State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & Dept. of Cariology and Endodontics, West China Hospital of Stomatology, Sichuan University, No.14, Section 3, South Renmin Road, Chengdu, 610041, PR China.
State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & Dept. of Cariology and Endodontics, West China Hospital of Stomatology, Sichuan University, No.14, Section 3, South Renmin Road, Chengdu, 610041, PR China.
Arch Oral Biol. 2018 Mar;87:54-61. doi: 10.1016/j.archoralbio.2017.12.015. Epub 2017 Dec 15.
The aim of this study is to investigate the role of the WNT7B protein in the migration and differentiation of human dental pulp cells (HDPCs).
The effect of recombinant human WNT7B (rhWNT7B) on the proliferation and migration of HDPCs was evaluated by 5-ethynyl-2'-deoxyuridine (EdU), immunofluorescence staining of Ki67, flow cytometry and scratch assay; the differentiation of HDPCs was measured by alkaline phosphatase (ALP) staining, alizarin red staining, ALP activity, qPCR and western blot. The activation of the WNT/beta-catenin (WNT/β-catenin) and c-Jun N-terminal kinase (JNK) pathways was analysed by western blot, immunocytochemistry and dual luciferase assays. XAV939 and SP600125，the inhibitors of the WNT/β-catenin and JNK pathways, were further applied to verify the mechanism.
rhWNT7B repressed the proliferation but did not affect the apoptosis of HDPCs. In the presence of rhWNT7B, ALP and alizarin red staining were increased substantially in the HDPCs with osteogenic induction; the gene expression of Runx2 and Col1 in HDPCs was quite elevated compared with that induced in osteogenic medium without WNT7B measured by qPCR; The ALP activity was also increased with rhWNT7B stimulation in HDPCs after 7-day odontogenic culture; Western blot revealed that the expression of dentin sialophosphoprotein (DSPP) of HDPCs was up-regulated significantly with the addition of WNT7B as well. Further study showed that rhWNT7B activated the WNT/β-catenin and JNK signalling pathways in the differentiation of HDPCs. XAV939 and SP600125 can partly offset the effect of the WNT7B-induced differentiation of HDPCs.
WNT7B promoted the differentiation of HDPCs partly through the WNT/β-catenin and JNK signalling pathways.
本研究旨在探讨 WNT7B 蛋白在人牙髓细胞（HDPCs）迁移和分化中的作用。
通过 5-乙炔基-2'-脱氧尿苷（EdU）、Ki67 免疫荧光染色、流式细胞术和划痕试验评估重组人 WNT7B（rhWNT7B）对 HDPCs 增殖和迁移的影响；通过碱性磷酸酶（ALP）染色、茜素红染色、ALP 活性、qPCR 和 Western blot 测定 HDPCs 的分化。通过 Western blot、免疫细胞化学和双荧光素酶测定分析 WNT/β-连环蛋白（WNT/β-catenin）和 c-Jun N 末端激酶（JNK）通路的激活。进一步应用 XAV939 和 SP600125（WNT/β-catenin 和 JNK 通路的抑制剂）验证机制。
rhWNT7B 抑制 HDPCs 的增殖，但不影响其凋亡。在 rhWNT7B 存在的情况下，HDPCs 在成骨诱导下 ALP 和茜素红染色明显增加；与无 WNT7B 的成骨培养基诱导的 HDPCs 相比，qPCR 检测到 HDPCs 中 Runx2 和 Col1 的基因表达显著升高；rhWNT7B 刺激 HDPCs 后，经过 7 天的牙源性培养，ALP 活性也增加；Western blot 显示，HDPCs 中牙本质涎磷蛋白（DSPP）的表达也显著上调。进一步研究表明，rhWNT7B 在 HDPCs 分化过程中激活了 WNT/β-catenin 和 JNK 信号通路。XAV939 和 SP600125 可以部分抵消 WNT7B 诱导的 HDPCs 分化作用。
WNT7B 通过 WNT/β-catenin 和 JNK 信号通路促进 HDPCs 的部分分化。
