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Husain KH, Sarhan SF, AlKhalifa HKAA, Buhasan A, Moin ASM, Butler AE. Dementia in Diabetes: The Role of Hypoglycemia. Int J Mol Sci 2023; 24:9846. [PMID: 37372995 DOI: 10.3390/ijms24129846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 05/25/2023] [Accepted: 05/26/2023] [Indexed: 06/29/2023] Open
Abstract
Hypoglycemia, a common consequence of diabetes treatment, is associated with severe morbidity and mortality and has become a major barrier to intensifying antidiabetic therapy. Severe hypoglycemia, defined as abnormally low blood glucose requiring the assistance of another person, is associated with seizures and comas, but even mild hypoglycemia can cause troubling symptoms such as anxiety, palpitations, and confusion. Dementia generally refers to the loss of memory, language, problem-solving, and other cognitive functions, which can interfere with daily life, and there is growing evidence that diabetes is associated with an increased risk of both vascular and non-vascular dementia. Neuroglycopenia resulting from a hypoglycemic episode in diabetic patients can lead to the degeneration of brain cells, with a resultant cognitive decline, leading to dementia. In light of new evidence, a deeper understating of the relationship between hypoglycemia and dementia can help to inform and guide preventative strategies. In this review, we discuss the epidemiology of dementia among patients with diabetes, and the emerging mechanisms thought to underlie the association between hypoglycemia and dementia. Furthermore, we discuss the risks of various pharmacological therapies, emerging therapies to combat hypoglycemia-induced dementia, as well as risk minimization strategies.
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Affiliation(s)
- Khaled Hameed Husain
- School of Medicine, Royal College of Surgeons in Ireland, Busaiteen, Adliya 15503, Bahrain
| | - Saud Faisal Sarhan
- School of Medicine, Royal College of Surgeons in Ireland, Busaiteen, Adliya 15503, Bahrain
| | | | - Asal Buhasan
- School of Medicine, Royal College of Surgeons in Ireland, Busaiteen, Adliya 15503, Bahrain
| | - Abu Saleh Md Moin
- Research Department, Royal College of Surgeons in Ireland, Busaiteen, Adliya 15503, Bahrain
| | - Alexandra E Butler
- Research Department, Royal College of Surgeons in Ireland, Busaiteen, Adliya 15503, Bahrain
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Golderman V, Goldberg Z, Gofrit SG, Dori A, Maggio N, Chapman J, Sher I, Rotenstreich Y, Shavit-Stein E. PARIN5, a Novel Thrombin Receptor Antagonist Modulates a Streptozotocin Mice Model for Diabetic Encephalopathy. Int J Mol Sci 2023; 24:ijms24032021. [PMID: 36768341 PMCID: PMC9917200 DOI: 10.3390/ijms24032021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 01/16/2023] [Accepted: 01/17/2023] [Indexed: 01/22/2023] Open
Abstract
Diabetic encephalopathy (DE) is an inflammation-associated diabetes mellitus (DM) complication. Inflammation and coagulation are linked and are both potentially modulated by inhibiting the thrombin cellular protease-activated receptor 1 (PAR1). Our aim was to study whether coagulation pathway modulation affects DE. Diabetic C57BL/6 mice were treated with PARIN5, a novel PAR1 modulator. Behavioral changes in the open field and novel object recognition tests, serum neurofilament (NfL) levels and thrombin activity in central and peripheral nervous system tissue (CNS and PNS, respectively), brain mRNA expression of tumor necrosis factor α (TNF-α), Factor X (FX), prothrombin, and PAR1 were assessed. Subtle behavioral changes were detected in diabetic mice. These were accompanied by an increase in serum NfL, an increase in central and peripheral neural tissue thrombin activity, and TNF-α, FX, and prothrombin brain intrinsic mRNA expression. Systemic treatment with PARIN5 prevented the appearance of behavioral changes, normalized serum NfL and prevented the increase in peripheral but not central thrombin activity. PARIN5 treatment prevented the elevation of both TNF-α and FX but significantly elevated prothrombin expression. PARIN5 treatment prevents behavioral and neural damage in the DE model, suggesting it for future clinical research.
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Affiliation(s)
- Valery Golderman
- Department of Neurology, The Chaim Sheba Medical Center, Ramat Gan 52626202, Israel
- Department of Neurology and Neurosurgery, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Zehavit Goldberg
- Department of Neurology, The Chaim Sheba Medical Center, Ramat Gan 52626202, Israel
- Goldschleger Eye Institute, The Sheba Medical Center, Ramat Gan 52626202, Israel
| | - Shany Guly Gofrit
- Department of Neurology, The Chaim Sheba Medical Center, Ramat Gan 52626202, Israel
| | - Amir Dori
- Department of Neurology, The Chaim Sheba Medical Center, Ramat Gan 52626202, Israel
- Department of Neurology and Neurosurgery, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
- Talpiot Medical Leadership Program, The Chaim Sheba Medical Center, Ramat Gan 52626202, Israel
| | - Nicola Maggio
- Department of Neurology, The Chaim Sheba Medical Center, Ramat Gan 52626202, Israel
- Department of Neurology and Neurosurgery, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
- Talpiot Medical Leadership Program, The Chaim Sheba Medical Center, Ramat Gan 52626202, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Joab Chapman
- Department of Neurology, The Chaim Sheba Medical Center, Ramat Gan 52626202, Israel
- Department of Neurology and Neurosurgery, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
- Robert and Martha Harden Chair in Mental and Neurological Diseases, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Ifat Sher
- Goldschleger Eye Institute, The Sheba Medical Center, Ramat Gan 52626202, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
- The TELEM Rubin Excellence in Biomedical Research Program, The Chaim Sheba Medical Center, Ramat Gan 52626202, Israel
- Department of Ophthalmology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Ygal Rotenstreich
- Goldschleger Eye Institute, The Sheba Medical Center, Ramat Gan 52626202, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
- Department of Ophthalmology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Efrat Shavit-Stein
- Department of Neurology, The Chaim Sheba Medical Center, Ramat Gan 52626202, Israel
- Department of Neurology and Neurosurgery, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
- The TELEM Rubin Excellence in Biomedical Research Program, The Chaim Sheba Medical Center, Ramat Gan 52626202, Israel
- Correspondence: ; Fax: +972-3530-4409
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Araújo B, Caridade-Silva R, Soares-Guedes C, Martins-Macedo J, Gomes ED, Monteiro S, Teixeira FG. Neuroinflammation and Parkinson's Disease-From Neurodegeneration to Therapeutic Opportunities. Cells 2022; 11:cells11182908. [PMID: 36139483 PMCID: PMC9497016 DOI: 10.3390/cells11182908] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 09/10/2022] [Accepted: 09/13/2022] [Indexed: 11/17/2022] Open
Abstract
Parkinson’s disease (PD) is the second most prevalent neurodegenerative disorder worldwide. Clinically, it is characterized by a progressive degeneration of dopaminergic neurons (DAn), resulting in severe motor complications. Preclinical and clinical studies have indicated that neuroinflammation can play a role in PD pathophysiology, being associated with its onset and progression. Nevertheless, several key points concerning the neuroinflammatory process in PD remain to be answered. Bearing this in mind, in the present review, we cover the impact of neuroinflammation on PD by exploring the role of inflammatory cells (i.e., microglia and astrocytes) and the interconnections between the brain and the peripheral system. Furthermore, we discuss both the innate and adaptive immune responses regarding PD pathology and explore the gut–brain axis communication and its influence on the progression of the disease.
