of the previous systematic review (SR). Conclusion: Despite the high heterogeneity of the studies, benefits were identified in emotional well-being and social aspects but not in clinical ones such as the deterioration of cognitive or motor function, among others.

Treballs Finals de Grau d'Enginyeria Biomèdica. Facultat de Medicina i Ciències de la Salut. Universitat de Barcelona. Curs: 2022-2023. Tutor/Director: Roca-Cusachs Soulere, Pere, De la Cruz, Jorge Oliver, Neurodegenerative disorders, including Alzheimer’s disease, pose a global social burden strongly linked with aging populations. Despite extensive research efforts, the underlying causes of the neuropathological changes that result in neuronal death are unknown, making the improvement of in vitro models a priority to address. Moreover, these pathological events are accompanied by alterations in brain rigidity, and while it is well established how various cell types can feel these mechanical cues and adapt their function, neuronal mechanosensing remains mostly unexplored. For this reason, in this project we aimed to investigate the mechanobiology of Alzheimer's disease by optimizing the differentiation of SH-SY5Y cells into pseudo-neurons. To facilitate neuronal differentiation, we adopted a novel strategy in which, by introducing a genetic construct in the SH-SY5Y cells, we could control the expression of the neuronal master gene NGN2. We demonstrated that this system, along with an optimized differentiation protocol, led to the production of more mature neuron-like cells. Subsequently, the response of differentiated cells to mechanical stimulation was tested by culturing them in polyacrylamide gels with varying stiffness. Immunostaining and image analysis confirmed the morphological adaptation of neuron-like cells to matrix stiffness, presenting better morphology at a higher stiffness. Finally, we observed detectable levels of the co-transcriptional factor YAP and confirmed that its nuclear presence is mechanoregulated in neurons. In conclusion, by combining differentiation techniques, genetic modification, and mechanical stimulation, our study provides a new model to explore Alzheimer's disease mechanobiology, potentially leading to innovative therapeutic strategies by uncovering complex underlying mechanisms.

Brain corpora amylacea, recently renamed as wasteosomes, are polyglucosan bodies that appear during aging and some neurodegenerative conditions. They collect waste substances and are part of a brain cleaning mechanism. For decades, studies on their composition have produced inconsistent results and the presence of tau protein in them has been controversial. In this work, we reanalyzed the presence of this protein in wasteosomes and we pointed out a methodological problem when immunolabeling. It is well known that to detect tau it is necessary to perform an antigen retrieval. However, in the case of wasteosomes, an excessive antigen retrieval with boiling dissolves their polyglucosan structure, releases the entrapped proteins and, thus, prevents their detection. After performing an adequate pre-treatment, with an intermediate time of boiling, we observed that some brain wasteosomes from patients with Alzheimer’s disease (AD) contained tau, while we did not detect tau protein in those from non-AD patients. These observations pointed the different composition of wasteosomes depending on the neuropathological condition and reinforce the role of wasteosomes as waste containers.

Background Smell impairment is one of the earliest features in Alzheimer’s (AD) and Parkinson’s diseases (PD). Due to sex diferences exist in terms of smell and olfactory structures as well as in the prevalence and manifestation of both neurological syndromes, we have applied olfactory proteomics to favor the discovery of novel sex-biased physio-pathological mechanisms and potential therapeutic targets associated with olfactory dysfunction. Methods SWATH-MS (sequential window acquisition of all theoretical fragment ion spectra mass spectrometry) and bioinformatic workfows were applied in 57 post-mortem olfactory tracts (OT) derived from controls with no known neurological history (n=6F/11M), AD (n=4F/13M) and PD (n=7F/16M) subjects. Complementary molecular analyses by Western-blotting were performed in the olfactory bulb (OB), entorhinal cortex (EC) and amygdala areas. Results 327 and 151 OT diferentially expressed proteins (DEPs) were observed in AD women and AD men, respec‑ tively (35 DEPs in common). With respect to PD, 198 DEPs were identifed in PD women, whereas 95 DEPs were detected in PD men (20 DEPs in common). This proteome dyshomeostasis induced a disruption in OT protein interac‑ tion networks and widespread sex-dependent pathway perturbations in a disease-specifc manner, among them Sirtuin (SIRT) signaling. SIRT1, SIRT2, SIRT3 and SIRT5 protein levels unveiled a tangled expression profle across the olfactory–entorhinal–amygdaloid axis, evidencing disease-, sex- and brain structure-dependent changes in olfactory protein acetylation. Conclusions Alteration in the OT proteostasis was more severe in AD than in PD. Moreover, protein expression changes were more abundant in women than men independent of the neurological syndrome. Mechanistically, the tangled SIRT profle observed across the olfactory pathway-associated brain regions in AD and PD indicates difer‑ ential NAD (+)-dependent deacetylase mechanisms between women and men. All these data shed new light on diferential olfactory mechanisms across AD and PD, pointing out that the evaluation of the feasibility of emerging sirtuin-based therapies against neurodegenerative diseases should be considered with caution, including further sex dimension analyses in vivo and in clinical studies. The Proteomics Platform of Navarrabiomed was member of Proteored (PRB3-ISCIII) supported by grant PT17/0019/009, of the PE I+D+I 2013–2016 funded by ISCIII and FEDER. The Clinical Neuroproteomics Unit of Navarrabiomed is member of the Global Consortium for Chemosensory Research (GCCR) and the Spanish Olfactory Network (ROE) (supported by grant RED2018-102662-T funded by Spanish Ministry of Science and Innovation). This work was funded by grants from the Spanish Ministry of Science, Innovation and Universities (Ref. PID2019-110356RB-I00/AEI/10.13039/501100011033). to J.F.-I. and E.S.) and the Department of Economic and Business Development from Government of Navarra (Ref. 0011-1411-2020-000028 to E.S.). PC-C was supported by a predoctoral fellowship from the Public University of Navarra (UPNA).

One of the richest tissues in lipid content and diversity of the human body is the brain. The human brain is constitutively highly vulnerable to oxidative stress. This oxidative stress is a determinant in brain aging, as well as in the onset and progression of sporadic (late-onset) Alzheimer’s disease (sAD). Glycerophospholipids are the main lipid category widely distributed in neural cell membranes, with a very significant presence for the ether lipid subclass. Ether lipids have played a key role in the evolution of the human brain compositional specificity and functionality. Ether lipids determine the neural membrane structural and functional properties, membrane trafficking, cell signaling and antioxidant defense mechanisms. Here, we explore the idea that ether lipids actively participate in the pathogenesis of sAD. Firstly, we evaluate the quantitative relevance of ether lipids in the human brain composition, as well as their role in the human brain evolution. Then, we analyze the implications of ether lipids in neural cell physiology, highlighting their inherent antioxidant properties. Finally, we discuss changes in ether lipid content associated with sAD and their physiopathological implications, and propose a mechanism that, as a vicious cycle, explains the potential significance of ether lipids in sAD.

Alzheimer’s disease (AD) is a progressive neurodegenerative brain disease. Thus, drugs including donepezil, rivastigmine, and galantamine are not entirely effective in the treatment of this multifactorial disease. The present study evaluates eight derivatives (3a–3h) as candidates with stronger anti-AD potential but with less side effects. Reactive oxygen species (ROS) assays were used to assess oxidative stress which involve in the neurodegeneration. The neuroprotective properties of 3e against oxidative stress were done in three experiments using MTT test. The anti-AD potential was determined based on their anticholinesterase inhibition ability, determined using Ellman’s method, Aβ aggregation potential according to thioflavin (Th) fluorescence assay, and their antioxidative and anti-inflammatory activities. Compound 3e exhibited moderate cholinesterase inhibition activity (AChE, IC50 = 0.131 µM; BuChE, IC50 = 0.116 µM; SI = 1.13), significant inhibition of Aβ(1–42) aggregation (55.7%, at 5 µM) and acceptable neuroprotective activity. Extensive analysis of in vitro and in vivo assays indicates that new cyclopentaquinoline derivatives offer promise as candidates for new anti-AD drugs.

Alzheimer's disease (AD) is characterized by a polyetiological origin. Despite the global burden of AD and the advances made in AD drug research and development, the cure of the disease remains elusive, since any developed drug has demonstrated effectiveness to cure AD. Strikingly, an increasing number of studies indicate a linkage between AD and type 2 diabetes mellitus (T2DM), as both diseases share some common pathophysiological features. In fact, β-secretase (BACE1) and acetylcholinesterase (AChE), two enzymes involved in both conditions, have been considered promising targets for both pathologies. In this regard, due to the multifactorial origin of these diseases, current research efforts are focusing on the development of multi-target drugs as a very promising option to derive effective treatments for both conditions. In the present study, we evaluated the effect of rhein-huprine hybrid (RHE-HUP), a synthesized BACE1 and AChE inhibitor, both considered key factors not only in AD but also in metabolic pathologies. Thus, the aim of this study is to evaluate the effects of this compound in APP/PS1 female mice, a well-established familial AD mouse model, challenged by high-fat diet (HFD) consumption to concomitantly simulate a T2DM-like condition., This work was supported by the Spanish Ministry of Science and Innovation (SAF2017-84283-R, PID2020-118127RB-I00, PID2021-122473OA-I00, PID2021-122187NB-C32, PID2021-123462OB-I00), the Fondo de Investigación Sanitaria (PI19/00854) and co founded by the Fondo Europeo de Desarrollo Regional (FEDER), theCentre for Network Biomedical Research on Neurodegenerative Diseases CB06/05/0024) and the Generalitat de Catalunya (2014SGR‑525). This research was partially funded by PRIME/H2020-SC1-BHC-2018–2020, Ref: 847879) and Programa Estatal de Fomento de la investigación Científica y Técnica de Excelencia Maria de Maeztu (CEX2021-001159-M), Universidad de Barcelona, UBNEURO Instituto de neurociencias. AC is a recipient of the Instituto de Salud Calos III Sara Borrell fellowship (grant CD22/00125). ESL is supported by the Requalification of the Spanish University System Program. JO and ME are Serra Húnter fellows.

Alzheimer's disease (AD) is a neurodegenerative condition affecting millions worldwide, characterized by cognitive decline and dementia. The rising incidence of the disease and the lack of effective current treatments point to the need for alternative therapeutic strategies. Gut microbiota has emerged as a promising research avenue due to its association with AD pathology. Caloric restriction (CR), a dietary intervention involving controlled calorie reduction, has shown promising effects in extending lifespan and modulating gut microbiota.

