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Cai Y, Zhang Y, Leng S, Ma Y, Jiang Q, Wen Q, Ju S, Hu J. The relationship between inflammation, impaired glymphatic system, and neurodegenerative disorders: A vicious cycle. Neurobiol Dis 2024; 192:106426. [PMID: 38331353 DOI: 10.1016/j.nbd.2024.106426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Revised: 01/16/2024] [Accepted: 01/28/2024] [Indexed: 02/10/2024] Open
Abstract
The term "glymphatic" emerged roughly a decade ago, marking a pivotal point in neuroscience research. The glymphatic system, a glial-dependent perivascular network distributed throughout the brain, has since become a focal point of investigation. There is increasing evidence suggesting that impairment of the glymphatic system appears to be a common feature of neurodegenerative disorders, and this impairment exacerbates as disease progression. Nevertheless, the common factors contributing to glymphatic system dysfunction across most neurodegenerative disorders remain unclear. Inflammation, however, is suspected to play a pivotal role. Dysfunction of the glymphatic system can lead to a significant accumulation of protein and waste products, which can trigger inflammation. The interaction between the glymphatic system and inflammation appears to be cyclical and potentially synergistic. Yet, current research is limited, and there is a lack of comprehensive models explaining this association. In this perspective review, we propose a novel model suggesting that inflammation, impaired glymphatic function, and neurodegenerative disorders interconnected in a vicious cycle. By presenting experimental evidence from the existing literature, we aim to demonstrate that: (1) inflammation aggravates glymphatic system dysfunction, (2) the impaired glymphatic system exacerbated neurodegenerative disorders progression, (3) neurodegenerative disorders progression promotes inflammation. Finally, the implication of proposed model is discussed.
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Affiliation(s)
- Yu Cai
- Nurturing Center of Jiangsu Province for State Laboratory of AI Imaging & Interventional Radiology, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing 210009, China
| | - Yangqiqi Zhang
- School of Medicine, Southeast University, Nanjing 210009, China
| | - Shuo Leng
- Center of Interventional Radiology and Vascular Surgery, Department of Radiology, Zhongda Hospital, Medical School, Southeast University, 87 Dingjiaqiao Road, Nanjing 210009, China
| | - Yuanyuan Ma
- Nurturing Center of Jiangsu Province for State Laboratory of AI Imaging & Interventional Radiology, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing 210009, China
| | - Quan Jiang
- Department of Neurology, Henry Ford Health System, 2799 W Grand Blvd, Detroit, MI 48202, USA
| | - Qiuting Wen
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 355 W.16th Street, Indianapolis, IN 46202-5188, USA
| | - Shenghong Ju
- Nurturing Center of Jiangsu Province for State Laboratory of AI Imaging & Interventional Radiology, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing 210009, China.
| | - Jiani Hu
- Department of Radiology, School of Medicine, Wayne State University, Detroit, MI 48201, USA.
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Wu JR, Hernandez Y, Miyasaki KF, Kwon EJ. Engineered nanomaterials that exploit blood-brain barrier dysfunction fordelivery to the brain. Adv Drug Deliv Rev 2023; 197:114820. [PMID: 37054953 DOI: 10.1016/j.addr.2023.114820] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 03/30/2023] [Accepted: 04/04/2023] [Indexed: 04/15/2023]
Abstract
The blood-brain barrier (BBB) is a highly regulated physical and functional boundarythat tightly controls the transport of materials between the blood and the brain. There is an increasing recognition that the BBB is dysfunctional in a wide range of neurological disorders; this dysfunction can be symptomatic of the disease but can also play a role in disease etiology. BBB dysfunction can be exploited for the delivery of therapeutic nanomaterials. Forexample, there can be a transient, physical disruption of the BBB in diseases such as brain injury and stroke, which allows temporary access of nanomaterials into the brain. Physicaldisruption of the BBB through external energy sources is now being clinically pursued toincrease therapeutic delivery into the brain. In other diseases, the BBB takes on new properties that can beleveraged by delivery carriers. For instance, neuroinflammation induces the expression ofreceptors on the BBB that can be targeted by ligand-modified nanomaterials and theendogenous homing of immune cells into the diseased brain can be hijacked for the delivery ofnanomaterials. Lastly, BBB transport pathways can be altered to increase nanomaterial transport. In this review, we will describe changes that can occur in the BBB in disease, and how these changes have been exploited by engineered nanomaterials forincreased transport into the brain.
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Affiliation(s)
- Jason R Wu
- Department of Bioengineering, University of California San Diego, La Jolla, CA
| | - Yazmin Hernandez
- Department of Bioengineering, University of California San Diego, La Jolla, CA
| | - Katelyn F Miyasaki
- Department of Bioengineering, University of California San Diego, La Jolla, CA
| | - Ester J Kwon
- Department of Bioengineering, University of California San Diego, La Jolla, CA; Sanford Consortium for Regenerative Medicine.
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3
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Wong DR, Conrad J, Johnson N, Ayers J, Laeremans A, Lee JC, Lee J, Prusiner SB, Bandyopadhyay S, Butte AJ, Paras NA, Keiser MJ. Trans-channel fluorescence learning improves high-content screening for Alzheimer's disease therapeutics. NAT MACH INTELL 2022; 4:583-595. [PMID: 36276634 PMCID: PMC9585544 DOI: 10.1038/s42256-022-00490-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 04/19/2022] [Indexed: 02/07/2023]
Abstract
In microscopy-based drug screens, fluorescent markers carry critical information on how compounds affect different biological processes. However, practical considerations, such as the labor and preparation formats needed to produce different image channels, hinders the use of certain fluorescent markers. Consequently, completed screens may lack biologically informative but experimentally impractical markers. Here, we present a deep learning method for overcoming these limitations. We accurately generated predicted fluorescent signals from other related markers and validated this new machine learning (ML) method on two biologically distinct datasets. We used the ML method to improve the selection of biologically active compounds for Alzheimer's disease (AD) from a completed high-content high-throughput screen (HCS) that had only contained the original markers. The ML method identified novel compounds that effectively blocked tau aggregation, which had been missed by traditional screening approaches unguided by ML. The method improved triaging efficiency of compound rankings over conventional rankings by raw image channels. We reproduced this ML pipeline on a biologically independent cancer-based dataset, demonstrating its generalizability. The approach is disease-agnostic and applicable across diverse fluorescence microscopy datasets.