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Affiliation(s)
- Bruna Araújo
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal
- ICVS/3B’s-PT Government Associate Laboratory, 4710-057/4805-017 Braga/Guimarães, Portugal
- Medical and Industrial Biotechnology Laboratory (LABMI), Porto Research, Technology, and Innovation Center (PORTIC), Porto Polytechnic Institute, 4200-375 Porto, Portugal
- I3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
| | - Rita Caridade-Silva
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal
- ICVS/3B’s-PT Government Associate Laboratory, 4710-057/4805-017 Braga/Guimarães, Portugal
- Medical and Industrial Biotechnology Laboratory (LABMI), Porto Research, Technology, and Innovation Center (PORTIC), Porto Polytechnic Institute, 4200-375 Porto, Portugal
- I3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
| | - Carla Soares-Guedes
- Medical and Industrial Biotechnology Laboratory (LABMI), Porto Research, Technology, and Innovation Center (PORTIC), Porto Polytechnic Institute, 4200-375 Porto, Portugal
- I3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
| | - Joana Martins-Macedo
- Medical and Industrial Biotechnology Laboratory (LABMI), Porto Research, Technology, and Innovation Center (PORTIC), Porto Polytechnic Institute, 4200-375 Porto, Portugal
- I3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
| | - Eduardo D. Gomes
- Medical and Industrial Biotechnology Laboratory (LABMI), Porto Research, Technology, and Innovation Center (PORTIC), Porto Polytechnic Institute, 4200-375 Porto, Portugal
- I3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
| | - Susana Monteiro
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal
- ICVS/3B’s-PT Government Associate Laboratory, 4710-057/4805-017 Braga/Guimarães, Portugal
| | - Fábio G. Teixeira
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal
- ICVS/3B’s-PT Government Associate Laboratory, 4710-057/4805-017 Braga/Guimarães, Portugal
- Medical and Industrial Biotechnology Laboratory (LABMI), Porto Research, Technology, and Innovation Center (PORTIC), Porto Polytechnic Institute, 4200-375 Porto, Portugal
- I3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
- Correspondence:
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Role of pericytes in blood-brain barrier preservation during ischemia through tunneling nanotubes. Cell Death Dis 2022; 13:582. [PMID: 35790716 PMCID: PMC9256725 DOI: 10.1038/s41419-022-05025-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 06/07/2022] [Accepted: 06/14/2022] [Indexed: 02/07/2023]
Abstract
Crosstalk mechanisms between pericytes, endothelial cells, and astrocytes preserve integrity and function of the blood-brain-barrier (BBB) under physiological conditions. Long intercellular channels allowing the transfer of small molecules and organelles between distant cells called tunneling nanotubes (TNT) represent a potential substrate for energy and matter exchanges between the tripartite cellular compartments of the BBB. However, the role of TNT across BBB cells under physiological conditions and in the course of BBB dysfunction is unknown. In this work, we analyzed the TNT's role in the functional dialog between human brain endothelial cells, and brain pericytes co-cultured with human astrocytes under normal conditions or after exposure to ischemia/reperfusion, a condition in which BBB breakdown occurs, and pericytes participate in the BBB repair. Using live time-lapse fluorescence microscopy and laser-scanning confocal microscopy, we found that astrocytes form long TNT with pericytes and endothelial cells and receive functional mitochondria from both cell types through this mechanism. The mitochondrial transfer also occurred in multicellular assembloids of human BBB that reproduce the three-dimensional architecture of the BBB. Under conditions of ischemia/reperfusion, TNT formation is upregulated, and astrocytes exposed to oxygen-glucose deprivation were rescued from apoptosis by healthy pericytes through TNT-mediated transfer of functional mitochondria, an effect that was virtually abolished in the presence of TNT-destroying drugs. The results establish a functional role of TNT in the crosstalk between BBB cells and demonstrate that TNT-mediated mitochondrial transfer from pericytes rescues astrocytes from ischemia/reperfusion-induced apoptosis. Our data confirm that the pericytes might play a pivotal role in preserving the structural and functional integrity of BBB under physiological conditions and participate in BBB repair in brain diseases.
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Akter T, Annamalai B, Obert E, Simpson KN, Rohrer B. Dabigatran and Wet AMD, Results From Retinal Pigment Epithelial Cell Monolayers, the Mouse Model of Choroidal Neovascularization, and Patients From the Medicare Data Base. Front Immunol 2022; 13:896274. [PMID: 35784301 PMCID: PMC9248746 DOI: 10.3389/fimmu.2022.896274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 05/17/2022] [Indexed: 12/02/2022] Open
Abstract
Background Age-related macular degeneration (AMD), the leading cause of irreversible blindness in elderly Caucasian populations, includes destruction of the blood-retina barrier (BRB) generated by the retinal pigment epithelium-Bruch’s membrane complex (RPE/BrM), and complement activation. Thrombin is likely to get access to those structures upon BRB integrity loss. Here we investigate the potential role of thrombin in AMD by analyzing effects of the thrombin inhibitor dabigatran. Material and Methods MarketScan data for patients aged ≥65 years on Medicare was used to identify association between AMD and dabigatran use. ARPE-19 cells grown as mature monolayers were analyzed for thrombin effects on barrier function (transepithelial resistance; TER) and downstream signaling (complement activation, expression of connective tissue growth factor (CTGF), and secretion of vascular endothelial growth factor (VEGF)). Laser-induced choroidal neovascularization (CNV) in mouse is used to test the identified downstream signaling. Results Risk of new wet AMD diagnosis was reduced in dabigatran users. In RPE monolayers, thrombin reduced TER, generated unique complement C3 and C5 cleavage products, led to C3d/MAC deposition on cell surfaces, and increased CTGF expression via PAR1-receptor activation and VEGF secretion. CNV lesion repair was accelerated by dabigatran, and molecular readouts suggest that downstream effects of thrombin include CTGF and VEGF, but not the complement system. Conclusions This study provides evidence of association between dabigatran use and reduced exudative AMD diagnosis. Based on the cell- and animal-based studies, we suggest that thrombin modulates wound healing and CTGF and VEGF expression, making dabigatran a potential novel treatment option in AMD.
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Affiliation(s)
- Tanjina Akter
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC, United States
- *Correspondence: Tanjina Akter, ; Bärbel Rohrer,
| | | | - Elisabeth Obert
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC, United States
| | - Kit N. Simpson
- Department of Healthcare Leadership and Management, Medical University of South Carolina, Charleston, SC, United States
| | - Bärbel Rohrer
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC, United States
- Department of Neurosciences, Medical University of South Carolina, Charleston, SC, United States
- Ralph H. Johnson VA Medical Center, Division of Research, Charleston, SC, United States
- *Correspondence: Tanjina Akter, ; Bärbel Rohrer,
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Blood-brain barrier leakage in Alzheimer's disease: From discovery to clinical relevance. Pharmacol Ther 2022; 234:108119. [PMID: 35108575 PMCID: PMC9107516 DOI: 10.1016/j.pharmthera.2022.108119] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/14/2022] [Accepted: 01/18/2022] [Indexed: 12/16/2022]
Abstract
Alzheimer's disease (AD) is the most common form of dementia. AD brain pathology starts decades before the onset of clinical symptoms. One early pathological hallmark is blood-brain barrier dysfunction characterized by barrier leakage and associated with cognitive decline. In this review, we summarize the existing literature on the extent and clinical relevance of barrier leakage in AD. First, we focus on AD animal models and their susceptibility to barrier leakage based on age and genetic background. Second, we re-examine barrier dysfunction in clinical and postmortem studies, summarize changes that lead to barrier leakage in patients and highlight the clinical relevance of barrier leakage in AD. Third, we summarize signaling mechanisms that link barrier leakage to neurodegeneration and cognitive decline in AD. Finally, we discuss clinical relevance and potential therapeutic strategies and provide future perspectives on investigating barrier leakage in AD. Identifying mechanistic steps underlying barrier leakage has the potential to unravel new targets that can be used to develop novel therapeutic strategies to repair barrier leakage and slow cognitive decline in AD and AD-related dementias.
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Paul G, Elabi OF. Microvascular Changes in Parkinson’s Disease- Focus on the Neurovascular Unit. Front Aging Neurosci 2022; 14:853372. [PMID: 35360216 PMCID: PMC8960855 DOI: 10.3389/fnagi.2022.853372] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 02/11/2022] [Indexed: 12/27/2022] Open
Abstract
Vascular alterations emerge as a common denominator for several neurodegenerative diseases. In Parkinson’s disease (PD), a number of observations have been made suggesting that the occurrence of vascular pathology is an important pathophysiological aspect of the disease. Specifically, pathological activation of pericytes, blood-brain barrier (BBB) disruption, pathological angiogenesis and vascular regression have been reported. This review summarizes the current evidence for the different vascular alterations in patients with PD and in animal models of PD. We suggest a possible sequence of vascular pathology in PD ranging from early pericyte activation and BBB leakage to an attempt for compensatory angiogenesis and finally vascular rarefication. We highlight different pathogenetic mechanisms that play a role in these vascular alterations including perivascular inflammation and concomitant metabolic disease. Awareness of the contribution of vascular events to the pathogenesis of PD may allow the identification of targets to modulate those mechanisms. In particular the BBB has for decades only been viewed as an obstacle for drug delivery, however, preservation of its integrity and/or modulation of the signaling at this interface between the blood and the brain may prove to be a new avenue to take in order to develop disease-modifying strategies for neurodegenerative disorders.