La síndrome de Down (SD) és la causa més freqüent de discapacitat intel·lectual (DI) d'origen genètic i està causada per la triplicació del cromosoma 21. Alguns dels gens codificats en aquest cromosoma, principalment el de la proteïna precursora de l'amiloide (APP), fan que aquestes persones presentin les marques fisiopatològics de la malaltia d'Alzheimer (MA) a partir dels 40 anys i que, per tant, tinguin un elevadíssim risc de desenvolupar una demència per MA. No obstant, el diagnòstic clínic de la demència en aquesta població és un repte degut a la DI premòrbida associada a la pròpia SD, a la manca de criteris diagnòstics adaptats, i a la manca de dades normatives dels tests neuropsicològics. Actualment no hi ha tractaments per prevenir o curar la MA i, a més, les persones amb SD han estat històricament excloses dels assaigs clínics i la recerca, negant-los l'oportunitat de beneficiar-se de possibles tractaments i avenços científics. L'objectiu d'aquesta tesi doctoral es centra en la caracterització del curs clínic i cognitiu de la MA en aquesta població i en l'estudi del rendiment diagnòstic i pronòstic de diferents biomarcadors de fluids en plasma i líquid cefaloraquidi (LCR). Per fer-ho, ens hem basat en dades de la cohort més gran d'arreu del món d'adults amb la SD per l'estudi de la MA, la cohort Down Alzheimer Barcelona Neuroimaging Initiative (DABNI). Concretament, descrivim com entre la població adulta amb la SD és quasi inevitable la progressió cap a la fase de demència de la MA a mida que envelleixen i, especialment, a partir de la quinta dècada de vida. Així, posem de manifest la urgent necessitat de dissenyar plans de salut i assaigs clínics específics contra la MA per aquesta població. D'aquesta manera, serà imprescindible validar eines neuropsicològiques i definir uns criteris diagnòstics adaptats a persones amb la SD. En contra del que s'ha assumit fins al moment en el camp de la DI, i de la síndrome de Down en particular, en la present tesi demostrem que és factible avaluar el deteriorament cognitiu de la MA es pot diagnosticar amb una avaluació transversal. A més, mostrem la viabilitat de monitoritzar el rendiment cognitiu de les persones amb la SD al llarg d'un assaig clínic preventiu validant dues eines neuropsicològiques com a variables d'eficàcia (endpoints) cognitives, imprescindibles en qualsevol assaig clínic per la MA. Finalment, en un context on els biomarcadors han revolucionat la manera de diagnosticar la MA en la població general, destaquem la necessitat d'adaptar aquests avenços per aplicar-los a la població amb la SD. En aquest sentit, hem validat el rendiment diagnòstic i pronòstic dels neurofilaments de cadena lleugera (NfL) en plasma per la detecció de la MA en la SD i hem explorat un panell de proteïnes sinàptiques en líquid cefaloraquidi (LCR) com a possibles biomarcadors de la MA que podrien ser útils per monitoritzar la resposta terapèutica assaigs clínics. En resum, les dades presentades en aquesta tesi doctoral s'han centrat en el diagnòstic de les fases simptomàtiques de la MA i en l'estudi dels canvis clínics, cognitius i de biomarcadors de la malaltia en adults amb la SD. Estudis multimodals com els presentats en aquesta recull són essencials per avançar en el coneixement de la història natural de la MA, per desenvolupar noves eines diagnòstiques precises i, potencialment, per descobrir noves dianes terapèutiques. El síndrome de Down (SD) es la causa más frecuente de discapacidad intelectual (DI) de origen genético y está causada por la triplicación del cromosoma 21. Algunos de los genes codificados en este cromosoma, principalmente el de la proteína precursora del amiloide (APP), son los responsables de que estas personas presenten las marcas fisiopatológicos de la enfermedad de Alzheimer (EA) a partir de los 40 años y que, por tanto, tengan un elevadísimo riesgo de desarrollar una demencia por EA. Sin embargo, el diagnóstico clínico de la demencia en esta población es un reto debido a la DI premórbida asociada al propio SD, a la falta de criterios diagnósticos adaptados y a la falta de datos normativos de los test neuropsicológicos. Actualmente no existen tratamientos para prevenir o curar la EA y, además, las personas con SD han sido históricamente excluidas de los ensayos clínicos y la investigación, negándoles la oportunidad de beneficiarse de posibles tratamientos y de los avances científicos. El objetivo de esta tesis doctoral se centra en la caracterización del curso clínico y cognitivo de la EA en esta población y en el estudio del rendimiento diagnóstico y pronóstico de diferentes biomarcadores de fluidos en plasma y líquido cefalorraquídeo (LCR). Para ello, nos hemos basado en datos de la mayor cohorte del mundo de adultos con SD para el estudio de la EA, la cohorte Down Alzheimer Barcelona Neuroimaging Initiative (DABNI). Concretamente, describimos cómo entre la población adulta con SD es casi inevitable la progresión hacia la fase de demencia de la EA a medida que envejecen y, especialmente, a partir de la quinta década de vida. Así, ponemos de manifiesto la urgente necesidad de diseñar planes de salud y ensayos clínicos específicos contra la EA para esta población. De esta forma, será imprescindible validar herramientas neuropsicológicas y definir unos criterios diagnósticos adaptados a personas con SD. En contra de lo asumido hasta el momento en el campo de la DI, y del síndrome de Down en particular, en la presente tesis demostramos que es factible evaluar el deterioro cognitivo asociado a la EA con una evaluación transversal. Además, mostramos la viabilidad de monitorizar el rendimiento cognitivo de las personas con SD a lo largo de un ensayo clínico preventivo, validando dos herramientas neuropsicológicas como variables de eficacia (endpoints) cognitivas, imprescindibles en cualquier ensayo clínico para la EA. Por último, en un contexto en el que los biomarcadores han revolucionado la manera de diagnosticar la EA en la población general, destacamos la necesidad de adaptar estos avances para aplicarlos a la población con SD. En este sentido, hemos validado el rendimiento diagnóstico y pronóstico de los neurofilamentos de cadena ligera (NfL) en plasma para la detección de la EA en el SD y hemos explorado un panel de proteínas sinápticas en líquido cefalorraquídeo (LCR) como posibles biomarcadores de la EA que podrían ser útiles para monitorizar la respuesta terapéutica en ensayos clínicos. En resumen, los datos presentados en esta tesis doctoral se han centrado en el diagnóstico de las fases sintomáticas de la EA y en el estudio de los cambios clínicos, cognitivos y de biomarcadores de la enfermedad en adultos con SD. Estudios multimodales como los presentados en este compendio son esenciales para avanzar en el conocimiento de la historia natural de la EA, para desarrollar nuevas herramientas diagnósticas precisas y, potencialmente, para descubrir nuevas dianas terapéuticas. Down syndrome (DS) is the most common cause of intellectual disability (ID) of genetic origin, and it is caused by the triplication of the chromosome 21. Some genes coded in this chromosome such as the amyloid precursor protein (APP), lead to the universal presence of Alzheimer's disease (AD) pathological hallmarks in adults with DS by the age of 40, and, subsequently, to an ultra-high risk to develop AD dementia. However, the clinical diagnosis of dementia in individuals with DS is a challenge due to the associated neurodevelopmental ID, and the lack of validated clinical criteria and neuropsychological normative data to diagnose symptomatic AD. Currently, there are no treatments to prevent or stop AD in this population, and adults with DS have historically been excluded from AD clinical trials and research denying them the opportunity to benefit from potential treatments and scientific breakthroughs. This doctoral thesis aimed to better characterize the clinical and cognitive course of AD in this population, and to study the performance of different fluid biomarkers in plasma and cerebrospinal fluid (CSF). Our data is based on the Down Alzheimer Barcelona Neuroimaging Initiative (DABNI) cohort of adults with DS, the largest cohort for the study of AD in DS worldwide. Our works have shown the nearly inevitable progression to symptomatic AD with age from the fourth decade of life in this population, highlighting the urgent need for the design of health plans and clinical trials against AD in individuals with DS. In this sense, a prerequisite is to validate neuropsychological tools and define clinical diagnostic criteria for AD in DS. In contrast with previous assumptions, we demonstrate that cognitive assessment is feasible in adults with DS, and that AD-related cognitive decline can be detected with excellent accuracy in single-points evaluations. Moreover, we also showed the feasibility of performing longitudinal cognitive assessments for the duration of preventive clinical trials and validate the performance of two commonly used neuropsychological tools to be used as cognitive endpoints, which are essential in AD clinical trials. Finally, biomarkers have revolutionized the diagnosis of AD in the general population. These advances must be adapted and applied in DS. In this regard, we have validated the diagnostic and prognostic performance of plasma NfL and have explored a panel of synaptic proteins in CSF as novel biomarkers for AD in DS that may be useful to monitor therapeutic response in AD clinical trials. In brief, the data presented in this thesis has focused on the diagnosis of symptomatic AD and the study of clinical, cognitive, and biomarker changes of AD in adults with DS. These multimodal approaches are essential to provide new insights to the natural history of AD, to establish accurate diagnostic tools, and, potentially, to discover new therapeutic targets.

La Malaltia d'Alzheimer (MA) és el tipus de demència més prevalent a nivell mundial i un dels trastorns més rellevants dins un grup de malalties neurodegeneratives anomenades tauopaties. Aquestes malalties es caracteritzen per la modificació aberrant i acumulació progressiva de la proteïna tau. Tau va ser descrita inicialment com a estabilitzadora de microtúbuls, tot i que també participa en múltiples processos cel·lulars, inclosos la reparació de l'ADN, la plasticitat sinàptica i el manteniment de la funció mitocondrial. Per això, a més de ser un element essencial per a l'homeòstasi cel·lular, tau també pot desencadenar el mal funcionament i la pèrdua neuronal associats a aquest tipus de malalties, especialment a la MA. El nostre grup s'ha centrat en l'estudi de la isoforma llarga neuroespecífica de la Molècula Inhibidora de l'Apoptosi Fas, FAIM-L. Hem estat pioners a descriure funcions úniques d'aquesta proteïna basades en la seva capacitat d'inhibir certes funcions no apoptòtiques de la caspasa-3. Amb això, el nostre grup va ser també el primer a vincular FAIM-L amb la neurodegeneració, en descobrir que es trobava disminuïda tant en pacients amb la MA com en un model de ratolí d'aquesta malaltia. FAIM-L està implicat en el correcte control de l'apoptosi i dels processos sinàptics, vam proposar que la seva pèrdua podia estar afavorint la progressió de la MA. Per explorar aquesta hipòtesi, el nostre objectiu va ser dilucidar els mecanismes moleculars involucrats en la reducció de FAIM-L, les conseqüències de la seva disminució i les implicacions funcionals de la restauració dels nivells de FAIM-L in vivo mitjançant l'ús d'injeccions virals amb vectors adeno-associats. Amb tot això, volem proposar FAIM-L com un element terapèutic potencial per a la MA. En aquest treball, vam observar que la reducció de FAIM-L estava directament relacionada amb la patologia tau, mentre que no depenia de la patologia β-amiloide. A més, utilitzant el model murí de Demència Fronto-temporal lligada a Parkinsonisme (FTDP-17), el ratolí PS19, vam comprovar que aquesta disminució es produïa prèviament al desenvolupament d'altres alteracions patològiques com el deteriorament sinàptic i la gliosi. A més, vam poder veure que estava associada a una disminució dels nivells de XIAP i a un augment anòmal de la ubiquitinació global. Aquesta reducció primerenca de FAIM-L al curs de la patologia ofereix una nova finestra terapèutica que està clarament avalada pels resultats obtinguts després de la modulació de FAIM-L in vivo. Els nostres nous descobriments van mostrar que la restauració de l'expressió de FAIM-L a l'hipocamp dels ratolins PS19, va evitar per complet la pèrdua d'espines dendrítiques i va ajudar a mantenir la integritat sinàptica mitjançant la prevenció de la pèrdua de les proteïnes PSD95 i mGluR2 al compartiment post-sinàptic. En conseqüència, la sobre-expressió de FAIM-L va prevenir l'atròfia cerebral i el deteriorament de l'aprenentatge i la memòria al nostre model. Addicionalment, vam poder reforçar la relació entre FAIM-L i la patologia de tau. Vam poder descriure que la reducció de FAIM-L depèn de l'augment dels nivells de fosforilació de tau. A més, vam reportar una connexió funcional entre aquestes dues proteïnes. En aquest treball, demostrem, per primer cop, que FAIM-L interactua amb les isoformes wild-type i mutant de tau i evita la seva ubiquitinació. En resum, els nostres resultats confirmen la implicació de FAIM-L a l'EA però també l'estableixen com un element essencial per a la supervivència neuronal, el manteniment sinàptic i la memòria. A més, aquestes troballes permeten suggerir que FAIM-L confereix una protecció primerenca davant de les alteracions associades a tau. Per tant, el situen com a diana potencial per a abordatges terapèutics, per a l'EA i possiblement per a FTDP-17 i la resta de tauopaties. La enfermedad de Alzheimer (EA) es el tipo de demencia más prevalente a nivel mundial y uno de los trastornos más relevantes dentro de un grupo de enfermedades neurodegenerativas denominadas tauopatías. Estas enfermedades se caracterizan por la modificación aberrante y acumulación progresiva de la proteína tau. Esta proteína, descrita inicialmente como estabilizadora de microtúbulos, participa también en múltiples procesos celulares, incluidos la reparación del ADN, la plasticidad sináptica y el mantenimiento de la función mitocondrial. Por ello, además de ser un elemento esencial para la homeostasis celular, tau también puede desencadenar el mal funcionamiento y la pérdida neuronal asociados a este tipo de enfermedades, especialmente a la EA. Nuestro grupo se ha centrado en el estudio de la isoforma larga neuroespecífica de la Molécula Inhibidora de la Apoptosis Fas, FAIM-L. Además, hemos sido pioneros en describir funciones únicas de esta proteína basadas en su capacidad de inhibir ciertas funciones no apoptóticas de la caspasa-3. Junto a esto, nuestro grupo fue también el primero en vincular FAIM-L con la neurodegeneración, al encontrar que se encuentra disminuido tanto en pacientes con EA como en un modelo de ratón de dicha enfermedad. Dado que FAIM-L está implicado en el correcto control de la apoptosis y los procesos sinápticos, proponemos que su pérdida puede estar favoreciendo la progresión de la EA. Para explorar esta hipótesis, nuestro objetivo fue dilucidar los mecanismos moleculares involucrados en la reducción de FAIM-L y las consecuencias de su disminución. Además, hemos querido analizar las implicaciones funcionales de la restauración de los niveles de FAIM-L in vivo mediante el uso de inyecciones virales con vectores adeno-asociados. Con todo ello, nos gustaría proponer FAIM-L como un potencial diana terapéutica para la EA. En este trabajo, observamos que la reducción de FAIM-L estaba directamente relacionada con la patología tau mientras que no dependía directamente de la patología β-amiloide. Además, utilizando el modelo murino de Demencia Frontotemporal ligada a Parkinsonismo (FTDP-17), el ratón PS19, comprobamos que esta disminución se producía previamente al desarrollo de otras alteraciones patológicas como el deterioro sináptico y la gliosis. Además, pudimos ver que estaba asociada a una disminución de los niveles de XIAP y a un aumento anómalo de la ubiquitinación global. Esta reducción temprana de FAIM-L en el curso de la patología ofrece una nueva ventana terapéutica que está claramente avalada por los resultados obtenidos tras la modulación de FAIM-L in vivo. Nuestros nuevos hallazgos mostraron que la restauración de la expresión de FAIM-L en el hipocampo de los ratones PS19, evitó por completo la pérdida de espinas dendríticas y ayudó a mantener la integridad sináptica mediante la prevención de la pérdida de las proteínas PSD95 y mGluR2 en el compartimento postsináptico. En consecuencia, la sobreexpresión de FAIM-L previno la atrofia cerebral y el deterioro del aprendizaje y la memoria en nuestro modelo. Adicionalmente, pudimos reforzar a relación entre FAIM-L y la patología de tau. Pudimos describir que la reducción de FAIM-L depende del aumento en los niveles de fosforilación de tau. Además, hemos podido reportar una conexión funcional entre estas dos proteínas. En este trabajo, demostramos, por primera vez, que FAIM-L interactúa con las isoformas wild-type y mutante de tau y evita su ubiquitinación. En resumen, nuestros resultados confirman la implicación de FAIM-L en la EA pero también lo establecen como un elemento esencial para la supervivencia neuronal, el mantenimiento sináptico y la memoria. Además, estos hallazgos permiten sugerir que FAIM-L confiere una protección temprana frente a las alteraciones asociadas a tau. Por tanto, lo sitúan como una diana potencial para abordajes terapéuticos, no solo para la EA sino posiblemente para FTDP-17 y el resto de tauopatías. Alzheimer's disease (AD) is the most prevalent type of dementia worldwide and one of the most relevant disorders among a group of neurodegenerative diseases named tauopathies. These diseases are characterized by the aberrant modification and progressive accumulation of the protein tau. Tau protein, initially described to stabilize microtubules, participates in other multiple cellular processes, including DNA repair, synaptic plasticity, and mitochondrial maintenance. Consequently, it is an essential protein for cellular homeostasis but also can become the trigger of the neuronal failure and loss associated to this type of diseases, especially to AD. Our group has been centred in the study of the neuro-specific long isoform of the Fas Apoptotic Inhibitory Molecule, FAIM-L. Furthermore, we have been pioneers in describing unique roles of this protein through its capacity to inhibit certain non-apoptotic functions of caspase-3. Importantly, our group was the first in linking FAIM-L to neurodegeneration by finding it decreased in both AD patients and in a mouse model of the disease. Since FAIM-L is implicated in the correct control of apoptosis and synaptic processes, we propose that its loss may be promoting the progression of AD. To explore this hypothesis, we aimed to elucidate the molecular mechanisms involved in FAIM-L reduction and the consequences of its decrease. Additionally, we have analysed the functional implications of FAIM-L levels restoration using in vivo adeno-associated viral injections. Therefore, we would like to propose FAIM-L as a potential therapeutical target for AD. Importantly, we found that the reduction of FAIM-L was directly linked to tau pathology and was not directly dependent on amyloid-β pathology. Also, by using the Frontotemporal Dementia linked to Parkinsonism (FTDP-17) mouse model, the PS19 mice, we proved that this decrease occurs before other pathological alterations such as synaptic impairment and reactive gliosis and that it is associated to a decrease in XIAP levels and an anomalous increase in global ubiquitination. This early reduction of FAIM-L in the course of the pathology offers a new therapeutic window that is clearly supported by the results obtained after FAIM-L modulation in vivo. Our novel findings show that FAIM-L expression restoration in the hippocampus of the PS19 mice completely avoided dendritic spine loss and helped maintaining synaptic integrity by preventing PSD95 and mGluR2 losing the postsynaptic compartment. Consequently, FAIM-L overexpression prevented brain atrophy as well as learning and memory impairment in our model. The relationship between FAIM-L and tau pathology is reinforced by our in vitro experiments in which we were able to describe, for the first time, that FAIM-L reduction depends on the increase in phosphorylation levels of tau and, indeed, to report a functional connection between these two proteins. In this work, we also demonstrate that FAIM-L interacts with both wild-type and mutant tau isoforms and avoids its ubiquitination. In summary, our results confirm FAIM-L implication in AD but also settle it an essential element for neuronal survival, synaptic maintenance and cognition. Also, these findings allow to suggest that FAIM-L confers early protection from tau-associated alterations and place it as a potential target for therapeutic approaches, not only for AD but possibly for FTDP-17 and the rest of tauopathies.

