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1.
Alzheimers Dement ; 2024 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-38940303

RESUMEN

INTRODUCTION: Blood-based biomarkers are a cost-effective and minimally invasive method for diagnosing the early and preclinical stages of amyloid positivity (AP). Our study aims to investigate our novel immunoprecipitation-immunoassay (IP-IA) as a test for predicting cognitive decline. METHODS: We measured levels of amyloid beta (Aß)X-40 and AßX-42 in immunoprecipitated eluates from the DELCODE cohort. Receiver-operating characteristic (ROC) curves, regression analyses, and Cox proportional hazard regression models were constructed to predict AP by Aß42/40 classification in cerebrospinal fluid (CSF) and conversion to mild cognitive impairment (MCI) or dementia. RESULTS: We detected a significant correlation between AßX-42/X-40 in plasma and CSF (r = 0.473). Mixed-modeling analysis revealed a substantial prediction of AßX-42/X-40 with an area under the curve (AUC) of 0.81 for AP (sensitivity: 0.79, specificity: 0.74, positive predictive value [PPV]: 0.71, negative predictive value [NPV]: 0.81). In addition, lower AßX-42/X-40 ratios were associated with negative PACC5 slopes, suggesting cognitive decline. DISCUSSION: Our results suggest that assessing the plasma AßX-42/X-40 ratio via our semiautomated IP-IA is a promising biomarker when examining patients with early or preclinical AD. HIGHLIGHTS: New plasma Aß42/Aß40 measurement using immunoprecipitation-immunoassay Plasma Aß42/Aß40 associated with longitudinal cognitive decline Promising biomarker to detect subjective cognitive decline at-risk for brain amyloid positivity.

2.
Artículo en Inglés | MEDLINE | ID: mdl-38316685

RESUMEN

The Aß42/40 ratio and the concentration of phosphorylated Tau181 in blood plasma represent attractive biomarkers for Alzheimer's disease. As a means for reducing potential matrix effects, which may interfere with plasma immunoassays, we have previously developed a pre-analytical sample workup by semi-automated immunoprecipitation. Here we test the compatibility of pre-analytical immunoprecipitations with automated Aß1-40, Aß1-42 and phosphorylated Tau181 immunoassays on the Lumipulse platform and compare the diagnostic performance of the respective immunoprecipitation immunoassay approaches with direct plasma measurements. 71 participants were dichotomized according to their Aß42/40 ratios in cerebrospinal fluid into the diagnostic groups amyloid-positive (n = 32) and amyloid-negative (n = 39). The plasma Aß1-42/1-40 ratio and phosphorylated Tau181 levels were determined on the Lumipulse G600II platform (Fujirebio) by direct measurements in EDTA-plasma or after Aß- or Tau-immunoprecipitation, respectively. Pre-analytical immunoprecipitation of Aß turned out to be compatible with the Lumipulse Aß assays and resulted in a numerical, yet statistically not significant increase in the area under the ROC curve for plasma Aß1-42/1-40. Additionally, we observed a significant increase in the standardised effect size (Cohen's D). Pre-analytical immunoprecipitation of Tau resulted in increased differences between the diagnostic groups in terms of median and mean phosphorylated Tau 181 levels. Furthermore, we observed a greater Cohen's d (p < 0.001) and a larger area under the ROC curve (p = 0.038) after Tau-IP. Our preliminary findings in a small, preselected sample indicate that pre-analytical immunoprecipitation may have the potential to improve the diagnostic performance of plasma biomarker immunoassays for Aß1-42/1-40 and phosphorylated Tau181 to predict brain amyloid deposition.

