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[Background] Previous studies suggest a link between CAG repeat number in the HTT gene and non-Huntington neurodegenerative diseases., [Objective] The aim is to analyze whether expanded HTT CAG alleles and/or their size are associated with the risk for developing α-synucleinopathies or their behavior as modulators of the phenotype., [Methods] We genotyped the HTT gene CAG repeat number and APOE-Ɛ isoforms in a case-control series including patients with either clinical or neuropathological diagnosis of α-synucleinopathy., [Results] We identified three Parkinson's disease (PD) patients (0.30%) and two healthy controls (0.19%) carrying low-penetrance HTT repeat expansions whereas none of the dementia with Lewy bodies (DLB) or multisystem atrophy (MSA) patients carried pathogenic HTT expansions. In addition, a clear increase in the number of HTT CAG repeats was found among DLB and PD groups influenced by the male gender and also by the APOE4 allele among DLB patients. HTT intermediate alleles' (IAs) distribution frequency increased in the MSA group compared with controls (8.8% vs. 3.9%, respectively). These differences were indeed statistically significant in the MSA group with neuropathological confirmation. Two MSA HTT CAG IAs carriers with 32 HTT CAG repeats showed isolated polyQ inclusions in pons and basal nuclei, which are two critical structures in the neurodegeneration of MSA., [Conclusions] Our results point to a link between HTT CAG number, HTT IAs, and expanded HTT CAG repeats with other non-HD brain pathology and support the hypothesis that they can share common neurodegenerative pathways., This work is supported by the Fondo de Investigaciones Sanitarias' Spanish government ICIII FIS-FEDER grants (ID grants: PI21/0467 to V.A., and PI21/00886 to P.P.). Sergio Pérez-Oliveira is supported by Fundación Parkinson Asturias-Obra Social Cajastur. M.T.P. was supported by the Spanish Ministry of Education, Culture and Sports [FPU16/05061]. D.M.-G. was supported by the “Río Hortega” program [CM18/00142] from the Instituto de Salud Carlos III (ISCIII-FEDER). P.G.-G. was supported by the “Nicolás Monardes” program [C-0048-2017] from the Andalusian Regional Ministry of Health. The Genome Research @ Fundació ACE project (GR@ACE) is supported by Grifols SA, Fundación bancaria “La Caixa,” Fundació ACE, and CIBERNED. P.G. is supported by CIBERNED employment plan CNV-304-PRF-866. A.R. and M.B. receive support from the European Union/EFPIA Innovative Medicines Initiative Joint undertaking ADAPTED and MOPEAD projects (grant numbers 115975 and 115985, respectively). M.B. and A.R. are also supported by National Grants (PI13/02434, PI16/01861, PI17/01474, PI19/01240, and PI19/01301). Acción Estratégica en Salud is integrated into the Spanish National R + D + I Plan and funded by ISCIII (Instituto de Salud Carlos III)—Subdirección General de Evaluación and the Fondo Europeo de Desarrollo Regional (FEDER—“Una manera de hacer Europa”).

Temporal lobe epilepsy (TLE) is the most common form of focal epilepsy and is associated with a variety of structural and psychological alterations. Recently, there has been renewed interest in using brain tissue resected during epilepsy surgery, in particular `non-epileptic¿ brain samples with normal histology that can be found alongside epileptic tissue in the same epileptic patients ¿ with the aim being to study the normal human brain organization using a variety of methods. An important limitation is that different medical characteristics of the patients may modify the brain tissue. Thus, to better determine how `normal¿ the resected tissue is, it is fundamental to know certain clinical, anatomical and psychological characteristics of the patients. Unfortunately, this information is frequently not fully available for the patient from which the resected tissue has been obtained ¿ or is not fully appreciated by the neuroscientists analyzing the brain samples, who are not necessarily experts in epilepsy. In order to present the full picture of TLE in a way that would be accessible to multiple communities (e.g., basic researchers in neuroscience, neurologists, neurosurgeons and psychologists), we have reviewed 34 TLE patients, who were selected due to the availability of detailed clinical, anatomical, and psychological information for each of the patients. Our aim was to convey the full complexity of the disorder, its putative anatomical substrates, and the wide range of individual variability, with a view toward: (1) emphasizing the importance of considering critical patient information when using brain samples for basic research and (2) gaining a better understanding of normal and abnormal brain functioning. In agreement with a large number of previous reports, this study (1) reinforces the notion of substantial individual variability among epileptic patients, and (2) highlights the common but overlooked psychopathological alterations that occur even in patients who become ¿seizure-free¿ after surgery. The first point is based on pre- and post-surgical comparisons of patients with hippocampal sclerosis and patients with normal-looking hippocampus in neuropsychological evaluations. The second emerges from our extensive battery of personality and projective tests, in a two-way comparison of these two types of patients with regard to pre- and post-surgical performance., This work was supported by grants from the following entities: Grant PID2021-127924NB-I00 funded by MCIN/AEI/10.13039/501100011033; Centro de Investigación en Red sobre Enfermedades Neurodegenerativas (CIBERNED, CB06/05/0066); and CSIC Interdisciplinary Thematic Platform (PTI) Cajal Blue Brain (PTI-BLUEBRAIN; Spain). RA was supported by ANDIA grant #0011-3947-2021-000023 from the Gobierno de Navarra.

Mitochondrial dysfunction happens in both idiopathic (iPD) and LRRK2-related Parkinson's disease (LRRK2-PD). Nonetheless, previous studies suggested that a different type of mitochondrial pathology underlies the neurodegeneration in these two disorders. To further explore this hypothesis, we developed a novel multiplex digital PCR assay that allows the absolute quantification of cell-free mitochondrial DNA (cf-mtDNA) copy number and deletion ratio directly in cerebrospinal fluid (CSF) by simultaneously measuring two opposed regions of the mtDNA circular molecule, one of them in the commonly deleted major arc. The results confirmed that the content of cf-mtDNA in CSF was statistically significantly different between iPD and LRRK2-PD patients. Moreover, we found high cf-mtDNA deletion levels in CSF from patients with iPD, but not LRRK2-PD. The high cf-mtDNA deletion frequency in iPD was validated in an independent cohort. These results indicated that the content and deletion ratio of cf-mtDNA may differentiate iPD from LRRK2-PD, and provides further evidence of the different mitochondrial pathophysiology between these two forms of the disease., Funded by The Michael J. Fox Foundation research grant MJFF-001111, by grants PID2020-115091RB-I00, MDM-2017-072, and PRE2018-083297 funded by MCIN/AEI/10.13039/501100011033 and by “ESF Investing in your future”, and grant PI2020/09-4 from CIBERNED, Institute of Health Carlos III. The LRRK2 Cohort Consortium (LCC) is coordinated and funded by The Michael J. Fox Foundation for Parkinson's Research. The investigators within the LCC contributed to the design and implementation of the LCC and/or provided data and/or collected biospecimens, but did not necessarily participate in the analysis or writing of this report. The full list of LCC investigators can be found at http://mjff.prod.acquia-sites.com/sites/default/files/media/document/LRRK2_Cohort_Consortium_Investigators_List.pdf.

[Significance]: The present study highlights a fundamental role of GABAergic interneuron-derived Reelin in neuronal migration, in addition to CR cell–expressed Reelin. Further, we observed transient migratory deficits, indicating that Reelin expressed by either neuronal population is sufficient to reverse some lamination defects. We propose a model of Reelin action in corticogenesis based on the spatial and cell-specific expression of this key protein. Because several neuropsychiatric disorders are linked to Reelin deficits in interneurons, this study may provide a better understanding of the mechanisms associated with human brain disorders related to Reelin deficits., The extracellular protein Reelin, expressed by Cajal–Retzius (CR) cells at early stages of cortical development and at late stages by GABAergic interneurons, regulates radial migration and the “inside-out” pattern of positioning. Current models of Reelin functions in corticogenesis focus on early CR cell–derived Reelin in layer I. However, developmental disorders linked to Reelin deficits, such as schizophrenia and autism, are related to GABAergic interneuron–derived Reelin, although its role in migration has not been established. Here we selectively inactivated the Reln gene in CR cells or GABAergic interneurons. We show that CR cells have a major role in the inside-out order of migration, while CR and GABAergic cells sequentially cooperate to prevent invasion of cortical neurons into layer I. Furthermore, GABAergic cell–derived Reelin compensates some features of the reeler phenotype and is needed for the fine tuning of the layer-specific distribution of cortical neurons. In the hippocampus, the inactivation of Reelin in CR cells causes dramatic alterations in the dentate gyrus and mild defects in the hippocampus proper. These findings lead to a model in which both CR and GABAergic cell–derived Reelin cooperate to build the inside-out order of corticogenesis, which might provide a better understanding of the mechanisms involved in the pathogenesis of neuropsychiatric disorders linked to abnormal migration and Reelin deficits., This work was supported by grants from the Spanish Ministerio de Ciencia y Competitividad and Ministerio de Ciencia e Innovación (SAF2016-76340R and PID2019-106764RB-C21, Excellence Unit 629, María de Maeztu/Institute of Neurosciences) and by Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (Instituto de Salud Carlos III, Spanish Ministry of Health) (to E.S.).

Póster presentado al Global Summit on Neurodegenerative Diseases NEURO 2020/2022 Salamanca, 21-24 de junio de 2022, The Vallecas Project is a cohort study of non-demented people aged 70-85 with the objective of characterize factors related to the appearance of cognitive impairment or dementia in the old. In this study, we have analyzed the exorne of a subgroup of participants, including cognitively normal individuals, mild cognitive impairment (MCI) and Alzheimer's disease (AD), to look for genetic variability related to the appearance of dementia. The variants identified were annotated using several bioiriformatics tools independently (SIFT, PolyPhen, CADO) but also with summarizing tools (REVEL, Varsome). After this, we filtered them by the frequency of the variant in the Caucasian population and by the variant's consequence. We analyzed the genetic results from three different perspectives. First, looking for incidéntal findings we were able to detect 3 variants in BTD, LDLR and CASQ2 in three individuals. Second, we explored the presence of genetic variability (MAF, CIBERNED-CIBERBBN joint Project (ISCIII)

Alzheimer’s disease is the most common form of dementia, characterized by a persistent and progressive impairment of cognitive functions. Alzheimer’s disease is typically associated with extracellular deposits of amyloid-β peptide and accumulation of abnormally phosphorylated tau protein inside neurons (amyloid-β and neurofibrillary pathologies). It has been proposed that these pathologies cause neuronal degeneration and synaptic alterations, which are thought to constitute the major neurobiological basis of cognitive dysfunction in Alzheimer’s disease. The hippocampal formation is especially vulnerable in the early stages of Alzheimer’s disease. However, the vast majority of electron microscopy studies have been performed in animal models. In the present study, we performed an extensive 3D study of the neuropil to investigate the synaptic organization in the stratum pyramidale and radiatum in the CA1 field of Alzheimer’s disease cases with different stages of the disease, using focused ion beam/scanning electron microscopy (FIB/SEM). In cases with early stages of Alzheimer’s disease, the synapse morphology looks normal and we observed no significant differences between control and Alzheimer’s disease cases regarding the synaptic density, the ratio of excitatory and inhibitory synapses, or the spatial distribution of synapses. However, differences in the distribution of postsynaptic targets and synaptic shapes were found. Furthermore, a lower proportion of larger excitatory synapses in both strata were found in Alzheimer’s disease cases. Individuals in late stages of the disease suffered the most severe synaptic alterations, including a decrease in synaptic density and morphological alterations of the remaining synapses. Since Alzheimer’s disease cases show cortical atrophy, our data indicate a reduction in the total number (but not the density) of synapses at early stages of the disease, with this reduction being much more accentuated in subjects with late stages of Alzheimer’s disease. The observed synaptic alterations may represent a structural basis for the progressive learning and memory dysfunctions seen in Alzheimer’s disease cases., Montero-Crespo et al. use electron microscopy to examine the 3D structure of the hippocampal CA1 subfield across different stages of Alzheimeŕs disease. Individuals in late disease stages show the most severe synaptic alterations, with reduced synaptic density and changes in the morphology of the remaining synapses.

