Browsing by Author "Ewers, Michael"
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Item Alzheimer's Disease and Small Vessel Disease Differentially Affect White Matter Microstructure(Wiley, 2024) Tranfa, Mario; Lorenzini, Luigi; Collij, Lyduine E.; Vállez García, David; Ingala, Silvia; Pontillo, Giuseppe; Pieperhoff, Leonard; Maranzano, Alessio; Wolz, Robin; Haller, Sven; Blennow, Kaj; Frisoni, Giovanni; Sudre, Carole H.; Chételat, Gael; Ewers, Michael; Payoux, Pierre; Waldman, Adam; Martinez-Lage, Pablo; Schwarz, Adam J.; Ritchie, Craig W.; Wardlaw, Joanna M.; Domingo Gispert, Juan; Brunetti, Arturo; Mutsaerts, Henk J. M. M.; Meije Wink, Alle; Barkhof, Frederik; Radiology and Imaging Sciences, School of MedicineObjective: Alzheimer's disease (AD) and cerebral small vessel disease (cSVD), the two most common causes of dementia, are characterized by white matter (WM) alterations diverging from the physiological changes occurring in healthy aging. Diffusion tensor imaging (DTI) is a valuable tool to quantify WM integrity non-invasively and identify the determinants of such alterations. Here, we investigated main effects and interactions of AD pathology, APOE-ε4, cSVD, and cardiovascular risk on spatial patterns of WM alterations in non-demented older adults. Methods: Within the prospective European Prevention of Alzheimer's Dementia study, we selected 606 participants (64.9 ± 7.2 years, 376 females) with baseline cerebrospinal fluid samples of amyloid β1-42 and p-Tau181 and MRI scans, including DTI scans. Longitudinal scans (mean follow-up time = 1.3 ± 0.5 years) were obtained in a subset (n = 223). WM integrity was assessed by extracting fractional anisotropy and mean diffusivity in relevant tracts. To identify the determinants of WM disruption, we performed a multimodel inference to identify the best linear mixed-effects model for each tract. Results: AD pathology, APOE-ε4, cSVD burden, and cardiovascular risk were all associated with WM integrity within several tracts. While limbic tracts were mainly impacted by AD pathology and APOE-ε4, commissural, associative, and projection tract integrity was more related to cSVD burden and cardiovascular risk. AD pathology and cSVD did not show any significant interaction effect. Interpretation: Our results suggest that AD pathology and cSVD exert independent and spatially different effects on WM microstructure, supporting the role of DTI in disease monitoring and suggesting independent targets for preventive medicine approaches.Item Amyloid-associated increases in soluble tau relate to tau aggregation rates and cognitive decline in early Alzheimer’s disease(Springer Nature, 2022-11-04) Pichet Binette, Alexa; Franzmeier, Nicolai; Spotorno, Nicola; Ewers, Michael; Brendel, Matthias; Biel, Davina; Alzheimer’s Disease Neuroimaging Initiative; Strandberg, Olof; Janelidze, Shorena; Palmqvist, Sebastian; Mattsson-Carlgren, Niklas; Smith, Ruben; Stomrud, Erik; Ossenkoppele, Rik; Hansson, Oskar; Radiology and Imaging Sciences, School of MedicineFor optimal design of anti-amyloid-β (Aβ) and anti-tau clinical trials, we need to better understand the pathophysiological cascade of Aβ- and tau-related processes. Therefore, we set out to investigate how Aβ and soluble phosphorylated tau (p-tau) relate to the accumulation of tau aggregates assessed with PET and subsequent cognitive decline across the Alzheimer's disease (AD) continuum. Using human cross-sectional and longitudinal neuroimaging and cognitive assessment data, we show that in early stages of AD, increased concentration of soluble CSF p-tau is strongly associated with accumulation of insoluble tau aggregates across the brain, and CSF p-tau levels mediate the effect of