破骨细胞钠氢转运蛋白集中于线粒体中表达

Na+-H+ antiporter mainly expressed in the mitochondria of mammalian osteoclast

摘要:

目的：把RAW264.7和人外周血CD14+ 诱导成破骨样细胞，检测破骨细胞在成熟过程中钠氢转运蛋白2（Na+-H+ An－tiporter 2，NHA2）的转录表达情况，并定位其表达位置。方法：细胞因子RANKL、M-CSF在体外诱导RAW264.7和人外周血CD14+细胞发育成破骨样细胞；RT-PCR检测NHA2在诱导过程中转录水平上所发生的变化；Western blot检测诱导前后此蛋白表达情况；细胞原位荧光染色对其表达进行细胞精确定位。结果：RAW264.7和人外周血CD14+ 细胞被RANKL、M-CSF诱导成破骨样细胞；RT-PCR结果显示NHA2随着破骨细胞的分化成熟转录水平不断加强；Western blot结果显示此蛋白只表达于成熟的破骨细胞中；细胞原位荧光染色结果显示这个蛋白主要表达于成熟破骨细胞的线粒体中。结论：NHA2作为盐离子载体主要表达于成熟破骨细胞的线粒体中，通过控制线粒体盐离子的代谢平衡来影响破骨细胞的发育分化

Abstract:

Objective：To induce the RAW264.7 and human blood CD14+ cells to differentiate into osteoclasts，to detect the transcrip－tion and expression of the osteoclast during its differentiation and maturation，and define the expressing position of Na+-H+ antiporter 2. Methods：The RAW264.7 and human blood CD14+ cells were induced to differentiate into osteoclasts by RANKL and M-CSF in vitro；the transcription of NHA2 was detected by RT-PCR during induction；the antiporter expression was tested by Western blot be－fore and after induction，and the exact position of its expression was defined by immunocytochemistry. Results：The RAW264.7 and human blood CD14+ cells were differentiated into osteoclasts by RANKL and M-CSF；the RT-PCR result indicated the transcription level was increased during osteoclast differentiation and maturation；the Western blot test revealed the antiporter was only expressed in the maturated osteoclast；and the immunocytochemistry experiment told us that the antiporter was mainly expressed in the mito－chondria of osteoclast. Conclusion：Na+-H+ Antiporter 2 was mainly expressed in the mitochondria of maturated osteoclast as a salt antiporter，which will affect the development and differentiation of osteoclast through controlling the metabolized balance of mitochon－dria.