Dopamine receptors play an important role in motivational, emotional, and motor responses. In addition, growing evidence suggests a key role of hippocampal dopamine receptors in learning and memory. It is well known that associative learning and synaptic plasticity of CA3-CA1 requires the dopamine D1 receptor (D1R). However, the specific role of the dopamine D2 receptor (D2R) on memory-related neuroplasticity processes is still undefined. Here, by using two models of D2R loss, D2R knockout mice (Drd2-/-) and mice with intrahippocampal injections of Drd2-small interfering RNA (Drd2-siRNA), we aimed to investigate how D2R is involved in learning and memory as well as in long-term potentiation of the hippocampus. Our studies revealed that the genetic inactivation of D2R impaired the spatial memory, associative learning, and the classical conditioning of eyelid responses. Similarly, deletion of D2R reduced the activity-dependent synaptic plasticity in the hippocampal CA1-CA3 synapse. Our results demonstrate the first direct evidence that D2R is essential in behaving mice for trace eye blink conditioning and associated changes in hippocampal synaptic strength. Taken together, these results indicate a key role of D2R in regulating hippocampal plasticity changes and, in consequence, acquisition and consolidation of spatial and associative forms of memory., Spanish Ministries of Science and Innovation (PID2019-111693RBI00, PCIN-2015-098); Ramón Areces Foundation (ref 172275); European Union’s Horizon 2020 research and innovation program, AND-PD (grant agreement no. 848002 to R.M., BFU2017- 82375-R to A.G. and J.M.D.-G.); Health, Social Services and Equality (PI2019/09-3), CIBERNED CB06/05/0055 to R.M.); the Spanish Junta de Andalucía (BIO-122, PY18FR_823 to A.G. and J.M.D.-G.).

The hippocampus plays a key role in contextual conditioning and has been proposed as an important component of the cocaine addiction brain circuit. To gain knowledge about cocaine-induced alterations in this circuit, we used focused ion beam milling/scanning electron microscopy to reveal and quantify the three-dimensional synaptic organization of the neuropil of the stratum radiatum of the rat CA1, under normal circumstances and after cocaine-self administration (SA). Most synapses are asymmetric (excitatory), macular-shaped, and in contact with dendritic spine heads. After cocaine-SA, the size and the complexity of the shape of both asymmetric and symmetric (inhibitory) synapses increased but no changes were observed in the synaptic density. This work constitutes the first detailed report on the 3D synaptic organization in the stratum radiatum of the CA1 field of cocaine-SA rats. Our data contribute to the elucidation of the normal and altered synaptic organization of the hippocampus, which is crucial for better understanding the neurobiological mechanisms underlying cocaine addiction., Ministerio de Ciencia e Innovación (PSI2016-80541-P to E.A.); Ministerio de Sanidad, Servicios Sociales e Igualdad (Red de Trastornos Adictivos [RTA-RD16/0017/0022 del Instituto de Salud Carlos III to E.A.] and Plan Nacional sobre Drogas [2016I073 to E.A.]); UNED (Plan de Promoción de la Investigación, 2014-040-UNED-POST to L.B.-L.); UNED-Banco Santander (“Independent Thinking”, 2017-VICE-0012 to L.B.- L.); European Union (JUST-2017-AG-DRUGS-806996-JUSTSO to E.A.); Centro de Investigación en Red sobre Enfermedades Neurodegenerativas (CIBERNED, CB06/05/0066 to J.D.); Ministerio de Ciencia, Innovación y Universidades (PGC2018-094307-B-I00 to J.D. and the Cajal Blue Brain Project [the Spanish partner of the Blue Brain Project initiative from EPFL, Switzerland] to J.D.); and Ministerio de Educación, Cultura y Deporte (contract FPU14/02245 to M.M.-C.).

Parkinson's disease (PD) is a progressive neurodegenerative disease where dopaminergic neurons in the substantia nigra are lost, resulting in a decrease in striatal dopamine and, consequently, motor control. Dopaminergic degeneration is associated with the appearance of Lewy bodies, which contain membrane structures and proteins, including α-synuclein (α-Syn), in surviving neurons. PD displays a multifactorial pathology and develops from interactions between multiple elements, such as age, environmental conditions, and genetics. Mutations in the GBA1 gene represent one of the major genetic risk factors for PD. This gene encodes an essential lysosomal enzyme called β-glucocerebrosidase (GCase), which is responsible for degrading the glycolipid glucocerebroside into glucose and ceramide. GCase can generate glucosylated cholesterol via transglucosylation and can also degrade the sterol glucoside. Although the molecular mechanisms that predispose an individual to neurodegeneration remain unknown, the role of cholesterol in PD pathology deserves consideration. Disturbed cellular cholesterol metabolism, as reflected by accumulation of lysosomal cholesterol in GBA1-associated PD cellular models, could contribute to changes in lipid rafts, which are necessary for synaptic localization and vesicle cycling and modulation of synaptic integrity. α-Syn has been implicated in the regulation of neuronal cholesterol, and cholesterol facilitates interactions between α-Syn oligomers. In this review, we integrate the results of previous studies and describe the cholesterol landscape in cellular homeostasis and neuronal function. We discuss its implication in α-Syn and Lewy body pathophysiological mechanisms underlying PD, focusing on the role of GCase and cholesterol. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society., This work was supported by grants from the Span-ish Ministries of Innovation, Science and Universities and Health, SocialServices and Equality and ISCIII, CIBERNED: PCIN2015-098,PID2019-111693RB-I00, CB06/05/0055, and PI2019/09-3; RamónAreces Foundation (172275); European Union’s Horizon 2020 researchand innovation program, AND-PD, grant agreement no. 848002 to R.M.;and NWO (grant no. BBOL-2007247202 to J.M.F.G.A.)

Alzheimer's disease (AD) is a major adult-onset neurodegenerative condition with no available treatment. Compelling reports point amyloid-β (Aβ) as the main etiologic agent that triggers AD. Although there is extensive evidence of detrimental crosstalk between Aβ and microglia that contributes to neuroinflammation in AD, the exact mechanism leading to neuron death remains unknown. Using postmortem human AD brain tissue, we show that Aβ pathology is associated with the necroptosis effector pMLKL. Moreover, we found that the burden of Aβ oligomers (Aβo) correlates with the expression of key markers of necroptosis activation. Additionally, inhibition of necroptosis by pharmacological or genetic means, reduce neurodegeneration and memory impairment triggered by Aβo in mice. Since microglial activation is emerging as a central driver for AD pathogenesis, we then tested the contribution of microglia to the mechanism of Aβo-mediated necroptosis activation in neurons. Using an in vitro model, we show that conditioned medium from Aβo-stimulated microglia elicited necroptosis in neurons through activation of TNF-α signaling, triggering extensive neurodegeneration. Notably, necroptosis inhibition provided significant neuronal protection. Together, these findings suggest that Aβo-mediated microglia stimulation in AD contributes to necroptosis activation in neurons and neurodegeneration. As necroptosis is a druggable degenerative mechanism, our findings might have important therapeutic implications to prevent the progression of AD., This study was funded by grants from FONDECYT No. 3180341 (to NS); FONDECYT No. 1190518 and FONDAP program 15150012 (to FC); Instituto de Salud Carlos III (ISCiii) of Spain, co-financed by FEDER funds from European Union, through grants PI18/01556 (to JV), PI21/00914 (to JV), PI18/01557 (to AG) and PI21/00915 (to AG), CIBERNED (to JV and AG) and by Junta de Andalucia Consejería de Economía y Conocimiento co-financed by FEDER 2014-2020 through grants US-1262734 (JV), UMA18-FEDERJA-211 (AG), UMA20-FEDERJA-104 (I-MG) and P18-RT-2233 (to AG). Ministry of Science and Innovation (MICIN) State Research Agency grants PID2019-107090RA-I00 and Ramon y Cajal Program RYC-2017-21879 (to IMG) and grants from NIH R01AG059321 and R01AG061069 (to CS).

Abnormalities in myelination are associated to behavioral and cognitive dysfunction in neurodevelopmental psychiatric disorders. Thus, therapies to promote or accelerate myelination could potentially ameliorate symptoms in autism. Clemastine, a histamine H1 antagonist with anticholinergic properties against muscarinic M1 receptor, is the most promising drug with promyelinating properties. Clemastine penetrates the blood brain barrier efficiently and promotes remyelination in different animal models of neurodegeneration including multiple sclerosis, ischemia and Alzheimer’s disease. However, its role in myelination during development is unknown. We showed that clemastine treatment during development increased oligodendrocyte differentiation in both white and gray matter. However, despite the increase in the number of oligodendrocytes, conduction velocity of myelinated fibers of corpus callosum decreased in clemastine treated mice. Confocal and electron microscopy showed a reduction in the number of myelinated axons and nodes of Ranvier and a reduction of myelin thickness in corpus callosum. To understand the mechanisms leading to myelin formation impairment in the presence of an excess of myelinating oligodendrocytes, we focused on microglial cells that also express muscarinic M1 receptors. Importantly, the population of CD11c+ microglia cells, necessary for myelination, as well as the levels of insulin growth factor-1 decrease in clemastine-treated mice. Altogether, these data suggest that clemastine impact on myelin development is more complex than previously thought and could be dependent on microglia-oligodendrocyte crosstalk. Further studies are needed to clarify the role of microglia cells on developmental myelination., This work was supported by Spanish Ministry of Education and Science (SAF 2016-75292- R); Spanish Ministry of Science and Innovation (PID 2019-109724RB-I00); Basque Government (PI-2016-1-0016); the University of the Basque Country (UPV/EHU); and Centro de Investigación Biomédica en Red, Enfermedades Neurodegenerativas (CIBERNED; grant CB06/05/0076). AP has a predoctoral fellowship from the University of the Basque Country (UPV/EHU), AM has a predoctoral fellowship from the Spanish Ministry of Education and Science and AO-de-A has a postdoctoral fellowship from the Basque Government.

Hepatocellular carcinoma (HCC), the most common form of liver cancer, continues to be a serious medical problem with poor prognosis, without major therapeutic improvement for years and increasing incidence. Fortunately, advances in systemic treatment options are finally arriving for HCC patients. After a decade of sorafenib as a standard therapy for advanced HCC, several tyrosine kinase inhibitors (TKIs), antiangiogenic antibodies, and immune checkpoint inhibitors have reached the clinic. Although infections by hepatitis B virus and hepatitis C virus remain principal factors for HCC development, the rise of non-alcoholic steatohepatitis from diabetes mellitus or metabolic syndrome is impeding HCC decline. Knowledge of specific molecular mechanisms, based on the etiology and the HCC microenvironment that influence tumor growth and immune control, will be crucial for physician decision-making among a variety of drugs to prescribe. In addition, markers of treatment efficacy are needed to speed the movement of patients towards other potentially effective treatments. Consequently, research to provide scientific data for the evidence-based management of liver cancer is guaranteed in the coming years and discussed here. This research was funded by Instituto de Salud Carlos III, grant number PI19/01410 to M.M.; CIBEREHD and CIBERNED; Ministerio de Ciencia e Innovación, grant numbers RTI2018- 095672-B-I00 to A.M. and P.G.F. and RTI2018-095572-B-100 to A.C.; and co-funded by FEDER (Fondo Europeo de Desarrollo Regional, Unión Europea); Ayuda Extraordinaria CSIC 2021AEP095 to A.M. and P.G.F., AGAUR, grant number 2017_SGR_177 to A.M.; Fundació la Marató de TV3 to A.M.; and CERCA Programme/Generalitat de Catalunya.

