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OBJECTIVE: To investigate cortical microstructural measures from diffusion MRI as "neurodegeneration" markers that could improve prognostic accuracy in mild cognitive impairment (MCI). METHODS: The prognostic power of Amyloid/Tau/Neurodegeneration (ATN) biomarkers to predict progression from MCI to AD or non-AD dementia was investigated. Ninety patients underwent clinical evaluation (follow-up interval 32 ± 18 months), lumbar puncture, and MRI. Participants were grouped by clinical stage and cerebrospinal fluid Amyloid and Tau status. T1-structural and diffusion MRI scans were analyzed to calculate diffusion metrics related to cortical columnar structure (AngleR, ParlPD, PerpPD+), cortical mean diffusivity, and fractional anisotropy. Statistical tests were corrected for multiple comparisons. Prognostic power was assessed using receiver operating characteristic (ROC) analysis and related indices. RESULTS: A progressive increase of whole-brain cortical diffusion values was observed along the AD continuum, with all A+ groups showing significantly higher AngleR than A-T-. Investigating clinical progression to dementia, the AT biomarkers together showed good positive predictive value (with 90.91% of MCI A+T+ converting to dementia) but poor negative predictive value (with 40% of MCI A-T- progressing to a mix of AD and non-AD dementias). Adding whole-brain AngleR as an N marker, produced good differentiation between stable and converting MCI A-T- patients (0.8 area under ROC curve) and substantially improved negative predictive value (+21.25%). INTERPRETATION: Results support the clinical utility of cortical microstructure to aid prognosis, especially in A-T- patients. Further work will investigate other complexities of the real-world clinical setting, including A-T+ groups. Diffusion MRI measures of neurodegeneration may complement fluid AT markers to support clinical decision-making.
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BACKGROUND: Predominant right temporal atrophy is a radiological sign usually associated with frontotemporal dementia but this sign can also be present in Alzheimer's disease. Given the overlap of clinical symptoms between the two conditions, it is important to know which characteristics allow them to be differentiated. OBJECTIVES: To compare clinical, neuropsychological and structural magnetic resonance imaging (MRI) data of subjects with prominent right anterior temporal atrophy, depending on the status of amyloid biomarkers. METHODS: Among patients followed in the dementia center of Ospedale Maggiore Policlinico, subjects with right anterior temporal atrophy, defined as grade 3 or 4 on the corresponding visual rating scale, were identified. Only subjects with both an MRI scan and amyloid status available were considered. For selected subjects, data were extracted from clinical and neuropsychological records at initial presentation and at last available follow-up. Two raters applied a protocol of eight visual rating scales to compare brain atrophy and white matter hyperintensities. RESULTS: Of 497 subjects, 17 fulfilled the inclusion criteria: 7 amyloid-positive and 10 amyloid-negative. At initial presentation, executive dysfunction and topographical disorientation were more common in amyloid-positive patients. At follow-up, behavioral symptoms, such as social awkwardness and compulsive attitude, were more frequent in the amyloid-negative patients. Amyloid-positive patients presented an overall worse neuropsychological performance, especially in the language and visuospatial domain, and had higher scores on the right anterior cingulate visual rating scale. CONCLUSION: Patients with predominant right temporal atrophy showed clinical, neuropsychological and radiological differences, depending on the status of amyloid biomarkers.
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Enfermedad de Alzheimer , Demencia Frontotemporal , Humanos , Enfermedad de Alzheimer/complicaciones , Imagen por Resonancia Magnética , Pruebas Neuropsicológicas , Lóbulo Temporal/diagnóstico por imagen , Lóbulo Temporal/patología , Atrofia/patología , BiomarcadoresRESUMEN
Extracellular vesicles (EVs) are nanosized vesicles released by almost all body tissues, representing important mediators of cellular communication, and are thus promising candidate biomarkers for neurodegenerative diseases like Alzheimer's disease (AD). The aim of the present study was to isolate total EVs from plasma and characterize their microRNA (miRNA) contents in AD patients. We isolated total EVs from the plasma of all recruited subjects using ExoQuickULTRA exosome precipitation solution (SBI). Subsequently, circulating total EVs were characterized using Nanosight nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM), and Western blotting. A panel of 754 miRNAs was determined with RT-qPCR using TaqMan OpenArray technology in a QuantStudio 12K System (Thermo Fisher Scientific). The results demonstrated that plasma EVs showed widespread deregulation of specific miRNAs (miR-106a-5p, miR-16-5p, miR-17-5p, miR-195-5p, miR-19b-3p, miR-20a-5p, miR-223-3p, miR-25-3p, miR-296-5p, miR-30b-5p, miR-532-3p, miR-92a-3p, and miR-451a), some of which were already known to be associated with neurological pathologies. A further validation analysis also confirmed a significant upregulation of miR-16-5p, miR-25-3p, miR-92a-3p, and miR-451a in prodromal AD patients, suggesting these dysregulated miRNAs are involved in the early progression of AD.
