1
|
Duan Y, Yuan C, Suo X, Li Y, Shi L, Cao L, Kong X, Zhang Y, Zheng H, Wang Q. Bat-Origin Swine Acute Diarrhea Syndrome Coronavirus Is Lethal to Neonatal Mice. J Virol 2023; 97:e0019023. [PMID: 36877051 PMCID: PMC10062167 DOI: 10.1128/jvi.00190-23] [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: 02/02/2023] [Accepted: 02/17/2023] [Indexed: 03/07/2023] Open
Abstract
Bats are reservoirs for diverse coronaviruses, including swine acute diarrhea syndrome coronavirus (SADS-CoV). SADS-CoV has been reported to have broad cell tropism and inherent potential to cross host species barriers for dissemination. We rescued synthetic wild-type SADS-CoV using one-step assembly of a viral cDNA clone by homologous recombination in yeast. Furthermore, we characterized SADS-CoV replication in vitro and in neonatal mice. We found that SADS-CoV caused severe watery diarrhea, weight loss, and a 100% fatality rate in 7- and 14-day-old mice after intracerebral infection. We also detected SADS-CoV-specific N protein in the brain, lungs, spleen, and intestines of infected mice. Furthermore, SADS-CoV infection triggers excessive cytokine expression that encompasses a broad array of proinflammatory mediators, including interleukin 1β (IL-1β), IL-6, IL-8, tumor necrosis factor alpha (TNF-α), C-X-C motif chemokine ligand 10 (CXCL10), interferon beta (IFN-β), IFN-γ, and IFN-λ3. This study highlights the importance of identifying neonatal mice as a model for developing vaccines or antiviral drugs against SADS-CoV infection. IMPORTANCE SADS-CoV is the documented spillover of a bat coronavirus that causes severe disease in pigs. Pigs are in frequent contact with both humans and other animals and theoretically possess a greater chance, compared to many other species, of promoting cross-species viral transmission. SADS-CoV has been reported to have broad cell tropism and inherent potential to cross host species barriers for dissemination. Animal models are an essential feature of the vaccine design toolkit. Compared with neonatal piglets, the mouse is small, making it an economical choice for animal models for SADS-CoV vaccine design. This study showed the pathology of neonatal mice infected with SADS-CoV, which should be very useful for vaccine and antiviral studies.
Collapse
Affiliation(s)
- Yueyue Duan
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu, China
- State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Diseases Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
- Chengdu National Agricultural Science and Technology Center, Chengdu, China
| | - Cong Yuan
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu, China
- State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Diseases Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
- Chengdu National Agricultural Science and Technology Center, Chengdu, China
| | - Xuepeng Suo
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu, China
- State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Diseases Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
- Chengdu National Agricultural Science and Technology Center, Chengdu, China
| | - Yanhua Li
- College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, China
| | - Lei Shi
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu, China
- State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Diseases Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
- Chengdu National Agricultural Science and Technology Center, Chengdu, China
| | - Liyan Cao
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu, China
- State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Diseases Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
- Chengdu National Agricultural Science and Technology Center, Chengdu, China
| | - Xiangyu Kong
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu, China
- State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Diseases Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
- Chengdu National Agricultural Science and Technology Center, Chengdu, China
| | - Yu Zhang
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu, China
- State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Diseases Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
- Chengdu National Agricultural Science and Technology Center, Chengdu, China
| | - Haixue Zheng
- State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Diseases Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Qi Wang
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu, China
- State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Diseases Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
- Chengdu National Agricultural Science and Technology Center, Chengdu, China
| |
Collapse
|
2
|
Streit WJ, Rotter J, Winter K, Müller W, Khoshbouei H, Bechmann I. Droplet Degeneration of Hippocampal and Cortical Neurons Signifies the Beginning of Neuritic Plaque Formation. J Alzheimers Dis 2021; 85:1701-1720. [PMID: 34958037 DOI: 10.3233/jad-215334] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Neuritic plaques contain neural and microglial elements, and amyloid-β protein (Aβ), but their pathogenesis remains unknown. OBJECTIVE Elucidate neuritic plaque pathogenesis. METHODS Histochemical visualization of hyperphosphorylated-tau positive (p-tau+) structures, microglia, Aβ, and iron. RESULTS Disintegration of large projection neurons in human hippocampus and neocortex presents as droplet degeneration: pretangle neurons break up into spheres of numerous p-tau+ droplets of various sizes, which marks the beginning of neuritic plaques. These droplet spheres develop in the absence of colocalized Aβ deposits but once formed become encased in diffuse Aβ with great specificity. In contrast, neurofibrillary tangles often do not colocalize with Aβ. Double-labelling for p-tau and microglia showed a lack of microglial activation or phagocytosis of p-tau+ degeneration droplets but revealed massive upregulation of ferritin in microglia suggesting presence of high levels of free iron. Perl's Prussian blue produced positive staining of microglia, droplet spheres, and Aβ plaque cores supporting the suggestion that droplet degeneration of pretangle neurons in the hippocampus and cortex represents ferroptosis, which is accompanied by the release of neuronal iron extracellularly. CONCLUSION Age-related iron accumulation and ferroptosis in the CNS likely trigger at least two endogenous mechanisms of neuroprotective iron sequestration and chelation, microglial ferritin expression and Aβ deposition, respectively, both contributing to the formation of neuritic plaques. Since neurofibrillary tangles and Aβ deposits colocalize infrequently, tangle formation likely does not involve release of neuronal iron extracellularly. In human brain, targeted deposition of Aβ occurs specifically in response to ongoing ferroptotic droplet degeneration thereby producing neuritic plaques.