3.
Clin Kidney J ; 16(12): 2461-2471, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38046015

RESUMEN

Background: Acute kidney injury (AKI) is a common complication after major surgery. This study assessed the risk of developing or worsening of chronic kidney disease (CKD) and other clinical outcomes in patients experiencing AKI after major surgery. Methods: This retrospective observational study used Optum's de-identified Clinformatics Data Mart Database to investigate cardiorenal outcomes in adult patients at the first AKI event following major surgery. The primary outcome was CKD stage ≥3; secondary outcomes included myocardial infarction (MI), stroke, heart failure, all-cause hospitalization, end-stage kidney disease, need for dialysis or kidney transplant and composite measures. Follow-up was up to 3 years. Additionally, the effect of intercurrent events on the risk of clinical outcomes was assessed. Results: Of the included patients (N = 31 252), most were male (61.9%) and White (68.9%), with a median age of 72 years (interquartile range 64-79). The event rates were 25.5 events/100 patient-years (PY) for CKD stage ≥3, 3.1 events/100 PY for end-stage kidney disease, 3.0 events/100 PY for dialysis and 0.1 events/100 PY for kidney transplants. Additionally, there were 6.9 events/100 PY for MI, 8.7 events/100 PY for stroke and 49.8 events/100 PY for all-cause hospitalization during follow-up. Patients with AKI relapses as intercurrent events were more likely to develop CKD stage ≥3 than those with just one AKI event after major surgery. Conclusion: This analysis demonstrated that patients experiencing AKI following major surgery are at high risk of developing severe CKD or worsening of pre-existing CKD and other cardiorenal clinical outcomes such as MI and stroke.

4.
J Nephrol ; 36(1): 45-54, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-35567698

RESUMEN

BACKGROUND: The observational, real-world evidence FLIEDER study aimed to describe patient clinical characteristics and investigate clinical outcomes in non-diabetic patients with chronic kidney disease (CKD) using data collected from routine clinical practice in the United States. METHODS: Between 1 January, 2008-31 December, 2018, individuals aged ≥ 18 years, with non-diabetic, stage 3-4 CKD were indexed in the Optum® Clinformatics® Data Mart US healthcare claims database using International Classification of Diseases-9/10 codes for CKD or by laboratory values (estimated glomerular filtration rate [eGFR] 15-59 mL/min/1.73 m2). The primary outcomes were hospitalization for heart failure, a composite kidney outcome of end-stage kidney disease/kidney failure/need for dialysis and worsening of CKD stage from baseline. The effects of the intercurrent events of a sustained post-baseline decline in eGFR ≥ 30%, ≥ 40%, and ≥ 57% on the subsequent risk of the primary outcomes were also assessed. RESULTS: In the main study cohort (N = 504,924), median age was 75.0 years, and 60.5% were female. Most patients (94.7%) had stage 3 CKD at index. Incidence rates for hospitalization for heart failure, the composite kidney outcome, and worsening of CKD stage from baseline were 4.0, 10.3, and 4.4 events/100 patient-years, respectively. The intercurrent event analysis demonstrated that a relative decline in kidney function from baseline significantly increased the risk of cardiorenal events. CONCLUSIONS: This real-world study highlights that patients with non-diabetic CKD are at high risk of serious adverse clinical outcomes, and that this risk is amplified in patients who experienced greater post-baseline eGFR decline.


Asunto(s)
Insuficiencia Cardíaca , Fallo Renal Crónico , Insuficiencia Renal Crónica , Anciano , Femenino , Humanos , Masculino , Atención a la Salud , Progresión de la Enfermedad , Tasa de Filtración Glomerular , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/epidemiología , Insuficiencia Cardíaca/terapia , Fallo Renal Crónico/diagnóstico , Fallo Renal Crónico/epidemiología , Fallo Renal Crónico/terapia , Insuficiencia Renal Crónica/diagnóstico , Insuficiencia Renal Crónica/epidemiología , Insuficiencia Renal Crónica/terapia , Estudios Retrospectivos , Estados Unidos/epidemiología
5.
Fluids Barriers CNS ; 19(1): 96, 2022 Dec 03.
Artículo en Inglés | MEDLINE | ID: mdl-36461122

