低氧模拟化合物防治骨质疏松及其骨缺损

发布时间：2018-06-30 18:58

本文选题：骨质疏松 + 骨缺损　；参考：《上海交通大学》2015年博士论文

【摘要】：由雌激素缺乏导致的骨质疏松症是威胁绝经后妇女的身体健康主要因素之一。骨质疏松性脆性骨折引起的大块骨缺损的修复一直是骨科难点。随着对于雌激素缺乏性骨质疏松发病机理研究的深入,目前认为低氧诱导因子信号通路(Hypoxia Inducible Factor-α,HIF-α)的失调在该类型的骨质疏松的发病中起着重要的作用;同时调控HIF-α信号通路对于骨折愈合、骨缺损修复亦有显著的促进作用。二甲基乙二酰甘氨酸(Dimethyloxalylglycine/DMOG)、去铁胺(Desferrioxamine/DFO)是在常氧条件下激活HIF-α信号通路的一类化合物,被称为“低氧模拟化合物”。因此低氧模拟化合物可能对雌激素缺乏骨质疏松防治及骨质疏松骨缺损修复具有潜在作用。目的阐明低氧模拟化合物对雌激素缺乏性骨质疏松的防治作用及对于骨质疏松性骨缺损修复的促进作用。方法1.在体外研究低氧模拟化合物DMOG对小鼠间充质干细胞C3H10T1/2的成骨分化的影响,并阐明其中可能的机理。2.利用切除卵巢的方法建立骨质疏松模型,通过腹腔注射DMOG干预小鼠。通过Micro-CT、生物力学、组织形态学、Real-PCR、Westernblot、Elisa等方法评价DMOG干预后小鼠骨密度、骨结构、骨强度、骨代谢的变化,同时阐明HIF-α、Wnt/β-catenin信号通路变化。3.建立骨质疏松大鼠股骨远端骨缺损模型,将负载有DFO的poly(Lactic-co-glycolic acid)/PLGA支架材料植入大鼠体内。利用Micro-CT、骨组织形态学、免疫组化等方法评价DFO对骨质疏松性骨缺损修复的作用。结果1.DMOG能激活对小鼠间充质干细胞C3H10T1/2上的HIF-α信号通路,促进成血管因子VEGF分泌;同时DMOG能促进C3H10T1/2成骨分化过程中碱性磷酸酶表达、钙盐沉积,提高Runx-2、Osterix、β-catenin等成骨基因表达,激活Wnt/β-catenin信号通路。2.DMOG干预组小鼠的骨密度、骨量、骨强度、血管含量,骨骼中HIF-1α、VEGF、β-catenin的蛋白表达要高于卵巢切除组;同时骨形成速率增加,而骨吸收没有显著性变化。3.2W时植入含有DFO的PLGA大鼠骨缺损处血管量、骨量要明显多于对照组,4W时该组大鼠骨缺损愈合的骨量要明显多于对照组。结论1.DMOG能激活HIF-α通路,促进间充质干细胞成骨分化。2.DMOG能部分阻止卵巢切除小鼠骨质疏松形成,机理在于促进血管及促进骨形成。3.含有DFO的PLGA能有效促进骨质疏松大鼠骨缺损的愈合。
[Abstract]:Osteoporosis due to estrogen deficiency is one of the major threats to postmenopausal women's health. The repair of large bone defect caused by osteoporotic brittle fracture is always difficult in orthopedic department. With the further study of the pathogenesis of estrogen deficiency osteoporosis, it is believed that the disturbance of hypoxia InduFactor- 伪 HIF- 伪 plays an important role in the pathogenesis of this type of osteoporosis. Regulation of HIF- 伪 signaling pathway also promotes fracture healing and bone defect repair. Dimethyloxalyl glycine / DMOG, Desferrioxamine / DFO, is a kind of compound that activates HIF- 伪 signaling pathway under normoxic conditions, which is called "analogue compound of hypoxia". Hypoxia mimics may have potential effects on the prevention and treatment of estrogen deficiency and the repair of osteoporosis bone defect. Objective to elucidate the preventive and therapeutic effects of hypoxic mimic compounds on estrogen deficiency osteoporosis and promote the repair of osteoporosis bone defect. Method 1. The effects of hypoxia mimic compound DMOG on the osteogenic differentiation of mouse mesenchymal stem cells C3H10T1 / 2 were studied in vitro, and the possible mechanism was elucidated. Osteoporosis model was established by ovariectomized method. The changes of bone mineral density, bone structure, bone strength and bone metabolism were evaluated by Micro-CTT, biomechanics, histomorphology Real-time PCR and Western blot Elisa, and the changes of HIF- 伪 Wnt- / 尾 -catenin signaling pathway were elucidated at the same time. The bone defect model of distal femur was established in osteoporosis rats. The poly (Lactic-co-glycolic acid) / PLGA scaffold material loaded with DFO was implanted into rats. Micro-CTS, bone histomorphology and immunohistochemistry were used to evaluate the effect of DFO on the repair of osteoporotic bone defect. Results 1. DMOGs could activate the HIF- 伪 signaling pathway on C3H10T1 / 2 of mouse mesenchymal stem cells and promote the secretion of vascular factor VEGF, at the same time, DMOGs could promote the expression of alkaline phosphatase, calcium deposition, and increase the expression of Osterix, 尾 -catenin and other osteogenic genes during the osteogenic differentiation of C3H10T1 / 2. Activation of Wnt- 尾 -catenin signaling pathway. 2. Bone density, bone mass, bone strength, blood vessel content, protein expression of HIF-1 伪 -VEGFand 尾 -catenin in bone of mice in DMOG-treated group were higher than those in ovariectomized group, and the rate of bone formation was increased. However, there was no significant change in bone resorption at 3.2W when PLGA rats were implanted with DFO, the amount of blood vessels in the bone defect was significantly higher than that in the control group (4W), and the bone mass of the PLGA rats with DFO was significantly higher than that of the control group (P < 0.05). Conclusion 1. DMOGs can activate HIF- 伪 pathway and promote osteogenic differentiation of mesenchymal stem cells. 2. DMOG can partially prevent the formation of osteoporosis in ovariectomized mice. The mechanism is to promote blood vessels and bone formation. PLGA containing DFO can effectively promote bone defect healing in osteoporosis rats.
【学位授予单位】：上海交通大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：R580;R683

【相似文献】