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1.
Brief Bioinform ; 25(5)2024 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-39226887

RESUMEN

Plasma protein biomarkers have been considered promising tools for diagnosing dementia subtypes due to their low variability, cost-effectiveness, and minimal invasiveness in diagnostic procedures. Machine learning (ML) methods have been applied to enhance accuracy of the biomarker discovery. However, previous ML-based studies often overlook interactions between proteins, which are crucial in complex disorders like dementia. While protein-protein interactions (PPIs) have been used in network models, these models often fail to fully capture the diverse properties of PPIs due to their local awareness. This drawback increases the chance of neglecting critical components and magnifying the impact of noisy interactions. In this study, we propose a novel graph-based ML model for dementia subtype diagnosis, the graph propagational network (GPN). By propagating the independent effect of plasma proteins on PPI network, the GPN extracts the globally interactive effects between proteins. Experimental results showed that the interactive effect between proteins yielded to further clarify the differences between dementia subtype groups and contributed to the performance improvement where the GPN outperformed existing methods by 10.4% on average.


Asunto(s)
Biomarcadores , Proteínas Sanguíneas , Demencia , Aprendizaje Automático , Mapas de Interacción de Proteínas , Humanos , Demencia/metabolismo , Demencia/diagnóstico , Proteínas Sanguíneas/metabolismo , Mapeo de Interacción de Proteínas/métodos , Algoritmos , Biología Computacional/métodos
2.
ACS Chem Neurosci ; 15(19): 3449-3458, 2024 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-39265183

RESUMEN

Peroxisome proliferator-activated receptors (PPARs) have emerged as a promising target for the treatment of various neurodegenerative disorders. Studies have shown that both PPAR α & γ individually modulate various pathophysiological events like neuroinflammation and insulin resistance, which are known to variedly affect neurogenesis. Our study aimed to evaluate the effect of saroglitazar (SGZR), a dual PPAR agonist, on adult neurogenesis and spatial learning and memory, in intracerebroventricular streptozotocin (ICV STZ)-induced dementia in rats. We have found that SGZR at the dose of 4 mg/kg per oral showed significant improvement in learning and memory compared to ICV STZ-treated rats. A substantial increase in neurogenesis was observed in the subventricular zone (SVZ) and the dentate gyrus (DG), as indicated by an increase in the number of 5-bromo-2'-deoxyuridine (BrdU)+ cells, BrdU+ nestin+ cells, and doublecortin (DCX)+cells. Treatment with SGZR also decreased the active form of glycogen synthase kinase 3ß (GSK3ß) and hence enhanced the nuclear translocation of the ß-catenin. Enhanced expression of Wnt transcription factors and target genes indicates that the up-regulation of Wnt signaling might be involved in the observed increase in neurogenesis. Hence, it can be concluded that the SGZR enhances memory functions and adult neurogenesis via the upregulation of Wnt ß-catenin signaling in ICV STZ-treated rats.


Asunto(s)
Demencia , Proteína Doblecortina , Memoria , Neurogénesis , Regulación hacia Arriba , Vía de Señalización Wnt , Animales , Neurogénesis/efectos de los fármacos , Vía de Señalización Wnt/efectos de los fármacos , Vía de Señalización Wnt/fisiología , Ratas , Masculino , Regulación hacia Arriba/efectos de los fármacos , Memoria/efectos de los fármacos , Demencia/metabolismo , Demencia/inducido químicamente , Modelos Animales de Enfermedad , Fenilpropionatos/farmacología , beta Catenina/metabolismo , Ratas Wistar , Estreptozocina
3.
BMC Res Notes ; 17(1): 258, 2024 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-39267193

RESUMEN

OBJECTIVES: We investigated salivary biomarkers of stress, more specifically, cortisol and alpha-amylase, to evaluate effects of individualized music listening (IML) in people with dementia. METHOD: Participants were N = 64 nursing home residents with dementia (meanage = 83.53 ± 7.71 years, 68.8% female). Participants were randomly assigned to either listening to their favorite music every other day for a period of six weeks (intervention), or standard care (control). Using the Saliva Children`s Swab (SCS), saliva was collected before, after, and 20 min after IML sessions at the beginning and end of the intervention period for the analysis of salivary alpha-amylase and cortisol. RESULTS: Using the SCS was feasible in people with dementia. Nevertheless, there was no effect of IML on salivary stress markers. DISCUSSION: Although using SCS was feasible, active patient engagement is required. Future studies need to corroborate findings in larger samples. TRIAL REGISTRATION: German Clinical Trials Register: DRKS00015641, ISRCTN registry: ISRCTN59052178.