RESUMEN

BACKGROUND: A reduced amyloid-ß (Aß)42/40 peptide ratio in blood plasma represents a peripheral biomarker of the cerebral amyloid pathology observed in Alzheimer's disease brains. The magnitude of the measurable effect in plasma is smaller than in cerebrospinal fluid, presumably due to dilution by Aß peptides originating from peripheral sources. We hypothesized that the observable effect in plasma can be accentuated to some extent by specifically measuring Aß1-42 and Aß1-40 instead of AßX-42 and AßX-40. METHODS: We assessed the plasma AßX-42/X-40 and Aß1-42/1-40 ratios in an idealized clinical sample by semi-automated Aß immunoprecipitation followed by closely related sandwich immunoassays. The amyloid-positive and amyloid-negative groups (dichotomized according to Aß42/40 in cerebrospinal fluid) were compared regarding the median difference, mean difference, standardized effect size (Cohen's d) and receiver operating characteristic curves. For statistical evaluation, we applied bootstrapping. RESULTS: The median Aß1-42/1-40 ratio was 20.86% lower in amyloid-positive subjects than in the amyloid-negative group, while the median AßX-42/X-40 ratio was only 15.56% lower. The relative mean difference between amyloid-positive and amyloid-negative subjects was -18.34% for plasma Aß1-42/1-40 compared to -15.50% for AßX-42/X-40. Cohen's d was 1.73 for Aß1-42/1-40 and 1.48 for plasma AßX-42/X-40. Unadjusted p-values < 0.05 were obtained after .632 bootstrapping for all three parameters. Receiver operating characteristic analysis indicated very similar areas under the curves for plasma Aß1-42/1-40 and AßX-42/X-40. CONCLUSIONS: Our findings support the hypothesis that the relatively small difference in the plasma Aß42/40 ratio between subjects with and without evidence of brain amyloidosis can be accentuated by specifically measuring Aß1-42/1-40 instead of AßX-42/X-40. A simplified theoretical model explaining this observation is presented.


Asunto(s)
Enfermedad de Alzheimer , Humanos , Plasma , Biomarcadores , Curva ROC , Encéfalo
6.
Alzheimers Res Ther ; 14(1): 127, 2022 09 07.
Artículo en Inglés | MEDLINE | ID: mdl-36071505

RESUMEN

BACKGROUND: Measurements of the amyloid-ß (Aß) 42/40 ratio in blood plasma may support the early diagnosis of Alzheimer's disease and aid in the selection of suitable participants in clinical trials. Here, we compared the diagnostic performance of fully automated prototype plasma Aß42/40 assays with and without pre-analytical sample workup by immunoprecipitation. METHODS: A pre-selected clinical sample comprising 42 subjects with normal and 38 subjects with low cerebrospinal fluid (CSF) Aß42/40 ratios was studied. The plasma Aß42/40 ratios were determined with fully automated prototype Elecsys® immunoassays (Roche Diagnostics GmbH, Penzberg, Germany) by direct measurements in EDTA plasma or after pre-analytical Aß immunoprecipitation. The diagnostic performance for the detection of abnormal CSF Aß42/40 was analyzed by receiver operating characteristic (ROC) analysis. In an additional post hoc analysis, a biomarker-supported clinical diagnosis was used as a second endpoint. RESULTS: Pre-analytical immunoprecipitation resulted in a significant increase in the area under the ROC curve (AUC) from 0.73 to 0.88 (p = 0.01547) for identifying subjects with abnormal CSF Aß42/40. A similar improvement in the diagnostic performance by pre-analytical immunoprecipitation was also observed when a biomarker-supported clinical diagnosis was used as a second endpoint (AUC increase from 0.77 to 0.92, p = 0.01576). CONCLUSIONS: Our preliminary observations indicate that pre-analytical Aß immunoprecipitation can improve the diagnostic performance of plasma Aß assays for detecting brain amyloid pathology. The findings may aid in the further development of blood-based immunoassays for Alzheimer's disease ultimately suitable for screening and routine use.


Asunto(s)
Enfermedad de Alzheimer , Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides/líquido cefalorraquídeo , Biomarcadores/líquido cefalorraquídeo , Humanos , Inmunoprecipitación , Fragmentos de Péptidos/líquido cefalorraquídeo , Plasma
7.
J Neural Transm (Vienna) ; 129(5-6): 477-486, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35061102

