颞下颌关节盘移位及应力对生长期兔髁突软骨内成骨的影响

发布时间：2018-06-25 18:25

本文选题：生长期 + 颞下颌关节　；参考：《上海交通大学》2014年博士论文

【摘要】：目的通过建立生长期兔颞下颌关节盘前移位模型、离体髁突压力加载培养、体外髁突软骨细胞应力加载培养,从体内体外两个方面，组织和细胞两个层面，研究生长期关节盘移位和不同应力对下颌骨髁突软骨内成骨的影响及其机制，并探索促进髁突软骨（细胞）软骨内成骨的适宜压力。方法 1.颞下颌关节盘前移位对生长期兔髁突软骨内成骨的影响建立生长期兔颞下颌关节盘前移位模型，，在1周、2周、4周、8周时处死取材，检测软骨内成骨标志物SOX9、血管内皮生长因子（Vascular endothelialgrow th factor，VEGF）、II型和X型胶原的表达变化。 2.压力对离体生长期兔髁突软骨内成骨的影响将生长期兔髁突组织在不同压力（0kPa，15kPa，30kPa，45kPa，60kPa，75kPa）加载下离体培养，检测软骨内成骨标志物SOX9、VEGF、II型和X型胶原的表达变化以及髁突软骨细胞凋亡的变化。 3.应力加载对生长期兔髁突软骨细胞成软骨和成骨能力的影响体外培养生长期兔髁突软骨细胞，经过不同大小应力（-50kPa，-30kPa，-10kPa，0kPa，50kPa，100kPa，150kPa，200kPa）加载后，检测软骨细胞增殖和凋亡、成软骨标志物II型胶原、蛋白聚糖（Aggrecan，AGG）和成骨标志物X型胶原、碱性磷酸酶（Alkaline phosphatase，ALP）表达、细胞表面微观形态和超微结构变化。结果 1.在生长期兔颞下颌关节盘前移位后1周，软骨变薄、退变萎缩，髁突软骨内成骨标志物表达均抑制；在盘移位2周后，软骨细胞代偿性增生，至4周时增生达高峰，到8周时增生失代偿，在此阶段内软骨肥大层变薄或消失，各软骨内成骨标志物不同程度抑制。 2.离体髁突当承受适宜的压力负荷（30kPa）时，髁突软骨内成骨标志物表达增加，软骨增殖层、成熟层凋亡细胞增加，成骨、改建过程活跃；当承受的压力负荷在0kPa、15kPa时，髁突软骨内成骨标志物表达减少，髁突软骨内成骨能力下降；当承受的压力负荷在45kPa、60kPa和75kPa时，髁突软骨受到破坏，软骨内成骨标志物不同程度减少，软骨细胞凋亡增加，髁突软骨内成骨能力下降。 3.正压：体外培养的髁突软骨细胞在150kPa时增殖增加，凋亡无明显变化，成软骨和成骨标志物表达增加；0kPa、50kPa和100kPa时，增殖增加、凋亡减少，成软骨和成骨标志物表达抑制；200kPa时，增殖减少、凋亡坏死增加，成软骨和成骨标志物表达抑制。负压：-10kPa和-30kPa时，增殖增加，凋亡无明显变化，成软骨和成骨表达无明显增加；-50kPa时，增殖和凋亡坏死增加，II型和X型胶原表达也增加。结论在生长期，颞下颌关节盘移位影响了髁突软骨内成骨过程，从而导致了髁突发育障碍。适宜的应力负荷使髁突软骨保持活跃的软骨内成骨能力；过小的应力负荷不足以刺激髁突发挥软骨内成骨能力；过大的应力负荷抑制髁突软骨内成骨。
[Abstract]:Objective to establish the anterior disc displacement model of temporomandibular joint (TMJ) in growing rabbits, and to culture condyle chondrocytes under in vitro condyle pressure loading and in vitro condylar chondrocytes, in vivo and in vitro, from two aspects: tissue and cell levels. The effects of long-term disc displacement and different stresses on the osteogenesis of mandibular condylar cartilage and its mechanism were studied, and the suitable pressure to promote the osteogenesis of condylar cartilage (cells) was explored. Method 1. Effect of anterior disc displacement of temporomandibular joint on intracondral osteogenesis of condylar process in growing rabbits the model of anterior disc displacement of temporomandibular joint was established and killed at 1 week, 2 weeks, 4 weeks and 8 weeks, respectively. The expression of osteoblastic markers SOX9, vascular endothelialgrow growth factor (Vascular endothelialgrow factor-VEGF) type II and type X collagen were detected. 2. Effect of pressure on osteogenesis in condylar cartilage of rabbits in vitro the condylar tissue of growing rabbits was cultured in vitro under different pressures (0 KPA, 15 KPA, 30 KPA, 45 KPA, 60 KPA, 75 KPA). The expression of type II and type X collagen and apoptosis of condylar chondrocytes were detected. 3. Effects of stress loading on cartilage formation and osteogenesis of rabbit condylar chondrocytes in vitro, the proliferation and apoptosis of chondrocytes were detected after different stress (-50kPa-30kPa-30kPa-10kPa-10kPa-50kPa-100kPa-150kPa-200kPa) were applied to the cultured rabbit condylar chondrocytes in vitro. The expression of collagen type II, proteoglycan (agg) and collagen X (osteogenic marker), Alkaline phosphatase (ALP), and the changes of cell surface morphology and ultrastructure were observed. Result 1. At 1 week after anterior disc displacement of temporomandibular joint in growing rabbits, cartilage thinned, degeneration and atrophy, the expression of osteogenic markers in condylar cartilage were inhibited, and the proliferation of chondrocytes reached the peak at 4 weeks after disc displacement. At 8 weeks after decompensation, the hypertrophic layer of cartilage was thinned or disappeared, and the osteogenic markers of each cartilage were inhibited to some extent. 2. When the condyle in vitro was subjected to suitable pressure (30 KPA), the expression of osteogenic markers in condylar cartilage increased, the apoptotic cells in the proliferative layer and mature layer of cartilage increased, osteogenesis and remodeling were active, and when the pressure load was at 0 KPA 15 KPA, the expression of osteogenic markers in condyle cartilage increased. The expression of osteogenic markers in condylar cartilage decreased, and the osteogenic ability of condylar cartilage decreased. When the pressure load was at 45kPa60kPa and 75kPa, the cartilage of condylar process was destroyed, the markers of osteogenesis in cartilage decreased, and the apoptosis of chondrocytes increased. The osteogenesis ability of condylar cartilage was decreased. 3. Positive pressure: the proliferation and apoptosis of condylar chondrocytes cultured in vitro increased at 150 KPA, while the expression of cartilage and osteogenic markers increased at 50 KPA and 100 KPA. Proliferation decreased, apoptosis and necrosis increased, cartilage formation and osteogenic markers expression was inhibited. At negative pressure of -10 KPA and -30 KPA, proliferation increased, but apoptosis did not change, while the expression of cartilage and osteogenesis did not increase significantly at -50 KPA, the expression of type II and type X collagen also increased. Conclusion in the growth stage, the temporomandibular joint disc displacement affects the osteogenesis process of condylar cartilage, which leads to condylar dysplasia. The proper stress load keeps the condylar cartilage active in endochondral osteogenesis; too small stress load is not enough to stimulate the condyle to exert the endochondral osteogenesis; too much stress load inhibits the endochondral osteogenesis of condylar process.
【学位授予单位】：上海交通大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：R782.6

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