Aβ on tau aggregation. Further, higher soluble p-tau concentrations are mainly related to faster accumulation of tau aggregates in the regions with strong functional connectivity to individual tau epicenters. In this early stage, higher soluble p-tau concentrations is associated with cognitive decline, which is mediated by faster increase of tau aggregates. In contrast, in AD dementia, when Aβ fibrils and soluble p-tau levels have plateaued, cognitive decline is related to the accumulation rate of insoluble tau aggregates. Our data suggest that therapeutic approaches reducing soluble p-tau levels might be most favorable in early AD, before widespread insoluble tau aggregates.Item Axonal damage and inflammation response are biological correlates of decline in small-world values: a cohort study in autosomal dominant Alzheimer's disease(Oxford University Press, 2024-10-09) Vermunt, Lisa; Sutphen, Courtney L.; Dicks, Ellen; de Leeuw, Diederick M.; Allegri, Ricardo F.; Berman, Sarah B.; Cash, David M.; Chhatwal, Jasmeer P.; Cruchaga, Carlos; Day, Gregory S.; Ewers, Michael; Farlow, Martin R.; Fox, Nick C.; Ghetti, Bernardino; Graff-Radford, Neill R.; Hassenstab, Jason; Jucker, Mathias; Karch, Celeste M.; Kuhle, Jens; Laske, Christoph; Levin, Johannes; Masters, Colin L.; McDade, Eric; Mori, Hiroshi; Morris, John C.; Perrin, Richard J.; Preische, Oliver; Schofield, Peter R.; Suárez-Calvet, Marc; Xiong, Chengjie; Scheltens, Philip; Teunissen, Charlotte E.; Visser, Pieter Jelle; Bateman, Randall J.; Benzinger, Tammie L. S.; Fagan, Anne M.; Gordon, Brian A.; Tijms, Betty M.; Pathology and Laboratory Medicine, School of MedicineThe grey matter of the brain develops and declines in coordinated patterns during the lifespan. Such covariation patterns of grey matter structure can be quantified as grey matter networks, which can be measured with magnetic resonance imaging. In Alzheimer's disease, the global organization of grey matter networks becomes more random, which is captured by a decline in the small-world coefficient. Such decline in the small-world value has been robustly associated with cognitive decline across clinical stages of Alzheimer's disease. The biological mechanisms causing this decline in small-world values remain unknown. Cerebrospinal fluid (CSF) protein biomarkers are available for studying diverse pathological mechanisms in humans and can provide insight into decline. We investigated the relationships between 10 CSF proteins and small-world coefficient in mutation carriers (N = 219) and non-carriers (N = 136) of the Dominantly Inherited Alzheimer Network Observational study. Abnormalities in Amyloid beta, Tau, synaptic (Synaptosome associated protein-25, Neurogranin) and neuronal calcium-sensor protein (Visinin-like protein-1) preceded loss of small-world coefficient by several years, while increased levels in CSF markers for inflammation (Chitinase-3-like protein 1) and axonal injury (Neurofilament light) co-occurred with decreasing small-world values. This suggests that axonal loss and inflammation play a role in structural grey matter network changes.Item Implementation of Subjective Cognitive Decline criteria in research studies(Elsevier, 2017-03) Molinuevo, José L; Rabin, Laura A.; Amariglio, Rebecca; Buckley, Rachel; Dubois, Bruno; Ellis, Kathryn A.; Ewers, Michael; Hampel, Harald; Klöppel, Stefan; Rami, Lorena; Reisberg, Barry; Saykin, Andrew J.; Sikkes, Sietske; Smart, Colette M.; Snitz, Beth E.; Sperling, Reisa; van der Flier, Wiesje M.; Wagner, Michael; Jessen, Frank; Radiology and Imaging Sciences, School of MedicineINTRODUCTION Subjective Cognitive Decline (SCD) manifesting prior to clinical impairment could serve as a target population for