Estimulación cognitiva: una revisión neuropsicológica

Investigaciones recientes ponen en evidencia la capacidad que tienen las neuronas para regenerarse y establecer nuevas conexiones. Por ello, las personas mayores con un envejecimiento fisiológico, con deterioro cognitivo leve o con demencia en fase leve-moderada necesitan una terapia específica temprana, llamada estimulación cognitiva, para restaurar habilidades cognitivas, ralentizar la progresión del deterioro y estabilizar su estado funcional. Actualmente se sabe que dicha terapia, pautada de forma estandarizada y de forma científica, afecta al cerebro potenciando los mecanismos de plasticidad cerebral, la neurogénesis, la reserva cerebral y la angiogénesis.Recent studies demonstrate the ability of neurons to regenerate and make new connections. Therefore, older people with physiological aging, mild cognitive impairment or mild to moderate dementia in an early stage need specific therapy called cognitive stimulation to restore cognitive abilities, slow the progression of deterioration and stabilize their functional status. We now know that this therapy affects the brain by enhancing the mechanisms of brain plasticity, neurogenesis, angiogenesis and brain reserve.Psicologí

El Sistema del Complemento, interactivo y magnético. Memoria final

El modelo didáctico más empleado en la enseñanza universitaria es de tipo transmisivo, centrado en la exposición del profesor/a con el apoyo de las presentaciones y los libros de texto, siendo el alumno/a esencialmente receptor de la enseñanza. Sin embargo, cada vez más se emplean estrategias alternativas para abordar el proceso de enseñanza-aprendizaje desde modelos más centrados en el alumno/a, que favorezcan su implicación, actividad y protagonismo. Con el proyecto de innovación docente: El Sistema del Complemento, interactivo y magnético, queremos desarrollar una herramienta didáctica que nos permita implementar una estrategia de aprendizaje interactiva para el estudio de la cascada de activación del sistema del complemento. La propuesta se ha programado para la asignatura de Fisiopatología del Complemento impartida en el Máster de Investigación en Inmunología (UCM). Para ello, elaboramos material didáctico que consiste en fichas impresas en papel imantado que representan cada uno de los componentes que forman el sistema del complemento de manera que se puedan colocar y mover sobre una pizarra magnética. Este material se pone a disposición de los estudiantes para realizar actividades concretas propuestas por los profesores/as, en las que se trabaja en grupo y de forma interactiva, sirviendo también como herramienta para el repaso de conceptos y resolución de dudas durante las clases teóricas

Atypical hemolytic uremic syndrome-associated variants and autoantibodies impair binding of factor H and factor H-related protein 1 to pentraxin 3

Atypical hemolytic uremic syndrome (aHUS) is a renal disease associated with complement alternative pathway dysregulation and is characterized by endothelial injury. Pentraxin 3 (PTX3) is a soluble pattern recognition molecule expressed by endothelial cells and upregulated under inflammatory conditions. PTX3 activates complement, but it also binds the complement inhibitor factor H. In this study, we show that native factor H, factor H-like protein 1, and factor H-related protein 1 (CFHR1) bind to PTX3 and that PTX3-bound factor H and factor H-like protein 1 maintain their complement regulatory activities. PTX3, when bound to extracellular matrix, recruited functionally active factor H. Residues within short consensus repeat 20 of factor H that are relevant for PTX3 binding were identified using a peptide array. aHUS-associated factor H mutations within this binding site caused a reduced factor H binding to PTX3. Similarly, seven of nine analyzed anti-factor H autoantibodies isolated from aHUS patients inhibited the interaction between factor H and PTX3, and five autoantibodies also inhibited PTX3 binding to CFHR1. Moreover, the aHUS-associated CFHR1*B variant showed reduced binding to PTX3 in comparison with CFHR1*A. Thus, the interactions of PTX3 with complement regulators are impaired by certain mutations and autoantibodies affecting factor H and CFHR1, which could result in an enhanced local complement-mediated inflammation, endothelial cell activation, and damage in aHUS

Activation of the Unfolded Protein Response (UPR) Is Associated with Cholangiocellular Injury, Fibrosis and Carcinogenesis in an Experimental Model of Fibropolycystic Liver Disease

