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Amyloid-ß (Aß) is thought to be neuronally derived in Alzheimer's disease (AD). However, transcripts of amyloid precursor protein (APP) and amyloidogenic enzymes are equally abundant in oligodendrocytes (OLs). By cell-type-specific deletion of Bace1 in a humanized knock-in AD model, APPNLGF, we demonstrate that OLs and neurons contribute to Aß plaque burden. For rapid plaque seeding, excitatory projection neurons must provide a threshold level of Aß. Ultimately, our findings are relevant for AD prevention and therapeutic strategies.
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AIMS: The aggregation and deposition of amyloid-ß (Aß) peptides in the brain is thought to be the initial driver in the pathogenesis of Alzheimer's disease (AD). Aside from full-length Aß peptides starting with an aspartate residue in position 1, both N-terminally truncated and elongated Aß peptides are produced by various proteases from the amyloid precursor protein (APP) and have been detected in brain tissues and body fluids. Recently, we demonstrated that the particularly abundant N-terminally truncated Aß4-x peptides are generated by ADAMTS4, a secreted metalloprotease that is exclusively expressed in the oligodendrocyte cell population. In this study, we investigated whether ADAMTS4 might also be involved in the generation of N-terminally elongated Aß peptides. METHODS: We used cell-free and cell-based assays in combination with matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF) and electrochemiluminescence sandwich immunoassays to identify and quantify N-terminally elongated Aß peptide variants. Antibodies against these Aß variants were characterised by peptide microarrays and employed for the immunohistochemical analyses of human brain samples. RESULTS: In this study, we discovered additional ADAMTS4 cleavage sites in APP. These were located N-terminal to Asp-(1) in the Aß peptide sequence between residues Glu-(-7) and Ile-(-6) as well as Glu-(-4) and Val-(-3), resulting in the release of N-terminally elongated Aß-6-x and Aß-3-x peptides, of which the latter serve as a component in a promising Aß-based plasma biomarker. Aß-6/-3-40 peptides were detected in supernatants of various cell lines and in the cerebrospinal fluid (CSF), and ADAMTS4 enzyme activity promoted the release of Aß-6/-3-x peptides. Furthermore, by immunohistochemistry, a subset of AD cases displayed evidence of extracellular and vascular localization of N-terminally elongated Aß-6/-3-x peptides. DISCUSSION: The current findings implicate ADAMTS4 in both the pathological process of Aß peptide aggregation and in the early detection of amyloid pathology in AD.
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Proteína ADAMTS4 , Enfermedad de Alzheimer , Péptidos beta-Amiloides , Encéfalo , Humanos , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/patología , Proteína ADAMTS4/metabolismo , Péptidos beta-Amiloides/metabolismo , Encéfalo/metabolismo , Encéfalo/patología , Anciano , Masculino , Femenino , Anciano de 80 o más AñosRESUMEN
BACKGROUND: Many piercing-sucking insects have developed resistance or cross-resistance to many insecticides targeting insect neural nicotinic acetylcholine receptor (nAChR). Here we are aiming to present the discovery of a novel mesoionic insecticide, fenmezoditiaz, by BASF through structure-based drug design (SBDD) approaches. It has recently been added to the Insecticide Resistance Action Committee mode of classification (IRAC 4E). It is being developed for plant protection against piercing-sucking pests, especially rice hopper complex. RESULTS: The soluble acetylcholine binding protein (AChBP) from the sea slug Aplysia californica was modified using site-directed mutagenesis and based on putative aphid nAChR subunit sequences to create soluble insect-like AChBPs. Among them, insect-like ß1 AChBP and native aphid membrane preparation showed the highest correlated biochemical affinity toward structurally diverse ligands. This mutant AChBP was used to understand how insect nAChRs structurally interact with mesoionics, which was then utilized to design novel mesoionics including fenmezoditiaz. It is an excellent systemic insecticide with diverse application methods and has a broad insecticidal spectrum, especially against piercing/sucking insects. It lacks cross-resistance for neonicotinoid resistant plant hoppers. Field-collected brown plant hopper populations from Asian countries showed high susceptibility. CONCLUSIONS: Fenmezoditiaz is a systemic insecticide with a broad spectrum, lack of cross-resistance and it could be an additional tool for integrated pest management and insecticide resistance management, especially for the rice hopper complex. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
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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.
