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AIMS: We sought to identify and optimise a universally available histological marker for pericytes in the human brain. Such a marker could be a useful tool for researchers. Further, identifying a gene expressed relatively specifically in human pericytes could provide new insights into the biological functions of this fascinating cell type. METHODS: We analysed single-cell RNA expression profiles derived from different human and mouse brain regions using a high-throughput and low-cost single-cell transcriptome sequencing method called EasySci. Through this analysis, we were able to identify specific gene markers for pericytes, some of which had not been previously characterised. We then used commercially (and therefore universally) available antibodies to immunolabel the pericyte-specific gene products in formalin-fixed paraffin-embedded (FFPE) human brains and also performed immunoblots to determine whether appropriately sized proteins were recognised. RESULTS: In the EasySci data sets, highly pericyte-enriched expression was notable for SLC6A12 and SLC19A1. Antibodies against these proteins recognised bands of approximately the correct size in immunoblots of human brain extracts. Following optimisation of the immunohistochemical technique, staining for both antibodies was strongly positive in small blood vessels and was far more effective than a PDGFRB antibody at staining pericyte-like cells in FFPE human brain sections. In an exploratory sample of other human organs (kidney, lung, liver, muscle), immunohistochemistry did not show the same pericyte-like pattern of staining. CONCLUSIONS: The SLC6A12 antibody was well suited for labelling pericytes in human FFPE brain sections, based on the combined results of single-cell RNA-seq analyses, immunoblots and immunohistochemical studies.
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Pericitos , ARN , Humanos , Ratones , Animales , Pericitos/metabolismo , ARN/metabolismo , Encéfalo/metabolismo , Receptor beta de Factor de Crecimiento Derivado de Plaquetas/metabolismo , InmunohistoquímicaRESUMEN
Cerebrovascular pathologies other than frank infarctions are commonly seen in aged brains. Here, we focus on multi-lumen vascular profiles (MVPs), which are characterized by multiple vessel lumens enclosed in a single vascular channel. Little information exists on the prevalence, risk factors, and co-pathologies of MVPs. Therefore, we used samples and data from the University of Kentucky Alzheimer's Disease Research Center (n = 91), the University of Kentucky Pathology Department (n = 31), and the University of Pittsburgh Pathology Department (n = 4) to study MVPs. Age at death was correlated with MVP density in the frontal neocortex, Brodmann Area 9 (r = 0.51; p < 0.0001). Exploratory analyses were performed to evaluate the association between conventional vascular risk factors (e.g., hypertension, diabetes), cardiovascular diseases (e.g., heart attack, arrhythmia), and cerebrovascular disease (e.g., stroke); the only nominal association with MVP density was a self-reported history of brain trauma (Prevalence Ratio = 2.1; 95 CI 1.1-3.9, before correcting for multiple comparisons). No specific associations were detected between neuropathological (e.g., brain arteriolosclerosis) or genetic (e.g., APOE) variables and MVP density. Using a tissue clearing method called SeeDB, we provide 3-dimensional images of MVPs in brain tissue. We conclude that MVPs are an age-related brain pathology and more work is required to identify their clinical-pathological correlation and associated risk factors.
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Lesiones Traumáticas del Encéfalo , Accidente Cerebrovascular , Humanos , Anciano , Encéfalo , Neuropatología , EnvejecimientoRESUMEN
Background: EWSR1::PATZ1 fusion tumors are exceedingly rare in the central nervous system with only 14 prior cases documented. PATZ1 fusion neuroepithelial tumors are beginning to be recognized as a distinct molecular class of neoplasms that most often occur in children and young adults. These tumors are polyphenotypic, show diverse morphologic features, may be low- or high-grade, and tend to have an intermediate prognosis. Case presentation: Herein, we present an unusual case of a high-grade neuroepithelial tumor in a young man with an EWSR1::PATZ1 fusion. This case is unique because the tumor appears to have undergone high-grade transformation from a persistent low-grade glioma, which has yet to be reported. Furthermore, this case is the first to document concurrent RB1 loss, SMAD4 loss, and TP53 inactivation in this tumor type, which correlates with high-grade transformation. Fortunately, this patient is alive 2.5 years after treatment and 18.5 years after initial presentation, which provides a unique window into how these tumors clinically behave over a long follow-up period. Finally, we discuss the altered molecular pathways that are a result of the EWSR1::PATZ1 fusion and discuss potential therapeutic targets. Conclusion: Awareness of the emerging entity of PATZ1 fusion neuroepithelial tumors is important not only for accurate diagnostic and prognostic purposes but also for predicting response to therapy.
