101
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Pretorius E, Bester J, Kell DB. A Bacterial Component to Alzheimer's-Type Dementia Seen via a Systems Biology Approach that Links Iron Dysregulation and Inflammagen Shedding to Disease. J Alzheimers Dis 2018; 53:1237-56. [PMID: 27340854 PMCID: PMC5325058 DOI: 10.3233/jad-160318] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The progression of Alzheimer's disease (AD) is accompanied by a great many observable changes, both molecular and physiological. These include oxidative stress, neuroinflammation, and (more proximal to cognitive decline) the death of neuronal and other cells. A systems biology approach seeks to organize these observed variables into pathways that discriminate those that are highly involved (i.e., causative) from those that are more usefully recognized as bystander effects. We review the evidence that iron dysregulation is one of the central causative pathway elements here, as this can cause each of the above effects. In addition, we review the evidence that dormant, non-growing bacteria are a crucial feature of AD, that their growth in vivo is normally limited by a lack of free iron, and that it is this iron dysregulation that is an important factor in their resuscitation. Indeed, bacterial cells can be observed by ultrastructural microscopy in the blood of AD patients. A consequence of this is that the growing cells can shed highly inflammatory components such as lipopolysaccharides (LPS). These too are known to be able to induce (apoptotic and pyroptotic) neuronal cell death. There is also evidence that these systems interact with elements of vitamin D metabolism. This integrative systems approach has strong predictive power, indicating (as has indeed been shown) that both natural and pharmaceutical iron chelators might have useful protective roles in arresting cognitive decline, and that a further assessment of the role of microbes in AD development is more than highly warranted.
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Affiliation(s)
- Etheresia Pretorius
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Arcadia, South Africa
| | - Janette Bester
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Arcadia, South Africa
| | - Douglas B Kell
- School of Chemistry, The University of Manchester, Manchester, Lancs, UK.,The Manchester Institute of Biotechnology, The University of Manchester, Manchester, Lancs, UK.,Centre for Synthetic Biology of Fine and Speciality Chemicals, The University of Manchester, Manchester, Lancs, UK
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102
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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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103
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Miners JS, Schulz I, Love S. Differing associations between Aβ accumulation, hypoperfusion, blood-brain barrier dysfunction and loss of PDGFRB pericyte marker in the precuneus and parietal white matter in Alzheimer's disease. J Cereb Blood Flow Metab 2018; 38:103-115. [PMID: 28151041 PMCID: PMC5757436 DOI: 10.1177/0271678x17690761] [Citation(s) in RCA: 149] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Recent studies implicate loss of pericytes in hypoperfusion and blood-brain barrier (BBB) leakage in Alzheimer's disease (AD). In this study, we have measured levels of the pericyte marker, platelet-derived growth factor receptor-β (PDGFRB), and fibrinogen (to assess blood-brain barrier leakage), and analyzed their relationship to indicators of microvessel density (von Willebrand factor level), ante-mortem oxygenation (myelin-associated glycoprotein:proteolipid protein-1 ratio and vascular endothelial growth factor level), Aβ level and plaque load, in precuneus and underlying white matter from 49 AD to 37 control brains. There was reduction in PDGFRB and increased fibrinogen in the precuneus in AD. These changes correlated with reduction in oxygenation and with plaque load. In the underlying white matter, increased fibrinogen correlated with reduced oxygenation, but PDGFRB level was unchanged. The level of platelet-derived growth factor-ββ (PDGF-BB), important for pericyte maintenance, was increased in AD but mainly in the insoluble tissue fraction, correlating with insoluble Aβ level. Loss of the PDGFRB within the precuneus in AD is associated with fibrinogen leakage and reduced oxygenation, and related to fibrillar Aβ accumulation. In contrast, fibrinogen leakage and reduced oxygenation of underlying white matter occur independently of loss of PDGFRB, perhaps secondary to reduced transcortical perfusion.
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Affiliation(s)
| | | | - Seth Love
- Seth Love, School of Clinical Sciences,
University of Bristol, Learning & Research level 2, Southmead Hospital,
Bristol BS10 5NB, UK.
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104
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In Vivo Imaging of CNS Injury and Disease. J Neurosci 2017; 37:10808-10816. [PMID: 29118209 DOI: 10.1523/jneurosci.1826-17.2017] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 10/02/2017] [Accepted: 10/03/2017] [Indexed: 02/06/2023] Open
Abstract
In vivo optical imaging has emerged as a powerful tool with which to study cellular responses to injury and disease in the mammalian CNS. Important new insights have emerged regarding axonal degeneration and regeneration, glial responses and neuroinflammation, changes in the neurovascular unit, and, more recently, neural transplantations. Accompanying a 2017 SfN Mini-Symposium, here, we discuss selected recent advances in understanding the neuronal, glial, and other cellular responses to CNS injury and disease with in vivo imaging of the rodent brain or spinal cord. We anticipate that in vivo optical imaging will continue to be at the forefront of breakthrough discoveries of fundamental mechanisms and therapies for CNS injury and disease.
