Plasma mEV levels in Ghanain malaria patients with low parasitaemia are higher than those of healthy controls, raising the potential for parasite markers in mEVs as diagnostic targets

© 2019 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group on behalf of The International Society for Extracellular Vesicles. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial License (http://creativecommons.org/licenses/by-nc/4.0/), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.This study sought to measure medium-sized extracellular vesicles (mEVs) in plasma, when patients have low Plasmodium falciparum early in infection. We aimed to define the relationship between plasma mEVs and: (i) parasitaemia, (ii) period from onset of malaria symptoms until seeking medical care (patient delay, PD), (iii) age and (iv) gender. In this cross-sectional study, n = 434 patients were analysed and Nanosight Tracking Analysis (NTA) used to quantify mEVs (vesicles of 150–500 nm diameter, isolated at 15,000 × g, β-tubulin-positive and staining for annexin V, but weak or negative for CD81). Overall plasma mEV levels (1.69 × 10 10 mEVs mL −1) were 2.3-fold higher than for uninfected controls (0.51 × 10 10 mEVs mL −1). Divided into four age groups, we found a bimodal distribution with 2.5- and 2.1-fold higher mEVs in infected children (45 yo) (median:1.92 × 10 10 mEVs mL −1), respectively, compared to uninfected controls; parasite density varied similarly with age groups. There was a positive association between mEVs and parasite density (r = 0.587, p < 0.0001) and mEVs were strongly associated with PD (r = 0.919, p < 0.0001), but gender had no effect on plasma mEV levels (p = 0.667). Parasite density was also exponentially related to patient delay. Gender (p = 0.667) had no effect on plasma mEV levels. During periods of low parasitaemia (PD = 72h), mEVs were 0.93-fold greater than in uninfected controls. As 75% (49/65) of patients had low parasitaemia levels (20–500 parasites µL −1), close to the detection limits of microscopy of Giemsa-stained thick blood films (5–150 parasites µL −1), mEV quantification by NTA could potentially have early diagnostic value, and raises the potential of Pf markers in mEVs as early diagnostic targets.Peer reviewe

Real time analysis of microvesiculation using a Quartz Crystal Microbalance

Introduction: Characterization of microvesicles (MVs) is essential for understanding their mechanisms of action and biological importance. Stimulated MVs (sMVs) are released through the activation of cells by a multitude of factors. We aimed to use a quartz crystal microbalance (QCM) or piezoelectric quartz resonator able to determine small mass changes, to monitor MV release and to determine MV mass. Methods: A QCM (Q-Sence E1) was used to analyse MV release from THP-1 leukaemic promonocytes. The cells in RPMI and 2 mM Ca2_ were applied to the QCM to establish a steady baseline. The sample on the sensor was stimulated to microvesiculate with 10% exosome- and MV-free normal human serum. The QCM was then able to monitor sample density and fluid rigidity. Over the same time frame, the level of apoptosis of cells releasing MVs was assessed by staining with annexin V and 7-aminoactinomycin D (Guava Nexin Reagent). Using the QCM we were also able to measure MV mass directly by measuring their ability to quench the oscillating momentum of the QCM. Results: Using the QCM, we were able to monitor deposition of cells on the crystal and then sMV release from cells, in the absence of any labelling or fluorescent probe, by measuring cell mass change. Cells (105) were deposited onto the QCM electrodes, and the frequency decreases over the first 1000s indicating attachment. The cells were then stimulated with 10% EV-free NHS in RPMI and Ca2_ (2 mM) or, as a control, with heat inactivated NHS. During the ensuing 6.5 min, the resonate frequency remained stable. Then, over the following 10 min there was a 30 Hz increase indicating a loss in mass, consistent with the high rate of sMV observed. Given the crystal constant, C as 17.7, ^f as 19 Hz and v (the third overtone) as 3, and with the crystal area at 0.2 cm2, using the Sauerbrey equation we calculated the mass loss to be 23 ng which corresponded to 0.25 pg per MV given that 0.92 _ 105 MVs were released. The 16 min period over which MVs continue to be released as determined on the QCM coincides with the MV increase measured by FACS and with an increase in early apoptosis from 4% plateauing at 10%, levels of late apoptosis remaining at 1_3%. We also looked at deposition of sMV on the sensor. Given a Df of 27197 Hz for the deposition of 1.3_106 sMVs, we estimate the mass of an sMV by this approach as 0.24190.006 pg. Summary/conclusion: Using the QCM we were able to measure a significant change in cellular mass, beginning at 6.5 min post-stimulus and peaking at 1000 s post-stimulus. The QCM also detected a decrease in media fluidity, attributed to the process of membrane blebbing on THP-1 and MV release. The QCM was able to provide an accurate measurement of sMV mass (0.25 pg) by calculating the loss in mass of the stimulated cells. By measuring the quenching of the oscillating momentum on the QCM as sMVs are deposited on the sensor, we were also able to calculate the mass of an sMV as 0.24 pg

