β-catenin在硬皮病皮损中的表达及其对人表皮角质形成细胞上皮-间质转化的影响

  目的  探讨β-连环蛋白(β-catenin)在系统性硬皮病(SSc)患者皮损中的表达及其对人表皮角质形成细胞上皮-间质转化(EMT)的影响。  方法  采用免疫组织化学SP法检测45例SSc患者皮损组织及20例健康成人皮肤组织中β-catenin、Snail1、上皮性钙黏附蛋白(E-cadherin)的表达情况。采用不同质量浓度Wnt10b〔0(空白对照)、2、4 ng/mL〕处理人表皮角质形成细胞HaCaT 48 h，免疫荧光实验检测β-catenin在HaCaT细胞中的定位；实时荧光定量PCR检测HaCaT细胞中Snail1、Snail2 mRNA水平；Western blot法检测HaCaT细胞中β-catenin、波形蛋白(Vimentin)、神经性钙黏附蛋白(N-cadherin)、E-cadherin蛋白表达。  结果  β-catenin、Snail1、E-cadherin阳性率在SSc患者皮损组织中依次为100%、88.89%和2.22%，在健康成人皮肤组织中依次为0%、10.00%和95.00%，两组比较差异均有统计学意义(P < 0.05)。与空白对照组比较，不同质量浓度Wnt10b(2、4 ng/mL)处理可诱导HaCaT细胞中β-catenin表达上调并促进β-catenin由细胞质向细胞核中转位，同时还可以提高HaCaT细胞中Snail1和Snail2 mRNA表达(P < 0.05)，并上调Vimentin、N-cadherin蛋白表达和下调E-cadherin蛋白表达(P < 0.05)。  结论  SSc皮损中存在异常活化的Wnt/β-catenin信号通路及异常表达的EMT相关蛋白，且激活Wnt/β-catenin信号通路可促进HaCaT细胞EMT的发生。

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.