Microglia changes associated to Alzheimer's disease pathology in aged chimpanzees.
Alzheimer's disease; amyloid beta protein; chimpanzee; microglia; neurofibrillary tangle; neuroinflammation; RRID: AB223647; RRID: AB2313890; RRID: AB2313952; RRID: AB2315150; RRID: AB839504
In Alzheimer's disease (AD), the brain's primary immune cells, microglia, become activated and are found in close apposition to amyloid beta (Abeta) protein plaques and neurofibrillary tangles (NFT). The present study evaluated microglia density and morphology in a large group of aged chimpanzees (n = 20, ages 37-62 years) with varying degrees of AD-like pathology. Using immunohistochemical and stereological techniques, we quantified the density of activated microglia and morphological variants (ramified, intermediate, and amoeboid) in postmortem chimpanzee brain samples from prefrontal cortex, middle temporal gyrus, and hippocampus, areas that show a high degree of AD pathology in humans. Microglia measurements were compared to pathological markers of AD in these cases. Activated microglia were consistently present across brain areas. In the hippocampus, CA3 displayed a higher density than CA1. Abeta42 plaque volume was positively correlated with higher microglial activation and with an intermediate morphology in the hippocampus. Abeta42-positive vessel volume was associated with increased hippocampal microglial activation. Activated microglia density and morphology were not associated with age, sex, pretangle density, NFT density, or tau neuritic cluster density. Aged chimpanzees displayed comparable patterns of activated microglia phenotypes as well as an association of increased microglial activation and morphological changes with Abeta deposition similar to AD patients. In contrast to human AD brains, activated microglia density was not significantly correlated with tau lesions. This evidence suggests that the chimpanzee brain may be relatively preserved during normal aging processes but not entirely protected from neurodegeneration as previously assumed.
Edler Melissa K; Sherwood Chet C; Meindl Richard S; Munger Emily L; Hopkins William D; Ely John J; Erwin Joseph M; Perl Daniel P; Mufson Elliott J; Hof Patrick R; Raghanti Mary Ann
The Journal of comparative neurology
2018
2018-12
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1002/cne.24484" target="_blank" rel="noreferrer noopener">10.1002/cne.24484</a>
Astrocytic changes with aging and Alzheimer's disease-type pathology in chimpanzees.
aging; Alzheimer's disease; astrocytes; cerebral cortex; chimpanzees; hippocampus; prefrontal cortex; RRID: AB2109645; RRID: AB223647; RRID: AB2313952; RRID: AB2314223; stereology
Astrocytes are the main homeostatic cell of the central nervous system. In addition, astrocytes mediate an inflammatory response when reactive to injury or disease known as astrogliosis. Astrogliosis is marked by an increased expression of glial fibrillary acidic protein (GFAP) and cellular hypertrophy. Some degree of astrogliosis is associated with normal aging and degenerative conditions such as Alzheimer's disease (AD) and other dementing illnesses in humans. The recent observation of pathological markers of AD (amyloid plaques and neurofibrillary tangles) in aged chimpanzee brains provided an opportunity to examine the relationships among aging, AD-type pathology, and astrocyte activation in our closest living relatives. Stereologic methods were used to quantify
Munger Emily L; Edler Melissa K; Hopkins William D; Ely John J; Erwin Joseph M; Perl Daniel P; Mufson Elliott J; Hof Patrick R; Sherwood Chet C; Raghanti Mary Ann
The Journal of comparative neurology
2018
2018-12
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1002/cne.24610" target="_blank" rel="noreferrer noopener">10.1002/cne.24610</a>
Altered Neuroinflammation and Behavior after Traumatic Brain Injury in a Mouse Model of Alzheimer's Disease.
