Intercellular communication mediated by EVs is modulated during the aging process in keratinocytes and might be involved in the functional defects observed in aged skin.

Aging modulates extracellular vesicles of epidermal keratinocytes, new research in Aging suggests.

The disturbance of intercellular communication is one of the hallmarks of aging. In their new study, researchers  from the University of Lyon, Toyo University and Gattefossé SAS aimed to clarify the impact of chronological aging on extracellular vesicles (EVs), a key mode of communication in mammalian tissues. 

The researchers focused on epidermal keratinocytes, the main cells of the outer protective layer of the skin which is strongly impaired in the skin of elderly. EVs were purified from conditioned medium of primary keratinocytes isolated from infant or aged adult skin. A significant increase of the relative number of EVs released from aged keratinocytes was observed whereas their size distribution was not modified.

By small RNA sequencing, the researchers described a specific microRNA (miRNA) signature of aged EVs with an increase abundance of miR-30a, a key regulator of barrier function in human epidermis. EVs from aged keratinocytes were found to be able to reduce the proliferation of young keratinocytes, to impact their organogenesis properties in a reconstructed epidermis model and to slow down the early steps of skin wound healing in mice, three features observed in aged epidermis. This work reveals that intercellular communication mediated by EVs is modulated during aging process in keratinocytes and might be involved in the functional defects observed in aged skin. “To conclude, we have shown here that aging modulates EVs abundance, function and microRNA content in human keratinocytes,” the researchers conclude.

PHOTO CAPTION: Figure 5. Aged EVs impact proliferation of young keratinocytes in 2D culture.

PHOTO CREDIT: 2023 Nedachi et al.