Plasma cells release membrane microparticles in a mouse model of multiple myeloma

The emerging role of extracellular vesicles in the diagnosis and treatment of autism spectrum disorders

Autism spectrum disorders (ASD) are neurodevelopmental conditions characterized by restricted, repetitive behavioral patterns and deficits in social interactions. The prevalence of ASD has continued to rise in recent years. However, the etiology and pathophysiology of ASD remain largely unknown. Currently, the diagnosis of ASD relies on behavior measures, and there is a lack of reliable and objective biomarkers. In addition, there are still no effective pharmacologic therapies for the core symptoms of ASD. Extracellular vesicles (EVs) are lipid bilayer nanovesicles secreted by almost all types of cells. EVs play a vital role in cell-cell communications and are known to bear various biological functions. Emerging evidence demonstrated that EVs are involved in many physiological and pathological processes throughout the body and the content in EVs can reflect the status of the originating cells. EVs have demonstrated the potential of broad applications for the diagnosis and treatment of various brain diseases, suggesting that EVs may have also played a role in the pathological process of ASD. Besides, EVs can be utilized as therapeutic agents for their endogenous substances and biological functions. Additionally, EVs can serve as drug delivery tools as nano-sized vesicles with inherent targeting ability. Here, we discuss the potential of EVs to be considered as promising diagnostic biomarkers and their potential therapeutic applications for ASD.

Circulating biosignatures in multiple myeloma and their role in multidrug resistance

A major obstacle to chemotherapeutic success in cancer treatment is the development of drug resistance. This occurs when a tumour fails to reduce in size after treatment or when there is clinical relapse after an initial positive response to treatment. A unique and serious type of resistance is multidrug resistance (MDR). MDR causes the simultaneous cross resistance to unrelated drugs used in chemotherapy. MDR can be acquired through genetic alterations following drug exposure, or as discovered by us, through alternative pathways mediated by the transfer of functional MDR proteins and nucleic acids by extracellular vesicles (M Bebawy V Combes E Lee R Jaiswal J Gong A Bonhoure GE Grau, 23 9 1643 1649, 2009).Multiple myeloma is an incurable cancer of bone marrow plasma cells. Treatment involves high dose combination chemotherapy and patient response is unpredictable and variable due to the presence of multisite clonal tumour infiltrates. This clonal heterogeneity can contribute to the development of MDR. There is currently no approved clinical test for the minimally invasive testing of MDR in myeloma.Extracellular vesicles comprise a group of heterogeneous cell-derived membranous structures which include; exosomes, microparticles (microvesicles), migrasomes and apoptotic bodies. Extracellular vesicles serve an important role in cellular communication through the intercellular transfer of cellular protein, nucleic acid and lipid cargo. Of these, microparticles (MPs) originate from the cell plasma membrane and vary in size from 0.1-1um. We have previously shown that MPs confer MDR through the transfer of resistance proteins and nucleic acids. A test for the early detection of MDR would benefit clinical decision making, improve survival and support rational drug use. This review focuses on microparticles as novel clinical biomarkers for the detection of MDR in Myeloma and discusses their role in the therapeutic management of the disease.

B Cell-Derived Extracellular Vesicles Reveal Residual B Cell Activity in Kidney Graft Recipients Undergoing Pre-Transplant Desensitization

Background: Living-donor kidney transplant (LDKT) recipients undergoing desensitization for Human Leukocyte Antigen (HLA)-incompatibility have a high risk of developing antibody-mediated rejection (ABMR). The purpose of the study is to evaluate if residual B cell activity after desensitization could be estimated by the presence of circulating B cell-derived extracellular vesicles (BEVs).

