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Zhang Y, Mu BR, Ran Z, Zhu T, Huang X, Yang X, Wang DM, Ma QH, Lu MH. Pericytes in Alzheimer's disease: Key players and therapeutic targets. Exp Neurol 2024; 379:114825. [PMID: 38777251 DOI: 10.1016/j.expneurol.2024.114825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 05/09/2024] [Accepted: 05/19/2024] [Indexed: 05/25/2024]
Abstract
Alzheimer's disease (AD) is a devastating neurodegenerative disorder that leads to progressive cognitive decline and neuropathological changes. Pericytes, which are vessel mural cells on the basement membrane of capillaries, play a crucial role in regulating cerebrovascular functions and maintaining neurovascular unit integrity. Emerging research substantiates the involvement of pericytes in AD. This review provides a comprehensive overview of pericytes, including their structure, origin, and markers and various functions within the central nervous system. Emphatically, the review explores the intricate mechanisms through which pericytes contribute to AD, including their interactions with amyloid beta and apolipoprotein E, as well as various signaling pathways. The review also highlights potential for targeted pericyte therapy for AD, with a focus on stem cell therapy and drug treatments. Future research directions include the classification of pericyte subtypes, studies related to aging, and the role of pericytes in exosome-related mechanisms in AD pathology. In conclusion, this review consolidates current knowledge on the pivotal roles of pericytes in AD and their potential as therapeutic targets, providing valuable insights for future research and clinical interventions aimed at addressing the impact of AD on patients' lives.
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Affiliation(s)
- Yu Zhang
- Chongqing Key Laboratory of Sichuan-Chongqing Co-construction for Diagnosis and Treatment of Infectious Diseases Integrated Traditional Chinese and Western Medicine, College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
| | - Ben-Rong Mu
- Chongqing Key Laboratory of Sichuan-Chongqing Co-construction for Diagnosis and Treatment of Infectious Diseases Integrated Traditional Chinese and Western Medicine, College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
| | - Zhao Ran
- Chongqing Key Laboratory of Sichuan-Chongqing Co-construction for Diagnosis and Treatment of Infectious Diseases Integrated Traditional Chinese and Western Medicine, College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
| | - Tao Zhu
- Chongqing Key Laboratory of Sichuan-Chongqing Co-construction for Diagnosis and Treatment of Infectious Diseases Integrated Traditional Chinese and Western Medicine, College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
| | - Xin Huang
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, Institute of Neuroscience, Soochow University, Suzhou 215021, China
| | - Xiong Yang
- Chongqing Key Laboratory of Sichuan-Chongqing Co-construction for Diagnosis and Treatment of Infectious Diseases Integrated Traditional Chinese and Western Medicine, College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
| | - Dong-Mei Wang
- College of Basic Medical Sciences, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
| | - Quan-Hong Ma
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, Institute of Neuroscience, Soochow University, Suzhou 215021, China.
| | - Mei-Hong Lu
- Chongqing Key Laboratory of Sichuan-Chongqing Co-construction for Diagnosis and Treatment of Infectious Diseases Integrated Traditional Chinese and Western Medicine, College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China.
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Li P, Bi X, Xu D, Meng Y, Xia Y, Cai J, Shen Y, Wang J, Chen J, Yin L, Wang B, Wu D, Li K. Activation of the hypoxia response in the aging cerebrovasculature protects males against cognitive impairment. Aging Cell 2024:e14264. [PMID: 38953594 DOI: 10.1111/acel.14264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 05/28/2024] [Accepted: 06/21/2024] [Indexed: 07/04/2024] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder with a distinct sex bias. Age-related vascular alterations, a hallmark of AD onset and progression, are consistently associated with sexual dimorphism. Here, we conducted an integrative meta-analysis of 335,803 single-nucleus transcriptomes and 667 bulk transcriptomes from the vascular system in AD and normal aging to address the underlying sex-dependent vascular aging in AD. All vascular cell types in male AD patients exhibited an activated hypoxia response and downstream signaling pathways including angiogenesis. The female AD vasculature is characterized by increased antigen presentation and decreased angiogenesis. We further confirmed that these sex-biased alterations in the cerebral vascular emerged and were primarily determined in the early stages of AD. Sex-stratified analysis of normal vascular aging revealed that angiogenesis and various stress-response genes were downregulated concurrently with female aging. Conversely, the hypoxia response increased steadily in males upon aging. An investigation of upstream driver transcription factors (TFs) revealed that altered communication between estrogen receptor alpha (ESR1) and hypoxia induced factors during menopause contributes to the inhibition of angiogenesis during normal female vascular aging. Additionally, inhibition of CREB1, a TF that targets estrogen, is also related to female AD. Overall, our study revealed a distinct cerebral vascular profile in females and males, and revealed novel targets for precision medicine therapy for AD.
