Browsing by Author "Redding-Ochoa, Javier"

Now showing 1 - 6 of 6
  • Thumbnail Image
    Item
    Activated endothelial cells induce a distinct type of astrocytic reactivity
    (Springer Nature, 2022-03-29) Taylor, Xavier; Cisternas, Pablo; Jury, Nur; Martinez, Pablo; Huang, Xiaoqing; You, Yanwen; Redding-Ochoa, Javier; Vidal, Ruben; Zhang, Jie; Troncoso, Juan; Lasagna-Reeves, Cristian A.; Anatomy, Cell Biology and Physiology, School of Medicine
    Reactive astrogliosis is a universal response of astrocytes to abnormal events and injuries. Studies have shown that proinflammatory microglia can polarize astrocytes (designated A1 astrocytes) toward a neurotoxic phenotype characterized by increased Complement Component 3 (C3) expression. It is still unclear if inflammatory stimuli from other cell types may also be capable of inducing a subset of C3+ neurotoxic astrocytes. Here, we show that a subtype of C3+ neurotoxic astrocytes is induced by activated endothelial cells that is distinct from astrocytes activated by microglia. Furthermore, we show that endothelial-induced astrocytes have upregulated expression of A1 astrocytic genes and exhibit a distinctive extracellular matrix remodeling profile. Finally, we demonstrate that endothelial-induced astrocytes are Decorin-positive and are associated with vascular amyloid deposits but not parenchymal amyloid plaques in mouse models and AD/CAA patients. These findings demonstrate the existence of potentially extensive and subtle functional diversity of C3+-reactive astrocytes.
  • Thumbnail Image
    Item
    Bassoon contributes to tau-seed propagation and neurotoxicity
    (Springer Nature, 2022) Martinez, Pablo; Patel, Henika; You, Yanwen; Jury, Nur; Perkins, Abigail; Lee-Gosselin, Audrey; Taylor, Xavier; You, Yingjian; Di Prisco, Gonzalo Viana; Huang, Xiaoqing; Dutta, Sayan; Wijeratne, Aruna B.; Redding-Ochoa, Javier; Shahid, Syed Salman; Codocedo, Juan F.; Min, Sehong; Landreth, Gary E.; Mosley, Amber L.; Wu, Yu-Chien; McKinzie, David L.; Rochet, Jean-Christophe; Zhang, Jie; Atwood, Brady K.; Troncoso, Juan; Lasagna-Reeves, Cristian A.; Anatomy, Cell Biology and Physiology, School of Medicine
    Tau aggregation is a defining histopathological feature of Alzheimer’s disease and other tauopathies. However, the cellular mechanisms involved in tau propagation remain unclear. Here, we performed an unbiased quantitative proteomic study to identify proteins that specifically interact with this tau seed. We identified Bassoon (BSN), a presynaptic scaffolding protein, as an interactor of the tau seed isolated from a mouse model of tauopathy, and from Alzheimer’s disease and progressive supranuclear palsy postmortem samples. We show that BSN exacerbates tau seeding and toxicity in both mouse and Drosophila models for tauopathy, and that BSN downregulation decreases tau spreading and overall disease pathology, rescuing synaptic and behavioral impairments and reducing brain atrophy. Our findings improve the understanding of how tau seeds can be stabilized by interactors such as BSN. Inhibiting tau-seed interactions is a potential new therapeutic approach for neurodegenerative tauopathies.