Early View: Online Version of Record before inclusion in an issue., In Alzheimer's disease (AD), the enzyme acetylcholinesterase (AChE) co‐localizes with hyperphosphorylated tau (P‐tau) within neurofibrillary tangles. Having demonstrated that AChE expression is increased in the transgenic mouse model of tau Tg‐VLW, here we examined whether modulating phosphorylated tau levels by over‐expressing wild‐type human tau and glycogen synthase kinase‐3β (GSK3β) influences AChE expression. In SH‐SY5Y neuroblastoma cells expressing higher levels of P‐tau, AChE activity and protein increased by (20% ± 2%) and (440% ± 150%), respectively. Western blots and qPCR assays showed that this increment mostly corresponded to the cholinergic ACHE‐T variant, for which the protein and transcript levels increased ~60% and ~23%, respectively. Moreover, in SH‐SY5Y cells differentiated into neurons by exposure to retinoic acid (10 µM), over‐expression of GSK3β and tau provokes an imbalance in cholinergic activity with a decrease in the neurotransmitter acetylcholine in the cell (45 ± 10%). Finally, we obtained cerebrospinal fluid (CSF) from AD patients enrolled on a clinical trial of tideglusib, an irreversible GSK3β inhibitor. In CSF of patients that received a placebo, there was an increase in AChE activity (35 ± 16%) respect to basal levels, probably because of their treatment with AChE inhibitors. However, this increase was not observed in tideglusib‐treated patients. Moreover, CSF levels of P‐tau at the beginning measured by commercially ELISA kits correlated with AChE activity. In conclusion, this study shows that P‐tau can modulate AChE expression and it suggests that AChE may possibly increase in the initial phases of AD., MACG is supported by a GVA-Predoctoral fellowship from Generalitat Valenciana, Spain. This study was funded by Instituto de Salud Carlos III (ISCIII), Fondo de Investigaciones Sanitaria (grants CP11/00067 and PI17/00261 to MSGA); co-financed by Fondo Europeo de Desarrollo Regional and through CIBERNED, ISCIII, Spain.

[Introduction] Limited information is available on people’s experiences of living with Alzheimer’s disease (AD) at earlier stages. This study assessed awareness of diagnosis among people with early-stage AD and its impact on different person-centered outcome measures., [Methods] We conducted an observational, cross-sectional study in 21 memory clinics in Spain. Persons aged 50–90 years, diagnosed with prodromal or mild AD (NIA/AA criteria), a Mini Mental State Examination (MMSE) score ≥ 22, and a Clinical Dementia Rating-Global score (CDR-GS) of 0.5 or 1.0 were recruited. The Representations and Adjustment to Dementia Index (RADIX) was used to assess participants’ beliefs about their condition and its consequences., [Results] A total of 149 persons with early-stage AD were studied. Mean (SD) age was 72.3 (7.0) years and 50.3% were female. Mean duration of AD was 1.4 (1.8) years. Mean MMSE score was 24.6 (2.1) and 87.2% had a CDR-GS score of 0.5. Most participants (n = 84, 57.5%) used a descriptive term related to specific AD symptoms (e.g., memory difficulties) when asked what they called their condition. Participants aware of their diagnosis using the term AD (n = 66, 45.2%) were younger, had more depressive symptoms, and poorer life satisfaction and quality of life compared to those without awareness of their specific diagnosis. Practical and emotional consequences RADIX scores showed a significant negative correlation with Quality of Life in Alzheimer’s Disease score (rho = − 0.389 and − 0.413, respectively; p, [Conclusions] Awareness of diagnosis was a common phenomenon in persons with early-stage AD negatively impacting their quality of life. Understanding illness representations in earlier stages may facilitate implementing optimized care that supports improved quality of life and well-being., This study was funded by the Medical Department of Roche Farma Spain (ML42346); funding sources with Life Molecular Imaging, Bioiberica, and Schwabe; and grants from CIBERNED, EU/EFPIA, Instituto de Salud Carlos III (ISCIII), Fundación La Caixa, and Grífols.

Synaptic impairment might precede neuronal degeneration in Parkinson’s disease. However, the intimate mechanisms altering synaptic function by the accumulation of presynaptic α-synuclein in striatal dopaminergic terminals before dopaminergic death occurs, have not been elucidated. Our aim is to unravel the sequence of synaptic functional and structural changes preceding symptomatic dopaminergic cell death. As such, we evaluated the temporal sequence of functional and structural changes at striatal synapses before parkinsonian motor features appear in a rat model of progressive dopaminergic death induced by overexpression of the human mutated A53T α-synuclein in the substantia nigra pars compacta, a protein transported to these synapses. Sequential window acquisition of all theoretical mass spectra proteomics identified deregulated proteins involved first in energy metabolism and later, in vesicle cycling and autophagy. After protein deregulation and when α-synuclein accumulated at striatal synapses, alterations to mitochondrial bioenergetics were observed using a Seahorse XF96 analyser. Sustained dysfunctional mitochondrial bioenergetics was followed by a decrease in the number of dopaminergic terminals, morphological and ultrastructural alterations, and an abnormal accumulation of autophagic/endocytic vesicles inside the remaining dopaminergic fibres was evident by electron microscopy. The total mitochondrial population remained unchanged whereas the number of ultrastructurally damaged mitochondria increases as the pathological process evolved. We also observed ultrastructural signs of plasticity within glutamatergic synapses before the expression of motor abnormalities, such as a reduction in axospinous synapses and an increase in perforated postsynaptic densities. Overall, we found that a synaptic energetic failure and accumulation of dysfunctional organelles occur sequentially at the dopaminergic terminals as the earliest events preceding structural changes and cell death. We also identify key proteins involved in these earliest functional abnormalities that may be modulated and serve as therapeutic targets to counterbalance the degeneration of dopaminergic cells to delay or prevent the development of Parkinson’s disease., This study was funded by the Instituto de Salud Carlos III through the projects PI14/00763 and PI19/01915 (co-funded by ERDF/ESF, ‘Investing in your future’). L.M.-G. held a Predoctoral Research Fellowship from the University of the Basque Country (UPV/EHU). T.R.-C. and A.Q.-V. were funded by CIBERNED. T.R.-C. held a Fundación Jesús de Gangoiti Barrera Foundation grant (Bilbao, Spain). H.J.-U. and A.B.-I. held a Predoctoral Research Fellowship from the Government of the Basque Country. Israel Science Foundation (536/19) and the Spanish Ministry of Science (SAF2016-78071-R) funded the contribution of S.K. and A.O.

Mice with insulin receptor (IR)-deficient astrocytes (GFAP-IR knockout [KO] mice) show blunted responses to insulin and reduced brain glucose uptake, whereas IRdeficient astrocytes show disturbed mitochondrial responses to glucose. While exploring the functional impact of disturbed mitochondrial function in astrocytes, we observed that GFAP-IR KO mice show uncoupling of brain blood flow with glucose uptake. Since IR-deficient astrocytes show higher levels of reactive oxidant species (ROS), this leads to stimulation of hypoxia-inducible factor-1¿ and, consequently, of the vascular endothelial growth factor angiogenic pathway. Indeed, GFAP-IR KO mice show disturbed brain vascularity and blood flow that is normalized by treatment with the antioxidant N-acetylcysteine (NAC). NAC ameliorated high ROS levels, normalized angiogenic signaling and mitochondrial function in IR-deficient astrocytes, and normalized neurovascular coupling in GFAP-IR KO mice. Our results indicate that by modulating glucose uptake and angiogenesis, insulin receptors in astrocytes participate in neurovascular coupling., We are thankful to M.Garcia and R. Cañadas for technical support. This work was funded by Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED) (Instituto de Salud CarlosIII, Spain) to I.T.A., A.G., and T.I.; an Inter-CIBER project (PIE14/00061) to I.T.A.that forms part of the projects PID2019-104376RB-I00 (I.T.A.) and RTI2018-094887-B-I00 (M.N.) funded by MCIN/AEI/10.13039/501100011033; a grant from Junta de Andalucia Consejería de Economía y Conocimiento (P18-RT-2233 to A.G.) cofinanced by Programa Operativo FEDER 2014–2020; a grant from Instituto de Salud Carlos III Spain (cofinanced by FEDER funds from the European Union; PI21/00915 to A.G.); Grant PID2020-115218RB-I00 to T.I. funded by Ministerio de Ciencia e Innovación/Agencia Española de Investigación (MCIN/AEI/10.13039/501100011033); and a grant from Comunidad de Madrid through the European Social Fund (ESF)–financed programme Neurometabolismo-Comunidad de Madrid (NEUROMETAB-CM) (B2017/BMD-3700 to I.T.A.and T.I.). M.N. was also supported by the Spanish Ministry of Science and Innovation (Ramón y Cajal RYC-2016-20414). J.P.-U. was contracted by CIBERNED.

Background: Both idiopathic and familial Parkinson's disease are associated with mitochondrial dysfunction. Mitochondria have their own mitochondrial DNA (mtDNA) and previous studies have reported that the release of mtDNA is a biomarker of Parkinson's disease. Methods: We have now investigated the relationship between mtDNA replication, transcription and release in fibroblasts from patients with idiopathic (iPD) and Leucine-rich repeat kinase 2 -associated Parkinson's disease (LRRK2-PD), using Selfie-digital PCR, a method that allows absolute quantification of mtDNA genomes and transcripts. Findings: In comparison with healthy controls, we found that fibroblasts from patients with iPD or LRRK2-PD had a high amount of mitochondrial 7S DNA along with a low mtDNA replication rate that was associated with a reduction of cf-mtDNA release. Accumulation of 7S DNA in iPD and LRRK2-PD fibroblasts was related with an increase in H-strand mtDNA transcription. Interpretation: These results show that 7S DNA accumulation, low mtDNA replication, high H-strand transcription, and low mtDNA release compose a pattern of mtDNA dysfunction shared by both iPD and LRRK2-PD fibroblasts. Moreover, these results suggest that the deregulation of the genetic switch formed by 7SDNA that alternates between mtDNA replication and transcription is a fundamental pathophysiological mechanism in both idiopathic and monogenic Parkinson's disease., This work was supported by grants to Ramon Trullas and Petar Podlesniy from the Ministerio de Ciencia, Innovación y Universidades of Spain (Grant: SAF2017-89791-R) and from the Instituto Carlos III, Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas, CIBERNED (Grant: PI2016/06-3).

Donor derived regulatory T lymphocytes and the JAK1/2 kinase inhibitor ruxolitinib are currently being evaluated as therapeutic options in the treatment of chronic graft versus host disease (cGvHD). In this work, we aimed to determine if the combined use of both agents can exert a synergistic effect in the treatment of GvHD. For this purpose, we studied the effect of this combination both in vitro and in a GvHD mouse model. Our results show that ruxolitinib favors the ratio of thymic regulatory T cells to conventional T cells in culture, without affecting the suppressive capacity of these Treg. The combination of ruxolitinib with Treg showed a higher efficacy as compared to each single treatment alone in our GvHD mouse model in terms of GvHD incidence, severity and survival without hampering graft versus leukemia effect. This beneficial effect correlated with the detection in the bone marrow of recipient mice of the infused donor allogeneic Treg after the adoptive transfer., This work was supported by grants from Novartis and the Andalusian Regional Government (P18-RT-4047, PI-0052-2018). A.R.G. and J.A.P.S. are members of CIBERONC (CB16/12/00480) and TerCel (16/0011/0035). J.V. is member of CIBERNED (CB06/05/0027). A.R.G. is funded by a Grant of the University of Seville (US-1380874) co-funded by the European Regional Development Fund (ERDF). This study is partially funded by Novartis.