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Affiliation(s)
- Peihu Li
- College of Biomedical Information and Engineering, Hainan General Hospital, Hainan Affiliated Hospital of Hainan Medical University, Haikou, China
| | - Xiaoman Bi
- College of Biomedical Information and Engineering, Hainan General Hospital, Hainan Affiliated Hospital of Hainan Medical University, Haikou, China
| | - Dahua Xu
- College of Biomedical Information and Engineering, Hainan General Hospital, Hainan Affiliated Hospital of Hainan Medical University, Haikou, China
| | | | - Yucheng Xia
- College of Biomedical Information and Engineering, Hainan General Hospital, Hainan Affiliated Hospital of Hainan Medical University, Haikou, China
| | - Jiale Cai
- College of Biomedical Information and Engineering, Hainan General Hospital, Hainan Affiliated Hospital of Hainan Medical University, Haikou, China
| | - Yutong Shen
- College of Biomedical Information and Engineering, Hainan General Hospital, Hainan Affiliated Hospital of Hainan Medical University, Haikou, China
| | - Jiaqi Wang
- College of Biomedical Information and Engineering, Hainan General Hospital, Hainan Affiliated Hospital of Hainan Medical University, Haikou, China
| | - Jiazhu Chen
- College of Biomedical Information and Engineering, Hainan General Hospital, Hainan Affiliated Hospital of Hainan Medical University, Haikou, China
| | - Lamei Yin
- College of Biomedical Information and Engineering, Hainan General Hospital, Hainan Affiliated Hospital of Hainan Medical University, Haikou, China
| | - Bo Wang
- College of Biomedical Information and Engineering, Hainan General Hospital, Hainan Affiliated Hospital of Hainan Medical University, Haikou, China
| | - Deng Wu
- School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Hong Kong, China
| | - Kongning Li
- College of Biomedical Information and Engineering, Hainan General Hospital, Hainan Affiliated Hospital of Hainan Medical University, Haikou, China
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Kolinko Y, Kralickova M, Cendelin J. Reduction of Microvessel Number and Length in the Cerebellum of Purkinje Cell Degeneration Mice. CEREBELLUM (LONDON, ENGLAND) 2024; 23:471-478. [PMID: 37071329 DOI: 10.1007/s12311-023-01556-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/05/2023] [Indexed: 04/19/2023]
Abstract
Degenerative effects of nerve tissues are often accompanied by changes in vascularization. In this regard, knowledge about hereditary cerebellar degeneration is limited. In this study, we compared the vascularity of the individual cerebellar components of 3-month-old wild-type mice (n = 8) and Purkinje cell degeneration (pcd) mutant mice, which represent a model of hereditary cerebellar degeneration (n = 8). Systematic random samples of tissue sections were processed, and laminin was immunostained to visualize microvessels. A computer-assisted stereology system was used to quantify microvessel parameters including total number, total length, and associated densities in cerebellar layers. Our results in pcd mice revealed a 45% (p < 0.01) reduction in the total volume of the cerebellum, a 28% (p < 0.05) reduction in the total number of vessels and a lower total length, approaching 50% (p < 0.001), compared to the control mice. In pcd mutants, cerebellar degeneration is accompanied by significant reduction in the microvascular network that is proportional to the cerebellar volume reduction therefore does not change density of in the cerebellar gray matter of pcd mice.
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Affiliation(s)
- Yaroslav Kolinko
- Biomedical Center in Pilsen, Faculty of Medicine in Pilsen, Charles University, Pilsen, Czech Republic.
- Department of Histology and Embryology, Faculty of Medicine in Pilsen, Charles University, Pilsen, Czech Republic.
| | - Milena Kralickova
- Biomedical Center in Pilsen, Faculty of Medicine in Pilsen, Charles University, Pilsen, Czech Republic
- Department of Histology and Embryology, Faculty of Medicine in Pilsen, Charles University, Pilsen, Czech Republic
| | - Jan Cendelin
- Biomedical Center in Pilsen, Faculty of Medicine in Pilsen, Charles University, Pilsen, Czech Republic
- Department of Pathophysiology, Faculty of Medicine in Pilsen, Charles University, Pilsen, Czech Republic
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Huang BB, Fukuyama H, Burns SA, Fawzi AA. Imaging the Retinal Vascular Mural Cells In Vivo: Elucidating the Timeline of Their Loss in Diabetic Retinopathy. Arterioscler Thromb Vasc Biol 2024; 44:465-476. [PMID: 38152885 PMCID: PMC10842708 DOI: 10.1161/atvbaha.123.320169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 12/13/2023] [Indexed: 12/29/2023]
Abstract
BACKGROUND Vascular mural cells (VMCs) are integral components of the retinal vasculature with critical homeostatic functions such as maintaining the inner blood-retinal barrier and vascular tone, as well as supporting the endothelial cells. Histopathologic donor eye studies have shown widespread loss of pericytes and smooth muscle cells, the 2 main VMC types, suggesting these cells are critical to the pathogenesis of diabetic retinopathy (DR). There remain, however, critical gaps in our knowledge regarding the timeline of VMC demise in human DR. METHODS In this study, we address this gap using adaptive optics scanning laser ophthalmoscopy to quantify retinal VMC density in eyes with no retinal disease (healthy), subjects with diabetes without diabetic retinopathy, and those with clinical DR and diabetic macular edema. We also used optical coherence tomography angiography to quantify capillary density of the superficial and deep capillary plexuses in these eyes. RESULTS Our results indicate significant VMC loss in retinal arterioles before the appearance of classic clinical signs of DR (diabetes without diabetic retinopathy versus healthy, 5.0±2.0 versus 6.5±2.0 smooth muscle cells per 100 µm; P<0.05), while a significant reduction in capillary VMC density (5.1±2.3 in diabetic macular edema versus 14.9±6.0 pericytes per 100 µm in diabetes without diabetic retinopathy; P=0.01) and capillary density (superficial capillary plexus vessel density, 37.6±3.8 in diabetic macular edema versus 45.5±2.4 in diabetes without diabetic retinopathy; P<0.0001) is associated with more advanced stages of clinical DR, particularly diabetic macular edema. CONCLUSIONS Our results offer a new framework for understanding the pathophysiologic course of VMC compromise in DR, which may facilitate the development and monitoring of therapeutic strategies aimed at VMC preservation and potentially the prevention of clinical DR and its associated morbidity. Imaging retinal VMCs provides an unparalleled opportunity to visualize these cells in vivo and may have wider implications in a range of diseases where these cells are disrupted.
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Affiliation(s)
- Bonnie B. Huang
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Hisashi Fukuyama
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
- Department of Ophthalmology, Hyogo Medical University, Hyogo, Japan
| | | | - Amani A. Fawzi
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
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Mamelak M. The Alzheimer's Disease Brain, Its Microvasculature, and NADPH Oxidase. J Alzheimers Dis 2024; 99:S109-S118. [PMID: 37599534 DOI: 10.3233/jad-230415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/22/2023]
Abstract
The deterioration of the brain's microvasculature, particularly in the hippocampus, appears to be a very early event in the development of Alzheimer's disease (AD), preceding even the deposition of amyloid-β. A damaged microvasculature reduces the supply of oxygen and glucose to this region and limits the production of energy, ATP. The damage may be a function of the rise with age in the expression and activity of NADPH oxidase (NOX) in these microvessels. This rise renders these vessels vulnerable to the effects of oxidative stress and inflammation. The rise in NOX activity with age is even more marked in the AD brain where an inverse correlation has been demonstrated between NOX activity and cognitive ability. Apocynin, a putative NOX inhibitor, has been shown to block the damaging effects of NOX activation. Apocynin acts as a strong scavenger of H2O2, and as a weak scavenger of superoxide. Like apocynin, sodium oxybate (SO) has also been shown to block the toxic effects of NOX activation. The application of SO generates NADPH and ATP. SO inhibits oxidative stress and maintains normal cerebral ATP levels under hypoxic conditions. Moreover, it acts epigenetically to attenuate the expression of NOX. SO may delay the onset and slow the progress of AD by suppling energy and maintaining an antioxidative environment in the brain throughout the night. The slow wave activity produced by SO may also activate the glymphatic system and promote the clearance of amyloid-β from the brain.