Characterisation of microvesicles released from cells constitutively and upon stimulation

Constitutively released microvesicles (cMVs) are released as a part of normal cell physiology and this is summarised in Fig. 1 (1). However stimulated microvesicles (sMVs) are released as a result of a number of possible stress factors (2, 3). We found sMVs to be released in higher numbers than cMVs, typically ten-fold higher numbers, in the same time frame, and where the stress factor was a pharmacological agent, the microvesiculation was an attempt to release this chemical stress factor. Using a mass sensing technique, the sMVs were released over a 15 min period after stimulation. Using sizing beads on a flow cytometer and by transmission electron microscopy the cMVs were typically smaller (less than 300 nm in diameter) than sMVs (300-500 nm in diameter). However cMVs were found to carry more protein. By contrast, phosphatidylserine expression was greater on the larger sMVs, which also more effectively inhibited complement-mediated lysis

Managing without Authority: Records Managers in Interorganizational Contexts

Information professionals are taking on new roles in modern organizations. Specifically, these professionals are tasked with gaining coworkers’ compliance with information communication and management policies. However, they often lack the formal authority of traditional managers. We report on preliminary findings from a qualitative study of records managers, focusing on the interpersonal skills they use to achieve compliance.ye

The Met Office Unified Model Global Atmosphere 6.0/6.1 and JULES Global Land 6.0/6.1 configurations

We describe Global Atmosphere 6.0 and Global Land 6.0: the latest science configurations of the Met Office Unified Model and JULES land surface model developed for use across all timescales. Global Atmosphere 6.0 includes the ENDGame dynamical core, which significantly increases mid-latitude variability improving a known model bias. Alongside developments of the model’s physical parametrisations, ENDGame also increases variability in the tropics, which leads to an improved representation of tropical cyclones and other tropical phenomena. Further developments of the atmospheric and land surface parametrisations improve other aspects of model performance, including the forecasting of surface weather phenomena. We also describe Global Atmosphere 6.1 and Global Land 6.1, which include a small number of long-standing differences from our main trunk configurations that we continue to require for operational global weather prediction. Since July 2014, GA6.1/GL6.1 has been used by the Met Office for operational global NWP, whilst GA6.0/GL6.0 was implemented in its remaining global prediction systems over the following year

