Department of Biochemistry and Molecular Biology, Nihon University School of Dentistry at Matsudo, 2-870-1, Sakaecho-Nishi, Matsudo, Chiba 271-8587, Japan.
Bone. 2011 Apr 1;48(4):864-77. doi: 10.1016/j.bone.2010.11.019. Epub 2010 Dec 4.
Beta-tricalcium phosphate (β-TCP) is widely used in clinical orthopedic surgery due to its high biodegradability, osteoconductivity, easy manipulation and lack of histotoxicity. However, little is known about the molecular mechanisms responsible for the beneficial effects of β-TCP in bone formation. In this study, β-TCP was implanted in dog mandibles, after which the gene expression profiles and signaling pathways were monitored using microarray and Ingenuity Pathways Analysis (IPA). Following the extraction of premolars and subsequent bone healing, β-TCP was implanted into the artificial osseous defect. Histological evaluation (H-E staining) was carried out 4, 7 and 14 days after implantation. In addition, total RNA was isolated from bone tissues and gene expression profiles were examined using microarray analysis coupled with Ingenuity Pathways Analysis (IPA). Finally, real-time PCR was used to confirm mRNA levels. It was found that β-TCP implantation led to a two-fold change in 3409 genes on day 4, 3956 genes on day 7, and 6899 genes on day 14. Among them, the expression of collagen type I α1 (COL1A1), alkaline phosphatase (ALP) and transforming growth factor (TGF)-β2 was increased on day 4, the expression of receptor activator of NF-kappaB ligand (RANKL) and interferon-γ (IFN-γ) was decreased on day 7, and the expression of osteoprotegerin (OPG) was decreased on day 14, affecting the bone morphogenetic protein (BMP), Wnt/β-catenin and nuclear factor-kappaB (NF-κB) signaling pathways in osteoblasts and osteoclasts. Simultaneously, vascular cell adhension molecule (VCAM)-1 expression was increased on day 4 and stromal cell-derived factor (SDF)-1 expression was increased on days 4 and 14. Taken together, these findings shed light on some of the cellular events associated with bone formation, bioresorption, regeneration and healing of β-TCP following its implantation. The results suggest that β-TCP enhances bone healing processes and stimulates the coordinated actions of osteoblasts and osteoclasts, leading to bone regeneration.
β-磷酸三钙（β-TCP）由于其高生物降解性、骨传导性、易于操作和缺乏组织毒性而广泛应用于临床骨科手术。然而，对于β-TCP 在骨形成中有益作用的分子机制知之甚少。在这项研究中，将β-TCP 植入狗下颌骨，然后使用微阵列和 IPA（Ingenuity Pathways Analysis）监测基因表达谱和信号通路。在提取前磨牙并随后进行骨愈合后，将β-TCP 植入人工骨缺损中。植入后 4、7 和 14 天进行组织学评估（H-E 染色）。此外，从骨组织中提取总 RNA，并使用微阵列分析结合 IPA（Ingenuity Pathways Analysis）检查基因表达谱。最后，使用实时 PCR 确认 mRNA 水平。结果发现，β-TCP 植入后第 4 天有 3409 个基因的表达发生了两倍的变化，第 7 天有 3956 个基因，第 14 天有 6899 个基因。其中，Ⅰ型胶原α1（COL1A1）、碱性磷酸酶（ALP）和转化生长因子-β2（TGF-β2）的表达在第 4 天增加，核因子κB 受体激活剂配体（RANKL）和干扰素-γ（IFN-γ）的表达在第 7 天减少，骨保护素（OPG）的表达在第 14 天减少，影响成骨细胞和破骨细胞中的骨形态发生蛋白（BMP）、Wnt/β-catenin 和核因子-κB（NF-κB）信号通路。同时，第 4 天血管细胞黏附分子（VCAM）-1 的表达增加，第 4 天和第 14 天基质细胞衍生因子（SDF）-1 的表达增加。综上所述，这些发现揭示了一些与骨形成、生物吸收、β-TCP 植入后的再生和愈合相关的细胞事件。结果表明，β-TCP 增强了骨愈合过程，并刺激了成骨细胞和破骨细胞的协调作用，从而促进了骨再生。