early intervention trials in Alzheimer’s disease (AD). A working group, the Subjective Cognitive Decline Initiative (SCD-I), published SCD research criteria in the context of preclinical AD. To successfully apply them, a number of issues regarding assessment and implementation of SCD needed to be addressed. METHODS Members of the SCD-I met to identify and agree upon topics relevant to SCD criteria operationalization in research settings. Initial ideas and recommendations were discussed with other SCD-I working group members and modified accordingly. RESULTS Topics included SCD inclusion and exclusion criteria, together with the informant’s role in defining SCD presence and the impact of demographic factors. DISCUSSION Recommendations for the operationalization of SCD in differing research settings, with the aim of harmonization of SCD measurement across studies are proposed, to enhance comparability and generalizability across studies.Item KL-VS heterozygosity is associated with lower amyloid-dependent tau accumulation and memory impairment in Alzheimer’s disease(Springer Nature, 2021-06-22) Neitzel, Julia; Franzmeier, Nicolai; Rubinski, Anna; Dichgans, Martin; Brendel, Matthias; Alzheimer’s Disease Neuroimaging Initiative (ADNI); Malik, Rainer; Ewers, Michael; Radiology and Imaging Sciences, School of MedicineKlotho-VS heterozygosity (KL-VShet) is associated with reduced risk of Alzheimer's disease (AD). However, whether KL-VShet is associated with lower levels of pathologic tau, i.e., the key AD pathology driving neurodegeneration and cognitive decline, is unknown. Here, we assessed the interaction between KL-VShet and levels of beta-amyloid, a key driver of tau pathology, on the levels of PET-assessed neurofibrillary tau in 551 controls and patients across the AD continuum. KL-VShet showed lower cross-sectional and longitudinal increase in tau-PET per unit increase in amyloid-PET when compared to that of non-carriers. This association of KL-VShet on tau-PET was stronger in Klotho mRNA-expressing brain regions mapped onto a gene expression atlas. KL-VShet was related to better memory functions in amyloid-positive participants and this association was mediated by lower tau-PET. Amyloid-PET levels did not differ between KL-VShet carriers versus non-carriers. Together, our findings provide evidence to suggest a protective role of KL-VShet against amyloid-related tau pathology and tau-related memory impairments in elderly humans at risk of AD dementia.Item Leveraging large multi-center cohorts of Alzheimer disease endophenotypes to understand the role of Klotho heterozygosity on disease risk(PLOS, 2022-05-26) Ali, Muhammad; Sung, Yun Ju; Wang, Fengxian; Fernández, Maria V.; Morris, John C.; Fagan, Anne M.; Blennow, Kaj; Zetterberg, Henrik; Heslegrave, Amanda; Johansson, Per M.; Svensson, Johan; Nellgård, Bengt; Lleó, Alberto; Alcolea, Daniel; Clarimon, Jordi; Rami, Lorena; Molinuevo, José Luis; Suárez-Calvet, Marc; Morenas-Rodríguez, Estrella; Kleinberger, Gernot; Haass, Christian; Ewers, Michael; Levin, Johannes; Farlow, Martin R.; Perrin, Richard J.; Alzheimer’s Disease Neuroimaging Initiative (ADNI); Dominantly Inherited Alzheimer Network (DIAN); Cruchaga, Carlos; Neurology, School of MedicineTwo genetic variants in strong linkage disequilibrium (rs9536314 and rs9527025) in the Klotho (KL) gene, encoding a transmembrane protein, implicated in longevity and associated with brain resilience during normal aging, were recently shown to be associated with Alzheimer disease (AD) risk in cognitively normal participants who are APOE ε4 carriers. Specifically, the participants heterozygous for this variant (KL-SVHET+) showed lower risk of developing AD. Furthermore, a