Heterozygous hTau mice were used for the study of tau seeding. These mice express the six human tau isoforms, with a high predominance of 3Rtau over 4Rtau. The following groups were assessed: (i) non-inoculated mice aged 9 months (n = 4); (ii) Alzheimer’s Disease (AD)-inoculated mice (n = 4); (iii) Globular Glial Tauopathy (GGT)-inoculated mice (n = 4); (iv) Pick’s disease (PiD)-inoculated mice (n = 4); (v) control-inoculated mice (n = 4); and (vi) inoculated with vehicle alone (n = 2). AD-inoculated mice showed AT8-immunoreactive neuronal pre-tangles, granular aggregates, and dots in the CA1 region of the hippocampus, dentate gyrus (DG), and hilus, and threads and dots in the ipsilateral corpus callosum. GGT-inoculated mice showed unique or multiple AT8-immunoreactive globular deposits in neurons, occasionally extended to the proximal dendrites. PiD-inoculated mice showed a few loose pre-tangles in the CA1 region, DG, and cerebral cortex near the injection site. Coiled bodies were formed in the corpus callosum in AD-inoculated mice, but GGT-inoculated mice lacked globular glial inclusions. Tau deposits in inoculated mice co-localized active kinases p38-P and SAPK/JNK-P, thus suggesting active phosphorylation of the host tau. Tau deposits were absent in hTau mice inoculated with control homogenates and vehicle alone. Deposits in AD-inoculated hTau mice contained 3Rtau and 4Rtau; those in GGT-inoculated mice were mainly stained with anti-4Rtau antibodies, but a small number of deposits contained 3Rtau. Deposits in PiD-inoculated mice were stained with anti-3Rtau antibodies, but rare neuronal, thread-like, and dot-like deposits showed 4Rtau immunoreactivity. These findings show that tau strains produce different patterns of active neuronal seeding, which also depend on the host tau. Unexpected 3Rtau and 4Rtau deposits after inoculation of homogenates from 4R and 3R tauopathies, respectively, suggests the regulation of exon 10 splicing of the host tau during the process of seeding, thus modulating the plasticity of the cytoskeleton.

Modulation of Alzheimer′s disease (AD) risk begins early in life. During embryo development and postnatal maturation, the brain receives maternal physiological influences and establishes epigenetic patterns that build its level of resilience to late-life diseases. The soluble epoxide hydrolase inhibitor N-[1-(1-oxopropyl)-4-piperidinyl]-N′-[4-(trifluoromethoxy)phenyl] urea (TPPU), reported as ant-inflammatory and neuroprotective against AD pathology in the adult 5XFAD mouse model of AD, was administered to wild-type (WT) female mice mated to heterozygous 5XFAD males during gestation and lactation. Two-month-old 5XFAD male and female offspring of vehicle-treated dams showed memory loss as expected. Remarkably, maternal treatment with TPPU fully prevented memory loss in 5XFAD. TPPU-induced brain epigenetic changes in both WT and 5XFAD mice, modulating global DNA methylation (5-mC) and hydroxymethylation (5-hmC) and reducing the gene expression of some histone deacetylase enzymes (Hdac1 and Hdac2), might be on the basis of the long-term neuroprotection against cognitive impairment and neurodegeneration. In the neuropathological analysis, both WT and 5XFAD offspring of TPPU-treated dams showed lower levels of AD biomarkers of tau hyperphosphorylation and microglia activation (Trem2) than the offspring of vehicle-treated dams. Regarding sex differences, males and females were similarly protected by maternal TPPU, but females showed higher levels of AD risk markers of gliosis and neurodegeneration. Taken together, our results reveal that maternal treatment with TPPU impacts in preventing or delaying memory loss and AD pathology by inducing long-term modifications in the epigenetic machinery and its marks., This research was funded by the Spanish Ministerio de Ciencia e Innovación and the Agencia Estatal de Investigación (MCIN/AEI/10.13039/501100011033, grants PID2019-106285RB and PDC2021-121096) and by the European Union “NextGenerationEU”/PRTR; CSIC (2019AEP038); CERCA program/Generalitat de Catalunya; and 2017SGR106 from AGAUR.

Here we revisit tau protein aggregation at primary, secondary, tertiary and quaternary structures. In addition, the presence of non-aggregated tau protein, which has been recently discovered, is also commented on.

G9a is a lysine methyltransferase able to di-methylate lysine 9 of histone H3, promoting the repression of genes involved in learning and memory. Novel strategies based on synthesizing epigenetic drugs could regulate gene expression through histone post-translational modifications and effectively treat neurodegenerative diseases, like Alzheimer's disease (AD). Here, potential G9a inhibitors were identified using a structure-based virtual screening against G9a, followed by in vitro and in vivo screenings. First, screening methods with the AD transgenic Caenorhabditis elegans strain CL2006, showed that the toxicity/function range was safe and recovered age-dependent paralysis. Likewise, we demonstrated that the best candidates direct target G9a by reducing H3 K9me2 in the CL2006 strain. Further characterization of these compounds involved the assessment of the blood-brain barrier-permeability and impact on amyloid-β aggregation, showing promising results. Thus, we present a G9a inhibitor candidate, F, with a novel and potent structure, providing both leads in G9a inhibitor design and demonstrating their participation in reducing AD pathology. Keywords: Alzheimer's disease; G9a methyltransferase; amyloid-β; epigenetics; structure based virtual screening.

Telomere length (TL) is associated with biological aging, consequently influencing the risk of age-related diseases such as Alzheimer’s disease (AD). We aimed to evaluate the potential causal role of TL in AD endophenotypes (i.e., cognitive performance, N = 2233; brain age and AD-related signatures, N = 1134; and cerebrospinal fluid biomarkers (CSF) of AD and neurodegeneration, N = 304) through a Mendelian randomization (MR) analysis. Our analysis was conducted in the context of the ALFA (ALzheimer and FAmilies) study, a population of cognitively healthy individuals at risk of AD. A total of 20 single nucleotide polymorphisms associated with TL were used to determine the effect of TL on AD endophenotypes. Analyses were adjusted by age, sex, and years of education. Stratified analyses by APOE-ɛ4 status and polygenic risk score of AD were conducted. MR analysis revealed significant associations between genetically predicted longer TL and lower levels of CSF Aβ and higher levels of CSF NfL only in APOE-ɛ4 non-carriers. Moreover, inheriting longer TL was associated with greater cortical thickness in age and AD-related brain signatures and lower levels of CSF p-tau among individuals at a high genetic predisposition to AD. Further observational analyses are warranted to better understand these associations., The project leading to these results has received funding from the Alzheimer’s Association (Grant AARG-19-618265). This project has received funding from Instituto de Salud Carlos III (PI19/00119). Additional support has been received from “la Caixa” Foundation (ID 100010434), under agreement LCF/PR/GN17/50300004, the Alzheimer’s Association and an international anonymous charity foundation through the TriBEKa Imaging Platform project (TriBEKa-17-519007), the Health Department of the Catalan Government (Health Research and Innovation Strategic Plan (PERIS) 2016-2020 grant# SLT002/16/00201), and the Universities and Research Secretariat, Ministry of Business and Knowledge of the Catalan Government under the grant no. 2017-SGR-892. All CRG authors acknowledge the support of the Spanish Ministry of Science, Innovation and Universities to the EMBL partnership, the Centro de Excelencia Severo Ochoa, and the CERCA Programme/Generalitat de Catalunya. NV-T is funded by a post-doctoral grant, Juan de la Cierva Incorporación Programme (IJC2020-043216-I), Ministry of Science and Innovation–Spanish State Research Agency. EMAU is supported by the Spanish Ministry of Science, Innovation and Universities - Spanish State Research Agency (RYC2018-026053-I). MS-C receives funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant agreement no. 948677). MS-C also receives funding from the Instituto de Salud Carlos III (PI19/00155) and from the Spanish Ministry of Science, Innovation and Universities (Juan de la Cierva Programme grant IJC2018-037478-I). HZ is a Wallenberg Scholar supported by grants from the Swedish Research Council (#2018-02532); the European Research Council (#681712); Swedish State Support for Clinical Research (#ALFGBG-720931); the Alzheimer Drug Discovery Foundation (ADDF), USA (#201809-2016862); the AD Strategic Fund and the Alzheimer’s Association (#ADSF-21-831376-C, #ADSF-21-831381-C, and #ADSF-21-831377-C); the Olav Thon Foundation; the Erling-Persson Family Foundation, Stiftelsen för Gamla Tjänarinnor, Hjärnfonden, Sweden (#FO2019-0228); the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 860197 (MIRIADE); and the UK Dementia Research Institute at UCL. KB is supported by the Swedish Research Council (#2017-00915); the Alzheimer Drug Discovery Foundation (ADDF), USA (#RDAPB-201809-2016615); the Swedish Alzheimer Foundation (#AF-742881); Hjärnfonden, Sweden (#FO2017-0243); the Swedish state under the agreement between the Swedish government and the County Councils, the ALF-agreement (#ALFGBG-715986); the European Union Joint Program for Neurodegenerative Disorders (JPND2019-466-236); and the National Institute of Health (NIH), USA, (grant #1R01AG068398-01). JDG is supported by the Spanish Ministry of Science and Innovation (RYC-2013-13054). AS-V. is the recipient of an Instituto de Salud Carlos III Miguel Servet II fellowship (CP II 17/00029).

