Discovery And Molecular Basis Of Migrasome

Cells communicate with each other in a variety of ways,such as secreting and releasing proteins and vesicles.Many types of cells can migrate.Here,we report the discovery of a cytosolic content releasing mechanism,named migracytosis,which indicates its dependence on the cell migration.During migracytosis,there are some tubular structures,called retraction fibers,behind the cell body.And some special vesicular structures,which we call “migrasomes”,containing variable numbers of small vesicles,grow on the intersections and the distal tips of retraction fibers.Eventually,these retraction fibers rapture and migrasomes are released into medium or taken up by another adjacent cell.Inhibition of migration results in the remarkable reduction in the number of these vesicles.Besides,the number of the vesicles markedly increases when cell migration is promoted.Thus,we conclude that the formation of these vesicles is migration-dependent.We also show that cytosolic contents can be transported into migrasomes and released from the cell through migrasomes.By being taken up by the surrounding cells,migrasomes may play important roles in cell-cell communication through providing not only biochemical information but also spatial information.In addition,our study demonstrate that there is a significant change in the calcium concentration in the migrasomes by cellular calcium imaging.It indicates that there is a high probability of signal transduction in the migrasome.Moreover,when bone marrow derived macrophages are stimulated with LPS,TNF? is enriched into the purified migrasomes from macrophages,suggesting that migrasomes have some functions in the inflammatory response.Finally,we develop a method for labeling migrasomes with a macromolecular dye,laying the foundation for rapid detection of migrasomes in different cells and tissues.