Abstract: Objective To explore the experimental study of Scutellaria extract on IL-22-induced proliferation, apoptosis and inflammatory response of human keratinocyte cells line (HaCaT) via miR-369-3p. Methods HaCaT cells were divided into control group, IL-22 group (cell models, 100 ng/mL of IL-22 cultured cells), low, medium and high dose group (Scutellaria extract 50, 100, 150 μg/mL), anti-miR-NC intervention group (transfected anti-miR-NC), anti-miR-369-3p intervention group (transfected with anti-miR-369-3p), miR-NC+high-dose group (transfected with miR-NC, Scutellaria extract cultured cells), miR-369-3p+high-dose group (transfected with miR-369-3p, Scutellaria extract cultured cells). MTT experiment detected cell proliferation; Flow cytometry detected cell apoptosis; Western blot detected cleaved caspase-3 protein expression;ELISA detected TNF-α and IL-6 content; RT-qPCR detected miR-369-3p expression. Results Compared with the control group, the IL-22 group cell survival rate, miR-369-3p expression, TNF-α, IL-6 expression increased(P<0.05), and the difference in the cell apoptosis rate, cleaved caspase-3 protein expression were not signficantly(P＞0.05); Compared with the IL-22 group, the cell survival rate, miR-369-3p expression, TNF-α, IL-6 expression decreased in the low, middle and high dose groups, while the apoptosis rate, cleaved caspase-3 protein expression increased(P<0.05). Compared with the anti-miR-NC intervention group, the anti-miR-369-3p intervention group had lower cell viability, TNF-α, IL-6 expression, while apoptosis rate, cleaved caspase-3 protein expression increased(P<0.05). Over-expression of miR-369-3p could partially reverse the effects of Scutellaria extract on cell viability, apoptosis and inflammatory response of psoriasis cell models. Conclusions Scutellaria extract inhibits IL-22-induced hyperproliferation and inflammatory response of human keratinocytes, and promotes apoptosis with potential mechanisms by inhibiting the expression of miR-369-3p.

Key words: psoriasis, Scutellaria extract, miR-369-3p, IL-22, human keratinocytes, inflammatory reaction