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Affiliation(s)
- Gesine Paul
- Translational Neurology Group, Department of Clinical Sciences, Lund University, Lund, Sweden
- Department of Neurology, Scania University Hospital, Lund, Sweden
- Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden
- *Correspondence: Gesine Paul,
| | - Osama F. Elabi
- Translational Neurology Group, Department of Clinical Sciences, Lund University, Lund, Sweden
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Kouki MA, Pritchard AB, Alder JE, Crean S. Do Periodontal Pathogens or Associated Virulence Factors Have a Deleterious Effect on the Blood-Brain Barrier, Contributing to Alzheimer's Disease? J Alzheimers Dis 2021; 85:957-973. [PMID: 34897087 DOI: 10.3233/jad-215103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The central nervous system (CNS) is protected by a highly selective barrier, the blood-brain barrier (BBB), that regulates the exchange and homeostasis of bloodborne molecules, excluding xenobiotics. This barrier forms the first line of defense by prohibiting pathogens from crossing to the CNS. Aging and chronic exposure of the BBB to pathogens renders it permeable, and this may give rise to pathology in the CNS such as Alzheimer's disease (AD). Researchers have linked pathogens associated with periodontitis to neuroinflammation and AD-like pathology in vivo and in vitro. Although the presence of periodontitis-associated bacteria has been linked to AD in several clinical studies as DNA and virulence factors were confirmed in brain samples of human AD subjects, the mechanism by which the bacteria traverse to the brain and potentially influences neuropathology is unknown. In this review, we present current knowledge about the association between periodontitis and AD, the mechanism whereby periodontal pathogens might provoke neuroinflammation and how periodontal pathogens could affect the BBB. We suggest future studies, with emphasis on the use of human in vitro models of cells associated with the BBB to unravel the pathway of entry for these bacteria to the CNS and to reveal the molecular and cellular pathways involved in initiating the AD-like pathology. In conclusion, evidence demonstrate that bacteria associated with periodontitis and their virulence factors are capable of inflecting damage to the BBB and have a role in giving rise to pathology similar to that found in AD.
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Affiliation(s)
- Mhd Ammar Kouki
- Brain and Behaviour Centre, Faculty of Clinical and Biomedical Sciences, School of Pharmacy and Biomedical Sciences, University of Central Lancashire, Preston, UK
| | - Anna Barlach Pritchard
- Brain and Behaviour Centre, Faculty of Clinical and Biomedical Sciences, School of Dentistry, University of Central Lancashire, Preston, UK
| | - Jane Elizabeth Alder
- Brain and Behaviour Centre, Faculty of Clinical and Biomedical Sciences, School of Pharmacy and Biomedical Sciences, University of Central Lancashire, Preston, UK
| | - StJohn Crean
- Brain and Behaviour Centre, Faculty of Clinical and Biomedical Sciences, School of Dentistry, University of Central Lancashire, Preston, UK
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Takata F, Nakagawa S, Matsumoto J, Dohgu S. Blood-Brain Barrier Dysfunction Amplifies the Development of Neuroinflammation: Understanding of Cellular Events in Brain Microvascular Endothelial Cells for Prevention and Treatment of BBB Dysfunction. Front Cell Neurosci 2021; 15:661838. [PMID: 34588955 PMCID: PMC8475767 DOI: 10.3389/fncel.2021.661838] [Citation(s) in RCA: 156] [Impact Index Per Article: 52.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 08/09/2021] [Indexed: 12/11/2022] Open
Abstract
Neuroinflammation is involved in the onset or progression of various neurodegenerative diseases. Initiation of neuroinflammation is triggered by endogenous substances (damage-associated molecular patterns) and/or exogenous pathogens. Activation of glial cells (microglia and astrocytes) is widely recognized as a hallmark of neuroinflammation and triggers the release of proinflammatory cytokines, leading to neurotoxicity and neuronal dysfunction. Another feature associated with neuroinflammatory diseases is impairment of the blood-brain barrier (BBB). The BBB, which is composed of brain endothelial cells connected by tight junctions, maintains brain homeostasis and protects neurons. Impairment of this barrier allows trafficking of immune cells or plasma proteins into the brain parenchyma and subsequent inflammatory processes in the brain. Besides neurons, activated glial cells also affect BBB integrity. Therefore, BBB dysfunction can amplify neuroinflammation and act as a key process in the development of neuroinflammation. BBB integrity is determined by the integration of multiple signaling pathways within brain endothelial cells through intercellular communication between brain endothelial cells and brain perivascular cells (pericytes, astrocytes, microglia, and oligodendrocytes). For prevention of BBB disruption, both cellular components, such as signaling molecules in brain endothelial cells, and non-cellular components, such as inflammatory mediators released by perivascular cells, should be considered. Thus, understanding of intracellular signaling pathways that disrupt the BBB can provide novel treatments for neurological diseases associated with neuroinflammation. In this review, we discuss current knowledge regarding the underlying mechanisms involved in BBB impairment by inflammatory mediators released by perivascular cells.
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Affiliation(s)
- Fuyuko Takata
- Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
| | - Shinsuke Nakagawa
- Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
| | - Junichi Matsumoto
- Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
| | - Shinya Dohgu
- Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
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Elabi OF, Cunha JPMCM, Gaceb A, Fex M, Paul G. High-fat diet-induced diabetes leads to vascular alterations, pericyte reduction, and perivascular depletion of microglia in a 6-OHDA toxin model of Parkinson disease. J Neuroinflammation 2021; 18:175. [PMID: 34376193 PMCID: PMC8353816 DOI: 10.1186/s12974-021-02218-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 07/15/2021] [Indexed: 02/07/2023] Open
Abstract
Background Diabetes has been recognized as a risk factor contributing to the incidence and progression of Parkinson’s disease (PD). Although several hypotheses suggest a number of different mechanisms underlying the aggravation of PD caused by diabetes, less attention has been paid to the fact that diabetes and PD share pathological microvascular alterations in the brain. The characteristics of the interaction of diabetes in combination with PD at the vascular interface are currently not known. Methods We combined a high-fat diet (HFD) model of diabetes mellitus type 2 (DMT2) with the 6-OHDA lesion model of PD in male mice. We analyzed the association between insulin resistance and the achieved degree of dopaminergic nigrostriatal pathology. We further assessed the impact of the interaction of the two pathologies on motor deficits using a battery of behavioral tests and on microglial activation using immunohistochemistry. Vascular pathology was investigated histologically by analyzing vessel density and branching points, pericyte density, blood–brain barrier leakage, and the interaction between microvessels and microglia in the striatum. Results Different degrees of PD lesion were obtained resulting in moderate and severe dopaminergic cell loss. Even though the HFD paradigm did not affect the degree of nigrostriatal lesion in the acute toxin-induced PD model used, we observed a partial aggravation of the motor performance of parkinsonian mice by the diet. Importantly, the combination of a moderate PD pathology and HFD resulted in a significant pericyte depletion, an absence of an angiogenic response, and a significant reduction in microglia/vascular interaction pointing to an aggravation of vascular pathology. Conclusion This study provides the first evidence for an interaction of DMT2 and PD at the brain microvasculature involving changes in the interaction of microglia with microvessels. These pathological changes may contribute to the pathological mechanisms underlying the accelerated progression of PD when associated with diabetes. Supplementary Information The online version contains supplementary material available at 10.1186/s12974-021-02218-8.
