微小RNA（miR）是一种调节成骨分化的重要生物分子。前期研究发现miR-33和miR-3070a在力学载荷促进成骨分化中差异表达，并证实miR-33的靶基因为 Naa15（一种转乙酰酶亚基)，miR-3070a的靶基因为ATP13a3 (一种ATP酶)，这两个靶基因也差异表达。本课题采用miR过表达及抑制技术，利用细胞分子生物学手段，揭示载荷作用下miR-33和miR-3070a分别通过Naa15和ATP13a3调节细胞成骨分化的过程，探讨在成骨细胞“力学载荷-生物效应”的信号转导过程中，这两种miRs的作用机理; 同时采用基因过表达和RNA干扰技术，利用基因芯片和生物信息学手段，探讨载荷作用下Naa15或ATP13a3可能影响的成骨分化基因和信号途径。本课题将发现新的调节成骨分化的力学响应miR和基因，给力学载荷调节成骨分化的研究，带来新内容，并为防治骨相关疾病，提供新靶标。

MicroRNA (miR) is an important biomolecule that regulate osteoblastic differentiation. In our previous study, miR-33 and miR-3070a were differentially expressed during the osteogenesis promoted by mechanical loading. Our experiment had proved that the target genes of miR-33 and miR-3070a were N-alpha-acetyltransferase (Naa15, a subunit of a kind of transacetylase) and ATPase type 13a3 (ATP13a3, a kind of ATP enzyme), respectively，and the two target genes are both differentially expressed too. In this study, by over-expression and inhibition of both of the two miRs, using cellular and molecular biological method, the mechanism of the miRs involved in the process of mechanical loading promoted osteogenesis via target genes was revealed， and the signals transduction of “mechanical loading-biological response” in osteoblasts was studied. At the same time, by over-expression and small RNA interference of the two target genes, using gene chip and bioinformatic methods, the osteogenesis-related gene and signal pathways regulated by Naa15 or ATP13a3 were explored. This study will find new mechanoresponsive miRs and genes which regulated osteoblastic differentiation, bring a new vision of osteogenesis regulated by mechanical loading , and provide new molecular targets for prevention and cure of bone-related disease.