Asunto(s)
Biomarcadores , Demencia , Estudios de Factibilidad , Hidrocortisona , Musicoterapia , Saliva , Estrés Psicológico , alfa-Amilasas , Humanos , Femenino , Hidrocortisona/metabolismo , Hidrocortisona/análisis , Masculino , Demencia/metabolismo , Saliva/metabolismo , Saliva/química , Estrés Psicológico/metabolismo , Estrés Psicológico/terapia , Anciano , Biomarcadores/metabolismo , Anciano de 80 o más Años , alfa-Amilasas/metabolismo , alfa-Amilasas/análisis , Proyectos Piloto , Musicoterapia/métodos
4.
Cell ; 187(20): 5753-5774.e28, 2024 Oct 03.
Artículo en Inglés | MEDLINE | ID: mdl-39265576

RESUMEN

The development of successful therapeutics for dementias requires an understanding of their shared and distinct molecular features in the human brain. We performed single-nuclear RNA-seq and ATAC-seq in Alzheimer's disease (AD), frontotemporal dementia (FTD), and progressive supranuclear palsy (PSP), analyzing 41 participants and ∼1 million cells (RNA + ATAC) from three brain regions varying in vulnerability and pathological burden. We identify 32 shared, disease-associated cell types and 14 that are disease specific. Disease-specific cell states represent glial-immune mechanisms and selective neuronal vulnerability impacting layer 5 intratelencephalic neurons in AD, layer 2/3 intratelencephalic neurons in FTD, and layer 5/6 near-projection neurons in PSP. We identify disease-associated gene regulatory networks and cells impacted by causal genetic risk, which differ by disorder. These data illustrate the heterogeneous spectrum of glial and neuronal compositional and gene expression alterations in different dementias and identify therapeutic targets by revealing shared and disease-specific cell states.


Asunto(s)
Enfermedad de Alzheimer , Demencia Frontotemporal , Redes Reguladoras de Genes , Genómica , Neuronas , Análisis de la Célula Individual , Parálisis Supranuclear Progresiva , Humanos , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/patología , Enfermedad de Alzheimer/metabolismo , Demencia Frontotemporal/genética , Demencia Frontotemporal/patología , Demencia Frontotemporal/metabolismo , Parálisis Supranuclear Progresiva/genética , Parálisis Supranuclear Progresiva/metabolismo , Parálisis Supranuclear Progresiva/patología , Genómica/métodos , Neuronas/metabolismo , Neuronas/patología , Anciano , Masculino , Femenino , Encéfalo/metabolismo , Encéfalo/patología , Demencia/genética , Demencia/patología , Demencia/metabolismo , Neuroglía/metabolismo , Neuroglía/patología , Anciano de 80 o más Años , Persona de Mediana Edad , RNA-Seq
5.
Ageing Res Rev ; 99: 102395, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38950867

RESUMEN

The blood brain barrier (BBB) is an indispensable structure that maintains the central nervous system (CNS) microenvironment for a correct neuronal function. It is composed by highly specialized microvessels, surrounded by astrocytes, pericytes, neurons and microglia cells, which tightly control the influx and efflux of substances to the brain parenchyma. During aging, the BBB becomes impaired, and it may contribute to the development of neurodegenerative and neurological disorders including Alzheimer's disease and other dementias. Restoring the BBB can be a strategy to prevent disease onset and development, reducing the symptoms of these conditions. This work critically reviews the major mechanisms underlying BBB breakdown in healthy and unhealthy aging, as well as biomarkers and methodologies that accurately assess its impairment. Complementarily, potential therapeutic targets are discussed as new strategies to restore the normal function of the BBB in aging.


Asunto(s)
Barrera Hematoencefálica , Demencia , Envejecimiento Saludable , Humanos , Barrera Hematoencefálica/metabolismo , Demencia/fisiopatología , Demencia/metabolismo , Envejecimiento Saludable/fisiología , Animales , Envejecimiento/fisiología
6.
Int J Mol Sci ; 25(13)2024 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-39000213

RESUMEN

Dementia and the other neurodegenerative disorders represent a complex pathophysiological process [...].