Emerging studies have suggested several chromosomal regions as potential host genetic factors involved in the susceptibility to SARS-CoV-2 infection and disease outcome. We nested a COVID-19 genome-wide association study using the GR@ACE/DEGESCO study, searching for susceptibility factors associated with COVID-19 disease. To this end, we compared 221 COVID-19 confirmed cases with 17,035 individuals in whom the COVID-19 disease status was unknown. Then, we performed a meta-analysis with the publicly available data from the COVID-19 Host Genetics Initiative. Because the APOE locus has been suggested as a potential modifier of COVID-19 disease, we added sensitivity analyses stratifying by dementia status or by disease severity. We confirmed the existence of the 3p21.31 region (LZTFL1, SLC6A20) implicated in the susceptibility to SARS-CoV-2 infection and TYK2 gene might be involved in COVID-19 severity. Nevertheless, no statistically significant association was observed in the COVID-19 fatal outcome or in the stratified analyses (dementia-only and non-dementia strata) for the APOE locus not supporting its involvement in SARS-CoV-2 pathobiology or COVID-19 prognosis., We would like to thank patients and controls who participated in this project. The present work has been performed as part of the doctoral program of I. de Rojas at the Universitat de Barcelona (Barcelona, Spain) supported by national grant from the Instituto de Salud Carlos III FI20/00215. The Genome Research @ Fundació ACE project (GR@ACE) is supported by Grifols SA, Fundación bancaria ‘La Caixa’, Fundació ACE, and CIBERNED. The Vallecas Project is supported by Queen Sofia Foundation and the Instituto de Salud Carlos III. The position held by SA-L is funded by Instituto de Salud Carlos III (Co-funded by European Social Fund “Investing in your future”) Sara Borrell Contract (CD19/00232). A.R. and M.B. receive support from the European Union/EFPIA Innovative Medicines Initiative Joint undertaking ADAPTED and MOPEAD projects (grant numbers 115975 and 115985, respectively). M.B. and A.R. are also supported by national grants PI13/02434, PI16/01861, PI17/01474, PI19/01240 and PI19/01301. Acción Estratégica en Salud is integrated into the Spanish National R + D + I Plan and funded by ISCIII (Instituto de Salud Carlos III)–Subdirección General de Evaluación and the Fondo Europeo de Desarrollo Regional (FEDER–‘Una manera de hacer Europa’). Some control samples and data from patients included in this study were provided in part by the National DNA Bank Carlos III (www.bancoadn.org, accessed date: 1 October 2021, University of Salamanca, Spain) and Hospital Universitario Virgen de Valme (Sevilla, Spain); they were processed following standard operating procedures with the appropriate approval of the Ethical and Scientific Committee. This research has been conducted using the COVID-19 Host Genetic Initiative public resource obtained through the web site (https://www.covid19hg.org/results/, accessed date: 1 October 2021).

La realización de esta Tesis Doctoral ha sido posible gracias al disfrute de un contrato Predoctoral de Personal Investigador en Formación financiado por los proyectos SAF2014-52737-P (2017-2018) y SAF2017-88885-R (2018-2020), vinculados al Consejo Superior de Investigaciones Científicas (CSIC), así como un contrato de Titulado Superior de Actividades Técnicas y Profesionales financiado por el Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED) (2020-2021)

[Background] Atrial fibrillation (AF) has been associated with an increased risk of silent brain infarcts (SBI) and cognitive impairment, even in patients with low embolic risk. We aimed to test the association between 11 blood-biomarkers representing different AF-related pathways, and SBI, white matter hyperintensities (WMH), and cognitive decline in patients with AF and low embolic risk., [Methods] The present study followed a cross-sectional design. 70 patients with a history of AF and CHADS2 score ≤1, and 10 controls with neither AF nor SBI were included. All patients underwent a 3T brain MRI. Cortical and large subcortical ischemic lesions were considered presumed embolic origin lesions. White matter hyperintensities (WMH) were measured according to the Fazekas scale. A subset of patients underwent cognitive evaluation with the MoCA test. Circulating proteins were measured under blind conditions in a laboratory at Roche Diagnostics, Germany., [Results] 45 patients presented SBI in the MRI, and 25 did not. Ang-2, FGF-23, and BMP-10 were increased in patients with SBI. Ang-2 was elevated only in patients with embolic infarcts, whereas FGF-23 and BMP-10 tended to be elevated in patients with both types of infarcts. Ang-2 (OR = 1.56 [0.94-2.59], p = 0.087), and BMP-10 (OR = 4.83 [0.99–23.60], p = 0.052) were the biomarkers that showed the highest association with SBI when entered in a multivariable logistic regression model corrected by age. No biomarker was found associated with WMH or mild cognitive impairment., [Conclusions] BMP-10, and Ang-2 were increased in patients with SBI. Its usefulness to detect SBI in AF patients should be further explored., A Junta de Andalucía grant (PIN-0144-2016) supported partially the study. The Fundación Cajasol contributed to the study. Neurovascular Research Groups at Seville and Barcelona are part of the Spanish Neurovascular Disease Research Network (RICORS-ICTUS, RD21/0006/0007).

Huntington’s disease (HD) is a hereditary neurodegenerative disorder of the basal ganglia for which disease-modifying treatments are not yet available. Although gene-silencing therapies are currently being tested, further molecular mechanisms must be explored to identify druggable targets for HD. Cytoplasmic polyadenylation element binding proteins 1 to 4 (CPEB1 to CPEB4) are RNA binding proteins that repress or activate translation of CPE-containing transcripts by shortening or elongating their poly(A) tail. Here, we found increased CPEB1 and decreased CPEB4 protein in the striatum of patients and mouse models with HD. This correlated with a reprogramming of polyadenylation in 17.3% of the transcriptome, markedly affecting neurodegeneration-associated genes including PSEN1, MAPT, SNCA, LRRK2, PINK1, DJ1, SOD1, TARDBP, FUS, and HTT and suggesting a new molecular mechanism in neurodegenerative disease etiology. We found decreased protein content of top deadenylated transcripts, including striatal atrophy–linked genes not previously related to HD, such as KTN1 and the easily druggable SLC19A3 (the ThTr2 thiamine transporter). Mutations in SLC19A3 cause biotin-thiamine–responsive basal ganglia disease (BTBGD), a striatal disorder that can be treated with a combination of biotin and thiamine. Similar to patients with BTBGD, patients with HD demonstrated decreased thiamine in the cerebrospinal fluid. Furthermore, patients and mice with HD showed decreased striatal concentrations of thiamine pyrophosphate (TPP), the metabolically active form of thiamine. High-dose biotin and thiamine treatment prevented TPP deficiency in HD mice and attenuated the radiological, neuropathological, and motor HD-like phenotypes, revealing an easily implementable therapy that might benefit patients with HD., This work was supported by CIBERNED-ISCIII collaborative grants 2013/09-2 to J.J.L. and 2015-2/06 and 2018/06-5 to J.J.L. and T.I., grants SAF2015-65371-R (MINECO/AEI/FEDER, UE), and grants from the Spanish Ministry of Science, Innovation and Universities (MINECO/MICINN): RTI2018-096322-B-I00 (MCIU/AEI/FEDER, UE) to J.J.L., SAF2017-88885-R (MINECO/AEI/FEDER, UE) to T.I., BFU2014-54122-P (MINECO/AEI/FEDER, UE) to R.M., and ISCIII-FEDER (PI17/00199; PI20/00625) to P.N. This work was also supported by the European Union FEDER funds, Fundación Botín–Banco Santander through its Santander Universities Global Division and Fundación Ramón Areces. A.P. and S.P. were recipients of FPI fellowships from MICINN/MINECO. A.P. was also hired through CIBERNED. J.P.-U. was contracted by SAF2017-88885-R (MINECO/AEI/FEDER, UE). D.M.-G. was supported by the “Río Hortega” programme (CM18/00142) from ISCIII-FEDER. A.E. was a recipient of Juan de la Cierva contracts from MICINN/MINECO.

Sorafenib and regorafenib, multikinase inhibitors (MKIs) used as standard chemotherapeutic agents for hepatocellular carcinoma (HCC), generate reactive oxygen species (ROS) during cancer treatment. Antioxidant supplements are becoming popular additions to our diet, particularly glutathione derivatives and mitochondrial-directed compounds. To address their possible interference during HCC chemotherapy, we analyzed the effect of common antioxidants using hepatoma cell lines and tumor spheroids. In liver cancer cell lines, sorafenib and regorafenib induced mitochondrial ROS production and potent cell death after glutathione depletion. In contrast, cabozantinib only exhibited oxidative cell death in specific HCC cell lines. After sorafenib and regorafenib administration, antioxidants such as glutathione methyl ester and the superoxide scavenger MnTBAP decreased cell death and ROS production, precluding the MKI activity against hepatoma cells. Interestingly, sorafenib-induced mitochondrial damage caused PINK/Parkin-dependent mitophagy stimulation, altered by increased ROS production. Finally, in sorafenib-treated tumor spheroids, while ROS induction reduced tumor growth, antioxidant treatments favored tumor development. In conclusion, the anti-tumor activity of specific MKIs, such as regorafenib and sorafenib, is altered by the cellular redox status, suggesting that uncontrolled antioxidant intake during HCC treatment should be avoided or only endorsed to diminish chemotherapy-induced side effects, always under medical scrutiny., Study funded by grants from Instituto de Salud Carlos III (PI19/01410 to M.M., and PI19/00358 to M.R.), CIBEREHD and CIBERNED; Ministerio de Ciencia, Innovación y Universidades (RTI2018-095672-B-I00 to A.M. and P.G.F., and RTI2018-095572-B-100 to A.C.) and co-funded by FEDER (Fondo Europeo de Desarrollo Regional, Unión Europea); AGAUR (2017_SGR_177 to A.M.) and CERCA Programme/Generalitat de Catalunya

An experimental model of spinal root avulsion (RA) is useful to study causal molecular programs that drive retrograde neurodegeneration after neuron-target disconnection. This neurode-generative process shares common characteristics with neuronal disease-related processes such as the presence of endoplasmic reticulum (ER) stress and autophagy flux blockage. We previously found that the overexpression of GRP78 promoted motoneuronal neuroprotection after RA. After that, we aimed to unravel the underlying mechanism by carrying out a comparative unbiased proteomic analysis and pharmacological and genetic interventions. Unexpectedly, mitochondrial factors turned out to be most altered when GRP78 was overexpressed, and the abundance of engulfed mitochondria, a hallmark of mitophagy, was also observed by electronic microscopy in RA-injured motoneurons after GRP78 overexpression. In addition, GRP78 overexpression increased LC3-mitochondria tag-ging, promoted PINK1 translocation, mitophagy induction, and recovered mitochondrial function in ER-stressed cells. Lastly, we found that GRP78-promoted pro-survival mitophagy was mediated by PINK1 and IP3R in our in vitro model of motoneuronal death. This data indicates a novel relationship between the GRP78 chaperone and mitophagy, opening novel therapeutical options for drug design to achieve neuroprotection., This work was mainly supported by the Ministerio de Economía y Competitividad of Spain (#SAF 2014-59701) and by the Marató de TV3 (#201607.10). We are also grateful for support from CIBERNED and Generalitat de Catalunya fundings. CB is a recipient of Miguel Servet contract (CP19/00077) from Carlos III Health Institute.

The axon initial segment (AIS) is a region of the neuron that is critical for action potential generation as well as for the regulation of neural activity. This specialized structure—characterized by the expression of different types of ion channels as well as adhesion, scaffolding and cytoskeleton proteins—is subjected to morpho-functional plastic changes in length and position upon variations in neural activity or in pathological conditions. In the present study, using immunocytochemistry with the AT8 antibody (phospho-tau S202/T205) and 3D confocal microscopy reconstruction techniques in brain tissue from Alzheimer’s disease patients, we found that around half of the cortical pyramidal neurons with hyperphosphorylated tau showed changes in AIS length and position in comparison with AT8-negative neurons from the same cortical layers. We observed a wide variety of AIS alterations in neurons with hyperphosphorylated tau, although the most common changes were a proximal shift or a lengthening of the AISs. Similar results were found in neocortical tissue from non-demented cases with neurons containing hyperphosphorylated tau. These findings support the notion that the accumulation of phospho-tau is associated with structural alterations of the AIS that are likely to have an impact on normal neuronal activity, which might contribute to neuronal dysfunction in AD., This work was supported by grants from the following entities: PGC2018-094307-B-I00 from the Spanish “Ministerio de Ciencia e Innovación”; Centro de Investigación en Red sobre Enfermedades Neurodegenerativas (CIBERNED, CB06/05/0066, Spain); Interdisciplinary Platform Cajal Blue Brain (CSIC, Spain); and a grant from the Alzheimer’s Association (ZEN-15-321663).