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105
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Tailor-made purified human platelet lysate concentrated in neurotrophins for treatment of Parkinson's disease. Biomaterials 2017; 142:77-89. [DOI: 10.1016/j.biomaterials.2017.07.018] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Revised: 07/02/2017] [Accepted: 07/09/2017] [Indexed: 12/18/2022]
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106
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Kell DB, Pretorius E. To What Extent Are the Terminal Stages of Sepsis, Septic Shock, Systemic Inflammatory Response Syndrome, and Multiple Organ Dysfunction Syndrome Actually Driven by a Prion/Amyloid Form of Fibrin? Semin Thromb Hemost 2017; 44:224-238. [PMID: 28778104 PMCID: PMC6193370 DOI: 10.1055/s-0037-1604108] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
A well-established development of increasing disease severity leads from sepsis through systemic inflammatory response syndrome, septic shock, multiple organ dysfunction syndrome, and cellular and organismal death. Less commonly discussed are the equally well-established coagulopathies that accompany this. We argue that a lipopolysaccharide-initiated (often disseminated intravascular) coagulation is accompanied by a proteolysis of fibrinogen such that formed fibrin is both inflammatory and resistant to fibrinolysis. In particular, we argue that the form of fibrin generated is amyloid in nature because much of its normal α-helical content is transformed to β-sheets, as occurs with other proteins in established amyloidogenic and prion diseases. We hypothesize that these processes of amyloidogenic clotting and the attendant coagulopathies play a role in the passage along the aforementioned pathways to organismal death, and that their inhibition would be of significant therapeutic value, a claim for which there is considerable emerging evidence.
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Affiliation(s)
- Douglas B Kell
- School of Chemistry, The University of Manchester, Manchester, United Kingdom.,Manchester Institute of Biotechnology, The University of Manchester, Manchester, United Kingdom.,Centre for Synthetic Biology of Fine and Speciality Chemicals, The University of Manchester, Manchester, United Kingdom
| | - Etheresia Pretorius
- Department of Physiological Sciences, Stellenbosch University, Matieland, South Africa
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107
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Thomas R, Morris AW, Tai LM. Epidermal growth factor prevents APOE4-induced cognitive and cerebrovascular deficits in female mice. Heliyon 2017; 3:e00319. [PMID: 28626809 PMCID: PMC5463012 DOI: 10.1016/j.heliyon.2017.e00319] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 05/15/2017] [Accepted: 05/31/2017] [Indexed: 02/07/2023] Open
Abstract
Cerebrovascular dysfunction is re-emerging as a major component of aging, and may contribute to the risk of developing Alzheimer's disease (AD). Two important risk factors for cerebrovascular dysfunction are APOE and female sex, which are primarily researched in the context of high amyloid-β (Aβ) levels as found in AD. However, APOE4 and sex modulate Aβ-independent pathways that may induce cerebrovascular dysfunction as a downstream consequence. Therefore, testing the activity of factors that target cerebrovascular dysfunction in Aβ-independent models that incorporate APOE4 and female sex is crucial. We have previously demonstrated that peripheral administration of the epidermal growth factor (EGF) prevents cognitive dysfunction, cerebrovascular leakiness, and cerebrovascular coverage deficits in female mice that express APOE4 and overproduce Aβ, without affecting Aβ levels. These data raise the question of whether EGF protects the cerebrovasculature from general stress-induced damage. Therefore, the goal of this study was to determine whether EGF prevents Aβ-independent cerebrovascular dysfunction. In eight-month old mice that express human APOE, the interaction of APOE4 and female sex induced cognitive dysfunction, increased cerebrovascular leakiness and lowered vessel coverage. Importantly, in a prevention paradigm (from six to eight and a half months of age), EGF ameliorated cognitive decline and cerebrovascular deficits in female mice that express APOE4. Thus, developing treatment strategies based on EGF signaling could provide alternative therapeutic options for age-related cerebrovascular dysfunction and reduce AD risk.
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Affiliation(s)
| | | | - Leon M. Tai
- Department of Anatomy and Cell Biology, University of Illinois, Chicago, IL 60612, USA
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108
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Michalicova A, Galba J, Novak M, Kovac A. Determination of Evans blue as a blood–brain barrier integrity tracer in plasma and brain tissue by UHPLC/UV method. J LIQ CHROMATOGR R T 2017. [DOI: 10.1080/10826076.2017.1320289] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Alena Michalicova
- Institute of Neuroimmunology, Slovak Academy of Sciences, Bratislava, Slovak Republic
- AXON Neuroscience R&D, Bratislava, Slovak Republic
| | - Jaroslav Galba
- AXON Neuroscience R&D, Bratislava, Slovak Republic
- Faculty of Pharmacy of Comenius University, Department of Pharmaceutical Analysis and Nuclear Pharmacy, Bratislava, Slovak Republic
| | - Michal Novak
- Institute of Neuroimmunology, Slovak Academy of Sciences, Bratislava, Slovak Republic
- AXON Neuroscience R&D, Bratislava, Slovak Republic
| | - Andrej Kovac
- Institute of Neuroimmunology, Slovak Academy of Sciences, Bratislava, Slovak Republic
- AXON Neuroscience R&D, Bratislava, Slovak Republic
- Department of Pharmacology and Toxicology, The University of Veterinary Medicine and Pharmacy, Kosice, Slovak Republic
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109
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Vascular protective effects of KLF2 on Aβ-induced toxicity: Implications for Alzheimer’s disease. Brain Res 2017; 1663:174-183. [DOI: 10.1016/j.brainres.2017.01.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2016] [Revised: 12/29/2016] [Accepted: 01/02/2017] [Indexed: 11/19/2022]
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110
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Zamolodchikov D, Strickland S. A possible new role for Aβ in vascular and inflammatory dysfunction in Alzheimer's disease. Thromb Res 2017; 141 Suppl 2:S59-61. [PMID: 27207427 DOI: 10.1016/s0049-3848(16)30367-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Alzheimer's disease (AD) is often characterized by vascular pathology, a procoagulant state, and chronic inflammation. The mechanisms behind these abnormalities in AD are not clear. Here, we review evidence for the role of the AD-associated peptide Aβ in promoting inflammation and thrombosis in AD via its interaction with the circulating proteins factor XII and fibrinogen.