Collapse
Affiliation(s)
- Wolfgang J Streit
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, FL, USA
| | - Jonas Rotter
- Institute of Anatomy, Leipzig University, Leipzig, Germany
| | - Karsten Winter
- Institute of Anatomy, Leipzig University, Leipzig, Germany
| | - Wolf Müller
- Department of Neuropathology, Leipzig University, Leipzig, Germany
| | - Habibeh Khoshbouei
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, FL, USA
| | - Ingo Bechmann
- Institute of Anatomy, Leipzig University, Leipzig, Germany
| |
Collapse
|
3
|
Putilina MV, Grishin DV. SARS-CoV-2 (COVID-19) as a Predictor of Neuroinflammation and Neurodegeneration: Potential Treatment Strategies. ACTA ACUST UNITED AC 2021; 51:577-582. [PMID: 34176996 PMCID: PMC8219508 DOI: 10.1007/s11055-021-01108-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 09/14/2020] [Indexed: 02/07/2023]
Abstract
The SARS-CoV-2 (COVID-19) pandemic has attracted attention to the challenge of neuroinflammation as an unavoidable component of viral infections. Acute neuroinflammatory responses include activation of resident tissue macrophages in the CNS followed by release of a variety of cytokines and chemokines associated with activation of oxidative stress and delayed neuron damage. This makes the search for treatments with indirect anti-inflammatory properties relevant. From this point of view, attention is focused on further study of the treatment of patients with COVID-19 with dipyridamole (Curantil) which, having antiviral and anti-inflammatory effects, can inhibit acute inflammatory activity and progression of fibrosis, is a drug with potential, especially among patients with early increases in the D-dimer concentration and severe signs of microangiopathy.
Collapse
Affiliation(s)
- M V Putilina
- Pirogov Russian National Research Medical University, Russian Ministry of Health, Moscow, Russia
| | - D V Grishin
- Pirogov Russian National Research Medical University, Russian Ministry of Health, Moscow, Russia.,Filatov City Clinical Hospital No. 15, Moscow Health Department, Moscow, Russia
| |
Collapse
|
4
|
Putilina M, Grishin D. SARS-CoV-2 (COVID-19) as a predictor of neuroinflammation and neurodegeneration: potential therapy strategies. Zh Nevrol Psikhiatr Im S S Korsakova 2020; 120:58-64. [DOI: 10.17116/jnevro202012008258] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
|
5
|
Streit WJ, Braak H, Del Tredici K, Leyh J, Lier J, Khoshbouei H, Eisenlöffel C, Müller W, Bechmann I. Microglial activation occurs late during preclinical Alzheimer's disease. Glia 2018; 66:2550-2562. [PMID: 30417428 DOI: 10.1002/glia.23510] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 07/18/2018] [Accepted: 07/18/2018] [Indexed: 01/10/2023]
Abstract
Sporadic Alzheimer's disease (AD) is marked by a lengthy preclinical phase during which patients are nonsymptomatic but show pathology in variable manifestations. Whether or not neuroinflammation occurs in such nondemented individuals is unknown. We evaluated the medial temporal lobe of 66 nondemented subjects, aged 42-93, in terms of tau pathology, Aβ deposition, and microglial activation. We show that 100% of subjects had neurofibrillary degeneration (NFD), 35% had Aβ deposits, and 8% revealed microglial activation in individuals where early amyloid formation was apparent by Congo Red staining. Amyloid-induced neuroinflammatory clusters of Iba1, CD68, and ferritin-positive microglia were evident in the immediate vicinity of aggregated Aβ. Microglia in the adjacent neuropil were nonactivated. Thus, neuroinflammation in AD represents a highly localized phagocyte reaction, essentially a foreign body response, geared toward removal of insoluble Aβ. Because clustered microglia in some amyloid plaques were dystrophic and ferritin-positive, we hypothesize that these cells were exhausted by their attempts to remove the aggregated, insoluble Aβ. Our findings show that the sequence of pathologic events in AD begins with tau pathology, followed by Aβ deposition, and then by microglial activation. Because only 8% of our subjects revealed all three hallmark pathologic features, we propose that these nondemented individuals were near the threshold of transitioning from nonsymptomatic to symptomatic disease. The onset of neuroinflammation in AD may thus represent a tipping point in AD pathogenesis. Our study suggests that the role of microglia in AD pathogenesis entails primarily the attempted removal of potentially toxic, extracellular material.
