311 research outputs found

    Tau inhibits mitochondrial calcium efflux and makes neurons vulnerable to calciuminduced cell death

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    Aggregation or phosphorylation of the microtubule-associated protein tau is the pathological hallmark in a number of diseases termed tauopathies, which include the most common neurodegenerative disorder, Alzheimer’s disease; or frontotemporal dementia, linked to mutations in the gene MAPT encoding tau. Although misfolded tau has strong familial and histopathological (as in intracellular tangles) association with neurodegenerative disorders, the cellular mechanism of tau-induced pathology remains to be controversial. Here we studied the effect of tau on the cytosolic and mitochondrial calcium homeostasis using primary cortical cultures treated with the protein and iPSC-derived neurons bearing the 10 + 16 MAPT mutation linked to frontotemporal dementia. We found that incubation of the primary cortical co-cultures of neurons and astrocytes with tau induced spontaneous Ca2+ oscillations in the neurons, which were also observed in iPSC-neurons with the 10 + 16 MAPT mutation. Importantly, tau inhibited mitochondrial calcium efflux via the mitochondrial Na+/Ca2+ exchanger (NCLX) in both neurons and astrocytes. This inhibition led to mitochondrial depolarisation in response to physiological and pathological calcium stimuli and made these cells vulnerable to calcium-induced caspase 3 activation and cell death. Thus, inhibition of the mitochondrial NCLX in neurons with misfolded or mutated tau can be involved in the mechanism of neurodegeneration.EB was supported with an EMBO short-term fellowship (number 7834) for the development of this project. The work was supported by EPSRC grant EP/R024898/1

    Passive transfer status and growth performance in newborn buffalo calves allowed to nurse the dam

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    The objective of this study was to evaluate the effect of passive transfer status, determined by measuring serum IgG concentration 24 hours after parturition, on growth performance in buffalo calves fed milk replacer or allowed to nurse the dam during the first month of life. Experiment consisted of 24 healthy buffalo calves from birth to 30 days old. Significant quadratic associations were detected between serum IgG concentration 24 hours after birth and day-30 weight (P < 0.05; R2 = 0.62) and between serum IgG concentration 24 hours after birth and the mean daily gain from birth to day 30 (P < 0.01; R2 = 0.74) in buffalo calves allowed to nurse the dam. No significant association was detected between serum IgG concentration 24 hours after birth and measures of growth performance in buffalo calves fed milk replacer. Results indicated that passive transfer status, determined as serum IgG concentration 24 hours after birth, was a significant source of variation in growth performance when buffalo calves nursed the dam. Maximizing passive transfer of immunity by allowing buffalo calves to nurse the dam increased the growth performance during the first month of life

    Gut&#8211;brain axis and neurodegeneration : State-of-the-art of meta-omics sciences for microbiota characterization

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    Recent advances in the field of meta-omics sciences and related bioinformatics tools have allowed a comprehensive investigation of human-associated microbiota and its contribution to achieving and maintaining the homeostatic balance. Bioactive compounds from the microbial community harboring the human gut are involved in a finely tuned network of interconnections with the host, orchestrating a wide variety of physiological processes. These includes the bidirectional crosstalk between the central nervous system, the enteric nervous system, and the gastrointestinal tract (i.e., gut\u2013brain axis). The increasing accumulation of evidence suggest a pivotal role of the composition and activity of the gut microbiota in neurodegeneration. In the present review we aim to provide an overview of the state-of-the-art of meta-omics sciences including metagenomics for the study of microbial genomes and taxa strains, metatranscriptomics for gene expression, metaproteomics and metabolomics to identify and/or quantify microbial proteins and metabolites, respectively. The potential and limitations of each discipline were highlighted, as well as the advantages of an integrated approach (multi-omics) to predict microbial functions and molecular mechanisms related to human diseases. Particular emphasis is given to the latest results obtained with these approaches in an attempt to elucidate the link between the gut microbiota and the most common neurodegenerative diseases, such as multiple sclerosis (MS), Alzheimer\u2019s disease (AD), Parkinson\u2019s disease (PD), and amyotrophic lateral sclerosis (ALS)

    Relative echogenicity of tendons and ligaments of the palmar metacarpal region in foals from birth to 4 months of age: A longitudinal study