Alzheimer Disease/etiology/*metabolism/pathology; Alzheimer's disease; Amyloid beta-Peptides/*metabolism; Animal; Animal/physiology; Animals; Behavior; Blotting; Brain Injuries; Brain/*metabolism/pathology; Disease Models; Enzyme-Linked Immunosorbent Assay; Flow Cytometry; Humans; Immunohistochemistry; Inbred C57BL; Inflammation/*metabolism/pathology; macrophage; Mice; neuroinflammation; Transgenic; traumatic brain injury; Traumatic/complications/*metabolism/*pathology; Western
Traumatic brain injury (TBI) has acute and chronic sequelae, including an increased risk for the development of Alzheimer's disease (AD). TBI-associated neuroinflammation is characterized by activation of brain-resident microglia and infiltration of monocytes; however, recent studies have implicated beta-amyloid as a major manipulator of the inflammatory response. To examine neuroinflammation after TBI and development of AD-like features, these studies examined the effects of TBI in the presence and absence of beta-amyloid. The R1.40 mouse model of cerebral amyloidosis was used, with a focus on time points well before robust AD pathologies. Unexpectedly, in R1.40 mice, the acute neuroinflammatory response to TBI was strikingly muted, with reduced numbers of CNS myeloid cells acquiring a macrophage phenotype and decreased expression of inflammatory cytokines. At chronic time points, macrophage activation substantially declined in non-Tg TBI mice; however, it was relatively unchanged in R1.40 TBI mice. The persistent inflammatory response coincided with significant tissue loss between 3 and 120 days post-injury in R1.40 TBI mice, which was not observed in non-Tg TBI mice. Surprisingly, inflammatory cytokine expression was enhanced in R1.40 mice compared with non-Tg mice, regardless of injury group. Although R1.40 TBI mice demonstrated task-specific deficits in cognition, overall functional recovery was similar to non-Tg TBI mice. These findings suggest that accumulating beta-amyloid leads to an altered post-injury macrophage response at acute and chronic time points. Together, these studies emphasize the role of post-injury neuroinflammation in regulating long-term sequelae after TBI and also support recent studies implicating beta-amyloid as an immunomodulator.
Kokiko-Cochran Olga N; Ransohoff Lena; Veenstra Mike; Lee Sungho; Saber Maha; Sikora Matt; Teknipp Ryan; Xu Guixiang; Bemiller Shane M; Wilson Gina; Crish Samuel; Bhaskar Kiran; Lee Yu-Shang; Ransohoff Richard M; Lamb Bruce T
Journal of neurotrauma
2016
2016-04
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1089/neu.2015.3970" target="_blank" rel="noreferrer noopener">10.1089/neu.2015.3970</a>
Genetically enhancing the expression of chemokine domain of CX3CL1 fails to prevent tau pathology in mouse models of tauopathy.
Alzheimer's disease; Animal; Animals; Antigens; Biological; Calcium Binding Proteins – Metabolism; Calcium-Binding Proteins/metabolism; Cells – Drug Effects; Cells – Metabolism; Cells – Pathology; Chemokine CX3CL1/*genetics/metabolism; Cognition Disorders – Etiology; Cognition Disorders/etiology; CX3CL1; CX3CR1; Cytokines; Cytokines – Metabolism; Cytokines/metabolism; Differentiation/genetics/metabolism; Disease Models; Gene Expression Regulation/drug effects/*genetics; Genes; Genes – Drug Effects; Learning; Lipopolysaccharides; Lipopolysaccharides/toxicity; Maze Learning; Mice; Microfilament Proteins – Metabolism; Microfilament Proteins/metabolism; Microglia; Microglia/drug effects/*metabolism/pathology; Models; Mutation; Mutation/genetics; Nerve Tissue Proteins; Nerve Tissue Proteins – Metabolism; Neurodegenerative Diseases; Neurodegenerative Diseases – Complications; Neurodegenerative Diseases – Pathology; Neuroinflammation; Surface; Surface – Metabolism; Tau; tau Proteins/genetics/metabolism; Tauopathies; Tauopathies/complications/genetics/*pathology; Transgenic
BACKGROUND: Fractalkine (CX3CL1) and its receptor (CX3CR1) play an important role in regulating microglial function. We have previously shown that Cx3cr1 deficiency exacerbated tau pathology and led to cognitive impairment. However, it is still unclear if the chemokine domain of the ligand CX3CL1 is essential in regulating neuronal tau pathology. METHODS: We used transgenic mice lacking endogenous Cx3cl1 (Cx3cl1(-/-)) and expressing only obligatory soluble form (with only chemokine domain) and lacking the mucin stalk of CX3CL1 (referred to as Cx3cl1(105Delta) mice) to assess tau pathology and behavioral function in both lipopolysaccharide (LPS) and genetic (hTau) mouse models of tauopathy. RESULTS: First, increased basal tau levels accompanied microglial activation in Cx3cl1(105Delta) mice compared to control groups. Second, increased CD45(+) and F4/80(+) neuroinflammation and tau phosphorylation were observed in LPS, hTau/Cx3cl1(-/-), and hTau/Cx3cl1(105Delta) mouse models of tau pathology, which correlated with impaired spatial learning. Finally, microglial cell surface expression of CX3CR1 was reduced in Cx3cl1(105Delta) mice, suggesting enhanced fractalkine receptor internalization (mimicking Cx3cr1 deletion), which likely contributes to the elevated tau pathology. CONCLUSIONS: Collectively, our data suggest that overexpression of only chemokine domain of CX3CL1 does not protect against tau pathology.