RESUMEN

ApoE4, the strongest genetic risk factor for Alzheimer's disease (AD), has been shown to be associated with both beta-amyloid (Aß) and tau pathology, with the strongest evidence for effects on Aß, while the association between ApoE4 and tau pathology remains inconsistent. This study aimed to investigate the associations between ApoE4 with CSF Aß42, total tau (t-tau), phospho-tau181 (p-tau), and with the progression of decline in a large cohort of MCI subjects, both progressors to AD and other dementias, as well as non-progressors. We analyzed associations of CSF Aß42, p-tau and t-tau with ApoE4 allele frequency cross-sectionally and longitudinally over 3 years of follow-up in 195 individuals with a diagnosis of MCI-stable, MCI-AD converters and MCI progressing to other dementias from the German Dementia Competence Network. In the total sample, ApoE4 carriers had lower concentrations of CSF Aß42, and increased concentrations of t-tau and p-tau compared to non-carriers in a gene dose-dependent manner. Comparisons of these associations stratified by MCI-progression groups showed a significant influence of ApoE4 carriership and diagnostic group on all CSF biomarker levels. The effect of ApoE4 was present in MCI-stable individuals but not in the other groups, with ApoE4 + carriers having decreased CSF Aß 42 levels, and increased concentration of t-tau and p-tau. Longitudinally, individuals with abnormal t-tau and Aß42 had a more rapid progression of cognitive and clinical decline, independently of ApoE4 genotype. Overall, our results contribute to an emerging framework in which ApoE4 involves mechanisms associated with both CSF amyloid-ß burden and tau aggregation at specific time points in AD pathogenesis.


Asunto(s)
Enfermedad de Alzheimer , Disfunción Cognitiva , Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides/líquido cefalorraquídeo , Apolipoproteína E4/genética , Biomarcadores/líquido cefalorraquídeo , Disfunción Cognitiva/diagnóstico , Genotipo , Humanos , Fragmentos de Péptidos/líquido cefalorraquídeo , Proteínas tau/líquido cefalorraquídeo
8.
J Transl Med ; 19(1): 274, 2021 06 26.
Artículo en Inglés | MEDLINE | ID: mdl-34174885

RESUMEN

BACKGROUND: There is a huge body of scientific literature describing the relation between tumor types and anti-cancer drugs. The vast amount of scientific literature makes it impossible for researchers and physicians to extract all relevant information manually. METHODS: In order to cope with the large amount of literature we applied an automated text mining approach to assess the relations between 30 most frequent cancer types and 270 anti-cancer drugs. We applied two different approaches, a classical text mining based on named entity recognition and an AI-based approach employing word embeddings. The consistency of literature mining results was validated with 3 independent methods: first, using data from FDA approvals, second, using experimentally measured IC-50 cell line data and third, using clinical patient survival data. RESULTS: We demonstrated that the automated text mining was able to successfully assess the relation between cancer types and anti-cancer drugs. All validation methods showed a good correspondence between the results from literature mining and independent confirmatory approaches. The relation between most frequent cancer types and drugs employed for their treatment were visualized in a large heatmap. All results are accessible in an interactive web-based knowledge base using the following link: https://knowledgebase.microdiscovery.de/heatmap . CONCLUSIONS: Our approach is able to assess the relations between compounds and cancer types in an automated manner. Both, cancer types and compounds could be grouped into different clusters. Researchers can use the interactive knowledge base to inspect the presented results and follow their own research questions, for example the identification of novel indication areas for known drugs.


Asunto(s)
Antineoplásicos , Neoplasias , Minería de Datos , Humanos , Bases del Conocimiento , Neoplasias/tratamiento farmacológico , Publicaciones
9.
Commun Biol ; 3(1): 573, 2020 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-33060801

RESUMEN

Uncovering cellular responses from heterogeneous genomic data is crucial for molecular medicine in particular for drug safety. This can be realized by integrating the molecular activities in networks of interacting proteins. As proof-of-concept we challenge network modeling with time-resolved proteome, transcriptome and methylome measurements in iPSC-derived human 3D cardiac microtissues to elucidate adverse mechanisms of anthracycline cardiotoxicity measured with four different drugs (doxorubicin, epirubicin, idarubicin and daunorubicin). Dynamic molecular analysis at in vivo drug exposure levels reveal a network of 175 disease-associated proteins and identify common modules of anthracycline cardiotoxicity in vitro, related to mitochondrial and sarcomere function as well as remodeling of extracellular matrix. These in vitro-identified modules are transferable and are evaluated with biopsies of cardiomyopathy patients. This to our knowledge most comprehensive study on anthracycline cardiotoxicity demonstrates a reproducible workflow for molecular medicine and serves as a template for detecting adverse drug responses from complex omics data.