Cannabinoids, the bioactive constituents of cannabis, exert a wide array of effects on the brain by engaging Type 1 cannabinoid receptor (CB1R). Accruing evidence supports that cannabinoid action relies on context-dependent factors, such as the biological characteristics of the target cell, suggesting that cell population-intrinsic molecular cues modulate CB1R-dependent signaling. Here, by using a yeast two-hybrid-based high-throughput screening, we identified BiP as a potential CB1R-interacting protein. We next found that CB1R and BiP interact specifically in vitro, and mapped the interaction site within the CB1R C-terminal (intracellular) domain and the BiP C-terminal (substrate-binding) domain-a. BiP selectively shaped agonist-evoked CB1R signaling by blocking an "alternative" Gq/11 protein-dependent signaling module while leaving the "classical" Gi/o protein-dependent inhibition of the cAMP pathway unaffected. In situ proximity ligation assays conducted on brain samples from various genetic mouse models of conditional loss or gain of CB1R expression allowed to map CB1R-BiP complexes selectively on terminals of GABAergic neurons. Behavioral studies using cannabinoid- treated male BiP1/2 mice supported that CB1R-BiP complexes modulate cannabinoid-evoked anxiety, one of the most frequent undesired effects of cannabis. Together, by identifying BiP as a CB1R-interacting protein that controls receptor function in a signaling pathway- and neuron population-selective manner, our findings may help to understand the striking context-dependent actions of cannabis in the brain., This work was supported by Spanish Ministerio de Ciencia e Innovación Grants RTI2018-095311-B-I00 to M.G., SAF-2017-87629-R to E.I.C. and V.C., PID2019-106404RB-I00 to L.U., BFU 2017-83292-R to J.S.-P., and RTI2018-094374-B-I00 to S.G.; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas Grant PI2018/01 to M.G., S.G., and G. Mengod; and UK Research and Innovation Biotechnology and Biological Sciences Research Council Grant BB/R006946/1 to P.J.M., L.B., and G. Marsicano were supported by Institut National de la Santé et de la Recherche Médicale. C.C.-I. and I.B.M. were supported by contracts from Spanish Ministerio de Universidades (Formación de Profesorado Universitario Program, references FPU16/02593 and FPU15/01833, respectively). R.B.-G. was supported by a contract from Spanish Ministerio de Ciencia e Innovación Juan de la Cierva Program.

18 p.-8 fig.-1 tab., Limb-girdle muscular dystrophy R1 calpain 3-related (LGMDR1) is an autosomal recessive muscular dystrophy produced by mutations in the CAPN3 gene. It is a rare disease and there is no cure or treatment for the disease while the pathophysiological mechanism by which the absence of calpain 3 provokes the dystrophy in muscles is not clear. However, key proteins implicated in Wnt and mTOR signaling pathways, which regulate muscle homeostasis, showed a considerable reduction in their expression and in their phosphorylation in LGMDR1 patients’ muscles. Finally, the administration of tideglusib and VP0.7, ATP non-competitive inhibitors of glycogen synthase kinase 3β (GSK-3β), restore the expression and phosphorylation of these proteins in LGMDR1 cells, opening the possibility of their use as therapeutic options, This work was financed through the grants received from the Health Research Fund (PI16/01325, PI17/01841 and DTS19/00061) of the Spanish Ministry of Economy and Competitiveness and the European Union (ERDF) and it was in part supported by the Center for Networked Biomedical Research on Neurodegenerative Diseases (CIBERNED: CB06/05/1126 to A.R., G.G., A.V., L.C.-F., A.L.d.M. and A.S. and CB18/05/00040 to A.M. and V.P.), Carlos III Health Institute and by GENE (Association of Neuromuscular diseases of Gipuzkoa). A.R. was supported by the predoctoral fellowship given by the department of Education, Universities and Research of the Basque Government (PRE-2016-1-0382).

The disaccharide trehalose was described as possessing relevant neuroprotective properties as an mTORC1-independent inducer of autophagy, with the ability to protect cellular membranes and denaturation, resulting from desiccation, and preventing the cellular accumulation of protein aggregates. These properties make trehalose an interesting therapeutic candidate against proteinopathies such as Alzheimer’s disease (AD), which is characterized by deposits of aggregated amyloid-beta (Aβ) and hyperphosphorylated tau. In this study, we observed that trehalose was able to induce autophagy in neurons only in the short-term, whereas long-term treatment with trehalose provoked a relevant anti-amyloidogenic effect in neurons from an AD mouse model that was not mediated by autophagy. Trehalose treatment reduced secreted Aβ levels in a manner unrelated to its intracellular accumulation or its elimination through endocytosis or enzymatic degradation. Moreover, the levels of Aβ precursor protein (APP) and beta-secretase (BACE1) remained unal-tered, as well as the proper acidic condition of the endo-lysosome system. Instead, our results support that the neuroprotective effect of trehalose was mediated by a reduced colocalization of APP and BACE1 in the cell, and, therefore, a lower amyloidogenic processing of APP. This observation illustrates that the determination of the mechanism, or mechanisms, that associate APP and BACE is a relevant therapeutic target to investigate., Spanish Ministry of Science, Innovation and University (RTI 2018-096303-B-C1), the Comunidad de Madrid (CAM-Biomedicina, B2017/BMD-3700), and the Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED) [PI2016/01]

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by a deterioration of neuronal connectivity. The pathological accumulation of tau in neurons is one of the hallmarks of AD and has been connected to the loss of dendritic spines of pyramidal cells, which are the major targets of cortical excitatory synapses and key elements in memory storage. However, the detailed mechanisms underlying the loss of dendritic spines in individuals with AD are still unclear. Here, we used graph-theory approaches to compare the distribution of dendritic spines from neurons with and without tau pathology of AD individuals. We found that the presence of tau pathology determines the loss of dendritic spines in clusters, ruling out alternative models where spine loss occurs at random locations. Since memory storage has been associated with synaptic clusters, the present results provide a new insight into the mechanisms by which tau drives synaptic damage in AD, paving the way to memory deficits through alterations of spine organization., This work was supported by grants from the Spanish Ministerio de Ciencia, Innovación y Universidades (Grant IJCI-2016-27658 to PMS, Grant PGC2018-094307-B-I00), the Cajal Blue Brain Project (the Spanish partner of the Blue Brain Project initiative from EPFL, Switzerland) and the Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED, CB06/05/0066, Spain). JBP is currently supported by Grants from the Swedish Research Council (#2018-02201), Hjärnfonden (#FO2019-0289), Alzheimerfonden (#AF-930827) and the Strategic Research Programme in Neuroscience at Karolinska Institutet (Stratneuro Startup Grant).

Long-term high-fat diet (HFD) consumption commonly leads to obesity, a major health concern of western societies and a risk factor for Alzheimer's disease (AD). Both conditions present glial activation and inflammation and show sex differences in their incidence, clinical manifestation, and disease course. HFD intake has an important impact on gut microbiota, the bacteria present in the gut, and microbiota dysbiosis is associated with inflammation and certain mental disorders such as anxiety. In this study, we have analyzed the effects of a prolonged (18 weeks, starting at 7 months of age) HFD on male and female mice, both wild type (WT) and TgAPP mice, a model for AD, investigating the behavioral profile, gut microbiota composition and inflammatory/phagocytosis-related gene expression in hippocampus. In the open-field test, no overt differences in motor activity were observed between male and female or WT and TgAPP mice on a low-fat diet (LFD). However, HFD induced anxiety, as judged by decreased motor activity and increased time in the margins in the open-field, and a trend towards increased immobility time in the tail suspension test, with increased defecation. Intriguingly, female TgAPP mice on HFD showed less immobility and defecation compared to female WT mice on HFD. HFD induced dysbiosis of gut microbiota, resulting in reduced microbiota diversity and abundance compared with LFD fed mice, with some significant differences due to sex and little effect of genotype. Gene expression of pro-inflammatory/phagocytic markers in the hippocampus were not different between male and female WT mice, and in TgAPP mice of both sexes, some cytokines (IL-6 and IFN¿) were higher than in WT mice on LFD, more so in female TgAPP (IL-6). HFD induced few alterations in mRNA expression of inflammatory/phagocytosis-related genes in male mice, whether WT (IL-1ß, MHCII), or TgAPP (IL-6). However, in female TgAPP, altered gene expression returned towards control levels following prolonged HFD (IL-6, IL-12ß, TNF¿, CD36, IRAK4, PYRY6). In summary, we demonstrate that HFD induces anxiogenic symptoms, marked alterations in gut microbiota, and increased expression of inflammatory genes, except for female TgAPP that appear to be resistant to the diet effects. Lifestyle interventions should be introduced to prevent AD onset or exacerbation by reducing inflammation and its associated symptoms; however, our results suggest that the eventual goal of developing prevention and treatment strategies should take sex into consideration., This work was supported by Ministerio de Economía, Industria y Competitividad (MINECO), Grant Numbers BFU2014-51836-C2-1-R to LMGS and MAA, BFU2014-51836-C2-2-R and BFU2017-82565-C21-R2 to JAC; Madrid Council S2010/BMD-2349 to MLC; Centre for Biomedical Network Research for Physiopathology of Obesity and Nutrition (CIBEROBN) to JAC, Centre for Biomedical Network Research for Frailty and Healthy Ageing (CIBERFES) to LMGS and MAA, and Centre for Biomedical Network Research for Neurodegenerative Diseases (CIBERNED) to MLC. AC-C was granted with a FPI fellowship by the MINECO (BES-2015-072980).

Huntington's disease (HD) is an inherited progressive neurodegenerative disease characterized by brain atrophy particularly in the striatum that produces motor impairment, and cognitive and psychiatric disturbances. Multiple pathogenic mechanisms have been proposed including dysfunctions in neurotrophic support and calpain-overactivation, among others. Kinase D-interacting substrate of 220 kDa (Kidins220), also known as ankyrin repeat-rich membrane spanning (ARMS), is an essential mediator of neurotrophin signaling. In adult brain, Kidins220 presents two main isoforms that differ in their carboxy-terminal length and critical protein-protein interaction domains. These variants are generated through alternative terminal exon splicing of the conventional exon 32 (Kidins220-C32) and the recently identified exon 33 (Kidins220-C33). The lack of domains encoded by exon 32 involved in key neuronal functions, including those controlling neurotrophin pathways, pointed to Kidins220-C33 as a form detrimental for neurons. However, the functional role of Kidins220-C33 in neurodegeneration or other pathologies, including HD, has not been explored. In the present work, we discover an unexpected selective downregulation of Kidins220-C33, in the striatum of HD patients, as well as in the R6/1 HD mouse model starting at early symptomatic stages. These changes are C33-specific as Kidins220-C32 variant remains unchanged. We also find the early decrease in Kidins220-C33 levels takes place in neurons, suggesting an unanticipated neuroprotective role for this isoform. Finally, using ex vivo assays and primary neurons, we demonstrate that Kidins220-C33 is downregulated by mechanisms that depend on the activation of the protease calpain. Altogether, these results strongly suggest that calpain-mediated Kidins220-C33 proteolysis modulates onset and/or progression of HD., This work was supported by the Spanish Ministerio de Ciencia, Innovación y Universidades (MCIU) grants to T.I. (SAF2017‐88885‐R), J.J.L. (SAF2015‐65371‐R) and M.R.C. (SAF2017‐88881‐R); by B2017/BMD‐3700 NEUROMETAB‐CM (Comunidad de Madrid, Madrid, Spain) to T.I. and institutional grants to CBMSO from Fundación Ramón Areces and Fundación Banco de Santander to J.J.L. T.I. and J.J.L. are also funded by Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED) and CIBERNED cooperative project 2015‐2/06 (Instituto de Salud Carlos III, Spain). GS work was supported by the Wellcome Trust Senior Investigator Award (107116/Z/15/Z), the European Union's Horizon 2020 Research and Innovation programme under grant agreement 739572 and a UK Dementia Research Institute Foundation award. A.S.‐S. was funded by a contract from CIBERNED‐2015‐2/06.