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INTRODUCTION: The role of visceral fat in disease development, particularly in Crohn´s disease (CD), is significant. However, its preoperative prognostic value for postoperative complications and CD relapse after ileocecal resection (ICR) remains unknown. This study aims to assess the predictive potential of preoperatively measured visceral and subcutaneous fat in postoperative complications and CD recurrence using magnetic resonance imaging (MRI). The primary endpoint was postoperative anastomotic leakage of the ileocolonic anastomosis, with secondary endpoints evaluating postoperative complications according to the Clavien Dindo classification and CD recurrence at the anastomosis. METHODS: We conducted a retrospective analysis of 347 CD patients who underwent ICR at our tertiary referral center between 2010 and 2020. We included 223 patients with high-quality preoperative MRI scans, recording demographics, postoperative outcomes, and CD recurrence rates at the anastomosis. To assess adipose tissue distribution, we measured total fat area (TFA), visceral fat area (VFA), subcutaneous fat area (SFA), and abdominal circumference (AC) at the lumbar 3 (L3) level using MRI cross-sectional images. Ratios of these values were calculated. RESULTS: None of the radiological variables showed an association with anastomotic leakage (TFA p = 0.932, VFA p = 0.982, SFA p = 0.951, SFA/TFA p = 0.422, VFA/TFA p = 0.422), postoperative complications, or CD recurrence (TFA p = 0.264, VFA p = 0.916, SFA p = 0.103, SFA/TFA p = 0.059, VFA/TFA p = 0.059). CONCLUSIONS: Radiological visceral obesity variables were associated with postoperative outcomes or clinical recurrence in CD patients undergoing ICR. Preoperative measurement of visceral fat measurement is not specific for predicting postoperative complications or CD relapse.
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Enfermedad de Crohn , Humanos , Enfermedad de Crohn/complicaciones , Enfermedad de Crohn/diagnóstico por imagen , Enfermedad de Crohn/cirugía , Estudios Retrospectivos , Grasa Intraabdominal/diagnóstico por imagen , Grasa Intraabdominal/patología , Fuga Anastomótica/patología , Recurrencia , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/patologíaRESUMEN
Senile plaques consisting of amyloid-beta (Aß) peptides are a major pathological hallmark of Alzheimer's disease (AD). Aß peptides are heterogeneous regarding the exact length of their amino- and carboxy-termini. Aß1-40 and Aß1-42 are often considered to represent canonical "full-length" Aß species. Using immunohistochemistry, we analyzed the distribution of Aß1-x, Aßx-42 and Aß4-x species in amyloid deposits in the subiculum, hippocampus and cortex in 5XFAD mice during aging. Overall plaque load increased in all three brain regions, with the subiculum being the area with the strongest relative plaque coverage. In the subiculum, but not in the other brain regions, the Aß1-x load peaked at an age of five months and decreased thereafter. In contrast, the density of plaques positive for N-terminally truncated Aß4-x species increased continuously over time. We hypothesize that ongoing plaque remodeling takes place, leading to a conversion of deposited Aß1-x peptides into Aß4-x peptides in brain regions with a high Aß plaque burden.
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A variety of factors has been associated with healthy brain aging, and epidemiological studies suggest that physical activity and nutritional supplements such as caffeine may reduce the risk of developing dementia and, in particular, Alzheimer's disease (AD) in later life. Caffeine is known to act as a cognitive enhancer but has been also shown to positively affect exercise performance in endurance activities. We have previously observed that chronic oral caffeine supplementation and a treatment paradigm encompassing physical and cognitive stimulation by enriched environment (EE) housing can improve learning and memory performance and ameliorate hippocampal neuron loss in the Tg4-42 mouse model of AD. Here, we investigated whether these effects were synergistic. To that end, previous findings on individual treatments were complemented with unpublished, additional data and analyzed in depth by ANOVA followed by Bonferroni multiple comparison post tests. We further evaluated whether plasma neurofilament light chain levels reflect neuropathological and behavioral changes observed in the experimental groups. While a treatment combining physical activity and caffeine supplementation significantly improved learning and memory function compared to standard-housed vehicle-treated Tg4-42 in tasks such as the Morris water maze, no major additive effect outperforming the effects of the single interventions was observed.
