Extracellular vesicle interactions with the external and internal exposome in mediating carcinogenesis

The influence of environmental factors on an individual, from conception onwards, is defined as the exposome. It can be categorized into the external exposome, which includes external factors such as air pollution, chemical contaminants, and diet, and the internal exposome, which is unique to an individual, and involves age, physiology, and their genetic profile. The effect of external exposures on the internal exposome, or genetic profile, can be determined through omics analyses. However, this is often compromised due to low sample quantity and cost. Therefore, identification of other factors that can provide an insight into the cellular profile of an individual, provides an exciting avenue, and an emerging field is that of extracellular vesicles (EVs). Recently, our understanding of how cells can communicate with each other has shifted to recognise the role of EVs. EVs are secreted by all living cells, and have been identified in all biological fluids studied so far. They transport bioactive molecules (e.g., proteins, miRNAs, and DNA), and their release can be regulated by the cellular microenvironment. Analysis of EVs in respond to environmental factors might provide novel insights into the role of tumour EVs in carcinogenesis. Not only will EVs give some insight into the tumour cells themselves but they will also provide a better understanding of how cells communicate with one another, contributing to cancer progression. Moreover, characterising the content and functions of tumour-derived EVs has the potential to overcome the current challenges to improve cancer patient outcomes. For example, the identification of EVs targets for therapeutic interventions and tumour EVs biomarkers could facilitate the development of early screening for several cancers. The aim of this review, thus, is to discuss the overall role of EVs in response to the various external and internal signals in cancer. We will specifically highlight the biogenesis, secretion, and content of EVs in response to oncogenic transformation and metabolic regulators in cancer

Circulating microparticles as biomarkers of stroke: A focus on the value of endothelial- and platelet-derived microparticles.

Stroke is one of the leading causes of mortality and disability worldwide. Numerous pathophysiological mechanisms involving blood vessels, coagulation and inflammation contribute to the vascular occlusion. Perturbations in these pathways can be detected by numerous methods including changes in endoplasmic membrane remodeling and rearrangement leading to the shedding of microparticles (MPs) from various cellular origins in the blood. MPs are small membrane-derived vesicles that are shed from nearly all cells in the body in resting state or upon stimulation. MPs act as biological messengers to transfer information to adjacent and distant cells thus regulating various biological processes. MPs may be important biomarkers and tools for the identification of the risk and diagnosis of cerebrovascular diseases. Endothelial activation and dysfunction and altered thrombotic responses are two of the main features predisposing to stroke. Endothelial MPs (EMPs) have been recognized as both biomarkers and effectors of endothelial cell activation and injury while platelet-derived MPs (PMPs) carry a strong procoagulant potential and are activated in thrombotic states. Therefore, we reviewed here the role of EMPs and PMPs as biomarkers of stroke. Most studies reported high circulating levels of EMPs and PMPs in addition to other cell origins in stroke patients and have been linked to stroke severity, the size of infarction, and prognosis. The identification and quantification of EMPs and PMPs may thus be useful for the diagnosis and management of stroke.NPRP award (NPRP8-1750-3-360) from Qatar National Research Fund (a member of Qatar Foundation) and a Qatar University high collaborative grant (QUCG-CPH-2018\2019-2

Part One: Extracellular Vesicles as Valuable Players in Diabetic Cardiovascular Diseases

Extracellular vesicles (EVs) are particles released in the extracellular space from all cell types in physiological and pathological conditions and emerge as a new way of cell-cell communication by transferring their biological contents into target cells. The levels and composition of circulating EVs differ from a normal condition to a pathological one, making them real circulating biomarkers. EVs have a very complex contribution in both health and disease, most likely in relationship between diabetes and cardiovascular disease. The involvement of EVs to the development of cardiovascular complications in diabetes remains an open discussion for therapists. Circulating EVs may offer a continuous access path to circulating information on the disease state and a new perspective in finding a correct diagnosis, in estimating a prognosis and also in applying an effective therapy. Besides their role as biomarkers and targets for therapy, EVs can be exploited as biological tools in influencing the different processes affected in diabetic cardiovascular diseases. This chapter will summarize the current knowledge about EVs as biological vectors modulating diabetic cardiovascular diseases, including atherosclerosis, coronary artery disease, and peripheral arterial disease. Finally, we will point out EVs’ considerable value as clinical biomarkers, therapeutic targets, and potential biomedical tools for the discovery of effective therapy in diabetic cardiovascular diseases

