Periodontal disease (PD) is one of the main causes of periodontal bone resorption and tooth loss in adults. How to repair the alveolar bone effectively has always been a challenge. This study was designed to clarify the effects and the underlying molecular mechanisms of chlorogenic acid (CGA) on osteogenic differentiation of human dental pulp stem cells (hDPSCs). In this study, we used CGA to treat hDPSCs. The osteogenic experiment showed that CGA can promote hDPSCs osteogenic differentiation. RNA-Seq and quantitative real-time polymerase chain reaction showed that CGA treatment enhanced the expression of the osteogenesis genes for frizzled-related protein (FRZB) and pyruvate dehydrogenase kinase 4 (PDK4) and inhibit the expression of the osteoclastogenesis genes such as those for asporin (ASPN) and cytokine-like 1 (CYTL1). Western blot analysis showed that besides FRZB, CGA treatment also caused reduction of both active and total β-catenin, while increased the total calcium/calmodulin-dependent kinase II (CamKII), the phosphorylated CamKII (pCamKII) and the phosphorylated cAMP-response element-binding protein (pCREB). Likely, the increased osteogenesis was associated with reduced canonical Wnt/β-catenin signaling but increased noncanonical Wnt/Ca²⁺ signaling. The results suggested that CGA can promote the osteogenic differentiation of hDPSCs by regulating Wnt signaling. These findings will serve as a foundation for further studies on how to repair defective alveolar bone for the patients with PD.

中文翻译：

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绿原酸通过 Wnt 信号促进人牙髓干细胞的成骨分化

牙周病（PD）是成人牙周骨吸收和牙齿脱落的主要原因之一。如何有效修复牙槽骨一直是一个挑战。本研究旨在阐明绿原酸（CGA）对人牙髓干细胞（hDPSCs）成骨分化的影响及其潜在分子机制。在本研究中，我们使用 CGA 治疗 hDPSC。成骨实验表明CGA可以促进hDPSCs成骨分化。RNA-Seq 和定量实时聚合酶链反应表明，CGA 处理增强了卷曲相关蛋白(FRZB ) 和丙酮酸脱氢酶激酶 4 ( PDK4 ) 的成骨基因的表达) 并抑制破骨细胞生成基因的表达，例如 asporin (ASPN )和细胞因子样 1 ( CYTL1 )。蛋白质印迹分析表明，除 FRZB 外，CGA 处理还导致活性和总 β-连环蛋白减少，同时增加总钙/钙调蛋白依赖性激酶 II (CamKII)、磷酸化 CamKII (pCamKII) 和磷酸化 cAMP 反应元件结合蛋白（pCREB）。可能，增加的成骨与减少的经典 Wnt/β-连环蛋白信号传导有关，但增加的非经典 Wnt/Ca ²⁺发信号。结果表明，CGA可通过调节Wnt信号促进hDPSCs的成骨分化。这些发现将为进一步研究如何修复PD患者有缺陷的牙槽骨奠定基础。