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An international consensus report in 2019 recommended a classification system for limbic-predominant age-related TDP-43 encephalopathy neuropathologic changes (LATE-NC). The suggested neuropathologic staging system and nomenclature have proven useful for autopsy practice and dementia research. However, some issues remain unresolved, such as cases with unusual features that do not fit with current diagnostic categories. The goal of this report is to update the neuropathologic criteria for the diagnosis and staging of LATE-NC, based primarily on published data. We provide practical suggestions about how to integrate available genetic information and comorbid pathologies [e.g., Alzheimer's disease neuropathologic changes (ADNC) and Lewy body disease]. We also describe recent research findings that have enabled more precise guidance on how to differentiate LATE-NC from other subtypes of TDP-43 pathology [e.g., frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS)], and how to render diagnoses in unusual situations in which TDP-43 pathology does not follow the staging scheme proposed in 2019. Specific recommendations are also made on when not to apply this diagnostic term based on current knowledge. Neuroanatomical regions of interest in LATE-NC are described in detail and the implications for TDP-43 immunohistochemical results are specified more precisely. We also highlight questions that remain unresolved and areas needing additional study. In summary, the current work lays out a number of recommendations to improve the precision of LATE-NC staging based on published reports and diagnostic experience.
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Enfermedad de Alzheimer , Esclerosis Amiotrófica Lateral , Demencia Frontotemporal , Humanos , Enfermedad de Alzheimer/patología , Demencia Frontotemporal/patología , Esclerosis Amiotrófica Lateral/patología , Proteínas de Unión al ADN/genéticaRESUMEN
Limbic-predominant age-related TDP-43 encephalopathy neuropathologic change (LATE-NC) and Alzheimer's disease neuropathologic change (ADNC) are each associated with substantial cognitive impairment in aging populations. However, the prevalence of LATE-NC across the full range of ADNC remains uncertain. To address this knowledge gap, neuropathologic, genetic, and clinical data were compiled from 13 high-quality community- and population-based longitudinal studies. Participants were recruited from United States (8 cohorts, including one focusing on Japanese-American men), United Kingdom (2 cohorts), Brazil, Austria, and Finland. The total number of participants included was 6196, and the average age of death was 88.1 years. Not all data were available on each individual and there were differences between the cohorts in study designs and the amount of missing data. Among those with known cognitive status before death (n = 5665), 43.0% were cognitively normal, 14.9% had MCI, and 42.4% had dementia-broadly consistent with epidemiologic data in this age group. Approximately 99% of participants (n = 6125) had available CERAD neuritic amyloid plaque score data. In this subsample, 39.4% had autopsy-confirmed LATE-NC of any stage. Among brains with "frequent" neuritic amyloid plaques, 54.9% had comorbid LATE-NC, whereas in brains with no detected neuritic amyloid plaques, 27.0% had LATE-NC. Data on LATE-NC stages were available for 3803 participants, of which 25% had LATE-NC stage > 1 (associated with cognitive impairment). In the subset of individuals with Thal Aß phase = 0 (lacking detectable Aß plaques), the brains with LATE-NC had relatively more severe primary age-related tauopathy (PART). A total of 3267 participants had available clinical data relevant to frontotemporal dementia (FTD), and none were given the clinical diagnosis of definite FTD nor the pathological diagnosis of frontotemporal lobar degeneration with TDP-43 inclusions (FTLD-TDP). In the 10 cohorts with detailed neurocognitive assessments proximal to death, cognition tended to be worse with LATE-NC across the full spectrum of ADNC severity. This study provided a credible estimate of the current prevalence of LATE-NC in advanced age. LATE-NC was seen in almost 40% of participants and often, but not always, coexisted with Alzheimer's disease neuropathology.
