Altered expression of CCN1 in oral lichen planus associated with keratinocyte activation and IL-1β, ICAM1 and CCL5 up-regulation.

BACKGROUND Emerging evidence indicates that CCN1 is a novel inflammation-regulated mediator involved in the pathogenesis of some immune-mediated inflammatory diseases. The objective of this study was to investigate the preliminary roles of CCN1 and it related cytokines IL-1β, CCL5, and ICAM1 in oral lichen planus (OLP). METHODS CCN1 expression levels in biopsies from OLP patients against normal oral mucosa (NOM) using immunohistochemistry (42 OLP vs 9 NOM) and RT-qPCR (20 OLP vs 20 NOM) were compared, respectively. The correlation of CCN1 and IL-1β, CCL5, and ICAM1 expression was examined by RT-qPCR in tissue samples and an in vitro cell culture system using keratinocyte HaCaT cells incubated with lipopolysaccharides. RESULTS Immunohistochemistry showed that CCN1 protein mainly expressed in the cytoplasm of epithelial keratinocytes of OLP. Consistently, RT-qPCR revealed that mRNA expression of CCN1 were increased in OLP compared with NOM (P<0.05), and positively correlated with the high expression of IL-1β, ICAM1 and CCL5 (P<0.001), respectively. Importantly, an in vitro study showed that keratinocyte proliferation significantly (P<0.05) increased by CCN1 stimulation. Moreover, IL-1β, ICAM1 and CCL5 expression in keratinocytes stimulated by CCN1 was increased (P<0.05), respectively. CONCLUSIONS This preliminary study for the first time reported that altered expression of CCN1 was associated with high expression of IL-1β, ICAM1 and CCL5 in OLP. And we demonstrated CCN1 promoted keratinocyte activation, as well as IL-1β, ICAM1 and CCL5 production in keratinocytes. Our data indicated that the potential role of CCN1 and its related cytokines was involved in the pathogenesis of OLP.