Asunto(s)
Demencia , Humanos , Demencia/metabolismo , Demencia/etiología , Demencia/patología , Demencia/genética , Animales
7.
Int J Mol Sci ; 25(14)2024 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-39063013

RESUMEN

Ischemic stroke is a leading cause of disability worldwide. While much of post-stroke recovery is focused on physical rehabilitation, post-stroke dementia (PSD) is also a significant contributor to poor functional outcomes. Predictive tools to identify stroke survivors at risk for the development of PSD are limited to brief screening cognitive tests. Emerging biochemical, genetic, and neuroimaging biomarkers are being investigated in an effort to unveil better indicators of PSD. Additionally, acetylcholinesterase inhibitors, NMDA receptor antagonists, dopamine receptor agonists, antidepressants, and cognitive rehabilitation are current therapeutic options for PSD. Focusing on the chronic sequelae of stroke that impair neuroplasticity highlights the need for continued investigative trials to better assess functional outcomes in treatments targeted for PSD.


Asunto(s)
Biomarcadores , Demencia , Accidente Cerebrovascular Isquémico , Humanos , Accidente Cerebrovascular Isquémico/metabolismo , Accidente Cerebrovascular Isquémico/terapia , Demencia/etiología , Demencia/metabolismo
8.
Basic Clin Pharmacol Toxicol ; 135(3): 225-236, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39034736

RESUMEN

Neurolipids comprise a diverse class of bioactive lipids that include molecules capable of activating G protein­coupled receptors, thereby inducing systemic effects that contribute to the maintenance of homeostasis. Dementia, a non­specific brain disorder characterized by a common set of signs and symptoms, usually arises subsequent to brain injuries or diseases and is often associated with the aging process. Individuals affected by dementia suffer from the disruption of several neurotransmitter and neuromodulatory systems, among which neurolipids play an important role, including the endocannabinoid, lysophosphatidic acid and sphingosine 1­phosphate systems. In this review, we present an overview of the most recent and pertinent findings regarding the involvement of these neurolipidic systems in dementia, including data from a wide range of both in vitro and in vivo experiments as well as clinical trials.


Asunto(s)
Demencia , Lisofosfolípidos , Humanos , Demencia/tratamiento farmacológico , Demencia/metabolismo , Lisofosfolípidos/metabolismo , Animales , Esfingosina/análogos & derivados , Esfingosina/metabolismo , Endocannabinoides/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Encéfalo/metabolismo , Encéfalo/efectos de los fármacos , Neurotransmisores/metabolismo
10.
Med Phys ; 51(9): 6002-6019, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38888202

RESUMEN

BACKGROUND: Oxygen extraction fraction (OEF) and deoxyhemoglobin (DoHb) levels reflect variations in cerebral oxygen metabolism in demented patients. PURPOSE: Delineating the metabolic profiles evident throughout different phases of dementia necessitates an integrated analysis of OEF and DoHb levels. This is enabled by leveraging high-resolution quantitative blood oxygenation level dependent (qBOLD) analysis of magnitude images obtained from a multi-echo gradient-echo MRI (mGRE) scan performed on a 3.0 Tesla scanner. METHODS: Achieving superior spatial resolution in qBOLD necessitates the utilization of an mGRE scan with only four echoes, which in turn limits the number of measurements compared to the parameters within the qBOLD model. Consequently, it becomes imperative to discard non-essential parameters to facilitate further analysis. This process entails transforming the qBOLD model into a format suitable for fitting the log-magnitude difference (L-MDif) profiles of the four echo magnitudes present in each brain voxel. In order to bolster spatial specificity, the log-difference qBOLD model undergoes refinement into a representative form, termed as r-qBOLD, particularly when applied to class-averaged L-MDif signals derived through k-means clustering of L-MDif signals from all brain voxels into a predetermined number of clusters. The agreement between parameters estimated using r-qBOLD for different cluster sizes is validated using Bland-Altman analysis, and the model's goodness-of-fit is evaluated using a χ 2 ${\chi ^2}$ -test. Retrospective MRI data of Alzheimer's disease (AD), mild cognitive impairment (MCI), and non-demented patients without neuropathological disorders, pacemakers, other implants, or psychiatric disorders, who completed a minimum of three visits prior to MRI enrolment, are utilized for the study. RESULTS: Utilizing a cohort comprising 30 demented patients aged 65-83 years in stages 4-6 representing mild, moderate, and severe stages according to the clinical dementia rating (CDR), matched with an age-matched non-demented control group of 18 individuals, we conducted joint observations of OEF and DoHb levels estimated using r-qBOLD. The observations elucidate metabolic signatures in dementia based on OEF and DoHb levels in each voxel. Our principal findings highlight the significance of spatial patterns of metabolic profiles (metabolic patterns) within two distinct regimes: OEF levels exceeding the normal range (S1-regime), and OEF levels below the normal range (S2-regime). The S1-regime, accompanied by low DoHb levels, predominantly manifests in fronto-parietal and perivascular regions with increase in dementia severity. Conversely, the S2-regime, accompanied by low DoHb levels, is observed in medial temporal (MTL) regions. Other regions with abnormal metabolic patterns included the orbitofrontal cortex (OFC), medial-orbital prefrontal cortex (MOPFC), hypothalamus, ventro-medial prefrontal cortex (VMPFC), and retrosplenial cortex (RSP). Dysfunction in the OFC and MOPFC indicated cognitive and emotional impairment, while hypothalamic involvement potentially indicated preclinical dementia. Reduced metabolic activity in the RSP suggested early-stage AD related functional abnormalities. CONCLUSIONS: Integrated analysis of OEF and DoHb levels using r-qBOLD reveals distinct metabolic signatures across dementia phases, highlighting regions susceptible to neuronal loss, vascular involvement, and preclinical indicators.