Collapse
Affiliation(s)
- Wolfgang J Streit
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, Florida
| | - Heiko Braak
- Clinical Neuroanatomy (Department of Neurology), Center for Biomedical Research, University of Ulm, Ulm, Germany
| | - Kelly Del Tredici
- Clinical Neuroanatomy (Department of Neurology), Center for Biomedical Research, University of Ulm, Ulm, Germany
| | - Judith Leyh
- Institute of Anatomy, Leipzig University, Leipzig, Germany
| | - Julia Lier
- Institute of Anatomy, Leipzig University, Leipzig, Germany
| | - Habibeh Khoshbouei
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, Florida
| | | | - Wolf Müller
- Department of Neuropathology, Leipzig University, Leipzig, Germany
| | - Ingo Bechmann
- Institute of Anatomy, Leipzig University, Leipzig, Germany
| |
Collapse
|
6
|
Craddock TJA, Michalovicz LT, Kelly KA, Rice MA, Miller DB, Klimas NG, Morris M, O'Callaghan JP, Broderick G. A Logic Model of Neuronal-Glial Interaction Suggests Altered Homeostatic Regulation in the Perpetuation of Neuroinflammation. Front Cell Neurosci 2018; 12:336. [PMID: 30374291 PMCID: PMC6196274 DOI: 10.3389/fncel.2018.00336] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 09/12/2018] [Indexed: 11/21/2022] Open
Abstract
Aberrant inflammatory signaling between neuronal and glial cells can develop into a persistent sickness behavior-related disorders, negatively impacting learning, memory, and neurogenesis. While there is an abundance of literature describing these interactions, there still lacks a comprehensive mathematical model describing the complex feed-forward and feedback mechanisms of neural-glial interaction. Here we compile molecular and cellular signaling information from various studies and reviews in the literature to create a logically-consistent, theoretical model of neural-glial interaction in the brain to explore the role of neuron-glia homeostatic regulation in the perpetuation of neuroinflammation. Logic rules are applied to this connectivity diagram to predict the system's homeostatic behavior. We validate our model predicted homeostatic profiles against RNAseq gene expression profiles in a mouse model of stress primed neuroinflammation. A meta-analysis was used to calculate the significance of similarity between the inflammatory profiles of mice exposed to diisopropyl fluorophostphate (DFP) [with and without prior priming by the glucocorticoid stress hormone corticosterone (CORT)], with the equilibrium states predicted by the model, and to provide estimates of the degree of the neuroinflammatory response. Beyond normal homeostatic regulation, our model predicts an alternate self-perpetuating condition consistent with chronic neuroinflammation. RNAseq gene expression profiles from the cortex of mice exposed to DFP and CORT+DFP align with this predicted state of neuroinflammation, whereas the alignment to CORT alone was negligible. Simulations of putative treatment strategies post-exposure were shown to be theoretically capable of returning the system to a state of typically healthy regulation with broad-acting anti-inflammatory agents showing the highest probability of success. The results support a role for the brain's own homeostatic drive in perpetuating the chronic neuroinflammation associated with exposure to the organophosphate DFP, with and without CORT priming. The deviation of illness profiles from exact model predictions suggests the presence of additional factors or of lasting changes to the brain's regulatory circuitry specific to each exposure.