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Affiliation(s)
- Daniel R. Wong
- Institute for Neurodegenerative Diseases, University of California, San Francisco, CA, 94158, USA
- Bakar Computational Health Sciences Institute, University of California, San Francisco, CA, 94158, USA
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA, 94158, USA
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, 94158, USA
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, 94158, USA
- Department of Pediatrics, University of California, San Francisco, CA, 94158, USA
- Center for Data-Driven Insights and Innovation, University of California, Office of the President, Oakland, CA, 94607, USA
| | - Jay Conrad
- Institute for Neurodegenerative Diseases, University of California, San Francisco, CA, 94158, USA
| | - Noah Johnson
- Institute for Neurodegenerative Diseases, University of California, San Francisco, CA, 94158, USA
- University of Colorado Alzheimer’s and Cognition Center, Linda Crnic Institute for Down Syndrome, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, USA
- Department of Neurology, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Jacob Ayers
- Institute for Neurodegenerative Diseases, University of California, San Francisco, CA, 94158, USA
| | - Annelies Laeremans
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, 94158, USA
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA, 94158, USA
| | - Joanne C. Lee
- Institute for Neurodegenerative Diseases, University of California, San Francisco, CA, 94158, USA
| | - Jisoo Lee
- Institute for Neurodegenerative Diseases, University of California, San Francisco, CA, 94158, USA
| | - Stanley B. Prusiner
- Institute for Neurodegenerative Diseases, University of California, San Francisco, CA, 94158, USA
| | - Sourav Bandyopadhyay
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, 94158, USA
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA, 94158, USA
| | - Atul J. Butte
- Bakar Computational Health Sciences Institute, University of California, San Francisco, CA, 94158, USA
- Department of Pediatrics, University of California, San Francisco, CA, 94158, USA
- Center for Data-Driven Insights and Innovation, University of California, Office of the President, Oakland, CA, 94607, USA
| | - Nick A. Paras
- Institute for Neurodegenerative Diseases, University of California, San Francisco, CA, 94158, USA
| | - Michael J. Keiser
- Institute for Neurodegenerative Diseases, University of California, San Francisco, CA, 94158, USA
- Bakar Computational Health Sciences Institute, University of California, San Francisco, CA, 94158, USA
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA, 94158, USA
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, 94158, USA
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, 94158, USA
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Smyth LCD, Murray HC, Hill M, van Leeuwen E, Highet B, Magon NJ, Osanlouy M, Mathiesen SN, Mockett B, Singh-Bains MK, Morris VK, Clarkson AN, Curtis MA, Abraham WC, Hughes SM, Faull RLM, Kettle AJ, Dragunow M, Hampton MB. Neutrophil-vascular interactions drive myeloperoxidase accumulation in the brain in Alzheimer's disease. Acta Neuropathol Commun 2022; 10:38. [PMID: 35331340 PMCID: PMC8944147 DOI: 10.1186/s40478-022-01347-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 03/11/2022] [Indexed: 01/13/2023] Open
Abstract
INTRODUCTION Neutrophil accumulation is a well-established feature of Alzheimer's disease (AD) and has been linked to cognitive impairment by modulating disease-relevant neuroinflammatory and vascular pathways. Neutrophils express high levels of the oxidant-generating enzyme myeloperoxidase (MPO), however there has been controversy regarding the cellular source and localisation of MPO in the AD brain. MATERIALS AND METHODS We used immunostaining and immunoassays to quantify the accumulation of neutrophils in human AD tissue microarrays and in the brains of APP/PS1 mice. We also used multiplexed immunolabelling to define the presence of NETs in AD. RESULTS There was an increase in neutrophils in AD brains as well as in the murine APP/PS1 model of AD. Indeed, MPO expression was almost exclusively confined to S100A8-positive neutrophils in both human AD and murine APP/PS1 brains. The vascular localisation of neutrophils in both human AD and mouse models of AD was striking and driven by enhanced neutrophil adhesion to small vessels. We also observed rare infiltrating neutrophils and deposits of MPO around plaques. Citrullinated histone H3, a marker of neutrophil extracellular traps (NETs), was also detected in human AD cases at these sites, indicating the presence of extracellular MPO in the vasculature. Finally, there was a reduction in the endothelial glycocalyx in AD that may be responsible for non-productive neutrophil adhesion to the vasculature. CONCLUSION Our report indicates that vascular changes may drive neutrophil adhesion and NETosis, and that neutrophil-derived MPO may lead to vascular oxidative stress and be a relevant therapeutic target in AD.
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Affiliation(s)
- Leon C. D. Smyth
- Centre for Free Radical Research, University of Otago, Christchurch, New Zealand
- Department of Pathology and Biomedical Science, University of Otago, PO Box 4345, Christchurch, 8140 New Zealand
- Department of Pathology and Immunology, Center for Brain Immunology and Glia, Washington University in St. Louis, Campus, Box 8118, St. Louis, MO USA
| | - Helen C. Murray
- Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Department of Anatomy With Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Madison Hill
- Centre for Free Radical Research, University of Otago, Christchurch, New Zealand
- Department of Pathology and Biomedical Science, University of Otago, PO Box 4345, Christchurch, 8140 New Zealand
| | - Eve van Leeuwen
- Centre for Free Radical Research, University of Otago, Christchurch, New Zealand
- Department of Pathology and Biomedical Science, University of Otago, PO Box 4345, Christchurch, 8140 New Zealand
| | - Blake Highet
- Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Department of Anatomy With Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Nicholas J. Magon
- Centre for Free Radical Research, University of Otago, Christchurch, New Zealand
- Department of Pathology and Biomedical Science, University of Otago, PO Box 4345, Christchurch, 8140 New Zealand
| | - Mahyar Osanlouy
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Sophie N. Mathiesen
- Department of Psychology, University of Otago, Dunedin, New Zealand
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Bruce Mockett