Fibropolycystic liver disease is characterized by hyperproliferation of the biliary epithelium and the formation of multiple dilated cysts, a process associated with unfolded protein response (UPR). In the present study, we aimed to understand the mechanisms of cyst formation and UPR activation in hepatocytic c-Jun N-terminal kinase 1/2 (Jnk1/2) knockout mice. Floxed JNK1/2 (Jnkf/f) and Jnk∆hepa animals were sacrificed at different time points during progression of liver disease. Histological examination of specimens evidenced the presence of collagen fiber deposition, increased α-smooth muscle actin (αSMA), infiltration of CD45, CD11b and F4/80 cells and proinflammatory cytokines (Tnf, Tgfβ1) and liver injury (e.g., ALT, apoptosis and Ki67-positive cells) in Jnk∆hepa compared with Jnkf/f livers from 32 weeks of age. This was associated with activation of effectors of the UPR, including BiP/GRP78, CHOP and spliced XBP1. Tunicamycin (TM) challenge strongly induced ER stress and fibrosis in Jnk∆hepa animals compared with Jnkf/f littermates. Finally, thioacetamide (TAA) administration to Jnk∆hepa mice induced UPR activation, peribiliary fibrosis, liver injury and markers of biliary proliferation and cholangiocarcinoma (CCA). Orthoallografts of DEN/CCl4-treated Jnk∆hepa liver tissue triggered malignant CCA. Altogether, these results suggest that activation of the UPR in conjunction with fibrogenesis might trigger hepatic cystogenesis and early stages of CCA

Factor H-related protein 1 drives disease susceptibility and prognosis in C3 glomerulopathy

17 p.-8 fig.Background: C3 glomerulopathy (C3G) is a heterogeneous group of chronic renal diseases characterized predominantly by glomerular C3 deposition and complement dysregulation. Mutations in factor H-related (FHR) proteins resulting in duplicated dimerization domains are prototypical of C3G, although the underlying pathogenic mechanism is unclear.Methods: Using in vitro and in vivo assays, we performed extensive characterization of an FHR-1 mutant with a duplicated dimerization domain. To assess the FHR-1 mutant's association with disease susceptibility and renal prognosis, we also analyzed CFHR1 copy number variations and FHR-1 plasma levels in two Spanish C3G cohorts and in a control population.Results: Duplication of the dimerization domain conferred FHR-1 with an increased capacity to interact with C3-opsonized surfaces, which resulted in an excessive activation of the alternative pathway. This activation does not involve C3b binding competition with factor H. These findings support a scenario in which mutant FHR-1 binds to C3-activated fragments and recruits native C3 and C3b; this leads to formation of alternative pathway C3 convertases, which increases deposition of C3b molecules, overcoming FH regulation. This suggests that a balanced FHR-1/FH ratio is crucial to control complement amplification on opsonized surfaces. Consistent with this conceptual framework, we show that the genetic deficiency of FHR-1 or decreased FHR-1 in plasma confers protection against developing C3G and associates with better renal outcome.Conclusions: Our findings explain how FHR-1 mutants with duplicated dimerization domains result in predisposition to C3G. They also provide a pathogenic mechanism that may be shared by other diseases, such as IgA nephropathy or age-related macular degeneration, and identify FHR-1 as a potential novel therapeutic target in C3G.E. Goicoechea de Jorge is supported by Ministerio de Ciencia e Innovación grant RTI2018-095955-B-100 and the European Union’s Horizon 2020 Framework Programme grant 899163. J. Gutiérrez-Tenorio is supported by Ministerio de Ciencia e Innovación grant BES-2015-073833. L. Lucientes Continente is supported by the Autonomous Region of Madrid grant S2017/BMD-3673. G. Fernández-Juarez, P. Sánchez-Corral, B. Márquez-Tirado, and M. Praga are supported by the Instituto de Salud Carlos III and the European Union’s European Regional Development Fund grants PI19/01695, PI19/00970, and PI19/01624, respectively. M.C. Pickering is a Wellcome Trust Senior Fellow in Clinical Science (212252/Z/18/Z). S. Rodríguez de Córdoba is supported by the Ministerio de Economía y Competitividad grant PID2019-104912RB-100 and Autonomous Region of Madrid grant S2017/BMD-3673.Peer reviewe

Immunogenic dynamics and SARS-CoV-2 variant neutralisation of the heterologous ChAdOx1-S/BNT162b2 vaccination: Secondary analysis of the randomised CombiVacS study