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Enfermedad de Alzheimer , Demencia Frontotemporal , Enfermedades del Sistema Nervioso , Anciano de 80 o más Años , Enfermedad de Alzheimer/genética , Amiloide , Autopsia , Proteínas de Unión al ADN , Humanos , Masculino , Placa Amiloide/patologíaRESUMEN
Loss of physiological microglial function may increase the propagation of neurodegenerative diseases. Cellular senescence is a hallmark of aging; thus, we hypothesized age could be a cause of dystrophic microglia. Stereological counts were performed for total microglia, 2 microglia morphologies (hypertrophic and dystrophic) across the human lifespan. An age-associated increase in the number of dystrophic microglia was found in the hippocampus and frontal cortex. However, the increase in dystrophic microglia was proportional to the age-related increase in the total number of microglia. Thus, aging alone does not explain the presence of dystrophic microglia. We next tested if dystrophic microglia could be a disease-associated microglia morphology. Compared with controls, the number of dystrophic microglia was greater in cases with either Alzheimer's disease, dementia with Lewy bodies, or limbic-predominant age-related TDP-43 encephalopathy. These results demonstrate that microglia dystrophy, and not hypertrophic microglia, are the disease-associated microglia morphology. Finally, we found strong evidence for iron homeostasis changes in dystrophic microglia, providing a possible molecular mechanism driving the degeneration of microglia in neurodegenerative disease.
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Envejecimiento Saludable/patología , Microglía/patología , Microglía/fisiología , Enfermedades Neurodegenerativas/patología , Senescencia Celular , Femenino , Lóbulo Frontal/citología , Lóbulo Frontal/patología , Hipocampo/citología , Hipocampo/patología , Homeostasis , Humanos , Hipertrofia , Hierro/metabolismo , Masculino , Microglía/metabolismo , Enfermedades Neurodegenerativas/etiologíaRESUMEN
We found evidence of late-onset Alzheimer disease (LOAD)-associated genetic polymorphism within an exon of Mucin 6 (MUC6) and immediately downstream from another gene: Adaptor Related Protein Complex 2 Subunit Alpha 2 (AP2A2). PCR analyses on genomic DNA samples confirmed that the size of the MUC6 variable number tandem repeat (VNTR) region was highly polymorphic. In a cohort of autopsied subjects with quantitative digital pathology data (n = 119), the size of the polymorphic region was associated with the severity of pTau pathology in neocortex. In a separate replication cohort of autopsied subjects (n = 173), more pTau pathology was again observed in subjects with longer VNTR regions (p = 0.031). Unlike MUC6, AP2A2 is highly expressed in human brain. AP2A2 expression was lower in a subset analysis of brain samples from persons with longer versus shorter VNTR regions (p = 0.014 normalizing with AP2B1 expression). Double-label immunofluorescence studies showed that AP2A2 protein often colocalized with neurofibrillary tangles in LOAD but was not colocalized with pTau proteinopathy in progressive supranuclear palsy, or with TDP-43 proteinopathy. In summary, polymorphism in a repeat-rich region near AP2A2 was associated with neocortical pTau proteinopathy (because of the unique repeats, prior genome-wide association studies were probably unable to detect this association), and AP2A2 was often colocalized with neurofibrillary tangles in LOAD.
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Complejo 2 de Proteína Adaptadora/genética , Subunidades alfa de Complejo de Proteína Adaptadora/genética , Enfermedad de Alzheimer/genética , Mucina 6/genética , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/patología , Autopsia , Estudios de Cohortes , Femenino , Estudio de Asociación del Genoma Completo , Genotipo , Humanos , Masculino , Repeticiones de Minisatélite , Ovillos Neurofibrilares/genética , Ovillos Neurofibrilares/patología , Polimorfismo Genético/genética , Polimorfismo de Nucleótido Simple , Proteinopatías TDP-43/genética , Proteinopatías TDP-43/patologíaRESUMEN
INTRODUCTION: Brain tumor treatment and survival information is generally limited in large-scale cancer datasets. We provide a clinical investigation of current patterns of care and survival estimates for central nervous system (CNS) tumors treated in the United States. METHODS: We analyzed the National Cancer Database from 2004-2015 for all patients with diagnosis of primary CNS tumors. We describe patient demographics, treatment modality, and analyzed survival estimates. RESULTS: 512,168 patient tumor records were examined. The most common histology was meningioma (43.6%), followed by glioblastoma (22.0%), and nerve sheath tumors (10.6%). Patients had a median age of 60 years, with a female (57.9%), white (85.0%), and non-Hispanic (87.8%) predominance. Tumors were reported as World Health Organization (WHO) grade I for 55.9% of the patients, grade II for 5.9%, grade III for 4.4%, grade IV for 24.3%, and grade unknown or not applicable for 9.4%. Overall, 56% underwent surgical procedures, 30.4% received radiation, and 20.6% received chemotherapy. Radiation plus chemotherapy and surgery was the most common treatment modality in high-grade tumors (40.5% in WHO grade III and 49.3% in WHO grade IV), while surgery only or watchful waiting was preferred in low-grade tumors. Older age, male gender, non-Hispanic origin, higher number of comorbidities, and lower socioeconomic status were identified as risk factors for mortality. CONCLUSIONS: Our analysis provides long-term survival estimates and initial treatment decisions for patients with CNS tumors in hospitals throughout the United States. Age, comorbidities, gender, ethnicity, and socioeconomic characteristics were determinants of survival.
