Lin Po-Shuen, Chang Mei-Chi, Chan Chiu-Po, Lee Sheng-Yang, Lee Jang-Jaer, Tsai Yi-Ling, Tseng Hui-Chun, Tai Tseng-Fang, Lin Hsueh-Jen, Jeng Jiiang-Huei
Department of Dentistry/School of Dentistry, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2011 Mar;111(3):394-400. doi: 10.1016/j.tripleo.2010.09.079. Epub 2011 Jan 13.
Transforming growth factor β1 (TGF-β1) plays a role in repair and dentinogenesis in dental pulp. The purpose of this study was to study how TGF-β1 affects 2 differentiation markers, Runt-related transcription factor 2 (Runx-2) and ALP, in dental pulp cells.
Primary-cultured human dental pulp cells were treated with TGF-β1 with or without pretreatment and coincubation with 1,4-diamino-2,3-dicyano-1,4-bis(o-aminophenylmercapto)butadiene (U0126, a mitogen-induced extracellular kinase (MEK)/extracellular signal-regulated kinase (ERK) inhibitor), Noggin (a bone morphogenetic protein inhibitor), or 4-(5-benzol[1,3]dioxol-5-yl-4-pyrldin-2-yl-1H-imidazol-2-yl)-benzamide hydrate (SB431542, an activin receptor-like kinase (ALK) 5/Smad2/3 inhibitor). The differentiation status of pulp cells was evaluated by ALP staining and quantitative ALP activity assay. Changes in ALP and Runx-2 mRNA expression were determined by reverse-transcription polymerase chain reaction.
Cells under the treatment of TGF-β1 (5 and 10 ng/mL) showed a decrease in ALP activity and gene expression of ALP and Runx-2. Pretreatment by U0126 and Noggin was not effective to prevent the TGF-β1-induced decline of ALP activity. Interestingly, SB431542 prevented the TGF-β1-induced decline of ALP activity and ALP and Runx-2 gene expression.
TGF-β1 down-regulates Runx-2 and ALP in human dental pulp cells via ALK5/Smad2/3 signaling. These events may play important roles at specific stages of pulpal repair and dentinogenesis.
转化生长因子β1（TGF-β1）在牙髓修复和牙本质形成过程中发挥作用。本研究旨在探讨TGF-β1如何影响牙髓细胞中的两种分化标志物，即Runx相关转录因子2（Runx-2）和碱性磷酸酶（ALP）。
对原代培养的人牙髓细胞进行处理，分别用TGF-β1单独处理，或在预处理及共孵育时添加1,4-二氨基-2,3-二氰基-1,4-双（邻氨基苯基巯基）丁二烯（U0126，一种丝裂原诱导的细胞外激酶（MEK）/细胞外信号调节激酶（ERK）抑制剂）、Noggin（一种骨形态发生蛋白抑制剂）或4-（5-苯并[1,3]二氧杂环戊烯-5-基-4-吡啶-2-基-1H-咪唑-2-基）-苯甲酰胺水合物（SB431542，一种激活素受体样激酶（ALK）5/Smad2/3抑制剂）。通过ALP染色和定量ALP活性测定评估牙髓细胞的分化状态。采用逆转录聚合酶链反应测定ALP和Runx-2 mRNA表达的变化。
用TGF-β1（5和10 ng/mL）处理的细胞显示ALP活性以及ALP和Runx-2的基因表达降低。U0126和Noggin预处理未能有效阻止TGF-β1诱导的ALP活性下降。有趣的是，SB431542可阻止TGF-β1诱导的ALP活性以及ALP和Runx-2基因表达的下降。
TGF-β1通过ALK5/Smad2/3信号通路下调人牙髓细胞中的Runx-2和ALP。这些事件可能在牙髓修复和牙本质形成的特定阶段发挥重要作用。
