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Lorenzini L, Zanella L, Sannia M, Baldassarro VA, Moretti M, Cescatti M, Quadalti C, Baldi S, Bartolucci G, Di Gloria L, Ramazzotti M, Clavenzani P, Costanzini A, De Giorgio R, Amedei A, Calzà L, Giardino L. Experimental colitis in young Tg2576 mice accelerates the onset of an Alzheimer's-like clinical phenotype. Alzheimers Res Ther 2024; 16:116. [PMID: 38773640 PMCID: PMC11110243 DOI: 10.1186/s13195-024-01471-2] [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: 02/14/2024] [Accepted: 05/01/2024] [Indexed: 05/24/2024]
Abstract
Systemic inflammation and neuroinflammation affect the natural course of the sporadic form of Alzheimer's disease (AD), as supported by epidemiological and preclinical data, and several epidemiological studies indicate a higher prevalence of AD in patients with inflammatory bowel disease. In this study, we explored whether colitis induced by dextran sulfate sodium (DSS) in young, presymptomatic/preplaque mice worsens and/or anticipates age-dependent cognitive impairment in Tg2576, a widely used mouse model of AD. We demonstrated that DSS colitis induced in young Tg2576 mice anticipates the onset age of learning and memory deficit in the Morris water maze test. To explore potential mechanisms behind the acceleration of cognitive decline in Tg2576 mice by DSS colitis, we focused on gut microbiota, systemic inflammation and neuroinflammation markers. We observed a Firmicutes/Bacteroidetes ratio change in Tg2576 DSS animals comparable to that of elderly Tg2576 mice, suggesting accelerated microbiota aging in Tg2576 DSS mice, a change not observed in C57BL6 DSS mice. We also observed substantial differences between Tg2576 and WT mice in several inflammation and neuroinflammation-related parameters as early as 3 months of age, well before plaque deposition, a picture which evolved rapidly (between 3 and 5.5 months of age) in contrast to Tg2576 and WT littermates not treated with DSS. In detail, following induction of DSS colitis, WT and Tg2576 mice exhibited contrasting features in the expression level of inflammation-evoked astrocyte-associated genes in the hippocampus. No changes in microglial features occurred in the hippocampus between the experimental groups, whereas a reduced glial fibrillary acidic protein immunoreactivity was observed in Tg2576 vs. WT mice. This finding may reflect an atrophic, "loss-of-function" profile, further exacerbated by DSS where a decreased of GFAP mRNA expression level was detected. In conclusion, we suggest that as-yet unidentified peripheral mediators evoked by DSS colitis and involving the gut-brain axis emphasize an astrocyte "loss-of-function" profile present in young Tg2576 mice, leading to impaired synaptic morphological and functional integrity as a very early sign of AD.
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Affiliation(s)
- Luca Lorenzini
- Department of Veterinary Medical Sciences (DIMEVET), University of Bologna, Bologna, Italy
| | - Lorenzo Zanella
- Department of Veterinary Medical Sciences (DIMEVET), University of Bologna, Bologna, Italy
| | | | | | - Marzia Moretti
- Department of Veterinary Medical Sciences (DIMEVET), University of Bologna, Bologna, Italy
| | | | - Corinne Quadalti
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Via Tolara di Sopra 41/E, Bologna, 40064, Ozzano Emilia, Italy
| | - Simone Baldi
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Gianluca Bartolucci
- Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, Florence, Italy
| | - Leandro Di Gloria
- Department of Biomedical, Experimental and Clinical Sciences "Mario Serio", University of Florence, Florence, Italy
| | - Matteo Ramazzotti
- Department of Biomedical, Experimental and Clinical Sciences "Mario Serio", University of Florence, Florence, Italy
| | - Paolo Clavenzani
- Department of Veterinary Medical Sciences (DIMEVET), University of Bologna, Bologna, Italy
| | - Anna Costanzini
- Department of Translational Medicine, University of Ferrara, Ferrara, Italy
| | - Roberto De Giorgio
- Department of Translational Medicine, University of Ferrara, Ferrara, Italy
| | - Amedeo Amedei
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Laura Calzà
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Via Tolara di Sopra 41/E, Bologna, 40064, Ozzano Emilia, Italy.
