Background: Psoriasis is a common cutaneous disease with many characteristics including inflammation and aberrant keratinocyte proliferation. However, the pathogenesis of psoriasis is not completely clear.
Methods: We explore the differentially expressed genes (DEGs) in psoriasis by analyzing the gene expression profile obtained from the Gene Expression Omnibus (GEO) database. The DEGs were examined by gene ontology (GO) functional enrichment analysis and protein-protein interactions (PPI) network. Correlation analysis in R studio software analyzed the association of SPRR and LCE genes. The potential direct protein-protein interactions between SPRR proteins and LCE3D was further verified by co-localization observed in 293T cells and co-immunoprecipitation (CO-IP). The expression levels of SPRR and LCE genes were detected in the IMQ-induced psoriasiform dermatitis mice.
Results: The small proline-rich (SPRR) and late cornified envelope (LCE) genes were identified as a module in constructed PPI network. The gene expression profile GSE63684 analysis showed that both SPRR family and LCE family genes were significantly upregulated in imiquimod (IMQ) induced psoriasiform dermatitis mice. Correlation analysis in R studio software recognized the association of SPRR and LCE genes, in which the potential direct protein-protein interactions between SPRR proteins and LCE3D was further verified by co-localization observed in 293T cells and co-immunoprecipitation (CO-IP) results that suggest direct interaction between SPRR2 and LCE3D. Notably, we found that the expression levels of SPRR and LCE genes were significantly increased in the IMQ-induced psoriasiform dermatitis mice while tazarotene cream treatment specifically decreased the mRNA expression of these genes, which indicated that the SPRR and LCEs were regulated simultaneously in psoriasis.
Conclusion: Our studies found the interactions of SPRR proteins with LCE proteins, which may provide new insights into the pathogenesis of psoriasis.