Cells intermediates of endocytosis willbe aimed for
Cells organize and process endocytosed proteins and lipids via endocytotic pathway tosustain its correct phenotype. The pathways for vesicle trafficking from cell surfacereceptors to endosomes, compartmentalizes of “early endosomes”, “late endosomes”(multivesicular bodies), “degratative lysosomes” or “vacuoles” (Hurley and Odorzzi2012). Whether multivesicular bodies (MVB-s), as the intermediates of endocytosis willbe aimed for degradation towards lysosomes/vacuoles, or fused with the limitingmembrane to a plasma membrane, and released its intraluminal content as exocytoticexosomes, will be either coordinated by the ubiquitination process in conjunction withESCRT (endosomal sorting complex required for transport) machinery, or ESCRT-independently, and depend on the sufficiency and localization of cholesterol in thecytoplasmic vesicles of MVB-s (Trajkovic et al., 2008; Möbius et al., 2003). In addition,exosome secretion is administrated by a number of small regulatory Ras-like GTPases,the Rab proteins that specifically control the vesicle movement and tethering betweendifferent endosomal compartments (Hutagalung and Novick et al., 2011).Extracellular vesicles: exosomes, shedding microvesicles and apoptotic bodies are agroup of intact and nano diametric lipid layered vesicles all released from cell interior toextracellular environment. Extracellular vesicles are evaluated by their differentphysical/morphological properties and sedimentation rates to have a better selection forthe desired subpopulations and prevent cross contaminations (Gould and Raposo, 2013).Exosomes, among other, are the smallest and most homogenous group of vesicles, with asize definition 30-100 nm that have been under investigation with particular interest.Exosomes display the same membrane orientation as plasma membranes and carryfunctional proteins, lipids and nucleic acids in them, to be found in every life form- fromplants to bacteria (Ostrowski et al., 2010). Because exosomes can transfer their contentinto another cells and modify recipient cell’s physiology – they are now solidly recognizedas in part of intercellular communication (Valadi et al., 2007) and above all, sinceexosomes have unique repertoire of proteins and RNA profile that is representative fortheir cellular origin and health condition, make them suitable for cancer diagnostics,potential vaccine carriers, immunotherapy and other aspects of medicine andbiotechnology.