Migrasomes

The mammalian cardiovascular system contains numerous migrating cells, mainly including fibroblasts, endothelial cells (ECs), vascular smooth muscle cells, and the resident immune cells. Cell migration of these above cells is one of the fundamental cellular mechanisms involved in maintaining cardiovascular homeostasis and contributed to the injuries repair of cardiovascular system. The newly discovered migration-dependent large vesicle-like structures, named migrasomes, which contain numerous smaller vesicles and other cellular components, have been shown to exist in ECs, neutrophils, and human blood serum. Migrasomes start to grow on the long membrane projections (also known as retraction fibers, RFs) hours after the initiation of RFs formation in migrating cells. The RFs serve as tethers stretched between the cell body and the substrate. The connections between the RFs and the cell will break as the cell migrates away, and the RFs disintegrate and the migrasomes detach from the cell. Then, migrasomes can be taken up by the surrounding cells, thus mediating the cell–cell communication; the free migrasomes can also rupture and release their luminal contents into the environment in a process named “migracytosis,” if the damaged mitochondria are discarded via migrasomes from the migrating cells, the process was named as “mitocytosis.” In this chapter, we will summarize the current understanding of the cellular composition and function of cardiovascular system, cardiovascular homeostasis and remodeling, the basic process of cell migration, the formation, characteristics, and tissue or cell distribution of migration-dependent migrasomes. Based on these above, we highlight the possible fundamental roles of migrasomes in cardiovascular homeostasis and injuries repair.