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Enfermedad de Alzheimer , Exosomas , Vesículas Extracelulares , MicroARNs , Humanos , Enfermedad de Alzheimer/genética , MicroARNs/genética , Biomarcadores , Vesículas Extracelulares/genética , Exosomas/genéticaRESUMEN
In an ever-increasing aged world, Alzheimer's disease (AD) represents the first cause of dementia and one of the first chronic diseases in elderly people. With 55 million people affected, the WHO considers AD to be a disease with public priority. Unfortunately, there are no final cures for this pathology. Treatment strategies are aimed to mitigate symptoms, i.e., acetylcholinesterase inhibitors (AChEI) and the N-Methyl-D-aspartate (NMDA) antagonist Memantine. At present, the best approaches for managing the disease seem to combine pharmacological and non-pharmacological therapies to stimulate cognitive reserve. Over the last twenty years, a number of drugs have been discovered acting on the well-established biological hallmarks of AD, deposition of ß-amyloid aggregates and accumulation of hyperphosphorylated tau protein in cells. Although previous efforts disappointed expectations, a new era in treating AD has been working its way recently. The Food and Drug Administration (FDA) gave conditional approval of the first disease-modifying therapy (DMT) for the treatment of AD, aducanumab, a monoclonal antibody (mAb) designed against Aß plaques and oligomers in 2021, and in January 2023, the FDA granted accelerated approval for a second monoclonal antibody, Lecanemab. This review describes ongoing clinical trials with DMTs and non-pharmacological therapies. We will also present a future scenario based on new biomarkers that can detect AD in preclinical or prodromal stages, identify people at risk of developing AD, and allow an early and curative treatment.
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Enfermedad de Alzheimer , Estados Unidos , Humanos , Anciano , Enfermedad de Alzheimer/metabolismo , Acetilcolinesterasa , Péptidos beta-Amiloides/metabolismo , Memantina/uso terapéutico , Memantina/farmacología , Anticuerpos Monoclonales/uso terapéuticoRESUMEN
Background: Perivascular spaces (PVS) are fluid-filled compartments that dilate in response to many different conditions. A high burden of enlarged PVS (EPVS) in the centrum semiovale (CSO) has been linked to neurodegeneration. Moreover, an increase in cerebrospinal fluid (CSF) levels of aquaporin-4 (AQP4), a water channel expressed on PVS-bounding astrocytes, has been described in patients with neurodegenerative dementia. Our aim was to investigate the relationship between neurodegenerative diseases and two putative glymphatic system biomarkers: AQP4 and EPVS. Methods: We included 70 individuals, 54 patients with neurodegenerative diseases and 16 subjects with non-degenerative conditions. EPVS were visually quantified on MRI-scans applying Paradise's scale. All subjects underwent lumbar puncture for the measurement of AQP4 levels in the cerebrospinal fluid (CSF). CSF levels of amyloid-ß-1-42, phosphorylated and total tau (tTau) were also measured. Linear regression analyses were adjusted for age, sex, education and disease duration, after excluding outliers. Results: Cerebrospinal fluid (CSF)-AQP4 levels were independent predictors of total (ß = 0.28, standard error [SE] = 0.08, p = 0.001), basal ganglia (ß = 0.20, SE = 0.08, p = 0.009) and centrum semiovale EPVS (ß = 0.37, SE = 0.12, p = 0.003). tTau levels predicted CSO-EPVS (ß = 0.30, SE = 0.15, p = 0.046). Moreover, increased levels of AQP4 were strongly associated with higher levels of tTau in the CSF (ß = 0.35, SE = 0.13, p = 0.008). Conclusion: We provide evidence that CSO-EPVS and CSF-AQP4 might be clinically meaningful biomarkers of glymphatic dysfunction and associated neurodegeneration.
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BACKGROUND: The longevity gene Klotho (KL) was recently associated with neurodegenerative diseases including Alzheimer's disease (AD). Its role in the brain has not been completely elucidated, although evidence suggests that KL-VS heterozygosity is associated with a reduced risk of AD in Apolipoprotein E É4 carriers. Conversely, no data about genetic association with frontotemporal dementia (FTD) are available so far. OBJECTIVE: To investigate the involvement of KL in AD and FTD by the determination of the genetic frequency of KL-VS variant and the expression analysis of KL gene. METHODS: A population consisting of 438 patients and 240 age-matched controls was enrolled for the study. KL-VS and APOE genotypes were assessed by allelic discrimination through a QuantStudio 12K system. KL gene expression analysis was performed in a restricted cohort of patients consisting of 43 AD patients, 41 FTD patients and 19 controls. KL gene expression was assessed in peripheral blood mononuclear cells with specific TaqMan assay. Statistical analysis was performed using GraphPad 9 Prims software. RESULTS: KL-VS frequency was comparable to the ones found in literature and no differences were found in both allelic and genotypic frequencies between patients and controls were found. Conversely, KL expression levels were significantly lower in AD and FTD patients compared with controls (mean fold regulation - 4.286 and - 6.561 versus controls in AD and FTD, respectively, pâ=â0.0037). CONCLUSION: This is the first study investigating KL in FTD. We showed a decreased expression of the gene in AD and FTD, independent of the genotype, suggesting a role of Klotho in common steps during neurodegeneration.
