中文摘要：

目的：PKD2（polycystin2,多囊肾病蛋白2）能够在细胞膜上形成无选择性的阳离子通道,在肾上皮细胞中PKD2与初级纤毛共定位,通过改变胞内的钙信号过程参与细胞对力学刺激的响应。本实验通过二维回转培养来模拟失重效应,旨在探讨二维回转培养对MLO-Y4骨样细胞PKD2表达定位,及胞内钙信号的影响。初步了解PKD2在小鼠骨样细胞MLO-Y4响应力学刺激过程中起的作用。方法：采用二维回转培养骨样细胞MLO-Y4,用RT-PCR和western blotting检测PKD2的表达,用荧光共聚焦显微镜检测细胞中PKD2与初级纤毛的定位及细胞内钙离子含量。结果：与对照组相比,在二维回转培养后,骨样细胞MLO-Y4的PKD2表达在mRNA和蛋白水平都有明显的下降,PKD2、PKD1（polycystin1,多囊肾病蛋白1）和乙酰化的α-tubulin共定位,同时二维回转培养降低了细胞内钙离子含量。结论：在二维回转培养下,PKD2可能通过调节自身表达来改变细胞膜上PKD通道的数目和开放情况来影响细胞内钙离子含量,参与骨细胞对细胞外应力的感受过程,其详细机制还有待进一步实验研究。这将对探讨骨细胞响应力学刺激的具体机制提供重要的理论依据。

英文摘要：

Objective： PKD2（polycystin2） could form nonspecific cation channel on the cytomembrane, which is responsible for Ca^2＋penetration when kidney epithelial cell transforms mechanical stimulation into intracellular chemical information. In this study, 2D-clinorotation was used to simulate weightlessness condition. The aim of this study was to investigate the effects of 2D-clinorotation culture on expression and location of PKD2 protein and the intracellular Ca^2＋concentration of mouse osteocyte-like MLO-Y4 cell. Also we want to understand the role of PKD2 in the process of MLO-Y4 responsding to mechanical stimulation. Methods： Mouse osteocyte-like MLO-Y4 cell were cultured under the condition of 2D-Clinorotation.The expression and location of PKD2 was detected by RT-PCR, western-blotting and fluorescent staining, the intracellular Ca^2＋concentration was detected by Ca^2＋staining technique. Results： Under the condition of 2D-Clinorotation culture, the exspression of PKD2 and the intracellular Ca^2＋concentration were distinctly reduced. At the same time, we found that PKD2 co-localized with PKD1（polycystin1） and the specific ciliary axoneme marker-acetylated α-tubulin. Conclusion： the results suggest under 2D-clinorotation culture, mouse osteocyte-like cell could respond to the mechanical stimulation by regulating the expression of PKD2 and the intracellular Ca^2＋concentration. It is helpful to investigate the cellular mechanism of bone cells in responding to mechanical stimulation.