Fold values for each spot (A1CA5) are presented for plasma (B6) and exosome-rich fraction (C6). This study has several limitations that should be mentioned. varies according to pathology, extracellular vesicles may prove a rich source of biomarkers. However, their biological and pathophysiological functions are poorly comprehended in hematological malignancies. Objective Here, we investigated proteome changes in the exosome-rich fraction of the plasma of myelodysplastic syndrome patients and healthy donors. Methods Exosome-rich fraction of the plasma was isolated using ExoQuick?: proteomes were compared and statistically processed; proteins were identified by nanoLC-MS/MS and verified using the ExoCarta and QuickGO databases. Mann-Whitney and Spearman analyses were used to statistically analyze the data. 2D western blot was used to monitor clusterin proteoforms. Results Statistical analyses of the data highlighted clusterin alterations as the most significant. 2D western blot showed that this clusterin changes were caused by posttranslational modifications. Moreover, there was a notable increase in the clusterin proteoform in the exosome-rich fraction of plasma of patients with more severe myelodysplastic syndrome; this corresponded with a simultaneous decrease in their plasma. Conclusions This specific clusterin proteoform seems to be a promising biomarker for myelodysplastic syndrome progression. Introduction Myelodysplastic syndrome (MDS) encompasses a diverse range of oncohematological diseases that affect hematopoietic stem cells and their microenvironment. It is characterized by ineffective hematopoiesis, blood cytopenias, and progression to acute myeloid leukemia. According to the WHO classification [1], which is based on Delavirdine mesylate cytogenetics and findings in the bone marrow and peripheral blood, MDS patients are divided into several subgroups. Refractory anemia (RA) and refractory anemia with ringed sideroblasts (RARS) are MDS subgroups characterized by dysplasia limited to erythroid lineage, by less than 5% of the blasts being located in the bone marrow, and by limited response to treatment. Another subgroup is usually refractory cytopenia with multilineage dysplasia (RCMD), which is usually defined by the presence of varying degrees of peripheral blood cytopenia and by dysplastic changes that are present in 10% or more of the cells in two or more myeloid lineages in the bone marrow (with less than 15% ringed sideroblasts). Refractory anemia with excess Delavirdine mesylate of blasts type one and two (RAEB-1, RAEB-2) are other subgroups; they Delavirdine mesylate are recognized on the basis of the number of these blasts in the bone marrow: RAEB-1 with 5C9% and RAEB-2 with 10C19% [2]. Extracellular vesicles (EVs) are small membrane vesicles released into body fluids from the majority of, if not all, cell types and cancer cells [3]. They are present in plasma, urine, breast milk, semen, amniotic fluid, ascites, saliva, interstitial fluid, and extracellular matrix [4C13]. EVs contain and EBR2A transport a wide range of cargo, including mRNA, miRNA, proteins (membrane and cytosolic), enzymes, transcription factors, molecular chaperones and signaling molecules. Differences in their cargo may reflect their function [14C18]. EV functions are thought to include intercellular communication [19, 20], immune surveillance [21], stem cell maintenance [22], tissue regeneration [23] and blood coagulation [24]. EV secretion is known to be dependent on pathology (e.g., cancer, inflammation, hematological disorders). For example, hypoxia or oxidative stress can trigger EV secretion [25]. While the involvement of EVs in hematological malignancies has been poorly investigated [18, 25], various cancer cell lines have been shown to secrete more EVs than normal cells. In B-cell chronic lymphocytic leukemia and in mouse multiple myeloma, the total EV level was significantly higher than in healthy subjects [26, 27]. More importantly, the EV cargo in cancer cells is distinct from that in healthy ones and is highly variable according to cell origin [28]. In recent years, MS-based proteomics has been used to identify vesicular proteins and have helped reveal the protein composition of EVs from various cell types and body fluids [29], including plasma [30, 31]. Several distinct features make EVs an attractive Delavirdine mesylate source for proteomic research. They are rich in low-abundance proteins that are underrepresented in unfractionated biological materials. They contain a specific set of proteins that can Delavirdine mesylate help determine the environment from which the EVs originated. Therefore, they could prove to be a rich source of biomarkers [18, 32]. The results of several proteomic studies have provided insight into how exosomes contribute to the pathobiology of hematological malignancies. For example, it was suggested that in multiple myeloma the proteins transferred by exosomes to malignant cells can promote tumor growth and spreading [33]. Proteins identified in exosomes derived from human lymphoma cells were associated with either antigen presentation and processing or cell migration, suggesting that exosomes play an important role in immunity regulation and the interaction between lymphoma cells and their microenvironment [34]. Paggetti values of all spots using one-way ANOVA analysis. For the purpose of protein identification, a 2D preparative.