Asunto(s)
Metaboloma , Modelos Biológicos , Proteoma , Transcriptoma , Epigénesis Genética , Perfilación de la Expresión Génica/métodos , Regulación de la Expresión Génica , Redes Reguladoras de Genes , Humanos , Metabolómica/métodos , Mitocondrias/genética , Mitocondrias/metabolismo , Proteómica/métodos , Sarcómeros/genética , Sarcómeros/metabolismo , Transducción de Señal
10.
J Alzheimers Dis ; 76(3): 1005-1015, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32597807

RESUMEN

BACKGROUND: Cognitive functions and activities of daily living (ADL) become increasingly impaired with progressing Alzheimer's disease. However, the temporal dynamics of this decline are inconsistent. OBJECTIVE: To gain insight into the classical temporal cascade of specific cognitive and ADL changes, which may aid in improving detection of an impending clinical deterioration in patients, and to select ADL items and tests most sensitive to change in a specific disease stage. METHODS: Patients with mild Alzheimer's dementia (AD; MMSE = 23.9±2.88) were followed at 12 and 24 months. Lead-lag analysis of changes in cognitive and functional outcome measures (CDR-SOB, 12 neuropsychological subtest scores from the CERAD + test battery, 25 Bayer-ADL items) was applied to rank the temporal sequence of changes on an ordinal scale. RESULTS: Of 164 patients with mild AD, moderate disease progression was identified in 84 patients over 24 months (ΔMMSE 5.8±8.64; ΔCDR-SOB 4.32±4.03). Ten Bayer-ADL item measures were altered early in moderate progressors and included in a new ADL composite score. Accordingly, the new ADL score surpassed all neuropsychological measures in repeated lead-lag analysis. The Bayer-ADL total score, TMT-A, and MMSE were lagging variables in all lead-lag analyses. CONCLUSION: Short-term clinical deterioration in mild AD is initially preceded by changes (i.e., decline) in a well-defined set of ADL and not in classical cognitive measures.


Asunto(s)
Actividades Cotidianas/psicología , Enfermedad de Alzheimer/psicología , Deterioro Clínico , Cognición/fisiología , Anciano , Progresión de la Enfermedad , Femenino , Humanos , Masculino , Pruebas Neuropsicológicas , Factores de Tiempo
11.
Cell Syst ; 9(6): 569-579.e7, 2019 12 18.
Artículo en Inglés | MEDLINE | ID: mdl-31521604

RESUMEN

Estimating fold changes of average mRNA and protein molecule counts per cell is the most common way to perform differential expression analysis. However, these gene expression data may be affected by cell division, an often-neglected phenomenon. Here, we develop a quantitative framework that links population-based mRNA and protein measurements to rates of gene expression in single cells undergoing cell division. The equations we derive are easy-to-use and widely robust against biological variability. They integrate multiple "omics" data into a coherent, quantitative description of single-cell gene expression and improve analysis when comparing systems or states with different cell division times. We explore these ideas in the context of resting versus activated B cells. Analyzing differences in protein synthesis rates enables to account for differences in cell division times. We demonstrate that this improves the resolution and hit rate of differential gene expression analysis when compared to analyzing population protein abundances alone.


Asunto(s)
Biología Computacional/métodos , Perfilación de la Expresión Génica/métodos , Linfocitos B/metabolismo , Linfocitos B/fisiología , División Celular/genética , División Celular/fisiología , Análisis de Datos , Expresión Génica/genética , Expresión Génica/fisiología , Humanos , Modelos Teóricos , Proteínas/metabolismo , ARN Mensajero/metabolismo
12.
J Neural Transm (Vienna) ; 126(3): 339-348, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30767082

RESUMEN

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by the presence of extracellular amyloid plaques (senile plaques) and intracellular neurofibrillary tangles formed by hyperphosphorylated tau protein. This process leads to neuronal degradation and neuronal death. Phosphorylation of tau protein at threonine 231 (p-tau231) has been shown to be characteristic in post-mortem brain tissue of patients with AD and it can be sensitively detected in cerebrospinal fluid (CSF). Therefore, it may serve as a biomarker to support the diagnosis of AD. In this study, we analysed how well p-tau231 could differentiate between patients suffering from dementia either due or not due to AD by a sandwich enzyme immunoassay. CSF p-tau231 was significantly higher in patients with dementia due to AD than in those with dementia due to other causes. In addition, we studied different factors affecting p-tau231 levels in CSF. We found that apolipoprotein E genotype influences p-tau231 CSF levels. Gender and age did not affect p-tau231 levels in CSF. Our findings indicate that p-tau231 levels in CSF can be a valuable marker for the clinical diagnosis of AD.