Asunto(s)
Encéfalo , Demencia , Imagen por Resonancia Magnética , Oxígeno , Humanos , Demencia/diagnóstico por imagen , Demencia/metabolismo , Oxígeno/metabolismo , Encéfalo/diagnóstico por imagen , Encéfalo/metabolismo , Anciano , Masculino , Anciano de 80 o más Años , Procesamiento de Imagen Asistido por Computador/métodos , Femenino
11.
Int J Mol Sci ; 25(11)2024 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-38892378

RESUMEN

Dementia, a multifaceted neurological syndrome characterized by cognitive decline, poses significant challenges to daily functioning. The main causes of dementia, including Alzheimer's disease (AD), frontotemporal dementia (FTD), Lewy body dementia (LBD), and vascular dementia (VD), have different symptoms and etiologies. Genetic regulators, specifically non-coding RNAs (ncRNAs) such as microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), are known to play important roles in dementia pathogenesis. MiRNAs, small non-coding RNAs, regulate gene expression by binding to the 3' untranslated regions of target messenger RNAs (mRNAs), while lncRNAs and circRNAs act as molecular sponges for miRNAs, thereby regulating gene expression. The emerging concept of competing endogenous RNA (ceRNA) interactions, involving lncRNAs and circRNAs as competitors for miRNA binding, has gained attention as potential biomarkers and therapeutic targets in dementia-related disorders. This review explores the regulatory roles of ncRNAs, particularly miRNAs, and the intricate dynamics of ceRNA interactions, providing insights into dementia pathogenesis and potential therapeutic avenues.


Asunto(s)
Demencia , Regulación de la Expresión Génica , MicroARNs , ARN Circular , ARN Largo no Codificante , ARN no Traducido , Humanos , Demencia/genética , Demencia/metabolismo , MicroARNs/genética , MicroARNs/metabolismo , ARN Circular/genética , ARN Circular/metabolismo , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , ARN no Traducido/genética , ARN no Traducido/metabolismo , Animales , Biomarcadores , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/metabolismo
12.
Neurotox Res ; 42(3): 28, 2024 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-38842585

RESUMEN

Parkinson's disease with dementia (PDD) is a neurological disorder that clinically and neuropathologically overlaps with Parkinson's disease (PD) and Alzheimer's disease (AD). Although it is assumed that alpha-synuclein ( α -Syn), amyloid beta (A ß ), and the protein Tau might synergistically induce cholinergic neuronal degeneration, presently the pathological mechanism of PDD remains unclear. Therefore, it is essential to delve into the cellular and molecular aspects of this neurological entity to identify potential targets for prevention and treatment strategies. Cholinergic-like neurons (ChLNs) were exposed to rotenone (ROT, 10 µ M) for 24 h. ROT provokes loss of Δ Ψ m , generation of reactive oxygen species (ROS), phosphorylation of leucine-rich repeated kinase 2 (LRRK2 at Ser935) concomitantly with phosphorylation of α -synuclein ( α -Syn, Ser129), induces accumulation of intracellular A ß (iA ß ), oxidized DJ-1 (Cys106), as well as phosphorylation of TAU (Ser202/Thr205), increases the phosphorylation of c-JUN (Ser63/Ser73), and increases expression of proapoptotic proteins TP53, PUMA, and cleaved caspase 3 (CC3) in ChLNs. These neuropathological features resemble those reproduced in presenilin 1 (PSEN1) E280A ChLNs. Interestingly, anti-oxidant and anti-amyloid cannabidiol (CBD), JNK inhibitor SP600125 (SP), TP53 inhibitor pifithrin- α (PFT), and LRRK2 kinase inhibitor PF-06447475 (PF475) significantly diminish ROT-induced oxidative stress (OS), proteinaceous, and cell death markers in ChLNs compared to naïve ChLNs. In conclusion, ROT induces p- α -Syn, iA ß , p-Tau, and cell death in ChLNs, recapitulating the neuropathology findings in PDD. Our report provides an excellent in vitro model to test for potential therapeutic strategies against PDD. Our data suggest that ROT induces a neuropathologic phenotype in ChLNs similar to that caused by the mutation PSEN1 E280A.