| | - Luciana Giardino
- Department of Veterinary Medical Sciences (DIMEVET), University of Bologna, Bologna, Italy
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2
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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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Zarate SM, Huntington TE, Bagher P, Srinivasan R. Aging reduces calreticulin expression and alters spontaneous calcium signals in astrocytic endfeet of the mouse dorsolateral striatum. NPJ AGING 2023; 9:5. [PMID: 37002232 PMCID: PMC10066375 DOI: 10.1038/s41514-023-00102-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Accepted: 03/15/2023] [Indexed: 04/03/2023]
Abstract
Aging-related impairment of the blood brain barrier (BBB) and neurovascular unit (NVU) increases the risk for neurodegeneration. Among various cells that participate in BBB and NVU function, calcium signals in astrocytic endfeet are crucial for maintaining BBB and NVU integrity. To assess if aging is associated with altered calcium signals within astrocytic endfeet of the dorsolateral striatum (DLS), we expressed GCaMP6f in DLS astrocytes of young (3-4 months), middle-aged (12-15 months) and aging (20-30 months) mice. Compared to endfeet in young mice, DLS endfeet in aging mice demonstrated decreased calreticulin expression, and alterations to both spontaneous membrane-associated and mitochondrial calcium signals. While young mice required both extracellular and endoplasmic reticulum calcium sources for endfoot signals, middle-aged and aging mice showed heavy dependence on endoplasmic reticulum calcium. Thus, astrocytic endfeet show significant changes in calcium buffering and sources throughout the lifespan, which is important for understanding mechanisms by which aging impairs the BBB and NVU.
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Affiliation(s)
- Sara M Zarate
- Department of Neuroscience & Experimental Therapeutics, Texas A&M University School of Medicine, 8447 Riverside Pkwy, Bryan, TX, 77807, USA
| | - Taylor E Huntington
- Department of Neuroscience & Experimental Therapeutics, Texas A&M University School of Medicine, 8447 Riverside Pkwy, Bryan, TX, 77807, USA
- Texas A&M Institute for Neuroscience (TAMIN), Texas A&M University, College Station, TX, 77843, USA
| | - Pooneh Bagher
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Rahul Srinivasan
- Department of Neuroscience & Experimental Therapeutics, Texas A&M University School of Medicine, 8447 Riverside Pkwy, Bryan, TX, 77807, USA.
- Texas A&M Institute for Neuroscience (TAMIN), Texas A&M University, College Station, TX, 77843, USA.
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Vielee ST, Wise JP. Among Gerontogens, Heavy Metals Are a Class of Their Own: A Review of the Evidence for Cellular Senescence. Brain Sci 2023; 13:500. [PMID: 36979310 PMCID: PMC10046019 DOI: 10.3390/brainsci13030500] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 03/10/2023] [Accepted: 03/13/2023] [Indexed: 03/18/2023] Open
Abstract
Advancements in modern medicine have improved the quality of life across the globe and increased the average lifespan of our population by multiple decades. Current estimates predict by 2030, 12% of the global population will reach a geriatric age and live another 3-4 decades. This swelling geriatric population will place critical stress on healthcare infrastructures due to accompanying increases in age-related diseases and comorbidities. While much research focused on long-lived individuals seeks to answer questions regarding how to age healthier, there is a deficit in research investigating what aspects of our lives accelerate or exacerbate aging. In particular, heavy metals are recognized as a significant threat to human health with links to a plethora of age-related diseases, and have widespread human exposures from occupational, medical, or environmental settings. We believe heavy metals ought to be classified as a class of gerontogens (i.e., chemicals that accelerate biological aging in cells and tissues). Gerontogens may be best studied through their effects on the "Hallmarks of Aging", nine physiological hallmarks demonstrated to occur in aged cells, tissues, and bodies. Evidence suggests that cellular senescence-a permanent growth arrest in cells-is one of the most pertinent hallmarks of aging and is a useful indicator of aging in tissues. Here, we discuss the roles of heavy metals in brain aging. We briefly discuss brain aging in general, then expand upon observations for heavy metals contributing to age-related neurodegenerative disorders. We particularly emphasize the roles and observations of cellular senescence in neurodegenerative diseases. Finally, we discuss the observations for heavy metals inducing cellular senescence. The glaring lack of knowledge about gerontogens and gerontogenic mechanisms necessitates greater research in the field, especially in the context of the global aging crisis.