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Affiliation(s)
- Daria Zamolodchikov
- Laboratory of Neurobiology and Genetics; The Rockefeller University; New York, NY 10065, USA
| | - Sidney Strickland
- Laboratory of Neurobiology and Genetics; The Rockefeller University; New York, NY 10065, USA.
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111
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Idell RD, Florova G, Komissarov AA, Shetty S, Girard RBS, Idell S. The fibrinolytic system: A new target for treatment of depression with psychedelics. Med Hypotheses 2017; 100:46-53. [PMID: 28236848 DOI: 10.1016/j.mehy.2017.01.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 11/10/2016] [Accepted: 01/21/2017] [Indexed: 12/28/2022]
Abstract
Current understanding of the neurobiology of depression has grown over the past few years beyond the traditional monoamine theory of depression to include chronic stress, inflammation and disrupted synaptic plasticity. Tissue plasminogen activator (tPA) is a key factor that not only promotes fibrinolysis via the activation of plasminogen, but also contributes to regulation of synaptic plasticity and neurogenesis through plasmin-mediated activation of a probrain derived neurotrophic factor (BDNF) to mature BDNF. ProBDNF activation could potentially be supressed by competition with fibrin for plasmin and tPA. High affinity binding of plasmin and tPA to fibrin could result in a decrease of proBDNF activation during brain inflammation leading to fibrosis further perpetuating depressed mood. There is a paucity of data explaining the possible role of the fibrinolytic system or aberrant extravascular fibrin deposition in depression. We propose that within the brain, an imbalance between tPA and urokinase plasminogen activator (uPA) and plasminogen activator inhibitor-1 (PAI-1) and neuroserpin favors the inhibitors, resulting in changes in neurogenesis, synaptic plasticity, and neuroinflammation that result in depressive behavior. Our hypothesis is that peripheral inflammation mediates neuroinflammation, and that cytokines such as tumor necrosis factor alpha (TNF-α) can inhibit the fibrinolytic system by up- regulating PAI-1 and potentially neuroserpin. We propose that the decrement of the activity of tPA and uPA occurs with downregulation of uPA in part involving the binding and clearance from the surface of neural cells of uPA/PAI-1 complexes by the urokinase receptor uPAR. We infer that current antidepressants and ketamine mitigate depressive symptoms by restoring the balance of the fibrinolytic system with increased activity of tPA and uPA with down-regulated intracerebral expression of their inhibitors. We lastly hypothesize that psychedelic 5-ht2a receptor agonists, such as psilocybin, can improve mood through anti- inflammatory and pro-fibrinolytic effects that include blockade of TNF-α activity leading to decreased PAI-1 activity and increased clearance. The process involves disinhibition of tPA and uPA with subsequent increased cleavage of proBDNF which promotes neurogenesis, decreased neuroinflammation, decreased fibrin deposition, normalized glial-neuronal cross-talk, and optimally functioning neuro-circuits involved in mood. We propose that psilocybin can alleviate deleterious changes in the brain caused by chronic stress leading to restoration of homeostatic brain fibrinolytic capacity leading to euthymia.
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Affiliation(s)
- R D Idell
- Department of Behavioral Health, Child and Adolescent Psychiatry, The University of Texas Health Science Center at Tyler, 11937 US HWY 271, Tyler, TX 75708, United States.