Bemiller Shane M; Maphis Nicole M; Formica Shane V; Wilson Gina N; Miller Crystal M; Xu Guixiang; Kokiko-Cochran Olga N; Kim Ki-Wook; Jung Steffen; Cannon Judy L; Crish Samuel D; Cardona Astrid E; Lamb Bruce T; Bhaskar Kiran
Journal of neuroinflammation
2018
2018-09
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1186/s12974-018-1310-6" target="_blank" rel="noreferrer noopener">10.1186/s12974-018-1310-6</a>
Pharmacotherapy of Alzheimer's disease: current and future trends.
Humans; Alzheimer's disease; Alzheimer Disease/*drug therapy; anti-inflammatory agents; antioxidants; cholinesterase inhibitors; dementia; Drug Therapy/*methods/*trends; immunotherapy; memantine; multi-targeted drugs; natural products; pharmacotherapy
Alzheimer's disease (AD) and its related dementia has shown an alarming rise in the global population. Although considerable efforts have been made to develop effective therapeutic agents for AD therapy, drug development has not met significant clinical success. Current pharmacotherapy of AD is limited to cholinesterase inhibitors and the N-methyl-D-aspartate antagonist memantine. Considerable research is underway to develop newer agents for the management of AD. Since amyloid-beta (Abeta) has been implicated in AD pathogenesis, the use of beta secretase inhibitors as well as immunotherapy against Abeta has been investigated. A considerable effort has been spent investigating the therapeutic potential of antioxidants and anti-inflammatory agents, several of natural products and dietary origin, in AD treatment. Numerous drug targets have also been investigated for AD treatment and a modest drug pipeline is available. Despite these efforts, drug development for AD has proved extremely difficult and most clinical trials have afforded disappointing results.
Geldenhuys Werner J; Darvesh Altaf S
Expert review of neurotherapeutics
2015
2015-01
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1586/14737175.2015.990884" target="_blank" rel="noreferrer noopener">10.1586/14737175.2015.990884</a>
Shared mechanisms: osteoporosis and Alzheimer's disease?
Alzheimer's disease; dementia; osteoporosis; serotonin; Wnt
Dengler-Crish Christine M; Elefteriou Florent
Aging
2019
2019-02
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.18632/aging.101828" target="_blank" rel="noreferrer noopener">10.18632/aging.101828</a>
Early Evidence of Low Bone Density and Decreased Serotonergic Synthesis in the Dorsal Raphe of a Tauopathy Model of Alzheimer's Disease.