- Department of Psychology, University of Otago, Dunedin, New Zealand
| | - Malvindar K. Singh-Bains
- Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Department of Anatomy With Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Vanessa K. Morris
- School of Biological Science, University of Canterbury, Canterbury, New Zealand
| | | | - Maurice A. Curtis
- Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Department of Anatomy With Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | | | | | - Richard L. M. Faull
- Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Department of Anatomy With Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Anthony J. Kettle
- Centre for Free Radical Research, University of Otago, Christchurch, New Zealand
- Department of Pathology and Biomedical Science, University of Otago, PO Box 4345, Christchurch, 8140 New Zealand
| | - Mike Dragunow
- Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Department of Pharmacology and Clinical Pharmacology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Mark B. Hampton
- Centre for Free Radical Research, University of Otago, Christchurch, New Zealand
- Department of Pathology and Biomedical Science, University of Otago, PO Box 4345, Christchurch, 8140 New Zealand
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5
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Characterisation of PDGF-BB:PDGFRβ signalling pathways in human brain pericytes: evidence of disruption in Alzheimer's disease. Commun Biol 2022; 5:235. [PMID: 35301433 PMCID: PMC8931009 DOI: 10.1038/s42003-022-03180-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 02/17/2022] [Indexed: 01/03/2023] Open
Abstract
Platelet-derived growth factor-BB (PDGF-BB):PDGF receptor-β (PDGFRβ) signalling in brain pericytes is critical to the development, maintenance and function of a healthy blood-brain barrier (BBB). Furthermore, BBB impairment and pericyte loss in Alzheimer’s disease (AD) is well documented. We found that PDGF-BB:PDGFRβ signalling components were altered in human AD brains, with a marked reduction in vascular PDGFB. We hypothesised that reduced PDGF-BB:PDGFRβ signalling in pericytes may impact on the BBB. We therefore tested the effects of PDGF-BB on primary human brain pericytes in vitro to define pathways related to BBB function. Using pharmacological inhibitors, we dissected distinct aspects of the PDGF-BB response that are controlled by extracellular signal-regulated kinase (ERK) and Akt pathways. PDGF-BB promotes the proliferation of pericytes and protection from apoptosis through ERK signalling. In contrast, PDGF-BB:PDGFRβ signalling through Akt augments pericyte-derived inflammatory secretions. It may therefore be possible to supplement PDGF-BB signalling to stabilise the cerebrovasculature in AD. Smyth et al. use tissue microarrays from Alzheimer’s disease (AD) patient brains to show that PDGF-BB:PDGFRβ signalling components are reduced in AD. They then use primary human brain pericytes to elucidate a pathway by which PDGF-BB:PDGFRβ signalling in brain pericytes is disrupted in AD, thus impairing the blood brain barrier.
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6
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Preparation, construction and high-throughput automated analysis of human brain tissue microarrays for neurodegenerative disease drug development. Nat Protoc 2021; 16:2308-2343. [PMID: 33742177 DOI: 10.1038/s41596-021-00503-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 01/19/2021] [Indexed: 02/03/2023]
Abstract
A major challenge in the treatment of neurodegenerative disorders is the translation of effective therapies from the lab to the clinic. One approach to improve this process is the use of human brain tissue microarray (HBTMA) technology to aid in the discovery and validation of drug targets for brain disorders. In this protocol we describe a platform for the production of high-quality HBTMAs that can be used for drug target discovery and validation. We provide examples of the use of this platform and describe detailed protocols for HBTMA design, construction and use for both protein and mRNA detection. This platform requires less tissue and reagents than single-slide approaches, greatly increasing throughput and capacity, enabling samples to be compared in a more consistent way. It takes 4 d to construct a 60 core HBTMA. Immunohistochemistry and in situ hybridization take a further 2 d. Imaging of each HBTMA slide takes 15 min, with subsequent high-content analysis taking 30 min-2 h.
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7
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Highet B, Vikas Anekal P, Ryan B, Murray H, Coppieters N, Victor Dieriks B, Singh-Bains MK, Mehrabi NF, Faull RLM, Dragunow M, Curtis MA. fISHing with immunohistochemistry for housekeeping gene changes in Alzheimer's disease using an automated quantitative analysis workflow. J Neurochem 2021; 157:1270-1283. [PMID: 33368239 DOI: 10.1111/jnc.15283] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 11/12/2020] [Accepted: 12/21/2020] [Indexed: 12/28/2022]
Abstract
In situ hybridization (ISH) is a powerful tool that can be used to localize mRNA expression in tissue samples. Combining ISH with immunohistochemistry (IHC) to determine cell type provides cellular context of mRNA expression, which cannot be achieved with gene microarray or polymerase chain reaction. To study mRNA and protein expression on the same section we investigated the use of RNAscope® ISH in combination with fluorescent IHC on paraffin-embedded human brain tissue. We first developed a high-throughput, automated image analysis workflow for quantifying RNA puncta across the total cell population and within neurons identified by NeuN+ immunoreactivity. We then applied this automated analysis to tissue microarray (TMA) sections of middle temporal gyrus tissue (MTG) from neurologically normal and Alzheimer's Disease (AD) cases to determine the suitability of three commonly used housekeeping genes: ubiquitin C (UBC), peptidyl-prolyl cis-trans isomerase B (PPIB) and DNA-directed RNA polymerase II subunit RPB1 (POLR2A). Overall, we saw a significant decrease in total and neuronal UBC expression in AD cases compared to normal cases. Total expression results were validated with RT-qPCR using fresh frozen tissue from 5 normal and 5 AD cases. We conclude that this technique combined with our novel automated analysis pipeline provides a suitable platform to study changes in gene expression in diseased human brain tissue with cellular and anatomical context. Furthermore, our results suggest that UBC is not a suitable housekeeping gene in the study of post-mortem AD brain tissue.