Background: The CombiVacS study was designed to assess immunogenicity and reactogenicity of the heterologous ChAdOx1-S/BNT162b2 combination, and 14-day results showed a strong immune response. The present secondary analysis addresses the evolution of humoral and cellular response up to day 180. Methods: Between April 24 and 30, 2021, 676 adults primed with ChAdOx1-S were enrolled in five hospitals in Spain, and randomised to receive BNT162b2 as second dose (interventional group [IG]) or no vaccine (control group [CG]). Individuals from CG received BNT162b2 as second dose and also on day 28, as planned based on favourable results on day 14. Humoral immunogenicity, measured by immunoassay for SARS-CoV-2 receptor binding domain (RBD), antibody functionality using pseudovirus neutralisation assays for the reference (G614), Alpha, Beta, Delta, and Omicron variants, as well as cellular immune response using interferon-γ and IL-2 immunoassays were assessed at day 28 after BNT162b2 in both groups, at day 90 (planned only in the interventional group) and at day 180 (laboratory data cut-off on Nov 19, 2021). This study was registered with EudraCT (2021-001978-37) and ClinicalTrials.gov (NCT04860739). Findings: In this secondary analysis, 664 individuals (441 from IG and 223 from CG) were included. At day 28 post vaccine, geometric mean titres (GMT) of RBD antibodies were 5616·91 BAU/mL (95% CI 5296·49-5956·71) in the IG and 7298·22 BAU/mL (6739·41-7903·37) in the CG (p 1:100 at day 180 (19% and 22%, respectively). Interpretation: Titres of RBD antibodies decay over time, similar to homologous regimes. Our findings suggested that delaying administration of the second dose did not have a detrimental effect after vaccination and may have improved the response obtained. Lower neutralisation was observed against Omicron and Beta variants at day 180.Funded by Instituto de Salud Carlos III (ISCIII). AMB, AJC, JO, and JF are members of the VACCELERATE (European Corona Vaccine Trial Accelerator Platform) Network, which aims to facilitate and accelerate the design and implementation of COVID-19 phase 2 and 3 vaccine trials. JO is a member of the INsTRuCT (Innovative Training in Myeloid Regulatory Cell Therapy) Consortium, a network of European scientists from academia and industry focused on developing innovative immunotherapies. This work is funded by Instituto de Salud Carlos III, a Spanish public body assigned to the Ministry of Science and Innovation that manages and promotes public clinical research related to public health. The Spanish Clinical Trials Platform is a public network funded by the Instituto de Salud Carlos III (grant numbers PTC20/00018 and PT17/0017), the State Plan for Research, Development, and Innovation 2013−16, the State Plan for Scientific and Technical Research and Innovation 2017−20, and the Subdirectorate General for Evaluation and Promotion of Research, Instituto de Salud Carlos III, cofinanced with FEDER funds. CombiVacS was designed under the umbrella of the VACCELERATE project. VACCELER ATE and INsTRuCT received funding from the EU’s Horizon 2020 Research and Innovation Programme (grant agreement numbers 101037867 and 860003). The Instituto de Salud Carlos III is the Spanish partner in the VACCELERATE project. This work is partially funded by Institute of Health Carlos III (Instituto de Salud Carlos III − ISCIII −), (grants PI19CIII/00004 to JA and PI21CIII/00025 to MPO and JGP), and COVID-19 FUND (grants COV20/00679 and COV20/00072 to MPO and JA) and CIBERINFEC, co-financed by the European Regional Development Fund (FEDER) “A way to make Europe”. The authors thank all trial participants, the international data safety monitoring board (Appendix 1 p 23), and the trial steering committee (Appendix 1 pp 24−25). The authors thank Esther Prieto for editorial assistance and writing support (employed by Hospital Universitario La Paz; funded by the Instituto de Salud Carlos III, grant number PCT20/00018) and María Castillo-de la Osa (PEJ2018-004557-A) for excellent technical assistance.S

C3 glomerulopathy-associated CFHR1 mutation alters FHR oligomerization and complement regulation

C3 glomerulopathies (C3G) are a group of severe renal diseases with distinct patterns of glomerular inflammation and C3 deposition caused by complement dysregulation. Here we report the identification of a familial C3G-associated genomic mutation in the gene complement factor H–related 1 (CFHR1), which encodes FHR1. The mutation resulted in the duplication of the N-terminal short consensus repeats (SCRs) that are conserved in FHR2 and FHR5. We determined that native FHR1, FHR2, and FHR5 circulate in plasma as homo- and hetero-oligomeric complexes, the formation of which is likely mediated by the conserved N-terminal domain. In mutant FHR1, duplication of the N-terminal domain resulted in the formation of unusually large multimeric FHR complexes that exhibited increased avidity for the FHR1 ligands C3b, iC3b, and C3dg and enhanced competition with complement factor H (FH) in surface plasmon resonance (SPR) studies and hemolytic assays. These data revealed that FHR1, FHR2, and FHR5 organize a combinatorial repertoire of oligomeric complexes and demonstrated that changes in FHR oligomerization influence the regulation of complement activation. In summary, our identification and characterization of a unique CFHR1 mutation provides insights into the biology of the FHRs and contributes to our understanding of the pathogenic mechanisms underlying C3G

