Department of Conservative Dentistry, School of Dentistry, Dental Science Research Institute, Chonnam National University, Gwangju, Republic of Korea.
Department of Conservative Dentistry, School of Dentistry, Dental Science Research Institute, Chonnam National University, Gwangju, Republic of Korea; Department of Endodontics, School and Hospital of Stomatology, Wenzhou Medical University, Wenzhou, China.
J Endod. 2023 Dec;49(12):1660-1667. doi: 10.1016/j.joen.2023.09.010. Epub 2023 Sep 27.
Osteolectin is a secreted glycoprotein of the C-type lectin domain superfamily, expressed in bone tissues and is reported as a novel osteogenic factor that promotes bone regeneration. However, the effect of osteolectin on human dental pulp cells (hDPCs) has not been reported. Therefore, we aimed to investigate the odontoblastic differentiation of osteolectin in hDPCs and further attempt to reveal its underlying mechanism.
Cytotoxicity assays were used to detect the cytotoxicity of osteolectin. The odontoblastic differentiation of hDPCs and its underlying mechanisms were measured by the alkaline phosphatase (ALP) activity, mineralized spots formation, and the gene and protein expression of odontoblastic differentiation through ALP staining, Alizarin red S staining, quantitative real-time polymerase chain reaction, and Western blot analysis, respectively.
WST-1 assay showed osteolectin at concentrations below 300 ng/ml was noncytotoxic and safe for hDPCs. The following experiment demonstrated that osteolectin could increase ALP activity, accelerate the mineralization process, and up-regulate the odontogenic differentiation markers in both gene and protein levels (P < .05). Osteolectin stimulated the phosphorylation of ERK, JNK, and Protein kinase B (AKT) in hDPCs. Extracellular signal-regulated kinase (ERK), Jun N-terminal kinase (JNK), and AKT inhibitors decreased ALP activity and mineralization capacity and suppressed the expression of dentin sialophosphoprotein and dentin matrix protein-1.
Osteolectin can promote odontoblastic differentiation of hDPCs, and the whole process may stimulate ERK, JNK, and AKT signaling pathways by increasing p-ERK, p-JNK, and p-AKT signals.
骨连蛋白是 C 型凝集素结构域超家族的一种分泌糖蛋白，在骨组织中表达，被报道为一种促进骨再生的新型成骨因子。然而，骨连蛋白对人牙髓细胞（hDPCs）的影响尚未报道。因此，我们旨在研究骨连蛋白在 hDPCs 中的成牙本质分化作用，并进一步尝试揭示其潜在机制。
采用细胞毒性测定法检测骨连蛋白的细胞毒性。通过碱性磷酸酶（ALP）活性、矿化斑形成以及 ALP 染色、茜素红 S 染色、定量实时聚合酶链反应和 Western blot 分析检测 hDPCs 的成牙本质分化及其潜在机制，分别测量碱性磷酸酶（ALP）活性、矿化斑形成以及牙本质分化相关基因和蛋白的表达。
WST-1 检测表明，浓度低于 300ng/ml 的骨连蛋白对 hDPCs 无细胞毒性且安全。后续实验表明，骨连蛋白可增加 ALP 活性，加速矿化过程，并上调牙源性分化标志物的基因和蛋白水平（P<.05）。骨连蛋白刺激 hDPCs 中细胞外信号调节激酶（ERK）、c-Jun 氨基末端激酶（JNK）和蛋白激酶 B（AKT）的磷酸化。ERK、JNK 和 AKT 抑制剂降低了 ALP 活性和矿化能力，并抑制了牙本质涎磷蛋白和牙本质基质蛋白-1 的表达。
骨连蛋白可促进 hDPCs 的成牙本质分化，这一过程可能通过增加 p-ERK、p-JNK 和 p-AKT 信号来刺激 ERK、JNK 和 AKT 信号通路。