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Enfermedad de Alzheimer , Ratones , Animales , Enfermedad de Alzheimer/patología , Cafeína/farmacología , Cafeína/uso terapéutico , Ratones Transgénicos , Memoria , Aprendizaje por Laberinto , Modelos Animales de Enfermedad , Suplementos Dietéticos , Péptidos beta-Amiloides/farmacología , Precursor de Proteína beta-AmiloideRESUMEN
Amyloid-ß (Aß) peptides, including post-translationally modified variants thereof, are believed to play a key role in the onset and progression of Alzheimer's disease. Suggested modified Aß species with potential disease relevance include Aß peptides phosphorylated at serine in position eight (pSer8-Aß) or 26 (pSer26-Aß). However, the published studies on those Aß peptides essentially relied on antibody-based approaches. Thus, complementary analyses by mass spectrometry, as shown for other modified Aß variants, will be necessary not only to unambiguously verify the existence of phosphorylated Aß species in brain samples but also to reveal their exact identity as to phosphorylation sites and potential terminal truncations. With the aim of providing a novel tool for addressing this still-unresolved issue, we developed a customized matrix formulation, referred to as TOPAC, that allows for improved detection of synthetic phosphorylated Aß species by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. When TOPAC was compared with standard matrices, we observed higher signal intensities but minimal methionine oxidation and phosphate loss for intact pSer8-Aß(1-40) and pSer26-Aß(1-40). Similarly, TOPAC also improved the mass spectrometric detection and sequencing of the proteolytic cleavage products pSer8-Aß(1-16) and pSer26-Aß(17-28). We expect that TOPAC will facilitate future efforts to detect and characterize endogenous phosphorylated Aß species in biological samples and that it may also find its use in phospho-proteomic approaches apart from applications in the Aß field.
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Enfermedad de Alzheimer , Péptidos beta-Amiloides , Humanos , Péptidos beta-Amiloides/química , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Proteómica , Encéfalo/metabolismoRESUMEN
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.
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Enfermedad de Alzheimer , Humanos , Plasma , Biomarcadores , Curva ROC , EncéfaloRESUMEN
INTRODUCTION: Pesticides, including herbicides, are widely used for agricultural and sanitary reasons and concerns have been raised about their various health effects. Little research has been done into the extent to which agricultural land use in the residential surroundings contributes to (internal) exposure of pesticides. OBJECTIVES: We investigated the associations between the proportion of agricultural land use around the residence and the exposure to pesticides in adolescents in Flanders (Belgium). MATERIAL AND METHODS: We included 424 adolescents participating in the fourth Flemish Environment and Health Study (FLEHS IV) between 2016 and 2020. The residential address of all participants was geocoded and the proportion of agricultural land use around the residence was estimated in several buffers (300 m, 500 m, 1000 m and 2000 m). The concentrations of the following biomarkers of pesticides were measured in urine and adjusted for the specific gravity: glyphosate and its metabolite, aminomethyl-phosphonic acid (AMPA); 3-phenoxybenzoic acid (3-PBA); 3,5,6-trichloro-2-pyridinol (TCPy) and 2,4-dichlophenoxy-acetic acid (2,4-D). We categorized the pesticide biomarkers in three categories according to the exposure levels and used ordinal logistic regression models adjusted for sex, season and household education to estimate the odds ratio for an increase in an interquartile range (IQR) of proportion of agricultural land use. We also used binary logistic regression models in which the category of highest exposure was compared to the category of lowest exposure. In addition, we explored potential effect modification by sex and season. RESULTS: We found a significant association between the proportion of agricultural land use in a buffer of 2000 m around the residence and the levels of urinary AMPA divided into three categories (OR = 1.35 for an IQR increase in the proportion of agricultural land use around residence; 95% CI: 1.00-1.83). This association was less pronounced and not statistically significant for the other studied pesticides (OR ranging between 0.95 and 1.16). Stratified analysis showed the strongest association of the proportion of agricultural land use within 2000 m buffers for AMPA among boys (OR = 1.89; 95% CI: 1.19-3.04). Results using smaller buffers were comparable, but did not reach statistical significance. CONCLUSION: Our findings suggest that a higher proportion of agricultural land use around the residence might increase exposure to AMPA.