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    The objective of this study was to evaluate relative echogenicity of superficial and deep digital flexor tendons, the accessory ligament of the deep digital flexor tendon and interosseous muscle of the metacarpal region in foals ages 1 week to 4 months; and assess the association between echogenicity and sex or side/laterality. Seven Standardbred trotter foals were examined. Right and left metacarpal regions (palmar surface) were ultrasonographically investigated, and four regions of interest were assessed. A significant increase in echogenicity was seen in superficial and deep digital flexor tendons, accessory ligament of deep digital flexor tendon, and interosseous muscle during growth from 1 week to 4 months of age. Echogenicity of examined tendons and ligaments was not influenced by gender nor laterality. Reference values for tendon and ligament echogenicity could function as a tool to discriminate between physiological and abnormal conditions such as congenital contractural conditions

    Evaluation of the capillary electrophoresis method for measurement of immunoglobulin concentration in ewe colostrum

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    ABSTRACT Capillary electrophoresis (CE) is a technique routinely used in clinical laboratories that allows the separation and quantification of blood serum proteins in a rapid, precise, accurate, and inexpensive manner. Recently, CE has been proposed to separate and measure colostral proteins, but an evaluation of the agreement between CE and radial immunodiffusion (RID) method, currently used to quantify IgG in colostrum, is still lacking. The purpose of this study was to test the ability of a CE instrument, normally used in blood serum protein analysis, to realize the correct quantification of total Ig concentration in ewe colostrum, using RID assay as reference. Colostrum samples (n = 68) were collected from 35 multiparous Sarda ewes at first milking (n = 33) and at 24 h postpartum (n = 35). The mean ± standard deviation of IgG concentration measured by RID and whey colostrum total Ig concentration measured by CE were 54.76 ± 41.82 g/L and 54.70 ± 41.43 g/L, respectively. Lin's concordance correlation coefficient (r = 0.993; 95% confidence interval=0.989 to 0.996) and linear regression analysis results (RID = 1.0022CE − 0.063; R 2 = 0.986) showed an excellent agreement between these 2 methods. Bland-Altman analysis confirmed that CE method can be a suitable alternative to RID: the mean of the differences between CE and RID was −0.055 ± 4.95 g/L (95% confidence interval=−1.25 to 1.14 g/L) and the agreement limits were −9.75 to 9.60 g/L (low limit 95% confidence interval=−11.82 to −7.68 g/L; high limit 95% confidence interval=7.57 to 11.72 g/L). In conclusion, the current study indicates that CE method may be a reliable tool for the quantification of the total Ig concentration in ewe colostrum

    Three combinations of clonidine in association with tiletamine-zolazepam for anaesthesia induction in rats: evaluation of reflexes and pain sensibility

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    The aim of this study was to assess the combination of tiletamine-zolazepam (Zoletil 20\uae) with three different doses of clonidine for general anaesthesia induction in rats submitted to vascular microsurgery. The evaluation of anaesthetic and analgesic effects was performed in 30 Wistar rats randomly divided into three groups and induced with Zoletil 20 [90 mg/kg Intraperitoneal (IP)] associated with three different doses of clonidine (60\u201390\u2013120 \u3bcg/kg IP). Four clinical parameters were evaluated after induction: loss of righting reflex, voluntary movement, the pedal withdrawal response, and pain sensitivity tested by pinching the tail. The combination of Zoletil with 90 and 120 \u3bcg/kg of clonidine provided a surgical anaesthesia; however, 90 \u3bcg/kg of clonidine provided the most rapid anaesthesia induction, as confirmed by data obtained by clinical evaluation of the loss of the pedal withdrawal response and the absence of the tail pinch response. The increase in dose of clonidine did not lead to a more rapid action of the \u3b12 agonist, probably due to achievement of a dose-dependent plateau

    Detection of buffalo milk adulteration with cow milk by capillary electrophoresis analysis.

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    The addition of cow milk during the production of buffalo mozzarella is a common fraud in dairy industries because of the lower price and greater availability of cow milk throughout the year. The aim of this study was to develop a new, rapid, and robust capillary electrophoresis method for detecting and quantifying cow milk in buffalo milk by exploiting cow α-lactalbumin as a marker of adulteration. In particular, a linear calibration curve was generated, using a training set of calibrators consisting of 7 series of 17 buffalo/bovine whey mixtures, obtained after casein precipitation, with increasing percentages of cow whey. The capillary electrophoresis method showed high linearity (R2 = 0.968), repeatability [relative standard deviation (RSD) = 2.11, 3.02, 4.38, and 1.18%, respectively for 5, 10, 20, and 50% of buffalo/bovine whey mixtures], and intermediate precision (RSD = 2.18, 2.49, 5.09, and 3.19%, respectively, for 5, 10, 20, and 50% buffalo/bovine whey mixtures). Moreover, the minimum amount of detectable fraudulent cow milk was 1%, and the limit of quantification was 3.1%
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