  • Thumbnail Image
    Item
    Creating the Pick's disease International Consortium: Association study of MAPT H2 haplotype with risk of Pick's disease
    (medRxiv, 2023-04-24) Valentino, Rebecca R.; Scotton, William J.; Roemer, Shanu F.; Lashley, Tammaryn; Heckman, Michael G.; Shoai, Maryam; Martinez-Carrasco, Alejandro; Tamvaka, Nicole; Walton, Ronald L.; Baker, Matthew C.; Macpherson, Hannah L.; Real, Raquel; Soto-Beasley, Alexandra I.; Mok, Kin; Revesz, Tamas; Warner, Thomas T.; Jaunmuktane, Zane; Boeve, Bradley F.; Christopher, Elizabeth A.; DeTure, Michael; Duara, Ranjan; Graff-Radford, Neill R.; Josephs, Keith A.; Knopman, David S.; Koga, Shunsuke; Murray, Melissa E.; Lyons, Kelly E.; Pahwa, Rajesh; Parisi, Joseph E.; Petersen, Ronald C.; Whitwell, Jennifer; Grinberg, Lea T.; Miller, Bruce; Schlereth, Athena; Seeley, William W.; Spina, Salvatore; Grossman, Murray; Irwin, David J.; Lee, Edward B.; Suh, EunRan; Trojanowski, John Q.; Van Deerlin, Vivianna M.; Wolk, David A.; Connors, Theresa R.; Dooley, Patrick M.; Frosch, Matthew P.; Oakley, Derek H.; Aldecoa, Iban; Balasa, Mircea; Gelpi, Ellen; Borrego-Écija, Sergi; de Eugenio Huélamo, Rosa Maria; Gascon-Bayarri, Jordi; Sánchez-Valle, Raquel; Sanz-Cartagena, Pilar; Piñol-Ripoll, Gerard; Molina-Porcel, Laura; Bigio, Eileen H.; Flanagan, Margaret E.; Gefen, Tamar; Rogalski, Emily J.; Weintraub, Sandra; Redding-Ochoa, Javier; Chang, Koping; Troncoso, Juan C.; Prokop, Stefan; Newell, Kathy L.; Ghetti, Bernardino; Jones, Matthew; Richardson, Anna; Robinson, Andrew C.; Roncaroli, Federico; Snowden, Julie; Allinson, Kieren; Green, Oliver; Rowe, James B.; Singh, Poonam; Beach, Thomas G.; Serrano, Geidy E.; Flowers, Xena E.; Goldman, James E.; Heaps, Allison C.; Leskinen, Sandra P.; Teich, Andrew F.; Black, Sandra E.; Keith, Julia L.; Masellis, Mario; Bodi, Istvan; King, Andrew; Sarraj, Safa-Al; Troakes, Claire; Halliday, Glenda M.; Hodges, John R.; Kril, Jillian J.; Kwok, John B.; Piguet, Olivier; Gearing, Marla; Arzberger, Thomas; Roeber, Sigrun; Attems, Johannes; Morris, Christopher M.; Thomas, Alan J.; Evers, Bret M.; White, Charles L.; Mechawar, Naguib; Sieben, Anne A.; Cras, Patrick P.; De Vil, Bart B.; De Deyn, Peter Paul P. P.; Duyckaerts, Charles; Le Ber, Isabelle; Seihean, Danielle; Turbant-Leclere, Sabrina; MacKenzie, Ian R.; McLean, Catriona; Cykowski, Matthew D.; Ervin, John F.; Wang, Shih-Hsiu J.; Graff, Caroline; Nennesmo, Inger; Nagra, Rashed M.; Riehl, James; Kovacs, Gabor G.; Giaccone, Giorgio; Nacmias, Benedetta; Neumann, Manuela; Ang, Lee-Cyn; Finger, Elizabeth C.; Blauwendraat, Cornelis; Nalls, Mike A.; Singleton, Andrew B.; Vitale, Dan; Cunha, Cristina; Carvalho, Agostinho; Wszolek, Zbigniew K.; Morris, Huw R.; Rademakers, Rosa; Hardy, John A.; Dickson, Dennis W.; Rohrer, Jonathan D.; Ross, Owen A.; Pathology and Laboratory Medicine, School of Medicine
    Background: Pick's disease (PiD) is a rare and predominantly sporadic form of frontotemporal dementia that is classified as a primary tauopathy. PiD is pathologically defined by argyrophilic inclusion Pick bodies and ballooned neurons in the frontal and temporal brain lobes. PiD is characterised by the presence of Pick bodies which are formed from aggregated, hyperphosphorylated, 3-repeat tau proteins, encoded by the MAPT gene. The MAPT H2 haplotype has consistently been associated with a decreased disease risk of the 4-repeat tauopathies of progressive supranuclear palsy and corticobasal degeneration, however its role in susceptibility to PiD is unclear. The primary aim of this study was to evaluate the association between MAPT H2 and risk of PiD. Methods: We established the Pick's disease International Consortium (PIC) and collected 338 (60.7% male) pathologically confirmed PiD brains from 39 sites worldwide. 