Asunto(s)
Neuronas Colinérgicas , Rotenona , Rotenona/toxicidad , Neuronas Colinérgicas/efectos de los fármacos , Neuronas Colinérgicas/metabolismo , Neuronas Colinérgicas/patología , Animales , Enfermedad de Parkinson/patología , Enfermedad de Parkinson/metabolismo , alfa-Sinucleína/metabolismo , Demencia/patología , Demencia/metabolismo , Fenotipo , Especies Reactivas de Oxígeno/metabolismo , Humanos , Células Cultivadas
14.
Ann Nucl Med ; 38(9): 763-773, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38907835

RESUMEN

OBJECTIVE: This study aims to assess the utility of newly developed objective methods for the evaluation of intracranial abnormal amyloid deposition using PET/CT histogram without use of cortical ROI analyses. METHODS: Twenty-five healthy volunteers (HV) and 38 patients with diagnosed or suspected dementia who had undergone 18F-FPYBF-2 PET/CT were retrospectively included in this study. Out of them, 11C-PiB PET/CT had been also performed in 13 subjects. In addition to the conventional methods, namely visual judgment and quantitative analyses using composed standardized uptake value ratio (comSUVR), the PET images were also evaluated by the following new parameters: the skewness and the mode-to-mean ratio (MMR) obtained from the histogram of the brain parenchyma; Top20%-map highlights the areas with high tracer accumulation occupying 20% volume of the total brain parenchymal on the individual's CT images. We evaluated the utility of the new methods using histogram compared with the visual assessment and comSUVR. The results of these new methods between 18F-FPYBF-2 and 11C-PiB were also compared in 13 subjects. RESULTS: In visual analysis, 32, 9, and 22 subjects showed negative, border, and positive results, and composed SUVR in each group were 1.11 ± 0.06, 1.20 ± 0.13, and 1.48 ± 0.18 (p < 0.0001), respectively. Visually positive subjects showed significantly low skewness and high MMR (p < 0.0001), and the Top20%-Map showed the presence or absence of abnormal deposits clearly. In comparison between the two tracers, visual evaluation was all consistent, and the ComSUVR, the skewness, the MMR showed significant good correlation. The Top20%-Maps showed similar pattern. CONCLUSIONS: Our new methods using the histogram of the brain parenchymal accumulation are simple and suitable for clinical practice of amyloid PET, and Top20%-Map on the individual's brain CT can be of great help for the visual assessment.


Asunto(s)
Amiloide , Encéfalo , Tomografía Computarizada por Tomografía de Emisión de Positrones , Humanos , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Masculino , Femenino , Encéfalo/diagnóstico por imagen , Encéfalo/metabolismo , Anciano , Persona de Mediana Edad , Amiloide/metabolismo , Compuestos de Anilina , Estudios Retrospectivos , Procesamiento de Imagen Asistido por Computador/métodos , Adulto , Tiazoles , Anciano de 80 o más Años , Demencia/diagnóstico por imagen , Demencia/metabolismo
15.
Metab Brain Dis ; 39(6): 1051-1063, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38896206

