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  Glial and vascular contributions to neurodegenerative diseases
  APP/PS1 mice compared to vehicle treated controls. Accordingly, genetic ablation of Bach1 in APP/PS1 mice also attenuated cognitive impairment. Functional genomics analysis demonstrated that the neuroprotective effects of Bach1 inhibition was due to upregulation of Bach1-targeted pathways including Nrf2-dependent antioxidants response element (ARE) and Nrf2-independent non-ARE genes. Conclusion: Our findings suggest that pharmacologic inhibition and genetic deletion of Bach1 attenuates progression of AD-like pathology and that Bach1 inhibition is a promising therapeutic approach.
brain cells, which may enable the discovery and validation of brain disease biomarkers and help identify cell-specific markers of brain EV subpopulations and their physiological roles.
Frontal cortex Angiotensin type 2 receptor- interacting protein levels are associated with less brain amyloid-β burden in postmortem brains of older adults with Alzheimer’s dementia
Caglar Cosarderelioglu1, Alma Plaza-Rodriguez2, Pablo Iglesias3, Simion Kreimer4, C. Conover Talbot Jr.5, D. Brian Foster6, Robert N. Cole4, Jeremy Walston1, Peter Abadir1 1Division of Geriatric Medicine and Gerontology, Johns Hopkins University School of Medicine, Baltimore, USA, 2Krieger School of Arts and Sciences, Johns Hopkins University, Baltimore, USA, 3Department of Electrical and Computer Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, USA, 4The Mass Spectrometry and Proteomics Facility, The Johns Hopkins University School of Medicine , Baltimore, USA, 5Institute for Basic
Biomedical Sciences, Johns Hopkins University School of Medicine, Baltimore, USA, 6Division of Cardiology, Department of Medicine, Johns Hopkins University, Baltimore, USA
A novel isolation method for spontaneously released extracellular vesicles from brain tissue and its implications for stress-driven brain pathology
Patrícia Gomes1,2, A. Catarina Vilaça-Ferreira1,2, Cristian Bodo3, Carlos Nogueras-Ortiz4, Martina Samiotaki5, Minghao Chen6,7, Carina Soares-Cunha1,2, Joana M. Silva1,2, Bárbara Coimbra1,2, George Stamatakis5, Liliana Santos1,2, George Panayotou5, Foteini Tzouanou8, Clarissa L. Waites9, Christos Gatsogiannis6,7, Nuno Sousa1,2, Dimitrios Kapogiannis4, Bruno Costa-Silva3, Ioannis Sotiropoulos1,2,8
1Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus de Gualtar, Braga, 4710-057, Portugal, 2ICVS/3B’s - PT Government Associate Laboratory, Braga/Guimarães, Portugal, Braga/Guimarães, Portugal, 3Systems Oncology Group, Champalimaud Research, Champalimaud Centre for the Unknown, Lisbon, 1400-038, Portugal, 4Laboratory of Clinical Investigation, Intramural Research Program, National Institute on Aging, NIH, Baltimore, USA, 5Institute for Bioinnovation, Biomedical Sciences Research Center “Alexander Fleming”, Vari, Attica, Greece, 6Center for Soft Nanoscience
and Institute of Medical Physics and Biophysics, University of Muenster, Muenster, 48149, Germany, 7Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, 44227, Germany, 8Institute of Biosciences & Applications NCSR "Demokritos", Athens, Greece, 9Department of Pathology and Cell Biology, Taub Institute for
Research on Alzheimer’s Disease and the Aging Brain, Columbia University Medical Center, New York, USA
 Background: Extracellular vesicles (EVs), including small EVs (sEVs), exhibit great potential for the diagnosis and treatment of brain disorders, representing an advantageous tool for precision medicine. Thus, the collection and characterization of physiologically relevant sEVs are of the utmost importance. However, standard brain EV isolation approaches rely on tissue dissociation, which can contaminate EV fractions and alter membrane composition [1,2]. Hence, to obtain a more physiologically relevant small EV-enriched population we developed a purification method.