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Affiliation(s)
- Blake Highet
- Department of Anatomy and Medical Imaging, Faculty of Medical and Health Science, University of Auckland, Auckland, New Zealand.,Centre for Brain Research, Faculty of Medical and Health Science, University of Auckland, Auckland, New Zealand
| | - Praju Vikas Anekal
- Biomedical Imaging Research Unit, Faculty of Medical and Health Science, University of Auckland, Auckland, New Zealand
| | - Brigid Ryan
- Department of Anatomy and Medical Imaging, Faculty of Medical and Health Science, University of Auckland, Auckland, New Zealand.,Centre for Brain Research, Faculty of Medical and Health Science, University of Auckland, Auckland, New Zealand
| | - Helen Murray
- Department of Anatomy and Medical Imaging, Faculty of Medical and Health Science, University of Auckland, Auckland, New Zealand.,Centre for Brain Research, Faculty of Medical and Health Science, University of Auckland, Auckland, New Zealand
| | - Natacha Coppieters
- Laboratory of Nervous System Disorders and Therapy, GIGA-Neuroscience, University of Liège, Liège, Belgium
| | - Birger Victor Dieriks
- Department of Anatomy and Medical Imaging, Faculty of Medical and Health Science, University of Auckland, Auckland, New Zealand.,Centre for Brain Research, Faculty of Medical and Health Science, University of Auckland, Auckland, New Zealand
| | - Malvindar K Singh-Bains
- Department of Anatomy and Medical Imaging, Faculty of Medical and Health Science, University of Auckland, Auckland, New Zealand.,Centre for Brain Research, Faculty of Medical and Health Science, University of Auckland, Auckland, New Zealand
| | - Nasim F Mehrabi
- Centre for Brain Research, Faculty of Medical and Health Science, University of Auckland, Auckland, New Zealand.,Department of Pharmacology, Faculty of Medical and Health Science, University of Auckland, Auckland, New Zealand
| | - Richard L M Faull
- Department of Anatomy and Medical Imaging, Faculty of Medical and Health Science, University of Auckland, Auckland, New Zealand.,Centre for Brain Research, Faculty of Medical and Health Science, University of Auckland, Auckland, New Zealand
| | - Michael Dragunow
- Centre for Brain Research, Faculty of Medical and Health Science, University of Auckland, Auckland, New Zealand.,Department of Pharmacology, Faculty of Medical and Health Science, University of Auckland, Auckland, New Zealand
| | - Maurice A Curtis
- Department of Anatomy and Medical Imaging, Faculty of Medical and Health Science, University of Auckland, Auckland, New Zealand.,Centre for Brain Research, Faculty of Medical and Health Science, University of Auckland, Auckland, New Zealand
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8
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Dragunow M. Human Brain Neuropharmacology: A Platform for Translational Neuroscience. Trends Pharmacol Sci 2020; 41:777-792. [PMID: 32994050 DOI: 10.1016/j.tips.2020.09.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 07/10/2020] [Accepted: 09/10/2020] [Indexed: 12/20/2022]
Abstract
Central nervous system (CNS) drug development has been plagued by a failure to translate effective therapies from the lab to the clinic. There are many potential reasons for this, including poor understanding of brain pharmacokinetic (PK) and pharmacodynamic (PD) factors, preclinical study flaws, clinical trial design issues, the complexity and variability of human brain diseases, as well as species differences. To address some of these problems, we have developed a platform for CNS drug discovery comprising: drug screening of primary adult human brain cells; human brain tissue microarray analysis of drug targets; and high-content phenotypic screening methods. In this opinion, I summarise the theoretical basis and the practical development and use of this platform in CNS drug discovery.
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Affiliation(s)
- Mike Dragunow
- Department of Pharmacology and Hugh Green Biobank, Centre for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand.
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9
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Narayan P, Reid S, Scotter EL, McGregor AL, Mehrabi NF, Singh-Bains MK, Glass M, Faull RLM, Snell RG, Dragunow M. Inconsistencies in histone acetylation patterns among different HD model systems and HD post-mortem brains. Neurobiol Dis 2020; 146:105092. [PMID: 32979507 DOI: 10.1016/j.nbd.2020.105092] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 08/28/2020] [Accepted: 09/21/2020] [Indexed: 01/10/2023] Open
Abstract
Huntington's disease (HD) is a neurodegenerative disorder caused by a CAG trinucleotide repeat expansion in exon 1 of the huntingtin gene. Emerging evidence shows that additional epigenetic factors can modify disease phenotypes. Harnessing the ability of the epigenome to modify the disease for therapeutic purposes is therefore of interest. Epigenome modifiers, such as histone deacetylase inhibitors (HDACi), have improved pathology in a range of HD models. Yet in clinical trials, HDACi have failed to alleviate HD symptoms in patients. This study investigated potential reasons for the lack of translation of the therapeutic benefits of HDACi from lab to clinic. We analysed histone acetylation patterns of immuno-positive nuclei from brain sections and tissue microarrays from post-mortem human control and HD cases alongside several well-established HD models (OVT73 transgenic HD sheep, YAC128 mice, and an in vitro cell model expressing 97Q mutant huntingtin). Significant increases in histone H4 acetylation were observed in post-mortem HD cases, OVT73 transgenic HD sheep and in vitro models; these changes were absent in YAC128 mice. In addition, nuclear labelling for acetyl-histone H4 levels were inversely proportional to mutant huntingtin aggregate load in HD human cortex. Our data raise concerns regarding the utility of HDACi for the treatment of HD when regions of pathology exhibit already elevated histone acetylation patterns and emphasize the importance of searching for alternative epigenetic targets in future therapeutic strategies aiming to rescue HD phenotypes.
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Affiliation(s)
- Pritika Narayan
- Centre for Brain Research, University of Auckland, Auckland 1023, New Zealand; School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand.
| | - Suzanne Reid
- Centre for Brain Research, University of Auckland, Auckland 1023, New Zealand; School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand.
| | - Emma L Scotter
- Centre for Brain Research, University of Auckland, Auckland 1023, New Zealand.
| | - Ailsa L McGregor
- School of Pharmacy, University of Otago, Dunedin 9016, New Zealand.
| | - Nasim F Mehrabi
- Centre for Brain Research, University of Auckland, Auckland 1023, New Zealand.
| | | | - Michelle Glass
- Centre for Brain Research, University of Auckland, Auckland 1023, New Zealand; Department of Pharmacology and Toxicology, University of Otago, Dunedin 9016, New Zealand.
| | - Richard L M Faull
- Centre for Brain Research, University of Auckland, Auckland 1023, New Zealand.
| | - Russell G Snell
- Centre for Brain Research, University of Auckland, Auckland 1023, New Zealand; School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand.
| | - Mike Dragunow
- Centre for Brain Research, University of Auckland, Auckland 1023, New Zealand.