Extracellular vesicles and their current role in cancer immunotherapy

Extracellular vesicles (EVs) are natural particles formed by the lipid bilayer and released from almost all cell types to the extracellular environment both under physiological conditions and in presence of a disease. EVs are involved in many biological processes including intercellular communication, acting as natural carriers in the transfer of various biomolecules such as DNA, various RNA types, proteins and different phospholipids. Thanks to their transfer and targeting abilities, they can be employed in drug and gene delivery and have been proposed for the treatment of different diseases, including cancer. Recently, the use of EVs as biological carriers has also been extended to cancer immunotherapy. This new technique of cancer treatment involves the use of EVs to transport molecules capable of triggering an immune response to damage cancer cells. Several studies have analyzed the possibility of using EVs in new cancer vaccines, which represent a particular form of immunotherapy. In the literature there are only few publications that systematically group and collectively discuss these studies. Therefore, the purpose of this review is to illustrate and give a partial reorganization to what has been produced in the literature so far. We provide basic notions on cancer immunotherapy and describe some clinical trials in which therapeutic cancer vaccines are tested. We thus focus attention on the potential of EV-based therapeutic vaccines in the treatment of cancer patients, overviewing the clinically relevant trials, completed or still in progress, which open up new perspectives in the fight against cancer

Exploring the key communicator role of exosomes in cancer microenvironment through proteomics

There have been many attempts to fully understand the mechanism of cancer behavior. Yet, how cancers develop and metastasize still remain elusive. Emerging concepts of cancer biology in recent years have focused on the communication of cancer with its microenvironment, since cancer cannot grow and live alone. Cancer needs to communicate with other cells for survival, and thus they secrete various messengers, including exosomes that contain many proteins, miRNAs, mRNAs, etc., for construction of the tumor microenvironment. Moreover, these intercellular communications between cancer and its microenvironment, including stromal cells or distant cells, can promote tumor growth, metastasis, and escape from immune surveillance. In this review, we summarized the role of proteins in the exosome as communicators between cancer and its microenvironment. Consequently, we present cancer specific exosome proteins and their unique roles in the interaction between cancer and its microenvironment. Clinically, these exosomes might provide useful biomarkers for cancer diagnosis and therapeutic tools for cancer treatment.This research was supported by the Bio & Medical Technology Development Program of the National Research Foundation (NRF) funded by the Ministry of Science and ICT (#2016M3A9B6026771 & #2014M3A9D5A01073598)

Characterization of Clever-1 expressing extracellular vesicles and their effect on T lymphocyte proliferation

Immune checkpoint inhibitors (ICIs) are the new milestone for the management of advanced solid cancers. Unfortunately, most patients are not responsive to these treatments, since they may develop mechanisms that suppress the quality and quantity of antitumor T-cell responses. The tumor microenvironment (TME) is a key cellular component of tumors. It includes immunomodulatory cells that display important roles in the resistance to ICIs. Among these cells, tumor-associated macrophages (TAMs) from the M2-like phenotype have been described to favor tumor growth and downregulate local and systemic immune responses. A subpopulation of these TAMs expresses Clever-1 (also known as Stabilin-1), which support the formation of an immunosuppressive TME and T-cell dysfunction. The depletion of Clever-1 both genetically and immunotherapeutically has been shown to activate the adaptive immune system and consequently, reduce tumor growth and metastasis. Recently, Clever-1 expression was detected in body fluids (plasma and lymph). However, how Clever-1 is secreted in the body and its functional consequences in T-cell function is poorly understood. Here, we identify by using differential centrifugation process of body fluids and immortalized monocytic conditioned medium that Clever-1 is expressed in both extracellular vesicles (EVs) and non-vesicular (NV) formats. Further, we show using in vitro assays that Clever-1+EVs functionally target T-cells affecting their proliferation status. Future studies are required to prove the process is dependent on Clever-1 and further investigate in the mechanistic routes involved in the inhibition mechanisms of Clever-1+EVs. In conclusion, this study describes the expression of suppressive proteins (e.g., Clever-1) in EV compartments with their inhibitory effects on T-cells in body fluids