| | - G Florova
- Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, 11937 US HWY 271, Tyler, TX 75708, United States
| | - A A Komissarov
- Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, 11937 US HWY 271, Tyler, TX 75708, United States
| | - S Shetty
- Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, 11937 US HWY 271, Tyler, TX 75708, United States
| | - R B S Girard
- Biotechnology Graduate Program, The University of Texas Health Science Center at Tyler, 11937 US HWY 271, Tyler, TX 75708, United States
| | - S Idell
- Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, 11937 US HWY 271, Tyler, TX 75708, United States
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112
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Depletion of coagulation factor XII ameliorates brain pathology and cognitive impairment in Alzheimer disease mice. Blood 2017; 129:2547-2556. [PMID: 28242605 DOI: 10.1182/blood-2016-11-753202] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 02/21/2017] [Indexed: 12/21/2022] Open
Abstract
Vascular abnormalities and inflammation are found in many Alzheimer disease (AD) patients, but whether these changes play a causative role in AD is not clear. The factor XII (FXII) -initiated contact system can trigger both vascular pathology and inflammation and is activated in AD patients and AD mice. We have investigated the role of the contact system in AD pathogenesis. Cleavage of high-molecular-weight kininogen (HK), a marker for activation of the inflammatory arm of the contact system, is increased in a mouse model of AD, and this cleavage is temporally correlated with the onset of brain inflammation. Depletion of FXII in AD mice inhibited HK cleavage in plasma and reduced neuroinflammation, fibrinogen deposition, and neurodegeneration in the brain. Moreover, FXII-depleted AD mice showed better cognitive function than untreated AD mice. These results indicate that FXII-mediated contact system activation contributes to AD pathogenesis, and therefore this system may offer novel targets for AD treatment.
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113
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Müller K, Courtois G, Ursini MV, Schwaninger M. New Insight Into the Pathogenesis of Cerebral Small-Vessel Diseases. Stroke 2017; 48:520-527. [PMID: 28082670 DOI: 10.1161/strokeaha.116.012888] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Kristin Müller
- From the Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Germany (K.M., M.S.); INSERM U1038/BIG, CEA, Grenoble, France (G.C.); and Institute of Genetics and Biophysics, "Adriano Buzzati-Traverso", IGB-CNR, Naples, Italy (M.V.U.)
| | - Gilles Courtois
- From the Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Germany (K.M., M.S.); INSERM U1038/BIG, CEA, Grenoble, France (G.C.); and Institute of Genetics and Biophysics, "Adriano Buzzati-Traverso", IGB-CNR, Naples, Italy (M.V.U.)
| | - Matilde Valeria Ursini
- From the Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Germany (K.M., M.S.); INSERM U1038/BIG, CEA, Grenoble, France (G.C.); and Institute of Genetics and Biophysics, "Adriano Buzzati-Traverso", IGB-CNR, Naples, Italy (M.V.U.)
| | - Markus Schwaninger
- From the Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Germany (K.M., M.S.); INSERM U1038/BIG, CEA, Grenoble, France (G.C.); and Institute of Genetics and Biophysics, "Adriano Buzzati-Traverso", IGB-CNR, Naples, Italy (M.V.U.).
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114
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Proteins behaving badly. Substoichiometric molecular control and amplification of the initiation and nature of amyloid fibril formation: lessons from and for blood clotting. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2017; 123:16-41. [DOI: 10.1016/j.pbiomolbio.2016.08.006] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2016] [Revised: 08/14/2016] [Accepted: 08/19/2016] [Indexed: 02/08/2023]
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115
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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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116
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Ganske S, Haussmann R, Gruschwitz A, Werner A, Osterrath A, Baumgaertel J, Lange J, Donix KL, Linn J, Donix M. Family History of Alzheimer's Disease and Cortical Thickness in Patients With Dementia. Am J Alzheimers Dis Other Demen 2016; 31:450-6. [PMID: 27303063 PMCID: PMC10852676 DOI: 10.1177/1533317516653827] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2024]
Abstract
A first-degree family history of Alzheimer's disease reflects genetic risks for the neurodegenerative disorder. Recent imaging data suggest localized effects of genetic risks on brain structure in healthy people. It is unknown whether this association can also be found in patients who already have dementia. Our aim was to investigate whether family history risk modulates regional medial temporal lobe cortical thickness in patients with Alzheimer's disease. We performed high-resolution magnetic resonance imaging and cortical unfolding data analysis on 54 patients and 53 nondemented individuals. A first-degree family history of Alzheimer's disease was associated with left hemispheric cortical thinning in the subiculum among patients and controls. The contribution of Alzheimer's disease family history to regional brain anatomy changes independent of cognitive impairment may reflect genetic risks that modulate onset and clinical course of the disease.
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Affiliation(s)
- Steffi Ganske
- Department of Psychiatry, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Robert Haussmann
- Department of Psychiatry, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Antonia Gruschwitz
- Department of Psychiatry, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Annett Werner
- Department of Neuroradiology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Antje Osterrath
- Department of Psychiatry, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany DZNE, German Center for Neurodegenerative Diseases, Dresden, Germany
| | - Johanna Baumgaertel
- Department of Psychiatry, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Jan Lange
- Department of Psychiatry, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Katharina L Donix
- Department of Psychiatry, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Jennifer Linn
- Department of Neuroradiology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Markus Donix
- Department of Psychiatry, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany DZNE, German Center for Neurodegenerative Diseases, Dresden, Germany
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117
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Abstract
In this issue of Blood, Motley et al have identified a novel and unexpected mechanism for clearance of extravascular fibrin that is accomplished by a specific proinflammatory macrophage population and is dependent upon active plasmin, yet independent of known fibrinogen receptors.