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Plaguicidas , Masculino , Adolescente , Humanos , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiónico/análisis , Plaguicidas/orina , Agricultura , Biomarcadores , Exposición a Riesgos Ambientales/análisis , GlifosatoRESUMEN
Neurochemical biomarkers can support the diagnosis of Alzheimer's disease and may facilitate clinical trials. In blood plasma, the ratio of the amyloid-ß (Aß) peptides Aß-3-40/Aß1-42 can predict cerebral amyloid-ß pathology with high accuracy (Nakamura et al., 2018). Whether or not Aß-3-40 (aka. amyloid precursor protein (APP) 669-711) is also present in cerebrospinal fluid (CSF) is not clear. Here, we investigated whether Aß-3-40 can be detected in CSF and to what extent the CSF Aß-3-40/Aß42 ratio is able to differentiate between individuals with or without amyloid-ß positron emission tomography (PET) evidence of brain amyloid. The occurrence of Aß-3-40 in human CSF was assessed by immunoprecipitation followed by mass spectrometry. For quantifying the CSF concentrations of Aß-3-40 in 23 amyloid PET-negative and 17 amyloid PET-positive subjects, we applied a sandwich-type immunoassay. Our findings provide clear evidence of the presence of Aß-3-40 and Aß-3-38 in human CSF. While there was no statistically significant difference in the CSF concentration of Aß-3-40 between the two diagnostic groups, the CSF Aß-3-40/Aß42 ratio was increased in the amyloid PET-positive individuals. We conclude that Aß-3-40 appears to be a regular constituent of CSF and may potentially serve to accentuate the selective decrease in CSF Aß42 in Alzheimer's disease.
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Enfermedad de Alzheimer , Enfermedad de Alzheimer/líquido cefalorraquídeo , Enfermedad de Alzheimer/diagnóstico por imagen , Amiloide , Péptidos beta-Amiloides/líquido cefalorraquídeo , Biomarcadores/líquido cefalorraquídeo , Humanos , Fragmentos de Péptidos/líquido cefalorraquídeo , Tomografía de Emisión de Positrones , Proteínas tau/líquido cefalorraquídeoRESUMEN
BACKGROUND/AIM: Glyphosate, a broad-spectrum herbicide, and its main metabolite aminomethylphosphonic acid (AMPA) are persistent in the environment. Studies showed associations between glyphosate or AMPA exposure and several adverse cellular processes, including metabolic alterations and oxidative stress. OBJECTIVE: To determine the association between glyphosate and AMPA exposure and biomarkers of biological aging. METHODS: We examined glyphosate and AMPA exposure, mtDNA content and leukocyte telomere length in 181 adults, included in the third cycle of the Flemish Environment and Health Study (FLEHSIII). DNA was isolated from leukocytes and the relative mtDNA content and telomere length were determined using qPCR. Urinary glyphosate and AMPA concentrations were measured by Gas Chromatography-Tandem Mass Spectrometry (GC-MS-MS). We used multiple linear regression models to associate mtDNA content and leukocyte telomere length with glyphosate or AMPA exposure while adjusting for confounding variables. RESULTS: A doubling in urinary AMPA concentration was associated with 5.19% (95% CI: 0.49 to 10.11; p = 0.03) longer leukocyte telomere length, while no association was observed with urinary glyphosate concentration. No association between mtDNA content and urinary glyphosate nor AMPA levels was observed. CONCLUSIONS: This study showed that AMPA exposure may be associated with telomere biology in adults.
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Herbicidas , Biomarcadores , Glicina/análogos & derivados , Herbicidas/orina , Organofosfonatos , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiónico , GlifosatoRESUMEN
BACKGROUND: Observational studies have linked pesticide exposure to various diseases, whereas organic food consumption has been associated with positive health outcomes. Organic farming standards prohibit the use of most pesticides, and organic food consumption may therefore reduce pesticide exposure. OBJECTIVES: To determine the effects of diet (Western compared with Mediterranean) and food type (conventional compared with organic) and sex on urinary pesticide residue excretion (UPRE), as well as associations between specific diet components and UPRE. METHODS: In this 2-wk, randomized dietary intervention trial, healthy adults were randomly allocated to an intervention (n = 13) or conventional (n = 14) group. Whereas participants in the intervention group consumed a Mediterranean diet (MedDiet) made entirely from organic foods, the conventional group consumed a MedDiet made entirely from conventional foods. Both groups consumed habitual Western diets made from conventional foods before and after the 2-wk intervention period. The primary outcome was UPRE. In addition, we assessed diet composition and pesticide residue profiles in foods eaten. Participants were aware of group assignment, but the study assessors were not. RESULTS: During the intervention period, total UPRE was 91% lower with organic (mean 17 µg/d; 95% CI: 15, 19) than with conventional (mean 180 µg/d; 95% CI: 153, 208) food consumption (P < 0.0001). In the conventional group, switching from the habitual Western diet to the MedDiet increased insecticide excretion from 7 to 25 µg/d (P < 0.0001), organophosphate excretion from 5 to 19 µg/d (P < 0.0001), and pyrethroid residue excretion from 2.0 to 4.5 µg/d (P < 0.0001). Small but significant effects of sex were detected for chlormequat, herbicide, and total pesticide residue excretion. CONCLUSIONS: Changing from a habitual Western diet to a MedDiet was associated with increased insecticide, organophosphate, and pyrethroid exposure, whereas organic food consumption reduced exposure to all groups of synthetic chemical pesticides. This may explain the positive health outcomes linked to organic food consumption in observational studies. This trial was registered at www.clinicaltrials.gov as NCT03254537.