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Enfermedad de Alzheimer , Demencia Frontotemporal , Humanos , Enfermedad de Alzheimer/genética , Demencia Frontotemporal/genética , Expresión Génica , Genotipo , Leucocitos MononuclearesRESUMEN
OBJECTIVE: This study aimed to evaluate the experience with telemedicine in patients with cognitive impairments and their caregivers. METHODS: We conducted a survey-based study of patients who completed neurological consultation via video link between January and April 2022. RESULTS: A total of 62 eligible neurological video consultations were conducted for the following categories of patients: Alzheimer's disease (33.87%), amnesic mild cognitive impairment (24.19%), frontotemporal dementia (17.74%), Lewy body dementia (4.84%), mixed dementia (3.23%), subjective memory disorders (12.90%), non-amnesic mild cognitive impairment (1.61%), and multiple system atrophy (1.61%). The survey was successfully completed by 87.10% of the caregivers and directly by the patients in 12.90% of cases. Our data showed positive feedback regarding the telemedicine experience; both caregivers and patients reported that they found neurological video consultation useful (caregivers: 87.04%, 'very useful'; patients: 87.50%, 'very useful') and were satisfied overall (caregivers: 90.74%, 'very satisfied'; patients: 100%, 'very satisfied'). Finally, all caregivers (100%) agreed that neurological video consultation was a useful tool to reduce their burden (Visual Analogue Scale mean ± SD: 8.56 ± 0.69). CONCLUSIONS: Telemedicine is well received by patients and their caregivers. However, successful delivery incorporates support from staff and care partners to navigate technologies. The exclusion of older adults with cognitive impairment in developing telemedicine systems may further exacerbate access to care in this population. Adapting technologies to the needs of patients and their caregivers is critical for the advancement of accessible dementia care through telemedicine.
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Enfermedad de Alzheimer , Disfunción Cognitiva , Telemedicina , Humanos , Anciano , Disfunción Cognitiva/diagnóstico , Disfunción Cognitiva/terapia , Disfunción Cognitiva/epidemiología , Enfermedad de Alzheimer/psicología , Cuidadores/psicología , Derivación y Consulta , TeléfonoRESUMEN
BACKGROUND: Brain iron homeostasis is disrupted in neurodegeneration and areas of iron overload partially overlap with regions of amyloid and tau burden in Alzheimer's disease (AD). Previous studies demonstrated alterations in brain iron accumulation in AD using quantitative susceptibility mapping (QSM). OBJECTIVE: Here, we investigate brain alterations of QSM values in AD and non-AD patients as compared to healthy controls (HC) in the superior temporal sulcus and its banks (BANKSSTS), one of the top AD-affected regions. METHODS: Thirty-four patients who underwent brain MRI including a multi-echo gradient-echo sequence were subdivided into AD (nâ=â19) and non-AD (nâ=â15) groups according to their clinical profile, CSF (Aß42/40) and/or amyloid-PET status. Ten HC were also included. QSM values were extracted from left and right BANKSSTS and compared among groups. Correlation and binomial regression analyses between QSM values and CSF-AD biomarkers were conducted. RESULTS: QSM in left BANKSSTS was significantly different among groups (pâ=â0.003, Hâ=â11.40), being higher in AD. QSM values in left BANKSSTS were correlated with Aß42 (rho -0.55, pâ=â0.005), Aß42/40 (rho -0.66, pâ<â0.001), pTau (rho 0.63, pâ<â0.001), tTau (rho 0.56, pâ=â0.005), tTau/Aß42 (rho 0.68, pâ<â0.001) and pTau/Aß42 (rho 0.71, pâ<â0.001). No correlations between QSM values and amyloid-PET SUVR in the left BANKSSTS were found. QSM values in left BANKSSTS showed good accuracy in discriminating AD (AUCâ=â0.80, CI95 % [0.66-0.93]). Higher QSM values were independent predictors of Aß42 (Bâ=â0.63, pâ=â0.032), Aß42/40 (Bâ=â0.81, pâ=â0.028), pTau (Bâ=â0.96, pâ=â0.046), tTau (Bâ=â0.55, pâ=â0.027), and tTau/Aß42 (Bâ=â1.13, pâ=â0.042) positivity. CONCLUSION: Our preliminary data support the potential role of increased QSM values in the left BANKSSTS as an auxiliary imaging biomarker in AD diagnosis.
