Icariin ameliorates TNF-α/IFN-γ-induced oxidative stress, inflammatory response and apoptosis of human immortalized epidermal cells through the WTAP/SERPINB4 axis.

Abstract

Atopic dermatitis (AD) is a chronic inflammatory skin disorder characterized by increased sensitivity to environmental allergens and irritants. Icariin, a natural compound extracted from the herb Epimedium, has been traditionally used for its potential anti-inflammatory and antioxidant properties. This study aimed to investigate the regulatory effects of icariin on AD-like symptoms and to elucidate its underlying mechanisms. The effects of icariin on TNF-α/IFN-γ-induced HaCaT cell injury were assessed using various assays, including cell counting kit-8 for cell viability, flow cytometry for reactive oxygen species (ROS) levels, and colorimetric assays for malondialdehyde (MDA) levels and superoxide dismutase (SOD) activity. In addition, the study performed enzyme-linked immunosorbent assays to assess cytokines (IL-1β, IL-6, and IL-8) and chemokines (MDC, TARC, and RANTES) levels. Flow cytometry was used to quantify apoptotic rate, while a wound-healing assay was conducted to assess cell migration. The expression of WT1 associated protein (WTAP) and serpin family B member 4 (SERPINB4) at the mRNA and protein levels was determined using qRT-PCR and western blotting, respectively. The associations between WTAP and SERPINB4 were analyzed using RNA immunoprecipitation assay and m6A RNA immunoprecipitation assay. Icariin treatment significantly mitigated TNF-α/IFN-γ-induced oxidative stress, inflammatory response, and apoptosis in HaCaT cells, while also reversing the inhibitory effect on cell migration. Icariin reduced the expression of WTAP in TNF-α/IFN-γ-stimulated HaCaT cells. Overexpression of WTAP reversed the effects of icariin in TNF-α/IFN-γ-stimulated HaCaT cells. WTAP silencing inhibited the mRNA stability of SERPINB4 through the m6A modification. SERPINB4 overexpression attenuated the effects of WTAP silencing on oxidative stress, inflammatory response, apoptosis, and migration of TNF-α/IFN-γ-stimulated HaCaT cells. Icariin treatment downregulated SERPINB4 expression by regulating WTAP in TNF-α/IFN-γ-stimulated HaCaT cells. Icariin ameliorated TNF-α/IFN-γ-induced human immortalized epidermal cell injury through the WTAP/SERPINB4 axis, highlighting the potential for targeted interventions in AD pathogenesis.