Browsing by Author "Perrin, Richard"

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    Awareness of Genetic Risk in the Dominantly Inherited Alzheimer Network (DIAN)
    (Wiley, 2020-01) Aschenbrenner, Andrew J.; James, Bryan D.; McDade, Eric; Wang, Guoqiao; Lim, Yen Ying; Benzinger, Tammie L.S.; Cruchaga, Carlos; Goate, Alison; Xiong, Chengjie; Perrin, Richard; Buckles, Virginia; Allegri, Ricardo; Berman, Sarah B.; Chhatwal, Jasmeer P.; Fagan, Anne; Farlow, Martin; O'Connor, Antoinette; Ghetti, Bernardino; Graff-Radford, Neill; Goldman, Jill; Gräber, Susanne; Karch, Celeste M.; Lee, Jae-Hong; Levin, Johannes; Martins, Ralph N.; Masters, Colin; Mori, Hiroshi; Noble, James; Salloway, Stephen; Schofield, Peter; Morris, John C.; Bateman, Randall J.; Hassenstab, Jason; Neurology, School of Medicine
    Introduction: Although some members of families with autosomal dominant Alzheimer's disease mutations learn their mutation status, most do not. How knowledge of mutation status affects clinical disease progression is unknown. This study quantifies the influence of mutation awareness on clinical symptoms, cognition, and biomarkers. Methods: Mutation carriers and non-carriers from the Dominantly Inherited Alzheimer Network (DIAN) were stratified based on knowledge of mutation status. Rates of change on standard clinical, cognitive, and neuroimaging outcomes were examined. Results: Mutation knowledge had no associations with cognitive decline, clinical progression, amyloid deposition, hippocampal volume, or depression in either carriers or non-carriers. Carriers who learned their status mid-study had slightly higher levels of depression and lower cognitive scores. Discussion: Knowledge of mutation status does not affect rates of change on any measured outcome. Learning of status mid-study may confer short-term changes in cognitive functioning, or changes in cognition may influence the determination of mutation status.
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    Parenchymal border macrophages regulate the flow dynamics of the cerebrospinal fluid
    (Springer, 2022-11-09) Drieu, Antoine; Du, Siling; Storck, Steffen E.; Rustenhoven, Justin; Papadopoulos, Zachary; Dykstra, Taitea; Zhong, Fenghe; Kim, Kyungdeok; Blackburn, Susan; Mamuladze, Tornike; Harari, Oscar; Karch, Celeste M.; Bateman, Randall J.; Perrin, Richard; Farlow, Martin; Chhatwal, Jasmeer; Dominantly Inherited Alzheimer Network; Hu, Song; Randolph, Gwendalyn J.; Smirnov, Igor; Kipnis, Jonathan; Neurology, School of Medicine
    Macrophages are important players for the maintenance of tissue homeostasis1. Perivascular and leptomeningeal macrophages reside in close proximity to the central nervous system (CNS) parenchyma2, and their role in CNS physiology has not been well enough studied to date. Given their continuous interaction with the cerebrospinal fluid (CSF) and strategic positioning, we refer to these cells collectively as parenchymal border macrophages (PBMs). Here, we demonstrate that PBMs regulate CSF flow dynamics. We identify a subpopulation of PBMs expressing high levels of CD163 and Lyve1 (scavenger receptor proteins), located in close proximity to the brain arterial tree, and show that Lyve1+ PBMs regulate arterial motion that drives CSF flow. Pharmacological or genetic depletion of PBMs led to accumulation of extracellular matrix proteins, obstructing CSF access to perivascular spaces hence impairing CNS perfusion and clearance. Aging-associated alterations in PBMs and impairment of CSF dynamics were restored upon intracisternal injection of macrophage colony-stimulating growth factor (M-CSF). Human single-nuclei RNA sequencing data obtained from Alzheimer’s disease (AD) patients and healthy controls point to changes in phagocytosis/endocytosis and interferon-gamma (IFNγ) signaling on PBMs, pathways that are corroborated in a mouse AD model. Collectively, our results identify PBMs as novel cellular regulators of CSF flow dynamics, which could potentially be targeted pharmacologically to alleviate brain clearance deficits associated with aging and AD.
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    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 Medicine
    Cognitive 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.