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Neoplasias del Sistema Nervioso Central/mortalidad , Neoplasias del Sistema Nervioso Central/terapia , Adolescente , Adulto , Factores de Edad , Anciano , Estudios de Casos y Controles , Neoplasias del Sistema Nervioso Central/clasificación , Neoplasias del Sistema Nervioso Central/patología , Niño , Preescolar , Terapia Combinada , Femenino , Estudios de Seguimiento , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Pronóstico , Tasa de Supervivencia , Factores de Tiempo , Adulto JovenRESUMEN
BACKGROUND: Meningiomas are the most common central nervous system tumor. We describe current trends in treatment and survival using the largest cancer dataset in the United States. METHODS: We analyzed the National Cancer Database from 2004 to 2014, for all patients with diagnosis of meningioma. RESULTS: 201,765 cases were analyzed. Patients were most commonly White (81.9%) females (73.2%) with a median age of 64 years. Fifty percent of patients were diagnosed by imaging. Patients were reported as grade I (24.9%), grade II (5.0%), grade III (0.7%), or unknown WHO grade (69.4%). Patients diagnosed by imaging were older, received treatment in community facilities, had higher Charlson-Deyo score, and a lower rate of private insurance. Watchful waiting was the most common treatment modality (46.7%), followed by surgery only (40%). Grade II and III patients were more likely to receive therapy. Watchful waiting increased from 35.2% in 2004 to 51.4% in 2014. Younger age, male gender, private insurance, and treatment in academic facilities were determinants for receipt of surgery and/or radiation. Median survival was 12.6 years, higher in histologically confirmed cases (13.1 years). Older patients, Blacks, males, those that received radiation plus surgery, and were treated in community facilities had an increased risk of mortality. CONCLUSIONS: Over half of patients were diagnosed by imaging, suggesting a higher role of clinical determinants over histological confirmation in treatment decisions. Watchful waiting as initial management is increasing. Our survival analysis favored histological confirmation. Patients receiving radiation and surgery had an increased risk of mortality.
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Bases de Datos Factuales , Neoplasias Meníngeas/terapia , Meningioma/terapia , Espera Vigilante , Adolescente , Adulto , Anciano , Niño , Preescolar , Terapia Combinada , Manejo de la Enfermedad , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Neoplasias Meníngeas/mortalidad , Neoplasias Meníngeas/patología , Meningioma/mortalidad , Meningioma/patología , Persona de Mediana Edad , Pronóstico , Factores de Riesgo , Factores Socioeconómicos , Tasa de Supervivencia , Estados Unidos , Adulto JovenRESUMEN
Data from a large autopsy series were analyzed to address questions pertinent to primary age-related tauopathy (PART) and Alzheimer's disease (AD): what factors are associated with increased severity of neurofibrillary degeneration in brains that lack neuritic amyloid plaques?; is there an association between Apolipoprotein E (APOE) alleles and PART pathologic severity independent of amyloid-ß (Aß) deposits?; and, how do the stains used to detect plaques and tangles impact the experimental results? Neuropathologic data were evaluated from elderly research volunteers whose brain autopsies were performed at University of Kentucky Alzheimer's Disease Center (UK-ADC; N = 145 subjects). All of the included subjects' brains lacked neuritic amyloid plaques according to the CERAD diagnostic criteria and the average final MMSE score before death was 26.8±4.6 stdev. The study incorporated evaluation of tissue with both silver histochemical stains and immunohistochemical stains to compare results; the immunohistochemical stains (Aß and phospho-tau) were scanned and quantified using digital pathologic methods. Immunohistochemical stains provided important advantages over histochemical stains due to sensitivity and detectability via digital methods. When AD-type pathology was in its presumed earliest phases, neocortical parenchymal Aß deposits were associated with increased medial temporal lobe neurofibrillary tangles. The observation supports the NIA-AA consensus recommendation for neuropathologic diagnoses, because even these "diffuse" Aß deposits signal that AD pathobiologic mechanisms are occurring. Further, the data were most compatible with the hypothesis that the APOEÉ4 allele exerts its effect(s) via driving Aß deposition, i.e., an "upstream" influence, rather than being associated directly with Aß- independent PART pathology.