Alzheimer’s disease is characterized by a progressive deterioration of neurons resulting in a steady loss of cognitive functions and memory. Many treatments encounter the challenge of overcoming the blood–brain barrier, thus the intranasal route is a non-invasive effective alternative that enhances the drug delivery in the target organ–the brain–and reduces the side effects associated with systemic administration. This study aimed at developing intranasal gels of donepezil as an approach to Alzheimer’s disease. Three different gels were elaborated and characterized in terms of pH, morphology, gelation temperature, rheology, and swelling. An in vitro release study and an ex vivo permeation in porcine nasal mucosa were conducted on Franz diffusion cells. The tolerability of the formulations was determined by the cytotoxicity in human nasal cells RPMI 2650. Results showed that pluronic gels exhibit the higher release rate and enhanced permeation compared to chitosan gel. Moreover, the combination of Pluronic F-127 and Transcutol® P exerted a synergic effect on the permeation of donepezil through the nasal mucosa. The resulting gels showed suitable tolerance in the RPMI 2650 cell line and physicochemical characteristics for intranasal delivery, and thus gel formulations administered by nasal mucosa could be an alternative strategy to improve the bioavailability of donepezil.

[Objective] The purpose of this study was to examine the levels of cerebrospinal fluid (CSF) apolipoprotein E (apoE) species in Alzheimer’s disease (AD) patients., [Methods] We analyzed two CSF cohorts of AD and control individuals expressing different APOE genotypes. Moreover, CSF samples from the TgF344-AD rat model were included. Samples were run in native- and SDS-PAGE under reducing or non-reducing conditions (with or without β-mercaptoethanol). Immunoprecipitation combined with mass spectrometry or western blotting analyses served to assess the identity of apoE complexes., [Results] In TgF344-AD rats expressing a unique apoE variant resembling human apoE4, a ~35-kDa apoE monomer was identified, increasing at 16.5 months compared with wild-types. In humans, apoE isoforms form disulfide-linked dimers in CSF, except apoE4, which lacks a cysteine residue. Thus, controls showed a decrease in the apoE dimer/monomer quotient in the APOE ε3/ε4 group compared with ε3/ε3 by native electrophoresis. A major contribution of dimers was found in APOE ε3/ε4 AD cases, and, unexpectedly, dimers were also found in ε4/ε4 AD cases. Under reducing conditions, two apoE monomeric glycoforms at 36 kDa and at 34 kDa were found in all human samples. In AD patients, the amount of the 34-kDa species increased, while the 36-kDa/34-kDa quotient was lower compared with controls. Interestingly, under reducing conditions, a ~100-kDa apoE complex, the identity of which was confirmed by mass spectrometry, also appeared in human AD individuals across all APOE genotypes, suggesting the occurrence of aberrantly resistant apoE aggregates. A second independent cohort of CSF samples validated these results., [Conclusion] These results indicate that despite the increase in total apoE content the apoE protein is altered in AD CSF, suggesting that function may be compromised., This work was supported by grants from the Fondo de Investigaciones Sanitarias (FIS; PI15/00665 and PI19-01359, co-funded by the Fondo Europeo de Desarrollo Regional, FEDER “Investing in your future”), from the CIBERNED (Instituto de Salud Carlos III, Spain) and from the Direcció General de Ciència I Investigació, Generalitat Valenciana (AICO/2021/308). We also acknowledge financial support from the Spanish Ministerio de Economía y Competitividad, through the “Severo Ochoa” Programme for Centres of Excellence in R&D (SEV-2017-0723). MPL is supported by a BEFPI fellowship from the Generalitat Valenciana. This study was also supported by the FIS, Contratos para la intensificación de la actividad investigadora en el SNS from Instituto de Salud Carlos III (PI14/01126, PI17/01019, PI20/01473, and INT16/00171 to JF; PI18/00435 to DA; PI14/1561, PI17/01896, and PI20/1330 to AL). This work was also supported by the CIBERNED program (Program 1, Alzheimer Disease to AL and SIGNAL study, www.signalstudy.es), the National Institutes of Health (NIA grants 1R01AG056850-01A1, R21AG056974, and R01AG061566 to JF), and Departament de Salut de la Generalitat de Catalunya, Pla Estratègic de Recerca i Innovació en Salut (SLT002/16/00408 to AL). This work was also supported by Generalitat de Catalunya (SLT006/17/00119 to JF and SLT006/17/00125 to DA). This study was also supported by the Spanish Ministry of Science, Innovation and Universities MICINN/FEDER (PID2019-107738RB-I00, to FA, a fellowship to ISD and the “Maria Maeztu Unit of Excellence Program”) and Instituto de Salud Carlos III (PI18/00893 to GS, co-funded by ERDF, “A way to make Europe”). HZ is a Wallenberg Scholar supported by grants from the Swedish Research Council (#2018-02532); the European Research Council (#681712); the Swedish State Support for Clinical Research (#ALFGBG-720931); the Alzheimer Drug Discovery Foundation (ADDF), USA (#201809-2016862); the AD Strategic Fund and the Alzheimer’s Association (#ADSF-21-831376-C, #ADSF-21-831381-C, and #ADSF-21-831377-C); the Olav Thon Foundation; the Erling-Persson Family Foundation; Stiftelsen för Gamla Tjänarinnor; Hjärnfonden, Sweden (#FO2019-0228); the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 860197 (MIRIADE); the European Union Joint Programme – Neurodegenerative Disease Research (JPND2021-00694); and the UK Dementia Research Institute at UCL (UKDRI-1003). KB is supported by the Swedish Research Council (#2017-00915); the Alzheimer Drug Discovery Foundation (ADDF), USA (#RDAPB-201809-2016615); the Swedish Alzheimer Foundation (#AF-742881); Hjärnfonden, Sweden (#FO2017-0243); the Swedish state under the agreement between the Swedish government and the County Councils, the ALF-agreement (#ALFGBG-715986); the European Union Joint Program for Neurodegenerative Disorders (JPND2019-466-236); the National Institute of Health (NIH), USA (grant #1R01AG068398-01); and the Alzheimer’s Association 2021 Zenith Award (ZEN-21-848495).

One of the pathological hallmarks of Alzheimer’s disease (AD) is the formation of amyloid-β plaques. Since acetylcholinesterase (AChE) promotes the formation of such plaques, the inhibition of this enzyme could slow down the progression of amyloid-β aggregation, hence being complementary to the palliative treatment of cholinergic decline. Antiaggregation assays performed for apigenin and quercetin, which are polyphenolic compounds that exhibit inhibitory properties against the formation of amyloid plaques, reveal distinct inhibitory effects of these compounds on Aβ40 aggregation in the presence and absence of AChE. Furthermore, the analysis of the amyloid fibers formed in the presence of these flavonoids suggests that the Aβ40 aggregates present different quaternary structures, viz., smaller molecular assemblies are generated. In agreement with a noncompetitive inhibition of AChE, molecular modeling studies indicate that these effects may be due to the binding of apigenin and quercetin at the peripheral binding site of AChE. Since apigenin and quercetin can also reduce the generation of reactive oxygen species, the data achieved suggest that multitarget catechol-type compounds may be used for the simultaneous treatment of various biological hallmarks of AD.

Tauopathies are a group of neurodegenerative diseases characterized by the hyperphosphorylation and deposition of tau proteins in the brain. In Alzheimer’s disease, and other related tauopathies, the pattern of tau deposition follows a stereotypical progression between anatomically connected brain regions. Increasing evidence suggests that tau behaves in a “prion-like” manner, and that seeding and spreading of pathological tau drive progressive neurodegeneration. Although several advances have been made in recent years, the exact cellular and molecular mechanisms involved remain largely unknown. Since there are no effective therapies for any tauopathy, there is a growing need for reliable experimental models that would provide us with better knowledge and understanding of their etiology and identify novel molecular targets. In this review, we will summarize the development of cellular models for modeling tau pathology. We will discuss their different applications and contributions to our current understanding of the “prion-like” nature of pathological tau.

Protein tyrosine phosphatase 1B (PTP1B) is a typical member of the PTP family, considered a direct negative regulator of several receptor and receptor-associated tyrosine kinases. This widely localized enzyme has been involved in the pathophysiology of several diseases. More recently, PTP1B has attracted attention in the field of neuroscience, since its activation in brain cells can lead to schizophrenia-like behaviour deficits, anxiety-like effects, neurodegeneration, neuroinflammation and depression. Conversely, PTP1B inhibition has been shown to prevent microglial activation, thus exerting a potent anti-inflammatory effect and has also shown potential to increase the cognitive process through the stimulation of hippocampal insulin, leptin and BDNF/TrkB receptors. Notwithstanding, most research on the clinical efficacy of targeting PTP1B has been developed in the field of obesity and type 2 diabetes mellitus (TD2M). However, despite the link existing between these metabolic alterations and neurodegeneration, no clinical trials assessing the neurological advantages of PTP1B inhibition have been performed yet. Preclinical studies, though, have provided strong evidence that targeting PTP1B could allow to reach different pathophysiological mechanisms at once. herefore, specific interventions or trials should be designed to modulate PTP1B activity in brain, since it is a promising strategy to decelerate or prevent neurodegeneration in aged individuals, among other neurological diseases. The present paper fails to include all neurological conditions in which PTP1B could have a role; instead, it focuses on those which have been related to metabolic alterations and neurodegenerative processes. Moreover, only preclinical data is discussed, since clinical studies on the potential of PTP1B inhibition for treating neurological diseases are still required., This work was supported by funds from the Spanish Ministerio de Ciencia e Innovación (SAF2017-84283‑R and PID2021-123462OB-I00 to AC and CA), the Generalitat de Catalunya (2014SGR‑525 to CA), CIBERNED (Grant CB06/05/2004 to AC) and AARG-NTF-22-924702, (MB). Jordi Olloquequi and Miren Ettcheto are Serra Húnter fellows.

Alzheimer’s disease (AD) is a progressive neurological disorder with multifactorial and heterogeneous causes. AD involves several etiopathogenic mechanisms such as aberrant protein accumulation, neurotransmitter deficits, synaptic dysfunction and neuroinflammation, which lead to cognitive decline. Unfortunately, the currently available anti-AD drugs only alleviate the symptoms temporarily and provide a limited therapeutic effect. Thus, new therapeutic strategies, including multitarget approaches, are urgently needed. It has been demonstrated that a co-treatment of acetylcholinesterase (AChE) inhibitor with other neuroprotective agents has beneficial effects on cognition. Here, we have assessed the neuroprotective effects of chronic dual treatment with a soluble epoxide hydrolase (sEH) inhibitor (TPPU) and an AChE inhibitor (6-chlorotacrine or rivastigmine) in in vivo studies. Interestingly, we have found beneficial effects after chronic low-dose co-treatment with TPPU and 6-chlorotacrine in the senescence-accelerated mouse prone 8 (SAMP8) mouse model as well as with TPPU and rivastigmine co-treatment in the 5XFAD mouse model, in comparison with the corresponding monotherapy treatments. In the SAMP8 model, no substantial improvements in synaptic plasticity markers were found, but the co-treatment of TPPU and 6-chlorotacrine led to a significantly reduced gene expression of neuroinflammatory markers, such as interleukin 6 (Il-6), triggering receptor expressed on myeloid cell 2 (Trem2) and glial fibrillary acidic protein (Gfap). In 5XFAD mice, chronic low-dose co-treatment of TPPU and rivastigmine led to enhanced protein levels of synaptic plasticity markers, such as the phospho-cAMP response element-binding protein (p-CREB) ratio, brain-derived neurotrophic factor (BDNF) and postsynaptic density protein 95 (PSD95), and also to a reduction in neuroinflammatory gene expression. Collectively, these results support the neuroprotectant role of chronic low-dose co-treatment strategy with sEH and AChE inhibitors in AD mouse models, opening new avenues for effective AD treatment.