Female; Male; Animals; Mice; *Alzheimer's disease; Body Weight; Body Composition; Age Factors; Body Weight/genetics; Phosphorylation; Bone Density/*physiology; *Alzheimer Disease/complications/genetics/pathology; *bone density; *microtubule-associated protein; *serotonin; *tau proteins; *tauopathies; Body Composition/genetics; Bone Diseases/*etiology; Dorsal Raphe Nucleus/*pathology; Neurons/metabolism/pathology; Serotonin/*metabolism; tau Proteins/*genetics/metabolism; Tauopathies/complications/genetics; Tryptophan Hydroxylase/metabolism; Biological; Models; Inbred C57BL; Animal; Disease Models; Transgenic; Nerve Tissue Proteins; Neurodegenerative Diseases; Animal Studies; Alzheimer's Disease; Bone Density – Physiology; Nerve Tissue Proteins – Metabolism; Neurodegenerative Diseases – Complications; Alzheimer's Disease – Complications; Alzheimer's Disease – Pathology; Bone Diseases – Etiology; Brain Stem – Pathology; Neurons – Metabolism; Neurons – Pathology; Oxidoreductases – Metabolism; Serotonin – Metabolism
Reduced bone mineral density (BMD) and its clinical sequelae, osteoporosis, occur at a much greater rate in patients with Alzheimer's disease (AD), often emerging early in the disease before significant cognitive decline is seen. Reduced BMD translates to increased bone fracture risk, decreased quality of life, and increased mortality for AD patients. However, the mechanism responsible for this observation is unclear. We hypothesize that bone loss is an additional component of an AD prodrome-changes that emerge prior to dementia and are mediated by dysfunction of the central serotonergic pathways. We characterized the skeletal phenotype of htau mice that express human forms of the microtubule-associated protein tau that become pathologically hyperphosphorylated in AD. Using radiographic densitometry, we measured BMD in female and male htau mice from 2-6 months of age-time-points prior to the presence of significant tauopathy in the hippocampal/entorhinal regions characteristic of this model. We found a significantly reduced BMD phenotype in htau mice that was most pronounced in males. Using western blotting and immunofluorescence, we showed overall reduced tryptophan hydroxylase (TPH) protein in htau brainstem and a 70% reduction in
Dengler-Crish Christine M; Smith Matthew A; Wilson Gina N
Journal of Alzheimer's disease : JAD
2017
1905-07
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.3233/JAD-160658" target="_blank" rel="noreferrer noopener">10.3233/JAD-160658</a>
Shared mechanisms: osteoporosis and Alzheimer's disease?
Alzheimer's disease; dementia; osteoporosis; serotonin; Wnt
Dengler-Crish Christine M; Elefteriou Florent
Aging
2019
2019-02
<a href="http://doi.org/10.18632/aging.101828" target="_blank" rel="noreferrer noopener">10.18632/aging.101828</a>
Astrocytic changes with aging and Alzheimer's disease-type pathology in chimpanzees
Aging; Alzheimer's disease; astrocytes; cerebral cortex; chimpanzees; hippocampus; prefrontal cortex; RRID: AB2109645; RRID: AB223647; RRID: AB2313952; RRID: AB2314223; stereology
Astrocytes are the main homeostatic cell of the central nervous system. In addition, astrocytes mediate an inflammatory response when reactive to injury or disease known as astrogliosis. Astrogliosis is marked by an increased expression of glial fibrillary acidic protein (GFAP) and cellular hypertrophy. Some degree of astrogliosis is associated with normal aging and degenerative conditions such as Alzheimer's disease (AD) and other dementing illnesses in humans. The recent observation of pathological markers of AD (amyloid plaques and neurofibrillary tangles) in aged chimpanzee brains provided an opportunity to examine the relationships among aging, AD-type pathology, and astrocyte activation in our closest living relatives. Stereologic methods were used to quantify GFAP-immunoreactive astrocyte density and soma volume in layers I, III, and V of the prefrontal and middle temporal cortex, as well as in hippocampal fields CA1 and CA3. We found that the patterns of astrocyte activation in the aged chimpanzee brain are distinct from humans. GFAP expression does not increase with age in chimpanzees, possibly indicative of lower oxidative stress loads. Similar to humans, chimpanzee layer I astrocytes in the prefrontal cortex are susceptible to AD-like changes. Both prefrontal cortex layer I and hippocampal astrocytes exhibit a high degree of astrogliosis that is positively correlated with accumulation of amyloid beta and tau proteins. However, unlike humans, chimpanzees do not display astrogliosis in other cortical layers. These results demonstrate a unique pattern of cortical aging in chimpanzees and suggest that inflammatory processes may differ between humans and chimpanzees in response to pathology.