The role and therapeutic potential of extracellular vesicles in atherosclerosis

Atherosclerosis, the pathophysiology of many cardiovascular diseases (CVD), is a chronic inflammatory process caused by the sustained accumulation of cholesterol, followed by endothelial dysfunction, and the resulting vascular inflammation. The established treatment for atherosclerosis, to date, involves the use of statins. These medications are hydroxymethylglutaryl coenzyme A reductase (HMG-CoA) inhibitors and lower the levels of by inhibiting HMG-CoA, a rate limiting step in the biosynthesis of cholesterol. Statin therapy varies in effectiveness based on dosage and individual differences, making effective treatment of patients challenging. More recently, extracellular vesicles (EVs) have emerged as a promising field in cardiovascular research. Once thought of as “platelet dust,” EVs are now recognized for their potential as therapeutic targets and tools. In this review, a comprehensive characterization of EVs is provided to explain how EVs are involved in normal physiological function and pathological processes of atherosclerosis. Evidence supports a model where EVs participate in the initiation and progression of atherosclerosis and may also be used as a delivery tool in disease therapy. Currently, cell-derived EVs can be therapeutic agents in animal models, an effective tool in gene therapy, or a drug delivery vehicle. Future experiments enhancing the therapeutic potential of EVs promise to deepen our understanding of EV-based therapy for atherosclerosis precision medicine

Elucidation of the signalling mechanisms involved in TF-mediated apoptosis in endothelial cells

Tissue factor (TF) is the main initiator of blood coagulation. In addition to its procoagulant property, TF has the ability to regulate various functions within cells including proliferation, angiogenesis and apoptosis. These outcomes appear to depend on the amount of TF with which the cell comes into contact with. In this study, human dermal blood endothelial cells (HDBEC) were transfected to express wild-type TF which is released following the activation of PAR2 in a normal physiological response. In addition, a model for the accumulation of TF in vascular disease and cancer was used by expressing a mutant form of TF (TFAla253-tGFP) which although expressed is not released by the cells and therefore it accumulates intracellularly. Initially, the phosphorylation of Src1 and Rac1 were monitored in order to determine any difference in phosphorylation patterns following PAR2 activation of cells. Phosphorylation of Src1, but not Rac1 was prolonged on expression of TF and was further enhanced on intracellular accumulation of TF. Therefore, the role of Src1 as a mediator of TF-induced apoptosis was examined next. Either inhibition of Src using pp60c-srcpeptide, or suppression of Src1 expression using siRNA prevented the TF-induced p38 MAPK activation and subsequent cellular apoptosis. Following confirmation of the role of Src1 in this process, an attempt was then made to delineate upstream intermediaries involved in this pathway. By using an inhibitory antibody (AIIB2), β1-integrin was shown to participate in TF-induced Src1 activation. In contrast, prevention of Src1-FAK complex formation using FAK inhibitor-14 did not interfere with the TF-mediated Src1 activation, despite a clear reduction in Src1 phosphorylation. Furthermore, TF-induced apoptosis did not appear to require Src1-FAK binding. In conclusion, this study has established further steps in the pathway by which TF can induce cellular apoptosis, and suggests a mechanism by which the increased amount of TF during inflammation can have detrimental outcome on the vascular system