Collapse
Affiliation(s)
- Travis J A Craddock
- Department of Psychology & Neuroscience, Nova Southeastern University, Ft. Lauderdale, FL, United States.,Institute for Neuro-Immune Medicine, Nova Southeastern University, Ft. Lauderdale, FL, United States.,Department of Computer Science, Nova Southeastern University, Ft. Lauderdale, FL, United States.,Department of Clinical Immunology, Nova Southeastern University, Ft. Lauderdale, FL, United States
| | - Lindsay T Michalovicz
- Health Effects Laboratory Division, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Morgantown, WV, United States
| | - Kimberly A Kelly
- Health Effects Laboratory Division, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Morgantown, WV, United States
| | - Mark A Rice
- Institute for Neuro-Immune Medicine, Nova Southeastern University, Ft. Lauderdale, FL, United States
| | - Diane B Miller
- Health Effects Laboratory Division, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Morgantown, WV, United States
| | - Nancy G Klimas
- Institute for Neuro-Immune Medicine, Nova Southeastern University, Ft. Lauderdale, FL, United States.,Department of Clinical Immunology, Nova Southeastern University, Ft. Lauderdale, FL, United States.,Miami Veterans Affairs Medical Center, Miami, FL, United States
| | - Mariana Morris
- Institute for Neuro-Immune Medicine, Nova Southeastern University, Ft. Lauderdale, FL, United States.,Department of Clinical Immunology, Nova Southeastern University, Ft. Lauderdale, FL, United States
| | - James P O'Callaghan
- Health Effects Laboratory Division, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Morgantown, WV, United States
| | - Gordon Broderick
- Department of Psychology & Neuroscience, Nova Southeastern University, Ft. Lauderdale, FL, United States.,Institute for Neuro-Immune Medicine, Nova Southeastern University, Ft. Lauderdale, FL, United States.,Center for Clinical Systems Biology, Rochester General Hospital, Rochester, NY, United States
| |
Collapse
|
7
|
Miller D, Shaerzadeh F, Phan L, Sharif N, Gamble-George J, McLaughlin J, Streit WJ, Khoshbouei H. HIV-1 Tat regulation of dopamine transmission and microglial reactivity is brain region specific. Glia 2018; 66:1915-1928. [PMID: 29733459 PMCID: PMC6185750 DOI: 10.1002/glia.23447] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 04/08/2018] [Accepted: 04/10/2018] [Indexed: 12/14/2022]
Abstract
The transactivator of transcription protein, HIV-1 Tat, is linked to neuroAIDS, where degeneration of dopamine neurons occurs. Using a mouse model expressing GFAP-driven Tat protein under doxycycline (Dox) regulation, we investigated microglial-neuronal interactions in the rostral substantia nigra pars compacta (SNc). Immunohistochemistry for microglia and tyrosine hydroxylase (TH) showed that the ratio of microglia to dopamine neurons is smaller in the SNc than in the ventral tegmental area (VTA) and that this difference is maintained following 7-day Dox exposure in wild type animals. Administration of Dox to wild types had no effect on microglial densities. In addressing the sensitivity of neurons to potentially adverse effects of HIV-1 Tat, we found that HIV-1 Tat exposure in vivo selectively decreased TH immunoreactivity in the SNc but not in the VTA, while levels of TH mRNA in the SNc remained unchanged. HIV-1 Tat induction in vivo did not alter the total number of neurons in these brain regions. Application of Tat (5 ng) into dopamine neurons with whole-cell patch pipette decreased spontaneous firing activity. Tat induction also produced a decline in microglial cell numbers, but no microglial activation. Thus, disappearance of dopaminergic phenotype is due to a loss of TH immunoreactivity rather than to neuronal death, which would have triggered microglial activation. We conclude that adverse effects of HIV-1 Tat produce a hypodopamine state by decreasing TH immunoreactivity and firing activity of dopamine neurons. Reduced microglial numbers after Tat exposure in vivo suggest impaired microglial functions and altered bidirectional interactions between dopamine neurons and microglia.