Asunto(s)
Enfermedad de Alzheimer/líquido cefalorraquídeo , Enfermedad de Alzheimer/diagnóstico , Biomarcadores/líquido cefalorraquídeo , Proteínas tau/líquido cefalorraquídeo , Anciano , Ensayo de Inmunoadsorción Enzimática/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Fosforilación
13.
Alzheimers Res Ther ; 10(1): 121, 2018 12 08.
Artículo en Inglés | MEDLINE | ID: mdl-30526652

RESUMEN

BACKGROUND: The quantification of amyloid-beta (Aß) peptides in blood plasma as potential biomarkers of Alzheimer's disease (AD) is hampered by very low Aß concentrations and the presence of matrix components that may interfere with the measurements. METHODS: We developed a two-step immunoassay for the simultaneous measurement of the relative levels of Aß38, Aß40 and Aß42 in human EDTA plasma. The assay was employed for the study of 23 patients with dementia of the Alzheimer's type (AD-D) and 17 patients with dementia due to other reasons (OD). We examined relationships with the clinical diagnosis, cerebral Aß load as quantified by amyloid-positron emission tomography, apolipoprotein E genotype, Aß levels and Tau protein in cerebrospinal fluid. RESULTS: Preconcentration of plasma Aß peptides by immunoprecipitation substantially facilitated their immunological measurements. The Aß42/Aß40 and Aß42/Aß38 ratios were statistically significantly lower in the AD-D patients than in the OD group. The areas under the receiver operating characteristic curves reached 0.87 for the Aß42/Aß40 ratio and 0.80 for the Aß42/Aß38 ratio. CONCLUSIONS: The measurement of plasma Aß peptides with an immunological assay can be improved by preconcentration via immunoprecipitation with an antibody against the Aß amino-terminus and elution of the captured peptides by heating in a mild detergent-containing buffer. Our findings support the Aß42/Aß40 ratio in blood plasma as a promising AD biomarker candidate which correlates significantly with the validated core biomarkers of AD. Further studies will be needed for technical advancement of the assay and validation of the biomarker findings.


Asunto(s)
Enfermedad de Alzheimer/sangre , Enfermedad de Alzheimer/diagnóstico , Péptidos beta-Amiloides/sangre , Inmunoensayo/métodos , Fragmentos de Péptidos/sangre , Anciano , Enfermedad de Alzheimer/líquido cefalorraquídeo , Péptidos beta-Amiloides/líquido cefalorraquídeo , Apolipoproteínas E/genética , Biomarcadores/sangre , Biomarcadores/líquido cefalorraquídeo , Femenino , Humanos , Inmunoprecipitación/métodos , Masculino , Persona de Mediana Edad , Fragmentos de Péptidos/líquido cefalorraquídeo , Curva ROC , Reproducibilidad de los Resultados
15.
Alzheimers Res Ther ; 9(1): 84, 2017 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-29017593