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    Serum neurofilament dynamics predicts neurodegeneration and clinical progression in presymptomatic Alzheimer's disease
    (Nature Research, 2019-02) Preische, Oliver; Schultz, Stephanie A.; Apel, Anja; Kuhle, Jens; Kaeser, Stephan A.; Barro, Christian; Gräber, Susanne; Kuder-Buletta, Elke; LaFougere, Christian; Laske, Christoph; Vöglein, Jonathan; Levin, Johannes; Masters, Colin L.; Martins, Ralph; Schofield, Peter R.; Rossor, Martin N.; Graff-Radford, Neill R.; Salloway, Stephen; Ghetti, Bernardino; Ringman, John M.; Noble, James M.; Chhatwal, Jasmeer; Goate, Alison M.; Benzinger, Tammie L. S.; Morris, John C.; Bateman, Randall J.; Wang, Guoqiao; Fagan, Anne M.; McDade, Eric M.; Gordon, Brian A.; Jucker, Mathias; Alzheimer Network; Allegri, Ricardo; Amtashar, Fatima; Bateman, Randall; Benzinger, Tammie; Berman, Sarah; Bodge, Courtney; Brandon, Susan; Brooks, William; Buck, Jill; Buckles, Virginia; Chea, Sochenda; Chhatwal, Jasmeer; Chrem, Patricio; Chui, Helena; Cinco, Jake; Clifford, Jack; Cruchaga, Carlos; D’Mello, Mirelle; Donahue, Tamara; Douglas, Jane; Edigo, Noelia; Erekin-Taner, Nilufer; Fagan, Anne; Farlow, Marty; Farrar, Angela; Feldman, Howard; Flynn, Gigi; Fox, Nick; Franklin, Erin; Fujii, Hisako; Gant, Cortaiga; Gardener, Samantha; Ghetti, Bernardino; Goate, Alison; Goldman, Jill; Gordon, Brian; Graff-Radford, Neill; Gray, Julia; Gurney, Jenny; Hassenstab, Jason; Hirohara, Mie; Holtzman, David; Hornbeck, Russ; DiBari, Siri Houeland; Ikeuchi, Takeshi; Ikonomovic, Snezana; Jerome, Gina; Jucker, Mathias; Karch, Celeste; Kasuga, Kensaku; Kawarabayashi, Takeshi; Klunk, William; Koeppe, Robert; Kuder-Buletta, Elke; Laske, Christoph; Lee, Jae-Hong; Levin, Johannes; Marcus, Daniel; Martins, Ralph; Mason, Neal Scott; Masters, Colin; Maue-Dreyfus, Denise; McDade, Eric; Montoya, Lucy; Mori, Hiroshi; Morris, John; Nagamatsu, Akem; Neimeyer, Katie; Noble, James; Norton, Joanne; Perrin, Richard; Raichle, Marc; Ringman, John; Roh, Jee Hoon; Salloway, Stephen; Schofield, Peter; Shimada, Hiroyuki; Shiroto, Tomoyo; Shoji, Mikio; Sigurdson, Wendy; Sohrabi, Hamid; Sparks, Paige; Suzuki, Kazushi; Swisher, Laura; Taddei, Kevin; Wang, Jen; Wang, Peter; Weiner, Mike; Wolfsberger, Mary; Xiong, Chengjie; Xu, Xiong; Pathology and Laboratory Medicine, School of Medicine
    Neurofilament light chain (NfL) is a promising fluid biomarker of disease progression for various cerebral proteopathies. Here we leverage the unique characteristics of the Dominantly Inherited Alzheimer Network and ultrasensitive immunoassay technology to demonstrate that NfL levels in the cerebrospinal fluid (n = 187) and serum (n = 405) are correlated with one another and are elevated at the presymptomatic stages of familial Alzheimer's disease. Longitudinal, within-person analysis of serum NfL dynamics (n = 196) confirmed this elevation and further revealed that the rate of change of serum NfL could discriminate mutation carriers from non-mutation carriers almost a decade earlier than cross-sectional absolute NfL levels (that is, 16.2 versus 6.8 years before the estimated symptom onset). Serum NfL rate of change peaked in participants converting from the presymptomatic to the symptomatic stage and was associated with cortical thinning assessed by magnetic resonance imaging, but less so with amyloid-β deposition or glucose metabolism (assessed by positron emission tomography). Serum NfL was predictive for both the rate of cortical thinning and cognitive changes assessed by the Mini-Mental State Examination and Logical Memory test. Thus, NfL dynamics in serum predict disease progression and brain neurodegeneration at the early presymptomatic stages of familial Alzheimer's disease, which supports its potential utility as a clinically useful biomarker.