Collapse
Affiliation(s)
- Douglas Miller
- Department of Neuroscience, University of Florida College of Medicine and McKnight Brain Institute, Gainesville, FL 32610
| | - Fatemeh Shaerzadeh
- Department of Neuroscience, University of Florida College of Medicine and McKnight Brain Institute, Gainesville, FL 32610
| | - Leah Phan
- Department of Neuroscience, University of Florida College of Medicine and McKnight Brain Institute, Gainesville, FL 32610
| | - Nesrin Sharif
- Department of Neuroscience, University of Florida College of Medicine and McKnight Brain Institute, Gainesville, FL 32610
| | - Joyonna Gamble-George
- Department of Neuroscience, University of Florida College of Medicine and McKnight Brain Institute, Gainesville, FL 32610
| | - Jay McLaughlin
- Department of Pharmacodynamics, University of Florida College of Pharmacy, Gainesville, FL 32610
| | - Wolfgang J. Streit
- Department of Neuroscience, University of Florida College of Medicine and McKnight Brain Institute, Gainesville, FL 32610
| | - Habibeh Khoshbouei
- Department of Neuroscience, University of Florida College of Medicine and McKnight Brain Institute, Gainesville, FL 32610
| |
Collapse
|
8
|
Ianov L, De Both M, Chawla MK, Rani A, Kennedy AJ, Piras I, Day JJ, Siniard A, Kumar A, Sweatt JD, Barnes CA, Huentelman MJ, Foster TC. Hippocampal Transcriptomic Profiles: Subfield Vulnerability to Age and Cognitive Impairment. Front Aging Neurosci 2017; 9:383. [PMID: 29276487 PMCID: PMC5727020 DOI: 10.3389/fnagi.2017.00383] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 11/07/2017] [Indexed: 01/11/2023] Open
Abstract
The current study employed next-generation RNA sequencing to examine gene expression differences related to brain aging, cognitive decline, and hippocampal subfields. Young and aged rats were trained on a spatial episodic memory task. Hippocampal regions CA1, CA3, and the dentate gyrus were isolated. Poly-A mRNA was examined using two different sequencing platforms, Illumina, and Ion Proton. The Illumina platform was used to generate seed lists of genes that were statistically differentially expressed across regions, ages, or in association with cognitive function. The gene lists were then retested using the data from the Ion Proton platform. The results indicate hippocampal subfield differences in gene expression and point to regional differences in vulnerability to aging. Aging was associated with increased expression of immune response-related genes, particularly in the dentate gyrus. For the memory task, impaired performance of aged animals was linked to the regulation of Ca2+ and synaptic function in region CA1. Finally, we provide a transcriptomic characterization of the three subfields regardless of age or cognitive status, highlighting and confirming a correspondence between cytoarchitectural boundaries and molecular profiling.
Collapse
Affiliation(s)
- Lara Ianov
- Departments of Neuroscience and Genetics and Genomics Program, Evelyn F. and William L. McKnight Brain Institute, University of Florida, Gainesville, FL, United States.,Civitan International Research Center, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Matt De Both
- Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, United States
| | - Monica K Chawla
- Evelyn F. McKnight Brain Institute, University of Arizona, Tucson, AZ, United States
| | - Asha Rani
- Departments of Neuroscience and Genetics and Genomics Program, Evelyn F. and William L. McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Andrew J Kennedy
- Evelyn F. McKnight Brain Institute, University of Alabama, Birmingham, AL, United States
| | - Ignazio Piras
- Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, United States
| | - Jeremy J Day
- Evelyn F. McKnight Brain Institute, University of Alabama, Birmingham, AL, United States
| | - Ashley Siniard
- Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, United States
| | - Ashok Kumar
- Departments of Neuroscience and Genetics and Genomics Program, Evelyn F. and William L. McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - J David Sweatt
- Evelyn F. McKnight Brain Institute, University of Alabama, Birmingham, AL, United States.,Department of Pharmacology, Vanderbilt University, Nashville, TN, United States
| | - Carol A Barnes
- Evelyn F. McKnight Brain Institute, University of Arizona, Tucson, AZ, United States.,Departments of Psychology, Neurology and Neuroscience, University of Arizona, Tucson, AZ, United States
| | - Matthew J Huentelman
- Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, United States.,Evelyn F. McKnight Brain Institute, University of Arizona, Tucson, AZ, United States
| | - Thomas C Foster
- Departments of Neuroscience and Genetics and Genomics Program, Evelyn F. and William L. McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| |
Collapse
|
9
|
Sasaki A. Microglia and brain macrophages: An update. Neuropathology 2016; 37:452-464. [DOI: 10.1111/neup.12354] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 10/16/2016] [Indexed: 12/26/2022]
Affiliation(s)
- Atsushi Sasaki
- Department of Pathology; Saitama Medical University; Saitama Japan