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Affiliation(s)
- Mortimer Mamelak
- Department of Psychiatry, Baycrest Hospital, University of Toronto, Toronto, Ontario, Canada
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Steiner K, Humpel C. Beta-Amyloid Enhances Vessel Formation in Organotypic Brain Slices Connected to Microcontact Prints. Biomolecules 2023; 14:3. [PMID: 38275744 PMCID: PMC10812928 DOI: 10.3390/biom14010003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 11/24/2023] [Accepted: 12/13/2023] [Indexed: 01/27/2024] Open
Abstract
In Alzheimer's disease, the blood-brain barrier breakdown, blood vessel damage and re-organization are early events. Deposits of the small toxic peptide beta-amyloid (Aβ) cause the formation of extracellular plaques and accumulate in vessels disrupting the blood flow but may also play a role in blood clotting. In the present study, we aim to explore the impact of Aβ on the migration of endothelial cells and subsequent vessel formation. We use organotypic brain slices of postnatal day 10 wildtype mice (C57BL/6) and connect them to small microcontact prints (µCPs) of collagen. Our data show that laminin-positive endothelial cells migrate onto collagen µCPs, but without any vessel formation after 4 weeks. When the µCPs are loaded with human Aβ40, (aggregated) human Aβ42 and mouse Aβ42 peptides, the number and migration distance of endothelial cells are significantly reduced, but with a more pronounced subsequent vessel formation. The vessel formation is verified by zonula occludens (ZO)-1 and -2 stainings and confocal microscopy. In addition, the vessel formation is accompanied by a stronger GFAP-positive astroglial formation. Finally, we show that vessels can grow towards convergence when two opposed slices are connected via microcontact-printed lanes. In conclusion, our data show that Aβ promotes vessel formation, and organotypic brain slices connected to collagen µCPs provide a potent tool to study vessel formation.
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Affiliation(s)
| | - Christian Humpel
- Laboratory of Psychiatry and Experimental Alzheimer’s Research, Medical University of Innsbruck, 6020 Innsbruck, Austria;
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Morris GP, Foster CG, Courtney J, Collins JM, Cashion JM, Brown LS, Howells DW, DeLuca GC, Canty AJ, King AE, Ziebell JM, Sutherland BA. Microglia directly associate with pericytes in the central nervous system. Glia 2023; 71:1847-1869. [PMID: 36994950 PMCID: PMC10952742 DOI: 10.1002/glia.24371] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 03/15/2023] [Accepted: 03/20/2023] [Indexed: 03/31/2023]
Abstract
Cerebral blood flow (CBF) is important for the maintenance of brain function and its dysregulation has been implicated in Alzheimer's disease (AD). Microglia associations with capillaries suggest they may play a role in the regulation of CBF or the blood-brain-barrier (BBB). We explored the relationship between microglia and pericytes, a vessel-resident cell type that has a major role in the control of CBF and maintenance of the BBB, discovering a spatially distinct subset of microglia that closely associate with pericytes. We termed these pericyte-associated microglia (PEM). PEM are present throughout the brain and spinal cord in NG2DsRed × CX3 CR1+/GFP mice, and in the human frontal cortex. Using in vivo two-photon microscopy, we found microglia residing adjacent to pericytes at all levels of the capillary tree and found they can maintain their position for at least 28 days. PEM can associate with pericytes lacking astroglial endfeet coverage and capillary vessel width is increased beneath pericytes with or without an associated PEM, but capillary width decreases if a pericyte loses a PEM. Deletion of the microglia fractalkine receptor (CX3 CR1) did not disrupt the association between pericytes and PEM. Finally, we found the proportion of microglia that are PEM declines in the superior frontal gyrus in AD. In summary, we identify microglia that specifically associate with pericytes and find these are reduced in number in AD, which may be a novel mechanism contributing to vascular dysfunction in neurodegenerative diseases.
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Affiliation(s)
- Gary P. Morris
- Tasmanian School of Medicine, College of Health and MedicineUniversity of TasmaniaHobartTasmaniaAustralia
| | - Catherine G. Foster
- Tasmanian School of Medicine, College of Health and MedicineUniversity of TasmaniaHobartTasmaniaAustralia
| | - Jo‐Maree Courtney
- Tasmanian School of Medicine, College of Health and MedicineUniversity of TasmaniaHobartTasmaniaAustralia
| | - Jessica M. Collins
- Wicking Dementia Research and Education Centre, College of Health and MedicineUniversity of TasmaniaHobartTasmaniaAustralia
| | - Jake M. Cashion
- Tasmanian School of Medicine, College of Health and MedicineUniversity of TasmaniaHobartTasmaniaAustralia
| | - Lachlan S. Brown
- Tasmanian School of Medicine, College of Health and MedicineUniversity of TasmaniaHobartTasmaniaAustralia
| | - David W. Howells
- Tasmanian School of Medicine, College of Health and MedicineUniversity of TasmaniaHobartTasmaniaAustralia
| | - Gabriele C. DeLuca
- Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUK
| | - Alison J. Canty
- Wicking Dementia Research and Education Centre, College of Health and MedicineUniversity of TasmaniaHobartTasmaniaAustralia
- Global Brain Health InstituteTrinity CollegeDublinIreland
| | - Anna E. King
- Wicking Dementia Research and Education Centre, College of Health and MedicineUniversity of TasmaniaHobartTasmaniaAustralia
| | - Jenna M. Ziebell
- Wicking Dementia Research and Education Centre, College of Health and MedicineUniversity of TasmaniaHobartTasmaniaAustralia
| | - Brad A. Sutherland
- Tasmanian School of Medicine, College of Health and MedicineUniversity of TasmaniaHobartTasmaniaAustralia
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Abstract
Pericytes are specialized cells located in close proximity to endothelial cells within the microvasculature. They play a crucial role in regulating blood flow, stabilizing vessel walls, and maintaining the integrity of the blood-brain barrier. The loss of pericytes has been associated with the development and progression of various diseases, such as diabetes, Alzheimer's disease, sepsis, stroke, and traumatic brain injury. This review examines the detection of pericyte loss in different diseases, explores the methods employed to assess pericyte coverage, and elucidates the potential mechanisms contributing to pericyte loss in these pathological conditions. Additionally, current therapeutic strategies targeting pericytes are discussed, along with potential future interventions aimed at preserving pericyte function and promoting disease mitigation.