[cat] Actualment, el tractament de la malaltia d’Alzheimer (MA) és una necessitat mèdica no coberta, ja que només existeixen tres grups de fàrmacs aprovats que no són suficientment eficaços pel control de la malaltia. La naturalesa complexa de la fisiopatologia de la MA i la manca de biomarcadors són els principals obstacles per al desenvolupament de nous fàrmacs pel tractament de la MA. Tenint en compte l’alta taxa de fracàs, l’optimització dels fàrmacs ja en el mercat representa una eina interessant ja que es reduirien els costos en comparació amb l’assaig de nous compostos dirigits a noves dianes. La memantina, un antagonista dels receptors N-metil-D-aspartat (NMDA), ha demostrat beneficis clínics en relació tant en aspectes cognitius i no cognitius, com en vies moleculars implicades en el procés neurodegeneratiu. Malgrat tot, la seva efectivitat és limitada. Per aquest motiu, aquesta tesi doctoral s’ha centrat en caracteritzar farmacològicament en models in vivo dos nous compostos anàlegs a la memantina (l’RL-208 i l’UB-ALT-EV) que s’han desenvolupat amb l’objectiu de millorar l’eficàcia terapèutica de la memantina. Durant la tesi doctoral, es van dur a terme estudis cognitius i de comportament en el nematode C.elegans, en un model de ratolí amb senescència accelerada (SAMP8) i en un model de ratolí transgènic de la MA, el 5XFAD, després del tractament amb els nous antagonistes. A més, es va avaluar molecularment vies associades a la MA per poder avaluar l’efecte modulador dels antagonistes dels receptors NMDA sobre elles. Els resultats obtinguts en el models animals de ratolí demostren com el tractament crònic per via oral a una dosi baixa amb els nous compostos és capaç de millorar les alteracions de la memòria, així com regular les alteracions de la conducta social i el comportament de tipus ansiós. Per altra banda, el compost UB-ALT-EV va demostrar efectes positius sobre els dèficits locomotors i del comportament els cucs C.elegans causats per l’acumulació del pèptid β-amiloide. Així mateix, els antagonistes del receptor NMDA avaluats van reduir els marcadors neuropatològics típics de la MA com la formació i l’acumulació del pèptid Aβ i la fosforilació de la proteïna tau. De la mateixa manera es va demostrar l’efectivitat dels nous compostos en la modulació de vies de senyalització molecular implicades en la neurodegeneració, com la desregulació dels nivells de calci intracel·lular, l’estrès oxidatiu, el flux autofàgic i la neuroinflamació. De manera global, els estudis duts a terme en aquesta tesi permeten demostrar l’efecte neuroprotector dels dos antagonistes del receptor NMDA a més de suggerir que l’optimització de fàrmacs aprovats suposa una estratègia de desenvolupament de nous fàrmacs que permetria l’abordatge de la MA de manera més eficaç. Particularment, donada la capacitat dels nous compostos de regular no només aspectes cognitius i no cognitius sinó també vies moleculars implicades en el procés neurodegeneratiu, aquestes noves teràpies podrien acabar sent considerades com teràpies modificadores de la malaltia i no només tractaments simptomatològics., [eng] Nowadays, the treatment of Alzheimer’s Disease (AD) is an unmet medical need, as there are only three groups of approved drugs that are not sufficiently effective for the control of the disease. The complex nature of the pathophysiology of AD and the lack of biomarkers constitute major obstacles for the development of new drugs for the treatment of AD. Given the high rate of failures, optimisation of already available drugs represents an interesting tool, as the cost would be reduced in comparison to the testing of new compounds against new targets. Memantine, an N-methyl-D-aspartate (NMDA) receptor antagonist, has shown clinical benefits regarding cognitive and non-cognitive aspects and molecular pathways involved in the neurodegenerative process. However, its efficacy is limited. Therefore, this thesis dissertation has focused on the pharmacological characterization of two new memantine-like compounds (RL-208 and UB-ALT-EV) that have been developed with the aim of improving the therapeutic efficacy of memantine. During the research, cognitive and behavioural studies have been performed in the nematode C.elegans, in a mouse model with accelerated senescence (SAMP8) and in a transgenic mouse model of MA, 5XFAD, after the treatment with the new antagonists. Furthermore, the molecular pathways associated to AD were evaluated to evaluate the modulating effect of NMDA receptor antagonists on these pathways. The results obtained with animal mice models demonstrate that the chronic oral treatment at low doses with the new compounds is able to improve memory impairment, as well as to regulate social and anxiety-like behavioural disturbances. Moreover, the compound UB-ALT-EV showed positive effects on locomotor and behavioural deficits in C.elegans worms caused by accumulation of amyloid-β peptide. Additionally, the NMDA receptor antagonists tested reduced typical neuropathological markers of AD, such as Amyloid-β formation and accumulation and tau protein hyperphosphorylation. The efficacy of the new compounds in modulating molecular signaling pathways involved in neurodegeneration, such as dysregulation of intracellular calcium levels, oxidative stress, autophagic flux and neuroinflammation, was also demonstrated. Overall, the studies conducted in this thesis demonstrate the neuroprotective effect of the two NMDA receptor antagonists and suggest that the optimization of approved drugs is a strategy for the development of new drugs that would address AD more effectively. In particular, given the ability of the new compounds to regulate not only cognitive and non-cognitive aspects, but also the molecular pathways involved in the neurodegenerative process, these new therapies could eventually be considered as disease-modifying therapies and not only as symptomatic treatments.

Impaired brain clearance mechanisms may result in the accumulation of aberrant proteins that define Alzheimer's disease (AD). The water channel protein astrocytic aquaporin 4 (AQP4) is essential for brain amyloid-β clearance, but it is known to be abnormally expressed in AD brains. The expression of AQPs is differentially regulated during diverse brain injuries, but, whereas AQP4 expression and function have been studied in AD, less is known about AQP5. AQP5 functions include not only water transport but also cell migration mediated by cytoskeleton regulation. Moreover, AQP5 has been reported to be expressed in astrocytes, which are regulated after ischemic and traumatic injury. Additionally, AQP5 is particularly abundant in the salivary glands suggesting that it may be a crucial factor in gland dysfunction associated with AD. Herein, we aim to determine whether AQP5 expression in submandibular glands and the brain was altered in AD. First, we demonstrated impaired AQP5 expression in submandibular glands in APP/PS1 mice and AD patients. Subsequently, we observed that AQP5 expression was upregulated in APP/PS1 cerebral cortex and confirmed its expression both in astrocytes and neurons. Our findings propose AQP5 as a significant role player in AD pathology, in addition to AQP4, representing a potential target for the treatment of AD. This study was supported by grants from Instituto de Salud Carlos III through the project PI2021/00679) and cofounded by the European Union, Hospital Universitario 12 de Octubre Research Institute (2022/0068), FEDER, Comunidad de Madrid (S2017/BMD-3700; NEUROMETAB-CM), and CIBERNED (CB07/502, PI2021/03). Sí

[cat] La malaltia d’Alzheimer (AD) és el tipus de demència més comú durant l’envelliment i una de les malalties neurodegeneratives més severes. L’AD es caracteritza per una pèrdua de memòria, la deposició de pèptids beta- amiloides (Aβ) i l’agregació de la proteïna Tau hiperfosforilada (p-tau), que promouen la formació de les plaques amiloides i els cabdells neurofibrilars, respectivament; així com la neuroinflamació i l’activació de la micròglia. D’altra banda, durant l’envelliment, hi ha disbacterosi, i s’indueix un increment dels bacteris patogènics, la permeabilitat intestinal i l’estat pro-inflamatori. Conseqüentment, la disbacteriosi pot contribuir al desenvolupament de l’AD a través de diferents elements de l’eix intestí-cervell. La suplementació dietètica amb plasma porcí assecat per atomització (SDP) redueix el deteriorament cognitiu dels ratolins SAMP8 envellits, té efectes anti-inflamatoris a la mucosa intestinal en diferents models murins; i efectes prebiòtics en animals joves. Atesos aquests antecedents, la hipòtesi que es planteja en aquesta tesi és que els efectes prebiòtics del plasma assecat poden estar implicats en els seus efectes neuroprotectors. Es van utilitzar ratolins SAMP8 de 2 mesos d’edat (grup de referència) i de 6 mesos d’edat, que es van dividir en dos grups segons el pinso experimental que van rebre durant 4 mesos, pinso control o pinso suplementat amb l’SDP al 8%. Els ratolins envellits presentaven un empitjorament de la funció cognitiva amb una reducció de la memòria a curt i llarg termini, a més d’una menor abundància cortical d’una neurotrofina relacionada amb la plasticitat sinàptica, com és el BDNF. La suplementació amb l’SDP va prevenir aquests efectes. La senescència va promoure l’augment del fragment beta soluble de la proteïna precursora amiloide (sAPP-β) i la generació de pèptids neurotòxics Aβ. La suplementació amb l’SDP va disminuir l’abundància d’aquests marcadors, així com també va reduir l’expressió de la β-secretasa 1 (Bace1), essencial en aquesta via amiloidogènica. L’envelliment va incrementar l’abundància de la proteïna p-tau i de les proteïnes quinases encarregades de la seva hiperfosforilació, la qual cosa es va prevenir amb la suplementació amb l’SDP. La micròglia, les cèl·lules immunitàries específiques del sistema nerviós central, estava més activada al còrtex dels ratolins senescents, i aquest procés va anar acompanyat d’una major neuroinflamació. La suplementació amb l’SDP va atenuar la neuroinflamació i l’activació de la micròglia posant de manifest els seus efectes anti-inflamatoris. Així doncs, la suplementació amb l’SDP redueix els marcadors neuropatològics de l’AD. Paral·lelament, es va demostrar que els ratolins SAMP8 envellits mostraven un major grau d’inflamació sistèmica i a la mucosa de còlon. Aquest procés inflamatori anava acompanyat d’una disminució de l’expressió de les proteïnes relacionades amb la producció de moc (Muc2, Tff3) i del complex d’unió (Ocludina). La suplementació amb l’SDP va atenuar la inflamació sistèmica i del còlon, i va millorar l’estructura de la barrera. Aquests efectes de l’envelliment es van relacionar amb la reducció de l’abundància de bacteris promotors de la salut, com per exemple, els gèneres Lactobacillus i Pediococcus, i en va incrementar d’altres associats amb la inflamació, com els gèneres Johnsonella i Erysipelothrix. En canvi, la suplementació amb l’SDP va exercir efectes prebiòtics, i va induir el creixement dels bacteris probiòtics i en va disminuir els patogènics. En conclusió, els efectes anti-inflamatoris de la suplementació amb l’SDP redueixen la inflamació sistèmica, a la mucosa de còlon, a més presenta propietats neuroprotectores en els ratolins envellits; aquests efectes es correlacionen amb la promoció d’espècies probiòtiques, la qual cosa suggereixen que l’eix intestí cervell pot estar involucrat en la prevenció de l’AD., [eng] Alzheimer's disease (AD) is the most common type of dementia during aging and one of the most severe neurodegenerative diseases. AD is characterized by memory loss, amyloid-beta (Aβ) deposition, aggregation of hyperphosphorylated Tau protein (p-tau), leading to neuroinflammation and activation of microglia. Aging is also accompanied by dysbiosis, which is an alteration of the microbiota, where increases pathogenic bacteria; as well as increased intestinal permeability and inflammation. Consequently, dysbiosis may contribute to the development of AD via the gut-brain axis. Supplementation with spray-dried porcine plasma (SDP) attenuates cognitive decline in aged SAMP8 mice, reduces inflammatory response of the intestinal mucosa in different murine models and shows prebiotic effects in weaned animals. Therefore, the hypothesis proposed is that the prebiotic effects of SDP may be involved in its neuroprotective effects. Experiments were performed in 2-month-old SAMP8 mice fed a standard diet and in 6-month-old SAMP8 mice fed a control or an 8% SDP supplemented diet for 4 months. Aging impaired short- and long-term memory, reduced cortical BDNF abundance, and increased soluble beta amyloid precursor protein (sAPP-β) and Aβ peptides. SDP supplementation prevented all these aging effects, and reduced the expression of β-secretase1 (Bace1), which is essential in the amyloidogenic pathway. Aging increased the abundance of p-tau and the kinases responsible for its hyperphosphorylation, which was also prevented by SDP supplementation. Senescence activated microglia, the immune cells specific to the central nervous system, increasing neuroinflammation. These effects were attenuated by SDP supplementation. Thus, SDP supplementation reduces neuropathological markers of AD. In parallel, aged SAMP8 mice showed increased systemic and colonic inflammation, as well as, reduced Muc2, Tff3 and Occludin expression. SDP supplementation attenuated systemic and colonic inflammation, and improved barrier structure. Aging reduced the abundance of health-promoting bacteria, such as Lactobacillus and Pediococcus, and increased inflammation-associated bacteria, such as Johnsonella and Erysipelothrix. In contrast, SDP supplementation induced the growth of probiotic bacteria and decreased the pathogenic ones. In conclusion, SDP supplementation has anti-inflammatory and neuroprotective effects, as well as prebiotic properties in aged mice, suggesting that the gut-brain axis may be involved in the effect of SDP on AD progression.

