Browsing by Author "Dykstra, Taitea"

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    Meningeal lymphatics affect microglia responses and anti-Aβ immunotherapy
    (Springer Nature, 2021) Da Mesquita, Sandro; Papadopoulos, Zachary; Dykstra, Taitea; Brase, Logan; Farias, Fabiana Geraldo; Wall, Morgan; Jiang, Hong; Kodira, Chinnappa Dilip; de Lima, Kalil Alves; Herz, Jasmin; Louveau, Antoine; Goldman, Dylan H.; Salvador, Andrea Francesca; Onengut-Gumuscu, Suna; Farber, Emily; Dabhi, Nisha; Kennedy, Tatiana; Milam, Mary Grace; Baker, Wendy; Smirnov, Igor; Rich, Stephen S.; Dominantly Inherited Alzheimer Network; Benitez, Bruno A.; Karch, Celeste M.; Perrin, Richard J.; Farlow, Martin; Chhatwal, Jasmeer P.; Holtzman, David M.; Cruchaga, Carlos; Harari, Oscar; Kipnis, Jonathan; Neurology, School of Medicine
    Alzheimer's disease (AD) is the most prevalent cause of dementia1. Although there is no effective treatment for AD, passive immunotherapy with monoclonal antibodies against amyloid beta (Aβ) is a promising therapeutic strategy2,3. Meningeal lymphatic drainage has an important role in the accumulation of Aβ in the brain4, but it is not known whether modulation of meningeal lymphatic function can influence the outcome of immunotherapy in AD. Here we show that ablation of meningeal lymphatic vessels in 5xFAD mice (a mouse model of amyloid deposition that expresses five mutations found in familial AD) worsened the outcome of mice treated with anti-Aβ passive immunotherapy by exacerbating the deposition of Aβ, microgliosis, neurovascular dysfunction, and behavioural deficits. By contrast, therapeutic delivery of vascular endothelial growth factor C improved clearance of Aβ by monoclonal antibodies. Notably, there was a substantial overlap between the gene signature of microglia from 5xFAD mice with impaired meningeal lymphatic function and the transcriptional profile of activated microglia from the brains of individuals with AD. Overall, our data demonstrate that impaired meningeal lymphatic drainage exacerbates the microglial inflammatory response in AD and that enhancement of meningeal lymphatic function combined with immunotherapies could lead to better clinical outcomes.
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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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    Single-nucleus RNA-sequencing of autosomal dominant Alzheimer disease and risk variant carriers
    (Springer Nature, 2023-04-21) Brase, Logan; You, Shih-Feng; D'Oliveira Albanus, Ricardo; Del-Aguila, Jorge L.; Dai, Yaoyi; Novotny, Brenna C.; Soriano-Tarraga, Carolina; Dykstra, Taitea; Fernandez, Maria Victoria; Budde, John P.; Bergmann, Kristy; Morris, John C.; Bateman, Randall J.; Perrin, Richard J.; McDade, Eric; Xiong, Chengjie; Goate, Alison M.; Farlow, Martin; Dominantly Inherited Alzheimer Network (DIAN); Sutherland, Greg T.; Kipnis, Jonathan; Karch, Celeste M.; Benitez, Bruno A.; Harari, Oscar; Neurology, School of Medicine
    Genetic studies of Alzheimer disease (AD) have prioritized variants in genes related to the amyloid cascade, lipid metabolism, and neuroimmune modulation. However, the cell-specific effect of variants in these genes is not fully understood. Here, we perform single-nucleus RNA-sequencing (snRNA-seq) on nearly 300,000 nuclei from the parietal cortex of AD autosomal dominant (APP and PSEN1) and risk-modifying variant (APOE, TREM2 and MS4A) carriers. Within individual cell types, we capture genes commonly dysregulated across variant groups. However, specific transcriptional states are more prevalent within variant carriers. TREM2 oligodendrocytes show a dysregulated autophagy-lysosomal pathway, MS4A microglia have dysregulated complement cascade genes, and APOEε4 inhibitory neurons display signs of ferroptosis. All cell types have enriched states in autosomal dominant carriers. We leverage differential expression and single-nucleus ATAC-seq to map GWAS signals to effector cell types including the NCK2 signal to neurons in addition to the initially proposed microglia. Overall, our results provide insights into the transcriptional diversity resulting from AD genetic architecture and cellular heterogeneity. The data can be explored on the online browser (http://web.hararilab.org/SNARE/).