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Affiliation(s)
- Samuel T. Vielee
- Pediatrics Research Institute, Department of Pediatrics, University of Louisville, Louisville, KY 40202, USA
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY 40202, USA
| | - John P. Wise
- Pediatrics Research Institute, Department of Pediatrics, University of Louisville, Louisville, KY 40202, USA
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY 40202, USA
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5
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Martinez-Galan JR, Garcia-Belando M, Cabanes-Sanchis JJ, Caminos E. Pre- and postsynaptic alterations in the visual cortex of the P23H-1 retinal degeneration rat model. Front Neuroanat 2022; 16:1000085. [PMID: 36312296 PMCID: PMC9608761 DOI: 10.3389/fnana.2022.1000085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 09/29/2022] [Indexed: 11/24/2022] Open
Abstract
P23H rats express a variant of rhodopsin with a mutation that leads to loss of visual function with similar properties as human autosomal dominant retinitis pigmentosa (RP). The advances made in different therapeutic strategies to recover visual system functionality reveal the need to know whether progressive retina degeneration affects the visual cortex structure. Here we are interested in detecting cortical alterations in young rats with moderate retinal degeneration, and in adulthood when degeneration is severer. For this purpose, we studied the synaptic architecture of the primary visual cortex (V1) by analyzing a series of pre- and postsynaptic elements related to excitatory glutamatergic transmission. Visual cortices from control Sprague Dawley (SD) and P23H rats at postnatal days 30 (P30) and P230 were used to evaluate the distribution of vesicular glutamate transporters VGLUT1 and VGLUT2 by immunofluorescence, and to analyze the expression of postsynaptic density protein-95 (PSD-95) by Western blot. The amount and dendritic spine distribution along the apical shafts of the layer V pyramidal neurons, stained by the Golgi-Cox method, were also studied. We observed that at P30, RP does not significantly affect any of the studied markers and structures, which suggests in young P23H rats that visual cortex connectivity seems preserved. However, in adult rats, although VGLUT1 immunoreactivity and PSD-95 expression were similar between both groups, a narrower and stronger VGLUT2-immunoreactive band in layer IV was observed in the P23H rats. Furthermore, RP significantly decreased the density of dendritic spines and altered their distribution along the apical shafts of pyramidal neurons, which remained in a more immature state compared to the P230 SD rats. Our results indicate that the most notable changes in the visual cortex structure take place after a prolonged retinal degeneration period that affected the presynaptic thalamocortical VGLUT2-immunoreactive terminals and postsynaptic dendritic spines from layer V pyramidal cells. Although plasticity is more limited at these ages, future studies will determine how reversible these changes are and to what extent they can affect the visual system's functionality.