RESUMEN

Oxidative stress from generation of increased reactive oxygen species or has been reported to play an important role in dementia. Oxidative stress due to free radicals of oxygen or reactive oxygen species could be precipitating factors in the etiology of dementia. Apomorphine has been reported to have neuroprotective effects. To monitor memory enhancing and neuroprotective effects of apomorphine, we determined the antioxidant enzymes activities, lipid peroxidation, acetylcholine esterase (AChE) activity in brain and plasma, following repetitive administration of apomorphine in rat model of dementia. Biogenic amine levels were also monitored in hippocampus. Repeated administration of scopolamine was taken as an animal model of dementia. Decreased glutathione peroxidase, superoxide dismutase and catalase activities were observed in these animal models of dementia. While increased lipid peroxidation was also observed in the brain and plasma samples. The results showed significant effects of apomorphine. The activities of antioxidant enzymes displayed increased activities in both brain and plasma. Glutathione peroxidase and catalase activities were found to be significantly higher in brain and plasma of apomorphine treated rats. Superoxide dismutase (SOD) was significantly decreased in plasma of scopolamine injected rats; and a decreased tendency (non-significant) of SOD in brain was also observed. AChE activity in brain and plasma was significantly decreased in scopolamine treated rats. Learning and memory of rats in the present study was assessed by Morris Water Maze (MWM). Short-term memory and long-term memory was impaired significantly in scopolamine treated rats, which was prevented by apomorphine. Moreover, a marked decrease in biogenic amines was also found in the brain of scopolamine treated rats and was reverted in apomorphine treated rats. Results showed that scopolamine-treatment induced memory impairment and induced oxidative stress in rats as compared to saline-treated controls. These impairments were significantly restored by apomorphine administration. In conclusion, our data suggests that apomorphine at the dose of 1 mg/kg could be a potential therapeutic agent to treat dementia and related disorders.


Asunto(s)
Apomorfina , Demencia , Modelos Animales de Enfermedad , Memoria , Fármacos Neuroprotectores , Ratas Wistar , Escopolamina , Animales , Apomorfina/farmacología , Ratas , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/uso terapéutico , Masculino , Demencia/tratamiento farmacológico , Demencia/metabolismo , Demencia/prevención & control , Memoria/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Encéfalo/metabolismo , Encéfalo/efectos de los fármacos , Catalasa/metabolismo , Superóxido Dismutasa/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Acetilcolinesterasa/metabolismo , Glutatión Peroxidasa/metabolismo , Antioxidantes/farmacología , Antioxidantes/uso terapéutico
16.
JAMA Neurol ; 81(8): 845-856, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-38857029

RESUMEN

Importance: An accurate prognosis is especially pertinent in mild cognitive impairment (MCI), when individuals experience considerable uncertainty about future progression. Objective: To evaluate the prognostic value of tau positron emission tomography (PET) to predict clinical progression from MCI to dementia. Design, Setting, and Participants: This was a multicenter cohort study with external validation and a mean (SD) follow-up of 2.0 (1.1) years. Data were collected from centers in South Korea, Sweden, the US, and Switzerland from June 2014 to January 2024. Participant data were retrospectively collected and inclusion criteria were a baseline clinical diagnosis of MCI; longitudinal clinical follow-up; a Mini-Mental State Examination (MMSE) score greater than 22; and available tau PET, amyloid-ß (Aß) PET, and magnetic resonance imaging (MRI) scan less than 1 year from diagnosis. A total of 448 eligible individuals with MCI were included (331 in the discovery cohort and 117 in the validation cohort). None of these participants were excluded over the course of the study. Exposures: Tau PET, Aß PET, and MRI. Main Outcomes and Measures: Positive results on tau PET (temporal meta-region of interest), Aß PET (global; expressed in the standardized metric Centiloids), and MRI (Alzheimer disease [AD] signature region) was assessed using quantitative thresholds and visual reads. Clinical progression from MCI to all-cause dementia (regardless of suspected etiology) or to AD dementia (AD as suspected etiology) served as the primary outcomes. The primary analyses were receiver operating characteristics. Results: In the discovery cohort, the mean (SD) age was 70.9 (8.5) years, 191 (58%) were male, the mean (SD) MMSE score was 27.1 (1.9), and 110 individuals with MCI (33%) converted to dementia (71 to AD dementia). Only the model with tau PET predicted all-cause dementia (area under the receiver operating characteristic curve [AUC], 0.75; 95% CI, 0.70-0.80) better than a base model including age, sex, education, and MMSE score (AUC, 0.71; 95% CI, 0.65-0.77; P = .02), while the models assessing the other neuroimaging markers did not improve prediction. In the validation cohort, tau PET replicated in predicting all-cause dementia. Compared to the base model (AUC, 0.75; 95% CI, 0.69-0.82), prediction of AD dementia in the discovery cohort was significantly improved by including tau PET (AUC, 0.84; 95% CI, 0.79-0.89; P < .001), tau PET visual read (AUC, 0.83; 95% CI, 0.78-0.88; P = .001), and Aß PET Centiloids (AUC, 0.83; 95% CI, 0.78-0.88; P = .03). In the validation cohort, only the tau PET and the tau PET visual reads replicated in predicting AD dementia. Conclusions and Relevance: In this study, tau-PET showed the best performance as a stand-alone marker to predict progression to dementia among individuals with MCI. This suggests that, for prognostic purposes in MCI, a tau PET scan may be the best currently available neuroimaging marker.