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Affiliation(s)
- Osama F Elabi
- Translational Neurology Group, Department of Clinical Science, Wallenberg Neuroscience Center and Wallenberg Center for Molecular Medicine, Lund University, 22184, Lund, Sweden
| | - João Paulo M C M Cunha
- Unit of Molecular Metabolism, Lund University Diabetes Centre, Jan Waldenströms gata 35, Box 50332, 202 13, Malmö, Sweden
| | - Abderahim Gaceb
- Translational Neurology Group, Department of Clinical Science, Wallenberg Neuroscience Center and Wallenberg Center for Molecular Medicine, Lund University, 22184, Lund, Sweden
| | - Malin Fex
- Unit of Molecular Metabolism, Lund University Diabetes Centre, Jan Waldenströms gata 35, Box 50332, 202 13, Malmö, Sweden
| | - Gesine Paul
- Translational Neurology Group, Department of Clinical Science, Wallenberg Neuroscience Center and Wallenberg Center for Molecular Medicine, Lund University, 22184, Lund, Sweden. .,Department of Neurology, Scania University Hospital, 22185, Lund, Sweden.
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11
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Kong L, Liu Y, Zhang YM, Li Y, Gou LS, Ma TF, Liu YW. Sarsasapogenin ameliorates diabetes-associated memory impairment and neuroinflammation through down-regulation of PAR-1 receptor. Phytother Res 2021; 35:3167-3180. [PMID: 33885189 DOI: 10.1002/ptr.7005] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 12/08/2020] [Accepted: 12/15/2020] [Indexed: 12/15/2022]
Abstract
Sarsasapogenin (Sar), a natural steroidal compound, shows neuroprotection, cognition-enhancement, antiinflammation, antithrombosis effects, and so on. However, whether Sar has ameliorative effects on diabetes-associated cognitive impairment remains unknown. In this study, we found that Sar ameliorated diabetes-associated memory impairment in streptozotocin-induced diabetic rats, evidenced by increased numbers of crossing platform and percentage of time spent in the target quadrant in Morris water maze tests, and suppressed the nucleotide-binding domain and leucine-rich repeat containing protein 1 (NLRP1) inflammasome in hippocampus and cerebral cortex. Furthermore, Sar inhibited advanced glycation end-products and its receptor (AGEs/RAGE) axis and suppressed up-regulation of thrombin receptor protease-activated receptor 1 (PAR-1) in cerebral cortex. On the other hand, Sar mitigated high glucose-induced neuronal damages, NLRP1 inflammasome activation, and PAR-1 up-regulation in high glucose-cultured SH-SY5Y cells, but did not affect thrombin activity. Moreover, the effects of Sar were similar to those of a selective PAR-1 antagonist vorapaxar. Further studies indicated that activation of the NLRP1 inflammasome and NF-κB mediated the effect of PAR-1 up-regulation in high glucose condition by using PAR-1 knockdown assay. In summary, this study demonstrated that Sar prevented memory impairment caused by diabetes, which was achieved through suppressing neuroinflammation from activated NLRP1 inflammasome and NF-κB regulated by cerebral PAR-1. HIGHLIGHTS: Sarsasapogenin ameliorated memory impairment caused by diabetes in rats. Sarsasapogenin mitigated neuronal damages and neuroinflammation by down-regulating cerebral PAR-1. The NLRP1 inflammasome and NF-κB signaling mediated the pro-inflammatory effects of PAR-1. Sarsasapogenin was a pleiotropic neuroprotective agent and memory enhancer in diabetic rodents.
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Affiliation(s)
- Li Kong
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Yue Liu
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Yu-Meng Zhang
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Yu Li
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Ling-Shan Gou
- Center for Genetic Medicine, Xuzhou Maternity and Child Health Care Hospital, Xuzhou, Jiangsu, China
| | - Teng-Fei Ma
- Institute for Stem Cell and Neural Regeneration; Key Laboratory of Cardiovascular & Cerebrovascular Medicine, School of Pharmacy, Nanjing Medical University, Nanjing, China
| | - Yao-Wu Liu
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou, Jiangsu, China.,Department of Pharmacology, School of Pharmacy, Xuzhou Medical University, Xuzhou, Jiangsu, China
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12
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Jordan KR, Parra-Izquierdo I, Gruber A, Shatzel JJ, Pham P, Sherman LS, McCarty OJT, Verbout NG. Thrombin generation and activity in multiple sclerosis. Metab Brain Dis 2021; 36:407-420. [PMID: 33411219 PMCID: PMC7864536 DOI: 10.1007/s11011-020-00652-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 11/25/2020] [Indexed: 01/19/2023]
Abstract
The coagulation cascade and immune system are intricately linked, highly regulated and respond cooperatively in response to injury and infection. Increasingly, evidence of hyper-coagulation has been associated with autoimmune disorders, including multiple sclerosis (MS). The pathophysiology of MS includes immune cell activation and recruitment to the central nervous system (CNS) where they degrade myelin sheaths, leaving neuronal axons exposed to damaging inflammatory mediators. Breakdown of the blood-brain barrier (BBB) facilitates the entry of peripheral immune cells. Evidence of thrombin activity has been identified within the CNS of MS patients and studies using animal models of experimental autoimmune encephalomyelitis (EAE), suggest increased thrombin generation and activity may play a role in the pathogenesis of MS as well as inhibit remyelination processes. Thrombin is a serine protease capable of cleaving multiple substrates, including protease activated receptors (PARs), fibrinogen, and protein C. Cleavage of all three of these substrates represent pathways through which thrombin activity may exert immuno-regulatory effects and regulate permeability of the BBB during MS and EAE. In this review, we summarize evidence that thrombin activity directly, through PARs, and indirectly, through fibrin formation and activation of protein C influences neuro-immune responses associated with MS and EAE pathology.
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Affiliation(s)
- Kelley R Jordan
- Department of Biomedical Engineering, Oregon Health and Science University, School of Medicine, 3303 SW Bond Avenue, Portland, OR, 97239, USA.
| | - Ivan Parra-Izquierdo
- Department of Biomedical Engineering, Oregon Health and Science University, School of Medicine, 3303 SW Bond Avenue, Portland, OR, 97239, USA
- Division of Hematology and Medical Oncology, Oregon Health and Science University, Knight Cancer Institute, Portland, OR, USA
| | - András Gruber
- Department of Biomedical Engineering, Oregon Health and Science University, School of Medicine, 3303 SW Bond Avenue, Portland, OR, 97239, USA
- Division of Hematology and Medical Oncology, Oregon Health and Science University, Knight Cancer Institute, Portland, OR, USA
- Aronora Inc, Portland, OR, USA
| | - Joseph J Shatzel
- Department of Biomedical Engineering, Oregon Health and Science University, School of Medicine, 3303 SW Bond Avenue, Portland, OR, 97239, USA
- Division of Hematology and Medical Oncology, Oregon Health and Science University, Knight Cancer Institute, Portland, OR, USA
| | - Peter Pham
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR, USA
| | - Larry S Sherman
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR, USA
| | - Owen J T McCarty
- Department of Biomedical Engineering, Oregon Health and Science University, School of Medicine, 3303 SW Bond Avenue, Portland, OR, 97239, USA
- Division of Hematology and Medical Oncology, Oregon Health and Science University, Knight Cancer Institute, Portland, OR, USA
| | - Norah G Verbout
- Department of Biomedical Engineering, Oregon Health and Science University, School of Medicine, 3303 SW Bond Avenue, Portland, OR, 97239, USA
- Aronora Inc, Portland, OR, USA
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13
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Watt C, Sanchez-Rangel E, Hwang JJ. Glycemic Variability and CNS Inflammation: Reviewing the Connection. Nutrients 2020; 12:nu12123906. [PMID: 33371247 PMCID: PMC7766608 DOI: 10.3390/nu12123906] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 12/11/2020] [Accepted: 12/14/2020] [Indexed: 12/16/2022] Open
Abstract
Glucose is the primary energy source for the brain, and exposure to both high and low levels of glucose has been associated with numerous adverse central nervous system (CNS) outcomes. While a large body of work has highlighted the impact of hyperglycemia on peripheral and central measures of oxidative stress, cognitive deficits, and vascular complications in Type 1 and Type 2 diabetes, there is growing evidence that glycemic variability significantly drives increased oxidative stress, leading to neuroinflammation and cognitive dysfunction. In this review, the latest data on the impact of glycemic variability on brain function and neuroinflammation will be presented. Because high levels of oxidative stress have been linked to dysfunction of the blood-brain barrier (BBB), special emphasis will be placed on studies investigating the impact of glycemic variability on endothelial and vascular inflammation. The latest clinical and preclinical/in vitro data will be reviewed, and clinical/therapeutic implications will be discussed.