| |
Collapse
|
10
|
Streit WJ, Xue QS. Microglia in dementia with Lewy bodies. Brain Behav Immun 2016; 55:191-201. [PMID: 26518296 DOI: 10.1016/j.bbi.2015.10.012] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 10/20/2015] [Accepted: 10/22/2015] [Indexed: 11/27/2022] Open
Abstract
Microglial activation (neuroinflammation) is often cited as a pathogenic factor in the development of neurodegenerative diseases. However, there are significant caveats associated with the idea that inflammation directly causes either α-synuclein pathology or neurofibrillary degeneration (NFD). We have performed immunohistochemical studies on microglial cells in five cases of dementia with Lewy bodies (DLB), median age 87, and nine cases of non-demented (ND) controls, median age 74, using tissue samples from the temporal lobe and the superior frontal gyrus. Three different antibodies known to label microglia and macrophages were employed: iba1, anti-CD68, and anti-ferritin. All DLB cases showed both α-synuclein pathology (Lewy bodies and neurites) and NFD ranging from Braak stage II to IV. In contrast, all controls were devoid of α-synuclein pathology but did show NFD ranging from Braak stage I to III. Using iba1 labeling, our current results show a notable absence of activated microglia in all cases with the exception of two controls that showed small focal areas of microglial activation and macrophage formation. Both iba1 and ferritin antibodies revealed a mixture of ramified and dystrophic microglial cells throughout the regions examined, and there were no measurable differences in the prevalence of dystrophic microglial cells between DLB and controls. Double-labeling for α-synuclein and iba1-positive microglia showed that cortical Lewy bodies were surrounded by both ramified and dystrophic microglial cells. We found an increase in CD68 expression in DLB cases relative to controls. Since microglial dystrophy has been linked to NFD and since it did not appear to be worse in DLB cases over controls, our findings support the idea that the additional Lewy body pathology in DLB is not the result of intensified microglial dystrophy. CD68 is likely associated with lipofuscin deposits in microglial cells which may be increased in DLB cases because of impaired proteostasis. Overall, we conclude that neurodegenerative changes in DLB are unlikely to result directly from activated microglia but rather from dysfunctional ones.
Collapse
Affiliation(s)
- Wolfgang J Streit
- Department of Neuroscience, University of Florida College of Medicine and McKnight Brain Institute, Gainesville, FL 32610, USA.
| | - Qing-Shan Xue
- Department of Neuroscience, University of Florida College of Medicine and McKnight Brain Institute, Gainesville, FL 32610, USA
| |
Collapse
|
11
|
Gamba P, Testa G, Gargiulo S, Staurenghi E, Poli G, Leonarduzzi G. Oxidized cholesterol as the driving force behind the development of Alzheimer's disease. Front Aging Neurosci 2015; 7:119. [PMID: 26150787 PMCID: PMC4473000 DOI: 10.3389/fnagi.2015.00119] [Citation(s) in RCA: 120] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 06/03/2015] [Indexed: 12/21/2022] Open
Abstract
Alzheimer’s disease (AD), the most common neurodegenerative disorder associated with dementia, is typified by the pathological accumulation of amyloid Aβ peptides and neurofibrillary tangles (NFT) within the brain. Considerable evidence indicates that many events contribute to AD progression, including oxidative stress, inflammation, and altered cholesterol metabolism. The brain’s high lipid content makes it particularly vulnerable to oxidative species, with the consequent enhancement of lipid peroxidation and cholesterol oxidation, and the subsequent formation of end products, mainly 4-hydroxynonenal and oxysterols, respectively from the two processes. The chronic inflammatory events observed in the AD brain include activation of microglia and astrocytes, together with enhancement of inflammatory molecule and free radical release. Along with glial cells, neurons themselves have been found to contribute to neuroinflammation in the AD brain, by serving as sources of inflammatory mediators. Oxidative stress is intimately associated with neuroinflammation, and a vicious circle has been found to connect oxidative stress and inflammation in AD. Alongside oxidative stress and inflammation, altered cholesterol metabolism and hypercholesterolemia also significantly contribute to neuronal damage and to progression of AD. Increasing evidence is now consolidating the hypothesis that oxidized cholesterol is the driving force behind the development of AD, and that oxysterols are the link connecting the disease to altered cholesterol metabolism in the brain and hypercholesterolemia; this is because of the ability of oxysterols, unlike cholesterol, to cross the blood brain barrier (BBB). The key role of oxysterols in AD pathogenesis has been strongly supported by research pointing to their involvement in modulating neuroinflammation, Aβ accumulation, and cell death. This review highlights the key role played by cholesterol and oxysterols in the brain in AD pathogenesis.
