The Ultrastructure And Pathobiology Of Urinary Bladder Cancer
George T. Bryan, Samuel M. Cohen in The Pathology of Bladder Cancer, 2017
The Golgi apparatus of the mammalian urinary bladder consists of a complex membrane system (see Figure 5). Its degree of development and its location within the cell is different in the various cell layers.40,43 In basal cells, the Golgi complex is small and positioned laterally to the nucleus in the perinuclear cytoplasm. It consists of two to three curved parallel flattened vacuoles or cisternae that are often expanded at their ends. A few transport vesicles are associated with the concave inner surface of the stacks of cisternae. In the intermediate cell layer of normal urinary bladder epithelium, the Golgi complex is much larger and is often multicentric. Most of the Golgi fields are located in the perinuclear cytoplasm, facing the lumen of the bladder. Golgi complexes are more fully developed, as evidenced by increases in the lengths of the stacked lamellae. Transport vesicles are found along both the convex and the concave surfaces of the lamellae. In superficial cells, Golgi complexes may be located anywhere within the perinuclear cytoplasm, although a basal orientation is most common. Golgi complexes may occur singly or in several locations within the perinuclear cytoplasm. Transport vesicles are numerous in superficial cells.
The Identification of Cell Types in the Normal Adult Colon
Leonard H. Augenlicht in Cell and Molecular Biology of Colon Cancer, 2019
A variety of functional roles have been postulated for the apical vesicles in the surface columnar cells. In the mouse proximal colon two types of vesicles have been observed in these cells — a group of small highly electron dense vesicles averaging 120 to 180 μm and a second set of granules with a lower density averaging 210 to 260 μm in diameter.84 The authors postulate that the two types of vesicles are functionally related, perhaps comprising an intracellular buffering system. They also suggest that the vesicles originate within the cell, not as a result of endocytosis. The relative absence of apical pits and the inability to demonstrate endocytosis of luminal markers except on a very restricted scale85-87 tend to support this intracellular origin. Additional evidence is based on the autoradiographic demonstration of glycoprotein transport from the Golgi region to the cell surface via small vesicles.88 Thus, the apical vesicles may participate in the establishment and maintenance of the surface coat or glycocalyx. Finally, these vesicles may provide a mechanism of transport for secretory immunoglobulins to the cell surface, where they contribute to colonic defense mechanisms.89
Structure and Function of the Lower Urinary Tract
Anthony R. Mundy, John M. Fitzpatrick, David E. Neal, Nicholas J. R. George in The Scientific Basis of Urology, 2010
Vesicles are of two main types (28): small clear vesicles and larger vesicles with a dense core. The small clear vesicles are thought to contain so-called “fast” neurotransmitter substances, which are released directly into the area between the neuron and the adjacent neuron across a synapse, or the adjacent smooth muscle cell across a neuromuscular junction (Fig. 22) to open ligand-gated ion channels on the receptor site that will initiate an action potential— so-called “electromechanical coupling.” Outside the central nervous system, the commonest neurotransmitter to be found in these small clear vesicles is acetylcholine and the commonest receptor is the nicotinic acetylcholine receptor, although acetylcholine does not exclusively act as a fast neurotransmitter to open ligand-gated ion channels in this way, nor is the nicotinic receptor the only type of acetylcholine receptor (see below). In the central nervous system, γ-aminobutyric acid (GABA) is also found in small clear vesicles (28).
