目的 构建靶向CXCR7基因的CRISPR/Cas9基因编辑系统,并应用于HEK 293T细胞系。方法 设计两对靶向CXCR7基因的sgRNAs,分别插入PX458载体中,并转化DH5α大肠埃希菌。经菌液PCR和测序验证,挑选序列正确的sgRNA-CXCR7-PX458质粒,转染HEK 293T细胞,用流式分选转染阳性细胞,提取其DNA,PCR扩增后测序验证。结果 经测序验证,成功构建了靶向CXCR7基因的CRISPR/Cas9系统,转染HEK 293T细胞后,测序鉴定发现成功编辑CXCR7基因。结论 成功构建了靶向CXCR7的sgRNA-CXCR7-PX458质粒,可在HEK 293T上成功编辑CXCR7基因,为进一步的功能研究奠定基础。

Objective To construct the CRISPR/Cas9 gene editing system targeting C-X-C chemokine receptor 7 (CXCR7) gene and to edit CXCR7 gene in 293T cell line. Methods Two pairs of small guide RNAs (sgRNAs) targeting CXCR7 gene were designed and inserted into PX458 vector, which were transformed into host bacterium Escherichia coliDH5α. The correct sgRNA-CXCR7-PX458 plasmids were selected by PCR and further Sanger sequencing verification. HEK 293T cell line was transfected by DNA of sgRNA-CXCR7-PX458 plasmid. After 72 hours,GFP-positive cells were sorted by flow cytometry. We did DNA extraction of the GFP-positive cells and amplified the CXCR7 gene corresponding fragment by PCR and investigated the CXCR7 gene editing results by Sanger sequencing. Results The CRISPR/Cas9 system targeting CXCR7 gene was successfully constructed. After 293T cells were transfected, the CXCR7 gene was edited in HEK 293T cells successfully. Conclusion The sgRNA-CXCR7-PX458 plasmid targeting CXCR7 gene was successfully constructed. The CRISPR/Cas9 gene editing system targeting CXCR7 gene were used on the HEK 293T cell line, which lays a foundation for further study of BCOR function.

目的 采用生物信息学方法预测低氧预处理人胎盘绒毛膜间充质干细胞环状RNAs相对应的miRNA及其靶基因,并分析靶基因所参与的生物学过程和信号通路。方法 用Arraystar公司的商业软件为环状RNAs预测其相对应的miRNAs,分别用targetScan7.1和mirdbV5数据库预测miRNAs的靶基因,并取两个预测结果的合集,应用在线网站http://www.geneontology.org和http://www.genome.ad.jp/kegg对靶基因进行功能富集分析和信号通路富集分析。结果 功能富集分析表明,circRNAs的靶基因主要涉及到细胞发育、细胞分化和细胞发育调控。东京基因和基因组百科全书信号通路富集分析表明肿瘤中转录失控和有丝分裂原激活蛋白激酶(MAPK)信号通路最有意义,而且分析发现MAPK信号通路为核心通路。本研究表明,低氧预处理使得间充质干细胞中部分circRNAs的表达量发生差异性变化。结论 低氧预处理人胎盘绒毛膜间充质干细胞环状RNAs同低氧预处理间充质干细胞的生物学特性变化密切有关,为了解低氧预处理影响间充质干细胞特性发生变化的分子机制提供新思路。

Objective To predict the miRNA and its target genes of circular RNAs in hypoxia- preconditioned human palcenta chorionic mesenchymal stem cells using bioinformatics, and analyze the biological process and signaling pathway. Methods Arraystar's commercial software was used to predict the corresponding miRNAs of circular RNAs. The target genes of miRNAs were predicted by targetScan7.1 and mirdbV5 databases respectively, and an intersection of two prediction results was obtained. The online databases http://www. geneontology.org and http://www.genome.ad.jp/kegg performed functional enrichment analysis and signal pathway enrichment analysis of target genes. Results Functional enrichment analysis indicated that the target genes of circRNAs mainly involved cell development, cell differentiation and cell development regulation. The signal enrichment analysis of the Tokyo Gene and Genome Encyclopedia indicates that transcriptional misregulation in cancer and mitogen-activated protein kinase (MAPK) signaling pathway are most meaningful, and the MAPK signaling pathway is found to be the core pathway. This study showed that hypoxic preconditioning caused significant changes in the expression of mesenchymal stem cell circRNAs. Conclusion The changes of circular RNAs in hypoxia-preconditioned human placental chorionic mesenchymal stem cell is closely related to the biological characteristics of hypoxia-preconditioned mesenchymal stem cells. This study provides a new idea for understanding the molecular mechanism of hypoxic preconditioning affecting the changes of biological characteristics in mesenchymal stem cells.