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Characteristics, Events, and Stages in Tumorigenesis
Published in Franklyn De Silva, Jane Alcorn, The Elusive Road Towards Effective Cancer Prevention and Treatment, 2023
Franklyn De Silva, Jane Alcorn
The selective packing of molecular cargo in EV-associated mechanisms remains poorly understood [768]. Exosomes (different from the exosome complex involved in RNA degradation [828, 894]), the smallest of the vesicles, are currently a hotspot in the field of cancer and are released by the fusion of multivesicular bodies [838, 839]. Exosomes were first discovered in the 1980s by Johnstone and colleagues and are nanoscale cystic vesicles actively secreted by many kinds of cells to function in the transmission of cell-to-cell information [846, 849, 851, 895]. They are capable of transporting proteins, peptides, metabolites, lipids, nucleic acids, and other components like CD80, MHC-I, and MHC-II that play a major part in intercellular communication including regulation of angiogenesis, fibrosis, and immune response [840, 881, 895].
The Emerging Role of Exosome Nanoparticles in Regenerative Medicine
Published in Harishkumar Madhyastha, Durgesh Nandini Chauhan, Nanopharmaceuticals in Regenerative Medicine, 2022
Zahra Sadat Hashemi, Mahlegha Ghavami, Saeed Khalili, Seyed Morteza Naghib
Exosomes are nanosized EVs (50–150 nm) originating from multivesicular bodies (MVBs). Various cells could release them into the extracellular environment through membrane fusion. These lipid bilayer nanovesicles are loaded with different cargos such as miRNA, DNA, RNA, lipids, and proteins. Exosomes are involved in different biological pathways such as intercellular communications, signal transferring, antigen presentation, and tumour progression. Their uptake occurs through endocytosis, direct fusion, or receptor–ligand interaction. Exosomes could be isolated and characterised by various methods such as Nanoparticle Tracking Analysis, Dynamic Light Scattering, Electron Microscopy, and Tunable Resistive Pulse Sensing (according to their size, density, surface charge, distinctive biomarkers, and membrane antigens).
Gastrointestinal Stromal Tumors: From Molecular Pathogenesis to Therapy
Published in Sherry X. Yang, Janet E. Dancey, Handbook of Therapeutic Biomarkers in Cancer, 2021
Joaquina Baranda, Stafinur Atay, Andrew K. Godwin
Exosomes originate from the fusion of endosomal multivesicular bodies (MVBs) [172], containing intraluminal vesicles (ILVs), with the plasma membrane and release of small bioactive vesicles via exocytosis into the interstitial space [173]. These vesicles are secreted by most cell types in vitro and in vivo. In addition, most cells of the immune system release exosomes, and includes B cells [174, 175] dendritic cells (DCs) [176], macrophages [177], T cells [178], and mast cells [179]. Furthermore, their presence in biological and physiological fluids, such as malignant ascites [180], bronchoalveolar lavage (BAL) fluid [181], serum [182], urine [183] and breast milk [184] has been well established. Even though the similar mechanisms lead to secretion of these vesicles, the molecular composition and function of these exosomes can vary in function of the cellular type that they derive from and the activation state of the parental cell [185, 186]. However, one invariant parameter is their density, morphology and size [186–188]. Exosome float on sucrose gradient to a density that ranges from 1.13 to 1.19 g/ml and display a circular shape with a diameter that varies from 30 to 100 nm [189].
A review on the current literature regarding the value of exosome miRNAs in various diseases
Published in Annals of Medicine, 2023
Senjie Li, Dongqing Lv, Hong Yang, Yan Lu, Yongping Jia
Exosomes have a double-membrane structure and are stimulated by normal or abnormal signals and engulfed by invagination of the plasma membrane to form primitive intracellular vesicles [3]. Many intracellular vesicles fuse and gradually mature into intraluminal vesicles (ILVs) [2,4]. ILVs contain many types of vesicular structures, and their mature bodies are called multivesicular bodies (MVBs). MVBs can be degraded and self-cleared through lysosomes and undergo apoptosis to ensure homeostasis. Additionally, undegraded MVBs secrete ILVs through exocytosis, distributing their contents to the whole body; once the ILVs exit the cell they become exosomes [5,6]. The content of the exosome is not necessarily the same as in the original secretion and can have different functions. MicroRNAs (miRNAs) can be sorted into exosomes by selectively binding to the protein heterogeneous nuclear ribonucleoprotein A2B1 and KRAS, indicating that secretion and release are complex processes, and the content will be processed and selected [7]. Exosomes enter the tissue after cell recognition and exert their effects through receptor interaction, fusion-absorption, endocytosis–exocytosis and other mechanisms [8] (Figure 1).
Extracellular vesicles in obesity and its associated inflammation
Published in International Reviews of Immunology, 2022
Vijay Kumar, Sonia Kiran, Santosh Kumar, Udai P. Singh
Cellular endosomes form by inward invagination of the plasma membrane, thereby incorporating some proteins normally found on the external cell surface into the endosomal membrane [46]. The contents of early endosomes can be degraded, recycled, or exported from the cell and materials to be recycled by the cell are sorted into recycling endosomes [47, 48]. The remainder of the early endosomes develops into late endosomes in which accumulate intraluminal vesicles (ILVs) containing lipids, nucleic acids, and proteins. Endosomes containing multiple vesicles are called multivesicular bodies (MVBs). If the contents are to be degraded, for example, polyubiquitinated proteins, the MLBs fuse with lysosomes [49]. For contents that are to be secreted, the MLBs fuse with the plasma membrane and release the ILVs as exosomes (EXOs) by budding, a process that depends on the intracellular concentration of Ca2+ [35].
Effects of Monobenzyl ether of hydroquinone on 3T3 mouse fibroblast viability and ultrastructure
Published in Ultrastructural Pathology, 2021
Aslı Erdoğan, Hasan Serdar Mutlu, Sibel Doğan, Tuğba Kotil
Under TEM, untreated cells exhibited characteristics of active cells with euchromatic nucleus, open nuclear pores, well developed rough endoplasmic reticulum (rER), abundant mitochondria, and prominent Golgi apparatus (Figure 3a,b). Vehicle group exhibited similar ultrastructural morphology with control group (Figure 3c,d). In 250 μM MBEH-treated group, there was a slight dilation in perinuclear space. In some mitochondria, swelling and loss of cristae were observed. There were dilation in rER cisternae. Multilamellar bodies, abundant lysosomes, and multivesicular bodies were seen in cytoplasm (Figure 3e,f). In 500 μM MBEH-treated group, cell membrane blebs and loss of cell volume were observed (Figure 3g,h). Nucleus and cytoplasm were more electron dense than other groups and organelles were not prominent. There were abundant multivesicular bodies and autophagic vacuoles in cytoplasm. In 750 μM MBEH-treated group, cells were completely degenerated (Figure 3i).