© The Author(s) 2019., Excitotoxic neuronal death induced by high concentrations of glutamate is a pathological event common to multiple acute or chronic neurodegenerative diseases. Excitotoxicity is mediated through overactivation of the N-Methyl-D-aspartate type of ionotropic glutamate receptors (NMDARs). Physiological stimulation of NMDARs triggers their endocytosis from the neuronal surface, inducing synaptic activity and survival. However almost nothing is known about the internalization of overactivated NMDARs and their interacting proteins, and how this endocytic process is connected with neuronal death has been poorly explored. Kinase D-interacting substrate of 220 kDa (Kidins220), also known as ankyrin repeat-rich membrane spanning (ARMS), is a component of NMDAR complexes essential for neuronal viability by the control of ERK activation. Here we have investigated Kidins220 endocytosis induced by NMDAR overstimulation and the participation of this internalization step in the molecular mechanisms of excitotoxicity. We show that excitotoxicity induces Kidins220 and GluN1 traffic to the Golgi apparatus (GA) before Kidins220 is degraded by the protease calpain. We also find that excitotoxicity triggers an early activation of Rap1-GTPase followed by its inactivation. Kidins220 excitotoxic endocytosis and subsequent calpain-mediated downregulation governs this late inactivation of Rap1 that is associated to decreases in ERK activity preceding neuronal death. Furthermore, we identify the molecular mechanisms involved in the excitotoxic shutoff of Kidins220/Rap1/ERK prosurvival cascade that depends on calpain processing of Rap1-activation complexes. Our data fit in a model where Kidins220 targeting to the GA during early excitotoxicity would facilitate Rap1 activation and subsequent stimulation of ERK. At later times, activation of Golgi-associated calpain, would promote the degradation of GA-targeted Kidins220 and two additional components of the specific Rap1 activation complex, PDZ-GEF1, and S-SCAM. In this way, late excitotoxicity would turn off Rap1/ERK cascade and compromise neuronal survival., This work was funded by grants SAF2014-52737-P and SAF2017-88885-R to T.I., BFU2016-75973-R to M.D.-G and BFU2015-63769-R to R.L. (Spanish Ministry ofScience, Innovation and Universities—MICIU, Spain). It was also supported by grant SBPLY/17/180501/000229 from Junta de Comunidades de Castilla-La Mancha to R.L. Additional funding to T.I. was received by Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED, Instituto de Salud Carlos III, Spain) as well as by grant S2017/BMD3700 (NEUROMETAB-CM) from Comunidad de Madrid co-financed with the Structural Funds of the European Union (FEDER). A.G.-M. was funded by contracts from CIBERNED. Contracts to A.S.-G and J.P.U were funded by grants S2017/BMD-3700 (NEUROMETAB-CM) and SAF2017-88885-R, respectively. The cost of this publication has been paid in part by FEDER funds.

Frontotemporal dementia (FTD) is characterized by neuronal loss in the frontal and temporal lobes of the brain. Here, we provide the first evidence of striking morphological alterations in dentate granule cells (DGCs) of FTD patients and in a mouse model of the disease, TauVLW mice. Taking advantage of the fact that the hippocampal dentate gyrus (DG) gives rise to newborn DGCs throughout the lifetime in rodents, we used RGB retroviruses to study the temporary course of these alterations in newborn DGCs of female TauVLW mice. In addition, retroviruses that encode either PSD95:GFP or Syn:GFP revealed striking alterations in the afferent and efferent connectivity of newborn TauVLW DGCs, and monosynaptic retrograde rabies virus tracing showed that these cells are disconnected from distal brain regions and local sources of excitatory innervation. However, the same cells exhibited a predominance of local inhibitory innervation. Accordingly, the expression of presynaptic and postsynaptic markers of inhibitory synapses was markedly increased in the DG of TauVLW mice and FTD patients. Moreover, an increased number of neuropeptide Y-positive interneurons in the DG correlated with a reduced number of activated egr-1+ DGCs in TauVLW mice. Finally, we tested the therapeutic potential of environmental enrichment and chemoactivation to reverse these alterations in mice. Both strategies reversed the morphological alterations of newborn DGCs and partially restored their connectivity in a mouse model of the disease. Moreover, our data point to remarkable morphological similarities between the DGCs of TauVLW mice and FTD patients.SIGNIFICANCE STATEMENT We show, for the first time to our knowledge, that the population of dentate granule cells is disconnected from other regions of the brain in the neurodegenerative disease frontotemporal dementia (FTD). These alterations were observed in FTD patients and in a mouse model of this disease. Moreover, we tested the therapeutic potential of two strategies, environmental enrichment and chemoactivation, to stimulate the activity of these neurons in mice. We found that some of the alterations were reversed by these therapeutic interventions., Association for Frontotemporal Degeneration (2016 Basic Science Pilot Grant Award to M.L.-M.); the Comunidad de Madrid (PEJD-2017-PRE/BMD-3439 to M.L.-M.); the Center for Networked Biomedical Research on Neurodegenerative Diseases (CIBERNED to J.A.); the Argentine Agency for the Promotion of Science and Technology (PICT2015-3814 and PICT2013-1685 to A.S.); the Howard Hughes Medical Institute (SIRS Grant 55007652 to A. S.); and the National Institute on Aging (Intramural Research Program to H.v.P.). Institutional grants from the Fundación Ramón Areces and Banco de Santander to the CBMSO; the Spanish Ministry of Economy and Competitiveness (SAF-2017-82185-R

Despite extensive studies regarding tau phosphorylation progression in both human Alzheimer's disease cases and animal models, the molecular and structural changes responsible for neurofibrillary tangle development are still not well understood. Here, by using the antibodies AT100 (recognizes tau protein phosphorylated at Thr212 and Ser214 in the proline-rich region) and pS396 (recognizes tau protein phosphorylated at serine residue 396 in the C-terminal region), we examined phospho-tau immunostaining in neurons from the hippocampal CA1 region of 21 human cases with tau pathology ranging from Braak stage I to VI. Our results indicate that the AT100/pS396 ratio decreases in CA1 in accordance with the severity of the disease, along with its colocalization. We therefore propose the AT100/pS396 ratio as a new tool to analyze the tau pathology progression. Our findings also suggest a conformational modification in tau protein that may cause the disappearance of the AT100 epitope in the late stages of tau pathology, which may play a role in the toxic tangle aggregation. Thus, this study provides new insights underlying the stages for the formation of neurofibrillary tangles in Alzheimer's disease., This work was supported by grants from the following entities: the Spanish Ministerio de Ciencia, Innovación y Universidades (Grants SAF 2015-66603-P and Cajal Blue Brain Project, Spanish partner of the Blue Brain Project initiative from EPFL, Switzerland to JDF and Grant BFU 2016-77885-P to JA and FH), Comunidad de Madrid (S2017/BMD-3700) to JA and FH, Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED, Spain, CB06/05/0066) and the Alzheimer’s Association (ZEN-15-321663) to JDF.

It is well known that transgenic mice overexpressing human tau protein with P301S mutation driven by the mouse prion protein promoter show clasping and limb retraction, hunched back and paralysis, followed by inability to feed that results in death around 12 months of age. To understand these motor deficits, we have carried out rotarod tests on PS19 line and demonstrated how they worsened during aging. Then, we have analyzed if these phenotypic characteristics correlate with sciatic nerve degeneration. We first demonstrated by western blot and immunohistochemistry that the sciatic nerve expresses the transgenic tau protein; then, electron microscopy studies showed alterations in myelin, mainly a detachment of myelin lamellae at Schmidt-Lanterman clefts. Similar motor deficits and myelin alterations have been previously reported in tau knockout and overexpressing transgenic mice; taking into account that PS19 model is widely used to study tauopathies, we suggest that analyzing the expression of transgenic tau protein and myelin abnormalities in the sciatic nerve should be considered when studying some features as motor performance or survival., Spanish Ministry of Economy and Competitiveness (BFU2016-77885-P), Comunidad de Madrid cofinanced with the Structural Funds of the European Union (S2017/BMD-3700 (NEUROMETAB-CM)), Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED, ISCIII), and from an institutional grant from the Fundación R. Areces

Pre-synaptic secretion of brain-derived neurotrophic factor (BDNF) from noradrenergic neurons may protect the Alzheimer's disease (AD) brain from amyloid pathology. While the BDNF polymorphism (rs6265) is associated with faster cognitive decline and increased hippocampal atrophy, a replicable genetic association of BDNF with AD risk has yet to be demonstrated. This could be due to masking by underlying epistatic interactions between BDNF and other loci that encode proteins involved in moderating BDNF secretion (DBH and Sortilin).We performed a multi-cohort case-control association study of the BDNF,DBH, and SORT1 loci comprising 5,682 controls and 2,454ADpatients from Northern Europe(87% of samples) and Spain (13%). The BDNF locus was associated with increased AD risk (odds ratios; OR= 1.1-1.2, p = 0.005-0.3), an effect size that was consistent in the Northern European (OR = 1.1-1.2, p = 0.002-0.8) but not the smaller Spanish (OR = 0.8-1.6, p = 0.4-1.0) subset. A synergistic interaction between BDNF and sex (synergy factor; SF = 1.3-1.5 p = 0.002-0.02) translated to a greater risk of AD associated with BDNF in women (OR = 1.2-1.3, p = 0.007-0.00008) than men (OR = 0.9-1.0, p = 0.3-0.6). While the DBH polymorphism (rs1611115) was also associated with increased AD risk (OR = 1.1, p = 0.04) the synergistic interaction (SF = 2.2, p = 0.007) betweenBDNF(rs6265) andDBH(rs1611115) contributed greater AD risk than either gene alone, an effect that was greater in women (SF = 2.4, p = 0.04) than men (SF = 2.0, p = 0.2). These data support a complex genetic interaction at loci encoding proteins implicated in the DBH-BDNF inflammatory pathway that modifies AD risk, particularly in women., Alzheimer’s Research UK and Alzheimer’s Society and is supported by BRACE (Bristol Research into Alzheimer’s and Care of the Elderly) and the Medical Research Council. This research benefitted from funding awarded to the NIHR Great Ormond Street Hospital Biomedical Research Centre. OB, P S-J and ER were supported by grants from, IDIVAL, Instituto de Salud Carlos III (Fondo de Investigación Sanitario) and European Funds for Regional Development (FEDER); PI15/00058, CP13/00091, PI08/0139, PI12/02288, PI16/01652, PI13/01008), JPND (DEMTEST PI11/03028 and the CIBERNED program. The Rotterdam Study is funded by Erasmus Medical Center and Erasmus University, Rotterdam, Netherlands Organization for the Health Research and Development (ZonMw), the Research Institute for Diseases in the Elderly (RIDE1 and 2), the Ministry of Education, Culture and Science, the Ministry for Health, Welfare and Sports, the European Commission (DG XII), and the Municipality genotype data for the Rotterdam Study is supported by the Netherlands Organisation of Scientific Research NWO Investments (nr. 175.010.2005.011, 911-03-012)

Most data are available in the main text or the Supplementary Materials. The datasets used and analyzed during the current study are published in the EBRAINS Knowledge Graph (DOI: 10.25493/5F04-N97): Domínguez-Álvaro M, Montero M, Alonso-Nanclares L, Blazquez-Llorca L, Rodríguez J-R, DeFelipe J. (2020). Densities and 3D distributions of synapses using FIB/SEM imaging in the human neocortex (Temporal cortex, T2) [Data set]. Human Brain Project Neuroinformatics Platform., In the present study, we have used Focused Ion Beam/Scanning Electron Microscopy (FIB/SEM) to perform a study of the synaptic organization of layer III of Brodmann’s area 21 in human tissue samples obtained from autopsies and biopsies. We analyzed the synaptic density, 3D spatial distribution, and type (asymmetric/symmetric), as well as the size and shape of each synaptic junction of 4945 synapses that were fully reconstructed in 3D. Significant differences in the mean synaptic density between autopsy and biopsy samples were found (0.49 and 0.66 synapses/μm3 , respectively). However, in both types of samples (autopsy and biopsy), the asymmetric:symmetric ratio was similar (93:7) and most asymmetric synapses were established on dendritic spines (75%), while most symmetric synapses were established on dendritic shafts (85%). We also compared several electron microscopy methods and analysis tools to estimate the synaptic density in the same brain tissue. We have shown that FIB/SEM is much more reliable and robust than the majority of the other commonly used EM techniques. The present work constitutes a detailed description of the synaptic organization of cortical layer III. Further studies on the rest of the cortical layers are necessary to better understand the functional organization of this temporal cortical region., This study was funded by grants from the following entities: Spanish “Ministerio de Ciencia e Innovación” grant PGC2018-094307-B-I00, and the Cajal Blue Brain Project made available under aCC-BY-NC 4.0 International license. (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is bioRxiv preprint doi: https://doi.org/10.1101/2021.01.18.427131; this version posted April 8, 2021. The copyright holder for this preprint 59 (the Spanish partner of the Blue Brain Project initiative from EPFL [Switzerland]); Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED, Spain, CB06/05/0066); and the European Union’s Horizon 2020 Framework Programme for Research and Innovation under Specific Grant Agreement No. 945539 (Human Brain Project SGA3). N C-A was awarded a research fellowship from the Spanish “Ministerio de Ciencia e Innovación” (PRE2019-089228).