neuroprotective effect of KL-VSHET+ has been suggested against amyloid burden for cognitively normal participants, potentially mediated via the regulation of redox pathways. However, inconsistent associations and a smaller sample size of existing studies pose significant hurdles in drawing definitive conclusions. Here, we performed a well-powered association analysis between KL-VSHET+ and five different AD endophenotypes; brain amyloidosis measured by positron emission tomography (PET) scans (n = 5,541) or cerebrospinal fluid Aβ42 levels (CSF; n = 5,093), as well as biomarkers associated with tau pathology: the CSF Tau (n = 5,127), phosphorylated Tau (pTau181; n = 4,778) and inflammation: CSF soluble triggering receptor expressed on myeloid cells 2 (sTREM2; n = 2,123) levels. Our results found nominally significant associations of KL-VSHET+ status with biomarkers for brain amyloidosis (e.g., CSF Aβ positivity; odds ratio [OR] = 0.67 [95% CI, 0.55-0.78], β = 0.72, p = 0.007) and tau pathology (e.g., biomarker positivity for CSF Tau; OR = 0.39 [95% CI, 0.19-0.77], β = -0.94, p = 0.007, and pTau; OR = 0.50 [95% CI, 0.27-0.96], β = -0.68, p = 0.04) in cognitively normal participants, 60-80 years old, who are APOE e4-carriers. Our work supports previous findings, suggesting that the KL-VSHET+ on an APOE ε4 genotype background may modulate Aβ and tau pathology, thereby lowering the intensity of neurodegeneration and incidence of cognitive decline in older controls susceptible to AD.Item New insights into the genetic etiology of Alzheimer's disease and related dementias(Springer Nature, 2022) Bellenguez, Céline; Küçükali, Fahri; Jansen, Iris E.; Kleineidam, Luca; Moreno-Grau, Sonia; Amin, Najaf; Naj, Adam C.; Campos-Martin, Rafael; Grenier-Boley, Benjamin; Andrade, Victor; Holmans, Peter A.; Boland, Anne; Damotte, Vincent; van der Lee, Sven J.; Costa, Marcos R.; Kuulasmaa, Teemu; Yang, Qiong; de Rojas, Itziar; Bis, Joshua C.; Yaqub, Amber; Prokic, Ivana; Chapuis, Julien; Ahmad, Shahzad; Giedraitis, Vilmantas; Aarsland, Dag; Garcia-Gonzalez, Pablo; Abdelnour, Carla; Alarcón-Martín, Emilio; Alcolea, Daniel; Alegret, Montserrat; Alvarez, Ignacio; Álvarez, Victoria; Armstrong, Nicola J.; Tsolaki, Anthoula; Antúnez, Carmen; Appollonio, Ildebrando; Arcaro, Marina; Archetti, Silvana; Arias Pastor, Alfonso; Arosio, Beatrice; Athanasiu, Lavinia; Bailly, Henri; Banaj, Nerisa; Baquero, Miquel; Barral, Sandra; Beiser, Alexa; Belén Pastor, Ana; Below, Jennifer E.; Benchek, Penelope; Benussi, Luisa; Berr, Claudine; Besse, Céline; Bessi, Valentina; Binetti, Giuliano; Bizarro, Alessandra; Blesa, Rafael; Boada, Mercè; Boerwinkle, Eric; Borroni, Barbara; Boschi, Silvia; Bossù, Paola; Bråthen, Geir; Bressler, Jan; Bresner, Catherine; Brodaty, Henry; Brookes, Keeley J.; Brusco, Luis Ignacio; Buiza-Rueda, Dolores; Bûrger, Katharina; Burholt, Vanessa; Bush, William S.; Calero, Miguel; Cantwell, Laura B.; Chene, Geneviève; Chung, Jaeyoon; Cuccaro, Michael L.; Carracedo, Ángel; Cecchetti, Roberta; Cervera-Carles, Laura; Charbonnier, Camille; Chen, Hung-Hsin; Chillotti, Caterina; Ciccone, Simona; Claassen, Jurgen A. H. R.; Clark, Christopher; Conti, Elisa; Corma-Gómez, Anaïs; Costantini, Emanuele; Custodero, Carlo; Daian, Delphine; Dalmasso, Maria Carolina; Daniele, Antonio; Dardiotis, Efthimios; Dartigues, Jean-François; de Deyn, Peter Paul; de Paiva Lopes, Katia; de Witte, Lot D.; Debette, Stéphanie; Deckert, Jürgen; Del Ser, Teodoro; Denning, Nicola; DeStefano, Anita; Dichgans, Martin; Diehl-Schmid, Janine; Diez-Fairen, Mónica; Dionigi Rossi, Paolo; Djurovic, Srdjan; Duron, Emmanuelle; Düzel, Emrah; Dufouil, Carole; Eiriksdottir, Gudny; Engelborghs, Sebastiaan; Escott-Price, Valentina; Espinosa, Ana; Ewers, Michael; Faber, Kelley