Methods: BEVs were isolated by Sepharose-based size exclusion chromatography and defined as CD19+ and HLA-II+ extracellular vesicles. We analyzed stored serum samples from positive crossmatch LDKT recipients before and after desensitization at first post-transplant biopsy and at 12-month protocol biopsy (n = 11). Control groups were formed by hypersensitized patients who were not submitted to desensitization (n = 10) and by low-risk recipients (n = 9). A prospective validation cohort of 11 patients also included the analysis of B cells subpopulations in recipients' blood and lymph nodes recovered upon graft implantation, along with BEVs analysis before and after desensitization.

Results: We found out that CD19+ and HLA-II+BEVs dropped significantly after desensitization and relapse in patients who later developed ABMR was evident. We validated these findings in a proof-of-concept prospective cohort of 6 patients who received the same desensitization protocol and also in a control group of 5 LDKT recipients. In these patients, B cell subpopulations were also studied in recipients' blood and lymph nodes that were recovered before the graft implantation. We confirmed the significant drop in BEVs after desensitization and that this paralleled the reduction in CD19+cells in lymph nodes, while in peripheral blood B cells, this change was almost undetectable.

Conclusions: BEVs reflected B cell residual activity after desensitization and this could be a valid surrogate of humoral alloreactivity in this setting.

Microparticles and PD1 interplay added a prognostic impact in treatment outcomes of patients with multiple myeloma

Although multiple myeloma (MM) is still considered as an incurable disease by current standards, the development of several combination therapies, and immunotherapy approaches has raised the hope towards transforming MM into an indolent, chronic disease, and possibly achieving a cure. We tried to shed light on the expression of PD1 and different Microparticles (MPs) in MM and their interplay as a mechanism of resistance to standardized treatments, in addition, find their associations with prognostic factors of symptomatic MM. Thirty patients with newly diagnosed and chemotherapy naïve active MM, along with 19 healthy participants of comparable age and sex were recruited, after diagnosis of MM; blood samples were collected from both patients and controls for flow cytometric detection of CD4+, CD8+, CD4+PD1+, and CD8+PD1+T cells, total MPs, CD138+ MPs, and platelet MPs. MM patients had statistically significant higher levels of TMPs, CD138+ MPs compared to their controls, while PMPs exhibited no significant difference between both groups. Statistically significant higher percentages of CD8+, PD1CD8+, PD1CD4+T cells were detected in patients compared to controls, while the latter group had a significantly higher percentage of CD4+T cells than MM patients, patients who did not achieve complete response, had significantly higher percentages of PMPs, CD138+MPs, PD1+CD8+, PD1+CD4+, and CD8+T cells (cutoff values = 61, 10.6, 13.5, 11.3 and 20.1 respectively), (p-values = 0.002, 0.003, 0.017, 0.001 and 0.008 respectively). Microparticles and PD1 expressions were associated with proliferative potential and resistance to Bortezomib-based treatments, our results suggested that they played a crucial role in myeloma progression.

Extracellular vesicles (EVs): What we know of the mesmerizing roles of these tiny vesicles in hematological malignancies?

Cancer is a complex disease in which a bidirectional collaboration between malignant cells and surrounding microenvironment creates an appropriate platform which ultimately facilitates the progression of the disease. The discovery of extracellular vesicles (EVs) was a turning point in the modern era of cancer biology, as their importance in human malignancies has set the stage to widen research interest in the field of cell-to-cell communication. The implication in short- and long-distance interaction via horizontally transfer of cellular components, ranging from non-coding RNAs to functional proteins, as well as stimulating target cells receptors by the means of ligands anchored on their membrane endows these "tiny vesicles with giant impacts" with incredible potential to re-educate normal tissues, and thus, to re-shape the surrounding niche. In this review, we highlight the pathogenic roles of EVs in human cancers, with an extensive focus on the recent advances in hematological malignancies.