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Affiliation(s)
- Juan R. Martinez-Galan
- Facultad de Medicina, Instituto de Investigación en Discapacidades Neurológicas, Universidad de Castilla-La Mancha, Albacete, Spain
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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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7
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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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De Santis I, Lorenzini L, Moretti M, Martella E, Lucarelli E, Calzà L, Bevilacqua A. Co-Density Distribution Maps for Advanced Molecule Colocalization and Co-Distribution Analysis. SENSORS (BASEL, SWITZERLAND) 2021; 21:6385. [PMID: 34640704 PMCID: PMC8513075 DOI: 10.3390/s21196385] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 09/19/2021] [Accepted: 09/21/2021] [Indexed: 01/19/2023]
Abstract
Cellular and subcellular spatial colocalization of structures and molecules in biological specimens is an important indicator of their co-compartmentalization and interaction. Presently, colocalization in biomedical images is addressed with visual inspection and quantified by co-occurrence and correlation coefficients. However, such measures alone cannot capture the complexity of the interactions, which does not limit itself to signal intensity. On top of the previously developed density distribution maps (DDMs), here, we present a method for advancing current colocalization analysis by introducing co-density distribution maps (cDDMs), which, uniquely, provide information about molecules absolute and relative position and local abundance. We exemplify the benefits of our method by developing cDDMs-integrated pipelines for the analysis of molecules pairs co-distribution in three different real-case image datasets. First, cDDMs are shown to be indicators of colocalization and degree, able to increase the reliability of correlation coefficients currently used to detect the presence of colocalization. In addition, they provide a simultaneously visual and quantitative support, which opens for new investigation paths and biomedical considerations. Finally, thanks to the coDDMaker software we developed, cDDMs become an enabling tool for the quasi real time monitoring of experiments and a potential improvement for a large number of biomedical studies.
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Affiliation(s)
- Ilaria De Santis
- Department of Medical and Surgical Sciences (DIMEC), Alma Mater Studiorum—University of Bologna, I-40138 Bologna, Italy;
- Interdepartmental Center Alma Mater Research Institute on Global Challenges and Climate Change (Alma Climate), Alma Mater Studiorum—University of Bologna, I-40126 Bologna, Italy
| | - Luca Lorenzini
- Department of Veterinary Medical Sciences (DIMEVET), Alma Mater Studiorum—University of Bologna, I-40064 Ozzano Emilia, Italy;
| | - Marzia Moretti
- Iret Foundation, I-40064 Ozzano Emilia, Italy; (M.M.); (L.C.)
| | - Elisa Martella
- Institute of Organic Synthesis and Photoreactivity (ISOF), National Research Council (CNR), I-40129 Bologna, Italy;
| | - Enrico Lucarelli
- Regenerative Therapies in Oncology, IRCCS Istituto Ortopedico Rizzoli, I-40136 Bologna, Italy;
| | - Laura Calzà
- Iret Foundation, I-40064 Ozzano Emilia, Italy; (M.M.); (L.C.)
- Department of Pharmacy and BioTechnology (FaBiT), Alma Mater Studiorum—University of Bologna, I-40127 Bologna, Italy
| | - Alessandro Bevilacqua
- Advanced Research Center on Electronic Systems (ARCES) for Information and Communication Technologies “E. De Castro”, Alma Mater Studiorum—University of Bologna, I-40125 Bologna, Italy
- Department of Computer Science and Engineering (DISI), Alma Mater Studiorum—University of Bologna, I-40136 Bologna, Italy
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9
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Olson CA, Iñiguez AJ, Yang GE, Fang P, Pronovost GN, Jameson KG, Rendon TK, Paramo J, Barlow JT, Ismagilov RF, Hsiao EY. Alterations in the gut microbiota contribute to cognitive impairment induced by the ketogenic diet and hypoxia. Cell Host Microbe 2021; 29:1378-1392.e6. [PMID: 34358434 PMCID: PMC8429275 DOI: 10.1016/j.chom.2021.07.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 05/17/2021] [Accepted: 07/12/2021] [Indexed: 01/16/2023]
Abstract
Many genetic and environmental factors increase susceptibility to cognitive impairment (CI), and the gut microbiome is increasingly implicated. However, the identity of gut microbes associated with CI risk, their effects on CI, and their mechanisms remain unclear. Here, we show that a carbohydrate-restricted (ketogenic) diet potentiates CI induced by intermittent hypoxia in mice and alters the gut microbiota. Depleting the microbiome reduces CI, whereas transplantation of the risk-associated microbiome or monocolonization with Bilophila wadsworthia confers CI in mice fed a standard diet. B. wadsworthia and the risk-associated microbiome disrupt hippocampal synaptic plasticity, neurogenesis, and gene expression. The CI is associated with microbiome-dependent increases in intestinal interferon-gamma (IFNg)-producing Th1 cells. Inhibiting Th1 cell development abrogates the adverse effects of both B. wadsworthia and environmental risk factors on CI. Together, these findings identify select gut bacteria that contribute to environmental risk for CI in mice by promoting inflammation and hippocampal dysfunction.