Munger Emily L; Edler Melissa K; Hopkins William D; Ely John J; Erwin Joseph M; Perl Daniel P; Mufson Elliott J; Hof Patrick R; Sherwood Chet C; Raghanti Mary Ann
The Journal of Comparative Neurology
2019
2019-05
<a href="http://doi.org/10.1002/cne.24610" target="_blank" rel="noreferrer noopener">10.1002/cne.24610</a>
Inhibition Of Phosphorylation Of Trkb And Trkc And Their Signal Transduction By Alpha(2)-macroglobulin
alpha(2)-macroglobulin; alpha(2)-macroglobulin; alpha(2)-macroglobulin; Alzheimer's disease; Biochemistry & Molecular Biology; cerebrospinal-fluid; dopaminergic-neurons; mitogen-activated protein kinases; nerve growth-factor; neurite outgrowth; Neurodegenerative diseases; Neurosciences & Neurology; neurotrophic factor; neurotrophins; phospholipase C-gamma 1; rat caudate-putamen; signal-transduction; tyrosine protein-kinase
Monoamine-activated alpha(2)-macroglobulin (alpha(2)M) was shown to reduce the dopamine concentration in corpus striatum of adult rat brains and inhibit other neuronal functions in vivo and in vitro. As brain-derived neurotrophic factor, neurotrophin-4, and neurotrophin-3 are important neurotrophic factors for dopaminergic neurons, the effect of monoamine-activated alpha(2)M on signal transduction by trkB and trkC was investigated. The results show that monoamine-activated alpha(2)M binds to trkB and inhibits brain-derived neurotrophic factor/neurotrophin-4-promoted autophosphorylation of trkB in a dose-dependent manner in both trkB-expressing NIH3T3 (NIH3T3-trkB) and human neuroblastoma SH-SY5Y cells. Monoamine-activated alpha(2)M also blocks tyrosine phosphorylation of phospholipase C-gamma 1 and extracellular signal-regulated protein kinase(ERK)-1,which are key intracellular proteins involved in trkB signal transduction. Similarly, monoamine-activated alpha(2)M inhibits tyrosine phosphorylation of neurotrophin-3-induced trkC and its signal transduction in a dose-dependent manner in NIH3T3 cells expressing trkC (NIH3T3-trkC). In contrast to monoamine-activated alpha(2)M, normal alpha(2)M has little or no significant inhibitory effect on the phosphorylation of trkB and trkC. In addition, the retinoic acid-promoted tyrosine phosphorylation of phospholipase C-gamma 1, ERK-1, and/or ERK-2 in SH-SY5Y cells was unaffected by monoamine-activated alpha(2)M; this suggests that the inhibitory effect of activated alpha(2)M on the neurotrophin-stimulated phosphorylation of intracellular signalling proteins may be specific. Taken together, the data indicate that activated alpha(2)M is a pan-trk inhibitor, which by virtue of its binding to trk receptors may block trk-mediated signal transduction in dopaminergic neurons and lead to reduction of dopamine concentration in corpus striatum.
Hu Y Q; Koo P H
Journal of Neurochemistry
1998
1998-07
Journal Article or Conference Abstract Publication
n/a
Polycyclic Cage Structures As Lipophilic Scaffolds For Neuroactive Drugs
Alzheimer's disease; apoptosis; benzodiazepine-receptors; biological activity; cage compounds; calcium-antagonists; carbonic-anhydrase inhibitors; d-aspartate receptor; drug design; fluorescent ligands; monoamine-oxidase-b; neuroprotection; nitric-oxide; parkinsons-disease; Pharmacology & Pharmacy; sigma-receptors
Polycyclic cage scaffolds have been successfully used in the development of numerous lead compounds demonstrating activity in the central nervous system (CNS). Several neurodegenerative diseases, such as Alzheimers disease, Parkinsons disease, Huntingtons disease, schizophrenia, and stroke, as well as drug abuse, can be modulated with polycyclic cage derivatives. These cage moieties, including adamantane and pentacycloundecane derivatives, improve the pharmacokinetic and pharmacodynamic properties of conjugated parent drugs and serve as an important scaffold in the design of therapeutically active agents for the treatment of neurological disorders. In this Minireview, we focus on the recent developments in the field of polycyclic cage compounds, as well as the relationship between the lipophilic character of these cage-derived drugs and the ability of such compounds to target and reach the CNS and improve the pharmacodynamic properties of compounds conjugated to it.
