Role of mammary serine protease inhibitor on the inflammatory response in oral lichen planus

Abstract

Oral lichen planus (OLP) is a chronic inflammatory condition with an unclear pathological mechanism. IκB kinase α (IKKα)-regulated mammary serine protease inhibitor (MASPIN) has been shown to mediate inflammation, particularly in cancers. Here, we explored the expression of MASPIN in OLP and its role in the inflammatory response. Immunohistochemistry staining and reverse transcription-polymerase chain reaction assays were used to detect the subcellular localization and expression of MASPIN and IKKα in OLP and healthy control tissues. Levels of the inflammatory factors were compared with enzyme-linked immunosorbent assays. MASPIN and IKKα were overexpressed and silenced, respectively, in an inflammation model of human oral keratinocytes (HOKs) stimulated with lipopolysaccharide (LPS). Mammary serine protease inhibitor expression was down-regulated, whereas IKKα expression was up-regulated in OLP tissues (p<0.01). The levels of tumour necrosis factor-alpha and interleukin-6 in OLP tissues were increased compared to those of healthy controls (p<0.01). MASPIN overexpression in LPS-stimulated HOK cells inhibited the levels of IKKα and the secretion of inflammatory cytokines. By contrast, IKKα silencing promoted the expression of MASPIN and inhibited the secretion of inflammatory cytokines. Both MASPIN and IKKα are involved in the inflammatory process of OLP, suggesting potential therapeutic targets.