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Affiliation(s)
- Christine A. Olson
- Department of Integrative Biology & Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA,Correspondence to: ,
| | - Alonso J. Iñiguez
- Department of Integrative Biology & Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Grace E. Yang
- Department of Integrative Biology & Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Ping Fang
- Department of Integrative Biology & Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Geoffrey N. Pronovost
- Department of Integrative Biology & Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Kelly G. Jameson
- Department of Integrative Biology & Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Tomiko K. Rendon
- Department of Integrative Biology & Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Jorge Paramo
- Department of Integrative Biology & Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Jacob T. Barlow
- Division of Chemistry & Chemical Engineering, California Institute of Technology, Pasadena, CA 91108, USA
| | - Rustem F. Ismagilov
- Division of Chemistry & Chemical Engineering, California Institute of Technology, Pasadena, CA 91108, USA
| | - Elaine Y. Hsiao
- Department of Integrative Biology & Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA,Correspondence to: ,
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Xu X, Wang K, Cao X, Li Z, Zhou Y, Ren J, Liu F. Gut Microbial Metabolite Short-Chain Fatt Acids Partially Reverse Surgery and Anesthesia-Induced Behavior Deficits in C57BL/6J Mice. Front Neurosci 2021; 15:664641. [PMID: 34168535 PMCID: PMC8217457 DOI: 10.3389/fnins.2021.664641] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 04/27/2021] [Indexed: 12/14/2022] Open
Abstract
Accumulating evidence has demonstrated that damages of gut microbiota are strongly associated with central nervous system (CNS) diseases, such as perioperative neurocognitive disorders (PND). The present study investigated the role of gut microbial metabolite short-chain fatty acids (SCFAs) in surgery-induced cognitive deficits and neuroinflammation in the hippocampus. Adult male C57BL/6J mice received either SCFA mixture or saline orally for 4 weeks, and then partial hepatectomy was performed. The fecal supernatant of surgical mice was transplanted to normal mice for 3 weeks. The Morris water maze (MWM) and open-field tests were used to evaluate behavioral performance on postoperative or post-transplantation days 3 and 7. In the MWM test, pretreatment with exogenous SCFAs partially reversed surgery-induced impairments in crossing times and the time spent in the target quadrant on postoperative day 3 (p < 0.05, p < 0.05, respectively). In the open-field test, compared with the surgical mice, exogenous SCFA administration prior to surgery partially improved the locomotor activity (p < 0.05) and anxiety-like behavior (p < 0.05) on postoperative day 3. Surgical trauma and anesthesia enhanced ionized calcium-binding adapter molecule 1 (Iba-1) expression (p < 0.001), increased the levels of interleukin (IL)-1β (p < 0.001) and IL-6 (p < 0.001), and inhibited SCFA production (p < 0.001) on postoperative day 3. The expression of the brain-derived neurotrophic factor (BDNF) was also decreased (p < 0.001). Overall, surgical trauma and anesthesia exacerbated cognitive impairment, enhanced neuroinflammatory responses, and inhibited SCFA production. Pretreatment with SCFAs attenuated these effects partially by reversing microglial overactivation, inhibiting neuroinflammatory responses, and enhancing BDNF expression.