Collapse
Affiliation(s)
- Paola Gamba
- Department of Clinical and Biological Sciences, School of Medicine, University of Turin Orbassano, Torino, Italy
| | - Gabriella Testa
- Department of Clinical and Biological Sciences, School of Medicine, University of Turin Orbassano, Torino, Italy
| | - Simona Gargiulo
- Department of Clinical and Biological Sciences, School of Medicine, University of Turin Orbassano, Torino, Italy
| | - Erica Staurenghi
- Department of Clinical and Biological Sciences, School of Medicine, University of Turin Orbassano, Torino, Italy
| | - Giuseppe Poli
- Department of Clinical and Biological Sciences, School of Medicine, University of Turin Orbassano, Torino, Italy
| | - Gabriella Leonarduzzi
- Department of Clinical and Biological Sciences, School of Medicine, University of Turin Orbassano, Torino, Italy
| |
Collapse
|
12
|
Streit WJ, Xue QS, Tischer J, Bechmann I. Microglial pathology. Acta Neuropathol Commun 2014; 2:142. [PMID: 25257319 PMCID: PMC4180960 DOI: 10.1186/s40478-014-0142-6] [Citation(s) in RCA: 228] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 09/11/2014] [Indexed: 02/06/2023] Open
Abstract
This paper summarizes pathological changes that affect microglial cells in the human brain during aging and in aging-related neurodegenerative diseases, primarily Alzheimer’s disease (AD). It also provides examples of microglial changes that have been observed in laboratory animals during aging and in some experimentally induced lesions and disease models. Dissimilarities and similarities between humans and rodents are discussed in an attempt to generate a current understanding of microglial pathology and its significance during aging and in the pathogenesis of Alzheimer dementia (AD). The identification of dystrophic (senescent) microglia has created an ostensible conflict with prior work claiming a role for activated microglia and neuroinflammation during normal aging and in AD, and this has raised a basic question: does the brain’s immune system become hyperactive (inflamed) or does it become weakened (senescent) in elderly and demented people, and what is the impact on neuronal function and cognition? Here we strive to reconcile these seemingly contradictory notions by arguing that both low-grade neuroinflammation and microglial senescence are the result of aging-associated free radical injury. Both processes are damaging for microglia as they synergistically exhaust this essential cell population to the point where the brain’s immune system is effete and unable to support neuronal function.
Collapse
|
13
|
Filiou MD, Arefin AS, Moscato P, Graeber MB. 'Neuroinflammation' differs categorically from inflammation: transcriptomes of Alzheimer's disease, Parkinson's disease, schizophrenia and inflammatory diseases compared. Neurogenetics 2014; 15:201-12. [PMID: 24928144 DOI: 10.1007/s10048-014-0409-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Accepted: 06/02/2014] [Indexed: 12/30/2022]
Abstract
'Neuroinflammation' has become a widely applied term in the basic and clinical neurosciences but there is no generally accepted neuropathological tissue correlate. Inflammation, which is characterized by the presence of perivascular infiltrates of cells of the adaptive immune system, is indeed seen in the central nervous system (CNS) under certain conditions. Authors who refer to microglial activation as neuroinflammation confuse this issue because autoimmune neuroinflammation serves as a synonym for multiple sclerosis, the prototypical inflammatory disease of the CNS. We have asked the question whether a data-driven, unbiased in silico approach may help to clarify the nomenclatorial confusion. Specifically, we have examined whether unsupervised analysis of microarray data obtained from human cerebral cortex of Alzheimer's, Parkinson's and schizophrenia patients would reveal a degree of relatedness between these diseases and recognized inflammatory conditions including multiple sclerosis. Our results using two different data analysis methods provide strong evidence against this hypothesis demonstrating that very different sets of genes are involved. Consequently, the designations inflammation and neuroinflammation are not interchangeable. They represent different categories not only at the histophenotypic but also at the transcriptomic level. Therefore, non-autoimmune neuroinflammation remains a term in need of definition.