RESUMEN

BACKGROUND: The progression of mild cognitive impairment (MCI) to Alzheimer's disease (AD) dementia can be predicted by cognitive, neuroimaging, and cerebrospinal fluid (CSF) markers. Since most biomarkers reveal complementary information, a combination of biomarkers may increase the predictive power. We investigated which combination of the Mini-Mental State Examination (MMSE), Clinical Dementia Rating (CDR)-sum-of-boxes, the word list delayed free recall from the Consortium to Establish a Registry of Dementia (CERAD) test battery, hippocampal volume (HCV), amyloid-beta1-42 (Aß42), amyloid-beta1-40 (Aß40) levels, the ratio of Aß42/Aß40, phosphorylated tau, and total tau (t-Tau) levels in the CSF best predicted a short-term conversion from MCI to AD dementia. METHODS: We used 115 complete datasets from MCI patients of the "Dementia Competence Network", a German multicenter cohort study with annual follow-up up to 3 years. MCI was broadly defined to include amnestic and nonamnestic syndromes. Variables known to predict progression in MCI patients were selected a priori. Nine individual predictors were compared by receiver operating characteristic (ROC) curve analysis. ROC curves of the five best two-, three-, and four-parameter combinations were analyzed for significant superiority by a bootstrapping wrapper around a support vector machine with linear kernel. The incremental value of combinations was tested for statistical significance by comparing the specificities of the different classifiers at a given sensitivity of 85%. RESULTS: Out of 115 subjects, 28 (24.3%) with MCI progressed to AD dementia within a mean follow-up period of 25.5 months. At baseline, MCI-AD patients were no different from stable MCI in age and gender distribution, but had lower educational attainment. All single biomarkers were significantly different between the two groups at baseline. ROC curves of the individual predictors gave areas under the curve (AUC) between 0.66 and 0.77, and all single predictors were statistically superior to Aß40. The AUC of the two-parameter combinations ranged from 0.77 to 0.81. The three-parameter combinations ranged from AUC 0.80-0.83, and the four-parameter combination from AUC 0.81-0.82. None of the predictor combinations was significantly superior to the two best single predictors (HCV and t-Tau). When maximizing the AUC differences by fixing sensitivity at 85%, the two- to four-parameter combinations were superior to HCV alone. CONCLUSION: A combination of two biomarkers of neurodegeneration (e.g., HCV and t-Tau) is not superior over the single parameters in identifying patients with MCI who are most likely to progress to AD dementia, although there is a gradual increase in the statistical measures across increasing biomarker combinations. This may have implications for clinical diagnosis and for selecting subjects for participation in clinical trials.


Asunto(s)
Enfermedad de Alzheimer/diagnóstico , Disfunción Cognitiva/diagnóstico , Anciano , Enfermedad de Alzheimer/patología , Enfermedad de Alzheimer/fisiopatología , Péptidos beta-Amiloides/líquido cefalorraquídeo , Biomarcadores/líquido cefalorraquídeo , Disfunción Cognitiva/patología , Disfunción Cognitiva/fisiopatología , Progresión de la Enfermedad , Escolaridad , Femenino , Estudios de Seguimiento , Hipocampo/diagnóstico por imagen , Hipocampo/patología , Humanos , Masculino , Pruebas Neuropsicológicas , Tamaño de los Órganos , Fragmentos de Péptidos/líquido cefalorraquídeo , Fosforilación , Pronóstico , Sensibilidad y Especificidad , Máquina de Vectores de Soporte , Proteínas tau/líquido cefalorraquídeo
16.
J Biol Chem ; 291(46): 24172-24187, 2016 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-27637333

RESUMEN

Transcription factors of the nuclear factor of activated T cell (NFAT) family are essential for antigen-specific T cell activation and differentiation. Their cooperative DNA binding with other transcription factors, such as AP1 proteins (FOS, JUN, and JUNB), FOXP3, IRFs, and EGR1, dictates the gene regulatory action of NFATs. To identify as yet unknown interaction partners of NFAT, we purified biotin-tagged NFATc1/αA, NFATc1/ßC, and NFATc2/C protein complexes and analyzed their components by stable isotope labeling by amino acids in cell culture-based mass spectrometry. We revealed more than 170 NFAT-associated proteins, half of which are involved in transcriptional regulation. Among them are many hitherto unknown interaction partners of NFATc1 and NFATc2 in T cells, such as Raptor, CHEK1, CREB1, RUNX1, SATB1, Ikaros, and Helios. The association of NFATc2 with several other transcription factors is DNA-dependent, indicating cooperative DNA binding. Moreover, our computational analysis discovered that binding motifs for RUNX and CREB1 are found preferentially in the direct vicinity of NFAT-binding motifs and in a distinct orientation to them. Furthermore, we provide evidence that mTOR and CHEK1 kinase activity influence NFAT's transcriptional potency. Finally, our dataset of NFAT-associated proteins provides a good basis to further study NFAT's diverse functions and how these are modulated due to the interplay of multiple interaction partners.