M.; Fabrizio, Tagliavini; Fallgaard Nielsen, Sune; Fardo, David W.; Farotti, Lucia; Fenoglio, Chiara; Fernández-Fuertes, Marta; Ferrari, Raffaele; Ferreira, Catarina B.; Ferri, Evelyn; Fin, Bertrand; Fischer, Peter; Fladby, Tormod; Fließbach, Klaus; Fongang, Bernard; Fornage, Myriam; Fortea, Juan; Foroud, Tatiana M.; Fostinelli, Silvia; Fox, Nick C.; Franco-Macías, Emlio; Bullido, María J.; Frank-García, Ana; Froelich, Lutz; Fulton-Howard, Brian; Galimberti, Daniela; García-Alberca, Jose Maria; García-González, Pablo; Garcia-Madrona, Sebastian; Garcia-Ribas, Guillermo; Ghidoni, Roberta; Giegling, Ina; Giorgio, Giaccone; Goate, Alison M.; Goldhardt, Oliver; Gomez-Fonseca, Duber; González-Pérez, Antonio; Graff, Caroline; Grande, Giulia; Green, Emma; Grimmer, Timo; Grünblatt, Edna; Grunin, Michelle; Gudnason, Vilmundur; Guetta-Baranes, Tamar; Haapasalo, Annakaisa; Hadjigeorgiou, Georgios; Haines, Jonathan L.; Hamilton-Nelson, Kara L.; Hampel, Harald; Hanon, Olivier; Hardy, John; Hartmann, Annette M.; Hausner, Lucrezia; Harwood, Janet; Heilmann-Heimbach, Stefanie; Helisalmi, Seppo; Heneka, Michael T.; Hernández, Isabel; Herrmann, Martin J.; Hoffmann, Per; Holmes, Clive; Holstege, Henne; Huerto Vilas, Raquel; Hulsman, Marc; Humphrey, Jack; Jan Biessels, Geert; Jian, Xueqiu; Johansson, Charlotte; Jun, Gyungah R.; Kastumata, Yuriko; Kauwe, John; Kehoe, Patrick G.; Kilander, Lena; Kinhult Ståhlbom, Anne; Kivipelto, Miia; Koivisto, Anne; Kornhuber, Johannes; Kosmidis, Mary H.; Kukull, Walter A.; Kuksa, Pavel P.; Kunkle, Brian W.; Kuzma, Amanda B.; Lage, Carmen; Laukka, Erika J.; Launer, Lenore; Lauria, Alessandra; Lee, Chien-Yueh; Lehtisalo, Jenni; Lerch, Ondrej; Lleó, Alberto; Longstreth, William, Jr.; Lopez, Oscar; Lopez de Munain, Adolfo; Love, Seth; Löwemark, Malin; Luckcuck, Lauren; Lunetta, Kathryn L.; Ma, Yiyi; Macías, Juan; MacLeod, Catherine A.; Maier, Wolfgang; Mangialasche, Francesca; Spallazzi, Marco; Marquié, Marta; Marshall, Rachel; Martin, Eden R.; Martín Montes, Angel; Martínez Rodríguez, Carmen; Masullo, Carlo; Mayeux, Richard; Mead, Simon; Mecocci, Patrizia; Medina, Miguel; Meggy, Alun; Mehrabian, Shima; Mendoza, Silvia; Menéndez-González, Manuel; Mir, Pablo; Moebus, Susanne; Mol, Merel; Molina-Porcel, Laura; Montrreal, Laura; Morelli, Laura; Moreno, Fermin; Morgan, Kevin; Mosley, Thomas; Nöthen, Markus M.; Muchnik, Carolina; Mukherjee, Shubhabrata; Nacmias, Benedetta; Ngandu, Tiia; Nicolas, Gael; Nordestgaard, Børge G.; Olaso, Robert; Orellana, Adelina; Orsini, Michela; Ortega, Gemma; Padovani, Alessandro; Paolo, Caffarra; Papenberg, Goran; Parnetti, Lucilla; Pasquier, Florence; Pastor, Pau; Peloso, Gina; Pérez-Cordón, Alba; Pérez-Tur, Jordi; Pericard, Pierre; Peters, Oliver; Pijnenburg, Yolande A. L.; Pineda, Juan A.; Piñol-Ripoll, Gerard; Pisanu, Claudia; Polak, Thomas; Popp, Julius; Posthuma, Danielle; Priller, Josef; Puerta, Raquel; Quenez, Olivier; Quintela, Inés; Qvist Thomassen, Jesper; Rábano, Alberto; Rainero, Innocenzo; Rajabli, Farid; Ramakers, Inez; Real, Luis M.; Reinders, Marcel J. T.; Reitz, Christiane; Reyes-Dumeyer, Dolly; Ridge, Perry; Riedel-Heller, Steffi; Riederer, Peter; Roberto, Natalia; Rodriguez-Rodriguez, Eloy; Rongve, Arvid; Rosas Allende, Irene; Rosende-Roca, Maitée; Royo, Jose Luis; Rubino, Elisa; Rujescu, Dan; Sáez, María Eugenia; Sakka, Paraskevi; Saltvedt, Ingvild; Sanabria, Ángela; Sánchez-Arjona, María Bernal; Sanchez-Garcia, Florentino; Sánchez Juan, Pascual; Sánchez-Valle, Raquel; Sando, Sigrid B.; Sarnowski, Chloé; Satizabal, Claudia L.; Scamosci, Michela; Scarmeas, Nikolaos; Scarpini, Elio; Scheltens, Philip; Scherbaum, Norbert; Scherer, Martin; Schmid, Matthias; Schneider, Anja; Schott, Jonathan