应力环境下破骨细胞碳酐酸酶Ⅱ的基因表达

Expression of carbonic anhydrase Ⅱ in cultured rat osteoclasts after stress stimulation

目的研究流体切应力条件下大鼠破骨细胞碳酐酸酶Ⅱ(CaⅡ)mRNA的表达变化,探讨应力环境下大鼠破骨细胞的功能活动情况。方法采用1,25-(OH)2D3/地塞米松诱导SD大鼠骨髓细胞,抗酒石酸酸性磷酸酶染色和扫描电镜鉴定破骨细胞,0.25%胰蛋白酶/0.02%乙二胺四乙酸(EDTA)进行细胞纯化。对破骨细胞施加不同力值和作用时间的流体切应力,采用实时荧光定量巢式逆转录聚合酶链反应(RT-PCR)检测CaⅡmRNA的表达。结果随着力值的增加和作用时间的延长,破骨细胞CaⅡmRNA的表达量分别呈下降趋势(P<0.05)。结论在一定范围的流体切应力作用下,破骨细胞CaⅡmRNA的表达受到抑制,表达水平与力值大小和加载时间分别存在负相关关系。

Objective To test expression of carbonic anhydrase Ⅱ （Ca Ⅱ ） mRNA in osteoclasts which were applied with fluid shear stress. Methods The bone marrow cells of Sprague-Dawley rats were cultured with the presence of 1,25-（OH）2D3 and dexamethasone. The osteoclast-like cells were identified by tartrate-resistant acid pbosphatase（TRAP） staining and scanning electron microscope （SEM） observation, then purified with trypsin/ethylenediamine tetraacetic acid （EDTA）. Different values and lasting time of steady fluid shear stress were exerted on the osteoclasts with parallel plate flow system. The CaⅡexpression of osteoclasts were detected by real time reverse transcription-polymerase chain reaction CRT-PCR） and nested polymerase chain reaction（PC1D. Results The levels of CaⅡ mRNA were down-regu- lated correspondingly with the increase of stress and time（P〈0.05）. Conclusion It＇s indicated that steady fluid shear stress within a certain range may down-regulate the expression of CaⅡ in osteoclasts.