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118
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Aso E, Serrano AL, Muñoz-Cánoves P, Ferrer I. Fibrinogen-Derived γ377-395 Peptide Improves Cognitive Performance and Reduces Amyloid-β Deposition, without Altering Inflammation, in AβPP/PS1 Mice. J Alzheimers Dis 2016; 47:403-12. [PMID: 26401562 DOI: 10.3233/jad-142928] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Fibrinogen has emerged as a promising therapeutic target against Alzheimer's disease because of its dual role in altered vascular function and amyloid-β aggregation. Here we provide evidence regarding cognitive improvement and reduction of brain parenchyma amyloid-β deposition in AβPP/PS1 mice after treatment for one month with the fibrinogen-blocking peptide Fibγ377-395. No alteration in glial response or other neuroinflammatory markers was observed in the cortex of treated animals. Considering these results and the fact that Fibγ377-395 does not affect coagulation function, this peptide could be considered as a promising and safe candidate for chronic treatment of Alzheimer's disease.
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Affiliation(s)
- Ester Aso
- Institut de Neuropatologia, Servei d'Anatomia Patològica, IDIBELL-Hospital Universitari de Bellvitge, Universitat de Barcelona, L'Hospitalet de Llobregat, Spain.,CIBERNED, Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas, Instituto Carlos III, Spain
| | - Antonio L Serrano
- CIBERNED, Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas, Instituto Carlos III, Spain.,Cell Biology Group, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Spain
| | - Pura Muñoz-Cánoves
- CIBERNED, Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas, Instituto Carlos III, Spain.,Cell Biology Group, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Spain.,Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - Isidro Ferrer
- Institut de Neuropatologia, Servei d'Anatomia Patològica, IDIBELL-Hospital Universitari de Bellvitge, Universitat de Barcelona, L'Hospitalet de Llobregat, Spain.,CIBERNED, Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas, Instituto Carlos III, Spain
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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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Chung YC, Kruyer A, Yao Y, Feierman E, Richards A, Strickland S, Norris EH. Hyperhomocysteinemia exacerbates Alzheimer's disease pathology by way of the β-amyloid fibrinogen interaction. J Thromb Haemost 2016; 14:1442-52. [PMID: 27090576 PMCID: PMC4949110 DOI: 10.1111/jth.13340] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 03/31/2016] [Indexed: 01/02/2023]
Abstract
UNLABELLED Essentials Evidence suggests a comorbidity between hyperhomocysteinemia (HHC) and Alzheimer's disease (AD). Homocysteine (HC) could affect the β-amyloid (Aβ)-fibrinogen interaction in AD pathology. AD patients with concomitant HHC have increased fibrin and Aβ deposits in their brains. HC contributes to AD pathology via the Aβ-fibrinogen interaction. SUMMARY Background Accumulating clinical evidence suggests that hyperhomocysteinemia (HHC) is correlated with Alzheimer's disease (AD) and vascular dementia. Objective This study was carried out to elucidate the specific role of elevated homocysteine (HC) levels in AD pathophysiology. Methods Immunohistochemistry was used to examine β-amyloid (Aβ) deposition along blood vessels, also known as cerebral amyloid angiopathy (CAA), fibrin(ogen) deposition, and their correlation to each other in the brains of AD patients with and without HHC. To study AD-HHC co-morbidity in detail, an AD mouse model was administered a high methionine diet for several months. Parenchymal Aβ plaques, CAA-positive vessels and fibrin deposits were then assessed by immunohistochemistry at different stages of AD progression. Memory deficits were evaluated with contextual fear conditioning and the Barnes maze. Additionally, the effect of HC and its metabolite, homocysteine thiolactone (HCTL), on the Aβ-fibrinogen interaction was analyzed by pull-down, ELISA and fibrin clot formation and fibrinolysis assays in vitro. Results We found increased fibrin(ogen) levels and Aβ deposits in the blood vessels and brain parenchyma of AD patients with HHC. We demonstrate that HC and HCTL enhance the interaction between fibrinogen and Aβ, promote the formation of tighter fibrin clots and delay clot fibrinolysis. Additionally, we show that diet-induced HHC in an AD mouse model leads to severe CAA and parenchymal Aβ deposition, as well as significant impairments in learning and memory. Conclusions These findings suggest that elevated levels of plasma HC/HCTL contribute to AD pathology via the Aβ-fibrin(ogen) interaction.