Engineering Extracellular Vesicles for Cancer Therapy

Extracellular vesicles (EVs) are lipid bilayer containing nanovesicles that have a predominant role in intercellular communication and cargo delivery. EVs have recently been used as a means for drug delivery and have been depicted to elicit no or minimal immune response in vivo. The stability, biocompatibility and manipulatable tumour homing capabilities of these biological vessels make them an attractive target for the packaging and delivery of drugs and molecules to treat various diseases including cancer. The following chapter will summarise current EV engineering techniques for the purpose of delivering putative drugs and therapeutic molecules for the treatment of cancer. The relevance of EV source will be discussed, as well as the specific modifications required to manufacture them into suitable vehicles for molecular drug delivery. Furthermore, methods of EV cargo encapsulation will be evaluated with emphasis on intercellular coordination to allow for the effective emptying of therapeutic contents into target cells. While EVs possess properties making them naturally suitable nanocarriers for drugs and molecules, many challenges with clinical translation of EV-based platforms remain. These issues need to be addressed in order to harness the true potential of the EV-based therapeutic avenue.

The Role of Exosomes in Stemness and Neurodegenerative Diseases-Chemoresistant-Cancer Therapeutics and Phytochemicals

Exosomes exhibit a wide range of biological properties and functions in the living organisms. They are nanometric vehicles and used for delivering drugs, as they are biocompatible and minimally immunogenic. Exosomal secretions derived from cancer cells contribute to metastasis, immortality, angiogenesis, tissue invasion, stemness and chemo/radio-resistance. Exosome-derived microRNAs (miRNAs) and long non-coding RNAs (lnc RNAs) are involved in the pathophysiology of cancers and neurodegenerative diseases. For instance, exosomes derived from mesenchymal stromal cells, astrocytes, macrophages, and acute myeloid leukemia (AML) cells are involved in the cancer progression and stemness as they induce chemotherapeutic drug resistance in several cancer cells. This review covered the recent research advances in understanding the role of exosomes in cancer progression, metastasis, angiogenesis, stemness and drug resistance by illustrating the modulatory effects of exosomal cargo (ex. miRNA, lncRNAs, etc.) on cell signaling pathways involved in cancer progression and cancer stem cell growth and development. Recent reports have implicated exosomes even in the treatment of several cancers. For instance, exosomes-loaded with novel anti-cancer drugs such as phytochemicals, tumor-targeting proteins, anticancer peptides, nucleic acids are known to interfere with drug resistance pathways in several cancer cell lines. In addition, this review depicted the need to develop exosome-based novel diagnostic biomarkers for early detection of cancers and neurodegenerative disease. Furthermore, the role of exosomes in stroke and oxidative stress-mediated neurodegenerative diseases including Alzheimer’s disease (AD), and Parkinson’s disease (PD) is also discussed in this article.

Extracellular Vesicles: Mechanisms in Human Health and Disease

SIGNIFICANCE

Secreted extracellular vesicles (EVs) are now considered veritable entities for diagnosis, prognosis, and therapeutics. These structures are able to interact with target cells and modify their phenotype and function. Recent Advances: Since composition of EVs depends on the cell type of origin and the stimulation that leads to their release, the analysis of EV content remains an important input to understand the potential effects of EVs on target cells.

CRITICAL ISSUES

Here, we review recent data related to the mechanisms involved in the formation of EVs and the methods allowing specific EV isolation and identification. Also, we analyze the potential use of EVs as biomarkers in different pathologies such as diabetes, obesity, atherosclerosis, neurodegenerative diseases, and cancer. Besides, their role in these diseases is discussed. Finally, we consider EVs enriched in microRNA or drugs as potential therapeutic cargo able to deliver desirable information to target cells/tissues.

FUTURE DIRECTIONS

We underline the importance of the homogenization of the parameters of isolation of EVs and their characterization, which allow considering EVs as excellent biomarkers for diagnosis and prognosis.