Asunto(s)
Factores de Transcripción NFATC/metabolismo , Proteínas Nucleares/metabolismo , Linfocitos T/metabolismo , Humanos , Células Jurkat , Espectrometría de Masas , Factores de Transcripción NFATC/genética , Proteínas Nucleares/genética
17.
J Alzheimers Dis ; 54(2): 691-705, 2016 09 06.
Artículo en Inglés | MEDLINE | ID: mdl-27567847

RESUMEN

A comprehensive assay validation campaign of a commercially available chemiluminescence multiplex immunoassay for the simultaneous measurement of the amyloid-ß peptides Aß38, Aß40, and Aß42 in human cerebrospinal fluid (CSF) is presented. The assay quality parameters we addressed included impact of sample dilution, parallelism, lower limits of detection, lower limits of quantification, intra- and inter-assay repeatability, analytical spike recoveries, and between laboratory reproducibility of the measurements. The assay performed well in our hands and fulfilled a number of predefined acceptance criteria. The CSF levels of Aß40 and Aß42 determined in a clinical cohort (n = 203) were statistically significantly correlated with available ELISA data of Aß1-40 (n = 158) and Aß1-42 (n = 179) from a different laboratory. However, Bland-Altman method comparison indicated systematic differences between the assays. The data presented here furthermore indicate that the CSF concentration of Aß40 can surrogate total CSF Aß and support the hypothesis that the Aß42/Aß40 ratio outperforms CSF Aß42 alone as a biomarker for Alzheimer's disease due to a normalization to total Aß levels.


Asunto(s)
Enfermedad de Alzheimer/líquido cefalorraquídeo , Péptidos beta-Amiloides/líquido cefalorraquídeo , Luminiscencia , Fragmentos de Péptidos/líquido cefalorraquídeo , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/diagnóstico , Biomarcadores/líquido cefalorraquídeo , Estudios de Cohortes , Ensayo de Inmunoadsorción Enzimática/normas , Femenino , Humanos , Masculino , Persona de Mediana Edad
18.
Eur J Immunol ; 45(11): 3150-7, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26300430

RESUMEN

Transcription factors (TFs) regulate cell-type-specific gene expression programs by combinatorial binding to cis-genomic elements, particularly enhancers, subsequently leading to the recruitment of cofactors, and the general transcriptional machinery to target genes. Using data integration of genome-wide TF binding profiles, we defined regions with combinatorial binding of lineage-specific master TFs (T-BET, GATA3, and ROR-γt) and STATs (STAT1 and STAT4, STAT6, and STAT3) in murine T helper (Th) 1, Th2, and Th17 cells, respectively. Stringently excluding promoter regions, we revealed precise genomic elements which were preferentially associated with the enhancer marks p300 and H3K4me1. Furthermore, closely adjacent TF co-occupied regions constituted larger enhancer domains in the respective Th-cell subset (177 in Th1, 141 in Th2, and 266 in Th17 cells) with characteristics of so-called super-enhancers. Importantly, 89% of these super-enhancer regions were Th-cell subtype-specific. Genes associated with super-enhancers, including relevant Th-cell genes (such as Ifng in Th1, Il13 in Th2, and Il17a in Th17 cells), showed strong transcriptional activity. Altogether, the discovered catalog of enhancers provides information about crucial Th-cell subtype-specific regulatory hubs, which will be useful for revealing cell-type-specific gene regulation processes.


Asunto(s)
Regulación de la Expresión Génica/genética , Regulación de la Expresión Génica/inmunología , Subgrupos de Linfocitos T/inmunología , Linfocitos T Colaboradores-Inductores/inmunología , Animales , Secuencia de Bases , Inmunoprecipitación de Cromatina , Ratones , Datos de Secuencia Molecular , Factores de Transcripción/inmunología
19.
Cancer Inform ; 14: 55-63, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26005322

RESUMEN

Personalized medicine is promising a revolution for medicine and human biology in the 21st century. The scientific foundation for this revolution is accomplished by analyzing biological high-throughput data sets from genomics, transcriptomics, proteomics, and metabolomics. Currently, access to these data has been limited to either rather simple Web-based tools, which do not grant much insight or analysis by trained specialists, without firsthand involvement of the physician. Here, we present the novel Web-based tool "BioMiner," which was developed within the scope of an international and interdisciplinary project (SYSTHER) and gives access to a variety of high-throughput data sets. It provides the user with convenient tools to analyze complex cross-omics data sets and grants enhanced visualization abilities. BioMiner incorporates transcriptomic and cross-omics high-throughput data sets, with a focus on cancer. A public instance of BioMiner along with the database is available at http://systherDB.microdiscovery.de/, login and password: "systher"; a tutorial detailing the usage of BioMiner can be found in the Supplementary File.

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