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Affiliation(s)
| | - Hongkuan Fan
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC 29425, USA;
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Jullienne A, Szu JI, Quan R, Trinh MV, Norouzi T, Noarbe BP, Bedwell AA, Eldridge K, Persohn SC, Territo PR, Obenaus A. Cortical cerebrovascular and metabolic perturbations in the 5xFAD mouse model of Alzheimer's disease. Front Aging Neurosci 2023; 15:1220036. [PMID: 37533765 PMCID: PMC10392850 DOI: 10.3389/fnagi.2023.1220036] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 07/03/2023] [Indexed: 08/04/2023] Open
Abstract
Introduction The 5xFAD mouse is a popular model of familial Alzheimer's disease (AD) that is characterized by early beta-amyloid (Aβ) deposition and cognitive decrements. Despite numerous studies, the 5xFAD mouse has not been comprehensively phenotyped for vascular and metabolic perturbations over its lifespan. Methods Male and female 5xFAD and wild type (WT) littermates underwent in vivo 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) imaging at 4, 6, and 12 months of age to assess regional glucose metabolism. A separate cohort of mice (4, 8, 12 months) underwent "vessel painting" which labels all cerebral vessels and were analyzed for vascular characteristics such as vessel density, junction density, vessel length, network complexity, number of collaterals, and vessel diameter. Results With increasing age, vessels on the cortical surface in both 5xFAD and WT mice showed increased vessel length, vessel and junction densities. The number of collateral vessels between the middle cerebral artery (MCA) and the anterior and posterior cerebral arteries decreased with age but collateral diameters were significantly increased only in 5xFAD mice. MCA total vessel length and junction density were decreased in 5xFAD mice compared to WT at 4 months. Analysis of 18F-FDG cortical uptake revealed significant differences between WT and 5xFAD mice spanning 4-12 months. Broadly, 5xFAD males had significantly increased 18F-FDG uptake at 12 months compared to WT mice. In most cortical regions, female 5xFAD mice had reduced 18F-FDG uptake compared to WT across their lifespan. Discussion While the 5xFAD mouse exhibits AD-like cognitive deficits as early as 4 months of age that are associated with increasing Aβ deposition, we only found significant differences in cortical vascular features in males, not in females. Interestingly, 5xFAD male and female mice exhibited opposite effects in 18F-FDG uptake. The MCA supplies blood to large portions of the somatosensory cortex and portions of motor and visual cortex and increased vessel length alongside decreased collaterals which coincided with higher metabolic rates in 5xFAD mice. Thus, a potential mismatch between metabolic demand and vascular delivery of nutrients in the face of increasing Aβ deposition could contribute to the progressive cognitive deficits seen in the 5xFAD mouse model.
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Affiliation(s)
- Amandine Jullienne
- Department of Pediatrics, School of Medicine, University of California, Irvine, Irvine, CA, United States
| | - Jenny I. Szu
- Department of Pediatrics, School of Medicine, University of California, Irvine, Irvine, CA, United States
| | - Ryan Quan
- Department of Pediatrics, School of Medicine, University of California, Irvine, Irvine, CA, United States
| | - Michelle V. Trinh
- Department of Pediatrics, School of Medicine, University of California, Irvine, Irvine, CA, United States
| | - Tannoz Norouzi
- Department of Pediatrics, School of Medicine, University of California, Irvine, Irvine, CA, United States
| | - Brenda P. Noarbe
- Department of Pediatrics, School of Medicine, University of California, Irvine, Irvine, CA, United States
| | - Amanda A. Bedwell
- Stark Neurosciences Research Institute, School of Medicine, Indiana University, Indianapolis, IN, United States
| | - Kierra Eldridge
- Stark Neurosciences Research Institute, School of Medicine, Indiana University, Indianapolis, IN, United States
| | - Scott C. Persohn
- Stark Neurosciences Research Institute, School of Medicine, Indiana University, Indianapolis, IN, United States
| | - Paul R. Territo
- Stark Neurosciences Research Institute, School of Medicine, Indiana University, Indianapolis, IN, United States
- Department of Medicine, School of Medicine, Indiana University, Indianapolis, IN, United States
| | - Andre Obenaus
- Department of Pediatrics, School of Medicine, University of California, Irvine, Irvine, CA, United States
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Dabravolski SA, Markin AM, Andreeva ER, Eremin II, Orekhov AN, Melnichenko AA. Emerging role of pericytes in therapy of cardiovascular diseases. Biomed Pharmacother 2022; 156:113928. [DOI: 10.1016/j.biopha.2022.113928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 10/17/2022] [Accepted: 10/24/2022] [Indexed: 11/17/2022] Open
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Littau JL, Velilla L, Hase Y, Villalba‐Moreno ND, Hagel C, Drexler D, Osorio Restrepo S, Villegas A, Lopera F, Vargas S, Glatzel M, Krasemann S, Quiroz YT, Arboleda‐Velasquez JF, Kalaria R, Sepulveda‐Falla D. Evidence of beta amyloid independent small vessel disease in familial Alzheimer's disease. Brain Pathol 2022; 32:e13097. [PMID: 35695802 PMCID: PMC9616091 DOI: 10.1111/bpa.13097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 05/24/2022] [Indexed: 12/04/2022] Open
Abstract
We studied small vessel disease (SVD) pathology in Familial Alzheimer's disease (FAD) subjects carrying the presenilin 1 (PSEN1) p.Glu280Ala mutation in comparison to those with sporadic Alzheimer's disease (SAD) as a positive control for Alzheimer's pathology and Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) bearing different NOTCH3 mutations, as positive controls for SVD pathology. Upon magnetic resonance imaging (MRI) in life, some FAD showed mild white matter hyperintensities and no further radiologic evidence of SVD. In post-mortem studies, total SVD pathology in cortical areas and basal ganglia was similar in PSEN1 FAD and CADASIL subjects, except for the feature of arteriosclerosis which was higher in CADASIL subjects than in PSEN1 FAD subjects. Further only a few SAD subjects showed a similar degree of SVD pathology as observed in CADASIL. Furthermore, we found significantly enlarged perivascular spaces in vessels devoid of cerebral amyloid angiopathy in FAD compared with SAD and CADASIL subjects. As expected, there was greater fibrinogen-positive perivascular reactivity in CADASIL but similar reactivity in PSEN1 FAD and SAD groups. Fibrinogen immunoreactivity correlated with onset age in the PSEN1 FAD cases, suggesting increased vascular permeability may contribute to cognitive decline. Additionally, we found reduced perivascular expression of PDGFRβ AQP4 in microvessels with enlarged PVS in PSEN1 FAD cases. We demonstrate that there is Aβ-independent SVD pathology in PSEN1 FAD, that was marginally lower than that in CADASIL subjects although not evident by MRI. These observations suggest presence of covert SVD even in PSEN1, contributing to disease progression. As is the case in SAD, these consequences may be preventable by early recognition and actively controlling vascular disease risk, even in familial forms of dementia.