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14
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Matsumoto J, Dohgu S, Takata F, Iwao T, Kimura I, Tomohiro M, Aono K, Kataoka Y, Yamauchi A. Serum amyloid A-induced blood-brain barrier dysfunction associated with decreased claudin-5 expression in rat brain endothelial cells and its inhibition by high-density lipoprotein in vitro. Neurosci Lett 2020; 738:135352. [PMID: 32931862 DOI: 10.1016/j.neulet.2020.135352] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 07/30/2020] [Accepted: 09/01/2020] [Indexed: 12/16/2022]
Abstract
The blood-brain barrier (BBB) is the multicellular interface located between the peripheral circulation and the brain parenchyma. BBB dysfunction is reported in many CNS diseases, such cognitive impairment, depression, Alzheimer's disease (AD), and multiple sclerosis (MS). Emerging evidence indicates that liver-derived inflammatory mediators are upregulated in neurological diseases with BBB dysfunction. Serum amyloid A (SAA), an acute phase protein secreted by hepatocytes, could be a candidate inflammatory signaling molecule transmitted from the liver to the brain; however, its contribution to BBB dysfunction is poorly understood. The present study aimed to elucidate the involvement of SAA in BBB impairment in an in vitro BBB model using rat brain microvascular endothelial cells (RBECs). We demonstrated that Apo-SAA significantly decreased transendothelial electrical resistance (TEER) and increased sodium fluorescein (Na-F) permeability in RBEC monolayers. Apo-SAA also decreased claudin-5 expression levels in RBECs. Furthermore, the Apo-SAA-mediated impairment of the BBB with decreased claudin-5 expression was inhibited by the addition of a high-density lipoprotein (HDL) related to SAA in plasma. These findings suggest that HDL counteracts the effects of SAA on BBB function. Therefore, the functional imbalance between SAA and HDL may induce BBB impairment, thereby triggering development of neuroinflammation. SAA could be a significant endogenous mediator in the liver-to-brain inflammation axis.
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Affiliation(s)
- Junichi Matsumoto
- Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan.
| | - Shinya Dohgu
- Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan.
| | - Fuyuko Takata
- Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan.
| | - Takuro Iwao
- Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan.
| | - Ikuya Kimura
- Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan.
| | - Misaki Tomohiro
- Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan.
| | - Kentaro Aono
- Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan.
| | - Yasufumi Kataoka
- Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan.
| | - Atsushi Yamauchi
- Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan.
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15
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Dysfunction of the neurovascular unit in diabetes-related neurodegeneration. Biomed Pharmacother 2020; 131:110656. [PMID: 32841897 DOI: 10.1016/j.biopha.2020.110656] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 08/10/2020] [Accepted: 08/17/2020] [Indexed: 12/13/2022] Open
Abstract
In current aging societies, diabetes mellitus and neurodegenerative diseases represented by Alzheimer's disease are highly prevalent among adults, especially the elderly all over the world. It is worth noting that a substantial body of evidence suggests diabetes contributes to accelerated neurodegenerative processes and the decline of cognition. Over the last few years, some studies have indicated neurovascular uncoupling and disrupted functional connectivity in the early stages of many neurodegenerative diseases, and the concept of the neurovascular unit (NVU) has been highlighted to understand the initiation and progression of neurodegenerative diseases recently. Considering that some components of the NVU are also demonstrated to have abnormal morphology and function under the condition of diabetes, we propose the hypothesis that diabetes may promote the onset and development of neurodegenerative diseases by impairing the integrity of the NVU, named Diabetes-NVU-Neurodegeneration Hypothesis. The existing body of literature supporting the hypothesis and elucidating the underlying mechanisms will be summarized in this review.
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16
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Iannucci J, Renehan W, Grammas P. Thrombin, a Mediator of Coagulation, Inflammation, and Neurotoxicity at the Neurovascular Interface: Implications for Alzheimer's Disease. Front Neurosci 2020; 14:762. [PMID: 32792902 PMCID: PMC7393221 DOI: 10.3389/fnins.2020.00762] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 06/29/2020] [Indexed: 12/11/2022] Open
Abstract
The societal burden of Alzheimer’s disease (AD) is staggering, with current estimates suggesting that 50 million people world-wide have AD. Identification of new therapeutic targets is a critical barrier to the development of disease-modifying therapies. A large body of data implicates vascular pathology and cardiovascular risk factors in the development of AD, indicating that there are likely shared pathological mediators. Inflammation plays a role in both cardiovascular disease and AD, and recent evidence has implicated elements of the coagulation system in the regulation of inflammation. In particular, the multifunctional serine protease thrombin has been found to act as a mediator of vascular dysfunction and inflammation in both the periphery and the central nervous system. In the periphery, thrombin contributes to the development of cardiovascular disease, including atherosclerosis and diabetes, by inducing endothelial dysfunction and related inflammation. In the brain, thrombin has been found to act on endothelial cells of the blood brain barrier, microglia, astrocytes, and neurons in a manner that promotes vascular dysfunction, inflammation, and neurodegeneration. Thrombin is elevated in the AD brain, and thrombin signaling has been linked to both tau and amyloid beta, pathological hallmarks of the disease. In AD mouse models, inhibiting thrombin preserves cognition and endothelial function and reduces neuroinflammation. Evidence linking atrial fibrillation with AD and dementia indicates that anticoagulant therapy may reduce the risk of dementia, with targeting thrombin shown to be particularly effective. It is time for “outside-the-box” thinking about how vascular risk factors, such as atherosclerosis and diabetes, as well as the coagulation and inflammatory pathways interact to promote increased AD risk. In this review, we present evidence that thrombin is a convergence point for AD risk factors and as such that thrombin-based therapeutics could target multiple points of AD pathology, including neurodegeneration, vascular activation, and neuroinflammation. The urgent need for disease-modifying drugs in AD demands new thinking about disease pathogenesis and an exploration of novel drug targets, we propose that thrombin inhibition is an innovative tactic in the therapeutic battle against this devastating disease.
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Affiliation(s)
- Jaclyn Iannucci
- The George and Anne Ryan Institute for Neuroscience, The University of Rhode Island, Kingston, RI, United States.,Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, The University of Rhode Island, Kingston, RI, United States
| | - William Renehan
- The George and Anne Ryan Institute for Neuroscience, The University of Rhode Island, Kingston, RI, United States
| | - Paula Grammas
- The George and Anne Ryan Institute for Neuroscience, The University of Rhode Island, Kingston, RI, United States.,Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, The University of Rhode Island, Kingston, RI, United States
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17
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Ghali MGZ, Marchenko V, Yaşargil MG, Ghali GZ. Structure and function of the perivascular fluid compartment and vertebral venous plexus: Illumining a novel theory on mechanisms underlying the pathogenesis of Alzheimer's, cerebral small vessel, and neurodegenerative diseases. Neurobiol Dis 2020; 144:105022. [PMID: 32687942 DOI: 10.1016/j.nbd.2020.105022] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 06/13/2020] [Accepted: 07/15/2020] [Indexed: 01/14/2023] Open
Abstract
Blood dynamically and richly supplies the cerebral tissue via microvessels invested in pia matter perforating the cerebral substance. Arteries penetrating the cerebral substance derive an investment from one or two successive layers of pia mater, luminally apposed to the pial-glial basal lamina of the microvasculature and abluminally apposed to a series of aquaporin IV-studded astrocytic end feet constituting the soi-disant glia limitans. The full investment of successive layers forms the variably continuous walls of the periarteriolar, pericapillary, and perivenular divisions of the perivascular fluid compartment. The pia matter disappears at the distal periarteriolar division of the perivascular fluid compartment. Plasma from arteriolar blood sequentially transudates into the periarteriolar division of the perivascular fluid compartment and subarachnoid cisterns in precession to trickling into the neural interstitium. Fluid from the neural interstitium successively propagates into the venules through the subarachnoid cisterns and perivenular division of the perivascular fluid compartment. Fluid fluent within the perivascular fluid compartment flows gegen the net direction of arteriovenular flow. Microvessel oscillations at the central tendency of the cerebral vasomotion generate corresponding oscillations of within the surrounding perivascular fluid compartment, interposed betwixt the abluminal surface of the vessels and internal surface of the pia mater. The precise microanatomy of this most fascinating among designable spaces has eluded the efforts of various investigators to interrogate its structure, though most authors non-consensusly concur the investing layers effectively and functionally segregate the perivascular and subarachnoid fluid compartments. Enlargement of the perivascular fluid compartment in a variety of neurological disorders, including senile dementia of the Alzheimer's type and cerebral small vessel disease, may alternately or coordinately constitute a correlative marker of disease severity and a possible cause implicated in the mechanistic pathogenesis of these conditions. Venular pressures modulating oscillatory dynamic flow within the perivascular fluid compartment may similarly contribute to the development of a variety among neurological disorders. An intimate understanding of subtle features typifying microanatomy and microphysiology of the investing structures and spaces of the cerebral microvasculature may powerfully inform mechanistic pathophysiology mediating a variety of neurovascular ischemic, neuroinfectious, neuroautoimmune, and neurodegenerative diseases.