Joubert J; Geldenhuys W J; Van der Schyf C J; Oliver D W; Kruger H G; Govender T; Malan S F
Chemmedchem
2012
2012-03
Journal Article or Conference Abstract Publication
<a href="http://doi.org/10.1002/cmdc.201100559" target="_blank" rel="noreferrer noopener">10.1002/cmdc.201100559</a>
Accumulating Beta-amyloid Alters The Post-injury Inflammatory Response
Alzheimer's disease; beta-amyloid; General & Internal Medicine; macrophage; neuroinflammation; Neurosciences & Neurology
Kokiko-Cochran O; Ransohoff L; Veenstra M; Lee S; Sikora M; Teknipp R; Xu G X; Bemiller S; Wilson G; Crish S; Bhaskar K; Lee Y S; Ransohoff R; Lamb B
Journal of Neurotrauma
2015
2015-06
Journal Article or Conference Abstract Publication
n/a
Protective Effects Of Ginsenoside Rg(2) Against Glutamate-induced Neurotoxicity In Pc12 Cells
Alzheimer's disease; apoptosis; beta peptide; calpain; damage; excitotoxicity; expression; Integrative & Complementary; ischemic neuronal death; Medicine; neuroprotection; nitric-oxide; Panax ginseng; Panax ginseng; Pharmacology & Pharmacy; Plant Sciences; receptors; system
We investigated the effect of ginsenoside Rg(2) on neurotoxic activities induced by glutamate in PC12 cells. The cells were incubated with glutamate (1 mmol/L), glutamate and ginsenoside Rg(2) (0.05, 0.1, 0.2 mmol/L) or nimodipine (5 mu mol/L for 24 h. The cellular viability was assessed by MTT assay. The lipid peroxidation products malondialdehyde (MDA) and nitrogen oxide (NO) were measured by a spectrophotometric method. Fura2/AM, as a cell permeable fluorescent probe for Ca2+, was used to detect intracellular Ca2+ concentration ([Ca2+](i)) using a monespectrofluorometer. Immunocytochemical techniques were employed to check the protein expression levels of calpain II, caspase-3 and beta-amyloid (A beta)1-40 in PC12 cells. The results showed that glutamate decreased the cell viability, increased [Ca2+](i), lipid peroxidation (the excessive production of MDA, NO) and the protein expression levels of calpain II, caspase-3 and A beta 1-40 in PC12 cells. Ginsenoside Rg(2) significantly attenuated glutamate-induced neurotoxic effects upon these parameters at all doses tested. Our study suggests that ginsenoside Rg(2) has a neuroprotective effect against glutamate-induced neurotoxicity through mechanisms related to anti-oxidation and anti-apoptosis. In addition, the inhibitory effect of ginsenoside Rg(2) against the formation of A beta 1-40 suggests that ginsenoside Rg(2) may also represent a potential treatment strategy for Alzheimer's disease. (c) 2007 Elsevier Ireland Ltd. All rights reserved.
Li N; Liu B; Dluzen D E; Jin Y
Journal of Ethnopharmacology
2007
2007-05
Journal Article or Conference Abstract Publication
<a href="http://doi.org/10.1016/j.jep.2006.12.015" target="_blank" rel="noreferrer noopener">10.1016/j.jep.2006.12.015</a>
Retinal ganglion cell loss and gliosis in the retinofugal projection following intravitreal exposure to amyloid-beta.
Inflammation; Glaucoma; Alzheimer's disease; Retina; Superior colliculus; Amyloid-beta; CD36; Cluster of differentiation 36
Pathological accumulations of amyloid-beta (Aβ) peptide are found in retina early in Alzheimer's disease, yet its effects on retinal neuronal structure remain unknown. To investigate this, we injected fibrillized Aβ(1-42) protein into the eye of adult C57BL/6 J mice and analyzed the retina, optic nerve (ON), and the superior colliculus (SC), the primary retinal target in mice. We found that retinal Aβ exposure stimulated microglial activation and retinal ganglion cell (RGC) loss as early as 1-week post-injection. Pathology was not limited to the retina, but propagated into other areas of the central nervous system. Microgliosis spread throughout the retinal projection (retina, ON, and SC), with multiplex protein quantitation demonstrating an increase in endogenously produced Aβ in the ON and SC corresponding to the injected retinas. Surprisingly, this pathology spread to the opposite side, with unilateral Aβ eye injections driving increased Aβ levels, neuroinflammation, and RGC death in the opposite, un-injected retinal projection. As Aβ-mediated microglial activation has been shown to propagate Aβ pathology, we also investigated the role of the Aβ-binding microglial scavenger receptor CD36 in this pathology. Transgenic mice lacking the CD36 receptor were resistant to Aβ-induced inflammation and RGC death up to 2 weeks following exposure. These results indicate that Aβ pathology drives regional neuropathology in the retina and does not remain isolated to the affected eye, but spreads throughout the nervous system. Further, CD36 may serve as a promising target to prevent Aβ-mediated inflammatory damage.
