Psoriasis, a chronic inflammatory skin disorder disease, is closely associated with hyperproliferation of keratinocytes. Upregulated miR-223 has been found in peripheral blood mononuclear cells from patients with psoriasis and from psoriatic skin. However, its role in keratinocytes remains unknown. We thus aimed to investigate the function of miR-223 in psoriasis. Interleukin-22 (IL-22) is a crucial keratinocyte trigger in the T-cell-mediated immune response to psoriasis. We found miR-223 to be overexpressed in psoriatic lesions and in IL-22-stimulated HaCaT cells. HaCaT cells then were transfected with a miR-223 mimic or inhibitor to overexpress or inhibit expression of miR-223, respectively. A Cell Counting Kit-8 assay revealed that miR-223 overexpression promoted and miR-223 downregulation inhibited proliferation in IL-22-stimulated HaCaT cells. Flow cytometry analysis certified that miR-223 overexpression decreased HaCaT cell apoptosis, whereas miR-223 downregulation increased it. A dual-luciferase reporter assay demonstrated that miR-223 directly targeted the phosphatase and tensin homolog (PTEN) gene. MiR-223 also negatively regulated mRNA and protein expression of PTEN and modulated the PTEN/Akt pathway in IL-22-stimulated HaCaT cells. PTEN silencing attenuated the activity of the miR-223 inhibitor in these cells via the PTEN/Akt pathway. Overall, the results showed that miR-223 increased proliferation and inhibited apoptosis of IL-22-stimulated keratinocytes via the PTEN/Akt pathway.
Keywords: Interleukin-22; Keratinocytes; Phosphatase and tensin homolog; Psoriasis; miR-223.
Copyright © 2019. Published by Elsevier Inc.