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Affiliation(s)
- Michael George Zaki Ghali
- Department of Neurological Surgery, University of California San Francisco, 505 Parnassus Street, San Francisco, CA 94143, United States; Department of Neurobiology and Anatomy, 2900 W. Queen Lane, Philadelphia, PA 19129, United States.
| | - Vitaliy Marchenko
- Department of Neurobiology and Anatomy, 2900 W. Queen Lane, Philadelphia, PA 19129, United States; Department of Neurophysiology, Bogomoletz Institute, Kyiv, Ukraine; Department of Neuroscience, Московский государственный университет имени М. В., Ломоносова GSP-1, Leninskie Gory, Moscow 119991, Russian Federation
| | - M Gazi Yaşargil
- Department of Neurosurgery, University Hospital Zurich Rämistrasse 100, 8091 Zurich, Switzerland
| | - George Zaki Ghali
- United States Environmental Protection Agency, Arlington, Virginia, USA; Emeritus Professor of Toxicology, Purdue University, West Lafayette, Indiana, USA
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18
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Andjelkovic AV, Stamatovic SM, Phillips CM, Martinez-Revollar G, Keep RF. Modeling blood-brain barrier pathology in cerebrovascular disease in vitro: current and future paradigms. Fluids Barriers CNS 2020; 17:44. [PMID: 32677965 PMCID: PMC7367394 DOI: 10.1186/s12987-020-00202-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 06/15/2020] [Indexed: 12/16/2022] Open
Abstract
The complexity of the blood–brain barrier (BBB) and neurovascular unit (NVU) was and still is a challenge to bridge. A highly selective, restrictive and dynamic barrier, formed at the interface of blood and brain, the BBB is a “gatekeeper” and guardian of brain homeostasis and it also acts as a “sensor” of pathological events in blood and brain. The majority of brain and cerebrovascular pathologies are associated with BBB dysfunction, where changes at the BBB can lead to or support disease development. Thus, an ultimate goal of BBB research is to develop competent and highly translational models to understand mechanisms of BBB/NVU pathology and enable discovery and development of therapeutic strategies to improve vascular health and for the efficient delivery of drugs. This review article focuses on the progress being made to model BBB injury in cerebrovascular diseases in vitro.
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Affiliation(s)
- Anuska V Andjelkovic
- Department of Pathology, University of Michigan Medical School, 7520 MSRB I, 1150 West Medical Center Dr, Ann Arbor, MI, 48109-5602, USA.
| | - Svetlana M Stamatovic
- Department of Pathology, University of Michigan Medical School, 7520 MSRB I, 1150 West Medical Center Dr, Ann Arbor, MI, 48109-5602, USA
| | - Chelsea M Phillips
- Graduate Program in Neuroscience, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Gabriela Martinez-Revollar
- Department of Pathology, University of Michigan Medical School, 7520 MSRB I, 1150 West Medical Center Dr, Ann Arbor, MI, 48109-5602, USA
| | - Richard F Keep
- Department of Neurosurgery, University of Michigan Medical School, Ann Arbor, MI, USA.,Department of Molecular Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA
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19
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Banks WA. The Blood-Brain Barrier Interface in Diabetes Mellitus: Dysfunctions, Mechanisms and Approaches to Treatment. Curr Pharm Des 2020; 26:1438-1447. [DOI: 10.2174/1381612826666200325110014] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 02/27/2020] [Indexed: 12/24/2022]
Abstract
Diabetes mellitus (DM) is one of the most common diseases in the world. Among its effects are an increase in the risk of cognitive impairment, including Alzheimer’s disease, and blood-brain barrier (BBB) dysfunction. DM is characterized by high blood glucose levels that are caused by either lack of insulin (Type I) or resistance to the actions of insulin (Type II). The phenotypes of these two types are dramatically different, with Type I animals being thin, with low levels of leptin as well as insulin, whereas Type II animals are often obese with high levels of both leptin and insulin. The best characterized change in BBB dysfunction is that of disruption. The brain regions that are disrupted, however, vary between Type I vs Type II DM, suggesting that factors other than hyperglycemia, perhaps hormonal factors such as leptin and insulin, play a regionally diverse role in BBB vulnerability or protection. Some BBB transporters are also altered in DM, including P-glycoprotein, lowdensity lipoprotein receptor-related protein 1, and the insulin transporter as other functions of the BBB, such as brain endothelial cell (BEC) expression of matrix metalloproteinases (MMPs) and immune cell trafficking. Pericyte loss secondary to the increased oxidative stress of processing excess glucose through the Krebs cycle is one mechanism that has shown to result in BBB disruption. Vascular endothelial growth factor (VEGF) induced by advanced glycation endproducts can increase the production of matrix metalloproteinases, which in turn affects tight junction proteins, providing another mechanism for BBB disruption as well as effects on P-glycoprotein. Through the enhanced expression of the redox-related mitochondrial transporter ABCB10, redox-sensitive transcription factor NF-E2 related factor-2 (Nrf2) inhibits BEC-monocyte adhesion. Several potential therapies, in addition to those of restoring euglycemia, can prevent some aspects of BBB dysfunction. Carbonic anhydrase inhibition decreases glucose metabolism and so reduces oxidative stress, preserving pericytes and blocking or reversing BBB disruption. Statins or N-acetylcysteine can reverse the BBB opening in some models of DM, fibroblast growth factor-21 improves BBB permeability through an Nrf2-dependent pathway, and nifedipine or VEGF improves memory in DM models. In summary, DM alters various aspects of BBB function through a number of mechanisms. A variety of treatments based on those mechanisms, as well as restoration of euglycemia, may be able to restore BBB functions., including reversal of BBB disruption.