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10
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Lochhead JJ, Yang J, Ronaldson PT, Davis TP. Structure, Function, and Regulation of the Blood-Brain Barrier Tight Junction in Central Nervous System Disorders. Front Physiol 2020; 11:914. [PMID: 32848858 PMCID: PMC7424030 DOI: 10.3389/fphys.2020.00914] [Citation(s) in RCA: 179] [Impact Index Per Article: 44.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Accepted: 07/08/2020] [Indexed: 12/16/2022] Open
Abstract
The blood-brain barrier (BBB) allows the brain to selectively import nutrients and energy critical to neuronal function while simultaneously excluding neurotoxic substances from the peripheral circulation. In contrast to the highly permeable vasculature present in most organs that reside outside of the central nervous system (CNS), the BBB exhibits a high transendothelial electrical resistance (TEER) along with a low rate of transcytosis and greatly restricted paracellular permeability. The property of low paracellular permeability is controlled by tight junction (TJ) protein complexes that seal the paracellular route between apposing brain microvascular endothelial cells. Although tight junction protein complexes are principal contributors to physical barrier properties, they are not static in nature. Rather, tight junction protein complexes are highly dynamic structures, where expression and/or localization of individual constituent proteins can be modified in response to pathophysiological stressors. These stressors induce modifications to tight junction protein complexes that involve de novo synthesis of new protein or discrete trafficking mechanisms. Such responsiveness of BBB tight junctions to diseases indicates that these protein complexes are critical for maintenance of CNS homeostasis. In fulfillment of this vital role, BBB tight junctions are also a major obstacle to therapeutic drug delivery to the brain. There is an opportunity to overcome this substantial obstacle and optimize neuropharmacology via acquisition of a detailed understanding of BBB tight junction structure, function, and regulation. In this review, we discuss physiological characteristics of tight junction protein complexes and how these properties regulate delivery of therapeutics to the CNS for treatment of neurological diseases. Specifically, we will discuss modulation of tight junction structure, function, and regulation both in the context of disease states and in the setting of pharmacotherapy. In particular, we will highlight how these properties can be potentially manipulated at the molecular level to increase CNS drug levels via paracellular transport to the brain.
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11
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Levin RA, Carnegie MH, Celermajer DS. Pulse Pressure: An Emerging Therapeutic Target for Dementia. Front Neurosci 2020; 14:669. [PMID: 32670015 PMCID: PMC7327093 DOI: 10.3389/fnins.2020.00669] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 06/02/2020] [Indexed: 12/11/2022] Open
Abstract
Elevated pulse pressure can cause blood-brain barrier dysfunction and subsequent adverse neurological changes that may drive or contribute to the development of dementia with age. In short, elevated pulse pressure dysregulates cerebral endothelial cells and increases cellular production of oxidative and inflammatory molecules. The resulting cerebral microvascular damage, along with excessive pulsatile mechanical force, can induce breakdown of the blood-brain barrier, which in turn triggers brain cell impairment and death. We speculate that elevated pulse pressure may also reduce the efficacy of other therapeutic strategies for dementia. For instance, BACE1 inhibitors and anti-amyloid-β biologics reduce amyloid-β deposits in the brain that are thought to be a cause of Alzheimer’s disease, the most prevalent form of dementia. However, upregulation of oxidative and inflammatory molecules and increased amyloid-β secretion by cerebral endothelial cells exposed to elevated pulse pressure may hinder cognitive improvements with these drugs. Additionally, stem or progenitor cell therapy has the potential to repair blood-brain barrier damage, but chronic oxidative and inflammatory stress due to elevated pulse pressure can inhibit stem and progenitor cell regeneration. Finally, we discuss current efforts to repurpose blood pressure medications to prevent or treat dementia. We propose that new drugs or devices should be developed to safely reduce elevated pulse pressure specifically to the brain. Such novel technologies may alleviate an entire downstream pathway of cellular dysfunction, oxidation, inflammation, and amyloidogenesis, thereby preventing pulse-pressure-induced cognitive decline. Furthermore, these technologies may also enhance efficacy of other dementia therapeutics when used in combination.
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Affiliation(s)
- Rachel A Levin
- The Brain Protection Company, Sydney, NSW, Australia.,M.H. Carnegie & Co., Sydney, NSW, Australia
| | - Mark H Carnegie
- The Brain Protection Company, Sydney, NSW, Australia.,M.H. Carnegie & Co., Sydney, NSW, Australia
| | - David S Celermajer
- The Brain Protection Company, Sydney, NSW, Australia.,The Heart Research Institute, Sydney, NSW, Australia
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12
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Sun Y, Li Q, Liu W, Zhang B. Relationship between fibrinogen level and its regulatory gene with Alzheimer's disease and vascular dementia. J Int Med Res 2020; 48:300060520902578. [PMID: 32093517 PMCID: PMC7111027 DOI: 10.1177/0300060520902578] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Objective Methods Results Conclusions
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Affiliation(s)
- Yanan Sun
- Department of Neurology, Tianjin Medical University General Hospital, Tianjin, China
| | - Qi Li
- Department of Neurology, Tianjin Medical University General Hospital, Tianjin, China
| | - Wei Liu
- Department of Neurology, Tianjin Medical University General Hospital, Tianjin, China
| | - Benshu Zhang
- Department of Neurology, Tianjin Medical University General Hospital, Tianjin, China
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13
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Altered microglia and neurovasculature in the Alzheimer's disease cerebellum. Neurobiol Dis 2019; 132:104589. [PMID: 31454549 DOI: 10.1016/j.nbd.2019.104589] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 07/30/2019] [Accepted: 08/23/2019] [Indexed: 12/12/2022] Open
Abstract
Traditionally regarded to coordinate movement, the cerebellum also exerts non-motor functions including the regulation of cognitive and behavioral processing, suggesting a potential role in neurodegenerative conditions affecting cognition, such as Alzheimer's disease (AD). This study aims to investigate neuropathology and AD-related molecular changes within the neocerebellum using post-mortem human brain tissue microarrays (TMAs). Immunohistochemistry was conducted on neocerebellar paraffin-embedded TMAs from 24 AD and 24 matched control cases, and free-floating neocerebellar sections from 6 AD and 6 controls. Immunoreactivity was compared between control and AD groups for neuropathological hallmarks (amyloid-β, tau, ubiquitin), Purkinje cells (calbindin), microglia (IBA1, HLA-DR), astrocytes (GFAP) basement-membrane associated molecules (fibronectin, collagen IV), endothelial cells (CD31/PECAM-1) and mural cells (PDGFRβ, αSMA). Amyloid-β expression (total immunolabel intensity) and load (area of immunolabel) was increased by >4-fold within the AD cerebellum. Purkinje cell counts, ubiquitin and tau immunoreactivity were unchanged in AD. IBA1 expression and load was increased by 91% and 69%, respectively, in AD, with no change in IBA1-positive cell number. IBA1-positive cell process length and branching was reduced by 22% and 41%, respectively, in AD. HLA-DR and GFAP immunoreactivity was unchanged in AD. HLA-DR-positive cell process length and branching was reduced by 33% and 49%, respectively, in AD. Fibronectin expression was increased by 27% in AD. Collagen IV, PDGFRβ and αSMA immunoreactivity was unchanged in AD. The number of CD31-positive vessels was increased by 98% in AD, suggesting the increase in CD31 expression and load in AD is due to greater vessel number. The PDGFRβ/CD31 load ratio was reduced by 59% in AD. These findings provide evidence of molecular changes affecting microglia and the neurovasculature within the AD neocerebellum. These changes, occurring without overt neuropathology, support the hypothesis of microglial and neurovascular dysfunction as drivers of AD, which has implications on the neocerebellar contribution to AD symptomatology and pathophysiology.
