目的  探讨抑制趋化因子受体7（CXCR7）的表达对低氧状态下人尿源性干细胞（USCs）增殖、迁移、分化和线粒体功能的影响。 方法  低氧组3%O2处理48h，采用CXCR7 siRNA(siCXCR7)抑制CXCR7的表达，Real-time PCR和Western blotting检测CXCR7的表达；集落形成实验和细胞生长曲线检测细胞增殖能力；划痕实验及Transwell实验检测细胞迁移能力；碱性磷酸酶、茜素红、油红O、阿利新蓝染色检测细胞多向分化能力；JC-1荧光探针、三磷酸腺苷（ATP）及活性氧（ROS）水平检测评估线粒体功能。 结果  低氧组USCs中CXCR7的表达显著上调，USCs的增殖、迁移和集落形成能力增强，抑制CXCR7表达可抑制低氧对USCs的增殖、迁移和集落形成的作用，对细胞分化没有影响。低氧处理提高了线粒体膜电位和ATP水平，降低了活性氧的产生，而抑制CXCR7可降低线粒体膜电位和ATP的产生。 结论  低氧可能通过CXCR7信号通路增强USCs的线粒体功能，从而促进细胞的增殖和迁移能力。 

Objective  To investigate the effects of inhibition of chemokine C-X-C motif receptor 7(CXCR7) expression on the proliferation, migration, differentiation and mitochondrial function of human urine-derived stem cells(USCs) under hypoxia.  Methods  CXCR7 expression was inhibited by siCXCR7 and detected by Real-time PCR and Western blotting in hypoxia group treated with 3%O2 for 48 hours. Cell proliferation was detected by clonal formation assay and cell growth curve. Cell migration ability was detected by scratch assay and Transwell assay. Alkaline phosphatase, alizarin red, oil red O and alcian blue staining were used to detect the multidirectional differentiation ability of cells. Mitochondrial function was evaluated by JC-1 fluorescent probe, adenosine triphosphate(ATP) and reactive oxygen species(ROS). Results  Compared with the normal oxygen group, the expression of CXCR7 in USCs in hypoxia group was significantly up-regulated, and hypoxia promoted the proliferation, migration and clonogenesis of USCs. SiCXCR7 inhibited the expression of CXCR7 and inhibited the effects of hypoxia on the proliferation, migration and clonogenesis of USCs, but had no effect on cell differentiation. Hypoxia treatment increased mitochondrial membrane potential and ATP levels, and decreased the production of reactive oxygen species, while CXCR7 inhibition decreased mitochondrial membrane potential and ATP production. Conclusion  Hypoxia may enhance mitochondrial function of USCs through the CXCR7 signaling pathway, thereby promoting cell proliferation and migration.