FIB-SEM is an electron microscopy technique that allows the acquisition of serial sections in an automated manner. A Focused Ion Beam (FIB) is directed toward the specimen, removing material from its surface. Since the FIB can be positioned and controlled on a nanometer scale, the specimen surface can be milled so that a thin layer of a specified thickness is removed. The Scanning Electron Microscope (SEM) column is then used to acquire an image from the freshly milled surface. To obtain a series of images, the milling/imaging cycle is repeated automatically. This technique can be used with any pre-embedding method that yields an electron-dense end product. We describe here an immunocytochemical protocol to be used on vibratome brain sections. After the immunocytochemical procedure, the sections are flat embedded in epoxy resin and prepared for FIB-SEM imaging. Serial image acquisition, visualization, and analysis in 3D are also briefly described., This work was partially supported by grants from the following entities: Centro de Investigación en Red sobre Enfermedades Neurodegenerativas (CIBERNED, CB06/05/0066, Spain); and the Spanish Ministerio de Ciencia, Innovación y Universidades (grant PGC2018-094307-B-I00 and the Cajal Blue Brain Project [the Spanish partner of the Blue Brain Project initiative from EPFL, Switzerland]).

Senile plaque formation as a consequence of amyloid- peptide (A ) aggregation constitutes one of the main hallmarks of Alzheimer’s disease (AD). This pathology is characterized by synaptic alterations and cognitive impairment. In order to either prevent or revert it, different therapeutic approaches have been proposed, and some of them are focused on diet modification. Modification of the !-6/!-3 fatty acids (FA) ratio in diets has been proven to affect A production and senile plaque formation in the hippocampus and cortex of female transgenic (TG) mice. In these diets, linoleic acid is the main contribution of !-6 FA, whereas alpha-linoleic acid (ALA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA) are the contributors of !-3 FA. In the present work, we have explored the effect of !-6/!-3 ratio modifications in the diets of male double-transgenic APPswe/PS1DE9 (AD model) and wild-type mice (WT). Amyloid burden in the hippocampus increased in parallel with the increase in dietary !-6/!-3 ratio in TG male mice. In addition, there was a modification in the brain lipid profile proportional to the !-6/!-3 ratio of the diet. In particular, the higher the !-6/!-3 ratio, the lower the ceramides and higher the FAs, particularly docosatetraenoic acid. Modifications to the cortex lipid profile was mostly similar between TG and WT mice, except for gangliosides (higher levels in TG mice) and some ceramide species (lower levels in TG mice), Spanish Ministry of Science, Innovation and University (RTI 2018-096303-B-C1) and Comunidad de Madrid (CAM-Biomedicina, B2017/BMD-3700) and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativa (CIBERNED) [PI2016/01]. GM and JC lab was supported by the Spanish Ministry of Science, Innovation and University

Pyramidal neurons are the most abundant and characteristic neuronal type in the cerebral cortex and their dendritic spines are the main postsynaptic elements of cortical excitatory synapses. Previous studies have shown that pyramidal cell structure differs across layers, cortical areas, and species. However, within the human cortex, the pyramidal dendritic morphology has been quantified in detail in relatively few cortical areas. In the present work, we performed intracellular injections of Lucifer Yellow at several distances from the temporal pole. We found regional differences in pyramidal cell morphology, which showed large inter-individual variability in most of the morphological variables measured. However, some values remained similar in all cases. The smallest and least complex cells in the most posterior temporal region showed the greatest dendritic spine density. Neurons in the temporal pole showed the greatest sizes with the highest number of spines. Layer V cells were larger, more complex, and had a greater number of dendritic spines than those in layer III. The present results suggest that, while some aspects of pyramidal structure are conserved, there are specific variations across cortical regions, and species., The Spanish “Ministerio de Ciencia e Innovación” (grant PGC2018-094307-B-I00); the Cajal Blue Brain Project (the Spanish partner of the Blue Brain Project initiative from EPFL, [Switzerland]); Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED, Spain, CB06/05/0066); and the European Union’s Horizon 2020 Framework Programme for Research and Innovation (under Specific grant agreement No. 785907, Human Brain Project SGA2, and Specific grant agreement No. 945539; Human Brain Project SGA3).

Studies are needed to identify useful biomarkers to assess the severity and prognosis of COVID-19 disease, caused by severe acute respiratory syndrome coronavirus (SARS-CoV-2) virus. Here, we examine the levels of various plasma species of the SARS-CoV-2 host receptor, the angiotensin-converting enzyme 2 (ACE2), in patients at different phases of the infection. Human plasma ACE2 species were characterized by immunoprecipitation and western blotting employing antibodies against the ectodomain and the C-terminal domain, using a recombinant human ACE2 protein as control. In addition, changes in the cleaved and full-length ACE2 species were also examined in serum samples derived from humanized K18-hACE2 mice challenged with a lethal dose of SARS-CoV-2. ACE2 immunoreactivity was present in human plasma as several molecular mass species that probably comprise truncated (70 and 75 kDa) and full-length forms (95, 100, 130, and 170 kDa). COVID-19 patients in the acute phase of infection (n = 46) had significantly decreased levels of ACE2 full-length species, while a truncated 70-kDa form was marginally higher compared with non-disease controls (n = 26). Levels of ACE2 full-length species were in the normal range in patients after a recovery period with an interval of 58-70 days (n = 29), while the 70-kDa species decreased. Levels of the truncated ACE2 species served to discriminate between individuals infected by SARS-CoV-2 and those infected with influenza A virus (n = 17). In conclusion, specific plasma ACE2 species are altered in patients with COVID-19 and these changes normalize during the recovery phase. Alterations in ACE2 species following SARS-CoV-2 infection warrant further investigation regarding their potential usefulness as biomarkers for the disease process and to asses efficacy during vaccination., This study was funded in part by the Instituto de Investigación Sanitaria y Biomédica de Alicante (ISABIAL; grants 190258 and 2020-0308) and by the Instituto de Salud Carlos III (ISCIII, grants PI19-01359), co-financed by the Fondo Europeo de Desarrollo Regional (FEDER, “Investing in your future”) and through CIBERNED, ISCIII. 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). Work at CNB and CISA is funded by the Spanish Health Ministry, ISCIII, Fondo COVID-19 grant COV20/00151, and Fondo Supera COVID-19 (Crue Universidades-Banco Santander) (to JGA). MACG is supported by BEFPI fellowship from the Generalitat Valenciana. HZ is a Wallenberg Scholar supported by grants from the Swedish Research Council (#2018-02532), the European Research Council (#681712), and Swedish State Support for Clinical Research (#ALFGBG-720931).

Alterations in brain cholesterol homeostasis in midlife are correlated with a higher risk of developing Alzheimer’s disease (AD). However, global cholesterol-lowering therapies have yielded mixed results when it comes to slowing down or preventing cognitive decline in AD. We used the transgenic mouse model Cyp27Tg, with systemically high levels of 27-hydroxycholesterol (27-OH) to examine long-term potentiation (LTP) in the hippocampal CA1 region, combined with dendritic spine reconstruction of CA1 pyramidal neurons to detect morphological and functional synaptic alterations induced by 27-OH high levels. Our results show that elevated 27-OH levels lead to enhanced LTP in the Schaffer collateral-CA1 synapses. This increase is correlated with abnormally large dendritic spines in the stratum radiatum. Using immunohistochemistry for synaptopodin (actin-binding protein involved in the recruitment of the spine apparatus), we found a significantly higher density of synaptopodin-positive puncta in CA1 in Cyp27Tg mice. We hypothesize that high 27-OH levels alter synaptic potentiation and could lead to dysfunction of fine-tuned processing of information in hippocampal circuits resulting in cognitive impairment. We suggest that these alterations could be detrimental for synaptic function and cognition later in life, representing a potential mechanism by which hypercholesterolemia could lead to alterations in memory function in neurodegenerative diseases., This research was supported by the following entities: Margaretha af Ugglas Stiftelse, Gun och Bertil Stohnes Stiftelse, Karolinska Institutet fund for geriatric research, Stiftelsen Gamla Tjänarinnor, Tore Nilsson Stiftelse and Demensfonden to P.M.S. and R.L.V. P.M.S. was the recipient of the EMBO Long-Term Fellowship (ALFT 696-2013), the SSMF postdoctoral Fellowship and Juan de la Cierva (IJCI-2016-27658). R.L.V. and E.V.J. were the recipients of Postdoctoral Fellowships from CONACYT (Mexico, CVU: 209252 and 232099). We also acknowledge grants to R.L.V. from Lindhés Advokatbyra Foundation and the regional agreement on medical training and clinical research (ALF) between Stockholm County Council and Karolinska Institutet. This work was also supported by grants from the following Spanish entities: Centro de Investigación en Red sobre Enfermedades Neurodegenerativas (CIBERNED, CB06/05/0066) and the Ministerio de Ciencia, Innovación y Universidades (grant PGC2018-094307-B-I00).The imaging for this study was performed at the Live Cell Imaging Facility, Karolinska Institutet, Sweden, supported by grants from the Knut and Alice Wallenberg Foundation, the Swedish Research Council, the Centre for Innovative Medicine and the Jonasson Center at the Royal Institute of Technology, Sweden. We would like to thank Carmen Álvarez and Lorena Valdés for their helpful assistance, Laura Paternain Markinez for her assistance with the Cyp27Tg colony maintenance and Nick Guthrie for his excellent text editing.

It is known that aging is frequently accompanied by a decline in cognition. Furthermore, aging is associated with lower serum IGF-I levels that may contribute to this deterioration. We studied the effect of IGF-I in neurons of the horizontal diagonal band of Broca (HDB) of young (≤6 months old) and old (≥20-month-old) mice to determine if changes in the response of these neurons to IGF-I occur along with aging. Local injection of IGF-I in the HDB nucleus increased their neuronal activity and induced fast oscillatory activity in the electrocorticogram (ECoG). Furthermore, IGF-I facilitated tactile responses in the primary somatosensory cortex elicited by air-puffs delivered in the whiskers. These excitatory effects decreased in old mice. Immunohistochemistry showed that cholinergic HDB neurons express IGF-I receptors and that IGF-I injection increased the expression of c-fos in young, but not in old animals. IGF-I increased the activity of optogenetically-identified cholinergic neurons in young animals, suggesting that most of the IGF-I-induced excitatory effects were mediated by activation of these neurons. Effects of aging were partially ameliorated by chronic IGF-I treatment in old mice. The present findings suggest that reduced IGF-I activity in old animals participates in age-associated changes in cortical activity., This work has been supported by Grants from Ciberned and the Spanish Ministerio de Ciencia e Innovación (SAF2016-76462, AEI/FEDER, and PID2019-107809RB-I00). JZ-V acknowledges the financial support of the National Council of Science, Technology and Technological Innovation (CONCYTEC, Perú) through the National Fund for Scientific and Technological Development (FONDECYT, Perú).