Simons ES;Smith M A;Dengler-Crish C M;Crish SD
Neurobiology of Disease
2020
2020-10-26
journalArticle
<a href="http://doi.org/10.1016/j.nbd.2020.105146" target="_blank" rel="noreferrer noopener">10.1016/j.nbd.2020.105146</a>
Age, sex, and regional differences in scavenger receptor CD36 in the mouse brain: Potential relevance to cerebral amyloid angiopathy and Alzheimer's disease.
brain; aging; mouse; Alzheimer's disease; cerebral amyloid angiopathy; vasculature; CD36; Alzheimer' s disease
Scavenger receptor CD36 contributes significantly to lipid homeostasis, inflammation, and amyloid deposition, while CD36 deficiency is associated with restored cerebrovascular function in an Alzheimer's disease (AD) mouse model. Yet the distribution of CD36 has not been examined in the brain. Here, we characterized CD36 gene and protein expression in the brains of young, middle aged, aged, and elderly male and female C57BL/6J mice. Age-related increases in CD36 mRNA expression were observed in the male hippocampus and female midbrain. Additionally, male mice had greater CD36 mRNA expression than females in the striatum, hippocampus, and midbrain. CD36 protein was primarily expressed intravascularly, and this expression differed by region, age, and sex in the mouse brain. Although male mice brains demonstrated an increase in CD36 protein with age in several cortices, basal ganglia, hippocampus, and midbrain, a decrease with age was observed in female mice in the same regions. These data suggest that distinctive age, region, and sex expression of CD36 in the brain may contribute to Aβ deposition and neuroinflammation in AD.
Edler MK; Johnson CT; Ahmed HS; Richardson JR
The Journal of Comparative Neurology
2020
2020-12-14
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
journalArticle
<a href="http://doi.org/10.1002/cne.25089" target="_blank" rel="noreferrer noopener">10.1002/cne.25089</a>
Potential Side Effects and Adverse Events of Antipsychotic Use for Residents With Dementia in Assisted Living: Implications for Prescribers, Staff, and Families.
dementia; Alzheimer's disease; family; SYMPTOMS; medication; Alzheimer’s disease; assisted living; ALZHEIMERS-DISEASE; BENEFITS; CARE; INVOLVEMENT; MEDICATIONS; MORTALITY; NURSING-HOME RESIDENTS; PREVALENCE; RISK
Antipsychotic medications are frequently prescribed to assisted living (AL) residents who have dementia, although there is a lack of information about the potential side effects and adverse events of these medications among this population. Oversight and monitoring by family members is an important component of AL care, and it is important to understand family awareness of antipsychotic use and reports of potential side effects and adverse events. This cross-sectional, descriptive study of family members of 283 residents with dementia receiving antipsychotic medications in 91 AL communities found high rates (93%) of symptoms that could be potential side effects and a 6% rate of potential adverse events. The majority of families were aware their relative was taking an antipsychotic. Findings suggest that obtaining family perspectives of potential side effects and adverse events related to medication use may contribute to overall improvement in the safety of AL residents living with dementia.
Beeber AS; Zimmerman S; Wretman CJ; Palmertree S; Patel K; Sloane PD
Journal Of Applied Gerontology : The Official Journal Of The Southern Gerontological Society
2021
2021-06-23
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
journalArticle
<a href="http://doi.org/10.1177/07334648211023678" target="_blank" rel="noreferrer noopener">10.1177/07334648211023678</a>