Asunto(s)
Disfunción Cognitiva , Demencia , Progresión de la Enfermedad , Tomografía de Emisión de Positrones , Proteínas tau , Humanos , Disfunción Cognitiva/diagnóstico por imagen , Disfunción Cognitiva/metabolismo , Masculino , Femenino , Tomografía de Emisión de Positrones/métodos , Anciano , Proteínas tau/metabolismo , Demencia/diagnóstico por imagen , Demencia/metabolismo , Estudios de Cohortes , Persona de Mediana Edad , Anciano de 80 o más Años , Pronóstico , Estudios Retrospectivos , Imagen por Resonancia Magnética , Valor Predictivo de las Pruebas , Péptidos beta-Amiloides/metabolismo
17.
Neuroimage ; 297: 120695, 2024 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-38942101

RESUMEN

BACKGROUND: The prediction of Alzheimer's disease (AD) progression from its early stages is a research priority. In this context, the use of Artificial Intelligence (AI) in AD has experienced a notable surge in recent years. However, existing investigations predominantly concentrate on distinguishing clinical phenotypes through cross-sectional approaches. This study aims to investigate the potential of modeling additional dimensions of the disease, such as variations in brain metabolism assessed via [18F]-fluorodeoxyglucose positron emission tomography (FDG-PET), and utilize this information to identify patients with mild cognitive impairment (MCI) who will progress to dementia (pMCI). METHODS: We analyzed data from 1,617 participants from the Alzheimer's Disease Neuroimaging Initiative (ADNI) who had undergone at least one FDG-PET scan. We identified the brain regions with the most significant hypometabolism in AD and used Deep Learning (DL) models to predict future changes in brain metabolism. The best-performing model was then adapted under a multi-task learning framework to identify pMCI individuals. Finally, this model underwent further analysis using eXplainable AI (XAI) techniques. RESULTS: Our results confirm a strong association between hypometabolism, disease progression, and cognitive decline. Furthermore, we demonstrated that integrating data on changes in brain metabolism during training enhanced the models' ability to detect pMCI individuals (sensitivity=88.4%, specificity=86.9%). Lastly, the application of XAI techniques enabled us to delve into the brain regions with the most significant impact on model predictions, highlighting the importance of the hippocampus, cingulate cortex, and some subcortical structures. CONCLUSION: This study introduces a novel dimension to predictive modeling in AD, emphasizing the importance of projecting variations in brain metabolism under a multi-task learning paradigm.


Asunto(s)
Encéfalo , Disfunción Cognitiva , Aprendizaje Profundo , Progresión de la Enfermedad , Fluorodesoxiglucosa F18 , Tomografía de Emisión de Positrones , Humanos , Disfunción Cognitiva/diagnóstico por imagen , Disfunción Cognitiva/metabolismo , Femenino , Masculino , Tomografía de Emisión de Positrones/métodos , Anciano , Encéfalo/metabolismo , Encéfalo/diagnóstico por imagen , Fluorodesoxiglucosa F18/farmacocinética , Enfermedad de Alzheimer/diagnóstico por imagen , Enfermedad de Alzheimer/metabolismo , Anciano de 80 o más Años , Demencia/diagnóstico por imagen , Demencia/metabolismo , Inteligencia Artificial , Neuroimagen/métodos
19.
Aging (Albany NY) ; 16(10): 9280-9302, 2024 05 22.
Artículo en Inglés | MEDLINE | ID: mdl-38805248

RESUMEN

Aging is the greatest non-modifiable risk factor for most diseases, including cardiovascular diseases (CVD), which remain the leading cause of mortality worldwide. Robust evidence indicates that CVD are a strong determinant for reduced brain health and all-cause dementia with advancing age. CVD are also closely linked with peripheral and cerebral vascular dysfunction, common contributors to the development and progression of all types of dementia, that are largely driven by excessive levels of oxidative stress (e.g., reactive oxygen species [ROS]). Emerging evidence suggests that several fundamental aging mechanisms (e.g., "hallmarks" of aging), including chronic low-grade inflammation, mitochondrial dysfunction, cellular senescence and deregulated nutrient sensing contribute to excessive ROS production and are common to both peripheral and cerebral vascular dysfunction. Therefore, targeting these mechanisms to reduce ROS-related oxidative stress and improve peripheral and/or cerebral vascular function may be a promising strategy to reduce dementia risk with aging. Investigating how certain lifestyle strategies (e.g., aerobic exercise and diet modulation) and/or select pharmacological agents (natural and synthetic) intersect with aging "hallmarks" to promote peripheral and/or cerebral vascular health represent a viable option for reducing dementia risk with aging. Therefore, the primary purpose of this review is to explore mechanistic links among peripheral vascular dysfunction, cerebral vascular dysfunction, and reduced brain health with aging. Such insight and assessments of non-invasive measures of peripheral and cerebral vascular health with aging might provide a new approach for assessing dementia risk in older adults.


