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

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 × 1010 mEVs mL−1) were 2.3-fold higher than for uninfected controls (0.51 × 1010 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 (10 mEVs mL−1) and the elderly (>45 yo) (median:1.92 × 1010 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 p 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

Global Prevalence of Gestational Diabetes Mellitus: A Systematic Review and Meta-Analysis

1. Abstract 1.1. Background: Evidence suggests that diabetes in all forms are on the rise especially gesta-tional diabetes mellitus which increases the risk of maternal and neonatal morbidities; however global prevalence rates and geographical distribution of GDM remain uncertain. The aim of this study is to examine the global burden of gestational diabetes mellitus. 1.2. Methods: A systematic review and meta-analysis of studies reporting Randomised Clinical Trials (RCTs) in pregnant women who have GDM was conducted. Cochrane (Central), PubMed, Scopus, JBI, Medline, EMBASE and reference lists of retrieved studies were searched from inception to March 2019. Publications on prevalence of GDM irrespective of the baseline criteria used to diagnose GDM were included in the study. Studies were limited to English language, randomised control trials and women aged between 19-44 years inclusive. 1.3. Results: Eleven RCTs met the inclusion criteria for this review. The included studies collectively reported GDM rates of 13,450 pregnant women from 7 countries. The diagnostic criteria used in the studies were World Health Organisation (WHO) 1985 and 1999, International Association of Diabetes, Pregnancy Study Group (IADPSG), National Diabetes Data Group (NDDG), Carpenter-Coustan (C&C) and O'Sullivan's criteria. Seven RCTs screened for GDM in comparison with different diagnostic criteria in the same population while three studies used the same criteria for different groups. One study compared 100g, 3h OGTT to 75g, 2h OGTT for diagnosing GDM using Carpenter and Coustan criteria. All seven RCTs that compared different diagnostic criteria in the same population detected different prevalence rates of GDM. Three RCTs measured prevalence of GDM in the same population using WHO 1999 and IADPSG 2013 criteria. Using random effect model, data from three studies that compared IADPSG criteria to WHO 1999 showed an Odds Ratio (OR) of 0.52(0.15, 1.84), 95% Confidence Interval (CI) and high heterogeneity of 99%. In all three studies, prevalence of GDM measured by IADPSG criteria was higher than WHO 1999 criteria, although not significant (p= 0.31). Combining all the studies gave a global estimated prevalence of GDM to be 10.13% (95% CI, 7.33-12.94) with moderate heterogeneity of 27%. The highest prevalence of GDM wit

Inhibition of microvesiculation sensitizes prostate cancer cells to chemotherapy and reduces docetaxel dose required to limit tumor growth in vivo

This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/Microvesicles shed from cells carry constituents of the cell cytoplasm, including, of importance in multidrug resistance to cancer chemotherapy, drugs that the tumor cell attempts to efflux. To see whether such drugs could be used at lower concentrations with the same efficacy, it was first shown that microvesiculation of prostate cancer (PCa) cells, PC3, could be inhibited pharmacologically with calpeptin (calpain inhibitor) and by siRNA (CAPNS1). In cells treated with docetaxel (DTX), this inhibition resulted in a third-fold increase in intracellular concentrations of DTX. As a result, 20-fold lower concentrations of DTX (5 nM) could be used, in the presence of calpeptin (20μM) inducing the same degree of apoptosis after 48 h in PC3 cells, as 100 nM of DTX alone. Inhibition of microvesiculation similarly improved combination chemotherapy (DTX and methotrexate). In a mouse xenograft model of PCa, DTX (0.1 mg/kg) together with calpeptin (10 mg/kg), administered i.p., significantly reduced tumor volumes compared to DTX alone (0.1 mg/kg) and brought about the same reductions in tumor growth as 10 mg/kg of DTX alone. As well as further reducing vascularization, it also increased apoptosis and reduced proliferation of PC3 cells in tumor xenografts.Peer reviewe

Microvesicles released constitutively from prostate cancer cells differ biochemically and functionally to stimulated microvesicles released through sublytic C5b-9