A Challenge to Aging Society by microRNA in Extracellular Vesicles: microRNA in Extracellular Vesicles as Promising Biomarkers and Novel Therapeutic Targets in Multiple Myeloma

Multiple myeloma (MM) is a malignancy of terminally differentiated plasma cells and is the second most common hematological cancer. MM frequently occurs in the elderly population with the median age as the middle sixties. Over the last 10 years, the prognosis of MM has been dramatically improved by new therapeutic drugs; however, MM is still incurable. The pathogenesis of MM is still unclear, thus greater understanding of the molecular mechanisms of MM malignancy is desirable. Recently, microRNAs (miRNAs) were shown to modulate the expression of genes critical for MM pathogenesis. In addition, miRNAs are secreted via extracellular vesicles (EVs), which are released from various cell types including MM cells, and these miRNAs are involved in multiple types of cell-cell interactions, which lead to the malignancy of MM. In this review, we summarize the current knowledge regarding the role of miRNA secretion via EVs and of EVs themselves in MM development. We also discuss the potential clinical applications of EVs as promising biomarkers and new therapeutic targets for improving the outcome of MM, resulting in a brighter future for aging societies.

Extracellular vesicle cross-talk in the bone marrow microenvironment: implications in multiple myeloma

The bone marrow (BM) represents a complex microenvironment containing stromal cells, immune cells, osteoclasts, osteoblasts, and hematopoietic cells, which are crucial for the immune response, bone formation, and hematopoiesis. Apart from soluble factors and direct cell-cell contact, extracellular vesicles (EVs), including exosomes, were recently identified as a third mediator for cell communication. Solid evidence has already demonstrated the involvement of various BM-derived cells and soluble factors in the regulation of multiple biological processes whereas the EV-mediated message delivery system from the BM has just been explored in recent decades. These EVs not only perform physiological functions but can also play a role in cancer development, including in Multiple Myeloma (MM) which is a plasma cell malignancy predominantly localized in the BM. This review will therefore focus on the multiple functions of EVs derived from BM cells, the manipulation of the BM by cancer-derived EVs, and the role of BM EVs in MM progression.

Evaluation of thrombosis-related biomarkers before and after therapy in patients with multiple myeloma

Background

Thrombosis is one of the complications in the clinical course of multiple myeloma (MM). Vascular endothelial cells and/or the hemostatic-coagulatory system are thought to play an important role in thrombosis of MM. In addition to melphalan-prednisone (Mel-P) therapy, several new therapeutic drugs such as lenalidomide or bortezomib have been developed and show effectiveness against MM. However, these new drugs also have risk of therapy-related thrombosis.

Methods

We assessed 103 MM patients and 30 healthy controls, using enzyme-linked immunosorbent assays to evaluate five biomarkers: platelet-derived microparticles (PDMP), plasminogen activator inhibitor-1 (PAI-1), high mobility group box protein-1 (HMGB1), endothelial protein C receptor (EPCR), and soluble vascular cell adhesion molecule-1 (sVCAM-1). The effects of Mel-P, bortezomib, and lenalidomide on the plasma concentrations of these biomarkers were investigated.

Results

The plasma concentrations of PDMP, PAI-1, HMGB1, EPCR, and sVCAM-1 were higher in MM patients than in healthy controls. Mel-P, bortezomib, and lenalidomide therapies all reduced biomarker levels after treatment. However, when only patients with higher levels of EPCR were compared, differences were seen between the three therapies in the elevation of PDMP, HMGB1, and PAI-1.

Conclusion

These results suggest that both MM and therapies for MM can induce a hypercoagulable state. The elevated risk of thrombosis conferred by hypercoagulability increases patient morbidity and mortality. Attention should be paid to therapy-related thrombosis when new therapeutic regimens are selected for MM patients.

Microvesicles in vascular homeostasis and diseases. Position Paper of the European Society of Cardiology (ESC) Working Group on Atherosclerosis and Vascular Biology

Microvesicles are members of the family of extracellular vesicles shed from the plasma membrane of activated or apoptotic cells. Microvesicles were initially characterised by their pro-coagulant activity and described as "microparticles". There is mounting evidence revealing a role for microvesicles in intercellular communication, with particular relevance to hemostasis and vascular biology. Coupled with this, the potential of microvesicles as meaningful biomarkers is under intense investigation. This Position Paper will summarise the current knowledge on the mechanisms of formation and composition of microvesicles of endothelial, platelet, red blood cell and leukocyte origin. This paper will also review and discuss the different methods used for their analysis and quantification, will underline the potential biological roles of these vesicles with respect to vascular homeostasis and thrombosis and define important themes for future research.