Asunto(s)
Envejecimiento , Encéfalo , Estrés Oxidativo , Humanos , Envejecimiento/fisiología , Encéfalo/metabolismo , Encéfalo/fisiopatología , Enfermedades Vasculares Periféricas/fisiopatología , Especies Reactivas de Oxígeno/metabolismo , Demencia/fisiopatología , Demencia/metabolismo , Enfermedades Cardiovasculares/metabolismo , Enfermedades Cardiovasculares/fisiopatología , Factores de Riesgo , Animales
20.
Genes (Basel) ; 15(5)2024 04 28.
Artículo en Inglés | MEDLINE | ID: mdl-38790197

RESUMEN

Currently, more than 55 million people around the world suffer from dementia, and Alzheimer's Disease and Related Dementias (ADRD) accounts for nearly 60-70% of all those cases. The spread of Alzheimer's Disease (AD) pathology and progressive neurodegeneration in the hippocampus and cerebral cortex is strongly correlated with cognitive decline in AD patients; however, the molecular underpinning of ADRD's causality is still unclear. Studies of postmortem AD brains and animal models of AD suggest that elevated endoplasmic reticulum (ER) stress may have a role in ADRD pathology through altered neurocellular homeostasis in brain regions associated with learning and memory. To study the ER stress-associated neurocellular response and its effects on neurocellular homeostasis and neurogenesis, we modeled an ER stress challenge using thapsigargin (TG), a specific inhibitor of sarco/endoplasmic reticulum Ca2+ ATPase (SERCA), in the induced pluripotent stem cell (iPSC)-derived neural stem cells (NSCs) of two individuals from our Mexican American Family Study (MAFS). High-content screening and transcriptomic analysis of the control and ER stress-challenged NSCs showed that the NSCs' ER stress response resulted in a significant decline in NSC self-renewal and an increase in apoptosis and cellular oxidative stress. A total of 2300 genes were significantly (moderated t statistics FDR-corrected p-value ≤ 0.05 and fold change absolute ≥ 2.0) differentially expressed (DE). The pathway enrichment and gene network analysis of DE genes suggests that all three unfolded protein response (UPR) pathways, protein kinase RNA-like ER kinase (PERK), activating transcription factor-6 (ATF-6), and inositol-requiring enzyme-1 (IRE1), were significantly activated and cooperatively regulated the NSCs' transcriptional response to ER stress. Our results show that IRE1/X-box binding protein 1 (XBP1) mediated transcriptional regulation of the E2F transcription factor 1 (E2F1) gene, and its downstream targets have a dominant role in inducing G1/S-phase cell cycle arrest in ER stress-challenged NSCs. The ER stress-challenged NSCs also showed the activation of C/EBP homologous protein (CHOP)-mediated apoptosis and the dysregulation of synaptic plasticity and neurotransmitter homeostasis-associated genes. Overall, our results suggest that the ER stress-associated attenuation of NSC self-renewal, increased apoptosis, and dysregulated synaptic plasticity and neurotransmitter homeostasis plausibly play a role in the causation of ADRD.


Asunto(s)
Enfermedad de Alzheimer , Estrés del Retículo Endoplásmico , Humanos , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/patología , Células-Madre Neurales/metabolismo , Células-Madre Neurales/patología , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Endorribonucleasas/genética , Endorribonucleasas/metabolismo , Células Madre Pluripotentes Inducidas/metabolismo , Tapsigargina/farmacología , Demencia/genética , Demencia/metabolismo , Demencia/patología , eIF-2 Quinasa/genética , eIF-2 Quinasa/metabolismo , Masculino , Factor de Transcripción Activador 6/metabolismo , Factor de Transcripción Activador 6/genética , Neurogénesis , Proteína 1 de Unión a la X-Box/metabolismo , Proteína 1 de Unión a la X-Box/genética , Femenino , Respuesta de Proteína Desplegada , Factor de Transcripción CHOP
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