Altered protein phosphorylation is a major pathologic modification in tauopathies and Alzheimer’s disease (AD) linked to abnormal tau fibrillar deposits in neurofibrillary tangles (NFTs) and pre-tangles and β-amyloid deposits in AD. hTau transgenic mice, which express 3R and less 4R human tau with no mutations in a murine knock-out background, show increased tau deposition in neurons but not NFTs and pre-tangles at the age of nine months. Label-free (phospho)proteomics and SWATH-MS identified 2065 proteins in hTau and wild-type (WT) mice. Only six proteins showed increased levels in hTau; no proteins were down-regulated. Increased tau phosphorylation in hTau was detected at Ser199, Ser202, Ser214, Ser396, Ser400, Thr403, Ser404, Ser413, Ser416, Ser422, Ser491, and Ser494, in addition to Thr181, Thr231, Ser396/Ser404, but not at Ser202/Thr205. In addition, 4578 phosphopeptides (corresponding to 1622 phosphoproteins) were identified in hTau and WT mice; 64 proteins were differentially phosphorylated in hTau. Sixty proteins were grouped into components of membranes, membrane signaling, synapses, vesicles, cytoskeleton, DNA/RNA/protein metabolism, ubiquitin/proteasome system, cholesterol and lipid metabolism, and cell signaling. These results showed that over-expression of human tau without pre-tangle and NFT formation preferentially triggers an imbalance in the phosphorylation profile of specific proteins involved in the cytoskeletal–membrane-signaling axis.

[eng] The neuropathological hallmarks of Alzheimer’s disease are senile plaques, extracellular deposits of amyloid-β peptide (Aβ), and neurofibrillary tangles, intracellular aggregates of hyperphosphorylated Tau protein (P-Tau). At the functional level, Alzheimer’s disease involves synaptic dysfunction, aberrant network activity, and cognitive impairment, eventually resulting in dementia. Remarkably, individuals presenting Aβ and P-Tau without cognitive impairment have been reported. This cognitive resilience to Alzheimer’s disease is believed to involve synaptic preservation. In Alzheimer’s disease, Aβ and P-Tau exert toxicity either independently or synergistically. However, Tau is pivotal in mediating the synaptotoxicity induced by Aβ, neurodegeneration, and cognitive decline. Tau is a canonical microtubule-binding protein. Nevertheless, its physiological roles are currently recognized to extend far beyond microtubule stabilization, including participation in synaptic plasticity and DNA protection. Although the regulation of Tau function depends on phosphorylation, the association of P-Tau with Alzheimer’s disease and other tauopathies has established the notion that it is invariably pathological. Aberrant network activity, hyperexcitability, and altered oscillatory activity, which indicate an imbalance between excitation and inhibition in neural circuits, have been described in Alzheimer’s disease. Hence, dysfunction of the GABAergic system has been suggested to underlie network abnormalities. Studies from our group have revealed synaptic alterations in the GABAergic septohippocampal pathway and its implication in the emergence of abnormal hippocampal oscillatory activity in J20 and VLW animals, Alzheimer’s disease mouse models that accumulate Aβ and P-Tau, respectively. GABAergic neurons in the medial septum control GABAergic hippocampal interneurons, which govern principal cell activity, hence modulating hippocampal oscillations. Given the myriad of physiological roles of Tau and the impact of phosphorylation on its activity, we have studied its phosphorylation pattern in physiological and pathological conditions in mice and human subjects. Our data show that control mice and human subjects present Tau phosphorylated at Thr205 and Ser262 in the soma of hippocampal interneurons, pointing to a physiological role of these P-Tau species in this neuron population. Moreover, we have observed these P-Tau species in the soma of hippocampal interneurons in Alzheimer’s disease patients and in J20 and VLW mice. The presence of Tau phosphorylated at Thr205 correlates with the Aβ plaque burden in J20 animals, suggesting an inductive effect of Aβ on Tau phosphorylation at this site. Conversely, the accumulation of Tau phosphorylated at Ser262 is unchanged in pathological conditions, implying a physiological role of this P-Tau. In addition, our data indicate that 3 the presence of mutant human Tau in pyramidal neurons in VLW mice induces the phosphorylation of endogenous murine Tau at Thr231 in hippocampal interneurons. Furthermore, to recapitulate the complete spectrum of Alzheimer’s disease pathology, we have crossed J20 and VLW mice. In the resulting J20/VLW animals, which simultaneously present Aβ and P-Tau, our findings reveal no differences in Aβ burden or P-Tau levels compared to single transgenic mice. However, J20/VLW animals present a distinct Tau phosphorylation pattern in hippocampal interneurons. Our data show that GABAergic septohippocampal innervation is dramatically altered in J20 and VLW animals, whereas it is preserved in J20/VLW mice. Moreover, we have found that hippocampal oscillations are partially conserved in J20/VLW animals, in contrast to single transgenic mice. Finally, J20/VLW mice display preserved cognitive function, contrary to J20 and VLW animals. Taken together, our findings point to a physiological role of Tau phosphorylation in the somatodendritic compartment of hippocampal interneurons. Moreover, they suggest that a particular Tau phosphorylation signature in this neuron population protects against the loss of GABAergic septohippocampal innervation, thereby avoiding alterations in hippocampal oscillatory activity and, thus, preventing cognitive impairment in J20/VLW mice. Lastly, these data highlight J20/VLW mice as a suitable animal model to explore the cognitive resilience to Alzheimer’s disease.

Treball de Grau de Farmàcia. Facultat de Farmàcia i Ciències de l'AlimentacióUniversitat de Barcelona, Curs: 2021-2022, Tutiora: Maria Pilar Vinardell Martinez Hidalgo., IV Premi Clara Campoamor al millor Treball Final de Grau amb perspectiva de gènere de la Universitat de Barcelona, curs 2021-2022. Accèssit. Branca de Ciències de la Salut., [spa] A lo largo de los años, con la sobrerrepresentación de los hombres en las investigaciones científicas, se han obtenido resultados y conocimientos sesgados perjudicando a las mujeres. Sin una representación de ambos sexos, no se puede asegurar que aquello que se ha descubierto en un sexo sea aplicable para el otro. En estos últimos años, ha ganado importancia el estudio de las diferencias sexuales y se han redactado una serie de recomendaciones (como las guías SAGER) para garantizar la equidad de sexo y género en las investigaciones biomédicas. Respecto a las enfermedades neurodegenerativas, se conoce que existen destacadas diferencias en la incidencia, la gravedad, la progresión y el pronóstico de varios de estos trastornos. Es por ello por lo que es primordial analizar las diferencias sexuales para mejorar el conocimiento de la enfermedad y así obtener terapias farmacológicas más efectivas. Para evaluar esta problemática en la situación actual, se procede a una revisión de 41 artículos procedentes de PubMed de los últimos 5 años sobre estudios preclínicos utilizando ratones, ratas y perros para el estudio de la enfermedad de Alzheimer. Los resultados indican una mayoría de estudios realizados en animales machos, seguido de ambos sexos y, por último y en igual número, los realizados en hembras y los que no concretaron el sexo. De esta manera, se confirma que sigue existiendo un sesgo de sexo en la investigación de la enfermedad de Alzheimer y esto podría aplicarse a otras patologías., [eng]Over the years, with the overrepresentation of men in scientific research, biased results and knowledge have been obtained to the detriment of women. Without a representation of both sexes, it cannot be ensured that what has been discovered in one sex is applicable to the other. Recently, the study of sexual differences has gained importance and a series of recommendations have been written (such as the SAGER guidelines) to guarantee sex and gender equity in biomedical research. Referring to neurodegenerative diseases, it is known that there are significant differences in the incidence, severity, progression, and outcome of several of these disorders. That is why it is essential to analyze sexual differences to improve knowledge of the disease and thus obtain more effective pharmacological therapies. To assess this problem in the actual situation, a review of 41 articles from PubMed from the last 5 years on preclinical studies using mice, rats, and dogs for the study of Alzheimer's disease is carried out. The results show most studies were carried out on male animals, followed by both sexes and, lastly and in equal number, those carried out on females and those that did not specify the sex. In such a way, it is confirmed that there is still a sex bias in Alzheimer's disease research, and this could be applied to other pathologies.

Alzheimer disease is an age-linked neurodegenerative disorder representing one of the greatest medical care challenges of our century. Several drugs are useful in ameliorating the symptoms, even if none could stop or reverse disease progression. The standard approach is represented by the cholinesterase inhibitors (ChEIs) that restore the levels of acetylcholine (ACh) by inhibiting the acetylcholinesterase (AChE). Still, their limited efficacy has prompted researchers to develop new ChEIs that could also reduce the oxidative stress by exhibiting antioxidant properties and by chelating the main metals involved in the disease. Recently, we developed some derivatives constituted by a 2-amino-pyrimidine or a 2-amino-pyridine moiety connected to various aromatic groups by a flexible amino-alkyl linker as new dual inhibitors of AChE and butyrylcholinesterase (BChE). Following our previous studies, in this work we explored the role of the flexible linker by replacing the amino group with an amide or a carbamic group. The most potent compounds showed higher selectivity against BChE in respect to AChE, proving also to possess a weak anti-aggregating activity toward Aβ42 and tau and to be able to chelate Cu2+ and Fe3+ ions. Molecular docking and molecular dynamic studies proposed possible binding modes with the enzymes. It is noteworthy that these compounds were predicted as BBB-permeable and showed low cytotoxicity on the human brain cell line.

Background: Brain damage associated with Alzheimer's disease (AD) occurs even decades before the symptomatic onset, raising the need to investigate its progression from prodromal stages. In this context, animal models that progressively display AD pathological hallmarks (e.g. TgF344-AD) become crucial. Translational technologies, such as magnetic resonance spectroscopy (MRS), enable the longitudinal metabolic characterization of this disease. However, an integrative approach is required to unravel the complex metabolic changes underlying AD progression, from early to advanced stages.Methods: TgF344-AD and wild-type (WT) rats were studied in vivo on a 7 Tesla MRI scanner, for longitudinal quantitative assessment of brain metabolic profile changes using MRS. Disease progression was investigated at 4 time points, from 9 to 18 months of age, and in 4 regions: cortex, hippocampus, striatum, and thalamus.Results: Compared to WT, TgF344-AD rats replicated common findings in AD patients, including decreased N-acetylaspartate in the cortex, hippocampus and thalamus, and decreased glutamate in the thalamus and striatum. Different longitudinal evolution of metabolic concentration was observed between TgF344-AD and WT groups. Namely, age-dependent trajectories differed between groups for creatine in the cortex and thalamus and for taurine in cortex, with significant decreases in Tg344-AD animals; whereas myo-inositol in the thalamus and striatum showed greater increase along time in the WT group.Additional analysis revealed divergent intra- and inter-regional metabolic coupling in each group. Thus, in cortex, strong couplings of N-acetylaspartate and creatine with myo-inositol in WT, but with taurine in TgF344-AD rats were observed; whereas in the hippocampus, myo-inositol, taurine and choline compounds levels were highly correlated in WT but not in TgF344-AD animals. Furthermore, specific cortex-hippocampus-striatum metabolic crosstalks were found for for taurine levels in the WT group but for myo-inositol levels in the TgF344-AD rats.Conclusion: With a systems biology perspective of metabolic changes in AD pathology, our results shed light into the complex spatio-temporal metabolic rewiring in this disease, reported here for the first time. Age- and tissue-dependent imbalances between myo-inositol, taurine and other metabolites, such as creatine, unveil their role in disease progression, while pointing to the inadequacy of the latter as an internal reference for quantification.