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Enfermedad de Alzheimer , Humanos , Enfermedad de Alzheimer/diagnóstico por imagen , Péptidos beta-Amiloides , Proteínas tau , Lóbulo Temporal/diagnóstico por imagen , Hierro , Biomarcadores , Fragmentos de PéptidosRESUMEN
Alzheimer's Disease is the most common form of dementia; its key pathological findings include the deposition of extracellular-neurotoxic-plaques composed of amyloid-beta (Ab). AD-pathogenesis involves mechanisms that operate outside the brain, and new researches indicate that peripheral inflammation is an early event in the disease. Herein, we focus on a receptor known as triggering-receptor-expressed-on-myeloid-cells2 (TREM2), which promotes the optimal immune cells function required to attenuate AD-progression and is, therefore, a potential target as peripheral diagnostic and prognostic-biomarker for Alzheimer's Disease. The objective of this exploratory study was to analyze: (1) soluble-TREM2 (sTREM2) plasma and cerebrospinal fluid concentration, (2) TREM2-mRNA, (3) the percentage of TREM2-expressing monocytes, and (4) the concentration of miR-146a-5p and miR-34a-5p suspected to influence TREM2 transcription. Experiments were performed on PBMC collected by 15AD patients and 12age-matched healthy controls that were unstimulated or treated in inflammatory (LPS) conditions and Ab42 for 24 h; Aß42-phagocytosis was also analyzed by AMNIS FlowSight. Results although preliminary, due to limitations by the small sample-size, showed that in AD compared to HC: TREM2 expressing monocytes were reduced, plasma sTREM2 concentration and TREM2-mRNA were significantly upregulated and Ab42-phagocytosis was diminished (for all p < 0.05). miR-34a-5p expression was reduced (p = 0.02) as well in PBMC of AD, and miR-146 was only observed in AD cells (p = 0.0001).
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Enfermedad de Alzheimer , MicroARNs , Humanos , Enfermedad de Alzheimer/patología , Leucocitos Mononucleares/patología , Péptidos beta-Amiloides/líquido cefalorraquídeo , Fagocitosis , MicroARNs/genética , Glicoproteínas de Membrana/genética , Receptores Inmunológicos/genéticaRESUMEN
OBJECTIVES: To investigate the normal-appearing white matter (NAWM) susceptibility in a cohort of newly diagnosed multiple sclerosis (MS) patients and to evaluate possible correlations between NAWM susceptibility and disability progression. METHODS: Fifty-nine patients with a diagnosis of MS (n = 53) or clinically isolated syndrome (CIS) (n = 6) were recruited and followed up. All participants underwent neurological examination, blood sampling for serum neurofilament light chain (sNfL) level assessment, lumbar puncture for the quantification of cerebrospinal fluid (CSF) ß-amyloid1-42 (Aß) levels, and brain MRI. T2-weighted scans were used to quantify white matter (WM) lesion loads. For each scan, we derived the NAWM volume fraction and the WM lesion volume fraction. Quantitative susceptibility mapping (QSM) of the NAWM was calculated using the susceptibility tensor imaging (STI) suite. Susceptibility maps were computed with the STAR algorithm. RESULTS: Primary progressive patients (n = 9) showed a higher mean susceptibility value in the NAWM than relapsing-remitting (n = 44) and CIS (n = 6) (p = 0.01 and p = 0.02). Patients with a higher susceptibility in the NAWM showed increased sNfL concentration (ρ = 0.38, p = 0.004) and lower CSF Aß levels (ρ = -0.34, p = 0.009). Mean NAWM susceptibility turned out to be a predictor of the expanded disability status scale (EDSS) worsening at follow-up (ß = 0.41, t = 2.66, p = 0.01) and of the MS severity scale (MSSS) (ß = 0.38, t = 2.43, p = 0.019). CONCLUSIONS: QSM in the NAWM seems to predict the EDSS increment over time. This finding might provide evidence on the role of QSM in identifying patients with an increased risk of early disability progression. KEY POINTS: ⢠NAWM-QSM is higher in PPMS patients than in RRMS. ⢠NAWM-QSM seems to be a predictor of EDSS worsening over time. ⢠Patients with higher NAWM-QSM show increased sNfL concentration and lower CSF Aß levels.
