【摘要】 目的:在成功构建髁突软骨细胞体外培养-力学刺激模型的基础上,探讨周期性张应力对髁突软骨细胞主要细胞外基质(Ⅱ型胶原)合成的影响。方法:本研究采用FX-5000T应力加载系统对体外培养的第3代大鼠髁突软骨细胞分别施加1 h、6 h、12 h和24 h的周期性张应力,应力刺激强度为10℅1 HZ。加力完成后即刻收集加力细胞,提取细胞总RNA反转录成cDNA,应用RT-PCR技术检测髁突软骨细胞主要细胞外基质Ⅱ型胶原(type-Ⅱcollagen,Col-Ⅱ)mRNA的表达变化情况。结果:与对照组(0 h组)相比,加力1 h时Col-Ⅱ的表达增加,但无统计学意义;加力6 h时Col-Ⅱ表达显著增加(P<0.05);加力12 h时Col-Ⅱ表达开始下降;当加力至24 h时表达量显著降低(P<0.05)。结论:周期性张应力可以影响髁突软骨细胞主要细胞外基质的合成,在一定范围内随加力时间的延长基质合成逐渐增强;进一步延长加力时间,基质的合成受到明显抑制。更多还原

【Abstract】 Objective: To study the effect of cyclic tensile stress on condyle chondrocyte main extracellular matrix based on successful construction of in vitro mechanical stimulation models.Methods: The cyclic tensile stress was exposed to the third passage condyle chondrocyte for 1,6,12 and 24 hours respectively by using a Flexcell Strain Unit-5000T(10℅surface elongation,6 cycles/min).After mechanical loading,total RNA was extracted from the cells harvested from Six-well BioFlex flexible cell Petri Dish,and RT-PCR was performed to quantify mRNA levels for type Ⅱ collagen.Results: Compared with the control group(0h group),type Ⅱ collagen mRNA expression was increased after 1 h loading,but there were no significant differences between loading and control group;after 6h cyclic tensile stress,the expression of Col-II increased significantly(P<0.05);after 12 and 24 h of loading,the expression for this cartilage-specific matrix protein reduced remarkably(P<0.05).Conclusion: The result illustrated that a cyclical tensile stress stimuli can affect the main condylar cartilage extracellular matrix synthesis,Col-Ⅱ can be promoted during early loading,with extended matrix synthesis increased continue,afterwards,further extend the matrix synthesis will be inhibited.更多还原