Collapse
Affiliation(s)
- Michaela D Filiou
- Max Planck Institute of Psychiatry, Kraepelinstraße 2, 80804, Munich, Germany
| | | | | | | |
Collapse
|
14
|
Streit WJ, Xue QS. Human CNS immune senescence and neurodegeneration. Curr Opin Immunol 2014; 29:93-6. [PMID: 24908174 DOI: 10.1016/j.coi.2014.05.005] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 05/10/2014] [Accepted: 05/13/2014] [Indexed: 02/07/2023]
Abstract
Microglial cells comprising the brain's immune system are essential for ensuring neuroprotection in the normal and pathological CNS. On the basis of histopathological observations in human brain, we believe that the ability of microglia to provide neuroprotection deteriorates as our brains get older and that such CNS immune senescence is a major factor contributing to the development of aging-related neurodegenerative diseases, notably Alzheimer's disease. The idea is consistent with the fact that immune senescence occurs naturally in the periphery, rendering the elderly people more susceptible to infections and cancers. There is an analogous situation in the brain, except that here the main impact comes down to diminished neuroprotection and resultant neurodegeneration.
Collapse
Affiliation(s)
- Wolfgang J Streit
- Department of Neuroscience, University of Florida College of Medicine and McKnight Brain Institute, Gainesville, FL 32610, USA.
| | - Qing-Shan Xue
- Department of Neuroscience, University of Florida College of Medicine and McKnight Brain Institute, Gainesville, FL 32610, USA
| |
Collapse
|
15
|
Ascaso FJ, Cruz N, Modrego PJ, Lopez-Anton R, Santabárbara J, Pascual LF, Lobo A, Cristóbal JA. Retinal alterations in mild cognitive impairment and Alzheimer's disease: an optical coherence tomography study. J Neurol 2014; 261:1522-30. [PMID: 24846203 DOI: 10.1007/s00415-014-7374-z] [Citation(s) in RCA: 128] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 05/12/2014] [Accepted: 05/13/2014] [Indexed: 01/16/2023]
Abstract
Retinal nerve fiber layer thickness (RNFL) measured by means of Optical Coherence Tomography (OCT) has been used as a marker not only of ophthalmologic diseases but also of neurodegenerative diseases such as Alzheimer's disease (AD) and mild cognitive impairment (MCI). The purpose of this work was to demonstrate that patients with amnestic MCI show an intermediate RNFL thickness between normality and AD, and a macular volume and thickness as well. In a cross-sectional study we consecutively recruited 18 patients with AD, 21 with MCI, and 41 healthy controls. OCT was performed in all of them to measure circumpapillary RNFL thickness in µm, as well as macular volume and thickness. In the analysis of variance we saw that RNFL was thinner in MCI patients compared with controls, and it was also thinner in AD patients compared with MCI patients and controls. With regard to the macular measurements in mm(3), MCI patients had the greatest macular volume in comparison with AD patients and controls. In turn the controls had greater macular volume than AD patients. The decreased RNFL thickness in MCI and AD patients suggests loss of retinal neurons and their axons. The increased thickness and macular volume have never been reported before in aMCI. This finding could be explained by inflammation and/or gliosis in early stages of AD. OCT could be a useful marker of AD for early detection and monitoring progression.
Collapse
Affiliation(s)
- Francisco J Ascaso
- Department of Ophthalmology, Hospital Clínico Universitario "Lozano Blesa", Zaragoza, Spain
| | | | | | | | | | | | | | | |
Collapse
|
16
|
Tryps and trips: cell trafficking across the 100-year-old blood-brain barrier. Trends Neurosci 2014; 37:325-33. [PMID: 24780507 PMCID: PMC4045197 DOI: 10.1016/j.tins.2014.03.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Revised: 03/27/2014] [Accepted: 03/28/2014] [Indexed: 01/03/2023]
Abstract
The blood–brain barrier (BBB) was discovered one century ago by the use of trypan dyes. The discovery initiated the targeted brain delivery of drugs. Trypan dyes were developed to kill African trypanosomes that cause sleeping sickness. Trypanosomes disclose cell trafficking in and out of the BBB. Disturbed gating at the BBB may cause neurodegeneration.
One hundred years ago, Edwin E. Goldmann discovered the blood–brain barrier (BBB) using trypan dyes. These dyes were developed and named by Paul Ehrlich during his search for drugs to kill African trypanosomes (extracellular parasites that cause sleeping sickness) while sparing host cells. For Ehrlich, this was the first strategy based on the ‘chemotherapy’ concept he had introduced. The discovery of the BBB revealed, however, the difficulties in drug delivery to the brain. Mechanisms by which parasites enter, dwell, and exit the brain currently provide novel views on cell trafficking across the BBB. These mechanisms also highlight the role of pericytes and endocytosis regulation in BBB functioning and in disrupted BBB gating, which may be involved in the pathogenesis of neurodegeneration.
Collapse
|