The addition of new neurons to the existing hippocampal circuitry persists in the adult dentate gyrus (DG). During this process, named adult hippocampal neurogenesis (AHN), adult hippocampal progenitor cells (AHPs) give rise to newborn dentate granule cells (DGCs). The acquisition of a neuronal lineage by AHPs is tightly regulated by numerous signaling molecules and transcription factors. In this regard, glycogen synthase kinase 3β (GSK-3β) is a master regulator of the maturation of AHPs in vitro. Here we analyzed the cell-autonomous effects of overexpressing a constitutively active form of GSK-3β (GSK-3β S9A) in AHPs in vivo. To this end, we stereotaxically injected a GSK-3β S9A-encoding retrovirus (GSK-3β-V5) into the DG of young adult C57BL6/J Ola Hsd female mice and studied the cell lineage acquisition, migratory and marker expression patterns, and the morphological maturation of the infected cells over time. Strikingly, GSK-3β S9A-transduced cells expressed glial fibrillary acidic protein (GFAP) and NG2, thereby acquiring an immature astroglial phenotype, which differed markedly from the neuronal phenotype observed in cells transduced with a control retrovirus that encoded GFP. Accordingly, the morphology and migration patterns of cells transduced by the two retroviruses are remarkably divergent. These observations support the role of GSK-3β as a cornerstone that regulates the balance between new astocytes/neurons generated in the adult murine DG., Ministry of Economy and Competitiveness ((SAF-2017-82185-R and RYC-2015-171899 (M LL-M)); (SAF-2014-53040-P (J A))); The Alzheimer ́s Association (2015-NIRG-340709, AARG-17-528125, and AARG-17-528125-RAPID) (M LL-M); The Association for Frontotemporal Degeneration (2016 Basic Science Pilot Grant Award (M L-M)); and the Center for Networked Biomedical Research on Neurodegenerative Diseases (CIBERNED, Spain) (J A). Institutional grants from the Fundacion Ramon Areces and Banco de Santander

10 páginas, 5 figuras, 5 tablas, The increased pressure on primary care makes it important for other health care providers, such as community pharmacists, to collaborate with general practitioners in activities related to chronic disease care. Therefore, the objective of the present project was to develop a protocol of action that allows close pharmacist-physician collaboration to carry out a coordinated action for very early detection of cognitive impairment (CI). Methods: A comparative study to promote early detection of CI was conducted in 19 community pharmacies divided into two groups: one group with interprofessional collaboration (IPC) and one group without interprofessional collaboration (NonIPC). IPC was defined as an interactive procedure involving all pharmacists, general practitioners and neurologists. A total of 281 subjects with subjective memory complaints were recruited. Three tests were used in the community pharmacies to detect possible CI: Memory Impairment Screening, Short Portable Mental State Questionnaire, and Semantic Verbal Fluency. Individuals with at least one positive cognitive test compatible with CI, were referred to primary care, and when appropriate, to the neurology service. Finally, we evaluated the differences in clinical and diagnostic follow-up in both groups after six months. Results: The NonIPC study group included 38 subjects compatible with CI referred to primary care (27.54%). Ten were further referred to a neurology department (7.25%) and four of them (2.90%) obtained a confirmed clinical diagnosis of CI. In contrast, in the IPC group, 46 subjects (32.17%) showed results compatible with CI and were referred to primary care. Of these, 21 (14.68%) were subsequently referred to a neurology service, while the remaining 25 were followed up by primary care. Nineteen individuals out of those referred to a neurology service obtained a confirmed clinical diagnosis of CI (13.29%). The percentage of subjects in the NonIPC group referred to neurology and the percentage of subjects diagnosed with CI, was significantly lower in comparison to the IPC group (p-value = 0.0233; p-value = 0.0007, respectively). Conclusions: The creation of IPC teams involving community pharmacists, general practitioners, and neurologists allow for increased detection of patients with CI or undiagnosed dementia and facilitates their clinical follow-up. This opens the possibility of diagnosis in patients in the very early stages of dementia, which can have positive implications to improve the prognosis and delay the evolution of the disease., Catedra DeCo Micof-UCH and Fundación Domus that partially funded this research, and all the patients who trusted us and participated in this work. Work at JPT laboratory was possible thanks to funding from CIBERNED and generous gifts from Consuelo Cervera Yuste and Juan Manuel Moreno Cervera

Trabajo presentado en el 19th National Meeting of the Spanish Society of Neuroscience, celebrado en Lleida (España), del 3 al 5 de noviembre de 2021, Mitochondrial DNA (mtDNA) encodes proteins that are necessary for the production of cellular energy by the mitochondria. In neurons, shortage of this energy due to mitochondrial dysfunction triggers neurodegeneration. In our previous studies, we reported that subjects with pathogenic mutations that cause familial Alzheimer’s disease exhibit low content of cell-free mtDNA (cf-mtDNA) in cerebrospinal fluid (CSF) before the appearance of clinical signs, suggesting that a decrease in the CSF content of cf-mtDNA precedes the clinical signs of dementia. However, the source and the mechanisms of cf-mtDNA release are unclear. Moreover, the molecular mechanisms involved in regulation of mtDNA copy number and release by different genes that cause familiar Alzheimer’s disease are unknown. To explore these questions, we have now investigated the effect of APP-Swe/Ind and PSEN1dE9 mutations on mtDNA replication, transcription and release in SH-SY5Y cell clones that permanently express these mutations. We found that either APP-Swe/Ind or PSEN1d9 gene mutations both reduce mtDNA copy number, the amount of L-strand and H-strand mtDNA transcripts per cell, and the release of cf-mtDNA. In addition, we found that pharmacological inhibition of mitophagy enhances the release of cf-mtDNA in control cells, but not in cell clones expressing APP-Swe/Ind and PSEN1dE9 mutations. These results indicate the presence of an mtDNA quality control system independent of mitophagy that is impaired by APP-Swe/Ind and PSEN1dE9 mutations. Moreover, the present results show that alteration of mtDNA dynamics is a common factor of different pathogenic mutations that cause Alzheimer’s disease., Supported by SAF2017-89791-R, CIBERNED PI2020/09-04 and CIBERNED CB06/05/0050 grants.

Microglia are the cells that comprise the innate immune system in the brain. First described more than a century ago, these cells were initially assigned a secondary role in the central nervous system (CNS) with respect to the protagonists, neurons. However, the latest advances have revealed the complexity and importance of microglia in neurodegenerative conditions such as Alzheimer’s disease (AD), the most common form of dementia associated with aging. This pathology is characterized by the accumulation of amyloid- peptide (A), which forms senile plaques in the neocortex, as well as by the aggregation of hyperphosphorylated tau protein, a process that leads to the development of neurofibrillary tangles (NFTs). Over the past few years, efforts have been focused on studying the interaction between A and microglia, together with the ability of the latter to decrease the levels of this peptide. Given that most clinical trials following this strategy have failed, current endeavors focus on deciphering the molecular mechanisms that trigger the tau-induced inflammatory response of microglia. In this review, we summarize the most recent studies on the physiological and pathological functions of tau protein and microglia. In addition, we analyze the impact of microglial AD-risk genes (APOE, TREM2, and CD33) in tau pathology, and we discuss the role of extracellular soluble tau in neuroinflammation, Ministry of Science and Innovation (PGC2018-096177-B-00), the Network Center for Biomedical Research on Neurodegenerative Diseases, and Fundación Ramón Areces and Banco de Santander to the Centro de Biología Molecular “Severo Ochoa”

[Background] Blood homocysteine appears to be increased in Parkinson's disease (PD) and may play a role in the development and progression of this disorder. However, the specific contribution of abnormal homocysteine levels to cortical degeneration in PD remains elusive., [Objective] To characterize the cortical structural correlates of homocysteine levels in PD., [Methods] From the COPPADIS cohort, we identified a subset of PD patients and healthy controls (HC) with available homocysteine and imaging data. Surface-based vertex-wise multiple regression analyses were performed to investigate the cortical macrostructural (cortical thinning) and microstructural (increased intracortical diffusivity) correlates of homocysteine levels in this sample., [Results] A total of 137 PD patients and 43 HC were included. Homocysteine levels were increased in the PD group (t = −2.2, p = 0.03), correlating in turn with cognitive performance (r = −0.2, p = 0.03). Homocysteine in PD was also associated with frontal cortical thinning and, in a subset of patients with available DTI data, with microstructural damage in frontal and posterior-cortical regions (p < 0.05 Monte-Carlo corrected)., [Conclusions] Homocysteine in PD appears to be associated with cognitive performance and structural damage in the cerebral cortex. These findings not only reinforce the presence and importance of cortical degeneration in PD, but also suggest that homocysteine plays a role among the multiple pathological processes thought to be involved in its development., This work was partially supported by funds from CERCA, CIBERNED, la Marató de TV3 (grants #2014/U/477 and #20142910), Fondo de Investigaciones Sanitarias (grants #PI15/00962 and #PI18/01717FIS), Instituto de Salud Carlos III (ISCIII) and Fondo Europeo de Desarrollo Regional (FEDER). MJG receives support from the “Miguel Servet” program [CP19/00031] and a research grant [PI20/00613] from the ISCIII-FEDER. MALE receives support from the VI-PPIT-US project at the University of Seville [USE-20046-J].

Hepatocellular carcinoma (HCC), the most common form of liver cancer, continues to be a serious medical problem with poor prognosis, without major therapeutic improvement for years and increasing incidence. Fortunately, advances in systemic treatment options are finally arriving for HCC patients. After a decade of sorafenib as a standard therapy for advanced HCC, several tyrosine kinase inhibitors (TKIs), antiangiogenic antibodies, and immune checkpoint inhibitors have reached the clinic. Although infections by hepatitis B virus and hepatitis C virus remain principal factors for HCC development, the rise of non-alcoholic steatohepatitis from diabetes mellitus or metabolic syndrome is impeding HCC decline. Knowledge of specific molecular mechanisms, based on the etiology and the HCC microenvironment that influence tumor growth and immune control, will be crucial for physician decision-making among a variety of drugs to prescribe. In addition, markers of treatment efficacy are needed to speed the movement of patients towards other potentially effective treatments. Consequently, research to provide scientific data for the evidence-based management of liver cancer is guaranteed in the coming years and discussed here., This research was funded by Instituto de Salud Carlos III, grant number PI19/01410 to M.M.; CIBEREHD and CIBERNED; Ministerio de Ciencia e Innovación, grant numbers RTI2018- 095672-B-I00 to A.M. and P.G.F. and RTI2018-095572-B-100 to A.C.; and co-funded by FEDER (Fondo Europeo de Desarrollo Regional, Unión Europea); Ayuda Extraordinaria CSIC 2021AEP095 to A.M. and P.G.F., AGAUR, grant number 2017_SGR_177 to A.M.; Fundació la Marató de TV3 to A.M.; and CERCA Programme/Generalitat de Catalunya.

This article belongs to the Special Issue hiPSC-Derived Cells as Models for Drug Discovery., Extracellular amyloid-beta deposition and intraneuronal Tau-laden neurofibrillary tangles are prime features of Alzheimer’s disease (AD). The pathology of AD is very complex and still not fully understood, since different neural cell types are involved in the disease. Although neuronal function is clearly deteriorated in AD patients, recently, an increasing number of evidences have pointed towards glial cell dysfunction as one of the main causative phenomena implicated in AD pathogenesis. The complex disease pathology together with the lack of reliable disease models have precluded the development of effective therapies able to counteract disease progression. The discovery and implementation of human pluripotent stem cell technology represents an important opportunity in this field, as this system allows the generation of patient-derived cells to be used for disease modeling and therapeutic target identification and as a platform to be employed in drug discovery programs. In this review, we discuss the current studies using human pluripotent stem cells focused on AD, providing convincing evidences that this system is an excellent opportunity to advance in the comprehension of AD pathology, which will be translated to the development of the still missing effective therapies., This study was supported by Instituto de Salud Carlos III (ISCiii) of Spain, co-financed by FEDER funds from European Union, through grants PI18/01557 (to AG), PI18/01556 (to JV), and CIBERNED (CB06/05/1116 to AG and CB06/05/0094 to JV); by Junta de Andalucia through Consejería de Economía y Conocimiento grants UMA18-FEDERJA-211 (to AG), PY18-RT-2233 (to AG) and US-1262734 (to JV) co-financed by Programa Operativo FEDER 2014-2020 and Consejeria de Salud grant PI-0276-2018 (to JAGL); and by Malaga University grant PPIT.UMA.B1.2017/26 (to RSV). JJFV was supported by an FPU PhD fellowship from Spanish Ministry of Science, Innovation, and Universities, and RSV and MMO held a postdoctoral and predoctoral contract, respectively, from Malaga University.