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Affiliation(s)
- Jessica Lisa Littau
- Institute of NeuropathologyUniversity Medical Center Hamburg‐EppendorfHamburgGermany
| | - Lina Velilla
- Neuroscience Group of AntioquiaUniversity of AntioquiaMedellín
| | - Yoshiki Hase
- Neurovascular Research GroupTranslational and Clinical Research Institute, Newcastle UniversityNewcastle upon Tyne
| | | | - Christian Hagel
- Institute of NeuropathologyUniversity Medical Center Hamburg‐EppendorfHamburgGermany
| | - Dagmar Drexler
- Institute of NeuropathologyUniversity Medical Center Hamburg‐EppendorfHamburgGermany
| | | | - Andres Villegas
- Neuroscience Group of AntioquiaUniversity of AntioquiaMedellín
| | | | - Sergio Vargas
- Department of Radiology, Neuroradiology SectionUniversidad de AntioquiaMedellínColombia
| | - Markus Glatzel
- Institute of NeuropathologyUniversity Medical Center Hamburg‐EppendorfHamburgGermany
| | - Susanne Krasemann
- Institute of NeuropathologyUniversity Medical Center Hamburg‐EppendorfHamburgGermany
| | - Yakeel T. Quiroz
- Massachusetts General HospitalHarvard Medical SchoolBostonMassachusettsUSA
| | - Joseph F. Arboleda‐Velasquez
- Schepens Eye Research Institute of Mass Eye and Ear and the Department of Ophthalmology at Harvard Medical SchoolBostonMassachusetts
| | - Rajesh Kalaria
- Neurovascular Research GroupTranslational and Clinical Research Institute, Newcastle UniversityNewcastle upon Tyne
| | - Diego Sepulveda‐Falla
- Institute of NeuropathologyUniversity Medical Center Hamburg‐EppendorfHamburgGermany
- Neuroscience Group of AntioquiaUniversity of AntioquiaMedellín
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da Silva MV, Ouellette J, Lacoste B, Comin CH. An analysis of the influence of transfer learning when measuring the tortuosity of blood vessels. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2022; 225:107021. [PMID: 35914440 DOI: 10.1016/j.cmpb.2022.107021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 07/10/2022] [Accepted: 07/11/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND AND OBJECTIVE Convolutional Neural Networks (CNNs) can provide excellent results regarding the segmentation of blood vessels. One important aspect of CNNs is that they can be trained on large amounts of data and then be made available, for instance, in image processing software. The pre-trained CNNs can then be easily applied in downstream blood vessel characterization tasks, such as the calculation of the length, tortuosity, or caliber of the blood vessels. Yet, it is still unclear if pre-trained CNNs can provide robust, unbiased, results in downstream tasks involving the morphological analysis of blood vessels. Here, we focus on measuring the tortuosity of blood vessels and investigate to which extent CNNs may provide biased tortuosity values even after fine-tuning the network to a new dataset under study. METHODS We develop a procedure for quantifying the influence of CNN pre-training in downstream analyses involving the measurement of morphological properties of blood vessels. Using the methodology, we compare the performance of CNNs that were trained on images containing blood vessels having high tortuosity with CNNs that were trained on blood vessels with low tortuosity and fine-tuned on blood vessels with high tortuosity. The opposite situation is also investigated. RESULTS We show that the tortuosity values obtained by a CNN trained from scratch on a dataset may not agree with those obtained by a fine-tuned network that was pre-trained on a dataset having different tortuosity statistics. In addition, we show that improving the segmentation accuracy does not necessarily lead to better tortuosity estimation. To mitigate the aforementioned issues, we propose the application of data augmentation techniques even in situations where they do not improve segmentation performance. For instance, we found that the application of elastic transformations was enough to prevent an underestimation of 8% of blood vessel tortuosity when applying CNNs to different datasets. CONCLUSIONS The results highlight the importance of developing new methodologies for training CNNs with the specific goal of reducing the error of morphological measurements, as opposed to the traditional approach of using segmentation accuracy as a proxy metric for performance evaluation.
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Affiliation(s)
- Matheus V da Silva
- Department of Computer Science, Federal University of São Carlos, São Carlos, SP, Brazil
| | - Julie Ouellette
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada; Neuroscience Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Baptiste Lacoste
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Cesar H Comin
- Department of Computer Science, Federal University of São Carlos, São Carlos, SP, Brazil.
