Reduced WNT4 expression in normal skin fibroblasts leads to 'Dupuytren-like' changes in the transcriptome.

Background: Dupuytren's disease (DD) is a fibro-proliferative disorder of unknown aetiology. Previous studies have implicated multiple WNT signalling genes/proteins in Dupuytren pathology, including WNT4. However, it is not yet clear whether WNT signalling dysregulation plays an important role in the initiation of the disease or progression. The aim of this study was to determine if loss of WNT4 expression triggered 'Dupuytren-like' changes in the transcriptome of healthy skin fibroblasts.

Methods: Fibroblasts were isolated from the wrists of healthy adult males and from the wrists and disease cord tissue from males in a family positive for Dupuytren's disease. Normal skin fibroblasts from healthy controls were treated with WNT4 siRNA and scrambled controls. RNASeq was used to analyse the transcriptomes of disease and non-disease fibroblasts from patients with Dupuytren's as well as in siRNA treated and non-treated control fibroblasts.

Results: Analysis of the transcriptomes from DD patient and normal skin fibroblasts showed significant differences, including in WNT4 expression. Downregulation of WNT4 in normal skin fibroblasts using siRNA led to 'DD-like' changes in the transcriptome.

Conclusion: In people susceptible to DD WNT4 is downregulated even in non-fibrotic fibroblasts. Knockdown of WNT4 in normal fibroblasts led to changes that made cells 'DD-like'. This study shows that WNT4 is down regulated in 'non-disease' cells, and that downregulating WNT4 in normal skin fibroblasts leads to widespread 'DD like' changes in the transcriptome, suggesting WNT4 downregulation is a key driver of DD.