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Affiliation(s)
- Young Cheul Chung
- Patricia and John Rosenwald Laboratory of Neurobiology & Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Anna Kruyer
- Patricia and John Rosenwald Laboratory of Neurobiology & Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Yao Yao
- Patricia and John Rosenwald Laboratory of Neurobiology & Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Emily Feierman
- Patricia and John Rosenwald Laboratory of Neurobiology & Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Allison Richards
- Patricia and John Rosenwald Laboratory of Neurobiology & Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Sidney Strickland
- Patricia and John Rosenwald Laboratory of Neurobiology & Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Erin H. Norris
- Patricia and John Rosenwald Laboratory of Neurobiology & Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
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121
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A semi-mechanism approach based on MRI and proteomics for prediction of conversion from mild cognitive impairment to Alzheimer's disease. Sci Rep 2016; 6:26712. [PMID: 27273250 PMCID: PMC4896009 DOI: 10.1038/srep26712] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 05/04/2016] [Indexed: 01/18/2023] Open
Abstract
Mild cognitive impairment (MCI) is a precursor phase of Alzheimer’s disease (AD). As current treatments may be effective only at the early stages of AD, it is important to track MCI patients who will convert to AD. The aim of this study is to develop a high performance semi-mechanism based approach to predict the conversion from MCI to AD and improve our understanding of MCI-to-AD conversion mechanism. First, analysis of variance (ANOVA) test and lasso regression are employed to identify the markers related to the conversion. Then the Bayesian network based on selected markers is established to predict MCI-to-AD conversion. The structure of Bayesian network suggests that the conversion may start with fibrin clot formation, verbal memory impairment, eating pattern changing and hyperinsulinemia. The Bayesian network achieves a high 10-fold cross-validated prediction performance with 96% accuracy, 95% sensitivity, 65% specificity, area under the receiver operating characteristic curve of 0.82 on data from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) database. The semi-mechanism based approach provides not only high prediction performance but also clues of mechanism for MCI-to-AD conversion.
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122
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Sonkar V, Kulkarni PP, Chaurasia SN, Dash A, Jauhari A, Parmar D, Yadav S, Dash D. Plasma Fibrinogen Is a Natural Deterrent to Amyloid Beta-Induced Platelet Activation. Mol Med 2016; 22:224-232. [PMID: 27262026 DOI: 10.2119/molmed.2016.00003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 05/02/2016] [Indexed: 12/20/2022] Open
Abstract
Alzheimer's disease (AD) is a devastating neurodegenerative disorder, characterized by extensive loss of neurons, and deposition of amyloid beta (Aβ) in the form of extracellular plaques. Aβ is considered to have critical role in synaptic loss and neuronal death underlying cognitive decline. Platelets contribute to 95% of circulating amyloid-precursor protein that releases Aβ into circulation. We have recently demonstrated that, Aβ active fragment containing amino acid sequence 25-35 (Aβ25-35) is highly thrombogenic in nature, and elicits strong aggregation of washed human platelets in RhoA-dependent manner. In the present study we evaluated the influence of fibrinogen on Aβ-induced platelet activation. Intriguingly, Aβ failed to induce aggregation of platelets suspended in plasma but not in buffer. Fibrinogen brought about dose-dependent decline in aggregatory response of washed human platelets elicited by Aβ25-35, which could be reversed by increasing doses of Aβ. Fibrinogen also attenuated Aβ-induced platelet responses like secretion, clot retraction, rise in cytosolic Ca+2 and reactive oxygen species (ROS). Fibrinogen prevented intracellular accumulation of full length amyloid beta peptide (Aβ42) in platelets as well as neuronal cells. We conclude that fibrinogen serves as a physiological check against the adverse effects of Aβ by preventing its interaction with cells.
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Affiliation(s)
- Vijay Sonkar
- Department of Biochemistry, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Paresh P Kulkarni
- Department of Biochemistry, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Susheel N Chaurasia
- Department of Biochemistry, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Ayusman Dash
- Indian Institute of Science Education and Research, Kolkata, India
| | - Abhishek Jauhari
- Developmental Toxicology Division, Indian Institute of Toxicological Research, Lucknow, Uttar Pradesh, India
| | - Devendra Parmar
- Developmental Toxicology Division, Indian Institute of Toxicological Research, Lucknow, Uttar Pradesh, India
| | - Sanjay Yadav
- Developmental Toxicology Division, Indian Institute of Toxicological Research, Lucknow, Uttar Pradesh, India
| | - Debabrata Dash
- Department of Biochemistry, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
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Zamolodchikov D, Renné T, Strickland S. The Alzheimer's disease peptide β-amyloid promotes thrombin generation through activation of coagulation factor XII. J Thromb Haemost 2016; 14:995-1007. [PMID: 26613657 PMCID: PMC4870142 DOI: 10.1111/jth.13209] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2015] [Accepted: 11/12/2015] [Indexed: 11/30/2022]
Abstract
UNLABELLED Essentials How the Alzheimer's disease (AD) peptide β-amyloid (Aβ) disrupts neuronal function in the disease is unclear. Factor (F) XII initiates blood clotting via FXI, and thrombosis has been implicated in AD. Aβ triggers FXII-dependent FXI and thrombin activation, evidence of which is seen in AD plasma. Aβ-triggered clotting could contribute to neuronal dysfunction in AD and be a novel therapeutic target. SUMMARY Background β-Amyloid (Aβ) is a key pathologic element in Alzheimer's disease (AD), but the mechanisms by which it disrupts neuronal function in vivo are not completely understood. AD is characterized by a prothrombotic state, which could contribute to neuronal dysfunction by affecting cerebral blood flow and inducing inflammation. The plasma protein factor XII triggers clot formation via the intrinsic coagulation cascade, and has been implicated in thrombosis. Objectives To investigate the potential for Aβ to contribute to a prothrombotic state. Methods and results We show that Aβ activates FXII, resulting in FXI activation and thrombin generation in human plasma, thereby establishing Aβ as a possible driver of prothrombotic states. We provide evidence for this process in AD by demonstrating decreased levels of FXI and its inhibitor C1 esterase inhibitor in AD patient plasma, suggesting chronic activation, inhibition and clearance of FXI in AD. Activation of the intrinsic coagulation pathway in AD is further supported by elevated fibrin levels in AD patient plasma. Conclusions The ability of Aβ to promote coagulation via the FXII-driven contact system identifies new mechanisms by which it could contribute to neuronal dysfunction and suggests potential new therapeutic targets in AD.