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Envejecimiento/genética , Péptidos beta-Amiloides/metabolismo , Encéfalo/metabolismo , Ovillos Neurofibrilares/metabolismo , Placa Amiloide/metabolismo , Anciano , Anciano de 80 o más Años , Envejecimiento/patología , Péptidos beta-Amiloides/ultraestructura , Apolipoproteínas E/genética , Encéfalo/ultraestructura , Femenino , Humanos , Masculino , Ovillos Neurofibrilares/genética , Ovillos Neurofibrilares/ultraestructura , Placa Amiloide/patología , Placa Amiloide/ultraestructura , Tinción con Nitrato de Plata , Proteínas tau/metabolismoRESUMEN
INTRODUCTION: Inheritance of the ε4 allele of apolipoprotein E (APOE) increases a person's risk of developing both Alzheimer's disease (AD) and Lewy body dementia (LBD), yet the underlying mechanisms behind this risk are incompletely understood. The recent identification of reduced APOE DNA methylation in AD postmortem brains prompted this study to investigate APOE methylation in LBD. METHODS: Genomic DNA from postmortem brain tissues (frontal lobe and cerebellum) of neuropathological pure (np) controls and npAD, LBD + AD, and npLBD subjects were bisulfite pyrosequenced. DNA methylation levels of two APOE subregions were then compared for these groups. RESULTS: APOE DNA methylation was significantly reduced in npLBD compared with np controls, and methylation levels were lowest in the LBD + AD group. DISCUSSION: Given that npLBD and npAD postmortem brains shared a similar reduction in APOE methylation, it is possible that an aberrant epigenetic change in APOE is linked to risk for both diseases.
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Apolipoproteínas E/genética , Encéfalo , Metilación de ADN/genética , Lóbulo Frontal/patología , Enfermedad por Cuerpos de Lewy/genética , Anciano , Anciano de 80 o más Años , Alelos , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/patología , Autopsia , Encéfalo/metabolismo , Encéfalo/patología , Femenino , Genotipo , Humanos , Enfermedad por Cuerpos de Lewy/patología , MasculinoRESUMEN
Importance: Although seroepidemiological studies indicate that greater than 50% of the population has been infected with John Cunningham virus (JCV), the sites of JCV persistence remain incompletely characterized. Objective: To determine sites of JCV persistence in immunologically healthy individuals. Design, Setting, and Participants: Tissue specimens from multiple sites including brain, renal, and nonrenal tissues were obtained at autopsy performed in the Department of Pathology at the University of Kentucky from 12 immunologically healthy patients between February 9, 2011, and November 27, 2012. Quantitative polymerase chain reaction was performed on the tissue specimens and urine. Serum JCV antibody status was determined by enzyme-linked immunosorbent assay. Main Outcomes and Measures: The detection and quantification of JCV from the tissues by quantitative polymerase chain reaction illuminated sites of viral persistence. These results were correlated with JCV antibody levels. Results: Autopsies were performed on 12 individuals, 10 men and 2 women, ranging in age from 25 to 75 years (mean, 55.3 years). Seven of 12 individuals were JCV antibody seropositive based on absorbance units. Serostatus was associated with amounts of JCV DNA in urine and its tissue distribution. John Cunningham virus DNA was found in 75% of genitourinary tissue samples from donors (18 of 24) with high JCV antibody levels, 13.3% of donors with low levels i(4 of 30), and 0% of seronegative persons (0 of 32). In nongenitourinary tissues, JCV DNA was detected in 45.1% of tissue samples of donors (32 of 71) with high JCV, 2.2% of donors with low JCV serostatus (2 of 93), and 0% of seronegative persons (0 of 43). Genitourinary tissues had higher copy numbers than other sites. John Cunningham virus DNA was detected in urine of seronegative individuals in a research-grade assay. Conclusions and Relevance: Persistent (latent or actively replicating) JCV infection mostly predominates in genitourinary tissues but distributes in other tissues at low copy number. The distribution and copy numbers of the virus appear to correlate with urinary JCV shedding and serostatus.