Associations of ATR and CHEK1 Single Nucleotide Polymorphisms with Breast Cancer

DNA damage and replication checkpoints mediated by the ATR-CHEK1 pathway are key to the maintenance of genome stability, and both ATR and CHEK1 have been proposed as potential breast cancer susceptibility genes. Many novel variants recently identified by the large resequencing projects have not yet been thoroughly tested in genome-wide association studies for breast cancer susceptibility. We therefore used a tagging SNP (tagSNP) approach based on recent SNP data available from the 1000 genomes projects, to investigate the roles of ATR and CHEK1 in breast cancer risk and survival. ATR and CHEK1 tagSNPs were genotyped in the Sheffield Breast Cancer Study (SBCS; 1011 cases and 1024 controls) using Illumina GoldenGate assays. Untyped SNPs were imputed using IMPUTE2, and associations between genotype and breast cancer risk and survival were evaluated using logistic and Cox proportional hazard regression models respectively on a per allele basis. Significant associations were further examined in a meta-analysis of published data or confirmed in the Utah Breast Cancer Study (UBCS). The most significant associations for breast cancer risk in SBCS came from rs6805118 in ATR (p=7.6x10-5) and rs2155388 in CHEK1 (p=3.1x10-6), but neither remained significant after meta-analysis with other studies. However, meta-analysis of published data revealed a weak association between the ATR SNP rs1802904 (minor allele frequency is 12%) and breast cancer risk, with a summary odds ratio (confidence interval) of 0.90 (0.83-0.98) [p=0.0185] for the minor allele. Further replication of this SNP in larger studies is warranted since it is located in the target region of 2 microRNAs. No evidence of any survival effects of ATR or CHEK1 SNPs were identified. We conclude that common alleles of ATR and CHEK1 are not implicated in breast cancer risk or survival, but we cannot exclude effects of rare alleles and of common alleles with very small effect sizes

Effects of acute and chronic exercise on immunological parameters in the elderly aged: can physical activity counteract the effects of aging?

Immunosenescence is characterized by deterioration of the immune system caused by aging which induces changes to innate and adaptive immunity. Immunosenescence affects function and phenotype of immune cells, such as expression and function of receptors for immune cells which contributes to loss of immune function (chemotaxis, intracellular killing). Moreover, these alterations decrease the response to pathogens, which leads to several age-related diseases including cardiovascular disease, Alzheimer's disease, and diabetes in older individuals. Furthermore, increased risk of autoimmune disease and chronic infection is increased with an aging immune system, which is characterized by a pro-inflammatory environment, ultimately leading to accelerated biological aging. During the last century, sedentarism rose dramatically, with a concomitant increase in certain type of cancers (such as breast cancer, colon, or prostate cancer), and autoimmune disease. Numerous studies on physical activity and immunity, with focus on special populations (i.e., people with diabetes, HIV patients) demonstrate that chronic exercise enhances immunity. However, the majority of previous work has focused on either a pathological population or healthy young adults whilst research in elderly populations is scarce. Research conducted to date has primarily focused on aerobic and resistance exercise training and its effect on immunity. This review focuses on the potential for exercise training to affect the aging immune system. The concept is that some lifestyle strategies such as high-intensity exercise training may prevent disease through the attenuation of immunosenescence. In this context, we take a top-down approach and review the effect of exercise and training on immunological parameters in elderly at rest and during exercise in humans, and how they respond to different modes of training. We highlight the impact of these different exercise modes on immunological parameters, such as cytokine and lymphocyte concentration in elderly individuals

Extracellular Vesicles from the Myocyte Secretome Contribute In Vitro to Creating an Unfavourable Environment for Migrating Lung Carcinoma Cells

Cancer progression in skeletal muscle (SkM) is very rare, and mechanisms remain unclear. This study assessed the potential of SkM (myocyte)-derived EVs (C2C12-EVs) as anti-cancer agents. Using murine in vitro models, we showed that following treatment with C2C12-EVs, lung carcinoma cells failed to colonise SkM cells, and that C2C12-EVs selectively exerted apoptosis on cancer cells. Uptake of C2C12-EVs by carcinoma cells caused changes in lysosomal function and mitochondrial membrane properties inducing cell death with elevated caspase 3 and 9. The C2C12-EVs also inhibited cell proliferation, affecting cell cycle arrest at S phase and inhibited cell migration. Proteomic analysis of C2C12-EV cargoes highlighted functional enrichment pathways involved in lysozyme function, HIF-1 and PI3K-Akt signalling, regulation of actin cytoskeleton, pyruvate metabolism, platelet activation, and protein processing in ER. Decorin, a muscle cell-specific cytokine released from myocytes in response to stress, was significantly enriched in C2C12-EVs and may contribute to C2C12-EVs’ inhibitory activity on cancer cells. C2C12-EVs may suppress cancer and potentially be used as therapeutic agents for cancer metastasis