The analysis of bone related diseases in cranio and oro-maxillofacial region by using A170 gene knockout mouse

本研究旨在利用A170基因敲除小鼠研究佩吉特骨病致病基因A170在颅颌面骨相关疾病中的作用。由于Nrf 2是氧化应激诱导蛋白的转录因子，而Nrf 2基因敲除小鼠缺乏A170的诱导，因此在回交过程中，我们对Nrf 2基因敲除小鼠的表型进行了分析。由于Peroxiredoxin I受Nrf 2的调节，我们测定了Peroxiredoxin I缺陷小鼠的活性氧清除能力，以评估A170基因敲除小鼠的氧化应激。骨形态计量学参数：类骨质表面、类骨质厚度、侵蚀表面、破骨细胞表面、骨小梁数量、矿物质沉积率和骨形成率在基因敲除小鼠和野生型小鼠之间存在显著差异。培养小鼠胚胎颅骨成骨细胞，测定碱性磷酸酶活性和ArizarinRed-S染色密度。基因敲除小鼠成骨细胞活性有降低的趋势。A170基因敲除小鼠的其他表型为食欲过盛、肥胖和胰岛素抵抗。通过葡萄糖负荷试验和胰岛素负荷试验证实胰岛素抵抗。用同位素标记的2-脱氧葡萄糖证明葡萄糖摄取减少。由此可见，A170基因敲除小鼠成骨细胞功能受损，胰岛素信号可能与这一现象有关。

The purpose of this study is to elucidate the role of A170 gene, which is causative gene of Paget's disease of bone, in the bone related diseases in cranio-oro-maxillofacial region by using A170 gene knockout mouse.At first, we repeated backcross of knockout mice because the value of bone morphometry was not constant. While backcross was undergoing, we analyzed the phenotype of Nrf2 knockout mouse, because Nrf2 was transcription factor of oxidative stress inducible proteins and Nrf2deficient mouse lacks A170 induction. Since Peroxiredoxin I was regulated by Nrf2, we measured the elimination capacity of reactive oxygen species in Peroxiredoxin I deficient mouse to prepare estimation of oxidative stress in A170 knockout mouse.After backcross was repeated, we performed bone morphometry. The parameters of bone morphometry : osteoid surface, osteoid thickness, eoroded surface, osteoclast surface, trabecular number, mineral apposition rate, and bone formation rate were significantly different between knockout mouse and wild type mouse. The osteoblast from calvaria of mouse embryo was cultured, and alkaline phosphatase activity and Arizarin Red-S staining density were measured. There was tendency that the osteoblastic activity was lower in the knockout mice. The other phenotypes of A170 gene knockout mouse were hyperphagia, obesity, and insulin resistance. Insulin resistance was proved by-glucose and insulin loaded test. Glucose uptake was proved to be reduced by using isotope labeled 2-deoxyglucose. From those results osteoblastic function was damaged in A170 knockout mouse and insulin signal may be associated with this phenomenon.