Background High-density oligomers of the prion protein (HDPs) have previously been identified in brain tissues of patients with rapidly progressive Alzheimer’s disease (rpAD). The current investigation aims at identifying interacting partners of HDPs in the rpAD brains to unravel the pathological involvement of HDPs in the rapid progression. Methods HDPs from the frontal cortex tissues of rpAD brains were isolated using sucrose density gradient centrifugation. Proteins interacting with HDPs were identified by co-immunoprecipitation coupled with mass spectrometry. Further verifications were carried out using proteomic tools, immunoblotting, and confocal laser scanning microscopy. Results We identified rpAD-specific HDP-interactors, including the growth arrest specific 2-like 2 protein (G2L2). Intriguingly, rpAD-specific disturbances were found in the localization of G2L2 and its associated proteins i.e., the end binding protein 1, α-tubulin, and β-actin. Discussion The results show the involvement of HDPs in the destabilization of the neuronal actin/tubulin infrastructure. We consider this disturbance to be a contributing factor for the rapid progression in rpAD.

Highlight • The role of Amaryllidaceae species from Ecuador as source of new drugs. • High amount of lycorine-type alkaloids in Phaedranassa dubia by GC-MS. • In vitro potential of Phaedranassa brevifolia as cholinesterase inhibitor. • Theoretical inhibitory activity of alkaloids against cholinesterase enzymes., Alzheimer's disease is considered the most common cause of dementia and, in an increasingly aging population worldwide, the quest for treatment is a priority. Amaryllidaceae alkaloids are of main interest because of their cholinesterase inhibition potential, which is the main palliative treatment available for this disease. We evaluated the alkaloidal profile and the in vitro inhibitory activity on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) of bulb alkaloid extract of Phaedranassa dubia and Phaedranassa brevifolia collected in Ecuador. Using gas chromatography coupled to mass spectrometry (GC-MS), we identified typical Amaryllidaceae alkaloids in these species, highlighting the presence of lycorine-type alkaloids in P. dubia and haemanthamine/crinine-type in P. brevifolia. The species P. dubia and P. brevifolia showed inhibitory activities against AChE (IC50 values of 25.48 ± 0.39 and 3.45 ± 0.29 μg.mL−1, respectively) and BuChE (IC50 values of 114.96 ± 4.94 and 58.89 ± 0.55 μg.mL−1, respectively). Computational experiments allowed us to understand the interactions of the alkaloids identified in these samples toward the active sites of AChE and BuChE. In silico, some alkaloids detected in these Amaryllidaceae species presented higher estimated binding free energy toward BuChE than galanthamine. This is the first study about the alkaloid profile and biological potential of P. brevifolia species.

Overstimulation of N-methyl-d-aspartate receptors (NMDARs) is the leading cause of brain excitotoxicity and often contributes to neurodegenerative diseases such as Alzheimer’s Disease (AD), the most common form of dementia. This study aimed to evaluate a new NMDA receptor antagonist (UB-ALT-EV) and memantine in 6-month-old female 5XFAD mice that were exposed orally to a chronic low-dose treatment. Behavioral and cognitive tests confirmed better cognitive performance in both treated groups. Calcium-dependent protein calpain-1 reduction was found after UB-ALT-EV treatment but not after memantine. Changes in spectrin breakdown products (SBDP) and the p25/p35 ratio confirmed diminished calpain-1 activity. Amyloid β (Aβ) production and deposition was evaluated in 5XFAD mice and demonstrated a robust effect of NMDAR antagonists on reducing Aβ deposition and the number and size of Thioflavin-S positive plaques. Furthermore, glycogen synthase kinase 3β (GSK3β) active form and phosphorylated tau (AT8) levels were diminished after UB-ALT-EV treatment, revealing tau pathology improvement. Because calpain-1 is involved in autophagy activation, autophagic proteins were studied. Strikingly, results showed changes in the protein levels of unc-51-like kinase (ULK-1), beclin-1, microtubule-associated protein 1A/1B-light chain 3(LC3B-II)/LC3B-I ratio, and lysosomal-associated membrane protein 1 (LAMP-1) after NMDAR antagonist treatments, suggesting an accumulation of autophagolysosomes in 5XFAD mice, reversed by UB-ALT-EV. Likewise, treatment with UB-ALT-EV recovered a WT mice profile in apoptosis markers Bcl-2, Bax, and caspase-3. In conclusion, our results revealed the potential neuroprotective effect of UB-ALT-EV by attenuating NMDA-mediated apoptosis and reducing Aβ deposition and deposition jointly with the autophagy rescue to finally reduce cognitive alterations in a mice model of familial AD.

Objective To investigate the safety and efficacy of N-acetyl-l-leucine (NALL) on symptoms, functioning, and quality of life in pediatric (≥ 6 years) and adult Niemann–Pick disease type C (NPC) patients. Methods In this multi-national, open-label, rater-blinded Phase II study, patients were assessed during a baseline period, a 6-week treatment period (orally administered NALL 4 g/day in patients ≥ 13 years, weight-tiered doses for patients 6–12 years), and a 6-week post-treatment washout period. The primary Clinical Impression of Change in Severity (CI-CS) endpoint (based on a 7-point Likert scale) was assessed by blinded, centralized raters who compared randomized video pairs of each patient performing a pre-defined primary anchor test (8-Meter Walk Test or 9-Hole Peg Test) during each study periods. Secondary outcomes included cerebellar functional rating scales, clinical global impression, and quality of life assessments. Results 33 subjects aged 7–64 years with a confirmed diagnosis of NPC were enrolled. 32 patients were included in the primary modified intention-to-treat analysis. NALL met the CI-CS primary endpoint (mean difference 0.86, SD = 2.52, 90% CI 0.25, 1.75, p = 0.029), as well as secondary endpoints. No treatment-related serious adverse events occurred. Conclusions NALL demonstrated a statistically significant and clinical meaningfully improvement in symptoms, functioning, and quality of life in 6 weeks, the clinical effect of which was lost after the 6-week washout period. NALL was safe and well-tolerated, informing a favorable benefit-risk profile for the treatment of NPC. Clinicaltrials.gov identifier NCT03759639.

Glycogen synthase kinase 3β (GSK3β) is a core protein, with a relevant role in many neurodegenerative disorders including Alzheimer's disease. The enzyme has been largely studied as a potential therapeutic target for several neurological diseases. Unfortunately, preclinical and clinical studies with several GSK3β inhibitors have failed due to many reasons such as excessive toxicity or lack of effects in human subjects. We previously reported that meridianins are potent GSK3β inhibitors without altering neuronal viability. In the present work, we examine whether meridianins are capable to inhibit neural GSK3β in vivo and if such inhibition induces improvements in the 5xFAD mouse model of Alzheimer's Disease. Direct administration of meridianins in the third ventricle of 5xFAD mice induced robust improvements of recognition memory and cognitive flexibility as well as a rescue of the synaptic loss and an amelioration of neuroinflammatory processes. In summary, our study points out meridianins as a potential compound to treat neurodegenerative disorders associated with an hyperactivation of GSK3β such as Alzheimer's disease. Keywords: GSK3β; astrocytes; learning; memory; microglia.

Brain aging and dementia are current problems that must be solved. The levels of imidazoline 2 receptors (I(2)-IRs) are increased in the brain in Alzheimer’s disease (AD) and other neurodegenerative diseases. We tested the action of the specific and selective I(2)-IR ligand B06 in a mouse model of accelerated aging and AD, the senescence-accelerated mouse prone 8 (SAMP8) model. Oral administration of B06 for 4 weeks improved SAMP8 mouse behavior and cognition and reduced AD hallmarks, oxidative stress, and apoptotic and neuroinflammation markers. Likewise, B06 regulated glial excitatory amino acid transporter 2 and N-methyl-d aspartate 2A and 2B receptor subunit protein levels. Calcineurin (CaN) is a phosphatase that controls the phosphorylation levels of cAMP response element-binding (CREB), apoptotic mediator BCL-2-associated agonist of cell death (BAD) and GSK3β, among other molecules. Interestingly, B06 was able to reduce the levels of the CaN active form (CaN A). Likewise, CREB phosphorylation, BAD gene expression, and other factors were modified after B06 treatment. Moreover, phosphorylation of a target of CaN, nuclear factor of activated T-cells, cytoplasmic 1 (NFAT(C1)), was increased in B06-treated mice, impeding the transcription of genes related to neuroinflammation and neural plasticity. In summary, this I(2) imidazoline ligand can exert its beneficial effects on age-related conditions by modulating CaN pathway action and affecting several molecular pathways, playing a neuroprotective role in SAMP8 mice. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s11357-020-00281-2) contains supplementary material, which is available to authorized users.

Alzheimer's disease (AD) is the most common form of dementia. Its neurodegenerative nature and the lack of a curative treatment result in a substantial burden for healthcare systems and society. This study aimed to analyze the hospital incidence and mortality of AD in Spain and to evaluate patients' use of healthcare resources and direct medical costs.Admission records of patients with AD treated in hospitals in Spain between 2011 and 2016 were selected from a Spanish hospital discharge database.Records of 7,894 patients with diagnosed AD were analyzed. Hospital incidence was 3.7 per 10,000 persons over the study period, 2.9 and 4.4 for males and females, respectively. In-hospital mortality was 9.5%; both hospital incidence and in-hospital mortality increased over the study period. Mortality was principally associated with acute respiratory failure and other diseases of the respiratory system and heart failure. Annual medical costs of specialized care increased slightly during the study period, with a mean annual cost per patient of €4,969.AD is responsible for an increasing proportion of hospitalizations in Spain and raising medical costs, which highlights the importance of early detection and optimized care.

The inhibition of the enzyme soluble epoxide hydrolase (sEH) has demonstrated clinical therapeutic effects in several peripheral inflammatory-related diseases, with 3 compounds in clinical trials. However, the role of this enzyme in the neuroinflammation process has been largely neglected. Herein, we disclose the pharmacological validation of sEH as a novel target for the treatment of Alzheimer's disease (AD). Evaluation of cognitive impairment and pathological hallmarks were used in 2 models of age-related cognitive decline and AD using 3 structurally different and potent sEH inhibitors as chemical probes. sEH is upregulated in brains from AD patients. Our findings supported the beneficial effects of central sEH inhibition, regarding reducing cognitive impairment, neuroinflammation, tau hyperphosphorylation pathology, and the number of amyloid plaques. This study suggests that inhibition of inflammation in the brain by targeting sEH is a relevant therapeutic strategy for AD., This study was supported by the Ministerio de Economía, Industria y Competitividad (Agencia Estatal de Investigación, AEI) and Fondo Europeo de Desarrollo Regional (MINECO-FEDER) (Projects SAF2017-82771, SAF2016-77703, Fundació La Caixa (project CI18-00002) and SAF2015-68749) and Generalitat de Catalunya (2017 SGR 106). S.C. and E.P. thank the Universitat de Barcelona and the Institute of Biomedicine of the Universitat de Barcelona (IBUB), respectively, for PhD grants. R.L. and D.P.-I. thank the Ministerio de Educación, Cultura y Deporte for PhD grants (FPU program). We would also like to thank Xunta de Galicia (ED431C 2018/21) and Ministerio de Economía, Industria y Competitividad (Innopharma Project) and Fondo Europeo de Desarrollo Regional (MINECO-FEDER). This study was also supported, in part, by grants from the National Institute of Environmental Health Sciences (NIEHS), the RIVER Award, NIEHS/R35 ES030443, and NIEHS Superfund Research Program P42 ES004699. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

BACKGROUND: Fundacio ACE is a non-profit organization providing care based on a holistic model to persons with cognitive disorders and their families for 25 years in Barcelona, Spain. Delivering care to this vulnerable population amidst the COVID-19 pandemic has represented a major challenge to our institution. OBJECTIVE: To share our experience in adapting our model of care to the new situation to ensure continuity of care. METHODS: We detail the sequence of events and the actions taken within Fundacio ACE to swiftly adapt our face-to-face model of care to one based on telemedicine consultations. We characterize individuals under follow-up by the Memory Unit from 2017 to 2019 and compare the number of weekly visits in 2020 performed before and after the lockdown was imposed. RESULTS: The total number of individuals being actively followed by Fundacio ACE Memory Unit grew from 6,928 in 2017 to 8,147 in 2019. Among those newly diagnosed in 2019, most patients had mild cognitive impairment or mild dementia (42% and 25%, respectively). Weekly visits dropped by 60% following the suspension of face-to-face activity. However, by April 24 we were able to perform 78% of the visits we averaged in the weeks before confinement began. DISCUSSION: We have shown that Fundacio ACE model of care has been able to successfully adapt to a health and social critical situation as COVID-19 pandemic. Overall, we were able to guarantee the continuity of care while preserving the safety of patients, families, and professionals. We also seized the opportunity to improve our model of care.

