[Personalized treatment options for spinal muscular atrophy]

<p>Spinal muscular atrophy (SMA) is an autosomal recessive disease leading to progressive muscle weakness and atrophy, in severe cases also affecting the bulbar and respiratory muscles.The clinical spectrum of the disease is extremely variable, in the most severe cases resulting in perinatal death, while at the least severe end of the spectrum causing some motor deficits in old age without the loss of ambulation. Spinal muscular atrophy care has changed dramatically in recent years due to the availability of new therapeutic options.&nbsp;<br>The FDA approved nusinersen in 2016, this was followed by the approval of onasemnogene abeparvovec in 2019 and risdiplam in 2020. The EMA approved all three therapies a year later. Two of the threapies work at the pre-mRNA level, one at the DNA level. The clinical studies leading to the approval of the three drugs included patients of different ages and clinical conditions, and utilised partly different motor and functional scales. Therefore, direct comparison of these clinical studies is not possible. However, an increasing amount of real-world data contribute to the better understanding of the efficacy of the different therapies for patients of different ages and clinical conditions, in a real-world setting. Thus, the question may arise &ldquo;Which is the best SMA therapy?&rdquo;. This is an impossible question to answer. Indeed the question &ldquo;Which therapy is the most suitable for a certain patient at a certain time?&rdquo; is much more realistic. Here, we provide a brief overview of the objectively measurable results of the three therapies to date and an outlook into future therapeutic avenues.&nbsp;</p>.

Detection and proteomic characterization of extracellular vesicles in human pancreatic juice

AIMS

The prognosis of patients with pancreatic cancer has remained virtually unchanged with a high mortality rate compared to other types of cancers. An earlier detection would provide a time window of opportunity for treatment and prevention of deaths. In the present study we investigated extracellular vesicle (EV)-associated potential biomarkers for pancreatic cancer by directly assessing EV size-based subpopulations in pancreatic juice samples of patients with chronic pancreatitis or pancreatic cancer. In addition, we also studied blood plasma and pancreatic cancer cell line-derived EVs.

METHODS

Comparative proteomic analysis was performed of 102 EV preparations from human pancreatic juices, blood, and pancreatic cancer cell lines Capan-1 and MIA PaCa-2. EV preparations were also characterized by electron microscopy, tunable resistive pulse sensing, and flow cytometry.

RESULTS

Here we describe the presence of EVs in human pancreatic juice samples. Pancreatic juice EV-associated proteins that we identified as possible candidate markers for pancreatic cancer included mucins, such as MUC1, MUC4, MUC5AC, MUC6 and MUC16, CFTR, and MDR1 proteins. These candidate biomarkers could also be detected by flow cytometry in EVs found in pancreatic juice and those secreted by pancreatic cancer cell lines.

CONCLUSIONS

Together our data show that detection and characterization of EVs directly in pancreatic juice is feasible and may prove to be a valuable source of potential biomarkers of pancreatic cancer.

Improved characterization of EV preparations based on protein to lipid ratio and lipid properties

In recent years the study of extracellular vesicles has gathered much scientific and clinical interest. As the field is expanding, it is becoming clear that better methods for characterization and quantification of extracellular vesicles as well as better standards to compare studies are warranted. The goal of the present work was to find improved parameters to characterize extracellular vesicle preparations. Here we introduce a simple 96 well plate-based total lipid assay for determination of lipid content and protein to lipid ratios of extracellular vesicle preparations from various myeloid and lymphoid cell lines as well as blood plasma. These preparations included apoptotic bodies, microvesicles/microparticles, and exosomes isolated by size-based fractionation. We also investigated lipid bilayer order of extracellular vesicle subpopulations using Di-4-ANEPPDHQ lipid probe, and lipid composition using affinity reagents to clustered cholesterol (monoclonal anti-cholesterol antibody) and ganglioside GM1 (cholera toxin subunit B). We have consistently found different protein to lipid ratios characteristic for the investigated extracellular vesicle subpopulations which were substantially altered in the case of vesicular damage or protein contamination. Spectral ratiometric imaging and flow cytometric analysis also revealed marked differences between the various vesicle populations in their lipid order and their clustered membrane cholesterol and GM1 content. Our study introduces for the first time a simple and readily available lipid assay to complement the widely used protein assays in order to better characterize extracellular vesicle preparations. Besides differentiating extracellular vesicle subpopulations, the novel parameters introduced in this work (protein to lipid ratio, lipid bilayer order, and lipid composition), may prove useful for quality control of extracellular vesicle related basic and clinical studies.

Differential detergent sensitivity of extracellular vesicle subpopulations

This work shows for the first time that exosomes are more resistant to detergents than microvesicles and apoptotic bodies.

Improved circulating microparticle analysis in acid-citrate dextrose (ACD) anticoagulant tube

INTRODUCTION

Recently extracellular vesicles (exosomes, microparticles also referred to as microvesicles and apoptotic bodies) have attracted substantial interest as potential biomarkers and therapeutic vehicles. However, analysis of microparticles in biological fluids is confounded by many factors such as the activation of cells in the blood collection tube that leads to in vitro vesiculation. In this study we aimed at identifying an anticoagulant that prevents in vitro vesiculation in blood plasma samples.

MATERIALS AND METHODS

We compared the levels of platelet microparticles and non-platelet-derived microparticles in platelet-free plasma samples of healthy donors. Platelet-free plasma samples were isolated using different anticoagulant tubes, and were analyzed by flow cytometry and Zymuphen assay. The extent of in vitro vesiculation was compared in citrate and acid-citrate-dextrose (ACD) tubes.

RESULTS

Agitation and storage of blood samples at 37 °C for 1 hour induced a strong release of both platelet microparticles and non-platelet-derived microparticles. Strikingly, in vitro vesiculation related to blood sample handling and storage was prevented in samples in ACD tubes. Importantly, microparticle levels elevated in vivo remained detectable in ACD tubes.

CONCLUSIONS

We propose the general use of the ACD tube instead of other conventional anticoagulant tubes for the assessment of plasma microparticles since it gives a more realistic picture of the in vivo levels of circulating microparticles and does not interfere with downstream protein or RNA analyses.