Twist negatively regulates osteoblastic differentiation in human periodontal ligament cells
Twist negatively regulates osteoblastic differentiation in human periodontal ligament cells
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DOI：
10.1002/jcb.21038
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发表时间：
2007-02-01
影响因子：
4
通讯作者：
Ishikawa, Isao
中科院分区：
文献类型：
--
作者：
Komaki, Motohiro;Karakida, Takeo;Ishikawa, Isao
牙周韧带（PDL）是位于牙槽骨和牙骨质这两种矿化组织之间的薄纤维结缔组织，在生理上保持恒定的宽度。 PDL 抵抗矿化的机制尚不清楚。 Twist 是一种基本的螺旋环螺旋蛋白，在早期成骨的调节中发挥着核心作用。我们研究了 Twist 在 PDL 中的定位，并将 PDL 细胞中 Twist 和成骨细胞相关基因的表达与存在或不存在重组人骨形态发生蛋白 (BMP)-2 的成骨细胞样细胞中的表达进行比较。组织化学分析表明，Twist 在 PDL 中沿牙槽骨表面表达。 PDL细胞组成型表达Twist基因，且表达水平高于成骨样细胞。在成骨细胞样细胞培养中，BMP-2增强了成骨细胞相关基因的表达，而Twist表达略有降低。相比之下，BMP-2增加了runt相关转录因子(Runx)-2，但未能增强PDL细胞中碱性磷酸酶(ALP)和骨钙素(OCN)基因的表达。有趣的是，与成骨细胞样细胞不同，PDL 细胞中 BMP-2 上调了 Twist 表达。我们使用短干扰RNA表达载体（siTwist）瞬时敲低PDL细胞中的Twist基因，发现ALP、骨桥蛋白（OPN）、骨唾液蛋白（BSP）基因表达和ALP活性的基础水平略有增加，而Runx2和OCN基因不受影响。总的来说，这些结果表明扭曲可能充当 PDL 细胞成骨细胞分化的负调节因子。
Periodontal ligament (PDL) is a thin fibrous connective tissue located between two mineralized tissues, alveolar bone and cementum, which maintains a constant width physiologically. The mechanisms by which PDL resists mineralization are not well understood. Twist is a basic helix loop helix protein that plays a central role in regulation of early osteogenesis. We investigated the localization of Twist in PDL and compared the expression of Twist and osteoblast-related genes in PDL cells with those in osteoblast-like cells in the presence or absence of recombinant human bone morphogenetic protein (BMP)-2. Histochemical analysis showed that Twist was expressed along alveolar bone surface in PDL. PDL cells Constitutively expressed Twist gene and the expression level was higher than that in osteoblast-like cells. In osteoblast-like cell Culture, BMP-2 enhanced osteoblast-related gene expression, while Twist expression was slightly decreased. In contrast, BMP-2 increased runt-related transcription factor (Runx)-2, but failed to enhance alkaline phosphatase (ALP) and osteocalcin (OCN) gene expression in PDL cells. Interestingly, unlike in osteoblast-like cells, Twist expression was upregulated by BMP-2 in PDL cells. We transiently knocked down Twist gene in PDL cells using a short interference RNA expression vector (siTwist) and found that ALP, osteopontin (OPN), bone sialoprotein (BSP) genes expression and basal level of ALP activity were slightly increased, whereas Runx2 and OCN genes were not affected. Collectively, these results suggest that twist may act as a negative regulator of osteoblastic differentiation in PDL cells.