Extracellular Vesicles as a Source of Urological Biomarkers: Lessons Learned From Advances and Challenges in Clinical Applications to Major Diseases

Extracellular vesicles (EVs) not only eliminate unwanted molecular components, but also carry molecular cargo essential for specific intercellular communication mechanisms. As the molecular characteristics and biogenetical mechanisms of heterogeneous EVs are different, many studies have attempted to purify and characterize EVs. In particular, exosomal molecules, including proteins, lipids, and nucleic acids, have been suggested as disease biomarkers or therapeutic targets in various diseases. However, several unresolved issues and challenges remain despite these promising results, including source variability before the isolation of exosomes from body fluids, the contamination of proteins during isolation, and methodological issues related to the purification of exosomes. This paper reviews the general characteristics of EVs, particularly microvesicles and exosomes, along with their physiological roles and contribution to the pathogenesis of major diseases, several widely used methods to isolate exosomes, and challenges in the development of disease biomarkers using the molecular contents of EVs isolated from body fluids.

Extracellular vesicles and blood diseases

Extracellular vesicles (EVs) are small membrane vesicles released from many different cell types by the exocytic budding of the plasma membrane in response to cellular activation or apoptosis. EVs disseminate various bioactive effectors originating from the parent cells and transfer functional RNA and protein between cells, enabling them to alter vascular function and induce biological responses involved in vascular homeostasis. Although most EVs in human blood originate from platelets, EVs are also released from leukocytes, erythrocytes, endothelial cells, smooth muscle cells, and cancer cells. EVs were initially thought to be small particles with procoagulant activity; however, they can also evoke cellular responses in the immediate microenvironments and transport microRNAs (miRNA) into target cells. In this review, we summarize the recent literature relevant to EVs, including a growing list of clinical disorders that are associated with elevated EV levels. These studies suggest that EVs play roles in various blood diseases.

Exosome-Based Cancer Therapy: Implication for Targeting Cancer Stem Cells

Drug resistance, difficulty in specific targeting and self-renewal properties of cancer stem cells (CSCs) all contribute to cancer treatment failure and relapse. CSCs have been suggested as both the seeds of the primary cancer, and the roots of chemo- and radio-therapy resistance. The ability to precisely deliver drugs to target CSCs is an urgent need for cancer therapy, with nanotechnology-based drug delivery system being one of the most promising tools to achieve this in the clinic. Exosomes are cell-derived natural nanometric vesicles that are widely distributed in body fluids and involved in multiple disease processes, including tumorigenesis. Exosome-based nanometric vehicles have a number of advantages: they are non-toxic, non-immunogenic, and can be engineered to have robust delivery capacity and targeting specificity. This enables exosomes as a powerful nanocarrier to deliver anti-cancer drugs and genes for CSC targeting therapy. Here, we will introduce the current explorations of exosome-based delivery system in cancer therapy, with particular focus on several exosomal engineering approaches that have improved their efficiency and specificity for CSC targeting.

Isolation of Human CD138(+) Microparticles from the Plasma of Patients with Multiple Myeloma