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Affiliation(s)
- William A. Banks
- Geriatric Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, United States
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20
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BenAri O, Efrati S, Sano M, Bendlin BB, Lin H, Liu X, Sela I, Almog G, Livny A, Sandler I, Ben‐Haim S, Sagi R, LeRoith D, Schnaider Beeri M, Ravona‐Springer R. A double-blind placebo-controlled clinical trial testing the effect of hyperbaric oxygen therapy on brain and cognitive outcomes of mildly cognitively impaired elderly with type 2 diabetes: Study design. ALZHEIMER'S & DEMENTIA (NEW YORK, N. Y.) 2020; 6:e12008. [PMID: 32296731 PMCID: PMC7153432 DOI: 10.1002/trc2.12008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 12/26/2019] [Indexed: 12/30/2022]
Abstract
INTRODUCTION Type 2 diabetes (T2D) is a risk factor for dementia. Ischemia due to vascular pathology is hypothesized to be an underlying mechanism for this association. Hyperbaric oxygen therapy (HBOT) is a treatment in which oxygen-enriched air (up to 100%) is administered to patients in a chamber at a pressure above one atmosphere absolute. HBOT is approved for the treatment of T2D ischemic non-healing wounds. Evidence from animal studies and small clinical trials suggests that HBOT improves hypoxic/ischemic brain injuries, consequently inducing brain angiogensis, leading to cognitive improvement. METHODS We present the design of the first double-blind, placebo-controlled, clinical trial on brain and cognitive outcomes in elderly (n = 154) with T2D and mild cognitive impairment to compare the effects of HBOT versus sham (normal air with 1.1 ATA pressure in the first and last 5 minutes of the session). Eligible candidates are randomized with equal probability to HBOT and sham. Outcomes are assessed before and after treatment, and at 6- and 12-month follow-up. The primary cognitive outcome is global cognitive change, indexed by a composite sum of z-scores of four executive functions and four episodic memory tests. The primary neurobiological outcome is cerebral blood flow (CBF; via arterial spin labeling magnetic resonance imaging [ASL-MRI]) and cerebral glucose utilization via fluorodeoxyglucose positron emission tomography (FDG-PET). Secondary outcome measures are specific cognitive domains (executive function and episodic memory) and functional measures (Clinical Dementia Rating sum of boxes, activities of daily living). Efficacy analyses will be performed for the intent-to-treat sample. DISCUSSION Recent studies suggest that HBOT induces neuroplasticity and improves cognition in post-stroke and traumatic brain injury patients. However, its effect on cognition, cerebral blood flow, and brain glucose utilization in T2D patients at high dementia risk is yet to be determined. If effective, this study may provide strong evidence for the brain and cognitive benefits of HBOT in this population.
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Affiliation(s)
- Ori BenAri
- The Joseph Sagol Neuroscience CenterSheba Medical CenterTel‐HashomerRamat‐GanIsrael
- Sackler Faculty of MedicineTel Aviv UniversityTel AvivIsrael
| | - Shai Efrati
- Sackler Faculty of MedicineTel Aviv UniversityTel AvivIsrael
- Sagol center for Hyperbaric Medicine & ResearchShamir (Assaf Harofeh) Medical CenterBe'er Ya'akovIsrael
| | - Mary Sano
- Department of PsychiatryIcahn School of Medicine at Mount SinaiNew YorkNew YorkUSA
| | - Barbara B. Bendlin
- Wisconsin Alzheimer's Disease Research CenterUniversity of Wisconsin‐Madison School of Medicine and Public HealthMadisonWisconsinUSA
| | - HungMo Lin
- Department of PsychiatryIcahn School of Medicine at Mount SinaiNew YorkNew YorkUSA
| | - Xiaoyu Liu
- Department of PsychiatryIcahn School of Medicine at Mount SinaiNew YorkNew YorkUSA
| | - Inbar Sela
- The Joseph Sagol Neuroscience CenterSheba Medical CenterTel‐HashomerRamat‐GanIsrael
| | - Ganit Almog
- The Joseph Sagol Neuroscience CenterSheba Medical CenterTel‐HashomerRamat‐GanIsrael
| | - Abigail Livny
- The Joseph Sagol Neuroscience CenterSheba Medical CenterTel‐HashomerRamat‐GanIsrael
- Sackler Faculty of MedicineTel Aviv UniversityTel AvivIsrael
- Division of Diagnostic ImagingSheba Medical CenterTel‐HashomerRamat‐GanIsrael
| | - Israel Sandler
- Department of Nuclear MedicineSheba Medical CenterTel‐HashomerRamat‐GanIsrael
| | - Simona Ben‐Haim
- Department of Biophysics and Nuclear MedicineHadassah University HospitalEin KeremJerusalemIsrael
- Institute of Nuclear MedicineUniversity College London HospitalsNHS TrustLondonUK
| | - Roy Sagi
- Sagol center for Hyperbaric Medicine & ResearchShamir (Assaf Harofeh) Medical CenterBe'er Ya'akovIsrael
| | - Derek LeRoith
- Department of PsychiatryIcahn School of Medicine at Mount SinaiNew YorkNew YorkUSA
| | - Michal Schnaider Beeri
- The Joseph Sagol Neuroscience CenterSheba Medical CenterTel‐HashomerRamat‐GanIsrael
- Department of PsychiatryIcahn School of Medicine at Mount SinaiNew YorkNew YorkUSA
| | - Ramit Ravona‐Springer
- The Joseph Sagol Neuroscience CenterSheba Medical CenterTel‐HashomerRamat‐GanIsrael
- Sackler Faculty of MedicineTel Aviv UniversityTel AvivIsrael
- Department of PsychiatrySheba Medical CenterTel‐HashomerRamat‐GanIsrael
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Buie JJ, Watson LS, Smith CJ, Sims-Robinson C. Obesity-related cognitive impairment: The role of endothelial dysfunction. Neurobiol Dis 2019; 132:104580. [PMID: 31454547 PMCID: PMC6834913 DOI: 10.1016/j.nbd.2019.104580] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Revised: 07/27/2019] [Accepted: 08/20/2019] [Indexed: 12/16/2022] Open
Abstract
Obesity is a global pandemic associated with macro- and microvascular endothelial dysfunction. Microvascular endothelial dysfunction has recently emerged as a significant risk factor for the development of cognitive impairment. In this review, we present evidence from clinical and preclinical studies supporting a role for obesity in cognitive impairment. Next, we discuss how obesity-related hyperinsulinemia/insulin resistance, systemic inflammation, and gut dysbiosis lead to cognitive impairment through induction of endothelial dysfunction and disruption of the blood brain barrier. Finally, we outline the potential clinical utility of dietary interventions, exercise, and bariatric surgery in circumventing the impacts of obesity on cognitive function.
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Affiliation(s)
- Joy Jones Buie
- WISSDOM Center, Medical University of South Carolina, Charleston, SC 29425, USA; Department of Neurology, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Luke S Watson
- Department of Neurology, Medical University of South Carolina, Charleston, SC 29425, USA; Molecular and Cellular Biology and Pathobiology Program, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Crystal J Smith
- Department of Neurology, Medical University of South Carolina, Charleston, SC 29425, USA; Department of Neurosciences, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Catrina Sims-Robinson
- Department of Neurology, Medical University of South Carolina, Charleston, SC 29425, USA; Molecular and Cellular Biology and Pathobiology Program, Medical University of South Carolina, Charleston, SC 29425, USA; Department of Neurosciences, Medical University of South Carolina, Charleston, SC 29425, USA.
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22
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Takata F, Dohgu S, Sakaguchi S, Sakai K, Yamanaka G, Iwao T, Matsumoto J, Kimura I, Sezaki Y, Tanaka Y, Yamauchi A, Kataoka Y. Oncostatin-M-Reactive Pericytes Aggravate Blood-Brain Barrier Dysfunction by Activating JAK/STAT3 Signaling In Vitro. Neuroscience 2019; 422:12-20. [PMID: 31705893 DOI: 10.1016/j.neuroscience.2019.10.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 09/05/2019] [Accepted: 10/01/2019] [Indexed: 02/05/2023]
Abstract
Oncostatin M (OSM) is a cytokine of the interleukin (IL)-6 family members. It induces blood-brain barrier (BBB) dysfunction by activating Janus-activated kinase (JAK) and signal transducer and activator of transcription (STAT) 3 pathways in brain endothelial cells. Brain pericytes located around microvessels are one of the BBB constituents. Pericytes work as a boundary surface between the blood circulation and brain parenchyma, and their functions are altered under pathophysiological conditions, leading to BBB dysregulation. However, it remains unknown whether pericytes are associated with OSM-induced BBB dysfunction. We demonstrated that pericyte exposure to OSM (100 ng/mL) elevated phosphorylation of STAT3, a main OSM signaling pathway, and that pericytes expressed OSM receptors (OSMRs) including OSMRβ and glycoprotein 130. These results suggest that pericytes are able to respond to OSM. To determine the effects of OSM-reactive pericytes on BBB functions, rat brain endothelial cell (RBEC) monolayers were cultured with OSM-treated pericytes. The presence of pericytes exposed to 100 ng/mL of OSM for 48 h aggravated both the elevated permeability to sodium fluorescein and the lowered transendothelial electrical resistance which were induced by OSM in RBECs. This OSM-reactive pericyte-induced aggravation of lowered RBEC barrier function was reversed by ruxolitinib, a JAK inhibitor. These findings suggest that activated JAK/STAT3 signaling in pericytes contributes to OSM-produced BBB breakdown. Thus, OSM-reactive pericytes may have to be considered a characteristic machinery in the formation and progression of BBB breakdown under pathological conditions associated with increased OSM levels.