Tumor-derived exosomes: the next generation of promising cell-free vaccines in cancer immunotherapy
Published in OncoImmunology, 2020
Marzieh Naseri, Mahmood Bozorgmehr, Margot Zöller, Ehsan Ranaei Pirmardan, Zahra Madjd
In addition to constitutive exosome membrane and cytosolic molecules, exosomes contain a large variety of membrane proteins and soluble factors related to cell-type specific functions (e.g. integrins, selectins, Rab proteins, SNAREs, tetraspanins such as CD9, CD81, CD63, growth receptors), lipids (e.g. steroids, sphingolipids, glycerophospholipids), nucleic acids (mRNAs, miRNAs, sRNAs, DNAs), and others.40,45,50-54 According to the current version of Exocarta (http://www.exocarta.org), the largest exosome content database, 41,860 proteins, more than 7,540 RNA and 1,116 lipid molecules have been identified from more than 286 exosomal studies.55 These exosomal-shuttle molecules play key roles in exosome function. Exosomes can interact (by deliver or uptake) with their recipient cells via different mechanisms such as specific receptor binding, direct fusion with the plasma membrane, and phagocytosis.51 By their distribution throughout the body, these vesicles transfer information from host cells to target cells over long distances. Furthermore, due to the presence of exosomes in biofluids and origin-dependent content, which closely reflects various physiological and pathological conditions, they may also serve as an ideal noninvasive or minimally invasive tool for diagnosis and monitoring the efficacy of treatment regimes.
Exosome-carried microRNA-based signature as a cellular trigger for the evolution of chronic lymphocytic leukemia into Richter syndrome
Published in Critical Reviews in Clinical Laboratory Sciences, 2018
Ancuta Jurj, Laura Pop, Bobe Petrushev, Sergiu Pasca, Delia Dima, Ioana Frinc, Dalma Deak, Minodora Desmirean, Adrian Trifa, Bogdan Fetica, Grigore Gafencu, Sonia Selicean, Vlad Moisoiu, Wilhelm-Thomas Micu, Cristian Berce, Alexandra Sacu, Alin Moldovan, Andrei Colita, Horia Bumbea, Alina Tanase, Angela Dascalescu, Mihnea Zdrenghea, Rares Stiufiuc, Nicolae Leopold, Romulus Tetean, Emil Burzo, Ciprian Tomuleasa, Ioana Berindan-Neagoe
Recently, it has been shown that EVs released by cells are indicative of the cell type or its function. These micro-structures play an important role in cell-cell transfer and communication and are thought to have a key role in both physiological and pathological processes, being found in all the body fluids and binding only to selected targets [26,37,38]. There are various types of such vesicles, based on their different origins, biogenesis, and functions. Endosomes and lysosomes undergo a physiological process similar to exocytosis and fuse their membranes with the plasma membrane. This will lead to the expression of certain receptors on the surface of the vesicle that are also found in the endoplasmic reticulum [39–41]. Based on their size, the major vesicle populations may be exosomes, microvesicles, or apoptotic bodies [42–44]. EVs are depicted as a unique “messenger” used in cell-to-cell communication and to mediate the trafficking of various molecules that are traditionally regarded as either insoluble or cell-associated. Such molecules include various membranes, cytoplasm or nuclear proteins, as well as nucleic acids [45–47].
Unraveling the complexity of the extracellular vesicle landscape with advanced proteomics
Published in Expert Review of Proteomics, 2022
Julia Morales-Sanfrutos, Javier Munoz
Different types of extracellular vesicles have been identified and these are often classified on the basis of their size, composition and biological origin. Advances on this regard have been mainly driven by the development of new approaches for the isolation and characterization of EVs. However, the lack of defined guidelines and criteria for the unambiguous assignment of EVs, as well as issues with the purity and heterogeneity of EVs preparations, have caused a confusing nomenclature in current literature. Indeed, classification of the EVs landscape is continuously evolving [3]. One of the major types of EVs are microvesicles (MVs), sometimes referred as ectosomes and micro-particles. MVs are lipid-bilayered particles of 100–1000 nm that originate via shedding of the plasma membrane (Figure 1A). Their biogenesis is controlled by intracellular Ca2+ levels and a set of proteins that include flippases, translocases, scramblase, actin cytoskeleton and members of the Ras family of GTPase [4], ultimately leading to the outward budding of the plasma membrane, trapping inside the intra-cellular material.
Related Knowledge Centers
- Cell Biology
- Lipid Bilayer
- Liposome
- Cell Membrane
- Lysosome
- Cell
- Exocytosis
- Endocytosis
- Unilamellar Liposome
- Lamellar Phase