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Enfermedades Desmielinizantes , Esclerosis Múltiple Recurrente-Remitente , Esclerosis Múltiple , Sustancia Blanca , Humanos , Esclerosis Múltiple/diagnóstico por imagen , Esclerosis Múltiple/patología , Sustancia Blanca/diagnóstico por imagen , Sustancia Blanca/patología , Imagen por Resonancia Magnética/métodos , Neuroimagen , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Esclerosis Múltiple Recurrente-Remitente/patologíaRESUMEN
Frontotemporal Dementia (FTD) represents a highly heritable neurodegenerative disorder. Most of the heritability is caused by autosomal dominant mutations in the Microtubule-Associated Protein Tau (MAPT), Progranulin (GRN), and the pathologic exanucleotide expansion of C9ORF72 genes. At the pathological level, either the tau or the TAR DNA-binding protein (TDP-43) account for almost all cases of FTD. Pathogenic mechanisms are just arising, and the emerging role of non-coding RNAs (ncRNAs), such as microRNAs (miRNA) and long non-coding RNAs (lncRNAs), have become increasingly evident. Using specific arrays, an exploratory analysis testing the expression levels of 84 miRNAs and 84 lncRNAs has been performed in a population consisting of 24 genetic FTD patients (eight GRN, eight C9ORF72, and eight MAPT mutation carriers), eight sporadic FTD patients, and eight healthy controls. The results showed a generalized ncRNA downregulation in patients carrying GRN and C9ORF72 when compared with the controls, with statistically significant results for the following miRNAs: miR-155-5p (Fold Change FC: 0.45, p = 0.037 FDR = 0.52), miR-15a-5p (FC: 0.13, p = 0.027, FDR = 1), miR-222-3p (FC: 0.13, p = 0.027, FDR = 0.778), miR-140-3p (FC: 0.096, p = 0.034, FRD = 0.593), miR-106b-5p (FC: 0.13, p = 0.02, FDR = 0.584) and an upregulation solely for miR-124-3p (FC: 2.1, p = 0.01, FDR = 0.893). Conversely, MAPT mutation carriers showed a generalized robust upregulation in several ncRNAs, specifically for miR-222-3p (FC: 22.3, p = 7 × 10-6, FDR = 0.117), miR-15a-5p (FC: 30.2, p = 0.008, FDR = 0.145), miR-27a-3p (FC: 27.8, p = 6 × 10-6, FDR = 0.0005), miR-223-3p (FC: 18.9, p = 0.005, FDR = 0.117), and miR-16-5p (FC: 10.9, p = 5.26 × 10-5, FDR = 0.001). These results suggest a clear, distinctive pattern of dysregulation among ncRNAs and specific enrichment gene pathways between mutations associated with the TDP-43 and tau pathologies. Nevertheless, these preliminary results need to be confirmed in a larger independent cohort.
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Demencia Frontotemporal , MicroARNs , Enfermedad de Pick , ARN Largo no Codificante , Humanos , Proteína C9orf72/genética , Demencia Frontotemporal/metabolismo , MicroARNs/genética , Mutación , Enfermedad de Pick/genética , Progranulinas/genética , ARN Largo no Codificante/genética , Proteínas tau/genéticaRESUMEN
Recently, a fully automated instrument for the detection of the Cerebrospinal Fluid (CSF) biomarker for Alzheimer's disease (AD) (low concentration of Amyloid-beta 42 (Aß42), high concentration of total tau (T-tau) and Phosphorylated-tau (P-tau181)), has been implemented, namely CLEIA. We conducted a comparative analysis between ELISA and CLEIA methods in order to evaluate the analytical precision and the diagnostic performance of the novel CLEIA system on 111 CSF samples. Results confirmed a robust correlation between ELISA and CLEIA methods, with an improvement of the accuracy with the new CLEIA methodology in the detection of the single biomarkers and in their ratio values. For Aß42 regression analysis with Passing−Bablok showed a Pearson correlation coefficient r = 0.867 (0.8120; 0.907% 95% CI p < 0.0001), T-tau analysis: r = 0.968 (0.954; 0.978% 95% CI p < 0.0001) and P-tau181: r = 0.946 (0.922; 0.962 5% 95% CI p < 0.0001). The overall ROC AUC comparison between ROC in ELISA and ROC in CLEIA confirmed a more accurate ROC AUC with the new automatic method: T-tau AUC ELISA = 0.94 (95% CI 0.89; 0.99 p < 0.0001) vs. AUC CLEIA = 0.95 (95% CI 0.89; 1.00 p < 0.0001), and P-tau181 AUC ELISA = 0.91 (95% CI 0.85; 0.98 p < 0.0001) vs. AUC CLEIA = 0.98 (95% CI 0.95; 1.00 p < 0.0001). The performance of the new CLEIA method in automation is comparable and, for tau and P-tau181, even better, as compared with standard ELISA. Hopefully, in the future, automation could be useful in clinical diagnosis and also in the context of clinical studies.
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Aquaporin-4 (AQP4) is a channel protein that plays a fundamental role in glymphatic system, a newly described pathway for fluid exchange in the central nervous system, as well as a central figure in a fascinating new theory for the pathophysiology of neurodegenerative diseases such as Alzheimer's disease (AD) and frontotemporal dementia (FTD). In this study, cerebrospinal fluid (CSF) concentration of AQP4, amyloid-ß, total tau and P-tau were determined in 103 CSF samples from patients affected by neurodegenerative dementias (AD and FTD) or psychiatric diseases and 21 controls. Significantly higher levels of AQP4 were found in AD and FTD patients compared to subjects not affected by neurodegenerative diseases, and a significant, positive correlation between AQP4 and total tau levels was found. This evidence may pave the way for future studies focused on the role of this channel protein in the clinical assessment of the glymphatic function and degree of neurodegeneration.
