中文摘要：

目的研究sFRP5抑制Wnt3a对黑素细胞黑素形成的作用。方法以永生化的黑素细胞为模型，利用腺病毒表达载体，设置Control组、Wnt3a处理组、Wnt3a＋sFRP5处理组进行以下实验：L—DOPA测定酪氨酸酶（tyrosinase，TYR）活性；Masson—Fontanas银染色法观察黑素形成情况；RT-PCR检测酪氨酸酶相关蛋白1（tyrosinase-relatedprotein1，TRP-1）、TYR基因的表达；Westernblot检测TRP-1、TYR蛋白的表达水平。结果L—DOPA测定酪氨酸酶活性结果显示Wnt3a＋sFRP5处理组TYR活性低于Wnt3a处理组，差异有统计学意义（P〈0．05）；Masson—Fontanas银染色法显示Wnt3a＋sFRP5处理组形成的黑素明显低于Wnt3a处理组；RT—PCR检测结果显示Wnt3a＋sFRP5处理组能下调TRP-1、TYR基因的表达（P〈0．05）；Westernblot检测结果显示Wnt3a＋sFRP5处理组能下调TRP-1、TYR蛋白的表达水平（P〈0．05）。结论sFRP5能抑制Wnt3a对黑素细胞黑素生成的作用。

英文摘要：

Objective To explore the effects of secreted Frizzled-related protein 5 （sFRPS） inhibiting Wnt3a on the melanin formation of melanocytes. Methods With immortalized melanocytes as model and adenoviral vectors, we set up 3 experimental groups, melanoeytes transfected with Ad-GFP （Ad-GFP group） , melanocytes transfected with Ad-Wnt3a （Ad-Wnt3a group） and melanocytes transfected with Ad-Wnt3a ＋ Ad- sFRP5 （Ad-Wnt3a ＋ Ad-sFRP5 group） to do the following experiments, including L-dopa tyrosinase activity assay, Masson-Fontanas silver staining for melanin formation detection, RT-PCR for testing expression of tyrosinase-related protein 1 （ TRP-1 ） and tyrosinase （ TYR）, and Western blotting for detecting the protein levels of TRP-1 and TYR in iMC23 cells. Results L-Dopa tyrosinase activity assay showed an obvious decrease in tyrosinase activity in the Ad-Wnt3a ＋ Ad-sFRP5 group as compared to Ad-Wnt3a group （P 〈 0. 05 ）. Masson-Fontanas silver staining found that melanin in the Ad-Wnt3a ＋ Ad-sFRP5 group was significantly lower than that in the Ad-Wnt3a group. RT-PCR results showed that the mRNA expression levels of TRP-1 and TYR were down-regulated in the Ad-Wnt3a ＋ Ad-sFRP5 group （P 〈 0.05 ）. Moreover, the protein levels of TRP-1 and TYR showed similar changes as proven by Western blotting （P 〈 0.05）. Conclusion SFRP5 can suppress the melanin formation of melanocytes through Wnt3a inhibition.