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Affiliation(s)
- Fuyuko Takata
- Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka 814-0180, Japan
| | - Shinya Dohgu
- Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka 814-0180, Japan
| | - Shinya Sakaguchi
- Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka 814-0180, Japan
| | - Kenta Sakai
- Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka 814-0180, Japan
| | - Gaku Yamanaka
- Department of Pediatrics, Tokyo Medical University, Shinjuku-ku, Tokyo 160-0023, Japan
| | - Takuro Iwao
- Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka 814-0180, Japan
| | - Junichi Matsumoto
- Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka 814-0180, Japan
| | - Ikuya Kimura
- Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka 814-0180, Japan
| | - Yume Sezaki
- Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka 814-0180, Japan
| | - Yoshie Tanaka
- Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka 814-0180, Japan
| | - Atsushi Yamauchi
- Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka 814-0180, Japan
| | - Yasufumi Kataoka
- Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka 814-0180, Japan.
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23
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Puech C, Delavenne X, He Z, Forest V, Mismetti P, Perek N. Direct oral anticoagulants are associated with limited damage of endothelial cells of the blood-brain barrier mediated by the thrombin/PAR-1 pathway. Brain Res 2019; 1719:57-63. [DOI: 10.1016/j.brainres.2019.05.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 04/26/2019] [Accepted: 05/19/2019] [Indexed: 12/01/2022]
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Geranmayeh MH, Rahbarghazi R, Farhoudi M. Targeting pericytes for neurovascular regeneration. Cell Commun Signal 2019; 17:26. [PMID: 30894190 PMCID: PMC6425710 DOI: 10.1186/s12964-019-0340-8] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Accepted: 03/13/2019] [Indexed: 02/06/2023] Open
Abstract
Pericytes, as a key cellular part of the blood-brain barrier, play an important role in the maintenance of brain neurovascular unit. These cells participate in brain homeostasis by regulating vascular development and integrity mainly through secreting various factors. Pericytes per se show different restorative properties after blood-brain barrier injury. Upon the occurrence of brain acute and chronic diseases, pericytes provoke immune cells to regulate neuro-inflammatory conditions. Loss of pericytes in distinct neurologic disorders intensifies blood-brain barrier permeability and leads to vascular dementia. The therapeutic potential of pericytes is originated from the unique morphological shape, location, and their ability in providing vast paracrine and juxtacrine interactions. A subset of pericytes possesses multipotentiality and exhibit trans-differentiation capacity in the context of damaged tissue. This review article aimed to highlight the critical role of pericytes in restoration of the blood-brain barrier after injury by focusing on the dynamics of pericytes and cross-talk with other cell types.
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Affiliation(s)
- Mohammad Hossein Geranmayeh
- Research Center for Pharmaceutical Nanotechnology, Biomedicine Institute, Tabriz University of Medical Sciences, Tabriz, Iran.,Neurosciences Research Center (NSRC), Imam Reza Medical Center, Tabriz University of Medical Sciences, Golgasht St., Azadi Ave, Tabriz, 5166614756, Iran
| | - Reza Rahbarghazi
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran. .,Department of Applied Cell Sciences, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran.
| | - Mehdi Farhoudi
- Neurosciences Research Center (NSRC), Imam Reza Medical Center, Tabriz University of Medical Sciences, Golgasht St., Azadi Ave, Tabriz, 5166614756, Iran.
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25
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Monomeric α-synuclein induces blood-brain barrier dysfunction through activated brain pericytes releasing inflammatory mediators in vitro. Microvasc Res 2019; 124:61-66. [PMID: 30885616 DOI: 10.1016/j.mvr.2019.03.005] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 01/24/2019] [Accepted: 03/13/2019] [Indexed: 01/08/2023]
Abstract
Blood-brain barrier (BBB) disruption is often mediated by neuroinflammation, and occurs during various neurodegenerative diseases including Parkinson's disease (PD). PD is characterized by loss of dopaminergic neurons and aggregated α-synuclein protein in inclusions known as Lewy bodies. Misfolded α-synuclein has been implicated in neurodegeneration and neuroinflammation through activation of microglia and astrocytes. Pericytes are a key cellular regulator of the BBB, although it is not known if they participate in α-synuclein-associated PD pathology. Here, we investigated the impact of pericytes on BBB integrity in response to α-synuclein using rat brain endothelial cells (RBECs) co-cultured with rat brain pericytes (RBEC/pericyte co-culture). In RBEC/pericyte co-cultures, α-synuclein added to the abluminal chamber (where pericytes were grown) significantly increased RBEC permeability to sodium fluorescein. In contrast, it had no marked effect when added to the luminal chamber. In the absence of pericytes, both luminal and abluminal addition of α-synuclein failed to affect permeability of the RBEC monolayer. α-Synuclein did not self-assemble in culture media within 24 h, suggesting that monomeric α-synuclein can disrupt the BBB by interacting with pericytes. We found that in response to α-synuclein, pericytes, but not RBECs, released interleukin (IL)-1β, IL-6, monocyte chemotactic protein (MCP)-1, tumor necrosis factor (TNF)-α, and matrix metalloproteinase-9 (MMP-9). α-Synuclein did not affect platelet-derived growth factor (PDGF)-BB release from RBECs and PDGF receptor-β expression in pericytes. These results suggest that pericytes are more sensitive to monomeric α-synuclein than RBECs regarding release of various inflammatory cytokines/chemokines and MMP-9. Thus, monomeric α-synuclein-activated pericytes may contribute to BBB breakdown in patients with PD.
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Keep RF, Andjelkovic AV, Xiang J, Stamatovic SM, Antonetti DA, Hua Y, Xi G. Brain endothelial cell junctions after cerebral hemorrhage: Changes, mechanisms and therapeutic targets. J Cereb Blood Flow Metab 2018; 38:1255-1275. [PMID: 29737222 PMCID: PMC6092767 DOI: 10.1177/0271678x18774666] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 04/09/2018] [Indexed: 11/15/2022]
Abstract
Vascular disruption is the underlying cause of cerebral hemorrhage, including intracerebral, subarachnoid and intraventricular hemorrhage. The disease etiology also involves cerebral hemorrhage-induced blood-brain barrier (BBB) disruption, which contributes an important component to brain injury after the initial cerebral hemorrhage. BBB loss drives vasogenic edema, allows leukocyte extravasation and may lead to the entry of potentially neurotoxic and vasoactive compounds into brain. This review summarizes current information on changes in brain endothelial junction proteins in response to cerebral hemorrhage (and clot-related factors), the mechanisms underlying junction modification and potential therapeutic targets to limit BBB disruption and, potentially, hemorrhage occurrence. It also addresses advances in the tools that are now available for assessing changes in junctions after cerebral hemorrhage and the potential importance of such junction changes. Recent studies suggest post-translational modification, conformational change and intracellular trafficking of junctional proteins may alter barrier properties. Understanding how cerebral hemorrhage alters BBB properties beyond changes in tight junction protein loss may provide important therapeutic insights to prevent BBB dysfunction and restore normal function.
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Affiliation(s)
- Richard F Keep
- Department of Neurosurgery, University of Michigan Ann Arbor, MI, USA
- Department of Molecular and Integrative Physiology, University of Michigan Ann Arbor, MI, USA
| | - Anuska V Andjelkovic
- Department of Neurosurgery, University of Michigan Ann Arbor, MI, USA
- Department of Pathology, University of Michigan Ann Arbor, MI, USA
| | - Jianming Xiang
- Department of Neurosurgery, University of Michigan Ann Arbor, MI, USA
| | | | - David A Antonetti
- Department of Molecular and Integrative Physiology, University of Michigan Ann Arbor, MI, USA
- Department of Ophthalmology & Visual Science Medical School, University of Michigan Ann Arbor, MI, USA
| | - Ya Hua
- Department of Neurosurgery, University of Michigan Ann Arbor, MI, USA
| | - Guohua Xi
- Department of Neurosurgery, University of Michigan Ann Arbor, MI, USA
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