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Enfermedad de Alzheimer , Acuaporina 4 , Demencia Frontotemporal , Sistema Glinfático , Enfermedad de Alzheimer/líquido cefalorraquídeo , Enfermedad de Alzheimer/metabolismo , Acuaporina 4/líquido cefalorraquídeo , Acuaporina 4/metabolismo , Demencia Frontotemporal/líquido cefalorraquídeo , Demencia Frontotemporal/metabolismo , Sistema Glinfático/metabolismo , Humanos , Enfermedades Neurodegenerativas/líquido cefalorraquídeo , Enfermedades Neurodegenerativas/metabolismo , Proteínas tau/líquido cefalorraquídeo , Proteínas tau/metabolismoRESUMEN
BACKGROUND: Aß42 deposition plays a pivotal role in AD pathogenesis by inducing the activation of microglial cells and neuroinflammation. This process is antagonized by microglia-mediated clearance of Aß plaques. Activation of the NLRP3 inflammasome is involved in neuroinflammation and in the impairments of Aß-plaque clearance. On the other hand, stavudine (D4T) downregulates the NLRP3 inflammasome and stimulates autophagy-mediated Aß-clearing in a THP-1-derived macrophages. METHODS: We explored the effect of D4T on Aß autophagy in PBMC from AD patients that were primed with LPS and stimulated with Aß oligomers in the absence/presence of D4T. We analyzed the NLRP3 activity by measuring NLRP3-ASC complex formation by AMNIS FlowSight and pro-inflammatory cytokine (IL-1ß, IL-18 and Caspase-1) production by ELISA. The phosphorylation status of p38, ERK, AKT, p70, and the protein expression of CREB, LAMP2A, beclin-1, Caspase-3 and Bcl2 were analyzed by Western blot. RESULTS: Data showed that D4T: (1) downregulates NLRP3 inflammasome activation and the production of down-stream pro-inflammatory cytokines in PBMC; (2) stimulates the phosphorylation of AKT, ERK and p70 as well as LAMP2A, beclin-1 and Bcl2 expression and reduces Caspase-3 expression, suggesting an effect of this compound on autophagy; (3) increases phospho-CREB, which is a downstream target of p-ERK and p-AKT, inducing anti-inflammatory cytokine production and resulting in a possible decrease of Aß-mediated cytotoxicity; and (4) reduces the phosphorylation of p38, a protein involved in the production of pro-inflammatory cytokines and tau hyperphosphorylation. CONCLUSIONS: D4T reduces the activation of the NLRP3 inflammasome, and it might stimulate autophagy as well as the molecular mechanism that modulates Aß cytotoxicity, and D4T might reduce inflammation in the cells of AD patients. It could be very interesting to check the possible beneficial effects of D4T in the clinical scenario.
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Enfermedad de Alzheimer , Inflamasomas , Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/metabolismo , Autofagia , Beclina-1 , Caspasa 3 , Citocinas/metabolismo , Humanos , Inflamasomas/metabolismo , Leucocitos Mononucleares/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Placa Amiloide , Proteínas Proto-Oncogénicas c-akt , Proteínas Proto-Oncogénicas c-bcl-2 , EstavudinaRESUMEN
BACKGROUND: Slowly expanding lesions (SELs) are MRI markers of chronic active lesions in multiple sclerosis (MS). T1-hypointense black holes, and reductions in magnetization transfer ratio (MTR) are pathologically correlated with myelin and axonal loss. While all associated with progressive MS, the relationship between these lesion's metrics and clinical outcomes in relapse-onset MS has not been widely investigated. OBJECTIVES: To explore the relationship of SELs with T1-hypointense black holes, and longitudinal T1 intensity contrast ratio and MTR, their correlation to brain volume, and their contribution to MS disability in relapse-onset patients. METHODS: 135 patients with relapsing-remitting MS (RRMS) were studied with clinical assessments and brain MRI (T2/FLAIR and T1-weighted scans at 1.5/3 T) at baseline and two subsequent follow-ups; a subset of 83 patients also had MTR acquisitions. Early-onset patients were defined when the baseline disease duration was ≤ 5 years (n = 85). SELs were identified using deformation field maps from the manually segmented baseline T2 lesions and differentiated from the non-SELs. Persisting black holes (PBHs) were defined as a subset of T2 lesions with a signal below a patient-specific grey matter T1 intensity in a semi-quantitative manner. SELs, PBH counts, and brain volume were computed, and their associations were assessed through Spearman and Pearson correlation. Clusters of patients according to low (up to 2), intermediate (3 to 10), or high (more than 10) SEL counts