M.; Selbæk, Geir; Seripa, Davide; Serrano, Manuel; Sha, Jin; Shadrin, Alexey A.; Skrobot, Olivia; Slifer, Susan; Snijders, Gijsje J. L.; Soininen, Hilkka; Solfrizzi, Vincenzo; Solomon, Alina; Song, Yeunjoo; Sorbi, Sandro; Sotolongo-Grau, Oscar; Spalletta, Gianfranco; Spottke, Annika; Squassina, Alessio; Stordal, Eystein; Tartan, Juan Pablo; Tárraga, Lluís; Tesí, Niccolo; Thalamuthu, Anbupalam; Thomas, Tegos; Tosto, Giuseppe; Traykov, Latchezar; Tremolizzo, Lucio; Tybjærg-Hansen, Anne; Uitterlinden, Andre; Ullgren, Abbe; Ulstein, Ingun; Valero, Sergi; Valladares, Otto; Van Broeckhoven, Christine; Vance, Jeffery; Vardarajan, Badri N.; van der Lugt, Aad; Van Dongen, Jasper; van Rooij, Jeroen; van Swieten, John; Vandenberghe, Rik; Verhey, Frans; Vidal, Jean-Sébastien; Vogelgsang, Jonathan; Vyhnalek, Martin; Wagner, Michael; Wallon, David; Wang, Li-San; Wang, Ruiqi; Weinhold, Leonie; Wiltfang, Jens; Windle, Gill; Woods, Bob; Yannakoulia, Mary; Zare, Habil; Zhao, Yi; Zhang, Xiaoling; Zhu, Congcong; Zulaica, Miren; EADB; GR@ACE; DEGESCO; EADI; GERAD; Demgene; FinnGen; ADGC; CHARGE; Farrer, Lindsay A.; Psaty, Bruce M.; Ghanbari, Mohsen; Raj, Towfique; Sachdev, Perminder; Mather, Karen; Jessen, Frank; Ikram, M. Arfan; de Mendonça, Alexandre; Hort, Jakub; Tsolaki, Magda; Pericak-Vance, Margaret A.; Amouyel, Philippe; Williams, Julie; Frikke-Schmidt, Ruth; Clarimon, Jordi; Deleuze, Jean-François; Rossi, Giacomina; Seshadri, Sudha; Andreassen, Ole A.; Ingelsson, Martin; Hiltunen, Mikko; Sleegers, Kristel; Schellenberg, Gerard D.; van Duijn, Cornelia M.; Sims, Rebecca; van der Flier, Wiesje M.; Ruiz, Agustín; Ramirez, Alfredo; Lambert, Jean-Charles; Medical and Molecular Genetics, School of MedicineCharacterization 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.Item Segregation of functional networks is associated with cognitive resilience in Alzheimer's disease(Oxford University Press, 2021) Ewers, Michael; Luan, Ying; Frontzkowski, Lukas; Neitzel, Julia; Rubinski, Anna; Dichgans, Martin; Hassenstab, Jason; Gordon, Brian A.; Chhatwal, Jasmeer P.; Levin, Johannes; Schofield, Peter; Benzinger, Tammie L.S; Morris, John C.; Goate, Alison; Karch, Celeste M.; Fagan, Anne M.; McDade, Eric; Allegri, Ricardo; Berman, Sarah; Chui, Helena; Cruchaga, Carlos; Farlow, Marty; Graff-Radford, Neill; Jucker, Mathias; Lee, Jae-Hong; Martins, Ralph N.; Mori, Hiroshi; Perrin, Richard; Xiong, Chengjie; Rossor, Martin; Fox, Nick C.; O’Connor, Antoinette; Salloway, Stephen; Danek, Adrian; Buerger, Katharina; Bateman, Randall J.; Habeck, Christian; Stern, Yaakov; Franzmeier, Nicolai; Alzheimer’s Disease Neuroimaging Initiative; Dominantly Inherited Alzheimer Network; Neurology, School of MedicineCognitive resilience is an important modulating factor of cognitive decline in Alzheimer's disease, but the functional brain mechanisms that support cognitive resilience remain elusive. Given previous findings in normal ageing, we tested the hypothesis that higher segregation of the brain's connectome into distinct functional networks represents a functional mechanism underlying cognitive resilience in Alzheimer's disease. Using resting-state functional MRI, we assessed both resting-state functional MRI global system segregation, i.e. the balance of between-network to within-network connectivity, and the alternate index of modularity Q as predictors of cognitive resilience. We performed all analyses in two independent samples for validation: (i) 108 individuals with autosomal dominantly inherited Alzheimer's disease and 71 non-carrier controls; and (ii) 156 amyloid-PET-positive subjects across the spectrum of sporadic Alzheimer's disease and 184 amyloid-negative controls. In the