Multiancestry analysis of the HLA locus in Alzheimer’s and Parkinson’s diseases uncovers a shared adaptive immune response mediated by HLA-DRB1*04 subtypes

Across multiancestry groups, we analyzed Human Leukocyte Antigen (HLA) associations in over 176,000 individuals with Parkinson’s disease (PD) and Alzheimer’s disease (AD) versus controls. We demonstrate that the two diseases share the same protective association at the HLA locus. HLA-specific fine-mapping showed that hierarchical protective effects of HLA-DRB1*04 subtypes best accounted for the association, strongest with HLA-DRB1*04:04 and HLA-DRB1*04:07, and intermediary with HLA-DRB1*04:01 and HLA-DRB1*04:03. The same signal was associated with decreased neurofibrillary tangles in postmortem brains and was associated with reduced tau levels in cerebrospinal fluid and to a lower extent with increased Aβ42. Protective HLA-DRB1*04 subtypes strongly bound the aggregation-prone tau PHF6 sequence, however only when acetylated at a lysine (K311), a common posttranslational modification central to tau aggregation. An HLA-DRB1*04-mediated adaptive immune response decreases PD and AD risks, potentially by acting against tau, offering the possibility of therapeutic avenues

Estado actual de las colecciones zulianas del género Tabebuia s.l. (Angiospermae: Bignoniaceae) en los herbarios venezolanos

<p>Producto de la revisión de una buena parte de los herbarios nacionales <b>CAR</b> (Herbario Museo de Historia Natural La Salle, Fundación La Salle de Ciencias Naturales), <b>CORO </b>(Herbario del Departamento de Investigación, Instituto Universitario Tecnológico “Alonso Gamero”), <b>HERZU</b> (Herbario de la Universidad del Zulia “Omar Zambrano”), <b>HGR (</b>Herbario “Gladys de Rodríguez”, Universidad Pedagógica Experimental Libertador), <b>HMBLUZ</b> (Herbario del Museo de Biología de la Universidad del Zulia), <b>HRT </b>(Herbario Regional de Táchira “Juan José Pacheco”), <b>IPMY </b>(Herbario del Instituto Pedagógico de Maracay), <b>IVIC </b>(Herbario del Proyecto de Biomedicinas del Bosque Tropical, Instituto Venezolano de Investigaciones Científicas), <b>LUC (</b>Herbario “Helga Lindorf”, Universidad de Carabobo), <b>MERC (</b>Herbario de la Facultad de Ciencias, Universidad de los Andes), <b>MYF </b>(Herbario Víctor Manuel Ovalles”, Universidad Central de Venezuela), <b>PORT </b>(Herbario Universitario, BioCentro, Universidad Nacional Experimental de Los Llanos “Ezequiel Zamora”), <b>UCOB</b> (Herbario “José Casadiego”, Universidad Centroccidental Lisandro Alvarado) y <b>VEN </b>(Herbario Nacional de Venezuela), y con el fin de realizar la revisión taxonómica del género <i>Tabebuia</i> en el estado Zulia, presentamos un estudio curatorial de las muestras procedentes de dicha región. </p> <p>Los nueve (9) taxones registrados hasta ahora incluyeron ocho (8) especies y cuatro (4) subespecies (<i>T. billbergii </i>(Bureau & K. Schum.) Standl. subsp<i>. billbergii</i>, <i>T. capitata </i>(Bureau & K. Schum.) Sandwith, <i>T. chrysantha</i> (Jacq.) G. Nicholson subsp. <i>chrysantha</i>, <i>T. chrysea</i> S.F. Blake, <i>T. guayacan</i> (Seem.) Hemsl., <i>T. ochracea</i> subsp. <i>heterotricha</i> (A. DC.) A.H. Gentry, <i>T. ochracea</i> subsp. <i>neochrysantha </i>(A.H. Gentry) A.H. Gentry, <i>T. rosea</i> (Bertol.) A. DC. y <i>T. serratifolia</i> (Vahl) G. Nicolson).</p> <p>En total, contabilizamos 106 exsiccatas de las cuales tres (2,83%) están determinadas hasta nivel de género, 90 (84,90%) hasta especie y 13 (12,26%) hasta subespecie. Las especies con mayor registros de herbario son <i>T. billbergii </i>(27 pliegos), <i>T. chrysea </i>(22 pliegos) y <i>T. rosea </i>(17 pliegos). Los herbarios que presentaron mayor número de muestras fueron VEN (49 pliegos) y HMBLUZ (29 pliegos). Producto del análisis de los resultados obtenidos sugerimos realizar colecciones adicionales en ciertas áreas de la región, insuficientemente prospectadas, así como de ciertas especies, pobremente representadas en los herbarios.</p> <p>Este póster lo presentamos en las XIV Jornadas Científico Técnicas de la Facultad de Agronomía de LUZ, en Maracaibo, 14-17 de Octubre de 2014   </p> <p> </p

