Effect of Keratinocyte Derived Exosome on Proliferation and Migration on Human Skin Keratinocyte

: Exosome, a small vesicle secreted from cells, has diverse functions depending on cell origins and tissue types and plays a important role in cell viability and intercellular communication. Recently, many researchers have demon-strated the use of exosomes for the treatment of cancers and immune diseases, and the development of diagnostic biomarker. However, the secretion mechanism of exosome from skin cell and its physiological functions in skin remain unclear. Thus, this study aimed to explore whether keratinocyte-derived exosome affects proliferation and migration in HaCaTs. Exosomes were isolated from HaCaTs by ExoQuick-TC and then boiled or unbolied. Boiled and unboiled exosome induced proliferation in HaCaTs in a dose-dependant manner (0.1 ∼ 20 µ g/mL), respectively. Boiled and unboiled exosome at concentration of 20 µ g/mL increased proliferation level in HaCaTs by 186.96 ± 3.87% and 193.48 ± 10.48% compared with control group. Unboiled exosome stimulated migration in HaCaTs in a dose-dependent manner (0.1 ∼ 20 µ g/mL), which reached a maxium at concentration of 20 µ g/mL (179.39 ± 4.89% of control), but boiled exosome did not affect HaCaT migration. In addition, unboiled exosome (0.1 ∼ 20 µ g/mL) dose-dependently stimulated sprout outgrowth in HaCats. These results demonstrate that in exosome from HaCaTs, heat-stable components such as lipid may induce HaCaT proliferation and heat-unstable components such as protein may stimulate migration and sprout outgrowth in HaCaTs, thereby leading to reepithelialization and skin-wound healing activities. It is concluded that exosomes from HaCaTs may be used as cosmetic materials.