Abstract
WNT/β-catenin signaling pathways play a pivotal role in the human immune defense against infections and in chronic inflammatory conditions as psoriasis. Wnt gene alterations are linked to known comorbidities of psoriasis as obesity, diabetes and Crohn's disease. The objective of this study was to investigate WNT7B, WNT10B, WNT16 and TCF7L2 gene and protein expression in lesional and non-lesional skin and in the peripheral blood of patients with chronic plaque psoriasis compared with healthy individuals. To investigate the effect of narrowband UVB radiation, expression of these genes were analyzed before and after narrowband UVB treatment. Associations between single nucleotide polymorphisms for WNT7B, WNT10B, WNT16 and TCF7L2 genes and psoriasis were tested. Our results show significantly decreased WNT7B, WNT10B and TCF7L2 gene expression in lesional skin compared with non-lesional skin and healthy controls. Narrowband UVB treatment significantly increased expression of these genes in lesional skin. Immunohistochemistry shows increased WNT16 expression in lesional skin. No significant differences in allele or genotype frequencies for Wnt or TCF7L2 gene polymorphisms were found between patient and control group. This study shows for the first time significant UVB induced upregulation of WNT7B, WNT10B and TCF7L2 in patients with psoriasis and suggests a potential role of these genes in psoriasis pathogenesis.