Materials and Methods: To assess the quality and validate the new purification method from mouse and human brain tissue, cryo-EM, label-free proteomics, advanced flow cytometry, and ExoView analyses were performed. Subsequently, the impact of pharmacological manipulation and the effect of chronic stress on sEV biogenesis/ secretion was evaluated by a comprehensive battery of behavioral tests and molecular analyses.
Results: Our findings reveal that the released method efficiently obtained a sEVs-enriched population spontaneously released by mouse and human brain tissue. Additionally, we were able to monitor the drug- evoked inhibition or enhancement of sEVs secretion while chronic stress induces the secretion of brain exosomes accompanied by memory loss and mood deficits.
Discussion: The proteome of EVs yield of the release method (but not the standard ones which include digestion of the tissue by papain) is particularly enriched in membrane and extracellular region categories, which may be related to the effect of papain on the composition of the plasma membrane [1,2]. Moreover, the effect of stress on EVs suggests a potential role of sEVs in the brain response to stress and related stress- driven brain pathology.
Conclusions: This novel isolation method constitutes a tool for detailed “mapping” of physiologically relevant sEVs released directly from
Angiotensin system, aging, and Alzheimer's disease are tightly linked. Of the brain angiotensin receptors, the subtype 2 receptor (AT2R) is relatively less studied. Canonically, the AT2R functions through nitric oxide release, and its activation has been linked to vasodilatation and neurite outgrowth as well as anti-inflammation. How AT2R signals is not known, however, an AT2R-interacting protein (ATIP) has been recently described. Controversies exist on the link between ATIP and AT2R functions. Here, we describe the development of the first non-antibody- based ultra-sensitive and specific quantitative mass spectrometry assay for ATIP. Using a technique that permits targeted analysis of multiple peptides across multiple samples in a single mass spectrometry run, known as TOMAHAQ, we have identified specific human tryptic peptides that permit quantification of ATIP abundance. We have used this method to quantify ATIP in postmortem frontal cortex samples of older adults (n= 60) with Alzheimer’s dementia (AD). We correlated levels of ATIP to brain RAS receptors, and biomarkers of AD pathogenesis including oxidative stress, inflammation, mitochondrial dysfunction as well as amyloid-β and tau burden. Our results show that ATIP expression (ANLKNPQIMYLEQELESLK sequence of ATIP) is positively correlated with neuronal nitric oxide synthase (nNOS) (p = 0.009, r = 0.337). Furthermore, expression of ATIP is negatively correlated with amyloid-β load in several brain regions including hippocampus (p= 0.014, r= -0.317), entorhinal cortex (p= 0.010, r= -0.331), frontal cortex (p= 0.023, r= -0.294), and overall (p= 0.004, r= -0.365). These results highlight a potential protective role for ATIP in Alzheimer’s disease.
Implication of apoE in the crosstalk of meningeal lymphatic function and innate immunity
Nikoleta Delivanoglou1, Kennedi Todd3, Sofia Pereira Das Neves1, Megan J. Barber1, Guadalupe Sanchez1,2, Yuka Martens1, Silvia S. Kang1, John D. Fryer3, Guojun Bu1, Sandro Da Mesquita1,2
1Department of Neuroscience, Mayo Clinic, Jacksonville, USA, 2Neuroscience Ph.D. Program, Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Jacksonville, USA, 3Department of Neuroscience, Mayo Clinic, Scottsdale, USA
 70 • ISMND 2022
Background: The factors governing the progressive dysregulation of the meningeal lymphatic system with aging and in Alzheimer’s disease are poorly understood. Herein, we explore the role of apolipoprotein E (apoE) as a modulator of meningeal lymphatic vasculature and test the hypothesis that apoE4 leads to poor brain drainage by meningeal lymphatics.

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