The confinement of multiple myeloma (MM) to the bone marrow microenvironment requires an invasive bone marrow biopsy to monitor the malignant compartment. The existing clinical tools used to determine treatment response and tumor relapse are limited in sensitivity mainly because they indirectly measure tumor burden inside the bone marrow and fail to capture the patchy, multisite tumor infiltrates associated with MM. Microparticles (MPs) are 0.1- to 1.0-μm membrane vesicles, which contain the cellular content of their originating cell. MPs are functional mediators and convey prothrombotic, promalignant, proresistance, and proinflammatory messages, establishing intercellular cross talk and bypassing the need for direct cell-cell contact in many pathologies. In this study, we analyzed plasma cell–derived MPs (CD138⁺) from deidentified MM patients (n = 64) and normal subjects (n = 18) using flow cytometry. The morphology and size of the MPs were further analyzed using scanning electron microscopy. Our study shows the proof of a systemic signature of MPs in MM patients. We observed that the levels of MPs were significantly elevated in MM corresponding to the tumor burden. We provide the first evidence for the presence of MPs in the peripheral blood of MM patients with potential applications in personalized MM clinical monitoring.

Multiple myeloma exosomes establish a favourable bone marrow microenvironment with enhanced angiogenesis and immunosuppression

Multiple myeloma (MM) pathogenesis and progression largely rely on the cells and extracellular factors in the bone marrow (BM) microenvironment. Compelling studies have identified tumour exosomes as key regulators in the maintenance and education of the BM microenvironment by targeting stromal cells, immune cells, and vascular cells. However, the role of MM exosomes in the modification of the BM microenvironment and MM progression remains unclear. Here, we explored the functions of MM exosomes in angiogenesis and immunosuppression in vitro and in vivo. Murine MM exosomes carrying multiple angiogenesis-related proteins enhanced angiogenesis and directly promoted endothelial cell growth. Several pathways such as signal transducer and activator of transcription 3 (STAT3), c-Jun N-terminal kinase, and p53 were modulated by the exosomes in endothelial and BM stromal cells. These exosomes promoted the growth of myeloid-derived suppressor cells (MDSCs) in naive mice through activation of the STAT3 pathway and changed their subsets to similar phenotypes to those seen in MM-bearing mice. Moreover, MM exosomes up-regulated inducible nitric oxide synthase and enhanced the immunosuppressive capacity of BM MDSCs in vivo. Our data show that MM exosomes modulate the BM microenvironment through enhancement of angiogenesis and immunosuppression, which will further facilitate MM progression. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

The use of animal models in multiple myeloma

In myeloma, the understanding of the tissular, cellular and molecular mechanisms of the interactions between tumor plasma cells and bone cells have progressed from in vitro and in vivo studies. However none of the known animal models of myeloma reproduce exactly the human form of the disease. There are currently three types of animal models: (1) injection of pristane oil in BALB/c mice leads to intraperitoneal plasmacytomas but without bone marrow colonization and osteolysis; (2) injection of malignant plasma cell lines in immunodeficient mice SCID or NOD/SCID; the use of the SCID-hu or SCID-rab model allows the use of fresh plasma cells obtained from MM patients; (3) injection of allogeneic malignant plasma cells (5T2MM, 5T33) in the C57BL/KalwRij mouse induces bone marrow proliferation and osteolytic lesions. These cells did not grow in vitro and can be propagated by injection of plasma cells isolated from bone marrow of a mouse at end stage of the disease into young recipient mice. The 5TGM1 is a subclone of 5T33MM cells and can grow in vitro. Among the different models, the 5TMM models and SCID-hu/SCID-rab models were extensively used to test pathophysiological hypotheses and to assess anti-osteoclastic, anti-osteoblastic or anti-tumor therapies in myeloma. In the present review, we report the different types of animal models of MM and describe their interests and limitations.

Extracellular vesicles in hematological disorders

Extracellular vesicles (EVs), comprised of exosomes, microparticles, apoptotic bodies, and other microvesicles, are shed from a variety of cells upon cell activation or apoptosis. EVs promote clot formation, mediate pro-inflammatory processes, transfer proteins and miRNA to cells, and induce cell signaling that regulates cell differentiation, proliferation, migration, invasion, and apoptosis. This paper will review the contribution of EVs in hematological disorders, including hemoglobinopathies (sickle cell disease, thalassemia), paroxysmal nocturnal hemoglobinuria, and hematological malignancies (lymphomas, myelomas, and acute and chronic leukemias).