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Anticuerpos Antivirales/sangre , ADN Viral/orina , Virus JC/genética , Virus JC/inmunología , Infecciones Tumorales por Virus , Adulto , Anciano , Autopsia , Femenino , Humanos , Huésped Inmunocomprometido , Masculino , Persona de Mediana Edad , Infecciones por Polyomavirus/inmunología , Estudios Seroepidemiológicos , Distribución Tisular , Infecciones Tumorales por Virus/genética , Infecciones Tumorales por Virus/inmunología , Infecciones Tumorales por Virus/virologíaRESUMEN
A subtype of microglia is defined by the morphological appearance of the cells as rod shaped. Little is known about this intriguing cell type, as there are only a few case reports describing rod-shaped microglia in the neuropathological literature. Rod-shaped microglia were shown recently to account for a substantial proportion of the microglia cells in the hippocampus of both demented and cognitively intact aged individuals. We hypothesized that aging could be a defining feature in the occurrence of rod-shaped microglia. To test this hypothesis, 2 independent series of autopsy cases (total n = 168 cases), which covered the adult lifespan from 20 to 100+ years old, were included in the study. The presence or absence of rod-shaped microglia was scored on IBA1 immunohistochemically stained slides for the hippocampus and cortex. We found that age was one of the strongest determinants for the presence of rod-shaped microglia in the hippocampus and the cortex. We found no association with the presence of rod-shaped microglia and a self-reported history of a TBI. Alzheimer's disease-related pathology was found to influence the presence of rod-shaped microglia, but only in the parietal cortex and not in the hippocampus or temporal cortex. Future studies are warranted to determine the functional relevance of rod-shaped microglia in supporting the health of neurons in the aged brain, and the signaling processes that regulate the formation of rod-shaped microglia.
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Envejecimiento/patología , Microglía/patología , Adulto , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/patología , Autopsia , Corteza Cerebral/citología , Femenino , Hipocampo/citología , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
Risk factors and cognitive sequelae of brain arteriolosclerosis pathology are not fully understood. To address this, we used multimodal data from the National Alzheimer's Coordinating Center and Alzheimer's Disease Neuroimaging Initiative data sets. Previous studies showed evidence of distinct neurodegenerative disease outcomes and clinical-pathological correlations in the "oldest-old" compared to younger cohorts. Therefore, using the National Alzheimer's Coordinating Center data set, we analyzed clinical and neuropathological data from two groups according to ages at death: < 80 years (n = 1008) and ≥80 years (n = 1382). In both age groups, severe brain arteriolosclerosis was associated with worse performances on global cognition tests. Hypertension (but not diabetes) was a brain arteriolosclerosis risk factor in the younger group. In the ≥ 80 years age at death group, an ABCC9 gene variant (rs704180), previously associated with aging-related hippocampal sclerosis, was also associated with brain arteriolosclerosis. A post-hoc arterial spin labeling neuroimaging experiment indicated that ABCC9 genotype is associated with cerebral blood flow impairment; in a convenience sample from Alzheimer's Disease Neuroimaging Initiative (n = 15, homozygous individuals), non-risk genotype carriers showed higher global cerebral blood flow compared to risk genotype carriers. We conclude that brain arteriolosclerosis is associated with altered cognitive status and a novel vascular genetic risk factor.
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Envejecimiento/psicología , Arterioloesclerosis/etiología , Arterioloesclerosis/psicología , Cognición , Anciano , Anciano de 80 o más Años , Arterioloesclerosis/genética , Encéfalo/patología , Encéfalo/fisiopatología , Circulación Cerebrovascular/genética , Bases de Datos Factuales , Variación Genética , Humanos , Hipertensión/complicaciones , Factores de Riesgo , Receptores de Sulfonilureas/genéticaRESUMEN
The pathology-based classification of Alzheimer's disease (AD) and other neurodegenerative diseases is a work in progress that is important for both clinicians and basic scientists. Analyses of large autopsy series, biomarker studies, and genomics analyses have provided important insights about AD and shed light on previously unrecognized conditions, enabling a deeper understanding of neurodegenerative diseases in general. After demonstrating the importance of correct disease classification for AD and primary age-related tauopathy, we emphasize the public health impact of an underappreciated AD "mimic," which has been termed "hippocampal sclerosis of aging" or "hippocampal sclerosis dementia." This pathology affects >20% of individuals older than 85 years and is strongly associated with cognitive impairment. In this review, we provide an overview of current hypotheses about how genetic risk factors (GRN, TMEM106B, ABCC9, and KCNMB2), and other pathogenetic influences contribute to TDP-43 pathology and hippocampal sclerosis. Because hippocampal sclerosis of aging affects the "oldest-old" with arteriolosclerosis and TDP-43 pathologies that extend well beyond the hippocampus, more appropriate terminology for this disease is required. We recommend "cerebral age-related TDP-43 and sclerosis" (CARTS). A detailed case report is presented, which includes neuroimaging and longitudinal neurocognitive data. Finally, we suggest a neuropathology-based diagnostic rubric for CARTS.