1,312 neurologically healthy clinical controls were recruited from Mayo Clinic Jacksonville, FL (N=881) or Rochester, MN (N=431). For the primary analysis, subjects were directly genotyped for MAPT H1-H2 haplotype-defining variant rs8070723. In secondary analysis, we genotyped and constructed the six-variant MAPT H1 subhaplotypes (rs1467967, rs242557, rs3785883, rs2471738, rs8070723, and rs7521). Findings: Our primary analysis found that the MAPT H2 haplotype was associated with increased risk of PiD (OR: 1.35, 95% CI: 1.12-1.64 P=0.002). In secondary analysis involving H1 subhaplotypes, a protective association with PiD was observed for the H1f haplotype (0.0% vs. 1.2%, P=0.049), with a similar trend noted for H1b (OR: 0.76, 95% CI: 0.58-1.00, P=0.051). The 4-repeat tauopathy risk haplotype MAPT H1c was not associated with PiD susceptibility (OR: 0.93, 95% CI: 0.70-1.25, P=0.65). Interpretation: The PIC represents the first opportunity to perform relatively large-scale studies to enhance our understanding of the pathobiology of PiD. This study demonstrates that in contrast to its protective role in 4R tauopathies, the MAPT H2 haplotype is associated with an increased risk of PiD. This finding is critical in directing isoform-related therapeutics for tauopathies.
  • Thumbnail Image
    Item
    Enhanced microglial dynamics and paucity of tau seeding in the amyloid plaque microenvironment contributes to cognitive resilience in Alzheimer’s disease
    (bioRxiv, 2023-07-28) Jury-Garfe, Nur; You, Yanwen; Martínez, Pablo; Redding-Ochoa, Javier; Karahan, Hande; Johnson, Travis S.; Zhan, Jie; Kim, Jungsu; Troncoso, Juan C.; Lasagna-Reeves, Cristian A.; Anatomy, Cell Biology and Physiology, School of Medicine
    Asymptomatic Alzheimer’s disease (AsymAD) describes the status of subjects with preserved cognition but with identifiable Alzheimer’s disease (AD) brain pathology (i.e. Aβ-amyloid deposits, neuritic plaques, and neurofibrillary tangles) at autopsy. In this study, we investigated the postmortem brains of a cohort of AsymAD cases to gain insight into the underlying mechanisms of resilience to AD pathology and cognitive decline. Our results showed that AsymAD cases exhibit an enrichment of core plaques and decreased filamentous plaque accumulation, as well as an increase in microglia surrounding this last type. In AsymAD cases we found less pathological tau aggregation in dystrophic neurites compared to AD and tau seeding activity comparable to healthy control subjects. We used spatial transcriptomics to further characterize the plaque niche and found autophagy, endocytosis, and phagocytosis within the top upregulated pathways in the AsymAD plaque niche, but not in AD. Furthermore, we found ARP2, an actin-based motility protein crucial to initiate the formation of new actin filaments, increased within microglia in the proximity of amyloid plaques in AsymAD. Our findings support that the amyloid-plaque microenvironment in AsymAD cases is characterized by microglia with highly efficient actin-based cell motility mechanisms and decreased tau seeding compared to AD. These two mechanisms can potentially provide protection against the toxic cascade initiated by Aβ that preserves brain health and slows down the progression of AD pathology.
