Myricetin enhances keratinocytes differentiation via TRPV4 channel activation in mouse primary keratinocytes

The skin serves as the primary defensive barrier of the human body against external stimuli and damage. Keratinocytes, which are the predominant cell type in the human epidermis, undergo a differentiation process that is crucial for the formation of the skin barrier. Myricetin, a dietary flavonoid present in various fruits and vegetables, is known to play a significant role in maintaining intestinal barrier function; however, its impact on the skin barrier remains inadequately understood. Consequently, this study investigates the effects of myricetin on the differentiation of epidermal keratinocytes and the integrity of the skin barrier. Differentiation of primary mouse keratinocytes was induced using 1.8 mM CaCl₂. tudy demonstrated that myricetin effectively suppresses cell proliferation and induces both cell cycle arrest and calcium ion (Ca²⁺) influx, without influencing apoptosis. Concurrently, myricetin enhances the expression of differentiation markers, including K10, TGase1, Filaggrin, and Involucrin, and facilitates the formation of tight junctions. Upon examining the underlying mechanisms, we discovered that myricetin activates the TRPV4 channel, and the promotion of keratinocyte differentiation by myricetin is contingent upon the activation of this channel. In summary, these findings suggested that myricetin could promote keratinocytes differentiation and have well-established skin barrier protective function.