IL-1 Alpha Regulates CXCL1, CXCL10 and ICAM1 in Network Form in Oral Keratinocytes

Background: Keratinocytes are the major constituent of epithelial cells at skin and mucosal surfaces such as oral mucosa. In our previous study, it was indicated that oral keratinocytes play active roles in oral mucosal adaptive immune response and an IL-alpha sub-network was identified. In the past decades IL-1, a revolutionarily ancient cytokine, has attracted our attention for its important roles in innate and adaptive immune responses. In this study we aim to show the IL-alpha sub-network in oral keratinocytes and explore its relevance in oral lichen planus (OLP). Methods: We first tested whether IL-1 alpha regulated its sub-network genes including CXCL1, CXCL10, and ICAM1 mRNA levels in time and concentration dependent manners by real time PCR. Then we investigated the expression of IL-1 alpha and CXCL1 in OLP tissues by immunohistochemical staining. Results: IL-1 alpha regulated its sub-network genes including CXCL1, CXCL10, and ICAM1 mRNA levels in time dependent but not in concentration dependent manner. Immunohistochemistry studies showed that IL-1 alpha and CXCL1 were expressed in OLP tissues, which were only detected in tissue transudate and whole unstimulated saliva in previous studies. Conclusions: IL-1 alpha regulates CXCL1, CXCL10, and ICAM1 in network form in oral keratinocytes. A complete characterization of the IL-1 alpha sub-network will shed light on the exploration of IL-1 as the therapeutic target in OLP and help to illuminate the multiple regulatory functions of keratinocytes in oral mucosa or even in other mucosa sites.