Expression of β-catenin in Skin Lesions of Patients with Scleroderma and Its Effect on Epithelial-Mesenchymal Transition of Human Epidermal Keratinocytes

  Objective  To investigate the expression of β-catenin in the skin lesions of patients with systemic scleroderma (SSc) and its effect on epithelial-mesenchymal transition (EMT) of human epidermal keratinocytes.

  Methods  The expression of β-catenin, Snail1 and E-cadherin in the skin lesions sample of 45 SSc patients and normal skin sample from 20 healthy adults was detected with SP immunohistochemistry. HaCaT, the human epidermal keratinocytes, were treated with different concentrations of Wnt10b (0 ng/mL (control), 2 ng/mL and 4 ng/mL) for 48 h. then detected the localization of β-catenin in HaCaT cells by immunofluorescence assay, determined the mRNA levels of Snail1 and Snail2 in HaCaT cells by real-time fluorescent quantitative PCR, detected the proteins expression of β-catenin, Vimentin, N-cadherin and E-cadherin in HaCaT cells by Western blot.

  Results  The positive rates of β-catenin, Snail1 and E-cadherin in skin lesions of SSc patients were 100%, 88.89% and 2.22% respectively, while in healthy adult skin, the corresponding positive rates were 0%, 10.00%, and 95.00%. The difference between the two groups was significant. Compared with control group, treatment with different concentrations of Wnt10b (2 ng/mL and 4 ng/mL) induced up-regulation of β-catenin expression and promoted translocation of β-catenin from cytoplasm to nucleus, increased the mRNA levels of Snail1 and Snail2 (P < 0.05), and up-regulated the proteins expression of Vimentin, N-cadherin, down-regulated the E-cadherin protein expression in HaCaT cells (P < 0.05).

  Conclusion  Abnormally activated Wnt/β-catenin signaling pathway and abnormally expressed EMT-related proteins are observed in SSc lesions. Activation of Wnt/β-catenin signaling pathway may promote EMT in HaCaT cells.