Extracellular vesicles are integral and functional components of the extracellular matrix

Abstract

Extracellular vesicles (EV) are small plasma membrane-derived particles released into the extracellular space by virtually all cell types. Recently, EV have received increased interest because of their capability to carry nucleic acids, proteins, lipids and signaling molecules and to transfer their cargo into the target cells. Less attention has been paid to their role in modifying the composition of the extracellular matrix (ECM), either directly or indirectly via regulating the ability of target cells to synthesize or degrade matrix molecules. Based on recent results, EV can be considered one of the structural and functional components of the ECM that participate in matrix organization, regulation of cells within it, and in determining the physical properties of soft connective tissues, bone, cartilage and dentin. This review addresses the relevance of EV as specific modulators of the ECM, such as during the assembly and disassembly of the molecular network, signaling through the ECM and formation of niches suitable for tissue regeneration, inflammation and tumor progression. Finally, we assess the potential of these aspects of EV biology to translational medicine.

Human placental villi contain stromal macrovesicles associated with networks of stellate cells

“…those in the exosome/small microvesicle size range) observed in the placenta appeared to be normally distributed and were larger than those reported in bone stromal tissue (Rilla et al. ). The fact that the small vesicles we observe in the villous stroma are larger than some reports in the literature may be because in three‐dimensional images the widest point can be identified, whereas two‐dimensional images may not intersect the widest point and so may under‐represent the true size of the vesicles.…”

“…In other tissues, stromal extracellular vesicles play important roles but these have volumes hundreds of times smaller than the villous stromal macrovesicles reported here (Rilla et al. ; Stik et al. ).…”

“…In bone, extracellular vesicles of different sizes (from 20 to 300 nm) and different types have been reported in association with particular tissues or roles (Rilla et al. ). Extracellular vesicles can be made in a number of different ways; exosomes (20–250 nm) are thought to be made inside the cell and secreted whereas microvesicles (100–1000 nm) are thought to be made by folding and pinching off of the plasma membrane (Tong & Chamley, ).…”

“…Other components of the extracellular matrix are stromal extracellular vesicles (Rilla et al 2017). These small membrane-bound vesicles have been observed in a number of different tissues and are thought to contain mediators that help regulate stromal remodelling and processes such as angiogenesis (Rilla et al 2017).…”

“…Other components of the extracellular matrix are stromal extracellular vesicles (Rilla et al 2017). These small membrane-bound vesicles have been observed in a number of different tissues and are thought to contain mediators that help regulate stromal remodelling and processes such as angiogenesis (Rilla et al 2017). In bone, extracellular vesicles of different sizes (from 20 to 300 nm) and different types have been reported in association with particular tissues or roles (Rilla et al 2017).…”