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14
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Soria J, Mirshahi S, Mirshahi SQ, Varin R, Pritchard LL, Soria C, Mirshahi M. Fibrinogen αC domain: Its importance in physiopathology. Res Pract Thromb Haemost 2019; 3:173-183. [PMID: 31011701 PMCID: PMC6462745 DOI: 10.1002/rth2.12183] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 11/22/2018] [Indexed: 12/17/2022] Open
Abstract
ABSTRACT Fibrinogen, involved in coagulation, is a soluble protein composed of two sets of disulfide-bridged Aα, Bβ, and γ-chains. In this review, we present the clinical implications of the αC domain of the molecule in Alzheimer's disease, hereditary renal amyloidosis and a number of thrombotic and hemorrhagic disorders. In Alzheimer's disease, amyloid beta peptide (Aβ) is increased and binds to the αC domain of normal fibrinogen, triggering increased fibrin(ogen) deposition in patients' brain parenchyma. In hereditary renal amyloidosis, fibrinogen is abnormal, with mutations located in the fibrinogen αC domain. The mutant αC domain derived from fibrinogen degradation folds incorrectly so that, in time, aggregates form, leading to amyloid deposits in the kidneys. In these patients, no thrombotic tendency has been observed. Abnormal fibrinogens with either a point mutation in the αC domain or a frameshift mutation resulting in absence of a part of the αC domain are often associated with either thrombotic events or bleeding. Mutation of an amino acid into cysteine (as in fibrinogens Dusart and Caracas V) or a frameshift mutation yielding an unpaired cysteine in the αC domain is often responsible for thrombotic events. Covalent binding of albumin to the unpaired cysteine via a disulphide bridge leads to decreased accessibility to the fibrinolytic enzymes, hence formation of poorly degradable fibrin clots, which explains the high incidence of thrombosis. In contrast, anomalies due to a frameshift mutation in the αC connector of the molecule, provoking deletion of a great part of the αC domain, are associated with bleeding.
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Affiliation(s)
- Jeannette Soria
- Laboratoire de recherche en Onco‐HématologieHôtel Dieu de ParisParisFrance
- INSERM U 965‐ CARTHôpital LariboisièreParisFrance
| | - Shahsoltan Mirshahi
- INSERM U 965‐ CARTHôpital LariboisièreParisFrance
- Diagnostica StagoGennevilliersFrance
| | | | - Remi Varin
- Faculté de Médecine et de PharmacieRouenFrance
| | - Linda L. Pritchard
- Laboratoire de recherche en Onco‐HématologieHôtel Dieu de ParisParisFrance
| | - Claudine Soria
- Laboratoire de recherche en Onco‐HématologieHôtel Dieu de ParisParisFrance
| | - Massoud Mirshahi
- Laboratoire de recherche en Onco‐HématologieHôtel Dieu de ParisParisFrance
- INSERM U 965‐ CARTHôpital LariboisièreParisFrance
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15
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Dominy SS, Lynch C, Ermini F, Benedyk M, Marczyk A, Konradi A, Nguyen M, Haditsch U, Raha D, Griffin C, Holsinger LJ, Arastu-Kapur S, Kaba S, Lee A, Ryder MI, Potempa B, Mydel P, Hellvard A, Adamowicz K, Hasturk H, Walker GD, Reynolds EC, Faull RLM, Curtis MA, Dragunow M, Potempa J. Porphyromonas gingivalis in Alzheimer's disease brains: Evidence for disease causation and treatment with small-molecule inhibitors. SCIENCE ADVANCES 2019; 5:eaau3333. [PMID: 30746447 PMCID: PMC6357742 DOI: 10.1126/sciadv.aau3333] [Citation(s) in RCA: 1012] [Impact Index Per Article: 202.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 12/11/2018] [Indexed: 05/19/2023]
Abstract
Porphyromonas gingivalis, the keystone pathogen in chronic periodontitis, was identified in the brain of Alzheimer's disease patients. Toxic proteases from the bacterium called gingipains were also identified in the brain of Alzheimer's patients, and levels correlated with tau and ubiquitin pathology. Oral P. gingivalis infection in mice resulted in brain colonization and increased production of Aβ1-42, a component of amyloid plaques. Further, gingipains were neurotoxic in vivo and in vitro, exerting detrimental effects on tau, a protein needed for normal neuronal function. To block this neurotoxicity, we designed and synthesized small-molecule inhibitors targeting gingipains. Gingipain inhibition reduced the bacterial load of an established P. gingivalis brain infection, blocked Aβ1-42 production, reduced neuroinflammation, and rescued neurons in the hippocampus. These data suggest that gingipain inhibitors could be valuable for treating P. gingivalis brain colonization and neurodegeneration in Alzheimer's disease.
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Affiliation(s)
- Stephen S. Dominy
- Cortexyme, Inc., 269 East Grand Ave., South San Francisco, CA, USA
- Corresponding author.