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Affiliation(s)
- Xiaohan Xu
- Department of Anesthesiology, The First Affiliated Hospital of China Medical University, Shenyang, China
| | - Kexin Wang
- Department of Anesthesiology, The First Affiliated Hospital of China Medical University, Shenyang, China
| | - Xuezhao Cao
- Department of Anesthesiology, The First Affiliated Hospital of China Medical University, Shenyang, China
| | - Zhe Li
- Department of Anesthesiology, The First Affiliated Hospital of China Medical University, Shenyang, China
| | - Yongjian Zhou
- Department of Anesthesiology, The First Affiliated Hospital of China Medical University, Shenyang, China
| | - Jiancong Ren
- Department of Thyroid Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Fang Liu
- Department of Neurology, The First Affiliated Hospital of China Medical University, Shenyang, China
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Steinman J, Sun HS, Feng ZP. Microvascular Alterations in Alzheimer's Disease. Front Cell Neurosci 2021; 14:618986. [PMID: 33536876 PMCID: PMC7849053 DOI: 10.3389/fncel.2020.618986] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 12/17/2020] [Indexed: 12/27/2022] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder associated with continual decline in cognition and ability to perform routine functions such as remembering familiar places or understanding speech. For decades, amyloid beta (Aβ) was viewed as the driver of AD, triggering neurodegenerative processes such as inflammation and formation of neurofibrillary tangles (NFTs). This approach has not yielded therapeutics that cure the disease or significant improvements in long-term cognition through removal of plaques and Aβ oligomers. Some researchers propose alternate mechanisms that drive AD or act in conjunction with amyloid to promote neurodegeneration. This review summarizes the status of AD research and examines research directions including and beyond Aβ, such as tau, inflammation, and protein clearance mechanisms. The effect of aging on microvasculature is highlighted, including its contribution to reduced blood flow that impairs cognition. Microvascular alterations observed in AD are outlined, emphasizing imaging studies of capillary malfunction. The review concludes with a discussion of two therapies to protect tissue without directly targeting Aβ for removal: (1) administration of growth factors to promote vascular recovery in AD; (2) inhibiting activity of a calcium-permeable ion channels to reduce microglial activation and restore cerebral vascular function.
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Affiliation(s)
- Joe Steinman
- Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Hong-Shuo Sun
- Department of Physiology, University of Toronto, Toronto, ON, Canada.,Department of Surgery, University of Toronto, Toronto, ON, Canada
| | - Zhong-Ping Feng
- Department of Physiology, University of Toronto, Toronto, ON, Canada
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Du X, Li J, Li M, Yang X, Qi Z, Xu B, Liu W, Xu Z, Deng Y. Research progress on the role of type I vesicular glutamate transporter (VGLUT1) in nervous system diseases. Cell Biosci 2020; 10:26. [PMID: 32158532 PMCID: PMC7057577 DOI: 10.1186/s13578-020-00393-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 02/24/2020] [Indexed: 12/14/2022] Open
Abstract
Glutamate (Glu) is the predominant excitatory neurotransmitter in the central nervous system (CNS). Glutamatergic transmission is critical for controlling neuronal activity. In presynaptic neurons, Glu is stored in synaptic vesicles and released by stimulation. The homeostasis of glutamatergic system is maintained by a set of transporters in the membrane of synaptic vesicles. The family of vesicular Glu transporters in mammals is comprised of three highly homologous proteins: VGLUT1-3. Among them, VGLUT1 accounts for the largest proportion. However, most of the Glu is transported into the synaptic vesicles via the type 1 vesicle Glu transporter (VGLUT1). So, the expression of particular VGLUT1 is largely complementary with limited overlap and so far it is most specific markers for neurons that use Glu as neurotransmitter. Controlling the activity of VGLUT1 could potentially modulate the efficiency of excitatory neuro-transmission and change the filling level of synaptic vesicles. This review summarizes the recent knowledge concerning molecular and functional characteristic of VGLUT1, their development, contribution to a series of central nervous system and peripheral nervous system diseases such as learning and memory disorders, Alzheimer's disease, Parkinson's disease and sensitized nociception or pain pathology et al.
