Repression of miR-142-3p alleviates psoriasis-like inflammation by repressing proliferation and promoting apoptosis of keratinocytes via targeting Sema3A.

Psoriasis is a multifactorial, recurring, and chronic inflammatory skin disease characterized by hyperproliferation of keratinocytes. Evidence is rapidly accumulating for the role of microRNAs in psoriasis. The object of the study was to explore the functions and precise mechanism of miR-142–3p in human keratinocyte HaCaT cells in the presence of M5. Here, the results showed that miR-142–3p expression was heightened in HaCaT cells induced by M5. In addition, inhibition of miR-142–3p dramatically restricted cell proliferation and enhanced apoptosis in HaCaT cells exposed to M5, as exemplified by a decrease in the antiapoptotic Bcl-2 protein, concomitant with an increase in the proapoptotic proteins Bax. Moreover, depleting miR-142–3p effectively ameliorated M5-induced inflammation response, as reflected by the attenuation of multiple inflammatory factors. Importantly, Sema3A was identified as an authentic target of miR-142–3p, and indeed regulated by miR-142–3p. Mechanistically, silencing of Sema3A effectively abolished the anti-proliferative, apoptosis-promoting, and anti-inflammatory effects of miR-142–3p inhibition in keratinocytes. Taken together, these data elucidated that repression of miR-142–3p protect HaCaT cells against M5-induced hyper-proliferation and inflammatory injury by suppressing its target Sema3A, implying that the miR-142–3p/Sema3A axis may be a new target for preventing keratinocyte injury process. These findings provide a new and better understanding of the mediating role of miR-142–3p in psoriasis.