  • Thumbnail Image
    Item
    Transcriptional signatures of hippocampal tau pathology in primary age-related tauopathy and Alzheimer’s disease
    (Elsevier, 2025) Stein-O’Brien, Genevieve L.; Palaganas, Ryan; Meyer, Ernest M.; Redding-Ochoa, Javier; Pletnikova, Olga; Guo, Haidan; Bell, William R.; Troncoso, Juan C.; Huganir, Richard L.; Morris, Meaghan; Pathology and Laboratory Medicine, School of Medicine
    In primary age-related tauopathy (PART) and Alzheimer's disease (AD), tau aggregates share a similar structure and anatomic distribution, which is distinct from tau pathology in other diseases. However, transcriptional similarities between PART and AD and gene expression changes within tau-pathology-bearing neurons are largely unknown. Using GeoMx spatial transcriptomics, mRNA was quantified in hippocampal neurons with and without tau pathology in PART and AD. Synaptic genes were down-regulated in disease overall but up-regulated in tau-pathology-positive neurons. Two transcriptional signatures were associated with intraneuronal tau, both validated in a cortical AD dataset. Genes in the up-regulated signature were enriched in calcium regulation and synaptic function. Notably, transcriptional changes associated with intraneuronal tau in PART and AD were similar, suggesting a possible mechanistic relationship. These findings highlight the power of molecular analysis stratified by pathology and provide insight into common pathways associated with tau pathology in PART and AD.
  • Thumbnail Image
    Item
    Transcriptional Signatures of Hippocampal Tau Pathology in Primary Age-Related Tauopathy and Alzheimer’s Disease
    (medRxiv, 2023-09-12) Stein-O’Brien, Genevieve L.; Palaganas, Ryan; Meyer, Ernest M.; Redding-Ochoa, Javier; Pletnikova, Olga; Guo, Haidan; Bell, William R.; Troncoso, Juan C.; Huganir, Richard L.; Morris, Meaghan; Pathology and Laboratory Medicine, School of Medicine
    Background: Tau pathology is common in age-related neurodegenerative diseases. Tau pathology in primary age-related tauopathy (PART) and in Alzheimer's disease (AD) has a similar biochemical structure and anatomic distribution, which is distinct from tau pathology in other diseases. However, the molecular changes associated with intraneuronal tau pathology in PART and AD, and whether these changes are similar in the two diseases, is largely unexplored. Methods: Using GeoMx spatial transcriptomics, mRNA was quantified in CA1 pyramidal neurons with tau pathology and adjacent neurons without tau pathology in 6 cases of PART and 6 cases of AD, and compared to 4 control cases without pathology. Transcriptional changes were analyzed for differential gene expression and for coordinated patterns of gene expression associated with both disease state and intraneuronal tau pathology. Results: Synaptic gene changes and two novel gene expression signatures associated with intraneuronal tau were identified in PART and AD. Overall, gene expression changes associated with intraneuronal tau pathology were similar in PART and AD. Synaptic gene expression was decreased overall in neurons in AD and PART compared to control cases. However, this decrease was largely driven by neurons lacking tau pathology. Synaptic gene expression was increased in tau-positive neurons compared to tau-negative neurons in disease. Two novel gene expression signatures associated with intraneuronal tau were identified by examining coordinated patterns of gene expression. Genes in the up-regulated expression pattern were enriched in calcium regulation and synaptic function pathways, specifically in synaptic exocytosis. These synaptic gene changes and intraneuronal tau expression signatures were confirmed in a published transcriptional dataset of cortical neurons with tau pathology in AD. Conclusions: PART and AD show similar transcriptional changes associated with intraneuronal tau pathology in CA1 pyramidal neurons, raising the possibility of a mechanistic relationship between the tau pathology in the two diseases. Intraneuronal tau pathology was also associated with increased expression of genes associated with synaptic function and calcium regulation compared to tau-negative disease neurons. The findings highlight the power of molecular analysis stratified by pathology in neurodegenerative disease and provide novel insight into common molecular pathways associated with intraneuronal tau in PART and AD.