Análisis estructural y funcional de proteínas del complemento asociadas con patología

El sistema del complemento está constituido por un conjunto de proteínas plasmáticas y de membrana implicadas en la respuesta inmune innata frente a infecciones, y también en la modulación de la respuesta inmune adaptativa. El evento principal en la activación del complemento es la hidrólisis del componente C3 a C3b, a través de las convertasas de C3. Para evitar el daño en el tejido propio, tanto la formación de las convertasas como la presencia de C3b, están estrictamente reguladas. De esto se ocupan un conjunto de proteínas reguladoras estructural y funcionalmente relacionadas, que se localizan en un agrupamiento de genes conocido como RCA. La información disponible durante los últimos años, ha puesto de manifiesto cómo diversos factores de riesgo que afectan al sistema del complemento, están asociados con situaciones patológicas. El grupo de investigación donde se ha realizado esta tesis se centra principalmente en los componentes y los reguladores de la vía alternativa (AP) del complemento, y en entender las bases moleculares de enfermedades asociadas con esta vía, como son el síndrome hemolítico urémico atípico (aHUS), la enfermedad por depósitos densos (DDD) y la degeneración macular asociada a la edad (AMD). Estudios previos han demostrado que las mutaciones encontradas en genes de la AP (en reguladores como CFH, MCP y CFI; y componentes como CFB y C3) dan lugar a la activación incontrolada, y no específica de la AP, conduciendo a situaciones patológicas como aHUS o DDD. Por otro lado, se han hallado polimorfismos en estos genes que confieren riesgo o protección para estas enfermedades, y también para AMD, donde la asociación existente con ciertos polimorfismos es muy estrecha. Sin embargo, las consecuencias funcionales de la mayoría de estos polimorfismos es aún desconocida. La identificación de factores de riesgo en estos pacientes, así como la caracterización funcional de las alteraciones genéticas y el conocimiento de los mecanismos moleculares implicados en la patogénesis de estas enfermedades es por tanto fundamental

Genetics of atypical hemolytic uremic syndrome (aHUS)

29 p.-3 fig.Hemolytic uremic syndrome (HUS) is a rare, life-threatening disease characterized by thrombocytopenia, microangiopathic hemolytic anemia, and acute renal failure. The atypical form of HUS (aHUS), representing 5 to 10% of cases, lacks the association with infection by Shiga toxin producing Escherichia coli strains that characterizes the commonest clinical presentation of HUS. In the majority of aHUS cases, the disease results from the complement-mediated damage to the microvascular endothelium because of inherited defects in complement genes or autoantibodies against complement regulatory proteins. Incomplete penetrance of aHUS in carriers of mutations is common to all aHUS-associated complement genes and it is now established that the overall genetic predisposition to aHUS of an individual results from the combination of different inherited factors. Moreover, the patient's genotype influences the clinical evolution, the response to plasma therapies, and the recurrence after transplantation. Here, we describe the genetic component of aHUS, the lessons that we have learned from the functional characterization of the aHUS-associated mutations, and the benefits of a comprehensive genetic analysis of the patients. © 2014 by Thieme Medical Publishers, Inc.The work of the authors described in this review was supported by the Spanish Ministerio de Economia y Competitividad (SAF2011-26583), the Comunidad de Madrid (S2010/BMD-2316), the Fundación Renal Iñigo Alvarez de Toledo and the Seventh Framework Programme European Union Project EURenOmics (European Consortium for High-Throughtput Research in Rare Kidney Diseases).Peer Reviewe

Complement dysregulation and disease: from genes and proteins to diagnostics and drugs

57 p.-4 fig.2 tab.During the last decade, numerous studies have associated genetic variations in complement components and regulators with a number of chronic and infectious diseases. The functional characterization of these complement protein variants, in addition to recent structural advances in understanding of the assembly, activation and regulation of the AP C3 convertase, have provided important insights into the pathogenic mechanisms involved in some of these complement related disorders. This knowledge has identified potential targets for complement inhibitory therapies which are demonstrating efficacy and generating considerable expectation in changing the natural history of these diseases. Comprehensive understanding of the genetic and non-genetic risk factors contributing to these disorders will also result in targeting of the right patient groups in a stratified medicine approach through better diagnostics and individually tailored treatments, thereby improving management of patientsThe work of the authors described in this review was supported by the Wellcome Trust (068823; to CLH) and the MRC (G0701298; to CLH and BPM). SRdeC is supported by the Spanish Ministerio de Economia y Competitiviad (SAF2010-26583), the Communidad de Madrid (S2010/BMD-2316) and the Fundación Renal Iñigo Alvarez de ToledoPeer reviewe