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13
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Fisher RA, Miners JS, Love S. Pathological changes within the cerebral vasculature in Alzheimer's disease: New perspectives. Brain Pathol 2022; 32:e13061. [PMID: 35289012 PMCID: PMC9616094 DOI: 10.1111/bpa.13061] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 02/11/2022] [Accepted: 02/21/2022] [Indexed: 12/14/2022] Open
Abstract
Cerebrovascular disease underpins vascular dementia (VaD), but structural and functional changes to the cerebral vasculature contribute to disease pathology and cognitive decline in Alzheimer's disease (AD). In this review, we discuss the contribution of cerebral amyloid angiopathy and non‐amyloid small vessel disease in AD, and the accompanying changes to the density, maintenance and remodelling of vessels (including alterations to the composition and function of the cerebrovascular basement membrane). We consider how abnormalities of the constituent cells of the neurovascular unit – particularly of endothelial cells and pericytes – and impairment of the blood‐brain barrier (BBB) impact on the pathogenesis of AD. We also discuss how changes to the cerebral vasculature are likely to impair Aβ clearance – both intra‐periarteriolar drainage (IPAD) and transport of Aβ peptides across the BBB, and how impaired neurovascular coupling and reduced blood flow in relation to metabolic demand increase amyloidogenic processing of APP and the production of Aβ. We review the vasoactive properties of Aβ peptides themselves, and the probable bi‐directional relationship between vascular dysfunction and Aβ accumulation in AD. Lastly, we discuss recent methodological advances in transcriptomics and imaging that have provided novel insights into vascular changes in AD, and recent advances in assessment of the retina that allow in vivo detection of vascular changes in the early stages of AD.
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Affiliation(s)
- Robert A Fisher
- Dementia Research Group, University of Bristol Medical School, Bristol, UK
| | - J Scott Miners
- Dementia Research Group, University of Bristol Medical School, Bristol, UK
| | - Seth Love
- Dementia Research Group, University of Bristol Medical School, Bristol, UK
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14
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Clark AT, Abrahamson EE, Harper MM, Ikonomovic MD. Chronic effects of blast injury on the microvasculature in a transgenic mouse model of Alzheimer's disease related Aβ amyloidosis. Fluids Barriers CNS 2022; 19:5. [PMID: 35012589 PMCID: PMC8751260 DOI: 10.1186/s12987-021-00301-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 12/22/2021] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Altered cerebrovascular function and accumulation of amyloid-β (Aβ) after traumatic brain injury (TBI) can contribute to chronic neuropathology and increase the risk for Alzheimer's disease (AD). TBI due to a blast-induced shock wave (bTBI) adversely affects the neurovascular unit (NVU) during the acute period after injury. However, the chronic effects of bTBI and Aβ on cellular components of the NVU and capillary network are not well understood. METHODS We exposed young adult (age range: 76-106 days) female transgenic (Tg) APP/PS1 mice, a model of AD-like Aβ amyloidosis, and wild type (Wt) mice to a single bTBI (~ 138 kPa or ~ 20 psi) or to a Sham procedure. At 3-months or 12-months survival after exposure, we quantified neocortical Aβ load in Tg mice, and percent contact area between aquaporin-4 (AQP4)-immunoreactive astrocytic end-feet and brain capillaries, numbers of PDGFRβ-immunoreactive pericytes, and capillary densities in both genotypes. RESULTS The astroglia AQP4-capillary contact area in the Tg-bTBI group was significantly lower than in the Tg-Sham group at 3-months survival. No significant changes in the AQP4-capillary contact area were observed in the Tg-bTBI group at 12-months survival or in the Wt groups. Capillary density in the Tg-bTBI group at 12-months survival was significantly higher compared to the Tg-Sham control and to the Tg-bTBI 3-months survival group. The Wt-bTBI group had significantly lower capillary density and pericyte numbers at 12-months survival compared to 3-months survival. When pericytes were quantified relative to capillary density, no significant differences were detected among the experimental groups, for both genotypes. CONCLUSION In conditions of high brain concentrations of human Aβ, bTBI exposure results in reduced AQP4 expression at the astroglia-microvascular interface, and in chronic capillary proliferation like what has been reported in AD. Long term microvascular changes after bTBI may contribute to the risk for developing chronic neurodegenerative disease later in life.
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Affiliation(s)
- Alexander T. Clark
- Department of Neurology, University of Pittsburgh School of Medicine, 3471 Fifth Ave, Pittsburgh, PA 15213 USA
| | - Eric E. Abrahamson
- Geriatric Research Education and Clinical Center, VA Pittsburgh Healthcare System, University Drive C, Pittsburgh, PA 15240 USA
- Department of Neurology, University of Pittsburgh School of Medicine, 3471 Fifth Ave, Pittsburgh, PA 15213 USA
| | - Matthew M. Harper
- The Iowa City VA Center for the Prevention and Treatment of Visual Loss, 601 Hwy 6 West, Iowa City, IA 52246 USA
- Department of Ophthalmology and Visual Sciences and Biology, University of Iowa, 200 Hawkins Dr, Iowa City, IA 52242 USA
| | - Milos D. Ikonomovic
- Geriatric Research Education and Clinical Center, VA Pittsburgh Healthcare System, University Drive C, Pittsburgh, PA 15240 USA
- Department of Neurology, University of Pittsburgh School of Medicine, 3471 Fifth Ave, Pittsburgh, PA 15213 USA
- Department of Psychiatry, University of Pittsburgh School of Medicine, Thomas Detre Hall of the WPH, Room 1421, 3811 O’Hara Street, Pittsburgh, PA 15213-2593 USA
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15
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Ruchoux MM, Kalaria RN, Román GC. The pericyte: A critical cell in the pathogenesis of CADASIL. CEREBRAL CIRCULATION - COGNITION AND BEHAVIOR 2021; 2:100031. [PMID: 34950895 PMCID: PMC8661128 DOI: 10.1016/j.cccb.2021.100031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 10/12/2021] [Accepted: 10/12/2021] [Indexed: 12/22/2022]
Abstract
CADASIL is the most common hereditary small vessel disease presenting with strokes and subcortical vascular dementia caused by mutations in the NOTCH3 gene. CADASIL is a vasculopathy primarily involving vascular smooth-muscle cells. Arteriolar and capillary pericyte damage or deficiency is a key feature in disease pathogenesis. Pericyte-mediated cerebral venous insufficiency may explain white matter lesions and increased perivascular spaces. Central role of the pericyte offers novel approaches to the treatment of CADASIL.
Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a hereditary small vessel disease presenting with migraine, mood and cognitive disorders, focal neurological deficits, recurrent ischemic attacks, lacunar infarcts and brain white matter changes. As they age, CADASIL patients invariably develop cognitive impairment and subcortical dementia. CADASIL is caused by missense mutations in the NOTCH3 gene resulting in a profound cerebral vasculopathy affecting primarily arterial vascular smooth muscle cells, which target the microcirculation and perfusion. Based on a thorough review of morphological lesions in arteries, veins, and capillaries in CADASIL, we surmise that arteriolar and capillary pericyte damage or deficiency appears a key feature in the pathogenesis of the disease. This may affect critical pericyte-endothelial interactions causing stroke injury and vasomotor disturbances. Changes in microvascular permeability due to perhaps localized blood-brain barrier alterations and pericyte secretory dysfunction likely contribute to delayed neuronal as well as glial cell death. Moreover, pericyte-mediated cerebral venous insufficiency may explain white matter lesions and the dilatation of Virchow-Robin perivascular spaces typical of CADASIL. The postulated central role of the pericyte offers some novel approaches to the study and treatment of CADASIL and enable elucidation of other forms of cerebral small vessel diseases and subcortical vascular dementia.
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Affiliation(s)
- Marie-Magdeleine Ruchoux
- Former researcher, Université d'Artois, Blood-Brain-Barrier Laboratory Lens France, Former advisor, Alzheimer's Clinic Methodist Neurological Institute, Houston TX, USA
| | - Raj N Kalaria
- Translational and Clinical Research Institute, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Gustavo C Román
- Methodist Neurological Institute, Department of Neurology, Houston Methodist Hospital Houston TX 77030, USA, Weill Cornell Medical College, New York NY, USA and Texas A&M Medical School, Bryan TX, USA
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16
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Skaaraas GHES, Melbye C, Puchades MA, Leung DSY, Jacobsen Ø, Rao SB, Ottersen OP, Leergaard TB, Torp R. Cerebral Amyloid Angiopathy in a Mouse Model of Alzheimer's Disease Associates with Upregulated Angiopoietin and Downregulated Hypoxia-Inducible Factor. J Alzheimers Dis 2021; 83:1651-1663. [PMID: 34459401 PMCID: PMC8609707 DOI: 10.3233/jad-210571] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Background: Vascular pathology is a common feature in patients with advanced Alzheimer’s disease, with cerebral amyloid angiopathy (CAA) and microvascular changes commonly observed at autopsies and in genetic mouse models. However, despite a plethora of studies addressing the possible impact of CAA on brain vasculature, results have remained contradictory, showing reduced, unchanged, or even increased capillary densities in human and rodent brains overexpressing amyloid-β in Alzheimer’s disease and Down’s syndrome. Objective: We asked if CAA is associated with changes in angiogenetic factors or receptors and if so, whether this would translate into morphological alterations in pericyte coverage and vessel density. Methods: We utilized the transgenic mice carrying the Arctic (E693G) and Swedish (KM670/6701NL) amyloid precursor protein which develop severe CAA in addition to parenchymal plaques. Results: The main finding of the present study was that CAA in Tg-ArcSwe mice is associated with upregulated angiopoietin and downregulated hypoxia-inducible factor. In the same mice, we combined immunohistochemistry and electron microscopy to quantify the extent of CAA and investigate to which degree vessels associated with amyloid plaques were pathologically affected. We found that despite a severe amount of CAA and alterations in several angiogenetic factors in Tg-ArcSwe mice, this was not translated into significant morphological alterations like changes in pericyte coverage or vessel density. Conclusion: Our data suggest that CAA does not impact vascular density but might affect capillary turnover by causing changes in the expression levels of angiogenetic factors.
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Affiliation(s)
| | - Christoffer Melbye
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Maja A Puchades
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Doreen Siu Yi Leung
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | | | - Shreyas B Rao
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Ole Petter Ottersen
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Trygve B Leergaard
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Reidun Torp
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
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17
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Ding R, Hase Y, Burke M, Foster V, Stevenson W, Polvikoski T, Kalaria RN. Loss with ageing but preservation of frontal cortical capillary pericytes in post-stroke dementia, vascular dementia and Alzheimer's disease. Acta Neuropathol Commun 2021; 9:130. [PMID: 34340718 PMCID: PMC8330023 DOI: 10.1186/s40478-021-01230-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 07/16/2021] [Indexed: 01/19/2023] Open
Abstract
Cerebral pericytes are an integral component of the neurovascular unit, which governs the blood–brain barrier. There is paucity of knowledge on cortical pericytes across different dementias. We quantified cortical pericytes in capillaries in 124 post-mortem brains from subjects with post-stroke dementia (PSD), vascular dementia (VaD), Alzheimer’s disease (AD) and AD-VaD (Mixed) and, post-stroke non-demented (PSND) stroke survivors as well as normal ageing controls. Collagen 4 (COL4)-positive nucleated pericyte soma were identified as protrusions on capillaries of the frontal cortex. The COL4-positive somata or nodule-like cell bodies were also verified by platelet derived growth factor receptor-β (PDGFR-β) immunohistochemistry. The mean (± SEM) pericyte somata in frontal cortical capillaries in normal young controls (46–65 years of age) was estimated as 5.2 ± 0.2 per mm capillary length. This number was reduced by 45% in older controls (> 78 years) to 2.9 ± 0.1 per mm capillary length (P < 0.001). We further found that the numbers of pericyte cell bodies per COL4 mm2 area or per mm capillary length were not decreased but rather preserved or increased in PSD, AD and Mixed dementia groups compared to similar age older controls (P < 0.01). Consistent with this, we noted that capillary length densities identified by the endothelial marker glucose transporter 1 or COL4 were not different across the dementias compared to older controls. There was a negative correlation with age (P < 0.001) suggesting fewer pericyte somata in older age, although the % COL4 immunoreactive capillary area was increased in older controls compared to young controls. Using a proven reliable method to quantify COL4-positive nucleated pericytes, our observations demonstrate ageing related loss but mostly preserved pericytes in the frontal cortex of vascular and AD dementias. We suggest there is differential regulation of capillary pericytes in the frontal lobe between the cortex and white matter in ageing-related dementias.