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Affiliation(s)
- Daria Zamolodchikov
- Patricia and John Rosenwald Laboratory of Neurobiology and Genetics, The Rockefeller University, New York, NY 10065, USA
| | - Thomas Renné
- Division of Clinical Chemistry, Department of Molecular Medicine and Surgery, Karolinska Institutet and University Hospital, Stockholm S-171 76, Sweden
- Center of Molecular Medicine, Karolinska Institutet and University Hospital, Stockholm, Sweden
- Institute for Clinical Chemistry and Laboratory Medicine, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Sidney Strickland
- Patricia and John Rosenwald Laboratory of Neurobiology and Genetics, The Rockefeller University, New York, NY 10065, USA
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124
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Schmaier AH. Alzheimer disease is in part a thrombohemorrhagic disorder. J Thromb Haemost 2016; 14:991-4. [PMID: 26817920 DOI: 10.1111/jth.13277] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 01/12/2016] [Indexed: 12/23/2022]
Affiliation(s)
- A H Schmaier
- Department of Medicine, Case Western Reserve University and University Hospital Case Medical Center, Cleveland, OH, USA
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125
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Nelson AR, Sweeney MD, Sagare AP, Zlokovic BV. Neurovascular dysfunction and neurodegeneration in dementia and Alzheimer's disease. BIOCHIMICA ET BIOPHYSICA ACTA 2016; 1862:887-900. [PMID: 26705676 PMCID: PMC4821735 DOI: 10.1016/j.bbadis.2015.12.016] [Citation(s) in RCA: 360] [Impact Index Per Article: 45.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 12/10/2015] [Accepted: 12/10/2015] [Indexed: 02/07/2023]
Abstract
Vascular insults can initiate a cascade of molecular events leading to neurodegeneration, cognitive impairment, and dementia. Here, we review the cellular and molecular mechanisms in cerebral blood vessels and the pathophysiological events leading to cerebral blood flow dysregulation and disruption of the neurovascular unit and the blood-brain barrier, which all may contribute to the onset and progression of dementia and Alzheimer's disease (AD). Particularly, we examine the link between neurovascular dysfunction and neurodegeneration including the effects of AD genetic risk factors on cerebrovascular functions and clearance of Alzheimer's amyloid-β peptide toxin, and the impact of vascular risk factors, environment, and lifestyle on cerebral blood vessels, which in turn may affect synaptic, neuronal, and cognitive functions. Finally, we examine potential experimental treatments for dementia and AD based on the neurovascular model, and discuss some critical questions to be addressed by future studies. This article is part of a Special Issue entitled: Vascular Contributions to Cognitive Impairment and Dementia edited by M. Paul Murphy, Roderick A. Corriveau and Donna M. Wilcock.
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Affiliation(s)
- Amy R Nelson
- Department of Physiology and Biophysics and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90089, USA
| | - Melanie D Sweeney
- Department of Physiology and Biophysics and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90089, USA
| | - Abhay P Sagare
- Department of Physiology and Biophysics and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90089, USA
| | - Berislav V Zlokovic
- Department of Physiology and Biophysics and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90089, USA.
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126
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The neuropathology and cerebrovascular mechanisms of dementia. J Cereb Blood Flow Metab 2016; 36:172-86. [PMID: 26174330 PMCID: PMC4758551 DOI: 10.1038/jcbfm.2015.164] [Citation(s) in RCA: 258] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 06/12/2015] [Accepted: 06/15/2015] [Indexed: 12/23/2022]
Abstract
The prevalence of dementia is increasing in our aging population at an alarming rate. Because of the heterogeneity of clinical presentation and complexity of disease neuropathology, dementia classifications remain controversial. Recently, the National Plan to address Alzheimer’s Disease prioritized Alzheimer’s disease-related dementias to include: Alzheimer’s disease, dementia with Lewy bodies, frontotemporal dementia, vascular dementia, and mixed dementias. While each of these dementing conditions has their unique pathologic signature, one common etiology shared among all these conditions is cerebrovascular dysfunction at some point during the disease process. The goal of this comprehensive review is to summarize the current findings in the field and address the important contributions of cerebrovascular, physiologic, and cellular alterations to cognitive impairment in these human dementias. Specifically, evidence will be presented in support of small-vessel disease as an underlying neuropathologic hallmark of various dementias, while controversial findings will also be highlighted. Finally, the molecular mechanisms shared among all dementia types including hypoxia, oxidative stress, mitochondrial bioenergetics, neuroinflammation, neurodegeneration, and blood–brain barrier permeability responsible for disease etiology and progression will be discussed.