| | - Casey Lynch
- Cortexyme, Inc., 269 East Grand Ave., South San Francisco, CA, USA
| | - Florian Ermini
- Cortexyme, Inc., 269 East Grand Ave., South San Francisco, CA, USA
| | - Malgorzata Benedyk
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
- Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland
| | - Agata Marczyk
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Andrei Konradi
- Cortexyme, Inc., 269 East Grand Ave., South San Francisco, CA, USA
| | - Mai Nguyen
- Cortexyme, Inc., 269 East Grand Ave., South San Francisco, CA, USA
| | - Ursula Haditsch
- Cortexyme, Inc., 269 East Grand Ave., South San Francisco, CA, USA
| | - Debasish Raha
- Cortexyme, Inc., 269 East Grand Ave., South San Francisco, CA, USA
| | | | | | | | - Samer Kaba
- Cortexyme, Inc., 269 East Grand Ave., South San Francisco, CA, USA
| | - Alexander Lee
- Cortexyme, Inc., 269 East Grand Ave., South San Francisco, CA, USA
| | - Mark I. Ryder
- Division of Periodontology, Department of Orofacial Sciences, University of California, San Francisco, San Francisco, CA, USA
| | - Barbara Potempa
- Department of Oral Immunology and Infectious Diseases, University of Louisville School of Dentistry, Louisville, KY, USA
| | - Piotr Mydel
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
- Broegelman Research Laboratory, Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Annelie Hellvard
- Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland
- Broegelman Research Laboratory, Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Karina Adamowicz
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Hatice Hasturk
- The Forsyth Institute, Cambridge, MA, USA
- Harvard University School of Dental Medicine, Boston, MA, USA
| | - Glenn D. Walker
- Cooperative Research Centre for Oral Health Science, Melbourne Dental School and the Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Melbourne, Victoria, Australia
| | - Eric C. Reynolds
- Cooperative Research Centre for Oral Health Science, Melbourne Dental School and the Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Melbourne, Victoria, Australia
| | - Richard L. M. Faull
- Department of Anatomy with Radiology, Centre for Brain Research and NeuroValida, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Maurice A. Curtis
- Centre for Brain Research and NeuroValida, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Mike Dragunow
- Centre for Brain Research and NeuroValida, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Department of Pharmacology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Jan Potempa
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
- Department of Oral Immunology and Infectious Diseases, University of Louisville School of Dentistry, Louisville, KY, USA
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16
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Lee J, Samson AAS, Song JM. Inkjet printing-based β-secretase fluorescence resonance energy transfer (FRET) assay for screening of potential β-secretase inhibitors of Alzheimer's disease. Anal Chim Acta 2018; 1022:89-95. [DOI: 10.1016/j.aca.2018.03.033] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 02/27/2018] [Accepted: 03/20/2018] [Indexed: 10/17/2022]
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17
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Smyth LCD, Rustenhoven J, Park TIH, Schweder P, Jansson D, Heppner PA, O'Carroll SJ, Mee EW, Faull RLM, Curtis M, Dragunow M. Unique and shared inflammatory profiles of human brain endothelia and pericytes. J Neuroinflammation 2018; 15:138. [PMID: 29751771 PMCID: PMC5948925 DOI: 10.1186/s12974-018-1167-8] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 04/18/2018] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Pericytes and endothelial cells are critical cellular components of the blood-brain barrier (BBB) and play an important role in neuroinflammation. To date, the majority of inflammation-related studies in endothelia and pericytes have been carried out using immortalised cell lines or non-human-derived cells. Whether these are representative of primary human cells is unclear and systematic comparisons of the inflammatory responses of primary human brain-derived pericytes and endothelia has yet to be performed. METHODS To study the effects of neuroinflammation at the BBB, primary brain endothelial cells and pericytes were isolated from human biopsy tissue. Culture purity was examined using qPCR and immunocytochemistry. Electrical cell-substrate impedance sensing (ECIS) was used to determine the barrier properties of endothelial and pericyte cultures. Using immunocytochemistry, cytometric bead array, and ECIS, we compared the responses of endothelia and pericytes to a panel of inflammatory stimuli (IL-1β, TNFα, LPS, IFN-γ, TGF-β1, IL-6, and IL-4). Secretome analysis was performed to identify unique secretions of endothelia and pericytes in response to IL-1β. RESULTS Endothelial cells were pure, moderately proliferative, retained the expression of BBB-related junctional proteins and transporters, and generated robust TEER. Both endothelia and pericytes have the same pattern of transcription factor activation in response to inflammatory stimuli but respond differently at the secretion level. Secretome analysis confirmed that endothelia and pericytes have overlapping but distinct secretome profiles in response to IL-1β. We identified several cell-type specific responses, including G-CSF and GM-CSF (endothelial-specific), and IGFBP2 and IGFBP3 (pericyte-specific). Finally, we demonstrated that direct addition of IL-1β, TNFα, LPS, and IL-4 contributed to the loss of endothelial barrier integrity in vitro. CONCLUSIONS Here, we identify important cell-type differences in the inflammatory response of brain pericytes and endothelia and provide, for the first time, a comprehensive profile of the secretions of primary human brain endothelia and pericytes which has implications for understanding how inflammation affects the cerebrovasculature.
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Affiliation(s)
- Leon C D Smyth
- Department of Pharmacology and Clinical Pharmacology, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.,Centre for Brain Research, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
| | - Justin Rustenhoven
- Department of Pharmacology and Clinical Pharmacology, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.,Centre for Brain Research, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
| | - Thomas I-H Park
- Department of Pharmacology and Clinical Pharmacology, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.,Centre for Brain Research, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.,Department of Anatomy and Medical Imaging, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
| | - Patrick Schweder
- Centre for Brain Research, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.,Auckland City Hospital, Auckland, 1023, New Zealand
| | - Deidre Jansson
- Department of Pharmacology and Clinical Pharmacology, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.,Centre for Brain Research, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
| | - Peter A Heppner
- Centre for Brain Research, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.,Auckland City Hospital, Auckland, 1023, New Zealand
| | - Simon J O'Carroll
- Centre for Brain Research, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.,Department of Anatomy and Medical Imaging, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
| | - Edward W Mee
- Centre for Brain Research, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.,Auckland City Hospital, Auckland, 1023, New Zealand
| | - Richard L M Faull
- Centre for Brain Research, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.,Department of Anatomy and Medical Imaging, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
| | - Maurice Curtis
- Centre for Brain Research, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.,Department of Anatomy and Medical Imaging, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
| | - Mike Dragunow
- Department of Pharmacology and Clinical Pharmacology, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand. .,Centre for Brain Research, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.
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18
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Poon CC, Ebacher V, Liu K, Yong VW, Kelly JJP. Automated Slide Scanning and Segmentation in Fluorescently-labeled Tissues Using a Widefield High-content Analysis System. J Vis Exp 2018. [PMID: 29781988 PMCID: PMC6101103 DOI: 10.3791/57440] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Automated slide scanning and segmentation of fluorescently-labeled tissues is the most efficient way to analyze whole slides or large tissue sections. Unfortunately, many researchers spend large amounts of time and resources developing and optimizing workflows that are only relevant to their own experiments. In this article, we describe a protocol that can be used by those with access to a widefield high-content analysis system (WHCAS) to image any slide-mounted tissue, with options for customization within pre-built modules found in the associated software. Not originally intended for slide scanning, the steps detailed in this article make it possible to acquire slide scanning images in the WHCAS which can be imported into the associated software. In this example, the automated segmentation of brain tumor slides is demonstrated, but the automated segmentation of any fluorescently-labeled nuclear or cytoplasmic marker is possible. Furthermore, there are a variety of other quantitative software modules including assays for protein localization/translocation, cellular proliferation/viability/apoptosis, and angiogenesis that can be run. This technique will save researchers time and effort and create an automated protocol for slide analysis.