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18
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Quan W, Luo Q, Hao W, Tomic I, Furihata T, Schulz-Schäffer W, Menger MD, Fassbender K, Liu Y. Haploinsufficiency of microglial MyD88 ameliorates Alzheimer's pathology and vascular disorders in APP/PS1-transgenic mice. Glia 2021; 69:1987-2005. [PMID: 33934399 DOI: 10.1002/glia.24007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 03/29/2021] [Accepted: 04/01/2021] [Indexed: 11/12/2022]
Abstract
Growing evidence indicates that innate immune molecules regulate microglial activation in Alzheimer's disease (AD); however, their effects on amyloid pathology and neurodegeneration remain inconclusive. Here, we conditionally deleted one allele of myd88 gene specifically in microglia in APP/PS1-transgenic mice by 6 months and analyzed AD-associated pathologies by 9 months. We observed that heterozygous deletion of myd88 gene in microglia decreased cerebral amyloid β (Aβ) load and improved cognitive function of AD mice, which was correlated with reduced number of microglia in the brain and inhibited transcription of inflammatory genes, for example, tnf-α and il-1β, in both brain tissues and individual microglia. To investigate mechanisms underlying the pathological improvement, we observed that haploinsufficiency of MyD88 increased microglial recruitment toward Aβ deposits, which might facilitate Aβ clearance. Microglia with haploinsufficient expression of MyD88 also increased vasculature in the brain of APP/PS1-transgenic mice, which was associated with up-regulated transcription of osteopontin and insulin-like growth factor genes in microglia. Moreover, MyD88-haploinsufficient microglia elevated protein levels of LRP1 in cerebral capillaries of APP/PS1-transgenic mice. Cell culture experiments further showed that treatments with interleukin-1β decreased LRP1 expression in pericytes. In summary, haploinsufficiency of MyD88 in microglia at a late disease stage attenuates pro-inflammatory activation and amyloid pathology, prevents the impairment of microvasculature and perhaps also protects LRP1-mediated Aβ clearance in the brain of APP/PS1-transgenic mice, all of which improves neuronal function of AD mice.
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Affiliation(s)
- Wenqiang Quan
- Department of Neurology, Saarland University, Homburg, Germany.,German Institute for Dementia Prevention (DIDP), Saarland University, Homburg, Germany.,Department of Clinical Laboratory, Tongji Hospital, Tongji University Medical School, Shanghai, China
| | - Qinghua Luo
- Department of Neurology, Saarland University, Homburg, Germany.,German Institute for Dementia Prevention (DIDP), Saarland University, Homburg, Germany
| | - Wenlin Hao
- Department of Neurology, Saarland University, Homburg, Germany.,German Institute for Dementia Prevention (DIDP), Saarland University, Homburg, Germany
| | - Inge Tomic
- Department of Neurology, Saarland University, Homburg, Germany.,German Institute for Dementia Prevention (DIDP), Saarland University, Homburg, Germany
| | - Tomomi Furihata
- Department of Clinical Pharmacy and Experimental Therapeutics, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
| | | | - Michael D Menger
- Department of Experimental Surgery, Saarland University, Homburg, Germany
| | - Klaus Fassbender
- Department of Neurology, Saarland University, Homburg, Germany.,German Institute for Dementia Prevention (DIDP), Saarland University, Homburg, Germany
| | - Yang Liu
- Department of Neurology, Saarland University, Homburg, Germany.,German Institute for Dementia Prevention (DIDP), Saarland University, Homburg, Germany
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19
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Ji X, Ferreira T, Friedman B, Liu R, Liechty H, Bas E, Chandrashekar J, Kleinfeld D. Brain microvasculature has a common topology with local differences in geometry that match metabolic load. Neuron 2021; 109:1168-1187.e13. [PMID: 33657412 PMCID: PMC8525211 DOI: 10.1016/j.neuron.2021.02.006] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 12/09/2020] [Accepted: 02/03/2021] [Indexed: 01/03/2023]
Abstract
The microvasculature underlies the supply networks that support neuronal activity within heterogeneous brain regions. What are common versus heterogeneous aspects of the connectivity, density, and orientation of capillary networks? To address this, we imaged, reconstructed, and analyzed the microvasculature connectome in whole adult mice brains with sub-micrometer resolution. Graph analysis revealed common network topology across the brain that leads to a shared structural robustness against the rarefaction of vessels. Geometrical analysis, based on anatomically accurate reconstructions, uncovered a scaling law that links length density, i.e., the length of vessel per volume, with tissue-to-vessel distances. We then derive a formula that connects regional differences in metabolism to differences in length density and, further, predicts a common value of maximum tissue oxygen tension across the brain. Last, the orientation of capillaries is weakly anisotropic with the exception of a few strongly anisotropic regions; this variation can impact the interpretation of fMRI data.
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Affiliation(s)
- Xiang Ji
- Department of Physics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Tiago Ferreira
- Howard Hughes Medical Institute, Janelia Research Campus, Ashburn, VA 20147, USA
| | - Beth Friedman
- Department of Computer Science and Engineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Rui Liu
- Department of Physics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Hannah Liechty
- Department of Physics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Erhan Bas
- Howard Hughes Medical Institute, Janelia Research Campus, Ashburn, VA 20147, USA
| | | | - David Kleinfeld
- Department of Physics, University of California, San Diego, La Jolla, CA 92093, USA; Section of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA.
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20
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Loesch A. On P2X receptors in the brain: microvessels. Dedicated to the memory of the late Professor Geoffrey Burnstock (1929-2020). Cell Tissue Res 2021; 384:577-588. [PMID: 33755804 DOI: 10.1007/s00441-021-03411-0] [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] [Received: 10/27/2020] [Accepted: 01/01/2021] [Indexed: 12/13/2022]
Abstract
This tribute article presents selected immunocytochemical and transmission electron microscope data on the location of ATP-gated P2X receptor in the rat brain, as studied in the 1990s in Prof G. Burnstock's laboratory at University College London. There are examples of immuno-ultrastructural findings and introductory information about pre- and post-synaptic location of P2X receptors in the rat cerebellum and endocrine hypothalamus to support the concept of purinergic transmission in the central nervous system. Then findings of diverse immunoreactivity for P2X1, P2X2, P2X4, and P2X6 receptors associated with brain microvessels are shown, including vascular endothelium and pericytes as well as perivascular astrocytes and neuronal components. These findings imply the involvement of P2X receptors and hence purinergic signalling in the neurovascular unit, at least in microvessels in the rat cerebellum and hypothalamic paraventricular and supraoptic nuclei examined here. Various aspects of P2X receptors in brain microvessels are discussed.
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Affiliation(s)
- Andrzej Loesch
- Centre for Rheumatology and Connective Tissue Diseases, Division of Medicine, University College London Medical School, Royal Free Campus, London, UK.
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