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Envejecimiento/patología , Enfermedad de Alzheimer/patología , Proteínas de Unión al ADN , Hipocampo/patología , Tauopatías/patología , Anciano de 80 o más Años , Envejecimiento/genética , Enfermedad de Alzheimer/genética , Animales , Proteínas de Unión al ADN/genética , Femenino , Humanos , Esclerosis/genética , Esclerosis/patología , Tauopatías/genéticaRESUMEN
With an emphasis on evolving concepts in the field, we evaluated neuropathologic data from very old research volunteers whose brain autopsies were performed at the University of Kentucky Alzheimer's Disease Center, incorporating data from the Georgia Centenarian Study (n = 49 cases included), Nun Study (n = 17), and University of Kentucky Alzheimer's Disease Center (n = 11) cohorts. Average age of death was 102.0 (range: 98-107) years overall. Alzheimer's disease pathology was not universal (62% with "moderate" or "frequent" neuritic amyloid plaque densities), whereas frontotemporal lobar degeneration was absent. By contrast, some hippocampal neurofibrillary tangles (including primary age-related tauopathy) were observed in every case. Lewy body pathology was seen in 16.9% of subjects and hippocampal sclerosis of aging in 20.8%. We describe anatomic distributions of pigment-laden macrophages, expanded Virchow-Robin spaces, and arteriolosclerosis among Georgia Centenarians. Moderate or severe arteriolosclerosis pathology, throughout the brain, was associated with both hippocampal sclerosis of aging pathology and an ABCC9 gene variant. These results provide fresh insights into the complex cerebral multimorbidity, and a novel genetic risk factor, at the far end of the human aging spectrum.
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Envejecimiento/patología , Encéfalo/patología , Anciano de 80 o más Años , Envejecimiento/genética , Arteriosclerosis/genética , Arteriosclerosis/patología , Vasos Sanguíneos/patología , Encéfalo/irrigación sanguínea , Trastornos Cerebrovasculares/genética , Trastornos Cerebrovasculares/patología , Estudios de Cohortes , Proteínas de Unión al ADN , Femenino , Humanos , Masculino , Complejo Mediador , Enfermedades Neurodegenerativas/genética , Enfermedades Neurodegenerativas/patología , Ovillos Neurofibrilares/patologíaRESUMEN
Hippocampal sclerosis of aging (HS-Aging) is a neurodegenerative disease that mimics Alzheimer disease (AD) clinically and has a prevalence rivaling AD in advanced age. Whereas clinical biomarkers are not yet optimized, HS-Aging has distinctive pathological features that distinguish it from other diseases with "hippocampal sclerosis" pathology, such as epilepsy, cerebrovascular perturbations, and frontotemporal lobar degeneration. By definition, HS-Aging brains show neuronal cell loss and gliosis in the hippocampal formation out of proportion to AD-type pathology; it is strongly associated with aberrant TDP-43 pathology and arteriolosclerosis. Here, we describe 2 cases of "segmental" HS-Aging in which "sclerosis" in the hippocampus was evident only in a subset of brain sections by hematoxylin and eosin (H&E) stain. In these cases, TDP-43 pathology was more widespread on immunostained sections than the neuronal cell loss and gliosis seen in H&E stains. The 2 patients were cognitively intact at baseline and were tracked longitudinally over a decade using cognitive studies with at least 1 neuroimaging scan. We discuss the relevant HS-Aging literature, which indicates the need for a clearer consensus-based delineation of "hippocampal sclerosis" and TDP-43 pathologies in aged subjects.