were determined with a Gaussian generalised mixture model. Mixed-effects and logistic regression models assessed volumes, T1 and MTR within SELs, and their correlation with Expanded Disability Status Scale (EDSS) and confirmed disability progression (CDP). RESULTS: Mean age at study onset was 35.5 years (73% female), disease duration 5.5 years and mean time to last follow-up 6.5 years (range 1 to 12.5); median baseline EDSS 1.5 (range 0 to 5.5) and a mean EDSS change of 0.31 units at final follow-up. Among 4007 T2 lesions, 27% were classified as SELs and 10% as PBHs. Most patients (n = 65) belonged to the cluster with an intermediate SEL count (3 to 10 SELs). The percentage of PBHs was higher in SELs than non-SELs (up to 61% vs 44%, p < 0.001) and within-patient SEL volumes positively correlated with PBH volumes (r = 0.53, p < 0.001). SELs showed a decrease in T1 intensity over time (beta = -0.004, 95%CI -0.005 to -0.003, p < 0.001), accompanied by lower cross-sectional baseline and follow-up MTR. In mixed-effects models, EDSS worsening was predicted by the SEL log-volumes increase over time (beta = 0.11, 95%CI 0.03 to 0.20, p = 0.01), which was confirmed in the sub-cohort of patients with early onset MS (beta = 0.14, 95%CI 0.04 to 0.25, p = 0.008). In logistic regressions, a higher risk for CDP was associated with SEL volumes (OR = 5.15, 95%CI 1.60 to 16.60, p = 0.006). CONCLUSIONS: SELs are associated with accumulation of more destructive pathology as indicated by an association with PBH volume, longitudinal reduction in T1 intensity and MTR. Higher SEL volumes are associated with clinical progression, while lower ones are associated with stability in relapse-onset MS.
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Esclerosis Múltiple Recurrente-Remitente , Esclerosis Múltiple , Femenino , Humanos , Masculino , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Estudios Transversales , Imagen por Resonancia Magnética , Esclerosis Múltiple/patología , Esclerosis Múltiple Recurrente-Remitente/diagnóstico por imagen , Esclerosis Múltiple Recurrente-Remitente/patología , RecurrenciaRESUMEN
BACKGROUND AND OBJECTIVES: Multiple sclerosis (MS) is an autoimmune disease confined in the CNS, and its course is frequently subtle and variable. Therefore, predictive biomarkers are needed. In this scenario, we conducted a systematic review and meta-analysis to evaluate the reliability of chitinase 3-like 1 as a biomarker of MS. METHODS: Research through the main scientific databases (PubMed, Scopus, Web of Science, and Cochrane Library) published from January 2010 to December 2020 was performed using the following keywords: "chitinase 3-like 1 and multiple sclerosis" and "YKL40 and multiple sclerosis." Articles were selected according to the 2020 updated Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines by 2 authors independently, and data were extracted; 20 of the 90 studies screened were included in the meta-analysis. The main efficacy measure was represented by the standardized mean difference of CSF and blood CHI3L1 levels; Review Manager version 5.4 and R software applications were used for analysis. RESULTS: Higher levels of CHI3L1 were found in CSF of 673 patients with MS compared with 336 healthy controls (size-weighted mean difference [SMD] 50.88; 95% CI = 44.98-56.79; p < 0.00001) and in 461 patients with MS than 283 patients with clinically isolated syndrome (CIS) (SMD 28.18; 95% CI = 23.59-32.76; p < 0.00001). Mean CSF CHI3L1 levels were significantly higher in 561 converting than 445 nonconverting CIS (SMD 30.6; 95% CI = 28.31-32.93; p < 0.00001). CSF CHI3L1 levels were significantly higher in patients with primary progressive MS (PPMS) than in patients with relapsing-remitting MS (RRMS) (SMD 43.15; 95% CI = 24.41-61.90; p < 0.00001) and in patients with secondary progressive MS (SMD 41.86 with 95% CI = 32.39-51.33; p < 0.00001). CSF CHI3L1 levels in 407 patients with MS during remission phase of disease were significantly higher than those in 395 patients with MS with acute relapse (SMD 10.48; 95% CI = 08.51-12.44; p < 0.00001). The performances of CHI3L1 in blood for differentiating patients with MS from healthy controls were not significant (SMD 0.48; 95% CI = -1.18 to 2.14; p: 0.57). DISCUSSION: CSF levels of CHI3L1 have a strong correlation with the MS pathologic course, in particular with the mechanism of progression of the disease; it helps to distinguish the PPMS from the RRMS. The potential role of CHI3L1 in serum needs to be further studied in the future.