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127
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Bardehle S, Rafalski VA, Akassoglou K. Breaking boundaries-coagulation and fibrinolysis at the neurovascular interface. Front Cell Neurosci 2015; 9:354. [PMID: 26441525 PMCID: PMC4584986 DOI: 10.3389/fncel.2015.00354] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 08/24/2015] [Indexed: 12/20/2022] Open
Abstract
Blood proteins at the neurovascular unit (NVU) are emerging as important molecular determinants of communication between the brain and the immune system. Over the past two decades, roles for the plasminogen activation (PA)/plasmin system in fibrinolysis have been extended from peripheral dissolution of blood clots to the regulation of central nervous system (CNS) functions in physiology and disease. In this review, we discuss how fibrin and its proteolytic degradation affect neuroinflammatory, degenerative and repair processes. In particular, we focus on novel functions of fibrin—the final product of the coagulation cascade and the main substrate of plasmin—in the activation of immune responses and trafficking of immune cells into the brain. We also comment on the suitability of the coagulation and fibrinolytic systems as potential biomarkers and drug targets in diseases, such as multiple sclerosis (MS), Alzheimer’s disease (AD) and stroke. Studying coagulation and fibrinolysis as major molecular pathways that regulate cellular functions at the NVU has the potential to lead to the development of novel strategies for the detection and treatment of neurologic diseases.
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Affiliation(s)
- Sophia Bardehle
- Gladstone Institute of Neurological Disease, University of California, San Francisco San Francisco, CA, USA
| | - Victoria A Rafalski
- Gladstone Institute of Neurological Disease, University of California, San Francisco San Francisco, CA, USA
| | - Katerina Akassoglou
- Gladstone Institute of Neurological Disease, University of California, San Francisco San Francisco, CA, USA ; Department of Neurology, University of California, San Francisco San Francisco, CA, USA
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128
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Narayan PJ, Kim SL, Lill C, Feng S, Faull RLM, Curtis MA, Dragunow M. Assessing fibrinogen extravasation into Alzheimer's disease brain using high-content screening of brain tissue microarrays. J Neurosci Methods 2015; 247:41-9. [PMID: 25813427 DOI: 10.1016/j.jneumeth.2015.03.017] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Revised: 03/10/2015] [Accepted: 03/12/2015] [Indexed: 12/21/2022]
Abstract
BACKGROUND Tissue microarrays are commonly used to evaluate disease pathology however methods to automate and quantify pathological changes are limited. NEW METHOD This article demonstrates the utility of the VSlide scanner (MetaSystems) for automated image acquisition from immunolabelled tissue microarray slides, and subsequent automated image analysis with MetaXpress (Molecular Devices) software to obtain objective, efficient and reproducible data from immunolabelled tissue microarray sections. RESULTS Significant increases in fibrinogen immunolabelling were observed in 29 Alzheimer's disease cases compared to 28 control cases analysed from a single tissue microarray slide. Western blot analysis also demonstrated significant increases in fibrinogen immunolabelling in 6 Alzheimer's cases compared to 6 control cases. The observed changes were also validated with gold standard blinded manual H-scoring. COMPARISON WITH EXISTING METHOD VSlide Metafer software offers a 'tissue microarray acquisition' plugin for easy mapping of tissue cores with their original position on the tissue microarray map. High resolution VSlide images are compatible with MetaXpress image analysis software. This article details the coupling of these two technologies to accurately and reproducibly analyse immunolabelled tissue microarrays within minutes, compared to the gold standard method of manual counting using H-scores which is significantly slower and prone to inter-observer variation. CONCLUSIONS Here, we couple brain tissue microarray technology with high-content screening and automated image analysis as a powerful way to address bottle necks in data generation and improve throughput, as well as sensitivity to study biological/pathological changes in brain disease.
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Affiliation(s)
- Pritika J Narayan
- Gravida, National Centre for Growth and Development, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand; Centre for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand; Biomedical Imaging Research Unit, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Sue-Ling Kim
- Centre for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Claire Lill
- Centre for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Sheryl Feng
- Centre for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Richard L M Faull
- Centre for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Maurice A Curtis
- Centre for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Michael Dragunow
- Gravida, National Centre for Growth and Development, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand; Centre for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand.
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Abstract
Fibrin-specific targeting capabilities have been highly sought for over 50 years due to their implications for bio-molecule delivery, diagnostics, and regenerative medicine. Yet only recently has our full knowledge of fibrin's complex polymerization dynamics and biological interactions begun to be fully exploited in pursuit of this goal. This highlight will discuss the range of rapidly changing strategies for specifically targeting fibrin over the precursor fibrinogen and the advantages and disadvantages of these approaches for various applications.
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Affiliation(s)
- Victoria L. Stefanelli
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, USA
| | - Thomas H. Barker
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, USA
- The Parker H. Petit Institute for Bioengineering and biosciences, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
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