Osmotic stress induces the formation of migrasome‐like vesicles

Migrasomes are extracellular vesicles that form on the retraction fibers of migrating cells. In this study, we report the formation of migrasome‐like vesicles enriched in tetraspanin 4 and containing cytoplasmic components in response to hypoosmotic stress. When migrating cells were subjected to hypoosmotic stress, vesicles with a size distribution of 0.5 to 2 μm formed on the retraction fibers, and vanished in a few minutes. The vesicles are rich in cholesterol, and their number was reduced when cells were pretreated with lipoprotein‐deficient serum. The formation of migrasome‐like vesicles upon hypoosmotic stress may provide biophysical cues regarding the cellular response to this external stimulus in cells and tissues.