Asunto(s)
Quitinasas , Esclerosis Múltiple Crónica Progresiva , Esclerosis Múltiple , Biomarcadores , Proteína 1 Similar a Quitinasa-3 , Humanos , Esclerosis Múltiple/diagnóstico , Reproducibilidad de los ResultadosRESUMEN
Cognitive deficits strongly affect the quality of life of patients with multiple sclerosis (MS). However, no cognitive MS biomarkers are currently available. Extracellular vesicles (EVs) contain markers of parental cells and are able to pass from the brain into blood, representing a source of disease biomarkers. The aim of this study was to investigate whether small non-coding microRNAs (miRNAs) targeting synaptic genes and packaged in plasma EVs may reflect cognitive deficits in MS patients. Total EVs were precipitated by Exoquick from the plasma of twenty-six cognitively preserved (CP) and twenty-three cognitively impaired (CI) MS patients belonging to two independent cohorts. Myeloid EVs were extracted by affinity capture from total EVs using Isolectin B4 (IB4). Fourteen miRNAs targeting synaptic genes were selected and measured by RT-PCR in both total and myeloid EVs. Myeloid EVs from CI patients expressed higher levels of miR-150-5p and lower levels of let-7b-5p compared to CP patients. Stratification for progressive MS (PMS) and relapsing-remitting MS (RRMS) and correlation with clinical parameters suggested that these alterations might be attributable to cognitive deficits rather than disease progression. This study identifies miR-150-5p and let-7b-5p packaged in blood myeloid EVs as possible biomarkers for cognitive deficits in MS.
Asunto(s)
Vesículas Extracelulares , MicroARNs , Esclerosis Múltiple , Biomarcadores , Cognición , Vesículas Extracelulares/genética , Humanos , MicroARNs/genética , Esclerosis Múltiple/genética , Calidad de VidaRESUMEN
Natalizumab (NTZ) can reactivate human polyomavirus John Cunningham polyomavirus (JCPyV) latent infection and lead to progressive multifocal leukoencephalopathy (PML). NTZ modulates the expression of microRNA-126-3p (miR-126-3p) and its target genes, Spi-B, POU2AF1, and vascular cell adhesion molecule-1 (VCAM-1); Spi-B protein binds the JCPyV regulatory region, initiating early gene transcription. This paper is aimed to evaluate the miR-126-3p and soluble (s)VCAM-1 concentration, Spi-B/POU2AF1 gene expression, and JCPyV activity in patients with multiple sclerosis (MS) before and during 2-years NTZ. Serum miR-126-3p and sVCAM-1 concentration was measured before NTZ and after 1, 12, and 24 months of treatment in 22 MS subjects, 1 patient who developed PML, and 29 healthy controls (HCs). The Spi-B and POU2AF1 expression in blood was analyzed at baseline and at month 24 in 13 patients with MS; results were clusterized based on JCPyV activity. miR-126-3p was significantly downregulated in MS before and during NTZ but was greatly increased in the PML patient. sVCAM-1 concentration was comparable in MS and HCs, and was reduced by NTZ in MS and PML. Spi-B/POU2AF1 expression was significantly increased in MS at baseline and was upregulated by NTZ, particularly in JCPyV-infected patients in whom JCPyV reactivation was detected. Taken together, the results suggest that the modulation of the miR-126-3p/POU2AF1/Spi-B axis associates with JCPyV activity in NTZ-treated patients with MS.
RESUMEN
PURPOSE: Positron emission tomography (PET) with amyloid tracers (amy-PET) allows the quantification of pathological amyloid deposition in the brain tissues, including the white matter (WM). Here, we evaluate amy-PET uptake in WM lesions (WML) and in the normal-appearing WM (NAWM) of patients with Alzheimer's disease (AD) and non-AD type of dementia. METHODS: Thirty-three cognitively impaired subjects underwent brain magnetic resonance imaging (MRI), Aß1-42 (Aß) determination in the cerebrospinal fluid (CSF) and amy-PET. Twenty-three patients exhibiting concordant results in both CSF analysis and amy-PET for cortical amyloid deposition were recruited and divided into two groups, amyloid positive (A+) and negative (A-). WML quantification and brain volumes' segmentation were performed. Standardized uptake values ratios (SUVR) were calculated in the grey matter (GM), NAWM and WML on amy-PET coregistered to MRI images. RESULTS: A+ compared to A- showed a higher WML load (p = 0.049) alongside higher SUVR in all brain tissues (p < 0.01). No correlations between CSF Aß levels and WML and NAWM SUVR were found in A+, while, in A-, CSF Aß levels were directly correlated to NAWM SUVR (p = 0.04). CSF Aß concentration was the only predictor of NAWM SUVR (adj R2 = 0.91; p = 0.04) in A-. In A+ but not in A- direct correlations were identified between WM and GM SUVR (p < 0.01). CONCLUSIONS: Our data provide evidence on the role of amy-PET in the assessment of microstructural WM injury in non-AD dementia, whereas amy-PET seems less suitable to assess WM damage in AD patients due to a plausible amyloid accrual therein.