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Affiliation(s)
- Xianchao Du
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, 110122 Liaoning People’s Republic of China
| | - Jiashuo Li
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, 110122 Liaoning People’s Republic of China
| | - Minghui Li
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, 110122 Liaoning People’s Republic of China
| | - Xinxin Yang
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, 110122 Liaoning People’s Republic of China
| | - Zhipeng Qi
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, 110122 Liaoning People’s Republic of China
| | - Bin Xu
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, 110122 Liaoning People’s Republic of China
| | - Wei Liu
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, 110122 Liaoning People’s Republic of China
| | - Zhaofa Xu
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, 110122 Liaoning People’s Republic of China
| | - Yu Deng
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, 110122 Liaoning People’s Republic of China
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Beta secretase 1-dependent amyloid precursor protein processing promotes excessive vascular sprouting through NOTCH3 signalling. Cell Death Dis 2020; 11:98. [PMID: 32029735 PMCID: PMC7005019 DOI: 10.1038/s41419-020-2288-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 01/21/2020] [Accepted: 01/22/2020] [Indexed: 01/18/2023]
Abstract
Amyloid beta peptides (Aβ) proteins play a key role in vascular pathology in Alzheimer’s Disease (AD) including impairment of the blood–brain barrier and aberrant angiogenesis. Although previous work has demonstrated a pro-angiogenic role of Aβ, the exact mechanisms by which amyloid precursor protein (APP) processing and endothelial angiogenic signalling cascades interact in AD remain a largely unsolved problem. Here, we report that increased endothelial sprouting in human-APP transgenic mouse (TgCRND8) tissue is dependent on β-secretase (BACE1) processing of APP. Higher levels of Aβ processing in TgCRND8 tissue coincides with decreased NOTCH3/JAG1 signalling, overproduction of endothelial filopodia and increased numbers of vascular pericytes. Using a novel in vitro approach to study sprouting angiogenesis in TgCRND8 organotypic brain slice cultures (OBSCs), we find that BACE1 inhibition normalises excessive endothelial filopodia formation and restores NOTCH3 signalling. These data present the first evidence for the potential of BACE1 inhibition as an effective therapeutic target for aberrant angiogenesis in AD.
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White Matter and Neuroprotection in Alzheimer's Dementia. Molecules 2020; 25:molecules25030503. [PMID: 31979414 PMCID: PMC7038211 DOI: 10.3390/molecules25030503] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Revised: 01/20/2020] [Accepted: 01/21/2020] [Indexed: 12/12/2022] Open
Abstract
Myelin is the main component of the white matter of the central nervous system (CNS), allowing the proper electrical function of the neurons by ensheathing and insulating the axons. The extensive use of magnetic resonance imaging has highlighted the white matter alterations in Alzheimer’s dementia (AD) and other neurodegenerative diseases, alterations which are early, extended, and regionally selective. Given that the white matter turnover is considerable in the adulthood, and that myelin repair is currently recognized as being the only true reparative capability of the mature CNS, oligodendrocyte precursor cells (OPCs), the cells that differentiate in oligodendrocyte, responsible for myelin formation and repair, are regarded as a potential target for neuroprotection. In this review, several aspects of the OPC biology are reviewed. The histology and functional role of OPCs in the neurovascular-neuroglial unit as described in preclinical and clinical studies on AD is discussed, such as the OPC vulnerability to hypoxia-ischemia, neuroinflammation, and amyloid deposition. Finally, the position of OPCs in drug discovery strategies for dementia is discussed.
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