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Affiliation(s)
- Candice C Poon
- Department of Clinical Neurosciences, Arnie Charbonneau Cancer Institute, University of Calgary;
| | - Vincent Ebacher
- Department of Cell Biology and Anatomy, Hotchkiss Brain Institute, University of Calgary
| | - Katherine Liu
- Department of Clinical Neurosciences, Arnie Charbonneau Cancer Institute, University of Calgary
| | - Voon Wee Yong
- Department of Clinical Neurosciences, Arnie Charbonneau Cancer Institute, University of Calgary; Department of Oncology, Hotchkiss Brain Institute, University of Calgary
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19
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Ahn HJ, Chen ZL, Zamolodchikov D, Norris EH, Strickland S. Interactions of β-amyloid peptide with fibrinogen and coagulation factor XII may contribute to Alzheimer's disease. Curr Opin Hematol 2018; 24:427-431. [PMID: 28661939 DOI: 10.1097/moh.0000000000000368] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
PURPOSE OF REVIEW To review the evidence that the Alzheimer peptide β-amyloid interacts with the blood coagulation system and influences the pathophysiology of the disease. RECENT FINDINGS β-amyloid can interact with fibrinogen and blood coagulation factor XII and trigger ischemia and inflammation. SUMMARY β-amyloid interacts with fibrinogen and factor XII. These interactions can lead to increased clotting, abnormal clot formation, persistent fibrin deposition, and generation of proinflammatory molecules. These events can damage neurons and could contribute to the cognitive decline in Alzheimer's disease patients.
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Affiliation(s)
- Hyung J Ahn
- aPatricia and John Rosenwald Laboratory of Neurobiology and Genetics, Rockefeller University, New York City bRegeneron Pharmaceuticals, Tarrytown, New York, USA *Hyung J. Ahn, Zu-Lin Chen, and Daria Zamolodchikov contributed equally to this article
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20
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Bester J, Soma P, Kell DB, Pretorius E. Viscoelastic and ultrastructural characteristics of whole blood and plasma in Alzheimer-type dementia, and the possible role of bacterial lipopolysaccharides (LPS). Oncotarget 2016; 6:35284-303. [PMID: 26462180 PMCID: PMC4742105 DOI: 10.18632/oncotarget.6074] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 09/28/2015] [Indexed: 12/22/2022] Open
Abstract
Alzheimer-type dementia (AD) is a neurodegenerative disorder and the most common form of dementia. Patients typically present with neuro- and systemic inflammation and iron dysregulation, associated with oxidative damage that reflects in hypercoagulability. Hypercoagulability is closely associated with increased fibrin(ogen) and in AD patients fibrin(ogen) has been implicated in the development of neuroinflammation and memory deficits. There is still no clear reason precisely why (a) this hypercoagulable state, (b) iron dysregulation and (c) increased fibrin(ogen) could together lead to the loss of neuronal structure and cognitive function. Here we suggest an alternative hypothesis based on previous ultrastructural evidence of the presence of a (dormant) blood microbiome in AD. Furthermore, we argue that bacterial cell wall components, such as the endotoxin lipopolysaccharide (LPS) of Gram-negative strains, might be the cause of the continuing and low-grade inflammation, characteristic of AD. Here, we follow an integrated approach, by studying the viscoelastic and ultrastructural properties of AD plasma and whole blood by using scanning electron microscopy, Thromboelastography (TEG®) and the Global Thrombosis Test (GTT®). Ultrastructural analysis confirmed the presence and close proximity of microbes to erythrocytes. TEG® analysis showed a hypercoagulable state in AD. TEG® results where LPS was added to naive blood showed the same trends as were found with the AD patients, while the GTT® results (where only platelet activity is measured), were not affected by the added LPS, suggesting that LPS does not directly impact platelet function. Our findings reinforce the importance of further investigating the role of LPS in AD.
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Affiliation(s)
- Janette Bester
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Arcadia, South Africa
| | - Prashilla Soma
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Arcadia, South Africa
| | - Douglas B Kell
- School of Chemistry and The Manchester Institute of Biotechnology, The University of Manchester, Manchester, UK
| | - Etheresia Pretorius
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Arcadia, South Africa
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21
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Biochemical and structural analysis of the interaction between β-amyloid and fibrinogen. Blood 2016; 128:1144-51. [PMID: 27389717 DOI: 10.1182/blood-2016-03-705228] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 06/29/2016] [Indexed: 11/20/2022] Open
Abstract
The majority of patients with Alzheimer disease (AD) suffer from impaired cerebral circulation. Accumulating evidence suggests that fibrinogen, the main protein component of blood clots, plays an important role in this circulatory dysfunction in AD. Fibrinogen interacts with β-amyloid (Aβ), forming plasmin-resistant abnormal blood clots, and increased fibrin deposition is found in the brains of AD patients and mouse models. In this study, we investigated the biochemical and structural details of the Aβ-fibrinogen interaction. We identified the central region of Aβ42 as the most critical region for the interaction, which can be inhibited by specific antibodies against the central region of Aβ and by naturally occurring p3 peptides, Aβ17-40 and Aβ17-42. X-ray crystallographic analysis revealed that Aβ42 binding to fragment D of fibrinogen induced a structural change in the C-terminal region of the fibrinogen β-chain (β384-393). Furthermore, we identified an additional Aβ-binding site within the αC region of fibrinogen. Aβ binding to this αC region blocked plasmin-mediated fibrin cleavage at this site, resulting in the generation of increased levels of a plasmin-resistant fibrin degradation fragment. Overall, our study elucidates the Aβ-fibrinogen interaction and clarifies the mechanism by which Aβ-fibrinogen binding delays fibrinolysis by plasmin. These results may facilitate the development of effective therapeutics against the Aβ-fibrinogen interaction to treat cerebrovascular abnormalities in AD.
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