Prior studies have described distinct patterns of brain gray matter and white matter alterations in Alzheimer's disease (AD) and frontotemporal lobar degeneration (FTLD), as well as differences in their cerebrospinal fluid (CSF) biomarkers profiles. We aim to investigate the relationship between early‐onset AD (EOAD) and FTLD structural alterations and CSF biomarker levels. We included 138 subjects (64 EOAD, 26 FTLD, and 48 controls), all of them with a 3T MRI brain scan and CSF biomarkers available (the 42 amino acid‐long form of the amyloid‐beta protein [Aβ42], total‐tau protein [T‐tau], neurofilament light chain [NfL], neurogranin [Ng], and 14‐3‐3 levels). We used FreeSurfer and FSL to obtain cortical thickness (CTh) and fraction anisotropy (FA) maps. We studied group differences in CTh and FA and described the “AD signature” and “FTLD signature.” We tested multiple regression models to find which CSF‐biomarkers better explained each disease neuroimaging signature. CTh and FA maps corresponding to the AD and FTLD signatures were in accordance with previous literature. Multiple regression analyses showed that the biomarkers that better explained CTh values within the AD signature were Aβ and 14‐3‐3; whereas NfL and 14‐3‐3 levels explained CTh values within the FTLD signature. Similarly, NfL levels explained FA values in the FTLD signature. Ng levels were not predictive in any of the models. Biochemical markers contribute differently to structural (CTh and FA) changes typical of AD and FTLD.

La malaltia d'Alzheimer (MA) és un trastorn neurodegeneratiu progressiu relacionat amb l'edat descrit tradicionalment a través de la simptomatologia cognitiva i neuropsiquiàtrica/conductual. No obstant això, les disfuncions psicomotores i el deteriorament motor segueixen poc explorats. El model 3xTg-AD mostra les alteracions neuropatològiques i cognitives que caracteritzen la malaltia de manera semblant a la que ocorre en humans, presentant plaques β-amiloides a l'escorça i l'hipocamp als 12 mesos d'edat repartides per tot l'escorça. Posteriorment, als 15 mesos, els embolics intraneuronals de Tau acompanyen aquesta propagació a l'escorça cerebral. Aquesta investigació es basa en la Classificació Internacional de Funcionament i Discapacitat, que s'utilitza a tot el món en la rehabilitació de patologies neurodegeneratives, inclosa la MA, i des d'un enfocament del curs vital associat a l'envelliment normal, accelerat i patològic reproduïble en diferents contextos de recerca translacional. Per a l'estudi de la MA, es van incloure dues fases de recerca. En una primera fase, es van caracteritzar les signatures motrius primàries i secundàries de la disfunció psicomotora en l'envelliment normal i la malaltia d'Alzheimer. A la fase 1 es van incloure ratolins mascles 3xTg-AD i NTg de 6 i 12 mesos. En la segona fase, es van modular i integrar les signatures primàries i secundàries sota l'exploració de factors externs. Es van incloure ratolins mascles 3xTg-AD i C57BL/6 entre els 13 i els 16 mesos d'edat, i també es van incloure ratolins mascles i femelles 3xTg-AD i NTg de 12 i 16 mesos. Les proves de psicomotricitat van avaluar el rendiment a partir de la marxa espontània, l'activitat exploratòria, la força muscular i la resistència física. A més, es van incloure fenotips de fragilitat i fenotips específics com el reflex d'enganxament i el geotaxi. A més, es van realitzar estudis de sarcopènia i anàlisi de l'eix HPA. Per primera vegada, els resultats informen de la classificació de signatures primàries i secundàries de disfuncions psicomotores en el model de ratolins 3xTg-AD. Es van detectar com a signatures primàries presents en la marxa i l'activitat exploratòria a partir de l'estudi de variables quantitatives i qualitatives del rendiment psicomotor. Mostren una disminució de la longitud, velocitat i cadència del pas, modificada per alteracions posturals com la cifosi estructural en ratolins 3xTg-AD. A més, la cifosi és sensible a l'edat, canviant de postural a estructural en el procés d'envelliment. A més, el reflex d'enganxament indica la gravetat de la MA, una signatura primària com la cifosi. Inclou el fenotip de fragilitat que acompanya el deteriorament psicomotor general en ratolins i augmenta amb l'edat. D'altra banda, els patrons de comportament estranys que es van evidenciar en proves en sec i aigua van mostrar una major gravetat d'afectació entre els ratolins 3xTg-AD. A més, la neofòbia (congelació) altera el rendiment, especialment l'exploració i la locomoció. A més, els patrons estranys i la cifosi modifiquen el rendiment de la marxa espontània i l'activitat exploratòria, que es conserva en l'envelliment normal. Fins i tot les disfuncions secundàries es poden modular per factors externs, com ara l'aïllament i una nova prova de la bateria de comportament, on els ratolins 3xTg-AD milloren el rendiment motor en femelles i l'aïllament en els mascles. A més, la resistència física mesurada en rotarod era sensible al sexe, amb 3xTg-AD i les dones no transgèniques amb un millor rendiment. No obstant això, van mostrar els indicadors més alts de fragilitat, sarcopènia i alteració de l'eix HPA. Finalment, els deterioraments i alteracions funcionals en ratolins 3xTg-AD estan relacionats amb les etapes de la malaltia d'Alzheimer, proporcionant un escenari per entendre l'heterogeneïtat dels símptomes no cognitius del rendiment motor. La enfermedad de Alzheimer (EA) es un trastorno neurodegenerativo progresivo relacionado con la edad tradicionalmente descrito a través de sintomatología cognitiva y neuropsiquiátrica/conductual. Sin embargo, las disfunciones psicomotoras y el deterioro motor siguen estando poco explorados. El modelo 3xTg-AD muestra las alteraciones neuropatológicas y cognitivas que caracterizan la enfermedad de forma similar a lo que ocurre en humanos, presentando placas de β-amiloide en corteza e hipocampo a los 12 meses de edad repartidas por toda la corteza. Posteriormente, a los 15 meses, los ovillos de Tau intraneuronales acompañan a esta diseminación en la corteza cerebral. Esta investigación se basa en la Clasificación Internacional de Funcionamiento y Discapacidad, que se utiliza a nivel mundial en la rehabilitación de patologías neurodegenerativas, incluida la EA, y desde un enfoque de curso de vida asociado al envejecimiento normal, acelerado y patológico reproducible en diferentes contextos de investigación traslacional. Para el estudio de la EA se incluyeron dos fases de investigación. En la primera fase, se caracterizaron las firmas motoras primarias y secundarias de la disfunción psicomotora en el envejecimiento normal y la enfermedad de Alzheimer. En la fase 1 se incluyeron ratones machos 3xTg-AD y NTg de 6 y 12 meses de edad. En la segunda fase, las firmas primaria y secundaria fueron moduladas e integradas bajo la exploración de factores externos. Se incluyeron ratones machos 3xTg-AD y C57BL/6 de entre 13 y 16 meses de edad, y ratones machos y hembras 3xTg-AD y NTg de 12 y 16 meses de edad. Las pruebas psicomotoras evaluaron el rendimiento a partir de la marcha espontánea, la actividad exploratoria, la fuerza muscular y la resistencia física. Además, se incluyeron el fenotipo de fragilidad y fenotipos específicos como el reflejo de cierre y la geotaxis. Además, se realizaron estudios de sarcopenia y análisis del eje HPA. Por primera vez, los resultados informan la clasificación de las firmas primarias y secundarias de las disfunciones psicomotoras en el modelo de ratones 3xTg-AD. Se detectaron como firmas primarias presentes en la marcha y actividad exploratoria a partir del estudio de variables cuantitativas y cualitativas del desempeño psicomotor. Muestran una disminución de la longitud de la zancada, la velocidad y la cadencia, modificada por alteraciones posturales como la cifosis estructural en ratones 3xTg-AD. Además, la cifosis es sensible a la edad, cambiando de postural a estructural en el proceso de envejecimiento. Además, el reflejo de cierre indica la gravedad de la EA, una firma primaria como la cifosis. Incluye el fenotipo de fragilidad que acompaña al deterioro psicomotor general en ratones y aumenta con la edad. Por otro lado, los patrones de comportamiento extraños que se evidenciaron en las pruebas en seco y en agua mostraron una mayor severidad de afectación entre los ratones 3xTg-AD. Además, la neofobia (congelación) altera el rendimiento, particularmente la exploración y la locomoción. Además, los patrones extraños y la cifosis modifican el desempeño de la marcha espontánea y la actividad exploratoria, que se conserva en el envejecimiento normal. Incluso las disfunciones secundarias pueden ser moduladas por factores externos como el aislamiento y una nueva prueba de la batería de comportamiento, donde los ratones 3xTg-AD mejoran el rendimiento motor en las hembras y el aislamiento en los machos. Además, la resistencia física medida en rotarod fue sensible al sexo, con 3xTg-AD y las hembras no transgénicas rindiendo mejor. Sin embargo, mostraron los indicadores más altos de fragilidad, sarcopenia y alteración del eje HPA. Finalmente, los deterioros y alteraciones funcionales en ratones 3xTg-AD están relacionados con las etapas de la enfermedad de Alzheimer, proporcionando un escenario para comprender la heterogeneidad de los síntomas no cognitivos del desempeño motor. Alzheimer's disease (AD) is an age-related progressive neurodegenerative disorder traditionally described through cognitive and neuropsychiatric/behavioural symptomatology. However, psychomotor motor dysfunctions and motor impairment remain under-explored. The 3xTg-AD model shows the neuropathological and cognitive alterations that characterise the disease similar to what occurs in humans, presenting β-amyloid plaques in the cortex and hippocampus at 12 months of age spread throughout the cortex. Subsequently, at 15 months, intraneuronal Tau tangles accompany this spread in the cerebral cortex. This research is based on the International Classification of Functioning and Disability, which is used worldwide in the rehabilitation of neurodegenerative pathologies, including AD, and from a life course approach associated with normal, accelerated and pathological ageing reproducible in different translational research contexts. For the study of AD, two research phases were included. In the first phase, the primary and secondary motor signatures of psychomotor dysfunction in normal ageing and Alzheimer's disease were characterised. Male 3xTg-AD and NTg mice aged 6 and 12 months were included in phase 1. In the second phase, the primary and secondary signatures were modulated and integrated under the exploration of external factors. Male 3xTg-AD and C57BL/6 mice were included between 13 and 16 months of age, and male and female 3xTg-AD and NTg mice aged 12 and 16 months were also included. Psychomotor tests assessed performance from spontaneous gait, exploratory activity, muscle strength, and physical endurance. In addition, frailty phenotype and specific phenotypes such as clasping reflex and geotaxis were included. Additionally, sarcopenia studies and HPA axis analysis were performed. For the first time, the results report the classification of primary and secondary signatures of psychomotor dysfunctions in the 3xTg-AD mice model. They were detected as primary signatures present in gait and exploratory activity from the study of quantitative and qualitative variables of psychomotor performance. They show a decrease in stride length, speed and cadence, modified by postural alterations such as structural kyphosis in 3xTg-AD mice. In addition, kyphosis is age-sensitive, changing from postural to structural in the ageing process. Also, the clasping reflex indicates the severity of AD, a primary signature like kyphosis. It includes the frailty phenotype that accompanies general psychomotor impairment in mice and increases with age. On the other hand, bizarre behaviour patterns that were evidenced in dry and water tests showed greater severity of affectation among 3xTg-AD mice. In addition, neophobia (freezing) alters performance, particularly exploration and locomotion. Also, bizarre patterns and kyphosis modify the performance of spontaneous gait and exploratory activity, which is preserved in normal ageing. Even secondary dysfunctions can be modulated by external factors such as isolation and a re-test of the behavioural battery, where 3xTg-AD mice improve motor performance in females and isolation in males. Also, physical endurance measured in rotarod was sex-sensitive, with 3xTg-AD and non-transgenic females performing better. However, they showed the highest indicators of frailty, sarcopenia and alteration of the HPA axis. Finally, functional impairments and alterations in 3xTg-AD mice are related to Alzheimer's disease stages, providing a scenario to understand the heterogeneity of non-cognitive symptoms of motor performance.