Wnt5a suppresses osteoblastic differentiation of human periodontal ligament stem cell-like cells via Ror2/JNK signaling
Wnt5a suppresses osteoblastic differentiation of human periodontal ligament stem cell-like cells via Ror2/JNK signaling
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DOI：
10.1002/jcp.26086
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发表时间：
2018-02-01
影响因子：
5.6
通讯作者：
Maeda, Hidefumi
中科院分区：
文献类型：
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作者：
Hasegawa, Daigaku;Wada, Naohisa;Maeda, Hidefumi
Wnt 5a是一种非经典的Wnt蛋白，已知在多种细胞功能中发挥重要作用。然而，很少有人知道Wnt 5a对牙周膜（PDL）细胞的成骨分化的影响。在这里，我们研究了Wnt 5a对人PDL干/祖细胞（HPDLSC）成骨细胞分化和相关细胞内信号传导的影响。我们发现，Wnt 5a抑制骨相关基因（ALP，BSP和Osterix）的表达和茜素红阳性矿化结节形成HPDLSCs成骨条件下。免疫组织化学分析显示，Wnt 5a相关受体，受体酪氨酸激酶样孤儿受体2（Ror 2），在大鼠PDL组织中表达。有趣的是，通过siRNA敲低Ror 2抑制了Wnt 5a诱导的HPDLSC中骨相关基因表达的下调。Western blotting分析显示，在含Wnt 5a的成骨诱导培养基中培养的HPDLSCs中，细胞内信号分子c-Jun N-末端激酶（JNK）的磷酸化水平上调，而siRNA敲低Ror 2则下调JNK的磷酸化水平。我们还研究了JNK抑制对Wnt 5a诱导的HPDLSC成骨细胞分化抑制的影响。JNK抑制剂SP 600125可抑制Wnt 5a诱导的HPDLSCs中骨相关基因表达的下调。此外，SP 600125抑制了Wnt 5a诱导的HPDLSC中茜素红阳性反应的抑制。这些结果表明，Wnt 5a通过Ror 2/JNK信号转导抑制HPDLSC的成骨分化。非经典Wnt信号传导，包括Wnt 5a/Ror 2/JNK信号传导，可以作为矿化的负调节剂，防止PDL组织中非生理性矿化的发展。
Wnt5a, a non-canonical Wnt protein, is known to play important roles in several cell functions. However, little is known about the effects of Wnt5a on osteoblastic differentiation of periodontal ligament (PDL) cells. Here, we examined the effects of Wnt5a on osteoblastic differentiation and associated intracellular signaling in human PDL stem/progenitor cells (HPDLSCs). We found that Wnt5a suppressed expression of bone-related genes (ALP, BSP, and Osterix) and alizarin red-positive mineralized nodule formation in HPDLSCs under osteogenic conditions. Immunohistochemical analysis revealed that a Wnt5a-related receptor, receptor tyrosine kinase-like orphan receptor 2 (Ror2), was expressed in rat PDL tissue. Interestingly, knockdown of Ror2 by siRNA inhibited the Wnt5a-induced downregulation of bone-related gene expression in HPDLSCs. Moreover, Western blotting analysis showed that phosphorylation of the intracellular signaling molecule, c-Jun N-terminal kinase (JNK) was upregulated in HPDLSCs cultured in osteoblast induction medium with Wnt5a, but knockdown of Ror2 by siRNA downregulated the phosphorylation of JNK. We also examined the effects of JNK inhibition on Wnt5a-induced suppression of osteoblastic differentiation of HPDLSCs. The JNK inhibitor, SP600125 inhibited the Wnt5a-induced downregulation of bone-related gene expression in HPDLSCs. Additionally, SP600125 inhibited the Wnt5a-induced suppression of the alizarin red-positive reaction in HPDLSCs. These results suggest that Wnt5a suppressed osteoblastic differentiation of HPDLSCs through Ror2/JNK signaling. Non-canonical Wnt signaling, including Wnt5a/Ror2/JNK signaling, may function as a negative regulator of mineralization, preventing the development of non-physiological mineralization in PDL tissue.