We have classified microvesicles into two subtypes: larger MVs released upon stimulation of prostate cancer cells, sMVs, and smaller cMVs, released constitutively. cMVs are released as part of cell metabolism and sMVs, released at 10-fold higher levels, produced upon activation, including sublytic C5b-9. From electron microscopy, nanosight tracking analysis, dynamic light scattering and flow cytometry, cMVs (194-210 nm in diameter) are smaller than sMVs (333-385 nm). Furthermore, using a Quartz Crystal Microbalance measuring changes in resonant frequency (Δf) that equate to mass deposited on a sensor, an sMV and a cMV are estimated at 0.267 and 0.241 pg, respectively. sMVs carry more calcium and protein, express higher levels of lipid rafts, GPI-anchored CD55 and phosphatidylserine including deposited C5b-9 compared to cMVs. This may allude to biological differences such as increased bound C4BP on sMVs inhibiting complement more effectively.Peer reviewe

Label-free real-time acoustic sensing of microvesicle release from prostate cancer (PC3) cells using a Quartz Crystal Microbalance

Using a Quartz Crystal Microbalance with dissipation monitoring, QCM-D (label-free system) measuring changes in resonant frequency (Δf) that equate to mass deposited on a sensor, we showed the attachment, over a 60 min period, of a monolayer of PC3 cells to the gold electrodes of the quartz crystal sensor, which had been rendered hydrophilic. That MVs were released upon BzATP stimulation of cells was confirmed by NTA analysis (average 250 nm diameter), flow cytometry, showing high phosphatidylserine exposition and by fluorescent (Annexin V Alexa Fluor® 488-positive) and electron microscopy. Over a period of 1000s (16.7 min) during which early apoptosis increased from 4% plateauing at 10% and late apoptosis rose to 2%, the Δf increased 20 Hz, thereupon remaining constant for the last 1000s of the experiment. Using the Sauerbrey equation, the loss in mass, which corresponded to the release of 2.36 × 106 MVs, was calculated to be 23 ng. We therefore estimated the mass of an MV to be 0.24 pg. With the deposition on the QCM-D of 3.5 × 107 MVs over 200s, the decrease in Δf (Hz) gave an estimate of 0.235 pg per MV.Peer reviewe

Blood/plasma secretome and microvesicles

A major but hitherto overseen component of the blood/plasma secretome is that of extracellular vesicles (EVs) which are shed from all blood cell types. These EVs are made up of microvesicles (MVs) and exosomes. MVs, 100nm-1μm in diameter, are released from the cell surface, and are a rich source of non-conventionally secreted proteins lacking a conventional signal peptide, and thus not secreted by the classical secretory pathways. Exosomes are smaller vesicles (≤100nm) having an endocytic origin and released upon multivesicular body fusion with the plasma membrane. Both vesicle types play major roles in intercellular cross talk and constitute an important component of the secretome especially in the area of biomarkers for cancer. The release of EVs, which are found in all the bodily fluids, is enhanced in cancer and a major focus of cancer proteomics is therefore targeted at EVs. The blood/plasma secretome is also a source of EVs, potentially diagnostic of infectious disease, whether from EVs released from infected cells or from the pathogens themselves. Despite the great excitement in this field, as is stated here and in other parts of this Special issue entitled: An Updated Secretome, much of the EV research, whether proteomic or functional in nature, urgently needs standardisation both in terms of nomenclature and isolation protocols. This article is part of a Special Issue entitled: An Updated Secretome

Red cell PMVs, plasma membrane-derived vesicles calling out for standards

Plasma membrane-derived vesicles (PMVs) or microparticles are vesicles (0.1–1 μm in diameter) released from the plasma membrane of all blood cell types under a variety of biochemical and pathological conditions. PMVs contain cytoskeletal elements and some surface markers from the parent cell but lack a nucleus and are unable to synthesise macromolecules. They are also defined on the basis that in most cases PMVs express varying amounts of the cytosolic leaflet lipid phosphatidylserine, which is externalised during activation on their surface. This marks the PMV as a biologically distinct entity from that of its parent cell, despite containing surface markers from the original cell, and also explains its role in events such as phagocytosis and thrombosis. There is currently a large amount of variation between investigators with regard to the pre-analytical steps employed in isolating red cell PMVs or RPMVs (which are slightly smaller than most PMVs), with key differences being centrifugation and sample storage conditions, which often leads to result variability. Unfortunately, standardization of preparation and detection methods has not yet been achieved. This review highlights and critically discusses the variables contributing to differences in results obtained by investigators, bringing to light numerous studies of which RPMVs have been analysed but have not yet been the subject of a review