Asunto(s)
Envejecimiento/patología , Hipocampo/patología , Enfermedades Neurodegenerativas/complicaciones , Anciano , Anciano de 80 o más Años , Proteínas de Unión al ADN/metabolismo , Femenino , Humanos , Masculino , Enfermedades Neurodegenerativas/patología , Esclerosis/etiología , Esclerosis/patologíaRESUMEN
INTRODUCTION: Neuropathological, genetic, and biochemical studies have provided support for the hypothesis that microglia participate in Alzheimer's disease (AD) pathogenesis. Despite the extensive characterization of AD microglia, there are still many unanswered questions, and little is known about microglial morphology in other common forms of age-related dementia: particularly, dementia with Lewy bodies (DLB) and hippocampal sclerosis of aging (HS-Aging). In addition, no prior studies have attempted to compare and contrast the microglia morphology in the hippocampus of various neurodegenerative conditions. RESULTS: Here we studied cases with pathologically-confirmed AD (n = 7), HS-Aging (n = 7), AD + HS-aging (n = 4), DLB (n = 12), and normal (cognitively intact) controls (NC) (n = 9) from the University of Kentucky Alzheimer's Disease Center autopsy cohort. We defined five microglia morphological phenotypes in the autopsy samples: ramified, hypertrophic, dystrophic, rod-shaped, and amoeboid. The Aperio ScanScope digital neuropathological tool was used along with two well-known microglial markers: IBA1 (a marker for both resting and activated microglia) and CD68 (a lysosomal marker in macrophages/microglia associated with phagocytic cells). Hippocampal staining analyses included studies of subregions within the hippocampal formation and nearby white matter. Using these tools and methods, we describe variation in microglial characteristics that show some degree of disease specificity, including, (1) increased microglia density and number in HS-aging and AD + HS-aging; (2) low microglia density in DLB; (3) increased number of dystrophic microglia in HS-aging; and (4) increased proportion of dystrophic to all microglia in DLB. CONCLUSIONS: We conclude that variations in morphologies among microglial cells, and cells of macrophage lineage, can help guide future work connecting neuroinflammatory mechanisms with specific neurodegenerative disease subtypes.
Asunto(s)
Envejecimiento/patología , Demencia/patología , Hipocampo/citología , Microglía/patología , Esclerosis/patología , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/patología , Antígenos CD/metabolismo , Antígenos de Diferenciación Mielomonocítica/metabolismo , Autopsia , Proteínas de Unión al Calcio , Proteínas de Unión al ADN/metabolismo , Demencia/metabolismo , Femenino , Humanos , Enfermedad por Cuerpos de Lewy/patología , Masculino , Proteínas de Microfilamentos , Microglía/metabolismoRESUMEN
The aging brain is characterized by the simultaneous presence of multiple pathologies, and the prevalence of cerebral multi-morbidity increases with age. To understand the impact of each subtype of pathology and the combined effects of cerebral multi-morbidity on clinical signs and symptoms, large clinico-pathological correlative studies have been performed. However, such studies are often based on semi-quantitative assessment of neuropathological hallmark lesions. Here, we discuss some of the new methods for high-throughput quantitative neuropathological assessment. These methods combine increased quantitative rigor with the added technical capacity of computers and networked analyses. There are abundant new opportunities - with specific techniques that include slide scanners, automated microscopes, and tissue microarrays - and also potential pitfalls. We conclude that quantitative and digital neuropathologic approaches will be key resources to further elucidate cerebral multi-morbidity in the aged brain and also hold the potential for changing routine neuropathologic diagnoses.
RESUMEN
We recommend a new term, "primary age-related tauopathy" (PART), to describe a pathology that is commonly observed in the brains of aged individuals. Many autopsy studies have reported brains with neurofibrillary tangles (NFTs) that are indistinguishable from those of Alzheimer's disease (AD), in the absence of amyloid (Aß) plaques. For these "NFT+/Aß-" brains, for which formal criteria for AD neuropathologic changes are not met, the NFTs are mostly restricted to structures in the medial temporal lobe, basal forebrain, brainstem, and olfactory areas (bulb and cortex). Symptoms in persons with PART usually range from normal to amnestic cognitive changes, with only a minority exhibiting profound impairment. Because cognitive impairment is often mild, existing clinicopathologic designations, such as "tangle-only dementia" and "tangle-predominant senile dementia", are imprecise and not appropriate for most subjects. PART is almost universally detectable at autopsy among elderly individuals, yet this pathological process cannot be specifically identified pre-mortem at the present time. Improved biomarkers and tau imaging may enable diagnosis of PART in clinical settings in the future. Indeed, recent studies have identified a common biomarker profile consisting of temporal lobe atrophy and tauopathy without evidence of Aß accumulation. For both researchers and clinicians, a revised nomenclature will raise awareness of this extremely common pathologic change while providing a conceptual foundation for future studies. Prior reports that have elucidated features of the pathologic entity we refer to as PART are discussed, and working neuropathological diagnostic criteria are proposed.