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Dieta Mediterránea/efectos adversos , Dieta Occidental/efectos adversos , Exposición Dietética/efectos adversos , Alimentos Orgánicos/efectos adversos , Residuos de Plaguicidas/orina , Adulto , Femenino , Voluntarios Sanos , Humanos , Masculino , Plaguicidas/toxicidad , Factores Sexuales , Adulto JovenRESUMEN
Since the 1970s, glyphosate has become the most used herbicide of the world. The general population is ubiquitously exposed to glyphosate. Its long-term toxicity, carcinogenic potential and other health effects are controversially discussed. Even though the possible health impacts of glyphosate are of global concern, no population-wide monitoring of glyphosate was done yet. This study presents the worldwide first population-representative data on glyphosate and its metabolite aminomethylphosphonic acid (AMPA) for children and adolescents. 2144 first-morning void urine samples of 3-17-year-old children and adolescents living in Germany were analysed for concentrations of glyphosate and AMPA in the German Environmental Survey for Children and Adolescents 2014-2017 (GerESV). In 52 % of the samples (46 % for AMPA) the urinary glyphosate concentrations were above the limit of quantification of 0.1 µg/L. The geometric mean concentrations were 0.107 µg/L (0.090 µg/gcreatinine) for glyphosate and 0.100 µg/L (0.085 µg/gcreatinine) for AMPA. No clear association between exposure to glyphosate or AMPA and vegetarian diet or consumption of cereals, pulses, or vegetables could be identified. The low quantification rate and the 95th percentiles for glyphosate and AMPA of around 0.5 µg/L demonstrate an overall low exposure of the young population in Germany.
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Monitoreo Biológico , Herbicidas , Adolescente , Niño , Preescolar , Monitoreo del Ambiente , Alemania , Glicina/análogos & derivados , Humanos , Organofosfonatos , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiónico , GlifosatoRESUMEN
BACKGROUND: Alzheimer's disease (AD) is a neurodegenerative disorder associated with extracellular amyloid-ß peptide deposition and progressive neuron loss. Strong evidence supports that neuroinflammatory changes such as the activation of astrocytes and microglia cells are important in the disease process. Glycoprotein nonmetastatic melanoma protein B (GPNMB) is a transmembrane glycoprotein that has recently been associated with an emerging role in neuroinflammation, which has been reported to be increased in post-mortem brain samples from AD and Parkinson's disease patients. METHODS: The present study describes the partial "fit for purpose" validation of a commercially available immunoassay for the determination of GPNMB levels in the cerebrospinal fluid (CSF). We further assessed the applicability of GPNMB as a potential biomarker for AD in two different cohorts that were defined by biomarker-supported clinical diagnosis or by neuroimaging with amyloid positron emission tomography, respectively. RESULTS: The results indicated that CSF GPNMB levels could not distinguish between AD or controls with other neurological diseases but correlated with other parameters such as aging and CSF pTau levels. CONCLUSIONS: The findings of this study do not support GPNMB in CSF as a valuable neurochemical diagnostic biomarker of AD but warrant further studies employing healthy control individuals.
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Enfermedad de Alzheimer , Enfermedad de Alzheimer/diagnóstico por imagen , Péptidos beta-Amiloides , Biomarcadores , Glicoproteínas , Humanos , Glicoproteínas de Membrana , Microglía , Fragmentos de Péptidos , Proteínas tauRESUMEN
The collaborative cross (CC) is a large panel of mouse-inbred lines derived from eight founder strains (NOD/ShiLtJ, NZO/HILtJ, A/J, C57BL/6J, 129S1/SvImJ, CAST/EiJ, PWK/PhJ, and WSB/EiJ). Here, we performed a comprehensive and comparative phenotyping screening to identify phenotypic differences and similarities between the eight founder strains. In total, more than 300 parameters including allergy, behavior, cardiovascular, clinical blood chemistry, dysmorphology, bone and cartilage, energy metabolism, eye and vision, immunology, lung function, neurology, nociception, and pathology were analyzed; in most traits from sixteen females and sixteen males. We identified over 270 parameters that were significantly different between strains. This study highlights the value of the founder and CC strains for phenotype-genotype associations of many genetic traits that are highly relevant to human diseases. All data described here are publicly available from the mouse phenome database for analyses and downloads.
