Functions, pathophysiology and current insights of exosomal endocrinology (Review)

Studies on extracellular vesicles have increased in recent years. The multi‑dimensional nature of their roles in cellular homeostasis, cell‑to‑cell and tissue‑to‑tissue communication at the level of the organism, as well as their actions on the holobiome (intra‑/interspecies interaction), have garnered the interest of a large number of researchers. Exosomes are one of the most researched classes of extracellular vesicles because they are carriers of targeted protein and DNA/RNA loads. Their multi‑functional cargo have been indicated to regulate a vast number of biological pathways in target cells. However, the mechanisms governing these interactions have not yet been fully determined. Endocrinology, by definition, focuses on homeostatic, and cell‑to‑cell and tissue‑to‑tissue communication mechanisms. Therefore exosomes should be included in this research topic. Exosomes have previously been associated with a number of endocrine disorders, including obesity, type 2 diabetes mellitus, disorders of the reproductive system and cancer. Furthermore, their biogenesis, composition and function have been associated with viruses, an entirely different domain of life. The profound roles of exosomes in homeostasis, stress and several pathological conditions, in conjunction with their selective and cell‑specific composition/function, allude to their use as promising circulating clinical biomarkers of systemic stress and specific pathologic states, and as biocompatible vehicles of therapeutic cargo. The current review provides information on exosomes and discusses their endocrine implications.