Exosomes in Extracellular Matrix Bone Biology
Purpose of Review
Exosomes are membrane vesicles that are released by most cell types into the extracellular environment. The purpose of this article is to discuss the main morphological features and contents of bone-derived exosomes, as well as their major isolation and physical characterization techniques. Furthermore, we present various scenarios and discuss potential clinical applications of bone-derived exosomes in bone repair and regeneration.
Exosomes were believed to be nanosized vesicles derived from the multivesicular body. Reports now suggest that nanovesicles could bud directly from the plasma membrane. However, the exosome cargo is cell-type specific and is derived from the parent cell. In the bone matrix, several intracellular proteins lacking a signal peptide are transported to the ECM by exosomes. Besides proteins, several mRNA, miRNA, and lipids are exported to the ECM by bone cells and bone marrow stromal cells. Recent evidence suggests that several of the functional components in the cargo could regulate processes of bone formation, inhibit osteoclast activity, and promote fracture repair.
Exosomes are powerful cellular molecular machines produced without human intervention and packaged with physiological cargo that could be utilized for molecular therapy in several skeletal disorders such as osteoporosis, osteogenesis imperfecta, and fracture healing. Although much work has been done, there is a lot of information that is still unknown, as exosomes contain a multitude of molecules whose identity and function have yet to be identified.
KeywordsExtracellular vesicles Exosomes Bone Matrix mineralization Tissue regeneration Osteoporosis
A. P greatly acknowledges the scholarship from the Rosztoczy Foundation.
This work was supported by the Brodie Endowment Fund and the National Institutes of Health grant DE11657.
Compliance with Ethical Standards
Conflict of Interest
Adrienn Pethő, Yinghua Chen, and Anne George declare no conflict of interest.
Human and Animal Rights and Informed Consent
This article does not contain any studies with human or animal subjects performed by any of the authors.
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