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Ratones Endogámicos/genética , Fenotipo , Animales , Ratones de Colaboración Cruzada/genética , Bases de Datos Genéticas , Femenino , Estudios de Asociación Genética , Genotipo , Masculino , Ratones , Sitios de Carácter Cuantitativo , Especificidad de la EspecieRESUMEN
Astrocytes may not only be involved in the clearance of Amyloid beta peptides (Aß) in Alzheimer's disease (AD), but appear to produce N-terminally truncated Aß (Aßn-x) independently of BACE1, which generates the N-Terminus of Aß starting with Asp1 (Aß1-x). A candidate protease for the generation of Aßn-x is cathepsin B (CatB), especially since CatB has also been reported to degrade Aß, which could explain the opposite roles of astrocytes in AD. In this study, we investigated the influence of CatB inhibitors and the deletion of the gene encoding CatB (CTSB) using CRISPR/Cas9 technology on Aß2-x and Aß1-x levels in cell culture supernatants by one- and two-dimensional Urea-SDS-PAGE followed by immunoblot. While the cell-permeant inhibitors E64d and CA-074 Me did not significantly affect the Aß1-x levels in supernatants of cultured chicken and human astrocytes, they did reduce the Aß2-x levels. In the glioma-derived cell line H4, the Aß2-x levels were likewise decreased in supernatants by treatment with the more specific, but cell-impermeant CatB-inhibitor CA-074, by CA-074 Me treatment, and by CTSB gene deletion. Additionally, a more than 2-fold increase in secreted Aß1-x was observed under the latter two conditions. The CA-074 Me-mediated increase of Aß1-x, but not the decrease of Aß2-x, was influenced by concomitant treatment with the vacuolar H+-ATPase inhibitor Bafilomycin A1. This indicated that non-lysosomal CatB mediated the production of Aß2-x in astrocytes, while the degradation of Aß1-x seemed to be dependent on lysosomal CatB in H4 cells, but not in primary astrocytes. These findings highlight the importance of considering organelle targeting in drug development to promote Aß degradation.
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OBJECTIVE: Diverticular disease is a common complex disorder characterised by mucosal outpouchings of the colonic wall that manifests through complications such as diverticulitis, perforation and bleeding. We report the to date largest genome-wide association study (GWAS) to identify genetic risk factors for diverticular disease. DESIGN: Discovery GWAS analysis was performed on UK Biobank imputed genotypes using 31 964 cases and 419 135 controls of European descent. Associations were replicated in a European sample of 3893 cases and 2829 diverticula-free controls and evaluated for risk contribution to diverticulitis and uncomplicated diverticulosis. Transcripts at top 20 replicating loci were analysed by real-time quatitative PCR in preparations of the mucosal, submucosal and muscular layer of colon. The localisation of expressed protein at selected loci was investigated by immunohistochemistry. RESULTS: We discovered 48 risk loci, of which 12 are novel, with genome-wide significance and consistent OR in the replication sample. Nominal replication (p<0.05) was observed for 27 loci, and additional 8 in meta-analysis with a population-based cohort. The most significant novel risk variant rs9960286 is located near CTAGE1 with a p value of 2.3×10-10 and 0.002 (ORallelic=1.14 (95% CI 1.05 to 1.24)) in the replication analysis. Four loci showed stronger effects for diverticulitis, PHGR1 (OR 1.32, 95% CI 1.12 to 1.56), FAM155A-2 (OR 1.21, 95% CI 1.04 to 1.42), CALCB (OR 1.17, 95% CI 1.03 to 1.33) and S100A10 (OR 1.17, 95% CI 1.03 to 1.33). CONCLUSION: In silico analyses point to diverticulosis primarily as a disorder of intestinal neuromuscular function and of impaired connective fibre support, while an additional diverticulitis risk might be conferred by epithelial dysfunction.