autosomal dominant Alzheimer's disease sample, disease severity was assessed by estimated years from symptom onset. In the sporadic Alzheimer's sample, disease stage was assessed by temporal lobe tau-PET (i.e. composite across Braak stage I and III regions). In both samples, we tested whether the effect of disease severity on cognition was attenuated at higher levels of functional network segregation. For autosomal dominant Alzheimer's disease, we found higher functional MRI-assessed system segregation to be associated with an attenuated effect of estimated years from symptom onset on global cognition (P = 0.007). Similarly, for patients with sporadic Alzheimer's disease, higher functional MRI-assessed system segregation was associated with less decrement in global cognition (P = 0.001) and episodic memory (P = 0.004) per unit increase of temporal lobe tau-PET. Confirmatory analyses using the alternate index of modularity Q revealed consistent results. In conclusion, higher segregation of functional connections into distinct large-scale networks supports cognitive resilience in Alzheimer's disease.Item Serum neurofilament light chain levels are associated with white matter integrity in autosomal dominant Alzheimer's disease(Elsevier, 2020-08-01) Schultz, Stephanie A.; Strain, Jeremy F.; Adedokun, Adedamola; Wang, Qing; Preische, Oliver; Kuhle, Jens; Flores, Shaney; Keefe, Sarah; Dincer, Aylin; Ances, Beau M.; Berman, Sarah B.; Brickman, Adam M.; Cash, David M.; Chhatwal, Jasmeer; Cruchaga, Carlos; Ewers, Michael; Fox, Nick N.; Ghetti, Bernardino; Goate, Alison; Graff-Radford, Neill R.; Hassenstab, Jason J.; Hornbeck, Russ; Jack, Clifford; Johnson, Keith; Joseph-Mathurin, Nelly; Karch, Celeste M.; Koeppe, Robert A.; Lee, Athene K. W.; Levin, Johannes; Masters, Colin; McDade, Eric; Perrin, Richard J.; Rowe, Christopher C.; Salloway, Stephen; Saykin, Andrew J.; Sperling, Reisa; Su, Yi; Villemagne, Victor L.; Vöglein, Jonathan; Weiner, Michael; Xiong, Chengjie; Fagan, Anne M.; Morris, John C.; Bateman, Randall J.; Benzinger, Tammie L. S.; Jucker, Mathias; Gordon, Brian A.; Pathology and Laboratory Medicine, School of MedicineNeurofilament light chain (NfL) is a protein that is selectively expressed in neurons. Increased levels of NfL measured in either cerebrospinal fluid or blood is thought to be a biomarker of neuronal damage in neurodegenerative diseases. However, there have been limited investigations relating NfL to the concurrent measures of white matter (WM) decline that it should reflect. White matter damage is a common feature of Alzheimer's disease. We hypothesized that serum levels of NfL would associate with WM lesion volume and diffusion tensor imaging (DTI) metrics cross-sectionally in 117 autosomal dominant mutation carriers (MC) compared to 84 non-carrier (NC) familial controls as well as in a subset (N = 41) of MC with longitudinal NfL and MRI data. In MC, elevated cross-sectional NfL was positively associated with WM hyperintensity lesion volume, mean diffusivity, radial diffusivity, and axial diffusivity and negatively with fractional anisotropy. Greater change in NfL levels in MC was associated with larger changes in fractional anisotropy, mean diffusivity, and radial diffusivity, all indicative of reduced WM integrity. There were no relationships with NfL in NC. Our results demonstrate that blood-based NfL levels reflect WM integrity and supports the view that blood levels of NfL are predictive of WM damage in the brain. This is a critical result in improving the interpretability of NfL as a marker of brain integrity, and for validating this emerging biomarker for future use in clinical and research settings across multiple neurodegenerative diseases.