Towards a collaborative approach to the systematics of Ipomoea: A response to the “Rebuttal to (2786) Proposal to change the conserved type of Ipomoea, nom. cons. (Convolvulaceae)”.

A proposal to change the conserved type of was published in December 2020, and recommended by the Nomenclature Committee in 2023. This was done in the light of the possible negative consequences for a name change in the crop sweetpotato, which risk our proposal would significantly minimize. Recently, Muñoz‐Rodríguez &amp; al. have published a rebuttal to this proposal, which we respond to here. The objections raised by these authors focus as much on the expertise and credibility of our group of authors as on the merits of our arguments. In this “rebuttal to the rebuttal”, we respond to the scientific questions raised, highlight demonstrated misinterpretation of the specialised literature relevant to this discussion and counter the assertion that a reclassification of Ipomoeeae is impossible given existing evidence. While the currently recognised genera of Ipomoeeae are not all monophyletic, the proposal to change the conserved type of is a necessary step that will allow exploring an improved classification for the tribe Ipomoeeae, either in the form of a better recircumscription of the genera or an efficient infrageneric classification for . Previously published literature has not advocated for the integration of all genera into a single genus, as Muñoz‐Rodríguez and co‐authors have incorrectly suggested, and instead have recommended a reanalysis of the high morphological diversity of the group in the context of expanded phylogenetic studies, with the possible maintenance of some of the existing genera. We believe that, in a concerted collaborative approach and with the contribution of experts from different regions and scientific backgrounds, an improved classification of Ipomoeeae that integrates the principles of monophyly and diagnosability may soon be achieved, and until when some uncertainty may need to be accommodated, with the added reassurance that, regardless of the direction of future systematic rearrangements, the stability of the scientific name of sweetpotato would be preserved

Morichales, cananguchales y otros palmares inundables de Suramérica. Parte II: Colombia, Venezuela, Brasil, Perú, Bolivia, Paraguay, Uruguay y Argentina

El libro está dividido en cuatro partes. En la primera sección se incluye un análisis muy completo sobre el estado del conocimiento, uso y conservación de Mauritia flexuosa en Suramérica. En la segunda parte se consideran varios casos de estudio (11) sobre comunidades de plantas asociadas, demografía, polinizadores, aves y mamíferos relacionados, así como temas de manejo y ecoturismo en palmares de Mauritia flexuosa. La tercera sección incluye aportes de varios países sobre otros palmares, principalmente de Astrocaryum jauari, Butia odorata, B. paraguayensis, Copernicia alba, C. tectorum, Euterpe oleracea, Manicaria saccifera, Mauritiella aculeata y Roystonea oleracea. También se aporta información de 25 especies adicionales de palmas, incluyendo los usos, dinámica de poblaciones, biología reproductiva, florística de humedales asociados y conservación, entre otros aspectos. Por último, en la cuarta parte se dan las conclusiones y recomendaciones para la conservación de los palmares inundables en Suramérica.Bogotá, D. C

New insights into the genetic etiology of Alzheimer’s disease and related dementias

Characterization of the genetic landscape of Alzheimer’s disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/‘proxy’ AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

New insights into the genetic etiology of Alzheimer’s disease and related dementias

Characterization of the genetic landscape of Alzheimer’s disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/‘proxy’ AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele